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 22 #ifdef HAVE_CONFIG_H 23 #include <config.h> 24 #endif 25 26 #include <sys/param.h> /* optionally get BSD define */ 27 #include <sys/socket.h> 28 #include <time.h> 29 /* 30 * <net/bpf.h> defines ioctls, but doesn't include <sys/ioccom.h>. 31 * 32 * We include <sys/ioctl.h> as it might be necessary to declare ioctl(); 33 * at least on *BSD and macOS, it also defines various SIOC ioctls - 34 * we could include <sys/sockio.h>, but if we're already including 35 * <sys/ioctl.h>, which includes <sys/sockio.h> on those platforms, 36 * there's not much point in doing so. 37 * 38 * If we have <sys/ioccom.h>, we include it as well, to handle systems 39 * such as Solaris which don't arrange to include <sys/ioccom.h> if you 40 * include <sys/ioctl.h> 41 */ 42 #include <sys/ioctl.h> 43 #ifdef HAVE_SYS_IOCCOM_H 44 #include <sys/ioccom.h> 45 #endif 46 #include <sys/utsname.h> 47 48 #if (defined(__FreeBSD__) || defined(__DragonFly__)) && defined(SIOCIFCREATE2) 49 /* 50 * Add support for capturing on FreeBSD usbusN interfaces. 51 */ 52 static const char usbus_prefix[] = "usbus"; 53 #define USBUS_PREFIX_LEN (sizeof(usbus_prefix) - 1) 54 #include <dirent.h> 55 #endif 56 57 #include <net/if.h> 58 59 #ifdef _AIX 60 61 /* 62 * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the 63 * native OS version, as we need "struct bpf_config" from it. 64 */ 65 #define PCAP_DONT_INCLUDE_PCAP_BPF_H 66 67 #include <sys/types.h> 68 69 /* 70 * Prevent bpf.h from redefining the DLT_ values to their 71 * IFT_ values, as we're going to return the standard libpcap 72 * values, not IBM's non-standard IFT_ values. 73 */ 74 #undef _AIX 75 #include <net/bpf.h> 76 #define _AIX 77 78 /* 79 * If both BIOCROTZBUF and BPF_BUFMODE_ZBUF are defined, we have 80 * zero-copy BPF. 81 */ 82 #if defined(BIOCROTZBUF) && defined(BPF_BUFMODE_ZBUF) 83 #define HAVE_ZEROCOPY_BPF 84 #include <sys/mman.h> 85 #include <machine/atomic.h> 86 #endif 87 88 #include <net/if_types.h> /* for IFT_ values */ 89 #include <sys/sysconfig.h> 90 #include <sys/device.h> 91 #include <sys/cfgodm.h> 92 #include <cf.h> 93 94 #ifdef __64BIT__ 95 #define domakedev makedev64 96 #define getmajor major64 97 #define bpf_hdr bpf_hdr32 98 #else /* __64BIT__ */ 99 #define domakedev makedev 100 #define getmajor major 101 #endif /* __64BIT__ */ 102 103 #define BPF_NAME "bpf" 104 #define BPF_MINORS 4 105 #define DRIVER_PATH "/usr/lib/drivers" 106 #define BPF_NODE "/dev/bpf" 107 static int bpfloadedflag = 0; 108 static int odmlockid = 0; 109 110 static int bpf_load(char *errbuf); 111 112 #else /* _AIX */ 113 114 #include <net/bpf.h> 115 116 #endif /* _AIX */ 117 118 #include <fcntl.h> 119 #include <errno.h> 120 #include <netdb.h> 121 #include <stdio.h> 122 #include <stdlib.h> 123 #include <string.h> 124 #include <unistd.h> 125 126 #ifdef SIOCGIFMEDIA 127 # include <net/if_media.h> 128 #endif 129 130 #include "pcap-int.h" 131 132 #ifdef HAVE_OS_PROTO_H 133 #include "os-proto.h" 134 #endif 135 136 /* 137 * Later versions of NetBSD stick padding in front of FDDI frames 138 * to align the IP header on a 4-byte boundary. 139 */ 140 #if defined(__NetBSD__) && __NetBSD_Version__ > 106000000 141 #define PCAP_FDDIPAD 3 142 #endif 143 144 /* 145 * Private data for capturing on BPF devices. 146 */ 147 struct pcap_bpf { 148 #ifdef HAVE_ZEROCOPY_BPF 149 /* 150 * Zero-copy read buffer -- for zero-copy BPF. 'buffer' above will 151 * alternative between these two actual mmap'd buffers as required. 152 * As there is a header on the front size of the mmap'd buffer, only 153 * some of the buffer is exposed to libpcap as a whole via bufsize; 154 * zbufsize is the true size. zbuffer tracks the current zbuf 155 * associated with buffer so that it can be used to decide which the 156 * next buffer to read will be. 157 */ 158 u_char *zbuf1, *zbuf2, *zbuffer; 159 u_int zbufsize; 160 u_int zerocopy; 161 u_int interrupted; 162 struct timespec firstsel; 163 /* 164 * If there's currently a buffer being actively processed, then it is 165 * referenced here; 'buffer' is also pointed at it, but offset by the 166 * size of the header. 167 */ 168 struct bpf_zbuf_header *bzh; 169 int nonblock; /* true if in nonblocking mode */ 170 #endif /* HAVE_ZEROCOPY_BPF */ 171 172 char *device; /* device name */ 173 int filtering_in_kernel; /* using kernel filter */ 174 int must_do_on_close; /* stuff we must do when we close */ 175 }; 176 177 /* 178 * Stuff to do when we close. 179 */ 180 #define MUST_CLEAR_RFMON 0x00000001 /* clear rfmon (monitor) mode */ 181 #define MUST_DESTROY_USBUS 0x00000002 /* destroy usbusN interface */ 182 183 #ifdef BIOCGDLTLIST 184 # if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__) 185 #define HAVE_BSD_IEEE80211 186 187 /* 188 * The ifm_ulist member of a struct ifmediareq is an int * on most systems, 189 * but it's a uint64_t on newer versions of OpenBSD. 190 * 191 * We check this by checking whether IFM_GMASK is defined and > 2^32-1. 192 */ 193 # if defined(IFM_GMASK) && IFM_GMASK > 0xFFFFFFFF 194 # define IFM_ULIST_TYPE uint64_t 195 # else 196 # define IFM_ULIST_TYPE int 197 # endif 198 # endif 199 200 # if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 201 static int find_802_11(struct bpf_dltlist *); 202 203 # ifdef HAVE_BSD_IEEE80211 204 static int monitor_mode(pcap_t *, int); 205 # endif 206 207 # if defined(__APPLE__) 208 static void remove_non_802_11(pcap_t *); 209 static void remove_802_11(pcap_t *); 210 # endif 211 212 # endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */ 213 214 #endif /* BIOCGDLTLIST */ 215 216 #if defined(sun) && defined(LIFNAMSIZ) && defined(lifr_zoneid) 217 #include <zone.h> 218 #endif 219 220 /* 221 * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably 222 * don't get DLT_DOCSIS defined. 223 */ 224 #ifndef DLT_DOCSIS 225 #define DLT_DOCSIS 143 226 #endif 227 228 /* 229 * In some versions of macOS, we might not even get any of the 230 * 802.11-plus-radio-header DLT_'s defined, even though some 231 * of them are used by various Airport drivers in those versions. 232 */ 233 #ifndef DLT_PRISM_HEADER 234 #define DLT_PRISM_HEADER 119 235 #endif 236 #ifndef DLT_AIRONET_HEADER 237 #define DLT_AIRONET_HEADER 120 238 #endif 239 #ifndef DLT_IEEE802_11_RADIO 240 #define DLT_IEEE802_11_RADIO 127 241 #endif 242 #ifndef DLT_IEEE802_11_RADIO_AVS 243 #define DLT_IEEE802_11_RADIO_AVS 163 244 #endif 245 246 static int pcap_can_set_rfmon_bpf(pcap_t *p); 247 static int pcap_activate_bpf(pcap_t *p); 248 static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp); 249 static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t); 250 static int pcap_set_datalink_bpf(pcap_t *p, int dlt); 251 252 /* 253 * For zerocopy bpf, the setnonblock/getnonblock routines need to modify 254 * pb->nonblock so we don't call select(2) if the pcap handle is in non- 255 * blocking mode. 256 */ 257 static int 258 pcap_getnonblock_bpf(pcap_t *p) 259 { 260 #ifdef HAVE_ZEROCOPY_BPF 261 struct pcap_bpf *pb = p->priv; 262 263 if (pb->zerocopy) 264 return (pb->nonblock); 265 #endif 266 return (pcap_getnonblock_fd(p)); 267 } 268 269 static int 270 pcap_setnonblock_bpf(pcap_t *p, int nonblock) 271 { 272 #ifdef HAVE_ZEROCOPY_BPF 273 struct pcap_bpf *pb = p->priv; 274 275 if (pb->zerocopy) { 276 pb->nonblock = nonblock; 277 return (0); 278 } 279 #endif 280 return (pcap_setnonblock_fd(p, nonblock)); 281 } 282 283 #ifdef HAVE_ZEROCOPY_BPF 284 /* 285 * Zero-copy BPF buffer routines to check for and acknowledge BPF data in 286 * shared memory buffers. 287 * 288 * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer, 289 * and set up p->buffer and cc to reflect one if available. Notice that if 290 * there was no prior buffer, we select zbuf1 as this will be the first 291 * buffer filled for a fresh BPF session. 292 */ 293 static int 294 pcap_next_zbuf_shm(pcap_t *p, int *cc) 295 { 296 struct pcap_bpf *pb = p->priv; 297 struct bpf_zbuf_header *bzh; 298 299 if (pb->zbuffer == pb->zbuf2 || pb->zbuffer == NULL) { 300 bzh = (struct bpf_zbuf_header *)pb->zbuf1; 301 if (bzh->bzh_user_gen != 302 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 303 pb->bzh = bzh; 304 pb->zbuffer = (u_char *)pb->zbuf1; 305 p->buffer = pb->zbuffer + sizeof(*bzh); 306 *cc = bzh->bzh_kernel_len; 307 return (1); 308 } 309 } else if (pb->zbuffer == pb->zbuf1) { 310 bzh = (struct bpf_zbuf_header *)pb->zbuf2; 311 if (bzh->bzh_user_gen != 312 atomic_load_acq_int(&bzh->bzh_kernel_gen)) { 313 pb->bzh = bzh; 314 pb->zbuffer = (u_char *)pb->zbuf2; 315 p->buffer = pb->zbuffer + sizeof(*bzh); 316 *cc = bzh->bzh_kernel_len; 317 return (1); 318 } 319 } 320 *cc = 0; 321 return (0); 322 } 323 324 /* 325 * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using 326 * select() for data or a timeout, and possibly force rotation of the buffer 327 * in the event we time out or are in immediate mode. Invoke the shared 328 * memory check before doing system calls in order to avoid doing avoidable 329 * work. 330 */ 331 static int 332 pcap_next_zbuf(pcap_t *p, int *cc) 333 { 334 struct pcap_bpf *pb = p->priv; 335 struct bpf_zbuf bz; 336 struct timeval tv; 337 struct timespec cur; 338 fd_set r_set; 339 int data, r; 340 int expire, tmout; 341 342 #define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000)) 343 /* 344 * Start out by seeing whether anything is waiting by checking the 345 * next shared memory buffer for data. 346 */ 347 data = pcap_next_zbuf_shm(p, cc); 348 if (data) 349 return (data); 350 /* 351 * If a previous sleep was interrupted due to signal delivery, make 352 * sure that the timeout gets adjusted accordingly. This requires 353 * that we analyze when the timeout should be been expired, and 354 * subtract the current time from that. If after this operation, 355 * our timeout is less then or equal to zero, handle it like a 356 * regular timeout. 357 */ 358 tmout = p->opt.timeout; 359 if (tmout) 360 (void) clock_gettime(CLOCK_MONOTONIC, &cur); 361 if (pb->interrupted && p->opt.timeout) { 362 expire = TSTOMILLI(&pb->firstsel) + p->opt.timeout; 363 tmout = expire - TSTOMILLI(&cur); 364 #undef TSTOMILLI 365 if (tmout <= 0) { 366 pb->interrupted = 0; 367 data = pcap_next_zbuf_shm(p, cc); 368 if (data) 369 return (data); 370 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 371 pcap_fmt_errmsg_for_errno(p->errbuf, 372 PCAP_ERRBUF_SIZE, errno, "BIOCROTZBUF"); 373 return (PCAP_ERROR); 374 } 375 return (pcap_next_zbuf_shm(p, cc)); 376 } 377 } 378 /* 379 * No data in the buffer, so must use select() to wait for data or 380 * the next timeout. Note that we only call select if the handle 381 * is in blocking mode. 382 */ 383 if (!pb->nonblock) { 384 FD_ZERO(&r_set); 385 FD_SET(p->fd, &r_set); 386 if (tmout != 0) { 387 tv.tv_sec = tmout / 1000; 388 tv.tv_usec = (tmout * 1000) % 1000000; 389 } 390 r = select(p->fd + 1, &r_set, NULL, NULL, 391 p->opt.timeout != 0 ? &tv : NULL); 392 if (r < 0 && errno == EINTR) { 393 if (!pb->interrupted && p->opt.timeout) { 394 pb->interrupted = 1; 395 pb->firstsel = cur; 396 } 397 return (0); 398 } else if (r < 0) { 399 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 400 errno, "select"); 401 return (PCAP_ERROR); 402 } 403 } 404 pb->interrupted = 0; 405 /* 406 * Check again for data, which may exist now that we've either been 407 * woken up as a result of data or timed out. Try the "there's data" 408 * case first since it doesn't require a system call. 409 */ 410 data = pcap_next_zbuf_shm(p, cc); 411 if (data) 412 return (data); 413 /* 414 * Try forcing a buffer rotation to dislodge timed out or immediate 415 * data. 416 */ 417 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { 418 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 419 errno, "BIOCROTZBUF"); 420 return (PCAP_ERROR); 421 } 422 return (pcap_next_zbuf_shm(p, cc)); 423 } 424 425 /* 426 * Notify kernel that we are done with the buffer. We don't reset zbuffer so 427 * that we know which buffer to use next time around. 428 */ 429 static int 430 pcap_ack_zbuf(pcap_t *p) 431 { 432 struct pcap_bpf *pb = p->priv; 433 434 atomic_store_rel_int(&pb->bzh->bzh_user_gen, 435 pb->bzh->bzh_kernel_gen); 436 pb->bzh = NULL; 437 p->buffer = NULL; 438 return (0); 439 } 440 #endif /* HAVE_ZEROCOPY_BPF */ 441 442 pcap_t * 443 pcap_create_interface(const char *device _U_, char *ebuf) 444 { 445 pcap_t *p; 446 447 p = PCAP_CREATE_COMMON(ebuf, struct pcap_bpf); 448 if (p == NULL) 449 return (NULL); 450 451 p->activate_op = pcap_activate_bpf; 452 p->can_set_rfmon_op = pcap_can_set_rfmon_bpf; 453 #ifdef BIOCSTSTAMP 454 /* 455 * We claim that we support microsecond and nanosecond time 456 * stamps. 