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.
5 // HTTP client. See RFC 7230 through 7235.
7 // This is the high-level Client interface.
8 // The low-level implementation is in transport.go.
20 "net/http/internal/ascii"
29 // A Client is an HTTP client. Its zero value (DefaultClient) is a
30 // usable client that uses DefaultTransport.
32 // The Client's Transport typically has internal state (cached TCP
33 // connections), so Clients should be reused instead of created as
34 // needed. Clients are safe for concurrent use by multiple goroutines.
36 // A Client is higher-level than a RoundTripper (such as Transport)
37 // and additionally handles HTTP details such as cookies and
40 // When following redirects, the Client will forward all headers set on the
41 // initial Request except:
43 // • when forwarding sensitive headers like "Authorization",
44 // "WWW-Authenticate", and "Cookie" to untrusted targets.
45 // These headers will be ignored when following a redirect to a domain
46 // that is not a subdomain match or exact match of the initial domain.
47 // For example, a redirect from "foo.com" to either "foo.com" or "sub.foo.com"
48 // will forward the sensitive headers, but a redirect to "bar.com" will not.
50 // • when forwarding the "Cookie" header with a non-nil cookie Jar.
51 // Since each redirect may mutate the state of the cookie jar,
52 // a redirect may possibly alter a cookie set in the initial request.
53 // When forwarding the "Cookie" header, any mutated cookies will be omitted,
54 // with the expectation that the Jar will insert those mutated cookies
55 // with the updated values (assuming the origin matches).
56 // If Jar is nil, the initial cookies are forwarded without change.
59 // Transport specifies the mechanism by which individual
60 // HTTP requests are made.
61 // If nil, DefaultTransport is used.
62 Transport RoundTripper
64 // CheckRedirect specifies the policy for handling redirects.
65 // If CheckRedirect is not nil, the client calls it before
66 // following an HTTP redirect. The arguments req and via are
67 // the upcoming request and the requests made already, oldest
68 // first. If CheckRedirect returns an error, the Client's Get
69 // method returns both the previous Response (with its Body
70 // closed) and CheckRedirect's error (wrapped in a url.Error)
71 // instead of issuing the Request req.
72 // As a special case, if CheckRedirect returns ErrUseLastResponse,
73 // then the most recent response is returned with its body
74 // unclosed, along with a nil error.
76 // If CheckRedirect is nil, the Client uses its default policy,
77 // which is to stop after 10 consecutive requests.
78 CheckRedirect
func(req
*Request
, via
[]*Request
) error
80 // Jar specifies the cookie jar.
82 // The Jar is used to insert relevant cookies into every
83 // outbound Request and is updated with the cookie values
84 // of every inbound Response. The Jar is consulted for every
85 // redirect that the Client follows.
87 // If Jar is nil, cookies are only sent if they are explicitly
88 // set on the Request.
91 // Timeout specifies a time limit for requests made by this
92 // Client. The timeout includes connection time, any
93 // redirects, and reading the response body. The timer remains
94 // running after Get, Head, Post, or Do return and will
95 // interrupt reading of the Response.Body.
97 // A Timeout of zero means no timeout.
99 // The Client cancels requests to the underlying Transport
100 // as if the Request's Context ended.
102 // For compatibility, the Client will also use the deprecated
103 // CancelRequest method on Transport if found. New
104 // RoundTripper implementations should use the Request's Context
105 // for cancellation instead of implementing CancelRequest.
106 Timeout time
.Duration
109 // DefaultClient is the default Client and is used by Get, Head, and Post.
110 var DefaultClient
= &Client
{}
112 // RoundTripper is an interface representing the ability to execute a
113 // single HTTP transaction, obtaining the Response for a given Request.
115 // A RoundTripper must be safe for concurrent use by multiple
117 type RoundTripper
interface {
118 // RoundTrip executes a single HTTP transaction, returning
119 // a Response for the provided Request.
121 // RoundTrip should not attempt to interpret the response. In
122 // particular, RoundTrip must return err == nil if it obtained
123 // a response, regardless of the response's HTTP status code.
