Source file src/net/http/request.go
1 // Copyright 2009 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 // HTTP Request reading and parsing. 6 7 package http 8 9 import ( 10 "bufio" 11 "bytes" 12 "context" 13 "crypto/tls" 14 "encoding/base64" 15 "errors" 16 "fmt" 17 "io" 18 "mime" 19 "mime/multipart" 20 "net" 21 "net/http/httptrace" 22 "net/http/internal/ascii" 23 "net/textproto" 24 "net/url" 25 urlpkg "net/url" 26 "strconv" 27 "strings" 28 "sync" 29 30 "golang.org/x/net/idna" 31 ) 32 33 const ( 34 defaultMaxMemory = 32 << 20 // 32 MB 35 ) 36 37 // ErrMissingFile is returned by FormFile when the provided file field name 38 // is either not present in the request or not a file field. 39 var ErrMissingFile = errors.New("http: no such file") 40 41 // ProtocolError represents an HTTP protocol error. 42 // 43 // Deprecated: Not all errors in the http package related to protocol errors 44 // are of type ProtocolError. 45 type ProtocolError struct { 46 ErrorString string 47 } 48 49 func (pe *ProtocolError) Error() string { return pe.ErrorString } 50 51 var ( 52 // ErrNotSupported is returned by the Push method of Pusher 53 // implementations to indicate that HTTP/2 Push support is not 54 // available. 55 ErrNotSupported = &ProtocolError{"feature not supported"} 56 57 // Deprecated: ErrUnexpectedTrailer is no longer returned by 58 // anything in the net/http package. Callers should not 59 // compare errors against this variable. 60 ErrUnexpectedTrailer = &ProtocolError{"trailer header without chunked transfer encoding"} 61 62 // ErrMissingBoundary is returned by Request.MultipartReader when the 63 // request's Content-Type does not include a "boundary" parameter. 64 ErrMissingBoundary = &ProtocolError{"no multipart boundary param in Content-Type"} 65 66 // ErrNotMultipart is returned by Request.MultipartReader when the 67 // request's Content-Type is not multipart/form-data. 68 ErrNotMultipart = &ProtocolError{"request Content-Type isn't multipart/form-data"} 69 70 // Deprecated: ErrHeaderTooLong is no longer returned by 71 // anything in the net/http package. Callers should not 72 // compare errors against this variable. 73 ErrHeaderTooLong = &ProtocolError{"header too long"} 74 75 // Deprecated: ErrShortBody is no longer returned by 76 // anything in the net/http package. Callers should not 77 // compare errors against this variable. 78 ErrShortBody = &ProtocolError{"entity body too short"} 79 80 // Deprecated: ErrMissingContentLength is no longer returned by 81 // anything in the net/http package. Callers should not 82 // compare errors against this variable. 83 ErrMissingContentLength = &ProtocolError{"missing ContentLength in HEAD response"} 84 ) 85 86 func badStringError(what, val string) error { return fmt.Errorf("%s %q", what, val) } 87 88 // Headers that Request.Write handles itself and should be skipped. 89 var reqWriteExcludeHeader = map[string]bool{ 90 "Host": true, // not in Header map anyway 91 "User-Agent": true, 92 "Content-Length": true, 93 "Transfer-Encoding": true, 94 "Trailer": true, 95 } 96 97 // A Request represents an HTTP request received by a server 98 // or to be sent by a client. 99 // 100 // The field semantics differ slightly between client and server 101 // usage. In addition to the notes on the fields below, see the 102 // documentation for Request.Write and RoundTripper. 103 type Request struct { 104 // Method specifies the HTTP method (GET, POST, PUT, etc.). 105 // For client requests, an empty string means GET. 106 // 107 // Go's HTTP client does not support sending a request with 108 // the CONNECT method. See the documentation on Transport for 109 // details. 110 Method string 111 112 // URL specifies either the URI being requested (for server 113 // requests) or the URL to access (for client requests). 114 // 115 // For server requests, the URL is parsed from the URI 116 // supplied on the Request-Line as stored in RequestURI. For 117 // most requests, fields other than Path and RawQuery will be 118 // empty. (See RFC 7230, Section 5.3) 119 // 120 // For client requests, the URL's Host specifies the server to 121 // connect to, while the Request's Host field optionally 122 // specifies the Host header value to send in the HTTP 123 // request. 124 URL *url.URL 125 126 // The protocol version for incoming server requests. 127 // 128 // For client requests, these fields are ignored. The HTTP 129 // client code always uses either HTTP/1.1 or HTTP/2. 130 // See the docs on Transport for details. 131 Proto string // "HTTP/1.0" 132 ProtoMajor int // 1 133 ProtoMinor int // 0 134 135 // Header contains the request header fields either received 136 // by the server or to be sent by the client. 137 // 138 // If a server received a request with header lines, 139 // 140 // Host: example.com 141 // accept-encoding: gzip, deflate 142 // Accept-Language: en-us 143 // fOO: Bar 144 // foo: two 145 // 146 // then 147 // 148 // Header = map[string][]string{ 149 // "Accept-Encoding": {"gzip, deflate"}, 150 // "Accept-Language": {"en-us"}, 151 // "Foo": {"Bar", "two"}, 152 // } 153 // 154 // For incoming requests, the Host header is promoted to the 155 // Request.Host field and removed from the Header map. 156 // 157 // HTTP defines that header names are case-insensitive. The 158 // request parser implements this by using CanonicalHeaderKey, 159 // making the first character and any characters following a 160 // hyphen uppercase and the rest lowercase. 161 // 162 // For client requests, certain headers such as Content-Length 163 // and Connection are automatically written when needed and 164 // values in Header may be ignored. See the documentation 165 // for the Request.Write method. 166 Header Header 167 168 // Body is the request's body. 169 // 170 // For client requests, a nil body means the request has no 171 // body, such as a GET request. The HTTP Client's Transport 172 // is responsible for calling the Close method. 173 // 174 // For server requests, the Request Body is always non-nil 175 // but will return EOF immediately when no body is present. 176 // The Server will close the request body. The ServeHTTP 177 // Handler does not need to. 178 // 179 // Body must allow Read to be called concurrently with Close. 180 // In particular, calling Close should unblock a Read waiting 181 // for input. 