1 /* 2 * Copyright (c) 1993, 1994, 1995, 1996, 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: (1) source code distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 */ 21 #ifndef lint 22 static const char rcsid[] _U_ = 23 "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.116 2008-09-16 18:42:29 guy Exp $ (LBL)"; 24 #endif 25 26 #ifdef HAVE_CONFIG_H 27 #include "config.h" 28 #endif 29 30 #include <sys/param.h> /* optionally get BSD define */ 31 #ifdef HAVE_ZEROCOPY_BPF 32 #include <sys/mman.h> 33 #endif 34 #include <sys/socket.h> 35 #include <time.h> 36 /* 37 * <net/bpf.h> defines ioctls, but doesn't include <sys/ioccom.h>. 38 * 39 * We include <sys/ioctl.h> as it might be necessary to declare ioctl(); 40 * at least on *BSD and Mac OS X, it also defines various SIOC ioctls - 41 * we could include <sys/sockio.h>, but if we're already including 42 * <sys/ioctl.h>, which includes <sys/sockio.h> on those platforms, 43 * there's not much point in doing so. 44 * 45 * If we have <sys/ioccom.h>, we include it as well, to handle systems 46 * such as Solaris which don't arrange to include <sys/ioccom.h> if you 47 * include <sys/ioctl.h> 48 */ 49 #include <sys/ioctl.h> 50 #ifdef HAVE_SYS_IOCCOM_H 51 #include <sys/ioccom.h> 52 #endif 53 #include <sys/utsname.h> 54 55 #ifdef HAVE_ZEROCOPY_BPF 56 #include <machine/atomic.h> 57 #endif 58 59 #include <net/if.h> 60 61 #ifdef _AIX 62 63 /* 64 * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the 65 * native OS version, as we need "struct bpf_config" from it. 66 */ 67 #define PCAP_DONT_INCLUDE_PCAP_BPF_H 68 69 #include <sys/types.h> 70 71 /* 72 * Prevent bpf.h from redefining the DLT_ values to their 73 * IFT_ values, as we're going to return the standard libpcap 74 * values, not IBM's non-standard IFT_ values. 75 */ 76 #undef _AIX 77 #include <net/bpf.h> 78 #define _AIX 79 80 #include <net/if_types.h> /* for IFT_ values */ 81 #include <sys/sysconfig.h> 82 #include <sys/device.h> 83 #include <sys/cfgodm.h> 84 #include <cf.h> 85 86 #ifdef __64BIT__ 87 #define domakedev makedev64 88 #define getmajor major64 89 #define bpf_hdr bpf_hdr32 90 #else /* __64BIT__ */ 91 #define domakedev makedev 92 #define getmajor major 93 #endif /* __64BIT__ */ 94 95 #define BPF_NAME "bpf" 96 #define BPF_MINORS 4 97 #define DRIVER_PATH "/usr/lib/drivers" 98 #define BPF_NODE "/dev/bpf" 99 static int bpfloadedflag = 0; 100 static int odmlockid = 0; 101 102 static int bpf_load(char *errbuf); 103 104 #else /* _AIX */ 105 106 #include <net/bpf.h> 107 108 #endif /* _AIX */ 109 110 #include <ctype.h> 111 #include <fcntl.h> 112 #include <errno.h> 113 #include <netdb.h> 114 #include <stdio.h> 115 #include <stdlib.h> 116 #include <string.h> 117 #include <unistd.h> 118 119 #ifdef HAVE_NET_IF_MEDIA_H 120 # include <net/if_media.h> 121 #endif 122 123 #include "pcap-int.h" 124 125 #ifdef HAVE_DAG_API 126 #include "pcap-dag.h" 127 #endif /* HAVE_DAG_API */ 128 129 #ifdef HAVE_SNF_API 130 #include "pcap-snf.h" 131 #endif /* HAVE_SNF_API */ 132 133 #ifdef HAVE_OS_PROTO_H 134 #include "os-proto.h" 135 #endif 136 137 #ifdef BIOCGDLTLIST 138 # if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__) 139 #define HAVE_BSD_IEEE80211 140 # endif 141 142 # if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 143 static int find_802_11(struct bpf_dltlist *); 144 145 # ifdef HAVE_BSD_IEEE80211 146 static int monitor_mode(pcap_t *, int); 147 # endif 148 149 # if defined(__APPLE__) 150 static void remove_en(pcap_t *); 151 static void remove_802_11(pcap_t *); 152 # endif 153 154 # endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */ 155 156 #endif /* BIOCGDLTLIST */ 157 158 #if defined(sun) && defined(LIFNAMSIZ) && defined(lifr_zoneid) 159 #include <zone.h> 160 #endif 161 162 /* 163 * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably 164 * don't get DLT_DOCSIS defined. 165 */ 166 #ifndef DLT_DOCSIS 167 #define DLT_DOCSIS 143 168 #endif 169 170 /* 171 * On OS X, we don't even get any of the 802.11-plus-radio-header DLT_'s 172 * defined, even though some of them are used by various Airport drivers. 173 */ 174 #ifndef DLT_PRISM_HEADER 175 #define DLT_PRISM_HEADER 119 176 #endif 177 #ifndef DLT_AIRONET_HEADER 178 #define DLT_AIRONET_HEADER 120 179 #endif 180 #ifndef DLT_IEEE802_11_RADIO 181 #define DLT_IEEE802_11_RADIO 127 182 #endif 183 #ifndef DLT_IEEE802_11_RADIO_AVS 184 #define DLT_IEEE802_11_RADIO_AVS 163 185 #endif 186 187 static int pcap_can_set_rfmon_bpf(pcap_t *p); 188 static int pcap_activate_bpf(pcap_t *p); 189 static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp); 190 static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t); 191 static int pcap_set_datalink_bpf(pcap_t *p, int dlt); 192 193 /* 194 * For zerocopy bpf, the setnonblock/getnonblock routines need to modify 195 * p->md.timeout so we don't call select(2) if the pcap handle is in non- 196 * blocking mode. We preserve the timeout supplied by pcap_open functions 197 * to make sure it does not get clobbered if the pcap handle moves between 198 * blocking and non-blocking mode. 199 */ 200 static int 201 pcap_getnonblock_bpf(pcap_t *p, char *errbuf) 202 { 203 #ifdef HAVE_ZEROCOPY_BPF 204 if (p->md.zerocopy) { 205 /* 206 * Use a negative value for the timeout to represent that the 207 * pcap handle is in non-blocking mode. 208 */ 209 return (p->md.timeout < 0); 210 } 211 #endif 212 return (pcap_getnonblock_fd(p, errbuf)); 213 } 214 215 static int 216 pcap_setnonblock_bpf(pcap_t *p, int nonblock, char *errbuf) 217 { 218 #ifdef HAVE_ZEROCOPY_BPF 219 if (p->md.zerocopy) { 220 /* 221 * Map each value to the corresponding 2's complement, to 222 * preserve the timeout value provided with pcap_set_timeout. 223 * (from pcap-linux.c). 224 */ 225 if (nonblock) { 226 if (p->md.timeout >= 0) { 227 /* 228 * Timeout is non-negative, so we're not 229 * currently in non-blocking mode; set it 230 * to the 2's complement, to make it 231 * negative, as an indication that we're 232 * in non-blocking mode. 233 */ 234 p->md.timeout = p->md.timeout * -1 - 1; 235 } 236 } else { 237 if (p->md.timeout < 0) { 238 /* 239 * Timeout is negative, so we're currently 240 * in blocking mode; reverse the previous 241 * operation, to make the timeout non-negative 242 * again. 243 */ 244 p->md.timeout = (p->md.timeout + 1) * -1; 245 } 246 } 247 return (0); 248 } 249 #endif 250 return (pcap_setnonblock_fd(p, nonblock, errbuf)); 251 } 252 253 #ifdef HAVE_ZEROCOPY_BPF 254 /* 255 * Zero-copy BPF buffer routines to check for and acknowledge BPF data in 256 * shared memory buffers. 257 * 258 * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer, 259 * and set up p->buffer and cc to reflect one if available. Notice that if 260 * there was no prior buffer, we select zbuf1 as this will be the first 261 * buffer filled for a fresh BPF session. 262 */ 263 static int 264 pcap_next_zbuf_shm(pcap_t *p, int *cc) 265 { 266 struct bpf_zbuf_header *bzh; 267 268 if (p->md.zbuffer == p->md.zbuf2 || p->md.zbuffer == NULL) { 269 bzh = (struct bpf_zbuf_header *)p->md.zbuf1; 270 if (bzh->bzh_user_gen != 271 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 272 p->md.bzh = bzh; 273 p->md.zbuffer = (u_char *)p->md.zbuf1; 274 p->buffer = p->md.zbuffer + sizeof(*bzh); 275 *cc = bzh->bzh_kernel_len; 276 return (1); 277 } 278 } else if (p->md.zbuffer == p->md.zbuf1) { 279 bzh = (struct bpf_zbuf_header *)p->md.zbuf2; 280 if (bzh->bzh_user_gen != 281 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 282 p->md.bzh = bzh; 283 p->md.zbuffer = (u_char *)p->md.zbuf2; 284 p->buffer = p->md.zbuffer + sizeof(*bzh); 285 *cc = bzh->bzh_kernel_len; 286 return (1); 287 } 288 } 289 *cc = 0; 290 return (0); 291 } 292 293 /* 294 * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using 295 * select() for data or a timeout, and possibly force rotation of the buffer 296 * in the event we time out or are in immediate mode. Invoke the shared 297 * memory check before doing system calls in order to avoid doing avoidable 298 * work. 299 */ 300 static int 301 pcap_next_zbuf(pcap_t *p, int *cc) 302 { 303 struct bpf_zbuf bz; 304 struct timeval tv; 305 struct timespec cur; 306 fd_set r_set; 307 int data, r; 308 int expire, tmout; 309 310 #define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000)) 311 /* 312 * Start out by seeing whether anything is waiting by checking the 313 * next shared memory buffer for data. 314 */ 315 data = pcap_next_zbuf_shm(p, cc); 316 if (data) 317 return (data); 318 /* 319 * If a previous sleep was interrupted due to signal delivery, make 320 * sure that the timeout gets adjusted accordingly. This requires 321 * that we analyze when the timeout should be been expired, and 322 * subtract the current time from that. If after this operation, 323 * our timeout is less then or equal to zero, handle it like a 324 * regular timeout. 