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/*
*
* Copyright 2016 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 <grpc/support/port_platform.h>
#include "src/core/lib/transport/http_connect_handshaker.h"
#include <limits.h>
#include <string.h>
#include <memory>
#include <string>
#include "absl/base/thread_annotations.h"
#include "absl/memory/memory.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include <grpc/impl/codegen/grpc_types.h>
#include <grpc/slice.h>
#include <grpc/slice_buffer.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/config/core_configuration.h"
#include "src/core/lib/gpr/string.h"
#include "src/core/lib/gprpp/debug_location.h"
#include "src/core/lib/gprpp/ref_counted_ptr.h"
#include "src/core/lib/gprpp/sync.h"
#include "src/core/lib/http/format_request.h"
#include "src/core/lib/http/parser.h"
#include "src/core/lib/iomgr/closure.h"
#include "src/core/lib/iomgr/endpoint.h"
#include "src/core/lib/iomgr/error.h"
#include "src/core/lib/iomgr/exec_ctx.h"
#include "src/core/lib/iomgr/iomgr_fwd.h"
#include "src/core/lib/iomgr/tcp_server.h"
#include "src/core/lib/slice/slice_internal.h"
#include "src/core/lib/transport/handshaker.h"
#include "src/core/lib/transport/handshaker_factory.h"
#include "src/core/lib/transport/handshaker_registry.h"
namespace grpc_core {
namespace {
class HttpConnectHandshaker : public Handshaker {
public:
HttpConnectHandshaker();
void Shutdown(grpc_error_handle why) override;
void DoHandshake(grpc_tcp_server_acceptor* acceptor,
grpc_closure* on_handshake_done,
HandshakerArgs* args) override;
const char* name() const override { return "http_connect"; }
private:
~HttpConnectHandshaker() override;
void CleanupArgsForFailureLocked() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
void HandshakeFailedLocked(grpc_error_handle error)
ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
static void OnWriteDone(void* arg, grpc_error_handle error);
static void OnReadDone(void* arg, grpc_error_handle error);
static void OnWriteDoneScheduler(void* arg, grpc_error_handle error);
static void OnReadDoneScheduler(void* arg, grpc_error_handle error);
Mutex mu_;
bool is_shutdown_ ABSL_GUARDED_BY(mu_) = false;
// Endpoint and read buffer to destroy after a shutdown.
grpc_endpoint* endpoint_to_destroy_ ABSL_GUARDED_BY(mu_) = nullptr;
grpc_slice_buffer* read_buffer_to_destroy_ ABSL_GUARDED_BY(mu_) = nullptr;
// State saved while performing the handshake.
HandshakerArgs* args_ = nullptr;
grpc_closure* on_handshake_done_ = nullptr;
// Objects for processing the HTTP CONNECT request and response.
grpc_slice_buffer write_buffer_ ABSL_GUARDED_BY(mu_);
grpc_closure request_done_closure_ ABSL_GUARDED_BY(mu_);
grpc_closure response_read_closure_ ABSL_GUARDED_BY(mu_);
grpc_http_parser http_parser_ ABSL_GUARDED_BY(mu_);
grpc_http_response http_response_ ABSL_GUARDED_BY(mu_);
};
HttpConnectHandshaker::~HttpConnectHandshaker() {
if (endpoint_to_destroy_ != nullptr) {
grpc_endpoint_destroy(endpoint_to_destroy_);
}
if (read_buffer_to_destroy_ != nullptr) {
grpc_slice_buffer_destroy_internal(read_buffer_to_destroy_);
gpr_free(read_buffer_to_destroy_);
}
grpc_slice_buffer_destroy_internal(&write_buffer_);
grpc_http_parser_destroy(&http_parser_);
grpc_http_response_destroy(&http_response_);
}
// Set args fields to nullptr, saving the endpoint and read buffer for
// later destruction.
