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 <string.h> 22 23 #include <grpc/support/alloc.h> 24 #include <grpc/support/log.h> 25 #include <grpc/support/string_util.h> 26 27 #include "src/core/lib/channel/channel_args.h" 28 #include "src/core/lib/channel/handshaker.h" 29 #include "src/core/lib/debug/trace.h" 30 #include "src/core/lib/iomgr/timer.h" 31 #include "src/core/lib/slice/slice_internal.h" 32 33 grpc_core::TraceFlag grpc_handshaker_trace(false, "handshaker"); 34 35 // 36 // grpc_handshaker 37 // 38 39 void grpc_handshaker_init(const grpc_handshaker_vtable* vtable, 40 grpc_handshaker* handshaker) { 41 handshaker->vtable = vtable; 42 } 43 44 void grpc_handshaker_destroy(grpc_handshaker* handshaker) { 45 handshaker->vtable->destroy(handshaker); 46 } 47 48 void grpc_handshaker_shutdown(grpc_handshaker* handshaker, grpc_error* why) { 49 handshaker->vtable->shutdown(handshaker, why); 50 } 51 52 void grpc_handshaker_do_handshake(grpc_handshaker* handshaker, 53 grpc_tcp_server_acceptor* acceptor, 54 grpc_closure* on_handshake_done, 55 grpc_handshaker_args* args) { 56 handshaker->vtable->do_handshake(handshaker, acceptor, on_handshake_done, 57 args); 58 } 59 60 const char* grpc_handshaker_name(grpc_handshaker* handshaker) { 61 return handshaker->vtable->name; 62 } 63 64 // 65 // grpc_handshake_manager 66 // 67 68 struct grpc_handshake_manager { 69 gpr_mu mu; 70 gpr_refcount refs; 71 bool shutdown; 72 // An array of handshakers added via grpc_handshake_manager_add(). 73 size_t count; 74 grpc_handshaker** handshakers; 75 // The index of the handshaker to invoke next and closure to invoke it. 76 size_t index; 77 grpc_closure call_next_handshaker; 78 // The acceptor to call the handshakers with. 79 grpc_tcp_server_acceptor* acceptor; 80 // Deadline timer across all handshakers. 81 grpc_timer deadline_timer; 82 grpc_closure on_timeout; 83 // The final callback and user_data to invoke after the last handshaker. 84 grpc_closure on_handshake_done; 85 void* user_data; 86 // Handshaker args. 87 grpc_handshaker_args args; 88 // Links to the previous and next managers in a list of all pending handshakes 89 // Used at server side only. 90 grpc_handshake_manager* prev; 91 grpc_handshake_manager* next; 92 }; 93 94 grpc_handshake_manager* grpc_handshake_manager_create() { 95 grpc_handshake_manager* mgr = static_cast<grpc_handshake_manager*>( 96 gpr_zalloc(sizeof(grpc_handshake_manager))); 97 gpr_mu_init(&mgr->mu); 98 gpr_ref_init(&mgr->refs, 1); 99 return mgr; 100 } 101 102 void grpc_handshake_manager_pending_list_add(grpc_handshake_manager** head, 103 grpc_handshake_manager* mgr) { 104 GPR_ASSERT(mgr->prev == nullptr); 105 GPR_ASSERT(mgr->next == nullptr); 106 mgr->next = *head; 107 if (*head) { 108 (*head)->prev = mgr; 109 } 110 *head = mgr; 111 } 112 113 void grpc_handshake_manager_pending_list_remove(grpc_handshake_manager** head, 114 grpc_handshake_manager* mgr) { 115 if (mgr->next != nullptr) { 116 mgr->next->prev = mgr->prev; 117 } 118 if (mgr->prev != nullptr) { 119 mgr->prev->next = mgr->next; 120 } else { 121 GPR_ASSERT(*head == mgr); 122 *head = mgr->next; 123 } 124 } 125 126 void grpc_handshake_manager_pending_list_shutdown_all( 127 grpc_handshake_manager* head, grpc_error* why) { 128 while (head != nullptr) { 129 grpc_handshake_manager_shutdown(head, GRPC_ERROR_REF(why)); 130 head = head->next; 131 } 132 GRPC_ERROR_UNREF(why); 133 } 134 135 static bool is_power_of_2(size_t n) { return (n & (n - 1)) == 0; } 136 137 void grpc_handshake_manager_add(grpc_handshake_manager* mgr, 138 grpc_handshaker* handshaker) { 139 if (grpc_handshaker_trace.enabled()) { 140 gpr_log( 141 GPR_INFO, 142 "handshake_manager %p: adding handshaker %s [%p] at index %" PRIuPTR, 143 mgr, grpc_handshaker_name(handshaker), handshaker, mgr->count); 