relayd/main.c

/*
 *   Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License v2 as published by
 *   the Free Software Foundation.
 *
 *   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., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 */
#include <sys/ioctl.h>
#include <sys/socket.h>

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <signal.h>
#include <string.h>

#include "relayd.h"

static LIST_HEAD(pending_routes);
LIST_HEAD(interfaces);
int debug;

static int host_timeout;
static int host_ping_tries;
static int inet_sock;
static int forward_bcast;
static int forward_dhcp;
static int parse_dhcp;

uint8_t local_addr[4];
int local_route_table;

struct relayd_pending_route {
	struct relayd_route rt;
	struct uloop_timeout timeout;
	uint8_t gateway[4];
};

static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
{
	struct relayd_host *host;

	if (!rif) {
		list_for_each_entry(rif, &interfaces, list) {
			host = find_host_by_ipaddr(rif, ipaddr);
			if (!host)
				continue;

			return host;
		}
		return NULL;
	}

	list_for_each_entry(host, &rif->hosts, list) {
		if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
			continue;

		return host;
	}
	return NULL;
}

static void add_arp(struct relayd_host *host)
{
	struct sockaddr_in *sin;
	struct arpreq arp;

	strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
	arp.arp_flags = ATF_COM;

	arp.arp_ha.sa_family = ARPHRD_ETHER;
	memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);

	sin = (struct sockaddr_in *) &arp.arp_pa;
	sin->sin_family = AF_INET;
	memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));

	ioctl(inet_sock, SIOCSARP, &arp);
}

static void timeout_host_route(struct uloop_timeout *timeout)
{
	struct relayd_pending_route *rt;

	rt = container_of(timeout, struct relayd_pending_route, timeout);
	list_del(&rt->rt.list);
	free(rt);
}

void relayd_add_host_route(struct relayd_host *host, const uint8_t *dest, uint8_t mask)
{
	struct relayd_route *rt;

	list_for_each_entry(rt, &host->routes, list) {
		if (!memcmp(rt->dest, dest, sizeof(rt->dest)) && rt->mask == mask)
			return;
	}

	rt = calloc(1, sizeof(*rt));
	if (!rt)
		return;

	list_add(&rt->list, &host->routes);
	memcpy(rt->dest, dest, sizeof(rt->dest));
	rt->mask = mask;
	relayd_add_route(host, rt);
}

static void del_host(struct relayd_host *host)
{
	struct relayd_route *route, *tmp;

	DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
		IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));

	list_for_each_entry_safe(route, tmp, &host->routes, list) {
		relayd_del_route(host, route);
		list_del(&route->list);
		free(route);
	}
	if (host->rif->managed)
		relayd_del_route(host, NULL);
	uloop_timeout_cancel(&host->timeout);
	list_del(&host->list);
	free(host);
}

static void fill_arp_packet(struct arp_packet *pkt, struct relayd_interface *rif,
                             const uint8_t spa[4], const uint8_t tpa[4])
{
	memset(pkt, 0, sizeof(*pkt));

	pkt->eth.ether_type = htons(ETHERTYPE_ARP);
	memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);

	memcpy(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
	memcpy(pkt->arp.arp_spa, spa, 4);
	memcpy(pkt->arp.arp_tpa, tpa, 4);

	pkt->arp.arp_hrd = htons(ARPHRD_ETHER);
	pkt->arp.arp_pro = htons(ETH_P_IP);
	pkt->arp.arp_hln = ETH_ALEN;
	pkt->arp.arp_pln = 4;
}

static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr)
{
	struct arp_packet pkt;

	fill_arp_packet(&pkt, rif, rif->src_ip, ipaddr);

	pkt.arp.arp_op = htons(ARPOP_REQUEST);
	memcpy(pkt.arp.arp_spa, rif->src_ip, sizeof(pkt.arp.arp_spa));
	memset(pkt.arp.arp_tha, 0, ETH_ALEN);
	memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);

	DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
		rif->ifname, IP_BUF(pkt.arp.arp_tpa),
		IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));

	sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
		(struct sockaddr *) &rif->sll, sizeof(rif->sll));
}

void relayd_add_pending_route(const uint8_t *gateway, const uint8_t *dest, uint8_t mask, int timeout)
{
	struct relayd_pending_route *rt;
	struct relayd_interface *rif;
	struct relayd_host *host;

	host = find_host_by_ipaddr(NULL, gateway);
	if (host) {
		relayd_add_host_route(host, dest, mask);
		return;
	}

	rt = calloc(1, sizeof(*rt));
	if (!rt)
		return;

	memcpy(rt->gateway, gateway, sizeof(rt->gateway));
	memcpy(rt->rt.dest, dest, sizeof(rt->rt.dest));
	rt->rt.mask = mask;
	list_add(&rt->rt.list, &pending_routes);
	if (timeout <= 0)
		return;

	rt->timeout.cb = timeout_host_route;
	uloop_timeout_set(&rt->timeout, 10000);
	list_for_each_entry(rif, &interfaces, list) {
		send_arp_request(rif, gateway);
	}
}

static void send_arp_reply(struct relayd_interface *rif, const uint8_t spa[4],
                           const uint8_t tha[ETH_ALEN], const uint8_t tpa[4])
{
	struct arp_packet pkt;

	fill_arp_packet(&pkt, rif, spa, tpa);

	if (tha) {
		pkt.arp.arp_op = htons(ARPOP_REPLY);
		memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
		memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);

		DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
			rif->ifname, IP_BUF(pkt.arp.arp_tpa),
			IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
	} else {
		pkt.arp.arp_op = htons(ARPOP_REQUEST);
		memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
		memset(pkt.arp.arp_tha, 0xff, ETH_ALEN);

		DPRINTF(2, "%s: sending gratuitous ARP: "IP_FMT" is at ("MAC_FMT")\n",
			rif->ifname, IP_BUF(pkt.arp.arp_tpa),
			MAC_BUF(pkt.eth.ether_shost));
	}

	sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
		(struct sockaddr *) &rif->sll, sizeof(rif->sll));

	if (tha)
		return;

	/*
	 * Gratuitous ARP comes in two flavours, request and reply.
	 * Some operating systems only accept request, some only reply.
	 * Let's just send both...
	 */
	pkt.arp.arp_op = htons(ARPOP_REPLY);

	sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
		(struct sockaddr *) &rif->sll, sizeof(rif->sll));

}

static void host_entry_timeout(struct uloop_timeout *timeout)
{
	struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
	struct relayd_interface *rif;

	/*
	 * When a host is behind a managed interface, we must not expire its host
	 * entry prematurely, as this will cause routes to the node to expire,
	 * leading to loss of connectivity from the other side.
	 * When the timeout is reached, try pinging the host a few times before
	 * giving up on it.
	 */
	if (host->rif->managed && host->cleanup_pending < host_ping_tries) {
		list_for_each_entry(rif, &interfaces, list) {
			send_arp_request(rif, host->ipaddr);
		}
		host->cleanup_pending++;
		uloop_timeout_set(&host->timeout, 1000);
		return;
	}
	del_host(host);
}

static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
{
	struct relayd_host *host;
	struct relayd_pending_route *route, *rtmp;

	DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
			IP_BUF(ipaddr), MAC_BUF(lladdr));

	host = calloc(1, sizeof(*host));
	INIT_LIST_HEAD(&host->routes);
	host->rif = rif;
	memcpy(host->ipaddr, ipaddr, sizeof(host->ipaddr));
	memcpy(host->lladdr, lladdr, sizeof(host->lladdr));
	list_add(&host->list, &rif->hosts);
	host->timeout.cb = host_entry_timeout;
	uloop_timeout_set(&host->timeout, host_timeout * 1000);

	add_arp(host);
	if (rif->managed)
		relayd_add_route(host, NULL);

	list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
		if (memcmp(route->gateway, ipaddr, 4) != 0)
			continue;

		relayd_add_host_route(host, route->rt.dest, route->rt.mask);
		if (!route->timeout.pending)
			continue;

		uloop_timeout_cancel(&route->timeout);
		list_del(&route->rt.list);
		free(route);
	}

	return host;
}

static void send_gratuitous_arp(struct relayd_interface *rif, const uint8_t *spa)
{
	struct relayd_interface *to_rif;

	list_for_each_entry(to_rif, &interfaces, list) {
		if (rif == to_rif)
			continue;

		send_arp_reply(to_rif, spa, NULL, spa);
	}
}


struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
{
	struct relayd_host *host;

	host = find_host_by_ipaddr(rif, ipaddr);
	if (!host) {
		host = find_host_by_ipaddr(NULL, ipaddr);

