blob: 851a049538db39051026f5be8b865e6d2203a61d [file] [log] [blame]
package main
var src = `
// Code generated by golang.org/x/tools/cmd/bundle command:
// $ bundle net/http http
// Package http provides HTTP client and server implementations.
//
// Get, Head, Post, and PostForm make HTTP (or HTTPS) requests:
//
// resp, err := http.Get("http://example.com/")
// ...
// resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf)
// ...
// resp, err := http.PostForm("http://example.com/form",
// url.Values{"key": {"Value"}, "id": {"123"}})
//
// The client must close the response body when finished with it:
//
// resp, err := http.Get("http://example.com/")
// if err != nil {
// // handle error
// }
// defer resp.Body.Close()
// body, err := ioutil.ReadAll(resp.Body)
// // ...
//
// For control over HTTP client headers, redirect policy, and other
// settings, create a Client:
//
// client := &http.Client{
// CheckRedirect: redirectPolicyFunc,
// }
//
// resp, err := client.Get("http://example.com")
// // ...
//
// req, err := http.NewRequest("GET", "http://example.com", nil)
// // ...
// req.Header.Add("If-None-Match", ` + "`" + `W/"wyzzy"` + "`" + `)
// resp, err := client.Do(req)
// // ...
//
// For control over proxies, TLS configuration, keep-alives,
// compression, and other settings, create a Transport:
//
// tr := &http.Transport{
// TLSClientConfig: &tls.Config{RootCAs: pool},
// DisableCompression: true,
// }
// client := &http.Client{Transport: tr}
// resp, err := client.Get("https://example.com")
//
// Clients and Transports are safe for concurrent use by multiple
// goroutines and for efficiency should only be created once and re-used.
//
// ListenAndServe starts an HTTP server with a given address and handler.
// The handler is usually nil, which means to use DefaultServeMux.
// Handle and HandleFunc add handlers to DefaultServeMux:
//
// http.Handle("/foo", fooHandler)
//
// http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
// fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
// })
//
// log.Fatal(http.ListenAndServe(":8080", nil))
//
// More control over the server's behavior is available by creating a
// custom Server:
//
// s := &http.Server{
// Addr: ":8080",
// Handler: myHandler,
// ReadTimeout: 10 * time.Second,
// WriteTimeout: 10 * time.Second,
// MaxHeaderBytes: 1 << 20,
// }
// log.Fatal(s.ListenAndServe())
//
package http
import (
"bufio"
"bytes"
"compress/gzip"
"crypto/tls"
"encoding/base64"
"encoding/binary"
"errors"
"fmt"
"io"
"io/ioutil"
"log"
"mime"
"mime/multipart"
"net"
"net/http/internal"
"net/textproto"
"net/url"
"os"
"path"
"path/filepath"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
"unicode/utf8"
)
// 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.
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 and
// CheckRedirect's error (wrapped in a url.Error) instead of
// issuing the Request req.
//
// 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.
// If Jar is nil, cookies are not sent in requests and ignored
// in responses.
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's Transport must support the CancelRequest
// method or Client will return errors when attempting to make
// a request with Get, Head, Post, or Do. Client's default
// Transport (DefaultTransport) supports 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
// the Response for the request req. 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 Body, including on errors. The
// request's URL and Header fields are guaranteed to be
// initialized.
RoundTrip(*Request) (*Response, error)
}
// Given a string of the form "host", "host:port", or "[ipv6::address]:port",
// return true if the string includes a port.
func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }
// 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 {
if lastReq.Scheme == "https" && newReq.Scheme == "http" {
return ""
}
referer := lastReq.String()
if lastReq.User != nil {
auth := lastReq.User.String() + "@"
referer = strings.Replace(referer, auth, "", 1)
}
return referer
}
// Used in Send to implement io.ReadCloser by bundling together the
// bufio.Reader through which we read the response, and the underlying
// network connection.
type readClose struct {
io.Reader
io.Closer
}
func (c *Client) send(req *Request) (*Response, error) {
if c.Jar != nil {
for _, cookie := range c.Jar.Cookies(req.URL) {
req.AddCookie(cookie)
}
}
resp, err := send(req, c.transport())
if err != nil {
return nil, err
}
if c.Jar != nil {
if rc := resp.Cookies(); len(rc) > 0 {
c.Jar.SetCookies(req.URL, rc)
}
}
return resp, err
}
// Do sends an HTTP request and returns an HTTP response, following
// policy (e.g. redirects, cookies, auth) as configured on the client.
//
// An error is returned if caused by client policy (such as
// CheckRedirect), or if there was an HTTP protocol error.
// A non-2xx response doesn't cause an error.
//
// When err is nil, resp always contains a non-nil resp.Body.
//
// Callers should close resp.Body when done reading from it. If
// resp.Body is not 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.
//
// Generally Get, Post, or PostForm will be used instead of Do.
func (c *Client) Do(req *Request) (resp *Response, err error) {
if req.Method == "GET" || req.Method == "HEAD" {
return c.doFollowingRedirects(req, shouldRedirectGet)
}
if req.Method == "POST" || req.Method == "PUT" {
return c.doFollowingRedirects(req, shouldRedirectPost)
}
return c.send(req)
}
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(req *Request, t RoundTripper) (resp *Response, err error) {
if t == nil {
req.closeBody()
return nil, errors.New("http: no Client.Transport or DefaultTransport")
}
if req.URL == nil {
req.closeBody()
return nil, errors.New("http: nil Request.URL")
}
if req.RequestURI != "" {
req.closeBody()
return nil, errors.New("http: Request.RequestURI can't be set in client requests.")
}
if req.Header == nil {
req.Header = make(Header)
}
if u := req.URL.User; u != nil && req.Header.Get("Authorization") == "" {
username := u.Username()
password, _ := u.Password()
req.Header.Set("Authorization", "Basic "+basicAuth(username, password))
}
resp, err = t.RoundTrip(req)
if err != nil {
if resp != nil {
log.Printf("RoundTripper returned a response & error; ignoring response")
}
return nil, err
}
return resp, nil
}
// See 2 (end of page 4) http://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))
}
// True if the specified HTTP status code is one for which the Get utility should
// automatically redirect.
func shouldRedirectGet(statusCode int) bool {
switch statusCode {
case StatusMovedPermanently, StatusFound, StatusSeeOther, StatusTemporaryRedirect:
return true
}
return false
}
// True if the specified HTTP status code is one for which the Post utility should
// automatically redirect.
func shouldRedirectPost(statusCode int) bool {
switch statusCode {
case StatusFound, StatusSeeOther:
return true
}
return false
}
// 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)
//
// 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.
//
// 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)
//
// 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.
//
// 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.doFollowingRedirects(req, shouldRedirectGet)
}
func alwaysFalse() bool { return false }
func (c *Client) doFollowingRedirects(ireq *Request, shouldRedirect func(int) bool) (resp *Response, err error) {
var base *url.URL
redirectChecker := c.CheckRedirect
if redirectChecker == nil {
redirectChecker = defaultCheckRedirect
}
var via []*Request
if ireq.URL == nil {
ireq.closeBody()
return nil, errors.New("http: nil Request.URL")
}
var reqmu sync.Mutex // guards req
req := ireq
var timer *time.Timer
var atomicWasCanceled int32 // atomic bool (1 or 0)
var wasCanceled = alwaysFalse
if c.Timeout > 0 {
wasCanceled = func() bool { return atomic.LoadInt32(&atomicWasCanceled) != 0 }
type canceler interface {
CancelRequest(*Request)
}
tr, ok := c.transport().(canceler)
if !ok {
return nil, fmt.Errorf("net/http: Client Transport of type %T doesn't support CancelRequest; Timeout not supported", c.transport())
}
timer = time.AfterFunc(c.Timeout, func() {
atomic.StoreInt32(&atomicWasCanceled, 1)
reqmu.Lock()
defer reqmu.Unlock()
tr.CancelRequest(req)
})
}
urlStr := ""
redirectFailed := false
for redirect := 0; ; redirect++ {
if redirect != 0 {
nreq := new(Request)
nreq.Method = ireq.Method
if ireq.Method == "POST" || ireq.Method == "PUT" {
nreq.Method = "GET"
}
nreq.Header = make(Header)
nreq.URL, err = base.Parse(urlStr)
if err != nil {
break
}
if len(via) > 0 {
lastReq := via[len(via)-1]
if ref := refererForURL(lastReq.URL, nreq.URL); ref != "" {
nreq.Header.Set("Referer", ref)
}
err = redirectChecker(nreq, via)
if err != nil {
redirectFailed = true
break
}
}
reqmu.Lock()
req = nreq
reqmu.Unlock()
}
urlStr = req.URL.String()
if resp, err = c.send(req); err != nil {
if wasCanceled() {
err = &httpError{
err: err.Error() + " (Client.Timeout exceeded while awaiting headers)",
timeout: true,
}
}
break
}
if shouldRedirect(resp.StatusCode) {
// Read the body if small so underlying TCP connection will be re-used.
// No need to check for errors: if it fails, Transport won't reuse it anyway.
const maxBodySlurpSize = 2 << 10
if resp.ContentLength == -1 || resp.ContentLength <= maxBodySlurpSize {
io.CopyN(ioutil.Discard, resp.Body, maxBodySlurpSize)
}
resp.Body.Close()
if urlStr = resp.Header.Get("Location"); urlStr == "" {
err = fmt.Errorf("%d response missing Location header", resp.StatusCode)
break
}
base = req.URL
via = append(via, req)
continue
}
if timer != nil {
resp.Body = &cancelTimerBody{
t: timer,
rc: resp.Body,
reqWasCanceled: wasCanceled,
}
}
return resp, nil
}
method := ireq.Method
urlErr := &url.Error{
Op: method[0:1] + strings.ToLower(method[1:]),
URL: urlStr,
Err: err,
}
if redirectFailed {
return resp, urlErr
}
if resp != nil {
resp.Body.Close()
}
return nil, urlErr
}
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.
func Post(url string, bodyType string, body io.Reader) (resp *Response, err error) {
return DefaultClient.Post(url, bodyType, 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.
func (c *Client) Post(url string, bodyType 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", bodyType)
return c.doFollowingRedirects(req, shouldRedirectPost)
}
// 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.
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 DefaultClient.Do.
//
// When err is nil, resp always contains a non-nil resp.Body.
// Caller should close resp.Body when done reading from it.
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)
//
// 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)
func (c *Client) Head(url string) (resp *Response, err error) {
req, err := NewRequest("HEAD", url, nil)
if err != nil {
return nil, err
}
return c.doFollowingRedirects(req, shouldRedirectGet)
}
// cancelTimerBody is an io.ReadCloser that wraps rc with two features:
// 1) on Read EOF or Close, the timer t is Stopped,
// 2) On Read failure, if reqWasCanceled is true, the error is wrapped and
// marked as net.Error that hit its timeout.
type cancelTimerBody struct {
t *time.Timer
rc io.ReadCloser
reqWasCanceled func() bool
}
func (b *cancelTimerBody) Read(p []byte) (n int, err error) {
n, err = b.rc.Read(p)
if err == io.EOF {
b.t.Stop()
} else if err != nil && b.reqWasCanceled() {
return n, &httpError{
err: err.Error() + " (Client.Timeout exceeded while reading body)",
timeout: true,
}
}
return
}
func (b *cancelTimerBody) Close() error {
err := b.rc.Close()
b.t.Stop()
return err
}
// A Cookie represents an HTTP cookie as sent in the Set-Cookie header of an
// HTTP response or the Cookie header of an HTTP request.
//
// See http://tools.ietf.org/html/rfc6265 for details.
type Cookie struct {
Name string
Value string
Path string // optional
Domain string // optional
Expires time.Time // optional
RawExpires string // for reading cookies only
// MaxAge=0 means no 'Max-Age' attribute specified.
// MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'
// MaxAge>0 means Max-Age attribute present and given in seconds
MaxAge int
Secure bool
HttpOnly bool
Raw string
Unparsed []string // Raw text of unparsed attribute-value pairs
}
// readSetCookies parses all "Set-Cookie" values from
// the header h and returns the successfully parsed Cookies.
func readSetCookies(h Header) []*Cookie {
cookies := []*Cookie{}
for _, line := range h["Set-Cookie"] {
parts := strings.Split(strings.TrimSpace(line), ";")
if len(parts) == 1 && parts[0] == "" {
continue
}
parts[0] = strings.TrimSpace(parts[0])
j := strings.Index(parts[0], "=")
if j < 0 {
continue
}
name, value := parts[0][:j], parts[0][j+1:]
if !isCookieNameValid(name) {
continue
}
value, success := parseCookieValue(value, true)
if !success {
continue
}
c := &Cookie{
Name: name,
Value: value,
Raw: line,
}
for i := 1; i < len(parts); i++ {
parts[i] = strings.TrimSpace(parts[i])
if len(parts[i]) == 0 {
continue
}
attr, val := parts[i], ""
if j := strings.Index(attr, "="); j >= 0 {
attr, val = attr[:j], attr[j+1:]
}
lowerAttr := strings.ToLower(attr)
val, success = parseCookieValue(val, false)
if !success {
c.Unparsed = append(c.Unparsed, parts[i])
continue
}
switch lowerAttr {
case "secure":
c.Secure = true
continue
case "httponly":
c.HttpOnly = true
continue
case "domain":
c.Domain = val
continue
case "max-age":
secs, err := strconv.Atoi(val)
if err != nil || secs != 0 && val[0] == '0' {
break
}
if secs <= 0 {
c.MaxAge = -1
} else {
c.MaxAge = secs
}
continue
case "expires":
c.RawExpires = val
exptime, err := time.Parse(time.RFC1123, val)
if err != nil {
exptime, err = time.Parse("Mon, 02-Jan-2006 15:04:05 MST", val)
if err != nil {
c.Expires = time.Time{}
break
}
}
c.Expires = exptime.UTC()
continue
case "path":
c.Path = val
continue
}
c.Unparsed = append(c.Unparsed, parts[i])
}
cookies = append(cookies, c)
}
return cookies
}
// SetCookie adds a Set-Cookie header to the provided ResponseWriter's headers.
// The provided cookie must have a valid Name. Invalid cookies may be
// silently dropped.
func SetCookie(w ResponseWriter, cookie *Cookie) {
if v := cookie.String(); v != "" {
w.Header().Add("Set-Cookie", v)
}
}
// String returns the serialization of the cookie for use in a Cookie
// header (if only Name and Value are set) or a Set-Cookie response
// header (if other fields are set).
// If c is nil or c.Name is invalid, the empty string is returned.
func (c *Cookie) String() string {
if c == nil || !isCookieNameValid(c.Name) {
return ""
}
var b bytes.Buffer
fmt.Fprintf(&b, "%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value))
if len(c.Path) > 0 {
fmt.Fprintf(&b, "; Path=%s", sanitizeCookiePath(c.Path))
}
if len(c.Domain) > 0 {
if validCookieDomain(c.Domain) {
d := c.Domain
if d[0] == '.' {
d = d[1:]
}
fmt.Fprintf(&b, "; Domain=%s", d)
} else {
log.Printf("net/http: invalid Cookie.Domain %q; dropping domain attribute",
c.Domain)
}
}
if c.Expires.Unix() > 0 {
fmt.Fprintf(&b, "; Expires=%s", c.Expires.UTC().Format(TimeFormat))
}
if c.MaxAge > 0 {
fmt.Fprintf(&b, "; Max-Age=%d", c.MaxAge)
} else if c.MaxAge < 0 {
fmt.Fprintf(&b, "; Max-Age=0")
}
if c.HttpOnly {
fmt.Fprintf(&b, "; HttpOnly")
}
if c.Secure {
fmt.Fprintf(&b, "; Secure")
}
return b.String()
}
// readCookies parses all "Cookie" values from the header h and
// returns the successfully parsed Cookies.
//
// if filter isn't empty, only cookies of that name are returned
func readCookies(h Header, filter string) []*Cookie {
cookies := []*Cookie{}
lines, ok := h["Cookie"]
if !ok {
return cookies
}
for _, line := range lines {
parts := strings.Split(strings.TrimSpace(line), ";")
if len(parts) == 1 && parts[0] == "" {
continue
}
parsedPairs := 0
for i := 0; i < len(parts); i++ {
parts[i] = strings.TrimSpace(parts[i])
if len(parts[i]) == 0 {
continue
}
name, val := parts[i], ""
if j := strings.Index(name, "="); j >= 0 {
name, val = name[:j], name[j+1:]
}
if !isCookieNameValid(name) {
continue
}
if filter != "" && filter != name {
continue
}
val, success := parseCookieValue(val, true)
if !success {
continue
}
cookies = append(cookies, &Cookie{Name: name, Value: val})
parsedPairs++
}
}
return cookies
}
// validCookieDomain returns wheter v is a valid cookie domain-value.
func validCookieDomain(v string) bool {
if isCookieDomainName(v) {
return true
}
if net.ParseIP(v) != nil && !strings.Contains(v, ":") {
return true
}
return false
}
// isCookieDomainName returns whether s is a valid domain name or a valid
// domain name with a leading dot '.'. It is almost a direct copy of
// package net's isDomainName.
func isCookieDomainName(s string) bool {
if len(s) == 0 {
return false
}
if len(s) > 255 {
return false
}
if s[0] == '.' {
s = s[1:]
}
last := byte('.')
ok := false
partlen := 0
for i := 0; i < len(s); i++ {
c := s[i]
switch {
default:
return false
case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z':
ok = true
partlen++
case '0' <= c && c <= '9':
partlen++
case c == '-':
if last == '.' {
return false
}
partlen++
case c == '.':
if last == '.' || last == '-' {
return false
}
if partlen > 63 || partlen == 0 {
return false
}
partlen = 0
}
last = c
}
if last == '-' || partlen > 63 {
return false
}
return ok
}
var cookieNameSanitizer = strings.NewReplacer("\n", "-", "\r", "-")
func sanitizeCookieName(n string) string {
return cookieNameSanitizer.Replace(n)
}
// http://tools.ietf.org/html/rfc6265#section-4.1.1
// cookie-value = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )
// cookie-octet = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
// ; US-ASCII characters excluding CTLs,
// ; whitespace DQUOTE, comma, semicolon,
// ; and backslash
// We loosen this as spaces and commas are common in cookie values
// but we produce a quoted cookie-value in when value starts or ends
// with a comma or space.
// See https://golang.org/issue/7243 for the discussion.
func sanitizeCookieValue(v string) string {
v = sanitizeOrWarn("Cookie.Value", validCookieValueByte, v)
if len(v) == 0 {
return v
}
if v[0] == ' ' || v[0] == ',' || v[len(v)-1] == ' ' || v[len(v)-1] == ',' {
return ` + "`" + `"` + "`" + ` + v + ` + "`" + `"` + "`" + `
}
return v
}
func validCookieValueByte(b byte) bool {
return 0x20 <= b && b < 0x7f && b != '"' && b != ';' && b != '\\'
}
// path-av = "Path=" path-value
// path-value = <any CHAR except CTLs or ";">
func sanitizeCookiePath(v string) string {
return sanitizeOrWarn("Cookie.Path", validCookiePathByte, v)
}
func validCookiePathByte(b byte) bool {
return 0x20 <= b && b < 0x7f && b != ';'
}
func sanitizeOrWarn(fieldName string, valid func(byte) bool, v string) string {
ok := true
for i := 0; i < len(v); i++ {
if valid(v[i]) {
continue
}
log.Printf("net/http: invalid byte %q in %s; dropping invalid bytes", v[i], fieldName)
ok = false
break
}
if ok {
return v
}
buf := make([]byte, 0, len(v))
for i := 0; i < len(v); i++ {
if b := v[i]; valid(b) {
buf = append(buf, b)
}
}
return string(buf)
}
func parseCookieValue(raw string, allowDoubleQuote bool) (string, bool) {
if allowDoubleQuote && len(raw) > 1 && raw[0] == '"' && raw[len(raw)-1] == '"' {
raw = raw[1 : len(raw)-1]
}
for i := 0; i < len(raw); i++ {
if !validCookieValueByte(raw[i]) {
return "", false
}
}
return raw, true
}
func isCookieNameValid(raw string) bool {
if raw == "" {
return false
}
return strings.IndexFunc(raw, isNotToken) < 0
}
// fileTransport implements RoundTripper for the 'file' protocol.
type fileTransport struct {
fh fileHandler
}
// NewFileTransport returns a new RoundTripper, serving the provided
// FileSystem. The returned RoundTripper ignores the URL host in its
// incoming requests, as well as most other properties of the
// request.
//
// The typical use case for NewFileTransport is to register the "file"
// protocol with a Transport, as in:
//
// t := &http.Transport{}
// t.RegisterProtocol("file", http.NewFileTransport(http.Dir("/")))
// c := &http.Client{Transport: t}
// res, err := c.Get("file:///etc/passwd")
// ...
func NewFileTransport(fs FileSystem) RoundTripper {
return fileTransport{fileHandler{fs}}
}
func (t fileTransport) RoundTrip(req *Request) (resp *Response, err error) {
rw, resc := newPopulateResponseWriter()
go func() {
t.fh.ServeHTTP(rw, req)
rw.finish()
}()
return <-resc, nil
}
func newPopulateResponseWriter() (*populateResponse, <-chan *Response) {
pr, pw := io.Pipe()
rw := &populateResponse{
ch: make(chan *Response),
pw: pw,
res: &Response{
Proto: "HTTP/1.0",
ProtoMajor: 1,
Header: make(Header),
Close: true,
Body: pr,
},
}
return rw, rw.ch
}
// populateResponse is a ResponseWriter that populates the *Response
// in res, and writes its body to a pipe connected to the response
// body. Once writes begin or finish() is called, the response is sent
// on ch.
type populateResponse struct {
res *Response
ch chan *Response
wroteHeader bool
hasContent bool
sentResponse bool
pw *io.PipeWriter
}
func (pr *populateResponse) finish() {
if !pr.wroteHeader {
pr.WriteHeader(500)
}
if !pr.sentResponse {
pr.sendResponse()
}
pr.pw.Close()
}
func (pr *populateResponse) sendResponse() {
if pr.sentResponse {
return
}
pr.sentResponse = true
if pr.hasContent {
pr.res.ContentLength = -1
}
pr.ch <- pr.res
}
func (pr *populateResponse) Header() Header {
return pr.res.Header
}
func (pr *populateResponse) WriteHeader(code int) {
if pr.wroteHeader {
return
}
pr.wroteHeader = true
pr.res.StatusCode = code
pr.res.Status = fmt.Sprintf("%d %s", code, StatusText(code))
}
func (pr *populateResponse) Write(p []byte) (n int, err error) {
if !pr.wroteHeader {
pr.WriteHeader(StatusOK)
}
pr.hasContent = true
if !pr.sentResponse {
pr.sendResponse()
}
return pr.pw.Write(p)
}
// A Dir implements FileSystem using the native file system restricted to a
// specific directory tree.
//
// While the FileSystem.Open method takes '/'-separated paths, a Dir's string
// value is a filename on the native file system, not a URL, so it is separated
// by filepath.Separator, which isn't necessarily '/'.
//
// An empty Dir is treated as ".".
type Dir string
func (d Dir) Open(name string) (File, error) {
if filepath.Separator != '/' && strings.IndexRune(name, filepath.Separator) >= 0 ||
strings.Contains(name, "\x00") {
return nil, errors.New("http: invalid character in file path")
}
dir := string(d)
if dir == "" {
dir = "."
}
f, err := os.Open(filepath.Join(dir, filepath.FromSlash(path.Clean("/"+name))))
if err != nil {
return nil, err
}
return f, nil
}
// A FileSystem implements access to a collection of named files.
// The elements in a file path are separated by slash ('/', U+002F)
// characters, regardless of host operating system convention.
type FileSystem interface {
Open(name string) (File, error)
}
// A File is returned by a FileSystem's Open method and can be
// served by the FileServer implementation.
//
// The methods should behave the same as those on an *os.File.
type File interface {
io.Closer
io.Reader
Readdir(count int) ([]os.FileInfo, error)
Seek(offset int64, whence int) (int64, error)
Stat() (os.FileInfo, error)
}
func dirList(w ResponseWriter, f File) {
w.Header().Set("Content-Type", "text/html; charset=utf-8")
fmt.Fprintf(w, "<pre>\n")
for {
dirs, err := f.Readdir(100)
if err != nil || len(dirs) == 0 {
break
}
for _, d := range dirs {
name := d.Name()
if d.IsDir() {
name += "/"
}
url := url.URL{Path: name}
fmt.Fprintf(w, "<a href=\"%s\">%s</a>\n", url.String(), htmlReplacer.Replace(name))
}
}
fmt.Fprintf(w, "</pre>\n")
}
// ServeContent replies to the request using the content in the
// provided ReadSeeker. The main benefit of ServeContent over io.Copy
// is that it handles Range requests properly, sets the MIME type, and
// handles If-Modified-Since requests.
//
// If the response's Content-Type header is not set, ServeContent
// first tries to deduce the type from name's file extension and,
// if that fails, falls back to reading the first block of the content
// and passing it to DetectContentType.
// The name is otherwise unused; in particular it can be empty and is
// never sent in the response.
//
// If modtime is not the zero time or Unix epoch, ServeContent
// includes it in a Last-Modified header in the response. If the
// request includes an If-Modified-Since header, ServeContent uses
// modtime to decide whether the content needs to be sent at all.
