The Tcpdump Group git mirrors - libpcap/blob - inet.c

   1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
   2 /*
   3  * Copyright (c) 1994, 1995, 1996, 1997, 1998
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the Computer Systems
  17  *      Engineering Group at Lawrence Berkeley Laboratory.
  18  * 4. Neither the name of the University nor of the Laboratory may be used
  19  *    to endorse or promote products derived from this software without
  20  *    specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifndef lint
  36 static const char rcsid[] _U_ =
  37     "@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.63 2004-12-18 08:52:09 guy Exp $ (LBL)";
  38 #endif
  39
  40 #ifdef HAVE_CONFIG_H
  41 #include "config.h"
  42 #endif
  43
  44 #ifdef WIN32
  45 #include <pcap-stdinc.h>
  46 #else /* WIN32 */
  47
  48 #include <sys/param.h>
  49 #ifndef MSDOS
  50 #include <sys/file.h>
  51 #endif
  52 #include <sys/ioctl.h>
  53 #include <sys/socket.h>
  54 #ifdef HAVE_SYS_SOCKIO_H
  55 #include <sys/sockio.h>
  56 #endif
  57
  58 struct mbuf;            /* Squelch compiler warnings on some platforms for */
  59 struct rtentry;         /* declarations in <net/if.h> */
  60 #include <net/if.h>
  61 #include <netinet/in.h>
  62 #endif /* WIN32 */
  63
  64 #include <ctype.h>
  65 #include <errno.h>
  66 #include <memory.h>
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70 #if !defined(WIN32) && !defined(__BORLANDC__)
  71 #include <unistd.h>
  72 #endif /* !WIN32 && !__BORLANDC__ */
  73 #ifdef HAVE_LIMITS_H
  74 #include <limits.h>
  75 #else
  76 #define INT_MAX         2147483647
  77 #endif
  78
  79 #include "pcap-int.h"
  80
  81 #ifdef HAVE_OS_PROTO_H
  82 #include "os-proto.h"
  83 #endif
  84
  85 /* Not all systems have IFF_LOOPBACK */
  86 #ifdef IFF_LOOPBACK
  87 #define ISLOOPBACK(name, flags) ((flags) & IFF_LOOPBACK)
  88 #else
  89 #define ISLOOPBACK(name, flags) ((name)[0] == 'l' && (name)[1] == 'o' && \
  90     (isdigit((unsigned char)((name)[2])) || (name)[2] == '\0'))
  91 #endif
  92
  93 struct sockaddr *
  94 dup_sockaddr(struct sockaddr *sa, size_t sa_length)
  95 {
  96         struct sockaddr *newsa;
  97
  98         if ((newsa = malloc(sa_length)) == NULL)
  99                 return (NULL);
 100         return (memcpy(newsa, sa, sa_length));
 101 }
 102
 103 static int
 104 get_instance(const char *name)
 105 {
 106         const char *cp, *endcp;
 107         int n;
 108
 109         if (strcmp(name, "any") == 0) {
 110                 /*
 111                  * Give the "any" device an artificially high instance
 112                  * number, so it shows up after all other non-loopback
 113                  * interfaces.
 114                  */
 115                 return INT_MAX;
 116         }
 117
 118         endcp = name + strlen(name);
 119         for (cp = name; cp < endcp && !isdigit((unsigned char)*cp); ++cp)
 120                 continue;
 121
 122         if (isdigit((unsigned char)*cp))
 123                 n = atoi(cp);
 124         else
 125                 n = 0;
 126         return (n);
 127 }
 128
 129 int
 130 add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
 131     u_int flags, const char *description, char *errbuf)
 132 {
 133         pcap_if_t *curdev, *prevdev, *nextdev;
 134         int this_instance;
 135
 136         /*
 137          * Is there already an entry in the list for this interface?
 138          */
 139         for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
 140                 if (strcmp(name, curdev->name) == 0)
 141                         break;  /* yes, we found it */
 142         }
 143         if (curdev == NULL) {
 144                 /*
 145                  * No, we didn't find it.
 146                  * Allocate a new entry.
 147                  */
 148                 curdev = malloc(sizeof(pcap_if_t));
 149                 if (curdev == NULL) {
 150                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 151                             "malloc: %s", pcap_strerror(errno));
 152                         return (-1);
 153                 }
 154
 155                 /*
 156                  * Fill in the entry.
