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 1.74 2006-12-30 09:54:57 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?
 370  * Do any other UN*Xes support getting a description?
 371  */
 372 int
 373 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
 374     struct sockaddr *addr, size_t addr_size,
 375     struct sockaddr *netmask, size_t netmask_size,
 376     struct sockaddr *broadaddr, size_t broadaddr_size,
 377     struct sockaddr *dstaddr, size_t dstaddr_size,
 378     char *errbuf)
 379 {
 380         pcap_if_t *curdev;
 381         pcap_addr_t *curaddr, *prevaddr, *nextaddr;
 382
 383         if (add_or_find_if(&curdev, alldevs, name, flags, NULL, errbuf) == -1) {
 384                 /*
 385                  * Error - give up.
 386                  */
 387                 return (-1);
 388         }
 389         if (curdev == NULL) {
 390                 /*
 391                  * Device wasn't added because it can't be opened.
 392                  * Not a fatal error.
 393                  */
 394                 return (0);
 395         }
 396
 397         /*
 398          * "curdev" is an entry for this interface; add an entry for this
 399          * address to its list of addresses.
 400          *
 401          * Allocate the new entry and fill it in.
 402          */
 403         curaddr = malloc(sizeof(pcap_addr_t));
 404         if (curaddr == NULL) {
 405                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 406                     "malloc: %s", pcap_strerror(errno));
 407                 return (-1);
 408         }
 409
 410         curaddr->next = NULL;
 411         if (addr != NULL) {
 412                 curaddr->addr = dup_sockaddr(addr, addr_size);
 413                 if (curaddr->addr == NULL) {
 414                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 415                             "malloc: %s", pcap_strerror(errno));
 416                         free(curaddr);
 417                         return (-1);
 418                 }
 419         } else
 420                 curaddr->addr = NULL;
 421
 422         if (netmask != NULL) {
 423                 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
 424                 if (curaddr->netmask == NULL) {
 425                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 426                             "malloc: %s", pcap_strerror(errno));
 427                         if (curaddr->addr != NULL)
 428                                 free(curaddr->addr);
 429                         free(curaddr);
 430                         return (-1);
 431                 }
 432         } else
 433                 curaddr->netmask = NULL;
 434
 435         if (broadaddr != NULL) {
 436                 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
 437                 if (curaddr->broadaddr == NULL) {
 438                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 439                             "malloc: %s", pcap_strerror(errno));
 440                         if (curaddr->netmask != NULL)
 441                                 free(curaddr->netmask);
 442                         if (curaddr->addr != NULL)
 443                                 free(curaddr->addr);
 444                         free(curaddr);
 445                         return (-1);
 446                 }
 447         } else
 448                 curaddr->broadaddr = NULL;
 449
 450         if (dstaddr != NULL) {
 451                 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
 452                 if (curaddr->dstaddr == NULL) {
 453                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 454                             "malloc: %s", pcap_strerror(errno));
 455                         if (curaddr->broadaddr != NULL)
 456                                 free(curaddr->broadaddr);
 457                         if (curaddr->netmask != NULL)
 458                                 free(curaddr->netmask);
 459                         if (curaddr->addr != NULL)
 460                                 free(curaddr->addr);
 461                         free(curaddr);
 462                         return (-1);
 463                 }
 464         } else
 465                 curaddr->dstaddr = NULL;
 466
 467         /*
 468          * Find the end of the list of addresses.
 469          */
 470         for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
 471                 nextaddr = prevaddr->next;
 472                 if (nextaddr == NULL) {
 473                         /*
 474                          * This is the end of the list.
 475                          */
 476                         break;
 477                 }
 478         }
 479
 480         if (prevaddr == NULL) {
 481                 /*
 482                  * The list was empty; this is the first member.
 483                  */
 484                 curdev->addresses = curaddr;
 485         } else {
 486                 /*
 487                  * "prevaddr" is the last member of the list; append
 488                  * this member to it.
 489                  */
 490                 prevaddr->next = curaddr;
 491         }
 492
 493         return (0);
 494 }
 495
 496 int
 497 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
 498     const char *description, char *errbuf)
 499 {
 500         pcap_if_t *curdev;
 501
 502         return (add_or_find_if(&curdev, devlist, name, flags, description,
 503             errbuf));
 504 }
 505
 506
 507 /*
 508  * Free a list of interfaces.
 509  */
 510 void
 511 pcap_freealldevs(pcap_if_t *alldevs)
 512 {
 513         pcap_if_t *curdev, *nextdev;
 514         pcap_addr_t *curaddr, *nextaddr;
 515
 516         for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
 517                 nextdev = curdev->next;
 518
 519                 /*
 520                  * Free all addresses.
