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 uint8_t local_addr[4];
44 int local_route_table;
46 struct relayd_pending_route {
47 struct relayd_route rt;
48 struct uloop_timeout timeout;
52 static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
54 struct relayd_host *host;
57 list_for_each_entry(rif, &interfaces, list) {
58 host = find_host_by_ipaddr(rif, ipaddr);
67 list_for_each_entry(host, &rif->hosts, list) {
68 if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
76 static void add_arp(struct relayd_host *host)
78 struct sockaddr_in *sin;
81 strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
82 arp.arp_flags = ATF_COM;
84 arp.arp_ha.sa_family = ARPHRD_ETHER;
85 memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);
87 sin = (struct sockaddr_in *) &arp.arp_pa;
88 sin->sin_family = AF_INET;
89 memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));
91 ioctl(inet_sock, SIOCSARP, &arp);
94 static void timeout_host_route(struct uloop_timeout *timeout)
96 struct relayd_pending_route *rt;
98 rt = container_of(timeout, struct relayd_pending_route, timeout);
99 list_del(&rt->rt.list);
103 void relayd_add_host_route(struct relayd_host *host, const uint8_t *dest, uint8_t mask)
105 struct relayd_route *rt;
107 list_for_each_entry(rt, &host->routes, list) {
108 if (!memcmp(rt->dest, dest, sizeof(rt->dest)) && rt->mask == mask)
112 rt = calloc(1, sizeof(*rt));
116 list_add(&rt->list, &host->routes);
117 memcpy(rt->dest, dest, sizeof(rt->dest));
119 relayd_add_route(host, rt);
122 static void del_host(struct relayd_host *host)
124 struct relayd_route *route, *tmp;
126 DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
127 IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));
129 list_for_each_entry_safe(route, tmp, &host->routes, list) {
130 relayd_del_route(host, route);
131 list_del(&route->list);
134 if (host->rif->managed)
135 relayd_del_route(host, NULL);
136 uloop_timeout_cancel(&host->timeout);
137 list_del(&host->list);
141 static void fill_arp_request(struct arp_packet *pkt, struct relayd_interface *rif,
142 const uint8_t spa[4], const uint8_t tpa[4])
144 memset(pkt, 0, sizeof(*pkt));
146 pkt->eth.ether_type = htons(ETHERTYPE_ARP);
147 memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
149 memcpy(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
150 memcpy(pkt->arp.arp_spa, spa, 4);
151 memcpy(pkt->arp.arp_tpa, tpa, 4);
153 pkt->arp.arp_hrd = htons(ARPHRD_ETHER);
154 pkt->arp.arp_pro = htons(ETH_P_IP);
155 pkt->arp.arp_hln = ETH_ALEN;
156 pkt->arp.arp_pln = 4;
159 static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr)
161 struct arp_packet pkt;
163 fill_arp_request(&pkt, rif, rif->src_ip, ipaddr);
165 pkt.arp.arp_op = htons(ARPOP_REQUEST);
166 memcpy(pkt.arp.arp_spa, rif->src_ip, ETH_ALEN);
167 memset(pkt.arp.arp_tha, 0, ETH_ALEN);
168 memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
170 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
171 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
172 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
174 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
175 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
178 void relayd_add_pending_route(const uint8_t *gateway, const uint8_t *dest, uint8_t mask, int timeout)
180 struct relayd_pending_route *rt;
181 struct relayd_interface *rif;
182 struct relayd_host *host;
184 host = find_host_by_ipaddr(NULL, gateway);
186 relayd_add_host_route(host, dest, mask);
190 rt = calloc(1, sizeof(*rt));
194 memcpy(rt->gateway, gateway, sizeof(rt->gateway));
195 memcpy(rt->rt.dest, dest, sizeof(rt->rt.dest));
197 list_add(&rt->rt.list, &pending_routes);
201 rt->timeout.cb = timeout_host_route;
202 uloop_timeout_set(&rt->timeout, 10000);
203 list_for_each_entry(rif, &interfaces, list) {
204 send_arp_request(rif, gateway);
208 static void send_arp_reply(struct relayd_interface *rif, uint8_t spa[4],
209 uint8_t tha[ETH_ALEN], uint8_t tpa[4])
211 struct arp_packet pkt;
213 fill_arp_request(&pkt, rif, spa, tpa);
215 pkt.arp.arp_op = htons(ARPOP_REPLY);
216 memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
217 memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);
219 DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
220 rif->ifname, IP_BUF(pkt.arp.arp_tpa),
221 IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
223 sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
224 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
227 static void host_entry_timeout(struct uloop_timeout *timeout)
229 struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
232 * When a host is behind a managed interface, we must not expire its host
233 * entry prematurely, as this will cause routes to the node to expire,
234 * leading to loss of connectivity from the other side.
