add ip filter for httpreverseproxy
parent
1d478bef0a
commit
9fc353211f
@ -0,0 +1,852 @@
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// Copyright 2011 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 reverse proxy handler
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package rp
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import (
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"context"
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"errors"
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"fmt"
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"io"
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"log"
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"mime"
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"net"
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"net/http"
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"net/http/httptrace"
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"net/textproto"
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"net/url"
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"strings"
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"sync"
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"time"
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"golang.org/x/net/http/httpguts"
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)
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func lower(b byte) byte {
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if 'A' <= b && b <= 'Z' {
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return b + ('a' - 'A')
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}
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return b
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}
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func EqualFold(s, t string) bool {
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if len(s) != len(t) {
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return false
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}
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for i := 0; i < len(s); i++ {
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if lower(s[i]) != lower(t[i]) {
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return false
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}
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}
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return true
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}
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func IsPrint(s string) bool {
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for i := 0; i < len(s); i++ {
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if s[i] < ' ' || s[i] > '~' {
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return false
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}
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}
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return true
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}
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// A ProxyRequest contains a request to be rewritten by a ReverseProxy.
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type ProxyRequest struct {
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// In is the request received by the proxy.
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// The Rewrite function must not modify In.
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In *http.Request
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// Out is the request which will be sent by the proxy.
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// The Rewrite function may modify or replace this request.
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// Hop-by-hop headers are removed from this request
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// before Rewrite is called.
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Out *http.Request
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}
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// SetURL routes the outbound request to the scheme, host, and base path
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// provided in target. If the target's path is "/base" and the incoming
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// request was for "/dir", the target request will be for "/base/dir".
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//
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// SetURL rewrites the outbound Host header to match the target's host.
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// To preserve the inbound request's Host header (the default behavior
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// of NewSingleHostReverseProxy):
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//
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// rewriteFunc := func(r *httputil.ProxyRequest) {
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// r.SetURL(url)
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// r.Out.Host = r.In.Host
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// }
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func (r *ProxyRequest) SetURL(target *url.URL) {
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rewriteRequestURL(r.Out, target)
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r.Out.Host = ""
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}
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// SetXForwarded sets the X-Forwarded-For, X-Forwarded-Host, and
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// X-Forwarded-Proto headers of the outbound request.
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//
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// - The X-Forwarded-For header is set to the client IP address.
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// - The X-Forwarded-Host header is set to the host name requested
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// by the client.
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// - The X-Forwarded-Proto header is set to "http" or "https", depending
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// on whether the inbound request was made on a TLS-enabled connection.
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//
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// If the outbound request contains an existing X-Forwarded-For header,
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// SetXForwarded appends the client IP address to it. To append to the
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// inbound request's X-Forwarded-For header (the default behavior of
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// ReverseProxy when using a Director function), copy the header
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// from the inbound request before calling SetXForwarded:
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//
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// rewriteFunc := func(r *httputil.ProxyRequest) {
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// r.Out.Header["X-Forwarded-For"] = r.In.Header["X-Forwarded-For"]
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// r.SetXForwarded()
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// }
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func (r *ProxyRequest) SetXForwarded() {
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clientIP, _, err := net.SplitHostPort(r.In.RemoteAddr)
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if err == nil {
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prior := r.Out.Header["X-Forwarded-For"]
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if len(prior) > 0 {
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clientIP = strings.Join(prior, ", ") + ", " + clientIP
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}
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r.Out.Header.Set("X-Forwarded-For", clientIP)
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} else {
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r.Out.Header.Del("X-Forwarded-For")
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}
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r.Out.Header.Set("X-Forwarded-Host", r.In.Host)
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if r.In.TLS == nil {
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r.Out.Header.Set("X-Forwarded-Proto", "http")
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} else {
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r.Out.Header.Set("X-Forwarded-Proto", "https")
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}
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}
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// ReverseProxy is an HTTP Handler that takes an incoming request and
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// sends it to another server, proxying the response back to the
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// client.
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//
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// 1xx responses are forwarded to the client if the underlying
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// transport supports ClientTrace.Got1xxResponse.
