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 struct relayd_pending_route {
  44         struct relayd_route rt;
  45         struct uloop_timeout timeout;
  46         uint8_t gateway[4];
  47 };
  48
  49 static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
  50 {
  51         struct relayd_host *host;
  52
  53         if (!rif) {
  54                 list_for_each_entry(rif, &interfaces, list) {
  55                         host = find_host_by_ipaddr(rif, ipaddr);
  56                         if (!host)
  57                                 continue;
  58
  59                         return host;
  60                 }
  61                 return NULL;
  62         }
  63
  64         list_for_each_entry(host, &rif->hosts, list) {
  65                 if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
  66                         continue;
  67
  68                 return host;
  69         }
  70         return NULL;
  71 }
  72
  73 static void add_arp(struct relayd_host *host)
  74 {
  75         struct sockaddr_in *sin;
  76         struct arpreq arp;
  77
  78         strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
  79         arp.arp_flags = ATF_COM;
  80
  81         arp.arp_ha.sa_family = ARPHRD_ETHER;
  82         memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);
  83
  84         sin = (struct sockaddr_in *) &arp.arp_pa;
  85         sin->sin_family = AF_INET;
  86         memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));
  87
  88         ioctl(inet_sock, SIOCSARP, &arp);
  89 }
  90
  91 static void timeout_host_route(struct uloop_timeout *timeout)
  92 {
  93         struct relayd_pending_route *rt;
  94
  95         rt = container_of(timeout, struct relayd_pending_route, timeout);
  96         list_del(&rt->rt.list);
  97         free(rt);
  98 }
  99
 100 void relayd_add_host_route(struct relayd_host *host, const uint8_t *dest, uint8_t mask)
 101 {
 102         struct relayd_route *rt;
 103
 104         list_for_each_entry(rt, &host->routes, list) {
 105                 if (!memcmp(rt->dest, dest, sizeof(rt->dest)) && rt->mask == mask)
 106                         return;
 107         }
 108
 109         rt = calloc(1, sizeof(*rt));
 110         if (!rt)
 111                 return;
 112
 113         list_add(&rt->list, &host->routes);
 114         memcpy(rt->dest, dest, sizeof(rt->dest));
 115         rt->mask = mask;
 116         relayd_add_route(host, rt);
 117 }
 118
 119 static void del_host(struct relayd_host *host)
 120 {
 121         struct relayd_route *route, *tmp;
 122
 123         DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
 124                 IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));
 125
 126         list_for_each_entry_safe(route, tmp, &host->routes, list) {
 127                 relayd_del_route(host, route);
 128                 list_del(&route->list);
 129                 free(route);
 130         }
 131         if (host->rif->managed)
 132                 relayd_del_route(host, NULL);
 133         uloop_timeout_cancel(&host->timeout);
 134         list_del(&host->list);
 135         free(host);
 136 }
 137
 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])
 140 {
 141         memset(pkt, 0, sizeof(*pkt));
 142
 143         pkt->eth.ether_type = htons(ETHERTYPE_ARP);
 144         memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
 145
 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);
 149
 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;
 154 }
 155
 156 static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr)
 157 {
 158         struct arp_packet pkt;
 159
 160         fill_arp_request(&pkt, rif, rif->src_ip, ipaddr);
 161
 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);
 166
 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));
 170
 171         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 172                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 173 }
 174
 175 void relayd_add_pending_route(const uint8_t *gateway, const uint8_t *dest, uint8_t mask, int timeout)
 176 {
 177         struct relayd_pending_route *rt;
 178         struct relayd_interface *rif;
 179         struct relayd_host *host;
 180
 181         host = find_host_by_ipaddr(NULL, gateway);
 182         if (host) {
 183                 relayd_add_host_route(host, dest, mask);
 184                 return;
 185         }
 186
 187         rt = calloc(1, sizeof(*rt));
 188         if (!rt)
 189                 return;
 190
 191         memcpy(rt->gateway, gateway, sizeof(rt->gateway));
 192         memcpy(rt->rt.dest, dest, sizeof(rt->rt.dest));
 193         rt->rt.mask = mask;
 194         list_add(&rt->rt.list, &pending_routes);
 195         if (timeout <= 0)
 196                 return;
 197
 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);
 202         }
 203 }
 204
 205 static void send_arp_reply(struct relayd_interface *rif, uint8_t spa[4],
 206                            uint8_t tha[ETH_ALEN], uint8_t tpa[4])
 207 {
 208         struct arp_packet pkt;
 209
 210         fill_arp_request(&pkt, rif, spa, tpa);
 211
 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);
 215
 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));
 219
 220         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 221                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 222 }
 223
 224 static void host_entry_timeout(struct uloop_timeout *timeout)
 225 {
 226         struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
 227
 228         /*
 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
 233          * giving up on it.
