src/core/ext/filters/client_channel/http_connect_handshaker.cc

   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/lib/channel/channel_args.h"
  33 #include "src/core/lib/channel/handshaker_registry.h"
  34 #include "src/core/lib/gpr/string.h"
  35 #include "src/core/lib/gprpp/sync.h"
  36 #include "src/core/lib/http/format_request.h"
  37 #include "src/core/lib/http/parser.h"
  38 #include "src/core/lib/slice/slice_internal.h"
  39 #include "src/core/lib/uri/uri_parser.h"
  40
  41 namespace grpc_core {
  42
  43 namespace {
  44
  45 class HttpConnectHandshaker : public Handshaker {
  46  public:
  47   HttpConnectHandshaker();
  48   void Shutdown(grpc_error* why) override;
  49   void DoHandshake(grpc_tcp_server_acceptor* acceptor,
  50                    grpc_closure* on_handshake_done,
  51                    HandshakerArgs* args) override;
  52   const char* name() const override { return "http_connect"; }
  53
  54  private:
  55   virtual ~HttpConnectHandshaker();
  56   void CleanupArgsForFailureLocked();
  57   void HandshakeFailedLocked(grpc_error* error);
  58   static void OnWriteDone(void* arg, grpc_error* error);
  59   static void OnReadDone(void* arg, grpc_error* error);
  60
  61   gpr_mu mu_;
  62
  63   bool is_shutdown_ = false;
  64   // Endpoint and read buffer to destroy after a shutdown.
  65   grpc_endpoint* endpoint_to_destroy_ = nullptr;
  66   grpc_slice_buffer* read_buffer_to_destroy_ = nullptr;
  67
  68   // State saved while performing the handshake.
  69   HandshakerArgs* args_ = nullptr;
  70   grpc_closure* on_handshake_done_ = nullptr;
  71
  72   // Objects for processing the HTTP CONNECT request and response.
  73   grpc_slice_buffer write_buffer_;
  74   grpc_closure request_done_closure_;
  75   grpc_closure response_read_closure_;
  76   grpc_http_parser http_parser_;
  77   grpc_http_response http_response_;
  78 };
  79
  80 HttpConnectHandshaker::~HttpConnectHandshaker() {
  81   gpr_mu_destroy(&mu_);
  82   if (endpoint_to_destroy_ != nullptr) {
  83     grpc_endpoint_destroy(endpoint_to_destroy_);
  84   }
  85   if (read_buffer_to_destroy_ != nullptr) {
  86     grpc_slice_buffer_destroy_internal(read_buffer_to_destroy_);
  87     gpr_free(read_buffer_to_destroy_);
  88   }
  89   grpc_slice_buffer_destroy_internal(&write_buffer_);
  90   grpc_http_parser_destroy(&http_parser_);
  91   grpc_http_response_destroy(&http_response_);
  92 }
  93
  94 // Set args fields to nullptr, saving the endpoint and read buffer for
  95 // later destruction.
  96 void HttpConnectHandshaker::CleanupArgsForFailureLocked() {
  97   endpoint_to_destroy_ = args_->endpoint;
  98   args_->endpoint = nullptr;
  99   read_buffer_to_destroy_ = args_->read_buffer;
 100   args_->read_buffer = nullptr;
 101   grpc_channel_args_destroy(args_->args);
 102   args_->args = nullptr;
 103 }
 104
 105 // If the handshake failed or we're shutting down, clean up and invoke the
 106 // callback with the error.
 107 void HttpConnectHandshaker::HandshakeFailedLocked(grpc_error* error) {
 108   if (error == GRPC_ERROR_NONE) {
 109     // If we were shut down after an endpoint operation succeeded but
 110     // before the endpoint callback was invoked, we need to generate our
 111     // own error.
 112     error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Handshaker shutdown");
 113   }
 114   if (!is_shutdown_) {
 115     // TODO(ctiller): It is currently necessary to shutdown endpoints
 116     // before destroying them, even if we know that there are no
 117     // pending read/write callbacks.  This should be fixed, at which
 118     // point this can be removed.