325 */ 326 tmout = p->md.timeout; 327 if (tmout) 328 (void) clock_gettime(CLOCK_MONOTONIC, &cur); 329 if (p->md.interrupted && p->md.timeout) { 330 expire = TSTOMILLI(&p->md.firstsel) + p->md.timeout; 331 tmout = expire - TSTOMILLI(&cur); 332 #undef TSTOMILLI 333 if (tmout <= 0) { 334 p->md.interrupted = 0; 335 data = pcap_next_zbuf_shm(p, cc); 336 if (data) 337 return (data); 338 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 339 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 340 "BIOCROTZBUF: %s", strerror(errno)); 341 return (PCAP_ERROR); 342 } 343 return (pcap_next_zbuf_shm(p, cc)); 344 } 345 } 346 /* 347 * No data in the buffer, so must use select() to wait for data or 348 * the next timeout. Note that we only call select if the handle 349 * is in blocking mode. 350 */ 351 if (p->md.timeout >= 0) { 352 FD_ZERO(&r_set); 353 FD_SET(p->fd, &r_set); 354 if (tmout != 0) { 355 tv.tv_sec = tmout / 1000; 356 tv.tv_usec = (tmout * 1000) % 1000000; 357 } 358 r = select(p->fd + 1, &r_set, NULL, NULL, 359 p->md.timeout != 0 ? &tv : NULL); 360 if (r < 0 && errno == EINTR) { 361 if (!p->md.interrupted && p->md.timeout) { 362 p->md.interrupted = 1; 363 p->md.firstsel = cur; 364 } 365 return (0); 366 } else if (r < 0) { 367 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 368 "select: %s", strerror(errno)); 369 return (PCAP_ERROR); 370 } 371 } 372 p->md.interrupted = 0; 373 /* 374 * Check again for data, which may exist now that we've either been 375 * woken up as a result of data or timed out. Try the "there's data" 376 * case first since it doesn't require a system call. 377 */ 378 data = pcap_next_zbuf_shm(p, cc); 379 if (data) 380 return (data); 381 /* 382 * Try forcing a buffer rotation to dislodge timed out or immediate 383 * data. 384 */ 385 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 386 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 387 "BIOCROTZBUF: %s", strerror(errno)); 388 return (PCAP_ERROR); 389 } 390 return (pcap_next_zbuf_shm(p, cc)); 391 } 392 393 /* 394 * Notify kernel that we are done with the buffer. We don't reset zbuffer so 395 * that we know which buffer to use next time around. 396 */ 397 static int 398 pcap_ack_zbuf(pcap_t *p) 399 { 400 401 atomic_store_rel_int(&p->md.bzh->bzh_user_gen, 402 p->md.bzh->bzh_kernel_gen); 403 p->md.bzh = NULL; 404 p->buffer = NULL; 405 return (0); 406 } 407 #endif /* HAVE_ZEROCOPY_BPF */ 408 409 pcap_t * 410 pcap_create(const char *device, char *ebuf) 411 { 412 pcap_t *p; 413 414 #ifdef HAVE_DAG_API 415 if (strstr(device, "dag")) 416 return (dag_create(device, ebuf)); 417 #endif /* HAVE_DAG_API */ 418 #ifdef HAVE_SNF_API 419 if (strstr(device, "snf")) 420 return (snf_create(device, ebuf)); 421 #endif /* HAVE_SNF_API */ 422 423 p = pcap_create_common(device, ebuf); 424 if (p == NULL) 425 return (NULL); 426 427 p->activate_op = pcap_activate_bpf; 428 p->can_set_rfmon_op = pcap_can_set_rfmon_bpf; 429 return (p); 430 } 431 432 /* 433 * On success, returns a file descriptor for a BPF device. 434 * On failure, returns a PCAP_ERROR_ value, and sets p->errbuf. 435 */ 436 static int 437 bpf_open(pcap_t *p) 438 { 439 int fd; 440 #ifdef HAVE_CLONING_BPF 441 static const char device[] = "/dev/bpf"; 442 #else 443 int n = 0; 444 char device[sizeof "/dev/bpf0000000000"]; 445 #endif 446 447 #ifdef _AIX 448 /* 449 * Load the bpf driver, if it isn't already loaded, 450 * and create the BPF device entries, if they don't 451 * already exist. 452 */ 453 if (bpf_load(p->errbuf) == PCAP_ERROR) 454 return (PCAP_ERROR); 455 #endif 456 457 #ifdef HAVE_CLONING_BPF 458 if ((fd = open(device, O_RDWR)) == -1 && 459 (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) { 460 if (errno == EACCES) 461 fd = PCAP_ERROR_PERM_DENIED; 462 else 463 fd = PCAP_ERROR; 464 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 465 "(cannot open device) %s: %s", device, pcap_strerror(errno)); 466 } 467 #else 468 /* 469 * Go through all the minors and find one that isn't in use. 470 */ 471 do { 472 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); 473 /* 474 * Initially try a read/write open (to allow the inject 475 * method to work). If that fails due to permission 476 * issues, fall back to read-only. This allows a 477 * non-root user to be granted specific access to pcap 478 * capabilities via file permissions. 479 * 480 * XXX - we should have an API that has a flag that 481 * controls whether to open read-only or read-write, 482 * so that denial of permission to send (or inability 483 * to send, if sending packets isn't supported on 484 * the device in question) can be indicated at open 485 * time. 486 */ 487 fd = open(device, O_RDWR); 488 if (fd == -1 && errno == EACCES) 489 fd = open(device, O_RDONLY); 490 } while (fd < 0 && errno == EBUSY); 491 492 /* 493 * XXX better message for all minors used 494 */ 495 if (fd < 0) { 496 switch (errno) { 497 498 case ENOENT: 499 fd = PCAP_ERROR; 500 if (n == 1) { 501 /* 502 * /dev/bpf0 doesn't exist, which 503 * means we probably have no BPF 504 * devices. 505 */ 506 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 507 "(there are no BPF devices)"); 508 } else { 509 /* 510 * We got EBUSY on at least one 511 * BPF device, so we have BPF 512 * devices, but all the ones 513 * that exist are busy. 514 */ 515 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 516 "(all BPF devices are busy)"); 517 } 518 break; 519 520 case EACCES: 521 /* 522 * Got EACCES on the last device we tried, 523 * and EBUSY on all devices before that, 524 * if any. 525 */ 526 fd = PCAP_ERROR_PERM_DENIED; 527 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 528 "(cannot open BPF device) %s: %s", device, 529 pcap_strerror(errno)); 530 break; 531 532 default: 533 /* 534 * Some other problem. 535 */ 536 fd = PCAP_ERROR; 537 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 538 "(cannot open BPF device) %s: %s", device, 539 pcap_strerror(errno)); 540 break; 541 } 542 } 543 #endif 544 545 return (fd); 546 } 547 548 #ifdef BIOCGDLTLIST 549 static int 550 get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf) 551 { 552 memset(bdlp, 0, sizeof(*bdlp)); 553 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) { 554 u_int i; 555 int is_ethernet; 556 557 bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1)); 558 if (bdlp->bfl_list == NULL) { 559 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", 560 pcap_strerror(errno)); 561 return (PCAP_ERROR); 562 } 563 564 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) { 565 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, 566 "BIOCGDLTLIST: %s", pcap_strerror(errno)); 567 free(bdlp->bfl_list); 568 return (PCAP_ERROR); 569 } 570 571 /* 572 * OK, for real Ethernet devices, add DLT_DOCSIS to the 573 * list, so that an application can let you choose it, 574 * in case you're capturing DOCSIS traffic that a Cisco 575 * Cable Modem Termination System is putting out onto 576 * an Ethernet (it doesn't put an Ethernet header onto 577 * the wire, it puts raw DOCSIS frames out on the wire 578 * inside the low-level Ethernet framing). 579 * 580 * A "real Ethernet device" is defined here as a device 581 * that has a link-layer type of DLT_EN10MB and that has 582 * no alternate link-layer types; that's done to exclude 583 * 802.11 interfaces (which might or might not be the 584 * right thing to do, but I suspect it is - Ethernet <-> 585 * 802.11 bridges would probably badly mishandle frames 586 * that don't have Ethernet headers). 587 * 588 * On Solaris with BPF, Ethernet devices also offer 589 * DLT_IPNET, so we, if DLT_IPNET is defined, we don't 590 * treat it as an indication that the device isn't an 591 * Ethernet. 592 */ 593 if (v == DLT_EN10MB) { 594 is_ethernet = 1; 595 for (i = 0; i < bdlp->bfl_len; i++) { 596 if (bdlp->bfl_list[i] != DLT_EN10MB 597 #ifdef DLT_IPNET 598 && bdlp->bfl_list[i] != DLT_IPNET 599 #endif 600 ) { 601 is_ethernet = 0; 602 break; 603 } 604 } 605 if (is_ethernet) { 606 /* 607 * We reserved one more slot at the end of 608 * the list. 609 */ 610 bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS; 611 bdlp->bfl_len++; 612 } 613 } 614 } else { 615 /* 616 * EINVAL just means "we don't support this ioctl on 617 * this device"; don't treat it as an error. 618 */ 619 if (errno != EINVAL) { 620 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, 621 "BIOCGDLTLIST: %s", pcap_strerror(errno)); 622 return (PCAP_ERROR); 623 } 624 } 625 return (0); 626 } 627 #endif 628 629 static int 630 pcap_can_set_rfmon_bpf(pcap_t *p) 631 { 632 #if defined(__APPLE__) 633 struct utsname osinfo; 634 struct ifreq ifr; 635 int fd; 636 #ifdef BIOCGDLTLIST 637 struct bpf_dltlist bdl; 638 #endif 639 640 /* 641 * The joys of monitor mode on OS X. 642 * 643 * Prior to 10.4, it's not supported at all. 644 * 645 * In 10.4, if adapter enN supports monitor mode, there's a 646 * wltN adapter corresponding to it; you open it, instead of 647 * enN, to get monitor mode. You get whatever link-layer 648 * headers it supplies. 649 * 650 * In 10.5, and, we assume, later releases, if adapter enN 651 * supports monitor mode, it offers, among its selectable 652 * DLT_ values, values that let you get the 802.11 header; 653 * selecting one of those values puts the adapter into monitor 654 * mode (i.e., you can't get 802.11 headers except in monitor 655 * mode, and you can't get Ethernet headers in monitor mode). 656 */ 657 if (uname(&osinfo) == -1) { 658 /* 659 * Can't get the OS version; just say "no". 660 */ 661 return (0); 662 } 663 /* 664 * We assume osinfo.sysname is "Darwin", because 665 * __APPLE__ is defined. We just check the version. 666 */ 667 if (osinfo.release[0] < '8' && osinfo.release[1] == '.') { 668 /* 669 * 10.3 (Darwin 7.x) or earlier. 670 * Monitor mode not supported. 671 */ 672 return (0); 673 } 674 if (osinfo.release[0] == '8' && osinfo.release[1] == '.') { 675 /* 676 * 10.4 (Darwin 8.x). s/en/wlt/, and check 677 * whether the device exists. 678 */ 679 if (strncmp(p->opt.source, "en", 2) != 0) { 680 /* 681 * Not an enN device; no monitor mode. 682 */ 683 return (0); 684 } 685 fd = socket(AF_INET, SOCK_DGRAM, 0); 686 if (fd == -1) { 687 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 688 "socket: %s", pcap_strerror(errno)); 689 return (PCAP_ERROR); 690 } 691 strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name)); 692 strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name)); 693 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { 694 /* 695 * No such device? 