/*
net_packet.c -- Handles in- and outgoing VPN packets
Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2010 Guus Sliepen <guus@tinc-vpn.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#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
+
+#ifdef HAVE_LZO
#include LZO1X_H
+#endif
#include "splay_tree.h"
#include "cipher.h"
#include "utils.h"
#include "xalloc.h"
-#ifdef WSAEMSGSIZE
-#define EMSGSIZE WSAEMSGSIZE
-#endif
-
int keylifetime = 0;
int keyexpires = 0;
+#ifdef HAVE_LZO
static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
+#endif
static void send_udppacket(node_t *, vpn_packet_t *);
#define MAX_SEQNO 1073741824
+// mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
+// mtuprobes == 31: sleep pinginterval seconds
+// mtuprobes == 32: send 1 burst, sleep pingtimeout second
+// mtuprobes == 33: no response from other side, restart PMTU discovery process
+
static void send_mtu_probe_handler(int fd, short events, void *data) {
node_t *n = data;
vpn_packet_t packet;
int len, i;
+ int timeout = 1;
n->mtuprobes++;
- if(!n->status.reachable) {
- logger(LOG_DEBUG, "Trying to send MTU probe to unreachable node %s (%s)", n->name, n->hostname);
+ if(!n->status.reachable || !n->status.validkey) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname);
+ n->mtuprobes = 0;
return;
}
+ if(n->mtuprobes > 32) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname);
+ n->mtuprobes = 1;
+ n->minmtu = 0;
+ n->maxmtu = MTU;
+ }
+
if(n->mtuprobes >= 10 && !n->minmtu) {
ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname);
+ n->mtuprobes = 0;
return;
}
+ if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
+ if(n->minmtu > n->maxmtu)
+ n->minmtu = n->maxmtu;
+ else
+ n->maxmtu = n->minmtu;
+ n->mtu = n->minmtu;
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
+ n->mtuprobes = 31;
+ }
+
+ if(n->mtuprobes == 31) {
+ timeout = pinginterval;
+ goto end;
+ } else if(n->mtuprobes == 32) {
+ timeout = pingtimeout;
+ }
+
for(i = 0; i < 3; i++) {
- if(n->mtuprobes >= 30 || n->minmtu >= n->maxmtu) {
- n->mtu = n->minmtu;
- ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes);
- return;
- }
+ if(n->maxmtu <= n->minmtu)
+ len = n->maxmtu;
+ else
+ len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
- len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu);
if(len < 64)
len = 64;
send_udppacket(n, &packet);
}
- event_add(&n->mtuevent, &(struct timeval){1, 0});
+end:
+ event_add(&n->mtuevent, &(struct timeval){timeout, 0});
}
void send_mtu_probe(node_t *n) {
if(!packet->data[0]) {
packet->data[0] = 1;
- send_packet(n, packet);
+ send_udppacket(n, packet);
} else {
+ if(len > n->maxmtu)
+ len = n->maxmtu;
if(n->minmtu < len)
n->minmtu = len;
+ if(n->mtuprobes > 30)
+ n->mtuprobes = 30;
}
}
static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
- if(level == 10) {
+ if(level == 0) {
+ memcpy(dest, source, len);
+ return len;
+ } else if(level == 10) {
+#ifdef HAVE_LZO
lzo_uint lzolen = MAXSIZE;
lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem);
return lzolen;
+#else
+ return -1;
+#endif
} else if(level < 10) {
+#ifdef HAVE_ZLIB
unsigned long destlen = MAXSIZE;
if(compress2(dest, &destlen, source, len, level) == Z_OK)
return destlen;
else
+#endif
return -1;
} else {
+#ifdef HAVE_LZO
lzo_uint lzolen = MAXSIZE;
lzo1x_999_compress(source, len, dest, &lzolen, lzo_wrkmem);
return lzolen;
+#else
+ return -1;
+#endif
}
return -1;
}
static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
- if(level > 9) {
+ if(level == 0) {
+ memcpy(dest, source, len);
+ return len;
+ } else if(level > 9) {
+#ifdef HAVE_LZO
