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_OS_PROTO_H 126 #include "os-proto.h" 127 #endif 128 129 /* 130 * Later versions of NetBSD stick padding in front of FDDI frames 131 * to align the IP header on a 4-byte boundary. 132 */ 133 #if defined(__NetBSD__) && __NetBSD_Version__ > 106000000 134 #define PCAP_FDDIPAD 3 135 #endif 136 137 /* 138 * Private data for capturing on BPF devices. 139 */ 140 struct pcap_bpf { 141 #ifdef PCAP_FDDIPAD 142 int fddipad; 143 #endif 144 145 #ifdef HAVE_ZEROCOPY_BPF 146 /* 147 * Zero-copy read buffer -- for zero-copy BPF. 'buffer' above will 148 * alternative between these two actual mmap'd buffers as required. 149 * As there is a header on the front size of the mmap'd buffer, only 150 * some of the buffer is exposed to libpcap as a whole via bufsize; 151 * zbufsize is the true size. zbuffer tracks the current zbuf 152 * assocated with buffer so that it can be used to decide which the 153 * next buffer to read will be. 154 */ 155 u_char *zbuf1, *zbuf2, *zbuffer; 156 u_int zbufsize; 157 u_int zerocopy; 158 u_int interrupted; 159 struct timespec firstsel; 160 /* 161 * If there's currently a buffer being actively processed, then it is 162 * referenced here; 'buffer' is also pointed at it, but offset by the 163 * size of the header. 164 */ 165 struct bpf_zbuf_header *bzh; 166 int nonblock; /* true if in nonblocking mode */ 167 #endif /* HAVE_ZEROCOPY_BPF */ 168 169 char *device; /* device name */ 170 int filtering_in_kernel; /* using kernel filter */ 171 int must_do_on_close; /* stuff we must do when we close */ 172 }; 173 174 /* 175 * Stuff to do when we close. 176 */ 177 #define MUST_CLEAR_RFMON 0x00000001 /* clear rfmon (monitor) mode */ 178 179 #ifdef BIOCGDLTLIST 180 # if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__) 181 #define HAVE_BSD_IEEE80211 182 # endif 183 184 # if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 185 static int find_802_11(struct bpf_dltlist *); 186 187 # ifdef HAVE_BSD_IEEE80211 188 static int monitor_mode(pcap_t *, int); 189 # endif 190 191 # if defined(__APPLE__) 192 static void remove_en(pcap_t *); 193 static void remove_802_11(pcap_t *); 194 # endif 195 196 # endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */ 197 198 #endif /* BIOCGDLTLIST */ 199 200 #if defined(sun) && defined(LIFNAMSIZ) && defined(lifr_zoneid) 201 #include <zone.h> 202 #endif 203 204 /* 205 * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably 206 * don't get DLT_DOCSIS defined. 207 */ 208 #ifndef DLT_DOCSIS 209 #define DLT_DOCSIS 143 210 #endif 211 212 /* 213 * On OS X, we don't even get any of the 802.11-plus-radio-header DLT_'s 214 * defined, even though some of them are used by various Airport drivers. 215 */ 216 #ifndef DLT_PRISM_HEADER 217 #define DLT_PRISM_HEADER 119 218 #endif 219 #ifndef DLT_AIRONET_HEADER 220 #define DLT_AIRONET_HEADER 120 221 #endif 222 #ifndef DLT_IEEE802_11_RADIO 223 #define DLT_IEEE802_11_RADIO 127 224 #endif 225 #ifndef DLT_IEEE802_11_RADIO_AVS 226 #define DLT_IEEE802_11_RADIO_AVS 163 227 #endif 228 229 static int pcap_can_set_rfmon_bpf(pcap_t *p); 230 static int pcap_activate_bpf(pcap_t *p); 231 static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp); 232 static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t); 233 static int pcap_set_datalink_bpf(pcap_t *p, int dlt); 234 235 /* 236 * For zerocopy bpf, the setnonblock/getnonblock routines need to modify 237 * pb->nonblock so we don't call select(2) if the pcap handle is in non- 238 * blocking mode. 239 */ 240 static int 241 pcap_getnonblock_bpf(pcap_t *p, char *errbuf) 242 { 243 #ifdef HAVE_ZEROCOPY_BPF 244 struct pcap_bpf *pb = p->priv; 245 246 if (pb->zerocopy) 247 return (pb->nonblock); 248 #endif 249 return (pcap_getnonblock_fd(p, errbuf)); 250 } 251 252 static int 253 pcap_setnonblock_bpf(pcap_t *p, int nonblock, char *errbuf) 254 { 255 #ifdef HAVE_ZEROCOPY_BPF 256 struct pcap_bpf *pb = p->priv; 257 258 if (pb->zerocopy) { 259 pb->nonblock = nonblock; 260 return (0); 261 } 262 #endif 263 return (pcap_setnonblock_fd(p, nonblock, errbuf)); 264 } 265 266 #ifdef HAVE_ZEROCOPY_BPF 267 /* 268 * Zero-copy BPF buffer routines to check for and acknowledge BPF data in 269 * shared memory buffers. 270 * 271 * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer, 272 * and set up p->buffer and cc to reflect one if available. Notice that if 273 * there was no prior buffer, we select zbuf1 as this will be the first 274 * buffer filled for a fresh BPF session. 275 */ 276 static int 277 pcap_next_zbuf_shm(pcap_t *p, int *cc) 278 { 279 struct pcap_bpf *pb = p->priv; 280 struct bpf_zbuf_header *bzh; 281 282 if (pb->zbuffer == pb->zbuf2 || pb->zbuffer == NULL) { 283 bzh = (struct bpf_zbuf_header *)pb->zbuf1; 284 if (bzh->bzh_user_gen != 285 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 286 pb->bzh = bzh; 287 pb->zbuffer = (u_char *)pb->zbuf1; 288 p->buffer = pb->zbuffer + sizeof(*bzh); 289 *cc = bzh->bzh_kernel_len; 290 return (1); 291 } 292 } else if (pb->zbuffer == pb->zbuf1) { 293 bzh = (struct bpf_zbuf_header *)pb->zbuf2; 294 if (bzh->bzh_user_gen != 295 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 296 pb->bzh = bzh; 297 pb->zbuffer = (u_char *)pb->zbuf2; 298 p->buffer = pb->zbuffer + sizeof(*bzh); 299 *cc = bzh->bzh_kernel_len; 300 return (1); 301 } 302 } 303 *cc = 0; 304 return (0); 305 } 306 307 /* 308 * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using 309 * select() for data or a timeout, and possibly force rotation of the buffer 310 * in the event we time out or are in immediate mode. Invoke the shared 311 * memory check before doing system calls in order to avoid doing avoidable 312 * work. 313 */ 314 static int 315 pcap_next_zbuf(pcap_t *p, int *cc) 316 { 317 struct pcap_bpf *pb = p->priv; 318 struct bpf_zbuf bz; 319 struct timeval tv; 320 struct timespec cur; 321 fd_set r_set; 322 int data, r; 323 int expire, tmout; 324 325 #define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000)) 326 /* 327 * Start out by seeing whether anything is waiting by checking the 328 * next shared memory buffer for data. 329 */ 330 data = pcap_next_zbuf_shm(p, cc); 331 if (data) 332 return (data); 333 /* 334 * If a previous sleep was interrupted due to signal delivery, make 335 * sure that the timeout gets adjusted accordingly. This requires 336 * that we analyze when the timeout should be been expired, and 337 * subtract the current time from that. If after this operation, 338 * our timeout is less then or equal to zero, handle it like a 339 * regular timeout. 340 */ 341 tmout = p->opt.timeout; 342 if (tmout) 343 (void) clock_gettime(CLOCK_MONOTONIC, &cur); 344 if (pb->interrupted && p->opt.timeout) { 345 expire = TSTOMILLI(&pb->firstsel) + p->opt.timeout; 346 tmout = expire - TSTOMILLI(&cur); 347 #undef TSTOMILLI 348 if (tmout <= 0) { 349 pb->interrupted = 0; 350 data = pcap_next_zbuf_shm(p, cc); 351 if (data) 352 return (data); 353 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 354 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 355 "BIOCROTZBUF: %s", strerror(errno)); 356 return (PCAP_ERROR); 357 } 358 return (pcap_next_zbuf_shm(p, cc)); 359 } 360 } 361 /* 362 * No data in the buffer, so must use select() to wait for data or 363 * the next timeout. Note that we only call select if the handle 364 * is in blocking mode. 365 */ 366 if (!pb->nonblock) { 367 FD_ZERO(&r_set); 368 FD_SET(p->fd, &r_set); 369 if (tmout != 0) { 370 tv.tv_sec = tmout / 1000; 371 tv.tv_usec = (tmout * 1000) % 1000000; 372 } 373 r = select(p->fd + 1, &r_set, NULL, NULL, 374 p->opt.timeout != 0 ? &tv : NULL); 375 if (r < 0 && errno == EINTR) { 376 if (!pb->interrupted && p->opt.timeout) { 377 pb->interrupted = 1; 378 pb->firstsel = cur; 379 } 380 return (0); 381 } else if (r < 0) { 382 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 383 "select: %s", strerror(errno)); 384 return (PCAP_ERROR); 385 } 386 } 387 pb->interrupted = 0; 388 /* 389 * Check again for data, which may exist now that we've either been 390 * woken up as a result of data or timed out. Try the "there's data" 391 * case first since it doesn't require a system call. 392 */ 393 data = pcap_next_zbuf_shm(p, cc); 394 if (data) 395 return (data); 396 /* 397 * Try forcing a buffer rotation to dislodge timed out or immediate 398 * data. 399 */ 400 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 401 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 402 "BIOCROTZBUF: %s", strerror(errno)); 403 return (PCAP_ERROR); 404 } 405 return (pcap_next_zbuf_shm(p, cc)); 406 } 407 408 /* 409 * Notify kernel that we are done with the buffer. We don't reset zbuffer so 410 * that we know which buffer to use next time around. 411 */ 412 static int 413 pcap_ack_zbuf(pcap_t *p) 414 { 415 struct pcap_bpf *pb = p->priv; 416 417 atomic_store_rel_int(&pb->bzh->bzh_user_gen, 418 pb->bzh->bzh_kernel_gen); 419 pb->bzh = NULL; 420 p->buffer = NULL; 421 return (0); 422 } 423 #endif /* HAVE_ZEROCOPY_BPF */ 424 425 pcap_t * 426 pcap_create_interface(const char *device, char *ebuf) 427 { 428 pcap_t *p; 429 430 p = pcap_create_common(device, ebuf, sizeof (struct pcap_bpf)); 431 if (p == NULL) 432 return (NULL); 433 434 p->activate_op = pcap_activate_bpf; 435 p->can_set_rfmon_op = pcap_can_set_rfmon_bpf; 436 return (p); 437 } 438 439 /* 440 * On success, returns a file descriptor for a BPF device. 