X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=f9907ee7d73aafdd6b6272cfa7c16bdf15eaaa5d;hb=1545909dcb3ac618754486f4ccd4d8f237d64bb7;hp=ce2361cb08cbc4757cd72dd1e5226b2de0ac376f;hpb=0b2361a9399944cd57def87226f2be7f92646aa5;p=tinc

diff --git a/src/net_packet.c b/src/net_packet.c
index ce2361cb..f9907ee7 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -1,7 +1,7 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2017 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2021 Guus Sliepen <guus@tinc-vpn.org>
                   2010      Timothy Redaelli <timothy@redaelli.eu>
                   2010      Brandon Black <blblack@gmail.com>
 
@@ -23,13 +23,21 @@
 #include "system.h"
 
 #ifdef HAVE_ZLIB
+#define ZLIB_CONST
 #include <zlib.h>
+#include <assert.h>
+
 #endif
 
 #ifdef HAVE_LZO
 #include LZO1X_H
 #endif
 
+#ifdef LZ4_H
+#include LZ4_H
+#endif
+
+#include "address_cache.h"
 #include "cipher.h"
 #include "conf.h"
 #include "connection.h"
@@ -39,14 +47,12 @@
 #include "ethernet.h"
 #include "ipv4.h"
 #include "ipv6.h"
-#include "graph.h"
 #include "logger.h"
 #include "net.h"
 #include "netutl.h"
 #include "protocol.h"
 #include "route.h"
 #include "utils.h"
-#include "xalloc.h"
 
 #ifndef MAX
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
@@ -62,6 +68,12 @@ int keylifetime = 0;
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
 #endif
 
+#ifdef HAVE_LZ4_BUILTIN
+static LZ4_stream_t lz4_stream;
+#else
+static void *lz4_state = NULL;
+#endif /* HAVE_LZ4_BUILTIN */
+
 static void send_udppacket(node_t *, vpn_packet_t *);
 
 unsigned replaywin = 32;
@@ -100,6 +112,7 @@ static void udp_probe_timeout_handler(void *data) {
 
 	logger(DEBUG_TRAFFIC, LOG_INFO, "Too much time has elapsed since last UDP ping response from %s (%s), stopping UDP communication", n->name, n->hostname);
 	n->status.udp_confirmed = false;
+	n->udp_ping_rtt = -1;
 	n->maxrecentlen = 0;
 	n->mtuprobes = 0;
 	n->minmtu = 0;
@@ -138,7 +151,8 @@ static void send_udp_probe_reply(node_t *n, vpn_packet_t *packet, length_t len)
 static void udp_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 	if(!DATA(packet)[0]) {
 		logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request %d from %s (%s)", packet->len, n->name, n->hostname);
-		return send_udp_probe_reply(n, packet, len);
+		send_udp_probe_reply(n, packet, len);
+		return;
 	}
 
 	if(DATA(packet)[0] == 2) {
@@ -148,15 +162,31 @@ static void udp_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 		len = ntohs(len16);
 	}
 
-	logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d UDP probe reply %d from %s (%s)", DATA(packet)[0], len, n->name, n->hostname);
+	if(n->status.ping_sent) {  // a probe in flight
+		gettimeofday(&now, NULL);
+		struct timeval rtt;
+		timersub(&now, &n->udp_ping_sent, &rtt);
+		n->udp_ping_rtt = rtt.tv_sec * 1000000 + rtt.tv_usec;
+		n->status.ping_sent = false;
+		logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d UDP probe reply %d from %s (%s) rtt=%d.%03d", DATA(packet)[0], len, n->name, n->hostname, n->udp_ping_rtt / 1000, n->udp_ping_rtt % 1000);
+	} else {
+		logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d UDP probe reply %d from %s (%s)", DATA(packet)[0], len, 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. */
-	n->status.udp_confirmed = true;
+	if(!n->status.udp_confirmed) {
+		n->status.udp_confirmed = true;
+
+		if(!n->address_cache) {
+			n->address_cache = open_address_cache(n);
+		}
+
+		reset_address_cache(n->address_cache, &n->address);
+	}
 
