2 * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
18 #include <sys/ioctl.h>
20 #include <arpa/inet.h>
22 #include <net/ethernet.h>
23 #include <netinet/if_ether.h>
24 #include <netinet/ip.h>
25 #include <netinet/udp.h>
27 #include <linux/if_packet.h>
28 #include <linux/rtnetlink.h>
29 #include <linux/neighbour.h>
47 #define DPRINTF(level, ...) if (debug >= level) fprintf(stderr, __VA_ARGS__);
49 #define DPRINTF(...) do {} while(0)
53 #define __packed __attribute__((packed))
56 #define __uc(c) ((unsigned char *)(c))
58 #define MAC_FMT "%02x:%02x:%02x:%02x:%02x:%02x"
59 #define MAC_BUF(_c) __uc(_c)[0], __uc(_c)[1], __uc(_c)[2], __uc(_c)[3], __uc(_c)[4], __uc(_c)[5]
61 #define IP_FMT "%d.%d.%d.%d"
62 #define IP_BUF(_c) __uc(_c)[0], __uc(_c)[1], __uc(_c)[2], __uc(_c)[3]
64 #define DUMMY_IP ((uint8_t *) "\x01\x01\x01\x01")
66 #define DHCP_FLAG_BROADCAST (1 << 15)
68 struct relayd_interface {
69 struct list_head list;
71 struct uloop_fd bcast_fd;
72 struct sockaddr_ll sll;
73 struct sockaddr_ll bcast_sll;
74 char ifname[IFNAMSIZ];
75 struct list_head hosts;
81 struct list_head list;
82 struct relayd_interface *rif;
83 uint8_t lladdr[ETH_ALEN];
85 struct uloop_timeout timeout;
90 struct ether_header eth;
95 struct ether_header eth;
100 uint8_t op, htype, hlen, hops;
102 uint16_t secs, flags;
103 struct in_addr ciaddr, yiaddr, siaddr, giaddr;
104 unsigned char chaddr[16];
105 unsigned char sname[64];
106 unsigned char file[128];
115 static LIST_HEAD(interfaces);
116 static int host_timeout;
117 static int inet_sock;
118 static int forward_bcast;
119 static int forward_dhcp;
120 static struct uloop_fd rtnl_sock;
121 static unsigned int rtnl_seq, rtnl_dump_seq;
123 static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
125 struct relayd_host *host;
128 list_for_each_entry(rif, &interfaces, list) {
129 host = find_host_by_ipaddr(rif, ipaddr);
138 list_for_each_entry(host, &rif->hosts, list) {
139 if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
147 static void add_arp(struct relayd_host *host)
149 struct sockaddr_in *sin;
152 strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
153 arp.arp_flags = ATF_COM;
155 arp.arp_ha.sa_family = ARPHRD_ETHER;
156 memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);
158 sin = (struct sockaddr_in *) &arp.arp_pa;
159 sin->sin_family = AF_INET;
160 memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));
162 ioctl(inet_sock, SIOCSARP, &arp);
165 static void rtnl_route_set(struct relayd_host *host, bool add)
180 memset(&req, 0, sizeof(req));
182 req.nl.nlmsg_len = sizeof(req);
183 req.rt.rtm_family = AF_INET;
184 req.rt.rtm_dst_len = 32;
186 req.dst.rta.rta_type = RTA_DST;
187 req.dst.rta.rta_len = sizeof(req.dst);
188 memcpy(req.dst.ipaddr, host->ipaddr, sizeof(req.dst.ipaddr));
190 req.dev.rta.rta_type = RTA_OIF;
191 req.dev.rta.rta_len = sizeof(req.dev);
192 req.dev.ifindex = host->rif->sll.sll_ifindex;
194 req.nl.nlmsg_flags = NLM_F_REQUEST;
195 req.rt.rtm_table = RT_TABLE_MAIN;
197 req.nl.nlmsg_type = RTM_NEWROUTE;
198 req.nl.nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE;
200 req.rt.rtm_protocol = RTPROT_BOOT;
201 req.rt.rtm_scope = RT_SCOPE_LINK;
202 req.rt.rtm_type = RTN_UNICAST;
204 req.nl.nlmsg_type = RTM_DELROUTE;
205 req.rt.rtm_scope = RT_SCOPE_NOWHERE;
208 send(rtnl_sock.fd, &req, sizeof(req), 0);
211 static void add_route(struct relayd_host *host)
213 rtnl_route_set(host, true);
216 static void del_route(struct relayd_host *host)
218 rtnl_route_set(host, false);
221 static void del_host(struct relayd_host *host)
223 DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
224 IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));
226 if (host->rif->managed)
228 list_del(&host->list);
232 static void fill_arp_request(struct arp_packet *pkt, struct relayd_interface *rif,
233 uint8_t spa[4], uint8_t tpa[4])
235 memset(pkt, 0, sizeof(*pkt));
237 pkt->eth.ether_type = htons(ETHERTYPE_ARP);
238 memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
240 memcpy(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
241 memcpy(pkt->arp.arp_spa, spa, 4);
242 memcpy(pkt->arp.arp_tpa, tpa, 4);
244 pkt->arp.arp_hrd = htons(ARPHRD_ETHER);
245 pkt->arp.arp_pro = htons(ETH_P_IP);
246 pkt->arp.arp_hln = ETH_ALEN;
247 pkt->arp.arp_pln = 4;
250 static void send_arp_request(struct relayd_host *host)
