4f4a855d82
Reviewed-on: https://go-review.googlesource.com/c/158019 gotools/: * Makefile.am (go_cmd_vet_files): Update for Go1.12beta2 release. (GOTOOLS_TEST_TIMEOUT): Increase to 600. (check-runtime): Export LD_LIBRARY_PATH before computing GOARCH and GOOS. (check-vet): Copy golang.org/x/tools into check-vet-dir. * Makefile.in: Regenerate. gcc/testsuite/: * go.go-torture/execute/names-1.go: Stop using debug/xcoff, which is no longer externally visible. From-SVN: r268084
3419 lines
103 KiB
Go
3419 lines
103 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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"io"
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"io/ioutil"
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"log"
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"net"
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"net/textproto"
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"net/url"
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"os"
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"path"
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"runtime"
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"sort"
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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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"internal/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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// 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 the Handler.ServeHTTP method
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// 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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// WriteHeader. The Header map also is the mechanism with which
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// Handlers can set HTTP trailers.
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//
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// Changing the header map after a call to WriteHeader (or
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// Write) has no effect unless the modified headers are
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// 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 Write,
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// is to prefix the Header map keys with the TrailerPrefix
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// constant value. See TrailerPrefix.
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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 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.
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//
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// The provided code must be a valid HTTP 1xx-5xx status code.
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// Only one header may be written. Go does not currently
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// support sending user-defined 1xx informational headers,
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// with the exception of 100-continue response header that the
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// Server sends automatically when the Request.Body is read.
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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 a 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.WithValue 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.WithValue 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.Value // of *response (which has a Request in it)
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curState struct{ 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)
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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.bufw 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() {
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if !cw.wroteHeader {
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cw.writeHeader(nil)
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}
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cw.res.conn.bufw.Flush()
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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
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// 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 {
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trailers.Write(bw) // the writer handles noting errors
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}
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// final blank line after the trailers (whether
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// present or not)
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bw.WriteString("\r\n")
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}
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}
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// A response represents the server side of an HTTP response.
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type response struct {
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conn *conn
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req *Request // request for this response
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reqBody io.ReadCloser
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cancelCtx context.CancelFunc // when ServeHTTP exits
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wroteHeader bool // reply header has been (logically) written
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wroteContinue bool // 100 Continue response was written
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wants10KeepAlive bool // HTTP/1.0 w/ Connection "keep-alive"
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wantsClose bool // HTTP request has Connection "close"
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w *bufio.Writer // buffers output in chunks to chunkWriter
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cw chunkWriter
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// handlerHeader is the Header that Handlers get access to,
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// which may be retained and mutated even after WriteHeader.
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// handlerHeader is copied into cw.header at WriteHeader
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// time, and privately mutated thereafter.
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handlerHeader Header
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calledHeader bool // handler accessed handlerHeader via Header
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written int64 // number of bytes written in body
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contentLength int64 // explicitly-declared Content-Length; or -1
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status int // status code passed to WriteHeader
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// close connection after this reply. set on request and
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// updated after response from handler if there's a
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// "Connection: keep-alive" response header and a
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// Content-Length.
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closeAfterReply bool
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// requestBodyLimitHit is set by requestTooLarge when
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// maxBytesReader hits its max size. It is checked in
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// WriteHeader, to make sure we don't consume the
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// remaining request body to try to advance to the next HTTP
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// request. Instead, when this is set, we stop reading
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// subsequent requests on this connection and stop reading
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// input from it.
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requestBodyLimitHit bool
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// trailers are the headers to be sent after the handler
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// finishes writing the body. This field is initialized from
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// the Trailer response header when the response header is
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// written.
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trailers []string
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handlerDone atomicBool // set true when the handler exits
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// Buffers for Date, Content-Length, and status code
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dateBuf [len(TimeFormat)]byte
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clenBuf [10]byte
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statusBuf [3]byte
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// closeNotifyCh is the channel returned by CloseNotify.
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// TODO(bradfitz): this is currently (for Go 1.8) always
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// non-nil. Make this lazily-created again as it used to be?
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closeNotifyCh chan bool
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didCloseNotify int32 // atomic (only 0->1 winner should send)
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}
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// TrailerPrefix is a magic prefix for ResponseWriter.Header map keys
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// that, if present, signals that the map entry is actually for
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// the response trailers, and not the response headers. The prefix
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// is stripped after the ServeHTTP call finishes and the values are
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// sent in the trailers.
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//
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// This mechanism is intended only for trailers that are not known
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// prior to the headers being written. If the set of trailers is fixed
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// or known before the header is written, the normal Go trailers mechanism
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// is preferred:
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// https://golang.org/pkg/net/http/#ResponseWriter
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// https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
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const TrailerPrefix = "Trailer:"
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// finalTrailers is called after the Handler exits and returns a non-nil
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// value if the Handler set any trailers.
