2 * Copyright (c) 1990, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from the Stanford/CMU enet packet filter,
6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#)bpf.c 8.2 (Berkeley) 3/28/94
40 * $FreeBSD: src/sys/net/bpf.c,v 1.59.2.12 2002/04/14 21:41:48 luigi Exp $
41 * $DragonFly: src/sys/net/bpf.c,v 1.42 2007/10/13 09:53:51 sephe Exp $
46 #include <sys/param.h>
47 #include <sys/systm.h>
49 #include <sys/device.h>
50 #include <sys/malloc.h>
54 #include <sys/signalvar.h>
55 #include <sys/filio.h>
56 #include <sys/sockio.h>
57 #include <sys/ttycom.h>
58 #include <sys/filedesc.h>
62 #include <sys/socket.h>
63 #include <sys/vnode.h>
65 #include <sys/thread2.h>
69 #include <net/bpfdesc.h>
71 #include <netinet/in.h>
72 #include <netinet/if_ether.h>
73 #include <sys/kernel.h>
74 #include <sys/sysctl.h>
76 MALLOC_DEFINE(M_BPF
, "BPF", "BPF data");
81 * The default read buffer size is patchable.
83 static int bpf_bufsize
= BPF_DEFAULTBUFSIZE
;
84 SYSCTL_INT(_debug
, OID_AUTO
, bpf_bufsize
, CTLFLAG_RW
,
86 static int bpf_maxbufsize
= BPF_MAXBUFSIZE
;
87 SYSCTL_INT(_debug
, OID_AUTO
, bpf_maxbufsize
, CTLFLAG_RW
,
88 &bpf_maxbufsize
, 0, "");
91 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
93 static struct bpf_if
*bpf_iflist
;
95 static int bpf_allocbufs(struct bpf_d
*);
96 static void bpf_attachd(struct bpf_d
*d
, struct bpf_if
*bp
);
97 static void bpf_detachd(struct bpf_d
*d
);
98 static void bpf_resetd(struct bpf_d
*);
99 static void bpf_freed(struct bpf_d
*);
100 static void bpf_mcopy(const void *, void *, size_t);
101 static int bpf_movein(struct uio
*, int, struct mbuf
**,
102 struct sockaddr
*, int *);
103 static int bpf_setif(struct bpf_d
*, struct ifreq
*);
104 static void bpf_timed_out(void *);
105 static void bpf_wakeup(struct bpf_d
*);
106 static void catchpacket(struct bpf_d
*, u_char
*, u_int
, u_int
,
107 void (*)(const void *, void *, size_t),
108 const struct timeval
*);
109 static int bpf_setf(struct bpf_d
*, struct bpf_program
*);
110 static int bpf_getdltlist(struct bpf_d
*, struct bpf_dltlist
*);
111 static int bpf_setdlt(struct bpf_d
*, u_int
);
112 static void bpf_drvinit(void *unused
);
114 static d_open_t bpfopen
;
115 static d_close_t bpfclose
;
116 static d_read_t bpfread
;
117 static d_write_t bpfwrite
;
118 static d_ioctl_t bpfioctl
;
119 static d_poll_t bpfpoll
;
121 #define CDEV_MAJOR 23
122 static struct dev_ops bpf_ops
= {
123 { "bpf", CDEV_MAJOR
, 0 },
134 bpf_movein(struct uio
*uio
, int linktype
, struct mbuf
**mp
,
135 struct sockaddr
*sockp
, int *datlen
)
146 * Build a sockaddr based on the data link layer type.
147 * We do this at this level because the ethernet header
148 * is copied directly into the data field of the sockaddr.
149 * In the case of SLIP, there is no header and the packet
150 * is forwarded as is.
151 * Also, we are careful to leave room at the front of the mbuf
152 * for the link level header.
156 sockp
->sa_family
= AF_INET
;
161 sockp
->sa_family
= AF_UNSPEC
;
162 /* XXX Would MAXLINKHDR be better? */
163 hlen
= sizeof(struct ether_header
);
168 sockp
->sa_family
= AF_UNSPEC
;
172 case DLT_ATM_RFC1483
:
174 * en atm driver requires 4-byte atm pseudo header.
