/*
net_packet.c -- Handles in- and outgoing VPN packets
Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2011 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
2010 Timothy Redaelli <timothy@redaelli.eu>
2010 Brandon Black <blblack@gmail.com>
static void send_udppacket(node_t *, vpn_packet_t *);
unsigned replaywin = 16;
+bool localdiscovery = false;
#define MAX_SEQNO 1073741824
-// 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
+/* 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
+
+ Probes are sent in batches of three, with random sizes between the lower and
+ upper boundaries for the MTU thus far discovered.
+
+ In case local discovery is enabled, a fourth packet is added to each batch,
+ which will be broadcast to the local network.
+*/
static void send_mtu_probe_handler(int fd, short events, void *data) {
node_t *n = data;
n->mtuprobes++;
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);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
n->mtuprobes = 0;
- event_del(&n->mtuevent);
return;
}
goto end;
}
- ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+ logger(DEBUG_TRAFFIC, 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->mtuprobes < 32 && !n->minmtu) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
n->mtuprobes = 31;
}
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);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
n->mtuprobes = 31;
}
timeout = pingtimeout;
}
- for(i = 0; i < 3; i++) {
+ for(i = 0; i < 3 + localdiscovery; i++) {
if(n->maxmtu <= n->minmtu)
len = n->maxmtu;
else
memset(packet.data, 0, 14);
randomize(packet.data + 14, len - 14);
packet.len = len;
- packet.priority = 0;
+ if(i >= 3 && n->mtuprobes <= 10)
+ packet.priority = -1;
+ else
+ packet.priority = 0;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
send_udppacket(n, &packet);
}
}
static 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);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname);
if(!packet->data[0]) {
packet->data[0] = 1;
/* VPN packet I/O */
static void receive_packet(node_t *n, vpn_packet_t *packet) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
packet->len, n->name, n->hostname);
n->in_packets++;
size_t outlen;
if(!cipher_active(&n->incipher)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
+ logger(DEBUG_TRAFFIC, 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(&n->indigest)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)",
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)",
n->name, n->hostname);
return;
}
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);
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
return;
}
}
outlen = MAXSIZE;
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);
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
return;
}
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)",
+ logger(DEBUG_ALWAYS, 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)",
+ logger(DEBUG_ALWAYS, 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",
+ logger(DEBUG_ALWAYS, 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;
}
outpkt = pkt[nextpkt++];
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)",
+ logger(DEBUG_TRAFFIC, LOG_ERR, "Error while uncompressing packet from %s (%s)",
n->name, n->hostname);
return;
}
static int priority = 0;
int origpriority = origpkt->priority;
#endif
- int sock;
if(!n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
return;
}
if(!n->status.validkey) {
time_t now = time(NULL);
- ifdebug(TRAFFIC) logger(LOG_INFO,
+ logger(DEBUG_TRAFFIC, LOG_INFO,
"No valid key known yet for %s (%s), forwarding via TCP",
n->name, n->hostname);
}
if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
- ifdebug(TRAFFIC) logger(LOG_INFO,
+ logger(DEBUG_TRAFFIC, LOG_INFO,
"Packet for %s (%s) larger than minimum MTU, forwarding via %s",
n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
outpkt = pkt[nextpkt++];
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)",
+ logger(DEBUG_TRAFFIC, LOG_ERR, "Error while compressing packet to %s (%s)",
n->name, n->hostname);
return;
}
outlen = MAXSIZE;
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);
+ logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
goto end;
}
/* Determine which socket we have to use */
- for(sock = 0; sock < listen_sockets; sock++)
- if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family)
- break;
-
- if(sock >= listen_sockets)
- sock = 0; /* If none is available, just use the first and hope for the best. */
+ if(n->address.sa.sa_family != listen_socket[n->sock].sa.sa.sa_family) {
+ for(int sock = 0; sock < listen_sockets; sock++) {
+ if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family) {
+ n->sock = sock;
+ break;
+ }
+ }
