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, uint8_t spa[4],
 210                            uint8_t tha[ETH_ALEN], uint8_t tpa[4])
 211 {
 212         struct arp_packet pkt;
 213
 214         fill_arp_packet(&pkt, rif, spa, tpa);
 215
 216         pkt.arp.arp_op = htons(ARPOP_REPLY);
 217         if (tha) {
 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                 memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
 226                 memset(pkt.arp.arp_tha, 0, ETH_ALEN);
 227
 228                 DPRINTF(2, "%s: sending gratuitous ARP: "IP_FMT" is at ("MAC_FMT")\n",
 229                         rif->ifname, IP_BUF(pkt.arp.arp_tpa),
 230                         MAC_BUF(pkt.eth.ether_shost));
 231         }
 232
 233         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 234                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 235 }
 236
 237 static void host_entry_timeout(struct uloop_timeout *timeout)
 238 {
 239         struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
 240
 241         /*
 242          * When a host is behind a managed interface, we must not expire its host
 243          * entry prematurely, as this will cause routes to the node to expire,
 244          * leading to loss of connectivity from the other side.
 245          * When the timeout is reached, try pinging the host a few times before
 246          * giving up on it.
 247          */
 248         if (host->rif->managed && host->cleanup_pending < host_ping_tries) {
 249                 send_arp_request(host->rif, host->ipaddr);
 250                 host->cleanup_pending++;
 251                 uloop_timeout_set(&host->timeout, 1000);
 252                 return;
 253         }
 254         del_host(host);
 255 }
 256
 257 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 258 {
 259         struct relayd_host *host;
 260         struct relayd_pending_route *route, *rtmp;
 261
 262         DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
 263                         IP_BUF(ipaddr), MAC_BUF(lladdr));
 264
 265         host = calloc(1, sizeof(*host));
 266         INIT_LIST_HEAD(&host->routes);
 267         host->rif = rif;
 268         memcpy(host->ipaddr, ipaddr, sizeof(host->ipaddr));
 269         memcpy(host->lladdr, lladdr, sizeof(host->lladdr));
 270         list_add(&host->list, &rif->hosts);
 271         host->timeout.cb = host_entry_timeout;
 272         uloop_timeout_set(&host->timeout, host_timeout * 1000);
 273
 274         add_arp(host);
 275         if (rif->managed)
 276                 relayd_add_route(host, NULL);
 277
 278         list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
 279                 if (memcmp(route->gateway, ipaddr, 4) != 0)
 280                         continue;
 281
 282                 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
 283                 if (!route->timeout.pending)
 284                         continue;
 285
 286                 uloop_timeout_cancel(&route->timeout);
 287                 list_del(&route->rt.list);
 288                 free(route);
 289         }
 290
 291         return host;
 292 }
 293
 294 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 295 {
 296         struct relayd_host *host;
 297
 298         host = find_host_by_ipaddr(rif, ipaddr);
 299         if (!host) {
 300                 host = find_host_by_ipaddr(NULL, ipaddr);
 301
 302                 /*
 303                  * When we suddenly see the host appearing on a different interface,
 304                  * reduce the timeout to make the old entry expire faster, in case the
 305                  * host has moved.
 306                  * If the old entry is behind a managed interface, it will be pinged
 307                  * before we expire it
 308                  */
 309                 if (host && !host->cleanup_pending) {
 310                         uloop_timeout_set(&host->timeout, 1);
 311                         return NULL;
 312                 }
 313
 314                 host = add_host(rif, lladdr, ipaddr);
 315         } else {
 316                 host->cleanup_pending = false;
 317                 uloop_timeout_set(&host->timeout, host_timeout * 1000);
 318         }
 319
 320         return host;
 321 }
 322
 323 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
 324 {
 325         struct relayd_interface *rif;
 326         struct arp_packet reqpkt;
 327
 328         memcpy(&reqpkt, pkt, sizeof(reqpkt));
 329         list_for_each_entry(rif, &interfaces, list) {
 330                 if (rif == from_rif)
 331                         continue;
 332
 333                 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
 334                 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
 335
 336                 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
 337                         rif->ifname, IP_BUF(reqpkt.arp.arp_tpa),
 338                         IP_BUF(reqpkt.arp.arp_spa), MAC_BUF(reqpkt.eth.ether_shost));
 339
 340                 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
 341                         (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 342         }
 343 }
 344
 345 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
 346 {
 347         struct relayd_host *host;
 348
 349         DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
 350                 rif->ifname,
 351                 IP_BUF(pkt->arp.arp_tpa),
 352                 IP_BUF(pkt->arp.arp_spa),
 353                 MAC_BUF(pkt->eth.ether_shost));
 354
 355         if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
 356                 return;
 357
 358         if (local_route_table && !memcmp(pkt->arp.arp_tpa, local_addr, sizeof(local_addr))) {
 359                 send_arp_reply(rif, local_addr, pkt->arp.arp_sha, pkt->arp.arp_spa);
 360                 return;
 361         }
 362
 363         host = find_host_by_ipaddr(NULL, pkt->arp.arp_spa);
 364         if (!host || host->rif != rif)
 365                 relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
 366
 367         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 368
 369         /*
 370          * If a host is being pinged because of a timeout, do not use the cached
 371          * entry here. That way we can avoid giving out stale data in case the node
 372          * has moved. We shouldn't relay requests here either, as we might miss our
 373          * chance to create a host route.
