Source file src/net/http/serve_test.go

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // End-to-end serving tests
     6  
     7  package http_test
     8  
     9  import (
    10  	"bufio"
    11  	"bytes"
    12  	"compress/gzip"
    13  	"compress/zlib"
    14  	"context"
    15  	"crypto/tls"
    16  	"encoding/json"
    17  	"errors"
    18  	"fmt"
    19  	"internal/testenv"
    20  	"io"
    21  	"log"
    22  	"math/rand"
    23  	"mime/multipart"
    24  	"net"
    25  	. "net/http"
    26  	"net/http/httptest"
    27  	"net/http/httptrace"
    28  	"net/http/httputil"
    29  	"net/http/internal"
    30  	"net/http/internal/testcert"
    31  	"net/url"
    32  	"os"
    33  	"os/exec"
    34  	"path/filepath"
    35  	"reflect"
    36  	"regexp"
    37  	"runtime"
    38  	"strconv"
    39  	"strings"
    40  	"sync"
    41  	"sync/atomic"
    42  	"syscall"
    43  	"testing"
    44  	"time"
    45  )
    46  
    47  type dummyAddr string
    48  type oneConnListener struct {
    49  	conn net.Conn
    50  }
    51  
    52  func (l *oneConnListener) Accept() (c net.Conn, err error) {
    53  	c = l.conn
    54  	if c == nil {
    55  		err = io.EOF
    56  		return
    57  	}
    58  	err = nil
    59  	l.conn = nil
    60  	return
    61  }
    62  
    63  func (l *oneConnListener) Close() error {
    64  	return nil
    65  }
    66  
    67  func (l *oneConnListener) Addr() net.Addr {
    68  	return dummyAddr("test-address")
    69  }
    70  
    71  func (a dummyAddr) Network() string {
    72  	return string(a)
    73  }
    74  
    75  func (a dummyAddr) String() string {
    76  	return string(a)
    77  }
    78  
    79  type noopConn struct{}
    80  
    81  func (noopConn) LocalAddr() net.Addr                { return dummyAddr("local-addr") }
    82  func (noopConn) RemoteAddr() net.Addr               { return dummyAddr("remote-addr") }
    83  func (noopConn) SetDeadline(t time.Time) error      { return nil }
    84  func (noopConn) SetReadDeadline(t time.Time) error  { return nil }
    85  func (noopConn) SetWriteDeadline(t time.Time) error { return nil }
    86  
    87  type rwTestConn struct {
    88  	io.Reader
    89  	io.Writer
    90  	noopConn
    91  
    92  	closeFunc func() error // called if non-nil
    93  	closec    chan bool    // else, if non-nil, send value to it on close
    94  }
    95  
    96  func (c *rwTestConn) Close() error {
    97  	if c.closeFunc != nil {
    98  		return c.closeFunc()
    99  	}
   100  	select {
   101  	case c.closec <- true:
   102  	default:
   103  	}
   104  	return nil
   105  }
   106  
   107  type testConn struct {
   108  	readMu   sync.Mutex // for TestHandlerBodyClose
   109  	readBuf  bytes.Buffer
   110  	writeBuf bytes.Buffer
   111  	closec   chan bool // if non-nil, send value to it on close
   112  	noopConn
   113  }
   114  
   115  func (c *testConn) Read(b []byte) (int, error) {
   116  	c.readMu.Lock()
   117  	defer c.readMu.Unlock()
   118  	return c.readBuf.Read(b)
   119  }
   120  
   121  func (c *testConn) Write(b []byte) (int, error) {
   122  	return c.writeBuf.Write(b)
   123  }
   124  
   125  func (c *testConn) Close() error {
   126  	select {
   127  	case c.closec <- true:
   128  	default:
   129  	}
   130  	return nil
   131  }
   132  
   133  // reqBytes treats req as a request (with \n delimiters) and returns it with \r\n delimiters,
   134  // ending in \r\n\r\n
   135  func reqBytes(req string) []byte {
   136  	return []byte(strings.ReplaceAll(strings.TrimSpace(req), "\n", "\r\n") + "\r\n\r\n")
   137  }
   138  
   139  type handlerTest struct {
   140  	logbuf  bytes.Buffer
   141  	handler Handler
   142  }
   143  
   144  func newHandlerTest(h Handler) handlerTest {
   145  	return handlerTest{handler: h}
   146  }
   147  
   148  func (ht *handlerTest) rawResponse(req string) string {
   149  	reqb := reqBytes(req)
   150  	var output strings.Builder
   151  	conn := &rwTestConn{
   152  		Reader: bytes.NewReader(reqb),
   153  		Writer: &output,
   154  		closec: make(chan bool, 1),
   155  	}
   156  	ln := &oneConnListener{conn: conn}
   157  	srv := &Server{
   158  		ErrorLog: log.New(&ht.logbuf, "", 0),
   159  		Handler:  ht.handler,
   160  	}
   161  	go srv.Serve(ln)
   162  	<-conn.closec
   163  	return output.String()
   164  }
   165  
   166  func TestConsumingBodyOnNextConn(t *testing.T) {
   167  	t.Parallel()
   168  	defer afterTest(t)
   169  	conn := new(testConn)
   170  	for i := 0; i < 2; i++ {
   171  		conn.readBuf.Write([]byte(
   172  			"POST / HTTP/1.1\r\n" +
   173  				"Host: test\r\n" +
   174  				"Content-Length: 11\r\n" +
   175  				"\r\n" +
   176  				"foo=1&bar=1"))
   177  	}
   178  
   179  	reqNum := 0
   180  	ch := make(chan *Request)
   181  	servech := make(chan error)
   182  	listener := &oneConnListener{conn}
   183  	handler := func(res ResponseWriter, req *Request) {
   184  		reqNum++
   185  		ch <- req
   186  	}
   187  
   188  	go func() {
   189  		servech <- Serve(listener, HandlerFunc(handler))
   190  	}()
   191  
   192  	var req *Request
   193  	req = <-ch
   194  	if req == nil {
   195  		t.Fatal("Got nil first request.")
   196  	}
   197  	if req.Method != "POST" {
   198  		t.Errorf("For request #1's method, got %q; expected %q",
   199  			req.Method, "POST")
   200  	}
   201  
   202  	req = <-ch
   203  	if req == nil {
   204  		t.Fatal("Got nil first request.")
   205  	}
   206  	if req.Method != "POST" {
   207  		t.Errorf("For request #2's method, got %q; expected %q",
   208  			req.Method, "POST")
   209  	}
   210  
   211  	if serveerr := <-servech; serveerr != io.EOF {
   212  		t.Errorf("Serve returned %q; expected EOF", serveerr)
   213  	}
   214  }
   215  
   216  type stringHandler string
   217  
   218  func (s stringHandler) ServeHTTP(w ResponseWriter, r *Request) {
   219  	w.Header().Set("Result", string(s))
   220  }
   221  
   222  var handlers = []struct {
   223  	pattern string
   224  	msg     string
   225  }{
   226  	{"/", "Default"},
   227  	{"/someDir/", "someDir"},
   228  	{"/#/", "hash"},
   229  	{"someHost.com/someDir/", "someHost.com/someDir"},
   230  }
   231  
   232  var vtests = []struct {
   233  	url      string
   234  	expected string
   235  }{
   236  	{"http://localhost/someDir/apage", "someDir"},
   237  	{"http://localhost/%23/apage", "hash"},
   238  	{"http://localhost/otherDir/apage", "Default"},
   239  	{"http://someHost.com/someDir/apage", "someHost.com/someDir"},
   240  	{"http://otherHost.com/someDir/apage", "someDir"},
   241  	{"http://otherHost.com/aDir/apage", "Default"},
   242  	// redirections for trees
   243  	{"http://localhost/someDir", "/someDir/"},
   244  	{"http://localhost/%23", "/%23/"},
   245  	{"http://someHost.com/someDir", "/someDir/"},
   246  }
   247  
   248  func TestHostHandlers(t *testing.T) { run(t, testHostHandlers, []testMode{http1Mode}) }
   249  func testHostHandlers(t *testing.T, mode testMode) {
   250  	mux := NewServeMux()
   251  	for _, h := range handlers {
   252  		mux.Handle(h.pattern, stringHandler(h.msg))
   253  	}
   254  	ts := newClientServerTest(t, mode, mux).ts
   255  
   256  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
   257  	if err != nil {
   258  		t.Fatal(err)
   259  	}
   260  	defer conn.Close()
   261  	cc := httputil.NewClientConn(conn, nil)
   262  	for _, vt := range vtests {
   263  		var r *Response
   264  		var req Request
   265  		if req.URL, err = url.Parse(vt.url); err != nil {
   266  			t.Errorf("cannot parse url: %v", err)
   267  			continue
   268  		}
   269  		if err := cc.Write(&req); err != nil {
   270  			t.Errorf("writing request: %v", err)
   271  			continue
   272  		}
   273  		r, err := cc.Read(&req)
   274  		if err != nil {
   275  			t.Errorf("reading response: %v", err)
   276  			continue
   277  		}
   278  		switch r.StatusCode {
   279  		case StatusOK:
   280  			s := r.Header.Get("Result")
   281  			if s != vt.expected {
   282  				t.Errorf("Get(%q) = %q, want %q", vt.url, s, vt.expected)
   283  			}
   284  		case StatusMovedPermanently:
   285  			s := r.Header.Get("Location")
   286  			if s != vt.expected {
   287  				t.Errorf("Get(%q) = %q, want %q", vt.url, s, vt.expected)
   288  			}
   289  		default:
   290  			t.Errorf("Get(%q) unhandled status code %d", vt.url, r.StatusCode)
   291  		}
   292  	}
   293  }
   294  
   295  var serveMuxRegister = []struct {
   296  	pattern string
   297  	h       Handler
   298  }{
   299  	{"/dir/", serve(200)},
   300  	{"/search", serve(201)},
   301  	{"codesearch.google.com/search", serve(202)},
   302  	{"codesearch.google.com/", serve(203)},
   303  	{"example.com/", HandlerFunc(checkQueryStringHandler)},
   304  }
   305  
   306  // serve returns a handler that sends a response with the given code.
   307  func serve(code int) HandlerFunc {
   308  	return func(w ResponseWriter, r *Request) {
   309  		w.WriteHeader(code)
   310  	}
   311  }
   312  
   313  // checkQueryStringHandler checks if r.URL.RawQuery has the same value
   314  // as the URL excluding the scheme and the query string and sends 200
   315  // response code if it is, 500 otherwise.
   316  func checkQueryStringHandler(w ResponseWriter, r *Request) {
   317  	u := *r.URL
   318  	u.Scheme = "http"
   319  	u.Host = r.Host
   320  	u.RawQuery = ""
   321  	if "http://"+r.URL.RawQuery == u.String() {
   322  		w.WriteHeader(200)
   323  	} else {
   324  		w.WriteHeader(500)
   325  	}
   326  }
   327  
   328  var serveMuxTests = []struct {
   329  	method  string
   330  	host    string
   331  	path    string
   332  	code    int
   333  	pattern string
   334  }{
   335  	{"GET", "google.com", "/", 404, ""},
   336  	{"GET", "google.com", "/dir", 301, "/dir/"},
   337  	{"GET", "google.com", "/dir/", 200, "/dir/"},
   338  	{"GET", "google.com", "/dir/file", 200, "/dir/"},
   339  	{"GET", "google.com", "/search", 201, "/search"},
   340  	{"GET", "google.com", "/search/", 404, ""},
   341  	{"GET", "google.com", "/search/foo", 404, ""},
   342  	{"GET", "codesearch.google.com", "/search", 202, "codesearch.google.com/search"},
   343  	{"GET", "codesearch.google.com", "/search/", 203, "codesearch.google.com/"},
   344  	{"GET", "codesearch.google.com", "/search/foo", 203, "codesearch.google.com/"},
   345  	{"GET", "codesearch.google.com", "/", 203, "codesearch.google.com/"},
   346  	{"GET", "codesearch.google.com:443", "/", 203, "codesearch.google.com/"},
   347  	{"GET", "images.google.com", "/search", 201, "/search"},
   348  	{"GET", "images.google.com", "/search/", 404, ""},
   349  	{"GET", "images.google.com", "/search/foo", 404, ""},
   350  	{"GET", "google.com", "/../search", 301, "/search"},
   351  	{"GET", "google.com", "/dir/..", 301, ""},
   352  	{"GET", "google.com", "/dir/..", 301, ""},
   353  	{"GET", "google.com", "/dir/./file", 301, "/dir/"},
   354  
   355  	// The /foo -> /foo/ redirect applies to CONNECT requests
   356  	// but the path canonicalization does not.
   357  	{"CONNECT", "google.com", "/dir", 301, "/dir/"},
   358  	{"CONNECT", "google.com", "/../search", 404, ""},
   359  	{"CONNECT", "google.com", "/dir/..", 200, "/dir/"},
   360  	{"CONNECT", "google.com", "/dir/..", 200, "/dir/"},
   361  	{"CONNECT", "google.com", "/dir/./file", 200, "/dir/"},
   362  }
   363  
   364  func TestServeMuxHandler(t *testing.T) {
   365  	setParallel(t)
   366  	mux := NewServeMux()
   367  	for _, e := range serveMuxRegister {
   368  		mux.Handle(e.pattern, e.h)
   369  	}
   370  
   371  	for _, tt := range serveMuxTests {
   372  		r := &Request{
   373  			Method: tt.method,
   374  			Host:   tt.host,
   375  			URL: &url.URL{
   376  				Path: tt.path,
   377  			},
   378  		}
   379  		h, pattern := mux.Handler(r)
   380  		rr := httptest.NewRecorder()
   381  		h.ServeHTTP(rr, r)
   382  		if pattern != tt.pattern || rr.Code != tt.code {
   383  			t.Errorf("%s %s %s = %d, %q, want %d, %q", tt.method, tt.host, tt.path, rr.Code, pattern, tt.code, tt.pattern)
   384  		}
   385  	}
   386  }
   387  
   388  // Issue 24297
   389  func TestServeMuxHandleFuncWithNilHandler(t *testing.T) {
   390  	setParallel(t)
   391  	defer func() {
   392  		if err := recover(); err == nil {
   393  			t.Error("expected call to mux.HandleFunc to panic")
   394  		}
   395  	}()
   396  	mux := NewServeMux()
   397  	mux.HandleFunc("/", nil)
   398  }
   399  
   400  var serveMuxTests2 = []struct {
   401  	method  string
   402  	host    string
   403  	url     string
   404  	code    int
   405  	redirOk bool
   406  }{
   407  	{"GET", "google.com", "/", 404, false},
   408  	{"GET", "example.com", "/test/?example.com/test/", 200, false},
   409  	{"GET", "example.com", "test/?example.com/test/", 200, true},
   410  }
   411  
   412  // TestServeMuxHandlerRedirects tests that automatic redirects generated by
   413  // mux.Handler() shouldn't clear the request's query string.
   414  func TestServeMuxHandlerRedirects(t *testing.T) {
   415  	setParallel(t)
   416  	mux := NewServeMux()
   417  	for _, e := range serveMuxRegister {
   418  		mux.Handle(e.pattern, e.h)
   419  	}
   420  
   421  	for _, tt := range serveMuxTests2 {
   422  		tries := 1 // expect at most 1 redirection if redirOk is true.
   423  		turl := tt.url
   424  		for {
   425  			u, e := url.Parse(turl)
   426  			if e != nil {
   427  				t.Fatal(e)
   428  			}
   429  			r := &Request{
   430  				Method: tt.method,
   431  				Host:   tt.host,
   432  				URL:    u,
   433  			}
   434  			h, _ := mux.Handler(r)
   435  			rr := httptest.NewRecorder()
   436  			h.ServeHTTP(rr, r)
   437  			if rr.Code != 301 {
   438  				if rr.Code != tt.code {
   439  					t.Errorf("%s %s %s = %d, want %d", tt.method, tt.host, tt.url, rr.Code, tt.code)
   440  				}
   441  				break
   442  			}
   443  			if !tt.redirOk {
   444  				t.Errorf("%s %s %s, unexpected redirect", tt.method, tt.host, tt.url)
   445  				break
   446  			}
   447  			turl = rr.HeaderMap.Get("Location")
   448  			tries--
   449  		}
   450  		if tries < 0 {
   451  			t.Errorf("%s %s %s, too many redirects", tt.method, tt.host, tt.url)
   452  		}
   453  	}
   454  }
   455  
   456  // Tests for https://golang.org/issue/900
   457  func TestMuxRedirectLeadingSlashes(t *testing.T) {
   458  	setParallel(t)
   459  	paths := []string{"//foo.txt", "///foo.txt", "/../../foo.txt"}
   460  	for _, path := range paths {
   461  		req, err := ReadRequest(bufio.NewReader(strings.NewReader("GET " + path + " HTTP/1.1\r\nHost: test\r\n\r\n")))
   462  		if err != nil {
   463  			t.Errorf("%s", err)
   464  		}
   465  		mux := NewServeMux()
   466  		resp := httptest.NewRecorder()
   467  
   468  		mux.ServeHTTP(resp, req)
   469  
   470  		if loc, expected := resp.Header().Get("Location"), "/foo.txt"; loc != expected {
   471  			t.Errorf("Expected Location header set to %q; got %q", expected, loc)
   472  			return
   473  		}
   474  
   475  		if code, expected := resp.Code, StatusMovedPermanently; code != expected {
   476  			t.Errorf("Expected response code of StatusMovedPermanently; got %d", code)
   477  			return
   478  		}
   479  	}
   480  }
   481  
   482  // Test that the special cased "/route" redirect
   483  // implicitly created by a registered "/route/"
   484  // properly sets the query string in the redirect URL.
   485  // See Issue 17841.
   486  func TestServeWithSlashRedirectKeepsQueryString(t *testing.T) {
   487  	run(t, testServeWithSlashRedirectKeepsQueryString, []testMode{http1Mode})
   488  }
   489  func testServeWithSlashRedirectKeepsQueryString(t *testing.T, mode testMode) {
   490  	writeBackQuery := func(w ResponseWriter, r *Request) {
   491  		fmt.Fprintf(w, "%s", r.URL.RawQuery)
   492  	}
   493  
   494  	mux := NewServeMux()
   495  	mux.HandleFunc("/testOne", writeBackQuery)
   496  	mux.HandleFunc("/testTwo/", writeBackQuery)
   497  	mux.HandleFunc("/testThree", writeBackQuery)
   498  	mux.HandleFunc("/testThree/", func(w ResponseWriter, r *Request) {
   499  		fmt.Fprintf(w, "%s:bar", r.URL.RawQuery)
   500  	})
   501  
   502  	ts := newClientServerTest(t, mode, mux).ts
   503  
   504  	tests := [...]struct {
   505  		path     string
   506  		method   string
   507  		want     string
   508  		statusOk bool
   509  	}{
   510  		0: {"/testOne?this=that", "GET", "this=that", true},
   511  		1: {"/testTwo?foo=bar", "GET", "foo=bar", true},
   512  		2: {"/testTwo?a=1&b=2&a=3", "GET", "a=1&b=2&a=3", true},
   513  		3: {"/testTwo?", "GET", "", true},
   514  		4: {"/testThree?foo", "GET", "foo", true},
   515  		5: {"/testThree/?foo", "GET", "foo:bar", true},
   516  		6: {"/testThree?foo", "CONNECT", "foo", true},
   517  		7: {"/testThree/?foo", "CONNECT", "foo:bar", true},
   518  
   519  		// canonicalization or not
   520  		8: {"/testOne/foo/..?foo", "GET", "foo", true},
   521  		9: {"/testOne/foo/..?foo", "CONNECT", "404 page not found\n", false},
   522  	}
   523  
   524  	for i, tt := range tests {
   525  		req, _ := NewRequest(tt.method, ts.URL+tt.path, nil)
   526  		res, err := ts.Client().Do(req)
   527  		if err != nil {
   528  			continue
   529  		}
   530  		slurp, _ := io.ReadAll(res.Body)
   531  		res.Body.Close()
   532  		if !tt.statusOk {
   533  			if got, want := res.StatusCode, 404; got != want {
   534  				t.Errorf("#%d: Status = %d; want = %d", i, got, want)
   535  			}
   536  		}
   537  		if got, want := string(slurp), tt.want; got != want {
   538  			t.Errorf("#%d: Body = %q; want = %q", i, got, want)
   539  		}
   540  	}
   541  }
   542  
   543  func TestServeWithSlashRedirectForHostPatterns(t *testing.T) {
   544  	setParallel(t)
   545  
   546  	mux := NewServeMux()
   547  	mux.Handle("example.com/pkg/foo/", stringHandler("example.com/pkg/foo/"))
   548  	mux.Handle("example.com/pkg/bar", stringHandler("example.com/pkg/bar"))
   549  	mux.Handle("example.com/pkg/bar/", stringHandler("example.com/pkg/bar/"))
   550  	mux.Handle("example.com:3000/pkg/connect/", stringHandler("example.com:3000/pkg/connect/"))
   551  	mux.Handle("example.com:9000/", stringHandler("example.com:9000/"))
   552  	mux.Handle("/pkg/baz/", stringHandler("/pkg/baz/"))
   553  
   554  	tests := []struct {
   555  		method string
   556  		url    string
   557  		code   int
   558  		loc    string
   559  		want   string
   560  	}{
   561  		{"GET", "http://example.com/", 404, "", ""},
   562  		{"GET", "http://example.com/pkg/foo", 301, "/pkg/foo/", ""},
   563  		{"GET", "http://example.com/pkg/bar", 200, "", "example.com/pkg/bar"},
   564  		{"GET", "http://example.com/pkg/bar/", 200, "", "example.com/pkg/bar/"},
   565  		{"GET", "http://example.com/pkg/baz", 301, "/pkg/baz/", ""},
   566  		{"GET", "http://example.com:3000/pkg/foo", 301, "/pkg/foo/", ""},
   567  		{"CONNECT", "http://example.com/", 404, "", ""},
   568  		{"CONNECT", "http://example.com:3000/", 404, "", ""},
   569  		{"CONNECT", "http://example.com:9000/", 200, "", "example.com:9000/"},
   570  		{"CONNECT", "http://example.com/pkg/foo", 301, "/pkg/foo/", ""},
   571  		{"CONNECT", "http://example.com:3000/pkg/foo", 404, "", ""},
   572  		{"CONNECT", "http://example.com:3000/pkg/baz", 301, "/pkg/baz/", ""},
   573  		{"CONNECT", "http://example.com:3000/pkg/connect", 301, "/pkg/connect/", ""},
   574  	}
   575  
   576  	for i, tt := range tests {
   577  		req, _ := NewRequest(tt.method, tt.url, nil)
   578  		w := httptest.NewRecorder()
   579  		mux.ServeHTTP(w, req)
   580  
   581  		if got, want := w.Code, tt.code; got != want {
   582  			t.Errorf("#%d: Status = %d; want = %d", i, got, want)
   583  		}
   584  
   585  		if tt.code == 301 {
   586  			if got, want := w.HeaderMap.Get("Location"), tt.loc; got != want {
   587  				t.Errorf("#%d: Location = %q; want = %q", i, got, want)
   588  			}
   589  		} else {
   590  			if got, want := w.HeaderMap.Get("Result"), tt.want; got != want {
   591  				t.Errorf("#%d: Result = %q; want = %q", i, got, want)
   592  			}
   593  		}
   594  	}
   595  }
   596  
   597  func TestShouldRedirectConcurrency(t *testing.T) { run(t, testShouldRedirectConcurrency) }
   598  func testShouldRedirectConcurrency(t *testing.T, mode testMode) {
   599  	mux := NewServeMux()
   600  	newClientServerTest(t, mode, mux)
   601  	mux.HandleFunc("/", func(w ResponseWriter, r *Request) {})
   602  }
   603  
   604  func BenchmarkServeMux(b *testing.B)           { benchmarkServeMux(b, true) }
   605  func BenchmarkServeMux_SkipServe(b *testing.B) { benchmarkServeMux(b, false) }
   606  func benchmarkServeMux(b *testing.B, runHandler bool) {
   607  	type test struct {
   608  		path string
   609  		code int
   610  		req  *Request
   611  	}
   612  
   613  	// Build example handlers and requests
   614  	var tests []test
   615  	endpoints := []string{"search", "dir", "file", "change", "count", "s"}
   616  	for _, e := range endpoints {
   617  		for i := 200; i < 230; i++ {
   618  			p := fmt.Sprintf("/%s/%d/", e, i)
   619  			tests = append(tests, test{
   620  				path: p,
   621  				code: i,
   622  				req:  &Request{Method: "GET", Host: "localhost", URL: &url.URL{Path: p}},
   623  			})
   624  		}
   625  	}
   626  	mux := NewServeMux()
   627  	for _, tt := range tests {
   628  		mux.Handle(tt.path, serve(tt.code))
   629  	}
   630  
   631  	rw := httptest.NewRecorder()
   632  	b.ReportAllocs()
   633  	b.ResetTimer()
   634  	for i := 0; i < b.N; i++ {
   635  		for _, tt := range tests {
   636  			*rw = httptest.ResponseRecorder{}
   637  			h, pattern := mux.Handler(tt.req)
   638  			if runHandler {
   639  				h.ServeHTTP(rw, tt.req)
   640  				if pattern != tt.path || rw.Code != tt.code {
   641  					b.Fatalf("got %d, %q, want %d, %q", rw.Code, pattern, tt.code, tt.path)
   642  				}
   643  			}
   644  		}
   645  	}
   646  }
   647  
   648  func TestServerTimeouts(t *testing.T) { run(t, testServerTimeouts, []testMode{http1Mode}) }
   649  func testServerTimeouts(t *testing.T, mode testMode) {
   650  	// Try three times, with increasing timeouts.
   651  	tries := []time.Duration{250 * time.Millisecond, 500 * time.Millisecond, 1 * time.Second}
   652  	for i, timeout := range tries {
   653  		err := testServerTimeoutsWithTimeout(t, timeout, mode)
   654  		if err == nil {
   655  			return
   656  		}
   657  		t.Logf("failed at %v: %v", timeout, err)
   658  		if i != len(tries)-1 {
   659  			t.Logf("retrying at %v ...", tries[i+1])
   660  		}
   661  	}
   662  	t.Fatal("all attempts failed")
   663  }
   664  
   665  func testServerTimeoutsWithTimeout(t *testing.T, timeout time.Duration, mode testMode) error {
   666  	reqNum := 0
   667  	ts := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   668  		reqNum++
   669  		fmt.Fprintf(res, "req=%d", reqNum)
   670  	}), func(ts *httptest.Server) {
   671  		ts.Config.ReadTimeout = timeout
   672  		ts.Config.WriteTimeout = timeout
   673  	}).ts
   674  
   675  	// Hit the HTTP server successfully.
   676  	c := ts.Client()
   677  	r, err := c.Get(ts.URL)
   678  	if err != nil {
   679  		return fmt.Errorf("http Get #1: %v", err)
   680  	}
   681  	got, err := io.ReadAll(r.Body)
   682  	expected := "req=1"
   683  	if string(got) != expected || err != nil {
   684  		return fmt.Errorf("Unexpected response for request #1; got %q ,%v; expected %q, nil",
   685  			string(got), err, expected)
   686  	}
   687  
   688  	// Slow client that should timeout.
   689  	t1 := time.Now()
   690  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
   691  	if err != nil {
   692  		return fmt.Errorf("Dial: %v", err)
   693  	}
   694  	buf := make([]byte, 1)
   695  	n, err := conn.Read(buf)
   696  	conn.Close()
   697  	latency := time.Since(t1)
   698  	if n != 0 || err != io.EOF {
   699  		return fmt.Errorf("Read = %v, %v, wanted %v, %v", n, err, 0, io.EOF)
   700  	}
   701  	minLatency := timeout / 5 * 4
   702  	if latency < minLatency {
   703  		return fmt.Errorf("got EOF after %s, want >= %s", latency, minLatency)
   704  	}
   705  
   706  	// Hit the HTTP server successfully again, verifying that the
   707  	// previous slow connection didn't run our handler.  (that we
   708  	// get "req=2", not "req=3")
   709  	r, err = c.Get(ts.URL)
   710  	if err != nil {
   711  		return fmt.Errorf("http Get #2: %v", err)
   712  	}
   713  	got, err = io.ReadAll(r.Body)
   714  	r.Body.Close()
   715  	expected = "req=2"
   716  	if string(got) != expected || err != nil {
   717  		return fmt.Errorf("Get #2 got %q, %v, want %q, nil", string(got), err, expected)
   718  	}
   719  
   720  	if !testing.Short() {
   721  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
   722  		if err != nil {
   723  			return fmt.Errorf("long Dial: %v", err)
   724  		}
   725  		defer conn.Close()
   726  		go io.Copy(io.Discard, conn)
   727  		for i := 0; i < 5; i++ {
   728  			_, err := conn.Write([]byte("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"))
   729  			if err != nil {
   730  				return fmt.Errorf("on write %d: %v", i, err)
   731  			}
   732  			time.Sleep(timeout / 2)
   733  		}
   734  	}
   735  	return nil
   736  }
   737  
   738  func TestServerReadTimeout(t *testing.T) { run(t, testServerReadTimeout) }
   739  func testServerReadTimeout(t *testing.T, mode testMode) {
   740  	respBody := "response body"
   741  	for timeout := 5 * time.Millisecond; ; timeout *= 2 {
   742  		cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   743  			_, err := io.Copy(io.Discard, req.Body)
   744  			if !errors.Is(err, os.ErrDeadlineExceeded) {
   745  				t.Errorf("server timed out reading request body: got err %v; want os.ErrDeadlineExceeded", err)
   746  			}
   747  			res.Write([]byte(respBody))
   748  		}), func(ts *httptest.Server) {
   749  			ts.Config.ReadHeaderTimeout = -1 // don't time out while reading headers
   750  			ts.Config.ReadTimeout = timeout
   751  		})
   752  		pr, pw := io.Pipe()
   753  		res, err := cst.c.Post(cst.ts.URL, "text/apocryphal", pr)
   754  		if err != nil {
   755  			t.Logf("Get error, retrying: %v", err)
   756  			cst.close()
   757  			continue
   758  		}
   759  		defer res.Body.Close()
   760  		got, err := io.ReadAll(res.Body)
   761  		if string(got) != respBody || err != nil {
   762  			t.Errorf("client read response body: %q, %v; want %q, nil", string(got), err, respBody)
   763  		}
   764  		pw.Close()
   765  		break
   766  	}
   767  }
   768  
   769  func TestServerWriteTimeout(t *testing.T) { run(t, testServerWriteTimeout) }
   770  func testServerWriteTimeout(t *testing.T, mode testMode) {
   771  	for timeout := 5 * time.Millisecond; ; timeout *= 2 {
   772  		errc := make(chan error, 2)
   773  		cst := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   774  			errc <- nil
   775  			_, err := io.Copy(res, neverEnding('a'))
   776  			errc <- err
   777  		}), func(ts *httptest.Server) {
   778  			ts.Config.WriteTimeout = timeout
   779  		})
   780  		res, err := cst.c.Get(cst.ts.URL)
   781  		if err != nil {
   782  			// Probably caused by the write timeout expiring before the handler runs.
   783  			t.Logf("Get error, retrying: %v", err)
   784  			cst.close()
   785  			continue
   786  		}
   787  		defer res.Body.Close()
   788  		_, err = io.Copy(io.Discard, res.Body)
   789  		if err == nil {
   790  			t.Errorf("client reading from truncated request body: got nil error, want non-nil")
   791  		}
   792  		select {
   793  		case <-errc:
   794  			err = <-errc // io.Copy error
   795  			if !errors.Is(err, os.ErrDeadlineExceeded) {
   796  				t.Errorf("server timed out writing request body: got err %v; want os.ErrDeadlineExceeded", err)
   797  			}
   798  			return
   799  		default:
   800  			// The write timeout expired before the handler started.
   801  			t.Logf("handler didn't run, retrying")
   802  			cst.close()
   803  		}
   804  	}
   805  }
   806  
   807  // Test that the HTTP/2 server handles Server.WriteTimeout (Issue 18437)
   808  func TestWriteDeadlineExtendedOnNewRequest(t *testing.T) {
   809  	run(t, testWriteDeadlineExtendedOnNewRequest)
   810  }
   811  func testWriteDeadlineExtendedOnNewRequest(t *testing.T, mode testMode) {
   812  	if testing.Short() {
   813  		t.Skip("skipping in short mode")
   814  	}
   815  	ts := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {}),
   816  		func(ts *httptest.Server) {
   817  			ts.Config.WriteTimeout = 250 * time.Millisecond
   818  		},
   819  	).ts
   820  
   821  	c := ts.Client()
   822  
   823  	for i := 1; i <= 3; i++ {
   824  		req, err := NewRequest("GET", ts.URL, nil)
   825  		if err != nil {
   826  			t.Fatal(err)
   827  		}
   828  
   829  		r, err := c.Do(req)
   830  		if err != nil {
   831  			t.Fatalf("http2 Get #%d: %v", i, err)
   832  		}
   833  		r.Body.Close()
   834  		time.Sleep(ts.Config.WriteTimeout / 2)
   835  	}
   836  }
   837  
   838  // tryTimeouts runs testFunc with increasing timeouts. Test passes on first success,
   839  // and fails if all timeouts fail.
   840  func tryTimeouts(t *testing.T, testFunc func(timeout time.Duration) error) {
   841  	tries := []time.Duration{250 * time.Millisecond, 500 * time.Millisecond, 1 * time.Second}
   842  	for i, timeout := range tries {
   843  		err := testFunc(timeout)
   844  		if err == nil {
   845  			return
   846  		}
   847  		t.Logf("failed at %v: %v", timeout, err)
   848  		if i != len(tries)-1 {
   849  			t.Logf("retrying at %v ...", tries[i+1])
   850  		}
   851  	}
   852  	t.Fatal("all attempts failed")
   853  }
   854  
   855  // Test that the HTTP/2 server RSTs stream on slow write.
   856  func TestWriteDeadlineEnforcedPerStream(t *testing.T) {
   857  	if testing.Short() {
   858  		t.Skip("skipping in short mode")
   859  	}
   860  	setParallel(t)
   861  	run(t, func(t *testing.T, mode testMode) {
   862  		tryTimeouts(t, func(timeout time.Duration) error {
   863  			return testWriteDeadlineEnforcedPerStream(t, mode, timeout)
   864  		})
   865  	})
   866  }
   867  
   868  func testWriteDeadlineEnforcedPerStream(t *testing.T, mode testMode, timeout time.Duration) error {
   869  	reqNum := 0
   870  	ts := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   871  		reqNum++
   872  		if reqNum == 1 {
   873  			return // first request succeeds
   874  		}
   875  		time.Sleep(timeout) // second request times out
   876  	}), func(ts *httptest.Server) {
   877  		ts.Config.WriteTimeout = timeout / 2
   878  	}).ts
   879  
   880  	c := ts.Client()
   881  
   882  	req, err := NewRequest("GET", ts.URL, nil)
   883  	if err != nil {
   884  		return fmt.Errorf("NewRequest: %v", err)
   885  	}
   886  	r, err := c.Do(req)
   887  	if err != nil {
   888  		return fmt.Errorf("Get #1: %v", err)
   889  	}
   890  	r.Body.Close()
   891  
   892  	req, err = NewRequest("GET", ts.URL, nil)
   893  	if err != nil {
   894  		return fmt.Errorf("NewRequest: %v", err)
   895  	}
   896  	r, err = c.Do(req)
   897  	if err == nil {
   898  		r.Body.Close()
   899  		return fmt.Errorf("Get #2 expected error, got nil")
   900  	}
   901  	if mode == http2Mode {
   902  		expected := "stream ID 3; INTERNAL_ERROR" // client IDs are odd, second stream should be 3
   903  		if !strings.Contains(err.Error(), expected) {
   904  			return fmt.Errorf("http2 Get #2: expected error to contain %q, got %q", expected, err)
   905  		}
   906  	}
   907  	return nil
   908  }
   909  
   910  // Test that the HTTP/2 server does not send RST when WriteDeadline not set.
