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?  FreeBSD
 370  * and OpenBSD let you get a description, but it's not generated by the OS,
 371  * it's set with another ioctl that ifconfig supports; we use that to get
 372  * a description in FreeBSD and OpenBSD, but if there is no such
 373  * description available, it still might be nice to get some description
 374  * string based on the device type or something such as that.
 375  *
 376  * In OS X, the System Configuration framework can apparently return
 377  * names in 10.4 and later.
 378  *
 379  * It also appears that freedesktop.org's HAL offers an "info.product"
 380  * string, but the HAL specification says it "should not be used in any
 381  * UI" and "subsystem/capability specific properties" should be used
 382  * instead and, in any case, I think HAL is being deprecated in
 383  * favor of other stuff such as DeviceKit.  DeviceKit doesn't appear
 384  * to have any obvious product information for devices, but maybe
 385  * I haven't looked hard enough.
 386  *
 387  * Using the System Configuration framework, or HAL, or DeviceKit, or
 388  * whatever, would require that libpcap applications be linked with
 389  * the frameworks/libraries in question.  That shouldn't be a problem
 390  * for programs linking with the shared version of libpcap (unless
 391  * you're running on AIX - which I think is the only UN*X that doesn't
 392  * support linking a shared library with other libraries on which it
 393  * depends, and having an executable linked only with the first shared
 394  * library automatically pick up the other libraries when started -
 395  * and using HAL or whatever).  Programs linked with the static
 396  * version of libpcap would have to use pcap-config with the --static
 397  * flag in order to get the right linker flags in order to pick up
 398  * the additional libraries/frameworks; those programs need that anyway
 399  * for libpcap 1.1 and beyond on Linux, as, by default, it requires
 400  * -lnl.
 401  *
 402  * Do any other UN*Xes, or desktop environments support getting a
 403  * description?
 404  */
 405 int
 406 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
 407     struct sockaddr *addr, size_t addr_size,
 408     struct sockaddr *netmask, size_t netmask_size,
 409     struct sockaddr *broadaddr, size_t broadaddr_size,
 410     struct sockaddr *dstaddr, size_t dstaddr_size,
 411     char *errbuf)
 412 {
 413         pcap_if_t *curdev;
 414         char *description = NULL;
 415         pcap_addr_t *curaddr, *prevaddr, *nextaddr;
 416 #ifdef SIOCGIFDESCR
 417         int s;
 418         struct ifreq ifrdesc;
 419 #ifndef IFDESCRSIZE
 420         size_t descrlen = 64;
 421 #else
 422         size_t descrlen = IFDESCRSIZE;
 423 #endif /* IFDESCRSIZE */
 424 #endif /* SIOCGIFDESCR */
 425
 426 #ifdef SIOCGIFDESCR
 427         /*
 428          * Get the description for the interface.
 429          */
 430         memset(&ifrdesc, 0, sizeof ifrdesc);
 431         strlcpy(ifrdesc.ifr_name, name, sizeof ifrdesc.ifr_name);
 432         s = socket(AF_INET, SOCK_DGRAM, 0);
 433         if (s >= 0) {
 434 #ifdef __FreeBSD__
 435                 /*
 436                  * On FreeBSD, if the buffer isn't big enough for the
 437                  * description, the ioctl succeeds, but the description
 438                  * isn't copied, ifr_buffer.length is set to the description
 439                  * length, and ifr_buffer.buffer is set to NULL.
 440                  */
 441                 for (;;) {
 442                         free(description);
 443                         if ((description = malloc(descrlen)) != NULL) {
 444                                 ifrdesc.ifr_buffer.buffer = description;
 445                                 ifrdesc.ifr_buffer.length = descrlen;
 446                                 if (ioctl(s, SIOCGIFDESCR, &ifrdesc) == 0) {
 447                                         if (ifrdesc.ifr_buffer.buffer ==
 448                                             description)
 449                                                 break;
 450                                         else
 451                                                 descrlen = ifrdesc.ifr_buffer.length;
 452                                 } else {
 453                                         /*
 454                                          * Failed to get interface description.
 455                                          */
 456                                         free(description);
 457                                         description = NULL;
 458                                         break;
 459                                 }
 460                         } else
 461                                 break;
 462                 }
 463 #else /* __FreeBSD__ */
 464                 /*
 465                  * The only other OS that currently supports
 466                  * SIOCGIFDESCR is OpenBSD, and it has no way
 467                  * to get the description length - it's clamped
 468                  * to a maximum of IFDESCRSIZE.
 469                  */
 470                 if ((description = malloc(descrlen)) != NULL) {
 471                         ifrdesc.ifr_data = (caddr_t)description;
 472                         if (ioctl(s, SIOCGIFDESCR, &ifrdesc) != 0) {
 473                                 /*
 474                                  * Failed to get interface description.
