1 /* $NetBSD: pcap-bpf.c,v 1.4 2013/12/31 17:08:23 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1993, 1994, 1995, 1996, 1998 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 #ifndef lint 24 static const char rcsid[] _U_ = 25 "@(#) Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.116 2008-09-16 18:42:29 guy Exp (LBL)"; 26 #endif 27 28 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 32 #include <sys/param.h> /* optionally get BSD define */ 33 #ifdef HAVE_ZEROCOPY_BPF 34 #include <sys/mman.h> 35 #endif 36 #include <sys/socket.h> 37 #include <time.h> 38 /* 39 * <net/bpf.h> defines ioctls, but doesn't include <sys/ioccom.h>. 40 * 41 * We include <sys/ioctl.h> as it might be necessary to declare ioctl(); 42 * at least on *BSD and Mac OS X, it also defines various SIOC ioctls - 43 * we could include <sys/sockio.h>, but if we're already including 44 * <sys/ioctl.h>, which includes <sys/sockio.h> on those platforms, 45 * there's not much point in doing so. 46 * 47 * If we have <sys/ioccom.h>, we include it as well, to handle systems 48 * such as Solaris which don't arrange to include <sys/ioccom.h> if you 49 * include <sys/ioctl.h> 50 */ 51 #include <sys/ioctl.h> 52 #ifdef HAVE_SYS_IOCCOM_H 53 #include <sys/ioccom.h> 54 #endif 55 #include <sys/utsname.h> 56 #ifdef __NetBSD__ 57 #include <paths.h> 58 #endif 59 60 #ifdef HAVE_ZEROCOPY_BPF 61 #include <machine/atomic.h> 62 #endif 63 64 #include <net/if.h> 65 66 #ifdef _AIX 67 68 /* 69 * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the 70 * native OS version, as we need "struct bpf_config" from it. 71 */ 72 #define PCAP_DONT_INCLUDE_PCAP_BPF_H 73 74 #include <sys/types.h> 75 76 /* 77 * Prevent bpf.h from redefining the DLT_ values to their 78 * IFT_ values, as we're going to return the standard libpcap 79 * values, not IBM's non-standard IFT_ values. 80 */ 81 #undef _AIX 82 #include <net/bpf.h> 83 #define _AIX 84 85 #include <net/if_types.h> /* for IFT_ values */ 86 #include <sys/sysconfig.h> 87 #include <sys/device.h> 88 #include <sys/cfgodm.h> 89 #include <cf.h> 90 91 #ifdef __64BIT__ 92 #define domakedev makedev64 93 #define getmajor major64 94 #define bpf_hdr bpf_hdr32 95 #else /* __64BIT__ */ 96 #define domakedev makedev 97 #define getmajor major 98 #endif /* __64BIT__ */ 99 100 #define BPF_NAME "bpf" 101 #define BPF_MINORS 4 102 #define DRIVER_PATH "/usr/lib/drivers" 103 #define BPF_NODE "/dev/bpf" 104 static int bpfloadedflag = 0; 105 static int odmlockid = 0; 106 107 static int bpf_load(char *errbuf); 108 109 #else /* _AIX */ 110 111 #include <net/bpf.h> 112 113 #endif /* _AIX */ 114 115 #include <ctype.h> 116 #include <fcntl.h> 117 #include <errno.h> 118 #include <netdb.h> 119 #include <stdio.h> 120 #include <stdlib.h> 121 #include <string.h> 122 #include <unistd.h> 123 124 #ifdef HAVE_NET_IF_MEDIA_H 125 # include <net/if_media.h> 126 #endif 127 128 #include "pcap-int.h" 129 130 #ifdef HAVE_OS_PROTO_H 131 #include "os-proto.h" 132 #endif 133 134 /* 135 * Later versions of NetBSD stick padding in front of FDDI frames 136 * to align the IP header on a 4-byte boundary. 137 */ 138 #if defined(__NetBSD__) && __NetBSD_Version__ > 106000000 139 #define PCAP_FDDIPAD 3 140 #endif 141 142 /* 143 * Private data for capturing on BPF devices. 144 */ 145 struct pcap_bpf { 146 #ifdef PCAP_FDDIPAD 147 int fddipad; 148 #endif 149 150 #ifdef HAVE_ZEROCOPY_BPF 151 /* 152 * Zero-copy read buffer -- for zero-copy BPF. 'buffer' above will 153 * alternative between these two actual mmap'd buffers as required. 154 * As there is a header on the front size of the mmap'd buffer, only 155 * some of the buffer is exposed to libpcap as a whole via bufsize; 156 * zbufsize is the true size. zbuffer tracks the current zbuf 157 * assocated with buffer so that it can be used to decide which the 158 * next buffer to read will be. 159 */ 160 u_char *zbuf1, *zbuf2, *zbuffer; 161 u_int zbufsize; 162 u_int zerocopy; 163 u_int interrupted; 164 struct timespec firstsel; 165 /* 166 * If there's currently a buffer being actively processed, then it is 167 * referenced here; 'buffer' is also pointed at it, but offset by the 168 * size of the header. 169 */ 170 struct bpf_zbuf_header *bzh; 171 int nonblock; /* true if in nonblocking mode */ 172 #endif /* HAVE_ZEROCOPY_BPF */ 173 174 char *device; /* device name */ 175 int filtering_in_kernel; /* using kernel filter */ 176 int must_do_on_close; /* stuff we must do when we close */ 177 }; 178 179 /* 180 * Stuff to do when we close. 181 */ 182 #define MUST_CLEAR_RFMON 0x00000001 /* clear rfmon (monitor) mode */ 183 184 #ifdef BIOCGDLTLIST 185 # if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__) 186 #define HAVE_BSD_IEEE80211 187 # endif 188 189 # if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 190 static int find_802_11(struct bpf_dltlist *); 191 192 # ifdef HAVE_BSD_IEEE80211 193 static int monitor_mode(pcap_t *, int); 194 # endif 195 196 # if defined(__APPLE__) 197 static void remove_en(pcap_t *); 198 static void remove_802_11(pcap_t *); 199 # endif 200 201 # endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */ 202 203 #endif /* BIOCGDLTLIST */ 204 205 #if defined(sun) && defined(LIFNAMSIZ) && defined(lifr_zoneid) 206 #include <zone.h> 207 #endif 208 209 /* 210 * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably 211 * don't get DLT_DOCSIS defined. 212 */ 213 #ifndef DLT_DOCSIS 214 #define DLT_DOCSIS 143 215 #endif 216 217 /* 218 * On OS X, we don't even get any of the 802.11-plus-radio-header DLT_'s 219 * defined, even though some of them are used by various Airport drivers. 220 */ 221 #ifndef DLT_PRISM_HEADER 222 #define DLT_PRISM_HEADER 119 223 #endif 224 #ifndef DLT_AIRONET_HEADER 225 #define DLT_AIRONET_HEADER 120 226 #endif 227 #ifndef DLT_IEEE802_11_RADIO 228 #define DLT_IEEE802_11_RADIO 127 229 #endif 230 #ifndef DLT_IEEE802_11_RADIO_AVS 231 #define DLT_IEEE802_11_RADIO_AVS 163 232 #endif 233 234 static int pcap_can_set_rfmon_bpf(pcap_t *p); 235 static int pcap_activate_bpf(pcap_t *p); 236 static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp); 237 static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t); 238 static int pcap_set_datalink_bpf(pcap_t *p, int dlt); 239 240 /* 241 * For zerocopy bpf, the setnonblock/getnonblock routines need to modify 242 * pb->nonblock so we don't call select(2) if the pcap handle is in non- 243 * blocking mode. 244 */ 245 static int 246 pcap_getnonblock_bpf(pcap_t *p, char *errbuf) 247 { 248 #ifdef HAVE_ZEROCOPY_BPF 249 struct pcap_bpf *pb = p->priv; 250 251 if (pb->zerocopy) 252 return (pb->nonblock); 253 #endif 254 return (pcap_getnonblock_fd(p, errbuf)); 255 } 256 257 static int 258 pcap_setnonblock_bpf(pcap_t *p, int nonblock, char *errbuf) 259 { 260 #ifdef HAVE_ZEROCOPY_BPF 261 struct pcap_bpf *pb = p->priv; 262 263 if (pb->zerocopy) { 264 pb->nonblock = nonblock; 265 return (0); 266 } 267 #endif 268 return (pcap_setnonblock_fd(p, nonblock, errbuf)); 269 } 270 271 #ifdef HAVE_ZEROCOPY_BPF 272 /* 273 * Zero-copy BPF buffer routines to check for and acknowledge BPF data in 274 * shared memory buffers. 275 * 276 * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer, 277 * and set up p->buffer and cc to reflect one if available. Notice that if 278 * there was no prior buffer, we select zbuf1 as this will be the first 279 * buffer filled for a fresh BPF session. 280 */ 281 static int 282 pcap_next_zbuf_shm(pcap_t *p, int *cc) 283 { 284 struct pcap_bpf *pb = p->priv; 285 struct bpf_zbuf_header *bzh; 286 287 if (pb->zbuffer == pb->zbuf2 || pb->zbuffer == NULL) { 288 bzh = (struct bpf_zbuf_header *)pb->zbuf1; 289 if (bzh->bzh_user_gen != 290 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 291 pb->bzh = bzh; 292 pb->zbuffer = (u_char *)pb->zbuf1; 293 p->buffer = pb->zbuffer + sizeof(*bzh); 294 *cc = bzh->bzh_kernel_len; 295 return (1); 296 } 297 } else if (pb->zbuffer == pb->zbuf1) { 298 bzh = (struct bpf_zbuf_header *)pb->zbuf2; 299 if (bzh->bzh_user_gen != 300 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 301 pb->bzh = bzh; 302 pb->zbuffer = (u_char *)pb->zbuf2; 303 p->buffer = pb->zbuffer + sizeof(*bzh); 304 *cc = bzh->bzh_kernel_len; 305 return (1); 306 } 307 } 308 *cc = 0; 309 return (0); 310 } 311 312 /* 313 * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using 314 * select() for data or a timeout, and possibly force rotation of the buffer 315 * in the event we time out or are in immediate mode. Invoke the shared 316 * memory check before doing system calls in order to avoid doing avoidable 317 * work. 318 */ 319 static int 320 pcap_next_zbuf(pcap_t *p, int *cc) 321 { 322 struct pcap_bpf *pb = p->priv; 323 struct bpf_zbuf bz; 324 struct timeval tv; 325 struct timespec cur; 326 fd_set r_set; 327 int data, r; 328 int expire, tmout; 329 330 #define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000)) 331 /* 332 * Start out by seeing whether anything is waiting by checking the 333 * next shared memory buffer for data. 334 */ 335 data = pcap_next_zbuf_shm(p, cc); 336 if (data) 337 return (data); 338 /* 339 * If a previous sleep was interrupted due to signal delivery, make 340 * sure that the timeout gets adjusted accordingly. This requires 341 * that we analyze when the timeout should be been expired, and 342 * subtract the current time from that. If after this operation, 343 * our timeout is less then or equal to zero, handle it like a 344 * regular timeout. 