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 1.79 2008-04-20 18:19:02 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                  * On OS X, we don't do this check if the device
 161                  * name begins with "wlt"; at least some versions
 162                  * of OS X offer monitor mode capturing by having
 163                  * a separate "monitor mode" device for each wireless
 164                  * adapter, rather than by implementing the ioctls
 165                  * that {Free,Net,Open,DragonFly}BSD provide.
 166                  * Opening that device puts the adapter into monitor
 167                  * mode, which, at least for some adapters, causes
 168                  * them to deassociate from the network with which
 169                  * they're associated.
 170                  *
 171                  * Instead, we try to open the corresponding "en"
 172                  * device (so that we don't end up with, for users
 173                  * without sufficient privilege to open capture
 174                  * devices, a list of adapters that only includes
 175                  * the wlt devices).
 176                  */
 177 #ifdef __APPLE__
 178                 if (strncmp(name, "wlt", 3) == 0) {
 179                         char *en_name;
 180                         size_t en_name_len;
 181
 182                         /*
 183                          * Try to allocate a buffer for the "en"
 184                          * device's name.
 185                          */
 186                         en_name_len = strlen(name) - 1;
 187                         en_name = malloc(en_name_len + 1);
 188                         if (en_name == NULL) {
 189                                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 190                                     "malloc: %s", pcap_strerror(errno));
 191                                 return (-1);
 192                         }
 193                         strcpy(en_name, "en");
 194                         strcat(en_name, name + 3);
 195                         p = pcap_open_live(en_name, 68, 0, 0, errbuf);
 196                         free(en_name);
 197                 } else
 198 #endif /* __APPLE */
 199                 p = pcap_open_live(name, 68, 0, 0, errbuf);
 200                 if (p == NULL) {
 201                         /*
 202                          * No.  Don't bother including it.
 203                          * Don't treat this as an error, though.
 204                          */
 205                         *curdev_ret = NULL;
 206                         return (0);
 207                 }
 208                 pcap_close(p);
 209
 210                 /*
 211                  * Yes, we can open it.
 212                  * Allocate a new entry.
 213                  */
 214                 curdev = malloc(sizeof(pcap_if_t));
 215                 if (curdev == NULL) {
 216                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 217                             "malloc: %s", pcap_strerror(errno));
 218                         return (-1);
 219                 }
 220
 221                 /*
 222                  * Fill in the entry.
 223                  */
 224                 curdev->next = NULL;
 225                 curdev->name = strdup(name);
 226                 if (curdev->name == NULL) {
 227                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 228                             "malloc: %s", pcap_strerror(errno));
 229                         free(curdev);
 230                         return (-1);
 231                 }
 232                 if (description != NULL) {
 233                         /*
 234                          * We have a description for this interface.
 235                          */
 236                         curdev->description = strdup(description);
 237                         if (curdev->description == NULL) {
 238                                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 239                                     "malloc: %s", pcap_strerror(errno));
 240                                 free(curdev->name);
 241                                 free(curdev);
 242                                 return (-1);
 243                         }
 244                 } else {
 245                         /*
 246                          * We don't.
 247                          */
 248                         curdev->description = NULL;
 249                 }
 250                 curdev->addresses = NULL;       /* list starts out as empty */
 251                 curdev->flags = 0;
 252                 if (ISLOOPBACK(name, flags))
 253                         curdev->flags |= PCAP_IF_LOOPBACK;
 254
 255                 /*
 256                  * Add it to the list, in the appropriate location.
 257                  * First, get the instance number of this interface.
 258                  */
 259                 this_instance = get_instance(name);
 260
 261                 /*
 262                  * Now look for the last interface with an instance number
 263                  * less than or equal to the new interface's instance
 264                  * number - except that non-loopback interfaces are
 265                  * arbitrarily treated as having interface numbers less
 266                  * than those of loopback interfaces, so the loopback
 267                  * interfaces are put at the end of the list.
