1 /**
2 * @file
3 * Stack-internal timers implementation.
4 * This file includes timer callbacks for stack-internal timers as well as
5 * functions to set up or stop timers and check for expired timers.
6 *
7 */
8
9 /*
10 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without modification,
14 * are permitted provided that the following conditions are met:
15 *
16 * 1. Redistributions of source code must retain the above copyright notice,
17 * this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright notice,
19 * this list of conditions and the following disclaimer in the documentation
20 * and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
27 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
28 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
29 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
32 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
33 * OF SUCH DAMAGE.
34 *
35 * This file is part of the lwIP TCP/IP stack.
36 *
37 * Author: Adam Dunkels <adam@sics.se>
38 * Simon Goldschmidt
39 *
40 */
41
42 #include "lwip/opt.h"
43
44 #include "lwip/timers.h"
45 #include "lwip/tcp_impl.h"
46
47 #if LWIP_TIMERS
48
49 #include "lwip/def.h"
50 #include "lwip/memp.h"
51 #include "lwip/tcpip.h"
52
53 #include "lwip/ip_frag.h"
54 #include "netif/etharp.h"
55 #include "lwip/dhcp.h"
56 #include "lwip/autoip.h"
57 #include "lwip/igmp.h"
58 #include "lwip/dns.h"
59
60
61 /** The one and only timeout list */
62 static struct sys_timeo *next_timeout;
63 #if NO_SYS
64 static u32_t timeouts_last_time;
65 #endif /* NO_SYS */
66
67 #if LWIP_TCP
68 /** global variable that shows if the tcp timer is currently scheduled or not */
69 static int tcpip_tcp_timer_active;
70
71 /**
72 * Timer callback function that calls tcp_tmr() and reschedules itself.
73 *
74 * @param arg unused argument
75 */
76 static void
tcpip_tcp_timer(void * arg)77 tcpip_tcp_timer(void *arg)
78 {
79 LWIP_UNUSED_ARG(arg);
80
81 /* call TCP timer handler */
82 tcp_tmr();
83 /* timer still needed? */
84 if (tcp_active_pcbs || tcp_tw_pcbs) {
85 /* restart timer */
86 sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL);
87 } else {
88 /* disable timer */
89 tcpip_tcp_timer_active = 0;
90 }
91 }
92
93 /**
94 * Called from TCP_REG when registering a new PCB:
95 * the reason is to have the TCP timer only running when
96 * there are active (or time-wait) PCBs.
97 */
98 void
tcp_timer_needed(void)99 tcp_timer_needed(void)
100 {
101 /* timer is off but needed again? */
102 if (!tcpip_tcp_timer_active && (tcp_active_pcbs || tcp_tw_pcbs)) {
103 /* enable and start timer */
104 tcpip_tcp_timer_active = 1;
105 sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL);
106 }
107 }
108 #endif /* LWIP_TCP */
109
110 #if IP_REASSEMBLY
111 /**
112 * Timer callback function that calls ip_reass_tmr() and reschedules itself.
113 *
114 * @param arg unused argument
115 */
116 static void
ip_reass_timer(void * arg)117 ip_reass_timer(void *arg)
118 {
119 LWIP_UNUSED_ARG(arg);
120 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: ip_reass_tmr()\n"));
121 ip_reass_tmr();
122 sys_timeout(IP_TMR_INTERVAL, ip_reass_timer, NULL);
123 }
124 #endif /* IP_REASSEMBLY */
125
126 #if LWIP_ARP
127 /**
128 * Timer callback function that calls etharp_tmr() and reschedules itself.
129 *
130 * @param arg unused argument
131 */
132 static void
arp_timer(void * arg)133 arp_timer(void *arg)
134 {
135 LWIP_UNUSED_ARG(arg);
136 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: etharp_tmr()\n"));
137 etharp_tmr();
138 undiarp_tmr();
139 sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
140 }
141 #endif /* LWIP_ARP */
142
143 #if LWIP_DHCP
144 /**
145 * Timer callback function that calls dhcp_coarse_tmr() and reschedules itself.