 119     grpc_endpoint_shutdown(args_->endpoint, GRPC_ERROR_REF(error));
 120     // Not shutting down, so the handshake failed.  Clean up before
 121     // invoking the callback.
 122     CleanupArgsForFailureLocked();
 123     // Set shutdown to true so that subsequent calls to
 124     // http_connect_handshaker_shutdown() do nothing.
 125     is_shutdown_ = true;
 126   }
 127   // Invoke callback.
 128   GRPC_CLOSURE_SCHED(on_handshake_done_, error);
 129 }
 130
 131 // Callback invoked when finished writing HTTP CONNECT request.
 132 void HttpConnectHandshaker::OnWriteDone(void* arg, grpc_error* error) {
 133   auto* handshaker = static_cast<HttpConnectHandshaker*>(arg);
 134   gpr_mu_lock(&handshaker->mu_);
 135   if (error != GRPC_ERROR_NONE || handshaker->is_shutdown_) {
 136     // If the write failed or we're shutting down, clean up and invoke the
 137     // callback with the error.
 138     handshaker->HandshakeFailedLocked(GRPC_ERROR_REF(error));
 139     gpr_mu_unlock(&handshaker->mu_);
 140     handshaker->Unref();
 141   } else {
 142     // Otherwise, read the response.
 143     // The read callback inherits our ref to the handshaker.
 144     grpc_endpoint_read(handshaker->args_->endpoint,
 145                        handshaker->args_->read_buffer,
 146                        &handshaker->response_read_closure_, /*urgent=*/true);
 147     gpr_mu_unlock(&handshaker->mu_);
 148   }
 149 }
 150
 151 // Callback invoked for reading HTTP CONNECT response.
 152 void HttpConnectHandshaker::OnReadDone(void* arg, grpc_error* error) {
 153   auto* handshaker = static_cast<HttpConnectHandshaker*>(arg);
 154
 155   gpr_mu_lock(&handshaker->mu_);
 156   if (error != GRPC_ERROR_NONE || handshaker->is_shutdown_) {
 157     // If the read failed or we're shutting down, clean up and invoke the
 158     // callback with the error.
 159     handshaker->HandshakeFailedLocked(GRPC_ERROR_REF(error));
 160     goto done;
 161   }
 162   // Add buffer to parser.
 163   for (size_t i = 0; i < handshaker->args_->read_buffer->count; ++i) {
 164     if (GRPC_SLICE_LENGTH(handshaker->args_->read_buffer->slices[i]) > 0) {
 165       size_t body_start_offset = 0;
 166       error = grpc_http_parser_parse(&handshaker->http_parser_,
 167                                      handshaker->args_->read_buffer->slices[i],
 168                                      &body_start_offset);
 169       if (error != GRPC_ERROR_NONE) {
 170         handshaker->HandshakeFailedLocked(error);
 171         goto done;
 172       }
 173       if (handshaker->http_parser_.state == GRPC_HTTP_BODY) {
 174         // Remove the data we've already read from the read buffer,
 175         // leaving only the leftover bytes (if any).
 176         grpc_slice_buffer tmp_buffer;
 177         grpc_slice_buffer_init(&tmp_buffer);
 178         if (body_start_offset <
 179             GRPC_SLICE_LENGTH(handshaker->args_->read_buffer->slices[i])) {
 180           grpc_slice_buffer_add(
 181               &tmp_buffer,
 182               grpc_slice_split_tail(&handshaker->args_->read_buffer->slices[i],
 183                                     body_start_offset));
 184         }
 185         grpc_slice_buffer_addn(&tmp_buffer,
 186                                &handshaker->args_->read_buffer->slices[i + 1],
 187                                handshaker->args_->read_buffer->count - i - 1);
 188         grpc_slice_buffer_swap(handshaker->args_->read_buffer, &tmp_buffer);
 189         grpc_slice_buffer_destroy_internal(&tmp_buffer);
 190         break;
 191       }
 192     }
 193   }
 194   // If we're not done reading the response, read more data.
