mirror of
https://github.com/caddyserver/caddy.git
synced 2024-12-16 21:56:40 -05:00
292 lines
8.2 KiB
Go
292 lines
8.2 KiB
Go
// Copyright 2015 Matthew Holt and The Caddy Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
// Most of the code in this file was initially borrowed from the Go
|
|
// standard library and modified; It had this copyright notice:
|
|
// Copyright 2011 The Go Authors
|
|
|
|
package reverseproxy
|
|
|
|
import (
|
|
"context"
|
|
"io"
|
|
"mime"
|
|
"net/http"
|
|
"sync"
|
|
"time"
|
|
|
|
"go.uber.org/zap"
|
|
)
|
|
|
|
func (h Handler) handleUpgradeResponse(logger *zap.Logger, rw http.ResponseWriter, req *http.Request, res *http.Response) {
|
|
reqUpType := upgradeType(req.Header)
|
|
resUpType := upgradeType(res.Header)
|
|
|
|
// Taken from https://github.com/golang/go/commit/5c489514bc5e61ad9b5b07bd7d8ec65d66a0512a
|
|
// We know reqUpType is ASCII, it's checked by the caller.
|
|
if !asciiIsPrint(resUpType) {
|
|
h.logger.Debug("backend tried to switch to invalid protocol",
|
|
zap.String("backend_upgrade", resUpType))
|
|
return
|
|
}
|
|
if !asciiEqualFold(reqUpType, resUpType) {
|
|
h.logger.Debug("backend tried to switch to unexpected protocol via Upgrade header",
|
|
zap.String("backend_upgrade", resUpType),
|
|
zap.String("requested_upgrade", reqUpType))
|
|
return
|
|
}
|
|
|
|
hj, ok := rw.(http.Hijacker)
|
|
if !ok {
|
|
h.logger.Sugar().Errorf("can't switch protocols using non-Hijacker ResponseWriter type %T", rw)
|
|
return
|
|
}
|
|
backConn, ok := res.Body.(io.ReadWriteCloser)
|
|
if !ok {
|
|
h.logger.Error("internal error: 101 switching protocols response with non-writable body")
|
|
return
|
|
}
|
|
|
|
// adopted from https://github.com/golang/go/commit/8bcf2834afdf6a1f7937390903a41518715ef6f5
|
|
backConnCloseCh := make(chan struct{})
|
|
go func() {
|
|
// Ensure that the cancelation of a request closes the backend.
|
|
// See issue https://golang.org/issue/35559.
|
|
select {
|
|
case <-req.Context().Done():
|
|
case <-backConnCloseCh:
|
|
}
|
|
backConn.Close()
|
|
}()
|
|
defer close(backConnCloseCh)
|
|
|
|
logger.Debug("upgrading connection")
|
|
conn, brw, err := hj.Hijack()
|
|
if err != nil {
|
|
h.logger.Error("hijack failed on protocol switch", zap.Error(err))
|
|
return
|
|
}
|
|
defer conn.Close()
|
|
|
|
start := time.Now()
|
|
defer func() {
|
|
logger.Debug("connection closed", zap.Duration("duration", time.Since(start)))
|
|
}()
|
|
|
|
copyHeader(rw.Header(), res.Header)
|
|
|
|
res.Header = rw.Header()
|
|
res.Body = nil // so res.Write only writes the headers; we have res.Body in backConn above
|
|
if err := res.Write(brw); err != nil {
|
|
h.logger.Debug("response write", zap.Error(err))
|
|
return
|
|
}
|
|
if err := brw.Flush(); err != nil {
|
|
h.logger.Debug("response flush", zap.Error(err))
|
|
return
|
|
}
|
|
|
|
errc := make(chan error, 1)
|
|
spc := switchProtocolCopier{user: conn, backend: backConn}
|
|
go spc.copyToBackend(errc)
|
|
go spc.copyFromBackend(errc)
|
|
<-errc
|
|
}
|
|
|
|
// flushInterval returns the p.FlushInterval value, conditionally
|
|
// overriding its value for a specific request/response.
|
|
func (h Handler) flushInterval(req *http.Request, res *http.Response) time.Duration {
|
|
resCTHeader := res.Header.Get("Content-Type")
|
|
resCT, _, err := mime.ParseMediaType(resCTHeader)
|
|
|
|
// For Server-Sent Events responses, flush immediately.
|
|
// The MIME type is defined in https://www.w3.org/TR/eventsource/#text-event-stream
|
|
if err == nil && resCT == "text/event-stream" {
|
|
return -1 // negative means immediately
|
|
}
|
|
|
|
// We might have the case of streaming for which Content-Length might be unset.
|
|
if res.ContentLength == -1 {
|
|
return -1
|
|
}
|
|
|
|
// for h2 and h2c upstream streaming data to client (issues #3556 and #3606)
|
|
if h.isBidirectionalStream(req, res) {
|
|
return -1
|
|
}
|
|
|
|
return time.Duration(h.FlushInterval)
|
|
}
|
|
|
|
// isBidirectionalStream returns whether we should work in bi-directional stream mode.
|
|
//
|
|
// See https://github.com/caddyserver/caddy/pull/3620 for discussion of nuances.
|
|
func (h Handler) isBidirectionalStream(req *http.Request, res *http.Response) bool {
|
|
// We have to check the encoding here; only flush headers with identity encoding.
|
|
// Non-identity encoding might combine with "encode" directive, and in that case,
|
|
// if body size larger than enc.MinLength, upper level encode handle might have
|
|
// Content-Encoding header to write.