124 // A non-nil err should be reserved for failure to obtain a
125 // response. Similarly, RoundTrip should not attempt to
126 // handle higher-level protocol details such as redirects,
127 // authentication, or cookies.
129 // RoundTrip should not modify the request, except for
130 // consuming and closing the Request's Body. RoundTrip may
131 // read fields of the request in a separate goroutine. Callers
132 // should not mutate or reuse the request until the Response's
133 // Body has been closed.
135 // RoundTrip must always close the body, including on errors,
136 // but depending on the implementation may do so in a separate
137 // goroutine even after RoundTrip returns. This means that
138 // callers wanting to reuse the body for subsequent requests
139 // must arrange to wait for the Close call before doing so.
141 // The Request's URL and Header fields must be initialized.
142 RoundTrip(*Request
) (*Response
, error
)
145 // refererForURL returns a referer without any authentication info or
146 // an empty string if lastReq scheme is https and newReq scheme is http.
147 func refererForURL(lastReq
, newReq
*url
.URL
) string {
148 // https://tools.ietf.org/html/rfc7231#section-5.5.2
149 // "Clients SHOULD NOT include a Referer header field in a
150 // (non-secure) HTTP request if the referring page was
151 // transferred with a secure protocol."
152 if lastReq
.Scheme
== "https" && newReq
.Scheme
== "http" {
155 referer
:= lastReq
.String()
156 if lastReq
.User
!= nil {
157 // This is not very efficient, but is the best we can
159 // - introducing a new method on URL
160 // - creating a race condition
161 // - copying the URL struct manually, which would cause
162 // maintenance problems down the line
163 auth
:= lastReq
.User
.String() + "@"
164 referer
= strings
.Replace(referer
, auth
, "", 1)
169 // didTimeout is non-nil only if err != nil.
170 func (c
*Client
) send(req
*Request
, deadline time
.Time
) (resp
*Response
, didTimeout
func() bool, err error
) {
172 for _
, cookie
:= range c
.Jar
.Cookies(req
.URL
) {
173 req
.AddCookie(cookie
)
176 resp
, didTimeout
, err
= send(req
, c
.transport(), deadline
)
178 return nil, didTimeout
, err
181 if rc
:= resp
.Cookies(); len(rc
) > 0 {
182 c
.Jar
.SetCookies(req
.URL
, rc
)
185 return resp
, nil, nil
188 func (c
*Client
) deadline() time
.Time
{
190 return time
.Now().Add(c
.Timeout
)
195 func (c
*Client
) transport() RoundTripper
{
196 if c
.Transport
!= nil {
199 return DefaultTransport
202 // send issues an HTTP request.
203 // Caller should close resp.Body when done reading from it.
204 func send(ireq
*Request
, rt RoundTripper
, deadline time
.Time
) (resp
*Response
, didTimeout
func() bool, err error
) {
205 req
:= ireq
// req is either the original request, or a modified fork
209 return nil, alwaysFalse
, errors
.New("http: no Client.Transport or DefaultTransport")
214 return nil, alwaysFalse
, errors
.New("http: nil Request.URL")
217 if req
.RequestURI
!= "" {
219 return nil, alwaysFalse
, errors
.New("http: Request.RequestURI can't be set in client requests")
222 // forkReq forks req into a shallow clone of ireq the first
227 *req
= *ireq
// shallow clone
231 // Most the callers of send (Get, Post, et al) don't need
232 // Headers, leaving it uninitialized. We guarantee to the
233 // Transport that this has been initialized, though.
234 if req
.Header
== nil {
236 req
.Header
= make(Header
)
239 if u
:= req
.URL
.User
; u
!= nil && req
.Header
.Get("Authorization") == "" {
240 username
:= u
.Username()
241 password
, _
:= u
.Password()
243 req
.Header
= cloneOrMakeHeader(ireq
.Header
)
244 req
.Header
.Set("Authorization", "Basic "+basicAuth(username
, password
))
247 if !deadline
.IsZero() {
250 stopTimer
, didTimeout
:= setRequestCancel(req
, rt
, deadline
)
252 resp
, err
= rt
.RoundTrip(req
)
256 log
.Printf("RoundTripper returned a response & error; ignoring response")
258 if tlsErr
, ok
:= err
.(tls
.RecordHeaderError
); ok
{
259 // If we get a bad TLS record header, check to see if the
260 // response looks like HTTP and give a more helpful error.
