contrib/hostapd-0.5.8/eloop.c

   1 /*
   2  * Event loop based on select() loop
   3  * Copyright (c) 2002-2005, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "eloop.h"
  19
  20
  21 struct eloop_sock {
  22         int sock;
  23         void *eloop_data;
  24         void *user_data;
  25         eloop_sock_handler handler;
  26 };
  27
  28 struct eloop_timeout {
  29         struct os_time time;
  30         void *eloop_data;
  31         void *user_data;
  32         eloop_timeout_handler handler;
  33         struct eloop_timeout *next;
  34 };
  35
  36 struct eloop_signal {
  37         int sig;
  38         void *user_data;
  39         eloop_signal_handler handler;
  40         int signaled;
  41 };
  42
  43 struct eloop_sock_table {
  44         int count;
  45         struct eloop_sock *table;
  46         int changed;
  47 };
  48
  49 struct eloop_data {
  50         void *user_data;
  51
  52         int max_sock;
  53
  54         struct eloop_sock_table readers;
  55         struct eloop_sock_table writers;
  56         struct eloop_sock_table exceptions;
  57
  58         struct eloop_timeout *timeout;
  59
  60         int signal_count;
  61         struct eloop_signal *signals;
  62         int signaled;
  63         int pending_terminate;
  64
  65         int terminate;
  66         int reader_table_changed;
  67 };
  68
  69 static struct eloop_data eloop;
  70
  71
  72 int eloop_init(void *user_data)
  73 {
  74         os_memset(&eloop, 0, sizeof(eloop));
  75         eloop.user_data = user_data;
  76         return 0;
  77 }
  78
  79
  80 static int eloop_sock_table_add_sock(struct eloop_sock_table *table,
  81                                      int sock, eloop_sock_handler handler,
  82                                      void *eloop_data, void *user_data)
  83 {
  84         struct eloop_sock *tmp;
  85
  86         if (table == NULL)
  87                 return -1;
  88
  89         tmp = (struct eloop_sock *)
  90                 os_realloc(table->table,
  91                            (table->count + 1) * sizeof(struct eloop_sock));
  92         if (tmp == NULL)
  93                 return -1;
  94
  95         tmp[table->count].sock = sock;
  96         tmp[table->count].eloop_data = eloop_data;
  97         tmp[table->count].user_data = user_data;
  98         tmp[table->count].handler = handler;
  99         table->count++;
 100         table->table = tmp;
 101         if (sock > eloop.max_sock)
 102                 eloop.max_sock = sock;
 103         table->changed = 1;
 104
 105         return 0;
 106 }
 107
 108
 109 static void eloop_sock_table_remove_sock(struct eloop_sock_table *table,
 110                                          int sock)
 111 {
 112         int i;
 113
 114         if (table == NULL || table->table == NULL || table->count == 0)
 115                 return;
 116
 117         for (i = 0; i < table->count; i++) {
 118                 if (table->table[i].sock == sock)
 119                         break;
 120         }
 121         if (i == table->count)
 122                 return;
 123         if (i != table->count - 1) {
 124                 os_memmove(&table->table[i], &table->table[i + 1],
 125                            (table->count - i - 1) *
 126                            sizeof(struct eloop_sock));
 127         }
 128         table->count--;
 129         table->changed = 1;
 130 }
 131
 132
 133 static void eloop_sock_table_set_fds(struct eloop_sock_table *table,
 134                                      fd_set *fds)
 135 {
 136         int i;
 137
 138         FD_ZERO(fds);
 139
 140         if (table->table == NULL)
 141                 return;
 142
 143         for (i = 0; i < table->count; i++)
 144                 FD_SET(table->table[i].sock, fds);
 145 }
 146
 147
 148 static void eloop_sock_table_dispatch(struct eloop_sock_table *table,
 149                                       fd_set *fds)
 150 {
 151         int i;
 152
 153         if (table == NULL || table->table == NULL)
 154                 return;
 155
 156         table->changed = 0;
 157         for (i = 0; i < table->count; i++) {
 158                 if (FD_ISSET(table->table[i].sock, fds)) {