175 * though it isn't standard, vpi:vci needs to be
178 sockp
->sa_family
= AF_UNSPEC
;
179 hlen
= 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
183 sockp
->sa_family
= AF_UNSPEC
;
184 hlen
= 4; /* This should match PPP_HDRLEN */
191 len
= uio
->uio_resid
;
192 *datlen
= len
- hlen
;
193 if ((unsigned)len
> MCLBYTES
)
196 m
= m_getl(len
, MB_WAIT
, MT_DATA
, M_PKTHDR
, NULL
);
199 m
->m_pkthdr
.len
= m
->m_len
= len
;
200 m
->m_pkthdr
.rcvif
= NULL
;
203 * Make room for link header.
206 m
->m_pkthdr
.len
-= hlen
;
208 m
->m_data
+= hlen
; /* XXX */
209 error
= uiomove(sockp
->sa_data
, hlen
, uio
);
213 error
= uiomove(mtod(m
, caddr_t
), len
- hlen
, uio
);
222 * Attach file to the bpf interface, i.e. make d listen on bp.
223 * Must be called at splimp.
226 bpf_attachd(struct bpf_d
*d
, struct bpf_if
*bp
)
229 * Point d at bp, and add d to the interface's list of listeners.
230 * Finally, point the driver's bpf cookie at the interface so
231 * it will divert packets to bpf.
234 SLIST_INSERT_HEAD(&bp
->bif_dlist
, d
, bd_next
);
235 *bp
->bif_driverp
= bp
;
239 * Detach a file from its interface.
242 bpf_detachd(struct bpf_d
*d
)
251 /* Remove d from the interface's descriptor list. */
252 SLIST_REMOVE(&bp
->bif_dlist
, d
, bpf_d
, bd_next
);
254 if (SLIST_EMPTY(&bp
->bif_dlist
)) {
256 * Let the driver know that there are no more listeners.
258 *bp
->bif_driverp
= NULL
;
262 * Check if this descriptor had requested promiscuous mode.
263 * If so, turn it off.
267 error
= ifpromisc(ifp
, 0);
268 if (error
!= 0 && error
!= ENXIO
) {
270 * ENXIO can happen if a pccard is unplugged,
271 * Something is really wrong if we were able to put
272 * the driver into promiscuous mode, but can't
275 if_printf(ifp
, "bpf_detach: ifpromisc failed(%d)\n",
282 * Open ethernet device. Returns ENXIO for illegal minor device number,
283 * EBUSY if file is open by another process.
287 bpfopen(struct dev_open_args
*ap
)
289 cdev_t dev
= ap
->a_head
.a_dev
;
292 if (ap
->a_cred
->cr_prison
)
297 * Each minor can be opened by only one process. If the requested
298 * minor is in use, return EBUSY.
302 make_dev(&bpf_ops
, minor(dev
), 0, 0, 0600, "bpf%d", lminor(dev
));
303 MALLOC(d
, struct bpf_d
*, sizeof *d
, M_BPF
, M_WAITOK
| M_ZERO
);
305 d
->bd_bufsize
= bpf_bufsize
;
308 callout_init(&d
->bd_callout
);
313 * Close the descriptor by detaching it from its interface,
314 * deallocating its buffers, and marking it free.
318 bpfclose(struct dev_close_args
*ap
)
320 cdev_t dev
= ap
->a_head
.a_dev
;
321 struct bpf_d
*d
= dev
->si_drv1
;
323 funsetown(d
->bd_sigio
);
325 if (d
->bd_state
== BPF_WAITING
)
326 callout_stop(&d
->bd_callout
);
327 d
->bd_state
= BPF_IDLE
;
328 if (d
->bd_bif
!= NULL
)
339 * Rotate the packet buffers in descriptor d. Move the store buffer
340 * into the hold slot, and the free buffer into the store slot.
341 * Zero the length of the new store buffer.