   911  func TestNoWriteDeadline(t *testing.T) {
   912  	if testing.Short() {
   913  		t.Skip("skipping in short mode")
   914  	}
   915  	setParallel(t)
   916  	defer afterTest(t)
   917  	run(t, func(t *testing.T, mode testMode) {
   918  		tryTimeouts(t, func(timeout time.Duration) error {
   919  			return testNoWriteDeadline(t, mode, timeout)
   920  		})
   921  	})
   922  }
   923  
   924  func testNoWriteDeadline(t *testing.T, mode testMode, timeout time.Duration) error {
   925  	reqNum := 0
   926  	ts := newClientServerTest(t, mode, HandlerFunc(func(res ResponseWriter, req *Request) {
   927  		reqNum++
   928  		if reqNum == 1 {
   929  			return // first request succeeds
   930  		}
   931  		time.Sleep(timeout) // second request timesout
   932  	})).ts
   933  
   934  	c := ts.Client()
   935  
   936  	for i := 0; i < 2; i++ {
   937  		req, err := NewRequest("GET", ts.URL, nil)
   938  		if err != nil {
   939  			return fmt.Errorf("NewRequest: %v", err)
   940  		}
   941  		r, err := c.Do(req)
   942  		if err != nil {
   943  			return fmt.Errorf("Get #%d: %v", i, err)
   944  		}
   945  		r.Body.Close()
   946  	}
   947  	return nil
   948  }
   949  
   950  // golang.org/issue/4741 -- setting only a write timeout that triggers
   951  // shouldn't cause a handler to block forever on reads (next HTTP
   952  // request) that will never happen.
   953  func TestOnlyWriteTimeout(t *testing.T) { run(t, testOnlyWriteTimeout, []testMode{http1Mode}) }
   954  func testOnlyWriteTimeout(t *testing.T, mode testMode) {
   955  	var (
   956  		mu   sync.RWMutex
   957  		conn net.Conn
   958  	)
   959  	var afterTimeoutErrc = make(chan error, 1)
   960  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, req *Request) {
   961  		buf := make([]byte, 512<<10)
   962  		_, err := w.Write(buf)
   963  		if err != nil {
   964  			t.Errorf("handler Write error: %v", err)
   965  			return
   966  		}
   967  		mu.RLock()
   968  		defer mu.RUnlock()
   969  		if conn == nil {
   970  			t.Error("no established connection found")
   971  			return
   972  		}
   973  		conn.SetWriteDeadline(time.Now().Add(-30 * time.Second))
   974  		_, err = w.Write(buf)
   975  		afterTimeoutErrc <- err
   976  	}), func(ts *httptest.Server) {
   977  		ts.Listener = trackLastConnListener{ts.Listener, &mu, &conn}
   978  	}).ts
   979  
   980  	c := ts.Client()
   981  
   982  	err := func() error {
   983  		res, err := c.Get(ts.URL)
   984  		if err != nil {
   985  			return err
   986  		}
   987  		_, err = io.Copy(io.Discard, res.Body)
   988  		res.Body.Close()
   989  		return err
   990  	}()
   991  	if err == nil {
   992  		t.Errorf("expected an error copying body from Get request")
   993  	}
   994  
   995  	if err := <-afterTimeoutErrc; err == nil {
   996  		t.Error("expected write error after timeout")
   997  	}
   998  }
   999  
  1000  // trackLastConnListener tracks the last net.Conn that was accepted.
  1001  type trackLastConnListener struct {
  1002  	net.Listener
  1003  
  1004  	mu   *sync.RWMutex
  1005  	last *net.Conn // destination
  1006  }
  1007  
  1008  func (l trackLastConnListener) Accept() (c net.Conn, err error) {
  1009  	c, err = l.Listener.Accept()
  1010  	if err == nil {
  1011  		l.mu.Lock()
  1012  		*l.last = c
  1013  		l.mu.Unlock()
  1014  	}
  1015  	return
  1016  }
  1017  
  1018  // TestIdentityResponse verifies that a handler can unset
  1019  func TestIdentityResponse(t *testing.T) { run(t, testIdentityResponse) }
  1020  func testIdentityResponse(t *testing.T, mode testMode) {
  1021  	if mode == http2Mode {
  1022  		t.Skip("https://go.dev/issue/56019")
  1023  	}
  1024  
  1025  	handler := HandlerFunc(func(rw ResponseWriter, req *Request) {
  1026  		rw.Header().Set("Content-Length", "3")
  1027  		rw.Header().Set("Transfer-Encoding", req.FormValue("te"))
  1028  		switch {
  1029  		case req.FormValue("overwrite") == "1":
  1030  			_, err := rw.Write([]byte("foo TOO LONG"))
  1031  			if err != ErrContentLength {
  1032  				t.Errorf("expected ErrContentLength; got %v", err)
  1033  			}
  1034  		case req.FormValue("underwrite") == "1":
  1035  			rw.Header().Set("Content-Length", "500")
  1036  			rw.Write([]byte("too short"))
  1037  		default:
  1038  			rw.Write([]byte("foo"))
  1039  		}
  1040  	})
  1041  
  1042  	ts := newClientServerTest(t, mode, handler).ts
  1043  	c := ts.Client()
  1044  
  1045  	// Note: this relies on the assumption (which is true) that
  1046  	// Get sends HTTP/1.1 or greater requests. Otherwise the
  1047  	// server wouldn't have the choice to send back chunked
  1048  	// responses.
  1049  	for _, te := range []string{"", "identity"} {
  1050  		url := ts.URL + "/?te=" + te
  1051  		res, err := c.Get(url)
  1052  		if err != nil {
  1053  			t.Fatalf("error with Get of %s: %v", url, err)
  1054  		}
  1055  		if cl, expected := res.ContentLength, int64(3); cl != expected {
  1056  			t.Errorf("for %s expected res.ContentLength of %d; got %d", url, expected, cl)
  1057  		}
  1058  		if cl, expected := res.Header.Get("Content-Length"), "3"; cl != expected {
  1059  			t.Errorf("for %s expected Content-Length header of %q; got %q", url, expected, cl)
  1060  		}
  1061  		if tl, expected := len(res.TransferEncoding), 0; tl != expected {
  1062  			t.Errorf("for %s expected len(res.TransferEncoding) of %d; got %d (%v)",
  1063  				url, expected, tl, res.TransferEncoding)
  1064  		}
  1065  		res.Body.Close()
  1066  	}
  1067  
  1068  	// Verify that ErrContentLength is returned
  1069  	url := ts.URL + "/?overwrite=1"
  1070  	res, err := c.Get(url)
  1071  	if err != nil {
  1072  		t.Fatalf("error with Get of %s: %v", url, err)
  1073  	}
  1074  	res.Body.Close()
  1075  
  1076  	if mode != http1Mode {
  1077  		return
  1078  	}
  1079  
  1080  	// Verify that the connection is closed when the declared Content-Length
  1081  	// is larger than what the handler wrote.
  1082  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1083  	if err != nil {
  1084  		t.Fatalf("error dialing: %v", err)
  1085  	}
  1086  	_, err = conn.Write([]byte("GET /?underwrite=1 HTTP/1.1\r\nHost: foo\r\n\r\n"))
  1087  	if err != nil {
  1088  		t.Fatalf("error writing: %v", err)
  1089  	}
  1090  
  1091  	// The ReadAll will hang for a failing test.
  1092  	got, _ := io.ReadAll(conn)
  1093  	expectedSuffix := "\r\n\r\ntoo short"
  1094  	if !strings.HasSuffix(string(got), expectedSuffix) {
  1095  		t.Errorf("Expected output to end with %q; got response body %q",
  1096  			expectedSuffix, string(got))
  1097  	}
  1098  }
  1099  
  1100  func testTCPConnectionCloses(t *testing.T, req string, h Handler) {
  1101  	setParallel(t)
  1102  	s := newClientServerTest(t, http1Mode, h).ts
  1103  
  1104  	conn, err := net.Dial("tcp", s.Listener.Addr().String())
  1105  	if err != nil {
  1106  		t.Fatal("dial error:", err)
  1107  	}
  1108  	defer conn.Close()
  1109  
  1110  	_, err = fmt.Fprint(conn, req)
  1111  	if err != nil {
  1112  		t.Fatal("print error:", err)
  1113  	}
  1114  
  1115  	r := bufio.NewReader(conn)
  1116  	res, err := ReadResponse(r, &Request{Method: "GET"})
  1117  	if err != nil {
  1118  		t.Fatal("ReadResponse error:", err)
  1119  	}
  1120  
  1121  	_, err = io.ReadAll(r)
  1122  	if err != nil {
  1123  		t.Fatal("read error:", err)
  1124  	}
  1125  
  1126  	if !res.Close {
  1127  		t.Errorf("Response.Close = false; want true")
  1128  	}
  1129  }
  1130  
  1131  func testTCPConnectionStaysOpen(t *testing.T, req string, handler Handler) {
  1132  	setParallel(t)
  1133  	ts := newClientServerTest(t, http1Mode, handler).ts
  1134  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1135  	if err != nil {
  1136  		t.Fatal(err)
  1137  	}
  1138  	defer conn.Close()
  1139  	br := bufio.NewReader(conn)
  1140  	for i := 0; i < 2; i++ {
  1141  		if _, err := io.WriteString(conn, req); err != nil {
  1142  			t.Fatal(err)
  1143  		}
  1144  		res, err := ReadResponse(br, nil)
  1145  		if err != nil {
  1146  			t.Fatalf("res %d: %v", i+1, err)
  1147  		}
  1148  		if _, err := io.Copy(io.Discard, res.Body); err != nil {
  1149  			t.Fatalf("res %d body copy: %v", i+1, err)
  1150  		}
  1151  		res.Body.Close()
  1152  	}
  1153  }
  1154  
  1155  // TestServeHTTP10Close verifies that HTTP/1.0 requests won't be kept alive.
  1156  func TestServeHTTP10Close(t *testing.T) {
  1157  	testTCPConnectionCloses(t, "GET / HTTP/1.0\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1158  		ServeFile(w, r, "testdata/file")
  1159  	}))
  1160  }
  1161  
  1162  // TestClientCanClose verifies that clients can also force a connection to close.
  1163  func TestClientCanClose(t *testing.T) {
  1164  	testTCPConnectionCloses(t, "GET / HTTP/1.1\r\nHost: foo\r\nConnection: close\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1165  		// Nothing.
  1166  	}))
  1167  }
  1168  
  1169  // TestHandlersCanSetConnectionClose verifies that handlers can force a connection to close,
  1170  // even for HTTP/1.1 requests.
  1171  func TestHandlersCanSetConnectionClose11(t *testing.T) {
  1172  	testTCPConnectionCloses(t, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1173  		w.Header().Set("Connection", "close")
  1174  	}))
  1175  }
  1176  
  1177  func TestHandlersCanSetConnectionClose10(t *testing.T) {
  1178  	testTCPConnectionCloses(t, "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1179  		w.Header().Set("Connection", "close")
  1180  	}))
  1181  }
  1182  
  1183  func TestHTTP2UpgradeClosesConnection(t *testing.T) {
  1184  	testTCPConnectionCloses(t, "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n", HandlerFunc(func(w ResponseWriter, r *Request) {
  1185  		// Nothing. (if not hijacked, the server should close the connection
  1186  		// afterwards)
  1187  	}))
  1188  }
  1189  
  1190  func send204(w ResponseWriter, r *Request) { w.WriteHeader(204) }
  1191  func send304(w ResponseWriter, r *Request) { w.WriteHeader(304) }
  1192  
  1193  // Issue 15647: 204 responses can't have bodies, so HTTP/1.0 keep-alive conns should stay open.
  1194  func TestHTTP10KeepAlive204Response(t *testing.T) {
  1195  	testTCPConnectionStaysOpen(t, "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n", HandlerFunc(send204))
  1196  }
  1197  
  1198  func TestHTTP11KeepAlive204Response(t *testing.T) {
  1199  	testTCPConnectionStaysOpen(t, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n", HandlerFunc(send204))
  1200  }
  1201  
  1202  func TestHTTP10KeepAlive304Response(t *testing.T) {
  1203  	testTCPConnectionStaysOpen(t,
  1204  		"GET / HTTP/1.0\r\nConnection: keep-alive\r\nIf-Modified-Since: Mon, 02 Jan 2006 15:04:05 GMT\r\n\r\n",
  1205  		HandlerFunc(send304))
  1206  }
  1207  
  1208  // Issue 15703
  1209  func TestKeepAliveFinalChunkWithEOF(t *testing.T) { run(t, testKeepAliveFinalChunkWithEOF) }
  1210  func testKeepAliveFinalChunkWithEOF(t *testing.T, mode testMode) {
  1211  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1212  		w.(Flusher).Flush() // force chunked encoding
  1213  		w.Write([]byte("{\"Addr\": \"" + r.RemoteAddr + "\"}"))
  1214  	}))
  1215  	type data struct {
  1216  		Addr string
  1217  	}
  1218  	var addrs [2]data
  1219  	for i := range addrs {
  1220  		res, err := cst.c.Get(cst.ts.URL)
  1221  		if err != nil {
  1222  			t.Fatal(err)
  1223  		}
  1224  		if err := json.NewDecoder(res.Body).Decode(&addrs[i]); err != nil {
  1225  			t.Fatal(err)
  1226  		}
  1227  		if addrs[i].Addr == "" {
  1228  			t.Fatal("no address")
  1229  		}
  1230  		res.Body.Close()
  1231  	}
  1232  	if addrs[0] != addrs[1] {
  1233  		t.Fatalf("connection not reused")
  1234  	}
  1235  }
  1236  
  1237  func TestSetsRemoteAddr(t *testing.T) { run(t, testSetsRemoteAddr) }
  1238  func testSetsRemoteAddr(t *testing.T, mode testMode) {
  1239  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1240  		fmt.Fprintf(w, "%s", r.RemoteAddr)
  1241  	}))
  1242  
  1243  	res, err := cst.c.Get(cst.ts.URL)
  1244  	if err != nil {
  1245  		t.Fatalf("Get error: %v", err)
  1246  	}
  1247  	body, err := io.ReadAll(res.Body)
  1248  	if err != nil {
  1249  		t.Fatalf("ReadAll error: %v", err)
  1250  	}
  1251  	ip := string(body)
  1252  	if !strings.HasPrefix(ip, "127.0.0.1:") && !strings.HasPrefix(ip, "[::1]:") {
  1253  		t.Fatalf("Expected local addr; got %q", ip)
  1254  	}
  1255  }
  1256  
  1257  type blockingRemoteAddrListener struct {
  1258  	net.Listener
  1259  	conns chan<- net.Conn
  1260  }
  1261  
  1262  func (l *blockingRemoteAddrListener) Accept() (net.Conn, error) {
  1263  	c, err := l.Listener.Accept()
  1264  	if err != nil {
  1265  		return nil, err
  1266  	}
  1267  	brac := &blockingRemoteAddrConn{
  1268  		Conn:  c,
  1269  		addrs: make(chan net.Addr, 1),
  1270  	}
  1271  	l.conns <- brac
  1272  	return brac, nil
  1273  }
  1274  
  1275  type blockingRemoteAddrConn struct {
  1276  	net.Conn
  1277  	addrs chan net.Addr
  1278  }
  1279  
  1280  func (c *blockingRemoteAddrConn) RemoteAddr() net.Addr {
  1281  	return <-c.addrs
  1282  }
  1283  
  1284  // Issue 12943
  1285  func TestServerAllowsBlockingRemoteAddr(t *testing.T) {
  1286  	run(t, testServerAllowsBlockingRemoteAddr, []testMode{http1Mode})
  1287  }
  1288  func testServerAllowsBlockingRemoteAddr(t *testing.T, mode testMode) {
  1289  	conns := make(chan net.Conn)
  1290  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1291  		fmt.Fprintf(w, "RA:%s", r.RemoteAddr)
  1292  	}), func(ts *httptest.Server) {
  1293  		ts.Listener = &blockingRemoteAddrListener{
  1294  			Listener: ts.Listener,
  1295  			conns:    conns,
  1296  		}
  1297  	}).ts
  1298  
  1299  	c := ts.Client()
  1300  	// Force separate connection for each:
  1301  	c.Transport.(*Transport).DisableKeepAlives = true
  1302  
  1303  	fetch := func(num int, response chan<- string) {
  1304  		resp, err := c.Get(ts.URL)
  1305  		if err != nil {
  1306  			t.Errorf("Request %d: %v", num, err)
  1307  			response <- ""
  1308  			return
  1309  		}
  1310  		defer resp.Body.Close()
  1311  		body, err := io.ReadAll(resp.Body)
  1312  		if err != nil {
  1313  			t.Errorf("Request %d: %v", num, err)
  1314  			response <- ""
  1315  			return
  1316  		}
  1317  		response <- string(body)
  1318  	}
  1319  
  1320  	// Start a request. The server will block on getting conn.RemoteAddr.
  1321  	response1c := make(chan string, 1)
  1322  	go fetch(1, response1c)
  1323  
  1324  	// Wait for the server to accept it; grab the connection.
  1325  	conn1 := <-conns
  1326  
  1327  	// Start another request and grab its connection
  1328  	response2c := make(chan string, 1)
  1329  	go fetch(2, response2c)
  1330  	conn2 := <-conns
  1331  
  1332  	// Send a response on connection 2.
  1333  	conn2.(*blockingRemoteAddrConn).addrs <- &net.TCPAddr{
  1334  		IP: net.ParseIP("12.12.12.12"), Port: 12}
  1335  
  1336  	// ... and see it
  1337  	response2 := <-response2c
  1338  	if g, e := response2, "RA:12.12.12.12:12"; g != e {
  1339  		t.Fatalf("response 2 addr = %q; want %q", g, e)
  1340  	}
  1341  
  1342  	// Finish the first response.
  1343  	conn1.(*blockingRemoteAddrConn).addrs <- &net.TCPAddr{
  1344  		IP: net.ParseIP("21.21.21.21"), Port: 21}
  1345  
  1346  	// ... and see it
  1347  	response1 := <-response1c
  1348  	if g, e := response1, "RA:21.21.21.21:21"; g != e {
  1349  		t.Fatalf("response 1 addr = %q; want %q", g, e)
  1350  	}
  1351  }
  1352  
  1353  // TestHeadResponses verifies that all MIME type sniffing and Content-Length
  1354  // counting of GET requests also happens on HEAD requests.
  1355  func TestHeadResponses(t *testing.T) { run(t, testHeadResponses) }
  1356  func testHeadResponses(t *testing.T, mode testMode) {
  1357  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1358  		_, err := w.Write([]byte("<html>"))
  1359  		if err != nil {
  1360  			t.Errorf("ResponseWriter.Write: %v", err)
  1361  		}
  1362  
  1363  		// Also exercise the ReaderFrom path
  1364  		_, err = io.Copy(w, strings.NewReader("789a"))
  1365  		if err != nil {
  1366  			t.Errorf("Copy(ResponseWriter, ...): %v", err)
  1367  		}
  1368  	}))
  1369  	res, err := cst.c.Head(cst.ts.URL)
  1370  	if err != nil {
  1371  		t.Error(err)
  1372  	}
  1373  	if len(res.TransferEncoding) > 0 {
  1374  		t.Errorf("expected no TransferEncoding; got %v", res.TransferEncoding)
  1375  	}
  1376  	if ct := res.Header.Get("Content-Type"); ct != "text/html; charset=utf-8" {
  1377  		t.Errorf("Content-Type: %q; want text/html; charset=utf-8", ct)
  1378  	}
  1379  	if v := res.ContentLength; v != 10 {
  1380  		t.Errorf("Content-Length: %d; want 10", v)
  1381  	}
  1382  	body, err := io.ReadAll(res.Body)
  1383  	if err != nil {
  1384  		t.Error(err)
  1385  	}
  1386  	if len(body) > 0 {
  1387  		t.Errorf("got unexpected body %q", string(body))
  1388  	}
  1389  }
  1390  
  1391  func TestTLSHandshakeTimeout(t *testing.T) {
  1392  	run(t, testTLSHandshakeTimeout, []testMode{https1Mode, http2Mode})
  1393  }
  1394  func testTLSHandshakeTimeout(t *testing.T, mode testMode) {
  1395  	errc := make(chanWriter, 10) // but only expecting 1
  1396  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {}),
  1397  		func(ts *httptest.Server) {
  1398  			ts.Config.ReadTimeout = 250 * time.Millisecond
  1399  			ts.Config.ErrorLog = log.New(errc, "", 0)
  1400  		},
  1401  	).ts
  1402  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1403  	if err != nil {
  1404  		t.Fatalf("Dial: %v", err)
  1405  	}
  1406  	defer conn.Close()
  1407  
  1408  	var buf [1]byte
  1409  	n, err := conn.Read(buf[:])
  1410  	if err == nil || n != 0 {
  1411  		t.Errorf("Read = %d, %v; want an error and no bytes", n, err)
  1412  	}
  1413  
  1414  	v := <-errc
  1415  	if !strings.Contains(v, "timeout") && !strings.Contains(v, "TLS handshake") {
  1416  		t.Errorf("expected a TLS handshake timeout error; got %q", v)
  1417  	}
  1418  }
  1419  
  1420  func TestTLSServer(t *testing.T) { run(t, testTLSServer, []testMode{https1Mode, http2Mode}) }
  1421  func testTLSServer(t *testing.T, mode testMode) {
  1422  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1423  		if r.TLS != nil {
  1424  			w.Header().Set("X-TLS-Set", "true")
  1425  			if r.TLS.HandshakeComplete {
  1426  				w.Header().Set("X-TLS-HandshakeComplete", "true")
  1427  			}
  1428  		}
  1429  	}), func(ts *httptest.Server) {
  1430  		ts.Config.ErrorLog = log.New(io.Discard, "", 0)
  1431  	}).ts
  1432  
  1433  	// Connect an idle TCP connection to this server before we run
  1434  	// our real tests. This idle connection used to block forever
  1435  	// in the TLS handshake, preventing future connections from
  1436  	// being accepted. It may prevent future accidental blocking
  1437  	// in newConn.
  1438  	idleConn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1439  	if err != nil {
  1440  		t.Fatalf("Dial: %v", err)
  1441  	}
  1442  	defer idleConn.Close()
  1443  
  1444  	if !strings.HasPrefix(ts.URL, "https://") {
  1445  		t.Errorf("expected test TLS server to start with https://, got %q", ts.URL)
  1446  		return
  1447  	}
  1448  	client := ts.Client()
  1449  	res, err := client.Get(ts.URL)
  1450  	if err != nil {
  1451  		t.Error(err)
  1452  		return
  1453  	}
  1454  	if res == nil {
  1455  		t.Errorf("got nil Response")
  1456  		return
  1457  	}
  1458  	defer res.Body.Close()
  1459  	if res.Header.Get("X-TLS-Set") != "true" {
  1460  		t.Errorf("expected X-TLS-Set response header")
  1461  		return
  1462  	}
  1463  	if res.Header.Get("X-TLS-HandshakeComplete") != "true" {
  1464  		t.Errorf("expected X-TLS-HandshakeComplete header")
  1465  	}
  1466  }
  1467  
  1468  func TestServeTLS(t *testing.T) {
  1469  	CondSkipHTTP2(t)
  1470  	// Not parallel: uses global test hooks.
  1471  	defer afterTest(t)
  1472  	defer SetTestHookServerServe(nil)
  1473  
  1474  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  1475  	if err != nil {
  1476  		t.Fatal(err)
  1477  	}
  1478  	tlsConf := &tls.Config{
  1479  		Certificates: []tls.Certificate{cert},
  1480  	}
  1481  
  1482  	ln := newLocalListener(t)
  1483  	defer ln.Close()
  1484  	addr := ln.Addr().String()
  1485  
  1486  	serving := make(chan bool, 1)
  1487  	SetTestHookServerServe(func(s *Server, ln net.Listener) {
  1488  		serving <- true
  1489  	})
  1490  	handler := HandlerFunc(func(w ResponseWriter, r *Request) {})
  1491  	s := &Server{
  1492  		Addr:      addr,
  1493  		TLSConfig: tlsConf,
  1494  		Handler:   handler,
  1495  	}
  1496  	errc := make(chan error, 1)
  1497  	go func() { errc <- s.ServeTLS(ln, "", "") }()
  1498  	select {
  1499  	case err := <-errc:
  1500  		t.Fatalf("ServeTLS: %v", err)
  1501  	case <-serving:
  1502  	}
  1503  
  1504  	c, err := tls.Dial("tcp", ln.Addr().String(), &tls.Config{
  1505  		InsecureSkipVerify: true,
  1506  		NextProtos:         []string{"h2", "http/1.1"},
  1507  	})
  1508  	if err != nil {
  1509  		t.Fatal(err)
  1510  	}
  1511  	defer c.Close()
  1512  	if got, want := c.ConnectionState().NegotiatedProtocol, "h2"; got != want {
  1513  		t.Errorf("NegotiatedProtocol = %q; want %q", got, want)
  1514  	}
  1515  	if got, want := c.ConnectionState().NegotiatedProtocolIsMutual, true; got != want {
  1516  		t.Errorf("NegotiatedProtocolIsMutual = %v; want %v", got, want)
  1517  	}
  1518  }
  1519  
  1520  // Test that the HTTPS server nicely rejects plaintext HTTP/1.x requests.
  1521  func TestTLSServerRejectHTTPRequests(t *testing.T) {
  1522  	run(t, testTLSServerRejectHTTPRequests, []testMode{https1Mode, http2Mode})
  1523  }
  1524  func testTLSServerRejectHTTPRequests(t *testing.T, mode testMode) {
  1525  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1526  		t.Error("unexpected HTTPS request")
  1527  	}), func(ts *httptest.Server) {
  1528  		var errBuf bytes.Buffer
  1529  		ts.Config.ErrorLog = log.New(&errBuf, "", 0)
  1530  	}).ts
  1531  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1532  	if err != nil {
  1533  		t.Fatal(err)
  1534  	}
  1535  	defer conn.Close()
  1536  	io.WriteString(conn, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n")
  1537  	slurp, err := io.ReadAll(conn)
  1538  	if err != nil {
  1539  		t.Fatal(err)
  1540  	}
  1541  	const wantPrefix = "HTTP/1.0 400 Bad Request\r\n"
  1542  	if !strings.HasPrefix(string(slurp), wantPrefix) {
  1543  		t.Errorf("response = %q; wanted prefix %q", slurp, wantPrefix)
  1544  	}
  1545  }
  1546  
  1547  // Issue 15908
  1548  func TestAutomaticHTTP2_Serve_NoTLSConfig(t *testing.T) {
  1549  	testAutomaticHTTP2_Serve(t, nil, true)
  1550  }
  1551  
  1552  func TestAutomaticHTTP2_Serve_NonH2TLSConfig(t *testing.T) {
  1553  	testAutomaticHTTP2_Serve(t, &tls.Config{}, false)
  1554  }
  1555  
  1556  func TestAutomaticHTTP2_Serve_H2TLSConfig(t *testing.T) {
  1557  	testAutomaticHTTP2_Serve(t, &tls.Config{NextProtos: []string{"h2"}}, true)
  1558  }
  1559  
  1560  func testAutomaticHTTP2_Serve(t *testing.T, tlsConf *tls.Config, wantH2 bool) {
  1561  	setParallel(t)
  1562  	defer afterTest(t)
  1563  	ln := newLocalListener(t)
  1564  	ln.Close() // immediately (not a defer!)
  1565  	var s Server
  1566  	s.TLSConfig = tlsConf
  1567  	if err := s.Serve(ln); err == nil {
  1568  		t.Fatal("expected an error")
  1569  	}
  1570  	gotH2 := s.TLSNextProto["h2"] != nil
  1571  	if gotH2 != wantH2 {
  1572  		t.Errorf("http2 configured = %v; want %v", gotH2, wantH2)
  1573  	}
  1574  }
  1575  
  1576  func TestAutomaticHTTP2_Serve_WithTLSConfig(t *testing.T) {
  1577  	setParallel(t)
  1578  	defer afterTest(t)
  1579  	ln := newLocalListener(t)
  1580  	ln.Close() // immediately (not a defer!)
  1581  	var s Server
  1582  	// Set the TLSConfig. In reality, this would be the
  1583  	// *tls.Config given to tls.NewListener.
  1584  	s.TLSConfig = &tls.Config{
  1585  		NextProtos: []string{"h2"},
  1586  	}
  1587  	if err := s.Serve(ln); err == nil {
  1588  		t.Fatal("expected an error")
  1589  	}
  1590  	on := s.TLSNextProto["h2"] != nil
  1591  	if !on {
  1592  		t.Errorf("http2 wasn't automatically enabled")
  1593  	}
  1594  }
  1595  
  1596  func TestAutomaticHTTP2_ListenAndServe(t *testing.T) {
  1597  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  1598  	if err != nil {
  1599  		t.Fatal(err)
  1600  	}
  1601  	testAutomaticHTTP2_ListenAndServe(t, &tls.Config{
  1602  		Certificates: []tls.Certificate{cert},
  1603  	})
  1604  }
  1605  
  1606  func TestAutomaticHTTP2_ListenAndServe_GetCertificate(t *testing.T) {
  1607  	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
  1608  	if err != nil {
  1609  		t.Fatal(err)
  1610  	}
  1611  	testAutomaticHTTP2_ListenAndServe(t, &tls.Config{
  1612  		GetCertificate: func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
  1613  			return &cert, nil
  1614  		},
  1615  	})
  1616  }
  1617  
  1618  func testAutomaticHTTP2_ListenAndServe(t *testing.T, tlsConf *tls.Config) {
  1619  	CondSkipHTTP2(t)
  1620  	// Not parallel: uses global test hooks.
  1621  	defer afterTest(t)
  1622  	defer SetTestHookServerServe(nil)
  1623  	var ok bool
  1624  	var s *Server
  1625  	const maxTries = 5
  1626  	var ln net.Listener
  1627  Try:
  1628  	for try := 0; try < maxTries; try++ {
  1629  		ln = newLocalListener(t)
  1630  		addr := ln.Addr().String()
  1631  		ln.Close()
  1632  		t.Logf("Got %v", addr)
  1633  		lnc := make(chan net.Listener, 1)
  1634  		SetTestHookServerServe(func(s *Server, ln net.Listener) {
  1635  			lnc <- ln
  1636  		})
  1637  		s = &Server{
  1638  			Addr:      addr,
  1639  			TLSConfig: tlsConf,
  1640  		}
  1641  		errc := make(chan error, 1)
  1642  		go func() { errc <- s.ListenAndServeTLS("", "") }()
  1643  		select {
  1644  		case err := <-errc:
  1645  			t.Logf("On try #%v: %v", try+1, err)
  1646  			continue
  1647  		case ln = <-lnc:
  1648  			ok = true
  1649  			t.Logf("Listening on %v", ln.Addr().String())
  1650  			break Try
  1651  		}
  1652  	}
  1653  	if !ok {
  1654  		t.Fatalf("Failed to start up after %d tries", maxTries)
  1655  	}
  1656  	defer ln.Close()
  1657  	c, err := tls.Dial("tcp", ln.Addr().String(), &tls.Config{
  1658  		InsecureSkipVerify: true,
  1659  		NextProtos:         []string{"h2", "http/1.1"},
  1660  	})
  1661  	if err != nil {
  1662  		t.Fatal(err)
  1663  	}
  1664  	defer c.Close()
  1665  	if got, want := c.ConnectionState().NegotiatedProtocol, "h2"; got != want {
  1666  		t.Errorf("NegotiatedProtocol = %q; want %q", got, want)
  1667  	}
  1668  	if got, want := c.ConnectionState().NegotiatedProtocolIsMutual, true; got != want {
  1669  		t.Errorf("NegotiatedProtocolIsMutual = %v; want %v", got, want)
  1670  	}
  1671  }
  1672  
  1673  type serverExpectTest struct {
  1674  	contentLength    int // of request body
  1675  	chunked          bool
  1676  	expectation      string // e.g. "100-continue"
  1677  	readBody         bool   // whether handler should read the body (if false, sends StatusUnauthorized)
  1678  	expectedResponse string // expected substring in first line of http response
  1679  }
  1680  
  1681  func expectTest(contentLength int, expectation string, readBody bool, expectedResponse string) serverExpectTest {
  1682  	return serverExpectTest{
  1683  		contentLength:    contentLength,
  1684  		expectation:      expectation,
  1685  		readBody:         readBody,
  1686  		expectedResponse: expectedResponse,
  1687  	}
  1688  }
  1689  
  1690  var serverExpectTests = []serverExpectTest{
  1691  	// Normal 100-continues, case-insensitive.
  1692  	expectTest(100, "100-continue", true, "100 Continue"),
  1693  	expectTest(100, "100-cOntInUE", true, "100 Continue"),
  1694  
  1695  	// No 100-continue.
  1696  	expectTest(100, "", true, "200 OK"),
  1697  
  1698  	// 100-continue but requesting client to deny us,
  1699  	// so it never reads the body.
  1700  	expectTest(100, "100-continue", false, "401 Unauthorized"),
  1701  	// Likewise without 100-continue:
  1702  	expectTest(100, "", false, "401 Unauthorized"),
  1703  
  1704  	// Non-standard expectations are failures
  1705  	expectTest(0, "a-pony", false, "417 Expectation Failed"),
  1706  
  1707  	// Expect-100 requested but no body (is apparently okay: Issue 7625)
  1708  	expectTest(0, "100-continue", true, "200 OK"),
  1709  	// Expect-100 requested but handler doesn't read the body
  1710  	expectTest(0, "100-continue", false, "401 Unauthorized"),
  1711  	// Expect-100 continue with no body, but a chunked body.
  1712  	{
  1713  		expectation:      "100-continue",
  1714  		readBody:         true,
  1715  		chunked:          true,
  1716  		expectedResponse: "100 Continue",
  1717  	},
  1718  }
  1719  
  1720  // Tests that the server responds to the "Expect" request header
  1721  // correctly.
  1722  func TestServerExpect(t *testing.T) { run(t, testServerExpect, []testMode{http1Mode}) }
  1723  func testServerExpect(t *testing.T, mode testMode) {
  1724  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  1725  		// Note using r.FormValue("readbody") because for POST
  1726  		// requests that would read from r.Body, which we only
  1727  		// conditionally want to do.
  1728  		if strings.Contains(r.URL.RawQuery, "readbody=true") {
  1729  			io.ReadAll(r.Body)
  1730  			w.Write([]byte("Hi"))
  1731  		} else {
  1732  			w.WriteHeader(StatusUnauthorized)
  1733  		}
  1734  	})).ts
  1735  
  1736  	runTest := func(test serverExpectTest) {
  1737  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  1738  		if err != nil {
  1739  			t.Fatalf("Dial: %v", err)
  1740  		}
  1741  		defer conn.Close()
  1742  
  1743  		// Only send the body immediately if we're acting like an HTTP client
  1744  		// that doesn't send 100-continue expectations.
