X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=131f52ec3b4b1680193bcb8d08462ab50cd26e1a;hb=7939ee12836bf2ef772f2a6a1e805ee0d64a8e70;hp=51237d200e2666eb9f0532f4ba5c3d27ab6a1a66;hpb=5d6478b9fbb7379fe6017b2b74c0f1ccb3d2501f;p=tinc diff --git a/src/net_packet.c b/src/net_packet.c index 51237d20..131f52ec 100644 --- a/src/net_packet.c +++ b/src/net_packet.c @@ -59,10 +59,13 @@ static void send_udppacket(node_t *, vpn_packet_t *); unsigned replaywin = 16; bool localdiscovery = true; +bool udp_discovery = true; +int udp_discovery_interval = 9; +int udp_discovery_timeout = 30; #define MAX_SEQNO 1073741824 -static void send_mtu_probe_packet(node_t *n, int len) { +static void send_udp_probe_packet(node_t *n, int len) { vpn_packet_t packet; packet.offset = DEFAULT_PACKET_OFFSET; memset(DATA(&packet), 0, 14); @@ -70,7 +73,7 @@ static void send_mtu_probe_packet(node_t *n, int len) { packet.len = len; packet.priority = 0; - logger(DEBUG_TRAFFIC, LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname); + logger(DEBUG_TRAFFIC, LOG_INFO, "Sending UDP probe length %d to %s (%s)", len, n->name, n->hostname); send_udppacket(n, &packet); } @@ -131,7 +134,7 @@ static void send_mtu_probe_handler(void *data) { /* After the initial discovery, a fourth packet is added to each batch with a size larger than the currently known PMTU, to test if the PMTU has increased. */ if (n->mtuprobes >= 30 && n->maxmtu + 8 < MTU) - send_mtu_probe_packet(n, n->maxmtu + 8); + send_udp_probe_packet(n, n->maxmtu + 8); /* Probes are sent in batches of three, with random sizes between the lower and upper boundaries for the MTU thus far discovered. */ @@ -140,14 +143,14 @@ static void send_mtu_probe_handler(void *data) { if(n->minmtu < n->maxmtu) len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu); - send_mtu_probe_packet(n, MAX(len, 64)); + send_udp_probe_packet(n, MAX(len, 64)); } /* In case local discovery is enabled, another packet is added to each batch, which will be broadcast to the local network. */ if(localdiscovery && n->mtuprobes <= 10 && n->prevedge) { n->status.send_locally = true; - send_mtu_probe_packet(n, 16); + send_udp_probe_packet(n, 16); n->status.send_locally = false; } @@ -175,9 +178,21 @@ void send_mtu_probe(node_t *n) { send_mtu_probe_handler(n); } -static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { +static void udp_probe_timeout_handler(void *data) { + node_t *n = data; + if(!n->status.udp_confirmed) + return; + + 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->mtuprobes = 1; + n->minmtu = 0; + n->maxmtu = MTU; +} + +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 MTU probe request %d from %s (%s)", packet->len, n->name, n->hostname); + logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request %d from %s (%s)", packet->len, n->name, n->hostname); /* It's a probe request, send back a reply */ @@ -207,19 +222,23 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { length_t probelen = len; if (DATA(packet)[0] == 2) { if (len < 3) - logger(DEBUG_TRAFFIC, LOG_WARNING, "Received invalid (too short) MTU probe reply from %s (%s)", n->name, n->hostname); + logger(DEBUG_TRAFFIC, LOG_WARNING, "Received invalid (too short) UDP probe reply from %s (%s)", n->name, n->hostname); else { uint16_t probelen16; memcpy(&probelen16, DATA(packet) + 1, 2); probelen = ntohs(probelen16); } } - logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d MTU probe reply %d from %s (%s)", DATA(packet)[0], probelen, n->name, n->hostname); + logger(DEBUG_TRAFFIC, LOG_INFO, "Got type %d UDP probe reply %d from %s (%s)", DATA(packet)[0], probelen, 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(udp_discovery) { + timeout_del(&n->udp_ping_timeout); + timeout_add(&n->udp_ping_timeout, &udp_probe_timeout_handler, n, &(struct timeval){udp_discovery_timeout, 0}); + } + /* If we haven't established the PMTU yet, restart the discovery process. */ if(n->mtuprobes > 30) { @@ -493,7 +512,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) { inpkt->priority = 0; if(!DATA(inpkt)[12] && !DATA(inpkt)[13]) - mtu_probe_h(n, inpkt, origlen); + udp_probe_h(n, inpkt, origlen); else receive_packet(n, inpkt); return true; @@ -860,7 +879,7 @@ bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t if(type == PKT_PROBE) { inpkt.len = len; memcpy(DATA(&inpkt), data, len); - mtu_probe_h(from, &inpkt, len); + udp_probe_h(from, &inpkt, len); return true; } @@ -935,6 +954,24 @@ static void try_sptps(node_t *n) { return; } +// This function tries to establish a UDP tunnel to a node so that packets can be sent. +// If a tunnel is already established, it makes sure it stays up. +// This function makes no guarantees - it is up to the caller to check the node's state to figure out if UDP is usable. +static void try_udp(node_t* n) { + if(!udp_discovery) + return; + + struct timeval now; + gettimeofday(&now, NULL); + struct timeval ping_tx_elapsed; + timersub(&now, &n->udp_ping_sent, &ping_tx_elapsed); + + if(ping_tx_elapsed.tv_sec >= udp_discovery_interval) { + send_udp_probe_packet(n, MAX(n->minmtu, 16)); + n->udp_ping_sent = now; + } +} + // This function tries to establish a tunnel to a node (or its relay) so that packets can be sent (e.g. get SPTPS keys). // If a tunnel is already established, it tries to improve it (e.g. by trying to establish a UDP tunnel instead of TCP). // This function makes no guarantees - it is up to the caller to check the node's state to figure out if TCP and/or UDP is usable. @@ -958,7 +995,8 @@ static void try_tx(node_t *n) { if(!n->status.sptps && !via->status.validkey && via->last_req_key + 10 <= now.tv_sec) { send_req_key(via); via->last_req_key = now.tv_sec; - } + } else if(via == n || !n->status.sptps || (via->options >> 24) >= 4) + try_udp(via); /* If we don't know how to reach "via" yet, then try to reach it through a relay. */ if(n->status.sptps && !via->status.udp_confirmed && via->nexthop != via && (via->nexthop->options >> 24) >= 4)