182 Body io.ReadCloser 183 184 // GetBody defines an optional func to return a new copy of 185 // Body. It is used for client requests when a redirect requires 186 // reading the body more than once. Use of GetBody still 187 // requires setting Body. 188 // 189 // For server requests, it is unused. 190 GetBody func() (io.ReadCloser, error) 191 192 // ContentLength records the length of the associated content. 193 // The value -1 indicates that the length is unknown. 194 // Values >= 0 indicate that the given number of bytes may 195 // be read from Body. 196 // 197 // For client requests, a value of 0 with a non-nil Body is 198 // also treated as unknown. 199 ContentLength int64 200 201 // TransferEncoding lists the transfer encodings from outermost to 202 // innermost. An empty list denotes the "identity" encoding. 203 // TransferEncoding can usually be ignored; chunked encoding is 204 // automatically added and removed as necessary when sending and 205 // receiving requests. 206 TransferEncoding []string 207 208 // Close indicates whether to close the connection after 209 // replying to this request (for servers) or after sending this 210 // request and reading its response (for clients). 211 // 212 // For server requests, the HTTP server handles this automatically 213 // and this field is not needed by Handlers. 214 // 215 // For client requests, setting this field prevents re-use of 216 // TCP connections between requests to the same hosts, as if 217 // Transport.DisableKeepAlives were set. 218 Close bool 219 220 // For server requests, Host specifies the host on which the 221 // URL is sought. For HTTP/1 (per RFC 7230, section 5.4), this 222 // is either the value of the "Host" header or the host name 223 // given in the URL itself. For HTTP/2, it is the value of the 224 // ":authority" pseudo-header field. 225 // It may be of the form "host:port". For international domain 226 // names, Host may be in Punycode or Unicode form. Use 227 // golang.org/x/net/idna to convert it to either format if 228 // needed. 229 // To prevent DNS rebinding attacks, server Handlers should 230 // validate that the Host header has a value for which the 231 // Handler considers itself authoritative. The included 232 // ServeMux supports patterns registered to particular host 233 // names and thus protects its registered Handlers. 234 // 235 // For client requests, Host optionally overrides the Host 236 // header to send. If empty, the Request.Write method uses 237 // the value of URL.Host. Host may contain an international 238 // domain name. 239 Host string 240 241 // Form contains the parsed form data, including both the URL 242 // field's query parameters and the PATCH, POST, or PUT form data. 243 // This field is only available after ParseForm is called. 244 // The HTTP client ignores Form and uses Body instead. 245 Form url.Values 246 247 // PostForm contains the parsed form data from PATCH, POST 248 // or PUT body parameters. 249 // 250 // This field is only available after ParseForm is called. 251 // The HTTP client ignores PostForm and uses Body instead. 252 PostForm url.Values 253 254 // MultipartForm is the parsed multipart form, including file uploads. 255 // This field is only available after ParseMultipartForm is called. 256 // The HTTP client ignores MultipartForm and uses Body instead. 257 MultipartForm *multipart.Form 258 259 // Trailer specifies additional headers that are sent after the request 260 // body. 261 // 262 // For server requests, the Trailer map initially contains only the 263 // trailer keys, with nil values. (The client declares which trailers it 264 // will later send.) While the handler is reading from Body, it must 265 // not reference Trailer. After reading from Body returns EOF, Trailer 266 // can be read again and will contain non-nil values, if they were sent 267 // by the client. 268 // 269 // For client requests, Trailer must be initialized to a map containing 270 // the trailer keys to later send. The values may be nil or their final 271 // values. The ContentLength must be 0 or -1, to send a chunked request. 272 // After the HTTP request is sent the map values can be updated while 273 // the request body is read. Once the body returns EOF, the caller must 274 // not mutate Trailer. 275 // 276 // Few HTTP clients, servers, or proxies support HTTP trailers. 277 Trailer Header 278 279 // RemoteAddr allows HTTP servers and other software to record 280 // the network address that sent the request, usually for 281 // logging. This field is not filled in by ReadRequest and 282 // has no defined format. The HTTP server in this package 283 // sets RemoteAddr to an "IP:port" address before invoking a 284 // handler. 285 // This field is ignored by the HTTP client. 286 RemoteAddr string 287 288 // RequestURI is the unmodified request-target of the 289 // Request-Line (RFC 7230, Section 3.1.1) as sent by the client 290 // to a server. Usually the URL field should be used instead. 291 // It is an error to set this field in an HTTP client request. 292 RequestURI string 293 294 // TLS allows HTTP servers and other software to record 295 // information about the TLS connection on which the request 296 // was received. This field is not filled in by ReadRequest. 297 // The HTTP server in this package sets the field for 298 // TLS-enabled connections before invoking a handler; 299 // otherwise it leaves the field nil. 300 // This field is ignored by the HTTP client. 301 TLS *tls.ConnectionState 302 303 // Cancel is an optional channel whose closure indicates that the client 304 // request should be regarded as canceled. Not all implementations of 305 // RoundTripper may support Cancel. 306 // 307 // For server requests, this field is not applicable. 308 // 309 // Deprecated: Set the Request's context with NewRequestWithContext 310 // instead. If a Request's Cancel field and context are both 311 // set, it is undefined whether Cancel is respected. 312 Cancel <-chan struct{} 313 314 // Response is the redirect response which caused this request 315 // to be created. This field is only populated during client 316 // redirects. 317 Response *Response 318 319 // ctx is either the client or server context. It should only 320 // be modified via copying the whole Request using WithContext. 