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 #ifdef HAVE_CONFIG_H
  36 #include "config.h"
  37 #endif
  38
  39 #ifdef WIN32
  40 #include <pcap-stdinc.h>
  41 #else /* WIN32 */
  42
  43 #include <sys/param.h>
  44 #ifndef MSDOS
  45 #include <sys/file.h>
  46 #endif
  47 #include <sys/ioctl.h>
  48 #include <sys/socket.h>
  49 #ifdef HAVE_SYS_SOCKIO_H
  50 #include <sys/sockio.h>
  51 #endif
  52
  53 struct mbuf;            /* Squelch compiler warnings on some platforms for */
  54 struct rtentry;         /* declarations in <net/if.h> */
  55 #include <net/if.h>
  56 #include <netinet/in.h>
  57 #endif /* WIN32 */
  58
  59 #include <ctype.h>
  60 #include <errno.h>
  61 #include <memory.h>
  62 #include <stdio.h>
  63 #include <stdlib.h>
  64 #include <string.h>
  65 #if !defined(WIN32) && !defined(__BORLANDC__)
  66 #include <unistd.h>
  67 #endif /* !WIN32 && !__BORLANDC__ */
  68 #ifdef HAVE_LIMITS_H
  69 #include <limits.h>
  70 #else
  71 #define INT_MAX         2147483647
  72 #endif
  73
  74 #include "pcap-int.h"
  75
  76 #ifdef HAVE_OS_PROTO_H
  77 #include "os-proto.h"
  78 #endif
  79
  80 /* Not all systems have IFF_LOOPBACK */
  81 #ifdef IFF_LOOPBACK
  82 #define ISLOOPBACK(name, flags) ((flags) & IFF_LOOPBACK)
  83 #else
  84 #define ISLOOPBACK(name, flags) ((name)[0] == 'l' && (name)[1] == 'o' && \
  85     (isdigit((unsigned char)((name)[2])) || (name)[2] == '\0'))
  86 #endif
  87
  88 #ifdef IFF_UP
  89 #define ISUP(flags) ((flags) & IFF_UP)
  90 #else
  91 #define ISUP(flags) 0
  92 #endif
  93
  94 #ifdef IFF_RUNNING
  95 #define ISRUNNING(flags) ((flags) & IFF_RUNNING)
  96 #else
  97 #define ISRUNNING(flags) 0
  98 #endif
  99
 100 struct sockaddr *
 101 dup_sockaddr(struct sockaddr *sa, size_t sa_length)
 102 {
 103         struct sockaddr *newsa;
 104
 105         if ((newsa = malloc(sa_length)) == NULL)
 106                 return (NULL);
 107         return (memcpy(newsa, sa, sa_length));
 108 }
 109
 110 static int
 111 get_instance(const char *name)
 112 {
 113         const char *cp, *endcp;
 114         int n;
 115
 116         if (strcmp(name, "any") == 0) {
 117                 /*
 118                  * Give the "any" device an artificially high instance
 119                  * number, so it shows up after all other non-loopback
 120                  * interfaces.
 121                  */
 122                 return INT_MAX;
 123         }
 124
 125         endcp = name + strlen(name);
 126         for (cp = name; cp < endcp && !isdigit((unsigned char)*cp); ++cp)
 127                 continue;
 128
 129         if (isdigit((unsigned char)*cp))
 130                 n = atoi(cp);
 131         else
 132                 n = 0;
 133         return (n);
 134 }
 135
 136 int
 137 add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
 138     u_int flags, const char *description, char *errbuf)
 139 {
 140         pcap_t *p;
 141         pcap_if_t *curdev, *prevdev, *nextdev;
 142         int this_instance;
 143         char open_errbuf[PCAP_ERRBUF_SIZE];
 144
 145         /*
 146          * Is there already an entry in the list for this interface?
