Merge branch 'master' into 1.1
[tinc] / src / net_packet.c
index 754e669..062e0be 100644 (file)
@@ -1,7 +1,7 @@
 /*
     net_packet.c -- Handles in- and outgoing VPN packets
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2006 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2009 Guus Sliepen <guus@tinc-vpn.org>
 
     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
@@ -49,6 +49,7 @@
 #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];
 
 static void send_udppacket(node_t *, vpn_packet_t *);
@@ -83,6 +84,7 @@ static void send_mtu_probe_handler(int fd, short events, void *data) {
                memset(packet.data, 0, 14);
                randomize(packet.data + 14, len - 14);
                packet.len = len;
+               packet.priority = 0;
 
                ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname);
 
@@ -98,15 +100,15 @@ void send_mtu_probe(node_t *n) {
        send_mtu_probe_handler(0, 0, n);
 }
 
-void mtu_probe_h(node_t *n, vpn_packet_t *packet) {
+void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
        ifdebug(TRAFFIC) logger(LOG_INFO, _("Got MTU probe length %d from %s (%s)"), packet->len, n->name, n->hostname);
 
        if(!packet->data[0]) {
                packet->data[0] = 1;
                send_packet(n, packet);
        } else {
-               if(n->minmtu < packet->len)
-                       n->minmtu = packet->len;
+               if(n->minmtu < len)
+                       n->minmtu = len;
        }
 }
 
@@ -159,7 +161,16 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
        route(n, packet);
 }
 
-static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
+static bool try_mac(node_t *n, const vpn_packet_t *inpkt)
+{
+       if(!digest_active(&n->indigest) || !n->inmaclength || inpkt->len < sizeof inpkt->seqno + n->inmaclength)
+               return false;
+
+       return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len);
+}
+
+static void 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;
@@ -169,9 +180,15 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
        cp();
 
+       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;
+       }
+
        /* Check packet length */
 
-       if(inpkt->len < sizeof inpkt->seqno + digest_length(&myself->digest)) {
+       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;
@@ -179,18 +196,18 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
        /* Check the message authentication code */
 
-       if(digest_active(&myself->digest) && !digest_verify(&myself->digest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len)) {
+       if(digest_active(&n->indigest) && !digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len)) {
                ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), n->name, n->hostname);
                return;
        }
 
        /* Decrypt the packet */
 
-       if(cipher_active(&myself->cipher)) {
+       if(cipher_active(&n->incipher)) {
                outpkt = pkt[nextpkt++];
                outlen = MAXSIZE;
 
-               if(!cipher_decrypt(&myself->cipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+               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;
                }
@@ -232,20 +249,26 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
        /* Decompress the packet */
 
-       if(myself->compression) {
+       length_t origlen = inpkt->len;
+
+       if(n->incompression) {
                outpkt = pkt[nextpkt++];
 
-               if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, myself->compression)) < 0) {
+               if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) {
                        ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while uncompressing packet from %s (%s)"),
                                                 n->name, n->hostname);
                        return;
                }
 
                inpkt = outpkt;
+
+               origlen -= MTU/64 + 20;
        }
 
+       inpkt->priority = 0;
+
        if(!inpkt->data[12] && !inpkt->data[13])
-               mtu_probe_h(n, inpkt);
+               mtu_probe_h(n, inpkt, origlen);
        else
                receive_packet(n, inpkt);
 }
@@ -256,6 +279,10 @@ void receive_tcppacket(connection_t *c, char *buffer, int len) {
        cp();
 
        outpkt.len = len;
+       if(c->options & OPTION_TCPONLY)
+               outpkt.priority = 0;
+       else
+               outpkt.priority = -1;
        memcpy(outpkt.data, buffer, len);
 
        receive_packet(c->node, &outpkt);
@@ -269,7 +296,6 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        vpn_packet_t *outpkt;
        int origlen;
        size_t outlen;
-       vpn_packet_t *copy;
        static int priority = 0;
        int origpriority;
        int sock;
@@ -280,22 +306,25 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        if(!n->status.validkey) {
                ifdebug(TRAFFIC) logger(LOG_INFO,
-                                  _("No valid key known yet for %s (%s), queueing packet"),
+                                  _("No valid key known yet for %s (%s), forwarding via TCP"),
                                   n->name, n->hostname);
 
-               /* Since packet is on the stack of handle_tap_input(), we have to make a copy of it first. */
+               if(!n->status.waitingforkey)
+                       send_req_key(n);
 