696 */ 697 close(fd); 698 return (0); 699 } 700 close(fd); 701 return (1); 702 } 703 704 #ifdef BIOCGDLTLIST 705 /* 706 * Everything else is 10.5 or later; for those, 707 * we just open the enN device, and check whether 708 * we have any 802.11 devices. 709 * 710 * First, open a BPF device. 711 */ 712 fd = bpf_open(p); 713 if (fd < 0) 714 return (fd); /* fd is the appropriate error code */ 715 716 /* 717 * Now bind to the device. 718 */ 719 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); 720 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { 721 switch (errno) { 722 723 case ENXIO: 724 /* 725 * There's no such device. 726 */ 727 close(fd); 728 return (PCAP_ERROR_NO_SUCH_DEVICE); 729 730 case ENETDOWN: 731 /* 732 * Return a "network down" indication, so that 733 * the application can report that rather than 734 * saying we had a mysterious failure and 735 * suggest that they report a problem to the 736 * libpcap developers. 737 */ 738 close(fd); 739 return (PCAP_ERROR_IFACE_NOT_UP); 740 741 default: 742 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 743 "BIOCSETIF: %s: %s", 744 p->opt.source, pcap_strerror(errno)); 745 close(fd); 746 return (PCAP_ERROR); 747 } 748 } 749 750 /* 751 * We know the default link type -- now determine all the DLTs 752 * this interface supports. If this fails with EINVAL, it's 753 * not fatal; we just don't get to use the feature later. 754 * (We don't care about DLT_DOCSIS, so we pass DLT_NULL 755 * as the default DLT for this adapter.) 756 */ 757 if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) { 758 close(fd); 759 return (PCAP_ERROR); 760 } 761 if (find_802_11(&bdl) != -1) { 762 /* 763 * We have an 802.11 DLT, so we can set monitor mode. 764 */ 765 free(bdl.bfl_list); 766 close(fd); 767 return (1); 768 } 769 free(bdl.bfl_list); 770 #endif /* BIOCGDLTLIST */ 771 return (0); 772 #elif defined(HAVE_BSD_IEEE80211) 773 int ret; 774 775 ret = monitor_mode(p, 0); 776 if (ret == PCAP_ERROR_RFMON_NOTSUP) 777 return (0); /* not an error, just a "can't do" */ 778 if (ret == 0) 779 return (1); /* success */ 780 return (ret); 781 #else 782 return (0); 783 #endif 784 } 785 786 static int 787 pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) 788 { 789 struct bpf_stat s; 790 791 /* 792 * "ps_recv" counts packets handed to the filter, not packets 793 * that passed the filter. This includes packets later dropped 794 * because we ran out of buffer space. 795 * 796 * "ps_drop" counts packets dropped inside the BPF device 797 * because we ran out of buffer space. It doesn't count 798 * packets dropped by the interface driver. It counts 799 * only packets that passed the filter. 800 * 801 * Both statistics include packets not yet read from the kernel 802 * by libpcap, and thus not yet seen by the application. 803 */ 804 if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) { 805 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s", 806 pcap_strerror(errno)); 807 return (PCAP_ERROR); 808 } 809 810 ps->ps_recv = s.bs_recv; 811 ps->ps_drop = s.bs_drop; 812 ps->ps_ifdrop = 0; 813 return (0); 814 } 815 816 static int 817 pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 818 { 819 int cc; 820 int n = 0; 821 register u_char *bp, *ep; 822 u_char *datap; 823 #ifdef PCAP_FDDIPAD 824 register int pad; 825 #endif 826 #ifdef HAVE_ZEROCOPY_BPF 827 int i; 828 #endif 829 830 again: 831 /* 832 * Has "pcap_breakloop()" been called? 833 */ 834 if (p->break_loop) { 835 /* 836 * Yes - clear the flag that indicates that it 837 * has, and return PCAP_ERROR_BREAK to indicate 838 * that we were told to break out of the loop. 839 */ 840 p->break_loop = 0; 841 return (PCAP_ERROR_BREAK); 842 } 843 cc = p->cc; 844 if (p->cc == 0) { 845 /* 846 * When reading without zero-copy from a file descriptor, we 847 * use a single buffer and return a length of data in the 848 * buffer. With zero-copy, we update the p->buffer pointer 849 * to point at whatever underlying buffer contains the next 850 * data and update cc to reflect the data found in the 851 * buffer. 852 */ 853 #ifdef HAVE_ZEROCOPY_BPF 854 if (p->md.zerocopy) { 855 if (p->buffer != NULL) 856 pcap_ack_zbuf(p); 857 i = pcap_next_zbuf(p, &cc); 858 if (i == 0) 859 goto again; 860 if (i < 0) 861 return (PCAP_ERROR); 862 } else 863 #endif 864 { 865 cc = read(p->fd, (char *)p->buffer, p->bufsize); 866 } 867 if (cc < 0) { 868 /* Don't choke when we get ptraced */ 869 switch (errno) { 870 871 case EINTR: 872 goto again; 873 874 #ifdef _AIX 875 case EFAULT: 876 /* 877 * Sigh. More AIX wonderfulness. 878 * 879 * For some unknown reason the uiomove() 880 * operation in the bpf kernel extension 881 * used to copy the buffer into user 882 * space sometimes returns EFAULT. I have 883 * no idea why this is the case given that 884 * a kernel debugger shows the user buffer 885 * is correct. This problem appears to 886 * be mostly mitigated by the memset of 887 * the buffer before it is first used. 888 * Very strange.... Shaun Clowes 889 * 890 * In any case this means that we shouldn't 891 * treat EFAULT as a fatal error; as we 892 * don't have an API for returning 893 * a "some packets were dropped since 894 * the last packet you saw" indication, 895 * we just ignore EFAULT and keep reading. 896 */ 897 goto again; 898 #endif 899 900 case EWOULDBLOCK: 901 return (0); 902 903 case ENXIO: 904 /* 905 * The device on which we're capturing 906 * went away. 907 * 908 * XXX - we should really return 909 * PCAP_ERROR_IFACE_NOT_UP, but 910 * pcap_dispatch() etc. aren't 911 * defined to retur that. 912 */ 913 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 914 "The interface went down"); 915 return (PCAP_ERROR); 916 917 #if defined(sun) && !defined(BSD) && !defined(__svr4__) && !defined(__SVR4) 918 /* 919 * Due to a SunOS bug, after 2^31 bytes, the kernel 920 * file offset overflows and read fails with EINVAL. 921 * The lseek() to 0 will fix things. 922 */ 923 case EINVAL: 924 if (lseek(p->fd, 0L, SEEK_CUR) + 925 p->bufsize < 0) { 926 (void)lseek(p->fd, 0L, SEEK_SET); 927 goto again; 928 } 929 /* fall through */ 930 #endif 931 } 932 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s", 933 pcap_strerror(errno)); 934 return (PCAP_ERROR); 935 } 936 bp = p->buffer; 937 } else 938 bp = p->bp; 939 940 /* 941 * Loop through each packet. 942 */ 943 #define bhp ((struct bpf_hdr *)bp) 944 ep = bp + cc; 945 #ifdef PCAP_FDDIPAD 946 pad = p->fddipad; 947 #endif 948 while (bp < ep) { 949 register int caplen, hdrlen; 950 951 /* 952 * Has "pcap_breakloop()" been called? 953 * If so, return immediately - if we haven't read any 954 * packets, clear the flag and return PCAP_ERROR_BREAK 955 * to indicate that we were told to break out of the loop, 956 * otherwise leave the flag set, so that the *next* call 957 * will break out of the loop without having read any 958 * packets, and return the number of packets we've 959 * processed so far. 960 */ 961 if (p->break_loop) { 962 p->bp = bp; 963 p->cc = ep - bp; 964 /* 965 * ep is set based on the return value of read(), 966 * but read() from a BPF device doesn't necessarily 967 * return a value that's a multiple of the alignment 968 * value for BPF_WORDALIGN(). However, whenever we 969 * increment bp, we round up the increment value by 970 * a value rounded up by BPF_WORDALIGN(), so we 971 * could increment bp past ep after processing the 972 * last packet in the buffer. 973 * 974 * We treat ep < bp as an indication that this 975 * happened, and just set p->cc to 0. 976 */ 977 if (p->cc < 0) 978 p->cc = 0; 979 if (n == 0) { 980 p->break_loop = 0; 981 return (PCAP_ERROR_BREAK); 982 } else 983 return (n); 984 } 985 986 caplen = bhp->bh_caplen; 987 hdrlen = bhp->bh_hdrlen; 988 datap = bp + hdrlen; 989 /* 990 * Short-circuit evaluation: if using BPF filter 991 * in kernel, no need to do it now - we already know 992 * the packet passed the filter. 993 * 994 #ifdef PCAP_FDDIPAD 995 * Note: the filter code was generated assuming 996 * that p->fddipad was the amount of padding 997 * before the header, as that's what's required 998 * in the kernel, so we run the filter before 999 * skipping that padding. 1000 #endif 1001 */ 1002 if (p->md.use_bpf || 1003 bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) { 1004 struct pcap_pkthdr pkthdr; 1005 1006 pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec; 1007 #ifdef _AIX 1008 /* 1009 * AIX's BPF returns seconds/nanoseconds time 1010 * stamps, not seconds/microseconds time stamps. 1011 */ 1012 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000; 1013 #else 1014 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec; 1015 #endif 1016 #ifdef PCAP_FDDIPAD 1017 if (caplen > pad) 1018 pkthdr.caplen = caplen - pad; 1019 else 1020 pkthdr.caplen = 0; 1021 if (bhp->bh_datalen > pad) 1022 pkthdr.len = bhp->bh_datalen - pad; 1023 else 1024 pkthdr.len = 0; 1025 datap += pad; 1026 #else 1027 pkthdr.caplen = caplen; 1028 pkthdr.len = bhp->bh_datalen; 1029 #endif 1030 (*callback)(user, &pkthdr, datap); 1031 bp += BPF_WORDALIGN(caplen + hdrlen); 1032 if (++n >= cnt && cnt > 0) { 1033 p->bp = bp; 1034 p->cc = ep - bp; 1035 /* 1036 * See comment above about p->cc < 0. 1037 */ 1038 if (p->cc < 0) 1039 p->cc = 0; 1040 return (n); 1041 } 1042 } else { 1043 /* 1044 * Skip this packet. 