343 #define ROTATE_BUFFERS(d) \
344 (d)->bd_hbuf = (d)->bd_sbuf; \
345 (d)->bd_hlen = (d)->bd_slen; \
346 (d)->bd_sbuf = (d)->bd_fbuf; \
350 * bpfread - read next chunk of packets from buffers
353 bpfread(struct dev_read_args
*ap
)
355 cdev_t dev
= ap
->a_head
.a_dev
;
356 struct bpf_d
*d
= dev
->si_drv1
;
361 * Restrict application to use a buffer the same size as
364 if (ap
->a_uio
->uio_resid
!= d
->bd_bufsize
)
368 if (d
->bd_state
== BPF_WAITING
)
369 callout_stop(&d
->bd_callout
);
370 timed_out
= (d
->bd_state
== BPF_TIMED_OUT
);
371 d
->bd_state
= BPF_IDLE
;
373 * If the hold buffer is empty, then do a timed sleep, which
374 * ends when the timeout expires or when enough packets
375 * have arrived to fill the store buffer.
377 while (d
->bd_hbuf
== NULL
) {
378 if ((d
->bd_immediate
|| timed_out
) && d
->bd_slen
!= 0) {
380 * A packet(s) either arrived since the previous
381 * read or arrived while we were asleep.
382 * Rotate the buffers and return what's here.
389 * No data is available, check to see if the bpf device
390 * is still pointed at a real interface. If not, return
391 * ENXIO so that the userland process knows to rebind
392 * it before using it again.
394 if (d
->bd_bif
== NULL
) {
399 if (ap
->a_ioflag
& IO_NDELAY
) {
403 error
= tsleep(d
, PCATCH
, "bpf", d
->bd_rtout
);
404 if (error
== EINTR
|| error
== ERESTART
) {
408 if (error
== EWOULDBLOCK
) {
410 * On a timeout, return what's in the buffer,
411 * which may be nothing. If there is something
412 * in the store buffer, we can rotate the buffers.
416 * We filled up the buffer in between
417 * getting the timeout and arriving
418 * here, so we don't need to rotate.
422 if (d
->bd_slen
== 0) {
431 * At this point, we know we have something in the hold slot.
436 * Move data from hold buffer into user space.
437 * We know the entire buffer is transferred since
438 * we checked above that the read buffer is bpf_bufsize bytes.
440 error
= uiomove(d
->bd_hbuf
, d
->bd_hlen
, ap
->a_uio
);
443 d
->bd_fbuf
= d
->bd_hbuf
;
453 * If there are processes sleeping on this descriptor, wake them up.
456 bpf_wakeup(struct bpf_d
*d
)
458 if (d
->bd_state
== BPF_WAITING
) {
459 callout_stop(&d
->bd_callout
);
460 d
->bd_state
= BPF_IDLE
;
463 if (d
->bd_async
&& d
->bd_sig
&& d
->bd_sigio
)
464 pgsigio(d
->bd_sigio
, d
->bd_sig
, 0);
467 selwakeup(&d
->bd_sel
);
470 d
->bd_sel
.si_pid
= 0;
474 bpf_timed_out(void *arg
)
476 struct bpf_d
*d
= (struct bpf_d
*)arg
;
479 if (d
->bd_state
== BPF_WAITING
) {
480 d
->bd_state
= BPF_TIMED_OUT
;
488 bpfwrite(struct dev_write_args
*ap
)
490 cdev_t dev
= ap
->a_head
.a_dev
;
491 struct bpf_d
*d
= dev
->si_drv1
;
495 static struct sockaddr dst
;
498 if (d
->bd_bif
== NULL
)
501 ifp
= d
->bd_bif
->bif_ifp
;
503 if (ap
->a_uio
->uio_resid
== 0)
506 error
= bpf_movein(ap
->a_uio
, (int)d
->bd_bif
->bif_dlt
, &m
,
511 if (datlen
> ifp
->if_mtu
) {
517 dst
.sa_family
= pseudo_AF_HDRCMPLT
;
520 lwkt_serialize_enter(ifp
->if_serializer
);
521 error
= (*ifp
->if_output
)(ifp
, m
, &dst
, (struct rtentry
*)NULL
);
522 lwkt_serialize_exit(ifp
->if_serializer
);
525 * The driver frees the mbuf.
