external/bsd/dhcp/dist/common/bpf.c

   1 /*      $NetBSD: bpf.c,v 1.3 2014/07/12 12:09:37 spz Exp $      */
   2 /* bpf.c
   3
   4    BPF socket interface code, originally contributed by Archie Cobbs. */
   5
   6 /*
   7  * Copyright (c) 2009,2012-2014 by Internet Systems Consortium, Inc. ("ISC")
   8  * Copyright (c) 2004,2007 by Internet Systems Consortium, Inc. ("ISC")
   9  * Copyright (c) 1996-2003 by Internet Software Consortium
  10  *
  11  * Permission to use, copy, modify, and distribute this software for any
  12  * purpose with or without fee is hereby granted, provided that the above
  13  * copyright notice and this permission notice appear in all copies.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  16  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  17  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  18  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  19  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  20  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  21  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  22  *
  23  *   Internet Systems Consortium, Inc.
  24  *   950 Charter Street
  25  *   Redwood City, CA 94063
  26  *   <info@isc.org>
  27  *   https://www.isc.org/
  28  *
  29  * This software was contributed to Internet Systems Consortium
  30  * by Archie Cobbs.
  31  *
  32  * Patches for FDDI support on Digital Unix were written by Bill
  33  * Stapleton, and maintained for a while by Mike Meredith before he
  34  * managed to get me to integrate them.
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __RCSID("$NetBSD: bpf.c,v 1.3 2014/07/12 12:09:37 spz Exp $");
  39
  40 #include "dhcpd.h"
  41 #if defined (USE_BPF_SEND) || defined (USE_BPF_RECEIVE) \
  42                                 || defined (USE_LPF_RECEIVE)
  43 # if defined (USE_LPF_RECEIVE)
  44 #  include <asm/types.h>
  45 #  include <linux/filter.h>
  46 #  define bpf_insn sock_filter /* Linux: dare to be gratuitously different. */
  47 # else
  48 #  include <sys/ioctl.h>
  49 #  include <sys/uio.h>
  50 #  include <net/bpf.h>
  51 #  if defined (NEED_OSF_PFILT_HACKS)
  52 #   include <net/pfilt.h>
  53 #  endif
  54 # endif
  55
  56 #include <sys/param.h>
  57 #include <netinet/in_systm.h>
  58 #include "includes/netinet/ip.h"
  59 #include "includes/netinet/udp.h"
  60 #include "includes/netinet/if_ether.h"
  61 #endif
  62
  63 #if defined(USE_BPF_SEND) || defined(USE_BPF_RECEIVE) || defined(USE_BPF_HWADDR)
  64 #include <net/if_types.h>
  65 #include <ifaddrs.h>
  66 #endif
  67
  68 #include <errno.h>
  69
  70 /* Reinitializes the specified interface after an address change.   This
  71    is not required for packet-filter APIs. */
  72
  73 #ifdef USE_BPF_SEND
  74 void if_reinitialize_send (info)
  75         struct interface_info *info;
  76 {
  77 }
  78 #endif
  79
  80 #ifdef USE_BPF_RECEIVE
  81 void if_reinitialize_receive (info)
  82         struct interface_info *info;
  83 {
  84 }
  85 #endif
  86
  87 /* Called by get_interface_list for each interface that's discovered.
  88    Opens a packet filter for each interface and adds it to the select
  89    mask. */
  90
  91 #if defined (USE_BPF_SEND) || defined (USE_BPF_RECEIVE)
  92 int if_register_bpf (info)
  93         struct interface_info *info;
  94 {
  95         int sock;
  96         char filename[50];
  97         int b;
  98
  99         /* Open a BPF device */
 100         for (b = 0; 1; b++) {
 101                 /* %Audit% 31 bytes max. %2004.06.17,Safe% */
 102                 sprintf(filename, BPF_FORMAT, b);
 103                 sock = open (filename, O_RDWR, 0);
 104                 if (sock < 0) {
 105                         if (errno == EBUSY) {
 106                                 continue;
 107                         } else {
 108                                 if (!b)
 109                                         log_fatal ("No bpf devices.%s%s%s",
 110                                                "   Please read the README",
 111                                                " section for your operating",
 112                                                " system.");
 113                                 log_fatal ("Can't find free bpf: %m");
 114                         }
 115                 } else {
 116                         break;
 117                 }
 118         }
 119
 120         /* Set the BPF device to point at this interface. */
 121         if (ioctl (sock, BIOCSETIF, info -> ifp) < 0)
 122                 log_fatal ("Can't attach interface %s to bpf device %s: %m",
 123                        info -> name, filename);
 124
 125         get_hw_addr(info->name, &info->hw_address);
 126
 127         return sock;
 128 }
 129 #endif /* USE_BPF_SEND || USE_BPF_RECEIVE */
 130
 131 #ifdef USE_BPF_SEND
 132 void if_register_send (info)
 133         struct interface_info *info;
 134 {
 135         /* If we're using the bpf API for sending and receiving,
 136            we don't need to register this interface twice. */
 137 #ifndef USE_BPF_RECEIVE
 138         info -> wfdesc = if_register_bpf (info, interface);
 139 #else
 140         info -> wfdesc = info -> rfdesc;
 141 #endif
 142         if (!quiet_interface_discovery)
 143                 log_info ("Sending on   BPF/%s/%s%s%s",
 144                       info -> name,
 145                       print_hw_addr (info -> hw_address.hbuf [0],
 146                                      info -> hw_address.hlen - 1,
 147                                      &info -> hw_address.hbuf [1]),
 148                       (info -> shared_network ? "/" : ""),
 149                       (info -> shared_network ?
