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.
22 static const char rcsid[] _U_ =
23 "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.99.2.17 2008-09-16 18:43:02 guy Exp $ (LBL)";
30 #include <sys/param.h> /* optionally get BSD define */
31 #ifdef HAVE_ZEROCOPY_BPF
35 #include <sys/timeb.h>
36 #include <sys/socket.h>
38 #include <sys/ioctl.h>
39 #include <sys/utsname.h>
41 #ifdef HAVE_ZEROCOPY_BPF
42 #include <machine/atomic.h>
50 * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the
51 * native OS version, as we need "struct bpf_config" from it.
53 #define PCAP_DONT_INCLUDE_PCAP_BPF_H
55 #include <sys/types.h>
58 * Prevent bpf.h from redefining the DLT_ values to their
59 * IFT_ values, as we're going to return the standard libpcap
60 * values, not IBM's non-standard IFT_ values.
66 #include <net/if_types.h> /* for IFT_ values */
67 #include <sys/sysconfig.h>
68 #include <sys/device.h>
69 #include <sys/cfgodm.h>
73 #define domakedev makedev64
74 #define getmajor major64
75 #define bpf_hdr bpf_hdr32
77 #define domakedev makedev
78 #define getmajor major
79 #endif /* __64BIT__ */
81 #define BPF_NAME "bpf"
83 #define DRIVER_PATH "/usr/lib/drivers"
84 #define BPF_NODE "/dev/bpf"
85 static int bpfloadedflag = 0;
86 static int odmlockid = 0;
102 #ifdef HAVE_NET_IF_MEDIA_H
103 # include <net/if_media.h>
106 #include "pcap-int.h"
109 #include "pcap-dag.h"
110 #endif /* HAVE_DAG_API */
112 #ifdef HAVE_OS_PROTO_H
113 #include "os-proto.h"
117 # if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__)
118 #define HAVE_BSD_IEEE80211
121 # if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)
122 static int find_802_11(struct bpf_dltlist *);
124 # ifdef HAVE_BSD_IEEE80211
125 static int monitor_mode(pcap_t *, int);
128 # if defined(__APPLE__)
129 static void remove_en(pcap_t *);
130 static void remove_802_11(pcap_t *);
133 # endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */
135 #endif /* BIOCGDLTLIST */
138 * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably
139 * don't get DLT_DOCSIS defined.
142 #define DLT_DOCSIS 143
146 * On OS X, we don't even get any of the 802.11-plus-radio-header DLT_'s
147 * defined, even though some of them are used by various Airport drivers.
149 #ifndef DLT_PRISM_HEADER
150 #define DLT_PRISM_HEADER 119
152 #ifndef DLT_AIRONET_HEADER
153 #define DLT_AIRONET_HEADER 120
155 #ifndef DLT_IEEE802_11_RADIO
156 #define DLT_IEEE802_11_RADIO 127
158 #ifndef DLT_IEEE802_11_RADIO_AVS
159 #define DLT_IEEE802_11_RADIO_AVS 163
162 static int pcap_can_set_rfmon_bpf(pcap_t *p);
163 static int pcap_activate_bpf(pcap_t *p);
164 static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp);
165 static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t);
166 static int pcap_set_datalink_bpf(pcap_t *p, int dlt);
168 #ifdef HAVE_ZEROCOPY_BPF
170 * For zerocopy bpf, we need to override the setnonblock/getnonblock routines
171 * so we don't call select(2) if the pcap handle is in non-blocking mode. We
172 * preserve the timeout supplied by pcap_open functions to make sure it
173 * does not get clobbered if the pcap handle moves between blocking and non-
177 pcap_getnonblock_zbuf(pcap_t *p, char *errbuf)
180 * Use a negative value for the timeout to represent that the
181 * pcap handle is in non-blocking mode.
183 return (p->md.timeout < 0);
187 pcap_setnonblock_zbuf(pcap_t *p, int nonblock, char *errbuf)
190 * Map each value to the corresponding 2's complement, to
191 * preserve the timeout value provided with pcap_set_timeout.
192 * (from pcap-linux.c).
195 if (p->md.timeout > 0)
196 p->md.timeout = p->md.timeout * -1 - 1;
198 if (p->md.timeout < 0)
199 p->md.timeout = (p->md.timeout + 1) * -1;
204 * Zero-copy specific close method. Un-map the shared buffers then call
205 * pcap_cleanup_live_common.
208 pcap_cleanup_zbuf(pcap_t *p)
211 * Delete the mappings. Note that p->buffer gets initialized to one
212 * of the mmapped regions in this case, so do not try and free it
213 * directly; null it out so that pcap_cleanup_live_common() doesn't
216 if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL)
217 (void) munmap(p->md.zbuf1, p->md.zbufsize);
218 if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL)
219 (void) munmap(p->md.zbuf2, p->md.zbufsize);
221 pcap_cleanup_live_common(p);
225 * Zero-copy BPF buffer routines to check for and acknowledge BPF data in
226 * shared memory buffers.
228 * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer,
229 * and set up p->buffer and cc to reflect one if available. Notice that if
230 * there was no prior buffer, we select zbuf1 as this will be the first
231 * buffer filled for a fresh BPF session.
234 pcap_next_zbuf_shm(pcap_t *p, int *cc)
236 struct bpf_zbuf_header *bzh;
238 if (p->md.zbuffer == p->md.zbuf2 || p->md.zbuffer == NULL) {
239 bzh = (struct bpf_zbuf_header *)p->md.zbuf1;
240 if (bzh->bzh_user_gen !=
241 atomic_load_acq_int(&bzh->bzh_kernel_gen)) {
243 p->md.zbuffer = (u_char *)p->md.zbuf1;
244 p->buffer = p->md.zbuffer + sizeof(*bzh);
245 *cc = bzh->bzh_kernel_len;
248 } else if (p->md.zbuffer == p->md.zbuf1) {
249 bzh = (struct bpf_zbuf_header *)p->md.zbuf2;
250 if (bzh->bzh_user_gen !=
251 atomic_load_acq_int(&bzh->bzh_kernel_gen)) {
253 p->md.zbuffer = (u_char *)p->md.zbuf2;
254 p->buffer = p->md.zbuffer + sizeof(*bzh);
255 *cc = bzh->bzh_kernel_len;
264 * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using
265 * select() for data or a timeout, and possibly force rotation of the buffer
266 * in the event we time out or are in immediate mode. Invoke the shared
267 * memory check before doing system calls in order to avoid doing avoidable
271 pcap_next_zbuf(pcap_t *p, int *cc)
280 #define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000))
282 * Start out by seeing whether anything is waiting by checking the
283 * next shared memory buffer for data.