  1745  		writeBody := test.contentLength != 0 && strings.ToLower(test.expectation) != "100-continue"
  1746  
  1747  		wg := sync.WaitGroup{}
  1748  		wg.Add(1)
  1749  		defer wg.Wait()
  1750  
  1751  		go func() {
  1752  			defer wg.Done()
  1753  
  1754  			contentLen := fmt.Sprintf("Content-Length: %d", test.contentLength)
  1755  			if test.chunked {
  1756  				contentLen = "Transfer-Encoding: chunked"
  1757  			}
  1758  			_, err := fmt.Fprintf(conn, "POST /?readbody=%v HTTP/1.1\r\n"+
  1759  				"Connection: close\r\n"+
  1760  				"%s\r\n"+
  1761  				"Expect: %s\r\nHost: foo\r\n\r\n",
  1762  				test.readBody, contentLen, test.expectation)
  1763  			if err != nil {
  1764  				t.Errorf("On test %#v, error writing request headers: %v", test, err)
  1765  				return
  1766  			}
  1767  			if writeBody {
  1768  				var targ io.WriteCloser = struct {
  1769  					io.Writer
  1770  					io.Closer
  1771  				}{
  1772  					conn,
  1773  					io.NopCloser(nil),
  1774  				}
  1775  				if test.chunked {
  1776  					targ = httputil.NewChunkedWriter(conn)
  1777  				}
  1778  				body := strings.Repeat("A", test.contentLength)
  1779  				_, err = fmt.Fprint(targ, body)
  1780  				if err == nil {
  1781  					err = targ.Close()
  1782  				}
  1783  				if err != nil {
  1784  					if !test.readBody {
  1785  						// Server likely already hung up on us.
  1786  						// See larger comment below.
  1787  						t.Logf("On test %#v, acceptable error writing request body: %v", test, err)
  1788  						return
  1789  					}
  1790  					t.Errorf("On test %#v, error writing request body: %v", test, err)
  1791  				}
  1792  			}
  1793  		}()
  1794  		bufr := bufio.NewReader(conn)
  1795  		line, err := bufr.ReadString('\n')
  1796  		if err != nil {
  1797  			if writeBody && !test.readBody {
  1798  				// This is an acceptable failure due to a possible TCP race:
  1799  				// We were still writing data and the server hung up on us. A TCP
  1800  				// implementation may send a RST if our request body data was known
  1801  				// to be lost, which may trigger our reads to fail.
  1802  				// See RFC 1122 page 88.
  1803  				t.Logf("On test %#v, acceptable error from ReadString: %v", test, err)
  1804  				return
  1805  			}
  1806  			t.Fatalf("On test %#v, ReadString: %v", test, err)
  1807  		}
  1808  		if !strings.Contains(line, test.expectedResponse) {
  1809  			t.Errorf("On test %#v, got first line = %q; want %q", test, line, test.expectedResponse)
  1810  		}
  1811  	}
  1812  
  1813  	for _, test := range serverExpectTests {
  1814  		runTest(test)
  1815  	}
  1816  }
  1817  
  1818  // Under a ~256KB (maxPostHandlerReadBytes) threshold, the server
  1819  // should consume client request bodies that a handler didn't read.
  1820  func TestServerUnreadRequestBodyLittle(t *testing.T) {
  1821  	setParallel(t)
  1822  	defer afterTest(t)
  1823  	conn := new(testConn)
  1824  	body := strings.Repeat("x", 100<<10)
  1825  	conn.readBuf.Write([]byte(fmt.Sprintf(
  1826  		"POST / HTTP/1.1\r\n"+
  1827  			"Host: test\r\n"+
  1828  			"Content-Length: %d\r\n"+
  1829  			"\r\n", len(body))))
  1830  	conn.readBuf.Write([]byte(body))
  1831  
  1832  	done := make(chan bool)
  1833  
  1834  	readBufLen := func() int {
  1835  		conn.readMu.Lock()
  1836  		defer conn.readMu.Unlock()
  1837  		return conn.readBuf.Len()
  1838  	}
  1839  
  1840  	ls := &oneConnListener{conn}
  1841  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  1842  		defer close(done)
  1843  		if bufLen := readBufLen(); bufLen < len(body)/2 {
  1844  			t.Errorf("on request, read buffer length is %d; expected about 100 KB", bufLen)
  1845  		}
  1846  		rw.WriteHeader(200)
  1847  		rw.(Flusher).Flush()
  1848  		if g, e := readBufLen(), 0; g != e {
  1849  			t.Errorf("after WriteHeader, read buffer length is %d; want %d", g, e)
  1850  		}
  1851  		if c := rw.Header().Get("Connection"); c != "" {
  1852  			t.Errorf(`Connection header = %q; want ""`, c)
  1853  		}
  1854  	}))
  1855  	<-done
  1856  }
  1857  
  1858  // Over a ~256KB (maxPostHandlerReadBytes) threshold, the server
  1859  // should ignore client request bodies that a handler didn't read
  1860  // and close the connection.
  1861  func TestServerUnreadRequestBodyLarge(t *testing.T) {
  1862  	setParallel(t)
  1863  	if testing.Short() && testenv.Builder() == "" {
  1864  		t.Log("skipping in short mode")
  1865  	}
  1866  	conn := new(testConn)
  1867  	body := strings.Repeat("x", 1<<20)
  1868  	conn.readBuf.Write([]byte(fmt.Sprintf(
  1869  		"POST / HTTP/1.1\r\n"+
  1870  			"Host: test\r\n"+
  1871  			"Content-Length: %d\r\n"+
  1872  			"\r\n", len(body))))
  1873  	conn.readBuf.Write([]byte(body))
  1874  	conn.closec = make(chan bool, 1)
  1875  
  1876  	ls := &oneConnListener{conn}
  1877  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  1878  		if conn.readBuf.Len() < len(body)/2 {
  1879  			t.Errorf("on request, read buffer length is %d; expected about 1MB", conn.readBuf.Len())
  1880  		}
  1881  		rw.WriteHeader(200)
  1882  		rw.(Flusher).Flush()
  1883  		if conn.readBuf.Len() < len(body)/2 {
  1884  			t.Errorf("post-WriteHeader, read buffer length is %d; expected about 1MB", conn.readBuf.Len())
  1885  		}
  1886  	}))
  1887  	<-conn.closec
  1888  
  1889  	if res := conn.writeBuf.String(); !strings.Contains(res, "Connection: close") {
  1890  		t.Errorf("Expected a Connection: close header; got response: %s", res)
  1891  	}
  1892  }
  1893  
  1894  type handlerBodyCloseTest struct {
  1895  	bodySize     int
  1896  	bodyChunked  bool
  1897  	reqConnClose bool
  1898  
  1899  	wantEOFSearch bool // should Handler's Body.Close do Reads, looking for EOF?
  1900  	wantNextReq   bool // should it find the next request on the same conn?
  1901  }
  1902  
  1903  func (t handlerBodyCloseTest) connectionHeader() string {
  1904  	if t.reqConnClose {
  1905  		return "Connection: close\r\n"
  1906  	}
  1907  	return ""
  1908  }
  1909  
  1910  var handlerBodyCloseTests = [...]handlerBodyCloseTest{
  1911  	// Small enough to slurp past to the next request +
  1912  	// has Content-Length.
  1913  	0: {
  1914  		bodySize:      20 << 10,
  1915  		bodyChunked:   false,
  1916  		reqConnClose:  false,
  1917  		wantEOFSearch: true,
  1918  		wantNextReq:   true,
  1919  	},
  1920  
  1921  	// Small enough to slurp past to the next request +
  1922  	// is chunked.
  1923  	1: {
  1924  		bodySize:      20 << 10,
  1925  		bodyChunked:   true,
  1926  		reqConnClose:  false,
  1927  		wantEOFSearch: true,
  1928  		wantNextReq:   true,
  1929  	},
  1930  
  1931  	// Small enough to slurp past to the next request +
  1932  	// has Content-Length +
  1933  	// declares Connection: close (so pointless to read more).
  1934  	2: {
  1935  		bodySize:      20 << 10,
  1936  		bodyChunked:   false,
  1937  		reqConnClose:  true,
  1938  		wantEOFSearch: false,
  1939  		wantNextReq:   false,
  1940  	},
  1941  
  1942  	// Small enough to slurp past to the next request +
  1943  	// declares Connection: close,
  1944  	// but chunked, so it might have trailers.
  1945  	// TODO: maybe skip this search if no trailers were declared
  1946  	// in the headers.
  1947  	3: {
  1948  		bodySize:      20 << 10,
  1949  		bodyChunked:   true,
  1950  		reqConnClose:  true,
  1951  		wantEOFSearch: true,
  1952  		wantNextReq:   false,
  1953  	},
  1954  
  1955  	// Big with Content-Length, so give up immediately if we know it's too big.
  1956  	4: {
  1957  		bodySize:      1 << 20,
  1958  		bodyChunked:   false, // has a Content-Length
  1959  		reqConnClose:  false,
  1960  		wantEOFSearch: false,
  1961  		wantNextReq:   false,
  1962  	},
  1963  
  1964  	// Big chunked, so read a bit before giving up.
  1965  	5: {
  1966  		bodySize:      1 << 20,
  1967  		bodyChunked:   true,
  1968  		reqConnClose:  false,
  1969  		wantEOFSearch: true,
  1970  		wantNextReq:   false,
  1971  	},
  1972  
  1973  	// Big with Connection: close, but chunked, so search for trailers.
  1974  	// TODO: maybe skip this search if no trailers were declared
  1975  	// in the headers.
  1976  	6: {
  1977  		bodySize:      1 << 20,
  1978  		bodyChunked:   true,
  1979  		reqConnClose:  true,
  1980  		wantEOFSearch: true,
  1981  		wantNextReq:   false,
  1982  	},
  1983  
  1984  	// Big with Connection: close, so don't do any reads on Close.
  1985  	// With Content-Length.
  1986  	7: {
  1987  		bodySize:      1 << 20,
  1988  		bodyChunked:   false,
  1989  		reqConnClose:  true,
  1990  		wantEOFSearch: false,
  1991  		wantNextReq:   false,
  1992  	},
  1993  }
  1994  
  1995  func TestHandlerBodyClose(t *testing.T) {
  1996  	setParallel(t)
  1997  	if testing.Short() && testenv.Builder() == "" {
  1998  		t.Skip("skipping in -short mode")
  1999  	}
  2000  	for i, tt := range handlerBodyCloseTests {
  2001  		testHandlerBodyClose(t, i, tt)
  2002  	}
  2003  }
  2004  
  2005  func testHandlerBodyClose(t *testing.T, i int, tt handlerBodyCloseTest) {
  2006  	conn := new(testConn)
  2007  	body := strings.Repeat("x", tt.bodySize)
  2008  	if tt.bodyChunked {
  2009  		conn.readBuf.WriteString("POST / HTTP/1.1\r\n" +
  2010  			"Host: test\r\n" +
  2011  			tt.connectionHeader() +
  2012  			"Transfer-Encoding: chunked\r\n" +
  2013  			"\r\n")
  2014  		cw := internal.NewChunkedWriter(&conn.readBuf)
  2015  		io.WriteString(cw, body)
  2016  		cw.Close()
  2017  		conn.readBuf.WriteString("\r\n")
  2018  	} else {
  2019  		conn.readBuf.Write([]byte(fmt.Sprintf(
  2020  			"POST / HTTP/1.1\r\n"+
  2021  				"Host: test\r\n"+
  2022  				tt.connectionHeader()+
  2023  				"Content-Length: %d\r\n"+
  2024  				"\r\n", len(body))))
  2025  		conn.readBuf.Write([]byte(body))
  2026  	}
  2027  	if !tt.reqConnClose {
  2028  		conn.readBuf.WriteString("GET / HTTP/1.1\r\nHost: test\r\n\r\n")
  2029  	}
  2030  	conn.closec = make(chan bool, 1)
  2031  
  2032  	readBufLen := func() int {
  2033  		conn.readMu.Lock()
  2034  		defer conn.readMu.Unlock()
  2035  		return conn.readBuf.Len()
  2036  	}
  2037  
  2038  	ls := &oneConnListener{conn}
  2039  	var numReqs int
  2040  	var size0, size1 int
  2041  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  2042  		numReqs++
  2043  		if numReqs == 1 {
  2044  			size0 = readBufLen()
  2045  			req.Body.Close()
  2046  			size1 = readBufLen()
  2047  		}
  2048  	}))
  2049  	<-conn.closec
  2050  	if numReqs < 1 || numReqs > 2 {
  2051  		t.Fatalf("%d. bug in test. unexpected number of requests = %d", i, numReqs)
  2052  	}
  2053  	didSearch := size0 != size1
  2054  	if didSearch != tt.wantEOFSearch {
  2055  		t.Errorf("%d. did EOF search = %v; want %v (size went from %d to %d)", i, didSearch, !didSearch, size0, size1)
  2056  	}
  2057  	if tt.wantNextReq && numReqs != 2 {
  2058  		t.Errorf("%d. numReq = %d; want 2", i, numReqs)
  2059  	}
  2060  }
  2061  
  2062  // testHandlerBodyConsumer represents a function injected into a test handler to
  2063  // vary work done on a request Body.
  2064  type testHandlerBodyConsumer struct {
  2065  	name string
  2066  	f    func(io.ReadCloser)
  2067  }
  2068  
  2069  var testHandlerBodyConsumers = []testHandlerBodyConsumer{
  2070  	{"nil", func(io.ReadCloser) {}},
  2071  	{"close", func(r io.ReadCloser) { r.Close() }},
  2072  	{"discard", func(r io.ReadCloser) { io.Copy(io.Discard, r) }},
  2073  }
  2074  
  2075  func TestRequestBodyReadErrorClosesConnection(t *testing.T) {
  2076  	setParallel(t)
  2077  	defer afterTest(t)
  2078  	for _, handler := range testHandlerBodyConsumers {
  2079  		conn := new(testConn)
  2080  		conn.readBuf.WriteString("POST /public HTTP/1.1\r\n" +
  2081  			"Host: test\r\n" +
  2082  			"Transfer-Encoding: chunked\r\n" +
  2083  			"\r\n" +
  2084  			"hax\r\n" + // Invalid chunked encoding
  2085  			"GET /secret HTTP/1.1\r\n" +
  2086  			"Host: test\r\n" +
  2087  			"\r\n")
  2088  
  2089  		conn.closec = make(chan bool, 1)
  2090  		ls := &oneConnListener{conn}
  2091  		var numReqs int
  2092  		go Serve(ls, HandlerFunc(func(_ ResponseWriter, req *Request) {
  2093  			numReqs++
  2094  			if strings.Contains(req.URL.Path, "secret") {
  2095  				t.Error("Request for /secret encountered, should not have happened.")
  2096  			}
  2097  			handler.f(req.Body)
  2098  		}))
  2099  		<-conn.closec
  2100  		if numReqs != 1 {
  2101  			t.Errorf("Handler %v: got %d reqs; want 1", handler.name, numReqs)
  2102  		}
  2103  	}
  2104  }
  2105  
  2106  func TestInvalidTrailerClosesConnection(t *testing.T) {
  2107  	setParallel(t)
  2108  	defer afterTest(t)
  2109  	for _, handler := range testHandlerBodyConsumers {
  2110  		conn := new(testConn)
  2111  		conn.readBuf.WriteString("POST /public HTTP/1.1\r\n" +
  2112  			"Host: test\r\n" +
  2113  			"Trailer: hack\r\n" +
  2114  			"Transfer-Encoding: chunked\r\n" +
  2115  			"\r\n" +
  2116  			"3\r\n" +
  2117  			"hax\r\n" +
  2118  			"0\r\n" +
  2119  			"I'm not a valid trailer\r\n" +
  2120  			"GET /secret HTTP/1.1\r\n" +
  2121  			"Host: test\r\n" +
  2122  			"\r\n")
  2123  
  2124  		conn.closec = make(chan bool, 1)
  2125  		ln := &oneConnListener{conn}
  2126  		var numReqs int
  2127  		go Serve(ln, HandlerFunc(func(_ ResponseWriter, req *Request) {
  2128  			numReqs++
  2129  			if strings.Contains(req.URL.Path, "secret") {
  2130  				t.Errorf("Handler %s, Request for /secret encountered, should not have happened.", handler.name)
  2131  			}
  2132  			handler.f(req.Body)
  2133  		}))
  2134  		<-conn.closec
  2135  		if numReqs != 1 {
  2136  			t.Errorf("Handler %s: got %d reqs; want 1", handler.name, numReqs)
  2137  		}
  2138  	}
  2139  }
  2140  
  2141  // slowTestConn is a net.Conn that provides a means to simulate parts of a
  2142  // request being received piecemeal. Deadlines can be set and enforced in both
  2143  // Read and Write.
  2144  type slowTestConn struct {
  2145  	// over multiple calls to Read, time.Durations are slept, strings are read.
  2146  	script []any
  2147  	closec chan bool
  2148  
  2149  	mu     sync.Mutex // guards rd/wd
  2150  	rd, wd time.Time  // read, write deadline
  2151  	noopConn
  2152  }
  2153  
  2154  func (c *slowTestConn) SetDeadline(t time.Time) error {
  2155  	c.SetReadDeadline(t)
  2156  	c.SetWriteDeadline(t)
  2157  	return nil
  2158  }
  2159  
  2160  func (c *slowTestConn) SetReadDeadline(t time.Time) error {
  2161  	c.mu.Lock()
  2162  	defer c.mu.Unlock()
  2163  	c.rd = t
  2164  	return nil
  2165  }
  2166  
  2167  func (c *slowTestConn) SetWriteDeadline(t time.Time) error {
  2168  	c.mu.Lock()
  2169  	defer c.mu.Unlock()
  2170  	c.wd = t
  2171  	return nil
  2172  }
  2173  
  2174  func (c *slowTestConn) Read(b []byte) (n int, err error) {
  2175  	c.mu.Lock()
  2176  	defer c.mu.Unlock()
  2177  restart:
  2178  	if !c.rd.IsZero() && time.Now().After(c.rd) {
  2179  		return 0, syscall.ETIMEDOUT
  2180  	}
  2181  	if len(c.script) == 0 {
  2182  		return 0, io.EOF
  2183  	}
  2184  
  2185  	switch cue := c.script[0].(type) {
  2186  	case time.Duration:
  2187  		if !c.rd.IsZero() {
  2188  			// If the deadline falls in the middle of our sleep window, deduct
  2189  			// part of the sleep, then return a timeout.
  2190  			if remaining := time.Until(c.rd); remaining < cue {
  2191  				c.script[0] = cue - remaining
  2192  				time.Sleep(remaining)
  2193  				return 0, syscall.ETIMEDOUT
  2194  			}
  2195  		}
  2196  		c.script = c.script[1:]
  2197  		time.Sleep(cue)
  2198  		goto restart
  2199  
  2200  	case string:
  2201  		n = copy(b, cue)
  2202  		// If cue is too big for the buffer, leave the end for the next Read.
  2203  		if len(cue) > n {
  2204  			c.script[0] = cue[n:]
  2205  		} else {
  2206  			c.script = c.script[1:]
  2207  		}
  2208  
  2209  	default:
  2210  		panic("unknown cue in slowTestConn script")
  2211  	}
  2212  
  2213  	return
  2214  }
  2215  
  2216  func (c *slowTestConn) Close() error {
  2217  	select {
  2218  	case c.closec <- true:
  2219  	default:
  2220  	}
  2221  	return nil
  2222  }
  2223  
  2224  func (c *slowTestConn) Write(b []byte) (int, error) {
  2225  	if !c.wd.IsZero() && time.Now().After(c.wd) {
  2226  		return 0, syscall.ETIMEDOUT
  2227  	}
  2228  	return len(b), nil
  2229  }
  2230  
  2231  func TestRequestBodyTimeoutClosesConnection(t *testing.T) {
  2232  	if testing.Short() {
  2233  		t.Skip("skipping in -short mode")
  2234  	}
  2235  	defer afterTest(t)
  2236  	for _, handler := range testHandlerBodyConsumers {
  2237  		conn := &slowTestConn{
  2238  			script: []any{
  2239  				"POST /public HTTP/1.1\r\n" +
  2240  					"Host: test\r\n" +
  2241  					"Content-Length: 10000\r\n" +
  2242  					"\r\n",
  2243  				"foo bar baz",
  2244  				600 * time.Millisecond, // Request deadline should hit here
  2245  				"GET /secret HTTP/1.1\r\n" +
  2246  					"Host: test\r\n" +
  2247  					"\r\n",
  2248  			},
  2249  			closec: make(chan bool, 1),
  2250  		}
  2251  		ls := &oneConnListener{conn}
  2252  
  2253  		var numReqs int
  2254  		s := Server{
  2255  			Handler: HandlerFunc(func(_ ResponseWriter, req *Request) {
  2256  				numReqs++
  2257  				if strings.Contains(req.URL.Path, "secret") {
  2258  					t.Error("Request for /secret encountered, should not have happened.")
  2259  				}
  2260  				handler.f(req.Body)
  2261  			}),
  2262  			ReadTimeout: 400 * time.Millisecond,
  2263  		}
  2264  		go s.Serve(ls)
  2265  		<-conn.closec
  2266  
  2267  		if numReqs != 1 {
  2268  			t.Errorf("Handler %v: got %d reqs; want 1", handler.name, numReqs)
  2269  		}
  2270  	}
  2271  }
  2272  
  2273  // cancelableTimeoutContext overwrites the error message to DeadlineExceeded
  2274  type cancelableTimeoutContext struct {
  2275  	context.Context
  2276  }
  2277  
  2278  func (c cancelableTimeoutContext) Err() error {
  2279  	if c.Context.Err() != nil {
  2280  		return context.DeadlineExceeded
  2281  	}
  2282  	return nil
  2283  }
  2284  
  2285  func TestTimeoutHandler(t *testing.T) { run(t, testTimeoutHandler) }
  2286  func testTimeoutHandler(t *testing.T, mode testMode) {
  2287  	sendHi := make(chan bool, 1)
  2288  	writeErrors := make(chan error, 1)
  2289  	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2290  		<-sendHi
  2291  		_, werr := w.Write([]byte("hi"))
  2292  		writeErrors <- werr
  2293  	})
  2294  	ctx, cancel := context.WithCancel(context.Background())
  2295  	h := NewTestTimeoutHandler(sayHi, cancelableTimeoutContext{ctx})
  2296  	cst := newClientServerTest(t, mode, h)
  2297  
  2298  	// Succeed without timing out:
  2299  	sendHi <- true
  2300  	res, err := cst.c.Get(cst.ts.URL)
  2301  	if err != nil {
  2302  		t.Error(err)
  2303  	}
  2304  	if g, e := res.StatusCode, StatusOK; g != e {
  2305  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2306  	}
  2307  	body, _ := io.ReadAll(res.Body)
  2308  	if g, e := string(body), "hi"; g != e {
  2309  		t.Errorf("got body %q; expected %q", g, e)
  2310  	}
  2311  	if g := <-writeErrors; g != nil {
  2312  		t.Errorf("got unexpected Write error on first request: %v", g)
  2313  	}
  2314  
  2315  	// Times out:
  2316  	cancel()
  2317  
  2318  	res, err = cst.c.Get(cst.ts.URL)
  2319  	if err != nil {
  2320  		t.Error(err)
  2321  	}
  2322  	if g, e := res.StatusCode, StatusServiceUnavailable; g != e {
  2323  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2324  	}
  2325  	body, _ = io.ReadAll(res.Body)
  2326  	if !strings.Contains(string(body), "<title>Timeout</title>") {
  2327  		t.Errorf("expected timeout body; got %q", string(body))
  2328  	}
  2329  	if g, w := res.Header.Get("Content-Type"), "text/html; charset=utf-8"; g != w {
  2330  		t.Errorf("response content-type = %q; want %q", g, w)
  2331  	}
  2332  
  2333  	// Now make the previously-timed out handler speak again,
  2334  	// which verifies the panic is handled:
  2335  	sendHi <- true
  2336  	if g, e := <-writeErrors, ErrHandlerTimeout; g != e {
  2337  		t.Errorf("expected Write error of %v; got %v", e, g)
  2338  	}
  2339  }
  2340  
  2341  // See issues 8209 and 8414.
  2342  func TestTimeoutHandlerRace(t *testing.T) { run(t, testTimeoutHandlerRace) }
  2343  func testTimeoutHandlerRace(t *testing.T, mode testMode) {
  2344  	delayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2345  		ms, _ := strconv.Atoi(r.URL.Path[1:])
  2346  		if ms == 0 {
  2347  			ms = 1
  2348  		}
  2349  		for i := 0; i < ms; i++ {
  2350  			w.Write([]byte("hi"))
  2351  			time.Sleep(time.Millisecond)
  2352  		}
  2353  	})
  2354  
  2355  	ts := newClientServerTest(t, mode, TimeoutHandler(delayHi, 20*time.Millisecond, "")).ts
  2356  
  2357  	c := ts.Client()
  2358  
  2359  	var wg sync.WaitGroup
  2360  	gate := make(chan bool, 10)
  2361  	n := 50
  2362  	if testing.Short() {
  2363  		n = 10
  2364  		gate = make(chan bool, 3)
  2365  	}
  2366  	for i := 0; i < n; i++ {
  2367  		gate <- true
  2368  		wg.Add(1)
  2369  		go func() {
  2370  			defer wg.Done()
  2371  			defer func() { <-gate }()
  2372  			res, err := c.Get(fmt.Sprintf("%s/%d", ts.URL, rand.Intn(50)))
  2373  			if err == nil {
  2374  				io.Copy(io.Discard, res.Body)
  2375  				res.Body.Close()
  2376  			}
  2377  		}()
  2378  	}
  2379  	wg.Wait()
  2380  }
  2381  
  2382  // See issues 8209 and 8414.
  2383  // Both issues involved panics in the implementation of TimeoutHandler.
  2384  func TestTimeoutHandlerRaceHeader(t *testing.T) { run(t, testTimeoutHandlerRaceHeader) }
  2385  func testTimeoutHandlerRaceHeader(t *testing.T, mode testMode) {
  2386  	delay204 := HandlerFunc(func(w ResponseWriter, r *Request) {
  2387  		w.WriteHeader(204)
  2388  	})
  2389  
  2390  	ts := newClientServerTest(t, mode, TimeoutHandler(delay204, time.Nanosecond, "")).ts
  2391  
  2392  	var wg sync.WaitGroup
  2393  	gate := make(chan bool, 50)
  2394  	n := 500
  2395  	if testing.Short() {
  2396  		n = 10
  2397  	}
  2398  
  2399  	c := ts.Client()
  2400  	for i := 0; i < n; i++ {
  2401  		gate <- true
  2402  		wg.Add(1)
  2403  		go func() {
  2404  			defer wg.Done()
  2405  			defer func() { <-gate }()
  2406  			res, err := c.Get(ts.URL)
  2407  			if err != nil {
  2408  				// We see ECONNRESET from the connection occasionally,
  2409  				// and that's OK: this test is checking that the server does not panic.
  2410  				t.Log(err)
  2411  				return
  2412  			}
  2413  			defer res.Body.Close()
  2414  			io.Copy(io.Discard, res.Body)
  2415  		}()
  2416  	}
  2417  	wg.Wait()
  2418  }
  2419  
  2420  // Issue 9162
  2421  func TestTimeoutHandlerRaceHeaderTimeout(t *testing.T) { run(t, testTimeoutHandlerRaceHeaderTimeout) }
  2422  func testTimeoutHandlerRaceHeaderTimeout(t *testing.T, mode testMode) {
  2423  	sendHi := make(chan bool, 1)
  2424  	writeErrors := make(chan error, 1)
  2425  	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2426  		w.Header().Set("Content-Type", "text/plain")
  2427  		<-sendHi
  2428  		_, werr := w.Write([]byte("hi"))
  2429  		writeErrors <- werr
  2430  	})
  2431  	ctx, cancel := context.WithCancel(context.Background())
  2432  	h := NewTestTimeoutHandler(sayHi, cancelableTimeoutContext{ctx})
  2433  	cst := newClientServerTest(t, mode, h)
  2434  
  2435  	// Succeed without timing out:
  2436  	sendHi <- true
  2437  	res, err := cst.c.Get(cst.ts.URL)
  2438  	if err != nil {
  2439  		t.Error(err)
  2440  	}
  2441  	if g, e := res.StatusCode, StatusOK; g != e {
  2442  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2443  	}
  2444  	body, _ := io.ReadAll(res.Body)
  2445  	if g, e := string(body), "hi"; g != e {
  2446  		t.Errorf("got body %q; expected %q", g, e)
  2447  	}
  2448  	if g := <-writeErrors; g != nil {
  2449  		t.Errorf("got unexpected Write error on first request: %v", g)
  2450  	}
  2451  
  2452  	// Times out:
  2453  	cancel()
  2454  
  2455  	res, err = cst.c.Get(cst.ts.URL)
  2456  	if err != nil {
  2457  		t.Error(err)
  2458  	}
  2459  	if g, e := res.StatusCode, StatusServiceUnavailable; g != e {
  2460  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2461  	}
  2462  	body, _ = io.ReadAll(res.Body)
  2463  	if !strings.Contains(string(body), "<title>Timeout</title>") {
  2464  		t.Errorf("expected timeout body; got %q", string(body))
  2465  	}
  2466  
  2467  	// Now make the previously-timed out handler speak again,
  2468  	// which verifies the panic is handled:
  2469  	sendHi <- true
  2470  	if g, e := <-writeErrors, ErrHandlerTimeout; g != e {
  2471  		t.Errorf("expected Write error of %v; got %v", e, g)
  2472  	}
  2473  }
  2474  
  2475  // Issue 14568.
  2476  func TestTimeoutHandlerStartTimerWhenServing(t *testing.T) {
  2477  	run(t, testTimeoutHandlerStartTimerWhenServing)
  2478  }
  2479  func testTimeoutHandlerStartTimerWhenServing(t *testing.T, mode testMode) {
  2480  	if testing.Short() {
  2481  		t.Skip("skipping sleeping test in -short mode")
  2482  	}
  2483  	var handler HandlerFunc = func(w ResponseWriter, _ *Request) {
  2484  		w.WriteHeader(StatusNoContent)
  2485  	}
  2486  	timeout := 300 * time.Millisecond
  2487  	ts := newClientServerTest(t, mode, TimeoutHandler(handler, timeout, "")).ts
  2488  	defer ts.Close()
  2489  
  2490  	c := ts.Client()
  2491  
  2492  	// Issue was caused by the timeout handler starting the timer when
  2493  	// was created, not when the request. So wait for more than the timeout
  2494  	// to ensure that's not the case.
  2495  	time.Sleep(2 * timeout)
  2496  	res, err := c.Get(ts.URL)
  2497  	if err != nil {
  2498  		t.Fatal(err)
  2499  	}
  2500  	defer res.Body.Close()
  2501  	if res.StatusCode != StatusNoContent {
  2502  		t.Errorf("got res.StatusCode %d, want %v", res.StatusCode, StatusNoContent)
  2503  	}
  2504  }
  2505  
  2506  func TestTimeoutHandlerContextCanceled(t *testing.T) { run(t, testTimeoutHandlerContextCanceled) }
  2507  func testTimeoutHandlerContextCanceled(t *testing.T, mode testMode) {
  2508  	writeErrors := make(chan error, 1)
  2509  	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
  2510  		w.Header().Set("Content-Type", "text/plain")
  2511  		var err error
  2512  		// The request context has already been canceled, but
  2513  		// retry the write for a while to give the timeout handler
  2514  		// a chance to notice.
  2515  		for i := 0; i < 100; i++ {
  2516  			_, err = w.Write([]byte("a"))
  2517  			if err != nil {
  2518  				break
  2519  			}
  2520  			time.Sleep(1 * time.Millisecond)
  2521  		}
  2522  		writeErrors <- err
  2523  	})
  2524  	ctx, cancel := context.WithCancel(context.Background())
  2525  	cancel()
  2526  	h := NewTestTimeoutHandler(sayHi, ctx)
  2527  	cst := newClientServerTest(t, mode, h)
  2528  	defer cst.close()
  2529  
  2530  	res, err := cst.c.Get(cst.ts.URL)
  2531  	if err != nil {
  2532  		t.Error(err)
  2533  	}
  2534  	if g, e := res.StatusCode, StatusServiceUnavailable; g != e {
  2535  		t.Errorf("got res.StatusCode %d; expected %d", g, e)
  2536  	}
  2537  	body, _ := io.ReadAll(res.Body)
  2538  	if g, e := string(body), ""; g != e {
  2539  		t.Errorf("got body %q; expected %q", g, e)
  2540  	}
  2541  	if g, e := <-writeErrors, context.Canceled; g != e {
  2542  		t.Errorf("got unexpected Write in handler: %v, want %g", g, e)
  2543  	}
  2544  }
  2545  
  2546  // https://golang.org/issue/15948
  2547  func TestTimeoutHandlerEmptyResponse(t *testing.T) { run(t, testTimeoutHandlerEmptyResponse) }
  2548  func testTimeoutHandlerEmptyResponse(t *testing.T, mode testMode) {
  2549  	var handler HandlerFunc = func(w ResponseWriter, _ *Request) {
  2550  		// No response.
  2551  	}
  2552  	timeout := 300 * time.Millisecond
  2553  	ts := newClientServerTest(t, mode, TimeoutHandler(handler, timeout, "")).ts
  2554  
  2555  	c := ts.Client()
  2556  
  2557  	res, err := c.Get(ts.URL)
  2558  	if err != nil {
  2559  		t.Fatal(err)
  2560  	}
  2561  	defer res.Body.Close()
  2562  	if res.StatusCode != StatusOK {
  2563  		t.Errorf("got res.StatusCode %d, want %v", res.StatusCode, StatusOK)
  2564  	}
  2565  }
  2566  
  2567  // https://golang.org/issues/22084
  2568  func TestTimeoutHandlerPanicRecovery(t *testing.T) {
  2569  	wrapper := func(h Handler) Handler {
  2570  		return TimeoutHandler(h, time.Second, "")
  2571  	}
  2572  	run(t, func(t *testing.T, mode testMode) {
  2573  		testHandlerPanic(t, false, mode, wrapper, "intentional death for testing")
  2574  	}, testNotParallel)
  2575  }
  2576  
  2577  func TestRedirectBadPath(t *testing.T) {
  2578  	// This used to crash. It's not valid input (bad path), but it
  2579  	// shouldn't crash.
  2580  	rr := httptest.NewRecorder()
  2581  	req := &Request{
  2582  		Method: "GET",
  2583  		URL: &url.URL{
  2584  			Scheme: "http",
  2585  			Path:   "not-empty-but-no-leading-slash", // bogus
  2586  		},
  2587  	}
  2588  	Redirect(rr, req, "", 304)
  2589  	if rr.Code != 304 {
  2590  		t.Errorf("Code = %d; want 304", rr.Code)
  2591  	}
  2592  }
  2593  
  2594  // Test different URL formats and schemes
  2595  func TestRedirect(t *testing.T) {
  2596  	req, _ := NewRequest("GET", "http://example.com/qux/", nil)
  2597  
  2598  	var tests = []struct {
  2599  		in   string
  2600  		want string
  2601  	}{
  2602  		// normal http
  2603  		{"http://foobar.com/baz", "http://foobar.com/baz"},
  2604  		// normal https
  2605  		{"https://foobar.com/baz", "https://foobar.com/baz"},
  2606  		// custom scheme
  2607  		{"test://foobar.com/baz", "test://foobar.com/baz"},
  2608  		// schemeless
  2609  		{"//foobar.com/baz", "//foobar.com/baz"},
  2610  		// relative to the root
  2611  		{"/foobar.com/baz", "/foobar.com/baz"},
  2612  		// relative to the current path
  2613  		{"foobar.com/baz", "/qux/foobar.com/baz"},
  2614  		// relative to the current path (+ going upwards)
  2615  		{"../quux/foobar.com/baz", "/quux/foobar.com/baz"},
  2616  		// incorrect number of slashes
  2617  		{"///foobar.com/baz", "/foobar.com/baz"},
  2618  
  2619  		// Verifies we don't path.Clean() on the wrong parts in redirects:
  2620  		{"/foo?next=http://bar.com/", "/foo?next=http://bar.com/"},
  2621  		{"http://localhost:8080/_ah/login?continue=http://localhost:8080/",
  2622  			"http://localhost:8080/_ah/login?continue=http://localhost:8080/"},
  2623  
  2624  		{"/фубар", "/%d1%84%d1%83%d0%b1%d0%b0%d1%80"},
  2625  		{"http://foo.com/фубар", "http://foo.com/%d1%84%d1%83%d0%b1%d0%b0%d1%80"},
  2626  	}
  2627  
  2628  	for _, tt := range tests {
  2629  		rec := httptest.NewRecorder()
  2630  		Redirect(rec, req, tt.in, 302)
  2631  		if got, want := rec.Code, 302; got != want {
  2632  			t.Errorf("Redirect(%q) generated status code %v; want %v", tt.in, got, want)
  2633  		}
  2634  		if got := rec.Header().Get("Location"); got != tt.want {
  2635  			t.Errorf("Redirect(%q) generated Location header %q; want %q", tt.in, got, tt.want)
  2636  		}
  2637  	}
  2638  }
  2639  
  2640  // Test that Redirect sets Content-Type header for GET and HEAD requests
  2641  // and writes a short HTML body, unless the request already has a Content-Type header.