441 * On failure, returns a PCAP_ERROR_ value, and sets p->errbuf. 442 */ 443 static int 444 bpf_open(pcap_t *p) 445 { 446 int fd; 447 #ifdef HAVE_CLONING_BPF 448 static const char device[] = "/dev/bpf"; 449 #else 450 int n = 0; 451 char device[sizeof "/dev/bpf0000000000"]; 452 #endif 453 454 #ifdef _AIX 455 /* 456 * Load the bpf driver, if it isn't already loaded, 457 * and create the BPF device entries, if they don't 458 * already exist. 459 */ 460 if (bpf_load(p->errbuf) == PCAP_ERROR) 461 return (PCAP_ERROR); 462 #endif 463 464 #ifdef HAVE_CLONING_BPF 465 if ((fd = open(device, O_RDWR)) == -1 && 466 (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) { 467 if (errno == EACCES) 468 fd = PCAP_ERROR_PERM_DENIED; 469 else 470 fd = PCAP_ERROR; 471 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 472 "(cannot open device) %s: %s", device, pcap_strerror(errno)); 473 } 474 #else 475 /* 476 * Go through all the minors and find one that isn't in use. 477 */ 478 do { 479 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); 480 /* 481 * Initially try a read/write open (to allow the inject 482 * method to work). If that fails due to permission 483 * issues, fall back to read-only. This allows a 484 * non-root user to be granted specific access to pcap 485 * capabilities via file permissions. 486 * 487 * XXX - we should have an API that has a flag that 488 * controls whether to open read-only or read-write, 489 * so that denial of permission to send (or inability 490 * to send, if sending packets isn't supported on 491 * the device in question) can be indicated at open 492 * time. 493 */ 494 fd = open(device, O_RDWR); 495 if (fd == -1 && errno == EACCES) 496 fd = open(device, O_RDONLY); 497 } while (fd < 0 && errno == EBUSY); 498 499 /* 500 * XXX better message for all minors used 501 */ 502 if (fd < 0) { 503 switch (errno) { 504 505 case ENOENT: 506 fd = PCAP_ERROR; 507 if (n == 1) { 508 /* 509 * /dev/bpf0 doesn't exist, which 510 * means we probably have no BPF 511 * devices. 512 */ 513 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 514 "(there are no BPF devices)"); 515 } else { 516 /* 517 * We got EBUSY on at least one 518 * BPF device, so we have BPF 519 * devices, but all the ones 520 * that exist are busy. 521 */ 522 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 523 "(all BPF devices are busy)"); 524 } 525 break; 526 527 case EACCES: 528 /* 529 * Got EACCES on the last device we tried, 530 * and EBUSY on all devices before that, 531 * if any. 532 */ 533 fd = PCAP_ERROR_PERM_DENIED; 534 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 535 "(cannot open BPF device) %s: %s", device, 536 pcap_strerror(errno)); 537 break; 538 539 default: 540 /* 541 * Some other problem. 542 */ 543 fd = PCAP_ERROR; 544 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 545 "(cannot open BPF device) %s: %s", device, 546 pcap_strerror(errno)); 547 break; 548 } 549 } 550 #endif 551 552 return (fd); 553 } 554 555 #ifdef BIOCGDLTLIST 556 static int 557 get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf) 558 { 559 memset(bdlp, 0, sizeof(*bdlp)); 560 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) { 561 u_int i; 562 int is_ethernet; 563 564 bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1)); 565 if (bdlp->bfl_list == NULL) { 566 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", 567 pcap_strerror(errno)); 568 return (PCAP_ERROR); 569 } 570 571 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) { 572 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, 573 "BIOCGDLTLIST: %s", pcap_strerror(errno)); 574 free(bdlp->bfl_list); 575 return (PCAP_ERROR); 576 } 577 578 /* 579 * OK, for real Ethernet devices, add DLT_DOCSIS to the 580 * list, so that an application can let you choose it, 581 * in case you're capturing DOCSIS traffic that a Cisco 582 * Cable Modem Termination System is putting out onto 583 * an Ethernet (it doesn't put an Ethernet header onto 584 * the wire, it puts raw DOCSIS frames out on the wire 585 * inside the low-level Ethernet framing). 586 * 587 * A "real Ethernet device" is defined here as a device 588 * that has a link-layer type of DLT_EN10MB and that has 589 * no alternate link-layer types; that's done to exclude 590 * 802.11 interfaces (which might or might not be the 591 * right thing to do, but I suspect it is - Ethernet <-> 592 * 802.11 bridges would probably badly mishandle frames 593 * that don't have Ethernet headers). 594 * 595 * On Solaris with BPF, Ethernet devices also offer 596 * DLT_IPNET, so we, if DLT_IPNET is defined, we don't 597 * treat it as an indication that the device isn't an 598 * Ethernet. 599 */ 600 if (v == DLT_EN10MB) { 601 is_ethernet = 1; 602 for (i = 0; i < bdlp->bfl_len; i++) { 603 if (bdlp->bfl_list[i] != DLT_EN10MB 604 #ifdef DLT_IPNET 605 && bdlp->bfl_list[i] != DLT_IPNET 606 #endif 607 ) { 608 is_ethernet = 0; 609 break; 610 } 611 } 612 if (is_ethernet) { 613 /* 614 * We reserved one more slot at the end of 615 * the list. 616 */ 617 bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS; 618 bdlp->bfl_len++; 619 } 620 } 621 } else { 622 /* 623 * EINVAL just means "we don't support this ioctl on 624 * this device"; don't treat it as an error. 625 */ 626 if (errno != EINVAL) { 627 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, 628 "BIOCGDLTLIST: %s", pcap_strerror(errno)); 629 return (PCAP_ERROR); 630 } 631 } 632 return (0); 633 } 634 #endif 635 636 static int 637 pcap_can_set_rfmon_bpf(pcap_t *p) 638 { 639 #if defined(__APPLE__) 640 struct utsname osinfo; 641 struct ifreq ifr; 642 int fd; 643 #ifdef BIOCGDLTLIST 644 struct bpf_dltlist bdl; 645 #endif 646 647 /* 648 * The joys of monitor mode on OS X. 649 * 650 * Prior to 10.4, it's not supported at all. 651 * 652 * In 10.4, if adapter enN supports monitor mode, there's a 653 * wltN adapter corresponding to it; you open it, instead of 654 * enN, to get monitor mode. You get whatever link-layer 655 * headers it supplies. 656 * 657 * In 10.5, and, we assume, later releases, if adapter enN 658 * supports monitor mode, it offers, among its selectable 659 * DLT_ values, values that let you get the 802.11 header; 660 * selecting one of those values puts the adapter into monitor 661 * mode (i.e., you can't get 802.11 headers except in monitor 662 * mode, and you can't get Ethernet headers in monitor mode). 663 */ 664 if (uname(&osinfo) == -1) { 665 /* 666 * Can't get the OS version; just say "no". 667 */ 668 return (0); 669 } 670 /* 671 * We assume osinfo.sysname is "Darwin", because 672 * __APPLE__ is defined. We just check the version. 673 */ 674 if (osinfo.release[0] < '8' && osinfo.release[1] == '.') { 675 /* 676 * 10.3 (Darwin 7.x) or earlier. 677 * Monitor mode not supported. 678 */ 679 return (0); 680 } 681 if (osinfo.release[0] == '8' && osinfo.release[1] == '.') { 682 /* 683 * 10.4 (Darwin 8.x). s/en/wlt/, and check 684 * whether the device exists. 685 */ 686 if (strncmp(p->opt.source, "en", 2) != 0) { 687 /* 688 * Not an enN device; no monitor mode. 689 */ 690 return (0); 691 } 692 fd = socket(AF_INET, SOCK_DGRAM, 0); 693 if (fd == -1) { 694 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 695 "socket: %s", pcap_strerror(errno)); 696 return (PCAP_ERROR); 697 } 698 strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name)); 699 strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name)); 700 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { 701 /* 702 * No such device? 703 */ 704 close(fd); 705 return (0); 706 } 707 close(fd); 708 return (1); 709 } 710 711 #ifdef BIOCGDLTLIST 712 /* 713 * Everything else is 10.5 or later; for those, 714 * we just open the enN device, and check whether 715 * we have any 802.11 devices. 716 * 717 * First, open a BPF device. 718 */ 719 fd = bpf_open(p); 720 if (fd < 0) 721 return (fd); /* fd is the appropriate error code */ 722 723 /* 724 * Now bind to the device. 725 */ 726 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); 727 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { 728 switch (errno) { 729 730 case ENXIO: 731 /* 732 * There's no such device. 733 */ 734 close(fd); 735 return (PCAP_ERROR_NO_SUCH_DEVICE); 736 737 case ENETDOWN: 738 /* 739 * Return a "network down" indication, so that 740 * the application can report that rather than 741 * saying we had a mysterious failure and 742 * suggest that they report a problem to the 743 * libpcap developers. 744 */ 745 close(fd); 746 return (PCAP_ERROR_IFACE_NOT_UP); 747 748 default: 749 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 750 "BIOCSETIF: %s: %s", 751 p->opt.source, pcap_strerror(errno)); 752 close(fd); 753 return (PCAP_ERROR); 754 } 755 } 756 757 /* 758 * We know the default link type -- now determine all the DLTs 759 * this interface supports. If this fails with EINVAL, it's 760 * not fatal; we just don't get to use the feature later. 761 * (We don't care about DLT_DOCSIS, so we pass DLT_NULL 762 * as the default DLT for this adapter.) 