 150                        info -> shared_network -> name : ""));
 151 }
 152
 153 void if_deregister_send (info)
 154         struct interface_info *info;
 155 {
 156         /* If we're using the bpf API for sending and receiving,
 157            we don't need to register this interface twice. */
 158 #ifndef USE_BPF_RECEIVE
 159         close (info -> wfdesc);
 160 #endif
 161         info -> wfdesc = -1;
 162
 163         if (!quiet_interface_discovery)
 164                 log_info ("Disabling output on BPF/%s/%s%s%s",
 165                       info -> name,
 166                       print_hw_addr (info -> hw_address.hbuf [0],
 167                                      info -> hw_address.hlen - 1,
 168                                      &info -> hw_address.hbuf [1]),
 169                       (info -> shared_network ? "/" : ""),
 170                       (info -> shared_network ?
 171                        info -> shared_network -> name : ""));
 172 }
 173 #endif /* USE_BPF_SEND */
 174
 175 #if defined (USE_BPF_RECEIVE) || defined (USE_LPF_RECEIVE)
 176 /* Packet filter program...
 177    XXX Changes to the filter program may require changes to the constant
 178    offsets used in if_register_send to patch the BPF program! XXX */
 179
 180 struct bpf_insn dhcp_bpf_filter [] = {
 181         /* Make sure this is an IP packet... */
 182         BPF_STMT (BPF_LD + BPF_H + BPF_ABS, 12),
 183         BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 0, 8),
 184
 185         /* Make sure it's a UDP packet... */
 186         BPF_STMT (BPF_LD + BPF_B + BPF_ABS, 23),
 187         BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 0, 6),
 188
 189         /* Make sure this isn't a fragment... */
 190         BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 20),
 191         BPF_JUMP(BPF_JMP + BPF_JSET + BPF_K, 0x1fff, 4, 0),
 192
 193         /* Get the IP header length... */
 194         BPF_STMT (BPF_LDX + BPF_B + BPF_MSH, 14),
 195
 196         /* Make sure it's to the right port... */
 197         BPF_STMT (BPF_LD + BPF_H + BPF_IND, 16),
 198         BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, 67, 0, 1),             /* patch */
 199
 200         /* If we passed all the tests, ask for the whole packet. */
 201         BPF_STMT(BPF_RET+BPF_K, (u_int)-1),
 202
 203         /* Otherwise, drop it. */
 204         BPF_STMT(BPF_RET+BPF_K, 0),
 205 };
 206
 207 #if defined (DEC_FDDI)
 208 struct bpf_insn *bpf_fddi_filter;
 209 #endif
 210
 211 int dhcp_bpf_filter_len = sizeof dhcp_bpf_filter / sizeof (struct bpf_insn);
 212 #if defined (HAVE_TR_SUPPORT)
 213 struct bpf_insn dhcp_bpf_tr_filter [] = {
 214         /* accept all token ring packets due to variable length header */
 215         /* if we want to get clever, insert the program here */
 216
 217         /* If we passed all the tests, ask for the whole packet. */
 218         BPF_STMT(BPF_RET+BPF_K, (u_int)-1),
 219
 220         /* Otherwise, drop it. */
 221         BPF_STMT(BPF_RET+BPF_K, 0),
 222 };
 223
 224 int dhcp_bpf_tr_filter_len = (sizeof dhcp_bpf_tr_filter /
 225                               sizeof (struct bpf_insn));
 226 #endif /* HAVE_TR_SUPPORT */
 227 #endif /* USE_LPF_RECEIVE || USE_BPF_RECEIVE */
 228
 229 #if defined (USE_BPF_RECEIVE)
 230 void if_register_receive (info)
 231         struct interface_info *info;
 232 {
 233         int flag = 1;
 234         struct bpf_version v;
 235         struct bpf_program p;
 236 #ifdef NEED_OSF_PFILT_HACKS
 237         u_int32_t bits;
 238 #endif
 239 #ifdef DEC_FDDI
 240         int link_layer;
 241 #endif /* DEC_FDDI */
 242
 243         /* Open a BPF device and hang it on this interface... */