531 * Reset a descriptor by flushing its packet buffer and clearing the
532 * receive and drop counts. Should be called at splimp.
535 bpf_resetd(struct bpf_d
*d
)
538 /* Free the hold buffer. */
539 d
->bd_fbuf
= d
->bd_hbuf
;
549 * FIONREAD Check for read packet available.
550 * SIOCGIFADDR Get interface address - convenient hook to driver.
551 * BIOCGBLEN Get buffer len [for read()].
552 * BIOCSETF Set ethernet read filter.
553 * BIOCFLUSH Flush read packet buffer.
554 * BIOCPROMISC Put interface into promiscuous mode.
555 * BIOCGDLT Get link layer type.
556 * BIOCGETIF Get interface name.
557 * BIOCSETIF Set interface.
558 * BIOCSRTIMEOUT Set read timeout.
559 * BIOCGRTIMEOUT Get read timeout.
560 * BIOCGSTATS Get packet stats.
561 * BIOCIMMEDIATE Set immediate mode.
562 * BIOCVERSION Get filter language version.
563 * BIOCGHDRCMPLT Get "header already complete" flag
564 * BIOCSHDRCMPLT Set "header already complete" flag
565 * BIOCGSEESENT Get "see packets sent" flag
566 * BIOCSSEESENT Set "see packets sent" flag
570 bpfioctl(struct dev_ioctl_args
*ap
)
572 cdev_t dev
= ap
->a_head
.a_dev
;
573 struct bpf_d
*d
= dev
->si_drv1
;
577 if (d
->bd_state
== BPF_WAITING
)
578 callout_stop(&d
->bd_callout
);
579 d
->bd_state
= BPF_IDLE
;
588 * Check for read packet available.
600 *(int *)ap
->a_data
= n
;
608 if (d
->bd_bif
== NULL
) {
611 ifp
= d
->bd_bif
->bif_ifp
;
612 lwkt_serialize_enter(ifp
->if_serializer
);
613 error
= ifp
->if_ioctl(ifp
, ap
->a_cmd
,
614 ap
->a_data
, ap
->a_cred
);
615 lwkt_serialize_exit(ifp
->if_serializer
);
621 * Get buffer len [for read()].
624 *(u_int
*)ap
->a_data
= d
->bd_bufsize
;
631 if (d
->bd_bif
!= NULL
) {
634 u_int size
= *(u_int
*)ap
->a_data
;
636 if (size
> bpf_maxbufsize
)
637 *(u_int
*)ap
->a_data
= size
= bpf_maxbufsize
;
638 else if (size
< BPF_MINBUFSIZE
)
639 *(u_int
*)ap
->a_data
= size
= BPF_MINBUFSIZE
;
640 d
->bd_bufsize
= size
;
645 * Set link layer read filter.
648 error
= bpf_setf(d
, (struct bpf_program
*)ap
->a_data
);
652 * Flush read packet buffer.
661 * Put interface into promiscuous mode.
664 if (d
->bd_bif
== NULL
) {
666 * No interface attached yet.
672 if (d
->bd_promisc
== 0) {
673 error
= ifpromisc(d
->bd_bif
->bif_ifp
, 1);
681 * Get device parameters.
684 if (d
->bd_bif
== NULL
)
687 *(u_int
*)ap
->a_data
= d
->bd_bif
->bif_dlt
;
691 * Get a list of supported data link types.
694 if (d
->bd_bif
== NULL
) {
697 error
= bpf_getdltlist(d
,
698 (struct bpf_dltlist
*)ap
->a_data
);
703 * Set data link type.
706 if (d
->bd_bif
== NULL
)
709 error
= bpf_setdlt(d
, *(u_int
*)ap
->a_data
);
713 * Get interface name.