  2642  func TestRedirectContentTypeAndBody(t *testing.T) {
  2643  	type ctHeader struct {
  2644  		Values []string
  2645  	}
  2646  
  2647  	var tests = []struct {
  2648  		method   string
  2649  		ct       *ctHeader // Optional Content-Type header to set.
  2650  		wantCT   string
  2651  		wantBody string
  2652  	}{
  2653  		{MethodGet, nil, "text/html; charset=utf-8", "<a href=\"/foo\">Found</a>.\n\n"},
  2654  		{MethodHead, nil, "text/html; charset=utf-8", ""},
  2655  		{MethodPost, nil, "", ""},
  2656  		{MethodDelete, nil, "", ""},
  2657  		{"foo", nil, "", ""},
  2658  		{MethodGet, &ctHeader{[]string{"application/test"}}, "application/test", ""},
  2659  		{MethodGet, &ctHeader{[]string{}}, "", ""},
  2660  		{MethodGet, &ctHeader{nil}, "", ""},
  2661  	}
  2662  	for _, tt := range tests {
  2663  		req := httptest.NewRequest(tt.method, "http://example.com/qux/", nil)
  2664  		rec := httptest.NewRecorder()
  2665  		if tt.ct != nil {
  2666  			rec.Header()["Content-Type"] = tt.ct.Values
  2667  		}
  2668  		Redirect(rec, req, "/foo", 302)
  2669  		if got, want := rec.Code, 302; got != want {
  2670  			t.Errorf("Redirect(%q, %#v) generated status code %v; want %v", tt.method, tt.ct, got, want)
  2671  		}
  2672  		if got, want := rec.Header().Get("Content-Type"), tt.wantCT; got != want {
  2673  			t.Errorf("Redirect(%q, %#v) generated Content-Type header %q; want %q", tt.method, tt.ct, got, want)
  2674  		}
  2675  		resp := rec.Result()
  2676  		body, err := io.ReadAll(resp.Body)
  2677  		if err != nil {
  2678  			t.Fatal(err)
  2679  		}
  2680  		if got, want := string(body), tt.wantBody; got != want {
  2681  			t.Errorf("Redirect(%q, %#v) generated Body %q; want %q", tt.method, tt.ct, got, want)
  2682  		}
  2683  	}
  2684  }
  2685  
  2686  // TestZeroLengthPostAndResponse exercises an optimization done by the Transport:
  2687  // when there is no body (either because the method doesn't permit a body, or an
  2688  // explicit Content-Length of zero is present), then the transport can re-use the
  2689  // connection immediately. But when it re-uses the connection, it typically closes
  2690  // the previous request's body, which is not optimal for zero-lengthed bodies,
  2691  // as the client would then see http.ErrBodyReadAfterClose and not 0, io.EOF.
  2692  func TestZeroLengthPostAndResponse(t *testing.T) { run(t, testZeroLengthPostAndResponse) }
  2693  
  2694  func testZeroLengthPostAndResponse(t *testing.T, mode testMode) {
  2695  	cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  2696  		all, err := io.ReadAll(r.Body)
  2697  		if err != nil {
  2698  			t.Fatalf("handler ReadAll: %v", err)
  2699  		}
  2700  		if len(all) != 0 {
  2701  			t.Errorf("handler got %d bytes; expected 0", len(all))
  2702  		}
  2703  		rw.Header().Set("Content-Length", "0")
  2704  	}))
  2705  
  2706  	req, err := NewRequest("POST", cst.ts.URL, strings.NewReader(""))
  2707  	if err != nil {
  2708  		t.Fatal(err)
  2709  	}
  2710  	req.ContentLength = 0
  2711  
  2712  	var resp [5]*Response
  2713  	for i := range resp {
  2714  		resp[i], err = cst.c.Do(req)
  2715  		if err != nil {
  2716  			t.Fatalf("client post #%d: %v", i, err)
  2717  		}
  2718  	}
  2719  
  2720  	for i := range resp {
  2721  		all, err := io.ReadAll(resp[i].Body)
  2722  		if err != nil {
  2723  			t.Fatalf("req #%d: client ReadAll: %v", i, err)
  2724  		}
  2725  		if len(all) != 0 {
  2726  			t.Errorf("req #%d: client got %d bytes; expected 0", i, len(all))
  2727  		}
  2728  	}
  2729  }
  2730  
  2731  func TestHandlerPanicNil(t *testing.T) {
  2732  	run(t, func(t *testing.T, mode testMode) {
  2733  		testHandlerPanic(t, false, mode, nil, nil)
  2734  	}, testNotParallel)
  2735  }
  2736  
  2737  func TestHandlerPanic(t *testing.T) {
  2738  	run(t, func(t *testing.T, mode testMode) {
  2739  		testHandlerPanic(t, false, mode, nil, "intentional death for testing")
  2740  	}, testNotParallel)
  2741  }
  2742  
  2743  func TestHandlerPanicWithHijack(t *testing.T) {
  2744  	// Only testing HTTP/1, and our http2 server doesn't support hijacking.
  2745  	run(t, func(t *testing.T, mode testMode) {
  2746  		testHandlerPanic(t, true, mode, nil, "intentional death for testing")
  2747  	}, []testMode{http1Mode})
  2748  }
  2749  
  2750  func testHandlerPanic(t *testing.T, withHijack bool, mode testMode, wrapper func(Handler) Handler, panicValue any) {
  2751  	// Direct log output to a pipe.
  2752  	//
  2753  	// We read from the pipe to verify that the handler actually caught the panic
  2754  	// and logged something.
  2755  	//
  2756  	// We use a pipe rather than a buffer, because when testing connection hijacking
  2757  	// server shutdown doesn't wait for the hijacking handler to return, so the
  2758  	// log may occur after the server has shut down.
  2759  	pr, pw := io.Pipe()
  2760  	defer pw.Close()
  2761  
  2762  	var handler Handler = HandlerFunc(func(w ResponseWriter, r *Request) {
  2763  		if withHijack {
  2764  			rwc, _, err := w.(Hijacker).Hijack()
  2765  			if err != nil {
  2766  				t.Logf("unexpected error: %v", err)
  2767  			}
  2768  			defer rwc.Close()
  2769  		}
  2770  		panic(panicValue)
  2771  	})
  2772  	if wrapper != nil {
  2773  		handler = wrapper(handler)
  2774  	}
  2775  	cst := newClientServerTest(t, mode, handler, func(ts *httptest.Server) {
  2776  		ts.Config.ErrorLog = log.New(pw, "", 0)
  2777  	})
  2778  
  2779  	// Do a blocking read on the log output pipe.
  2780  	done := make(chan bool, 1)
  2781  	go func() {
  2782  		buf := make([]byte, 4<<10)
  2783  		_, err := pr.Read(buf)
  2784  		pr.Close()
  2785  		if err != nil && err != io.EOF {
  2786  			t.Error(err)
  2787  		}
  2788  		done <- true
  2789  	}()
  2790  
  2791  	_, err := cst.c.Get(cst.ts.URL)
  2792  	if err == nil {
  2793  		t.Logf("expected an error")
  2794  	}
  2795  
  2796  	if panicValue == nil {
  2797  		return
  2798  	}
  2799  
  2800  	<-done
  2801  }
  2802  
  2803  type terrorWriter struct{ t *testing.T }
  2804  
  2805  func (w terrorWriter) Write(p []byte) (int, error) {
  2806  	w.t.Errorf("%s", p)
  2807  	return len(p), nil
  2808  }
  2809  
  2810  // Issue 16456: allow writing 0 bytes on hijacked conn to test hijack
  2811  // without any log spam.
  2812  func TestServerWriteHijackZeroBytes(t *testing.T) {
  2813  	run(t, testServerWriteHijackZeroBytes, []testMode{http1Mode})
  2814  }
  2815  func testServerWriteHijackZeroBytes(t *testing.T, mode testMode) {
  2816  	done := make(chan struct{})
  2817  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  2818  		defer close(done)
  2819  		w.(Flusher).Flush()
  2820  		conn, _, err := w.(Hijacker).Hijack()
  2821  		if err != nil {
  2822  			t.Errorf("Hijack: %v", err)
  2823  			return
  2824  		}
  2825  		defer conn.Close()
  2826  		_, err = w.Write(nil)
  2827  		if err != ErrHijacked {
  2828  			t.Errorf("Write error = %v; want ErrHijacked", err)
  2829  		}
  2830  	}), func(ts *httptest.Server) {
  2831  		ts.Config.ErrorLog = log.New(terrorWriter{t}, "Unexpected write: ", 0)
  2832  	}).ts
  2833  
  2834  	c := ts.Client()
  2835  	res, err := c.Get(ts.URL)
  2836  	if err != nil {
  2837  		t.Fatal(err)
  2838  	}
  2839  	res.Body.Close()
  2840  	<-done
  2841  }
  2842  
  2843  func TestServerNoDate(t *testing.T) {
  2844  	run(t, func(t *testing.T, mode testMode) {
  2845  		testServerNoHeader(t, mode, "Date")
  2846  	})
  2847  }
  2848  
  2849  func TestServerContentType(t *testing.T) {
  2850  	run(t, func(t *testing.T, mode testMode) {
  2851  		testServerNoHeader(t, mode, "Content-Type")
  2852  	})
  2853  }
  2854  
  2855  func testServerNoHeader(t *testing.T, mode testMode, header string) {
  2856  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  2857  		w.Header()[header] = nil
  2858  		io.WriteString(w, "<html>foo</html>") // non-empty
  2859  	}))
  2860  	res, err := cst.c.Get(cst.ts.URL)
  2861  	if err != nil {
  2862  		t.Fatal(err)
  2863  	}
  2864  	res.Body.Close()
  2865  	if got, ok := res.Header[header]; ok {
  2866  		t.Fatalf("Expected no %s header; got %q", header, got)
  2867  	}
  2868  }
  2869  
  2870  func TestStripPrefix(t *testing.T) { run(t, testStripPrefix) }
  2871  func testStripPrefix(t *testing.T, mode testMode) {
  2872  	h := HandlerFunc(func(w ResponseWriter, r *Request) {
  2873  		w.Header().Set("X-Path", r.URL.Path)
  2874  		w.Header().Set("X-RawPath", r.URL.RawPath)
  2875  	})
  2876  	ts := newClientServerTest(t, mode, StripPrefix("/foo/bar", h)).ts
  2877  
  2878  	c := ts.Client()
  2879  
  2880  	cases := []struct {
  2881  		reqPath string
  2882  		path    string // If empty we want a 404.
  2883  		rawPath string
  2884  	}{
  2885  		{"/foo/bar/qux", "/qux", ""},
  2886  		{"/foo/bar%2Fqux", "/qux", "%2Fqux"},
  2887  		{"/foo%2Fbar/qux", "", ""}, // Escaped prefix does not match.
  2888  		{"/bar", "", ""},           // No prefix match.
  2889  	}
  2890  	for _, tc := range cases {
  2891  		t.Run(tc.reqPath, func(t *testing.T) {
  2892  			res, err := c.Get(ts.URL + tc.reqPath)
  2893  			if err != nil {
  2894  				t.Fatal(err)
  2895  			}
  2896  			res.Body.Close()
  2897  			if tc.path == "" {
  2898  				if res.StatusCode != StatusNotFound {
  2899  					t.Errorf("got %q, want 404 Not Found", res.Status)
  2900  				}
  2901  				return
  2902  			}
  2903  			if res.StatusCode != StatusOK {
  2904  				t.Fatalf("got %q, want 200 OK", res.Status)
  2905  			}
  2906  			if g, w := res.Header.Get("X-Path"), tc.path; g != w {
  2907  				t.Errorf("got Path %q, want %q", g, w)
  2908  			}
  2909  			if g, w := res.Header.Get("X-RawPath"), tc.rawPath; g != w {
  2910  				t.Errorf("got RawPath %q, want %q", g, w)
  2911  			}
  2912  		})
  2913  	}
  2914  }
  2915  
  2916  // https://golang.org/issue/18952.
  2917  func TestStripPrefixNotModifyRequest(t *testing.T) {
  2918  	h := StripPrefix("/foo", NotFoundHandler())
  2919  	req := httptest.NewRequest("GET", "/foo/bar", nil)
  2920  	h.ServeHTTP(httptest.NewRecorder(), req)
  2921  	if req.URL.Path != "/foo/bar" {
  2922  		t.Errorf("StripPrefix should not modify the provided Request, but it did")
  2923  	}
  2924  }
  2925  
  2926  func TestRequestLimit(t *testing.T) { run(t, testRequestLimit) }
  2927  func testRequestLimit(t *testing.T, mode testMode) {
  2928  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  2929  		t.Fatalf("didn't expect to get request in Handler")
  2930  	}), optQuietLog)
  2931  	req, _ := NewRequest("GET", cst.ts.URL, nil)
  2932  	var bytesPerHeader = len("header12345: val12345\r\n")
  2933  	for i := 0; i < ((DefaultMaxHeaderBytes+4096)/bytesPerHeader)+1; i++ {
  2934  		req.Header.Set(fmt.Sprintf("header%05d", i), fmt.Sprintf("val%05d", i))
  2935  	}
  2936  	res, err := cst.c.Do(req)
  2937  	if res != nil {
  2938  		defer res.Body.Close()
  2939  	}
  2940  	if mode == http2Mode {
  2941  		// In HTTP/2, the result depends on a race. If the client has received the
  2942  		// server's SETTINGS before RoundTrip starts sending the request, then RoundTrip
  2943  		// will fail with an error. Otherwise, the client should receive a 431 from the
  2944  		// server.
  2945  		if err == nil && res.StatusCode != 431 {
  2946  			t.Fatalf("expected 431 response status; got: %d %s", res.StatusCode, res.Status)
  2947  		}
  2948  	} else {
  2949  		// In HTTP/1, we expect a 431 from the server.
  2950  		// Some HTTP clients may fail on this undefined behavior (server replying and
  2951  		// closing the connection while the request is still being written), but
  2952  		// we do support it (at least currently), so we expect a response below.
  2953  		if err != nil {
  2954  			t.Fatalf("Do: %v", err)
  2955  		}
  2956  		if res.StatusCode != 431 {
  2957  			t.Fatalf("expected 431 response status; got: %d %s", res.StatusCode, res.Status)
  2958  		}
  2959  	}
  2960  }
  2961  
  2962  type neverEnding byte
  2963  
  2964  func (b neverEnding) Read(p []byte) (n int, err error) {
  2965  	for i := range p {
  2966  		p[i] = byte(b)
  2967  	}
  2968  	return len(p), nil
  2969  }
  2970  
  2971  type countReader struct {
  2972  	r io.Reader
  2973  	n *int64
  2974  }
  2975  
  2976  func (cr countReader) Read(p []byte) (n int, err error) {
  2977  	n, err = cr.r.Read(p)
  2978  	atomic.AddInt64(cr.n, int64(n))
  2979  	return
  2980  }
  2981  
  2982  func TestRequestBodyLimit(t *testing.T) { run(t, testRequestBodyLimit) }
  2983  func testRequestBodyLimit(t *testing.T, mode testMode) {
  2984  	const limit = 1 << 20
  2985  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  2986  		r.Body = MaxBytesReader(w, r.Body, limit)
  2987  		n, err := io.Copy(io.Discard, r.Body)
  2988  		if err == nil {
  2989  			t.Errorf("expected error from io.Copy")
  2990  		}
  2991  		if n != limit {
  2992  			t.Errorf("io.Copy = %d, want %d", n, limit)
  2993  		}
  2994  		mbErr, ok := err.(*MaxBytesError)
  2995  		if !ok {
  2996  			t.Errorf("expected MaxBytesError, got %T", err)
  2997  		}
  2998  		if mbErr.Limit != limit {
  2999  			t.Errorf("MaxBytesError.Limit = %d, want %d", mbErr.Limit, limit)
  3000  		}
  3001  	}))
  3002  
  3003  	nWritten := new(int64)
  3004  	req, _ := NewRequest("POST", cst.ts.URL, io.LimitReader(countReader{neverEnding('a'), nWritten}, limit*200))
  3005  
  3006  	// Send the POST, but don't care it succeeds or not. The
  3007  	// remote side is going to reply and then close the TCP
  3008  	// connection, and HTTP doesn't really define if that's
  3009  	// allowed or not. Some HTTP clients will get the response
  3010  	// and some (like ours, currently) will complain that the
  3011  	// request write failed, without reading the response.
  3012  	//
  3013  	// But that's okay, since what we're really testing is that
  3014  	// the remote side hung up on us before we wrote too much.
  3015  	resp, err := cst.c.Do(req)
  3016  	if err == nil {
  3017  		resp.Body.Close()
  3018  	}
  3019  
  3020  	if atomic.LoadInt64(nWritten) > limit*100 {
  3021  		t.Errorf("handler restricted the request body to %d bytes, but client managed to write %d",
  3022  			limit, nWritten)
  3023  	}
  3024  }
  3025  
  3026  // TestClientWriteShutdown tests that if the client shuts down the write
  3027  // side of their TCP connection, the server doesn't send a 400 Bad Request.
  3028  func TestClientWriteShutdown(t *testing.T) { run(t, testClientWriteShutdown) }
  3029  func testClientWriteShutdown(t *testing.T, mode testMode) {
  3030  	if runtime.GOOS == "plan9" {
  3031  		t.Skip("skipping test; see https://golang.org/issue/17906")
  3032  	}
  3033  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {})).ts
  3034  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3035  	if err != nil {
  3036  		t.Fatalf("Dial: %v", err)
  3037  	}
  3038  	err = conn.(*net.TCPConn).CloseWrite()
  3039  	if err != nil {
  3040  		t.Fatalf("CloseWrite: %v", err)
  3041  	}
  3042  
  3043  	bs, err := io.ReadAll(conn)
  3044  	if err != nil {
  3045  		t.Errorf("ReadAll: %v", err)
  3046  	}
  3047  	got := string(bs)
  3048  	if got != "" {
  3049  		t.Errorf("read %q from server; want nothing", got)
  3050  	}
  3051  }
  3052  
  3053  // Tests that chunked server responses that write 1 byte at a time are
  3054  // buffered before chunk headers are added, not after chunk headers.
  3055  func TestServerBufferedChunking(t *testing.T) {
  3056  	conn := new(testConn)
  3057  	conn.readBuf.Write([]byte("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"))
  3058  	conn.closec = make(chan bool, 1)
  3059  	ls := &oneConnListener{conn}
  3060  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3061  		rw.(Flusher).Flush() // force the Header to be sent, in chunking mode, not counting the length
  3062  		rw.Write([]byte{'x'})
  3063  		rw.Write([]byte{'y'})
  3064  		rw.Write([]byte{'z'})
  3065  	}))
  3066  	<-conn.closec
  3067  	if !bytes.HasSuffix(conn.writeBuf.Bytes(), []byte("\r\n\r\n3\r\nxyz\r\n0\r\n\r\n")) {
  3068  		t.Errorf("response didn't end with a single 3 byte 'xyz' chunk; got:\n%q",
  3069  			conn.writeBuf.Bytes())
  3070  	}
  3071  }
  3072  
  3073  // Tests that the server flushes its response headers out when it's
  3074  // ignoring the response body and waits a bit before forcefully
  3075  // closing the TCP connection, causing the client to get a RST.
  3076  // See https://golang.org/issue/3595
  3077  func TestServerGracefulClose(t *testing.T) {
  3078  	run(t, testServerGracefulClose, []testMode{http1Mode})
  3079  }
  3080  func testServerGracefulClose(t *testing.T, mode testMode) {
  3081  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3082  		Error(w, "bye", StatusUnauthorized)
  3083  	})).ts
  3084  
  3085  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3086  	if err != nil {
  3087  		t.Fatal(err)
  3088  	}
  3089  	defer conn.Close()
  3090  	const bodySize = 5 << 20
  3091  	req := []byte(fmt.Sprintf("POST / HTTP/1.1\r\nHost: foo.com\r\nContent-Length: %d\r\n\r\n", bodySize))
  3092  	for i := 0; i < bodySize; i++ {
  3093  		req = append(req, 'x')
  3094  	}
  3095  	writeErr := make(chan error)
  3096  	go func() {
  3097  		_, err := conn.Write(req)
  3098  		writeErr <- err
  3099  	}()
  3100  	br := bufio.NewReader(conn)
  3101  	lineNum := 0
  3102  	for {
  3103  		line, err := br.ReadString('\n')
  3104  		if err == io.EOF {
  3105  			break
  3106  		}
  3107  		if err != nil {
  3108  			t.Fatalf("ReadLine: %v", err)
  3109  		}
  3110  		lineNum++
  3111  		if lineNum == 1 && !strings.Contains(line, "401 Unauthorized") {
  3112  			t.Errorf("Response line = %q; want a 401", line)
  3113  		}
  3114  	}
  3115  	// Wait for write to finish. This is a broken pipe on both
  3116  	// Darwin and Linux, but checking this isn't the point of
  3117  	// the test.
  3118  	<-writeErr
  3119  }
  3120  
  3121  func TestCaseSensitiveMethod(t *testing.T) { run(t, testCaseSensitiveMethod) }
  3122  func testCaseSensitiveMethod(t *testing.T, mode testMode) {
  3123  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3124  		if r.Method != "get" {
  3125  			t.Errorf(`Got method %q; want "get"`, r.Method)
  3126  		}
  3127  	}))
  3128  	defer cst.close()
  3129  	req, _ := NewRequest("get", cst.ts.URL, nil)
  3130  	res, err := cst.c.Do(req)
  3131  	if err != nil {
  3132  		t.Error(err)
  3133  		return
  3134  	}
  3135  
  3136  	res.Body.Close()
  3137  }
  3138  
  3139  // TestContentLengthZero tests that for both an HTTP/1.0 and HTTP/1.1
  3140  // request (both keep-alive), when a Handler never writes any
  3141  // response, the net/http package adds a "Content-Length: 0" response
  3142  // header.
  3143  func TestContentLengthZero(t *testing.T) {
  3144  	run(t, testContentLengthZero, []testMode{http1Mode})
  3145  }
  3146  func testContentLengthZero(t *testing.T, mode testMode) {
  3147  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {})).ts
  3148  
  3149  	for _, version := range []string{"HTTP/1.0", "HTTP/1.1"} {
  3150  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3151  		if err != nil {
  3152  			t.Fatalf("error dialing: %v", err)
  3153  		}
  3154  		_, err = fmt.Fprintf(conn, "GET / %v\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n", version)
  3155  		if err != nil {
  3156  			t.Fatalf("error writing: %v", err)
  3157  		}
  3158  		req, _ := NewRequest("GET", "/", nil)
  3159  		res, err := ReadResponse(bufio.NewReader(conn), req)
  3160  		if err != nil {
  3161  			t.Fatalf("error reading response: %v", err)
  3162  		}
  3163  		if te := res.TransferEncoding; len(te) > 0 {
  3164  			t.Errorf("For version %q, Transfer-Encoding = %q; want none", version, te)
  3165  		}
  3166  		if cl := res.ContentLength; cl != 0 {
  3167  			t.Errorf("For version %q, Content-Length = %v; want 0", version, cl)
  3168  		}
  3169  		conn.Close()
  3170  	}
  3171  }
  3172  
  3173  func TestCloseNotifier(t *testing.T) {
  3174  	run(t, testCloseNotifier, []testMode{http1Mode})
  3175  }
  3176  func testCloseNotifier(t *testing.T, mode testMode) {
  3177  	gotReq := make(chan bool, 1)
  3178  	sawClose := make(chan bool, 1)
  3179  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3180  		gotReq <- true
  3181  		cc := rw.(CloseNotifier).CloseNotify()
  3182  		<-cc
  3183  		sawClose <- true
  3184  	})).ts
  3185  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3186  	if err != nil {
  3187  		t.Fatalf("error dialing: %v", err)
  3188  	}
  3189  	diec := make(chan bool)
  3190  	go func() {
  3191  		_, err = fmt.Fprintf(conn, "GET / HTTP/1.1\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n")
  3192  		if err != nil {
  3193  			t.Error(err)
  3194  			return
  3195  		}
  3196  		<-diec
  3197  		conn.Close()
  3198  	}()
  3199  For:
  3200  	for {
  3201  		select {
  3202  		case <-gotReq:
  3203  			diec <- true
  3204  		case <-sawClose:
  3205  			break For
  3206  		}
  3207  	}
  3208  	ts.Close()
  3209  }
  3210  
  3211  // Tests that a pipelined request does not cause the first request's
  3212  // Handler's CloseNotify channel to fire.
  3213  //
  3214  // Issue 13165 (where it used to deadlock), but behavior changed in Issue 23921.
  3215  func TestCloseNotifierPipelined(t *testing.T) {
  3216  	run(t, testCloseNotifierPipelined, []testMode{http1Mode})
  3217  }
  3218  func testCloseNotifierPipelined(t *testing.T, mode testMode) {
  3219  	gotReq := make(chan bool, 2)
  3220  	sawClose := make(chan bool, 2)
  3221  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3222  		gotReq <- true
  3223  		cc := rw.(CloseNotifier).CloseNotify()
  3224  		select {
  3225  		case <-cc:
  3226  			t.Error("unexpected CloseNotify")
  3227  		case <-time.After(100 * time.Millisecond):
  3228  		}
  3229  		sawClose <- true
  3230  	})).ts
  3231  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3232  	if err != nil {
  3233  		t.Fatalf("error dialing: %v", err)
  3234  	}
  3235  	diec := make(chan bool, 1)
  3236  	defer close(diec)
  3237  	go func() {
  3238  		const req = "GET / HTTP/1.1\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n"
  3239  		_, err = io.WriteString(conn, req+req) // two requests
  3240  		if err != nil {
  3241  			t.Error(err)
  3242  			return
  3243  		}
  3244  		<-diec
  3245  		conn.Close()
  3246  	}()
  3247  	reqs := 0
  3248  	closes := 0
  3249  	for {
  3250  		select {
  3251  		case <-gotReq:
  3252  			reqs++
  3253  			if reqs > 2 {
  3254  				t.Fatal("too many requests")
  3255  			}
  3256  		case <-sawClose:
  3257  			closes++
  3258  			if closes > 1 {
  3259  				return
  3260  			}
  3261  		}
  3262  	}
  3263  }
  3264  
  3265  func TestCloseNotifierChanLeak(t *testing.T) {
  3266  	defer afterTest(t)
  3267  	req := reqBytes("GET / HTTP/1.0\nHost: golang.org")
  3268  	for i := 0; i < 20; i++ {
  3269  		var output bytes.Buffer
  3270  		conn := &rwTestConn{
  3271  			Reader: bytes.NewReader(req),
  3272  			Writer: &output,
  3273  			closec: make(chan bool, 1),
  3274  		}
  3275  		ln := &oneConnListener{conn: conn}
  3276  		handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  3277  			// Ignore the return value and never read from
  3278  			// it, testing that we don't leak goroutines
  3279  			// on the sending side:
  3280  			_ = rw.(CloseNotifier).CloseNotify()
  3281  		})
  3282  		go Serve(ln, handler)
  3283  		<-conn.closec
  3284  	}
  3285  }
  3286  
  3287  // Tests that we can use CloseNotifier in one request, and later call Hijack
  3288  // on a second request on the same connection.
  3289  //
  3290  // It also tests that the connReader stitches together its background
  3291  // 1-byte read for CloseNotifier when CloseNotifier doesn't fire with
  3292  // the rest of the second HTTP later.
  3293  //
  3294  // Issue 9763.
  3295  // HTTP/1-only test. (http2 doesn't have Hijack)
  3296  func TestHijackAfterCloseNotifier(t *testing.T) {
  3297  	run(t, testHijackAfterCloseNotifier, []testMode{http1Mode})
  3298  }
  3299  func testHijackAfterCloseNotifier(t *testing.T, mode testMode) {
  3300  	script := make(chan string, 2)
  3301  	script <- "closenotify"
  3302  	script <- "hijack"
  3303  	close(script)
  3304  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3305  		plan := <-script
  3306  		switch plan {
  3307  		default:
  3308  			panic("bogus plan; too many requests")
  3309  		case "closenotify":
  3310  			w.(CloseNotifier).CloseNotify() // discard result
  3311  			w.Header().Set("X-Addr", r.RemoteAddr)
  3312  		case "hijack":
  3313  			c, _, err := w.(Hijacker).Hijack()
  3314  			if err != nil {
  3315  				t.Errorf("Hijack in Handler: %v", err)
  3316  				return
  3317  			}
  3318  			if _, ok := c.(*net.TCPConn); !ok {
  3319  				// Verify it's not wrapped in some type.
  3320  				// Not strictly a go1 compat issue, but in practice it probably is.
  3321  				t.Errorf("type of hijacked conn is %T; want *net.TCPConn", c)
  3322  			}
  3323  			fmt.Fprintf(c, "HTTP/1.0 200 OK\r\nX-Addr: %v\r\nContent-Length: 0\r\n\r\n", r.RemoteAddr)
  3324  			c.Close()
  3325  			return
  3326  		}
  3327  	})).ts
  3328  	res1, err := ts.Client().Get(ts.URL)
  3329  	if err != nil {
  3330  		log.Fatal(err)
  3331  	}
  3332  	res2, err := ts.Client().Get(ts.URL)
  3333  	if err != nil {
  3334  		log.Fatal(err)
  3335  	}
  3336  	addr1 := res1.Header.Get("X-Addr")
  3337  	addr2 := res2.Header.Get("X-Addr")
  3338  	if addr1 == "" || addr1 != addr2 {
  3339  		t.Errorf("addr1, addr2 = %q, %q; want same", addr1, addr2)
  3340  	}
  3341  }
  3342  
  3343  func TestHijackBeforeRequestBodyRead(t *testing.T) {
  3344  	run(t, testHijackBeforeRequestBodyRead, []testMode{http1Mode})
  3345  }
  3346  func testHijackBeforeRequestBodyRead(t *testing.T, mode testMode) {
  3347  	var requestBody = bytes.Repeat([]byte("a"), 1<<20)
  3348  	bodyOkay := make(chan bool, 1)
  3349  	gotCloseNotify := make(chan bool, 1)
  3350  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3351  		defer close(bodyOkay) // caller will read false if nothing else
  3352  
  3353  		reqBody := r.Body
  3354  		r.Body = nil // to test that server.go doesn't use this value.
  3355  
  3356  		gone := w.(CloseNotifier).CloseNotify()
  3357  		slurp, err := io.ReadAll(reqBody)
  3358  		if err != nil {
  3359  			t.Errorf("Body read: %v", err)
  3360  			return
  3361  		}
  3362  		if len(slurp) != len(requestBody) {
  3363  			t.Errorf("Backend read %d request body bytes; want %d", len(slurp), len(requestBody))
  3364  			return
  3365  		}
  3366  		if !bytes.Equal(slurp, requestBody) {
  3367  			t.Error("Backend read wrong request body.") // 1MB; omitting details
  3368  			return
  3369  		}
  3370  		bodyOkay <- true
  3371  		<-gone
  3372  		gotCloseNotify <- true
  3373  	})).ts
  3374  
  3375  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3376  	if err != nil {
  3377  		t.Fatal(err)
  3378  	}
  3379  	defer conn.Close()
  3380  
  3381  	fmt.Fprintf(conn, "POST / HTTP/1.1\r\nHost: foo\r\nContent-Length: %d\r\n\r\n%s",
  3382  		len(requestBody), requestBody)
  3383  	if !<-bodyOkay {
  3384  		// already failed.
  3385  		return
  3386  	}
  3387  	conn.Close()
  3388  	<-gotCloseNotify
  3389  }
  3390  
  3391  func TestOptions(t *testing.T) { run(t, testOptions, []testMode{http1Mode}) }
  3392  func testOptions(t *testing.T, mode testMode) {
  3393  	uric := make(chan string, 2) // only expect 1, but leave space for 2
  3394  	mux := NewServeMux()
  3395  	mux.HandleFunc("/", func(w ResponseWriter, r *Request) {
  3396  		uric <- r.RequestURI
  3397  	})
  3398  	ts := newClientServerTest(t, mode, mux).ts
  3399  
  3400  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3401  	if err != nil {
  3402  		t.Fatal(err)
  3403  	}
  3404  	defer conn.Close()
  3405  
  3406  	// An OPTIONS * request should succeed.
  3407  	_, err = conn.Write([]byte("OPTIONS * HTTP/1.1\r\nHost: foo.com\r\n\r\n"))
  3408  	if err != nil {
  3409  		t.Fatal(err)
  3410  	}
  3411  	br := bufio.NewReader(conn)
  3412  	res, err := ReadResponse(br, &Request{Method: "OPTIONS"})
  3413  	if err != nil {
  3414  		t.Fatal(err)
  3415  	}
  3416  	if res.StatusCode != 200 {
  3417  		t.Errorf("Got non-200 response to OPTIONS *: %#v", res)
  3418  	}
  3419  
  3420  	// A GET * request on a ServeMux should fail.
  3421  	_, err = conn.Write([]byte("GET * HTTP/1.1\r\nHost: foo.com\r\n\r\n"))
  3422  	if err != nil {
  3423  		t.Fatal(err)
  3424  	}
  3425  	res, err = ReadResponse(br, &Request{Method: "GET"})
  3426  	if err != nil {
  3427  		t.Fatal(err)
  3428  	}
  3429  	if res.StatusCode != 400 {
  3430  		t.Errorf("Got non-400 response to GET *: %#v", res)
  3431  	}
  3432  
  3433  	res, err = Get(ts.URL + "/second")
  3434  	if err != nil {
  3435  		t.Fatal(err)
  3436  	}
  3437  	res.Body.Close()
  3438  	if got := <-uric; got != "/second" {
  3439  		t.Errorf("Handler saw request for %q; want /second", got)
  3440  	}
  3441  }
  3442  
  3443  func TestOptionsHandler(t *testing.T) { run(t, testOptionsHandler, []testMode{http1Mode}) }
  3444  func testOptionsHandler(t *testing.T, mode testMode) {
  3445  	rc := make(chan *Request, 1)
  3446  
  3447  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  3448  		rc <- r
  3449  	}), func(ts *httptest.Server) {
  3450  		ts.Config.DisableGeneralOptionsHandler = true
  3451  	}).ts
  3452  
  3453  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3454  	if err != nil {
  3455  		t.Fatal(err)
  3456  	}
  3457  	defer conn.Close()
  3458  
  3459  	_, err = conn.Write([]byte("OPTIONS * HTTP/1.1\r\nHost: foo.com\r\n\r\n"))
  3460  	if err != nil {
  3461  		t.Fatal(err)
  3462  	}
  3463  
  3464  	if got := <-rc; got.Method != "OPTIONS" || got.RequestURI != "*" {
  3465  		t.Errorf("Expected OPTIONS * request, got %v", got)
  3466  	}
  3467  }
  3468  
  3469  // Tests regarding the ordering of Write, WriteHeader, Header, and
  3470  // Flush calls. In Go 1.0, rw.WriteHeader immediately flushed the
  3471  // (*response).header to the wire. In Go 1.1, the actual wire flush is
  3472  // delayed, so we could maybe tack on a Content-Length and better
  3473  // Content-Type after we see more (or all) of the output. To preserve
  3474  // compatibility with Go 1, we need to be careful to track which
  3475  // headers were live at the time of WriteHeader, so we write the same
  3476  // ones, even if the handler modifies them (~erroneously) after the
  3477  // first Write.
