/*
net_packet.c -- Handles in- and outgoing VPN packets
- Copyright (C) 1998-2003 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 1998-2004 Ivo Timmermans <ivo@tinc-vpn.org>,
+ 2000-2004 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
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: net_packet.c,v 1.1.2.42 2003/10/10 16:24:24 guus Exp $
+ $Id$
*/
#include "system.h"
#include <openssl/rand.h>
+#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/hmac.h>
#include "conf.h"
#include "connection.h"
#include "device.h"
+#include "ethernet.h"
#include "event.h"
#include "graph.h"
#include "list.h"
#include "utils.h"
#include "xalloc.h"
+#ifdef WSAEMSGSIZE
+#define EMSGSIZE WSAEMSGSIZE
+#endif
+
int keylifetime = 0;
int keyexpires = 0;
EVP_CIPHER_CTX packet_ctx;
static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
+static void send_udppacket(node_t *, vpn_packet_t *);
#define MAX_SEQNO 1073741824
+void send_mtu_probe(node_t *n)
+{
+ vpn_packet_t packet;
+ int len, i;
+
+ cp();
+
+ n->mtuprobes++;
+ n->mtuevent = NULL;
+
+ if(n->mtuprobes >= 10 && !n->minmtu) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname);
+ return;
+ }
+
+ 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;
+ }
+
+ len = n->minmtu + 1 + random() % (n->maxmtu - n->minmtu);
+ if(len < 64)
+ len = 64;
+
+ memset(packet.data, 0, 14);
+ RAND_pseudo_bytes(packet.data + 14, len - 14);
+ packet.len = len;
+
+ ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname);
+
+ send_udppacket(n, &packet);
+ }
+
+ n->mtuevent = xmalloc(sizeof(*n->mtuevent));
+ n->mtuevent->handler = (event_handler_t)send_mtu_probe;
+ n->mtuevent->data = n;
+ n->mtuevent->time = now + 1;
+ event_add(n->mtuevent);
+}
+
+void mtu_probe_h(node_t *n, vpn_packet_t *packet) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, _("Got MTU probe length %d from %s (%s)"), packet->len, n->name, n->hostname);
+
+ if(!packet->data[0]) {
+ packet->data[0] = 1;
+ send_packet(n, packet);
+ } else {
+ if(n->minmtu < packet->len)
+ n->minmtu = packet->len;
+ }
+}
+
static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level)
{
if(level == 10) {
ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"),
packet->len, n->name, n->hostname);
- route_incoming(n, packet);
+ route(n, packet);
}
static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
vpn_packet_t *outpkt = pkt[0];
int outlen, outpad;
char hmac[EVP_MAX_MD_SIZE];
- int i, result;
+ int i;
cp();
if(myself->cipher) {
outpkt = pkt[nextpkt++];
- EVP_DecryptInit_ex(&packet_ctx, NULL, NULL, NULL, NULL);
- if(!EVP_DecryptUpdate(&packet_ctx, (char *) &outpkt->seqno, &outlen,
- (char *) &inpkt->seqno, inpkt->len)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Error decrypting packet from %s (%s): %s"),
- n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
- return;
- }
- if(!EVP_DecryptFinal_ex(&packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
+ if(!EVP_DecryptInit_ex(&packet_ctx, NULL, NULL, NULL, NULL)
+ || !EVP_DecryptUpdate(&packet_ctx, (char *) &outpkt->seqno, &outlen,
+ (char *) &inpkt->seqno, inpkt->len)
+ || !EVP_DecryptFinal_ex(&packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Error decrypting packet from %s (%s): %s"),
n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
return;
memset(n->late, 0, sizeof(n->late));
} else if (inpkt->seqno <= n->received_seqno) {
- if(inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8 || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
+ if((n->received_seqno >= sizeof(n->late) * 8 && inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8) || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
logger(LOG_WARNING, _("Got late or replayed packet from %s (%s), seqno %d, last received %d"),
n->name, n->hostname, inpkt->seqno, n->received_seqno);
- } else
- for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
- n->late[(inpkt->seqno / 8) % sizeof(n->late)] |= 1 << i % 8;
+ return;
+ }
+ } else {
+ for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+ n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8;
}
}
- n->received_seqno = inpkt->seqno;
- n->late[(n->received_seqno / 8) % sizeof(n->late)] &= ~(1 << n->received_seqno % 8);
+ n->late[(inpkt->seqno / 8) % sizeof(n->late)] &= ~(1 << inpkt->seqno % 8);
+
+ if(inpkt->seqno > n->received_seqno)
+ n->received_seqno = inpkt->seqno;
if(n->received_seqno > MAX_SEQNO)
keyexpires = 0;
if(n->connection)
n->connection->last_ping_time = now;
- receive_packet(n, inpkt);
+ if(!inpkt->data[12] && !inpkt->data[13])
+ mtu_probe_h(n, inpkt);
+ else
+ receive_packet(n, inpkt);
}
void receive_tcppacket(connection_t *c, char *buffer, int len)
/* Since packet is on the stack of handle_tap_input(), we have to make a copy of it first. */
- copy = xmalloc(sizeof(vpn_packet_t));
- memcpy(copy, inpkt, sizeof(vpn_packet_t));
+ *(copy = xmalloc(sizeof(*copy))) = *inpkt;
list_insert_tail(n->queue, copy);
if(n->cipher) {
outpkt = pkt[nextpkt++];
- EVP_EncryptInit_ex(&n->packet_ctx, NULL, NULL, NULL, NULL);
- if(!EVP_EncryptUpdate(&n->packet_ctx, (char *) &outpkt->seqno, &outlen,
- (char *) &inpkt->seqno, inpkt->len)) {
+ if(!EVP_EncryptInit_ex(&n->packet_ctx, NULL, NULL, NULL, NULL)
+ || !EVP_EncryptUpdate(&n->packet_ctx, (char *) &outpkt->seqno, &outlen,
+ (char *) &inpkt->seqno, inpkt->len)
+ || !EVP_EncryptFinal_ex(&n->packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s): %s"),
n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
- return;
- }
- if(!EVP_EncryptFinal_ex(&n->packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
- ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s): %s"),
- n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
- return;
+ goto end;
}
outpkt->len = outlen + outpad;
#endif
if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) {
- logger(LOG_ERR, _("Error sending packet to %s (%s): %s"), n->name, n->hostname, strerror(errno));
- return;
+ if(errno == EMSGSIZE) {
+ 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));
}
+end:
inpkt->len = origlen;
}
cp();
- ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
- packet->len, n->name, n->hostname);
-
if(n == myself) {
- ifdebug(TRAFFIC) logger(LOG_NOTICE, _("Packet is looping back to us!"));
+ if(overwrite_mac)
+ memcpy(packet->data, mymac.x, ETH_ALEN);
+ write_packet(packet);
return;
}
+ ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
+ packet->len, n->name, n->hostname);
+
if(!n->status.reachable) {
ifdebug(TRAFFIC) logger(LOG_INFO, _("Node %s (%s) is not reachable"),
n->name, n->hostname);