contrib/hostapd-0.4.9/eloop.c

   1 /*
   2  * Event loop based on select() loop
   3  * Copyright (c) 2002-2005, Jouni Malinen <jkmaline@cc.hut.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 <stdlib.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <sys/time.h>
  19 #include <sys/types.h>
  20 #include <unistd.h>
  21 #include <errno.h>
  22 #include <signal.h>
  23
  24 #ifdef CONFIG_NATIVE_WINDOWS
  25 #include "common.h"
  26 #endif /* CONFIG_NATIVE_WINDOWS */
  27
  28 #include "eloop.h"
  29
  30
  31 struct eloop_sock {
  32         int sock;
  33         void *eloop_data;
  34         void *user_data;
  35         void (*handler)(int sock, void *eloop_ctx, void *sock_ctx);
  36 };
  37
  38 struct eloop_timeout {
  39         struct timeval time;
  40         void *eloop_data;
  41         void *user_data;
  42         void (*handler)(void *eloop_ctx, void *sock_ctx);
  43         struct eloop_timeout *next;
  44 };
  45
  46 struct eloop_signal {
  47         int sig;
  48         void *user_data;
  49         void (*handler)(int sig, void *eloop_ctx, void *signal_ctx);
  50         int signaled;
  51 };
  52
  53 struct eloop_data {
  54         void *user_data;
  55
  56         int max_sock, reader_count;
  57         struct eloop_sock *readers;
  58
  59         struct eloop_timeout *timeout;
  60
  61         int signal_count;
  62         struct eloop_signal *signals;
  63         int signaled;
  64         int pending_terminate;
  65
  66         int terminate;
  67         int reader_table_changed;
  68 };
  69
  70 static struct eloop_data eloop;
  71
  72
  73 void eloop_init(void *user_data)
  74 {
  75         memset(&eloop, 0, sizeof(eloop));
  76         eloop.user_data = user_data;
  77 }
  78
  79
  80 int eloop_register_read_sock(int sock,
  81                              void (*handler)(int sock, void *eloop_ctx,
  82                                              void *sock_ctx),
  83                              void *eloop_data, void *user_data)
  84 {
  85         struct eloop_sock *tmp;
  86
  87         tmp = (struct eloop_sock *)
  88                 realloc(eloop.readers,
  89                         (eloop.reader_count + 1) * sizeof(struct eloop_sock));
  90         if (tmp == NULL)
  91                 return -1;
  92
  93         tmp[eloop.reader_count].sock = sock;
  94         tmp[eloop.reader_count].eloop_data = eloop_data;
  95         tmp[eloop.reader_count].user_data = user_data;
  96         tmp[eloop.reader_count].handler = handler;
  97         eloop.reader_count++;
  98         eloop.readers = tmp;
  99         if (sock > eloop.max_sock)
 100                 eloop.max_sock = sock;
 101         eloop.reader_table_changed = 1;
 102
 103         return 0;
 104 }
 105
 106
 107 void eloop_unregister_read_sock(int sock)
 108 {
 109         int i;
 110
 111         if (eloop.readers == NULL || eloop.reader_count == 0)
 112                 return;
 113
 114         for (i = 0; i < eloop.reader_count; i++) {
 115                 if (eloop.readers[i].sock == sock)
 116                         break;
 117         }
 118         if (i == eloop.reader_count)
 119                 return;
 120         if (i != eloop.reader_count - 1) {
 121                 memmove(&eloop.readers[i], &eloop.readers[i + 1],
 122                         (eloop.reader_count - i - 1) *
 123                         sizeof(struct eloop_sock));
 124         }
 125         eloop.reader_count--;
 126         eloop.reader_table_changed = 1;
 127 }
 128
 129
 130 int eloop_register_timeout(unsigned int secs, unsigned int usecs,
 131                            void (*handler)(void *eloop_ctx, void *timeout_ctx),
 132                            void *eloop_data, void *user_data)
 133 {
 134         struct eloop_timeout *timeout, *tmp, *prev;
 135
 136         timeout = (struct eloop_timeout *) malloc(sizeof(*timeout));
 137         if (timeout == NULL)
 138                 return -1;
 139         gettimeofday(&timeout->time, NULL);
 140         timeout->time.tv_sec += secs;
 141         timeout->time.tv_usec += usecs;
 142         while (timeout->time.tv_usec >= 1000000) {
 143                 timeout->time.tv_sec++;
 144                 timeout->time.tv_usec -= 1000000;
 145         }
 146         timeout->eloop_data = eloop_data;
