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
36 #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);
192 * For zerocopy bpf, the setnonblock/getnonblock routines need to modify
193 * p->md.timeout so we don't call select(2) if the pcap handle is in non-
194 * blocking mode. We preserve the timeout supplied by pcap_open functions
195 * to make sure it does not get clobbered if the pcap handle moves between
196 * blocking and non-blocking mode.
199 pcap_getnonblock_bpf(pcap_t *p, char *errbuf)
201 #ifdef HAVE_ZEROCOPY_BPF
202 if (p->md.zerocopy) {
204 * Use a negative value for the timeout to represent that the
205 * pcap handle is in non-blocking mode.
207 return (p->md.timeout < 0);
210 return (pcap_getnonblock_fd(p, errbuf));
214 pcap_setnonblock_bpf(pcap_t *p, int nonblock, char *errbuf)
216 #ifdef HAVE_ZEROCOPY_BPF
217 if (p->md.zerocopy) {
219 * Map each value to the corresponding 2's complement, to
220 * preserve the timeout value provided with pcap_set_timeout.
221 * (from pcap-linux.c).
224 if (p->md.timeout >= 0) {
226 * Timeout is non-negative, so we're not
227 * currently in non-blocking mode; set it
228 * to the 2's complement, to make it
229 * negative, as an indication that we're
230 * in non-blocking mode.
232 p->md.timeout = p->md.timeout * -1 - 1;
235 if (p->md.timeout < 0) {
237 * Timeout is negative, so we're currently
238 * in blocking mode; reverse the previous
239 * operation, to make the timeout non-negative
242 p->md.timeout = (p->md.timeout + 1) * -1;
248 return (pcap_setnonblock_fd(p, nonblock, errbuf));
251 #ifdef HAVE_ZEROCOPY_BPF
253 * Zero-copy BPF buffer routines to check for and acknowledge BPF data in
254 * shared memory buffers.
256 * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer,
257 * and set up p->buffer and cc to reflect one if available. Notice that if
258 * there was no prior buffer, we select zbuf1 as this will be the first
259 * buffer filled for a fresh BPF session.
262 pcap_next_zbuf_shm(pcap_t *p, int *cc)
264 struct bpf_zbuf_header *bzh;
266 if (p->md.zbuffer == p->md.zbuf2 || p->md.zbuffer == NULL) {
267 bzh = (struct bpf_zbuf_header *)p->md.zbuf1;
268 if (bzh->bzh_user_gen !=
269 atomic_load_acq_int(&bzh->bzh_kernel_gen)) {
271 p->md.zbuffer = (u_char *)p->md.zbuf1;
272 p->buffer = p->md.zbuffer + sizeof(*bzh);
273 *cc = bzh->bzh_kernel_len;
276 } else if (p->md.zbuffer == p->md.zbuf1) {
277 bzh = (struct bpf_zbuf_header *)p->md.zbuf2;
278 if (bzh->bzh_user_gen !=
279 atomic_load_acq_int(&bzh->bzh_kernel_gen)) {
281 p->md.zbuffer = (u_char *)p->md.zbuf2;
282 p->buffer = p->md.zbuffer + sizeof(*bzh);
283 *cc = bzh->bzh_kernel_len;
292 * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using
293 * select() for data or a timeout, and possibly force rotation of the buffer
294 * in the event we time out or are in immediate mode. Invoke the shared
295 * memory check before doing system calls in order to avoid doing avoidable
299 pcap_next_zbuf(pcap_t *p, int *cc)
308 #define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000))
310 * Start out by seeing whether anything is waiting by checking the
311 * next shared memory buffer for data.
313 data = pcap_next_zbuf_shm(p, cc);
317 * If a previous sleep was interrupted due to signal delivery, make
318 * sure that the timeout gets adjusted accordingly. This requires
319 * that we analyze when the timeout should be been expired, and
320 * subtract the current time from that. If after this operation,
321 * our timeout is less then or equal to zero, handle it like a
324 tmout = p->md.timeout;
326 (void) clock_gettime(CLOCK_MONOTONIC, &cur);
327 if (p->md.interrupted && p->md.timeout) {
328 expire = TSTOMILLI(&p->md.firstsel) + p->md.timeout;
329 tmout = expire - TSTOMILLI(&cur);
332 p->md.interrupted = 0;
333 data = pcap_next_zbuf_shm(p, cc);
336 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) {
337 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
338 "BIOCROTZBUF: %s", strerror(errno));
341 return (pcap_next_zbuf_shm(p, cc));
345 * No data in the buffer, so must use select() to wait for data or
346 * the next timeout. Note that we only call select if the handle
347 * is in blocking mode.
349 if (p->md.timeout >= 0) {
351 FD_SET(p->fd, &r_set);
353 tv.tv_sec = tmout / 1000;
354 tv.tv_usec = (tmout * 1000) % 1000000;
356 r = select(p->fd + 1, &r_set, NULL, NULL,
357 p->md.timeout != 0 ? &tv : NULL);
358 if (r < 0 && errno == EINTR) {
359 if (!p->md.interrupted && p->md.timeout) {
360 p->md.interrupted = 1;
361 p->md.firstsel = cur;
365 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
366 "select: %s", strerror(errno));
370 p->md.interrupted = 0;
372 * Check again for data, which may exist now that we've either been
373 * woken up as a result of data or timed out. Try the "there's data"
374 * case first since it doesn't require a system call.
376 data = pcap_next_zbuf_shm(p, cc);
380 * Try forcing a buffer rotation to dislodge timed out or immediate
383 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) {
384 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
385 "BIOCROTZBUF: %s", strerror(errno));
388 return (pcap_next_zbuf_shm(p, cc));
392 * Notify kernel that we are done with the buffer. We don't reset zbuffer so
393 * that we know which buffer to use next time around.
396 pcap_ack_zbuf(pcap_t *p)
399 atomic_store_rel_int(&p->md.bzh->bzh_user_gen,
400 p->md.bzh->bzh_kernel_gen);
405 #endif /* HAVE_ZEROCOPY_BPF */
408 pcap_create(const char *device, char *ebuf)
413 if (strstr(device, "dag"))
414 return (dag_create(device, ebuf));
415 #endif /* HAVE_DAG_API */
417 if (strstr(device, "snf"))
418 return (snf_create(device, ebuf));
419 #endif /* HAVE_SNF_API */
421 p = pcap_create_common(device, ebuf);
425 p->activate_op = pcap_activate_bpf;
426 p->can_set_rfmon_op = pcap_can_set_rfmon_bpf;
431 * On success, returns a file descriptor for a BPF device.
432 * On failure, returns a PCAP_ERROR_ value, and sets p->errbuf.
438 #ifdef HAVE_CLONING_BPF
439 static const char device[] = "/dev/bpf";
442 char device[sizeof "/dev/bpf0000000000"];
447 * Load the bpf driver, if it isn't already loaded,
448 * and create the BPF device entries, if they don't
451 if (bpf_load(p->errbuf) == PCAP_ERROR)
455 #ifdef HAVE_CLONING_BPF
456 if ((fd = open(device, O_RDWR)) == -1 &&
457 (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) {
459 fd = PCAP_ERROR_PERM_DENIED;
462 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
463 "(cannot open device) %s: %s", device, pcap_strerror(errno));
467 * Go through all the minors and find one that isn't in use.