763 */ 764 if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) { 765 close(fd); 766 return (PCAP_ERROR); 767 } 768 if (find_802_11(&bdl) != -1) { 769 /* 770 * We have an 802.11 DLT, so we can set monitor mode. 771 */ 772 free(bdl.bfl_list); 773 close(fd); 774 return (1); 775 } 776 free(bdl.bfl_list); 777 #endif /* BIOCGDLTLIST */ 778 return (0); 779 #elif defined(HAVE_BSD_IEEE80211) 780 int ret; 781 782 ret = monitor_mode(p, 0); 783 if (ret == PCAP_ERROR_RFMON_NOTSUP) 784 return (0); /* not an error, just a "can't do" */ 785 if (ret == 0) 786 return (1); /* success */ 787 return (ret); 788 #else 789 return (0); 790 #endif 791 } 792 793 static int 794 pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) 795 { 796 struct bpf_stat s; 797 798 /* 799 * "ps_recv" counts packets handed to the filter, not packets 800 * that passed the filter. This includes packets later dropped 801 * because we ran out of buffer space. 802 * 803 * "ps_drop" counts packets dropped inside the BPF device 804 * because we ran out of buffer space. It doesn't count 805 * packets dropped by the interface driver. It counts 806 * only packets that passed the filter. 807 * 808 * Both statistics include packets not yet read from the kernel 809 * by libpcap, and thus not yet seen by the application. 810 */ 811 if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) { 812 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s", 813 pcap_strerror(errno)); 814 return (PCAP_ERROR); 815 } 816 817 ps->ps_recv = s.bs_recv; 818 ps->ps_drop = s.bs_drop; 819 ps->ps_ifdrop = 0; 820 return (0); 821 } 822 823 static int 824 pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 825 { 826 struct pcap_bpf *pb = p->priv; 827 int cc; 828 int n = 0; 829 register u_char *bp, *ep; 830 u_char *datap; 831 #ifdef PCAP_FDDIPAD 832 register int pad; 833 #endif 834 #ifdef HAVE_ZEROCOPY_BPF 835 int i; 836 #endif 837 838 again: 839 /* 840 * Has "pcap_breakloop()" been called? 841 */ 842 if (p->break_loop) { 843 /* 844 * Yes - clear the flag that indicates that it 845 * has, and return PCAP_ERROR_BREAK to indicate 846 * that we were told to break out of the loop. 847 */ 848 p->break_loop = 0; 849 return (PCAP_ERROR_BREAK); 850 } 851 cc = p->cc; 852 if (p->cc == 0) { 853 /* 854 * When reading without zero-copy from a file descriptor, we 855 * use a single buffer and return a length of data in the 856 * buffer. With zero-copy, we update the p->buffer pointer 857 * to point at whatever underlying buffer contains the next 858 * data and update cc to reflect the data found in the 859 * buffer. 860 */ 861 #ifdef HAVE_ZEROCOPY_BPF 862 if (pb->zerocopy) { 863 if (p->buffer != NULL) 864 pcap_ack_zbuf(p); 865 i = pcap_next_zbuf(p, &cc); 866 if (i == 0) 867 goto again; 868 if (i < 0) 869 return (PCAP_ERROR); 870 } else 871 #endif 872 { 873 cc = read(p->fd, (char *)p->buffer, p->bufsize); 874 } 875 if (cc < 0) { 876 /* Don't choke when we get ptraced */ 877 switch (errno) { 878 879 case EINTR: 880 goto again; 881 882 #ifdef _AIX 883 case EFAULT: 884 /* 885 * Sigh. More AIX wonderfulness. 886 * 887 * For some unknown reason the uiomove() 888 * operation in the bpf kernel extension 889 * used to copy the buffer into user 890 * space sometimes returns EFAULT. I have 891 * no idea why this is the case given that 892 * a kernel debugger shows the user buffer 893 * is correct. This problem appears to 894 * be mostly mitigated by the memset of 895 * the buffer before it is first used. 896 * Very strange.... Shaun Clowes 897 * 898 * In any case this means that we shouldn't 899 * treat EFAULT as a fatal error; as we 900 * don't have an API for returning 901 * a "some packets were dropped since 902 * the last packet you saw" indication, 903 * we just ignore EFAULT and keep reading. 904 */ 905 goto again; 906 #endif 907 908 case EWOULDBLOCK: 909 return (0); 910 911 case ENXIO: 912 /* 913 * The device on which we're capturing 914 * went away. 915 * 916 * XXX - we should really return 917 * PCAP_ERROR_IFACE_NOT_UP, but 918 * pcap_dispatch() etc. aren't 919 * defined to retur that. 920 */ 921 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 922 "The interface went down"); 923 return (PCAP_ERROR); 924 925 #if defined(sun) && !defined(BSD) && !defined(__svr4__) && !defined(__SVR4) 926 /* 927 * Due to a SunOS bug, after 2^31 bytes, the kernel 928 * file offset overflows and read fails with EINVAL. 929 * The lseek() to 0 will fix things. 930 */ 931 case EINVAL: 932 if (lseek(p->fd, 0L, SEEK_CUR) + 933 p->bufsize < 0) { 934 (void)lseek(p->fd, 0L, SEEK_SET); 935 goto again; 936 } 937 /* fall through */ 938 #endif 939 } 940 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s", 941 pcap_strerror(errno)); 942 return (PCAP_ERROR); 943 } 944 bp = p->buffer; 945 } else 946 bp = p->bp; 947 948 /* 949 * Loop through each packet. 950 */ 951 #define bhp ((struct bpf_hdr *)bp) 952 ep = bp + cc; 953 #ifdef PCAP_FDDIPAD 954 pad = p->fddipad; 955 #endif 956 while (bp < ep) { 957 register int caplen, hdrlen; 958 959 /* 960 * Has "pcap_breakloop()" been called? 961 * If so, return immediately - if we haven't read any 962 * packets, clear the flag and return PCAP_ERROR_BREAK 963 * to indicate that we were told to break out of the loop, 964 * otherwise leave the flag set, so that the *next* call 965 * will break out of the loop without having read any 966 * packets, and return the number of packets we've 967 * processed so far. 968 */ 969 if (p->break_loop) { 970 p->bp = bp; 971 p->cc = ep - bp; 972 /* 973 * ep is set based on the return value of read(), 974 * but read() from a BPF device doesn't necessarily 975 * return a value that's a multiple of the alignment 976 * value for BPF_WORDALIGN(). However, whenever we 977 * increment bp, we round up the increment value by 978 * a value rounded up by BPF_WORDALIGN(), so we 979 * could increment bp past ep after processing the 980 * last packet in the buffer. 981 * 982 * We treat ep < bp as an indication that this 983 * happened, and just set p->cc to 0. 984 */ 985 if (p->cc < 0) 986 p->cc = 0; 987 if (n == 0) { 988 p->break_loop = 0; 989 return (PCAP_ERROR_BREAK); 990 } else 991 return (n); 992 } 993 994 caplen = bhp->bh_caplen; 995 hdrlen = bhp->bh_hdrlen; 996 datap = bp + hdrlen; 997 /* 998 * Short-circuit evaluation: if using BPF filter 999 * in kernel, no need to do it now - we already know 1000 * the packet passed the filter. 1001 * 1002 #ifdef PCAP_FDDIPAD 1003 * Note: the filter code was generated assuming 1004 * that p->fddipad was the amount of padding 1005 * before the header, as that's what's required 1006 * in the kernel, so we run the filter before 1007 * skipping that padding. 1008 #endif 1009 */ 1010 if (pb->filtering_in_kernel || 1011 bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) { 1012 struct pcap_pkthdr pkthdr; 1013 1014 pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec; 1015 #ifdef _AIX 1016 /* 1017 * AIX's BPF returns seconds/nanoseconds time 1018 * stamps, not seconds/microseconds time stamps. 1019 */ 1020 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000; 1021 #else 1022 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec; 1023 #endif 1024 #ifdef PCAP_FDDIPAD 1025 if (caplen > pad) 1026 pkthdr.caplen = caplen - pad; 1027 else 1028 pkthdr.caplen = 0; 1029 if (bhp->bh_datalen > pad) 1030 pkthdr.len = bhp->bh_datalen - pad; 1031 else 1032 pkthdr.len = 0; 1033 datap += pad; 1034 #else 1035 pkthdr.caplen = caplen; 1036 pkthdr.len = bhp->bh_datalen; 1037 #endif 1038 (*callback)(user, &pkthdr, datap); 1039 bp += BPF_WORDALIGN(caplen + hdrlen); 1040 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) { 1041 p->bp = bp; 1042 p->cc = ep - bp; 1043 /* 1044 * See comment above about p->cc < 0. 1045 */ 1046 if (p->cc < 0) 1047 p->cc = 0; 1048 return (n); 1049 } 1050 } else { 1051 /* 1052 * Skip this packet. 1053 */ 1054 bp += BPF_WORDALIGN(caplen + hdrlen); 1055 } 1056 } 1057 #undef bhp 1058 p->cc = 0; 1059 return (n); 1060 } 1061 1062 static int 1063 pcap_inject_bpf(pcap_t *p, const void *buf, size_t size) 1064 { 1065 int ret; 1066 1067 ret = write(p->fd, buf, size); 1068 #ifdef __APPLE__ 1069 if (ret == -1 && errno == EAFNOSUPPORT) { 1070 /* 1071 * In Mac OS X, there's a bug wherein setting the 1072 * BIOCSHDRCMPLT flag causes writes to fail; see, 1073 * for example: 1074 * 1075 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch 1076 * 1077 * So, if, on OS X, we get EAFNOSUPPORT from the write, we 1078 * assume it's due to that bug, and turn off that flag 1079 * and try again. If we succeed, it either means that 1080 * somebody applied the fix from that URL, or other patches 1081 * for that bug from 1082 * 1083 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/ 1084 * 1085 * and are running a Darwin kernel with those fixes, or 1086 * that Apple fixed the problem in some OS X release. 1087 */ 1088 u_int spoof_eth_src = 0; 1089 1090 if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 1091 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1092 "send: can't turn off BIOCSHDRCMPLT: %s", 1093 pcap_strerror(errno)); 1094 return (PCAP_ERROR); 1095 } 1096 1097 /* 1098 * Now try the write again. 