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