tinc/src/subnet.c

/*
    subnet.c -- handle subnet lookups and lists
    Copyright (C) 2000-2002 Guus Sliepen <guus@sliepen.eu.org>,
                  2000-2002 Ivo Timmermans <ivo@o2w.nl>

    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: subnet.c,v 1.1.2.43 2002/09/15 14:55:54 guus Exp $
*/

#include "config.h"

#include <stdio.h>
#include <syslog.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>

#include <utils.h>
#include <xalloc.h>
#include <avl_tree.h>

#include "conf.h"
#include "net.h"
#include "node.h"
#include "subnet.h"
#include "netutl.h"

#include "system.h"

/* lists type of subnet */

avl_tree_t *subnet_tree;

/* Subnet comparison */

int subnet_compare_mac(subnet_t *a, subnet_t *b)
{
	int result;

	result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));

	if(result || !a->owner || !b->owner)
		return result;

	return strcmp(a->owner->name, b->owner->name);
}

int subnet_compare_ipv4(subnet_t *a, subnet_t *b)
{
	int result;

	result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));

	if(result)
		return result;

	result = a->net.ipv4.prefixlength - b->net.ipv4.prefixlength;

	if(result || !a->owner || !b->owner)
		return result;

	return strcmp(a->owner->name, b->owner->name);
}

int subnet_compare_ipv6(subnet_t *a, subnet_t *b)
{
	int result;

	result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));

	if(result)
		return result;

	result = a->net.ipv6.prefixlength - b->net.ipv6.prefixlength;

	if(result || !a->owner || !b->owner)
		return result;

	return strcmp(a->owner->name, b->owner->name);
}

int subnet_compare(subnet_t *a, subnet_t *b)
{
	int result;

	result = a->type - b->type;

	if(result)
		return result;

	switch (a->type) {
	case SUBNET_MAC:
		return subnet_compare_mac(a, b);
	case SUBNET_IPV4:
		return subnet_compare_ipv4(a, b);
	case SUBNET_IPV6:
		return subnet_compare_ipv6(a, b);
	default:
		syslog(LOG_ERR, _("subnet_compare() was called with unknown subnet type %d, exitting!"),
			   a->type);
		cp_trace();
		exit(0);
	}

	return 0;
}

/* Initialising trees */

void init_subnets(void)
{
	cp();

	subnet_tree = avl_alloc_tree((avl_compare_t) subnet_compare, (avl_action_t) free_subnet);
}

void exit_subnets(void)
{
	cp();

	avl_delete_tree(subnet_tree);
}

avl_tree_t *new_subnet_tree(void)
{
	cp();

	return avl_alloc_tree((avl_compare_t) subnet_compare, NULL);
}

void free_subnet_tree(avl_tree_t *subnet_tree)
{
	cp();

	avl_delete_tree(subnet_tree);
}

/* Allocating and freeing space for subnets */

subnet_t *new_subnet(void)
{
	cp();

	return (subnet_t *) xmalloc_and_zero(sizeof(subnet_t));
}

void free_subnet(subnet_t *subnet)
{
	cp();

	free(subnet);
}

/* Adding and removing subnets */

void subnet_add(node_t *n, subnet_t *subnet)
{
	cp();

	subnet->owner = n;

	avl_insert(subnet_tree, subnet);
	avl_insert(n->subnet_tree, subnet);
}

void subnet_del(node_t *n, subnet_t *subnet)
{
	cp();

	avl_delete(n->subnet_tree, subnet);
	avl_delete(subnet_tree, subnet);
}

/* Ascii representation of subnets */

subnet_t *str2net(char *subnetstr)
{
	int i, l;
	subnet_t *subnet;
	uint16_t x[8];

	cp();

	subnet = new_subnet();

	if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d",
			  &x[0], &x[1], &x[2], &x[3], &l) == 5) {
		subnet->type = SUBNET_IPV4;
		subnet->net.ipv4.prefixlength = l;

		for(i = 0; i < 4; i++)
			subnet->net.ipv4.address.x[i] = x[i];

		return subnet;
	}

	if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d",
			  &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
			  &l) == 9) {
		subnet->type = SUBNET_IPV6;
		subnet->net.ipv6.prefixlength = l;

		for(i = 0; i < 8; i++)
			subnet->net.ipv6.address.x[i] = htons(x[i]);

		return subnet;
	}

	if(sscanf(subnetstr, "%hu.%hu.%hu.%hu", &x[0], &x[1], &x[2], &x[3]) == 4) {
		subnet->type = SUBNET_IPV4;
		subnet->net.ipv4.prefixlength = 32;

		for(i = 0; i < 4; i++)
			subnet->net.ipv4.address.x[i] = x[i];

		return subnet;
	}

	if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
			  &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7]) == 8) {
		subnet->type = SUBNET_IPV6;
		subnet->net.ipv6.prefixlength = 128;

		for(i = 0; i < 8; i++)
			subnet->net.ipv6.address.x[i] = htons(x[i]);

		return subnet;
	}

	if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx",
			  &x[0], &x[1], &x[2], &x[3], &x[4], &x[5]) == 6) {
		subnet->type = SUBNET_MAC;