  3478  func TestHeaderToWire(t *testing.T) {
  3479  	tests := []struct {
  3480  		name    string
  3481  		handler func(ResponseWriter, *Request)
  3482  		check   func(got, logs string) error
  3483  	}{
  3484  		{
  3485  			name: "write without Header",
  3486  			handler: func(rw ResponseWriter, r *Request) {
  3487  				rw.Write([]byte("hello world"))
  3488  			},
  3489  			check: func(got, logs string) error {
  3490  				if !strings.Contains(got, "Content-Length:") {
  3491  					return errors.New("no content-length")
  3492  				}
  3493  				if !strings.Contains(got, "Content-Type: text/plain") {
  3494  					return errors.New("no content-type")
  3495  				}
  3496  				return nil
  3497  			},
  3498  		},
  3499  		{
  3500  			name: "Header mutation before write",
  3501  			handler: func(rw ResponseWriter, r *Request) {
  3502  				h := rw.Header()
  3503  				h.Set("Content-Type", "some/type")
  3504  				rw.Write([]byte("hello world"))
  3505  				h.Set("Too-Late", "bogus")
  3506  			},
  3507  			check: func(got, logs string) error {
  3508  				if !strings.Contains(got, "Content-Length:") {
  3509  					return errors.New("no content-length")
  3510  				}
  3511  				if !strings.Contains(got, "Content-Type: some/type") {
  3512  					return errors.New("wrong content-type")
  3513  				}
  3514  				if strings.Contains(got, "Too-Late") {
  3515  					return errors.New("don't want too-late header")
  3516  				}
  3517  				return nil
  3518  			},
  3519  		},
  3520  		{
  3521  			name: "write then useless Header mutation",
  3522  			handler: func(rw ResponseWriter, r *Request) {
  3523  				rw.Write([]byte("hello world"))
  3524  				rw.Header().Set("Too-Late", "Write already wrote headers")
  3525  			},
  3526  			check: func(got, logs string) error {
  3527  				if strings.Contains(got, "Too-Late") {
  3528  					return errors.New("header appeared from after WriteHeader")
  3529  				}
  3530  				return nil
  3531  			},
  3532  		},
  3533  		{
  3534  			name: "flush then write",
  3535  			handler: func(rw ResponseWriter, r *Request) {
  3536  				rw.(Flusher).Flush()
  3537  				rw.Write([]byte("post-flush"))
  3538  				rw.Header().Set("Too-Late", "Write already wrote headers")
  3539  			},
  3540  			check: func(got, logs string) error {
  3541  				if !strings.Contains(got, "Transfer-Encoding: chunked") {
  3542  					return errors.New("not chunked")
  3543  				}
  3544  				if strings.Contains(got, "Too-Late") {
  3545  					return errors.New("header appeared from after WriteHeader")
  3546  				}
  3547  				return nil
  3548  			},
  3549  		},
  3550  		{
  3551  			name: "header then flush",
  3552  			handler: func(rw ResponseWriter, r *Request) {
  3553  				rw.Header().Set("Content-Type", "some/type")
  3554  				rw.(Flusher).Flush()
  3555  				rw.Write([]byte("post-flush"))
  3556  				rw.Header().Set("Too-Late", "Write already wrote headers")
  3557  			},
  3558  			check: func(got, logs string) error {
  3559  				if !strings.Contains(got, "Transfer-Encoding: chunked") {
  3560  					return errors.New("not chunked")
  3561  				}
  3562  				if strings.Contains(got, "Too-Late") {
  3563  					return errors.New("header appeared from after WriteHeader")
  3564  				}
  3565  				if !strings.Contains(got, "Content-Type: some/type") {
  3566  					return errors.New("wrong content-type")
  3567  				}
  3568  				return nil
  3569  			},
  3570  		},
  3571  		{
  3572  			name: "sniff-on-first-write content-type",
  3573  			handler: func(rw ResponseWriter, r *Request) {
  3574  				rw.Write([]byte("<html><head></head><body>some html</body></html>"))
  3575  				rw.Header().Set("Content-Type", "x/wrong")
  3576  			},
  3577  			check: func(got, logs string) error {
  3578  				if !strings.Contains(got, "Content-Type: text/html") {
  3579  					return errors.New("wrong content-type; want html")
  3580  				}
  3581  				return nil
  3582  			},
  3583  		},
  3584  		{
  3585  			name: "explicit content-type wins",
  3586  			handler: func(rw ResponseWriter, r *Request) {
  3587  				rw.Header().Set("Content-Type", "some/type")
  3588  				rw.Write([]byte("<html><head></head><body>some html</body></html>"))
  3589  			},
  3590  			check: func(got, logs string) error {
  3591  				if !strings.Contains(got, "Content-Type: some/type") {
  3592  					return errors.New("wrong content-type; want html")
  3593  				}
  3594  				return nil
  3595  			},
  3596  		},
  3597  		{
  3598  			name: "empty handler",
  3599  			handler: func(rw ResponseWriter, r *Request) {
  3600  			},
  3601  			check: func(got, logs string) error {
  3602  				if !strings.Contains(got, "Content-Length: 0") {
  3603  					return errors.New("want 0 content-length")
  3604  				}
  3605  				return nil
  3606  			},
  3607  		},
  3608  		{
  3609  			name: "only Header, no write",
  3610  			handler: func(rw ResponseWriter, r *Request) {
  3611  				rw.Header().Set("Some-Header", "some-value")
  3612  			},
  3613  			check: func(got, logs string) error {
  3614  				if !strings.Contains(got, "Some-Header") {
  3615  					return errors.New("didn't get header")
  3616  				}
  3617  				return nil
  3618  			},
  3619  		},
  3620  		{
  3621  			name: "WriteHeader call",
  3622  			handler: func(rw ResponseWriter, r *Request) {
  3623  				rw.WriteHeader(404)
  3624  				rw.Header().Set("Too-Late", "some-value")
  3625  			},
  3626  			check: func(got, logs string) error {
  3627  				if !strings.Contains(got, "404") {
  3628  					return errors.New("wrong status")
  3629  				}
  3630  				if strings.Contains(got, "Too-Late") {
  3631  					return errors.New("shouldn't have seen Too-Late")
  3632  				}
  3633  				return nil
  3634  			},
  3635  		},
  3636  	}
  3637  	for _, tc := range tests {
  3638  		ht := newHandlerTest(HandlerFunc(tc.handler))
  3639  		got := ht.rawResponse("GET / HTTP/1.1\nHost: golang.org")
  3640  		logs := ht.logbuf.String()
  3641  		if err := tc.check(got, logs); err != nil {
  3642  			t.Errorf("%s: %v\nGot response:\n%s\n\n%s", tc.name, err, got, logs)
  3643  		}
  3644  	}
  3645  }
  3646  
  3647  type errorListener struct {
  3648  	errs []error
  3649  }
  3650  
  3651  func (l *errorListener) Accept() (c net.Conn, err error) {
  3652  	if len(l.errs) == 0 {
  3653  		return nil, io.EOF
  3654  	}
  3655  	err = l.errs[0]
  3656  	l.errs = l.errs[1:]
  3657  	return
  3658  }
  3659  
  3660  func (l *errorListener) Close() error {
  3661  	return nil
  3662  }
  3663  
  3664  func (l *errorListener) Addr() net.Addr {
  3665  	return dummyAddr("test-address")
  3666  }
  3667  
  3668  func TestAcceptMaxFds(t *testing.T) {
  3669  	setParallel(t)
  3670  
  3671  	ln := &errorListener{[]error{
  3672  		&net.OpError{
  3673  			Op:  "accept",
  3674  			Err: syscall.EMFILE,
  3675  		}}}
  3676  	server := &Server{
  3677  		Handler:  HandlerFunc(HandlerFunc(func(ResponseWriter, *Request) {})),
  3678  		ErrorLog: log.New(io.Discard, "", 0), // noisy otherwise
  3679  	}
  3680  	err := server.Serve(ln)
  3681  	if err != io.EOF {
  3682  		t.Errorf("got error %v, want EOF", err)
  3683  	}
  3684  }
  3685  
  3686  func TestWriteAfterHijack(t *testing.T) {
  3687  	req := reqBytes("GET / HTTP/1.1\nHost: golang.org")
  3688  	var buf strings.Builder
  3689  	wrotec := make(chan bool, 1)
  3690  	conn := &rwTestConn{
  3691  		Reader: bytes.NewReader(req),
  3692  		Writer: &buf,
  3693  		closec: make(chan bool, 1),
  3694  	}
  3695  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  3696  		conn, bufrw, err := rw.(Hijacker).Hijack()
  3697  		if err != nil {
  3698  			t.Error(err)
  3699  			return
  3700  		}
  3701  		go func() {
  3702  			bufrw.Write([]byte("[hijack-to-bufw]"))
  3703  			bufrw.Flush()
  3704  			conn.Write([]byte("[hijack-to-conn]"))
  3705  			conn.Close()
  3706  			wrotec <- true
  3707  		}()
  3708  	})
  3709  	ln := &oneConnListener{conn: conn}
  3710  	go Serve(ln, handler)
  3711  	<-conn.closec
  3712  	<-wrotec
  3713  	if g, w := buf.String(), "[hijack-to-bufw][hijack-to-conn]"; g != w {
  3714  		t.Errorf("wrote %q; want %q", g, w)
  3715  	}
  3716  }
  3717  
  3718  func TestDoubleHijack(t *testing.T) {
  3719  	req := reqBytes("GET / HTTP/1.1\nHost: golang.org")
  3720  	var buf bytes.Buffer
  3721  	conn := &rwTestConn{
  3722  		Reader: bytes.NewReader(req),
  3723  		Writer: &buf,
  3724  		closec: make(chan bool, 1),
  3725  	}
  3726  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  3727  		conn, _, err := rw.(Hijacker).Hijack()
  3728  		if err != nil {
  3729  			t.Error(err)
  3730  			return
  3731  		}
  3732  		_, _, err = rw.(Hijacker).Hijack()
  3733  		if err == nil {
  3734  			t.Errorf("got err = nil;  want err != nil")
  3735  		}
  3736  		conn.Close()
  3737  	})
  3738  	ln := &oneConnListener{conn: conn}
  3739  	go Serve(ln, handler)
  3740  	<-conn.closec
  3741  }
  3742  
  3743  // https://golang.org/issue/5955
  3744  // Note that this does not test the "request too large"
  3745  // exit path from the http server. This is intentional;
  3746  // not sending Connection: close is just a minor wire
  3747  // optimization and is pointless if dealing with a
  3748  // badly behaved client.
  3749  func TestHTTP10ConnectionHeader(t *testing.T) {
  3750  	run(t, testHTTP10ConnectionHeader, []testMode{http1Mode})
  3751  }
  3752  func testHTTP10ConnectionHeader(t *testing.T, mode testMode) {
  3753  	mux := NewServeMux()
  3754  	mux.Handle("/", HandlerFunc(func(ResponseWriter, *Request) {}))
  3755  	ts := newClientServerTest(t, mode, mux).ts
  3756  
  3757  	// net/http uses HTTP/1.1 for requests, so write requests manually
  3758  	tests := []struct {
  3759  		req    string   // raw http request
  3760  		expect []string // expected Connection header(s)
  3761  	}{
  3762  		{
  3763  			req:    "GET / HTTP/1.0\r\n\r\n",
  3764  			expect: nil,
  3765  		},
  3766  		{
  3767  			req:    "OPTIONS * HTTP/1.0\r\n\r\n",
  3768  			expect: nil,
  3769  		},
  3770  		{
  3771  			req:    "GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n",
  3772  			expect: []string{"keep-alive"},
  3773  		},
  3774  	}
  3775  
  3776  	for _, tt := range tests {
  3777  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  3778  		if err != nil {
  3779  			t.Fatal("dial err:", err)
  3780  		}
  3781  
  3782  		_, err = fmt.Fprint(conn, tt.req)
  3783  		if err != nil {
  3784  			t.Fatal("conn write err:", err)
  3785  		}
  3786  
  3787  		resp, err := ReadResponse(bufio.NewReader(conn), &Request{Method: "GET"})
  3788  		if err != nil {
  3789  			t.Fatal("ReadResponse err:", err)
  3790  		}
  3791  		conn.Close()
  3792  		resp.Body.Close()
  3793  
  3794  		got := resp.Header["Connection"]
  3795  		if !reflect.DeepEqual(got, tt.expect) {
  3796  			t.Errorf("wrong Connection headers for request %q. Got %q expect %q", tt.req, got, tt.expect)
  3797  		}
  3798  	}
  3799  }
  3800  
  3801  // See golang.org/issue/5660
  3802  func TestServerReaderFromOrder(t *testing.T) { run(t, testServerReaderFromOrder) }
  3803  func testServerReaderFromOrder(t *testing.T, mode testMode) {
  3804  	pr, pw := io.Pipe()
  3805  	const size = 3 << 20
  3806  	cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3807  		rw.Header().Set("Content-Type", "text/plain") // prevent sniffing path
  3808  		done := make(chan bool)
  3809  		go func() {
  3810  			io.Copy(rw, pr)
  3811  			close(done)
  3812  		}()
  3813  		time.Sleep(25 * time.Millisecond) // give Copy a chance to break things
  3814  		n, err := io.Copy(io.Discard, req.Body)
  3815  		if err != nil {
  3816  			t.Errorf("handler Copy: %v", err)
  3817  			return
  3818  		}
  3819  		if n != size {
  3820  			t.Errorf("handler Copy = %d; want %d", n, size)
  3821  		}
  3822  		pw.Write([]byte("hi"))
  3823  		pw.Close()
  3824  		<-done
  3825  	}))
  3826  
  3827  	req, err := NewRequest("POST", cst.ts.URL, io.LimitReader(neverEnding('a'), size))
  3828  	if err != nil {
  3829  		t.Fatal(err)
  3830  	}
  3831  	res, err := cst.c.Do(req)
  3832  	if err != nil {
  3833  		t.Fatal(err)
  3834  	}
  3835  	all, err := io.ReadAll(res.Body)
  3836  	if err != nil {
  3837  		t.Fatal(err)
  3838  	}
  3839  	res.Body.Close()
  3840  	if string(all) != "hi" {
  3841  		t.Errorf("Body = %q; want hi", all)
  3842  	}
  3843  }
  3844  
  3845  // Issue 6157, Issue 6685
  3846  func TestCodesPreventingContentTypeAndBody(t *testing.T) {
  3847  	for _, code := range []int{StatusNotModified, StatusNoContent} {
  3848  		ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  3849  			if r.URL.Path == "/header" {
  3850  				w.Header().Set("Content-Length", "123")
  3851  			}
  3852  			w.WriteHeader(code)
  3853  			if r.URL.Path == "/more" {
  3854  				w.Write([]byte("stuff"))
  3855  			}
  3856  		}))
  3857  		for _, req := range []string{
  3858  			"GET / HTTP/1.0",
  3859  			"GET /header HTTP/1.0",
  3860  			"GET /more HTTP/1.0",
  3861  			"GET / HTTP/1.1\nHost: foo",
  3862  			"GET /header HTTP/1.1\nHost: foo",
  3863  			"GET /more HTTP/1.1\nHost: foo",
  3864  		} {
  3865  			got := ht.rawResponse(req)
  3866  			wantStatus := fmt.Sprintf("%d %s", code, StatusText(code))
  3867  			if !strings.Contains(got, wantStatus) {
  3868  				t.Errorf("Code %d: Wanted %q Modified for %q: %s", code, wantStatus, req, got)
  3869  			} else if strings.Contains(got, "Content-Length") {
  3870  				t.Errorf("Code %d: Got a Content-Length from %q: %s", code, req, got)
  3871  			} else if strings.Contains(got, "stuff") {
  3872  				t.Errorf("Code %d: Response contains a body from %q: %s", code, req, got)
  3873  			}
  3874  		}
  3875  	}
  3876  }
  3877  
  3878  func TestContentTypeOkayOn204(t *testing.T) {
  3879  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  3880  		w.Header().Set("Content-Length", "123") // suppressed
  3881  		w.Header().Set("Content-Type", "foo/bar")
  3882  		w.WriteHeader(204)
  3883  	}))
  3884  	got := ht.rawResponse("GET / HTTP/1.1\nHost: foo")
  3885  	if !strings.Contains(got, "Content-Type: foo/bar") {
  3886  		t.Errorf("Response = %q; want Content-Type: foo/bar", got)
  3887  	}
  3888  	if strings.Contains(got, "Content-Length: 123") {
  3889  		t.Errorf("Response = %q; don't want a Content-Length", got)
  3890  	}
  3891  }
  3892  
  3893  // Issue 6995
  3894  // A server Handler can receive a Request, and then turn around and
  3895  // give a copy of that Request.Body out to the Transport (e.g. any
  3896  // proxy).  So then two people own that Request.Body (both the server
  3897  // and the http client), and both think they can close it on failure.
  3898  // Therefore, all incoming server requests Bodies need to be thread-safe.
  3899  func TestTransportAndServerSharedBodyRace(t *testing.T) {
  3900  	run(t, testTransportAndServerSharedBodyRace)
  3901  }
  3902  func testTransportAndServerSharedBodyRace(t *testing.T, mode testMode) {
  3903  	const bodySize = 1 << 20
  3904  
  3905  	// errorf is like t.Errorf, but also writes to println. When
  3906  	// this test fails, it hangs. This helps debugging and I've
  3907  	// added this enough times "temporarily".  It now gets added
  3908  	// full time.
  3909  	errorf := func(format string, args ...any) {
  3910  		v := fmt.Sprintf(format, args...)
  3911  		println(v)
  3912  		t.Error(v)
  3913  	}
  3914  
  3915  	unblockBackend := make(chan bool)
  3916  	backend := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3917  		gone := rw.(CloseNotifier).CloseNotify()
  3918  		didCopy := make(chan any)
  3919  		go func() {
  3920  			n, err := io.CopyN(rw, req.Body, bodySize)
  3921  			didCopy <- []any{n, err}
  3922  		}()
  3923  		isGone := false
  3924  	Loop:
  3925  		for {
  3926  			select {
  3927  			case <-didCopy:
  3928  				break Loop
  3929  			case <-gone:
  3930  				isGone = true
  3931  			case <-time.After(time.Second):
  3932  				println("1 second passes in backend, proxygone=", isGone)
  3933  			}
  3934  		}
  3935  		<-unblockBackend
  3936  	}))
  3937  	defer backend.close()
  3938  
  3939  	backendRespc := make(chan *Response, 1)
  3940  	var proxy *clientServerTest
  3941  	proxy = newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  3942  		req2, _ := NewRequest("POST", backend.ts.URL, req.Body)
  3943  		req2.ContentLength = bodySize
  3944  		cancel := make(chan struct{})
  3945  		req2.Cancel = cancel
  3946  
  3947  		bresp, err := proxy.c.Do(req2)
  3948  		if err != nil {
  3949  			errorf("Proxy outbound request: %v", err)
  3950  			return
  3951  		}
  3952  		_, err = io.CopyN(io.Discard, bresp.Body, bodySize/2)
  3953  		if err != nil {
  3954  			errorf("Proxy copy error: %v", err)
  3955  			return
  3956  		}
  3957  		backendRespc <- bresp // to close later
  3958  
  3959  		// Try to cause a race: Both the Transport and the proxy handler's Server
  3960  		// will try to read/close req.Body (aka req2.Body)
  3961  		if mode == http2Mode {
  3962  			close(cancel)
  3963  		} else {
  3964  			proxy.c.Transport.(*Transport).CancelRequest(req2)
  3965  		}
  3966  		rw.Write([]byte("OK"))
  3967  	}))
  3968  	defer proxy.close()
  3969  
  3970  	defer close(unblockBackend)
  3971  	req, _ := NewRequest("POST", proxy.ts.URL, io.LimitReader(neverEnding('a'), bodySize))
  3972  	res, err := proxy.c.Do(req)
  3973  	if err != nil {
  3974  		t.Fatalf("Original request: %v", err)
  3975  	}
  3976  
  3977  	// Cleanup, so we don't leak goroutines.
  3978  	res.Body.Close()
  3979  	select {
  3980  	case res := <-backendRespc:
  3981  		res.Body.Close()
  3982  	default:
  3983  		// We failed earlier. (e.g. on proxy.c.Do(req2))
  3984  	}
  3985  }
  3986  
  3987  // Test that a hanging Request.Body.Read from another goroutine can't
  3988  // cause the Handler goroutine's Request.Body.Close to block.
  3989  // See issue 7121.
  3990  func TestRequestBodyCloseDoesntBlock(t *testing.T) {
  3991  	run(t, testRequestBodyCloseDoesntBlock, []testMode{http1Mode})
  3992  }
  3993  func testRequestBodyCloseDoesntBlock(t *testing.T, mode testMode) {
  3994  	if testing.Short() {
  3995  		t.Skip("skipping in -short mode")
  3996  	}
  3997  
  3998  	readErrCh := make(chan error, 1)
  3999  	errCh := make(chan error, 2)
  4000  
  4001  	server := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4002  		go func(body io.Reader) {
  4003  			_, err := body.Read(make([]byte, 100))
  4004  			readErrCh <- err
  4005  		}(req.Body)
  4006  		time.Sleep(500 * time.Millisecond)
  4007  	})).ts
  4008  
  4009  	closeConn := make(chan bool)
  4010  	defer close(closeConn)
  4011  	go func() {
  4012  		conn, err := net.Dial("tcp", server.Listener.Addr().String())
  4013  		if err != nil {
  4014  			errCh <- err
  4015  			return
  4016  		}
  4017  		defer conn.Close()
  4018  		_, err = conn.Write([]byte("POST / HTTP/1.1\r\nConnection: close\r\nHost: foo\r\nContent-Length: 100000\r\n\r\n"))
  4019  		if err != nil {
  4020  			errCh <- err
  4021  			return
  4022  		}
  4023  		// And now just block, making the server block on our
  4024  		// 100000 bytes of body that will never arrive.
  4025  		<-closeConn
  4026  	}()
  4027  	select {
  4028  	case err := <-readErrCh:
  4029  		if err == nil {
  4030  			t.Error("Read was nil. Expected error.")
  4031  		}
  4032  	case err := <-errCh:
  4033  		t.Error(err)
  4034  	}
  4035  }
  4036  
  4037  // test that ResponseWriter implements io.StringWriter.
  4038  func TestResponseWriterWriteString(t *testing.T) {
  4039  	okc := make(chan bool, 1)
  4040  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  4041  		_, ok := w.(io.StringWriter)
  4042  		okc <- ok
  4043  	}))
  4044  	ht.rawResponse("GET / HTTP/1.0")
  4045  	select {
  4046  	case ok := <-okc:
  4047  		if !ok {
  4048  			t.Error("ResponseWriter did not implement io.StringWriter")
  4049  		}
  4050  	default:
  4051  		t.Error("handler was never called")
  4052  	}
  4053  }
  4054  
  4055  func TestAppendTime(t *testing.T) {
  4056  	var b [len(TimeFormat)]byte
  4057  	t1 := time.Date(2013, 9, 21, 15, 41, 0, 0, time.FixedZone("CEST", 2*60*60))
  4058  	res := ExportAppendTime(b[:0], t1)
  4059  	t2, err := ParseTime(string(res))
  4060  	if err != nil {
  4061  		t.Fatalf("Error parsing time: %s", err)
  4062  	}
  4063  	if !t1.Equal(t2) {
  4064  		t.Fatalf("Times differ; expected: %v, got %v (%s)", t1, t2, string(res))
  4065  	}
  4066  }
  4067  
  4068  func TestServerConnState(t *testing.T) { run(t, testServerConnState, []testMode{http1Mode}) }
  4069  func testServerConnState(t *testing.T, mode testMode) {
  4070  	handler := map[string]func(w ResponseWriter, r *Request){
  4071  		"/": func(w ResponseWriter, r *Request) {
  4072  			fmt.Fprintf(w, "Hello.")
  4073  		},
  4074  		"/close": func(w ResponseWriter, r *Request) {
  4075  			w.Header().Set("Connection", "close")
  4076  			fmt.Fprintf(w, "Hello.")
  4077  		},
  4078  		"/hijack": func(w ResponseWriter, r *Request) {
  4079  			c, _, _ := w.(Hijacker).Hijack()
  4080  			c.Write([]byte("HTTP/1.0 200 OK\r\nConnection: close\r\n\r\nHello."))
  4081  			c.Close()
  4082  		},
  4083  		"/hijack-panic": func(w ResponseWriter, r *Request) {
  4084  			c, _, _ := w.(Hijacker).Hijack()
  4085  			c.Write([]byte("HTTP/1.0 200 OK\r\nConnection: close\r\n\r\nHello."))
  4086  			c.Close()
  4087  			panic("intentional panic")
  4088  		},
  4089  	}
  4090  
  4091  	// A stateLog is a log of states over the lifetime of a connection.
  4092  	type stateLog struct {
  4093  		active   net.Conn // The connection for which the log is recorded; set to the first connection seen in StateNew.
  4094  		got      []ConnState
  4095  		want     []ConnState
  4096  		complete chan<- struct{} // If non-nil, closed when either 'got' is equal to 'want', or 'got' is no longer a prefix of 'want'.
  4097  	}
  4098  	activeLog := make(chan *stateLog, 1)
  4099  
  4100  	// wantLog invokes doRequests, then waits for the resulting connection to
  4101  	// either pass through the sequence of states in want or enter a state outside
  4102  	// of that sequence.
  4103  	wantLog := func(doRequests func(), want ...ConnState) {
  4104  		t.Helper()
  4105  		complete := make(chan struct{})
  4106  		activeLog <- &stateLog{want: want, complete: complete}
  4107  
  4108  		doRequests()
  4109  
  4110  		<-complete
  4111  		sl := <-activeLog
  4112  		if !reflect.DeepEqual(sl.got, sl.want) {
  4113  			t.Errorf("Request(s) produced unexpected state sequence.\nGot:  %v\nWant: %v", sl.got, sl.want)
  4114  		}
  4115  		// Don't return sl to activeLog: we don't expect any further states after
  4116  		// this point, and want to keep the ConnState callback blocked until the
  4117  		// next call to wantLog.
  4118  	}
  4119  
  4120  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4121  		handler[r.URL.Path](w, r)
  4122  	}), func(ts *httptest.Server) {
  4123  		ts.Config.ErrorLog = log.New(io.Discard, "", 0)
  4124  		ts.Config.ConnState = func(c net.Conn, state ConnState) {
  4125  			if c == nil {
  4126  				t.Errorf("nil conn seen in state %s", state)
  4127  				return
  4128  			}
  4129  			sl := <-activeLog
  4130  			if sl.active == nil && state == StateNew {
  4131  				sl.active = c
  4132  			} else if sl.active != c {
  4133  				t.Errorf("unexpected conn in state %s", state)
  4134  				activeLog <- sl
  4135  				return
  4136  			}
  4137  			sl.got = append(sl.got, state)
  4138  			if sl.complete != nil && (len(sl.got) >= len(sl.want) || !reflect.DeepEqual(sl.got, sl.want[:len(sl.got)])) {
  4139  				close(sl.complete)
  4140  				sl.complete = nil
  4141  			}
  4142  			activeLog <- sl
  4143  		}
  4144  	}).ts
  4145  	defer func() {
  4146  		activeLog <- &stateLog{} // If the test failed, allow any remaining ConnState callbacks to complete.
  4147  		ts.Close()
  4148  	}()
  4149  
  4150  	c := ts.Client()
  4151  
  4152  	mustGet := func(url string, headers ...string) {
  4153  		t.Helper()
  4154  		req, err := NewRequest("GET", url, nil)
  4155  		if err != nil {
  4156  			t.Fatal(err)
  4157  		}
  4158  		for len(headers) > 0 {
  4159  			req.Header.Add(headers[0], headers[1])
  4160  			headers = headers[2:]
  4161  		}
  4162  		res, err := c.Do(req)
  4163  		if err != nil {
  4164  			t.Errorf("Error fetching %s: %v", url, err)
  4165  			return
  4166  		}
  4167  		_, err = io.ReadAll(res.Body)
  4168  		defer res.Body.Close()
  4169  		if err != nil {
  4170  			t.Errorf("Error reading %s: %v", url, err)
  4171  		}
  4172  	}
  4173  
  4174  	wantLog(func() {
  4175  		mustGet(ts.URL + "/")
  4176  		mustGet(ts.URL + "/close")
  4177  	}, StateNew, StateActive, StateIdle, StateActive, StateClosed)
  4178  
  4179  	wantLog(func() {
  4180  		mustGet(ts.URL + "/")
  4181  		mustGet(ts.URL+"/", "Connection", "close")
  4182  	}, StateNew, StateActive, StateIdle, StateActive, StateClosed)
  4183  
  4184  	wantLog(func() {
  4185  		mustGet(ts.URL + "/hijack")
  4186  	}, StateNew, StateActive, StateHijacked)
  4187  
  4188  	wantLog(func() {
  4189  		mustGet(ts.URL + "/hijack-panic")
  4190  	}, StateNew, StateActive, StateHijacked)
  4191  
  4192  	wantLog(func() {
  4193  		c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4194  		if err != nil {
  4195  			t.Fatal(err)
  4196  		}
  4197  		c.Close()
  4198  	}, StateNew, StateClosed)
  4199  
  4200  	wantLog(func() {
  4201  		c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4202  		if err != nil {
  4203  			t.Fatal(err)
  4204  		}
  4205  		if _, err := io.WriteString(c, "BOGUS REQUEST\r\n\r\n"); err != nil {
  4206  			t.Fatal(err)
  4207  		}
  4208  		c.Read(make([]byte, 1)) // block until server hangs up on us
  4209  		c.Close()
  4210  	}, StateNew, StateActive, StateClosed)
  4211  
  4212  	wantLog(func() {
  4213  		c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4214  		if err != nil {
  4215  			t.Fatal(err)
  4216  		}
  4217  		if _, err := io.WriteString(c, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n"); err != nil {
  4218  			t.Fatal(err)
  4219  		}
  4220  		res, err := ReadResponse(bufio.NewReader(c), nil)
  4221  		if err != nil {
  4222  			t.Fatal(err)
  4223  		}
  4224  		if _, err := io.Copy(io.Discard, res.Body); err != nil {
  4225  			t.Fatal(err)
  4226  		}
  4227  		c.Close()
  4228  	}, StateNew, StateActive, StateIdle, StateClosed)
  4229  }
  4230  
  4231  func TestServerKeepAlivesEnabledResultClose(t *testing.T) {
  4232  	run(t, testServerKeepAlivesEnabledResultClose, []testMode{http1Mode})
  4233  }
  4234  func testServerKeepAlivesEnabledResultClose(t *testing.T, mode testMode) {
  4235  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4236  	}), func(ts *httptest.Server) {
  4237  		ts.Config.SetKeepAlivesEnabled(false)
  4238  	}).ts
  4239  	res, err := ts.Client().Get(ts.URL)
  4240  	if err != nil {
  4241  		t.Fatal(err)
  4242  	}
  4243  	defer res.Body.Close()
  4244  	if !res.Close {
  4245  		t.Errorf("Body.Close == false; want true")
  4246  	}
  4247  }
  4248  
  4249  // golang.org/issue/7856
  4250  func TestServerEmptyBodyRace(t *testing.T) { run(t, testServerEmptyBodyRace) }
  4251  func testServerEmptyBodyRace(t *testing.T, mode testMode) {
  4252  	var n int32
  4253  	cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4254  		atomic.AddInt32(&n, 1)
  4255  	}), optQuietLog)
  4256  	var wg sync.WaitGroup
  4257  	const reqs = 20
  4258  	for i := 0; i < reqs; i++ {
  4259  		wg.Add(1)
  4260  		go func() {
  4261  			defer wg.Done()
  4262  			res, err := cst.c.Get(cst.ts.URL)
  4263  			if err != nil {
  4264  				// Try to deflake spurious "connection reset by peer" under load.
  4265  				// See golang.org/issue/22540.
  4266  				time.Sleep(10 * time.Millisecond)
  4267  				res, err = cst.c.Get(cst.ts.URL)
  4268  				if err != nil {
  4269  					t.Error(err)
  4270  					return
  4271  				}
  4272  			}
  4273  			defer res.Body.Close()
  4274  			_, err = io.Copy(io.Discard, res.Body)
  4275  			if err != nil {
  4276  				t.Error(err)
  4277  				return
  4278  			}
  4279  		}()
  4280  	}
  4281  	wg.Wait()
  4282  	if got := atomic.LoadInt32(&n); got != reqs {
  4283  		t.Errorf("handler ran %d times; want %d", got, reqs)
  4284  	}
  4285  }
  4286  
  4287  func TestServerConnStateNew(t *testing.T) {
  4288  	sawNew := false // if the test is buggy, we'll race on this variable.
  4289  	srv := &Server{
  4290  		ConnState: func(c net.Conn, state ConnState) {
  4291  			if state == StateNew {
  4292  				sawNew = true // testing that this write isn't racy
  4293  			}
  4294  		},
  4295  		Handler: HandlerFunc(func(w ResponseWriter, r *Request) {}), // irrelevant
  4296  	}
  4297  	srv.Serve(&oneConnListener{
  4298  		conn: &rwTestConn{
  4299  			Reader: strings.NewReader("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"),
  4300  			Writer: io.Discard,
  4301  		},
  4302  	})
  4303  	if !sawNew { // testing that this read isn't racy
  4304  		t.Error("StateNew not seen")
  4305  	}
  4306  }
  4307  
  4308  type closeWriteTestConn struct {
  4309  	rwTestConn
  4310  	didCloseWrite bool
  4311  }
  4312  
  4313  func (c *closeWriteTestConn) CloseWrite() error {
  4314  	c.didCloseWrite = true
  4315  	return nil
  4316  }
  4317  
  4318  func TestCloseWrite(t *testing.T) {
  4319  	setParallel(t)
  4320  	var srv Server
  4321  	var testConn closeWriteTestConn
  4322  	c := ExportServerNewConn(&srv, &testConn)
  4323  	ExportCloseWriteAndWait(c)
  4324  	if !testConn.didCloseWrite {
  4325  		t.Error("didn't see CloseWrite call")
  4326  	}
  4327  }
  4328  
  4329  // This verifies that a handler can Flush and then Hijack.
  4330  //
  4331  // A similar test crashed once during development, but it was only
  4332  // testing this tangentially and temporarily until another TODO was
  4333  // fixed.
  4334  //
  4335  // So add an explicit test for this.
  4336  func TestServerFlushAndHijack(t *testing.T) { run(t, testServerFlushAndHijack, []testMode{http1Mode}) }
  4337  func testServerFlushAndHijack(t *testing.T, mode testMode) {
  4338  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4339  		io.WriteString(w, "Hello, ")
  4340  		w.(Flusher).Flush()
  4341  		conn, buf, _ := w.(Hijacker).Hijack()
  4342  		buf.WriteString("6\r\nworld!\r\n0\r\n\r\n")
  4343  		if err := buf.Flush(); err != nil {
  4344  			t.Error(err)
  4345  		}
  4346  		if err := conn.Close(); err != nil {
  4347  			t.Error(err)
  4348  		}
  4349  	})).ts
  4350  	res, err := Get(ts.URL)
  4351  	if err != nil {
  4352  		t.Fatal(err)
  4353  	}
  4354  	defer res.Body.Close()
  4355  	all, err := io.ReadAll(res.Body)
  4356  	if err != nil {
  4357  		t.Fatal(err)
  4358  	}
  4359  	if want := "Hello, world!"; string(all) != want {
  4360  		t.Errorf("Got %q; want %q", all, want)
  4361  	}
  4362  }
  4363  
  4364  // golang.org/issue/8534 -- the Server shouldn't reuse a connection
  4365  // for keep-alive after it's seen any Write error (e.g. a timeout) on
  4366  // that net.Conn.