470 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++);
472 * Initially try a read/write open (to allow the inject
473 * method to work). If that fails due to permission
474 * issues, fall back to read-only. This allows a
475 * non-root user to be granted specific access to pcap
476 * capabilities via file permissions.
478 * XXX - we should have an API that has a flag that
479 * controls whether to open read-only or read-write,
480 * so that denial of permission to send (or inability
481 * to send, if sending packets isn't supported on
482 * the device in question) can be indicated at open
485 fd = open(device, O_RDWR);
486 if (fd == -1 && errno == EACCES)
487 fd = open(device, O_RDONLY);
488 } while (fd < 0 && errno == EBUSY);
491 * XXX better message for all minors used
500 * /dev/bpf0 doesn't exist, which
501 * means we probably have no BPF
504 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
505 "(there are no BPF devices)");
508 * We got EBUSY on at least one
509 * BPF device, so we have BPF
510 * devices, but all the ones
511 * that exist are busy.
513 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
514 "(all BPF devices are busy)");
520 * Got EACCES on the last device we tried,
521 * and EBUSY on all devices before that,
524 fd = PCAP_ERROR_PERM_DENIED;
525 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
526 "(cannot open BPF device) %s: %s", device,
527 pcap_strerror(errno));
532 * Some other problem.
535 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
536 "(cannot open BPF device) %s: %s", device,
537 pcap_strerror(errno));
548 get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf)
550 memset(bdlp, 0, sizeof(*bdlp));
551 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) {
555 bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1));
556 if (bdlp->bfl_list == NULL) {
557 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
558 pcap_strerror(errno));
562 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) {
563 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
564 "BIOCGDLTLIST: %s", pcap_strerror(errno));
565 free(bdlp->bfl_list);
570 * OK, for real Ethernet devices, add DLT_DOCSIS to the
571 * list, so that an application can let you choose it,
572 * in case you're capturing DOCSIS traffic that a Cisco
573 * Cable Modem Termination System is putting out onto
574 * an Ethernet (it doesn't put an Ethernet header onto
575 * the wire, it puts raw DOCSIS frames out on the wire
576 * inside the low-level Ethernet framing).
578 * A "real Ethernet device" is defined here as a device
579 * that has a link-layer type of DLT_EN10MB and that has
580 * no alternate link-layer types; that's done to exclude
581 * 802.11 interfaces (which might or might not be the
582 * right thing to do, but I suspect it is - Ethernet <->
583 * 802.11 bridges would probably badly mishandle frames
584 * that don't have Ethernet headers).
586 * On Solaris with BPF, Ethernet devices also offer
587 * DLT_IPNET, so we, if DLT_IPNET is defined, we don't
588 * treat it as an indication that the device isn't an
591 if (v == DLT_EN10MB) {
593 for (i = 0; i < bdlp->bfl_len; i++) {
594 if (bdlp->bfl_list[i] != DLT_EN10MB
596 && bdlp->bfl_list[i] != DLT_IPNET
605 * We reserved one more slot at the end of
608 bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS;
614 * EINVAL just means "we don't support this ioctl on
615 * this device"; don't treat it as an error.
617 if (errno != EINVAL) {
618 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
619 "BIOCGDLTLIST: %s", pcap_strerror(errno));
628 pcap_can_set_rfmon_bpf(pcap_t *p)
630 #if defined(__APPLE__)
631 struct utsname osinfo;
635 struct bpf_dltlist bdl;
639 * The joys of monitor mode on OS X.
641 * Prior to 10.4, it's not supported at all.
643 * In 10.4, if adapter enN supports monitor mode, there's a
644 * wltN adapter corresponding to it; you open it, instead of
645 * enN, to get monitor mode. You get whatever link-layer
646 * headers it supplies.
648 * In 10.5, and, we assume, later releases, if adapter enN
649 * supports monitor mode, it offers, among its selectable
650 * DLT_ values, values that let you get the 802.11 header;
651 * selecting one of those values puts the adapter into monitor
652 * mode (i.e., you can't get 802.11 headers except in monitor
653 * mode, and you can't get Ethernet headers in monitor mode).
655 if (uname(&osinfo) == -1) {
657 * Can't get the OS version; just say "no".
662 * We assume osinfo.sysname is "Darwin", because
663 * __APPLE__ is defined. We just check the version.
665 if (osinfo.release[0] < '8' && osinfo.release[1] == '.') {
667 * 10.3 (Darwin 7.x) or earlier.
668 * Monitor mode not supported.
672 if (osinfo.release[0] == '8' && osinfo.release[1] == '.') {
674 * 10.4 (Darwin 8.x). s/en/wlt/, and check
675 * whether the device exists.
677 if (strncmp(p->opt.source, "en", 2) != 0) {
679 * Not an enN device; no monitor mode.
683 fd = socket(AF_INET, SOCK_DGRAM, 0);
685 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
686 "socket: %s", pcap_strerror(errno));
689 strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name));
690 strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name));
691 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
704 * Everything else is 10.5 or later; for those,
705 * we just open the enN device, and check whether
706 * we have any 802.11 devices.
708 * First, open a BPF device.
712 return (fd); /* fd is the appropriate error code */
715 * Now bind to the device.
717 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name));
718 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
723 * There's no such device.
726 return (PCAP_ERROR_NO_SUCH_DEVICE);
730 * Return a "network down" indication, so that
731 * the application can report that rather than
732 * saying we had a mysterious failure and
733 * suggest that they report a problem to the
734 * libpcap developers.
737 return (PCAP_ERROR_IFACE_NOT_UP);
740 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
742 p->opt.source, pcap_strerror(errno));
749 * We know the default link type -- now determine all the DLTs
750 * this interface supports. If this fails with EINVAL, it's
751 * not fatal; we just don't get to use the feature later.
752 * (We don't care about DLT_DOCSIS, so we pass DLT_NULL
753 * as the default DLT for this adapter.)
755 if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) {
759 if (find_802_11(&bdl) != -1) {
761 * We have an 802.11 DLT, so we can set monitor mode.
768 #endif /* BIOCGDLTLIST */
770 #elif defined(HAVE_BSD_IEEE80211)
773 ret = monitor_mode(p, 0);
774 if (ret == PCAP_ERROR_RFMON_NOTSUP)
775 return (0); /* not an error, just a "can't do" */
777 return (1); /* success */
785 pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps)
790 * "ps_recv" counts packets handed to the filter, not packets
791 * that passed the filter. This includes packets later dropped
792 * because we ran out of buffer space.
794 * "ps_drop" counts packets dropped inside the BPF device
795 * because we ran out of buffer space. It doesn't count
796 * packets dropped by the interface driver. It counts
797 * only packets that passed the filter.
799 * Both statistics include packets not yet read from the kernel
800 * by libpcap, and thus not yet seen by the application.
802 if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) {
803 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s",
804 pcap_strerror(errno));
808 ps->ps_recv = s.bs_recv;
809 ps->ps_drop = s.bs_drop;
815 pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
819 register u_char *bp, *ep;
824 #ifdef HAVE_ZEROCOPY_BPF
830 * Has "pcap_breakloop()" been called?
834 * Yes - clear the flag that indicates that it
835 * has, and return PCAP_ERROR_BREAK to indicate
836 * that we were told to break out of the loop.
