1 /*
2 *
3 * Copyright 2016 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 #include <grpc/support/port_platform.h>
20
21 #include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
22
23 #include <string.h>
24
25 #include <grpc/slice_buffer.h>
26 #include <grpc/support/alloc.h>
27 #include <grpc/support/log.h>
28 #include <grpc/support/string_util.h>
29
30 #include "src/core/ext/filters/client_channel/client_channel.h"
31 #include "src/core/ext/filters/client_channel/resolver_registry.h"
32 #include "src/core/ext/filters/client_channel/uri_parser.h"
33 #include "src/core/lib/channel/channel_args.h"
34 #include "src/core/lib/channel/handshaker_registry.h"
35 #include "src/core/lib/gpr/env.h"
36 #include "src/core/lib/gpr/string.h"
37 #include "src/core/lib/http/format_request.h"
38 #include "src/core/lib/http/parser.h"
39 #include "src/core/lib/slice/slice_internal.h"
40
41 typedef struct http_connect_handshaker {
42 // Base class. Must be first.
43 grpc_handshaker base;
44
45 gpr_refcount refcount;
46 gpr_mu mu;
47
48 bool shutdown;
49 // Endpoint and read buffer to destroy after a shutdown.
50 grpc_endpoint* endpoint_to_destroy;
51 grpc_slice_buffer* read_buffer_to_destroy;
52
53 // State saved while performing the handshake.
54 grpc_handshaker_args* args;
55 grpc_closure* on_handshake_done;
56
57 // Objects for processing the HTTP CONNECT request and response.
58 grpc_slice_buffer write_buffer;
59 grpc_closure request_done_closure;
60 grpc_closure response_read_closure;
61 grpc_http_parser http_parser;
62 grpc_http_response http_response;
63 } http_connect_handshaker;
64
65 // Unref and clean up handshaker.
http_connect_handshaker_unref(http_connect_handshaker * handshaker)66 static void http_connect_handshaker_unref(http_connect_handshaker* handshaker) {
67 if (gpr_unref(&handshaker->refcount)) {
68 gpr_mu_destroy(&handshaker->mu);
69 if (handshaker->endpoint_to_destroy != nullptr) {
70 grpc_endpoint_destroy(handshaker->endpoint_to_destroy);
71 }
72 if (handshaker->read_buffer_to_destroy != nullptr) {
73 grpc_slice_buffer_destroy_internal(handshaker->read_buffer_to_destroy);
74 gpr_free(handshaker->read_buffer_to_destroy);
75 }
76 grpc_slice_buffer_destroy_internal(&handshaker->write_buffer);
77 grpc_http_parser_destroy(&handshaker->http_parser);
78 grpc_http_response_destroy(&handshaker->http_response);
79 gpr_free(handshaker);
80 }
81 }
82
83 // Set args fields to nullptr, saving the endpoint and read buffer for
84 // later destruction.
cleanup_args_for_failure_locked(http_connect_handshaker * handshaker)85 static void cleanup_args_for_failure_locked(
86 http_connect_handshaker* handshaker) {
87 handshaker->endpoint_to_destroy = handshaker->args->endpoint;
88 handshaker->args->endpoint = nullptr;
89 handshaker->read_buffer_to_destroy = handshaker->args->read_buffer;
90 handshaker->args->read_buffer = nullptr;
91 grpc_channel_args_destroy(handshaker->args->args);
92 handshaker->args->args = nullptr;
93 }
94
95 // If the handshake failed or we're shutting down, clean up and invoke the
96 // callback with the error.
handshake_failed_locked(http_connect_handshaker * handshaker,grpc_error * error)97 static void handshake_failed_locked(http_connect_handshaker* handshaker,
98 grpc_error* error) {
99 if (error == GRPC_ERROR_NONE) {
100 // If we were shut down after an endpoint operation succeeded but
101 // before the endpoint callback was invoked, we need to generate our
102 // own error.
103 error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Handshaker shutdown");
104 }
105 if (!handshaker->shutdown) {
106 // TODO(ctiller): It is currently necessary to shutdown endpoints
107 // before destroying them, even if we know that there are no
108 // pending read/write callbacks. This should be fixed, at which
109 // point this can be removed.
110 grpc_endpoint_shutdown(handshaker->args->endpoint, GRPC_ERROR_REF(error));
111 // Not shutting down, so the handshake failed. Clean up before
112 // invoking the callback.