457 */ 458 p->tstamp_precision_list = malloc(2 * sizeof(u_int)); 459 if (p->tstamp_precision_list == NULL) { 460 pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, errno, 461 "malloc"); 462 free(p); 463 return (NULL); 464 } 465 p->tstamp_precision_list[0] = PCAP_TSTAMP_PRECISION_MICRO; 466 p->tstamp_precision_list[1] = PCAP_TSTAMP_PRECISION_NANO; 467 p->tstamp_precision_count = 2; 468 #endif /* BIOCSTSTAMP */ 469 return (p); 470 } 471 472 /* 473 * On success, returns a file descriptor for a BPF device. 474 * On failure, returns a PCAP_ERROR_ value, and sets p->errbuf. 475 */ 476 static int 477 bpf_open(char *errbuf) 478 { 479 int fd = -1; 480 static const char cloning_device[] = "/dev/bpf"; 481 int n = 0; 482 char device[sizeof "/dev/bpf0000000000"]; 483 static int no_cloning_bpf = 0; 484 485 #ifdef _AIX 486 /* 487 * Load the bpf driver, if it isn't already loaded, 488 * and create the BPF device entries, if they don't 489 * already exist. 490 */ 491 if (bpf_load(errbuf) == PCAP_ERROR) 492 return (PCAP_ERROR); 493 #endif 494 495 /* 496 * First, unless we've already tried opening /dev/bpf and 497 * gotten ENOENT, try opening /dev/bpf. 498 * If it fails with ENOENT, remember that, so we don't try 499 * again, and try /dev/bpfN. 500 */ 501 if (!no_cloning_bpf && 502 (fd = open(cloning_device, O_RDWR)) == -1 && 503 ((errno != EACCES && errno != ENOENT) || 504 (fd = open(cloning_device, O_RDONLY)) == -1)) { 505 if (errno != ENOENT) { 506 if (errno == EACCES) 507 fd = PCAP_ERROR_PERM_DENIED; 508 else 509 fd = PCAP_ERROR; 510 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 511 errno, "(cannot open device) %s", cloning_device); 512 return (fd); 513 } 514 no_cloning_bpf = 1; 515 } 516 517 if (no_cloning_bpf) { 518 /* 519 * We don't have /dev/bpf. 520 * Go through all the /dev/bpfN minors and find one 521 * that isn't in use. 522 */ 523 do { 524 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); 525 /* 526 * Initially try a read/write open (to allow the inject 527 * method to work). If that fails due to permission 528 * issues, fall back to read-only. This allows a 529 * non-root user to be granted specific access to pcap 530 * capabilities via file permissions. 531 * 532 * XXX - we should have an API that has a flag that 533 * controls whether to open read-only or read-write, 534 * so that denial of permission to send (or inability 535 * to send, if sending packets isn't supported on 536 * the device in question) can be indicated at open 537 * time. 538 */ 539 fd = open(device, O_RDWR); 540 if (fd == -1 && errno == EACCES) 541 fd = open(device, O_RDONLY); 542 } while (fd < 0 && errno == EBUSY); 543 } 544 545 /* 546 * XXX better message for all minors used 547 */ 548 if (fd < 0) { 549 switch (errno) { 550 551 case ENOENT: 552 fd = PCAP_ERROR; 553 if (n == 1) { 554 /* 555 * /dev/bpf0 doesn't exist, which 556 * means we probably have no BPF 557 * devices. 558 */ 559 snprintf(errbuf, PCAP_ERRBUF_SIZE, 560 "(there are no BPF devices)"); 561 } else { 562 /* 563 * We got EBUSY on at least one 564 * BPF device, so we have BPF 565 * devices, but all the ones 566 * that exist are busy. 567 */ 568 snprintf(errbuf, PCAP_ERRBUF_SIZE, 569 "(all BPF devices are busy)"); 570 } 571 break; 572 573 case EACCES: 574 /* 575 * Got EACCES on the last device we tried, 576 * and EBUSY on all devices before that, 577 * if any. 578 */ 579 fd = PCAP_ERROR_PERM_DENIED; 580 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 581 errno, "(cannot open BPF device) %s", device); 582 break; 583 584 default: 585 /* 586 * Some other problem. 587 */ 588 fd = PCAP_ERROR; 589 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 590 errno, "(cannot open BPF device) %s", device); 591 break; 592 } 593 } 594 595 return (fd); 596 } 597 598 /* 599 * Bind a network adapter to a BPF device, given a descriptor for the 600 * BPF device and the name of the network adapter. 601 * 602 * Use BIOCSETLIF if available (meaning "on Solaris"), as it supports 603 * longer device names. 604 * 605 * If the name is longer than will fit, return PCAP_ERROR_NO_SUCH_DEVICE 606 * before trying to bind the interface, as there cannot be such a device. 607 * 608 * If the attempt succeeds, return BPF_BIND_SUCCEEDED. 609 * 610 * If the attempt fails: 611 * 612 * if it fails with ENXIO, return PCAP_ERROR_NO_SUCH_DEVICE, as 613 * the device doesn't exist; 614 * 615 * if it fails with ENETDOWN, return PCAP_ERROR_IFACE_NOT_UP, as 616 * the interface exists but isn't up and the OS doesn't allow 617 * binding to an interface that isn't up; 618 * 619 * if it fails with ENOBUFS, return BPF_BIND_BUFFER_TOO_BIG, and 620 * fill in an error message, as the buffer being requested is too 621 * large; 622 * 623 * otherwise, return PCAP_ERROR and fill in an error message. 624 */ 625 #define BPF_BIND_SUCCEEDED 0 626 #define BPF_BIND_BUFFER_TOO_BIG 1 627 628 static int 629 bpf_bind(int fd, const char *name, char *errbuf) 630 { 631 int status; 632 #ifdef LIFNAMSIZ 633 struct lifreq ifr; 634 635 if (strlen(name) >= sizeof(ifr.lifr_name)) { 636 /* The name is too long, so it can't possibly exist. */ 637 return (PCAP_ERROR_NO_SUCH_DEVICE); 638 } 639 (void)pcap_strlcpy(ifr.lifr_name, name, sizeof(ifr.lifr_name)); 640 status = ioctl(fd, BIOCSETLIF, (caddr_t)&ifr); 641 #else 642 struct ifreq ifr; 643 644 if (strlen(name) >= sizeof(ifr.ifr_name)) { 645 /* The name is too long, so it can't possibly exist. */ 646 return (PCAP_ERROR_NO_SUCH_DEVICE); 647 } 648 (void)pcap_strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name)); 649 status = ioctl(fd, BIOCSETIF, (caddr_t)&ifr); 650 #endif 651 652 if (status < 0) { 653 switch (errno) { 654 655 case ENXIO: 656 /* 657 * There's no such device. 658 */ 659 return (PCAP_ERROR_NO_SUCH_DEVICE); 660 661 case ENETDOWN: 662 /* 663 * Return a "network down" indication, so that 664 * the application can report that rather than 665 * saying we had a mysterious failure and 666 * suggest that they report a problem to the 667 * libpcap developers. 668 */ 669 return (PCAP_ERROR_IFACE_NOT_UP); 670 671 case ENOBUFS: 672 /* 673 * The buffer size is too big. 674 * Return a special indication so that, if we're 675 * trying to crank the buffer size down, we know 676 * we have to continue; add an error message that 677 * tells the user what needs to be fixed. 678 */ 679 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 680 errno, "The requested buffer size for %s is too large", 681 name); 682 return (BPF_BIND_BUFFER_TOO_BIG); 683 684 default: 685 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 686 errno, "Binding interface %s to BPF device failed", 687 name); 688 return (PCAP_ERROR); 689 } 690 } 691 return (BPF_BIND_SUCCEEDED); 692 } 693 694 /* 695 * Open and bind to a device; used if we're not actually going to use 696 * the device, but are just testing whether it can be opened, or opening 697 * it to get information about it. 698 * 699 * Returns an error code on failure (always negative), and an FD for 700 * the now-bound BPF device on success (always non-negative). 701 */ 702 static int 703 bpf_open_and_bind(const char *name, char *errbuf) 704 { 705 int fd; 706 int status; 707 708 /* 709 * First, open a BPF device. 710 */ 711 fd = bpf_open(errbuf); 712 if (fd < 0) 713 return (fd); /* fd is the appropriate error code */ 714 715 /* 716 * Now bind to the device. 717 */ 718 status = bpf_bind(fd, name, errbuf); 719 if (status != BPF_BIND_SUCCEEDED) { 720 close(fd); 721 if (status == BPF_BIND_BUFFER_TOO_BIG) { 722 /* 723 * We didn't specify a buffer size, so 724 * this *really* shouldn't fail because 725 * there's no buffer space. Fail. 726 */ 727 return (PCAP_ERROR); 728 } 729 return (status); 730 } 731 732 /* 733 * Success. 734 */ 735 return (fd); 736 } 737 738 #ifdef __APPLE__ 739 static int 740 device_exists(int fd, const char *name, char *errbuf) 741 { 742 int status; 743 struct ifreq ifr; 744 745 if (strlen(name) >= sizeof(ifr.ifr_name)) { 746 /* The name is too long, so it can't possibly exist. */ 747 return (PCAP_ERROR_NO_SUCH_DEVICE); 748 } 749 (void)pcap_strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name)); 750 status = ioctl(fd, SIOCGIFFLAGS, (caddr_t)&ifr); 751 752 if (status < 0) { 753 if (errno == ENXIO || errno == EINVAL) { 754 /* 755 * macOS and *BSD return one of those two 756 * errors if the device doesn't exist. 757 * Don't fill in an error, as this is 758 * an "expected" condition. 759 */ 760 return (PCAP_ERROR_NO_SUCH_DEVICE); 761 } 762 763 /* 764 * Some other error - provide a message for it, as 765 * it's "unexpected". 766 */ 767 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, errno, 768 "Can't get interface flags on %s", name); 769 return (PCAP_ERROR); 770 } 771 772 /* 773 * The device exists. 774 */ 775 return (0); 776 } 777 #endif 778 779 #ifdef BIOCGDLTLIST 780 static int 781 get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf) 782 { 783 memset(bdlp, 0, sizeof(*bdlp)); 784 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) { 785 u_int i; 786 int is_ethernet; 787 788 bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1)); 789 if (bdlp->bfl_list == NULL) { 790 pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, 791 errno, "malloc"); 792 return (PCAP_ERROR); 793 } 794 795 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) { 796 pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, 797 errno, "BIOCGDLTLIST"); 798 free(bdlp->bfl_list); 799 return (PCAP_ERROR); 800 } 801 802 /* 803 * OK, for real Ethernet devices, add DLT_DOCSIS to the 804 * list, so that an application can let you choose it, 805 * in case you're capturing DOCSIS traffic that a Cisco 806 * Cable Modem Termination System is putting out onto 807 * an Ethernet (it doesn't put an Ethernet header onto 808 * the wire, it puts raw DOCSIS frames out on the wire 809 * inside the low-level Ethernet framing). 810 * 811 * A "real Ethernet device" is defined here as a device 812 * that has a link-layer type of DLT_EN10MB and that has 813 * no alternate link-layer types; that's done to exclude 814 * 802.11 interfaces (which might or might not be the 815 * right thing to do, but I suspect it is - Ethernet <-> 816 * 802.11 bridges would probably badly mishandle frames 817 * that don't have Ethernet headers). 818 * 819 * On Solaris with BPF, Ethernet devices also offer 820 * DLT_IPNET, so we, if DLT_IPNET is defined, we don't 821 * treat it as an indication that the device isn't an 822 * Ethernet. 823 */ 824 if (v == DLT_EN10MB) { 825 is_ethernet = 1; 826 for (i = 0; i < bdlp->bfl_len; i++) { 827 if (bdlp->bfl_list[i] != DLT_EN10MB 828 #ifdef DLT_IPNET 829 && bdlp->bfl_list[i] != DLT_IPNET 830 #endif 831 ) { 832 is_ethernet = 0; 833 break; 834 } 835 } 836 if (is_ethernet) { 837 /* 838 * We reserved one more slot at the end of 839 * the list. 840 */ 841 bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS; 842 bdlp->bfl_len++; 843 } 844 } 845 } else { 846 /* 847 * EINVAL just means "we don't support this ioctl on 848 * this device"; don't treat it as an error. 849 */ 850 if (errno != EINVAL) { 851 pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, 852 errno, "BIOCGDLTLIST"); 853 return (PCAP_ERROR); 854 } 855 } 856 return (0); 857 } 858 #endif 859 860 #if defined(__APPLE__) 861 static int 862 pcap_can_set_rfmon_bpf(pcap_t *p) 863 { 864 struct utsname osinfo; 865 int fd; 866 #ifdef BIOCGDLTLIST 867 struct bpf_dltlist bdl; 868 int err; 869 #endif 870 871 /* 872 * The joys of monitor mode on Mac OS X/OS X/macOS. 873 * 874 * Prior to 10.4, it's not supported at all. 875 * 876 * In 10.4, if adapter enN supports monitor mode, there's a 877 * wltN adapter corresponding to it; you open it, instead of 878 * enN, to get monitor mode. You get whatever link-layer 879 * headers it supplies. 880 * 881 * In 10.5, and, we assume, later releases, if adapter enN 882 * supports monitor mode, it offers, among its selectable 883 * DLT_ values, values that let you get the 802.11 header; 884 * selecting one of those values puts the adapter into monitor 885 * mode (i.e., you can't get 802.11 headers except in monitor 886 * mode, and you can't get Ethernet headers in monitor mode). 887 */ 888 if (uname(&osinfo) == -1) { 889 /* 890 * Can't get the OS version; just say "no". 891 */ 892 return (0); 893 } 894 /* 895 * We assume osinfo.sysname is "Darwin", because 896 * __APPLE__ is defined. We just check the version. 