1045 */ 1046 bp += BPF_WORDALIGN(caplen + hdrlen); 1047 } 1048 } 1049 #undef bhp 1050 p->cc = 0; 1051 return (n); 1052 } 1053 1054 static int 1055 pcap_inject_bpf(pcap_t *p, const void *buf, size_t size) 1056 { 1057 int ret; 1058 1059 ret = write(p->fd, buf, size); 1060 #ifdef __APPLE__ 1061 if (ret == -1 && errno == EAFNOSUPPORT) { 1062 /* 1063 * In Mac OS X, there's a bug wherein setting the 1064 * BIOCSHDRCMPLT flag causes writes to fail; see, 1065 * for example: 1066 * 1067 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch 1068 * 1069 * So, if, on OS X, we get EAFNOSUPPORT from the write, we 1070 * assume it's due to that bug, and turn off that flag 1071 * and try again. If we succeed, it either means that 1072 * somebody applied the fix from that URL, or other patches 1073 * for that bug from 1074 * 1075 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/ 1076 * 1077 * and are running a Darwin kernel with those fixes, or 1078 * that Apple fixed the problem in some OS X release. 1079 */ 1080 u_int spoof_eth_src = 0; 1081 1082 if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 1083 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1084 "send: can't turn off BIOCSHDRCMPLT: %s", 1085 pcap_strerror(errno)); 1086 return (PCAP_ERROR); 1087 } 1088 1089 /* 1090 * Now try the write again. 1091 */ 1092 ret = write(p->fd, buf, size); 1093 } 1094 #endif /* __APPLE__ */ 1095 if (ret == -1) { 1096 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 1097 pcap_strerror(errno)); 1098 return (PCAP_ERROR); 1099 } 1100 return (ret); 1101 } 1102 1103 #ifdef _AIX 1104 static int 1105 bpf_odminit(char *errbuf) 1106 { 1107 char *errstr; 1108 1109 if (odm_initialize() == -1) { 1110 if (odm_err_msg(odmerrno, &errstr) == -1) 1111 errstr = "Unknown error"; 1112 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1113 "bpf_load: odm_initialize failed: %s", 1114 errstr); 1115 return (PCAP_ERROR); 1116 } 1117 1118 if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) { 1119 if (odm_err_msg(odmerrno, &errstr) == -1) 1120 errstr = "Unknown error"; 1121 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1122 "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s", 1123 errstr); 1124 (void)odm_terminate(); 1125 return (PCAP_ERROR); 1126 } 1127 1128 return (0); 1129 } 1130 1131 static int 1132 bpf_odmcleanup(char *errbuf) 1133 { 1134 char *errstr; 1135 1136 if (odm_unlock(odmlockid) == -1) { 1137 if (errbuf != NULL) { 1138 if (odm_err_msg(odmerrno, &errstr) == -1) 1139 errstr = "Unknown error"; 1140 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1141 "bpf_load: odm_unlock failed: %s", 1142 errstr); 1143 } 1144 return (PCAP_ERROR); 1145 } 1146 1147 if (odm_terminate() == -1) { 1148 if (errbuf != NULL) { 1149 if (odm_err_msg(odmerrno, &errstr) == -1) 1150 errstr = "Unknown error"; 1151 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1152 "bpf_load: odm_terminate failed: %s", 1153 errstr); 1154 } 1155 return (PCAP_ERROR); 1156 } 1157 1158 return (0); 1159 } 1160 1161 static int 1162 bpf_load(char *errbuf) 1163 { 1164 long major; 1165 int *minors; 1166 int numminors, i, rc; 1167 char buf[1024]; 1168 struct stat sbuf; 1169 struct bpf_config cfg_bpf; 1170 struct cfg_load cfg_ld; 1171 struct cfg_kmod cfg_km; 1172 1173 /* 1174 * This is very very close to what happens in the real implementation 1175 * but I've fixed some (unlikely) bug situations. 1176 */ 1177 if (bpfloadedflag) 1178 return (0); 1179 1180 if (bpf_odminit(errbuf) == PCAP_ERROR) 1181 return (PCAP_ERROR); 1182 1183 major = genmajor(BPF_NAME); 1184 if (major == -1) { 1185 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1186 "bpf_load: genmajor failed: %s", pcap_strerror(errno)); 1187 (void)bpf_odmcleanup(NULL); 1188 return (PCAP_ERROR); 1189 } 1190 1191 minors = getminor(major, &numminors, BPF_NAME); 1192 if (!minors) { 1193 minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1); 1194 if (!minors) { 1195 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1196 "bpf_load: genminor failed: %s", 1197 pcap_strerror(errno)); 1198 (void)bpf_odmcleanup(NULL); 1199 return (PCAP_ERROR); 1200 } 1201 } 1202 1203 if (bpf_odmcleanup(errbuf) == PCAP_ERROR) 1204 return (PCAP_ERROR); 1205 1206 rc = stat(BPF_NODE "0", &sbuf); 1207 if (rc == -1 && errno != ENOENT) { 1208 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1209 "bpf_load: can't stat %s: %s", 1210 BPF_NODE "0", pcap_strerror(errno)); 1211 return (PCAP_ERROR); 1212 } 1213 1214 if (rc == -1 || getmajor(sbuf.st_rdev) != major) { 1215 for (i = 0; i < BPF_MINORS; i++) { 1216 sprintf(buf, "%s%d", BPF_NODE, i); 1217 unlink(buf); 1218 if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) { 1219 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1220 "bpf_load: can't mknod %s: %s", 1221 buf, pcap_strerror(errno)); 1222 return (PCAP_ERROR); 1223 } 1224 } 1225 } 1226 1227 /* Check if the driver is loaded */ 1228 memset(&cfg_ld, 0x0, sizeof(cfg_ld)); 1229 cfg_ld.path = buf; 1230 sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME); 1231 if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) || 1232 (cfg_ld.kmid == 0)) { 1233 /* Driver isn't loaded, load it now */ 1234 if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) { 1235 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1236 "bpf_load: could not load driver: %s", 1237 strerror(errno)); 1238 return (PCAP_ERROR); 1239 } 1240 } 1241 1242 /* Configure the driver */ 1243 cfg_km.cmd = CFG_INIT; 1244 cfg_km.kmid = cfg_ld.kmid; 1245 cfg_km.mdilen = sizeof(cfg_bpf); 1246 cfg_km.mdiptr = (void *)&cfg_bpf; 1247 for (i = 0; i < BPF_MINORS; i++) { 1248 cfg_bpf.devno = domakedev(major, i); 1249 if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) { 1250 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1251 "bpf_load: could not configure driver: %s", 1252 strerror(errno)); 1253 return (PCAP_ERROR); 1254 } 1255 } 1256 1257 bpfloadedflag = 1; 1258 1259 return (0); 1260 } 1261 #endif 1262 1263 /* 1264 * Turn off rfmon mode if necessary. 1265 */ 1266 static void 1267 pcap_cleanup_bpf(pcap_t *p) 1268 { 1269 #ifdef HAVE_BSD_IEEE80211 1270 int sock; 1271 struct ifmediareq req; 1272 struct ifreq ifr; 1273 #endif 1274 1275 if (p->md.must_do_on_close != 0) { 1276 /* 1277 * There's something we have to do when closing this 1278 * pcap_t. 1279 */ 1280 #ifdef HAVE_BSD_IEEE80211 1281 if (p->md.must_do_on_close & MUST_CLEAR_RFMON) { 1282 /* 1283 * We put the interface into rfmon mode; 1284 * take it out of rfmon mode. 1285 * 1286 * XXX - if somebody else wants it in rfmon 1287 * mode, this code cannot know that, so it'll take 1288 * it out of rfmon mode. 1289 */ 1290 sock = socket(AF_INET, SOCK_DGRAM, 0); 1291 if (sock == -1) { 1292 fprintf(stderr, 1293 "Can't restore interface flags (socket() failed: %s).\n" 1294 "Please adjust manually.\n", 1295 strerror(errno)); 1296 } else { 1297 memset(&req, 0, sizeof(req)); 1298 strncpy(req.ifm_name, p->md.device, 1299 sizeof(req.ifm_name)); 1300 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 1301 fprintf(stderr, 1302 "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n" 1303 "Please adjust manually.\n", 1304 strerror(errno)); 1305 } else { 1306 if (req.ifm_current & IFM_IEEE80211_MONITOR) { 1307 /* 1308 * Rfmon mode is currently on; 1309 * turn it off. 1310 */ 1311 memset(&ifr, 0, sizeof(ifr)); 1312 (void)strncpy(ifr.ifr_name, 1313 p->md.device, 1314 sizeof(ifr.ifr_name)); 1315 ifr.ifr_media = 1316 req.ifm_current & ~IFM_IEEE80211_MONITOR; 1317 if (ioctl(sock, SIOCSIFMEDIA, 1318 &ifr) == -1) { 1319 fprintf(stderr, 1320 "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n" 1321 "Please adjust manually.\n", 1322 strerror(errno)); 1323 } 1324 } 1325 } 1326 close(sock); 1327 } 1328 } 1329 #endif /* HAVE_BSD_IEEE80211 */ 1330 1331 /* 1332 * Take this pcap out of the list of pcaps for which we 1333 * have to take the interface out of some mode. 1334 */ 1335 pcap_remove_from_pcaps_to_close(p); 1336 p->md.must_do_on_close = 0; 1337 } 1338 1339 #ifdef HAVE_ZEROCOPY_BPF 1340 if (p->md.zerocopy) { 1341 /* 1342 * Delete the mappings. Note that p->buffer gets 1343 * initialized to one of the mmapped regions in 1344 * this case, so do not try and free it directly; 1345 * null it out so that pcap_cleanup_live_common() 1346 * doesn't try to free it. 1347 */ 1348 if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL) 1349 (void) munmap(p->md.zbuf1, p->md.zbufsize); 1350 if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL) 1351 (void) munmap(p->md.zbuf2, p->md.zbufsize); 1352 p->buffer = NULL; 1353 } 1354 #endif 1355 if (p->md.device != NULL) { 1356 free(p->md.device); 1357 p->md.device = NULL; 1358 } 1359 pcap_cleanup_live_common(p); 1360 } 1361 1362 static int 1363 check_setif_failure(pcap_t *p, int error) 1364 { 1365 #ifdef __APPLE__ 1366 int fd; 1367 struct ifreq ifr; 1368 int err; 1369 #endif 1370 1371 if (error == ENXIO) { 1372 /* 1373 * No such device exists. 1374 */ 1375 #ifdef __APPLE__ 1376 if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) { 1377 /* 1378 * Monitor mode was requested, and we're trying 1379 * to open a "wltN" device. Assume that this 1380 * is 10.4 and that we were asked to open an 1381 * "enN" device; if that device exists, return 1382 * "monitor mode not supported on the device". 1383 */ 1384 fd = socket(AF_INET, SOCK_DGRAM, 0); 1385 if (fd != -1) { 1386 strlcpy(ifr.ifr_name, "en", 1387 sizeof(ifr.ifr_name)); 1388 strlcat(ifr.ifr_name, p->opt.source + 3, 1389 sizeof(ifr.ifr_name)); 1390 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { 1391 /* 1392 * We assume this failed because 1393 * the underlying device doesn't 1394 * exist. 