321 // It is unexported to prevent people from using Context wrong 322 // and mutating the contexts held by callers of the same request. 323 ctx context.Context 324 } 325 326 // Context returns the request's context. To change the context, use 327 // WithContext. 328 // 329 // The returned context is always non-nil; it defaults to the 330 // background context. 331 // 332 // For outgoing client requests, the context controls cancellation. 333 // 334 // For incoming server requests, the context is canceled when the 335 // client's connection closes, the request is canceled (with HTTP/2), 336 // or when the ServeHTTP method returns. 337 func (r *Request) Context() context.Context { 338 if r.ctx != nil { 339 return r.ctx 340 } 341 return context.Background() 342 } 343 344 // WithContext returns a shallow copy of r with its context changed 345 // to ctx. The provided ctx must be non-nil. 346 // 347 // For outgoing client request, the context controls the entire 348 // lifetime of a request and its response: obtaining a connection, 349 // sending the request, and reading the response headers and body. 350 // 351 // To create a new request with a context, use NewRequestWithContext. 352 // To change the context of a request, such as an incoming request you 353 // want to modify before sending back out, use Request.Clone. Between 354 // those two uses, it's rare to need WithContext. 355 func (r *Request) WithContext(ctx context.Context) *Request { 356 if ctx == nil { 357 panic("nil context") 358 } 359 r2 := new(Request) 360 *r2 = *r 361 r2.ctx = ctx 362 r2.URL = cloneURL(r.URL) // legacy behavior; TODO: try to remove. Issue 23544 363 return r2 364 } 365 366 // Clone returns a deep copy of r with its context changed to ctx. 367 // The provided ctx must be non-nil. 368 // 369 // For an outgoing client request, the context controls the entire 370 // lifetime of a request and its response: obtaining a connection, 371 // sending the request, and reading the response headers and body. 372 func (r *Request) Clone(ctx context.Context) *Request { 373 if ctx == nil { 374 panic("nil context") 375 } 376 r2 := new(Request) 377 *r2 = *r 378 r2.ctx = ctx 379 r2.URL = cloneURL(r.URL) 380 if r.Header != nil { 381 r2.Header = r.Header.Clone() 382 } 383 if r.Trailer != nil { 384 r2.Trailer = r.Trailer.Clone() 385 } 386 if s := r.TransferEncoding; s != nil { 387 s2 := make([]string, len(s)) 388 copy(s2, s) 389 r2.TransferEncoding = s2 390 } 391 r2.Form = cloneURLValues(r.Form) 392 r2.PostForm = cloneURLValues(r.PostForm) 393 r2.MultipartForm = cloneMultipartForm(r.MultipartForm) 394 return r2 395 } 396 397 // ProtoAtLeast reports whether the HTTP protocol used 398 // in the request is at least major.minor. 399 func (r *Request) ProtoAtLeast(major, minor int) bool { 400 return r.ProtoMajor > major || 401 r.ProtoMajor == major && r.ProtoMinor >= minor 402 } 403 404 // UserAgent returns the client's User-Agent, if sent in the request. 405 func (r *Request) UserAgent() string { 406 return r.Header.Get("User-Agent") 407 } 408 409 // Cookies parses and returns the HTTP cookies sent with the request. 410 func (r *Request) Cookies() []*Cookie { 411 return readCookies(r.Header, "") 412 } 413 414 // ErrNoCookie is returned by Request's Cookie method when a cookie is not found. 415 var ErrNoCookie = errors.New("http: named cookie not present") 416 417 // Cookie returns the named cookie provided in the request or 418 // ErrNoCookie if not found. 419 // If multiple cookies match the given name, only one cookie will 420 // be returned. 421 func (r *Request) Cookie(name string) (*Cookie, error) { 422 for _, c := range readCookies(r.Header, name) { 423 return c, nil 424 } 425 return nil, ErrNoCookie 426 } 427 428 // AddCookie adds a cookie to the request. Per RFC 6265 section 5.4, 429 // AddCookie does not attach more than one Cookie header field. That 430 // means all cookies, if any, are written into the same line, 431 // separated by semicolon. 432 // AddCookie only sanitizes c's name and value, and does not sanitize 433 // a Cookie header already present in the request. 434 func (r *Request) AddCookie(c *Cookie) { 435 s := fmt.Sprintf("%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value)) 436 if c := r.Header.Get("Cookie"); c != "" { 437 r.Header.Set("Cookie", c+"; "+s) 438 } else { 439 r.Header.Set("Cookie", s) 440 } 441 } 442 443 // Referer returns the referring URL, if sent in the request. 444 // 445 // Referer is misspelled as in the request itself, a mistake from the 446 // earliest days of HTTP. This value can also be fetched from the 447 // Header map as Header["Referer"]; the benefit of making it available 448 // as a method is that the compiler can diagnose programs that use the 449 // alternate (correct English) spelling req.Referrer() but cannot 450 // diagnose programs that use Header["Referrer"]. 451 func (r *Request) Referer() string { 452 return r.Header.Get("Referer") 453 } 454 455 // multipartByReader is a sentinel value. 456 // Its presence in Request.MultipartForm indicates that parsing of the request 457 // body has been handed off to a MultipartReader instead of ParseMultipartForm. 458 var multipartByReader = &multipart.Form{ 459 Value: make(map[string][]string), 460 File: make(map[string][]*multipart.FileHeader), 461 } 462 463 // MultipartReader returns a MIME multipart reader if this is a 464 // multipart/form-data or a multipart/mixed POST request, else returns nil and an error. 465 // Use this function instead of ParseMultipartForm to 466 // process the request body as a stream. 467 func (r *Request) MultipartReader() (*multipart.Reader, error) { 468 if r.MultipartForm == multipartByReader { 469 return nil, errors.New("http: MultipartReader called twice") 470 } 471 if r.MultipartForm != nil { 472 return nil, errors.New("http: multipart handled by ParseMultipartForm") 473 } 474 r.MultipartForm = multipartByReader 475 return r.multipartReader(true) 476 } 477 478 func (r *Request) multipartReader(allowMixed bool) (*multipart.Reader, error) { 479 v := r.Header.Get("Content-Type") 480 if v == "" { 481 return nil, ErrNotMultipart 482 } 483 d, params, err := mime.ParseMediaType(v) 484 if err != nil || !(d == "multipart/form-data" || allowMixed && d == "multipart/mixed") { 485 return nil, ErrNotMultipart 486 } 487 boundary, ok := params["boundary"] 488 if !ok { 489 return nil, ErrMissingBoundary 490 } 491 return multipart.NewReader(r.Body, boundary), nil 492 } 493 494 // isH2Upgrade reports whether r represents the http2 "client preface" 495 // magic string. 