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Diffstat (limited to 'src/net/http/client.go')
| -rw-r--r-- | src/net/http/client.go | 1009 |
1 files changed, 1009 insertions, 0 deletions
diff --git a/src/net/http/client.go b/src/net/http/client.go new file mode 100644 index 0000000..88e2028 --- /dev/null +++ b/src/net/http/client.go @@ -0,0 +1,1009 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// HTTP client. See RFC 7230 through 7235. +// +// This is the high-level Client interface. +// The low-level implementation is in transport.go. + +package http + +import ( + "context" + "crypto/tls" + "encoding/base64" + "errors" + "fmt" + "io" + "log" + "net/url" + "reflect" + "sort" + "strings" + "sync" + "time" +) + +// A Client is an HTTP client. Its zero value (DefaultClient) is a +// usable client that uses DefaultTransport. +// +// The Client's Transport typically has internal state (cached TCP +// connections), so Clients should be reused instead of created as +// needed. Clients are safe for concurrent use by multiple goroutines. +// +// A Client is higher-level than a RoundTripper (such as Transport) +// and additionally handles HTTP details such as cookies and +// redirects. +// +// When following redirects, the Client will forward all headers set on the +// initial Request except: +// +// • when forwarding sensitive headers like "Authorization", +// "WWW-Authenticate", and "Cookie" to untrusted targets. +// These headers will be ignored when following a redirect to a domain +// that is not a subdomain match or exact match of the initial domain. +// For example, a redirect from "foo.com" to either "foo.com" or "sub.foo.com" +// will forward the sensitive headers, but a redirect to "bar.com" will not. +// +// • when forwarding the "Cookie" header with a non-nil cookie Jar. +// Since each redirect may mutate the state of the cookie jar, +// a redirect may possibly alter a cookie set in the initial request. +// When forwarding the "Cookie" header, any mutated cookies will be omitted, +// with the expectation that the Jar will insert those mutated cookies +// with the updated values (assuming the origin matches). +// If Jar is nil, the initial cookies are forwarded without change. +// +type Client struct { + // Transport specifies the mechanism by which individual + // HTTP requests are made. + // If nil, DefaultTransport is used. + Transport RoundTripper + + // CheckRedirect specifies the policy for handling redirects. + // If CheckRedirect is not nil, the client calls it before + // following an HTTP redirect. The arguments req and via are + // the upcoming request and the requests made already, oldest + // first. If CheckRedirect returns an error, the Client's Get + // method returns both the previous Response (with its Body + // closed) and CheckRedirect's error (wrapped in a url.Error) + // instead of issuing the Request req. + // As a special case, if CheckRedirect returns ErrUseLastResponse, + // then the most recent response is returned with its body + // unclosed, along with a nil error. + // + // If CheckRedirect is nil, the Client uses its default policy, + // which is to stop after 10 consecutive requests. + CheckRedirect func(req *Request, via []*Request) error + + // Jar specifies the cookie jar. + // + // The Jar is used to insert relevant cookies into every + // outbound Request and is updated with the cookie values + // of every inbound Response. The Jar is consulted for every + // redirect that the Client follows. + // + // If Jar is nil, cookies are only sent if they are explicitly + // set on the Request. + Jar CookieJar + + // Timeout specifies a time limit for requests made by this + // Client. The timeout includes connection time, any + // redirects, and reading the response body. The timer remains + // running after Get, Head, Post, or Do return and will + // interrupt reading of the Response.Body. + // + // A Timeout of zero means no timeout. + // + // The Client cancels requests to the underlying Transport + // as if the Request's Context ended. + // + // For compatibility, the Client will also use the deprecated + // CancelRequest method on Transport if found. New + // RoundTripper implementations should use