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;
40 static int forward_bcast;
41 static int forward_dhcp;
43 struct relayd_pending_route {
44 struct relayd_route rt;
45 struct uloop_timeout timeout;
49 static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
51 struct relayd_host *host;
54 list_for_each_entry(rif, &interfaces, list) {
55 host = find_host_by_ipaddr(rif, ipaddr);
64 list_for_each_entry(host, &rif->hosts, list) {
65 if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
73 static void add_arp(struct relayd_host *host)
75 struct sockaddr_in *sin;
78 strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
79 arp.arp_flags = ATF_COM;
81 arp.arp_ha.sa_family = ARPHRD_ETHER;
82 memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);
84 sin = (struct sockaddr_in *) &arp.arp_pa;
85 sin->sin_family = AF_INET;
86 memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));
88 ioctl(inet_sock, SIOCSARP, &arp);
91 static void timeout_host_route(struct uloop_timeout *timeout)
93 struct relayd_pending_route *rt;
95 rt = container_of(timeout, struct relayd_pending_route, timeout);
96 list_del(&rt->rt.list);
100 void relayd_add_host_route(struct relayd_host *host, const uint8_t *dest, uint8_t mask)
102 struct relayd_route *rt;
104 list_for_each_entry(rt, &host->routes, list) {
105 if (!memcmp(rt->dest, dest, sizeof(rt->dest)) && rt->mask == mask)
109 rt = calloc(1, sizeof(*rt));
113 list_add(&rt->list, &host->routes);
114 memcpy(rt->dest, dest, sizeof(rt->dest));
116 relayd_add_route(host, rt);
119 static void del_host(struct relayd_host *host)
121 struct relayd_route *route, *tmp;
123 DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
124 IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));
126 list_for_each_entry_safe(route, tmp, &host->routes, list) {
127 relayd_del_route(host, route);
128 list_del(&route->list);
131 if (host->rif->managed)
132 relayd_del_route(host, NULL);
133 uloop_timeout_cancel(&host->timeout);
134 list_del(&host->list);
138 static void fill_arp_request(struct arp_packet *pkt, struct relayd_interface *rif,
139 const uint8_t spa[4], const uint8_t tpa[4])
141 memset(pkt, 0, sizeof(*pkt));
143 pkt->eth.ether_type = htons(ETHERTYPE_ARP);
144 memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
146 memcpy(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
147 memcpy(pkt->arp.arp_spa, spa, 4);
148 memcpy(pkt->arp.arp_tpa, tpa, 4);
150 pkt->arp.arp_hrd = htons(ARPHRD_ETHER);
151 pkt->arp.arp_pro = htons(ETH_P_IP);
152 pkt->arp.arp_hln = ETH_ALEN;
153 pkt->arp.arp_pln = 4;
156 static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr)
158 struct arp_packet pkt;
160 fill_arp_request(&pkt, rif, rif->src_ip, ipaddr);
162 pkt.arp.arp_op = htons(ARPOP_REQUEST);
163 memcpy(pkt.arp.arp_spa, rif->src_ip, ETH_ALEN);
164 memset(pkt.arp.arp_tha, 0, ETH_ALEN);
165 memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
167 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
168 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
169 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
171 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
172 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
175 void relayd_add_pending_route(const uint8_t *gateway, const uint8_t *dest, uint8_t mask, int timeout)
177 struct relayd_pending_route *rt;
178 struct relayd_interface *rif;
179 struct relayd_host *host;
181 host = find_host_by_ipaddr(NULL, gateway);
183 relayd_add_host_route(host, dest, mask);
187 rt = calloc(1, sizeof(*rt));
191 memcpy(rt->gateway, gateway, sizeof(rt->gateway));
192 memcpy(rt->rt.dest, dest, sizeof(rt->rt.dest));
194 list_add(&rt->rt.list, &pending_routes);
198 rt->timeout.cb = timeout_host_route;
199 uloop_timeout_set(&rt->timeout, 10000);
200 list_for_each_entry(rif, &interfaces, list) {
201 send_arp_request(rif, gateway);
205 static void send_arp_reply(struct relayd_interface *rif, uint8_t spa[4],
206 uint8_t tha[ETH_ALEN], uint8_t tpa[4])
208 struct arp_packet pkt;
210 fill_arp_request(&pkt, rif, spa, tpa);
212 pkt.arp.arp_op = htons(ARPOP_REPLY);
213 memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
214 memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);
216 DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
217 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
218 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
220 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
221 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
224 static void host_entry_timeout(struct uloop_timeout *timeout)
226 struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
229 * When a host is behind a managed interface, we must not expire its host
230 * entry prematurely, as this will cause routes to the node to expire,
231 * leading to loss of connectivity from the other side.