897 */ 898 if (osinfo.release[0] < '8' && osinfo.release[1] == '.') { 899 /* 900 * 10.3 (Darwin 7.x) or earlier. 901 * Monitor mode not supported. 902 */ 903 return (0); 904 } 905 if (osinfo.release[0] == '8' && osinfo.release[1] == '.') { 906 char *wlt_name; 907 int status; 908 909 /* 910 * 10.4 (Darwin 8.x). s/en/wlt/, and check 911 * whether the device exists. 912 */ 913 if (strncmp(p->opt.device, "en", 2) != 0) { 914 /* 915 * Not an enN device; no monitor mode. 916 */ 917 return (0); 918 } 919 fd = socket(AF_INET, SOCK_DGRAM, 0); 920 if (fd == -1) { 921 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 922 errno, "socket"); 923 return (PCAP_ERROR); 924 } 925 if (pcap_asprintf(&wlt_name, "wlt%s", p->opt.device + 2) == -1) { 926 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 927 errno, "malloc"); 928 close(fd); 929 return (PCAP_ERROR); 930 } 931 status = device_exists(fd, wlt_name, p->errbuf); 932 free(wlt_name); 933 close(fd); 934 if (status != 0) { 935 if (status == PCAP_ERROR_NO_SUCH_DEVICE) 936 return (0); 937 938 /* 939 * Error. 940 */ 941 return (status); 942 } 943 return (1); 944 } 945 946 #ifdef BIOCGDLTLIST 947 /* 948 * Everything else is 10.5 or later; for those, 949 * we just open the enN device, and check whether 950 * we have any 802.11 devices. 951 * 952 * First, open a BPF device. 953 */ 954 fd = bpf_open(p->errbuf); 955 if (fd < 0) 956 return (fd); /* fd is the appropriate error code */ 957 958 /* 959 * Now bind to the device. 960 */ 961 err = bpf_bind(fd, p->opt.device, p->errbuf); 962 if (err != BPF_BIND_SUCCEEDED) { 963 close(fd); 964 if (err == BPF_BIND_BUFFER_TOO_BIG) { 965 /* 966 * We didn't specify a buffer size, so 967 * this *really* shouldn't fail because 968 * there's no buffer space. Fail. 969 */ 970 return (PCAP_ERROR); 971 } 972 return (err); 973 } 974 975 /* 976 * We know the default link type -- now determine all the DLTs 977 * this interface supports. If this fails with EINVAL, it's 978 * not fatal; we just don't get to use the feature later. 979 * (We don't care about DLT_DOCSIS, so we pass DLT_NULL 980 * as the default DLT for this adapter.) 981 */ 982 if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) { 983 close(fd); 984 return (PCAP_ERROR); 985 } 986 if (find_802_11(&bdl) != -1) { 987 /* 988 * We have an 802.11 DLT, so we can set monitor mode. 989 */ 990 free(bdl.bfl_list); 991 close(fd); 992 return (1); 993 } 994 free(bdl.bfl_list); 995 close(fd); 996 #endif /* BIOCGDLTLIST */ 997 return (0); 998 } 999 #elif defined(HAVE_BSD_IEEE80211) 1000 static int 1001 pcap_can_set_rfmon_bpf(pcap_t *p) 1002 { 1003 int ret; 1004 1005 ret = monitor_mode(p, 0); 1006 if (ret == PCAP_ERROR_RFMON_NOTSUP) 1007 return (0); /* not an error, just a "can't do" */ 1008 if (ret == 0) 1009 return (1); /* success */ 1010 return (ret); 1011 } 1012 #else 1013 static int 1014 pcap_can_set_rfmon_bpf(pcap_t *p _U_) 1015 { 1016 return (0); 1017 } 1018 #endif 1019 1020 static int 1021 pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) 1022 { 1023 struct bpf_stat s; 1024 1025 /* 1026 * "ps_recv" counts packets handed to the filter, not packets 1027 * that passed the filter. This includes packets later dropped 1028 * because we ran out of buffer space. 1029 * 1030 * "ps_drop" counts packets dropped inside the BPF device 1031 * because we ran out of buffer space. It doesn't count 1032 * packets dropped by the interface driver. It counts 1033 * only packets that passed the filter. 1034 * 1035 * Both statistics include packets not yet read from the kernel 1036 * by libpcap, and thus not yet seen by the application. 1037 */ 1038 if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) { 1039 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1040 errno, "BIOCGSTATS"); 1041 return (PCAP_ERROR); 1042 } 1043 1044 ps->ps_recv = s.bs_recv; 1045 ps->ps_drop = s.bs_drop; 1046 ps->ps_ifdrop = 0; 1047 return (0); 1048 } 1049 1050 static int 1051 pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 1052 { 1053 struct pcap_bpf *pb = p->priv; 1054 int cc; 1055 int n = 0; 1056 register u_char *bp, *ep; 1057 u_char *datap; 1058 #ifdef PCAP_FDDIPAD 1059 register u_int pad; 1060 #endif 1061 #ifdef HAVE_ZEROCOPY_BPF 1062 int i; 1063 #endif 1064 1065 again: 1066 /* 1067 * Has "pcap_breakloop()" been called? 1068 */ 1069 if (p->break_loop) { 1070 /* 1071 * Yes - clear the flag that indicates that it 1072 * has, and return PCAP_ERROR_BREAK to indicate 1073 * that we were told to break out of the loop. 1074 */ 1075 p->break_loop = 0; 1076 return (PCAP_ERROR_BREAK); 1077 } 1078 cc = p->cc; 1079 if (p->cc == 0) { 1080 /* 1081 * When reading without zero-copy from a file descriptor, we 1082 * use a single buffer and return a length of data in the 1083 * buffer. With zero-copy, we update the p->buffer pointer 1084 * to point at whatever underlying buffer contains the next 1085 * data and update cc to reflect the data found in the 1086 * buffer. 1087 */ 1088 #ifdef HAVE_ZEROCOPY_BPF 1089 if (pb->zerocopy) { 1090 if (p->buffer != NULL) 1091 pcap_ack_zbuf(p); 1092 i = pcap_next_zbuf(p, &cc); 1093 if (i == 0) 1094 goto again; 1095 if (i < 0) 1096 return (PCAP_ERROR); 1097 } else 1098 #endif 1099 { 1100 cc = (int)read(p->fd, p->buffer, p->bufsize); 1101 } 1102 if (cc < 0) { 1103 /* Don't choke when we get ptraced */ 1104 switch (errno) { 1105 1106 case EINTR: 1107 goto again; 1108 1109 #ifdef _AIX 1110 case EFAULT: 1111 /* 1112 * Sigh. More AIX wonderfulness. 1113 * 1114 * For some unknown reason the uiomove() 1115 * operation in the bpf kernel extension 1116 * used to copy the buffer into user 1117 * space sometimes returns EFAULT. I have 1118 * no idea why this is the case given that 1119 * a kernel debugger shows the user buffer 1120 * is correct. This problem appears to 1121 * be mostly mitigated by the memset of 1122 * the buffer before it is first used. 1123 * Very strange.... Shaun Clowes 1124 * 1125 * In any case this means that we shouldn't 1126 * treat EFAULT as a fatal error; as we 1127 * don't have an API for returning 1128 * a "some packets were dropped since 1129 * the last packet you saw" indication, 1130 * we just ignore EFAULT and keep reading. 1131 */ 1132 goto again; 1133 #endif 1134 1135 case EWOULDBLOCK: 1136 return (0); 1137 1138 case ENXIO: /* FreeBSD, DragonFly BSD, and Darwin */ 1139 case EIO: /* OpenBSD */ 1140 /* NetBSD appears not to return an error in this case */ 1141 /* 1142 * The device on which we're capturing 1143 * went away. 1144 * 1145 * XXX - we should really return 1146 * an appropriate error for that, 1147 * but pcap_dispatch() etc. aren't 1148 * documented as having error returns 1149 * other than PCAP_ERROR or PCAP_ERROR_BREAK. 1150 */ 1151 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1152 "The interface disappeared"); 1153 return (PCAP_ERROR); 1154 1155 #if defined(sun) && !defined(BSD) && !defined(__svr4__) && !defined(__SVR4) 1156 /* 1157 * Due to a SunOS bug, after 2^31 bytes, the kernel 1158 * file offset overflows and read fails with EINVAL. 1159 * The lseek() to 0 will fix things. 1160 */ 1161 case EINVAL: 1162 if (lseek(p->fd, 0L, SEEK_CUR) + 1163 p->bufsize < 0) { 1164 (void)lseek(p->fd, 0L, SEEK_SET); 1165 goto again; 1166 } 1167 /* fall through */ 1168 #endif 1169 } 1170 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1171 errno, "read"); 1172 return (PCAP_ERROR); 1173 } 1174 bp = (u_char *)p->buffer; 1175 } else 1176 bp = p->bp; 1177 1178 /* 1179 * Loop through each packet. 1180 */ 1181 #ifdef BIOCSTSTAMP 1182 #define bhp ((struct bpf_xhdr *)bp) 1183 #else 1184 #define bhp ((struct bpf_hdr *)bp) 1185 #endif 1186 ep = bp + cc; 1187 #ifdef PCAP_FDDIPAD 1188 pad = p->fddipad; 1189 #endif 1190 while (bp < ep) { 1191 register u_int caplen, hdrlen; 1192 1193 /* 1194 * Has "pcap_breakloop()" been called? 1195 * If so, return immediately - if we haven't read any 1196 * packets, clear the flag and return PCAP_ERROR_BREAK 1197 * to indicate that we were told to break out of the loop, 1198 * otherwise leave the flag set, so that the *next* call 1199 * will break out of the loop without having read any 1200 * packets, and return the number of packets we've 1201 * processed so far. 1202 */ 1203 if (p->break_loop) { 1204 p->bp = bp; 1205 p->cc = (int)(ep - bp); 1206 /* 1207 * ep is set based on the return value of read(), 1208 * but read() from a BPF device doesn't necessarily 1209 * return a value that's a multiple of the alignment 1210 * value for BPF_WORDALIGN(). However, whenever we 1211 * increment bp, we round up the increment value by 1212 * a value rounded up by BPF_WORDALIGN(), so we 1213 * could increment bp past ep after processing the 1214 * last packet in the buffer. 1215 * 1216 * We treat ep < bp as an indication that this 1217 * happened, and just set p->cc to 0. 1218 */ 1219 if (p->cc < 0) 1220 p->cc = 0; 1221 if (n == 0) { 1222 p->break_loop = 0; 1223 return (PCAP_ERROR_BREAK); 1224 } else 1225 return (n); 1226 } 1227 1228 caplen = bhp->bh_caplen; 1229 hdrlen = bhp->bh_hdrlen; 1230 datap = bp + hdrlen; 1231 /* 1232 * Short-circuit evaluation: if using BPF filter 1233 * in kernel, no need to do it now - we already know 1234 * the packet passed the filter. 1235 * 1236 #ifdef PCAP_FDDIPAD 1237 * Note: the filter code was generated assuming 1238 * that p->fddipad was the amount of padding 1239 * before the header, as that's what's required 1240 * in the kernel, so we run the filter before 1241 * skipping that padding. 1242 #endif 1243 */ 1244 if (pb->filtering_in_kernel || 1245 pcap_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) { 1246 struct pcap_pkthdr pkthdr; 1247 #ifdef BIOCSTSTAMP 1248 struct bintime bt; 1249 1250 bt.sec = bhp->bh_tstamp.bt_sec; 1251 bt.frac = bhp->bh_tstamp.bt_frac; 1252 if (p->opt.tstamp_precision == PCAP_TSTAMP_PRECISION_NANO) { 1253 struct timespec ts; 1254 1255 bintime2timespec(&bt, &ts); 1256 pkthdr.ts.tv_sec = ts.tv_sec; 1257 pkthdr.ts.tv_usec = ts.tv_nsec; 1258 } else { 1259 struct timeval tv; 1260 1261 bintime2timeval(&bt, &tv); 1262 pkthdr.ts.tv_sec = tv.tv_sec; 1263 pkthdr.ts.tv_usec = tv.tv_usec; 1264 } 1265 #else 1266 pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec; 1267 #ifdef _AIX 1268 /* 1269 * AIX's BPF returns seconds/nanoseconds time 1270 * stamps, not seconds/microseconds time stamps. 1271 */ 1272 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000; 1273 #else 1274 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec; 1275 #endif 1276 #endif /* BIOCSTSTAMP */ 1277 #ifdef PCAP_FDDIPAD 1278 if (caplen > pad) 1279 pkthdr.caplen = caplen - pad; 1280 else 1281 pkthdr.caplen = 0; 1282 if (bhp->bh_datalen > pad) 1283 pkthdr.len = bhp->bh_datalen - pad; 1284 else 1285 pkthdr.len = 0; 1286 datap += pad; 1287 #else 1288 pkthdr.caplen = caplen; 1289 pkthdr.len = bhp->bh_datalen; 1290 #endif 1291 (*callback)(user, &pkthdr, datap); 1292 bp += BPF_WORDALIGN(caplen + hdrlen); 1293 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) { 1294 p->bp = bp; 1295 p->cc = (int)(ep - bp); 1296 /* 1297 * See comment above about p->cc < 0. 1298 */ 1299 if (p->cc < 0) 1300 p->cc = 0; 1301 return (n); 1302 } 1303 } else { 1304 /* 1305 * Skip this packet. 1306 */ 1307 bp += BPF_WORDALIGN(caplen + hdrlen); 1308 } 1309 } 1310 #undef bhp 1311 p->cc = 0; 1312 return (n); 1313 } 1314 1315 static int 1316 pcap_inject_bpf(pcap_t *p, const void *buf, int size) 1317 { 1318 int ret; 1319 1320 ret = (int)write(p->fd, buf, size); 1321 #ifdef __APPLE__ 1322 if (ret == -1 && errno == EAFNOSUPPORT) { 1323 /* 1324 * In some versions of macOS, there's a bug wherein setting 1325 * the BIOCSHDRCMPLT flag causes writes to fail; see, for 1326 * example: 1327 * 1328 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch 1329 * 1330 * So, if, on macOS, we get EAFNOSUPPORT from the write, we 1331 * assume it's due to that bug, and turn off that flag 1332 * and try again. If we succeed, it either means that 1333 * somebody applied the fix from that URL, or other patches 1334 * for that bug from 1335 * 1336 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/ 1337 * 1338 * and are running a Darwin kernel with those fixes, or 1339 * that Apple fixed the problem in some macOS release. 1340 */ 1341 u_int spoof_eth_src = 0; 1342 1343 if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 1344 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1345 errno, "send: can't turn off BIOCSHDRCMPLT"); 1346 return (PCAP_ERROR); 1347 } 1348 1349 /* 1350 * Now try the write again. 