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 1.71 2006-10-13 09:06:05 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_t *p;
 134         pcap_if_t *curdev, *prevdev, *nextdev;
 135         int this_instance;
 136
 137         /*
 138          * Is there already an entry in the list for this interface?
 139          */
 140         for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
 141                 if (strcmp(name, curdev->name) == 0)
 142                         break;  /* yes, we found it */
 143         }
 144
 145         if (curdev == NULL) {
 146                 /*
 147                  * No, we didn't find it.
 148                  *
 149                  * Can we open this interface for live capture?
 150                  *
 151                  * We do this check so that interfaces that are
 152                  * supplied by the interface enumeration mechanism
 153                  * we're using but that don't support packet capture
 154                  * aren't included in the list.  Loopback interfaces
 155                  * on Solaris are an example of this; we don't just
 156                  * omit loopback interfaces on all platforms because
 157                  * you *can* capture on loopback interfaces on some
 158                  * OSes.
 159                  */
 160                 p = pcap_open_live(name, 68, 0, 0, errbuf);
 161                 if (p == NULL) {
 162                         /*
 163                          * No.  Don't bother including it.
 164                          * Don't treat this as an error, though.
 165                          */
 166                         *curdev_ret = NULL;
 167                         return (0);
 168                 }
 169                 pcap_close(p);
 170
 171                 /*
 172                  * Yes, we can open it.
 173                  * Allocate a new entry.
 174                  */
 175                 curdev = malloc(sizeof(pcap_if_t));
 176                 if (curdev == NULL) {
 177                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 178                             "malloc: %s", pcap_strerror(errno));
 179                         return (-1);
 180                 }
 181
 182                 /*
 183                  * Fill in the entry.
 184                  */
 185                 curdev->next = NULL;
 186                 curdev->name = strdup(name);
 187                 if (curdev->name == NULL) {
 188                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 189                             "malloc: %s", pcap_strerror(errno));
 190                         free(curdev);
 191                         return (-1);
 192                 }
 193                 if (description != NULL) {
 194                         /*
 195                          * We have a description for this interface.
 196                          */
 197                         curdev->description = strdup(description);
 198                         if (curdev->description == NULL) {
 199                                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 200                                     "malloc: %s", pcap_strerror(errno));
 201                                 free(curdev->name);
 202                                 free(curdev);
 203                                 return (-1);
 204                         }
 205                 } else {
 206                         /*
 207                          * We don't.
 208                          */
 209                         curdev->description = NULL;
 210                 }
 211                 curdev->addresses = NULL;       /* list starts out as empty */
 212                 curdev->flags = 0;
 213                 if (ISLOOPBACK(name, flags))
 214                         curdev->flags |= PCAP_IF_LOOPBACK;
 215
 216                 /*
 217                  * Add it to the list, in the appropriate location.
 218                  * First, get the instance number of this interface.
 219                  */
 220                 this_instance = get_instance(name);
 221
 222                 /*
 223                  * Now look for the last interface with an instance number
 224                  * less than or equal to the new interface's instance
 225                  * number - except that non-loopback interfaces are
 226                  * arbitrarily treated as having interface numbers less
 227                  * than those of loopback interfaces, so the loopback
 228                  * interfaces are put at the end of the list.
 229                  *
 230                  * We start with "prevdev" being NULL, meaning we're before
 231                  * the first element in the list.
 232                  */
 233                 prevdev = NULL;
 234                 for (;;) {
 235                         /*
 236                          * Get the interface after this one.
 237                          */
 238                         if (prevdev == NULL) {
 239                                 /*
 240                                  * The next element is the first element.
 241                                  */
 242                                 nextdev = *alldevs;
 243                         } else
 244                                 nextdev = prevdev->next;
 245
 246                         /*
 247                          * Are we at the end of the list?
 248                          */
 249                         if (nextdev == NULL) {
 250                                 /*
 251                                  * Yes - we have to put the new entry
 252                                  * after "prevdev".
 253                                  */
 254                                 break;
 255                         }
 256
 257                         /*
 258                          * Is the new interface a non-loopback interface
 259                          * and the next interface a loopback interface?
