inet.c revision 146768
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 36static const char rcsid[] _U_ = 37 "@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.66 2005/02/10 19:38:06 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 58struct mbuf; /* Squelch compiler warnings on some platforms for */ 59struct 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 93struct sockaddr * 94dup_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 103static int 104get_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 129int 130add_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 * Can we open this interface for live capture? 139 * 140 * We do this check so that interfaces that ae supplied 141 * by the interface enumeration mechanism we're using 142 * but that don't support packet capture aren't included 143 * in the list. An example of this is loopback interfaces 144 * on Solaris; we don't just omit loopback interfaces 145 * becaue you *can* capture on loopback interfaces on some 146 * OSes. 147 */ 148 p = pcap_open_live(name, 68, 0, 0, errbuf); 149 if (p == NULL) { 150 /* 151 * No. Don't bother including it. 152 * Don't treat this as an error, though. 153 */ 154 *curdev_ret = NULL; 155 return (0); 156 } 157 pcap_close(p); 158 159 /* 160 * Is there already an entry in the list for this interface? 161 */ 162 for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) { 163 if (strcmp(name, curdev->name) == 0) 164 break; /* yes, we found it */ 165 } 166 if (curdev == NULL) { 167 /* 168 * No, we didn't find it. 169 * Allocate a new entry. 170 */ 171 curdev = malloc(sizeof(pcap_if_t)); 172 if (curdev == NULL) { 173 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 174 "malloc: %s", pcap_strerror(errno)); 175 return (-1); 176 } 177 178 /* 179 * Fill in the entry. 180 */ 181 curdev->next = NULL; 182 curdev->name = malloc(strlen(name) + 1); 183 strcpy(curdev->name, name); 184 if (description != NULL) { 185 /* 186 * We have a description for this interface. 187 */ 188 curdev->description = malloc(strlen(description) + 1); 189 strcpy(curdev->description, description); 190 } else { 191 /* 192 * We don't. 193 */ 194 curdev->description = NULL; 195 } 196 curdev->addresses = NULL; /* list starts out as empty */ 197 curdev->flags = 0; 198 if (ISLOOPBACK(name, flags)) 199 curdev->flags |= PCAP_IF_LOOPBACK; 200 201 /* 202 * Add it to the list, in the appropriate location. 203 * First, get the instance number of this interface. 204 */ 205 this_instance = get_instance(name); 206 207 /* 208 * Now look for the last interface with an instance number 209 * less than or equal to the new interface's instance 210 * number - except that non-loopback interfaces are 211 * arbitrarily treated as having interface numbers less 212 * than those of loopback interfaces, so the loopback 213 * interfaces are put at the end of the list. 214 * 215 * We start with "prevdev" being NULL, meaning we're before 216 * the first element in the list. 217 */ 218 prevdev = NULL; 219 for (;;) { 220 /* 221 * Get the interface after this one. 222 */ 223 if (prevdev == NULL) { 224 /* 225 * The next element is the first element. 226 */ 227 nextdev = *alldevs; 228 } else 229 nextdev = prevdev->next; 230 231 /* 232 * Are we at the end of the list? 233 */ 234 if (nextdev == NULL) { 235 /* 236 * Yes - we have to put the new entry 237 * after "prevdev". 238 */ 239 break; 240 } 241 242 /* 243 * Is the new interface a non-loopback interface 244 * and the next interface a loopback interface? 245 */ 246 if (!(curdev->flags & PCAP_IF_LOOPBACK) && 247 (nextdev->flags & PCAP_IF_LOOPBACK)) { 248 /* 249 * Yes, we should put the new entry 250 * before "nextdev", i.e. after "prevdev". 251 */ 252 break; 253 } 254 255 /* 256 * Is the new interface's instance number less 257 * than the next interface's instance number, 258 * and is it the case that the new interface is a 259 * non-loopback interface or the next interface is 260 * a loopback interface? 