252 struct relayd_interface *rif = host->rif;
253 struct arp_packet pkt;
255 fill_arp_request(&pkt, host->rif, host->rif->src_ip, host->ipaddr);
257 pkt.arp.arp_op = htons(ARPOP_REQUEST);
258 memcpy(pkt.arp.arp_spa, rif->src_ip, ETH_ALEN);
259 memset(pkt.arp.arp_tha, 0, ETH_ALEN);
260 memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
262 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
263 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
264 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
266 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
267 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
270 static void send_arp_reply(struct relayd_interface *rif, uint8_t spa[4],
271 uint8_t tha[ETH_ALEN], uint8_t tpa[4])
273 struct arp_packet pkt;
275 fill_arp_request(&pkt, rif, spa, tpa);
277 pkt.arp.arp_op = htons(ARPOP_REPLY);
278 memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
279 memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);
281 DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
282 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
283 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
285 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
286 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
289 static void host_entry_timeout(struct uloop_timeout *timeout)
291 struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
294 * When a host is behind a managed interface, we must not expire its host
295 * entry prematurely, as this will cause routes to the node to expire,
296 * leading to loss of connectivity from the other side.
297 * When the timeout is reached, try pinging the host a few times before
300 if (host->rif->managed && host->cleanup_pending < 2) {
301 send_arp_request(host);
302 host->cleanup_pending++;
303 uloop_timeout_set(&host->timeout, 1000);
309 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
311 struct relayd_host *host;
313 DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
314 IP_BUF(ipaddr), MAC_BUF(lladdr));
316 host = calloc(1, sizeof(*host));
318 memcpy(host->ipaddr, ipaddr, sizeof(host->ipaddr));
319 memcpy(host->lladdr, lladdr, sizeof(host->lladdr));
320 list_add(&host->list, &rif->hosts);
321 host->timeout.cb = host_entry_timeout;
322 uloop_timeout_set(&host->timeout, host_timeout * 1000);
331 static struct relayd_host *refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
333 struct relayd_host *host;
335 host = find_host_by_ipaddr(rif, ipaddr);
337 host = find_host_by_ipaddr(NULL, ipaddr);
340 * When we suddenly see the host appearing on a different interface,
341 * reduce the timeout to make the old entry expire faster, in case the
343 * If the old entry is behind a managed interface, it will be pinged
344 * before we expire it
346 if (host && !host->cleanup_pending)
347 uloop_timeout_set(&host->timeout, 1);
349 host = add_host(rif, lladdr, ipaddr);
351 host->cleanup_pending = false;
352 uloop_timeout_set(&host->timeout, host_timeout * 1000);
358 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
360 struct relayd_interface *rif;
361 struct arp_packet reqpkt;
363 memcpy(&reqpkt, pkt, sizeof(reqpkt));
364 list_for_each_entry(rif, &interfaces, list) {
368 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
369 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
371 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
372 rif->ifname, IP_BUF(reqpkt.arp.arp_tpa),
373 IP_BUF(reqpkt.arp.arp_spa), MAC_BUF(reqpkt.eth.ether_shost));
375 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
376 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
380 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
382 struct relayd_host *host;
384 DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
386 IP_BUF(pkt->arp.arp_tpa),
387 IP_BUF(pkt->arp.arp_spa),
388 MAC_BUF(pkt->eth.ether_shost));
390 if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
393 refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
395 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
398 * If a host is being pinged because of a timeout, do not use the cached
399 * entry here. That way we can avoid giving out stale data in case the node
400 * has moved. We shouldn't relay requests here either, as we might miss our
401 * chance to create a host route.
