pcap.c revision 127664
1/* 2 * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the Computer Systems 16 * Engineering Group at Lawrence Berkeley Laboratory. 17 * 4. Neither the name of the University nor of the Laboratory may be used 18 * to endorse or promote products derived from this software without 19 * specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#ifndef lint 35static const char rcsid[] _U_ = 36 "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.63.2.9 2004/03/25 22:40:52 guy Exp $ (LBL)"; 37#endif 38 39#ifdef HAVE_CONFIG_H 40#include "config.h" 41#endif 42 43#ifdef WIN32 44#include <pcap-stdinc.h> 45#else /* WIN32 */ 46#include <sys/types.h> 47#endif /* WIN32 */ 48 49#include <stdio.h> 50#include <stdlib.h> 51#include <string.h> 52#ifndef _MSC_VER 53#include <unistd.h> 54#endif 55#include <fcntl.h> 56#include <errno.h> 57 58#ifdef HAVE_OS_PROTO_H 59#include "os-proto.h" 60#endif 61 62#include "pcap-int.h" 63 64#ifdef HAVE_DAG_API 65#include <dagnew.h> 66#include <dagapi.h> 67#endif 68 69int 70pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 71{ 72 73 return p->read_op(p, cnt, callback, user); 74} 75 76/* 77 * XXX - is this necessary? 78 */ 79int 80pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 81{ 82 83 return p->read_op(p, cnt, callback, user); 84} 85 86int 87pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 88{ 89 register int n; 90 91 for (;;) { 92 if (p->sf.rfile != NULL) { 93 /* 94 * 0 means EOF, so don't loop if we get 0. 95 */ 96 n = pcap_offline_read(p, cnt, callback, user); 97 } else { 98 /* 99 * XXX keep reading until we get something 100 * (or an error occurs) 101 */ 102 do { 103 n = p->read_op(p, cnt, callback, user); 104 } while (n == 0); 105 } 106 if (n <= 0) 107 return (n); 108 if (cnt > 0) { 109 cnt -= n; 110 if (cnt <= 0) 111 return (0); 112 } 113 } 114} 115 116struct singleton { 117 struct pcap_pkthdr *hdr; 118 const u_char *pkt; 119}; 120 121 122static void 123pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt) 124{ 125 struct singleton *sp = (struct singleton *)userData; 126 *sp->hdr = *h; 127 sp->pkt = pkt; 128} 129 130const u_char * 131pcap_next(pcap_t *p, struct pcap_pkthdr *h) 132{ 133 struct singleton s; 134 135 s.hdr = h; 136 if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0) 137 return (0); 138 return (s.pkt); 139} 140 141struct pkt_for_fakecallback { 142 struct pcap_pkthdr *hdr; 143 const u_char **pkt; 144}; 145 146static void 147pcap_fakecallback(u_char *userData, const struct pcap_pkthdr *h, 148 const u_char *pkt) 149{ 150 struct pkt_for_fakecallback *sp = (struct pkt_for_fakecallback *)userData; 151 152 *sp->hdr = *h; 153 *sp->pkt = pkt; 154} 155 156int 157pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header, 158 const u_char **pkt_data) 159{ 160 struct pkt_for_fakecallback s; 161 162 s.hdr = &p->pcap_header; 163 s.pkt = pkt_data; 164 165 /* Saves a pointer to the packet headers */ 166 *pkt_header= &p->pcap_header; 167 168 if (p->sf.rfile != NULL) { 169 int status; 170 171 /* We are on an offline capture */ 172 status = pcap_offline_read(p, 1, pcap_fakecallback, 173 (u_char *)&s); 174 175 /* 176 * Return codes for pcap_offline_read() are: 177 * - 0: EOF 178 * - -1: error 179 * - >1: OK 180 * The first one ('0') conflicts with the return code of 181 * 0 from pcap_read() meaning "no packets arrived before 182 * the timeout expired", so we map it to -2 so you can 183 * distinguish between an EOF from a savefile and a 184 * "no packets arrived before the timeout expired, try 185 * again" from a live capture. 