261 // See golang.org/issue/11111.
262 if string(tlsErr
.RecordHeader
[:]) == "HTTP/" {
263 err
= errors
.New("http: server gave HTTP response to HTTPS client")
266 return nil, didTimeout
, err
269 return nil, didTimeout
, fmt
.Errorf("http: RoundTripper implementation (%T) returned a nil *Response with a nil error", rt
)
271 if resp
.Body
== nil {
272 // The documentation on the Body field says “The http Client and Transport
273 // guarantee that Body is always non-nil, even on responses without a body
274 // or responses with a zero-length body.” Unfortunately, we didn't document
275 // that same constraint for arbitrary RoundTripper implementations, and
276 // RoundTripper implementations in the wild (mostly in tests) assume that
277 // they can use a nil Body to mean an empty one (similar to Request.Body).
278 // (See https://golang.org/issue/38095.)
280 // If the ContentLength allows the Body to be empty, fill in an empty one
281 // here to ensure that it is non-nil.
282 if resp
.ContentLength
> 0 && req
.Method
!= "HEAD" {
283 return nil, didTimeout
, fmt
.Errorf("http: RoundTripper implementation (%T) returned a *Response with content length %d but a nil Body", rt
, resp
.ContentLength
)
285 resp
.Body
= io
.NopCloser(strings
.NewReader(""))
287 if !deadline
.IsZero() {
288 resp
.Body
= &cancelTimerBody
{
291 reqDidTimeout
: didTimeout
,
294 return resp
, nil, nil
297 // timeBeforeContextDeadline reports whether the non-zero Time t is
298 // before ctx's deadline, if any. If ctx does not have a deadline, it
299 // always reports true (the deadline is considered infinite).
300 func timeBeforeContextDeadline(t time
.Time
, ctx context
.Context
) bool {
301 d
, ok
:= ctx
.Deadline()
308 // knownRoundTripperImpl reports whether rt is a RoundTripper that's
309 // maintained by the Go team and known to implement the latest
310 // optional semantics (notably contexts). The Request is used
311 // to check whether this particular request is using an alternate protocol,
312 // in which case we need to check the RoundTripper for that protocol.
313 func knownRoundTripperImpl(rt RoundTripper
, req
*Request
) bool {
314 switch t
:= rt
.(type) {
316 if altRT
:= t
.alternateRoundTripper(req
); altRT
!= nil {
317 return knownRoundTripperImpl(altRT
, req
)
320 case *http2Transport
, http2noDialH2RoundTripper
:
323 // There's a very minor chance of a false positive with this.
324 // Instead of detecting our golang.org/x/net/http2.Transport,
325 // it might detect a Transport type in a different http2
326 // package. But I know of none, and the only problem would be
327 // some temporarily leaked goroutines if the transport didn't
328 // support contexts. So this is a good enough heuristic:
329 if reflect
.TypeOf(rt
).String() == "*http2.Transport" {
335 // setRequestCancel sets req.Cancel and adds a deadline context to req
336 // if deadline is non-zero. The RoundTripper's type is used to
337 // determine whether the legacy CancelRequest behavior should be used.
339 // As background, there are three ways to cancel a request:
340 // First was Transport.CancelRequest. (deprecated)
341 // Second was Request.Cancel.
342 // Third was Request.Context.
343 // This function populates the second and third, and uses the first if it really needs to.