 268                  *
 269                  * We start with "prevdev" being NULL, meaning we're before
 270                  * the first element in the list.
 271                  */
 272                 prevdev = NULL;
 273                 for (;;) {
 274                         /*
 275                          * Get the interface after this one.
 276                          */
 277                         if (prevdev == NULL) {
 278                                 /*
 279                                  * The next element is the first element.
 280                                  */
 281                                 nextdev = *alldevs;
 282                         } else
 283                                 nextdev = prevdev->next;
 284
 285                         /*
 286                          * Are we at the end of the list?
 287                          */
 288                         if (nextdev == NULL) {
 289                                 /*
 290                                  * Yes - we have to put the new entry
 291                                  * after "prevdev".
 292                                  */
 293                                 break;
 294                         }
 295
 296                         /*
 297                          * Is the new interface a non-loopback interface
 298                          * and the next interface a loopback interface?
 299                          */
 300                         if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
 301                             (nextdev->flags & PCAP_IF_LOOPBACK)) {
 302                                 /*
 303                                  * Yes, we should put the new entry
 304                                  * before "nextdev", i.e. after "prevdev".
 305                                  */
 306                                 break;
 307                         }
 308
 309                         /*
 310                          * Is the new interface's instance number less
 311                          * than the next interface's instance number,
 312                          * and is it the case that the new interface is a
 313                          * non-loopback interface or the next interface is
 314                          * a loopback interface?
 315                          *
 316                          * (The goal of both loopback tests is to make
 317                          * sure that we never put a loopback interface
 318                          * before any non-loopback interface and that we
 319                          * always put a non-loopback interface before all
 320                          * loopback interfaces.)
 321                          */
 322                         if (this_instance < get_instance(nextdev->name) &&
 323                             (!(curdev->flags & PCAP_IF_LOOPBACK) ||
 324                                (nextdev->flags & PCAP_IF_LOOPBACK))) {
 325                                 /*
 326                                  * Yes - we should put the new entry
 327                                  * before "nextdev", i.e. after "prevdev".
 328                                  */
 329                                 break;
 330                         }
 331
 332                         prevdev = nextdev;
 333                 }
 334
 335                 /*
 336                  * Insert before "nextdev".
 337                  */
 338                 curdev->next = nextdev;
 339
 340                 /*
 341                  * Insert after "prevdev" - unless "prevdev" is null,
 342                  * in which case this is the first interface.
 343                  */
 344                 if (prevdev == NULL) {
 345                         /*
 346                          * This is the first interface.  Pass back a
 347                          * pointer to it, and put "curdev" before
 348                          * "nextdev".
 349                          */
 350                         *alldevs = curdev;
 351                 } else
 352                         prevdev->next = curdev;
 353         }
 354
 355         *curdev_ret = curdev;
 356         return (0);
 357 }
 358
 359 /*
 360  * XXX - on FreeBSDs that support it, should it get the sysctl named
 361  * "dev.{adapter family name}.{adapter unit}.%desc" to get a description
 362  * of the adapter?  Note that "dev.an.0.%desc" is "Aironet PC4500/PC4800"
 363  * with my Cisco 350 card, so the name isn't entirely descriptive.  The
 364  * "dev.an.0.%pnpinfo" has a better description, although one might argue
 365  * that the problem is really a driver bug - if it can find out that it's
 366  * a Cisco 340 or 350, rather than an old Aironet card, it should use
 367  * that in the description.
 368  *
 369  * Do NetBSD, DragonflyBSD, or OpenBSD support this as well?  OpenBSD
 370  * lets you get a description, but it's not generated by the OS, it's
 371  * set with another ioctl that ifconfig supports; we use that to get
 372  * the description in OpenBSD.