 147          */
 148         for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
 149                 if (strcmp(name, curdev->name) == 0)
 150                         break;  /* yes, we found it */
 151         }
 152
 153         if (curdev == NULL) {
 154                 /*
 155                  * No, we didn't find it.
 156                  *
 157                  * Can we open this interface for live capture?
 158                  *
 159                  * We do this check so that interfaces that are
 160                  * supplied by the interface enumeration mechanism
 161                  * we're using but that don't support packet capture
 162                  * aren't included in the list.  Loopback interfaces
 163                  * on Solaris are an example of this; we don't just
 164                  * omit loopback interfaces on all platforms because
 165                  * you *can* capture on loopback interfaces on some
 166                  * OSes.
 167                  *
 168                  * On OS X, we don't do this check if the device
 169                  * name begins with "wlt"; at least some versions
 170                  * of OS X offer monitor mode capturing by having
 171                  * a separate "monitor mode" device for each wireless
 172                  * adapter, rather than by implementing the ioctls
 173                  * that {Free,Net,Open,DragonFly}BSD provide.
 174                  * Opening that device puts the adapter into monitor
 175                  * mode, which, at least for some adapters, causes
 176                  * them to deassociate from the network with which
 177                  * they're associated.
 178                  *
 179                  * Instead, we try to open the corresponding "en"
 180                  * device (so that we don't end up with, for users
 181                  * without sufficient privilege to open capture
 182                  * devices, a list of adapters that only includes
 183                  * the wlt devices).
 184                  */
 185 #ifdef __APPLE__
 186                 if (strncmp(name, "wlt", 3) == 0) {
 187                         char *en_name;
 188                         size_t en_name_len;
 189
 190                         /*
 191                          * Try to allocate a buffer for the "en"
 192                          * device's name.
 193                          */
 194                         en_name_len = strlen(name) - 1;
 195                         en_name = malloc(en_name_len + 1);
 196                         if (en_name == NULL) {
 197                                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 198                                     "malloc: %s", pcap_strerror(errno));
 199                                 return (-1);
 200                         }
 201                         strcpy(en_name, "en");
 202                         strcat(en_name, name + 3);
 203                         p = pcap_open_live(en_name, 68, 0, 0, open_errbuf);
 204                         free(en_name);
 205                 } else
 206 #endif /* __APPLE */
 207                 p = pcap_open_live(name, 68, 0, 0, open_errbuf);
 208                 if (p == NULL) {
 209                         /*
 210                          * No.  Don't bother including it.
 211                          * Don't treat this as an error, though.
 212                          */
 213                         *curdev_ret = NULL;
 214                         return (0);
 215                 }
 216                 pcap_close(p);
 217
 218                 /*
 219                  * Yes, we can open it.
 220                  * Allocate a new entry.
 221                  */
 222                 curdev = malloc(sizeof(pcap_if_t));
 223                 if (curdev == NULL) {
 224                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 225                             "malloc: %s", pcap_strerror(errno));
 226                         return (-1);
 227                 }
 228
 229                 /*
 230                  * Fill in the entry.
 231                  */
 232                 curdev->next = NULL;
 233                 curdev->name = strdup(name);
 234                 if (curdev->name == NULL) {
 235                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 236                             "malloc: %s", pcap_strerror(errno));
 237                         free(curdev);
 238                         return (-1);
 239                 }
 240                 if (description != NULL) {
 241                         /*
 242                          * We have a description for this interface.
 243                          */
 244                         curdev->description = strdup(description);
 245                         if (curdev->description == NULL) {
 246                                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 247                                     "malloc: %s", pcap_strerror(errno));
 248                                 free(curdev->name);
 249                                 free(curdev);
 250                                 return (-1);
 251                         }
 252                 } else {
 253                         /*
 254                          * We don't.