716 if (d
->bd_bif
== NULL
) {
719 struct ifnet
*const ifp
= d
->bd_bif
->bif_ifp
;
720 struct ifreq
*const ifr
= (struct ifreq
*)ap
->a_data
;
722 strlcpy(ifr
->ifr_name
, ifp
->if_xname
,
723 sizeof ifr
->ifr_name
);
731 error
= bpf_setif(d
, (struct ifreq
*)ap
->a_data
);
739 struct timeval
*tv
= (struct timeval
*)ap
->a_data
;
742 * Subtract 1 tick from tvtohz() since this isn't
745 if ((error
= itimerfix(tv
)) == 0)
746 d
->bd_rtout
= tvtohz_low(tv
);
755 struct timeval
*tv
= (struct timeval
*)ap
->a_data
;
757 tv
->tv_sec
= d
->bd_rtout
/ hz
;
758 tv
->tv_usec
= (d
->bd_rtout
% hz
) * tick
;
767 struct bpf_stat
*bs
= (struct bpf_stat
*)ap
->a_data
;
769 bs
->bs_recv
= d
->bd_rcount
;
770 bs
->bs_drop
= d
->bd_dcount
;
775 * Set immediate mode.
778 d
->bd_immediate
= *(u_int
*)ap
->a_data
;
783 struct bpf_version
*bv
= (struct bpf_version
*)ap
->a_data
;
785 bv
->bv_major
= BPF_MAJOR_VERSION
;
786 bv
->bv_minor
= BPF_MINOR_VERSION
;
791 * Get "header already complete" flag
794 *(u_int
*)ap
->a_data
= d
->bd_hdrcmplt
;
798 * Set "header already complete" flag
801 d
->bd_hdrcmplt
= *(u_int
*)ap
->a_data
? 1 : 0;
805 * Get "see sent packets" flag
808 *(u_int
*)ap
->a_data
= d
->bd_seesent
;
812 * Set "see sent packets" flag
815 d
->bd_seesent
= *(u_int
*)ap
->a_data
;
818 case FIOASYNC
: /* Send signal on receive packets */
819 d
->bd_async
= *(int *)ap
->a_data
;
823 error
= fsetown(*(int *)ap
->a_data
, &d
->bd_sigio
);
827 *(int *)ap
->a_data
= fgetown(d
->bd_sigio
);
830 /* This is deprecated, FIOSETOWN should be used instead. */
832 error
= fsetown(-(*(int *)ap
->a_data
), &d
->bd_sigio
);
835 /* This is deprecated, FIOGETOWN should be used instead. */
837 *(int *)ap
->a_data
= -fgetown(d
->bd_sigio
);
840 case BIOCSRSIG
: /* Set receive signal */
844 sig
= *(u_int
*)ap
->a_data
;
853 *(u_int
*)ap
->a_data
= d
->bd_sig
;
860 * Set d's packet filter program to fp. If this file already has a filter,
861 * free it and replace it. Returns EINVAL for bogus requests.
864 bpf_setf(struct bpf_d
*d
, struct bpf_program
*fp
)
866 struct bpf_insn
*fcode
, *old
;
870 if (fp
->bf_insns
== NULL
) {
882 if (flen
> BPF_MAXINSNS
)
885 size
= flen
* sizeof *fp
->bf_insns
;
886 fcode
= (struct bpf_insn
*)kmalloc(size
, M_BPF
, M_WAITOK
);
887 if (copyin(fp
->bf_insns
, fcode
, size
) == 0 &&
888 bpf_validate(fcode
, (int)flen
)) {
890 d
->bd_filter
= fcode
;
903 * Detach a file from its current interface (if attached at all) and attach
904 * to the interface indicated by the name stored in ifr.
905 * Return an errno or 0.
908 bpf_setif(struct bpf_d
*d
, struct ifreq
*ifr
)
912 struct ifnet
*theywant
;
914 theywant
= ifunit(ifr
->ifr_name
);
915 if (theywant
== NULL
)
919 * Look through attached interfaces for the named one.
921 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
922 struct ifnet
*ifp
= bp
->bif_ifp
;
924 if (ifp
== NULL
|| ifp
!= theywant
)
926 /* skip additional entry */
927 if (bp
->bif_driverp
!= &ifp
->if_bpf
)
930 * We found the requested interface.
931 * If it's not up, return an error.
932 * Allocate the packet buffers if we need to.
933 * If we're already attached to requested interface,
934 * just flush the buffer.