285 data = pcap_next_zbuf_shm(p, cc);
289 * If a previous sleep was interrupted due to signal delivery, make
290 * sure that the timeout gets adjusted accordingly. This requires
291 * that we analyze when the timeout should be been expired, and
292 * subtract the current time from that. If after this operation,
293 * our timeout is less then or equal to zero, handle it like a
296 tmout = p->md.timeout;
298 (void) clock_gettime(CLOCK_MONOTONIC, &cur);
299 if (p->md.interrupted && p->md.timeout) {
300 expire = TSTOMILLI(&p->md.firstsel) + p->md.timeout;
301 tmout = expire - TSTOMILLI(&cur);
304 p->md.interrupted = 0;
305 data = pcap_next_zbuf_shm(p, cc);
308 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) {
309 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
310 "BIOCROTZBUF: %s", strerror(errno));
313 return (pcap_next_zbuf_shm(p, cc));
317 * No data in the buffer, so must use select() to wait for data or
318 * the next timeout. Note that we only call select if the handle
319 * is in blocking mode.
321 if (p->md.timeout >= 0) {
323 FD_SET(p->fd, &r_set);
325 tv.tv_sec = tmout / 1000;
326 tv.tv_usec = (tmout * 1000) % 1000000;
328 r = select(p->fd + 1, &r_set, NULL, NULL,
329 p->md.timeout != 0 ? &tv : NULL);
330 if (r < 0 && errno == EINTR) {
331 if (!p->md.interrupted && p->md.timeout) {
332 p->md.interrupted = 1;
333 p->md.firstsel = cur;
337 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
338 "select: %s", strerror(errno));
342 p->md.interrupted = 0;
344 * Check again for data, which may exist now that we've either been
345 * woken up as a result of data or timed out. Try the "there's data"
346 * case first since it doesn't require a system call.
348 data = pcap_next_zbuf_shm(p, cc);
352 * Try forcing a buffer rotation to dislodge timed out or immediate
355 if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) {
356 (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
357 "BIOCROTZBUF: %s", strerror(errno));
360 return (pcap_next_zbuf_shm(p, cc));
364 * Notify kernel that we are done with the buffer. We don't reset zbuffer so
365 * that we know which buffer to use next time around.
368 pcap_ack_zbuf(pcap_t *p)
371 atomic_store_rel_int(&p->md.bzh->bzh_user_gen,
372 p->md.bzh->bzh_kernel_gen);
380 pcap_create(const char *device, char *ebuf)
385 if (strstr(device, "dag"))
386 return (dag_create(device, ebuf));
387 #endif /* HAVE_DAG_API */
389 p = pcap_create_common(device, ebuf);
393 p->activate_op = pcap_activate_bpf;
394 p->can_set_rfmon_op = pcap_can_set_rfmon_bpf;
402 #ifdef HAVE_CLONING_BPF
403 static const char device[] = "/dev/bpf";
406 char device[sizeof "/dev/bpf0000000000"];
411 * Load the bpf driver, if it isn't already loaded,
412 * and create the BPF device entries, if they don't
415 if (bpf_load(p->errbuf) == PCAP_ERROR)
419 #ifdef HAVE_CLONING_BPF
420 if ((fd = open(device, O_RDWR)) == -1 &&
421 (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) {
423 fd = PCAP_ERROR_PERM_DENIED;
426 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
427 "(cannot open device) %s: %s", device, pcap_strerror(errno));
431 * Go through all the minors and find one that isn't in use.
434 (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++);
436 * Initially try a read/write open (to allow the inject
437 * method to work). If that fails due to permission
438 * issues, fall back to read-only. This allows a
439 * non-root user to be granted specific access to pcap
440 * capabilities via file permissions.
442 * XXX - we should have an API that has a flag that
443 * controls whether to open read-only or read-write,
444 * so that denial of permission to send (or inability
445 * to send, if sending packets isn't supported on
446 * the device in question) can be indicated at open
449 fd = open(device, O_RDWR);
450 if (fd == -1 && errno == EACCES)
451 fd = open(device, O_RDONLY);
452 } while (fd < 0 && errno == EBUSY);
455 * XXX better message for all minors used
459 fd = PCAP_ERROR_PERM_DENIED;
462 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "(no devices found) %s: %s",
463 device, pcap_strerror(errno));
472 get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf)
474 memset(bdlp, 0, sizeof(*bdlp));
475 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) {
479 bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1));
480 if (bdlp->bfl_list == NULL) {
481 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
482 pcap_strerror(errno));
486 if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) {
487 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
488 "BIOCGDLTLIST: %s", pcap_strerror(errno));
489 free(bdlp->bfl_list);
494 * OK, for real Ethernet devices, add DLT_DOCSIS to the
495 * list, so that an application can let you choose it,
496 * in case you're capturing DOCSIS traffic that a Cisco
497 * Cable Modem Termination System is putting out onto
498 * an Ethernet (it doesn't put an Ethernet header onto
499 * the wire, it puts raw DOCSIS frames out on the wire
500 * inside the low-level Ethernet framing).
502 * A "real Ethernet device" is defined here as a device
503 * that has a link-layer type of DLT_EN10MB and that has
504 * no alternate link-layer types; that's done to exclude
505 * 802.11 interfaces (which might or might not be the
506 * right thing to do, but I suspect it is - Ethernet <->
507 * 802.11 bridges would probably badly mishandle frames
508 * that don't have Ethernet headers).
510 if (v == DLT_EN10MB) {
512 for (i = 0; i < bdlp->bfl_len; i++) {
513 if (bdlp->bfl_list[i] != DLT_EN10MB) {
520 * We reserved one more slot at the end of
523 bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS;
529 * EINVAL just means "we don't support this ioctl on
530 * this device"; don't treat it as an error.
532 if (errno != EINVAL) {
533 (void)snprintf(ebuf, PCAP_ERRBUF_SIZE,
534 "BIOCGDLTLIST: %s", pcap_strerror(errno));
543 pcap_can_set_rfmon_bpf(pcap_t *p)
545 #if defined(__APPLE__)
546 struct utsname osinfo;
550 struct bpf_dltlist bdl;
554 * The joys of monitor mode on OS X.
556 * Prior to 10.4, it's not supported at all.
558 * In 10.4, if adapter enN supports monitor mode, there's a
559 * wltN adapter corresponding to it; you open it, instead of
560 * enN, to get monitor mode. You get whatever link-layer
561 * headers it supplies.
563 * In 10.5, and, we assume, later releases, if adapter enN
564 * supports monitor mode, it offers, among its selectable
565 * DLT_ values, values that let you get the 802.11 header;
566 * selecting one of those values puts the adapter into monitor
567 * mode (i.e., you can't get 802.11 headers except in monitor
568 * mode, and you can't get Ethernet headers in monitor mode).
570 if (uname(&osinfo) == -1) {
572 * Can't get the OS version; just say "no".
577 * We assume osinfo.sysname is "Darwin", because
578 * __APPLE__ is defined. We just check the version.
580 if (osinfo.release[0] < '8' && osinfo.release[1] == '.') {
582 * 10.3 (Darwin 7.x) or earlier.
583 * Monitor mode not supported.
587 if (osinfo.release[0] == '8' && osinfo.release[1] == '.') {
589 * 10.4 (Darwin 8.x). s/en/wlt/, and check
590 * whether the device exists.
592 if (strncmp(p->opt.source, "en", 2) != 0) {
594 * Not an enN device; no monitor mode.
598 fd = socket(AF_INET, SOCK_DGRAM, 0);
600 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
601 "socket: %s", pcap_strerror(errno));
604 strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name));
605 strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name));
606 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
619 * Everything else is 10.5 or later; for those,
620 * we just open the enN device, and check whether
621 * we have any 802.11 devices.
