1 /*
2 * Copyright 2015 gRPC authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 */
17
18 #include <grpc/support/port_platform.h>
19
20 #include <stdint.h>
21 #include <string.h>
22
23 #include <string>
24 #include <vector>
25
26 #include "absl/strings/str_cat.h"
27 #include "absl/strings/str_format.h"
28 #include "absl/strings/str_join.h"
29
30 #include <grpc/support/alloc.h>
31 #include <grpc/support/log.h>
32
33 #include "src/core/ext/filters/http/client/http_client_filter.h"
34 #include "src/core/lib/gpr/string.h"
35 #include "src/core/lib/gprpp/manual_constructor.h"
36 #include "src/core/lib/profiling/timers.h"
37 #include "src/core/lib/slice/b64.h"
38 #include "src/core/lib/slice/percent_encoding.h"
39 #include "src/core/lib/slice/slice_internal.h"
40 #include "src/core/lib/slice/slice_string_helpers.h"
41 #include "src/core/lib/transport/static_metadata.h"
42 #include "src/core/lib/transport/status_conversion.h"
43 #include "src/core/lib/transport/transport_impl.h"
44
45 #define EXPECTED_CONTENT_TYPE "application/grpc"
46 #define EXPECTED_CONTENT_TYPE_LENGTH (sizeof(EXPECTED_CONTENT_TYPE) - 1)
47
48 /* default maximum size of payload eligible for GET request */
49 static constexpr size_t kMaxPayloadSizeForGet = 2048;
50
51 static void recv_initial_metadata_ready(void* user_data, grpc_error* error);
52 static void recv_trailing_metadata_ready(void* user_data, grpc_error* error);
53 static void on_send_message_next_done(void* arg, grpc_error* error);
54 static void send_message_on_complete(void* arg, grpc_error* error);
55
56 namespace {
57 struct call_data {
call_data__anon98190a490111::call_data58 call_data(grpc_call_element* elem, const grpc_call_element_args& args)
59 : call_combiner(args.call_combiner) {
60 GRPC_CLOSURE_INIT(&recv_initial_metadata_ready,
61 ::recv_initial_metadata_ready, elem,
62 grpc_schedule_on_exec_ctx);
63 GRPC_CLOSURE_INIT(&recv_trailing_metadata_ready,
64 ::recv_trailing_metadata_ready, elem,
65 grpc_schedule_on_exec_ctx);
66 GRPC_CLOSURE_INIT(&on_send_message_next_done, ::on_send_message_next_done,
67 elem, grpc_schedule_on_exec_ctx);
68 GRPC_CLOSURE_INIT(&send_message_on_complete, ::send_message_on_complete,
69 elem, grpc_schedule_on_exec_ctx);
70 }
71
~call_data__anon98190a490111::call_data72 ~call_data() { GRPC_ERROR_UNREF(recv_initial_metadata_error); }
73
74 grpc_core::CallCombiner* call_combiner;
75 // State for handling send_initial_metadata ops.
76 grpc_linked_mdelem method;
77 grpc_linked_mdelem scheme;
78 grpc_linked_mdelem authority;
79 grpc_linked_mdelem te_trailers;
80 grpc_linked_mdelem content_type;
81 grpc_linked_mdelem user_agent;
82 // State for handling recv_initial_metadata ops.
83 grpc_metadata_batch* recv_initial_metadata;
84 grpc_error* recv_initial_metadata_error = GRPC_ERROR_NONE;
85 grpc_closure* original_recv_initial_metadata_ready = nullptr;
86 grpc_closure recv_initial_metadata_ready;
87 // State for handling recv_trailing_metadata ops.
88 grpc_metadata_batch* recv_trailing_metadata;
89 grpc_closure* original_recv_trailing_metadata_ready;
90 grpc_closure recv_trailing_metadata_ready;
91 grpc_error* recv_trailing_metadata_error = GRPC_ERROR_NONE;
92 bool seen_recv_trailing_metadata_ready = false;
93 // State for handling send_message ops.
