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      1 /*
      2  * Event loop - empty template (basic structure, but no OS specific operations)
      3  * Copyright (c) 2002-2005, Jouni Malinen <j (at) 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 	void (*handler)(int sock, void *eloop_ctx, void *sock_ctx);
     26 };
     27 
     28 struct eloop_timeout {
     29 	struct os_time time;
     30 	void *eloop_data;
     31 	void *user_data;
     32 	void (*handler)(void *eloop_ctx, void *sock_ctx);
     33 	struct eloop_timeout *next;
     34 };
     35 
     36 struct eloop_signal {
     37 	int sig;
     38 	void *user_data;
     39 	void (*handler)(int sig, void *eloop_ctx, void *signal_ctx);
     40 	int signaled;
     41 };
     42 
     43 struct eloop_data {
     44 	void *user_data;
     45 
     46 	int max_sock, reader_count;
     47 	struct eloop_sock *readers;
     48 
     49 	struct eloop_timeout *timeout;
     50 
     51 	int signal_count;
     52 	struct eloop_signal *signals;
     53 	int signaled;
     54 	int pending_terminate;
     55 
     56 	int terminate;
     57 	int reader_table_changed;
     58 };
     59 
     60 static struct eloop_data eloop;
     61 
     62 
     63 int eloop_init(void *user_data)
     64 {
     65 	memset(&eloop, 0, sizeof(eloop));
     66 	eloop.user_data = user_data;
     67 	return 0;
     68 }
     69 
     70 
     71 int eloop_register_read_sock(int sock,
     72 			     void (*handler)(int sock, void *eloop_ctx,
     73 					     void *sock_ctx),
     74 			     void *eloop_data, void *user_data)
     75 {
     76 	struct eloop_sock *tmp;
     77 
     78 	tmp = (struct eloop_sock *)
     79 		realloc(eloop.readers,
     80 			(eloop.reader_count + 1) * sizeof(struct eloop_sock));
     81 	if (tmp == NULL)
     82 		return -1;
     83 
     84 	tmp[eloop.reader_count].sock = sock;
     85 	tmp[eloop.reader_count].eloop_data = eloop_data;
     86 	tmp[eloop.reader_count].user_data = user_data;
     87 	tmp[eloop.reader_count].handler = handler;
     88 	eloop.reader_count++;
     89 	eloop.readers = tmp;
     90 	if (sock > eloop.max_sock)
     91 		eloop.max_sock = sock;
     92 	eloop.reader_table_changed = 1;
     93 
     94 	return 0;
     95 }
     96 
     97 
     98 void eloop_unregister_read_sock(int sock)
     99 {
    100 	int i;
    101 
    102 	if (eloop.readers == NULL || eloop.reader_count == 0)
    103 		return;
    104 
    105 	for (i = 0; i < eloop.reader_count; i++) {
    106 		if (eloop.readers[i].sock == sock)
    107 			break;
    108 	}
    109 	if (i == eloop.reader_count)
    110 		return;
    111 	if (i != eloop.reader_count - 1) {
    112 		memmove(&eloop.readers[i], &eloop.readers[i + 1],
    113 			(eloop.reader_count - i - 1) *
    114 			sizeof(struct eloop_sock));
    115 	}
    116 	eloop.reader_count--;
    117 	eloop.reader_table_changed = 1;
    118 }
    119 
    120 
    121 int eloop_register_timeout(unsigned int secs, unsigned int usecs,
    122 			   void (*handler)(void *eloop_ctx, void *timeout_ctx),
    123 			   void *eloop_data, void *user_data)
    124 {
    125 	struct eloop_timeout *timeout, *tmp, *prev;
    126 
    127 	timeout = (struct eloop_timeout *) malloc(sizeof(*timeout));
    128 	if (timeout == NULL)
    129 		return -1;
    130 	os_get_time(&timeout->time);
    131 	timeout->time.sec += secs;
    132 	timeout->time.usec += usecs;
    133 	while (timeout->time.usec >= 1000000) {