 521                  */
 522                 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
 523                         nextaddr = curaddr->next;
 524                         if (curaddr->addr)
 525                                 free(curaddr->addr);
 526                         if (curaddr->netmask)
 527                                 free(curaddr->netmask);
 528                         if (curaddr->broadaddr)
 529                                 free(curaddr->broadaddr);
 530                         if (curaddr->dstaddr)
 531                                 free(curaddr->dstaddr);
 532                         free(curaddr);
 533                 }
 534
 535                 /*
 536                  * Free the name string.
 537                  */
 538                 free(curdev->name);
 539
 540                 /*
 541                  * Free the description string, if any.
 542                  */
 543                 if (curdev->description != NULL)
 544                         free(curdev->description);
 545
 546                 /*
 547                  * Free the interface.
 548                  */
 549                 free(curdev);
 550         }
 551 }
 552
 553 #if !defined(WIN32) && !defined(MSDOS)
 554
 555 /*
 556  * Return the name of a network interface attached to the system, or NULL
 557  * if none can be found.  The interface must be configured up; the
 558  * lowest unit number is preferred; loopback is ignored.
 559  */
 560 char *
 561 pcap_lookupdev(errbuf)
 562         register char *errbuf;
 563 {
 564         pcap_if_t *alldevs;
 565 /* for old BSD systems, including bsdi3 */
 566 #ifndef IF_NAMESIZE
 567 #define IF_NAMESIZE IFNAMSIZ
 568 #endif
 569         static char device[IF_NAMESIZE + 1];
 570         char *ret;
 571
 572         if (pcap_findalldevs(&alldevs, errbuf) == -1)
 573                 return (NULL);
 574
 575         if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
 576                 /*
 577                  * There are no devices on the list, or the first device
 578                  * on the list is a loopback device, which means there
 579                  * are no non-loopback devices on the list.  This means
 580                  * we can't return any device.
 581                  *
 582                  * XXX - why not return a loopback device?  If we can't
 583                  * capture on it, it won't be on the list, and if it's
 584                  * on the list, there aren't any non-loopback devices,
 585                  * so why not just supply it as the default device?
 586                  */
 587                 (void)strlcpy(errbuf, "no suitable device found",
 588                     PCAP_ERRBUF_SIZE);
 589                 ret = NULL;
 590         } else {
 591                 /*
 592                  * Return the name of the first device on the list.
 593                  */
 594                 (void)strlcpy(device, alldevs->name, sizeof(device));
 595                 ret = device;
 596         }
 597
 598         pcap_freealldevs(alldevs);
 599         return (ret);
 600 }
 601
 602 int
 603 pcap_lookupnet(device, netp, maskp, errbuf)
 604         register const char *device;
 605         register bpf_u_int32 *netp, *maskp;
 606         register char *errbuf;
 607 {
 608         register int fd;
 609         register struct sockaddr_in *sin;
 610         struct ifreq ifr;
 611
 612         /*
 613          * The pseudo-device "any" listens on all interfaces and therefore
 614          * has the network address and -mask "0.0.0.0" therefore catching
 615          * all traffic. Using NULL for the interface is the same as "any".
 616          */
 617         if (!device || strcmp(device, "any") == 0
 618 #ifdef HAVE_DAG_API
 619             || strstr(device, "dag") != NULL
 620 #endif
 621 #ifdef HAVE_SEPTEL_API
 622             || strstr(device, "septel") != NULL
 623 #endif
 624 #ifdef PCAP_SUPPORT_BT
 625             || strstr(device, "bluetooth") != NULL
 626 #endif
 627 #ifdef PCAP_SUPPORT_USB
 628             || strstr(device, "usb") != NULL
 629 #endif
 630             ) {
 631                 *netp = *maskp = 0;
 632                 return 0;
 633         }
 634
 635         fd = socket(AF_INET, SOCK_DGRAM, 0);
 636         if (fd < 0) {
 637                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
 638                     pcap_strerror(errno));
 639                 return (-1);
 640         }
 641         memset(&ifr, 0, sizeof(ifr));
 642 #ifdef linux
 643         /* XXX Work around Linux kernel bug */
 644         ifr.ifr_addr.sa_family = AF_INET;
 645 #endif
 646         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 647         if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
 648                 if (errno == EADDRNOTAVAIL) {
 649                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 650                             "%s: no IPv4 address assigned", device);
 651                 } else {
 652                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 653                             "SIOCGIFADDR: %s: %s",
 654                             device, pcap_strerror(errno));
 655                 }
 656                 (void)close(fd);
 657                 return (-1);
 658         }
 659         sin = (struct sockaddr_in *)&ifr.ifr_addr;
 660         *netp = sin->sin_addr.s_addr;
 661         if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
 662                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 663                     "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
 664                 (void)close(fd);
 665                 return (-1);
 666         }
 667         (void)close(fd);
 668         *maskp = sin->sin_addr.s_addr;
 669         if (*maskp == 0) {
 670                 if (IN_CLASSA(*netp))
 671                         *maskp = IN_CLASSA_NET;
 672                 else if (IN_CLASSB(*netp))
 673                         *maskp = IN_CLASSB_NET;
 674                 else if (IN_CLASSC(*netp))
 675                         *maskp = IN_CLASSC_NET;
 676                 else {
 677                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 678                             "inet class for 0x%x unknown", *netp);
 679                         return (-1);
 680                 }
 681         }
 682         *netp &= *maskp;
 683         return (0);
 684 }
 685
 686 #elif defined(WIN32)
 687
 688 /*
 689  * Return the name of a network interface attached to the system, or NULL
 690  * if none can be found.  The interface must be configured up; the
 691  * lowest unit number is preferred; loopback is ignored.