1351 */ 1352 ret = (int)write(p->fd, buf, size); 1353 } 1354 #endif /* __APPLE__ */ 1355 if (ret == -1) { 1356 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1357 errno, "send"); 1358 return (PCAP_ERROR); 1359 } 1360 return (ret); 1361 } 1362 1363 #ifdef _AIX 1364 static int 1365 bpf_odminit(char *errbuf) 1366 { 1367 char *errstr; 1368 1369 if (odm_initialize() == -1) { 1370 if (odm_err_msg(odmerrno, &errstr) == -1) 1371 errstr = "Unknown error"; 1372 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1373 "bpf_load: odm_initialize failed: %s", 1374 errstr); 1375 return (PCAP_ERROR); 1376 } 1377 1378 if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) { 1379 if (odm_err_msg(odmerrno, &errstr) == -1) 1380 errstr = "Unknown error"; 1381 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1382 "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s", 1383 errstr); 1384 (void)odm_terminate(); 1385 return (PCAP_ERROR); 1386 } 1387 1388 return (0); 1389 } 1390 1391 static int 1392 bpf_odmcleanup(char *errbuf) 1393 { 1394 char *errstr; 1395 1396 if (odm_unlock(odmlockid) == -1) { 1397 if (errbuf != NULL) { 1398 if (odm_err_msg(odmerrno, &errstr) == -1) 1399 errstr = "Unknown error"; 1400 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1401 "bpf_load: odm_unlock failed: %s", 1402 errstr); 1403 } 1404 return (PCAP_ERROR); 1405 } 1406 1407 if (odm_terminate() == -1) { 1408 if (errbuf != NULL) { 1409 if (odm_err_msg(odmerrno, &errstr) == -1) 1410 errstr = "Unknown error"; 1411 snprintf(errbuf, PCAP_ERRBUF_SIZE, 1412 "bpf_load: odm_terminate failed: %s", 1413 errstr); 1414 } 1415 return (PCAP_ERROR); 1416 } 1417 1418 return (0); 1419 } 1420 1421 static int 1422 bpf_load(char *errbuf) 1423 { 1424 long major; 1425 int *minors; 1426 int numminors, i, rc; 1427 char buf[1024]; 1428 struct stat sbuf; 1429 struct bpf_config cfg_bpf; 1430 struct cfg_load cfg_ld; 1431 struct cfg_kmod cfg_km; 1432 1433 /* 1434 * This is very very close to what happens in the real implementation 1435 * but I've fixed some (unlikely) bug situations. 1436 */ 1437 if (bpfloadedflag) 1438 return (0); 1439 1440 if (bpf_odminit(errbuf) == PCAP_ERROR) 1441 return (PCAP_ERROR); 1442 1443 major = genmajor(BPF_NAME); 1444 if (major == -1) { 1445 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 1446 errno, "bpf_load: genmajor failed"); 1447 (void)bpf_odmcleanup(NULL); 1448 return (PCAP_ERROR); 1449 } 1450 1451 minors = getminor(major, &numminors, BPF_NAME); 1452 if (!minors) { 1453 minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1); 1454 if (!minors) { 1455 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 1456 errno, "bpf_load: genminor failed"); 1457 (void)bpf_odmcleanup(NULL); 1458 return (PCAP_ERROR); 1459 } 1460 } 1461 1462 if (bpf_odmcleanup(errbuf) == PCAP_ERROR) 1463 return (PCAP_ERROR); 1464 1465 rc = stat(BPF_NODE "0", &sbuf); 1466 if (rc == -1 && errno != ENOENT) { 1467 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 1468 errno, "bpf_load: can't stat %s", BPF_NODE "0"); 1469 return (PCAP_ERROR); 1470 } 1471 1472 if (rc == -1 || getmajor(sbuf.st_rdev) != major) { 1473 for (i = 0; i < BPF_MINORS; i++) { 1474 snprintf(buf, sizeof(buf), "%s%d", BPF_NODE, i); 1475 unlink(buf); 1476 if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) { 1477 pcap_fmt_errmsg_for_errno(errbuf, 1478 PCAP_ERRBUF_SIZE, errno, 1479 "bpf_load: can't mknod %s", buf); 1480 return (PCAP_ERROR); 1481 } 1482 } 1483 } 1484 1485 /* Check if the driver is loaded */ 1486 memset(&cfg_ld, 0x0, sizeof(cfg_ld)); 1487 snprintf(buf, sizeof(buf), "%s/%s", DRIVER_PATH, BPF_NAME); 1488 cfg_ld.path = buf; 1489 if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) || 1490 (cfg_ld.kmid == 0)) { 1491 /* Driver isn't loaded, load it now */ 1492 if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) { 1493 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 1494 errno, "bpf_load: could not load driver"); 1495 return (PCAP_ERROR); 1496 } 1497 } 1498 1499 /* Configure the driver */ 1500 cfg_km.cmd = CFG_INIT; 1501 cfg_km.kmid = cfg_ld.kmid; 1502 cfg_km.mdilen = sizeof(cfg_bpf); 1503 cfg_km.mdiptr = (void *)&cfg_bpf; 1504 for (i = 0; i < BPF_MINORS; i++) { 1505 cfg_bpf.devno = domakedev(major, i); 1506 if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) { 1507 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 1508 errno, "bpf_load: could not configure driver"); 1509 return (PCAP_ERROR); 1510 } 1511 } 1512 1513 bpfloadedflag = 1; 1514 1515 return (0); 1516 } 1517 #endif 1518 1519 /* 1520 * Undo any operations done when opening the device when necessary. 1521 */ 1522 static void 1523 pcap_cleanup_bpf(pcap_t *p) 1524 { 1525 struct pcap_bpf *pb = p->priv; 1526 #ifdef HAVE_BSD_IEEE80211 1527 int sock; 1528 struct ifmediareq req; 1529 struct ifreq ifr; 1530 #endif 1531 1532 if (pb->must_do_on_close != 0) { 1533 /* 1534 * There's something we have to do when closing this 1535 * pcap_t. 1536 */ 1537 #ifdef HAVE_BSD_IEEE80211 1538 if (pb->must_do_on_close & MUST_CLEAR_RFMON) { 1539 /* 1540 * We put the interface into rfmon mode; 1541 * take it out of rfmon mode. 1542 * 1543 * XXX - if somebody else wants it in rfmon 1544 * mode, this code cannot know that, so it'll take 1545 * it out of rfmon mode. 1546 */ 1547 sock = socket(AF_INET, SOCK_DGRAM, 0); 1548 if (sock == -1) { 1549 fprintf(stderr, 1550 "Can't restore interface flags (socket() failed: %s).\n" 1551 "Please adjust manually.\n", 1552 strerror(errno)); 1553 } else { 1554 memset(&req, 0, sizeof(req)); 1555 pcap_strlcpy(req.ifm_name, pb->device, 1556 sizeof(req.ifm_name)); 1557 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 1558 fprintf(stderr, 1559 "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n" 1560 "Please adjust manually.\n", 1561 strerror(errno)); 1562 } else { 1563 if (req.ifm_current & IFM_IEEE80211_MONITOR) { 1564 /* 1565 * Rfmon mode is currently on; 1566 * turn it off. 1567 */ 1568 memset(&ifr, 0, sizeof(ifr)); 1569 (void)pcap_strlcpy(ifr.ifr_name, 1570 pb->device, 1571 sizeof(ifr.ifr_name)); 1572 ifr.ifr_media = 1573 req.ifm_current & ~IFM_IEEE80211_MONITOR; 1574 if (ioctl(sock, SIOCSIFMEDIA, 1575 &ifr) == -1) { 1576 fprintf(stderr, 1577 "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n" 1578 "Please adjust manually.\n", 1579 strerror(errno)); 1580 } 1581 } 1582 } 1583 close(sock); 1584 } 1585 } 1586 #endif /* HAVE_BSD_IEEE80211 */ 1587 1588 #if (defined(__FreeBSD__) || defined(__DragonFly__)) && defined(SIOCIFCREATE2) 1589 /* 1590 * Attempt to destroy the usbusN interface that we created. 1591 */ 1592 if (pb->must_do_on_close & MUST_DESTROY_USBUS) { 1593 if (if_nametoindex(pb->device) > 0) { 1594 int s; 1595 1596 s = socket(AF_LOCAL, SOCK_DGRAM, 0); 1597 if (s >= 0) { 1598 pcap_strlcpy(ifr.ifr_name, pb->device, 1599 sizeof(ifr.ifr_name)); 1600 ioctl(s, SIOCIFDESTROY, &ifr); 1601 close(s); 1602 } 1603 } 1604 } 1605 #endif /* (defined(__FreeBSD__) || defined(__DragonFly__)) && defined(SIOCIFCREATE2) */ 1606 /* 1607 * Take this pcap out of the list of pcaps for which we 1608 * have to take the interface out of some mode. 1609 */ 1610 pcap_remove_from_pcaps_to_close(p); 1611 pb->must_do_on_close = 0; 1612 } 1613 1614 #ifdef HAVE_ZEROCOPY_BPF 1615 if (pb->zerocopy) { 1616 /* 1617 * Delete the mappings. Note that p->buffer gets 1618 * initialized to one of the mmapped regions in 1619 * this case, so do not try and free it directly; 1620 * null it out so that pcap_cleanup_live_common() 1621 * doesn't try to free it. 1622 */ 1623 if (pb->zbuf1 != MAP_FAILED && pb->zbuf1 != NULL) 1624 (void) munmap(pb->zbuf1, pb->zbufsize); 1625 if (pb->zbuf2 != MAP_FAILED && pb->zbuf2 != NULL) 1626 (void) munmap(pb->zbuf2, pb->zbufsize); 1627 p->buffer = NULL; 1628 } 1629 #endif 1630 if (pb->device != NULL) { 1631 free(pb->device); 1632 pb->device = NULL; 1633 } 1634 pcap_cleanup_live_common(p); 1635 } 1636 1637 #ifdef __APPLE__ 1638 static int 1639 check_setif_failure(pcap_t *p, int error) 1640 { 1641 int fd; 1642 int err; 1643 1644 if (error == PCAP_ERROR_NO_SUCH_DEVICE) { 1645 /* 1646 * No such device exists. 1647 */ 1648 if (p->opt.rfmon && strncmp(p->opt.device, "wlt", 3) == 0) { 1649 /* 1650 * Monitor mode was requested, and we're trying 1651 * to open a "wltN" device. Assume that this 1652 * is 10.4 and that we were asked to open an 1653 * "enN" device; if that device exists, return 1654 * "monitor mode not supported on the device". 1655 */ 1656 fd = socket(AF_INET, SOCK_DGRAM, 0); 1657 if (fd != -1) { 1658 char *en_name; 1659 1660 if (pcap_asprintf(&en_name, "en%s", 1661 p->opt.device + 3) == -1) { 1662 /* 1663 * We can't find out whether there's 1664 * an underlying "enN" device, so 1665 * just report "no such device". 1666 */ 1667 pcap_fmt_errmsg_for_errno(p->errbuf, 1668 PCAP_ERRBUF_SIZE, errno, 1669 "malloc"); 1670 close(fd); 1671 return (PCAP_ERROR_NO_SUCH_DEVICE); 1672 } 1673 err = device_exists(fd, en_name, p->errbuf); 1674 free(en_name); 1675 if (err != 0) { 1676 if (err == PCAP_ERROR_NO_SUCH_DEVICE) { 1677 /* 1678 * The underlying "enN" device 1679 * exists, but there's no 1680 * corresponding "wltN" device; 1681 * that means that the "enN" 1682 * device doesn't support 1683 * monitor mode, probably 1684 * because it's an Ethernet 1685 * device rather than a 1686 * wireless device. 1687 */ 1688 err = PCAP_ERROR_RFMON_NOTSUP; 1689 } 1690 } 1691 close(fd); 1692 } else { 1693 /* 1694 * We can't find out whether there's 1695 * an underlying "enN" device, so 1696 * just report "no such device". 1697 */ 1698 err = PCAP_ERROR_NO_SUCH_DEVICE; 1699 pcap_fmt_errmsg_for_errno(p->errbuf, 1700 errno, PCAP_ERRBUF_SIZE, 1701 "socket() failed"); 1702 } 1703 return (err); 1704 } 1705 1706 /* 1707 * No such device. 1708 */ 1709 return (PCAP_ERROR_NO_SUCH_DEVICE); 1710 } 1711 1712 /* 1713 * Just return the error status; it's what we want, and, if it's 1714 * PCAP_ERROR, the error string has been filled in. 1715 */ 1716 return (error); 1717 } 1718 #else 1719 static int 1720 check_setif_failure(pcap_t *p _U_, int error) 1721 { 1722 /* 1723 * Just return the error status; it's what we want, and, if it's 1724 * PCAP_ERROR, the error string has been filled in. 1725 */ 1726 return (error); 1727 } 1728 #endif 1729 1730 /* 1731 * Default capture buffer size. 1732 * 32K isn't very much for modern machines with fast networks; we 1733 * pick .5M, as that's the maximum on at least some systems with BPF. 1734 * 1735 * However, on AIX 3.5, the larger buffer sized caused unrecoverable 1736 * read failures under stress, so we leave it as 32K; yet another 1737 * place where AIX's BPF is broken. 1738 */ 1739 #ifdef _AIX 1740 #define DEFAULT_BUFSIZE 32768 1741 #else 1742 #define DEFAULT_BUFSIZE 524288 1743 #endif 1744 1745 static int 1746 pcap_activate_bpf(pcap_t *p) 1747 { 1748 struct pcap_bpf *pb = p->priv; 1749 int status = 0; 1750 #ifdef HAVE_BSD_IEEE80211 1751 int retv; 1752 #endif 1753 int fd; 1754 #if defined(LIFNAMSIZ) && defined(ZONENAME_MAX) && defined(lifr_zoneid) 1755 struct lifreq ifr; 1756 char *zonesep; 1757 #endif 1758 struct bpf_version bv; 1759 #ifdef __APPLE__ 1760 int sockfd; 1761 char *wltdev = NULL; 1762 #endif 1763 #ifdef BIOCGDLTLIST 1764 struct bpf_dltlist bdl; 1765 #if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) 1766 int new_dlt; 1767 #endif 1768 #endif /* BIOCGDLTLIST */ 1769 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 1770 u_int spoof_eth_src = 1; 1771 #endif 1772 u_int v; 1773 struct bpf_insn total_insn; 1774 struct bpf_program total_prog; 1775 struct utsname osinfo; 1776 int have_osinfo = 0; 1777 #ifdef HAVE_ZEROCOPY_BPF 1778 struct bpf_zbuf bz; 1779 u_int bufmode, zbufmax; 1780 #endif 1781 1782 fd = bpf_open(p->errbuf); 1783 if (fd < 0) { 1784 status = fd; 1785 goto bad; 1786 } 1787 1788 p->fd = fd; 1789 1790 if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) { 1791 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1792 errno, "BIOCVERSION"); 1793 status = PCAP_ERROR; 1794 goto bad; 1795 } 1796 if (bv.bv_major != BPF_MAJOR_VERSION || 1797 bv.bv_minor < BPF_MINOR_VERSION) { 1798 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1799 "kernel bpf filter out of date"); 1800 status = PCAP_ERROR; 1801 goto bad; 1802 } 1803 1804 /* 1805 * Turn a negative snapshot value (invalid), a snapshot value of 1806 * 0 (unspecified), or a value bigger than the normal maximum 1807 * value, into the maximum allowed value. 1808 * 1809 * If some application really *needs* a bigger snapshot 1810 * length, we should just increase MAXIMUM_SNAPLEN. 