 159                         table->table[i].handler(table->table[i].sock,
 160                                                 table->table[i].eloop_data,
 161                                                 table->table[i].user_data);
 162                         if (table->changed)
 163                                 break;
 164                 }
 165         }
 166 }
 167
 168
 169 static void eloop_sock_table_destroy(struct eloop_sock_table *table)
 170 {
 171         if (table)
 172                 os_free(table->table);
 173 }
 174
 175
 176 int eloop_register_read_sock(int sock, eloop_sock_handler handler,
 177                              void *eloop_data, void *user_data)
 178 {
 179         return eloop_register_sock(sock, EVENT_TYPE_READ, handler,
 180                                    eloop_data, user_data);
 181 }
 182
 183
 184 void eloop_unregister_read_sock(int sock)
 185 {
 186         eloop_unregister_sock(sock, EVENT_TYPE_READ);
 187 }
 188
 189
 190 static struct eloop_sock_table *eloop_get_sock_table(eloop_event_type type)
 191 {
 192         switch (type) {
 193         case EVENT_TYPE_READ:
 194                 return &eloop.readers;
 195         case EVENT_TYPE_WRITE:
 196                 return &eloop.writers;
 197         case EVENT_TYPE_EXCEPTION:
 198                 return &eloop.exceptions;
 199         }
 200
 201         return NULL;
 202 }
 203
 204
 205 int eloop_register_sock(int sock, eloop_event_type type,
 206                         eloop_sock_handler handler,
 207                         void *eloop_data, void *user_data)
 208 {
 209         struct eloop_sock_table *table;
 210
 211         table = eloop_get_sock_table(type);
 212         return eloop_sock_table_add_sock(table, sock, handler,
 213                                          eloop_data, user_data);
 214 }
 215
 216
 217 void eloop_unregister_sock(int sock, eloop_event_type type)
 218 {
 219         struct eloop_sock_table *table;
 220
 221         table = eloop_get_sock_table(type);
 222         eloop_sock_table_remove_sock(table, sock);
 223 }
 224
 225
 226 int eloop_register_timeout(unsigned int secs, unsigned int usecs,
 227                            eloop_timeout_handler handler,
 228                            void *eloop_data, void *user_data)
 229 {
 230         struct eloop_timeout *timeout, *tmp, *prev;
 231
 232         timeout = os_malloc(sizeof(*timeout));
 233         if (timeout == NULL)
 234                 return -1;
 235         os_get_time(&timeout->time);
 236         timeout->time.sec += secs;
 237         timeout->time.usec += usecs;
 238         while (timeout->time.usec >= 1000000) {
 239                 timeout->time.sec++;
 240                 timeout->time.usec -= 1000000;
 241         }
 242         timeout->eloop_data = eloop_data;
 243         timeout->user_data = user_data;
 244         timeout->handler = handler;
 245         timeout->next = NULL;
 246
 247         if (eloop.timeout == NULL) {
 248                 eloop.timeout = timeout;
 249                 return 0;
 250         }
 251
 252         prev = NULL;
 253         tmp = eloop.timeout;
 254         while (tmp != NULL) {
 255                 if (os_time_before(&timeout->time, &tmp->time))
 256                         break;
 257                 prev = tmp;
 258                 tmp = tmp->next;
 259         }
 260
 261         if (prev == NULL) {
 262                 timeout->next = eloop.timeout;
 263                 eloop.timeout = timeout;
 264         } else {
 265                 timeout->next = prev->next;
 266                 prev->next = timeout;
 267         }
 268
 269         return 0;
 270 }
 271
 272
 273 int eloop_cancel_timeout(eloop_timeout_handler handler,
 274                          void *eloop_data, void *user_data)
 275 {
 276         struct eloop_timeout *timeout, *prev, *next;
 277         int removed = 0;
 278
 279         prev = NULL;
 280         timeout = eloop.timeout;
 281         while (timeout != NULL) {
 282                 next = timeout->next;
 283
 284                 if (timeout->handler == handler &&
 285                     (timeout->eloop_data == eloop_data ||