 260                          */
 261                         if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
 262                             (nextdev->flags & PCAP_IF_LOOPBACK)) {
 263                                 /*
 264                                  * Yes, we should put the new entry
 265                                  * before "nextdev", i.e. after "prevdev".
 266                                  */
 267                                 break;
 268                         }
 269
 270                         /*
 271                          * Is the new interface's instance number less
 272                          * than the next interface's instance number,
 273                          * and is it the case that the new interface is a
 274                          * non-loopback interface or the next interface is
 275                          * a loopback interface?
 276                          *
 277                          * (The goal of both loopback tests is to make
 278                          * sure that we never put a loopback interface
 279                          * before any non-loopback interface and that we
 280                          * always put a non-loopback interface before all
 281                          * loopback interfaces.)
 282                          */
 283                         if (this_instance < get_instance(nextdev->name) &&
 284                             (!(curdev->flags & PCAP_IF_LOOPBACK) ||
 285                                (nextdev->flags & PCAP_IF_LOOPBACK))) {
 286                                 /*
 287                                  * Yes - we should put the new entry
 288                                  * before "nextdev", i.e. after "prevdev".
 289                                  */
 290                                 break;
 291                         }
 292
 293                         prevdev = nextdev;
 294                 }
 295
 296                 /*
 297                  * Insert before "nextdev".
 298                  */
 299                 curdev->next = nextdev;
 300
 301                 /*
 302                  * Insert after "prevdev" - unless "prevdev" is null,
 303                  * in which case this is the first interface.
 304                  */
 305                 if (prevdev == NULL) {
 306                         /*
 307                          * This is the first interface.  Pass back a
 308                          * pointer to it, and put "curdev" before
 309                          * "nextdev".
 310                          */
 311                         *alldevs = curdev;
 312                 } else
 313                         prevdev->next = curdev;
 314         }
 315
 316         *curdev_ret = curdev;
 317         return (0);
 318 }
 319
 320 /*
 321  * XXX - on FreeBSDs that support it, should it get the sysctl named
 322  * "dev.{adapter family name}.{adapter unit}.%desc" to get a description
 323  * of the adapter?  Note that "dev.an.0.%desc" is "Aironet PC4500/PC4800"
 324  * with my Cisco 350 card, so the name isn't entirely descriptive.  The
 325  * "dev.an.0.%pnpinfo" has a better description, although one might argue
 326  * that the problem is really a driver bug - if it can find out that it's
 327  * a Cisco 340 or 350, rather than an old Aironet card, it should use
 328  * that in the description.
 329  *
 330  * Do NetBSD, DragonflyBSD, or OpenBSD support this as well?
 331  * Do any other UN*Xes support getting a description?
 332  */
 333 int
 334 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
 335     struct sockaddr *addr, size_t addr_size,
 336     struct sockaddr *netmask, size_t netmask_size,
 337     struct sockaddr *broadaddr, size_t broadaddr_size,
 338     struct sockaddr *dstaddr, size_t dstaddr_size,
 339     char *errbuf)
 340 {
 341         pcap_if_t *curdev;
 342         pcap_addr_t *curaddr, *prevaddr, *nextaddr;
 343
 344         if (add_or_find_if(&curdev, alldevs, name, flags, NULL, errbuf) == -1) {
 345                 /*
 346                  * Error - give up.
 347                  */
 348                 return (-1);
 349         }
 350         if (curdev == NULL) {
 351                 /*
 352                  * Device wasn't added because it can't be opened.
 353                  * Not a fatal error.
 354                  */
 355                 return (0);
 356         }
 357
 358         /*
 359          * "curdev" is an entry for this interface; add an entry for this
 360          * address to its list of addresses.
 361          *
 362          * Allocate the new entry and fill it in.