 157                  */
 158                 curdev->next = NULL;
 159                 curdev->name = malloc(strlen(name) + 1);
 160                 strcpy(curdev->name, name);
 161                 if (description != NULL) {
 162                         /*
 163                          * We have a description for this interface.
 164                          */
 165                         curdev->description = malloc(strlen(description) + 1);
 166                         strcpy(curdev->description, description);
 167                 } else {
 168                         /*
 169                          * We don't.
 170                          */
 171                         curdev->description = NULL;
 172                 }
 173                 curdev->addresses = NULL;       /* list starts out as empty */
 174                 curdev->flags = 0;
 175                 if (ISLOOPBACK(name, flags))
 176                         curdev->flags |= PCAP_IF_LOOPBACK;
 177
 178                 /*
 179                  * Add it to the list, in the appropriate location.
 180                  * First, get the instance number of this interface.
 181                  */
 182                 this_instance = get_instance(name);
 183
 184                 /*
 185                  * Now look for the last interface with an instance number
 186                  * less than or equal to the new interface's instance
 187                  * number - except that non-loopback interfaces are
 188                  * arbitrarily treated as having interface numbers less
 189                  * than those of loopback interfaces, so the loopback
 190                  * interfaces are put at the end of the list.
 191                  *
 192                  * We start with "prevdev" being NULL, meaning we're before
 193                  * the first element in the list.
 194                  */
 195                 prevdev = NULL;
 196                 for (;;) {
 197                         /*
 198                          * Get the interface after this one.
 199                          */
 200                         if (prevdev == NULL) {
 201                                 /*
 202                                  * The next element is the first element.
 203                                  */
 204                                 nextdev = *alldevs;
 205                         } else
 206                                 nextdev = prevdev->next;
 207
 208                         /*
 209                          * Are we at the end of the list?
 210                          */
 211                         if (nextdev == NULL) {
 212                                 /*
 213                                  * Yes - we have to put the new entry
 214                                  * after "prevdev".
 215                                  */
 216                                 break;
 217                         }
 218
 219                         /*
 220                          * Is the new interface a non-loopback interface
 221                          * and the next interface a loopback interface?
 222                          */
 223                         if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
 224                             (nextdev->flags & PCAP_IF_LOOPBACK)) {
 225                                 /*
 226                                  * Yes, we should put the new entry
 227                                  * before "nextdev", i.e. after "prevdev".
 228                                  */
 229                                 break;
 230                         }
 231
 232                         /*
 233                          * Is the new interface's instance number less
 234                          * than the next interface's instance number,
 235                          * and is it the case that the new interface is a
 236                          * non-loopback interface or the next interface is
 237                          * a loopback interface?
 238                          *
 239                          * (The goal of both loopback tests is to make
 240                          * sure that we never put a loopback interface
 241                          * before any non-loopback interface and that we
 242                          * always put a non-loopback interface before all
 243                          * loopback interfaces.)
 244                          */
 245                         if (this_instance < get_instance(nextdev->name) &&
 246                             (!(curdev->flags & PCAP_IF_LOOPBACK) ||
 247                                (nextdev->flags & PCAP_IF_LOOPBACK))) {
 248                                 /*
 249                                  * Yes - we should put the new entry
 250                                  * before "nextdev", i.e. after "prevdev".
 251                                  */
 252                                 break;
 253                         }
 254
 255                         prevdev = nextdev;
 256                 }
 257
 258                 /*
 259                  * Insert before "nextdev".
 260                  */
 261                 curdev->next = nextdev;
 262
 263                 /*
 264                  * Insert after "prevdev" - unless "prevdev" is null,
 265                  * in which case this is the first interface.
 266                  */
 267                 if (prevdev == NULL) {
 268                         /*
 269                          * This is the first interface.  Pass back a
 270                          * pointer to it, and put "curdev" before
 271                          * "nextdev".
