3 * Copyright 2016 gRPC authors.
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
9 * http://www.apache.org/licenses/LICENSE-2.0
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.
19 #include <grpc/support/port_platform.h>
21 #include "src/core/ext/filters/client_channel/http_proxy.h"
26 #include <grpc/support/alloc.h>
27 #include <grpc/support/log.h>
28 #include <grpc/support/string_util.h>
30 #include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
31 #include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
32 #include "src/core/lib/channel/channel_args.h"
33 #include "src/core/lib/gpr/env.h"
34 #include "src/core/lib/gpr/string.h"
35 #include "src/core/lib/gprpp/host_port.h"
36 #include "src/core/lib/slice/b64.h"
37 #include "src/core/lib/uri/uri_parser.h"
40 * Parses the 'https_proxy' env var (fallback on 'http_proxy') and returns the
41 * proxy hostname to resolve or nullptr on error. Also sets 'user_cred' to user
42 * credentials if present in the 'http_proxy' env var, otherwise leaves it
43 * unchanged. It is caller's responsibility to gpr_free user_cred.
45 static char* get_http_proxy_server(char** user_cred) {
46 GPR_ASSERT(user_cred != nullptr);
47 char* proxy_name = nullptr;
48 char** authority_strs = nullptr;
49 size_t authority_nstrs;
50 /* Prefer using 'grpc_proxy'. Fallback on 'http_proxy' if it is not set.
51 * Also prefer using 'https_proxy' with fallback on 'http_proxy'. The
52 * fallback behavior can be removed if there's a demand for it.
54 char* uri_str = gpr_getenv("grpc_proxy");
55 if (uri_str == nullptr) uri_str = gpr_getenv("https_proxy");
56 if (uri_str == nullptr) uri_str = gpr_getenv("http_proxy");
57 if (uri_str == nullptr) return nullptr;
58 grpc_uri* uri = grpc_uri_parse(uri_str, false /* suppress_errors */);
59 if (uri == nullptr || uri->authority == nullptr) {
60 gpr_log(GPR_ERROR, "cannot parse value of 'http_proxy' env var");
63 if (strcmp(uri->scheme, "http") != 0) {
64 gpr_log(GPR_ERROR, "'%s' scheme not supported in proxy URI", uri->scheme);
67 /* Split on '@' to separate user credentials from host */
68 gpr_string_split(uri->authority, "@", &authority_strs, &authority_nstrs);
69 GPR_ASSERT(authority_nstrs != 0); /* should have at least 1 string */
70 if (authority_nstrs == 1) {
71 /* User cred not present in authority */
72 proxy_name = authority_strs[0];
73 } else if (authority_nstrs == 2) {
75 *user_cred = authority_strs[0];
76 proxy_name = authority_strs[1];
77 gpr_log(GPR_DEBUG, "userinfo found in proxy URI");
80 for (size_t i = 0; i < authority_nstrs; i++) {
81 gpr_free(authority_strs[i]);
85 gpr_free(authority_strs);
88 grpc_uri_destroy(uri);
93 * Checks the value of GRPC_ARG_ENABLE_HTTP_PROXY to determine if http_proxy
96 bool http_proxy_enabled(const grpc_channel_args* args) {
98 grpc_channel_args_find(args, GRPC_ARG_ENABLE_HTTP_PROXY);
99 return grpc_channel_arg_get_bool(arg, true);
102 static bool proxy_mapper_map_name(grpc_proxy_mapper* mapper,
103 const char* server_uri,
104 const grpc_channel_args* args,
105 char** name_to_resolve,
106 grpc_channel_args** new_args) {
107 if (!http_proxy_enabled(args)) {
110 char* user_cred = nullptr;
111 *name_to_resolve = get_http_proxy_server(&user_cred);