		/* 
		 * When we suddenly see the host appearing on a different interface,
		 * reduce the timeout to make the old entry expire faster, in case the
		 * host has moved.
		 * If the old entry is behind a managed interface, it will be pinged
		 * before we expire it
		 */
		if (host && !host->cleanup_pending) {
			uloop_timeout_set(&host->timeout, 1);
			return NULL;
		}

		host = add_host(rif, lladdr, ipaddr);
	} else {
		host->cleanup_pending = false;
		uloop_timeout_set(&host->timeout, host_timeout * 1000);
		send_gratuitous_arp(rif, ipaddr);
	}

	return host;
}

static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
{
	struct relayd_interface *rif;
	struct arp_packet reqpkt;

	memcpy(&reqpkt, pkt, sizeof(reqpkt));
	list_for_each_entry(rif, &interfaces, list) {
		if (rif == from_rif)
			continue;

		memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
		memset(reqpkt.eth.ether_dhost, 0xff, ETH_ALEN);
		memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
		memset(reqpkt.arp.arp_tha, 0, ETH_ALEN);

		DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
			rif->ifname, IP_BUF(reqpkt.arp.arp_tpa),
			IP_BUF(reqpkt.arp.arp_spa), MAC_BUF(reqpkt.eth.ether_shost));

		sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
			(struct sockaddr *) &rif->sll, sizeof(rif->sll));
	}
}

static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
{
	struct relayd_host *host;

	DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
		rif->ifname,
		IP_BUF(pkt->arp.arp_tpa),
		IP_BUF(pkt->arp.arp_spa),
		MAC_BUF(pkt->eth.ether_shost));

	if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
		return;

	host = find_host_by_ipaddr(NULL, pkt->arp.arp_spa);
	if (!host || host->rif != rif)
		relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);

	if (local_route_table && !memcmp(pkt->arp.arp_tpa, local_addr, sizeof(local_addr))) {
		send_arp_reply(rif, local_addr, pkt->arp.arp_sha, pkt->arp.arp_spa);
		return;
	}

	host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);

	/*
	 * If a host is being pinged because of a timeout, do not use the cached
	 * entry here. That way we can avoid giving out stale data in case the node
	 * has moved. We shouldn't relay requests here either, as we might miss our
	 * chance to create a host route.
	 */
	if (host && host->cleanup_pending)
		return;

	relay_arp_request(rif, pkt);
}

static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
{
	struct relayd_host *host;

	DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
		rif->ifname,
		IP_BUF(pkt->arp.arp_spa),
		MAC_BUF(pkt->eth.ether_shost),
		IP_BUF(pkt->arp.arp_tpa));

	if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
		relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);

	host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
	if (!host)
		return;

	if (host->rif == rif)
		return;

	send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
}

static void recv_packet(struct uloop_fd *fd, unsigned int events)
{
	struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
	struct arp_packet *pkt;
	static char pktbuf[4096];
	int pktlen;

	do {
		if (rif->fd.error)
			uloop_end();

		pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
		if (pktlen < 0) {
			if (errno == EINTR)
				continue;

			break;
		}

		if (!pktlen)
			break;

		pkt = (void *)pktbuf;
		if (pkt->arp.arp_op == htons(ARPOP_REPLY))
			recv_arp_reply(rif, pkt);
		else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
			recv_arp_request(rif, pkt);
		else
			DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));

	} while (1);
}

void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
{
	struct relayd_interface *rif;
	struct ether_header *eth = packet;

	list_for_each_entry(rif, &interfaces, list) {
		if (rif == from_rif)
			continue;

		DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
		memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
		send(rif->bcast_fd.fd, packet, len, 0);
	}
}

static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
{
	struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
	static char pktbuf[4096];
	int pktlen;

	do {
		if (rif->fd.error)
			uloop_end();

		pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
		if (pktlen < 0) {
			if (errno == EINTR)
				continue;

			break;
		}

		if (!pktlen)
			break;

		if (!forward_bcast && !forward_dhcp)
			continue;

		if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp, parse_dhcp))
			continue;

		if (forward_bcast)
			relayd_forward_bcast_packet(rif, pktbuf, pktlen);
	} while (1);
}


static int init_interface(struct relayd_interface *rif)
{
	struct sockaddr_ll *sll = &rif->sll;
	struct sockaddr_in *sin;
	struct ifreq ifr;
	int fd = rif->fd.fd;
#ifdef PACKET_RECV_TYPE
	unsigned int pkt_type;
#endif

	fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
	if (fd < 0)
		return -1;

	rif->fd.fd = fd;

	memset(&ifr, 0, sizeof(ifr));
	strcpy(ifr.ifr_name, rif->ifname);

	if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
		perror("ioctl(SIOCGIFHWADDR)");
		return -1;
	}

	memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
	sll->sll_family = AF_PACKET;
	sll->sll_protocol = htons(ETH_P_ARP);
	sll->sll_pkttype = PACKET_BROADCAST;
	sll->sll_hatype = ARPHRD_ETHER;
	sll->sll_halen = ETH_ALEN;

	if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
		perror("ioctl(SIOCGIFINDEX)");
		return -1;
	}

	sll->sll_ifindex = ifr.ifr_ifindex;

	if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
		memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
	} else {
		sin = (struct sockaddr_in *) &ifr.ifr_addr;
		memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
	}

	if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
		perror("bind(ETH_P_ARP)");
		return -1;
	}

	rif->fd.cb = recv_packet;
	uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);

	if (!forward_bcast && !forward_dhcp)
		return 0;

	fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
	if (fd < 0)
		return 0;

	rif->bcast_fd.fd = fd;
	rif->bcast_fd.cb = recv_bcast_packet;

	memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
	sll = &rif->bcast_sll;
	sll->sll_protocol = htons(ETH_P_IP);

	if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
		perror("bind(ETH_P_IP)");
		return 0;
	}

#ifdef PACKET_RECV_TYPE
	pkt_type = (1 << PACKET_BROADCAST) | (1 << PACKET_MULTICAST);
	setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
#endif

	uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
	relayd_add_interface_routes(rif);
	return 0;
}

static void ping_static_routes(void)
{
	struct relayd_pending_route *rt;
	struct relayd_interface *rif;

	list_for_each_entry(rt, &pending_routes, rt.list)
		list_for_each_entry(rif, &interfaces, list)
			send_arp_request(rif, rt->gateway);
}

static int init_interfaces(void)
{
	struct relayd_interface *rif;
	int ret;

	list_for_each_entry(rif, &interfaces, list) {
		ret = init_interface(rif);
		if (ret < 0)
			return ret;
	}

	return 0;
}

static void cleanup_hosts(void)
{
	struct relayd_interface *rif;
	struct relayd_host *host, *tmp;

	list_for_each_entry(rif, &interfaces, list) {
		list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
			del_host(host);
		}
	}
}

static void free_interfaces(void)
{
	struct relayd_interface *rif, *rtmp;

	list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
		relayd_del_interface_routes(rif);
		list_del(&rif->list);
		free(rif);
	}
}

static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
{
	struct relayd_interface *rif;

	if (strlen(ifname) >= IFNAMSIZ)
		return NULL;

	list_for_each_entry(rif, &interfaces, list) {
		if (!strncmp(rif->ifname, ifname, IFNAMSIZ))
			return rif;
	}

	rif = calloc(1, sizeof(*rif));
	if (!rif)
		return NULL;

