2 * Copyright (c) 1993, 1994, 1995, 1996, 1998
3 * The Regents of the University of California. All rights reserved.
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
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.
24 static const char rcsid[] _U_ =
25 "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.116 2008-09-16 18:42:29 guy Exp $ (LBL)";
32 #include <sys/param.h> /* optionally get BSD define */
33 #ifdef HAVE_ZEROCOPY_BPF
37 #include <sys/socket.h>
39 * <net/bpf.h> defines ioctls, but doesn't include <sys/ioccom.h>.
41 * We include <sys/ioctl.h> as it might be necessary to declare ioctl();
42 * at least on *BSD and Mac OS X, it also defines various SIOC ioctls -
43 * we could include <sys/sockio.h>, but if we're already including
44 * <sys/ioctl.h>, which includes <sys/sockio.h> on those platforms,
45 * there's not much point in doing so.
47 * If we have <sys/ioccom.h>, we include it as well, to handle systems
48 * such as Solaris which don't arrange to include <sys/ioccom.h> if you
49 * include <sys/ioctl.h>
51 #include <sys/ioctl.h>
52 #ifdef HAVE_SYS_IOCCOM_H
53 #include <sys/ioccom.h>
55 #include <sys/utsname.h>
57 #ifdef HAVE_ZEROCOPY_BPF
58 #include <machine/atomic.h>
66 * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the
67 * native OS version, as we need "struct bpf_config" from it.
69 #define PCAP_DONT_INCLUDE_PCAP_BPF_H
71 #include <sys/types.h>
74 * Prevent bpf.h from redefining the DLT_ values to their
75 * IFT_ values, as we're going to return the standard libpcap
76 * values, not IBM's non-standard IFT_ values.
82 #include <net/if_types.h> /* for IFT_ values */
83 #include <sys/sysconfig.h>
84 #include <sys/device.h>
85 #include <sys/cfgodm.h>
89 #define domakedev makedev64
90 #define getmajor major64
91 #define bpf_hdr bpf_hdr32
93 #define domakedev makedev
94 #define getmajor major
95 #endif /* __64BIT__ */
97 #define BPF_NAME "bpf"
99 #define DRIVER_PATH "/usr/lib/drivers"
100 #define BPF_NODE "/dev/bpf"
101 static int bpfloadedflag = 0;
102 static int odmlockid = 0;
104 static int bpf_load(char *errbuf);
121 #ifdef HAVE_NET_IF_MEDIA_H
122 # include <net/if_media.h>
125 #include "pcap-int.h"
128 #include "pcap-dag.h"
129 #endif /* HAVE_DAG_API */
132 #include "pcap-snf.h"
133 #endif /* HAVE_SNF_API */
135 #ifdef HAVE_OS_PROTO_H
136 #include "os-proto.h"
140 # if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__)
141 #define HAVE_BSD_IEEE80211
144 # if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)
145 static int find_802_11(struct bpf_dltlist *);
147 # ifdef HAVE_BSD_IEEE80211
148 static int monitor_mode(pcap_t *, int);
151 # if defined(__APPLE__)
152 static void remove_en(pcap_t *);
153 static void remove_802_11(pcap_t *);
156 # endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */
158 #endif /* BIOCGDLTLIST */
161 * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably
162 * don't get DLT_DOCSIS defined.
165 #define DLT_DOCSIS 143
169 * On OS X, we don't even get any of the 802.11-plus-radio-header DLT_'s
170 * defined, even though some of them are used by various Airport drivers.
172 #ifndef DLT_PRISM_HEADER
173 #define DLT_PRISM_HEADER 119
175 #ifndef DLT_AIRONET_HEADER
176 #define DLT_AIRONET_HEADER 120
178 #ifndef DLT_IEEE802_11_RADIO
179 #define DLT_IEEE802_11_RADIO 127
181 #ifndef DLT_IEEE802_11_RADIO_AVS
182 #define DLT_IEEE802_11_RADIO_AVS 163
185 static int pcap_can_set_rfmon_bpf(pcap_t *p);
186 static int pcap_activate_bpf(pcap_t *p);
187 static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp);
188 static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t);
189 static int pcap_set_datalink_bpf(pcap_t *p, int dlt);
191 #ifdef HAVE_ZEROCOPY_BPF
193 * For zerocopy bpf, we need to override the setnonblock/getnonblock routines
194 * so we don't call select(2) if the pcap handle is in non-blocking mode. We
195 * preserve the timeout supplied by pcap_open functions to make sure it
196 * does not get clobbered if the pcap handle moves between blocking and non-
200 pcap_getnonblock_zbuf(pcap_t *p, char *errbuf)
203 * Use a negative value for the timeout to represent that the
204 * pcap handle is in non-blocking mode.
206 return (p->md.timeout < 0);
210 pcap_setnonblock_zbuf(pcap_t *p, int nonblock, char *errbuf)
213 * Map each value to the corresponding 2's complement, to
214 * preserve the timeout value provided with pcap_set_timeout.
215 * (from pcap-linux.c).
218 if (p->md.timeout >= 0) {
220 * Timeout is non-negative, so we're not already
221 * in non-blocking mode; set it to the 2's
222 * complement, to make it negative, as an
223 * indication that we're in non-blocking mode.
225 p->md.timeout = p->md.timeout * -1 - 1;
228 if (p->md.timeout < 0) {
230 * Timeout is negative, so we're not already
231 * in blocking mode; reverse the previous
232 * operation, to make the timeout non-negative
235 p->md.timeout = (p->md.timeout + 1) * -1;
242 * Zero-copy specific close method. Un-map the shared buffers then call
243 * pcap_cleanup_live_common.
246 pcap_cleanup_zbuf(pcap_t *p)
249 * Delete the mappings. Note that p->buffer gets initialized to one
250 * of the mmapped regions in this case, so do not try and free it
251 * directly; null it out so that pcap_cleanup_live_common() doesn't
254 if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL)
255 (void) munmap(p->md.zbuf1, p->md.zbufsize);
256 if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL)
257 (void) munmap(p->md.zbuf2, p->md.zbufsize);
259 pcap_cleanup_live_common(p);
263 * Zero-copy BPF buffer routines to check for and acknowledge BPF data in
264 * shared memory buffers.
266 * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer,
267 * and set up p->buffer and cc to reflect one if available. Notice that if
268 * there was no prior buffer, we select zbuf1 as this will be the first
269 * buffer filled for a fresh BPF session.
272 pcap_next_zbuf_shm(pcap_t *p, int *cc)
274 struct bpf_zbuf_header *bzh;
276 if (p->md.zbuffer == p->md.zbuf2 || p->md.zbuffer == NULL) {
277 bzh = (struct bpf_zbuf_header *)p->md.zbuf1;
278 if (bzh->bzh_user_gen !=
279 atomic_load_acq_int(&bzh->bzh_kernel_gen)) {
281 p->md.zbuffer = (u_char *)p->md.zbuf1;
282 p->buffer = p->md.zbuffer + sizeof(*bzh);
283 *cc = bzh->bzh_kernel_len;
286 } else if (p->md.zbuffer == p->md.zbuf1) {
287 bzh = (struct bpf_zbuf_header *)p->md.zbuf2;
288 if (bzh->bzh_user_gen !=
289 atomic_load_acq_int(&bzh->bzh_kernel_gen)) {
291 p->md.zbuffer = (u_char *)p->md.zbuf2;
292 p->buffer = p->md.zbuffer + sizeof(*bzh);
293 *cc = bzh->bzh_kernel_len;
302 * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using
303 * select() for data or a timeout, and possibly force rotation of the buffer
304 * in the event we time out or are in immediate mode. Invoke the shared
305 * memory check before doing system calls in order to avoid doing avoidable
309 pcap_next_zbuf(pcap_t *p, int *cc)
318 #define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000))
320 * Start out by seeing whether anything is waiting by checking the
321 * next shared memory buffer for data.