623 * First, open a BPF device.
630 * Now bind to the device.
632 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name));
633 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
634 if (errno == ENETDOWN) {
636 * Return a "network down" indication, so that
637 * the application can report that rather than
638 * saying we had a mysterious failure and
639 * suggest that they report a problem to the
640 * libpcap developers.
643 return (PCAP_ERROR_IFACE_NOT_UP);
645 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
647 p->opt.source, pcap_strerror(errno));
654 * We know the default link type -- now determine all the DLTs
655 * this interface supports. If this fails with EINVAL, it's
656 * not fatal; we just don't get to use the feature later.
657 * (We don't care about DLT_DOCSIS, so we pass DLT_NULL
658 * as the default DLT for this adapter.)
660 if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) {
664 if (find_802_11(&bdl) != -1) {
666 * We have an 802.11 DLT, so we can set monitor mode.
673 #endif /* BIOCGDLTLIST */
675 #elif defined(HAVE_BSD_IEEE80211)
678 ret = monitor_mode(p, 0);
679 if (ret == PCAP_ERROR_RFMON_NOTSUP)
680 return (0); /* not an error, just a "can't do" */
682 return (1); /* success */
690 pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps)
695 * "ps_recv" counts packets handed to the filter, not packets
696 * that passed the filter. This includes packets later dropped
697 * because we ran out of buffer space.
699 * "ps_drop" counts packets dropped inside the BPF device
700 * because we ran out of buffer space. It doesn't count
701 * packets dropped by the interface driver. It counts
702 * only packets that passed the filter.
704 * Both statistics include packets not yet read from the kernel
705 * by libpcap, and thus not yet seen by the application.
707 if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) {
708 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s",
709 pcap_strerror(errno));
713 ps->ps_recv = s.bs_recv;
714 ps->ps_drop = s.bs_drop;
719 pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
723 register u_char *bp, *ep;
728 #ifdef HAVE_ZEROCOPY_BPF
734 * Has "pcap_breakloop()" been called?
738 * Yes - clear the flag that indicates that it
739 * has, and return PCAP_ERROR_BREAK to indicate
740 * that we were told to break out of the loop.
743 return (PCAP_ERROR_BREAK);
748 * When reading without zero-copy from a file descriptor, we
749 * use a single buffer and return a length of data in the
750 * buffer. With zero-copy, we update the p->buffer pointer
751 * to point at whatever underlying buffer contains the next
752 * data and update cc to reflect the data found in the
755 #ifdef HAVE_ZEROCOPY_BPF
756 if (p->md.zerocopy) {
757 if (p->buffer != NULL)
759 i = pcap_next_zbuf(p, &cc);
767 cc = read(p->fd, (char *)p->buffer, p->bufsize);
770 /* Don't choke when we get ptraced */
779 * Sigh. More AIX wonderfulness.
781 * For some unknown reason the uiomove()
782 * operation in the bpf kernel extension
783 * used to copy the buffer into user
784 * space sometimes returns EFAULT. I have
785 * no idea why this is the case given that
786 * a kernel debugger shows the user buffer
787 * is correct. This problem appears to
788 * be mostly mitigated by the memset of
789 * the buffer before it is first used.
790 * Very strange.... Shaun Clowes
792 * In any case this means that we shouldn't
793 * treat EFAULT as a fatal error; as we
794 * don't have an API for returning
795 * a "some packets were dropped since
796 * the last packet you saw" indication,
797 * we just ignore EFAULT and keep reading.
804 #if defined(sun) && !defined(BSD)
806 * Due to a SunOS bug, after 2^31 bytes, the kernel
807 * file offset overflows and read fails with EINVAL.
808 * The lseek() to 0 will fix things.
811 if (lseek(p->fd, 0L, SEEK_CUR) +
813 (void)lseek(p->fd, 0L, SEEK_SET);
819 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s",
820 pcap_strerror(errno));
828 * Loop through each packet.
830 #define bhp ((struct bpf_hdr *)bp)
836 register int caplen, hdrlen;
839 * Has "pcap_breakloop()" been called?
840 * If so, return immediately - if we haven't read any
841 * packets, clear the flag and return PCAP_ERROR_BREAK
842 * to indicate that we were told to break out of the loop,
843 * otherwise leave the flag set, so that the *next* call
844 * will break out of the loop without having read any
845 * packets, and return the number of packets we've
851 return (PCAP_ERROR_BREAK);
859 caplen = bhp->bh_caplen;
860 hdrlen = bhp->bh_hdrlen;
863 * Short-circuit evaluation: if using BPF filter
864 * in kernel, no need to do it now - we already know
865 * the packet passed the filter.
868 * Note: the filter code was generated assuming
869 * that p->fddipad was the amount of padding
870 * before the header, as that's what's required
871 * in the kernel, so we run the filter before
872 * skipping that padding.
876 bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) {
877 struct pcap_pkthdr pkthdr;
879 pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec;
882 * AIX's BPF returns seconds/nanoseconds time
883 * stamps, not seconds/microseconds time stamps.
885 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec/1000;
887 pkthdr.ts.tv_usec = bhp->bh_tstamp.tv_usec;
891 pkthdr.caplen = caplen - pad;
894 if (bhp->bh_datalen > pad)
895 pkthdr.len = bhp->bh_datalen - pad;
900 pkthdr.caplen = caplen;
901 pkthdr.len = bhp->bh_datalen;
903 (*callback)(user, &pkthdr, datap);
904 bp += BPF_WORDALIGN(caplen + hdrlen);
905 if (++n >= cnt && cnt > 0) {
914 bp += BPF_WORDALIGN(caplen + hdrlen);
923 pcap_inject_bpf(pcap_t *p, const void *buf, size_t size)
927 ret = write(p->fd, buf, size);
929 if (ret == -1 && errno == EAFNOSUPPORT) {
931 * In Mac OS X, there's a bug wherein setting the
932 * BIOCSHDRCMPLT flag causes writes to fail; see,
935 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/BIOCSHDRCMPLT-10.3.3.patch
937 * So, if, on OS X, we get EAFNOSUPPORT from the write, we
938 * assume it's due to that bug, and turn off that flag
939 * and try again. If we succeed, it either means that
940 * somebody applied the fix from that URL, or other patches
943 * http://cerberus.sourcefire.com/~jeff/archives/patches/macosx/
945 * and are running a Darwin kernel with those fixes, or
946 * that Apple fixed the problem in some OS X release.
948 u_int spoof_eth_src = 0;
950 if (ioctl(p->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
951 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
952 "send: can't turn off BIOCSHDRCMPLT: %s",
953 pcap_strerror(errno));
958 * Now try the write again.