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func (w *response) finalTrailers() Header {
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var t Header
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for k, vv := range w.handlerHeader {
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if strings.HasPrefix(k, TrailerPrefix) {
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if t == nil {
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t = make(Header)
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}
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t[strings.TrimPrefix(k, TrailerPrefix)] = vv
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}
|
|
}
|
|
for _, k := range w.trailers {
|
|
if t == nil {
|
|
t = make(Header)
|
|
}
|
|
for _, v := range w.handlerHeader[k] {
|
|
t.Add(k, v)
|
|
}
|
|
}
|
|
return t
|
|
}
|
|
|
|
type atomicBool int32
|
|
|
|
func (b *atomicBool) isSet() bool { return atomic.LoadInt32((*int32)(b)) != 0 }
|
|
func (b *atomicBool) setTrue() { atomic.StoreInt32((*int32)(b), 1) }
|
|
|
|
// 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")
|
|
}
|
|
}
|
|
|
|
// needsSniff reports whether a Content-Type still needs to be sniffed.
|
|
func (w *response) needsSniff() bool {
|
|
_, haveType := w.handlerHeader["Content-Type"]
|
|
return !w.cw.wroteHeader && !haveType && w.written < sniffLen
|
|
}
|
|
|
|
// writerOnly hides an io.Writer value's optional ReadFrom method
|
|
// from io.Copy.
|
|
type writerOnly struct {
|
|
io.Writer
|
|
}
|
|
|
|
func srcIsRegularFile(src io.Reader) (isRegular bool, err error) {
|
|
switch v := src.(type) {
|
|
case *os.File:
|
|
fi, err := v.Stat()
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
return fi.Mode().IsRegular(), nil
|
|
case *io.LimitedReader:
|
|
return srcIsRegularFile(v.R)
|
|
default:
|
|
return
|
|
}
|
|
}
|
|
|
|
// ReadFrom is here to optimize copying from an *os.File regular file
|
|
// to a *net.TCPConn with sendfile.
|
|
func (w *response) ReadFrom(src io.Reader) (n int64, err error) {
|
|
// Our underlying w.conn.rwc is usually a *TCPConn (with its
|
|
// own ReadFrom method). If not, or if our src isn't a regular
|
|
// file, just fall back to the normal copy method.
|
|
rf, ok := w.conn.rwc.(io.ReaderFrom)
|
|
regFile, err := srcIsRegularFile(src)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
if !ok || !regFile {
|
|
bufp := copyBufPool.Get().(*[]byte)
|
|
defer copyBufPool.Put(bufp)
|
|
return io.CopyBuffer(writerOnly{w}, src, *bufp)
|
|
}
|
|
|
|
// sendfile path:
|
|
|
|
if !w.wroteHeader {
|
|
w.WriteHeader(StatusOK)
|
|
}
|
|
|
|
if w.needsSniff() {
|
|
n0, err := io.Copy(writerOnly{w}, io.LimitReader(src, sniffLen))
|
|
n += n0
|
|
if err != nil {
|
|
return n, err
|
|
}
|
|
}
|
|
|
|
w.w.Flush() // 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.Copy(writerOnly{w}, src)
|
|
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 {
|
|
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().(*response)
|
|
if res != nil {
|
|
if atomic.CompareAndSwapInt32(&res.didCloseNotify, 0, 1) {
|
|
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
|
|
)
|
|
|
|
var copyBufPool = sync.Pool{
|
|
New: func() interface{} {
|
|
b := make([]byte, 32*1024)
|
|
return &b
|
|
},
|
|
}
|
|
|
|
func bufioWriterPool(size int) *sync.Pool {
|
|
switch size {
|
|
case 2 << 10:
|
|
return &bufioWriter2kPool
|
|
case 4 << 10:
|
|
return &bufioWriter4kPool
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func newBufioReader(r io.Reader) *bufio.Reader {
|
|
if v := bufioReaderPool.Get(); v != nil {
|
|
br := v.(*bufio.Reader)
|
|
br.Reset(r)
|
|
return br
|
|
}
|
|
// Note: if this reader size is ever changed, update
|
|
// TestHandlerBodyClose's assumptions.
|
|
return bufio.NewReader(r)
|
|
}
|
|
|
|
func putBufioReader(br *bufio.Reader) {
|
|
br.Reset(nil)
|
|
bufioReaderPool.Put(br)
|
|
}
|
|
|
|
func newBufioWriterSize(w io.Writer, size int) *bufio.Writer {
|
|
pool := bufioWriterPool(size)
|
|
if pool != nil {
|
|
if v := pool.Get(); v != nil {
|
|
bw := v.(*bufio.Writer)
|
|
bw.Reset(w)
|
|
return bw
|
|
}
|
|
}
|
|
return bufio.NewWriterSize(w, size)
|
|
}
|
|
|
|
func putBufioWriter(bw *bufio.Writer) {
|
|
bw.Reset(nil)
|
|
if pool := bufioWriterPool(bw.Available()); pool != nil {
|
|
pool.Put(bw)
|
|
}
|
|
}
|
|
|
|
// DefaultMaxHeaderBytes is the maximum permitted size of the headers
|
|
// in an HTTP request.
|
|
// This can be overridden by setting Server.MaxHeaderBytes.
