/*
net_packet.c -- Handles in- and outgoing VPN packets
Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2006 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2009 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
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- $Id$
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "system.h"
#include "utils.h"
#include "xalloc.h"
-#ifdef WSAEMSGSIZE
-#define EMSGSIZE WSAEMSGSIZE
-#endif
-
int keylifetime = 0;
+int keyexpires = 0;
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
+// 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;
- cp();
-
n->mtuprobes++;
+ 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);
+ 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 + random() % (n->maxmtu - n->minmtu);
if(len < 64)
len = 64;
memset(packet.data, 0, 14);
randomize(packet.data + 14, len - 14);
packet.len = len;
+ packet.priority = 0;
- ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname);
+ 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});
+end:
+ event_add(&n->mtuevent, &(struct timeval){timeout, 0});
}
void send_mtu_probe(node_t *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);
+void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
+ 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);
+ send_udppacket(n, packet);
} else {
- if(n->minmtu < packet->len)
- n->minmtu = packet->len;
+ if(len > n->maxmtu)
+ len = n->maxmtu;
+ if(n->minmtu < len)
+ n->minmtu = len;
+ if(n->mtuprobes > 30)
+ n->mtuprobes = 30;
}
}
/* VPN packet I/O */
static void receive_packet(node_t *n, vpn_packet_t *packet) {
- cp();
-
- ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"),
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)",
packet->len, n->name, n->hostname);
route(n, packet);
}
+static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
+ 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);
+}
+
static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
vpn_packet_t pkt1, pkt2;
vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
size_t outlen;
int i;
- cp();
+ if(!cipher_active(&n->incipher)) {
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet",
+ n->name, n->hostname);
+ return;
+ }
/* Check packet length */
- if(inpkt->len < sizeof inpkt->seqno + digest_length(&myself->digest)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got too short packet from %s (%s)"),
+ if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) {
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)",
n->name, n->hostname);
return;
}
/* Check the message authentication code */
- if(digest_active(&myself->digest) && !digest_verify(&myself->digest, &inpkt->seqno, inpkt->len, &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(&myself->cipher)) {
+ if(cipher_active(&n->incipher)) {
outpkt = pkt[nextpkt++];
outlen = MAXSIZE;
- if(!cipher_decrypt(&myself->cipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Error decrypting packet from %s (%s)"), n->name, n->hostname);
+ if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
return;
}
if(inpkt->seqno != n->received_seqno + 1) {
if(inpkt->seqno >= n->received_seqno + sizeof n->late * 8) {
- logger(LOG_WARNING, _("Lost %d packets from %s (%s)"),
+ logger(LOG_WARNING, "Lost %d packets from %s (%s)",
inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
memset(n->late, 0, sizeof n->late);
} else if (inpkt->seqno <= n->received_seqno) {
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"),
+ 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);
return;
}
/* Decompress the packet */
- if(myself->compression) {
+ length_t origlen = inpkt->len;
+
+ if(n->incompression) {
outpkt = pkt[nextpkt++];
- if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, myself->compression)) < 0) {
- ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while uncompressing packet from %s (%s)"),
+ if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) {
+ ifdebug(TRAFFIC) logger(LOG_ERR, "Error while uncompressing packet from %s (%s)",
n->name, n->hostname);
return;
}
inpkt = outpkt;
+
+ origlen -= MTU/64 + 20;
}
+ inpkt->priority = 0;
+
if(!inpkt->data[12] && !inpkt->data[13])
- mtu_probe_h(n, inpkt);
+ mtu_probe_h(n, inpkt, origlen);
else
receive_packet(n, inpkt);
}
void receive_tcppacket(connection_t *c, char *buffer, int len) {
vpn_packet_t outpkt;
- cp();
-
outpkt.len = len;
+ if(c->options & OPTION_TCPONLY)
+ outpkt.priority = 0;
+ else
+ outpkt.priority = -1;
memcpy(outpkt.data, buffer, len);
receive_packet(c->node, &outpkt);
vpn_packet_t *outpkt;
int origlen;
size_t outlen;
- vpn_packet_t *copy;
static int priority = 0;
int origpriority;
int sock;
- cp();
+ if(!n->status.reachable) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
+ return;
+ }
/* Make sure we have a valid key */
if(!n->status.validkey) {
ifdebug(TRAFFIC) logger(LOG_INFO,
- _("No valid key known yet for %s (%s), queueing packet"),
+ "No valid key known yet for %s (%s), forwarding via TCP",
n->name, n->hostname);
- /* Since packet is on the stack of handle_tap_input(), we have to make a copy of it first. */
+ if(!n->status.waitingforkey)
+ send_req_key(n);
- *(copy = xmalloc(sizeof *copy)) = *inpkt;
+ n->status.waitingforkey = true;
