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_packet(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_packet(&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_packet(&pkt, rif, spa, tpa);
 214
 215         pkt.arp.arp_op = htons(ARPOP_REPLY);
 216         if (tha) {
 217                 memcpy(pkt.eth.ether_dhost, tha, ETH_ALEN);
 218                 memcpy(pkt.arp.arp_tha, tha, ETH_ALEN);
 219
 220                 DPRINTF(2, "%s: sending ARP reply to "IP_FMT", "IP_FMT" is at ("MAC_FMT")\n",
 221                         rif->ifname, IP_BUF(pkt.arp.arp_tpa),
 222                         IP_BUF(pkt.arp.arp_spa), MAC_BUF(pkt.eth.ether_shost));
 223         } else {
 224                 memset(pkt.eth.ether_dhost, 0xff, ETH_ALEN);
 225                 memset(pkt.arp.arp_tha, 0, ETH_ALEN);
 226
 227                 DPRINTF(2, "%s: sending gratuitous ARP: "IP_FMT" is at ("MAC_FMT")\n",
 228                         rif->ifname, IP_BUF(pkt.arp.arp_tpa),
 229                         MAC_BUF(pkt.eth.ether_shost));
 230         }
 231
 232         sendto(rif->fd.fd, &pkt, sizeof(pkt), 0,
 233                 (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 234 }
 235
 236 static void host_entry_timeout(struct uloop_timeout *timeout)
 237 {
 238         struct relayd_host *host = container_of(timeout, struct relayd_host, timeout);
 239
 240         /*
 241          * When a host is behind a managed interface, we must not expire its host
 242          * entry prematurely, as this will cause routes to the node to expire,
 243          * leading to loss of connectivity from the other side.
 244          * When the timeout is reached, try pinging the host a few times before
 245          * giving up on it.
 246          */
 247         if (host->rif->managed && host->cleanup_pending < 2) {
 248                 send_arp_request(host->rif, host->ipaddr);
 249                 host->cleanup_pending++;
 250                 uloop_timeout_set(&host->timeout, 1000);
 251                 return;
 252         }
 253         del_host(host);
 254 }
 255
 256 static struct relayd_host *add_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 257 {
 258         struct relayd_host *host;
 259         struct relayd_pending_route *route, *rtmp;
 260
 261         DPRINTF(1, "%s: adding host "IP_FMT" ("MAC_FMT")\n", rif->ifname,
 262                         IP_BUF(ipaddr), MAC_BUF(lladdr));
 263
 264         host = calloc(1, sizeof(*host));
 265         INIT_LIST_HEAD(&host->routes);
 266         host->rif = rif;
 267         memcpy(host->ipaddr, ipaddr, sizeof(host->ipaddr));
 268         memcpy(host->lladdr, lladdr, sizeof(host->lladdr));
 269         list_add(&host->list, &rif->hosts);
 270         host->timeout.cb = host_entry_timeout;
 271         uloop_timeout_set(&host->timeout, host_timeout * 1000);
 272
 273         add_arp(host);
 274         if (rif->managed)
 275                 relayd_add_route(host, NULL);
 276
 277         list_for_each_entry_safe(route, rtmp, &pending_routes, rt.list) {
 278                 if (memcmp(route->gateway, ipaddr, 4) != 0)
 279                         continue;
 280
 281                 relayd_add_host_route(host, route->rt.dest, route->rt.mask);
 282                 if (!route->timeout.pending)
 283                         continue;
 284
 285                 uloop_timeout_cancel(&route->timeout);
 286                 list_del(&route->rt.list);
 287                 free(route);
 288         }
 289
 290         return host;
 291 }
 292
 293 struct relayd_host *relayd_refresh_host(struct relayd_interface *rif, const uint8_t *lladdr, const uint8_t *ipaddr)
 294 {
 295         struct relayd_host *host;
 296
 297         host = find_host_by_ipaddr(rif, ipaddr);
 298         if (!host) {
 299                 host = find_host_by_ipaddr(NULL, ipaddr);
 300
 301                 /*
 302                  * When we suddenly see the host appearing on a different interface,
 303                  * reduce the timeout to make the old entry expire faster, in case the
 304                  * host has moved.
