mirror of https://go.googlesource.com/go
3908 lines
123 KiB
Go
3908 lines
123 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// HTTP server. See RFC 7230 through 7235.
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package http
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import (
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"bufio"
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"bytes"
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"context"
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"crypto/tls"
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"errors"
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"fmt"
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"internal/godebug"
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"io"
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"log"
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"math/rand"
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"net"
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"net/textproto"
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"net/url"
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urlpkg "net/url"
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"path"
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"runtime"
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"slices"
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"strconv"
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"strings"
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"sync"
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"sync/atomic"
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"time"
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_ "unsafe" // for linkname
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"golang.org/x/net/http/httpguts"
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)
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// Errors used by the HTTP server.
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var (
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// ErrBodyNotAllowed is returned by ResponseWriter.Write calls
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// when the HTTP method or response code does not permit a
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// body.
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ErrBodyNotAllowed = errors.New("http: request method or response status code does not allow body")
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// ErrHijacked is returned by ResponseWriter.Write calls when
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// the underlying connection has been hijacked using the
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// Hijacker interface. A zero-byte write on a hijacked
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// connection will return ErrHijacked without any other side
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// effects.
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ErrHijacked = errors.New("http: connection has been hijacked")
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// ErrContentLength is returned by ResponseWriter.Write calls
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// when a Handler set a Content-Length response header with a
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// declared size and then attempted to write more bytes than
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// declared.
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ErrContentLength = errors.New("http: wrote more than the declared Content-Length")
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// Deprecated: ErrWriteAfterFlush is no longer returned by
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// anything in the net/http package. Callers should not
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// compare errors against this variable.
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ErrWriteAfterFlush = errors.New("unused")
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)
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// A Handler responds to an HTTP request.
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//
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// [Handler.ServeHTTP] should write reply headers and data to the [ResponseWriter]
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// and then return. Returning signals that the request is finished; it
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// is not valid to use the [ResponseWriter] or read from the
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// [Request.Body] after or concurrently with the completion of the
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// ServeHTTP call.
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//
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// Depending on the HTTP client software, HTTP protocol version, and
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// any intermediaries between the client and the Go server, it may not
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// be possible to read from the [Request.Body] after writing to the
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// [ResponseWriter]. Cautious handlers should read the [Request.Body]
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// first, and then reply.
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//
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// Except for reading the body, handlers should not modify the
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// provided Request.
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//
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// If ServeHTTP panics, the server (the caller of ServeHTTP) assumes
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// that the effect of the panic was isolated to the active request.
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// It recovers the panic, logs a stack trace to the server error log,
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// and either closes the network connection or sends an HTTP/2
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// RST_STREAM, depending on the HTTP protocol. To abort a handler so
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// the client sees an interrupted response but the server doesn't log
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// an error, panic with the value [ErrAbortHandler].
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type Handler interface {
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ServeHTTP(ResponseWriter, *Request)
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}
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// A ResponseWriter interface is used by an HTTP handler to
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// construct an HTTP response.
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//
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// A ResponseWriter may not be used after [Handler.ServeHTTP] has returned.
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type ResponseWriter interface {
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// Header returns the header map that will be sent by
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// [ResponseWriter.WriteHeader]. The [Header] map also is the mechanism with which
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// [Handler] implementations can set HTTP trailers.
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//
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// Changing the header map after a call to [ResponseWriter.WriteHeader] (or
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// [ResponseWriter.Write]) has no effect unless the HTTP status code was of the
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// 1xx class or the modified headers are trailers.
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//
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// There are two ways to set Trailers. The preferred way is to
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// predeclare in the headers which trailers you will later
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// send by setting the "Trailer" header to the names of the
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// trailer keys which will come later. In this case, those
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// keys of the Header map are treated as if they were
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// trailers. See the example. The second way, for trailer
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// keys not known to the [Handler] until after the first [ResponseWriter.Write],
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// is to prefix the [Header] map keys with the [TrailerPrefix]
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// constant value.
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//
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// To suppress automatic response headers (such as "Date"), set
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// their value to nil.
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Header() Header
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// Write writes the data to the connection as part of an HTTP reply.
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//
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// If [ResponseWriter.WriteHeader] has not yet been called, Write calls
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// WriteHeader(http.StatusOK) before writing the data. If the Header
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// does not contain a Content-Type line, Write adds a Content-Type set
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// to the result of passing the initial 512 bytes of written data to
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// [DetectContentType]. Additionally, if the total size of all written
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// data is under a few KB and there are no Flush calls, the
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// Content-Length header is added automatically.
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//
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// Depending on the HTTP protocol version and the client, calling
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// Write or WriteHeader may prevent future reads on the
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// Request.Body. For HTTP/1.x requests, handlers should read any
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// needed request body data before writing the response. Once the
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// headers have been flushed (due to either an explicit Flusher.Flush
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// call or writing enough data to trigger a flush), the request body
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// may be unavailable. For HTTP/2 requests, the Go HTTP server permits
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// handlers to continue to read the request body while concurrently
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// writing the response. However, such behavior may not be supported
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// by all HTTP/2 clients. Handlers should read before writing if
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// possible to maximize compatibility.
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Write([]byte) (int, error)
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// WriteHeader sends an HTTP response header with the provided
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// status code.
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//
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// If WriteHeader is not called explicitly, the first call to Write
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// will trigger an implicit WriteHeader(http.StatusOK).
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// Thus explicit calls to WriteHeader are mainly used to
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// send error codes or 1xx informational responses.
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//
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// The provided code must be a valid HTTP 1xx-5xx status code.
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// Any number of 1xx headers may be written, followed by at most
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// one 2xx-5xx header. 1xx headers are sent immediately, but 2xx-5xx
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// headers may be buffered. Use the Flusher interface to send
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// buffered data. The header map is cleared when 2xx-5xx headers are
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// sent, but not with 1xx headers.
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//
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// The server will automatically send a 100 (Continue) header
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// on the first read from the request body if the request has
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// an "Expect: 100-continue" header.
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WriteHeader(statusCode int)
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}
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// The Flusher interface is implemented by ResponseWriters that allow
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// an HTTP handler to flush buffered data to the client.
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//
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// The default HTTP/1.x and HTTP/2 [ResponseWriter] implementations
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// support [Flusher], but ResponseWriter wrappers may not. Handlers
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// should always test for this ability at runtime.
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//
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// Note that even for ResponseWriters that support Flush,
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// if the client is connected through an HTTP proxy,
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// the buffered data may not reach the client until the response
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// completes.
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type Flusher interface {
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// Flush sends any buffered data to the client.
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Flush()
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}
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// The Hijacker interface is implemented by ResponseWriters that allow
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// an HTTP handler to take over the connection.
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//
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// The default [ResponseWriter] for HTTP/1.x connections supports
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// Hijacker, but HTTP/2 connections intentionally do not.
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// ResponseWriter wrappers may also not support Hijacker. Handlers
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// should always test for this ability at runtime.
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type Hijacker interface {
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// Hijack lets the caller take over the connection.
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// After a call to Hijack the HTTP server library
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// will not do anything else with the connection.
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//
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// It becomes the caller's responsibility to manage
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// and close the connection.
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//
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// The returned net.Conn may have read or write deadlines
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// already set, depending on the configuration of the
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// Server. It is the caller's responsibility to set
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// or clear those deadlines as needed.
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//
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// The returned bufio.Reader may contain unprocessed buffered
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// data from the client.
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//
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// After a call to Hijack, the original Request.Body must not
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// be used. The original Request's Context remains valid and
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// is not canceled until the Request's ServeHTTP method
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// returns.
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Hijack() (net.Conn, *bufio.ReadWriter, error)
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}
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// The CloseNotifier interface is implemented by ResponseWriters which
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// allow detecting when the underlying connection has gone away.
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//
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// This mechanism can be used to cancel long operations on the server
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// if the client has disconnected before the response is ready.
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//
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// Deprecated: the CloseNotifier interface predates Go's context package.
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// New code should use [Request.Context] instead.
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type CloseNotifier interface {
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// CloseNotify returns a channel that receives at most a
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// single value (true) when the client connection has gone
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// away.
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//
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// CloseNotify may wait to notify until Request.Body has been
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// fully read.
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//
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// After the Handler has returned, there is no guarantee
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// that the channel receives a value.
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//
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// If the protocol is HTTP/1.1 and CloseNotify is called while
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// processing an idempotent request (such as GET) while
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// HTTP/1.1 pipelining is in use, the arrival of a subsequent
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// pipelined request may cause a value to be sent on the
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// returned channel. In practice HTTP/1.1 pipelining is not
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// enabled in browsers and not seen often in the wild. If this
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// is a problem, use HTTP/2 or only use CloseNotify on methods
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// such as POST.
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CloseNotify() <-chan bool
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}
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var (
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// ServerContextKey is a context key. It can be used in HTTP
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// handlers with Context.Value to access the server that
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// started the handler. The associated value will be of
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// type *Server.
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ServerContextKey = &contextKey{"http-server"}
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// LocalAddrContextKey is a context key. It can be used in
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// HTTP handlers with Context.Value to access the local
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// address the connection arrived on.
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// The associated value will be of type net.Addr.
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LocalAddrContextKey = &contextKey{"local-addr"}
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)
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// A conn represents the server side of an HTTP connection.
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type conn struct {
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// server is the server on which the connection arrived.
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// Immutable; never nil.
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server *Server
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// cancelCtx cancels the connection-level context.
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cancelCtx context.CancelFunc
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// rwc is the underlying network connection.
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// This is never wrapped by other types and is the value given out
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// to CloseNotifier callers. It is usually of type *net.TCPConn or
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// *tls.Conn.
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rwc net.Conn
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// remoteAddr is rwc.RemoteAddr().String(). It is not populated synchronously
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// inside the Listener's Accept goroutine, as some implementations block.
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// It is populated immediately inside the (*conn).serve goroutine.
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// This is the value of a Handler's (*Request).RemoteAddr.
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remoteAddr string
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// tlsState is the TLS connection state when using TLS.
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// nil means not TLS.
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tlsState *tls.ConnectionState
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// werr is set to the first write error to rwc.
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// It is set via checkConnErrorWriter{w}, where bufw writes.
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werr error
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// r is bufr's read source. It's a wrapper around rwc that provides
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// io.LimitedReader-style limiting (while reading request headers)
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// and functionality to support CloseNotifier. See *connReader docs.
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r *connReader
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// bufr reads from r.
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bufr *bufio.Reader
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// bufw writes to checkConnErrorWriter{c}, which populates werr on error.
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bufw *bufio.Writer
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// lastMethod is the method of the most recent request
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// on this connection, if any.
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lastMethod string
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curReq atomic.Pointer[response] // (which has a Request in it)
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curState atomic.Uint64 // packed (unixtime<<8|uint8(ConnState))
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// mu guards hijackedv
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mu sync.Mutex
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// hijackedv is whether this connection has been hijacked
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// by a Handler with the Hijacker interface.
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// It is guarded by mu.
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hijackedv bool
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}
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func (c *conn) hijacked() bool {
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c.mu.Lock()
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defer c.mu.Unlock()
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return c.hijackedv
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}
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// c.mu must be held.
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func (c *conn) hijackLocked() (rwc net.Conn, buf *bufio.ReadWriter, err error) {
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if c.hijackedv {
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return nil, nil, ErrHijacked
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}
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c.r.abortPendingRead()
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c.hijackedv = true
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rwc = c.rwc
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rwc.SetDeadline(time.Time{})
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buf = bufio.NewReadWriter(c.bufr, bufio.NewWriter(rwc))
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if c.r.hasByte {
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if _, err := c.bufr.Peek(c.bufr.Buffered() + 1); err != nil {
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return nil, nil, fmt.Errorf("unexpected Peek failure reading buffered byte: %v", err)
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}
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}
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c.setState(rwc, StateHijacked, runHooks)
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return
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}
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// This should be >= 512 bytes for DetectContentType,
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// but otherwise it's somewhat arbitrary.
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const bufferBeforeChunkingSize = 2048
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// chunkWriter writes to a response's conn buffer, and is the writer
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// wrapped by the response.w buffered writer.
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//
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// chunkWriter also is responsible for finalizing the Header, including
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// conditionally setting the Content-Type and setting a Content-Length
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// in cases where the handler's final output is smaller than the buffer
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// size. It also conditionally adds chunk headers, when in chunking mode.
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//
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// See the comment above (*response).Write for the entire write flow.
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type chunkWriter struct {
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res *response
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// header is either nil or a deep clone of res.handlerHeader
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// at the time of res.writeHeader, if res.writeHeader is
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// called and extra buffering is being done to calculate
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// Content-Type and/or Content-Length.
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header Header
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// wroteHeader tells whether the header's been written to "the
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// wire" (or rather: w.conn.buf). this is unlike
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// (*response).wroteHeader, which tells only whether it was
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// logically written.
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wroteHeader bool
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// set by the writeHeader method:
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chunking bool // using chunked transfer encoding for reply body
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}
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var (
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crlf = []byte("\r\n")
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colonSpace = []byte(": ")
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)
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func (cw *chunkWriter) Write(p []byte) (n int, err error) {
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if !cw.wroteHeader {
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cw.writeHeader(p)
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}
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if cw.res.req.Method == "HEAD" {
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// Eat writes.
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return len(p), nil
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}
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if cw.chunking {
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_, err = fmt.Fprintf(cw.res.conn.bufw, "%x\r\n", len(p))
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if err != nil {
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cw.res.conn.rwc.Close()
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return
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}
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}
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n, err = cw.res.conn.bufw.Write(p)
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if cw.chunking && err == nil {
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_, err = cw.res.conn.bufw.Write(crlf)
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}
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if err != nil {
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cw.res.conn.rwc.Close()
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}
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return
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}
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func (cw *chunkWriter) flush() error {
|
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if !cw.wroteHeader {
|
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cw.writeHeader(nil)
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}
|
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return cw.res.conn.bufw.Flush()
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}
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|
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func (cw *chunkWriter) close() {
|
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if !cw.wroteHeader {
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cw.writeHeader(nil)
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}
|
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if cw.chunking {
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bw := cw.res.conn.bufw // conn's bufio writer
|
||
// zero chunk to mark EOF
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bw.WriteString("0\r\n")
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if trailers := cw.res.finalTrailers(); trailers != nil {
|
||
trailers.Write(bw) // the writer handles noting errors
|
||
}
|
||
// final blank line after the trailers (whether
|
||
// present or not)
|
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bw.WriteString("\r\n")
|
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}
|
||
}
|
||
|
||
// A response represents the server side of an HTTP response.
|
||
type response struct {
|
||
conn *conn
|
||
req *Request // request for this response
|
||
reqBody io.ReadCloser
|
||
cancelCtx context.CancelFunc // when ServeHTTP exits
|
||
wroteHeader bool // a non-1xx header has been (logically) written
|
||
wants10KeepAlive bool // HTTP/1.0 w/ Connection "keep-alive"
|
||
wantsClose bool // HTTP request has Connection "close"
|
||
|
||
// canWriteContinue is an atomic boolean that says whether or
|
||
// not a 100 Continue header can be written to the
|
||
// connection.
|
||
// writeContinueMu must be held while writing the header.
|
||
// These two fields together synchronize the body reader (the
|
||
// expectContinueReader, which wants to write 100 Continue)
|
||
// against the main writer.
|
||
writeContinueMu sync.Mutex
|
||
canWriteContinue atomic.Bool
|
||
|
||
w *bufio.Writer // buffers output in chunks to chunkWriter
|
||
cw chunkWriter
|
||
|
||
// 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
|
||
|
||
// When fullDuplex is false (the default), we consume any remaining
|
||
// request body before starting to write a response.
|
||
fullDuplex 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 atomic.Bool // set true when the handler exits
|
||
|
||
// Buffers for Date, Content-Length, and status code
|
||
dateBuf [len(TimeFormat)]byte
|
||
clenBuf [10]byte
|
||
statusBuf [3]byte
|
||
|
||
// closeNotifyCh is the channel returned by CloseNotify.
|
||
// TODO(bradfitz): this is currently (for Go 1.8) always
|
||
// non-nil. Make this lazily-created again as it used to be?
|
||
closeNotifyCh chan bool
|
||
didCloseNotify atomic.Bool // atomic (only false->true winner should send)
|
||
}
|
||
|
||
func (c *response) SetReadDeadline(deadline time.Time) error {
|
||
return c.conn.rwc.SetReadDeadline(deadline)
|
||
}
|
||
|
||
func (c *response) SetWriteDeadline(deadline time.Time) error {
|
||
return c.conn.rwc.SetWriteDeadline(deadline)
|
||
}
|
||
|
||
func (c *response) EnableFullDuplex() error {
|
||
c.fullDuplex = true
|
||
return nil
|
||
}
|
||
|
||
// TrailerPrefix is a magic prefix for [ResponseWriter.Header] map keys
|
||
// that, if present, signals that the map entry is actually for
|
||
// the response trailers, and not the response headers. The prefix
|
||
// is stripped after the ServeHTTP call finishes and the values are
|
||
// sent in the trailers.