|
|
const DefaultMaxHeaderBytes = 1 << 20 // 1 MB
|
|
|
|
func (srv *Server) maxHeaderBytes() int {
|
|
if srv.MaxHeaderBytes > 0 {
|
|
return srv.MaxHeaderBytes
|
|
}
|
|
return DefaultMaxHeaderBytes
|
|
}
|
|
|
|
func (srv *Server) initialReadLimitSize() int64 {
|
|
return int64(srv.maxHeaderBytes()) + 4096 // bufio slop
|
|
}
|
|
|
|
// 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 bool
|
|
sawEOF bool
|
|
}
|
|
|
|
func (ecr *expectContinueReader) Read(p []byte) (n int, err error) {
|
|
if ecr.closed {
|
|
return 0, ErrBodyReadAfterClose
|
|
}
|
|
if !ecr.resp.wroteContinue && !ecr.resp.conn.hijacked() {
|
|
ecr.resp.wroteContinue = true
|
|
ecr.resp.conn.bufw.WriteString("HTTP/1.1 100 Continue\r\n\r\n")
|
|
ecr.resp.conn.bufw.Flush()
|
|
}
|
|
n, err = ecr.readCloser.Read(p)
|
|
if err == io.EOF {
|
|
ecr.sawEOF = true
|
|
}
|
|
return
|
|
}
|
|
|
|
func (ecr *expectContinueReader) Close() error {
|
|
ecr.closed = true
|
|
return ecr.readCloser.Close()
|
|
}
|
|
|
|
// TimeFormat is the time format to use 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, keepHostHeader)
|
|
if err != nil {
|
|
if c.r.hitReadLimit() {
|
|
return nil, errTooLarge
|
|
}
|
|
return nil, err
|
|
}
|
|
|
|
if !http1ServerSupportsRequest(req) {
|
|
return nil, badRequestError("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 {
|
|
return nil, badRequestError("too many Host headers")
|
|
}
|
|
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 then the server to be paranoid instead sends a "Connection:
|
|
// close" response.
|
|
//
|
|
// This number is approximately what a typical machine's TCP buffer
|
|
// size is anyway. (if we have the bytes on the machine, we might as
|
|
// well read them)
|
|
const maxPostHandlerReadBytes = 256 << 10
|
|
|
|
func 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)
|
|
// and we might block under 200 (once we have more mature 1xx support).
|
|
// 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])
|
|
prefix1 := "net/http."
|
|
prefix2 := "net/http."
|
|
if runtime.Compiler == "gccgo" {
|
|
prefix2 = "http."
|
|
}
|
|
var frame runtime.Frame
|
|
for {
|
|
frame, more := frames.Next()
|
|
if !strings.HasPrefix(frame.Function, prefix1) && !strings.HasPrefix(frame.Function, prefix2) {
|
|
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)
|
|
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.isSet() && !trailers && !hasTE && bodyAllowedForStatus(w.status) && header.get("Content-Length") == "" && (!isHEAD || len(p) > 0) {
|
|
w.contentLength = int64(len(p))
|
|
setHeader.contentLength = strconv.AppendInt(cw.res.clenBuf[:0], int64(len(p)), 10)
|
|
}
|
|
|
|
// If 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 {
|
|
w.closeAfterReply = true
|
|
}
|
|
|
|
// Per RFC 2616, we should consume the request body before
|
|
// replying, if the handler hasn't already done so. But we
|
|
// don't want to do an unbounded amount of reading here for
|
|
// DoS reasons, so we only try up to a threshold.
|
|
// TODO(bradfitz): where does RFC 2616 say that? See Issue 15527
|
|
// about HTTP/1.x Handlers concurrently reading and writing, like
|
|
// HTTP/2 handlers can do. Maybe this code should be relaxed?
|
|
if w.req.ContentLength != 0 && !w.closeAfterReply {
|
|
var discard, tooBig bool
|
|
|
|
switch bdy := w.req.Body.(type) {
|
|
case *expectContinueReader:
|
|
if bdy.resp.wroteContinue {
|
|
discard = true
|
|
}
|
|
case *body:
|
|
bdy.mu.Lock()
|
|
switch {
|
|
case bdy.closed:
|
|
if !bdy.sawEOF {
|
|
// 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(ioutil.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 !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) {
|
|
// do nothing
|
|
} else if code == StatusNoContent {
|
|
delHeader("Transfer-Encoding")
|
|
} else if hasCL {
|
|
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
|
|
} 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
|
|
}
|
|
|
|
if w.closeAfterReply && (!keepAlivesEnabled || !hasToken(cw.header.get("Connection"), "close")) {
|
|
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, ok := statusText[code]; ok {
|
|
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.buf, a bufio.Writer of default (4kB) bytes, writing to ->
|
|
// 5. checkConnErrorWriter{c}, which notes any non-nil error on Write
|
|
// and populates c.werr with it if so. but otherwise writes to:
|
|
// 6. the rwc, the net.Conn.
|
|
//
|
|
// TODO(bradfitz): short-circuit some of the buffering when the
|
|
// initial header contains both a Content-Type and Content-Length.
|
|
// Also short-circuit in (1) when the header's been sent and not in
|
|
// chunking mode, writing directly to (4) instead, if (2) has no
|
|
// buffered data. More generally, we could short-circuit from (1) to
|
|
// (3) even in chunking mode if the write size from (1) is over some
|
|
// threshold and nothing is in (2). The answer might be mostly making
|
|
// bufferBeforeChunkingSize smaller and having bufio's fast-paths deal
|
|
// with this instead.
|
|
func (w *response) Write(data []byte) (n int, err error) {
|
|
return w.write(len(data), data, "")
|
|
}
|
|
|
|
func (w *response) WriteString(data string) (n int, err error) {
|
|
return w.write(len(data), nil, data)
|
|
}
|
|
|
|
// either dataB or dataS is non-zero.
|
|
func (w *response) write(lenData int, dataB []byte, dataS string) (n int, err error) {
|
|
if w.conn.hijacked() {
|
|
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.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.setTrue()
|
|
|
|
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() {
|
|
if !w.wroteHeader {
|
|
w.WriteHeader(StatusOK)
|
|
}
|
|
w.w.Flush()
|
|
w.cw.flush()
|
|
}
|
|
|
|
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).