 244         info -> rfdesc = if_register_bpf (info);
 245
 246         /* Make sure the BPF version is in range... */
 247         if (ioctl (info -> rfdesc, BIOCVERSION, &v) < 0)
 248                 log_fatal ("Can't get BPF version: %m");
 249
 250         if (v.bv_major != BPF_MAJOR_VERSION ||
 251             v.bv_minor < BPF_MINOR_VERSION)
 252                 log_fatal ("BPF version mismatch - recompile DHCP!");
 253
 254         /* Set immediate mode so that reads return as soon as a packet
 255            comes in, rather than waiting for the input buffer to fill with
 256            packets. */
 257         if (ioctl (info -> rfdesc, BIOCIMMEDIATE, &flag) < 0)
 258                 log_fatal ("Can't set immediate mode on bpf device: %m");
 259
 260 #ifdef NEED_OSF_PFILT_HACKS
 261         /* Allow the copyall flag to be set... */
 262         if (ioctl(info -> rfdesc, EIOCALLOWCOPYALL, &flag) < 0)
 263                 log_fatal ("Can't set ALLOWCOPYALL: %m");
 264
 265         /* Clear all the packet filter mode bits first... */
 266         bits = 0;
 267         if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0)
 268                 log_fatal ("Can't clear pfilt bits: %m");
 269
 270         /* Set the ENBATCH, ENCOPYALL, ENBPFHDR bits... */
 271         bits = ENBATCH | ENCOPYALL | ENBPFHDR;
 272         if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0)
 273                 log_fatal ("Can't set ENBATCH|ENCOPYALL|ENBPFHDR: %m");
 274 #endif
 275         /* Get the required BPF buffer length from the kernel. */
 276         if (ioctl (info -> rfdesc, BIOCGBLEN, &info -> rbuf_max) < 0)
 277                 log_fatal ("Can't get bpf buffer length: %m");
 278         info -> rbuf = dmalloc (info -> rbuf_max, MDL);
 279         if (!info -> rbuf)
 280                 log_fatal ("Can't allocate %ld bytes for bpf input buffer.",
 281                            (long)(info -> rbuf_max));
 282         info -> rbuf_offset = 0;
 283         info -> rbuf_len = 0;
 284
 285         /* Set up the bpf filter program structure. */
 286         p.bf_len = dhcp_bpf_filter_len;
 287
 288 #ifdef DEC_FDDI
 289         /* See if this is an FDDI interface, flag it for later. */
 290         if (ioctl(info -> rfdesc, BIOCGDLT, &link_layer) >= 0 &&
 291             link_layer == DLT_FDDI) {
 292                 if (!bpf_fddi_filter) {
 293                         bpf_fddi_filter = dmalloc (sizeof bpf_fddi_filter,
 294                                                     MDL);
 295                         if (!bpf_fddi_filter)
 296                                 log_fatal ("No memory for FDDI filter.");
 297                         memcpy (bpf_fddi_filter,
 298                                 dhcp_bpf_filter, sizeof dhcp_bpf_filter);
 299                         /* Patch the BPF program to account for the difference
 300                            in length between ethernet headers (14), FDDI and
 301                            802.2 headers (16 +8=24, +10).
 302                            XXX changes to filter program may require changes to
 303                            XXX the insn number(s) used below! */
 304                         bpf_fddi_filter[0].k += 10;
 305                         bpf_fddi_filter[2].k += 10;
 306                         bpf_fddi_filter[4].k += 10;
 307                         bpf_fddi_filter[6].k += 10;
 308                         bpf_fddi_filter[7].k += 10;
 309                 }
 310                 p.bf_insns = bpf_fddi_filter;
 311         } else
 312 #endif /* DEC_FDDI */
 313         p.bf_insns = dhcp_bpf_filter;
 314
 315         /* Patch the server port into the BPF  program...