1395 */ 1396 err = PCAP_ERROR_NO_SUCH_DEVICE; 1397 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1398 "SIOCGIFFLAGS on %s failed: %s", 1399 ifr.ifr_name, pcap_strerror(errno)); 1400 } else { 1401 /* 1402 * The underlying "enN" device 1403 * exists, but there's no 1404 * corresponding "wltN" device; 1405 * that means that the "enN" 1406 * device doesn't support 1407 * monitor mode, probably because 1408 * it's an Ethernet device rather 1409 * than a wireless device. 1410 */ 1411 err = PCAP_ERROR_RFMON_NOTSUP; 1412 } 1413 close(fd); 1414 } else { 1415 /* 1416 * We can't find out whether there's 1417 * an underlying "enN" device, so 1418 * just report "no such device". 1419 */ 1420 err = PCAP_ERROR_NO_SUCH_DEVICE; 1421 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1422 "socket() failed: %s", 1423 pcap_strerror(errno)); 1424 } 1425 return (err); 1426 } 1427 #endif 1428 /* 1429 * No such device. 1430 */ 1431 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF failed: %s", 1432 pcap_strerror(errno)); 1433 return (PCAP_ERROR_NO_SUCH_DEVICE); 1434 } else if (errno == ENETDOWN) { 1435 /* 1436 * Return a "network down" indication, so that 1437 * the application can report that rather than 1438 * saying we had a mysterious failure and 1439 * suggest that they report a problem to the 1440 * libpcap developers. 1441 */ 1442 return (PCAP_ERROR_IFACE_NOT_UP); 1443 } else { 1444 /* 1445 * Some other error; fill in the error string, and 1446 * return PCAP_ERROR. 1447 */ 1448 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", 1449 p->opt.source, pcap_strerror(errno)); 1450 return (PCAP_ERROR); 1451 } 1452 } 1453 1454 /* 1455 * Default capture buffer size. 1456 * 32K isn't very much for modern machines with fast networks; we 1457 * pick .5M, as that's the maximum on at least some systems with BPF. 1458 * 1459 * However, on AIX 3.5, the larger buffer sized caused unrecoverable 1460 * read failures under stress, so we leave it as 32K; yet another 1461 * place where AIX's BPF is broken. 1462 */ 1463 #ifdef _AIX 1464 #define DEFAULT_BUFSIZE 32768 1465 #else 1466 #define DEFAULT_BUFSIZE 524288 1467 #endif 1468 1469 static int 1470 pcap_activate_bpf(pcap_t *p) 1471 { 1472 int status = 0; 1473 int fd; 1474 #ifdef LIFNAMSIZ 1475 char *zonesep; 1476 struct lifreq ifr; 1477 char *ifrname = ifr.lifr_name; 1478 const size_t ifnamsiz = sizeof(ifr.lifr_name); 1479 #else 1480 struct ifreq ifr; 1481 char *ifrname = ifr.ifr_name; 1482 const size_t ifnamsiz = sizeof(ifr.ifr_name); 1483 #endif 1484 struct bpf_version bv; 1485 #ifdef __APPLE__ 1486 int sockfd; 1487 char *wltdev = NULL; 1488 #endif 1489 #ifdef BIOCGDLTLIST 1490 struct bpf_dltlist bdl; 1491 #if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 1492 int new_dlt; 1493 #endif 1494 #endif /* BIOCGDLTLIST */ 1495 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 1496 u_int spoof_eth_src = 1; 1497 #endif 1498 u_int v; 1499 struct bpf_insn total_insn; 1500 struct bpf_program total_prog; 1501 struct utsname osinfo; 1502 int have_osinfo = 0; 1503 #ifdef HAVE_ZEROCOPY_BPF 1504 struct bpf_zbuf bz; 1505 u_int bufmode, zbufmax; 1506 #endif 1507 1508 fd = bpf_open(p); 1509 if (fd < 0) { 1510 status = fd; 1511 goto bad; 1512 } 1513 1514 p->fd = fd; 1515 1516 if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) { 1517 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s", 1518 pcap_strerror(errno)); 1519 status = PCAP_ERROR; 1520 goto bad; 1521 } 1522 if (bv.bv_major != BPF_MAJOR_VERSION || 1523 bv.bv_minor < BPF_MINOR_VERSION) { 1524 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1525 "kernel bpf filter out of date"); 1526 status = PCAP_ERROR; 1527 goto bad; 1528 } 1529 1530 #if defined(LIFNAMSIZ) && defined(ZONENAME_MAX) && defined(lifr_zoneid) 1531 /* 1532 * Check if the given source network device has a '/' separated 1533 * zonename prefix string. The zonename prefixed source device 1534 * can be used by libpcap consumers to capture network traffic 1535 * in non-global zones from the global zone on Solaris 11 and 1536 * above. If the zonename prefix is present then we strip the 1537 * prefix and pass the zone ID as part of lifr_zoneid. 1538 */ 1539 if ((zonesep = strchr(p->opt.source, '/')) != NULL) { 1540 char zonename[ZONENAME_MAX]; 1541 int znamelen; 1542 char *lnamep; 1543 1544 znamelen = zonesep - p->opt.source; 1545 (void) strlcpy(zonename, p->opt.source, znamelen + 1); 1546 lnamep = strdup(zonesep + 1); 1547 ifr.lifr_zoneid = getzoneidbyname(zonename); 1548 free(p->opt.source); 1549 p->opt.source = lnamep; 1550 } 1551 #endif 1552 1553 p->md.device = strdup(p->opt.source); 1554 if (p->md.device == NULL) { 1555 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s", 1556 pcap_strerror(errno)); 1557 status = PCAP_ERROR; 1558 goto bad; 1559 } 1560 1561 /* 1562 * Attempt to find out the version of the OS on which we're running. 1563 */ 1564 if (uname(&osinfo) == 0) 1565 have_osinfo = 1; 1566 1567 #ifdef __APPLE__ 1568 /* 1569 * See comment in pcap_can_set_rfmon_bpf() for an explanation 1570 * of why we check the version number. 1571 */ 1572 if (p->opt.rfmon) { 1573 if (have_osinfo) { 1574 /* 1575 * We assume osinfo.sysname is "Darwin", because 1576 * __APPLE__ is defined. We just check the version. 1577 */ 1578 if (osinfo.release[0] < '8' && 1579 osinfo.release[1] == '.') { 1580 /* 1581 * 10.3 (Darwin 7.x) or earlier. 1582 */ 1583 status = PCAP_ERROR_RFMON_NOTSUP; 1584 goto bad; 1585 } 1586 if (osinfo.release[0] == '8' && 1587 osinfo.release[1] == '.') { 1588 /* 1589 * 10.4 (Darwin 8.x). s/en/wlt/ 1590 */ 1591 if (strncmp(p->opt.source, "en", 2) != 0) { 1592 /* 1593 * Not an enN device; check 1594 * whether the device even exists. 1595 */ 1596 sockfd = socket(AF_INET, SOCK_DGRAM, 0); 1597 if (sockfd != -1) { 1598 strlcpy(ifrname, 1599 p->opt.source, ifnamsiz); 1600 if (ioctl(sockfd, SIOCGIFFLAGS, 1601 (char *)&ifr) < 0) { 1602 /* 1603 * We assume this 1604 * failed because 1605 * the underlying 1606 * device doesn't 1607 * exist. 1608 */ 1609 status = PCAP_ERROR_NO_SUCH_DEVICE; 1610 snprintf(p->errbuf, 1611 PCAP_ERRBUF_SIZE, 1612 "SIOCGIFFLAGS failed: %s", 1613 pcap_strerror(errno)); 1614 } else 1615 status = PCAP_ERROR_RFMON_NOTSUP; 1616 close(sockfd); 1617 } else { 1618 /* 1619 * We can't find out whether 1620 * the device exists, so just 1621 * report "no such device". 1622 */ 1623 status = PCAP_ERROR_NO_SUCH_DEVICE; 1624 snprintf(p->errbuf, 1625 PCAP_ERRBUF_SIZE, 1626 "socket() failed: %s", 1627 pcap_strerror(errno)); 1628 } 1629 goto bad; 1630 } 1631 wltdev = malloc(strlen(p->opt.source) + 2); 1632 if (wltdev == NULL) { 1633 (void)snprintf(p->errbuf, 1634 PCAP_ERRBUF_SIZE, "malloc: %s", 1635 pcap_strerror(errno)); 1636 status = PCAP_ERROR; 1637 goto bad; 1638 } 1639 strcpy(wltdev, "wlt"); 1640 strcat(wltdev, p->opt.source + 2); 1641 free(p->opt.source); 1642 p->opt.source = wltdev; 1643 } 1644 /* 1645 * Everything else is 10.5 or later; for those, 1646 * we just open the enN device, and set the DLT. 1647 */ 1648 } 1649 } 1650 #endif /* __APPLE__ */ 1651 #ifdef HAVE_ZEROCOPY_BPF 1652 /* 1653 * If the BPF extension to set buffer mode is present, try setting 1654 * the mode to zero-copy. If that fails, use regular buffering. If 1655 * it succeeds but other setup fails, return an error to the user. 1656 */ 1657 bufmode = BPF_BUFMODE_ZBUF; 1658 if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) { 1659 /* 1660 * We have zerocopy BPF; use it. 1661 */ 1662 p->md.zerocopy = 1; 1663 1664 /* 1665 * How to pick a buffer size: first, query the maximum buffer 1666 * size supported by zero-copy. This also lets us quickly 1667 * determine whether the kernel generally supports zero-copy. 1668 * Then, if a buffer size was specified, use that, otherwise 1669 * query the default buffer size, which reflects kernel 1670 * policy for a desired default. Round to the nearest page 1671 * size. 1672 */ 1673 if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) { 1674 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s", 1675 pcap_strerror(errno)); 1676 goto bad; 1677 } 1678 1679 if (p->opt.buffer_size != 0) { 1680 /* 1681 * A buffer size was explicitly specified; use it. 1682 */ 1683 v = p->opt.buffer_size; 1684 } else { 1685 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 1686 v < DEFAULT_BUFSIZE) 1687 v = DEFAULT_BUFSIZE; 1688 } 1689 #ifndef roundup 1690 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 1691 #endif 1692 p->md.zbufsize = roundup(v, getpagesize()); 1693 if (p->md.zbufsize > zbufmax) 1694 p->md.zbufsize = zbufmax; 1695 p->md.zbuf1 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE, 1696 MAP_ANON, -1, 0); 1697 p->md.zbuf2 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE, 1698 MAP_ANON, -1, 0); 1699 if (p->md.zbuf1 == MAP_FAILED || p->md.zbuf2 == MAP_FAILED) { 1700 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s", 1701 pcap_strerror(errno)); 1702 goto bad; 1703 } 1704 bzero(&bz, sizeof(bz)); 1705 bz.bz_bufa = p->md.zbuf1; 1706 bz.bz_bufb = p->md.zbuf2; 1707 bz.bz_buflen = p->md.zbufsize; 1708 if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) { 1709 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s", 1710 pcap_strerror(errno)); 1711 goto bad; 1712 } 1713 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1714 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { 1715 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", 1716 p->opt.source, pcap_strerror(errno)); 1717 goto bad; 1718 } 1719 v = p->md.zbufsize - sizeof(struct bpf_zbuf_header); 1720 } else 1721 #endif 1722 { 1723 /* 1724 * We don't have zerocopy BPF. 1725 * Set the buffer size. 1726 */ 1727 if (p->opt.buffer_size != 0) { 1728 /* 1729 * A buffer size was explicitly specified; use it. 1730 */ 1731 if (ioctl(fd, BIOCSBLEN, 1732 (caddr_t)&p->opt.buffer_size) < 0) { 1733 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1734 "BIOCSBLEN: %s: %s", p->opt.source, 1735 pcap_strerror(errno)); 1736 status = PCAP_ERROR; 1737 goto bad; 1738 } 1739 1740 /* 1741 * Now bind to the device. 