496 func (r *Request) isH2Upgrade() bool { 497 return r.Method == "PRI" && len(r.Header) == 0 && r.URL.Path == "*" && r.Proto == "HTTP/2.0" 498 } 499 500 // Return value if nonempty, def otherwise. 501 func valueOrDefault(value, def string) string { 502 if value != "" { 503 return value 504 } 505 return def 506 } 507 508 // NOTE: This is not intended to reflect the actual Go version being used. 509 // It was changed at the time of Go 1.1 release because the former User-Agent 510 // had ended up blocked by some intrusion detection systems. 511 // See https://codereview.appspot.com/7532043. 512 const defaultUserAgent = "Go-http-client/1.1" 513 514 // Write writes an HTTP/1.1 request, which is the header and body, in wire format. 515 // This method consults the following fields of the request: 516 // Host 517 // URL 518 // Method (defaults to "GET") 519 // Header 520 // ContentLength 521 // TransferEncoding 522 // Body 523 // 524 // If Body is present, Content-Length is <= 0 and TransferEncoding 525 // hasn't been set to "identity", Write adds "Transfer-Encoding: 526 // chunked" to the header. Body is closed after it is sent. 527 func (r *Request) Write(w io.Writer) error { 528 return r.write(w, false, nil, nil) 529 } 530 531 // WriteProxy is like Write but writes the request in the form 532 // expected by an HTTP proxy. In particular, WriteProxy writes the 533 // initial Request-URI line of the request with an absolute URI, per 534 // section 5.3 of RFC 7230, including the scheme and host. 535 // In either case, WriteProxy also writes a Host header, using 536 // either r.Host or r.URL.Host. 537 func (r *Request) WriteProxy(w io.Writer) error { 538 return r.write(w, true, nil, nil) 539 } 540 541 // errMissingHost is returned by Write when there is no Host or URL present in 542 // the Request. 543 var errMissingHost = errors.New("http: Request.Write on Request with no Host or URL set") 544 545 // extraHeaders may be nil 546 // waitForContinue may be nil 547 // always closes body 548 func (r *Request) write(w io.Writer, usingProxy bool, extraHeaders Header, waitForContinue func() bool) (err error) { 549 trace := httptrace.ContextClientTrace(r.Context()) 550 if trace != nil && trace.WroteRequest != nil { 551 defer func() { 552 trace.WroteRequest(httptrace.WroteRequestInfo{ 553 Err: err, 554 }) 555 }() 556 } 557 closed := false 558 defer func() { 559 if closed { 560 return 561 } 562 if closeErr := r.closeBody(); closeErr != nil && err == nil { 563 err = closeErr 564 } 565 }() 566 567 // Find the target host. Prefer the Host: header, but if that 568 // is not given, use the host from the request URL. 569 // 570 // Clean the host, in case it arrives with unexpected stuff in it. 571 host := cleanHost(r.Host) 572 if host == "" { 573 if r.URL == nil { 574 return errMissingHost 575 } 576 host = cleanHost(r.URL.Host) 577 } 578 579 // According to RFC 6874, an HTTP client, proxy, or other 580 // intermediary must remove any IPv6 zone identifier attached 581 // to an outgoing URI. 582 host = removeZone(host) 583 584 ruri := r.URL.RequestURI() 585 if usingProxy && r.URL.Scheme != "" && r.URL.Opaque == "" { 586 ruri = r.URL.Scheme + "://" + host + ruri 587 } else if r.Method == "CONNECT" && r.URL.Path == "" { 588 // CONNECT requests normally give just the host and port, not a full URL. 589 ruri = host 590 if r.URL.Opaque != "" { 591 ruri = r.URL.Opaque 592 } 593 } 594 if stringContainsCTLByte(ruri) { 595 return errors.New("net/http: can't write control character in Request.URL") 596 } 597 // TODO: validate r.Method too? At least it's less likely to 598 // come from an attacker (more likely to be a constant in 599 // code). 600 601 // Wrap the writer in a bufio Writer if it's not already buffered. 602 // Don't always call NewWriter, as that forces a bytes.Buffer 603 // and other small bufio Writers to have a minimum 4k buffer 604 // size. 605 var bw *bufio.Writer 606 if _, ok := w.(io.ByteWriter); !ok { 607 bw = bufio.NewWriter(w) 608 w = bw 609 } 610 611 _, err = fmt.Fprintf(w, "%s %s HTTP/1.1\r\n", valueOrDefault(r.Method, "GET"), ruri) 612 if err != nil { 613 return err 614 } 615 616 // Header lines 617 _, err = fmt.Fprintf(w, "Host: %s\r\n", host) 618 if err != nil { 619 return err 620 } 621 if trace != nil && trace.WroteHeaderField != nil { 622 trace.WroteHeaderField("Host", []string{host}) 623 } 624 625 // Use the defaultUserAgent unless the Header contains one, which 626 // may be blank to not send the header. 627 userAgent := defaultUserAgent 628 if r.Header.has("User-Agent") { 629 userAgent = r.Header.Get("User-Agent") 630 } 631 if userAgent != "" { 632 _, err = fmt.Fprintf(w, "User-Agent: %s\r\n", userAgent) 633 if err != nil { 634 return err 635 } 636 if trace != nil && trace.WroteHeaderField != nil { 637 trace.WroteHeaderField("User-Agent", []string{userAgent}) 638 } 639 } 640 641 // Process Body,ContentLength,Close,Trailer 642 tw, err := newTransferWriter(r) 643 if err != nil { 644 return err 645 } 646 err = tw.writeHeader(w, trace) 647 if err != nil { 648 return err 649 } 650 651 err = r.Header.writeSubset(w, reqWriteExcludeHeader, trace) 652 if err != nil { 653 return err 654 } 655 656 if extraHeaders != nil { 657 err = extraHeaders.write(w, trace) 658 if err != nil { 659 return err 660 } 661 } 662 663 _, err = io.WriteString(w, "\r\n") 664 if err != nil { 665 return err 666 } 667 668 if trace != nil && trace.WroteHeaders != nil { 669 trace.WroteHeaders() 670 } 671 672 // Flush and wait for 100-continue if expected. 673 if waitForContinue != nil { 674 if bw, ok := w.(*bufio.Writer); ok { 675 err = bw.Flush() 676 if err != nil { 677 return err 678 } 679 } 680 if trace != nil && trace.Wait100Continue != nil { 681 trace.Wait100Continue() 682 } 683 if !waitForContinue() { 684 closed = true 685 r.closeBody() 686 return nil 687 } 688 } 689 690 if bw, ok := w.(*bufio.Writer); ok && tw.FlushHeaders { 691 if err := bw.Flush(); err != nil { 692 return err 693 } 694 } 695 696 // Write body and trailer 697 closed = true 698 err = tw.writeBody(w) 699 if err != nil { 700 if tw.bodyReadError == err { 701 err = requestBodyReadError{err} 702 } 703 return err 704 } 705 706 if bw != nil { 707 return bw.Flush() 708 } 709 return nil 710 } 711 712 // requestBodyReadError wraps an error from (*Request).write to indicate 713 // that the error came from a Read call on the Request.Body. 714 // This error type should not escape the net/http package to users. 