 316            XXX changes to filter program may require changes
 317            to the insn number(s) used below! XXX */
 318         dhcp_bpf_filter [8].k = ntohs (local_port);
 319
 320         if (ioctl (info -> rfdesc, BIOCSETF, &p) < 0)
 321                 log_fatal ("Can't install packet filter program: %m");
 322         if (!quiet_interface_discovery)
 323                 log_info ("Listening on BPF/%s/%s%s%s",
 324                       info -> name,
 325                       print_hw_addr (info -> hw_address.hbuf [0],
 326                                      info -> hw_address.hlen - 1,
 327                                      &info -> hw_address.hbuf [1]),
 328                       (info -> shared_network ? "/" : ""),
 329                       (info -> shared_network ?
 330                        info -> shared_network -> name : ""));
 331 }
 332
 333 void if_deregister_receive (info)
 334         struct interface_info *info;
 335 {
 336         close (info -> rfdesc);
 337         info -> rfdesc = -1;
 338
 339         if (!quiet_interface_discovery)
 340                 log_info ("Disabling input on BPF/%s/%s%s%s",
 341                       info -> name,
 342                       print_hw_addr (info -> hw_address.hbuf [0],
 343                                      info -> hw_address.hlen - 1,
 344                                      &info -> hw_address.hbuf [1]),
 345                       (info -> shared_network ? "/" : ""),
 346                       (info -> shared_network ?
 347                        info -> shared_network -> name : ""));
 348 }
 349 #endif /* USE_BPF_RECEIVE */
 350
 351 #ifdef USE_BPF_SEND
 352 ssize_t send_packet (interface, packet, raw, len, from, to, hto)
 353         struct interface_info *interface;
 354         struct packet *packet;
 355         struct dhcp_packet *raw;
 356         size_t len;
 357         struct in_addr from;
 358         struct sockaddr_in *to;
 359         struct hardware *hto;
 360 {
 361         unsigned hbufp = 0, ibufp = 0;
 362         double hw [4];
 363         double ip [32];
 364         struct iovec iov [3];
 365         int result;
 366
 367         if (!strcmp (interface -> name, "fallback"))
 368                 return send_fallback (interface, packet, raw,
 369                                       len, from, to, hto);
 370
 371         if (hto == NULL && interface->anycast_mac_addr.hlen)
 372                 hto = &interface->anycast_mac_addr;
 373
 374         /* Assemble the headers... */
 375         assemble_hw_header (interface, (unsigned char *)hw, &hbufp, hto);
 376         assemble_udp_ip_header (interface,
 377                                 (unsigned char *)ip, &ibufp, from.s_addr,
 378                                 to -> sin_addr.s_addr, to -> sin_port,
 379                                 (unsigned char *)raw, len);
 380
 381         /* Fire it off */
 382         iov [0].iov_base = ((char *)hw);
 383         iov [0].iov_len = hbufp;
 384         iov [1].iov_base = ((char *)ip);
 385         iov [1].iov_len = ibufp;
 386         iov [2].iov_base = (char *)raw;
 387         iov [2].iov_len = len;
 388
 389         result = writev(interface -> wfdesc, iov, 3);
 390         if (result < 0)
 391                 log_error ("send_packet: %m");
 392         return result;
 393 }
 394 #endif /* USE_BPF_SEND */
 395
 396 #ifdef USE_BPF_RECEIVE
 397 ssize_t receive_packet (interface, buf, len, from, hfrom)
 398         struct interface_info *interface;
 399         unsigned char *buf;
 400         size_t len;
 401         struct sockaddr_in *from;
 402         struct hardware *hfrom;
 403 {
 404         int length = 0;
 405         int offset = 0;
 406         struct bpf_hdr hdr;
 407         unsigned paylen;
 408
 409         /* All this complexity is because BPF doesn't guarantee
 410            that only one packet will be returned at a time.   We're
 411            getting what we deserve, though - this is a terrible abuse
 412            of the BPF interface.   Sigh. */
 413
 414         /* Process packets until we get one we can return or until we've
 415            done a read and gotten nothing we can return... */
 416
 417         /* If the buffer is empty, fill it. */
 418         if (interface->rbuf_offset >= interface->rbuf_len) {
 419                 length = read(interface->rfdesc, interface->rbuf,
 420                               (size_t)interface->rbuf_max);
 421                 if (length <= 0) {
 422 #ifdef __FreeBSD__
 423                         if (errno == ENXIO) {
 424 #else
 425                         if (errno == EIO) {
