X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=d700fd6b7502c34fb686e5df5bd473773408240c;hb=e3c763eae89df9a69bb2d611238ef18f78de311f;hp=5fd563258d4a3fa2f05dc8a94f3ce5dffeb4b085;hpb=9c878bf56f81049397a35d3a41aa69749c697fce;p=tinc

diff --git a/src/net_packet.c b/src/net_packet.c
index 5fd56325..d700fd6b 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -56,6 +56,7 @@ static void send_udppacket(node_t *, vpn_packet_t *);
 
 unsigned replaywin = 16;
 bool localdiscovery = false;
+sockaddr_t localdiscovery_address;
 
 #define MAX_SEQNO 1073741824
 
@@ -178,12 +179,20 @@ void send_mtu_probe(node_t *n) {
 }
 
 static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
-	logger(DEBUG_TRAFFIC, LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
-
 	if(!packet->data[0]) {
+		logger(DEBUG_TRAFFIC, LOG_INFO, "Got MTU probe request %d from %s (%s)", packet->len, n->name, n->hostname);
+
 		/* It's a probe request, send back a reply */
 
-		packet->data[0] = 1;
+		/* Type 2 probe replies were introduced in protocol 17.3 */
+		if ((n->options >> 24) == 3) {
+			uint8_t* data = packet->data;
+			*data++ = 2;
+			uint16_t len16 = htons(len); memcpy(data, &len16, 2); data += 2;
+		} else {
+			/* Legacy protocol: n won't understand type 2 probe replies. */
+			packet->data[0] = 1;
+		}
 
 		/* Temporarily set udp_confirmed, so that the reply is sent
 		   back exactly the way it came in. */
@@ -193,6 +202,16 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 		send_udppacket(n, packet);
 		n->status.udp_confirmed = udp_confirmed;
 	} else {
+		length_t probelen = len;
+		if (packet->data[0] == 2) {
+			if (len < 3)
+				logger(DEBUG_TRAFFIC, LOG_WARNING, "Received invalid (too short) MTU probe reply from %s (%s)", n->name, n->hostname);
+			else {
+				uint16_t probelen16; memcpy(&probelen16, packet->data + 1, 2); probelen = ntohs(probelen16);
+			}
+		}
+		logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d MTU probe reply %d from %s (%s)", packet->data[0], probelen, n->name, n->hostname);
+
 		/* It's a valid reply: now we know bidirectional communication
 		   is possible using the address and socket that the reply
 		   packet used. */
@@ -202,7 +221,7 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 		/* If we haven't established the PMTU yet, restart the discovery process. */
 
 		if(n->mtuprobes > 30) {
-			if (len == n->maxmtu + 8) {
+			if (probelen == n->maxmtu + 8) {
 				logger(DEBUG_TRAFFIC, LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname);
 				n->maxmtu = MTU;
 				n->mtuprobes = 10;
@@ -217,10 +236,10 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 
 		/* If applicable, raise the minimum supported MTU */
 
-		if(len > n->maxmtu)
-			len = n->maxmtu;
-		if(n->minmtu < len)
-			n->minmtu = len;
+		if(probelen > n->maxmtu)
+			probelen = n->maxmtu;
+		if(n->minmtu < probelen)
+			n->minmtu = probelen;
 
 		/* Calculate RTT and bandwidth.
 		   The RTT is the time between the MTU probe burst was sent and the first
@@ -237,7 +256,7 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 			n->rtt = diff.tv_sec + diff.tv_usec * 1e-6;
 			n->probe_time = now;
 		} else if(n->probe_counter == 3) {
-			n->bandwidth = 2.0 * len / (diff.tv_sec + diff.tv_usec * 1e-6);
+			n->bandwidth = 2.0 * probelen / (diff.tv_sec + diff.tv_usec * 1e-6);
 			logger(DEBUG_TRAFFIC, LOG_DEBUG, "%s (%s) RTT %.2f ms, burst bandwidth %.3f Mbit/s, rx packet loss %.2f %%", n->name, n->hostname, n->rtt * 1e3, n->bandwidth * 8e-6, n->packetloss * 1e2);
 		}
 	}
@@ -318,10 +337,10 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
 	if(n->status.sptps)
 		return sptps_verify_datagram(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
 
-	if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest))
+	if(!digest_active(n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest))
 		return false;
 