235 * When the timeout is reached, try pinging the host a few times before
238 if (host->rif->managed && host->cleanup_pending < 2) {
239 send_arp_request(host->rif, host->ipaddr);
240 host->cleanup_pending++;
241 uloop_timeout_set(&host->timeout, 1000);
247 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
249 struct relayd_host *host;
250 struct relayd_pending_route *route, *rtmp;
252 DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
253 IP_BUF(ipaddr), MAC_BUF(lladdr));
255 host = calloc(1, sizeof(*host));
256 INIT_LIST_HEAD(&host->routes);
258 memcpy(host->ipaddr, ipaddr, sizeof(host->ipaddr));
259 memcpy(host->lladdr, lladdr, sizeof(host->lladdr));
260 list_add(&host->list, &rif->hosts);
261 host->timeout.cb = host_entry_timeout;
262 uloop_timeout_set(&host->timeout, host_timeout * 1000);
266 relayd_add_route(host, NULL);
268 list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
269 if (memcmp(route->gateway, ipaddr, 4) != 0)
272 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
273 if (!route->timeout.pending)
276 uloop_timeout_cancel(&route->timeout);
277 list_del(&route->rt.list);
284 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
286 struct relayd_host *host;
288 host = find_host_by_ipaddr(rif, ipaddr);
290 host = find_host_by_ipaddr(NULL, ipaddr);
293 * When we suddenly see the host appearing on a different interface,
294 * reduce the timeout to make the old entry expire faster, in case the
296 * If the old entry is behind a managed interface, it will be pinged
297 * before we expire it
299 if (host && !host->cleanup_pending) {
300 uloop_timeout_set(&host->timeout, 1);
304 host = add_host(rif, lladdr, ipaddr);
306 host->cleanup_pending = false;
307 uloop_timeout_set(&host->timeout, host_timeout * 1000);
313 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
315 struct relayd_interface *rif;
316 struct arp_packet reqpkt;
318 memcpy(&reqpkt, pkt, sizeof(reqpkt));
319 list_for_each_entry(rif, &interfaces, list) {
323 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
324 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
326 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
327 rif->ifname, IP_BUF(reqpkt.arp.arp_tpa),
328 IP_BUF(reqpkt.arp.arp_spa), MAC_BUF(reqpkt.eth.ether_shost));
330 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
331 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
335 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
337 struct relayd_host *host;
339 DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
341 IP_BUF(pkt->arp.arp_tpa),
342 IP_BUF(pkt->arp.arp_spa),
343 MAC_BUF(pkt->eth.ether_shost));
345 if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
348 if (local_route_table && !memcmp(pkt->arp.arp_tpa, local_addr, sizeof(local_addr))) {
349 send_arp_reply(rif, local_addr, pkt->arp.arp_sha, pkt->arp.arp_spa);
353 relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
355 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
358 * If a host is being pinged because of a timeout, do not use the cached
359 * entry here. That way we can avoid giving out stale data in case the node
360 * has moved. We shouldn't relay requests here either, as we might miss our
361 * chance to create a host route.
363 if (host && host->cleanup_pending)
366 relay_arp_request(rif, pkt);
370 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
372 struct relayd_host *host;
374 DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
376 IP_BUF(pkt->arp.arp_spa),
377 MAC_BUF(pkt->eth.ether_shost),
378 IP_BUF(pkt->arp.arp_tpa));
380 if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
381 relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
383 if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4))
386 host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
390 if (host->rif == rif)
393 send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
396 static void recv_packet(struct uloop_fd *fd, unsigned int events)
398 struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
399 struct arp_packet *pkt;
400 static char pktbuf[4096];
407 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
418 pkt = (void *)pktbuf;
419 if (pkt->arp.arp_op == htons(ARPOP_REPLY))
420 recv_arp_reply(rif, pkt);
421 else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
422 recv_arp_request(rif, pkt);
424 DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
429 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
431 struct relayd_interface *rif;
432 struct ether_header *eth = packet;
434 list_for_each_entry(rif, &interfaces, list) {
438 DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
439 memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
440 send(rif->bcast_fd.fd, packet, len, 0);
444 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
446 struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
447 static char pktbuf[4096];
454 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
465 if (!forward_bcast && !forward_dhcp)
468 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
472 relayd_forward_bcast_packet(rif, pktbuf, pktlen);
477 static int init_interface(struct relayd_interface *rif)
479 struct sockaddr_ll *sll = &rif->sll;
480 struct sockaddr_in *sin;
483 #ifdef PACKET_RECV_TYPE
484 unsigned int pkt_type;
