diff options
Diffstat (limited to 'src/core/ext/filters/http/client/http_client_filter.c')
| -rw-r--r-- | src/core/ext/filters/http/client/http_client_filter.c | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/src/core/ext/filters/http/client/http_client_filter.c b/src/core/ext/filters/http/client/http_client_filter.c new file mode 100644 index 0000000000..b896c7e7bb --- /dev/null +++ b/src/core/ext/filters/http/client/http_client_filter.c @@ -0,0 +1,601 @@ +/* + * Copyright 2015, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include "src/core/ext/filters/http/client/http_client_filter.h" +#include <grpc/support/alloc.h> +#include <grpc/support/log.h> +#include <grpc/support/string_util.h> +#include <string.h> +#include "src/core/lib/profiling/timers.h" +#include "src/core/lib/slice/b64.h" +#include "src/core/lib/slice/percent_encoding.h" +#include "src/core/lib/slice/slice_internal.h" +#include "src/core/lib/slice/slice_string_helpers.h" +#include "src/core/lib/support/string.h" +#include "src/core/lib/transport/static_metadata.h" +#include "src/core/lib/transport/transport_impl.h" + +#define EXPECTED_CONTENT_TYPE "application/grpc" +#define EXPECTED_CONTENT_TYPE_LENGTH sizeof(EXPECTED_CONTENT_TYPE) - 1 + +/* default maximum size of payload eligable for GET request */ +static const size_t kMaxPayloadSizeForGet = 2048; + +typedef struct call_data { + grpc_linked_mdelem method; + grpc_linked_mdelem scheme; + grpc_linked_mdelem authority; + grpc_linked_mdelem te_trailers; + grpc_linked_mdelem content_type; + grpc_linked_mdelem user_agent; + + grpc_metadata_batch *recv_initial_metadata; + grpc_metadata_batch *recv_trailing_metadata; + uint8_t *payload_bytes; + + /* Vars to read data off of send_message */ + grpc_transport_stream_op_batch *send_op; + uint32_t send_length; + uint32_t send_flags; + grpc_slice incoming_slice; + grpc_slice_buffer_stream replacement_stream; + grpc_slice_buffer slices; + /* flag that indicates that all slices of send_messages aren't availble */ + bool send_message_blocked; + + /** Closure to call when finished with the hc_on_recv hook */ + grpc_closure *on_done_recv_initial_metadata; + grpc_closure *on_done_recv_trailing_metadata; + grpc_closure *on_complete; + grpc_closure *post_send; + + /** Receive closures are chained: we inject this closure as the on_done_recv + up-call on transport_op, and remember to call our on_done_recv member + after handling it. */ + grpc_closure hc_on_recv_initial_metadata; + grpc_closure hc_on_recv_trailing_metadata; + grpc_closure hc_on_complete; + grpc_closure got_slice; + grpc_closure send_done; +} call_data; + +typedef struct channel_data { + grpc_mdelem static_scheme; + grpc_mdelem user_agent; + size_t max_payload_size_for_get; +} channel_data; + +static grpc_error *client_filter_incoming_metadata(grpc_exec_ctx *exec_ctx, + grpc_call_element *elem, + grpc_metadata_batch *b) { + if (b->idx.named.status != NULL) { + if (grpc_mdelem_eq(b->idx.named.status->md, GRPC_MDELEM_STATUS_200)) { + grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.status); + } else { + char *val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.status->md), + GPR_DUMP_ASCII); + char *msg; + gpr_asprintf(&msg, "Received http2 header with status: %s", val); + grpc_error *e = grpc_error_set_str( + grpc_error_set_int( + grpc_error_set_str( + GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "Received http2 :status header with non-200 OK