1811 */ 1812 if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN) 1813 p->snapshot = MAXIMUM_SNAPLEN; 1814 1815 #if defined(LIFNAMSIZ) && defined(ZONENAME_MAX) && defined(lifr_zoneid) 1816 /* 1817 * Retrieve the zoneid of the zone we are currently executing in. 1818 */ 1819 if ((ifr.lifr_zoneid = getzoneid()) == -1) { 1820 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1821 errno, "getzoneid()"); 1822 status = PCAP_ERROR; 1823 goto bad; 1824 } 1825 /* 1826 * Check if the given source datalink name has a '/' separated 1827 * zonename prefix string. The zonename prefixed source datalink can 1828 * be used by pcap consumers in the Solaris global zone to capture 1829 * traffic on datalinks in non-global zones. Non-global zones 1830 * do not have access to datalinks outside of their own namespace. 1831 */ 1832 if ((zonesep = strchr(p->opt.device, '/')) != NULL) { 1833 char path_zname[ZONENAME_MAX]; 1834 int znamelen; 1835 char *lnamep; 1836 1837 if (ifr.lifr_zoneid != GLOBAL_ZONEID) { 1838 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1839 "zonename/linkname only valid in global zone."); 1840 status = PCAP_ERROR; 1841 goto bad; 1842 } 1843 znamelen = zonesep - p->opt.device; 1844 (void) pcap_strlcpy(path_zname, p->opt.device, znamelen + 1); 1845 ifr.lifr_zoneid = getzoneidbyname(path_zname); 1846 if (ifr.lifr_zoneid == -1) { 1847 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1848 errno, "getzoneidbyname(%s)", path_zname); 1849 status = PCAP_ERROR; 1850 goto bad; 1851 } 1852 lnamep = strdup(zonesep + 1); 1853 if (lnamep == NULL) { 1854 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1855 errno, "strdup"); 1856 status = PCAP_ERROR; 1857 goto bad; 1858 } 1859 free(p->opt.device); 1860 p->opt.device = lnamep; 1861 } 1862 #endif 1863 1864 pb->device = strdup(p->opt.device); 1865 if (pb->device == NULL) { 1866 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 1867 errno, "strdup"); 1868 status = PCAP_ERROR; 1869 goto bad; 1870 } 1871 1872 /* 1873 * Attempt to find out the version of the OS on which we're running. 1874 */ 1875 if (uname(&osinfo) == 0) 1876 have_osinfo = 1; 1877 1878 #ifdef __APPLE__ 1879 /* 1880 * See comment in pcap_can_set_rfmon_bpf() for an explanation 1881 * of why we check the version number. 1882 */ 1883 if (p->opt.rfmon) { 1884 if (have_osinfo) { 1885 /* 1886 * We assume osinfo.sysname is "Darwin", because 1887 * __APPLE__ is defined. We just check the version. 1888 */ 1889 if (osinfo.release[0] < '8' && 1890 osinfo.release[1] == '.') { 1891 /* 1892 * 10.3 (Darwin 7.x) or earlier. 1893 */ 1894 status = PCAP_ERROR_RFMON_NOTSUP; 1895 goto bad; 1896 } 1897 if (osinfo.release[0] == '8' && 1898 osinfo.release[1] == '.') { 1899 /* 1900 * 10.4 (Darwin 8.x). s/en/wlt/ 1901 */ 1902 if (strncmp(p->opt.device, "en", 2) != 0) { 1903 /* 1904 * Not an enN device; check 1905 * whether the device even exists. 1906 */ 1907 sockfd = socket(AF_INET, SOCK_DGRAM, 0); 1908 if (sockfd != -1) { 1909 status = device_exists(sockfd, 1910 p->opt.device, p->errbuf); 1911 if (status == 0) { 1912 /* 1913 * The device exists, 1914 * but it's not an 1915 * enN device; that 1916 * means it doesn't 1917 * support monitor 1918 * mode. 1919 */ 1920 status = PCAP_ERROR_RFMON_NOTSUP; 1921 } 1922 close(sockfd); 1923 } else { 1924 /* 1925 * We can't find out whether 1926 * the device exists, so just 1927 * report "no such device". 1928 */ 1929 status = PCAP_ERROR_NO_SUCH_DEVICE; 1930 pcap_fmt_errmsg_for_errno(p->errbuf, 1931 PCAP_ERRBUF_SIZE, errno, 1932 "socket() failed"); 1933 } 1934 goto bad; 1935 } 1936 wltdev = malloc(strlen(p->opt.device) + 2); 1937 if (wltdev == NULL) { 1938 pcap_fmt_errmsg_for_errno(p->errbuf, 1939 PCAP_ERRBUF_SIZE, errno, 1940 "malloc"); 1941 status = PCAP_ERROR; 1942 goto bad; 1943 } 1944 strcpy(wltdev, "wlt"); 1945 strcat(wltdev, p->opt.device + 2); 1946 free(p->opt.device); 1947 p->opt.device = wltdev; 1948 } 1949 /* 1950 * Everything else is 10.5 or later; for those, 1951 * we just open the enN device, and set the DLT. 1952 */ 1953 } 1954 } 1955 #endif /* __APPLE__ */ 1956 1957 /* 1958 * If this is FreeBSD, and the device name begins with "usbus", 1959 * try to create the interface if it's not available. 1960 */ 1961 #if (defined(__FreeBSD__) || defined(__DragonFly__)) && defined(SIOCIFCREATE2) 1962 if (strncmp(p->opt.device, usbus_prefix, USBUS_PREFIX_LEN) == 0) { 1963 /* 1964 * Do we already have an interface with that name? 1965 */ 1966 if (if_nametoindex(p->opt.device) == 0) { 1967 /* 1968 * No. We need to create it, and, if we 1969 * succeed, remember that we should destroy 1970 * it when the pcap_t is closed. 1971 */ 1972 int s; 1973 struct ifreq ifr; 1974 1975 /* 1976 * Open a socket to use for ioctls to 1977 * create the interface. 1978 */ 1979 s = socket(AF_LOCAL, SOCK_DGRAM, 0); 1980 if (s < 0) { 1981 pcap_fmt_errmsg_for_errno(p->errbuf, 1982 PCAP_ERRBUF_SIZE, errno, 1983 "Can't open socket"); 1984 status = PCAP_ERROR; 1985 goto bad; 1986 } 1987 1988 /* 1989 * If we haven't already done so, arrange to have 1990 * "pcap_close_all()" called when we exit. 1991 */ 1992 if (!pcap_do_addexit(p)) { 1993 /* 1994 * "atexit()" failed; don't create the 1995 * interface, just give up. 1996 */ 1997 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 1998 "atexit failed"); 1999 close(s); 2000 status = PCAP_ERROR; 2001 goto bad; 2002 } 2003 2004 /* 2005 * Create the interface. 2006 */ 2007 pcap_strlcpy(ifr.ifr_name, p->opt.device, sizeof(ifr.ifr_name)); 2008 if (ioctl(s, SIOCIFCREATE2, &ifr) < 0) { 2009 if (errno == EINVAL) { 2010 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2011 "Invalid USB bus interface %s", 2012 p->opt.device); 2013 } else { 2014 pcap_fmt_errmsg_for_errno(p->errbuf, 2015 PCAP_ERRBUF_SIZE, errno, 2016 "Can't create interface for %s", 2017 p->opt.device); 2018 } 2019 close(s); 2020 status = PCAP_ERROR; 2021 goto bad; 2022 } 2023 2024 /* 2025 * Make sure we clean this up when we close. 2026 */ 2027 pb->must_do_on_close |= MUST_DESTROY_USBUS; 2028 2029 /* 2030 * Add this to the list of pcaps to close when we exit. 2031 */ 2032 pcap_add_to_pcaps_to_close(p); 2033 } 2034 } 2035 #endif /* (defined(__FreeBSD__) || defined(__DragonFly__)) && defined(SIOCIFCREATE2) */ 2036 2037 #ifdef HAVE_ZEROCOPY_BPF 2038 /* 2039 * If the BPF extension to set buffer mode is present, try setting 2040 * the mode to zero-copy. If that fails, use regular buffering. If 2041 * it succeeds but other setup fails, return an error to the user. 2042 */ 2043 bufmode = BPF_BUFMODE_ZBUF; 2044 if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) { 2045 /* 2046 * We have zerocopy BPF; use it. 2047 */ 2048 pb->zerocopy = 1; 2049 2050 /* 2051 * How to pick a buffer size: first, query the maximum buffer 2052 * size supported by zero-copy. This also lets us quickly 2053 * determine whether the kernel generally supports zero-copy. 2054 * Then, if a buffer size was specified, use that, otherwise 2055 * query the default buffer size, which reflects kernel 2056 * policy for a desired default. Round to the nearest page 2057 * size. 2058 */ 2059 if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) { 2060 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2061 errno, "BIOCGETZMAX"); 2062 status = PCAP_ERROR; 2063 goto bad; 2064 } 2065 2066 if (p->opt.buffer_size != 0) { 2067 /* 2068 * A buffer size was explicitly specified; use it. 2069 */ 2070 v = p->opt.buffer_size; 2071 } else { 2072 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 2073 v < DEFAULT_BUFSIZE) 2074 v = DEFAULT_BUFSIZE; 2075 } 2076 #ifndef roundup 2077 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 2078 #endif 2079 pb->zbufsize = roundup(v, getpagesize()); 2080 if (pb->zbufsize > zbufmax) 2081 pb->zbufsize = zbufmax; 2082 pb->zbuf1 = mmap(NULL, pb->zbufsize, PROT_READ | PROT_WRITE, 2083 MAP_ANON, -1, 0); 2084 pb->zbuf2 = mmap(NULL, pb->zbufsize, PROT_READ | PROT_WRITE, 2085 MAP_ANON, -1, 0); 2086 if (pb->zbuf1 == MAP_FAILED || pb->zbuf2 == MAP_FAILED) { 2087 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2088 errno, "mmap"); 2089 status = PCAP_ERROR; 2090 goto bad; 2091 } 2092 memset(&bz, 0, sizeof(bz)); /* bzero() deprecated, replaced with memset() */ 2093 bz.bz_bufa = pb->zbuf1; 2094 bz.bz_bufb = pb->zbuf2; 2095 bz.bz_buflen = pb->zbufsize; 2096 if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) { 2097 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2098 errno, "BIOCSETZBUF"); 2099 status = PCAP_ERROR; 2100 goto bad; 2101 } 2102 status = bpf_bind(fd, p->opt.device, ifnamsiz, p->errbuf); 2103 if (status != BPF_BIND_SUCCEEDED) { 2104 if (status == BPF_BIND_BUFFER_TOO_BIG) { 2105 /* 2106 * The requested buffer size 2107 * is too big. Fail. 2108 * 2109 * XXX - should we do the "keep cutting 2110 * the buffer size in half" loop here if 2111 * we're using the default buffer size? 2112 */ 2113 status = PCAP_ERROR; 2114 } 2115 goto bad; 2116 } 2117 v = pb->zbufsize - sizeof(struct bpf_zbuf_header); 2118 } else 2119 #endif 2120 { 2121 /* 2122 * We don't have zerocopy BPF. 2123 * Set the buffer size. 2124 */ 2125 if (p->opt.buffer_size != 0) { 2126 /* 2127 * A buffer size was explicitly specified; use it. 2128 */ 2129 if (ioctl(fd, BIOCSBLEN, 2130 (caddr_t)&p->opt.buffer_size) < 0) { 2131 pcap_fmt_errmsg_for_errno(p->errbuf, 2132 PCAP_ERRBUF_SIZE, errno, 2133 "BIOCSBLEN: %s", p->opt.device); 2134 status = PCAP_ERROR; 2135 goto bad; 2136 } 2137 2138 /* 2139 * Now bind to the device. 2140 */ 2141 status = bpf_bind(fd, p->opt.device, p->errbuf); 2142 if (status != BPF_BIND_SUCCEEDED) { 2143 if (status == BPF_BIND_BUFFER_TOO_BIG) { 2144 /* 2145 * The requested buffer size 2146 * is too big. Fail. 2147 */ 2148 status = PCAP_ERROR; 2149 goto bad; 2150 } 2151 2152 /* 2153 * Special checks on macOS to deal with 2154 * the way monitor mode was done on 2155 * 10.4 Tiger. 2156 */ 2157 status = check_setif_failure(p, status); 2158 goto bad; 2159 } 2160 } else { 2161 /* 2162 * No buffer size was explicitly specified. 2163 * 2164 * Try finding a good size for the buffer; 2165 * DEFAULT_BUFSIZE may be too big, so keep 2166 * cutting it in half until we find a size 2167 * that works, or run out of sizes to try. 2168 * If the default is larger, don't make it smaller. 2169 */ 2170 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || 2171 v < DEFAULT_BUFSIZE) 2172 v = DEFAULT_BUFSIZE; 2173 for ( ; v != 0; v >>= 1) { 2174 /* 2175 * Ignore the return value - this is because the 2176 * call fails on BPF systems that don't have 2177 * kernel malloc. And if the call fails, it's 2178 * no big deal, we just continue to use the 2179 * standard buffer size. 2180 */ 2181 (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v); 2182 2183 status = bpf_bind(fd, p->opt.device, p->errbuf); 2184 if (status == BPF_BIND_SUCCEEDED) 2185 break; /* that size worked; we're done */ 2186 2187 /* 2188 * If the attempt failed because the 2189 * buffer was too big, cut the buffer 2190 * size in half and try again. 2191 * 2192 * Otherwise, fail. 2193 */ 2194 if (errno != BPF_BIND_BUFFER_TOO_BIG) { 2195 /* 2196 * Special checks on macOS to deal 2197 * with the way monitor mode was 2198 * done on 10.4 Tiger. 2199 */ 2200 status = check_setif_failure(p, status); 2201 goto bad; 2202 } 2203 } 2204 2205 if (v == 0) { 2206 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 2207 "BIOCSBLEN: %s: No buffer size worked", 2208 p->opt.device); 2209 status = PCAP_ERROR; 2210 goto bad; 2211 } 2212 } 2213 } 2214 2215 /* Get the data link layer type. */ 2216 if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) { 2217 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2218 errno, "BIOCGDLT"); 2219 status = PCAP_ERROR; 2220 goto bad; 2221 } 2222 2223 #ifdef _AIX 2224 /* 2225 * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT. 2226 */ 2227 switch (v) { 2228 2229 case IFT_ETHER: 2230 case IFT_ISO88023: 2231 v = DLT_EN10MB; 2232 break; 2233 2234 case IFT_FDDI: 2235 v = DLT_FDDI; 2236 break; 2237 2238 case IFT_ISO88025: 2239 v = DLT_IEEE802; 2240 break; 2241 2242 case IFT_LOOP: 2243 v = DLT_NULL; 2244 break; 2245 2246 default: 2247 /* 2248 * We don't know what to map this to yet. 2249 */ 2250 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", 2251 v); 2252 status = PCAP_ERROR; 2253 goto bad; 2254 } 2255 #endif 2256 #if _BSDI_VERSION - 0 >= 199510 2257 /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */ 2258 switch (v) { 2259 2260 case DLT_SLIP: 2261 v = DLT_SLIP_BSDOS; 2262 break; 2263 2264 case DLT_PPP: 2265 v = DLT_PPP_BSDOS; 2266 break; 2267 2268 case 11: /*DLT_FR*/ 2269 v = DLT_FRELAY; 2270 break; 2271 2272 case 12: /*DLT_C_HDLC*/ 2273 v = DLT_CHDLC; 2274 break; 2275 } 2276 #endif 2277 2278 #ifdef BIOCGDLTLIST 2279 /* 2280 * We know the default link type -- now determine all the DLTs 2281 * this interface supports. If this fails with EINVAL, it's 2282 * not fatal; we just don't get to use the feature later. 