345 */ 346 tmout = p->opt.timeout; 347 if (tmout) 348 (void) clock_gettime(CLOCK_MONOTONIC, &cur); 349 if (pb->interrupted && p->opt.timeout) { 350 expire = TSTOMILLI(&pb->firstsel) + p->opt.timeout; 351 tmout = expire - TSTOMILLI(&cur); 352 #undef TSTOMILLI 353 if (tmout <= 0) { 354 pb->interrupted = 0; 355 data = pcap_next_zbuf_shm(p, cc); 356 if (data) 357 return (data); 358 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 359 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 360 "BIOCROTZBUF: %s", strerror(errno)); 361 return (PCAP_ERROR); 362 } 363 return (pcap_next_zbuf_shm(p, cc)); 364 } 365 } 366 /* 367 * No data in the buffer, so must use select() to wait for data or 368 * the next timeout. Note that we only call select if the handle 369 * is in blocking mode. 370 */ 371 if (!pb->nonblock) { 372 FD_ZERO(&r_set); 373 FD_SET(p->fd, &r_set); 374 if (tmout != 0) { 375 tv.tv_sec = tmout / 1000; 376 tv.tv_usec = (tmout * 1000) % 1000000; 377 } 378 r = select(p->fd + 1, &r_set, NULL, NULL, 379 p->opt.timeout != 0 ? &tv : NULL); 380 if (r < 0 && errno == EINTR) { 381 if (!pb->interrupted && p->opt.timeout) { 382 pb->interrupted = 1; 383 pb->firstsel = cur; 384 } 385 return (0); 386 } else if (r < 0) { 387 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 388 "select: %s", strerror(errno)); 389 return (PCAP_ERROR); 390 } 391 } 392 pb->interrupted = 0; 393 /* 394 * Check again for data, which may exist now that we've either been 395 * woken up as a result of data or timed out. Try the "there's data" 396 * case first since it doesn't require a system call. 397 */ 398 data = pcap_next_zbuf_shm(p, cc); 399 if (data) 400 return (data); 401 /* 402 * Try forcing a buffer rotation to dislodge timed out or immediate 403 * data. 404 */ 405 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 406 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 407 "BIOCROTZBUF: %s", strerror(errno)); 408 return (PCAP_ERROR); 409 } 410 return (pcap_next_zbuf_shm(p, cc)); 411 } 412 413 /* 414 * Notify kernel that we are done with the buffer. We don't reset zbuffer so 415 * that we know which buffer to use next time around. 416 */ 417 static int 418 pcap_ack_zbuf(pcap_t *p) 419 { 420 struct pcap_bpf *pb = p->priv; 421 422 atomic_store_rel_int(&pb->bzh->bzh_user_gen, 423 pb->bzh->bzh_kernel_gen); 424 pb->bzh = NULL; 425 p->buffer = NULL; 426 return (0); 427 } 428 #endif /* HAVE_ZEROCOPY_BPF */ 429 430 pcap_t * 431 pcap_create_interface(const char *device, char *ebuf) 432 { 433 pcap_t *p; 434 435 p = pcap_create_common(device, ebuf, sizeof (struct pcap_bpf)); 436 if (p == NULL) 437 return (NULL); 438 439 p->activate_op = pcap_activate_bpf; 440 p->can_set_rfmon_op = pcap_can_set_rfmon_bpf; 441 return (p); 442 } 443 444 /* 445 * On success, returns a file descriptor for a BPF device. 446 * On failure, returns a PCAP_ERROR_ value, and sets p->errbuf. 447 */ 448 static int 449 bpf_open(pcap_t *p) 450 { 451 int fd; 452 #ifdef HAVE_CLONING_BPF 453 static const char device[] = "/dev/bpf"; 454 #else 455 int n = 0; 456 char device[sizeof "/dev/bpf0000000000"]; 457 #endif 458 459 #ifdef _AIX 460 /* 461 * Load the bpf driver, if it isn't already loaded, 462 * and create the BPF device entries, if they don't 463 * already exist. 464 */ 465 if (bpf_load(p->errbuf) == PCAP_ERROR) 466 return (PCAP_ERROR); 467 #endif 468 469 #ifdef HAVE_CLONING_BPF 470 if ((fd = open(device, O_RDWR)) == -1 && 471 (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) { 472 if (errno == EACCES) 473 fd = PCAP_ERROR_PERM_DENIED; 474 else 475 fd = PCAP_ERROR; 476 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 477 "(cannot open device) %s: %s", device, pcap_strerror(errno)); 478 } 479 #else 480 /* 481 * Go through all the minors and find one that isn't in use. 482 */ 483 do { 484 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); 485 /* 486 * Initially try a read/write open (to allow the inject 487 * method to work). If that fails due to permission 488 * issues, fall back to read-only. This allows a 489 * non-root user to be granted specific access to pcap 490 * capabilities via file permissions. 491 * 492 * XXX - we should have an API that has a flag that 493 * controls whether to open read-only or read-write, 494 * so that denial of permission to send (or inability 495 * to send, if sending packets isn't supported on 496 * the device in question) can be indicated at open 497 * time. 498 */ 499 fd = open(device, O_RDWR); 500 if (fd == -1 && errno == EACCES) 501 fd = open(device, O_RDONLY); 502 } while (fd < 0 && errno == EBUSY); 503 504 /* 505 * XXX better message for all minors used 506 */ 507 if (fd < 0) { 508 switch (errno) { 509 510 case ENOENT: 511 fd = PCAP_ERROR; 512 if (n == 1) { 513 /* 514 * /dev/bpf0 doesn't exist, which 515 * means we probably have no BPF 516 * devices. 517 */ 518 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 519 "(there are no BPF devices)"); 520 } else { 521 /* 522 * We got EBUSY on at least one 523 * BPF device, so we have BPF 524 * devices, but all the ones 525 * that exist are busy. 526 */ 527 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 528 "(all BPF devices are busy)"); 529 } 530 break; 531 532 case EACCES: 533 /* 534 * Got EACCES on the last device we tried, 535 * and EBUSY on all devices before that, 536 * if any. 537 */ 538 fd = PCAP_ERROR_PERM_DENIED; 539 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 540 "(cannot open BPF device) %s: %s", device, 541 pcap_strerror(errno)); 542 break; 543 544 default: 545 /* 546 * Some other problem. 547 */ 548 fd = PCAP_ERROR; 549 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 550 "(cannot open BPF device) %s: %s", device, 551 pcap_strerror(errno)); 552 break; 553 } 554 } 555 #endif 556 557 return (fd); 558 } 559 560 #ifdef BIOCGDLTLIST 561 static int 562 get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf) 563 { 564 memset(bdlp, 0, sizeof(*bdlp)); 565 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) { 566 u_int i; 567 int is_ethernet; 568 569 bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1)); 570 if (bdlp->bfl_list == NULL) { 571 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", 572 pcap_strerror(errno)); 573 return (PCAP_ERROR); 574 } 575 576 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) { 577 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, 578 "BIOCGDLTLIST: %s", pcap_strerror(errno)); 579 free(bdlp->bfl_list); 580 return (PCAP_ERROR); 581 } 582 583 /* 584 * OK, for real Ethernet devices, add DLT_DOCSIS to the 585 * list, so that an application can let you choose it, 586 * in case you're capturing DOCSIS traffic that a Cisco 587 * Cable Modem Termination System is putting out onto 588 * an Ethernet (it doesn't put an Ethernet header onto 589 * the wire, it puts raw DOCSIS frames out on the wire 590 * inside the low-level Ethernet framing). 591 * 592 * A "real Ethernet device" is defined here as a device 593 * that has a link-layer type of DLT_EN10MB and that has 594 * no alternate link-layer types; that's done to exclude 595 * 802.11 interfaces (which might or might not be the 596 * right thing to do, but I suspect it is - Ethernet <-> 597 * 802.11 bridges would probably badly mishandle frames 598 * that don't have Ethernet headers). 599 * 600 * On Solaris with BPF, Ethernet devices also offer 601 * DLT_IPNET, so we, if DLT_IPNET is defined, we don't 602 * treat it as an indication that the device isn't an 603 * Ethernet. 604 */ 605 if (v == DLT_EN10MB) { 606 is_ethernet = 1; 607 for (i = 0; i < bdlp->bfl_len; i++) { 608 if (bdlp->bfl_list[i] != DLT_EN10MB 609 #ifdef DLT_IPNET 610 && bdlp->bfl_list[i] != DLT_IPNET 611 #endif 612 ) { 613 is_ethernet = 0; 614 break; 615 } 616 } 617 if (is_ethernet) { 618 /* 619 * We reserved one more slot at the end of 620 * the list. 621 */ 622 bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS; 623 bdlp->bfl_len++; 624 } 625 } 626 } else { 627 /* 628 * EINVAL just means "we don't support this ioctl on 629 * this device"; don't treat it as an error. 630 */ 631 if (errno != EINVAL) { 632 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, 633 "BIOCGDLTLIST: %s", pcap_strerror(errno)); 634 return (PCAP_ERROR); 635 } 636 } 637 return (0); 638 } 639 #endif 640 641 static int 642 pcap_can_set_rfmon_bpf(pcap_t *p) 643 { 644 #if defined(__APPLE__) 645 struct utsname osinfo; 646 struct ifreq ifr; 647 int fd; 648 #ifdef BIOCGDLTLIST 649 struct bpf_dltlist bdl; 650 #endif 651 652 /* 653 * The joys of monitor mode on OS X. 654 * 655 * Prior to 10.4, it's not supported at all. 656 * 657 * In 10.4, if adapter enN supports monitor mode, there's a 658 * wltN adapter corresponding to it; you open it, instead of 659 * enN, to get monitor mode. You get whatever link-layer 660 * headers it supplies. 