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 host_ping_tries;
  40 static int inet_sock;
  41 static int forward_bcast;
  42 static int forward_dhcp;
  43
  44 uint8_t local_addr[4];
  45 int local_route_table;
  46
  47 struct relayd_pending_route {
  48         struct relayd_route rt;
  49         struct uloop_timeout timeout;
  50         uint8_t gateway[4];
  51 };
  52
  53 static struct relayd_host *find_host_by_ipaddr(struct relayd_interface *rif, const uint8_t *ipaddr)
  54 {
  55         struct relayd_host *host;
  56
  57         if (!rif) {
  58                 list_for_each_entry(rif, &interfaces, list) {
  59                         host = find_host_by_ipaddr(rif, ipaddr);
  60                         if (!host)
  61                                 continue;
  62
  63                         return host;
  64                 }
  65                 return NULL;
  66         }
  67
  68         list_for_each_entry(host, &rif->hosts, list) {
  69                 if (memcmp(ipaddr, host->ipaddr, sizeof(host->ipaddr)) != 0)
  70                         continue;
  71
  72                 return host;
  73         }
  74         return NULL;
  75 }
  76
  77 static void add_arp(struct relayd_host *host)
  78 {
  79         struct sockaddr_in *sin;
  80         struct arpreq arp;
  81
  82         strncpy(arp.arp_dev, host->rif->ifname, sizeof(arp.arp_dev));
  83         arp.arp_flags = ATF_COM;
  84
  85         arp.arp_ha.sa_family = ARPHRD_ETHER;
  86         memcpy(arp.arp_ha.sa_data, host->lladdr, ETH_ALEN);
  87
  88         sin = (struct sockaddr_in *) &arp.arp_pa;
  89         sin->sin_family = AF_INET;
  90         memcpy(&sin->sin_addr, host->ipaddr, sizeof(host->ipaddr));
  91
  92         ioctl(inet_sock, SIOCSARP, &arp);
  93 }
  94
  95 static void timeout_host_route(struct uloop_timeout *timeout)
  96 {
  97         struct relayd_pending_route *rt;
  98
  99         rt = container_of(timeout, struct relayd_pending_route, timeout);
 100         list_del(&rt->rt.list);
 101         free(rt);
 102 }
 103
 104 void relayd_add_host_route(struct relayd_host *host, const uint8_t *dest, uint8_t mask)
 105 {
 106         struct relayd_route *rt;
 107
 108         list_for_each_entry(rt, &host->routes, list) {
 109                 if (!memcmp(rt->dest, dest, sizeof(rt->dest)) && rt->mask == mask)
 110                         return;
 111         }
 112
 113         rt = calloc(1, sizeof(*rt));
 114         if (!rt)
 115                 return;
 116
 117         list_add(&rt->list, &host->routes);
 118         memcpy(rt->dest, dest, sizeof(rt->dest));
 119         rt->mask = mask;
 120         relayd_add_route(host, rt);
 121 }
 122
 123 static void del_host(struct relayd_host *host)
 124 {
 125         struct relayd_route *route, *tmp;
 126
 127         DPRINTF(1, "%s: deleting host "IP_FMT" ("MAC_FMT")\n", host->rif->ifname,
 128                 IP_BUF(host->ipaddr), MAC_BUF(host->lladdr));
 129
 130         list_for_each_entry_safe(route, tmp, &host->routes, list) {
 131                 relayd_del_route(host, route);
 132                 list_del(&route->list);
 133                 free(route);
 134         }
 135         if (host->rif->managed)
 136                 relayd_del_route(host, NULL);
 137         uloop_timeout_cancel(&host->timeout);
 138         list_del(&host->list);
 139         free(host);
 140 }
 141
 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])
 144 {
 145         memset(pkt, 0, sizeof(*pkt));
 146
 147         pkt->eth.ether_type = htons(ETHERTYPE_ARP);
 148         memcpy(pkt->eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
 149
 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);
 153
 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;
 158 }
 159
 160 static void send_arp_request(struct relayd_interface *rif, const uint8_t *ipaddr)
 161 {
 162         struct arp_packet pkt;
 163
 164         fill_arp_packet(&pkt, rif, rif->src_ip, ipaddr);
 165
 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);
 170
 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));
 174
 175         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 176                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 177 }