|
|
// (see https://github.com/caddyserver/caddy/issues/3606 for use case)
|
|
ae := req.Header.Get("Accept-Encoding")
|
|
|
|
return req.ProtoMajor == 2 &&
|
|
res.ProtoMajor == 2 &&
|
|
res.ContentLength == -1 &&
|
|
(ae == "identity" || ae == "")
|
|
}
|
|
|
|
func (h Handler) copyResponse(dst io.Writer, src io.Reader, flushInterval time.Duration) error {
|
|
if flushInterval != 0 {
|
|
if wf, ok := dst.(writeFlusher); ok {
|
|
mlw := &maxLatencyWriter{
|
|
dst: wf,
|
|
latency: flushInterval,
|
|
}
|
|
defer mlw.stop()
|
|
|
|
// set up initial timer so headers get flushed even if body writes are delayed
|
|
mlw.flushPending = true
|
|
mlw.t = time.AfterFunc(flushInterval, mlw.delayedFlush)
|
|
|
|
dst = mlw
|
|
}
|
|
}
|
|
|
|
buf := streamingBufPool.Get().(*[]byte)
|
|
defer streamingBufPool.Put(buf)
|
|
_, err := h.copyBuffer(dst, src, *buf)
|
|
return err
|
|
}
|
|
|
|
// copyBuffer returns any write errors or non-EOF read errors, and the amount
|
|
// of bytes written.
|
|
func (h Handler) copyBuffer(dst io.Writer, src io.Reader, buf []byte) (int64, error) {
|
|
if len(buf) == 0 {
|
|
buf = make([]byte, defaultBufferSize)
|
|
}
|
|
var written int64
|
|
for {
|
|
nr, rerr := src.Read(buf)
|
|
if rerr != nil && rerr != io.EOF && rerr != context.Canceled {
|
|
// TODO: this could be useful to know (indeed, it revealed an error in our
|
|
// fastcgi PoC earlier; but it's this single error report here that necessitates
|
|
// a function separate from io.CopyBuffer, since io.CopyBuffer does not distinguish
|
|
// between read or write errors; in a reverse proxy situation, write errors are not
|
|
// something we need to report to the client, but read errors are a problem on our
|
|
// end for sure. so we need to decide what we want.)
|
|
// p.logf("copyBuffer: ReverseProxy read error during body copy: %v", rerr)
|
|
h.logger.Error("reading from backend", zap.Error(rerr))
|
|
}
|
|
if nr > 0 {
|
|
nw, werr := dst.Write(buf[:nr])
|
|
if nw > 0 {
|
|
written += int64(nw)
|
|
}
|
|
if werr != nil {
|
|
return written, werr
|
|
}
|
|
if nr != nw {
|
|
return written, io.ErrShortWrite
|
|
}
|
|
}
|
|
if rerr != nil {
|
|
if rerr == io.EOF {
|
|
rerr = nil
|
|
}
|
|
return written, rerr
|
|
}
|
|
}
|
|
}
|
|
|
|
type writeFlusher interface {
|
|
io.Writer
|
|
http.Flusher
|
|
}
|
|
|
|
type maxLatencyWriter struct {
|
|
dst writeFlusher
|
|
latency time.Duration // non-zero; negative means to flush immediately
|
|
|
|
mu sync.Mutex // protects t, flushPending, and dst.Flush
|
|
t *time.Timer
|
|
flushPending bool
|
|
}
|
|
|
|
func (m *maxLatencyWriter) Write(p []byte) (n int, err error) {
|
|
m.mu.Lock()
|
|
defer m.mu.Unlock()
|
|
n, err = m.dst.Write(p)
|
|
if m.latency < 0 {
|
|
m.dst.Flush()
|
|
return
|
|
}
|
|
if m.flushPending {
|
|
return
|
|
}
|
|
if m.t == nil {
|
|
m.t = time.AfterFunc(m.latency, m.delayedFlush)
|
|
} else {
|
|
m.t.Reset(m.latency)
|
|
}
|
|
m.flushPending = true
|
|
return
|
|
}
|
|
|
|
func (m *maxLatencyWriter) delayedFlush() {
|
|
m.mu.Lock()
|
|
defer m.mu.Unlock()
|
|
if !m.flushPending { // if stop was called but AfterFunc already started this goroutine
|
|
return
|
|
}
|
|
m.dst.Flush()
|
|
m.flushPending = false
|
|
}
|
|
|
|
func (m *maxLatencyWriter) stop() {
|
|
m.mu.Lock()
|
|
defer m.mu.Unlock()
|
|
m.flushPending = false
|
|
if m.t != nil {
|
|
m.t.Stop()
|
|
}
|
|
}
|
|
|
|
// switchProtocolCopier exists so goroutines proxying data back and
|
|
// forth have nice names in stacks.
|
|
type switchProtocolCopier struct {
|
|
user, backend io.ReadWriter
|
|
}
|
|
|
|
func (c switchProtocolCopier) copyFromBackend(errc chan<- error) {
|
|
_, err := io.Copy(c.user, c.backend)
|
|
errc <- err
|
|
}
|
|
|
|
func (c switchProtocolCopier) copyToBackend(errc chan<- error) {
|
|
_, err := io.Copy(c.backend, c.user)
|
|
errc <- err
|
|
}
|
|
|
|
var streamingBufPool = sync.Pool{
|
|
New: func() any {
|
|
// The Pool's New function should generally only return pointer
|
|
// types, since a pointer can be put into the return interface
|
|
// value without an allocation
|
|
// - (from the package docs)
|
|
b := make([]byte, defaultBufferSize)
|
|
return &b
|
|
},
|
|
}
|
|
|
|
const defaultBufferSize = 32 * 1024
|