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      1 /*
      2  * Event loop - empty template (basic structure, but no OS specific operations)
      3  * Copyright (c) 2002-2009, Jouni Malinen <j (at) w1.fi>
      4  *
      5  * This software may be distributed under the terms of the BSD license.
      6  * See README for more details.
      7  */
      8 
      9 #include "includes.h"
     10 
     11 #include "common.h"
     12 #include "list.h"
     13 #include "eloop.h"
     14 
     15 
     16 struct eloop_sock {
     17 	int sock;
     18 	void *eloop_data;
     19 	void *user_data;
     20 	eloop_sock_handler handler;
     21 };
     22 
     23 struct eloop_timeout {
     24 	struct dl_list list;
     25 	struct os_time time;
     26 	void *eloop_data;
     27 	void *user_data;
     28 	eloop_timeout_handler handler;
     29 };
     30 
     31 struct eloop_signal {
     32 	int sig;
     33 	void *user_data;
     34 	eloop_signal_handler handler;
     35 	int signaled;
     36 };
     37 
     38 struct eloop_data {
     39 	int max_sock, reader_count;
     40 	struct eloop_sock *readers;
     41 
     42 	struct dl_list timeout;
     43 
     44 	int signal_count;
     45 	struct eloop_signal *signals;
     46 	int signaled;
     47 	int pending_terminate;
     48 
     49 	int terminate;
     50 	int reader_table_changed;
     51 };
     52 
     53 static struct eloop_data eloop;
     54 
     55 
     56 int eloop_init(void)
     57 {
     58 	os_memset(&eloop, 0, sizeof(eloop));
     59 	dl_list_init(&eloop.timeout);
     60 	return 0;
     61 }
     62 
     63 
     64 int eloop_register_read_sock(int sock, eloop_sock_handler handler,
     65 			     void *eloop_data, void *user_data)
     66 {
     67 	struct eloop_sock *tmp;
     68 
     69 	tmp = os_realloc_array(eloop.readers, eloop.reader_count + 1,
     70 			       sizeof(struct eloop_sock));
     71 	if (tmp == NULL)
     72 		return -1;
     73 
     74 	tmp[eloop.reader_count].sock = sock;
     75 	tmp[eloop.reader_count].eloop_data = eloop_data;
     76 	tmp[eloop.reader_count].user_data = user_data;
     77 	tmp[eloop.reader_count].handler = handler;
     78 	eloop.reader_count++;
     79 	eloop.readers = tmp;
     80 	if (sock > eloop.max_sock)
     81 		eloop.max_sock = sock;
     82 	eloop.reader_table_changed = 1;
     83 
     84 	return 0;
     85 }
     86 
     87 
     88 void eloop_unregister_read_sock(int sock)
     89 {
     90 	int i;
     91 
     92 	if (eloop.readers == NULL || eloop.reader_count == 0)
     93 		return;
     94 
     95 	for (i = 0; i < eloop.reader_count; i++) {
     96 		if (eloop.readers[i].sock == sock)
     97 			break;
     98 	}
     99 	if (i == eloop.reader_count)
    100 		return;
    101 	if (i != eloop.reader_count - 1) {
    102 		os_memmove(&eloop.readers[i], &eloop.readers[i + 1],
    103 			   (eloop.reader_count - i - 1) *
    104 			   sizeof(struct eloop_sock));
    105 	}
    106 	eloop.reader_count--;
    107 	eloop.reader_table_changed = 1;
    108 }
    109 
    110 
    111 int eloop_register_timeout(unsigned int secs, unsigned int usecs,
    112 			   eloop_timeout_handler handler,
    113 			   void *eloop_data, void *user_data)
    114 {
    115 	struct eloop_timeout *timeout, *tmp;
    116 	os_time_t now_sec;
    117 
    118 	timeout = os_zalloc(sizeof(*timeout));
    119 	if (timeout == NULL)
    120 		return -1;
    121 	if (os_get_time(&timeout->time) < 0) {
    122 		os_free(timeout);
    123 		return -1;
    124 	}
    125 	now_sec = timeout->time.sec;
    126 	timeout->time.sec += secs;
    127 	if (timeout->time.sec < now_sec) {
    128 		/*
    129 		 * Integer overflow - assume long enough timeout to be assumed
    130 		 * to be infinite, i.e., the timeout would never happen.
