146 lines
4.3 KiB
Go
146 lines
4.3 KiB
Go
/*
|
|
*
|
|
* Copyright 2017, Google Inc.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met:
|
|
*
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above
|
|
* copyright notice, this list of conditions and the following disclaimer
|
|
* in the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* * Neither the name of Google Inc. nor the names of its
|
|
* contributors may be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
*/
|
|
|
|
package grpc
|
|
|
|
import (
|
|
"bufio"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"net"
|
|
"net/http"
|
|
"net/http/httputil"
|
|
"net/url"
|
|
|
|
"golang.org/x/net/context"
|
|
)
|
|
|
|
var (
|
|
// errDisabled indicates that proxy is disabled for the address.
|
|
errDisabled = errors.New("proxy is disabled for the address")
|
|
// The following variable will be overwritten in the tests.
|
|
httpProxyFromEnvironment = http.ProxyFromEnvironment
|
|
)
|
|
|
|
func mapAddress(ctx context.Context, address string) (string, error) {
|
|
req := &http.Request{
|
|
URL: &url.URL{
|
|
Scheme: "https",
|
|
Host: address,
|
|
},
|
|
}
|
|
url, err := httpProxyFromEnvironment(req)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
if url == nil {
|
|
return "", errDisabled
|
|
}
|
|
return url.Host, nil
|
|
}
|
|
|
|
// To read a response from a net.Conn, http.ReadResponse() takes a bufio.Reader.
|
|
// It's possible that this reader reads more than what's need for the response and stores
|
|
// those bytes in the buffer.
|
|
// bufConn wraps the original net.Conn and the bufio.Reader to make sure we don't lose the
|
|
// bytes in the buffer.
|
|
type bufConn struct {
|
|
net.Conn
|
|
r io.Reader
|
|
}
|
|
|
|
func (c *bufConn) Read(b []byte) (int, error) {
|
|
return c.r.Read(b)
|
|
}
|
|
|
|
func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, addr string) (_ net.Conn, err error) {
|
|
defer func() {
|
|
if err != nil {
|
|
conn.Close()
|
|
}
|
|
}()
|
|
|
|
req := (&http.Request{
|
|
Method: http.MethodConnect,
|
|
URL: &url.URL{Host: addr},
|
|
Header: map[string][]string{"User-Agent": {grpcUA}},
|
|
})
|
|
|
|
if err := sendHTTPRequest(ctx, req, conn); err != nil {
|
|
return nil, fmt.Errorf("failed to write the HTTP request: %v", err)
|
|
}
|
|
|
|
r := bufio.NewReader(conn)
|
|
resp, err := http.ReadResponse(r, req)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("reading server HTTP response: %v", err)
|
|
}
|
|
defer resp.Body.Close()
|
|
if resp.StatusCode != http.StatusOK {
|
|
dump, err := httputil.DumpResponse(resp, true)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to do connect handshake, status code: %s", resp.Status)
|
|
}
|
|
return nil, fmt.Errorf("failed to do connect handshake, response: %q", dump)
|
|
}
|
|
|
|
return &bufConn{Conn: conn, r: r}, nil
|
|
}
|
|
|
|
// newProxyDialer returns a dialer that connects to proxy first if necessary.
|
|
// The returned dialer checks if a proxy is necessary, dial to the proxy with the
|
|
// provided dialer, does HTTP CONNECT handshake and returns the connection.
|
|
func newProxyDialer(dialer func(context.Context, string) (net.Conn, error)) func(context.Context, string) (net.Conn, error) {
|
|
return func(ctx context.Context, addr string) (conn net.Conn, err error) {
|
|
var skipHandshake bool
|
|
newAddr, err := mapAddress(ctx, addr)
|
|
if err != nil {
|
|
if err != errDisabled {
|
|
return nil, err
|
|
}
|
|
skipHandshake = true
|
|
newAddr = addr
|
|
}
|
|
|
|
conn, err = dialer(ctx, newAddr)
|
|
if err != nil {
|
|
return
|
|
}
|
|
if !skipHandshake {
|
|
conn, err = doHTTPConnectHandshake(ctx, conn, addr)
|
|
}
|
|
return
|
|
}
|
|
}
|