403 if (host && host->cleanup_pending)
406 relay_arp_request(rif, pkt);
410 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
412 struct relayd_host *host;
414 DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
416 IP_BUF(pkt->arp.arp_spa),
417 MAC_BUF(pkt->eth.ether_shost),
418 IP_BUF(pkt->arp.arp_tpa));
420 refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
422 if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4))
425 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
429 send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
432 static void recv_packet(struct uloop_fd *fd, unsigned int events)
434 struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
435 struct arp_packet *pkt;
436 static char pktbuf[4096];
443 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
454 pkt = (void *)pktbuf;
455 if (pkt->arp.arp_op == htons(ARPOP_REPLY))
456 recv_arp_reply(rif, pkt);
457 else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
458 recv_arp_request(rif, pkt);
460 DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
465 static void forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
467 struct relayd_interface *rif;
468 struct ether_header *eth = packet;
470 list_for_each_entry(rif, &interfaces, list) {
474 DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
475 memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
476 send(rif->bcast_fd.fd, packet, len, 0);
481 chksum(uint16_t sum, const uint8_t *data, uint16_t len)
486 last = data + len - 1;
489 t = (data[0] << 8) + data[1];
497 t = (data[0] << 8) + 0;
506 static bool forward_dhcp_packet(struct relayd_interface *rif, void *data, int len)
508 struct ip_packet *pkt = data;
510 struct dhcp_header *dhcp;
514 if (pkt->eth.ether_type != htons(ETH_P_IP))
517 if (pkt->iph.version != 4)
520 if (pkt->iph.protocol != IPPROTO_UDP)
523 udp = (void *) ((char *) &pkt->iph + (pkt->iph.ihl << 2));
524 dhcp = (void *) (udp + 1);
526 udplen = ntohs(udp->len);
527 if (udplen > len - ((char *) udp - (char *) data))
530 if (udp->dest != htons(67) && udp->source != htons(67))
533 if (dhcp->op != 1 && dhcp->op != 2)
539 DPRINTF(2, "%s: handling DHCP %s\n", rif->ifname, (dhcp->op == 1 ? "request" : "response"));
541 dhcp->flags |= htons(DHCP_FLAG_BROADCAST);
544 sum = udplen + IPPROTO_UDP;
545 sum = chksum(sum, (void *) &pkt->iph.saddr, 8);
546 sum = chksum(sum, (void *) udp, udplen);
550 udp->check = htons(~sum);
552 forward_bcast_packet(rif, data, len);
557 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
559 struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
560 static char pktbuf[4096];
567 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
578 if (!forward_bcast && !forward_dhcp)
581 if (forward_dhcp_packet(rif, pktbuf, pktlen))
585 forward_bcast_packet(rif, pktbuf, pktlen);
590 static int init_interface(struct relayd_interface *rif)
592 struct sockaddr_ll *sll = &rif->sll;
593 struct sockaddr_in *sin;
596 #ifdef PACKET_RECV_TYPE
597 unsigned int pkt_type;
600 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
606 memset(&ifr, 0, sizeof(ifr));
607 strcpy(ifr.ifr_name, rif->ifname);
609 if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
610 perror("ioctl(SIOCGIFHWADDR)");
614 memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
615 sll->sll_family = AF_PACKET;
616 sll->sll_protocol = htons(ETH_P_ARP);
617 sll->sll_pkttype = PACKET_BROADCAST;
618 sll->sll_hatype = ARPHRD_ETHER;
619 sll->sll_halen = ETH_ALEN;
621 if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
622 perror("ioctl(SIOCGIFINDEX)");
626 sll->sll_ifindex = ifr.ifr_ifindex;
628 if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
629 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
631 sin = (struct sockaddr_in *) &ifr.ifr_addr;
632 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
635 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
636 perror("bind(ETH_P_ARP)");
640 rif->fd.cb = recv_packet;
641 uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
643 if (!forward_bcast && !forward_dhcp)
646 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
650 rif->bcast_fd.fd = fd;
651 rif->bcast_fd.cb = recv_bcast_packet;
653 memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
654 sll = &rif->bcast_sll;
655 sll->sll_protocol = htons(ETH_P_IP);
657 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
658 perror("bind(ETH_P_IP)");
662 #ifdef PACKET_RECV_TYPE
663 pkt_type = (1 << PACKET_BROADCAST);