1742 */ 1743 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1744 #ifdef BIOCSETLIF 1745 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) < 0) 1746 #else 1747 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) 1748 #endif 1749 { 1750 status = check_setif_failure(p, errno); 1751 goto bad; 1752 } 1753 } else { 1754 /* 1755 * No buffer size was explicitly specified. 1756 * 1757 * Try finding a good size for the buffer; 1758 * DEFAULT_BUFSIZE may be too big, so keep 1759 * cutting it in half until we find a size 1760 * that works, or run out of sizes to try. 1761 * If the default is larger, don't make it smaller. 1762 */ 1763 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 1764 v < DEFAULT_BUFSIZE) 1765 v = DEFAULT_BUFSIZE; 1766 for ( ; v != 0; v >>= 1) { 1767 /* 1768 * Ignore the return value - this is because the 1769 * call fails on BPF systems that don't have 1770 * kernel malloc. And if the call fails, it's 1771 * no big deal, we just continue to use the 1772 * standard buffer size. 1773 */ 1774 (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v); 1775 1776 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1777 #ifdef BIOCSETLIF 1778 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) >= 0) 1779 #else 1780 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0) 1781 #endif 1782 break; /* that size worked; we're done */ 1783 1784 if (errno != ENOBUFS) { 1785 status = check_setif_failure(p, errno); 1786 goto bad; 1787 } 1788 } 1789 1790 if (v == 0) { 1791 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1792 "BIOCSBLEN: %s: No buffer size worked", 1793 p->opt.source); 1794 status = PCAP_ERROR; 1795 goto bad; 1796 } 1797 } 1798 } 1799 1800 /* Get the data link layer type. */ 1801 if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) { 1802 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s", 1803 pcap_strerror(errno)); 1804 status = PCAP_ERROR; 1805 goto bad; 1806 } 1807 1808 #ifdef _AIX 1809 /* 1810 * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT. 1811 */ 1812 switch (v) { 1813 1814 case IFT_ETHER: 1815 case IFT_ISO88023: 1816 v = DLT_EN10MB; 1817 break; 1818 1819 case IFT_FDDI: 1820 v = DLT_FDDI; 1821 break; 1822 1823 case IFT_ISO88025: 1824 v = DLT_IEEE802; 1825 break; 1826 1827 case IFT_LOOP: 1828 v = DLT_NULL; 1829 break; 1830 1831 default: 1832 /* 1833 * We don't know what to map this to yet. 1834 */ 1835 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", 1836 v); 1837 status = PCAP_ERROR; 1838 goto bad; 1839 } 1840 #endif 1841 #if _BSDI_VERSION - 0 >= 199510 1842 /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */ 1843 switch (v) { 1844 1845 case DLT_SLIP: 1846 v = DLT_SLIP_BSDOS; 1847 break; 1848 1849 case DLT_PPP: 1850 v = DLT_PPP_BSDOS; 1851 break; 1852 1853 case 11: /*DLT_FR*/ 1854 v = DLT_FRELAY; 1855 break; 1856 1857 case 12: /*DLT_C_HDLC*/ 1858 v = DLT_CHDLC; 1859 break; 1860 } 1861 #endif 1862 1863 #ifdef BIOCGDLTLIST 1864 /* 1865 * We know the default link type -- now determine all the DLTs 1866 * this interface supports. If this fails with EINVAL, it's 1867 * not fatal; we just don't get to use the feature later. 1868 */ 1869 if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) { 1870 status = PCAP_ERROR; 1871 goto bad; 1872 } 1873 p->dlt_count = bdl.bfl_len; 1874 p->dlt_list = bdl.bfl_list; 1875 1876 #ifdef __APPLE__ 1877 /* 1878 * Monitor mode fun, continued. 1879 * 1880 * For 10.5 and, we're assuming, later releases, as noted above, 1881 * 802.1 adapters that support monitor mode offer both DLT_EN10MB, 1882 * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information 1883 * DLT_ value. Choosing one of the 802.11 DLT_ values will turn 1884 * monitor mode on. 1885 * 1886 * Therefore, if the user asked for monitor mode, we filter out 1887 * the DLT_EN10MB value, as you can't get that in monitor mode, 1888 * and, if the user didn't ask for monitor mode, we filter out 1889 * the 802.11 DLT_ values, because selecting those will turn 1890 * monitor mode on. Then, for monitor mode, if an 802.11-plus- 1891 * radio DLT_ value is offered, we try to select that, otherwise 1892 * we try to select DLT_IEEE802_11. 1893 */ 1894 if (have_osinfo) { 1895 if (isdigit((unsigned)osinfo.release[0]) && 1896 (osinfo.release[0] == '9' || 1897 isdigit((unsigned)osinfo.release[1]))) { 1898 /* 1899 * 10.5 (Darwin 9.x), or later. 1900 */ 1901 new_dlt = find_802_11(&bdl); 1902 if (new_dlt != -1) { 1903 /* 1904 * We have at least one 802.11 DLT_ value, 1905 * so this is an 802.11 interface. 1906 * new_dlt is the best of the 802.11 1907 * DLT_ values in the list. 1908 */ 1909 if (p->opt.rfmon) { 1910 /* 1911 * Our caller wants monitor mode. 1912 * Purge DLT_EN10MB from the list 1913 * of link-layer types, as selecting 1914 * it will keep monitor mode off. 1915 */ 1916 remove_en(p); 1917 1918 /* 1919 * If the new mode we want isn't 1920 * the default mode, attempt to 1921 * select the new mode. 1922 */ 1923 if (new_dlt != v) { 1924 if (ioctl(p->fd, BIOCSDLT, 1925 &new_dlt) != -1) { 1926 /* 1927 * We succeeded; 1928 * make this the 1929 * new DLT_ value. 1930 */ 1931 v = new_dlt; 1932 } 1933 } 1934 } else { 1935 /* 1936 * Our caller doesn't want 1937 * monitor mode. Unless this 1938 * is being done by pcap_open_live(), 1939 * purge the 802.11 link-layer types 1940 * from the list, as selecting 1941 * one of them will turn monitor 1942 * mode on. 1943 */ 1944 if (!p->oldstyle) 1945 remove_802_11(p); 1946 } 1947 } else { 1948 if (p->opt.rfmon) { 1949 /* 1950 * The caller requested monitor 1951 * mode, but we have no 802.11 1952 * link-layer types, so they 1953 * can't have it. 1954 */ 1955 status = PCAP_ERROR_RFMON_NOTSUP; 1956 goto bad; 1957 } 1958 } 1959 } 1960 } 1961 #elif defined(HAVE_BSD_IEEE80211) 1962 /* 1963 * *BSD with the new 802.11 ioctls. 1964 * Do we want monitor mode? 1965 */ 1966 if (p->opt.rfmon) { 1967 /* 1968 * Try to put the interface into monitor mode. 1969 */ 1970 status = monitor_mode(p, 1); 1971 if (status != 0) { 1972 /* 1973 * We failed. 1974 */ 1975 goto bad; 1976 } 1977 1978 /* 1979 * We're in monitor mode. 1980 * Try to find the best 802.11 DLT_ value and, if we 1981 * succeed, try to switch to that mode if we're not 1982 * already in that mode. 1983 */ 1984 new_dlt = find_802_11(&bdl); 1985 if (new_dlt != -1) { 1986 /* 1987 * We have at least one 802.11 DLT_ value. 1988 * new_dlt is the best of the 802.11 1989 * DLT_ values in the list. 1990 * 1991 * If the new mode we want isn't the default mode, 1992 * attempt to select the new mode. 1993 */ 1994 if (new_dlt != v) { 1995 if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) { 1996 /* 1997 * We succeeded; make this the 1998 * new DLT_ value. 1999 */ 2000 v = new_dlt; 2001 } 2002 } 2003 } 2004 } 2005 #endif /* various platforms */ 2006 #endif /* BIOCGDLTLIST */ 2007 2008 /* 2009 * If this is an Ethernet device, and we don't have a DLT_ list, 2010 * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give 2011 * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to 2012 * do, but there's not much we can do about that without finding 2013 * some other way of determining whether it's an Ethernet or 802.11 2014 * device.) 2015 */ 2016 if (v == DLT_EN10MB && p->dlt_count == 0) { 2017 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 2018 /* 2019 * If that fails, just leave the list empty. 2020 */ 2021 if (p->dlt_list != NULL) { 2022 p->dlt_list[0] = DLT_EN10MB; 2023 p->dlt_list[1] = DLT_DOCSIS; 2024 p->dlt_count = 2; 2025 } 2026 } 2027 #ifdef PCAP_FDDIPAD 2028 if (v == DLT_FDDI) 2029 p->fddipad = PCAP_FDDIPAD; 2030 else 2031 p->fddipad = 0; 2032 #endif 2033 p->linktype = v; 2034 2035 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 2036 /* 2037 * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so 2038 * the link-layer source address isn't forcibly overwritten. 2039 * (Should we ignore errors? Should we do this only if 2040 * we're open for writing?) 2041 * 2042 * XXX - I seem to remember some packet-sending bug in some 2043 * BSDs - check CVS log for "bpf.c"? 2044 */ 2045 if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 2046 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2047 "BIOCSHDRCMPLT: %s", pcap_strerror(errno)); 2048 status = PCAP_ERROR; 2049 goto bad; 2050 } 2051 #endif 2052 /* set timeout */ 2053 #ifdef HAVE_ZEROCOPY_BPF 2054 if (p->md.timeout != 0 && !p->md.zerocopy) { 2055 #else 2056 if (p->md.timeout) { 2057 #endif 2058 /* 2059 * XXX - is this seconds/nanoseconds in AIX? 2060 * (Treating it as such doesn't fix the timeout 2061 * problem described below.) 2062 * 2063 * XXX - Mac OS X 10.6 mishandles BIOCSRTIMEOUT in 2064 * 64-bit userland - it takes, as an argument, a 2065 * "struct BPF_TIMEVAL", which has 32-bit tv_sec 2066 * and tv_usec, rather than a "struct timeval". 2067 * 2068 * If this platform defines "struct BPF_TIMEVAL", 2069 * we check whether the structure size in BIOCSRTIMEOUT 2070 * is that of a "struct timeval" and, if not, we use 2071 * a "struct BPF_TIMEVAL" rather than a "struct timeval". 2072 * (That way, if the bug is fixed in a future release, 2073 * we will still do the right thing.) 