void HttpConnectHandshaker::CleanupArgsForFailureLocked() {
endpoint_to_destroy_ = args_->endpoint;
args_->endpoint = nullptr;
read_buffer_to_destroy_ = args_->read_buffer;
args_->read_buffer = nullptr;
grpc_channel_args_destroy(args_->args);
args_->args = nullptr;
}
// If the handshake failed or we're shutting down, clean up and invoke the
// callback with the error.
void HttpConnectHandshaker::HandshakeFailedLocked(grpc_error_handle error) {
if (error == GRPC_ERROR_NONE) {
// If we were shut down after an endpoint operation succeeded but
// before the endpoint callback was invoked, we need to generate our
// own error.
error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Handshaker shutdown");
}
if (!is_shutdown_) {
// 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(args_->endpoint, GRPC_ERROR_REF(error));
// Not shutting down, so the handshake failed. Clean up before
// invoking the callback.
CleanupArgsForFailureLocked();
// Set shutdown to true so that subsequent calls to
// http_connect_handshaker_shutdown() do nothing.
is_shutdown_ = true;
}
// Invoke callback.
ExecCtx::Run(DEBUG_LOCATION, on_handshake_done_, error);
}
// This callback can be invoked inline while already holding onto the mutex. To
// avoid deadlocks, schedule OnWriteDone on ExecCtx.
void HttpConnectHandshaker::OnWriteDoneScheduler(void* arg,
grpc_error_handle error) {
auto* handshaker = static_cast<HttpConnectHandshaker*>(arg);
ExecCtx::Run(DEBUG_LOCATION,
GRPC_CLOSURE_INIT(&handshaker->request_done_closure_,
&HttpConnectHandshaker::OnWriteDone,
handshaker, grpc_schedule_on_exec_ctx),
GRPC_ERROR_REF(error));
}
// Callback invoked when finished writing HTTP CONNECT request.
void HttpConnectHandshaker::OnWriteDone(void* arg, grpc_error_handle error) {
auto* handshaker = static_cast<HttpConnectHandshaker*>(arg);
ReleasableMutexLock lock(&handshaker->mu_);
if (error != GRPC_ERROR_NONE || handshaker->is_shutdown_) {
// If the write failed or we're shutting down, clean up and invoke the
// callback with the error.
handshaker->HandshakeFailedLocked(GRPC_ERROR_REF(error));
lock.Release();
handshaker->Unref();
} else {
// Otherwise, read the response.
// The read callback inherits our ref to the handshaker.
grpc_endpoint_read(
handshaker->args_->endpoint, handshaker->args_->read_buffer,
GRPC_CLOSURE_INIT(&handshaker->response_read_closure_,
&HttpConnectHandshaker::OnReadDoneScheduler,
handshaker, grpc_schedule_on_exec_ctx),
/*urgent=*/true, /*min_progress_size=*/1);
}
}
// This callback can be invoked inline while already holding onto the mutex. To
// avoid deadlocks, schedule OnReadDone on ExecCtx.
void HttpConnectHandshaker::OnReadDoneScheduler(void* arg,
grpc_error_handle error) {
auto* handshaker = static_cast<HttpConnectHandshaker*>(arg);
ExecCtx::Run(DEBUG_LOCATION,
GRPC_CLOSURE_INIT(&handshaker->response_read_closure_,
&HttpConnectHandshaker::OnReadDone, handshaker,
grpc_schedule_on_exec_ctx),
GRPC_ERROR_REF(error));
}
// Callback invoked for reading HTTP CONNECT response.
void HttpConnectHandshaker::OnReadDone(void* arg, grpc_error_handle error) {
auto* handshaker = static_cast<HttpConnectHandshaker*>(arg);
ReleasableMutexLock lock(&handshaker->mu_);
if (error != GRPC_ERROR_NONE || handshaker->is_shutdown_) {
// If the read failed or we're shutting down, clean up and invoke the
// callback with the error.