 286                      eloop_data == ELOOP_ALL_CTX) &&
 287                     (timeout->user_data == user_data ||
 288                      user_data == ELOOP_ALL_CTX)) {
 289                         if (prev == NULL)
 290                                 eloop.timeout = next;
 291                         else
 292                                 prev->next = next;
 293                         os_free(timeout);
 294                         removed++;
 295                 } else
 296                         prev = timeout;
 297
 298                 timeout = next;
 299         }
 300
 301         return removed;
 302 }
 303
 304
 305 #ifndef CONFIG_NATIVE_WINDOWS
 306 static void eloop_handle_alarm(int sig)
 307 {
 308         fprintf(stderr, "eloop: could not process SIGINT or SIGTERM in two "
 309                 "seconds. Looks like there\n"
 310                 "is a bug that ends up in a busy loop that "
 311                 "prevents clean shutdown.\n"
 312                 "Killing program forcefully.\n");
 313         exit(1);
 314 }
 315 #endif /* CONFIG_NATIVE_WINDOWS */
 316
 317
 318 static void eloop_handle_signal(int sig)
 319 {
 320         int i;
 321
 322 #ifndef CONFIG_NATIVE_WINDOWS
 323         if ((sig == SIGINT || sig == SIGTERM) && !eloop.pending_terminate) {
 324                 /* Use SIGALRM to break out from potential busy loops that
 325                  * would not allow the program to be killed. */
 326                 eloop.pending_terminate = 1;
 327                 signal(SIGALRM, eloop_handle_alarm);
 328                 alarm(2);
 329         }
 330 #endif /* CONFIG_NATIVE_WINDOWS */
 331
 332         eloop.signaled++;
 333         for (i = 0; i < eloop.signal_count; i++) {
 334                 if (eloop.signals[i].sig == sig) {
 335                         eloop.signals[i].signaled++;
 336                         break;
 337                 }
 338         }
 339 }
 340
 341
 342 static void eloop_process_pending_signals(void)
 343 {
 344         int i;
 345
 346         if (eloop.signaled == 0)
 347                 return;
 348         eloop.signaled = 0;
 349
 350         if (eloop.pending_terminate) {
 351 #ifndef CONFIG_NATIVE_WINDOWS
 352                 alarm(0);
 353 #endif /* CONFIG_NATIVE_WINDOWS */
 354                 eloop.pending_terminate = 0;
 355         }
 356
 357         for (i = 0; i < eloop.signal_count; i++) {
 358                 if (eloop.signals[i].signaled) {
 359                         eloop.signals[i].signaled = 0;
 360                         eloop.signals[i].handler(eloop.signals[i].sig,
 361                                                  eloop.user_data,
 362                                                  eloop.signals[i].user_data);
 363                 }
 364         }
 365 }
 366
 367
 368 int eloop_register_signal(int sig, eloop_signal_handler handler,
 369                           void *user_data)
 370 {
 371         struct eloop_signal *tmp;
 372
 373         tmp = (struct eloop_signal *)
 374                 os_realloc(eloop.signals,
 375                            (eloop.signal_count + 1) *
 376                            sizeof(struct eloop_signal));
 377         if (tmp == NULL)
 378                 return -1;
 379
 380         tmp[eloop.signal_count].sig = sig;
 381         tmp[eloop.signal_count].user_data = user_data;
 382         tmp[eloop.signal_count].handler = handler;
 383         tmp[eloop.signal_count].signaled = 0;
 384         eloop.signal_count++;
 385         eloop.signals = tmp;
 386         signal(sig, eloop_handle_signal);
 387
 388         return 0;
 389 }
 390
 391
 392 int eloop_register_signal_terminate(eloop_signal_handler handler,
 393                                     void *user_data)
 394 {
 395         int ret = eloop_register_signal(SIGINT, handler, user_data);
 396         if (ret == 0)
 397                 ret = eloop_register_signal(SIGTERM, handler, user_data);
 398         return ret;
 399 }
 400
 401
 402 int eloop_register_signal_reconfig(eloop_signal_handler handler,
 403                                    void *user_data)
 404 {
 405 #ifdef CONFIG_NATIVE_WINDOWS
 406         return 0;
 407 #else /* CONFIG_NATIVE_WINDOWS */