 272                          */
 273                         *alldevs = curdev;
 274                 } else
 275                         prevdev->next = curdev;
 276         }
 277
 278         *curdev_ret = curdev;
 279         return (0);
 280 }
 281
 282 int
 283 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
 284     struct sockaddr *addr, size_t addr_size,
 285     struct sockaddr *netmask, size_t netmask_size,
 286     struct sockaddr *broadaddr, size_t broadaddr_size,
 287     struct sockaddr *dstaddr, size_t dstaddr_size,
 288     char *errbuf)
 289 {
 290         pcap_if_t *curdev;
 291         pcap_addr_t *curaddr, *prevaddr, *nextaddr;
 292
 293         if (add_or_find_if(&curdev, alldevs, name, flags, NULL, errbuf) == -1) {
 294                 /*
 295                  * Error - give up.
 296                  */
 297                 return (-1);
 298         }
 299         if (curdev == NULL) {
 300                 /*
 301                  * Device wasn't added because it can't be opened.
 302                  * Not a fatal error.
 303                  */
 304                 return (0);
 305         }
 306
 307         /*
 308          * "curdev" is an entry for this interface; add an entry for this
 309          * address to its list of addresses.
 310          *
 311          * Allocate the new entry and fill it in.
 312          */
 313         curaddr = malloc(sizeof(pcap_addr_t));
 314         if (curaddr == NULL) {
 315                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 316                     "malloc: %s", pcap_strerror(errno));
 317                 return (-1);
 318         }
 319
 320         curaddr->next = NULL;
 321         if (addr != NULL) {
 322                 curaddr->addr = dup_sockaddr(addr, addr_size);
 323                 if (curaddr->addr == NULL) {
 324                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 325                             "malloc: %s", pcap_strerror(errno));
 326                         free(curaddr);
 327                         return (-1);
 328                 }
 329         } else
 330                 curaddr->addr = NULL;
 331
 332         if (netmask != NULL) {
 333                 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
 334                 if (curaddr->netmask == NULL) {
 335                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 336                             "malloc: %s", pcap_strerror(errno));
 337                         free(curaddr);
 338                         return (-1);
 339                 }
 340         } else
 341                 curaddr->netmask = NULL;
 342
 343         if (broadaddr != NULL) {
 344                 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
 345                 if (curaddr->broadaddr == NULL) {
 346                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 347                             "malloc: %s", pcap_strerror(errno));
 348                         free(curaddr);
 349                         return (-1);
 350                 }
 351         } else
 352                 curaddr->broadaddr = NULL;
 353
 354         if (dstaddr != NULL) {
 355                 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
 356                 if (curaddr->dstaddr == NULL) {
 357                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 358                             "malloc: %s", pcap_strerror(errno));
 359                         free(curaddr);
 360                         return (-1);
 361                 }
 362         } else
 363                 curaddr->dstaddr = NULL;
 364
 365         /*
 366          * Find the end of the list of addresses.
 367          */
 368         for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
 369                 nextaddr = prevaddr->next;
 370                 if (nextaddr == NULL) {
 371                         /*
 372                          * This is the end of the list.
 373                          */
 374                         break;
 375                 }
 376         }
 377
 378         if (prevaddr == NULL) {
 379                 /*
 380                  * The list was empty; this is the first member.
 381                  */
 382                 curdev->addresses = curaddr;
 383         } else {
 384                 /*
 385                  * "prevaddr" is the last member of the list; append
 386                  * this member to it.
 387                  */
 388                 prevaddr->next = curaddr;
 389         }
 390
 391         return (0);
 392 }
 393
 394 int
 395 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
 396     const char *description, char *errbuf)
 397 {
 398         pcap_if_t *curdev;
 399
 400         return (add_or_find_if(&curdev, devlist, name, flags, description,
 401             errbuf));
 402 }
 403
 404
 405 /*
 406  * Free a list of interfaces.
 407  */
 408 void
 409 pcap_freealldevs(pcap_if_t *alldevs)
 410 {
 411         pcap_if_t *curdev, *nextdev;
 412         pcap_addr_t *curaddr, *nextaddr;
 413
 414         for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
 415                 nextdev = curdev->next;
 416
 417                 /*
 418                  * Free all addresses.
