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 1.41 2007/08/27 16:15:42 hasso 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
)
143 * Build a sockaddr based on the data link layer type.
144 * We do this at this level because the ethernet header
145 * is copied directly into the data field of the sockaddr.
146 * In the case of SLIP, there is no header and the packet
147 * is forwarded as is.
148 * Also, we are careful to leave room at the front of the mbuf
149 * for the link level header.
153 sockp
->sa_family
= AF_INET
;
158 sockp
->sa_family
= AF_UNSPEC
;
159 /* XXX Would MAXLINKHDR be better? */
160 hlen
= sizeof(struct ether_header
);
165 sockp
->sa_family
= AF_UNSPEC
;
169 case DLT_ATM_RFC1483
:
171 * en atm driver requires 4-byte atm pseudo header.
172 * though it isn't standard, vpi:vci needs to be
175 sockp
->sa_family
= AF_UNSPEC
;
176 hlen
= 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
180 sockp
->sa_family
= AF_UNSPEC
;
181 hlen
= 4; /* This should match PPP_HDRLEN */
188 len
= uio
->uio_resid
;
189 *datlen
= len
- hlen
;
190 if ((unsigned)len
> MCLBYTES
)
193 m
= m_getl(len
, MB_WAIT
, MT_DATA
, M_PKTHDR
, NULL
);
196 m
->m_pkthdr
.len
= m
->m_len
= len
;
197 m
->m_pkthdr
.rcvif
= NULL
;
200 * Make room for link header.
203 m
->m_pkthdr
.len
-= hlen
;
205 m
->m_data
+= hlen
; /* XXX */
206 error
= uiomove(sockp
->sa_data
, hlen
, uio
);
210 error
= uiomove(mtod(m
, caddr_t
), len
- hlen
, uio
);
219 * Attach file to the bpf interface, i.e. make d listen on bp.
220 * Must be called at splimp.
223 bpf_attachd(struct bpf_d
*d
, struct bpf_if
*bp
)
226 * Point d at bp, and add d to the interface's list of listeners.
227 * Finally, point the driver's bpf cookie at the interface so
228 * it will divert packets to bpf.
231 SLIST_INSERT_HEAD(&bp
->bif_dlist
, d
, bd_next
);
232 *bp
->bif_driverp
= bp
;
236 * Detach a file from its interface.
239 bpf_detachd(struct bpf_d
*d
)
248 /* Remove d from the interface's descriptor list. */
249 SLIST_REMOVE(&bp
->bif_dlist
, d
, bpf_d
, bd_next
);
251 if (SLIST_EMPTY(&bp
->bif_dlist
)) {
253 * Let the driver know that there are no more listeners.
255 *bp
->bif_driverp
= NULL
;
259 * Check if this descriptor had requested promiscuous mode.
260 * If so, turn it off.
264 error
= ifpromisc(ifp
, 0);
265 if (error
!= 0 && error
!= ENXIO
) {
267 * ENXIO can happen if a pccard is unplugged,
268 * Something is really wrong if we were able to put
269 * the driver into promiscuous mode, but can't
272 if_printf(ifp
, "bpf_detach: ifpromisc failed(%d)\n",
279 * Open ethernet device. Returns ENXIO for illegal minor device number,
280 * EBUSY if file is open by another process.
284 bpfopen(struct dev_open_args
*ap
)
286 cdev_t dev
= ap
->a_head
.a_dev
;
289 if (ap
->a_cred
->cr_prison
)
294 * Each minor can be opened by only one process. If the requested
295 * minor is in use, return EBUSY.
299 make_dev(&bpf_ops
, minor(dev
), 0, 0, 0600, "bpf%d", lminor(dev
));
300 MALLOC(d
, struct bpf_d
*, sizeof *d
, M_BPF
, M_WAITOK
| M_ZERO
);
302 d
->bd_bufsize
= bpf_bufsize
;
305 callout_init(&d
->bd_callout
);
310 * Close the descriptor by detaching it from its interface,
311 * deallocating its buffers, and marking it free.
315 bpfclose(struct dev_close_args
*ap
)
317 cdev_t dev
= ap
->a_head
.a_dev
;
318 struct bpf_d
*d
= dev
->si_drv1
;
320 funsetown(d
->bd_sigio
);
322 if (d
->bd_state
== BPF_WAITING
)
323 callout_stop(&d
->bd_callout
);
324 d
->bd_state
= BPF_IDLE
;
325 if (d
->bd_bif
!= NULL
)
336 * Rotate the packet buffers in descriptor d. Move the store buffer
337 * into the hold slot, and the free buffer into the store slot.
