main.c

   1 /*
   2  *   Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
   3  *
   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.
   7  *
   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.
  12  *
  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.
  16  *
  17  */
  18 #include <sys/ioctl.h>
  19 #include <sys/socket.h>
  20
  21 #include <stdio.h>
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <stddef.h>
  25 #include <stdlib.h>
  26 #include <stdint.h>
  27 #include <stdbool.h>
  28 #include <errno.h>
  29 #include <signal.h>
  30 #include <string.h>
  31
  32 #include "relayd.h"
  33
  34 static LIST_HEAD(pending_routes);
  35 LIST_HEAD(interfaces);
  36 int debug;
  37
  38 static int host_timeout;
  39 static int inet_sock;
  40 static int forward_bcast;
  41 static int forward_dhcp;
  42
  43 uint8_t local_addr[4];
  44 int local_route_table;
  45
  46 struct relayd_pending_route {
  47         struct relayd_route rt;
  48         struct uloop_timeout timeout;
  49         uint8_t gateway[4];
  50 };
  51
  52 static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
  53 {
  54         struct relayd_host *host;
  55
  56         if (!rif) {
  57                 list_for_each_entry(rif, &interfaces, list) {
  58                         host = find_host_by_ipaddr(rif, ipaddr);
  59                         if (!host)
  60                                 continue;
  61
  62                         return host;
  63                 }
  64                 return NULL;
  65         }
  66
  67         list_for_each_entry(host, &rif->hosts, list) {
  68                 if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
  69                         continue;
  70
  71                 return host;
  72         }
  73         return NULL;
  74 }
  75
  76 static void add_arp(struct relayd_host *host)
  77 {
  78         struct sockaddr_in *sin;
  79         struct arpreq arp;
  80
  81         strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
  82         arp.arp_flags = ATF_COM;
  83
  84         arp.arp_ha.sa_family = ARPHRD_ETHER;
  85         memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);
  86
  87         sin = (struct sockaddr_in *) &arp.arp_pa;
  88         sin->sin_family = AF_INET;
  89         memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));
  90
  91         ioctl(inet_sock, SIOCSARP, &arp);
  92 }
  93
  94 static void timeout_host_route(struct uloop_timeout *timeout)
  95 {
  96         struct relayd_pending_route *rt;
  97
  98         rt = container_of(timeout, struct relayd_pending_route, timeout);
  99         list_del(&rt->rt.list);
 100         free(rt);
 101 }
 102
 103 void relayd_add_host_route(struct relayd_host *host, const uint8_t *dest, uint8_t mask)
 104 {
 105         struct relayd_route *rt;
 106
 107         list_for_each_entry(rt, &host->routes, list) {
 108                 if (!memcmp(rt->dest, dest, sizeof(rt->dest)) && rt->mask == mask)
 109                         return;
 110         }
 111
 112         rt = calloc(1, sizeof(*rt));
 113         if (!rt)
 114                 return;
 115
 116         list_add(&rt->list, &host->routes);
 117         memcpy(rt->dest, dest, sizeof(rt->dest));
 118         rt->mask = mask;
 119         relayd_add_route(host, rt);
 120 }
 121
 122 static void del_host(struct relayd_host *host)
 123 {
 124         struct relayd_route *route, *tmp;
 125
 126         DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
 127                 IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));
 128
 129         list_for_each_entry_safe(route, tmp, &host->routes, list) {
 130                 relayd_del_route(host, route);
 131                 list_del(&route->list);
 132                 free(route);
 133         }
 134         if (host->rif->managed)
 135                 relayd_del_route(host, NULL);
 136         uloop_timeout_cancel(&host->timeout);
 137         list_del(&host->list);
 138         free(host);
 139 }
 140
 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])
 143 {
 144         memset(pkt, 0, sizeof(*pkt));
 145
 146         pkt->eth.ether_type = htons(ETHERTYPE_ARP);
 147         memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
 148
 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);
 152
 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;
 157 }
 158
 159 static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr)
 160 {
 161         struct arp_packet pkt;
 162
 163         fill_arp_request(&pkt, rif, rif->src_ip, ipaddr);
 164
 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);
 169
 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));
 173
 174         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 175                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 176 }
 177
 178 void relayd_add_pending_route(const uint8_t *gateway, const uint8_t *dest, uint8_t mask, int timeout)
 179 {
 180         struct relayd_pending_route *rt;
 181         struct relayd_interface *rif;
 182         struct relayd_host *host;
 183
 184         host = find_host_by_ipaddr(NULL, gateway);
 185         if (host) {
 186                 relayd_add_host_route(host, dest, mask);
 187                 return;
