release/src/router/nginx/src/event/ngx_event_accept.c

   1
   2 /*
   3  * Copyright (C) Igor Sysoev
   4  * Copyright (C) Nginx, Inc.
   5  */
   6
   7
   8 #include <ngx_config.h>
   9 #include <ngx_core.h>
  10 #include <ngx_event.h>
  11
  12
  13 static ngx_int_t ngx_enable_accept_events(ngx_cycle_t *cycle);
  14 static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle);
  15 static void ngx_close_accepted_connection(ngx_connection_t *c);
  16
  17
  18 void
  19 ngx_event_accept(ngx_event_t *ev)
  20 {
  21     socklen_t          socklen;
  22     ngx_err_t          err;
  23     ngx_log_t         *log;
  24     ngx_uint_t         level;
  25     ngx_socket_t       s;
  26     ngx_event_t       *rev, *wev;
  27     ngx_listening_t   *ls;
  28     ngx_connection_t  *c, *lc;
  29     ngx_event_conf_t  *ecf;
  30     u_char             sa[NGX_SOCKADDRLEN];
  31 #if (NGX_HAVE_ACCEPT4)
  32     static ngx_uint_t  use_accept4 = 1;
  33 #endif
  34
  35     if (ev->timedout) {
  36         if (ngx_enable_accept_events((ngx_cycle_t *) ngx_cycle) != NGX_OK) {
  37             return;
  38         }
  39
  40         ev->timedout = 0;
  41     }
  42
  43     ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module);
  44
  45     if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
  46         ev->available = 1;
  47
  48     } else if (!(ngx_event_flags & NGX_USE_KQUEUE_EVENT)) {
  49         ev->available = ecf->multi_accept;
  50     }
  51
  52     lc = ev->data;
  53     ls = lc->listening;
  54     ev->ready = 0;
  55
  56     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
  57                    "accept on %V, ready: %d", &ls->addr_text, ev->available);
  58
  59     do {
  60         socklen = NGX_SOCKADDRLEN;
  61
  62 #if (NGX_HAVE_ACCEPT4)
  63         if (use_accept4) {
  64             s = accept4(lc->fd, (struct sockaddr *) sa, &socklen,
  65                         SOCK_NONBLOCK);
  66         } else {
  67             s = accept(lc->fd, (struct sockaddr *) sa, &socklen);
  68         }
  69 #else
  70         s = accept(lc->fd, (struct sockaddr *) sa, &socklen);
  71 #endif
  72
  73         if (s == -1) {
  74             err = ngx_socket_errno;
  75
  76             if (err == NGX_EAGAIN) {
  77                 ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err,
  78                                "accept() not ready");
  79                 return;
  80             }
  81
  82             level = NGX_LOG_ALERT;
  83
  84             if (err == NGX_ECONNABORTED) {
  85                 level = NGX_LOG_ERR;
  86
  87             } else if (err == NGX_EMFILE || err == NGX_ENFILE) {
  88                 level = NGX_LOG_CRIT;
  89             }
  90
  91 #if (NGX_HAVE_ACCEPT4)
  92             ngx_log_error(level, ev->log, err,
  93                           use_accept4 ? "accept4() failed" : "accept() failed");
  94
  95             if (use_accept4 && err == NGX_ENOSYS) {
  96                 use_accept4 = 0;
  97                 ngx_inherited_nonblocking = 0;
  98                 continue;
  99             }
 100 #else
 101             ngx_log_error(level, ev->log, err, "accept() failed");
 102 #endif
 103
 104             if (err == NGX_ECONNABORTED) {
 105                 if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
 106                     ev->available--;
 107                 }
 108
 109                 if (ev->available) {
 110                     continue;
 111                 }
 112             }
 113
 114             if (err == NGX_EMFILE || err == NGX_ENFILE) {
 115                 if (ngx_disable_accept_events((ngx_cycle_t *) ngx_cycle)
 116                     != NGX_OK)
 117                 {
 118                     return;
 119                 }
 120
 121                 if (ngx_use_accept_mutex) {