2074 */ 2075 struct timeval to; 2076 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2077 struct BPF_TIMEVAL bpf_to; 2078 2079 if (IOCPARM_LEN(BIOCSRTIMEOUT) != sizeof(struct timeval)) { 2080 bpf_to.tv_sec = p->md.timeout / 1000; 2081 bpf_to.tv_usec = (p->md.timeout * 1000) % 1000000; 2082 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&bpf_to) < 0) { 2083 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2084 "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); 2085 status = PCAP_ERROR; 2086 goto bad; 2087 } 2088 } else { 2089 #endif 2090 to.tv_sec = p->md.timeout / 1000; 2091 to.tv_usec = (p->md.timeout * 1000) % 1000000; 2092 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) { 2093 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2094 "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); 2095 status = PCAP_ERROR; 2096 goto bad; 2097 } 2098 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2099 } 2100 #endif 2101 } 2102 2103 #ifdef _AIX 2104 #ifdef BIOCIMMEDIATE 2105 /* 2106 * Darren Reed notes that 2107 * 2108 * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the 2109 * timeout appears to be ignored and it waits until the buffer 2110 * is filled before returning. The result of not having it 2111 * set is almost worse than useless if your BPF filter 2112 * is reducing things to only a few packets (i.e. one every 2113 * second or so). 2114 * 2115 * so we turn BIOCIMMEDIATE mode on if this is AIX. 2116 * 2117 * We don't turn it on for other platforms, as that means we 2118 * get woken up for every packet, which may not be what we want; 2119 * in the Winter 1993 USENIX paper on BPF, they say: 2120 * 2121 * Since a process might want to look at every packet on a 2122 * network and the time between packets can be only a few 2123 * microseconds, it is not possible to do a read system call 2124 * per packet and BPF must collect the data from several 2125 * packets and return it as a unit when the monitoring 2126 * application does a read. 2127 * 2128 * which I infer is the reason for the timeout - it means we 2129 * wait that amount of time, in the hopes that more packets 2130 * will arrive and we'll get them all with one read. 2131 * 2132 * Setting BIOCIMMEDIATE mode on FreeBSD (and probably other 2133 * BSDs) causes the timeout to be ignored. 2134 * 2135 * On the other hand, some platforms (e.g., Linux) don't support 2136 * timeouts, they just hand stuff to you as soon as it arrives; 2137 * if that doesn't cause a problem on those platforms, it may 2138 * be OK to have BIOCIMMEDIATE mode on BSD as well. 2139 * 2140 * (Note, though, that applications may depend on the read 2141 * completing, even if no packets have arrived, when the timeout 2142 * expires, e.g. GUI applications that have to check for input 2143 * while waiting for packets to arrive; a non-zero timeout 2144 * prevents "select()" from working right on FreeBSD and 2145 * possibly other BSDs, as the timer doesn't start until a 2146 * "read()" is done, so the timer isn't in effect if the 2147 * application is blocked on a "select()", and the "select()" 2148 * doesn't get woken up for a BPF device until the buffer 2149 * fills up.) 2150 */ 2151 v = 1; 2152 if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) { 2153 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s", 2154 pcap_strerror(errno)); 2155 status = PCAP_ERROR; 2156 goto bad; 2157 } 2158 #endif /* BIOCIMMEDIATE */ 2159 #endif /* _AIX */ 2160 2161 if (p->opt.promisc) { 2162 /* set promiscuous mode, just warn if it fails */ 2163 if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) { 2164 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s", 2165 pcap_strerror(errno)); 2166 status = PCAP_WARNING_PROMISC_NOTSUP; 2167 } 2168 } 2169 2170 if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) { 2171 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s", 2172 pcap_strerror(errno)); 2173 status = PCAP_ERROR; 2174 goto bad; 2175 } 2176 p->bufsize = v; 2177 #ifdef HAVE_ZEROCOPY_BPF 2178 if (!p->md.zerocopy) { 2179 #endif 2180 p->buffer = (u_char *)malloc(p->bufsize); 2181 if (p->buffer == NULL) { 2182 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", 2183 pcap_strerror(errno)); 2184 status = PCAP_ERROR; 2185 goto bad; 2186 } 2187 #ifdef _AIX 2188 /* For some strange reason this seems to prevent the EFAULT 2189 * problems we have experienced from AIX BPF. */ 2190 memset(p->buffer, 0x0, p->bufsize); 2191 #endif 2192 #ifdef HAVE_ZEROCOPY_BPF 2193 } 2194 #endif 2195 2196 /* 2197 * If there's no filter program installed, there's 2198 * no indication to the kernel of what the snapshot 2199 * length should be, so no snapshotting is done. 2200 * 2201 * Therefore, when we open the device, we install 2202 * an "accept everything" filter with the specified 2203 * snapshot length. 2204 */ 2205 total_insn.code = (u_short)(BPF_RET | BPF_K); 2206 total_insn.jt = 0; 2207 total_insn.jf = 0; 2208 total_insn.k = p->snapshot; 2209 2210 total_prog.bf_len = 1; 2211 total_prog.bf_insns = &total_insn; 2212 if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) { 2213 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", 2214 pcap_strerror(errno)); 2215 status = PCAP_ERROR; 2216 goto bad; 2217 } 2218 2219 /* 2220 * On most BPF platforms, either you can do a "select()" or 2221 * "poll()" on a BPF file descriptor and it works correctly, 2222 * or you can do it and it will return "readable" if the 2223 * hold buffer is full but not if the timeout expires *and* 2224 * a non-blocking read will, if the hold buffer is empty 2225 * but the store buffer isn't empty, rotate the buffers 2226 * and return what packets are available. 2227 * 2228 * In the latter case, the fact that a non-blocking read 2229 * will give you the available packets means you can work 2230 * around the failure of "select()" and "poll()" to wake up 2231 * and return "readable" when the timeout expires by using 2232 * the timeout as the "select()" or "poll()" timeout, putting 2233 * the BPF descriptor into non-blocking mode, and read from 2234 * it regardless of whether "select()" reports it as readable 2235 * or not. 2236 * 2237 * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()" 2238 * won't wake up and return "readable" if the timer expires 2239 * and non-blocking reads return EWOULDBLOCK if the hold 2240 * buffer is empty, even if the store buffer is non-empty. 2241 * 2242 * This means the workaround in question won't work. 2243 * 2244 * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd" 2245 * to -1, which means "sorry, you can't use 'select()' or 'poll()' 2246 * here". On all other BPF platforms, we set it to the FD for 2247 * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking 2248 * read will, if the hold buffer is empty and the store buffer 2249 * isn't empty, rotate the buffers and return what packets are 2250 * there (and in sufficiently recent versions of OpenBSD 2251 * "select()" and "poll()" should work correctly). 2252 * 2253 * XXX - what about AIX? 2254 */ 2255 p->selectable_fd = p->fd; /* assume select() works until we know otherwise */ 2256 if (have_osinfo) { 2257 /* 2258 * We can check what OS this is. 2259 */ 2260 if (strcmp(osinfo.sysname, "FreeBSD") == 0) { 2261 if (strncmp(osinfo.release, "4.3-", 4) == 0 || 2262 strncmp(osinfo.release, "4.4-", 4) == 0) 2263 p->selectable_fd = -1; 2264 } 2265 } 2266 2267 p->read_op = pcap_read_bpf; 2268 p->inject_op = pcap_inject_bpf; 2269 p->setfilter_op = pcap_setfilter_bpf; 2270 p->setdirection_op = pcap_setdirection_bpf; 2271 p->set_datalink_op = pcap_set_datalink_bpf; 2272 p->getnonblock_op = pcap_getnonblock_bpf; 2273 p->setnonblock_op = pcap_setnonblock_bpf; 2274 p->stats_op = pcap_stats_bpf; 2275 p->cleanup_op = pcap_cleanup_bpf; 2276 2277 return (status); 2278 bad: 2279 pcap_cleanup_bpf(p); 2280 return (status); 2281 } 2282 2283 int 2284 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 2285 { 2286 #ifdef HAVE_DAG_API 2287 if (dag_platform_finddevs(alldevsp, errbuf) < 0) 2288 return (-1); 2289 #endif /* HAVE_DAG_API */ 2290 #ifdef HAVE_SNF_API 2291 if (snf_platform_finddevs(alldevsp, errbuf) < 0) 2292 return (-1); 2293 #endif /* HAVE_SNF_API */ 2294 2295 return (0); 2296 } 2297 2298 #ifdef HAVE_BSD_IEEE80211 2299 static int 2300 monitor_mode(pcap_t *p, int set) 2301 { 2302 int sock; 2303 struct ifmediareq req; 2304 int *media_list; 2305 int i; 2306 int can_do; 2307 struct ifreq ifr; 2308 2309 sock = socket(AF_INET, SOCK_DGRAM, 0); 2310 if (sock == -1) { 2311 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s", 2312 pcap_strerror(errno)); 2313 return (PCAP_ERROR); 2314 } 2315 2316 memset(&req, 0, sizeof req); 2317 strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name); 2318 2319 /* 2320 * Find out how many media types we have. 2321 */ 2322 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 2323 /* 2324 * Can't get the media types. 2325 */ 2326 switch (errno) { 2327 2328 case ENXIO: 2329 /* 2330 * There's no such device. 2331 */ 2332 close(sock); 2333 return (PCAP_ERROR_NO_SUCH_DEVICE); 2334 2335 case EINVAL: 2336 /* 2337 * Interface doesn't support SIOC{G,S}IFMEDIA. 2338 */ 2339 close(sock); 2340 return (PCAP_ERROR_RFMON_NOTSUP); 2341 2342 default: 2343 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2344 "SIOCGIFMEDIA 1: %s", pcap_strerror(errno)); 2345 close(sock); 2346 return (PCAP_ERROR); 2347 } 2348 } 2349 if (req.ifm_count == 0) { 2350 /* 2351 * No media types. 2352 */ 2353 close(sock); 2354 return (PCAP_ERROR_RFMON_NOTSUP); 2355 } 2356 2357 /* 2358 * Allocate a buffer to hold all the media types, and 2359 * get the media types. 