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type ReverseProxy struct {
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// Rewrite must be a function which modifies
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// the request into a new request to be sent
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// using Transport. Its response is then copied
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// back to the original client unmodified.
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// Rewrite must not access the provided ProxyRequest
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// or its contents after returning.
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//
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// The Forwarded, X-Forwarded, X-Forwarded-Host,
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// and X-Forwarded-Proto headers are removed from the
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// outbound request before Rewrite is called. See also
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// the ProxyRequest.SetXForwarded method.
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//
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// Unparsable query parameters are removed from the
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// outbound request before Rewrite is called.
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// The Rewrite function may copy the inbound URL's
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// RawQuery to the outbound URL to preserve the original
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// parameter string. Note that this can lead to security
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// issues if the proxy's interpretation of query parameters
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// does not match that of the downstream server.
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//
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// At most one of Rewrite or Director may be set.
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Rewrite func(*ProxyRequest)
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// Director is a function which modifies
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// the request into a new request to be sent
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// using Transport. Its response is then copied
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// back to the original client unmodified.
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// Director must not access the provided Request
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// after returning.
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//
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// By default, the X-Forwarded-For header is set to the
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// value of the client IP address. If an X-Forwarded-For
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// header already exists, the client IP is appended to the
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// existing values. As a special case, if the header
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// exists in the Request.Header map but has a nil value
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// (such as when set by the Director func), the X-Forwarded-For
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// header is not modified.
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//
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// To prevent IP spoofing, be sure to delete any pre-existing
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// X-Forwarded-For header coming from the client or
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// an untrusted proxy.
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//
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// Hop-by-hop headers are removed from the request after
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// Director returns, which can remove headers added by
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// Director. Use a Rewrite function instead to ensure
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// modifications to the request are preserved.
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//
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// Unparsable query parameters are removed from the outbound
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// request if Request.Form is set after Director returns.
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//
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// At most one of Rewrite or Director may be set.
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Director func(*http.Request)
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// The transport used to perform proxy requests.
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// If nil, http.DefaultTransport is used.
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Transport http.RoundTripper
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// FlushInterval specifies the flush interval
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// to flush to the client while copying the
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// response body.
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// If zero, no periodic flushing is done.
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// A negative value means to flush immediately
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// after each write to the client.
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// The FlushInterval is ignored when ReverseProxy
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// recognizes a response as a streaming response, or
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// if its ContentLength is -1; for such responses, writes
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// are flushed to the client immediately.
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FlushInterval time.Duration
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// ErrorLog specifies an optional logger for errors
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// that occur when attempting to proxy the request.
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// If nil, logging is done via the log package's standard logger.
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ErrorLog *log.Logger
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// BufferPool optionally specifies a buffer pool to
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// get byte slices for use by io.CopyBuffer when
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// copying HTTP response bodies.
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BufferPool BufferPool
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// ModifyResponse is an optional function that modifies the
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// Response from the backend. It is called if the backend
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// returns a response at all, with any HTTP status code.
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// If the backend is unreachable, the optional ErrorHandler is
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// called without any call to ModifyResponse.
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//
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// If ModifyResponse returns an error, ErrorHandler is called
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// with its error value. If ErrorHandler is nil, its default
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// implementation is used.
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ModifyResponse func(*http.Response) error
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// ErrorHandler is an optional function that handles errors
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// reaching the backend or errors from ModifyResponse.
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//
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// If nil, the default is to log the provided error and return
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// a 502 Status Bad Gateway response.
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ErrorHandler func(http.ResponseWriter, *http.Request, error)
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}
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// A BufferPool is an interface for getting and returning temporary
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// byte slices for use by io.CopyBuffer.