status"), + GRPC_ERROR_STR_VALUE, grpc_slice_from_copied_string(val)), + GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_CANCELLED), + GRPC_ERROR_STR_GRPC_MESSAGE, grpc_slice_from_copied_string(msg)); + gpr_free(val); + gpr_free(msg); + return e; + } + } + + if (b->idx.named.grpc_message != NULL) { + grpc_slice pct_decoded_msg = grpc_permissive_percent_decode_slice( + GRPC_MDVALUE(b->idx.named.grpc_message->md)); + if (grpc_slice_is_equivalent(pct_decoded_msg, + GRPC_MDVALUE(b->idx.named.grpc_message->md))) { + grpc_slice_unref_internal(exec_ctx, pct_decoded_msg); + } else { + grpc_metadata_batch_set_value(exec_ctx, b->idx.named.grpc_message, + pct_decoded_msg); + } + } + + if (b->idx.named.content_type != NULL) { + if (!grpc_mdelem_eq(b->idx.named.content_type->md, + GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC)) { + if (grpc_slice_buf_start_eq(GRPC_MDVALUE(b->idx.named.content_type->md), + EXPECTED_CONTENT_TYPE, + EXPECTED_CONTENT_TYPE_LENGTH) && + (GRPC_SLICE_START_PTR(GRPC_MDVALUE( + b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] == + '+' || + GRPC_SLICE_START_PTR(GRPC_MDVALUE( + b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] == + ';')) { + /* Although the C implementation doesn't (currently) generate them, + any custom +-suffix is explicitly valid. */ + /* TODO(klempner): We should consider preallocating common values such + as +proto or +json, or at least stashing them if we see them. */ + /* TODO(klempner): Should we be surfacing this to application code? */ + } else { + /* TODO(klempner): We're currently allowing this, but we shouldn't + see it without a proxy so log for now. */ + char *val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.content_type->md), + GPR_DUMP_ASCII); + gpr_log(GPR_INFO, "Unexpected content-type '%s'", val); + gpr_free(val); + } + } + grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.content_type); + } + + return GRPC_ERROR_NONE; +} + +static void hc_on_recv_initial_metadata(grpc_exec_ctx *exec_ctx, + void *user_data, grpc_error *error) { + grpc_call_element *elem = user_data; + call_data *calld = elem->call_data; + if (error == GRPC_ERROR_NONE) { + error = client_filter_incoming_metadata(exec_ctx, elem, + calld->recv_initial_metadata); + } else { + GRPC_ERROR_REF(error); + } + grpc_closure_run(exec_ctx, calld->on_done_recv_initial_metadata, error); +} + +static void hc_on_recv_trailing_metadata(grpc_exec_ctx *exec_ctx, + void *user_data, grpc_error *error) { + grpc_call_element *elem = user_data; + call_data *calld = elem->call_data; + if (error == GRPC_ERROR_NONE) { + error = client_filter_incoming_metadata(exec_ctx, elem, + calld->recv_trailing_metadata); + } else { + GRPC_ERROR_REF(error); + } + grpc_closure_run(exec_ctx, calld->on_done_recv_trailing_metadata, error); +} + +static void hc_on_complete(grpc_exec_ctx *exec_ctx, void *user_data, + grpc_error *error) { + grpc_call_element *elem = user_data; + call_data *calld = elem->call_data; + if (calld->payload_bytes) { + gpr_free(calld->payload_bytes); + calld->payload_bytes = NULL; + } + calld->on_complete->cb(exec_ctx, calld->on_complete->cb_arg, error); +} + +static void send_done(grpc_exec_ctx *exec_ctx, void *elemp, grpc_error *error) { + grpc_call_element *elem = elemp; + call_data *calld = elem->call_data; + grpc_slice_buffer_reset_and_unref_internal(exec_ctx, &calld->slices); + calld->post_send->cb(exec_ctx, calld->post_send->cb_arg, error); +} + +static void remove_if_present(grpc_exec_ctx *exec_ctx, + grpc_metadata_batch *batch, + grpc_metadata_batch_callouts_index idx) { + if (batch->idx.array[idx] != NULL) { + grpc_metadata_batch_remove(exec_ctx, batch, batch->idx.array[idx]); + } +} + +static