    134 		timeout->time.sec++;
    135 		timeout->time.usec -= 1000000;
    136 	}
    137 	timeout->eloop_data = eloop_data;
    138 	timeout->user_data = user_data;
    139 	timeout->handler = handler;
    140 	timeout->next = NULL;
    141 
    142 	if (eloop.timeout == NULL) {
    143 		eloop.timeout = timeout;
    144 		return 0;
    145 	}
    146 
    147 	prev = NULL;
    148 	tmp = eloop.timeout;
    149 	while (tmp != NULL) {
    150 		if (os_time_before(&timeout->time, &tmp->time))
    151 			break;
    152 		prev = tmp;
    153 		tmp = tmp->next;
    154 	}
    155 
    156 	if (prev == NULL) {
    157 		timeout->next = eloop.timeout;
    158 		eloop.timeout = timeout;
    159 	} else {
    160 		timeout->next = prev->next;
    161 		prev->next = timeout;
    162 	}
    163 
    164 	return 0;
    165 }
    166 
    167 
    168 int eloop_cancel_timeout(void (*handler)(void *eloop_ctx, void *sock_ctx),
    169 			 void *eloop_data, void *user_data)
    170 {
    171 	struct eloop_timeout *timeout, *prev, *next;
    172 	int removed = 0;
    173 
    174 	prev = NULL;
    175 	timeout = eloop.timeout;
    176 	while (timeout != NULL) {
    177 		next = timeout->next;
    178 
    179 		if (timeout->handler == handler &&
    180 		    (timeout->eloop_data == eloop_data ||
    181 		     eloop_data == ELOOP_ALL_CTX) &&
    182 		    (timeout->user_data == user_data ||
    183 		     user_data == ELOOP_ALL_CTX)) {
    184 			if (prev == NULL)
    185 				eloop.timeout = next;
    186 			else
    187 				prev->next = next;
    188 			free(timeout);
    189 			removed++;
    190 		} else
    191 			prev = timeout;
    192 
    193 		timeout = next;
    194 	}
    195 
    196 	return removed;
    197 }
    198 
    199 
    200 int eloop_is_timeout_registered(void (*handler)(void *eloop_ctx,
    201 						void *timeout_ctx),
    202 				void *eloop_data, void *user_data)
    203 {
    204 	struct eloop_timeout *tmp;
    205 
    206 	tmp = eloop.timeout;
    207 	while (tmp != NULL) {
    208 		if (tmp->handler == handler &&
    209 		    tmp->eloop_data == eloop_data &&
    210 		    tmp->user_data == user_data)
    211 			return 1;
    212 
    213 		tmp = tmp->next;
    214 	}
    215 
    216 	return 0;
    217 }
    218 
    219 
    220 /* TODO: replace with suitable signal handler */
    221 #if 0
    222 static void eloop_handle_signal(int sig)
    223 {
    224 	int i;
    225 
    226 	eloop.signaled++;
    227 	for (i = 0; i < eloop.signal_count; i++) {
    228 		if (eloop.signals[i].sig == sig) {
    229 			eloop.signals[i].signaled++;
    230 			break;
    231 		}
    232 	}
    233 }
    234 #endif
    235 
    236 
    237 static void eloop_process_pending_signals(void)
    238 {
    239 	int i;
    240 
    241 	if (eloop.signaled == 0)
    242 		return;
    243 	eloop.signaled = 0;
    244 
    245 	if (eloop.pending_terminate) {
    246 		eloop.pending_terminate = 0;
    247 	}
    248 
    249 	for (i = 0; i < eloop.signal_count; i++) {
    250 		if (eloop.signals[i].signaled) {
    251 			eloop.signals[i].signaled = 0;
    252 			eloop.signals[i].handler(eloop.signals[i].sig,
    253 						 eloop.user_data,
    254 						 eloop.signals[i].user_data);
    255 		}
    256 	}
    257 }
    258 
    259 
    260 int eloop_register_signal(int sig,
    261 			  void (*handler)(int sig, void *eloop_ctx,
    262 					  void *signal_ctx),
    263 			  void *user_data)
    264 {