|
|
const rstAvoidanceDelay = 500 * time.Millisecond
|
|
|
|
type closeWriter interface {
|
|
CloseWrite() error
|
|
}
|
|
|
|
var _ closeWriter = (*net.TCPConn)(nil)
|
|
|
|
// closeWrite flushes any outstanding data and sends a FIN packet (if
|
|
// client is connected via TCP), signalling that we're done. We then
|
|
// pause for a bit, hoping the client processes it before any
|
|
// subsequent RST.
|
|
//
|
|
// See https://golang.org/issue/3595
|
|
func (c *conn) closeWriteAndWait() {
|
|
c.finalFlush()
|
|
if tcp, ok := c.rwc.(closeWriter); ok {
|
|
tcp.CloseWrite()
|
|
}
|
|
time.Sleep(rstAvoidanceDelay)
|
|
}
|
|
|
|
// validNPN reports whether the proto is not a blacklisted Next
|
|
// Protocol Negotiation protocol. Empty and built-in protocol types
|
|
// are blacklisted and can't be overridden with alternate
|
|
// implementations.
|
|
func validNPN(proto string) bool {
|
|
switch proto {
|
|
case "", "http/1.1", "http/1.0":
|
|
return false
|
|
}
|
|
return true
|
|
}
|
|
|
|
func (c *conn) setState(nc net.Conn, state ConnState) {
|
|
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)
|
|
atomic.StoreUint64(&c.curState.atomic, packedState)
|
|
if hook := srv.ConnState; hook != nil {
|
|
hook(nc, state)
|
|
}
|
|
}
|
|
|
|
func (c *conn) getState() (state ConnState, unixSec int64) {
|
|
packedState := atomic.LoadUint64(&c.curState.atomic)
|
|
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.
|
|
type badRequestError string
|
|
|
|
func (e badRequestError) Error() string { return "Bad Request: " + string(e) }
|
|
|
|
// 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) {
|
|
c.remoteAddr = c.rwc.RemoteAddr().String()
|
|
ctx = context.WithValue(ctx, LocalAddrContextKey, c.rwc.LocalAddr())
|
|
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 !c.hijacked() {
|
|
c.close()
|
|
c.setState(c.rwc, StateClosed)
|
|
}
|
|
}()
|
|
|
|
if tlsConn, ok := c.rwc.(*tls.Conn); ok {
|
|
if d := c.server.ReadTimeout; d != 0 {
|
|
c.rwc.SetReadDeadline(time.Now().Add(d))
|
|
}
|
|
if d := c.server.WriteTimeout; d != 0 {
|
|
c.rwc.SetWriteDeadline(time.Now().Add(d))
|
|
}
|
|
if err := tlsConn.Handshake(); err != nil {
|
|
// 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.
|
|
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()
|
|
return
|
|
}
|
|
c.server.logf("http: TLS handshake error from %s: %v", c.rwc.RemoteAddr(), err)
|
|
return
|
|
}
|
|
c.tlsState = new(tls.ConnectionState)
|
|
*c.tlsState = tlsConn.ConnectionState()
|
|
if proto := c.tlsState.NegotiatedProtocol; validNPN(proto) {
|
|
if fn := c.server.TLSNextProto[proto]; fn != nil {
|
|
h := initNPNRequest{tlsConn, serverHandler{c.server}}
|
|
fn(c.server, tlsConn, h)
|
|
}
|
|
return
|
|
}
|
|
}
|
|
|
|
// 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)
|
|
}
|
|
if err != nil {
|
|
const errorHeaders = "\r\nContent-Type: text/plain; charset=utf-8\r\nConnection: close\r\n\r\n"
|
|
|
|
if 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
|
|
}
|
|
if isCommonNetReadError(err) {
|
|
return // don't reply
|
|
}
|
|
|
|
publicErr := "400 Bad Request"
|
|
if v, ok := err.(badRequestError); ok {
|
|
publicErr = publicErr + ": " + string(v)
|
|
}
|
|
|
|
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}
|
|
}
|
|
} 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.
|
|
serverHandler{c.server}.ServeHTTP(w, w.req)
|
|
w.cancelCtx()
|
|
if c.hijacked() {
|
|
return
|
|
}
|
|
w.finishRequest()
|
|
if !w.shouldReuseConnection() {
|
|
if w.requestBodyLimitHit || w.closedRequestBodyEarly() {
|
|
c.closeWriteAndWait()
|
|
}
|
|
return
|
|
}
|
|
c.setState(c.rwc, StateIdle)
|
|
c.curReq.Store((*response)(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))
|
|
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.isSet() {
|
|
panic("net/http: Hijack called after ServeHTTP finished")
|
|
}
|
|
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.isSet() {
|
|
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.
|
|
func Error(w ResponseWriter, error string, code int) {
|
|
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
|
|
w.Header().Set("X-Content-Type-Options", "nosniff")
|
|
w.WriteHeader(code)
|
|
fmt.Fprintln(w, error)
|
|
}
|
|
|
|
// NotFound replies to the request with an HTTP 404 not found error.
|
|
func NotFound(w ResponseWriter, r *Request) { Error(w, "404 page not found", StatusNotFound) }
|
|
|
|
// NotFoundHandler returns a simple request handler
|
|
// that replies to each request with a ``404 page not found'' reply.