94 grpc_transport_stream_op_batch* send_message_batch;
95 size_t send_message_bytes_read = 0;
96 grpc_core::ManualConstructor<grpc_core::ByteStreamCache> send_message_cache;
97 grpc_core::ManualConstructor<grpc_core::ByteStreamCache::CachingByteStream>
98 send_message_caching_stream;
99 grpc_closure on_send_message_next_done;
100 grpc_closure* original_send_message_on_complete;
101 grpc_closure send_message_on_complete;
102 };
103
104 struct channel_data {
105 grpc_mdelem static_scheme;
106 grpc_mdelem user_agent;
107 size_t max_payload_size_for_get;
108 };
109 } // namespace
110
client_filter_incoming_metadata(grpc_metadata_batch * b)111 static grpc_error* client_filter_incoming_metadata(grpc_metadata_batch* b) {
112 if (b->idx.named.status != nullptr) {
113 /* If both gRPC status and HTTP status are provided in the response, we
114 * should prefer the gRPC status code, as mentioned in
115 * https://github.com/grpc/grpc/blob/master/doc/http-grpc-status-mapping.md.
116 */
117 if (b->idx.named.grpc_status != nullptr ||
118 grpc_mdelem_static_value_eq(b->idx.named.status->md,
119 GRPC_MDELEM_STATUS_200)) {
120 grpc_metadata_batch_remove(b, GRPC_BATCH_STATUS);
121 } else {
122 char* val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.status->md),
123 GPR_DUMP_ASCII);
124 std::string msg =
125 absl::StrCat("Received http2 header with status: ", val);
126 grpc_error* e = grpc_error_set_str(
127 grpc_error_set_int(
128 grpc_error_set_str(
129 GRPC_ERROR_CREATE_FROM_STATIC_STRING(
130 "Received http2 :status header with non-200 OK status"),
131 GRPC_ERROR_STR_VALUE, grpc_slice_from_copied_string(val)),
132 GRPC_ERROR_INT_GRPC_STATUS,
133 grpc_http2_status_to_grpc_status(atoi(val))),
134 GRPC_ERROR_STR_GRPC_MESSAGE,
135 grpc_slice_from_cpp_string(std::move(msg)));
136 gpr_free(val);
137 return e;
138 }
139 }
140
141 if (b->idx.named.grpc_message != nullptr) {
142 grpc_slice pct_decoded_msg = grpc_permissive_percent_decode_slice(
143 GRPC_MDVALUE(b->idx.named.grpc_message->md));
144 if (grpc_slice_is_equivalent(pct_decoded_msg,
145 GRPC_MDVALUE(b->idx.named.grpc_message->md))) {
146 grpc_slice_unref_internal(pct_decoded_msg);
147 } else {
148 grpc_metadata_batch_set_value(b->idx.named.grpc_message, pct_decoded_msg);
149 }
150 }
151
152 if (b->idx.named.content_type != nullptr) {
153 if (!grpc_mdelem_static_value_eq(
154 b->idx.named.content_type->md,
155 GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC)) {
156 if (grpc_slice_buf_start_eq(GRPC_MDVALUE(b->idx.named.content_type->md),
157 EXPECTED_CONTENT_TYPE,
158 EXPECTED_CONTENT_TYPE_LENGTH) &&
159 (GRPC_SLICE_START_PTR(GRPC_MDVALUE(
160 b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] ==
161 '+' ||
162 GRPC_SLICE_START_PTR(GRPC_MDVALUE(
163 b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] ==
164 ';')) {
165 /* Although the C implementation doesn't (currently) generate them,
166 any custom +-suffix is explicitly valid. */
167 /* TODO(klempner): We should consider preallocating common values such
168 as +proto or +json, or at least stashing them if we see them. */
169 /* TODO(klempner): Should we be surfacing this to application code? */
170 } else {
171 /* TODO(klempner): We're currently allowing this, but we shouldn't
172 see it without a proxy so log for now. */
173 char* val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.content_type->md),
174 GPR_DUMP_ASCII);
175 gpr_log(GPR_INFO, "Unexpected content-type '%s'", val);
176 gpr_free(val);
177 }
178 }
179 grpc_metadata_batch_remove(b, GRPC_BATCH_CONTENT_TYPE);
180 }
181
182 return GRPC_ERROR_NONE;
183 }
184
recv_initial_metadata_ready(void * user_data,grpc_error * error)185 static void recv_initial_metadata_ready(void* user_data, grpc_error* error) {