1099 */ 1100 ret = write(p->fd, buf, size); 1101 } 1102 #endif /* __APPLE__ */ 1103 if (ret == -1) { 1104 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 1105 pcap_strerror(errno)); 1106 return (PCAP_ERROR); 1107 } 1108 return (ret); 1109 } 1110 1111 #ifdef _AIX 1112 static int 1113 bpf_odminit(char *errbuf) 1114 { 1115 char *errstr; 1116 1117 if (odm_initialize() == -1) { 1118 if (odm_err_msg(odmerrno, &errstr) == -1) 1119 errstr = "Unknown error"; 1120 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1121 "bpf_load: odm_initialize failed: %s", 1122 errstr); 1123 return (PCAP_ERROR); 1124 } 1125 1126 if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) { 1127 if (odm_err_msg(odmerrno, &errstr) == -1) 1128 errstr = "Unknown error"; 1129 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1130 "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s", 1131 errstr); 1132 (void)odm_terminate(); 1133 return (PCAP_ERROR); 1134 } 1135 1136 return (0); 1137 } 1138 1139 static int 1140 bpf_odmcleanup(char *errbuf) 1141 { 1142 char *errstr; 1143 1144 if (odm_unlock(odmlockid) == -1) { 1145 if (errbuf != NULL) { 1146 if (odm_err_msg(odmerrno, &errstr) == -1) 1147 errstr = "Unknown error"; 1148 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1149 "bpf_load: odm_unlock failed: %s", 1150 errstr); 1151 } 1152 return (PCAP_ERROR); 1153 } 1154 1155 if (odm_terminate() == -1) { 1156 if (errbuf != NULL) { 1157 if (odm_err_msg(odmerrno, &errstr) == -1) 1158 errstr = "Unknown error"; 1159 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1160 "bpf_load: odm_terminate failed: %s", 1161 errstr); 1162 } 1163 return (PCAP_ERROR); 1164 } 1165 1166 return (0); 1167 } 1168 1169 static int 1170 bpf_load(char *errbuf) 1171 { 1172 long major; 1173 int *minors; 1174 int numminors, i, rc; 1175 char buf[1024]; 1176 struct stat sbuf; 1177 struct bpf_config cfg_bpf; 1178 struct cfg_load cfg_ld; 1179 struct cfg_kmod cfg_km; 1180 1181 /* 1182 * This is very very close to what happens in the real implementation 1183 * but I've fixed some (unlikely) bug situations. 1184 */ 1185 if (bpfloadedflag) 1186 return (0); 1187 1188 if (bpf_odminit(errbuf) == PCAP_ERROR) 1189 return (PCAP_ERROR); 1190 1191 major = genmajor(BPF_NAME); 1192 if (major == -1) { 1193 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1194 "bpf_load: genmajor failed: %s", pcap_strerror(errno)); 1195 (void)bpf_odmcleanup(NULL); 1196 return (PCAP_ERROR); 1197 } 1198 1199 minors = getminor(major, &numminors, BPF_NAME); 1200 if (!minors) { 1201 minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1); 1202 if (!minors) { 1203 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1204 "bpf_load: genminor failed: %s", 1205 pcap_strerror(errno)); 1206 (void)bpf_odmcleanup(NULL); 1207 return (PCAP_ERROR); 1208 } 1209 } 1210 1211 if (bpf_odmcleanup(errbuf) == PCAP_ERROR) 1212 return (PCAP_ERROR); 1213 1214 rc = stat(BPF_NODE "0", &sbuf); 1215 if (rc == -1 && errno != ENOENT) { 1216 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1217 "bpf_load: can't stat %s: %s", 1218 BPF_NODE "0", pcap_strerror(errno)); 1219 return (PCAP_ERROR); 1220 } 1221 1222 if (rc == -1 || getmajor(sbuf.st_rdev) != major) { 1223 for (i = 0; i < BPF_MINORS; i++) { 1224 sprintf(buf, "%s%d", BPF_NODE, i); 1225 unlink(buf); 1226 if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) { 1227 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1228 "bpf_load: can't mknod %s: %s", 1229 buf, pcap_strerror(errno)); 1230 return (PCAP_ERROR); 1231 } 1232 } 1233 } 1234 1235 /* Check if the driver is loaded */ 1236 memset(&cfg_ld, 0x0, sizeof(cfg_ld)); 1237 cfg_ld.path = buf; 1238 sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME); 1239 if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) || 1240 (cfg_ld.kmid == 0)) { 1241 /* Driver isn't loaded, load it now */ 1242 if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) { 1243 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1244 "bpf_load: could not load driver: %s", 1245 strerror(errno)); 1246 return (PCAP_ERROR); 1247 } 1248 } 1249 1250 /* Configure the driver */ 1251 cfg_km.cmd = CFG_INIT; 1252 cfg_km.kmid = cfg_ld.kmid; 1253 cfg_km.mdilen = sizeof(cfg_bpf); 1254 cfg_km.mdiptr = (void *)&cfg_bpf; 1255 for (i = 0; i < BPF_MINORS; i++) { 1256 cfg_bpf.devno = domakedev(major, i); 1257 if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) { 1258 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1259 "bpf_load: could not configure driver: %s", 1260 strerror(errno)); 1261 return (PCAP_ERROR); 1262 } 1263 } 1264 1265 bpfloadedflag = 1; 1266 1267 return (0); 1268 } 1269 #endif 1270 1271 /* 1272 * Turn off rfmon mode if necessary. 1273 */ 1274 static void 1275 pcap_cleanup_bpf(pcap_t *p) 1276 { 1277 struct pcap_bpf *pb = p->priv; 1278 #ifdef HAVE_BSD_IEEE80211 1279 int sock; 1280 struct ifmediareq req; 1281 struct ifreq ifr; 1282 #endif 1283 1284 if (pb->must_do_on_close != 0) { 1285 /* 1286 * There's something we have to do when closing this 1287 * pcap_t. 1288 */ 1289 #ifdef HAVE_BSD_IEEE80211 1290 if (pb->must_do_on_close & MUST_CLEAR_RFMON) { 1291 /* 1292 * We put the interface into rfmon mode; 1293 * take it out of rfmon mode. 1294 * 1295 * XXX - if somebody else wants it in rfmon 1296 * mode, this code cannot know that, so it'll take 1297 * it out of rfmon mode. 1298 */ 1299 sock = socket(AF_INET, SOCK_DGRAM, 0); 1300 if (sock == -1) { 1301 fprintf(stderr, 1302 "Can't restore interface flags (socket() failed: %s).\n" 1303 "Please adjust manually.\n", 1304 strerror(errno)); 1305 } else { 1306 memset(&req, 0, sizeof(req)); 1307 strncpy(req.ifm_name, pb->device, 1308 sizeof(req.ifm_name)); 1309 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 1310 fprintf(stderr, 1311 "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n" 1312 "Please adjust manually.\n", 1313 strerror(errno)); 1314 } else { 1315 if (req.ifm_current & IFM_IEEE80211_MONITOR) { 1316 /* 1317 * Rfmon mode is currently on; 1318 * turn it off. 1319 */ 1320 memset(&ifr, 0, sizeof(ifr)); 1321 (void)strncpy(ifr.ifr_name, 1322 pb->device, 1323 sizeof(ifr.ifr_name)); 1324 ifr.ifr_media = 1325 req.ifm_current & ~IFM_IEEE80211_MONITOR; 1326 if (ioctl(sock, SIOCSIFMEDIA, 1327 &ifr) == -1) { 1328 fprintf(stderr, 1329 "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n" 1330 "Please adjust manually.\n", 1331 strerror(errno)); 1332 } 1333 } 1334 } 1335 close(sock); 1336 } 1337 } 1338 #endif /* HAVE_BSD_IEEE80211 */ 1339 1340 /* 1341 * Take this pcap out of the list of pcaps for which we 1342 * have to take the interface out of some mode. 1343 */ 1344 pcap_remove_from_pcaps_to_close(p); 1345 pb->must_do_on_close = 0; 1346 } 1347 1348 #ifdef HAVE_ZEROCOPY_BPF 1349 if (pb->zerocopy) { 1350 /* 1351 * Delete the mappings. Note that p->buffer gets 1352 * initialized to one of the mmapped regions in 1353 * this case, so do not try and free it directly; 1354 * null it out so that pcap_cleanup_live_common() 1355 * doesn't try to free it. 1356 */ 1357 if (pb->zbuf1 != MAP_FAILED && pb->zbuf1 != NULL) 1358 (void) munmap(pb->zbuf1, pb->zbufsize); 1359 if (pb->zbuf2 != MAP_FAILED && pb->zbuf2 != NULL) 1360 (void) munmap(pb->zbuf2, pb->zbufsize); 1361 p->buffer = NULL; 1362 } 1363 #endif 1364 if (pb->device != NULL) { 1365 free(pb->device); 1366 pb->device = NULL; 1367 } 1368 pcap_cleanup_live_common(p); 1369 } 1370 1371 static int 1372 check_setif_failure(pcap_t *p, int error) 1373 { 1374 #ifdef __APPLE__ 1375 int fd; 1376 struct ifreq ifr; 1377 int err; 1378 #endif 1379 1380 if (error == ENXIO) { 1381 /* 1382 * No such device exists. 1383 */ 1384 #ifdef __APPLE__ 1385 if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) { 1386 /* 1387 * Monitor mode was requested, and we're trying 1388 * to open a "wltN" device. Assume that this 1389 * is 10.4 and that we were asked to open an 1390 * "enN" device; if that device exists, return 1391 * "monitor mode not supported on the device". 1392 */ 1393 fd = socket(AF_INET, SOCK_DGRAM, 0); 1394 if (fd != -1) { 1395 strlcpy(ifr.ifr_name, "en", 1396 sizeof(ifr.ifr_name)); 1397 strlcat(ifr.ifr_name, p->opt.source + 3, 1398 sizeof(ifr.ifr_name)); 1399 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { 1400 /* 1401 * We assume this failed because 1402 * the underlying device doesn't 1403 * exist. 1404 */ 1405 err = PCAP_ERROR_NO_SUCH_DEVICE; 1406 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1407 "SIOCGIFFLAGS on %s failed: %s", 1408 ifr.ifr_name, pcap_strerror(errno)); 1409 } else { 1410 /* 1411 * The underlying "enN" device 1412 * exists, but there's no 1413 * corresponding "wltN" device; 1414 * that means that the "enN" 1415 * device doesn't support 1416 * monitor mode, probably because 1417 * it's an Ethernet device rather 1418 * than a wireless device. 1419 */ 1420 err = PCAP_ERROR_RFMON_NOTSUP; 1421 } 1422 close(fd); 1423 } else { 1424 /* 1425 * We can't find out whether there's 1426 * an underlying "enN" device, so 1427 * just report "no such device". 1428 */ 1429 err = PCAP_ERROR_NO_SUCH_DEVICE; 1430 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1431 "socket() failed: %s", 1432 pcap_strerror(errno)); 1433 } 1434 return (err); 1435 } 1436 #endif 1437 /* 1438 * No such device. 