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 "src/core/ext/filters/http/server/http_server_filter.h"
  35 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
  36 #include "src/core/ext/transport/chttp2/transport/internal.h"
  37 #include "src/core/lib/channel/channel_args.h"
  38 #include "src/core/lib/channel/handshaker.h"
  39 #include "src/core/lib/channel/handshaker_registry.h"
  40 #include "src/core/lib/iomgr/endpoint.h"
  41 #include "src/core/lib/iomgr/resolve_address.h"
  42 #include "src/core/lib/iomgr/resource_quota.h"
  43 #include "src/core/lib/iomgr/tcp_server.h"
  44 #include "src/core/lib/slice/slice_internal.h"
  45 #include "src/core/lib/surface/api_trace.h"
  46 #include "src/core/lib/surface/server.h"
  47
  48 typedef struct {
  49   grpc_server* server;
  50   grpc_tcp_server* tcp_server;
  51   grpc_channel_args* args;
  52   gpr_mu mu;
  53   bool shutdown;
  54   grpc_closure tcp_server_shutdown_complete;
  55   grpc_closure* server_destroy_listener_done;
  56   grpc_core::HandshakeManager* pending_handshake_mgrs;
  57   grpc_core::RefCountedPtr<grpc_core::channelz::ListenSocketNode>
  58       channelz_listen_socket;
  59 } server_state;
  60
  61 typedef struct {
  62   gpr_refcount refs;
  63   server_state* svr_state;
  64   grpc_pollset* accepting_pollset;
  65   grpc_tcp_server_acceptor* acceptor;
  66   grpc_core::RefCountedPtr<grpc_core::HandshakeManager> handshake_mgr;
  67   // State for enforcing handshake timeout on receiving HTTP/2 settings.
  68   grpc_chttp2_transport* transport;
  69   grpc_millis deadline;
  70   grpc_timer timer;
  71   grpc_closure on_timeout;
  72   grpc_closure on_receive_settings;
  73   grpc_pollset_set* interested_parties;
  74 } server_connection_state;
  75
  76 static void server_connection_state_unref(
  77     server_connection_state* connection_state) {
  78   if (gpr_unref(&connection_state->refs)) {
  79     if (connection_state->transport != nullptr) {
  80       GRPC_CHTTP2_UNREF_TRANSPORT(connection_state->transport,
  81                                   "receive settings timeout");
  82     }
  83     grpc_pollset_set_del_pollset(connection_state->interested_parties,
  84                                  connection_state->accepting_pollset);
  85     grpc_pollset_set_destroy(connection_state->interested_parties);
  86     gpr_free(connection_state);
  87   }
  88 }
  89
  90 static void on_timeout(void* arg, grpc_error* error) {
  91   server_connection_state* connection_state =
  92       static_cast<server_connection_state*>(arg);
  93   // Note that we may be called with GRPC_ERROR_NONE when the timer fires
  94   // or with an error indicating that the timer system is being shut down.
  95   if (error != GRPC_ERROR_CANCELLED) {
  96     grpc_transport_op* op = grpc_make_transport_op(nullptr);
  97     op->disconnect_with_error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
  98         "Did not receive HTTP/2 settings before handshake timeout");
  99     grpc_transport_perform_op(&connection_state->transport->base, op);
 100   }
 101   server_connection_state_unref(connection_state);
 102 }
 103
 104 static void on_receive_settings(void* arg, grpc_error* error) {
 105   server_connection_state* connection_state =
 106       static_cast<server_connection_state*>(arg);
 107   if (error == GRPC_ERROR_NONE) {
 108     grpc_timer_cancel(&connection_state->timer);
 109   }
 110   server_connection_state_unref(connection_state);
 111 }
 112
 113 static void on_handshake_done(void* arg, grpc_error* error) {
 114   auto* args = static_cast<grpc_core::HandshakerArgs*>(arg);
 115   server_connection_state* connection_state =
 116       static_cast<server_connection_state*>(args->user_data);
 117   gpr_mu_lock(&connection_state->svr_state->mu);
 118   grpc_resource_user* resource_user = grpc_server_get_default_resource_user(
 119       connection_state->svr_state->server);
 120   if (error != GRPC_ERROR_NONE || connection_state->svr_state->shutdown) {
 121     const char* error_str = grpc_error_string(error);
 122     gpr_log(GPR_DEBUG, "Handshaking failed: %s", error_str);
 123     grpc_resource_user* resource_user = grpc_server_get_default_resource_user(
 124         connection_state->svr_state->server);
 125     if (resource_user != nullptr) {
 126       grpc_resource_user_free(resource_user, GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
 127     }
 128     if (error == GRPC_ERROR_NONE && args->endpoint != nullptr) {
 129       // We were shut down after handshaking completed successfully, so
 130       // destroy the endpoint here.
