Merge e5fd45a198 into 14245b7c79

Fix infinite loops that prevent graceful termination when the server
receives SIGINT or SIGTERM signals. Without this fix, Ctrl-C and kill
commands are ignored, making it impossible to stop the server cleanly.

Two scenarios cause the infinite loops:

1) The bind() retry loop: When the port is busy, the loop retries
   indefinitely without checking the running flag set by the signal
   handler.

2) The accept() loop: The loop is unconditional, so when accept() is
   interrupted by a signal and returns EINTR, the loop immediately
   restarts, ignoring the shutdown request.

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>

canlogserver.c

@@ -296,6 +296,10 @@ int main(int argc, char **argv)
 		nanosleep(&f, NULL);
 	}
 
+	/*
+	 * Check if loop exited due to signal (during nanosleep) rather than
+	 * successful bind.
+	 */
 	if (!running) {
 		close(socki);
 		return 128 + signal_num;
@@ -321,6 +325,10 @@ int main(int argc, char **argv)
 		}
 	}
 
+	/*
+	 * Check if loop exited due to signal (accept returned EINTR) rather
+	 * than successful fork
+	 */
 	if (!running) {
 		if (accsocket > 0)
 			close(accsocket);

j1939_timedate/j1939_timedate_srv.c

@@ -41,6 +41,7 @@ static void gmtime_to_j1939_pgn_65254_td(struct j1939_time_date_packet *tdp)
 	utc_tm = gmtime_r(&now, &utc_tm_buf);
 	local_tm = localtime_r(&now, &local_tm_buf);
 
+	if (local_tm) {
 		/* Calculate the offsets */
 		hour_offset = local_tm->tm_hour - utc_tm->tm_hour;
 		minute_offset = local_tm->tm_min - utc_tm->tm_min;
@@ -52,6 +53,11 @@ static void gmtime_to_j1939_pgn_65254_td(struct j1939_time_date_packet *tdp)
 			else
 				hour_offset -= 24;  /* before midnight */
 		}
+	} else {
+		/* The local time offsets cannot be determined at the moment */
+		hour_offset = 0xF9;
+		minute_offset = 0xFF;
+	}		
 
 	/*
 	 * Seconds (spn959):