1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1996 - 2001, 2009 Brian Somers <brian@Awfulhak.org>
5 * based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
6 * Internet Initiative Japan, Inc (IIJ)
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <errno.h>
32 #include <signal.h>
33 #include <stdarg.h>
34 #include <stdio.h>
35 #include <string.h>
36 #include <sys/time.h>
37 #include <termios.h>
38
39 #include "log.h"
40 #include "sig.h"
41 #include "timer.h"
42 #include "descriptor.h"
43 #include "prompt.h"
44
45
46 #define RESTVAL(t) \
47 ((t).it_value.tv_sec * SECTICKS + (t).it_value.tv_usec / TICKUNIT + \
48 ((((t).it_value.tv_usec % TICKUNIT) >= (TICKUNIT >> 1)) ? 1 : 0))
49
50 static struct pppTimer *TimerList = NULL, *ExpiredList = NULL;
51
52 static void StopTimerNoBlock(struct pppTimer *);
53
54 static const char *
tState2Nam(u_int state)55 tState2Nam(u_int state)
56 {
57 static const char * const StateNames[] = { "stopped", "running", "expired" };
58
59 if (state >= sizeof StateNames / sizeof StateNames[0])
60 return "unknown";
61 return StateNames[state];
62 }
63
64 void
timer_Stop(struct pppTimer * tp)65 timer_Stop(struct pppTimer *tp)
66 {
67 sigset_t mask, omask;
68
69 sigemptyset(&mask);
70 sigaddset(&mask, SIGALRM);
71 sigprocmask(SIG_BLOCK, &mask, &omask);
72 StopTimerNoBlock(tp);
73 sigprocmask(SIG_SETMASK, &omask, NULL);
74 }
75
76 void
timer_Start(struct pppTimer * tp)77 timer_Start(struct pppTimer *tp)
78 {
79 struct itimerval itimer;
80 struct pppTimer *t, *pt;
81 u_long ticks = 0;
82 sigset_t mask, omask;
83
84 sigemptyset(&mask);
85 sigaddset(&mask, SIGALRM);
86 sigprocmask(SIG_BLOCK, &mask, &omask);
87
88 if (tp->state != TIMER_STOPPED)
89 StopTimerNoBlock(tp);
90
91 if (tp->load == 0) {
92 log_Printf(LogTIMER, "%s timer[%p] has 0 load!\n", tp->name, tp);
93 sigprocmask(SIG_SETMASK, &omask, NULL);
94 return;
95 }
96
97 /*
98 * We just need to insert tp in the correct relative place. We don't
99 * need to adjust TimerList->rest (yet).
100 */
101 if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
102 ticks = RESTVAL(itimer) - TimerList->rest;
103
104 pt = NULL;
105 for (t = TimerList; t; t = t->next) {
106 if (ticks + t->rest >= tp->load)
107 break;
108 ticks += t->rest;
109 pt = t;
110 }
111
112 tp->state = TIMER_RUNNING;
113 tp->rest = tp->load - ticks;
114
115 if (t)
116 log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p] before %s "
117 "timer[%p], delta = %ld\n", tp->name, tp, t->name, t, tp->rest);
118 else
119 log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p]\n", tp->name, tp);
120
121 /* Insert given *tp just before *t */
122 tp->next = t;
123 if (pt) {
124 pt->next = tp;
125 } else {
126 TimerList = tp;
127 timer_InitService(t != NULL); /* [re]Start the Timer Service */
128 }
129 if (t)
130 t->rest -= tp->rest;
131
132 sigprocmask(SIG_SETMASK, &omask, NULL);
133 }
134
135 static void
StopTimerNoBlock(struct pppTimer * tp)136 StopTimerNoBlock(struct pppTimer *tp)
137 {
138 struct itimerval itimer;
139 struct pppTimer *t, *pt;
140
141 /*
142 * A RUNNING timer must be removed from TimerList (->next list).
143 * A STOPPED timer isn't in any list, but may have a bogus [e]next field.
144 * An EXPIRED timer is in the ->enext list.