344 func setRequestCancel(req
*Request
, rt RoundTripper
, deadline time
.Time
) (stopTimer
func(), didTimeout
func() bool) {
345 if deadline
.IsZero() {
346 return nop
, alwaysFalse
348 knownTransport
:= knownRoundTripperImpl(rt
, req
)
349 oldCtx
:= req
.Context()
351 if req
.Cancel
== nil && knownTransport
{
352 // If they already had a Request.Context that's
353 // expiring sooner, do nothing:
354 if !timeBeforeContextDeadline(deadline
, oldCtx
) {
355 return nop
, alwaysFalse
359 req
.ctx
, cancelCtx
= context
.WithDeadline(oldCtx
, deadline
)
360 return cancelCtx
, func() bool { return time
.Now().After(deadline
) }
362 initialReqCancel
:= req
.Cancel
// the user's original Request.Cancel, if any
365 if oldCtx
:= req
.Context(); timeBeforeContextDeadline(deadline
, oldCtx
) {
366 req
.ctx
, cancelCtx
= context
.WithDeadline(oldCtx
, deadline
)
369 cancel
:= make(chan struct{})
373 // The second way in the func comment above:
375 // The first way, used only for RoundTripper
376 // implementations written before Go 1.5 or Go 1.6.
377 type canceler
interface{ CancelRequest(*Request
) }
378 if v
, ok
:= rt
.(canceler
); ok
{
383 stopTimerCh
:= make(chan struct{})
388 if cancelCtx
!= nil {
394 timer
:= time
.NewTimer(time
.Until(deadline
))
395 var timedOut atomicBool
399 case <-initialReqCancel
:
410 return stopTimer
, timedOut
.isSet
413 // See 2 (end of page 4) https://www.ietf.org/rfc/rfc2617.txt
414 // "To receive authorization, the client sends the userid and password,
415 // separated by a single colon (":") character, within a base64
416 // encoded string in the credentials."
417 // It is not meant to be urlencoded.
418 func basicAuth(username
, password
string) string {
419 auth
:= username
+ ":" + password
420 return base64
.StdEncoding
.EncodeToString([]byte(auth
))
423 // Get issues a GET to the specified URL. If the response is one of
424 // the following redirect codes, Get follows the redirect, up to a
425 // maximum of 10 redirects:
427 // 301 (Moved Permanently)
430 // 307 (Temporary Redirect)
431 // 308 (Permanent Redirect)
433 // An error is returned if there were too many redirects or if there
434 // was an HTTP protocol error. A non-2xx response doesn't cause an
435 // error. Any returned error will be of type *url.Error. The url.Error
436 // value's Timeout method will report true if the request timed out.
438 // When err is nil, resp always contains a non-nil resp.Body.
439 // Caller should close resp.Body when done reading from it.
441 // Get is a wrapper around DefaultClient.Get.
443 // To make a request with custom headers, use NewRequest and
446 // To make a request with a specified context.Context, use NewRequestWithContext
447 // and DefaultClient.Do.
448 func Get(url
string) (resp
*Response
, err error
) {
449 return DefaultClient
.Get(url
)
452 // Get issues a GET to the specified URL. If the response is one of the
453 // following redirect codes, Get follows the redirect after calling the
454 // Client's CheckRedirect function:
456 // 301 (Moved Permanently)
459 // 307 (Temporary Redirect)
460 // 308 (Permanent Redirect)
462 // An error is returned if the Client's CheckRedirect function fails
463 // or if there was an HTTP protocol error. A non-2xx response doesn't
464 // cause an error. Any returned error will be of type *url.Error. The
465 // url.Error value's Timeout method will report true if the request
468 // When err is nil, resp always contains a non-nil resp.Body.
469 // Caller should close resp.Body when done reading from it.
471 // To make a request with custom headers, use NewRequest and Client.Do.
473 // To make a request with a specified context.Context, use NewRequestWithContext
475 func (c
*Client
) Get(url
string) (resp
*Response
, err error
) {
476 req
, err
:= NewRequest("GET", url
, nil)
483 func alwaysFalse() bool { return false }
485 // ErrUseLastResponse can be returned by Client.CheckRedirect hooks to
486 // control how redirects are processed. If returned, the next request
487 // is not sent and the most recent response is returned with its body
489 var ErrUseLastResponse
= errors
.New("net/http: use last response")
491 // checkRedirect calls either the user's configured CheckRedirect
492 // function, or the default.