2283 */ 2284 if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) { 2285 status = PCAP_ERROR; 2286 goto bad; 2287 } 2288 p->dlt_count = bdl.bfl_len; 2289 p->dlt_list = bdl.bfl_list; 2290 2291 #ifdef __APPLE__ 2292 /* 2293 * Monitor mode fun, continued. 2294 * 2295 * For 10.5 and, we're assuming, later releases, as noted above, 2296 * 802.1 adapters that support monitor mode offer both DLT_EN10MB, 2297 * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information 2298 * DLT_ value. Choosing one of the 802.11 DLT_ values will turn 2299 * monitor mode on. 2300 * 2301 * Therefore, if the user asked for monitor mode, we filter out 2302 * the DLT_EN10MB value, as you can't get that in monitor mode, 2303 * and, if the user didn't ask for monitor mode, we filter out 2304 * the 802.11 DLT_ values, because selecting those will turn 2305 * monitor mode on. Then, for monitor mode, if an 802.11-plus- 2306 * radio DLT_ value is offered, we try to select that, otherwise 2307 * we try to select DLT_IEEE802_11. 2308 */ 2309 if (have_osinfo) { 2310 if (PCAP_ISDIGIT((unsigned)osinfo.release[0]) && 2311 (osinfo.release[0] == '9' || 2312 PCAP_ISDIGIT((unsigned)osinfo.release[1]))) { 2313 /* 2314 * 10.5 (Darwin 9.x), or later. 2315 */ 2316 new_dlt = find_802_11(&bdl); 2317 if (new_dlt != -1) { 2318 /* 2319 * We have at least one 802.11 DLT_ value, 2320 * so this is an 802.11 interface. 2321 * new_dlt is the best of the 802.11 2322 * DLT_ values in the list. 2323 */ 2324 if (p->opt.rfmon) { 2325 /* 2326 * Our caller wants monitor mode. 2327 * Purge DLT_EN10MB from the list 2328 * of link-layer types, as selecting 2329 * it will keep monitor mode off. 2330 */ 2331 remove_non_802_11(p); 2332 2333 /* 2334 * If the new mode we want isn't 2335 * the default mode, attempt to 2336 * select the new mode. 2337 */ 2338 if ((u_int)new_dlt != v) { 2339 if (ioctl(p->fd, BIOCSDLT, 2340 &new_dlt) != -1) { 2341 /* 2342 * We succeeded; 2343 * make this the 2344 * new DLT_ value. 2345 */ 2346 v = new_dlt; 2347 } 2348 } 2349 } else { 2350 /* 2351 * Our caller doesn't want 2352 * monitor mode. Unless this 2353 * is being done by pcap_open_live(), 2354 * purge the 802.11 link-layer types 2355 * from the list, as selecting 2356 * one of them will turn monitor 2357 * mode on. 2358 */ 2359 if (!p->oldstyle) 2360 remove_802_11(p); 2361 } 2362 } else { 2363 if (p->opt.rfmon) { 2364 /* 2365 * The caller requested monitor 2366 * mode, but we have no 802.11 2367 * link-layer types, so they 2368 * can't have it. 2369 */ 2370 status = PCAP_ERROR_RFMON_NOTSUP; 2371 goto bad; 2372 } 2373 } 2374 } 2375 } 2376 #elif defined(HAVE_BSD_IEEE80211) 2377 /* 2378 * *BSD with the new 802.11 ioctls. 2379 * Do we want monitor mode? 2380 */ 2381 if (p->opt.rfmon) { 2382 /* 2383 * Try to put the interface into monitor mode. 2384 */ 2385 retv = monitor_mode(p, 1); 2386 if (retv != 0) { 2387 /* 2388 * We failed. 2389 */ 2390 status = retv; 2391 goto bad; 2392 } 2393 2394 /* 2395 * We're in monitor mode. 2396 * Try to find the best 802.11 DLT_ value and, if we 2397 * succeed, try to switch to that mode if we're not 2398 * already in that mode. 2399 */ 2400 new_dlt = find_802_11(&bdl); 2401 if (new_dlt != -1) { 2402 /* 2403 * We have at least one 802.11 DLT_ value. 2404 * new_dlt is the best of the 802.11 2405 * DLT_ values in the list. 2406 * 2407 * If the new mode we want isn't the default mode, 2408 * attempt to select the new mode. 2409 */ 2410 if ((u_int)new_dlt != v) { 2411 if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) { 2412 /* 2413 * We succeeded; make this the 2414 * new DLT_ value. 2415 */ 2416 v = new_dlt; 2417 } 2418 } 2419 } 2420 } 2421 #endif /* various platforms */ 2422 #endif /* BIOCGDLTLIST */ 2423 2424 /* 2425 * If this is an Ethernet device, and we don't have a DLT_ list, 2426 * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give 2427 * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to 2428 * do, but there's not much we can do about that without finding 2429 * some other way of determining whether it's an Ethernet or 802.11 2430 * device.) 2431 */ 2432 if (v == DLT_EN10MB && p->dlt_count == 0) { 2433 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 2434 /* 2435 * If that fails, just leave the list empty. 2436 */ 2437 if (p->dlt_list != NULL) { 2438 p->dlt_list[0] = DLT_EN10MB; 2439 p->dlt_list[1] = DLT_DOCSIS; 2440 p->dlt_count = 2; 2441 } 2442 } 2443 #ifdef PCAP_FDDIPAD 2444 if (v == DLT_FDDI) 2445 p->fddipad = PCAP_FDDIPAD; 2446 else 2447 #endif 2448 p->fddipad = 0; 2449 p->linktype = v; 2450 2451 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) 2452 /* 2453 * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so 2454 * the link-layer source address isn't forcibly overwritten. 2455 * (Should we ignore errors? Should we do this only if 2456 * we're open for writing?) 2457 * 2458 * XXX - I seem to remember some packet-sending bug in some 2459 * BSDs - check CVS log for "bpf.c"? 2460 */ 2461 if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { 2462 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2463 errno, "BIOCSHDRCMPLT"); 2464 status = PCAP_ERROR; 2465 goto bad; 2466 } 2467 #endif 2468 /* set timeout */ 2469 #ifdef HAVE_ZEROCOPY_BPF 2470 /* 2471 * In zero-copy mode, we just use the timeout in select(). 2472 * XXX - what if we're in non-blocking mode and the *application* 2473 * is using select() or poll() or kqueues or....? 2474 */ 2475 if (p->opt.timeout && !pb->zerocopy) { 2476 #else 2477 if (p->opt.timeout) { 2478 #endif 2479 /* 2480 * XXX - is this seconds/nanoseconds in AIX? 2481 * (Treating it as such doesn't fix the timeout 2482 * problem described below.) 2483 * 2484 * XXX - Mac OS X 10.6 mishandles BIOCSRTIMEOUT in 2485 * 64-bit userland - it takes, as an argument, a 2486 * "struct BPF_TIMEVAL", which has 32-bit tv_sec 2487 * and tv_usec, rather than a "struct timeval". 2488 * 2489 * If this platform defines "struct BPF_TIMEVAL", 2490 * we check whether the structure size in BIOCSRTIMEOUT 2491 * is that of a "struct timeval" and, if not, we use 2492 * a "struct BPF_TIMEVAL" rather than a "struct timeval". 2493 * (That way, if the bug is fixed in a future release, 2494 * we will still do the right thing.) 2495 */ 2496 struct timeval to; 2497 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2498 struct BPF_TIMEVAL bpf_to; 2499 2500 if (IOCPARM_LEN(BIOCSRTIMEOUT) != sizeof(struct timeval)) { 2501 bpf_to.tv_sec = p->opt.timeout / 1000; 2502 bpf_to.tv_usec = (p->opt.timeout * 1000) % 1000000; 2503 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&bpf_to) < 0) { 2504 pcap_fmt_errmsg_for_errno(p->errbuf, 2505 errno, PCAP_ERRBUF_SIZE, "BIOCSRTIMEOUT"); 2506 status = PCAP_ERROR; 2507 goto bad; 2508 } 2509 } else { 2510 #endif 2511 to.tv_sec = p->opt.timeout / 1000; 2512 to.tv_usec = (p->opt.timeout * 1000) % 1000000; 2513 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) { 2514 pcap_fmt_errmsg_for_errno(p->errbuf, 2515 errno, PCAP_ERRBUF_SIZE, "BIOCSRTIMEOUT"); 2516 status = PCAP_ERROR; 2517 goto bad; 2518 } 2519 #ifdef HAVE_STRUCT_BPF_TIMEVAL 2520 } 2521 #endif 2522 } 2523 2524 #ifdef BIOCIMMEDIATE 2525 /* 2526 * Darren Reed notes that 2527 * 2528 * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the 2529 * timeout appears to be ignored and it waits until the buffer 2530 * is filled before returning. The result of not having it 2531 * set is almost worse than useless if your BPF filter 2532 * is reducing things to only a few packets (i.e. one every 2533 * second or so). 2534 * 2535 * so we always turn BIOCIMMEDIATE mode on if this is AIX. 2536 * 2537 * For other platforms, we don't turn immediate mode on by default, 2538 * as that would mean we get woken up for every packet, which 2539 * probably isn't what you want for a packet sniffer. 2540 * 2541 * We set immediate mode if the caller requested it by calling 2542 * pcap_set_immediate() before calling pcap_activate(). 2543 */ 2544 #ifndef _AIX 2545 if (p->opt.immediate) { 2546 #endif /* _AIX */ 2547 v = 1; 2548 if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) { 2549 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2550 errno, "BIOCIMMEDIATE"); 2551 status = PCAP_ERROR; 2552 goto bad; 2553 } 2554 #ifndef _AIX 2555 } 2556 #endif /* _AIX */ 2557 #else /* BIOCIMMEDIATE */ 2558 if (p->opt.immediate) { 2559 /* 2560 * We don't support immediate mode. Fail. 2561 */ 2562 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Immediate mode not supported"); 2563 status = PCAP_ERROR; 2564 goto bad; 2565 } 2566 #endif /* BIOCIMMEDIATE */ 2567 2568 if (p->opt.promisc) { 2569 /* set promiscuous mode, just warn if it fails */ 2570 if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) { 2571 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2572 errno, "BIOCPROMISC"); 2573 status = PCAP_WARNING_PROMISC_NOTSUP; 2574 } 2575 } 2576 2577 #ifdef BIOCSTSTAMP 2578 v = BPF_T_BINTIME; 2579 if (ioctl(p->fd, BIOCSTSTAMP, &v) < 0) { 2580 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2581 errno, "BIOCSTSTAMP"); 2582 status = PCAP_ERROR; 2583 goto bad; 2584 } 2585 #endif /* BIOCSTSTAMP */ 2586 2587 if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) { 2588 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2589 errno, "BIOCGBLEN"); 2590 status = PCAP_ERROR; 2591 goto bad; 2592 } 2593 p->bufsize = v; 2594 #ifdef HAVE_ZEROCOPY_BPF 2595 if (!pb->zerocopy) { 2596 #endif 2597 p->buffer = malloc(p->bufsize); 2598 if (p->buffer == NULL) { 2599 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2600 errno, "malloc"); 2601 status = PCAP_ERROR; 2602 goto bad; 2603 } 2604 #ifdef _AIX 2605 /* For some strange reason this seems to prevent the EFAULT 2606 * problems we have experienced from AIX BPF. */ 2607 memset(p->buffer, 0x0, p->bufsize); 2608 #endif 2609 #ifdef HAVE_ZEROCOPY_BPF 2610 } 2611 #endif 2612 2613 /* 2614 * If there's no filter program installed, there's 2615 * no indication to the kernel of what the snapshot 2616 * length should be, so no snapshotting is done. 2617 * 2618 * Therefore, when we open the device, we install 2619 * an "accept everything" filter with the specified 2620 * snapshot length. 2621 */ 2622 total_insn.code = (u_short)(BPF_RET | BPF_K); 2623 total_insn.jt = 0; 2624 total_insn.jf = 0; 2625 total_insn.k = p->snapshot; 2626 2627 total_prog.bf_len = 1; 2628 total_prog.bf_insns = &total_insn; 2629 if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) { 2630 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 2631 errno, "BIOCSETF"); 2632 status = PCAP_ERROR; 2633 goto bad; 2634 } 2635 2636 /* 2637 * On most BPF platforms, either you can do a "select()" or 2638 * "poll()" on a BPF file descriptor and it works correctly, 2639 * or you can do it and it will return "readable" if the 2640 * hold buffer is full but not if the timeout expires *and* 2641 * a non-blocking read will, if the hold buffer is empty 2642 * but the store buffer isn't empty, rotate the buffers 2643 * and return what packets are available. 2644 * 2645 * In the latter case, the fact that a non-blocking read 2646 * will give you the available packets means you can work 2647 * around the failure of "select()" and "poll()" to wake up 2648 * and return "readable" when the timeout expires by using 2649 * the timeout as the "select()" or "poll()" timeout, putting 2650 * the BPF descriptor into non-blocking mode, and read from 2651 * it regardless of whether "select()" reports it as readable 2652 * or not. 2653 * 2654 * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()" 2655 * won't wake up and return "readable" if the timer expires 2656 * and non-blocking reads return EWOULDBLOCK if the hold 2657 * buffer is empty, even if the store buffer is non-empty. 2658 * 2659 * This means the workaround in question won't work. 2660 * 2661 * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd" 2662 * to -1, which means "sorry, you can't use 'select()' or 'poll()' 2663 * here". On all other BPF platforms, we set it to the FD for 2664 * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking 2665 * read will, if the hold buffer is empty and the store buffer 2666 * isn't empty, rotate the buffers and return what packets are 2667 * there (and in sufficiently recent versions of OpenBSD 2668 * "select()" and "poll()" should work correctly). 