146 *
147 * @param arg unused argument
148 */
149 static void
dhcp_timer_coarse(void * arg)150 dhcp_timer_coarse(void *arg)
151 {
152 LWIP_UNUSED_ARG(arg);
153 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: dhcp_coarse_tmr()\n"));
154 dhcp_coarse_tmr();
155 sys_timeout(DHCP_COARSE_TIMER_MSECS, dhcp_timer_coarse, NULL);
156 }
157
158 /**
159 * Timer callback function that calls dhcp_fine_tmr() and reschedules itself.
160 *
161 * @param arg unused argument
162 */
163 static void
dhcp_timer_fine(void * arg)164 dhcp_timer_fine(void *arg)
165 {
166 LWIP_UNUSED_ARG(arg);
167 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: dhcp_fine_tmr()\n"));
168 dhcp_fine_tmr();
169 sys_timeout(DHCP_FINE_TIMER_MSECS, dhcp_timer_fine, NULL);
170 }
171 #endif /* LWIP_DHCP */
172
173 #if LWIP_AUTOIP
174 /**
175 * Timer callback function that calls autoip_tmr() and reschedules itself.
176 *
177 * @param arg unused argument
178 */
179 static void
autoip_timer(void * arg)180 autoip_timer(void *arg)
181 {
182 LWIP_UNUSED_ARG(arg);
183 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: autoip_tmr()\n"));
184 autoip_tmr();
185 sys_timeout(AUTOIP_TMR_INTERVAL, autoip_timer, NULL);
186 }
187 #endif /* LWIP_AUTOIP */
188
189 #if LWIP_IGMP
190 /**
191 * Timer callback function that calls igmp_tmr() and reschedules itself.
192 *
193 * @param arg unused argument
194 */
195 static void
igmp_timer(void * arg)196 igmp_timer(void *arg)
197 {
198 LWIP_UNUSED_ARG(arg);
199 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: igmp_tmr()\n"));
200 igmp_tmr();
201 sys_timeout(IGMP_TMR_INTERVAL, igmp_timer, NULL);
202 }
203 #endif /* LWIP_IGMP */
204
205 #if LWIP_DNS
206 /**
207 * Timer callback function that calls dns_tmr() and reschedules itself.
208 *
209 * @param arg unused argument
210 */
211 static void
dns_timer(void * arg)212 dns_timer(void *arg)
213 {
214 LWIP_UNUSED_ARG(arg);
215 LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: dns_tmr()\n"));
216 dns_tmr();
217 sys_timeout(DNS_TMR_INTERVAL, dns_timer, NULL);
218 }
219 #endif /* LWIP_DNS */
220
221 /** Initialize this module */
sys_timeouts_init(void)222 void sys_timeouts_init(void)
223 {
224 #if IP_REASSEMBLY
225 sys_timeout(IP_TMR_INTERVAL, ip_reass_timer, NULL);
226 #endif /* IP_REASSEMBLY */
227 #if LWIP_ARP
228 sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
229 #endif /* LWIP_ARP */
230 #if LWIP_DHCP
231 sys_timeout(DHCP_COARSE_TIMER_MSECS, dhcp_timer_coarse, NULL);
232 sys_timeout(DHCP_FINE_TIMER_MSECS, dhcp_timer_fine, NULL);
233 #endif /* LWIP_DHCP */
234 #if LWIP_AUTOIP
235 sys_timeout(AUTOIP_TMR_INTERVAL, autoip_timer, NULL);
236 #endif /* LWIP_AUTOIP */
237 #if LWIP_IGMP
238 sys_timeout(IGMP_TMR_INTERVAL, igmp_timer, NULL);
239 #endif /* LWIP_IGMP */
240 #if LWIP_DNS
241 sys_timeout(DNS_TMR_INTERVAL, dns_timer, NULL);
242 #endif /* LWIP_DNS */
243
244 #if NO_SYS
245 /* Initialise timestamp for sys_check_timeouts */
246 timeouts_last_time = sys_now();
247 #endif
248 }
249
250 /**
251 * Create a one-shot timer (aka timeout). Timeouts are processed in the
252 * following cases:
253 * - while waiting for a message using sys_timeouts_mbox_fetch()
254 * - by calling sys_check_timeouts() (NO_SYS==1 only)
