Add signal handling: SIGUSR1 - dump cache; SIGHUP - restart server

mdns.h

@@ -86,6 +86,7 @@ void mdns_show_meminfo(void);
 #else
   #define DEBUG_PRINTF(...) ((void) 0)
 #endif
+#define MDNS_RR_DEBUG_PRINTF(...) printf(__VA_ARGS__)
 
 
 struct rr_data_srv {

mdnsd.c

@@ -128,6 +128,7 @@ struct mdnsd {
 	int sockfd;
 	int notify_pipe[2];
 	int stop_flag;
+	int dump_cache;
 	int sendmsg_requested;
 	int domain;
 
@@ -174,13 +175,13 @@ static void log_message(int loglevel, char *fmt_str, ...) {
 	fprintf(stderr, "%s\n", buf);
 }
 
-#ifdef MDNSD_RR_DEBUG
+//#ifdef MDNSD_RR_DEBUG
 static void print_rr_entry(struct rr_entry *rr_e)
 {
 	char *str1, *str2;
 
 	if (!rr_e) {
-		DEBUG_PRINTF("ERROR: No RR Entry\n");
+		MDNS_RR_DEBUG_PRINTF("ERROR: No RR Entry\n");
 		return;
 	}
 
@@ -198,12 +199,12 @@ static void print_rr_entry(struct rr_entry *rr_e)
 		str2 = NULL;
 	}
 
-	DEBUG_PRINTF("type:%s, ttl=%d, time=%d, ca_fl=%d, rr_class=%d, name=[%s]", rr_get_type_name(rr_e->type), rr_e->ttl, (unsigned int)(time(NULL) - rr_e->update_time), (int)rr_e->cache_flush, rr_e->rr_class, str1 ? str1 : "NULL");
+	MDNS_RR_DEBUG_PRINTF("type:%s, ttl=%d, time=%d, ca_fl=%d, rr_class=%d, name=[%s]", rr_get_type_name(rr_e->type), rr_e->ttl, (unsigned int)(time(NULL) - rr_e->update_time), (int)rr_e->cache_flush, rr_e->rr_class, str1 ? str1 : "NULL");
 
 	if (rr_e->type == RR_SRV || rr_e->type == RR_PTR) {
-		DEBUG_PRINTF(", target=[%s]\n", str2 ? str2 : "NULL");
+		MDNS_RR_DEBUG_PRINTF(", target=[%s]\n", str2 ? str2 : "NULL");
 	} else {
-		DEBUG_PRINTF("\n");
+		MDNS_RR_DEBUG_PRINTF("\n");
 	}
 
 	if (str1) {
@@ -216,15 +217,17 @@ static void print_rr_entry(struct rr_entry *rr_e)
 
 static void print_cache(struct mdnsd *svr)
 {
-	DEBUG_PRINTF("\n");
+	MDNS_RR_DEBUG_PRINTF("\n");
-	DEBUG_PRINTF(" Multicast DNS Cache\n");
+	MDNS_RR_DEBUG_PRINTF(" Multicast DNS Cache\n");
 
 	for (struct rr_group *group = svr->cache; group; group = group->next) {
 		char *pname = group->name? nlabel_to_str(group->name): NULL;
 
-		DEBUG_PRINTF("==================================================\n");
+		MDNS_RR_DEBUG_PRINTF(
-		DEBUG_PRINTF(" Group: %s\n", pname ? pname : "Unknown");
+			"==================================================\n"
-		DEBUG_PRINTF("==================================================\n");
+			" Group: %s\n"
+			"==================================================\n",
+			pname ? pname : "Unknown");
 		if (pname) {
 			MDNS_FREE(pname);
 		}
@@ -236,10 +239,9 @@ static void print_cache(struct mdnsd *svr)
 			}
 		}
 	}
-	DEBUG_PRINTF("==================================================\n");
+	MDNS_RR_DEBUG_PRINTF("==================================================\n\n");
-	DEBUG_PRINTF("\n");
 }
-#endif							/* MDNSD_RR_DEBUG */
+//#endif							/* MDNSD_RR_DEBUG */
 
 static int check_mdns_domain(const char *name)
 {
@@ -1252,7 +1254,7 @@ static void main_loop(struct mdnsd *svr) {
 					continue;
 				}
 