 426 #endif
 427                                 dhcp_interface_remove
 428                                         ((omapi_object_t *)interface, NULL);
 429                         }
 430                         return (length);
 431                 }
 432                 interface->rbuf_offset = 0;
 433                 interface->rbuf_len = BPF_WORDALIGN(length);
 434         }
 435
 436         do {
 437                 /* If there isn't room for a whole bpf header, something went
 438                    wrong, but we'll ignore it and hope it goes away... XXX */
 439                 if (interface->rbuf_len -
 440                     interface->rbuf_offset < sizeof hdr) {
 441                         interface->rbuf_offset = interface->rbuf_len;
 442                         continue;
 443                 }
 444
 445                 /* Copy out a bpf header... */
 446                 memcpy(&hdr, &interface->rbuf[interface->rbuf_offset],
 447                        sizeof hdr);
 448
 449                 /* If the bpf header plus data doesn't fit in what's left
 450                    of the buffer, stick head in sand yet again... */
 451                 if (interface->rbuf_offset +
 452                     hdr.bh_hdrlen + hdr.bh_caplen > interface->rbuf_len) {
 453                         interface->rbuf_offset = interface->rbuf_len;
 454                         continue;
 455                 }
 456
 457                 /* If the captured data wasn't the whole packet, or if
 458                    the packet won't fit in the input buffer, all we
 459                    can do is drop it. */
 460                 if (hdr.bh_caplen != hdr.bh_datalen) {
 461                         interface->rbuf_offset =
 462                                 BPF_WORDALIGN(interface->rbuf_offset +
 463                                               hdr.bh_hdrlen + hdr.bh_caplen);
 464                         continue;
 465                 }
 466
 467                 /* Skip over the BPF header... */
 468                 interface->rbuf_offset += hdr.bh_hdrlen;
 469
 470                 /* Decode the physical header... */
 471                 offset = decode_hw_header(interface, interface->rbuf,
 472                                           interface->rbuf_offset, hfrom);
 473
 474                 /* If a physical layer checksum failed (dunno of any
 475                    physical layer that supports this, but WTH), skip this
 476                    packet. */
 477                 if (offset < 0) {
 478                         interface->rbuf_offset =
 479                                 BPF_WORDALIGN(interface->rbuf_offset +
 480                                               hdr.bh_caplen);
 481                         continue;
 482                 }
 483                 interface->rbuf_offset += offset;
 484                 hdr.bh_caplen -= offset;
 485
 486                 /* Decode the IP and UDP headers... */
 487                 offset = decode_udp_ip_header(interface, interface->rbuf,
 488                                                interface->rbuf_offset,
 489                                                from, hdr.bh_caplen, &paylen);
 490
 491                 /* If the IP or UDP checksum was bad, skip the packet... */
 492                 if (offset < 0) {
 493                         interface->rbuf_offset =
 494                                 BPF_WORDALIGN(interface->rbuf_offset +
 495                                               hdr.bh_caplen);
 496                         continue;
 497                 }
 498                 interface->rbuf_offset = interface->rbuf_offset + offset;
 499                 hdr.bh_caplen -= offset;
 500
 501                 /* If there's not enough room to stash the packet data,
 502                    we have to skip it (this shouldn't happen in real
 503                    life, though). */
 504                 if (hdr.bh_caplen > len) {
 505                         interface->rbuf_offset =
 506                                 BPF_WORDALIGN(interface->rbuf_offset +
 507                                                hdr.bh_caplen);
 508                         continue;
 509                 }
 510
 511                 /* Copy out the data in the packet... */
 512                 memcpy(buf, interface->rbuf + interface->rbuf_offset, paylen);
 513                 interface->rbuf_offset =
 514                         BPF_WORDALIGN(interface->rbuf_offset + hdr.bh_caplen);
 515                 return paylen;
 516         } while (interface->rbuf_offset < interface->rbuf_len);
 517
