src/core/ext/transport/chttp2/server/chttp2_server.cc

   1 /*
   2  *
   3  * Copyright 2015 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/transport/chttp2/server/chttp2_server.h"
  22
  23 #include <inttypes.h>
  24 #include <limits.h>
  25 #include <string.h>
  26
  27 #include <grpc/grpc.h>
  28 #include <grpc/impl/codegen/grpc_types.h>
  29 #include <grpc/support/alloc.h>
  30 #include <grpc/support/log.h>
  31 #include <grpc/support/string_util.h>
  32 #include <grpc/support/sync.h>
  33
  34 #include "absl/strings/str_format.h"
  35
  36 #include "src/core/ext/filters/http/server/http_server_filter.h"
  37 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
  38 #include "src/core/ext/transport/chttp2/transport/internal.h"
  39 #include "src/core/lib/channel/channel_args.h"
  40 #include "src/core/lib/channel/handshaker.h"
  41 #include "src/core/lib/channel/handshaker_registry.h"
  42 #include "src/core/lib/iomgr/endpoint.h"
  43 #include "src/core/lib/iomgr/resolve_address.h"
  44 #include "src/core/lib/iomgr/resource_quota.h"
  45 #include "src/core/lib/iomgr/tcp_server.h"
  46 #include "src/core/lib/slice/slice_internal.h"
  47 #include "src/core/lib/surface/api_trace.h"
  48 #include "src/core/lib/surface/server.h"
  49
  50 struct server_state {
  51   grpc_server* server;
  52   grpc_tcp_server* tcp_server;
  53   grpc_channel_args* args;
  54   gpr_mu mu;
  55   bool shutdown;
  56   grpc_closure tcp_server_shutdown_complete;
  57   grpc_closure* server_destroy_listener_done;
  58   grpc_core::HandshakeManager* pending_handshake_mgrs;
  59   grpc_core::RefCountedPtr<grpc_core::channelz::ListenSocketNode>
  60       channelz_listen_socket;
  61 };
  62
  63 struct server_connection_state {
  64   gpr_refcount refs;
  65   server_state* svr_state;
  66   grpc_pollset* accepting_pollset;
  67   grpc_tcp_server_acceptor* acceptor;
  68   grpc_core::RefCountedPtr<grpc_core::HandshakeManager> handshake_mgr;
  69   // State for enforcing handshake timeout on receiving HTTP/2 settings.
  70   grpc_chttp2_transport* transport;
  71   grpc_millis deadline;
  72   grpc_timer timer;
  73   grpc_closure on_timeout;
  74   grpc_closure on_receive_settings;
  75   grpc_pollset_set* interested_parties;
  76 };
  77
  78 static void server_connection_state_unref(
  79     server_connection_state* connection_state) {
  80   if (gpr_unref(&connection_state->refs)) {
  81     if (connection_state->transport != nullptr) {
  82       GRPC_CHTTP2_UNREF_TRANSPORT(connection_state->transport,
  83                                   "receive settings timeout");
  84     }
  85     grpc_pollset_set_del_pollset(connection_state->interested_parties,
  86                                  connection_state->accepting_pollset);
  87     grpc_pollset_set_destroy(connection_state->interested_parties);
  88     gpr_free(connection_state);
  89   }
  90 }
  91
  92 static void on_timeout(void* arg, grpc_error* error) {
  93   server_connection_state* connection_state =
  94       static_cast<server_connection_state*>(arg);
  95   // Note that we may be called with GRPC_ERROR_NONE when the timer fires
  96   // or with an error indicating that the timer system is being shut down.