  4367  //
  4368  // To test, verify we don't timeout or see fewer unique client
  4369  // addresses (== unique connections) than requests.
  4370  func TestServerKeepAliveAfterWriteError(t *testing.T) {
  4371  	run(t, testServerKeepAliveAfterWriteError, []testMode{http1Mode})
  4372  }
  4373  func testServerKeepAliveAfterWriteError(t *testing.T, mode testMode) {
  4374  	if testing.Short() {
  4375  		t.Skip("skipping in -short mode")
  4376  	}
  4377  	const numReq = 3
  4378  	addrc := make(chan string, numReq)
  4379  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4380  		addrc <- r.RemoteAddr
  4381  		time.Sleep(500 * time.Millisecond)
  4382  		w.(Flusher).Flush()
  4383  	}), func(ts *httptest.Server) {
  4384  		ts.Config.WriteTimeout = 250 * time.Millisecond
  4385  	}).ts
  4386  
  4387  	errc := make(chan error, numReq)
  4388  	go func() {
  4389  		defer close(errc)
  4390  		for i := 0; i < numReq; i++ {
  4391  			res, err := Get(ts.URL)
  4392  			if res != nil {
  4393  				res.Body.Close()
  4394  			}
  4395  			errc <- err
  4396  		}
  4397  	}()
  4398  
  4399  	addrSeen := map[string]bool{}
  4400  	numOkay := 0
  4401  	for {
  4402  		select {
  4403  		case v := <-addrc:
  4404  			addrSeen[v] = true
  4405  		case err, ok := <-errc:
  4406  			if !ok {
  4407  				if len(addrSeen) != numReq {
  4408  					t.Errorf("saw %d unique client addresses; want %d", len(addrSeen), numReq)
  4409  				}
  4410  				if numOkay != 0 {
  4411  					t.Errorf("got %d successful client requests; want 0", numOkay)
  4412  				}
  4413  				return
  4414  			}
  4415  			if err == nil {
  4416  				numOkay++
  4417  			}
  4418  		}
  4419  	}
  4420  }
  4421  
  4422  // Issue 9987: shouldn't add automatic Content-Length (or
  4423  // Content-Type) if a Transfer-Encoding was set by the handler.
  4424  func TestNoContentLengthIfTransferEncoding(t *testing.T) {
  4425  	run(t, testNoContentLengthIfTransferEncoding, []testMode{http1Mode})
  4426  }
  4427  func testNoContentLengthIfTransferEncoding(t *testing.T, mode testMode) {
  4428  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4429  		w.Header().Set("Transfer-Encoding", "foo")
  4430  		io.WriteString(w, "<html>")
  4431  	})).ts
  4432  	c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4433  	if err != nil {
  4434  		t.Fatalf("Dial: %v", err)
  4435  	}
  4436  	defer c.Close()
  4437  	if _, err := io.WriteString(c, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n"); err != nil {
  4438  		t.Fatal(err)
  4439  	}
  4440  	bs := bufio.NewScanner(c)
  4441  	var got strings.Builder
  4442  	for bs.Scan() {
  4443  		if strings.TrimSpace(bs.Text()) == "" {
  4444  			break
  4445  		}
  4446  		got.WriteString(bs.Text())
  4447  		got.WriteByte('\n')
  4448  	}
  4449  	if err := bs.Err(); err != nil {
  4450  		t.Fatal(err)
  4451  	}
  4452  	if strings.Contains(got.String(), "Content-Length") {
  4453  		t.Errorf("Unexpected Content-Length in response headers: %s", got.String())
  4454  	}
  4455  	if strings.Contains(got.String(), "Content-Type") {
  4456  		t.Errorf("Unexpected Content-Type in response headers: %s", got.String())
  4457  	}
  4458  }
  4459  
  4460  // tolerate extra CRLF(s) before Request-Line on subsequent requests on a conn
  4461  // Issue 10876.
  4462  func TestTolerateCRLFBeforeRequestLine(t *testing.T) {
  4463  	req := []byte("POST / HTTP/1.1\r\nHost: golang.org\r\nContent-Length: 3\r\n\r\nABC" +
  4464  		"\r\n\r\n" + // <-- this stuff is bogus, but we'll ignore it
  4465  		"GET / HTTP/1.1\r\nHost: golang.org\r\n\r\n")
  4466  	var buf bytes.Buffer
  4467  	conn := &rwTestConn{
  4468  		Reader: bytes.NewReader(req),
  4469  		Writer: &buf,
  4470  		closec: make(chan bool, 1),
  4471  	}
  4472  	ln := &oneConnListener{conn: conn}
  4473  	numReq := 0
  4474  	go Serve(ln, HandlerFunc(func(rw ResponseWriter, r *Request) {
  4475  		numReq++
  4476  	}))
  4477  	<-conn.closec
  4478  	if numReq != 2 {
  4479  		t.Errorf("num requests = %d; want 2", numReq)
  4480  		t.Logf("Res: %s", buf.Bytes())
  4481  	}
  4482  }
  4483  
  4484  func TestIssue13893_Expect100(t *testing.T) {
  4485  	// test that the Server doesn't filter out Expect headers.
  4486  	req := reqBytes(`PUT /readbody HTTP/1.1
  4487  User-Agent: PycURL/7.22.0
  4488  Host: 127.0.0.1:9000
  4489  Accept: */*
  4490  Expect: 100-continue
  4491  Content-Length: 10
  4492  
  4493  HelloWorld
  4494  
  4495  `)
  4496  	var buf bytes.Buffer
  4497  	conn := &rwTestConn{
  4498  		Reader: bytes.NewReader(req),
  4499  		Writer: &buf,
  4500  		closec: make(chan bool, 1),
  4501  	}
  4502  	ln := &oneConnListener{conn: conn}
  4503  	go Serve(ln, HandlerFunc(func(w ResponseWriter, r *Request) {
  4504  		if _, ok := r.Header["Expect"]; !ok {
  4505  			t.Error("Expect header should not be filtered out")
  4506  		}
  4507  	}))
  4508  	<-conn.closec
  4509  }
  4510  
  4511  func TestIssue11549_Expect100(t *testing.T) {
  4512  	req := reqBytes(`PUT /readbody HTTP/1.1
  4513  User-Agent: PycURL/7.22.0
  4514  Host: 127.0.0.1:9000
  4515  Accept: */*
  4516  Expect: 100-continue
  4517  Content-Length: 10
  4518  
  4519  HelloWorldPUT /noreadbody HTTP/1.1
  4520  User-Agent: PycURL/7.22.0
  4521  Host: 127.0.0.1:9000
  4522  Accept: */*
  4523  Expect: 100-continue
  4524  Content-Length: 10
  4525  
  4526  GET /should-be-ignored HTTP/1.1
  4527  Host: foo
  4528  
  4529  `)
  4530  	var buf strings.Builder
  4531  	conn := &rwTestConn{
  4532  		Reader: bytes.NewReader(req),
  4533  		Writer: &buf,
  4534  		closec: make(chan bool, 1),
  4535  	}
  4536  	ln := &oneConnListener{conn: conn}
  4537  	numReq := 0
  4538  	go Serve(ln, HandlerFunc(func(w ResponseWriter, r *Request) {
  4539  		numReq++
  4540  		if r.URL.Path == "/readbody" {
  4541  			io.ReadAll(r.Body)
  4542  		}
  4543  		io.WriteString(w, "Hello world!")
  4544  	}))
  4545  	<-conn.closec
  4546  	if numReq != 2 {
  4547  		t.Errorf("num requests = %d; want 2", numReq)
  4548  	}
  4549  	if !strings.Contains(buf.String(), "Connection: close\r\n") {
  4550  		t.Errorf("expected 'Connection: close' in response; got: %s", buf.String())
  4551  	}
  4552  }
  4553  
  4554  // If a Handler finishes and there's an unread request body,
  4555  // verify the server try to do implicit read on it before replying.
  4556  func TestHandlerFinishSkipBigContentLengthRead(t *testing.T) {
  4557  	setParallel(t)
  4558  	conn := &testConn{closec: make(chan bool)}
  4559  	conn.readBuf.Write([]byte(fmt.Sprintf(
  4560  		"POST / HTTP/1.1\r\n" +
  4561  			"Host: test\r\n" +
  4562  			"Content-Length: 9999999999\r\n" +
  4563  			"\r\n" + strings.Repeat("a", 1<<20))))
  4564  
  4565  	ls := &oneConnListener{conn}
  4566  	var inHandlerLen int
  4567  	go Serve(ls, HandlerFunc(func(rw ResponseWriter, req *Request) {
  4568  		inHandlerLen = conn.readBuf.Len()
  4569  		rw.WriteHeader(404)
  4570  	}))
  4571  	<-conn.closec
  4572  	afterHandlerLen := conn.readBuf.Len()
  4573  
  4574  	if afterHandlerLen != inHandlerLen {
  4575  		t.Errorf("unexpected implicit read. Read buffer went from %d -> %d", inHandlerLen, afterHandlerLen)
  4576  	}
  4577  }
  4578  
  4579  func TestHandlerSetsBodyNil(t *testing.T) { run(t, testHandlerSetsBodyNil) }
  4580  func testHandlerSetsBodyNil(t *testing.T, mode testMode) {
  4581  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4582  		r.Body = nil
  4583  		fmt.Fprintf(w, "%v", r.RemoteAddr)
  4584  	}))
  4585  	get := func() string {
  4586  		res, err := cst.c.Get(cst.ts.URL)
  4587  		if err != nil {
  4588  			t.Fatal(err)
  4589  		}
  4590  		defer res.Body.Close()
  4591  		slurp, err := io.ReadAll(res.Body)
  4592  		if err != nil {
  4593  			t.Fatal(err)
  4594  		}
  4595  		return string(slurp)
  4596  	}
  4597  	a, b := get(), get()
  4598  	if a != b {
  4599  		t.Errorf("Failed to reuse connections between requests: %v vs %v", a, b)
  4600  	}
  4601  }
  4602  
  4603  // Test that we validate the Host header.
  4604  // Issue 11206 (invalid bytes in Host) and 13624 (Host present in HTTP/1.1)
  4605  func TestServerValidatesHostHeader(t *testing.T) {
  4606  	tests := []struct {
  4607  		proto string
  4608  		host  string
  4609  		want  int
  4610  	}{
  4611  		{"HTTP/0.9", "", 505},
  4612  
  4613  		{"HTTP/1.1", "", 400},
  4614  		{"HTTP/1.1", "Host: \r\n", 200},
  4615  		{"HTTP/1.1", "Host: 1.2.3.4\r\n", 200},
  4616  		{"HTTP/1.1", "Host: foo.com\r\n", 200},
  4617  		{"HTTP/1.1", "Host: foo-bar_baz.com\r\n", 200},
  4618  		{"HTTP/1.1", "Host: foo.com:80\r\n", 200},
  4619  		{"HTTP/1.1", "Host: ::1\r\n", 200},
  4620  		{"HTTP/1.1", "Host: [::1]\r\n", 200}, // questionable without port, but accept it
  4621  		{"HTTP/1.1", "Host: [::1]:80\r\n", 200},
  4622  		{"HTTP/1.1", "Host: [::1%25en0]:80\r\n", 200},
  4623  		{"HTTP/1.1", "Host: 1.2.3.4\r\n", 200},
  4624  		{"HTTP/1.1", "Host: \x06\r\n", 400},
  4625  		{"HTTP/1.1", "Host: \xff\r\n", 400},
  4626  		{"HTTP/1.1", "Host: {\r\n", 400},
  4627  		{"HTTP/1.1", "Host: }\r\n", 400},
  4628  		{"HTTP/1.1", "Host: first\r\nHost: second\r\n", 400},
  4629  
  4630  		// HTTP/1.0 can lack a host header, but if present
  4631  		// must play by the rules too:
  4632  		{"HTTP/1.0", "", 200},
  4633  		{"HTTP/1.0", "Host: first\r\nHost: second\r\n", 400},
  4634  		{"HTTP/1.0", "Host: \xff\r\n", 400},
  4635  
  4636  		// Make an exception for HTTP upgrade requests:
  4637  		{"PRI * HTTP/2.0", "", 200},
  4638  
  4639  		// Also an exception for CONNECT requests: (Issue 18215)
  4640  		{"CONNECT golang.org:443 HTTP/1.1", "", 200},
  4641  
  4642  		// But not other HTTP/2 stuff:
  4643  		{"PRI / HTTP/2.0", "", 505},
  4644  		{"GET / HTTP/2.0", "", 505},
  4645  		{"GET / HTTP/3.0", "", 505},
  4646  	}
  4647  	for _, tt := range tests {
  4648  		conn := &testConn{closec: make(chan bool, 1)}
  4649  		methodTarget := "GET / "
  4650  		if !strings.HasPrefix(tt.proto, "HTTP/") {
  4651  			methodTarget = ""
  4652  		}
  4653  		io.WriteString(&conn.readBuf, methodTarget+tt.proto+"\r\n"+tt.host+"\r\n")
  4654  
  4655  		ln := &oneConnListener{conn}
  4656  		srv := Server{
  4657  			ErrorLog: quietLog,
  4658  			Handler:  HandlerFunc(func(ResponseWriter, *Request) {}),
  4659  		}
  4660  		go srv.Serve(ln)
  4661  		<-conn.closec
  4662  		res, err := ReadResponse(bufio.NewReader(&conn.writeBuf), nil)
  4663  		if err != nil {
  4664  			t.Errorf("For %s %q, ReadResponse: %v", tt.proto, tt.host, res)
  4665  			continue
  4666  		}
  4667  		if res.StatusCode != tt.want {
  4668  			t.Errorf("For %s %q, Status = %d; want %d", tt.proto, tt.host, res.StatusCode, tt.want)
  4669  		}
  4670  	}
  4671  }
  4672  
  4673  func TestServerHandlersCanHandleH2PRI(t *testing.T) {
  4674  	run(t, testServerHandlersCanHandleH2PRI, []testMode{http1Mode})
  4675  }
  4676  func testServerHandlersCanHandleH2PRI(t *testing.T, mode testMode) {
  4677  	const upgradeResponse = "upgrade here"
  4678  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4679  		conn, br, err := w.(Hijacker).Hijack()
  4680  		if err != nil {
  4681  			t.Error(err)
  4682  			return
  4683  		}
  4684  		defer conn.Close()
  4685  		if r.Method != "PRI" || r.RequestURI != "*" {
  4686  			t.Errorf("Got method/target %q %q; want PRI *", r.Method, r.RequestURI)
  4687  			return
  4688  		}
  4689  		if !r.Close {
  4690  			t.Errorf("Request.Close = true; want false")
  4691  		}
  4692  		const want = "SM\r\n\r\n"
  4693  		buf := make([]byte, len(want))
  4694  		n, err := io.ReadFull(br, buf)
  4695  		if err != nil || string(buf[:n]) != want {
  4696  			t.Errorf("Read = %v, %v (%q), want %q", n, err, buf[:n], want)
  4697  			return
  4698  		}
  4699  		io.WriteString(conn, upgradeResponse)
  4700  	})).ts
  4701  
  4702  	c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4703  	if err != nil {
  4704  		t.Fatalf("Dial: %v", err)
  4705  	}
  4706  	defer c.Close()
  4707  	io.WriteString(c, "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n")
  4708  	slurp, err := io.ReadAll(c)
  4709  	if err != nil {
  4710  		t.Fatal(err)
  4711  	}
  4712  	if string(slurp) != upgradeResponse {
  4713  		t.Errorf("Handler response = %q; want %q", slurp, upgradeResponse)
  4714  	}
  4715  }
  4716  
  4717  // Test that we validate the valid bytes in HTTP/1 headers.
  4718  // Issue 11207.
  4719  func TestServerValidatesHeaders(t *testing.T) {
  4720  	setParallel(t)
  4721  	tests := []struct {
  4722  		header string
  4723  		want   int
  4724  	}{
  4725  		{"", 200},
  4726  		{"Foo: bar\r\n", 200},
  4727  		{"X-Foo: bar\r\n", 200},
  4728  		{"Foo: a space\r\n", 200},
  4729  
  4730  		{"A space: foo\r\n", 400},                            // space in header
  4731  		{"foo\xffbar: foo\r\n", 400},                         // binary in header
  4732  		{"foo\x00bar: foo\r\n", 400},                         // binary in header
  4733  		{"Foo: " + strings.Repeat("x", 1<<21) + "\r\n", 431}, // header too large
  4734  		// Spaces between the header key and colon are not allowed.
  4735  		// See RFC 7230, Section 3.2.4.
  4736  		{"Foo : bar\r\n", 400},
  4737  		{"Foo\t: bar\r\n", 400},
  4738  
  4739  		{"foo: foo foo\r\n", 200},    // LWS space is okay
  4740  		{"foo: foo\tfoo\r\n", 200},   // LWS tab is okay
  4741  		{"foo: foo\x00foo\r\n", 400}, // CTL 0x00 in value is bad
  4742  		{"foo: foo\x7ffoo\r\n", 400}, // CTL 0x7f in value is bad
  4743  		{"foo: foo\xfffoo\r\n", 200}, // non-ASCII high octets in value are fine
  4744  	}
  4745  	for _, tt := range tests {
  4746  		conn := &testConn{closec: make(chan bool, 1)}
  4747  		io.WriteString(&conn.readBuf, "GET / HTTP/1.1\r\nHost: foo\r\n"+tt.header+"\r\n")
  4748  
  4749  		ln := &oneConnListener{conn}
  4750  		srv := Server{
  4751  			ErrorLog: quietLog,
  4752  			Handler:  HandlerFunc(func(ResponseWriter, *Request) {}),
  4753  		}
  4754  		go srv.Serve(ln)
  4755  		<-conn.closec
  4756  		res, err := ReadResponse(bufio.NewReader(&conn.writeBuf), nil)
  4757  		if err != nil {
  4758  			t.Errorf("For %q, ReadResponse: %v", tt.header, res)
  4759  			continue
  4760  		}
  4761  		if res.StatusCode != tt.want {
  4762  			t.Errorf("For %q, Status = %d; want %d", tt.header, res.StatusCode, tt.want)
  4763  		}
  4764  	}
  4765  }
  4766  
  4767  func TestServerRequestContextCancel_ServeHTTPDone(t *testing.T) {
  4768  	run(t, testServerRequestContextCancel_ServeHTTPDone)
  4769  }
  4770  func testServerRequestContextCancel_ServeHTTPDone(t *testing.T, mode testMode) {
  4771  	ctxc := make(chan context.Context, 1)
  4772  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4773  		ctx := r.Context()
  4774  		select {
  4775  		case <-ctx.Done():
  4776  			t.Error("should not be Done in ServeHTTP")
  4777  		default:
  4778  		}
  4779  		ctxc <- ctx
  4780  	}))
  4781  	res, err := cst.c.Get(cst.ts.URL)
  4782  	if err != nil {
  4783  		t.Fatal(err)
  4784  	}
  4785  	res.Body.Close()
  4786  	ctx := <-ctxc
  4787  	select {
  4788  	case <-ctx.Done():
  4789  	default:
  4790  		t.Error("context should be done after ServeHTTP completes")
  4791  	}
  4792  }
  4793  
  4794  // Tests that the Request.Context available to the Handler is canceled
  4795  // if the peer closes their TCP connection. This requires that the server
  4796  // is always blocked in a Read call so it notices the EOF from the client.
  4797  // See issues 15927 and 15224.
  4798  func TestServerRequestContextCancel_ConnClose(t *testing.T) {
  4799  	run(t, testServerRequestContextCancel_ConnClose, []testMode{http1Mode})
  4800  }
  4801  func testServerRequestContextCancel_ConnClose(t *testing.T, mode testMode) {
  4802  	inHandler := make(chan struct{})
  4803  	handlerDone := make(chan struct{})
  4804  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4805  		close(inHandler)
  4806  		<-r.Context().Done()
  4807  		close(handlerDone)
  4808  	})).ts
  4809  	c, err := net.Dial("tcp", ts.Listener.Addr().String())
  4810  	if err != nil {
  4811  		t.Fatal(err)
  4812  	}
  4813  	defer c.Close()
  4814  	io.WriteString(c, "GET / HTTP/1.1\r\nHost: foo\r\n\r\n")
  4815  	<-inHandler
  4816  	c.Close() // this should trigger the context being done
  4817  	<-handlerDone
  4818  }
  4819  
  4820  func TestServerContext_ServerContextKey(t *testing.T) {
  4821  	run(t, testServerContext_ServerContextKey)
  4822  }
  4823  func testServerContext_ServerContextKey(t *testing.T, mode testMode) {
  4824  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4825  		ctx := r.Context()
  4826  		got := ctx.Value(ServerContextKey)
  4827  		if _, ok := got.(*Server); !ok {
  4828  			t.Errorf("context value = %T; want *http.Server", got)
  4829  		}
  4830  	}))
  4831  	res, err := cst.c.Get(cst.ts.URL)
  4832  	if err != nil {
  4833  		t.Fatal(err)
  4834  	}
  4835  	res.Body.Close()
  4836  }
  4837  
  4838  func TestServerContext_LocalAddrContextKey(t *testing.T) {
  4839  	run(t, testServerContext_LocalAddrContextKey)
  4840  }
  4841  func testServerContext_LocalAddrContextKey(t *testing.T, mode testMode) {
  4842  	ch := make(chan any, 1)
  4843  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  4844  		ch <- r.Context().Value(LocalAddrContextKey)
  4845  	}))
  4846  	if _, err := cst.c.Head(cst.ts.URL); err != nil {
  4847  		t.Fatal(err)
  4848  	}
  4849  
  4850  	host := cst.ts.Listener.Addr().String()
  4851  	got := <-ch
  4852  	if addr, ok := got.(net.Addr); !ok {
  4853  		t.Errorf("local addr value = %T; want net.Addr", got)
  4854  	} else if fmt.Sprint(addr) != host {
  4855  		t.Errorf("local addr = %v; want %v", addr, host)
  4856  	}
  4857  }
  4858  
  4859  // https://golang.org/issue/15960
  4860  func TestHandlerSetTransferEncodingChunked(t *testing.T) {
  4861  	setParallel(t)
  4862  	defer afterTest(t)
  4863  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  4864  		w.Header().Set("Transfer-Encoding", "chunked")
  4865  		w.Write([]byte("hello"))
  4866  	}))
  4867  	resp := ht.rawResponse("GET / HTTP/1.1\nHost: foo")
  4868  	const hdr = "Transfer-Encoding: chunked"
  4869  	if n := strings.Count(resp, hdr); n != 1 {
  4870  		t.Errorf("want 1 occurrence of %q in response, got %v\nresponse: %v", hdr, n, resp)
  4871  	}
  4872  }
  4873  
  4874  // https://golang.org/issue/16063
  4875  func TestHandlerSetTransferEncodingGzip(t *testing.T) {
  4876  	setParallel(t)
  4877  	defer afterTest(t)
  4878  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  4879  		w.Header().Set("Transfer-Encoding", "gzip")
  4880  		gz := gzip.NewWriter(w)
  4881  		gz.Write([]byte("hello"))
  4882  		gz.Close()
  4883  	}))
  4884  	resp := ht.rawResponse("GET / HTTP/1.1\nHost: foo")
  4885  	for _, v := range []string{"gzip", "chunked"} {
  4886  		hdr := "Transfer-Encoding: " + v
  4887  		if n := strings.Count(resp, hdr); n != 1 {
  4888  			t.Errorf("want 1 occurrence of %q in response, got %v\nresponse: %v", hdr, n, resp)
  4889  		}
  4890  	}
  4891  }
  4892  
  4893  func BenchmarkClientServer(b *testing.B) {
  4894  	run(b, benchmarkClientServer, []testMode{http1Mode, https1Mode, http2Mode})
  4895  }
  4896  func benchmarkClientServer(b *testing.B, mode testMode) {
  4897  	b.ReportAllocs()
  4898  	b.StopTimer()
  4899  	ts := newClientServerTest(b, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  4900  		fmt.Fprintf(rw, "Hello world.\n")
  4901  	})).ts
  4902  	b.StartTimer()
  4903  
  4904  	c := ts.Client()
  4905  	for i := 0; i < b.N; i++ {
  4906  		res, err := c.Get(ts.URL)
  4907  		if err != nil {
  4908  			b.Fatal("Get:", err)
  4909  		}
  4910  		all, err := io.ReadAll(res.Body)
  4911  		res.Body.Close()
  4912  		if err != nil {
  4913  			b.Fatal("ReadAll:", err)
  4914  		}
  4915  		body := string(all)
  4916  		if body != "Hello world.\n" {
  4917  			b.Fatal("Got body:", body)
  4918  		}
  4919  	}
  4920  
  4921  	b.StopTimer()
  4922  }
  4923  
  4924  func BenchmarkClientServerParallel(b *testing.B) {
  4925  	for _, parallelism := range []int{4, 64} {
  4926  		b.Run(fmt.Sprint(parallelism), func(b *testing.B) {
  4927  			run(b, func(b *testing.B, mode testMode) {
  4928  				benchmarkClientServerParallel(b, parallelism, mode)
  4929  			}, []testMode{http1Mode, https1Mode, http2Mode})
  4930  		})
  4931  	}
  4932  }
  4933  
  4934  func benchmarkClientServerParallel(b *testing.B, parallelism int, mode testMode) {
  4935  	b.ReportAllocs()
  4936  	ts := newClientServerTest(b, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  4937  		fmt.Fprintf(rw, "Hello world.\n")
  4938  	})).ts
  4939  	b.ResetTimer()
  4940  	b.SetParallelism(parallelism)
  4941  	b.RunParallel(func(pb *testing.PB) {
  4942  		c := ts.Client()
  4943  		for pb.Next() {
  4944  			res, err := c.Get(ts.URL)
  4945  			if err != nil {
  4946  				b.Logf("Get: %v", err)
  4947  				continue
  4948  			}
  4949  			all, err := io.ReadAll(res.Body)
  4950  			res.Body.Close()
  4951  			if err != nil {
  4952  				b.Logf("ReadAll: %v", err)
  4953  				continue
  4954  			}
  4955  			body := string(all)
  4956  			if body != "Hello world.\n" {
  4957  				panic("Got body: " + body)
  4958  			}
  4959  		}
  4960  	})
  4961  }
  4962  
  4963  // A benchmark for profiling the server without the HTTP client code.
  4964  // The client code runs in a subprocess.
  4965  //
  4966  // For use like:
  4967  //
  4968  //	$ go test -c
  4969  //	$ ./http.test -test.run=XX -test.bench=BenchmarkServer -test.benchtime=15s -test.cpuprofile=http.prof
  4970  //	$ go tool pprof http.test http.prof
  4971  //	(pprof) web
  4972  func BenchmarkServer(b *testing.B) {
  4973  	b.ReportAllocs()
  4974  	// Child process mode;
  4975  	if url := os.Getenv("TEST_BENCH_SERVER_URL"); url != "" {
  4976  		n, err := strconv.Atoi(os.Getenv("TEST_BENCH_CLIENT_N"))
  4977  		if err != nil {
  4978  			panic(err)
  4979  		}
  4980  		for i := 0; i < n; i++ {
  4981  			res, err := Get(url)
  4982  			if err != nil {
  4983  				log.Panicf("Get: %v", err)
  4984  			}
  4985  			all, err := io.ReadAll(res.Body)
  4986  			res.Body.Close()
  4987  			if err != nil {
  4988  				log.Panicf("ReadAll: %v", err)
  4989  			}
  4990  			body := string(all)
  4991  			if body != "Hello world.\n" {
  4992  				log.Panicf("Got body: %q", body)
  4993  			}
  4994  		}
  4995  		os.Exit(0)
  4996  		return
  4997  	}
  4998  
  4999  	var res = []byte("Hello world.\n")
  5000  	b.StopTimer()
  5001  	ts := httptest.NewServer(HandlerFunc(func(rw ResponseWriter, r *Request) {
  5002  		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
  5003  		rw.Write(res)
  5004  	}))
  5005  	defer ts.Close()
  5006  	b.StartTimer()
  5007  
  5008  	cmd := exec.Command(os.Args[0], "-test.run=XXXX", "-test.bench=BenchmarkServer$")
  5009  	cmd.Env = append([]string{
  5010  		fmt.Sprintf("TEST_BENCH_CLIENT_N=%d", b.N),
  5011  		fmt.Sprintf("TEST_BENCH_SERVER_URL=%s", ts.URL),
  5012  	}, os.Environ()...)
  5013  	out, err := cmd.CombinedOutput()
  5014  	if err != nil {
  5015  		b.Errorf("Test failure: %v, with output: %s", err, out)
  5016  	}
  5017  }
  5018  
  5019  // getNoBody wraps Get but closes any Response.Body before returning the response.
  5020  func getNoBody(urlStr string) (*Response, error) {
  5021  	res, err := Get(urlStr)
  5022  	if err != nil {
  5023  		return nil, err
  5024  	}
  5025  	res.Body.Close()
  5026  	return res, nil
  5027  }
  5028  
  5029  // A benchmark for profiling the client without the HTTP server code.
  5030  // The server code runs in a subprocess.
  5031  func BenchmarkClient(b *testing.B) {
  5032  	b.ReportAllocs()
  5033  	b.StopTimer()
  5034  	defer afterTest(b)
  5035  
  5036  	var data = []byte("Hello world.\n")
  5037  	if server := os.Getenv("TEST_BENCH_SERVER"); server != "" {
  5038  		// Server process mode.
  5039  		port := os.Getenv("TEST_BENCH_SERVER_PORT") // can be set by user
  5040  		if port == "" {
  5041  			port = "0"
  5042  		}
  5043  		ln, err := net.Listen("tcp", "localhost:"+port)
  5044  		if err != nil {
  5045  			fmt.Fprintln(os.Stderr, err.Error())
  5046  			os.Exit(1)
  5047  		}
  5048  		fmt.Println(ln.Addr().String())
  5049  		HandleFunc("/", func(w ResponseWriter, r *Request) {
  5050  			r.ParseForm()
  5051  			if r.Form.Get("stop") != "" {
  5052  				os.Exit(0)
  5053  			}
  5054  			w.Header().Set("Content-Type", "text/html; charset=utf-8")
  5055  			w.Write(data)
  5056  		})
  5057  		var srv Server
  5058  		log.Fatal(srv.Serve(ln))
  5059  	}
  5060  
  5061  	// Start server process.
  5062  	ctx, cancel := context.WithCancel(context.Background())
  5063  	cmd := testenv.CommandContext(b, ctx, os.Args[0], "-test.run=XXXX", "-test.bench=BenchmarkClient$")
  5064  	cmd.Env = append(cmd.Environ(), "TEST_BENCH_SERVER=yes")
  5065  	cmd.Stderr = os.Stderr
  5066  	stdout, err := cmd.StdoutPipe()
  5067  	if err != nil {
  5068  		b.Fatal(err)
  5069  	}
  5070  	if err := cmd.Start(); err != nil {
  5071  		b.Fatalf("subprocess failed to start: %v", err)
  5072  	}
  5073  
  5074  	done := make(chan error, 1)
  5075  	go func() {
  5076  		done <- cmd.Wait()
  5077  		close(done)
  5078  	}()
  5079  	defer func() {
  5080  		cancel()
  5081  		<-done
  5082  	}()
  5083  
  5084  	// Wait for the server in the child process to respond and tell us
  5085  	// its listening address, once it's started listening:
  5086  	bs := bufio.NewScanner(stdout)
  5087  	if !bs.Scan() {
  5088  		b.Fatalf("failed to read listening URL from child: %v", bs.Err())
  5089  	}
  5090  	url := "http://" + strings.TrimSpace(bs.Text()) + "/"
  5091  	if _, err := getNoBody(url); err != nil {
  5092  		b.Fatalf("initial probe of child process failed: %v", err)
  5093  	}
  5094  
  5095  	// Do b.N requests to the server.
  5096  	b.StartTimer()
  5097  	for i := 0; i < b.N; i++ {
  5098  		res, err := Get(url)
  5099  		if err != nil {
  5100  			b.Fatalf("Get: %v", err)
  5101  		}
  5102  		body, err := io.ReadAll(res.Body)
  5103  		res.Body.Close()
  5104  		if err != nil {
  5105  			b.Fatalf("ReadAll: %v", err)
  5106  		}
  5107  		if !bytes.Equal(body, data) {
  5108  			b.Fatalf("Got body: %q", body)
  5109  		}
  5110  	}
  5111  	b.StopTimer()
  5112  
  5113  	// Instruct server process to stop.
  5114  	getNoBody(url + "?stop=yes")
  5115  	if err := <-done; err != nil {
  5116  		b.Fatalf("subprocess failed: %v", err)
  5117  	}
  5118  }
  5119  
  5120  func BenchmarkServerFakeConnNoKeepAlive(b *testing.B) {
  5121  	b.ReportAllocs()
  5122  	req := reqBytes(`GET / HTTP/1.0
  5123  Host: golang.org
  5124  Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
  5125  User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17
  5126  Accept-Encoding: gzip,deflate,sdch
  5127  Accept-Language: en-US,en;q=0.8
  5128  Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
  5129  `)
  5130  	res := []byte("Hello world!\n")
  5131  
  5132  	conn := &testConn{
  5133  		// testConn.Close will not push into the channel
  5134  		// if it's full.
  5135  		closec: make(chan bool, 1),
  5136  	}
  5137  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5138  		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
  5139  		rw.Write(res)
  5140  	})
  5141  	ln := new(oneConnListener)
  5142  	for i := 0; i < b.N; i++ {
  5143  		conn.readBuf.Reset()
  5144  		conn.writeBuf.Reset()
  5145  		conn.readBuf.Write(req)
  5146  		ln.conn = conn
  5147  		Serve(ln, handler)
  5148  		<-conn.closec
  5149  	}
  5150  }
  5151  
  5152  // repeatReader reads content count times, then EOFs.
  5153  type repeatReader struct {
  5154  	content []byte
  5155  	count   int
  5156  	off     int
  5157  }
  5158  
  5159  func (r *repeatReader) Read(p []byte) (n int, err error) {
  5160  	if r.count <= 0 {
  5161  		return 0, io.EOF
  5162  	}
  5163  	n = copy(p, r.content[r.off:])
  5164  	r.off += n
  5165  	if r.off == len(r.content) {
  5166  		r.count--
  5167  		r.off = 0
  5168  	}
  5169  	return
  5170  }
  5171  
  5172  func BenchmarkServerFakeConnWithKeepAlive(b *testing.B) {
  5173  	b.ReportAllocs()
  5174  
  5175  	req := reqBytes(`GET / HTTP/1.1
  5176  Host: golang.org
  5177  Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
  5178  User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17
  5179  Accept-Encoding: gzip,deflate,sdch
  5180  Accept-Language: en-US,en;q=0.8
  5181  Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
  5182  `)
  5183  	res := []byte("Hello world!\n")
  5184  
  5185  	conn := &rwTestConn{
  5186  		Reader: &repeatReader{content: req, count: b.N},
  5187  		Writer: io.Discard,
  5188  		closec: make(chan bool, 1),
  5189  	}
  5190  	handled := 0
  5191  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5192  		handled++
  5193  		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
  5194  		rw.Write(res)
  5195  	})
  5196  	ln := &oneConnListener{conn: conn}
  5197  	go Serve(ln, handler)
  5198  	<-conn.closec
  5199  	if b.N != handled {
  5200  		b.Errorf("b.N=%d but handled %d", b.N, handled)
  5201  	}
  5202  }
  5203  
  5204  // same as above, but representing the most simple possible request
  5205  // and handler. Notably: the handler does not call rw.Header().