|
||
//
|
||
// This mechanism is intended only for trailers that are not known
|
||
// prior to the headers being written. If the set of trailers is fixed
|
||
// or known before the header is written, the normal Go trailers mechanism
|
||
// is preferred:
|
||
//
|
||
// https://pkg.go.dev/net/http#ResponseWriter
|
||
// https://pkg.go.dev/net/http#example-ResponseWriter-Trailers
|
||
const TrailerPrefix = "Trailer:"
|
||
|
||
// finalTrailers is called after the Handler exits and returns a non-nil
|
||
// value if the Handler set any trailers.
|
||
func (w *response) finalTrailers() Header {
|
||
var t Header
|
||
for k, vv := range w.handlerHeader {
|
||
if kk, found := strings.CutPrefix(k, TrailerPrefix); found {
|
||
if t == nil {
|
||
t = make(Header)
|
||
}
|
||
t[kk] = vv
|
||
}
|
||
}
|
||
for _, k := range w.trailers {
|
||
if t == nil {
|
||
t = make(Header)
|
||
}
|
||
for _, v := range w.handlerHeader[k] {
|
||
t.Add(k, v)
|
||
}
|
||
}
|
||
return t
|
||
}
|
||
|
||
// 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)
|
||
if !httpguts.ValidTrailerHeader(k) {
|
||
// Forbidden by RFC 7230, section 4.1.2
|
||
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")
|
||
}
|
||
}
|
||
|
||
// disableWriteContinue stops Request.Body.Read from sending an automatic 100-Continue.
|
||
// If a 100-Continue is being written, it waits for it to complete before continuing.
|
||
func (w *response) disableWriteContinue() {
|
||
w.writeContinueMu.Lock()
|
||
w.canWriteContinue.Store(false)
|
||
w.writeContinueMu.Unlock()
|
||
}
|
||
|
||
// writerOnly hides an io.Writer value's optional ReadFrom method
|
||
// from io.Copy.
|
||
type writerOnly struct {
|
||
io.Writer
|
||
}
|
||
|
||
// ReadFrom is here to optimize copying from an [*os.File] regular file
|
||
// to a [*net.TCPConn] with sendfile, or from a supported src type such
|
||
// as a *net.TCPConn on Linux with splice.
|
||
func (w *response) ReadFrom(src io.Reader) (n int64, err error) {
|
||
buf := getCopyBuf()
|
||
defer putCopyBuf(buf)
|
||
|
||
// Our underlying w.conn.rwc is usually a *TCPConn (with its
|
||
// own ReadFrom method). If not, just fall back to the normal
|
||
// copy method.
|
||
rf, ok := w.conn.rwc.(io.ReaderFrom)
|
||
if !ok {
|
||
return io.CopyBuffer(writerOnly{w}, src, buf)
|
||
}
|
||
|
||
// Copy the first sniffLen bytes before switching to ReadFrom.
|
||
// This ensures we don't start writing the response before the
|
||
// source is available (see golang.org/issue/5660) and provides
|
||
// enough bytes to perform Content-Type sniffing when required.
|
||
if !w.cw.wroteHeader {
|
||
n0, err := io.CopyBuffer(writerOnly{w}, io.LimitReader(src, sniffLen), buf)
|
||
n += n0
|
||
if err != nil || n0 < sniffLen {
|
||
return n, err
|
||
}
|
||
}
|
||
|
||
w.w.Flush() // get rid of any previous writes
|
||
w.cw.flush() // make sure Header is written; flush data to rwc
|
||
|
||
// Now that cw has been flushed, its chunking field is guaranteed initialized.
|
||
if !w.cw.chunking && w.bodyAllowed() {
|
||
n0, err := rf.ReadFrom(src)
|
||
n += n0
|
||
w.written += n0
|
||
return n, err
|
||
}
|
||
|
||
n0, err := io.CopyBuffer(writerOnly{w}, src, buf)
|
||
n += n0
|
||
return n, err
|
||
}
|
||
|
||
// 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) *conn {
|
||
c := &conn{
|
||
server: srv,
|
||
rwc: rwc,
|
||
}
|
||
if debugServerConnections {
|
||
c.rwc = newLoggingConn("server", c.rwc)
|
||
}
|
||
return c
|
||
}
|
||
|
||
type readResult struct {
|
||
_ incomparable
|
||
n int
|
||
err error
|
||
b byte // byte read, if n == 1
|
||
}
|
||
|
||
// connReader is the io.Reader wrapper used by *conn. It combines a
|
||
// selectively-activated io.LimitedReader (to bound request header
|
||
// read sizes) with support for selectively keeping an io.Reader.Read
|
||
// call blocked in a background goroutine to wait for activity and
|
||
// trigger a CloseNotifier channel.
|
||
type connReader struct {
|
||
conn *conn
|
||
|
||
mu sync.Mutex // guards following
|
||
hasByte bool
|
||
byteBuf [1]byte
|
||
cond *sync.Cond
|
||
inRead bool
|
||
aborted bool // set true before conn.rwc deadline is set to past
|
||
remain int64 // bytes remaining
|
||
}
|
||
|
||
func (cr *connReader) lock() {
|
||
cr.mu.Lock()
|
||
if cr.cond == nil {
|
||
cr.cond = sync.NewCond(&cr.mu)
|
||
}
|
||
}
|
||
|
||
func (cr *connReader) unlock() { cr.mu.Unlock() }
|
||
|
||
func (cr *connReader) startBackgroundRead() {
|
||
cr.lock()
|
||
defer cr.unlock()
|
||
if cr.inRead {
|
||
panic("invalid concurrent Body.Read call")
|
||
}
|
||
if cr.hasByte {
|
||
return
|
||
}
|
||
cr.inRead = true
|
||
cr.conn.rwc.SetReadDeadline(time.Time{})
|
||
go cr.backgroundRead()
|
||
}
|
||
|
||
func (cr *connReader) backgroundRead() {
|
||
n, err := cr.conn.rwc.Read(cr.byteBuf[:])
|
||
cr.lock()
|
||
if n == 1 {
|
||
cr.hasByte = true
|
||
// We were past the end of the previous request's body already
|
||
// (since we wouldn't be in a background read otherwise), so
|
||
// this is a pipelined HTTP request. Prior to Go 1.11 we used to
|
||
// send on the CloseNotify channel and cancel the context here,
|
||
// but the behavior was documented as only "may", and we only
|
||
// did that because that's how CloseNotify accidentally behaved
|
||
// in very early Go releases prior to context support. Once we
|
||
// added context support, people used a Handler's
|
||
// Request.Context() and passed it along. Having that context
|
||
// cancel on pipelined HTTP requests caused problems.
|
||
// Fortunately, almost nothing uses HTTP/1.x pipelining.
|
||
// Unfortunately, apt-get does, or sometimes does.
|
||
// New Go 1.11 behavior: don't fire CloseNotify or cancel
|
||
// contexts on pipelined requests. Shouldn't affect people, but
|
||
// fixes cases like Issue 23921. This does mean that a client
|
||
// closing their TCP connection after sending a pipelined
|
||
// request won't cancel the context, but we'll catch that on any
|
||
// write failure (in checkConnErrorWriter.Write).
|
||
// If the server never writes, yes, there are still contrived
|
||
// server & client behaviors where this fails to ever cancel the
|
||
// context, but that's kinda why HTTP/1.x pipelining died
|
||
// anyway.
|
||
}
|
||
if ne, ok := err.(net.Error); ok && cr.aborted && ne.Timeout() {
|
||
// Ignore this error. It's the expected error from
|
||
// another goroutine calling abortPendingRead.
|
||
} else if err != nil {
|
||
cr.handleReadError(err)
|
||
}
|
||
cr.aborted = false
|
||
cr.inRead = false
|
||
cr.unlock()
|
||
cr.cond.Broadcast()
|
||
}
|
||
|
||
func (cr *connReader) abortPendingRead() {
|
||
cr.lock()
|
||
defer cr.unlock()
|
||
if !cr.inRead {
|
||
return
|
||
}
|
||
cr.aborted = true
|
||
cr.conn.rwc.SetReadDeadline(aLongTimeAgo)
|
||
for cr.inRead {
|
||
cr.cond.Wait()
|
||
}
|
||
cr.conn.rwc.SetReadDeadline(time.Time{})
|
||
}
|
||
|
||
func (cr *connReader) setReadLimit(remain int64) { cr.remain = remain }
|
||
func (cr *connReader) setInfiniteReadLimit() { cr.remain = maxInt64 }
|
||
func (cr *connReader) hitReadLimit() bool { return cr.remain <= 0 }
|
||
|
||
// handleReadError is called whenever a Read from the client returns a
|
||
// non-nil error.
|
||
//
|
||
// The provided non-nil err is almost always io.EOF or a "use of
|
||
// closed network connection". In any case, the error is not
|
||
// particularly interesting, except perhaps for debugging during
|
||
// development. Any error means the connection is dead and we should
|
||
// down its context.
|
||
//
|
||
// It may be called from multiple goroutines.
|
||
func (cr *connReader) handleReadError(_ error) {
|
||
cr.conn.cancelCtx()
|
||
cr.closeNotify()
|
||
}
|
||
|
||
// may be called from multiple goroutines.
|
||
func (cr *connReader) closeNotify() {
|
||
res := cr.conn.curReq.Load()
|
||
if res != nil && !res.didCloseNotify.Swap(true) {
|
||
res.closeNotifyCh <- true
|
||
}
|
||
}
|
||
|
||
func (cr *connReader) Read(p []byte) (n int, err error) {
|
||
cr.lock()
|
||
if cr.inRead {
|
||
cr.unlock()
|
||
if cr.conn.hijacked() {
|
||
panic("invalid Body.Read call. After hijacked, the original Request must not be used")
|
||
}
|
||
panic("invalid concurrent Body.Read call")
|
||
}
|
||
if cr.hitReadLimit() {
|
||
cr.unlock()
|
||
return 0, io.EOF
|
||
}
|
||
if len(p) == 0 {
|
||
cr.unlock()
|
||
return 0, nil
|
||
}
|
||
if int64(len(p)) > cr.remain {
|
||
p = p[:cr.remain]
|
||
}
|
||
if cr.hasByte {
|
||
p[0] = cr.byteBuf[0]
|
||
cr.hasByte = false
|
||
cr.unlock()
|
||
return 1, nil
|
||
}
|
||
cr.inRead = true
|
||
cr.unlock()
|
||
n, err = cr.conn.rwc.Read(p)
|
||
|
||
cr.lock()
|
||
cr.inRead = false
|
||
if err != nil {
|
||
cr.handleReadError(err)
|
||
}
|
||
cr.remain -= int64(n)
|
||
cr.unlock()
|
||
|
||
cr.cond.Broadcast()
|
||
return n, err
|
||
}
|
||
|
||
var (
|
||
bufioReaderPool sync.Pool
|
||
bufioWriter2kPool sync.Pool
|
||
bufioWriter4kPool sync.Pool
|
||
)
|
||
|
||
const copyBufPoolSize = 32 * 1024
|
||
|
||
var copyBufPool = sync.Pool{New: func() any { return new([copyBufPoolSize]byte) }}
|
||
|
||
func getCopyBuf() []byte {
|
||
return copyBufPool.Get().(*[copyBufPoolSize]byte)[:]
|
||
}
|
||
func putCopyBuf(b []byte) {
|
||
if len(b) != copyBufPoolSize {
|
||
panic("trying to put back buffer of the wrong size in the copyBufPool")
|
||
}
|
||
copyBufPool.Put((*[copyBufPoolSize]byte)(b))
|
||
}
|
||
|
||
func bufioWriterPool(size int) *sync.Pool {
|
||
switch size {
|
||
case 2 << 10:
|
||
return &bufioWriter2kPool
|
||
case 4 << 10:
|
||
return &bufioWriter4kPool
|
||
}
|
||
return nil
|
||
}
|
||
|
||
// newBufioReader should be an internal detail,
|
||
// but widely used packages access it using linkname.
|
||
// Notable members of the hall of shame include:
|
||
// - github.com/gobwas/ws
|
||
//
|
||
// Do not remove or change the type signature.
|
||
// See go.dev/issue/67401.
|
||
//
|
||
//go:linkname newBufioReader
|
||
func newBufioReader(r io.Reader) *bufio.Reader {
|
||
if v := bufioReaderPool.Get(); v != nil {
|
||
br := v.(*bufio.Reader)
|
||
br.Reset(r)
|
||
return br
|
||
}
|
||
// Note: if this reader size is ever changed, update
|
||
// TestHandlerBodyClose's assumptions.
|
||
return bufio.NewReader(r)
|
||
}
|
||
|
||
// putBufioReader should be an internal detail,
|
||
// but widely used packages access it using linkname.
|
||
// Notable members of the hall of shame include:
|
||
// - github.com/gobwas/ws
|
||
//
|
||
// Do not remove or change the type signature.
|
||
// See go.dev/issue/67401.
|
||
//
|
||
//go:linkname putBufioReader
|
||
func putBufioReader(br *bufio.Reader) {
|
||
br.Reset(nil)
|
||
bufioReaderPool.Put(br)
|
||
}
|
||
|
||
// newBufioWriterSize should be an internal detail,
|
||
// but widely used packages access it using linkname.
|
||
// Notable members of the hall of shame include:
|
||
// - github.com/gobwas/ws
|
||
//
|
||
// Do not remove or change the type signature.
|
||
// See go.dev/issue/67401.
|
||
//
|
||
//go:linkname newBufioWriterSize
|
||
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)
|
||
}
|
||
|
||
// putBufioWriter should be an internal detail,
|
||
// but widely used packages access it using linkname.
|
||
// Notable members of the hall of shame include:
|
||
// - github.com/gobwas/ws
|
||
//
|
||
// Do not remove or change the type signature.
|
||
// See go.dev/issue/67401.
|
||
//
|
||
//go:linkname putBufioWriter
|
||
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) initialReadLimitSize() int64 {
|
||
return int64(srv.maxHeaderBytes()) + 4096 // bufio slop
|
||
}
|
||
|
||
// tlsHandshakeTimeout returns the time limit permitted for the TLS
|
||
// handshake, or zero for unlimited.
|
||
//
|
||
// It returns the minimum of any positive ReadHeaderTimeout,
|
||
// ReadTimeout, or WriteTimeout.
|
||
func (srv *Server) tlsHandshakeTimeout() time.Duration {
|
||
var ret time.Duration
|
||
for _, v := range [...]time.Duration{
|
||
srv.ReadHeaderTimeout,
|
||
srv.ReadTimeout,
|
||
srv.WriteTimeout,
|
||
} {
|
||
if v <= 0 {
|
||
continue
|
||
}
|
||
if ret == 0 || v < ret {
|
||
ret = v
|
||
}
|
||
}
|
||
return ret
|
||
}
|
||
|
||
// wrapper around io.ReadCloser which on first read, sends an
|
||
// HTTP/1.1 100 Continue header
|
||
type expectContinueReader struct {
|
||
resp *response
|
||
readCloser io.ReadCloser
|
||
closed atomic.Bool
|
||
sawEOF atomic.Bool
|
||
}
|
||
|
||
func (ecr *expectContinueReader) Read(p []byte) (n int, err error) {
|
||
if ecr.closed.Load() {
|
||
return 0, ErrBodyReadAfterClose
|
||
}
|
||
w := ecr.resp
|
||
if w.canWriteContinue.Load() {
|
||
w.writeContinueMu.Lock()
|
||
if w.canWriteContinue.Load() {
|
||
w.conn.bufw.WriteString("HTTP/1.1 100 Continue\r\n\r\n")
|
||
w.conn.bufw.Flush()
|
||
w.canWriteContinue.Store(false)
|
||
}
|
||
w.writeContinueMu.Unlock()
|
||
}
|
||
n, err = ecr.readCloser.Read(p)
|
||
if err == io.EOF {
|
||
ecr.sawEOF.Store(true)
|
||
}
|
||
return
|
||
}
|
||
|
||
func (ecr *expectContinueReader) Close() error {
|
||
ecr.closed.Store(true)
|
||
return ecr.readCloser.Close()
|
||
}
|
||
|
||
// TimeFormat is the time format to use when generating times in HTTP
|
||
// headers. It is like [time.RFC1123] but hard-codes GMT as the time
|
||
// zone. The time being formatted must be in UTC for Format to
|
||
// generate the correct format.