960 ret = write(p->fd, buf, size);
962 #endif /* __APPLE__ */
964 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
965 pcap_strerror(errno));
973 bpf_odminit(char *errbuf)
977 if (odm_initialize() == -1) {
978 if (odm_err_msg(odmerrno, &errstr) == -1)
979 errstr = "Unknown error";
980 snprintf(errbuf, PCAP_ERRBUF_SIZE,
981 "bpf_load: odm_initialize failed: %s",
986 if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) {
987 if (odm_err_msg(odmerrno, &errstr) == -1)
988 errstr = "Unknown error";
989 snprintf(errbuf, PCAP_ERRBUF_SIZE,
990 "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s",
999 bpf_odmcleanup(char *errbuf)
1003 if (odm_unlock(odmlockid) == -1) {
1004 if (odm_err_msg(odmerrno, &errstr) == -1)
1005 errstr = "Unknown error";
1006 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1007 "bpf_load: odm_unlock failed: %s",
1009 return (PCAP_ERROR);
1012 if (odm_terminate() == -1) {
1013 if (odm_err_msg(odmerrno, &errstr) == -1)
1014 errstr = "Unknown error";
1015 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1016 "bpf_load: odm_terminate failed: %s",
1018 return (PCAP_ERROR);
1025 bpf_load(char *errbuf)
1029 int numminors, i, rc;
1032 struct bpf_config cfg_bpf;
1033 struct cfg_load cfg_ld;
1034 struct cfg_kmod cfg_km;
1037 * This is very very close to what happens in the real implementation
1038 * but I've fixed some (unlikely) bug situations.
1043 if (bpf_odminit(errbuf) == PCAP_ERROR)
1044 return (PCAP_ERROR);
1046 major = genmajor(BPF_NAME);
1048 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1049 "bpf_load: genmajor failed: %s", pcap_strerror(errno));
1050 return (PCAP_ERROR);
1053 minors = getminor(major, &numminors, BPF_NAME);
1055 minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1);
1057 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1058 "bpf_load: genminor failed: %s",
1059 pcap_strerror(errno));
1060 return (PCAP_ERROR);
1064 if (bpf_odmcleanup(errbuf) == PCAP_ERROR)
1065 return (PCAP_ERROR);
1067 rc = stat(BPF_NODE "0", &sbuf);
1068 if (rc == -1 && errno != ENOENT) {
1069 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1070 "bpf_load: can't stat %s: %s",
1071 BPF_NODE "0", pcap_strerror(errno));
1072 return (PCAP_ERROR);
1075 if (rc == -1 || getmajor(sbuf.st_rdev) != major) {
1076 for (i = 0; i < BPF_MINORS; i++) {
1077 sprintf(buf, "%s%d", BPF_NODE, i);
1079 if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) {
1080 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1081 "bpf_load: can't mknod %s: %s",
1082 buf, pcap_strerror(errno));
1083 return (PCAP_ERROR);
1088 /* Check if the driver is loaded */
1089 memset(&cfg_ld, 0x0, sizeof(cfg_ld));
1091 sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME);
1092 if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) ||
1093 (cfg_ld.kmid == 0)) {
1094 /* Driver isn't loaded, load it now */
1095 if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) {
1096 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1097 "bpf_load: could not load driver: %s",
1099 return (PCAP_ERROR);
1103 /* Configure the driver */
1104 cfg_km.cmd = CFG_INIT;
1105 cfg_km.kmid = cfg_ld.kmid;
1106 cfg_km.mdilen = sizeof(cfg_bpf);
1107 cfg_km.mdiptr = (void *)&cfg_bpf;
1108 for (i = 0; i < BPF_MINORS; i++) {
1109 cfg_bpf.devno = domakedev(major, i);
1110 if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) {
1111 snprintf(errbuf, PCAP_ERRBUF_SIZE,
1112 "bpf_load: could not configure driver: %s",
1114 return (PCAP_ERROR);
1125 * Turn off rfmon mode if necessary.
1128 pcap_cleanup_bpf(pcap_t *p)
1130 #ifdef HAVE_BSD_IEEE80211
1132 struct ifmediareq req;
1136 if (p->md.must_clear != 0) {
1138 * There's something we have to do when closing this
1141 #ifdef HAVE_BSD_IEEE80211
1142 if (p->md.must_clear & MUST_CLEAR_RFMON) {
1144 * We put the interface into rfmon mode;
1145 * take it out of rfmon mode.
1147 * XXX - if somebody else wants it in rfmon
1148 * mode, this code cannot know that, so it'll take
1149 * it out of rfmon mode.
1151 sock = socket(AF_INET, SOCK_DGRAM, 0);
1154 "Can't restore interface flags (socket() failed: %s).\n"
1155 "Please adjust manually.\n",
1158 memset(&req, 0, sizeof(req));
1159 strncpy(req.ifm_name, p->md.device,
1160 sizeof(req.ifm_name));
1161 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
1163 "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n"
1164 "Please adjust manually.\n",
1167 if (req.ifm_current & IFM_IEEE80211_MONITOR) {
1169 * Rfmon mode is currently on;
1172 memset(&ifr, 0, sizeof(ifr));
1173 (void)strncpy(ifr.ifr_name,
1175 sizeof(ifr.ifr_name));
1177 req.ifm_current & ~IFM_IEEE80211_MONITOR;
1178 if (ioctl(sock, SIOCSIFMEDIA,
1181 "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n"
1182 "Please adjust manually.\n",
1190 #endif /* HAVE_BSD_IEEE80211 */
1193 * Take this pcap out of the list of pcaps for which we
1194 * have to take the interface out of some mode.
1196 pcap_remove_from_pcaps_to_close(p);
1197 p->md.must_clear = 0;
1200 #ifdef HAVE_ZEROCOPY_BPF
1202 * In zero-copy mode, p->buffer is just a pointer into one of the two
1203 * memory-mapped buffers, so no need to free it.
1205 if (p->md.zerocopy) {
1206 if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL)
1207 munmap(p->md.zbuf1, p->md.zbufsize);
1208 if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL)
1209 munmap(p->md.zbuf2, p->md.zbufsize);
1212 if (p->md.device != NULL) {
1214 p->md.device = NULL;
1216 pcap_cleanup_live_common(p);
1220 check_setif_failure(pcap_t *p, int error)
1228 if (error == ENXIO) {
1230 * No such device exists.
1233 if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) {
1235 * Monitor mode was requested, and we're trying
1236 * to open a "wltN" device. Assume that this
1237 * is 10.4 and that we were asked to open an
1238 * "enN" device; if that device exists, return
1239 * "monitor mode not supported on the device".
1241 fd = socket(AF_INET, SOCK_DGRAM, 0);
1243 strlcpy(ifr.ifr_name, "en",
1244 sizeof(ifr.ifr_name));
1245 strlcat(ifr.ifr_name, p->opt.source + 3,
1246 sizeof(ifr.ifr_name));
1247 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
1249 * We assume this failed because
1250 * the underlying device doesn't
1253 err = PCAP_ERROR_NO_SUCH_DEVICE;
1254 strcpy(p->errbuf, "");
1257 * The underlying "enN" device
1258 * exists, but there's no
1259 * corresponding "wltN" device;
1260 * that means that the "enN"
1261 * device doesn't support
1262 * monitor mode, probably because
1263 * it's an Ethernet device rather
1264 * than a wireless device.
1266 err = PCAP_ERROR_RFMON_NOTSUP;
1271 * We can't find out whether there's
1272 * an underlying "enN" device, so
1273 * just report "no such device".