//
// The content's Seek method must work: ServeContent uses
// a seek to the end of the content to determine its size.
//
// If the caller has set w's ETag header, ServeContent uses it to
// handle requests using If-Range and If-None-Match.
//
// Note that *os.File implements the io.ReadSeeker interface.
func ServeContent(w ResponseWriter, req *Request, name string, modtime time.Time, content io.ReadSeeker) {
sizeFunc := func() (int64, error) {
size, err := content.Seek(0, os.SEEK_END)
if err != nil {
return 0, errSeeker
}
_, err = content.Seek(0, os.SEEK_SET)
if err != nil {
return 0, errSeeker
}
return size, nil
}
serveContent(w, req, name, modtime, sizeFunc, content)
}
// errSeeker is returned by ServeContent's sizeFunc when the content
// doesn't seek properly. The underlying Seeker's error text isn't
// included in the sizeFunc reply so it's not sent over HTTP to end
// users.
var errSeeker = errors.New("seeker can't seek")
// if name is empty, filename is unknown. (used for mime type, before sniffing)
// if modtime.IsZero(), modtime is unknown.
// content must be seeked to the beginning of the file.
// The sizeFunc is called at most once. Its error, if any, is sent in the HTTP response.
func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time, sizeFunc func() (int64, error), content io.ReadSeeker) {
if checkLastModified(w, r, modtime) {
return
}
rangeReq, done := checkETag(w, r, modtime)
if done {
return
}
code := StatusOK
ctypes, haveType := w.Header()["Content-Type"]
var ctype string
if !haveType {
ctype = mime.TypeByExtension(filepath.Ext(name))
if ctype == "" {
// read a chunk to decide between utf-8 text and binary
var buf [sniffLen]byte
n, _ := io.ReadFull(content, buf[:])
ctype = DetectContentType(buf[:n])
_, err := content.Seek(0, os.SEEK_SET)
if err != nil {
Error(w, "seeker can't seek", StatusInternalServerError)
return
}
}
w.Header().Set("Content-Type", ctype)
} else if len(ctypes) > 0 {
ctype = ctypes[0]
}
size, err := sizeFunc()
if err != nil {
Error(w, err.Error(), StatusInternalServerError)
return
}
sendSize := size
var sendContent io.Reader = content
if size >= 0 {
ranges, err := parseRange(rangeReq, size)
if err != nil {
Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
return
}
if sumRangesSize(ranges) > size {
ranges = nil
}
switch {
case len(ranges) == 1:
ra := ranges[0]
if _, err := content.Seek(ra.start, os.SEEK_SET); err != nil {
Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
return
}
sendSize = ra.length
code = StatusPartialContent
w.Header().Set("Content-Range", ra.contentRange(size))
case len(ranges) > 1:
sendSize = rangesMIMESize(ranges, ctype, size)
code = StatusPartialContent
pr, pw := io.Pipe()
mw := multipart.NewWriter(pw)
w.Header().Set("Content-Type", "multipart/byteranges; boundary="+mw.Boundary())
sendContent = pr
defer pr.Close()
go func() {
for _, ra := range ranges {
part, err := mw.CreatePart(ra.mimeHeader(ctype, size))
if err != nil {
pw.CloseWithError(err)
return
}
if _, err := content.Seek(ra.start, os.SEEK_SET); err != nil {
pw.CloseWithError(err)
return
}
if _, err := io.CopyN(part, content, ra.length); err != nil {
pw.CloseWithError(err)
return
}
}
mw.Close()
pw.Close()
}()
}
w.Header().Set("Accept-Ranges", "bytes")
if w.Header().Get("Content-Encoding") == "" {
w.Header().Set("Content-Length", strconv.FormatInt(sendSize, 10))
}
}
w.WriteHeader(code)
if r.Method != "HEAD" {
io.CopyN(w, sendContent, sendSize)
}
}
var unixEpochTime = time.Unix(0, 0)
// modtime is the modification time of the resource to be served, or IsZero().
// return value is whether this request is now complete.
func checkLastModified(w ResponseWriter, r *Request, modtime time.Time) bool {
if modtime.IsZero() || modtime.Equal(unixEpochTime) {
return false
}
if t, err := time.Parse(TimeFormat, r.Header.Get("If-Modified-Since")); err == nil && modtime.Before(t.Add(1*time.Second)) {
h := w.Header()
delete(h, "Content-Type")
delete(h, "Content-Length")
w.WriteHeader(StatusNotModified)
return true
}
w.Header().Set("Last-Modified", modtime.UTC().Format(TimeFormat))
return false
}
// checkETag implements If-None-Match and If-Range checks.
//
// The ETag or modtime must have been previously set in the
// ResponseWriter's headers. The modtime is only compared at second
// granularity and may be the zero value to mean unknown.
//
// The return value is the effective request "Range" header to use and
// whether this request is now considered done.
func checkETag(w ResponseWriter, r *Request, modtime time.Time) (rangeReq string, done bool) {
etag := w.Header().get("Etag")
rangeReq = r.Header.get("Range")
if ir := r.Header.get("If-Range"); ir != "" && ir != etag {
timeMatches := false
if !modtime.IsZero() {
if t, err := ParseTime(ir); err == nil && t.Unix() == modtime.Unix() {
timeMatches = true
}
}
if !timeMatches {
rangeReq = ""
}
}
if inm := r.Header.get("If-None-Match"); inm != "" {
if etag == "" {
return rangeReq, false
}
if r.Method != "GET" && r.Method != "HEAD" {
return rangeReq, false
}
if inm == etag || inm == "*" {
h := w.Header()
delete(h, "Content-Type")
delete(h, "Content-Length")
w.WriteHeader(StatusNotModified)
return "", true
}
}
return rangeReq, false
}
// name is '/'-separated, not filepath.Separator.
func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirect bool) {
const indexPage = "/index.html"
if strings.HasSuffix(r.URL.Path, indexPage) {
localRedirect(w, r, "./")
return
}
f, err := fs.Open(name)
if err != nil {
msg, code := toHTTPError(err)
Error(w, msg, code)
return
}
defer f.Close()
d, err1 := f.Stat()
if err1 != nil {
msg, code := toHTTPError(err)
Error(w, msg, code)
return
}
if redirect {
url := r.URL.Path
if d.IsDir() {
if url[len(url)-1] != '/' {
localRedirect(w, r, path.Base(url)+"/")
return
}
} else {
if url[len(url)-1] == '/' {
localRedirect(w, r, "../"+path.Base(url))
return
}
}
}
if d.IsDir() {
index := strings.TrimSuffix(name, "/") + indexPage
ff, err := fs.Open(index)
if err == nil {
defer ff.Close()
dd, err := ff.Stat()
if err == nil {
name = index
d = dd
f = ff
}
}
}
if d.IsDir() {
if checkLastModified(w, r, d.ModTime()) {
return
}
dirList(w, f)
return
}
sizeFunc := func() (int64, error) { return d.Size(), nil }
serveContent(w, r, d.Name(), d.ModTime(), sizeFunc, f)
}
// toHTTPError returns a non-specific HTTP error message and status code
// for a given non-nil error value. It's important that toHTTPError does not
// actually return err.Error(), since msg and httpStatus are returned to users,
// and historically Go's ServeContent always returned just "404 Not Found" for
// all errors. We don't want to start leaking information in error messages.
func toHTTPError(err error) (msg string, httpStatus int) {
if os.IsNotExist(err) {
return "404 page not found", StatusNotFound
}
if os.IsPermission(err) {
return "403 Forbidden", StatusForbidden
}
return "500 Internal Server Error", StatusInternalServerError
}
// localRedirect gives a Moved Permanently response.
// It does not convert relative paths to absolute paths like Redirect does.
func localRedirect(w ResponseWriter, r *Request, newPath string) {
if q := r.URL.RawQuery; q != "" {
newPath += "?" + q
}
w.Header().Set("Location", newPath)
w.WriteHeader(StatusMovedPermanently)
}
// ServeFile replies to the request with the contents of the named
// file or directory.
//
// As a special case, ServeFile redirects any request where r.URL.Path
// ends in "/index.html" to the same path, without the final
// "index.html". To avoid such redirects either modify the path or
// use ServeContent.
func ServeFile(w ResponseWriter, r *Request, name string) {
dir, file := filepath.Split(name)
serveFile(w, r, Dir(dir), file, false)
}
type fileHandler struct {
root FileSystem
}
// FileServer returns a handler that serves HTTP requests
// with the contents of the file system rooted at root.
//
// To use the operating system's file system implementation,
// use http.Dir:
//
// http.Handle("/", http.FileServer(http.Dir("/tmp")))
//
// As a special case, the returned file server redirects any request
// ending in "/index.html" to the same path, without the final
// "index.html".
func FileServer(root FileSystem) Handler {
return &fileHandler{root}
}
func (f *fileHandler) ServeHTTP(w ResponseWriter, r *Request) {
upath := r.URL.Path
if !strings.HasPrefix(upath, "/") {
upath = "/" + upath
r.URL.Path = upath
}
serveFile(w, r, f.root, path.Clean(upath), true)
}
// httpRange specifies the byte range to be sent to the client.
type httpRange struct {
start, length int64
}
func (r httpRange) contentRange(size int64) string {
return fmt.Sprintf("bytes %d-%d/%d", r.start, r.start+r.length-1, size)
}
func (r httpRange) mimeHeader(contentType string, size int64) textproto.MIMEHeader {
return textproto.MIMEHeader{
"Content-Range": {r.contentRange(size)},
"Content-Type": {contentType},
}
}
// parseRange parses a Range header string as per RFC 2616.
func parseRange(s string, size int64) ([]httpRange, error) {
if s == "" {
return nil, nil
}
const b = "bytes="
if !strings.HasPrefix(s, b) {
return nil, errors.New("invalid range")
}
var ranges []httpRange
for _, ra := range strings.Split(s[len(b):], ",") {
ra = strings.TrimSpace(ra)
if ra == "" {
continue
}
i := strings.Index(ra, "-")
if i < 0 {
return nil, errors.New("invalid range")
}
start, end := strings.TrimSpace(ra[:i]), strings.TrimSpace(ra[i+1:])
var r httpRange
if start == "" {
i, err := strconv.ParseInt(end, 10, 64)
if err != nil {
return nil, errors.New("invalid range")
}
if i > size {
i = size
}
r.start = size - i
r.length = size - r.start
} else {
i, err := strconv.ParseInt(start, 10, 64)
if err != nil || i >= size || i < 0 {
return nil, errors.New("invalid range")
}
r.start = i
if end == "" {
r.length = size - r.start
} else {
i, err := strconv.ParseInt(end, 10, 64)
if err != nil || r.start > i {
return nil, errors.New("invalid range")
}
if i >= size {
i = size - 1
}
r.length = i - r.start + 1
}
}
ranges = append(ranges, r)
}
return ranges, nil
}
// countingWriter counts how many bytes have been written to it.
type countingWriter int64
func (w *countingWriter) Write(p []byte) (n int, err error) {
*w += countingWriter(len(p))
return len(p), nil
}
// rangesMIMESize returns the number of bytes it takes to encode the
// provided ranges as a multipart response.
func rangesMIMESize(ranges []httpRange, contentType string, contentSize int64) (encSize int64) {
var w countingWriter
mw := multipart.NewWriter(&w)
for _, ra := range ranges {
mw.CreatePart(ra.mimeHeader(contentType, contentSize))
encSize += ra.length
}
mw.Close()
encSize += int64(w)
return
}
func sumRangesSize(ranges []httpRange) (size int64) {
for _, ra := range ranges {
size += ra.length
}
return
}
var raceEnabled = false // set by race.go
// A Header represents the key-value pairs in an HTTP header.
type Header map[string][]string
// Add adds the key, value pair to the header.
// It appends to any existing values associated with key.
func (h Header) Add(key, value string) {
textproto.MIMEHeader(h).Add(key, value)
}
// Set sets the header entries associated with key to
// the single element value. It replaces any existing
// values associated with key.
func (h Header) Set(key, value string) {
textproto.MIMEHeader(h).Set(key, value)
}
// Get gets the first value associated with the given key.
// If there are no values associated with the key, Get returns "".
// To access multiple values of a key, access the map directly
// with CanonicalHeaderKey.
func (h Header) Get(key string) string {
return textproto.MIMEHeader(h).Get(key)
}
// get is like Get, but key must already be in CanonicalHeaderKey form.
func (h Header) get(key string) string {
if v := h[key]; len(v) > 0 {
return v[0]
}
return ""
}
// Del deletes the values associated with key.
func (h Header) Del(key string) {
textproto.MIMEHeader(h).Del(key)
}
// Write writes a header in wire format.
func (h Header) Write(w io.Writer) error {
return h.WriteSubset(w, nil)
}
func (h Header) clone() Header {
h2 := make(Header, len(h))
for k, vv := range h {
vv2 := make([]string, len(vv))
copy(vv2, vv)
h2[k] = vv2
}
return h2
}
var timeFormats = []string{
TimeFormat,
time.RFC850,
time.ANSIC,
}
// ParseTime parses a time header (such as the Date: header),
// trying each of the three formats allowed by HTTP/1.1:
// TimeFormat, time.RFC850, and time.ANSIC.
func ParseTime(text string) (t time.Time, err error) {
for _, layout := range timeFormats {
t, err = time.Parse(layout, text)
if err == nil {
return
}
}
return
}
var headerNewlineToSpace = strings.NewReplacer("\n", " ", "\r", " ")
type writeStringer interface {
WriteString(string) (int, error)
}
// stringWriter implements WriteString on a Writer.
type stringWriter struct {
w io.Writer
}
func (w stringWriter) WriteString(s string) (n int, err error) {
return w.w.Write([]byte(s))
}
type keyValues struct {
key string
values []string
}
// A headerSorter implements sort.Interface by sorting a []keyValues
// by key. It's used as a pointer, so it can fit in a sort.Interface
// interface value without allocation.
type headerSorter struct {
kvs []keyValues
}
func (s *headerSorter) Len() int { return len(s.kvs) }
func (s *headerSorter) Swap(i, j int) { s.kvs[i], s.kvs[j] = s.kvs[j], s.kvs[i] }
func (s *headerSorter) Less(i, j int) bool { return s.kvs[i].key < s.kvs[j].key }
var headerSorterPool = sync.Pool{
New: func() interface{} { return new(headerSorter) },
}
// sortedKeyValues returns h's keys sorted in the returned kvs
// slice. The headerSorter used to sort is also returned, for possible
// return to headerSorterCache.
func (h Header) sortedKeyValues(exclude map[string]bool) (kvs []keyValues, hs *headerSorter) {
hs = headerSorterPool.Get().(*headerSorter)
if cap(hs.kvs) < len(h) {
hs.kvs = make([]keyValues, 0, len(h))
}
kvs = hs.kvs[:0]
for k, vv := range h {
if !exclude[k] {
kvs = append(kvs, keyValues{k, vv})
}
}
hs.kvs = kvs
sort.Sort(hs)
return kvs, hs
}
// WriteSubset writes a header in wire format.
// If exclude is not nil, keys where exclude[key] == true are not written.
func (h Header) WriteSubset(w io.Writer, exclude map[string]bool) error {
ws, ok := w.(writeStringer)
if !ok {
ws = stringWriter{w}
}
kvs, sorter := h.sortedKeyValues(exclude)
for _, kv := range kvs {
for _, v := range kv.values {
v = headerNewlineToSpace.Replace(v)
v = textproto.TrimString(v)
for _, s := range []string{kv.key, ": ", v, "\r\n"} {
if _, err := ws.WriteString(s); err != nil {
return err
}
}
}
}
headerSorterPool.Put(sorter)
return nil
}
// CanonicalHeaderKey returns the canonical format of the
// header key s. The canonicalization converts the first
// letter and any letter following a hyphen to upper case;
// the rest are converted to lowercase. For example, the
// canonical key for "accept-encoding" is "Accept-Encoding".
// If s contains a space or invalid header field bytes, it is
// returned without modifications.
func CanonicalHeaderKey(s string) string { return textproto.CanonicalMIMEHeaderKey(s) }
// hasToken reports whether token appears with v, ASCII
// case-insensitive, with space or comma boundaries.
// token must be all lowercase.
// v may contain mixed cased.
func hasToken(v, token string) bool {
if len(token) > len(v) || token == "" {
return false
}
if v == token {
return true
}
for sp := 0; sp <= len(v)-len(token); sp++ {
if b := v[sp]; b != token[0] && b|0x20 != token[0] {
continue
}
if sp > 0 && !isTokenBoundary(v[sp-1]) {
continue
}
if endPos := sp + len(token); endPos != len(v) && !isTokenBoundary(v[endPos]) {
continue
}
if strings.EqualFold(v[sp:sp+len(token)], token) {
return true
}
}
return false
}
func isTokenBoundary(b byte) bool {
return b == ' ' || b == ',' || b == '\t'
}
// A CookieJar manages storage and use of cookies in HTTP requests.
//
// Implementations of CookieJar must be safe for concurrent use by multiple
// goroutines.
//
// The net/http/cookiejar package provides a CookieJar implementation.
type CookieJar interface {
// SetCookies handles the receipt of the cookies in a reply for the
// given URL. It may or may not choose to save the cookies, depending
// on the jar's policy and implementation.
SetCookies(u *url.URL, cookies []*Cookie)
// Cookies returns the cookies to send in a request for the given URL.
// It is up to the implementation to honor the standard cookie use
// restrictions such as in RFC 6265.
Cookies(u *url.URL) []*Cookie
}
var isTokenTable = [127]bool{
'!': true,
'#': true,
'$': true,
'%': true,
'&': true,
'\'': true,
'*': true,
'+': true,
'-': true,
'.': true,
'0': true,
'1': true,
'2': true,
'3': true,
'4': true,
'5': true,
'6': true,
'7': true,
'8': true,
'9': true,
'A': true,
'B': true,
'C': true,
'D': true,
'E': true,
'F': true,
'G': true,
'H': true,
'I': true,
'J': true,
'K': true,
'L': true,
'M': true,
'N': true,
'O': true,
'P': true,
'Q': true,
'R': true,
'S': true,
'T': true,
'U': true,
'W': true,
'V': true,
'X': true,
'Y': true,
'Z': true,
'^': true,
'_': true,
'` + "`" + `': true,
'a': true,
'b': true,
'c': true,
'd': true,
'e': true,
'f': true,
'g': true,
'h': true,
'i': true,
'j': true,
'k': true,
'l': true,
'm': true,
'n': true,
'o': true,
'p': true,
'q': true,
'r': true,
's': true,
't': true,
'u': true,
'v': true,
'w': true,
'x': true,
'y': true,
'z': true,
'|': true,
'~': true,
}
func isToken(r rune) bool {
i := int(r)
return i < len(isTokenTable) && isTokenTable[i]
}
func isNotToken(r rune) bool {
return !isToken(r)
}
// headerValuesContainsToken reports whether any string in values
// contains the provided token, ASCII case-insensitively.
func headerValuesContainsToken(values []string, token string) bool {
for _, v := range values {
if headerValueContainsToken(v, token) {
return true
}
}
return false
}
// isOWS reports whether b is an optional whitespace byte, as defined
// by RFC 7230 section 3.2.3.
func isOWS(b byte) bool { return b == ' ' || b == '\t' }
// trimOWS returns x with all optional whitespace removes from the
// beginning and end.
func trimOWS(x string) string {
for len(x) > 0 && isOWS(x[0]) {
x = x[1:]
}
for len(x) > 0 && isOWS(x[len(x)-1]) {
x = x[:len(x)-1]
}
return x
}
// headerValueContainsToken reports whether v (assumed to be a
// 0#element, in the ABNF extension described in RFC 7230 section 7)
// contains token amongst its comma-separated tokens, ASCII
// case-insensitively.
func headerValueContainsToken(v string, token string) bool {
v = trimOWS(v)
if comma := strings.IndexByte(v, ','); comma != -1 {
return tokenEqual(trimOWS(v[:comma]), token) || headerValueContainsToken(v[comma+1:], token)
}
return tokenEqual(v, token)
}
// lowerASCII returns the ASCII lowercase version of b.
func lowerASCII(b byte) byte {
if 'A' <= b && b <= 'Z' {
return b + ('a' - 'A')
}
return b
}
// tokenEqual reports whether t1 and t2 are equal, ASCII case-insensitively.
func tokenEqual(t1, t2 string) bool {
if len(t1) != len(t2) {
return false
}
for i, b := range t1 {
if b >= utf8.RuneSelf {
return false
}
if lowerASCII(byte(b)) != lowerASCII(t2[i]) {
return false
}
}
return true
}
const (
defaultMaxMemory = 32 << 20 // 32 MB
)
// ErrMissingFile is returned by FormFile when the provided file field name
// is either not present in the request or not a file field.
var ErrMissingFile = errors.New("http: no such file")
// HTTP request parsing errors.
type ProtocolError struct {
ErrorString string
}
func (err *ProtocolError) Error() string { return err.ErrorString }
var (
ErrHeaderTooLong = &ProtocolError{"header too long"}
ErrShortBody = &ProtocolError{"entity body too short"}
ErrNotSupported = &ProtocolError{"feature not supported"}
ErrUnexpectedTrailer = &ProtocolError{"trailer header without chunked transfer encoding"}
ErrMissingContentLength = &ProtocolError{"missing ContentLength in HEAD response"}
ErrNotMultipart = &ProtocolError{"request Content-Type isn't multipart/form-data"}
ErrMissingBoundary = &ProtocolError{"no multipart boundary param in Content-Type"}
)
type badStringError struct {
what string
str string
}
func (e *badStringError) Error() string { return fmt.Sprintf("%s %q", e.what, e.str) }
// Headers that Request.Write handles itself and should be skipped.
var reqWriteExcludeHeader = map[string]bool{
"Host": true,
"User-Agent": true,
"Content-Length": true,
"Transfer-Encoding": true,
"Trailer": true,
}
// A Request represents an HTTP request received by a server
// or to be sent by a client.
//
// The field semantics differ slightly between client and server
// usage. In addition to the notes on the fields below, see the
// documentation for Request.Write and RoundTripper.
type Request struct {
// Method specifies the HTTP method (GET, POST, PUT, etc.).
// For client requests an empty string means GET.
Method string
// URL specifies either the URI being requested (for server
// requests) or the URL to access (for client requests).
//
// For server requests the URL is parsed from the URI
// supplied on the Request-Line as stored in RequestURI. For
// most requests, fields other than Path and RawQuery will be
// empty. (See RFC 2616, Section 5.1.2)
//
// For client requests, the URL's Host specifies the server to
// connect to, while the Request's Host field optionally
// specifies the Host header value to send in the HTTP
// request.
URL *url.URL
// The protocol version for incoming requests.
// Client requests always use HTTP/1.1.
Proto string // "HTTP/1.0"
ProtoMajor int // 1
ProtoMinor int // 0
// A header maps request lines to their values.
// If the header says
//
// accept-encoding: gzip, deflate
// Accept-Language: en-us
// Connection: keep-alive
//
// then
//
// Header = map[string][]string{
// "Accept-Encoding": {"gzip, deflate"},
// "Accept-Language": {"en-us"},
// "Connection": {"keep-alive"},
// }
//
// HTTP defines that header names are case-insensitive.
// The request parser implements this by canonicalizing the
// name, making the first character and any characters
// following a hyphen uppercase and the rest lowercase.
//
// For client requests certain headers are automatically
// added and may override values in Header.
//
// See the documentation for the Request.Write method.
Header Header
// Body is the request's body.
//
// For client requests a nil body means the request has no
// body, such as a GET request. The HTTP Client's Transport
// is responsible for calling the Close method.
//
// For server requests the Request Body is always non-nil
// but will return EOF immediately when no body is present.
// The Server will close the request body. The ServeHTTP
// Handler does not need to.
Body io.ReadCloser
// ContentLength records the length of the associated content.
// The value -1 indicates that the length is unknown.
// Values >= 0 indicate that the given number of bytes may
// be read from Body.
// For client requests, a value of 0 means unknown if Body is not nil.
ContentLength int64
// TransferEncoding lists the transfer encodings from outermost to
// innermost. An empty list denotes the "identity" encoding.
// TransferEncoding can usually be ignored; chunked encoding is
// automatically added and removed as necessary when sending and
// receiving requests.
TransferEncoding []string
// Close indicates whether to close the connection after
// replying to this request (for servers) or after sending
// the request (for clients).
Close bool
// For server requests Host specifies the host on which the
// URL is sought. Per RFC 2616, this is either the value of
// the "Host" header or the host name given in the URL itself.
// It may be of the form "host:port".
//
// For client requests Host optionally overrides the Host
// header to send. If empty, the Request.Write method uses
// the value of URL.Host.
Host string
// Form contains the parsed form data, including both the URL
// field's query parameters and the POST or PUT form data.
// This field is only available after ParseForm is called.
// The HTTP client ignores Form and uses Body instead.
Form url.Values
// PostForm contains the parsed form data from POST, PATCH,
// or PUT body parameters.
//
// This field is only available after ParseForm is called.
// The HTTP client ignores PostForm and uses Body instead.
PostForm url.Values
// MultipartForm is the parsed multipart form, including file uploads.
// This field is only available after ParseMultipartForm is called.
// The HTTP client ignores MultipartForm and uses Body instead.
MultipartForm *multipart.Form
// Trailer specifies additional headers that are sent after the request
// body.