 255                          */
 256                         curdev->description = NULL;
 257                 }
 258                 curdev->addresses = NULL;       /* list starts out as empty */
 259                 curdev->flags = 0;
 260                 if (ISLOOPBACK(name, flags))
 261                         curdev->flags |= PCAP_IF_LOOPBACK;
 262                 if (ISUP(flags))
 263                         curdev->flags |= PCAP_IF_UP;
 264                 if (ISRUNNING(flags))
 265                         curdev->flags |= PCAP_IF_RUNNING;
 266
 267                 /*
 268                  * Add it to the list, in the appropriate location.
 269                  * First, get the instance number of this interface.
 270                  */
 271                 this_instance = get_instance(name);
 272
 273                 /*
 274                  * Now look for the last interface with an instance number
 275                  * less than or equal to the new interface's instance
 276                  * number - except that non-loopback interfaces are
 277                  * arbitrarily treated as having interface numbers less
 278                  * than those of loopback interfaces, so the loopback
 279                  * interfaces are put at the end of the list.
 280                  *
 281                  * We start with "prevdev" being NULL, meaning we're before
 282                  * the first element in the list.
 283                  */
 284                 prevdev = NULL;
 285                 for (;;) {
 286                         /*
 287                          * Get the interface after this one.
 288                          */
 289                         if (prevdev == NULL) {
 290                                 /*
 291                                  * The next element is the first element.
 292                                  */
 293                                 nextdev = *alldevs;
 294                         } else
 295                                 nextdev = prevdev->next;
 296
 297                         /*
 298                          * Are we at the end of the list?
 299                          */
 300                         if (nextdev == NULL) {
 301                                 /*
 302                                  * Yes - we have to put the new entry
 303                                  * after "prevdev".
 304                                  */
 305                                 break;
 306                         }
 307
 308                         /*
 309                          * Is the new interface a non-loopback interface
 310                          * and the next interface a loopback interface?
 311                          */
 312                         if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
 313                             (nextdev->flags & PCAP_IF_LOOPBACK)) {
 314                                 /*
 315                                  * Yes, we should put the new entry
 316                                  * before "nextdev", i.e. after "prevdev".
 317                                  */
 318                                 break;
 319                         }
 320
 321                         /*
 322                          * Is the new interface's instance number less
 323                          * than the next interface's instance number,
 324                          * and is it the case that the new interface is a
 325                          * non-loopback interface or the next interface is
 326                          * a loopback interface?
 327                          *
 328                          * (The goal of both loopback tests is to make
 329                          * sure that we never put a loopback interface
 330                          * before any non-loopback interface and that we
 331                          * always put a non-loopback interface before all
 332                          * loopback interfaces.)
 333                          */
 334                         if (this_instance < get_instance(nextdev->name) &&
 335                             (!(curdev->flags & PCAP_IF_LOOPBACK) ||
 336                                (nextdev->flags & PCAP_IF_LOOPBACK))) {
 337                                 /*
 338                                  * Yes - we should put the new entry
 339                                  * before "nextdev", i.e. after "prevdev".
 340                                  */
 341                                 break;
 342                         }
 343
 344                         prevdev = nextdev;
 345                 }
 346
 347                 /*
 348                  * Insert before "nextdev".
 349                  */
 350                 curdev->next = nextdev;
 351
 352                 /*
 353                  * Insert after "prevdev" - unless "prevdev" is null,
 354                  * in which case this is the first interface.
 355                  */
 356                 if (prevdev == NULL) {
 357                         /*
 358                          * This is the first interface.  Pass back a
 359                          * pointer to it, and put "curdev" before
 360                          * "nextdev".
 361                          */
 362                         *alldevs = curdev;
 363                 } else
 364                         prevdev->next = curdev;
 365         }
 366
 367         *curdev_ret = curdev;
 368         return (0);
 369 }
 370
 371 /*
 372  * XXX - on FreeBSDs that support it, should it get the sysctl named
 373  * "dev.{adapter family name}.{adapter unit}.%desc" to get a description
 374  * of the adapter?  Note that "dev.an.0.%desc" is "Aironet PC4500/PC4800"
 375  * with my Cisco 350 card, so the name isn't entirely descriptive.  The
 376  * "dev.an.0.%pnpinfo" has a better description, although one might argue
 377  * that the problem is really a driver bug - if it can find out that it's
 378  * a Cisco 340 or 350, rather than an old Aironet card, it should use
 379  * that in the description.