 419                  */
 420                 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
 421                         nextaddr = curaddr->next;
 422                         if (curaddr->addr)
 423                                 free(curaddr->addr);
 424                         if (curaddr->netmask)
 425                                 free(curaddr->netmask);
 426                         if (curaddr->broadaddr)
 427                                 free(curaddr->broadaddr);
 428                         if (curaddr->dstaddr)
 429                                 free(curaddr->dstaddr);
 430                         free(curaddr);
 431                 }
 432
 433                 /*
 434                  * Free the name string.
 435                  */
 436                 free(curdev->name);
 437
 438                 /*
 439                  * Free the description string, if any.
 440                  */
 441                 if (curdev->description != NULL)
 442                         free(curdev->description);
 443
 444                 /*
 445                  * Free the interface.
 446                  */
 447                 free(curdev);
 448         }
 449 }
 450
 451 #if !defined(WIN32) && !defined(MSDOS)
 452
 453 /*
 454  * Return the name of a network interface attached to the system, or NULL
 455  * if none can be found.  The interface must be configured up; the
 456  * lowest unit number is preferred; loopback is ignored.
 457  */
 458 char *
 459 pcap_lookupdev(errbuf)
 460         register char *errbuf;
 461 {
 462         pcap_if_t *alldevs;
 463 /* for old BSD systems, including bsdi3 */
 464 #ifndef IF_NAMESIZE
 465 #define IF_NAMESIZE IFNAMSIZ
 466 #endif
 467         static char device[IF_NAMESIZE + 1];
 468         char *ret;
 469
 470         if (pcap_findalldevs(&alldevs, errbuf) == -1)
 471                 return (NULL);
 472
 473         if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
 474                 /*
 475                  * There are no devices on the list, or the first device
 476                  * on the list is a loopback device, which means there
 477                  * are no non-loopback devices on the list.  This means
 478                  * we can't return any device.
 479                  *
 480                  * XXX - why not return a loopback device?  If we can't
 481                  * capture on it, it won't be on the list, and if it's
 482                  * on the list, there aren't any non-loopback devices,
 483                  * so why not just supply it as the default device?
 484                  */
 485                 (void)strlcpy(errbuf, "no suitable device found",
 486                     PCAP_ERRBUF_SIZE);
 487                 ret = NULL;
 488         } else {
 489                 /*
 490                  * Return the name of the first device on the list.
 491                  */
 492                 (void)strlcpy(device, alldevs->name, sizeof(device));
 493                 ret = device;
 494         }
 495
 496         pcap_freealldevs(alldevs);
 497         return (ret);
 498 }
 499
 500 int
 501 pcap_lookupnet(device, netp, maskp, errbuf)
 502         register const char *device;
 503         register bpf_u_int32 *netp, *maskp;
 504         register char *errbuf;
 505 {
 506         register int fd;
 507         register struct sockaddr_in *sin;
 508         struct ifreq ifr;
 509
 510         /*
 511          * The pseudo-device "any" listens on all interfaces and therefore
 512          * has the network address and -mask "0.0.0.0" therefore catching
 513          * all traffic. Using NULL for the interface is the same as "any".
 514          */
 515         if (!device || strcmp(device, "any") == 0
 516 #ifdef HAVE_DAG_API
 517             || strstr(device, "dag") != NULL
 518 #endif
 519             ) {
 520                 *netp = *maskp = 0;
 521                 return 0;
 522         }
 523
 524         fd = socket(AF_INET, SOCK_DGRAM, 0);
 525         if (fd < 0) {
 526                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
 527                     pcap_strerror(errno));
 528                 return (-1);
 529         }
 530         memset(&ifr, 0, sizeof(ifr));
 531 #ifdef linux
 532         /* XXX Work around Linux kernel bug */
 533         ifr.ifr_addr.sa_family = AF_INET;
 534 #endif
 535         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 536         if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
 537                 if (errno == EADDRNOTAVAIL) {
 538                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 539                             "%s: no IPv4 address assigned", device);
 540                 } else {
 541                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 542                             "SIOCGIFADDR: %s: %s",
 543                             device, pcap_strerror(errno));
 544                 }
 545                 (void)close(fd);
 546                 return (-1);
 547         }
 548         sin = (struct sockaddr_in *)&ifr.ifr_addr;
 549         *netp = sin->sin_addr.s_addr;
 550         if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
 551                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 552                     "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
 553                 (void)close(fd);
 554                 return (-1);
 555         }
 556         (void)close(fd);
 557         *maskp = sin->sin_addr.s_addr;
 558         if (*maskp == 0) {
 559                 if (IN_CLASSA(*netp))
 560                         *maskp = IN_CLASSA_NET;
 561                 else if (IN_CLASSB(*netp))
 562                         *maskp = IN_CLASSB_NET;
 563                 else if (IN_CLASSC(*netp))
 564                         *maskp = IN_CLASSC_NET;
 565                 else {
 566                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 567                             "inet class for 0x%x unknown", *netp);
 568                         return (-1);
 569                 }
 570         }
 571         *netp &= *maskp;
 572         return (0);
 573 }
 574
 575 #elif defined(WIN32)
 576
 577 /*
 578  * Return the name of a network interface attached to the system, or NULL
 579  * if none can be found.  The interface must be configured up; the
 580  * lowest unit number is preferred; loopback is ignored.