2669 * 2670 * XXX - what about AIX? 2671 */ 2672 p->selectable_fd = p->fd; /* assume select() works until we know otherwise */ 2673 if (have_osinfo) { 2674 /* 2675 * We can check what OS this is. 2676 */ 2677 if (strcmp(osinfo.sysname, "FreeBSD") == 0) { 2678 if (strncmp(osinfo.release, "4.3-", 4) == 0 || 2679 strncmp(osinfo.release, "4.4-", 4) == 0) 2680 p->selectable_fd = -1; 2681 } 2682 } 2683 2684 p->read_op = pcap_read_bpf; 2685 p->inject_op = pcap_inject_bpf; 2686 p->setfilter_op = pcap_setfilter_bpf; 2687 p->setdirection_op = pcap_setdirection_bpf; 2688 p->set_datalink_op = pcap_set_datalink_bpf; 2689 p->getnonblock_op = pcap_getnonblock_bpf; 2690 p->setnonblock_op = pcap_setnonblock_bpf; 2691 p->stats_op = pcap_stats_bpf; 2692 p->cleanup_op = pcap_cleanup_bpf; 2693 2694 return (status); 2695 bad: 2696 pcap_cleanup_bpf(p); 2697 return (status); 2698 } 2699 2700 /* 2701 * Not all interfaces can be bound to by BPF, so try to bind to 2702 * the specified interface; return 0 if we fail with 2703 * PCAP_ERROR_NO_SUCH_DEVICE (which means we got an ENXIO when we tried 2704 * to bind, which means this interface isn't in the list of interfaces 2705 * attached to BPF) and 1 otherwise. 2706 */ 2707 static int 2708 check_bpf_bindable(const char *name) 2709 { 2710 int fd; 2711 char errbuf[PCAP_ERRBUF_SIZE]; 2712 2713 /* 2714 * On macOS, we don't do this check if the device name begins 2715 * with "wlt"; at least some versions of macOS (actually, it 2716 * was called "Mac OS X" then...) offer monitor mode capturing 2717 * by having a separate "monitor mode" device for each wireless 2718 * adapter, rather than by implementing the ioctls that 2719 * {Free,Net,Open,DragonFly}BSD provide. Opening that device 2720 * puts the adapter into monitor mode, which, at least for 2721 * some adapters, causes them to deassociate from the network 2722 * with which they're associated. 2723 * 2724 * Instead, we try to open the corresponding "en" device (so 2725 * that we don't end up with, for users without sufficient 2726 * privilege to open capture devices, a list of adapters that 2727 * only includes the wlt devices). 2728 */ 2729 #ifdef __APPLE__ 2730 if (strncmp(name, "wlt", 3) == 0) { 2731 char *en_name; 2732 size_t en_name_len; 2733 2734 /* 2735 * Try to allocate a buffer for the "en" 2736 * device's name. 2737 */ 2738 en_name_len = strlen(name) - 1; 2739 en_name = malloc(en_name_len + 1); 2740 if (en_name == NULL) { 2741 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 2742 errno, "malloc"); 2743 return (-1); 2744 } 2745 strcpy(en_name, "en"); 2746 strcat(en_name, name + 3); 2747 fd = bpf_open_and_bind(en_name, errbuf); 2748 free(en_name); 2749 } else 2750 #endif /* __APPLE */ 2751 fd = bpf_open_and_bind(name, errbuf); 2752 if (fd < 0) { 2753 /* 2754 * Error - was it PCAP_ERROR_NO_SUCH_DEVICE? 2755 */ 2756 if (fd == PCAP_ERROR_NO_SUCH_DEVICE) { 2757 /* 2758 * Yes, so we can't bind to this because it's 2759 * not something supported by BPF. 2760 */ 2761 return (0); 2762 } 2763 /* 2764 * No, so we don't know whether it's supported or not; 2765 * say it is, so that the user can at least try to 2766 * open it and report the error (which is probably 2767 * "you don't have permission to open BPF devices"; 2768 * reporting those interfaces means users will ask 2769 * "why am I getting a permissions error when I try 2770 * to capture" rather than "why am I not seeing any 2771 * interfaces", making the underlying problem clearer). 2772 */ 2773 return (1); 2774 } 2775 2776 /* 2777 * Success. 2778 */ 2779 close(fd); 2780 return (1); 2781 } 2782 2783 #if (defined(__FreeBSD__) || defined(__DragonFly__)) && defined(SIOCIFCREATE2) 2784 static int 2785 get_usb_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_) 2786 { 2787 /* 2788 * XXX - if there's a way to determine whether there's something 2789 * plugged into a given USB bus, use that to determine whether 2790 * this device is "connected" or not. 2791 */ 2792 return (0); 2793 } 2794 2795 static int 2796 finddevs_usb(pcap_if_list_t *devlistp, char *errbuf) 2797 { 2798 DIR *usbdir; 2799 struct dirent *usbitem; 2800 size_t name_max; 2801 char *name; 2802 2803 /* 2804 * We might have USB sniffing support, so try looking for USB 2805 * interfaces. 2806 * 2807 * We want to report a usbusN device for each USB bus, but 2808 * usbusN interfaces might, or might not, exist for them - 2809 * we create one if there isn't already one. 2810 * 2811 * So, instead, we look in /dev/usb for all buses and create 2812 * a "usbusN" device for each one. 2813 */ 2814 usbdir = opendir("/dev/usb"); 2815 if (usbdir == NULL) { 2816 /* 2817 * Just punt. 2818 */ 2819 return (0); 2820 } 2821 2822 /* 2823 * Leave enough room for a 32-bit (10-digit) bus number. 2824 * Yes, that's overkill, but we won't be using 2825 * the buffer very long. 2826 */ 2827 name_max = USBUS_PREFIX_LEN + 10 + 1; 2828 name = malloc(name_max); 2829 if (name == NULL) { 2830 closedir(usbdir); 2831 return (0); 2832 } 2833 while ((usbitem = readdir(usbdir)) != NULL) { 2834 char *p; 2835 size_t busnumlen; 2836 2837 if (strcmp(usbitem->d_name, ".") == 0 || 2838 strcmp(usbitem->d_name, "..") == 0) { 2839 /* 2840 * Ignore these. 2841 */ 2842 continue; 2843 } 2844 p = strchr(usbitem->d_name, '.'); 2845 if (p == NULL) 2846 continue; 2847 busnumlen = p - usbitem->d_name; 2848 memcpy(name, usbus_prefix, USBUS_PREFIX_LEN); 2849 memcpy(name + USBUS_PREFIX_LEN, usbitem->d_name, busnumlen); 2850 *(name + USBUS_PREFIX_LEN + busnumlen) = '\0'; 2851 /* 2852 * There's an entry in this directory for every USB device, 2853 * not for every bus; if there's more than one device on 2854 * the bus, there'll be more than one entry for that bus, 2855 * so we need to avoid adding multiple capture devices 2856 * for each bus. 2857 */ 2858 if (find_or_add_dev(devlistp, name, PCAP_IF_UP, 2859 get_usb_if_flags, NULL, errbuf) == NULL) { 2860 free(name); 2861 closedir(usbdir); 2862 return (PCAP_ERROR); 2863 } 2864 } 2865 free(name); 2866 closedir(usbdir); 2867 return (0); 2868 } 2869 #endif 2870 2871 /* 2872 * Get additional flags for a device, using SIOCGIFMEDIA. 2873 */ 2874 #ifdef SIOCGIFMEDIA 2875 static int 2876 get_if_flags(const char *name, bpf_u_int32 *flags, char *errbuf) 2877 { 2878 int sock; 2879 struct ifmediareq req; 2880 2881 sock = socket(AF_INET, SOCK_DGRAM, 0); 2882 if (sock == -1) { 2883 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, errno, 2884 "Can't create socket to get media information for %s", 2885 name); 2886 return (-1); 2887 } 2888 memset(&req, 0, sizeof(req)); 2889 pcap_strlcpy(req.ifm_name, name, sizeof(req.ifm_name)); 2890 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 2891 if (errno == EOPNOTSUPP || errno == EINVAL || errno == ENOTTY || 2892 errno == ENODEV || errno == EPERM 2893 #ifdef EPWROFF 2894 || errno == EPWROFF 2895 #endif 2896 ) { 2897 /* 2898 * Not supported, so we can't provide any 2899 * additional information. Assume that 2900 * this means that "connected" vs. 2901 * "disconnected" doesn't apply. 2902 * 2903 * The ioctl routine for Apple's pktap devices, 2904 * annoyingly, checks for "are you root?" before 2905 * checking whether the ioctl is valid, so it 2906 * returns EPERM, rather than ENOTSUP, for the 2907 * invalid SIOCGIFMEDIA, unless you're root. 2908 * So, just as we do for some ethtool ioctls 2909 * on Linux, which makes the same mistake, we 2910 * also treat EPERM as meaning "not supported". 2911 * 2912 * And it appears that Apple's llw0 device, which 2913 * appears to be part of the Skywalk subsystem: 2914 * 2915 * http://newosxbook.com/bonus/vol1ch16.html 2916 * 2917 * can sometimes return EPWROFF ("Device power 2918 * is off") for that ioctl, so we treat *that* 2919 * as another indication that we can't get a 2920 * connection status. (If it *isn't* "powered 2921 * off", it's reported as a wireless device, 2922 * complete with an active/inactive state.) 2923 */ 2924 *flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE; 2925 close(sock); 2926 return (0); 2927 } 2928 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, errno, 2929 "SIOCGIFMEDIA on %s failed", name); 2930 close(sock); 2931 return (-1); 2932 } 2933 close(sock); 2934 2935 /* 2936 * OK, what type of network is this? 2937 */ 2938 switch (IFM_TYPE(req.ifm_active)) { 2939 2940 case IFM_IEEE80211: 2941 /* 2942 * Wireless. 2943 */ 2944 *flags |= PCAP_IF_WIRELESS; 2945 break; 2946 } 2947 2948 /* 2949 * Do we know whether it's connected? 2950 */ 2951 if (req.ifm_status & IFM_AVALID) { 2952 /* 2953 * Yes. 2954 */ 2955 if (req.ifm_status & IFM_ACTIVE) { 2956 /* 2957 * It's connected. 2958 */ 2959 *flags |= PCAP_IF_CONNECTION_STATUS_CONNECTED; 2960 } else { 2961 /* 2962 * It's disconnected. 2963 */ 2964 *flags |= PCAP_IF_CONNECTION_STATUS_DISCONNECTED; 2965 } 2966 } 2967 return (0); 2968 } 2969 #else 2970 static int 2971 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_) 2972 { 2973 /* 2974 * Nothing we can do other than mark loopback devices as "the 2975 * connected/disconnected status doesn't apply". 2976 * 2977 * XXX - on Solaris, can we do what the dladm command does, 2978 * i.e. get a connected/disconnected indication from a kstat? 2979 * (Note that you can also get the link speed, and possibly 2980 * other information, from a kstat as well.) 2981 */ 2982 if (*flags & PCAP_IF_LOOPBACK) { 2983 /* 2984 * Loopback devices aren't wireless, and "connected"/ 2985 * "disconnected" doesn't apply to them. 2986 */ 2987 *flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE; 2988 return (0); 2989 } 2990 return (0); 2991 } 2992 #endif 2993 2994 int 2995 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf) 2996 { 2997 /* 2998 * Get the list of regular interfaces first. 2999 */ 3000 if (pcap_findalldevs_interfaces(devlistp, errbuf, check_bpf_bindable, 3001 get_if_flags) == -1) 3002 return (-1); /* failure */ 3003 3004 #if (defined(__FreeBSD__) || defined(__DragonFly__)) && defined(SIOCIFCREATE2) 3005 if (finddevs_usb(devlistp, errbuf) == -1) 3006 return (-1); 3007 #endif 3008 3009 return (0); 3010 } 3011 3012 #ifdef HAVE_BSD_IEEE80211 3013 static int 3014 monitor_mode(pcap_t *p, int set) 3015 { 3016 struct pcap_bpf *pb = p->priv; 3017 int sock; 3018 struct ifmediareq req; 3019 IFM_ULIST_TYPE *media_list; 3020 int i; 3021 int can_do; 3022 struct ifreq ifr; 3023 3024 sock = socket(AF_INET, SOCK_DGRAM, 0); 3025 if (sock == -1) { 3026 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 3027 errno, "can't open socket"); 3028 return (PCAP_ERROR); 3029 } 3030 3031 memset(&req, 0, sizeof req); 3032 pcap_strlcpy(req.ifm_name, p->opt.device, sizeof req.ifm_name); 3033 3034 /* 3035 * Find out how many media types we have. 3036 */ 3037 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 3038 /* 3039 * Can't get the media types. 3040 */ 3041 switch (errno) { 3042 3043 case ENXIO: 3044 /* 3045 * There's no such device. 3046 */ 3047 close(sock); 3048 return (PCAP_ERROR_NO_SUCH_DEVICE); 3049 3050 case EINVAL: 3051 /* 3052 * Interface doesn't support SIOC{G,S}IFMEDIA. 3053 */ 3054 close(sock); 3055 return (PCAP_ERROR_RFMON_NOTSUP); 3056 3057 default: 3058 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 3059 errno, "SIOCGIFMEDIA"); 3060 close(sock); 3061 return (PCAP_ERROR); 3062 } 3063 } 3064 if (req.ifm_count == 0) { 3065 /* 3066 * No media types. 3067 */ 3068 close(sock); 3069 return (PCAP_ERROR_RFMON_NOTSUP); 3070 } 3071 3072 /* 3073 * Allocate a buffer to hold all the media types, and 3074 * get the media types. 3075 */ 3076 media_list = malloc(req.ifm_count * sizeof(*media_list)); 3077 if (media_list == NULL) { 3078 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 3079 errno, "malloc"); 3080 close(sock); 3081 return (PCAP_ERROR); 3082 } 3083 req.ifm_ulist = media_list; 3084 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { 3085 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 3086 errno, "SIOCGIFMEDIA"); 3087 free(media_list); 3088 close(sock); 3089 return (PCAP_ERROR); 3090 } 3091 3092 /* 3093 * Look for an 802.11 "automatic" media type. 3094 * We assume that all 802.11 adapters have that media type, 3095 * and that it will carry the monitor mode supported flag. 3096 */ 3097 can_do = 0; 3098 for (i = 0; i < req.ifm_count; i++) { 3099 if (IFM_TYPE(media_list[i]) == IFM_IEEE80211 3100 && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) { 3101 /* OK, does it do monitor mode? */ 3102 if (media_list[i] & IFM_IEEE80211_MONITOR) { 3103 can_do = 1; 3104 break; 3105 } 3106 } 3107 } 3108 free(media_list); 3109 if (!can_do) { 3110 /* 3111 * This adapter doesn't support monitor mode. 3112 */ 3113 close(sock); 3114 return (PCAP_ERROR_RFMON_NOTSUP); 3115 } 3116 3117 if (set) { 3118 /* 3119 * Don't just check whether we can enable monitor mode, 3120 * do so, if it's not already enabled. 