261 * 262 * (The goal of both loopback tests is to make 263 * sure that we never put a loopback interface 264 * before any non-loopback interface and that we 265 * always put a non-loopback interface before all 266 * loopback interfaces.) 267 */ 268 if (this_instance < get_instance(nextdev->name) && 269 (!(curdev->flags & PCAP_IF_LOOPBACK) || 270 (nextdev->flags & PCAP_IF_LOOPBACK))) { 271 /* 272 * Yes - we should put the new entry 273 * before "nextdev", i.e. after "prevdev". 274 */ 275 break; 276 } 277 278 prevdev = nextdev; 279 } 280 281 /* 282 * Insert before "nextdev". 283 */ 284 curdev->next = nextdev; 285 286 /* 287 * Insert after "prevdev" - unless "prevdev" is null, 288 * in which case this is the first interface. 289 */ 290 if (prevdev == NULL) { 291 /* 292 * This is the first interface. Pass back a 293 * pointer to it, and put "curdev" before 294 * "nextdev". 295 */ 296 *alldevs = curdev; 297 } else 298 prevdev->next = curdev; 299 } 300 301 *curdev_ret = curdev; 302 return (0); 303} 304 305int 306add_addr_to_iflist(pcap_if_t **alldevs, const char *name, u_int flags, 307 struct sockaddr *addr, size_t addr_size, 308 struct sockaddr *netmask, size_t netmask_size, 309 struct sockaddr *broadaddr, size_t broadaddr_size, 310 struct sockaddr *dstaddr, size_t dstaddr_size, 311 char *errbuf) 312{ 313 pcap_if_t *curdev; 314 pcap_addr_t *curaddr, *prevaddr, *nextaddr; 315 316 if (add_or_find_if(&curdev, alldevs, name, flags, NULL, errbuf) == -1) { 317 /* 318 * Error - give up. 319 */ 320 return (-1); 321 } 322 if (curdev == NULL) { 323 /* 324 * Device wasn't added because it can't be opened. 325 * Not a fatal error. 326 */ 327 return (0); 328 } 329 330 /* 331 * "curdev" is an entry for this interface; add an entry for this 332 * address to its list of addresses. 333 * 334 * Allocate the new entry and fill it in. 335 */ 336 curaddr = malloc(sizeof(pcap_addr_t)); 337 if (curaddr == NULL) { 338 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 339 "malloc: %s", pcap_strerror(errno)); 340 return (-1); 341 } 342 343 curaddr->next = NULL; 344 if (addr != NULL) { 345 curaddr->addr = dup_sockaddr(addr, addr_size); 346 if (curaddr->addr == NULL) { 347 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 348 "malloc: %s", pcap_strerror(errno)); 349 free(curaddr); 350 return (-1); 351 } 352 } else 353 curaddr->addr = NULL; 354 355 if (netmask != NULL) { 356 curaddr->netmask = dup_sockaddr(netmask, netmask_size); 357 if (curaddr->netmask == NULL) { 358 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 359 "malloc: %s", pcap_strerror(errno)); 360 free(curaddr); 361 return (-1); 362 } 363 } else 364 curaddr->netmask = NULL; 365 366 if (broadaddr != NULL) { 367 curaddr->broadaddr = dup_sockaddr(broadaddr, broadaddr_size); 368 if (curaddr->broadaddr == NULL) { 369 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 370 "malloc: %s", pcap_strerror(errno)); 371 free(curaddr); 372 return (-1); 373 } 374 } else 375 curaddr->broadaddr = NULL; 376 377 if (dstaddr != NULL) { 378 curaddr->dstaddr = dup_sockaddr(dstaddr, dstaddr_size); 379 if (curaddr->dstaddr == NULL) { 380 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 381 "malloc: %s", pcap_strerror(errno)); 382 free(curaddr); 383 return (-1); 384 } 385 } else 386 curaddr->dstaddr = NULL; 387 388 /* 389 * Find the end of the list of addresses. 390 */ 391 for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) { 392 nextaddr = prevaddr->next; 393 if (nextaddr == NULL) { 394 /* 395 * This is the end of the list. 396 */ 397 break; 398 } 399 } 400 401 if (prevaddr == NULL) { 402 /* 403 * The list was empty; this is the first member. 