661 * 662 * In 10.5, and, we assume, later releases, if adapter enN 663 * supports monitor mode, it offers, among its selectable 664 * DLT_ values, values that let you get the 802.11 header; 665 * selecting one of those values puts the adapter into monitor 666 * mode (i.e., you can't get 802.11 headers except in monitor 667 * mode, and you can't get Ethernet headers in monitor mode). 668 */ 669 if (uname(&osinfo) == -1) { 670 /* 671 * Can't get the OS version; just say "no". 672 */ 673 return (0); 674 } 675 /* 676 * We assume osinfo.sysname is "Darwin", because 677 * __APPLE__ is defined. We just check the version. 678 */ 679 if (osinfo.release[0] < '8' && osinfo.release[1] == '.') { 680 /* 681 * 10.3 (Darwin 7.x) or earlier. 682 * Monitor mode not supported. 683 */ 684 return (0); 685 } 686 if (osinfo.release[0] == '8' && osinfo.release[1] == '.') { 687 /* 688 * 10.4 (Darwin 8.x). s/en/wlt/, and check 689 * whether the device exists. 690 */ 691 if (strncmp(p->opt.source, "en", 2) != 0) { 692 /* 693 * Not an enN device; no monitor mode. 694 */ 695 return (0); 696 } 697 fd = socket(AF_INET, SOCK_DGRAM, 0); 698 if (fd == -1) { 699 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 700 "socket: %s", pcap_strerror(errno)); 701 return (PCAP_ERROR); 702 } 703 strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name)); 704 strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name)); 705 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { 706 /* 707 * No such device? 708 */ 709 close(fd); 710 return (0); 711 } 712 close(fd); 713 return (1); 714 } 715 716 #ifdef BIOCGDLTLIST 717 /* 718 * Everything else is 10.5 or later; for those, 719 * we just open the enN device, and check whether 720 * we have any 802.11 devices. 721 * 722 * First, open a BPF device. 723 */ 724 fd = bpf_open(p); 725 if (fd < 0) 726 return (fd); /* fd is the appropriate error code */ 727 728 /* 729 * Now bind to the device. 730 */ 731 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); 732 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { 733 switch (errno) { 734 735 case ENXIO: 736 /* 737 * There's no such device. 738 */ 739 close(fd); 740 return (PCAP_ERROR_NO_SUCH_DEVICE); 741 742 case ENETDOWN: 743 /* 744 * Return a "network down" indication, so that 745 * the application can report that rather than 746 * saying we had a mysterious failure and 747 * suggest that they report a problem to the 748 * libpcap developers. 749 */ 750 close(fd); 751 return (PCAP_ERROR_IFACE_NOT_UP); 752 753 default: 754 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 755 "BIOCSETIF: %s: %s", 756 p->opt.source, pcap_strerror(errno)); 757 close(fd); 758 return (PCAP_ERROR); 759 } 760 } 761 762 /* 763 * We know the default link type -- now determine all the DLTs 764 * this interface supports. If this fails with EINVAL, it's 765 * not fatal; we just don't get to use the feature later. 766 * (We don't care about DLT_DOCSIS, so we pass DLT_NULL 767 * as the default DLT for this adapter.) 768 */ 769 if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) { 770 close(fd); 771 return (PCAP_ERROR); 772 } 773 if (find_802_11(&bdl) != -1) { 774 /* 775 * We have an 802.11 DLT, so we can set monitor mode. 776 */ 777 free(bdl.bfl_list); 778 close(fd); 779 return (1); 780 } 781 free(bdl.bfl_list); 782 #endif /* BIOCGDLTLIST */ 783 return (0); 784 #elif defined(HAVE_BSD_IEEE80211) 785 int ret; 786 787 ret = monitor_mode(p, 0); 788 if (ret == PCAP_ERROR_RFMON_NOTSUP) 789 return (0); /* not an error, just a "can't do" */ 790 if (ret == 0) 791 return (1); /* success */ 792 return (ret); 793 #else 794 return (0); 795 #endif 796 } 797 798 static int 799 pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) 800 { 801 struct bpf_stat s; 802 803 /* 804 * "ps_recv" counts packets handed to the filter, not packets 805 * that passed the filter. This includes packets later dropped 806 * because we ran out of buffer space. 807 * 808 * "ps_drop" counts packets dropped inside the BPF device 809 * because we ran out of buffer space. It doesn't count 810 * packets dropped by the interface driver. It counts 811 * only packets that passed the filter. 812 * 813 * Both statistics include packets not yet read from the kernel 814 * by libpcap, and thus not yet seen by the application. 815 */ 816 if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) { 817 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s", 818 pcap_strerror(errno)); 819 return (PCAP_ERROR); 820 } 821 822 ps->ps_recv = s.bs_recv; 823 ps->ps_drop = s.bs_drop; 824 ps->ps_ifdrop = 0; 825 return (0); 826 } 827 828 static int 829 pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 830 { 831 struct pcap_bpf *pb = p->priv; 832 int cc; 833 int n = 0; 834 register u_char *bp, *ep; 835 u_char *datap; 836 #ifdef PCAP_FDDIPAD 837 register u_int pad; 838 #endif 839 #ifdef HAVE_ZEROCOPY_BPF 840 int i; 841 #endif 842 843 again: 844 /* 845 * Has "pcap_breakloop()" been called? 846 */ 847 if (p->break_loop) { 848 /* 849 * Yes - clear the flag that indicates that it 850 * has, and return PCAP_ERROR_BREAK to indicate 851 * that we were told to break out of the loop. 852 */ 853 p->break_loop = 0; 854 return (PCAP_ERROR_BREAK); 855 } 856 cc = p->cc; 857 if (p->cc == 0) { 858 /* 859 * When reading without zero-copy from a file descriptor, we 860 * use a single buffer and return a length of data in the 861 * buffer. With zero-copy, we update the p->buffer pointer 862 * to point at whatever underlying buffer contains the next 863 * data and update cc to reflect the data found in the 864 * buffer. 865 */ 866 #ifdef HAVE_ZEROCOPY_BPF 867 if (pb->zerocopy) { 868 if (p->buffer != NULL) 869 pcap_ack_zbuf(p); 870 i = pcap_next_zbuf(p, &cc); 871 if (i == 0) 872 goto again; 873 if (i < 0) 874 return (PCAP_ERROR); 875 } else 876 #endif 877 { 878 cc = read(p->fd, (char *)p->buffer, p->bufsize); 879 } 880 if (cc < 0) { 881 /* Don't choke when we get ptraced */ 882 switch (errno) { 883 884 case EINTR: 885 goto again; 886 887 #ifdef _AIX 888 case EFAULT: 889 /* 890 * Sigh. More AIX wonderfulness. 891 * 892 * For some unknown reason the uiomove() 893 * operation in the bpf kernel extension 894 * used to copy the buffer into user 895 * space sometimes returns EFAULT. I have 896 * no idea why this is the case given that 897 * a kernel debugger shows the user buffer 898 * is correct. This problem appears to 899 * be mostly mitigated by the memset of 900 * the buffer before it is first used. 901 * Very strange.... Shaun Clowes 902 * 903 * In any case this means that we shouldn't 904 * treat EFAULT as a fatal error; as we 905 * don't have an API for returning 906 * a "some packets were dropped since 907 * the last packet you saw" indication, 908 * we just ignore EFAULT and keep reading. 909 */ 910 goto again; 911 #endif 912 913 case EWOULDBLOCK: 914 return (0); 915 916 case ENXIO: 917 /* 918 * The device on which we're capturing 919 * went away. 920 * 921 * XXX - we should really return 922 * PCAP_ERROR_IFACE_NOT_UP, but 923 * pcap_dispatch() etc. aren't 924 * defined to retur that. 925 */ 926 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 927 "The interface went down"); 928 return (PCAP_ERROR); 929 930 #if defined(sun) && !defined(BSD) && !defined(__svr4__) && !defined(__SVR4) 931 /* 932 * Due to a SunOS bug, after 2^31 bytes, the kernel 933 * file offset overflows and read fails with EINVAL. 934 * The lseek() to 0 will fix things. 935 */ 936 case EINVAL: 937 if (lseek(p->fd, 0L, SEEK_CUR) + 938 p->bufsize < 0) { 939 (void)lseek(p->fd, 0L, SEEK_SET); 940 goto again; 941 } 942 /* fall through */ 943 #endif 944 } 945 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s", 946 pcap_strerror(errno)); 947 return (PCAP_ERROR); 948 } 949 bp = p->buffer; 950 } else 951 bp = p->bp; 952 953 /* 954 * Loop through each packet. 955 */ 956 #define bhp ((struct bpf_hdr *)bp) 957 ep = bp + cc; 958 #ifdef PCAP_FDDIPAD 959 pad = p->fddipad; 960 #endif 961 while (bp < ep) { 962 register u_int caplen, hdrlen; 963 964 /* 965 * Has "pcap_breakloop()" been called? 966 * If so, return immediately - if we haven't read any 967 * packets, clear the flag and return PCAP_ERROR_BREAK 968 * to indicate that we were told to break out of the loop, 969 * otherwise leave the flag set, so that the *next* call 970 * will break out of the loop without having read any 971 * packets, and return the number of packets we've 972 * processed so far. 973 */ 974 if (p->break_loop) { 975 p->bp = bp; 976 p->cc = ep - bp; 977 /* 978 * ep is set based on the return value of read(), 979 * but read() from a BPF device doesn't necessarily 980 * return a value that's a multiple of the alignment 981 * value for BPF_WORDALIGN(). However, whenever we 982 * increment bp, we round up the increment value by 983 * a value rounded up by BPF_WORDALIGN(), so we 984 * could increment bp past ep after processing the 985 * last packet in the buffer. 986 * 987 * We treat ep < bp as an indication that this 988 * happened, and just set p->cc to 0. 