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>
19 #include <sys/socket.h>
34 static LIST_HEAD(pending_routes);
35 LIST_HEAD(interfaces);
38 static int host_timeout;
39 static int host_ping_tries;
41 static int forward_bcast;
42 static int forward_dhcp;
44 uint8_t local_addr[4];
45 int local_route_table;
47 struct relayd_pending_route {
48 struct relayd_route rt;
49 struct uloop_timeout timeout;
53 static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
55 struct relayd_host *host;
58 list_for_each_entry(rif, &interfaces, list) {
59 host = find_host_by_ipaddr(rif, ipaddr);
68 list_for_each_entry(host, &rif->hosts, list) {
69 if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
77 static void add_arp(struct relayd_host *host)
79 struct sockaddr_in *sin;
82 strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
83 arp.arp_flags = ATF_COM;
85 arp.arp_ha.sa_family = ARPHRD_ETHER;
86 memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);
88 sin = (struct sockaddr_in *) &arp.arp_pa;
89 sin->sin_family = AF_INET;
90 memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));
92 ioctl(inet_sock, SIOCSARP, &arp);
95 static void timeout_host_route(struct uloop_timeout *timeout)
97 struct relayd_pending_route *rt;
99 rt = container_of(timeout, struct relayd_pending_route, timeout);
100 list_del(&rt->rt.list);
104 void relayd_add_host_route(struct relayd_host *host, const uint8_t *dest, uint8_t mask)
106 struct relayd_route *rt;
108 list_for_each_entry(rt, &host->routes, list) {
109 if (!memcmp(rt->dest, dest, sizeof(rt->dest)) && rt->mask == mask)
113 rt = calloc(1, sizeof(*rt));
117 list_add(&rt->list, &host->routes);
118 memcpy(rt->dest, dest, sizeof(rt->dest));
120 relayd_add_route(host, rt);
123 static void del_host(struct relayd_host *host)
125 struct relayd_route *route, *tmp;
127 DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
128 IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));
130 list_for_each_entry_safe(route, tmp, &host->routes, list) {
131 relayd_del_route(host, route);
132 list_del(&route->list);
135 if (host->rif->managed)
136 relayd_del_route(host, NULL);
137 uloop_timeout_cancel(&host->timeout);
138 list_del(&host->list);
142 static void fill_arp_packet(struct arp_packet *pkt, struct relayd_interface *rif,
143 const uint8_t spa[4], const uint8_t tpa[4])
145 memset(pkt, 0, sizeof(*pkt));
147 pkt->eth.ether_type = htons(ETHERTYPE_ARP);
148 memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
150 memcpy(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
151 memcpy(pkt->arp.arp_spa, spa, 4);
152 memcpy(pkt->arp.arp_tpa, tpa, 4);
154 pkt->arp.arp_hrd = htons(ARPHRD_ETHER);
155 pkt->arp.arp_pro = htons(ETH_P_IP);
156 pkt->arp.arp_hln = ETH_ALEN;
157 pkt->arp.arp_pln = 4;
160 static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr)
162 struct arp_packet pkt;
164 fill_arp_packet(&pkt, rif, rif->src_ip, ipaddr);
166 pkt.arp.arp_op = htons(ARPOP_REQUEST);
167 memcpy(pkt.arp.arp_spa, rif->src_ip, ETH_ALEN);
168 memset(pkt.arp.arp_tha, 0, ETH_ALEN);
169 memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
171 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
172 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
173 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
175 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
176 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
179 void relayd_add_pending_route(const uint8_t *gateway, const uint8_t *dest, uint8_t mask, int timeout)
181 struct relayd_pending_route *rt;
182 struct relayd_interface *rif;
183 struct relayd_host *host;
185 host = find_host_by_ipaddr(NULL, gateway);
187 relayd_add_host_route(host, dest, mask);
191 rt = calloc(1, sizeof(*rt));
195 memcpy(rt->gateway, gateway, sizeof(rt->gateway));
196 memcpy(rt->rt.dest, dest, sizeof(rt->rt.dest));
198 list_add(&rt->rt.list, &pending_routes);
202 rt->timeout.cb = timeout_host_route;
203 uloop_timeout_set(&rt->timeout, 10000);
204 list_for_each_entry(rif, &interfaces, list) {
205 send_arp_request(rif, gateway);
209 static void send_arp_reply(struct relayd_interface *rif, const uint8_t spa[4],
210 const uint8_t tha[ETH_ALEN], const uint8_t tpa[4])
212 struct arp_packet pkt;
214 fill_arp_packet(&pkt, rif, spa, tpa);
217 pkt.arp.arp_op = htons(ARPOP_REPLY);
218 memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
219 memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);
221 DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
222 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
223 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
225 pkt.arp.arp_op = htons(ARPOP_REQUEST);
226 memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
227 memset(pkt.arp.arp_tha, 0xff, ETH_ALEN);
229 DPRINTF(2, "%s: sending gratuitous ARP: "IP_FMT" is at ("MAC_FMT")\n",
230 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
231 MAC_BUF(pkt.eth.ether_shost));
234 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
235 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
241 * Gratuitous ARP comes in two flavours, request and reply.