715 type requestBodyReadError struct{ error } 716 717 func idnaASCII(v string) (string, error) { 718 // TODO: Consider removing this check after verifying performance is okay. 719 // Right now punycode verification, length checks, context checks, and the 720 // permissible character tests are all omitted. It also prevents the ToASCII 721 // call from salvaging an invalid IDN, when possible. As a result it may be 722 // possible to have two IDNs that appear identical to the user where the 723 // ASCII-only version causes an error downstream whereas the non-ASCII 724 // version does not. 725 // Note that for correct ASCII IDNs ToASCII will only do considerably more 726 // work, but it will not cause an allocation. 727 if ascii.Is(v) { 728 return v, nil 729 } 730 return idna.Lookup.ToASCII(v) 731 } 732 733 // cleanHost cleans up the host sent in request's Host header. 734 // 735 // It both strips anything after '/' or ' ', and puts the value 736 // into Punycode form, if necessary. 737 // 738 // Ideally we'd clean the Host header according to the spec: 739 // https://tools.ietf.org/html/rfc7230#section-5.4 (Host = uri-host [ ":" port ]") 740 // https://tools.ietf.org/html/rfc7230#section-2.7 (uri-host -> rfc3986's host) 741 // https://tools.ietf.org/html/rfc3986#section-3.2.2 (definition of host) 742 // But practically, what we are trying to avoid is the situation in 743 // issue 11206, where a malformed Host header used in the proxy context 744 // would create a bad request. So it is enough to just truncate at the 745 // first offending character. 746 func cleanHost(in string) string { 747 if i := strings.IndexAny(in, " /"); i != -1 { 748 in = in[:i] 749 } 750 host, port, err := net.SplitHostPort(in) 751 if err != nil { // input was just a host 752 a, err := idnaASCII(in) 753 if err != nil { 754 return in // garbage in, garbage out 755 } 756 return a 757 } 758 a, err := idnaASCII(host) 759 if err != nil { 760 return in // garbage in, garbage out 761 } 762 return net.JoinHostPort(a, port) 763 } 764 765 // removeZone removes IPv6 zone identifier from host. 766 // E.g., "[fe80::1%en0]:8080" to "[fe80::1]:8080" 767 func removeZone(host string) string { 768 if !strings.HasPrefix(host, "[") { 769 return host 770 } 771 i := strings.LastIndex(host, "]") 772 if i < 0 { 773 return host 774 } 775 j := strings.LastIndex(host[:i], "%") 776 if j < 0 { 777 return host 778 } 779 return host[:j] + host[i:] 780 } 781 782 // ParseHTTPVersion parses an HTTP version string according to RFC 7230, section 2.6. 783 // "HTTP/1.0" returns (1, 0, true). Note that strings without 784 // a minor version, such as "HTTP/2", are not valid. 785 func ParseHTTPVersion(vers string) (major, minor int, ok bool) { 786 switch vers { 787 case "HTTP/1.1": 788 return 1, 1, true 789 case "HTTP/1.0": 790 return 1, 0, true 791 } 792 if !strings.HasPrefix(vers, "HTTP/") { 793 return 0, 0, false 794 } 795 if len(vers) != len("HTTP/X.Y") { 796 return 0, 0, false 797 } 798 if vers[6] != '.' { 799 return 0, 0, false 800 } 801 maj, err := strconv.ParseUint(vers[5:6], 10, 0) 802 if err != nil { 803 return 0, 0, false 804 } 805 min, err := strconv.ParseUint(vers[7:8], 10, 0) 806 if err != nil { 807 return 0, 0, false 808 } 809 return int(maj), int(min), true 810 } 811 812 func validMethod(method string) bool { 813 /* 814 Method = "OPTIONS" ; Section 9.2 815 | "GET" ; Section 9.3 816 | "HEAD" ; Section 9.4 817 | "POST" ; Section 9.5 818 | "PUT" ; Section 9.6 819 | "DELETE" ; Section 9.7 820 | "TRACE" ; Section 9.8 821 | "CONNECT" ; Section 9.9 822 | extension-method 823 extension-method = token 824 token = 1*<any CHAR except CTLs or separators> 825 */ 826 return len(method) > 0 && strings.IndexFunc(method, isNotToken) == -1 827 } 828 829 // NewRequest wraps NewRequestWithContext using context.Background. 830 func NewRequest(method, url string, body io.Reader) (*Request, error) { 831 return NewRequestWithContext(context.Background(), method, url, body) 832 } 833 834 // NewRequestWithContext returns a new Request given a method, URL, and 835 // optional body. 836 // 837 // If the provided body is also an io.Closer, the returned 838 // Request.Body is set to body and will be closed by the Client 839 // methods Do, Post, and PostForm, and Transport.RoundTrip. 840 // 841 // NewRequestWithContext returns a Request suitable for use with 842 // Client.Do or Transport.RoundTrip. To create a request for use with 843 // testing a Server Handler, either use the NewRequest function in the 844 // net/http/httptest package, use ReadRequest, or manually update the 845 // Request fields. For an outgoing client request, the context 846 // controls the entire lifetime of a request and its response: 847 // obtaining a connection, sending the request, and reading the 848 // response headers and body. See the Request type's documentation for 849 // the difference between inbound and outbound request fields. 850 // 851 // If body is of type *bytes.Buffer, *bytes.Reader, or 852 // *strings.Reader, the returned request's ContentLength is set to its 853 // exact value (instead of -1), GetBody is populated (so 307 and 308 854 // redirects can replay the body), and Body is set to NoBody if the 855 // ContentLength is 0. 856 func NewRequestWithContext(ctx context.Context, method, url string, body io.Reader) (*Request, error) { 857 if method == "" { 858 // We document that "" means "GET" for Request.Method, and people have 859 // relied on that from NewRequest, so keep that working. 860 // We still enforce validMethod for non-empty methods. 861 method = "GET" 862 } 863 if !validMethod(method) { 864 return nil, fmt.Errorf("net/http: invalid method %q", method) 865 } 866 if ctx == nil { 867 return nil, errors.New("net/http: nil Context") 868 } 869 u, err := urlpkg.Parse(url) 870 if err != nil { 871 return nil, err 872 } 873 rc, ok := body.(io.ReadCloser) 874 if !ok && body != nil { 875 rc = io.NopCloser(body) 876 } 877 // The host's colon:port should be normalized. See Issue 14836. 