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/*
*
* Copyright 2015 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include "src/core/ext/transport/chttp2/client/chttp2_connector.h"
#include <grpc/grpc.h>
#include <string.h>
#include <grpc/slice_buffer.h>
#include <grpc/support/alloc.h>
#include <grpc/support/string_util.h>
#include "src/core/ext/filters/client_channel/connector.h"
#include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
#include "src/core/ext/filters/client_channel/subchannel.h"
#include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/channel/handshaker.h"
#include "src/core/lib/channel/handshaker_registry.h"
#include "src/core/lib/iomgr/tcp_client.h"
#include "src/core/lib/slice/slice_internal.h"
typedef struct {
grpc_connector base;
gpr_mu mu;
gpr_refcount refs;
bool shutdown;
bool connecting;
grpc_closure* notify;
grpc_connect_in_args args;
grpc_connect_out_args* result;
grpc_endpoint* endpoint; // Non-NULL until handshaking starts.
grpc_closure connected;
grpc_handshake_manager* handshake_mgr;
} chttp2_connector;
static void chttp2_connector_ref(grpc_connector* con) {
chttp2_connector* c = (chttp2_connector*)con;
gpr_ref(&c->refs);
}
static void chttp2_connector_unref(grpc_exec_ctx* exec_ctx,
grpc_connector* con) {
chttp2_connector* c = (chttp2_connector*)con;
if (gpr_unref(&c->refs)) {
gpr_mu_destroy(&c->mu);
// If handshaking is not yet in progress, destroy the endpoint.
// Otherwise, the handshaker will do this for us.
if (c->endpoint != nullptr) grpc_endpoint_destroy(exec_ctx, c->endpoint);
gpr_free(c);
}
}
static void chttp2_connector_shutdown(grpc_exec_ctx* exec_ctx,
grpc_connector* con, grpc_error* why) {
chttp2_connector* c = (chttp2_connector*)con;
gpr_mu_lock(&c->mu);
c->shutdown = true;
if (c->handshake_mgr != nullptr) {
grpc_handshake_manager_shutdown(exec_ctx, c->handshake_mgr,
GRPC_ERROR_REF(why));
}
// If handshaking is not yet in progress, shutdown the endpoint.
// Otherwise, the handshaker will do this for us.
if (!c->connecting && c->endpoint != nullptr) {
grpc_endpoint_shutdown(exec_ctx, c->endpoint, GRPC_ERROR_REF(why));
}
gpr_mu_unlock(&c->mu);
GRPC_ERROR_UNREF(why);
}
static void on_handshake_done(grpc_exec_ctx* exec_ctx, void* arg,
grpc_error* error) {
grpc_handshaker_args* args = (grpc_handshaker_args*)arg;
chttp2_connector* c = (chttp2_connector*)args->user_data;
gpr_mu_lock(&c->mu);
if (error != GRPC_ERROR_NONE || c->shutdown) {
if (error == GRPC_ERROR_NONE) {
error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("connector shutdown");
// We were shut down after handshaking completed successfully, so
// destroy the endpoint here.
// TODO(ctiller): It is currently necessary to shutdown endpoints
// before destroying them, even if we know that there are no
// pending read/write callbacks. This should be fixed, at which
// point this can be removed.
grpc_endpoint_shutdown(exec_ctx, args->endpoint, GRPC_ERROR_REF(error));
grpc_endpoint_destroy(exec_ctx, args->endpoint);
grpc_channel_args_destroy(exec_ctx, args->args);
grpc_slice_buffer_destroy_internal(exec_ctx, args->read_buffer);
gpr_free(args->read_buffer);
} else {
error = GRPC_ERROR_REF(error);
}
memset(c->result, 0, sizeof(*c->result));
} else {
grpc_endpoint_delete_from_pollset_set(exec_ctx, args->endpoint,
c->args.interested_parties);
c->result->transport = grpc_create_chttp2_transport(exec_ctx, args->args,
args->endpoint, true);
GPR_ASSERT(c->result->transport);
// TODO(roth): We ideally want to wait until we receive HTTP/2
// settings from the server before we consider the connection
// established. If that doesn't happen before the connection
// timeout expires, then we should consider the connection attempt a
// failure and feed that information back into the backoff code.
// We could pass a notify_on_receive_settings callback to
// grpc_chttp2_transport_start_reading() to let us know when
// settings are received, but we would need to figure out how to use
// that information here.