145 */
146
147 if (tp->state == TIMER_STOPPED)
148 return;
149
150 pt = NULL;
151 for (t = TimerList; t != tp && t != NULL; t = t->next)
152 pt = t;
153
154 if (t) {
155 if (pt)
156 pt->next = t->next;
157 else {
158 TimerList = t->next;
159 if (TimerList == NULL) /* Last one ? */
160 timer_TermService(); /* Terminate Timer Service */
161 }
162 if (t->next) {
163 if (!pt && getitimer(ITIMER_REAL, &itimer) == 0)
164 t->next->rest += RESTVAL(itimer); /* t (tp) was the first in the list */
165 else
166 t->next->rest += t->rest;
167 if (!pt && t->next->rest > 0) /* t->next is now the first in the list */
168 timer_InitService(1);
169 }
170 } else {
171 /* Search for any pending expired timers */
172 pt = NULL;
173 for (t = ExpiredList; t != tp && t != NULL; t = t->enext)
174 pt = t;
175
176 if (t) {
177 if (pt)
178 pt->enext = t->enext;
179 else
180 ExpiredList = t->enext;
181 } else if (tp->state == TIMER_RUNNING)
182 log_Printf(LogERROR, "Oops, %s timer not found!!\n", tp->name);
183 }
184
185 tp->next = tp->enext = NULL;
186 tp->state = TIMER_STOPPED;
187 }
188
189 static void
TimerService(void)190 TimerService(void)
191 {
192 struct pppTimer *tp, *exp, *next;
193
194 if (log_IsKept(LogTIMER)) {
195 static time_t t; /* Only show timers globally every second */
196 time_t n = time(NULL);
197
198 if (n > t)
199 timer_Show(LogTIMER, NULL);
200 t = n;
201 }
202
203 tp = TimerList;
204 if (tp) {
205 tp->rest = 0;
206
207 /* Multiple timers might expire at once. Create a list of expired timers */
208 exp = NULL;
209 do {
210 tp->state = TIMER_EXPIRED;
211 next = tp->next;
212 tp->enext = exp;
213 exp = tp;
214 tp = next;
215 } while (tp && tp->rest == 0);
216
217 TimerList = tp;
218 if (TimerList != NULL) /* Any timers remaining ? */
219 timer_InitService(1); /* Restart the Timer Service */
220 else
221 timer_TermService(); /* Stop the Timer Service */
222
223 /* Process all expired timers */
224 while (exp) {
225 ExpiredList = exp->enext;
226 exp->enext = NULL;
227 if (exp->func)
228 (*exp->func)(exp->arg);
229 exp = ExpiredList;
230 }
231 }
232 }
233
234 void
timer_Show(int LogLevel,struct prompt * prompt)235 timer_Show(int LogLevel, struct prompt *prompt)
236 {
237 struct itimerval itimer;
238 struct pppTimer *pt;
239 long rest;
240
241 /*
242 * Adjust the base time so that the deltas reflect what's really
243 * happening. Changing TimerList->rest might cause it to become zero
244 * (if getitimer() returns a value close to zero), and the
245 * timer_InitService() call will call setitimer() with zero it_value,
246 * stopping the itimer... so be careful!
247 */
248 if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
249 rest = RESTVAL(itimer) - TimerList->rest;
250 else
251 rest = 0;
252
253 #define SECS(val) ((val) / SECTICKS)
254 #define HSECS(val) (((val) % SECTICKS) * 100 / SECTICKS)
255 #define DISP \
256 "%s timer[%p]: freq = %ld.%02lds, next = %lu.%02lus, state = %s\n", \
257 pt->name, pt, SECS(pt->load), HSECS(pt->load), SECS(rest), \
258 HSECS(rest), tState2Nam(pt->state)
259
260 if (!prompt)
261 log_Printf(LogLevel, "---- Begin of Timer Service List---\n");
262
263 for (pt = TimerList; pt; pt = pt->next) {
264 rest += pt->rest;
265 if (prompt)
266 prompt_Printf(prompt, DISP);
267 else
268 log_Printf(LogLevel, DISP);
269 }
270
271 if (!prompt)
272 log_Printf(LogLevel, "---- End of Timer Service List ---\n");
273 }
274
275 void
timer_InitService(int restart)276 timer_InitService(int restart)
277 {
278 struct itimerval itimer;
279
280 if (TimerList) {
281 if (!restart)
282 sig_signal(SIGALRM, (void (*)(int))TimerService);
283 itimer.it_interval.tv_sec = 0;
284 itimer.it_interval.tv_usec = 0;
285 itimer.it_value.tv_sec = TimerList->rest / SECTICKS;
286 itimer.it_value.tv_usec = (TimerList->rest % SECTICKS) * TICKUNIT;
287 if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
288 log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
289 }
290 }
291
292 void
timer_TermService(void)293 timer_TermService(void)
294 {
295 struct itimerval itimer;
296
297 itimer.it_interval.tv_usec = itimer.it_interval.tv_sec = 0;
298 itimer.it_value.tv_usec = itimer.it_value.tv_sec = 0;
299 if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
300 log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
301 sig_signal(SIGALRM, SIG_IGN);
302 }
303