 188         }
 189
 190         rt = calloc(1, sizeof(*rt));
 191         if (!rt)
 192                 return;
 193
 194         memcpy(rt->gateway, gateway, sizeof(rt->gateway));
 195         memcpy(rt->rt.dest, dest, sizeof(rt->rt.dest));
 196         rt->rt.mask = mask;
 197         list_add(&rt->rt.list, &pending_routes);
 198         if (timeout <= 0)
 199                 return;
 200
 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);
 205         }
 206 }
 207
 208 static void send_arp_reply(struct relayd_interface *rif, uint8_t spa[4],
 209                            uint8_t tha[ETH_ALEN], uint8_t tpa[4])
 210 {
 211         struct arp_packet pkt;
 212
 213         fill_arp_request(&pkt, rif, spa, tpa);
 214
 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);
 218
 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));
 222
 223         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 224                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 225 }
 226
 227 static void host_entry_timeout(struct uloop_timeout *timeout)
 228 {
 229         struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
 230
 231         /*
 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
 236          * giving up on it.
 237          */
 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);
 242                 return;
 243         }
 244         del_host(host);
 245 }
 246
 247 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 248 {
 249         struct relayd_host *host;
 250         struct relayd_pending_route *route, *rtmp;
 251
 252         DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
 253                         IP_BUF(ipaddr), MAC_BUF(lladdr));
 254
 255         host = calloc(1, sizeof(*host));
 256         INIT_LIST_HEAD(&host->routes);
 257         host->rif = rif;
 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);
 263
 264         add_arp(host);
 265         if (rif->managed)
 266                 relayd_add_route(host, NULL);
 267
 268         list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
 269                 if (memcmp(route->gateway, ipaddr, 4) != 0)
 270                         continue;
 271
 272                 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
 273                 if (!route->timeout.pending)
 274                         continue;
 275
 276                 uloop_timeout_cancel(&route->timeout);
 277                 list_del(&route->rt.list);
 278                 free(route);
 279         }
 280
 281         return host;
 282 }
 283
 284 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 285 {
 286         struct relayd_host *host;
 287
 288         host = find_host_by_ipaddr(rif, ipaddr);
 289         if (!host) {
 290                 host = find_host_by_ipaddr(NULL, ipaddr);
 291
 292                 /*
 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
 295                  * host has moved.
 296                  * If the old entry is behind a managed interface, it will be pinged
 297                  * before we expire it
 298                  */
 299                 if (host && !host->cleanup_pending) {
 300                         uloop_timeout_set(&host->timeout, 1);
 301                         return NULL;
 302                 }
 303
 304                 host = add_host(rif, lladdr, ipaddr);
 305         } else {
 306                 host->cleanup_pending = false;
 307                 uloop_timeout_set(&host->timeout, host_timeout * 1000);
 308         }
 309
 310         return host;
 311 }
 312
 313 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
 314 {
 315         struct relayd_interface *rif;
 316         struct arp_packet reqpkt;
 317
 318         memcpy(&reqpkt, pkt, sizeof(reqpkt));
 319         list_for_each_entry(rif, &interfaces, list) {
 320                 if (rif == from_rif)
 321                         continue;
 322
 323                 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
 324                 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
 325
 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));
 329
 330                 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
 331                         (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 332         }
 333 }
 334
 335 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
 336 {
 337         struct relayd_host *host;
 338
 339         DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
 340                 rif->ifname,
 341                 IP_BUF(pkt->arp.arp_tpa),
 342                 IP_BUF(pkt->arp.arp_spa),
 343                 MAC_BUF(pkt->eth.ether_shost));
 344
 345         if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
 346                 return;
 347
 348         relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
 349
 350         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 351
 352         /*
 353          * If a host is being pinged because of a timeout, do not use the cached
 354          * entry here. That way we can avoid giving out stale data in case the node
 355          * has moved. We shouldn't relay requests here either, as we might miss our
 356          * chance to create a host route.