1275 err = PCAP_ERROR_NO_SUCH_DEVICE;
1276 strcpy(p->errbuf, "");
1284 strcpy(p->errbuf, "");
1285 return (PCAP_ERROR_NO_SUCH_DEVICE);
1286 } else if (errno == ENETDOWN) {
1288 * Return a "network down" indication, so that
1289 * the application can report that rather than
1290 * saying we had a mysterious failure and
1291 * suggest that they report a problem to the
1292 * libpcap developers.
1294 return (PCAP_ERROR_IFACE_NOT_UP);
1297 * Some other error; fill in the error string, and
1298 * return PCAP_ERROR.
1300 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s",
1301 p->opt.source, pcap_strerror(errno));
1302 return (PCAP_ERROR);
1307 pcap_activate_bpf(pcap_t *p)
1312 struct bpf_version bv;
1315 char *wltdev = NULL;
1318 struct bpf_dltlist bdl;
1319 #if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)
1322 #endif /* BIOCGDLTLIST */
1323 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
1324 u_int spoof_eth_src = 1;
1327 struct bpf_insn total_insn;
1328 struct bpf_program total_prog;
1329 struct utsname osinfo;
1330 int have_osinfo = 0;
1331 #ifdef HAVE_ZEROCOPY_BPF
1333 u_int bufmode, zbufmax;
1344 if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) {
1345 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s",
1346 pcap_strerror(errno));
1347 status = PCAP_ERROR;
1350 if (bv.bv_major != BPF_MAJOR_VERSION ||
1351 bv.bv_minor < BPF_MINOR_VERSION) {
1352 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1353 "kernel bpf filter out of date");
1354 status = PCAP_ERROR;
1358 p->md.device = strdup(p->opt.source);
1359 if (p->md.device == NULL) {
1360 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s",
1361 pcap_strerror(errno));
1362 status = PCAP_ERROR;
1367 * Attempt to find out the version of the OS on which we're running.
1369 if (uname(&osinfo) == 0)
1374 * See comment in pcap_can_set_rfmon_bpf() for an explanation
1375 * of why we check the version number.
1380 * We assume osinfo.sysname is "Darwin", because
1381 * __APPLE__ is defined. We just check the version.
1383 if (osinfo.release[0] < '8' &&
1384 osinfo.release[1] == '.') {
1386 * 10.3 (Darwin 7.x) or earlier.
1388 status = PCAP_ERROR_RFMON_NOTSUP;
1391 if (osinfo.release[0] == '8' &&
1392 osinfo.release[1] == '.') {
1394 * 10.4 (Darwin 8.x). s/en/wlt/
1396 if (strncmp(p->opt.source, "en", 2) != 0) {
1398 * Not an enN device; check
1399 * whether the device even exists.
1401 sockfd = socket(AF_INET, SOCK_DGRAM, 0);
1403 strlcpy(ifr.ifr_name,
1405 sizeof(ifr.ifr_name));
1406 if (ioctl(sockfd, SIOCGIFFLAGS,
1407 (char *)&ifr) < 0) {
1415 status = PCAP_ERROR_NO_SUCH_DEVICE;
1416 strcpy(p->errbuf, "");
1418 status = PCAP_ERROR_RFMON_NOTSUP;
1422 * We can't find out whether
1423 * the device exists, so just
1424 * report "no such device".
1426 status = PCAP_ERROR_NO_SUCH_DEVICE;
1427 strcpy(p->errbuf, "");
1431 wltdev = malloc(strlen(p->opt.source) + 2);
1432 if (wltdev == NULL) {
1433 (void)snprintf(p->errbuf,
1434 PCAP_ERRBUF_SIZE, "malloc: %s",
1435 pcap_strerror(errno));
1436 status = PCAP_ERROR;
1439 strcpy(wltdev, "wlt");
1440 strcat(wltdev, p->opt.source + 2);
1441 free(p->opt.source);
1442 p->opt.source = wltdev;
1445 * Everything else is 10.5 or later; for those,
1446 * we just open the enN device, and set the DLT.
1450 #endif /* __APPLE__ */
1451 #ifdef HAVE_ZEROCOPY_BPF
1453 * If the BPF extension to set buffer mode is present, try setting
1454 * the mode to zero-copy. If that fails, use regular buffering. If
1455 * it succeeds but other setup fails, return an error to the user.
1457 bufmode = BPF_BUFMODE_ZBUF;
1458 if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) {
1460 * We have zerocopy BPF; use it.
1465 * Set the cleanup and set/get nonblocking mode ops
1466 * as appropriate for zero-copy mode.
1468 p->cleanup_op = pcap_cleanup_zbuf;
1469 p->setnonblock_op = pcap_setnonblock_zbuf;
1470 p->getnonblock_op = pcap_getnonblock_zbuf;
1473 * How to pick a buffer size: first, query the maximum buffer
1474 * size supported by zero-copy. This also lets us quickly
1475 * determine whether the kernel generally supports zero-copy.
1476 * Then, if a buffer size was specified, use that, otherwise
1477 * query the default buffer size, which reflects kernel
1478 * policy for a desired default. Round to the nearest page
1481 if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) {
1482 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s",
1483 pcap_strerror(errno));
1487 if (p->opt.buffer_size != 0) {
1489 * A buffer size was explicitly specified; use it.
1491 v = p->opt.buffer_size;
1493 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) ||
1498 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
1500 p->md.zbufsize = roundup(v, getpagesize());
1501 if (p->md.zbufsize > zbufmax)
1502 p->md.zbufsize = zbufmax;
1503 p->md.zbuf1 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE,
1505 p->md.zbuf2 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE,
1507 if (p->md.zbuf1 == MAP_FAILED || p->md.zbuf2 == MAP_FAILED) {
1508 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s",
1509 pcap_strerror(errno));
1512 bzero(&bz, sizeof(bz));
1513 bz.bz_bufa = p->md.zbuf1;
1514 bz.bz_bufb = p->md.zbuf2;
1515 bz.bz_buflen = p->md.zbufsize;
1516 if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) {
1517 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s",
1518 pcap_strerror(errno));
1521 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name));
1522 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
1523 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s",
1524 p->opt.source, pcap_strerror(errno));
1527 v = p->md.zbufsize - sizeof(struct bpf_zbuf_header);
1532 * We don't have zerocopy BPF.
1533 * Set the buffer size.
1535 if (p->opt.buffer_size != 0) {
1537 * A buffer size was explicitly specified; use it.
1539 if (ioctl(fd, BIOCSBLEN,
1540 (caddr_t)&p->opt.buffer_size) < 0) {
1541 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1542 "BIOCSBLEN: %s: %s", p->opt.source,
1543 pcap_strerror(errno));
1544 status = PCAP_ERROR;
1549 * Now bind to the device.
1551 (void)strncpy(ifr.ifr_name, p->opt.source,
1552 sizeof(ifr.ifr_name));
1553 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) {
1554 status = check_setif_failure(p, errno);
1559 * No buffer size was explicitly specified.
1561 * Try finding a good size for the buffer; 32768 may
1562 * be too big, so keep cutting it in half until we
1563 * find a size that works, or run out of sizes to try.
1564 * If the default is larger, don't make it smaller.