|
||
//
|
||
// For parsing this time format, see [ParseTime].
|
||
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(ctx context.Context) (w *response, err error) {
|
||
if c.hijacked() {
|
||
return nil, ErrHijacked
|
||
}
|
||
|
||
var (
|
||
wholeReqDeadline time.Time // or zero if none
|
||
hdrDeadline time.Time // or zero if none
|
||
)
|
||
t0 := time.Now()
|
||
if d := c.server.readHeaderTimeout(); d > 0 {
|
||
hdrDeadline = t0.Add(d)
|
||
}
|
||
if d := c.server.ReadTimeout; d > 0 {
|
||
wholeReqDeadline = t0.Add(d)
|
||
}
|
||
c.rwc.SetReadDeadline(hdrDeadline)
|
||
if d := c.server.WriteTimeout; d > 0 {
|
||
defer func() {
|
||
c.rwc.SetWriteDeadline(time.Now().Add(d))
|
||
}()
|
||
}
|
||
|
||
c.r.setReadLimit(c.server.initialReadLimitSize())
|
||
if c.lastMethod == "POST" {
|
||
// RFC 7230 section 3 tolerance for old buggy clients.
|
||
peek, _ := c.bufr.Peek(4) // ReadRequest will get err below
|
||
c.bufr.Discard(numLeadingCRorLF(peek))
|
||
}
|
||
req, err := readRequest(c.bufr)
|
||
if err != nil {
|
||
if c.r.hitReadLimit() {
|
||
return nil, errTooLarge
|
||
}
|
||
return nil, err
|
||
}
|
||
|
||
if !http1ServerSupportsRequest(req) {
|
||
return nil, statusError{StatusHTTPVersionNotSupported, "unsupported protocol version"}
|
||
}
|
||
|
||
c.lastMethod = req.Method
|
||
c.r.setInfiniteReadLimit()
|
||
|
||
hosts, haveHost := req.Header["Host"]
|
||
isH2Upgrade := req.isH2Upgrade()
|
||
if req.ProtoAtLeast(1, 1) && (!haveHost || len(hosts) == 0) && !isH2Upgrade && req.Method != "CONNECT" {
|
||
return nil, badRequestError("missing required Host header")
|
||
}
|
||
if len(hosts) == 1 && !httpguts.ValidHostHeader(hosts[0]) {
|
||
return nil, badRequestError("malformed Host header")
|
||
}
|
||
for k, vv := range req.Header {
|
||
if !httpguts.ValidHeaderFieldName(k) {
|
||
return nil, badRequestError("invalid header name")
|
||
}
|
||
for _, v := range vv {
|
||
if !httpguts.ValidHeaderFieldValue(v) {
|
||
return nil, badRequestError("invalid header value")
|
||
}
|
||
}
|
||
}
|
||
delete(req.Header, "Host")
|
||
|
||
ctx, cancelCtx := context.WithCancel(ctx)
|
||
req.ctx = ctx
|
||
req.RemoteAddr = c.remoteAddr
|
||
req.TLS = c.tlsState
|
||
if body, ok := req.Body.(*body); ok {
|
||
body.doEarlyClose = true
|
||
}
|
||
|
||
// Adjust the read deadline if necessary.
|
||
if !hdrDeadline.Equal(wholeReqDeadline) {
|
||
c.rwc.SetReadDeadline(wholeReqDeadline)
|
||
}
|
||
|
||
w = &response{
|
||
conn: c,
|
||
cancelCtx: cancelCtx,
|
||
req: req,
|
||
reqBody: req.Body,
|
||
handlerHeader: make(Header),
|
||
contentLength: -1,
|
||
closeNotifyCh: make(chan bool, 1),
|
||
|
||
// We populate these ahead of time so we're not
|
||
// reading from req.Header after their Handler starts
|
||
// and maybe mutates it (Issue 14940)
|
||
wants10KeepAlive: req.wantsHttp10KeepAlive(),
|
||
wantsClose: req.wantsClose(),
|
||
}
|
||
if isH2Upgrade {
|
||
w.closeAfterReply = true
|
||
}
|
||
w.cw.res = w
|
||
w.w = newBufioWriterSize(&w.cw, bufferBeforeChunkingSize)
|
||
return w, nil
|
||
}
|
||
|
||
// http1ServerSupportsRequest reports whether Go's HTTP/1.x server
|
||
// supports the given request.
|
||
func http1ServerSupportsRequest(req *Request) bool {
|
||
if req.ProtoMajor == 1 {
|
||
return true
|
||
}
|
||
// Accept "PRI * HTTP/2.0" upgrade requests, so Handlers can
|
||
// wire up their own HTTP/2 upgrades.
|
||
if req.ProtoMajor == 2 && req.ProtoMinor == 0 &&
|
||
req.Method == "PRI" && req.RequestURI == "*" {
|
||
return true
|
||
}
|
||
// Reject HTTP/0.x, and all other HTTP/2+ requests (which
|
||
// aren't encoded in ASCII anyway).
|
||
return false
|
||
}
|
||
|
||
func (w *response) Header() Header {
|
||
if w.cw.header == nil && w.wroteHeader && !w.cw.wroteHeader {
|
||
// Accessing the header between logically writing it
|
||
// and physically writing it means we need to allocate
|
||
// a clone to snapshot the logically written state.
|
||
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, 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 checkWriteHeaderCode(code int) {
|
||
// Issue 22880: require valid WriteHeader status codes.
|
||
// For now we only enforce that it's three digits.
|
||
// In the future we might block things over 599 (600 and above aren't defined
|
||
// at https://httpwg.org/specs/rfc7231.html#status.codes).
|
||
// But for now any three digits.
|
||
//
|
||
// We used to send "HTTP/1.1 000 0" on the wire in responses but there's
|
||
// no equivalent bogus thing we can realistically send in HTTP/2,
|
||
// so we'll consistently panic instead and help people find their bugs
|
||
// early. (We can't return an error from WriteHeader even if we wanted to.)
|
||
if code < 100 || code > 999 {
|
||
panic(fmt.Sprintf("invalid WriteHeader code %v", code))
|
||
}
|
||
}
|
||
|
||
// relevantCaller searches the call stack for the first function outside of net/http.
|
||
// The purpose of this function is to provide more helpful error messages.
|
||
func relevantCaller() runtime.Frame {
|
||
pc := make([]uintptr, 16)
|
||
n := runtime.Callers(1, pc)
|
||
frames := runtime.CallersFrames(pc[:n])
|
||
var frame runtime.Frame
|
||
for {
|
||
frame, more := frames.Next()
|
||
if !strings.HasPrefix(frame.Function, "net/http.") {
|
||
return frame
|
||
}
|
||
if !more {
|
||
break
|
||
}
|
||
}
|
||
return frame
|
||
}
|
||
|
||
func (w *response) WriteHeader(code int) {
|
||
if w.conn.hijacked() {
|
||
caller := relevantCaller()
|
||
w.conn.server.logf("http: response.WriteHeader on hijacked connection from %s (%s:%d)", caller.Function, path.Base(caller.File), caller.Line)
|
||
return
|
||
}
|
||
if w.wroteHeader {
|
||
caller := relevantCaller()
|
||
w.conn.server.logf("http: superfluous response.WriteHeader call from %s (%s:%d)", caller.Function, path.Base(caller.File), caller.Line)
|
||
return
|
||
}
|
||
checkWriteHeaderCode(code)
|
||
|
||
if code < 101 || code > 199 {
|
||
// Sending a 100 Continue or any non-1xx header disables the
|
||
// automatically-sent 100 Continue from Request.Body.Read.
|
||
w.disableWriteContinue()
|
||
}
|
||
|
||
// Handle informational headers.
|
||
//
|
||
// We shouldn't send any further headers after 101 Switching Protocols,
|
||
// so it takes the non-informational path.
|
||
if code >= 100 && code <= 199 && code != StatusSwitchingProtocols {
|
||
writeStatusLine(w.conn.bufw, w.req.ProtoAtLeast(1, 1), code, w.statusBuf[:])
|
||
|
||
// Per RFC 8297 we must not clear the current header map
|
||
w.handlerHeader.WriteSubset(w.conn.bufw, excludedHeadersNoBody)
|
||
w.conn.bufw.Write(crlf)
|
||
w.conn.bufw.Flush()
|
||
|
||
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.bufw.
|
||
//
|
||
// 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 is written out to w.conn.buf below. Depending on the
|
||
// state of the handler, we either own the map or not. If we
|
||
// don't own it, the exclude map is created lazily for
|
||
// WriteSubset to remove headers. The setHeader struct holds
|
||
// headers we need to add.
|
||
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
|
||
|
||
// Don't write out the fake "Trailer:foo" keys. See TrailerPrefix.
|
||
trailers := false
|
||
for k := range cw.header {
|
||
if strings.HasPrefix(k, TrailerPrefix) {
|
||
if excludeHeader == nil {
|
||
excludeHeader = make(map[string]bool)
|
||
}
|
||
excludeHeader[k] = true
|
||
trailers = true
|
||
}
|
||
}
|
||
for _, v := range cw.header["Trailer"] {
|
||
trailers = true
|
||
foreachHeaderElement(v, cw.res.declareTrailer)
|
||
}
|
||
|
||
te := header.get("Transfer-Encoding")
|
||
hasTE := te != ""
|
||
|
||
// If the handler is done but never sent a Content-Length
|
||
// response header and this is our first (and last) write, set
|
||
// it, even to zero. This helps HTTP/1.0 clients keep their
|
||
// "keep-alive" connections alive.
|
||
// Exceptions: 304/204/1xx responses never get Content-Length, and if
|
||
// it was a HEAD request, we don't know the difference between
|
||
// 0 actual bytes and 0 bytes because the handler noticed it
|
||
// was a HEAD request and chose not to write anything. So for
|
||
// HEAD, the handler should either write the Content-Length or
|
||
// write non-zero bytes. If it's actually 0 bytes and the
|
||
// handler never looked at the Request.Method, we just don't
|
||
// send a Content-Length header.
|
||
// Further, we don't send an automatic Content-Length if they
|
||
// set a Transfer-Encoding, because they're generally incompatible.
|
||
if w.handlerDone.Load() && !trailers && !hasTE && bodyAllowedForStatus(w.status) && !header.has("Content-Length") && (!isHEAD || len(p) > 0) {
|
||
w.contentLength = int64(len(p))
|
||
setHeader.contentLength = strconv.AppendInt(cw.res.clenBuf[:0], int64(len(p)), 10)
|
||
}
|
||
|
||
// If this was an HTTP/1.0 request with keep-alive and we sent a
|
||
// Content-Length back, we can make this a keep-alive response ...
|
||
if w.wants10KeepAlive && keepAlivesEnabled {
|
||
sentLength := header.get("Content-Length") != ""
|
||
if sentLength && header.get("Connection") == "keep-alive" {
|
||
w.closeAfterReply = false
|
||
}
|
||
}
|
||
|
||
// Check for an explicit (and valid) Content-Length header.
|
||
hasCL := w.contentLength != -1
|
||
|
||
if w.wants10KeepAlive && (isHEAD || hasCL || !bodyAllowedForStatus(w.status)) {
|
||
_, connectionHeaderSet := header["Connection"]
|
||
if !connectionHeaderSet {
|
||
setHeader.connection = "keep-alive"
|
||
}
|
||
} else if !w.req.ProtoAtLeast(1, 1) || w.wantsClose {
|
||
w.closeAfterReply = true
|
||
}
|
||
|
||
if header.get("Connection") == "close" || !keepAlivesEnabled {
|
||
w.closeAfterReply = true
|
||
}
|
||
|
||
// If the client wanted a 100-continue but we never sent it to
|
||
// them (or, more strictly: we never finished reading their
|
||
// request body), don't reuse this connection because it's now
|
||
// in an unknown state: we might be sending this response at
|
||
// the same time the client is now sending its request body
|
||
// after a timeout. (Some HTTP clients send Expect:
|
||
// 100-continue but knowing that some servers don't support
|
||
// it, the clients set a timer and send the body later anyway)
|
||
// If we haven't seen EOF, we can't skip over the unread body
|
||
// because we don't know if the next bytes on the wire will be
|
||
// the body-following-the-timer or the subsequent request.
|
||
// See Issue 11549.
|
||
if ecr, ok := w.req.Body.(*expectContinueReader); ok && !ecr.sawEOF.Load() {
|
||
w.closeAfterReply = true
|
||
}
|
||
|
||
// We do this by default because there are a number of clients that
|
||
// send a full request before starting to read the response, and they
|
||
// can deadlock if we start writing the response with unconsumed body
|
||
// remaining. See Issue 15527 for some history.
|
||
//
|
||
// If full duplex mode has been enabled with ResponseController.EnableFullDuplex,
|
||
// then leave the request body alone.
|
||
//
|
||
// We don't take this path when w.closeAfterReply is set.
|
||
// We may not need to consume the request to get ready for the next one
|
||
// (since we're closing the conn), but a client which sends a full request
|
||
// before reading a response may deadlock in this case.
|
||
// This behavior has been present since CL 5268043 (2011), however,
|
||
// so it doesn't seem to be causing problems.
|
||
if w.req.ContentLength != 0 && !w.closeAfterReply && !w.fullDuplex {
|
||
var discard, tooBig bool
|
||
|
||
switch bdy := w.req.Body.(type) {
|
||
case *expectContinueReader:
|
||
// We only get here if we have already fully consumed the request body
|
||
// (see above).
|
||
case *body:
|
||
bdy.mu.Lock()
|
||
switch {
|
||
case bdy.closed:
|
||
if !bdy.sawEOF {
|
||
// Body was closed in handler with non-EOF error.
|
||
w.closeAfterReply = true
|
||
}
|
||
case bdy.unreadDataSizeLocked() >= maxPostHandlerReadBytes:
|
||
tooBig = true
|
||
default:
|
||
discard = true
|
||
}
|
||
bdy.mu.Unlock()
|
||
default:
|
||
discard = true
|
||
}
|
||
|
||
if discard {
|
||
_, err := io.CopyN(io.Discard, w.reqBody, maxPostHandlerReadBytes+1)
|
||
switch err {
|
||
case nil:
|
||
// There must be even more data left over.
|
||
tooBig = true
|
||
case ErrBodyReadAfterClose:
|
||
// Body was already consumed and closed.
|
||
case io.EOF:
|
||
// The remaining body was just consumed, close it.
|
||
err = w.reqBody.Close()
|
||
if err != nil {
|
||
w.closeAfterReply = true
|
||
}
|
||
default:
|
||
// Some other kind of error occurred, like a read timeout, or
|
||
// corrupt chunked encoding. In any case, whatever remains
|
||
// on the wire must not be parsed as another HTTP request.
|
||
w.closeAfterReply = true
|
||
}
|
||
}
|
||
|
||
if tooBig {
|
||
w.requestTooLarge()
|
||
delHeader("Connection")
|
||
setHeader.connection = "close"
|
||
}
|
||
}
|
||
|
||
code := w.status
|
||
if bodyAllowedForStatus(code) {
|
||
// If no content type, apply sniffing algorithm to body.
|
||
_, haveType := header["Content-Type"]
|
||
|
||
// If the Content-Encoding was set and is non-blank,
|
||
// we shouldn't sniff the body. See Issue 31753.
|
||
ce := header.Get("Content-Encoding")
|
||
hasCE := len(ce) > 0
|
||
if !hasCE && !haveType && !hasTE && len(p) > 0 {
|
||
setHeader.contentType = DetectContentType(p)
|
||
}
|
||
} else {
|
||
for _, k := range suppressedHeaders(code) {
|
||
delHeader(k)
|
||
}
|
||
}
|
||
|
||
if !header.has("Date") {
|
||
setHeader.date = appendTime(cw.res.dateBuf[:0], time.Now())
|
||
}
|
||
|
||
if hasCL && hasTE && te != "identity" {
|
||
// TODO: return an error if WriteHeader gets a return parameter
|
||
// For now just ignore the Content-Length.
|
||
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) || code == StatusNoContent {
|
||
// Response has no body.
|
||
delHeader("Transfer-Encoding")
|
||
} else if hasCL {
|
||
// Content-Length has been provided, so no chunking is to be done.
|
||
delHeader("Transfer-Encoding")
|
||
} else if w.req.ProtoAtLeast(1, 1) {
|
||
// HTTP/1.1 or greater: Transfer-Encoding has been set to identity, and no
|
||
// content-length has been provided. The connection must be closed after the
|
||
// reply is written, and no chunking is to be done. This is the setup
|
||
// recommended in the Server-Sent Events candidate recommendation 11,
|
||
// section 8.