232 * When the timeout is reached, try pinging the host a few times before
235 if (host->rif->managed && host->cleanup_pending < 2) {
236 send_arp_request(host->rif, host->ipaddr);
237 host->cleanup_pending++;
238 uloop_timeout_set(&host->timeout, 1000);
244 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
246 struct relayd_host *host;
247 struct relayd_pending_route *route, *rtmp;
249 DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
250 IP_BUF(ipaddr), MAC_BUF(lladdr));
252 host = calloc(1, sizeof(*host));
253 INIT_LIST_HEAD(&host->routes);
255 memcpy(host->ipaddr, ipaddr, sizeof(host->ipaddr));
256 memcpy(host->lladdr, lladdr, sizeof(host->lladdr));
257 list_add(&host->list, &rif->hosts);
258 host->timeout.cb = host_entry_timeout;
259 uloop_timeout_set(&host->timeout, host_timeout * 1000);
263 relayd_add_route(host, NULL);
265 list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
266 if (memcmp(route->gateway, ipaddr, 4) != 0)
269 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
270 if (!route->timeout.pending)
273 uloop_timeout_cancel(&route->timeout);
274 list_del(&route->rt.list);
281 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
283 struct relayd_host *host;
285 host = find_host_by_ipaddr(rif, ipaddr);
287 host = find_host_by_ipaddr(NULL, ipaddr);
290 * When we suddenly see the host appearing on a different interface,
291 * reduce the timeout to make the old entry expire faster, in case the
293 * If the old entry is behind a managed interface, it will be pinged
294 * before we expire it
296 if (host && !host->cleanup_pending) {
297 uloop_timeout_set(&host->timeout, 1);
301 host = add_host(rif, lladdr, ipaddr);
303 host->cleanup_pending = false;
304 uloop_timeout_set(&host->timeout, host_timeout * 1000);
310 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
312 struct relayd_interface *rif;
313 struct arp_packet reqpkt;
315 memcpy(&reqpkt, pkt, sizeof(reqpkt));
316 list_for_each_entry(rif, &interfaces, list) {
320 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
321 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
323 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
324 rif->ifname, IP_BUF(reqpkt.arp.arp_tpa),
325 IP_BUF(reqpkt.arp.arp_spa), MAC_BUF(reqpkt.eth.ether_shost));
327 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
328 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
332 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
334 struct relayd_host *host;
336 DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
338 IP_BUF(pkt->arp.arp_tpa),
339 IP_BUF(pkt->arp.arp_spa),
340 MAC_BUF(pkt->eth.ether_shost));
342 if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
345 relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
347 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
350 * If a host is being pinged because of a timeout, do not use the cached
351 * entry here. That way we can avoid giving out stale data in case the node
352 * has moved. We shouldn't relay requests here either, as we might miss our
353 * chance to create a host route.
355 if (host && host->cleanup_pending)
358 relay_arp_request(rif, pkt);
362 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
364 struct relayd_host *host;
366 DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
368 IP_BUF(pkt->arp.arp_spa),
369 MAC_BUF(pkt->eth.ether_shost),
370 IP_BUF(pkt->arp.arp_tpa));
372 if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
373 relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
375 if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4))
378 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
382 if (host->rif == rif)
385 send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
388 static void recv_packet(struct uloop_fd *fd, unsigned int events)
390 struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
391 struct arp_packet *pkt;
392 static char pktbuf[4096];
399 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
410 pkt = (void *)pktbuf;
411 if (pkt->arp.arp_op == htons(ARPOP_REPLY))
412 recv_arp_reply(rif, pkt);
413 else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
414 recv_arp_request(rif, pkt);
416 DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
421 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
423 struct relayd_interface *rif;
424 struct ether_header *eth = packet;
426 list_for_each_entry(rif, &interfaces, list) {
430 DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
431 memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
432 send(rif->bcast_fd.fd, packet, len, 0);
436 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
438 struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
439 static char pktbuf[4096];
446 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
457 if (!forward_bcast && !forward_dhcp)
460 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
464 relayd_forward_bcast_packet(rif, pktbuf, pktlen);
469 static int init_interface(struct relayd_interface *rif)