	INIT_LIST_HEAD(&rif->hosts);
	strcpy(rif->ifname, ifname);
	list_add(&rif->list, &interfaces);
	rif->managed = managed;

	return rif;
}

static void die(int signo)
{
	/*
	 * When we hit SIGTERM, clean up interfaces directly, so that we
	 * won't leave our routing in an invalid state.
	 */
	uloop_end();
}

static int usage(const char *progname)
{
	fprintf(stderr, "Usage: %s <options>\n"
			"\n"
			"Options:\n"
			"	-d		Enable debug messages\n"
			"	-i <ifname>	Add an interface for relaying\n"
			"	-I <ifname>	Same as -i, except with ARP cache and host route management\n"
			"			You need to specify at least two interfaces\n"
			"	-G <ip>		Set a gateway IP for clients\n"
			"	-R <gateway>:<net>/<mask>\n"
			"			Add a static route for <net>/<mask> via <gateway>\n"
			"	-t <timeout>	Host entry expiry timeout\n"
			"	-p <tries>	Number of ARP ping attempts before considering a host dead\n"
			"	-T <table>	Set routing table number for automatically added routes\n"
			"	-B		Enable broadcast forwarding\n"
			"	-D		Enable DHCP forwarding\n"
			"	-P		Disable DHCP options parsing\n"
			"	-L <ipaddr>	Enable local access using <ipaddr> as source address\n"
			"\n",
		progname);
	return -1;
}

int main(int argc, char **argv)
{
	struct relayd_interface *rif = NULL;
	struct in_addr addr, addr2;
	bool local_addr_valid = false;
	bool managed = false;
	int ifnum = 0;
	char *s, *s2;
	int mask;
	int ch;

	debug = 0;
	inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
	if (inet_sock < 0) {
		perror("socket(AF_INET)");
		return 1;
	}

	host_timeout = 30;
	host_ping_tries = 5;
	forward_bcast = 0;
	local_route_table = 0;
	parse_dhcp = 1;
	uloop_init();

	while ((ch = getopt(argc, argv, "I:i:t:p:BDPdT:G:R:L:")) != -1) {
		switch(ch) {
		case 'I':
			managed = true;
			/* fall through */
		case 'i':
			ifnum++;
			rif = alloc_interface(optarg, managed);
			if (!rif)
				return 1;

			managed = false;
			break;
		case 't':
			host_timeout = atoi(optarg);
			if (host_timeout <= 0)
				return usage(argv[0]);
			break;
		case 'p':
			host_ping_tries = atoi(optarg);
			if (host_ping_tries <= 0)
				return usage(argv[0]);
			break;
		case 'd':
			debug++;
			break;
		case 'B':
			forward_bcast = 1;
			break;
		case 'D':
			forward_dhcp = 1;
			break;
		case 'P':
			parse_dhcp = 0;
			break;
		case 'T':
			route_table = atoi(optarg);
			if (route_table <= 0)
				return usage(argv[0]);
			break;
		case 'G':
			if (!inet_aton(optarg, &addr)) {
				fprintf(stderr, "Address '%s' not found\n", optarg);
				return 1;
			}
			relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
			break;
		case 'L':
			if (!inet_aton(optarg, &addr)) {
				fprintf(stderr, "Address '%s' not found\n", optarg);
				return 1;
			}
			memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
			local_addr_valid = true;
			break;
		case 'R':
			s = strchr(optarg, ':');
			if (!s)
				return usage(argv[0]);

			*(s++) = 0;
			if (!inet_aton(optarg, &addr)) {
				fprintf(stderr, "Address '%s' not found\n", optarg);
				return 1;
			}

			s2 = strchr(s, '/');
			if (!s2)
				return usage(argv[0]);

			*(s2++) = 0;
			if (!inet_aton(s, &addr2)) {
				fprintf(stderr, "Address '%s' not found\n", s);
				return 1;
			}

			mask = atoi(s2);
			if (mask < 0 || mask > 32)
				return usage(argv[0]);

			relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
			break;
		case '?':
		default:
			return usage(argv[0]);
		}
	}

	if (list_empty(&interfaces))
		return usage(argv[0]);

	if (ifnum < 2) {
		fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
		return -1;
	}

	argc -= optind;
	argv += optind;

	signal(SIGTERM, die);
	signal(SIGHUP, die);
	signal(SIGUSR1, die);
	signal(SIGUSR2, die);

	if (local_addr_valid)
		local_route_table = route_table++;

	if (relayd_rtnl_init() < 0)
		return 1;

	if (init_interfaces() < 0)
		return 1;

	ping_static_routes();

	uloop_run();
	uloop_done();

	cleanup_hosts();
	free_interfaces();
	relayd_rtnl_done();
	close(inet_sock);

	return 0;
}