1 2 /* 3 * Copyright (C) Igor Sysoev 4 * Copyright (C) NGINX, Inc. 5 */ 6 7 #include <nxt_main.h> 8 9 10 /* 11 * A listen socket handler calls an event facility specific io_accept() 12 * method. The method accept()s a new connection and then calls 13 * nxt_event_conn_accept() to handle the new connection and to prepare 14 * for a next connection to avoid just dropping next accept()ed socket 15 * if no more connections allowed. If there are no available connections 16 * an idle connection would be closed. If there are no idle connections 17 * then new connections will not be accept()ed for 1 second. 18 */ 19 20 21 static nxt_conn_t *nxt_conn_accept_alloc(nxt_task_t *task, 22 nxt_listen_event_t *lev); 23 static void nxt_conn_listen_handler(nxt_task_t *task, void *obj, 24 void *data); 25 static nxt_conn_t *nxt_conn_accept_next(nxt_task_t *task, 26 nxt_listen_event_t *lev); 27 static nxt_int_t nxt_conn_accept_close_idle(nxt_task_t *task, 28 nxt_listen_event_t *lev); 29 static void nxt_conn_listen_event_error(nxt_task_t *task, void *obj, 30 void *data); 31 static void nxt_conn_listen_timer_handler(nxt_task_t *task, void *obj, 32 void *data); 33 34 35 nxt_listen_event_t * 36 nxt_listen_event(nxt_task_t *task, nxt_listen_socket_t *ls) 37 { 38 nxt_listen_event_t *lev; 39 nxt_event_engine_t *engine; 40 41 lev = nxt_zalloc(sizeof(nxt_listen_event_t)); 42 43 if (nxt_fast_path(lev != NULL)) { 44 lev->socket.fd = ls->socket; 45 46 engine = task->thread->engine; 47 lev->batch = engine->batch; 48 49 lev->mem_cache = (uint32_t) -1; 50 51 lev->socket.read_work_queue = &engine->accept_work_queue; 52 lev->socket.read_handler = nxt_conn_listen_handler; 53 lev->socket.error_handler = nxt_conn_listen_event_error; 54 lev->socket.log = &nxt_main_log; 55 56 lev->accept = engine->event.io->accept; 57 58 lev->listen = ls; 59 lev->work_queue = &engine->read_work_queue; 60 61 lev->timer.work_queue = &engine->fast_work_queue; 62 lev->timer.handler = nxt_conn_listen_timer_handler; 63 lev->timer.log = &nxt_main_log; 64 65 lev->task.thread = task->thread; 66 lev->task.log = &nxt_main_log; 67 lev->task.ident = nxt_task_next_ident(); 68 lev->socket.task = &lev->task; 69 lev->timer.task = &lev->task; 70 71 if (nxt_conn_accept_alloc(task, lev) != NULL) { 72 nxt_fd_event_enable_accept(engine, &lev->socket); 73 74 nxt_queue_insert_tail(&engine->listen_connections, &lev->link); 75 } 76 77 return lev; 78 } 79 80 return NULL; 81 } 82 83 84 static nxt_conn_t * 85 nxt_conn_accept_alloc(nxt_task_t *task, nxt_listen_event_t *lev) 86 { 87 nxt_mp_t *mp; 88 nxt_conn_t *c; 89 nxt_event_engine_t *engine; 90 91 engine = task->thread->engine; 92 93 if (engine->connections < engine->max_connections) { 94 95 mp = nxt_mp_create(1024, 128, 256, 32); 96 97 if (nxt_fast_path(mp != NULL)) { 98 c = nxt_conn_create(mp, lev->socket.task); 99 if (nxt_slow_path(c == NULL)) { 100 goto fail; 101 } 102 103 lev->next = c; 104 c->socket.read_work_queue = lev->socket.read_work_queue; 105 c->socket.write_ready = 1; 106 c->listen = lev; 107 108 c->remote = nxt_sockaddr_cache_alloc(engine, lev); 109 if (nxt_fast_path(c->remote != NULL)) { 110 return c; 111 } 112 } 113 114 fail: 115 116 nxt_mp_destroy(mp); 117 } 118 119 return NULL; 120 } 121 122 123 static void 124 nxt_conn_listen_handler(nxt_task_t *task, void *obj, void *data) 125 { 126 nxt_listen_event_t *lev; 127 128 lev = obj; 129 lev->ready = lev->batch; 130 131 lev->accept(task, lev, data); 132 } 133 134 135 void 136 nxt_conn_io_accept(nxt_task_t *task, void *obj, void *data) 137 { 138 socklen_t socklen; 139 nxt_conn_t *c; 140 nxt_socket_t s; 141 struct sockaddr *sa; 142 nxt_listen_event_t *lev; 143 144 lev = obj; 145 c = lev->next; 146 147 lev->ready--; 148 lev->socket.read_ready = (lev->ready != 0); 149 150 sa = &c->remote->u.sockaddr; 151 socklen = c->remote->socklen; 152 /* 153 * The returned socklen is ignored here, because sockaddr_in and 154 * sockaddr_in6 socklens are not changed. As to unspecified sockaddr_un 155 * it is 3 byte length and already prepared, because old BSDs return zero 156 * socklen and do not update the sockaddr_un at all; Linux returns 2 byte 157 * socklen and updates only the sa_family part; other systems copy 3 bytes 158 * and truncate surplus zero part. Only bound sockaddr_un will be really 159 * truncated here. 160 */ 161 s = accept(lev->socket.fd, sa, &socklen); 162 163 if (s == -1) { 164 nxt_conn_accept_error(task, lev, "accept", nxt_socket_errno); 165 return; 166 } 167 168 c->socket.fd = s; 169 170 #if (NXT_LINUX) 171 /* 172 * Linux does not inherit non-blocking mode 173 * from listen socket for accept()ed socket. 174 */ 175 if (nxt_slow_path(nxt_socket_nonblocking(task, s) != NXT_OK)) { 176 nxt_socket_close(task, s); 177 } 178 179 #endif 180 181 nxt_debug(task, "accept(%d): %d", lev->socket.fd, s); 182 183 nxt_conn_accept(task, lev, c); 184 } 185 186 187 void 188 nxt_conn_accept(nxt_task_t *task, nxt_listen_event_t *lev, nxt_conn_t *c) 189 { 190 nxt_conn_t *next; 191 192 nxt_sockaddr_text(c->remote); 193 194 nxt_debug(task, "client: %*s", 195 c->remote->address_length, nxt_sockaddr_address(c->remote)); 196 197 nxt_queue_insert_head(&task->thread->engine->idle_connections, &c->link); 198 199 c->read_work_queue = lev->work_queue; 200 c->write_work_queue = lev->work_queue; 201 202 if (lev->listen->read_after_accept) { 203 204 //c->socket.read_ready = 1; 205 // lev->listen->handler(task, c, lev->socket.data); 206 nxt_work_queue_add(c->read_work_queue, lev->listen->handler, 207 &c->task, c, lev->socket.data); 208 209 } else { 210 nxt_work_queue_add(c->write_work_queue, lev->listen->handler, 211 &c->task, c, lev->socket.data); 212 } 213 214 next = nxt_conn_accept_next(task, lev); 215 216 if (next != NULL && lev->socket.read_ready) { 217 nxt_work_queue_add(lev->socket.read_work_queue, 218 lev->accept, task, lev, next); 219 } 220 } 221 222 223 static nxt_conn_t * 224 nxt_conn_accept_next(nxt_task_t *task, nxt_listen_event_t *lev) 225 { 226 nxt_conn_t *c; 227 228 lev->next = NULL; 229 230 do { 231 c = nxt_conn_accept_alloc(task, lev); 232 233 if (nxt_fast_path(c != NULL)) { 234 return c; 235 } 236 237 } while (nxt_conn_accept_close_idle(task, lev) == NXT_OK); 238 239 nxt_log(task, NXT_LOG_CRIT, "no available connections, " 240 "new connections are not accepted within 1s"); 241 242 return NULL; 243 } 244 245 246 static nxt_int_t 247 nxt_conn_accept_close_idle(nxt_task_t *task, nxt_listen_event_t *lev) 248 { 249 nxt_conn_t *c; 250 nxt_queue_t *idle; 251 nxt_queue_link_t *link; 252 nxt_event_engine_t *engine; 253 254 static nxt_log_moderation_t nxt_idle_close_log_moderation = { 255 NXT_LOG_INFO, 2, "idle connections closed", NXT_LOG_MODERATION 256 }; 257 258 engine = task->thread->engine; 259 260 idle = &engine->idle_connections; 261 262 for (link = nxt_queue_last(idle); 263 link != nxt_queue_head(idle); 264 link = nxt_queue_next(link)) 265 { 266 c = nxt_queue_link_data(link, nxt_conn_t, link); 267 268 if (!c->socket.read_ready) { 269 nxt_log_moderate(&nxt_idle_close_log_moderation, NXT_LOG_INFO, 270 task->log, "no available connections, " 271 "close idle connection"); 272 nxt_queue_remove(link); 273 nxt_conn_close(engine, c); 274 275 return NXT_OK; 276 } 277 } 278 279 nxt_timer_add(engine, &lev->timer, 1000); 280 281 nxt_fd_event_disable_read(engine, &lev->socket); 282 283 return NXT_DECLINED; 284 } 285 286 287 void 288 nxt_conn_accept_error(nxt_task_t *task, nxt_listen_event_t *lev, 289 const char *accept_syscall, nxt_err_t err) 290 { 291 static nxt_log_moderation_t nxt_accept_log_moderation = { 292 NXT_LOG_INFO, 2, "accept() failed", NXT_LOG_MODERATION 293 }; 294 295 lev->socket.read_ready = 0; 296 297 switch (err) { 298 299 case NXT_EAGAIN: 300 nxt_debug(task, "%s(%d) %E", accept_syscall, lev->socket.fd, err); 301 return; 302 303 case ECONNABORTED: 304 nxt_log_moderate(&nxt_accept_log_moderation, NXT_LOG_WARN, 305 task->log, "%s(%d) failed %E", 306 accept_syscall, lev->socket.fd, err); 307 return; 308 309 case EMFILE: 310 case ENFILE: 311 case ENOBUFS: 312 case ENOMEM: 313 if (nxt_conn_accept_close_idle(task, lev) != NXT_OK) { 314 nxt_log(task, NXT_LOG_CRIT, "%s(%d) failed %E, " 315 "new connections are not accepted within 1s", 316 accept_syscall, lev->socket.fd, err); 317 } 318 319 return; 320 321 default: 322 nxt_log(task, NXT_LOG_CRIT, "%s(%d) failed %E", 323 accept_syscall, lev->socket.fd, err); 324 return; 325 } 326 } 327 328 329 static void 330 nxt_conn_listen_timer_handler(nxt_task_t *task, void *obj, void *data) 331 { 332 nxt_conn_t *c; 333 nxt_timer_t *timer; 334 nxt_listen_event_t *lev; 335 336 timer = obj; 337 338 lev = nxt_timer_data(timer, nxt_listen_event_t, timer); 339 c = lev->next; 340 341 if (c == NULL) { 342 c = nxt_conn_accept_next(task, lev); 343 344 if (c == NULL) { 345 return; 346 } 347 } 348 349 nxt_fd_event_enable_accept(task->thread->engine, &lev->socket); 350 351 lev->accept(task, lev, c); 352 } 353 354 355 static void 356 nxt_conn_listen_event_error(nxt_task_t *task, void *obj, void *data) 357 { 358 nxt_fd_event_t *ev; 359 360 ev = obj; 361 362 nxt_log(task, NXT_LOG_CRIT, "accept(%d) event error", ev->fd); 363 } 364