 475                                  */
 476                                 free(description);
 477                                 description = NULL;
 478                         }
 479                 }
 480 #endif /* __FreeBSD__ */
 481                 close(s);
 482                 if (description != NULL && strlen(description) == 0) {
 483                         free(description);
 484                         description = NULL;
 485                 }
 486         }
 487 #endif /* SIOCGIFDESCR */
 488
 489         if (add_or_find_if(&curdev, alldevs, name, flags, description,
 490             errbuf) == -1) {
 491                 free(description);
 492                 /*
 493                  * Error - give up.
 494                  */
 495                 return (-1);
 496         }
 497         free(description);
 498         if (curdev == NULL) {
 499                 /*
 500                  * Device wasn't added because it can't be opened.
 501                  * Not a fatal error.
 502                  */
 503                 return (0);
 504         }
 505
 506         /*
 507          * "curdev" is an entry for this interface; add an entry for this
 508          * address to its list of addresses.
 509          *
 510          * Allocate the new entry and fill it in.
 511          */
 512         curaddr = malloc(sizeof(pcap_addr_t));
 513         if (curaddr == NULL) {
 514                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 515                     "malloc: %s", pcap_strerror(errno));
 516                 return (-1);
 517         }
 518
 519         curaddr->next = NULL;
 520         if (addr != NULL) {
 521                 curaddr->addr = dup_sockaddr(addr, addr_size);
 522                 if (curaddr->addr == NULL) {
 523                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 524                             "malloc: %s", pcap_strerror(errno));
 525                         free(curaddr);
 526                         return (-1);
 527                 }
 528         } else
 529                 curaddr->addr = NULL;
 530
 531         if (netmask != NULL) {
 532                 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
 533                 if (curaddr->netmask == NULL) {
 534                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 535                             "malloc: %s", pcap_strerror(errno));
 536                         if (curaddr->addr != NULL)
 537                                 free(curaddr->addr);
 538                         free(curaddr);
 539                         return (-1);
 540                 }
 541         } else
 542                 curaddr->netmask = NULL;
 543
 544         if (broadaddr != NULL) {
 545                 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
 546                 if (curaddr->broadaddr == NULL) {
 547                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 548                             "malloc: %s", pcap_strerror(errno));
 549                         if (curaddr->netmask != NULL)
 550                                 free(curaddr->netmask);
 551                         if (curaddr->addr != NULL)
 552                                 free(curaddr->addr);
 553                         free(curaddr);
 554                         return (-1);
 555                 }
 556         } else
 557                 curaddr->broadaddr = NULL;
 558
 559         if (dstaddr != NULL) {
 560                 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
 561                 if (curaddr->dstaddr == NULL) {
 562                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 563                             "malloc: %s", pcap_strerror(errno));
 564                         if (curaddr->broadaddr != NULL)
 565                                 free(curaddr->broadaddr);
 566                         if (curaddr->netmask != NULL)
 567                                 free(curaddr->netmask);
 568                         if (curaddr->addr != NULL)
 569                                 free(curaddr->addr);
 570                         free(curaddr);
 571                         return (-1);
 572                 }
 573         } else
 574                 curaddr->dstaddr = NULL;
 575
 576         /*
 577          * Find the end of the list of addresses.
 578          */
 579         for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
 580                 nextaddr = prevaddr->next;
 581                 if (nextaddr == NULL) {
 582                         /*
 583                          * This is the end of the list.
 584                          */
 585                         break;
 586                 }
 587         }
 588
 589         if (prevaddr == NULL) {
 590                 /*
 591                  * The list was empty; this is the first member.
 592                  */
 593                 curdev->addresses = curaddr;
 594         } else {
 595                 /*
 596                  * "prevaddr" is the last member of the list; append
 597                  * this member to it.
 598                  */
 599                 prevaddr->next = curaddr;
 600         }
 601
 602         return (0);
 603 }
 604
 605 int
 606 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
 607     const char *description, char *errbuf)
 608 {
 609         pcap_if_t *curdev;
 610
 611         return (add_or_find_if(&curdev, devlist, name, flags, description,
 612             errbuf));
 613 }
 614
 615
 616 /*
 617  * Free a list of interfaces.
 618  */
 619 void
 620 pcap_freealldevs(pcap_if_t *alldevs)
 621 {
 622         pcap_if_t *curdev, *nextdev;
 623         pcap_addr_t *curaddr, *nextaddr;
 624
 625         for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
 626                 nextdev = curdev->next;
 627
 628                 /*
 629                  * Free all addresses.