|
|
func NotFoundHandler() Handler { return HandlerFunc(NotFound) }
|
|
|
|
// StripPrefix returns a handler that serves HTTP requests
|
|
// by removing the given prefix from the request URL's Path
|
|
// and invoking the handler h. StripPrefix handles a
|
|
// request for a path that doesn't begin with prefix by
|
|
// replying with an HTTP 404 not found error.
|
|
func StripPrefix(prefix string, h Handler) Handler {
|
|
if prefix == "" {
|
|
return h
|
|
}
|
|
return HandlerFunc(func(w ResponseWriter, r *Request) {
|
|
if p := strings.TrimPrefix(r.URL.Path, prefix); len(p) < len(r.URL.Path) {
|
|
r2 := new(Request)
|
|
*r2 = *r
|
|
r2.URL = new(url.URL)
|
|
*r2.URL = *r.URL
|
|
r2.URL.Path = p
|
|
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) {
|
|
// parseURL is just url.Parse (url is shadowed for godoc).
|
|
if u, err := parseURL(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)
|
|
}
|
|
}
|
|
|
|
// parseURL is just url.Parse. It exists only so that url.Parse can be called
|
|
// in places where url is shadowed for godoc. See https://golang.org/cl/49930.
|
|
var parseURL = url.Parse
|
|
|
|
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 name fixed, rooted paths, like "/favicon.ico",
|
|
// or rooted subtrees, like "/images/" (note the trailing slash).
|
|
// Longer patterns take precedence over shorter ones, so that
|
|
// if there are handlers registered for both "/images/"
|
|
// and "/images/thumbnails/", the latter handler will be
|
|
// called for paths beginning "/images/thumbnails/" and the
|
|
// former will receive requests for any other paths in the
|
|
// "/images/" subtree.
|
|
//
|
|
// Note that since a pattern ending in a slash names a rooted subtree,
|
|
// the pattern "/" matches all paths not matched by other registered
|
|
// patterns, not just the URL with Path == "/".
|
|
//
|
|
// If a subtree has been registered and a request is received naming the
|
|
// subtree root without its trailing slash, ServeMux redirects that
|
|
// request to the subtree root (adding the trailing slash). This behavior can
|
|
// be overridden with a separate registration for the path without
|
|
// the trailing slash. For example, registering "/images/" causes ServeMux
|
|
// to redirect a request for "/images" to "/images/", unless "/images" has
|
|
// been registered separately.
|
|
//
|
|
// Patterns may optionally begin with a host name, restricting matches to
|
|
// URLs on that host only. Host-specific patterns take precedence over
|
|
// general patterns, so that a handler might register for the two patterns
|
|
// "/codesearch" and "codesearch.google.com/" without also taking over
|
|
// requests for "http://www.google.com/".
|
|
//
|
|
// ServeMux also takes care of sanitizing the URL request path and the Host
|
|
// header, stripping the port number and redirecting any request containing . or
|
|
// .. elements or repeated slashes to an equivalent, cleaner URL.
|
|
type ServeMux struct {
|
|
mu sync.RWMutex
|
|
m map[string]muxEntry
|
|
es []muxEntry // slice of entries sorted from longest to shortest.
|
|
hosts bool // whether any patterns contain hostnames
|
|
}
|
|
|
|
type muxEntry struct {
|
|
h Handler
|
|
pattern string
|
|
}
|
|
|
|
// NewServeMux allocates and returns a new ServeMux.
|
|
func NewServeMux() *ServeMux { return new(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.IndexByte(h, ':') == -1 {
|
|
return h
|
|
}
|
|
host, _, err := net.SplitHostPort(h)
|
|
if err != nil {
|
|
return h // on error, return unchanged
|
|
}
|
|
return host
|
|
}
|
|
|
|
// Find a handler on a handler map given a path string.
|
|
// Most-specific (longest) pattern wins.
|
|
func (mux *ServeMux) match(path string) (h Handler, pattern string) {
|
|
// Check for exact match first.
|
|
v, ok := mux.m[path]
|
|
if ok {
|
|
return v.h, v.pattern
|
|
}
|
|
|
|
// Check for longest valid match. mux.es contains all patterns
|
|
// that end in / sorted from longest to shortest.
|
|
for _, e := range mux.es {
|
|
if strings.HasPrefix(path, e.pattern) {
|
|
return e.h, e.pattern
|
|
}
|
|
}
|
|
return nil, ""
|
|
}
|
|
|
|
// redirectToPathSlash determines if the given path needs appending "/" to it.
|
|
// This occurs when a handler for path + "/" was already registered, but
|
|
// not for path itself. If the path needs appending to, it creates a new
|
|
// URL, setting the path to u.Path + "/" and returning true to indicate so.
|
|
func (mux *ServeMux) redirectToPathSlash(host, path string, u *url.URL) (*url.URL, bool) {
|
|
mux.mu.RLock()
|
|
shouldRedirect := mux.shouldRedirectRLocked(host, path)
|
|
mux.mu.RUnlock()
|
|
if !shouldRedirect {
|
|
return u, false
|
|
}
|
|
path = path + "/"
|
|
u = &url.URL{Path: path, RawQuery: u.RawQuery}
|
|
return u, true
|
|
}
|
|
|
|
// shouldRedirectRLocked reports whether the given path and host should be redirected to
|
|
// path+"/". This should happen if a handler is registered for path+"/" but
|
|
// not path -- see comments at ServeMux.