 	// Reset the UDP ping timer.
-	n->udp_ping_sent = now;
 
 	if(udp_discovery) {
 		timeout_del(&n->udp_ping_timeout);
@@ -186,69 +216,157 @@ static void udp_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 == 0) {
-		memcpy(dest, source, len);
-		return len;
-	} else if(level == 10) {
+#ifdef HAVE_LZ4
+static length_t compress_packet_lz4(uint8_t *dest, const uint8_t *source, length_t len) {
+#ifdef HAVE_LZ4_BUILTIN
+	return LZ4_compress_fast_extState(&lz4_stream, (const char *) source, (char *) dest, len, MAXSIZE, 0);
+#else
+
+	/* @FIXME: Put this in a better place, and free() it too. */
+	if(lz4_state == NULL) {
+		lz4_state = malloc(LZ4_sizeofState());
+	}
+
+	if(lz4_state == NULL) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Failed to allocate lz4_state, error: %i", errno);
+		return 0;
+	}
+
+	return LZ4_compress_fast_extState(lz4_state, (const char *) source, (char *) dest, len, MAXSIZE, 0);
+#endif /* HAVE_LZ4_BUILTIN */
+}
+#endif /* HAVE_LZ4 */
+
 #ifdef HAVE_LZO
-		lzo_uint lzolen = MAXSIZE;
-		lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem);
+static length_t compress_packet_lzo(uint8_t *dest, const uint8_t *source, length_t len, int level) {
+	assert(level == 10 || level == 11);
+
+	lzo_uint lzolen = MAXSIZE;
+	int result;
+
+	if(level == 11) {
+		result = lzo1x_999_compress(source, len, dest, &lzolen, lzo_wrkmem);
+	} else { // level == 10
+		result = lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem);
+	}
+
+	if(result == LZO_E_OK) {
 		return lzolen;
-#else
-		return -1;
+	} else {
+		return 0;
+	}
+}
 #endif
-	} else if(level < 10) {
-#ifdef HAVE_ZLIB
-		unsigned long destlen = MAXSIZE;
 
-		if(compress2(dest, &destlen, source, len, level) == Z_OK) {
-			return destlen;
-		} else
+static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
+	switch(level) {
+#ifdef HAVE_LZ4
+
+	case 12:
+		return compress_packet_lz4(dest, source, len);
 #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;
+
+	case 11:
+	case 10:
+		return compress_packet_lzo(dest, source, len, level);
 #endif
+#ifdef HAVE_ZLIB
+
+	case 9:
+	case 8:
+	case 7:
+	case 6:
+	case 5:
+	case 4:
+	case 3:
+	case 2:
+	case 1: {
+		unsigned long dest_len = MAXSIZE;
+
+		if(compress2(dest, (unsigned long *) &dest_len, source, len, level) == Z_OK) {
+			return dest_len;
+		} else {
+			return 0;
+		}
 	}
 
-	return -1;
-}
+#endif
 
-static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
-	if(level == 0) {
+	case 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
+	default:
+		return 0;
+	}
+}
+
+static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
+	switch(level) {
+#ifdef HAVE_LZ4
+
+	case 12:
+		return LZ4_decompress_safe((char *)source, (char *) dest, len, MAXSIZE);
+
 #endif
-			return -1;
+#ifdef HAVE_LZO
+
+	case 11:
+	case 10: {
+		lzo_uint dst_len = MAXSIZE;
+
+		if(lzo1x_decompress_safe(source, len, dest, (lzo_uint *) &dst_len, NULL) == LZO_E_OK) {
+			return dst_len;
+		} else {
+			return 0;
+		}
 	}
 