242 * Some operating systems only accept request, some only reply.
243 * Let's just send both...
245 pkt.arp.arp_op = htons(ARPOP_REPLY);
247 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
248 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
252 static void host_entry_timeout(struct uloop_timeout *timeout)
254 struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
257 * When a host is behind a managed interface, we must not expire its host
258 * entry prematurely, as this will cause routes to the node to expire,
259 * leading to loss of connectivity from the other side.
260 * When the timeout is reached, try pinging the host a few times before
263 if (host->rif->managed && host->cleanup_pending < host_ping_tries) {
264 send_arp_request(host->rif, host->ipaddr);
265 host->cleanup_pending++;
266 uloop_timeout_set(&host->timeout, 1000);
272 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
274 struct relayd_host *host;
275 struct relayd_pending_route *route, *rtmp;
277 DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
278 IP_BUF(ipaddr), MAC_BUF(lladdr));
280 host = calloc(1, sizeof(*host));
281 INIT_LIST_HEAD(&host->routes);
283 memcpy(host->ipaddr, ipaddr, sizeof(host->ipaddr));
284 memcpy(host->lladdr, lladdr, sizeof(host->lladdr));
285 list_add(&host->list, &rif->hosts);
286 host->timeout.cb = host_entry_timeout;
287 uloop_timeout_set(&host->timeout, host_timeout * 1000);
291 relayd_add_route(host, NULL);
293 list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
294 if (memcmp(route->gateway, ipaddr, 4) != 0)
297 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
298 if (!route->timeout.pending)
301 uloop_timeout_cancel(&route->timeout);
302 list_del(&route->rt.list);
309 static void send_gratuitous_arp(struct relayd_interface *rif, const uint8_t *spa)
311 struct relayd_interface *to_rif;
313 list_for_each_entry(to_rif, &interfaces, list) {
317 send_arp_reply(to_rif, spa, NULL, spa);
322 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
324 struct relayd_host *host;
326 host = find_host_by_ipaddr(rif, ipaddr);
328 host = find_host_by_ipaddr(NULL, ipaddr);
331 * When we suddenly see the host appearing on a different interface,
332 * reduce the timeout to make the old entry expire faster, in case the
334 * If the old entry is behind a managed interface, it will be pinged
335 * before we expire it
337 if (host && !host->cleanup_pending) {
338 uloop_timeout_set(&host->timeout, 1);
342 host = add_host(rif, lladdr, ipaddr);
344 host->cleanup_pending = false;
345 uloop_timeout_set(&host->timeout, host_timeout * 1000);
346 send_gratuitous_arp(rif, ipaddr);
352 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
354 struct relayd_interface *rif;
355 struct arp_packet reqpkt;
357 memcpy(&reqpkt, pkt, sizeof(reqpkt));
358 list_for_each_entry(rif, &interfaces, list) {
362 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
363 memset(reqpkt.eth.ether_dhost, 0xff, ETH_ALEN);
364 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
365 memset(reqpkt.arp.arp_tha, 0, ETH_ALEN);
367 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
368 rif->ifname, IP_BUF(reqpkt.arp.arp_tpa),
369 IP_BUF(reqpkt.arp.arp_spa), MAC_BUF(reqpkt.eth.ether_shost));
371 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
372 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
376 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
378 struct relayd_host *host;
380 DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
382 IP_BUF(pkt->arp.arp_tpa),
383 IP_BUF(pkt->arp.arp_spa),
384 MAC_BUF(pkt->eth.ether_shost));
386 if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
389 host = find_host_by_ipaddr(NULL, pkt->arp.arp_spa);
390 if (!host || host->rif != rif)
391 relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
393 if (local_route_table && !memcmp(pkt->arp.arp_tpa, local_addr, sizeof(local_addr))) {
394 send_arp_reply(rif, local_addr, pkt->arp.arp_sha, pkt->arp.arp_spa);
398 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
401 * If a host is being pinged because of a timeout, do not use the cached
402 * entry here. That way we can avoid giving out stale data in case the node
403 * has moved. We shouldn't relay requests here either, as we might miss our
404 * chance to create a host route.