 305                  * If the old entry is behind a managed interface, it will be pinged
 306                  * before we expire it
 307                  */
 308                 if (host && !host->cleanup_pending) {
 309                         uloop_timeout_set(&host->timeout, 1);
 310                         return NULL;
 311                 }
 312
 313                 host = add_host(rif, lladdr, ipaddr);
 314         } else {
 315                 host->cleanup_pending = false;
 316                 uloop_timeout_set(&host->timeout, host_timeout * 1000);
 317         }
 318
 319         return host;
 320 }
 321
 322 static void relay_arp_request(struct relayd_interface *from_rif, struct arp_packet *pkt)
 323 {
 324         struct relayd_interface *rif;
 325         struct arp_packet reqpkt;
 326
 327         memcpy(&reqpkt, pkt, sizeof(reqpkt));
 328         list_for_each_entry(rif, &interfaces, list) {
 329                 if (rif == from_rif)
 330                         continue;
 331
 332                 memcpy(reqpkt.eth.ether_shost, rif->sll.sll_addr, ETH_ALEN);
 333                 memcpy(reqpkt.arp.arp_sha, rif->sll.sll_addr, ETH_ALEN);
 334
 335                 DPRINTF(2, "%s: sending ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
 336                         rif->ifname, IP_BUF(reqpkt.arp.arp_tpa),
 337                         IP_BUF(reqpkt.arp.arp_spa), MAC_BUF(reqpkt.eth.ether_shost));
 338
 339                 sendto(rif->fd.fd, &reqpkt, sizeof(reqpkt), 0,
 340                         (struct sockaddr *) &rif->sll, sizeof(rif->sll));
 341         }
 342 }
 343
 344 static void recv_arp_request(struct relayd_interface *rif, struct arp_packet *pkt)
 345 {
 346         struct relayd_host *host;
 347
 348         DPRINTF(2, "%s: ARP who-has "IP_FMT", tell "IP_FMT" ("MAC_FMT")\n",
 349                 rif->ifname,
 350                 IP_BUF(pkt->arp.arp_tpa),
 351                 IP_BUF(pkt->arp.arp_spa),
 352                 MAC_BUF(pkt->eth.ether_shost));
 353
 354         if (!memcmp(pkt->arp.arp_spa, "\x00\x00\x00\x00", 4))
 355                 return;
 356
 357         if (local_route_table && !memcmp(pkt->arp.arp_tpa, local_addr, sizeof(local_addr))) {
 358                 send_arp_reply(rif, local_addr, pkt->arp.arp_sha, pkt->arp.arp_spa);
 359                 return;
 360         }
 361
 362         relayd_refresh_host(rif, pkt->eth.ether_shost, pkt->arp.arp_spa);
 363
 364         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 365
 366         /*
 367          * If a host is being pinged because of a timeout, do not use the cached
 368          * entry here. That way we can avoid giving out stale data in case the node
 369          * has moved. We shouldn't relay requests here either, as we might miss our
 370          * chance to create a host route.
 371          */
 372         if (host && host->cleanup_pending)
 373                 return;
 374
 375         relay_arp_request(rif, pkt);
 376 }
 377
 378
 379 static void recv_arp_reply(struct relayd_interface *rif, struct arp_packet *pkt)
 380 {
 381         struct relayd_interface *to_rif;
 382         struct relayd_host *host;
 383
 384         DPRINTF(2, "%s: received ARP reply for "IP_FMT" from "MAC_FMT", deliver to "IP_FMT"\n",
 385                 rif->ifname,
 386                 IP_BUF(pkt->arp.arp_spa),
 387                 MAC_BUF(pkt->eth.ether_shost),
 388                 IP_BUF(pkt->arp.arp_tpa));
 389
 390         if (memcmp(pkt->arp.arp_sha, rif->sll.sll_addr, ETH_ALEN) != 0)
 391                 relayd_refresh_host(rif, pkt->arp.arp_sha, pkt->arp.arp_spa);
 392
 393         if (!memcmp(pkt->arp.arp_tpa, rif->src_ip, 4)) {
 394                 /*
 395                  * locally initiated lookup, relay as gratuitous ARP
 396                  * to all other interfaces
 397                  */
 398                 list_for_each_entry(to_rif, &interfaces, list) {
 399                         if (rif == to_rif)
 400                                 continue;
 401
 402                         send_arp_reply(to_rif, pkt->arp.arp_spa, NULL, pkt->arp.arp_spa);
 403                 }