 373  *
 374  * In OS X, the System Configuration framework can apparently return
 375  * names in 10.4 and later; it also appears that freedesktop.org's HAL
 376  * offers an "info.product" string, but the HAL specification says
 377  * it "should not be used in any UI" and "subsystem/capability
 378  * specific properties" should be used instead.  Using that would
 379  * require that libpcap applications be linked with the frameworks/
 380  * libraries in question, which would be a bit of a pain unless we
 381  * offer, for example, a pkg-config:
 382  *
 383  *      http://pkg-config.freedesktop.org/wiki/
 384  *
 385  * script, so applications can just use that script to find out what
 386  * libraries you need to link with when linking with libpcap.
 387  * pkg-config is GPLed; I don't know whether that would prevent its
 388  * use with a BSD-licensed library such as libpcap.
 389  *
 390  * Do any other UN*Xes, or desktop environments support getting a
 391  * description?
 392  */
 393 int
 394 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
 395     struct sockaddr *addr, size_t addr_size,
 396     struct sockaddr *netmask, size_t netmask_size,
 397     struct sockaddr *broadaddr, size_t broadaddr_size,
 398     struct sockaddr *dstaddr, size_t dstaddr_size,
 399     char *errbuf)
 400 {
 401         pcap_if_t *curdev;
 402         char *description = NULL;
 403         pcap_addr_t *curaddr, *prevaddr, *nextaddr;
 404 #ifdef SIOCGIFDESCR
 405         struct ifreq ifrdesc;
 406         char ifdescr[IFDESCRSIZE];
 407         int s;
 408 #endif
 409
 410 #ifdef SIOCGIFDESCR
 411         /*
 412          * Get the description for the interface.
 413          */
 414         memset(&ifrdesc, 0, sizeof ifrdesc);
 415         strlcpy(ifrdesc.ifr_name, name, sizeof ifrdesc.ifr_name);
 416         ifrdesc.ifr_data = (caddr_t)&ifdescr;
 417         s = socket(AF_INET, SOCK_DGRAM, 0);
 418         if (s >= 0) {
 419                 if (ioctl(s, SIOCGIFDESCR, &ifrdesc) == 0 &&
 420                     strlen(ifrdesc.ifr_data) != 0)
 421                         description = ifrdesc.ifr_data;
 422                 close(s);
 423         }
 424 #endif
 425
 426         if (add_or_find_if(&curdev, alldevs, name, flags, description,
 427             errbuf) == -1) {
 428                 /*
 429                  * Error - give up.
 430                  */
 431                 return (-1);
 432         }
 433         if (curdev == NULL) {
 434                 /*
 435                  * Device wasn't added because it can't be opened.
 436                  * Not a fatal error.
 437                  */
 438                 return (0);
 439         }
 440
 441         /*
 442          * "curdev" is an entry for this interface; add an entry for this
 443          * address to its list of addresses.
 444          *
 445          * Allocate the new entry and fill it in.
 446          */
 447         curaddr = malloc(sizeof(pcap_addr_t));
 448         if (curaddr == NULL) {
 449                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 450                     "malloc: %s", pcap_strerror(errno));
 451                 return (-1);
 452         }
 453
 454         curaddr->next = NULL;
 455         if (addr != NULL) {
 456                 curaddr->addr = dup_sockaddr(addr, addr_size);
 457                 if (curaddr->addr == NULL) {
 458                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 459                             "malloc: %s", pcap_strerror(errno));
 460                         free(curaddr);
 461                         return (-1);
 462                 }
 463         } else
 464                 curaddr->addr = NULL;
 465
 466         if (netmask != NULL) {
 467                 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
 468                 if (curaddr->netmask == NULL) {
 469                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 470                             "malloc: %s", pcap_strerror(errno));
 471                         if (curaddr->addr != NULL)
 472                                 free(curaddr->addr);
 473                         free(curaddr);
 474                         return (-1);
 475                 }
 476         } else
 477                 curaddr->netmask = NULL;
 478
 479         if (broadaddr != NULL) {
 480                 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
 481                 if (curaddr->broadaddr == NULL) {
 482                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 483                             "malloc: %s", pcap_strerror(errno));
 484                         if (curaddr->netmask != NULL)
 485                                 free(curaddr->netmask);
 486                         if (curaddr->addr != NULL)
 487                                 free(curaddr->addr);
 488                         free(curaddr);
 489                         return (-1);
 490                 }
 491         } else
 492                 curaddr->broadaddr = NULL;
 493
 494         if (dstaddr != NULL) {
 495                 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
 496                 if (curaddr->dstaddr == NULL) {
 497                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 498                             "malloc: %s", pcap_strerror(errno));
 499                         if (curaddr->broadaddr != NULL)
 500                                 free(curaddr->broadaddr);
 501                         if (curaddr->netmask != NULL)
 502                                 free(curaddr->netmask);
 503                         if (curaddr->addr != NULL)
 504                                 free(curaddr->addr);
 505                         free(curaddr);
 506                         return (-1);
 507                 }
 508         } else
 509                 curaddr->dstaddr = NULL;
 510
 511         /*
 512          * Find the end of the list of addresses.