406 if (host && host->cleanup_pending)
409 relay_arp_request(rif, pkt);
412 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
414 struct relayd_host *host;
416 DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
418 IP_BUF(pkt->arp.arp_spa),
419 MAC_BUF(pkt->eth.ether_shost),
420 IP_BUF(pkt->arp.arp_tpa));
422 if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
423 relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
425 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
429 if (host->rif == rif)
432 send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
435 static void recv_packet(struct uloop_fd *fd, unsigned int events)
437 struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
438 struct arp_packet *pkt;
439 static char pktbuf[4096];
446 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
457 pkt = (void *)pktbuf;
458 if (pkt->arp.arp_op == htons(ARPOP_REPLY))
459 recv_arp_reply(rif, pkt);
460 else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
461 recv_arp_request(rif, pkt);
463 DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
468 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
470 struct relayd_interface *rif;
471 struct ether_header *eth = packet;
473 list_for_each_entry(rif, &interfaces, list) {
477 DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
478 memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
479 send(rif->bcast_fd.fd, packet, len, 0);
483 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
485 struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
486 static char pktbuf[4096];
493 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
504 if (!forward_bcast && !forward_dhcp)
507 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
511 relayd_forward_bcast_packet(rif, pktbuf, pktlen);
516 static int init_interface(struct relayd_interface *rif)
518 struct sockaddr_ll *sll = &rif->sll;
519 struct sockaddr_in *sin;
522 #ifdef PACKET_RECV_TYPE
523 unsigned int pkt_type;
526 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
532 memset(&ifr, 0, sizeof(ifr));
533 strcpy(ifr.ifr_name, rif->ifname);
535 if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
536 perror("ioctl(SIOCGIFHWADDR)");
540 memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
541 sll->sll_family = AF_PACKET;
542 sll->sll_protocol = htons(ETH_P_ARP);
543 sll->sll_pkttype = PACKET_BROADCAST;
544 sll->sll_hatype = ARPHRD_ETHER;
545 sll->sll_halen = ETH_ALEN;
547 if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
548 perror("ioctl(SIOCGIFINDEX)");
552 sll->sll_ifindex = ifr.ifr_ifindex;
554 if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
555 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
557 sin = (struct sockaddr_in *) &ifr.ifr_addr;
558 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
561 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
562 perror("bind(ETH_P_ARP)");
566 rif->fd.cb = recv_packet;
567 uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
569 if (!forward_bcast && !forward_dhcp)
572 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
576 rif->bcast_fd.fd = fd;
577 rif->bcast_fd.cb = recv_bcast_packet;
579 memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
580 sll = &rif->bcast_sll;
581 sll->sll_protocol = htons(ETH_P_IP);
583 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
584 perror("bind(ETH_P_IP)");
588 #ifdef PACKET_RECV_TYPE
589 pkt_type = (1 << PACKET_BROADCAST) | (1 << PACKET_MULTICAST);
590 setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
593 uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
594 relayd_add_interface_routes(rif);
598 static void ping_static_routes(void)
600 struct relayd_pending_route *rt;
601 struct relayd_interface *rif;
