static void send_udppacket(node_t *, vpn_packet_t *);
-unsigned replaywin = 16;
+unsigned replaywin = 32;
bool localdiscovery = true;
bool udp_discovery = true;
int udp_discovery_keepalive_interval = 10;
if(!n->status.validkey_in || !digest_active(n->indigest) || inpkt->len < sizeof(seqno_t) + digest_length(n->indigest))
return false;
- return digest_verify(n->indigest, SEQNO(inpkt), inpkt->len - digest_length(n->indigest), DATA(inpkt) + inpkt->len - digest_length(n->indigest));
+ return digest_verify(n->indigest, inpkt->data, inpkt->len - digest_length(n->indigest), inpkt->data + inpkt->len - digest_length(n->indigest));
#endif
}
}
return false;
}
- inpkt->offset += 2 * sizeof(node_id_t);
n->status.udppacket = true;
- bool result = sptps_receive_data(&n->sptps, DATA(inpkt), inpkt->len - 2 * sizeof(node_id_t));
+ bool result = sptps_receive_data(&n->sptps, DATA(inpkt), inpkt->len);
n->status.udppacket = false;
if(!result) {
- logger(DEBUG_TRAFFIC, LOG_ERR, "Got bad packet from %s (%s)", n->name, n->hostname);
+ /* Uh-oh. It might be that the tunnel is stuck in some corrupted state,
+ so let's restart SPTPS in case that helps. But don't do that too often
+ to prevent storms, and because that would make life a little too easy
+ for external attackers trying to DoS us. */
+ if(n->last_req_key < now.tv_sec - 10) {
+ logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode raw TCP packet from %s (%s), restarting SPTPS", n->name, n->hostname);
+ send_req_key(n);
+ }
return false;
}
return true;
receive_packet(c->node, &outpkt);
}
+bool receive_tcppacket_sptps(connection_t *c, const char *data, int len) {
+ if (len < sizeof(node_id_t) + sizeof(node_id_t)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got too short TCP SPTPS packet from %s (%s)", c->name, c->hostname);
+ return false;
+ }
+
+ node_t *to = lookup_node_id((node_id_t *)data);
+ data += sizeof(node_id_t); len -= sizeof(node_id_t);
+ if(!to) {
+ logger(DEBUG_PROTOCOL, LOG_ERR, "Got TCP SPTPS packet from %s (%s) with unknown destination ID", c->name, c->hostname);
+ return true;
+ }
+
+ node_t *from = lookup_node_id((node_id_t *)data);
+ data += sizeof(node_id_t); len -= sizeof(node_id_t);
+ if(!from) {
+ logger(DEBUG_PROTOCOL, LOG_ERR, "Got TCP SPTPS packet from %s (%s) with unknown source ID", c->name, c->hostname);
+ return true;
+ }
+
+ if(!to->status.reachable) {
+ /* This can happen in the form of a race condition
+ if the node just became unreachable. */
+ logger(DEBUG_TRAFFIC, LOG_WARNING, "Cannot relay TCP packet from %s (%s) because the destination, %s (%s), is unreachable", from->name, from->hostname, to->name, to->hostname);
+ return true;
+ }
+
+ /* Help the sender reach us over UDP.