471 struct sockaddr_ll *sll = &rif->sll;
472 struct sockaddr_in *sin;
475 #ifdef PACKET_RECV_TYPE
476 unsigned int pkt_type;
479 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
485 memset(&ifr, 0, sizeof(ifr));
486 strcpy(ifr.ifr_name, rif->ifname);
488 if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
489 perror("ioctl(SIOCGIFHWADDR)");
493 memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
494 sll->sll_family = AF_PACKET;
495 sll->sll_protocol = htons(ETH_P_ARP);
496 sll->sll_pkttype = PACKET_BROADCAST;
497 sll->sll_hatype = ARPHRD_ETHER;
498 sll->sll_halen = ETH_ALEN;
500 if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
501 perror("ioctl(SIOCGIFINDEX)");
505 sll->sll_ifindex = ifr.ifr_ifindex;
507 if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
508 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
510 sin = (struct sockaddr_in *) &ifr.ifr_addr;
511 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
514 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
515 perror("bind(ETH_P_ARP)");
519 rif->fd.cb = recv_packet;
520 uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
522 if (!forward_bcast && !forward_dhcp)
525 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
529 rif->bcast_fd.fd = fd;
530 rif->bcast_fd.cb = recv_bcast_packet;
532 memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
533 sll = &rif->bcast_sll;
534 sll->sll_protocol = htons(ETH_P_IP);
536 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
537 perror("bind(ETH_P_IP)");
541 #ifdef PACKET_RECV_TYPE
542 pkt_type = (1 << PACKET_BROADCAST);
543 setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
546 uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
547 relayd_add_interface_routes(rif);
551 static void ping_static_routes(void)
553 struct relayd_pending_route *rt;
554 struct relayd_interface *rif;
556 list_for_each_entry(rt, &pending_routes, rt.list)
557 list_for_each_entry(rif, &interfaces, list)
558 send_arp_request(rif, rt->gateway);
561 static int init_interfaces(void)
563 struct relayd_interface *rif;
566 list_for_each_entry(rif, &interfaces, list) {
567 ret = init_interface(rif);
575 static void cleanup_hosts(void)
577 struct relayd_interface *rif;
578 struct relayd_host *host, *tmp;
580 list_for_each_entry(rif, &interfaces, list) {
581 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
587 static void free_interfaces(void)
589 struct relayd_interface *rif, *rtmp;
591 list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
592 relayd_del_interface_routes(rif);
593 list_del(&rif->list);
598 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
600 struct relayd_interface *rif;
602 if (strlen(ifname) >= IFNAMSIZ)
605 rif = calloc(1, sizeof(*rif));
609 INIT_LIST_HEAD(&rif->hosts);
610 strcpy(rif->ifname, ifname);
611 list_add(&rif->list, &interfaces);
612 rif->managed = managed;
617 static void die(int signo)
620 * When we hit SIGTERM, clean up interfaces directly, so that we
621 * won't leave our routing in an invalid state.
628 static int usage(const char *progname)
630 fprintf(stderr, "Usage: %s <options>\n"
633 " -d Enable debug messages\n"
634 " -i <ifname> Add an interface for relaying\n"
635 " -I <ifname> Same as -i, except with ARP cache and host route management\n"
636 " You need to specify at least two interfaces\n"
637 " -G <ip> Set a gateway IP for clients\n"
638 " -R <gateway>:<net>/<mask>\n"
639 " Add a static route for <net>/<mask> via <gateway>\n"
640 " -t <timeout> Host entry expiry timeout\n"
641 " -T <table> Set routing table number for automatically added routes\n"
642 " -B Enable broadcast forwarding\n"
643 " -D Enable DHCP forwarding\n"
649 int main(int argc, char **argv)
651 struct relayd_interface *rif = NULL;
652 struct in_addr addr, addr2;
660 inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
662 perror("socket(AF_INET)");
670 while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:")) != -1) {
677 rif = alloc_interface(optarg, managed);
684 host_timeout = atoi(optarg);
685 if (host_timeout <= 0)
686 return usage(argv[0]);
698 route_table = atoi(optarg);
699 if (route_table <= 0)
700 return usage(argv[0]);
703 if (!inet_aton(optarg, &addr)) {
704 fprintf(stderr, "Address '%s' not found\n", optarg);
707 relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
710 s = strchr(optarg, ':');
712 return usage(argv[0]);
715 if (!inet_aton(optarg, &addr)) {
716 fprintf(stderr, "Address '%s' not found\n", optarg);
722 return usage(argv[0]);
725 if (!inet_aton(s, &addr2)) {
726 fprintf(stderr, "Address '%s' not found\n", s);
731 if (mask < 0 || mask > 32)
732 return usage(argv[0]);
734 relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
738 return usage(argv[0]);
742 if (list_empty(&interfaces))
743 return usage(argv[0]);
746 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
753 signal(SIGTERM, die);
755 signal(SIGUSR1, die);
756 signal(SIGUSR2, die);
758 if (relayd_rtnl_init() < 0)
761 if (init_interfaces() < 0)
764 ping_static_routes();