338 * Zero the length of the new store buffer.
340 #define ROTATE_BUFFERS(d) \
341 (d)->bd_hbuf = (d)->bd_sbuf; \
342 (d)->bd_hlen = (d)->bd_slen; \
343 (d)->bd_sbuf = (d)->bd_fbuf; \
347 * bpfread - read next chunk of packets from buffers
350 bpfread(struct dev_read_args
*ap
)
352 cdev_t dev
= ap
->a_head
.a_dev
;
353 struct bpf_d
*d
= dev
->si_drv1
;
358 * Restrict application to use a buffer the same size as
361 if (ap
->a_uio
->uio_resid
!= d
->bd_bufsize
)
365 if (d
->bd_state
== BPF_WAITING
)
366 callout_stop(&d
->bd_callout
);
367 timed_out
= (d
->bd_state
== BPF_TIMED_OUT
);
368 d
->bd_state
= BPF_IDLE
;
370 * If the hold buffer is empty, then do a timed sleep, which
371 * ends when the timeout expires or when enough packets
372 * have arrived to fill the store buffer.
374 while (d
->bd_hbuf
== NULL
) {
375 if ((d
->bd_immediate
|| timed_out
) && d
->bd_slen
!= 0) {
377 * A packet(s) either arrived since the previous
378 * read or arrived while we were asleep.
379 * Rotate the buffers and return what's here.
386 * No data is available, check to see if the bpf device
387 * is still pointed at a real interface. If not, return
388 * ENXIO so that the userland process knows to rebind
389 * it before using it again.
391 if (d
->bd_bif
== NULL
) {
396 if (ap
->a_ioflag
& IO_NDELAY
) {
400 error
= tsleep(d
, PCATCH
, "bpf", d
->bd_rtout
);
401 if (error
== EINTR
|| error
== ERESTART
) {
405 if (error
== EWOULDBLOCK
) {
407 * On a timeout, return what's in the buffer,
408 * which may be nothing. If there is something
409 * in the store buffer, we can rotate the buffers.
413 * We filled up the buffer in between
414 * getting the timeout and arriving
415 * here, so we don't need to rotate.
419 if (d
->bd_slen
== 0) {
428 * At this point, we know we have something in the hold slot.
433 * Move data from hold buffer into user space.
434 * We know the entire buffer is transferred since
435 * we checked above that the read buffer is bpf_bufsize bytes.
437 error
= uiomove(d
->bd_hbuf
, d
->bd_hlen
, ap
->a_uio
);
440 d
->bd_fbuf
= d
->bd_hbuf
;
450 * If there are processes sleeping on this descriptor, wake them up.
453 bpf_wakeup(struct bpf_d
*d
)
455 if (d
->bd_state
== BPF_WAITING
) {
456 callout_stop(&d
->bd_callout
);
457 d
->bd_state
= BPF_IDLE
;
460 if (d
->bd_async
&& d
->bd_sig
&& d
->bd_sigio
)
461 pgsigio(d
->bd_sigio
, d
->bd_sig
, 0);
464 selwakeup(&d
->bd_sel
);
467 d
->bd_sel
.si_pid
= 0;
471 bpf_timed_out(void *arg
)
473 struct bpf_d
*d
= (struct bpf_d
*)arg
;
476 if (d
->bd_state
== BPF_WAITING
) {
477 d
->bd_state
= BPF_TIMED_OUT
;
485 bpfwrite(struct dev_write_args
*ap
)
487 cdev_t dev
= ap
->a_head
.a_dev
;
488 struct bpf_d
*d
= dev
->si_drv1
;
492 static struct sockaddr dst
;
495 if (d
->bd_bif
== NULL
)
498 ifp
= d
->bd_bif
->bif_ifp
;
500 if (ap
->a_uio
->uio_resid
== 0)
503 error
= bpf_movein(ap
->a_uio
, (int)d
->bd_bif
->bif_dlt
, &m
,
508 if (datlen
> ifp
->if_mtu
) {
514 dst
.sa_family
= pseudo_AF_HDRCMPLT
;
517 lwkt_serialize_enter(ifp
->if_serializer
);
518 error
= (*ifp
->if_output
)(ifp
, m
, &dst
, (struct rtentry
*)NULL
);
519 lwkt_serialize_exit(ifp
->if_serializer
);
522 * The driver frees the mbuf.