989 */ 990 if (p->cc < 0) 991 p->cc = 0; 992 if (n == 0) { 993 p->break_loop = 0; 994 return (PCAP_ERROR_BREAK); 995 } else 996 return (n); 997 } 998 999 caplen = bhp->bh_caplen; 1000 hdrlen = bhp->bh_hdrlen; 1001 datap = bp + hdrlen; 1002 /* 1003 * Short-circuit evaluation: if using BPF filter 1004 * in kernel, no need to do it now - we already know 1005 * the packet passed the filter. 1006 * 1007 #ifdef PCAP_FDDIPAD 1008 * Note: the filter code was generated assuming 1009 * that p->fddipad was the amount of padding 1010 * before the header, as that's what's required 1011 * in the kernel, so we run the filter before 1012 * skipping that padding. 1013 #endif 1014 */ 1015 if (pb->filtering_in_kernel || 1016 bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) { 1017 struct pcap_pkthdr pkthdr; 1018 1019 pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec; 1020 #ifdef _AIX 1021 /* 1022 * AIX's BPF returns seconds/nanoseconds time 1023 * stamps, not seconds/microseconds time stamps. 1024 */ 1025 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000; 1026 #else 1027 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec; 1028 #endif 1029 #ifdef PCAP_FDDIPAD 1030 if (caplen > pad) 1031 pkthdr.caplen = caplen - pad; 1032 else 1033 pkthdr.caplen = 0; 1034 if (bhp->bh_datalen > pad) 1035 pkthdr.len = bhp->bh_datalen - pad; 1036 else 1037 pkthdr.len = 0; 1038 datap += pad; 1039 #else 1040 pkthdr.caplen = caplen; 1041 pkthdr.len = bhp->bh_datalen; 1042 #endif 1043 (*callback)(user, &pkthdr, datap); 1044 bp += BPF_WORDALIGN(caplen + hdrlen); 1045 if (++n >= cnt && cnt > 0) { 1046 p->bp = bp; 1047 p->cc = ep - bp; 1048 /* 1049 * See comment above about p->cc < 0. 1050 */ 1051 if (p->cc < 0) 1052 p->cc = 0; 1053 return (n); 1054 } 1055 } else { 1056 /* 1057 * Skip this packet. 1058 */ 1059 bp += BPF_WORDALIGN(caplen + hdrlen); 1060 } 1061 } 1062 #undef bhp 1063 p->cc = 0; 1064 return (n); 1065 } 1066 1067 static int 1068 pcap_inject_bpf(pcap_t *p, const void *buf, size_t size) 1069 { 1070 int ret; 1071 1072 ret = write(p->fd, buf, size); 1073 #ifdef __APPLE__ 1074 if (ret == -1 && errno == EAFNOSUPPORT) { 1075 /* 1076 * In Mac OS X, there's a bug wherein setting the 1077 * BIOCSHDRCMPLT flag causes writes to fail; see, 1078 * for example: 1079 * 1080 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch 1081 * 1082 * So, if, on OS X, we get EAFNOSUPPORT from the write, we 1083 * assume it's due to that bug, and turn off that flag 1084 * and try again. If we succeed, it either means that 1085 * somebody applied the fix from that URL, or other patches 1086 * for that bug from 1087 * 1088 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/ 1089 * 1090 * and are running a Darwin kernel with those fixes, or 1091 * that Apple fixed the problem in some OS X release. 1092 */ 1093 u_int spoof_eth_src = 0; 1094 1095 if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 1096 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1097 "send: can't turn off BIOCSHDRCMPLT: %s", 1098 pcap_strerror(errno)); 1099 return (PCAP_ERROR); 1100 } 1101 1102 /* 1103 * Now try the write again. 1104 */ 1105 ret = write(p->fd, buf, size); 1106 } 1107 #endif /* __APPLE__ */ 1108 if (ret == -1) { 1109 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 1110 pcap_strerror(errno)); 1111 return (PCAP_ERROR); 1112 } 1113 return (ret); 1114 } 1115 1116 #ifdef _AIX 1117 static int 1118 bpf_odminit(char *errbuf) 1119 { 1120 char *errstr; 1121 1122 if (odm_initialize() == -1) { 1123 if (odm_err_msg(odmerrno, &errstr) == -1) 1124 errstr = "Unknown error"; 1125 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1126 "bpf_load: odm_initialize failed: %s", 1127 errstr); 1128 return (PCAP_ERROR); 1129 } 1130 1131 if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) { 1132 if (odm_err_msg(odmerrno, &errstr) == -1) 1133 errstr = "Unknown error"; 1134 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1135 "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s", 1136 errstr); 1137 (void)odm_terminate(); 1138 return (PCAP_ERROR); 1139 } 1140 1141 return (0); 1142 } 1143 1144 static int 1145 bpf_odmcleanup(char *errbuf) 1146 { 1147 char *errstr; 1148 1149 if (odm_unlock(odmlockid) == -1) { 1150 if (errbuf != NULL) { 1151 if (odm_err_msg(odmerrno, &errstr) == -1) 1152 errstr = "Unknown error"; 1153 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1154 "bpf_load: odm_unlock failed: %s", 1155 errstr); 1156 } 1157 return (PCAP_ERROR); 1158 } 1159 1160 if (odm_terminate() == -1) { 1161 if (errbuf != NULL) { 1162 if (odm_err_msg(odmerrno, &errstr) == -1) 1163 errstr = "Unknown error"; 1164 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1165 "bpf_load: odm_terminate failed: %s", 1166 errstr); 1167 } 1168 return (PCAP_ERROR); 1169 } 1170 1171 return (0); 1172 } 1173 1174 static int 1175 bpf_load(char *errbuf) 1176 { 1177 long major; 1178 int *minors; 1179 int numminors, i, rc; 1180 char buf[1024]; 1181 struct stat sbuf; 1182 struct bpf_config cfg_bpf; 1183 struct cfg_load cfg_ld; 1184 struct cfg_kmod cfg_km; 1185 1186 /* 1187 * This is very very close to what happens in the real implementation 1188 * but I've fixed some (unlikely) bug situations. 1189 */ 1190 if (bpfloadedflag) 1191 return (0); 1192 1193 if (bpf_odminit(errbuf) == PCAP_ERROR) 1194 return (PCAP_ERROR); 1195 1196 major = genmajor(BPF_NAME); 1197 if (major == -1) { 1198 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1199 "bpf_load: genmajor failed: %s", pcap_strerror(errno)); 1200 (void)bpf_odmcleanup(NULL); 1201 return (PCAP_ERROR); 1202 } 1203 1204 minors = getminor(major, &numminors, BPF_NAME); 1205 if (!minors) { 1206 minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1); 1207 if (!minors) { 1208 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1209 "bpf_load: genminor failed: %s", 1210 pcap_strerror(errno)); 1211 (void)bpf_odmcleanup(NULL); 1212 return (PCAP_ERROR); 1213 } 1214 } 1215 1216 if (bpf_odmcleanup(errbuf) == PCAP_ERROR) 1217 return (PCAP_ERROR); 1218 1219 rc = stat(BPF_NODE "0", &sbuf); 1220 if (rc == -1 && errno != ENOENT) { 1221 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1222 "bpf_load: can't stat %s: %s", 1223 BPF_NODE "0", pcap_strerror(errno)); 1224 return (PCAP_ERROR); 1225 } 1226 1227 if (rc == -1 || getmajor(sbuf.st_rdev) != major) { 1228 for (i = 0; i < BPF_MINORS; i++) { 1229 sprintf(buf, "%s%d", BPF_NODE, i); 1230 unlink(buf); 1231 if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) { 1232 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1233 "bpf_load: can't mknod %s: %s", 1234 buf, pcap_strerror(errno)); 1235 return (PCAP_ERROR); 1236 } 1237 } 1238 } 1239 1240 /* Check if the driver is loaded */ 1241 memset(&cfg_ld, 0x0, sizeof(cfg_ld)); 1242 cfg_ld.path = buf; 1243 sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME); 1244 if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) || 1245 (cfg_ld.kmid == 0)) { 1246 /* Driver isn't loaded, load it now */ 1247 if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) { 1248 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1249 "bpf_load: could not load driver: %s", 1250 strerror(errno)); 1251 return (PCAP_ERROR); 1252 } 1253 } 1254 1255 /* Configure the driver */ 1256 cfg_km.cmd = CFG_INIT; 1257 cfg_km.kmid = cfg_ld.kmid; 1258 cfg_km.mdilen = sizeof(cfg_bpf); 1259 cfg_km.mdiptr = (void *)&cfg_bpf; 1260 for (i = 0; i < BPF_MINORS; i++) { 1261 cfg_bpf.devno = domakedev(major, i); 1262 if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) { 1263 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1264 "bpf_load: could not configure driver: %s", 1265 strerror(errno)); 1266 return (PCAP_ERROR); 1267 } 1268 } 1269 1270 bpfloadedflag = 1; 1271 1272 return (0); 1273 } 1274 #endif 1275 1276 /* 1277 * Turn off rfmon mode if necessary. 1278 */ 1279 static void 1280 pcap_cleanup_bpf(pcap_t *p) 1281 { 1282 struct pcap_bpf *pb = p->priv; 1283 #ifdef HAVE_BSD_IEEE80211 1284 int sock; 1285 struct ifmediareq req; 1286 struct ifreq ifr; 1287 #endif 1288 1289 if (pb->must_do_on_close != 0) { 1290 /* 1291 * There's something we have to do when closing this 1292 * pcap_t. 1293 */ 1294 #ifdef HAVE_BSD_IEEE80211 1295 if (pb->must_do_on_close & MUST_CLEAR_RFMON) { 1296 /* 1297 * We put the interface into rfmon mode; 1298 * take it out of rfmon mode. 1299 * 1300 * XXX - if somebody else wants it in rfmon 1301 * mode, this code cannot know that, so it'll take 1302 * it out of rfmon mode. 1303 */ 1304 sock = socket(AF_INET, SOCK_DGRAM, 0); 1305 if (sock == -1) { 1306 fprintf(stderr, 1307 "Can't restore interface flags (socket() failed: %s).\n" 1308 "Please adjust manually.\n", 1309 strerror(errno)); 1310 } else { 1311 memset(&req, 0, sizeof(req)); 1312 strncpy(req.ifm_name, pb->device, 1313 sizeof(req.ifm_name)); 1314 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 1315 fprintf(stderr, 1316 "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n" 1317 "Please adjust manually.\n", 1318 strerror(errno)); 1319 } else { 1320 if (req.ifm_current & IFM_IEEE80211_MONITOR) { 1321 /* 1322 * Rfmon mode is currently on; 1323 * turn it off. 1324 */ 1325 memset(&ifr, 0, sizeof(ifr)); 1326 (void)strncpy(ifr.ifr_name, 1327 pb->device, 1328 sizeof(ifr.ifr_name)); 1329 ifr.ifr_media = 1330 req.ifm_current & ~IFM_IEEE80211_MONITOR; 1331 if (ioctl(sock, SIOCSIFMEDIA, 1332 &ifr) == -1) { 1333 fprintf(stderr, 1334 "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n" 1335 "Please adjust manually.