493 func (c
*Client
) checkRedirect(req
*Request
, via
[]*Request
) error
{
494 fn
:= c
.CheckRedirect
496 fn
= defaultCheckRedirect
501 // redirectBehavior describes what should happen when the
502 // client encounters a 3xx status code from the server
503 func redirectBehavior(reqMethod
string, resp
*Response
, ireq
*Request
) (redirectMethod
string, shouldRedirect
, includeBody
bool) {
504 switch resp
.StatusCode
{
506 redirectMethod
= reqMethod
507 shouldRedirect
= true
510 // RFC 2616 allowed automatic redirection only with GET and
511 // HEAD requests. RFC 7231 lifts this restriction, but we still
512 // restrict other methods to GET to maintain compatibility.
514 if reqMethod
!= "GET" && reqMethod
!= "HEAD" {
515 redirectMethod
= "GET"
518 redirectMethod
= reqMethod
519 shouldRedirect
= true
522 // Treat 307 and 308 specially, since they're new in
523 // Go 1.8, and they also require re-sending the request body.
524 if resp
.Header
.Get("Location") == "" {
525 // 308s have been observed in the wild being served
526 // without Location headers. Since Go 1.7 and earlier
527 // didn't follow these codes, just stop here instead
528 // of returning an error.
530 shouldRedirect
= false
533 if ireq
.GetBody
== nil && ireq
.outgoingLength() != 0 {
534 // We had a request body, and 307/308 require
535 // re-sending it, but GetBody is not defined. So just
536 // return this response to the user instead of an
537 // error, like we did in Go 1.7 and earlier.
538 shouldRedirect
= false
541 return redirectMethod
, shouldRedirect
, includeBody
544 // urlErrorOp returns the (*url.Error).Op value to use for the
545 // provided (*Request).Method value.
546 func urlErrorOp(method
string) string {
550 if lowerMethod
, ok
:= ascii
.ToLower(method
); ok
{
551 return method
[:1] + lowerMethod
[1:]
556 // Do sends an HTTP request and returns an HTTP response, following
557 // policy (such as redirects, cookies, auth) as configured on the
560 // An error is returned if caused by client policy (such as
561 // CheckRedirect), or failure to speak HTTP (such as a network
562 // connectivity problem). A non-2xx status code doesn't cause an
565 // If the returned error is nil, the Response will contain a non-nil
566 // Body which the user is expected to close. If the Body is not both
567 // read to EOF and closed, the Client's underlying RoundTripper
568 // (typically Transport) may not be able to re-use a persistent TCP
569 // connection to the server for a subsequent "keep-alive" request.
571 // The request Body, if non-nil, will be closed by the underlying
572 // Transport, even on errors.
574 // On error, any Response can be ignored. A non-nil Response with a
575 // non-nil error only occurs when CheckRedirect fails, and even then
576 // the returned Response.Body is already closed.
578 // Generally Get, Post, or PostForm will be used instead of Do.
580 // If the server replies with a redirect, the Client first uses the
581 // CheckRedirect function to determine whether the redirect should be
582 // followed. If permitted, a 301, 302, or 303 redirect causes
583 // subsequent requests to use HTTP method GET
584 // (or HEAD if the original request was HEAD), with no body.
585 // A 307 or 308 redirect preserves the original HTTP method and body,
586 // provided that the Request.GetBody function is defined.
587 // The NewRequest function automatically sets GetBody for common
588 // standard library body types.
590 // Any returned error will be of type *url.Error. The url.Error
591 // value's Timeout method will report true if the request timed out.
592 func (c
*Client
) Do(req
*Request
) (*Response
, error
) {
596 var testHookClientDoResult
func(retres
*Response
, reterr error
)
598 func (c
*Client
) do(req
*Request
) (retres
*Response
, reterr error
) {
599 if testHookClientDoResult
!= nil {
600 defer func() { testHookClientDoResult(retres
, reterr
) }()
604 return nil, &url
.Error
{
605 Op
: urlErrorOp(req
.Method
),
606 Err
: errors
.New("http: nil Request.URL"),
611 deadline
= c
.deadline()
614 copyHeaders
= c
.makeHeadersCopier(req
)
615 reqBodyClosed
= false // have we closed the current req.Body?