handshaker->HandshakeFailedLocked(GRPC_ERROR_REF(error));
goto done;
}
// Add buffer to parser.
for (size_t i = 0; i < handshaker->args_->read_buffer->count; ++i) {
if (GRPC_SLICE_LENGTH(handshaker->args_->read_buffer->slices[i]) > 0) {
size_t body_start_offset = 0;
error = grpc_http_parser_parse(&handshaker->http_parser_,
handshaker->args_->read_buffer->slices[i],
&body_start_offset);
if (error != GRPC_ERROR_NONE) {
handshaker->HandshakeFailedLocked(error);
goto done;
}
if (handshaker->http_parser_.state == GRPC_HTTP_BODY) {
// Remove the data we've already read from the read buffer,
// leaving only the leftover bytes (if any).
grpc_slice_buffer tmp_buffer;
grpc_slice_buffer_init(&tmp_buffer);
if (body_start_offset <
GRPC_SLICE_LENGTH(handshaker->args_->read_buffer->slices[i])) {
grpc_slice_buffer_add(
&tmp_buffer,
grpc_slice_split_tail(&handshaker->args_->read_buffer->slices[i],
body_start_offset));
}
grpc_slice_buffer_addn(&tmp_buffer,
&handshaker->args_->read_buffer->slices[i + 1],
handshaker->args_->read_buffer->count - i - 1);
grpc_slice_buffer_swap(handshaker->args_->read_buffer, &tmp_buffer);
grpc_slice_buffer_destroy_internal(&tmp_buffer);
break;
}
}
}
// If we're not done reading the response, read more data.
// TODO(roth): In practice, I suspect that the response to a CONNECT
// request will never include a body, in which case this check is
// sufficient. However, the language of RFC-2817 doesn't explicitly
// forbid the response from including a body. If there is a body,
// it's possible that we might have parsed part but not all of the
// body, in which case this check will cause us to fail to parse the
// remainder of the body. If that ever becomes an issue, we may
// need to fix the HTTP parser to understand when the body is
// complete (e.g., handling chunked transfer encoding or looking
// at the Content-Length: header).
if (handshaker->http_parser_.state != GRPC_HTTP_BODY) {
grpc_slice_buffer_reset_and_unref_internal(handshaker->args_->read_buffer);
grpc_endpoint_read(
handshaker->args_->endpoint, handshaker->args_->read_buffer,
GRPC_CLOSURE_INIT(&handshaker->response_read_closure_,
&HttpConnectHandshaker::OnReadDoneScheduler,
handshaker, grpc_schedule_on_exec_ctx),
/*urgent=*/true, /*min_progress_size=*/1);
return;
}
// Make sure we got a 2xx response.
if (handshaker->http_response_.status < 200 ||
handshaker->http_response_.status >= 300) {
error = GRPC_ERROR_CREATE_FROM_CPP_STRING(
absl::StrCat("HTTP proxy returned response code ",
handshaker->http_response_.status));
handshaker->HandshakeFailedLocked(error);
goto done;
}
// Success. Invoke handshake-done callback.
ExecCtx::Run(DEBUG_LOCATION, handshaker->on_handshake_done_, error);
done:
// Set shutdown to true so that subsequent calls to
// http_connect_handshaker_shutdown() do nothing.
handshaker->is_shutdown_ = true;
lock.Release();
handshaker->Unref();
}
//
// Public handshaker methods
//
void HttpConnectHandshaker::Shutdown(grpc_error_handle why) {
{
MutexLock lock(&mu_);
if (!is_shutdown_) {
is_shutdown_ = true;
grpc_endpoint_shutdown(args_->endpoint, GRPC_ERROR_REF(why));
CleanupArgsForFailureLocked();
}
}
GRPC_ERROR_UNREF(why);
}
void HttpConnectHandshaker::DoHandshake(grpc_tcp_server_acceptor* /*acceptor*/,
grpc_closure* on_handshake_done,
HandshakerArgs* args) {
// Check for HTTP CONNECT channel arg.