 630                  */
 631                 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
 632                         nextaddr = curaddr->next;
 633                         if (curaddr->addr)
 634                                 free(curaddr->addr);
 635                         if (curaddr->netmask)
 636                                 free(curaddr->netmask);
 637                         if (curaddr->broadaddr)
 638                                 free(curaddr->broadaddr);
 639                         if (curaddr->dstaddr)
 640                                 free(curaddr->dstaddr);
 641                         free(curaddr);
 642                 }
 643
 644                 /*
 645                  * Free the name string.
 646                  */
 647                 free(curdev->name);
 648
 649                 /*
 650                  * Free the description string, if any.
 651                  */
 652                 if (curdev->description != NULL)
 653                         free(curdev->description);
 654
 655                 /*
 656                  * Free the interface.
 657                  */
 658                 free(curdev);
 659         }
 660 }
 661
 662 #if !defined(WIN32) && !defined(MSDOS)
 663
 664 /*
 665  * Return the name of a network interface attached to the system, or NULL
 666  * if none can be found.  The interface must be configured up; the
 667  * lowest unit number is preferred; loopback is ignored.
 668  */
 669 char *
 670 pcap_lookupdev(errbuf)
 671         register char *errbuf;
 672 {
 673         pcap_if_t *alldevs;
 674 /* for old BSD systems, including bsdi3 */
 675 #ifndef IF_NAMESIZE
 676 #define IF_NAMESIZE IFNAMSIZ
 677 #endif
 678         static char device[IF_NAMESIZE + 1];
 679         char *ret;
 680
 681         if (pcap_findalldevs(&alldevs, errbuf) == -1)
 682                 return (NULL);
 683
 684         if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
 685                 /*
 686                  * There are no devices on the list, or the first device
 687                  * on the list is a loopback device, which means there
 688                  * are no non-loopback devices on the list.  This means
 689                  * we can't return any device.
 690                  *
 691                  * XXX - why not return a loopback device?  If we can't
 692                  * capture on it, it won't be on the list, and if it's
 693                  * on the list, there aren't any non-loopback devices,
 694                  * so why not just supply it as the default device?
 695                  */
 696                 (void)strlcpy(errbuf, "no suitable device found",
 697                     PCAP_ERRBUF_SIZE);
 698                 ret = NULL;
 699         } else {
 700                 /*
 701                  * Return the name of the first device on the list.
 702                  */
 703                 (void)strlcpy(device, alldevs->name, sizeof(device));
 704                 ret = device;
 705         }
 706
 707         pcap_freealldevs(alldevs);
 708         return (ret);
 709 }
 710
 711 int
 712 pcap_lookupnet(device, netp, maskp, errbuf)
 713         register const char *device;
 714         register bpf_u_int32 *netp, *maskp;
 715         register char *errbuf;
 716 {
 717         register int fd;
 718         register struct sockaddr_in *sin4;
 719         struct ifreq ifr;
 720
 721         /*
 722          * The pseudo-device "any" listens on all interfaces and therefore
 723          * has the network address and -mask "0.0.0.0" therefore catching
 724          * all traffic. Using NULL for the interface is the same as "any".
 725          */
 726         if (!device || strcmp(device, "any") == 0
 727 #ifdef HAVE_DAG_API
 728             || strstr(device, "dag") != NULL
 729 #endif
 730 #ifdef HAVE_SEPTEL_API
 731             || strstr(device, "septel") != NULL
 732 #endif
 733 #ifdef PCAP_SUPPORT_BT
 734             || strstr(device, "bluetooth") != NULL
 735 #endif
 736 #ifdef PCAP_SUPPORT_USB
 737             || strstr(device, "usbmon") != NULL
 738 #endif
 739 #ifdef HAVE_SNF_API
 740             || strstr(device, "snf") != NULL
 741 #endif
 742             ) {
 743                 *netp = *maskp = 0;
 744                 return 0;
 745         }
 746
 747         fd = socket(AF_INET, SOCK_DGRAM, 0);
 748         if (fd < 0) {
 749                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
 750                     pcap_strerror(errno));
 751                 return (-1);
 752         }
 753         memset(&ifr, 0, sizeof(ifr));
 754 #ifdef linux
 755         /* XXX Work around Linux kernel bug */
 756         ifr.ifr_addr.sa_family = AF_INET;
 757 #endif
 758         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 759         if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
 760                 if (errno == EADDRNOTAVAIL) {
 761                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 762                             "%s: no IPv4 address assigned", device);
 763                 } else {
 764                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 765                             "SIOCGIFADDR: %s: %s",
 766                             device, pcap_strerror(errno));
 767                 }
 768                 (void)close(fd);
 769                 return (-1);
 770         }
 771         sin4 = (struct sockaddr_in *)&ifr.ifr_addr;
 772         *netp = sin4->sin_addr.s_addr;
 773         memset(&ifr, 0, sizeof(ifr));
 774 #ifdef linux
 775         /* XXX Work around Linux kernel bug */
 776         ifr.ifr_addr.sa_family = AF_INET;
 777 #endif
 778         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 779         if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
 780                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 781                     "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
 782                 (void)close(fd);
 783                 return (-1);
 784         }
 785         (void)close(fd);
 786         *maskp = sin4->sin_addr.s_addr;
 787         if (*maskp == 0) {
 788                 if (IN_CLASSA(*netp))
 789                         *maskp = IN_CLASSA_NET;
 790                 else if (IN_CLASSB(*netp))
 791                         *maskp = IN_CLASSB_NET;
 792                 else if (IN_CLASSC(*netp))
 793                         *maskp = IN_CLASSC_NET;
 794                 else {
 795                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 796                             "inet class for 0x%x unknown", *netp);
 797                         return (-1);
 798                 }
 799         }
 800         *netp &= *maskp;
 801         return (0);
 802 }
 803
 804 #elif defined(WIN32)
 805
 806 /*
 807  * Return the name of a network interface attached to the system, or NULL
 808  * if none can be found.  The interface must be configured up; the
 809  * lowest unit number is preferred; loopback is ignored.