2360 */ 2361 media_list = malloc(req.ifm_count * sizeof(int)); 2362 if (media_list == NULL) { 2363 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", 2364 pcap_strerror(errno)); 2365 close(sock); 2366 return (PCAP_ERROR); 2367 } 2368 req.ifm_ulist = media_list; 2369 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 2370 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s", 2371 pcap_strerror(errno)); 2372 free(media_list); 2373 close(sock); 2374 return (PCAP_ERROR); 2375 } 2376 2377 /* 2378 * Look for an 802.11 "automatic" media type. 2379 * We assume that all 802.11 adapters have that media type, 2380 * and that it will carry the monitor mode supported flag. 2381 */ 2382 can_do = 0; 2383 for (i = 0; i < req.ifm_count; i++) { 2384 if (IFM_TYPE(media_list[i]) == IFM_IEEE80211 2385 && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) { 2386 /* OK, does it do monitor mode? */ 2387 if (media_list[i] & IFM_IEEE80211_MONITOR) { 2388 can_do = 1; 2389 break; 2390 } 2391 } 2392 } 2393 free(media_list); 2394 if (!can_do) { 2395 /* 2396 * This adapter doesn't support monitor mode. 2397 */ 2398 close(sock); 2399 return (PCAP_ERROR_RFMON_NOTSUP); 2400 } 2401 2402 if (set) { 2403 /* 2404 * Don't just check whether we can enable monitor mode, 2405 * do so, if it's not already enabled. 2406 */ 2407 if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) { 2408 /* 2409 * Monitor mode isn't currently on, so turn it on, 2410 * and remember that we should turn it off when the 2411 * pcap_t is closed. 2412 */ 2413 2414 /* 2415 * If we haven't already done so, arrange to have 2416 * "pcap_close_all()" called when we exit. 2417 */ 2418 if (!pcap_do_addexit(p)) { 2419 /* 2420 * "atexit()" failed; don't put the interface 2421 * in monitor mode, just give up. 2422 */ 2423 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2424 "atexit failed"); 2425 close(sock); 2426 return (PCAP_ERROR); 2427 } 2428 memset(&ifr, 0, sizeof(ifr)); 2429 (void)strncpy(ifr.ifr_name, p->opt.source, 2430 sizeof(ifr.ifr_name)); 2431 ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR; 2432 if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) { 2433 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2434 "SIOCSIFMEDIA: %s", pcap_strerror(errno)); 2435 close(sock); 2436 return (PCAP_ERROR); 2437 } 2438 2439 p->md.must_do_on_close |= MUST_CLEAR_RFMON; 2440 2441 /* 2442 * Add this to the list of pcaps to close when we exit. 2443 */ 2444 pcap_add_to_pcaps_to_close(p); 2445 } 2446 } 2447 return (0); 2448 } 2449 #endif /* HAVE_BSD_IEEE80211 */ 2450 2451 #if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) 2452 /* 2453 * Check whether we have any 802.11 link-layer types; return the best 2454 * of the 802.11 link-layer types if we find one, and return -1 2455 * otherwise. 2456 * 2457 * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the 2458 * best 802.11 link-layer type; any of the other 802.11-plus-radio 2459 * headers are second-best; 802.11 with no radio information is 2460 * the least good. 2461 */ 2462 static int 2463 find_802_11(struct bpf_dltlist *bdlp) 2464 { 2465 int new_dlt; 2466 int i; 2467 2468 /* 2469 * Scan the list of DLT_ values, looking for 802.11 values, 2470 * and, if we find any, choose the best of them. 2471 */ 2472 new_dlt = -1; 2473 for (i = 0; i < bdlp->bfl_len; i++) { 2474 switch (bdlp->bfl_list[i]) { 2475 2476 case DLT_IEEE802_11: 2477 /* 2478 * 802.11, but no radio. 2479 * 2480 * Offer this, and select it as the new mode 2481 * unless we've already found an 802.11 2482 * header with radio information. 2483 */ 2484 if (new_dlt == -1) 2485 new_dlt = bdlp->bfl_list[i]; 2486 break; 2487 2488 case DLT_PRISM_HEADER: 2489 case DLT_AIRONET_HEADER: 2490 case DLT_IEEE802_11_RADIO_AVS: 2491 /* 2492 * 802.11 with radio, but not radiotap. 2493 * 2494 * Offer this, and select it as the new mode 2495 * unless we've already found the radiotap DLT_. 2496 */ 2497 if (new_dlt != DLT_IEEE802_11_RADIO) 2498 new_dlt = bdlp->bfl_list[i]; 2499 break; 2500 2501 case DLT_IEEE802_11_RADIO: 2502 /* 2503 * 802.11 with radiotap. 2504 * 2505 * Offer this, and select it as the new mode. 2506 */ 2507 new_dlt = bdlp->bfl_list[i]; 2508 break; 2509 2510 default: 2511 /* 2512 * Not 802.11. 2513 */ 2514 break; 2515 } 2516 } 2517 2518 return (new_dlt); 2519 } 2520 #endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */ 2521 2522 #if defined(__APPLE__) && defined(BIOCGDLTLIST) 2523 /* 2524 * Remove DLT_EN10MB from the list of DLT_ values, as we're in monitor mode, 2525 * and DLT_EN10MB isn't supported in monitor mode. 2526 */ 2527 static void 2528 remove_en(pcap_t *p) 2529 { 2530 int i, j; 2531 2532 /* 2533 * Scan the list of DLT_ values and discard DLT_EN10MB. 2534 */ 2535 j = 0; 2536 for (i = 0; i < p->dlt_count; i++) { 2537 switch (p->dlt_list[i]) { 2538 2539 case DLT_EN10MB: 2540 /* 2541 * Don't offer this one. 2542 */ 2543 continue; 2544 2545 default: 2546 /* 2547 * Just copy this mode over. 2548 */ 2549 break; 2550 } 2551 2552 /* 2553 * Copy this DLT_ value to its new position. 2554 */ 2555 p->dlt_list[j] = p->dlt_list[i]; 2556 j++; 2557 } 2558 2559 /* 2560 * Set the DLT_ count to the number of entries we copied. 2561 */ 2562 p->dlt_count = j; 2563 } 2564 2565 /* 2566 * Remove 802.11 link-layer types from the list of DLT_ values, as 2567 * we're not in monitor mode, and those DLT_ values will switch us 2568 * to monitor mode. 2569 */ 2570 static void 2571 remove_802_11(pcap_t *p) 2572 { 2573 int i, j; 2574 2575 /* 2576 * Scan the list of DLT_ values and discard 802.11 values. 2577 */ 2578 j = 0; 2579 for (i = 0; i < p->dlt_count; i++) { 2580 switch (p->dlt_list[i]) { 2581 2582 case DLT_IEEE802_11: 2583 case DLT_PRISM_HEADER: 2584 case DLT_AIRONET_HEADER: 2585 case DLT_IEEE802_11_RADIO: 2586 case DLT_IEEE802_11_RADIO_AVS: 2587 /* 2588 * 802.11. Don't offer this one. 2589 */ 2590 continue; 2591 2592 default: 2593 /* 2594 * Just copy this mode over. 2595 */ 2596 break; 2597 } 2598 2599 /* 2600 * Copy this DLT_ value to its new position. 2601 */ 2602 p->dlt_list[j] = p->dlt_list[i]; 2603 j++; 2604 } 2605 2606 /* 2607 * Set the DLT_ count to the number of entries we copied. 2608 */ 2609 p->dlt_count = j; 2610 } 2611 #endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */ 2612 2613 static int 2614 pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) 2615 { 2616 /* 2617 * Free any user-mode filter we might happen to have installed. 2618 */ 2619 pcap_freecode(&p->fcode); 2620 2621 /* 2622 * Try to install the kernel filter. 2623 */ 2624 if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) { 2625 /* 2626 * It worked. 2627 */ 2628 p->md.use_bpf = 1; /* filtering in the kernel */ 2629 2630 /* 2631 * Discard any previously-received packets, as they might 2632 * have passed whatever filter was formerly in effect, but 2633 * might not pass this filter (BIOCSETF discards packets 2634 * buffered in the kernel, so you can lose packets in any 2635 * case). 2636 */ 2637 p->cc = 0; 2638 return (0); 2639 } 2640 2641 /* 2642 * We failed. 2643 * 2644 * If it failed with EINVAL, that's probably because the program 2645 * is invalid or too big. Validate it ourselves; if we like it 2646 * (we currently allow backward branches, to support protochain), 2647 * run it in userland. (There's no notion of "too big" for 2648 * userland.) 2649 * 2650 * Otherwise, just give up. 2651 * XXX - if the copy of the program into the kernel failed, 2652 * we will get EINVAL rather than, say, EFAULT on at least 2653 * some kernels. 2654 */ 2655 if (errno != EINVAL) { 2656 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", 2657 pcap_strerror(errno)); 2658 return (-1); 2659 } 2660 2661 /* 2662 * install_bpf_program() validates the program. 2663 * 2664 * XXX - what if we already have a filter in the kernel? 2665 */ 2666 if (install_bpf_program(p, fp) < 0) 2667 return (-1); 2668 p->md.use_bpf = 0; /* filtering in userland */ 2669 return (0); 2670 } 2671 2672 /* 2673 * Set direction flag: Which packets do we accept on a forwarding 2674 * single device? IN, OUT or both? 2675 */ 2676 static int 2677 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d) 2678 { 2679 #if defined(BIOCSDIRECTION) 2680 u_int direction; 2681 2682 direction = (d == PCAP_D_IN) ? BPF_D_IN : 2683 ((d == PCAP_D_OUT) ? BPF_D_OUT : BPF_D_INOUT); 2684 if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) { 2685 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2686 "Cannot set direction to %s: %s", 2687 (d == PCAP_D_IN) ? "PCAP_D_IN" : 2688 ((d == PCAP_D_OUT) ? "PCAP_D_OUT" : "PCAP_D_INOUT"), 2689 strerror(errno)); 2690 return (-1); 2691 } 2692 return (0); 2693 #elif defined(BIOCSSEESENT) 2694 u_int seesent; 2695 2696 /* 2697 * We don't support PCAP_D_OUT. 2698 */ 2699 if (d == PCAP_D_OUT) { 2700 snprintf(p->errbuf, sizeof(p->errbuf), 2701 "Setting direction to PCAP_D_OUT is not supported on BPF"); 2702 return -1; 2703 } 2704 2705 seesent = (d == PCAP_D_INOUT); 2706 if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) { 2707 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2708 "Cannot set direction to %s: %s", 2709 (d == PCAP_D_INOUT) ? "PCAP_D_INOUT" : "PCAP_D_IN", 2710 strerror(errno)); 2711 return (-1); 2712 } 2713 return (0); 2714 #else 2715 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2716 "This system doesn't support BIOCSSEESENT, so the direction can't be set"); 2717 return (-1); 2718 #endif 2719 } 2720 2721 static int 2722 pcap_set_datalink_bpf(pcap_t *p, int dlt) 2723 { 2724 #ifdef BIOCSDLT 2725 if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) { 2726 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2727 "Cannot set DLT %d: %s", dlt, strerror(errno)); 2728 return (-1); 2729 } 2730 #endif 2731 return (0); 2732 } 2733