839 return (PCAP_ERROR_BREAK);
844 * When reading without zero-copy from a file descriptor, we
845 * use a single buffer and return a length of data in the
846 * buffer. With zero-copy, we update the p->buffer pointer
847 * to point at whatever underlying buffer contains the next
848 * data and update cc to reflect the data found in the
851 #ifdef HAVE_ZEROCOPY_BPF
852 if (p->md.zerocopy) {
853 if (p->buffer != NULL)
855 i = pcap_next_zbuf(p, &cc);
863 cc = read(p->fd, (char *)p->buffer, p->bufsize);
866 /* Don't choke when we get ptraced */
875 * Sigh. More AIX wonderfulness.
877 * For some unknown reason the uiomove()
878 * operation in the bpf kernel extension
879 * used to copy the buffer into user
880 * space sometimes returns EFAULT. I have
881 * no idea why this is the case given that
882 * a kernel debugger shows the user buffer
883 * is correct. This problem appears to
884 * be mostly mitigated by the memset of
885 * the buffer before it is first used.
886 * Very strange.... Shaun Clowes
888 * In any case this means that we shouldn't
889 * treat EFAULT as a fatal error; as we
890 * don't have an API for returning
891 * a "some packets were dropped since
892 * the last packet you saw" indication,
893 * we just ignore EFAULT and keep reading.
903 * The device on which we're capturing
906 * XXX - we should really return
907 * PCAP_ERROR_IFACE_NOT_UP, but
908 * pcap_dispatch() etc. aren't
909 * defined to retur that.
911 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
912 "The interface went down");
915 #if defined(sun) && !defined(BSD) && !defined(__svr4__) && !defined(__SVR4)
917 * Due to a SunOS bug, after 2^31 bytes, the kernel
918 * file offset overflows and read fails with EINVAL.
919 * The lseek() to 0 will fix things.
922 if (lseek(p->fd, 0L, SEEK_CUR) +
924 (void)lseek(p->fd, 0L, SEEK_SET);
930 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s",
931 pcap_strerror(errno));
939 * Loop through each packet.
941 #define bhp ((struct bpf_hdr *)bp)
947 register int caplen, hdrlen;
950 * Has "pcap_breakloop()" been called?
951 * If so, return immediately - if we haven't read any
952 * packets, clear the flag and return PCAP_ERROR_BREAK
953 * to indicate that we were told to break out of the loop,
954 * otherwise leave the flag set, so that the *next* call
955 * will break out of the loop without having read any
956 * packets, and return the number of packets we've
963 * ep is set based on the return value of read(),
964 * but read() from a BPF device doesn't necessarily
965 * return a value that's a multiple of the alignment
966 * value for BPF_WORDALIGN(). However, whenever we
967 * increment bp, we round up the increment value by
968 * a value rounded up by BPF_WORDALIGN(), so we
969 * could increment bp past ep after processing the
970 * last packet in the buffer.
972 * We treat ep < bp as an indication that this
973 * happened, and just set p->cc to 0.
979 return (PCAP_ERROR_BREAK);
984 caplen = bhp->bh_caplen;
985 hdrlen = bhp->bh_hdrlen;
988 * Short-circuit evaluation: if using BPF filter
989 * in kernel, no need to do it now - we already know
990 * the packet passed the filter.
993 * Note: the filter code was generated assuming
994 * that p->fddipad was the amount of padding
995 * before the header, as that's what's required
996 * in the kernel, so we run the filter before
997 * skipping that padding.
1000 if (p->md.use_bpf ||
1001 bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) {
1002 struct pcap_pkthdr pkthdr;
1004 pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec;
1007 * AIX's BPF returns seconds/nanoseconds time
1008 * stamps, not seconds/microseconds time stamps.
1010 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000;
1012 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec;
1016 pkthdr.caplen = caplen - pad;
1019 if (bhp->bh_datalen > pad)
1020 pkthdr.len = bhp->bh_datalen - pad;
1025 pkthdr.caplen = caplen;
1026 pkthdr.len = bhp->bh_datalen;
1028 (*callback)(user, &pkthdr, datap);
1029 bp += BPF_WORDALIGN(caplen + hdrlen);
1030 if (++n >= cnt && cnt > 0) {
1034 * See comment above about p->cc < 0.
1044 bp += BPF_WORDALIGN(caplen + hdrlen);
1053 pcap_inject_bpf(pcap_t *p, const void *buf, size_t size)
1057 ret = write(p->fd, buf, size);
1059 if (ret == -1 && errno == EAFNOSUPPORT) {
1061 * In Mac OS X, there's a bug wherein setting the
1062 * BIOCSHDRCMPLT flag causes writes to fail; see,
1065 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch
1067 * So, if, on OS X, we get EAFNOSUPPORT from the write, we
1068 * assume it's due to that bug, and turn off that flag
1069 * and try again. If we succeed, it either means that
1070 * somebody applied the fix from that URL, or other patches
1073 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/
1075 * and are running a Darwin kernel with those fixes, or
1076 * that Apple fixed the problem in some OS X release.
1078 u_int spoof_eth_src = 0;
1080 if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
1081 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1082 "send: can't turn off BIOCSHDRCMPLT: %s",
1083 pcap_strerror(errno));
1084 return (PCAP_ERROR);
1088 * Now try the write again.
1090 ret = write(p->fd, buf, size);
1092 #endif /* __APPLE__ */
1094 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
1095 pcap_strerror(errno));
1096 return (PCAP_ERROR);
1103 bpf_odminit(char *errbuf)
1107 if (odm_initialize() == -1) {
1108 if (odm_err_msg(odmerrno, &errstr) == -1)
1109 errstr = "Unknown error";
1110 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1111 "bpf_load: odm_initialize failed: %s",
1113 return (PCAP_ERROR);
1116 if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) {
1117 if (odm_err_msg(odmerrno, &errstr) == -1)
1118 errstr = "Unknown error";
1119 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1120 "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s",
1122 (void)odm_terminate();
1123 return (PCAP_ERROR);
1130 bpf_odmcleanup(char *errbuf)
1134 if (odm_unlock(odmlockid) == -1) {
1135 if (errbuf != NULL) {
1136 if (odm_err_msg(odmerrno, &errstr) == -1)
1137 errstr = "Unknown error";
1138 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1139 "bpf_load: odm_unlock failed: %s",
1142 return (PCAP_ERROR);
1145 if (odm_terminate() == -1) {
1146 if (errbuf != NULL) {
1147 if (odm_err_msg(odmerrno, &errstr) == -1)
1148 errstr = "Unknown error";
1149 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1150 "bpf_load: odm_terminate failed: %s",
1153 return (PCAP_ERROR);
1160 bpf_load(char *errbuf)
1164 int numminors, i, rc;
1167 struct bpf_config cfg_bpf;
1168 struct cfg_load cfg_ld;
1169 struct cfg_kmod cfg_km;
1172 * This is very very close to what happens in the real implementation
1173 * but I've fixed some (unlikely) bug situations.