323 data = pcap_next_zbuf_shm(p, cc);
327 * If a previous sleep was interrupted due to signal delivery, make
328 * sure that the timeout gets adjusted accordingly. This requires
329 * that we analyze when the timeout should be been expired, and
330 * subtract the current time from that. If after this operation,
331 * our timeout is less then or equal to zero, handle it like a
334 tmout = p->md.timeout;
336 (void) clock_gettime(CLOCK_MONOTONIC, &cur);
337 if (p->md.interrupted && p->md.timeout) {
338 expire = TSTOMILLI(&p->md.firstsel) + p->md.timeout;
339 tmout = expire - TSTOMILLI(&cur);
342 p->md.interrupted = 0;
343 data = pcap_next_zbuf_shm(p, cc);
346 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) {
347 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
348 "BIOCROTZBUF: %s", strerror(errno));
351 return (pcap_next_zbuf_shm(p, cc));
355 * No data in the buffer, so must use select() to wait for data or
356 * the next timeout. Note that we only call select if the handle
357 * is in blocking mode.
359 if (p->md.timeout >= 0) {
361 FD_SET(p->fd, &r_set);
363 tv.tv_sec = tmout / 1000;
364 tv.tv_usec = (tmout * 1000) % 1000000;
366 r = select(p->fd + 1, &r_set, NULL, NULL,
367 p->md.timeout != 0 ? &tv : NULL);
368 if (r < 0 && errno == EINTR) {
369 if (!p->md.interrupted && p->md.timeout) {
370 p->md.interrupted = 1;
371 p->md.firstsel = cur;
375 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
376 "select: %s", strerror(errno));
380 p->md.interrupted = 0;
382 * Check again for data, which may exist now that we've either been
383 * woken up as a result of data or timed out. Try the "there's data"
384 * case first since it doesn't require a system call.
386 data = pcap_next_zbuf_shm(p, cc);
390 * Try forcing a buffer rotation to dislodge timed out or immediate
393 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) {
394 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
395 "BIOCROTZBUF: %s", strerror(errno));
398 return (pcap_next_zbuf_shm(p, cc));
402 * Notify kernel that we are done with the buffer. We don't reset zbuffer so
403 * that we know which buffer to use next time around.
406 pcap_ack_zbuf(pcap_t *p)
409 atomic_store_rel_int(&p->md.bzh->bzh_user_gen,
410 p->md.bzh->bzh_kernel_gen);
418 pcap_create(const char *device, char *ebuf)
423 if (strstr(device, "dag"))
424 return (dag_create(device, ebuf));
425 #endif /* HAVE_DAG_API */
427 if (strstr(device, "snf"))
428 return (snf_create(device, ebuf));
429 #endif /* HAVE_SNF_API */
431 p = pcap_create_common(device, ebuf);
435 p->activate_op = pcap_activate_bpf;
436 p->can_set_rfmon_op = pcap_can_set_rfmon_bpf;
444 #ifdef HAVE_CLONING_BPF
445 static const char device[] = "/dev/bpf";
448 char device[sizeof "/dev/bpf0000000000"];
453 * Load the bpf driver, if it isn't already loaded,
454 * and create the BPF device entries, if they don't
457 if (bpf_load(p->errbuf) == PCAP_ERROR)
461 #ifdef HAVE_CLONING_BPF
462 if ((fd = open(device, O_RDWR)) == -1 &&
463 (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) {
465 fd = PCAP_ERROR_PERM_DENIED;
468 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
469 "(cannot open device) %s: %s", device, pcap_strerror(errno));
473 * Go through all the minors and find one that isn't in use.
476 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++);
478 * Initially try a read/write open (to allow the inject
479 * method to work). If that fails due to permission
480 * issues, fall back to read-only. This allows a
481 * non-root user to be granted specific access to pcap
482 * capabilities via file permissions.
484 * XXX - we should have an API that has a flag that
485 * controls whether to open read-only or read-write,
486 * so that denial of permission to send (or inability
487 * to send, if sending packets isn't supported on
488 * the device in question) can be indicated at open
491 fd = open(device, O_RDWR);
492 if (fd == -1 && errno == EACCES)
493 fd = open(device, O_RDONLY);
494 } while (fd < 0 && errno == EBUSY);
497 * XXX better message for all minors used
501 fd = PCAP_ERROR_PERM_DENIED;
504 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "(no devices found) %s: %s",
505 device, pcap_strerror(errno));
514 get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf)
516 memset(bdlp, 0, sizeof(*bdlp));
517 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) {
521 bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1));
522 if (bdlp->bfl_list == NULL) {
523 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
524 pcap_strerror(errno));
528 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) {
529 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
530 "BIOCGDLTLIST: %s", pcap_strerror(errno));
531 free(bdlp->bfl_list);
536 * OK, for real Ethernet devices, add DLT_DOCSIS to the
537 * list, so that an application can let you choose it,
538 * in case you're capturing DOCSIS traffic that a Cisco
539 * Cable Modem Termination System is putting out onto
540 * an Ethernet (it doesn't put an Ethernet header onto
541 * the wire, it puts raw DOCSIS frames out on the wire
542 * inside the low-level Ethernet framing).
544 * A "real Ethernet device" is defined here as a device
545 * that has a link-layer type of DLT_EN10MB and that has
546 * no alternate link-layer types; that's done to exclude
547 * 802.11 interfaces (which might or might not be the
548 * right thing to do, but I suspect it is - Ethernet <->
549 * 802.11 bridges would probably badly mishandle frames
550 * that don't have Ethernet headers).
552 * On Solaris with BPF, Ethernet devices also offer
553 * DLT_IPNET, so we, if DLT_IPNET is defined, we don't
554 * treat it as an indication that the device isn't an
557 if (v == DLT_EN10MB) {
559 for (i = 0; i < bdlp->bfl_len; i++) {
560 if (bdlp->bfl_list[i] != DLT_EN10MB
562 && bdlp->bfl_list[i] != DLT_IPNET
571 * We reserved one more slot at the end of
574 bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS;
580 * EINVAL just means "we don't support this ioctl on
581 * this device"; don't treat it as an error.
583 if (errno != EINVAL) {
584 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
585 "BIOCGDLTLIST: %s", pcap_strerror(errno));
594 pcap_can_set_rfmon_bpf(pcap_t *p)
596 #if defined(__APPLE__)
597 struct utsname osinfo;
601 struct bpf_dltlist bdl;
605 * The joys of monitor mode on OS X.
607 * Prior to 10.4, it's not supported at all.
609 * In 10.4, if adapter enN supports monitor mode, there's a
610 * wltN adapter corresponding to it; you open it, instead of
611 * enN, to get monitor mode. You get whatever link-layer
612 * headers it supplies.
614 * In 10.5, and, we assume, later releases, if adapter enN
615 * supports monitor mode, it offers, among its selectable
616 * DLT_ values, values that let you get the 802.11 header;
617 * selecting one of those values puts the adapter into monitor
618 * mode (i.e., you can't get 802.11 headers except in monitor
619 * mode, and you can't get Ethernet headers in monitor mode).
621 if (uname(&osinfo) == -1) {
623 * Can't get the OS version; just say "no".
628 * We assume osinfo.sysname is "Darwin", because
629 * __APPLE__ is defined. We just check the version.
631 if (osinfo.release[0] < '8' && osinfo.release[1] == '.') {
633 * 10.3 (Darwin 7.x) or earlier.