  97   if (error != GRPC_ERROR_CANCELLED) {
  98     grpc_transport_op* op = grpc_make_transport_op(nullptr);
  99     op->disconnect_with_error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
 100         "Did not receive HTTP/2 settings before handshake timeout");
 101     grpc_transport_perform_op(&connection_state->transport->base, op);
 102   }
 103   server_connection_state_unref(connection_state);
 104 }
 105
 106 static void on_receive_settings(void* arg, grpc_error* error) {
 107   server_connection_state* connection_state =
 108       static_cast<server_connection_state*>(arg);
 109   if (error == GRPC_ERROR_NONE) {
 110     grpc_timer_cancel(&connection_state->timer);
 111   }
 112   server_connection_state_unref(connection_state);
 113 }
 114
 115 static void on_handshake_done(void* arg, grpc_error* error) {
 116   auto* args = static_cast<grpc_core::HandshakerArgs*>(arg);
 117   server_connection_state* connection_state =
 118       static_cast<server_connection_state*>(args->user_data);
 119   gpr_mu_lock(&connection_state->svr_state->mu);
 120   grpc_resource_user* resource_user = grpc_server_get_default_resource_user(
 121       connection_state->svr_state->server);
 122   if (error != GRPC_ERROR_NONE || connection_state->svr_state->shutdown) {
 123     const char* error_str = grpc_error_string(error);
 124     gpr_log(GPR_DEBUG, "Handshaking failed: %s", error_str);
 125     grpc_resource_user* resource_user = grpc_server_get_default_resource_user(
 126         connection_state->svr_state->server);
 127     if (resource_user != nullptr) {
 128       grpc_resource_user_free(resource_user, GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
 129     }
 130     if (error == GRPC_ERROR_NONE && args->endpoint != nullptr) {
 131       // We were shut down after handshaking completed successfully, so
 132       // destroy the endpoint here.
 133       // TODO(ctiller): It is currently necessary to shutdown endpoints
 134       // before destroying them, even if we know that there are no
 135       // pending read/write callbacks.  This should be fixed, at which
 136       // point this can be removed.
 137       grpc_endpoint_shutdown(args->endpoint, GRPC_ERROR_NONE);
 138       grpc_endpoint_destroy(args->endpoint);
 139       grpc_channel_args_destroy(args->args);
 140       grpc_slice_buffer_destroy_internal(args->read_buffer);
 141       gpr_free(args->read_buffer);
 142     }
 143   } else {
 144     // If the handshaking succeeded but there is no endpoint, then the
 145     // handshaker may have handed off the connection to some external
 146     // code, so we can just clean up here without creating a transport.
 147     if (args->endpoint != nullptr) {
 148       grpc_transport* transport = grpc_create_chttp2_transport(
 149           args->args, args->endpoint, false, resource_user);
 150       grpc_server_setup_transport(
 151           connection_state->svr_state->server, transport,
 152           connection_state->accepting_pollset, args->args,
 153           grpc_chttp2_transport_get_socket_node(transport), resource_user);
 154       // Use notify_on_receive_settings callback to enforce the
 155       // handshake deadline.
 156       connection_state->transport =
 157           reinterpret_cast<grpc_chttp2_transport*>(transport);
 158       gpr_ref(&connection_state->refs);
 159       GRPC_CLOSURE_INIT(&connection_state->on_receive_settings,
 160                         on_receive_settings, connection_state,
 161                         grpc_schedule_on_exec_ctx);
 162       grpc_chttp2_transport_start_reading(
 163           transport, args->read_buffer, &connection_state->on_receive_settings);
 164       grpc_channel_args_destroy(args->args);
 165       gpr_ref(&connection_state->refs);
 166       GRPC_CHTTP2_REF_TRANSPORT((grpc_chttp2_transport*)transport,
 167                                 "receive settings timeout");
 168       GRPC_CLOSURE_INIT(&connection_state->on_timeout, on_timeout,
 169                         connection_state, grpc_schedule_on_exec_ctx);
 170       grpc_timer_init(&connection_state->timer, connection_state->deadline,
 171                       &connection_state->on_timeout);
 172     } else {
 173       if (resource_user != nullptr) {
 174         grpc_resource_user_free(resource_user,
 175                                 GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