 513          */
 514         for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
 515                 nextaddr = prevaddr->next;
 516                 if (nextaddr == NULL) {
 517                         /*
 518                          * This is the end of the list.
 519                          */
 520                         break;
 521                 }
 522         }
 523
 524         if (prevaddr == NULL) {
 525                 /*
 526                  * The list was empty; this is the first member.
 527                  */
 528                 curdev->addresses = curaddr;
 529         } else {
 530                 /*
 531                  * "prevaddr" is the last member of the list; append
 532                  * this member to it.
 533                  */
 534                 prevaddr->next = curaddr;
 535         }
 536
 537         return (0);
 538 }
 539
 540 int
 541 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
 542     const char *description, char *errbuf)
 543 {
 544         pcap_if_t *curdev;
 545
 546         return (add_or_find_if(&curdev, devlist, name, flags, description,
 547             errbuf));
 548 }
 549
 550
 551 /*
 552  * Free a list of interfaces.
 553  */
 554 void
 555 pcap_freealldevs(pcap_if_t *alldevs)
 556 {
 557         pcap_if_t *curdev, *nextdev;
 558         pcap_addr_t *curaddr, *nextaddr;
 559
 560         for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
 561                 nextdev = curdev->next;
 562
 563                 /*
 564                  * Free all addresses.
 565                  */
 566                 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
 567                         nextaddr = curaddr->next;
 568                         if (curaddr->addr)
 569                                 free(curaddr->addr);
 570                         if (curaddr->netmask)
 571                                 free(curaddr->netmask);
 572                         if (curaddr->broadaddr)
 573                                 free(curaddr->broadaddr);
 574                         if (curaddr->dstaddr)
 575                                 free(curaddr->dstaddr);
 576                         free(curaddr);
 577                 }
 578
 579                 /*
 580                  * Free the name string.
 581                  */
 582                 free(curdev->name);
 583
 584                 /*
 585                  * Free the description string, if any.
 586                  */
 587                 if (curdev->description != NULL)
 588                         free(curdev->description);
 589
 590                 /*
 591                  * Free the interface.
 592                  */
 593                 free(curdev);
 594         }
 595 }
 596
 597 #if !defined(WIN32) && !defined(MSDOS)
 598
 599 /*
 600  * Return the name of a network interface attached to the system, or NULL
 601  * if none can be found.  The interface must be configured up; the
 602  * lowest unit number is preferred; loopback is ignored.
 603  */
 604 char *
 605 pcap_lookupdev(errbuf)
 606         register char *errbuf;
 607 {
 608         pcap_if_t *alldevs;
 609 /* for old BSD systems, including bsdi3 */
 610 #ifndef IF_NAMESIZE
 611 #define IF_NAMESIZE IFNAMSIZ
 612 #endif
 613         static char device[IF_NAMESIZE + 1];
 614         char *ret;
 615
 616         if (pcap_findalldevs(&alldevs, errbuf) == -1)
 617                 return (NULL);
 618
 619         if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
 620                 /*
 621                  * There are no devices on the list, or the first device
 622                  * on the list is a loopback device, which means there
 623                  * are no non-loopback devices on the list.  This means
 624                  * we can't return any device.