634 * Monitor mode not supported.
638 if (osinfo.release[0] == '8' && osinfo.release[1] == '.') {
640 * 10.4 (Darwin 8.x). s/en/wlt/, and check
641 * whether the device exists.
643 if (strncmp(p->opt.source, "en", 2) != 0) {
645 * Not an enN device; no monitor mode.
649 fd = socket(AF_INET, SOCK_DGRAM, 0);
651 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
652 "socket: %s", pcap_strerror(errno));
655 strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name));
656 strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name));
657 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
670 * Everything else is 10.5 or later; for those,
671 * we just open the enN device, and check whether
672 * we have any 802.11 devices.
674 * First, open a BPF device.
681 * Now bind to the device.
683 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name));
684 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
685 if (errno == ENETDOWN) {
687 * Return a "network down" indication, so that
688 * the application can report that rather than
689 * saying we had a mysterious failure and
690 * suggest that they report a problem to the
691 * libpcap developers.
694 return (PCAP_ERROR_IFACE_NOT_UP);
696 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
698 p->opt.source, pcap_strerror(errno));
705 * We know the default link type -- now determine all the DLTs
706 * this interface supports. If this fails with EINVAL, it's
707 * not fatal; we just don't get to use the feature later.
708 * (We don't care about DLT_DOCSIS, so we pass DLT_NULL
709 * as the default DLT for this adapter.)
711 if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) {
715 if (find_802_11(&bdl) != -1) {
717 * We have an 802.11 DLT, so we can set monitor mode.
724 #endif /* BIOCGDLTLIST */
726 #elif defined(HAVE_BSD_IEEE80211)
729 ret = monitor_mode(p, 0);
730 if (ret == PCAP_ERROR_RFMON_NOTSUP)
731 return (0); /* not an error, just a "can't do" */
733 return (1); /* success */
741 pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps)
746 * "ps_recv" counts packets handed to the filter, not packets
747 * that passed the filter. This includes packets later dropped
748 * because we ran out of buffer space.
750 * "ps_drop" counts packets dropped inside the BPF device
751 * because we ran out of buffer space. It doesn't count
752 * packets dropped by the interface driver. It counts
753 * only packets that passed the filter.
755 * Both statistics include packets not yet read from the kernel
756 * by libpcap, and thus not yet seen by the application.
758 if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) {
759 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s",
760 pcap_strerror(errno));
764 ps->ps_recv = s.bs_recv;
765 ps->ps_drop = s.bs_drop;
771 pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
775 register u_char *bp, *ep;
780 #ifdef HAVE_ZEROCOPY_BPF
786 * Has "pcap_breakloop()" been called?
790 * Yes - clear the flag that indicates that it
791 * has, and return PCAP_ERROR_BREAK to indicate
792 * that we were told to break out of the loop.
795 return (PCAP_ERROR_BREAK);
800 * When reading without zero-copy from a file descriptor, we
801 * use a single buffer and return a length of data in the
802 * buffer. With zero-copy, we update the p->buffer pointer
803 * to point at whatever underlying buffer contains the next
804 * data and update cc to reflect the data found in the
807 #ifdef HAVE_ZEROCOPY_BPF
808 if (p->md.zerocopy) {
809 if (p->buffer != NULL)
811 i = pcap_next_zbuf(p, &cc);
819 cc = read(p->fd, (char *)p->buffer, p->bufsize);
822 /* Don't choke when we get ptraced */
831 * Sigh. More AIX wonderfulness.
833 * For some unknown reason the uiomove()
834 * operation in the bpf kernel extension
835 * used to copy the buffer into user
836 * space sometimes returns EFAULT. I have
837 * no idea why this is the case given that
838 * a kernel debugger shows the user buffer
839 * is correct. This problem appears to
840 * be mostly mitigated by the memset of
841 * the buffer before it is first used.
842 * Very strange.... Shaun Clowes
844 * In any case this means that we shouldn't
845 * treat EFAULT as a fatal error; as we
846 * don't have an API for returning
847 * a "some packets were dropped since
848 * the last packet you saw" indication,
849 * we just ignore EFAULT and keep reading.
859 * The device on which we're capturing
862 * XXX - we should really return
863 * PCAP_ERROR_IFACE_NOT_UP, but
864 * pcap_dispatch() etc. aren't
865 * defined to retur that.
867 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
868 "The interface went down");
871 #if defined(sun) && !defined(BSD) && !defined(__svr4__) && !defined(__SVR4)
873 * Due to a SunOS bug, after 2^31 bytes, the kernel
874 * file offset overflows and read fails with EINVAL.
875 * The lseek() to 0 will fix things.
878 if (lseek(p->fd, 0L, SEEK_CUR) +
880 (void)lseek(p->fd, 0L, SEEK_SET);
886 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s",
887 pcap_strerror(errno));
895 * Loop through each packet.
897 #define bhp ((struct bpf_hdr *)bp)
903 register int caplen, hdrlen;
906 * Has "pcap_breakloop()" been called?
907 * If so, return immediately - if we haven't read any
908 * packets, clear the flag and return PCAP_ERROR_BREAK
909 * to indicate that we were told to break out of the loop,
910 * otherwise leave the flag set, so that the *next* call
911 * will break out of the loop without having read any
912 * packets, and return the number of packets we've
918 return (PCAP_ERROR_BREAK);
926 caplen = bhp->bh_caplen;
927 hdrlen = bhp->bh_hdrlen;
930 * Short-circuit evaluation: if using BPF filter
931 * in kernel, no need to do it now - we already know
932 * the packet passed the filter.
935 * Note: the filter code was generated assuming
936 * that p->fddipad was the amount of padding
937 * before the header, as that's what's required
938 * in the kernel, so we run the filter before
939 * skipping that padding.
943 bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) {
944 struct pcap_pkthdr pkthdr;
946 pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec;
949 * AIX's BPF returns seconds/nanoseconds time
950 * stamps, not seconds/microseconds time stamps.
952 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000;
954 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec;
958 pkthdr.caplen = caplen - pad;
961 if (bhp->bh_datalen > pad)
962 pkthdr.len = bhp->bh_datalen - pad;
967 pkthdr.caplen = caplen;
968 pkthdr.len = bhp->bh_datalen;
970 (*callback)(user, &pkthdr, datap);
971 bp += BPF_WORDALIGN(caplen + hdrlen);
972 if (++n >= cnt && cnt > 0) {
981 bp += BPF_WORDALIGN(caplen + hdrlen);
990 pcap_inject_bpf(pcap_t *p, const void *buf, size_t size)
994 ret = write(p->fd, buf, size);
996 if (ret == -1 && errno == EAFNOSUPPORT) {
998 * In Mac OS X, there's a bug wherein setting the
999 * BIOCSHDRCMPLT flag causes writes to fail; see,
1002 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch
1004 * So, if, on OS X, we get EAFNOSUPPORT from the write, we
1005 * assume it's due to that bug, and turn off that flag
1006 * and try again. If we succeed, it either means that
1007 * somebody applied the fix from that URL, or other patches
1010 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/
1012 * and are running a Darwin kernel with those fixes, or
1013 * that Apple fixed the problem in some OS X release.
1015 u_int spoof_eth_src = 0;
1017 if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
1018 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1019 "send: can't turn off BIOCSHDRCMPLT: %s",
1020 pcap_strerror(errno));
1021 return (PCAP_ERROR);
1025 * Now try the write again.