186 */ 187 if (status == 0) 188 return (-2); 189 else 190 return (status); 191 } 192 193 /* 194 * Return codes for pcap_read() are: 195 * - 0: timeout 196 * - -1: error 197 * - -2: loop was broken out of with pcap_breakloop() 198 * - >1: OK 199 * The first one ('0') conflicts with the return code of 0 from 200 * pcap_offline_read() meaning "end of file". 201 */ 202 return (p->read_op(p, 1, pcap_fakecallback, (u_char *)&s)); 203} 204 205/* 206 * Force the loop in "pcap_read()" or "pcap_read_offline()" to terminate. 207 */ 208void 209pcap_breakloop(pcap_t *p) 210{ 211 p->break_loop = 1; 212} 213 214int 215pcap_datalink(pcap_t *p) 216{ 217 return (p->linktype); 218} 219 220int 221pcap_list_datalinks(pcap_t *p, int **dlt_buffer) 222{ 223 if (p->dlt_count == 0) { 224 /* 225 * We couldn't fetch the list of DLTs, which means 226 * this platform doesn't support changing the 227 * DLT for an interface. Return a list of DLTs 228 * containing only the DLT this device supports. 229 */ 230 *dlt_buffer = (int*)malloc(sizeof(**dlt_buffer)); 231 if (*dlt_buffer == NULL) { 232 (void)snprintf(p->errbuf, sizeof(p->errbuf), 233 "malloc: %s", pcap_strerror(errno)); 234 return (-1); 235 } 236 **dlt_buffer = p->linktype; 237 return (1); 238 } else { 239 *dlt_buffer = (int*)malloc(sizeof(**dlt_buffer) * p->dlt_count); 240 if (*dlt_buffer == NULL) { 241 (void)snprintf(p->errbuf, sizeof(p->errbuf), 242 "malloc: %s", pcap_strerror(errno)); 243 return (-1); 244 } 245 (void)memcpy(*dlt_buffer, p->dlt_list, 246 sizeof(**dlt_buffer) * p->dlt_count); 247 return (p->dlt_count); 248 } 249} 250 251int 252pcap_set_datalink(pcap_t *p, int dlt) 253{ 254 int i; 255 const char *dlt_name; 256 257 if (p->dlt_count == 0 || p->set_datalink_op == NULL) { 258 /* 259 * We couldn't fetch the list of DLTs, or we don't 260 * have a "set datalink" operation, which means 261 * this platform doesn't support changing the 262 * DLT for an interface. Check whether the new 263 * DLT is the one this interface supports. 264 */ 265 if (p->linktype != dlt) 266 goto unsupported; 267 268 /* 269 * It is, so there's nothing we need to do here. 270 */ 271 return (0); 272 } 273 for (i = 0; i < p->dlt_count; i++) 274 if (p->dlt_list[i] == dlt) 275 break; 276 if (i >= p->dlt_count) 277 goto unsupported; 278 if (p->set_datalink_op(p, dlt) == -1) 279 return (-1); 280 p->linktype = dlt; 281 return (0); 282 283unsupported: 284 dlt_name = pcap_datalink_val_to_name(dlt); 285 if (dlt_name != NULL) { 286 (void) snprintf(p->errbuf, sizeof(p->errbuf), 287 "%s is not one of the DLTs supported by this device", 288 dlt_name); 289 } else { 290 (void) snprintf(p->errbuf, sizeof(p->errbuf), 291 "DLT %d is not one of the DLTs supported by this device", 292 dlt); 293 } 294 return (-1); 295} 296 297struct dlt_choice { 298 const char *name; 299 const char *description; 300 int dlt; 301}; 302 303#define DLT_CHOICE(code, description) { #code, description, code } 304#define DLT_CHOICE_SENTINEL { NULL, NULL, 0 } 305 306static struct dlt_choice dlt_choices[] = { 307 DLT_CHOICE(DLT_NULL, "BSD loopback"), 308 DLT_CHOICE(DLT_EN10MB, "Ethernet"), 309 DLT_CHOICE(DLT_IEEE802, "Token ring"), 310 DLT_CHOICE(DLT_ARCNET, "ARCNET"), 311 DLT_CHOICE(DLT_SLIP, "SLIP"), 312 DLT_CHOICE(DLT_PPP, "PPP"), 313 DLT_CHOICE(DLT_FDDI, "FDDI"), 314 DLT_CHOICE(DLT_ATM_RFC1483, "RFC 1483 IP-over-ATM"), 315 DLT_CHOICE(DLT_RAW, "Raw IP"), 316 DLT_CHOICE(DLT_SLIP_BSDOS, "BSD/OS SLIP"), 317 DLT_CHOICE(DLT_PPP_BSDOS, "BSD/OS PPP"), 318 