/*
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) 1998-2005 Ivo Timmermans,
+ 2000-2006 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 1.1.2.44 2003/12/12 19:52:25 guus Exp $
+ $Id$
*/
#include "system.h"
#include <openssl/hmac.h>
#include <zlib.h>
-#include <lzo1x.h>
+#include LZO1X_H
#include "avl_tree.h"
#include "conf.h"
#include "connection.h"
#include "device.h"
-#include "event.h"
+#include "ethernet.h"
#include "graph.h"
#include "list.h"
#include "logger.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
+static void send_mtu_probe_handler(int fd, short events, void *data) {
+ node_t *n = data;
+ vpn_packet_t packet;
+ int len, i;
+
+ cp();
+
+ n->mtuprobes++;
+
+ 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);
+ }
+
+ event_add(&n->mtuevent, &(struct timeval){1, 0});
+}
+
+void send_mtu_probe(node_t *n) {
+ if(!timeout_initialized(&n->mtuevent))
+ timeout_set(&n->mtuevent, send_mtu_probe_handler, n);
+ send_mtu_probe_handler(0, 0, n);
+}
+
+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) {
int nextpkt = 0;
vpn_packet_t *outpkt = pkt[0];
int outlen, outpad;
- char hmac[EVP_MAX_MD_SIZE];
+ unsigned char hmac[EVP_MAX_MD_SIZE];
int i;
cp();
if(myself->digest && myself->maclength) {
inpkt->len -= myself->maclength;
HMAC(myself->digest, myself->key, myself->keylength,
- (char *) &inpkt->seqno, inpkt->len, hmac, NULL);
+ (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, myself->maclength)) {
ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"),
outpkt = pkt[nextpkt++];
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)) {
+ || !EVP_DecryptUpdate(&packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
+ (unsigned char *) &inpkt->seqno, inpkt->len)
+ || !EVP_DecryptFinal_ex(&packet_ctx, (unsigned 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;
+ regenerate_key();
/* Decompress the packet */
inpkt = outpkt;
}
- 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)
receive_packet(c->node, &outpkt);
}
-static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
+static void send_udppacket(node_t *n, vpn_packet_t *origpkt)
{
vpn_packet_t pkt1, pkt2;
vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
+ vpn_packet_t *inpkt = origpkt;
int nextpkt = 0;
vpn_packet_t *outpkt;
int origlen;
outpkt = pkt[nextpkt++];
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)) {
+ || !EVP_EncryptUpdate(&n->packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
+ (unsigned char *) &inpkt->seqno, inpkt->len)
+ || !EVP_EncryptFinal_ex(&n->packet_ctx, (unsigned 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;
/* Add the message authentication code */
if(n->digest && n->maclength) {
- HMAC(n->digest, n->key, n->keylength, (char *) &inpkt->seqno,
- inpkt->len, (char *) &inpkt->seqno + inpkt->len, &outlen);
+ HMAC(n->digest, n->key, n->keylength, (unsigned char *) &inpkt->seqno,
+ inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
inpkt->len += n->maclength;
}
#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));
}
- inpkt->len = origlen;
+end:
+ origpkt->len = origlen;
}
/*
cp();
if(n == myself) {
+ if(overwrite_mac)
+ memcpy(packet->data, mymac.x, ETH_ALEN);
write_packet(packet);
return;
}
ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
packet->len, from->name, from->hostname);
+ if(from != myself)
+ send_packet(myself, packet);
+
for(node = connection_tree->head; node; node = node->next) {
c = node->data;
}
}
-void handle_incoming_vpn_data(int sock)
+void handle_incoming_vpn_data(int sock, short events, void *data)
{
vpn_packet_t pkt;
char *hostname;
receive_udppacket(n, &pkt);
}
+
+void handle_device_data(int sock, short events, void *data)
+{
+ vpn_packet_t packet;
+
+ if(read_packet(&packet))
+ route(myself, &packet);
+}