//
// For server requests the Trailer map initially contains only the
// trailer keys, with nil values. (The client declares which trailers it
// will later send.) While the handler is reading from Body, it must
// not reference Trailer. After reading from Body returns EOF, Trailer
// can be read again and will contain non-nil values, if they were sent
// by the client.
//
// For client requests Trailer must be initialized to a map containing
// the trailer keys to later send. The values may be nil or their final
// values. The ContentLength must be 0 or -1, to send a chunked request.
// After the HTTP request is sent the map values can be updated while
// the request body is read. Once the body returns EOF, the caller must
// not mutate Trailer.
//
// Few HTTP clients, servers, or proxies support HTTP trailers.
Trailer Header
// RemoteAddr allows HTTP servers and other software to record
// the network address that sent the request, usually for
// logging. This field is not filled in by ReadRequest and
// has no defined format. The HTTP server in this package
// sets RemoteAddr to an "IP:port" address before invoking a
// handler.
// This field is ignored by the HTTP client.
RemoteAddr string
// RequestURI is the unmodified Request-URI of the
// Request-Line (RFC 2616, Section 5.1) as sent by the client
// to a server. Usually the URL field should be used instead.
// It is an error to set this field in an HTTP client request.
RequestURI string
// TLS allows HTTP servers and other software to record
// information about the TLS connection on which the request
// was received. This field is not filled in by ReadRequest.
// The HTTP server in this package sets the field for
// TLS-enabled connections before invoking a handler;
// otherwise it leaves the field nil.
// This field is ignored by the HTTP client.
TLS *tls.ConnectionState
// Cancel is an optional channel whose closure indicates that the client
// request should be regarded as canceled. Not all implementations of
// RoundTripper may support Cancel.
//
// For server requests, this field is not applicable.
Cancel <-chan struct{}
}
// ProtoAtLeast reports whether the HTTP protocol used
// in the request is at least major.minor.
func (r *Request) ProtoAtLeast(major, minor int) bool {
return r.ProtoMajor > major ||
r.ProtoMajor == major && r.ProtoMinor >= minor
}
// UserAgent returns the client's User-Agent, if sent in the request.
func (r *Request) UserAgent() string {
return r.Header.Get("User-Agent")
}
// Cookies parses and returns the HTTP cookies sent with the request.
func (r *Request) Cookies() []*Cookie {
return readCookies(r.Header, "")
}
// ErrNoCookie is returned by Request's Cookie method when a cookie is not found.
var ErrNoCookie = errors.New("http: named cookie not present")
// Cookie returns the named cookie provided in the request or
// ErrNoCookie if not found.
func (r *Request) Cookie(name string) (*Cookie, error) {
for _, c := range readCookies(r.Header, name) {
return c, nil
}
return nil, ErrNoCookie
}
// AddCookie adds a cookie to the request. Per RFC 6265 section 5.4,
// AddCookie does not attach more than one Cookie header field. That
// means all cookies, if any, are written into the same line,
// separated by semicolon.
func (r *Request) AddCookie(c *Cookie) {
s := fmt.Sprintf("%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value))
if c := r.Header.Get("Cookie"); c != "" {
r.Header.Set("Cookie", c+"; "+s)
} else {
r.Header.Set("Cookie", s)
}
}
// Referer returns the referring URL, if sent in the request.
//
// Referer is misspelled as in the request itself, a mistake from the
// earliest days of HTTP. This value can also be fetched from the
// Header map as Header["Referer"]; the benefit of making it available
// as a method is that the compiler can diagnose programs that use the
// alternate (correct English) spelling req.Referrer() but cannot
// diagnose programs that use Header["Referrer"].
func (r *Request) Referer() string {
return r.Header.Get("Referer")
}
// multipartByReader is a sentinel value.
// Its presence in Request.MultipartForm indicates that parsing of the request
// body has been handed off to a MultipartReader instead of ParseMultipartFrom.
var multipartByReader = &multipart.Form{
Value: make(map[string][]string),
File: make(map[string][]*multipart.FileHeader),
}
// MultipartReader returns a MIME multipart reader if this is a
// multipart/form-data POST request, else returns nil and an error.
// Use this function instead of ParseMultipartForm to
// process the request body as a stream.
func (r *Request) MultipartReader() (*multipart.Reader, error) {
if r.MultipartForm == multipartByReader {
return nil, errors.New("http: MultipartReader called twice")
}
if r.MultipartForm != nil {
return nil, errors.New("http: multipart handled by ParseMultipartForm")
}
r.MultipartForm = multipartByReader
return r.multipartReader()
}
func (r *Request) multipartReader() (*multipart.Reader, error) {
v := r.Header.Get("Content-Type")
if v == "" {
return nil, ErrNotMultipart
}
d, params, err := mime.ParseMediaType(v)
if err != nil || d != "multipart/form-data" {
return nil, ErrNotMultipart
}
boundary, ok := params["boundary"]
if !ok {
return nil, ErrMissingBoundary
}
return multipart.NewReader(r.Body, boundary), nil
}
// Return value if nonempty, def otherwise.
func valueOrDefault(value, def string) string {
if value != "" {
return value
}
return def
}
// NOTE: This is not intended to reflect the actual Go version being used.
// It was changed at the time of Go 1.1 release because the former User-Agent
// had ended up on a blacklist for some intrusion detection systems.
// See https://codereview.appspot.com/7532043.
const defaultUserAgent = "Go-http-client/1.1"
// Write writes an HTTP/1.1 request, which is the header and body, in wire format.
// This method consults the following fields of the request:
// Host
// URL
// Method (defaults to "GET")
// Header
// ContentLength
// TransferEncoding
// Body
//
// If Body is present, Content-Length is <= 0 and TransferEncoding
// hasn't been set to "identity", Write adds "Transfer-Encoding:
// chunked" to the header. Body is closed after it is sent.
func (r *Request) Write(w io.Writer) error {
return r.write(w, false, nil)
}
// WriteProxy is like Write but writes the request in the form
// expected by an HTTP proxy. In particular, WriteProxy writes the
// initial Request-URI line of the request with an absolute URI, per
// section 5.1.2 of RFC 2616, including the scheme and host.
// In either case, WriteProxy also writes a Host header, using
// either r.Host or r.URL.Host.
func (r *Request) WriteProxy(w io.Writer) error {
return r.write(w, true, nil)
}
// extraHeaders may be nil
func (req *Request) write(w io.Writer, usingProxy bool, extraHeaders Header) error {
host := cleanHost(req.Host)
if host == "" {
if req.URL == nil {
return errors.New("http: Request.Write on Request with no Host or URL set")
}
host = cleanHost(req.URL.Host)
}
host = removeZone(host)
ruri := req.URL.RequestURI()
if usingProxy && req.URL.Scheme != "" && req.URL.Opaque == "" {
ruri = req.URL.Scheme + "://" + host + ruri
} else if req.Method == "CONNECT" && req.URL.Path == "" {
ruri = host
}
// Wrap the writer in a bufio Writer if it's not already buffered.
// Don't always call NewWriter, as that forces a bytes.Buffer
// and other small bufio Writers to have a minimum 4k buffer
// size.
var bw *bufio.Writer
if _, ok := w.(io.ByteWriter); !ok {
bw = bufio.NewWriter(w)
w = bw
}
_, err := fmt.Fprintf(w, "%s %s HTTP/1.1\r\n", valueOrDefault(req.Method, "GET"), ruri)
if err != nil {
return err
}
_, err = fmt.Fprintf(w, "Host: %s\r\n", host)
if err != nil {
return err
}
userAgent := defaultUserAgent
if req.Header != nil {
if ua := req.Header["User-Agent"]; len(ua) > 0 {
userAgent = ua[0]
}
}
if userAgent != "" {
_, err = fmt.Fprintf(w, "User-Agent: %s\r\n", userAgent)
if err != nil {
return err
}
}
tw, err := newTransferWriter(req)
if err != nil {
return err
}
err = tw.WriteHeader(w)
if err != nil {
return err
}
err = req.Header.WriteSubset(w, reqWriteExcludeHeader)
if err != nil {
return err
}
if extraHeaders != nil {
err = extraHeaders.Write(w)
if err != nil {
return err
}
}
_, err = io.WriteString(w, "\r\n")
if err != nil {
return err
}
err = tw.WriteBody(w)
if err != nil {
return err
}
if bw != nil {
return bw.Flush()
}
return nil
}
// cleanHost strips anything after '/' or ' '.
// Ideally we'd clean the Host header according to the spec:
// https://tools.ietf.org/html/rfc7230#section-5.4 (Host = uri-host [ ":" port ]")
// https://tools.ietf.org/html/rfc7230#section-2.7 (uri-host -> rfc3986's host)
// https://tools.ietf.org/html/rfc3986#section-3.2.2 (definition of host)
// But practically, what we are trying to avoid is the situation in
// issue 11206, where a malformed Host header used in the proxy context
// would create a bad request. So it is enough to just truncate at the
// first offending character.
func cleanHost(in string) string {
if i := strings.IndexAny(in, " /"); i != -1 {
return in[:i]
}
return in
}
// removeZone removes IPv6 zone identifer from host.
// E.g., "[fe80::1%en0]:8080" to "[fe80::1]:8080"
func removeZone(host string) string {
if !strings.HasPrefix(host, "[") {
return host
}
i := strings.LastIndex(host, "]")
if i < 0 {
return host
}
j := strings.LastIndex(host[:i], "%")
if j < 0 {
return host
}
return host[:j] + host[i:]
}
// ParseHTTPVersion parses a HTTP version string.
// "HTTP/1.0" returns (1, 0, true).
func ParseHTTPVersion(vers string) (major, minor int, ok bool) {
const Big = 1000000 // arbitrary upper bound
switch vers {
case "HTTP/1.1":
return 1, 1, true
case "HTTP/1.0":
return 1, 0, true
}
if !strings.HasPrefix(vers, "HTTP/") {
return 0, 0, false
}
dot := strings.Index(vers, ".")
if dot < 0 {
return 0, 0, false
}
major, err := strconv.Atoi(vers[5:dot])
if err != nil || major < 0 || major > Big {
return 0, 0, false
}
minor, err = strconv.Atoi(vers[dot+1:])
if err != nil || minor < 0 || minor > Big {
return 0, 0, false
}
return major, minor, true
}
// NewRequest returns a new Request given a method, URL, and optional body.
//
// If the provided body is also an io.Closer, the returned
// Request.Body is set to body and will be closed by the Client
// methods Do, Post, and PostForm, and Transport.RoundTrip.
//
// NewRequest returns a Request suitable for use with Client.Do or
// Transport.RoundTrip.
// To create a request for use with testing a Server Handler use either
// ReadRequest or manually update the Request fields. See the Request
// type's documentation for the difference between inbound and outbound
// request fields.
func NewRequest(method, urlStr string, body io.Reader) (*Request, error) {
u, err := url.Parse(urlStr)
if err != nil {
return nil, err
}
rc, ok := body.(io.ReadCloser)
if !ok && body != nil {
rc = ioutil.NopCloser(body)
}
req := &Request{
Method: method,
URL: u,
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: make(Header),
Body: rc,
Host: u.Host,
}
if body != nil {
switch v := body.(type) {
case *bytes.Buffer:
req.ContentLength = int64(v.Len())
case *bytes.Reader:
req.ContentLength = int64(v.Len())
case *strings.Reader:
req.ContentLength = int64(v.Len())
}
}
return req, nil
}
// BasicAuth returns the username and password provided in the request's
// Authorization header, if the request uses HTTP Basic Authentication.
// See RFC 2617, Section 2.
func (r *Request) BasicAuth() (username, password string, ok bool) {
auth := r.Header.Get("Authorization")
if auth == "" {
return
}
return parseBasicAuth(auth)
}
// parseBasicAuth parses an HTTP Basic Authentication string.
// "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==" returns ("Aladdin", "open sesame", true).
func parseBasicAuth(auth string) (username, password string, ok bool) {
const prefix = "Basic "
if !strings.HasPrefix(auth, prefix) {
return
}
c, err := base64.StdEncoding.DecodeString(auth[len(prefix):])
if err != nil {
return
}
cs := string(c)
s := strings.IndexByte(cs, ':')
if s < 0 {
return
}
return cs[:s], cs[s+1:], true
}
// SetBasicAuth sets the request's Authorization header to use HTTP
// Basic Authentication with the provided username and password.
//
// With HTTP Basic Authentication the provided username and password
// are not encrypted.
func (r *Request) SetBasicAuth(username, password string) {
r.Header.Set("Authorization", "Basic "+basicAuth(username, password))
}
// parseRequestLine parses "GET /foo HTTP/1.1" into its three parts.
func parseRequestLine(line string) (method, requestURI, proto string, ok bool) {
s1 := strings.Index(line, " ")
s2 := strings.Index(line[s1+1:], " ")
if s1 < 0 || s2 < 0 {
return
}
s2 += s1 + 1
return line[:s1], line[s1+1 : s2], line[s2+1:], true
}
var textprotoReaderPool sync.Pool
func newTextprotoReader(br *bufio.Reader) *textproto.Reader {
if v := textprotoReaderPool.Get(); v != nil {
tr := v.(*textproto.Reader)
tr.R = br
return tr
}
return textproto.NewReader(br)
}
func putTextprotoReader(r *textproto.Reader) {
r.R = nil
textprotoReaderPool.Put(r)
}
// ReadRequest reads and parses an incoming request from b.
func ReadRequest(b *bufio.Reader) (req *Request, err error) {
tp := newTextprotoReader(b)
req = new(Request)
// First line: GET /index.html HTTP/1.0
var s string
if s, err = tp.ReadLine(); err != nil {
return nil, err
}
defer func() {
putTextprotoReader(tp)
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
}()
var ok bool
req.Method, req.RequestURI, req.Proto, ok = parseRequestLine(s)
if !ok {
return nil, &badStringError{"malformed HTTP request", s}
}
rawurl := req.RequestURI
if req.ProtoMajor, req.ProtoMinor, ok = ParseHTTPVersion(req.Proto); !ok {
return nil, &badStringError{"malformed HTTP version", req.Proto}
}
justAuthority := req.Method == "CONNECT" && !strings.HasPrefix(rawurl, "/")
if justAuthority {
rawurl = "http://" + rawurl
}
if req.URL, err = url.ParseRequestURI(rawurl); err != nil {
return nil, err
}
if justAuthority {
req.URL.Scheme = ""
}
mimeHeader, err := tp.ReadMIMEHeader()
if err != nil {
return nil, err
}
req.Header = Header(mimeHeader)
req.Host = req.URL.Host
if req.Host == "" {
req.Host = req.Header.get("Host")
}
delete(req.Header, "Host")
fixPragmaCacheControl(req.Header)
req.Close = shouldClose(req.ProtoMajor, req.ProtoMinor, req.Header, false)
err = readTransfer(req, b)
if err != nil {
return nil, err
}
return req, nil
}
// MaxBytesReader is similar to io.LimitReader but is intended for
// limiting the size of incoming request bodies. In contrast to
// io.LimitReader, MaxBytesReader's result is a ReadCloser, returns a
// non-EOF error for a Read beyond the limit, and closes the
// underlying reader when its Close method is called.
//
// MaxBytesReader prevents clients from accidentally or maliciously
// sending a large request and wasting server resources.
func MaxBytesReader(w ResponseWriter, r io.ReadCloser, n int64) io.ReadCloser {
return &maxBytesReader{w: w, r: r, n: n}
}
type maxBytesReader struct {
w ResponseWriter
r io.ReadCloser // underlying reader
n int64 // max bytes remaining
stopped bool
sawEOF bool
}
func (l *maxBytesReader) tooLarge() (n int, err error) {
if !l.stopped {
l.stopped = true
if res, ok := l.w.(*response); ok {
res.requestTooLarge()
}
}
return 0, errors.New("http: request body too large")
}
func (l *maxBytesReader) Read(p []byte) (n int, err error) {
toRead := l.n
if l.n == 0 {
if l.sawEOF {
return l.tooLarge()
}
toRead = 1
}
if int64(len(p)) > toRead {
p = p[:toRead]
}
n, err = l.r.Read(p)
if err == io.EOF {
l.sawEOF = true
}
if l.n == 0 {
if n > 0 {
return l.tooLarge()
}
return 0, err
}
l.n -= int64(n)
if l.n < 0 {
l.n = 0
}
return
}
func (l *maxBytesReader) Close() error {
return l.r.Close()
}
func copyValues(dst, src url.Values) {
for k, vs := range src {
for _, value := range vs {
dst.Add(k, value)
}
}
}
func parsePostForm(r *Request) (vs url.Values, err error) {
if r.Body == nil {
err = errors.New("missing form body")
return
}
ct := r.Header.Get("Content-Type")
if ct == "" {
ct = "application/octet-stream"
}
ct, _, err = mime.ParseMediaType(ct)
switch {
case ct == "application/x-www-form-urlencoded":
var reader io.Reader = r.Body
maxFormSize := int64(1<<63 - 1)
if _, ok := r.Body.(*maxBytesReader); !ok {
maxFormSize = int64(10 << 20)
reader = io.LimitReader(r.Body, maxFormSize+1)
}
b, e := ioutil.ReadAll(reader)
if e != nil {
if err == nil {
err = e
}
break
}
if int64(len(b)) > maxFormSize {
err = errors.New("http: POST too large")
return
}
vs, e = url.ParseQuery(string(b))
if err == nil {
err = e
}
case ct == "multipart/form-data":
}
return
}
// ParseForm parses the raw query from the URL and updates r.Form.
//
// For POST or PUT requests, it also parses the request body as a form and
// put the results into both r.PostForm and r.Form.
// POST and PUT body parameters take precedence over URL query string values
// in r.Form.
//
// If the request Body's size has not already been limited by MaxBytesReader,
// the size is capped at 10MB.
//
// ParseMultipartForm calls ParseForm automatically.
// It is idempotent.
func (r *Request) ParseForm() error {
var err error
if r.PostForm == nil {
if r.Method == "POST" || r.Method == "PUT" || r.Method == "PATCH" {
r.PostForm, err = parsePostForm(r)
}
if r.PostForm == nil {
r.PostForm = make(url.Values)
}
}
if r.Form == nil {
if len(r.PostForm) > 0 {
r.Form = make(url.Values)
copyValues(r.Form, r.PostForm)
}
var newValues url.Values
if r.URL != nil {
var e error
newValues, e = url.ParseQuery(r.URL.RawQuery)
if err == nil {
err = e
}
}
if newValues == nil {
newValues = make(url.Values)
}
if r.Form == nil {
r.Form = newValues
} else {
copyValues(r.Form, newValues)
}
}
return err
}
// ParseMultipartForm parses a request body as multipart/form-data.
// The whole request body is parsed and up to a total of maxMemory bytes of
// its file parts are stored in memory, with the remainder stored on
// disk in temporary files.
// ParseMultipartForm calls ParseForm if necessary.
// After one call to ParseMultipartForm, subsequent calls have no effect.
func (r *Request) ParseMultipartForm(maxMemory int64) error {
if r.MultipartForm == multipartByReader {
return errors.New("http: multipart handled by MultipartReader")
}
if r.Form == nil {
err := r.ParseForm()
if err != nil {
return err
}
}
if r.MultipartForm != nil {
return nil
}
mr, err := r.multipartReader()
if err != nil {
return err
}
f, err := mr.ReadForm(maxMemory)
if err != nil {
return err
}
for k, v := range f.Value {
r.Form[k] = append(r.Form[k], v...)
}
r.MultipartForm = f
return nil
}
// FormValue returns the first value for the named component of the query.
// POST and PUT body parameters take precedence over URL query string values.
// FormValue calls ParseMultipartForm and ParseForm if necessary and ignores
// any errors returned by these functions.
// If key is not present, FormValue returns the empty string.
// To access multiple values of the same key, call ParseForm and
// then inspect Request.Form directly.
func (r *Request) FormValue(key string) string {
if r.Form == nil {
r.ParseMultipartForm(defaultMaxMemory)
}
if vs := r.Form[key]; len(vs) > 0 {
return vs[0]
}
return ""
}
// PostFormValue returns the first value for the named component of the POST
// or PUT request body. URL query parameters are ignored.
// PostFormValue calls ParseMultipartForm and ParseForm if necessary and ignores
// any errors returned by these functions.
// If key is not present, PostFormValue returns the empty string.
func (r *Request) PostFormValue(key string) string {
if r.PostForm == nil {
r.ParseMultipartForm(defaultMaxMemory)
}
if vs := r.PostForm[key]; len(vs) > 0 {
return vs[0]
}
return ""
}
// FormFile returns the first file for the provided form key.
// FormFile calls ParseMultipartForm and ParseForm if necessary.
func (r *Request) FormFile(key string) (multipart.File, *multipart.FileHeader, error) {
if r.MultipartForm == multipartByReader {
return nil, nil, errors.New("http: multipart handled by MultipartReader")
}
if r.MultipartForm == nil {
err := r.ParseMultipartForm(defaultMaxMemory)
if err != nil {
return nil, nil, err
}
}
if r.MultipartForm != nil && r.MultipartForm.File != nil {
if fhs := r.MultipartForm.File[key]; len(fhs) > 0 {
f, err := fhs[0].Open()
return f, fhs[0], err
}
}
return nil, nil, ErrMissingFile
}
func (r *Request) expectsContinue() bool {
return hasToken(r.Header.get("Expect"), "100-continue")
}
func (r *Request) wantsHttp10KeepAlive() bool {
if r.ProtoMajor != 1 || r.ProtoMinor != 0 {
return false
}
return hasToken(r.Header.get("Connection"), "keep-alive")
}
func (r *Request) wantsClose() bool {
return hasToken(r.Header.get("Connection"), "close")
}
func (r *Request) closeBody() {
if r.Body != nil {
r.Body.Close()
}
}
var respExcludeHeader = map[string]bool{
"Content-Length": true,
"Transfer-Encoding": true,
"Trailer": true,
}
// Response represents the response from an HTTP request.
//
type Response struct {
Status string // e.g. "200 OK"
StatusCode int // e.g. 200
Proto string // e.g. "HTTP/1.0"
ProtoMajor int // e.g. 1
ProtoMinor int // e.g. 0
// Header maps header keys to values. If the response had multiple
// headers with the same key, they may be concatenated, with comma
// delimiters. (Section 4.2 of RFC 2616 requires that multiple headers
// be semantically equivalent to a comma-delimited sequence.) Values
// duplicated by other fields in this struct (e.g., ContentLength) are
// omitted from Header.
//
// Keys in the map are canonicalized (see CanonicalHeaderKey).
Header Header
// Body represents the response body.
//
// 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. It is the caller's responsibility to
// close Body. The default HTTP client's Transport does not
// attempt to reuse HTTP/1.0 or HTTP/1.1 TCP connections
// ("keep-alive") unless the Body is read to completion and is
// closed.
//
// The Body is automatically dechunked if the server replied
// with a "chunked" Transfer-Encoding.
Body io.ReadCloser
// ContentLength records the length of the associated content. The
// value -1 indicates that the length is unknown. Unless Request.Method
// is "HEAD", values >= 0 indicate that the given number of bytes may
// be read from Body.
ContentLength int64
// Contains transfer encodings from outer-most to inner-most. Value is
// nil, means that "identity" encoding is used.
TransferEncoding []string
// Close records whether the header directed that the connection be
// closed after reading Body. The value is advice for clients: neither
// ReadResponse nor Response.Write ever closes a connection.
Close bool
// Trailer maps trailer keys to values, in the same
// format as the header.
Trailer Header
// The Request that was sent to obtain this Response.
// Request's Body is nil (having already been consumed).
// This is only populated for Client requests.
Request *Request
// TLS contains information about the TLS connection on which the
// response was received. It is nil for unencrypted responses.
// The pointer is shared between responses and should not be
// modified.
TLS *tls.ConnectionState
}
// Cookies parses and returns the cookies set in the Set-Cookie headers.
func (r *Response) Cookies() []*Cookie {
return readSetCookies(r.Header)
}
// ErrNoLocation is returned by Response's Location method
// when no Location header is present.
var ErrNoLocation = errors.New("http: no Location header in response")
// Location returns the URL of the response's "Location" header,
// if present. Relative redirects are resolved relative to
// the Response's Request. ErrNoLocation is returned if no
// Location header is present.
func (r *Response) Location() (*url.URL, error) {
lv := r.Header.Get("Location")
if lv == "" {
return nil, ErrNoLocation
}
if r.Request != nil && r.Request.URL != nil {
return r.Request.URL.Parse(lv)
}
return url.Parse(lv)
}
// ReadResponse reads and returns an HTTP response from r.
// The req parameter optionally specifies the Request that corresponds
// to this Response. If nil, a GET request is assumed.
// Clients must call resp.Body.Close when finished reading resp.Body.