1178 if (bpf_odminit(errbuf) == PCAP_ERROR)
1179 return (PCAP_ERROR);
1181 major = genmajor(BPF_NAME);
1183 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1184 "bpf_load: genmajor failed: %s", pcap_strerror(errno));
1185 (void)bpf_odmcleanup(NULL);
1186 return (PCAP_ERROR);
1189 minors = getminor(major, &numminors, BPF_NAME);
1191 minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1);
1193 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1194 "bpf_load: genminor failed: %s",
1195 pcap_strerror(errno));
1196 (void)bpf_odmcleanup(NULL);
1197 return (PCAP_ERROR);
1201 if (bpf_odmcleanup(errbuf) == PCAP_ERROR)
1202 return (PCAP_ERROR);
1204 rc = stat(BPF_NODE "0", &sbuf);
1205 if (rc == -1 && errno != ENOENT) {
1206 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1207 "bpf_load: can't stat %s: %s",
1208 BPF_NODE "0", pcap_strerror(errno));
1209 return (PCAP_ERROR);
1212 if (rc == -1 || getmajor(sbuf.st_rdev) != major) {
1213 for (i = 0; i < BPF_MINORS; i++) {
1214 sprintf(buf, "%s%d", BPF_NODE, i);
1216 if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) {
1217 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1218 "bpf_load: can't mknod %s: %s",
1219 buf, pcap_strerror(errno));
1220 return (PCAP_ERROR);
1225 /* Check if the driver is loaded */
1226 memset(&cfg_ld, 0x0, sizeof(cfg_ld));
1228 sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME);
1229 if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) ||
1230 (cfg_ld.kmid == 0)) {
1231 /* Driver isn't loaded, load it now */
1232 if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) {
1233 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1234 "bpf_load: could not load driver: %s",
1236 return (PCAP_ERROR);
1240 /* Configure the driver */
1241 cfg_km.cmd = CFG_INIT;
1242 cfg_km.kmid = cfg_ld.kmid;
1243 cfg_km.mdilen = sizeof(cfg_bpf);
1244 cfg_km.mdiptr = (void *)&cfg_bpf;
1245 for (i = 0; i < BPF_MINORS; i++) {
1246 cfg_bpf.devno = domakedev(major, i);
1247 if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) {
1248 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1249 "bpf_load: could not configure driver: %s",
1251 return (PCAP_ERROR);
1262 * Turn off rfmon mode if necessary.
1265 pcap_cleanup_bpf(pcap_t *p)
1267 #ifdef HAVE_BSD_IEEE80211
1269 struct ifmediareq req;
1273 if (p->md.must_do_on_close != 0) {
1275 * There's something we have to do when closing this
1278 #ifdef HAVE_BSD_IEEE80211
1279 if (p->md.must_do_on_close & MUST_CLEAR_RFMON) {
1281 * We put the interface into rfmon mode;
1282 * take it out of rfmon mode.
1284 * XXX - if somebody else wants it in rfmon
1285 * mode, this code cannot know that, so it'll take
1286 * it out of rfmon mode.
1288 sock = socket(AF_INET, SOCK_DGRAM, 0);
1291 "Can't restore interface flags (socket() failed: %s).\n"
1292 "Please adjust manually.\n",
1295 memset(&req, 0, sizeof(req));
1296 strncpy(req.ifm_name, p->md.device,
1297 sizeof(req.ifm_name));
1298 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
1300 "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n"
1301 "Please adjust manually.\n",
1304 if (req.ifm_current & IFM_IEEE80211_MONITOR) {
1306 * Rfmon mode is currently on;
1309 memset(&ifr, 0, sizeof(ifr));
1310 (void)strncpy(ifr.ifr_name,
1312 sizeof(ifr.ifr_name));
1314 req.ifm_current & ~IFM_IEEE80211_MONITOR;
1315 if (ioctl(sock, SIOCSIFMEDIA,
1318 "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n"
1319 "Please adjust manually.\n",
1327 #endif /* HAVE_BSD_IEEE80211 */
1330 * Take this pcap out of the list of pcaps for which we
1331 * have to take the interface out of some mode.
1333 pcap_remove_from_pcaps_to_close(p);
1334 p->md.must_do_on_close = 0;
1337 #ifdef HAVE_ZEROCOPY_BPF
1338 if (p->md.zerocopy) {
1340 * Delete the mappings. Note that p->buffer gets
1341 * initialized to one of the mmapped regions in
1342 * this case, so do not try and free it directly;
1343 * null it out so that pcap_cleanup_live_common()
1344 * doesn't try to free it.
1346 if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL)
1347 (void) munmap(p->md.zbuf1, p->md.zbufsize);
1348 if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL)
1349 (void) munmap(p->md.zbuf2, p->md.zbufsize);
1354 if (p->md.device != NULL) {
1356 p->md.device = NULL;
1358 pcap_cleanup_live_common(p);
1362 check_setif_failure(pcap_t *p, int error)
1370 if (error == ENXIO) {
1372 * No such device exists.
1375 if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) {
1377 * Monitor mode was requested, and we're trying
1378 * to open a "wltN" device. Assume that this
1379 * is 10.4 and that we were asked to open an
1380 * "enN" device; if that device exists, return
1381 * "monitor mode not supported on the device".
1383 fd = socket(AF_INET, SOCK_DGRAM, 0);
1385 strlcpy(ifr.ifr_name, "en",
1386 sizeof(ifr.ifr_name));
1387 strlcat(ifr.ifr_name, p->opt.source + 3,
1388 sizeof(ifr.ifr_name));
1389 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
1391 * We assume this failed because
1392 * the underlying device doesn't
1395 err = PCAP_ERROR_NO_SUCH_DEVICE;
1396 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1397 "SIOCGIFFLAGS on %s failed: %s",
1398 ifr.ifr_name, pcap_strerror(errno));
1401 * The underlying "enN" device
1402 * exists, but there's no
1403 * corresponding "wltN" device;
1404 * that means that the "enN"
1405 * device doesn't support
1406 * monitor mode, probably because
1407 * it's an Ethernet device rather
1408 * than a wireless device.
1410 err = PCAP_ERROR_RFMON_NOTSUP;
1415 * We can't find out whether there's
1416 * an underlying "enN" device, so
1417 * just report "no such device".
1419 err = PCAP_ERROR_NO_SUCH_DEVICE;
1420 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1421 "socket() failed: %s",
1422 pcap_strerror(errno));
1430 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF failed: %s",
1431 pcap_strerror(errno));
1432 return (PCAP_ERROR_NO_SUCH_DEVICE);
1433 } else if (errno == ENETDOWN) {
1435 * Return a "network down" indication, so that
1436 * the application can report that rather than
1437 * saying we had a mysterious failure and
1438 * suggest that they report a problem to the
1439 * libpcap developers.
1441 return (PCAP_ERROR_IFACE_NOT_UP);
1444 * Some other error; fill in the error string, and
1445 * return PCAP_ERROR.
1447 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s",
1448 p->opt.source, pcap_strerror(errno));
1449 return (PCAP_ERROR);
1454 * Default capture buffer size.
1455 * 32K isn't very much for modern machines with fast networks; we
1456 * pick .5M, as that's the maximum on at least some systems with BPF.