 380  *
 381  * Do NetBSD, DragonflyBSD, or OpenBSD support this as well?  FreeBSD
 382  * and OpenBSD let you get a description, but it's not generated by the OS,
 383  * it's set with another ioctl that ifconfig supports; we use that to get
 384  * a description in FreeBSD and OpenBSD, but if there is no such
 385  * description available, it still might be nice to get some description
 386  * string based on the device type or something such as that.
 387  *
 388  * In OS X, the System Configuration framework can apparently return
 389  * names in 10.4 and later.
 390  *
 391  * It also appears that freedesktop.org's HAL offers an "info.product"
 392  * string, but the HAL specification says it "should not be used in any
 393  * UI" and "subsystem/capability specific properties" should be used
 394  * instead and, in any case, I think HAL is being deprecated in
 395  * favor of other stuff such as DeviceKit.  DeviceKit doesn't appear
 396  * to have any obvious product information for devices, but maybe
 397  * I haven't looked hard enough.
 398  *
 399  * Using the System Configuration framework, or HAL, or DeviceKit, or
 400  * whatever, would require that libpcap applications be linked with
 401  * the frameworks/libraries in question.  That shouldn't be a problem
 402  * for programs linking with the shared version of libpcap (unless
 403  * you're running on AIX - which I think is the only UN*X that doesn't
 404  * support linking a shared library with other libraries on which it
 405  * depends, and having an executable linked only with the first shared
 406  * library automatically pick up the other libraries when started -
 407  * and using HAL or whatever).  Programs linked with the static
 408  * version of libpcap would have to use pcap-config with the --static
 409  * flag in order to get the right linker flags in order to pick up
 410  * the additional libraries/frameworks; those programs need that anyway
 411  * for libpcap 1.1 and beyond on Linux, as, by default, it requires
 412  * -lnl.
 413  *
 414  * Do any other UN*Xes, or desktop environments support getting a
 415  * description?
 416  */
 417 int
 418 add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags,
 419     struct sockaddr *addr, size_t addr_size,
 420     struct sockaddr *netmask, size_t netmask_size,
 421     struct sockaddr *broadaddr, size_t broadaddr_size,
 422     struct sockaddr *dstaddr, size_t dstaddr_size,
 423     char *errbuf)
 424 {
 425         pcap_if_t *curdev;
 426         char *description = NULL;
 427         pcap_addr_t *curaddr, *prevaddr, *nextaddr;
 428 #ifdef SIOCGIFDESCR
 429         int s;
 430         struct ifreq ifrdesc;
 431 #ifndef IFDESCRSIZE
 432         size_t descrlen = 64;
 433 #else
 434         size_t descrlen = IFDESCRSIZE;
 435 #endif /* IFDESCRSIZE */
 436 #endif /* SIOCGIFDESCR */
 437
 438 #ifdef SIOCGIFDESCR
 439         /*
 440          * Get the description for the interface.
 441          */
 442         memset(&ifrdesc, 0, sizeof ifrdesc);
 443         strlcpy(ifrdesc.ifr_name, name, sizeof ifrdesc.ifr_name);
 444         s = socket(AF_INET, SOCK_DGRAM, 0);
 445         if (s >= 0) {
 446 #ifdef __FreeBSD__
 447                 /*
 448                  * On FreeBSD, if the buffer isn't big enough for the
 449                  * description, the ioctl succeeds, but the description
 450                  * isn't copied, ifr_buffer.length is set to the description
 451                  * length, and ifr_buffer.buffer is set to NULL.