112 if (*name_to_resolve == nullptr) return false;
113 char* no_proxy_str = nullptr;
114 grpc_uri* uri = grpc_uri_parse(server_uri, false /* suppress_errors */);
115 if (uri == nullptr || uri->path[0] == '\0') {
117 "'http_proxy' environment variable set, but cannot "
118 "parse server URI '%s' -- not using proxy",
122 if (strcmp(uri->scheme, "unix") == 0) {
123 gpr_log(GPR_INFO, "not using proxy for Unix domain socket '%s'",
127 /* Prefer using 'no_grpc_proxy'. Fallback on 'no_proxy' if it is not set. */
128 no_proxy_str = gpr_getenv("no_grpc_proxy");
129 if (no_proxy_str == nullptr) no_proxy_str = gpr_getenv("no_proxy");
130 if (no_proxy_str != nullptr) {
131 static const char* NO_PROXY_SEPARATOR = ",";
132 bool use_proxy = true;
133 grpc_core::UniquePtr<char> server_host;
134 grpc_core::UniquePtr<char> server_port;
135 if (!grpc_core::SplitHostPort(
136 uri->path[0] == '/' ? uri->path + 1 : uri->path, &server_host,
139 "unable to split host and port, not checking no_proxy list for "
142 gpr_free(no_proxy_str);
144 size_t uri_len = strlen(server_host.get());
145 char** no_proxy_hosts;
146 size_t num_no_proxy_hosts;
147 gpr_string_split(no_proxy_str, NO_PROXY_SEPARATOR, &no_proxy_hosts,
148 &num_no_proxy_hosts);
149 for (size_t i = 0; i < num_no_proxy_hosts; i++) {
150 char* no_proxy_entry = no_proxy_hosts[i];
151 size_t no_proxy_len = strlen(no_proxy_entry);
152 if (no_proxy_len <= uri_len &&
153 gpr_stricmp(no_proxy_entry,
154 &(server_host.get()[uri_len - no_proxy_len])) == 0) {
155 gpr_log(GPR_INFO, "not using proxy for host in no_proxy list '%s'",
161 for (size_t i = 0; i < num_no_proxy_hosts; i++) {
162 gpr_free(no_proxy_hosts[i]);
164 gpr_free(no_proxy_hosts);
165 gpr_free(no_proxy_str);
166 if (!use_proxy) goto no_use_proxy;
169 grpc_arg args_to_add[2];
170 args_to_add[0] = grpc_channel_arg_string_create(
171 (char*)GRPC_ARG_HTTP_CONNECT_SERVER,
172 uri->path[0] == '/' ? uri->path + 1 : uri->path);
173 if (user_cred != nullptr) {
174 /* Use base64 encoding for user credentials as stated in RFC 7617 */
175 char* encoded_user_cred =
176 grpc_base64_encode(user_cred, strlen(user_cred), 0, 0);
178 gpr_asprintf(&header, "Proxy-Authorization:Basic %s", encoded_user_cred);
179 gpr_free(encoded_user_cred);
180 args_to_add[1] = grpc_channel_arg_string_create(
181 (char*)GRPC_ARG_HTTP_CONNECT_HEADERS, header);
182 *new_args = grpc_channel_args_copy_and_add(args, args_to_add, 2);
185 *new_args = grpc_channel_args_copy_and_add(args, args_to_add, 1);
187 grpc_uri_destroy(uri);
191 if (uri != nullptr) grpc_uri_destroy(uri);
192 gpr_free(*name_to_resolve);
193 *name_to_resolve = nullptr;
198 static bool proxy_mapper_map_address(grpc_proxy_mapper* mapper,
199 const grpc_resolved_address* address,
200 const grpc_channel_args* args,
201 grpc_resolved_address** new_address,
202 grpc_channel_args** new_args) {
206 static void proxy_mapper_destroy(grpc_proxy_mapper* mapper) {}
208 static const grpc_proxy_mapper_vtable proxy_mapper_vtable = {
209 proxy_mapper_map_name, proxy_mapper_map_address, proxy_mapper_destroy};
211 static grpc_proxy_mapper proxy_mapper = {&proxy_mapper_vtable};
213 void grpc_register_http_proxy_mapper() {
214 grpc_proxy_mapper_register(true /* at_start */, &proxy_mapper);