 178
 179 void relayd_add_pending_route(const uint8_t *gateway, const uint8_t *dest, uint8_t mask, int timeout)
 180 {
 181         struct relayd_pending_route *rt;
 182         struct relayd_interface *rif;
 183         struct relayd_host *host;
 184
 185         host = find_host_by_ipaddr(NULL, gateway);
 186         if (host) {
 187                 relayd_add_host_route(host, dest, mask);
 188                 return;
 189         }
 190
 191         rt = calloc(1, sizeof(*rt));
 192         if (!rt)
 193                 return;
 194
 195         memcpy(rt->gateway, gateway, sizeof(rt->gateway));
 196         memcpy(rt->rt.dest, dest, sizeof(rt->rt.dest));
 197         rt->rt.mask = mask;
 198         list_add(&rt->rt.list, &pending_routes);
 199         if (timeout <= 0)
 200                 return;
 201
 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);
 206         }
 207 }
 208
 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])
 211 {
 212         struct arp_packet pkt;
 213
 214         fill_arp_packet(&pkt, rif, spa, tpa);
 215
 216         if (tha) {
 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);
 220
 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));
 224         } else {
 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);
 228
 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));
 232         }
 233
 234         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 235                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 236
 237         if (tha)
 238                 return;
 239
 240         /*
 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...
 244          */
 245         pkt.arp.arp_op = htons(ARPOP_REPLY);
 246
 247         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 248                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 249
 250 }
 251
 252 static void host_entry_timeout(struct uloop_timeout *timeout)
 253 {
 254         struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
 255
 256         /*
 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
 261          * giving up on it.
 262          */
 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);
 267                 return;
 268         }
 269         del_host(host);
 270 }
 271
 272 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 273 {
 274         struct relayd_host *host;
 275         struct relayd_pending_route *route, *rtmp;
 276
 277         DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
 278                         IP_BUF(ipaddr), MAC_BUF(lladdr));
 279
 280         host = calloc(1, sizeof(*host));
 281         INIT_LIST_HEAD(&host->routes);
 282         host->rif = rif;
 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);
 288
 289         add_arp(host);
 290         if (rif->managed)
 291                 relayd_add_route(host, NULL);
 292
 293         list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
 294                 if (memcmp(route->gateway, ipaddr, 4) != 0)
 295                         continue;
 296
 297                 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
 298                 if (!route->timeout.pending)
 299                         continue;
 300
 301                 uloop_timeout_cancel(&route->timeout);
 302                 list_del(&route->rt.list);
 303                 free(route);
 304         }
 305
 306         return host;
 307 }
 308
 309 static void send_gratuitous_arp(struct relayd_interface *rif, const uint8_t *spa)
 310 {
 311         struct relayd_interface *to_rif;
 312
 313         list_for_each_entry(to_rif, &interfaces, list) {
 314                 if (rif == to_rif)
 315                         continue;
 316
 317                 send_arp_reply(to_rif, spa, NULL, spa);
 318         }
 319 }
 320
 321
 322 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 323 {
 324         struct relayd_host *host;
 325
 326         host = find_host_by_ipaddr(rif, ipaddr);
 327         if (!host) {
 328                 host = find_host_by_ipaddr(NULL, ipaddr);
 329
 330                 /*
 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
 333                  * host has moved.