 518         return (0);
 519 }
 520
 521 int can_unicast_without_arp (ip)
 522         struct interface_info *ip;
 523 {
 524         return 1;
 525 }
 526
 527 int can_receive_unicast_unconfigured (ip)
 528         struct interface_info *ip;
 529 {
 530         return 1;
 531 }
 532
 533 int supports_multiple_interfaces (ip)
 534         struct interface_info *ip;
 535 {
 536         return 1;
 537 }
 538
 539 void maybe_setup_fallback ()
 540 {
 541         isc_result_t status;
 542         struct interface_info *fbi = (struct interface_info *)0;
 543         if (setup_fallback (&fbi, MDL)) {
 544                 if_register_fallback (fbi);
 545                 status = omapi_register_io_object ((omapi_object_t *)fbi,
 546                                                    if_readsocket, 0,
 547                                                    fallback_discard, 0, 0);
 548                 if (status != ISC_R_SUCCESS)
 549                         log_fatal ("Can't register I/O handle for %s: %s",
 550                                    fbi -> name, isc_result_totext (status));
 551                 interface_dereference (&fbi, MDL);
 552         }
 553 }
 554
 555 #endif
 556
 557 #if defined(USE_BPF_RECEIVE) || defined(USE_BPF_HWADDR)
 558 static int
 559 lladdr_active(int s, const char *name, const struct ifaddrs *ifa)
 560 {
 561         if (ifa->ifa_addr->sa_family != AF_LINK)
 562                 return 0;
 563         if (strcmp(ifa->ifa_name, name) != 0)
 564                 return 0;
 565
 566 #ifdef SIOCGLIFADDR
 567 {
 568         struct if_laddrreq iflr;
 569         const struct sockaddr_dl *sdl;
 570
 571         sdl = satocsdl(ifa->ifa_addr);
 572         memset(&iflr, 0, sizeof(iflr));
 573
 574         strlcpy(iflr.iflr_name, ifa->ifa_name, sizeof(iflr.iflr_name));
 575         memcpy(&iflr.addr, ifa->ifa_addr, MIN(ifa->ifa_addr->sa_len,
 576            sizeof(iflr.addr)));
 577         iflr.flags = IFLR_PREFIX;
 578         iflr.prefixlen = sdl->sdl_alen * NBBY;
 579
 580         if (ioctl(s, SIOCGLIFADDR, &iflr) == -1) {
 581                 log_fatal("ioctl(SIOCGLIFADDR): %m");
 582         }
 583
 584         if ((iflr.flags & IFLR_ACTIVE) == 0)
 585                 return 0;
 586 }
 587 #endif
 588         return 1;
 589 }
 590
 591 void
 592 get_hw_addr(const char *name, struct hardware *hw) {
 593         struct ifaddrs *ifa;
 594         struct ifaddrs *p;
 595         struct sockaddr_dl *sa;
 596         int s;
 597
 598         if ((s = socket(AF_LINK, SOCK_DGRAM, 0)) == -1) {
 599                 log_fatal("socket AF_LINK: %m");
 600         }
 601
 602         if (getifaddrs(&ifa) != 0) {
 603                 log_fatal("Error getting interface information; %m");
 604         }
 605
 606         /*
 607          * Loop through our interfaces finding a match.
 608          */
 609         sa = NULL;
 610         for (p = ifa; p != NULL; p = p->ifa_next) {
 611                 if (lladdr_active(s, name, p)) {
 612                         sa = (struct sockaddr_dl *)p->ifa_addr;
 613                         break;
 614                 }
 615         }
 616         if (sa == NULL) {
 617                 log_fatal("No interface called '%s'", name);
 618         }
 619         close(s);
 620
 621         /*
 622          * Pull out the appropriate information.
 623          */
 624         switch (sa->sdl_type) {
 625                 case IFT_ETHER:
 626                         hw->hlen = sa->sdl_alen + 1;
 627                         hw->hbuf[0] = HTYPE_ETHER;
 628                         memcpy(&hw->hbuf[1], LLADDR(sa), sa->sdl_alen);
 629                         break;
 630                 case IFT_ISO88023:
 631                 case IFT_ISO88024: /* "token ring" */
 632                 case IFT_ISO88025:
 633                 case IFT_ISO88026:
 634                         hw->hlen = sa->sdl_alen + 1;
 635                         hw->hbuf[0] = HTYPE_IEEE802;
 636                         memcpy(&hw->hbuf[1], LLADDR(sa), sa->sdl_alen);
 637                         break;
 638 #ifdef IFT_FDDI
 639                 case IFT_FDDI:
 640                         hw->hlen = sa->sdl_alen + 1;
 641                         hw->hbuf[0] = HTYPE_FDDI;
 642                         memcpy(&hw->hbuf[1], LLADDR(sa), sa->sdl_alen);
 643                         break;
 644 #endif /* IFT_FDDI */
 645                 default:
 646                         log_fatal("Unsupported device type %d for \"%s\"",
 647                                   sa->sdl_type, name);
 648         }
 649
 650         freeifaddrs(ifa);
 651 }
 652 #endif