404 */ 405 curdev->addresses = curaddr; 406 } else { 407 /* 408 * "prevaddr" is the last member of the list; append 409 * this member to it. 410 */ 411 prevaddr->next = curaddr; 412 } 413 414 return (0); 415} 416 417int 418pcap_add_if(pcap_if_t **devlist, const char *name, u_int flags, 419 const char *description, char *errbuf) 420{ 421 pcap_if_t *curdev; 422 423 return (add_or_find_if(&curdev, devlist, name, flags, description, 424 errbuf)); 425} 426 427 428/* 429 * Free a list of interfaces. 430 */ 431void 432pcap_freealldevs(pcap_if_t *alldevs) 433{ 434 pcap_if_t *curdev, *nextdev; 435 pcap_addr_t *curaddr, *nextaddr; 436 437 for (curdev = alldevs; curdev != NULL; curdev = nextdev) { 438 nextdev = curdev->next; 439 440 /* 441 * Free all addresses. 442 */ 443 for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) { 444 nextaddr = curaddr->next; 445 if (curaddr->addr) 446 free(curaddr->addr); 447 if (curaddr->netmask) 448 free(curaddr->netmask); 449 if (curaddr->broadaddr) 450 free(curaddr->broadaddr); 451 if (curaddr->dstaddr) 452 free(curaddr->dstaddr); 453 free(curaddr); 454 } 455 456 /* 457 * Free the name string. 458 */ 459 free(curdev->name); 460 461 /* 462 * Free the description string, if any. 463 */ 464 if (curdev->description != NULL) 465 free(curdev->description); 466 467 /* 468 * Free the interface. 469 */ 470 free(curdev); 471 } 472} 473 474#if !defined(WIN32) && !defined(MSDOS) 475 476/* 477 * Return the name of a network interface attached to the system, or NULL 478 * if none can be found. The interface must be configured up; the 479 * lowest unit number is preferred; loopback is ignored. 480 */ 481char * 482pcap_lookupdev(errbuf) 483 register char *errbuf; 484{ 485 pcap_if_t *alldevs; 486/* for old BSD systems, including bsdi3 */ 487#ifndef IF_NAMESIZE 488#define IF_NAMESIZE IFNAMSIZ 489#endif 490 static char device[IF_NAMESIZE + 1]; 491 char *ret; 492 493 if (pcap_findalldevs(&alldevs, errbuf) == -1) 494 return (NULL); 495 496 if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) { 497 /* 498 * There are no devices on the list, or the first device 499 * on the list is a loopback device, which means there 500 * are no non-loopback devices on the list. This means 501 * we can't return any device. 502 * 503 * XXX - why not return a loopback device? If we can't 504 * capture on it, it won't be on the list, and if it's 505 * on the list, there aren't any non-loopback devices, 506 * so why not just supply it as the default device? 507 */ 508 (void)strlcpy(errbuf, "no suitable device found", 509 PCAP_ERRBUF_SIZE); 510 ret = NULL; 511 } else { 512 /* 513 * Return the name of the first device on the list. 514 */ 515 (void)strlcpy(device, alldevs->name, sizeof(device)); 516 ret = device; 517 } 518 519 pcap_freealldevs(alldevs); 520 return (ret); 521} 522 523int 524pcap_lookupnet(device, netp, maskp, errbuf) 525 register const char *device; 526 register bpf_u_int32 *netp, *maskp; 527 register char *errbuf; 528{ 529 register int fd; 530 register struct sockaddr_in *sin; 531 struct ifreq ifr; 532 533 /* 534 * The pseudo-device "any" listens on all interfaces and therefore 535 * has the network address and -mask "0.0.0.0" therefore catching 536 * all traffic. Using NULL for the interface is the same as "any". 537 */ 538 if (!device || strcmp(device, "any") == 0 539#ifdef HAVE_DAG_API 540 || strstr(device, "dag") != NULL 541#endif 542 ) { 543 *netp = *maskp = 0; 544 return 0; 545 } 546 547 fd = socket(AF_INET, SOCK_DGRAM, 0); 548 if (fd < 0) { 549 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s", 550 pcap_strerror(errno)); 551 return (-1); 552 } 553 memset(&ifr, 0, sizeof(ifr)); 554#ifdef linux 555 /* XXX Work around Linux kernel bug */ 556 ifr.ifr_addr.sa_family = AF_INET; 557#endif 558 (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 559 if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) { 560 if (errno == EADDRNOTAVAIL) { 561 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 562 "%s: no IPv4 address assigned", device); 563 } else { 564 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 