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type BufferPool interface {
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Get() []byte
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Put([]byte)
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}
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func singleJoiningSlash(a, b string) string {
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aslash := strings.HasSuffix(a, "/")
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bslash := strings.HasPrefix(b, "/")
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switch {
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case aslash && bslash:
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return a + b[1:]
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case !aslash && !bslash:
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return a + "/" + b
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}
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return a + b
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}
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func joinURLPath(a, b *url.URL) (path, rawpath string) {
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if a.RawPath == "" && b.RawPath == "" {
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return singleJoiningSlash(a.Path, b.Path), ""
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}
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// Same as singleJoiningSlash, but uses EscapedPath to determine
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// whether a slash should be added
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apath := a.EscapedPath()
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bpath := b.EscapedPath()
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aslash := strings.HasSuffix(apath, "/")
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bslash := strings.HasPrefix(bpath, "/")
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switch {
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case aslash && bslash:
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return a.Path + b.Path[1:], apath + bpath[1:]
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case !aslash && !bslash:
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return a.Path + "/" + b.Path, apath + "/" + bpath
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}
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return a.Path + b.Path, apath + bpath
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}
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// NewSingleHostReverseProxy returns a new ReverseProxy that routes
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// URLs to the scheme, host, and base path provided in target. If the
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// target's path is "/base" and the incoming request was for "/dir",
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// the target request will be for /base/dir.
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//
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// NewSingleHostReverseProxy does not rewrite the Host header.
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//
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// To customize the ReverseProxy behavior beyond what
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// NewSingleHostReverseProxy provides, use ReverseProxy directly
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// with a Rewrite function. The ProxyRequest SetURL method
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// may be used to route the outbound request. (Note that SetURL,
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// unlike NewSingleHostReverseProxy, rewrites the Host header
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// of the outbound request by default.)
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//
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// proxy := &ReverseProxy{
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// Rewrite: func(r *ProxyRequest) {
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// r.SetURL(target)
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// r.Out.Host = r.In.Host // if desired
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// }
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// }
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func NewSingleHostReverseProxy(target *url.URL) *ReverseProxy {
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director := func(req *http.Request) {
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rewriteRequestURL(req, target)
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}
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return &ReverseProxy{Director: director}
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}
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func rewriteRequestURL(req *http.Request, target *url.URL) {
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targetQuery := target.RawQuery
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req.URL.Scheme = target.Scheme
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req.URL.Host = target.Host
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req.URL.Path, req.URL.RawPath = joinURLPath(target, req.URL)
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if targetQuery == "" || req.URL.RawQuery == "" {
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req.URL.RawQuery = targetQuery + req.URL.RawQuery
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} else {
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req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
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}
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}
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func copyHeader(dst, src http.Header) {
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for k, vv := range src {
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for _, v := range vv {
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dst.Add(k, v)
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}
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}
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}
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// Hop-by-hop headers. These are removed when sent to the backend.
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// As of RFC 7230, hop-by-hop headers are required to appear in the
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// Connection header field. These are the headers defined by the
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// obsoleted RFC 2616 (section 13.5.1) and are used for backward
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// compatibility.
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var hopHeaders = []string{
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"Connection",
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"Proxy-Connection", // non-standard but still sent by libcurl and rejected by e.g. google
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"Keep-Alive",
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"Proxy-Authenticate",
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"Proxy-Authorization",
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"Te", // canonicalized version of "TE"
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"Trailer", // not Trailers per URL above; https://www.rfc-editor.org/errata_search.php?eid=4522
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"Transfer-Encoding",
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"Upgrade",
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}
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func (p *ReverseProxy) defaultErrorHandler(rw http.ResponseWriter, req *http.Request, err error) {
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p.logf("http: proxy error: %v", err)
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rw.WriteHeader(http.StatusBadGateway)
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}
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func (p *ReverseProxy) getErrorHandler() func(http.ResponseWriter, *http.Request, error) {
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if p.ErrorHandler != nil {
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return p.ErrorHandler
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}
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return p.defaultErrorHandler
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}
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// modifyResponse conditionally runs the optional ModifyResponse hook
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// and reports whether the request should proceed.