DLT_CHOICE(DLT_ATM_CLIP, "Linux Classical IP-over-ATM"), 319 DLT_CHOICE(DLT_PPP_SERIAL, "PPP over serial"), 320 DLT_CHOICE(DLT_PPP_ETHER, "PPPoE"), 321 DLT_CHOICE(DLT_C_HDLC, "Cisco HDLC"), 322 DLT_CHOICE(DLT_IEEE802_11, "802.11"), 323 DLT_CHOICE(DLT_FRELAY, "Frame Relay"), 324 DLT_CHOICE(DLT_LOOP, "OpenBSD loopback"), 325 DLT_CHOICE(DLT_ENC, "OpenBSD encapsulated IP"), 326 DLT_CHOICE(DLT_LINUX_SLL, "Linux cooked"), 327 DLT_CHOICE(DLT_LTALK, "Localtalk"), 328 DLT_CHOICE(DLT_PFLOG, "OpenBSD pflog file"), 329 DLT_CHOICE(DLT_PRISM_HEADER, "802.11 plus Prism header"), 330 DLT_CHOICE(DLT_IP_OVER_FC, "RFC 2625 IP-over-Fibre Channel"), 331 DLT_CHOICE(DLT_SUNATM, "Sun raw ATM"), 332 DLT_CHOICE(DLT_IEEE802_11_RADIO, "802.11 plus BSD radio information header"), 333 DLT_CHOICE(DLT_APPLE_IP_OVER_IEEE1394, "Apple IP-over-IEEE 1394"), 334 DLT_CHOICE(DLT_ARCNET_LINUX, "Linux ARCNET"), 335 DLT_CHOICE(DLT_LINUX_IRDA, "Linux IrDA"), 336 DLT_CHOICE(DLT_IEEE802_11_RADIO_AVS, "802.11 plus AVS radio information header"), 337 DLT_CHOICE_SENTINEL 338}; 339 340/* 341 * This array is designed for mapping upper and lower case letter 342 * together for a case independent comparison. The mappings are 343 * based upon ascii character sequences. 344 */ 345static const u_char charmap[] = { 346 (u_char)'\000', (u_char)'\001', (u_char)'\002', (u_char)'\003', 347 (u_char)'\004', (u_char)'\005', (u_char)'\006', (u_char)'\007', 348 (u_char)'\010', (u_char)'\011', (u_char)'\012', (u_char)'\013', 349 (u_char)'\014', (u_char)'\015', (u_char)'\016', (u_char)'\017', 350 (u_char)'\020', (u_char)'\021', (u_char)'\022', (u_char)'\023', 351 (u_char)'\024', (u_char)'\025', (u_char)'\026', (u_char)'\027', 352 (u_char)'\030', (u_char)'\031', (u_char)'\032', (u_char)'\033', 353 (u_char)'\034', (u_char)'\035', (u_char)'\036', (u_char)'\037', 354 (u_char)'\040', (u_char)'\041', (u_char)'\042', (u_char)'\043', 355 (u_char)'\044', (u_char)'\045', (u_char)'\046', (u_char)'\047', 356 (u_char)'\050', (u_char)'\051', (u_char)'\052', (u_char)'\053', 357 (u_char)'\054', (u_char)'\055', (u_char)'\056', (u_char)'\057', 358 (u_char)'\060', (u_char)'\061', (u_char)'\062', (u_char)'\063', 359 (u_char)'\064', (u_char)'\065', (u_char)'\066', (u_char)'\067', 360 (u_char)'\070', (u_char)'\071', (u_char)'\072', (u_char)'\073', 361 (u_char)'\074', (u_char)'\075', (u_char)'\076', (u_char)'\077', 362 (u_char)'\100', (u_char)'\141', (u_char)'\142', (u_char)'\143', 363 (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147', 364 (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153', 365 (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157', 366 (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163', 367 (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167', 368 (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\133', 369 (u_char)'\134', (u_char)'\135', (u_char)'\136', (u_char)'\137', 370 (u_char)'\140', (u_char)'\141', (u_char)'\142', (u_char)'\143', 371 (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147', 372 (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153', 373 (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157', 374 (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163', 375 (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167', 376 (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\173', 377 (u_char)'\174', (u_char)'\175', (u_char)'\176', (u_char)'\177', 378 (u_char)'\200', (u_char)'\201', (u_char)'\202', (u_char)'\203', 379 (u_char)'\204', (u_char)'\205', (u_char)'\206', (u_char)'\207', 