  5206  func BenchmarkServerFakeConnWithKeepAliveLite(b *testing.B) {
  5207  	b.ReportAllocs()
  5208  
  5209  	req := reqBytes(`GET / HTTP/1.1
  5210  Host: golang.org
  5211  `)
  5212  	res := []byte("Hello world!\n")
  5213  
  5214  	conn := &rwTestConn{
  5215  		Reader: &repeatReader{content: req, count: b.N},
  5216  		Writer: io.Discard,
  5217  		closec: make(chan bool, 1),
  5218  	}
  5219  	handled := 0
  5220  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5221  		handled++
  5222  		rw.Write(res)
  5223  	})
  5224  	ln := &oneConnListener{conn: conn}
  5225  	go Serve(ln, handler)
  5226  	<-conn.closec
  5227  	if b.N != handled {
  5228  		b.Errorf("b.N=%d but handled %d", b.N, handled)
  5229  	}
  5230  }
  5231  
  5232  const someResponse = "<html>some response</html>"
  5233  
  5234  // A Response that's just no bigger than 2KB, the buffer-before-chunking threshold.
  5235  var response = bytes.Repeat([]byte(someResponse), 2<<10/len(someResponse))
  5236  
  5237  // Both Content-Type and Content-Length set. Should be no buffering.
  5238  func BenchmarkServerHandlerTypeLen(b *testing.B) {
  5239  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5240  		w.Header().Set("Content-Type", "text/html")
  5241  		w.Header().Set("Content-Length", strconv.Itoa(len(response)))
  5242  		w.Write(response)
  5243  	}))
  5244  }
  5245  
  5246  // A Content-Type is set, but no length. No sniffing, but will count the Content-Length.
  5247  func BenchmarkServerHandlerNoLen(b *testing.B) {
  5248  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5249  		w.Header().Set("Content-Type", "text/html")
  5250  		w.Write(response)
  5251  	}))
  5252  }
  5253  
  5254  // A Content-Length is set, but the Content-Type will be sniffed.
  5255  func BenchmarkServerHandlerNoType(b *testing.B) {
  5256  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5257  		w.Header().Set("Content-Length", strconv.Itoa(len(response)))
  5258  		w.Write(response)
  5259  	}))
  5260  }
  5261  
  5262  // Neither a Content-Type or Content-Length, so sniffed and counted.
  5263  func BenchmarkServerHandlerNoHeader(b *testing.B) {
  5264  	benchmarkHandler(b, HandlerFunc(func(w ResponseWriter, r *Request) {
  5265  		w.Write(response)
  5266  	}))
  5267  }
  5268  
  5269  func benchmarkHandler(b *testing.B, h Handler) {
  5270  	b.ReportAllocs()
  5271  	req := reqBytes(`GET / HTTP/1.1
  5272  Host: golang.org
  5273  `)
  5274  	conn := &rwTestConn{
  5275  		Reader: &repeatReader{content: req, count: b.N},
  5276  		Writer: io.Discard,
  5277  		closec: make(chan bool, 1),
  5278  	}
  5279  	handled := 0
  5280  	handler := HandlerFunc(func(rw ResponseWriter, r *Request) {
  5281  		handled++
  5282  		h.ServeHTTP(rw, r)
  5283  	})
  5284  	ln := &oneConnListener{conn: conn}
  5285  	go Serve(ln, handler)
  5286  	<-conn.closec
  5287  	if b.N != handled {
  5288  		b.Errorf("b.N=%d but handled %d", b.N, handled)
  5289  	}
  5290  }
  5291  
  5292  func BenchmarkServerHijack(b *testing.B) {
  5293  	b.ReportAllocs()
  5294  	req := reqBytes(`GET / HTTP/1.1
  5295  Host: golang.org
  5296  `)
  5297  	h := HandlerFunc(func(w ResponseWriter, r *Request) {
  5298  		conn, _, err := w.(Hijacker).Hijack()
  5299  		if err != nil {
  5300  			panic(err)
  5301  		}
  5302  		conn.Close()
  5303  	})
  5304  	conn := &rwTestConn{
  5305  		Writer: io.Discard,
  5306  		closec: make(chan bool, 1),
  5307  	}
  5308  	ln := &oneConnListener{conn: conn}
  5309  	for i := 0; i < b.N; i++ {
  5310  		conn.Reader = bytes.NewReader(req)
  5311  		ln.conn = conn
  5312  		Serve(ln, h)
  5313  		<-conn.closec
  5314  	}
  5315  }
  5316  
  5317  func BenchmarkCloseNotifier(b *testing.B) { run(b, benchmarkCloseNotifier, []testMode{http1Mode}) }
  5318  func benchmarkCloseNotifier(b *testing.B, mode testMode) {
  5319  	b.ReportAllocs()
  5320  	b.StopTimer()
  5321  	sawClose := make(chan bool)
  5322  	ts := newClientServerTest(b, mode, HandlerFunc(func(rw ResponseWriter, req *Request) {
  5323  		<-rw.(CloseNotifier).CloseNotify()
  5324  		sawClose <- true
  5325  	})).ts
  5326  	b.StartTimer()
  5327  	for i := 0; i < b.N; i++ {
  5328  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5329  		if err != nil {
  5330  			b.Fatalf("error dialing: %v", err)
  5331  		}
  5332  		_, err = fmt.Fprintf(conn, "GET / HTTP/1.1\r\nConnection: keep-alive\r\nHost: foo\r\n\r\n")
  5333  		if err != nil {
  5334  			b.Fatal(err)
  5335  		}
  5336  		conn.Close()
  5337  		<-sawClose
  5338  	}
  5339  	b.StopTimer()
  5340  }
  5341  
  5342  // Verify this doesn't race (Issue 16505)
  5343  func TestConcurrentServerServe(t *testing.T) {
  5344  	setParallel(t)
  5345  	for i := 0; i < 100; i++ {
  5346  		ln1 := &oneConnListener{conn: nil}
  5347  		ln2 := &oneConnListener{conn: nil}
  5348  		srv := Server{}
  5349  		go func() { srv.Serve(ln1) }()
  5350  		go func() { srv.Serve(ln2) }()
  5351  	}
  5352  }
  5353  
  5354  func TestServerIdleTimeout(t *testing.T) { run(t, testServerIdleTimeout, []testMode{http1Mode}) }
  5355  func testServerIdleTimeout(t *testing.T, mode testMode) {
  5356  	if testing.Short() {
  5357  		t.Skip("skipping in short mode")
  5358  	}
  5359  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5360  		io.Copy(io.Discard, r.Body)
  5361  		io.WriteString(w, r.RemoteAddr)
  5362  	}), func(ts *httptest.Server) {
  5363  		ts.Config.ReadHeaderTimeout = 1 * time.Second
  5364  		ts.Config.IdleTimeout = 2 * time.Second
  5365  	}).ts
  5366  	c := ts.Client()
  5367  
  5368  	get := func() string {
  5369  		res, err := c.Get(ts.URL)
  5370  		if err != nil {
  5371  			t.Fatal(err)
  5372  		}
  5373  		defer res.Body.Close()
  5374  		slurp, err := io.ReadAll(res.Body)
  5375  		if err != nil {
  5376  			t.Fatal(err)
  5377  		}
  5378  		return string(slurp)
  5379  	}
  5380  
  5381  	a1, a2 := get(), get()
  5382  	if a1 != a2 {
  5383  		t.Fatalf("did requests on different connections")
  5384  	}
  5385  	time.Sleep(3 * time.Second)
  5386  	a3 := get()
  5387  	if a2 == a3 {
  5388  		t.Fatal("request three unexpectedly on same connection")
  5389  	}
  5390  
  5391  	// And test that ReadHeaderTimeout still works:
  5392  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5393  	if err != nil {
  5394  		t.Fatal(err)
  5395  	}
  5396  	defer conn.Close()
  5397  	conn.Write([]byte("GET / HTTP/1.1\r\nHost: foo.com\r\n"))
  5398  	time.Sleep(2 * time.Second)
  5399  	if _, err := io.CopyN(io.Discard, conn, 1); err == nil {
  5400  		t.Fatal("copy byte succeeded; want err")
  5401  	}
  5402  }
  5403  
  5404  func get(t *testing.T, c *Client, url string) string {
  5405  	res, err := c.Get(url)
  5406  	if err != nil {
  5407  		t.Fatal(err)
  5408  	}
  5409  	defer res.Body.Close()
  5410  	slurp, err := io.ReadAll(res.Body)
  5411  	if err != nil {
  5412  		t.Fatal(err)
  5413  	}
  5414  	return string(slurp)
  5415  }
  5416  
  5417  // Tests that calls to Server.SetKeepAlivesEnabled(false) closes any
  5418  // currently-open connections.
  5419  func TestServerSetKeepAlivesEnabledClosesConns(t *testing.T) {
  5420  	run(t, testServerSetKeepAlivesEnabledClosesConns, []testMode{http1Mode})
  5421  }
  5422  func testServerSetKeepAlivesEnabledClosesConns(t *testing.T, mode testMode) {
  5423  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5424  		io.WriteString(w, r.RemoteAddr)
  5425  	})).ts
  5426  
  5427  	c := ts.Client()
  5428  	tr := c.Transport.(*Transport)
  5429  
  5430  	get := func() string { return get(t, c, ts.URL) }
  5431  
  5432  	a1, a2 := get(), get()
  5433  	if a1 == a2 {
  5434  		t.Logf("made two requests from a single conn %q (as expected)", a1)
  5435  	} else {
  5436  		t.Errorf("server reported requests from %q and %q; expected same connection", a1, a2)
  5437  	}
  5438  
  5439  	// The two requests should have used the same connection,
  5440  	// and there should not have been a second connection that
  5441  	// was created by racing dial against reuse.
  5442  	// (The first get was completed when the second get started.)
  5443  	if conns := tr.IdleConnStrsForTesting(); len(conns) != 1 {
  5444  		t.Errorf("found %d idle conns (%q); want 1", len(conns), conns)
  5445  	}
  5446  
  5447  	// SetKeepAlivesEnabled should discard idle conns.
  5448  	ts.Config.SetKeepAlivesEnabled(false)
  5449  
  5450  	waitCondition(t, 10*time.Millisecond, func(d time.Duration) bool {
  5451  		if conns := tr.IdleConnStrsForTesting(); len(conns) > 0 {
  5452  			if d > 0 {
  5453  				t.Logf("idle conns %v after SetKeepAlivesEnabled called = %q; waiting for empty", d, conns)
  5454  			}
  5455  			return false
  5456  		}
  5457  		return true
  5458  	})
  5459  
  5460  	// If we make a third request it should use a new connection, but in general
  5461  	// we have no way to verify that: the new connection could happen to reuse the
  5462  	// exact same ports from the previous connection.
  5463  }
  5464  
  5465  func TestServerShutdown(t *testing.T) { run(t, testServerShutdown) }
  5466  func testServerShutdown(t *testing.T, mode testMode) {
  5467  	var cst *clientServerTest
  5468  
  5469  	var once sync.Once
  5470  	statesRes := make(chan map[ConnState]int, 1)
  5471  	shutdownRes := make(chan error, 1)
  5472  	gotOnShutdown := make(chan struct{})
  5473  	handler := HandlerFunc(func(w ResponseWriter, r *Request) {
  5474  		first := false
  5475  		once.Do(func() {
  5476  			statesRes <- cst.ts.Config.ExportAllConnsByState()
  5477  			go func() {
  5478  				shutdownRes <- cst.ts.Config.Shutdown(context.Background())
  5479  			}()
  5480  			first = true
  5481  		})
  5482  
  5483  		if first {
  5484  			// Shutdown is graceful, so it should not interrupt this in-flight response
  5485  			// but should reject new requests. (Since this request is still in flight,
  5486  			// the server's port should not be reused for another server yet.)
  5487  			<-gotOnShutdown
  5488  			// TODO(#59038): The HTTP/2 server empirically does not always reject new
  5489  			// requests. As a workaround, loop until we see a failure.
  5490  			for !t.Failed() {
  5491  				res, err := cst.c.Get(cst.ts.URL)
  5492  				if err != nil {
  5493  					break
  5494  				}
  5495  				out, _ := io.ReadAll(res.Body)
  5496  				res.Body.Close()
  5497  				if mode == http2Mode {
  5498  					t.Logf("%v: unexpected success (%q). Listener should be closed before OnShutdown is called.", cst.ts.URL, out)
  5499  					t.Logf("Retrying to work around https://go.dev/issue/59038.")
  5500  					continue
  5501  				}
  5502  				t.Errorf("%v: unexpected success (%q). Listener should be closed before OnShutdown is called.", cst.ts.URL, out)
  5503  			}
  5504  		}
  5505  
  5506  		io.WriteString(w, r.RemoteAddr)
  5507  	})
  5508  
  5509  	cst = newClientServerTest(t, mode, handler, func(srv *httptest.Server) {
  5510  		srv.Config.RegisterOnShutdown(func() { close(gotOnShutdown) })
  5511  	})
  5512  
  5513  	out := get(t, cst.c, cst.ts.URL) // calls t.Fail on failure
  5514  	t.Logf("%v: %q", cst.ts.URL, out)
  5515  
  5516  	if err := <-shutdownRes; err != nil {
  5517  		t.Fatalf("Shutdown: %v", err)
  5518  	}
  5519  	<-gotOnShutdown // Will hang if RegisterOnShutdown is broken.
  5520  
  5521  	if states := <-statesRes; states[StateActive] != 1 {
  5522  		t.Errorf("connection in wrong state, %v", states)
  5523  	}
  5524  }
  5525  
  5526  func TestServerShutdownStateNew(t *testing.T) { run(t, testServerShutdownStateNew) }
  5527  func testServerShutdownStateNew(t *testing.T, mode testMode) {
  5528  	if testing.Short() {
  5529  		t.Skip("test takes 5-6 seconds; skipping in short mode")
  5530  	}
  5531  
  5532  	var connAccepted sync.WaitGroup
  5533  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5534  		// nothing.
  5535  	}), func(ts *httptest.Server) {
  5536  		ts.Config.ConnState = func(conn net.Conn, state ConnState) {
  5537  			if state == StateNew {
  5538  				connAccepted.Done()
  5539  			}
  5540  		}
  5541  	}).ts
  5542  
  5543  	// Start a connection but never write to it.
  5544  	connAccepted.Add(1)
  5545  	c, err := net.Dial("tcp", ts.Listener.Addr().String())
  5546  	if err != nil {
  5547  		t.Fatal(err)
  5548  	}
  5549  	defer c.Close()
  5550  
  5551  	// Wait for the connection to be accepted by the server. Otherwise, if
  5552  	// Shutdown happens to run first, the server will be closed when
  5553  	// encountering the connection, in which case it will be rejected
  5554  	// immediately.
  5555  	connAccepted.Wait()
  5556  
  5557  	shutdownRes := make(chan error, 1)
  5558  	go func() {
  5559  		shutdownRes <- ts.Config.Shutdown(context.Background())
  5560  	}()
  5561  	readRes := make(chan error, 1)
  5562  	go func() {
  5563  		_, err := c.Read([]byte{0})
  5564  		readRes <- err
  5565  	}()
  5566  
  5567  	// TODO(#59037): This timeout is hard-coded in closeIdleConnections.
  5568  	// It is undocumented, and some users may find it surprising.
  5569  	// Either document it, or switch to a less surprising behavior.
  5570  	const expectTimeout = 5 * time.Second
  5571  
  5572  	t0 := time.Now()
  5573  	select {
  5574  	case got := <-shutdownRes:
  5575  		d := time.Since(t0)
  5576  		if got != nil {
  5577  			t.Fatalf("shutdown error after %v: %v", d, err)
  5578  		}
  5579  		if d < expectTimeout/2 {
  5580  			t.Errorf("shutdown too soon after %v", d)
  5581  		}
  5582  	case <-time.After(expectTimeout * 3 / 2):
  5583  		t.Fatalf("timeout waiting for shutdown")
  5584  	}
  5585  
  5586  	// Wait for c.Read to unblock; should be already done at this point,
  5587  	// or within a few milliseconds.
  5588  	if err := <-readRes; err == nil {
  5589  		t.Error("expected error from Read")
  5590  	}
  5591  }
  5592  
  5593  // Issue 17878: tests that we can call Close twice.
  5594  func TestServerCloseDeadlock(t *testing.T) {
  5595  	var s Server
  5596  	s.Close()
  5597  	s.Close()
  5598  }
  5599  
  5600  // Issue 17717: tests that Server.SetKeepAlivesEnabled is respected by
  5601  // both HTTP/1 and HTTP/2.
  5602  func TestServerKeepAlivesEnabled(t *testing.T) { run(t, testServerKeepAlivesEnabled, testNotParallel) }
  5603  func testServerKeepAlivesEnabled(t *testing.T, mode testMode) {
  5604  	if mode == http2Mode {
  5605  		restore := ExportSetH2GoawayTimeout(10 * time.Millisecond)
  5606  		defer restore()
  5607  	}
  5608  	// Not parallel: messes with global variable. (http2goAwayTimeout)
  5609  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {}))
  5610  	defer cst.close()
  5611  	srv := cst.ts.Config
  5612  	srv.SetKeepAlivesEnabled(false)
  5613  	for try := 0; try < 2; try++ {
  5614  		waitCondition(t, 10*time.Millisecond, func(d time.Duration) bool {
  5615  			if !srv.ExportAllConnsIdle() {
  5616  				if d > 0 {
  5617  					t.Logf("test server still has active conns after %v", d)
  5618  				}
  5619  				return false
  5620  			}
  5621  			return true
  5622  		})
  5623  		conns := 0
  5624  		var info httptrace.GotConnInfo
  5625  		ctx := httptrace.WithClientTrace(context.Background(), &httptrace.ClientTrace{
  5626  			GotConn: func(v httptrace.GotConnInfo) {
  5627  				conns++
  5628  				info = v
  5629  			},
  5630  		})
  5631  		req, err := NewRequestWithContext(ctx, "GET", cst.ts.URL, nil)
  5632  		if err != nil {
  5633  			t.Fatal(err)
  5634  		}
  5635  		res, err := cst.c.Do(req)
  5636  		if err != nil {
  5637  			t.Fatal(err)
  5638  		}
  5639  		res.Body.Close()
  5640  		if conns != 1 {
  5641  			t.Fatalf("request %v: got %v conns, want 1", try, conns)
  5642  		}
  5643  		if info.Reused || info.WasIdle {
  5644  			t.Fatalf("request %v: Reused=%v (want false), WasIdle=%v (want false)", try, info.Reused, info.WasIdle)
  5645  		}
  5646  	}
  5647  }
  5648  
  5649  // Issue 18447: test that the Server's ReadTimeout is stopped while
  5650  // the server's doing its 1-byte background read between requests,
  5651  // waiting for the connection to maybe close.
  5652  func TestServerCancelsReadTimeoutWhenIdle(t *testing.T) { run(t, testServerCancelsReadTimeoutWhenIdle) }
  5653  func testServerCancelsReadTimeoutWhenIdle(t *testing.T, mode testMode) {
  5654  	runTimeSensitiveTest(t, []time.Duration{
  5655  		10 * time.Millisecond,
  5656  		50 * time.Millisecond,
  5657  		250 * time.Millisecond,
  5658  		time.Second,
  5659  		2 * time.Second,
  5660  	}, func(t *testing.T, timeout time.Duration) error {
  5661  		ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5662  			select {
  5663  			case <-time.After(2 * timeout):
  5664  				fmt.Fprint(w, "ok")
  5665  			case <-r.Context().Done():
  5666  				fmt.Fprint(w, r.Context().Err())
  5667  			}
  5668  		}), func(ts *httptest.Server) {
  5669  			ts.Config.ReadTimeout = timeout
  5670  		}).ts
  5671  
  5672  		c := ts.Client()
  5673  
  5674  		res, err := c.Get(ts.URL)
  5675  		if err != nil {
  5676  			return fmt.Errorf("Get: %v", err)
  5677  		}
  5678  		slurp, err := io.ReadAll(res.Body)
  5679  		res.Body.Close()
  5680  		if err != nil {
  5681  			return fmt.Errorf("Body ReadAll: %v", err)
  5682  		}
  5683  		if string(slurp) != "ok" {
  5684  			return fmt.Errorf("got: %q, want ok", slurp)
  5685  		}
  5686  		return nil
  5687  	})
  5688  }
  5689  
  5690  // Issue 54784: test that the Server's ReadHeaderTimeout only starts once the
  5691  // beginning of a request has been received, rather than including time the
  5692  // connection spent idle.
  5693  func TestServerCancelsReadHeaderTimeoutWhenIdle(t *testing.T) {
  5694  	run(t, testServerCancelsReadHeaderTimeoutWhenIdle, []testMode{http1Mode})
  5695  }
  5696  func testServerCancelsReadHeaderTimeoutWhenIdle(t *testing.T, mode testMode) {
  5697  	runTimeSensitiveTest(t, []time.Duration{
  5698  		10 * time.Millisecond,
  5699  		50 * time.Millisecond,
  5700  		250 * time.Millisecond,
  5701  		time.Second,
  5702  		2 * time.Second,
  5703  	}, func(t *testing.T, timeout time.Duration) error {
  5704  		ts := newClientServerTest(t, mode, serve(200), func(ts *httptest.Server) {
  5705  			ts.Config.ReadHeaderTimeout = timeout
  5706  			ts.Config.IdleTimeout = 0 // disable idle timeout
  5707  		}).ts
  5708  
  5709  		// rather than using an http.Client, create a single connection, so that
  5710  		// we can ensure this connection is not closed.
  5711  		conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5712  		if err != nil {
  5713  			t.Fatalf("dial failed: %v", err)
  5714  		}
  5715  		br := bufio.NewReader(conn)
  5716  		defer conn.Close()
  5717  
  5718  		if _, err := conn.Write([]byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")); err != nil {
  5719  			return fmt.Errorf("writing first request failed: %v", err)
  5720  		}
  5721  
  5722  		if _, err := ReadResponse(br, nil); err != nil {
  5723  			return fmt.Errorf("first response (before timeout) failed: %v", err)
  5724  		}
  5725  
  5726  		// wait for longer than the server's ReadHeaderTimeout, and then send
  5727  		// another request
  5728  		time.Sleep(timeout * 3 / 2)
  5729  
  5730  		if _, err := conn.Write([]byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")); err != nil {
  5731  			return fmt.Errorf("writing second request failed: %v", err)
  5732  		}
  5733  
  5734  		if _, err := ReadResponse(br, nil); err != nil {
  5735  			return fmt.Errorf("second response (after timeout) failed: %v", err)
  5736  		}
  5737  
  5738  		return nil
  5739  	})
  5740  }
  5741  
  5742  // runTimeSensitiveTest runs test with the provided durations until one passes.
  5743  // If they all fail, t.Fatal is called with the last one's duration and error value.
  5744  func runTimeSensitiveTest(t *testing.T, durations []time.Duration, test func(t *testing.T, d time.Duration) error) {
  5745  	for i, d := range durations {
  5746  		err := test(t, d)
  5747  		if err == nil {
  5748  			return
  5749  		}
  5750  		if i == len(durations)-1 {
  5751  			t.Fatalf("failed with duration %v: %v", d, err)
  5752  		}
  5753  	}
  5754  }
  5755  
  5756  // Issue 18535: test that the Server doesn't try to do a background
  5757  // read if it's already done one.
  5758  func TestServerDuplicateBackgroundRead(t *testing.T) {
  5759  	run(t, testServerDuplicateBackgroundRead, []testMode{http1Mode})
  5760  }
  5761  func testServerDuplicateBackgroundRead(t *testing.T, mode testMode) {
  5762  	if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm" {
  5763  		testenv.SkipFlaky(t, 24826)
  5764  	}
  5765  
  5766  	goroutines := 5
  5767  	requests := 2000
  5768  	if testing.Short() {
  5769  		goroutines = 3
  5770  		requests = 100
  5771  	}
  5772  
  5773  	hts := newClientServerTest(t, mode, HandlerFunc(NotFound)).ts
  5774  
  5775  	reqBytes := []byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")
  5776  
  5777  	var wg sync.WaitGroup
  5778  	for i := 0; i < goroutines; i++ {
  5779  		wg.Add(1)
  5780  		go func() {
  5781  			defer wg.Done()
  5782  			cn, err := net.Dial("tcp", hts.Listener.Addr().String())
  5783  			if err != nil {
  5784  				t.Error(err)
  5785  				return
  5786  			}
  5787  			defer cn.Close()
  5788  
  5789  			wg.Add(1)
  5790  			go func() {
  5791  				defer wg.Done()
  5792  				io.Copy(io.Discard, cn)
  5793  			}()
  5794  
  5795  			for j := 0; j < requests; j++ {
  5796  				if t.Failed() {
  5797  					return
  5798  				}
  5799  				_, err := cn.Write(reqBytes)
  5800  				if err != nil {
  5801  					t.Error(err)
  5802  					return
  5803  				}
  5804  			}
  5805  		}()
  5806  	}
  5807  	wg.Wait()
  5808  }
  5809  
  5810  // Test that the bufio.Reader returned by Hijack includes any buffered
  5811  // byte (from the Server's backgroundRead) in its buffer. We want the
  5812  // Handler code to be able to tell that a byte is available via
  5813  // bufio.Reader.Buffered(), without resorting to Reading it
  5814  // (potentially blocking) to get at it.
  5815  func TestServerHijackGetsBackgroundByte(t *testing.T) {
  5816  	run(t, testServerHijackGetsBackgroundByte, []testMode{http1Mode})
  5817  }
  5818  func testServerHijackGetsBackgroundByte(t *testing.T, mode testMode) {
  5819  	if runtime.GOOS == "plan9" {
  5820  		t.Skip("skipping test; see https://golang.org/issue/18657")
  5821  	}
  5822  	done := make(chan struct{})
  5823  	inHandler := make(chan bool, 1)
  5824  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5825  		defer close(done)
  5826  
  5827  		// Tell the client to send more data after the GET request.
  5828  		inHandler <- true
  5829  
  5830  		conn, buf, err := w.(Hijacker).Hijack()
  5831  		if err != nil {
  5832  			t.Error(err)
  5833  			return
  5834  		}
  5835  		defer conn.Close()
  5836  
  5837  		peek, err := buf.Reader.Peek(3)
  5838  		if string(peek) != "foo" || err != nil {
  5839  			t.Errorf("Peek = %q, %v; want foo, nil", peek, err)
  5840  		}
  5841  
  5842  		select {
  5843  		case <-r.Context().Done():
  5844  			t.Error("context unexpectedly canceled")
  5845  		default:
  5846  		}
  5847  	})).ts
  5848  
  5849  	cn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5850  	if err != nil {
  5851  		t.Fatal(err)
  5852  	}
  5853  	defer cn.Close()
  5854  	if _, err := cn.Write([]byte("GET / HTTP/1.1\r\nHost: e.com\r\n\r\n")); err != nil {
  5855  		t.Fatal(err)
  5856  	}
  5857  	<-inHandler
  5858  	if _, err := cn.Write([]byte("foo")); err != nil {
  5859  		t.Fatal(err)
  5860  	}
  5861  
  5862  	if err := cn.(*net.TCPConn).CloseWrite(); err != nil {
  5863  		t.Fatal(err)
  5864  	}
  5865  	<-done
  5866  }
  5867  
  5868  // Like TestServerHijackGetsBackgroundByte above but sending a
  5869  // immediate 1MB of data to the server to fill up the server's 4KB
  5870  // buffer.
  5871  func TestServerHijackGetsBackgroundByte_big(t *testing.T) {
  5872  	run(t, testServerHijackGetsBackgroundByte_big, []testMode{http1Mode})
  5873  }
  5874  func testServerHijackGetsBackgroundByte_big(t *testing.T, mode testMode) {
  5875  	if runtime.GOOS == "plan9" {
  5876  		t.Skip("skipping test; see https://golang.org/issue/18657")
  5877  	}
  5878  	done := make(chan struct{})
  5879  	const size = 8 << 10
  5880  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  5881  		defer close(done)
  5882  
  5883  		conn, buf, err := w.(Hijacker).Hijack()
  5884  		if err != nil {
  5885  			t.Error(err)
  5886  			return
  5887  		}
  5888  		defer conn.Close()
  5889  		slurp, err := io.ReadAll(buf.Reader)
  5890  		if err != nil {
  5891  			t.Errorf("Copy: %v", err)
  5892  		}
  5893  		allX := true
  5894  		for _, v := range slurp {
  5895  			if v != 'x' {
  5896  				allX = false
  5897  			}
  5898  		}
  5899  		if len(slurp) != size {
  5900  			t.Errorf("read %d; want %d", len(slurp), size)
  5901  		} else if !allX {
  5902  			t.Errorf("read %q; want %d 'x'", slurp, size)
  5903  		}
  5904  	})).ts
  5905  
  5906  	cn, err := net.Dial("tcp", ts.Listener.Addr().String())
  5907  	if err != nil {
  5908  		t.Fatal(err)
  5909  	}
  5910  	defer cn.Close()
  5911  	if _, err := fmt.Fprintf(cn, "GET / HTTP/1.1\r\nHost: e.com\r\n\r\n%s",
  5912  		strings.Repeat("x", size)); err != nil {
  5913  		t.Fatal(err)
  5914  	}
  5915  	if err := cn.(*net.TCPConn).CloseWrite(); err != nil {
  5916  		t.Fatal(err)
  5917  	}
  5918  
  5919  	<-done
  5920  }
  5921  
  5922  // Issue 18319: test that the Server validates the request method.
  5923  func TestServerValidatesMethod(t *testing.T) {
  5924  	tests := []struct {
  5925  		method string
  5926  		want   int
  5927  	}{
  5928  		{"GET", 200},
  5929  		{"GE(T", 400},
  5930  	}
  5931  	for _, tt := range tests {
  5932  		conn := &testConn{closec: make(chan bool, 1)}
  5933  		io.WriteString(&conn.readBuf, tt.method+" / HTTP/1.1\r\nHost: foo.example\r\n\r\n")
  5934  
  5935  		ln := &oneConnListener{conn}
  5936  		go Serve(ln, serve(200))
  5937  		<-conn.closec
  5938  		res, err := ReadResponse(bufio.NewReader(&conn.writeBuf), nil)
  5939  		if err != nil {
  5940  			t.Errorf("For %s, ReadResponse: %v", tt.method, res)
  5941  			continue
  5942  		}
  5943  		if res.StatusCode != tt.want {
  5944  			t.Errorf("For %s, Status = %d; want %d", tt.method, res.StatusCode, tt.want)
  5945  		}
  5946  	}
  5947  }
  5948  
  5949  // Listener for TestServerListenNotComparableListener.
  5950  type eofListenerNotComparable []int
  5951  
  5952  func (eofListenerNotComparable) Accept() (net.Conn, error) { return nil, io.EOF }
  5953  func (eofListenerNotComparable) Addr() net.Addr            { return nil }
  5954  func (eofListenerNotComparable) Close() error              { return nil }
  5955  
  5956  // Issue 24812: don't crash on non-comparable Listener
  5957  func TestServerListenNotComparableListener(t *testing.T) {
  5958  	var s Server
  5959  	s.Serve(make(eofListenerNotComparable, 1)) // used to panic
  5960  }
  5961  
  5962  // countCloseListener is a Listener wrapper that counts the number of Close calls.
  5963  type countCloseListener struct {
  5964  	net.Listener
  5965  	closes int32 // atomic
  5966  }
  5967  
  5968  func (p *countCloseListener) Close() error {
  5969  	var err error
  5970  	if n := atomic.AddInt32(&p.closes, 1); n == 1 && p.Listener != nil {
  5971  		err = p.Listener.Close()
  5972  	}
  5973  	return err
  5974  }
  5975  
  5976  // Issue 24803: don't call Listener.Close on Server.Shutdown.
  5977  func TestServerCloseListenerOnce(t *testing.T) {
  5978  	setParallel(t)
  5979  	defer afterTest(t)
  5980  
  5981  	ln := newLocalListener(t)
  5982  	defer ln.Close()
  5983  
  5984  	cl := &countCloseListener{Listener: ln}
  5985  	server := &Server{}
  5986  	sdone := make(chan bool, 1)
  5987  
  5988  	go func() {
  5989  		server.Serve(cl)
  5990  		sdone <- true
  5991  	}()
  5992  	time.Sleep(10 * time.Millisecond)
  5993  	server.Shutdown(context.Background())
  5994  	ln.Close()
  5995  	<-sdone
  5996  
  5997  	nclose := atomic.LoadInt32(&cl.closes)
  5998  	if nclose != 1 {
  5999  		t.Errorf("Close calls = %v; want 1", nclose)
  6000  	}
  6001  }
  6002  
  6003  // Issue 20239: don't block in Serve if Shutdown is called first.
  6004  func TestServerShutdownThenServe(t *testing.T) {
  6005  	var srv Server
  6006  	cl := &countCloseListener{Listener: nil}
  6007  	srv.Shutdown(context.Background())
  6008  	got := srv.Serve(cl)
  6009  	if got != ErrServerClosed {
  6010  		t.Errorf("Serve err = %v; want ErrServerClosed", got)
  6011  	}
  6012  	nclose := atomic.LoadInt32(&cl.closes)
  6013  	if nclose != 1 {
  6014  		t.Errorf("Close calls = %v; want 1", nclose)
  6015  	}
  6016  }
  6017  
  6018  // Issue 23351: document and test behavior of ServeMux with ports
  6019  func TestStripPortFromHost(t *testing.T) {
  6020  	mux := NewServeMux()
  6021  
  6022  	mux.HandleFunc("example.com/", func(w ResponseWriter, r *Request) {
  6023  		fmt.Fprintf(w, "OK")
  6024  	})
  6025  	mux.HandleFunc("example.com:9000/", func(w ResponseWriter, r *Request) {
  6026  		fmt.Fprintf(w, "uh-oh!")
  6027  	})
  6028  
  6029  	req := httptest.NewRequest("GET", "http://example.com:9000/", nil)
  6030  	rw := httptest.NewRecorder()
  6031  
  6032  	mux.ServeHTTP(rw, req)
  6033  
  6034  	response := rw.Body.String()
  6035  	if response != "OK" {
  6036  		t.Errorf("Response gotten was %q", response)
  6037  	}
  6038  }
  6039  
  6040  func TestServerContexts(t *testing.T) { run(t, testServerContexts) }
  6041  func testServerContexts(t *testing.T, mode testMode) {
  6042  	type baseKey struct{}
  6043  	type connKey struct{}
  6044  	ch := make(chan context.Context, 1)
  6045  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  6046  		ch <- r.Context()
  6047  	}), func(ts *httptest.Server) {
  6048  		ts.Config.BaseContext = func(ln net.Listener) context.Context {
  6049  			if strings.Contains(reflect.TypeOf(ln).String(), "onceClose") {
  6050  				t.Errorf("unexpected onceClose listener type %T", ln)
  6051  			}
  6052  			return context.WithValue(context.Background(), baseKey{}, "base")
  6053  		}
  6054  		ts.Config.ConnContext = func(ctx context.Context, c net.Conn) context.Context {
  6055  			if got, want := ctx.Value(baseKey{}), "base"; got != want {
  6056  				t.Errorf("in ConnContext, base context key = %#v; want %q", got, want)
  6057  			}
  6058  			return context.WithValue(ctx, connKey{}, "conn")
  6059  		}
  6060  	}).ts
  6061  	res, err := ts.Client().Get(ts.URL)
  6062  	if err != nil {
  6063  		t.Fatal(err)
  6064  	}
  6065  	res.Body.Close()
  6066  	ctx := <-ch
  6067  	if got, want := ctx.Value(baseKey{}), "base"; got != want {
  6068  		t.Errorf("base context key = %#v; want %q", got, want)
  6069  	}
  6070  	if got, want := ctx.Value(connKey{}), "conn"; got != want {
  6071  		t.Errorf("conn context key = %#v; want %q", got, want)
  6072  	}
  6073  }
  6074  
  6075  // Issue 35750: check ConnContext not modifying context for other connections
  6076  func TestConnContextNotModifyingAllContexts(t *testing.T) {
  6077  	run(t, testConnContextNotModifyingAllContexts)
  6078  }
  6079  func testConnContextNotModifyingAllContexts(t *testing.T, mode testMode) {
  6080  	type connKey struct{}
  6081  	ts := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  6082  		rw.Header().Set("Connection", "close")
  6083  	}), func(ts *httptest.Server) {
  6084  		ts.Config.ConnContext = func(ctx context.Context, c net.Conn) context.Context {
  6085  			if got := ctx.Value(connKey{}); got != nil {
  6086  				t.Errorf("in ConnContext, unexpected context key = %#v", got)
  6087  			}
  6088  			return context.WithValue(ctx, connKey{}, "conn")
  6089  		}
  6090  	}).ts
  6091  
  6092  	var res *Response
  6093  	var err error
  6094  
  6095  	res, err = ts.Client().Get(ts.URL)
  6096  	if err != nil {
  6097  		t.Fatal(err)
  6098  	}
  6099  	res.Body.Close()
  6100  
  6101  	res, err = ts.Client().Get(ts.URL)
  6102  	if err != nil {
  6103  		t.Fatal(err)
  6104  	}
  6105  	res.Body.Close()
  6106  }
  6107  
  6108  // Issue 30710: ensure that as per the spec, a server responds
  6109  // with 501 Not Implemented for unsupported transfer-encodings.
