2004-11-23 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
* sigevent.c: (signal_init) Set up some default signal handlers
so that processes will issue an error message before terminating
or dumping core.
(trap_default_signals) New function to set up signal handlers
for various signals that may kill the process.
(exit_handler) Call zlog_signal, then _exit.
(core_handler) Call zlog_signal, then abort.
* log.h: Declare new function zlog_signal.
* log.c: (zlog_signal) New function to log information about
a received signal before the process dies. Try to log a
backtrace also.
(quagga_signal_handler,signal_set) Should be static.
diff --git a/lib/sigevent.c b/lib/sigevent.c
index 937180c..53503a7 100644
--- a/lib/sigevent.c
+++ b/lib/sigevent.c
@@ -37,7 +37,7 @@
/* Generic signal handler
* Schedules signal event thread
*/
-void
+static void
quagga_signal_handler (int signo)
{
int i;
@@ -125,7 +125,7 @@
/* Initialization of signal handles. */
/* Signale wrapper. */
-int
+static int
signal_set (int signo)
{
int ret;
@@ -152,6 +152,93 @@
return 0;
}
+static void
+exit_handler(int signo)
+{
+ zlog_signal(signo,"exiting...");
+ _exit(128+signo);
+}
+
+static void
+core_handler(int signo)
+{
+ zlog_signal(signo,"aborting...");
+ abort();
+}
+
+static void
+trap_default_signals(void)
+{
+ static const int core_signals[] = {
+ SIGQUIT,
+ SIGILL,
+#ifdef SIGEMT
+ SIGEMT,
+#endif
+ SIGFPE,
+ SIGBUS,
+ SIGSEGV,
+#ifdef SIGSYS
+ SIGSYS,
+#endif
+#ifdef SIGXCPU
+ SIGXCPU,
+#endif
+#ifdef SIGXFSZ
+ SIGXFSZ,
+#endif
+ };
+ static const int exit_signals[] = {
+ SIGHUP,
+ SIGINT,
+ SIGPIPE,
+ SIGALRM,
+ SIGTERM,
+ SIGUSR1,
+ SIGUSR2,
+#ifdef SIGPOLL
+ SIGPOLL,
+#endif
+#ifdef SIGVTALRM
+ SIGVTALRM,
+#endif
+#ifdef SIGSTKFLT
+ SIGSTKFLT,
+#endif
+ };
+ static const struct {
+ const int *sigs;
+ int nsigs;
+ void (*handler)(int);
+ } sigmap[2] = {
+ { core_signals, sizeof(core_signals)/sizeof(core_signals[0]),core_handler },
+ { exit_signals, sizeof(exit_signals)/sizeof(exit_signals[0]),exit_handler },
+ };
+ int i;
+
+ for (i = 0; i < 2; i++)
+ {
+ int j;
+
+ for (j = 0; j < sigmap[i].nsigs; j++)
+ {
+ struct sigaction oact;
+ if ((sigaction(sigmap[i].sigs[j],NULL,&oact) == 0) &&
+ (oact.sa_handler == SIG_DFL))
+ {
+ struct sigaction act;
+ act.sa_handler = sigmap[i].handler;
+ sigfillset (&act.sa_mask);
+ act.sa_flags = 0;
+ if (sigaction(sigmap[i].sigs[j],&act,NULL) < 0)
+ zlog_warn("Unable to set signal handler for signal %d: %s",
+ sigmap[i].sigs[j],safe_strerror(errno));
+
+ }
+ }
+ }
+}
+
void
signal_init (struct thread_master *m, int sigc,
struct quagga_signal_t signals[])
@@ -159,6 +246,10 @@
int i = 0;
struct quagga_signal_t *sig;
+
+ /* First establish some default handlers that can be overridden by
+ the application. */
+ trap_default_signals();
while (i < sigc)
{