528 * Reset a descriptor by flushing its packet buffer and clearing the
529 * receive and drop counts. Should be called at splimp.
532 bpf_resetd(struct bpf_d
*d
)
535 /* Free the hold buffer. */
536 d
->bd_fbuf
= d
->bd_hbuf
;
546 * FIONREAD Check for read packet available.
547 * SIOCGIFADDR Get interface address - convenient hook to driver.
548 * BIOCGBLEN Get buffer len [for read()].
549 * BIOCSETF Set ethernet read filter.
550 * BIOCFLUSH Flush read packet buffer.
551 * BIOCPROMISC Put interface into promiscuous mode.
552 * BIOCGDLT Get link layer type.
553 * BIOCGETIF Get interface name.
554 * BIOCSETIF Set interface.
555 * BIOCSRTIMEOUT Set read timeout.
556 * BIOCGRTIMEOUT Get read timeout.
557 * BIOCGSTATS Get packet stats.
558 * BIOCIMMEDIATE Set immediate mode.
559 * BIOCVERSION Get filter language version.
560 * BIOCGHDRCMPLT Get "header already complete" flag
561 * BIOCSHDRCMPLT Set "header already complete" flag
562 * BIOCGSEESENT Get "see packets sent" flag
563 * BIOCSSEESENT Set "see packets sent" flag
567 bpfioctl(struct dev_ioctl_args
*ap
)
569 cdev_t dev
= ap
->a_head
.a_dev
;
570 struct bpf_d
*d
= dev
->si_drv1
;
574 if (d
->bd_state
== BPF_WAITING
)
575 callout_stop(&d
->bd_callout
);
576 d
->bd_state
= BPF_IDLE
;
585 * Check for read packet available.
597 *(int *)ap
->a_data
= n
;
605 if (d
->bd_bif
== NULL
) {
608 ifp
= d
->bd_bif
->bif_ifp
;
609 lwkt_serialize_enter(ifp
->if_serializer
);
610 error
= ifp
->if_ioctl(ifp
, ap
->a_cmd
,
611 ap
->a_data
, ap
->a_cred
);
612 lwkt_serialize_exit(ifp
->if_serializer
);
618 * Get buffer len [for read()].
621 *(u_int
*)ap
->a_data
= d
->bd_bufsize
;
628 if (d
->bd_bif
!= NULL
) {
631 u_int size
= *(u_int
*)ap
->a_data
;
633 if (size
> bpf_maxbufsize
)
634 *(u_int
*)ap
->a_data
= size
= bpf_maxbufsize
;
635 else if (size
< BPF_MINBUFSIZE
)
636 *(u_int
*)ap
->a_data
= size
= BPF_MINBUFSIZE
;
637 d
->bd_bufsize
= size
;
642 * Set link layer read filter.
645 error
= bpf_setf(d
, (struct bpf_program
*)ap
->a_data
);
649 * Flush read packet buffer.
658 * Put interface into promiscuous mode.
661 if (d
->bd_bif
== NULL
) {
663 * No interface attached yet.
669 if (d
->bd_promisc
== 0) {
670 error
= ifpromisc(d
->bd_bif
->bif_ifp
, 1);
678 * Get device parameters.
681 if (d
->bd_bif
== NULL
)
684 *(u_int
*)ap
->a_data
= d
->bd_bif
->bif_dlt
;
688 * Get a list of supported data link types.
691 if (d
->bd_bif
== NULL
) {
694 error
= bpf_getdltlist(d
,
695 (struct bpf_dltlist
*)ap
->a_data
);
700 * Set data link type.
703 if (d
->bd_bif
== NULL
)
706 error
= bpf_setdlt(d
, *(u_int
*)ap
->a_data
);
710 * Get interface name.
