usr.sbin/ppp/timer.c

   1 /*-
   2  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
   3  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
   4  *                           Internet Initiative Japan, Inc (IIJ)
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/usr.sbin/ppp/timer.c,v 1.38.2.3 2002/09/01 02:12:32 brian Exp $
  29  * $DragonFly: src/usr.sbin/ppp/timer.c,v 1.3 2008/05/19 10:19:49 corecode Exp $
  30  */
  31
  32 #include <sys/select.h>
  33
  34 #include <errno.h>
  35 #include <signal.h>
  36 #include <stdarg.h>
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <sys/time.h>
  40 #include <termios.h>
  41
  42 #include "log.h"
  43 #include "sig.h"
  44 #include "timer.h"
  45 #include "descriptor.h"
  46 #include "prompt.h"
  47
  48
  49 #define RESTVAL(t) \
  50     ((t).it_value.tv_sec * SECTICKS + (t).it_value.tv_usec / TICKUNIT + \
  51      ((((t).it_value.tv_usec % TICKUNIT) >= (TICKUNIT >> 1)) ? 1 : 0))
  52
  53 static struct pppTimer *TimerList = NULL, *ExpiredList = NULL;
  54
  55 static void StopTimerNoBlock(struct pppTimer *);
  56
  57 static const char *
  58 tState2Nam(u_int state)
  59 {
  60   static const char * const StateNames[] = { "stopped", "running", "expired" };
  61
  62   if (state >= sizeof StateNames / sizeof StateNames[0])
  63     return "unknown";
  64   return StateNames[state];
  65 }
  66
  67 void
  68 timer_Stop(struct pppTimer *tp)
  69 {
  70   sigset_t mask, omask;
  71
  72   sigemptyset(&mask);
  73   sigaddset(&mask, SIGALRM);
  74   sigprocmask(SIG_BLOCK, &mask, &omask);
  75   StopTimerNoBlock(tp);
  76   sigprocmask(SIG_SETMASK, &omask, NULL);
  77 }
  78
  79 void
  80 timer_Start(struct pppTimer *tp)
  81 {
  82   struct itimerval itimer;
  83   struct pppTimer *t, *pt;
  84   u_long ticks = 0;
  85   sigset_t mask, omask;
  86
  87   sigemptyset(&mask);
  88   sigaddset(&mask, SIGALRM);
  89   sigprocmask(SIG_BLOCK, &mask, &omask);
  90
  91   if (tp->state != TIMER_STOPPED)
  92     StopTimerNoBlock(tp);
  93
  94   if (tp->load == 0) {
  95     log_Printf(LogTIMER, "%s timer[%p] has 0 load!\n", tp->name, tp);
  96     sigprocmask(SIG_SETMASK, &omask, NULL);
  97     return;
  98   }
  99
 100   /* Adjust our first delta so that it reflects what's really happening */
 101   if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
 102     TimerList->rest = RESTVAL(itimer);
 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
 136 StopTimerNoBlock(struct pppTimer *tp)
 137 {
 138   struct pppTimer *t, *pt;
 139
 140   /*
 141    * A RUNNING timer must be removed from TimerList (->next list).
 142    * A STOPPED timer isn't in any list, but may have a bogus [e]next field.
 143    * An EXPIRED timer is in the ->enext list.