// After that call, clients can inspect resp.Trailer to find key/value
// pairs included in the response trailer.
func ReadResponse(r *bufio.Reader, req *Request) (*Response, error) {
tp := textproto.NewReader(r)
resp := &Response{
Request: req,
}
line, err := tp.ReadLine()
if err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return nil, err
}
f := strings.SplitN(line, " ", 3)
if len(f) < 2 {
return nil, &badStringError{"malformed HTTP response", line}
}
reasonPhrase := ""
if len(f) > 2 {
reasonPhrase = f[2]
}
resp.Status = f[1] + " " + reasonPhrase
resp.StatusCode, err = strconv.Atoi(f[1])
if err != nil {
return nil, &badStringError{"malformed HTTP status code", f[1]}
}
resp.Proto = f[0]
var ok bool
if resp.ProtoMajor, resp.ProtoMinor, ok = ParseHTTPVersion(resp.Proto); !ok {
return nil, &badStringError{"malformed HTTP version", resp.Proto}
}
mimeHeader, err := tp.ReadMIMEHeader()
if err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return nil, err
}
resp.Header = Header(mimeHeader)
fixPragmaCacheControl(resp.Header)
err = readTransfer(resp, r)
if err != nil {
return nil, err
}
return resp, nil
}
// RFC2616: Should treat
// Pragma: no-cache
// like
// Cache-Control: no-cache
func fixPragmaCacheControl(header Header) {
if hp, ok := header["Pragma"]; ok && len(hp) > 0 && hp[0] == "no-cache" {
if _, presentcc := header["Cache-Control"]; !presentcc {
header["Cache-Control"] = []string{"no-cache"}
}
}
}
// ProtoAtLeast reports whether the HTTP protocol used
// in the response is at least major.minor.
func (r *Response) ProtoAtLeast(major, minor int) bool {
return r.ProtoMajor > major ||
r.ProtoMajor == major && r.ProtoMinor >= minor
}
// Write writes r to w in the HTTP/1.n server response format,
// including the status line, headers, body, and optional trailer.
//
// This method consults the following fields of the response r:
//
// StatusCode
// ProtoMajor
// ProtoMinor
// Request.Method
// TransferEncoding
// Trailer
// Body
// ContentLength
// Header, values for non-canonical keys will have unpredictable behavior
//
// The Response Body is closed after it is sent.
func (r *Response) Write(w io.Writer) error {
text := r.Status
if text == "" {
var ok bool
text, ok = statusText[r.StatusCode]
if !ok {
text = "status code " + strconv.Itoa(r.StatusCode)
}
}
protoMajor, protoMinor := strconv.Itoa(r.ProtoMajor), strconv.Itoa(r.ProtoMinor)
statusCode := strconv.Itoa(r.StatusCode) + " "
text = strings.TrimPrefix(text, statusCode)
if _, err := io.WriteString(w, "HTTP/"+protoMajor+"."+protoMinor+" "+statusCode+text+"\r\n"); err != nil {
return err
}
r1 := new(Response)
*r1 = *r
if r1.ContentLength == 0 && r1.Body != nil {
// Is it actually 0 length? Or just unknown?
var buf [1]byte
n, err := r1.Body.Read(buf[:])
if err != nil && err != io.EOF {
return err
}
if n == 0 {
r1.Body = eofReader
} else {
r1.ContentLength = -1
r1.Body = struct {
io.Reader
io.Closer
}{
io.MultiReader(bytes.NewReader(buf[:1]), r.Body),
r.Body,
}
}
}
if r1.ContentLength == -1 && !r1.Close && r1.ProtoAtLeast(1, 1) && !chunked(r1.TransferEncoding) {
r1.Close = true
}
tw, err := newTransferWriter(r1)
if err != nil {
return err
}
err = tw.WriteHeader(w)
if err != nil {
return err
}
err = r.Header.WriteSubset(w, respExcludeHeader)
if err != nil {
return err
}
contentLengthAlreadySent := tw.shouldSendContentLength()
if r1.ContentLength == 0 && !chunked(r1.TransferEncoding) && !contentLengthAlreadySent {
if _, err := io.WriteString(w, "Content-Length: 0\r\n"); err != nil {
return err
}
}
if _, err := io.WriteString(w, "\r\n"); err != nil {
return err
}
err = tw.WriteBody(w)
if err != nil {
return err
}
return nil
}
// Errors introduced by the HTTP server.
var (
ErrWriteAfterFlush = errors.New("Conn.Write called after Flush")
ErrBodyNotAllowed = errors.New("http: request method or response status code does not allow body")
ErrHijacked = errors.New("Conn has been hijacked")
ErrContentLength = errors.New("Conn.Write wrote more than the declared Content-Length")
)
// Objects implementing the Handler interface can be
// registered to serve a particular path or subtree
// in the HTTP server.
//
// ServeHTTP should write reply headers and data to the ResponseWriter
// and then return. Returning signals that the request is finished
// and that the HTTP server can move on to the next request on
// the connection.
//
// If ServeHTTP panics, the server (the caller of ServeHTTP) assumes
// that the effect of the panic was isolated to the active request.
// It recovers the panic, logs a stack trace to the server error log,
// and hangs up the connection.
//
type Handler interface {
ServeHTTP(ResponseWriter, *Request)
}
// A ResponseWriter interface is used by an HTTP handler to
// construct an HTTP response.
type ResponseWriter interface {
// Header returns the header map that will be sent by
// WriteHeader. Changing the header after a call to
// WriteHeader (or Write) has no effect unless the modified
// headers were declared as trailers by setting the
// "Trailer" header before the call to WriteHeader (see example).
// To suppress implicit response headers, set their value to nil.
Header() Header
// Write writes the data to the connection as part of an HTTP reply.
// If WriteHeader has not yet been called, Write calls WriteHeader(http.StatusOK)
// before writing the data. If the Header does not contain a
// Content-Type line, Write adds a Content-Type set to the result of passing
// the initial 512 bytes of written data to DetectContentType.
Write([]byte) (int, error)
// WriteHeader sends an HTTP response header with status code.
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
// Thus explicit calls to WriteHeader are mainly used to
// send error codes.
WriteHeader(int)
}
// The Flusher interface is implemented by ResponseWriters that allow
// an HTTP handler to flush buffered data to the client.
//
// Note that even for ResponseWriters that support Flush,
// if the client is connected through an HTTP proxy,
// the buffered data may not reach the client until the response
// completes.
type Flusher interface {
// Flush sends any buffered data to the client.
Flush()
}
// The Hijacker interface is implemented by ResponseWriters that allow
// an HTTP handler to take over the connection.
type Hijacker interface {
// Hijack lets the caller take over the connection.
// After a call to Hijack(), the HTTP server library
// will not do anything else with the connection.
//
// It becomes the caller's responsibility to manage
// and close the connection.
//
// The returned net.Conn may have read or write deadlines
// already set, depending on the configuration of the
// Server. It is the caller's responsibility to set
// or clear those deadlines as needed.
Hijack() (net.Conn, *bufio.ReadWriter, error)
}
// The CloseNotifier interface is implemented by ResponseWriters which
// allow detecting when the underlying connection has gone away.
//
// This mechanism can be used to cancel long operations on the server
// if the client has disconnected before the response is ready.
type CloseNotifier interface {
// CloseNotify returns a channel that receives a single value
// when the client connection has gone away.
CloseNotify() <-chan bool
}
// A conn represents the server side of an HTTP connection.
type conn struct {
remoteAddr string // network address of remote side
server *Server // the Server on which the connection arrived
rwc net.Conn // i/o connection
w io.Writer // checkConnErrorWriter's copy of wrc, not zeroed on Hijack
werr error // any errors writing to w
sr liveSwitchReader // where the LimitReader reads from; usually the rwc
lr *io.LimitedReader // io.LimitReader(sr)
buf *bufio.ReadWriter // buffered(lr,rwc), reading from bufio->limitReader->sr->rwc
tlsState *tls.ConnectionState // or nil when not using TLS
lastMethod string // method of previous request, or ""
mu sync.Mutex // guards the following
clientGone bool // if client has disconnected mid-request
closeNotifyc chan bool // made lazily
hijackedv bool // connection has been hijacked by handler
}
func (c *conn) hijacked() bool {
c.mu.Lock()
defer c.mu.Unlock()
return c.hijackedv
}
func (c *conn) hijack() (rwc net.Conn, buf *bufio.ReadWriter, err error) {
c.mu.Lock()
defer c.mu.Unlock()
if c.hijackedv {
return nil, nil, ErrHijacked
}
if c.closeNotifyc != nil {
return nil, nil, errors.New("http: Hijack is incompatible with use of CloseNotifier")
}
c.hijackedv = true
rwc = c.rwc
buf = c.buf
c.rwc = nil
c.buf = nil
c.setState(rwc, StateHijacked)
return
}
func (c *conn) closeNotify() <-chan bool {
c.mu.Lock()
defer c.mu.Unlock()
if c.closeNotifyc == nil {
c.closeNotifyc = make(chan bool, 1)
if c.hijackedv {
return c.closeNotifyc
}
pr, pw := io.Pipe()
readSource := c.sr.r
c.sr.Lock()
c.sr.r = pr
c.sr.Unlock()
go func() {
_, err := io.Copy(pw, readSource)
if err == nil {
err = io.EOF
}
pw.CloseWithError(err)
c.noteClientGone()
}()
}
return c.closeNotifyc
}
func (c *conn) noteClientGone() {
c.mu.Lock()
defer c.mu.Unlock()
if c.closeNotifyc != nil && !c.clientGone {
c.closeNotifyc <- true
}
c.clientGone = true
}
// A switchWriter can have its Writer changed at runtime.
// It's not safe for concurrent Writes and switches.
type switchWriter struct {
io.Writer
}
// A liveSwitchReader can have its Reader changed at runtime. It's
// safe for concurrent reads and switches, if its mutex is held.
type liveSwitchReader struct {
sync.Mutex
r io.Reader
}
func (sr *liveSwitchReader) Read(p []byte) (n int, err error) {
sr.Lock()
r := sr.r
sr.Unlock()
return r.Read(p)
}
// This should be >= 512 bytes for DetectContentType,
// but otherwise it's somewhat arbitrary.
const bufferBeforeChunkingSize = 2048
// chunkWriter writes to a response's conn buffer, and is the writer
// wrapped by the response.bufw buffered writer.
//
// chunkWriter also is responsible for finalizing the Header, including
// conditionally setting the Content-Type and setting a Content-Length
// in cases where the handler's final output is smaller than the buffer
// size. It also conditionally adds chunk headers, when in chunking mode.
//
// See the comment above (*response).Write for the entire write flow.
type chunkWriter struct {
res *response
// header is either nil or a deep clone of res.handlerHeader
// at the time of res.WriteHeader, if res.WriteHeader is
// called and extra buffering is being done to calculate
// Content-Type and/or Content-Length.
header Header
// wroteHeader tells whether the header's been written to "the
// wire" (or rather: w.conn.buf). this is unlike
// (*response).wroteHeader, which tells only whether it was
// logically written.
wroteHeader bool
// set by the writeHeader method:
chunking bool // using chunked transfer encoding for reply body
}
var (
crlf = []byte("\r\n")
colonSpace = []byte(": ")
)
func (cw *chunkWriter) Write(p []byte) (n int, err error) {
if !cw.wroteHeader {
cw.writeHeader(p)
}
if cw.res.req.Method == "HEAD" {
return len(p), nil
}
if cw.chunking {
_, err = fmt.Fprintf(cw.res.conn.buf, "%x\r\n", len(p))
if err != nil {
cw.res.conn.rwc.Close()
return
}
}
n, err = cw.res.conn.buf.Write(p)
if cw.chunking && err == nil {
_, err = cw.res.conn.buf.Write(crlf)
}
if err != nil {
cw.res.conn.rwc.Close()
}
return
}
func (cw *chunkWriter) flush() {
if !cw.wroteHeader {
cw.writeHeader(nil)
}
cw.res.conn.buf.Flush()
}
func (cw *chunkWriter) close() {
if !cw.wroteHeader {
cw.writeHeader(nil)
}
if cw.chunking {
bw := cw.res.conn.buf
bw.WriteString("0\r\n")
if len(cw.res.trailers) > 0 {
trailers := make(Header)
for _, h := range cw.res.trailers {
if vv := cw.res.handlerHeader[h]; len(vv) > 0 {
trailers[h] = vv
}
}
trailers.Write(bw)
}
bw.WriteString("\r\n")
}
}
// A response represents the server side of an HTTP response.
type response struct {
conn *conn
req *Request // request for this response
wroteHeader bool // reply header has been (logically) written
wroteContinue bool // 100 Continue response was written
w *bufio.Writer // buffers output in chunks to chunkWriter
cw chunkWriter
sw *switchWriter // of the bufio.Writer, for return to putBufioWriter
// handlerHeader is the Header that Handlers get access to,
// which may be retained and mutated even after WriteHeader.
// handlerHeader is copied into cw.header at WriteHeader
// time, and privately mutated thereafter.
handlerHeader Header
calledHeader bool // handler accessed handlerHeader via Header
written int64 // number of bytes written in body
contentLength int64 // explicitly-declared Content-Length; or -1
status int // status code passed to WriteHeader
// close connection after this reply. set on request and
// updated after response from handler if there's a
// "Connection: keep-alive" response header and a
// Content-Length.
closeAfterReply bool
// requestBodyLimitHit is set by requestTooLarge when
// maxBytesReader hits its max size. It is checked in
// WriteHeader, to make sure we don't consume the
// remaining request body to try to advance to the next HTTP
// request. Instead, when this is set, we stop reading
// subsequent requests on this connection and stop reading
// input from it.
requestBodyLimitHit bool
// trailers are the headers to be sent after the handler
// finishes writing the body. This field is initialized from
// the Trailer response header when the response header is
// written.
trailers []string
handlerDone bool // set true when the handler exits
// Buffers for Date and Content-Length
dateBuf [len(TimeFormat)]byte
clenBuf [10]byte
}
// declareTrailer is called for each Trailer header when the
// response header is written. It notes that a header will need to be
// written in the trailers at the end of the response.
func (w *response) declareTrailer(k string) {
k = CanonicalHeaderKey(k)
switch k {
case "Transfer-Encoding", "Content-Length", "Trailer":
return
}
w.trailers = append(w.trailers, k)
}
// requestTooLarge is called by maxBytesReader when too much input has
// been read from the client.
func (w *response) requestTooLarge() {
w.closeAfterReply = true
w.requestBodyLimitHit = true
if !w.wroteHeader {
w.Header().Set("Connection", "close")
}
}
// needsSniff reports whether a Content-Type still needs to be sniffed.
func (w *response) needsSniff() bool {
_, haveType := w.handlerHeader["Content-Type"]
return !w.cw.wroteHeader && !haveType && w.written < sniffLen
}
// writerOnly hides an io.Writer value's optional ReadFrom method
// from io.Copy.
type writerOnly struct {
io.Writer
}
func srcIsRegularFile(src io.Reader) (isRegular bool, err error) {
switch v := src.(type) {
case *os.File:
fi, err := v.Stat()
if err != nil {
return false, err
}
return fi.Mode().IsRegular(), nil
case *io.LimitedReader:
return srcIsRegularFile(v.R)
default:
return
}
}
// ReadFrom is here to optimize copying from an *os.File regular file
// to a *net.TCPConn with sendfile.
func (w *response) ReadFrom(src io.Reader) (n int64, err error) {
rf, ok := w.conn.rwc.(io.ReaderFrom)
regFile, err := srcIsRegularFile(src)
if err != nil {
return 0, err
}
if !ok || !regFile {
return io.Copy(writerOnly{w}, src)
}
if !w.wroteHeader {
w.WriteHeader(StatusOK)
}
if w.needsSniff() {
n0, err := io.Copy(writerOnly{w}, io.LimitReader(src, sniffLen))
n += n0
if err != nil {
return n, err
}
}
w.w.Flush()
w.cw.flush()
if !w.cw.chunking && w.bodyAllowed() {
n0, err := rf.ReadFrom(src)
n += n0
w.written += n0
return n, err
}
n0, err := io.Copy(writerOnly{w}, src)
n += n0
return n, err
}
// noLimit is an effective infinite upper bound for io.LimitedReader
const noLimit int64 = (1 << 63) - 1
// debugServerConnections controls whether all server connections are wrapped
// with a verbose logging wrapper.
const debugServerConnections = false
// Create new connection from rwc.
func (srv *Server) newConn(rwc net.Conn) (c *conn, err error) {
c = new(conn)
c.remoteAddr = rwc.RemoteAddr().String()
c.server = srv
c.rwc = rwc
c.w = rwc
if debugServerConnections {
c.rwc = newLoggingConn("server", c.rwc)
}
c.sr.r = c.rwc
c.lr = io.LimitReader(&c.sr, noLimit).(*io.LimitedReader)
br := newBufioReader(c.lr)
bw := newBufioWriterSize(checkConnErrorWriter{c}, 4<<10)
c.buf = bufio.NewReadWriter(br, bw)
return c, nil
}
var (
bufioReaderPool sync.Pool
bufioWriter2kPool sync.Pool
bufioWriter4kPool sync.Pool
)
func bufioWriterPool(size int) *sync.Pool {
switch size {
case 2 << 10:
return &bufioWriter2kPool
case 4 << 10:
return &bufioWriter4kPool
}
return nil
}
func newBufioReader(r io.Reader) *bufio.Reader {
if v := bufioReaderPool.Get(); v != nil {
br := v.(*bufio.Reader)
br.Reset(r)
return br
}
return bufio.NewReader(r)
}
func putBufioReader(br *bufio.Reader) {
br.Reset(nil)
bufioReaderPool.Put(br)
}
func newBufioWriterSize(w io.Writer, size int) *bufio.Writer {
pool := bufioWriterPool(size)
if pool != nil {
if v := pool.Get(); v != nil {
bw := v.(*bufio.Writer)
bw.Reset(w)
return bw
}
}
return bufio.NewWriterSize(w, size)
}
func putBufioWriter(bw *bufio.Writer) {
bw.Reset(nil)
if pool := bufioWriterPool(bw.Available()); pool != nil {
pool.Put(bw)
}
}
// DefaultMaxHeaderBytes is the maximum permitted size of the headers
// in an HTTP request.
// This can be overridden by setting Server.MaxHeaderBytes.
const DefaultMaxHeaderBytes = 1 << 20 // 1 MB
func (srv *Server) maxHeaderBytes() int {
if srv.MaxHeaderBytes > 0 {
return srv.MaxHeaderBytes
}
return DefaultMaxHeaderBytes
}
func (srv *Server) initialLimitedReaderSize() int64 {
return int64(srv.maxHeaderBytes()) + 4096
}
// wrapper around io.ReaderCloser which on first read, sends an
// HTTP/1.1 100 Continue header
type expectContinueReader struct {
resp *response
readCloser io.ReadCloser
closed bool
sawEOF bool
}
func (ecr *expectContinueReader) Read(p []byte) (n int, err error) {
if ecr.closed {
return 0, ErrBodyReadAfterClose
}
if !ecr.resp.wroteContinue && !ecr.resp.conn.hijacked() {
ecr.resp.wroteContinue = true
ecr.resp.conn.buf.WriteString("HTTP/1.1 100 Continue\r\n\r\n")
ecr.resp.conn.buf.Flush()
}
n, err = ecr.readCloser.Read(p)
if err == io.EOF {
ecr.sawEOF = true
}
return
}
func (ecr *expectContinueReader) Close() error {
ecr.closed = true
return ecr.readCloser.Close()
}
// TimeFormat is the time format to use with
// time.Parse and time.Time.Format when parsing
// or generating times in HTTP headers.
// It is like time.RFC1123 but hard codes GMT as the time zone.
const TimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
// appendTime is a non-allocating version of []byte(t.UTC().Format(TimeFormat))
func appendTime(b []byte, t time.Time) []byte {
const days = "SunMonTueWedThuFriSat"
const months = "JanFebMarAprMayJunJulAugSepOctNovDec"
t = t.UTC()
yy, mm, dd := t.Date()
hh, mn, ss := t.Clock()
day := days[3*t.Weekday():]
mon := months[3*(mm-1):]
return append(b,
day[0], day[1], day[2], ',', ' ',
byte('0'+dd/10), byte('0'+dd%10), ' ',
mon[0], mon[1], mon[2], ' ',
byte('0'+yy/1000), byte('0'+(yy/100)%10), byte('0'+(yy/10)%10), byte('0'+yy%10), ' ',
byte('0'+hh/10), byte('0'+hh%10), ':',
byte('0'+mn/10), byte('0'+mn%10), ':',
byte('0'+ss/10), byte('0'+ss%10), ' ',
'G', 'M', 'T')
}
var errTooLarge = errors.New("http: request too large")
// Read next request from connection.
func (c *conn) readRequest() (w *response, err error) {
if c.hijacked() {
return nil, ErrHijacked
}
if d := c.server.ReadTimeout; d != 0 {
c.rwc.SetReadDeadline(time.Now().Add(d))
}
if d := c.server.WriteTimeout; d != 0 {
defer func() {
c.rwc.SetWriteDeadline(time.Now().Add(d))
}()
}
c.lr.N = c.server.initialLimitedReaderSize()
if c.lastMethod == "POST" {
peek, _ := c.buf.Reader.Peek(4)
c.buf.Reader.Discard(numLeadingCRorLF(peek))
}
var req *Request
if req, err = ReadRequest(c.buf.Reader); err != nil {
if c.lr.N == 0 {
return nil, errTooLarge
}
return nil, err
}
c.lr.N = noLimit
c.lastMethod = req.Method
req.RemoteAddr = c.remoteAddr
req.TLS = c.tlsState
if body, ok := req.Body.(*body); ok {
body.doEarlyClose = true
}
w = &response{
conn: c,
req: req,
handlerHeader: make(Header),
contentLength: -1,
}
w.cw.res = w
w.w = newBufioWriterSize(&w.cw, bufferBeforeChunkingSize)
return w, nil
}
func (w *response) Header() Header {
if w.cw.header == nil && w.wroteHeader && !w.cw.wroteHeader {
w.cw.header = w.handlerHeader.clone()
}
w.calledHeader = true
return w.handlerHeader
}
// maxPostHandlerReadBytes is the max number of Request.Body bytes not
// consumed by a handler that the server will read from the client
// in order to keep a connection alive. If there are more bytes than
// this then the server to be paranoid instead sends a "Connection:
// close" response.
//
// This number is approximately what a typical machine's TCP buffer
// size is anyway. (if we have the bytes on the machine, we might as
// well read them)
const maxPostHandlerReadBytes = 256 << 10
func (w *response) WriteHeader(code int) {
if w.conn.hijacked() {
w.conn.server.logf("http: response.WriteHeader on hijacked connection")
return
}
if w.wroteHeader {
w.conn.server.logf("http: multiple response.WriteHeader calls")
return
}
w.wroteHeader = true
w.status = code
if w.calledHeader && w.cw.header == nil {
w.cw.header = w.handlerHeader.clone()
}
if cl := w.handlerHeader.get("Content-Length"); cl != "" {
v, err := strconv.ParseInt(cl, 10, 64)
if err == nil && v >= 0 {
w.contentLength = v
} else {
w.conn.server.logf("http: invalid Content-Length of %q", cl)
w.handlerHeader.Del("Content-Length")
}
}
}
// extraHeader is the set of headers sometimes added by chunkWriter.writeHeader.
// This type is used to avoid extra allocations from cloning and/or populating
// the response Header map and all its 1-element slices.
type extraHeader struct {
contentType string
connection string
transferEncoding string
date []byte // written if not nil
contentLength []byte // written if not nil
}
// Sorted the same as extraHeader.Write's loop.
var extraHeaderKeys = [][]byte{
[]byte("Content-Type"),
[]byte("Connection"),
[]byte("Transfer-Encoding"),
}
var (
headerContentLength = []byte("Content-Length: ")
headerDate = []byte("Date: ")
)
// Write writes the headers described in h to w.
//
// This method has a value receiver, despite the somewhat large size
// of h, because it prevents an allocation. The escape analysis isn't
// smart enough to realize this function doesn't mutate h.
func (h extraHeader) Write(w *bufio.Writer) {
if h.date != nil {
w.Write(headerDate)
w.Write(h.date)
w.Write(crlf)
}
if h.contentLength != nil {
w.Write(headerContentLength)
w.Write(h.contentLength)
w.Write(crlf)
}
for i, v := range []string{h.contentType, h.connection, h.transferEncoding} {
if v != "" {
w.Write(extraHeaderKeys[i])
w.Write(colonSpace)
w.WriteString(v)
w.Write(crlf)
}
}
}
// writeHeader finalizes the header sent to the client and writes it
// to cw.res.conn.buf.