 692  */
 693 char *
 694 pcap_lookupdev(errbuf)
 695         register char *errbuf;
 696 {
 697         DWORD dwVersion;
 698         DWORD dwWindowsMajorVersion;
 699         dwVersion = GetVersion();       /* get the OS version */
 700         dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
 701
 702         if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
 703                 /*
 704                  * Windows 95, 98, ME.
 705                  */
 706                 ULONG NameLength = 8192;
 707                 static char AdaptersName[8192];
 708
 709                 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
 710                         return (AdaptersName);
 711                 else
 712                         return NULL;
 713         } else {
 714                 /*
 715                  * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
 716                  */
 717                 ULONG NameLength = 8192;
 718                 static WCHAR AdaptersName[8192];
 719                 char *tAstr;
 720                 WCHAR *tUstr;
 721                 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
 722                 int NAdapts = 0;
 723
 724                 if(TAdaptersName == NULL)
 725                 {
 726                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
 727                         return NULL;
 728                 }
 729
 730                 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
 731                 {
 732                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 733                                 "PacketGetAdapterNames: %s",
 734                                 pcap_win32strerror());
 735                         free(TAdaptersName);
 736                         return NULL;
 737                 }
 738
 739
 740                 tAstr = (char*)TAdaptersName;
 741                 tUstr = (WCHAR*)AdaptersName;
 742
 743                 /*
 744                  * Convert and copy the device names
 745                  */
 746                 while(sscanf(tAstr, "%S", tUstr) > 0)
 747                 {
 748                         tAstr += strlen(tAstr) + 1;
 749                         tUstr += wcslen(tUstr) + 1;
 750                         NAdapts ++;
 751                 }
 752
 753                 tAstr++;
 754                 *tUstr = 0;
 755                 tUstr++;
 756
 757                 /*
 758                  * Copy the descriptions
 759                  */
 760                 while(NAdapts--)
 761                 {
 762                         strcpy((char*)tUstr, tAstr);
 763                         (char*)tUstr += strlen(tAstr) + 1;;
 764                         tAstr += strlen(tAstr) + 1;
 765                 }
 766
 767                 free(TAdaptersName);
 768                 return (char *)(AdaptersName);
 769         }
 770 }
 771
 772
 773 int
 774 pcap_lookupnet(device, netp, maskp, errbuf)
 775         register const char *device;
 776         register bpf_u_int32 *netp, *maskp;
 777         register char *errbuf;
 778 {
 779         /*
 780          * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
 781          * in order to skip non IPv4 (i.e. IPv6 addresses)
 782          */
 783         npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
 784         LONG if_addr_size = 1;
 785         struct sockaddr_in *t_addr;
 786         unsigned int i;
 787
 788         if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
 789                 *netp = *maskp = 0;
 790                 return (0);
 791         }
 792
 793         for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
 794         {
 795                 if(if_addrs[i].IPAddress.ss_family == AF_INET)
 796                 {
 797                         t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
 798                         *netp = t_addr->sin_addr.S_un.S_addr;
 799                         t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
 800                         *maskp = t_addr->sin_addr.S_un.S_addr;
 801
 802                         *netp &= *maskp;
 803                         return (0);
 804                 }
 805
 806         }
 807
 808         *netp = *maskp = 0;
 809         return (0);
 810 }
 811
 812 #endif /* !WIN32 && !MSDOS */