\n", 1336 strerror(errno)); 1337 } 1338 } 1339 } 1340 close(sock); 1341 } 1342 } 1343 #endif /* HAVE_BSD_IEEE80211 */ 1344 1345 /* 1346 * Take this pcap out of the list of pcaps for which we 1347 * have to take the interface out of some mode. 1348 */ 1349 pcap_remove_from_pcaps_to_close(p); 1350 pb->must_do_on_close = 0; 1351 } 1352 1353 #ifdef HAVE_ZEROCOPY_BPF 1354 if (pb->zerocopy) { 1355 /* 1356 * Delete the mappings. Note that p->buffer gets 1357 * initialized to one of the mmapped regions in 1358 * this case, so do not try and free it directly; 1359 * null it out so that pcap_cleanup_live_common() 1360 * doesn't try to free it. 1361 */ 1362 if (pb->zbuf1 != MAP_FAILED && pb->zbuf1 != NULL) 1363 (void) munmap(pb->zbuf1, pb->zbufsize); 1364 if (pb->zbuf2 != MAP_FAILED && pb->zbuf2 != NULL) 1365 (void) munmap(pb->zbuf2, pb->zbufsize); 1366 p->buffer = NULL; 1367 } 1368 #endif 1369 if (pb->device != NULL) { 1370 free(pb->device); 1371 pb->device = NULL; 1372 } 1373 pcap_cleanup_live_common(p); 1374 } 1375 1376 static int 1377 check_setif_failure(pcap_t *p, int error) 1378 { 1379 #ifdef __APPLE__ 1380 int fd; 1381 struct ifreq ifr; 1382 int err; 1383 #endif 1384 1385 if (error == ENXIO) { 1386 /* 1387 * No such device exists. 1388 */ 1389 #ifdef __APPLE__ 1390 if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) { 1391 /* 1392 * Monitor mode was requested, and we're trying 1393 * to open a "wltN" device. Assume that this 1394 * is 10.4 and that we were asked to open an 1395 * "enN" device; if that device exists, return 1396 * "monitor mode not supported on the device". 1397 */ 1398 fd = socket(AF_INET, SOCK_DGRAM, 0); 1399 if (fd != -1) { 1400 strlcpy(ifr.ifr_name, "en", 1401 sizeof(ifr.ifr_name)); 1402 strlcat(ifr.ifr_name, p->opt.source + 3, 1403 sizeof(ifr.ifr_name)); 1404 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { 1405 /* 1406 * We assume this failed because 1407 * the underlying device doesn't 1408 * exist. 1409 */ 1410 err = PCAP_ERROR_NO_SUCH_DEVICE; 1411 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1412 "SIOCGIFFLAGS on %s failed: %s", 1413 ifr.ifr_name, pcap_strerror(errno)); 1414 } else { 1415 /* 1416 * The underlying "enN" device 1417 * exists, but there's no 1418 * corresponding "wltN" device; 1419 * that means that the "enN" 1420 * device doesn't support 1421 * monitor mode, probably because 1422 * it's an Ethernet device rather 1423 * than a wireless device. 1424 */ 1425 err = PCAP_ERROR_RFMON_NOTSUP; 1426 } 1427 close(fd); 1428 } else { 1429 /* 1430 * We can't find out whether there's 1431 * an underlying "enN" device, so 1432 * just report "no such device". 1433 */ 1434 err = PCAP_ERROR_NO_SUCH_DEVICE; 1435 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1436 "socket() failed: %s", 1437 pcap_strerror(errno)); 1438 } 1439 return (err); 1440 } 1441 #endif 1442 /* 1443 * No such device. 1444 */ 1445 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF failed: %s", 1446 pcap_strerror(errno)); 1447 return (PCAP_ERROR_NO_SUCH_DEVICE); 1448 } else if (errno == ENETDOWN) { 1449 /* 1450 * Return a "network down" indication, so that 1451 * the application can report that rather than 1452 * saying we had a mysterious failure and 1453 * suggest that they report a problem to the 1454 * libpcap developers. 1455 */ 1456 return (PCAP_ERROR_IFACE_NOT_UP); 1457 } else { 1458 /* 1459 * Some other error; fill in the error string, and 1460 * return PCAP_ERROR. 1461 */ 1462 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", 1463 p->opt.source, pcap_strerror(errno)); 1464 return (PCAP_ERROR); 1465 } 1466 } 1467 1468 /* 1469 * Default capture buffer size. 1470 * 32K isn't very much for modern machines with fast networks; we 1471 * pick .5M, as that's the maximum on at least some systems with BPF. 1472 * 1473 * However, on AIX 3.5, the larger buffer sized caused unrecoverable 1474 * read failures under stress, so we leave it as 32K; yet another 1475 * place where AIX's BPF is broken. 1476 */ 1477 #ifdef _AIX 1478 #define DEFAULT_BUFSIZE 32768 1479 #else 1480 #define DEFAULT_BUFSIZE 524288 1481 #endif 1482 1483 static int 1484 pcap_activate_bpf(pcap_t *p) 1485 { 1486 struct pcap_bpf *pb = p->priv; 1487 int status = 0; 1488 int fd; 1489 #ifdef LIFNAMSIZ 1490 char *zonesep; 1491 struct lifreq ifr; 1492 char *ifrname = ifr.lifr_name; 1493 const size_t ifnamsiz = sizeof(ifr.lifr_name); 1494 #else 1495 struct ifreq ifr; 1496 char *ifrname = ifr.ifr_name; 1497 const size_t ifnamsiz = sizeof(ifr.ifr_name); 1498 #endif 1499 struct bpf_version bv; 1500 #ifdef __APPLE__ 1501 int sockfd; 1502 char *wltdev = NULL; 1503 #endif 1504 #ifdef BIOCGDLTLIST 1505 struct bpf_dltlist bdl; 1506 #if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 1507 u_int new_dlt; 1508 #endif 1509 #endif /* BIOCGDLTLIST */ 1510 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 1511 u_int spoof_eth_src = 1; 1512 #endif 1513 u_int v; 1514 struct bpf_insn total_insn; 1515 struct bpf_program total_prog; 1516 struct utsname osinfo; 1517 int have_osinfo = 0; 1518 #ifdef HAVE_ZEROCOPY_BPF 1519 struct bpf_zbuf bz; 1520 u_int bufmode, zbufmax; 1521 #endif 1522 1523 fd = bpf_open(p); 1524 if (fd < 0) { 1525 status = fd; 1526 goto bad; 1527 } 1528 1529 p->fd = fd; 1530 1531 if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) { 1532 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s", 1533 pcap_strerror(errno)); 1534 status = PCAP_ERROR; 1535 goto bad; 1536 } 1537 if (bv.bv_major != BPF_MAJOR_VERSION || 1538 bv.bv_minor < BPF_MINOR_VERSION) { 1539 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1540 "kernel bpf filter out of date"); 1541 status = PCAP_ERROR; 1542 goto bad; 1543 } 1544 1545 #if defined(LIFNAMSIZ) && defined(ZONENAME_MAX) && defined(lifr_zoneid) 1546 /* 1547 * Check if the given source network device has a '/' separated 1548 * zonename prefix string. The zonename prefixed source device 1549 * can be used by libpcap consumers to capture network traffic 1550 * in non-global zones from the global zone on Solaris 11 and 1551 * above. If the zonename prefix is present then we strip the 1552 * prefix and pass the zone ID as part of lifr_zoneid. 1553 */ 1554 if ((zonesep = strchr(p->opt.source, '/')) != NULL) { 1555 char zonename[ZONENAME_MAX]; 1556 int znamelen; 1557 char *lnamep; 1558 1559 znamelen = zonesep - p->opt.source; 1560 (void) strlcpy(zonename, p->opt.source, znamelen + 1); 1561 lnamep = strdup(zonesep + 1); 1562 ifr.lifr_zoneid = getzoneidbyname(zonename); 1563 free(p->opt.source); 1564 p->opt.source = lnamep; 1565 } 1566 #endif 1567 1568 pb->device = strdup(p->opt.source); 1569 if (pb->device == NULL) { 1570 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s", 1571 pcap_strerror(errno)); 1572 status = PCAP_ERROR; 1573 goto bad; 1574 } 1575 1576 /* 1577 * Attempt to find out the version of the OS on which we're running. 1578 */ 1579 if (uname(&osinfo) == 0) 1580 have_osinfo = 1; 1581 1582 #ifdef __APPLE__ 1583 /* 1584 * See comment in pcap_can_set_rfmon_bpf() for an explanation 1585 * of why we check the version number. 1586 */ 1587 if (p->opt.rfmon) { 1588 if (have_osinfo) { 1589 /* 1590 * We assume osinfo.sysname is "Darwin", because 1591 * __APPLE__ is defined. We just check the version. 1592 */ 1593 if (osinfo.release[0] < '8' && 1594 osinfo.release[1] == '.') { 1595 /* 1596 * 10.3 (Darwin 7.x) or earlier. 1597 */ 1598 status = PCAP_ERROR_RFMON_NOTSUP; 1599 goto bad; 1600 } 1601 if (osinfo.release[0] == '8' && 1602 osinfo.release[1] == '.') { 1603 /* 1604 * 10.4 (Darwin 8.x). s/en/wlt/ 1605 */ 1606 if (strncmp(p->opt.source, "en", 2) != 0) { 1607 /* 1608 * Not an enN device; check 1609 * whether the device even exists. 1610 */ 1611 sockfd = socket(AF_INET, SOCK_DGRAM, 0); 1612 if (sockfd != -1) { 1613 strlcpy(ifrname, 1614 p->opt.source, ifnamsiz); 1615 if (ioctl(sockfd, SIOCGIFFLAGS, 1616 (char *)&ifr) < 0) { 1617 /* 1618 * We assume this 1619 * failed because 1620 * the underlying 1621 * device doesn't 1622 * exist. 1623 */ 1624 status = PCAP_ERROR_NO_SUCH_DEVICE; 1625 snprintf(p->errbuf, 1626 PCAP_ERRBUF_SIZE, 1627 "SIOCGIFFLAGS failed: %s", 1628 pcap_strerror(errno)); 1629 } else 1630 status = PCAP_ERROR_RFMON_NOTSUP; 1631 close(sockfd); 1632 } else { 1633 /* 1634 * We can't find out whether 1635 * the device exists, so just 1636 * report "no such device". 