255 *
256 * @param msecs time in milliseconds after that the timer should expire
257 * @param handler callback function to call when msecs have elapsed
258 * @param arg argument to pass to the callback function
259 */
260 #if LWIP_DEBUG_TIMERNAMES
261 void
sys_timeout_debug(u32_t msecs,sys_timeout_handler handler,void * arg,const char * handler_name)262 sys_timeout_debug(u32_t msecs, sys_timeout_handler handler, void *arg, const char* handler_name)
263 #else /* LWIP_DEBUG_TIMERNAMES */
264 void
265 sys_timeout(u32_t msecs, sys_timeout_handler handler, void *arg)
266 #endif /* LWIP_DEBUG_TIMERNAMES */
267 {
268 struct sys_timeo *timeout, *t;
269
270 timeout = (struct sys_timeo *)memp_malloc(MEMP_SYS_TIMEOUT);
271 if (timeout == NULL) {
272 LWIP_ASSERT("sys_timeout: timeout != NULL, pool MEMP_SYS_TIMEOUT is empty", timeout != NULL);
273 return;
274 }
275 timeout->next = NULL;
276 timeout->h = handler;
277 timeout->arg = arg;
278 timeout->time = msecs;
279 #if LWIP_DEBUG_TIMERNAMES
280 timeout->handler_name = handler_name;
281 LWIP_DEBUGF(TIMERS_DEBUG, ("sys_timeout: %p msecs=%"U32_F" handler=%s arg=%p\n",
282 (void *)timeout, msecs, handler_name, (void *)arg));
283 #endif /* LWIP_DEBUG_TIMERNAMES */
284
285 if (next_timeout == NULL) {
286 next_timeout = timeout;
287 return;
288 }
289
290 if (next_timeout->time > msecs) {
291 next_timeout->time -= msecs;
292 timeout->next = next_timeout;
293 next_timeout = timeout;
294 } else {
295 for(t = next_timeout; t != NULL; t = t->next) {
296 timeout->time -= t->time;
297 if (t->next == NULL || t->next->time > timeout->time) {
298 if (t->next != NULL) {
299 t->next->time -= timeout->time;
300 }
301 timeout->next = t->next;
302 t->next = timeout;
303 break;
304 }
305 }
306 }
307 }
308
309 /**
310 * Go through timeout list (for this task only) and remove the first matching
311 * entry, even though the timeout has not triggered yet.
312 *
313 * @note This function only works as expected if there is only one timeout
314 * calling 'handler' in the list of timeouts.
315 *
316 * @param handler callback function that would be called by the timeout
317 * @param arg callback argument that would be passed to handler
318 */
319 void
sys_untimeout(sys_timeout_handler handler,void * arg)320 sys_untimeout(sys_timeout_handler handler, void *arg)
321 {
322 struct sys_timeo *prev_t, *t;
323
324 if (next_timeout == NULL) {
325 return;
326 }
327
328 for (t = next_timeout, prev_t = NULL; t != NULL; prev_t = t, t = t->next) {
329 if ((t->h == handler) && (t->arg == arg)) {
330 /* We have a match */
331 /* Unlink from previous in list */
332 if (prev_t == NULL) {
333 next_timeout = t->next;
334 } else {
335 prev_t->next = t->next;
336 }
337 /* If not the last one, add time of this one back to next */
338 if (t->next != NULL) {
339 t->next->time += t->time;
340 }
341 memp_free(MEMP_SYS_TIMEOUT, t);
342 return;
343 }
344 }
345 return;
346 }
347
348 #if NO_SYS
349
350 /** Handle timeouts for NO_SYS==1 (i.e. without using
351 * tcpip_thread/sys_timeouts_mbox_fetch(). Uses sys_now() to call timeout
352 * handler functions when timeouts expire.
353 *
354 * Must be called periodically from your main loop.