+#endif
 #ifdef HAVE_ZLIB
-	else {
+
+	case 9:
+	case 8:
+	case 7:
+	case 6:
+	case 5:
+	case 4:
+	case 3:
+	case 2:
+	case 1: {
 		unsigned long destlen = MAXSIZE;
+		static z_stream stream;
+
+		if(stream.next_in) {
+			inflateReset(&stream);
+		} else {
+			inflateInit(&stream);
+		}
+
+		stream.next_in = source;
+		stream.avail_in = len;
+		stream.next_out = dest;
+		stream.avail_out = destlen;
+		stream.total_out = 0;
 
-		if(uncompress(dest, &destlen, source, len) == Z_OK) {
-			return destlen;
+		if(inflate(&stream, Z_FINISH) == Z_STREAM_END) {
+			return stream.total_out;
 		} else {
-			return -1;
+			return 0;
 		}
 	}
 
 #endif
 
-	return -1;
+	case 0:
+		memcpy(dest, source, len);
+		return len;
+
+	default:
+		return 0;
+	}
 }
 
 /* VPN packet I/O */
@@ -272,7 +390,7 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
 	return false;
 #else
 
-	if(!n->status.validkey_in || !digest_active(n->indigest) || inpkt->len < sizeof(seqno_t) + digest_length(n->indigest)) {
+	if(!n->status.validkey_in || !digest_active(n->indigest) || (size_t)inpkt->len < sizeof(seqno_t) + digest_length(n->indigest)) {
 		return false;
 	}
 
@@ -281,13 +399,6 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
 }
 
 static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
-	vpn_packet_t pkt1, pkt2;
-	vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
-	int nextpkt = 0;
-	size_t outlen;
-	pkt1.offset = DEFAULT_PACKET_OFFSET;
-	pkt2.offset = DEFAULT_PACKET_OFFSET;
-
 	if(n->status.sptps) {
 		if(!n->sptps.state) {
 			if(!n->status.waitingforkey) {
@@ -323,6 +434,12 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 #ifdef DISABLE_LEGACY
 	return false;
 #else
+	vpn_packet_t pkt1, pkt2;
+	vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
+	int nextpkt = 0;
+	size_t outlen;
+	pkt1.offset = DEFAULT_PACKET_OFFSET;
+	pkt2.offset = DEFAULT_PACKET_OFFSET;
 
 	if(!n->status.validkey_in) {
 		logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
@@ -331,7 +448,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
 	/* Check packet length */
 
-	if(inpkt->len < sizeof(seqno_t) + digest_length(n->indigest)) {
+	if((size_t)inpkt->len < sizeof(seqno_t) + digest_length(n->indigest)) {
 		logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)",
 		       n->name, n->hostname);
 		return false;
@@ -393,7 +510,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 					return false;
 				}
 			} else {
-				for(int i = n->received_seqno + 1; i < seqno; i++) {
+				for(seqno_t i = n->received_seqno + 1; i < seqno; i++) {
 					n->late[(i / 8) % replaywin] |= 1 << i % 8;
 				}
 			}
@@ -420,7 +537,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 	if(n->incompression) {
 		vpn_packet_t *outpkt = pkt[nextpkt++];
 
-		if((outpkt->len = uncompress_packet(DATA(outpkt), DATA(inpkt), inpkt->len, n->incompression)) < 0) {
+		if(!(outpkt->len = uncompress_packet(DATA(outpkt), DATA(inpkt), inpkt->len, n->incompression))) {
 			logger(DEBUG_TRAFFIC, LOG_ERR, "Error while uncompressing packet from %s (%s)",
 			       n->name, n->hostname);
 			return false;
@@ -428,7 +545,11 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
 		inpkt = outpkt;
 
-		origlen -= MTU / 64 + 20;
+		if(origlen > MTU / 64 + 20) {
+			origlen -= MTU / 64 + 20;
+		} else {
+			origlen = 0;
+		}
 	}
 
 	if(inpkt->len > n->maxrecentlen) {
@@ -447,7 +568,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 #endif
 }
 