+ }
/* Send the packet */
+ struct sockaddr *sa;
+ socklen_t sl;
+ int sock;
+
+ /* Overloaded use of priority field: -1 means local broadcast */
+
+ if(origpriority == -1 && n->prevedge) {
+ struct sockaddr_in in;
+ in.sin_family = AF_INET;
+ in.sin_addr.s_addr = -1;
+ in.sin_port = n->prevedge->address.in.sin_port;
+ sa = (struct sockaddr *)∈
+ sl = sizeof in;
+ sock = 0;
+ } else {
+ if(origpriority == -1)
+ origpriority = 0;
+
+ sa = &(n->address.sa);
+ sl = SALEN(n->address.sa);
+ sock = n->sock;
+ }
+
#if defined(SOL_IP) && defined(IP_TOS)
if(priorityinheritance && origpriority != priority
- && listen_socket[sock].sa.sa.sa_family == AF_INET) {
+ && listen_socket[n->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 */
- logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
+ if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
+ logger(DEBUG_ALWAYS, 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 && !sockwouldblock(sockerrno)) {
+ if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, sa, sl) < 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, sockstrerror(sockerrno));
+ logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
}
end:
memcpy(packet->data, mymac.x, ETH_ALEN);
n->out_packets++;
n->out_bytes += packet->len;
- write_packet(packet);
+ devops.write(packet);
return;
}
- ifdebug(TRAFFIC) logger(LOG_ERR, "Sending packet of %d bytes to %s (%s)",
+ logger(DEBUG_TRAFFIC, LOG_ERR, "Sending packet of %d bytes to %s (%s)",
packet->len, n->name, n->hostname);
if(!n->status.reachable) {
- ifdebug(TRAFFIC) logger(LOG_INFO, "Node %s (%s) is not reachable",
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Node %s (%s) is not reachable",
n->name, n->hostname);
return;
}
via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via;
if(via != n)
- ifdebug(TRAFFIC) logger(LOG_INFO, "Sending packet to %s via %s (%s)",
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet to %s via %s (%s)",
n->name, via->name, n->via->hostname);
if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) {
void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
splay_node_t *node;
connection_t *c;
+ node_t *n;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
+ // Always give ourself a copy of the packet.
+ 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 || broadcast_mode == BMODE_NONE)
+ return;
+
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
packet->len, from->name, from->hostname);
- if(from != myself) {
- send_packet(myself, packet);
+ switch(broadcast_mode) {
+ // In MST mode, broadcast packets travel via the Minimum Spanning Tree.
+ // This guarantees all nodes receive the broadcast packet, and
+ // usually distributes the sending of broadcast packets over all nodes.
+ case BMODE_MST:
+ for(node = connection_tree->head; node; node = node->next) {
+ c = node->data;
- // In TunnelServer mode, do not forward broadcast packets.
- // The MST might not be valid and create loops.
- if(tunnelserver)
- return;
- }
+ if(c->status.active && c->status.mst && c != from->nexthop->connection)
+ send_packet(c->node, packet);
+ }
+ break;
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
+ // In direct mode, we send copies to each node we know of.
+ // However, this only reaches nodes that can be reached in a single hop.
+ // We don't have enough information to forward broadcast packets in this case.
+ case BMODE_DIRECT:
+ if(from != myself)
+ break;
- if(c->status.active && c->status.mst && c != from->nexthop->connection)
- send_packet(c->node, packet);
+ for(node = node_udp_tree->head; node; node = node->next) {
+ n = node->data;
+
+ if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
+ send_packet(n, packet);
+ }
+ break;
+
+ default:
+ break;
}
}
static time_t last_hard_try = 0;
time_t now = time(NULL);
- if(last_hard_try == now)
- return NULL;
- else
- last_hard_try = now;
-
for(node = edge_weight_tree->head; node; node = node->next) {
e = node->data;
if(hard)
last_hard_try = now;
+ last_hard_try = now;
return n;
}
if(len <= 0 || len > MAXSIZE) {
if(!sockwouldblock(sockerrno))
- logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
return;
}
n = try_harder(&from, &pkt);
if(n)
update_node_udp(n, &from);
- else ifdebug(PROTOCOL) {
+ else if(debug_level >= DEBUG_PROTOCOL) {
hostname = sockaddr2hostname(&from);
- logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
+ logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
free(hostname);
return;
}
return;
}
+ n->sock = (intptr_t)data;
+
receive_udppacket(n, &pkt);
}
packet.priority = 0;
- if(read_packet(&packet)) {
+ if(devops.read(&packet)) {
myself->in_packets++;
myself->in_bytes += packet.len;
route(myself, &packet);
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