 144    */
 145
 146   if (tp->state == TIMER_STOPPED)
 147     return;
 148
 149   pt = NULL;
 150   for (t = TimerList; t != tp && t != NULL; t = t->next)
 151     pt = t;
 152
 153   if (t) {
 154     if (pt)
 155       pt->next = t->next;
 156     else {
 157       TimerList = t->next;
 158       if (TimerList == NULL)    /* Last one ? */
 159         timer_TermService();    /* Terminate Timer Service */
 160     }
 161     if (t->next) {
 162       if (!pt) {                /* t (tp) was the first in the list */
 163         struct itimerval itimer;
 164
 165         if (getitimer(ITIMER_REAL, &itimer) == 0)
 166           t->rest = RESTVAL(itimer);
 167       }
 168       t->next->rest += t->rest;
 169       if (!pt)                  /* t->next is now the first in the list */
 170         timer_InitService(1);
 171     }
 172   } else {
 173     /* Search for any pending expired timers */
 174     pt = NULL;
 175     for (t = ExpiredList; t != tp && t != NULL; t = t->enext)
 176       pt = t;
 177
 178     if (t) {
 179       if (pt)
 180         pt->enext = t->enext;
 181       else
 182         ExpiredList = t->enext;
 183     } else if (tp->state == TIMER_RUNNING)
 184       log_Printf(LogERROR, "Oops, %s timer not found!!\n", tp->name);
 185   }
 186
 187   tp->next = tp->enext = NULL;
 188   tp->state = TIMER_STOPPED;
 189 }
 190
 191 static void
 192 TimerService(void)
 193 {
 194   struct pppTimer *tp, *exp, *next;
 195
 196   if (log_IsKept(LogTIMER)) {
 197     static time_t t;            /* Only show timers globally every second */
 198     time_t n = time(NULL);
 199
 200     if (n > t)
 201       timer_Show(LogTIMER, NULL);
 202     t = n;
 203   }
 204
 205   tp = TimerList;
 206   if (tp) {
 207     tp->rest = 0;
 208
 209     /* Multiple timers might expire at once. Create a list of expired timers */
 210     exp = NULL;
 211     do {
 212       tp->state = TIMER_EXPIRED;
 213       next = tp->next;
 214       tp->enext = exp;
 215       exp = tp;
 216       tp = next;
 217     } while (tp && tp->rest == 0);
 218
 219     TimerList = tp;
 220     if (TimerList != NULL)      /* Any timers remaining ? */
 221       timer_InitService(1);     /* Restart the Timer Service */
 222     else
 223       timer_TermService();      /* Stop the Timer Service */
 224
 225     /* Process all expired timers */
 226     while (exp) {
 227       ExpiredList = exp->enext;
 228       exp->enext = NULL;
 229       if (exp->func)
 230         (*exp->func)(exp->arg);
 231       exp = ExpiredList;
 232     }
 233   }
 234 }
 235
 236 void
 237 timer_Show(int LogLevel, struct prompt *prompt)
 238 {
 239   struct itimerval itimer;
 240   struct pppTimer *pt;
 241   u_long rest = 0;
 242
 243   /* Adjust our first delta so that it reflects what's really happening */
 244   if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
 245     TimerList->rest = RESTVAL(itimer);
 246
 247 #define SECS(val)       ((val) / SECTICKS)
 248 #define HSECS(val)      (((val) % SECTICKS) * 100 / SECTICKS)
 249 #define DISP                                                            \
 250   "%s timer[%p]: freq = %ld.%02lds, next = %lu.%02lus, state = %s\n",   \
 251   pt->name, pt, SECS(pt->load), HSECS(pt->load), SECS(rest),            \
 252   HSECS(rest), tState2Nam(pt->state)
 253
 254   if (!prompt)
 255     log_Printf(LogLevel, "---- Begin of Timer Service List---\n");
 256
 257   for (pt = TimerList; pt; pt = pt->next) {
 258     rest += pt->rest;
 259     if (prompt)
 260       prompt_Printf(prompt, DISP);
 261     else
 262       log_Printf(LogLevel, DISP);
 263   }
 264
 265   if (!prompt)
 266     log_Printf(LogLevel, "---- End of Timer Service List ---\n");
 267 }
 268
 269 void
 270 timer_InitService(int restart)
 271 {
 272   struct itimerval itimer;
 273
 274   if (TimerList) {
 275     if (!restart)
 276       sig_signal(SIGALRM, (void (*)(int))TimerService);
 277     itimer.it_interval.tv_sec = 0;
 278     itimer.it_interval.tv_usec = 0;
 279     itimer.it_value.tv_sec = TimerList->rest / SECTICKS;
 280     itimer.it_value.tv_usec = (TimerList->rest % SECTICKS) * TICKUNIT;
 281     if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
 282       log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
 283   }
 284 }
 285
 286 void
 287 timer_TermService(void)
 288 {
 289   struct itimerval itimer;
 290
 291   itimer.it_interval.tv_usec = itimer.it_interval.tv_sec = 0;
 292   itimer.it_value.tv_usec = itimer.it_value.tv_sec = 0;
 293   if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
 294     log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
 295   sig_signal(SIGALRM, SIG_IGN);
 296 }