936 if (!(ifp
->if_flags
& IFF_UP
))
939 if (d
->bd_sbuf
== NULL
) {
940 error
= bpf_allocbufs(d
);
945 if (bp
!= d
->bd_bif
) {
946 if (d
->bd_bif
!= NULL
) {
948 * Detach if attached to something else.
965 * Support for select() and poll() system calls
967 * Return true iff the specific operation will not block indefinitely.
968 * Otherwise, return false but make a note that a selwakeup() must be done.
971 bpfpoll(struct dev_poll_args
*ap
)
973 cdev_t dev
= ap
->a_head
.a_dev
;
978 if (d
->bd_bif
== NULL
)
981 revents
= ap
->a_events
& (POLLOUT
| POLLWRNORM
);
983 if (ap
->a_events
& (POLLIN
| POLLRDNORM
)) {
985 * An imitation of the FIONREAD ioctl code.
986 * XXX not quite. An exact imitation:
987 * if (d->b_slen != 0 ||
988 * (d->bd_hbuf != NULL && d->bd_hlen != 0)
990 if (d
->bd_hlen
!= 0 ||
991 ((d
->bd_immediate
|| d
->bd_state
== BPF_TIMED_OUT
) &&
993 revents
|= ap
->a_events
& (POLLIN
| POLLRDNORM
);
995 selrecord(curthread
, &d
->bd_sel
);
996 /* Start the read timeout if necessary. */
997 if (d
->bd_rtout
> 0 && d
->bd_state
== BPF_IDLE
) {
998 callout_reset(&d
->bd_callout
, d
->bd_rtout
,
1000 d
->bd_state
= BPF_WAITING
;
1005 ap
->a_events
= revents
;
1010 * Process the packet pkt of length pktlen. The packet is parsed
1011 * by each listener's filter, and if accepted, stashed into the
1012 * corresponding buffer.
1015 bpf_tap(struct bpf_if
*bp
, u_char
*pkt
, u_int pktlen
)
1023 * Note that the ipl does not have to be raised at this point.
1024 * The only problem that could arise here is that if two different
1025 * interfaces shared any data. This is not the case.
1027 SLIST_FOREACH(d
, &bp
->bif_dlist
, bd_next
) {
1029 slen
= bpf_filter(d
->bd_filter
, pkt
, pktlen
, pktlen
);
1035 catchpacket(d
, pkt
, pktlen
, slen
, ovbcopy
, &tv
);
1041 * Copy data from an mbuf chain into a buffer. This code is derived
1042 * from m_copydata in sys/uipc_mbuf.c.
1045 bpf_mcopy(const void *src_arg
, void *dst_arg
, size_t len
)
1047 const struct mbuf
*m
;
1056 count
= min(m
->m_len
, len
);
1057 bcopy(mtod(m
, void *), dst
, count
);
1065 * Process the packet in the mbuf chain m. The packet is parsed by each
1066 * listener's filter, and if accepted, stashed into the corresponding
1070 bpf_mtap(struct bpf_if
*bp
, struct mbuf
*m
)
1077 /* Don't compute pktlen, if no descriptor is attached. */
1078 if (SLIST_EMPTY(&bp
->bif_dlist
))
1081 pktlen
= m_lengthm(m
, NULL
);
1083 SLIST_FOREACH(d
, &bp
->bif_dlist
, bd_next
) {
1084 if (!d
->bd_seesent
&& (m
->m_pkthdr
.rcvif
== NULL
))
1087 slen
= bpf_filter(d
->bd_filter
, (u_char
*)m
, pktlen
, 0);
1093 catchpacket(d
, (u_char
*)m
, pktlen
, slen
, bpf_mcopy
,
1100 bpf_mtap_family(struct bpf_if
*bp
, struct mbuf
*m
, sa_family_t family
)
1104 KKASSERT(family
!= AF_UNSPEC
);
1106 family4
= (u_int
)family
;
1107 bpf_ptap(bp
, m
, &family4
, sizeof(family4
));
1111 * Process the packet in the mbuf chain m with the header in m prepended.
1112 * The packet is parsed by each listener's filter, and if accepted,
1113 * stashed into the corresponding buffer.