186 grpc_call_element* elem = static_cast<grpc_call_element*>(user_data);
187 call_data* calld = static_cast<call_data*>(elem->call_data);
188 if (error == GRPC_ERROR_NONE) {
189 error = client_filter_incoming_metadata(calld->recv_initial_metadata);
190 calld->recv_initial_metadata_error = GRPC_ERROR_REF(error);
191 } else {
192 GRPC_ERROR_REF(error);
193 }
194 grpc_closure* closure = calld->original_recv_initial_metadata_ready;
195 calld->original_recv_initial_metadata_ready = nullptr;
196 if (calld->seen_recv_trailing_metadata_ready) {
197 GRPC_CALL_COMBINER_START(
198 calld->call_combiner, &calld->recv_trailing_metadata_ready,
199 calld->recv_trailing_metadata_error, "continue recv_trailing_metadata");
200 }
201 grpc_core::Closure::Run(DEBUG_LOCATION, closure, error);
202 }
203
recv_trailing_metadata_ready(void * user_data,grpc_error * error)204 static void recv_trailing_metadata_ready(void* user_data, grpc_error* error) {
205 grpc_call_element* elem = static_cast<grpc_call_element*>(user_data);
206 call_data* calld = static_cast<call_data*>(elem->call_data);
207 if (calld->original_recv_initial_metadata_ready != nullptr) {
208 calld->recv_trailing_metadata_error = GRPC_ERROR_REF(error);
209 calld->seen_recv_trailing_metadata_ready = true;
210 GRPC_CALL_COMBINER_STOP(calld->call_combiner,
211 "deferring recv_trailing_metadata_ready until "
212 "after recv_initial_metadata_ready");
213 return;
214 }
215 if (error == GRPC_ERROR_NONE) {
216 error = client_filter_incoming_metadata(calld->recv_trailing_metadata);
217 } else {
218 GRPC_ERROR_REF(error);
219 }
220 error = grpc_error_add_child(
221 error, GRPC_ERROR_REF(calld->recv_initial_metadata_error));
222 grpc_core::Closure::Run(DEBUG_LOCATION,
223 calld->original_recv_trailing_metadata_ready, error);
224 }
225
send_message_on_complete(void * arg,grpc_error * error)226 static void send_message_on_complete(void* arg, grpc_error* error) {
227 grpc_call_element* elem = static_cast<grpc_call_element*>(arg);
228 call_data* calld = static_cast<call_data*>(elem->call_data);
229 calld->send_message_cache.Destroy();
230 grpc_core::Closure::Run(DEBUG_LOCATION,
231 calld->original_send_message_on_complete,
232 GRPC_ERROR_REF(error));
233 }
234
235 // Pulls a slice from the send_message byte stream, updating
236 // calld->send_message_bytes_read.
pull_slice_from_send_message(call_data * calld)237 static grpc_error* pull_slice_from_send_message(call_data* calld) {
238 grpc_slice incoming_slice;
239 grpc_error* error = calld->send_message_caching_stream->Pull(&incoming_slice);
240 if (error == GRPC_ERROR_NONE) {
241 calld->send_message_bytes_read += GRPC_SLICE_LENGTH(incoming_slice);
242 grpc_slice_unref_internal(incoming_slice);
243 }
244 return error;
245 }
246
247 // Reads as many slices as possible from the send_message byte stream.
248 // Upon successful return, if calld->send_message_bytes_read ==
249 // calld->send_message_caching_stream->length(), then we have completed
250 // reading from the byte stream; otherwise, an async read has been dispatched
251 // and on_send_message_next_done() will be invoked when it is complete.
read_all_available_send_message_data(call_data * calld)252 static grpc_error* read_all_available_send_message_data(call_data* calld) {
253 while (calld->send_message_caching_stream->Next(
254 SIZE_MAX, &calld->on_send_message_next_done)) {
255 grpc_error* error = pull_slice_from_send_message(calld);
256 if (error != GRPC_ERROR_NONE) return error;
257 if (calld->send_message_bytes_read ==
258 calld->send_message_caching_stream->length()) {
259 break;
260 }
261 }
262 return GRPC_ERROR_NONE;
263 }
264
265 // Async callback for ByteStream::Next().