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func (p *ReverseProxy) modifyResponse(rw http.ResponseWriter, res *http.Response, req *http.Request) bool {
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if p.ModifyResponse == nil {
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return true
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}
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if err := p.ModifyResponse(res); err != nil {
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res.Body.Close()
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p.getErrorHandler()(rw, req, err)
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return false
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}
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return true
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}
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func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
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transport := p.Transport
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if transport == nil {
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transport = http.DefaultTransport
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}
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ctx := req.Context()
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if ctx.Done() != nil {
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// CloseNotifier predates context.Context, and has been
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// entirely superseded by it. If the request contains
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// a Context that carries a cancellation signal, don't
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// bother spinning up a goroutine to watch the CloseNotify
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// channel (if any).
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//
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// If the request Context has a nil Done channel (which
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// means it is either context.Background, or a custom
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// Context implementation with no cancellation signal),
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// then consult the CloseNotifier if available.
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} else if cn, ok := rw.(http.CloseNotifier); ok {
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var cancel context.CancelFunc
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ctx, cancel = context.WithCancel(ctx)
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defer cancel()
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notifyChan := cn.CloseNotify()
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go func() {
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select {
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case <-notifyChan:
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cancel()
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case <-ctx.Done():
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||||||
|
}
|
||||||
|
}()
|
||||||
|
}
|
||||||
|
|
||||||
|
outreq := req.Clone(ctx)
|
||||||
|
if req.ContentLength == 0 {
|
||||||
|
outreq.Body = nil // Issue 16036: nil Body for http.Transport retries
|
||||||
|
}
|
||||||
|
if outreq.Body != nil {
|
||||||
|
// Reading from the request body after returning from a handler is not
|
||||||
|
// allowed, and the RoundTrip goroutine that reads the Body can outlive
|
||||||
|
// this handler. This can lead to a crash if the handler panics (see
|
||||||
|
// Issue 46866). Although calling Close doesn't guarantee there isn't
|
||||||
|
// any Read in flight after the handle returns, in practice it's safe to
|
||||||
|
// read after closing it.
|
||||||
|
defer outreq.Body.Close()
|
||||||
|
}
|
||||||
|
if outreq.Header == nil {
|
||||||
|
outreq.Header = make(http.Header) // Issue 33142: historical behavior was to always allocate
|
||||||
|
}
|
||||||
|
|
||||||
|
if (p.Director != nil) == (p.Rewrite != nil) {
|
||||||
|
p.getErrorHandler()(rw, req, errors.New("ReverseProxy must have exactly one of Director or Rewrite set"))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
if p.Director != nil {
|
||||||
|
p.Director(outreq)
|
||||||
|
if outreq.Form != nil {
|
||||||
|
outreq.URL.RawQuery = cleanQueryParams(outreq.URL.RawQuery)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
outreq.Close = false
|
||||||
|
|
||||||
|
reqUpType := upgradeType(outreq.Header)
|
||||||
|
if !IsPrint(reqUpType) {
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("client tried to switch to invalid protocol %q", reqUpType))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
removeHopByHopHeaders(outreq.Header)
|
||||||
|
|
||||||
|
// Issue 21096: tell backend applications that care about trailer support
|
||||||
|
// that we support trailers. (We do, but we don't go out of our way to
|
||||||
|
// advertise that unless the incoming client request thought it was worth
|
||||||
|
// mentioning.) Note that we look at req.Header, not outreq.Header, since
|
||||||
|
// the latter has passed through removeHopByHopHeaders.
|
||||||
|
if httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") {
|
||||||
|
outreq.Header.Set("Te", "trailers")
|
||||||
|
}
|
||||||
|
|
||||||
|
// After stripping all the hop-by-hop connection headers above, add back any
|
||||||
|
// necessary for protocol upgrades, such as for websockets.
|
||||||
|
if reqUpType != "" {
|
||||||
|
outreq.Header.Set("Connection", "Upgrade")
|
||||||
|
outreq.Header.Set("Upgrade", reqUpType)
|
||||||
|
}
|
||||||
|
|
||||||
|
if p.Rewrite != nil {
|
||||||
|
// Strip client-provided forwarding headers.
|
||||||
|
// The Rewrite func may use SetXForwarded to set new values
|
||||||
|
// for these or copy the previous values from the inbound request.
