X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=c2552619857c89f7f53df2a7d7c6a82f27ff6dea;hb=9b9230a0a79c670b86f54fadd2807b864ff9d91f;hp=1e455434be6f48382bbe776bf46734f388027c71;hpb=61275547cdf950e1c4499f19044ff171a9a74af7;p=tinc diff --git a/src/net_packet.c b/src/net_packet.c index 1e455434..c2552619 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; @@ -199,6 +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 @@ -308,10 +318,10 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt) { if(n->status.sptps) return sptps_verify_datagram(&n->sptps, (char *)&inpkt->seqno, inpkt->len); - if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) + if(!digest_active(n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest)) return false; - return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength); + return digest_verify(n->indigest, &inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest)); } static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { @@ -326,7 +336,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { return; } - if(!cipher_active(&n->incipher)) { + if(!cipher_active(n->incipher)) { logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname); return; @@ -334,7 +344,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { /* Check packet length */ - if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) { + if(inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest)) { logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)", n->name, n->hostname); return; @@ -342,20 +352,20 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { /* Check the message authentication code */ - if(digest_active(&n->indigest)) { - inpkt->len -= n->indigest.maclength; - if(!digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) { + if(digest_active(n->indigest)) { + inpkt->len -= digest_length(n->indigest); + if(!digest_verify(n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) { logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname); return; } } /* Decrypt the packet */ - if(cipher_active(&n->incipher)) { + if(cipher_active(n->incipher)) { outpkt = pkt[nextpkt++]; outlen = MAXSIZE; - if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) { + if(!cipher_decrypt(n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) { logger(DEBUG_TRAFFIC, LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname); return; } @@ -433,6 +443,9 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { void receive_tcppacket(connection_t *c, const char *buffer, int len) { vpn_packet_t outpkt; + if(len > sizeof outpkt.data) + return; + outpkt.len = len; if(c->options & OPTION_TCPONLY) outpkt.priority = 0; @@ -448,7 +461,7 @@ 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; @@ -640,11 +653,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { /* Encrypt the packet */ - if(cipher_active(&n->outcipher)) { + if(cipher_active(n->outcipher)) { outpkt = pkt[nextpkt++]; outlen = MAXSIZE; - if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) { + if(!cipher_encrypt(n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) { logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname); goto end; } @@ -655,9 +668,9 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { /* Add the message authentication code */ - if(digest_active(&n->outdigest)) { - digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len); - inpkt->len += digest_length(&n->outdigest); + if(digest_active(n->outdigest)) { + digest_create(n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len); + inpkt->len += digest_length(n->outdigest); } /* Send the packet */