-               *(copy = xmalloc(sizeof *copy)) = *inpkt;
+               n->status.waitingforkey = true;
 
-               list_insert_tail(n->queue, copy);
+               send_tcppacket(n->nexthop->connection, origpkt);
 
-               if(n->queue->count > MAXQUEUELENGTH)
-                       list_delete_head(n->queue);
+               return;
+       }
 
-               if(!n->status.waitingforkey)
-                       send_req_key(n->nexthop->connection, myself, n);
+       if(n->options & OPTION_PMTU_DISCOVERY && !n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
+               ifdebug(TRAFFIC) logger(LOG_INFO,
+                               _("No minimum MTU established yet for %s (%s), forwarding via TCP"),
+                               n->name, n->hostname);
 
-               n->status.waitingforkey = true;
+               send_tcppacket(n->nexthop->connection, origpkt);
 
                return;
        }
@@ -305,10 +334,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Compress the packet */
 
-       if(n->compression) {
+       if(n->outcompression) {
                outpkt = pkt[nextpkt++];
 
-               if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->compression)) < 0) {
+               if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) {
                        ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while compressing packet to %s (%s)"),
                                   n->name, n->hostname);
                        return;
@@ -324,11 +353,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Encrypt the packet */
 
-       if(cipher_active(&n->cipher)) {
+       if(cipher_active(&n->outcipher)) {
                outpkt = pkt[nextpkt++];
                outlen = MAXSIZE;
 
-               if(!cipher_encrypt(&n->cipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+               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;
                }
@@ -339,9 +368,9 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
        /* Add the message authentication code */
 
-       if(digest_active(&n->digest)) {
-               digest_create(&n->digest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len);
-               inpkt->len += digest_length(&n->digest);
+       if(digest_active(&n->outdigest)) {
+               digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len);
+               inpkt->len += digest_length(&n->outdigest);
        }
 
        /* Determine which socket we have to use */
@@ -403,13 +432,13 @@ void send_packet(const node_t *n, vpn_packet_t *packet) {
                return;
        }
 
-       via = (n->via == myself) ? n->nexthop : n->via;
+       via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via;
 
        if(via != n)
-               ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet to %s via %s (%s)"),
+               ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending packet to %s via %s (%s)"),
                           n->name, via->name, n->via->hostname);
 
-       if((myself->options | via->options) & OPTION_TCPONLY) {
+       if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) {
                if(!send_tcppacket(via->connection, packet))
                        terminate_connection(via->connection, true);
        } else
@@ -427,9 +456,15 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
        ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
                           packet->len, from->name, from->hostname);
 
-       if(from != myself)
+       if(from != myself) {
                send_packet(myself, packet);
 
+               // In TunnelServer mode, do not forward broadcast packets.
+                // The MST might not be valid and create loops.
+               if(tunnelserver)
+                       return;
+       }
+
        for(node = connection_tree->head; node; node = node->next) {
                c = node->data;
 
@@ -438,21 +473,32 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
        }
 }
 
-void flush_queue(node_t *n) {
-       list_node_t *node, *next;
+static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
+       splay_node_t *node;
+       edge_t *e;
+       node_t *n = NULL;
+
+       for(node = edge_weight_tree->head; node; node = node->next) {
+               e = node->data;
 
-       cp();
+               if(sockaddrcmp_noport(from, &e->address))
+                       continue;
 
-       ifdebug(TRAFFIC) logger(LOG_INFO, _("Flushing queue for %s (%s)"), n->name, n->hostname);
+               if(!n)
+                       n = e->to;
 
-       for(node = n->queue->head; node; node = next) {
-               next = node->next;
-               send_udppacket(n, node->data);
-               list_delete_node(n->queue, node);
+               if(!try_mac(e->to, pkt))
+                       continue;
+
+               n = e->to;
+               break;
        }
+
+       return n;
 }
 
-void handle_incoming_vpn_data(int sock, short events, void *data) {
+void handle_incoming_vpn_data(int sock, short events, void *data)
+{
        vpn_packet_t pkt;
        char *hostname;
        sockaddr_t from;
@@ -473,11 +519,17 @@ void handle_incoming_vpn_data(int sock, short events, void *data) {
        n = lookup_node_udp(&from);
 
        if(!n) {
-               hostname = sockaddr2hostname(&from);
-               logger(LOG_WARNING, _("Received UDP packet from unknown source %s"),
-                          hostname);
-               free(hostname);
-               return;
+               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;
+               }
+               else
+                       return;
        }
 
        receive_udppacket(n, &pkt);