the Request's Context + // for cancellation instead of implementing CancelRequest. + Timeout time.Duration +} + +// DefaultClient is the default Client and is used by Get, Head, and Post. +var DefaultClient = &Client{} + +// RoundTripper is an interface representing the ability to execute a +// single HTTP transaction, obtaining the Response for a given Request. +// +// A RoundTripper must be safe for concurrent use by multiple +// goroutines. +type RoundTripper interface { + // RoundTrip executes a single HTTP transaction, returning + // a Response for the provided Request. + // + // RoundTrip should not attempt to interpret the response. In + // particular, RoundTrip must return err == nil if it obtained + // a response, regardless of the response's HTTP status code. + // A non-nil err should be reserved for failure to obtain a + // response. Similarly, RoundTrip should not attempt to + // handle higher-level protocol details such as redirects, + // authentication, or cookies. + // + // RoundTrip should not modify the request, except for + // consuming and closing the Request's Body. RoundTrip may + // read fields of the request in a separate goroutine. Callers + // should not mutate or reuse the request until the Response's + // Body has been closed. + // + // RoundTrip must always close the body, including on errors, + // but depending on the implementation may do so in a separate + // goroutine even after RoundTrip returns. This means that + // callers wanting to reuse the body for subsequent requests + // must arrange to wait for the Close call before doing so. + // + // The Request's URL and Header fields must be initialized. + RoundTrip(*Request) (*Response, error) +} + +// refererForURL returns a referer without any authentication info or +// an empty string if lastReq scheme is https and newReq scheme is http. +func refererForURL(lastReq, newReq *url.URL) string { + // https://tools.ietf.org/html/rfc7231#section-5.5.2 + // "Clients SHOULD NOT include a Referer header field in a + // (non-secure) HTTP request if the referring page was + // transferred with a secure protocol." + if lastReq.Scheme == "https" && newReq.Scheme == "http" { + return "" + } + referer := lastReq.String() + if lastReq.User != nil { + // This is not very efficient, but is the best we can + // do without: + // - introducing a new method on URL + // - creating a race condition + // - copying the URL struct manually, which would cause + // maintenance problems down the line + auth := lastReq.User.String() + "@" + referer = strings.Replace(referer, auth, "", 1) + } + return referer +} + +// didTimeout is non-nil only if err != nil. +func (c *Client) send(req *Request, deadline time.Time) (resp *Response, didTimeout func() bool, err error) { + if c.Jar != nil { + for _, cookie := range c.Jar.Cookies(req.URL) { + req.AddCookie(cookie) + } + } + resp, didTimeout, err = send(req, c.transport(), deadline) + if err != nil { + return nil, didTimeout, err + } + if c.Jar != nil { + if rc := resp.Cookies(); len(rc) > 0 { + c.Jar.SetCookies(req.URL, rc) + } + } + return resp, nil, nil +} + +func (c *Client) deadline() time.Time { + if c.Timeout > 0 { + return time.Now().Add(c.Timeout) + } + return time.Time{} +} + +func (c *Client) transport() RoundTripper { + if c.Transport != nil { + return c.Transport + } + return DefaultTransport +} + +// send issues an HTTP request. +// Caller should close resp.Body when done reading from it. +func send(ireq *Request, rt RoundTripper, deadline time.Time) (resp *Response, didTimeout func() bool, err error) { + req := ireq // req is either the original request, or a modified fork + + if rt == nil { + req.closeBody() + return nil, alwaysFalse, errors.New("http: no Client.Transport or DefaultTransport") + } + + if req.URL == nil { + req.closeBody() + return nil, alwaysFalse, errors.New("http: nil Request.URL") + } + + if req.RequestURI != "" { + req.closeBody() + return nil, alwaysFalse, errors.New("http: Request.RequestURI can't be set in client requests") + } + + // forkReq forks req into a shallow clone of ireq the first + // time it's called. + forkReq := func() { + if ireq == req { + req = new(Request) + *req = *ireq // shallow clone + } + } + + // Most the callers of send (Get, Post, et al) don't need + // Headers, leaving it uninitialized. We guarantee to the + // Transport that this has been initialized, though. + if req.Header == nil { + forkReq() + req.Header = make(Header) + } + + if u := req.URL.User; u != nil && req.Header.Get("Authorization") == "" { + username := u.Username() + password, _ := u.Password() + forkReq() + req.Header = cloneOrMakeHeader(ireq.Header) + req.Header.Set("Authorization", "Basic "+basicAuth(username, password)) + } + + if !deadline.IsZero() { + forkReq() + } + stopTimer, didTimeout := setRequestCancel(req, rt, deadline) + + resp, err = rt.RoundTrip(req) + if err != nil { + stopTimer() + if resp != nil { + log.Printf("RoundTripper returned a response & error; ignoring response") + } + if tlsErr, ok := err.(tls.RecordHeaderError); ok { + // If we get a bad TLS record header, check to see if the + // response looks like HTTP and give a more helpful error. + // See golang.org/issue/11111. + if string(tlsErr.RecordHeader[:]) == "HTTP/" { + err = errors.New("http: server gave HTTP response to HTTPS client") + } + } + return nil, didTimeout, err + } + if resp == nil { + return nil, didTimeout, fmt.Errorf("http: RoundTripper implementation (%T) returned a nil *Response with a nil error", rt) + } + if resp.Body == nil { + // The documentation on the Body field says “The http Client and Transport + // guarantee that Body is always non-nil, even on responses without a body + // or responses with a zero-length body.” Unfortunately, we didn't document + // that same constraint for arbitrary RoundTripper implementations, and + // RoundTripper implementations in the wild (mostly in tests) assume that + // they can use a nil Body to mean an empty one (similar to Request.Body). + // (See https://golang.org/issue/38095.) + // + // If the ContentLength allows the Body to be empty, fill in an empty one + // here to ensure that it is non-nil. + if resp.ContentLength > 0 && req.Method != "HEAD" { + return nil, didTimeout, fmt.Errorf("http: RoundTripper implementation (%T) returned a *Response with content length %d but a nil Body", rt, resp.ContentLength) + } + resp.Body = io.NopCloser(strings.NewReader("")) + } + if !deadline.IsZero() { + resp.Body = &cancelTimerBody{ + stop: stopTimer, + rc: resp.Body, + reqDidTimeout: didTimeout, + } + } + return resp, nil, nil +} + +// timeBeforeContextDeadline reports whether the non-zero Time t is +// before ctx's deadline, if any. If ctx does not have a deadline, it +// always reports true (the deadline is considered infinite). +func timeBeforeContextDeadline(t time.Time, ctx context.Context) bool { + d, ok := ctx.Deadline() + if !ok { + return true + } + return t.Before(d) +} + +// knownRoundTripperImpl reports whether rt is a RoundTripper that's +// maintained by the Go team and known to implement the latest +// optional semantics (notably contexts). The Request is used +// to check whether this particular request is using an alternate protocol, +// in which case we need to check the RoundTripper for that protocol. +func knownRoundTripperImpl(rt RoundTripper, req *Request) bool { + switch t := rt.(type) { + case *Transport: + if altRT := t.alternateRoundTripper(req); altRT != nil { + return knownRoundTripperImpl(altRT, req) + } + return true + case *http2Transport, http2noDialH2RoundTripper: + return true + } + // There's a very minor chance of a false positive with this. + // Instead of detecting our golang.org/x/net/http2.Transport, + // it might detect a Transport type in a different http2 + // package. But I know of none, and the only problem would be + // some temporarily leaked goroutines if the transport didn't + // support contexts. So this is a good enough heuristic: + if reflect.TypeOf(rt).String() == "*http2.Transport" { + return true + } + return false +} + +// setRequestCancel sets req.Cancel and adds a deadline context to req +// if deadline is non-zero. The RoundTripper's type is used to +// determine whether the legacy CancelRequest behavior should be used. +// +// As background, there are three ways to cancel a request: +// First was Transport.CancelRequest. (deprecated) +// Second was Request.Cancel. +// Third