X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=a985390ca905ddbe70e737e94c97510b0208c1e1;hp=7a73ef58b7937b8de95336f4332c2a8c0b9e5eba;hb=6834b882015a9323672e9fce8811aa4283f196f0;hpb=92b8abc921dd15b710f67335562210eb713fbb39

diff --git a/src/net_packet.c b/src/net_packet.c
index 7a73ef58..a985390c 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -1,7 +1,9 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2010 Guus Sliepen <guus@tinc-vpn.org>
+                  2010      Timothy Redaelli <timothy@redaelli.eu>
+                  2010      Brandon Black <blblack@gmail.com>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -26,15 +28,22 @@
 #include <openssl/pem.h>
 #include <openssl/hmac.h>
 
+#ifdef HAVE_ZLIB
 #include <zlib.h>
+#endif
+
+#ifdef HAVE_LZO
 #include LZO1X_H
+#endif
 
-#include "avl_tree.h"
+#include "splay_tree.h"
+#include "cipher.h"
 #include "conf.h"
 #include "connection.h"
+#include "crypto.h"
+#include "digest.h"
 #include "device.h"
 #include "ethernet.h"
-#include "event.h"
 #include "graph.h"
 #include "list.h"
 #include "logger.h"
@@ -46,16 +55,16 @@
 #include "utils.h"
 #include "xalloc.h"
 
-#ifdef WSAEMSGSIZE
-#define EMSGSIZE WSAEMSGSIZE
-#endif
-
 int keylifetime = 0;
 int keyexpires = 0;
+#ifdef HAVE_LZO
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
+#endif
 
 static void send_udppacket(node_t *, vpn_packet_t *);
 
+unsigned replaywin = 16;
+
 #define MAX_SEQNO 1073741824
 
 // mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
@@ -63,16 +72,16 @@ static void send_udppacket(node_t *, vpn_packet_t *);
 // mtuprobes ==    32: send 1 burst, sleep pingtimeout second
 // mtuprobes ==    33: no response from other side, restart PMTU discovery process
 
-void send_mtu_probe(node_t *n) {
+static void send_mtu_probe_handler(void *data) {
+	node_t *n = data;
 	vpn_packet_t packet;
 	int len, i;
 	int timeout = 1;
 	
 	n->mtuprobes++;
-	n->mtuevent = NULL;
 
 	if(!n->status.reachable || !n->status.validkey) {
-		logger(LOG_DEBUG, "Trying to send MTU probe to unreachable node %s (%s)", n->name, n->hostname);
+		ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
 		n->mtuprobes = 0;
 		return;
 	}
@@ -91,6 +100,10 @@ void send_mtu_probe(node_t *n) {
 	}
 
 	if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
+		if(n->minmtu > n->maxmtu)
+			n->minmtu = n->maxmtu;
+		else
+			n->maxmtu = n->minmtu;
 		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);
 		n->mtuprobes = 31;
@@ -113,7 +126,7 @@ void send_mtu_probe(node_t *n) {
 			len = 64;
 		
 		memset(packet.data, 0, 14);
-		RAND_pseudo_bytes(packet.data + 14, len - 14);
+		randomize(packet.data + 14, len - 14);
 		packet.len = len;
 		packet.priority = 0;
 
@@ -123,11 +136,15 @@ void send_mtu_probe(node_t *n) {
 	}
 
 end:
-	n->mtuevent = new_event();
-	n->mtuevent->handler = (event_handler_t)send_mtu_probe;
-	n->mtuevent->data = n;
-	n->mtuevent->time = now + timeout;
-	event_add(n->mtuevent);
+	n->mtuevent.time = time(NULL) + timeout;
+	event_add(&n->mtuevent);
+}
+
+void send_mtu_probe(node_t *n) {
+	event_del(&n->mtuevent);
+	n->mtuevent.handler = send_mtu_probe_handler;
+	n->mtuevent.data = n;
+	send_mtu_probe_handler(n);
 }
 
 void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
@@ -135,7 +152,7 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 
 	if(!packet->data[0]) {
 		packet->data[0] = 1;
-		send_packet(n, packet);
+		send_udppacket(n, packet);
 	} else {
 		if(len > n->maxmtu)
 			len = n->maxmtu;
@@ -147,40 +164,61 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 }
 