 357          */
 358         if (host && host->cleanup_pending)
 359                 return;
 360
 361         relay_arp_request(rif, pkt);
 362 }
 363
 364
 365 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
 366 {
 367         struct relayd_host *host;
 368
 369         DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
 370                 rif->ifname,
 371                 IP_BUF(pkt->arp.arp_spa),
 372                 MAC_BUF(pkt->eth.ether_shost),
 373                 IP_BUF(pkt->arp.arp_tpa));
 374
 375         if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
 376                 relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
 377
 378         if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4))
 379                 return;
 380
 381         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 382         if (!host)
 383                 return;
 384
 385         if (host->rif == rif)
 386                 return;
 387
 388         send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
 389 }
 390
 391 static void recv_packet(struct uloop_fd *fd, unsigned int events)
 392 {
 393         struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
 394         struct arp_packet *pkt;
 395         static char pktbuf[4096];
 396         int pktlen;
 397
 398         do {
 399                 if (rif->fd.error)
 400                         uloop_end();
 401
 402                 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
 403                 if (pktlen < 0) {
 404                         if (errno == EINTR)
 405                                 continue;
 406
 407                         break;
 408                 }
 409
 410                 if (!pktlen)
 411                         break;
 412
 413                 pkt = (void *)pktbuf;
 414                 if (pkt->arp.arp_op == htons(ARPOP_REPLY))
 415                         recv_arp_reply(rif, pkt);
 416                 else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
 417                         recv_arp_request(rif, pkt);
 418                 else
 419                         DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
 420
 421         } while (1);
 422 }
 423
 424 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
 425 {
 426         struct relayd_interface *rif;
 427         struct ether_header *eth = packet;
 428
 429         list_for_each_entry(rif, &interfaces, list) {
 430                 if (rif == from_rif)
 431                         continue;
 432
 433                 DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
 434                 memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
 435                 send(rif->bcast_fd.fd, packet, len, 0);
 436         }
 437 }
 438
 439 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
 440 {
 441         struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
 442         static char pktbuf[4096];
 443         int pktlen;
 444
 445         do {
 446                 if (rif->fd.error)
 447                         uloop_end();
 448
 449                 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
 450                 if (pktlen < 0) {
 451                         if (errno == EINTR)
 452                                 continue;
 453
 454                         break;
 455                 }
 456
 457                 if (!pktlen)
 458                         break;
 459
 460                 if (!forward_bcast && !forward_dhcp)
 461                         continue;
 462
 463                 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
 464                         continue;
 465
 466                 if (forward_bcast)
 467                         relayd_forward_bcast_packet(rif, pktbuf, pktlen);
 468         } while (1);
 469 }
 470
 471
 472 static int init_interface(struct relayd_interface *rif)
 473 {
 474         struct sockaddr_ll *sll = &rif->sll;
 475         struct sockaddr_in *sin;
 476         struct ifreq ifr;
 477         int fd = rif->fd.fd;
 478 #ifdef PACKET_RECV_TYPE
 479         unsigned int pkt_type;
 480 #endif
 481
 482         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
 483         if (fd < 0)
 484                 return -1;
 485
 486         rif->fd.fd = fd;
 487
 488         memset(&ifr, 0, sizeof(ifr));
 489         strcpy(ifr.ifr_name, rif->ifname);