113 cleanup_args_for_failure_locked(handshaker);
114 // Set shutdown to true so that subsequent calls to
115 // http_connect_handshaker_shutdown() do nothing.
116 handshaker->shutdown = true;
117 }
118 // Invoke callback.
119 GRPC_CLOSURE_SCHED(handshaker->on_handshake_done, error);
120 }
121
122 // Callback invoked when finished writing HTTP CONNECT request.
on_write_done(void * arg,grpc_error * error)123 static void on_write_done(void* arg, grpc_error* error) {
124 http_connect_handshaker* handshaker =
125 static_cast<http_connect_handshaker*>(arg);
126 gpr_mu_lock(&handshaker->mu);
127 if (error != GRPC_ERROR_NONE || handshaker->shutdown) {
128 // If the write failed or we're shutting down, clean up and invoke the
129 // callback with the error.
130 handshake_failed_locked(handshaker, GRPC_ERROR_REF(error));
131 gpr_mu_unlock(&handshaker->mu);
132 http_connect_handshaker_unref(handshaker);
133 } else {
134 // Otherwise, read the response.
135 // The read callback inherits our ref to the handshaker.
136 grpc_endpoint_read(handshaker->args->endpoint,
137 handshaker->args->read_buffer,
138 &handshaker->response_read_closure);
139 gpr_mu_unlock(&handshaker->mu);
140 }
141 }
142
143 // Callback invoked for reading HTTP CONNECT response.
on_read_done(void * arg,grpc_error * error)144 static void on_read_done(void* arg, grpc_error* error) {
145 http_connect_handshaker* handshaker =
146 static_cast<http_connect_handshaker*>(arg);
147 gpr_mu_lock(&handshaker->mu);
148 if (error != GRPC_ERROR_NONE || handshaker->shutdown) {
149 // If the read failed or we're shutting down, clean up and invoke the
150 // callback with the error.
151 handshake_failed_locked(handshaker, GRPC_ERROR_REF(error));
152 goto done;
153 }
154 // Add buffer to parser.
155 for (size_t i = 0; i < handshaker->args->read_buffer->count; ++i) {
156 if (GRPC_SLICE_LENGTH(handshaker->args->read_buffer->slices[i]) > 0) {
157 size_t body_start_offset = 0;
158 error = grpc_http_parser_parse(&handshaker->http_parser,
159 handshaker->args->read_buffer->slices[i],
160 &body_start_offset);
161 if (error != GRPC_ERROR_NONE) {
162 handshake_failed_locked(handshaker, error);
163 goto done;
164 }
165 if (handshaker->http_parser.state == GRPC_HTTP_BODY) {
166 // Remove the data we've already read from the read buffer,
167 // leaving only the leftover bytes (if any).
168 grpc_slice_buffer tmp_buffer;
169 grpc_slice_buffer_init(&tmp_buffer);
170 if (body_start_offset <
171 GRPC_SLICE_LENGTH(handshaker->args->read_buffer->slices[i])) {
172 grpc_slice_buffer_add(
173 &tmp_buffer,
174 grpc_slice_split_tail(&handshaker->args->read_buffer->slices[i],
175 body_start_offset));
176 }
177 grpc_slice_buffer_addn(&tmp_buffer,
178 &handshaker->args->read_buffer->slices[i + 1],
179 handshaker->args->read_buffer->count - i - 1);
180 grpc_slice_buffer_swap(handshaker->args->read_buffer, &tmp_buffer);
181 grpc_slice_buffer_destroy_internal(&tmp_buffer);
182 break;
183 }
184 }
185 }
186 // If we're not done reading the response, read more data.
187 // TODO(roth): In practice, I suspect that the response to a CONNECT
188 // request will never include a body, in which case this check is
189 // sufficient. However, the language of RFC-2817 doesn't explicitly
190 // forbid the response from including a body. If there is a body,
191 // it's possible that we might have parsed part but not all of the
192 // body, in which case this check will cause us to fail to parse the
193 // remainder of the body. If that ever becomes an issue, we may
194 // need to fix the HTTP parser to understand when the body is
195 // complete (e.g., handling chunked transfer encoding or looking
196 // at the Content-Length: header).