878 u.Host = removeEmptyPort(u.Host) 879 req := &Request{ 880 ctx: ctx, 881 Method: method, 882 URL: u, 883 Proto: "HTTP/1.1", 884 ProtoMajor: 1, 885 ProtoMinor: 1, 886 Header: make(Header), 887 Body: rc, 888 Host: u.Host, 889 } 890 if body != nil { 891 switch v := body.(type) { 892 case *bytes.Buffer: 893 req.ContentLength = int64(v.Len()) 894 buf := v.Bytes() 895 req.GetBody = func() (io.ReadCloser, error) { 896 r := bytes.NewReader(buf) 897 return io.NopCloser(r), nil 898 } 899 case *bytes.Reader: 900 req.ContentLength = int64(v.Len()) 901 snapshot := *v 902 req.GetBody = func() (io.ReadCloser, error) { 903 r := snapshot 904 return io.NopCloser(&r), nil 905 } 906 case *strings.Reader: 907 req.ContentLength = int64(v.Len()) 908 snapshot := *v 909 req.GetBody = func() (io.ReadCloser, error) { 910 r := snapshot 911 return io.NopCloser(&r), nil 912 } 913 default: 914 // This is where we'd set it to -1 (at least 915 // if body != NoBody) to mean unknown, but 916 // that broke people during the Go 1.8 testing 917 // period. People depend on it being 0 I 918 // guess. Maybe retry later. See Issue 18117. 919 } 920 // For client requests, Request.ContentLength of 0 921 // means either actually 0, or unknown. The only way 922 // to explicitly say that the ContentLength is zero is 923 // to set the Body to nil. But turns out too much code 924 // depends on NewRequest returning a non-nil Body, 925 // so we use a well-known ReadCloser variable instead 926 // and have the http package also treat that sentinel 927 // variable to mean explicitly zero. 928 if req.GetBody != nil && req.ContentLength == 0 { 929 req.Body = NoBody 930 req.GetBody = func() (io.ReadCloser, error) { return NoBody, nil } 931 } 932 } 933 934 return req, nil 935 } 936 937 // BasicAuth returns the username and password provided in the request's 938 // Authorization header, if the request uses HTTP Basic Authentication. 939 // See RFC 2617, Section 2. 940 func (r *Request) BasicAuth() (username, password string, ok bool) { 941 auth := r.Header.Get("Authorization") 942 if auth == "" { 943 return "", "", false 944 } 945 return parseBasicAuth(auth) 946 } 947 948 // parseBasicAuth parses an HTTP Basic Authentication string. 949 // "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==" returns ("Aladdin", "open sesame", true). 950 func parseBasicAuth(auth string) (username, password string, ok bool) { 951 const prefix = "Basic " 952 // Case insensitive prefix match. See Issue 22736. 953 if len(auth) < len(prefix) || !ascii.EqualFold(auth[:len(prefix)], prefix) { 954 return "", "", false 955 } 956 c, err := base64.StdEncoding.DecodeString(auth[len(prefix):]) 957 if err != nil { 958 return "", "", false 959 } 960 cs := string(c) 961 username, password, ok = strings.Cut(cs, ":") 962 if !ok { 963 return "", "", false 964 } 965 return username, password, true 966 } 967 968 // SetBasicAuth sets the request's Authorization header to use HTTP 969 // Basic Authentication with the provided username and password. 970 // 971 // With HTTP Basic Authentication the provided username and password 972 // are not encrypted. 973 // 974 // Some protocols may impose additional requirements on pre-escaping the 975 // username and password. For instance, when used with OAuth2, both arguments 976 // must be URL encoded first with url.QueryEscape. 977 func (r *Request) SetBasicAuth(username, password string) { 978 r.Header.Set("Authorization", "Basic "+basicAuth(username, password)) 979 } 980 981 // parseRequestLine parses "GET /foo HTTP/1.1" into its three parts. 982 func parseRequestLine(line string) (method, requestURI, proto string, ok bool) { 983 method, rest, ok1 := strings.Cut(line, " ") 984 requestURI, proto, ok2 := strings.Cut(rest, " ") 985 if !ok1 || !ok2 { 986 return "", "", "", false 987 } 988 return method, requestURI, proto, true 989 } 990 991 var textprotoReaderPool sync.Pool 992 993 func newTextprotoReader(br *bufio.Reader) *textproto.Reader { 994 if v := textprotoReaderPool.Get(); v != nil { 995 tr := v.(*textproto.Reader) 996 tr.R = br 997 return tr 998 } 999 return textproto.NewReader(br) 1000 } 1001 1002 func putTextprotoReader(r *textproto.Reader) { 1003 r.R = nil 1004 textprotoReaderPool.Put(r) 1005 } 1006 1007 // ReadRequest reads and parses an incoming request from b. 1008 // 1009 // ReadRequest is a low-level function and should only be used for 1010 // specialized applications; most code should use the Server to read 1011 // requests and handle them via the Handler interface. ReadRequest 1012 // only supports HTTP/1.x requests. For HTTP/2, use golang.org/x/net/http2. 1013 func ReadRequest(b *bufio.Reader) (*Request, error) { 1014 req, err := readRequest(b) 1015 if err != nil { 1016 return nil, err 1017 } 1018 1019 delete(req.Header, "Host") 1020 return req, err 1021 } 1022 1023 func readRequest(b *bufio.Reader) (req *Request, err error) { 1024 tp := newTextprotoReader(b) 1025 req = new(Request) 1026 1027 // First line: GET /index.html HTTP/1.0 1028 var s string 1029 if s, err = tp.ReadLine(); err != nil { 1030 return nil, err 1031 } 1032 defer func() { 1033 putTextprotoReader(tp) 1034 if err == io.EOF { 1035 err = io.ErrUnexpectedEOF 1036 } 1037 }() 1038 1039 var ok bool 1040 req.Method, req.RequestURI, req.Proto, ok = parseRequestLine(s) 1041 if !ok { 1042 return nil, badStringError("malformed HTTP request", s) 1043 } 1044 if !validMethod(req.Method) { 1045 return nil, badStringError("invalid method", req.Method) 1046 } 1047 rawurl := req.RequestURI 1048 if req.ProtoMajor, req.ProtoMinor, ok = ParseHTTPVersion(req.Proto); !ok { 1049 return nil, badStringError("malformed HTTP version", req.Proto) 1050 } 1051 1052 // CONNECT requests are used two different ways, and neither uses a full URL: 1053 // The standard use is to tunnel HTTPS through an HTTP proxy. 1054 // It looks like "CONNECT www.google.com:443 HTTP/1.1", and the parameter is 1055 // just the authority section of a URL. This information should go in req.URL.Host. 1056 // 1057 // The net/rpc package also uses CONNECT, but there the parameter is a path 1058 // that starts with a slash. It can be parsed with the regular URL parser, 1059 // and the path will end up in req.URL.Path, where it needs to be in order for 1060 // RPC to work. 1061 justAuthority := req.Method == "CONNECT" && !strings.HasPrefix(rawurl, "/") 1062 if justAuthority { 1063 rawurl = "http://" + rawurl 1064 } 1065 1066 if req.URL, err = url.ParseRequestURI(rawurl); err != nil { 1067 return nil, err 1068 } 1069 1070 if justAuthority { 1071 // Strip the bogus "http://" back off. 1072 req.URL.Scheme = "" 1073 } 1074 1075 // Subsequent lines: Key: value. 