 404                 return;
 405         }
 406
 407         host = find_host_by_ipaddr(NULL, pkt->arp.arp_tpa);
 408         if (!host)
 409                 return;
 410
 411         if (host->rif == rif)
 412                 return;
 413
 414         send_arp_reply(host->rif, pkt->arp.arp_spa, host->lladdr, host->ipaddr);
 415 }
 416
 417 static void recv_packet(struct uloop_fd *fd, unsigned int events)
 418 {
 419         struct relayd_interface *rif = container_of(fd, struct relayd_interface, fd);
 420         struct arp_packet *pkt;
 421         static char pktbuf[4096];
 422         int pktlen;
 423
 424         do {
 425                 if (rif->fd.error)
 426                         uloop_end();
 427
 428                 pktlen = recv(rif->fd.fd, pktbuf, sizeof(pktbuf), 0);
 429                 if (pktlen < 0) {
 430                         if (errno == EINTR)
 431                                 continue;
 432
 433                         break;
 434                 }
 435
 436                 if (!pktlen)
 437                         break;
 438
 439                 pkt = (void *)pktbuf;
 440                 if (pkt->arp.arp_op == htons(ARPOP_REPLY))
 441                         recv_arp_reply(rif, pkt);
 442                 else if (pkt->arp.arp_op == htons(ARPOP_REQUEST))
 443                         recv_arp_request(rif, pkt);
 444                 else
 445                         DPRINTF(1, "received unknown packet type: %04x\n", ntohs(pkt->arp.arp_op));
 446
 447         } while (1);
 448 }
 449
 450 void relayd_forward_bcast_packet(struct relayd_interface *from_rif, void *packet, int len)
 451 {
 452         struct relayd_interface *rif;
 453         struct ether_header *eth = packet;
 454
 455         list_for_each_entry(rif, &interfaces, list) {
 456                 if (rif == from_rif)
 457                         continue;
 458
 459                 DPRINTF(3, "%s: forwarding broadcast packet to %s\n", from_rif->ifname, rif->ifname);
 460                 memcpy(eth->ether_shost, rif->sll.sll_addr, ETH_ALEN);
 461                 send(rif->bcast_fd.fd, packet, len, 0);
 462         }
 463 }
 464
 465 static void recv_bcast_packet(struct uloop_fd *fd, unsigned int events)
 466 {
 467         struct relayd_interface *rif = container_of(fd, struct relayd_interface, bcast_fd);
 468         static char pktbuf[4096];
 469         int pktlen;
 470
 471         do {
 472                 if (rif->fd.error)
 473                         uloop_end();
 474
 475                 pktlen = recv(rif->bcast_fd.fd, pktbuf, sizeof(pktbuf), 0);
 476                 if (pktlen < 0) {
 477                         if (errno == EINTR)
 478                                 continue;
 479
 480                         break;
 481                 }
 482
 483                 if (!pktlen)
 484                         break;
 485
 486                 if (!forward_bcast && !forward_dhcp)
 487                         continue;
 488
 489                 if (relayd_handle_dhcp_packet(rif, pktbuf, pktlen, forward_dhcp))
 490                         continue;
 491
 492                 if (forward_bcast)
 493                         relayd_forward_bcast_packet(rif, pktbuf, pktlen);
 494         } while (1);
 495 }
 496
 497
 498 static int init_interface(struct relayd_interface *rif)
 499 {
 500         struct sockaddr_ll *sll = &rif->sll;
 501         struct sockaddr_in *sin;
 502         struct ifreq ifr;
 503         int fd = rif->fd.fd;
 504 #ifdef PACKET_RECV_TYPE
 505         unsigned int pkt_type;
 506 #endif
 507
 508         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ARP));
 509         if (fd < 0)
 510                 return -1;
 511
 512         rif->fd.fd = fd;
 513
 514         memset(&ifr, 0, sizeof(ifr));
 515         strcpy(ifr.ifr_name, rif->ifname);
 516
 517         if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
 518                 perror("ioctl(SIOCGIFHWADDR)");
 519                 return -1;
 520         }
 521
 522         memcpy(sll->sll_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
 523         sll->sll_family = AF_PACKET;
 524         sll->sll_protocol = htons(ETH_P_ARP);