 625                  *
 626                  * XXX - why not return a loopback device?  If we can't
 627                  * capture on it, it won't be on the list, and if it's
 628                  * on the list, there aren't any non-loopback devices,
 629                  * so why not just supply it as the default device?
 630                  */
 631                 (void)strlcpy(errbuf, "no suitable device found",
 632                     PCAP_ERRBUF_SIZE);
 633                 ret = NULL;
 634         } else {
 635                 /*
 636                  * Return the name of the first device on the list.
 637                  */
 638                 (void)strlcpy(device, alldevs->name, sizeof(device));
 639                 ret = device;
 640         }
 641
 642         pcap_freealldevs(alldevs);
 643         return (ret);
 644 }
 645
 646 int
 647 pcap_lookupnet(device, netp, maskp, errbuf)
 648         register const char *device;
 649         register bpf_u_int32 *netp, *maskp;
 650         register char *errbuf;
 651 {
 652         register int fd;
 653         register struct sockaddr_in *sin4;
 654         struct ifreq ifr;
 655
 656         /*
 657          * The pseudo-device "any" listens on all interfaces and therefore
 658          * has the network address and -mask "0.0.0.0" therefore catching
 659          * all traffic. Using NULL for the interface is the same as "any".
 660          */
 661         if (!device || strcmp(device, "any") == 0
 662 #ifdef HAVE_DAG_API
 663             || strstr(device, "dag") != NULL
 664 #endif
 665 #ifdef HAVE_SEPTEL_API
 666             || strstr(device, "septel") != NULL
 667 #endif
 668 #ifdef PCAP_SUPPORT_BT
 669             || strstr(device, "bluetooth") != NULL
 670 #endif
 671 #ifdef PCAP_SUPPORT_USB
 672             || strstr(device, "usbmon") != NULL
 673 #endif
 674             ) {
 675                 *netp = *maskp = 0;
 676                 return 0;
 677         }
 678
 679         fd = socket(AF_INET, SOCK_DGRAM, 0);
 680         if (fd < 0) {
 681                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
 682                     pcap_strerror(errno));
 683                 return (-1);
 684         }
 685         memset(&ifr, 0, sizeof(ifr));
 686 #ifdef linux
 687         /* XXX Work around Linux kernel bug */
 688         ifr.ifr_addr.sa_family = AF_INET;
 689 #endif
 690         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 691         if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
 692                 if (errno == EADDRNOTAVAIL) {
 693                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 694                             "%s: no IPv4 address assigned", device);
 695                 } else {
 696                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 697                             "SIOCGIFADDR: %s: %s",
 698                             device, pcap_strerror(errno));
 699                 }
 700                 (void)close(fd);
 701                 return (-1);
 702         }
 703         sin4 = (struct sockaddr_in *)&ifr.ifr_addr;
 704         *netp = sin4->sin_addr.s_addr;
 705         memset(&ifr, 0, sizeof(ifr));
 706 #ifdef linux
 707         /* XXX Work around Linux kernel bug */
 708         ifr.ifr_addr.sa_family = AF_INET;
 709 #endif
 710         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 711         if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
 712                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 713                     "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
 714                 (void)close(fd);
 715                 return (-1);
 716         }
 717         (void)close(fd);
 718         *maskp = sin4->sin_addr.s_addr;
 719         if (*maskp == 0) {
 720                 if (IN_CLASSA(*netp))
 721                         *maskp = IN_CLASSA_NET;
 722                 else if (IN_CLASSB(*netp))
 723                         *maskp = IN_CLASSB_NET;
 724                 else if (IN_CLASSC(*netp))
 725                         *maskp = IN_CLASSC_NET;
 726                 else {
 727                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 728                             "inet class for 0x%x unknown", *netp);
 729                         return (-1);
 730                 }
 731         }
 732         *netp &= *maskp;
 733         return (0);
 734 }
 735
 736 #elif defined(WIN32)
 737
 738 /*
 739  * Return the name of a network interface attached to the system, or NULL
 740  * if none can be found.  The interface must be configured up; the
 741  * lowest unit number is preferred; loopback is ignored.
