Add support for clean shutdown via SIGTERM

Catch SIGTERM to allow ourselves to do an orderly shutdown. This isn't
useful in general operation (as a TERM will do all this cleanup anyway)
but allows for testing under valgrind to ensure no leaks or invalid
accesses.

diff --git a/mqtt-arp.c b/mqtt-arp.c
index 114e0efff80889fc96e5d0fd406301893f00be38..19da3304117ace9589b3d17cf148cf89484aaaad 100644 (file)
--- a/mqtt-arp.c
+++ b/mqtt-arp.c
@@ -17,6 +17,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 #include <getopt.h>
+#include <signal.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -64,6 +65,12 @@ struct ma_config {
 };
 
 bool debug = false;
+bool want_shutdown = false;
+
+void shutdown_request(int signal)
+{
+       want_shutdown = true;
+}
 
 bool mac_compare(uint8_t *a, uint8_t *b)
 {
@@ -167,7 +174,7 @@ void main_loop(struct ma_config *config, struct mosquitto *mosq, int sock)
 
        hdr = (struct nlmsghdr *) buf;
        nd = (struct ndmsg *) (hdr + 1);
-       while (1) {
+       while (!want_shutdown) {
                received = recv(sock, buf, sizeof(buf), 0);
                if (debug) {
                        t = time(NULL);
@@ -362,8 +369,16 @@ int main(int argc, char *argv[])
        if (!config.location)
                config.mqtt_host = LOCATION;
 
+       signal(SIGTERM, shutdown_request);
+
        sock = netlink_init();
        mosq = mqtt_init(&config);
 
        main_loop(&config, mosq, sock);
+
+       mosquitto_disconnect(mosq);
+       mosquitto_loop_stop(mosq, true);
+       mosquitto_destroy(mosq);
+       mosquitto_lib_cleanup();
+       close(sock);
 }