 122                     if (ngx_accept_mutex_held) {
 123                         ngx_shmtx_unlock(&ngx_accept_mutex);
 124                         ngx_accept_mutex_held = 0;
 125                     }
 126
 127                     ngx_accept_disabled = 1;
 128
 129                 } else {
 130                     ngx_add_timer(ev, ecf->accept_mutex_delay);
 131                 }
 132             }
 133
 134             return;
 135         }
 136
 137 #if (NGX_STAT_STUB)
 138         (void) ngx_atomic_fetch_add(ngx_stat_accepted, 1);
 139 #endif
 140
 141         ngx_accept_disabled = ngx_cycle->connection_n / 8
 142                               - ngx_cycle->free_connection_n;
 143
 144         c = ngx_get_connection(s, ev->log);
 145
 146         if (c == NULL) {
 147             if (ngx_close_socket(s) == -1) {
 148                 ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno,
 149                               ngx_close_socket_n " failed");
 150             }
 151
 152             return;
 153         }
 154
 155 #if (NGX_STAT_STUB)
 156         (void) ngx_atomic_fetch_add(ngx_stat_active, 1);
 157 #endif
 158
 159         c->pool = ngx_create_pool(ls->pool_size, ev->log);
 160         if (c->pool == NULL) {
 161             ngx_close_accepted_connection(c);
 162             return;
 163         }
 164
 165         c->sockaddr = ngx_palloc(c->pool, socklen);
 166         if (c->sockaddr == NULL) {
 167             ngx_close_accepted_connection(c);
 168             return;
 169         }
 170
 171         ngx_memcpy(c->sockaddr, sa, socklen);
 172
 173         log = ngx_palloc(c->pool, sizeof(ngx_log_t));
 174         if (log == NULL) {
 175             ngx_close_accepted_connection(c);
 176             return;
 177         }
 178
 179         /* set a blocking mode for aio and non-blocking mode for others */
 180
 181         if (ngx_inherited_nonblocking) {
 182             if (ngx_event_flags & NGX_USE_AIO_EVENT) {
 183                 if (ngx_blocking(s) == -1) {
 184                     ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno,
 185                                   ngx_blocking_n " failed");
 186                     ngx_close_accepted_connection(c);
 187                     return;
 188                 }
 189             }
 190
 191         } else {
 192             if (!(ngx_event_flags & (NGX_USE_AIO_EVENT|NGX_USE_RTSIG_EVENT))) {
 193                 if (ngx_nonblocking(s) == -1) {
 194                     ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno,
 195                                   ngx_nonblocking_n " failed");
 196                     ngx_close_accepted_connection(c);
 197                     return;
 198                 }
 199             }
 200         }
 201
 202         *log = ls->log;
 203
 204         c->recv = ngx_recv;
 205         c->send = ngx_send;
 206         c->recv_chain = ngx_recv_chain;
 207         c->send_chain = ngx_send_chain;
 208
 209         c->log = log;
 210         c->pool->log = log;
 211
 212         c->socklen = socklen;
 213         c->listening = ls;
 214         c->local_sockaddr = ls->sockaddr;
 215
 216         c->unexpected_eof = 1;
 217
 218 #if (NGX_HAVE_UNIX_DOMAIN)
 219         if (c->sockaddr->sa_family == AF_UNIX) {
 220             c->tcp_nopush = NGX_TCP_NOPUSH_DISABLED;
 221             c->tcp_nodelay = NGX_TCP_NODELAY_DISABLED;
 222 #if (NGX_SOLARIS)
 223             /* Solaris's sendfilev() supports AF_NCA, AF_INET, and AF_INET6 */
 224             c->sendfile = 0;
 225 #endif
 226         }
 227 #endif
 228
 229         rev = c->read;
 230         wev = c->write;
 231
 232         wev->ready = 1;
 233
 234         if (ngx_event_flags & (NGX_USE_AIO_EVENT|NGX_USE_RTSIG_EVENT)) {
 235             /* rtsig, aio, iocp */
 236             rev->ready = 1;
 237         }
 238