1566 if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) ||
1569 for ( ; v != 0; v >>= 1) {
1571 * Ignore the return value - this is because the
1572 * call fails on BPF systems that don't have
1573 * kernel malloc. And if the call fails, it's
1574 * no big deal, we just continue to use the
1575 * standard buffer size.
1577 (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v);
1579 (void)strncpy(ifr.ifr_name, p->opt.source,
1580 sizeof(ifr.ifr_name));
1581 if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0)
1582 break; /* that size worked; we're done */
1584 if (errno != ENOBUFS) {
1585 status = check_setif_failure(p, errno);
1591 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1592 "BIOCSBLEN: %s: No buffer size worked",
1594 status = PCAP_ERROR;
1600 /* Get the data link layer type. */
1601 if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) {
1602 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s",
1603 pcap_strerror(errno));
1604 status = PCAP_ERROR;
1610 * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT.
1633 * We don't know what to map this to yet.
1635 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u",
1637 status = PCAP_ERROR;
1641 #if _BSDI_VERSION - 0 >= 199510
1642 /* The SLIP and PPP link layer header changed in BSD/OS 2.1 */
1657 case 12: /*DLT_C_HDLC*/
1665 * We know the default link type -- now determine all the DLTs
1666 * this interface supports. If this fails with EINVAL, it's
1667 * not fatal; we just don't get to use the feature later.
1669 if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) {
1670 status = PCAP_ERROR;
1673 p->dlt_count = bdl.bfl_len;
1674 p->dlt_list = bdl.bfl_list;
1678 * Monitor mode fun, continued.
1680 * For 10.5 and, we're assuming, later releases, as noted above,
1681 * 802.1 adapters that support monitor mode offer both DLT_EN10MB,
1682 * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information
1683 * DLT_ value. Choosing one of the 802.11 DLT_ values will turn
1686 * Therefore, if the user asked for monitor mode, we filter out
1687 * the DLT_EN10MB value, as you can't get that in monitor mode,
1688 * and, if the user didn't ask for monitor mode, we filter out
1689 * the 802.11 DLT_ values, because selecting those will turn
1690 * monitor mode on. Then, for monitor mode, if an 802.11-plus-
1691 * radio DLT_ value is offered, we try to select that, otherwise
1692 * we try to select DLT_IEEE802_11.
1695 if (isdigit((unsigned)osinfo.release[0]) &&
1696 (osinfo.release[0] == '9' ||
1697 isdigit((unsigned)osinfo.release[1]))) {
1699 * 10.5 (Darwin 9.x), or later.
1701 new_dlt = find_802_11(&bdl);
1702 if (new_dlt != -1) {
1704 * We have at least one 802.11 DLT_ value,
1705 * so this is an 802.11 interface.
1706 * new_dlt is the best of the 802.11
1707 * DLT_ values in the list.
1711 * Our caller wants monitor mode.
1712 * Purge DLT_EN10MB from the list
1713 * of link-layer types, as selecting
1714 * it will keep monitor mode off.
1719 * If the new mode we want isn't
1720 * the default mode, attempt to
1721 * select the new mode.
1724 if (ioctl(p->fd, BIOCSDLT,
1736 * Our caller doesn't want
1737 * monitor mode. Unless this
1738 * is being done by pcap_open_live(),
1739 * purge the 802.11 link-layer types
1740 * from the list, as selecting
1741 * one of them will turn monitor
1750 * The caller requested monitor
1751 * mode, but we have no 802.11
1752 * link-layer types, so they
1755 status = PCAP_ERROR_RFMON_NOTSUP;
1761 #elif defined(HAVE_BSD_IEEE80211)
1763 * *BSD with the new 802.11 ioctls.
1764 * Do we want monitor mode?
1768 * Try to put the interface into monitor mode.
1770 status = monitor_mode(p, 1);
1779 * We're in monitor mode.
1780 * Try to find the best 802.11 DLT_ value and, if we
1781 * succeed, try to switch to that mode if we're not
1782 * already in that mode.
1784 new_dlt = find_802_11(&bdl);
1785 if (new_dlt != -1) {
1787 * We have at least one 802.11 DLT_ value.
1788 * new_dlt is the best of the 802.11
1789 * DLT_ values in the list.
1791 * If the new mode we want isn't the default mode,
1792 * attempt to select the new mode.
1795 if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) {
1797 * We succeeded; make this the
1805 #endif /* various platforms */
1806 #endif /* BIOCGDLTLIST */
1809 * If this is an Ethernet device, and we don't have a DLT_ list,
1810 * give it a list with DLT_EN10MB and DLT_DOCSIS. (That'd give
1811 * 802.11 interfaces DLT_DOCSIS, which isn't the right thing to
1812 * do, but there's not much we can do about that without finding
1813 * some other way of determining whether it's an Ethernet or 802.11
1816 if (v == DLT_EN10MB && p->dlt_count == 0) {
1817 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
1819 * If that fails, just leave the list empty.
1821 if (p->dlt_list != NULL) {
1822 p->dlt_list[0] = DLT_EN10MB;
1823 p->dlt_list[1] = DLT_DOCSIS;
1829 p->fddipad = PCAP_FDDIPAD;
1835 #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT)
1837 * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so
1838 * the link-layer source address isn't forcibly overwritten.
1839 * (Should we ignore errors? Should we do this only if
1840 * we're open for writing?)
1842 * XXX - I seem to remember some packet-sending bug in some
1843 * BSDs - check CVS log for "bpf.c"?
1845 if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) {
1846 (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
1847 "BIOCSHDRCMPLT: %s", pcap_strerror(errno));
1848 status = PCAP_ERROR;
1853 #ifdef HAVE_ZEROCOPY_BPF
1854 if (p->md.timeout != 0 && !p->md.zerocopy) {
1856 if (p->md.timeout) {
1859 * XXX - is this seconds/nanoseconds in AIX?
1860 * (Treating it as such doesn't fix the timeout
1861 * problem described below.)
1864 to.tv_sec = p->md.timeout / 1000;
1865 to.tv_usec = (p->md.timeout * 1000) % 1000000;
1866 if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) {
1867 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSRTIMEOUT: %s",
1868 pcap_strerror(errno));
1869 status = PCAP_ERROR;
1875 #ifdef BIOCIMMEDIATE
1877 * Darren Reed notes that
1879 * On AIX (4.2 at least), if BIOCIMMEDIATE is not set, the
1880 * timeout appears to be ignored and it waits until the buffer
1881 * is filled before returning. The result of not having it
1882 * set is almost worse than useless if your BPF filter
1883 * is reducing things to only a few packets (i.e. one every
1886 * so we turn BIOCIMMEDIATE mode on if this is AIX.
1888 * We don't turn it on for other platforms, as that means we
1889 * get woken up for every packet, which may not be what we want;
1890 * in the Winter 1993 USENIX paper on BPF, they say:
1892 * Since a process might want to look at every packet on a
1893 * network and the time between packets can be only a few
1894 * microseconds, it is not possible to do a read system call
1895 * per packet and BPF must collect the data from several
1896 * packets and return it as a unit when the monitoring
1897 * application does a read.