 147         timeout->user_data = user_data;
 148         timeout->handler = handler;
 149         timeout->next = NULL;
 150
 151         if (eloop.timeout == NULL) {
 152                 eloop.timeout = timeout;
 153                 return 0;
 154         }
 155
 156         prev = NULL;
 157         tmp = eloop.timeout;
 158         while (tmp != NULL) {
 159                 if (timercmp(&timeout->time, &tmp->time, <))
 160                         break;
 161                 prev = tmp;
 162                 tmp = tmp->next;
 163         }
 164
 165         if (prev == NULL) {
 166                 timeout->next = eloop.timeout;
 167                 eloop.timeout = timeout;
 168         } else {
 169                 timeout->next = prev->next;
 170                 prev->next = timeout;
 171         }
 172
 173         return 0;
 174 }
 175
 176
 177 int eloop_cancel_timeout(void (*handler)(void *eloop_ctx, void *sock_ctx),
 178                          void *eloop_data, void *user_data)
 179 {
 180         struct eloop_timeout *timeout, *prev, *next;
 181         int removed = 0;
 182
 183         prev = NULL;
 184         timeout = eloop.timeout;
 185         while (timeout != NULL) {
 186                 next = timeout->next;
 187
 188                 if (timeout->handler == handler &&
 189                     (timeout->eloop_data == eloop_data ||
 190                      eloop_data == ELOOP_ALL_CTX) &&
 191                     (timeout->user_data == user_data ||
 192                      user_data == ELOOP_ALL_CTX)) {
 193                         if (prev == NULL)
 194                                 eloop.timeout = next;
 195                         else
 196                                 prev->next = next;
 197                         free(timeout);
 198                         removed++;
 199                 } else
 200                         prev = timeout;
 201
 202                 timeout = next;
 203         }
 204
 205         return removed;
 206 }
 207
 208
 209 #ifndef CONFIG_NATIVE_WINDOWS
 210 static void eloop_handle_alarm(int sig)
 211 {
 212         fprintf(stderr, "eloop: could not process SIGINT or SIGTERM in two "
 213                 "seconds. Looks like there\n"
 214                 "is a bug that ends up in a busy loop that "
 215                 "prevents clean shutdown.\n"
 216                 "Killing program forcefully.\n");
 217         exit(1);
 218 }
 219 #endif /* CONFIG_NATIVE_WINDOWS */
 220
 221
 222 static void eloop_handle_signal(int sig)
 223 {
 224         int i;
 225
 226 #ifndef CONFIG_NATIVE_WINDOWS
 227         if ((sig == SIGINT || sig == SIGTERM) && !eloop.pending_terminate) {
 228                 /* Use SIGALRM to break out from potential busy loops that
 229                  * would not allow the program to be killed. */
 230                 eloop.pending_terminate = 1;
 231                 signal(SIGALRM, eloop_handle_alarm);
 232                 alarm(2);
 233         }
 234 #endif /* CONFIG_NATIVE_WINDOWS */
 235
 236         eloop.signaled++;
 237         for (i = 0; i < eloop.signal_count; i++) {
 238                 if (eloop.signals[i].sig == sig) {
 239                         eloop.signals[i].signaled++;
 240                         break;
 241                 }
 242         }
 243 }
 244
 245
 246 static void eloop_process_pending_signals(void)
 247 {
 248         int i;
 249
 250         if (eloop.signaled == 0)
 251                 return;
 252         eloop.signaled = 0;
 253
 254         if (eloop.pending_terminate) {
 255 #ifndef CONFIG_NATIVE_WINDOWS
 256                 alarm(0);
 257 #endif /* CONFIG_NATIVE_WINDOWS */
 258                 eloop.pending_terminate = 0;
 259         }
 260
 261         for (i = 0; i < eloop.signal_count; i++) {
 262                 if (eloop.signals[i].signaled) {
 263                         eloop.signals[i].signaled = 0;
 264                         eloop.signals[i].handler(eloop.signals[i].sig,
 265                                                  eloop.user_data,
 266                                                  eloop.signals[i].user_data);
 267                 }
 268         }
 269 }
 270
 271
 272 int eloop_register_signal(int sig,
 273                           void (*handler)(int sig, void *eloop_ctx,