on_send_message_next_done(void * arg,grpc_error * error)266 static void on_send_message_next_done(void* arg, grpc_error* error) {
267 grpc_call_element* elem = static_cast<grpc_call_element*>(arg);
268 call_data* calld = static_cast<call_data*>(elem->call_data);
269 if (error != GRPC_ERROR_NONE) {
270 grpc_transport_stream_op_batch_finish_with_failure(
271 calld->send_message_batch, error, calld->call_combiner);
272 return;
273 }
274 error = pull_slice_from_send_message(calld);
275 if (error != GRPC_ERROR_NONE) {
276 grpc_transport_stream_op_batch_finish_with_failure(
277 calld->send_message_batch, error, calld->call_combiner);
278 return;
279 }
280 // There may or may not be more to read, but we don't care. If we got
281 // here, then we know that all of the data was not available
282 // synchronously, so we were not able to do a cached call. Instead,
283 // we just reset the byte stream and then send down the batch as-is.
284 calld->send_message_caching_stream->Reset();
285 grpc_call_next_op(elem, calld->send_message_batch);
286 }
287
slice_buffer_to_string(grpc_slice_buffer * slice_buffer)288 static char* slice_buffer_to_string(grpc_slice_buffer* slice_buffer) {
289 char* payload_bytes =
290 static_cast<char*>(gpr_malloc(slice_buffer->length + 1));
291 size_t offset = 0;
292 for (size_t i = 0; i < slice_buffer->count; ++i) {
293 memcpy(payload_bytes + offset,
294 GRPC_SLICE_START_PTR(slice_buffer->slices[i]),
295 GRPC_SLICE_LENGTH(slice_buffer->slices[i]));
296 offset += GRPC_SLICE_LENGTH(slice_buffer->slices[i]);
297 }
298 *(payload_bytes + offset) = '\0';
299 return payload_bytes;
300 }
301
302 // Modifies the path entry in the batch's send_initial_metadata to
303 // append the base64-encoded query for a GET request.
update_path_for_get(grpc_call_element * elem,grpc_transport_stream_op_batch * batch)304 static grpc_error* update_path_for_get(grpc_call_element* elem,
305 grpc_transport_stream_op_batch* batch) {
306 call_data* calld = static_cast<call_data*>(elem->call_data);
307 grpc_slice path_slice =
308 GRPC_MDVALUE(batch->payload->send_initial_metadata.send_initial_metadata
309 ->idx.named.path->md);
310 /* sum up individual component's lengths and allocate enough memory to
311 * hold combined path+query */
312 size_t estimated_len = GRPC_SLICE_LENGTH(path_slice);
313 estimated_len++; /* for the '?' */
314 estimated_len += grpc_base64_estimate_encoded_size(
315 batch->payload->send_message.send_message->length(),
316 false /* multi_line */);
317 grpc_core::UnmanagedMemorySlice path_with_query_slice(estimated_len);
318 /* memcopy individual pieces into this slice */
319 char* write_ptr =
320 reinterpret_cast<char*> GRPC_SLICE_START_PTR(path_with_query_slice);
321 char* original_path =
322 reinterpret_cast<char*> GRPC_SLICE_START_PTR(path_slice);
323 memcpy(write_ptr, original_path, GRPC_SLICE_LENGTH(path_slice));
324 write_ptr += GRPC_SLICE_LENGTH(path_slice);
325 *write_ptr++ = '?';
326 char* payload_bytes =
327 slice_buffer_to_string(calld->send_message_cache->cache_buffer());
328 grpc_base64_encode_core(write_ptr, payload_bytes,
329 batch->payload->send_message.send_message->length(),
330 true /* url_safe */, false /* multi_line */);
331 gpr_free(payload_bytes);
332 /* remove trailing unused memory and add trailing 0 to terminate string */
333 char* t = reinterpret_cast<char*> GRPC_SLICE_START_PTR(path_with_query_slice);
334 /* safe to use strlen since base64_encode will always add '\0' */
335 path_with_query_slice =
336 grpc_slice_sub_no_ref(path_with_query_slice, 0, strlen(t));
337 /* substitute previous path with the new path+query */
338 grpc_mdelem mdelem_path_and_query =
339 grpc_mdelem_from_slices(GRPC_MDSTR_PATH, path_with_query_slice);