-				DEBUG_PRINTF("data from=%s:%d size=%ld\n", inet_ntoa(fromaddr.sin_addr), (long) recvsize);
+				DEBUG_PRINTF("data from=%s:%d size=%ld\n", inet_ntoa(fromaddr.sin_addr), ntohl(fromaddr.sin_port), (long) recvsize);
 				struct mdns_pkt *mdns = mdns_parse_pkt(pkt_buffer, recvsize);
 				if (mdns != NULL) {
 					struct sockaddr_in toaddr = fromaddr;
@@ -1356,6 +1358,11 @@ static void main_loop(struct mdnsd *svr) {
 				break;			/* exit main_loop */
 			sem_post(&svr->sendmsg_sem);
 		}
+
+		if (svr->dump_cache) {
+			svr->dump_cache = 0;
+			print_cache(svr);
+		}
 	}
 
 	if (svr->sendmsg_requested && svr->stop_flag) {
@@ -1793,6 +1800,7 @@ static int init_mdns_context(int domain)
 	pthread_mutex_init(&g_svr->data_lock, NULL);
 	sem_init(&g_svr->sendmsg_sem, 0, 0);
 	g_svr->sendmsg_requested = 1;
+	g_svr->dump_cache= 0;
 
 	/* init thread */
 	if (pthread_attr_init(&attr) != 0) {
@@ -2001,6 +2009,11 @@ static void mdns_cmd_mutex_unlock(void)
 	}
 }
 
+static void handler_dump_cache(int sig) {
+	(void)sig;
+	g_svr->dump_cache = 1;
+}
+
 /////////////////////////////////////////////////////
 // Public Functions
 /////////////////////////////////////////////////////
@@ -2043,6 +2056,8 @@ int mdnsd_start(const char *desired_hostname, const char *netif_nameOrAddress)
 		goto out_with_mutex;
 	}
 
+	signal(SIGUSR1, handler_dump_cache);
+
 	/* success */
 	result = 0;
 

testmdnsd.c

@@ -32,6 +32,7 @@
 #include <strings.h>
 #include <unistd.h>
 #include <errno.h>
+#include <signal.h>
 
 #ifdef _WIN32
 #include <winsock2.h>
@@ -275,13 +276,30 @@ void dump_hosts(const struct hostent * hostents) {
 	}
 }
 
+static void handler_stop(int sig) {
+	(void)sig;
+	mdnsd_stop();
+#ifdef WIN32
+	winsock_close();
+#endif
+	exit(0);
+}
+
+volatile static int running;
+
+static void handler_restart(int sig) {
+	/* a dummy handler so that sleep() will end early */
+	(void)sig;
+	if (running != 0) 
+		running = 2;
+}
+
 int
 main(int argc, char **argv)
 {
 	char hostname[0x100], ifname[0x120], fullname[0x108];
 
 	struct in_addr saddr;
-	int notrunning = 1;
 
 	if (gethostname(hostname, sizeof(hostname) - 1) == -1)
 	{
@@ -300,6 +318,21 @@ main(int argc, char **argv)
 					NULL
 						};
 
+	running = 0;
+	
+	signal(SIGINT, handler_stop);
+	signal(SIGTERM, handler_stop);
+#if defined(SIGPIPE)
+	signal(SIGPIPE, SIG_IGN);
+#endif
+#if defined(SIGQUIT)
+	signal(SIGQUIT, handler_stop);
+#endif
+#if defined(SIGHUP)
+	signal(SIGHUP, handler_restart);
+#endif
+
+
 	for (saddr.s_addr = 0;;sleep(61)) {
 		struct hostent *hp = gethostbyname(hostname);
 		char * ip_addr;
@@ -310,8 +343,8 @@ main(int argc, char **argv)
 			return 1;
 		}
 		
-		if (saddr.s_addr != *(in_addr_t *)(hp->h_addr_list[0])) {
+		if (running != 1 || saddr.s_addr != *(in_addr_t *)(hp->h_addr_list[0])) {
-			if ((notrunning == 0) && (0 > mdnsd_stop())) {
+			if (running && (0 > mdnsd_stop())) {
 				fprintf(stderr, "mdnsd_stop() error\n");
 				return 1;
 			}
@@ -326,7 +359,7 @@ main(int argc, char **argv)
 				fprintf(stderr, "mdnsd_start() error\n");
 				return 1;
 			}
-			notrunning = 0;
+			running = 1;
 
 			/* service must have FQDN */
 			if (0 <= mdnsd_register_service(
@@ -340,6 +373,7 @@ main(int argc, char **argv)
 
 		if (0 <= mdnsd_discover_service("_http._tcp.local", 5000, &svcinfo, &numserv)) {
 			
+			/* allow an extra entry for own host */
 			struct hostent * hosts = read_hosts(numserv+1);
 			if (!hosts) {
 				fprintf(stderr,"null hosts\n");
@@ -362,7 +396,7 @@ main(int argc, char **argv)
 		}
 	}	
 
-	if ((notrunning == 0) && (0 > mdnsd_stop())) {
+	if (running && (0 > mdnsd_stop())) {
 		fprintf(stderr,"mdnsd_stop() error\n");
 	}