-void receive_tcppacket(connection_t *c, const char *buffer, int len) {
+void receive_tcppacket(connection_t *c, const char *buffer, size_t len) {
 	vpn_packet_t outpkt;
 	outpkt.offset = DEFAULT_PACKET_OFFSET;
 
@@ -468,7 +589,7 @@ void receive_tcppacket(connection_t *c, const char *buffer, int len) {
 	receive_packet(c->node, &outpkt);
 }
 
-bool receive_tcppacket_sptps(connection_t *c, const char *data, int len) {
+bool receive_tcppacket_sptps(connection_t *c, const char *data, size_t len) {
 	if(len < sizeof(node_id_t) + sizeof(node_id_t)) {
 		logger(DEBUG_PROTOCOL, LOG_ERR, "Got too short TCP SPTPS packet from %s (%s)", c->name, c->hostname);
 		return false;
@@ -509,7 +630,10 @@ bool receive_tcppacket_sptps(connection_t *c, const char *data, int len) {
 	/* If we're not the final recipient, relay the packet. */
 
 	if(to != myself) {
-		send_sptps_data(to, from, 0, data, len);
+		if(to->status.validkey) {
+			send_sptps_data(to, from, 0, data, len);
+		}
+
 		try_tx(to, true);
 		return true;
 	}
@@ -559,9 +683,9 @@ static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
 
 	if(n->outcompression) {
 		outpkt.offset = 0;
-		int len = compress_packet(DATA(&outpkt) + offset, DATA(origpkt) + offset, origpkt->len - offset, n->outcompression);
+		length_t len = compress_packet(DATA(&outpkt) + offset, DATA(origpkt) + offset, origpkt->len - offset, n->outcompression);
 
-		if(len < 0) {
+		if(!len) {
 			logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)", n->name, n->hostname);
 		} else if(len < origpkt->len - offset) {
 			outpkt.len = len + offset;
@@ -662,6 +786,19 @@ static void choose_local_address(const node_t *n, const sockaddr_t **sa, int *so
 }
 
 static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
+	if(!n->status.reachable) {
+		logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
+		return;
+	}
+
+	if(n->status.sptps) {
+		send_sptps_packet(n, origpkt);
+		return;
+	}
+
+#ifdef DISABLE_LEGACY
+	return;
+#else
 	vpn_packet_t pkt1, pkt2;
 	vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
 	vpn_packet_t *inpkt = origpkt;
@@ -674,18 +811,6 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	pkt1.offset = DEFAULT_PACKET_OFFSET;
 	pkt2.offset = DEFAULT_PACKET_OFFSET;
 
-	if(!n->status.reachable) {
-		logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
-		return;
-	}
-
-	if(n->status.sptps) {
-		return send_sptps_packet(n, origpkt);
-	}
-
-#ifdef DISABLE_LEGACY
-	return;
-#else
 	/* Make sure we have a valid key */
 
 	if(!n->status.validkey) {
@@ -715,7 +840,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	if(n->outcompression) {
 		outpkt = pkt[nextpkt++];
 
-		if((outpkt->len = compress_packet(DATA(outpkt), DATA(inpkt), inpkt->len, n->outcompression)) < 0) {
+		if(!(outpkt->len = compress_packet(DATA(outpkt), DATA(inpkt), inpkt->len, n->outcompression))) {
 			logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)",
 			       n->name, n->hostname);
 			return;
@@ -869,7 +994,7 @@ bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_
 	if(relay_supported) {
 		if(direct) {
 			/* Inform the recipient that this packet was sent directly. */
-			node_id_t nullid = {};
+			node_id_t nullid = {0};
 			memcpy(buf_ptr, &nullid, sizeof(nullid));
 			buf_ptr += sizeof(nullid);
 		} else {
@@ -929,7 +1054,7 @@ bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t
 		if(!from->status.validkey) {
 			from->status.validkey = true;
 			from->status.waitingforkey = false;
-			logger(DEBUG_META, LOG_INFO, "SPTPS key exchange with %s (%s) succesful", from->name, from->hostname);
+			logger(DEBUG_META, LOG_INFO, "SPTPS key exchange with %s (%s) successful", from->name, from->hostname);
 		}
 