|
|
func (mux *ServeMux) shouldRedirectRLocked(host, path string) bool {
|
|
p := []string{path, host + path}
|
|
|
|
for _, c := range p {
|
|
if _, exist := mux.m[c]; exist {
|
|
return false
|
|
}
|
|
}
|
|
|
|
n := len(path)
|
|
if n == 0 {
|
|
return false
|
|
}
|
|
for _, c := range p {
|
|
if _, exist := mux.m[c+"/"]; exist {
|
|
return path[n-1] != '/'
|
|
}
|
|
}
|
|
|
|
return false
|
|
}
|
|
|
|
// 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 pattern that will match after following the redirect.
|
|
//
|
|
// If there is no registered handler that applies to the request,
|
|
// Handler returns a ``page not found'' handler and an empty pattern.
|
|
func (mux *ServeMux) Handler(r *Request) (h Handler, pattern string) {
|
|
|
|
// 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.
|
|
if u, ok := mux.redirectToPathSlash(r.URL.Host, r.URL.Path, r.URL); ok {
|
|
return RedirectHandler(u.String(), StatusMovedPermanently), u.Path
|
|
}
|
|
|
|
return mux.handler(r.Host, r.URL.Path)
|
|
}
|
|
|
|
// All other requests have any port stripped and path cleaned
|
|
// before passing to mux.handler.
|
|
host := stripHostPort(r.Host)
|
|
path := cleanPath(r.URL.Path)
|
|
|
|
// If the given path is /tree and its handler is not registered,
|
|
// redirect for /tree/.
|
|
if u, ok := mux.redirectToPathSlash(host, path, r.URL); ok {
|
|
return RedirectHandler(u.String(), StatusMovedPermanently), u.Path
|
|
}
|
|
|
|
if path != r.URL.Path {
|
|
_, pattern = mux.handler(host, path)
|
|
url := *r.URL
|
|
url.Path = path
|
|
return RedirectHandler(url.String(), StatusMovedPermanently), pattern
|
|
}
|
|
|
|
return mux.handler(host, r.URL.Path)
|
|
}
|
|
|
|
// handler is the main implementation of Handler.
|
|
// The path is known to be in canonical form, except for CONNECT methods.
|
|
func (mux *ServeMux) handler(host, path string) (h Handler, pattern string) {
|
|
mux.mu.RLock()
|
|
defer mux.mu.RUnlock()
|
|
|
|
// Host-specific pattern takes precedence over generic ones
|
|
if mux.hosts {
|
|
h, pattern = mux.match(host + path)
|
|
}
|
|
if h == nil {
|
|
h, pattern = mux.match(path)
|
|
}
|
|
if h == nil {
|
|
h, pattern = NotFoundHandler(), ""
|
|
}
|
|
return
|
|
}
|
|
|
|
// ServeHTTP dispatches the request to the handler whose
|
|
// pattern most closely matches the request URL.
|
|
func (mux *ServeMux) ServeHTTP(w ResponseWriter, r *Request) {
|
|
if r.RequestURI == "*" {
|
|
if r.ProtoAtLeast(1, 1) {
|
|
w.Header().Set("Connection", "close")
|
|
}
|
|
w.WriteHeader(StatusBadRequest)
|
|
return
|
|
}
|
|
h, _ := mux.Handler(r)
|
|
h.ServeHTTP(w, r)
|
|
}
|
|
|
|
// Handle registers the handler for the given pattern.
|
|
// If a handler already exists for pattern, Handle panics.
|
|
func (mux *ServeMux) Handle(pattern string, handler Handler) {
|
|
mux.mu.Lock()
|
|
defer mux.mu.Unlock()
|
|
|
|
if pattern == "" {
|
|
panic("http: invalid pattern")
|
|
}
|
|
if handler == nil {
|
|
panic("http: nil handler")
|
|
}
|
|
if _, exist := mux.m[pattern]; exist {
|
|
panic("http: multiple registrations for " + pattern)
|
|
}
|
|
|
|
if mux.m == nil {
|
|
mux.m = make(map[string]muxEntry)
|
|
}
|
|
e := muxEntry{h: handler, pattern: pattern}
|
|
mux.m[pattern] = e
|
|
if pattern[len(pattern)-1] == '/' {
|
|
mux.es = appendSorted(mux.es, e)
|
|
}
|
|
|
|
if pattern[0] != '/' {
|
|
mux.hosts = true
|
|
}
|
|
}
|
|
|
|
func appendSorted(es []muxEntry, e muxEntry) []muxEntry {
|
|
n := len(es)
|
|
i := sort.Search(n, func(i int) bool {
|
|
return len(es[i].pattern) < len(e.pattern)
|
|
})
|
|
if i == n {
|
|
return append(es, e)
|
|
}
|
|
// we now know that i points at where we want to insert
|
|
es = append(es, muxEntry{}) // try to grow the slice in place, any entry works.
|
|
copy(es[i+1:], es[i:]) // Move shorter entries down
|
|
es[i] = e
|
|
return es
|
|
}
|
|
|
|
// HandleFunc registers the handler function for the given pattern.
|
|
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
|
|
if handler == nil {
|
|
panic("http: nil handler")
|
|
}
|
|
mux.Handle(pattern, HandlerFunc(handler))
|
|
}
|
|
|
|
// Handle registers the handler for the given pattern
|
|
// in the DefaultServeMux.
|
|
// The documentation for ServeMux explains how patterns are matched.
|
|
func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, handler) }
|
|
|
|
// HandleFunc registers the handler function for the given pattern
|
|
// in the DefaultServeMux.