603 list_for_each_entry(rt, &pending_routes, rt.list)
604 list_for_each_entry(rif, &interfaces, list)
605 send_arp_request(rif, rt->gateway);
608 static int init_interfaces(void)
610 struct relayd_interface *rif;
613 list_for_each_entry(rif, &interfaces, list) {
614 ret = init_interface(rif);
622 static void cleanup_hosts(void)
624 struct relayd_interface *rif;
625 struct relayd_host *host, *tmp;
627 list_for_each_entry(rif, &interfaces, list) {
628 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
634 static void free_interfaces(void)
636 struct relayd_interface *rif, *rtmp;
638 list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
639 relayd_del_interface_routes(rif);
640 list_del(&rif->list);
645 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
647 struct relayd_interface *rif;
649 if (strlen(ifname) >= IFNAMSIZ)
652 rif = calloc(1, sizeof(*rif));
656 INIT_LIST_HEAD(&rif->hosts);
657 strcpy(rif->ifname, ifname);
658 list_add(&rif->list, &interfaces);
659 rif->managed = managed;
664 static void die(int signo)
667 * When we hit SIGTERM, clean up interfaces directly, so that we
668 * won't leave our routing in an invalid state.
675 static int usage(const char *progname)
677 fprintf(stderr, "Usage: %s <options>\n"
680 " -d Enable debug messages\n"
681 " -i <ifname> Add an interface for relaying\n"
682 " -I <ifname> Same as -i, except with ARP cache and host route management\n"
683 " You need to specify at least two interfaces\n"
684 " -G <ip> Set a gateway IP for clients\n"
685 " -R <gateway>:<net>/<mask>\n"
686 " Add a static route for <net>/<mask> via <gateway>\n"
687 " -t <timeout> Host entry expiry timeout\n"
688 " -p <tries> Number of ARP ping attempts before considering a host dead\n"
689 " -T <table> Set routing table number for automatically added routes\n"
690 " -B Enable broadcast forwarding\n"
691 " -D Enable DHCP forwarding\n"
692 " -L <ipaddr> Enable local access using <ipaddr> as source address\n"
698 int main(int argc, char **argv)
700 struct relayd_interface *rif = NULL;
701 struct in_addr addr, addr2;
702 bool local_addr_valid = false;
710 inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
712 perror("socket(AF_INET)");
719 local_route_table = 0;
722 while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:L:")) != -1) {
729 rif = alloc_interface(optarg, managed);
736 host_timeout = atoi(optarg);
737 if (host_timeout <= 0)
738 return usage(argv[0]);
741 host_ping_tries = atoi(optarg);
742 if (host_ping_tries <= 0)
743 return usage(argv[0]);
755 route_table = atoi(optarg);
756 if (route_table <= 0)
757 return usage(argv[0]);
760 if (!inet_aton(optarg, &addr)) {
761 fprintf(stderr, "Address '%s' not found\n", optarg);
764 relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
767 if (!inet_aton(optarg, &addr)) {
768 fprintf(stderr, "Address '%s' not found\n", optarg);
771 memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
772 local_addr_valid = true;
775 s = strchr(optarg, ':');
777 return usage(argv[0]);
780 if (!inet_aton(optarg, &addr)) {
781 fprintf(stderr, "Address '%s' not found\n", optarg);
787 return usage(argv[0]);
790 if (!inet_aton(s, &addr2)) {
791 fprintf(stderr, "Address '%s' not found\n", s);
796 if (mask < 0 || mask > 32)
797 return usage(argv[0]);
799 relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
803 return usage(argv[0]);
807 if (list_empty(&interfaces))
808 return usage(argv[0]);
811 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
818 signal(SIGTERM, die);
820 signal(SIGUSR1, die);
821 signal(SIGUSR2, die);
823 if (local_addr_valid)
824 local_route_table = route_table++;
826 if (relayd_rtnl_init() < 0)
829 if (init_interfaces() < 0)
832 ping_static_routes();