1899 * which I infer is the reason for the timeout - it means we
1900 * wait that amount of time, in the hopes that more packets
1901 * will arrive and we'll get them all with one read.
1903 * Setting BIOCIMMEDIATE mode on FreeBSD (and probably other
1904 * BSDs) causes the timeout to be ignored.
1906 * On the other hand, some platforms (e.g., Linux) don't support
1907 * timeouts, they just hand stuff to you as soon as it arrives;
1908 * if that doesn't cause a problem on those platforms, it may
1909 * be OK to have BIOCIMMEDIATE mode on BSD as well.
1911 * (Note, though, that applications may depend on the read
1912 * completing, even if no packets have arrived, when the timeout
1913 * expires, e.g. GUI applications that have to check for input
1914 * while waiting for packets to arrive; a non-zero timeout
1915 * prevents "select()" from working right on FreeBSD and
1916 * possibly other BSDs, as the timer doesn't start until a
1917 * "read()" is done, so the timer isn't in effect if the
1918 * application is blocked on a "select()", and the "select()"
1919 * doesn't get woken up for a BPF device until the buffer
1923 if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) {
1924 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s",
1925 pcap_strerror(errno));
1926 status = PCAP_ERROR;
1929 #endif /* BIOCIMMEDIATE */
1932 if (p->opt.promisc) {
1933 /* set promiscuous mode, just warn if it fails */
1934 if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) {
1935 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s",
1936 pcap_strerror(errno));
1937 status = PCAP_WARNING_PROMISC_NOTSUP;
1941 if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) {
1942 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s",
1943 pcap_strerror(errno));
1944 status = PCAP_ERROR;
1948 #ifdef HAVE_ZEROCOPY_BPF
1949 if (!p->md.zerocopy) {
1951 p->buffer = (u_char *)malloc(p->bufsize);
1952 if (p->buffer == NULL) {
1953 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s",
1954 pcap_strerror(errno));
1955 status = PCAP_ERROR;
1959 /* For some strange reason this seems to prevent the EFAULT
1960 * problems we have experienced from AIX BPF. */
1961 memset(p->buffer, 0x0, p->bufsize);
1963 #ifdef HAVE_ZEROCOPY_BPF
1968 * If there's no filter program installed, there's
1969 * no indication to the kernel of what the snapshot
1970 * length should be, so no snapshotting is done.
1972 * Therefore, when we open the device, we install
1973 * an "accept everything" filter with the specified
1976 total_insn.code = (u_short)(BPF_RET | BPF_K);
1979 total_insn.k = p->snapshot;
1981 total_prog.bf_len = 1;
1982 total_prog.bf_insns = &total_insn;
1983 if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) {
1984 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
1985 pcap_strerror(errno));
1986 status = PCAP_ERROR;
1991 * On most BPF platforms, either you can do a "select()" or
1992 * "poll()" on a BPF file descriptor and it works correctly,
1993 * or you can do it and it will return "readable" if the
1994 * hold buffer is full but not if the timeout expires *and*
1995 * a non-blocking read will, if the hold buffer is empty
1996 * but the store buffer isn't empty, rotate the buffers
1997 * and return what packets are available.
1999 * In the latter case, the fact that a non-blocking read
2000 * will give you the available packets means you can work
2001 * around the failure of "select()" and "poll()" to wake up
2002 * and return "readable" when the timeout expires by using
2003 * the timeout as the "select()" or "poll()" timeout, putting
2004 * the BPF descriptor into non-blocking mode, and read from
2005 * it regardless of whether "select()" reports it as readable
2008 * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()"
2009 * won't wake up and return "readable" if the timer expires
2010 * and non-blocking reads return EWOULDBLOCK if the hold
2011 * buffer is empty, even if the store buffer is non-empty.
2013 * This means the workaround in question won't work.
2015 * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd"
2016 * to -1, which means "sorry, you can't use 'select()' or 'poll()'
2017 * here". On all other BPF platforms, we set it to the FD for
2018 * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking
2019 * read will, if the hold buffer is empty and the store buffer
2020 * isn't empty, rotate the buffers and return what packets are
2021 * there (and in sufficiently recent versions of OpenBSD
2022 * "select()" and "poll()" should work correctly).
2024 * XXX - what about AIX?
2026 p->selectable_fd = p->fd; /* assume select() works until we know otherwise */
2029 * We can check what OS this is.
2031 if (strcmp(osinfo.sysname, "FreeBSD") == 0) {
2032 if (strncmp(osinfo.release, "4.3-", 4) == 0 ||
2033 strncmp(osinfo.release, "4.4-", 4) == 0)
2034 p->selectable_fd = -1;
2038 p->read_op = pcap_read_bpf;
2039 p->inject_op = pcap_inject_bpf;
2040 p->setfilter_op = pcap_setfilter_bpf;
2041 p->setdirection_op = pcap_setdirection_bpf;
2042 p->set_datalink_op = pcap_set_datalink_bpf;
2043 p->getnonblock_op = pcap_getnonblock_fd;
2044 p->setnonblock_op = pcap_setnonblock_fd;
2045 p->stats_op = pcap_stats_bpf;
2046 p->cleanup_op = pcap_cleanup_bpf;
2050 pcap_cleanup_bpf(p);
2055 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
2058 if (dag_platform_finddevs(alldevsp, errbuf) < 0)
2060 #endif /* HAVE_DAG_API */
2065 #ifdef HAVE_BSD_IEEE80211
2067 monitor_mode(pcap_t *p, int set)
2070 struct ifmediareq req;
2076 sock = socket(AF_INET, SOCK_DGRAM, 0);
2078 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s",
2079 pcap_strerror(errno));
2080 return (PCAP_ERROR);
2083 memset(&req, 0, sizeof req);
2084 strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name);
2087 * Find out how many media types we have.
2089 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
2091 * Can't get the media types.
2093 if (errno == EINVAL) {
2095 * Interface doesn't support SIOC{G,S}IFMEDIA.
2098 return (PCAP_ERROR_RFMON_NOTSUP);
2100 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA 1: %s",
2101 pcap_strerror(errno));
2103 return (PCAP_ERROR);
2105 if (req.ifm_count == 0) {
2110 return (PCAP_ERROR_RFMON_NOTSUP);
2114 * Allocate a buffer to hold all the media types, and
2115 * get the media types.
2117 media_list = malloc(req.ifm_count * sizeof(int));
2118 if (media_list == NULL) {
2119 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s",
2120 pcap_strerror(errno));
2122 return (PCAP_ERROR);
2124 req.ifm_ulist = media_list;
2125 if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) {
2126 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s",
2127 pcap_strerror(errno));
2130 return (PCAP_ERROR);
2134 * Look for an 802.11 "automatic" media type.
2135 * We assume that all 802.11 adapters have that media type,
2136 * and that it will carry the monitor mode supported flag.
2139 for (i = 0; i < req.ifm_count; i++) {
2140 if (IFM_TYPE(media_list[i]) == IFM_IEEE80211
2141 && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) {
2142 /* OK, does it do monitor mode? */
2143 if (media_list[i] & IFM_IEEE80211_MONITOR) {
2152 * This adapter doesn't support monitor mode.