1439 */ 1440 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF failed: %s", 1441 pcap_strerror(errno)); 1442 return (PCAP_ERROR_NO_SUCH_DEVICE); 1443 } else if (errno == ENETDOWN) { 1444 /* 1445 * Return a "network down" indication, so that 1446 * the application can report that rather than 1447 * saying we had a mysterious failure and 1448 * suggest that they report a problem to the 1449 * libpcap developers. 1450 */ 1451 return (PCAP_ERROR_IFACE_NOT_UP); 1452 } else { 1453 /* 1454 * Some other error; fill in the error string, and 1455 * return PCAP_ERROR. 1456 */ 1457 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", 1458 p->opt.source, pcap_strerror(errno)); 1459 return (PCAP_ERROR); 1460 } 1461 } 1462 1463 /* 1464 * Default capture buffer size. 1465 * 32K isn't very much for modern machines with fast networks; we 1466 * pick .5M, as that's the maximum on at least some systems with BPF. 1467 * 1468 * However, on AIX 3.5, the larger buffer sized caused unrecoverable 1469 * read failures under stress, so we leave it as 32K; yet another 1470 * place where AIX's BPF is broken. 1471 */ 1472 #ifdef _AIX 1473 #define DEFAULT_BUFSIZE 32768 1474 #else 1475 #define DEFAULT_BUFSIZE 524288 1476 #endif 1477 1478 static int 1479 pcap_activate_bpf(pcap_t *p) 1480 { 1481 struct pcap_bpf *pb = p->priv; 1482 int status = 0; 1483 int fd; 1484 #ifdef LIFNAMSIZ 1485 char *zonesep; 1486 struct lifreq ifr; 1487 char *ifrname = ifr.lifr_name; 1488 const size_t ifnamsiz = sizeof(ifr.lifr_name); 1489 #else 1490 struct ifreq ifr; 1491 char *ifrname = ifr.ifr_name; 1492 const size_t ifnamsiz = sizeof(ifr.ifr_name); 1493 #endif 1494 struct bpf_version bv; 1495 #ifdef __APPLE__ 1496 int sockfd; 1497 char *wltdev = NULL; 1498 #endif 1499 #ifdef BIOCGDLTLIST 1500 struct bpf_dltlist bdl; 1501 #if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 1502 int new_dlt; 1503 #endif 1504 #endif /* BIOCGDLTLIST */ 1505 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 1506 u_int spoof_eth_src = 1; 1507 #endif 1508 u_int v; 1509 struct bpf_insn total_insn; 1510 struct bpf_program total_prog; 1511 struct utsname osinfo; 1512 int have_osinfo = 0; 1513 #ifdef HAVE_ZEROCOPY_BPF 1514 struct bpf_zbuf bz; 1515 u_int bufmode, zbufmax; 1516 #endif 1517 1518 fd = bpf_open(p); 1519 if (fd < 0) { 1520 status = fd; 1521 goto bad; 1522 } 1523 1524 p->fd = fd; 1525 1526 if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) { 1527 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s", 1528 pcap_strerror(errno)); 1529 status = PCAP_ERROR; 1530 goto bad; 1531 } 1532 if (bv.bv_major != BPF_MAJOR_VERSION || 1533 bv.bv_minor < BPF_MINOR_VERSION) { 1534 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1535 "kernel bpf filter out of date"); 1536 status = PCAP_ERROR; 1537 goto bad; 1538 } 1539 1540 #if defined(LIFNAMSIZ) && defined(ZONENAME_MAX) && defined(lifr_zoneid) 1541 /* 1542 * Check if the given source network device has a '/' separated 1543 * zonename prefix string. The zonename prefixed source device 1544 * can be used by libpcap consumers to capture network traffic 1545 * in non-global zones from the global zone on Solaris 11 and 1546 * above. If the zonename prefix is present then we strip the 1547 * prefix and pass the zone ID as part of lifr_zoneid. 1548 */ 1549 if ((zonesep = strchr(p->opt.source, '/')) != NULL) { 1550 char zonename[ZONENAME_MAX]; 1551 int znamelen; 1552 char *lnamep; 1553 1554 znamelen = zonesep - p->opt.source; 1555 (void) strlcpy(zonename, p->opt.source, znamelen + 1); 1556 lnamep = strdup(zonesep + 1); 1557 ifr.lifr_zoneid = getzoneidbyname(zonename); 1558 free(p->opt.source); 1559 p->opt.source = lnamep; 1560 } 1561 #endif 1562 1563 pb->device = strdup(p->opt.source); 1564 if (pb->device == NULL) { 1565 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s", 1566 pcap_strerror(errno)); 1567 status = PCAP_ERROR; 1568 goto bad; 1569 } 1570 1571 /* 1572 * Attempt to find out the version of the OS on which we're running. 1573 */ 1574 if (uname(&osinfo) == 0) 1575 have_osinfo = 1; 1576 1577 #ifdef __APPLE__ 1578 /* 1579 * See comment in pcap_can_set_rfmon_bpf() for an explanation 1580 * of why we check the version number. 1581 */ 1582 if (p->opt.rfmon) { 1583 if (have_osinfo) { 1584 /* 1585 * We assume osinfo.sysname is "Darwin", because 1586 * __APPLE__ is defined. We just check the version. 1587 */ 1588 if (osinfo.release[0] < '8' && 1589 osinfo.release[1] == '.') { 1590 /* 1591 * 10.3 (Darwin 7.x) or earlier. 1592 */ 1593 status = PCAP_ERROR_RFMON_NOTSUP; 1594 goto bad; 1595 } 1596 if (osinfo.release[0] == '8' && 1597 osinfo.release[1] == '.') { 1598 /* 1599 * 10.4 (Darwin 8.x). s/en/wlt/ 1600 */ 1601 if (strncmp(p->opt.source, "en", 2) != 0) { 1602 /* 1603 * Not an enN device; check 1604 * whether the device even exists. 1605 */ 1606 sockfd = socket(AF_INET, SOCK_DGRAM, 0); 1607 if (sockfd != -1) { 1608 strlcpy(ifrname, 1609 p->opt.source, ifnamsiz); 1610 if (ioctl(sockfd, SIOCGIFFLAGS, 1611 (char *)&ifr) < 0) { 1612 /* 1613 * We assume this 1614 * failed because 1615 * the underlying 1616 * device doesn't 1617 * exist. 1618 */ 1619 status = PCAP_ERROR_NO_SUCH_DEVICE; 1620 snprintf(p->errbuf, 1621 PCAP_ERRBUF_SIZE, 1622 "SIOCGIFFLAGS failed: %s", 1623 pcap_strerror(errno)); 1624 } else 1625 status = PCAP_ERROR_RFMON_NOTSUP; 1626 close(sockfd); 1627 } else { 1628 /* 1629 * We can't find out whether 1630 * the device exists, so just 1631 * report "no such device". 1632 */ 1633 status = PCAP_ERROR_NO_SUCH_DEVICE; 1634 snprintf(p->errbuf, 1635 PCAP_ERRBUF_SIZE, 1636 "socket() failed: %s", 1637 pcap_strerror(errno)); 1638 } 1639 goto bad; 1640 } 1641 wltdev = malloc(strlen(p->opt.source) + 2); 1642 if (wltdev == NULL) { 1643 (void)snprintf(p->errbuf, 1644 PCAP_ERRBUF_SIZE, "malloc: %s", 1645 pcap_strerror(errno)); 1646 status = PCAP_ERROR; 1647 goto bad; 1648 } 1649 strcpy(wltdev, "wlt"); 1650 strcat(wltdev, p->opt.source + 2); 1651 free(p->opt.source); 1652 p->opt.source = wltdev; 1653 } 1654 /* 1655 * Everything else is 10.5 or later; for those, 1656 * we just open the enN device, and set the DLT. 1657 */ 1658 } 1659 } 1660 #endif /* __APPLE__ */ 1661 #ifdef HAVE_ZEROCOPY_BPF 1662 /* 1663 * If the BPF extension to set buffer mode is present, try setting 1664 * the mode to zero-copy. If that fails, use regular buffering. If 1665 * it succeeds but other setup fails, return an error to the user. 1666 */ 1667 bufmode = BPF_BUFMODE_ZBUF; 1668 if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) { 1669 /* 1670 * We have zerocopy BPF; use it. 1671 */ 1672 pb->zerocopy = 1; 1673 1674 /* 1675 * How to pick a buffer size: first, query the maximum buffer 1676 * size supported by zero-copy. This also lets us quickly 1677 * determine whether the kernel generally supports zero-copy. 1678 * Then, if a buffer size was specified, use that, otherwise 1679 * query the default buffer size, which reflects kernel 1680 * policy for a desired default. Round to the nearest page 1681 * size. 1682 */ 1683 if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) { 1684 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s", 1685 pcap_strerror(errno)); 1686 goto bad; 1687 } 1688 1689 if (p->opt.buffer_size != 0) { 1690 /* 1691 * A buffer size was explicitly specified; use it. 1692 */ 1693 v = p->opt.buffer_size; 1694 } else { 1695 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 1696 v < DEFAULT_BUFSIZE) 1697 v = DEFAULT_BUFSIZE; 1698 } 1699 #ifndef roundup 1700 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 1701 #endif 1702 pb->zbufsize = roundup(v, getpagesize()); 1703 if (pb->zbufsize > zbufmax) 1704 pb->zbufsize = zbufmax; 1705 pb->zbuf1 = mmap(NULL, pb->zbufsize, PROT_READ | PROT_WRITE, 1706 MAP_ANON, -1, 0); 1707 pb->zbuf2 = mmap(NULL, pb->zbufsize, PROT_READ | PROT_WRITE, 1708 MAP_ANON, -1, 0); 1709 if (pb->zbuf1 == MAP_FAILED || pb->zbuf2 == MAP_FAILED) { 1710 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s", 1711 pcap_strerror(errno)); 1712 goto bad; 1713 } 1714 memset(&bz, 0, sizeof(bz)); /* bzero() deprecated, replaced with memset() */ 1715 bz.bz_bufa = pb->zbuf1; 1716 bz.bz_bufb = pb->zbuf2; 1717 bz.bz_buflen = pb->zbufsize; 1718 if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) { 1719 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s", 1720 pcap_strerror(errno)); 1721 goto bad; 1722 } 1723 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1724 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { 1725 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", 1726 p->opt.source, pcap_strerror(errno)); 1727 goto bad; 1728 } 1729 v = pb->zbufsize - sizeof(struct bpf_zbuf_header); 1730 } else 1731 #endif 1732 { 1733 /* 1734 * We don't have zerocopy BPF. 1735 * Set the buffer size. 1736 */ 1737 if (p->opt.buffer_size != 0) { 1738 /* 1739 * A buffer size was explicitly specified; use it. 1740 */ 1741 if (ioctl(fd, BIOCSBLEN, 1742 (caddr_t)&p->opt.buffer_size) < 0) { 1743 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1744 "BIOCSBLEN: %s: %s", p->opt.source, 1745 pcap_strerror(errno)); 1746 status = PCAP_ERROR; 1747 goto bad; 1748 } 1749 1750 /* 1751 * Now bind to the device. 