144 } 145 gpr_mu_lock(&mgr->mu); 146 // To avoid allocating memory for each handshaker we add, we double 147 // the number of elements every time we need more. 148 size_t realloc_count = 0; 149 if (mgr->count == 0) { 150 realloc_count = 2; 151 } else if (mgr->count >= 2 && is_power_of_2(mgr->count)) { 152 realloc_count = mgr->count * 2; 153 } 154 if (realloc_count > 0) { 155 mgr->handshakers = static_cast<grpc_handshaker**>(gpr_realloc( 156 mgr->handshakers, realloc_count * sizeof(grpc_handshaker*))); 157 } 158 mgr->handshakers[mgr->count++] = handshaker; 159 gpr_mu_unlock(&mgr->mu); 160 } 161 162 static void grpc_handshake_manager_unref(grpc_handshake_manager* mgr) { 163 if (gpr_unref(&mgr->refs)) { 164 for (size_t i = 0; i < mgr->count; ++i) { 165 grpc_handshaker_destroy(mgr->handshakers[i]); 166 } 167 gpr_free(mgr->handshakers); 168 gpr_mu_destroy(&mgr->mu); 169 gpr_free(mgr); 170 } 171 } 172 173 void grpc_handshake_manager_destroy(grpc_handshake_manager* mgr) { 174 grpc_handshake_manager_unref(mgr); 175 } 176 177 void grpc_handshake_manager_shutdown(grpc_handshake_manager* mgr, 178 grpc_error* why) { 179 gpr_mu_lock(&mgr->mu); 180 // Shutdown the handshaker that's currently in progress, if any. 181 if (!mgr->shutdown && mgr->index > 0) { 182 mgr->shutdown = true; 183 grpc_handshaker_shutdown(mgr->handshakers[mgr->index - 1], 184 GRPC_ERROR_REF(why)); 185 } 186 gpr_mu_unlock(&mgr->mu); 187 GRPC_ERROR_UNREF(why); 188 } 189 190 static char* handshaker_args_string(grpc_handshaker_args* args) { 191 char* args_str = grpc_channel_args_string(args->args); 192 size_t num_args = args->args != nullptr ? args->args->num_args : 0; 193 size_t read_buffer_length = 194 args->read_buffer != nullptr ? args->read_buffer->length : 0; 195 char* str; 196 gpr_asprintf(&str, 197 "{endpoint=%p, args=%p {size=%" PRIuPTR 198 ": %s}, read_buffer=%p (length=%" PRIuPTR "), exit_early=%d}", 199 args->endpoint, args->args, num_args, args_str, 200 args->read_buffer, read_buffer_length, args->exit_early); 201 gpr_free(args_str); 202 return str; 203 } 204 205 // Helper function to call either the next handshaker or the 206 // on_handshake_done callback. 207 // Returns true if we've scheduled the on_handshake_done callback. 208 static bool call_next_handshaker_locked(grpc_handshake_manager* mgr, 209 grpc_error* error) { 210 if (grpc_handshaker_trace.enabled()) { 211 char* args_str = handshaker_args_string(&mgr->args); 212 gpr_log(GPR_INFO, 213 "handshake_manager %p: error=%s shutdown=%d index=%" PRIuPTR 214 ", args=%s", 215 mgr, grpc_error_string(error), mgr->shutdown, mgr->index, args_str); 216 gpr_free(args_str); 217 } 218 GPR_ASSERT(mgr->index <= mgr->count); 219 // If we got an error or we've been shut down or we're exiting early or 220 // we've finished the last handshaker, invoke the on_handshake_done 221 // callback. Otherwise, call the next handshaker. 222 if (error != GRPC_ERROR_NONE || mgr->shutdown || mgr->args.exit_early || 223 mgr->index == mgr->count) { 224 if (error == GRPC_ERROR_NONE && mgr->shutdown) { 225 error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("handshaker shutdown"); 226 // It is possible that the endpoint has already been destroyed by 227 // a shutdown call while this callback was sitting on the ExecCtx 228 // with no error. 229 if (mgr->args.endpoint != nullptr) { 230 // TODO(roth): It is currently necessary to shutdown endpoints 231 // before destroying then, even when we know that there are no 232 // pending read/write callbacks. This should be fixed, at which 233 // point this can be removed. 