		for(i = 0; i < 6; i++)
			subnet->net.mac.address.x[i] = x[i];

		return subnet;
	}

	free(subnet);

	return NULL;
}

char *net2str(subnet_t *subnet)
{
	char *netstr;

	cp();

	switch (subnet->type) {
		case SUBNET_MAC:
			asprintf(&netstr, "%hx:%hx:%hx:%hx:%hx:%hx",
					 subnet->net.mac.address.x[0],
					 subnet->net.mac.address.x[1],
					 subnet->net.mac.address.x[2],
					 subnet->net.mac.address.x[3],
					 subnet->net.mac.address.x[4], subnet->net.mac.address.x[5]);
			break;

		case SUBNET_IPV4:
			asprintf(&netstr, "%hu.%hu.%hu.%hu/%d",
					 subnet->net.ipv4.address.x[0],
					 subnet->net.ipv4.address.x[1],
					 subnet->net.ipv4.address.x[2],
					 subnet->net.ipv4.address.x[3], subnet->net.ipv4.prefixlength);
			break;

		case SUBNET_IPV6:
			asprintf(&netstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d",
					 ntohs(subnet->net.ipv6.address.x[0]),
					 ntohs(subnet->net.ipv6.address.x[1]),
					 ntohs(subnet->net.ipv6.address.x[2]),
					 ntohs(subnet->net.ipv6.address.x[3]),
					 ntohs(subnet->net.ipv6.address.x[4]),
					 ntohs(subnet->net.ipv6.address.x[5]),
					 ntohs(subnet->net.ipv6.address.x[6]),
					 ntohs(subnet->net.ipv6.address.x[7]),
					 subnet->net.ipv6.prefixlength);
			break;

		default:
			syslog(LOG_ERR,
				   _("net2str() was called with unknown subnet type %d, exiting!"),
				   subnet->type);
			cp_trace();
			exit(0);
	}

	return netstr;
}

/* Subnet lookup routines */

subnet_t *lookup_subnet(node_t *owner, subnet_t *subnet)
{
	cp();

	return avl_search(owner->subnet_tree, subnet);
}

subnet_t *lookup_subnet_mac(mac_t *address)
{
	subnet_t subnet, *p;

	cp();

	subnet.type = SUBNET_MAC;
	memcpy(&subnet.net.mac.address, address, sizeof(mac_t));
	subnet.owner = NULL;

	p = (subnet_t *) avl_search(subnet_tree, &subnet);

	return p;
}

subnet_t *lookup_subnet_ipv4(ipv4_t *address)
{
	subnet_t subnet, *p;

	cp();

	subnet.type = SUBNET_IPV4;
	memcpy(&subnet.net.ipv4.address, address, sizeof(ipv4_t));
	subnet.net.ipv4.prefixlength = 32;
	subnet.owner = NULL;

	do {
		/* Go find subnet */

		p = (subnet_t *) avl_search_closest_smaller(subnet_tree, &subnet);

		/* Check if the found subnet REALLY matches */

		if(p) {
			if(p->type != SUBNET_IPV4) {
				p = NULL;
				break;
			}

			if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength, sizeof(ipv4_t)))
				break;
			else {
				/* Otherwise, see if there is a bigger enclosing subnet */

				subnet.net.ipv4.prefixlength = p->net.ipv4.prefixlength - 1;
				maskcpy(&subnet.net.ipv4.address, &p->net.ipv4.address, subnet.net.ipv4.prefixlength, sizeof(ipv4_t));
			}
		}
	} while(p);

	return p;
}

subnet_t *lookup_subnet_ipv6(ipv6_t *address)
{
	subnet_t subnet, *p;

	cp();

	subnet.type = SUBNET_IPV6;
	memcpy(&subnet.net.ipv6.address, address, sizeof(ipv6_t));
	subnet.net.ipv6.prefixlength = 128;
	subnet.owner = NULL;

	do {
		/* Go find subnet */

		p = (subnet_t *) avl_search_closest_smaller(subnet_tree, &subnet);

		/* Check if the found subnet REALLY matches */

		if(p) {
			if(p->type != SUBNET_IPV6)
				return NULL;

			if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength, sizeof(ipv6_t)))
				break;
			else {
				/* Otherwise, see if there is a bigger enclosing subnet */

				subnet.net.ipv6.prefixlength = p->net.ipv6.prefixlength - 1;
				maskcpy(&subnet.net.ipv6.address, &p->net.ipv6.address, subnet.net.ipv6.prefixlength, sizeof(ipv6_t));
			}
		}
	} while(p);

	return p;
}

void dump_subnets(void)
{
	char *netstr;
	subnet_t *subnet;
	avl_node_t *node;

	cp();

	syslog(LOG_DEBUG, _("Subnet list:"));

	for(node = subnet_tree->head; node; node = node->next) {
		subnet = (subnet_t *) node->data;
		netstr = net2str(subnet);
		syslog(LOG_DEBUG, _(" %s owner %s"), netstr, subnet->owner->name);
		free(netstr);
	}

	syslog(LOG_DEBUG, _("End of subnet list."));
}