355 */
356 void
sys_check_timeouts(void)357 sys_check_timeouts(void)
358 {
359 struct sys_timeo *tmptimeout;
360 u32_t diff;
361 sys_timeout_handler handler;
362 void *arg;
363 int had_one;
364 u32_t now;
365
366 now = sys_now();
367 if (next_timeout) {
368 /* this cares for wraparounds */
369 diff = LWIP_U32_DIFF(now, timeouts_last_time);
370 do
371 {
372 had_one = 0;
373 tmptimeout = next_timeout;
374 if (tmptimeout->time <= diff) {
375 /* timeout has expired */
376 had_one = 1;
377 timeouts_last_time = now;
378 diff -= tmptimeout->time;
379 next_timeout = tmptimeout->next;
380 handler = tmptimeout->h;
381 arg = tmptimeout->arg;
382 #if LWIP_DEBUG_TIMERNAMES
383 if (handler != NULL) {
384 LWIP_DEBUGF(TIMERS_DEBUG, ("sct calling h=%s arg=%p\n",
385 tmptimeout->handler_name, arg));
386 }
387 #endif /* LWIP_DEBUG_TIMERNAMES */
388 memp_free(MEMP_SYS_TIMEOUT, tmptimeout);
389 if (handler != NULL) {
390 handler(arg);
391 }
392 }
393 /* repeat until all expired timers have been called */
394 }while(had_one);
395 }
396 }
397
398 /** Set back the timestamp of the last call to sys_check_timeouts()
399 * This is necessary if sys_check_timeouts() hasn't been called for a long
400 * time (e.g. while saving energy) to prevent all timer functions of that
401 * period being called.
402 */
403 void
sys_restart_timeouts(void)404 sys_restart_timeouts(void)
405 {
406 timeouts_last_time = sys_now();
407 }
408
409 #else /* NO_SYS */
410
411 /**
412 * Wait (forever) for a message to arrive in an mbox.
413 * While waiting, timeouts are processed.
414 *
415 * @param mbox the mbox to fetch the message from
416 * @param msg the place to store the message
417 */
418 void
sys_timeouts_mbox_fetch(sys_mbox_t * mbox,void ** msg)419 sys_timeouts_mbox_fetch(sys_mbox_t *mbox, void **msg)
420 {
421 u32_t time_needed;
422 struct sys_timeo *tmptimeout;
423 sys_timeout_handler handler;
424 void *arg;
425
426 again:
427 if (!next_timeout) {
428 time_needed = sys_arch_mbox_fetch(mbox, msg, 0);
429 } else {
430 if (next_timeout->time > 0) {
431 time_needed = sys_arch_mbox_fetch(mbox, msg, next_timeout->time);
432 } else {
433 time_needed = SYS_ARCH_TIMEOUT;
434 }
435
436 if (time_needed == SYS_ARCH_TIMEOUT) {
437 /* If time == SYS_ARCH_TIMEOUT, a timeout occured before a message
438 could be fetched. We should now call the timeout handler and
439 deallocate the memory allocated for the timeout. */
440 tmptimeout = next_timeout;
441 next_timeout = tmptimeout->next;
442 handler = tmptimeout->h;
443 arg = tmptimeout->arg;
444 #if LWIP_DEBUG_TIMERNAMES
445 if (handler != NULL) {
446 LWIP_DEBUGF(TIMERS_DEBUG, ("stmf calling h=%s arg=%p\n",
447 tmptimeout->handler_name, arg));
448 }
449 #endif /* LWIP_DEBUG_TIMERNAMES */
450 memp_free(MEMP_SYS_TIMEOUT, tmptimeout);
451 if (handler != NULL) {
452 /* For LWIP_TCPIP_CORE_LOCKING, lock the core before calling the
453 timeout handler function. */
454 LOCK_TCPIP_CORE();
455 handler(arg);
456 UNLOCK_TCPIP_CORE();
457 }
458 LWIP_TCPIP_THREAD_ALIVE();
459
460 /* We try again to fetch a message from the mbox. */
461 goto again;
462 } else {
463 /* If time != SYS_ARCH_TIMEOUT, a message was received before the timeout
464 occured. The time variable is set to the number of
465 milliseconds we waited for the message. */
466 if (time_needed < next_timeout->time) {
467 next_timeout->time -= time_needed;
468 } else {
469 next_timeout->time = 0;
470 }
471 }
472 }
473 }
474
475 #endif /* NO_SYS */
476
477 #else /* LWIP_TIMERS */
478 /* Satisfy the TCP code which calls this function */
479 void
tcp_timer_needed(void)480 tcp_timer_needed(void)
481 {
482 }
483 #endif /* LWIP_TIMERS */
484