    131 		 */
    132 		wpa_printf(MSG_DEBUG, "ELOOP: Too long timeout (secs=%u) to "
    133 			   "ever happen - ignore it", secs);
    134 		os_free(timeout);
    135 		return 0;
    136 	}
    137 	timeout->time.usec += usecs;
    138 	while (timeout->time.usec >= 1000000) {
    139 		timeout->time.sec++;
    140 		timeout->time.usec -= 1000000;
    141 	}
    142 	timeout->eloop_data = eloop_data;
    143 	timeout->user_data = user_data;
    144 	timeout->handler = handler;
    145 
    146 	/* Maintain timeouts in order of increasing time */
    147 	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
    148 		if (os_time_before(&timeout->time, &tmp->time)) {
    149 			dl_list_add(tmp->list.prev, &timeout->list);
    150 			return 0;
    151 		}
    152 	}
    153 	dl_list_add_tail(&eloop.timeout, &timeout->list);
    154 
    155 	return 0;
    156 }
    157 
    158 
    159 static void eloop_remove_timeout(struct eloop_timeout *timeout)
    160 {
    161 	dl_list_del(&timeout->list);
    162 	os_free(timeout);
    163 }
    164 
    165 
    166 int eloop_cancel_timeout(eloop_timeout_handler handler,
    167 			 void *eloop_data, void *user_data)
    168 {
    169 	struct eloop_timeout *timeout, *prev;
    170 	int removed = 0;
    171 
    172 	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
    173 			      struct eloop_timeout, list) {
    174 		if (timeout->handler == handler &&
    175 		    (timeout->eloop_data == eloop_data ||
    176 		     eloop_data == ELOOP_ALL_CTX) &&
    177 		    (timeout->user_data == user_data ||
    178 		     user_data == ELOOP_ALL_CTX)) {
    179 			eloop_remove_timeout(timeout);
    180 			removed++;
    181 		}
    182 	}
    183 
    184 	return removed;
    185 }
    186 
    187 
    188 int eloop_cancel_timeout_one(eloop_timeout_handler handler,
    189 			     void *eloop_data, void *user_data,
    190 			     struct os_time *remaining)
    191 {
    192 	struct eloop_timeout *timeout, *prev;
    193 	int removed = 0;
    194 	struct os_time now;
    195 
    196 	os_get_time(&now);
    197 	remaining->sec = remaining->usec = 0;
    198 
    199 	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
    200 			      struct eloop_timeout, list) {
    201 		if (timeout->handler == handler &&
    202 		    (timeout->eloop_data == eloop_data) &&
    203 		    (timeout->user_data == user_data)) {
    204 			removed = 1;
    205 			if (os_time_before(&now, &timeout->time))
    206 				os_time_sub(&timeout->time, &now, remaining);
    207 			eloop_remove_timeout(timeout);
    208 			break;
    209 		}
    210 	}
    211 	return removed;
    212 }
    213 
    214 
    215 int eloop_is_timeout_registered(eloop_timeout_handler handler,
    216 				void *eloop_data, void *user_data)
    217 {
    218 	struct eloop_timeout *tmp;
    219 
    220 	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
    221 		if (tmp->handler == handler &&
    222 		    tmp->eloop_data == eloop_data &&
    223 		    tmp->user_data == user_data)
    224 			return 1;
    225 	}
    226 
    227 	return 0;
    228 }
    229 
    230 
    231 /* TODO: replace with suitable signal handler */
    232 #if 0
    233 static void eloop_handle_signal(int sig)
    234 {
    235 	int i;
    236 
    237 	eloop.signaled++;
    238 	for (i = 0; i < eloop.signal_count; i++) {
    239 		if (eloop.signals[i].sig == sig) {
    240 			eloop.signals[i].signaled++;
    241 			break;
    242 		}
    243 	}
    244 }
    245 #endif
    246 
    247 
    248 static void eloop_process_pending_signals(void)
    249 {
    250 	int i;
    251 
    252 	if (eloop.signaled == 0)
    253 		return;
    254 	eloop.signaled = 0;
    255 
    256 	if (eloop.pending_terminate) {
    257 		eloop.pending_terminate = 0;
    258 	}
    259 
    260 	for (i = 0; i < eloop.signal_count; i++) {
    261 		if (eloop.signals[i].signaled) {
    262 			eloop.signals[i].signaled = 0;
    263 			eloop.signals[i].handler(eloop.signals[i].sig,
    264 						 eloop.signals[i].user_data);
    265 		}
    266 	}
    267 }
    268 
    269 