 490
 491         if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
 492                 perror("ioctl(SIOCGIFHWADDR)");
 493                 return -1;
 494         }
 495
 496         memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
 497         sll->sll_family = AF_PACKET;
 498         sll->sll_protocol = htons(ETH_P_ARP);
 499         sll->sll_pkttype = PACKET_BROADCAST;
 500         sll->sll_hatype = ARPHRD_ETHER;
 501         sll->sll_halen = ETH_ALEN;
 502
 503         if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
 504                 perror("ioctl(SIOCGIFINDEX)");
 505                 return -1;
 506         }
 507
 508         sll->sll_ifindex = ifr.ifr_ifindex;
 509
 510         if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
 511                 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
 512         } else {
 513                 sin = (struct sockaddr_in *) &ifr.ifr_addr;
 514                 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
 515         }
 516
 517         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 518                 perror("bind(ETH_P_ARP)");
 519                 return -1;
 520         }
 521
 522         rif->fd.cb = recv_packet;
 523         uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 524
 525         if (!forward_bcast && !forward_dhcp)
 526                 return 0;
 527
 528         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
 529         if (fd < 0)
 530                 return 0;
 531
 532         rif->bcast_fd.fd = fd;
 533         rif->bcast_fd.cb = recv_bcast_packet;
 534
 535         memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
 536         sll = &rif->bcast_sll;
 537         sll->sll_protocol = htons(ETH_P_IP);
 538
 539         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 540                 perror("bind(ETH_P_IP)");
 541                 return 0;
 542         }
 543
 544 #ifdef PACKET_RECV_TYPE
 545         pkt_type = (1 << PACKET_BROADCAST);
 546         setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
 547 #endif
 548
 549         uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 550         relayd_add_interface_routes(rif);
 551         return 0;
 552 }
 553
 554 static void ping_static_routes(void)
 555 {
 556         struct relayd_pending_route *rt;
 557         struct relayd_interface *rif;
 558
 559         list_for_each_entry(rt, &pending_routes, rt.list)
 560                 list_for_each_entry(rif, &interfaces, list)
 561                         send_arp_request(rif, rt->gateway);
 562 }
 563
 564 static int init_interfaces(void)
 565 {
 566         struct relayd_interface *rif;
 567         int ret;
 568
 569         list_for_each_entry(rif, &interfaces, list) {
 570                 ret = init_interface(rif);
 571                 if (ret < 0)
 572                         return ret;
 573         }
 574
 575         return 0;
 576 }
 577
 578 static void cleanup_hosts(void)
 579 {
 580         struct relayd_interface *rif;
 581         struct relayd_host *host, *tmp;
 582
 583         list_for_each_entry(rif, &interfaces, list) {
 584                 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
 585                         del_host(host);
 586                 }
 587         }
 588 }
 589
 590 static void free_interfaces(void)
 591 {
 592         struct relayd_interface *rif, *rtmp;
 593
 594         list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
 595                 relayd_del_interface_routes(rif);
 596                 list_del(&rif->list);
 597                 free(rif);
 598         }
 599 }
 600
 601 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
 602 {
 603         struct relayd_interface *rif;
 604
 605         if (strlen(ifname) >= IFNAMSIZ)
 606                 return NULL;
 607
 608         rif = calloc(1, sizeof(*rif));
 609         if (!rif)
 610                 return NULL;
 611
 612         INIT_LIST_HEAD(&rif->hosts);
 613         strcpy(rif->ifname, ifname);
 614         list_add(&rif->list, &interfaces);
 615         rif->managed = managed;
 616
 617         return rif;
 618 }
 619
 620 static void die(int signo)
 621 {
 622         /*
 623          * When we hit SIGTERM, clean up interfaces directly, so that we
 624          * won't leave our routing in an invalid state.
