lib: Add a Dev catch for when a timer is set for > 1 year

Since there are timers that are created based upon doing some
math and we know that unsigned values when doing math and we accidently
subtract a larger number from a smaller number causes the unsigned
number to wrap to very large numbers, let's put in a small catch
in place to see if there are any places in the system that
mistakes are made and FRR is accidently creating a problem
for itself.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

lib/lib_errors.c

@@ -68,6 +68,12 @@ static struct log_ref ferr_lib_warn[] = {
 		.description = "The Event subsystem has detected a file descriptor read/write event without an associated handling function.  This is a bug, please collect log data and open an issue.",
 		.suggestion = "Gather log data and open an Issue",
 	},
+	{
+		.code = EC_LIB_TIMER_TOO_LONG,
+		.title = "The Event subsystem has detected an internal timer that is scheduled to pop in greater than one year",
+		.description = "The Event subsystem has detected a timer being started that will pop in a timer that is greater than one year.  This is a bug, please collect log data and open an issue.",
+		.suggestion = "Gather log data and open an Issue",
+	},
 	{
 		.code = EC_LIB_RMAP_RECURSION_LIMIT,
 		.title = "Reached the Route-Map Recursion Limit",

lib/lib_errors.h

@@ -48,6 +48,7 @@ enum lib_log_refs {
 	EC_LIB_SLOW_THREAD_WALL,
 	EC_LIB_STARVE_THREAD,
 	EC_LIB_NO_THREAD,
+	EC_LIB_TIMER_TOO_LONG,
 	EC_LIB_RMAP_RECURSION_LIMIT,
 	EC_LIB_BACKUP_CONFIG,
 	EC_LIB_VRF_LENGTH,

lib/thread.c

@@ -1052,6 +1052,12 @@ static void _thread_add_timer_timeval(const struct xref_threadsched *xref,
 		if (thread_timer_list_first(&m->timer) == thread)
 			AWAKEN(m);
 	}
+#define ONEYEAR2SEC (60 * 60 * 24 * 365)
+	if (time_relative->tv_sec > ONEYEAR2SEC)
+		flog_err(
+			EC_LIB_TIMER_TOO_LONG,
+			"Timer: %pTHD is created with an expiration that is greater than 1 year",
+			thread);
 }