340 grpc_metadata_batch* b =
341 batch->payload->send_initial_metadata.send_initial_metadata;
342 return grpc_metadata_batch_substitute(b, b->idx.named.path,
343 mdelem_path_and_query);
344 }
345
remove_if_present(grpc_metadata_batch * batch,grpc_metadata_batch_callouts_index idx)346 static void remove_if_present(grpc_metadata_batch* batch,
347 grpc_metadata_batch_callouts_index idx) {
348 if (batch->idx.array[idx] != nullptr) {
349 grpc_metadata_batch_remove(batch, idx);
350 }
351 }
352
http_client_start_transport_stream_op_batch(grpc_call_element * elem,grpc_transport_stream_op_batch * batch)353 static void http_client_start_transport_stream_op_batch(
354 grpc_call_element* elem, grpc_transport_stream_op_batch* batch) {
355 call_data* calld = static_cast<call_data*>(elem->call_data);
356 channel_data* channeld = static_cast<channel_data*>(elem->channel_data);
357 GPR_TIMER_SCOPE("http_client_start_transport_stream_op_batch", 0);
358
359 if (batch->recv_initial_metadata) {
360 /* substitute our callback for the higher callback */
361 calld->recv_initial_metadata =
362 batch->payload->recv_initial_metadata.recv_initial_metadata;
363 calld->original_recv_initial_metadata_ready =
364 batch->payload->recv_initial_metadata.recv_initial_metadata_ready;
365 batch->payload->recv_initial_metadata.recv_initial_metadata_ready =
366 &calld->recv_initial_metadata_ready;
367 }
368
369 if (batch->recv_trailing_metadata) {
370 /* substitute our callback for the higher callback */
371 calld->recv_trailing_metadata =
372 batch->payload->recv_trailing_metadata.recv_trailing_metadata;
373 calld->original_recv_trailing_metadata_ready =
374 batch->payload->recv_trailing_metadata.recv_trailing_metadata_ready;
375 batch->payload->recv_trailing_metadata.recv_trailing_metadata_ready =
376 &calld->recv_trailing_metadata_ready;
377 }
378
379 grpc_error* error = GRPC_ERROR_NONE;
380 bool batch_will_be_handled_asynchronously = false;
381 if (batch->send_initial_metadata) {
382 // Decide which HTTP VERB to use. We use GET if the request is marked
383 // cacheable, and the operation contains both initial metadata and send
384 // message, and the payload is below the size threshold, and all the data
385 // for this request is immediately available.
386 grpc_mdelem method = GRPC_MDELEM_METHOD_POST;
387 if (batch->send_message &&
388 (batch->payload->send_initial_metadata.send_initial_metadata_flags &
389 GRPC_INITIAL_METADATA_CACHEABLE_REQUEST) &&
390 batch->payload->send_message.send_message->length() <
391 channeld->max_payload_size_for_get) {
392 calld->send_message_bytes_read = 0;
393 calld->send_message_cache.Init(
394 std::move(batch->payload->send_message.send_message));
395 calld->send_message_caching_stream.Init(calld->send_message_cache.get());
396 batch->payload->send_message.send_message.reset(
397 calld->send_message_caching_stream.get());
398 calld->original_send_message_on_complete = batch->on_complete;
399 batch->on_complete = &calld->send_message_on_complete;
400 calld->send_message_batch = batch;
401 error = read_all_available_send_message_data(calld);
402 if (error != GRPC_ERROR_NONE) goto done;
403 // If all the data has been read, then we can use GET.
404 if (calld->send_message_bytes_read ==
405 calld->send_message_caching_stream->length()) {
406 method = GRPC_MDELEM_METHOD_GET;
407 error = update_path_for_get(elem, batch);
408 if (error != GRPC_ERROR_NONE) goto done;
409 batch->send_message = false;
410 calld->send_message_caching_stream->Orphan();
411 } else {
412 // Not all data is available. The batch will be sent down
413 // asynchronously in on_send_message_next_done().
414 batch_will_be_handled_asynchronously = true;
415 // Fall back to POST.