- list_insert_tail(n->queue, copy);
+ send_tcppacket(n->nexthop->connection, origpkt);
- if(n->queue->count > MAXQUEUELENGTH)
- list_delete_head(n->queue);
+ return;
+ }
- if(!n->status.waitingforkey)
- send_req_key(n->nexthop->connection, myself, n);
+ 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 %s",
+ n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP");
- n->status.waitingforkey = true;
+ if(n != n->nexthop)
+ send_packet(n->nexthop, origpkt);
+ else
+ send_tcppacket(n->nexthop->connection, origpkt);
return;
}
/* Compress the packet */
- if(n->compression) {
+ if(n->outcompression) {
outpkt = pkt[nextpkt++];
- if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->compression)) < 0) {
- ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while compressing packet to %s (%s)"),
+ if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) {
+ ifdebug(TRAFFIC) logger(LOG_ERR, "Error while compressing packet to %s (%s)",
n->name, n->hostname);
return;
}
/* Encrypt the packet */
- if(cipher_active(&n->cipher)) {
+ if(cipher_active(&n->outcipher)) {
outpkt = pkt[nextpkt++];
outlen = MAXSIZE;
- if(!cipher_encrypt(&n->cipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
- ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s)"), n->name, n->hostname);
+ if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+ ifdebug(TRAFFIC) logger(LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
goto end;
}
/* Add the message authentication code */
- if(digest_active(&n->digest)) {
- digest_create(&n->digest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len);
- inpkt->len += digest_length(&n->digest);
+ if(digest_active(&n->outdigest)) {
+ digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
+ inpkt->len += digest_length(&n->outdigest);
}
/* Determine which socket we have to use */
if(priorityinheritance && origpriority != priority
&& listen_socket[sock].sa.sa.sa_family == AF_INET) {
priority = origpriority;
- ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Setting outgoing packet priority to %d"), priority);
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
if(setsockopt(listen_socket[sock].udp, SOL_IP, IP_TOS, &priority, sizeof priority)) /* SO_PRIORITY doesn't seem to work */
- logger(LOG_ERR, _("System call `%s' failed: %s"), "setsockopt", strerror(errno));
+ logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
}
#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:
void send_packet(const node_t *n, vpn_packet_t *packet) {
node_t *via;
- cp();
-
if(n == myself) {
if(overwrite_mac)
memcpy(packet->data, mymac.x, ETH_ALEN);
return;
}
- ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
+ 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"),
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Node %s (%s) is not reachable",
n->name, n->hostname);
return;
}
- via = (n->via == myself) ? n->nexthop : n->via;
+ via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via;
if(via != n)
- ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet to %s via %s (%s)"),
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Sending packet to %s via %s (%s)",
n->name, via->name, n->via->hostname);
- if((myself->options | via->options) & OPTION_TCPONLY) {
+ if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) {
if(!send_tcppacket(via->connection, packet))
terminate_connection(via->connection, true);
} else
splay_node_t *node;
connection_t *c;
- cp();
-
- ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)",
packet->len, from->name, from->hostname);
- if(from != myself)
+ if(from != myself) {
send_packet(myself, packet);
+ // In TunnelServer mode, do not forward broadcast packets.
+ // The MST might not be valid and create loops.
+ if(tunnelserver)
+ return;
+ }
+
for(node = connection_tree->head; node; node = node->next) {
c = node->data;
}
}
-void flush_queue(node_t *n) {
- list_node_t *node, *next;
+static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
+ splay_node_t *node;
+ node_t *n, *found = NULL;
+ static time_t last_hard_try = 0;
+ time_t now = time(NULL);
+
+ if(last_hard_try == now)
+ return NULL;
+ else
+ last_hard_try = now;
- cp();
+ for(node = node_tree->head; node; node = node->next) {
+ n = node->data;
- ifdebug(TRAFFIC) logger(LOG_INFO, _("Flushing queue for %s (%s)"), n->name, n->hostname);
+ if(n == myself || !n->status.reachable || !digest_active(&n->indigest))
+ continue;
- for(node = n->queue->head; node; node = next) {
- next = node->next;
- send_udppacket(n, node->data);
- list_delete_node(n->queue, node);
+ if(try_mac(n, pkt)) {
+ found = n;
+ break;
+ }
}
+
+ 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;
- cp();
-
- 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) {
- 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);
if(!n) {
- hostname = sockaddr2hostname(&from);
- logger(LOG_WARNING, _("Received UDP packet from unknown source %s"),
- hostname);
- free(hostname);
- return;
+ n = try_harder(&from, &pkt);
+ if(n)
+ update_node_udp(n, &from);
+ else ifdebug(PROTOCOL) {
+ hostname = sockaddr2hostname(&from);
+ logger(LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
+ free(hostname);
+ return;
+ }
+ else
+ return;
}
receive_udppacket(n, &pkt);