713 if (d
->bd_bif
== NULL
) {
716 struct ifnet
*const ifp
= d
->bd_bif
->bif_ifp
;
717 struct ifreq
*const ifr
= (struct ifreq
*)ap
->a_data
;
719 strlcpy(ifr
->ifr_name
, ifp
->if_xname
,
720 sizeof ifr
->ifr_name
);
728 error
= bpf_setif(d
, (struct ifreq
*)ap
->a_data
);
736 struct timeval
*tv
= (struct timeval
*)ap
->a_data
;
739 * Subtract 1 tick from tvtohz() since this isn't
742 if ((error
= itimerfix(tv
)) == 0)
743 d
->bd_rtout
= tvtohz_low(tv
);
752 struct timeval
*tv
= (struct timeval
*)ap
->a_data
;
754 tv
->tv_sec
= d
->bd_rtout
/ hz
;
755 tv
->tv_usec
= (d
->bd_rtout
% hz
) * tick
;
764 struct bpf_stat
*bs
= (struct bpf_stat
*)ap
->a_data
;
766 bs
->bs_recv
= d
->bd_rcount
;
767 bs
->bs_drop
= d
->bd_dcount
;
772 * Set immediate mode.
775 d
->bd_immediate
= *(u_int
*)ap
->a_data
;
780 struct bpf_version
*bv
= (struct bpf_version
*)ap
->a_data
;
782 bv
->bv_major
= BPF_MAJOR_VERSION
;
783 bv
->bv_minor
= BPF_MINOR_VERSION
;
788 * Get "header already complete" flag
791 *(u_int
*)ap
->a_data
= d
->bd_hdrcmplt
;
795 * Set "header already complete" flag
798 d
->bd_hdrcmplt
= *(u_int
*)ap
->a_data
? 1 : 0;
802 * Get "see sent packets" flag
805 *(u_int
*)ap
->a_data
= d
->bd_seesent
;
809 * Set "see sent packets" flag
812 d
->bd_seesent
= *(u_int
*)ap
->a_data
;
815 case FIOASYNC
: /* Send signal on receive packets */
816 d
->bd_async
= *(int *)ap
->a_data
;
820 error
= fsetown(*(int *)ap
->a_data
, &d
->bd_sigio
);
824 *(int *)ap
->a_data
= fgetown(d
->bd_sigio
);
827 /* This is deprecated, FIOSETOWN should be used instead. */
829 error
= fsetown(-(*(int *)ap
->a_data
), &d
->bd_sigio
);
832 /* This is deprecated, FIOGETOWN should be used instead. */
834 *(int *)ap
->a_data
= -fgetown(d
->bd_sigio
);
837 case BIOCSRSIG
: /* Set receive signal */
841 sig
= *(u_int
*)ap
->a_data
;
850 *(u_int
*)ap
->a_data
= d
->bd_sig
;
857 * Set d's packet filter program to fp. If this file already has a filter,
858 * free it and replace it. Returns EINVAL for bogus requests.
861 bpf_setf(struct bpf_d
*d
, struct bpf_program
*fp
)
863 struct bpf_insn
*fcode
, *old
;
867 if (fp
->bf_insns
== NULL
) {
879 if (flen
> BPF_MAXINSNS
)
882 size
= flen
* sizeof *fp
->bf_insns
;
883 fcode
= (struct bpf_insn
*)kmalloc(size
, M_BPF
, M_WAITOK
);
884 if (copyin(fp
->bf_insns
, fcode
, size
) == 0 &&
885 bpf_validate(fcode
, (int)flen
)) {
887 d
->bd_filter
= fcode
;
900 * Detach a file from its current interface (if attached at all) and attach
901 * to the interface indicated by the name stored in ifr.
902 * Return an errno or 0.
905 bpf_setif(struct bpf_d
*d
, struct ifreq
*ifr
)
909 struct ifnet
*theywant
;
911 theywant
= ifunit(ifr
->ifr_name
);
912 if (theywant
== NULL
)
916 * Look through attached interfaces for the named one.
918 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
919 struct ifnet
*ifp
= bp
->bif_ifp
;
921 if (ifp
== NULL
|| ifp
!= theywant
)
923 /* skip additional entry */
924 if (bp
->bif_driverp
!= &ifp
->if_bpf
)
927 * We found the requested interface.
928 * If it's not up, return an error.
929 * Allocate the packet buffers if we need to.
930 * If we're already attached to requested interface,
931 * just flush the buffer.