 374          */
 375         if (host && host->cleanup_pending)
 376                 return;
 377
 378         relay_arp_request(rif, pkt);
 379 }
 380
 381
 382 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
 383 {
 384         struct relayd_interface *to_rif;
 385         struct relayd_host *host;
 386
 387         DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
 388                 rif->ifname,
 389                 IP_BUF(pkt->arp.arp_spa),
 390                 MAC_BUF(pkt->eth.ether_shost),
 391                 IP_BUF(pkt->arp.arp_tpa));
 392
 393         if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
 394                 relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
 395
 396         if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4)) {
 397                 /*
 398                  * locally initiated lookup, relay as gratuitous ARP
 399                  * to all other interfaces
 400                  */
 401                 list_for_each_entry(to_rif, &interfaces, list) {
 402                         if (rif == to_rif)
 403                                 continue;
 404
 405                         send_arp_reply(to_rif, pkt->arp.arp_spa, NULL, pkt->arp.arp_spa);
 406                 }
 407                 return;
 408         }
 409
 410         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 411         if (!host)
 412                 return;
 413
 414         if (host->rif == rif)
 415                 return;
 416
 417         send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
 418 }
 419
 420 static void recv_packet(struct uloop_fd *fd, unsigned int events)
 421 {
 422         struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
 423         struct arp_packet *pkt;
 424         static char pktbuf[4096];
 425         int pktlen;
 426
 427         do {
 428                 if (rif->fd.error)
 429                         uloop_end();
 430
 431                 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
 432                 if (pktlen < 0) {
 433                         if (errno == EINTR)
 434                                 continue;
 435
 436                         break;
 437                 }
 438
 439                 if (!pktlen)
 440                         break;
 441
 442                 pkt = (void *)pktbuf;
 443                 if (pkt->arp.arp_op == htons(ARPOP_REPLY))
 444                         recv_arp_reply(rif, pkt);
 445                 else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
 446                         recv_arp_request(rif, pkt);
 447                 else
 448                         DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
 449
 450         } while (1);
 451 }
 452
 453 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
 454 {
 455         struct relayd_interface *rif;
 456         struct ether_header *eth = packet;
 457
 458         list_for_each_entry(rif, &interfaces, list) {
 459                 if (rif == from_rif)
 460                         continue;
 461
 462                 DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
 463                 memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
 464                 send(rif->bcast_fd.fd, packet, len, 0);
 465         }
 466 }
 467
 468 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
 469 {
 470         struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
 471         static char pktbuf[4096];
 472         int pktlen;
 473
 474         do {
 475                 if (rif->fd.error)
 476                         uloop_end();
 477
 478                 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
 479                 if (pktlen < 0) {
 480                         if (errno == EINTR)
 481                                 continue;
 482
 483                         break;
 484                 }
 485
 486                 if (!pktlen)
 487                         break;
 488
 489                 if (!forward_bcast && !forward_dhcp)
 490                         continue;
 491
 492                 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
 493                         continue;
 494
 495                 if (forward_bcast)
 496                         relayd_forward_bcast_packet(rif, pktbuf, pktlen);
 497         } while (1);
 498 }
 499
 500
 501 static int init_interface(struct relayd_interface *rif)
 502 {
 503         struct sockaddr_ll *sll = &rif->sll;
 504         struct sockaddr_in *sin;
 505         struct ifreq ifr;
 506         int fd = rif->fd.fd;
 507 #ifdef PACKET_RECV_TYPE
 508         unsigned int pkt_type;