 274                                           void *signal_ctx),
 275                           void *user_data)
 276 {
 277         struct eloop_signal *tmp;
 278
 279         tmp = (struct eloop_signal *)
 280                 realloc(eloop.signals,
 281                         (eloop.signal_count + 1) *
 282                         sizeof(struct eloop_signal));
 283         if (tmp == NULL)
 284                 return -1;
 285
 286         tmp[eloop.signal_count].sig = sig;
 287         tmp[eloop.signal_count].user_data = user_data;
 288         tmp[eloop.signal_count].handler = handler;
 289         tmp[eloop.signal_count].signaled = 0;
 290         eloop.signal_count++;
 291         eloop.signals = tmp;
 292         signal(sig, eloop_handle_signal);
 293
 294         return 0;
 295 }
 296
 297
 298 void eloop_run(void)
 299 {
 300         fd_set *rfds;
 301         int i, res;
 302         struct timeval tv, now;
 303
 304         rfds = malloc(sizeof(*rfds));
 305         if (rfds == NULL) {
 306                 printf("eloop_run - malloc failed\n");
 307                 return;
 308         }
 309
 310         while (!eloop.terminate &&
 311                 (eloop.timeout || eloop.reader_count > 0)) {
 312                 if (eloop.timeout) {
 313                         gettimeofday(&now, NULL);
 314                         if (timercmp(&now, &eloop.timeout->time, <))
 315                                 timersub(&eloop.timeout->time, &now, &tv);
 316                         else
 317                                 tv.tv_sec = tv.tv_usec = 0;
 318 #if 0
 319                         printf("next timeout in %lu.%06lu sec\n",
 320                                tv.tv_sec, tv.tv_usec);
 321 #endif
 322                 }
 323
 324                 FD_ZERO(rfds);
 325                 for (i = 0; i < eloop.reader_count; i++)
 326                         FD_SET(eloop.readers[i].sock, rfds);
 327                 res = select(eloop.max_sock + 1, rfds, NULL, NULL,
 328                              eloop.timeout ? &tv : NULL);
 329                 if (res < 0 && errno != EINTR) {
 330                         perror("select");
 331                         free(rfds);
 332                         return;
 333                 }
 334                 eloop_process_pending_signals();
 335
 336                 /* check if some registered timeouts have occurred */
 337                 if (eloop.timeout) {
 338                         struct eloop_timeout *tmp;
 339
 340                         gettimeofday(&now, NULL);
 341                         if (!timercmp(&now, &eloop.timeout->time, <)) {
 342                                 tmp = eloop.timeout;
 343                                 eloop.timeout = eloop.timeout->next;
 344                                 tmp->handler(tmp->eloop_data,
 345                                              tmp->user_data);
 346                                 free(tmp);
 347                         }
 348
 349                 }
 350
 351                 if (res <= 0)
 352                         continue;
 353
 354                 eloop.reader_table_changed = 0;
 355                 for (i = 0; i < eloop.reader_count; i++) {
 356                         if (FD_ISSET(eloop.readers[i].sock, rfds)) {
 357                                 eloop.readers[i].handler(
 358                                         eloop.readers[i].sock,
 359                                         eloop.readers[i].eloop_data,
 360                                         eloop.readers[i].user_data);
 361                                 if (eloop.reader_table_changed)
 362                                         break;
 363                         }
 364                 }
 365         }
 366
 367         free(rfds);
 368 }
 369
 370
 371 void eloop_terminate(void)
 372 {
 373         eloop.terminate = 1;
 374 }
 375
 376
 377 void eloop_destroy(void)
 378 {
 379         struct eloop_timeout *timeout, *prev;
 380
 381         timeout = eloop.timeout;
 382         while (timeout != NULL) {
 383                 prev = timeout;
 384                 timeout = timeout->next;
 385                 free(prev);
 386         }
 387         free(eloop.readers);
 388         free(eloop.signals);
 389 }
 390
 391
 392 int eloop_terminated(void)
 393 {
 394         return eloop.terminate;
 395 }