 131       // TODO(ctiller): It is currently necessary to shutdown endpoints
 132       // before destroying them, even if we know that there are no
 133       // pending read/write callbacks.  This should be fixed, at which
 134       // point this can be removed.
 135       grpc_endpoint_shutdown(args->endpoint, GRPC_ERROR_NONE);
 136       grpc_endpoint_destroy(args->endpoint);
 137       grpc_channel_args_destroy(args->args);
 138       grpc_slice_buffer_destroy_internal(args->read_buffer);
 139       gpr_free(args->read_buffer);
 140     }
 141   } else {
 142     // If the handshaking succeeded but there is no endpoint, then the
 143     // handshaker may have handed off the connection to some external
 144     // code, so we can just clean up here without creating a transport.
 145     if (args->endpoint != nullptr) {
 146       grpc_transport* transport = grpc_create_chttp2_transport(
 147           args->args, args->endpoint, false, resource_user);
 148       grpc_server_setup_transport(
 149           connection_state->svr_state->server, transport,
 150           connection_state->accepting_pollset, args->args,
 151           grpc_chttp2_transport_get_socket_node(transport), resource_user);
 152       // Use notify_on_receive_settings callback to enforce the
 153       // handshake deadline.
 154       connection_state->transport =
 155           reinterpret_cast<grpc_chttp2_transport*>(transport);
 156       gpr_ref(&connection_state->refs);
 157       GRPC_CLOSURE_INIT(&connection_state->on_receive_settings,
 158                         on_receive_settings, connection_state,
 159                         grpc_schedule_on_exec_ctx);
 160       grpc_chttp2_transport_start_reading(
 161           transport, args->read_buffer, &connection_state->on_receive_settings);
 162       grpc_channel_args_destroy(args->args);
 163       gpr_ref(&connection_state->refs);
 164       GRPC_CHTTP2_REF_TRANSPORT((grpc_chttp2_transport*)transport,
 165                                 "receive settings timeout");
 166       GRPC_CLOSURE_INIT(&connection_state->on_timeout, on_timeout,
 167                         connection_state, grpc_schedule_on_exec_ctx);
 168       grpc_timer_init(&connection_state->timer, connection_state->deadline,
 169                       &connection_state->on_timeout);
 170     } else {
 171       if (resource_user != nullptr) {
 172         grpc_resource_user_free(resource_user,
 173                                 GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
 174       }
 175     }
 176   }
 177   connection_state->handshake_mgr->RemoveFromPendingMgrList(
 178       &connection_state->svr_state->pending_handshake_mgrs);
 179   gpr_mu_unlock(&connection_state->svr_state->mu);
 180   connection_state->handshake_mgr.reset();
 181   gpr_free(connection_state->acceptor);
 182   grpc_tcp_server_unref(connection_state->svr_state->tcp_server);
 183   server_connection_state_unref(connection_state);
 184 }
 185
 186 static void on_accept(void* arg, grpc_endpoint* tcp,
 187                       grpc_pollset* accepting_pollset,
 188                       grpc_tcp_server_acceptor* acceptor) {
 189   server_state* state = static_cast<server_state*>(arg);
 190   gpr_mu_lock(&state->mu);
 191   if (state->shutdown) {
 192     gpr_mu_unlock(&state->mu);
 193     grpc_endpoint_shutdown(tcp, GRPC_ERROR_NONE);
 194     grpc_endpoint_destroy(tcp);
 195     gpr_free(acceptor);