1027 ret = write(p->fd, buf, size);
1029 #endif /* __APPLE__ */
1031 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
1032 pcap_strerror(errno));
1033 return (PCAP_ERROR);
1040 bpf_odminit(char *errbuf)
1044 if (odm_initialize() == -1) {
1045 if (odm_err_msg(odmerrno, &errstr) == -1)
1046 errstr = "Unknown error";
1047 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1048 "bpf_load: odm_initialize failed: %s",
1050 return (PCAP_ERROR);
1053 if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) {
1054 if (odm_err_msg(odmerrno, &errstr) == -1)
1055 errstr = "Unknown error";
1056 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1057 "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s",
1059 (void)odm_terminate();
1060 return (PCAP_ERROR);
1067 bpf_odmcleanup(char *errbuf)
1071 if (odm_unlock(odmlockid) == -1) {
1072 if (errbuf != NULL) {
1073 if (odm_err_msg(odmerrno, &errstr) == -1)
1074 errstr = "Unknown error";
1075 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1076 "bpf_load: odm_unlock failed: %s",
1079 return (PCAP_ERROR);
1082 if (odm_terminate() == -1) {
1083 if (errbuf != NULL) {
1084 if (odm_err_msg(odmerrno, &errstr) == -1)
1085 errstr = "Unknown error";
1086 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1087 "bpf_load: odm_terminate failed: %s",
1090 return (PCAP_ERROR);
1097 bpf_load(char *errbuf)
1101 int numminors, i, rc;
1104 struct bpf_config cfg_bpf;
1105 struct cfg_load cfg_ld;
1106 struct cfg_kmod cfg_km;
1109 * This is very very close to what happens in the real implementation
1110 * but I've fixed some (unlikely) bug situations.
1115 if (bpf_odminit(errbuf) == PCAP_ERROR)
1116 return (PCAP_ERROR);
1118 major = genmajor(BPF_NAME);
1120 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1121 "bpf_load: genmajor failed: %s", pcap_strerror(errno));
1122 (void)bpf_odmcleanup(NULL);
1123 return (PCAP_ERROR);
1126 minors = getminor(major, &numminors, BPF_NAME);
1128 minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1);
1130 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1131 "bpf_load: genminor failed: %s",
1132 pcap_strerror(errno));
1133 (void)bpf_odmcleanup(NULL);
1134 return (PCAP_ERROR);
1138 if (bpf_odmcleanup(errbuf) == PCAP_ERROR)
1139 return (PCAP_ERROR);
1141 rc = stat(BPF_NODE "0", &sbuf);
1142 if (rc == -1 && errno != ENOENT) {
1143 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1144 "bpf_load: can't stat %s: %s",
1145 BPF_NODE "0", pcap_strerror(errno));
1146 return (PCAP_ERROR);
1149 if (rc == -1 || getmajor(sbuf.st_rdev) != major) {
1150 for (i = 0; i < BPF_MINORS; i++) {
1151 sprintf(buf, "%s%d", BPF_NODE, i);
1153 if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) {
1154 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1155 "bpf_load: can't mknod %s: %s",
1156 buf, pcap_strerror(errno));
1157 return (PCAP_ERROR);
1162 /* Check if the driver is loaded */
1163 memset(&cfg_ld, 0x0, sizeof(cfg_ld));
1165 sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME);
1166 if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) ||
1167 (cfg_ld.kmid == 0)) {
1168 /* Driver isn't loaded, load it now */
1169 if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) {
1170 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1171 "bpf_load: could not load driver: %s",
1173 return (PCAP_ERROR);
1177 /* Configure the driver */
1178 cfg_km.cmd = CFG_INIT;
1179 cfg_km.kmid = cfg_ld.kmid;
1180 cfg_km.mdilen = sizeof(cfg_bpf);
1181 cfg_km.mdiptr = (void *)&cfg_bpf;
1182 for (i = 0; i < BPF_MINORS; i++) {
1183 cfg_bpf.devno = domakedev(major, i);
1184 if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) {
1185 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1186 "bpf_load: could not configure driver: %s",
1188 return (PCAP_ERROR);
1199 * Turn off rfmon mode if necessary.
1202 pcap_cleanup_bpf(pcap_t *p)
1204 #ifdef HAVE_BSD_IEEE80211
1206 struct ifmediareq req;
1210 if (p->md.must_do_on_close != 0) {
1212 * There's something we have to do when closing this
1215 #ifdef HAVE_BSD_IEEE80211
1216 if (p->md.must_do_on_close & MUST_CLEAR_RFMON) {
1218 * We put the interface into rfmon mode;
1219 * take it out of rfmon mode.
1221 * XXX - if somebody else wants it in rfmon
1222 * mode, this code cannot know that, so it'll take
1223 * it out of rfmon mode.
1225 sock = socket(AF_INET, SOCK_DGRAM, 0);
1228 "Can't restore interface flags (socket() failed: %s).\n"
1229 "Please adjust manually.\n",
1232 memset(&req, 0, sizeof(req));
1233 strncpy(req.ifm_name, p->md.device,
1234 sizeof(req.ifm_name));
1235 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
1237 "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n"
1238 "Please adjust manually.\n",
1241 if (req.ifm_current & IFM_IEEE80211_MONITOR) {
1243 * Rfmon mode is currently on;
1246 memset(&ifr, 0, sizeof(ifr));
1247 (void)strncpy(ifr.ifr_name,
1249 sizeof(ifr.ifr_name));
1251 req.ifm_current & ~IFM_IEEE80211_MONITOR;
1252 if (ioctl(sock, SIOCSIFMEDIA,
1255 "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n"
1256 "Please adjust manually.\n",
1264 #endif /* HAVE_BSD_IEEE80211 */
1267 * Take this pcap out of the list of pcaps for which we
1268 * have to take the interface out of some mode.
1270 pcap_remove_from_pcaps_to_close(p);
1271 p->md.must_do_on_close = 0;
1274 #ifdef HAVE_ZEROCOPY_BPF
1276 * In zero-copy mode, p->buffer is just a pointer into one of the two
1277 * memory-mapped buffers, so no need to free it.
1279 if (p->md.zerocopy) {
1280 if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL)
1281 munmap(p->md.zbuf1, p->md.zbufsize);
1282 if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL)
1283 munmap(p->md.zbuf2, p->md.zbufsize);
1287 if (p->md.device != NULL) {
1289 p->md.device = NULL;
1291 pcap_cleanup_live_common(p);
1295 check_setif_failure(pcap_t *p, int error)
1303 if (error == ENXIO) {
1305 * No such device exists.
1308 if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) {
1310 * Monitor mode was requested, and we're trying
1311 * to open a "wltN" device. Assume that this
1312 * is 10.4 and that we were asked to open an
1313 * "enN" device; if that device exists, return
1314 * "monitor mode not supported on the device".
1316 fd = socket(AF_INET, SOCK_DGRAM, 0);
1318 strlcpy(ifr.ifr_name, "en",
1319 sizeof(ifr.ifr_name));
1320 strlcat(ifr.ifr_name, p->opt.source + 3,
1321 sizeof(ifr.ifr_name));
1322 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
1324 * We assume this failed because
1325 * the underlying device doesn't
1328 err = PCAP_ERROR_NO_SUCH_DEVICE;
1329 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1330 "SIOCGIFFLAGS on %s failed: %s",
1331 ifr.ifr_name, pcap_strerror(errno));
1334 * The underlying "enN" device
1335 * exists, but there's no
1336 * corresponding "wltN" device;
1337 * that means that the "enN"
1338 * device doesn't support
1339 * monitor mode, probably because
1340 * it's an Ethernet device rather
1341 * than a wireless device.
1343 err = PCAP_ERROR_RFMON_NOTSUP;
1348 * We can't find out whether there's
1349 * an underlying "enN" device, so
1350 * just report "no such device".
