X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=8753bf6511760133efe18455bba73c72513c4676;hp=d64b6bf911d8bd5fbdf744617abe6068eb0252c6;hb=aebc97a77f37ec63fbd36721f9b284c975e54270;hpb=a1ab57e2755df6c1a8fab95a0886fea368200b96

diff --git a/src/net_packet.c b/src/net_packet.c
index d64b6bf9..8753bf65 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: net_packet.c,v 1.1.2.43 2003/10/11 12:16:12 guus Exp $
+    $Id: net_packet.c,v 1.1.2.48 2003/12/24 10:48:14 guus Exp $
 */
 
 #include "system.h"
@@ -47,14 +47,73 @@
 #include "utils.h"
 #include "xalloc.h"
 
+#ifdef WSAEMSGSIZE
+#define EMSGSIZE WSAEMSGSIZE
+#endif
+
 int keylifetime = 0;
 int keyexpires = 0;
 EVP_CIPHER_CTX packet_ctx;
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
 
+static void send_udppacket(node_t *, vpn_packet_t *);
 
 #define MAX_SEQNO 1073741824
 
+void send_mtu_probe(node_t *n)
+{
+	vpn_packet_t packet;
+	int len, i;
+	
+	cp();
+
+	n->mtuprobes++;
+	n->mtuevent = NULL;
+
+	if(n->mtuprobes >= 10 && !n->minmtu) {
+		ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname);
+		return;
+	}
+
+	for(i = 0; i < 3; i++) {
+		if(n->mtuprobes >= 30 || n->minmtu >= n->maxmtu) {
+			n->mtu = n->minmtu;
+			ifdebug(TRAFFIC) logger(LOG_INFO, _("Fixing MTU of %s (%s) to %d after %d probes"), n->name, n->hostname, n->mtu, n->mtuprobes);
+			return;
+		}
+
+		len = n->minmtu + 1 + random() % (n->maxmtu - n->minmtu);
+		if(len < 64)
+			len = 64;
+		
+		memset(packet.data, 0, 14);
+		RAND_pseudo_bytes(packet.data + 14, len - 14);
+		packet.len = len;
+
+		ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname);
+
+		send_udppacket(n, &packet);
+	}
+
+	n->mtuevent = xmalloc(sizeof(*n->mtuevent));
+	n->mtuevent->handler = (event_handler_t)send_mtu_probe;
+	n->mtuevent->data = n;
+	n->mtuevent->time = now + 1;
+	event_add(n->mtuevent);
+}
+
+void mtu_probe_h(node_t *n, vpn_packet_t *packet) {
+	ifdebug(TRAFFIC) logger(LOG_INFO, _("Got MTU probe length %d from %s (%s)"), packet->len, n->name, n->hostname);
+
+	if(!packet->data[0]) {
+		packet->data[0] = 1;
+		send_packet(n, packet);
+	} else {
+		if(n->minmtu < packet->len)
+			n->minmtu = packet->len;
+	}
+}
+
 static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level)
 {
 	if(level == 10) {
@@ -104,7 +163,7 @@ static void receive_packet(node_t *n, vpn_packet_t *packet)
 	ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"),
 			   packet->len, n->name, n->hostname);
 
-	route_incoming(n, packet);
+	route(n, packet);
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
@@ -203,7 +262,10 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
 	if(n->connection)
 		n->connection->last_ping_time = now;
 
-	receive_packet(n, inpkt);
+	if(!inpkt->data[12] && !inpkt->data[13])
+		mtu_probe_h(n, inpkt);
+	else
+		receive_packet(n, inpkt);
 }
 
 void receive_tcppacket(connection_t *c, char *buffer, int len)
@@ -242,8 +304,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
 
 		/* Since packet is on the stack of handle_tap_input(), we have to make a copy of it first. */
 
-		copy = xmalloc(sizeof(vpn_packet_t));
-		memcpy(copy, inpkt, sizeof(vpn_packet_t));
+		*(copy = xmalloc(sizeof(*copy))) = *inpkt;
 
 		list_insert_tail(n->queue, copy);
 
@@ -291,7 +352,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
 				|| !EVP_EncryptFinal_ex(&n->packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
 			ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s): %s"),
 						n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
-			return;
+			goto end;
 		}
 
 		outpkt->len = outlen + outpad;
@@ -328,10 +389,16 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
 #endif
 
 	if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
-		logger(LOG_ERR, _("Error sending packet to %s (%s): %s"), n->name, n->hostname, strerror(errno));
-		return;
+		if(errno == EMSGSIZE) {
+			if(n->maxmtu >= origlen)
+				n->maxmtu = origlen - 1;
+			if(n->mtu >= origlen)
+				n->mtu = origlen - 1;
+		} else
+			logger(LOG_ERR, _("Error sending packet to %s (%s): %s"), n->name, n->hostname, strerror(errno));
 	}
 
+end:
 	inpkt->len = origlen;
 }
 
@@ -344,14 +411,14 @@ void send_packet(const node_t *n, vpn_packet_t *packet)
 
 	cp();
 
-	ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
-			   packet->len, n->name, n->hostname);
-
 	if(n == myself) {
-		ifdebug(TRAFFIC) logger(LOG_NOTICE, _("Packet is looping back to us!"));
+		write_packet(packet);
 		return;
 	}
 
+	ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
+			   packet->len, n->name, n->hostname);
+
 	if(!n->status.reachable) {
 		ifdebug(TRAFFIC) logger(LOG_INFO, _("Node %s (%s) is not reachable"),
 				   n->name, n->hostname);