    270 int eloop_register_signal(int sig, eloop_signal_handler handler,
    271 			  void *user_data)
    272 {
    273 	struct eloop_signal *tmp;
    274 
    275 	tmp = os_realloc_array(eloop.signals, eloop.signal_count + 1,
    276 			       sizeof(struct eloop_signal));
    277 	if (tmp == NULL)
    278 		return -1;
    279 
    280 	tmp[eloop.signal_count].sig = sig;
    281 	tmp[eloop.signal_count].user_data = user_data;
    282 	tmp[eloop.signal_count].handler = handler;
    283 	tmp[eloop.signal_count].signaled = 0;
    284 	eloop.signal_count++;
    285 	eloop.signals = tmp;
    286 
    287 	/* TODO: register signal handler */
    288 
    289 	return 0;
    290 }
    291 
    292 
    293 int eloop_register_signal_terminate(eloop_signal_handler handler,
    294 				    void *user_data)
    295 {
    296 #if 0
    297 	/* TODO: for example */
    298 	int ret = eloop_register_signal(SIGINT, handler, user_data);
    299 	if (ret == 0)
    300 		ret = eloop_register_signal(SIGTERM, handler, user_data);
    301 	return ret;
    302 #endif
    303 	return 0;
    304 }
    305 
    306 
    307 int eloop_register_signal_reconfig(eloop_signal_handler handler,
    308 				   void *user_data)
    309 {
    310 #if 0
    311 	/* TODO: for example */
    312 	return eloop_register_signal(SIGHUP, handler, user_data);
    313 #endif
    314 	return 0;
    315 }
    316 
    317 
    318 void eloop_run(void)
    319 {
    320 	int i;
    321 	struct os_time tv, now;
    322 
    323 	while (!eloop.terminate &&
    324 		(!dl_list_empty(&eloop.timeout) || eloop.reader_count > 0)) {
    325 		struct eloop_timeout *timeout;
    326 		timeout = dl_list_first(&eloop.timeout, struct eloop_timeout,
    327 					list);
    328 		if (timeout) {
    329 			os_get_time(&now);
    330 			if (os_time_before(&now, &timeout->time))
    331 				os_time_sub(&timeout->time, &now, &tv);
    332 			else
    333 				tv.sec = tv.usec = 0;
    334 		}
    335 
    336 		/*
    337 		 * TODO: wait for any event (read socket ready, timeout (tv),
    338 		 * signal
    339 		 */
    340 		os_sleep(1, 0); /* just a dummy wait for testing */
    341 
    342 		eloop_process_pending_signals();
    343 
    344 		/* check if some registered timeouts have occurred */
    345 		timeout = dl_list_first(&eloop.timeout, struct eloop_timeout,
    346 					list);
    347 		if (timeout) {
    348 			os_get_time(&now);
    349 			if (!os_time_before(&now, &timeout->time)) {
    350 				void *eloop_data = timeout->eloop_data;
    351 				void *user_data = timeout->user_data;
    352 				eloop_timeout_handler handler =
    353 					timeout->handler;
    354 				eloop_remove_timeout(timeout);
    355 				handler(eloop_data, user_data);
    356 			}
    357 
    358 		}
    359 
    360 		eloop.reader_table_changed = 0;
    361 		for (i = 0; i < eloop.reader_count; i++) {
    362 			/*
    363 			 * TODO: call each handler that has pending data to
    364 			 * read
    365 			 */
    366 			if (0 /* TODO: eloop.readers[i].sock ready */) {
    367 				eloop.readers[i].handler(
    368 					eloop.readers[i].sock,
    369 					eloop.readers[i].eloop_data,
    370 					eloop.readers[i].user_data);
    371 				if (eloop.reader_table_changed)
    372 					break;
    373 			}
    374 		}
    375 	}
    376 }
    377 
    378 
    379 void eloop_terminate(void)
    380 {
    381 	eloop.terminate = 1;
    382 }
    383 
    384 
    385 void eloop_destroy(void)
    386 {
    387 	struct eloop_timeout *timeout, *prev;
    388 
    389 	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
    390 			      struct eloop_timeout, list) {
    391 		eloop_remove_timeout(timeout);
    392 	}
    393 	os_free(eloop.readers);
    394 	os_free(eloop.signals);
    395 }
    396 
    397 
    398 int eloop_terminated(void)
    399 {
    400 	return eloop.terminate;
    401 }
    402 
    403 
    404 void eloop_wait_for_read_sock(int sock)
    405 {
    406 	/*
    407 	 * TODO: wait for the file descriptor to have something available for
    408 	 * reading
    409 	 */
    410 }
    411