 239         if (ev->deferred_accept) {
 240             rev->ready = 1;
 241 #if (NGX_HAVE_KQUEUE)
 242             rev->available = 1;
 243 #endif
 244         }
 245
 246         rev->log = log;
 247         wev->log = log;
 248
 249         /*
 250          * TODO: MT: - ngx_atomic_fetch_add()
 251          *             or protection by critical section or light mutex
 252          *
 253          * TODO: MP: - allocated in a shared memory
 254          *           - ngx_atomic_fetch_add()
 255          *             or protection by critical section or light mutex
 256          */
 257
 258         c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1);
 259
 260 #if (NGX_STAT_STUB)
 261         (void) ngx_atomic_fetch_add(ngx_stat_handled, 1);
 262 #endif
 263
 264 #if (NGX_THREADS)
 265         rev->lock = &c->lock;
 266         wev->lock = &c->lock;
 267         rev->own_lock = &c->lock;
 268         wev->own_lock = &c->lock;
 269 #endif
 270
 271         if (ls->addr_ntop) {
 272             c->addr_text.data = ngx_pnalloc(c->pool, ls->addr_text_max_len);
 273             if (c->addr_text.data == NULL) {
 274                 ngx_close_accepted_connection(c);
 275                 return;
 276             }
 277
 278             c->addr_text.len = ngx_sock_ntop(c->sockaddr, c->addr_text.data,
 279                                              ls->addr_text_max_len, 0);
 280             if (c->addr_text.len == 0) {
 281                 ngx_close_accepted_connection(c);
 282                 return;
 283             }
 284         }
 285
 286 #if (NGX_DEBUG)
 287         {
 288
 289         struct sockaddr_in   *sin;
 290         ngx_cidr_t           *cidr;
 291         ngx_uint_t            i;
 292 #if (NGX_HAVE_INET6)
 293         struct sockaddr_in6  *sin6;
 294         ngx_uint_t            n;
 295 #endif
 296
 297         cidr = ecf->debug_connection.elts;
 298         for (i = 0; i < ecf->debug_connection.nelts; i++) {
 299             if (cidr[i].family != c->sockaddr->sa_family) {
 300                 goto next;
 301             }
 302
 303             switch (cidr[i].family) {
 304
 305 #if (NGX_HAVE_INET6)
 306             case AF_INET6:
 307                 sin6 = (struct sockaddr_in6 *) c->sockaddr;
 308                 for (n = 0; n < 16; n++) {
 309                     if ((sin6->sin6_addr.s6_addr[n]
 310                         & cidr[i].u.in6.mask.s6_addr[n])
 311                         != cidr[i].u.in6.addr.s6_addr[n])
 312                     {
 313                         goto next;
 314                     }
 315                 }
 316                 break;
 317 #endif
 318
 319 #if (NGX_HAVE_UNIX_DOMAIN)
 320             case AF_UNIX:
 321                 break;
 322 #endif
 323
 324             default: /* AF_INET */
 325                 sin = (struct sockaddr_in *) c->sockaddr;
 326                 if ((sin->sin_addr.s_addr & cidr[i].u.in.mask)
 327                     != cidr[i].u.in.addr)
 328                 {
 329                     goto next;
 330                 }
 331                 break;
 332             }
 333
 334             log->log_level = NGX_LOG_DEBUG_CONNECTION|NGX_LOG_DEBUG_ALL;
 335             break;
 336
 337         next:
 338             continue;
 339         }
 340
 341         }
 342 #endif
 343
 344         ngx_log_debug3(NGX_LOG_DEBUG_EVENT, log, 0,
 345                        "*%d accept: %V fd:%d", c->number, &c->addr_text, s);
 346
 347         if (ngx_add_conn && (ngx_event_flags & NGX_USE_EPOLL_EVENT) == 0) {
 348             if (ngx_add_conn(c) == NGX_ERROR) {
 349                 ngx_close_accepted_connection(c);
 350                 return;
 351             }
 352         }
 353
 354         log->data = NULL;
 355         log->handler = NULL;
 356
 357         ls->handler(c);
 358
