X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_socket.c;h=ded9224d48dd720bfd11ccb7e9c6f334da0d8060;hb=54127996ca4156668b6c7df3bb5d8f952dc598ad;hp=0ee365538be3c8248b721d8a70c934b0d85b7b6d;hpb=f9ab8e266b93aa3be772374ef4a8fdb06e376568;p=tinc

diff --git a/src/net_socket.c b/src/net_socket.c
index 0ee36553..ded9224d 100644
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -45,6 +45,7 @@ int maxtimeout = 900;
 int seconds_till_retry = 5;
 int udp_rcvbuf = 0;
 int udp_sndbuf = 0;
+int max_connection_burst = 100;
 
 listen_socket_t listen_socket[MAXSOCKETS];
 int listen_sockets;
@@ -294,7 +295,7 @@ void retry_outgoing(outgoing_t *outgoing) {
 void finish_connecting(connection_t *c) {
 	logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
 
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 	c->status.connecting = false;
 
 	send_id(c);
@@ -508,7 +509,7 @@ begin:
 	c->outdigest = myself->connection->outdigest;
 	c->outmaclength = myself->connection->outmaclength;
 	c->outcompression = myself->connection->outcompression;
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 
 	connection_add(c);
 
@@ -561,6 +562,47 @@ void handle_new_meta_connection(void *data, int flags) {
 
 	sockaddrunmap(&sa);
 
+	// Check if we get many connections from the same host
+
+	static sockaddr_t prev_sa;
+	static time_t prev_time;
+	static int tarpit = -1;
+
+	if(tarpit >= 0) {
+		closesocket(tarpit);
+		tarpit = -1;
+	}
+
+	if(prev_time == now.tv_sec && !sockaddrcmp_noport(&sa, &prev_sa)) {
+		// if so, keep the connection open but ignore it completely.
+		tarpit = fd;
+		return;
+	}
+
+	memcpy(&prev_sa, &sa, sizeof sa);
+	prev_time = now.tv_sec;
+
+	// Check if we get many connections from different hosts
+
+	static int connection_burst;
+	static int connection_burst_time;
+
+	if(now.tv_sec - connection_burst_time > connection_burst)
+		connection_burst = 0;
+	else
+		connection_burst -= now.tv_sec - connection_burst_time;
+
+	connection_burst_time = now.tv_sec;
+	connection_burst++;
+
+	if(connection_burst >= max_connection_burst) {
+		connection_burst = max_connection_burst;
+		tarpit = fd;
+		return;
+	}
+
+	// Accept the new connection
+
 	c = new_connection();
 	c->name = xstrdup("<unknown>");
 	c->outcipher = myself->connection->outcipher;
@@ -571,7 +613,7 @@ void handle_new_meta_connection(void *data, int flags) {
 	c->address = sa;
 	c->hostname = sockaddr2hostname(&sa);
 	c->socket = fd;
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 
 	logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 
@@ -610,7 +652,7 @@ void handle_new_unix_connection(void *data, int flags) {
 	c->address = sa;
 	c->hostname = xstrdup("localhost port unix");
 	c->socket = fd;
-	c->last_ping_time = time(NULL);
+	c->last_ping_time = now.tv_sec;
 
 	logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
 
@@ -674,7 +716,7 @@ void try_outgoing_connections(void) {
 		}
 
 		if(!found) {
-			outgoing_t *outgoing = xmalloc_and_zero(sizeof *outgoing);
+			outgoing_t *outgoing = xzalloc(sizeof *outgoing);
 			outgoing->name = name;
 			list_insert_tail(outgoing_list, outgoing);
 			setup_outgoing_connection(outgoing);