 509 #endif
 510
 511         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
 512         if (fd < 0)
 513                 return -1;
 514
 515         rif->fd.fd = fd;
 516
 517         memset(&ifr, 0, sizeof(ifr));
 518         strcpy(ifr.ifr_name, rif->ifname);
 519
 520         if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
 521                 perror("ioctl(SIOCGIFHWADDR)");
 522                 return -1;
 523         }
 524
 525         memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
 526         sll->sll_family = AF_PACKET;
 527         sll->sll_protocol = htons(ETH_P_ARP);
 528         sll->sll_pkttype = PACKET_BROADCAST;
 529         sll->sll_hatype = ARPHRD_ETHER;
 530         sll->sll_halen = ETH_ALEN;
 531
 532         if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
 533                 perror("ioctl(SIOCGIFINDEX)");
 534                 return -1;
 535         }
 536
 537         sll->sll_ifindex = ifr.ifr_ifindex;
 538
 539         if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
 540                 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
 541         } else {
 542                 sin = (struct sockaddr_in *) &ifr.ifr_addr;
 543                 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
 544         }
 545
 546         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 547                 perror("bind(ETH_P_ARP)");
 548                 return -1;
 549         }
 550
 551         rif->fd.cb = recv_packet;
 552         uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 553
 554         if (!forward_bcast && !forward_dhcp)
 555                 return 0;
 556
 557         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
 558         if (fd < 0)
 559                 return 0;
 560
 561         rif->bcast_fd.fd = fd;
 562         rif->bcast_fd.cb = recv_bcast_packet;
 563
 564         memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
 565         sll = &rif->bcast_sll;
 566         sll->sll_protocol = htons(ETH_P_IP);
 567
 568         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 569                 perror("bind(ETH_P_IP)");
 570                 return 0;
 571         }
 572
 573 #ifdef PACKET_RECV_TYPE
 574         pkt_type = (1 << PACKET_BROADCAST);
 575         setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
 576 #endif
 577
 578         uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 579         relayd_add_interface_routes(rif);
 580         return 0;
 581 }
 582
 583 static void ping_static_routes(void)
 584 {
 585         struct relayd_pending_route *rt;
 586         struct relayd_interface *rif;
 587
 588         list_for_each_entry(rt, &pending_routes, rt.list)
 589                 list_for_each_entry(rif, &interfaces, list)
 590                         send_arp_request(rif, rt->gateway);
 591 }
 592
 593 static int init_interfaces(void)
 594 {
 595         struct relayd_interface *rif;
 596         int ret;
 597
 598         list_for_each_entry(rif, &interfaces, list) {
 599                 ret = init_interface(rif);
 600                 if (ret < 0)
 601                         return ret;
 602         }
 603
 604         return 0;
 605 }
 606
 607 static void cleanup_hosts(void)
 608 {
 609         struct relayd_interface *rif;
 610         struct relayd_host *host, *tmp;
 611
 612         list_for_each_entry(rif, &interfaces, list) {
 613                 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
 614                         del_host(host);
 615                 }
 616         }
 617 }
 618
 619 static void free_interfaces(void)
 620 {
 621         struct relayd_interface *rif, *rtmp;
 622
 623         list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
 624                 relayd_del_interface_routes(rif);
 625                 list_del(&rif->list);
 626                 free(rif);
 627         }
 628 }
 629
 630 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
 631 {
 632         struct relayd_interface *rif;
 633
 634         if (strlen(ifname) >= IFNAMSIZ)
 635                 return NULL;
 636
 637         rif = calloc(1, sizeof(*rif));
 638         if (!rif)
 639                 return NULL;
 640
 641         INIT_LIST_HEAD(&rif->hosts);
 642         strcpy(rif->ifname, ifname);
 643         list_add(&rif->list, &interfaces);
 644         rif->managed = managed;
 645
 646         return rif;
 647 }
 648
 649 static void die(int signo)
 650 {
 651         /*
 652          * When we hit SIGTERM, clean up interfaces directly, so that we
 653          * won't leave our routing in an invalid state.