 363          */
 364         curaddr = malloc(sizeof(pcap_addr_t));
 365         if (curaddr == NULL) {
 366                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 367                     "malloc: %s", pcap_strerror(errno));
 368                 return (-1);
 369         }
 370
 371         curaddr->next = NULL;
 372         if (addr != NULL) {
 373                 curaddr->addr = dup_sockaddr(addr, addr_size);
 374                 if (curaddr->addr == NULL) {
 375                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 376                             "malloc: %s", pcap_strerror(errno));
 377                         free(curaddr);
 378                         return (-1);
 379                 }
 380         } else
 381                 curaddr->addr = NULL;
 382
 383         if (netmask != NULL) {
 384                 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
 385                 if (curaddr->netmask == NULL) {
 386                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 387                             "malloc: %s", pcap_strerror(errno));
 388                         if (curaddr->addr != NULL)
 389                                 free(curaddr->addr);
 390                         free(curaddr);
 391                         return (-1);
 392                 }
 393         } else
 394                 curaddr->netmask = NULL;
 395
 396         if (broadaddr != NULL) {
 397                 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
 398                 if (curaddr->broadaddr == NULL) {
 399                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 400                             "malloc: %s", pcap_strerror(errno));
 401                         if (curaddr->netmask != NULL)
 402                                 free(curaddr->netmask);
 403                         if (curaddr->addr != NULL)
 404                                 free(curaddr->addr);
 405                         free(curaddr);
 406                         return (-1);
 407                 }
 408         } else
 409                 curaddr->broadaddr = NULL;
 410
 411         if (dstaddr != NULL) {
 412                 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
 413                 if (curaddr->dstaddr == NULL) {
 414                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 415                             "malloc: %s", pcap_strerror(errno));
 416                         if (curaddr->broadaddr != NULL)
 417                                 free(curaddr->broadaddr);
 418                         if (curaddr->netmask != NULL)
 419                                 free(curaddr->netmask);
 420                         if (curaddr->addr != NULL)
 421                                 free(curaddr->addr);
 422                         free(curaddr);
 423                         return (-1);
 424                 }
 425         } else
 426                 curaddr->dstaddr = NULL;
 427
 428         /*
 429          * Find the end of the list of addresses.
 430          */
 431         for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
 432                 nextaddr = prevaddr->next;
 433                 if (nextaddr == NULL) {
 434                         /*
 435                          * This is the end of the list.
 436                          */
 437                         break;
 438                 }
 439         }
 440
 441         if (prevaddr == NULL) {
 442                 /*
 443                  * The list was empty; this is the first member.
 444                  */
 445                 curdev->addresses = curaddr;
 446         } else {
 447                 /*
 448                  * "prevaddr" is the last member of the list; append
 449                  * this member to it.
 450                  */
 451                 prevaddr->next = curaddr;
 452         }
 453
 454         return (0);
 455 }
 456
 457 int
 458 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
 459     const char *description, char *errbuf)
 460 {
 461         pcap_if_t *curdev;
 462
 463         return (add_or_find_if(&curdev, devlist, name, flags, description,
 464             errbuf));
 465 }
 466
 467
 468 /*
 469  * Free a list of interfaces.
 470  */
 471 void
 472 pcap_freealldevs(pcap_if_t *alldevs)
 473 {
 474         pcap_if_t *curdev, *nextdev;
 475         pcap_addr_t *curaddr, *nextaddr;
 476
 477         for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
 478                 nextdev = curdev->next;
 479
 480                 /*
 481                  * Free all addresses.
 482                  */
 483                 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
 484                         nextaddr = curaddr->next;
 485                         if (curaddr->addr)
 486                                 free(curaddr->addr);
 487                         if (curaddr->netmask)
 488                                 free(curaddr->netmask);
 489                         if (curaddr->broadaddr)
 490                                 free(curaddr->broadaddr);
 491                         if (curaddr->dstaddr)
 492                                 free(curaddr->dstaddr);
 493                         free(curaddr);
 494                 }
 495
 496                 /*
 497                  * Free the name string.
 498                  */
 499                 free(curdev->name);
 500
 501                 /*
 502                  * Free the description string, if any.
 503                  */
 504                 if (curdev->description != NULL)
 505                         free(curdev->description);
 506
 507                 /*
 508                  * Free the interface.