|
||
if hasTE && te == "identity" {
|
||
cw.chunking = false
|
||
w.closeAfterReply = true
|
||
delHeader("Transfer-Encoding")
|
||
} else {
|
||
// HTTP/1.1 or greater: use chunked transfer encoding
|
||
// to avoid closing the connection at EOF.
|
||
cw.chunking = true
|
||
setHeader.transferEncoding = "chunked"
|
||
if hasTE && te == "chunked" {
|
||
// We will send the chunked Transfer-Encoding header later.
|
||
delHeader("Transfer-Encoding")
|
||
}
|
||
}
|
||
} else {
|
||
// HTTP version < 1.1: cannot do chunked transfer
|
||
// encoding and we don't know the Content-Length so
|
||
// signal EOF by closing connection.
|
||
w.closeAfterReply = true
|
||
delHeader("Transfer-Encoding") // in case already set
|
||
}
|
||
|
||
// Cannot use Content-Length with non-identity Transfer-Encoding.
|
||
if cw.chunking {
|
||
delHeader("Content-Length")
|
||
}
|
||
if !w.req.ProtoAtLeast(1, 0) {
|
||
return
|
||
}
|
||
|
||
// Only override the Connection header if it is not a successful
|
||
// protocol switch response and if KeepAlives are not enabled.
|
||
// See https://golang.org/issue/36381.
|
||
delConnectionHeader := w.closeAfterReply &&
|
||
(!keepAlivesEnabled || !hasToken(cw.header.get("Connection"), "close")) &&
|
||
!isProtocolSwitchResponse(w.status, header)
|
||
if delConnectionHeader {
|
||
delHeader("Connection")
|
||
if w.req.ProtoAtLeast(1, 1) {
|
||
setHeader.connection = "close"
|
||
}
|
||
}
|
||
|
||
writeStatusLine(w.conn.bufw, w.req.ProtoAtLeast(1, 1), code, w.statusBuf[:])
|
||
cw.header.WriteSubset(w.conn.bufw, excludeHeader)
|
||
setHeader.Write(w.conn.bufw)
|
||
w.conn.bufw.Write(crlf)
|
||
}
|
||
|
||
// foreachHeaderElement splits v according to the "#rule" construction
|
||
// in RFC 7230 section 7 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)
|
||
}
|
||
}
|
||
}
|
||
|
||
// writeStatusLine writes an HTTP/1.x Status-Line (RFC 7230 Section 3.1.2)
|
||
// to bw. is11 is whether the HTTP request is HTTP/1.1. false means HTTP/1.0.
|
||
// code is the response status code.
|
||
// scratch is an optional scratch buffer. If it has at least capacity 3, it's used.
|
||
func writeStatusLine(bw *bufio.Writer, is11 bool, code int, scratch []byte) {
|
||
if is11 {
|
||
bw.WriteString("HTTP/1.1 ")
|
||
} else {
|
||
bw.WriteString("HTTP/1.0 ")
|
||
}
|
||
if text := StatusText(code); text != "" {
|
||
bw.Write(strconv.AppendInt(scratch[:0], int64(code), 10))
|
||
bw.WriteByte(' ')
|
||
bw.WriteString(text)
|
||
bw.WriteString("\r\n")
|
||
} else {
|
||
// don't worry about performance
|
||
fmt.Fprintf(bw, "%03d status code %d\r\n", code, code)
|
||
}
|
||
}
|
||
|
||
// 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.bufw, 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() {
|
||
if lenData > 0 {
|
||
caller := relevantCaller()
|
||
w.conn.server.logf("http: response.Write on hijacked connection from %s (%s:%d)", caller.Function, path.Base(caller.File), caller.Line)
|
||
}
|
||
return 0, ErrHijacked
|
||
}
|
||
|
||
if w.canWriteContinue.Load() {
|
||
// Body reader wants to write 100 Continue but hasn't yet. Tell it not to.
|
||
w.disableWriteContinue()
|
||
}
|
||
|
||
if !w.wroteHeader {
|
||
w.WriteHeader(StatusOK)
|
||
}
|
||
if lenData == 0 {
|
||
return 0, nil
|
||
}
|
||
if !w.bodyAllowed() {
|
||
return 0, ErrBodyNotAllowed
|
||
}
|
||
|
||
w.written += int64(lenData) // ignoring errors, for errorKludge
|
||
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.Store(true)
|
||
|
||
if !w.wroteHeader {
|
||
w.WriteHeader(StatusOK)
|
||
}
|
||
|
||
w.w.Flush()
|
||
putBufioWriter(w.w)
|
||
w.cw.close()
|
||
w.conn.bufw.Flush()
|
||
|
||
w.conn.r.abortPendingRead()
|
||
|
||
// Close the body (regardless of w.closeAfterReply) so we can
|
||
// re-use its bufio.Reader later safely.
|
||
w.reqBody.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 {
|
||
// The request or something set while executing the
|
||
// handler indicated we shouldn't reuse this
|
||
// connection.
|
||
return false
|
||
}
|
||
|
||
if w.req.Method != "HEAD" && w.contentLength != -1 && w.bodyAllowed() && w.contentLength != w.written {
|
||
// Did not write enough. Avoid getting out of sync.
|
||
return false
|
||
}
|
||
|
||
// There was some error writing to the underlying connection
|
||
// during the request, so don't re-use this conn.
|
||
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() {
|
||
w.FlushError()
|
||
}
|
||
|
||
func (w *response) FlushError() error {
|
||
if !w.wroteHeader {
|
||
w.WriteHeader(StatusOK)
|
||
}
|
||
err := w.w.Flush()
|
||
e2 := w.cw.flush()
|
||
if err == nil {
|
||
err = e2
|
||
}
|
||
return err
|
||
}
|
||
|
||
func (c *conn) finalFlush() {
|
||
if c.bufr != nil {
|
||
// Steal the bufio.Reader (~4KB worth of memory) and its associated
|
||
// reader for a future connection.
|
||
putBufioReader(c.bufr)
|
||
c.bufr = nil
|
||
}
|
||
|
||
if c.bufw != nil {
|
||
c.bufw.Flush()
|
||
// Steal the bufio.Writer (~4KB worth of memory) and its associated
|
||
// writer for a future connection.
|
||
putBufioWriter(c.bufw)
|
||
c.bufw = nil
|
||
}
|
||
}
|
||
|
||
// Close the connection.
|
||
func (c *conn) close() {
|
||
c.finalFlush()
|
||
c.rwc.Close()
|
||
}
|
||
|
||
// 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),
|
||
// and may be modified by tests.
|
||
//
|
||
// TODO(bcmills): This should arguably be a server configuration parameter,
|
||
// not a hard-coded value.
|
||
var rstAvoidanceDelay = 500 * time.Millisecond
|
||
|
||
type closeWriter interface {
|
||
CloseWrite() error
|
||
}
|
||
|
||
var _ closeWriter = (*net.TCPConn)(nil)
|
||
|
||
// closeWriteAndWait flushes any outstanding data and sends a FIN packet (if
|
||
// client is connected via TCP), signaling 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()
|
||
}
|
||
|
||
// When we return from closeWriteAndWait, the caller will fully close the
|
||
// connection. If client is still writing to the connection, this will cause
|
||
// the write to fail with ECONNRESET or similar. Unfortunately, many TCP
|
||
// implementations will also drop unread packets from the client's read buffer
|
||
// when a write fails, causing our final response to be truncated away too.
|
||
//
|
||
// As a result, https://www.rfc-editor.org/rfc/rfc7230#section-6.6 recommends
|
||
// that “[t]he server … continues to read from the connection until it
|
||
// receives a corresponding close by the client, or until the server is
|
||
// reasonably certain that its own TCP stack has received the client's
|
||
// acknowledgement of the packet(s) containing the server's last response.”
|
||
//
|
||
// Unfortunately, we have no straightforward way to be “reasonably certain”
|
||
// that we have received the client's ACK, and at any rate we don't want to
|
||
// allow a misbehaving client to soak up server connections indefinitely by
|
||
// withholding an ACK, nor do we want to go through the complexity or overhead
|
||
// of using low-level APIs to figure out when a TCP round-trip has completed.
|
||
//
|
||
// Instead, we declare that we are “reasonably certain” that we received the
|
||
// ACK if maxRSTAvoidanceDelay has elapsed.
|
||
time.Sleep(rstAvoidanceDelay)
|
||
}
|
||
|
||
// validNextProto reports whether the proto is a valid ALPN protocol name.
|
||
// Everything is valid except the empty string and built-in protocol types,
|
||
// so that those can't be overridden with alternate implementations.
|
||
func validNextProto(proto string) bool {
|
||
switch proto {
|
||
case "", "http/1.1", "http/1.0":
|
||
return false
|
||
}
|
||
return true
|
||
}
|
||
|
||
const (
|
||
runHooks = true
|
||
skipHooks = false
|
||
)
|
||
|
||
func (c *conn) setState(nc net.Conn, state ConnState, runHook bool) {
|
||
srv := c.server
|
||
switch state {
|
||
case StateNew:
|
||
srv.trackConn(c, true)
|
||
case StateHijacked, StateClosed:
|
||
srv.trackConn(c, false)
|
||
}
|
||
if state > 0xff || state < 0 {
|
||
panic("internal error")
|
||
}
|
||
packedState := uint64(time.Now().Unix()<<8) | uint64(state)
|
||
c.curState.Store(packedState)
|
||
if !runHook {
|
||
return
|
||
}
|
||
if hook := srv.ConnState; hook != nil {
|
||
hook(nc, state)
|
||
}
|
||
}
|
||
|
||
func (c *conn) getState() (state ConnState, unixSec int64) {
|
||
packedState := c.curState.Load()
|
||
return ConnState(packedState & 0xff), int64(packedState >> 8)
|
||
}
|
||
|
||
// badRequestError is a literal string (used by in the server in HTML,
|
||
// unescaped) to tell the user why their request was bad. It should
|
||
// be plain text without user info or other embedded errors.
|
||
func badRequestError(e string) error { return statusError{StatusBadRequest, e} }
|
||
|
||
// statusError is an error used to respond to a request with an HTTP status.
|
||
// The text should be plain text without user info or other embedded errors.
|
||
type statusError struct {
|
||
code int
|
||
text string
|
||
}
|
||
|
||
func (e statusError) Error() string { return StatusText(e.code) + ": " + e.text }
|
||
|
||
// ErrAbortHandler is a sentinel panic value to abort a handler.
|
||
// While any panic from ServeHTTP aborts the response to the client,
|
||
// panicking with ErrAbortHandler also suppresses logging of a stack
|
||
// trace to the server's error log.
|
||
var ErrAbortHandler = errors.New("net/http: abort Handler")
|
||
|
||
// isCommonNetReadError reports whether err is a common error
|
||
// encountered during reading a request off the network when the
|
||
// client has gone away or had its read fail somehow. This is used to
|
||
// determine which logs are interesting enough to log about.
|
||
func isCommonNetReadError(err error) bool {
|
||
if err == io.EOF {
|
||
return true
|
||
}
|
||
if neterr, ok := err.(net.Error); ok && neterr.Timeout() {
|
||
return true
|
||
}
|
||
if oe, ok := err.(*net.OpError); ok && oe.Op == "read" {
|
||
return true
|
||
}
|
||
return false
|
||
}
|
||
|
||
// Serve a new connection.
|
||
func (c *conn) serve(ctx context.Context) {
|
||
if ra := c.rwc.RemoteAddr(); ra != nil {
|
||
c.remoteAddr = ra.String()
|
||
}
|
||
ctx = context.WithValue(ctx, LocalAddrContextKey, c.rwc.LocalAddr())
|
||
var inFlightResponse *response
|
||
defer func() {
|
||
if err := recover(); err != nil && err != ErrAbortHandler {
|
||
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 inFlightResponse != nil {
|
||
inFlightResponse.cancelCtx()
|
||
inFlightResponse.disableWriteContinue()
|
||
}
|
||
if !c.hijacked() {
|
||
if inFlightResponse != nil {
|
||
inFlightResponse.conn.r.abortPendingRead()
|
||
inFlightResponse.reqBody.Close()
|
||
}
|
||
c.close()
|
||
c.setState(c.rwc, StateClosed, runHooks)
|
||
}
|
||
}()
|
||
|
||
if tlsConn, ok := c.rwc.(*tls.Conn); ok {
|
||
tlsTO := c.server.tlsHandshakeTimeout()
|
||
if tlsTO > 0 {
|
||
dl := time.Now().Add(tlsTO)
|
||
c.rwc.SetReadDeadline(dl)
|
||
c.rwc.SetWriteDeadline(dl)
|
||
}
|
||
if err := tlsConn.HandshakeContext(ctx); err != nil {
|
||
// If the handshake failed due to the client not speaking
|
||
// TLS, assume they're speaking plaintext HTTP and write a
|
||
// 400 response on the TLS conn's underlying net.Conn.
|
||
var reason string
|
||
if re, ok := err.(tls.RecordHeaderError); ok && re.Conn != nil && tlsRecordHeaderLooksLikeHTTP(re.RecordHeader) {
|
||
io.WriteString(re.Conn, "HTTP/1.0 400 Bad Request\r\n\r\nClient sent an HTTP request to an HTTPS server.\n")
|
||
re.Conn.Close()
|
||
reason = "client sent an HTTP request to an HTTPS server"
|
||
} else {
|
||
reason = err.Error()
|
||
}
|
||
c.server.logf("http: TLS handshake error from %s: %v", c.rwc.RemoteAddr(), reason)
|
||
return
|
||
}
|
||
// Restore Conn-level deadlines.
|
||
if tlsTO > 0 {
|
||
c.rwc.SetReadDeadline(time.Time{})
|
||
c.rwc.SetWriteDeadline(time.Time{})
|
||
}
|
||
c.tlsState = new(tls.ConnectionState)
|
||
*c.tlsState = tlsConn.ConnectionState()
|
||
if proto := c.tlsState.NegotiatedProtocol; validNextProto(proto) {
|
||
if fn := c.server.TLSNextProto[proto]; fn != nil {
|
||
h := initALPNRequest{ctx, tlsConn, serverHandler{c.server}}
|
||
// Mark freshly created HTTP/2 as active and prevent any server state hooks
|
||
// from being run on these connections. This prevents closeIdleConns from
|
||
// closing such connections. See issue https://golang.org/issue/39776.
|
||
c.setState(c.rwc, StateActive, skipHooks)
|
||
fn(c.server, tlsConn, h)
|
||
}
|
||
return
|
||
}
|
||
}
|
||
|
||
// HTTP/1.x from here on.
|
||
|
||
ctx, cancelCtx := context.WithCancel(ctx)
|
||
c.cancelCtx = cancelCtx
|
||
defer cancelCtx()
|
||
|
||
c.r = &connReader{conn: c}
|
||
c.bufr = newBufioReader(c.r)
|
||
c.bufw = newBufioWriterSize(checkConnErrorWriter{c}, 4<<10)
|
||
|
||
for {
|
||
w, err := c.readRequest(ctx)
|
||
if c.r.remain != c.server.initialReadLimitSize() {
|
||
// If we read any bytes off the wire, we're active.
|
||
c.setState(c.rwc, StateActive, runHooks)
|
||
}
|
||
if err != nil {
|
||
const errorHeaders = "\r\nContent-Type: text/plain; charset=utf-8\r\nConnection: close\r\n\r\n"
|
||
|
||
switch {
|
||
case err == errTooLarge:
|
||
// Their HTTP client may or may not be
|
||
// able to read this if we're
|
||
// responding to them and hanging up
|
||
// while they're still writing their
|
||
// request. Undefined behavior.
|
||
const publicErr = "431 Request Header Fields Too Large"
|
||
fmt.Fprintf(c.rwc, "HTTP/1.1 "+publicErr+errorHeaders+publicErr)
|
||
c.closeWriteAndWait()
|
||
return
|
||
|
||
case isUnsupportedTEError(err):
|
||
// Respond as per RFC 7230 Section 3.3.1 which says,
|
||
// A server that receives a request message with a
|
||
// transfer coding it does not understand SHOULD
|
||
// respond with 501 (Unimplemented).
|
||
code := StatusNotImplemented
|
||
|
||
// We purposefully aren't echoing back the transfer-encoding's value,
|
||
// so as to mitigate the risk of cross side scripting by an attacker.