416 gpr_log(GPR_DEBUG,
417 "Request is marked Cacheable but not all data is available. "
418 "Falling back to POST");
419 }
420 } else if (batch->payload->send_initial_metadata
421 .send_initial_metadata_flags &
422 GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST) {
423 method = GRPC_MDELEM_METHOD_PUT;
424 }
425
426 remove_if_present(
427 batch->payload->send_initial_metadata.send_initial_metadata,
428 GRPC_BATCH_METHOD);
429 remove_if_present(
430 batch->payload->send_initial_metadata.send_initial_metadata,
431 GRPC_BATCH_SCHEME);
432 remove_if_present(
433 batch->payload->send_initial_metadata.send_initial_metadata,
434 GRPC_BATCH_TE);
435 remove_if_present(
436 batch->payload->send_initial_metadata.send_initial_metadata,
437 GRPC_BATCH_CONTENT_TYPE);
438 remove_if_present(
439 batch->payload->send_initial_metadata.send_initial_metadata,
440 GRPC_BATCH_USER_AGENT);
441
442 /* Send : prefixed headers, which have to be before any application
443 layer headers. */
444 error = grpc_metadata_batch_add_head(
445 batch->payload->send_initial_metadata.send_initial_metadata,
446 &calld->method, method, GRPC_BATCH_METHOD);
447 if (error != GRPC_ERROR_NONE) goto done;
448 error = grpc_metadata_batch_add_head(
449 batch->payload->send_initial_metadata.send_initial_metadata,
450 &calld->scheme, channeld->static_scheme, GRPC_BATCH_SCHEME);
451 if (error != GRPC_ERROR_NONE) goto done;
452 error = grpc_metadata_batch_add_tail(
453 batch->payload->send_initial_metadata.send_initial_metadata,
454 &calld->te_trailers, GRPC_MDELEM_TE_TRAILERS, GRPC_BATCH_TE);
455 if (error != GRPC_ERROR_NONE) goto done;
456 error = grpc_metadata_batch_add_tail(
457 batch->payload->send_initial_metadata.send_initial_metadata,
458 &calld->content_type, GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC,
459 GRPC_BATCH_CONTENT_TYPE);
460 if (error != GRPC_ERROR_NONE) goto done;
461 error = grpc_metadata_batch_add_tail(
462 batch->payload->send_initial_metadata.send_initial_metadata,
463 &calld->user_agent, GRPC_MDELEM_REF(channeld->user_agent),
464 GRPC_BATCH_USER_AGENT);
465 if (error != GRPC_ERROR_NONE) goto done;
466 }
467
468 done:
469 if (error != GRPC_ERROR_NONE) {
470 grpc_transport_stream_op_batch_finish_with_failure(
471 calld->send_message_batch, error, calld->call_combiner);
472 } else if (!batch_will_be_handled_asynchronously) {
473 grpc_call_next_op(elem, batch);
474 }
475 }
476
477 /* Constructor for call_data */
http_client_init_call_elem(grpc_call_element * elem,const grpc_call_element_args * args)478 static grpc_error* http_client_init_call_elem(
479 grpc_call_element* elem, const grpc_call_element_args* args) {
480 new (elem->call_data) call_data(elem, *args);
481 return GRPC_ERROR_NONE;
482 }
483
484 /* Destructor for call_data */
http_client_destroy_call_elem(grpc_call_element * elem,const grpc_call_final_info *,grpc_closure *)485 static void http_client_destroy_call_elem(
486 grpc_call_element* elem, const grpc_call_final_info* /*final_info*/,
487 grpc_closure* /*ignored*/) {
488 call_data* calld = static_cast<call_data*>(elem->call_data);
489 calld->~call_data();
490 }
491
scheme_from_args(const grpc_channel_args * args)492 static grpc_mdelem scheme_from_args(const grpc_channel_args* args) {
493 unsigned i;
494 size_t j;
495 grpc_mdelem valid_schemes[] = {GRPC_MDELEM_SCHEME_HTTP,
496 GRPC_MDELEM_SCHEME_HTTPS};
497 if (args != nullptr) {
498 for (i = 0; i < args->num_args; ++i) {
499 if (args->args[i].type == GRPC_ARG_STRING &&
500 strcmp(args->args[i].key, GRPC_ARG_HTTP2_SCHEME) == 0) {
501 for (j = 0; j < GPR_ARRAY_SIZE(valid_schemes); j++) {
