mirror of https://github.com/grpc/grpc-go.git
131 lines
3.4 KiB
Go
131 lines
3.4 KiB
Go
/*
|
|
*
|
|
* Copyright 2017 gRPC 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.
|
|
*
|
|
*/
|
|
|
|
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
|
|
}
|
|
}
|