|
||||||
|
outreq.Header.Del("Forwarded")
|
||||||
|
outreq.Header.Del("X-Forwarded-For")
|
||||||
|
outreq.Header.Del("X-Forwarded-Host")
|
||||||
|
outreq.Header.Del("X-Forwarded-Proto")
|
||||||
|
|
||||||
|
// Remove unparsable query parameters from the outbound request.
|
||||||
|
outreq.URL.RawQuery = cleanQueryParams(outreq.URL.RawQuery)
|
||||||
|
|
||||||
|
pr := &ProxyRequest{
|
||||||
|
In: req,
|
||||||
|
Out: outreq,
|
||||||
|
}
|
||||||
|
p.Rewrite(pr)
|
||||||
|
outreq = pr.Out
|
||||||
|
}
|
||||||
|
|
||||||
|
if _, ok := outreq.Header["User-Agent"]; !ok {
|
||||||
|
// If the outbound request doesn't have a User-Agent header set,
|
||||||
|
// don't send the default Go HTTP client User-Agent.
|
||||||
|
outreq.Header.Set("User-Agent", "")
|
||||||
|
}
|
||||||
|
|
||||||
|
trace := &httptrace.ClientTrace{
|
||||||
|
Got1xxResponse: func(code int, header textproto.MIMEHeader) error {
|
||||||
|
h := rw.Header()
|
||||||
|
copyHeader(h, http.Header(header))
|
||||||
|
rw.WriteHeader(code)
|
||||||
|
|
||||||
|
// Clear headers, it's not automatically done by ResponseWriter.WriteHeader() for 1xx responses
|
||||||
|
for k := range h {
|
||||||
|
delete(h, k)
|
||||||
|
}
|
||||||
|
|
||||||
|
return nil
|
||||||
|
},
|
||||||
|
}
|
||||||
|
outreq = outreq.WithContext(httptrace.WithClientTrace(outreq.Context(), trace))
|
||||||
|
|
||||||
|
res, err := transport.RoundTrip(outreq)
|
||||||
|
if err != nil {
|
||||||
|
p.getErrorHandler()(rw, outreq, err)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
// Deal with 101 Switching Protocols responses: (WebSocket, h2c, etc)
|
||||||
|
if res.StatusCode == http.StatusSwitchingProtocols {
|
||||||
|
if !p.modifyResponse(rw, res, outreq) {
|
||||||
|
return
|
||||||
|
}
|
||||||
|
p.handleUpgradeResponse(rw, outreq, res)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
removeHopByHopHeaders(res.Header)
|
||||||
|
|
||||||
|
if !p.modifyResponse(rw, res, outreq) {
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
copyHeader(rw.Header(), res.Header)
|
||||||
|
|
||||||
|
// The "Trailer" header isn't included in the Transport's response,
|
||||||
|
// at least for *http.Transport. Build it up from Trailer.
|
||||||
|
announcedTrailers := len(res.Trailer)
|
||||||
|
if announcedTrailers > 0 {
|
||||||
|
trailerKeys := make([]string, 0, len(res.Trailer))
|
||||||
|
for k := range res.Trailer {
|
||||||
|
trailerKeys = append(trailerKeys, k)
|
||||||
|
}
|
||||||
|
rw.Header().Add("Trailer", strings.Join(trailerKeys, ", "))
|
||||||
|
}
|
||||||
|
|
||||||
|
rw.WriteHeader(res.StatusCode)
|
||||||
|
|
||||||
|
err = p.copyResponse(rw, res.Body, p.flushInterval(res))
|
||||||
|
if err != nil {
|
||||||
|
defer res.Body.Close()
|
||||||
|
// Since we're streaming the response, if we run into an error all we can do
|
||||||
|
// is abort the request. Issue 23643: ReverseProxy should use ErrAbortHandler
|
||||||
|
// on read error while copying body.
|
||||||
|
if !shouldPanicOnCopyError(req) {
|
||||||
|
p.logf("suppressing panic for copyResponse error in test; copy error: %v", err)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
panic(http.ErrAbortHandler)
|
||||||
|
}
|
||||||
|
res.Body.Close() // close now, instead of defer, to populate res.Trailer
|
||||||
|
|
||||||
|
if len(res.Trailer) > 0 {
|
||||||
|
// Force chunking if we saw a response trailer.
