diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/proxy.go')
-rw-r--r-- | vendor/google.golang.org/grpc/proxy.go | 130 |
1 files changed, 130 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 0000000..2d40236 --- /dev/null +++ b/vendor/google.golang.org/grpc/proxy.go | |||
@@ -0,0 +1,130 @@ | |||
1 | /* | ||
2 | * | ||
3 | * Copyright 2017 gRPC authors. | ||
4 | * | ||
5 | * Licensed under the Apache License, Version 2.0 (the "License"); | ||
6 | * you may not use this file except in compliance with the License. | ||
7 | * You may obtain a copy of the License at | ||
8 | * | ||
9 | * http://www.apache.org/licenses/LICENSE-2.0 | ||
10 | * | ||
11 | * Unless required by applicable law or agreed to in writing, software | ||
12 | * distributed under the License is distributed on an "AS IS" BASIS, | ||
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
14 | * See the License for the specific language governing permissions and | ||
15 | * limitations under the License. | ||
16 | * | ||
17 | */ | ||
18 | |||
19 | package grpc | ||
20 | |||
21 | import ( | ||
22 | "bufio" | ||
23 | "errors" | ||
24 | "fmt" | ||
25 | "io" | ||
26 | "net" | ||
27 | "net/http" | ||
28 | "net/http/httputil" | ||
29 | "net/url" | ||
30 | |||
31 | "golang.org/x/net/context" | ||
32 | ) | ||
33 | |||
34 | var ( | ||
35 | // errDisabled indicates that proxy is disabled for the address. | ||
36 | errDisabled = errors.New("proxy is disabled for the address") | ||
37 | // The following variable will be overwritten in the tests. | ||
38 | httpProxyFromEnvironment = http.ProxyFromEnvironment | ||
39 | ) | ||
40 | |||
41 | func mapAddress(ctx context.Context, address string) (string, error) { | ||
42 | req := &http.Request{ | ||
43 | URL: &url.URL{ | ||
44 | Scheme: "https", | ||
45 | Host: address, | ||
46 | }, | ||
47 | } | ||
48 | url, err := httpProxyFromEnvironment(req) | ||
49 | if err != nil { | ||
50 | return "", err | ||
51 | } | ||
52 | if url == nil { | ||
53 | return "", errDisabled | ||
54 | } | ||
55 | return url.Host, nil | ||
56 | } | ||
57 | |||
58 | // To read a response from a net.Conn, http.ReadResponse() takes a bufio.Reader. | ||
59 | // It's possible that this reader reads more than what's need for the response and stores | ||
60 | // those bytes in the buffer. | ||
61 | // bufConn wraps the original net.Conn and the bufio.Reader to make sure we don't lose the | ||
62 | // bytes in the buffer. | ||
63 | type bufConn struct { | ||
64 | net.Conn | ||
65 | r io.Reader | ||
66 | } | ||
67 | |||
68 | func (c *bufConn) Read(b []byte) (int, error) { | ||
69 | return c.r.Read(b) | ||
70 | } | ||
71 | |||
72 | func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, addr string) (_ net.Conn, err error) { | ||
73 | defer func() { | ||
74 | if err != nil { | ||
75 | conn.Close() | ||
76 | } | ||
77 | }() | ||
78 | |||
79 | req := (&http.Request{ | ||
80 | Method: http.MethodConnect, | ||
81 | URL: &url.URL{Host: addr}, | ||
82 | Header: map[string][]string{"User-Agent": {grpcUA}}, | ||
83 | }) | ||
84 | |||
85 | if err := sendHTTPRequest(ctx, req, conn); err != nil { | ||
86 | return nil, fmt.Errorf("failed to write the HTTP request: %v", err) | ||
87 | } | ||
88 | |||
89 | r := bufio.NewReader(conn) | ||
90 | resp, err := http.ReadResponse(r, req) | ||
91 | if err != nil { | ||
92 | return nil, fmt.Errorf("reading server HTTP response: %v", err) | ||
93 | } | ||
94 | defer resp.Body.Close() | ||
95 | if resp.StatusCode != http.StatusOK { | ||
96 | dump, err := httputil.DumpResponse(resp, true) | ||
97 | if err != nil { | ||
98 | return nil, fmt.Errorf("failed to do connect handshake, status code: %s", resp.Status) | ||
99 | } | ||
100 | return nil, fmt.Errorf("failed to do connect handshake, response: %q", dump) | ||
101 | } | ||
102 | |||
103 | return &bufConn{Conn: conn, r: r}, nil | ||
104 | } | ||
105 | |||
106 | // newProxyDialer returns a dialer that connects to proxy first if necessary. | ||
107 | // The returned dialer checks if a proxy is necessary, dial to the proxy with the | ||
108 | // provided dialer, does HTTP CONNECT handshake and returns the connection. | ||
109 | func newProxyDialer(dialer func(context.Context, string) (net.Conn, error)) func(context.Context, string) (net.Conn, error) { | ||
110 | return func(ctx context.Context, addr string) (conn net.Conn, err error) { | ||
111 | var skipHandshake bool | ||
112 | newAddr, err := mapAddress(ctx, addr) | ||
113 | if err != nil { | ||
114 | if err != errDisabled { | ||
115 | return nil, err | ||
116 | } | ||
117 | skipHandshake = true | ||
118 | newAddr = addr | ||
119 | } | ||
120 | |||
121 | conn, err = dialer(ctx, newAddr) | ||
122 | if err != nil { | ||
123 | return | ||
124 | } | ||
125 | if !skipHandshake { | ||
126 | conn, err = doHTTPConnectHandshake(ctx, conn, addr) | ||
127 | } | ||
128 | return | ||
129 | } | ||
130 | } | ||