  6110  func TestUnsupportedTransferEncodingsReturn501(t *testing.T) {
  6111  	run(t, testUnsupportedTransferEncodingsReturn501, []testMode{http1Mode})
  6112  }
  6113  func testUnsupportedTransferEncodingsReturn501(t *testing.T, mode testMode) {
  6114  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6115  		w.Write([]byte("Hello, World!"))
  6116  	})).ts
  6117  
  6118  	serverURL, err := url.Parse(cst.URL)
  6119  	if err != nil {
  6120  		t.Fatalf("Failed to parse server URL: %v", err)
  6121  	}
  6122  
  6123  	unsupportedTEs := []string{
  6124  		"fugazi",
  6125  		"foo-bar",
  6126  		"unknown",
  6127  		`" chunked"`,
  6128  	}
  6129  
  6130  	for _, badTE := range unsupportedTEs {
  6131  		http1ReqBody := fmt.Sprintf(""+
  6132  			"POST / HTTP/1.1\r\nConnection: close\r\n"+
  6133  			"Host: localhost\r\nTransfer-Encoding: %s\r\n\r\n", badTE)
  6134  
  6135  		gotBody, err := fetchWireResponse(serverURL.Host, []byte(http1ReqBody))
  6136  		if err != nil {
  6137  			t.Errorf("%q. unexpected error: %v", badTE, err)
  6138  			continue
  6139  		}
  6140  
  6141  		wantBody := fmt.Sprintf("" +
  6142  			"HTTP/1.1 501 Not Implemented\r\nContent-Type: text/plain; charset=utf-8\r\n" +
  6143  			"Connection: close\r\n\r\nUnsupported transfer encoding")
  6144  
  6145  		if string(gotBody) != wantBody {
  6146  			t.Errorf("%q. body\ngot\n%q\nwant\n%q", badTE, gotBody, wantBody)
  6147  		}
  6148  	}
  6149  }
  6150  
  6151  // Issue 31753: don't sniff when Content-Encoding is set
  6152  func TestContentEncodingNoSniffing(t *testing.T) { run(t, testContentEncodingNoSniffing) }
  6153  func testContentEncodingNoSniffing(t *testing.T, mode testMode) {
  6154  	type setting struct {
  6155  		name string
  6156  		body []byte
  6157  
  6158  		// setting contentEncoding as an interface instead of a string
  6159  		// directly, so as to differentiate between 3 states:
  6160  		//    unset, empty string "" and set string "foo/bar".
  6161  		contentEncoding any
  6162  		wantContentType string
  6163  	}
  6164  
  6165  	settings := []*setting{
  6166  		{
  6167  			name:            "gzip content-encoding, gzipped", // don't sniff.
  6168  			contentEncoding: "application/gzip",
  6169  			wantContentType: "",
  6170  			body: func() []byte {
  6171  				buf := new(bytes.Buffer)
  6172  				gzw := gzip.NewWriter(buf)
  6173  				gzw.Write([]byte("doctype html><p>Hello</p>"))
  6174  				gzw.Close()
  6175  				return buf.Bytes()
  6176  			}(),
  6177  		},
  6178  		{
  6179  			name:            "zlib content-encoding, zlibbed", // don't sniff.
  6180  			contentEncoding: "application/zlib",
  6181  			wantContentType: "",
  6182  			body: func() []byte {
  6183  				buf := new(bytes.Buffer)
  6184  				zw := zlib.NewWriter(buf)
  6185  				zw.Write([]byte("doctype html><p>Hello</p>"))
  6186  				zw.Close()
  6187  				return buf.Bytes()
  6188  			}(),
  6189  		},
  6190  		{
  6191  			name:            "no content-encoding", // must sniff.
  6192  			wantContentType: "application/x-gzip",
  6193  			body: func() []byte {
  6194  				buf := new(bytes.Buffer)
  6195  				gzw := gzip.NewWriter(buf)
  6196  				gzw.Write([]byte("doctype html><p>Hello</p>"))
  6197  				gzw.Close()
  6198  				return buf.Bytes()
  6199  			}(),
  6200  		},
  6201  		{
  6202  			name:            "phony content-encoding", // don't sniff.
  6203  			contentEncoding: "foo/bar",
  6204  			body:            []byte("doctype html><p>Hello</p>"),
  6205  		},
  6206  		{
  6207  			name:            "empty but set content-encoding",
  6208  			contentEncoding: "",
  6209  			wantContentType: "audio/mpeg",
  6210  			body:            []byte("ID3"),
  6211  		},
  6212  	}
  6213  
  6214  	for _, tt := range settings {
  6215  		t.Run(tt.name, func(t *testing.T) {
  6216  			cst := newClientServerTest(t, mode, HandlerFunc(func(rw ResponseWriter, r *Request) {
  6217  				if tt.contentEncoding != nil {
  6218  					rw.Header().Set("Content-Encoding", tt.contentEncoding.(string))
  6219  				}
  6220  				rw.Write(tt.body)
  6221  			}))
  6222  
  6223  			res, err := cst.c.Get(cst.ts.URL)
  6224  			if err != nil {
  6225  				t.Fatalf("Failed to fetch URL: %v", err)
  6226  			}
  6227  			defer res.Body.Close()
  6228  
  6229  			if g, w := res.Header.Get("Content-Encoding"), tt.contentEncoding; g != w {
  6230  				if w != nil { // The case where contentEncoding was set explicitly.
  6231  					t.Errorf("Content-Encoding mismatch\n\tgot:  %q\n\twant: %q", g, w)
  6232  				} else if g != "" { // "" should be the equivalent when the contentEncoding is unset.
  6233  					t.Errorf("Unexpected Content-Encoding %q", g)
  6234  				}
  6235  			}
  6236  
  6237  			if g, w := res.Header.Get("Content-Type"), tt.wantContentType; g != w {
  6238  				t.Errorf("Content-Type mismatch\n\tgot:  %q\n\twant: %q", g, w)
  6239  			}
  6240  		})
  6241  	}
  6242  }
  6243  
  6244  // Issue 30803: ensure that TimeoutHandler logs spurious
  6245  // WriteHeader calls, for consistency with other Handlers.
  6246  func TestTimeoutHandlerSuperfluousLogs(t *testing.T) {
  6247  	run(t, testTimeoutHandlerSuperfluousLogs, []testMode{http1Mode})
  6248  }
  6249  func testTimeoutHandlerSuperfluousLogs(t *testing.T, mode testMode) {
  6250  	if testing.Short() {
  6251  		t.Skip("skipping in short mode")
  6252  	}
  6253  
  6254  	pc, curFile, _, _ := runtime.Caller(0)
  6255  	curFileBaseName := filepath.Base(curFile)
  6256  	testFuncName := runtime.FuncForPC(pc).Name()
  6257  
  6258  	timeoutMsg := "timed out here!"
  6259  
  6260  	tests := []struct {
  6261  		name        string
  6262  		mustTimeout bool
  6263  		wantResp    string
  6264  	}{
  6265  		{
  6266  			name:     "return before timeout",
  6267  			wantResp: "HTTP/1.1 404 Not Found\r\nContent-Length: 0\r\n\r\n",
  6268  		},
  6269  		{
  6270  			name:        "return after timeout",
  6271  			mustTimeout: true,
  6272  			wantResp: fmt.Sprintf("HTTP/1.1 503 Service Unavailable\r\nContent-Length: %d\r\n\r\n%s",
  6273  				len(timeoutMsg), timeoutMsg),
  6274  		},
  6275  	}
  6276  
  6277  	for _, tt := range tests {
  6278  		tt := tt
  6279  		t.Run(tt.name, func(t *testing.T) {
  6280  			exitHandler := make(chan bool, 1)
  6281  			defer close(exitHandler)
  6282  			lastLine := make(chan int, 1)
  6283  
  6284  			sh := HandlerFunc(func(w ResponseWriter, r *Request) {
  6285  				w.WriteHeader(404)
  6286  				w.WriteHeader(404)
  6287  				w.WriteHeader(404)
  6288  				w.WriteHeader(404)
  6289  				_, _, line, _ := runtime.Caller(0)
  6290  				lastLine <- line
  6291  				<-exitHandler
  6292  			})
  6293  
  6294  			if !tt.mustTimeout {
  6295  				exitHandler <- true
  6296  			}
  6297  
  6298  			logBuf := new(strings.Builder)
  6299  			srvLog := log.New(logBuf, "", 0)
  6300  			// When expecting to timeout, we'll keep the duration short.
  6301  			dur := 20 * time.Millisecond
  6302  			if !tt.mustTimeout {
  6303  				// Otherwise, make it arbitrarily long to reduce the risk of flakes.
  6304  				dur = 10 * time.Second
  6305  			}
  6306  			th := TimeoutHandler(sh, dur, timeoutMsg)
  6307  			cst := newClientServerTest(t, mode, th, optWithServerLog(srvLog))
  6308  			defer cst.close()
  6309  
  6310  			res, err := cst.c.Get(cst.ts.URL)
  6311  			if err != nil {
  6312  				t.Fatalf("Unexpected error: %v", err)
  6313  			}
  6314  
  6315  			// Deliberately removing the "Date" header since it is highly ephemeral
  6316  			// and will cause failure if we try to match it exactly.
  6317  			res.Header.Del("Date")
  6318  			res.Header.Del("Content-Type")
  6319  
  6320  			// Match the response.
  6321  			blob, _ := httputil.DumpResponse(res, true)
  6322  			if g, w := string(blob), tt.wantResp; g != w {
  6323  				t.Errorf("Response mismatch\nGot\n%q\n\nWant\n%q", g, w)
  6324  			}
  6325  
  6326  			// Given 4 w.WriteHeader calls, only the first one is valid
  6327  			// and the rest should be reported as the 3 spurious logs.
  6328  			logEntries := strings.Split(strings.TrimSpace(logBuf.String()), "\n")
  6329  			if g, w := len(logEntries), 3; g != w {
  6330  				blob, _ := json.MarshalIndent(logEntries, "", "  ")
  6331  				t.Fatalf("Server logs count mismatch\ngot %d, want %d\n\nGot\n%s\n", g, w, blob)
  6332  			}
  6333  
  6334  			lastSpuriousLine := <-lastLine
  6335  			firstSpuriousLine := lastSpuriousLine - 3
  6336  			// Now ensure that the regexes match exactly.
  6337  			//      "http: superfluous response.WriteHeader call from <fn>.func\d.\d (<curFile>:lastSpuriousLine-[1, 3]"
  6338  			for i, logEntry := range logEntries {
  6339  				wantLine := firstSpuriousLine + i
  6340  				pat := fmt.Sprintf("^http: superfluous response.WriteHeader call from %s.func\\d+.\\d+ \\(%s:%d\\)$",
  6341  					testFuncName, curFileBaseName, wantLine)
  6342  				re := regexp.MustCompile(pat)
  6343  				if !re.MatchString(logEntry) {
  6344  					t.Errorf("Log entry mismatch\n\t%s\ndoes not match\n\t%s", logEntry, pat)
  6345  				}
  6346  			}
  6347  		})
  6348  	}
  6349  }
  6350  
  6351  // fetchWireResponse is a helper for dialing to host,
  6352  // sending http1ReqBody as the payload and retrieving
  6353  // the response as it was sent on the wire.
  6354  func fetchWireResponse(host string, http1ReqBody []byte) ([]byte, error) {
  6355  	conn, err := net.Dial("tcp", host)
  6356  	if err != nil {
  6357  		return nil, err
  6358  	}
  6359  	defer conn.Close()
  6360  
  6361  	if _, err := conn.Write(http1ReqBody); err != nil {
  6362  		return nil, err
  6363  	}
  6364  	return io.ReadAll(conn)
  6365  }
  6366  
  6367  func BenchmarkResponseStatusLine(b *testing.B) {
  6368  	b.ReportAllocs()
  6369  	b.RunParallel(func(pb *testing.PB) {
  6370  		bw := bufio.NewWriter(io.Discard)
  6371  		var buf3 [3]byte
  6372  		for pb.Next() {
  6373  			Export_writeStatusLine(bw, true, 200, buf3[:])
  6374  		}
  6375  	})
  6376  }
  6377  
  6378  func TestDisableKeepAliveUpgrade(t *testing.T) {
  6379  	run(t, testDisableKeepAliveUpgrade, []testMode{http1Mode})
  6380  }
  6381  func testDisableKeepAliveUpgrade(t *testing.T, mode testMode) {
  6382  	if testing.Short() {
  6383  		t.Skip("skipping in short mode")
  6384  	}
  6385  
  6386  	s := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6387  		w.Header().Set("Connection", "Upgrade")
  6388  		w.Header().Set("Upgrade", "someProto")
  6389  		w.WriteHeader(StatusSwitchingProtocols)
  6390  		c, buf, err := w.(Hijacker).Hijack()
  6391  		if err != nil {
  6392  			return
  6393  		}
  6394  		defer c.Close()
  6395  
  6396  		// Copy from the *bufio.ReadWriter, which may contain buffered data.
  6397  		// Copy to the net.Conn, to avoid buffering the output.
  6398  		io.Copy(c, buf)
  6399  	}), func(ts *httptest.Server) {
  6400  		ts.Config.SetKeepAlivesEnabled(false)
  6401  	}).ts
  6402  
  6403  	cl := s.Client()
  6404  	cl.Transport.(*Transport).DisableKeepAlives = true
  6405  
  6406  	resp, err := cl.Get(s.URL)
  6407  	if err != nil {
  6408  		t.Fatalf("failed to perform request: %v", err)
  6409  	}
  6410  	defer resp.Body.Close()
  6411  
  6412  	if resp.StatusCode != StatusSwitchingProtocols {
  6413  		t.Fatalf("unexpected status code: %v", resp.StatusCode)
  6414  	}
  6415  
  6416  	rwc, ok := resp.Body.(io.ReadWriteCloser)
  6417  	if !ok {
  6418  		t.Fatalf("Response.Body is not an io.ReadWriteCloser: %T", resp.Body)
  6419  	}
  6420  
  6421  	_, err = rwc.Write([]byte("hello"))
  6422  	if err != nil {
  6423  		t.Fatalf("failed to write to body: %v", err)
  6424  	}
  6425  
  6426  	b := make([]byte, 5)
  6427  	_, err = io.ReadFull(rwc, b)
  6428  	if err != nil {
  6429  		t.Fatalf("failed to read from body: %v", err)
  6430  	}
  6431  
  6432  	if string(b) != "hello" {
  6433  		t.Fatalf("unexpected value read from body:\ngot: %q\nwant: %q", b, "hello")
  6434  	}
  6435  }
  6436  
  6437  type tlogWriter struct{ t *testing.T }
  6438  
  6439  func (w tlogWriter) Write(p []byte) (int, error) {
  6440  	w.t.Log(string(p))
  6441  	return len(p), nil
  6442  }
  6443  
  6444  func TestWriteHeaderSwitchingProtocols(t *testing.T) {
  6445  	run(t, testWriteHeaderSwitchingProtocols, []testMode{http1Mode})
  6446  }
  6447  func testWriteHeaderSwitchingProtocols(t *testing.T, mode testMode) {
  6448  	const wantBody = "want"
  6449  	const wantUpgrade = "someProto"
  6450  	ts := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6451  		w.Header().Set("Connection", "Upgrade")
  6452  		w.Header().Set("Upgrade", wantUpgrade)
  6453  		w.WriteHeader(StatusSwitchingProtocols)
  6454  		NewResponseController(w).Flush()
  6455  
  6456  		// Writing headers or the body after sending a 101 header should fail.
  6457  		w.WriteHeader(200)
  6458  		if _, err := w.Write([]byte("x")); err == nil {
  6459  			t.Errorf("Write to body after 101 Switching Protocols unexpectedly succeeded")
  6460  		}
  6461  
  6462  		c, _, err := NewResponseController(w).Hijack()
  6463  		if err != nil {
  6464  			t.Errorf("Hijack: %v", err)
  6465  			return
  6466  		}
  6467  		defer c.Close()
  6468  		if _, err := c.Write([]byte(wantBody)); err != nil {
  6469  			t.Errorf("Write to hijacked body: %v", err)
  6470  		}
  6471  	}), func(ts *httptest.Server) {
  6472  		// Don't spam log with warning about superfluous WriteHeader call.
  6473  		ts.Config.ErrorLog = log.New(tlogWriter{t}, "log: ", 0)
  6474  	}).ts
  6475  
  6476  	conn, err := net.Dial("tcp", ts.Listener.Addr().String())
  6477  	if err != nil {
  6478  		t.Fatalf("net.Dial: %v", err)
  6479  	}
  6480  	_, err = conn.Write([]byte("GET / HTTP/1.1\r\nHost: foo\r\n\r\n"))
  6481  	if err != nil {
  6482  		t.Fatalf("conn.Write: %v", err)
  6483  	}
  6484  	defer conn.Close()
  6485  
  6486  	r := bufio.NewReader(conn)
  6487  	res, err := ReadResponse(r, &Request{Method: "GET"})
  6488  	if err != nil {
  6489  		t.Fatal("ReadResponse error:", err)
  6490  	}
  6491  	if res.StatusCode != StatusSwitchingProtocols {
  6492  		t.Errorf("Response StatusCode=%v, want 101", res.StatusCode)
  6493  	}
  6494  	if got := res.Header.Get("Upgrade"); got != wantUpgrade {
  6495  		t.Errorf("Response Upgrade header = %q, want %q", got, wantUpgrade)
  6496  	}
  6497  	body, err := io.ReadAll(r)
  6498  	if err != nil {
  6499  		t.Error(err)
  6500  	}
  6501  	if string(body) != wantBody {
  6502  		t.Errorf("Response body = %q, want %q", string(body), wantBody)
  6503  	}
  6504  }
  6505  
  6506  func TestMuxRedirectRelative(t *testing.T) {
  6507  	setParallel(t)
  6508  	req, err := ReadRequest(bufio.NewReader(strings.NewReader("GET http://example.com HTTP/1.1\r\nHost: test\r\n\r\n")))
  6509  	if err != nil {
  6510  		t.Errorf("%s", err)
  6511  	}
  6512  	mux := NewServeMux()
  6513  	resp := httptest.NewRecorder()
  6514  	mux.ServeHTTP(resp, req)
  6515  	if got, want := resp.Header().Get("Location"), "/"; got != want {
  6516  		t.Errorf("Location header expected %q; got %q", want, got)
  6517  	}
  6518  	if got, want := resp.Code, StatusMovedPermanently; got != want {
  6519  		t.Errorf("Expected response code %d; got %d", want, got)
  6520  	}
  6521  }
  6522  
  6523  // TestQuerySemicolon tests the behavior of semicolons in queries. See Issue 25192.
  6524  func TestQuerySemicolon(t *testing.T) {
  6525  	t.Cleanup(func() { afterTest(t) })
  6526  
  6527  	tests := []struct {
  6528  		query              string
  6529  		xNoSemicolons      string
  6530  		xWithSemicolons    string
  6531  		expectParseFormErr bool
  6532  	}{
  6533  		{"?a=1;x=bad&x=good", "good", "bad", true},
  6534  		{"?a=1;b=bad&x=good", "good", "good", true},
  6535  		{"?a=1%3Bx=bad&x=good%3B", "good;", "good;", false},
  6536  		{"?a=1;x=good;x=bad", "", "good", true},
  6537  	}
  6538  
  6539  	run(t, func(t *testing.T, mode testMode) {
  6540  		for _, tt := range tests {
  6541  			t.Run(tt.query+"/allow=false", func(t *testing.T) {
  6542  				allowSemicolons := false
  6543  				testQuerySemicolon(t, mode, tt.query, tt.xNoSemicolons, allowSemicolons, tt.expectParseFormErr)
  6544  			})
  6545  			t.Run(tt.query+"/allow=true", func(t *testing.T) {
  6546  				allowSemicolons, expectParseFormErr := true, false
  6547  				testQuerySemicolon(t, mode, tt.query, tt.xWithSemicolons, allowSemicolons, expectParseFormErr)
  6548  			})
  6549  		}
  6550  	})
  6551  }
  6552  
  6553  func testQuerySemicolon(t *testing.T, mode testMode, query string, wantX string, allowSemicolons, expectParseFormErr bool) {
  6554  	writeBackX := func(w ResponseWriter, r *Request) {
  6555  		x := r.URL.Query().Get("x")
  6556  		if expectParseFormErr {
  6557  			if err := r.ParseForm(); err == nil || !strings.Contains(err.Error(), "semicolon") {
  6558  				t.Errorf("expected error mentioning semicolons from ParseForm, got %v", err)
  6559  			}
  6560  		} else {
  6561  			if err := r.ParseForm(); err != nil {
  6562  				t.Errorf("expected no error from ParseForm, got %v", err)
  6563  			}
  6564  		}
  6565  		if got := r.FormValue("x"); x != got {
  6566  			t.Errorf("got %q from FormValue, want %q", got, x)
  6567  		}
  6568  		fmt.Fprintf(w, "%s", x)
  6569  	}
  6570  
  6571  	h := Handler(HandlerFunc(writeBackX))
  6572  	if allowSemicolons {
  6573  		h = AllowQuerySemicolons(h)
  6574  	}
  6575  
  6576  	logBuf := &strings.Builder{}
  6577  	ts := newClientServerTest(t, mode, h, func(ts *httptest.Server) {
  6578  		ts.Config.ErrorLog = log.New(logBuf, "", 0)
  6579  	}).ts
  6580  
  6581  	req, _ := NewRequest("GET", ts.URL+query, nil)
  6582  	res, err := ts.Client().Do(req)
  6583  	if err != nil {
  6584  		t.Fatal(err)
  6585  	}
  6586  	slurp, _ := io.ReadAll(res.Body)
  6587  	res.Body.Close()
  6588  	if got, want := res.StatusCode, 200; got != want {
  6589  		t.Errorf("Status = %d; want = %d", got, want)
  6590  	}
  6591  	if got, want := string(slurp), wantX; got != want {
  6592  		t.Errorf("Body = %q; want = %q", got, want)
  6593  	}
  6594  }
  6595  
  6596  func TestMaxBytesHandler(t *testing.T) {
  6597  	setParallel(t)
  6598  	defer afterTest(t)
  6599  
  6600  	for _, maxSize := range []int64{100, 1_000, 1_000_000} {
  6601  		for _, requestSize := range []int64{100, 1_000, 1_000_000} {
  6602  			t.Run(fmt.Sprintf("max size %d request size %d", maxSize, requestSize),
  6603  				func(t *testing.T) {
  6604  					run(t, func(t *testing.T, mode testMode) {
  6605  						testMaxBytesHandler(t, mode, maxSize, requestSize)
  6606  					})
  6607  				})
  6608  		}
  6609  	}
  6610  }
  6611  
  6612  func testMaxBytesHandler(t *testing.T, mode testMode, maxSize, requestSize int64) {
  6613  	var (
  6614  		handlerN   int64
  6615  		handlerErr error
  6616  	)
  6617  	echo := HandlerFunc(func(w ResponseWriter, r *Request) {
  6618  		var buf bytes.Buffer
  6619  		handlerN, handlerErr = io.Copy(&buf, r.Body)
  6620  		io.Copy(w, &buf)
  6621  	})
  6622  
  6623  	ts := newClientServerTest(t, mode, MaxBytesHandler(echo, maxSize)).ts
  6624  	defer ts.Close()
  6625  
  6626  	c := ts.Client()
  6627  
  6628  	body := strings.Repeat("a", int(requestSize))
  6629  	var wg sync.WaitGroup
  6630  	defer wg.Wait()
  6631  	getBody := func() (io.ReadCloser, error) {
  6632  		wg.Add(1)
  6633  		body := &wgReadCloser{
  6634  			Reader: strings.NewReader(body),
  6635  			wg:     &wg,
  6636  		}
  6637  		return body, nil
  6638  	}
  6639  	reqBody, _ := getBody()
  6640  	req, err := NewRequest("POST", ts.URL, reqBody)
  6641  	if err != nil {
  6642  		reqBody.Close()
  6643  		t.Fatal(err)
  6644  	}
  6645  	req.ContentLength = int64(len(body))
  6646  	req.GetBody = getBody
  6647  	req.Header.Set("Content-Type", "text/plain")
  6648  
  6649  	var buf strings.Builder
  6650  	res, err := c.Do(req)
  6651  	if err != nil {
  6652  		t.Errorf("unexpected connection error: %v", err)
  6653  	} else {
  6654  		_, err = io.Copy(&buf, res.Body)
  6655  		res.Body.Close()
  6656  		if err != nil {
  6657  			t.Errorf("unexpected read error: %v", err)
  6658  		}
  6659  	}
  6660  	if handlerN > maxSize {
  6661  		t.Errorf("expected max request body %d; got %d", maxSize, handlerN)
  6662  	}
  6663  	if requestSize > maxSize && handlerErr == nil {
  6664  		t.Error("expected error on handler side; got nil")
  6665  	}
  6666  	if requestSize <= maxSize {
  6667  		if handlerErr != nil {
  6668  			t.Errorf("%d expected nil error on handler side; got %v", requestSize, handlerErr)
  6669  		}
  6670  		if handlerN != requestSize {
  6671  			t.Errorf("expected request of size %d; got %d", requestSize, handlerN)
  6672  		}
  6673  	}
  6674  	if buf.Len() != int(handlerN) {
  6675  		t.Errorf("expected echo of size %d; got %d", handlerN, buf.Len())
  6676  	}
  6677  }
  6678  
  6679  func TestEarlyHints(t *testing.T) {
  6680  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  6681  		h := w.Header()
  6682  		h.Add("Link", "</style.css>; rel=preload; as=style")
  6683  		h.Add("Link", "</script.js>; rel=preload; as=script")
  6684  		w.WriteHeader(StatusEarlyHints)
  6685  
  6686  		h.Add("Link", "</foo.js>; rel=preload; as=script")
  6687  		w.WriteHeader(StatusEarlyHints)
  6688  
  6689  		w.Write([]byte("stuff"))
  6690  	}))
  6691  
  6692  	got := ht.rawResponse("GET / HTTP/1.1\nHost: golang.org")
  6693  	expected := "HTTP/1.1 103 Early Hints\r\nLink: </style.css>; rel=preload; as=style\r\nLink: </script.js>; rel=preload; as=script\r\n\r\nHTTP/1.1 103 Early Hints\r\nLink: </style.css>; rel=preload; as=style\r\nLink: </script.js>; rel=preload; as=script\r\nLink: </foo.js>; rel=preload; as=script\r\n\r\nHTTP/1.1 200 OK\r\nLink: </style.css>; rel=preload; as=style\r\nLink: </script.js>; rel=preload; as=script\r\nLink: </foo.js>; rel=preload; as=script\r\nDate: " // dynamic content expected
  6694  	if !strings.Contains(got, expected) {
  6695  		t.Errorf("unexpected response; got %q; should start by %q", got, expected)
  6696  	}
  6697  }
  6698  func TestProcessing(t *testing.T) {
  6699  	ht := newHandlerTest(HandlerFunc(func(w ResponseWriter, r *Request) {
  6700  		w.WriteHeader(StatusProcessing)
  6701  		w.Write([]byte("stuff"))
  6702  	}))
  6703  
  6704  	got := ht.rawResponse("GET / HTTP/1.1\nHost: golang.org")
  6705  	expected := "HTTP/1.1 102 Processing\r\n\r\nHTTP/1.1 200 OK\r\nDate: " // dynamic content expected
  6706  	if !strings.Contains(got, expected) {
  6707  		t.Errorf("unexpected response; got %q; should start by %q", got, expected)
  6708  	}
  6709  }
  6710  
  6711  func TestParseFormCleanup(t *testing.T) { run(t, testParseFormCleanup) }
  6712  func testParseFormCleanup(t *testing.T, mode testMode) {
  6713  	if mode == http2Mode {
  6714  		t.Skip("https://go.dev/issue/20253")
  6715  	}
  6716  
  6717  	const maxMemory = 1024
  6718  	const key = "file"
  6719  
  6720  	if runtime.GOOS == "windows" {
  6721  		// Windows sometimes refuses to remove a file that was just closed.
  6722  		t.Skip("https://go.dev/issue/25965")
  6723  	}
  6724  
  6725  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6726  		r.ParseMultipartForm(maxMemory)
  6727  		f, _, err := r.FormFile(key)
  6728  		if err != nil {
  6729  			t.Errorf("r.FormFile(%q) = %v", key, err)
  6730  			return
  6731  		}
  6732  		of, ok := f.(*os.File)
  6733  		if !ok {
  6734  			t.Errorf("r.FormFile(%q) returned type %T, want *os.File", key, f)
  6735  			return
  6736  		}
  6737  		w.Write([]byte(of.Name()))
  6738  	}))
  6739  
  6740  	fBuf := new(bytes.Buffer)
  6741  	mw := multipart.NewWriter(fBuf)
  6742  	mf, err := mw.CreateFormFile(key, "myfile.txt")
  6743  	if err != nil {
  6744  		t.Fatal(err)
  6745  	}
  6746  	if _, err := mf.Write(bytes.Repeat([]byte("A"), maxMemory*2)); err != nil {
  6747  		t.Fatal(err)
  6748  	}
  6749  	if err := mw.Close(); err != nil {
  6750  		t.Fatal(err)
  6751  	}
  6752  	req, err := NewRequest("POST", cst.ts.URL, fBuf)
  6753  	if err != nil {
  6754  		t.Fatal(err)
  6755  	}
  6756  	req.Header.Set("Content-Type", mw.FormDataContentType())
  6757  	res, err := cst.c.Do(req)
  6758  	if err != nil {
  6759  		t.Fatal(err)
  6760  	}
  6761  	defer res.Body.Close()
  6762  	fname, err := io.ReadAll(res.Body)
  6763  	if err != nil {
  6764  		t.Fatal(err)
  6765  	}
  6766  	cst.close()
  6767  	if _, err := os.Stat(string(fname)); !errors.Is(err, os.ErrNotExist) {
  6768  		t.Errorf("file %q exists after HTTP handler returned", string(fname))
  6769  	}
  6770  }
  6771  
  6772  func TestHeadBody(t *testing.T) {
  6773  	const identityMode = false
  6774  	const chunkedMode = true
  6775  	run(t, func(t *testing.T, mode testMode) {
  6776  		t.Run("identity", func(t *testing.T) { testHeadBody(t, mode, identityMode, "HEAD") })
  6777  		t.Run("chunked", func(t *testing.T) { testHeadBody(t, mode, chunkedMode, "HEAD") })
  6778  	})
  6779  }
  6780  
  6781  func TestGetBody(t *testing.T) {
  6782  	const identityMode = false
  6783  	const chunkedMode = true
  6784  	run(t, func(t *testing.T, mode testMode) {
  6785  		t.Run("identity", func(t *testing.T) { testHeadBody(t, mode, identityMode, "GET") })
  6786  		t.Run("chunked", func(t *testing.T) { testHeadBody(t, mode, chunkedMode, "GET") })
  6787  	})
  6788  }
  6789  
  6790  func testHeadBody(t *testing.T, mode testMode, chunked bool, method string) {
  6791  	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6792  		b, err := io.ReadAll(r.Body)
  6793  		if err != nil {
  6794  			t.Errorf("server reading body: %v", err)
  6795  			return
  6796  		}
  6797  		w.Header().Set("X-Request-Body", string(b))
  6798  		w.Header().Set("Content-Length", "0")
  6799  	}))
  6800  	defer cst.close()
  6801  	for _, reqBody := range []string{
  6802  		"",
  6803  		"",
  6804  		"request_body",
  6805  		"",
  6806  	} {
  6807  		var bodyReader io.Reader
  6808  		if reqBody != "" {
  6809  			bodyReader = strings.NewReader(reqBody)
  6810  			if chunked {
  6811  				bodyReader = bufio.NewReader(bodyReader)
  6812  			}
  6813  		}
  6814  		req, err := NewRequest(method, cst.ts.URL, bodyReader)
  6815  		if err != nil {
  6816  			t.Fatal(err)
  6817  		}
  6818  		res, err := cst.c.Do(req)
  6819  		if err != nil {
  6820  			t.Fatal(err)
  6821  		}
  6822  		res.Body.Close()
  6823  		if got, want := res.StatusCode, 200; got != want {
  6824  			t.Errorf("%v request with %d-byte body: StatusCode = %v, want %v", method, len(reqBody), got, want)
  6825  		}
  6826  		if got, want := res.Header.Get("X-Request-Body"), reqBody; got != want {
  6827  			t.Errorf("%v request with %d-byte body: handler read body %q, want %q", method, len(reqBody), got, want)
  6828  		}
  6829  	}
  6830  }
  6831  
  6832  // TestDisableContentLength verifies that the Content-Length is set by default
  6833  // or disabled when the header is set to nil.
  6834  func TestDisableContentLength(t *testing.T) { run(t, testDisableContentLength) }
  6835  func testDisableContentLength(t *testing.T, mode testMode) {
  6836  	if mode == http2Mode {
  6837  		t.Skip("skipping until h2_bundle.go is updated; see https://go-review.googlesource.com/c/net/+/471535")
  6838  	}
  6839  
  6840  	noCL := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6841  		w.Header()["Content-Length"] = nil // disable the default Content-Length response
  6842  		fmt.Fprintf(w, "OK")
  6843  	}))
  6844  
  6845  	res, err := noCL.c.Get(noCL.ts.URL)
  6846  	if err != nil {
  6847  		t.Fatal(err)
  6848  	}
  6849  	if got, haveCL := res.Header["Content-Length"]; haveCL {
  6850  		t.Errorf("Unexpected Content-Length: %q", got)
  6851  	}
  6852  	if err := res.Body.Close(); err != nil {
  6853  		t.Fatal(err)
  6854  	}
  6855  
  6856  	withCL := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
  6857  		fmt.Fprintf(w, "OK")
  6858  	}))
  6859  
  6860  	res, err = withCL.c.Get(withCL.ts.URL)
  6861  	if err != nil {
  6862  		t.Fatal(err)
  6863  	}
  6864  	if got := res.Header.Get("Content-Length"); got != "2" {
  6865  		t.Errorf("Content-Length: %q; want 2", got)
  6866  	}
  6867  	if err := res.Body.Close(); err != nil {
  6868  		t.Fatal(err)
  6869  	}
  6870  }
  6871  

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