 195   // TODO(roth): In practice, I suspect that the response to a CONNECT
 196   // request will never include a body, in which case this check is
 197   // sufficient.  However, the language of RFC-2817 doesn't explicitly
 198   // forbid the response from including a body.  If there is a body,
 199   // it's possible that we might have parsed part but not all of the
 200   // body, in which case this check will cause us to fail to parse the
 201   // remainder of the body.  If that ever becomes an issue, we may
 202   // need to fix the HTTP parser to understand when the body is
 203   // complete (e.g., handling chunked transfer encoding or looking
 204   // at the Content-Length: header).
 205   if (handshaker->http_parser_.state != GRPC_HTTP_BODY) {
 206     grpc_slice_buffer_reset_and_unref_internal(handshaker->args_->read_buffer);
 207     grpc_endpoint_read(handshaker->args_->endpoint,
 208                        handshaker->args_->read_buffer,
 209                        &handshaker->response_read_closure_, /*urgent=*/true);
 210     gpr_mu_unlock(&handshaker->mu_);
 211     return;
 212   }
 213   // Make sure we got a 2xx response.
 214   if (handshaker->http_response_.status < 200 ||
 215       handshaker->http_response_.status >= 300) {
 216     char* msg;
 217     gpr_asprintf(&msg, "HTTP proxy returned response code %d",
 218                  handshaker->http_response_.status);
 219     error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
 220     gpr_free(msg);
 221     handshaker->HandshakeFailedLocked(error);
 222     goto done;
 223   }
 224   // Success.  Invoke handshake-done callback.
 225   GRPC_CLOSURE_SCHED(handshaker->on_handshake_done_, error);
 226 done:
 227   // Set shutdown to true so that subsequent calls to
 228   // http_connect_handshaker_shutdown() do nothing.
 229   handshaker->is_shutdown_ = true;
 230   gpr_mu_unlock(&handshaker->mu_);
 231   handshaker->Unref();
 232 }
 233
 234 //
 235 // Public handshaker methods
 236 //
 237
 238 void HttpConnectHandshaker::Shutdown(grpc_error* why) {
 239   gpr_mu_lock(&mu_);
 240   if (!is_shutdown_) {
 241     is_shutdown_ = true;
 242     grpc_endpoint_shutdown(args_->endpoint, GRPC_ERROR_REF(why));
 243     CleanupArgsForFailureLocked();
 244   }
 245   gpr_mu_unlock(&mu_);
 246   GRPC_ERROR_UNREF(why);
 247 }
 248
 249 void HttpConnectHandshaker::DoHandshake(grpc_tcp_server_acceptor* acceptor,
 250                                         grpc_closure* on_handshake_done,
 251                                         HandshakerArgs* args) {
 252   // Check for HTTP CONNECT channel arg.
 253   // If not found, invoke on_handshake_done without doing anything.
 254   const grpc_arg* arg =
 255       grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_SERVER);
 256   char* server_name = grpc_channel_arg_get_string(arg);
 257   if (server_name == nullptr) {
 258     // Set shutdown to true so that subsequent calls to
 259     // http_connect_handshaker_shutdown() do nothing.
 260     gpr_mu_lock(&mu_);
 261     is_shutdown_ = true;
 262     gpr_mu_unlock(&mu_);
 263     GRPC_CLOSURE_SCHED(on_handshake_done, GRPC_ERROR_NONE);
 264     return;
 265   }
 266   // Get headers from channel args.