502 if (0 == grpc_slice_str_cmp(GRPC_MDVALUE(valid_schemes[j]),
503 args->args[i].value.string)) {
504 return valid_schemes[j];
505 }
506 }
507 }
508 }
509 }
510 return GRPC_MDELEM_SCHEME_HTTP;
511 }
512
max_payload_size_from_args(const grpc_channel_args * args)513 static size_t max_payload_size_from_args(const grpc_channel_args* args) {
514 if (args != nullptr) {
515 for (size_t i = 0; i < args->num_args; ++i) {
516 if (0 == strcmp(args->args[i].key, GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET)) {
517 if (args->args[i].type != GRPC_ARG_INTEGER) {
518 gpr_log(GPR_ERROR, "%s: must be an integer",
519 GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET);
520 } else {
521 return static_cast<size_t>(args->args[i].value.integer);
522 }
523 }
524 }
525 }
526 return kMaxPayloadSizeForGet;
527 }
528
user_agent_from_args(const grpc_channel_args * args,const char * transport_name)529 static grpc_core::ManagedMemorySlice user_agent_from_args(
530 const grpc_channel_args* args, const char* transport_name) {
531 std::vector<std::string> user_agent_fields;
532
533 for (size_t i = 0; args && i < args->num_args; i++) {
534 if (0 == strcmp(args->args[i].key, GRPC_ARG_PRIMARY_USER_AGENT_STRING)) {
535 if (args->args[i].type != GRPC_ARG_STRING) {
536 gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
537 GRPC_ARG_PRIMARY_USER_AGENT_STRING);
538 } else {
539 user_agent_fields.push_back(args->args[i].value.string);
540 }
541 }
542 }
543
544 user_agent_fields.push_back(
545 absl::StrFormat("grpc-c/%s (%s; %s)", grpc_version_string(),
546 GPR_PLATFORM_STRING, transport_name));
547
548 for (size_t i = 0; args && i < args->num_args; i++) {
549 if (0 == strcmp(args->args[i].key, GRPC_ARG_SECONDARY_USER_AGENT_STRING)) {
550 if (args->args[i].type != GRPC_ARG_STRING) {
551 gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
552 GRPC_ARG_SECONDARY_USER_AGENT_STRING);
553 } else {
554 user_agent_fields.push_back(args->args[i].value.string);
555 }
556 }
557 }
558
559 std::string user_agent_string = absl::StrJoin(user_agent_fields, " ");
560 return grpc_core::ManagedMemorySlice(user_agent_string.c_str());
561 }
562
563 /* Constructor for channel_data */
http_client_init_channel_elem(grpc_channel_element * elem,grpc_channel_element_args * args)564 static grpc_error* http_client_init_channel_elem(
565 grpc_channel_element* elem, grpc_channel_element_args* args) {
566 channel_data* chand = static_cast<channel_data*>(elem->channel_data);
567 GPR_ASSERT(!args->is_last);
568 GPR_ASSERT(args->optional_transport != nullptr);
569 chand->static_scheme = scheme_from_args(args->channel_args);
570 chand->max_payload_size_for_get =
571 max_payload_size_from_args(args->channel_args);
572 chand->user_agent = grpc_mdelem_from_slices(
573 GRPC_MDSTR_USER_AGENT,
574 user_agent_from_args(args->channel_args,
575 args->optional_transport->vtable->name));
576 return GRPC_ERROR_NONE;
577 }
578
579 /* Destructor for channel data */
http_client_destroy_channel_elem(grpc_channel_element * elem)580 static void http_client_destroy_channel_elem(grpc_channel_element* elem) {
581 channel_data* chand = static_cast<channel_data*>(elem->channel_data);
582 GRPC_MDELEM_UNREF(chand->user_agent);
583 }
584
585 const grpc_channel_filter grpc_http_client_filter = {
586 http_client_start_transport_stream_op_batch,
587 grpc_channel_next_op,
588 sizeof(call_data),
589 http_client_init_call_elem,
590 grpc_call_stack_ignore_set_pollset_or_pollset_set,
591 http_client_destroy_call_elem,
592 sizeof(channel_data),
593 http_client_init_channel_elem,
594 http_client_destroy_channel_elem,
595 grpc_channel_next_get_info,
596 "http-client"};
597