1352 err = PCAP_ERROR_NO_SUCH_DEVICE;
1353 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1354 "socket() failed: %s",
1355 pcap_strerror(errno));
1363 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF failed: %s",
1364 pcap_strerror(errno));
1365 return (PCAP_ERROR_NO_SUCH_DEVICE);
1366 } else if (errno == ENETDOWN) {
1368 * Return a "network down" indication, so that
1369 * the application can report that rather than
1370 * saying we had a mysterious failure and
1371 * suggest that they report a problem to the
1372 * libpcap developers.
1374 return (PCAP_ERROR_IFACE_NOT_UP);
1377 * Some other error; fill in the error string, and
1378 * return PCAP_ERROR.
1380 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s",
1381 p->opt.source, pcap_strerror(errno));
1382 return (PCAP_ERROR);
1387 * Default capture buffer size.
1388 * 32K isn't very much for modern machines with fast networks; we
1389 * pick .5M, as that's the maximum on at least some systems with BPF.
1391 #define DEFAULT_BUFSIZE 524288
1394 pcap_activate_bpf(pcap_t *p)
1399 struct bpf_version bv;
1402 char *wltdev = NULL;
1405 struct bpf_dltlist bdl;
1406 #if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)
1409 #endif /* BIOCGDLTLIST */
1410 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
1411 u_int spoof_eth_src = 1;
1414 struct bpf_insn total_insn;
1415 struct bpf_program total_prog;
1416 struct utsname osinfo;
1419 if (strstr(device, "dag")) {
1420 return dag_open_live(device, snaplen, promisc, to_ms, ebuf);
1422 #endif /* HAVE_DAG_API */
1425 memset(&bdl, 0, sizeof(bdl));
1426 int have_osinfo = 0;
1427 #ifdef HAVE_ZEROCOPY_BPF
1429 u_int bufmode, zbufmax;
1440 if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) {
1441 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s",
1442 pcap_strerror(errno));
1443 status = PCAP_ERROR;
1446 if (bv.bv_major != BPF_MAJOR_VERSION ||
1447 bv.bv_minor < BPF_MINOR_VERSION) {
1448 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1449 "kernel bpf filter out of date");
1450 status = PCAP_ERROR;
1454 p->md.device = strdup(p->opt.source);
1455 if (p->md.device == NULL) {
1456 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s",
1457 pcap_strerror(errno));
1458 status = PCAP_ERROR;
1463 * Try finding a good size for the buffer; 32768 may be too
1464 * big, so keep cutting it in half until we find a size
1465 * that works, or run out of sizes to try. If the default
1466 * is larger, don't make it smaller.
1468 * XXX - there should be a user-accessible hook to set the
1469 * initial buffer size.
1470 * Attempt to find out the version of the OS on which we're running.
1472 if (uname(&osinfo) == 0)
1477 * See comment in pcap_can_set_rfmon_bpf() for an explanation
1478 * of why we check the version number.
1483 * We assume osinfo.sysname is "Darwin", because
1484 * __APPLE__ is defined. We just check the version.
1486 if (osinfo.release[0] < '8' &&
1487 osinfo.release[1] == '.') {
1489 * 10.3 (Darwin 7.x) or earlier.
1491 status = PCAP_ERROR_RFMON_NOTSUP;
1494 if (osinfo.release[0] == '8' &&
1495 osinfo.release[1] == '.') {
1497 * 10.4 (Darwin 8.x). s/en/wlt/
1499 if (strncmp(p->opt.source, "en", 2) != 0) {
1501 * Not an enN device; check
1502 * whether the device even exists.
1504 sockfd = socket(AF_INET, SOCK_DGRAM, 0);
1506 strlcpy(ifr.ifr_name,
1508 sizeof(ifr.ifr_name));
1509 if (ioctl(sockfd, SIOCGIFFLAGS,
1510 (char *)&ifr) < 0) {
1518 status = PCAP_ERROR_NO_SUCH_DEVICE;
1521 "SIOCGIFFLAGS failed: %s",
1522 pcap_strerror(errno));
1524 status = PCAP_ERROR_RFMON_NOTSUP;
1528 * We can't find out whether
1529 * the device exists, so just
1530 * report "no such device".
1532 status = PCAP_ERROR_NO_SUCH_DEVICE;
1535 "socket() failed: %s",
1536 pcap_strerror(errno));
1540 wltdev = malloc(strlen(p->opt.source) + 2);
1541 if (wltdev == NULL) {
1542 (void)snprintf(p->errbuf,
1543 PCAP_ERRBUF_SIZE, "malloc: %s",
1544 pcap_strerror(errno));
1545 status = PCAP_ERROR;
1548 strcpy(wltdev, "wlt");
1549 strcat(wltdev, p->opt.source + 2);
1550 free(p->opt.source);
1551 p->opt.source = wltdev;
1554 * Everything else is 10.5 or later; for those,
1555 * we just open the enN device, and set the DLT.
1559 #endif /* __APPLE__ */
1560 #ifdef HAVE_ZEROCOPY_BPF
1562 * If the BPF extension to set buffer mode is present, try setting
1563 * the mode to zero-copy. If that fails, use regular buffering. If
1564 * it succeeds but other setup fails, return an error to the user.
1566 bufmode = BPF_BUFMODE_ZBUF;
1567 if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) {
1569 * We have zerocopy BPF; use it.
1574 * Set the cleanup and set/get nonblocking mode ops
1575 * as appropriate for zero-copy mode.
1577 p->cleanup_op = pcap_cleanup_zbuf;
1578 p->setnonblock_op = pcap_setnonblock_zbuf;
1579 p->getnonblock_op = pcap_getnonblock_zbuf;
1582 * How to pick a buffer size: first, query the maximum buffer
1583 * size supported by zero-copy. This also lets us quickly
1584 * determine whether the kernel generally supports zero-copy.
1585 * Then, if a buffer size was specified, use that, otherwise
1586 * query the default buffer size, which reflects kernel
1587 * policy for a desired default. Round to the nearest page
1590 if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) {
1591 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s",
1592 pcap_strerror(errno));
1596 if (p->opt.buffer_size != 0) {
1598 * A buffer size was explicitly specified; use it.
1600 v = p->opt.buffer_size;
1602 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) ||
1603 v < DEFAULT_BUFSIZE)
1604 v = DEFAULT_BUFSIZE;
1607 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
1609 p->md.zbufsize = roundup(v, getpagesize());
1610 if (p->md.zbufsize > zbufmax)
1611 p->md.zbufsize = zbufmax;
1612 p->md.zbuf1 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE,
1614 p->md.zbuf2 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE,
1616 if (p->md.zbuf1 == MAP_FAILED || p->md.zbuf2 == MAP_FAILED) {
1617 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s",
1618 pcap_strerror(errno));
1621 bzero(&bz, sizeof(bz));
1622 bz.bz_bufa = p->md.zbuf1;
1623 bz.bz_bufb = p->md.zbuf2;
1624 bz.bz_buflen = p->md.zbufsize;
1625 if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) {
1626 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s",
1627 pcap_strerror(errno));
1630 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name));
1631 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
1632 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s",
1633 p->opt.source, pcap_strerror(errno));
1636 v = p->md.zbufsize - sizeof(struct bpf_zbuf_header);
1641 * We don't have zerocopy BPF.
1642 * Set the buffer size.
1644 if (p->opt.buffer_size != 0) {
1646 * A buffer size was explicitly specified; use it.
1648 if (ioctl(fd, BIOCSBLEN,
1649 (caddr_t)&p->opt.buffer_size) < 0) {
1650 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1651 "BIOCSBLEN: %s: %s", p->opt.source,
1652 pcap_strerror(errno));
1653 status = PCAP_ERROR;
1658 * Now bind to the device.