234 grpc_endpoint_shutdown(mgr->args.endpoint, GRPC_ERROR_REF(error)); 235 grpc_endpoint_destroy(mgr->args.endpoint); 236 mgr->args.endpoint = nullptr; 237 grpc_channel_args_destroy(mgr->args.args); 238 mgr->args.args = nullptr; 239 grpc_slice_buffer_destroy_internal(mgr->args.read_buffer); 240 gpr_free(mgr->args.read_buffer); 241 mgr->args.read_buffer = nullptr; 242 } 243 } 244 if (grpc_handshaker_trace.enabled()) { 245 gpr_log(GPR_INFO, 246 "handshake_manager %p: handshaking complete -- scheduling " 247 "on_handshake_done with error=%s", 248 mgr, grpc_error_string(error)); 249 } 250 // Cancel deadline timer, since we're invoking the on_handshake_done 251 // callback now. 252 grpc_timer_cancel(&mgr->deadline_timer); 253 GRPC_CLOSURE_SCHED(&mgr->on_handshake_done, error); 254 mgr->shutdown = true; 255 } else { 256 if (grpc_handshaker_trace.enabled()) { 257 gpr_log( 258 GPR_INFO, 259 "handshake_manager %p: calling handshaker %s [%p] at index %" PRIuPTR, 260 mgr, grpc_handshaker_name(mgr->handshakers[mgr->index]), 261 mgr->handshakers[mgr->index], mgr->index); 262 } 263 grpc_handshaker_do_handshake(mgr->handshakers[mgr->index], mgr->acceptor, 264 &mgr->call_next_handshaker, &mgr->args); 265 } 266 ++mgr->index; 267 return mgr->shutdown; 268 } 269 270 // A function used as the handshaker-done callback when chaining 271 // handshakers together. 272 static void call_next_handshaker(void* arg, grpc_error* error) { 273 grpc_handshake_manager* mgr = static_cast<grpc_handshake_manager*>(arg); 274 gpr_mu_lock(&mgr->mu); 275 bool done = call_next_handshaker_locked(mgr, GRPC_ERROR_REF(error)); 276 gpr_mu_unlock(&mgr->mu); 277 // If we're invoked the final callback, we won't be coming back 278 // to this function, so we can release our reference to the 279 // handshake manager. 280 if (done) { 281 grpc_handshake_manager_unref(mgr); 282 } 283 } 284 285 // Callback invoked when deadline is exceeded. 286 static void on_timeout(void* arg, grpc_error* error) { 287 grpc_handshake_manager* mgr = static_cast<grpc_handshake_manager*>(arg); 288 if (error == GRPC_ERROR_NONE) { // Timer fired, rather than being cancelled. 289 grpc_handshake_manager_shutdown( 290 mgr, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Handshake timed out")); 291 } 292 grpc_handshake_manager_unref(mgr); 293 } 294 295 void grpc_handshake_manager_do_handshake( 296 grpc_handshake_manager* mgr, grpc_pollset_set* interested_parties, 297 grpc_endpoint* endpoint, const grpc_channel_args* channel_args, 298 grpc_millis deadline, grpc_tcp_server_acceptor* acceptor, 299 grpc_iomgr_cb_func on_handshake_done, void* user_data) { 300 gpr_mu_lock(&mgr->mu); 301 GPR_ASSERT(mgr->index == 0); 302 GPR_ASSERT(!mgr->shutdown); 303 // Construct handshaker args. These will be passed through all 304 // handshakers and eventually be freed by the on_handshake_done callback. 305 mgr->args.interested_parties = interested_parties; 306 mgr->args.endpoint = endpoint; 307 mgr->args.args = grpc_channel_args_copy(channel_args); 308 mgr->args.user_data = user_data; 309 mgr->args.read_buffer = static_cast<grpc_slice_buffer*>( 310 gpr_malloc(sizeof(*mgr->args.read_buffer))); 311 grpc_slice_buffer_init(mgr->args.read_buffer); 312 // Initialize state needed for calling handshakers. 313 mgr->acceptor = acceptor; 314 GRPC_CLOSURE_INIT(&mgr->call_next_handshaker, call_next_handshaker, mgr, 315 grpc_schedule_on_exec_ctx); 316 GRPC_CLOSURE_INIT(&mgr->on_handshake_done, on_handshake_done, &mgr->args, 317 grpc_schedule_on_exec_ctx); 318 // Start deadline timer, which owns a ref. 319 gpr_ref(&mgr->refs); 320 GRPC_CLOSURE_INIT(&mgr->on_timeout, on_timeout, mgr, 321 grpc_schedule_on_exec_ctx); 322 grpc_timer_init(&mgr->deadline_timer, deadline, &mgr->on_timeout); 323 // Start first handshaker, which also owns a ref. 324 gpr_ref(&mgr->refs); 325 bool done = call_next_handshaker_locked(mgr, GRPC_ERROR_NONE); 326 gpr_mu_unlock(&mgr->mu); 327 if (done) { 328 grpc_handshake_manager_unref(mgr); 329 } 330 } 331