 176       }
 177     }
 178   }
 179   connection_state->handshake_mgr->RemoveFromPendingMgrList(
 180       &connection_state->svr_state->pending_handshake_mgrs);
 181   gpr_mu_unlock(&connection_state->svr_state->mu);
 182   connection_state->handshake_mgr.reset();
 183   gpr_free(connection_state->acceptor);
 184   grpc_tcp_server_unref(connection_state->svr_state->tcp_server);
 185   server_connection_state_unref(connection_state);
 186 }
 187
 188 static void on_accept(void* arg, grpc_endpoint* tcp,
 189                       grpc_pollset* accepting_pollset,
 190                       grpc_tcp_server_acceptor* acceptor) {
 191   server_state* state = static_cast<server_state*>(arg);
 192   gpr_mu_lock(&state->mu);
 193   if (state->shutdown) {
 194     gpr_mu_unlock(&state->mu);
 195     grpc_endpoint_shutdown(tcp, GRPC_ERROR_NONE);
 196     grpc_endpoint_destroy(tcp);
 197     gpr_free(acceptor);
 198     return;
 199   }
 200   grpc_resource_user* resource_user =
 201       grpc_server_get_default_resource_user(state->server);
 202   if (resource_user != nullptr &&
 203       !grpc_resource_user_safe_alloc(resource_user,
 204                                      GRPC_RESOURCE_QUOTA_CHANNEL_SIZE)) {
 205     gpr_log(
 206         GPR_ERROR,
 207         "Memory quota exhausted, rejecting the connection, no handshaking.");
 208     gpr_mu_unlock(&state->mu);
 209     grpc_endpoint_shutdown(tcp, GRPC_ERROR_NONE);
 210     grpc_endpoint_destroy(tcp);
 211     gpr_free(acceptor);
 212     return;
 213   }
 214   auto handshake_mgr = grpc_core::MakeRefCounted<grpc_core::HandshakeManager>();
 215   handshake_mgr->AddToPendingMgrList(&state->pending_handshake_mgrs);
 216   grpc_tcp_server_ref(state->tcp_server);
 217   gpr_mu_unlock(&state->mu);
 218   server_connection_state* connection_state =
 219       static_cast<server_connection_state*>(
 220           gpr_zalloc(sizeof(*connection_state)));
 221   gpr_ref_init(&connection_state->refs, 1);
 222   connection_state->svr_state = state;
 223   connection_state->accepting_pollset = accepting_pollset;
 224   connection_state->acceptor = acceptor;
 225   connection_state->handshake_mgr = handshake_mgr;
 226   connection_state->interested_parties = grpc_pollset_set_create();
 227   grpc_pollset_set_add_pollset(connection_state->interested_parties,
 228                                connection_state->accepting_pollset);
 229   grpc_core::HandshakerRegistry::AddHandshakers(
 230       grpc_core::HANDSHAKER_SERVER, state->args,
 231       connection_state->interested_parties,
 232       connection_state->handshake_mgr.get());
 233   const grpc_arg* timeout_arg =
 234       grpc_channel_args_find(state->args, GRPC_ARG_SERVER_HANDSHAKE_TIMEOUT_MS);
 235   connection_state->deadline =
 236       grpc_core::ExecCtx::Get()->Now() +
 237       grpc_channel_arg_get_integer(timeout_arg,
 238                                    {120 * GPR_MS_PER_SEC, 1, INT_MAX});
 239   connection_state->handshake_mgr->DoHandshake(
 240       tcp, state->args, connection_state->deadline, acceptor, on_handshake_done,
 241       connection_state);
 242 }
 243
 244 /* Server callback: start listening on our ports */
 245 static void server_start_listener(grpc_server* /*server*/, void* arg,
 246                                   grpc_pollset** pollsets,
 247                                   size_t pollset_count) {
 248   server_state* state = static_cast<server_state*>(arg);
 249   gpr_mu_lock(&state->mu);
 250   state->shutdown = false;
 251   gpr_mu_unlock(&state->mu);
 252   grpc_tcp_server_start(state->tcp_server, pollsets, pollset_count, on_accept,
 253                         state);
 254 }
 255
 256 static void tcp_server_shutdown_complete(void* arg, grpc_error* error) {
 257   server_state* state = static_cast<server_state*>(arg);
 258   /* ensure all threads have unlocked */
 259   gpr_mu_lock(&state->mu);
 260   grpc_closure* destroy_done = state->server_destroy_listener_done;
 261   GPR_ASSERT(state->shutdown);
 262   if (state->pending_handshake_mgrs != nullptr) {
 263     state->pending_handshake_mgrs->ShutdownAllPending(GRPC_ERROR_REF(error));
 264   }
 265   state->channelz_listen_socket.reset();
 266   gpr_mu_unlock(&state->mu);
 267   // Flush queued work before destroying handshaker factory, since that
 268   // may do a synchronous unref.
