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Diffstat (limited to 'vendor/google.golang.org/grpc/proxy.go')
-rw-r--r--vendor/google.golang.org/grpc/proxy.go152
1 files changed, 152 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/proxy.go b/vendor/google.golang.org/grpc/proxy.go
new file mode 100644
index 000000000..f8f69bfb7
--- /dev/null
+++ b/vendor/google.golang.org/grpc/proxy.go
@@ -0,0 +1,152 @@
+/*
+ *
+ * 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"
+ "context"
+ "encoding/base64"
+ "errors"
+ "fmt"
+ "io"
+ "net"
+ "net/http"
+ "net/http/httputil"
+ "net/url"
+)
+
+const proxyAuthHeaderKey = "Proxy-Authorization"
+
+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) (*url.URL, error) {
+ req := &http.Request{
+ URL: &url.URL{
+ Scheme: "https",
+ Host: address,
+ },
+ }
+ url, err := httpProxyFromEnvironment(req)
+ if err != nil {
+ return nil, err
+ }
+ if url == nil {
+ return nil, errDisabled
+ }
+ return url, 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 basicAuth(username, password string) string {
+ auth := username + ":" + password
+ return base64.StdEncoding.EncodeToString([]byte(auth))
+}
+
+func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, backendAddr string, proxyURL *url.URL) (_ net.Conn, err error) {
+ defer func() {
+ if err != nil {
+ conn.Close()
+ }
+ }()
+
+ req := &http.Request{
+ Method: http.MethodConnect,
+ URL: &url.URL{Host: backendAddr},
+ Header: map[string][]string{"User-Agent": {grpcUA}},
+ }
+ if t := proxyURL.User; t != nil {
+ u := t.Username()
+ p, _ := t.Password()
+ req.Header.Add(proxyAuthHeaderKey, "Basic "+basicAuth(u, p))
+ }
+
+ 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 newAddr string
+ proxyURL, err := mapAddress(ctx, addr)
+ if err != nil {
+ if err != errDisabled {
+ return nil, err
+ }
+ newAddr = addr
+ } else {
+ newAddr = proxyURL.Host
+ }
+
+ conn, err = dialer(ctx, newAddr)
+ if err != nil {
+ return
+ }
+ if proxyURL != nil {
+ // proxy is disabled if proxyURL is nil.
+ conn, err = doHTTPConnectHandshake(ctx, conn, addr, proxyURL)
+ }
+ return
+ }
+}
+
+func sendHTTPRequest(ctx context.Context, req *http.Request, conn net.Conn) error {
+ req = req.WithContext(ctx)
+ if err := req.Write(conn); err != nil {
+ return fmt.Errorf("failed to write the HTTP request: %v", err)
+ }
+ return nil
+}