1076 mimeHeader, err := tp.ReadMIMEHeader() 1077 if err != nil { 1078 return nil, err 1079 } 1080 req.Header = Header(mimeHeader) 1081 if len(req.Header["Host"]) > 1 { 1082 return nil, fmt.Errorf("too many Host headers") 1083 } 1084 1085 // RFC 7230, section 5.3: Must treat 1086 // GET /index.html HTTP/1.1 1087 // Host: www.google.com 1088 // and 1089 // GET http://www.google.com/index.html HTTP/1.1 1090 // Host: doesntmatter 1091 // the same. In the second case, any Host line is ignored. 1092 req.Host = req.URL.Host 1093 if req.Host == "" { 1094 req.Host = req.Header.get("Host") 1095 } 1096 1097 fixPragmaCacheControl(req.Header) 1098 1099 req.Close = shouldClose(req.ProtoMajor, req.ProtoMinor, req.Header, false) 1100 1101 err = readTransfer(req, b) 1102 if err != nil { 1103 return nil, err 1104 } 1105 1106 if req.isH2Upgrade() { 1107 // Because it's neither chunked, nor declared: 1108 req.ContentLength = -1 1109 1110 // We want to give handlers a chance to hijack the 1111 // connection, but we need to prevent the Server from 1112 // dealing with the connection further if it's not 1113 // hijacked. Set Close to ensure that: 1114 req.Close = true 1115 } 1116 return req, nil 1117 } 1118 1119 // MaxBytesReader is similar to io.LimitReader but is intended for 1120 // limiting the size of incoming request bodies. In contrast to 1121 // io.LimitReader, MaxBytesReader's result is a ReadCloser, returns a 1122 // non-EOF error for a Read beyond the limit, and closes the 1123 // underlying reader when its Close method is called. 1124 // 1125 // MaxBytesReader prevents clients from accidentally or maliciously 1126 // sending a large request and wasting server resources. 1127 func MaxBytesReader(w ResponseWriter, r io.ReadCloser, n int64) io.ReadCloser { 1128 if n < 0 { // Treat negative limits as equivalent to 0. 1129 n = 0 1130 } 1131 return &maxBytesReader{w: w, r: r, n: n} 1132 } 1133 1134 type maxBytesReader struct { 1135 w ResponseWriter 1136 r io.ReadCloser // underlying reader 1137 n int64 // max bytes remaining 1138 err error // sticky error 1139 } 1140 1141 func (l *maxBytesReader) Read(p []byte) (n int, err error) { 1142 if l.err != nil { 1143 return 0, l.err 1144 } 1145 if len(p) == 0 { 1146 return 0, nil 1147 } 1148 // If they asked for a 32KB byte read but only 5 bytes are 1149 // remaining, no need to read 32KB. 6 bytes will answer the 1150 // question of the whether we hit the limit or go past it. 1151 if int64(len(p)) > l.n+1 { 1152 p = p[:l.n+1] 1153 } 1154 n, err = l.r.Read(p) 1155 1156 if int64(n) <= l.n { 1157 l.n -= int64(n) 1158 l.err = err 1159 return n, err 1160 } 1161 1162 n = int(l.n) 1163 l.n = 0 1164 1165 // The server code and client code both use 1166 // maxBytesReader. This "requestTooLarge" check is 1167 // only used by the server code. To prevent binaries 1168 // which only using the HTTP Client code (such as 1169 // cmd/go) from also linking in the HTTP server, don't 1170 // use a static type assertion to the server 1171 // "*response" type. Check this interface instead: 1172 type requestTooLarger interface { 1173 requestTooLarge() 1174 } 1175 if res, ok := l.w.(requestTooLarger); ok { 1176 res.requestTooLarge() 1177 } 1178 l.err = errors.New("http: request body too large") 1179 return n, l.err 1180 } 1181 1182 func (l *maxBytesReader) Close() error { 1183 return l.r.Close() 1184 } 1185 1186 func copyValues(dst, src url.Values) { 1187 for k, vs := range src { 1188 dst[k] = append(dst[k], vs...) 1189 } 1190 } 1191 1192 func parsePostForm(r *Request) (vs url.Values, err error) { 1193 if r.Body == nil { 1194 err = errors.New("missing form body") 1195 return 1196 } 1197 ct := r.Header.Get("Content-Type") 1198 // RFC 7231, section 3.1.1.5 - empty type 1199 // MAY be treated as application/octet-stream 1200 if ct == "" { 1201 ct = "application/octet-stream" 1202 } 1203 ct, _, err = mime.ParseMediaType(ct) 1204 switch { 1205 case ct == "application/x-www-form-urlencoded": 1206 var reader io.Reader = r.Body 1207 maxFormSize := int64(1<<63 - 1) 1208 if _, ok := r.Body.(*maxBytesReader); !ok { 1209 maxFormSize = int64(10 << 20) // 10 MB is a lot of text. 1210 reader = io.LimitReader(r.Body, maxFormSize+1) 1211 } 1212 b, e := io.ReadAll(reader) 1213 if e != nil { 1214 if err == nil { 1215 err = e 1216 } 1217 break 1218 } 1219 if int64(len(b)) > maxFormSize { 1220 err = errors.New("http: POST too large") 1221 return 1222 } 1223 vs, e = url.ParseQuery(string(b)) 1224 if err == nil { 1225 err = e 1226 } 1227 case ct == "multipart/form-data": 1228 // handled by ParseMultipartForm (which is calling us, or should be) 1229 // TODO(bradfitz): there are too many possible 1230 // orders to call too many functions here. 1231 // Clean this up and write more tests. 1232 // request_test.go contains the start of this, 1233 // in TestParseMultipartFormOrder and others. 1234 } 1235 return 1236 } 1237 1238 // ParseForm populates r.Form and r.PostForm. 1239 // 1240 // For all requests, ParseForm parses the raw query from the URL and updates 1241 // r.Form. 1242 // 1243 // For POST, PUT, and PATCH requests, it also reads the request body, parses it 1244 // as a form and puts the results into both r.PostForm and r.Form. Request body 1245 // parameters take precedence over URL query string values in r.Form. 1246 // 1247 // If the request Body's size has not already been limited by MaxBytesReader, 1248 // the size is capped at 10MB. 1249 // 1250 // For other HTTP methods, or when the Content-Type is not 1251 // application/x-www-form-urlencoded, the request Body is not read, and 1252 // r.PostForm is initialized to a non-nil, empty value. 1253 // 1254 // ParseMultipartForm calls ParseForm automatically. 1255 // ParseForm is idempotent. 