 		return true;
@@ -979,7 +1104,7 @@ bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t
 	if(type & PKT_COMPRESSED) {
 		length_t ulen = uncompress_packet(DATA(&inpkt) + offset, (const uint8_t *)data, len, from->incompression);
 
-		if(ulen < 0) {
+		if(!ulen) {
 			return false;
 		} else {
 			inpkt.len = ulen + offset;
@@ -1045,6 +1170,12 @@ static void try_sptps(node_t *n) {
 
 static void send_udp_probe_packet(node_t *n, int len) {
 	vpn_packet_t packet;
+
+	if(len > sizeof(packet.data)) {
+		logger(DEBUG_TRAFFIC, LOG_INFO, "Truncating probe length %d to %s (%s)", len, n->name, n->hostname);
+		len = sizeof(packet.data);
+	}
+
 	packet.offset = DEFAULT_PACKET_OFFSET;
 	memset(DATA(&packet), 0, 14);
 	randomize(DATA(&packet) + 14, len - 14);
@@ -1093,8 +1224,10 @@ static void try_udp(node_t *n) {
 	int interval = n->status.udp_confirmed ? udp_discovery_keepalive_interval : udp_discovery_interval;
 
 	if(ping_tx_elapsed.tv_sec >= interval) {
+		gettimeofday(&now, NULL);
+		n->udp_ping_sent = now; // a probe in flight
+		n->status.ping_sent = true;
 		send_udp_probe_packet(n, MIN_PROBE_SIZE);
-		n->udp_ping_sent = now;
 
 		if(localdiscovery && !n->status.udp_confirmed && n->prevedge) {
 			n->status.send_locally = true;
@@ -1190,9 +1323,8 @@ static length_t choose_initial_maxmtu(node_t *n) {
 	return mtu;
 
 #else
-
+	(void)n;
 	return MTU;
-
 #endif
 }
 
@@ -1286,14 +1418,19 @@ static void try_mtu(node_t *n) {
 			const length_t minmtu = MAX(n->minmtu, 512);
 			const float interval = n->maxmtu - minmtu;
 
-			/* The core of the discovery algorithm is this exponential.
-			   It produces very large probes early in the cycle, and then it very quickly decreases the probe size.
-			   This reflects the fact that in the most difficult cases, we don't get any feedback for probes that
-			   are too large, and therefore we need to concentrate on small offsets so that we can quickly converge
-			   on the precise MTU as we are approaching it.
-			   The last probe of the cycle is always 1 byte in size - this is to make sure we'll get at least one
-			   reply per cycle so that we can make progress. */
-			const length_t offset = powf(interval, multiplier * cycle_position / (probes_per_cycle - 1));
+			length_t offset = 0;
+
+			/* powf can be underflowed if n->maxmtu is less than 512 due to the minmtu MAX bound */
+			if(interval > 0) {
+				/* The core of the discovery algorithm is this exponential.
+				        It produces very large probes early in the cycle, and then it very quickly decreases the probe size.
+				        This reflects the fact that in the most difficult cases, we don't get any feedback for probes that
+				        are too large, and therefore we need to concentrate on small offsets so that we can quickly converge
+				        on the precise MTU as we are approaching it.
+				        The last probe of the cycle is always 1 byte in size - this is to make sure we'll get at least one
+				        reply per cycle so that we can make progress. */
+				offset = powf(interval, multiplier * cycle_position / (probes_per_cycle - 1));
+			}
 
 			length_t maxmtu = n->maxmtu;
 			send_udp_probe_packet(n, minmtu + offset);
@@ -1347,7 +1484,8 @@ static void try_tx_sptps(node_t *n, bool mtu) {
 			return;
 		}
 