 408         return eloop_register_signal(SIGHUP, handler, user_data);
 409 #endif /* CONFIG_NATIVE_WINDOWS */
 410 }
 411
 412
 413 void eloop_run(void)
 414 {
 415         fd_set *rfds, *wfds, *efds;
 416         int res;
 417         struct timeval _tv;
 418         struct os_time tv, now;
 419
 420         rfds = os_malloc(sizeof(*rfds));
 421         wfds = os_malloc(sizeof(*wfds));
 422         efds = os_malloc(sizeof(*efds));
 423         if (rfds == NULL || wfds == NULL || efds == NULL) {
 424                 printf("eloop_run - malloc failed\n");
 425                 goto out;
 426         }
 427
 428         while (!eloop.terminate &&
 429                (eloop.timeout || eloop.readers.count > 0 ||
 430                 eloop.writers.count > 0 || eloop.exceptions.count > 0)) {
 431                 if (eloop.timeout) {
 432                         os_get_time(&now);
 433                         if (os_time_before(&now, &eloop.timeout->time))
 434                                 os_time_sub(&eloop.timeout->time, &now, &tv);
 435                         else
 436                                 tv.sec = tv.usec = 0;
 437 #if 0
 438                         printf("next timeout in %lu.%06lu sec\n",
 439                                tv.sec, tv.usec);
 440 #endif
 441                         _tv.tv_sec = tv.sec;
 442                         _tv.tv_usec = tv.usec;
 443                 }
 444
 445                 eloop_sock_table_set_fds(&eloop.readers, rfds);
 446                 eloop_sock_table_set_fds(&eloop.writers, wfds);
 447                 eloop_sock_table_set_fds(&eloop.exceptions, efds);
 448                 res = select(eloop.max_sock + 1, rfds, wfds, efds,
 449                              eloop.timeout ? &_tv : NULL);
 450                 if (res < 0 && errno != EINTR && errno != 0) {
 451                         perror("select");
 452                         goto out;
 453                 }
 454                 eloop_process_pending_signals();
 455
 456                 /* check if some registered timeouts have occurred */
 457                 if (eloop.timeout) {
 458                         struct eloop_timeout *tmp;
 459
 460                         os_get_time(&now);
 461                         if (!os_time_before(&now, &eloop.timeout->time)) {
 462                                 tmp = eloop.timeout;
 463                                 eloop.timeout = eloop.timeout->next;
 464                                 tmp->handler(tmp->eloop_data,
 465                                              tmp->user_data);
 466                                 os_free(tmp);
 467                         }
 468
 469                 }
 470
 471                 if (res <= 0)
 472                         continue;
 473
 474                 eloop_sock_table_dispatch(&eloop.readers, rfds);
 475                 eloop_sock_table_dispatch(&eloop.writers, wfds);
 476                 eloop_sock_table_dispatch(&eloop.exceptions, efds);
 477         }
 478
 479 out:
 480         os_free(rfds);
 481         os_free(wfds);
 482         os_free(efds);
 483 }
 484
 485
 486 void eloop_terminate(void)
 487 {
 488         eloop.terminate = 1;
 489 }
 490
 491
 492 void eloop_destroy(void)
 493 {
 494         struct eloop_timeout *timeout, *prev;
 495
 496         timeout = eloop.timeout;
 497         while (timeout != NULL) {
 498                 prev = timeout;
 499                 timeout = timeout->next;
 500                 os_free(prev);
 501         }
 502         eloop_sock_table_destroy(&eloop.readers);
 503         eloop_sock_table_destroy(&eloop.writers);
 504         eloop_sock_table_destroy(&eloop.exceptions);
 505         os_free(eloop.signals);
 506 }
 507
 508
 509 int eloop_terminated(void)
 510 {
 511         return eloop.terminate;
 512 }
 513
 514
 515 void eloop_wait_for_read_sock(int sock)
 516 {
 517         fd_set rfds;
 518
 519         if (sock < 0)
 520                 return;
 521
 522         FD_ZERO(&rfds);
 523         FD_SET(sock, &rfds);
 524         select(sock + 1, &rfds, NULL, NULL, NULL);
 525 }
 526
 527
 528 void * eloop_get_user_data(void)
 529 {
 530         return eloop.user_data;
 531 }