+ Note that we only do this if we're the destination or the static relay;
+ otherwise every hop would initiate its own UDP info message, resulting in elevated chatter. */
+ if(to->via == myself)
+ send_udp_info(myself, from);
+
+ /* If we're not the final recipient, relay the packet. */
+
+ if(to != myself) {
+ send_sptps_data(to, from, 0, data, len);
+ try_tx(to, true);
+ return true;
+ }
+
+ /* The packet is for us */
+
+ if(!sptps_receive_data(&from->sptps, data, len)) {
+ /* Uh-oh. It might be that the tunnel is stuck in some corrupted state,
+ so let's restart SPTPS in case that helps. But don't do that too often
+ to prevent storms. */
+ if(from->last_req_key < now.tv_sec - 10) {
+ logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode raw TCP packet from %s (%s), restarting SPTPS", from->name, from->hostname);
+ send_req_key(from);
+ }
+ return true;
+ }
+
+ send_mtu_info(myself, from, MTU);
+ return true;
+}
+
static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
if(!n->status.validkey && !n->connection)
return;
#endif
}
-static bool send_sptps_data_priv(node_t *to, node_t *from, int type, const void *data, size_t len) {
+bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_t len) {
node_t *relay = (to->via != myself && (type == PKT_PROBE || (len - SPTPS_DATAGRAM_OVERHEAD) <= to->via->minmtu)) ? to->via : to->nexthop;
bool direct = from == myself && to == relay;
bool relay_supported = (relay->options >> 24) >= 4;
bool tcponly = (myself->options | relay->options) & OPTION_TCPONLY;
- /* Send it via TCP if it is a handshake packet, TCPOnly is in use, this is a relay packet that the other node cannot understand, or this packet is larger than the MTU.
- TODO: When relaying, the original sender does not know the end-to-end PMTU (it only knows the PMTU of the first hop).
- This can lead to scenarios where large packets are sent over UDP to relay, but then relay has no choice but fall back to TCP. */
+ /* Send it via TCP if it is a handshake packet, TCPOnly is in use, this is a relay packet that the other node cannot understand, or this packet is larger than the MTU. */
if(type == SPTPS_HANDSHAKE || tcponly || (!direct && !relay_supported) || (type != PKT_PROBE && (len - SPTPS_DATAGRAM_OVERHEAD) > relay->minmtu)) {
+ if(type != SPTPS_HANDSHAKE && (to->nexthop->connection->options >> 24) >= 7) {
+ char buf[len + sizeof to->id + sizeof from->id]; char* buf_ptr = buf;
+ memcpy(buf_ptr, &to->id, sizeof to->id); buf_ptr += sizeof to->id;
+ memcpy(buf_ptr, &from->id, sizeof from->id); buf_ptr += sizeof from->id;
+ memcpy(buf_ptr, data, len); buf_ptr += len;
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet from %s (%s) to %s (%s) via %s (%s) (TCP)", from->name, from->hostname, to->name, to->hostname, to->nexthop->name, to->nexthop->hostname);
+ return send_sptps_tcppacket(to->nexthop->connection, buf, sizeof buf);
+ }
+
char buf[len * 4 / 3 + 5];
b64encode(data, buf, len);
- /* If no valid key is known yet, send the packets using ANS_KEY requests,
- to ensure we get to learn the reflexive UDP address. */
- if(from == myself && !to->status.validkey) {
+ /* If this is a handshake packet, use ANS_KEY instead of REQ_KEY, for two reasons:
+ - We don't want intermediate nodes to switch to UDP to relay these packets;
+ - ANS_KEY allows us to learn the reflexive UDP address. */
+ if(type == SPTPS_HANDSHAKE) {
to->incompression = myself->incompression;
return send_request(to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, from->name, to->name, buf, to->incompression);
} else {
- return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, from->name, to->name, REQ_SPTPS, buf);
+ return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, from->name, to->name, SPTPS_PACKET, buf);
}
}
choose_local_address(relay, &sa, &sock);
if(!sa)
choose_udp_address(relay, &sa, &sock);
- logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet from %s (%s) to %s (%s) via %s (%s)", from->name, from->hostname, to->name, to->hostname, relay->name, relay->hostname);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet from %s (%s) to %s (%s) via %s (%s) (UDP)", from->name, from->hostname, to->name, to->hostname, relay->name, relay->hostname);
if(sendto(listen_socket[sock].udp.fd, buf, buf_ptr - buf, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
if(sockmsgsize(sockerrno)) {
// Compensate for SPTPS overhead
return true;
}
-bool send_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
- return send_sptps_data_priv(handle, myself, type, data, len);
-}
-
bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t len) {
node_t *from = handle;
node_t *via = (n->via == myself) ? n->nexthop : n->via;
- /* If the static relay doesn't support SPTPS, everything goes via TCP anyway. */
+ /* If we do have a static relay, try everything with that one instead, if it supports relaying. */
- if((via->options >> 24) < 4)
- return;
-
- /* If we do have a static relay, try everything with that one instead. */
-
- if(via != n)
- return try_tx_sptps(via, mtu);
+ if(via != n) {
+ if((via->options >> 24) < 4)
+ return;
+ return try_tx(via, mtu);
+ }
/* Otherwise, try to establish UDP connectivity. */
while we try to establish direct connectivity. */
if(!n->status.udp_confirmed && n != n->nexthop && (n->nexthop->options >> 24) >= 4)
- try_tx_sptps(n->nexthop, mtu);
+ try_tx(n->nexthop, mtu);
}
static void try_tx_legacy(node_t *n, bool mtu) {
}
void try_tx(node_t *n, bool mtu) {
+ if(!n->status.reachable)
+ return;
if(n->status.sptps)
try_tx_sptps(n, mtu);
else
if(n->status.sptps) {
send_sptps_packet(n, packet);
- try_tx_sptps(n, true);
+ try_tx(n, true);
return;
}
}
send_udppacket(via, packet);
- try_tx_legacy(via, true);
+ try_tx(via, true);
}
void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
if(!n->status.reachable || n == myself)
continue;
- if((n->status.sptps && !n->sptps.instate) || !n->status.validkey_in)
+ if(!n->status.validkey_in && !(n->status.sptps && n->sptps.instate))
continue;
bool soft = false;
return;
}
+ pkt.offset = 0;
+
if(n->status.sptps) {
- pkt.offset = 2 * sizeof(node_id_t);
+ bool relay_enabled = (n->options >> 24) >= 4;
+ if (relay_enabled) {
+ pkt.offset = 2 * sizeof(node_id_t);
+ pkt.len -= pkt.offset;
+ }
- if(!memcmp(DSTID(&pkt), &nullid, sizeof nullid)) {
+ if(!memcmp(DSTID(&pkt), &nullid, sizeof nullid) || !relay_enabled) {
direct = true;
from = n;
to = myself;
return;
}
+ if(!to->status.reachable) {
+ /* This can happen in the form of a race condition
+ if the node just became unreachable. */
+ logger(DEBUG_TRAFFIC, LOG_WARNING, "Cannot relay packet from %s (%s) because the destination, %s (%s), is unreachable", from->name, from->hostname, to->name, to->hostname);
+ return;
+ }
+
+ /* The packet is supposed to come from the originator or its static relay
+ (i.e. with no dynamic relays in between).
+ If it did not, "help" the static relay by sending it UDP info.
+ Note that we only do this if we're the destination or the static relay;
+ otherwise every hop would initiate its own UDP info message, resulting in elevated chatter. */
+
+ if(n != from->via && to->via == myself)
+ send_udp_info(myself, from);
+
+ /* If we're not the final recipient, relay the packet. */
+
if(to != myself) {
- send_sptps_data_priv(to, n, 0, DATA(&pkt), pkt.len - 2 * sizeof(node_id_t));
- try_tx_sptps(n, true);
+ send_sptps_data(to, from, 0, DATA(&pkt), pkt.len);
+ try_tx(to, true);
return;
}
} else {
from = n;
}
- pkt.offset = 0;
if(!receive_udppacket(from, &pkt))
return;
n->sock = ls - listen_socket;
if(direct && sockaddrcmp(&addr, &n->address))
update_node_udp(n, &addr);
+
+ /* If the packet went through a relay, help the sender find the appropriate MTU
+ through the relay path. */
+
+ if(!direct)
+ send_mtu_info(myself, n, MTU);
}
void handle_device_data(void *data, int flags) {
projects / tinc / blobdiff