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