 452                  */
 453                 for (;;) {
 454                         free(description);
 455                         if ((description = malloc(descrlen)) != NULL) {
 456                                 ifrdesc.ifr_buffer.buffer = description;
 457                                 ifrdesc.ifr_buffer.length = descrlen;
 458                                 if (ioctl(s, SIOCGIFDESCR, &ifrdesc) == 0) {
 459                                         if (ifrdesc.ifr_buffer.buffer ==
 460                                             description)
 461                                                 break;
 462                                         else
 463                                                 descrlen = ifrdesc.ifr_buffer.length;
 464                                 } else {
 465                                         /*
 466                                          * Failed to get interface description.
 467                                          */
 468                                         free(description);
 469                                         description = NULL;
 470                                         break;
 471                                 }
 472                         } else
 473                                 break;
 474                 }
 475 #else /* __FreeBSD__ */
 476                 /*
 477                  * The only other OS that currently supports
 478                  * SIOCGIFDESCR is OpenBSD, and it has no way
 479                  * to get the description length - it's clamped
 480                  * to a maximum of IFDESCRSIZE.
 481                  */
 482                 if ((description = malloc(descrlen)) != NULL) {
 483                         ifrdesc.ifr_data = (caddr_t)description;
 484                         if (ioctl(s, SIOCGIFDESCR, &ifrdesc) != 0) {
 485                                 /*
 486                                  * Failed to get interface description.
 487                                  */
 488                                 free(description);
 489                                 description = NULL;
 490                         }
 491                 }
 492 #endif /* __FreeBSD__ */
 493                 close(s);
 494                 if (description != NULL && strlen(description) == 0) {
 495                         free(description);
 496                         description = NULL;
 497                 }
 498         }
 499 #endif /* SIOCGIFDESCR */
 500
 501         if (add_or_find_if(&curdev, alldevs, name, flags, description,
 502             errbuf) == -1) {
 503                 free(description);
 504                 /*
 505                  * Error - give up.
 506                  */
 507                 return (-1);
 508         }
 509         free(description);
 510         if (curdev == NULL) {
 511                 /*
 512                  * Device wasn't added because it can't be opened.
 513                  * Not a fatal error.
 514                  */
 515                 return (0);
 516         }
 517
 518         /*
 519          * "curdev" is an entry for this interface; add an entry for this
 520          * address to its list of addresses.
 521          *
 522          * Allocate the new entry and fill it in.
 523          */
 524         curaddr = malloc(sizeof(pcap_addr_t));
 525         if (curaddr == NULL) {
 526                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 527                     "malloc: %s", pcap_strerror(errno));
 528                 return (-1);
 529         }
 530
 531         curaddr->next = NULL;
 532         if (addr != NULL) {
 533                 curaddr->addr = dup_sockaddr(addr, addr_size);
 534                 if (curaddr->addr == NULL) {
 535                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 536                             "malloc: %s", pcap_strerror(errno));
 537                         free(curaddr);
 538                         return (-1);
 539                 }
 540         } else
 541                 curaddr->addr = NULL;
 542
 543         if (netmask != NULL) {
 544                 curaddr->netmask = dup_sockaddr(netmask, netmask_size);
 545                 if (curaddr->netmask == NULL) {
 546                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 547                             "malloc: %s", pcap_strerror(errno));
 548                         if (curaddr->addr != NULL)
 549                                 free(curaddr->addr);
 550                         free(curaddr);
 551                         return (-1);
 552                 }
 553         } else
 554                 curaddr->netmask = NULL;
 555
 556         if (broadaddr != NULL) {
 557                 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size);
 558                 if (curaddr->broadaddr == NULL) {
 559                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 560                             "malloc: %s", pcap_strerror(errno));
 561                         if (curaddr->netmask != NULL)
 562                                 free(curaddr->netmask);
 563                         if (curaddr->addr != NULL)
 564                                 free(curaddr->addr);
 565                         free(curaddr);
 566                         return (-1);
 567                 }
 568         } else
 569                 curaddr->broadaddr = NULL;
 570
 571         if (dstaddr != NULL) {
 572                 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size);
 573                 if (curaddr->dstaddr == NULL) {
 574                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 575                             "malloc: %s", pcap_strerror(errno));
 576                         if (curaddr->broadaddr != NULL)
 577                                 free(curaddr->broadaddr);
 578                         if (curaddr->netmask != NULL)
 579                                 free(curaddr->netmask);
 580                         if (curaddr->addr != NULL)
 581                                 free(curaddr->addr);
 582                         free(curaddr);
 583                         return (-1);
 584                 }
 585         } else
 586                 curaddr->dstaddr = NULL;
 587
 588         /*
 589          * Find the end of the list of addresses.