void continue_send_message(grpc_exec_ctx *exec_ctx, + grpc_call_element *elem) { + call_data *calld = elem->call_data; + uint8_t *wrptr = calld->payload_bytes; + while (grpc_byte_stream_next( + exec_ctx, calld->send_op->payload->send_message.send_message, + &calld->incoming_slice, ~(size_t)0, &calld->got_slice)) { + if (GRPC_SLICE_LENGTH(calld->incoming_slice) > 0) { + memcpy(wrptr, GRPC_SLICE_START_PTR(calld->incoming_slice), + GRPC_SLICE_LENGTH(calld->incoming_slice)); + } + wrptr += GRPC_SLICE_LENGTH(calld->incoming_slice); + grpc_slice_buffer_add(&calld->slices, calld->incoming_slice); + if (calld->send_length == calld->slices.length) { + calld->send_message_blocked = false; + break; + } + } +} + +static void got_slice(grpc_exec_ctx *exec_ctx, void *elemp, grpc_error *error) { + grpc_call_element *elem = elemp; + call_data *calld = elem->call_data; + calld->send_message_blocked = false; + grpc_slice_buffer_add(&calld->slices, calld->incoming_slice); + if (calld->send_length == calld->slices.length) { + /* Pass down the original send_message op that was blocked.*/ + grpc_slice_buffer_stream_init(&calld->replacement_stream, &calld->slices, + calld->send_flags); + calld->send_op->payload->send_message.send_message = + &calld->replacement_stream.base; + calld->post_send = calld->send_op->on_complete; + calld->send_op->on_complete = &calld->send_done; + grpc_call_next_op(exec_ctx, elem, calld->send_op); + } else { + continue_send_message(exec_ctx, elem); + } +} + +static grpc_error *hc_mutate_op(grpc_exec_ctx *exec_ctx, + grpc_call_element *elem, + grpc_transport_stream_op_batch *op) { + /* grab pointers to our data from the call element */ + call_data *calld = elem->call_data; + channel_data *channeld = elem->channel_data; + grpc_error *error; + + if (op->send_initial_metadata) { + /* Decide which HTTP VERB to use. We use GET if the request is marked + cacheable, and the operation contains both initial metadata and send + message, and the payload is below the size threshold, and all the data + for this request is immediately available. */ + grpc_mdelem method = GRPC_MDELEM_METHOD_POST; + if (op->send_message && + (op->payload->send_initial_metadata.send_initial_metadata_flags & + GRPC_INITIAL_METADATA_CACHEABLE_REQUEST) && + op->payload->send_message.send_message->length < + channeld->max_payload_size_for_get) { + method = GRPC_MDELEM_METHOD_GET; + /* The following write to calld->send_message_blocked isn't racy with + reads in hc_start_transport_op (which deals with SEND_MESSAGE ops) because + being here means ops->send_message is not NULL, which is primarily + guarding the read there. */ + calld->send_message_blocked = true; + } else if (op->payload->send_initial_metadata.send_initial_metadata_flags & + GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST) { + method = GRPC_MDELEM_METHOD_PUT; + } + + /* Attempt to read the data from send_message and create a header field. */ + if (grpc_mdelem_eq(method, GRPC_MDELEM_METHOD_GET)) { + /* allocate memory to hold the entire payload */ + calld->payload_bytes = + gpr_malloc(op->payload->send_message.send_message->length); + + /* read slices of send_message and copy into payload_bytes */ + calld->send_op = op; + calld->send_length = op->payload->send_message.send_message->length; + calld->send_flags = op->payload->send_message.send_message->flags; + continue_send_message(exec_ctx, elem); + + if (calld->send_message_blocked == false) { + /* when all the send_message data is