 static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
-	if(level == 10) {
+	if(level == 0) {
+		memcpy(dest, source, len);
+		return len;
+	} else if(level == 10) {
+#ifdef HAVE_LZO
 		lzo_uint lzolen = MAXSIZE;
 		lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem);
 		return lzolen;
+#else
+		return -1;
+#endif
 	} else if(level < 10) {
+#ifdef HAVE_ZLIB
 		unsigned long destlen = MAXSIZE;
 		if(compress2(dest, &destlen, source, len, level) == Z_OK)
 			return destlen;
 		else
+#endif
 			return -1;
 	} else {
+#ifdef HAVE_LZO
 		lzo_uint lzolen = MAXSIZE;
 		lzo1x_999_compress(source, len, dest, &lzolen, lzo_wrkmem);
 		return lzolen;
+#else
+		return -1;
+#endif
 	}
 	
 	return -1;
 }
 
 static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
-	if(level > 9) {
+	if(level == 0) {
+		memcpy(dest, source, len);
+		return len;
+	} else if(level > 9) {
+#ifdef HAVE_LZO
 		lzo_uint lzolen = MAXSIZE;
 		if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK)
 			return lzolen;
 		else
+#endif
 			return -1;
-	} else {
+	}
+#ifdef HAVE_ZLIB
+	else {
 		unsigned long destlen = MAXSIZE;
 		if(uncompress(dest, &destlen, source, len) == Z_OK)
 			return destlen;
 		else
 			return -1;
 	}
-	
+#endif
+
 	return -1;
 }
 
@@ -193,15 +231,11 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
 	route(n, packet);
 }
 
-static bool try_mac(const node_t *n, const vpn_packet_t *inpkt) {
-	unsigned char hmac[EVP_MAX_MD_SIZE];
-
-	if(!n->indigest || !n->inmaclength || !n->inkey || inpkt->len < sizeof inpkt->seqno + n->inmaclength)
+static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
+	if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest))
 		return false;
 
-	HMAC(n->indigest, n->inkey, n->inkeylength, (unsigned char *) &inpkt->seqno, inpkt->len - n->inmaclength, (unsigned char *)hmac, NULL);
-
-	return !memcmp(hmac, (char *) &inpkt->seqno + inpkt->len - n->inmaclength, n->inmaclength);
+	return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength);
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@@ -209,11 +243,10 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 	vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
 	int nextpkt = 0;
 	vpn_packet_t *outpkt = pkt[0];
-	int outlen, outpad;
-	unsigned char hmac[EVP_MAX_MD_SIZE];
+	size_t outlen;
 	int i;
 
-	if(!n->inkey) {
+	if(!cipher_active(&n->incipher)) {
 		ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
 					n->name, n->hostname);
 		return;
@@ -221,7 +254,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
 	/* Check packet length */
 
-	if(inpkt->len < sizeof(inpkt->seqno) + n->inmaclength) {
+	if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) {
 		ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)",
 					n->name, n->hostname);
 		return;
@@ -229,66 +262,65 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
 	/* Check the message authentication code */
 
-	if(n->indigest && n->inmaclength) {
-		inpkt->len -= n->inmaclength;
-		HMAC(n->indigest, n->inkey, n->inkeylength,
-			 (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
-
-		if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, n->inmaclength)) {
-			ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)",
-					   n->name, n->hostname);
+	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)) {
+			ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
 			return;
 		}
 	}
-
 	/* Decrypt the packet */
 
-	if(n->incipher) {
+	if(cipher_active(&n->incipher)) {
 		outpkt = pkt[nextpkt++];
+		outlen = MAXSIZE;
 
-		if(!EVP_DecryptInit_ex(&n->inctx, NULL, NULL, NULL, NULL)
-				|| !EVP_DecryptUpdate(&n->inctx, (unsigned char *) &outpkt->seqno, &outlen,
-					(unsigned char *) &inpkt->seqno, inpkt->len)
-				|| !EVP_DecryptFinal_ex(&n->inctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
-			ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s): %s",
-						n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
+		if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+			ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
 			return;
 		}
 		
-		outpkt->len = outlen + outpad;
+		outpkt->len = outlen;
 		inpkt = outpkt;
 	}
 
 	/* Check the sequence number */
 
-	inpkt->len -= sizeof(inpkt->seqno);
+	inpkt->len -= sizeof inpkt->seqno;
 	inpkt->seqno = ntohl(inpkt->seqno);
 
