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 1.2 2003/06/17 04:30:01 dillon Exp $
  30  */
  31
  32 #include <errno.h>
  33 #include <signal.h>
  34 #include <stdarg.h>
  35 #include <stdio.h>
  36 #include <string.h>
  37 #include <sys/time.h>
  38 #include <termios.h>
  39
  40 #include "log.h"
  41 #include "sig.h"
  42 #include "timer.h"
  43 #include "descriptor.h"
  44 #include "prompt.h"
  45
  46
  47 #define RESTVAL(t) \
  48     ((t).it_value.tv_sec * SECTICKS + (t).it_value.tv_usec / TICKUNIT + \
  49      ((((t).it_value.tv_usec % TICKUNIT) >= (TICKUNIT >> 1)) ? 1 : 0))
  50
  51 static struct pppTimer *TimerList = NULL, *ExpiredList = NULL;
  52
  53 static void StopTimerNoBlock(struct pppTimer *);
  54
  55 static const char *
  56 tState2Nam(u_int state)
  57 {
  58   static const char * const StateNames[] = { "stopped", "running", "expired" };
  59
  60   if (state >= sizeof StateNames / sizeof StateNames[0])
  61     return "unknown";
  62   return StateNames[state];
  63 }
  64
  65 void
  66 timer_Stop(struct pppTimer *tp)
  67 {
  68   sigset_t mask, omask;
  69
  70   sigemptyset(&mask);
  71   sigaddset(&mask, SIGALRM);
  72   sigprocmask(SIG_BLOCK, &mask, &omask);
  73   StopTimerNoBlock(tp);
  74   sigprocmask(SIG_SETMASK, &omask, NULL);
  75 }
  76
  77 void
  78 timer_Start(struct pppTimer *tp)
  79 {
  80   struct itimerval itimer;
  81   struct pppTimer *t, *pt;
  82   u_long ticks = 0;
  83   sigset_t mask, omask;
  84
  85   sigemptyset(&mask);
  86   sigaddset(&mask, SIGALRM);
  87   sigprocmask(SIG_BLOCK, &mask, &omask);
  88
  89   if (tp->state != TIMER_STOPPED)
  90     StopTimerNoBlock(tp);
  91
  92   if (tp->load == 0) {
  93     log_Printf(LogTIMER, "%s timer[%p] has 0 load!\n", tp->name, tp);
  94     sigprocmask(SIG_SETMASK, &omask, NULL);
  95     return;
  96   }
  97
  98   /* Adjust our first delta so that it reflects what's really happening */
  99   if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
 100     TimerList->rest = RESTVAL(itimer);
 101
 102   pt = NULL;
 103   for (t = TimerList; t; t = t->next) {
 104     if (ticks + t->rest >= tp->load)
 105       break;
 106     ticks += t->rest;
 107     pt = t;
 108   }
 109
 110   tp->state = TIMER_RUNNING;
 111   tp->rest = tp->load - ticks;
 112
 113   if (t)
 114     log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p] before %s "
 115               "timer[%p], delta = %ld\n", tp->name, tp, t->name, t, tp->rest);
 116   else
 117     log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p]\n", tp->name, tp);
 118
 119   /* Insert given *tp just before *t */
 120   tp->next = t;
 121   if (pt) {
 122     pt->next = tp;
 123   } else {
 124     TimerList = tp;
 125     timer_InitService(t != NULL);       /* [re]Start the Timer Service */
 126   }
 127   if (t)
 128     t->rest -= tp->rest;
 129
 130   sigprocmask(SIG_SETMASK, &omask, NULL);
 131 }
 132
 133 static void
 134 StopTimerNoBlock(struct pppTimer *tp)
 135 {
 136   struct pppTimer *t, *pt;
 137
 138   /*
 139    * A RUNNING timer must be removed from TimerList (->next list).
 140    * A STOPPED timer isn't in any list, but may have a bogus [e]next field.
 141    * An EXPIRED timer is in the ->enext list.
 142    */
 143
 144   if (tp->state == TIMER_STOPPED)
 145     return;
 146
 147   pt = NULL;
 148   for (t = TimerList; t != tp && t != NULL; t = t->next)
 149     pt = t;
 150
 151   if (t) {
 152     if (pt)
 153       pt->next = t->next;
 154     else {
 155       TimerList = t->next;
 156       if (TimerList == NULL)    /* Last one ? */
 157         timer_TermService();    /* Terminate Timer Service */
 158     }
 159     if (t->next) {
 160       if (!pt) {                /* t (tp) was the first in the list */
 161         struct itimerval itimer;
 162
 163         if (getitimer(ITIMER_REAL, &itimer) == 0)
 164           t->rest = RESTVAL(itimer);
 165       }
 166       t->next->rest += t->rest;
 167       if (!pt)                  /* 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
 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
 235 timer_Show(int LogLevel, struct prompt *prompt)
 236 {
 237   struct itimerval itimer;
 238   struct pppTimer *pt;
 239   u_long rest = 0;
 240
 241   /* Adjust our first delta so that it reflects what's really happening */
 242   if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
 243     TimerList->rest = RESTVAL(itimer);
 244
 245 #define SECS(val)       ((val) / SECTICKS)
 246 #define HSECS(val)      (((val) % SECTICKS) * 100 / SECTICKS)
 247 #define DISP                                                            \
 248   "%s timer[%p]: freq = %ld.%02lds, next = %lu.%02lus, state = %s\n",   \
 249   pt->name, pt, SECS(pt->load), HSECS(pt->load), SECS(rest),            \
 250   HSECS(rest), tState2Nam(pt->state)
 251
 252   if (!prompt)
 253     log_Printf(LogLevel, "---- Begin of Timer Service List---\n");
 254
 255   for (pt = TimerList; pt; pt = pt->next) {
 256     rest += pt->rest;
 257     if (prompt)
 258       prompt_Printf(prompt, DISP);
 259     else
 260       log_Printf(LogLevel, DISP);
 261   }
 262
 263   if (!prompt)
 264     log_Printf(LogLevel, "---- End of Timer Service List ---\n");
 265 }
 266
 267 void
 268 timer_InitService(int restart)
 269 {
 270   struct itimerval itimer;
 271
 272   if (TimerList) {
 273     if (!restart)
 274       sig_signal(SIGALRM, (void (*)(int))TimerService);
 275     itimer.it_interval.tv_sec = 0;
 276     itimer.it_interval.tv_usec = 0;
 277     itimer.it_value.tv_sec = TimerList->rest / SECTICKS;
 278     itimer.it_value.tv_usec = (TimerList->rest % SECTICKS) * TICKUNIT;
 279     if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
 280       log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
 281   }
 282 }
 283
 284 void
 285 timer_TermService(void)
 286 {
 287   struct itimerval itimer;
 288
 289   itimer.it_interval.tv_usec = itimer.it_interval.tv_sec = 0;
 290   itimer.it_value.tv_usec = itimer.it_value.tv_sec = 0;
 291   if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
 292     log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
 293   sig_signal(SIGALRM, SIG_IGN);
 294 }