380 (u_char)'\210', (u_char)'\211', (u_char)'\212', (u_char)'\213', 381 (u_char)'\214', (u_char)'\215', (u_char)'\216', (u_char)'\217', 382 (u_char)'\220', (u_char)'\221', (u_char)'\222', (u_char)'\223', 383 (u_char)'\224', (u_char)'\225', (u_char)'\226', (u_char)'\227', 384 (u_char)'\230', (u_char)'\231', (u_char)'\232', (u_char)'\233', 385 (u_char)'\234', (u_char)'\235', (u_char)'\236', (u_char)'\237', 386 (u_char)'\240', (u_char)'\241', (u_char)'\242', (u_char)'\243', 387 (u_char)'\244', (u_char)'\245', (u_char)'\246', (u_char)'\247', 388 (u_char)'\250', (u_char)'\251', (u_char)'\252', (u_char)'\253', 389 (u_char)'\254', (u_char)'\255', (u_char)'\256', (u_char)'\257', 390 (u_char)'\260', (u_char)'\261', (u_char)'\262', (u_char)'\263', 391 (u_char)'\264', (u_char)'\265', (u_char)'\266', (u_char)'\267', 392 (u_char)'\270', (u_char)'\271', (u_char)'\272', (u_char)'\273', 393 (u_char)'\274', (u_char)'\275', (u_char)'\276', (u_char)'\277', 394 (u_char)'\300', (u_char)'\341', (u_char)'\342', (u_char)'\343', 395 (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347', 396 (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353', 397 (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357', 398 (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363', 399 (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367', 400 (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\333', 401 (u_char)'\334', (u_char)'\335', (u_char)'\336', (u_char)'\337', 402 (u_char)'\340', (u_char)'\341', (u_char)'\342', (u_char)'\343', 403 (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347', 404 (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353', 405 (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357', 406 (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363', 407 (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367', 408 (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\373', 409 (u_char)'\374', (u_char)'\375', (u_char)'\376', (u_char)'\377', 410}; 411 412int 413pcap_strcasecmp(const char *s1, const char *s2) 414{ 415 register const u_char *cm = charmap, 416 *us1 = (u_char *)s1, 417 *us2 = (u_char *)s2; 418 419 while (cm[*us1] == cm[*us2++]) 420 if (*us1++ == '\0') 421 return(0); 422 return (cm[*us1] - cm[*--us2]); 423} 424 425int 426pcap_datalink_name_to_val(const char *name) 427{ 428 int i; 429 430 for (i = 0; dlt_choices[i].name != NULL; i++) { 431 if (pcap_strcasecmp(dlt_choices[i].name + sizeof("DLT_") - 1, 432 name) == 0) 433 return (dlt_choices[i].dlt); 434 } 435 return (-1); 436} 437 438const char * 439pcap_datalink_val_to_name(int dlt) 440{ 441 int i; 442 443 for (i = 0; dlt_choices[i].name != NULL; i++) { 444 if (dlt_choices[i].dlt == dlt) 445 return (dlt_choices[i].name + sizeof("DLT_") - 1); 446 } 447 return (NULL); 448} 449 450const char * 451pcap_datalink_val_to_description(int dlt) 452{ 453 int i; 454 455 for (i = 0; dlt_choices[i].name != NULL; i++) { 456 if (dlt_choices[i].dlt == dlt) 457 return (dlt_choices[i].description); 458 } 459 return (NULL); 460} 461 462int 463pcap_snapshot(pcap_t *p) 464{ 465 return (p->snapshot); 466} 467 468int 469pcap_is_swapped(pcap_t *p) 470{ 471 return (p->sf.swapped); 472} 473 474int 475pcap_major_version(pcap_t *p) 476{ 477 return (p->sf.version_major); 478} 479 480int 481pcap_minor_version(pcap_t *p) 482{ 483 return (p->sf.version_minor); 484} 485 486FILE * 487pcap_file(pcap_t *p) 488{ 489 return (p->sf.rfile); 490} 491 492int 493pcap_fileno(pcap_t *p) 494{ 495#ifndef WIN32 496 