 509                  */
 510                 free(curdev);
 511         }
 512 }
 513
 514 #if !defined(WIN32) && !defined(MSDOS)
 515
 516 /*
 517  * Return the name of a network interface attached to the system, or NULL
 518  * if none can be found.  The interface must be configured up; the
 519  * lowest unit number is preferred; loopback is ignored.
 520  */
 521 char *
 522 pcap_lookupdev(errbuf)
 523         register char *errbuf;
 524 {
 525         pcap_if_t *alldevs;
 526 /* for old BSD systems, including bsdi3 */
 527 #ifndef IF_NAMESIZE
 528 #define IF_NAMESIZE IFNAMSIZ
 529 #endif
 530         static char device[IF_NAMESIZE + 1];
 531         char *ret;
 532
 533         if (pcap_findalldevs(&alldevs, errbuf) == -1)
 534                 return (NULL);
 535
 536         if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
 537                 /*
 538                  * There are no devices on the list, or the first device
 539                  * on the list is a loopback device, which means there
 540                  * are no non-loopback devices on the list.  This means
 541                  * we can't return any device.
 542                  *
 543                  * XXX - why not return a loopback device?  If we can't
 544                  * capture on it, it won't be on the list, and if it's
 545                  * on the list, there aren't any non-loopback devices,
 546                  * so why not just supply it as the default device?
 547                  */
 548                 (void)strlcpy(errbuf, "no suitable device found",
 549                     PCAP_ERRBUF_SIZE);
 550                 ret = NULL;
 551         } else {
 552                 /*
 553                  * Return the name of the first device on the list.
 554                  */
 555                 (void)strlcpy(device, alldevs->name, sizeof(device));
 556                 ret = device;
 557         }
 558
 559         pcap_freealldevs(alldevs);
 560         return (ret);
 561 }
 562
 563 int
 564 pcap_lookupnet(device, netp, maskp, errbuf)
 565         register const char *device;
 566         register bpf_u_int32 *netp, *maskp;
 567         register char *errbuf;
 568 {
 569         register int fd;
 570         register struct sockaddr_in *sin;
 571         struct ifreq ifr;
 572
 573         /*
 574          * The pseudo-device "any" listens on all interfaces and therefore
 575          * has the network address and -mask "0.0.0.0" therefore catching
 576          * all traffic. Using NULL for the interface is the same as "any".
 577          */
 578         if (!device || strcmp(device, "any") == 0
 579 #ifdef HAVE_DAG_API
 580             || strstr(device, "dag") != NULL
 581 #endif
 582 #ifdef HAVE_SEPTEL_API
 583             || strstr(device, "septel") != NULL
 584 #endif
 585 #ifdef PCAP_SUPPORT_USB
 586             || strstr(device, "usb") != NULL
 587 #endif
 588             ) {
 589                 *netp = *maskp = 0;
 590                 return 0;
 591         }
 592
 593         fd = socket(AF_INET, SOCK_DGRAM, 0);
 594         if (fd < 0) {
 595                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
 596                     pcap_strerror(errno));
 597                 return (-1);
 598         }
 599         memset(&ifr, 0, sizeof(ifr));
 600 #ifdef linux
 601         /* XXX Work around Linux kernel bug */
 602         ifr.ifr_addr.sa_family = AF_INET;
 603 #endif
 604         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 605         if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
 606                 if (errno == EADDRNOTAVAIL) {
 607                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 608                             "%s: no IPv4 address assigned", device);
 609                 } else {
 610                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 611                             "SIOCGIFADDR: %s: %s",
 612                             device, pcap_strerror(errno));
 613                 }
 614                 (void)close(fd);
 615                 return (-1);
 616         }
 617         sin = (struct sockaddr_in *)&ifr.ifr_addr;
 618         *netp = sin->sin_addr.s_addr;
 619         if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
 620                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 621                     "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
 622                 (void)close(fd);
 623                 return (-1);
 624         }
 625         (void)close(fd);
 626         *maskp = sin->sin_addr.s_addr;
 627         if (*maskp == 0) {
 628                 if (IN_CLASSA(*netp))
 629                         *maskp = IN_CLASSA_NET;
 630                 else if (IN_CLASSB(*netp))
 631                         *maskp = IN_CLASSB_NET;
 632                 else if (IN_CLASSC(*netp))
 633                         *maskp = IN_CLASSC_NET;
 634                 else {
 635                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 636                             "inet class for 0x%x unknown", *netp);
 637                         return (-1);
 638                 }
 639         }
 640         *netp &= *maskp;
 641         return (0);
 642 }
 643
 644 #elif defined(WIN32)
 645
 646 /*
 647  * Return the name of a network interface attached to the system, or NULL
 648  * if none can be found.  The interface must be configured up; the
 649  * lowest unit number is preferred; loopback is ignored.