 810  */
 811 char *
 812 pcap_lookupdev(errbuf)
 813         register char *errbuf;
 814 {
 815         DWORD dwVersion;
 816         DWORD dwWindowsMajorVersion;
 817         dwVersion = GetVersion();       /* get the OS version */
 818         dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
 819
 820         if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
 821                 /*
 822                  * Windows 95, 98, ME.
 823                  */
 824                 ULONG NameLength = 8192;
 825                 static char AdaptersName[8192];
 826
 827                 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
 828                         return (AdaptersName);
 829                 else
 830                         return NULL;
 831         } else {
 832                 /*
 833                  * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
 834                  */
 835                 ULONG NameLength = 8192;
 836                 static WCHAR AdaptersName[8192];
 837                 char *tAstr;
 838                 WCHAR *tUstr;
 839                 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
 840                 int NAdapts = 0;
 841
 842                 if(TAdaptersName == NULL)
 843                 {
 844                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
 845                         return NULL;
 846                 }
 847
 848                 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
 849                 {
 850                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 851                                 "PacketGetAdapterNames: %s",
 852                                 pcap_win32strerror());
 853                         free(TAdaptersName);
 854                         return NULL;
 855                 }
 856
 857
 858                 tAstr = (char*)TAdaptersName;
 859                 tUstr = (WCHAR*)AdaptersName;
 860
 861                 /*
 862                  * Convert and copy the device names
 863                  */
 864                 while(sscanf(tAstr, "%S", tUstr) > 0)
 865                 {
 866                         tAstr += strlen(tAstr) + 1;
 867                         tUstr += wcslen(tUstr) + 1;
 868                         NAdapts ++;
 869                 }
 870
 871                 tAstr++;
 872                 *tUstr = 0;
 873                 tUstr++;
 874
 875                 /*
 876                  * Copy the descriptions
 877                  */
 878                 while(NAdapts--)
 879                 {
 880                         char* tmp = (char*)tUstr;
 881                         strcpy(tmp, tAstr);
 882                         tmp += strlen(tAstr) + 1;
 883                         tUstr = (WCHAR*)tmp;
 884                         tAstr += strlen(tAstr) + 1;
 885                 }
 886
 887                 free(TAdaptersName);
 888                 return (char *)(AdaptersName);
 889         }
 890 }
 891
 892
 893 int
 894 pcap_lookupnet(device, netp, maskp, errbuf)
 895         register const char *device;
 896         register bpf_u_int32 *netp, *maskp;
 897         register char *errbuf;
 898 {
 899         /*
 900          * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
 901          * in order to skip non IPv4 (i.e. IPv6 addresses)
 902          */
 903         npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
 904         LONG if_addr_size = 1;
 905         struct sockaddr_in *t_addr;
 906         unsigned int i;
 907
 908         if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
 909                 *netp = *maskp = 0;
 910                 return (0);
 911         }
 912
 913         for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
 914         {
 915                 if(if_addrs[i].IPAddress.ss_family == AF_INET)
 916                 {
 917                         t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
 918                         *netp = t_addr->sin_addr.S_un.S_addr;
 919                         t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
 920                         *maskp = t_addr->sin_addr.S_un.S_addr;
 921
 922                         *netp &= *maskp;
 923                         return (0);
 924                 }
 925
 926         }
 927
 928         *netp = *maskp = 0;
 929         return (0);
 930 }
 931
 932 #endif /* !WIN32 && !MSDOS */