-	if(inpkt->seqno != n->received_seqno + 1) {
-		if(inpkt->seqno >= n->received_seqno + sizeof(n->late) * 8) {
-			logger(LOG_WARNING, "Lost %d packets from %s (%s)",
-					   inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
-			
-			memset(n->late, 0, sizeof(n->late));
-		} else if (inpkt->seqno <= n->received_seqno) {
-			if((n->received_seqno >= sizeof(n->late) * 8 && inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8) || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
-				logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
-					   n->name, n->hostname, inpkt->seqno, n->received_seqno);
-				return;
+	if(replaywin) {
+		if(inpkt->seqno != n->received_seqno + 1) {
+			if(inpkt->seqno >= n->received_seqno + replaywin * 8) {
+				if(n->farfuture++ < replaywin >> 2) {
+					logger(LOG_WARNING, "Packet from %s (%s) is %d seqs in the future, dropped (%u)",
+						n->name, n->hostname, inpkt->seqno - n->received_seqno - 1, n->farfuture);
+					return;
+				}
+				logger(LOG_WARNING, "Lost %d packets from %s (%s)",
+					   	inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
+				memset(n->late, 0, replaywin);
+			} else if (inpkt->seqno <= n->received_seqno) {
+				if((n->received_seqno >= replaywin * 8 && inpkt->seqno <= n->received_seqno - replaywin * 8) || !(n->late[(inpkt->seqno / 8) % replaywin] & (1 << inpkt->seqno % 8))) {
+					logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
+					   	n->name, n->hostname, inpkt->seqno, n->received_seqno);
+					return;
+				}
+			} else {
+				for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+					n->late[(i / 8) % replaywin] |= 1 << i % 8;
 			}
-		} else {
-			for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
-				n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8;
 		}
+
+		n->farfuture = 0;
+		n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
 	}
-	
-	n->late[(inpkt->seqno / 8) % sizeof(n->late)] &= ~(1 << inpkt->seqno % 8);
 
 	if(inpkt->seqno > n->received_seqno)
 		n->received_seqno = inpkt->seqno;
 			
 	if(n->received_seqno > MAX_SEQNO)
-		keyexpires = 0;
+		regenerate_key();
 
 	/* Decompress the packet */
 
@@ -336,8 +368,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	int nextpkt = 0;
 	vpn_packet_t *outpkt;
 	int origlen;
-	int outlen, outpad;
+	size_t outlen;
+#if defined(SOL_IP) && defined(IP_TOS)
 	static int priority = 0;
+#endif
 	int origpriority;
 	int sock;
 
@@ -349,14 +383,16 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	/* Make sure we have a valid key */
 
 	if(!n->status.validkey) {
+		time_t now = time(NULL);
+
 		ifdebug(TRAFFIC) logger(LOG_INFO,
 				   "No valid key known yet for %s (%s), forwarding via TCP",
 				   n->name, n->hostname);
 
-		if(!n->status.waitingforkey)
+		if(n->last_req_key + 10 < now) {
 			send_req_key(n);
-
-		n->status.waitingforkey = true;
+			n->last_req_key = now;
+		}
 
 		send_tcppacket(n->nexthop->connection, origpkt);
 
@@ -365,10 +401,13 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
 	if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
 		ifdebug(TRAFFIC) logger(LOG_INFO,
-				"Packet for %s (%s) larger than minimum MTU, forwarding via TCP",
-				n->name, n->hostname);
+				"Packet for %s (%s) larger than minimum MTU, forwarding via %s",
+				n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
 
-		send_tcppacket(n->nexthop->connection, origpkt);
+		if(n != n->nexthop)
+			send_packet(n->nexthop, origpkt);
+		else
+			send_tcppacket(n->nexthop->connection, origpkt);
 
 		return;
 	}
@@ -393,32 +432,28 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	/* Add sequence number */
 
 	inpkt->seqno = htonl(++(n->sent_seqno));
-	inpkt->len += sizeof(inpkt->seqno);
+	inpkt->len += sizeof inpkt->seqno;
 
 	/* Encrypt the packet */
 
-	if(n->outcipher) {
+	if(cipher_active(&n->outcipher)) {
 		outpkt = pkt[nextpkt++];
+		outlen = MAXSIZE;
 
-		if(!EVP_EncryptInit_ex(&n->outctx, NULL, NULL, NULL, NULL)
-				|| !EVP_EncryptUpdate(&n->outctx, (unsigned char *) &outpkt->seqno, &outlen,
-					(unsigned char *) &inpkt->seqno, inpkt->len)
-				|| !EVP_EncryptFinal_ex(&n->outctx, (unsigned 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));
+		if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+			ifdebug(TRAFFIC) logger(LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
 			goto end;
 		}
 
-		outpkt->len = outlen + outpad;
+		outpkt->len = outlen;
 		inpkt = outpkt;
 	}
 