 334                  * If the old entry is behind a managed interface, it will be pinged
 335                  * before we expire it
 336                  */
 337                 if (host && !host->cleanup_pending) {
 338                         uloop_timeout_set(&host->timeout, 1);
 339                         return NULL;
 340                 }
 341
 342                 host = add_host(rif, lladdr, ipaddr);
 343         } else {
 344                 host->cleanup_pending = false;
 345                 uloop_timeout_set(&host->timeout, host_timeout * 1000);
 346                 send_gratuitous_arp(rif, ipaddr);
 347         }
 348
 349         return host;
 350 }
 351
 352 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
 353 {
 354         struct relayd_interface *rif;
 355         struct arp_packet reqpkt;
 356
 357         memcpy(&reqpkt, pkt, sizeof(reqpkt));
 358         list_for_each_entry(rif, &interfaces, list) {
 359                 if (rif == from_rif)
 360                         continue;
 361
 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);
 366
 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));
 370
 371                 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
 372                         (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 373         }
 374 }
 375
 376 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
 377 {
 378         struct relayd_host *host;
 379
 380         DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
 381                 rif->ifname,
 382                 IP_BUF(pkt->arp.arp_tpa),
 383                 IP_BUF(pkt->arp.arp_spa),
 384                 MAC_BUF(pkt->eth.ether_shost));
 385
 386         if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
 387                 return;
 388
 389         if (local_route_table && !memcmp(pkt->arp.arp_tpa, local_addr, sizeof(local_addr))) {
 390                 send_arp_reply(rif, local_addr, pkt->arp.arp_sha, pkt->arp.arp_spa);
 391                 return;
 392         }
 393
 394         host = find_host_by_ipaddr(NULL, pkt->arp.arp_spa);
 395         if (!host || host->rif != rif)
 396                 relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
 397
 398         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 399
 400         /*
 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.
 405          */
 406         if (host && host->cleanup_pending)
 407                 return;
 408
 409         relay_arp_request(rif, pkt);
 410 }
 411
 412 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
 413 {
 414         struct relayd_host *host;
 415
 416         DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
 417                 rif->ifname,
 418                 IP_BUF(pkt->arp.arp_spa),
 419                 MAC_BUF(pkt->eth.ether_shost),
 420                 IP_BUF(pkt->arp.arp_tpa));
 421
 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);
 424
 425         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 426         if (!host)
 427                 return;
 428
 429         if (host->rif == rif)
 430                 return;
 431
 432         send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
 433 }
 434
 435 static void recv_packet(struct uloop_fd *fd, unsigned int events)
 436 {
 437         struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
 438         struct arp_packet *pkt;
 439         static char pktbuf[4096];
 440         int pktlen;
 441
 442         do {
 443                 if (rif->fd.error)
 444                         uloop_end();
 445
 446                 pktlen = recv(rif->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                 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);
 462                 else
 463                         DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
 464
 465         } while (1);
 466 }
 467
 468 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
 469 {
 470         struct relayd_interface *rif;
 471         struct ether_header *eth = packet;
 472
 473         list_for_each_entry(rif, &interfaces, list) {
 474                 if (rif == from_rif)
 475                         continue;
 476
 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);
 480         }
 481 }
 482
 483 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
 484 {
 485         struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
 486         static char pktbuf[4096];
 487         int pktlen;
 488
 489         do {
 490                 if (rif->fd.error)
 491                         uloop_end();
 492
 493                 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
 494                 if (pktlen < 0) {
 495                         if (errno == EINTR)
 496                                 continue;
 497
 498                         break;
 499                 }
 500
 501                 if (!pktlen)
 502                         break;