 267   arg = grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_HEADERS);
 268   char* arg_header_string = grpc_channel_arg_get_string(arg);
 269   grpc_http_header* headers = nullptr;
 270   size_t num_headers = 0;
 271   char** header_strings = nullptr;
 272   size_t num_header_strings = 0;
 273   if (arg_header_string != nullptr) {
 274     gpr_string_split(arg_header_string, "\n", &header_strings,
 275                      &num_header_strings);
 276     headers = static_cast<grpc_http_header*>(
 277         gpr_malloc(sizeof(grpc_http_header) * num_header_strings));
 278     for (size_t i = 0; i < num_header_strings; ++i) {
 279       char* sep = strchr(header_strings[i], ':');
 280
 281       if (sep == nullptr) {
 282         gpr_log(GPR_ERROR, "skipping unparseable HTTP CONNECT header: %s",
 283                 header_strings[i]);
 284         continue;
 285       }
 286       *sep = '\0';
 287       headers[num_headers].key = header_strings[i];
 288       headers[num_headers].value = sep + 1;
 289       ++num_headers;
 290     }
 291   }
 292   // Save state in the handshaker object.
 293   MutexLock lock(&mu_);
 294   args_ = args;
 295   on_handshake_done_ = on_handshake_done;
 296   // Log connection via proxy.
 297   char* proxy_name = grpc_endpoint_get_peer(args->endpoint);
 298   gpr_log(GPR_INFO, "Connecting to server %s via HTTP proxy %s", server_name,
 299           proxy_name);
 300   gpr_free(proxy_name);
 301   // Construct HTTP CONNECT request.
 302   grpc_httpcli_request request;
 303   request.host = server_name;
 304   request.ssl_host_override = nullptr;
 305   request.http.method = (char*)"CONNECT";
 306   request.http.path = server_name;
 307   request.http.version = GRPC_HTTP_HTTP10;  // Set by OnReadDone
 308   request.http.hdrs = headers;
 309   request.http.hdr_count = num_headers;
 310   request.http.body_length = 0;
 311   request.http.body = nullptr;
 312   request.handshaker = &grpc_httpcli_plaintext;
 313   grpc_slice request_slice = grpc_httpcli_format_connect_request(&request);
 314   grpc_slice_buffer_add(&write_buffer_, request_slice);
 315   // Clean up.
 316   gpr_free(headers);
 317   for (size_t i = 0; i < num_header_strings; ++i) {
 318     gpr_free(header_strings[i]);
 319   }
 320   gpr_free(header_strings);
 321   // Take a new ref to be held by the write callback.
 322   Ref().release();
 323   grpc_endpoint_write(args->endpoint, &write_buffer_, &request_done_closure_,
 324                       nullptr);
 325 }
 326
 327 HttpConnectHandshaker::HttpConnectHandshaker() {
 328   gpr_mu_init(&mu_);
 329   grpc_slice_buffer_init(&write_buffer_);
 330   GRPC_CLOSURE_INIT(&request_done_closure_, &HttpConnectHandshaker::OnWriteDone,
 331                     this, grpc_schedule_on_exec_ctx);
 332   GRPC_CLOSURE_INIT(&response_read_closure_, &HttpConnectHandshaker::OnReadDone,
 333                     this, grpc_schedule_on_exec_ctx);
 334   grpc_http_parser_init(&http_parser_, GRPC_HTTP_RESPONSE, &http_response_);
 335 }
 336
 337 //
 338 // handshaker factory
 339 //
 340
 341 class HttpConnectHandshakerFactory : public HandshakerFactory {
 342  public:
 343   void AddHandshakers(const grpc_channel_args* args,
 344                       grpc_pollset_set* interested_parties,
 345                       HandshakeManager* handshake_mgr) override {
 346     handshake_mgr->Add(MakeRefCounted<HttpConnectHandshaker>());
 347   }
 348   ~HttpConnectHandshakerFactory() override = default;
 349 };
 350
 351 }  // namespace
 352
 353 }  // namespace grpc_core
 354
 355 void grpc_http_connect_register_handshaker_factory() {
 356   using namespace grpc_core;
 357   HandshakerRegistry::RegisterHandshakerFactory(
 358       true /* at_start */, HANDSHAKER_CLIENT,
 359       UniquePtr<HandshakerFactory>(New<HttpConnectHandshakerFactory>()));
 360 }