|
|
// The documentation for ServeMux explains how patterns are matched.
|
|
func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
|
|
DefaultServeMux.HandleFunc(pattern, handler)
|
|
}
|
|
|
|
// Serve accepts incoming HTTP connections on the listener l,
|
|
// creating a new service goroutine for each. The service goroutines
|
|
// read requests and then call handler to reply to them.
|
|
//
|
|
// The handler is typically nil, in which case the 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 the 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 string // TCP address to listen on, ":http" if empty
|
|
Handler Handler // handler to invoke, http.DefaultServeMux if nil
|
|
|
|
// 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.
|
|
//
|
|
// 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.
|
|
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.
|
|
WriteTimeout time.Duration
|
|
|
|
// IdleTimeout is the maximum amount of time to wait for the
|
|
// next request when keep-alives are enabled. If IdleTimeout
|
|
// is zero, the value of ReadTimeout is used. If both are
|
|
// zero, ReadHeaderTimeout is used.
|
|
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 NPN/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
|
|
|
|
disableKeepAlives int32 // accessed atomically.
|
|
inShutdown int32 // accessed atomically (non-zero means we're in Shutdown)
|
|
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{}
|
|
doneChan chan struct{}
|
|
onShutdown []func()
|
|
}
|
|
|
|
func (s *Server) getDoneChan() <-chan struct{} {
|
|
s.mu.Lock()
|
|
defer s.mu.Unlock()
|
|
return s.getDoneChanLocked()
|
|
}
|
|
|
|
func (s *Server) getDoneChanLocked() chan struct{} {
|
|
if s.doneChan == nil {
|
|
s.doneChan = make(chan struct{})
|
|
}
|
|
return s.doneChan
|
|
}
|
|
|
|
func (s *Server) closeDoneChanLocked() {
|
|
ch := s.getDoneChanLocked()
|
|
select {
|
|
case <-ch:
|
|
// Already closed. Don't close again.
|
|
default:
|
|
// Safe to close here. We're the only closer, guarded
|
|
// by s.mu.
|
|
close(ch)
|
|
}
|
|
}
|
|
|
|
// Close immediately closes all active net.Listeners and any
|
|
// connections in state StateNew, StateActive, or StateIdle. For a
|
|
// graceful shutdown, use 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 {
|
|
atomic.StoreInt32(&srv.inShutdown, 1)
|
|
srv.mu.Lock()
|
|
defer srv.mu.Unlock()
|
|
srv.closeDoneChanLocked()
|
|
err := srv.closeListenersLocked()
|
|
for c := range srv.activeConn {
|
|
c.rwc.Close()
|
|
delete(srv.activeConn, c)
|
|
}
|
|
return err
|
|
}
|
|
|
|
// shutdownPollInterval is how often we poll for quiescence
|
|
// during Server.Shutdown. This is lower during tests, to
|
|
// speed up tests.
|
|
// 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.
|
|
var shutdownPollInterval = 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 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 {
|
|
atomic.StoreInt32(&srv.inShutdown, 1)
|
|
|
|
srv.mu.Lock()
|
|
lnerr := srv.closeListenersLocked()
|
|
srv.closeDoneChanLocked()
|
|
for _, f := range srv.onShutdown {
|
|
go f()
|
|
}
|
|
srv.mu.Unlock()
|
|
|
|
ticker := time.NewTicker(shutdownPollInterval)
|
|
defer ticker.Stop()
|
|
for {
|
|
if srv.closeIdleConns() {
|
|
return lnerr
|
|
}
|
|
select {
|
|
case <-ctx.Done():
|
|
return ctx.Err()
|
|
case <-ticker.C:
|
|
}
|
|
}
|
|
}
|
|
|
|
// RegisterOnShutdown registers a function to call on Shutdown.
|
|
// This can be used to gracefully shutdown connections that have
|
|
// undergone NPN/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
|
|
}
|
|
delete(s.listeners, ln)
|
|
}
|
|
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
|
|
}
|
|
|
|
func (sh serverHandler) ServeHTTP(rw ResponseWriter, req *Request) {
|
|
handler := sh.srv.Handler
|
|
if handler == nil {
|
|
handler = DefaultServeMux
|
|
}
|
|
if req.RequestURI == "*" && req.Method == "OPTIONS" {
|
|
handler = globalOptionsHandler{}
|
|
}
|
|
handler.ServeHTTP(rw, req)
|
|
}
|
|
|
|
// ListenAndServe listens on the TCP network address srv.Addr and then
|
|
// calls Serve to handle requests on incoming connections.