197 if (handshaker->http_parser.state != GRPC_HTTP_BODY) {
198 grpc_slice_buffer_reset_and_unref_internal(handshaker->args->read_buffer);
199 grpc_endpoint_read(handshaker->args->endpoint,
200 handshaker->args->read_buffer,
201 &handshaker->response_read_closure);
202 gpr_mu_unlock(&handshaker->mu);
203 return;
204 }
205 // Make sure we got a 2xx response.
206 if (handshaker->http_response.status < 200 ||
207 handshaker->http_response.status >= 300) {
208 char* msg;
209 gpr_asprintf(&msg, "HTTP proxy returned response code %d",
210 handshaker->http_response.status);
211 error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
212 gpr_free(msg);
213 handshake_failed_locked(handshaker, error);
214 goto done;
215 }
216 // Success. Invoke handshake-done callback.
217 GRPC_CLOSURE_SCHED(handshaker->on_handshake_done, error);
218 done:
219 // Set shutdown to true so that subsequent calls to
220 // http_connect_handshaker_shutdown() do nothing.
221 handshaker->shutdown = true;
222 gpr_mu_unlock(&handshaker->mu);
223 http_connect_handshaker_unref(handshaker);
224 }
225
226 //
227 // Public handshaker methods
228 //
229
http_connect_handshaker_destroy(grpc_handshaker * handshaker_in)230 static void http_connect_handshaker_destroy(grpc_handshaker* handshaker_in) {
231 http_connect_handshaker* handshaker =
232 reinterpret_cast<http_connect_handshaker*>(handshaker_in);
233 http_connect_handshaker_unref(handshaker);
234 }
235
http_connect_handshaker_shutdown(grpc_handshaker * handshaker_in,grpc_error * why)236 static void http_connect_handshaker_shutdown(grpc_handshaker* handshaker_in,
237 grpc_error* why) {
238 http_connect_handshaker* handshaker =
239 reinterpret_cast<http_connect_handshaker*>(handshaker_in);
240 gpr_mu_lock(&handshaker->mu);
241 if (!handshaker->shutdown) {
242 handshaker->shutdown = true;
243 grpc_endpoint_shutdown(handshaker->args->endpoint, GRPC_ERROR_REF(why));
244 cleanup_args_for_failure_locked(handshaker);
245 }
246 gpr_mu_unlock(&handshaker->mu);
247 GRPC_ERROR_UNREF(why);
248 }
249
http_connect_handshaker_do_handshake(grpc_handshaker * handshaker_in,grpc_tcp_server_acceptor * acceptor,grpc_closure * on_handshake_done,grpc_handshaker_args * args)250 static void http_connect_handshaker_do_handshake(
251 grpc_handshaker* handshaker_in, grpc_tcp_server_acceptor* acceptor,
252 grpc_closure* on_handshake_done, grpc_handshaker_args* args) {
253 http_connect_handshaker* handshaker =
254 reinterpret_cast<http_connect_handshaker*>(handshaker_in);
255 // Check for HTTP CONNECT channel arg.
256 // If not found, invoke on_handshake_done without doing anything.
257 const grpc_arg* arg =
258 grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_SERVER);
259 char* server_name = grpc_channel_arg_get_string(arg);
260 if (server_name == nullptr) {
261 // Set shutdown to true so that subsequent calls to
262 // http_connect_handshaker_shutdown() do nothing.
263 gpr_mu_lock(&handshaker->mu);
264 handshaker->shutdown = true;
265 gpr_mu_unlock(&handshaker->mu);
266 GRPC_CLOSURE_SCHED(on_handshake_done, GRPC_ERROR_NONE);
267 return;
268 }
269 // Get headers from channel args.
270 arg = grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_HEADERS);
271 char* arg_header_string = grpc_channel_arg_get_string(arg);
272 grpc_http_header* headers = nullptr;
273 size_t num_headers = 0;
274 char** header_strings = nullptr;
275 size_t num_header_strings = 0;
276 if (arg_header_string != nullptr) {
277 gpr_string_split(arg_header_string, "\n", &header_strings,
278 &num_header_strings);
279 headers = static_cast<grpc_http_header*>(
280 gpr_malloc(sizeof(grpc_http_header) * num_header_strings));
281 for (size_t i = 0; i < num_header_strings; ++i) {
282 char* sep = strchr(header_strings[i], ':');
283 if (sep == nullptr) {
284 gpr_log(GPR_ERROR, "skipping unparseable HTTP CONNECT header: %s",
285 header_strings[i]);
286 continue;
287 }
288 *sep = '\0';
289 headers[num_headers].key = header_strings[i];
290 headers[num_headers].value = sep + 1;
291 ++num_headers;
292 }
293 }
294 // Save state in the handshaker object.