1458 #define DEFAULT_BUFSIZE 524288
1461 pcap_activate_bpf(pcap_t *p)
1467 char *ifrname = ifr.lifr_name;
1468 const size_t ifnamsiz = sizeof(ifr.lifr_name);
1471 char *ifrname = ifr.ifr_name;
1472 const size_t ifnamsiz = sizeof(ifr.ifr_name);
1474 struct bpf_version bv;
1477 char *wltdev = NULL;
1480 struct bpf_dltlist bdl;
1481 #if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)
1484 #endif /* BIOCGDLTLIST */
1485 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
1486 u_int spoof_eth_src = 1;
1489 struct bpf_insn total_insn;
1490 struct bpf_program total_prog;
1491 struct utsname osinfo;
1494 if (strstr(device, "dag")) {
1495 return dag_open_live(device, snaplen, promisc, to_ms, ebuf);
1497 #endif /* HAVE_DAG_API */
1500 memset(&bdl, 0, sizeof(bdl));
1501 int have_osinfo = 0;
1502 #ifdef HAVE_ZEROCOPY_BPF
1504 u_int bufmode, zbufmax;
1515 if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) {
1516 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s",
1517 pcap_strerror(errno));
1518 status = PCAP_ERROR;
1521 if (bv.bv_major != BPF_MAJOR_VERSION ||
1522 bv.bv_minor < BPF_MINOR_VERSION) {
1523 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1524 "kernel bpf filter out of date");
1525 status = PCAP_ERROR;
1529 p->md.device = strdup(p->opt.source);
1530 if (p->md.device == NULL) {
1531 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s",
1532 pcap_strerror(errno));
1533 status = PCAP_ERROR;
1538 * Try finding a good size for the buffer; 32768 may be too
1539 * big, so keep cutting it in half until we find a size
1540 * that works, or run out of sizes to try. If the default
1541 * is larger, don't make it smaller.
1543 * XXX - there should be a user-accessible hook to set the
1544 * initial buffer size.
1545 * Attempt to find out the version of the OS on which we're running.
1547 if (uname(&osinfo) == 0)
1552 * See comment in pcap_can_set_rfmon_bpf() for an explanation
1553 * of why we check the version number.
1558 * We assume osinfo.sysname is "Darwin", because
1559 * __APPLE__ is defined. We just check the version.
1561 if (osinfo.release[0] < '8' &&
1562 osinfo.release[1] == '.') {
1564 * 10.3 (Darwin 7.x) or earlier.
1566 status = PCAP_ERROR_RFMON_NOTSUP;
1569 if (osinfo.release[0] == '8' &&
1570 osinfo.release[1] == '.') {
1572 * 10.4 (Darwin 8.x). s/en/wlt/
1574 if (strncmp(p->opt.source, "en", 2) != 0) {
1576 * Not an enN device; check
1577 * whether the device even exists.
1579 sockfd = socket(AF_INET, SOCK_DGRAM, 0);
1582 p->opt.source, ifnamsiz);
1583 if (ioctl(sockfd, SIOCGIFFLAGS,
1584 (char *)&ifr) < 0) {
1592 status = PCAP_ERROR_NO_SUCH_DEVICE;
1595 "SIOCGIFFLAGS failed: %s",
1596 pcap_strerror(errno));
1598 status = PCAP_ERROR_RFMON_NOTSUP;
1602 * We can't find out whether
1603 * the device exists, so just
1604 * report "no such device".
1606 status = PCAP_ERROR_NO_SUCH_DEVICE;
1609 "socket() failed: %s",
1610 pcap_strerror(errno));
1614 wltdev = malloc(strlen(p->opt.source) + 2);
1615 if (wltdev == NULL) {
1616 (void)snprintf(p->errbuf,
1617 PCAP_ERRBUF_SIZE, "malloc: %s",
1618 pcap_strerror(errno));
1619 status = PCAP_ERROR;
1622 strcpy(wltdev, "wlt");
1623 strcat(wltdev, p->opt.source + 2);
1624 free(p->opt.source);
1625 p->opt.source = wltdev;
1628 * Everything else is 10.5 or later; for those,
1629 * we just open the enN device, and set the DLT.
1633 #endif /* __APPLE__ */
1634 #ifdef HAVE_ZEROCOPY_BPF
1636 * If the BPF extension to set buffer mode is present, try setting
1637 * the mode to zero-copy. If that fails, use regular buffering. If
1638 * it succeeds but other setup fails, return an error to the user.
1640 bufmode = BPF_BUFMODE_ZBUF;
1641 if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) {
1643 * We have zerocopy BPF; use it.
1648 * How to pick a buffer size: first, query the maximum buffer
1649 * size supported by zero-copy. This also lets us quickly
1650 * determine whether the kernel generally supports zero-copy.
1651 * Then, if a buffer size was specified, use that, otherwise
1652 * query the default buffer size, which reflects kernel
1653 * policy for a desired default. Round to the nearest page
1656 if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) {
1657 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s",
1658 pcap_strerror(errno));
1662 if (p->opt.buffer_size != 0) {
1664 * A buffer size was explicitly specified; use it.
1666 v = p->opt.buffer_size;
1668 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) ||
1669 v < DEFAULT_BUFSIZE)
1670 v = DEFAULT_BUFSIZE;
1673 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
1675 p->md.zbufsize = roundup(v, getpagesize());
1676 if (p->md.zbufsize > zbufmax)
1677 p->md.zbufsize = zbufmax;
1678 p->md.zbuf1 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE,
1680 p->md.zbuf2 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE,
1682 if (p->md.zbuf1 == MAP_FAILED || p->md.zbuf2 == MAP_FAILED) {
1683 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s",
1684 pcap_strerror(errno));
1687 bzero(&bz, sizeof(bz));
1688 bz.bz_bufa = p->md.zbuf1;
1689 bz.bz_bufb = p->md.zbuf2;
1690 bz.bz_buflen = p->md.zbufsize;
1691 if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) {
1692 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s",
1693 pcap_strerror(errno));
1696 (void)strncpy(ifrname, p->opt.source, ifnamsiz);
1697 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
1698 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s",
1699 p->opt.source, pcap_strerror(errno));
1702 v = p->md.zbufsize - sizeof(struct bpf_zbuf_header);
1707 * We don't have zerocopy BPF.
1708 * Set the buffer size.
1710 if (p->opt.buffer_size != 0) {
1712 * A buffer size was explicitly specified; use it.
1714 if (ioctl(fd, BIOCSBLEN,
1715 (caddr_t)&p->opt.buffer_size) < 0) {
1716 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1717 "BIOCSBLEN: %s: %s", p->opt.source,
1718 pcap_strerror(errno));
1719 status = PCAP_ERROR;
1724 * Now bind to the device.
1726 (void)strncpy(ifrname, p->opt.source, ifnamsiz);
1728 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) < 0)
1730 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0)
1733 status = check_setif_failure(p, errno);
1738 * No buffer size was explicitly specified.
1740 * Try finding a good size for the buffer;
1741 * DEFAULT_BUFSIZE may be too big, so keep
1742 * cutting it in half until we find a size
1743 * that works, or run out of sizes to try.
1744 * If the default is larger, don't make it smaller.
1746 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) ||
1747 v < DEFAULT_BUFSIZE)
1748 v = DEFAULT_BUFSIZE;
1749 for ( ; v != 0; v >>= 1) {
1751 * Ignore the return value - this is because the
1752 * call fails on BPF systems that don't have
1753 * kernel malloc. And if the call fails, it's
1754 * no big deal, we just continue to use the
1755 * standard buffer size.