 525         sll->sll_pkttype = PACKET_BROADCAST;
 526         sll->sll_hatype = ARPHRD_ETHER;
 527         sll->sll_halen = ETH_ALEN;
 528
 529         if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
 530                 perror("ioctl(SIOCGIFINDEX)");
 531                 return -1;
 532         }
 533
 534         sll->sll_ifindex = ifr.ifr_ifindex;
 535
 536         if (ioctl(fd, SIOCGIFADDR, &ifr) < 0) {
 537                 memcpy(rif->src_ip, DUMMY_IP, sizeof(rif->src_ip));
 538         } else {
 539                 sin = (struct sockaddr_in *) &ifr.ifr_addr;
 540                 memcpy(rif->src_ip, &sin->sin_addr.s_addr, sizeof(rif->src_ip));
 541         }
 542
 543         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 544                 perror("bind(ETH_P_ARP)");
 545                 return -1;
 546         }
 547
 548         rif->fd.cb = recv_packet;
 549         uloop_fd_add(&rif->fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 550
 551         if (!forward_bcast && !forward_dhcp)
 552                 return 0;
 553
 554         fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));
 555         if (fd < 0)
 556                 return 0;
 557
 558         rif->bcast_fd.fd = fd;
 559         rif->bcast_fd.cb = recv_bcast_packet;
 560
 561         memcpy(&rif->bcast_sll, &rif->sll, sizeof(rif->bcast_sll));
 562         sll = &rif->bcast_sll;
 563         sll->sll_protocol = htons(ETH_P_IP);
 564
 565         if (bind(fd, (struct sockaddr *)sll, sizeof(struct sockaddr_ll)) < 0) {
 566                 perror("bind(ETH_P_IP)");
 567                 return 0;
 568         }
 569
 570 #ifdef PACKET_RECV_TYPE
 571         pkt_type = (1 << PACKET_BROADCAST);
 572         setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &pkt_type, sizeof(pkt_type));
 573 #endif
 574
 575         uloop_fd_add(&rif->bcast_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 576         relayd_add_interface_routes(rif);
 577         return 0;
 578 }
 579
 580 static void ping_static_routes(void)
 581 {
 582         struct relayd_pending_route *rt;
 583         struct relayd_interface *rif;
 584
 585         list_for_each_entry(rt, &pending_routes, rt.list)
 586                 list_for_each_entry(rif, &interfaces, list)
 587                         send_arp_request(rif, rt->gateway);
 588 }
 589
 590 static int init_interfaces(void)
 591 {
 592         struct relayd_interface *rif;
 593         int ret;
 594
 595         list_for_each_entry(rif, &interfaces, list) {
 596                 ret = init_interface(rif);
 597                 if (ret < 0)
 598                         return ret;
 599         }
 600
 601         return 0;
 602 }
 603
 604 static void cleanup_hosts(void)
 605 {
 606         struct relayd_interface *rif;
 607         struct relayd_host *host, *tmp;
 608
 609         list_for_each_entry(rif, &interfaces, list) {
 610                 list_for_each_entry_safe(host, tmp, &rif->hosts, list) {
 611                         del_host(host);
 612                 }
 613         }
 614 }
 615
 616 static void free_interfaces(void)
 617 {
 618         struct relayd_interface *rif, *rtmp;
 619
 620         list_for_each_entry_safe(rif, rtmp, &interfaces, list) {
 621                 relayd_del_interface_routes(rif);
 622                 list_del(&rif->list);
 623                 free(rif);
 624         }
 625 }
 626
 627 static struct relayd_interface *alloc_interface(const char *ifname, bool managed)
 628 {
 629         struct relayd_interface *rif;
 630
 631         if (strlen(ifname) >= IFNAMSIZ)
 632                 return NULL;
 633
 634         rif = calloc(1, sizeof(*rif));
 635         if (!rif)
 636                 return NULL;
 637
 638         INIT_LIST_HEAD(&rif->hosts);
 639         strcpy(rif->ifname, ifname);
 640         list_add(&rif->list, &interfaces);
 641         rif->managed = managed;
 642
 643         return rif;
 644 }
 645
 646 static void die(int signo)
 647 {
 648         /*
 649          * When we hit SIGTERM, clean up interfaces directly, so that we
 650          * won't leave our routing in an invalid state.