 590          */
 591         for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
 592                 nextaddr = prevaddr->next;
 593                 if (nextaddr == NULL) {
 594                         /*
 595                          * This is the end of the list.
 596                          */
 597                         break;
 598                 }
 599         }
 600
 601         if (prevaddr == NULL) {
 602                 /*
 603                  * The list was empty; this is the first member.
 604                  */
 605                 curdev->addresses = curaddr;
 606         } else {
 607                 /*
 608                  * "prevaddr" is the last member of the list; append
 609                  * this member to it.
 610                  */
 611                 prevaddr->next = curaddr;
 612         }
 613
 614         return (0);
 615 }
 616
 617 int
 618 pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags,
 619     const char *description, char *errbuf)
 620 {
 621         pcap_if_t *curdev;
 622
 623         return (add_or_find_if(&curdev, devlist, name, flags, description,
 624             errbuf));
 625 }
 626
 627
 628 /*
 629  * Free a list of interfaces.
 630  */
 631 void
 632 pcap_freealldevs(pcap_if_t *alldevs)
 633 {
 634         pcap_if_t *curdev, *nextdev;
 635         pcap_addr_t *curaddr, *nextaddr;
 636
 637         for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
 638                 nextdev = curdev->next;
 639
 640                 /*
 641                  * Free all addresses.
 642                  */
 643                 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
 644                         nextaddr = curaddr->next;
 645                         if (curaddr->addr)
 646                                 free(curaddr->addr);
 647                         if (curaddr->netmask)
 648                                 free(curaddr->netmask);
 649                         if (curaddr->broadaddr)
 650                                 free(curaddr->broadaddr);
 651                         if (curaddr->dstaddr)
 652                                 free(curaddr->dstaddr);
 653                         free(curaddr);
 654                 }
 655
 656                 /*
 657                  * Free the name string.
 658                  */
 659                 free(curdev->name);
 660
 661                 /*
 662                  * Free the description string, if any.
 663                  */
 664                 if (curdev->description != NULL)
 665                         free(curdev->description);
 666
 667                 /*
 668                  * Free the interface.
 669                  */
 670                 free(curdev);
 671         }
 672 }
 673
 674 #if !defined(WIN32) && !defined(MSDOS)
 675
 676 /*
 677  * Return the name of a network interface attached to the system, or NULL
 678  * if none can be found.  The interface must be configured up; the
 679  * lowest unit number is preferred; loopback is ignored.
 680  */
 681 char *
 682 pcap_lookupdev(errbuf)
 683         register char *errbuf;
 684 {
 685         pcap_if_t *alldevs;
 686 /* for old BSD systems, including bsdi3 */
 687 #ifndef IF_NAMESIZE
 688 #define IF_NAMESIZE IFNAMSIZ
 689 #endif
 690         static char device[IF_NAMESIZE + 1];
 691         char *ret;
 692
 693         if (pcap_findalldevs(&alldevs, errbuf) == -1)
 694                 return (NULL);
 695
 696         if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
 697                 /*
 698                  * There are no devices on the list, or the first device
 699                  * on the list is a loopback device, which means there
 700                  * are no non-loopback devices on the list.  This means
 701                  * we can't return any device.