1752 */ 1753 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1754 #ifdef BIOCSETLIF 1755 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) < 0) 1756 #else 1757 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) 1758 #endif 1759 { 1760 status = check_setif_failure(p, errno); 1761 goto bad; 1762 } 1763 } else { 1764 /* 1765 * No buffer size was explicitly specified. 1766 * 1767 * Try finding a good size for the buffer; 1768 * DEFAULT_BUFSIZE may be too big, so keep 1769 * cutting it in half until we find a size 1770 * that works, or run out of sizes to try. 1771 * If the default is larger, don't make it smaller. 1772 */ 1773 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 1774 v < DEFAULT_BUFSIZE) 1775 v = DEFAULT_BUFSIZE; 1776 for ( ; v != 0; v >>= 1) { 1777 /* 1778 * Ignore the return value - this is because the 1779 * call fails on BPF systems that don't have 1780 * kernel malloc. And if the call fails, it's 1781 * no big deal, we just continue to use the 1782 * standard buffer size. 1783 */ 1784 (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v); 1785 1786 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1787 #ifdef BIOCSETLIF 1788 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) >= 0) 1789 #else 1790 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0) 1791 #endif 1792 break; /* that size worked; we're done */ 1793 1794 if (errno != ENOBUFS) { 1795 status = check_setif_failure(p, errno); 1796 goto bad; 1797 } 1798 } 1799 1800 if (v == 0) { 1801 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1802 "BIOCSBLEN: %s: No buffer size worked", 1803 p->opt.source); 1804 status = PCAP_ERROR; 1805 goto bad; 1806 } 1807 } 1808 } 1809 1810 /* Get the data link layer type. */ 1811 if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) { 1812 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s", 1813 pcap_strerror(errno)); 1814 status = PCAP_ERROR; 1815 goto bad; 1816 } 1817 1818 #ifdef _AIX 1819 /* 1820 * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT. 1821 */ 1822 switch (v) { 1823 1824 case IFT_ETHER: 1825 case IFT_ISO88023: 1826 v = DLT_EN10MB; 1827 break; 1828 1829 case IFT_FDDI: 1830 v = DLT_FDDI; 1831 break; 1832 1833 case IFT_ISO88025: 1834 v = DLT_IEEE802; 1835 break; 1836 1837 case IFT_LOOP: 1838 v = DLT_NULL; 1839 break; 1840 1841 default: 1842 /* 1843 * We don't know what to map this to yet. 1844 */ 1845 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", 1846 v); 1847 status = PCAP_ERROR; 1848 goto bad; 1849 } 1850 #endif 1851 #if _BSDI_VERSION - 0 >= 199510 1852 /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */ 1853 switch (v) { 1854 1855 case DLT_SLIP: 1856 v = DLT_SLIP_BSDOS; 1857 break; 1858 1859 case DLT_PPP: 1860 v = DLT_PPP_BSDOS; 1861 break; 1862 1863 case 11: /*DLT_FR*/ 1864 v = DLT_FRELAY; 1865 break; 1866 1867 case 12: /*DLT_C_HDLC*/ 1868 v = DLT_CHDLC; 1869 break; 1870 } 1871 #endif 1872 1873 #ifdef BIOCGDLTLIST 1874 /* 1875 * We know the default link type -- now determine all the DLTs 1876 * this interface supports. If this fails with EINVAL, it's 1877 * not fatal; we just don't get to use the feature later. 1878 */ 1879 if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) { 1880 status = PCAP_ERROR; 1881 goto bad; 1882 } 1883 p->dlt_count = bdl.bfl_len; 1884 p->dlt_list = bdl.bfl_list; 1885 1886 #ifdef __APPLE__ 1887 /* 1888 * Monitor mode fun, continued. 1889 * 1890 * For 10.5 and, we're assuming, later releases, as noted above, 1891 * 802.1 adapters that support monitor mode offer both DLT_EN10MB, 1892 * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information 1893 * DLT_ value. Choosing one of the 802.11 DLT_ values will turn 1894 * monitor mode on. 1895 * 1896 * Therefore, if the user asked for monitor mode, we filter out 1897 * the DLT_EN10MB value, as you can't get that in monitor mode, 1898 * and, if the user didn't ask for monitor mode, we filter out 1899 * the 802.11 DLT_ values, because selecting those will turn 1900 * monitor mode on. Then, for monitor mode, if an 802.11-plus- 1901 * radio DLT_ value is offered, we try to select that, otherwise 1902 * we try to select DLT_IEEE802_11. 1903 */ 1904 if (have_osinfo) { 1905 if (isdigit((unsigned)osinfo.release[0]) && 1906 (osinfo.release[0] == '9' || 1907 isdigit((unsigned)osinfo.release[1]))) { 1908 /* 1909 * 10.5 (Darwin 9.x), or later. 1910 */ 1911 new_dlt = find_802_11(&bdl); 1912 if (new_dlt != -1) { 1913 /* 1914 * We have at least one 802.11 DLT_ value, 1915 * so this is an 802.11 interface. 1916 * new_dlt is the best of the 802.11 1917 * DLT_ values in the list. 1918 */ 1919 if (p->opt.rfmon) { 1920 /* 1921 * Our caller wants monitor mode. 1922 * Purge DLT_EN10MB from the list 1923 * of link-layer types, as selecting 1924 * it will keep monitor mode off. 1925 */ 1926 remove_en(p); 1927 1928 /* 1929 * If the new mode we want isn't 1930 * the default mode, attempt to 1931 * select the new mode. 1932 */ 1933 if (new_dlt != v) { 1934 if (ioctl(p->fd, BIOCSDLT, 1935 &new_dlt) != -1) { 1936 /* 1937 * We succeeded; 1938 * make this the 1939 * new DLT_ value. 1940 */ 1941 v = new_dlt; 1942 } 1943 } 1944 } else { 1945 /* 1946 * Our caller doesn't want 1947 * monitor mode. Unless this 1948 * is being done by pcap_open_live(), 1949 * purge the 802.11 link-layer types 1950 * from the list, as selecting 1951 * one of them will turn monitor 1952 * mode on. 1953 */ 1954 if (!p->oldstyle) 1955 remove_802_11(p); 1956 } 1957 } else { 1958 if (p->opt.rfmon) { 1959 /* 1960 * The caller requested monitor 1961 * mode, but we have no 802.11 1962 * link-layer types, so they 1963 * can't have it. 1964 */ 1965 status = PCAP_ERROR_RFMON_NOTSUP; 1966 goto bad; 1967 } 1968 } 1969 } 1970 } 1971 #elif defined(HAVE_BSD_IEEE80211) 1972 /* 1973 * *BSD with the new 802.11 ioctls. 1974 * Do we want monitor mode? 1975 */ 1976 if (p->opt.rfmon) { 1977 /* 1978 * Try to put the interface into monitor mode. 1979 */ 1980 status = monitor_mode(p, 1); 1981 if (status != 0) { 1982 /* 1983 * We failed. 1984 */ 1985 goto bad; 1986 } 1987 1988 /* 1989 * We're in monitor mode. 1990 * Try to find the best 802.11 DLT_ value and, if we 1991 * succeed, try to switch to that mode if we're not 1992 * already in that mode. 1993 */ 1994 new_dlt = find_802_11(&bdl); 1995 if (new_dlt != -1) { 1996 /* 1997 * We have at least one 802.11 DLT_ value. 1998 * new_dlt is the best of the 802.11 1999 * DLT_ values in the list. 2000 * 2001 * If the new mode we want isn't the default mode, 2002 * attempt to select the new mode. 2003 */ 2004 if (new_dlt != v) { 2005 if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) { 2006 /* 2007 * We succeeded; make this the 2008 * new DLT_ value. 2009 */ 2010 v = new_dlt; 2011 } 2012 } 2013 } 2014 } 2015 #endif /* various platforms */ 2016 #endif /* BIOCGDLTLIST */ 2017 2018 /* 2019 * If this is an Ethernet device, and we don't have a DLT_ list, 2020 * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give 2021 * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to 2022 * do, but there's not much we can do about that without finding 2023 * some other way of determining whether it's an Ethernet or 802.11 2024 * device.) 2025 */ 2026 if (v == DLT_EN10MB && p->dlt_count == 0) { 2027 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 2028 /* 2029 * If that fails, just leave the list empty. 2030 */ 2031 if (p->dlt_list != NULL) { 2032 p->dlt_list[0] = DLT_EN10MB; 2033 p->dlt_list[1] = DLT_DOCSIS; 2034 p->dlt_count = 2; 2035 } 2036 } 2037 #ifdef PCAP_FDDIPAD 2038 if (v == DLT_FDDI) 2039 p->fddipad = PCAP_FDDIPAD; 2040 else 2041 #endif 2042 p->fddipad = 0; 2043 p->linktype = v; 2044 2045 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 2046 /* 2047 * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so 2048 * the link-layer source address isn't forcibly overwritten. 2049 * (Should we ignore errors? Should we do this only if 2050 * we're open for writing?) 2051 * 2052 * XXX - I seem to remember some packet-sending bug in some 2053 * BSDs - check CVS log for "bpf.c"? 2054 */ 2055 if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 2056 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2057 "BIOCSHDRCMPLT: %s", pcap_strerror(errno)); 2058 status = PCAP_ERROR; 2059 goto bad; 2060 } 2061 #endif 2062 /* set timeout */ 2063 #ifdef HAVE_ZEROCOPY_BPF 2064 /* 2065 * In zero-copy mode, we just use the timeout in select(). 2066 * XXX - what if we're in non-blocking mode and the *application* 2067 * is using select() or poll() or kqueues or....? 2068 */ 2069 if (p->opt.timeout && !pb->zerocopy) { 2070 #else 2071 if (p->opt.timeout) { 2072 #endif 2073 /* 2074 * XXX - is this seconds/nanoseconds in AIX? 2075 * (Treating it as such doesn't fix the timeout 2076 * problem described below.) 2077 * 2078 * XXX - Mac OS X 10.6 mishandles BIOCSRTIMEOUT in 2079 * 64-bit userland - it takes, as an argument, a 2080 * "struct BPF_TIMEVAL", which has 32-bit tv_sec 2081 * and tv_usec, rather than a "struct timeval". 2082 * 2083 * If this platform defines "struct BPF_TIMEVAL", 2084 * we check whether the structure size in BIOCSRTIMEOUT 2085 * is that of a "struct timeval" and, if not, we use 2086 * a "struct BPF_TIMEVAL" rather than a "struct timeval". 