 625          */
 626         cleanup_hosts();
 627         free_interfaces();
 628         exit(1);
 629 }
 630
 631 static int usage(const char *progname)
 632 {
 633         fprintf(stderr, "Usage: %s <options>\n"
 634                         "\n"
 635                         "Options:\n"
 636                         "       -d              Enable debug messages\n"
 637                         "       -i <ifname>     Add an interface for relaying\n"
 638                         "       -I <ifname>     Same as -i, except with ARP cache and host route management\n"
 639                         "                       You need to specify at least two interfaces\n"
 640                         "       -G <ip>         Set a gateway IP for clients\n"
 641                         "       -R <gateway>:<net>/<mask>\n"
 642                         "                       Add a static route for <net>/<mask> via <gateway>\n"
 643                         "       -t <timeout>    Host entry expiry timeout\n"
 644                         "       -T <table>      Set routing table number for automatically added routes\n"
 645                         "       -B              Enable broadcast forwarding\n"
 646                         "       -D              Enable DHCP forwarding\n"
 647                         "       -L <ipaddr>     Enable local access using <ipaddr> as source address\n"
 648                         "\n",
 649                 progname);
 650         return -1;
 651 }
 652
 653 int main(int argc, char **argv)
 654 {
 655         struct relayd_interface *rif = NULL;
 656         struct in_addr addr, addr2;
 657         bool local_addr_valid = false;
 658         bool managed;
 659         int ifnum = 0;
 660         char *s, *s2;
 661         int mask;
 662         int ch;
 663
 664         debug = 0;
 665         inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
 666         if (inet_sock < 0) {
 667                 perror("socket(AF_INET)");
 668                 return 1;
 669         }
 670
 671         host_timeout = 60;
 672         forward_bcast = 0;
 673         local_route_table = 0;
 674         uloop_init();
 675
 676         while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:L:")) != -1) {
 677                 switch(ch) {
 678                 case 'I':
 679                         managed = true;
 680                         /* fall through */
 681                 case 'i':
 682                         ifnum++;
 683                         rif = alloc_interface(optarg, managed);
 684                         if (!rif)
 685                                 return 1;
 686
 687                         managed = false;
 688                         break;
 689                 case 't':
 690                         host_timeout = atoi(optarg);
 691                         if (host_timeout <= 0)
 692                                 return usage(argv[0]);
 693                         break;
 694                 case 'd':
 695                         debug++;
 696                         break;
 697                 case 'B':
 698                         forward_bcast = 1;
 699                         break;
 700                 case 'D':
 701                         forward_dhcp = 1;
 702                         break;
 703                 case 'T':
 704                         route_table = atoi(optarg);
 705                         if (route_table <= 0)
 706                                 return usage(argv[0]);
 707                         break;
 708                 case 'G':
 709                         if (!inet_aton(optarg, &addr)) {
 710                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 711                                 return 1;
 712                         }
 713                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
 714                         break;
 715                 case 'L':
 716                         if (!inet_aton(optarg, &addr)) {
 717                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 718                                 return 1;
 719                         }
 720                         memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
 721                         local_addr_valid = true;
 722                         break;
 723                 case 'R':
 724                         s = strchr(optarg, ':');
 725                         if (!s)
 726                                 return usage(argv[0]);
 727
 728                         *(s++) = 0;
 729                         if (!inet_aton(optarg, &addr)) {
 730                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 731                                 return 1;
 732                         }
 733
 734                         s2 = strchr(s, '/');
 735                         if (!s2)
 736                                 return usage(argv[0]);
 737
 738                         *(s2++) = 0;
 739                         if (!inet_aton(s, &addr2)) {
 740                                 fprintf(stderr, "Address '%s' not found\n", s);
 741                                 return 1;
 742                         }
 743
 744                         mask = atoi(s2);
 745                         if (mask < 0 || mask > 32)
 746                                 return usage(argv[0]);
 747
 748                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
 749                         break;
 750                 case '?':
 751                 default:
 752                         return usage(argv[0]);
 753                 }
 754         }
 755
 756         if (list_empty(&interfaces))
 757                 return usage(argv[0]);
 758
 759         if (ifnum < 2) {
 760                 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
 761                 return -1;
 762         }
 763
 764         argc -= optind;
 765         argv += optind;
 766
 767         signal(SIGTERM, die);
 768         signal(SIGHUP, die);
 769         signal(SIGUSR1, die);
 770         signal(SIGUSR2, die);
 771
 772         if (local_addr_valid)
 773                 local_route_table = route_table++;
 774
 775         if (relayd_rtnl_init() < 0)
 776                 return 1;
 777
 778         if (init_interfaces() < 0)
 779                 return 1;
 780
 781         ping_static_routes();
 782
 783         uloop_run();
 784         uloop_done();
 785
 786         cleanup_hosts();
 787         free_interfaces();
 788         relayd_rtnl_done();
 789         close(inet_sock);
 790
 791         return 0;
 792 }