X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=a24a7add6080d1d20dd6b0267fb464fe2ecc5be7;hb=558b19c2432d938afc4a659668bd461ace6ed744;hp=c3e8c6246206ed5226eef5dd0de2d8ba3e68944d;hpb=b90c42a33b78f22b7046da5a5445c712020f30eb;p=tinc

diff --git a/src/net_packet.c b/src/net_packet.c
index c3e8c624..a24a7add 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -348,12 +348,12 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
 
 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);
+		return sptps_verify_datagram(&n->sptps, ((sptps_packet_t *)inpkt)->data, inpkt->len);
 
 	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 - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest));
+	return digest_verify(n->indigest, (const char *)&inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest));
 }
 
 static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@@ -372,7 +372,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 			}
 			return false;
 		}
-		if(!sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len)) {
+		if(!sptps_receive_data(&n->sptps, ((sptps_packet_t *)&inpkt)->data, inpkt->len)) {
 			logger(DEBUG_TRAFFIC, LOG_ERR, "Got bad packet from %s (%s)", n->name, n->hostname);
 			return false;
 		}
@@ -419,9 +419,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 	/* Check the sequence number */
 
 	inpkt->len -= sizeof inpkt->seqno;
-	uint32_t seqno;
-	memcpy(&seqno, inpkt->seqno, sizeof seqno);
-	seqno = ntohl(seqno);
+	uint32_t seqno = ntohl(inpkt->seqno);
 
 	if(replaywin) {
 		if(seqno != n->received_seqno + 1) {
@@ -699,8 +697,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
 	/* Add sequence number */
 
-	uint32_t seqno = htonl(++(n->sent_seqno));
-	memcpy(inpkt->seqno, &seqno, sizeof inpkt->seqno);
+	inpkt->seqno = htonl(++(n->sent_seqno));
 	inpkt->len += sizeof inpkt->seqno;
 
 	/* Encrypt the packet */
@@ -709,7 +706,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 		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;
 		}
@@ -721,7 +718,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	/* Add the message authentication code */
 
 	if(digest_active(n->outdigest)) {
-		if(!digest_create(n->outdigest, inpkt->seqno, inpkt->len, inpkt->seqno + inpkt->len)) {
+		if(!digest_create(n->outdigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len)) {
 			logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
 			goto end;
 		}
@@ -749,7 +746,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	}
 #endif
 
-	if(sendto(listen_socket[sock].udp.fd, inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
+	if(sendto(listen_socket[sock].udp.fd, &inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
 		if(sockmsgsize(sockerrno)) {
 			if(n->maxmtu >= origlen)
 				n->maxmtu = origlen - 1;
@@ -1031,14 +1028,15 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
 void handle_incoming_vpn_data(void *data, int flags) {
 	listen_socket_t *ls = data;
 	vpn_packet_t pkt;
+	sptps_packet_t *spkt = (sptps_packet_t *)&pkt;
 	char *hostname;
-	sockaddr_t from = {{0}};
-	socklen_t fromlen = sizeof from;
-	node_t *n = NULL;
-	node_t *to = myself;
-	int len;
+	node_id_t nullid = {};
+	sockaddr_t addr = {};
+	socklen_t addrlen = sizeof addr;
+	node_t *from, *to;
+	bool direct = false;
 
-	len = recvfrom(ls->udp.fd, &pkt.dstid, MAXSIZE, 0, &from.sa, &fromlen);
+	int len = recvfrom(ls->udp.fd, &pkt.seqno, MAXSIZE, 0, &addr.sa, &addrlen);
 
 	if(len <= 0 || len > MAXSIZE) {
 		if(!sockwouldblock(sockerrno))
@@ -1048,65 +1046,66 @@ void handle_incoming_vpn_data(void *data, int flags) {
 
 	pkt.len = len;
 
-	sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
+	sockaddrunmap(&addr); /* Some braindead IPv6 implementations do stupid things. */
 
-	bool direct = false;
-	if(len >= sizeof pkt.dstid + sizeof pkt.srcid) {
-		n = lookup_node_id(&pkt.srcid);
-		if(n) {
-			node_id_t nullid = {};
-			if(memcmp(&pkt.dstid, &nullid, sizeof nullid) == 0) {
-				/* A zero dstid is used to indicate a direct, non-relayed packet. */
-				direct = true;
-			} else {
-				to = lookup_node_id(&pkt.dstid);
-				if(!to) {
-					logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet presumably sent by %s (%s) but with unknown destination ID", n->name, n->hostname);
-					return;
-				}
-			}
-			pkt.len -= sizeof pkt.dstid + sizeof pkt.srcid;
-		}
-	}
-
-	if(to != myself) {
-		/* We are being asked to relay this packet. */
+	// Try to figure out who sent this packet.
 
-		/* Don't allow random strangers to relay through us. Note that we check for *any* known address since we are not necessarily the first relay. */
-		if (!lookup_node_udp(&from)) {
-			logger(DEBUG_PROTOCOL, LOG_WARNING, "Refusing to relay packet from (presumably) %s (%s) to (presumably) %s (%s) because the packet comes from an unknown address", n->name, n->hostname, to->name, to->hostname);
-			return;
-		}
-
-		send_sptps_data_priv(to, n, 0, pkt.seqno, pkt.len);
-		return;
-	}
+	node_t *n = lookup_node_udp(&addr);
 
 	if(!n) {
-		/* Most likely an old-style packet without node IDs. */
-		direct = true;
-		memmove(pkt.seqno, &pkt.dstid, sizeof pkt - offsetof(vpn_packet_t, seqno));
-		n = lookup_node_udp(&from);
+		// It might be from a 1.1 node, which might have a source ID in the packet.
+		from = lookup_node_id(&spkt->srcid);
+		if(from && !memcmp(&spkt->dstid, &nullid, sizeof nullid) && from->status.sptps) {
+			if(sptps_verify_datagram(&from->sptps, spkt->data, spkt->len - sizeof(spkt->srcid) - sizeof(spkt->dstid)))
+				n = from;
+			else
+				goto skip_harder;
+		}
 	}
 
 	if(!n)
-		n = try_harder(&from, &pkt);
+		n = try_harder(&addr, &pkt);
 
+skip_harder:
 	if(!n) {
 		if(debug_level >= DEBUG_PROTOCOL) {
-			hostname = sockaddr2hostname(&from);
+			hostname = sockaddr2hostname(&addr);
 			logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
 			free(hostname);
 		}
 		return;
 	}
 
-	if(!receive_udppacket(n, &pkt))
+	if(n->status.sptps) {
+		if(memcmp(&spkt->dstid, &nullid, sizeof nullid)) {
+			direct = true;
+			from = n;
+			to = myself;
+		} else {
+			from = lookup_node_id(&spkt->srcid);
+			to = lookup_node_id(&spkt->dstid);
+		}
+		if(!from || !to) {
+			logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from %s (%s) with unknown source and/or destination ID", n->name, n->hostname);
+			return;
+		}
+
+		spkt->len -= sizeof spkt->dstid + sizeof spkt->srcid;
+		if(to != myself) {
+			send_sptps_data_priv(to, n, 0, spkt->data, spkt->len);
+			return;
+		}
+	} else {
+		direct = true;
+		from = n;
+	}
+
+	if(!receive_udppacket(from, &pkt))
 		return;
 
 	n->sock = ls - listen_socket;
-	if(direct && sockaddrcmp(&from, &n->address))
-		update_node_udp(n, &from);
+	if(direct && sockaddrcmp(&addr, &n->address))
+		update_node_udp(n, &addr);
 }
 
 void handle_device_data(void *data, int flags) {