was Request.Context. +// This function populates the second and third, and uses the first if it really needs to. +func setRequestCancel(req *Request, rt RoundTripper, deadline time.Time) (stopTimer func(), didTimeout func() bool) { + if deadline.IsZero() { + return nop, alwaysFalse + } + knownTransport := knownRoundTripperImpl(rt, req) + oldCtx := req.Context() + + if req.Cancel == nil && knownTransport { + // If they already had a Request.Context that's + // expiring sooner, do nothing: + if !timeBeforeContextDeadline(deadline, oldCtx) { + return nop, alwaysFalse + } + + var cancelCtx func() + req.ctx, cancelCtx = context.WithDeadline(oldCtx, deadline) + return cancelCtx, func() bool { return time.Now().After(deadline) } + } + initialReqCancel := req.Cancel // the user's original Request.Cancel, if any + + var cancelCtx func() + if oldCtx := req.Context(); timeBeforeContextDeadline(deadline, oldCtx) { + req.ctx, cancelCtx = context.WithDeadline(oldCtx, deadline) + } + + cancel := make(chan struct{}) + req.Cancel = cancel + + doCancel := func() { + // The second way in the func comment above: + close(cancel) + // The first way, used only for RoundTripper + // implementations written before Go 1.5 or Go 1.6. + type canceler interface{ CancelRequest(*Request) } + if v, ok := rt.(canceler); ok { + v.CancelRequest(req) + } + } + + stopTimerCh := make(chan struct{}) + var once sync.Once + stopTimer = func() { + once.Do(func() { + close(stopTimerCh) + if cancelCtx != nil { + cancelCtx() + } + }) + } + + timer := time.NewTimer(time.Until(deadline)) + var timedOut atomicBool + + go func() { + select { + case <-initialReqCancel: + doCancel() + timer.Stop() + case <-timer.C: + timedOut.setTrue() + doCancel() + case <-stopTimerCh: + timer.Stop() + } + }() + + return stopTimer, timedOut.isSet +} + +// See 2 (end of page 4) https://www.ietf.org/rfc/rfc2617.txt +// "To receive authorization, the client sends the userid and password, +// separated by a single colon (":") character, within a base64 +// encoded string in the credentials." +// It is not meant to be urlencoded. +func basicAuth(username, password string) string { + auth := username + ":" + password + return base64.StdEncoding.EncodeToString([]byte(auth)) +} + +// Get issues a GET to the specified URL. If the response is one of +// the following redirect codes, Get follows the redirect, up to a +// maximum of 10 redirects: +// +// 301 (Moved Permanently) +// 302 (Found) +// 303 (See Other) +// 307 (Temporary Redirect) +// 308 (Permanent Redirect) +// +// An error is returned if there were too many redirects or if there +// was an HTTP protocol error. A non-2xx response doesn't cause an +// error. Any returned error will be of type *url.Error. The url.Error +// value's Timeout method will report true if request timed out or was +// canceled. +// +// When err is nil, resp always contains a non-nil resp.Body. +// Caller should close resp.Body when done reading from it. +// +// Get is a wrapper around DefaultClient.Get. +// +// To make a request with custom headers, use NewRequest and +// DefaultClient.Do. +func Get(url string) (resp *Response, err error) { + return DefaultClient.Get(url) +} + +// Get issues a GET to the specified URL. If the response is one of the +// following redirect codes, Get follows the redirect after calling the +// Client's CheckRedirect function: +// +// 301 (Moved Permanently) +// 302 (Found) +// 303 (See Other) +// 307 (Temporary Redirect) +// 308 (Permanent Redirect) +// +// An error is returned if the Client's CheckRedirect function fails +// or if there was an HTTP protocol error. A non-2xx response doesn't +// cause an error. Any returned error will be of type *url.Error. The +// url.Error value's Timeout method will report true if the request +// timed out. +// +// When err is nil, resp always contains a non-nil resp.Body. +// Caller should close resp.Body when done reading from it. +// +// To make a request with custom headers, use NewRequest and Client.Do. +func (c *Client) Get(url string) (resp *Response, err error) { + req, err := NewRequest("GET", url, nil) + if err != nil { + return nil, err + } + return c.Do(req) +} + +func alwaysFalse() bool { return