565 "SIOCGIFADDR: %s: %s", 566 device, pcap_strerror(errno)); 567 } 568 (void)close(fd); 569 return (-1); 570 } 571 sin = (struct sockaddr_in *)&ifr.ifr_addr; 572 *netp = sin->sin_addr.s_addr; 573 if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) { 574 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 575 "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno)); 576 (void)close(fd); 577 return (-1); 578 } 579 (void)close(fd); 580 *maskp = sin->sin_addr.s_addr; 581 if (*maskp == 0) { 582 if (IN_CLASSA(*netp)) 583 *maskp = IN_CLASSA_NET; 584 else if (IN_CLASSB(*netp)) 585 *maskp = IN_CLASSB_NET; 586 else if (IN_CLASSC(*netp)) 587 *maskp = IN_CLASSC_NET; 588 else { 589 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 590 "inet class for 0x%x unknown", *netp); 591 return (-1); 592 } 593 } 594 *netp &= *maskp; 595 return (0); 596} 597 598#elif defined(WIN32) 599 600/* 601 * Return the name of a network interface attached to the system, or NULL 602 * if none can be found. The interface must be configured up; the 603 * lowest unit number is preferred; loopback is ignored. 604 */ 605char * 606pcap_lookupdev(errbuf) 607 register char *errbuf; 608{ 609 DWORD dwVersion; 610 DWORD dwWindowsMajorVersion; 611 dwVersion = GetVersion(); /* get the OS version */ 612 dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion))); 613 614 if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) { 615 /* 616 * Windows 95, 98, ME. 617 */ 618 ULONG NameLength = 8192; 619 static char AdaptersName[8192]; 620 621 if (PacketGetAdapterNames(AdaptersName,&NameLength) ) 622 return (AdaptersName); 623 else 624 return NULL; 625 } else { 626 /* 627 * Windows NT (NT 4.0, W2K, WXP). Convert the names to UNICODE for backward compatibility 628 */ 629 ULONG NameLength = 8192; 630 static WCHAR AdaptersName[8192]; 631 char *tAstr; 632 WCHAR *tUstr; 633 WCHAR *TAdaptersName = (WCHAR*)malloc(8192 * sizeof(WCHAR)); 634 int NAdapts = 0; 635 636 if(TAdaptersName == NULL) 637 { 638 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure"); 639 return NULL; 640 } 641 642 if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) ) 643 { 644 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 645 "PacketGetAdapterNames: %s", 646 pcap_win32strerror()); 647 free(TAdaptersName); 648 return NULL; 649 } 650 651 652 tAstr = (char*)TAdaptersName; 653 tUstr = (WCHAR*)AdaptersName; 654 655 /* 656 * Convert and copy the device names 657 */ 658 while(sscanf(tAstr, "%S", tUstr) > 0) 659 { 660 tAstr += strlen(tAstr) + 1; 661 tUstr += wcslen(tUstr) + 1; 662 NAdapts ++; 663 } 664 665 tAstr++; 666 *tUstr = 0; 667 tUstr++; 668 669 /* 670 * Copy the descriptions 671 */ 672 while(NAdapts--) 673 { 674 strcpy((char*)tUstr, tAstr); 675 (char*)tUstr += strlen(tAstr) + 1;; 676 tAstr += strlen(tAstr) + 1; 677 } 678 679 free(TAdaptersName); 680 return (char *)(AdaptersName); 681 } 682} 683 684 685int 686pcap_lookupnet(device, netp, maskp, errbuf) 687 register const char *device; 688 register bpf_u_int32 *netp, *maskp; 689 register char *errbuf; 690{ 691 /* 692 * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo() 693 * in order to skip non IPv4 (i.e. IPv6 addresses) 694 */ 695 npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES]; 696 LONG if_addr_size = 1; 697 struct sockaddr_in *t_addr; 698 unsigned int i; 699 700 if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) { 701 *netp = *maskp = 0; 702 return (0); 703 } 704 705 for(i=0; i<MAX_NETWORK_ADDRESSES; i++) 706 { 707 if(if_addrs[i].IPAddress.ss_family == AF_INET) 708 { 709 t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress); 710 *netp = t_addr->sin_addr.S_un.S_addr; 711 t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask); 712 *maskp = t_addr->sin_addr.S_un.S_addr; 713 714 *netp &= *maskp; 715 return (0); 716 } 717 718 } 719 720 *netp = *maskp = 0; 721 return (0); 722} 723 724#endif /* !WIN32 && !MSDOS */ 725