3121 */ 3122 if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) { 3123 /* 3124 * Monitor mode isn't currently on, so turn it on, 3125 * and remember that we should turn it off when the 3126 * pcap_t is closed. 3127 */ 3128 3129 /* 3130 * If we haven't already done so, arrange to have 3131 * "pcap_close_all()" called when we exit. 3132 */ 3133 if (!pcap_do_addexit(p)) { 3134 /* 3135 * "atexit()" failed; don't put the interface 3136 * in monitor mode, just give up. 3137 */ 3138 close(sock); 3139 return (PCAP_ERROR); 3140 } 3141 memset(&ifr, 0, sizeof(ifr)); 3142 (void)pcap_strlcpy(ifr.ifr_name, p->opt.device, 3143 sizeof(ifr.ifr_name)); 3144 ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR; 3145 if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) { 3146 pcap_fmt_errmsg_for_errno(p->errbuf, 3147 PCAP_ERRBUF_SIZE, errno, "SIOCSIFMEDIA"); 3148 close(sock); 3149 return (PCAP_ERROR); 3150 } 3151 3152 pb->must_do_on_close |= MUST_CLEAR_RFMON; 3153 3154 /* 3155 * Add this to the list of pcaps to close when we exit. 3156 */ 3157 pcap_add_to_pcaps_to_close(p); 3158 } 3159 } 3160 return (0); 3161 } 3162 #endif /* HAVE_BSD_IEEE80211 */ 3163 3164 #if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) 3165 /* 3166 * Check whether we have any 802.11 link-layer types; return the best 3167 * of the 802.11 link-layer types if we find one, and return -1 3168 * otherwise. 3169 * 3170 * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the 3171 * best 802.11 link-layer type; any of the other 802.11-plus-radio 3172 * headers are second-best; 802.11 with no radio information is 3173 * the least good. 3174 */ 3175 static int 3176 find_802_11(struct bpf_dltlist *bdlp) 3177 { 3178 int new_dlt; 3179 u_int i; 3180 3181 /* 3182 * Scan the list of DLT_ values, looking for 802.11 values, 3183 * and, if we find any, choose the best of them. 3184 */ 3185 new_dlt = -1; 3186 for (i = 0; i < bdlp->bfl_len; i++) { 3187 switch (bdlp->bfl_list[i]) { 3188 3189 case DLT_IEEE802_11: 3190 /* 3191 * 802.11, but no radio. 3192 * 3193 * Offer this, and select it as the new mode 3194 * unless we've already found an 802.11 3195 * header with radio information. 3196 */ 3197 if (new_dlt == -1) 3198 new_dlt = bdlp->bfl_list[i]; 3199 break; 3200 3201 #ifdef DLT_PRISM_HEADER 3202 case DLT_PRISM_HEADER: 3203 #endif 3204 #ifdef DLT_AIRONET_HEADER 3205 case DLT_AIRONET_HEADER: 3206 #endif 3207 case DLT_IEEE802_11_RADIO_AVS: 3208 /* 3209 * 802.11 with radio, but not radiotap. 3210 * 3211 * Offer this, and select it as the new mode 3212 * unless we've already found the radiotap DLT_. 3213 */ 3214 if (new_dlt != DLT_IEEE802_11_RADIO) 3215 new_dlt = bdlp->bfl_list[i]; 3216 break; 3217 3218 case DLT_IEEE802_11_RADIO: 3219 /* 3220 * 802.11 with radiotap. 3221 * 3222 * Offer this, and select it as the new mode. 3223 */ 3224 new_dlt = bdlp->bfl_list[i]; 3225 break; 3226 3227 default: 3228 /* 3229 * Not 802.11. 3230 */ 3231 break; 3232 } 3233 } 3234 3235 return (new_dlt); 3236 } 3237 #endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */ 3238 3239 #if defined(__APPLE__) && defined(BIOCGDLTLIST) 3240 /* 3241 * Remove non-802.11 header types from the list of DLT_ values, as we're in 3242 * monitor mode, and those header types aren't supported in monitor mode. 3243 */ 3244 static void 3245 remove_non_802_11(pcap_t *p) 3246 { 3247 int i, j; 3248 3249 /* 3250 * Scan the list of DLT_ values and discard non-802.11 ones. 3251 */ 3252 j = 0; 3253 for (i = 0; i < p->dlt_count; i++) { 3254 switch (p->dlt_list[i]) { 3255 3256 case DLT_EN10MB: 3257 case DLT_RAW: 3258 /* 3259 * Not 802.11. Don't offer this one. 3260 */ 3261 continue; 3262 3263 default: 3264 /* 3265 * Just copy this mode over. 3266 */ 3267 break; 3268 } 3269 3270 /* 3271 * Copy this DLT_ value to its new position. 3272 */ 3273 p->dlt_list[j] = p->dlt_list[i]; 3274 j++; 3275 } 3276 3277 /* 3278 * Set the DLT_ count to the number of entries we copied. 3279 */ 3280 p->dlt_count = j; 3281 } 3282 3283 /* 3284 * Remove 802.11 link-layer types from the list of DLT_ values, as 3285 * we're not in monitor mode, and those DLT_ values will switch us 3286 * to monitor mode. 3287 */ 3288 static void 3289 remove_802_11(pcap_t *p) 3290 { 3291 int i, j; 3292 3293 /* 3294 * Scan the list of DLT_ values and discard 802.11 values. 3295 */ 3296 j = 0; 3297 for (i = 0; i < p->dlt_count; i++) { 3298 switch (p->dlt_list[i]) { 3299 3300 case DLT_IEEE802_11: 3301 #ifdef DLT_PRISM_HEADER 3302 case DLT_PRISM_HEADER: 3303 #endif 3304 #ifdef DLT_AIRONET_HEADER 3305 case DLT_AIRONET_HEADER: 3306 #endif 3307 case DLT_IEEE802_11_RADIO: 3308 case DLT_IEEE802_11_RADIO_AVS: 3309 #ifdef DLT_PPI 3310 case DLT_PPI: 3311 #endif 3312 /* 3313 * 802.11. Don't offer this one. 3314 */ 3315 continue; 3316 3317 default: 3318 /* 3319 * Just copy this mode over. 3320 */ 3321 break; 3322 } 3323 3324 /* 3325 * Copy this DLT_ value to its new position. 3326 */ 3327 p->dlt_list[j] = p->dlt_list[i]; 3328 j++; 3329 } 3330 3331 /* 3332 * Set the DLT_ count to the number of entries we copied. 3333 */ 3334 p->dlt_count = j; 3335 } 3336 #endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */ 3337 3338 static int 3339 pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) 3340 { 3341 struct pcap_bpf *pb = p->priv; 3342 3343 /* 3344 * Free any user-mode filter we might happen to have installed. 3345 */ 3346 pcap_freecode(&p->fcode); 3347 3348 /* 3349 * Try to install the kernel filter. 3350 */ 3351 if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) { 3352 /* 3353 * It worked. 3354 */ 3355 pb->filtering_in_kernel = 1; /* filtering in the kernel */ 3356 3357 /* 3358 * Discard any previously-received packets, as they might 3359 * have passed whatever filter was formerly in effect, but 3360 * might not pass this filter (BIOCSETF discards packets 3361 * buffered in the kernel, so you can lose packets in any 3362 * case). 3363 */ 3364 p->cc = 0; 3365 return (0); 3366 } 3367 3368 /* 3369 * We failed. 3370 * 3371 * If it failed with EINVAL, that's probably because the program 3372 * is invalid or too big. Validate it ourselves; if we like it 3373 * (we currently allow backward branches, to support protochain), 3374 * run it in userland. (There's no notion of "too big" for 3375 * userland.) 3376 * 3377 * Otherwise, just give up. 3378 * XXX - if the copy of the program into the kernel failed, 3379 * we will get EINVAL rather than, say, EFAULT on at least 3380 * some kernels. 3381 */ 3382 if (errno != EINVAL) { 3383 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 3384 errno, "BIOCSETF"); 3385 return (-1); 3386 } 3387 3388 /* 3389 * install_bpf_program() validates the program. 3390 * 3391 * XXX - what if we already have a filter in the kernel? 3392 */ 3393 if (install_bpf_program(p, fp) < 0) 3394 return (-1); 3395 pb->filtering_in_kernel = 0; /* filtering in userland */ 3396 return (0); 3397 } 3398 3399 /* 3400 * Set direction flag: Which packets do we accept on a forwarding 3401 * single device? IN, OUT or both? 3402 */ 3403 #if defined(BIOCSDIRECTION) 3404 static int 3405 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d) 3406 { 3407 u_int direction; 3408 const char *direction_name; 3409 3410 /* 3411 * FreeBSD and NetBSD. 3412 */ 3413 switch (d) { 3414 3415 case PCAP_D_IN: 3416 /* 3417 * Incoming, but not outgoing, so accept only 3418 * incoming packets. 3419 */ 3420 direction = BPF_D_IN; 3421 direction_name = "\"incoming only\""; 3422 break; 3423 3424 case PCAP_D_OUT: 3425 /* 3426 * Outgoing, but not incoming, so accept only 3427 * outgoing packets. 3428 */ 3429 direction = BPF_D_OUT; 3430 direction_name = "\"outgoing only\""; 3431 break; 3432 3433 default: 3434 /* 3435 * Incoming and outgoing, so accept both 3436 * incoming and outgoing packets. 3437 * 3438 * It's guaranteed, at this point, that d is a valid 3439 * direction value, so we know that this is PCAP_D_INOUT 3440 * if it's not PCAP_D_IN or PCAP_D_OUT. 3441 */ 3442 direction = BPF_D_INOUT; 3443 direction_name = "\"incoming and outgoing\""; 3444 break; 3445 } 3446 3447 if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) { 3448 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf), 3449 errno, "Cannot set direction to %s", direction_name); 3450 return (-1); 3451 } 3452 return (0); 3453 } 3454 #elif defined(BIOCSDIRFILT) 3455 static int 3456 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d) 3457 { 3458 u_int dirfilt; 3459 const char *direction_name; 3460 3461 /* 3462 * OpenBSD; same functionality, different names, different 3463 * semantics (the flags mean "*don't* capture packets in 3464 * that direction", not "*capture only* packets in that 3465 * direction"). 3466 */ 3467 switch (d) { 3468 3469 case PCAP_D_IN: 3470 /* 3471 * Incoming, but not outgoing, so filter out 3472 * outgoing packets. 3473 */ 3474 dirfilt = BPF_DIRECTION_OUT; 3475 direction_name = "\"incoming only\""; 3476 break; 3477 3478 case PCAP_D_OUT: 3479 /* 3480 * Outgoing, but not incoming, so filter out 3481 * incoming packets. 3482 */ 3483 dirfilt = BPF_DIRECTION_IN; 3484 direction_name = "\"outgoing only\""; 3485 break; 3486 3487 default: 3488 /* 3489 * Incoming and outgoing, so don't filter out 3490 * any packets based on direction. 3491 * 3492 * It's guaranteed, at this point, that d is a valid 3493 * direction value, so we know that this is PCAP_D_INOUT 3494 * if it's not PCAP_D_IN or PCAP_D_OUT. 3495 */ 3496 dirfilt = 0; 3497 direction_name = "\"incoming and outgoing\""; 3498 break; 3499 } 3500 if (ioctl(p->fd, BIOCSDIRFILT, &dirfilt) == -1) { 3501 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf), 3502 errno, "Cannot set direction to %s", direction_name); 3503 return (-1); 3504 } 3505 return (0); 3506 } 3507 #elif defined(BIOCSSEESENT) 3508 static int 3509 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d) 3510 { 3511 u_int seesent; 3512 const char *direction_name; 3513 3514 /* 3515 * OS with just BIOCSSEESENT. 3516 */ 3517 switch (d) { 3518 3519 case PCAP_D_IN: 3520 /* 3521 * Incoming, but not outgoing, so we don't want to 3522 * see transmitted packets. 3523 */ 3524 seesent = 0; 3525 direction_name = "\"incoming only\""; 3526 break; 3527 3528 case PCAP_D_OUT: 3529 /* 3530 * Outgoing, but not incoming; we can't specify that. 3531 */ 3532 snprintf(p->errbuf, sizeof(p->errbuf), 3533 "Setting direction to \"outgoing only\" is not supported on this device"); 3534 return (-1); 3535 3536 default: 3537 /* 3538 * Incoming and outgoing, so we want to see transmitted 3539 * packets. 3540 * 3541 * It's guaranteed, at this point, that d is a valid 3542 * direction value, so we know that this is PCAP_D_INOUT 3543 * if it's not PCAP_D_IN or PCAP_D_OUT. 3544 */ 3545 seesent = 1; 3546 direction_name = "\"incoming and outgoing\""; 3547 break; 3548 } 3549 3550 if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) { 3551 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf), 3552 errno, "Cannot set direction to %s", direction_name); 3553 return (-1); 3554 } 3555 return (0); 3556 } 3557 #else 3558 static int 3559 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d _U_) 3560 { 3561 (void) snprintf(p->errbuf, sizeof(p->errbuf), 3562 "Setting direction is not supported on this device"); 3563 return (-1); 3564 } 3565 #endif 3566 3567 #ifdef BIOCSDLT 3568 static int 3569 pcap_set_datalink_bpf(pcap_t *p, int dlt) 3570 { 3571 if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) { 3572 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf), 3573 errno, "Cannot set DLT %d", dlt); 3574 return (-1); 3575 } 3576 return (0); 3577 } 3578 #else 3579 static int 3580 pcap_set_datalink_bpf(pcap_t *p _U_, int dlt _U_) 3581 { 3582 return (0); 3583 } 3584 #endif 3585 3586 /* 3587 * Platform-specific information. 3588 */ 3589 const char * 3590 pcap_lib_version(void) 3591 { 3592 #ifdef HAVE_ZEROCOPY_BPF 3593 return (PCAP_VERSION_STRING " (with zerocopy support)"); 3594 #else 3595 return (PCAP_VERSION_STRING); 3596 #endif 3597 } 3598