487 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
493 memset(&ifr, 0, sizeof(ifr));
494 strcpy(ifr.ifr_name, rif->ifname);
496 if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
497 perror("ioctl(SIOCGIFHWADDR)");
501 memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
502 sll->sll_family = AF_PACKET;
503 sll->sll_protocol = htons(ETH_P_ARP);
504 sll->sll_pkttype = PACKET_BROADCAST;
505 sll->sll_hatype = ARPHRD_ETHER;
506 sll->sll_halen = ETH_ALEN;
508 if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
509 perror("ioctl(SIOCGIFINDEX)");
513 sll->sll_ifindex = ifr.ifr_ifindex;
515 if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
516 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
518 sin = (struct sockaddr_in *) &ifr.ifr_addr;
519 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
522 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
523 perror("bind(ETH_P_ARP)");
527 rif->fd.cb = recv_packet;
528 uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
530 if (!forward_bcast && !forward_dhcp)
533 fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
537 rif->bcast_fd.fd = fd;
538 rif->bcast_fd.cb = recv_bcast_packet;
540 memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
541 sll = &rif->bcast_sll;
542 sll->sll_protocol = htons(ETH_P_IP);
544 if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
545 perror("bind(ETH_P_IP)");
549 #ifdef PACKET_RECV_TYPE
550 pkt_type = (1 << PACKET_BROADCAST);
551 setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
554 uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
555 relayd_add_interface_routes(rif);
559 static void ping_static_routes(void)
561 struct relayd_pending_route *rt;
562 struct relayd_interface *rif;
564 list_for_each_entry(rt, &pending_routes, rt.list)
565 list_for_each_entry(rif, &interfaces, list)
566 send_arp_request(rif, rt->gateway);
569 static int init_interfaces(void)
571 struct relayd_interface *rif;
574 list_for_each_entry(rif, &interfaces, list) {
575 ret = init_interface(rif);
583 static void cleanup_hosts(void)
585 struct relayd_interface *rif;
586 struct relayd_host *host, *tmp;
588 list_for_each_entry(rif, &interfaces, list) {
589 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
595 static void free_interfaces(void)
597 struct relayd_interface *rif, *rtmp;
599 list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
600 relayd_del_interface_routes(rif);
601 list_del(&rif->list);
606 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
608 struct relayd_interface *rif;
610 if (strlen(ifname) >= IFNAMSIZ)
613 rif = calloc(1, sizeof(*rif));
617 INIT_LIST_HEAD(&rif->hosts);
618 strcpy(rif->ifname, ifname);
619 list_add(&rif->list, &interfaces);
620 rif->managed = managed;
625 static void die(int signo)
628 * When we hit SIGTERM, clean up interfaces directly, so that we
629 * won't leave our routing in an invalid state.
636 static int usage(const char *progname)
638 fprintf(stderr, "Usage: %s <options>\n"
641 " -d Enable debug messages\n"
642 " -i <ifname> Add an interface for relaying\n"
643 " -I <ifname> Same as -i, except with ARP cache and host route management\n"
644 " You need to specify at least two interfaces\n"
645 " -G <ip> Set a gateway IP for clients\n"
646 " -R <gateway>:<net>/<mask>\n"
647 " Add a static route for <net>/<mask> via <gateway>\n"
648 " -t <timeout> Host entry expiry timeout\n"
649 " -T <table> Set routing table number for automatically added routes\n"
650 " -B Enable broadcast forwarding\n"
651 " -D Enable DHCP forwarding\n"
652 " -L <ipaddr> Enable local access using <ipaddr> as source address\n"
658 int main(int argc, char **argv)
660 struct relayd_interface *rif = NULL;
661 struct in_addr addr, addr2;
662 bool local_addr_valid = false;
670 inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
672 perror("socket(AF_INET)");
678 local_route_table = 0;
681 while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:L:")) != -1) {
688 rif = alloc_interface(optarg, managed);
695 host_timeout = atoi(optarg);
696 if (host_timeout <= 0)
697 return usage(argv[0]);
709 route_table = atoi(optarg);
710 if (route_table <= 0)
711 return usage(argv[0]);
714 if (!inet_aton(optarg, &addr)) {
715 fprintf(stderr, "Address '%s' not found\n", optarg);
718 relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
721 if (!inet_aton(optarg, &addr)) {
722 fprintf(stderr, "Address '%s' not found\n", optarg);
725 memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
726 local_addr_valid = true;
729 s = strchr(optarg, ':');
731 return usage(argv[0]);
734 if (!inet_aton(optarg, &addr)) {
735 fprintf(stderr, "Address '%s' not found\n", optarg);
741 return usage(argv[0]);
744 if (!inet_aton(s, &addr2)) {
745 fprintf(stderr, "Address '%s' not found\n", s);
750 if (mask < 0 || mask > 32)
751 return usage(argv[0]);
753 relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
757 return usage(argv[0]);
761 if (list_empty(&interfaces))
762 return usage(argv[0]);
765 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
772 signal(SIGTERM, die);
774 signal(SIGUSR1, die);
775 signal(SIGUSR2, die);
777 if (local_addr_valid)
778 local_route_table = route_table++;
780 if (relayd_rtnl_init() < 0)
783 if (init_interfaces() < 0)
786 ping_static_routes();