617 // Redirect behavior:
618 redirectMethod
string
621 uerr
:= func(err error
) error
{
622 // the body may have been closed already by c.send()
627 if resp
!= nil && resp
.Request
!= nil {
628 urlStr
= stripPassword(resp
.Request
.URL
)
630 urlStr
= stripPassword(req
.URL
)
633 Op
: urlErrorOp(reqs
[0].Method
),
639 // For all but the first request, create the next
640 // request hop and replace req.
642 loc
:= resp
.Header
.Get("Location")
645 return nil, uerr(fmt
.Errorf("%d response missing Location header", resp
.StatusCode
))
647 u
, err
:= req
.URL
.Parse(loc
)
650 return nil, uerr(fmt
.Errorf("failed to parse Location header %q: %v", loc
, err
))
653 if req
.Host
!= "" && req
.Host
!= req
.URL
.Host
{
654 // If the caller specified a custom Host header and the
655 // redirect location is relative, preserve the Host header
656 // through the redirect. See issue #22233.
657 if u
, _
:= url
.Parse(loc
); u
!= nil && !u
.IsAbs() {
663 Method
: redirectMethod
,
666 Header
: make(Header
),
671 if includeBody
&& ireq
.GetBody
!= nil {
672 req
.Body
, err
= ireq
.GetBody()
675 return nil, uerr(err
)
677 req
.ContentLength
= ireq
.ContentLength
680 // Copy original headers before setting the Referer,
681 // in case the user set Referer on their first request.
682 // If they really want to override, they can do it in
683 // their CheckRedirect func.
686 // Add the Referer header from the most recent
687 // request URL to the new one, if it's not https->http:
688 if ref
:= refererForURL(reqs
[len(reqs
)-1].URL
, req
.URL
); ref
!= "" {
689 req
.Header
.Set("Referer", ref
)
691 err
= c
.checkRedirect(req
, reqs
)
693 // Sentinel error to let users select the
694 // previous response, without closing its
695 // body. See Issue 10069.
696 if err
== ErrUseLastResponse
{
700 // Close the previous response's body. But
701 // read at least some of the body so if it's
702 // small the underlying TCP connection will be
703 // re-used. No need to check for errors: if it
704 // fails, the Transport won't reuse it anyway.
705 const maxBodySlurpSize
= 2 << 10
706 if resp
.ContentLength
== -1 || resp
.ContentLength
<= maxBodySlurpSize
{
707 io
.CopyN(io
.Discard
, resp
.Body
, maxBodySlurpSize
)
712 // Special case for Go 1 compatibility: return both the response
713 // and an error if the CheckRedirect function failed.
714 // See https://golang.org/issue/3795
715 // The resp.Body has already been closed.
717 ue
.(*url
.Error
).URL
= loc
722 reqs
= append(reqs
, req
)
724 var didTimeout
func() bool
725 if resp
, didTimeout
, err
= c
.send(req
, deadline
); err
!= nil {
726 // c.send() always closes req.Body
728 if !deadline
.IsZero() && didTimeout() {
730 err
: err
.Error() + " (Client.Timeout exceeded while awaiting headers)",
734 return nil, uerr(err
)
737 var shouldRedirect
bool
738 redirectMethod
, shouldRedirect
, includeBody
= redirectBehavior(req
.Method
, resp
, reqs
[0])
747 // makeHeadersCopier makes a function that copies headers from the
748 // initial Request, ireq. For every redirect, this function must be called
749 // so that it can copy headers into the upcoming Request.
750 func (c
*Client
) makeHeadersCopier(ireq
*Request
) func(*Request
) {
751 // The headers to copy are from the very initial request.
752 // We use a closured callback to keep a reference to these original headers.
754 ireqhdr
= cloneOrMakeHeader(ireq
.Header
)
755 icookies
map[string][]*Cookie
757 if c
.Jar
!= nil && ireq
.Header
.Get("Cookie") != "" {
758 icookies
= make(map[string][]*Cookie
)
759 for _
, c
:= range ireq
.Cookies() {
760 icookies
[c
.Name
] = append(icookies
[c
.Name
], c
)
764 preq
:= ireq
// The previous request
765 return func(req
*Request
) {
766 // If Jar is present and there was some initial cookies provided
767 // via the request header, then we may need to alter the initial
768 // cookies as we follow redirects since each redirect may end up
769 // modifying a pre-existing cookie.