2087 * (That way, if the bug is fixed in a future release, 2088 * we will still do the right thing.) 2089 */ 2090 struct timeval to; 2091 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2092 struct BPF_TIMEVAL bpf_to; 2093 2094 if (IOCPARM_LEN(BIOCSRTIMEOUT) != sizeof(struct timeval)) { 2095 bpf_to.tv_sec = p->opt.timeout / 1000; 2096 bpf_to.tv_usec = (p->opt.timeout * 1000) % 1000000; 2097 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&bpf_to) < 0) { 2098 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2099 "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); 2100 status = PCAP_ERROR; 2101 goto bad; 2102 } 2103 } else { 2104 #endif 2105 to.tv_sec = p->opt.timeout / 1000; 2106 to.tv_usec = (p->opt.timeout * 1000) % 1000000; 2107 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) { 2108 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2109 "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); 2110 status = PCAP_ERROR; 2111 goto bad; 2112 } 2113 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2114 } 2115 #endif 2116 } 2117 2118 #ifdef BIOCIMMEDIATE 2119 /* 2120 * Darren Reed notes that 2121 * 2122 * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the 2123 * timeout appears to be ignored and it waits until the buffer 2124 * is filled before returning. The result of not having it 2125 * set is almost worse than useless if your BPF filter 2126 * is reducing things to only a few packets (i.e. one every 2127 * second or so). 2128 * 2129 * so we always turn BIOCIMMEDIATE mode on if this is AIX. 2130 * 2131 * For other platforms, we don't turn immediate mode on by default, 2132 * as that would mean we get woken up for every packet, which 2133 * probably isn't what you want for a packet sniffer. 2134 * 2135 * We set immediate mode if the caller requested it by calling 2136 * pcap_set_immediate() before calling pcap_activate(). 2137 */ 2138 #ifndef _AIX 2139 if (p->opt.immediate) { 2140 #endif /* _AIX */ 2141 v = 1; 2142 if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) { 2143 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2144 "BIOCIMMEDIATE: %s", pcap_strerror(errno)); 2145 status = PCAP_ERROR; 2146 goto bad; 2147 } 2148 #ifndef _AIX 2149 } 2150 #endif /* _AIX */ 2151 #else /* BIOCIMMEDIATE */ 2152 if (p->opt.immediate) { 2153 /* 2154 * We don't support immediate mode. Fail. 2155 */ 2156 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Immediate mode not supported"); 2157 status = PCAP_ERROR; 2158 goto bad; 2159 } 2160 #endif /* BIOCIMMEDIATE */ 2161 2162 if (p->opt.promisc) { 2163 /* set promiscuous mode, just warn if it fails */ 2164 if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) { 2165 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s", 2166 pcap_strerror(errno)); 2167 status = PCAP_WARNING_PROMISC_NOTSUP; 2168 } 2169 } 2170 2171 if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) { 2172 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s", 2173 pcap_strerror(errno)); 2174 status = PCAP_ERROR; 2175 goto bad; 2176 } 2177 p->bufsize = v; 2178 #ifdef HAVE_ZEROCOPY_BPF 2179 if (!pb->zerocopy) { 2180 #endif 2181 p->buffer = (u_char *)malloc(p->bufsize); 2182 if (p->buffer == NULL) { 2183 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", 2184 pcap_strerror(errno)); 2185 status = PCAP_ERROR; 2186 goto bad; 2187 } 2188 #ifdef _AIX 2189 /* For some strange reason this seems to prevent the EFAULT 2190 * problems we have experienced from AIX BPF. */ 2191 memset(p->buffer, 0x0, p->bufsize); 2192 #endif 2193 #ifdef HAVE_ZEROCOPY_BPF 2194 } 2195 #endif 2196 2197 /* 2198 * If there's no filter program installed, there's 2199 * no indication to the kernel of what the snapshot 2200 * length should be, so no snapshotting is done. 2201 * 2202 * Therefore, when we open the device, we install 2203 * an "accept everything" filter with the specified 2204 * snapshot length. 2205 */ 2206 total_insn.code = (u_short)(BPF_RET | BPF_K); 2207 total_insn.jt = 0; 2208 total_insn.jf = 0; 2209 total_insn.k = p->snapshot; 2210 2211 total_prog.bf_len = 1; 2212 total_prog.bf_insns = &total_insn; 2213 if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) { 2214 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", 2215 pcap_strerror(errno)); 2216 status = PCAP_ERROR; 2217 goto bad; 2218 } 2219 2220 /* 2221 * On most BPF platforms, either you can do a "select()" or 2222 * "poll()" on a BPF file descriptor and it works correctly, 2223 * or you can do it and it will return "readable" if the 2224 * hold buffer is full but not if the timeout expires *and* 2225 * a non-blocking read will, if the hold buffer is empty 2226 * but the store buffer isn't empty, rotate the buffers 2227 * and return what packets are available. 2228 * 2229 * In the latter case, the fact that a non-blocking read 2230 * will give you the available packets means you can work 2231 * around the failure of "select()" and "poll()" to wake up 2232 * and return "readable" when the timeout expires by using 2233 * the timeout as the "select()" or "poll()" timeout, putting 2234 * the BPF descriptor into non-blocking mode, and read from 2235 * it regardless of whether "select()" reports it as readable 2236 * or not. 2237 * 2238 * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()" 2239 * won't wake up and return "readable" if the timer expires 2240 * and non-blocking reads return EWOULDBLOCK if the hold 2241 * buffer is empty, even if the store buffer is non-empty. 2242 * 2243 * This means the workaround in question won't work. 2244 * 2245 * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd" 2246 * to -1, which means "sorry, you can't use 'select()' or 'poll()' 2247 * here". On all other BPF platforms, we set it to the FD for 2248 * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking 2249 * read will, if the hold buffer is empty and the store buffer 2250 * isn't empty, rotate the buffers and return what packets are 2251 * there (and in sufficiently recent versions of OpenBSD 2252 * "select()" and "poll()" should work correctly). 2253 * 2254 * XXX - what about AIX? 2255 */ 2256 p->selectable_fd = p->fd; /* assume select() works until we know otherwise */ 2257 if (have_osinfo) { 2258 /* 2259 * We can check what OS this is. 2260 */ 2261 if (strcmp(osinfo.sysname, "FreeBSD") == 0) { 2262 if (strncmp(osinfo.release, "4.3-", 4) == 0 || 2263 strncmp(osinfo.release, "4.4-", 4) == 0) 2264 p->selectable_fd = -1; 2265 } 2266 } 2267 2268 p->read_op = pcap_read_bpf; 2269 p->inject_op = pcap_inject_bpf; 2270 p->setfilter_op = pcap_setfilter_bpf; 2271 p->setdirection_op = pcap_setdirection_bpf; 2272 p->set_datalink_op = pcap_set_datalink_bpf; 2273 p->getnonblock_op = pcap_getnonblock_bpf; 2274 p->setnonblock_op = pcap_setnonblock_bpf; 2275 p->stats_op = pcap_stats_bpf; 2276 p->cleanup_op = pcap_cleanup_bpf; 2277 2278 return (status); 2279 bad: 2280 pcap_cleanup_bpf(p); 2281 return (status); 2282 } 2283 2284 int 2285 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 2286 { 2287 return (0); 2288 } 2289 2290 #ifdef HAVE_BSD_IEEE80211 2291 static int 2292 monitor_mode(pcap_t *p, int set) 2293 { 2294 struct pcap_bpf *pb = p->priv; 2295 int sock; 2296 struct ifmediareq req; 2297 int *media_list; 2298 int i; 2299 int can_do; 2300 struct ifreq ifr; 2301 2302 sock = socket(AF_INET, SOCK_DGRAM, 0); 2303 if (sock == -1) { 2304 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s", 2305 pcap_strerror(errno)); 2306 return (PCAP_ERROR); 2307 } 2308 2309 memset(&req, 0, sizeof req); 2310 strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name); 2311 2312 /* 2313 * Find out how many media types we have. 2314 */ 2315 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 2316 /* 2317 * Can't get the media types. 2318 */ 2319 switch (errno) { 2320 2321 case ENXIO: 2322 /* 2323 * There's no such device. 2324 */ 2325 close(sock); 2326 return (PCAP_ERROR_NO_SUCH_DEVICE); 2327 2328 case EINVAL: 2329 /* 2330 * Interface doesn't support SIOC{G,S}IFMEDIA. 2331 */ 2332 close(sock); 2333 return (PCAP_ERROR_RFMON_NOTSUP); 2334 2335 default: 2336 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2337 "SIOCGIFMEDIA 1: %s", pcap_strerror(errno)); 2338 close(sock); 2339 return (PCAP_ERROR); 2340 } 2341 } 2342 if (req.ifm_count == 0) { 2343 /* 2344 * No media types. 2345 */ 2346 close(sock); 2347 return (PCAP_ERROR_RFMON_NOTSUP); 2348 } 2349 2350 /* 2351 * Allocate a buffer to hold all the media types, and 2352 * get the media types. 