 742  */
 743 char *
 744 pcap_lookupdev(errbuf)
 745         register char *errbuf;
 746 {
 747         DWORD dwVersion;
 748         DWORD dwWindowsMajorVersion;
 749         dwVersion = GetVersion();       /* get the OS version */
 750         dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
 751
 752         if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
 753                 /*
 754                  * Windows 95, 98, ME.
 755                  */
 756                 ULONG NameLength = 8192;
 757                 static char AdaptersName[8192];
 758
 759                 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
 760                         return (AdaptersName);
 761                 else
 762                         return NULL;
 763         } else {
 764                 /*
 765                  * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
 766                  */
 767                 ULONG NameLength = 8192;
 768                 static WCHAR AdaptersName[8192];
 769                 char *tAstr;
 770                 WCHAR *tUstr;
 771                 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
 772                 int NAdapts = 0;
 773
 774                 if(TAdaptersName == NULL)
 775                 {
 776                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
 777                         return NULL;
 778                 }
 779
 780                 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
 781                 {
 782                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 783                                 "PacketGetAdapterNames: %s",
 784                                 pcap_win32strerror());
 785                         free(TAdaptersName);
 786                         return NULL;
 787                 }
 788
 789
 790                 tAstr = (char*)TAdaptersName;
 791                 tUstr = (WCHAR*)AdaptersName;
 792
 793                 /*
 794                  * Convert and copy the device names
 795                  */
 796                 while(sscanf(tAstr, "%S", tUstr) > 0)
 797                 {
 798                         tAstr += strlen(tAstr) + 1;
 799                         tUstr += wcslen(tUstr) + 1;
 800                         NAdapts ++;
 801                 }
 802
 803                 tAstr++;
 804                 *tUstr = 0;
 805                 tUstr++;
 806
 807                 /*
 808                  * Copy the descriptions
 809                  */
 810                 while(NAdapts--)
 811                 {
 812                         strcpy((char*)tUstr, tAstr);
 813                         (char*)tUstr += strlen(tAstr) + 1;;
 814                         tAstr += strlen(tAstr) + 1;
 815                 }
 816
 817                 free(TAdaptersName);
 818                 return (char *)(AdaptersName);
 819         }
 820 }
 821
 822
 823 int
 824 pcap_lookupnet(device, netp, maskp, errbuf)
 825         register const char *device;
 826         register bpf_u_int32 *netp, *maskp;
 827         register char *errbuf;
 828 {
 829         /*
 830          * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
 831          * in order to skip non IPv4 (i.e. IPv6 addresses)
 832          */
 833         npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
 834         LONG if_addr_size = 1;
 835         struct sockaddr_in *t_addr;
 836         unsigned int i;
 837
 838         if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
 839                 *netp = *maskp = 0;
 840                 return (0);
 841         }
 842
 843         for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
 844         {
 845                 if(if_addrs[i].IPAddress.ss_family == AF_INET)
 846                 {
 847                         t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
 848                         *netp = t_addr->sin_addr.S_un.S_addr;
 849                         t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
 850                         *maskp = t_addr->sin_addr.S_un.S_addr;
 851
 852                         *netp &= *maskp;
 853                         return (0);
 854                 }
 855
 856         }
 857
 858         *netp = *maskp = 0;
 859         return (0);
 860 }
 861
 862 #endif /* !WIN32 && !MSDOS */