//
// p is not written by writeHeader, but is the first chunk of the body
// that will be written. It is sniffed for a Content-Type if none is
// set explicitly. It's also used to set the Content-Length, if the
// total body size was small and the handler has already finished
// running.
func (cw *chunkWriter) writeHeader(p []byte) {
if cw.wroteHeader {
return
}
cw.wroteHeader = true
w := cw.res
keepAlivesEnabled := w.conn.server.doKeepAlives()
isHEAD := w.req.Method == "HEAD"
header := cw.header
owned := header != nil
if !owned {
header = w.handlerHeader
}
var excludeHeader map[string]bool
delHeader := func(key string) {
if owned {
header.Del(key)
return
}
if _, ok := header[key]; !ok {
return
}
if excludeHeader == nil {
excludeHeader = make(map[string]bool)
}
excludeHeader[key] = true
}
var setHeader extraHeader
trailers := false
for _, v := range cw.header["Trailer"] {
trailers = true
foreachHeaderElement(v, cw.res.declareTrailer)
}
te := header.get("Transfer-Encoding")
hasTE := te != ""
if w.handlerDone && !trailers && !hasTE && bodyAllowedForStatus(w.status) && header.get("Content-Length") == "" && (!isHEAD || len(p) > 0) {
w.contentLength = int64(len(p))
setHeader.contentLength = strconv.AppendInt(cw.res.clenBuf[:0], int64(len(p)), 10)
}
if w.req.wantsHttp10KeepAlive() && keepAlivesEnabled {
sentLength := header.get("Content-Length") != ""
if sentLength && header.get("Connection") == "keep-alive" {
w.closeAfterReply = false
}
}
hasCL := w.contentLength != -1
if w.req.wantsHttp10KeepAlive() && (isHEAD || hasCL) {
_, connectionHeaderSet := header["Connection"]
if !connectionHeaderSet {
setHeader.connection = "keep-alive"
}
} else if !w.req.ProtoAtLeast(1, 1) || w.req.wantsClose() {
w.closeAfterReply = true
}
if header.get("Connection") == "close" || !keepAlivesEnabled {
w.closeAfterReply = true
}
if ecr, ok := w.req.Body.(*expectContinueReader); ok && !ecr.sawEOF {
w.closeAfterReply = true
}
if w.req.ContentLength != 0 && !w.closeAfterReply {
var discard, tooBig bool
switch bdy := w.req.Body.(type) {
case *expectContinueReader:
if bdy.resp.wroteContinue {
discard = true
}
case *body:
bdy.mu.Lock()
switch {
case bdy.closed:
if !bdy.sawEOF {
w.closeAfterReply = true
}
case bdy.unreadDataSizeLocked() >= maxPostHandlerReadBytes:
tooBig = true
default:
discard = true
}
bdy.mu.Unlock()
default:
discard = true
}
if discard {
_, err := io.CopyN(ioutil.Discard, w.req.Body, maxPostHandlerReadBytes+1)
switch err {
case nil:
tooBig = true
case ErrBodyReadAfterClose:
case io.EOF:
err = w.req.Body.Close()
if err != nil {
w.closeAfterReply = true
}
default:
w.closeAfterReply = true
}
}
if tooBig {
w.requestTooLarge()
delHeader("Connection")
setHeader.connection = "close"
}
}
code := w.status
if bodyAllowedForStatus(code) {
_, haveType := header["Content-Type"]
if !haveType && !hasTE {
setHeader.contentType = DetectContentType(p)
}
} else {
for _, k := range suppressedHeaders(code) {
delHeader(k)
}
}
if _, ok := header["Date"]; !ok {
setHeader.date = appendTime(cw.res.dateBuf[:0], time.Now())
}
if hasCL && hasTE && te != "identity" {
w.conn.server.logf("http: WriteHeader called with both Transfer-Encoding of %q and a Content-Length of %d",
te, w.contentLength)
delHeader("Content-Length")
hasCL = false
}
if w.req.Method == "HEAD" || !bodyAllowedForStatus(code) {
} else if code == StatusNoContent {
delHeader("Transfer-Encoding")
} else if hasCL {
delHeader("Transfer-Encoding")
} else if w.req.ProtoAtLeast(1, 1) {
if hasTE && te == "identity" {
cw.chunking = false
w.closeAfterReply = true
} else {
cw.chunking = true
setHeader.transferEncoding = "chunked"
}
} else {
w.closeAfterReply = true
delHeader("Transfer-Encoding")
}
if cw.chunking {
delHeader("Content-Length")
}
if !w.req.ProtoAtLeast(1, 0) {
return
}
if w.closeAfterReply && (!keepAlivesEnabled || !hasToken(cw.header.get("Connection"), "close")) {
delHeader("Connection")
if w.req.ProtoAtLeast(1, 1) {
setHeader.connection = "close"
}
}
w.conn.buf.WriteString(statusLine(w.req, code))
cw.header.WriteSubset(w.conn.buf, excludeHeader)
setHeader.Write(w.conn.buf.Writer)
w.conn.buf.Write(crlf)
}
// foreachHeaderElement splits v according to the "#rule" construction
// in RFC 2616 section 2.1 and calls fn for each non-empty element.
func foreachHeaderElement(v string, fn func(string)) {
v = textproto.TrimString(v)
if v == "" {
return
}
if !strings.Contains(v, ",") {
fn(v)
return
}
for _, f := range strings.Split(v, ",") {
if f = textproto.TrimString(f); f != "" {
fn(f)
}
}
}
// statusLines is a cache of Status-Line strings, keyed by code (for
// HTTP/1.1) or negative code (for HTTP/1.0). This is faster than a
// map keyed by struct of two fields. This map's max size is bounded
// by 2*len(statusText), two protocol types for each known official
// status code in the statusText map.
var (
statusMu sync.RWMutex
statusLines = make(map[int]string)
)
// statusLine returns a response Status-Line (RFC 2616 Section 6.1)
// for the given request and response status code.
func statusLine(req *Request, code int) string {
key := code
proto11 := req.ProtoAtLeast(1, 1)
if !proto11 {
key = -key
}
statusMu.RLock()
line, ok := statusLines[key]
statusMu.RUnlock()
if ok {
return line
}
proto := "HTTP/1.0"
if proto11 {
proto = "HTTP/1.1"
}
codestring := strconv.Itoa(code)
text, ok := statusText[code]
if !ok {
text = "status code " + codestring
}
line = proto + " " + codestring + " " + text + "\r\n"
if ok {
statusMu.Lock()
defer statusMu.Unlock()
statusLines[key] = line
}
return line
}
// bodyAllowed reports whether a Write is allowed for this response type.
// It's illegal to call this before the header has been flushed.
func (w *response) bodyAllowed() bool {
if !w.wroteHeader {
panic("")
}
return bodyAllowedForStatus(w.status)
}
// The Life Of A Write is like this:
//
// Handler starts. No header has been sent. The handler can either
// write a header, or just start writing. Writing before sending a header
// sends an implicitly empty 200 OK header.
//
// If the handler didn't declare a Content-Length up front, we either
// go into chunking mode or, if the handler finishes running before
// the chunking buffer size, we compute a Content-Length and send that
// in the header instead.
//
// Likewise, if the handler didn't set a Content-Type, we sniff that
// from the initial chunk of output.
//
// The Writers are wired together like:
//
// 1. *response (the ResponseWriter) ->
// 2. (*response).w, a *bufio.Writer of bufferBeforeChunkingSize bytes
// 3. chunkWriter.Writer (whose writeHeader finalizes Content-Length/Type)
// and which writes the chunk headers, if needed.
// 4. conn.buf, a bufio.Writer of default (4kB) bytes, writing to ->
// 5. checkConnErrorWriter{c}, which notes any non-nil error on Write
// and populates c.werr with it if so. but otherwise writes to:
// 6. the rwc, the net.Conn.
//
// TODO(bradfitz): short-circuit some of the buffering when the
// initial header contains both a Content-Type and Content-Length.
// Also short-circuit in (1) when the header's been sent and not in
// chunking mode, writing directly to (4) instead, if (2) has no
// buffered data. More generally, we could short-circuit from (1) to
// (3) even in chunking mode if the write size from (1) is over some
// threshold and nothing is in (2). The answer might be mostly making
// bufferBeforeChunkingSize smaller and having bufio's fast-paths deal
// with this instead.
func (w *response) Write(data []byte) (n int, err error) {
return w.write(len(data), data, "")
}
func (w *response) WriteString(data string) (n int, err error) {
return w.write(len(data), nil, data)
}
// either dataB or dataS is non-zero.
func (w *response) write(lenData int, dataB []byte, dataS string) (n int, err error) {
if w.conn.hijacked() {
w.conn.server.logf("http: response.Write on hijacked connection")
return 0, ErrHijacked
}
if !w.wroteHeader {
w.WriteHeader(StatusOK)
}
if lenData == 0 {
return 0, nil
}
if !w.bodyAllowed() {
return 0, ErrBodyNotAllowed
}
w.written += int64(lenData)
if w.contentLength != -1 && w.written > w.contentLength {
return 0, ErrContentLength
}
if dataB != nil {
return w.w.Write(dataB)
} else {
return w.w.WriteString(dataS)
}
}
func (w *response) finishRequest() {
w.handlerDone = true
if !w.wroteHeader {
w.WriteHeader(StatusOK)
}
w.w.Flush()
putBufioWriter(w.w)
w.cw.close()
w.conn.buf.Flush()
w.req.Body.Close()
if w.req.MultipartForm != nil {
w.req.MultipartForm.RemoveAll()
}
}
// shouldReuseConnection reports whether the underlying TCP connection can be reused.
// It must only be called after the handler is done executing.
func (w *response) shouldReuseConnection() bool {
if w.closeAfterReply {
return false
}
if w.req.Method != "HEAD" && w.contentLength != -1 && w.bodyAllowed() && w.contentLength != w.written {
return false
}
if w.conn.werr != nil {
return false
}
if w.closedRequestBodyEarly() {
return false
}
return true
}
func (w *response) closedRequestBodyEarly() bool {
body, ok := w.req.Body.(*body)
return ok && body.didEarlyClose()
}
func (w *response) Flush() {
if !w.wroteHeader {
w.WriteHeader(StatusOK)
}
w.w.Flush()
w.cw.flush()
}
func (c *conn) finalFlush() {
if c.buf != nil {
c.buf.Flush()
putBufioReader(c.buf.Reader)
putBufioWriter(c.buf.Writer)
c.buf = nil
}
}
// Close the connection.
func (c *conn) close() {
c.finalFlush()
if c.rwc != nil {
c.rwc.Close()
c.rwc = nil
}
}
// rstAvoidanceDelay is the amount of time we sleep after closing the
// write side of a TCP connection before closing the entire socket.
// By sleeping, we increase the chances that the client sees our FIN
// and processes its final data before they process the subsequent RST
// from closing a connection with known unread data.
// This RST seems to occur mostly on BSD systems. (And Windows?)
// This timeout is somewhat arbitrary (~latency around the planet).
const rstAvoidanceDelay = 500 * time.Millisecond
type closeWriter interface {
CloseWrite() error
}
var _ closeWriter = (*net.TCPConn)(nil)
// closeWrite flushes any outstanding data and sends a FIN packet (if
// client is connected via TCP), signalling that we're done. We then
// pause for a bit, hoping the client processes it before any
// subsequent RST.
//
// See https://golang.org/issue/3595
func (c *conn) closeWriteAndWait() {
c.finalFlush()
if tcp, ok := c.rwc.(closeWriter); ok {
tcp.CloseWrite()
}
time.Sleep(rstAvoidanceDelay)
}
// validNPN reports whether the proto is not a blacklisted Next
// Protocol Negotiation protocol. Empty and built-in protocol types
// are blacklisted and can't be overridden with alternate
// implementations.
func validNPN(proto string) bool {
switch proto {
case "", "http/1.1", "http/1.0":
return false
}
return true
}
func (c *conn) setState(nc net.Conn, state ConnState) {
if hook := c.server.ConnState; hook != nil {
hook(nc, state)
}
}
// Serve a new connection.
func (c *conn) serve() {
origConn := c.rwc
defer func() {
if err := recover(); err != nil {
const size = 64 << 10
buf := make([]byte, size)
buf = buf[:runtime.Stack(buf, false)]
c.server.logf("http: panic serving %v: %v\n%s", c.remoteAddr, err, buf)
}
if !c.hijacked() {
c.close()
c.setState(origConn, StateClosed)
}
}()
if tlsConn, ok := c.rwc.(*tls.Conn); ok {
if d := c.server.ReadTimeout; d != 0 {
c.rwc.SetReadDeadline(time.Now().Add(d))
}
if d := c.server.WriteTimeout; d != 0 {
c.rwc.SetWriteDeadline(time.Now().Add(d))
}
if err := tlsConn.Handshake(); err != nil {
c.server.logf("http: TLS handshake error from %s: %v", c.rwc.RemoteAddr(), err)
return
}
c.tlsState = new(tls.ConnectionState)
*c.tlsState = tlsConn.ConnectionState()
if proto := c.tlsState.NegotiatedProtocol; validNPN(proto) {
if fn := c.server.TLSNextProto[proto]; fn != nil {
h := initNPNRequest{tlsConn, serverHandler{c.server}}
fn(c.server, tlsConn, h)
}
return
}
}
for {
w, err := c.readRequest()
if c.lr.N != c.server.initialLimitedReaderSize() {
c.setState(c.rwc, StateActive)
}
if err != nil {
if err == errTooLarge {
io.WriteString(c.rwc, "HTTP/1.1 413 Request Entity Too Large\r\n\r\n")
c.closeWriteAndWait()
break
} else if err == io.EOF {
break
} else if neterr, ok := err.(net.Error); ok && neterr.Timeout() {
break
}
io.WriteString(c.rwc, "HTTP/1.1 400 Bad Request\r\n\r\n")
break
}
req := w.req
if req.expectsContinue() {
if req.ProtoAtLeast(1, 1) && req.ContentLength != 0 {
req.Body = &expectContinueReader{readCloser: req.Body, resp: w}
}
req.Header.Del("Expect")
} else if req.Header.get("Expect") != "" {
w.sendExpectationFailed()
break
}
serverHandler{c.server}.ServeHTTP(w, w.req)
if c.hijacked() {
return
}
w.finishRequest()
if !w.shouldReuseConnection() {
if w.requestBodyLimitHit || w.closedRequestBodyEarly() {
c.closeWriteAndWait()
}
break
}
c.setState(c.rwc, StateIdle)
}
}
func (w *response) sendExpectationFailed() {
w.Header().Set("Connection", "close")
w.WriteHeader(StatusExpectationFailed)
w.finishRequest()
}
// Hijack implements the Hijacker.Hijack method. Our response is both a ResponseWriter
// and a Hijacker.
func (w *response) Hijack() (rwc net.Conn, buf *bufio.ReadWriter, err error) {
if w.wroteHeader {
w.cw.flush()
}
rwc, buf, err = w.conn.hijack()
if err == nil {
putBufioWriter(w.w)
w.w = nil
}
return rwc, buf, err
}
func (w *response) CloseNotify() <-chan bool {
return w.conn.closeNotify()
}
// The HandlerFunc type is an adapter to allow the use of
// ordinary functions as HTTP handlers. If f is a function
// with the appropriate signature, HandlerFunc(f) is a
// Handler object that calls f.
type HandlerFunc func(ResponseWriter, *Request)
// ServeHTTP calls f(w, r).
func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
f(w, r)
}
// Error replies to the request with the specified error message and HTTP code.
// The error message should be plain text.
func Error(w ResponseWriter, error string, code int) {
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
w.Header().Set("X-Content-Type-Options", "nosniff")
w.WriteHeader(code)
fmt.Fprintln(w, error)
}
// NotFound replies to the request with an HTTP 404 not found error.
func NotFound(w ResponseWriter, r *Request) { Error(w, "404 page not found", StatusNotFound) }
// NotFoundHandler returns a simple request handler
// that replies to each request with a ` + "`" + `` + "`" + `404 page not found'' reply.
func NotFoundHandler() Handler { return HandlerFunc(NotFound) }
// StripPrefix returns a handler that serves HTTP requests
// by removing the given prefix from the request URL's Path
// and invoking the handler h. StripPrefix handles a
// request for a path that doesn't begin with prefix by
// replying with an HTTP 404 not found error.
func StripPrefix(prefix string, h Handler) Handler {
if prefix == "" {
return h
}
return HandlerFunc(func(w ResponseWriter, r *Request) {
if p := strings.TrimPrefix(r.URL.Path, prefix); len(p) < len(r.URL.Path) {
r.URL.Path = p
h.ServeHTTP(w, r)
} else {
NotFound(w, r)
}
})
}
// Redirect replies to the request with a redirect to url,
// which may be a path relative to the request path.
func Redirect(w ResponseWriter, r *Request, urlStr string, code int) {
if u, err := url.Parse(urlStr); err == nil {
oldpath := r.URL.Path
if oldpath == "" {
oldpath = "/"
}
if u.Scheme == "" {
if urlStr == "" || urlStr[0] != '/' {
olddir, _ := path.Split(oldpath)
urlStr = olddir + urlStr
}
var query string
if i := strings.Index(urlStr, "?"); i != -1 {
urlStr, query = urlStr[:i], urlStr[i:]
}
trailing := strings.HasSuffix(urlStr, "/")
urlStr = path.Clean(urlStr)
if trailing && !strings.HasSuffix(urlStr, "/") {
urlStr += "/"
}
urlStr += query
}
}
w.Header().Set("Location", urlStr)
w.WriteHeader(code)
if r.Method == "GET" {
note := "<a href=\"" + htmlEscape(urlStr) + "\">" + statusText[code] + "</a>.\n"
fmt.Fprintln(w, note)
}
}
var htmlReplacer = strings.NewReplacer(
"&", "&amp;",
"<", "&lt;",
">", "&gt;",
` + "`" + `"` + "`" + `, "&#34;",
"'", "&#39;",
)
func htmlEscape(s string) string {
return htmlReplacer.Replace(s)
}
// Redirect to a fixed URL
type redirectHandler struct {
url string
code int
}
func (rh *redirectHandler) ServeHTTP(w ResponseWriter, r *Request) {
Redirect(w, r, rh.url, rh.code)
}
// RedirectHandler returns a request handler that redirects
// each request it receives to the given url using the given
// status code.
func RedirectHandler(url string, code int) Handler {
return &redirectHandler{url, code}
}
// ServeMux is an HTTP request multiplexer.
// It matches the URL of each incoming request against a list of registered
// patterns and calls the handler for the pattern that
// most closely matches the URL.
//
// Patterns name fixed, rooted paths, like "/favicon.ico",
// or rooted subtrees, like "/images/" (note the trailing slash).
// Longer patterns take precedence over shorter ones, so that
// if there are handlers registered for both "/images/"
// and "/images/thumbnails/", the latter handler will be
// called for paths beginning "/images/thumbnails/" and the
// former will receive requests for any other paths in the
// "/images/" subtree.
//
// Note that since a pattern ending in a slash names a rooted subtree,
// the pattern "/" matches all paths not matched by other registered
// patterns, not just the URL with Path == "/".
//
// Patterns may optionally begin with a host name, restricting matches to
// URLs on that host only. Host-specific patterns take precedence over
// general patterns, so that a handler might register for the two patterns
// "/codesearch" and "codesearch.google.com/" without also taking over
// requests for "http://www.google.com/".
//
// ServeMux also takes care of sanitizing the URL request path,
// redirecting any request containing . or .. elements to an
// equivalent .- and ..-free URL.
type ServeMux struct {
mu sync.RWMutex
m map[string]muxEntry
hosts bool // whether any patterns contain hostnames
}
type muxEntry struct {
explicit bool
h Handler
pattern string
}
// NewServeMux allocates and returns a new ServeMux.
func NewServeMux() *ServeMux { return &ServeMux{m: make(map[string]muxEntry)} }
// DefaultServeMux is the default ServeMux used by Serve.
var DefaultServeMux = NewServeMux()
// Does path match pattern?
func pathMatch(pattern, path string) bool {
if len(pattern) == 0 {
return false
}
n := len(pattern)
if pattern[n-1] != '/' {
return pattern == path
}
return len(path) >= n && path[0:n] == pattern
}
// Return the canonical path for p, eliminating . and .. elements.
func cleanPath(p string) string {
if p == "" {
return "/"
}
if p[0] != '/' {
p = "/" + p
}
np := path.Clean(p)
if p[len(p)-1] == '/' && np != "/" {
np += "/"
}
return np
}
// Find a handler on a handler map given a path string
// Most-specific (longest) pattern wins
func (mux *ServeMux) match(path string) (h Handler, pattern string) {
var n = 0
for k, v := range mux.m {
if !pathMatch(k, path) {
continue
}
if h == nil || len(k) > n {
n = len(k)
h = v.h
pattern = v.pattern
}
}
return
}
// Handler returns the handler to use for the given request,
// consulting r.Method, r.Host, and r.URL.Path. It always returns
// a non-nil handler. If the path is not in its canonical form, the
// handler will be an internally-generated handler that redirects
// to the canonical path.
//
// Handler also returns the registered pattern that matches the
// request or, in the case of internally-generated redirects,
// the pattern that will match after following the redirect.
//
// If there is no registered handler that applies to the request,
// Handler returns a ` + "`" + `` + "`" + `page not found'' handler and an empty pattern.
func (mux *ServeMux) Handler(r *Request) (h Handler, pattern string) {
if r.Method != "CONNECT" {
if p := cleanPath(r.URL.Path); p != r.URL.Path {
_, pattern = mux.handler(r.Host, p)
url := *r.URL
url.Path = p
return RedirectHandler(url.String(), StatusMovedPermanently), pattern
}
}
return mux.handler(r.Host, r.URL.Path)
}
// handler is the main implementation of Handler.
// The path is known to be in canonical form, except for CONNECT methods.
func (mux *ServeMux) handler(host, path string) (h Handler, pattern string) {
mux.mu.RLock()
defer mux.mu.RUnlock()
if mux.hosts {
h, pattern = mux.match(host + path)
}
if h == nil {
h, pattern = mux.match(path)
}
if h == nil {
h, pattern = NotFoundHandler(), ""
}
return
}
// ServeHTTP dispatches the request to the handler whose
// pattern most closely matches the request URL.
func (mux *ServeMux) ServeHTTP(w ResponseWriter, r *Request) {
if r.RequestURI == "*" {
if r.ProtoAtLeast(1, 1) {
w.Header().Set("Connection", "close")
}
w.WriteHeader(StatusBadRequest)
return
}
h, _ := mux.Handler(r)
h.ServeHTTP(w, r)
}
// Handle registers the handler for the given pattern.
// If a handler already exists for pattern, Handle panics.
func (mux *ServeMux) Handle(pattern string, handler Handler) {
mux.mu.Lock()
defer mux.mu.Unlock()
if pattern == "" {
panic("http: invalid pattern " + pattern)
}
if handler == nil {
panic("http: nil handler")
}
if mux.m[pattern].explicit {
panic("http: multiple registrations for " + pattern)
}
mux.m[pattern] = muxEntry{explicit: true, h: handler, pattern: pattern}
if pattern[0] != '/' {
mux.hosts = true
}
n := len(pattern)
if n > 0 && pattern[n-1] == '/' && !mux.m[pattern[0:n-1]].explicit {
path := pattern
if pattern[0] != '/' {
path = pattern[strings.Index(pattern, "/"):]
}
url := &url.URL{Path: path}
mux.m[pattern[0:n-1]] = muxEntry{h: RedirectHandler(url.String(), StatusMovedPermanently), pattern: pattern}
}
}
// HandleFunc registers the handler function for the given pattern.
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
mux.Handle(pattern, HandlerFunc(handler))
}
// Handle registers the handler for the given pattern
// in the DefaultServeMux.
// The documentation for ServeMux explains how patterns are matched.
func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, handler) }
// HandleFunc registers the handler function for the given pattern
// in the DefaultServeMux.
// The documentation for ServeMux explains how patterns are matched.
func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
DefaultServeMux.HandleFunc(pattern, handler)
}
// Serve accepts incoming HTTP connections on the listener l,
// creating a new service goroutine for each. The service goroutines
// read requests and then call handler to reply to them.
// Handler is typically nil, in which case the DefaultServeMux is used.
func Serve(l net.Listener, handler Handler) error {
srv := &Server{Handler: handler}
return srv.Serve(l)
}
// A Server defines parameters for running an HTTP server.
// The zero value for Server is a valid configuration.
type Server struct {
Addr string // TCP address to listen on, ":http" if empty
Handler Handler // handler to invoke, http.DefaultServeMux if nil
ReadTimeout time.Duration // maximum duration before timing out read of the request
WriteTimeout time.Duration // maximum duration before timing out write of the response
MaxHeaderBytes int // maximum size of request headers, DefaultMaxHeaderBytes if 0
TLSConfig *tls.Config // optional TLS config, used by ListenAndServeTLS
// TLSNextProto optionally specifies a function to take over
// ownership of the provided TLS connection when an NPN
// protocol upgrade has occurred. The map key is the protocol
// name negotiated. The Handler argument should be used to
// handle HTTP requests and will initialize the Request's TLS
// and RemoteAddr if not already set. The connection is
// automatically closed when the function returns.
TLSNextProto map[string]func(*Server, *tls.Conn, Handler)
// ConnState specifies an optional callback function that is
// called when a client connection changes state. See the
// ConnState type and associated constants for details.
ConnState func(net.Conn, ConnState)
// ErrorLog specifies an optional logger for errors accepting
// connections and unexpected behavior from handlers.
// If nil, logging goes to os.Stderr via the log package's
// standard logger.
ErrorLog *log.Logger
disableKeepAlives int32 // accessed atomically.
}
// A ConnState represents the state of a client connection to a server.
// It's used by the optional Server.ConnState hook.
type ConnState int
const (
// StateNew represents a new connection that is expected to
// send a request immediately. Connections begin at this
// state and then transition to either StateActive or
// StateClosed.
StateNew ConnState = iota
// StateActive represents a connection that has read 1 or more
// bytes of a request. The Server.ConnState hook for
// StateActive fires before the request has entered a handler
// and doesn't fire again until the request has been
// handled. After the request is handled, the state
// transitions to StateClosed, StateHijacked, or StateIdle.
StateActive
// StateIdle represents a connection that has finished
// handling a request and is in the keep-alive state, waiting
// for a new request. Connections transition from StateIdle
// to either StateActive or StateClosed.
StateIdle
// StateHijacked represents a hijacked connection.
// This is a terminal state. It does not transition to StateClosed.