 650  */
 651 char *
 652 pcap_lookupdev(errbuf)
 653         register char *errbuf;
 654 {
 655         DWORD dwVersion;
 656         DWORD dwWindowsMajorVersion;
 657         dwVersion = GetVersion();       /* get the OS version */
 658         dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
 659
 660         if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
 661                 /*
 662                  * Windows 95, 98, ME.
 663                  */
 664                 ULONG NameLength = 8192;
 665                 static char AdaptersName[8192];
 666
 667                 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
 668                         return (AdaptersName);
 669                 else
 670                         return NULL;
 671         } else {
 672                 /*
 673                  * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
 674                  */
 675                 ULONG NameLength = 8192;
 676                 static WCHAR AdaptersName[8192];
 677                 char *tAstr;
 678                 WCHAR *tUstr;
 679                 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
 680                 int NAdapts = 0;
 681
 682                 if(TAdaptersName == NULL)
 683                 {
 684                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
 685                         return NULL;
 686                 }
 687
 688                 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
 689                 {
 690                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 691                                 "PacketGetAdapterNames: %s",
 692                                 pcap_win32strerror());
 693                         free(TAdaptersName);
 694                         return NULL;
 695                 }
 696
 697
 698                 tAstr = (char*)TAdaptersName;
 699                 tUstr = (WCHAR*)AdaptersName;
 700
 701                 /*
 702                  * Convert and copy the device names
 703                  */
 704                 while(sscanf(tAstr, "%S", tUstr) > 0)
 705                 {
 706                         tAstr += strlen(tAstr) + 1;
 707                         tUstr += wcslen(tUstr) + 1;
 708                         NAdapts ++;
 709                 }
 710
 711                 tAstr++;
 712                 *tUstr = 0;
 713                 tUstr++;
 714
 715                 /*
 716                  * Copy the descriptions
 717                  */
 718                 while(NAdapts--)
 719                 {
 720                         strcpy((char*)tUstr, tAstr);
 721                         (char*)tUstr += strlen(tAstr) + 1;;
 722                         tAstr += strlen(tAstr) + 1;
 723                 }
 724
 725                 free(TAdaptersName);
 726                 return (char *)(AdaptersName);
 727         }
 728 }
 729
 730
 731 int
 732 pcap_lookupnet(device, netp, maskp, errbuf)
 733         register const char *device;
 734         register bpf_u_int32 *netp, *maskp;
 735         register char *errbuf;
 736 {
 737         /*
 738          * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
 739          * in order to skip non IPv4 (i.e. IPv6 addresses)
 740          */
 741         npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
 742         LONG if_addr_size = 1;
 743         struct sockaddr_in *t_addr;
 744         unsigned int i;
 745
 746         if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
 747                 *netp = *maskp = 0;
 748                 return (0);
 749         }
 750
 751         for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
 752         {
 753                 if(if_addrs[i].IPAddress.ss_family == AF_INET)
 754                 {
 755                         t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
 756                         *netp = t_addr->sin_addr.S_un.S_addr;
 757                         t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
 758                         *maskp = t_addr->sin_addr.S_un.S_addr;
 759
 760                         *netp &= *maskp;
 761                         return (0);
 762                 }
 763
 764         }
 765
 766         *netp = *maskp = 0;
 767         return (0);
 768 }
 769
 770 #endif /* !WIN32 && !MSDOS */