// If not found, invoke on_handshake_done without doing anything.
const grpc_arg* arg =
grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_SERVER);
char* server_name = grpc_channel_arg_get_string(arg);
if (server_name == nullptr) {
// Set shutdown to true so that subsequent calls to
// http_connect_handshaker_shutdown() do nothing.
{
MutexLock lock(&mu_);
is_shutdown_ = true;
}
ExecCtx::Run(DEBUG_LOCATION, on_handshake_done, GRPC_ERROR_NONE);
return;
}
// Get headers from channel args.
arg = grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_HEADERS);
char* arg_header_string = grpc_channel_arg_get_string(arg);
grpc_http_header* headers = nullptr;
size_t num_headers = 0;
char** header_strings = nullptr;
size_t num_header_strings = 0;
if (arg_header_string != nullptr) {
gpr_string_split(arg_header_string, "\n", &header_strings,
&num_header_strings);
headers = static_cast<grpc_http_header*>(
gpr_malloc(sizeof(grpc_http_header) * num_header_strings));
for (size_t i = 0; i < num_header_strings; ++i) {
char* sep = strchr(header_strings[i], ':');
if (sep == nullptr) {
gpr_log(GPR_ERROR, "skipping unparseable HTTP CONNECT header: %s",
header_strings[i]);
continue;
}
*sep = '\0';
headers[num_headers].key = header_strings[i];
headers[num_headers].value = sep + 1;
++num_headers;
}
}
// Save state in the handshaker object.
MutexLock lock(&mu_);
args_ = args;
on_handshake_done_ = on_handshake_done;
// Log connection via proxy.
std::string proxy_name(grpc_endpoint_get_peer(args->endpoint));
gpr_log(GPR_INFO, "Connecting to server %s via HTTP proxy %s", server_name,
proxy_name.c_str());
// Construct HTTP CONNECT request.
grpc_http_request request;
request.method = const_cast<char*>("CONNECT");
request.version = GRPC_HTTP_HTTP10; // Set by OnReadDone
request.hdrs = headers;
request.hdr_count = num_headers;
request.body_length = 0;
request.body = nullptr;
grpc_slice request_slice =
grpc_httpcli_format_connect_request(&request, server_name, server_name);
grpc_slice_buffer_add(&write_buffer_, request_slice);
// Clean up.
gpr_free(headers);
for (size_t i = 0; i < num_header_strings; ++i) {
gpr_free(header_strings[i]);
}
gpr_free(header_strings);
// Take a new ref to be held by the write callback.
Ref().release();
grpc_endpoint_write(
args->endpoint, &write_buffer_,
GRPC_CLOSURE_INIT(&request_done_closure_,
&HttpConnectHandshaker::OnWriteDoneScheduler, this,
grpc_schedule_on_exec_ctx),
nullptr, /*max_frame_size=*/INT_MAX);
}
HttpConnectHandshaker::HttpConnectHandshaker() {
grpc_slice_buffer_init(&write_buffer_);
grpc_http_parser_init(&http_parser_, GRPC_HTTP_RESPONSE, &http_response_);
}
//
// handshaker factory
//
class HttpConnectHandshakerFactory : public HandshakerFactory {
public:
void AddHandshakers(const grpc_channel_args* /*args*/,
grpc_pollset_set* /*interested_parties*/,
HandshakeManager* handshake_mgr) override {
handshake_mgr->Add(MakeRefCounted<HttpConnectHandshaker>());
}
~HttpConnectHandshakerFactory() override = default;
};
} // namespace
void RegisterHttpConnectHandshaker(CoreConfiguration::Builder* builder) {
builder->handshaker_registry()->RegisterHandshakerFactory(
true /* at_start */, HANDSHAKER_CLIENT,
absl::make_unique<HttpConnectHandshakerFactory>());
}
} // namespace grpc_core