    265 	struct eloop_signal *tmp;
    266 
    267 	tmp = (struct eloop_signal *)
    268 		realloc(eloop.signals,
    269 			(eloop.signal_count + 1) *
    270 			sizeof(struct eloop_signal));
    271 	if (tmp == NULL)
    272 		return -1;
    273 
    274 	tmp[eloop.signal_count].sig = sig;
    275 	tmp[eloop.signal_count].user_data = user_data;
    276 	tmp[eloop.signal_count].handler = handler;
    277 	tmp[eloop.signal_count].signaled = 0;
    278 	eloop.signal_count++;
    279 	eloop.signals = tmp;
    280 
    281 	/* TODO: register signal handler */
    282 
    283 	return 0;
    284 }
    285 
    286 
    287 int eloop_register_signal_terminate(void (*handler)(int sig, void *eloop_ctx,
    288 						    void *signal_ctx),
    289 				    void *user_data)
    290 {
    291 #if 0
    292 	/* TODO: for example */
    293 	int ret = eloop_register_signal(SIGINT, handler, user_data);
    294 	if (ret == 0)
    295 		ret = eloop_register_signal(SIGTERM, handler, user_data);
    296 	return ret;
    297 #endif
    298 	return 0;
    299 }
    300 
    301 
    302 int eloop_register_signal_reconfig(void (*handler)(int sig, void *eloop_ctx,
    303 						   void *signal_ctx),
    304 				   void *user_data)
    305 {
    306 #if 0
    307 	/* TODO: for example */
    308 	return eloop_register_signal(SIGHUP, handler, user_data);
    309 #endif
    310 	return 0;
    311 }
    312 
    313 
    314 void eloop_run(void)
    315 {
    316 	int i;
    317 	struct os_time tv, now;
    318 
    319 	while (!eloop.terminate &&
    320 		(eloop.timeout || eloop.reader_count > 0)) {
    321 		if (eloop.timeout) {
    322 			os_get_time(&now);
    323 			if (os_time_before(&now, &eloop.timeout->time))
    324 				os_time_sub(&eloop.timeout->time, &now, &tv);
    325 			else
    326 				tv.sec = tv.usec = 0;
    327 		}
    328 
    329 		/*
    330 		 * TODO: wait for any event (read socket ready, timeout (tv),
    331 		 * signal
    332 		 */
    333 		os_sleep(1, 0); /* just a dummy wait for testing */
    334 
    335 		eloop_process_pending_signals();
    336 
    337 		/* check if some registered timeouts have occurred */
    338 		if (eloop.timeout) {
    339 			struct eloop_timeout *tmp;
    340 
    341 			os_get_time(&now);
    342 			if (!os_time_before(&now, &eloop.timeout->time)) {
    343 				tmp = eloop.timeout;
    344 				eloop.timeout = eloop.timeout->next;
    345 				tmp->handler(tmp->eloop_data,
    346 					     tmp->user_data);
    347 				free(tmp);
    348 			}
    349 
    350 		}
    351 
    352 		eloop.reader_table_changed = 0;
    353 		for (i = 0; i < eloop.reader_count; i++) {
    354 			/*
    355 			 * TODO: call each handler that has pending data to
    356 			 * read
    357 			 */
    358 			if (0 /* TODO: eloop.readers[i].sock ready */) {
    359 				eloop.readers[i].handler(
    360 					eloop.readers[i].sock,
    361 					eloop.readers[i].eloop_data,
    362 					eloop.readers[i].user_data);
    363 				if (eloop.reader_table_changed)
    364 					break;
    365 			}
    366 		}
    367 	}
    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 }
    396 
    397 
    398 void eloop_wait_for_read_sock(int sock)
    399 {
    400 	/*
    401 	 * TODO: wait for the file descriptor to have something available for
    402 	 * reading
    403 	 */
    404 }
    405 
    406 
    407 void * eloop_get_user_data(void)
    408 {
    409 	return eloop.user_data;
    410 }
    411