 	/* Add the message authentication code */
 
-	if(n->outdigest && n->outmaclength) {
-		HMAC(n->outdigest, n->outkey, n->outkeylength, (unsigned char *) &inpkt->seqno,
-			 inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
-		inpkt->len += n->outmaclength;
+	if(digest_active(&n->outdigest)) {
+		digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
+		inpkt->len += digest_length(&n->outdigest);
 	}
 
 	/* Determine which socket we have to use */
@@ -437,19 +472,19 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	   && listen_socket[sock].sa.sa.sa_family == AF_INET) {
 		priority = origpriority;
 		ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
-		if(setsockopt(listen_socket[sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority)))	/* SO_PRIORITY doesn't seem to work */
+		if(setsockopt(listen_socket[sock].udp, SOL_IP, IP_TOS, &priority, sizeof priority))	/* SO_PRIORITY doesn't seem to work */
 			logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
 	}
 #endif
 
-	if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
-		if(errno == EMSGSIZE) {
+	if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa)) < 0 && !sockwouldblock(sockerrno)) {
+		if(sockmsgsize(sockerrno)) {
 			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));
+			logger(LOG_ERR, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
 	}
 
 end:
@@ -494,7 +529,7 @@ void send_packet(const node_t *n, vpn_packet_t *packet) {
 /* Broadcast a packet using the minimum spanning tree */
 
 void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
-	avl_node_t *node;
+	splay_node_t *node;
 	connection_t *c;
 
 	ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
@@ -518,61 +553,78 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
 }
 
 static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
-	avl_node_t *node;
-	edge_t *e;
-	node_t *n = NULL;
+	splay_node_t *node;
+	node_t *n, *found = NULL;
+	static time_t last_hard_try = 0;
+	time_t now = time(NULL);
 
-	for(node = edge_weight_tree->head; node; node = node->next) {
-		e = node->data;
-
-		if(sockaddrcmp_noport(from, &e->address))
-			continue;
+	if(last_hard_try == now)
+		return NULL;
+	else
+		last_hard_try = now;
 
-		if(!n)
-			n = e->to;
+	for(node = node_tree->head; node; node = node->next) {
+		n = node->data;
 
-		if(!try_mac(e->to, pkt))
+		if(n == myself || !n->status.reachable || !digest_active(&n->indigest))
 			continue;
 
-		n = e->to;
-		break;
+		if(try_mac(n, pkt)) {
+			found = n;
+			break;
+		}
 	}
 
-	return n;
+	return found;
 }
 
-void handle_incoming_vpn_data(int sock) {
+void handle_incoming_vpn_data(void *arg) {
+	listen_socket_t *l = arg;
 	vpn_packet_t pkt;
 	char *hostname;
 	sockaddr_t from;
-	socklen_t fromlen = sizeof(from);
+	socklen_t fromlen = sizeof from;
 	node_t *n;
+	int len;
 
-	pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+	while(true) {
+		len = recvfrom(l->udp, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
 
-	if(pkt.len < 0) {
-		if(errno != EAGAIN && errno != EINTR)
-			logger(LOG_ERR, "Receiving packet failed: %s", strerror(errno));
-		return;
-	}
+		if(len <= 0 || len > MAXSIZE) {
+			logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+			return;
+		}
 
-	sockaddrunmap(&from);		/* Some braindead IPv6 implementations do stupid things. */
+		pkt.len = len;
 
-	n = lookup_node_udp(&from);
+		sockaddrunmap(&from);		/* Some braindead IPv6 implementations do stupid things. */
 
-	if(!n) {
-		n = try_harder(&from, &pkt);
-		if(n)
-			update_node_udp(n, &from);
-		else ifdebug(PROTOCOL) {
-			hostname = sockaddr2hostname(&from);
-			logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
-			free(hostname);
-			return;
+		mutex_lock(&mutex);
+		n = lookup_node_udp(&from);
+
+		if(!n) {
+			n = try_harder(&from, &pkt);
+			if(n)
+				update_node_udp(n, &from);
 		}
-		else
-			return;
+
+		if(n) {
+			receive_udppacket(n, &pkt);
+		} else {
+			ifdebug(PROTOCOL) {
+				hostname = sockaddr2hostname(&from);
+				logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
+				free(hostname);
+			}
+		}
+
+		mutex_unlock(&mutex);
 	}
+}
+
+void handle_device_data(int sock, short events, void *data) {
+	vpn_packet_t packet;
 
-	receive_udppacket(n, &pkt);
+	if(read_packet(&packet))
+		route(myself, &packet);
 }