Hulk did something

[bytom/vapor.git] / vendor / google.golang.org / grpc / proxy.go

diff --git a/vendor/google.golang.org/grpc/proxy.go b/vendor/google.golang.org/grpc/proxy.go
new file mode 100644 (file)
index 0000000..2d40236
--- /dev/null
+++ b/vendor/google.golang.org/grpc/proxy.go
@@ -0,0 +1,130 @@
+/*
+ *
+ * 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
+       }
+}