X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=f666fd980a3d665ce2be0a87372f56347782e9f2;hb=088b5fd9ee6d5f566e8726eae861cbc7cd832b17;hp=456b43d23b1a958848b0a9fb67518d1689d74860;hpb=f3801cb54311da2c30cbe27cd66559a2ea5daa91;p=tinc diff --git a/src/net_packet.c b/src/net_packet.c index 456b43d2..f666fd98 100644 --- a/src/net_packet.c +++ b/src/net_packet.c @@ -52,6 +52,11 @@ #define MAX(a, b) ((a) > (b) ? (a) : (b)) #endif +/* The minimum size of a probe is 14 bytes, but since we normally use CBC mode + encryption, we can add a few extra random bytes without increasing the + resulting packet size. */ +#define MIN_PROBE_SIZE 18 + int keylifetime = 0; #ifdef HAVE_LZO static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS]; @@ -97,20 +102,22 @@ static void udp_probe_timeout_handler(void *data) { 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 UDP probe request %d from %s (%s)", packet->len, n->name, n->hostname); - /* It's a probe request, send back a reply */ + if(!n->status.sptps && !n->status.validkey) { + // But not if we don't have his key. + logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request from %s (%s) but we don't have his key yet", n->name, n->hostname); + return; + } + + logger(DEBUG_TRAFFIC, LOG_INFO, "Got UDP probe request %d from %s (%s)", packet->len, n->name, n->hostname); + /* Type 2 probe replies were introduced in protocol 17.3 */ if ((n->options >> 24) >= 3) { uint8_t *data = DATA(packet); *data++ = 2; uint16_t len16 = htons(len); memcpy(data, &len16, 2); data += 2; - struct timeval now; - gettimeofday(&now, NULL); - uint32_t sec = htonl(now.tv_sec); memcpy(data, &sec, 4); data += 4; - uint32_t usec = htonl(now.tv_usec); memcpy(data, &usec, 4); data += 4; - packet->len = 14; // Minimum size for any probe packet. + packet->len = MIN_PROBE_SIZE; } else { /* Legacy protocol: n won't understand type 2 probe replies. */ DATA(packet)[0] = 1; @@ -160,31 +167,6 @@ static void udp_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { n->minmtu = probelen; try_fix_mtu(n); } - - /* Calculate RTT. - The RTT is the time between the MTU probe burst was sent and the first - reply is received. - */ - - struct timeval now, diff; - gettimeofday(&now, NULL); - timersub(&now, &n->probe_time, &diff); - - struct timeval probe_timestamp = now; - if (DATA(packet)[0] == 2 && packet->len >= 11) { - uint32_t sec; memcpy(&sec, DATA(packet) + 3, 4); - uint32_t usec; memcpy(&usec, DATA(packet) + 7, 4); - probe_timestamp.tv_sec = ntohl(sec); - probe_timestamp.tv_usec = ntohl(usec); - } - - n->probe_counter++; - - if(n->probe_counter == 1) { - n->rtt = diff.tv_sec + diff.tv_usec * 1e-6; - n->probe_time = probe_timestamp; - logger(DEBUG_TRAFFIC, LOG_DEBUG, "%s (%s) RTT %.2f ms, rx packet loss %.2f %%", n->name, n->hostname, n->rtt * 1e3, n->packetloss * 1e2); - } } } @@ -876,12 +858,12 @@ static void try_udp(node_t* n) { int interval = n->status.udp_confirmed ? udp_discovery_keepalive_interval : udp_discovery_interval; if(ping_tx_elapsed.tv_sec >= interval) { - send_udp_probe_packet(n, MAX(n->minmtu, 16)); + send_udp_probe_packet(n, MIN_PROBE_SIZE); n->udp_ping_sent = now; if(localdiscovery && !n->status.udp_confirmed && n->prevedge) { n->status.send_locally = true; - send_udp_probe_packet(n, 16); + send_udp_probe_packet(n, MIN_PROBE_SIZE); n->status.send_locally = false; } } @@ -989,7 +971,7 @@ static void try_mtu(node_t *n) { mtuprobes == -1: send one >maxmtu probe every pingtimeout */ struct timeval elapsed; - timersub(&now, &n->probe_sent_time, &elapsed); + timersub(&now, &n->mtu_ping_sent, &elapsed); if(n->mtuprobes >= 0) { if(n->mtuprobes != 0 && elapsed.tv_sec == 0 && elapsed.tv_usec < 333333) return; @@ -998,11 +980,14 @@ static void try_mtu(node_t *n) { return; } + n->mtu_ping_sent = now; + try_fix_mtu(n); if(n->mtuprobes < 0) { - /* After the initial discovery, we only send one >maxmtu probe - to detect PMTU increases. */ + /* After the initial discovery, we only send one maxmtu and one + maxmtu+1 probe to detect PMTU increases. */ + send_udp_probe_packet(n, n->maxmtu); if(n->maxmtu + 1 < MTU) send_udp_probe_packet(n, n->maxmtu + 1); } else { @@ -1049,23 +1034,6 @@ static void try_mtu(node_t *n) { if(n->mtuprobes >= 0) n->mtuprobes++; } - - n->probe_counter = 0; - n->probe_sent_time = now; - n->probe_time = now; - - /* Calculate the packet loss of incoming traffic by comparing the rate of - packets received to the rate with which the sequence number has increased. - TODO: this is unrelated to PMTU discovery - it should be moved elsewhere. - */ - - if(n->received > n->prev_received) - n->packetloss = 1.0 - (n->received - n->prev_received) / (float)(n->received_seqno - n->prev_received_seqno); - else - n->packetloss = n->received_seqno <= n->prev_received_seqno; - - n->prev_received_seqno = n->received_seqno; - n->prev_received = n->received; } /* These functions try to establish a tunnel to a node (or its relay) so that @@ -1081,7 +1049,7 @@ static void try_mtu(node_t *n) { idle. */ -static void try_tx_sptps(node_t *n) { +static void try_tx_sptps(node_t *n, bool mtu) { /* If n is a TCP-only neighbor, we'll only use "cleartext" PACKET messages anyway, so there's no need for SPTPS at all. */ @@ -1104,13 +1072,14 @@ static void try_tx_sptps(node_t *n) { /* If we do have a relay, try everything with that one instead. */ if(via != n) - return try_tx_sptps(via); + return try_tx_sptps(via, mtu); try_udp(n); - try_mtu(n); + if(mtu) + try_mtu(n); } -static void try_tx_legacy(node_t *n) { +static void try_tx_legacy(node_t *n, bool mtu) { /* Does he have our key? If not, send one. */ if(!n->status.validkey_in) @@ -1127,7 +1096,15 @@ static void try_tx_legacy(node_t *n) { } try_udp(n); - try_mtu(n); + if(mtu) + try_mtu(n); +} + +void try_tx(node_t *n, bool mtu) { + if(n->status.sptps) + try_tx_sptps(n, mtu); + else + try_tx_legacy(n, mtu); } void send_packet(node_t *n, vpn_packet_t *packet) { @@ -1160,7 +1137,7 @@ void send_packet(node_t *n, vpn_packet_t *packet) { if(n->status.sptps) { send_sptps_packet(n, packet); - try_tx_sptps(n); + try_tx_sptps(n, true); return; } @@ -1180,7 +1157,7 @@ void send_packet(node_t *n, vpn_packet_t *packet) { } send_udppacket(via, packet); - try_tx_legacy(via); + try_tx_legacy(via, true); } void broadcast_packet(const node_t *from, vpn_packet_t *packet) {