tinc/src/node.c
Guus Sliepen 3308d13e7e Handle UDP packets from different and ports than advertised.
Previously, tinc used a fixed address and port for each node for UDP packet
exchange.  The port was the one advertised by that node as its listening port.
However, due to NAT the port might be different.  Now, tinc sends a different
session key to each node. This way, the sending node can be determined from
incoming packets by checking the MAC against all session keys. If a match is
found, the address and port for that node are updated.
2009-04-03 01:05:23 +02:00

205 lines
4.1 KiB
C

/*
node.c -- node tree management
Copyright (C) 2001-2009 Guus Sliepen <guus@tinc-vpn.org>,
2001-2005 Ivo Timmermans
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
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
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.
$Id$
*/
#include "system.h"
#include "avl_tree.h"
#include "logger.h"
#include "net.h"
#include "netutl.h"
#include "node.h"
#include "utils.h"
#include "xalloc.h"
avl_tree_t *node_tree; /* Known nodes, sorted by name */
avl_tree_t *node_udp_tree; /* Known nodes, sorted by address and port */
node_t *myself;
static int node_compare(const node_t *a, const node_t *b)
{
return strcmp(a->name, b->name);
}
static int node_udp_compare(const node_t *a, const node_t *b)
{
return sockaddrcmp(&a->address, &b->address);
}
void init_nodes(void)
{
cp();
node_tree = avl_alloc_tree((avl_compare_t) node_compare, (avl_action_t) free_node);
node_udp_tree = avl_alloc_tree((avl_compare_t) node_udp_compare, NULL);
}
void exit_nodes(void)
{
cp();
avl_delete_tree(node_udp_tree);
avl_delete_tree(node_tree);
}
node_t *new_node(void)
{
node_t *n = xmalloc_and_zero(sizeof(*n));
cp();
n->subnet_tree = new_subnet_tree();
n->edge_tree = new_edge_tree();
EVP_CIPHER_CTX_init(&n->inctx);
EVP_CIPHER_CTX_init(&n->outctx);
n->mtu = MTU;
n->maxmtu = MTU;
return n;
}
void free_node(node_t *n)
{
cp();
if(n->inkey)
free(n->inkey);
if(n->outkey)
free(n->outkey);
if(n->subnet_tree)
free_subnet_tree(n->subnet_tree);
if(n->edge_tree)
free_edge_tree(n->edge_tree);
sockaddrfree(&n->address);
EVP_CIPHER_CTX_cleanup(&n->inctx);
EVP_CIPHER_CTX_cleanup(&n->outctx);
if(n->mtuevent)
event_del(n->mtuevent);
if(n->hostname)
free(n->hostname);
if(n->name)
free(n->name);
free(n);
}
void node_add(node_t *n)
{
cp();
avl_insert(node_tree, n);
}
void node_del(node_t *n)
{
avl_node_t *node, *next;
edge_t *e;
subnet_t *s;
cp();
for(node = n->subnet_tree->head; node; node = next) {
next = node->next;
s = node->data;
subnet_del(n, s);
}
for(node = n->edge_tree->head; node; node = next) {
next = node->next;
e = node->data;
edge_del(e);
}
avl_delete(node_tree, n);
avl_delete(node_udp_tree, n);
}
node_t *lookup_node(char *name)
{
node_t n = {0};
cp();
n.name = name;
return avl_search(node_tree, &n);
}
node_t *lookup_node_udp(const sockaddr_t *sa)
{
node_t n = {0};
cp();
n.address = *sa;
n.name = NULL;
return avl_search(node_udp_tree, &n);
}
void update_node_udp(node_t *n, const sockaddr_t *sa)
{
avl_delete(node_udp_tree, n);
if(n->hostname)
free(n->hostname);
if(sa) {
n->address = *sa;
n->hostname = sockaddr2hostname(&n->address);
avl_delete(node_udp_tree, n);
avl_insert(node_udp_tree, n);
logger(LOG_DEBUG, "UDP address of %s set to %s", n->name, n->hostname);
} else {
memset(&n->address, 0, sizeof n->address);
logger(LOG_DEBUG, "UDP address of %s cleared", n->name);
}
}
void dump_nodes(void)
{
avl_node_t *node;
node_t *n;
cp();
logger(LOG_DEBUG, _("Nodes:"));
for(node = node_tree->head; node; node = node->next) {
n = node->data;
logger(LOG_DEBUG, _(" %s at %s cipher %d digest %d maclength %d compression %d options %lx status %04x nexthop %s via %s pmtu %d (min %d max %d)"),
n->name, n->hostname, n->outcipher ? n->outcipher->nid : 0,
n->outdigest ? n->outdigest->type : 0, n->outmaclength, n->outcompression,
n->options, *(uint32_t *)&n->status, n->nexthop ? n->nexthop->name : "-",
n->via ? n->via->name : "-", n->mtu, n->minmtu, n->maxmtu);
}
logger(LOG_DEBUG, _("End of nodes."));
}