 651          */
 652         cleanup_hosts();
 653         free_interfaces();
 654         exit(1);
 655 }
 656
 657 static int usage(const char *progname)
 658 {
 659         fprintf(stderr, "Usage: %s <options>\n"
 660                         "\n"
 661                         "Options:\n"
 662                         "       -d              Enable debug messages\n"
 663                         "       -i <ifname>     Add an interface for relaying\n"
 664                         "       -I <ifname>     Same as -i, except with ARP cache and host route management\n"
 665                         "                       You need to specify at least two interfaces\n"
 666                         "       -G <ip>         Set a gateway IP for clients\n"
 667                         "       -R <gateway>:<net>/<mask>\n"
 668                         "                       Add a static route for <net>/<mask> via <gateway>\n"
 669                         "       -t <timeout>    Host entry expiry timeout\n"
 670                         "       -T <table>      Set routing table number for automatically added routes\n"
 671                         "       -B              Enable broadcast forwarding\n"
 672                         "       -D              Enable DHCP forwarding\n"
 673                         "       -L <ipaddr>     Enable local access using <ipaddr> as source address\n"
 674                         "\n",
 675                 progname);
 676         return -1;
 677 }
 678
 679 int main(int argc, char **argv)
 680 {
 681         struct relayd_interface *rif = NULL;
 682         struct in_addr addr, addr2;
 683         bool local_addr_valid = false;
 684         bool managed;
 685         int ifnum = 0;
 686         char *s, *s2;
 687         int mask;
 688         int ch;
 689
 690         debug = 0;
 691         inet_sock = socket(AF_INET, SOCK_DGRAM, 0);
 692         if (inet_sock < 0) {
 693                 perror("socket(AF_INET)");
 694                 return 1;
 695         }
 696
 697         host_timeout = 60;
 698         forward_bcast = 0;
 699         local_route_table = 0;
 700         uloop_init();
 701
 702         while ((ch = getopt(argc, argv, "I:i:t:BDdT:G:R:L:")) != -1) {
 703                 switch(ch) {
 704                 case 'I':
 705                         managed = true;
 706                         /* fall through */
 707                 case 'i':
 708                         ifnum++;
 709                         rif = alloc_interface(optarg, managed);
 710                         if (!rif)
 711                                 return 1;
 712
 713                         managed = false;
 714                         break;
 715                 case 't':
 716                         host_timeout = atoi(optarg);
 717                         if (host_timeout <= 0)
 718                                 return usage(argv[0]);
 719                         break;
 720                 case 'd':
 721                         debug++;
 722                         break;
 723                 case 'B':
 724                         forward_bcast = 1;
 725                         break;
 726                 case 'D':
 727                         forward_dhcp = 1;
 728                         break;
 729                 case 'T':
 730                         route_table = atoi(optarg);
 731                         if (route_table <= 0)
 732                                 return usage(argv[0]);
 733                         break;
 734                 case 'G':
 735                         if (!inet_aton(optarg, &addr)) {
 736                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 737                                 return 1;
 738                         }
 739                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (const uint8_t *) "\x00\x00\x00\x00", 0, 0);
 740                         break;
 741                 case 'L':
 742                         if (!inet_aton(optarg, &addr)) {
 743                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 744                                 return 1;
 745                         }
 746                         memcpy(&local_addr, &addr.s_addr, sizeof(local_addr));
 747                         local_addr_valid = true;
 748                         break;
 749                 case 'R':
 750                         s = strchr(optarg, ':');
 751                         if (!s)
 752                                 return usage(argv[0]);
 753
 754                         *(s++) = 0;
 755                         if (!inet_aton(optarg, &addr)) {
 756                                 fprintf(stderr, "Address '%s' not found\n", optarg);
 757                                 return 1;
 758                         }
 759
 760                         s2 = strchr(s, '/');
 761                         if (!s2)
 762                                 return usage(argv[0]);
 763
 764                         *(s2++) = 0;
 765                         if (!inet_aton(s, &addr2)) {
 766                                 fprintf(stderr, "Address '%s' not found\n", s);
 767                                 return 1;
 768                         }
 769
 770                         mask = atoi(s2);
 771                         if (mask < 0 || mask > 32)
 772                                 return usage(argv[0]);
 773
 774                         relayd_add_pending_route((uint8_t *) &addr.s_addr, (uint8_t *) &addr2.s_addr, mask, 0);
 775                         break;
 776                 case '?':
 777                 default:
 778                         return usage(argv[0]);
 779                 }
 780         }
 781
 782         if (list_empty(&interfaces))
 783                 return usage(argv[0]);
 784
 785         if (ifnum < 2) {
 786                 fprintf(stderr, "ERROR: Need at least 2 interfaces for relaying\n");
 787                 return -1;
 788         }
 789
 790         argc -= optind;
 791         argv += optind;
 792
 793         signal(SIGTERM, die);
 794         signal(SIGHUP, die);
 795         signal(SIGUSR1, die);
 796         signal(SIGUSR2, die);
 797
 798         if (local_addr_valid)
 799                 local_route_table = route_table++;
 800
 801         if (relayd_rtnl_init() < 0)
 802                 return 1;
 803
 804         if (init_interfaces() < 0)
 805                 return 1;
 806
 807         ping_static_routes();
 808
 809         uloop_run();
 810         uloop_done();
 811
 812         cleanup_hosts();
 813         free_interfaces();
 814         relayd_rtnl_done();
 815         close(inet_sock);
 816
 817         return 0;
 818 }