2353 */ 2354 media_list = malloc(req.ifm_count * sizeof(int)); 2355 if (media_list == NULL) { 2356 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", 2357 pcap_strerror(errno)); 2358 close(sock); 2359 return (PCAP_ERROR); 2360 } 2361 req.ifm_ulist = media_list; 2362 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 2363 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s", 2364 pcap_strerror(errno)); 2365 free(media_list); 2366 close(sock); 2367 return (PCAP_ERROR); 2368 } 2369 2370 /* 2371 * Look for an 802.11 "automatic" media type. 2372 * We assume that all 802.11 adapters have that media type, 2373 * and that it will carry the monitor mode supported flag. 2374 */ 2375 can_do = 0; 2376 for (i = 0; i < req.ifm_count; i++) { 2377 if (IFM_TYPE(media_list[i]) == IFM_IEEE80211 2378 && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) { 2379 /* OK, does it do monitor mode? */ 2380 if (media_list[i] & IFM_IEEE80211_MONITOR) { 2381 can_do = 1; 2382 break; 2383 } 2384 } 2385 } 2386 free(media_list); 2387 if (!can_do) { 2388 /* 2389 * This adapter doesn't support monitor mode. 2390 */ 2391 close(sock); 2392 return (PCAP_ERROR_RFMON_NOTSUP); 2393 } 2394 2395 if (set) { 2396 /* 2397 * Don't just check whether we can enable monitor mode, 2398 * do so, if it's not already enabled. 2399 */ 2400 if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) { 2401 /* 2402 * Monitor mode isn't currently on, so turn it on, 2403 * and remember that we should turn it off when the 2404 * pcap_t is closed. 2405 */ 2406 2407 /* 2408 * If we haven't already done so, arrange to have 2409 * "pcap_close_all()" called when we exit. 2410 */ 2411 if (!pcap_do_addexit(p)) { 2412 /* 2413 * "atexit()" failed; don't put the interface 2414 * in monitor mode, just give up. 2415 */ 2416 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2417 "atexit failed"); 2418 close(sock); 2419 return (PCAP_ERROR); 2420 } 2421 memset(&ifr, 0, sizeof(ifr)); 2422 (void)strncpy(ifr.ifr_name, p->opt.source, 2423 sizeof(ifr.ifr_name)); 2424 ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR; 2425 if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) { 2426 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2427 "SIOCSIFMEDIA: %s", pcap_strerror(errno)); 2428 close(sock); 2429 return (PCAP_ERROR); 2430 } 2431 2432 pb->must_do_on_close |= MUST_CLEAR_RFMON; 2433 2434 /* 2435 * Add this to the list of pcaps to close when we exit. 2436 */ 2437 pcap_add_to_pcaps_to_close(p); 2438 } 2439 } 2440 return (0); 2441 } 2442 #endif /* HAVE_BSD_IEEE80211 */ 2443 2444 #if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) 2445 /* 2446 * Check whether we have any 802.11 link-layer types; return the best 2447 * of the 802.11 link-layer types if we find one, and return -1 2448 * otherwise. 2449 * 2450 * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the 2451 * best 802.11 link-layer type; any of the other 802.11-plus-radio 2452 * headers are second-best; 802.11 with no radio information is 2453 * the least good. 2454 */ 2455 static int 2456 find_802_11(struct bpf_dltlist *bdlp) 2457 { 2458 int new_dlt; 2459 int i; 2460 2461 /* 2462 * Scan the list of DLT_ values, looking for 802.11 values, 2463 * and, if we find any, choose the best of them. 2464 */ 2465 new_dlt = -1; 2466 for (i = 0; i < bdlp->bfl_len; i++) { 2467 switch (bdlp->bfl_list[i]) { 2468 2469 case DLT_IEEE802_11: 2470 /* 2471 * 802.11, but no radio. 2472 * 2473 * Offer this, and select it as the new mode 2474 * unless we've already found an 802.11 2475 * header with radio information. 2476 */ 2477 if (new_dlt == -1) 2478 new_dlt = bdlp->bfl_list[i]; 2479 break; 2480 2481 case DLT_PRISM_HEADER: 2482 case DLT_AIRONET_HEADER: 2483 case DLT_IEEE802_11_RADIO_AVS: 2484 /* 2485 * 802.11 with radio, but not radiotap. 2486 * 2487 * Offer this, and select it as the new mode 2488 * unless we've already found the radiotap DLT_. 2489 */ 2490 if (new_dlt != DLT_IEEE802_11_RADIO) 2491 new_dlt = bdlp->bfl_list[i]; 2492 break; 2493 2494 case DLT_IEEE802_11_RADIO: 2495 /* 2496 * 802.11 with radiotap. 2497 * 2498 * Offer this, and select it as the new mode. 2499 */ 2500 new_dlt = bdlp->bfl_list[i]; 2501 break; 2502 2503 default: 2504 /* 2505 * Not 802.11. 2506 */ 2507 break; 2508 } 2509 } 2510 2511 return (new_dlt); 2512 } 2513 #endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */ 2514 2515 #if defined(__APPLE__) && defined(BIOCGDLTLIST) 2516 /* 2517 * Remove DLT_EN10MB from the list of DLT_ values, as we're in monitor mode, 2518 * and DLT_EN10MB isn't supported in monitor mode. 2519 */ 2520 static void 2521 remove_en(pcap_t *p) 2522 { 2523 int i, j; 2524 2525 /* 2526 * Scan the list of DLT_ values and discard DLT_EN10MB. 2527 */ 2528 j = 0; 2529 for (i = 0; i < p->dlt_count; i++) { 2530 switch (p->dlt_list[i]) { 2531 2532 case DLT_EN10MB: 2533 /* 2534 * Don't offer this one. 2535 */ 2536 continue; 2537 2538 default: 2539 /* 2540 * Just copy this mode over. 2541 */ 2542 break; 2543 } 2544 2545 /* 2546 * Copy this DLT_ value to its new position. 2547 */ 2548 p->dlt_list[j] = p->dlt_list[i]; 2549 j++; 2550 } 2551 2552 /* 2553 * Set the DLT_ count to the number of entries we copied. 2554 */ 2555 p->dlt_count = j; 2556 } 2557 2558 /* 2559 * Remove 802.11 link-layer types from the list of DLT_ values, as 2560 * we're not in monitor mode, and those DLT_ values will switch us 2561 * to monitor mode. 2562 */ 2563 static void 2564 remove_802_11(pcap_t *p) 2565 { 2566 int i, j; 2567 2568 /* 2569 * Scan the list of DLT_ values and discard 802.11 values. 2570 */ 2571 j = 0; 2572 for (i = 0; i < p->dlt_count; i++) { 2573 switch (p->dlt_list[i]) { 2574 2575 case DLT_IEEE802_11: 2576 case DLT_PRISM_HEADER: 2577 case DLT_AIRONET_HEADER: 2578 case DLT_IEEE802_11_RADIO: 2579 case DLT_IEEE802_11_RADIO_AVS: 2580 /* 2581 * 802.11. Don't offer this one. 2582 */ 2583 continue; 2584 2585 default: 2586 /* 2587 * Just copy this mode over. 2588 */ 2589 break; 2590 } 2591 2592 /* 2593 * Copy this DLT_ value to its new position. 2594 */ 2595 p->dlt_list[j] = p->dlt_list[i]; 2596 j++; 2597 } 2598 2599 /* 2600 * Set the DLT_ count to the number of entries we copied. 2601 */ 2602 p->dlt_count = j; 2603 } 2604 #endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */ 2605 2606 static int 2607 pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) 2608 { 2609 struct pcap_bpf *pb = p->priv; 2610 2611 /* 2612 * Free any user-mode filter we might happen to have installed. 2613 */ 2614 pcap_freecode(&p->fcode); 2615 2616 /* 2617 * Try to install the kernel filter. 2618 */ 2619 if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) { 2620 /* 2621 * It worked. 2622 */ 2623 pb->filtering_in_kernel = 1; /* filtering in the kernel */ 2624 2625 /* 2626 * Discard any previously-received packets, as they might 2627 * have passed whatever filter was formerly in effect, but 2628 * might not pass this filter (BIOCSETF discards packets 2629 * buffered in the kernel, so you can lose packets in any 2630 * case). 2631 */ 2632 p->cc = 0; 2633 return (0); 2634 } 2635 2636 /* 2637 * We failed. 2638 * 2639 * If it failed with EINVAL, that's probably because the program 2640 * is invalid or too big. Validate it ourselves; if we like it 2641 * (we currently allow backward branches, to support protochain), 2642 * run it in userland. (There's no notion of "too big" for 2643 * userland.) 2644 * 2645 * Otherwise, just give up. 2646 * XXX - if the copy of the program into the kernel failed, 2647 * we will get EINVAL rather than, say, EFAULT on at least 2648 * some kernels. 2649 */ 2650 if (errno != EINVAL) { 2651 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", 2652 pcap_strerror(errno)); 2653 return (-1); 2654 } 2655 2656 /* 2657 * install_bpf_program() validates the program. 2658 * 2659 * XXX - what if we already have a filter in the kernel? 2660 */ 2661 if (install_bpf_program(p, fp) < 0) 2662 return (-1); 2663 pb->filtering_in_kernel = 0; /* filtering in userland */ 2664 return (0); 2665 } 2666 2667 /* 2668 * Set direction flag: Which packets do we accept on a forwarding 2669 * single device? IN, OUT or both? 2670 */ 2671 static int 2672 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d) 2673 { 2674 #if defined(BIOCSDIRECTION) 2675 u_int direction; 2676 2677 direction = (d == PCAP_D_IN) ? BPF_D_IN : 2678 ((d == PCAP_D_OUT) ? BPF_D_OUT : BPF_D_INOUT); 2679 if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) { 2680 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2681 "Cannot set direction to %s: %s", 2682 (d == PCAP_D_IN) ? "PCAP_D_IN" : 2683 ((d == PCAP_D_OUT) ? "PCAP_D_OUT" : "PCAP_D_INOUT"), 2684 strerror(errno)); 2685 return (-1); 2686 } 2687 return (0); 2688 #elif defined(BIOCSSEESENT) 2689 u_int seesent; 2690 2691 /* 2692 * We don't support PCAP_D_OUT. 2693 */ 2694 if (d == PCAP_D_OUT) { 2695 snprintf(p->errbuf, sizeof(p->errbuf), 2696 "Setting direction to PCAP_D_OUT is not supported on BPF"); 2697 return -1; 2698 } 2699 2700 seesent = (d == PCAP_D_INOUT); 2701 if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) { 2702 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2703 "Cannot set direction to %s: %s", 2704 (d == PCAP_D_INOUT) ? "PCAP_D_INOUT" : "PCAP_D_IN", 2705 strerror(errno)); 2706 return (-1); 2707 } 2708 return (0); 2709 #else 2710 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2711 "This system doesn't support BIOCSSEESENT, so the direction can't be set"); 2712 return (-1); 2713 #endif 2714 } 2715 2716 static int 2717 pcap_set_datalink_bpf(pcap_t *p, int dlt) 2718 { 2719 #ifdef BIOCSDLT 2720 if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) { 2721 (void) snprintf(p->errbuf, sizeof(p->errbuf), 2722 "Cannot set DLT %d: %s", dlt, strerror(errno)); 2723 return (-1); 2724 } 2725 #endif 2726 return (0); 2727 } 2728