 503
 504                 if (!forward_bcast && !forward_dhcp)
 505                         continue;
 506
 507                 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
 508                         continue;
 509
 510                 if (forward_bcast)
 511                         relayd_forward_bcast_packet(rif, pktbuf, pktlen);
 512         } while (1);
 513 }
 514
 515
 516 static int init_interface(struct relayd_interface *rif)
 517 {
 518         struct sockaddr_ll *sll = &rif->sll;
 519         struct sockaddr_in *sin;
 520         struct ifreq ifr;
 521         int fd = rif->fd.fd;
 522 #ifdef PACKET_RECV_TYPE
 523         unsigned int pkt_type;
 524 #endif
 525
 526         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
 527         if (fd < 0)
 528                 return -1;
 529
 530         rif->fd.fd = fd;
 531
 532         memset(&ifr, 0, sizeof(ifr));
 533         strcpy(ifr.ifr_name, rif->ifname);
 534
 535         if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
 536                 perror("ioctl(SIOCGIFHWADDR)");
 537                 return -1;
 538         }
 539
 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;
 546
 547         if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
 548                 perror("ioctl(SIOCGIFINDEX)");
 549                 return -1;
 550         }
 551
 552         sll->sll_ifindex = ifr.ifr_ifindex;
 553
 554         if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
 555                 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
 556         } else {
 557                 sin = (struct sockaddr_in *) &ifr.ifr_addr;
 558                 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
 559         }
 560
 561         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 562                 perror("bind(ETH_P_ARP)");
 563                 return -1;
 564         }
 565
 566         rif->fd.cb = recv_packet;
 567         uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 568
 569         if (!forward_bcast && !forward_dhcp)
 570                 return 0;
 571
 572         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
 573         if (fd < 0)
 574                 return 0;
 575
 576         rif->bcast_fd.fd = fd;
 577         rif->bcast_fd.cb = recv_bcast_packet;
 578
 579         memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
 580         sll = &rif->bcast_sll;
 581         sll->sll_protocol = htons(ETH_P_IP);
 582
 583         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 584                 perror("bind(ETH_P_IP)");
 585                 return 0;
 586         }
 587
 588 #ifdef PACKET_RECV_TYPE
 589         pkt_type = (1 << PACKET_BROADCAST);
 590         setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
 591 #endif
 592
 593         uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 594         relayd_add_interface_routes(rif);
 595         return 0;
 596 }
 597
 598 static void ping_static_routes(void)
 599 {
 600         struct relayd_pending_route *rt;
 601         struct relayd_interface *rif;
 602
 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);
 606 }
 607
 608 static int init_interfaces(void)
 609 {
 610         struct relayd_interface *rif;
 611         int ret;
 612
 613         list_for_each_entry(rif, &interfaces, list) {
 614                 ret = init_interface(rif);
 615                 if (ret < 0)
 616                         return ret;
 617         }
 618
 619         return 0;
 620 }
 621
 622 static void cleanup_hosts(void)
 623 {
 624         struct relayd_interface *rif;
 625         struct relayd_host *host, *tmp;
 626
 627         list_for_each_entry(rif, &interfaces, list) {
 628                 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
 629                         del_host(host);
 630                 }
 631         }
 632 }
 633
 634 static void free_interfaces(void)
 635 {
 636         struct relayd_interface *rif, *rtmp;
 637
 638         list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
 639                 relayd_del_interface_routes(rif);
 640                 list_del(&rif->list);
 641                 free(rif);
 642         }
 643 }
 644
 645 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
 646 {
 647         struct relayd_interface *rif;
 648
 649         if (strlen(ifname) >= IFNAMSIZ)
 650                 return NULL;
 651
 652         rif = calloc(1, sizeof(*rif));
 653         if (!rif)
 654                 return NULL;
 655
 656         INIT_LIST_HEAD(&rif->hosts);
 657         strcpy(rif->ifname, ifname);
 658         list_add(&rif->list, &interfaces);
 659         rif->managed = managed;
 660
 661         return rif;
 662 }
 663
 664 static void die(int signo)
 665 {
 666         /*
 667          * When we hit SIGTERM, clean up interfaces directly, so that we
 668          * won't leave our routing in an invalid state.
