/*
net_packet.c -- Handles in- and outgoing VPN packets
Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2013 Guus Sliepen <guus@tinc-vpn.org>
2010 Timothy Redaelli <timothy@redaelli.eu>
2010 Brandon Black <blblack@gmail.com>
#include "system.h"
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#include <openssl/evp.h>
-#include <openssl/pem.h>
-#include <openssl/hmac.h>
-
#ifdef HAVE_ZLIB
#include <zlib.h>
#endif
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) {
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;
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;
/* 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
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;