X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=8a4cebd0f2c47543dc33b7653a925365483d4091;hb=4c30004cb6dc23616d7295b0ce631f066e7f1f82;hp=c0be8c4de2f074538041c03d89639025403e0927;hpb=eef25266cb862b5e2c24450d158d99e3cb43e511;p=tinc diff --git a/src/net_packet.c b/src/net_packet.c index c0be8c4d..8a4cebd0 100644 --- a/src/net_packet.c +++ b/src/net_packet.c @@ -1,7 +1,7 @@ /* net_packet.c -- Handles in- and outgoing VPN packets Copyright (C) 1998-2005 Ivo Timmermans, - 2000-2012 Guus Sliepen + 2000-2013 Guus Sliepen 2010 Timothy Redaelli 2010 Brandon Black @@ -22,12 +22,6 @@ #include "system.h" -#include -#include -#include -#include -#include - #ifdef HAVE_ZLIB #include #endif @@ -70,11 +64,15 @@ bool localdiscovery = false; 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. + Probes are sent in batches of at least three, with random sizes between the + lower and upper boundaries for the MTU thus far discovered. + + 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. - In case local discovery is enabled, a fourth packet is added to each batch, + In case local discovery is enabled, another packet is added to each batch, which will be broadcast to the local network. + */ static void send_mtu_probe_handler(void *data) { @@ -125,13 +123,18 @@ static void send_mtu_probe_handler(void *data) { timeout = pingtimeout; } - for(int i = 0; i < 3 + localdiscovery; i++) { + for(int i = 0; i < 4 + localdiscovery; i++) { int len; - if(n->maxmtu <= n->minmtu) + if(i == 0) { + if(n->mtuprobes < 30 || n->maxmtu + 8 >= MTU) + continue; + len = n->maxmtu + 8; + } else if(n->maxmtu <= n->minmtu) { len = n->maxmtu; - else + } else { len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu); + } if(len < 64) len = 64; @@ -140,7 +143,7 @@ static void send_mtu_probe_handler(void *data) { memset(packet.data, 0, 14); randomize(packet.data + 14, len - 14); packet.len = len; - if(i >= 3 && n->mtuprobes <= 10) + if(i >= 4 && n->mtuprobes <= 10) packet.priority = -1; else packet.priority = 0; @@ -150,6 +153,21 @@ static void send_mtu_probe_handler(void *data) { send_udppacket(n, &packet); } + n->probe_counter = 0; + gettimeofday(&n->probe_time, NULL); + + /* Calculate the packet loss of incoming traffic by comparing the rate of + packets received to the rate with which the sequence number has increased. + */ + + 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; + end: timeout_set(&n->mtutimeout, &(struct timeval){timeout, rand() % 100000}); } @@ -184,6 +202,13 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { /* If we haven't established the PMTU yet, restart the discovery process. */ if(n->mtuprobes > 30) { + if (len == n->maxmtu + 8) { + logger(DEBUG_TRAFFIC, LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname); + n->maxmtu = MTU; + n->mtuprobes = 10; + return; + } + if(n->minmtu) n->mtuprobes = 30; else @@ -196,6 +221,25 @@ static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { len = n->maxmtu; if(n->minmtu < len) n->minmtu = len; + + /* Calculate RTT and bandwidth. + The RTT is the time between the MTU probe burst was sent and the first + reply is received. The bandwidth is measured using the time between the + arrival of the first and third probe reply. + */ + + struct timeval now, diff; + gettimeofday(&now, NULL); + timersub(&now, &n->probe_time, &diff); + n->probe_counter++; + + if(n->probe_counter == 1) { + n->rtt = diff.tv_sec + diff.tv_usec * 1e-6; + n->probe_time = now; + } else if(n->probe_counter == 3) { + n->bandwidth = 2.0 * len / (diff.tv_sec + diff.tv_usec * 1e-6); + logger(DEBUG_TRAFFIC, LOG_DEBUG, "%s (%s) RTT %.2f ms, burst bandwidth %.3f Mbit/s, rx packet loss %.2f %%", n->name, n->hostname, n->rtt * 1e3, n->bandwidth * 8e-6, n->packetloss * 1e2); + } } } @@ -414,7 +458,7 @@ static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) { logger(DEBUG_TRAFFIC, LOG_INFO, "No valid key known yet for %s (%s)", n->name, n->hostname); if(!n->status.waitingforkey) send_req_key(n); - else if(n->last_req_key + 10 < time(NULL)) { + else if(n->last_req_key + 10 < now.tv_sec) { logger(DEBUG_ALWAYS, LOG_DEBUG, "No key from %s after 10 seconds, restarting SPTPS", n->name); sptps_stop(&n->sptps); n->status.waitingforkey = false;