 359         if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
 360             ev->available--;
 361         }
 362
 363     } while (ev->available);
 364 }
 365
 366
 367 ngx_int_t
 368 ngx_trylock_accept_mutex(ngx_cycle_t *cycle)
 369 {
 370     if (ngx_shmtx_trylock(&ngx_accept_mutex)) {
 371
 372         ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
 373                        "accept mutex locked");
 374
 375         if (ngx_accept_mutex_held
 376             && ngx_accept_events == 0
 377             && !(ngx_event_flags & NGX_USE_RTSIG_EVENT))
 378         {
 379             return NGX_OK;
 380         }
 381
 382         if (ngx_enable_accept_events(cycle) == NGX_ERROR) {
 383             ngx_shmtx_unlock(&ngx_accept_mutex);
 384             return NGX_ERROR;
 385         }
 386
 387         ngx_accept_events = 0;
 388         ngx_accept_mutex_held = 1;
 389
 390         return NGX_OK;
 391     }
 392
 393     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
 394                    "accept mutex lock failed: %ui", ngx_accept_mutex_held);
 395
 396     if (ngx_accept_mutex_held) {
 397         if (ngx_disable_accept_events(cycle) == NGX_ERROR) {
 398             return NGX_ERROR;
 399         }
 400
 401         ngx_accept_mutex_held = 0;
 402     }
 403
 404     return NGX_OK;
 405 }
 406
 407
 408 static ngx_int_t
 409 ngx_enable_accept_events(ngx_cycle_t *cycle)
 410 {
 411     ngx_uint_t         i;
 412     ngx_listening_t   *ls;
 413     ngx_connection_t  *c;
 414
 415     ls = cycle->listening.elts;
 416     for (i = 0; i < cycle->listening.nelts; i++) {
 417
 418         c = ls[i].connection;
 419
 420         if (c->read->active) {
 421             continue;
 422         }
 423
 424         if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
 425
 426             if (ngx_add_conn(c) == NGX_ERROR) {
 427                 return NGX_ERROR;
 428             }
 429
 430         } else {
 431             if (ngx_add_event(c->read, NGX_READ_EVENT, 0) == NGX_ERROR) {
 432                 return NGX_ERROR;
 433             }
 434         }
 435     }
 436
 437     return NGX_OK;
 438 }
 439
 440
 441 static ngx_int_t
 442 ngx_disable_accept_events(ngx_cycle_t *cycle)
 443 {
 444     ngx_uint_t         i;
 445     ngx_listening_t   *ls;
 446     ngx_connection_t  *c;
 447
 448     ls = cycle->listening.elts;
 449     for (i = 0; i < cycle->listening.nelts; i++) {
 450
 451         c = ls[i].connection;
 452
 453         if (!c->read->active) {
 454             continue;
 455         }
 456
 457         if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
 458             if (ngx_del_conn(c, NGX_DISABLE_EVENT) == NGX_ERROR) {
 459                 return NGX_ERROR;
 460             }
 461
 462         } else {
 463             if (ngx_del_event(c->read, NGX_READ_EVENT, NGX_DISABLE_EVENT)
 464                 == NGX_ERROR)
 465             {
 466                 return NGX_ERROR;
 467             }
 468         }
 469     }
 470
 471     return NGX_OK;
 472 }
 473
 474
 475 static void
 476 ngx_close_accepted_connection(ngx_connection_t *c)
 477 {
 478     ngx_socket_t  fd;
 479
 480     ngx_free_connection(c);
 481
 482     fd = c->fd;
 483     c->fd = (ngx_socket_t) -1;
 484
 485     if (ngx_close_socket(fd) == -1) {
 486         ngx_log_error(NGX_LOG_ALERT, c->log, ngx_socket_errno,
 487                       ngx_close_socket_n " failed");
 488     }
 489
 490     if (c->pool) {
 491         ngx_destroy_pool(c->pool);
 492     }
 493
 494 #if (NGX_STAT_STUB)
 495     (void) ngx_atomic_fetch_add(ngx_stat_active, -1);
 496 #endif
 497 }
 498
 499
 500 u_char *
 501 ngx_accept_log_error(ngx_log_t *log, u_char *buf, size_t len)
 502 {
 503     return ngx_snprintf(buf, len, " while accepting new connection on %V",
 504                         log->data);
 505 }