//
// Unfortunately, we don't currently have a way to split apart the two
// effects of scheduling c->notify: we start sending RPCs immediately
// (which we want to do) and we consider the connection attempt successful
// (which we don't want to do until we get the notify_on_receive_settings
// callback from the transport). If we could split those things
// apart, then we could start sending RPCs but then wait for our
// timeout before deciding if the connection attempt is successful.
// If the attempt is not successful, then we would tear down the
// transport and feed the failure back into the backoff code.
//
// In addition, even if we did that, we would probably not want to do
// so until after transparent retries is implemented. Otherwise, any
// RPC that we attempt to send on the connection before the timeout
// would fail instead of being retried on a subsequent attempt.
grpc_chttp2_transport_start_reading(exec_ctx, c->result->transport,
args->read_buffer, nullptr);
c->result->channel_args = args->args;
}
grpc_closure* notify = c->notify;
c->notify = nullptr;
GRPC_CLOSURE_SCHED(exec_ctx, notify, error);
grpc_handshake_manager_destroy(exec_ctx, c->handshake_mgr);
c->handshake_mgr = nullptr;
gpr_mu_unlock(&c->mu);
chttp2_connector_unref(exec_ctx, (grpc_connector*)c);
}
static void start_handshake_locked(grpc_exec_ctx* exec_ctx,
chttp2_connector* c) {
c->handshake_mgr = grpc_handshake_manager_create();
grpc_handshakers_add(exec_ctx, HANDSHAKER_CLIENT, c->args.channel_args,
c->handshake_mgr);
grpc_endpoint_add_to_pollset_set(exec_ctx, c->endpoint,
c->args.interested_parties);
grpc_handshake_manager_do_handshake(
exec_ctx, c->handshake_mgr, c->args.interested_parties, c->endpoint,
c->args.channel_args, c->args.deadline, nullptr /* acceptor */,
on_handshake_done, c);
c->endpoint = nullptr; // Endpoint handed off to handshake manager.
}
static void connected(grpc_exec_ctx* exec_ctx, void* arg, grpc_error* error) {
chttp2_connector* c = (chttp2_connector*)arg;
gpr_mu_lock(&c->mu);
GPR_ASSERT(c->connecting);
c->connecting = false;
if (error != GRPC_ERROR_NONE || c->shutdown) {
if (error == GRPC_ERROR_NONE) {
error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("connector shutdown");
} else {
error = GRPC_ERROR_REF(error);
}
memset(c->result, 0, sizeof(*c->result));
grpc_closure* notify = c->notify;
c->notify = nullptr;
GRPC_CLOSURE_SCHED(exec_ctx, notify, error);
if (c->endpoint != nullptr) {
grpc_endpoint_shutdown(exec_ctx, c->endpoint, GRPC_ERROR_REF(error));
}
gpr_mu_unlock(&c->mu);
chttp2_connector_unref(exec_ctx, (grpc_connector*)arg);
} else {
GPR_ASSERT(c->endpoint != nullptr);
start_handshake_locked(exec_ctx, c);
gpr_mu_unlock(&c->mu);
}
}
static void chttp2_connector_connect(grpc_exec_ctx* exec_ctx,
grpc_connector* con,
const grpc_connect_in_args* args,
grpc_connect_out_args* result,
grpc_closure* notify) {
chttp2_connector* c = (chttp2_connector*)con;
grpc_resolved_address addr;
grpc_get_subchannel_address_arg(exec_ctx, args->channel_args, &addr);
gpr_mu_lock(&c->mu);
GPR_ASSERT(c->notify == nullptr);
c->notify = notify;
c->args = *args;
c->result = result;
GPR_ASSERT(c->endpoint == nullptr);
chttp2_connector_ref(con); // Ref taken for callback.
GRPC_CLOSURE_INIT(&c->connected, connected, c, grpc_schedule_on_exec_ctx);
GPR_ASSERT(!c->connecting);
c->connecting = true;
grpc_tcp_client_connect(exec_ctx, &c->connected, &c->endpoint,
args->interested_parties, args->channel_args, &addr,
args->deadline);
gpr_mu_unlock(&c->mu);
}
static const grpc_connector_vtable chttp2_connector_vtable = {
chttp2_connector_ref, chttp2_connector_unref, chttp2_connector_shutdown,
chttp2_connector_connect};
grpc_connector* grpc_chttp2_connector_create() {
chttp2_connector* c = (chttp2_connector*)gpr_zalloc(sizeof(*c));
c->base.vtable = &chttp2_connector_vtable;
gpr_mu_init(&c->mu);
gpr_ref_init(&c->refs, 1);
return &c->base;
}
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