|
||
fmt.Fprintf(c.rwc, "HTTP/1.1 %d %s%sUnsupported transfer encoding", code, StatusText(code), errorHeaders)
|
||
return
|
||
|
||
case isCommonNetReadError(err):
|
||
return // don't reply
|
||
|
||
default:
|
||
if v, ok := err.(statusError); ok {
|
||
fmt.Fprintf(c.rwc, "HTTP/1.1 %d %s: %s%s%d %s: %s", v.code, StatusText(v.code), v.text, errorHeaders, v.code, StatusText(v.code), v.text)
|
||
return
|
||
}
|
||
const publicErr = "400 Bad Request"
|
||
fmt.Fprintf(c.rwc, "HTTP/1.1 "+publicErr+errorHeaders+publicErr)
|
||
return
|
||
}
|
||
}
|
||
|
||
// Expect 100 Continue support
|
||
req := w.req
|
||
if req.expectsContinue() {
|
||
if req.ProtoAtLeast(1, 1) && req.ContentLength != 0 {
|
||
// Wrap the Body reader with one that replies on the connection
|
||
req.Body = &expectContinueReader{readCloser: req.Body, resp: w}
|
||
w.canWriteContinue.Store(true)
|
||
}
|
||
} else if req.Header.get("Expect") != "" {
|
||
w.sendExpectationFailed()
|
||
return
|
||
}
|
||
|
||
c.curReq.Store(w)
|
||
|
||
if requestBodyRemains(req.Body) {
|
||
registerOnHitEOF(req.Body, w.conn.r.startBackgroundRead)
|
||
} else {
|
||
w.conn.r.startBackgroundRead()
|
||
}
|
||
|
||
// HTTP cannot have multiple simultaneous active requests.[*]
|
||
// Until the server replies to this request, it can't read another,
|
||
// so we might as well run the handler in this goroutine.
|
||
// [*] Not strictly true: HTTP pipelining. We could let them all process
|
||
// in parallel even if their responses need to be serialized.
|
||
// But we're not going to implement HTTP pipelining because it
|
||
// was never deployed in the wild and the answer is HTTP/2.
|
||
inFlightResponse = w
|
||
serverHandler{c.server}.ServeHTTP(w, w.req)
|
||
inFlightResponse = nil
|
||
w.cancelCtx()
|
||
if c.hijacked() {
|
||
return
|
||
}
|
||
w.finishRequest()
|
||
c.rwc.SetWriteDeadline(time.Time{})
|
||
if !w.shouldReuseConnection() {
|
||
if w.requestBodyLimitHit || w.closedRequestBodyEarly() {
|
||
c.closeWriteAndWait()
|
||
}
|
||
return
|
||
}
|
||
c.setState(c.rwc, StateIdle, runHooks)
|
||
c.curReq.Store(nil)
|
||
|
||
if !w.conn.server.doKeepAlives() {
|
||
// We're in shutdown mode. We might've replied
|
||
// to the user without "Connection: close" and
|
||
// they might think they can send another
|
||
// request, but such is life with HTTP/1.1.
|
||
return
|
||
}
|
||
|
||
if d := c.server.idleTimeout(); d > 0 {
|
||
c.rwc.SetReadDeadline(time.Now().Add(d))
|
||
} else {
|
||
c.rwc.SetReadDeadline(time.Time{})
|
||
}
|
||
|
||
// Wait for the connection to become readable again before trying to
|
||
// read the next request. This prevents a ReadHeaderTimeout or
|
||
// ReadTimeout from starting until the first bytes of the next request
|
||
// have been received.
|
||
if _, err := c.bufr.Peek(4); err != nil {
|
||
return
|
||
}
|
||
|
||
c.rwc.SetReadDeadline(time.Time{})
|
||
}
|
||
}
|
||
|
||
func (w *response) sendExpectationFailed() {
|
||
// TODO(bradfitz): let ServeHTTP handlers handle
|
||
// requests with non-standard expectation[s]? Seems
|
||
// theoretical at best, and doesn't fit into the
|
||
// current ServeHTTP model anyway. We'd need to
|
||
// make the ResponseWriter an optional
|
||
// "ExpectReplier" interface or something.
|
||
//
|
||
// For now we'll just obey RFC 7231 5.1.1 which says
|
||
// "A server that receives an Expect field-value other
|
||
// than 100-continue MAY respond with a 417 (Expectation
|
||
// Failed) status code to indicate that the unexpected
|
||
// expectation cannot be met."
|
||
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.handlerDone.Load() {
|
||
panic("net/http: Hijack called after ServeHTTP finished")
|
||
}
|
||
w.disableWriteContinue()
|
||
if w.wroteHeader {
|
||
w.cw.flush()
|
||
}
|
||
|
||
c := w.conn
|
||
c.mu.Lock()
|
||
defer c.mu.Unlock()
|
||
|
||
// Release the bufioWriter that writes to the chunk writer, it is not
|
||
// used after a connection has been hijacked.
|
||
rwc, buf, err = c.hijackLocked()
|
||
if err == nil {
|
||
putBufioWriter(w.w)
|
||
w.w = nil
|
||
}
|
||
return rwc, buf, err
|
||
}
|
||
|
||
func (w *response) CloseNotify() <-chan bool {
|
||
if w.handlerDone.Load() {
|
||
panic("net/http: CloseNotify called after ServeHTTP finished")
|
||
}
|
||
return w.closeNotifyCh
|
||
}
|
||
|
||
func registerOnHitEOF(rc io.ReadCloser, fn func()) {
|
||
switch v := rc.(type) {
|
||
case *expectContinueReader:
|
||
registerOnHitEOF(v.readCloser, fn)
|
||
case *body:
|
||
v.registerOnHitEOF(fn)
|
||
default:
|
||
panic("unexpected type " + fmt.Sprintf("%T", rc))
|
||
}
|
||
}
|
||
|
||
// requestBodyRemains reports whether future calls to Read
|
||
// on rc might yield more data.
|
||
func requestBodyRemains(rc io.ReadCloser) bool {
|
||
if rc == NoBody {
|
||
return false
|
||
}
|
||
switch v := rc.(type) {
|
||
case *expectContinueReader:
|
||
return requestBodyRemains(v.readCloser)
|
||
case *body:
|
||
return v.bodyRemains()
|
||
default:
|
||
panic("unexpected type " + fmt.Sprintf("%T", rc))
|
||
}
|
||
}
|
||
|
||
// 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] that calls f.
|
||
type HandlerFunc func(ResponseWriter, *Request)
|
||
|
||
// ServeHTTP calls f(w, r).
|
||
func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
|
||
f(w, r)
|
||
}
|
||
|
||
// Helper handlers
|
||
|
||
// Error replies to the request with the specified error message and HTTP code.
|
||
// It does not otherwise end the request; the caller should ensure no further
|
||
// writes are done to w.
|
||
// The error message should be plain text.
|
||
//
|
||
// Error deletes the Content-Length and Content-Encoding headers,
|
||
// sets Content-Type to “text/plain; charset=utf-8”,
|
||
// and sets X-Content-Type-Options to “nosniff”.
|
||
// This configures the header properly for the error message,
|
||
// in case the caller had set it up expecting a successful output.
|
||
func Error(w ResponseWriter, error string, code int) {
|
||
h := w.Header()
|
||
// We delete headers which might be valid for some other content,
|
||
// but not anymore for the error content.
|
||
h.Del("Content-Length")
|
||
h.Del("Content-Encoding")
|
||
|
||
// There might be content type already set, but we reset it to
|
||
// text/plain for the error message.
|
||
h.Set("Content-Type", "text/plain; charset=utf-8")
|
||
h.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 RawPath if set) 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. The prefix must
|
||
// match exactly: if the prefix in the request contains escaped characters
|
||
// the reply is also an HTTP 404 not found error.
|
||
func StripPrefix(prefix string, h Handler) Handler {
|
||
if prefix == "" {
|
||
return h
|
||
}
|
||
return HandlerFunc(func(w ResponseWriter, r *Request) {
|
||
p := strings.TrimPrefix(r.URL.Path, prefix)
|
||
rp := strings.TrimPrefix(r.URL.RawPath, prefix)
|
||
if len(p) < len(r.URL.Path) && (r.URL.RawPath == "" || len(rp) < len(r.URL.RawPath)) {
|
||
r2 := new(Request)
|
||
*r2 = *r
|
||
r2.URL = new(url.URL)
|
||
*r2.URL = *r.URL
|
||
r2.URL.Path = p
|
||
r2.URL.RawPath = rp
|
||
h.ServeHTTP(w, r2)
|
||
} else {
|
||
NotFound(w, r)
|
||
}
|
||
})
|
||
}
|
||
|
||
// Redirect replies to the request with a redirect to url,
|
||
// which may be a path relative to the request path.
|
||
//
|
||
// The provided code should be in the 3xx range and is usually
|
||
// [StatusMovedPermanently], [StatusFound] or [StatusSeeOther].
|
||
//
|
||
// If the Content-Type header has not been set, [Redirect] sets it
|
||
// to "text/html; charset=utf-8" and writes a small HTML body.
|
||
// Setting the Content-Type header to any value, including nil,
|
||
// disables that behavior.
|
||
func Redirect(w ResponseWriter, r *Request, url string, code int) {
|
||
if u, err := urlpkg.Parse(url); err == nil {
|
||
// If url was relative, make its path absolute by
|
||
// combining with request path.
|
||
// The client would probably do this for us,
|
||
// but doing it ourselves is more reliable.
|
||
// See RFC 7231, section 7.1.2
|
||
if u.Scheme == "" && u.Host == "" {
|
||
oldpath := r.URL.Path
|
||
if oldpath == "" { // should not happen, but avoid a crash if it does
|
||
oldpath = "/"
|
||
}
|
||
|
||
// no leading http://server
|
||
if url == "" || url[0] != '/' {
|
||
// make relative path absolute
|
||
olddir, _ := path.Split(oldpath)
|
||
url = olddir + url
|
||
}
|
||
|
||
var query string
|
||
if i := strings.Index(url, "?"); i != -1 {
|
||
url, query = url[:i], url[i:]
|
||
}
|
||
|
||
// clean up but preserve trailing slash
|
||
trailing := strings.HasSuffix(url, "/")
|
||
url = path.Clean(url)
|
||
if trailing && !strings.HasSuffix(url, "/") {
|
||
url += "/"
|
||
}
|
||
url += query
|
||
}
|
||
}
|
||
|
||
h := w.Header()
|
||
|
||
// RFC 7231 notes that a short HTML body is usually included in
|
||
// the response because older user agents may not understand 301/307.
|
||
// Do it only if the request didn't already have a Content-Type header.
|
||
_, hadCT := h["Content-Type"]
|
||
|
||
h.Set("Location", hexEscapeNonASCII(url))
|
||
if !hadCT && (r.Method == "GET" || r.Method == "HEAD") {
|
||
h.Set("Content-Type", "text/html; charset=utf-8")
|
||
}
|
||
w.WriteHeader(code)
|
||
|
||
// Shouldn't send the body for POST or HEAD; that leaves GET.
|
||
if !hadCT && r.Method == "GET" {
|
||
body := "<a href=\"" + htmlEscape(url) + "\">" + StatusText(code) + "</a>.\n"
|
||
fmt.Fprintln(w, body)
|
||
}
|
||
}
|
||
|
||
var htmlReplacer = strings.NewReplacer(
|
||
"&", "&",
|
||
"<", "<",
|
||
">", ">",
|
||
// """ is shorter than """.
|
||
`"`, """,
|
||
// "'" is shorter than "'" and apos was not in HTML until HTML5.
|
||
"'", "'",
|
||
)
|
||
|
||
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.
|
||
//
|
||
// The provided code should be in the 3xx range and is usually
|
||
// [StatusMovedPermanently], [StatusFound] or [StatusSeeOther].
|
||
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
|
||
//
|
||
// Patterns can match the method, host and path of a request.
|
||
// Some examples:
|
||
//
|
||
// - "/index.html" matches the path "/index.html" for any host and method.
|
||
// - "GET /static/" matches a GET request whose path begins with "/static/".
|
||
// - "example.com/" matches any request to the host "example.com".
|
||
// - "example.com/{$}" matches requests with host "example.com" and path "/".
|
||
// - "/b/{bucket}/o/{objectname...}" matches paths whose first segment is "b"
|
||
// and whose third segment is "o". The name "bucket" denotes the second
|
||
// segment and "objectname" denotes the remainder of the path.
|
||
//
|
||
// In general, a pattern looks like
|
||
//
|
||
// [METHOD ][HOST]/[PATH]
|
||
//
|
||
// All three parts are optional; "/" is a valid pattern.
|
||
// If METHOD is present, it must be followed by at least one space or tab.
|
||
//
|
||
// Literal (that is, non-wildcard) parts of a pattern match
|
||
// the corresponding parts of a request case-sensitively.
|
||
//
|
||
// A pattern with no method matches every method. A pattern
|
||
// with the method GET matches both GET and HEAD requests.
|
||
// Otherwise, the method must match exactly.
|
||
//
|
||
// A pattern with no host matches every host.
|
||
// A pattern with a host matches URLs on that host only.
|
||
//
|
||
// A path can include wildcard segments of the form {NAME} or {NAME...}.
|
||
// For example, "/b/{bucket}/o/{objectname...}".
|
||
// The wildcard name must be a valid Go identifier.
|
||
// Wildcards must be full path segments: they must be preceded by a slash and followed by
|
||
// either a slash or the end of the string.
|
||
// For example, "/b_{bucket}" is not a valid pattern.
|
||
//
|
||
// Normally a wildcard matches only a single path segment,
|
||
// ending at the next literal slash (not %2F) in the request URL.
|
||
// But if the "..." is present, then the wildcard matches the remainder of the URL path, including slashes.
|
||
// (Therefore it is invalid for a "..." wildcard to appear anywhere but at the end of a pattern.)
|
||
// The match for a wildcard can be obtained by calling [Request.PathValue] with the wildcard's name.
|
||
// A trailing slash in a path acts as an anonymous "..." wildcard.
|
||
//
|
||
// The special wildcard {$} matches only the end of the URL.
|
||
// For example, the pattern "/{$}" matches only the path "/",
|
||
// whereas the pattern "/" matches every path.
|
||
//
|
||
// For matching, both pattern paths and incoming request paths are unescaped segment by segment.
|
||
// So, for example, the path "/a%2Fb/100%25" is treated as having two segments, "a/b" and "100%".
|
||
// The pattern "/a%2fb/" matches it, but the pattern "/a/b/" does not.
|
||
//
|
||
// # Precedence
|
||
//
|
||
// If two or more patterns match a request, then the most specific pattern takes precedence.
|
||
// A pattern P1 is more specific than P2 if P1 matches a strict subset of P2’s requests;
|
||
// that is, if P2 matches all the requests of P1 and more.
|
||
// If neither is more specific, then the patterns conflict.
|
||
// There is one exception to this rule, for backwards compatibility:
|
||
// if two patterns would otherwise conflict and one has a host while the other does not,
|
||
// then the pattern with the host takes precedence.
|
||
// If a pattern passed to [ServeMux.Handle] or [ServeMux.HandleFunc] conflicts with
|
||
// another pattern that is already registered, those functions panic.
|
||
//
|
||
// As an example of the general rule, "/images/thumbnails/" is more specific than "/images/",
|
||
// so both can be registered.
|
||
// The former matches paths beginning with "/images/thumbnails/"
|
||
// and the latter will match any other path in the "/images/" subtree.
|
||
//
|
||
// As another example, consider the patterns "GET /" and "/index.html":
|
||
// both match a GET request for "/index.html", but the former pattern
|
||
// matches all other GET and HEAD requests, while the latter matches any
|
||
// request for "/index.html" that uses a different method.
|
||
// The patterns conflict.
|
||
//
|
||
// # Trailing-slash redirection
|
||
//
|
||
// Consider a [ServeMux] with a handler for a subtree, registered using a trailing slash or "..." wildcard.
|
||
// If the ServeMux receives a request for the subtree root without a trailing slash,
|
||
// it redirects the request by adding the trailing slash.
|
||
// This behavior can be overridden with a separate registration for the path without
|
||
// the trailing slash or "..." wildcard. For example, registering "/images/" causes ServeMux
|
||
// to redirect a request for "/images" to "/images/", unless "/images" has
|
||
// been registered separately.
|
||
//
|
||
// # Request sanitizing
|
||
//
|
||
// ServeMux also takes care of sanitizing the URL request path and the Host
|
||
// header, stripping the port number and redirecting any request containing . or
|
||
// .. segments or repeated slashes to an equivalent, cleaner URL.
|
||
//
|
||
// # Compatibility
|
||
//
|
||
// The pattern syntax and matching behavior of ServeMux changed significantly
|
||
// in Go 1.22. To restore the old behavior, set the GODEBUG environment variable
|
||
// to "httpmuxgo121=1". This setting is read once, at program startup; changes
|
||
// during execution will be ignored.