 269   grpc_core::ExecCtx::Get()->Flush();
 270   if (destroy_done != nullptr) {
 271     grpc_core::ExecCtx::Run(DEBUG_LOCATION, destroy_done,
 272                             GRPC_ERROR_REF(error));
 273     grpc_core::ExecCtx::Get()->Flush();
 274   }
 275   grpc_channel_args_destroy(state->args);
 276   gpr_mu_destroy(&state->mu);
 277   gpr_free(state);
 278 }
 279
 280 /* Server callback: destroy the tcp listener (so we don't generate further
 281    callbacks) */
 282 static void server_destroy_listener(grpc_server* /*server*/, void* arg,
 283                                     grpc_closure* destroy_done) {
 284   server_state* state = static_cast<server_state*>(arg);
 285   gpr_mu_lock(&state->mu);
 286   state->shutdown = true;
 287   state->server_destroy_listener_done = destroy_done;
 288   grpc_tcp_server* tcp_server = state->tcp_server;
 289   gpr_mu_unlock(&state->mu);
 290   grpc_tcp_server_shutdown_listeners(tcp_server);
 291   grpc_tcp_server_unref(tcp_server);
 292 }
 293
 294 static grpc_error* chttp2_server_add_acceptor(grpc_server* server,
 295                                               const char* name,
 296                                               grpc_channel_args* args) {
 297   grpc_tcp_server* tcp_server = nullptr;
 298   grpc_error* err = GRPC_ERROR_NONE;
 299   server_state* state = nullptr;
 300   const grpc_arg* arg = nullptr;
 301   grpc_core::TcpServerFdHandler** arg_val = nullptr;
 302   state = static_cast<server_state*>(gpr_zalloc(sizeof(*state)));
 303   GRPC_CLOSURE_INIT(&state->tcp_server_shutdown_complete,
 304                     tcp_server_shutdown_complete, state,
 305                     grpc_schedule_on_exec_ctx);
 306   err = grpc_tcp_server_create(&state->tcp_server_shutdown_complete, args,
 307                                &tcp_server);
 308   if (err != GRPC_ERROR_NONE) {
 309     goto error;
 310   }
 311   state->server = server;
 312   state->tcp_server = tcp_server;
 313   state->args = args;
 314   state->shutdown = true;
 315   gpr_mu_init(&state->mu);
 316   // TODO(yangg) channelz
 317   arg = grpc_channel_args_find(args, name);
 318   GPR_ASSERT(arg->type == GRPC_ARG_POINTER);
 319   arg_val = static_cast<grpc_core::TcpServerFdHandler**>(arg->value.pointer.p);
 320   *arg_val = grpc_tcp_server_create_fd_handler(tcp_server);
 321
 322   grpc_server_add_listener(server, state, server_start_listener,
 323                            server_destroy_listener, /* node */ nullptr);
 324   return err;
 325
 326 /* Error path: cleanup and return */
 327 error:
 328   GPR_ASSERT(err != GRPC_ERROR_NONE);
 329   if (tcp_server) {
 330     grpc_tcp_server_unref(tcp_server);
 331   } else {
 332     grpc_channel_args_destroy(args);
 333     gpr_free(state);
 334   }
 335   return err;
 336 }
 337
 338 grpc_error* grpc_chttp2_server_add_port(grpc_server* server, const char* addr,
 339                                         grpc_channel_args* args,
 340                                         int* port_num) {
 341   grpc_resolved_addresses* resolved = nullptr;
 342   grpc_tcp_server* tcp_server = nullptr;
 343   size_t i;
 344   size_t count = 0;
 345   int port_temp;
 346   grpc_error* err = GRPC_ERROR_NONE;
 347   server_state* state = nullptr;
 348   grpc_error** errors = nullptr;
 349   size_t naddrs = 0;
 350   const grpc_arg* arg = nullptr;
 351
 352   *port_num = -1;
 353
