X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fnet_packet.c;h=aaa0c7206df76877207b3e916cdaa8e7fe97f4e4;hb=108b238915c5f58b3d94ab433dc5d04e064c2b11;hp=63e3592e9411c379b8515b5977a7712032c2a562;hpb=4c85542894f7fca823b119b05e07179deb24229a;p=meshlink

diff --git a/src/net_packet.c b/src/net_packet.c
index 63e3592e..aaa0c720 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -20,21 +20,17 @@
 
 #include "system.h"
 
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#include <openssl/evp.h>
-#include <openssl/pem.h>
-#include <openssl/hmac.h>
-
 #include <zlib.h>
 #include LZO1X_H
 
-#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"
@@ -46,10 +42,6 @@
 #include "utils.h"
 #include "xalloc.h"
 
-#ifdef WSAEMSGSIZE
-#define EMSGSIZE WSAEMSGSIZE
-#endif
-
 int keylifetime = 0;
 int keyexpires = 0;
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
@@ -58,36 +50,66 @@ static void send_udppacket(node_t *, vpn_packet_t *);
 
 #define MAX_SEQNO 1073741824
 
-void send_mtu_probe(node_t *n) {
+// mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
+// mtuprobes ==    31: sleep pinginterval seconds
+// mtuprobes ==    32: send 1 burst, sleep pingtimeout second
+// mtuprobes ==    33: no response from other side, restart PMTU discovery process
+
+static void send_mtu_probe_handler(int fd, short events, 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) {
-		logger(LOG_DEBUG, "Trying to send MTU probe to unreachable node %s (%s)", n->name, n->hostname);
+	if(!n->status.reachable || !n->status.validkey) {
+		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;
 	}
 
+	if(n->mtuprobes > 32) {
+		ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+		n->mtuprobes = 1;
+		n->minmtu = 0;
+		n->maxmtu = MTU;
+	}
+
 	if(n->mtuprobes >= 10 && !n->minmtu) {
 		ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
+		n->mtuprobes = 0;
 		return;
 	}
 
+	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;
+	}
+
+	if(n->mtuprobes == 31) {
+		timeout = pinginterval;
+		goto end;
+	} else if(n->mtuprobes == 32) {
+		timeout = pingtimeout;
+	}
+
 	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;
-		}
+		if(n->maxmtu <= n->minmtu)
+			len = n->maxmtu;
+		else
+			len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
 
-		len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
 		if(len < 64)
 			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;
 
@@ -96,11 +118,14 @@ void send_mtu_probe(node_t *n) {
 		send_udppacket(n, &packet);
 	}
 
-	n->mtuevent = new_event();
-	n->mtuevent->handler = (event_handler_t)send_mtu_probe;
-	n->mtuevent->data = n;
-	n->mtuevent->time = now + 1;
-	event_add(n->mtuevent);
+end:
+	event_add(&n->mtuevent, &(struct timeval){timeout, 0});
+}
+
+void send_mtu_probe(node_t *n) {
+	if(!timeout_initialized(&n->mtuevent))
+		timeout_set(&n->mtuevent, send_mtu_probe_handler, n);
+	send_mtu_probe_handler(0, 0, n);
 }
 
 void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
@@ -108,10 +133,14 @@ 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;
 		if(n->minmtu < len)
 			n->minmtu = len;
+		if(n->mtuprobes > 30)
+			n->mtuprobes = 30;
 	}
 }
 
@@ -162,15 +191,11 @@ 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, (const char *)&inpkt->seqno + inpkt->len);
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@@ -178,11 +203,10 @@ 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;
@@ -190,7 +214,7 @@ 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;
@@ -198,66 +222,56 @@ 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);
-			return;
-		}
+	if(digest_active(&n->indigest) && !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) {
+		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));
+			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))) {
+			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;
 			}
 		} else {
 			for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
-				n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8;
+				n->late[(i / 8) % sizeof n->late] |= 1 << i % 8;
 		}
 	}
 	
-	n->late[(inpkt->seqno / 8) % sizeof(n->late)] &= ~(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 */
 
@@ -279,9 +293,6 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
 	inpkt->priority = 0;
 
-	if(n->connection)
-		n->connection->last_ping_time = now;
-
 	if(!inpkt->data[12] && !inpkt->data[13])
 		mtu_probe_h(n, inpkt, origlen);
 	else
@@ -308,7 +319,7 @@ 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;
 	static int priority = 0;
 	int origpriority;
 	int sock;
@@ -337,10 +348,13 @@ 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;
 	}
@@ -365,32 +379,28 @@ 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 */
@@ -409,19 +419,19 @@ 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:
@@ -466,7 +476,7 @@ 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)",
@@ -490,15 +500,20 @@ 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;
+	splay_node_t *node;
 	edge_t *e;
 	node_t *n = 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(sockaddrcmp_noport(from, &e->address)) {
+			if(last_hard_try == now)
+				continue;
+			last_hard_try = now;
+		}
 
 		if(!n)
 			n = e->to;
@@ -513,18 +528,18 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
 	return n;
 }
 
-void handle_incoming_vpn_data(int sock) {
+void handle_incoming_vpn_data(int sock, short events, void *data) {
 	vpn_packet_t pkt;
 	char *hostname;
 	sockaddr_t from;
-	socklen_t fromlen = sizeof(from);
+	socklen_t fromlen = sizeof from;
 	node_t *n;
 
 	pkt.len = recvfrom(sock, (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));
+		if(!sockwouldblock(sockerrno))
+			logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
 		return;
 	}
 
@@ -548,3 +563,10 @@ void handle_incoming_vpn_data(int sock) {
 
 	receive_udppacket(n, &pkt);
 }
+
+void handle_device_data(int sock, short events, void *data) {
+	vpn_packet_t packet;
+
+	if(read_packet(&packet))
+		route(myself, &packet);
+}