StateHijacked
// StateClosed represents a closed connection.
// This is a terminal state. Hijacked connections do not
// transition to StateClosed.
StateClosed
)
var stateName = map[ConnState]string{
StateNew: "new",
StateActive: "active",
StateIdle: "idle",
StateHijacked: "hijacked",
StateClosed: "closed",
}
func (c ConnState) String() string {
return stateName[c]
}
// serverHandler delegates to either the server's Handler or
// DefaultServeMux and also handles "OPTIONS *" requests.
type serverHandler struct {
srv *Server
}
func (sh serverHandler) ServeHTTP(rw ResponseWriter, req *Request) {
handler := sh.srv.Handler
if handler == nil {
handler = DefaultServeMux
}
if req.RequestURI == "*" && req.Method == "OPTIONS" {
handler = globalOptionsHandler{}
}
handler.ServeHTTP(rw, req)
}
// ListenAndServe listens on the TCP network address srv.Addr and then
// calls Serve to handle requests on incoming connections. If
// srv.Addr is blank, ":http" is used.
func (srv *Server) ListenAndServe() error {
addr := srv.Addr
if addr == "" {
addr = ":http"
}
ln, err := net.Listen("tcp", addr)
if err != nil {
return err
}
return srv.Serve(tcpKeepAliveListener{ln.(*net.TCPListener)})
}
// Serve accepts incoming connections on the Listener l, creating a
// new service goroutine for each. The service goroutines read requests and
// then call srv.Handler to reply to them.
func (srv *Server) Serve(l net.Listener) error {
defer l.Close()
var tempDelay time.Duration // how long to sleep on accept failure
for {
rw, e := l.Accept()
if e != nil {
if ne, ok := e.(net.Error); ok && ne.Temporary() {
if tempDelay == 0 {
tempDelay = 5 * time.Millisecond
} else {
tempDelay *= 2
}
if max := 1 * time.Second; tempDelay > max {
tempDelay = max
}
srv.logf("http: Accept error: %v; retrying in %v", e, tempDelay)
time.Sleep(tempDelay)
continue
}
return e
}
tempDelay = 0
c, err := srv.newConn(rw)
if err != nil {
continue
}
c.setState(c.rwc, StateNew)
go c.serve()
}
}
func (s *Server) doKeepAlives() bool {
return atomic.LoadInt32(&s.disableKeepAlives) == 0
}
// SetKeepAlivesEnabled controls whether HTTP keep-alives are enabled.
// By default, keep-alives are always enabled. Only very
// resource-constrained environments or servers in the process of
// shutting down should disable them.
func (srv *Server) SetKeepAlivesEnabled(v bool) {
if v {
atomic.StoreInt32(&srv.disableKeepAlives, 0)
} else {
atomic.StoreInt32(&srv.disableKeepAlives, 1)
}
}
func (s *Server) logf(format string, args ...interface{}) {
if s.ErrorLog != nil {
s.ErrorLog.Printf(format, args...)
} else {
log.Printf(format, args...)
}
}
// ListenAndServe listens on the TCP network address addr
// and then calls Serve with handler to handle requests
// on incoming connections. Handler is typically nil,
// in which case the DefaultServeMux is used.
//
// A trivial example server is:
//
// package main
//
// import (
// "io"
// "net/http"
// "log"
// )
//
// // hello world, the web server
// func HelloServer(w http.ResponseWriter, req *http.Request) {
// io.WriteString(w, "hello, world!\n")
// }
//
// func main() {
// http.HandleFunc("/hello", HelloServer)
// err := http.ListenAndServe(":12345", nil)
// if err != nil {
// log.Fatal("ListenAndServe: ", err)
// }
// }
func ListenAndServe(addr string, handler Handler) error {
server := &Server{Addr: addr, Handler: handler}
return server.ListenAndServe()
}
// ListenAndServeTLS acts identically to ListenAndServe, except that it
// expects HTTPS connections. Additionally, files containing a certificate and
// matching private key for the server must be provided. If the certificate
// is signed by a certificate authority, the certFile should be the concatenation
// of the server's certificate, any intermediates, and the CA's certificate.
//
// A trivial example server is:
//
// import (
// "log"
// "net/http"
// )
//
// func handler(w http.ResponseWriter, req *http.Request) {
// w.Header().Set("Content-Type", "text/plain")
// w.Write([]byte("This is an example server.\n"))
// }
//
// func main() {
// http.HandleFunc("/", handler)
// log.Printf("About to listen on 10443. Go to https://127.0.0.1:10443/")
// err := http.ListenAndServeTLS(":10443", "cert.pem", "key.pem", nil)
// if err != nil {
// log.Fatal(err)
// }
// }
//
// One can use generate_cert.go in crypto/tls to generate cert.pem and key.pem.
func ListenAndServeTLS(addr string, certFile string, keyFile string, handler Handler) error {
server := &Server{Addr: addr, Handler: handler}
return server.ListenAndServeTLS(certFile, keyFile)
}
// ListenAndServeTLS listens on the TCP network address srv.Addr and
// then calls Serve to handle requests on incoming TLS connections.
//
// Filenames containing a certificate and matching private key for the
// server must be provided if the Server's TLSConfig.Certificates is
// not populated. If the certificate is signed by a certificate
// authority, the certFile should be the concatenation of the server's
// certificate, any intermediates, and the CA's certificate.
//
// If srv.Addr is blank, ":https" is used.
func (srv *Server) ListenAndServeTLS(certFile, keyFile string) error {
addr := srv.Addr
if addr == "" {
addr = ":https"
}
config := cloneTLSConfig(srv.TLSConfig)
if config.NextProtos == nil {
config.NextProtos = []string{"http/1.1"}
}
if len(config.Certificates) == 0 || certFile != "" || keyFile != "" {
var err error
config.Certificates = make([]tls.Certificate, 1)
config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile)
if err != nil {
return err
}
}
ln, err := net.Listen("tcp", addr)
if err != nil {
return err
}
tlsListener := tls.NewListener(tcpKeepAliveListener{ln.(*net.TCPListener)}, config)
return srv.Serve(tlsListener)
}
// TimeoutHandler returns a Handler that runs h with the given time limit.
//
// The new Handler calls h.ServeHTTP to handle each request, but if a
// call runs for longer than its time limit, the handler responds with
// a 503 Service Unavailable error and the given message in its body.
// (If msg is empty, a suitable default message will be sent.)
// After such a timeout, writes by h to its ResponseWriter will return
// ErrHandlerTimeout.
func TimeoutHandler(h Handler, dt time.Duration, msg string) Handler {
f := func() <-chan time.Time {
return time.After(dt)
}
return &timeoutHandler{h, f, msg}
}
// ErrHandlerTimeout is returned on ResponseWriter Write calls
// in handlers which have timed out.
var ErrHandlerTimeout = errors.New("http: Handler timeout")
type timeoutHandler struct {
handler Handler
timeout func() <-chan time.Time // returns channel producing a timeout
body string
}
func (h *timeoutHandler) errorBody() string {
if h.body != "" {
return h.body
}
return "<html><head><title>Timeout</title></head><body><h1>Timeout</h1></body></html>"
}
func (h *timeoutHandler) ServeHTTP(w ResponseWriter, r *Request) {
done := make(chan bool, 1)
tw := &timeoutWriter{w: w}
go func() {
h.handler.ServeHTTP(tw, r)
done <- true
}()
select {
case <-done:
return
case <-h.timeout():
tw.mu.Lock()
defer tw.mu.Unlock()
if !tw.wroteHeader {
tw.w.WriteHeader(StatusServiceUnavailable)
tw.w.Write([]byte(h.errorBody()))
}
tw.timedOut = true
}
}
type timeoutWriter struct {
w ResponseWriter
mu sync.Mutex
timedOut bool
wroteHeader bool
}
func (tw *timeoutWriter) Header() Header {
return tw.w.Header()
}
func (tw *timeoutWriter) Write(p []byte) (int, error) {
tw.mu.Lock()
defer tw.mu.Unlock()
tw.wroteHeader = true
if tw.timedOut {
return 0, ErrHandlerTimeout
}
return tw.w.Write(p)
}
func (tw *timeoutWriter) WriteHeader(code int) {
tw.mu.Lock()
defer tw.mu.Unlock()
if tw.timedOut || tw.wroteHeader {
return
}
tw.wroteHeader = true
tw.w.WriteHeader(code)
}
// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
// connections. It's used by ListenAndServe and ListenAndServeTLS so
// dead TCP connections (e.g. closing laptop mid-download) eventually
// go away.
type tcpKeepAliveListener struct {
*net.TCPListener
}
func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
tc, err := ln.AcceptTCP()
if err != nil {
return
}
tc.SetKeepAlive(true)
tc.SetKeepAlivePeriod(3 * time.Minute)
return tc, nil
}
// globalOptionsHandler responds to "OPTIONS *" requests.
type globalOptionsHandler struct{}
func (globalOptionsHandler) ServeHTTP(w ResponseWriter, r *Request) {
w.Header().Set("Content-Length", "0")
if r.ContentLength != 0 {
mb := MaxBytesReader(w, r.Body, 4<<10)
io.Copy(ioutil.Discard, mb)
}
}
type eofReaderWithWriteTo struct{}
func (eofReaderWithWriteTo) WriteTo(io.Writer) (int64, error) { return 0, nil }
func (eofReaderWithWriteTo) Read([]byte) (int, error) { return 0, io.EOF }
// eofReader is a non-nil io.ReadCloser that always returns EOF.
// It has a WriteTo method so io.Copy won't need a buffer.
var eofReader = &struct {
eofReaderWithWriteTo
io.Closer
}{
eofReaderWithWriteTo{},
ioutil.NopCloser(nil),
}
// Verify that an io.Copy from an eofReader won't require a buffer.
var _ io.WriterTo = eofReader
// initNPNRequest is an HTTP handler that initializes certain
// uninitialized fields in its *Request. Such partially-initialized
// Requests come from NPN protocol handlers.
type initNPNRequest struct {
c *tls.Conn
h serverHandler
}
func (h initNPNRequest) ServeHTTP(rw ResponseWriter, req *Request) {
if req.TLS == nil {
req.TLS = &tls.ConnectionState{}
*req.TLS = h.c.ConnectionState()
}
if req.Body == nil {
req.Body = eofReader
}
if req.RemoteAddr == "" {
req.RemoteAddr = h.c.RemoteAddr().String()
}
h.h.ServeHTTP(rw, req)
}
// loggingConn is used for debugging.
type loggingConn struct {
name string
net.Conn
}
var (
uniqNameMu sync.Mutex
uniqNameNext = make(map[string]int)
)
func newLoggingConn(baseName string, c net.Conn) net.Conn {
uniqNameMu.Lock()
defer uniqNameMu.Unlock()
uniqNameNext[baseName]++
return &loggingConn{
name: fmt.Sprintf("%s-%d", baseName, uniqNameNext[baseName]),
Conn: c,
}
}
func (c *loggingConn) Write(p []byte) (n int, err error) {
log.Printf("%s.Write(%d) = ....", c.name, len(p))
n, err = c.Conn.Write(p)
log.Printf("%s.Write(%d) = %d, %v", c.name, len(p), n, err)
return
}
func (c *loggingConn) Read(p []byte) (n int, err error) {
log.Printf("%s.Read(%d) = ....", c.name, len(p))
n, err = c.Conn.Read(p)
log.Printf("%s.Read(%d) = %d, %v", c.name, len(p), n, err)
return
}
func (c *loggingConn) Close() (err error) {
log.Printf("%s.Close() = ...", c.name)
err = c.Conn.Close()
log.Printf("%s.Close() = %v", c.name, err)
return
}
// checkConnErrorWriter writes to c.rwc and records any write errors to c.werr.
// It only contains one field (and a pointer field at that), so it
// fits in an interface value without an extra allocation.
type checkConnErrorWriter struct {
c *conn
}
func (w checkConnErrorWriter) Write(p []byte) (n int, err error) {
n, err = w.c.w.Write(p)
if err != nil && w.c.werr == nil {
w.c.werr = err
}
return
}
func numLeadingCRorLF(v []byte) (n int) {
for _, b := range v {
if b == '\r' || b == '\n' {
n++
continue
}
break
}
return
}
// The algorithm uses at most sniffLen bytes to make its decision.
const sniffLen = 512
// DetectContentType implements the algorithm described
// at http://mimesniff.spec.whatwg.org/ to determine the
// Content-Type of the given data. It considers at most the
// first 512 bytes of data. DetectContentType always returns
// a valid MIME type: if it cannot determine a more specific one, it
// returns "application/octet-stream".
func DetectContentType(data []byte) string {
if len(data) > sniffLen {
data = data[:sniffLen]
}
firstNonWS := 0
for ; firstNonWS < len(data) && isWS(data[firstNonWS]); firstNonWS++ {
}
for _, sig := range sniffSignatures {
if ct := sig.match(data, firstNonWS); ct != "" {
return ct
}
}
return "application/octet-stream"
}
func isWS(b byte) bool {
switch b {
case '\t', '\n', '\x0c', '\r', ' ':
return true
}
return false
}
type sniffSig interface {
// match returns the MIME type of the data, or "" if unknown.
match(data []byte, firstNonWS int) string
}
// Data matching the table in section 6.
var sniffSignatures = []sniffSig{
htmlSig("<!DOCTYPE HTML"),
htmlSig("<HTML"),
htmlSig("<HEAD"),
htmlSig("<SCRIPT"),
htmlSig("<IFRAME"),
htmlSig("<H1"),
htmlSig("<DIV"),
htmlSig("<FONT"),
htmlSig("<TABLE"),
htmlSig("<A"),
htmlSig("<STYLE"),
htmlSig("<TITLE"),
htmlSig("<B"),
htmlSig("<BODY"),
htmlSig("<BR"),
htmlSig("<P"),
htmlSig("<!--"),
&maskedSig{mask: []byte("\xFF\xFF\xFF\xFF\xFF"), pat: []byte("<?xml"), skipWS: true, ct: "text/xml; charset=utf-8"},
&exactSig{[]byte("%PDF-"), "application/pdf"},
&exactSig{[]byte("%!PS-Adobe-"), "application/postscript"},
&maskedSig{mask: []byte("\xFF\xFF\x00\x00"), pat: []byte("\xFE\xFF\x00\x00"), ct: "text/plain; charset=utf-16be"},
&maskedSig{mask: []byte("\xFF\xFF\x00\x00"), pat: []byte("\xFF\xFE\x00\x00"), ct: "text/plain; charset=utf-16le"},
&maskedSig{mask: []byte("\xFF\xFF\xFF\x00"), pat: []byte("\xEF\xBB\xBF\x00"), ct: "text/plain; charset=utf-8"},
&exactSig{[]byte("GIF87a"), "image/gif"},
&exactSig{[]byte("GIF89a"), "image/gif"},
&exactSig{[]byte("\x89\x50\x4E\x47\x0D\x0A\x1A\x0A"), "image/png"},
&exactSig{[]byte("\xFF\xD8\xFF"), "image/jpeg"},
&exactSig{[]byte("BM"), "image/bmp"},
&maskedSig{
mask: []byte("\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF\xFF\xFF"),
pat: []byte("RIFF\x00\x00\x00\x00WEBPVP"),
ct: "image/webp",
},
&exactSig{[]byte("\x00\x00\x01\x00"), "image/vnd.microsoft.icon"},
&exactSig{[]byte("\x4F\x67\x67\x53\x00"), "application/ogg"},
&maskedSig{
mask: []byte("\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF"),
pat: []byte("RIFF\x00\x00\x00\x00WAVE"),
ct: "audio/wave",
},
&exactSig{[]byte("\x1A\x45\xDF\xA3"), "video/webm"},
&exactSig{[]byte("\x52\x61\x72\x20\x1A\x07\x00"), "application/x-rar-compressed"},
&exactSig{[]byte("\x50\x4B\x03\x04"), "application/zip"},
&exactSig{[]byte("\x1F\x8B\x08"), "application/x-gzip"},
textSig(0),
}
type exactSig struct {
sig []byte
ct string
}
func (e *exactSig) match(data []byte, firstNonWS int) string {
if bytes.HasPrefix(data, e.sig) {
return e.ct
}
return ""
}
type maskedSig struct {
mask, pat []byte
skipWS bool
ct string
}
func (m *maskedSig) match(data []byte, firstNonWS int) string {
if m.skipWS {
data = data[firstNonWS:]
}
if len(data) < len(m.mask) {
return ""
}
for i, mask := range m.mask {
db := data[i] & mask
if db != m.pat[i] {
return ""
}
}
return m.ct
}
type htmlSig []byte
func (h htmlSig) match(data []byte, firstNonWS int) string {
data = data[firstNonWS:]
if len(data) < len(h)+1 {
return ""
}
for i, b := range h {
db := data[i]
if 'A' <= b && b <= 'Z' {
db &= 0xDF
}
if b != db {
return ""
}
}
if db := data[len(h)]; db != ' ' && db != '>' {
return ""
}
return "text/html; charset=utf-8"
}
var mp4ftype = []byte("ftyp")
type mp4Sig int
func (mp4Sig) match(data []byte, firstNonWS int) string {
if len(data) < 8 {
return ""
}
boxSize := int(binary.BigEndian.Uint32(data[:4]))
if boxSize%4 != 0 || len(data) < boxSize {
return ""
}
if !bytes.Equal(data[4:8], mp4ftype) {
return ""
}
for st := 8; st < boxSize; st += 4 {
if st == 12 {
continue
}
seg := string(data[st : st+3])
switch seg {
case "mp4", "iso", "M4V", "M4P", "M4B":
return "video/mp4"
}
}
return ""
}
type textSig int
func (textSig) match(data []byte, firstNonWS int) string {
for _, b := range data[firstNonWS:] {
switch {
case 0x00 <= b && b <= 0x08,
b == 0x0B,
0x0E <= b && b <= 0x1A,
0x1C <= b && b <= 0x1F:
return ""
}
}
return "text/plain; charset=utf-8"
}
// HTTP status codes, defined in RFC 2616.
const (
StatusContinue = 100
StatusSwitchingProtocols = 101
StatusOK = 200
StatusCreated = 201
StatusAccepted = 202
StatusNonAuthoritativeInfo = 203
StatusNoContent = 204
StatusResetContent = 205
StatusPartialContent = 206
StatusMultipleChoices = 300
StatusMovedPermanently = 301
StatusFound = 302
StatusSeeOther = 303
StatusNotModified = 304
StatusUseProxy = 305
StatusTemporaryRedirect = 307
StatusBadRequest = 400
StatusUnauthorized = 401
StatusPaymentRequired = 402
StatusForbidden = 403
StatusNotFound = 404
StatusMethodNotAllowed = 405
StatusNotAcceptable = 406
StatusProxyAuthRequired = 407
StatusRequestTimeout = 408
StatusConflict = 409
StatusGone = 410
StatusLengthRequired = 411
StatusPreconditionFailed = 412
StatusRequestEntityTooLarge = 413
StatusRequestURITooLong = 414
StatusUnsupportedMediaType = 415
StatusRequestedRangeNotSatisfiable = 416
StatusExpectationFailed = 417
StatusTeapot = 418
StatusInternalServerError = 500
StatusNotImplemented = 501
StatusBadGateway = 502
StatusServiceUnavailable = 503
StatusGatewayTimeout = 504
StatusHTTPVersionNotSupported = 505
// New HTTP status codes from RFC 6585. Not exported yet in Go 1.1.
// See discussion at https://codereview.appspot.com/7678043/
statusPreconditionRequired = 428
statusTooManyRequests = 429
statusRequestHeaderFieldsTooLarge = 431
statusNetworkAuthenticationRequired = 511
)
var statusText = map[int]string{
StatusContinue: "Continue",
StatusSwitchingProtocols: "Switching Protocols",
StatusOK: "OK",
StatusCreated: "Created",
StatusAccepted: "Accepted",
StatusNonAuthoritativeInfo: "Non-Authoritative Information",
StatusNoContent: "No Content",
StatusResetContent: "Reset Content",
StatusPartialContent: "Partial Content",
StatusMultipleChoices: "Multiple Choices",
StatusMovedPermanently: "Moved Permanently",
StatusFound: "Found",
StatusSeeOther: "See Other",
StatusNotModified: "Not Modified",
StatusUseProxy: "Use Proxy",
StatusTemporaryRedirect: "Temporary Redirect",
StatusBadRequest: "Bad Request",
StatusUnauthorized: "Unauthorized",
StatusPaymentRequired: "Payment Required",
StatusForbidden: "Forbidden",
StatusNotFound: "Not Found",
StatusMethodNotAllowed: "Method Not Allowed",
StatusNotAcceptable: "Not Acceptable",
StatusProxyAuthRequired: "Proxy Authentication Required",
StatusRequestTimeout: "Request Timeout",
StatusConflict: "Conflict",
StatusGone: "Gone",
StatusLengthRequired: "Length Required",
StatusPreconditionFailed: "Precondition Failed",
StatusRequestEntityTooLarge: "Request Entity Too Large",
StatusRequestURITooLong: "Request URI Too Long",
StatusUnsupportedMediaType: "Unsupported Media Type",
StatusRequestedRangeNotSatisfiable: "Requested Range Not Satisfiable",
StatusExpectationFailed: "Expectation Failed",
StatusTeapot: "I'm a teapot",
StatusInternalServerError: "Internal Server Error",
StatusNotImplemented: "Not Implemented",
StatusBadGateway: "Bad Gateway",
StatusServiceUnavailable: "Service Unavailable",
StatusGatewayTimeout: "Gateway Timeout",
StatusHTTPVersionNotSupported: "HTTP Version Not Supported",
statusPreconditionRequired: "Precondition Required",
statusTooManyRequests: "Too Many Requests",
statusRequestHeaderFieldsTooLarge: "Request Header Fields Too Large",
statusNetworkAuthenticationRequired: "Network Authentication Required",
}
// StatusText returns a text for the HTTP status code. It returns the empty
// string if the code is unknown.
func StatusText(code int) string {
return statusText[code]
}
// ErrLineTooLong is returned when reading request or response bodies
// with malformed chunked encoding.
var ErrLineTooLong = internal.ErrLineTooLong
type errorReader struct {
err error
}
func (r errorReader) Read(p []byte) (n int, err error) {
return 0, r.err
}
// transferWriter inspects the fields of a user-supplied Request or Response,
// sanitizes them without changing the user object and provides methods for
// writing the respective header, body and trailer in wire format.
type transferWriter struct {
Method string
Body io.Reader
BodyCloser io.Closer
ResponseToHEAD bool
ContentLength int64 // -1 means unknown, 0 means exactly none
Close bool
TransferEncoding []string
Trailer Header
IsResponse bool
}
func newTransferWriter(r interface{}) (t *transferWriter, err error) {
t = &transferWriter{}
atLeastHTTP11 := false
switch rr := r.(type) {
case *Request:
if rr.ContentLength != 0 && rr.Body == nil {
return nil, fmt.Errorf("http: Request.ContentLength=%d with nil Body", rr.ContentLength)
}
t.Method = rr.Method
t.Body = rr.Body
t.BodyCloser = rr.Body
t.ContentLength = rr.ContentLength
t.Close = rr.Close
t.TransferEncoding = rr.TransferEncoding
t.Trailer = rr.Trailer
atLeastHTTP11 = rr.ProtoAtLeast(1, 1)
if t.Body != nil && len(t.TransferEncoding) == 0 && atLeastHTTP11 {
if t.ContentLength == 0 {
// Test to see if it's actually zero or just unset.