1116 bpf_ptap(struct bpf_if
*bp
, struct mbuf
*m
, const void *data
, u_int dlen
)
1121 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1122 * Note that we cut corners here; we only setup what's
1123 * absolutely needed--this mbuf should never go anywhere else.
1126 mb
.m_data
= __DECONST(void *, data
); /* LINTED */
1128 mb
.m_pkthdr
.rcvif
= m
->m_pkthdr
.rcvif
;
1134 * Move the packet data from interface memory (pkt) into the
1135 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1136 * otherwise 0. "copy" is the routine called to do the actual data
1137 * transfer. bcopy is passed in to copy contiguous chunks, while
1138 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1139 * pkt is really an mbuf.
1142 catchpacket(struct bpf_d
*d
, u_char
*pkt
, u_int pktlen
, u_int snaplen
,
1143 void (*cpfn
)(const void *, void *, size_t),
1144 const struct timeval
*tv
)
1148 int hdrlen
= d
->bd_bif
->bif_hdrlen
;
1150 * Figure out how many bytes to move. If the packet is
1151 * greater or equal to the snapshot length, transfer that
1152 * much. Otherwise, transfer the whole packet (unless
1153 * we hit the buffer size limit).
1155 totlen
= hdrlen
+ min(snaplen
, pktlen
);
1156 if (totlen
> d
->bd_bufsize
)
1157 totlen
= d
->bd_bufsize
;
1160 * Round up the end of the previous packet to the next longword.
1162 curlen
= BPF_WORDALIGN(d
->bd_slen
);
1163 if (curlen
+ totlen
> d
->bd_bufsize
) {
1165 * This packet will overflow the storage buffer.
1166 * Rotate the buffers if we can, then wakeup any
1169 if (d
->bd_fbuf
== NULL
) {
1171 * We haven't completed the previous read yet,
1172 * so drop the packet.
1180 } else if (d
->bd_immediate
|| d
->bd_state
== BPF_TIMED_OUT
) {
1182 * Immediate mode is set, or the read timeout has
1183 * already expired during a select call. A packet
1184 * arrived, so the reader should be woken up.
1190 * Append the bpf header.
1192 hp
= (struct bpf_hdr
*)(d
->bd_sbuf
+ curlen
);
1193 hp
->bh_tstamp
= *tv
;
1194 hp
->bh_datalen
= pktlen
;
1195 hp
->bh_hdrlen
= hdrlen
;
1197 * Copy the packet data into the store buffer and update its length.
1199 (*cpfn
)(pkt
, (u_char
*)hp
+ hdrlen
, (hp
->bh_caplen
= totlen
- hdrlen
));
1200 d
->bd_slen
= curlen
+ totlen
;
1204 * Initialize all nonzero fields of a descriptor.
1207 bpf_allocbufs(struct bpf_d
*d
)
1209 d
->bd_fbuf
= kmalloc(d
->bd_bufsize
, M_BPF
, M_WAITOK
);
1210 d
->bd_sbuf
= kmalloc(d
->bd_bufsize
, M_BPF
, M_WAITOK
);
1217 * Free buffers and packet filter program currently in use by a descriptor.
1221 bpf_freed(struct bpf_d
*d
)
1224 * We don't need to lock out interrupts since this descriptor has
1225 * been detached from its interface and it yet hasn't been marked
1228 if (d
->bd_sbuf
!= NULL
) {
1229 kfree(d
->bd_sbuf
, M_BPF
);
1230 if (d
->bd_hbuf
!= NULL
)
1231 kfree(d
->bd_hbuf
, M_BPF
);
1232 if (d
->bd_fbuf
!= NULL
)
1233 kfree(d
->bd_fbuf
, M_BPF
);
1235 if (d
->bd_filter
!= NULL
)
1236 kfree(d
->bd_filter
, M_BPF
);
1240 * Attach an interface to bpf. ifp is a pointer to the structure
1241 * defining the interface to be attached, dlt is the link layer type,
1242 * and hdrlen is the fixed size of the link header (variable length
1243 * headers are not yet supported).