 669          */
 670         cleanup_hosts();
 671         free_interfaces();
 672         exit(1);
 673 }
 674
 675 static int usage(const char *progname)
 676 {
 677         fprintf(stderr, "Usage: %s <options>\n"
 678                         "\n"
 679                         "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"
 693                         "\n",
 694                 progname);
 695         return -1;
 696 }
 697
 698 int main(int argc, char **argv)
 699 {
 700         struct relayd_interface *rif = NULL;
 701         struct in_addr addr, addr2;
 702         bool local_addr_valid = false;
 703         bool managed;
 704         int ifnum = 0;
 705         char *s, *s2;
 706         int mask;
 707         int ch;
 708
 709         debug = 0;
 710         inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
 711         if (inet_sock < 0) {
 712                 perror("socket(AF_INET)");
 713                 return 1;
 714         }
 715
 716         host_timeout = 30;
 717         host_ping_tries = 5;
 718         forward_bcast = 0;
 719         local_route_table = 0;
 720         uloop_init();
 721
 722         while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:L:")) != -1) {
 723                 switch(ch) {
 724                 case 'I':
 725                         managed = true;
 726                         /* fall through */
 727                 case 'i':
 728                         ifnum++;
 729                         rif = alloc_interface(optarg, managed);
 730                         if (!rif)
 731                                 return 1;
 732
 733                         managed = false;
 734                         break;
 735                 case 't':
 736                         host_timeout = atoi(optarg);
 737                         if (host_timeout <= 0)
 738                                 return usage(argv[0]);
 739                         break;
 740                 case 'p':
 741                         host_ping_tries = atoi(optarg);
 742                         if (host_ping_tries <= 0)
 743                                 return usage(argv[0]);
 744                         break;
 745                 case 'd':
 746                         debug++;
 747                         break;
 748                 case 'B':
 749                         forward_bcast = 1;
 750                         break;
 751                 case 'D':
 752                         forward_dhcp = 1;
 753                         break;
 754                 case 'T':
 755                         route_table = atoi(optarg);
 756                         if (route_table <= 0)
 757                                 return usage(argv[0]);
 758                         break;
 759                 case 'G':
 760                         if (!inet_aton(optarg, &addr)) {
 761                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 762                                 return 1;
 763                         }
 764                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
 765                         break;
 766                 case 'L':
 767                         if (!inet_aton(optarg, &addr)) {
 768                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 769                                 return 1;
 770                         }
 771                         memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
 772                         local_addr_valid = true;
 773                         break;
 774                 case 'R':
 775                         s = strchr(optarg, ':');
 776                         if (!s)
 777                                 return usage(argv[0]);
 778
 779                         *(s++) = 0;
 780                         if (!inet_aton(optarg, &addr)) {
 781                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 782                                 return 1;
 783                         }
 784
 785                         s2 = strchr(s, '/');
 786                         if (!s2)
 787                                 return usage(argv[0]);
 788
 789                         *(s2++) = 0;
 790                         if (!inet_aton(s, &addr2)) {
 791                                 fprintf(stderr, "Address '%s' not found\n", s);
 792                                 return 1;
 793                         }
 794
 795                         mask = atoi(s2);
 796                         if (mask < 0 || mask > 32)
 797                                 return usage(argv[0]);
 798
 799                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
 800                         break;
 801                 case '?':
 802                 default:
 803                         return usage(argv[0]);
 804                 }
 805         }
 806
 807         if (list_empty(&interfaces))
 808                 return usage(argv[0]);
 809
 810         if (ifnum < 2) {
 811                 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
 812                 return -1;
 813         }
 814
 815         argc -= optind;
 816         argv += optind;
 817
 818         signal(SIGTERM, die);
 819         signal(SIGHUP, die);
 820         signal(SIGUSR1, die);
 821         signal(SIGUSR2, die);
 822
 823         if (local_addr_valid)
 824                 local_route_table = route_table++;
 825
 826         if (relayd_rtnl_init() < 0)
 827                 return 1;
 828
 829         if (init_interfaces() < 0)
 830                 return 1;
 831
 832         ping_static_routes();
 833
 834         uloop_run();
 835         uloop_done();
 836
 837         cleanup_hosts();
 838         free_interfaces();
 839         relayd_rtnl_done();
 840         close(inet_sock);
 841
 842         return 0;
 843 }