 234          */
 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);
 239                 return;
 240         }
 241         del_host(host);
 242 }
 243
 244 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 245 {
 246         struct relayd_host *host;
 247         struct relayd_pending_route *route, *rtmp;
 248
 249         DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
 250                         IP_BUF(ipaddr), MAC_BUF(lladdr));
 251
 252         host = calloc(1, sizeof(*host));
 253         INIT_LIST_HEAD(&host->routes);
 254         host->rif = rif;
 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);
 260
 261         add_arp(host);
 262         if (rif->managed)
 263                 relayd_add_route(host, NULL);
 264
 265         list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
 266                 if (memcmp(route->gateway, ipaddr, 4) != 0)
 267                         continue;
 268
 269                 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
 270                 if (!route->timeout.pending)
 271                         continue;
 272
 273                 uloop_timeout_cancel(&route->timeout);
 274                 list_del(&route->rt.list);
 275                 free(route);
 276         }
 277
 278         return host;
 279 }
 280
 281 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 282 {
 283         struct relayd_host *host;
 284
 285         host = find_host_by_ipaddr(rif, ipaddr);
 286         if (!host) {
 287                 host = find_host_by_ipaddr(NULL, ipaddr);
 288
 289                 /*
 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
 292                  * host has moved.
 293                  * If the old entry is behind a managed interface, it will be pinged
 294                  * before we expire it
 295                  */
 296                 if (host && !host->cleanup_pending) {
 297                         uloop_timeout_set(&host->timeout, 1);
 298                         return NULL;
 299                 }
 300
 301                 host = add_host(rif, lladdr, ipaddr);
 302         } else {
 303                 host->cleanup_pending = false;
 304                 uloop_timeout_set(&host->timeout, host_timeout * 1000);
 305         }
 306
 307         return host;
 308 }
 309
 310 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
 311 {
 312         struct relayd_interface *rif;
 313         struct arp_packet reqpkt;
 314
 315         memcpy(&reqpkt, pkt, sizeof(reqpkt));
 316         list_for_each_entry(rif, &interfaces, list) {
 317                 if (rif == from_rif)
 318                         continue;
 319
 320                 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
 321                 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
 322
 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));
 326
 327                 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
 328                         (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 329         }
 330 }
 331
 332 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
 333 {
 334         struct relayd_host *host;
 335
 336         DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
 337                 rif->ifname,
 338                 IP_BUF(pkt->arp.arp_tpa),
 339                 IP_BUF(pkt->arp.arp_spa),
 340                 MAC_BUF(pkt->eth.ether_shost));
 341
 342         if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
 343                 return;
 344
 345         relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
 346
 347         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 348
 349         /*
 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.