 196     return;
 197   }
 198   grpc_resource_user* resource_user =
 199       grpc_server_get_default_resource_user(state->server);
 200   if (resource_user != nullptr &&
 201       !grpc_resource_user_safe_alloc(resource_user,
 202                                      GRPC_RESOURCE_QUOTA_CHANNEL_SIZE)) {
 203     gpr_log(
 204         GPR_ERROR,
 205         "Memory quota exhausted, rejecting the connection, no handshaking.");
 206     gpr_mu_unlock(&state->mu);
 207     grpc_endpoint_shutdown(tcp, GRPC_ERROR_NONE);
 208     grpc_endpoint_destroy(tcp);
 209     gpr_free(acceptor);
 210     return;
 211   }
 212   auto handshake_mgr = grpc_core::MakeRefCounted<grpc_core::HandshakeManager>();
 213   handshake_mgr->AddToPendingMgrList(&state->pending_handshake_mgrs);
 214   grpc_tcp_server_ref(state->tcp_server);
 215   gpr_mu_unlock(&state->mu);
 216   server_connection_state* connection_state =
 217       static_cast<server_connection_state*>(
 218           gpr_zalloc(sizeof(*connection_state)));
 219   gpr_ref_init(&connection_state->refs, 1);
 220   connection_state->svr_state = state;
 221   connection_state->accepting_pollset = accepting_pollset;
 222   connection_state->acceptor = acceptor;
 223   connection_state->handshake_mgr = handshake_mgr;
 224   connection_state->interested_parties = grpc_pollset_set_create();
 225   grpc_pollset_set_add_pollset(connection_state->interested_parties,
 226                                connection_state->accepting_pollset);
 227   grpc_core::HandshakerRegistry::AddHandshakers(
 228       grpc_core::HANDSHAKER_SERVER, state->args,
 229       connection_state->interested_parties,
 230       connection_state->handshake_mgr.get());
 231   const grpc_arg* timeout_arg =
 232       grpc_channel_args_find(state->args, GRPC_ARG_SERVER_HANDSHAKE_TIMEOUT_MS);
 233   connection_state->deadline =
 234       grpc_core::ExecCtx::Get()->Now() +
 235       grpc_channel_arg_get_integer(timeout_arg,
 236                                    {120 * GPR_MS_PER_SEC, 1, INT_MAX});
 237   connection_state->handshake_mgr->DoHandshake(
 238       tcp, state->args, connection_state->deadline, acceptor, on_handshake_done,
 239       connection_state);
 240 }
 241
 242 /* Server callback: start listening on our ports */
 243 static void server_start_listener(grpc_server* /*server*/, void* arg,
 244                                   grpc_pollset** pollsets,
 245                                   size_t pollset_count) {
 246   server_state* state = static_cast<server_state*>(arg);
 247   gpr_mu_lock(&state->mu);
 248   state->shutdown = false;
 249   gpr_mu_unlock(&state->mu);
 250   grpc_tcp_server_start(state->tcp_server, pollsets, pollset_count, on_accept,
 251                         state);
 252 }
 253
 254 static void tcp_server_shutdown_complete(void* arg, grpc_error* error) {
 255   server_state* state = static_cast<server_state*>(arg);
 256   /* ensure all threads have unlocked */
 257   gpr_mu_lock(&state->mu);
 258   grpc_closure* destroy_done = state->server_destroy_listener_done;
 259   GPR_ASSERT(state->shutdown);
 260   if (state->pending_handshake_mgrs != nullptr) {
 261     state->pending_handshake_mgrs->ShutdownAllPending(GRPC_ERROR_REF(error));
 262   }
 263   state->channelz_listen_socket.reset();
 264   gpr_mu_unlock(&state->mu);
 265   // Flush queued work before destroying handshaker factory, since that
 266   // may do a synchronous unref.