available, then modify the path + * MDELEM by appending base64 encoded query to the path */ + const int k_url_safe = 1; + const int k_multi_line = 0; + const unsigned char k_query_separator = '?'; + + grpc_slice path_slice = + GRPC_MDVALUE(op->payload->send_initial_metadata + .send_initial_metadata->idx.named.path->md); + /* sum up individual component's lengths and allocate enough memory to + * hold combined path+query */ + size_t estimated_len = GRPC_SLICE_LENGTH(path_slice); + estimated_len++; /* for the '?' */ + estimated_len += grpc_base64_estimate_encoded_size( + op->payload->send_message.send_message->length, k_url_safe, + k_multi_line); + estimated_len += 1; /* for the trailing 0 */ + grpc_slice path_with_query_slice = grpc_slice_malloc(estimated_len); + + /* memcopy individual pieces into this slice */ + uint8_t *write_ptr = + (uint8_t *)GRPC_SLICE_START_PTR(path_with_query_slice); + uint8_t *original_path = (uint8_t *)GRPC_SLICE_START_PTR(path_slice); + memcpy(write_ptr, original_path, GRPC_SLICE_LENGTH(path_slice)); + write_ptr += GRPC_SLICE_LENGTH(path_slice); + + *write_ptr = k_query_separator; + write_ptr++; /* for the '?' */ + + grpc_base64_encode_core((char *)write_ptr, calld->payload_bytes, + op->payload->send_message.send_message->length, + k_url_safe, k_multi_line); + + /* remove trailing unused memory and add trailing 0 to terminate string + */ + char *t = (char *)GRPC_SLICE_START_PTR(path_with_query_slice); + /* safe to use strlen since base64_encode will always add '\0' */ + path_with_query_slice = + grpc_slice_sub(path_with_query_slice, 0, strlen(t)); + + /* substitute previous path with the new path+query */ + grpc_mdelem mdelem_path_and_query = grpc_mdelem_from_slices( + exec_ctx, GRPC_MDSTR_PATH, path_with_query_slice); + grpc_metadata_batch *b = + op->payload->send_initial_metadata.send_initial_metadata; + error = grpc_metadata_batch_substitute(exec_ctx, b, b->idx.named.path, + mdelem_path_and_query); + if (error != GRPC_ERROR_NONE) return error; + + calld->on_complete = op->on_complete; + op->on_complete = &calld->hc_on_complete; + op->send_message = false; + grpc_slice_unref_internal(exec_ctx, path_with_query_slice); + } else { + /* Not all data is available. Fall back to POST. */ + gpr_log(GPR_DEBUG, + "Request is marked Cacheable but not all data is available.\ + Falling back to POST"); + method = GRPC_MDELEM_METHOD_POST; + } + } + + remove_if_present(exec_ctx, + op->payload->send_initial_metadata.send_initial_metadata, + GRPC_BATCH_METHOD); + remove_if_present(exec_ctx, + op->payload->send_initial_metadata.send_initial_metadata, + GRPC_BATCH_SCHEME); + remove_if_present(exec_ctx, + op->payload->send_initial_metadata.send_initial_metadata, + GRPC_BATCH_TE); + remove_if_present(exec_ctx, + op->payload->send_initial_metadata.send_initial_metadata, + GRPC_BATCH_CONTENT_TYPE); + remove_if_present(exec_ctx, + op->payload->send_initial_metadata.send_initial_metadata, + GRPC_BATCH_USER_AGENT); + + /* Send : prefixed headers, which have to be before any application + layer headers. */ + error = grpc_metadata_batch_add_head( + exec_ctx, op->payload->send_initial_metadata.send_initial_metadata, + &calld->method, method); + if (error != GRPC_ERROR_NONE) return error; + error = grpc_metadata_batch_add_head( + exec_ctx, op->payload->send_initial_metadata.send_initial_metadata, + &calld->scheme, channeld->static_scheme); + if (error != GRPC_ERROR_NONE) return error; + error = grpc_metadata_batch_add_tail( + exec_ctx, op->payload->send_initial_metadata.send_initial_metadata, + &calld->te_trailers, GRPC_MDELEM_TE_TRAILERS); + if (error != GRPC_ERROR_NONE) return error; + error = grpc_metadata_batch_add_tail( + exec_ctx, op->payload->send_initial_metadata.send_initial_metadata, + &calld->content_type, GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC); + if (error != GRPC_ERROR_NONE) return error; + error = grpc_metadata_batch_add_tail( + exec_ctx, op->payload->send_initial_metadata.send_initial_metadata, + &calld->user_agent, GRPC_MDELEM_REF(channeld->user_agent)); + if (error != GRPC_ERROR_NONE) return error; + } + + if (op->recv_initial_metadata) { + /* substitute our callback for the higher callback */ + calld->recv_initial_metadata = + op->payload->recv_initial_metadata.recv_initial_metadata; + calld->on_done_recv_initial_metadata = + op->payload->recv_initial_metadata.recv_initial_metadata_ready; + op->payload->recv_initial_metadata.recv_initial_metadata_ready = + &calld->hc_on_recv_initial_metadata; + } + + if (op->recv_trailing_metadata) { + /* substitute our callback for the higher callback */ + calld->recv_trailing_metadata = + op->payload->recv_trailing_metadata.recv_trailing_metadata; + calld->on_done_recv_trailing_metadata = op->on_complete; + op->on_complete = &calld->hc_on_recv_trailing_metadata; + } + + return GRPC_ERROR_NONE; +} + +static void hc_start_transport_op(grpc_exec_ctx *exec_ctx, + grpc_call_element *elem, + grpc_transport_stream_op_batch *op) { + GPR_TIMER_BEGIN("hc_start_transport_op", 0); + GRPC_CALL_LOG_OP(GPR_INFO, elem, op); + grpc_error *error = hc_mutate_op(exec_ctx, elem, op); + if (error != GRPC_ERROR_NONE) { + grpc_transport_stream_op_batch_finish_with_failure(exec_ctx, op, error); + } else { + call_data *calld = elem->call_data; + if (op->send_message && calld->send_message_blocked) { + /* Don't forward the op. send_message contains slices that aren't ready + yet. The call will be forwarded by the op_complete of slice read call. + */ + } else { + grpc_call_next_op(exec_ctx, elem, op); + } + } + GPR_TIMER_END("hc_start_transport_op", 0); +} + +/* Constructor for call_data */ +static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx, + grpc_call_element *elem, + const grpc_call_element_args *args) { + call_data *calld = elem->call_data; + calld->on_done_recv_initial_metadata = NULL; + calld->on_done_recv_trailing_metadata = NULL; + calld->on_complete = NULL; + calld->payload_bytes = NULL; + calld->send_message_blocked = false; + grpc_slice_buffer_init(&calld->slices); + grpc_closure_init(&calld->hc_on_recv_initial_metadata, + hc_on_recv_initial_metadata, elem, + grpc_schedule_on_exec_ctx); + grpc_closure_init(&calld->hc_on_recv_trailing_metadata, + hc_on_recv_trailing_metadata, elem, + grpc_schedule_on_exec_ctx); + grpc_closure_init(&calld->hc_on_complete, hc_on_complete, elem, + grpc_schedule_on_exec_ctx); + grpc_closure_init(&calld->got_slice, got_slice, elem, + grpc_schedule_on_exec_ctx); + grpc_closure_init(&calld->send_done, send_done, elem, + grpc_schedule_on_exec_ctx); + return GRPC_ERROR_NONE; +} + +/* Destructor for call_data */ +static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem, + const grpc_call_final_info *final_info, + grpc_closure *ignored) { + call_data *calld = elem->call_data; + grpc_slice_buffer_destroy_internal(exec_ctx, &calld->slices); +} + +static grpc_mdelem scheme_from_args(const grpc_channel_args *args) { + unsigned i; + size_t j; + grpc_mdelem valid_schemes[] = {GRPC_MDELEM_SCHEME_HTTP, + GRPC_MDELEM_SCHEME_HTTPS}; + if (args != NULL) { + for (i = 0; i < args->num_args; ++i) { + if (args->args[i].type == GRPC_ARG_STRING && + strcmp(args->args[i].key, GRPC_ARG_HTTP2_SCHEME) == 0) { + for (j = 0; j < GPR_ARRAY_SIZE(valid_schemes); j++) { + if (0 == grpc_slice_str_cmp(GRPC_MDVALUE(valid_schemes[j]), + args->args[i].value.string)) { + return valid_schemes[j]; + } + } + } + } + } + return GRPC_MDELEM_SCHEME_HTTP; +} + +static size_t max_payload_size_from_args(const grpc_channel_args *args) { + if (args != NULL) { + for (size_t i = 0; i < args->num_args; ++i) { + if (0 == strcmp(args->args[i].key, GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET)) { + if (args->args[i].type != GRPC_ARG_INTEGER) { + gpr_log(GPR_ERROR, "%s: must be an integer", + GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET); + } else { + return (size_t)args->args[i].value.integer; + } + } + } + } + return kMaxPayloadSizeForGet; +} + +static grpc_slice user_agent_from_args(const grpc_channel_args *args, + const char *transport_name) { + gpr_strvec v; + size_t i; + int is_first = 1; + char *tmp; + grpc_slice result; + + gpr_strvec_init(&v); + + for (i = 0; args && i < args->num_args; i++) { + if (0 == strcmp(args->args[i].key, GRPC_ARG_PRIMARY_USER_AGENT_STRING)) { + if (args->args[i].type != GRPC_ARG_STRING) { + gpr_log(GPR_ERROR, "Channel argument '%s' should be a string", + GRPC_ARG_PRIMARY_USER_AGENT_STRING); + } else { + if (!is_first) gpr_strvec_add(&v, gpr_strdup(" ")); + is_first = 0; + gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string)); + } + } + } + + gpr_asprintf(&tmp, "%sgrpc-c/%s (%s; %s; %s)", is_first ? "" : " ", + grpc_version_string(), GPR_PLATFORM_STRING, transport_name, + grpc_g_stands_for()); + is_first = 0; + gpr_strvec_add(&v, tmp); + + for (i = 0; args && i < args->num_args; i++) { + if (0 == strcmp(args->args[i].key, GRPC_ARG_SECONDARY_USER_AGENT_STRING)) { + if (args->args[i].type != GRPC_ARG_STRING) { + gpr_log(GPR_ERROR, "Channel argument '%s' should be a string", + GRPC_ARG_SECONDARY_USER_AGENT_STRING); + } else { + if (!is_first) gpr_strvec_add(&v, gpr_strdup(" ")); + is_first = 0; + gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string)); + } + } + } + + tmp = gpr_strvec_flatten(&v, NULL); + gpr_strvec_destroy(&v); + result = grpc_slice_intern(grpc_slice_from_static_string(tmp)); + gpr_free(tmp); + + return result; +} + +/* Constructor for channel_data */ +static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx, + grpc_channel_element *elem, + grpc_channel_element_args *args) { + channel_data *chand = elem->channel_data; + GPR_ASSERT(!args->is_last); + GPR_ASSERT(args->optional_transport != NULL); + chand->static_scheme = scheme_from_args(args->channel_args); + chand->max_payload_size_for_get = + max_payload_size_from_args(args->channel_args); + chand->user_agent = grpc_mdelem_from_slices( + exec_ctx, GRPC_MDSTR_USER_AGENT, + user_agent_from_args(args->channel_args, + args->optional_transport->vtable->name)); + return GRPC_ERROR_NONE; +} + +/* Destructor for channel data */ +static void destroy_channel_elem(grpc_exec_ctx *exec_ctx, + grpc_channel_element *elem) { + channel_data *chand = elem->channel_data; + GRPC_MDELEM_UNREF(exec_ctx, chand->user_agent); +} + +const grpc_channel_filter grpc_http_client_filter = { + hc_start_transport_op, + grpc_channel_next_op, + sizeof(call_data), + init_call_elem, + grpc_call_stack_ignore_set_pollset_or_pollset_set, + destroy_call_elem, + sizeof(channel_data), + init_channel_elem, + destroy_channel_elem, + grpc_call_next_get_peer, + grpc_channel_next_get_info, + "http-client"}; |