|
||
//
|
||
// The backwards-incompatible changes include:
|
||
// - Wildcards are just ordinary literal path segments in 1.21.
|
||
// For example, the pattern "/{x}" will match only that path in 1.21,
|
||
// but will match any one-segment path in 1.22.
|
||
// - In 1.21, no pattern was rejected, unless it was empty or conflicted with an existing pattern.
|
||
// In 1.22, syntactically invalid patterns will cause [ServeMux.Handle] and [ServeMux.HandleFunc] to panic.
|
||
// For example, in 1.21, the patterns "/{" and "/a{x}" match themselves,
|
||
// but in 1.22 they are invalid and will cause a panic when registered.
|
||
// - In 1.22, each segment of a pattern is unescaped; this was not done in 1.21.
|
||
// For example, in 1.22 the pattern "/%61" matches the path "/a" ("%61" being the URL escape sequence for "a"),
|
||
// but in 1.21 it would match only the path "/%2561" (where "%25" is the escape for the percent sign).
|
||
// - When matching patterns to paths, in 1.22 each segment of the path is unescaped; in 1.21, the entire path is unescaped.
|
||
// This change mostly affects how paths with %2F escapes adjacent to slashes are treated.
|
||
// See https://go.dev/issue/21955 for details.
|
||
type ServeMux struct {
|
||
mu sync.RWMutex
|
||
tree routingNode
|
||
index routingIndex
|
||
patterns []*pattern // TODO(jba): remove if possible
|
||
mux121 serveMux121 // used only when GODEBUG=httpmuxgo121=1
|
||
}
|
||
|
||
// NewServeMux allocates and returns a new [ServeMux].
|
||
func NewServeMux() *ServeMux {
|
||
return &ServeMux{}
|
||
}
|
||
|
||
// DefaultServeMux is the default [ServeMux] used by [Serve].
|
||
var DefaultServeMux = &defaultServeMux
|
||
|
||
var defaultServeMux ServeMux
|
||
|
||
// cleanPath returns 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)
|
||
// path.Clean removes trailing slash except for root;
|
||
// put the trailing slash back if necessary.
|
||
if p[len(p)-1] == '/' && np != "/" {
|
||
// Fast path for common case of p being the string we want:
|
||
if len(p) == len(np)+1 && strings.HasPrefix(p, np) {
|
||
np = p
|
||
} else {
|
||
np += "/"
|
||
}
|
||
}
|
||
return np
|
||
}
|
||
|
||
// stripHostPort returns h without any trailing ":<port>".
|
||
func stripHostPort(h string) string {
|
||
// If no port on host, return unchanged
|
||
if !strings.Contains(h, ":") {
|
||
return h
|
||
}
|
||
host, _, err := net.SplitHostPort(h)
|
||
if err != nil {
|
||
return h // on error, return unchanged
|
||
}
|
||
return host
|
||
}
|
||
|
||
// 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. If the host contains a port, it is ignored
|
||
// when matching handlers.
|
||
//
|
||
// The path and host are used unchanged for CONNECT requests.
|
||
//
|
||
// Handler also returns the registered pattern that matches the
|
||
// request or, in the case of internally-generated redirects,
|
||
// the path 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 use121 {
|
||
return mux.mux121.findHandler(r)
|
||
}
|
||
h, p, _, _ := mux.findHandler(r)
|
||
return h, p
|
||
}
|
||
|
||
// findHandler finds a handler for a request.
|
||
// If there is a matching handler, it returns it and the pattern that matched.
|
||
// Otherwise it returns a Redirect or NotFound handler with the path that would match
|
||
// after the redirect.
|
||
func (mux *ServeMux) findHandler(r *Request) (h Handler, patStr string, _ *pattern, matches []string) {
|
||
var n *routingNode
|
||
host := r.URL.Host
|
||
escapedPath := r.URL.EscapedPath()
|
||
path := escapedPath
|
||
// CONNECT requests are not canonicalized.
|
||
if r.Method == "CONNECT" {
|
||
// If r.URL.Path is /tree and its handler is not registered,
|
||
// the /tree -> /tree/ redirect applies to CONNECT requests
|
||
// but the path canonicalization does not.
|
||
_, _, u := mux.matchOrRedirect(host, r.Method, path, r.URL)
|
||
if u != nil {
|
||
return RedirectHandler(u.String(), StatusMovedPermanently), u.Path, nil, nil
|
||
}
|
||
// Redo the match, this time with r.Host instead of r.URL.Host.
|
||
// Pass a nil URL to skip the trailing-slash redirect logic.
|
||
n, matches, _ = mux.matchOrRedirect(r.Host, r.Method, path, nil)
|
||
} else {
|
||
// All other requests have any port stripped and path cleaned
|
||
// before passing to mux.handler.
|
||
host = stripHostPort(r.Host)
|
||
path = cleanPath(path)
|
||
|
||
// If the given path is /tree and its handler is not registered,
|
||
// redirect for /tree/.
|
||
var u *url.URL
|
||
n, matches, u = mux.matchOrRedirect(host, r.Method, path, r.URL)
|
||
if u != nil {
|
||
return RedirectHandler(u.String(), StatusMovedPermanently), u.Path, nil, nil
|
||
}
|
||
if path != escapedPath {
|
||
// Redirect to cleaned path.
|
||
patStr := ""
|
||
if n != nil {
|
||
patStr = n.pattern.String()
|
||
}
|
||
u := &url.URL{Path: path, RawQuery: r.URL.RawQuery}
|
||
return RedirectHandler(u.String(), StatusMovedPermanently), patStr, nil, nil
|
||
}
|
||
}
|
||
if n == nil {
|
||
// We didn't find a match with the request method. To distinguish between
|
||
// Not Found and Method Not Allowed, see if there is another pattern that
|
||
// matches except for the method.
|
||
allowedMethods := mux.matchingMethods(host, path)
|
||
if len(allowedMethods) > 0 {
|
||
return HandlerFunc(func(w ResponseWriter, r *Request) {
|
||
w.Header().Set("Allow", strings.Join(allowedMethods, ", "))
|
||
Error(w, StatusText(StatusMethodNotAllowed), StatusMethodNotAllowed)
|
||
}), "", nil, nil
|
||
}
|
||
return NotFoundHandler(), "", nil, nil
|
||
}
|
||
return n.handler, n.pattern.String(), n.pattern, matches
|
||
}
|
||
|
||
// matchOrRedirect looks up a node in the tree that matches the host, method and path.
|
||
//
|
||
// If the url argument is non-nil, handler also deals with trailing-slash
|
||
// redirection: when a path doesn't match exactly, the match is tried again
|
||
// after appending "/" to the path. If that second match succeeds, the last
|
||
// return value is the URL to redirect to.
|
||
func (mux *ServeMux) matchOrRedirect(host, method, path string, u *url.URL) (_ *routingNode, matches []string, redirectTo *url.URL) {
|
||
mux.mu.RLock()
|
||
defer mux.mu.RUnlock()
|
||
|
||
n, matches := mux.tree.match(host, method, path)
|
||
// If we have an exact match, or we were asked not to try trailing-slash redirection,
|
||
// or the URL already has a trailing slash, then we're done.
|
||
if !exactMatch(n, path) && u != nil && !strings.HasSuffix(path, "/") {
|
||
// If there is an exact match with a trailing slash, then redirect.
|
||
path += "/"
|
||
n2, _ := mux.tree.match(host, method, path)
|
||
if exactMatch(n2, path) {
|
||
return nil, nil, &url.URL{Path: cleanPath(u.Path) + "/", RawQuery: u.RawQuery}
|
||
}
|
||
}
|
||
return n, matches, nil
|
||
}
|
||
|
||
// exactMatch reports whether the node's pattern exactly matches the path.
|
||
// As a special case, if the node is nil, exactMatch return false.
|
||
//
|
||
// Before wildcards were introduced, it was clear that an exact match meant
|
||
// that the pattern and path were the same string. The only other possibility
|
||
// was that a trailing-slash pattern, like "/", matched a path longer than
|
||
// it, like "/a".
|
||
//
|
||
// With wildcards, we define an inexact match as any one where a multi wildcard
|
||
// matches a non-empty string. All other matches are exact.
|
||
// For example, these are all exact matches:
|
||
//
|
||
// pattern path
|
||
// /a /a
|
||
// /{x} /a
|
||
// /a/{$} /a/
|
||
// /a/ /a/
|
||
//
|
||
// The last case has a multi wildcard (implicitly), but the match is exact because
|
||
// the wildcard matches the empty string.
|
||
//
|
||
// Examples of matches that are not exact:
|
||
//
|
||
// pattern path
|
||
// / /a
|
||
// /a/{x...} /a/b
|
||
func exactMatch(n *routingNode, path string) bool {
|
||
if n == nil {
|
||
return false
|
||
}
|
||
// We can't directly implement the definition (empty match for multi
|
||
// wildcard) because we don't record a match for anonymous multis.
|
||
|
||
// If there is no multi, the match is exact.
|
||
if !n.pattern.lastSegment().multi {
|
||
return true
|
||
}
|
||
|
||
// If the path doesn't end in a trailing slash, then the multi match
|
||
// is non-empty.
|
||
if len(path) > 0 && path[len(path)-1] != '/' {
|
||
return false
|
||
}
|
||
// Only patterns ending in {$} or a multi wildcard can
|
||
// match a path with a trailing slash.
|
||
// For the match to be exact, the number of pattern
|
||
// segments should be the same as the number of slashes in the path.
|
||
// E.g. "/a/b/{$}" and "/a/b/{...}" exactly match "/a/b/", but "/a/" does not.
|
||
return len(n.pattern.segments) == strings.Count(path, "/")
|
||
}
|
||
|
||
// matchingMethods return a sorted list of all methods that would match with the given host and path.
|
||
func (mux *ServeMux) matchingMethods(host, path string) []string {
|
||
// Hold the read lock for the entire method so that the two matches are done
|
||
// on the same set of registered patterns.
|
||
mux.mu.RLock()
|
||
defer mux.mu.RUnlock()
|
||
ms := map[string]bool{}
|
||
mux.tree.matchingMethods(host, path, ms)
|
||
// matchOrRedirect will try appending a trailing slash if there is no match.
|
||
mux.tree.matchingMethods(host, path+"/", ms)
|
||
methods := mapKeys(ms)
|
||
slices.Sort(methods)
|
||
return methods
|
||
}
|
||
|
||
// TODO(jba): replace with maps.Keys when it is defined.
|
||
func mapKeys[K comparable, V any](m map[K]V) []K {
|
||
var ks []K
|
||
for k := range m {
|
||
ks = append(ks, k)
|
||
}
|
||
return ks
|
||
}
|
||
|
||
// 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
|
||
}
|
||
var h Handler
|
||
if use121 {
|
||
h, _ = mux.mux121.findHandler(r)
|
||
} else {
|
||
h, r.Pattern, r.pat, r.matches = mux.findHandler(r)
|
||
}
|
||
h.ServeHTTP(w, r)
|
||
}
|
||
|
||
// The four functions below all call ServeMux.register so that callerLocation
|
||
// always refers to user code.
|
||
|
||
// Handle registers the handler for the given pattern.
|
||
// If the given pattern conflicts, with one that is already registered, Handle
|
||
// panics.
|
||
func (mux *ServeMux) Handle(pattern string, handler Handler) {
|
||
if use121 {
|
||
mux.mux121.handle(pattern, handler)
|
||
} else {
|
||
mux.register(pattern, handler)
|
||
}
|
||
}
|
||
|
||
// HandleFunc registers the handler function for the given pattern.
|
||
// If the given pattern conflicts, with one that is already registered, HandleFunc
|
||
// panics.
|
||
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
|
||
if use121 {
|
||
mux.mux121.handleFunc(pattern, handler)
|
||
} else {
|
||
mux.register(pattern, HandlerFunc(handler))
|
||
}
|
||
}
|
||
|
||
// Handle registers the handler for the given pattern in [DefaultServeMux].
|
||
// The documentation for [ServeMux] explains how patterns are matched.
|
||
func Handle(pattern string, handler Handler) {
|
||
if use121 {
|
||
DefaultServeMux.mux121.handle(pattern, handler)
|
||
} else {
|
||
DefaultServeMux.register(pattern, handler)
|
||
}
|
||
}
|
||
|
||
// HandleFunc registers the handler function for the given pattern in [DefaultServeMux].
|
||
// The documentation for [ServeMux] explains how patterns are matched.
|
||
func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
|
||
if use121 {
|
||
DefaultServeMux.mux121.handleFunc(pattern, handler)
|
||
} else {
|
||
DefaultServeMux.register(pattern, HandlerFunc(handler))
|
||
}
|
||
}
|
||
|
||
func (mux *ServeMux) register(pattern string, handler Handler) {
|
||
if err := mux.registerErr(pattern, handler); err != nil {
|
||
panic(err)
|
||
}
|
||
}
|
||
|
||
func (mux *ServeMux) registerErr(patstr string, handler Handler) error {
|
||
if patstr == "" {
|
||
return errors.New("http: invalid pattern")
|
||
}
|
||
if handler == nil {
|
||
return errors.New("http: nil handler")
|
||
}
|
||
if f, ok := handler.(HandlerFunc); ok && f == nil {
|
||
return errors.New("http: nil handler")
|
||
}
|
||
|
||
pat, err := parsePattern(patstr)
|
||
if err != nil {
|
||
return fmt.Errorf("parsing %q: %w", patstr, err)
|
||
}
|
||
|
||
// Get the caller's location, for better conflict error messages.
|
||
// Skip register and whatever calls it.
|
||
_, file, line, ok := runtime.Caller(3)
|
||
if !ok {
|
||
pat.loc = "unknown location"
|
||
} else {
|
||
pat.loc = fmt.Sprintf("%s:%d", file, line)
|
||
}
|
||
|
||
mux.mu.Lock()
|
||
defer mux.mu.Unlock()
|
||
// Check for conflict.
|
||
if err := mux.index.possiblyConflictingPatterns(pat, func(pat2 *pattern) error {
|
||
if pat.conflictsWith(pat2) {
|
||
d := describeConflict(pat, pat2)
|
||
return fmt.Errorf("pattern %q (registered at %s) conflicts with pattern %q (registered at %s):\n%s",
|
||
pat, pat.loc, pat2, pat2.loc, d)
|
||
}
|
||
return nil
|
||
}); err != nil {
|
||
return err
|
||
}
|
||
mux.tree.addPattern(pat, handler)
|
||
mux.index.addPattern(pat)
|
||
mux.patterns = append(mux.patterns, pat)
|
||
return nil
|
||
}
|
||
|
||
// 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.
|
||
//
|
||
// The handler is typically nil, in which case [DefaultServeMux] is used.
|
||
//
|
||
// HTTP/2 support is only enabled if the Listener returns [*tls.Conn]
|
||
// connections and they were configured with "h2" in the TLS
|
||
// Config.NextProtos.
|
||
//
|
||
// Serve always returns a non-nil error.
|
||
func Serve(l net.Listener, handler Handler) error {
|
||
srv := &Server{Handler: handler}
|
||
return srv.Serve(l)
|
||
}
|
||
|
||
// ServeTLS accepts incoming HTTPS 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.
|
||
//
|
||
// The handler is typically nil, in which case [DefaultServeMux] is used.
|
||
//
|
||
// 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.
|
||
//
|
||
// ServeTLS always returns a non-nil error.
|
||
func ServeTLS(l net.Listener, handler Handler, certFile, keyFile string) error {
|
||
srv := &Server{Handler: handler}
|
||
return srv.ServeTLS(l, certFile, keyFile)
|
||
}
|
||
|
||
// A Server defines parameters for running an HTTP server.
|
||
// The zero value for Server is a valid configuration.
|
||
type Server struct {
|
||
// Addr optionally specifies the TCP address for the server to listen on,
|
||
// in the form "host:port". If empty, ":http" (port 80) is used.
|
||
// The service names are defined in RFC 6335 and assigned by IANA.
|
||
// See net.Dial for details of the address format.
|
||
Addr string
|
||
|
||
Handler Handler // handler to invoke, http.DefaultServeMux if nil
|
||
|
||
// DisableGeneralOptionsHandler, if true, passes "OPTIONS *" requests to the Handler,
|
||
// otherwise responds with 200 OK and Content-Length: 0.
|
||
DisableGeneralOptionsHandler bool
|
||
|
||
// TLSConfig optionally provides a TLS configuration for use
|
||
// by ServeTLS and ListenAndServeTLS. Note that this value is
|
||
// cloned by ServeTLS and ListenAndServeTLS, so it's not
|
||
// possible to modify the configuration with methods like
|
||
// tls.Config.SetSessionTicketKeys. To use
|
||
// SetSessionTicketKeys, use Server.Serve with a TLS Listener
|
||
// instead.