771 // Since cookies already set in the request header do not contain
772 // information about the original domain and path, the logic below
773 // assumes any new set cookies override the original cookie
774 // regardless of domain or path.
776 // See https://golang.org/issue/17494
777 if c
.Jar
!= nil && icookies
!= nil {
779 resp
:= req
.Response
// The response that caused the upcoming redirect
780 for _
, c
:= range resp
.Cookies() {
781 if _
, ok
:= icookies
[c
.Name
]; ok
{
782 delete(icookies
, c
.Name
)
787 ireqhdr
.Del("Cookie")
789 for _
, cs
:= range icookies
{
790 for _
, c
:= range cs
{
791 ss
= append(ss
, c
.Name
+"="+c
.Value
)
794 sort
.Strings(ss
) // Ensure deterministic headers
795 ireqhdr
.Set("Cookie", strings
.Join(ss
, "; "))
799 // Copy the initial request's Header values
800 // (at least the safe ones).
801 for k
, vv
:= range ireqhdr
{
802 if shouldCopyHeaderOnRedirect(k
, preq
.URL
, req
.URL
) {
807 preq
= req
// Update previous Request with the current request
811 func defaultCheckRedirect(req
*Request
, via
[]*Request
) error
{
813 return errors
.New("stopped after 10 redirects")
818 // Post issues a POST to the specified URL.
820 // Caller should close resp.Body when done reading from it.
822 // If the provided body is an io.Closer, it is closed after the
825 // Post is a wrapper around DefaultClient.Post.
827 // To set custom headers, use NewRequest and DefaultClient.Do.
829 // See the Client.Do method documentation for details on how redirects
832 // To make a request with a specified context.Context, use NewRequestWithContext
833 // and DefaultClient.Do.
834 func Post(url
, contentType
string, body io
.Reader
) (resp
*Response
, err error
) {
835 return DefaultClient
.Post(url
, contentType
, body
)
838 // Post issues a POST to the specified URL.
840 // Caller should close resp.Body when done reading from it.
842 // If the provided body is an io.Closer, it is closed after the
845 // To set custom headers, use NewRequest and Client.Do.
847 // To make a request with a specified context.Context, use NewRequestWithContext
850 // See the Client.Do method documentation for details on how redirects
852 func (c
*Client
) Post(url
, contentType
string, body io
.Reader
) (resp
*Response
, err error
) {
853 req
, err
:= NewRequest("POST", url
, body
)
857 req
.Header
.Set("Content-Type", contentType
)
861 // PostForm issues a POST to the specified URL, with data's keys and
862 // values URL-encoded as the request body.
864 // The Content-Type header is set to application/x-www-form-urlencoded.
865 // To set other headers, use NewRequest and DefaultClient.Do.
867 // When err is nil, resp always contains a non-nil resp.Body.
868 // Caller should close resp.Body when done reading from it.
870 // PostForm is a wrapper around DefaultClient.PostForm.
872 // See the Client.Do method documentation for details on how redirects
875 // To make a request with a specified context.Context, use NewRequestWithContext
876 // and DefaultClient.Do.
877 func PostForm(url
string, data url
.Values
) (resp
*Response
, err error
) {
878 return DefaultClient
.PostForm(url
, data
)
881 // PostForm issues a POST to the specified URL,
882 // with data's keys and values URL-encoded as the request body.
884 // The Content-Type header is set to application/x-www-form-urlencoded.
885 // To set other headers, use NewRequest and Client.Do.
887 // When err is nil, resp always contains a non-nil resp.Body.
888 // Caller should close resp.Body when done reading from it.