|
||||||
|
// This prevents net/http from calculating the length for short
|
||||||
|
// bodies and adding a Content-Length.
|
||||||
|
if fl, ok := rw.(http.Flusher); ok {
|
||||||
|
fl.Flush()
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
if len(res.Trailer) == announcedTrailers {
|
||||||
|
copyHeader(rw.Header(), res.Trailer)
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
for k, vv := range res.Trailer {
|
||||||
|
k = http.TrailerPrefix + k
|
||||||
|
for _, v := range vv {
|
||||||
|
rw.Header().Add(k, v)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
var inOurTests bool // whether we're in our own tests
|
||||||
|
|
||||||
|
// shouldPanicOnCopyError reports whether the reverse proxy should
|
||||||
|
// panic with http.ErrAbortHandler. This is the right thing to do by
|
||||||
|
// default, but Go 1.10 and earlier did not, so existing unit tests
|
||||||
|
// weren't expecting panics. Only panic in our own tests, or when
|
||||||
|
// running under the HTTP server.
|
||||||
|
func shouldPanicOnCopyError(req *http.Request) bool {
|
||||||
|
if inOurTests {
|
||||||
|
// Our tests know to handle this panic.
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
if req.Context().Value(http.ServerContextKey) != nil {
|
||||||
|
// We seem to be running under an HTTP server, so
|
||||||
|
// it'll recover the panic.
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
// Otherwise act like Go 1.10 and earlier to not break
|
||||||
|
// existing tests.
|
||||||
|
return false
|
||||||
|
}
|
||||||
|
|
||||||
|
// removeHopByHopHeaders removes hop-by-hop headers.
|
||||||
|
func removeHopByHopHeaders(h http.Header) {
|
||||||
|
// RFC 7230, section 6.1: Remove headers listed in the "Connection" header.
|
||||||
|
for _, f := range h["Connection"] {
|
||||||
|
for _, sf := range strings.Split(f, ",") {
|
||||||
|
if sf = textproto.TrimString(sf); sf != "" {
|
||||||
|
h.Del(sf)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
// RFC 2616, section 13.5.1: Remove a set of known hop-by-hop headers.
|
||||||
|
// This behavior is superseded by the RFC 7230 Connection header, but
|
||||||
|
// preserve it for backwards compatibility.
|
||||||
|
for _, f := range hopHeaders {
|
||||||
|
h.Del(f)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// flushInterval returns the p.FlushInterval value, conditionally
|
||||||
|
// overriding its value for a specific request/response.
|
||||||
|
func (p *ReverseProxy) flushInterval(res *http.Response) time.Duration {
|
||||||
|
resCT := res.Header.Get("Content-Type")
|
||||||
|
|
||||||
|
// For Server-Sent Events responses, flush immediately.
|
||||||
|
// The MIME type is defined in https://www.w3.org/TR/eventsource/#text-event-stream
|
||||||
|
if baseCT, _, _ := mime.ParseMediaType(resCT); baseCT == "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
|
||||||
|
}
|
||||||
|
|
||||||
|
return p.FlushInterval
|
||||||
|
}
|
||||||
|
|
||||||
|
func (p *ReverseProxy) 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
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
var buf []byte
|
||||||
|
if p.BufferPool != nil {
|
||||||
|
buf = p.BufferPool.Get()
|
||||||
|
defer p.BufferPool.Put(buf)
|
||||||
|
}
|
||||||
|
_, err := p.copyBuffer(dst, src, buf)
|
||||||
|
return err
|
||||||
|
}
|
||||||
|
|
||||||
|
// copyBuffer returns any write errors or non-EOF read errors, and the amount
|
||||||
|
// of bytes written.