1757 (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v);
1759 (void)strncpy(ifrname, p->opt.source, ifnamsiz);
1761 if (ioctl(fd, BIOCSETLIF, (caddr_t)&ifr) >= 0)
1763 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0)
1765 break; /* that size worked; we're done */
1767 if (errno != ENOBUFS) {
1768 status = check_setif_failure(p, errno);
1774 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1775 "BIOCSBLEN: %s: No buffer size worked",
1777 status = PCAP_ERROR;
1784 /* Get the data link layer type. */
1785 if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) {
1786 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s",
1787 pcap_strerror(errno));
1788 status = PCAP_ERROR;
1794 * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT.
1817 * We don't know what to map this to yet.
1819 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u",
1821 status = PCAP_ERROR;
1825 #if _BSDI_VERSION - 0 >= 199510
1826 /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */
1841 case 12: /*DLT_C_HDLC*/
1849 * We know the default link type -- now determine all the DLTs
1850 * this interface supports. If this fails with EINVAL, it's
1851 * not fatal; we just don't get to use the feature later.
1853 if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) {
1854 status = PCAP_ERROR;
1857 p->dlt_count = bdl.bfl_len;
1858 p->dlt_list = bdl.bfl_list;
1862 * Monitor mode fun, continued.
1864 * For 10.5 and, we're assuming, later releases, as noted above,
1865 * 802.1 adapters that support monitor mode offer both DLT_EN10MB,
1866 * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information
1867 * DLT_ value. Choosing one of the 802.11 DLT_ values will turn
1870 * Therefore, if the user asked for monitor mode, we filter out
1871 * the DLT_EN10MB value, as you can't get that in monitor mode,
1872 * and, if the user didn't ask for monitor mode, we filter out
1873 * the 802.11 DLT_ values, because selecting those will turn
1874 * monitor mode on. Then, for monitor mode, if an 802.11-plus-
1875 * radio DLT_ value is offered, we try to select that, otherwise
1876 * we try to select DLT_IEEE802_11.
1879 if (isdigit((unsigned)osinfo.release[0]) &&
1880 (osinfo.release[0] == '9' ||
1881 isdigit((unsigned)osinfo.release[1]))) {
1883 * 10.5 (Darwin 9.x), or later.
1885 new_dlt = find_802_11(&bdl);
1886 if (new_dlt != -1) {
1888 * We have at least one 802.11 DLT_ value,
1889 * so this is an 802.11 interface.
1890 * new_dlt is the best of the 802.11
1891 * DLT_ values in the list.
1895 * Our caller wants monitor mode.
1896 * Purge DLT_EN10MB from the list
1897 * of link-layer types, as selecting
1898 * it will keep monitor mode off.
1903 * If the new mode we want isn't
1904 * the default mode, attempt to
1905 * select the new mode.
1908 if (ioctl(p->fd, BIOCSDLT,
1920 * Our caller doesn't want
1921 * monitor mode. Unless this
1922 * is being done by pcap_open_live(),
1923 * purge the 802.11 link-layer types
1924 * from the list, as selecting
1925 * one of them will turn monitor
1934 * The caller requested monitor
1935 * mode, but we have no 802.11
1936 * link-layer types, so they
1939 status = PCAP_ERROR_RFMON_NOTSUP;
1945 #elif defined(HAVE_BSD_IEEE80211)
1947 * *BSD with the new 802.11 ioctls.
1948 * Do we want monitor mode?
1952 * Try to put the interface into monitor mode.
1954 status = monitor_mode(p, 1);
1963 * We're in monitor mode.
1964 * Try to find the best 802.11 DLT_ value and, if we
1965 * succeed, try to switch to that mode if we're not
1966 * already in that mode.
1968 new_dlt = find_802_11(&bdl);
1969 if (new_dlt != -1) {
1971 * We have at least one 802.11 DLT_ value.
1972 * new_dlt is the best of the 802.11
1973 * DLT_ values in the list.
1975 * If the new mode we want isn't the default mode,
1976 * attempt to select the new mode.
1979 if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) {
1981 * We succeeded; make this the
1989 #endif /* various platforms */
1990 #endif /* BIOCGDLTLIST */
1993 * If this is an Ethernet device, and we don't have a DLT_ list,
1994 * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give
1995 * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to
1996 * do, but there's not much we can do about that without finding
1997 * some other way of determining whether it's an Ethernet or 802.11
2000 if (v == DLT_EN10MB && p->dlt_count == 0) {
2001 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
2003 * If that fails, just leave the list empty.
2005 if (p->dlt_list != NULL) {
2006 p->dlt_list[0] = DLT_EN10MB;
2007 p->dlt_list[1] = DLT_DOCSIS;
2013 p->fddipad = PCAP_FDDIPAD;
2019 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
2021 * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so
2022 * the link-layer source address isn't forcibly overwritten.
2023 * (Should we ignore errors? Should we do this only if
2024 * we're open for writing?)
2026 * XXX - I seem to remember some packet-sending bug in some
2027 * BSDs - check CVS log for "bpf.c"?
2029 if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
2030 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2031 "BIOCSHDRCMPLT: %s", pcap_strerror(errno));
2032 status = PCAP_ERROR;
2037 #ifdef HAVE_ZEROCOPY_BPF
2038 if (p->md.timeout != 0 && !p->md.zerocopy) {
2040 if (p->md.timeout) {
2043 * XXX - is this seconds/nanoseconds in AIX?
2044 * (Treating it as such doesn't fix the timeout
2045 * problem described below.)
2047 * XXX - Mac OS X 10.6 mishandles BIOCSRTIMEOUT in
2048 * 64-bit userland - it takes, as an argument, a
2049 * "struct BPF_TIMEVAL", which has 32-bit tv_sec
2050 * and tv_usec, rather than a "struct timeval".
2052 * If this platform defines "struct BPF_TIMEVAL",
2053 * we check whether the structure size in BIOCSRTIMEOUT
2054 * is that of a "struct timeval" and, if not, we use
2055 * a "struct BPF_TIMEVAL" rather than a "struct timeval".
2056 * (That way, if the bug is fixed in a future release,
2057 * we will still do the right thing.)
2060 #ifdef HAVE_STRUCT_BPF_TIMEVAL
2061 struct BPF_TIMEVAL bpf_to;
2063 if (IOCPARM_LEN(BIOCSRTIMEOUT) != sizeof(struct timeval)) {
2064 bpf_to.tv_sec = p->md.timeout / 1000;
2065 bpf_to.tv_usec = (p->md.timeout * 1000) % 1000000;
2066 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&bpf_to) < 0) {
2067 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2068 "BIOCSRTIMEOUT: %s", pcap_strerror(errno));
2069 status = PCAP_ERROR;
2074 to.tv_sec = p->md.timeout / 1000;
2075 to.tv_usec = (p->md.timeout * 1000) % 1000000;
2076 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) {
2077 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2078 "BIOCSRTIMEOUT: %s", pcap_strerror(errno));
2079 status = PCAP_ERROR;
2082 #ifdef HAVE_STRUCT_BPF_TIMEVAL
2088 #ifdef BIOCIMMEDIATE
2090 * Darren Reed notes that
2092 * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the
2093 * timeout appears to be ignored and it waits until the buffer
2094 * is filled before returning. The result of not having it
2095 * set is almost worse than useless if your BPF filter
2096 * is reducing things to only a few packets (i.e. one every
2099 * so we turn BIOCIMMEDIATE mode on if this is AIX.
