Decouple DNS-based seed discovery from the broadcast timer.

src/ssb.c

@@ -77,6 +77,9 @@ enum
 	k_tf_ssb_rpc_message_body_length_max = 1 * 1024 * 1024,
 	k_debug_close_message_count = 256,
 	k_debug_close_connection_count = 32,
+	k_seed_expire_seconds = 10 * 60,
+	k_seed_check_interval_seconds = 5 * 50,
+	k_udp_discovery_expires_seconds = 10,
 };
 
 typedef struct _tf_ssb_broadcast_t tf_ssb_broadcast_t;
@@ -116,6 +119,7 @@ typedef struct _tf_ssb_broadcast_t
 	tf_ssb_broadcast_t* next;
 	time_t ctime;
 	time_t mtime;
+	time_t expires_at;
 	char host[256];
 	struct sockaddr_in addr;
 	tf_ssb_connection_t* tunnel_connection;
@@ -262,6 +266,7 @@ typedef struct _tf_ssb_t
 	bool is_room;
 	char* room_name;
 	char seeds_host[256];
+	time_t last_seed_check;
 
 	tf_ssb_timer_t** timers;
 	int timers_count;
@@ -357,7 +362,7 @@ static JSClassID _connection_class_id;
 static int s_connection_index;
 static int s_tunnel_index;
 
-static void _tf_ssb_add_broadcast(tf_ssb_t* ssb, const tf_ssb_broadcast_t* broadcast);
+static void _tf_ssb_add_broadcast(tf_ssb_t* ssb, const tf_ssb_broadcast_t* broadcast, int expires_seconds);
 static void _tf_ssb_connection_client_send_hello(tf_ssb_connection_t* connection);
 static void _tf_ssb_connection_close(tf_ssb_connection_t* connection, const char* reason);
 static void _tf_ssb_connection_destroy(tf_ssb_connection_t* connection, const char* reason);
@@ -2946,7 +2951,7 @@ static void _tf_ssb_update_seeds_after_work(tf_ssb_t* ssb, int status, void* use
 		tf_ssb_broadcast_t broadcast = { 0 };
 		if (_tf_ssb_parse_broadcast(seeds->seeds[i], &broadcast))
 		{
-			_tf_ssb_add_broadcast(ssb, &broadcast);
+			_tf_ssb_add_broadcast(ssb, &broadcast, k_seed_expire_seconds);
 		}
 		tf_free(seeds->seeds[i]);
 	}
@@ -2971,11 +2976,12 @@ static void _tf_ssb_broadcast_timer(uv_timer_t* timer)
 		uv_free_interface_addresses(info, count);
 	}
 
-	seeds_t* seeds = tf_malloc(sizeof(seeds_t));
-	*seeds = (seeds_t) { 0 };
-
-	if (*ssb->seeds_host)
+	time_t now = time(NULL);
+	if (*ssb->seeds_host && now - ssb->last_seed_check > k_seed_check_interval_seconds)
 	{
+		seeds_t* seeds = tf_malloc(sizeof(seeds_t));
+		*seeds = (seeds_t) { 0 };
+		ssb->last_seed_check = now;
 		tf_ssb_run_work(ssb, _tf_ssb_update_seeds_work, _tf_ssb_update_seeds_after_work, seeds);
 	}
 }
@@ -3090,7 +3096,7 @@ static void _tf_ssb_notify_broadcasts_changed(tf_ssb_t* ssb)
 	}
 }
 
-static void _tf_ssb_add_broadcast(tf_ssb_t* ssb, const tf_ssb_broadcast_t* broadcast)
+static void _tf_ssb_add_broadcast(tf_ssb_t* ssb, const tf_ssb_broadcast_t* broadcast, int expires_seconds)
 {
 	if (memcmp(broadcast->pub, ssb->pub, sizeof(ssb->pub)) == 0)
 	{
@@ -3104,6 +3110,7 @@ static void _tf_ssb_add_broadcast(tf_ssb_t* ssb, const tf_ssb_broadcast_t* broad
 			if (node->tunnel_connection == broadcast->tunnel_connection && memcmp(node->pub, broadcast->pub, sizeof(node->pub)) == 0)
 			{
 				node->mtime = time(NULL);
+				node->expires_at = node->mtime + expires_seconds;
 				return;
 			}
 		}
@@ -3116,6 +3123,7 @@ static void _tf_ssb_add_broadcast(tf_ssb_t* ssb, const tf_ssb_broadcast_t* broad
 				node->addr.sin_addr.s_addr == broadcast->addr.sin_addr.s_addr && memcmp(node->pub, broadcast->pub, sizeof(node->pub)) == 0)
 			{
 				node->mtime = time(NULL);
+				node->expires_at = node->mtime + expires_seconds;
 				return;
 			}
 		}
@@ -3132,6 +3140,7 @@ static void _tf_ssb_add_broadcast(tf_ssb_t* ssb, const tf_ssb_broadcast_t* broad
 	node->next = ssb->broadcasts;
 	node->ctime = time(NULL);
 	node->mtime = node->ctime;
+	node->expires_at = node->mtime + expires_seconds;
 	ssb->broadcasts = node;
 	ssb->broadcasts_count++;
 
@@ -3157,7 +3166,7 @@ static void _tf_ssb_on_broadcast_listener_recv(uv_udp_t* handle, ssize_t nread,
 		tf_ssb_broadcast_t broadcast = { 0 };
 		if (_tf_ssb_parse_broadcast(entry, &broadcast))
 		{
-			_tf_ssb_add_broadcast(ssb, &broadcast);
+			_tf_ssb_add_broadcast(ssb, &broadcast, k_udp_discovery_expires_seconds);
 		}
 		entry = strtok_r(NULL, k_delim, &state);
 	}
@@ -3188,7 +3197,7 @@ static void _tf_ssb_broadcast_cleanup_timer(uv_timer_t* timer)
 	time_t now = time(NULL);
 	for (tf_ssb_broadcast_t** it = &ssb->broadcasts; *it;)
 	{
-		if (!(*it)->tunnel_connection && (*it)->mtime < now - 10)
+		if (!(*it)->tunnel_connection && now > (*it)->expires_at)
 		{
 			tf_ssb_broadcast_t* node = *it;
 			*it = node->next;
@@ -3604,7 +3613,7 @@ void tf_ssb_connection_add_room_attendant(tf_ssb_connection_t* connection, const
 		.tunnel_connection = connection,
 	};
 	tf_ssb_id_str_to_bin(broadcast.pub, id);
-	_tf_ssb_add_broadcast(connection->ssb, &broadcast);
+	_tf_ssb_add_broadcast(connection->ssb, &broadcast, 0);
 }
 
 void tf_ssb_connection_remove_room_attendant(tf_ssb_connection_t* connection, const char* id)