-		return try_tx(via, mtu);
+		try_tx(via, mtu);
+		return;
 	}
 
 	/* Otherwise, try to establish UDP connectivity. */
@@ -1569,7 +1707,7 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
 
 static void handle_incoming_vpn_packet(listen_socket_t *ls, vpn_packet_t *pkt, sockaddr_t *addr) {
 	char *hostname;
-	node_id_t nullid = {};
+	node_id_t nullid = {0};
 	node_t *from, *to;
 	bool direct = false;
 
@@ -1588,7 +1726,7 @@ static void handle_incoming_vpn_packet(listen_socket_t *ls, vpn_packet_t *pkt, s
 		pkt->offset = 2 * sizeof(node_id_t);
 		from = lookup_node_id(SRCID(pkt));
 
-		if(from && !memcmp(DSTID(pkt), &nullid, sizeof(nullid)) && from->status.sptps) {
+		if(from && from->status.sptps && !memcmp(DSTID(pkt), &nullid, sizeof(nullid))) {
 			if(sptps_verify_datagram(&from->sptps, DATA(pkt), pkt->len - 2 * sizeof(node_id_t))) {
 				n = from;
 			} else {
@@ -1624,7 +1762,7 @@ skip_harder:
 			pkt->len -= pkt->offset;
 		}
 
-		if(!memcmp(DSTID(pkt), &nullid, sizeof(nullid)) || !relay_enabled) {
+		if(!relay_enabled || !memcmp(DSTID(pkt), &nullid, sizeof(nullid))) {
 			direct = true;
 			from = n;
 			to = myself;
@@ -1686,6 +1824,8 @@ skip_harder:
 }
 
 void handle_incoming_vpn_data(void *data, int flags) {
+	(void)data;
+	(void)flags;
 	listen_socket_t *ls = data;
 
 #ifdef HAVE_RECVMMSG
@@ -1701,14 +1841,14 @@ void handle_incoming_vpn_data(void *data, int flags) {
 
 		iov[i] = (struct iovec) {
 			.iov_base = DATA(&pkt[i]),
-			 .iov_len = MAXSIZE,
+			.iov_len = MAXSIZE,
 		};
 
 		msg[i].msg_hdr = (struct msghdr) {
 			.msg_name = &addr[i].sa,
-			 .msg_namelen = sizeof(addr)[i],
-			  .msg_iov = &iov[i],
-			   .msg_iovlen = 1,
+			.msg_namelen = sizeof(addr)[i],
+			.msg_iov = &iov[i],
+			.msg_iovlen = 1,
 		};
 	}
 
@@ -1734,13 +1874,13 @@ void handle_incoming_vpn_data(void *data, int flags) {
 
 #else
 	vpn_packet_t pkt;
-	sockaddr_t addr = {};
+	sockaddr_t addr = {0};
 	socklen_t addrlen = sizeof(addr);
 
 	pkt.offset = 0;
 	int len = recvfrom(ls->udp.fd, (void *)DATA(&pkt), MAXSIZE, 0, &addr.sa, &addrlen);
 
-	if(len <= 0 || len > MAXSIZE) {
+	if(len <= 0 || (size_t)len > MAXSIZE) {
 		if(!sockwouldblock(sockerrno)) {
 			logger(DEBUG_ALWAYS, LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
 		}
@@ -1755,6 +1895,8 @@ void handle_incoming_vpn_data(void *data, int flags) {
 }
 
 void handle_device_data(void *data, int flags) {
+	(void)data;
+	(void)flags;
 	vpn_packet_t packet;
 	packet.offset = DEFAULT_PACKET_OFFSET;
 	packet.priority = 0;