|
|
// 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 Shutdown or 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(tcpKeepAliveListener{ln.(*net.TCPListener)})
|
|
}
|
|
|
|
var testHookServerServe func(*Server, net.Listener) // used if non-nil
|
|
|
|
// shouldDoServeHTTP2 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 strSliceContains(srv.TLSConfig.NextProtos, http2NextProtoTLS)
|
|
}
|
|
|
|
// ErrServerClosed is returned by the Server's Serve, ServeTLS, ListenAndServe,
|
|
// and ListenAndServeTLS methods after a call to Shutdown or 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 Shutdown or 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
|
|
}
|
|
|
|
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)
|
|
|
|
var tempDelay time.Duration // how long to sleep on accept failure
|
|
baseCtx := context.Background() // base is always background, per Issue 16220
|
|
ctx := context.WithValue(baseCtx, ServerContextKey, srv)
|
|
for {
|
|
rw, e := l.Accept()
|
|
if e != nil {
|
|
select {
|
|
case <-srv.getDoneChan():
|
|
return ErrServerClosed
|
|
default:
|
|
}
|
|
if ne, ok := e.(net.Error); ok && ne.Temporary() {
|
|
if tempDelay == 0 {
|
|
tempDelay = 5 * time.Millisecond
|
|
} else {
|
|
tempDelay *= 2
|
|
}
|
|
if max := 1 * time.Second; tempDelay > max {
|
|
tempDelay = max
|
|
}
|
|
srv.logf("http: Accept error: %v; retrying in %v", e, tempDelay)
|
|
time.Sleep(tempDelay)
|
|
continue
|
|
}
|
|
return e
|
|
}
|
|
tempDelay = 0
|
|
c := srv.newConn(rw)
|
|
c.setState(c.rwc, StateNew) // before Serve can return
|
|
go c.serve(ctx)
|
|
}
|
|
}
|
|
|
|
// 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 Shutdown or 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 !strSliceContains(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{}{}
|
|
} else {
|
|
delete(s.listeners, ln)
|
|
}
|
|
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 atomic.LoadInt32(&s.disableKeepAlives) == 0 && !s.shuttingDown()
|
|
}
|
|
|
|
func (s *Server) shuttingDown() bool {
|
|
// TODO: replace inShutdown with the existing atomicBool type;
|
|
// see https://github.com/golang/go/issues/20239#issuecomment-381434582
|
|
return atomic.LoadInt32(&s.inShutdown) != 0
|
|
}
|
|
|
|
// SetKeepAlivesEnabled controls whether HTTP keep-alives are enabled.
|
|
// By default, keep-alives are always enabled. Only very
|
|
// resource-constrained environments or servers in the process of
|
|
// shutting down should disable them.
|
|
func (srv *Server) SetKeepAlivesEnabled(v bool) {
|
|
if v {
|
|
atomic.StoreInt32(&srv.disableKeepAlives, 0)
|
|
return
|
|
}
|
|
atomic.StoreInt32(&srv.disableKeepAlives, 1)
|
|
|
|
// 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 ...interface{}) {
|
|
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 ...interface{}) {
|
|
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 the 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 Shutdown or
|
|
// 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(tcpKeepAliveListener{ln.(*net.TCPListener)}, 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()
|
|
}
|
|
}
|
|
|
|
// 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 strings.Contains(os.Getenv("GODEBUG"), "http2server=0") {
|
|
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 buffers all Handler writes to memory and 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),
|
|
}
|
|
panicChan := make(chan interface{}, 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()
|
|
w.WriteHeader(StatusServiceUnavailable)
|
|
io.WriteString(w, h.errorBody())
|
|
tw.timedOut = true
|
|
}
|
|
}
|
|
|
|
type timeoutWriter struct {
|
|
w ResponseWriter
|
|
h Header
|
|
wbuf bytes.Buffer
|
|
|
|
mu sync.Mutex
|
|
timedOut bool
|
|
wroteHeader bool
|
|
code int
|
|
}
|
|
|
|
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.timedOut {
|
|
return 0, ErrHandlerTimeout
|
|
}
|
|
if !tw.wroteHeader {
|
|
tw.writeHeader(StatusOK)
|
|
}
|
|
return tw.wbuf.Write(p)
|
|
}
|
|
|
|
func (tw *timeoutWriter) WriteHeader(code int) {
|
|
checkWriteHeaderCode(code)
|
|
tw.mu.Lock()
|
|
defer tw.mu.Unlock()
|
|
if tw.timedOut || tw.wroteHeader {
|
|
return
|
|
}
|
|
tw.writeHeader(code)
|
|
}
|
|
|
|
func (tw *timeoutWriter) writeHeader(code int) {
|
|
tw.wroteHeader = true
|
|
tw.code = code
|
|
}
|
|
|
|
// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
|
|
// connections. It's used by ListenAndServe and ListenAndServeTLS so
|
|
// dead TCP connections (e.g. closing laptop mid-download) eventually
|
|
// go away.
|
|
type tcpKeepAliveListener struct {
|
|
*net.TCPListener
|
|
}
|
|
|
|
func (ln tcpKeepAliveListener) Accept() (net.Conn, error) {
|
|
tc, err := ln.AcceptTCP()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
tc.SetKeepAlive(true)
|
|
tc.SetKeepAlivePeriod(3 * time.Minute)
|
|
return tc, nil
|
|
}
|
|
|
|
// 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(ioutil.Discard, mb)
|
|
}
|
|
}
|
|
|
|
// initNPNRequest is an HTTP handler that initializes certain
|
|
// uninitialized fields in its *Request. Such partially-initialized
|
|
// Requests come from NPN protocol handlers.
|
|
type initNPNRequest struct {
|
|
c *tls.Conn
|
|
h serverHandler
|
|
}
|
|
|
|
func (h initNPNRequest) ServeHTTP(rw ResponseWriter, req *Request) {
|
|
if req.TLS == nil {
|
|
req.TLS = &tls.ConnectionState{}
|
|
*req.TLS = h.c.ConnectionState()
|
|
}
|
|
if req.Body == nil {
|
|
req.Body = 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
|
|
|
|
}
|
|
|
|
func strSliceContains(ss []string, s string) bool {
|
|
for _, v := range ss {
|
|
if v == s {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// 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
|
|
}
|