var buf [1]byte
n, rerr := io.ReadFull(t.Body, buf[:])
if rerr != nil && rerr != io.EOF {
t.ContentLength = -1
t.Body = errorReader{rerr}
} else if n == 1 {
t.ContentLength = -1
t.Body = io.MultiReader(bytes.NewReader(buf[:]), t.Body)
} else {
t.Body = nil
t.BodyCloser = nil
}
}
if t.ContentLength < 0 {
t.TransferEncoding = []string{"chunked"}
}
}
case *Response:
t.IsResponse = true
if rr.Request != nil {
t.Method = rr.Request.Method
}
t.Body = rr.Body
t.BodyCloser = rr.Body
t.ContentLength = rr.ContentLength
t.Close = rr.Close
t.TransferEncoding = rr.TransferEncoding
t.Trailer = rr.Trailer
atLeastHTTP11 = rr.ProtoAtLeast(1, 1)
t.ResponseToHEAD = noBodyExpected(t.Method)
}
if t.ResponseToHEAD {
t.Body = nil
if chunked(t.TransferEncoding) {
t.ContentLength = -1
}
} else {
if !atLeastHTTP11 || t.Body == nil {
t.TransferEncoding = nil
}
if chunked(t.TransferEncoding) {
t.ContentLength = -1
} else if t.Body == nil {
t.ContentLength = 0
}
}
if !chunked(t.TransferEncoding) {
t.Trailer = nil
}
return t, nil
}
func noBodyExpected(requestMethod string) bool {
return requestMethod == "HEAD"
}
func (t *transferWriter) shouldSendContentLength() bool {
if chunked(t.TransferEncoding) {
return false
}
if t.ContentLength > 0 {
return true
}
if t.ContentLength < 0 {
return false
}
if t.Method == "POST" || t.Method == "PUT" {
return true
}
if t.ContentLength == 0 && isIdentity(t.TransferEncoding) {
if t.Method == "GET" || t.Method == "HEAD" {
return false
}
return true
}
return false
}
func (t *transferWriter) WriteHeader(w io.Writer) error {
if t.Close {
if _, err := io.WriteString(w, "Connection: close\r\n"); err != nil {
return err
}
}
if t.shouldSendContentLength() {
if _, err := io.WriteString(w, "Content-Length: "); err != nil {
return err
}
if _, err := io.WriteString(w, strconv.FormatInt(t.ContentLength, 10)+"\r\n"); err != nil {
return err
}
} else if chunked(t.TransferEncoding) {
if _, err := io.WriteString(w, "Transfer-Encoding: chunked\r\n"); err != nil {
return err
}
}
if t.Trailer != nil {
keys := make([]string, 0, len(t.Trailer))
for k := range t.Trailer {
k = CanonicalHeaderKey(k)
switch k {
case "Transfer-Encoding", "Trailer", "Content-Length":
return &badStringError{"invalid Trailer key", k}
}
keys = append(keys, k)
}
if len(keys) > 0 {
sort.Strings(keys)
if _, err := io.WriteString(w, "Trailer: "+strings.Join(keys, ",")+"\r\n"); err != nil {
return err
}
}
}
return nil
}
func (t *transferWriter) WriteBody(w io.Writer) error {
var err error
var ncopy int64
if t.Body != nil {
if chunked(t.TransferEncoding) {
if bw, ok := w.(*bufio.Writer); ok && !t.IsResponse {
w = &internal.FlushAfterChunkWriter{bw}
}
cw := internal.NewChunkedWriter(w)
_, err = io.Copy(cw, t.Body)
if err == nil {
err = cw.Close()
}
} else if t.ContentLength == -1 {
ncopy, err = io.Copy(w, t.Body)
} else {
ncopy, err = io.Copy(w, io.LimitReader(t.Body, t.ContentLength))
if err != nil {
return err
}
var nextra int64
nextra, err = io.Copy(ioutil.Discard, t.Body)
ncopy += nextra
}
if err != nil {
return err
}
if err = t.BodyCloser.Close(); err != nil {
return err
}
}
if !t.ResponseToHEAD && t.ContentLength != -1 && t.ContentLength != ncopy {
return fmt.Errorf("http: ContentLength=%d with Body length %d",
t.ContentLength, ncopy)
}
if chunked(t.TransferEncoding) {
if t.Trailer != nil {
if err := t.Trailer.Write(w); err != nil {
return err
}
}
_, err = io.WriteString(w, "\r\n")
}
return err
}
type transferReader struct {
// Input
Header Header
StatusCode int
RequestMethod string
ProtoMajor int
ProtoMinor int
// Output
Body io.ReadCloser
ContentLength int64
TransferEncoding []string
Close bool
Trailer Header
}
// bodyAllowedForStatus reports whether a given response status code
// permits a body. See RFC2616, section 4.4.
func bodyAllowedForStatus(status int) bool {
switch {
case status >= 100 && status <= 199:
return false
case status == 204:
return false
case status == 304:
return false
}
return true
}
var (
suppressedHeaders304 = []string{"Content-Type", "Content-Length", "Transfer-Encoding"}
suppressedHeadersNoBody = []string{"Content-Length", "Transfer-Encoding"}
)
func suppressedHeaders(status int) []string {
switch {
case status == 304:
return suppressedHeaders304
case !bodyAllowedForStatus(status):
return suppressedHeadersNoBody
}
return nil
}
// msg is *Request or *Response.
func readTransfer(msg interface{}, r *bufio.Reader) (err error) {
t := &transferReader{RequestMethod: "GET"}
isResponse := false
switch rr := msg.(type) {
case *Response:
t.Header = rr.Header
t.StatusCode = rr.StatusCode
t.ProtoMajor = rr.ProtoMajor
t.ProtoMinor = rr.ProtoMinor
t.Close = shouldClose(t.ProtoMajor, t.ProtoMinor, t.Header, true)
isResponse = true
if rr.Request != nil {
t.RequestMethod = rr.Request.Method
}
case *Request:
t.Header = rr.Header
t.RequestMethod = rr.Method
t.ProtoMajor = rr.ProtoMajor
t.ProtoMinor = rr.ProtoMinor
t.StatusCode = 200
t.Close = rr.Close
default:
panic("unexpected type")
}
if t.ProtoMajor == 0 && t.ProtoMinor == 0 {
t.ProtoMajor, t.ProtoMinor = 1, 1
}
t.TransferEncoding, err = fixTransferEncoding(isResponse, t.RequestMethod, t.Header)
if err != nil {
return err
}
realLength, err := fixLength(isResponse, t.StatusCode, t.RequestMethod, t.Header, t.TransferEncoding)
if err != nil {
return err
}
if isResponse && t.RequestMethod == "HEAD" {
if n, err := parseContentLength(t.Header.get("Content-Length")); err != nil {
return err
} else {
t.ContentLength = n
}
} else {
t.ContentLength = realLength
}
t.Trailer, err = fixTrailer(t.Header, t.TransferEncoding)
if err != nil {
return err
}
switch msg.(type) {
case *Response:
if realLength == -1 &&
!chunked(t.TransferEncoding) &&
bodyAllowedForStatus(t.StatusCode) {
t.Close = true
}
}
switch {
case chunked(t.TransferEncoding):
if noBodyExpected(t.RequestMethod) {
t.Body = eofReader
} else {
t.Body = &body{src: internal.NewChunkedReader(r), hdr: msg, r: r, closing: t.Close}
}
case realLength == 0:
t.Body = eofReader
case realLength > 0:
t.Body = &body{src: io.LimitReader(r, realLength), closing: t.Close}
default:
if t.Close {
t.Body = &body{src: r, closing: t.Close}
} else {
t.Body = eofReader
}
}
switch rr := msg.(type) {
case *Request:
rr.Body = t.Body
rr.ContentLength = t.ContentLength
rr.TransferEncoding = t.TransferEncoding
rr.Close = t.Close
rr.Trailer = t.Trailer
case *Response:
rr.Body = t.Body
rr.ContentLength = t.ContentLength
rr.TransferEncoding = t.TransferEncoding
rr.Close = t.Close
rr.Trailer = t.Trailer
}
return nil
}
// Checks whether chunked is part of the encodings stack
func chunked(te []string) bool { return len(te) > 0 && te[0] == "chunked" }
// Checks whether the encoding is explicitly "identity".
func isIdentity(te []string) bool { return len(te) == 1 && te[0] == "identity" }
// Sanitize transfer encoding
func fixTransferEncoding(isResponse bool, requestMethod string, header Header) ([]string, error) {
raw, present := header["Transfer-Encoding"]
if !present {
return nil, nil
}
delete(header, "Transfer-Encoding")
encodings := strings.Split(raw[0], ",")
te := make([]string, 0, len(encodings))
for _, encoding := range encodings {
encoding = strings.ToLower(strings.TrimSpace(encoding))
if encoding == "identity" {
break
}
if encoding != "chunked" {
return nil, &badStringError{"unsupported transfer encoding", encoding}
}
te = te[0 : len(te)+1]
te[len(te)-1] = encoding
}
if len(te) > 1 {
return nil, &badStringError{"too many transfer encodings", strings.Join(te, ",")}
}
if len(te) > 0 {
delete(header, "Content-Length")
return te, nil
}
return nil, nil
}
// Determine the expected body length, using RFC 2616 Section 4.4. This
// function is not a method, because ultimately it should be shared by
// ReadResponse and ReadRequest.
func fixLength(isResponse bool, status int, requestMethod string, header Header, te []string) (int64, error) {
contentLens := header["Content-Length"]
isRequest := !isResponse
if noBodyExpected(requestMethod) {
if isRequest && len(contentLens) > 0 && !(len(contentLens) == 1 && contentLens[0] == "0") {
return 0, fmt.Errorf("http: method cannot contain a Content-Length; got %q", contentLens)
}
return 0, nil
}
if status/100 == 1 {
return 0, nil
}
switch status {
case 204, 304:
return 0, nil
}
if len(contentLens) > 1 {
return 0, errors.New("http: message cannot contain multiple Content-Length headers")
}
if chunked(te) {
return -1, nil
}
// Logic based on Content-Length
var cl string
if len(contentLens) == 1 {
cl = strings.TrimSpace(contentLens[0])
}
if cl != "" {
n, err := parseContentLength(cl)
if err != nil {
return -1, err
}
return n, nil
} else {
header.Del("Content-Length")
}
if !isResponse {
return 0, nil
}
return -1, nil
}
// Determine whether to hang up after sending a request and body, or
// receiving a response and body
// 'header' is the request headers
func shouldClose(major, minor int, header Header, removeCloseHeader bool) bool {
if major < 1 {
return true
} else if major == 1 && minor == 0 {
vv := header["Connection"]
if headerValuesContainsToken(vv, "close") || !headerValuesContainsToken(vv, "keep-alive") {
return true
}
return false
} else {
if headerValuesContainsToken(header["Connection"], "close") {
if removeCloseHeader {
header.Del("Connection")
}
return true
}
}
return false
}
// Parse the trailer header
func fixTrailer(header Header, te []string) (Header, error) {
raw := header.get("Trailer")
if raw == "" {
return nil, nil
}
header.Del("Trailer")
trailer := make(Header)
keys := strings.Split(raw, ",")
for _, key := range keys {
key = CanonicalHeaderKey(strings.TrimSpace(key))
switch key {
case "Transfer-Encoding", "Trailer", "Content-Length":
return nil, &badStringError{"bad trailer key", key}
}
trailer[key] = nil
}
if len(trailer) == 0 {
return nil, nil
}
if !chunked(te) {
return nil, ErrUnexpectedTrailer
}
return trailer, nil
}
// body turns a Reader into a ReadCloser.
// Close ensures that the body has been fully read
// and then reads the trailer if necessary.
type body struct {
src io.Reader
hdr interface{} // non-nil (Response or Request) value means read trailer
r *bufio.Reader // underlying wire-format reader for the trailer
closing bool // is the connection to be closed after reading body?
doEarlyClose bool // whether Close should stop early
mu sync.Mutex // guards closed, and calls to Read and Close
sawEOF bool
closed bool
earlyClose bool // Close called and we didn't read to the end of src
}
// ErrBodyReadAfterClose is returned when reading a Request or Response
// Body after the body has been closed. This typically happens when the body is
// read after an HTTP Handler calls WriteHeader or Write on its
// ResponseWriter.
var ErrBodyReadAfterClose = errors.New("http: invalid Read on closed Body")
func (b *body) Read(p []byte) (n int, err error) {
b.mu.Lock()
defer b.mu.Unlock()
if b.closed {
return 0, ErrBodyReadAfterClose
}
return b.readLocked(p)
}
// Must hold b.mu.
func (b *body) readLocked(p []byte) (n int, err error) {
if b.sawEOF {
return 0, io.EOF
}
n, err = b.src.Read(p)
if err == io.EOF {
b.sawEOF = true
if b.hdr != nil {
if e := b.readTrailer(); e != nil {
err = e
b.sawEOF = false
b.closed = true
}
b.hdr = nil
} else {
if lr, ok := b.src.(*io.LimitedReader); ok && lr.N > 0 {
err = io.ErrUnexpectedEOF
}
}
}
if err == nil && n > 0 {
if lr, ok := b.src.(*io.LimitedReader); ok && lr.N == 0 {
err = io.EOF
b.sawEOF = true
}
}
return n, err
}
var (
singleCRLF = []byte("\r\n")
doubleCRLF = []byte("\r\n\r\n")
)
func seeUpcomingDoubleCRLF(r *bufio.Reader) bool {
for peekSize := 4; ; peekSize++ {
buf, err := r.Peek(peekSize)
if bytes.HasSuffix(buf, doubleCRLF) {
return true
}
if err != nil {
break
}
}
return false
}
var errTrailerEOF = errors.New("http: unexpected EOF reading trailer")
func (b *body) readTrailer() error {
buf, err := b.r.Peek(2)
if bytes.Equal(buf, singleCRLF) {
b.r.Discard(2)
return nil
}
if len(buf) < 2 {
return errTrailerEOF
}
if err != nil {
return err
}
if !seeUpcomingDoubleCRLF(b.r) {
return errors.New("http: suspiciously long trailer after chunked body")
}
hdr, err := textproto.NewReader(b.r).ReadMIMEHeader()
if err != nil {
if err == io.EOF {
return errTrailerEOF
}
return err
}
switch rr := b.hdr.(type) {
case *Request:
mergeSetHeader(&rr.Trailer, Header(hdr))
case *Response:
mergeSetHeader(&rr.Trailer, Header(hdr))
}
return nil
}
func mergeSetHeader(dst *Header, src Header) {
if *dst == nil {
*dst = src
return
}
for k, vv := range src {
(*dst)[k] = vv
}
}
// unreadDataSizeLocked returns the number of bytes of unread input.
// It returns -1 if unknown.
// b.mu must be held.
func (b *body) unreadDataSizeLocked() int64 {
if lr, ok := b.src.(*io.LimitedReader); ok {
return lr.N
}
return -1
}
func (b *body) Close() error {
b.mu.Lock()
defer b.mu.Unlock()
if b.closed {
return nil
}
var err error
switch {
case b.sawEOF:
case b.hdr == nil && b.closing:
case b.doEarlyClose:
if lr, ok := b.src.(*io.LimitedReader); ok && lr.N > maxPostHandlerReadBytes {
b.earlyClose = true
} else {
var n int64
n, err = io.CopyN(ioutil.Discard, bodyLocked{b}, maxPostHandlerReadBytes)
if err == io.EOF {
err = nil
}
if n == maxPostHandlerReadBytes {
b.earlyClose = true
}
}
default:
_, err = io.Copy(ioutil.Discard, bodyLocked{b})
}
b.closed = true
return err
}
func (b *body) didEarlyClose() bool {
b.mu.Lock()
defer b.mu.Unlock()
return b.earlyClose
}
// bodyLocked is a io.Reader reading from a *body when its mutex is
// already held.
type bodyLocked struct {
b *body
}
func (bl bodyLocked) Read(p []byte) (n int, err error) {
if bl.b.closed {
return 0, ErrBodyReadAfterClose
}
return bl.b.readLocked(p)
}
// parseContentLength trims whitespace from s and returns -1 if no value
// is set, or the value if it's >= 0.
func parseContentLength(cl string) (int64, error) {
cl = strings.TrimSpace(cl)
if cl == "" {
return -1, nil
}
n, err := strconv.ParseInt(cl, 10, 64)
if err != nil || n < 0 {
return 0, &badStringError{"bad Content-Length", cl}
}
return n, nil
}
// DefaultTransport is the default implementation of Transport and is
// used by DefaultClient. It establishes network connections as needed
// and caches them for reuse by subsequent calls. It uses HTTP proxies
// as directed by the $HTTP_PROXY and $NO_PROXY (or $http_proxy and
// $no_proxy) environment variables.
var DefaultTransport RoundTripper = &Transport{
Proxy: ProxyFromEnvironment,
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
TLSHandshakeTimeout: 10 * time.Second,
}
// DefaultMaxIdleConnsPerHost is the default value of Transport's
// MaxIdleConnsPerHost.
const DefaultMaxIdleConnsPerHost = 2
// Transport is an implementation of RoundTripper that supports HTTP,
// HTTPS, and HTTP proxies (for either HTTP or HTTPS with CONNECT).
// Transport can also cache connections for future re-use.
type Transport struct {
idleMu sync.Mutex
wantIdle bool // user has requested to close all idle conns
idleConn map[connectMethodKey][]*persistConn
idleConnCh map[connectMethodKey]chan *persistConn
reqMu sync.Mutex
reqCanceler map[*Request]func()
altMu sync.RWMutex
altProto map[string]RoundTripper // nil or map of URI scheme => RoundTripper
// Proxy specifies a function to return a proxy for a given
// Request. If the function returns a non-nil error, the
// request is aborted with the provided error.
// If Proxy is nil or returns a nil *URL, no proxy is used.
Proxy func(*Request) (*url.URL, error)
// Dial specifies the dial function for creating unencrypted
// TCP connections.
// If Dial is nil, net.Dial is used.
Dial func(network, addr string) (net.Conn, error)
// DialTLS specifies an optional dial function for creating
// TLS connections for non-proxied HTTPS requests.
//
// If DialTLS is nil, Dial and TLSClientConfig are used.
//
// If DialTLS is set, the Dial hook is not used for HTTPS
// requests and the TLSClientConfig and TLSHandshakeTimeout
// are ignored. The returned net.Conn is assumed to already be
// past the TLS handshake.
DialTLS func(network, addr string) (net.Conn, error)
// TLSClientConfig specifies the TLS configuration to use with
// tls.Client. If nil, the default configuration is used.
TLSClientConfig *tls.Config
// TLSHandshakeTimeout specifies the maximum amount of time waiting to
// wait for a TLS handshake. Zero means no timeout.
TLSHandshakeTimeout time.Duration
// DisableKeepAlives, if true, prevents re-use of TCP connections
// between different HTTP requests.
DisableKeepAlives bool
// DisableCompression, if true, prevents the Transport from
// requesting compression with an "Accept-Encoding: gzip"
// request header when the Request contains no existing
// Accept-Encoding value. If the Transport requests gzip on
// its own and gets a gzipped response, it's transparently
// decoded in the Response.Body. However, if the user
// explicitly requested gzip it is not automatically
// uncompressed.
DisableCompression bool
// MaxIdleConnsPerHost, if non-zero, controls the maximum idle
// (keep-alive) to keep per-host. If zero,
// DefaultMaxIdleConnsPerHost is used.
MaxIdleConnsPerHost int
// ResponseHeaderTimeout, if non-zero, specifies the amount of
// time to wait for a server's response headers after fully
// writing the request (including its body, if any). This
// time does not include the time to read the response body.
ResponseHeaderTimeout time.Duration
}
// ProxyFromEnvironment returns the URL of the proxy to use for a
// given request, as indicated by the environment variables
// HTTP_PROXY, HTTPS_PROXY and NO_PROXY (or the lowercase versions
// thereof). HTTPS_PROXY takes precedence over HTTP_PROXY for https
// requests.
//
// The environment values may be either a complete URL or a
// "host[:port]", in which case the "http" scheme is assumed.
// An error is returned if the value is a different form.
//
// A nil URL and nil error are returned if no proxy is defined in the
// environment, or a proxy should not be used for the given request,
// as defined by NO_PROXY.
//
// As a special case, if req.URL.Host is "localhost" (with or without
// a port number), then a nil URL and nil error will be returned.
func ProxyFromEnvironment(req *Request) (*url.URL, error) {
var proxy string
if req.URL.Scheme == "https" {
proxy = httpsProxyEnv.Get()
}
if proxy == "" {
proxy = httpProxyEnv.Get()
}
if proxy == "" {
return nil, nil
}
if !useProxy(canonicalAddr(req.URL)) {
return nil, nil
}
proxyURL, err := url.Parse(proxy)
if err != nil || !strings.HasPrefix(proxyURL.Scheme, "http") {
if proxyURL, err := url.Parse("http://" + proxy); err == nil {
return proxyURL, nil
}
}
if err != nil {
return nil, fmt.Errorf("invalid proxy address %q: %v", proxy, err)
}
return proxyURL, nil
}
// ProxyURL returns a proxy function (for use in a Transport)
// that always returns the same URL.
func ProxyURL(fixedURL *url.URL) func(*Request) (*url.URL, error) {
return func(*Request) (*url.URL, error) {
return fixedURL, nil
}
}
// transportRequest is a wrapper around a *Request that adds
// optional extra headers to write.
type transportRequest struct {
*Request // original request, not to be mutated
extra Header // extra headers to write, or nil
}
func (tr *transportRequest) extraHeaders() Header {
if tr.extra == nil {
tr.extra = make(Header)
}
return tr.extra
}
// RoundTrip implements the RoundTripper interface.
//
// For higher-level HTTP client support (such as handling of cookies
// and redirects), see Get, Post, and the Client type.
func (t *Transport) RoundTrip(req *Request) (resp *Response, err error) {
if req.URL == nil {
req.closeBody()
return nil, errors.New("http: nil Request.URL")
}
if req.Header == nil {
req.closeBody()
return nil, errors.New("http: nil Request.Header")
}
if req.URL.Scheme != "http" && req.URL.Scheme != "https" {
t.altMu.RLock()
var rt RoundTripper
if t.altProto != nil {
rt = t.altProto[req.URL.Scheme]
}
t.altMu.RUnlock()
if rt == nil {
req.closeBody()
return nil, &badStringError{"unsupported protocol scheme", req.URL.Scheme}
}
return rt.RoundTrip(req)
}
if req.URL.Host == "" {
req.closeBody()
return nil, errors.New("http: no Host in request URL")
}
treq := &transportRequest{Request: req}
cm, err := t.connectMethodForRequest(treq)
if err != nil {
req.closeBody()
return nil, err
}
pconn, err := t.getConn(req, cm)
if err != nil {
t.setReqCanceler(req, nil)
req.closeBody()
return nil, err
}
return pconn.roundTrip(treq)
}
// RegisterProtocol registers a new protocol with scheme.
// The Transport will pass requests using the given scheme to rt.
// It is rt's responsibility to simulate HTTP request semantics.
//
// RegisterProtocol can be used by other packages to provide
// implementations of protocol schemes like "ftp" or "file".
func (t *Transport) RegisterProtocol(scheme string, rt RoundTripper) {
if scheme == "http" || scheme == "https" {
panic("protocol " + scheme + " already registered")
}
t.altMu.Lock()
defer t.altMu.Unlock()
if t.altProto == nil {
t.altProto = make(map[string]RoundTripper)
}
if _, exists := t.altProto[scheme]; exists {
panic("protocol " + scheme + " already registered")
}
t.altProto[scheme] = rt
}
// CloseIdleConnections closes any connections 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.
func (t *Transport) CloseIdleConnections() {
t.idleMu.Lock()
m := t.idleConn
t.idleConn = nil
t.idleConnCh = nil
t.wantIdle = true
t.idleMu.Unlock()
for _, conns := range m {
for _, pconn := range conns {
pconn.close()
}
}
}
// CancelRequest cancels an in-flight request by closing its connection.
// CancelRequest should only be called after RoundTrip has returned.
func (t *Transport) CancelRequest(req *Request) {
t.reqMu.Lock()
cancel := t.reqCanceler[req]
delete(t.reqCanceler, req)
t.reqMu.Unlock()
if cancel != nil {
cancel()
}
}
var (
httpProxyEnv = &envOnce{
names: []string{"HTTP_PROXY", "http_proxy"},
}
httpsProxyEnv = &envOnce{
names: []string{"HTTPS_PROXY", "https_proxy"},
}
noProxyEnv = &envOnce{
names: []string{"NO_PROXY", "no_proxy"},
}
)
// envOnce looks up an environment variable (optionally by multiple
// names) once. It mitigates expensive lookups on some platforms
// (e.g. Windows).
type envOnce struct {
names []string
once sync.Once
val string
}
func (e *envOnce) Get() string {
e.once.Do(e.init)
return e.val
}
func (e *envOnce) init() {
for _, n := range e.names {
e.val = os.Getenv(n)
if e.val != "" {
return
}
}
}
// reset is used by tests
func (e *envOnce) reset() {
e.once = sync.Once{}
e.val = ""
}
func (t *Transport) connectMethodForRequest(treq *transportRequest) (cm connectMethod, err error) {
cm.targetScheme = treq.URL.Scheme
cm.targetAddr = canonicalAddr(treq.URL)
if t.Proxy != nil {
cm.proxyURL, err = t.Proxy(treq.Request)
}
return cm, err
}
// proxyAuth returns the Proxy-Authorization header to set
// on requests, if applicable.
func (cm *connectMethod) proxyAuth() string {
if cm.proxyURL == nil {
return ""
}
if u := cm.proxyURL.User; u != nil {
username := u.Username()
password, _ := u.Password()
return "Basic " + basicAuth(username, password)
}
return ""
}
// putIdleConn adds pconn to the list of idle persistent connections awaiting
// a new request.
// If pconn is no longer needed or not in a good state, putIdleConn
// returns false.
func (t *Transport) putIdleConn(pconn *persistConn) bool {
if t.DisableKeepAlives || t.MaxIdleConnsPerHost < 0 {
pconn.close()
return false
}
if pconn.isBroken() {
return false
}
key := pconn.cacheKey
max := t.MaxIdleConnsPerHost
if max == 0 {
max = DefaultMaxIdleConnsPerHost
}
t.idleMu.Lock()
waitingDialer := t.idleConnCh[key]
select {
case waitingDialer <- pconn:
t.idleMu.Unlock()
return true
default:
if waitingDialer != nil {
delete(t.idleConnCh, key)
}
}
if t.wantIdle {
t.idleMu.Unlock()
pconn.close()
return false
}
if t.idleConn == nil {
t.idleConn = make(map[connectMethodKey][]*persistConn)
}
if len(t.idleConn[key]) >= max {
t.idleMu.Unlock()
pconn.close()
return false
}
for _, exist := range t.idleConn[key] {
if exist == pconn {
log.Fatalf("dup idle pconn %p in freelist", pconn)
}
}
t.idleConn[key] = append(t.idleConn[key], pconn)
t.idleMu.Unlock()
return true
}
// getIdleConnCh returns a channel to receive and return idle
// persistent connection for the given connectMethod.