1660 (void)strncpy(ifr.ifr_name, p->opt.source,
1661 sizeof(ifr.ifr_name));
1662 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
1663 status = check_setif_failure(p, errno);
1668 * No buffer size was explicitly specified.
1670 * Try finding a good size for the buffer;
1671 * DEFAULT_BUFSIZE may be too big, so keep
1672 * cutting it in half until we find a size
1673 * that works, or run out of sizes to try.
1674 * If the default is larger, don't make it smaller.
1676 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) ||
1677 v < DEFAULT_BUFSIZE)
1678 v = DEFAULT_BUFSIZE;
1679 for ( ; v != 0; v >>= 1) {
1681 * Ignore the return value - this is because the
1682 * call fails on BPF systems that don't have
1683 * kernel malloc. And if the call fails, it's
1684 * no big deal, we just continue to use the
1685 * standard buffer size.
1687 (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v);
1689 (void)strncpy(ifr.ifr_name, p->opt.source,
1690 sizeof(ifr.ifr_name));
1691 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0)
1692 break; /* that size worked; we're done */
1694 if (errno != ENOBUFS) {
1695 status = check_setif_failure(p, errno);
1701 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1702 "BIOCSBLEN: %s: No buffer size worked",
1704 status = PCAP_ERROR;
1711 /* Get the data link layer type. */
1712 if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) {
1713 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s",
1714 pcap_strerror(errno));
1715 status = PCAP_ERROR;
1721 * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT.
1744 * We don't know what to map this to yet.
1746 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u",
1748 status = PCAP_ERROR;
1752 #if _BSDI_VERSION - 0 >= 199510
1753 /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */
1768 case 12: /*DLT_C_HDLC*/
1776 * We know the default link type -- now determine all the DLTs
1777 * this interface supports. If this fails with EINVAL, it's
1778 * not fatal; we just don't get to use the feature later.
1780 if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) {
1781 status = PCAP_ERROR;
1784 p->dlt_count = bdl.bfl_len;
1785 p->dlt_list = bdl.bfl_list;
1789 * Monitor mode fun, continued.
1791 * For 10.5 and, we're assuming, later releases, as noted above,
1792 * 802.1 adapters that support monitor mode offer both DLT_EN10MB,
1793 * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information
1794 * DLT_ value. Choosing one of the 802.11 DLT_ values will turn
1797 * Therefore, if the user asked for monitor mode, we filter out
1798 * the DLT_EN10MB value, as you can't get that in monitor mode,
1799 * and, if the user didn't ask for monitor mode, we filter out
1800 * the 802.11 DLT_ values, because selecting those will turn
1801 * monitor mode on. Then, for monitor mode, if an 802.11-plus-
1802 * radio DLT_ value is offered, we try to select that, otherwise
1803 * we try to select DLT_IEEE802_11.
1806 if (isdigit((unsigned)osinfo.release[0]) &&
1807 (osinfo.release[0] == '9' ||
1808 isdigit((unsigned)osinfo.release[1]))) {
1810 * 10.5 (Darwin 9.x), or later.
1812 new_dlt = find_802_11(&bdl);
1813 if (new_dlt != -1) {
1815 * We have at least one 802.11 DLT_ value,
1816 * so this is an 802.11 interface.
1817 * new_dlt is the best of the 802.11
1818 * DLT_ values in the list.
1822 * Our caller wants monitor mode.
1823 * Purge DLT_EN10MB from the list
1824 * of link-layer types, as selecting
1825 * it will keep monitor mode off.
1830 * If the new mode we want isn't
1831 * the default mode, attempt to
1832 * select the new mode.
1835 if (ioctl(p->fd, BIOCSDLT,
1847 * Our caller doesn't want
1848 * monitor mode. Unless this
1849 * is being done by pcap_open_live(),
1850 * purge the 802.11 link-layer types
1851 * from the list, as selecting
1852 * one of them will turn monitor
1861 * The caller requested monitor
1862 * mode, but we have no 802.11
1863 * link-layer types, so they
1866 status = PCAP_ERROR_RFMON_NOTSUP;
1872 #elif defined(HAVE_BSD_IEEE80211)
1874 * *BSD with the new 802.11 ioctls.
1875 * Do we want monitor mode?
1879 * Try to put the interface into monitor mode.
1881 status = monitor_mode(p, 1);
1890 * We're in monitor mode.
1891 * Try to find the best 802.11 DLT_ value and, if we
1892 * succeed, try to switch to that mode if we're not
1893 * already in that mode.
1895 new_dlt = find_802_11(&bdl);
1896 if (new_dlt != -1) {
1898 * We have at least one 802.11 DLT_ value.
1899 * new_dlt is the best of the 802.11
1900 * DLT_ values in the list.
1902 * If the new mode we want isn't the default mode,
1903 * attempt to select the new mode.
1906 if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) {
1908 * We succeeded; make this the
1916 #endif /* various platforms */
1917 #endif /* BIOCGDLTLIST */
1920 * If this is an Ethernet device, and we don't have a DLT_ list,
1921 * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give
1922 * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to
1923 * do, but there's not much we can do about that without finding
1924 * some other way of determining whether it's an Ethernet or 802.11
1927 if (v == DLT_EN10MB && p->dlt_count == 0) {
1928 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
1930 * If that fails, just leave the list empty.
1932 if (p->dlt_list != NULL) {
1933 p->dlt_list[0] = DLT_EN10MB;
1934 p->dlt_list[1] = DLT_DOCSIS;
1940 p->fddipad = PCAP_FDDIPAD;
1946 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
1948 * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so
1949 * the link-layer source address isn't forcibly overwritten.
1950 * (Should we ignore errors? Should we do this only if
1951 * we're open for writing?)
1953 * XXX - I seem to remember some packet-sending bug in some
1954 * BSDs - check CVS log for "bpf.c"?
1956 if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
1957 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1958 "BIOCSHDRCMPLT: %s", pcap_strerror(errno));
1959 status = PCAP_ERROR;
1964 #ifdef HAVE_ZEROCOPY_BPF
1965 if (p->md.timeout != 0 && !p->md.zerocopy) {
1967 if (p->md.timeout) {
1970 * XXX - is this seconds/nanoseconds in AIX?
1971 * (Treating it as such doesn't fix the timeout
1972 * problem described below.)
1974 * XXX - Mac OS X 10.6 mishandles BIOCSRTIMEOUT in
1975 * 64-bit userland - it takes, as an argument, a
1976 * "struct BPF_TIMEVAL", which has 32-bit tv_sec
1977 * and tv_usec, rather than a "struct timeval".
1979 * If this platform defines "struct BPF_TIMEVAL",
1980 * we check whether the structure size in BIOCSRTIMEOUT
1981 * is that of a "struct timeval" and, if not, we use
1982 * a "struct BPF_TIMEVAL" rather than a "struct timeval".
1983 * (That way, if the bug is fixed in a future release,
1984 * we will still do the right thing.)
1987 #ifdef HAVE_STRUCT_BPF_TIMEVAL
1988 struct BPF_TIMEVAL bpf_to;
1990 if (IOCPARM_LEN(BIOCSRTIMEOUT) != sizeof(struct timeval)) {
1991 bpf_to.tv_sec = p->md.timeout / 1000;
1992 bpf_to.tv_usec = (p->md.timeout * 1000) % 1000000;
1993 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&bpf_to) < 0) {
1994 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1995 "BIOCSRTIMEOUT: %s", pcap_strerror(errno));
1996 status = PCAP_ERROR;
2001 to.tv_sec = p->md.timeout / 1000;
2002 to.tv_usec = (p->md.timeout * 1000) % 1000000;
2003 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) {
2004 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2005 "BIOCSRTIMEOUT: %s", pcap_strerror(errno));
2006 status = PCAP_ERROR;
2009 #ifdef HAVE_STRUCT_BPF_TIMEVAL
2015 #ifdef BIOCIMMEDIATE
2017 * Darren Reed notes that
2019 * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the
2020 * timeout appears to be ignored and it waits until the buffer
2021 * is filled before returning. The result of not having it
2022 * set is almost worse than useless if your BPF filter
2023 * is reducing things to only a few packets (i.e. one every
2026 * so we turn BIOCIMMEDIATE mode on if this is AIX.