 267   grpc_core::ExecCtx::Get()->Flush();
 268   if (destroy_done != nullptr) {
 269     grpc_core::ExecCtx::Run(DEBUG_LOCATION, destroy_done,
 270                             GRPC_ERROR_REF(error));
 271     grpc_core::ExecCtx::Get()->Flush();
 272   }
 273   grpc_channel_args_destroy(state->args);
 274   gpr_mu_destroy(&state->mu);
 275   gpr_free(state);
 276 }
 277
 278 /* Server callback: destroy the tcp listener (so we don't generate further
 279    callbacks) */
 280 static void server_destroy_listener(grpc_server* /*server*/, void* arg,
 281                                     grpc_closure* destroy_done) {
 282   server_state* state = static_cast<server_state*>(arg);
 283   gpr_mu_lock(&state->mu);
 284   state->shutdown = true;
 285   state->server_destroy_listener_done = destroy_done;
 286   grpc_tcp_server* tcp_server = state->tcp_server;
 287   gpr_mu_unlock(&state->mu);
 288   grpc_tcp_server_shutdown_listeners(tcp_server);
 289   grpc_tcp_server_unref(tcp_server);
 290 }
 291
 292 static grpc_error* chttp2_server_add_acceptor(grpc_server* server,
 293                                               const char* name,
 294                                               grpc_channel_args* args) {
 295   grpc_tcp_server* tcp_server = nullptr;
 296   grpc_error* err = GRPC_ERROR_NONE;
 297   server_state* state = nullptr;
 298   const grpc_arg* arg = nullptr;
 299   grpc_core::TcpServerFdHandler** arg_val = nullptr;
 300   state = static_cast<server_state*>(gpr_zalloc(sizeof(*state)));
 301   GRPC_CLOSURE_INIT(&state->tcp_server_shutdown_complete,
 302                     tcp_server_shutdown_complete, state,
 303                     grpc_schedule_on_exec_ctx);
 304   err = grpc_tcp_server_create(&state->tcp_server_shutdown_complete, args,
 305                                &tcp_server);
 306   if (err != GRPC_ERROR_NONE) {
 307     goto error;
 308   }
 309   state->server = server;
 310   state->tcp_server = tcp_server;
 311   state->args = args;
 312   state->shutdown = true;
 313   gpr_mu_init(&state->mu);
 314   // TODO(yangg) channelz
 315   arg = grpc_channel_args_find(args, name);
 316   GPR_ASSERT(arg->type == GRPC_ARG_POINTER);
 317   arg_val = static_cast<grpc_core::TcpServerFdHandler**>(arg->value.pointer.p);
 318   *arg_val = grpc_tcp_server_create_fd_handler(tcp_server);
 319
 320   grpc_server_add_listener(server, state, server_start_listener,
 321                            server_destroy_listener, /* node */ nullptr);
 322   return err;
 323
 324 /* Error path: cleanup and return */
 325 error:
 326   GPR_ASSERT(err != GRPC_ERROR_NONE);
 327   if (tcp_server) {
 328     grpc_tcp_server_unref(tcp_server);
 329   } else {
 330     grpc_channel_args_destroy(args);
 331     gpr_free(state);
 332   }
 333   return err;
 334 }
 335
 336 grpc_error* grpc_chttp2_server_add_port(grpc_server* server, const char* addr,
 337                                         grpc_channel_args* args,
 338                                         int* port_num) {
 339   grpc_resolved_addresses* resolved = nullptr;
 340   grpc_tcp_server* tcp_server = nullptr;
 341   size_t i;
 342   size_t count = 0;
 343   int port_temp;
 344   grpc_error* err = GRPC_ERROR_NONE;
 345   server_state* state = nullptr;
 346   grpc_error** errors = nullptr;
 347   size_t naddrs = 0;
 348   const grpc_arg* arg = nullptr;
 349
 350   *port_num = -1;
 351
 352   if (strncmp(addr, "external:", 9) == 0) {
 353     return chttp2_server_add_acceptor(server, addr, args);
 354   }
 355