false } + +// ErrUseLastResponse can be returned by Client.CheckRedirect hooks to +// control how redirects are processed. If returned, the next request +// is not sent and the most recent response is returned with its body +// unclosed. +var ErrUseLastResponse = errors.New("net/http: use last response") + +// checkRedirect calls either the user's configured CheckRedirect +// function, or the default. +func (c *Client) checkRedirect(req *Request, via []*Request) error { + fn := c.CheckRedirect + if fn == nil { + fn = defaultCheckRedirect + } + return fn(req, via) +} + +// redirectBehavior describes what should happen when the +// client encounters a 3xx status code from the server +func redirectBehavior(reqMethod string, resp *Response, ireq *Request) (redirectMethod string, shouldRedirect, includeBody bool) { + switch resp.StatusCode { + case 301, 302, 303: + redirectMethod = reqMethod + shouldRedirect = true + includeBody = false + + // RFC 2616 allowed automatic redirection only with GET and + // HEAD requests. RFC 7231 lifts this restriction, but we still + // restrict other methods to GET to maintain compatibility. + // See Issue 18570. + if reqMethod != "GET" && reqMethod != "HEAD" { + redirectMethod = "GET" + } + case 307, 308: + redirectMethod = reqMethod + shouldRedirect = true + includeBody = true + + // Treat 307 and 308 specially, since they're new in + // Go 1.8, and they also require re-sending the request body. + if resp.Header.Get("Location") == "" { + // 308s have been observed in the wild being served + // without Location headers. Since Go 1.7 and earlier + // didn't follow these codes, just stop here instead + // of returning an error. + // See Issue 17773. + shouldRedirect = false + break + } + if ireq.GetBody == nil && ireq.outgoingLength() != 0 { + // We had a request body, and 307/308 require + // re-sending it, but GetBody is not defined. So just + // return this response to the user instead of an + // error, like we did in Go 1.7 and earlier. + shouldRedirect = false + } + } + return redirectMethod, shouldRedirect, includeBody +} + +// urlErrorOp returns the (*url.Error).Op value to use for the +// provided (*Request).Method value. +func urlErrorOp(method string) string { + if method == "" { + return "Get" + } + return method[:1] + strings.ToLower(method[1:]) +} + +// Do sends an HTTP request and returns an HTTP response, following +// policy (such as redirects, cookies, auth) as configured on the +// client. +// +// An error is returned if caused by client policy (such as +// CheckRedirect), or failure to speak HTTP (such as a network +// connectivity problem). A non-2xx status code doesn't cause an +// error. +// +// If the returned error is nil, the Response will contain a non-nil +// Body which the user is expected to close. If the Body is not both +// read to EOF and closed, the Client's underlying RoundTripper +// (typically Transport) may not be able to re-use a persistent TCP +// connection to the server for a subsequent "keep-alive" request. +// +// The request Body, if non-nil, will be closed by the underlying +// Transport, even on errors. +// +// On error, any Response can be ignored. A non-nil Response with a +// non-nil error only occurs when CheckRedirect fails, and even then +// the returned Response.Body is already closed. +// +// Generally Get, Post, or PostForm will be used instead of Do. +// +// If the server replies with a redirect, the Client first uses the +// CheckRedirect function to determine whether the redirect should be +// followed. If permitted, a 301, 302, or 303 redirect causes +// subsequent requests to use HTTP method GET +// (or HEAD if the original request was HEAD), with no body. +// A 307 or 308 redirect preserves the original HTTP method and body, +// provided that the Request.GetBody function is defined. +// The NewRequest function automatically sets GetBody for common +// standard library body types. +// +// Any returned error will be of type *url.Error. The url.Error +// value's Timeout method will report true if request timed out or was +// canceled. +func (c *Client) Do(req *Request) (*Response, error) { + return c.do(req) +} + +var testHookClientDoResult func(retres *Response, reterr error) + +func (c *Client) do(req *Request) (retres *Response, reterr error) { + if testHookClientDoResult != nil { + defer func() { testHookClientDoResult(retres, reterr) }() + } + if req.URL == nil { + req.closeBody() + return nil, &url.Error{ + Op: urlErrorOp(req.Method), + Err: errors.New("http: nil Request.URL"), + } + } + + var ( + deadline = c.deadline() + reqs []*Request + resp *Response + copyHeaders = c.makeHeadersCopier(req) + reqBodyClosed = false // have we closed the current req.Body? + + // Redirect behavior: + redirectMethod string + includeBody bool + ) + uerr := func(err error) error { + // the body may have been closed already by c.send() + if !reqBodyClosed { + req.closeBody() + } + var urlStr string + if resp != nil && resp.Request != nil { + urlStr = stripPassword(resp.Request.URL) + } else { + urlStr = stripPassword(req.URL) + } + return &url.Error{ + Op: urlErrorOp(reqs[0].Method), + URL: urlStr, + Err: err, + } + } + for { + // For all but the first request, create the next + // request hop and replace req. + if len(reqs) > 0 { + loc := resp.Header.Get("Location") + if loc == "" { + resp.closeBody() + return nil, uerr(fmt.Errorf("%d response missing Location header", resp.StatusCode)) + } + u, err := req.URL.Parse(loc) + if err != nil { + resp.closeBody() + return nil, uerr(fmt.Errorf("failed to parse Location header %q: %v", loc, err)) + } + host := "" + if req.Host != "" && req.Host != req.URL.Host { + // If the caller specified a custom Host header and the + // redirect location is relative, preserve the Host header + // through the redirect. See issue #22233. + if u, _ := url.Parse(loc); u != nil && !u.IsAbs() { + host = req.Host + } + } + ireq := reqs[0] + req = &Request{ + Method: redirectMethod, + Response: resp, + URL: u, + Header: make(Header), + Host: host, + Cancel: ireq.Cancel, + ctx: ireq.ctx, + } + if includeBody && ireq.GetBody != nil { + req.Body, err = ireq.GetBody() + if err != nil { + resp.closeBody() + return nil, uerr(err) + } + req.ContentLength = ireq.ContentLength + } + + // Copy original headers before setting the Referer, + // in case the user set Referer on their first request. + // If they really want to override, they can do it in + // their CheckRedirect func. + copyHeaders(req) + + // Add the Referer header from the most recent + // request URL to the new one, if it's not https->http: + if ref := refererForURL(reqs[len(reqs)-1].URL, req.URL); ref != "" { + req.Header.Set("Referer", ref) + } + err = c.checkRedirect(req, reqs) + + // Sentinel error to let users select the + // previous response, without closing its + // body. See Issue 10069. + if err == ErrUseLastResponse { + return resp, nil + } + + // Close the previous response's body. But + // read at least some of the body so if it's + // small the underlying TCP connection will be + // re-used. No need to check for errors: if it + // fails, the Transport won't reuse it anyway. + const maxBodySlurpSize = 2 << 10 + if resp.ContentLength == -1 || resp.ContentLength <= maxBodySlurpSize { + io.CopyN(io.Discard, resp.Body, maxBodySlurpSize) + } + resp.Body.Close() + + if err != nil { + // Special case for Go 1 compatibility: return both the response + // and an error if the CheckRedirect function failed. + // See https://golang.org/issue/3795 + // The resp.Body has already been closed. + ue := uerr(err) + ue.(*url.Error).URL = loc + return resp, ue + } + } + + reqs = append(reqs, req) + var err error + var didTimeout func() bool + if resp, didTimeout, err = c.send(req, deadline); err != nil { + // c.send() always closes req.Body + reqBodyClosed = true + if !deadline.IsZero() && didTimeout() { + err = &httpError{ + // TODO: early in cycle: s/Client.Timeout exceeded/timeout or context cancellation/ + err: err.Error() + " (Client.Timeout exceeded while awaiting headers)", + timeout: true, + } + } + return nil, uerr(err) + } + + var shouldRedirect bool + redirectMethod, shouldRedirect, includeBody = redirectBehavior(req.Method, resp, reqs[0]) + if !shouldRedirect { + return resp, nil + } + + req.closeBody() + } +} + +// makeHeadersCopier makes a function that copies headers from the +// initial Request, ireq. For every redirect, this