890 // See the Client.Do method documentation for details on how redirects
893 // To make a request with a specified context.Context, use NewRequestWithContext
895 func (c
*Client
) PostForm(url
string, data url
.Values
) (resp
*Response
, err error
) {
896 return c
.Post(url
, "application/x-www-form-urlencoded", strings
.NewReader(data
.Encode()))
899 // Head issues a HEAD to the specified URL. If the response is one of
900 // the following redirect codes, Head follows the redirect, up to a
901 // maximum of 10 redirects:
903 // 301 (Moved Permanently)
906 // 307 (Temporary Redirect)
907 // 308 (Permanent Redirect)
909 // Head is a wrapper around DefaultClient.Head
911 // To make a request with a specified context.Context, use NewRequestWithContext
912 // and DefaultClient.Do.
913 func Head(url
string) (resp
*Response
, err error
) {
914 return DefaultClient
.Head(url
)
917 // Head issues a HEAD to the specified URL. If the response is one of the
918 // following redirect codes, Head follows the redirect after calling the
919 // Client's CheckRedirect function:
921 // 301 (Moved Permanently)
924 // 307 (Temporary Redirect)
925 // 308 (Permanent Redirect)
927 // To make a request with a specified context.Context, use NewRequestWithContext
929 func (c
*Client
) Head(url
string) (resp
*Response
, err error
) {
930 req
, err
:= NewRequest("HEAD", url
, nil)
937 // CloseIdleConnections closes any connections on its Transport which
938 // were previously connected from previous requests but are now
939 // sitting idle in a "keep-alive" state. It does not interrupt any
940 // connections currently in use.
942 // If the Client's Transport does not have a CloseIdleConnections method
943 // then this method does nothing.
944 func (c
*Client
) CloseIdleConnections() {
945 type closeIdler
interface {
946 CloseIdleConnections()
948 if tr
, ok
:= c
.transport().(closeIdler
); ok
{
949 tr
.CloseIdleConnections()
953 // cancelTimerBody is an io.ReadCloser that wraps rc with two features:
954 // 1) On Read error or close, the stop func is called.
955 // 2) On Read failure, if reqDidTimeout is true, the error is wrapped and
956 // marked as net.Error that hit its timeout.
957 type cancelTimerBody
struct {
958 stop
func() // stops the time.Timer waiting to cancel the request
960 reqDidTimeout
func() bool
963 func (b
*cancelTimerBody
) Read(p
[]byte) (n
int, err error
) {
964 n
, err
= b
.rc
.Read(p
)
971 if b
.reqDidTimeout() {
973 err
: err
.Error() + " (Client.Timeout or context cancellation while reading body)",
980 func (b
*cancelTimerBody
) Close() error
{
986 func shouldCopyHeaderOnRedirect(headerKey
string, initial
, dest
*url
.URL
) bool {
987 switch CanonicalHeaderKey(headerKey
) {
988 case "Authorization", "Www-Authenticate", "Cookie", "Cookie2":
989 // Permit sending auth/cookie headers from "foo.com"
992 // Note that we don't send all cookies to subdomains
993 // automatically. This function is only used for
994 // Cookies set explicitly on the initial outgoing
995 // client request. Cookies automatically added via the
996 // CookieJar mechanism continue to follow each
997 // cookie's scope as set by Set-Cookie. But for
998 // outgoing requests with the Cookie header set
999 // directly, we don't know their scope, so we assume
1000 // it's for *.domain.com.
1002 ihost
:= canonicalAddr(initial
)
1003 dhost
:= canonicalAddr(dest
)
1004 return isDomainOrSubdomain(dhost
, ihost
)
1006 // All other headers are copied:
1010 // isDomainOrSubdomain reports whether sub is a subdomain (or exact
1011 // match) of the parent domain.
1013 // Both domains must already be in canonical form.
1014 func isDomainOrSubdomain(sub
, parent
string) bool {
1018 // If sub is "foo.example.com" and parent is "example.com",
1019 // that means sub must end in "."+parent.
1020 // Do it without allocating.
1021 if !strings
.HasSuffix(sub
, parent
) {
1024 return sub
[len(sub
)-len(parent
)-1] == '.'
1027 func stripPassword(u
*url
.URL
) string {
1028 _
, passSet
:= u
.User
.Password()
1030 return strings
.Replace(u
.String(), u
.User
.String()+"@", u
.User
.Username()+":***@", 1)