lzo_uint lzolen = MAXSIZE;
if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK)
return lzolen;
else
+#endif
return -1;
- } else {
+ }
+#ifdef HAVE_ZLIB
+ else {
unsigned long destlen = MAXSIZE;
if(uncompress(dest, &destlen, source, len) == Z_OK)
return destlen;
else
return -1;
}
-
+#endif
+
return -1;
}
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, (const char *)&inpkt->seqno + inpkt->len);
+ return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength);
}
static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
/* Check the message authentication code */
- if(digest_active(&n->indigest) && !digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
- return;
+ 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)) {
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
+ return;
+ }
}
-
/* Decrypt the packet */
if(cipher_active(&n->incipher)) {
/* Make sure we have a valid key */
if(!n->status.validkey) {
+ time_t now = time(NULL);
+
ifdebug(TRAFFIC) logger(LOG_INFO,
"No valid key known yet for %s (%s), forwarding via TCP",
n->name, n->hostname);
- if(!n->status.waitingforkey)
+ if(n->last_req_key + 10 < now) {
send_req_key(n);
-
- n->status.waitingforkey = true;
+ n->last_req_key = now;
+ }
send_tcppacket(n->nexthop->connection, origpkt);
if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) {
ifdebug(TRAFFIC) logger(LOG_INFO,
- "Packet for %s (%s) larger than minimum MTU, forwarding via TCP",
- n->name, n->hostname);
+ "Packet for %s (%s) larger than minimum MTU, forwarding via %s",
+ n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
- send_tcppacket(n->nexthop->connection, origpkt);
+ if(n != n->nexthop)
+ send_packet(n->nexthop, origpkt);
+ else
+ send_tcppacket(n->nexthop->connection, origpkt);
return;
}
}
#endif
- if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
- if(errno == EMSGSIZE) {
+ if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa)) < 0 && !sockwouldblock(sockerrno)) {
+ if(sockmsgsize(sockerrno)) {
if(n->maxmtu >= origlen)
n->maxmtu = origlen - 1;
if(n->mtu >= origlen)
n->mtu = origlen - 1;
} else
- logger(LOG_ERR, "Error sending packet to %s (%s): %s", n->name, n->hostname, strerror(errno));
+ logger(LOG_ERR, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno));
}
end:
static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
splay_node_t *node;
- edge_t *e;
- node_t *n = NULL;
-
- for(node = edge_weight_tree->head; node; node = node->next) {
- e = node->data;
+ node_t *n, *found = NULL;
+ static time_t last_hard_try = 0;
+ time_t now = time(NULL);
- if(sockaddrcmp_noport(from, &e->address))
- continue;
+ if(last_hard_try == now)
+ return NULL;
+ else
+ last_hard_try = now;
- if(!n)
- n = e->to;
+ for(node = node_tree->head; node; node = node->next) {
+ n = node->data;
- if(!try_mac(e->to, pkt))
+ if(n == myself || !n->status.reachable || !digest_active(&n->indigest))
continue;
- n = e->to;
- break;
+ if(try_mac(n, pkt)) {
+ found = n;
+ break;
+ }
}
- return n;
+ return found;
}
void handle_incoming_vpn_data(int sock, short events, void *data) {
sockaddr_t from;
socklen_t fromlen = sizeof from;
node_t *n;
+ int len;
- pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+ len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
- if(pkt.len < 0) {
- if(errno != EAGAIN && errno != EINTR)
- logger(LOG_ERR, "Receiving packet failed: %s", strerror(errno));
+ if(len <= 0 || len > MAXSIZE) {
+ if(!sockwouldblock(sockerrno))
+ logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno));
return;
}
+ pkt.len = len;
+
sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
n = lookup_node_udp(&from);