2028 * We don't turn it on for other platforms, as that means we
2029 * get woken up for every packet, which may not be what we want;
2030 * in the Winter 1993 USENIX paper on BPF, they say:
2032 * Since a process might want to look at every packet on a
2033 * network and the time between packets can be only a few
2034 * microseconds, it is not possible to do a read system call
2035 * per packet and BPF must collect the data from several
2036 * packets and return it as a unit when the monitoring
2037 * application does a read.
2039 * which I infer is the reason for the timeout - it means we
2040 * wait that amount of time, in the hopes that more packets
2041 * will arrive and we'll get them all with one read.
2043 * Setting BIOCIMMEDIATE mode on FreeBSD (and probably other
2044 * BSDs) causes the timeout to be ignored.
2046 * On the other hand, some platforms (e.g., Linux) don't support
2047 * timeouts, they just hand stuff to you as soon as it arrives;
2048 * if that doesn't cause a problem on those platforms, it may
2049 * be OK to have BIOCIMMEDIATE mode on BSD as well.
2051 * (Note, though, that applications may depend on the read
2052 * completing, even if no packets have arrived, when the timeout
2053 * expires, e.g. GUI applications that have to check for input
2054 * while waiting for packets to arrive; a non-zero timeout
2055 * prevents "select()" from working right on FreeBSD and
2056 * possibly other BSDs, as the timer doesn't start until a
2057 * "read()" is done, so the timer isn't in effect if the
2058 * application is blocked on a "select()", and the "select()"
2059 * doesn't get woken up for a BPF device until the buffer
2063 if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) {
2064 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s",
2065 pcap_strerror(errno));
2066 status = PCAP_ERROR;
2069 #endif /* BIOCIMMEDIATE */
2072 if (p->opt.promisc) {
2073 /* set promiscuous mode, just warn if it fails */
2074 if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) {
2075 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s",
2076 pcap_strerror(errno));
2077 status = PCAP_WARNING_PROMISC_NOTSUP;
2081 if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) {
2082 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s",
2083 pcap_strerror(errno));
2084 status = PCAP_ERROR;
2088 #ifdef HAVE_ZEROCOPY_BPF
2089 if (!p->md.zerocopy) {
2091 p->buffer = (u_char *)malloc(p->bufsize);
2092 if (p->buffer == NULL) {
2093 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s",
2094 pcap_strerror(errno));
2095 status = PCAP_ERROR;
2099 /* For some strange reason this seems to prevent the EFAULT
2100 * problems we have experienced from AIX BPF. */
2101 memset(p->buffer, 0x0, p->bufsize);
2103 #ifdef HAVE_ZEROCOPY_BPF
2108 * If there's no filter program installed, there's
2109 * no indication to the kernel of what the snapshot
2110 * length should be, so no snapshotting is done.
2112 * Therefore, when we open the device, we install
2113 * an "accept everything" filter with the specified
2116 total_insn.code = (u_short)(BPF_RET | BPF_K);
2119 total_insn.k = p->snapshot;
2121 total_prog.bf_len = 1;
2122 total_prog.bf_insns = &total_insn;
2123 if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) {
2124 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
2125 pcap_strerror(errno));
2126 status = PCAP_ERROR;
2131 * On most BPF platforms, either you can do a "select()" or
2132 * "poll()" on a BPF file descriptor and it works correctly,
2133 * or you can do it and it will return "readable" if the
2134 * hold buffer is full but not if the timeout expires *and*
2135 * a non-blocking read will, if the hold buffer is empty
2136 * but the store buffer isn't empty, rotate the buffers
2137 * and return what packets are available.
2139 * In the latter case, the fact that a non-blocking read
2140 * will give you the available packets means you can work
2141 * around the failure of "select()" and "poll()" to wake up
2142 * and return "readable" when the timeout expires by using
2143 * the timeout as the "select()" or "poll()" timeout, putting
2144 * the BPF descriptor into non-blocking mode, and read from
2145 * it regardless of whether "select()" reports it as readable
2148 * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()"
2149 * won't wake up and return "readable" if the timer expires
2150 * and non-blocking reads return EWOULDBLOCK if the hold
2151 * buffer is empty, even if the store buffer is non-empty.
2153 * This means the workaround in question won't work.
2155 * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd"
2156 * to -1, which means "sorry, you can't use 'select()' or 'poll()'
2157 * here". On all other BPF platforms, we set it to the FD for
2158 * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking
2159 * read will, if the hold buffer is empty and the store buffer
2160 * isn't empty, rotate the buffers and return what packets are
2161 * there (and in sufficiently recent versions of OpenBSD
2162 * "select()" and "poll()" should work correctly).
2164 * XXX - what about AIX?
2166 p->selectable_fd = p->fd; /* assume select() works until we know otherwise */
2169 * We can check what OS this is.
2171 if (strcmp(osinfo.sysname, "FreeBSD") == 0) {
2172 if (strncmp(osinfo.release, "4.3-", 4) == 0 ||
2173 strncmp(osinfo.release, "4.4-", 4) == 0)
2174 p->selectable_fd = -1;
2178 p->read_op = pcap_read_bpf;
2179 p->inject_op = pcap_inject_bpf;
2180 p->setfilter_op = pcap_setfilter_bpf;
2181 p->setdirection_op = pcap_setdirection_bpf;
2182 p->set_datalink_op = pcap_set_datalink_bpf;
2183 p->getnonblock_op = pcap_getnonblock_fd;
2184 p->setnonblock_op = pcap_setnonblock_fd;
2185 p->stats_op = pcap_stats_bpf;
2186 p->cleanup_op = pcap_cleanup_bpf;
2190 pcap_cleanup_bpf(p);
2195 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
2198 if (dag_platform_finddevs(alldevsp, errbuf) < 0)
2200 #endif /* HAVE_DAG_API */
2202 if (snf_platform_finddevs(alldevsp, errbuf) < 0)
2204 #endif /* HAVE_SNF_API */
2209 #ifdef HAVE_BSD_IEEE80211
2211 monitor_mode(pcap_t *p, int set)
2214 struct ifmediareq req;
2220 sock = socket(AF_INET, SOCK_DGRAM, 0);
2222 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s",
2223 pcap_strerror(errno));
2224 return (PCAP_ERROR);
2227 memset(&req, 0, sizeof req);
2228 strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name);
2231 * Find out how many media types we have.
2233 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
2235 * Can't get the media types.
2237 if (errno == EINVAL) {
2239 * Interface doesn't support SIOC{G,S}IFMEDIA.
2242 return (PCAP_ERROR_RFMON_NOTSUP);
2244 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA 1: %s",
2245 pcap_strerror(errno));
2247 return (PCAP_ERROR);
2249 if (req.ifm_count == 0) {
2254 return (PCAP_ERROR_RFMON_NOTSUP);
2258 * Allocate a buffer to hold all the media types, and
2259 * get the media types.