|
||
TLSConfig *tls.Config
|
||
|
||
// ReadTimeout is the maximum duration for reading the entire
|
||
// request, including the body. A zero or negative value means
|
||
// there will be no timeout.
|
||
//
|
||
// Because ReadTimeout does not let Handlers make per-request
|
||
// decisions on each request body's acceptable deadline or
|
||
// upload rate, most users will prefer to use
|
||
// ReadHeaderTimeout. It is valid to use them both.
|
||
ReadTimeout time.Duration
|
||
|
||
// ReadHeaderTimeout is the amount of time allowed to read
|
||
// request headers. The connection's read deadline is reset
|
||
// after reading the headers and the Handler can decide what
|
||
// is considered too slow for the body. If zero, the value of
|
||
// ReadTimeout is used. If negative, or if zero and ReadTimeout
|
||
// is zero or negative, there is no timeout.
|
||
ReadHeaderTimeout time.Duration
|
||
|
||
// WriteTimeout is the maximum duration before timing out
|
||
// writes of the response. It is reset whenever a new
|
||
// request's header is read. Like ReadTimeout, it does not
|
||
// let Handlers make decisions on a per-request basis.
|
||
// A zero or negative value means there will be no timeout.
|
||
WriteTimeout time.Duration
|
||
|
||
// IdleTimeout is the maximum amount of time to wait for the
|
||
// next request when keep-alives are enabled. If zero, the value
|
||
// of ReadTimeout is used. If negative, or if zero and ReadTimeout
|
||
// is zero or negative, there is no timeout.
|
||
IdleTimeout time.Duration
|
||
|
||
// MaxHeaderBytes controls the maximum number of bytes the
|
||
// server will read parsing the request header's keys and
|
||
// values, including the request line. It does not limit the
|
||
// size of the request body.
|
||
// If zero, DefaultMaxHeaderBytes is used.
|
||
MaxHeaderBytes int
|
||
|
||
// TLSNextProto optionally specifies a function to take over
|
||
// ownership of the provided TLS connection when an ALPN
|
||
// 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.
|
||
// If TLSNextProto is not nil, HTTP/2 support is not enabled
|
||
// automatically.
|
||
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, unexpected behavior from handlers, and
|
||
// underlying FileSystem errors.
|
||
// If nil, logging is done via the log package's standard logger.
|
||
ErrorLog *log.Logger
|
||
|
||
// BaseContext optionally specifies a function that returns
|
||
// the base context for incoming requests on this server.
|
||
// The provided Listener is the specific Listener that's
|
||
// about to start accepting requests.
|
||
// If BaseContext is nil, the default is context.Background().
|
||
// If non-nil, it must return a non-nil context.
|
||
BaseContext func(net.Listener) context.Context
|
||
|
||
// ConnContext optionally specifies a function that modifies
|
||
// the context used for a new connection c. The provided ctx
|
||
// is derived from the base context and has a ServerContextKey
|
||
// value.
|
||
ConnContext func(ctx context.Context, c net.Conn) context.Context
|
||
|
||
inShutdown atomic.Bool // true when server is in shutdown
|
||
|
||
disableKeepAlives atomic.Bool
|
||
nextProtoOnce sync.Once // guards setupHTTP2_* init
|
||
nextProtoErr error // result of http2.ConfigureServer if used
|
||
|
||
mu sync.Mutex
|
||
listeners map[*net.Listener]struct{}
|
||
activeConn map[*conn]struct{}
|
||
onShutdown []func()
|
||
|
||
listenerGroup sync.WaitGroup
|
||
}
|
||
|
||
// Close immediately closes all active net.Listeners and any
|
||
// connections in state [StateNew], [StateActive], or [StateIdle]. For a
|
||
// graceful shutdown, use [Server.Shutdown].
|
||
//
|
||
// Close does not attempt to close (and does not even know about)
|
||
// any hijacked connections, such as WebSockets.
|
||
//
|
||
// Close returns any error returned from closing the [Server]'s
|
||
// underlying Listener(s).
|
||
func (srv *Server) Close() error {
|
||
srv.inShutdown.Store(true)
|
||
srv.mu.Lock()
|
||
defer srv.mu.Unlock()
|
||
err := srv.closeListenersLocked()
|
||
|
||
// Unlock srv.mu while waiting for listenerGroup.
|
||
// The group Add and Done calls are made with srv.mu held,
|
||
// to avoid adding a new listener in the window between
|
||
// us setting inShutdown above and waiting here.
|
||
srv.mu.Unlock()
|
||
srv.listenerGroup.Wait()
|
||
srv.mu.Lock()
|
||
|
||
for c := range srv.activeConn {
|
||
c.rwc.Close()
|
||
delete(srv.activeConn, c)
|
||
}
|
||
return err
|
||
}
|
||
|
||
// shutdownPollIntervalMax is the max polling interval when checking
|
||
// quiescence during Server.Shutdown. Polling starts with a small
|
||
// interval and backs off to the max.
|
||
// Ideally we could find a solution that doesn't involve polling,
|
||
// but which also doesn't have a high runtime cost (and doesn't
|
||
// involve any contentious mutexes), but that is left as an
|
||
// exercise for the reader.
|
||
const shutdownPollIntervalMax = 500 * time.Millisecond
|
||
|
||
// Shutdown gracefully shuts down the server without interrupting any
|
||
// active connections. Shutdown works by first closing all open
|
||
// listeners, then closing all idle connections, and then waiting
|
||
// indefinitely for connections to return to idle and then shut down.
|
||
// If the provided context expires before the shutdown is complete,
|
||
// Shutdown returns the context's error, otherwise it returns any
|
||
// error returned from closing the [Server]'s underlying Listener(s).
|
||
//
|
||
// When Shutdown is called, [Serve], [ListenAndServe], and
|
||
// [ListenAndServeTLS] immediately return [ErrServerClosed]. Make sure the
|
||
// program doesn't exit and waits instead for Shutdown to return.
|
||
//
|
||
// Shutdown does not attempt to close nor wait for hijacked
|
||
// connections such as WebSockets. The caller of Shutdown should
|
||
// separately notify such long-lived connections of shutdown and wait
|
||
// for them to close, if desired. See [Server.RegisterOnShutdown] for a way to
|
||
// register shutdown notification functions.
|
||
//
|
||
// Once Shutdown has been called on a server, it may not be reused;
|
||
// future calls to methods such as Serve will return ErrServerClosed.
|
||
func (srv *Server) Shutdown(ctx context.Context) error {
|
||
srv.inShutdown.Store(true)
|
||
|
||
srv.mu.Lock()
|
||
lnerr := srv.closeListenersLocked()
|
||
for _, f := range srv.onShutdown {
|
||
go f()
|
||
}
|
||
srv.mu.Unlock()
|
||
srv.listenerGroup.Wait()
|
||
|
||
pollIntervalBase := time.Millisecond
|
||
nextPollInterval := func() time.Duration {
|
||
// Add 10% jitter.
|
||
interval := pollIntervalBase + time.Duration(rand.Intn(int(pollIntervalBase/10)))
|
||
// Double and clamp for next time.
|
||
pollIntervalBase *= 2
|
||
if pollIntervalBase > shutdownPollIntervalMax {
|
||
pollIntervalBase = shutdownPollIntervalMax
|
||
}
|
||
return interval
|
||
}
|
||
|
||
timer := time.NewTimer(nextPollInterval())
|
||
defer timer.Stop()
|
||
for {
|
||
if srv.closeIdleConns() {
|
||
return lnerr
|
||
}
|
||
select {
|
||
case <-ctx.Done():
|
||
return ctx.Err()
|
||
case <-timer.C:
|
||
timer.Reset(nextPollInterval())
|
||
}
|
||
}
|
||
}
|
||
|
||
// RegisterOnShutdown registers a function to call on [Server.Shutdown].
|
||
// This can be used to gracefully shutdown connections that have
|
||
// undergone ALPN protocol upgrade or that have been hijacked.
|
||
// This function should start protocol-specific graceful shutdown,
|
||
// but should not wait for shutdown to complete.
|
||
func (srv *Server) RegisterOnShutdown(f func()) {
|
||
srv.mu.Lock()
|
||
srv.onShutdown = append(srv.onShutdown, f)
|
||
srv.mu.Unlock()
|
||
}
|
||
|
||
// closeIdleConns closes all idle connections and reports whether the
|
||
// server is quiescent.
|
||
func (s *Server) closeIdleConns() bool {
|
||
s.mu.Lock()
|
||
defer s.mu.Unlock()
|
||
quiescent := true
|
||
for c := range s.activeConn {
|
||
st, unixSec := c.getState()
|
||
// Issue 22682: treat StateNew connections as if
|
||
// they're idle if we haven't read the first request's
|
||
// header in over 5 seconds.
|
||
if st == StateNew && unixSec < time.Now().Unix()-5 {
|
||
st = StateIdle
|
||
}
|
||
if st != StateIdle || unixSec == 0 {
|
||
// Assume unixSec == 0 means it's a very new
|
||
// connection, without state set yet.
|
||
quiescent = false
|
||
continue
|
||
}
|
||
c.rwc.Close()
|
||
delete(s.activeConn, c)
|
||
}
|
||
return quiescent
|
||
}
|
||
|
||
func (s *Server) closeListenersLocked() error {
|
||
var err error
|
||
for ln := range s.listeners {
|
||
if cerr := (*ln).Close(); cerr != nil && err == nil {
|
||
err = cerr
|
||
}
|
||
}
|
||
return err
|
||
}
|
||
|
||
// 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.
|
||
// For HTTP/2, StateActive fires on the transition from zero
|
||
// to one active request, and only transitions away once all
|
||
// active requests are complete. That means that ConnState
|
||
// cannot be used to do per-request work; ConnState only notes
|
||
// the overall state of the connection.
|
||
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
|
||
}
|
||
|
||
// ServeHTTP should be an internal detail,
|
||
// but widely used packages access it using linkname.
|
||
// Notable members of the hall of shame include:
|
||
// - github.com/erda-project/erda-infra
|
||
//
|
||
// Do not remove or change the type signature.
|
||
// See go.dev/issue/67401.
|
||
//
|
||
//go:linkname badServeHTTP net/http.serverHandler.ServeHTTP
|
||
func (sh serverHandler) ServeHTTP(rw ResponseWriter, req *Request) {
|
||
handler := sh.srv.Handler
|
||
if handler == nil {
|
||
handler = DefaultServeMux
|
||
}
|
||
if !sh.srv.DisableGeneralOptionsHandler && req.RequestURI == "*" && req.Method == "OPTIONS" {
|
||
handler = globalOptionsHandler{}
|
||
}
|
||
|
||
handler.ServeHTTP(rw, req)
|
||
}
|
||
|
||
func badServeHTTP(serverHandler, ResponseWriter, *Request)
|
||
|
||
// AllowQuerySemicolons returns a handler that serves requests by converting any
|
||
// unescaped semicolons in the URL query to ampersands, and invoking the handler h.
|
||
//
|
||
// This restores the pre-Go 1.17 behavior of splitting query parameters on both
|
||
// semicolons and ampersands. (See golang.org/issue/25192). Note that this
|
||
// behavior doesn't match that of many proxies, and the mismatch can lead to
|
||
// security issues.
|
||
//
|
||
// AllowQuerySemicolons should be invoked before [Request.ParseForm] is called.
|
||
func AllowQuerySemicolons(h Handler) Handler {
|
||
return HandlerFunc(func(w ResponseWriter, r *Request) {
|
||
if strings.Contains(r.URL.RawQuery, ";") {
|
||
r2 := new(Request)
|
||
*r2 = *r
|
||
r2.URL = new(url.URL)
|
||
*r2.URL = *r.URL
|
||
r2.URL.RawQuery = strings.ReplaceAll(r.URL.RawQuery, ";", "&")
|
||
h.ServeHTTP(w, r2)
|
||
} else {
|
||
h.ServeHTTP(w, r)
|
||
}
|
||
})
|
||
}
|
||
|
||
// ListenAndServe listens on the TCP network address srv.Addr and then
|
||
// calls [Serve] to handle requests on incoming connections.
|
||
// Accepted connections are configured to enable TCP keep-alives.
|
||
//
|
||
// If srv.Addr is blank, ":http" is used.
|
||
//
|
||
// ListenAndServe always returns a non-nil error. After [Server.Shutdown] or [Server.Close],
|
||
// the returned error is [ErrServerClosed].
|
||
func (srv *Server) ListenAndServe() error {
|
||
if srv.shuttingDown() {
|
||
return ErrServerClosed
|
||
}
|
||
addr := srv.Addr
|
||
if addr == "" {
|
||
addr = ":http"
|
||
}
|
||
ln, err := net.Listen("tcp", addr)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
return srv.Serve(ln)
|
||
}
|
||
|
||
var testHookServerServe func(*Server, net.Listener) // used if non-nil
|
||
|
||
// shouldConfigureHTTP2ForServe reports whether Server.Serve should configure
|
||
// automatic HTTP/2. (which sets up the srv.TLSNextProto map)
|
||
func (srv *Server) shouldConfigureHTTP2ForServe() bool {
|
||
if srv.TLSConfig == nil {
|
||
// Compatibility with Go 1.6:
|
||
// If there's no TLSConfig, it's possible that the user just
|
||
// didn't set it on the http.Server, but did pass it to
|
||
// tls.NewListener and passed that listener to Serve.
|
||
// So we should configure HTTP/2 (to set up srv.TLSNextProto)
|
||
// in case the listener returns an "h2" *tls.Conn.
|
||
return true
|
||
}
|
||
// The user specified a TLSConfig on their http.Server.
|
||
// In this, case, only configure HTTP/2 if their tls.Config
|
||
// explicitly mentions "h2". Otherwise http2.ConfigureServer
|
||
// would modify the tls.Config to add it, but they probably already
|
||
// passed this tls.Config to tls.NewListener. And if they did,
|
||
// it's too late anyway to fix it. It would only be potentially racy.
|
||
// See Issue 15908.
|
||
return slices.Contains(srv.TLSConfig.NextProtos, http2NextProtoTLS)
|
||
}
|
||
|
||
// ErrServerClosed is returned by the [Server.Serve], [ServeTLS], [ListenAndServe],
|
||
// and [ListenAndServeTLS] methods after a call to [Server.Shutdown] or [Server.Close].
|
||
var ErrServerClosed = errors.New("http: Server closed")
|
||
|
||
// 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.
|
||
//
|
||
// HTTP/2 support is only enabled if the Listener returns [*tls.Conn]
|
||
// connections and they were configured with "h2" in the TLS
|
||
// Config.NextProtos.
|
||
//
|
||
// Serve always returns a non-nil error and closes l.
|
||
// After [Server.Shutdown] or [Server.Close], the returned error is [ErrServerClosed].
|
||
func (srv *Server) Serve(l net.Listener) error {
|
||
if fn := testHookServerServe; fn != nil {
|
||
fn(srv, l) // call hook with unwrapped listener
|
||
}
|
||
|
||
origListener := l
|
||
l = &onceCloseListener{Listener: l}
|
||
defer l.Close()
|
||
|
||
if err := srv.setupHTTP2_Serve(); err != nil {
|
||
return err
|
||
}
|
||
|
||
if !srv.trackListener(&l, true) {
|
||
return ErrServerClosed
|
||
}
|
||
defer srv.trackListener(&l, false)
|
||
|
||
baseCtx := context.Background()
|
||
if srv.BaseContext != nil {
|
||
baseCtx = srv.BaseContext(origListener)
|
||
if baseCtx == nil {
|
||
panic("BaseContext returned a nil context")
|
||
}
|
||
}
|
||
|
||
var tempDelay time.Duration // how long to sleep on accept failure
|
||
|
||
ctx := context.WithValue(baseCtx, ServerContextKey, srv)
|
||
for {
|
||
rw, err := l.Accept()
|
||
if err != nil {
|
||
if srv.shuttingDown() {
|
||
return ErrServerClosed
|
||
}
|
||
if ne, ok := err.(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", err, tempDelay)
|
||
time.Sleep(tempDelay)
|
||
continue
|
||
}
|
||
return err
|
||
}
|
||
connCtx := ctx
|
||
if cc := srv.ConnContext; cc != nil {
|
||
connCtx = cc(connCtx, rw)
|
||
if connCtx == nil {
|
||
panic("ConnContext returned nil")
|
||
}
|
||
}
|
||
tempDelay = 0
|
||
c := srv.newConn(rw)
|
||
c.setState(c.rwc, StateNew, runHooks) // before Serve can return
|
||
go c.serve(connCtx)
|
||
}
|
||
}
|
||
|
||
// ServeTLS accepts incoming connections on the Listener l, creating a
|
||
// new service goroutine for each. The service goroutines perform TLS
|
||
// setup and then read requests, calling srv.Handler to reply to them.