 354   if (strncmp(addr, "external:", 9) == 0) {
 355     return chttp2_server_add_acceptor(server, addr, args);
 356   }
 357
 358   /* resolve address */
 359   err = grpc_blocking_resolve_address(addr, "https", &resolved);
 360   if (err != GRPC_ERROR_NONE) {
 361     goto error;
 362   }
 363   state = static_cast<server_state*>(gpr_zalloc(sizeof(*state)));
 364   GRPC_CLOSURE_INIT(&state->tcp_server_shutdown_complete,
 365                     tcp_server_shutdown_complete, state,
 366                     grpc_schedule_on_exec_ctx);
 367   err = grpc_tcp_server_create(&state->tcp_server_shutdown_complete, args,
 368                                &tcp_server);
 369   if (err != GRPC_ERROR_NONE) {
 370     goto error;
 371   }
 372
 373   state->server = server;
 374   state->tcp_server = tcp_server;
 375   state->args = args;
 376   state->shutdown = true;
 377   gpr_mu_init(&state->mu);
 378
 379   naddrs = resolved->naddrs;
 380   errors = static_cast<grpc_error**>(gpr_malloc(sizeof(*errors) * naddrs));
 381   for (i = 0; i < naddrs; i++) {
 382     errors[i] =
 383         grpc_tcp_server_add_port(tcp_server, &resolved->addrs[i], &port_temp);
 384     if (errors[i] == GRPC_ERROR_NONE) {
 385       if (*port_num == -1) {
 386         *port_num = port_temp;
 387       } else {
 388         GPR_ASSERT(*port_num == port_temp);
 389       }
 390       count++;
 391     }
 392   }
 393   if (count == 0) {
 394     char* msg;
 395     gpr_asprintf(&msg, "No address added out of total %" PRIuPTR " resolved",
 396                  naddrs);
 397     err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
 398     gpr_free(msg);
 399     goto error;
 400   } else if (count != naddrs) {
 401     char* msg;
 402     gpr_asprintf(&msg,
 403                  "Only %" PRIuPTR " addresses added out of total %" PRIuPTR
 404                  " resolved",
 405                  count, naddrs);
 406     err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
 407     gpr_free(msg);
 408
 409     const char* warning_message = grpc_error_string(err);
 410     gpr_log(GPR_INFO, "WARNING: %s", warning_message);
 411
 412     /* we managed to bind some addresses: continue */
 413   }
 414   grpc_resolved_addresses_destroy(resolved);
 415
 416   arg = grpc_channel_args_find(args, GRPC_ARG_ENABLE_CHANNELZ);
 417   if (grpc_channel_arg_get_bool(arg, GRPC_ENABLE_CHANNELZ_DEFAULT)) {
 418     state->channelz_listen_socket =
 419         grpc_core::MakeRefCounted<grpc_core::channelz::ListenSocketNode>(
 420             addr, absl::StrFormat("chttp2 listener %s", addr));
 421   }
 422
 423   /* Register with the server only upon success */
 424   grpc_server_add_listener(server, state, server_start_listener,
 425                            server_destroy_listener,
 426                            state->channelz_listen_socket);
 427   goto done;
 428
 429 /* Error path: cleanup and return */
 430 error:
 431   GPR_ASSERT(err != GRPC_ERROR_NONE);
 432   if (resolved) {
 433     grpc_resolved_addresses_destroy(resolved);
 434   }
 435   if (tcp_server) {
 436     grpc_tcp_server_unref(tcp_server);
 437   } else {
 438     grpc_channel_args_destroy(args);
 439     gpr_free(state);
 440   }
 441   *port_num = 0;
 442
 443 done:
 444   if (errors != nullptr) {
 445     for (i = 0; i < naddrs; i++) {
 446       GRPC_ERROR_UNREF(errors[i]);
 447     }
 448     gpr_free(errors);
 449   }
 450   return err;
 451 }