function must be called +// so that it can copy headers into the upcoming Request. +func (c *Client) makeHeadersCopier(ireq *Request) func(*Request) { + // The headers to copy are from the very initial request. + // We use a closured callback to keep a reference to these original headers. + var ( + ireqhdr = cloneOrMakeHeader(ireq.Header) + icookies map[string][]*Cookie + ) + if c.Jar != nil && ireq.Header.Get("Cookie") != "" { + icookies = make(map[string][]*Cookie) + for _, c := range ireq.Cookies() { + icookies[c.Name] = append(icookies[c.Name], c) + } + } + + preq := ireq // The previous request + return func(req *Request) { + // If Jar is present and there was some initial cookies provided + // via the request header, then we may need to alter the initial + // cookies as we follow redirects since each redirect may end up + // modifying a pre-existing cookie. + // + // Since cookies already set in the request header do not contain + // information about the original domain and path, the logic below + // assumes any new set cookies override the original cookie + // regardless of domain or path. + // + // See https://golang.org/issue/17494 + if c.Jar != nil && icookies != nil { + var changed bool + resp := req.Response // The response that caused the upcoming redirect + for _, c := range resp.Cookies() { + if _, ok := icookies[c.Name]; ok { + delete(icookies, c.Name) + changed = true + } + } + if changed { + ireqhdr.Del("Cookie") + var ss []string + for _, cs := range icookies { + for _, c := range cs { + ss = append(ss, c.Name+"="+c.Value) + } + } + sort.Strings(ss) // Ensure deterministic headers + ireqhdr.Set("Cookie", strings.Join(ss, "; ")) + } + } + + // Copy the initial request's Header values + // (at least the safe ones). + for k, vv := range ireqhdr { + if shouldCopyHeaderOnRedirect(k, preq.URL, req.URL) { + req.Header[k] = vv + } + } + + preq = req // Update previous Request with the current request + } +} + +func defaultCheckRedirect(req *Request, via []*Request) error { + if len(via) >= 10 { + return errors.New("stopped after 10 redirects") + } + return nil +} + +// Post issues a POST to the specified URL. +// +// Caller should close resp.Body when done reading from it. +// +// If the provided body is an io.Closer, it is closed after the +// request. +// +// Post is a wrapper around DefaultClient.Post. +// +// To set custom headers, use NewRequest and DefaultClient.Do. +// +// See the Client.Do method documentation for details on how redirects +// are handled. +func Post(url, contentType string, body io.Reader) (resp *Response, err error) { + return DefaultClient.Post(url, contentType, body) +} + +// Post issues a POST to the specified URL. +// +// Caller should close resp.Body when done reading from it. +// +// If the provided body is an io.Closer, it is closed after the +// request. +// +// To set custom headers, use NewRequest and Client.Do. +// +// See the Client.Do method documentation for details on how redirects +// are handled. +func (c *Client) Post(url, contentType string, body io.Reader) (resp *Response, err error) { + req, err := NewRequest("POST", url, body) + if err != nil { + return nil, err + } + req.Header.Set("Content-Type", contentType) + return c.Do(req) +} + +// PostForm issues a POST to the specified URL, with data's keys and +// values URL-encoded as the request body. +// +// The Content-Type header is set to application/x-www-form-urlencoded. +// To set other headers, use NewRequest and DefaultClient.Do. +// +// When err is nil, resp always contains a non-nil resp.Body. +// Caller should close resp.Body when done reading from it. +// +// PostForm is a wrapper around DefaultClient.PostForm. +// +// See the Client.Do method documentation for details on how redirects +// are handled. +func PostForm(url string, data url.Values) (resp *Response, err error) { + return DefaultClient.PostForm(url, data) +} + +// PostForm issues a POST to the specified URL, +// with data's keys and values URL-encoded as the request body. +// +// The Content-Type header is set to application/x-www-form-urlencoded. +// To set other headers, use NewRequest and Client.Do. +// +// When err is nil, resp always contains a non-nil