1256 func (r *Request) ParseForm() error { 1257 var err error 1258 if r.PostForm == nil { 1259 if r.Method == "POST" || r.Method == "PUT" || r.Method == "PATCH" { 1260 r.PostForm, err = parsePostForm(r) 1261 } 1262 if r.PostForm == nil { 1263 r.PostForm = make(url.Values) 1264 } 1265 } 1266 if r.Form == nil { 1267 if len(r.PostForm) > 0 { 1268 r.Form = make(url.Values) 1269 copyValues(r.Form, r.PostForm) 1270 } 1271 var newValues url.Values 1272 if r.URL != nil { 1273 var e error 1274 newValues, e = url.ParseQuery(r.URL.RawQuery) 1275 if err == nil { 1276 err = e 1277 } 1278 } 1279 if newValues == nil { 1280 newValues = make(url.Values) 1281 } 1282 if r.Form == nil { 1283 r.Form = newValues 1284 } else { 1285 copyValues(r.Form, newValues) 1286 } 1287 } 1288 return err 1289 } 1290 1291 // ParseMultipartForm parses a request body as multipart/form-data. 1292 // The whole request body is parsed and up to a total of maxMemory bytes of 1293 // its file parts are stored in memory, with the remainder stored on 1294 // disk in temporary files. 1295 // ParseMultipartForm calls ParseForm if necessary. 1296 // If ParseForm returns an error, ParseMultipartForm returns it but also 1297 // continues parsing the request body. 1298 // After one call to ParseMultipartForm, subsequent calls have no effect. 1299 func (r *Request) ParseMultipartForm(maxMemory int64) error { 1300 if r.MultipartForm == multipartByReader { 1301 return errors.New("http: multipart handled by MultipartReader") 1302 } 1303 var parseFormErr error 1304 if r.Form == nil { 1305 // Let errors in ParseForm fall through, and just 1306 // return it at the end. 1307 parseFormErr = r.ParseForm() 1308 } 1309 if r.MultipartForm != nil { 1310 return nil 1311 } 1312 1313 mr, err := r.multipartReader(false) 1314 if err != nil { 1315 return err 1316 } 1317 1318 f, err := mr.ReadForm(maxMemory) 1319 if err != nil { 1320 return err 1321 } 1322 1323 if r.PostForm == nil { 1324 r.PostForm = make(url.Values) 1325 } 1326 for k, v := range f.Value { 1327 r.Form[k] = append(r.Form[k], v...) 1328 // r.PostForm should also be populated. See Issue 9305. 1329 r.PostForm[k] = append(r.PostForm[k], v...) 1330 } 1331 1332 r.MultipartForm = f 1333 1334 return parseFormErr 1335 } 1336 1337 // FormValue returns the first value for the named component of the query. 1338 // POST and PUT body parameters take precedence over URL query string values. 1339 // FormValue calls ParseMultipartForm and ParseForm if necessary and ignores 1340 // any errors returned by these functions. 1341 // If key is not present, FormValue returns the empty string. 1342 // To access multiple values of the same key, call ParseForm and 1343 // then inspect Request.Form directly. 1344 func (r *Request) FormValue(key string) string { 1345 if r.Form == nil { 1346 r.ParseMultipartForm(defaultMaxMemory) 1347 } 1348 if vs := r.Form[key]; len(vs) > 0 { 1349 return vs[0] 1350 } 1351 return "" 1352 } 1353 1354 // PostFormValue returns the first value for the named component of the POST, 1355 // PATCH, or PUT request body. URL query parameters are ignored. 1356 // PostFormValue calls ParseMultipartForm and ParseForm if necessary and ignores 1357 // any errors returned by these functions. 1358 // If key is not present, PostFormValue returns the empty string. 1359 func (r *Request) PostFormValue(key string) string { 1360 if r.PostForm == nil { 1361 r.ParseMultipartForm(defaultMaxMemory) 1362 } 1363 if vs := r.PostForm[key]; len(vs) > 0 { 1364 return vs[0] 1365 } 1366 return "" 1367 } 1368 1369 // FormFile returns the first file for the provided form key. 1370 // FormFile calls ParseMultipartForm and ParseForm if necessary. 1371 func (r *Request) FormFile(key string) (multipart.File, *multipart.FileHeader, error) { 1372 if r.MultipartForm == multipartByReader { 1373 return nil, nil, errors.New("http: multipart handled by MultipartReader") 1374 } 1375 if r.MultipartForm == nil { 1376 err := r.ParseMultipartForm(defaultMaxMemory) 1377 if err != nil { 1378 return nil, nil, err 1379 } 1380 } 1381 if r.MultipartForm != nil && r.MultipartForm.File != nil { 1382 if fhs := r.MultipartForm.File[key]; len(fhs) > 0 { 1383 f, err := fhs[0].Open() 1384 return f, fhs[0], err 1385 } 1386 } 1387 return nil, nil, ErrMissingFile 1388 } 1389 1390 func (r *Request) expectsContinue() bool { 1391 return hasToken(r.Header.get("Expect"), "100-continue") 1392 } 1393 1394 func (r *Request) wantsHttp10KeepAlive() bool { 1395 if r.ProtoMajor != 1 || r.ProtoMinor != 0 { 1396 return false 1397 } 1398 return hasToken(r.Header.get("Connection"), "keep-alive") 1399 } 1400 1401 func (r *Request) wantsClose() bool { 1402 if r.Close { 1403 return true 1404 } 1405 return hasToken(r.Header.get("Connection"), "close") 1406 } 1407 1408 func (r *Request) closeBody() error { 1409 if r.Body == nil { 1410 return nil 1411 } 1412 return r.Body.Close() 1413 } 1414 1415 func (r *Request) isReplayable() bool { 1416 if r.Body == nil || r.Body == NoBody || r.GetBody != nil { 1417 switch valueOrDefault(r.Method, "GET") { 1418 case "GET", "HEAD", "OPTIONS", "TRACE": 1419 return true 1420 } 1421 // The Idempotency-Key, while non-standard, is widely used to 1422 // mean a POST or other request is idempotent. See 1423 // https://golang.org/issue/19943#issuecomment-421092421 1424 if r.Header.has("Idempotency-Key") || r.Header.has("X-Idempotency-Key") { 1425 return true 1426 } 1427 } 1428 return false 1429 } 1430 1431 // outgoingLength reports the Content-Length of this outgoing (Client) request. 1432 // It maps 0 into -1 (unknown) when the Body is non-nil. 1433 func (r *Request) outgoingLength() int64 { 1434 if r.Body == nil || r.Body == NoBody { 1435 return 0 1436 } 1437 if r.ContentLength != 0 { 1438 return r.ContentLength 1439 } 1440 return -1 1441 } 1442 1443 // requestMethodUsuallyLacksBody reports whether the given request 1444 // method is one that typically does not involve a request body. 1445 // This is used by the Transport (via 1446 // transferWriter.shouldSendChunkedRequestBody) to determine whether 1447 // we try to test-read a byte from a non-nil Request.Body when 1448 // Request.outgoingLength() returns -1. See the comments in 1449 // shouldSendChunkedRequestBody. 1450 func requestMethodUsuallyLacksBody(method string) bool { 1451 switch method { 1452 case "GET", "HEAD", "DELETE", "OPTIONS", "PROPFIND", "SEARCH": 1453 return true 1454 } 1455 return false 1456 } 1457 1458 // requiresHTTP1 reports whether this request requires being sent on 1459 // an HTTP/1 connection. 1460 func (r *Request) requiresHTTP1() bool { 1461 return hasToken(r.Header.Get("Connection"), "upgrade") && 1462 ascii.EqualFold(r.Header.Get("Upgrade"), "websocket") 1463 } 1464