return (p->fd); 497#else 498 if (p->adapter != NULL) 499 return ((int)(DWORD)p->adapter->hFile); 500 else 501 return (-1); 502#endif 503} 504 505#ifndef WIN32 506int 507pcap_get_selectable_fd(pcap_t *p) 508{ 509 return (p->selectable_fd); 510} 511#endif 512 513void 514pcap_perror(pcap_t *p, char *prefix) 515{ 516 fprintf(stderr, "%s: %s\n", prefix, p->errbuf); 517} 518 519char * 520pcap_geterr(pcap_t *p) 521{ 522 return (p->errbuf); 523} 524 525int 526pcap_getnonblock(pcap_t *p, char *errbuf) 527{ 528 return p->getnonblock_op(p, errbuf); 529} 530 531/* 532 * Get the current non-blocking mode setting, under the assumption that 533 * it's just the standard POSIX non-blocking flag. 534 * 535 * We don't look at "p->nonblock", in case somebody tweaked the FD 536 * directly. 537 */ 538#ifndef WIN32 539int 540pcap_getnonblock_fd(pcap_t *p, char *errbuf) 541{ 542 int fdflags; 543 544 fdflags = fcntl(p->fd, F_GETFL, 0); 545 if (fdflags == -1) { 546 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s", 547 pcap_strerror(errno)); 548 return (-1); 549 } 550 if (fdflags & O_NONBLOCK) 551 return (1); 552 else 553 return (0); 554} 555#endif 556 557int 558pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf) 559{ 560 return p->setnonblock_op(p, nonblock, errbuf); 561} 562 563#ifndef WIN32 564/* 565 * Set non-blocking mode, under the assumption that it's just the 566 * standard POSIX non-blocking flag. (This can be called by the 567 * per-platform non-blocking-mode routine if that routine also 568 * needs to do some additional work.) 569 */ 570int 571pcap_setnonblock_fd(pcap_t *p, int nonblock, char *errbuf) 572{ 573 int fdflags; 574 575 fdflags = fcntl(p->fd, F_GETFL, 0); 576 if (fdflags == -1) { 577 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s", 578 pcap_strerror(errno)); 579 return (-1); 580 } 581 if (nonblock) 582 fdflags |= O_NONBLOCK; 583 else 584 fdflags &= ~O_NONBLOCK; 585 if (fcntl(p->fd, F_SETFL, fdflags) == -1) { 586 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s", 587 pcap_strerror(errno)); 588 return (-1); 589 } 590 return (0); 591} 592#endif 593 594#ifdef WIN32 595/* 596 * Generate a string for the last Win32-specific error (i.e. an error generated when 597 * calling a Win32 API). 598 * For errors occurred during standard C calls, we still use pcap_strerror() 599 */ 600char * 601pcap_win32strerror(void) 602{ 603 DWORD error; 604 static char errbuf[PCAP_ERRBUF_SIZE+1]; 605 int errlen; 606 607 error = GetLastError(); 608 FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf, 609 PCAP_ERRBUF_SIZE, NULL); 610 611 /* 612 * "FormatMessage()" "helpfully" sticks CR/LF at the end of the 613 * message. Get rid of it. 614 */ 615 errlen = strlen(errbuf); 616 if (errlen >= 2) { 617 errbuf[errlen - 1] = '\0'; 618 errbuf[errlen - 2] = '\0'; 619 } 620 return (errbuf); 621} 622#endif 623 624/* 625 * Not all systems have strerror(). 626 */ 627char * 628pcap_strerror(int errnum) 629{ 630#ifdef HAVE_STRERROR 631 return (strerror(errnum)); 632#else 633 extern int sys_nerr; 634 extern const char *const sys_errlist[]; 635 static char ebuf[20]; 636 637 if ((unsigned int)errnum < sys_nerr) 638 return ((char *)sys_errlist[errnum]); 639 (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum); 640 return(ebuf); 641#endif 642} 643 644int 645pcap_setfilter(pcap_t *p, struct bpf_program *fp) 646{ 647 return p->setfilter_op(p, fp); 648} 649 650int 651pcap_stats(pcap_t *p, struct pcap_stat *ps) 652{ 653 return p->stats_op(p, ps); 654} 655 656static int 657pcap_stats_dead(pcap_t *p, struct pcap_stat *ps) 658{ 659 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 660 "Statistics aren't available from a pcap_open_dead pcap_t"); 661 return (-1); 662} 663 664static void 665pcap_close_dead(pcap_t *p) 666{ 667 /* Nothing to do. */ 668} 669 670pcap_t * 671pcap_open_dead(int linktype, int snaplen) 672{ 673 pcap_t *p; 674 675 p = malloc(sizeof(*p)); 676 if (p == NULL) 677 return NULL; 678 memset (p, 0, sizeof(*p)); 679 p->snapshot = snaplen; 680 p->linktype = linktype; 681 p->stats_op = pcap_stats_dead; 682 p->close_op = pcap_close_dead; 683 return p; 684} 685 686void 687pcap_close(pcap_t *p) 688{ 689 p->close_op(p); 690 if (p->dlt_list != NULL) 691 free(p->dlt_list); 692 pcap_freecode(&p->fcode); 693 free(p); 694} 695 696/* 697 * We make the version string static, and return a pointer to it, rather 698 * than exporting the version string directly. On at least some UNIXes, 699 * if you import data from a shared library into an program, the data is 700 * bound into the program binary, so if the string in the version of the 701 * library with which the program was linked isn't the same as the 702 * string in the version of the library with which the program is being 703 * run, various undesirable things may happen (warnings, the string 704 * being the one from the version of the library with which the program 705 * was linked, or even weirder things, such as the string being the one 706 * from the library but being truncated). 707 */ 708#ifdef WIN32 709/* 710 * XXX - it'd be nice if we could somehow generate the WinPcap and libpcap 711 * version numbers when building WinPcap. (It'd be nice to do so for 712 * the packet.dll version number as well.) 713 */ 714static const char wpcap_version_string[] = "3.0"; 715static const char pcap_version_string_fmt[] = 716 "WinPcap version %s, based on libpcap version 0.8"; 717static const char pcap_version_string_packet_dll_fmt[] = 718 "WinPcap version %s (packet.dll version %s), based on libpcap version 0.8"; 719static char *pcap_version_string; 720 721const char * 722pcap_lib_version(void) 723{ 724 char *packet_version_string; 725 size_t pcap_version_string_len; 726 727 if (pcap_version_string == NULL) { 728 /* 729 * Generate the version string. 730 */ 731 packet_version_string = PacketGetVersion(); 732 if (strcmp(wpcap_version_string, packet_version_string) == 0) { 733 /* 734 * WinPcap version string and packet.dll version 735 * string are the same; just report the WinPcap 736 * version. 737 */ 738 pcap_version_string_len = 739 (sizeof pcap_version_string_fmt - 2) + 740 strlen(wpcap_version_string); 741 pcap_version_string = malloc(pcap_version_string_len); 742 sprintf(pcap_version_string, pcap_version_string_fmt, 743 wpcap_version_string); 744 } else { 745 /* 746 * WinPcap version string and packet.dll version 747 * string are different; that shouldn't be the 748 * case (the two libraries should come from the 749 * same version of WinPcap), so we report both 750 * versions. 751 */ 752 pcap_version_string_len = 753 (sizeof pcap_version_string_packet_dll_fmt - 4) + 754 strlen(wpcap_version_string) + 755 strlen(packet_version_string); 756 pcap_version_string = malloc(pcap_version_string_len); 757 sprintf(pcap_version_string, 758 pcap_version_string_packet_dll_fmt, 759 wpcap_version_string, packet_version_string); 760 } 761 } 762 return (pcap_version_string); 763} 764#else 765#include "version.h" 766 767const char * 768pcap_lib_version(void) 769{ 770 return (pcap_version_string); 771} 772#endif 773