1637 */ 1638 status = PCAP_ERROR_NO_SUCH_DEVICE; 1639 snprintf(p->errbuf, 1640 PCAP_ERRBUF_SIZE, 1641 "socket() failed: %s", 1642 pcap_strerror(errno)); 1643 } 1644 goto bad; 1645 } 1646 wltdev = malloc(strlen(p->opt.source) + 2); 1647 if (wltdev == NULL) { 1648 (void)snprintf(p->errbuf, 1649 PCAP_ERRBUF_SIZE, "malloc: %s", 1650 pcap_strerror(errno)); 1651 status = PCAP_ERROR; 1652 goto bad; 1653 } 1654 strcpy(wltdev, "wlt"); 1655 strcat(wltdev, p->opt.source + 2); 1656 free(p->opt.source); 1657 p->opt.source = wltdev; 1658 } 1659 /* 1660 * Everything else is 10.5 or later; for those, 1661 * we just open the enN device, and set the DLT. 1662 */ 1663 } 1664 } 1665 #endif /* __APPLE__ */ 1666 #ifdef HAVE_ZEROCOPY_BPF 1667 /* 1668 * If the BPF extension to set buffer mode is present, try setting 1669 * the mode to zero-copy. If that fails, use regular buffering. If 1670 * it succeeds but other setup fails, return an error to the user. 1671 */ 1672 bufmode = BPF_BUFMODE_ZBUF; 1673 if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) { 1674 /* 1675 * We have zerocopy BPF; use it. 1676 */ 1677 pb->zerocopy = 1; 1678 1679 /* 1680 * How to pick a buffer size: first, query the maximum buffer 1681 * size supported by zero-copy. This also lets us quickly 1682 * determine whether the kernel generally supports zero-copy. 1683 * Then, if a buffer size was specified, use that, otherwise 1684 * query the default buffer size, which reflects kernel 1685 * policy for a desired default. Round to the nearest page 1686 * size. 1687 */ 1688 if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) { 1689 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s", 1690 pcap_strerror(errno)); 1691 goto bad; 1692 } 1693 1694 if (p->opt.buffer_size != 0) { 1695 /* 1696 * A buffer size was explicitly specified; use it. 1697 */ 1698 v = p->opt.buffer_size; 1699 } else { 1700 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 1701 v < DEFAULT_BUFSIZE) 1702 v = DEFAULT_BUFSIZE; 1703 } 1704 #ifndef roundup 1705 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 1706 #endif 1707 pb->zbufsize = roundup(v, getpagesize()); 1708 if (pb->zbufsize > zbufmax) 1709 pb->zbufsize = zbufmax; 1710 pb->zbuf1 = mmap(NULL, pb->zbufsize, PROT_READ | PROT_WRITE, 1711 MAP_ANON, -1, 0); 1712 pb->zbuf2 = mmap(NULL, pb->zbufsize, PROT_READ | PROT_WRITE, 1713 MAP_ANON, -1, 0); 1714 if (pb->zbuf1 == MAP_FAILED || pb->zbuf2 == MAP_FAILED) { 1715 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s", 1716 pcap_strerror(errno)); 1717 goto bad; 1718 } 1719 memset(&bz, 0, sizeof(bz)); /* bzero() deprecated, replaced with memset() */ 1720 bz.bz_bufa = pb->zbuf1; 1721 bz.bz_bufb = pb->zbuf2; 1722 bz.bz_buflen = pb->zbufsize; 1723 if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) { 1724 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s", 1725 pcap_strerror(errno)); 1726 goto bad; 1727 } 1728 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1729 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { 1730 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", 1731 p->opt.source, pcap_strerror(errno)); 1732 goto bad; 1733 } 1734 v = pb->zbufsize - sizeof(struct bpf_zbuf_header); 1735 } else 1736 #endif 1737 { 1738 /* 1739 * We don't have zerocopy BPF. 1740 * Set the buffer size. 1741 */ 1742 if (p->opt.buffer_size != 0) { 1743 /* 1744 * A buffer size was explicitly specified; use it. 1745 */ 1746 if (ioctl(fd, BIOCSBLEN, 1747 (caddr_t)&p->opt.buffer_size) < 0) { 1748 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1749 "BIOCSBLEN: %s: %s", p->opt.source, 1750 pcap_strerror(errno)); 1751 status = PCAP_ERROR; 1752 goto bad; 1753 } 1754 1755 /* 1756 * Now bind to the device. 1757 */ 1758 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1759 #ifdef BIOCSETLIF 1760 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) < 0) 1761 #else 1762 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) 1763 #endif 1764 { 1765 status = check_setif_failure(p, errno); 1766 goto bad; 1767 } 1768 } else { 1769 /* 1770 * No buffer size was explicitly specified. 1771 * 1772 * Try finding a good size for the buffer; 1773 * DEFAULT_BUFSIZE may be too big, so keep 1774 * cutting it in half until we find a size 1775 * that works, or run out of sizes to try. 1776 * If the default is larger, don't make it smaller. 1777 */ 1778 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 1779 v < DEFAULT_BUFSIZE) 1780 v = DEFAULT_BUFSIZE; 1781 for ( ; v != 0; v >>= 1) { 1782 /* 1783 * Ignore the return value - this is because the 1784 * call fails on BPF systems that don't have 1785 * kernel malloc. And if the call fails, it's 1786 * no big deal, we just continue to use the 1787 * standard buffer size. 1788 */ 1789 (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v); 1790 1791 (void)strncpy(ifrname, p->opt.source, ifnamsiz); 1792 #ifdef BIOCSETLIF 1793 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) >= 0) 1794 #else 1795 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0) 1796 #endif 1797 break; /* that size worked; we're done */ 1798 1799 if (errno != ENOBUFS) { 1800 status = check_setif_failure(p, errno); 1801 goto bad; 1802 } 1803 } 1804 1805 if (v == 0) { 1806 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1807 "BIOCSBLEN: %s: No buffer size worked", 1808 p->opt.source); 1809 status = PCAP_ERROR; 1810 goto bad; 1811 } 1812 } 1813 } 1814 1815 /* Get the data link layer type. */ 1816 if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) { 1817 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s", 1818 pcap_strerror(errno)); 1819 status = PCAP_ERROR; 1820 goto bad; 1821 } 1822 1823 #ifdef _AIX 1824 /* 1825 * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT. 1826 */ 1827 switch (v) { 1828 1829 case IFT_ETHER: 1830 case IFT_ISO88023: 1831 v = DLT_EN10MB; 1832 break; 1833 1834 case IFT_FDDI: 1835 v = DLT_FDDI; 1836 break; 1837 1838 case IFT_ISO88025: 1839 v = DLT_IEEE802; 1840 break; 1841 1842 case IFT_LOOP: 1843 v = DLT_NULL; 1844 break; 1845 1846 default: 1847 /* 1848 * We don't know what to map this to yet. 1849 */ 1850 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", 1851 v); 1852 status = PCAP_ERROR; 1853 goto bad; 1854 } 1855 #endif 1856 #if _BSDI_VERSION - 0 >= 199510 1857 /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */ 1858 switch (v) { 1859 1860 case DLT_SLIP: 1861 v = DLT_SLIP_BSDOS; 1862 break; 1863 1864 case DLT_PPP: 1865 v = DLT_PPP_BSDOS; 1866 break; 1867 1868 case 11: /*DLT_FR*/ 1869 v = DLT_FRELAY; 1870 break; 1871 1872 case 12: /*DLT_C_HDLC*/ 1873 v = DLT_CHDLC; 1874 break; 1875 } 1876 #endif 1877 1878 #ifdef BIOCGDLTLIST 1879 /* 1880 * We know the default link type -- now determine all the DLTs 1881 * this interface supports. If this fails with EINVAL, it's 1882 * not fatal; we just don't get to use the feature later. 1883 */ 1884 if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) { 1885 status = PCAP_ERROR; 1886 goto bad; 1887 } 1888 p->dlt_count = bdl.bfl_len; 1889 p->dlt_list = bdl.bfl_list; 1890 1891 #ifdef __APPLE__ 1892 /* 1893 * Monitor mode fun, continued. 1894 * 1895 * For 10.5 and, we're assuming, later releases, as noted above, 1896 * 802.1 adapters that support monitor mode offer both DLT_EN10MB, 1897 * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information 1898 * DLT_ value. Choosing one of the 802.11 DLT_ values will turn 1899 * monitor mode on. 1900 * 1901 * Therefore, if the user asked for monitor mode, we filter out 1902 * the DLT_EN10MB value, as you can't get that in monitor mode, 1903 * and, if the user didn't ask for monitor mode, we filter out 1904 * the 802.11 DLT_ values, because selecting those will turn 1905 * monitor mode on. Then, for monitor mode, if an 802.11-plus- 1906 * radio DLT_ value is offered, we try to select that, otherwise 1907 * we try to select DLT_IEEE802_11. 1908 */ 1909 if (have_osinfo) { 1910 if (isdigit((unsigned)osinfo.release[0]) && 1911 (osinfo.release[0] == '9' || 1912 isdigit((unsigned)osinfo.release[1]))) { 1913 /* 1914 * 10.5 (Darwin 9.x), or later. 1915 */ 1916 new_dlt = find_802_11(&bdl); 1917 if (new_dlt != -1) { 1918 /* 1919 * We have at least one 802.11 DLT_ value, 1920 * so this is an 802.11 interface. 1921 * new_dlt is the best of the 802.11 1922 * DLT_ values in the list. 1923 */ 1924 if (p->opt.rfmon) { 1925 /* 1926 * Our caller wants monitor mode. 1927 * Purge DLT_EN10MB from the list 1928 * of link-layer types, as selecting 1929 * it will keep monitor mode off. 1930 */ 1931 remove_en(p); 1932 1933 /* 1934 * If the new mode we want isn't 1935 * the default mode, attempt to 1936 * select the new mode. 1937 */ 1938 if (new_dlt != v) { 1939 if (ioctl(p->fd, BIOCSDLT, 1940 &new_dlt) != -1) { 1941 /* 1942 * We succeeded; 1943 * make this the 1944 * new DLT_ value. 1945 */ 1946 v = new_dlt; 1947 } 1948 } 1949 } else { 1950 /* 1951 * Our caller doesn't want 1952 * monitor mode. Unless this 1953 * is being done by pcap_open_live(), 1954 * purge the 802.11 link-layer types 1955 * from the list, as selecting 1956 * one of them will turn monitor 1957 * mode on. 1958 */ 1959 if (!p->oldstyle) 1960 remove_802_11(p); 1961 } 1962 } else { 1963 if (p->opt.rfmon) { 1964 /* 1965 * The caller requested monitor 1966 * mode, but we have no 802.11 1967 * link-layer types, so they 1968 * can't have it. 1969 */ 1970 status = PCAP_ERROR_RFMON_NOTSUP; 1971 goto bad; 1972 } 1973 } 1974 } 1975 } 1976 #elif defined(HAVE_BSD_IEEE80211) 1977 /* 1978 * *BSD with the new 802.11 ioctls. 1979 * Do we want monitor mode? 1980 */ 1981 if (p->opt.rfmon) { 1982 /* 1983 * Try to put the interface into monitor mode. 1984 */ 1985 status = monitor_mode(p, 1); 1986 if (status != 0) { 1987 /* 1988 * We failed. 