 354          */
 355         if (host && host->cleanup_pending)
 356                 return;
 357
 358         relay_arp_request(rif, pkt);
 359 }
 360
 361
 362 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
 363 {
 364         struct relayd_host *host;
 365
 366         DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
 367                 rif->ifname,
 368                 IP_BUF(pkt->arp.arp_spa),
 369                 MAC_BUF(pkt->eth.ether_shost),
 370                 IP_BUF(pkt->arp.arp_tpa));
 371
 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);
 374
 375         if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4))
 376                 return;
 377
 378         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 379         if (!host)
 380                 return;
 381
 382         if (host->rif == rif)
 383                 return;
 384
 385         send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
 386 }
 387
 388 static void recv_packet(struct uloop_fd *fd, unsigned int events)
 389 {
 390         struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
 391         struct arp_packet *pkt;
 392         static char pktbuf[4096];
 393         int pktlen;
 394
 395         do {
 396                 if (rif->fd.error)
 397                         uloop_end();
 398
 399                 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
 400                 if (pktlen < 0) {
 401                         if (errno == EINTR)
 402                                 continue;
 403
 404                         break;
 405                 }
 406
 407                 if (!pktlen)
 408                         break;
 409
 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);
 415                 else
 416                         DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
 417
 418         } while (1);
 419 }
 420
 421 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
 422 {
 423         struct relayd_interface *rif;
 424         struct ether_header *eth = packet;
 425
 426         list_for_each_entry(rif, &interfaces, list) {
 427                 if (rif == from_rif)
 428                         continue;
 429
 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);
 433         }
 434 }
 435
 436 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
 437 {
 438         struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
 439         static char pktbuf[4096];
 440         int pktlen;
 441
 442         do {
 443                 if (rif->fd.error)
 444                         uloop_end();
 445
 446                 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
 447                 if (pktlen < 0) {
 448                         if (errno == EINTR)
 449                                 continue;
 450
 451                         break;
 452                 }
 453
 454                 if (!pktlen)
 455                         break;
 456
 457                 if (!forward_bcast && !forward_dhcp)
 458                         continue;
 459
 460                 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
 461                         continue;
 462
 463                 if (forward_bcast)
 464                         relayd_forward_bcast_packet(rif, pktbuf, pktlen);
 465         } while (1);
 466 }
 467
 468
 469 static int init_interface(struct relayd_interface *rif)
 470 {
 471         struct sockaddr_ll *sll = &rif->sll;
 472         struct sockaddr_in *sin;
 473         struct ifreq ifr;
 474         int fd = rif->fd.fd;
 475 #ifdef PACKET_RECV_TYPE
 476         unsigned int pkt_type;
 477 #endif
 478
 479         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
 480         if (fd < 0)
 481                 return -1;
 482
 483         rif->fd.fd = fd;
 484
 485         memset(&ifr, 0, sizeof(ifr));
 486         strcpy(ifr.ifr_name, rif->ifname);
 487
 488         if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
 489                 perror("ioctl(SIOCGIFHWADDR)");
 490                 return -1;
 491         }
 492
 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;
 499
 500         if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
 501                 perror("ioctl(SIOCGIFINDEX)");
 502                 return -1;
 503         }
 504
 505         sll->sll_ifindex = ifr.ifr_ifindex;
 506
 507         if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
 508                 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
 509         } else {
 510                 sin = (struct sockaddr_in *) &ifr.ifr_addr;
 511                 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
 512         }
 513
 514         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 515                 perror("bind(ETH_P_ARP)");
 516                 return -1;
 517         }
 518
 519         rif->fd.cb = recv_packet;
 520         uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 521
 522         if (!forward_bcast && !forward_dhcp)
 523                 return 0;
 524
 525         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
 526         if (fd < 0)
 527                 return 0;
 528
 529         rif->bcast_fd.fd = fd;
 530         rif->bcast_fd.cb = recv_bcast_packet;
 531
 532         memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
 533         sll = &rif->bcast_sll;
 534         sll->sll_protocol = htons(ETH_P_IP);
 535
 536         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 537                 perror("bind(ETH_P_IP)");
 538                 return 0;
 539         }
 540
 541 #ifdef PACKET_RECV_TYPE
 542         pkt_type = (1 << PACKET_BROADCAST);
 543         setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
 544 #endif
 545
 546         uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 547         relayd_add_interface_routes(rif);
 548         return 0;
 549 }
 550
 551 static void ping_static_routes(void)
 552 {
 553         struct relayd_pending_route *rt;
 554         struct relayd_interface *rif;
 555
 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);
 559 }
 560
 561 static int init_interfaces(void)
 562 {
 563         struct relayd_interface *rif;
 564         int ret;
 565
 566         list_for_each_entry(rif, &interfaces, list) {
 567                 ret = init_interface(rif);
 568                 if (ret < 0)
 569                         return ret;
 570         }
 571
 572         return 0;
 573 }
 574
 575 static void cleanup_hosts(void)
 576 {
 577         struct relayd_interface *rif;
 578         struct relayd_host *host, *tmp;
 579
 580         list_for_each_entry(rif, &interfaces, list) {
 581                 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
 582                         del_host(host);
 583                 }
 584         }
 585 }
 586
 587 static void free_interfaces(void)
 588 {
 589         struct relayd_interface *rif, *rtmp;
 590
 591         list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
 592                 relayd_del_interface_routes(rif);
 593                 list_del(&rif->list);
 594                 free(rif);
 595         }
 596 }
 597
 598 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
 599 {
 600         struct relayd_interface *rif;
 601
 602         if (strlen(ifname) >= IFNAMSIZ)
 603                 return NULL;
 604
 605         rif = calloc(1, sizeof(*rif));
 606         if (!rif)
 607                 return NULL;
 608
 609         INIT_LIST_HEAD(&rif->hosts);
 610         strcpy(rif->ifname, ifname);
 611         list_add(&rif->list, &interfaces);
 612         rif->managed = managed;
 613
 614         return rif;
 615 }
 616
 617 static void die(int signo)
 618 {
 619         /*
 620          * When we hit SIGTERM, clean up interfaces directly, so that we
 621          * won't leave our routing in an invalid state.
