Move the call to TimerService() into main.c - just after the select()

call.  The SIGALRM just sets a flag now, preventing the possibility of
any nasty recursivness in the handler itself.

3 files changed, 36 insertions, 1 deletions

diff --git a/usr.sbin/ppp/main.c b/usr.sbin/ppp/main.c
index e70c110..ac8657f 100644
--- a/usr.sbin/ppp/main.c
+++ b/usr.sbin/ppp/main.c
@@ -818,12 +818,22 @@ DoLoop()
     tp = (dial_up && RedialTimer.state != TIMER_RUNNING) ? &timeout : NULL;
     i = select(tun_in+10, &rfds, &wfds, &efds, tp);
 #endif
+
     if ( i == 0 ) {
         continue;
     }
 
     if ( i < 0 ) {
        if ( errno == EINTR ) {
+          if( TimerServiceRequest > 0 ) {
+#ifdef DEBUG
+             logprintf( "Invoking TimerService\n" );
+#endif
+             /* Maybe a bit cautious.... */
+             TimerServiceRequest = -1;
+             TimerService();
+             TimerServiceRequest = 0;
+          }
           continue;            /* Got SIGALRM, Do check a queue for dialing */
        }
        perror("select");
diff --git a/usr.sbin/ppp/timeout.h b/usr.sbin/ppp/timeout.h
index 1da38ef..afba12a 100644
--- a/usr.sbin/ppp/timeout.h
+++ b/usr.sbin/ppp/timeout.h
@@ -42,6 +42,7 @@ struct pppTimer {
 #define	TIMER_EXPIRED	2
 
 struct pppTimer *TimerList;
+extern int TimerServiceRequest;	/* If this is >0, call TimerService() */
 
 extern void StartTimer __P((struct pppTimer *));
 extern void StopTimer __P((struct pppTimer *));
diff --git a/usr.sbin/ppp/timer.c b/usr.sbin/ppp/timer.c
index be3e80b..b9f0acf 100644
--- a/usr.sbin/ppp/timer.c
+++ b/usr.sbin/ppp/timer.c
@@ -138,6 +138,24 @@ struct pppTimer *tp;
   tp->state = TIMER_STOPPED;
 }
 
+/*
+  This is used to decide at the top level if it's time for a TimerService()
+  call.  This'll work fine as long as select() is interrupted by the
+  SIGALRM.
+*/
+int TimerServiceRequest = 0;
+
+void
+SetTimerServiceRequest( int Sig )
+{
+  /* Maybe a bit cautious.... */
+  if( TimerServiceRequest >= 0 )
+    TimerServiceRequest++;
+#ifdef DEBUG
+  logprintf( "Setting TimerServiceRequest\n" );
+#endif
+}
+
 void
 TimerService()
 {
@@ -269,7 +287,13 @@ void usleep( u_int usec)
 void InitTimerService( void ) {
   struct itimerval itimer;
 
-  signal(SIGALRM, (void (*)(int))TimerService);
+  /*
+     Let's not do this - it's a bit dangerous (potential recursion into the
+     likes of malloc() etc.
+
+     signal(SIGALRM, (void (*)(int))TimerService);
+  */
+  signal(SIGALRM, SetTimerServiceRequest);
   itimer.it_interval.tv_sec = itimer.it_value.tv_sec = 0;
   itimer.it_interval.tv_usec = itimer.it_value.tv_usec = TICKUNIT;
   setitimer(ITIMER_REAL, &itimer, NULL);