 654          */
 655         cleanup_hosts();
 656         free_interfaces();
 657         exit(1);
 658 }
 659
 660 static int usage(const char *progname)
 661 {
 662         fprintf(stderr, "Usage: %s <options>\n"
 663                         "\n"
 664                         "Options:\n"
 665                         "       -d              Enable debug messages\n"
 666                         "       -i <ifname>     Add an interface for relaying\n"
 667                         "       -I <ifname>     Same as -i, except with ARP cache and host route management\n"
 668                         "                       You need to specify at least two interfaces\n"
 669                         "       -G <ip>         Set a gateway IP for clients\n"
 670                         "       -R <gateway>:<net>/<mask>\n"
 671                         "                       Add a static route for <net>/<mask> via <gateway>\n"
 672                         "       -t <timeout>    Host entry expiry timeout\n"
 673                         "       -p <tries>      Number of ARP ping attempts before considering a host dead\n"
 674                         "       -T <table>      Set routing table number for automatically added routes\n"
 675                         "       -B              Enable broadcast forwarding\n"
 676                         "       -D              Enable DHCP forwarding\n"
 677                         "       -L <ipaddr>     Enable local access using <ipaddr> as source address\n"
 678                         "\n",
 679                 progname);
 680         return -1;
 681 }
 682
 683 int main(int argc, char **argv)
 684 {
 685         struct relayd_interface *rif = NULL;
 686         struct in_addr addr, addr2;
 687         bool local_addr_valid = false;
 688         bool managed;
 689         int ifnum = 0;
 690         char *s, *s2;
 691         int mask;
 692         int ch;
 693
 694         debug = 0;
 695         inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
 696         if (inet_sock < 0) {
 697                 perror("socket(AF_INET)");
 698                 return 1;
 699         }
 700
 701         host_timeout = 30;
 702         host_ping_tries = 5;
 703         forward_bcast = 0;
 704         local_route_table = 0;
 705         uloop_init();
 706
 707         while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:L:")) != -1) {
 708                 switch(ch) {
 709                 case 'I':
 710                         managed = true;
 711                         /* fall through */
 712                 case 'i':
 713                         ifnum++;
 714                         rif = alloc_interface(optarg, managed);
 715                         if (!rif)
 716                                 return 1;
 717
 718                         managed = false;
 719                         break;
 720                 case 't':
 721                         host_timeout = atoi(optarg);
 722                         if (host_timeout <= 0)
 723                                 return usage(argv[0]);
 724                         break;
 725                 case 'p':
 726                         host_ping_tries = atoi(optarg);
 727                         if (host_ping_tries <= 0)
 728                                 return usage(argv[0]);
 729                         break;
 730                 case 'd':
 731                         debug++;
 732                         break;
 733                 case 'B':
 734                         forward_bcast = 1;
 735                         break;
 736                 case 'D':
 737                         forward_dhcp = 1;
 738                         break;
 739                 case 'T':
 740                         route_table = atoi(optarg);
 741                         if (route_table <= 0)
 742                                 return usage(argv[0]);
 743                         break;
 744                 case 'G':
 745                         if (!inet_aton(optarg, &addr)) {
 746                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 747                                 return 1;
 748                         }
 749                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
 750                         break;
 751                 case 'L':
 752                         if (!inet_aton(optarg, &addr)) {
 753                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 754                                 return 1;
 755                         }
 756                         memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
 757                         local_addr_valid = true;
 758                         break;
 759                 case 'R':
 760                         s = strchr(optarg, ':');
 761                         if (!s)
 762                                 return usage(argv[0]);
 763
 764                         *(s++) = 0;
 765                         if (!inet_aton(optarg, &addr)) {
 766                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 767                                 return 1;
 768                         }
 769
 770                         s2 = strchr(s, '/');
 771                         if (!s2)
 772                                 return usage(argv[0]);
 773
 774                         *(s2++) = 0;
 775                         if (!inet_aton(s, &addr2)) {
 776                                 fprintf(stderr, "Address '%s' not found\n", s);
 777                                 return 1;
 778                         }
 779
 780                         mask = atoi(s2);
 781                         if (mask < 0 || mask > 32)
 782                                 return usage(argv[0]);
 783
 784                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
 785                         break;
 786                 case '?':
 787                 default:
 788                         return usage(argv[0]);
 789                 }
 790         }
 791
 792         if (list_empty(&interfaces))
 793                 return usage(argv[0]);
 794
 795         if (ifnum < 2) {
 796                 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
 797                 return -1;
 798         }
 799
 800         argc -= optind;
 801         argv += optind;
 802
 803         signal(SIGTERM, die);
 804         signal(SIGHUP, die);
 805         signal(SIGUSR1, die);
 806         signal(SIGUSR2, die);
 807
 808         if (local_addr_valid)
 809                 local_route_table = route_table++;
 810
 811         if (relayd_rtnl_init() < 0)
 812                 return 1;
 813
 814         if (init_interfaces() < 0)
 815                 return 1;
 816
 817         ping_static_routes();
 818
 819         uloop_run();
 820         uloop_done();
 821
 822         cleanup_hosts();
 823         free_interfaces();
 824         relayd_rtnl_done();
 825         close(inet_sock);
 826
 827         return 0;
 828 }