2155 return (PCAP_ERROR_RFMON_NOTSUP);
2160 * Don't just check whether we can enable monitor mode,
2161 * do so, if it's not already enabled.
2163 if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) {
2165 * Monitor mode isn't currently on, so turn it on,
2166 * and remember that we should turn it off when the
2171 * If we haven't already done so, arrange to have
2172 * "pcap_close_all()" called when we exit.
2174 if (!pcap_do_addexit(p)) {
2176 * "atexit()" failed; don't put the interface
2177 * in monitor mode, just give up.
2179 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2182 return (PCAP_ERROR);
2184 memset(&ifr, 0, sizeof(ifr));
2185 (void)strncpy(ifr.ifr_name, p->opt.source,
2186 sizeof(ifr.ifr_name));
2187 ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR;
2188 if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) {
2189 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
2190 "SIOCSIFMEDIA: %s", pcap_strerror(errno));
2192 return (PCAP_ERROR);
2195 p->md.must_clear |= MUST_CLEAR_RFMON;
2198 * Add this to the list of pcaps to close when we exit.
2200 pcap_add_to_pcaps_to_close(p);
2205 #endif /* HAVE_BSD_IEEE80211 */
2207 #if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211))
2209 * Check whether we have any 802.11 link-layer types; return the best
2210 * of the 802.11 link-layer types if we find one, and return -1
2213 * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the
2214 * best 802.11 link-layer type; any of the other 802.11-plus-radio
2215 * headers are second-best; 802.11 with no radio information is
2219 find_802_11(struct bpf_dltlist *bdlp)
2225 * Scan the list of DLT_ values, looking for 802.11 values,
2226 * and, if we find any, choose the best of them.
2229 for (i = 0; i < bdlp->bfl_len; i++) {
2230 switch (bdlp->bfl_list[i]) {
2232 case DLT_IEEE802_11:
2234 * 802.11, but no radio.
2236 * Offer this, and select it as the new mode
2237 * unless we've already found an 802.11
2238 * header with radio information.
2241 new_dlt = bdlp->bfl_list[i];
2244 case DLT_PRISM_HEADER:
2245 case DLT_AIRONET_HEADER:
2246 case DLT_IEEE802_11_RADIO_AVS:
2248 * 802.11 with radio, but not radiotap.
2250 * Offer this, and select it as the new mode
2251 * unless we've already found the radiotap DLT_.
2253 if (new_dlt != DLT_IEEE802_11_RADIO)
2254 new_dlt = bdlp->bfl_list[i];
2257 case DLT_IEEE802_11_RADIO:
2259 * 802.11 with radiotap.
2261 * Offer this, and select it as the new mode.
2263 new_dlt = bdlp->bfl_list[i];
2276 #endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */
2278 #if defined(__APPLE__) && defined(BIOCGDLTLIST)
2280 * Remove DLT_EN10MB from the list of DLT_ values.
2283 remove_en(pcap_t *p)
2288 * Scan the list of DLT_ values and discard DLT_EN10MB.
2291 for (i = 0; i < p->dlt_count; i++) {
2292 switch (p->dlt_list[i]) {
2296 * Don't offer this one.
2302 * Just copy this mode over.
2308 * Copy this DLT_ value to its new position.
2310 p->dlt_list[j] = p->dlt_list[i];
2315 * Set the DLT_ count to the number of entries we copied.
2321 * Remove DLT_EN10MB from the list of DLT_ values, and look for the
2322 * best 802.11 link-layer type in that list and return it.
2323 * Radiotap is better than anything else; 802.11 with any other radio
2324 * header is better than 802.11 with no radio header.
2327 remove_802_11(pcap_t *p)
2332 * Scan the list of DLT_ values and discard 802.11 values.
2335 for (i = 0; i < p->dlt_count; i++) {
2336 switch (p->dlt_list[i]) {
2338 case DLT_IEEE802_11:
2339 case DLT_PRISM_HEADER:
2340 case DLT_AIRONET_HEADER:
2341 case DLT_IEEE802_11_RADIO:
2342 case DLT_IEEE802_11_RADIO_AVS:
2344 * 802.11. Don't offer this one.
2350 * Just copy this mode over.
2356 * Copy this DLT_ value to its new position.
2358 p->dlt_list[j] = p->dlt_list[i];
2363 * Set the DLT_ count to the number of entries we copied.
2367 #endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */
2370 pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp)
2373 * Free any user-mode filter we might happen to have installed.
2375 pcap_freecode(&p->fcode);
2378 * Try to install the kernel filter.
2380 if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) {
2384 p->md.use_bpf = 1; /* filtering in the kernel */
2387 * Discard any previously-received packets, as they might
2388 * have passed whatever filter was formerly in effect, but
2389 * might not pass this filter (BIOCSETF discards packets
2390 * buffered in the kernel, so you can lose packets in any
2400 * If it failed with EINVAL, that's probably because the program
2401 * is invalid or too big. Validate it ourselves; if we like it
2402 * (we currently allow backward branches, to support protochain),
2403 * run it in userland. (There's no notion of "too big" for
2406 * Otherwise, just give up.
2407 * XXX - if the copy of the program into the kernel failed,
2408 * we will get EINVAL rather than, say, EFAULT on at least
2411 if (errno != EINVAL) {
2412 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s",
2413 pcap_strerror(errno));
2418 * install_bpf_program() validates the program.
2420 * XXX - what if we already have a filter in the kernel?
2422 if (install_bpf_program(p, fp) < 0)
2424 p->md.use_bpf = 0; /* filtering in userland */
2429 * Set direction flag: Which packets do we accept on a forwarding
2430 * single device? IN, OUT or both?
2433 pcap_setdirection_bpf(pcap_t *p, pcap_direction_t d)
2435 #if defined(BIOCSDIRECTION)
2438 direction = (d == PCAP_D_IN) ? BPF_D_IN :
2439 ((d == PCAP_D_OUT) ? BPF_D_OUT : BPF_D_INOUT);
2440 if (ioctl(p->fd, BIOCSDIRECTION, &direction) == -1) {
2441 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2442 "Cannot set direction to %s: %s",
2443 (d == PCAP_D_IN) ? "PCAP_D_IN" :
2444 ((d == PCAP_D_OUT) ? "PCAP_D_OUT" : "PCAP_D_INOUT"),
2449 #elif defined(BIOCSSEESENT)
2453 * We don't support PCAP_D_OUT.
2455 if (d == PCAP_D_OUT) {
2456 snprintf(p->errbuf, sizeof(p->errbuf),
2457 "Setting direction to PCAP_D_OUT is not supported on BPF");
2461 seesent = (d == PCAP_D_INOUT);
2462 if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) {
2463 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2464 "Cannot set direction to %s: %s",
2465 (d == PCAP_D_INOUT) ? "PCAP_D_INOUT" : "PCAP_D_IN",
2471 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2472 "This system doesn't support BIOCSSEESENT, so the direction can't be set");
2478 pcap_set_datalink_bpf(pcap_t *p, int dlt)
2481 if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) {
2482 (void) snprintf(p->errbuf, sizeof(p->errbuf),
2483 "Cannot set DLT %d: %s", dlt, strerror(errno));