664 setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
667 uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
671 static int init_interfaces(void)
673 struct relayd_interface *rif;
676 list_for_each_entry(rif, &interfaces, list) {
677 ret = init_interface(rif);
685 static void del_interface(struct relayd_interface *rif)
687 struct relayd_host *host, *htmp;
689 list_for_each_entry_safe(host, htmp, &rif->hosts, list) {
695 static void cleanup_interfaces(void)
697 struct relayd_interface *rif, *rtmp;
699 list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
704 static int alloc_interface(const char *ifname, bool managed)
706 struct relayd_interface *rif;
708 if (strlen(ifname) >= IFNAMSIZ)
711 rif = calloc(1, sizeof(*rif));
715 INIT_LIST_HEAD(&rif->list);
716 INIT_LIST_HEAD(&rif->hosts);
717 strcpy(rif->ifname, ifname);
718 list_add(&rif->list, &interfaces);
719 rif->managed = managed;
726 ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
729 static void rtnl_parse_newneigh(struct nlmsghdr *h)
731 struct relayd_interface *rif = NULL;
732 struct ndmsg *r = NLMSG_DATA(h);
733 const uint8_t *lladdr = NULL;
734 const uint8_t *ipaddr = NULL;
738 if (r->ndm_family != AF_INET)
741 list_for_each_entry(rif, &interfaces, list) {
742 if (rif->sll.sll_ifindex == r->ndm_ifindex)
743 goto found_interface;
748 len = h->nlmsg_len - NLMSG_LENGTH(sizeof(*r));
749 for (rta = NDA_RTA(r); RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) {
750 switch(rta->rta_type) {
752 lladdr = RTA_DATA(rta);
755 ipaddr = RTA_DATA(rta);
762 if (!lladdr || !ipaddr || (r->ndm_state & (NUD_INCOMPLETE|NUD_FAILED)))
765 if (!memcmp(lladdr, "\x00\x00\x00\x00\x00\x00", ETH_ALEN))
768 DPRINTF(1, "%s: Found ARP cache entry for host "IP_FMT" ("MAC_FMT")\n",
769 rif->ifname, IP_BUF(ipaddr), MAC_BUF(lladdr));
770 refresh_host(rif, lladdr, ipaddr);
773 static void rtnl_parse_packet(void *data, int len)
777 for (h = data; NLMSG_OK(h, len); h = NLMSG_NEXT(h, len)) {
778 if (h->nlmsg_type == NLMSG_DONE ||
779 h->nlmsg_type == NLMSG_ERROR)
782 if (h->nlmsg_seq != rtnl_dump_seq)
785 if (h->nlmsg_type == RTM_NEWNEIGH)
786 rtnl_parse_newneigh(h);
790 static void rtnl_cb(struct uloop_fd *fd, unsigned int events)
792 struct sockaddr_nl nladdr;
793 static uint8_t buf[16384];
796 .iov_len = sizeof(buf),
798 struct msghdr msg = {
800 .msg_namelen = sizeof(nladdr),
808 len = recvmsg(rtnl_sock.fd, &msg, 0);
819 if (nladdr.nl_pid != 0)
822 rtnl_parse_packet(buf, len);
826 static int rtnl_init(void)
828 struct sockaddr_nl snl_local;
834 .nlmsg_len = sizeof(req),
835 .nlmsg_type = RTM_GETNEIGH,
836 .nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST,
839 .g.rtgen_family = AF_INET,
842 rtnl_sock.fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
843 if (rtnl_sock.fd < 0) {
844 perror("socket(AF_NETLINK)");
848 snl_local.nl_family = AF_NETLINK;
850 if (bind(rtnl_sock.fd, (struct sockaddr *) &snl_local, sizeof(struct sockaddr_nl)) < 0) {
856 rtnl_sock.cb = rtnl_cb;
857 uloop_fd_add(&rtnl_sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
859 rtnl_seq = time(NULL);
860 rtnl_dump_seq = rtnl_seq;
861 req.nlh.nlmsg_seq = rtnl_seq;
862 send(rtnl_sock.fd, &req, sizeof(req), 0);
867 static void die(int signo)
870 * When we hit SIGTERM, clean up interfaces directly, so that we
871 * won't leave our routing in an invalid state.
873 cleanup_interfaces();
877 static int usage(const char *progname)
879 fprintf(stderr, "Usage: %s <options>\n"
882 " -d Enable debug messages\n"
883 " -i <ifname> Add an interface for relaying\n"
884 " -I <ifname> Same as -i, except with ARP cache and host route management\n"
885 " You need to specify at least two interfaces\n"
886 " -t <timeout> Host entry expiry timeout\n"
887 " -B Enable broadcast forwarding\n"
888 " -D Enable DHCP forwarding\n"
894 int main(int argc, char **argv)
901 inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
903 perror("socket(AF_INET)");
911 while ((ch = getopt(argc, argv, "I:i:t:BDd")) != -1) {
918 if (alloc_interface(optarg, managed) < 0)
924 host_timeout = atoi(optarg);
925 if (host_timeout <= 0)
926 return usage(argv[0]);
939 return usage(argv[0]);
943 if (list_empty(&interfaces))
944 return usage(argv[0]);
947 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
954 signal(SIGTERM, die);
956 signal(SIGUSR1, die);
957 signal(SIGUSR2, die);
959 if (init_interfaces() < 0)
968 cleanup_interfaces();
969 uloop_fd_delete(&rtnl_sock);