1989 */ 1990 goto bad; 1991 } 1992 1993 /* 1994 * We're in monitor mode. 1995 * Try to find the best 802.11 DLT_ value and, if we 1996 * succeed, try to switch to that mode if we're not 1997 * already in that mode. 1998 */ 1999 new_dlt = find_802_11(&bdl); 2000 if (new_dlt != (unsigned)-1) { 2001 /* 2002 * We have at least one 802.11 DLT_ value. 2003 * new_dlt is the best of the 802.11 2004 * DLT_ values in the list. 2005 * 2006 * If the new mode we want isn't the default mode, 2007 * attempt to select the new mode. 2008 */ 2009 if (new_dlt != v) { 2010 if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) { 2011 /* 2012 * We succeeded; make this the 2013 * new DLT_ value. 2014 */ 2015 v = new_dlt; 2016 } 2017 } 2018 } 2019 } 2020 #endif /* various platforms */ 2021 #endif /* BIOCGDLTLIST */ 2022 2023 /* 2024 * If this is an Ethernet device, and we don't have a DLT_ list, 2025 * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give 2026 * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to 2027 * do, but there's not much we can do about that without finding 2028 * some other way of determining whether it's an Ethernet or 802.11 2029 * device.) 2030 */ 2031 if (v == DLT_EN10MB && p->dlt_count == 0) { 2032 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 2033 /* 2034 * If that fails, just leave the list empty. 2035 */ 2036 if (p->dlt_list != NULL) { 2037 p->dlt_list[0] = DLT_EN10MB; 2038 p->dlt_list[1] = DLT_DOCSIS; 2039 p->dlt_count = 2; 2040 } 2041 } 2042 #ifdef PCAP_FDDIPAD 2043 if (v == DLT_FDDI) 2044 p->fddipad = PCAP_FDDIPAD; 2045 else 2046 #endif 2047 p->fddipad = 0; 2048 p->linktype = v; 2049 2050 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 2051 /* 2052 * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so 2053 * the link-layer source address isn't forcibly overwritten. 2054 * (Should we ignore errors? Should we do this only if 2055 * we're open for writing?) 2056 * 2057 * XXX - I seem to remember some packet-sending bug in some 2058 * BSDs - check CVS log for "bpf.c"? 2059 */ 2060 if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 2061 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2062 "BIOCSHDRCMPLT: %s", pcap_strerror(errno)); 2063 status = PCAP_ERROR; 2064 goto bad; 2065 } 2066 #endif 2067 /* set timeout */ 2068 #ifdef HAVE_ZEROCOPY_BPF 2069 /* 2070 * In zero-copy mode, we just use the timeout in select(). 2071 * XXX - what if we're in non-blocking mode and the *application* 2072 * is using select() or poll() or kqueues or....? 2073 */ 2074 if (p->opt.timeout && !pb->zerocopy) { 2075 #else 2076 if (p->opt.timeout) { 2077 #endif 2078 /* 2079 * XXX - is this seconds/nanoseconds in AIX? 2080 * (Treating it as such doesn't fix the timeout 2081 * problem described below.) 2082 * 2083 * XXX - Mac OS X 10.6 mishandles BIOCSRTIMEOUT in 2084 * 64-bit userland - it takes, as an argument, a 2085 * "struct BPF_TIMEVAL", which has 32-bit tv_sec 2086 * and tv_usec, rather than a "struct timeval". 2087 * 2088 * If this platform defines "struct BPF_TIMEVAL", 2089 * we check whether the structure size in BIOCSRTIMEOUT 2090 * is that of a "struct timeval" and, if not, we use 2091 * a "struct BPF_TIMEVAL" rather than a "struct timeval". 2092 * (That way, if the bug is fixed in a future release, 2093 * we will still do the right thing.) 2094 */ 2095 struct timeval to; 2096 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2097 struct BPF_TIMEVAL bpf_to; 2098 2099 if (IOCPARM_LEN(BIOCSRTIMEOUT) != sizeof(struct timeval)) { 2100 bpf_to.tv_sec = p->opt.timeout / 1000; 2101 bpf_to.tv_usec = (p->opt.timeout * 1000) % 1000000; 2102 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&bpf_to) < 0) { 2103 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2104 "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); 2105 status = PCAP_ERROR; 2106 goto bad; 2107 } 2108 } else { 2109 #endif 2110 to.tv_sec = p->opt.timeout / 1000; 2111 to.tv_usec = (p->opt.timeout * 1000) % 1000000; 2112 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) { 2113 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2114 "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); 2115 status = PCAP_ERROR; 2116 goto bad; 2117 } 2118 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2119 } 2120 #endif 2121 } 2122 2123 #ifdef BIOCIMMEDIATE 2124 /* 2125 * Darren Reed notes that 2126 * 2127 * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the 2128 * timeout appears to be ignored and it waits until the buffer 2129 * is filled before returning. The result of not having it 2130 * set is almost worse than useless if your BPF filter 2131 * is reducing things to only a few packets (i.e. one every 2132 * second or so). 2133 * 2134 * so we always turn BIOCIMMEDIATE mode on if this is AIX. 2135 * 2136 * For other platforms, we don't turn immediate mode on by default, 2137 * as that would mean we get woken up for every packet, which 2138 * probably isn't what you want for a packet sniffer. 2139 * 2140 * We set immediate mode if the caller requested it by calling 2141 * pcap_set_immediate() before calling pcap_activate(). 2142 */ 2143 #ifndef _AIX 2144 if (p->opt.immediate) { 2145 #endif /* _AIX */ 2146 v = 1; 2147 if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) { 2148 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2149 "BIOCIMMEDIATE: %s", pcap_strerror(errno)); 2150 status = PCAP_ERROR; 2151 goto bad; 2152 } 2153 #ifndef _AIX 2154 } 2155 #endif /* _AIX */ 2156 #else /* BIOCIMMEDIATE */ 2157 if (p->opt.immediate) { 2158 /* 2159 * We don't support immediate mode. Fail. 2160 */ 2161 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Immediate mode not supported"); 2162 status = PCAP_ERROR; 2163 goto bad; 2164 } 2165 #endif /* BIOCIMMEDIATE */ 2166 2167 if (p->opt.promisc) { 2168 /* set promiscuous mode, just warn if it fails */ 2169 if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) { 2170 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s", 2171 pcap_strerror(errno)); 2172 status = PCAP_WARNING_PROMISC_NOTSUP; 2173 } 2174 } 2175 2176 if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) { 2177 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s", 2178 pcap_strerror(errno)); 2179 status = PCAP_ERROR; 2180 goto bad; 2181 } 2182 p->bufsize = v; 2183 #ifdef HAVE_ZEROCOPY_BPF 2184 if (!pb->zerocopy) { 2185 #endif 2186 p->buffer = (u_char *)malloc(p->bufsize); 2187 if (p->buffer == NULL) { 2188 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", 2189 pcap_strerror(errno)); 2190 status = PCAP_ERROR; 2191 goto bad; 2192 } 2193 #ifdef _AIX 2194 /* For some strange reason this seems to prevent the EFAULT 2195 * problems we have experienced from AIX BPF. */ 2196 memset(p->buffer, 0x0, p->bufsize); 2197 #endif 2198 #ifdef HAVE_ZEROCOPY_BPF 2199 } 2200 #endif 2201 2202 /* 2203 * If there's no filter program installed, there's 2204 * no indication to the kernel of what the snapshot 2205 * length should be, so no snapshotting is done. 2206 * 2207 * Therefore, when we open the device, we install 2208 * an "accept everything" filter with the specified 2209 * snapshot length. 2210 */ 2211 total_insn.code = (u_short)(BPF_RET | BPF_K); 2212 total_insn.jt = 0; 2213 total_insn.jf = 0; 2214 total_insn.k = p->snapshot; 2215 2216 total_prog.bf_len = 1; 2217 total_prog.bf_insns = &total_insn; 2218 if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) { 2219 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", 2220 pcap_strerror(errno)); 2221 status = PCAP_ERROR; 2222 goto bad; 2223 } 2224 2225 /* 2226 * On most BPF platforms, either you can do a "select()" or 2227 * "poll()" on a BPF file descriptor and it works correctly, 2228 * or you can do it and it will return "readable" if the 2229 * hold buffer is full but not if the timeout expires *and* 2230 * a non-blocking read will, if the hold buffer is empty 2231 * but the store buffer isn't empty, rotate the buffers 2232 * and return what packets are available. 2233 * 2234 * In the latter case, the fact that a non-blocking read 2235 * will give you the available packets means you can work 2236 * around the failure of "select()" and "poll()" to wake up 2237 * and return "readable" when the timeout expires by using 2238 * the timeout as the "select()" or "poll()" timeout, putting 2239 * the BPF descriptor into non-blocking mode, and read from 2240 * it regardless of whether "select()" reports it as readable 2241 * or not. 2242 * 2243 * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()" 2244 * won't wake up and return "readable" if the timer expires 2245 * and non-blocking reads return EWOULDBLOCK if the hold 2246 * buffer is empty, even if the store buffer is non-empty. 2247 * 2248 * This means the workaround in question won't work. 2249 * 2250 * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd" 2251 * to -1, which means "sorry, you can't use 'select()' or 'poll()' 2252 * here". On all other BPF platforms, we set it to the FD for 2253 * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking 2254 * read will, if the hold buffer is empty and the store buffer 2255 * isn't empty, rotate the buffers and return what packets are 2256 * there (and in sufficiently recent versions of OpenBSD 2257 * "select()" and "poll()" should work correctly). 