resp.Body. +// Caller should close resp.Body when done reading from it. +// +// See the Client.Do method documentation for details on how redirects +// are handled. +func (c *Client) PostForm(url string, data url.Values) (resp *Response, err error) { + return c.Post(url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode())) +} + +// Head issues a HEAD to the specified URL. If the response is one of +// the following redirect codes, Head follows the redirect, up to a +// maximum of 10 redirects: +// +// 301 (Moved Permanently) +// 302 (Found) +// 303 (See Other) +// 307 (Temporary Redirect) +// 308 (Permanent Redirect) +// +// Head is a wrapper around DefaultClient.Head +func Head(url string) (resp *Response, err error) { + return DefaultClient.Head(url) +} + +// Head issues a HEAD to the specified URL. If the response is one of the +// following redirect codes, Head follows the redirect after calling the +// Client's CheckRedirect function: +// +// 301 (Moved Permanently) +// 302 (Found) +// 303 (See Other) +// 307 (Temporary Redirect) +// 308 (Permanent Redirect) +func (c *Client) Head(url string) (resp *Response, err error) { + req, err := NewRequest("HEAD", url, nil) + if err != nil { + return nil, err + } + return c.Do(req) +} + +// CloseIdleConnections closes any connections on its Transport which +// were previously connected from previous requests but are now +// sitting idle in a "keep-alive" state. It does not interrupt any +// connections currently in use. +// +// If the Client's Transport does not have a CloseIdleConnections method +// then this method does nothing. +func (c *Client) CloseIdleConnections() { + type closeIdler interface { + CloseIdleConnections() + } + if tr, ok := c.transport().(closeIdler); ok { + tr.CloseIdleConnections() + } +} + +// cancelTimerBody is an io.ReadCloser that wraps rc with two features: +// 1) on Read error or close, the stop func is called. +// 2) On Read failure, if reqDidTimeout is true, the error is wrapped and +// marked as net.Error that hit its timeout. +type cancelTimerBody struct { + stop func() // stops the time.Timer waiting to cancel the request + rc io.ReadCloser + reqDidTimeout func() bool +} + +func (b *cancelTimerBody) Read(p []byte) (n int, err error) { + n, err = b.rc.Read(p) + if err == nil { + return n, nil + } + b.stop() + if err == io.EOF { + return n, err + } + if b.reqDidTimeout() { + err = &httpError{ + err: err.Error() + " (Client.Timeout or context cancellation while reading body)", + timeout: true, + } + } + return n, err +} + +func (b *cancelTimerBody) Close() error { + err := b.rc.Close() + b.stop() + return err +} + +func shouldCopyHeaderOnRedirect(headerKey string, initial, dest *url.URL) bool { + switch CanonicalHeaderKey(headerKey) { + case "Authorization", "Www-Authenticate", "Cookie", "Cookie2": + // Permit sending auth/cookie headers from "foo.com" + // to "sub.foo.com". + + // Note that we don't send all cookies to subdomains + // automatically. This function is only used for + // Cookies set explicitly on the initial outgoing + // client request. Cookies automatically added via the + // CookieJar mechanism continue to follow each + // cookie's scope as set by Set-Cookie. But for + // outgoing requests with the Cookie header set + // directly, we don't know their scope, so we assume + // it's for *.domain.com. + + ihost := canonicalAddr(initial) + dhost := canonicalAddr(dest) + return isDomainOrSubdomain(dhost, ihost) + } + // All other headers are copied: + return true +} + +// isDomainOrSubdomain reports whether sub is a subdomain (or exact +// match) of the parent domain. +// +// Both domains must already be in canonical form. +func isDomainOrSubdomain(sub, parent string) bool { + if sub == parent { + return true + } + // If sub is "foo.example.com" and parent is "example.com", + // that means sub must end in "."+parent. + // Do it without allocating. + if !strings.HasSuffix(sub, parent) { + return false + } + return sub[len(sub)-len(parent)-1] == '.' +} + +func stripPassword(u *url.URL) string { + _, passSet := u.User.Password() + if passSet { + return strings.Replace(u.String(), u.User.String()+"@", u.User.Username()+":***@", 1) + } + return u.String() +} |