2101 * We don't turn it on for other platforms, as that means we
2102 * get woken up for every packet, which may not be what we want;
2103 * in the Winter 1993 USENIX paper on BPF, they say:
2105 * Since a process might want to look at every packet on a
2106 * network and the time between packets can be only a few
2107 * microseconds, it is not possible to do a read system call
2108 * per packet and BPF must collect the data from several
2109 * packets and return it as a unit when the monitoring
2110 * application does a read.
2112 * which I infer is the reason for the timeout - it means we
2113 * wait that amount of time, in the hopes that more packets
2114 * will arrive and we'll get them all with one read.
2116 * Setting BIOCIMMEDIATE mode on FreeBSD (and probably other
2117 * BSDs) causes the timeout to be ignored.
2119 * On the other hand, some platforms (e.g., Linux) don't support
2120 * timeouts, they just hand stuff to you as soon as it arrives;
2121 * if that doesn't cause a problem on those platforms, it may
2122 * be OK to have BIOCIMMEDIATE mode on BSD as well.
2124 * (Note, though, that applications may depend on the read
2125 * completing, even if no packets have arrived, when the timeout
2126 * expires, e.g. GUI applications that have to check for input
2127 * while waiting for packets to arrive; a non-zero timeout
2128 * prevents "select()" from working right on FreeBSD and
2129 * possibly other BSDs, as the timer doesn't start until a
2130 * "read()" is done, so the timer isn't in effect if the
2131 * application is blocked on a "select()", and the "select()"
2132 * doesn't get woken up for a BPF device until the buffer
2136 if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) {
2137 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s",
2138 pcap_strerror(errno));
2139 status = PCAP_ERROR;
2142 #endif /* BIOCIMMEDIATE */
2145 if (p->opt.promisc) {
2146 /* set promiscuous mode, just warn if it fails */
2147 if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) {
2148 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s",
2149 pcap_strerror(errno));
2150 status = PCAP_WARNING_PROMISC_NOTSUP;
2154 if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) {
2155 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s",
2156 pcap_strerror(errno));
2157 status = PCAP_ERROR;
2161 #ifdef HAVE_ZEROCOPY_BPF
2162 if (!p->md.zerocopy) {
2164 p->buffer = (u_char *)malloc(p->bufsize);
2165 if (p->buffer == NULL) {
2166 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s",
2167 pcap_strerror(errno));
2168 status = PCAP_ERROR;
2172 /* For some strange reason this seems to prevent the EFAULT
2173 * problems we have experienced from AIX BPF. */
2174 memset(p->buffer, 0x0, p->bufsize);
2176 #ifdef HAVE_ZEROCOPY_BPF
2181 * If there's no filter program installed, there's
2182 * no indication to the kernel of what the snapshot
2183 * length should be, so no snapshotting is done.
2185 * Therefore, when we open the device, we install
2186 * an "accept everything" filter with the specified
2189 total_insn.code = (u_short)(BPF_RET | BPF_K);
2192 total_insn.k = p->snapshot;
2194 total_prog.bf_len = 1;
2195 total_prog.bf_insns = &total_insn;
2196 if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) {
2197 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
2198 pcap_strerror(errno));
2199 status = PCAP_ERROR;
2204 * On most BPF platforms, either you can do a "select()" or
2205 * "poll()" on a BPF file descriptor and it works correctly,
2206 * or you can do it and it will return "readable" if the
2207 * hold buffer is full but not if the timeout expires *and*
2208 * a non-blocking read will, if the hold buffer is empty
2209 * but the store buffer isn't empty, rotate the buffers
2210 * and return what packets are available.
2212 * In the latter case, the fact that a non-blocking read
2213 * will give you the available packets means you can work
2214 * around the failure of "select()" and "poll()" to wake up
2215 * and return "readable" when the timeout expires by using
2216 * the timeout as the "select()" or "poll()" timeout, putting
2217 * the BPF descriptor into non-blocking mode, and read from
2218 * it regardless of whether "select()" reports it as readable
2221 * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()"
2222 * won't wake up and return "readable" if the timer expires
2223 * and non-blocking reads return EWOULDBLOCK if the hold
2224 * buffer is empty, even if the store buffer is non-empty.
2226 * This means the workaround in question won't work.
2228 * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd"
2229 * to -1, which means "sorry, you can't use 'select()' or 'poll()'
2230 * here". On all other BPF platforms, we set it to the FD for
2231 * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking
2232 * read will, if the hold buffer is empty and the store buffer
2233 * isn't empty, rotate the buffers and return what packets are
2234 * there (and in sufficiently recent versions of OpenBSD
2235 * "select()" and "poll()" should work correctly).
2237 * XXX - what about AIX?
2239 p->selectable_fd = p->fd; /* assume select() works until we know otherwise */
2242 * We can check what OS this is.
2244 if (strcmp(osinfo.sysname, "FreeBSD") == 0) {
2245 if (strncmp(osinfo.release, "4.3-", 4) == 0 ||
2246 strncmp(osinfo.release, "4.4-", 4) == 0)
2247 p->selectable_fd = -1;
2251 p->read_op = pcap_read_bpf;
2252 p->inject_op = pcap_inject_bpf;
2253 p->setfilter_op = pcap_setfilter_bpf;
2254 p->setdirection_op = pcap_setdirection_bpf;
2255 p->set_datalink_op = pcap_set_datalink_bpf;
2256 p->getnonblock_op = pcap_getnonblock_bpf;
2257 p->setnonblock_op = pcap_setnonblock_bpf;
2258 p->stats_op = pcap_stats_bpf;
2259 p->cleanup_op = pcap_cleanup_bpf;
2263 pcap_cleanup_bpf(p);
2268 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
2271 if (dag_platform_finddevs(alldevsp, errbuf) < 0)
2273 #endif /* HAVE_DAG_API */
2275 if (snf_platform_finddevs(alldevsp, errbuf) < 0)
2277 #endif /* HAVE_SNF_API */
2282 #ifdef HAVE_BSD_IEEE80211
2284 monitor_mode(pcap_t *p, int set)
2287 struct ifmediareq req;
2293 sock = socket(AF_INET, SOCK_DGRAM, 0);
2295 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s",
2296 pcap_strerror(errno));
2297 return (PCAP_ERROR);
2300 memset(&req, 0, sizeof req);
2301 strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name);
2304 * Find out how many media types we have.
2306 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
2308 * Can't get the media types.
2314 * There's no such device.
2317 return (PCAP_ERROR_NO_SUCH_DEVICE);
2321 * Interface doesn't support SIOC{G,S}IFMEDIA.
2324 return (PCAP_ERROR_RFMON_NOTSUP);
2327 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2328 "SIOCGIFMEDIA 1: %s", pcap_strerror(errno));
2330 return (PCAP_ERROR);
2333 if (req.ifm_count == 0) {
2338 return (PCAP_ERROR_RFMON_NOTSUP);
2342 * Allocate a buffer to hold all the media types, and
2343 * get the media types.
2345 media_list = malloc(req.ifm_count * sizeof(int));
2346 if (media_list == NULL) {
2347 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s",
2348 pcap_strerror(errno));
2350 return (PCAP_ERROR);
2352 req.ifm_ulist = media_list;
2353 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
2354 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s",
2355 pcap_strerror(errno));
2358 return (PCAP_ERROR);
2362 * Look for an 802.11 "automatic" media type.
2363 * We assume that all 802.11 adapters have that media type,
2364 * and that it will carry the monitor mode supported flag.
2367 for (i = 0; i < req.ifm_count; i++) {
2368 if (IFM_TYPE(media_list[i]) == IFM_IEEE80211
2369 && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) {
2370 /* OK, does it do monitor mode? */
2371 if (media_list[i] & IFM_IEEE80211_MONITOR) {
2380 * This adapter doesn't support monitor mode.
2383 return (PCAP_ERROR_RFMON_NOTSUP);
2388 * Don't just check whether we can enable monitor mode,
2389 * do so, if it's not already enabled.
2391 if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) {
2393 * Monitor mode isn't currently on, so turn it on,
2394 * and remember that we should turn it off when the
2399 * If we haven't already done so, arrange to have
2400 * "pcap_close_all()" called when we exit.
2402 if (!pcap_do_addexit(p)) {
2404 * "atexit()" failed; don't put the interface
2405 * in monitor mode, just give up.
2407 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2410 return (PCAP_ERROR);
2412 memset(&ifr, 0, sizeof(ifr));
2413 (void)strncpy(ifr.ifr_name, p->opt.source,
2414 sizeof(ifr.ifr_name));
2415 ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR;
2416 if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) {
2417 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2418 "SIOCSIFMEDIA: %s", pcap_strerror(errno));
2420 return (PCAP_ERROR);
2423 p->md.must_do_on_close |= MUST_CLEAR_RFMON;
2426 * Add this to the list of pcaps to close when we exit.
2428 pcap_add_to_pcaps_to_close(p);
2433 #endif /* HAVE_BSD_IEEE80211 */
2435 #if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211))
2437 * Check whether we have any 802.11 link-layer types; return the best
2438 * of the 802.11 link-layer types if we find one, and return -1
2441 * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the
2442 * best 802.11 link-layer type; any of the other 802.11-plus-radio
2443 * headers are second-best; 802.11 with no radio information is
2447 find_802_11(struct bpf_dltlist *bdlp)
2453 * Scan the list of DLT_ values, looking for 802.11 values,
2454 * and, if we find any, choose the best of them.
2457 for (i = 0; i < bdlp->bfl_len; i++) {
2458 switch (bdlp->bfl_list[i]) {
2460 case DLT_IEEE802_11:
2462 * 802.11, but no radio.
2464 * Offer this, and select it as the new mode
2465 * unless we've already found an 802.11
2466 * header with radio information.
2469 new_dlt = bdlp->bfl_list[i];
2472 case DLT_PRISM_HEADER:
2473 case DLT_AIRONET_HEADER:
2474 case DLT_IEEE802_11_RADIO_AVS:
2476 * 802.11 with radio, but not radiotap.
2478 * Offer this, and select it as the new mode
2479 * unless we've already found the radiotap DLT_.
2481 if (new_dlt != DLT_IEEE802_11_RADIO)
2482 new_dlt = bdlp->bfl_list[i];
2485 case DLT_IEEE802_11_RADIO:
2487 * 802.11 with radiotap.
2489 * Offer this, and select it as the new mode.
2491 new_dlt = bdlp->bfl_list[i];
2504 #endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */
2506 #if defined(__APPLE__) && defined(BIOCGDLTLIST)
2508 * Remove DLT_EN10MB from the list of DLT_ values, as we're in monitor mode,
2509 * and DLT_EN10MB isn't supported in monitor mode.
2512 remove_en(pcap_t *p)
2517 * Scan the list of DLT_ values and discard DLT_EN10MB.
2520 for (i = 0; i < p->dlt_count; i++) {
2521 switch (p->dlt_list[i]) {
2525 * Don't offer this one.
2531 * Just copy this mode over.
2537 * Copy this DLT_ value to its new position.
2539 p->dlt_list[j] = p->dlt_list[i];
2544 * Set the DLT_ count to the number of entries we copied.
2550 * Remove 802.11 link-layer types from the list of DLT_ values, as
2551 * we're not in monitor mode, and those DLT_ values will switch us
2555 remove_802_11(pcap_t *p)
2560 * Scan the list of DLT_ values and discard 802.11 values.
2563 for (i = 0; i < p->dlt_count; i++) {
2564 switch (p->dlt_list[i]) {
2566 case DLT_IEEE802_11:
2567 case DLT_PRISM_HEADER:
2568 case DLT_AIRONET_HEADER:
2569 case DLT_IEEE802_11_RADIO:
2570 case DLT_IEEE802_11_RADIO_AVS:
2572 * 802.11. Don't offer this one.
2578 * Just copy this mode over.
2584 * Copy this DLT_ value to its new position.
2586 p->dlt_list[j] = p->dlt_list[i];
2591 * Set the DLT_ count to the number of entries we copied.
2595 #endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */
2598 pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp)
2601 * Free any user-mode filter we might happen to have installed.
2603 pcap_freecode(&p->fcode);
2606 * Try to install the kernel filter.
2608 if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) {
2612 p->md.use_bpf = 1; /* filtering in the kernel */
2615 * Discard any previously-received packets, as they might
2616 * have passed whatever filter was formerly in effect, but
2617 * might not pass this filter (BIOCSETF discards packets
2618 * buffered in the kernel, so you can lose packets in any
2628 * If it failed with EINVAL, that's probably because the program
2629 * is invalid or too big. Validate it ourselves; if we like it
2630 * (we currently allow backward branches, to support protochain),
2631 * run it in userland. (There's no notion of "too big" for
2634 * Otherwise, just give up.
2635 * XXX - if the copy of the program into the kernel failed,
2636 * we will get EINVAL rather than, say, EFAULT on at least
2639 if (errno != EINVAL) {
2640 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
2641 pcap_strerror(errno));
2646 * install_bpf_program() validates the program.
2648 * XXX - what if we already have a filter in the kernel?
2650 if (install_bpf_program(p, fp) < 0)
2652 p->md.use_bpf = 0; /* filtering in userland */
2657 * Set direction flag: Which packets do we accept on a forwarding
2658 * single device? IN, OUT or both?
2661 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d)
2663 #if defined(BIOCSDIRECTION)
2666 direction = (d == PCAP_D_IN) ? BPF_D_IN :
2667 ((d == PCAP_D_OUT) ? BPF_D_OUT : BPF_D_INOUT);
2668 if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) {
2669 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2670 "Cannot set direction to %s: %s",
2671 (d == PCAP_D_IN) ? "PCAP_D_IN" :
2672 ((d == PCAP_D_OUT) ? "PCAP_D_OUT" : "PCAP_D_INOUT"),
2677 #elif defined(BIOCSSEESENT)
2681 * We don't support PCAP_D_OUT.
2683 if (d == PCAP_D_OUT) {
2684 snprintf(p->errbuf, sizeof(p->errbuf),
2685 "Setting direction to PCAP_D_OUT is not supported on BPF");
2689 seesent = (d == PCAP_D_INOUT);
2690 if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) {
2691 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2692 "Cannot set direction to %s: %s",
2693 (d == PCAP_D_INOUT) ? "PCAP_D_INOUT" : "PCAP_D_IN",
2699 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2700 "This system doesn't support BIOCSSEESENT, so the direction can't be set");
2706 pcap_set_datalink_bpf(pcap_t *p, int dlt)
2709 if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) {
2710 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2711 "Cannot set DLT %d: %s", dlt, strerror(errno));