 622          */
 623         cleanup_hosts();
 624         free_interfaces();
 625         exit(1);
 626 }
 627
 628 static int usage(const char *progname)
 629 {
 630         fprintf(stderr, "Usage: %s <options>\n"
 631                         "\n"
 632                         "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"
 644                         "\n",
 645                 progname);
 646         return -1;
 647 }
 648
 649 int main(int argc, char **argv)
 650 {
 651         struct relayd_interface *rif = NULL;
 652         struct in_addr addr, addr2;
 653         bool managed;
 654         int ifnum = 0;
 655         char *s, *s2;
 656         int mask;
 657         int ch;
 658
 659         debug = 0;
 660         inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
 661         if (inet_sock < 0) {
 662                 perror("socket(AF_INET)");
 663                 return 1;
 664         }
 665
 666         host_timeout = 60;
 667         forward_bcast = 0;
 668         uloop_init();
 669
 670         while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:")) != -1) {
 671                 switch(ch) {
 672                 case 'I':
 673                         managed = true;
 674                         /* fall through */
 675                 case 'i':
 676                         ifnum++;
 677                         rif = alloc_interface(optarg, managed);
 678                         if (!rif)
 679                                 return 1;
 680
 681                         managed = false;
 682                         break;
 683                 case 't':
 684                         host_timeout = atoi(optarg);
 685                         if (host_timeout <= 0)
 686                                 return usage(argv[0]);
 687                         break;
 688                 case 'd':
 689                         debug++;
 690                         break;
 691                 case 'B':
 692                         forward_bcast = 1;
 693                         break;
 694                 case 'D':
 695                         forward_dhcp = 1;
 696                         break;
 697                 case 'T':
 698                         route_table = atoi(optarg);
 699                         if (route_table <= 0)
 700                                 return usage(argv[0]);
 701                         break;
 702                 case 'G':
 703                         if (!inet_aton(optarg, &addr)) {
 704                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 705                                 return 1;
 706                         }
 707                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
 708                         break;
 709                 case 'R':
 710                         s = strchr(optarg, ':');
 711                         if (!s)
 712                                 return usage(argv[0]);
 713
 714                         *(s++) = 0;
 715                         if (!inet_aton(optarg, &addr)) {
 716                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 717                                 return 1;
 718                         }
 719
 720                         s2 = strchr(s, '/');
 721                         if (!s2)
 722                                 return usage(argv[0]);
 723
 724                         *(s2++) = 0;
 725                         if (!inet_aton(s, &addr2)) {
 726                                 fprintf(stderr, "Address '%s' not found\n", s);
 727                                 return 1;
 728                         }
 729
 730                         mask = atoi(s2);
 731                         if (mask < 0 || mask > 32)
 732                                 return usage(argv[0]);
 733
 734                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
 735                         break;
 736                 case '?':
 737                 default:
 738                         return usage(argv[0]);
 739                 }
 740         }
 741
 742         if (list_empty(&interfaces))
 743                 return usage(argv[0]);
 744
 745         if (ifnum < 2) {
 746                 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
 747                 return -1;
 748         }
 749
 750         argc -= optind;
 751         argv += optind;
 752
 753         signal(SIGTERM, die);
 754         signal(SIGHUP, die);
 755         signal(SIGUSR1, die);
 756         signal(SIGUSR2, die);
 757
 758         if (relayd_rtnl_init() < 0)
 759                 return 1;
 760
 761         if (init_interfaces() < 0)
 762                 return 1;
 763
 764         ping_static_routes();
 765
 766         uloop_run();
 767         uloop_done();
 768
 769         cleanup_hosts();
 770         free_interfaces();
 771         relayd_rtnl_done();
 772         close(inet_sock);
 773
 774         return 0;
 775 }