295 gpr_mu_lock(&handshaker->mu);
296 handshaker->args = args;
297 handshaker->on_handshake_done = on_handshake_done;
298 // Log connection via proxy.
299 char* proxy_name = grpc_endpoint_get_peer(args->endpoint);
300 gpr_log(GPR_INFO, "Connecting to server %s via HTTP proxy %s", server_name,
301 proxy_name);
302 gpr_free(proxy_name);
303 // Construct HTTP CONNECT request.
304 grpc_httpcli_request request;
305 memset(&request, 0, sizeof(request));
306 request.host = server_name;
307 request.http.method = (char*)"CONNECT";
308 request.http.path = server_name;
309 request.http.hdrs = headers;
310 request.http.hdr_count = num_headers;
311 request.handshaker = &grpc_httpcli_plaintext;
312 grpc_slice request_slice = grpc_httpcli_format_connect_request(&request);
313 grpc_slice_buffer_add(&handshaker->write_buffer, request_slice);
314 // Clean up.
315 gpr_free(headers);
316 for (size_t i = 0; i < num_header_strings; ++i) {
317 gpr_free(header_strings[i]);
318 }
319 gpr_free(header_strings);
320 // Take a new ref to be held by the write callback.
321 gpr_ref(&handshaker->refcount);
322 grpc_endpoint_write(args->endpoint, &handshaker->write_buffer,
323 &handshaker->request_done_closure, nullptr);
324 gpr_mu_unlock(&handshaker->mu);
325 }
326
327 static const grpc_handshaker_vtable http_connect_handshaker_vtable = {
328 http_connect_handshaker_destroy, http_connect_handshaker_shutdown,
329 http_connect_handshaker_do_handshake, "http_connect"};
330
grpc_http_connect_handshaker_create()331 static grpc_handshaker* grpc_http_connect_handshaker_create() {
332 http_connect_handshaker* handshaker =
333 static_cast<http_connect_handshaker*>(gpr_malloc(sizeof(*handshaker)));
334 memset(handshaker, 0, sizeof(*handshaker));
335 grpc_handshaker_init(&http_connect_handshaker_vtable, &handshaker->base);
336 gpr_mu_init(&handshaker->mu);
337 gpr_ref_init(&handshaker->refcount, 1);
338 grpc_slice_buffer_init(&handshaker->write_buffer);
339 GRPC_CLOSURE_INIT(&handshaker->request_done_closure, on_write_done,
340 handshaker, grpc_schedule_on_exec_ctx);
341 GRPC_CLOSURE_INIT(&handshaker->response_read_closure, on_read_done,
342 handshaker, grpc_schedule_on_exec_ctx);
343 grpc_http_parser_init(&handshaker->http_parser, GRPC_HTTP_RESPONSE,
344 &handshaker->http_response);
345 return &handshaker->base;
346 }
347
348 //
349 // handshaker factory
350 //
351
handshaker_factory_add_handshakers(grpc_handshaker_factory * factory,const grpc_channel_args * args,grpc_handshake_manager * handshake_mgr)352 static void handshaker_factory_add_handshakers(
353 grpc_handshaker_factory* factory, const grpc_channel_args* args,
354 grpc_handshake_manager* handshake_mgr) {
355 grpc_handshake_manager_add(handshake_mgr,
356 grpc_http_connect_handshaker_create());
357 }
358
handshaker_factory_destroy(grpc_handshaker_factory * factory)359 static void handshaker_factory_destroy(grpc_handshaker_factory* factory) {}
360
361 static const grpc_handshaker_factory_vtable handshaker_factory_vtable = {
362 handshaker_factory_add_handshakers, handshaker_factory_destroy};
363
364 static grpc_handshaker_factory handshaker_factory = {
365 &handshaker_factory_vtable};
366
grpc_http_connect_register_handshaker_factory()367 void grpc_http_connect_register_handshaker_factory() {
368 grpc_handshaker_factory_register(true /* at_start */, HANDSHAKER_CLIENT,
369 &handshaker_factory);
370 }
371