2261 media_list = malloc(req.ifm_count * sizeof(int));
2262 if (media_list == NULL) {
2263 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s",
2264 pcap_strerror(errno));
2266 return (PCAP_ERROR);
2268 req.ifm_ulist = media_list;
2269 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
2270 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s",
2271 pcap_strerror(errno));
2274 return (PCAP_ERROR);
2278 * Look for an 802.11 "automatic" media type.
2279 * We assume that all 802.11 adapters have that media type,
2280 * and that it will carry the monitor mode supported flag.
2283 for (i = 0; i < req.ifm_count; i++) {
2284 if (IFM_TYPE(media_list[i]) == IFM_IEEE80211
2285 && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) {
2286 /* OK, does it do monitor mode? */
2287 if (media_list[i] & IFM_IEEE80211_MONITOR) {
2296 * This adapter doesn't support monitor mode.
2299 return (PCAP_ERROR_RFMON_NOTSUP);
2304 * Don't just check whether we can enable monitor mode,
2305 * do so, if it's not already enabled.
2307 if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) {
2309 * Monitor mode isn't currently on, so turn it on,
2310 * and remember that we should turn it off when the
2315 * If we haven't already done so, arrange to have
2316 * "pcap_close_all()" called when we exit.
2318 if (!pcap_do_addexit(p)) {
2320 * "atexit()" failed; don't put the interface
2321 * in monitor mode, just give up.
2323 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2326 return (PCAP_ERROR);
2328 memset(&ifr, 0, sizeof(ifr));
2329 (void)strncpy(ifr.ifr_name, p->opt.source,
2330 sizeof(ifr.ifr_name));
2331 ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR;
2332 if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) {
2333 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2334 "SIOCSIFMEDIA: %s", pcap_strerror(errno));
2336 return (PCAP_ERROR);
2339 p->md.must_do_on_close |= MUST_CLEAR_RFMON;
2342 * Add this to the list of pcaps to close when we exit.
2344 pcap_add_to_pcaps_to_close(p);
2349 #endif /* HAVE_BSD_IEEE80211 */
2351 #if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211))
2353 * Check whether we have any 802.11 link-layer types; return the best
2354 * of the 802.11 link-layer types if we find one, and return -1
2357 * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the
2358 * best 802.11 link-layer type; any of the other 802.11-plus-radio
2359 * headers are second-best; 802.11 with no radio information is
2363 find_802_11(struct bpf_dltlist *bdlp)
2369 * Scan the list of DLT_ values, looking for 802.11 values,
2370 * and, if we find any, choose the best of them.
2373 for (i = 0; i < bdlp->bfl_len; i++) {
2374 switch (bdlp->bfl_list[i]) {
2376 case DLT_IEEE802_11:
2378 * 802.11, but no radio.
2380 * Offer this, and select it as the new mode
2381 * unless we've already found an 802.11
2382 * header with radio information.
2385 new_dlt = bdlp->bfl_list[i];
2388 case DLT_PRISM_HEADER:
2389 case DLT_AIRONET_HEADER:
2390 case DLT_IEEE802_11_RADIO_AVS:
2392 * 802.11 with radio, but not radiotap.
2394 * Offer this, and select it as the new mode
2395 * unless we've already found the radiotap DLT_.
2397 if (new_dlt != DLT_IEEE802_11_RADIO)
2398 new_dlt = bdlp->bfl_list[i];
2401 case DLT_IEEE802_11_RADIO:
2403 * 802.11 with radiotap.
2405 * Offer this, and select it as the new mode.
2407 new_dlt = bdlp->bfl_list[i];
2420 #endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */
2422 #if defined(__APPLE__) && defined(BIOCGDLTLIST)
2424 * Remove DLT_EN10MB from the list of DLT_ values, as we're in monitor mode,
2425 * and DLT_EN10MB isn't supported in monitor mode.
2428 remove_en(pcap_t *p)
2433 * Scan the list of DLT_ values and discard DLT_EN10MB.
2436 for (i = 0; i < p->dlt_count; i++) {
2437 switch (p->dlt_list[i]) {
2441 * Don't offer this one.
2447 * Just copy this mode over.
2453 * Copy this DLT_ value to its new position.
2455 p->dlt_list[j] = p->dlt_list[i];
2460 * Set the DLT_ count to the number of entries we copied.
2466 * Remove 802.11 link-layer types from the list of DLT_ values, as
2467 * we're not in monitor mode, and those DLT_ values will switch us
2471 remove_802_11(pcap_t *p)
2476 * Scan the list of DLT_ values and discard 802.11 values.
2479 for (i = 0; i < p->dlt_count; i++) {
2480 switch (p->dlt_list[i]) {
2482 case DLT_IEEE802_11:
2483 case DLT_PRISM_HEADER:
2484 case DLT_AIRONET_HEADER:
2485 case DLT_IEEE802_11_RADIO:
2486 case DLT_IEEE802_11_RADIO_AVS:
2488 * 802.11. Don't offer this one.
2494 * Just copy this mode over.
2500 * Copy this DLT_ value to its new position.
2502 p->dlt_list[j] = p->dlt_list[i];
2507 * Set the DLT_ count to the number of entries we copied.
2511 #endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */
2514 pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp)
2517 * Free any user-mode filter we might happen to have installed.
2519 pcap_freecode(&p->fcode);
2522 * Try to install the kernel filter.
2524 if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) {
2528 p->md.use_bpf = 1; /* filtering in the kernel */
2531 * Discard any previously-received packets, as they might
2532 * have passed whatever filter was formerly in effect, but
2533 * might not pass this filter (BIOCSETF discards packets
2534 * buffered in the kernel, so you can lose packets in any
2544 * If it failed with EINVAL, that's probably because the program
2545 * is invalid or too big. Validate it ourselves; if we like it
2546 * (we currently allow backward branches, to support protochain),
2547 * run it in userland. (There's no notion of "too big" for
2550 * Otherwise, just give up.
2551 * XXX - if the copy of the program into the kernel failed,
2552 * we will get EINVAL rather than, say, EFAULT on at least
2555 if (errno != EINVAL) {
2556 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
2557 pcap_strerror(errno));
2562 * install_bpf_program() validates the program.
2564 * XXX - what if we already have a filter in the kernel?
2566 if (install_bpf_program(p, fp) < 0)
2568 p->md.use_bpf = 0; /* filtering in userland */
2573 * Set direction flag: Which packets do we accept on a forwarding
2574 * single device? IN, OUT or both?
2577 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d)
2579 #if defined(BIOCSDIRECTION)
2582 direction = (d == PCAP_D_IN) ? BPF_D_IN :
2583 ((d == PCAP_D_OUT) ? BPF_D_OUT : BPF_D_INOUT);
2584 if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) {
2585 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2586 "Cannot set direction to %s: %s",
2587 (d == PCAP_D_IN) ? "PCAP_D_IN" :
2588 ((d == PCAP_D_OUT) ? "PCAP_D_OUT" : "PCAP_D_INOUT"),
2593 #elif defined(BIOCSSEESENT)
2597 * We don't support PCAP_D_OUT.
2599 if (d == PCAP_D_OUT) {
2600 snprintf(p->errbuf, sizeof(p->errbuf),
2601 "Setting direction to PCAP_D_OUT is not supported on BPF");
2605 seesent = (d == PCAP_D_INOUT);
2606 if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) {
2607 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2608 "Cannot set direction to %s: %s",
2609 (d == PCAP_D_INOUT) ? "PCAP_D_INOUT" : "PCAP_D_IN",
2615 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2616 "This system doesn't support BIOCSSEESENT, so the direction can't be set");
2622 pcap_set_datalink_bpf(pcap_t *p, int dlt)
2625 if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) {
2626 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2627 "Cannot set DLT %d: %s", dlt, strerror(errno));