-	return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength);
+	return digest_verify(n->indigest, &inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest));
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@@ -332,19 +351,27 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 	size_t outlen;
 
 	if(n->status.sptps) {
+		if(!n->sptps.state) {
+			if(!n->status.waitingforkey) {
+				logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but we haven't exchanged keys yet", n->name, n->hostname);
+				send_req_key(n);
+			} else {
+				logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
+			}
+			return;
+		}
 		sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
 		return;
 	}
 
-	if(!cipher_active(&n->incipher)) {
-		logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
-					n->name, n->hostname);
+	if(!cipher_active(n->incipher)) {
+		logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
 		return;
 	}
 
 	/* Check packet length */
 
-	if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) {
+	if(inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest)) {
 		logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)",
 					n->name, n->hostname);
 		return;
@@ -352,20 +379,20 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
 	/* Check the message authentication code */
 
-	if(digest_active(&n->indigest)) {
-		inpkt->len -= n->indigest.maclength;
-		if(!digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) {
+	if(digest_active(n->indigest)) {
+		inpkt->len -= digest_length(n->indigest);
+		if(!digest_verify(n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) {
 			logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
 			return;
 		}
 	}
 	/* Decrypt the packet */
 
-	if(cipher_active(&n->incipher)) {
+	if(cipher_active(n->incipher)) {
 		outpkt = pkt[nextpkt++];
 		outlen = MAXSIZE;
 
-		if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+		if(!cipher_decrypt(n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
 			logger(DEBUG_TRAFFIC, LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
 			return;
 		}
@@ -443,6 +470,9 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 void receive_tcppacket(connection_t *c, const char *buffer, int len) {
 	vpn_packet_t outpkt;
 
+	if(len > sizeof outpkt.data)
+		return;
+
 	outpkt.len = len;
 	if(c->options & OPTION_TCPONLY)
 		outpkt.priority = 0;
@@ -458,7 +488,7 @@ static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
 		logger(DEBUG_TRAFFIC, LOG_INFO, "No valid key known yet for %s (%s)", n->name, n->hostname);
 		if(!n->status.waitingforkey)
 			send_req_key(n);
-		else if(n->last_req_key + 10 < time(NULL)) {
+		else if(n->last_req_key + 10 < now.tv_sec) {
 			logger(DEBUG_ALWAYS, LOG_DEBUG, "No key from %s after 10 seconds, restarting SPTPS", n->name);
 			sptps_stop(&n->sptps);
 			n->status.waitingforkey = false;
@@ -569,12 +599,22 @@ static void choose_broadcast_address(const node_t *n, const sockaddr_t **sa, int
 	*sock = rand() % listen_sockets;
 
 	if(listen_socket[*sock].sa.sa.sa_family == AF_INET6) {
-		broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
-		broadcast_ipv6.in6.sin6_scope_id = listen_socket[*sock].sa.in6.sin6_scope_id;
-		*sa = &broadcast_ipv6;
+		if(localdiscovery_address.sa.sa_family == AF_INET6) {
+			localdiscovery_address.in6.sin6_port = n->prevedge->address.in.sin_port;
+			*sa = &localdiscovery_address;
+		} else {
+			broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
+			broadcast_ipv6.in6.sin6_scope_id = listen_socket[*sock].sa.in6.sin6_scope_id;
+			*sa = &broadcast_ipv6;
+		}
 	} else {
-		broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
-		*sa = &broadcast_ipv4;
+		if(localdiscovery_address.sa.sa_family == AF_INET) {
+			localdiscovery_address.in.sin_port = n->prevedge->address.in.sin_port;
+			*sa = &localdiscovery_address;
+		} else {
+			broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
+			*sa = &broadcast_ipv4;
+		}
 	}
 }
 
@@ -650,11 +690,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
 	/* Encrypt the packet */
 
-	if(cipher_active(&n->outcipher)) {
+	if(cipher_active(n->outcipher)) {
 		outpkt = pkt[nextpkt++];
 		outlen = MAXSIZE;
 
-		if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+		if(!cipher_encrypt(n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
 			logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
 			goto end;
 		}
@@ -665,9 +705,13 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
 	/* Add the message authentication code */
 
-	if(digest_active(&n->outdigest)) {
-		digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
-		inpkt->len += digest_length(&n->outdigest);
+	if(digest_active(n->outdigest)) {
+		if(!digest_create(n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len)) {
+			logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
+			goto end;
+		}
+
+		inpkt->len += digest_length(n->outdigest);
 	}
 
 	/* Send the packet */