 356   /* resolve address */
 357   err = grpc_blocking_resolve_address(addr, "https", &resolved);
 358   if (err != GRPC_ERROR_NONE) {
 359     goto error;
 360   }
 361   state = static_cast<server_state*>(gpr_zalloc(sizeof(*state)));
 362   GRPC_CLOSURE_INIT(&state->tcp_server_shutdown_complete,
 363                     tcp_server_shutdown_complete, state,
 364                     grpc_schedule_on_exec_ctx);
 365   err = grpc_tcp_server_create(&state->tcp_server_shutdown_complete, args,
 366                                &tcp_server);
 367   if (err != GRPC_ERROR_NONE) {
 368     goto error;
 369   }
 370
 371   state->server = server;
 372   state->tcp_server = tcp_server;
 373   state->args = args;
 374   state->shutdown = true;
 375   gpr_mu_init(&state->mu);
 376
 377   naddrs = resolved->naddrs;
 378   errors = static_cast<grpc_error**>(gpr_malloc(sizeof(*errors) * naddrs));
 379   for (i = 0; i < naddrs; i++) {
 380     errors[i] =
 381         grpc_tcp_server_add_port(tcp_server, &resolved->addrs[i], &port_temp);
 382     if (errors[i] == GRPC_ERROR_NONE) {
 383       if (*port_num == -1) {
 384         *port_num = port_temp;
 385       } else {
 386         GPR_ASSERT(*port_num == port_temp);
 387       }
 388       count++;
 389     }
 390   }
 391   if (count == 0) {
 392     char* msg;
 393     gpr_asprintf(&msg, "No address added out of total %" PRIuPTR " resolved",
 394                  naddrs);
 395     err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
 396     gpr_free(msg);
 397     goto error;
 398   } else if (count != naddrs) {
 399     char* msg;
 400     gpr_asprintf(&msg,
 401                  "Only %" PRIuPTR " addresses added out of total %" PRIuPTR
 402                  " resolved",
 403                  count, naddrs);
 404     err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
 405     gpr_free(msg);
 406
 407     const char* warning_message = grpc_error_string(err);
 408     gpr_log(GPR_INFO, "WARNING: %s", warning_message);
 409
 410     /* we managed to bind some addresses: continue */
 411   }
 412   grpc_resolved_addresses_destroy(resolved);
 413
 414   arg = grpc_channel_args_find(args, GRPC_ARG_ENABLE_CHANNELZ);
 415   if (grpc_channel_arg_get_bool(arg, GRPC_ENABLE_CHANNELZ_DEFAULT)) {
 416     char* socket_name = nullptr;
 417     gpr_asprintf(&socket_name, "chttp2 listener %s", addr);
 418     state->channelz_listen_socket =
 419         grpc_core::MakeRefCounted<grpc_core::channelz::ListenSocketNode>(
 420             addr, socket_name);
 421     // TODO(veblush): Remove this once gpr_asprintf is replaced by
 422     // absl::StrFormat
 423     gpr_free(socket_name);
 424   }
 425
 426   /* Register with the server only upon success */
 427   grpc_server_add_listener(server, state, server_start_listener,
 428                            server_destroy_listener,
 429                            state->channelz_listen_socket);
 430   goto done;
 431
 432 /* Error path: cleanup and return */
 433 error:
 434   GPR_ASSERT(err != GRPC_ERROR_NONE);
 435   if (resolved) {
 436     grpc_resolved_addresses_destroy(resolved);
 437   }
 438   if (tcp_server) {
 439     grpc_tcp_server_unref(tcp_server);
 440   } else {
 441     grpc_channel_args_destroy(args);
 442     gpr_free(state);
 443   }
 444   *port_num = 0;
 445
 446 done:
 447   if (errors != nullptr) {
 448     for (i = 0; i < naddrs; i++) {
 449       GRPC_ERROR_UNREF(errors[i]);
 450     }
 451     gpr_free(errors);
 452   }
 453   return err;
 454 }