// It may return nil, if persistent connections are not being used.
func (t *Transport) getIdleConnCh(cm connectMethod) chan *persistConn {
if t.DisableKeepAlives {
return nil
}
key := cm.key()
t.idleMu.Lock()
defer t.idleMu.Unlock()
t.wantIdle = false
if t.idleConnCh == nil {
t.idleConnCh = make(map[connectMethodKey]chan *persistConn)
}
ch, ok := t.idleConnCh[key]
if !ok {
ch = make(chan *persistConn)
t.idleConnCh[key] = ch
}
return ch
}
func (t *Transport) getIdleConn(cm connectMethod) (pconn *persistConn) {
key := cm.key()
t.idleMu.Lock()
defer t.idleMu.Unlock()
if t.idleConn == nil {
return nil
}
for {
pconns, ok := t.idleConn[key]
if !ok {
return nil
}
if len(pconns) == 1 {
pconn = pconns[0]
delete(t.idleConn, key)
} else {
pconn = pconns[len(pconns)-1]
t.idleConn[key] = pconns[:len(pconns)-1]
}
if !pconn.isBroken() {
return
}
}
}
func (t *Transport) setReqCanceler(r *Request, fn func()) {
t.reqMu.Lock()
defer t.reqMu.Unlock()
if t.reqCanceler == nil {
t.reqCanceler = make(map[*Request]func())
}
if fn != nil {
t.reqCanceler[r] = fn
} else {
delete(t.reqCanceler, r)
}
}
// replaceReqCanceler replaces an existing cancel function. If there is no cancel function
// for the request, we don't set the function and return false.
// Since CancelRequest will clear the canceler, we can use the return value to detect if
// the request was canceled since the last setReqCancel call.
func (t *Transport) replaceReqCanceler(r *Request, fn func()) bool {
t.reqMu.Lock()
defer t.reqMu.Unlock()
_, ok := t.reqCanceler[r]
if !ok {
return false
}
if fn != nil {
t.reqCanceler[r] = fn
} else {
delete(t.reqCanceler, r)
}
return true
}
func (t *Transport) dial(network, addr string) (c net.Conn, err error) {
if t.Dial != nil {
return t.Dial(network, addr)
}
return net.Dial(network, addr)
}
// Testing hooks:
var prePendingDial, postPendingDial func()
// getConn dials and creates a new persistConn to the target as
// specified in the connectMethod. This includes doing a proxy CONNECT
// and/or setting up TLS. If this doesn't return an error, the persistConn
// is ready to write requests to.
func (t *Transport) getConn(req *Request, cm connectMethod) (*persistConn, error) {
if pc := t.getIdleConn(cm); pc != nil {
t.setReqCanceler(req, func() {})
return pc, nil
}
type dialRes struct {
pc *persistConn
err error
}
dialc := make(chan dialRes)
prePendingDial := prePendingDial
postPendingDial := postPendingDial
handlePendingDial := func() {
if prePendingDial != nil {
prePendingDial()
}
go func() {
if v := <-dialc; v.err == nil {
t.putIdleConn(v.pc)
}
if postPendingDial != nil {
postPendingDial()
}
}()
}
cancelc := make(chan struct{})
t.setReqCanceler(req, func() { close(cancelc) })
go func() {
pc, err := t.dialConn(cm)
dialc <- dialRes{pc, err}
}()
idleConnCh := t.getIdleConnCh(cm)
select {
case v := <-dialc:
return v.pc, v.err
case pc := <-idleConnCh:
handlePendingDial()
return pc, nil
case <-req.Cancel:
handlePendingDial()
return nil, errors.New("net/http: request canceled while waiting for connection")
case <-cancelc:
handlePendingDial()
return nil, errors.New("net/http: request canceled while waiting for connection")
}
}
func (t *Transport) dialConn(cm connectMethod) (*persistConn, error) {
pconn := &persistConn{
t: t,
cacheKey: cm.key(),
reqch: make(chan requestAndChan, 1),
writech: make(chan writeRequest, 1),
closech: make(chan struct{}),
writeErrCh: make(chan error, 1),
}
tlsDial := t.DialTLS != nil && cm.targetScheme == "https" && cm.proxyURL == nil
if tlsDial {
var err error
pconn.conn, err = t.DialTLS("tcp", cm.addr())
if err != nil {
return nil, err
}
if tc, ok := pconn.conn.(*tls.Conn); ok {
cs := tc.ConnectionState()
pconn.tlsState = &cs
}
} else {
conn, err := t.dial("tcp", cm.addr())
if err != nil {
if cm.proxyURL != nil {
err = fmt.Errorf("http: error connecting to proxy %s: %v", cm.proxyURL, err)
}
return nil, err
}
pconn.conn = conn
}
switch {
case cm.proxyURL == nil:
case cm.targetScheme == "http":
pconn.isProxy = true
if pa := cm.proxyAuth(); pa != "" {
pconn.mutateHeaderFunc = func(h Header) {
h.Set("Proxy-Authorization", pa)
}
}
case cm.targetScheme == "https":
conn := pconn.conn
connectReq := &Request{
Method: "CONNECT",
URL: &url.URL{Opaque: cm.targetAddr},
Host: cm.targetAddr,
Header: make(Header),
}
if pa := cm.proxyAuth(); pa != "" {
connectReq.Header.Set("Proxy-Authorization", pa)
}
connectReq.Write(conn)
br := bufio.NewReader(conn)
resp, err := ReadResponse(br, connectReq)
if err != nil {
conn.Close()
return nil, err
}
if resp.StatusCode != 200 {
f := strings.SplitN(resp.Status, " ", 2)
conn.Close()
return nil, errors.New(f[1])
}
}
if cm.targetScheme == "https" && !tlsDial {
cfg := cloneTLSClientConfig(t.TLSClientConfig)
if cfg.ServerName == "" {
cfg.ServerName = cm.tlsHost()
}
plainConn := pconn.conn
tlsConn := tls.Client(plainConn, cfg)
errc := make(chan error, 2)
var timer *time.Timer // for canceling TLS handshake
if d := t.TLSHandshakeTimeout; d != 0 {
timer = time.AfterFunc(d, func() {
errc <- tlsHandshakeTimeoutError{}
})
}
go func() {
err := tlsConn.Handshake()
if timer != nil {
timer.Stop()
}
errc <- err
}()
if err := <-errc; err != nil {
plainConn.Close()
return nil, err
}
if !cfg.InsecureSkipVerify {
if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
plainConn.Close()
return nil, err
}
}
cs := tlsConn.ConnectionState()
pconn.tlsState = &cs
pconn.conn = tlsConn
}
pconn.br = bufio.NewReader(noteEOFReader{pconn.conn, &pconn.sawEOF})
pconn.bw = bufio.NewWriter(pconn.conn)
go pconn.readLoop()
go pconn.writeLoop()
return pconn, nil
}
// useProxy reports whether requests to addr should use a proxy,
// according to the NO_PROXY or no_proxy environment variable.
// addr is always a canonicalAddr with a host and port.
func useProxy(addr string) bool {
if len(addr) == 0 {
return true
}
host, _, err := net.SplitHostPort(addr)
if err != nil {
return false
}
if host == "localhost" {
return false
}
if ip := net.ParseIP(host); ip != nil {
if ip.IsLoopback() {
return false
}
}
no_proxy := noProxyEnv.Get()
if no_proxy == "*" {
return false
}
addr = strings.ToLower(strings.TrimSpace(addr))
if hasPort(addr) {
addr = addr[:strings.LastIndex(addr, ":")]
}
for _, p := range strings.Split(no_proxy, ",") {
p = strings.ToLower(strings.TrimSpace(p))
if len(p) == 0 {
continue
}
if hasPort(p) {
p = p[:strings.LastIndex(p, ":")]
}
if addr == p {
return false
}
if p[0] == '.' && (strings.HasSuffix(addr, p) || addr == p[1:]) {
return false
}
if p[0] != '.' && strings.HasSuffix(addr, p) && addr[len(addr)-len(p)-1] == '.' {
return false
}
}
return true
}
// connectMethod is the map key (in its String form) for keeping persistent
// TCP connections alive for subsequent HTTP requests.
//
// A connect method may be of the following types:
//
// Cache key form Description
// ----------------- -------------------------
// |http|foo.com http directly to server, no proxy
// |https|foo.com https directly to server, no proxy
// http://proxy.com|https|foo.com http to proxy, then CONNECT to foo.com
// http://proxy.com|http http to proxy, http to anywhere after that
//
// Note: no support to https to the proxy yet.
//
type connectMethod struct {
proxyURL *url.URL // nil for no proxy, else full proxy URL
targetScheme string // "http" or "https"
targetAddr string // Not used if proxy + http targetScheme (4th example in table)
}
func (cm *connectMethod) key() connectMethodKey {
proxyStr := ""
targetAddr := cm.targetAddr
if cm.proxyURL != nil {
proxyStr = cm.proxyURL.String()
if cm.targetScheme == "http" {
targetAddr = ""
}
}
return connectMethodKey{
proxy: proxyStr,
scheme: cm.targetScheme,
addr: targetAddr,
}
}
// addr returns the first hop "host:port" to which we need to TCP connect.
func (cm *connectMethod) addr() string {
if cm.proxyURL != nil {
return canonicalAddr(cm.proxyURL)
}
return cm.targetAddr
}
// tlsHost returns the host name to match against the peer's
// TLS certificate.
func (cm *connectMethod) tlsHost() string {
h := cm.targetAddr
if hasPort(h) {
h = h[:strings.LastIndex(h, ":")]
}
return h
}
// connectMethodKey is the map key version of connectMethod, with a
// stringified proxy URL (or the empty string) instead of a pointer to
// a URL.
type connectMethodKey struct {
proxy, scheme, addr string
}
func (k connectMethodKey) String() string {
return fmt.Sprintf("%s|%s|%s", k.proxy, k.scheme, k.addr)
}
// persistConn wraps a connection, usually a persistent one
// (but may be used for non-keep-alive requests as well)
type persistConn struct {
t *Transport
cacheKey connectMethodKey
conn net.Conn
tlsState *tls.ConnectionState
br *bufio.Reader // from conn
sawEOF bool // whether we've seen EOF from conn; owned by readLoop
bw *bufio.Writer // to conn
reqch chan requestAndChan // written by roundTrip; read by readLoop
writech chan writeRequest // written by roundTrip; read by writeLoop
closech chan struct{} // closed when conn closed
isProxy bool
// writeErrCh passes the request write error (usually nil)
// from the writeLoop goroutine to the readLoop which passes
// it off to the res.Body reader, which then uses it to decide
// whether or not a connection can be reused. Issue 7569.
writeErrCh chan error
lk sync.Mutex // guards following fields
numExpectedResponses int
closed bool // whether conn has been closed
broken bool // an error has happened on this connection; marked broken so it's not reused.
canceled bool // whether this conn was broken due a CancelRequest
// mutateHeaderFunc is an optional func to modify extra
// headers on each outbound request before it's written. (the
// original Request given to RoundTrip is not modified)
mutateHeaderFunc func(Header)
}
// isBroken reports whether this connection is in a known broken state.
func (pc *persistConn) isBroken() bool {
pc.lk.Lock()
b := pc.broken
pc.lk.Unlock()
return b
}
// isCanceled reports whether this connection was closed due to CancelRequest.
func (pc *persistConn) isCanceled() bool {
pc.lk.Lock()
defer pc.lk.Unlock()
return pc.canceled
}
func (pc *persistConn) cancelRequest() {
pc.lk.Lock()
defer pc.lk.Unlock()
pc.canceled = true
pc.closeLocked()
}
func (pc *persistConn) readLoop() {
eofc := make(chan struct{})
defer close(eofc)
testHookMu.Lock()
testHookReadLoopBeforeNextRead := testHookReadLoopBeforeNextRead
testHookMu.Unlock()
alive := true
for alive {
pb, err := pc.br.Peek(1)
pc.lk.Lock()
if pc.numExpectedResponses == 0 {
if !pc.closed {
pc.closeLocked()
if len(pb) > 0 {
log.Printf("Unsolicited response received on idle HTTP channel starting with %q; err=%v",
string(pb), err)
}
}
pc.lk.Unlock()
return
}
pc.lk.Unlock()
rc := <-pc.reqch
var resp *Response
if err == nil {
resp, err = ReadResponse(pc.br, rc.req)
if err == nil && resp.StatusCode == 100 {
resp, err = ReadResponse(pc.br, rc.req)
}
}
if resp != nil {
resp.TLS = pc.tlsState
}
hasBody := resp != nil && rc.req.Method != "HEAD" && resp.ContentLength != 0
if err != nil {
pc.close()
} else {
if rc.addedGzip && hasBody && resp.Header.Get("Content-Encoding") == "gzip" {
resp.Header.Del("Content-Encoding")
resp.Header.Del("Content-Length")
resp.ContentLength = -1
resp.Body = &gzipReader{body: resp.Body}
}
resp.Body = &bodyEOFSignal{body: resp.Body}
}
if err != nil || resp.Close || rc.req.Close || resp.StatusCode <= 199 {
alive = false
}
var waitForBodyRead chan bool // channel is nil when there's no body
if hasBody {
waitForBodyRead = make(chan bool, 2)
resp.Body.(*bodyEOFSignal).earlyCloseFn = func() error {
waitForBodyRead <- false
return nil
}
resp.Body.(*bodyEOFSignal).fn = func(err error) error {
isEOF := err == io.EOF
waitForBodyRead <- isEOF
if isEOF {
<-eofc
} else if err != nil && pc.isCanceled() {
return errRequestCanceled
}
return err
}
} else {
pc.t.setReqCanceler(rc.req, nil)
}
pc.lk.Lock()
pc.numExpectedResponses--
pc.lk.Unlock()
rc.ch <- responseAndError{resp, err}
if hasBody {
select {
case <-rc.req.Cancel:
alive = false
pc.t.CancelRequest(rc.req)
case bodyEOF := <-waitForBodyRead:
pc.t.setReqCanceler(rc.req, nil)
alive = alive &&
bodyEOF &&
!pc.sawEOF &&
pc.wroteRequest() &&
pc.t.putIdleConn(pc)
if bodyEOF {
eofc <- struct{}{}
}
case <-pc.closech:
alive = false
}
} else {
alive = alive &&
!pc.sawEOF &&
pc.wroteRequest() &&
pc.t.putIdleConn(pc)
}
if hook := testHookReadLoopBeforeNextRead; hook != nil {
hook()
}
}
pc.close()
}
func (pc *persistConn) writeLoop() {
for {
select {
case wr := <-pc.writech:
if pc.isBroken() {
wr.ch <- errors.New("http: can't write HTTP request on broken connection")
continue
}
err := wr.req.Request.write(pc.bw, pc.isProxy, wr.req.extra)
if err == nil {
err = pc.bw.Flush()
}
if err != nil {
pc.markBroken()
wr.req.Request.closeBody()
}
pc.writeErrCh <- err
wr.ch <- err
case <-pc.closech:
return
}
}
}
// wroteRequest is a check before recycling a connection that the previous write
// (from writeLoop above) happened and was successful.
func (pc *persistConn) wroteRequest() bool {
select {
case err := <-pc.writeErrCh:
return err == nil
default:
select {
case err := <-pc.writeErrCh:
return err == nil
case <-time.After(50 * time.Millisecond):
return false
}
}
}
type responseAndError struct {
res *Response
err error
}
type requestAndChan struct {
req *Request
ch chan responseAndError
// did the Transport (as opposed to the client code) add an
// Accept-Encoding gzip header? only if it we set it do
// we transparently decode the gzip.
addedGzip bool
}
// A writeRequest is sent by the readLoop's goroutine to the
// writeLoop's goroutine to write a request while the read loop
// concurrently waits on both the write response and the server's
// reply.
type writeRequest struct {
req *transportRequest
ch chan<- error
}
type httpError struct {
err string
timeout bool
}
func (e *httpError) Error() string { return e.err }
func (e *httpError) Timeout() bool { return e.timeout }
func (e *httpError) Temporary() bool { return true }
var errTimeout error = &httpError{err: "net/http: timeout awaiting response headers", timeout: true}
var errClosed error = &httpError{err: "net/http: transport closed before response was received"}
var errRequestCanceled = errors.New("net/http: request canceled")
// nil except for tests
var (
testHookPersistConnClosedGotRes func()
testHookEnterRoundTrip func()
testHookMu sync.Locker = fakeLocker{} // guards following
testHookReadLoopBeforeNextRead func()
)
func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err error) {
if hook := testHookEnterRoundTrip; hook != nil {
hook()
}
if !pc.t.replaceReqCanceler(req.Request, pc.cancelRequest) {
pc.t.putIdleConn(pc)
return nil, errRequestCanceled
}
pc.lk.Lock()
pc.numExpectedResponses++
headerFn := pc.mutateHeaderFunc
pc.lk.Unlock()
if headerFn != nil {
headerFn(req.extraHeaders())
}
requestedGzip := false
if !pc.t.DisableCompression &&
req.Header.Get("Accept-Encoding") == "" &&
req.Header.Get("Range") == "" &&
req.Method != "HEAD" {
requestedGzip = true
req.extraHeaders().Set("Accept-Encoding", "gzip")
}
if pc.t.DisableKeepAlives {
req.extraHeaders().Set("Connection", "close")
}
writeErrCh := make(chan error, 1)
pc.writech <- writeRequest{req, writeErrCh}
resc := make(chan responseAndError, 1)
pc.reqch <- requestAndChan{req.Request, resc, requestedGzip}
var re responseAndError
var respHeaderTimer <-chan time.Time
cancelChan := req.Request.Cancel
WaitResponse:
for {
select {
case err := <-writeErrCh:
if isNetWriteError(err) {
select {
case re = <-resc:
pc.close()
break WaitResponse
case <-time.After(50 * time.Millisecond):
}
}
if err != nil {
re = responseAndError{nil, err}
pc.close()
break WaitResponse
}
if d := pc.t.ResponseHeaderTimeout; d > 0 {
timer := time.NewTimer(d)
defer timer.Stop()
respHeaderTimer = timer.C
}
case <-pc.closech:
select {
case re = <-resc:
if fn := testHookPersistConnClosedGotRes; fn != nil {
fn()
}
default:
re = responseAndError{err: errClosed}
if pc.isCanceled() {
re = responseAndError{err: errRequestCanceled}
}
}
break WaitResponse
case <-respHeaderTimer:
pc.close()
re = responseAndError{err: errTimeout}
break WaitResponse
case re = <-resc:
break WaitResponse
case <-cancelChan:
pc.t.CancelRequest(req.Request)
cancelChan = nil
}
}
if re.err != nil {
pc.t.setReqCanceler(req.Request, nil)
}
return re.res, re.err
}
// markBroken marks a connection as broken (so it's not reused).
// It differs from close in that it doesn't close the underlying
// connection for use when it's still being read.
func (pc *persistConn) markBroken() {
pc.lk.Lock()
defer pc.lk.Unlock()
pc.broken = true
}
func (pc *persistConn) close() {
pc.lk.Lock()
defer pc.lk.Unlock()
pc.closeLocked()
}
func (pc *persistConn) closeLocked() {
pc.broken = true
if !pc.closed {
pc.conn.Close()
pc.closed = true
close(pc.closech)
}
pc.mutateHeaderFunc = nil
}
var portMap = map[string]string{
"http": "80",
"https": "443",
}
// canonicalAddr returns url.Host but always with a ":port" suffix
func canonicalAddr(url *url.URL) string {
addr := url.Host
if !hasPort(addr) {
return addr + ":" + portMap[url.Scheme]
}
return addr
}
// bodyEOFSignal wraps a ReadCloser but runs fn (if non-nil) at most
// once, right before its final (error-producing) Read or Close call
// returns. fn should return the new error to return from Read or Close.
//
// If earlyCloseFn is non-nil and Close is called before io.EOF is
// seen, earlyCloseFn is called instead of fn, and its return value is
// the return value from Close.
type bodyEOFSignal struct {
body io.ReadCloser
mu sync.Mutex // guards following 4 fields
closed bool // whether Close has been called
rerr error // sticky Read error
fn func(error) error // err will be nil on Read io.EOF
earlyCloseFn func() error // optional alt Close func used if io.EOF not seen
}
func (es *bodyEOFSignal) Read(p []byte) (n int, err error) {
es.mu.Lock()
closed, rerr := es.closed, es.rerr
es.mu.Unlock()
if closed {
return 0, errors.New("http: read on closed response body")
}
if rerr != nil {
return 0, rerr
}
n, err = es.body.Read(p)
if err != nil {
es.mu.Lock()
defer es.mu.Unlock()
if es.rerr == nil {
es.rerr = err
}
err = es.condfn(err)
}
return
}
func (es *bodyEOFSignal) Close() error {
es.mu.Lock()
defer es.mu.Unlock()
if es.closed {
return nil
}
es.closed = true
if es.earlyCloseFn != nil && es.rerr != io.EOF {
return es.earlyCloseFn()
}
err := es.body.Close()
return es.condfn(err)
}
// caller must hold es.mu.
func (es *bodyEOFSignal) condfn(err error) error {
if es.fn == nil {
return err
}
err = es.fn(err)
es.fn = nil
return err
}
// gzipReader wraps a response body so it can lazily
// call gzip.NewReader on the first call to Read
type gzipReader struct {
body io.ReadCloser // underlying Response.Body
zr io.Reader // lazily-initialized gzip reader
}
func (gz *gzipReader) Read(p []byte) (n int, err error) {
if gz.zr == nil {
gz.zr, err = gzip.NewReader(gz.body)
if err != nil {
return 0, err
}
}
return gz.zr.Read(p)
}
func (gz *gzipReader) Close() error {
return gz.body.Close()
}
type readerAndCloser struct {
io.Reader
io.Closer
}
type tlsHandshakeTimeoutError struct{}
func (tlsHandshakeTimeoutError) Timeout() bool { return true }
func (tlsHandshakeTimeoutError) Temporary() bool { return true }
func (tlsHandshakeTimeoutError) Error() string { return "net/http: TLS handshake timeout" }
type noteEOFReader struct {
r io.Reader
sawEOF *bool
}
func (nr noteEOFReader) Read(p []byte) (n int, err error) {
n, err = nr.r.Read(p)
if err == io.EOF {
*nr.sawEOF = true
}
return
}
// fakeLocker is a sync.Locker which does nothing. It's used to guard
// test-only fields when not under test, to avoid runtime atomic
// overhead.
type fakeLocker struct{}
func (fakeLocker) Lock() {}
func (fakeLocker) Unlock() {}
func isNetWriteError(err error) bool {
switch e := err.(type) {
case *url.Error:
return isNetWriteError(e.Err)
case *net.OpError:
return e.Op == "write"
default:
return false
}
}
// cloneTLSConfig returns a shallow clone of the exported
// fields of cfg, ignoring the unexported sync.Once, which
// contains a mutex and must not be copied.
//
// The cfg must not be in active use by tls.Server, or else
// there can still be a race with tls.Server updating SessionTicketKey
// and our copying it, and also a race with the server setting
// SessionTicketsDisabled=false on failure to set the random
// ticket key.
//
// If cfg is nil, a new zero tls.Config is returned.
func cloneTLSConfig(cfg *tls.Config) *tls.Config {
if cfg == nil {
return &tls.Config{}
}
return &tls.Config{
Rand: cfg.Rand,
Time: cfg.Time,
Certificates: cfg.Certificates,
NameToCertificate: cfg.NameToCertificate,
GetCertificate: cfg.GetCertificate,
RootCAs: cfg.RootCAs,
NextProtos: cfg.NextProtos,
ServerName: cfg.ServerName,
ClientAuth: cfg.ClientAuth,
ClientCAs: cfg.ClientCAs,
InsecureSkipVerify: cfg.InsecureSkipVerify,
CipherSuites: cfg.CipherSuites,
PreferServerCipherSuites: cfg.PreferServerCipherSuites,
SessionTicketsDisabled: cfg.SessionTicketsDisabled,
SessionTicketKey: cfg.SessionTicketKey,
ClientSessionCache: cfg.ClientSessionCache,
MinVersion: cfg.MinVersion,
MaxVersion: cfg.MaxVersion,
CurvePreferences: cfg.CurvePreferences,
}
}
// cloneTLSClientConfig is like cloneTLSConfig but omits
// the fields SessionTicketsDisabled and SessionTicketKey.
// This makes it safe to call cloneTLSClientConfig on a config
// in active use by a server.
func cloneTLSClientConfig(cfg *tls.Config) *tls.Config {
if cfg == nil {
return &tls.Config{}
}
return &tls.Config{
Rand: cfg.Rand,
Time: cfg.Time,
Certificates: cfg.Certificates,
NameToCertificate: cfg.NameToCertificate,
GetCertificate: cfg.GetCertificate,
RootCAs: cfg.RootCAs,
NextProtos: cfg.NextProtos,
ServerName: cfg.ServerName,
ClientAuth: cfg.ClientAuth,
ClientCAs: cfg.ClientCAs,
InsecureSkipVerify: cfg.InsecureSkipVerify,
CipherSuites: cfg.CipherSuites,
PreferServerCipherSuites: cfg.PreferServerCipherSuites,
ClientSessionCache: cfg.ClientSessionCache,
MinVersion: cfg.MinVersion,
MaxVersion: cfg.MaxVersion,
CurvePreferences: cfg.CurvePreferences,
}
}
`