 581  */
 582 char *
 583 pcap_lookupdev(errbuf)
 584         register char *errbuf;
 585 {
 586         DWORD dwVersion;
 587         DWORD dwWindowsMajorVersion;
 588         dwVersion = GetVersion();       /* get the OS version */
 589         dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
 590
 591         if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
 592                 /*
 593                  * Windows 95, 98, ME.
 594                  */
 595                 ULONG NameLength = 8192;
 596                 static char AdaptersName[8192];
 597
 598                 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
 599                         return (AdaptersName);
 600                 else
 601                         return NULL;
 602         } else {
 603                 /*
 604                  * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
 605                  */
 606                 ULONG NameLength = 8192;
 607                 static WCHAR AdaptersName[8192];
 608                 char *tAstr;
 609                 WCHAR *tUstr;
 610                 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
 611                 int NAdapts = 0;
 612
 613                 if(TAdaptersName == NULL)
 614                 {
 615                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
 616                         return NULL;
 617                 }
 618
 619                 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
 620                 {
 621                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 622                                 "PacketGetAdapterNames: %s",
 623                                 pcap_win32strerror());
 624                         free(TAdaptersName);
 625                         return NULL;
 626                 }
 627
 628
 629                 tAstr = (char*)TAdaptersName;
 630                 tUstr = (WCHAR*)AdaptersName;
 631
 632                 /*
 633                  * Convert and copy the device names
 634                  */
 635                 while(sscanf(tAstr, "%S", tUstr) > 0)
 636                 {
 637                         tAstr += strlen(tAstr) + 1;
 638                         tUstr += wcslen(tUstr) + 1;
 639                         NAdapts ++;
 640                 }
 641
 642                 tAstr++;
 643                 *tUstr = 0;
 644                 tUstr++;
 645
 646                 /*
 647                  * Copy the descriptions
 648                  */
 649                 while(NAdapts--)
 650                 {
 651                         strcpy((char*)tUstr, tAstr);
 652                         (char*)tUstr += strlen(tAstr) + 1;;
 653                         tAstr += strlen(tAstr) + 1;
 654                 }
 655
 656                 free(TAdaptersName);
 657                 return (char *)(AdaptersName);
 658         }
 659 }
 660
 661
 662 int
 663 pcap_lookupnet(device, netp, maskp, errbuf)
 664         const register char *device;
 665         register bpf_u_int32 *netp, *maskp;
 666         register char *errbuf;
 667 {
 668         /*
 669          * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
 670          * in order to skip non IPv4 (i.e. IPv6 addresses)
 671          */
 672         npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
 673         LONG if_addr_size = 1;
 674         struct sockaddr_in *t_addr;
 675         unsigned int i;
 676
 677         if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
 678                 *netp = *maskp = 0;
 679                 return (0);
 680         }
 681
 682         for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
 683         {
 684                 if(if_addrs[i].IPAddress.ss_family == AF_INET)
 685                 {
 686                         t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
 687                         *netp = t_addr->sin_addr.S_un.S_addr;
 688                         t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
 689                         *maskp = t_addr->sin_addr.S_un.S_addr;
 690
 691                         *netp &= *maskp;
 692                         return (0);
 693                 }
 694
 695         }
 696
 697         *netp = *maskp = 0;
 698         return (0);
 699 }
 700
 701 #endif /* !WIN32 && !MSDOS */