1246 bpfattach(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
)
1248 bpfattach_dlt(ifp
, dlt
, hdrlen
, &ifp
->if_bpf
);
1252 bpfattach_dlt(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
, struct bpf_if
**driverp
)
1256 bp
= kmalloc(sizeof *bp
, M_BPF
, M_WAITOK
| M_ZERO
);
1258 SLIST_INIT(&bp
->bif_dlist
);
1261 bp
->bif_driverp
= driverp
;
1262 *bp
->bif_driverp
= NULL
;
1264 bp
->bif_next
= bpf_iflist
;
1268 * Compute the length of the bpf header. This is not necessarily
1269 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1270 * that the network layer header begins on a longword boundary (for
1271 * performance reasons and to alleviate alignment restrictions).
1273 bp
->bif_hdrlen
= BPF_WORDALIGN(hdrlen
+ SIZEOF_BPF_HDR
) - hdrlen
;
1276 if_printf(ifp
, "bpf attached\n");
1280 * Detach bpf from an interface. This involves detaching each descriptor
1281 * associated with the interface, and leaving bd_bif NULL. Notify each
1282 * descriptor as it's detached so that any sleepers wake up and get
1286 bpfdetach(struct ifnet
*ifp
)
1288 struct bpf_if
*bp
, *bp_prev
;
1293 /* Locate BPF interface information */
1295 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1296 if (ifp
== bp
->bif_ifp
)
1301 /* Interface wasn't attached */
1302 if (bp
->bif_ifp
== NULL
) {
1304 kprintf("bpfdetach: %s was not attached\n", ifp
->if_xname
);
1308 while ((d
= SLIST_FIRST(&bp
->bif_dlist
)) != NULL
) {
1313 if (bp_prev
!= NULL
)
1314 bp_prev
->bif_next
= bp
->bif_next
;
1316 bpf_iflist
= bp
->bif_next
;
1324 * Get a list of available data link type of the interface.
1327 bpf_getdltlist(struct bpf_d
*d
, struct bpf_dltlist
*bfl
)
1333 ifp
= d
->bd_bif
->bif_ifp
;
1336 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1337 if (bp
->bif_ifp
!= ifp
)
1339 if (bfl
->bfl_list
!= NULL
) {
1340 if (n
>= bfl
->bfl_len
) {
1343 error
= copyout(&bp
->bif_dlt
,
1344 bfl
->bfl_list
+ n
, sizeof(u_int
));
1353 * Set the data link type of a BPF instance.
1356 bpf_setdlt(struct bpf_d
*d
, u_int dlt
)
1358 int error
, opromisc
;
1362 if (d
->bd_bif
->bif_dlt
== dlt
)
1364 ifp
= d
->bd_bif
->bif_ifp
;
1365 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1366 if (bp
->bif_ifp
== ifp
&& bp
->bif_dlt
== dlt
)
1370 opromisc
= d
->bd_promisc
;
1376 error
= ifpromisc(bp
->bif_ifp
, 1);
1378 if_printf(bp
->bif_ifp
,
1379 "bpf_setdlt: ifpromisc failed (%d)\n",
1387 return(bp
== NULL
? EINVAL
: 0);
1391 bpf_drvinit(void *unused
)
1393 dev_ops_add(&bpf_ops
, 0, 0);
1396 SYSINIT(bpfdev
,SI_SUB_DRIVERS
,SI_ORDER_MIDDLE
+CDEV_MAJOR
,bpf_drvinit
,NULL
)
1400 * NOP stubs to allow bpf-using drivers to load and function.
1402 * A 'better' implementation would allow the core bpf functionality
1403 * to be loaded at runtime.
1407 bpf_tap(struct bpf_if
*bp
, u_char
*pkt
, u_int pktlen
)
1412 bpf_mtap(struct bpf_if
*bp
, struct mbuf
*m
)
1417 bpf_ptap(struct bpf_if
*bp
, struct mbuf
*m
, const void *data
, u_int dlen
)
1422 bpfattach(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
)
1427 bpfattach_dlt(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
, struct bpf_if
**driverp
)
1432 bpfdetach(struct ifnet
*ifp
)
1437 bpf_filter(const struct bpf_insn
*pc
, u_char
*p
, u_int wirelen
, u_int buflen
)
1439 return -1; /* "no filter" behaviour */