 702                  *
 703                  * XXX - why not return a loopback device?  If we can't
 704                  * capture on it, it won't be on the list, and if it's
 705                  * on the list, there aren't any non-loopback devices,
 706                  * so why not just supply it as the default device?
 707                  */
 708                 (void)strlcpy(errbuf, "no suitable device found",
 709                     PCAP_ERRBUF_SIZE);
 710                 ret = NULL;
 711         } else {
 712                 /*
 713                  * Return the name of the first device on the list.
 714                  */
 715                 (void)strlcpy(device, alldevs->name, sizeof(device));
 716                 ret = device;
 717         }
 718
 719         pcap_freealldevs(alldevs);
 720         return (ret);
 721 }
 722
 723 int
 724 pcap_lookupnet(device, netp, maskp, errbuf)
 725         register const char *device;
 726         register bpf_u_int32 *netp, *maskp;
 727         register char *errbuf;
 728 {
 729         register int fd;
 730         register struct sockaddr_in *sin4;
 731         struct ifreq ifr;
 732
 733         /*
 734          * The pseudo-device "any" listens on all interfaces and therefore
 735          * has the network address and -mask "0.0.0.0" therefore catching
 736          * all traffic. Using NULL for the interface is the same as "any".
 737          */
 738         if (!device || strcmp(device, "any") == 0
 739 #ifdef HAVE_DAG_API
 740             || strstr(device, "dag") != NULL
 741 #endif
 742 #ifdef HAVE_SEPTEL_API
 743             || strstr(device, "septel") != NULL
 744 #endif
 745 #ifdef PCAP_SUPPORT_BT
 746             || strstr(device, "bluetooth") != NULL
 747 #endif
 748 #ifdef PCAP_SUPPORT_USB
 749             || strstr(device, "usbmon") != NULL
 750 #endif
 751 #ifdef HAVE_SNF_API
 752             || strstr(device, "snf") != NULL
 753 #endif
 754             ) {
 755                 *netp = *maskp = 0;
 756                 return 0;
 757         }
 758
 759         fd = socket(AF_INET, SOCK_DGRAM, 0);
 760         if (fd < 0) {
 761                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
 762                     pcap_strerror(errno));
 763                 return (-1);
 764         }
 765         memset(&ifr, 0, sizeof(ifr));
 766 #ifdef linux
 767         /* XXX Work around Linux kernel bug */
 768         ifr.ifr_addr.sa_family = AF_INET;
 769 #endif
 770         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 771         if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
 772                 if (errno == EADDRNOTAVAIL) {
 773                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 774                             "%s: no IPv4 address assigned", device);
 775                 } else {
 776                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 777                             "SIOCGIFADDR: %s: %s",
 778                             device, pcap_strerror(errno));
 779                 }
 780                 (void)close(fd);
 781                 return (-1);
 782         }
 783         sin4 = (struct sockaddr_in *)&ifr.ifr_addr;
 784         *netp = sin4->sin_addr.s_addr;
 785         memset(&ifr, 0, sizeof(ifr));
 786 #ifdef linux
 787         /* XXX Work around Linux kernel bug */
 788         ifr.ifr_addr.sa_family = AF_INET;
 789 #endif
 790         (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 791         if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
 792                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 793                     "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
 794                 (void)close(fd);
 795                 return (-1);
 796         }
 797         (void)close(fd);
 798         *maskp = sin4->sin_addr.s_addr;
 799         if (*maskp == 0) {
 800                 if (IN_CLASSA(*netp))
 801                         *maskp = IN_CLASSA_NET;
 802                 else if (IN_CLASSB(*netp))
 803                         *maskp = IN_CLASSB_NET;
 804                 else if (IN_CLASSC(*netp))
 805                         *maskp = IN_CLASSC_NET;
 806                 else {
 807                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 808                             "inet class for 0x%x unknown", *netp);
 809                         return (-1);
 810                 }
 811         }
 812         *netp &= *maskp;
 813         return (0);
 814 }
 815
 816 #elif defined(WIN32)
 817
 818 /*
 819  * Return the name of a network interface attached to the system, or NULL
 820  * if none can be found.  The interface must be configured up; the
 821  * lowest unit number is preferred; loopback is ignored.