|
||||||
|
func (p *ReverseProxy) copyBuffer(dst io.Writer, src io.Reader, buf []byte) (int64, error) {
|
||||||
|
if len(buf) == 0 {
|
||||||
|
buf = make([]byte, 32*1024)
|
||||||
|
}
|
||||||
|
var written int64
|
||||||
|
for {
|
||||||
|
nr, rerr := src.Read(buf)
|
||||||
|
if rerr != nil && rerr != io.EOF && rerr != context.Canceled {
|
||||||
|
p.logf("httputil: ReverseProxy read error during body copy: %v", 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
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func (p *ReverseProxy) logf(format string, args ...any) {
|
||||||
|
if p.ErrorLog != nil {
|
||||||
|
p.ErrorLog.Printf(format, args...)
|
||||||
|
} else {
|
||||||
|
log.Printf(format, args...)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
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()
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func upgradeType(h http.Header) string {
|
||||||
|
if !httpguts.HeaderValuesContainsToken(h["Connection"], "Upgrade") {
|
||||||
|
return ""
|
||||||
|
}
|
||||||
|
return h.Get("Upgrade")
|
||||||
|
}
|
||||||
|
|
||||||
|
func (p *ReverseProxy) handleUpgradeResponse(rw http.ResponseWriter, req *http.Request, res *http.Response) {
|
||||||
|
reqUpType := upgradeType(req.Header)
|
||||||
|
resUpType := upgradeType(res.Header)
|
||||||
|
if !IsPrint(resUpType) { // We know reqUpType is ASCII, it's checked by the caller.
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch to invalid protocol %q", resUpType))
|
||||||
|
}
|
||||||
|
if !EqualFold(reqUpType, resUpType) {
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch protocol %q when %q was requested", resUpType, reqUpType))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
hj, ok := rw.(http.Hijacker)
|
||||||
|
if !ok {
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("can't switch protocols using non-Hijacker ResponseWriter type %T", rw))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
backConn, ok := res.Body.(io.ReadWriteCloser)
|
||||||
|
if !ok {
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("internal error: 101 switching protocols response with non-writable body"))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
backConnCloseCh := make(chan bool)
|
||||||
|
go func() {
|
||||||
|
// Ensure that the cancellation 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)
|
||||||
|
|
||||||
|
conn, brw, err := hj.Hijack()
|
||||||
|
if err != nil {
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("Hijack failed on protocol switch: %v", err))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
defer conn.Close()
|
||||||
|
|
||||||
|
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 {
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("response write: %v", err))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
if err := brw.Flush(); err != nil {
|
||||||
|
p.getErrorHandler()(rw, req, fmt.Errorf("response flush: %v", err))
|
||||||
|
return
|
||||||
|
}
|
||||||
|
errc := make(chan error, 1)
|
||||||
|
spc := switchProtocolCopier{user: conn, backend: backConn}
|
||||||
|
go spc.copyToBackend(errc)
|
||||||
|
go spc.copyFromBackend(errc)
|
||||||
|
<-errc
|
||||||
|
}
|
||||||
|
|
||||||
|
// 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
|
||||||
|
}
|
||||||
|
|
||||||
|
func cleanQueryParams(s string) string {
|
||||||
|
reencode := func(s string) string {
|
||||||
|
v, _ := url.ParseQuery(s)
|
||||||
|
return v.Encode()
|
||||||
|
}
|
||||||
|
for i := 0; i < len(s); {
|
||||||
|
switch s[i] {
|
||||||
|
case ';':
|
||||||
|
return reencode(s)
|
||||||
|
case '%':
|
||||||
|
if i+2 >= len(s) || !ishex(s[i+1]) || !ishex(s[i+2]) {
|
||||||
|
return reencode(s)
|
||||||
|
}
|
||||||
|
i += 3
|
||||||
|
default:
|
||||||
|
i++
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return s
|
||||||
|
}
|
||||||
|
|
||||||
|
func ishex(c byte) bool {
|
||||||
|
switch {
|
||||||
|
case '0' <= c && c <= '9':
|
||||||
|
return true
|
||||||
|
case 'a' <= c && c <= 'f':
|
||||||
|
return true
|
||||||
|
case 'A' <= c && c <= 'F':
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
return false
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue