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