 822  */
 823 char *
 824 pcap_lookupdev(errbuf)
 825         register char *errbuf;
 826 {
 827         DWORD dwVersion;
 828         DWORD dwWindowsMajorVersion;
 829         dwVersion = GetVersion();       /* get the OS version */
 830         dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));
 831
 832         if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
 833                 /*
 834                  * Windows 95, 98, ME.
 835                  */
 836                 ULONG NameLength = 8192;
 837                 static char AdaptersName[8192];
 838
 839                 if (PacketGetAdapterNames(AdaptersName,&NameLength) )
 840                         return (AdaptersName);
 841                 else
 842                         return NULL;
 843         } else {
 844                 /*
 845                  * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility
 846                  */
 847                 ULONG NameLength = 8192;
 848                 static WCHAR AdaptersName[8192];
 849                 char *tAstr;
 850                 WCHAR *tUstr;
 851                 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR));
 852                 int NAdapts = 0;
 853
 854                 if(TAdaptersName == NULL)
 855                 {
 856                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
 857                         return NULL;
 858                 }
 859
 860                 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
 861                 {
 862                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 863                                 "PacketGetAdapterNames: %s",
 864                                 pcap_win32strerror());
 865                         free(TAdaptersName);
 866                         return NULL;
 867                 }
 868
 869
 870                 tAstr = (char*)TAdaptersName;
 871                 tUstr = (WCHAR*)AdaptersName;
 872
 873                 /*
 874                  * Convert and copy the device names
 875                  */
 876                 while(sscanf(tAstr, "%S", tUstr) > 0)
 877                 {
 878                         tAstr += strlen(tAstr) + 1;
 879                         tUstr += wcslen(tUstr) + 1;
 880                         NAdapts ++;
 881                 }
 882
 883                 tAstr++;
 884                 *tUstr = 0;
 885                 tUstr++;
 886
 887                 /*
 888                  * Copy the descriptions
 889                  */
 890                 while(NAdapts--)
 891                 {
 892                         char* tmp = (char*)tUstr;
 893                         strcpy(tmp, tAstr);
 894                         tmp += strlen(tAstr) + 1;
 895                         tUstr = (WCHAR*)tmp;
 896                         tAstr += strlen(tAstr) + 1;
 897                 }
 898
 899                 free(TAdaptersName);
 900                 return (char *)(AdaptersName);
 901         }
 902 }
 903
 904
 905 int
 906 pcap_lookupnet(device, netp, maskp, errbuf)
 907         register const char *device;
 908         register bpf_u_int32 *netp, *maskp;
 909         register char *errbuf;
 910 {
 911         /*
 912          * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
 913          * in order to skip non IPv4 (i.e. IPv6 addresses)
 914          */
 915         npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
 916         LONG if_addr_size = 1;
 917         struct sockaddr_in *t_addr;
 918         unsigned int i;
 919
 920         if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
 921                 *netp = *maskp = 0;
 922                 return (0);
 923         }
 924
 925         for(i=0; i<MAX_NETWORK_ADDRESSES; i++)
 926         {
 927                 if(if_addrs[i].IPAddress.ss_family == AF_INET)
 928                 {
 929                         t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
 930                         *netp = t_addr->sin_addr.S_un.S_addr;
 931                         t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
 932                         *maskp = t_addr->sin_addr.S_un.S_addr;
 933
 934                         *netp &= *maskp;
 935                         return (0);
 936                 }
 937
 938         }
 939
 940         *netp = *maskp = 0;
 941         return (0);
 942 }
 943
 944 #endif /* !WIN32 && !MSDOS */