|
||
//
|
||
// Files containing a certificate and matching private key for the
|
||
// server must be provided if neither the [Server]'s
|
||
// TLSConfig.Certificates nor TLSConfig.GetCertificate are 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.
|
||
//
|
||
// ServeTLS always returns a non-nil error. After [Server.Shutdown] or [Server.Close], the
|
||
// returned error is [ErrServerClosed].
|
||
func (srv *Server) ServeTLS(l net.Listener, certFile, keyFile string) error {
|
||
// Setup HTTP/2 before srv.Serve, to initialize srv.TLSConfig
|
||
// before we clone it and create the TLS Listener.
|
||
if err := srv.setupHTTP2_ServeTLS(); err != nil {
|
||
return err
|
||
}
|
||
|
||
config := cloneTLSConfig(srv.TLSConfig)
|
||
if !slices.Contains(config.NextProtos, "http/1.1") {
|
||
config.NextProtos = append(config.NextProtos, "http/1.1")
|
||
}
|
||
|
||
configHasCert := len(config.Certificates) > 0 || config.GetCertificate != nil
|
||
if !configHasCert || certFile != "" || keyFile != "" {
|
||
var err error
|
||
config.Certificates = make([]tls.Certificate, 1)
|
||
config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
}
|
||
|
||
tlsListener := tls.NewListener(l, config)
|
||
return srv.Serve(tlsListener)
|
||
}
|
||
|
||
// trackListener adds or removes a net.Listener to the set of tracked
|
||
// listeners.
|
||
//
|
||
// We store a pointer to interface in the map set, in case the
|
||
// net.Listener is not comparable. This is safe because we only call
|
||
// trackListener via Serve and can track+defer untrack the same
|
||
// pointer to local variable there. We never need to compare a
|
||
// Listener from another caller.
|
||
//
|
||
// It reports whether the server is still up (not Shutdown or Closed).
|
||
func (s *Server) trackListener(ln *net.Listener, add bool) bool {
|
||
s.mu.Lock()
|
||
defer s.mu.Unlock()
|
||
if s.listeners == nil {
|
||
s.listeners = make(map[*net.Listener]struct{})
|
||
}
|
||
if add {
|
||
if s.shuttingDown() {
|
||
return false
|
||
}
|
||
s.listeners[ln] = struct{}{}
|
||
s.listenerGroup.Add(1)
|
||
} else {
|
||
delete(s.listeners, ln)
|
||
s.listenerGroup.Done()
|
||
}
|
||
return true
|
||
}
|
||
|
||
func (s *Server) trackConn(c *conn, add bool) {
|
||
s.mu.Lock()
|
||
defer s.mu.Unlock()
|
||
if s.activeConn == nil {
|
||
s.activeConn = make(map[*conn]struct{})
|
||
}
|
||
if add {
|
||
s.activeConn[c] = struct{}{}
|
||
} else {
|
||
delete(s.activeConn, c)
|
||
}
|
||
}
|
||
|
||
func (s *Server) idleTimeout() time.Duration {
|
||
if s.IdleTimeout != 0 {
|
||
return s.IdleTimeout
|
||
}
|
||
return s.ReadTimeout
|
||
}
|
||
|
||
func (s *Server) readHeaderTimeout() time.Duration {
|
||
if s.ReadHeaderTimeout != 0 {
|
||
return s.ReadHeaderTimeout
|
||
}
|
||
return s.ReadTimeout
|
||
}
|
||
|
||
func (s *Server) doKeepAlives() bool {
|
||
return !s.disableKeepAlives.Load() && !s.shuttingDown()
|
||
}
|
||
|
||
func (s *Server) shuttingDown() bool {
|
||
return s.inShutdown.Load()
|
||
}
|
||
|
||
// 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 {
|
||
srv.disableKeepAlives.Store(false)
|
||
return
|
||
}
|
||
srv.disableKeepAlives.Store(true)
|
||
|
||
// Close idle HTTP/1 conns:
|
||
srv.closeIdleConns()
|
||
|
||
// TODO: Issue 26303: close HTTP/2 conns as soon as they become idle.
|
||
}
|
||
|
||
func (s *Server) logf(format string, args ...any) {
|
||
if s.ErrorLog != nil {
|
||
s.ErrorLog.Printf(format, args...)
|
||
} else {
|
||
log.Printf(format, args...)
|
||
}
|
||
}
|
||
|
||
// logf prints to the ErrorLog of the *Server associated with request r
|
||
// via ServerContextKey. If there's no associated server, or if ErrorLog
|
||
// is nil, logging is done via the log package's standard logger.
|
||
func logf(r *Request, format string, args ...any) {
|
||
s, _ := r.Context().Value(ServerContextKey).(*Server)
|
||
if s != nil && 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.
|
||
// Accepted connections are configured to enable TCP keep-alives.
|
||
//
|
||
// The handler is typically nil, in which case [DefaultServeMux] is used.
|
||
//
|
||
// ListenAndServe always returns a non-nil error.
|
||
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.
|
||
func ListenAndServeTLS(addr, certFile, 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 [ServeTLS] to handle requests on incoming TLS connections.
|
||
// Accepted connections are configured to enable TCP keep-alives.
|
||
//
|
||
// Filenames containing a certificate and matching private key for the
|
||
// server must be provided if neither the [Server]'s TLSConfig.Certificates
|
||
// nor TLSConfig.GetCertificate are 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.
|
||
//
|
||
// ListenAndServeTLS always returns a non-nil error. After [Server.Shutdown] or
|
||
// [Server.Close], the returned error is [ErrServerClosed].
|
||
func (srv *Server) ListenAndServeTLS(certFile, keyFile string) error {
|
||
if srv.shuttingDown() {
|
||
return ErrServerClosed
|
||
}
|
||
addr := srv.Addr
|
||
if addr == "" {
|
||
addr = ":https"
|
||
}
|
||
|
||
ln, err := net.Listen("tcp", addr)
|
||
if err != nil {
|
||
return err
|
||
}
|
||
|
||
defer ln.Close()
|
||
|
||
return srv.ServeTLS(ln, certFile, keyFile)
|
||
}
|
||
|
||
// setupHTTP2_ServeTLS conditionally configures HTTP/2 on
|
||
// srv and reports whether there was an error setting it up. If it is
|
||
// not configured for policy reasons, nil is returned.
|
||
func (srv *Server) setupHTTP2_ServeTLS() error {
|
||
srv.nextProtoOnce.Do(srv.onceSetNextProtoDefaults)
|
||
return srv.nextProtoErr
|
||
}
|
||
|
||
// setupHTTP2_Serve is called from (*Server).Serve and conditionally
|
||
// configures HTTP/2 on srv using a more conservative policy than
|
||
// setupHTTP2_ServeTLS because Serve is called after tls.Listen,
|
||
// and may be called concurrently. See shouldConfigureHTTP2ForServe.
|
||
//
|
||
// The tests named TestTransportAutomaticHTTP2* and
|
||
// TestConcurrentServerServe in server_test.go demonstrate some
|
||
// of the supported use cases and motivations.
|
||
func (srv *Server) setupHTTP2_Serve() error {
|
||
srv.nextProtoOnce.Do(srv.onceSetNextProtoDefaults_Serve)
|
||
return srv.nextProtoErr
|
||
}
|
||
|
||
func (srv *Server) onceSetNextProtoDefaults_Serve() {
|
||
if srv.shouldConfigureHTTP2ForServe() {
|
||
srv.onceSetNextProtoDefaults()
|
||
}
|
||
}
|
||
|
||
var http2server = godebug.New("http2server")
|
||
|
||
// onceSetNextProtoDefaults configures HTTP/2, if the user hasn't
|
||
// configured otherwise. (by setting srv.TLSNextProto non-nil)
|
||
// It must only be called via srv.nextProtoOnce (use srv.setupHTTP2_*).
|
||
func (srv *Server) onceSetNextProtoDefaults() {
|
||
if omitBundledHTTP2 {
|
||
return
|
||
}
|
||
if http2server.Value() == "0" {
|
||
http2server.IncNonDefault()
|
||
return
|
||
}
|
||
// Enable HTTP/2 by default if the user hasn't otherwise
|
||
// configured their TLSNextProto map.
|
||
if srv.TLSNextProto == nil {
|
||
conf := &http2Server{
|
||
NewWriteScheduler: func() http2WriteScheduler { return http2NewPriorityWriteScheduler(nil) },
|
||
}
|
||
srv.nextProtoErr = http2ConfigureServer(srv, conf)
|
||
}
|
||
}
|
||
|
||
// 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].
|
||
//
|
||
// TimeoutHandler supports the [Pusher] interface but does not support
|
||
// the [Hijacker] or [Flusher] interfaces.
|
||
func TimeoutHandler(h Handler, dt time.Duration, msg string) Handler {
|
||
return &timeoutHandler{
|
||
handler: h,
|
||
body: msg,
|
||
dt: dt,
|
||
}
|
||
}
|
||
|
||
// 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
|
||
body string
|
||
dt time.Duration
|
||
|
||
// When set, no context will be created and this context will
|
||
// be used instead.
|
||
testContext context.Context
|
||
}
|
||
|
||
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) {
|
||
ctx := h.testContext
|
||
if ctx == nil {
|
||
var cancelCtx context.CancelFunc
|
||
ctx, cancelCtx = context.WithTimeout(r.Context(), h.dt)
|
||
defer cancelCtx()
|
||
}
|
||
r = r.WithContext(ctx)
|
||
done := make(chan struct{})
|
||
tw := &timeoutWriter{
|
||
w: w,
|
||
h: make(Header),
|
||
req: r,
|
||
}
|
||
panicChan := make(chan any, 1)
|
||
go func() {
|
||
defer func() {
|
||
if p := recover(); p != nil {
|
||
panicChan <- p
|
||
}
|
||
}()
|
||
h.handler.ServeHTTP(tw, r)
|
||
close(done)
|
||
}()
|
||
select {
|
||
case p := <-panicChan:
|
||
panic(p)
|
||
case <-done:
|
||
tw.mu.Lock()
|
||
defer tw.mu.Unlock()
|
||
dst := w.Header()
|
||
for k, vv := range tw.h {
|
||
dst[k] = vv
|
||
}
|
||
if !tw.wroteHeader {
|
||
tw.code = StatusOK
|
||
}
|
||
w.WriteHeader(tw.code)
|
||
w.Write(tw.wbuf.Bytes())
|
||
case <-ctx.Done():
|
||
tw.mu.Lock()
|
||
defer tw.mu.Unlock()
|
||
switch err := ctx.Err(); err {
|
||
case context.DeadlineExceeded:
|
||
w.WriteHeader(StatusServiceUnavailable)
|
||
io.WriteString(w, h.errorBody())
|
||
tw.err = ErrHandlerTimeout
|
||
default:
|
||
w.WriteHeader(StatusServiceUnavailable)
|
||
tw.err = err
|
||
}
|
||
}
|
||
}
|
||
|
||
type timeoutWriter struct {
|
||
w ResponseWriter
|
||
h Header
|
||
wbuf bytes.Buffer
|
||
req *Request
|
||
|
||
mu sync.Mutex
|
||
err error
|
||
wroteHeader bool
|
||
code int
|
||
}
|
||
|
||
var _ Pusher = (*timeoutWriter)(nil)
|
||
|
||
// Push implements the [Pusher] interface.
|
||
func (tw *timeoutWriter) Push(target string, opts *PushOptions) error {
|
||
if pusher, ok := tw.w.(Pusher); ok {
|
||
return pusher.Push(target, opts)
|
||
}
|
||
return ErrNotSupported
|
||
}
|
||
|
||
func (tw *timeoutWriter) Header() Header { return tw.h }
|
||
|
||
func (tw *timeoutWriter) Write(p []byte) (int, error) {
|
||
tw.mu.Lock()
|
||
defer tw.mu.Unlock()
|
||
if tw.err != nil {
|
||
return 0, tw.err
|
||
}
|
||
if !tw.wroteHeader {
|
||
tw.writeHeaderLocked(StatusOK)
|
||
}
|
||
return tw.wbuf.Write(p)
|
||
}
|
||
|
||
func (tw *timeoutWriter) writeHeaderLocked(code int) {
|
||
checkWriteHeaderCode(code)
|
||
|
||
switch {
|
||
case tw.err != nil:
|
||
return
|
||
case tw.wroteHeader:
|
||
if tw.req != nil {
|
||
caller := relevantCaller()
|
||
logf(tw.req, "http: superfluous response.WriteHeader call from %s (%s:%d)", caller.Function, path.Base(caller.File), caller.Line)
|
||
}
|
||
default:
|
||
tw.wroteHeader = true
|
||
tw.code = code
|
||
}
|
||
}
|
||
|
||
func (tw *timeoutWriter) WriteHeader(code int) {
|
||
tw.mu.Lock()
|
||
defer tw.mu.Unlock()
|
||
tw.writeHeaderLocked(code)
|
||
}
|
||
|
||
// onceCloseListener wraps a net.Listener, protecting it from
|
||
// multiple Close calls.
|
||
type onceCloseListener struct {
|
||
net.Listener
|
||
once sync.Once
|
||
closeErr error
|
||
}
|
||
|
||
func (oc *onceCloseListener) Close() error {
|
||
oc.once.Do(oc.close)
|
||
return oc.closeErr
|
||
}
|
||
|
||
func (oc *onceCloseListener) close() { oc.closeErr = oc.Listener.Close() }
|
||
|
||
// 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 {
|
||
// Read up to 4KB of OPTIONS body (as mentioned in the
|
||
// spec as being reserved for future use), but anything
|
||
// over that is considered a waste of server resources
|
||
// (or an attack) and we abort and close the connection,
|
||
// courtesy of MaxBytesReader's EOF behavior.
|
||
mb := MaxBytesReader(w, r.Body, 4<<10)
|
||
io.Copy(io.Discard, mb)
|
||
}
|
||
}
|
||
|
||
// initALPNRequest is an HTTP handler that initializes certain
|
||
// uninitialized fields in its *Request. Such partially-initialized
|
||
// Requests come from ALPN protocol handlers.
|
||
type initALPNRequest struct {
|
||
ctx context.Context
|
||
c *tls.Conn
|
||
h serverHandler
|
||
}
|
||
|
||
// BaseContext is an exported but unadvertised [http.Handler] method
|
||
// recognized by x/net/http2 to pass down a context; the TLSNextProto
|
||
// API predates context support so we shoehorn through the only
|
||
// interface we have available.
|
||
func (h initALPNRequest) BaseContext() context.Context { return h.ctx }
|
||
|
||
func (h initALPNRequest) ServeHTTP(rw ResponseWriter, req *Request) {
|
||
if req.TLS == nil {
|
||
req.TLS = &tls.ConnectionState{}
|
||
*req.TLS = h.c.ConnectionState()
|
||
}
|
||
if req.Body == nil {
|
||
req.Body = NoBody
|
||
}
|
||
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.rwc.Write(p)
|
||
if err != nil && w.c.werr == nil {
|
||
w.c.werr = err
|
||
w.c.cancelCtx()
|
||
}
|
||
return
|
||
}
|
||
|
||
func numLeadingCRorLF(v []byte) (n int) {
|
||
for _, b := range v {
|
||
if b == '\r' || b == '\n' {
|
||
n++
|
||
continue
|
||
}
|
||
break
|
||
}
|
||
return
|
||
}
|
||
|
||
// tlsRecordHeaderLooksLikeHTTP reports whether a TLS record header
|
||
// looks like it might've been a misdirected plaintext HTTP request.
|
||
func tlsRecordHeaderLooksLikeHTTP(hdr [5]byte) bool {
|
||
switch string(hdr[:]) {
|
||
case "GET /", "HEAD ", "POST ", "PUT /", "OPTIO":
|
||
return true
|
||
}
|
||
return false
|
||
}
|
||
|
||
// MaxBytesHandler returns a [Handler] that runs h with its [ResponseWriter] and [Request.Body] wrapped by a MaxBytesReader.
|
||
func MaxBytesHandler(h Handler, n int64) Handler {
|
||
return HandlerFunc(func(w ResponseWriter, r *Request) {
|
||
r2 := *r
|
||
r2.Body = MaxBytesReader(w, r.Body, n)
|
||
h.ServeHTTP(w, &r2)
|
||
})
|
||
}
|