2258 * 2259 * XXX - what about AIX? 2260 */ 2261 p->selectable_fd = p->fd; /* assume select() works until we know otherwise */ 2262 if (have_osinfo) { 2263 /* 2264 * We can check what OS this is. 2265 */ 2266 if (strcmp(osinfo.sysname, "FreeBSD") == 0) { 2267 if (strncmp(osinfo.release, "4.3-", 4) == 0 || 2268 strncmp(osinfo.release, "4.4-", 4) == 0) 2269 p->selectable_fd = -1; 2270 } 2271 } 2272 2273 p->read_op = pcap_read_bpf; 2274 p->inject_op = pcap_inject_bpf; 2275 p->setfilter_op = pcap_setfilter_bpf; 2276 p->setdirection_op = pcap_setdirection_bpf; 2277 p->set_datalink_op = pcap_set_datalink_bpf; 2278 p->getnonblock_op = pcap_getnonblock_bpf; 2279 p->setnonblock_op = pcap_setnonblock_bpf; 2280 p->stats_op = pcap_stats_bpf; 2281 p->cleanup_op = pcap_cleanup_bpf; 2282 2283 return (status); 2284 bad: 2285 pcap_cleanup_bpf(p); 2286 return (status); 2287 } 2288 2289 int 2290 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 2291 { 2292 return (0); 2293 } 2294 2295 #ifdef HAVE_BSD_IEEE80211 2296 static int 2297 monitor_mode(pcap_t *p, int set) 2298 { 2299 struct pcap_bpf *pb = p->priv; 2300 int sock; 2301 struct ifmediareq req; 2302 int *media_list; 2303 int i; 2304 int can_do; 2305 struct ifreq ifr; 2306 2307 sock = socket(AF_INET, SOCK_DGRAM, 0); 2308 if (sock == -1) { 2309 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s", 2310 pcap_strerror(errno)); 2311 return (PCAP_ERROR); 2312 } 2313 2314 memset(&req, 0, sizeof req); 2315 strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name); 2316 2317 /* 2318 * Find out how many media types we have. 2319 */ 2320 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 2321 /* 2322 * Can't get the media types. 2323 */ 2324 switch (errno) { 2325 2326 case ENXIO: 2327 /* 2328 * There's no such device. 2329 */ 2330 close(sock); 2331 return (PCAP_ERROR_NO_SUCH_DEVICE); 2332 2333 case EINVAL: 2334 /* 2335 * Interface doesn't support SIOC{G,S}IFMEDIA. 2336 */ 2337 close(sock); 2338 return (PCAP_ERROR_RFMON_NOTSUP); 2339 2340 default: 2341 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2342 "SIOCGIFMEDIA 1: %s", pcap_strerror(errno)); 2343 close(sock); 2344 return (PCAP_ERROR); 2345 } 2346 } 2347 if (req.ifm_count == 0) { 2348 /* 2349 * No media types. 2350 */ 2351 close(sock); 2352 return (PCAP_ERROR_RFMON_NOTSUP); 2353 } 2354 2355 /* 2356 * Allocate a buffer to hold all the media types, and 2357 * get the media types. 2358 */ 2359 media_list = malloc(req.ifm_count * sizeof(int)); 2360 if (media_list == NULL) { 2361 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", 2362 pcap_strerror(errno)); 2363 close(sock); 2364 return (PCAP_ERROR); 2365 } 2366 req.ifm_ulist = media_list; 2367 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 2368 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s", 2369 pcap_strerror(errno)); 2370 free(media_list); 2371 close(sock); 2372 return (PCAP_ERROR); 2373 } 2374 2375 /* 2376 * Look for an 802.11 "automatic" media type. 2377 * We assume that all 802.11 adapters have that media type, 2378 * and that it will carry the monitor mode supported flag. 2379 */ 2380 can_do = 0; 2381 for (i = 0; i < req.ifm_count; i++) { 2382 if (IFM_TYPE(media_list[i]) == IFM_IEEE80211 2383 && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) { 2384 /* OK, does it do monitor mode? */ 2385 if (media_list[i] & IFM_IEEE80211_MONITOR) { 2386 can_do = 1; 2387 break; 2388 } 2389 } 2390 } 2391 free(media_list); 2392 if (!can_do) { 2393 /* 2394 * This adapter doesn't support monitor mode. 2395 */ 2396 close(sock); 2397 return (PCAP_ERROR_RFMON_NOTSUP); 2398 } 2399 2400 if (set) { 2401 /* 2402 * Don't just check whether we can enable monitor mode, 2403 * do so, if it's not already enabled. 2404 */ 2405 if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) { 2406 /* 2407 * Monitor mode isn't currently on, so turn it on, 2408 * and remember that we should turn it off when the 2409 * pcap_t is closed. 2410 */ 2411 2412 /* 2413 * If we haven't already done so, arrange to have 2414 * "pcap_close_all()" called when we exit. 2415 */ 2416 if (!pcap_do_addexit(p)) { 2417 /* 2418 * "atexit()" failed; don't put the interface 2419 * in monitor mode, just give up. 2420 */ 2421 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2422 "atexit failed"); 2423 close(sock); 2424 return (PCAP_ERROR); 2425 } 2426 memset(&ifr, 0, sizeof(ifr)); 2427 (void)strncpy(ifr.ifr_name, p->opt.source, 2428 sizeof(ifr.ifr_name)); 2429 ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR; 2430 if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) { 2431 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2432 "SIOCSIFMEDIA: %s", pcap_strerror(errno)); 2433 close(sock); 2434 return (PCAP_ERROR); 2435 } 2436 2437 pb->must_do_on_close |= MUST_CLEAR_RFMON; 2438 2439 /* 2440 * Add this to the list of pcaps to close when we exit. 2441 */ 2442 pcap_add_to_pcaps_to_close(p); 2443 } 2444 } 2445 return (0); 2446 } 2447 #endif /* HAVE_BSD_IEEE80211 */ 2448 2449 #if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) 2450 /* 2451 * Check whether we have any 802.11 link-layer types; return the best 2452 * of the 802.11 link-layer types if we find one, and return -1 2453 * otherwise. 2454 * 2455 * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the 2456 * best 802.11 link-layer type; any of the other 802.11-plus-radio 2457 * headers are second-best; 802.11 with no radio information is 2458 * the least good. 2459 */ 2460 static int 2461 find_802_11(struct bpf_dltlist *bdlp) 2462 { 2463 int new_dlt; 2464 u_int i; 2465 2466 /* 2467 * Scan the list of DLT_ values, looking for 802.11 values, 2468 * and, if we find any, choose the best of them. 2469 */ 2470 new_dlt = -1; 2471 for (i = 0; i < bdlp->bfl_len; i++) { 2472 switch (bdlp->bfl_list[i]) { 2473 2474 case DLT_IEEE802_11: 2475 /* 2476 * 802.11, but no radio. 2477 * 2478 * Offer this, and select it as the new mode 2479 * unless we've already found an 802.11 2480 * header with radio information. 2481 */ 2482 if (new_dlt == -1) 2483 new_dlt = bdlp->bfl_list[i]; 2484 break; 2485 2486 case DLT_PRISM_HEADER: 2487 case DLT_AIRONET_HEADER: 2488 case DLT_IEEE802_11_RADIO_AVS: 2489 /* 2490 * 802.11 with radio, but not radiotap. 2491 * 2492 * Offer this, and select it as the new mode 2493 * unless we've already found the radiotap DLT_. 2494 */ 2495 if (new_dlt != DLT_IEEE802_11_RADIO) 2496 new_dlt = bdlp->bfl_list[i]; 2497 break; 2498 2499 case DLT_IEEE802_11_RADIO: 2500 /* 2501 * 802.11 with radiotap. 2502 * 2503 * Offer this, and select it as the new mode. 2504 */ 2505 new_dlt = bdlp->bfl_list[i]; 2506 break; 2507 2508 default: 2509 /* 2510 * Not 802.11. 2511 */ 2512 break; 2513 } 2514 } 2515 2516 return (new_dlt); 2517 } 2518 #endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */ 2519 2520 #if defined(__APPLE__) && defined(BIOCGDLTLIST) 2521 /* 2522 * Remove DLT_EN10MB from the list of DLT_ values, as we're in monitor mode, 2523 * and DLT_EN10MB isn't supported in monitor mode. 2524 */ 2525 static void 2526 remove_en(pcap_t *p) 2527 { 2528 int i, j; 2529 2530 /* 2531 * Scan the list of DLT_ values and discard DLT_EN10MB. 2532 */ 2533 j = 0; 2534 for (i = 0; i < p->dlt_count; i++) { 2535 switch (p->dlt_list[i]) { 2536 2537 case DLT_EN10MB: 2538 /* 2539 * Don't offer this one. 2540 */ 2541 continue; 2542 2543 default: 2544 /* 2545 * Just copy this mode over. 2546 */ 2547 break; 2548 } 2549 2550 /* 2551 * Copy this DLT_ value to its new position. 2552 */ 2553 p->dlt_list[j] = p->dlt_list[i]; 2554 j++; 2555 } 2556 2557 /* 2558 * Set the DLT_ count to the number of entries we copied. 2559 */ 2560 p->dlt_count = j; 2561 } 2562 2563 /* 2564 * Remove 802.11 link-layer types from the list of DLT_ values, as 2565 * we're not in monitor mode, and those DLT_ values will switch us 2566 * to monitor mode. 2567 */ 2568 static void 2569 remove_802_11(pcap_t *p) 2570 { 2571 int i, j; 2572 2573 /* 2574 * Scan the list of DLT_ values and discard 802.11 values. 2575 */ 2576 j = 0; 2577 for (i = 0; i < p->dlt_count; i++) { 2578 switch (p->dlt_list[i]) { 2579 2580 case DLT_IEEE802_11: 2581 case DLT_PRISM_HEADER: 2582 case DLT_AIRONET_HEADER: 2583 case DLT_IEEE802_11_RADIO: 2584 case DLT_IEEE802_11_RADIO_AVS: 2585 /* 2586 * 802.11. Don't offer this one. 2587 */ 2588 continue; 2589 2590 default: 2591 /* 2592 * Just copy this mode over. 2593 */ 2594 break; 2595 } 2596 2597 /* 2598 * Copy this DLT_ value to its new position. 2599 */ 2600 p->dlt_list[j] = p->dlt_list[i]; 2601 j++; 2602 } 2603 2604 /* 2605 * Set the DLT_ count to the number of entries we copied. 2606 */ 2607 p->dlt_count = j; 2608 } 2609 #endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */ 2610 2611 static int 2612 pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) 2613 { 2614 struct pcap_bpf *pb = p->priv; 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 pb->filtering_in_kernel = 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 pb->filtering_in_kernel = 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