933 if (!(ifp
->if_flags
& IFF_UP
))
936 if (d
->bd_sbuf
== NULL
) {
937 error
= bpf_allocbufs(d
);
942 if (bp
!= d
->bd_bif
) {
943 if (d
->bd_bif
!= NULL
) {
945 * Detach if attached to something else.
962 * Support for select() and poll() system calls
964 * Return true iff the specific operation will not block indefinitely.
965 * Otherwise, return false but make a note that a selwakeup() must be done.
968 bpfpoll(struct dev_poll_args
*ap
)
970 cdev_t dev
= ap
->a_head
.a_dev
;
975 if (d
->bd_bif
== NULL
)
978 revents
= ap
->a_events
& (POLLOUT
| POLLWRNORM
);
980 if (ap
->a_events
& (POLLIN
| POLLRDNORM
)) {
982 * An imitation of the FIONREAD ioctl code.
983 * XXX not quite. An exact imitation:
984 * if (d->b_slen != 0 ||
985 * (d->bd_hbuf != NULL && d->bd_hlen != 0)
987 if (d
->bd_hlen
!= 0 ||
988 ((d
->bd_immediate
|| d
->bd_state
== BPF_TIMED_OUT
) &&
990 revents
|= ap
->a_events
& (POLLIN
| POLLRDNORM
);
992 selrecord(curthread
, &d
->bd_sel
);
993 /* Start the read timeout if necessary. */
994 if (d
->bd_rtout
> 0 && d
->bd_state
== BPF_IDLE
) {
995 callout_reset(&d
->bd_callout
, d
->bd_rtout
,
997 d
->bd_state
= BPF_WAITING
;
1002 ap
->a_events
= revents
;
1007 * Process the packet pkt of length pktlen. The packet is parsed
1008 * by each listener's filter, and if accepted, stashed into the
1009 * corresponding buffer.
1012 bpf_tap(struct bpf_if
*bp
, u_char
*pkt
, u_int pktlen
)
1020 * Note that the ipl does not have to be raised at this point.
1021 * The only problem that could arise here is that if two different
1022 * interfaces shared any data. This is not the case.
1024 SLIST_FOREACH(d
, &bp
->bif_dlist
, bd_next
) {
1026 slen
= bpf_filter(d
->bd_filter
, pkt
, pktlen
, pktlen
);
1032 catchpacket(d
, pkt
, pktlen
, slen
, ovbcopy
, &tv
);
1038 * Copy data from an mbuf chain into a buffer. This code is derived
1039 * from m_copydata in sys/uipc_mbuf.c.
1042 bpf_mcopy(const void *src_arg
, void *dst_arg
, size_t len
)
1044 const struct mbuf
*m
;
1053 count
= min(m
->m_len
, len
);
1054 bcopy(mtod(m
, void *), dst
, count
);
1062 * Process the packet in the mbuf chain m. The packet is parsed by each
1063 * listener's filter, and if accepted, stashed into the corresponding
1067 bpf_mtap(struct bpf_if
*bp
, struct mbuf
*m
)
1074 /* Don't compute pktlen, if no descriptor is attached. */
1075 if (SLIST_EMPTY(&bp
->bif_dlist
))
1078 pktlen
= m_lengthm(m
, NULL
);
1080 SLIST_FOREACH(d
, &bp
->bif_dlist
, bd_next
) {
1081 if (!d
->bd_seesent
&& (m
->m_pkthdr
.rcvif
== NULL
))
1084 slen
= bpf_filter(d
->bd_filter
, (u_char
*)m
, pktlen
, 0);
1090 catchpacket(d
, (u_char
*)m
, pktlen
, slen
, bpf_mcopy
,
1097 bpf_mtap_family(struct bpf_if
*bp
, struct mbuf
*m
, sa_family_t family
)
1101 KKASSERT(family
!= AF_UNSPEC
);
1103 family4
= (u_int
)family
;
1104 bpf_ptap(bp
, m
, &family4
, sizeof(family4
));
1108 * Process the packet in the mbuf chain m with the header in m prepended.
1109 * The packet is parsed by each listener's filter, and if accepted,
1110 * stashed into the corresponding buffer.
1113 bpf_ptap(struct bpf_if
*bp
, struct mbuf
*m
, const void *data
, u_int dlen
)
1118 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1119 * Note that we cut corners here; we only setup what's
1120 * absolutely needed--this mbuf should never go anywhere else.
1123 mb
.m_data
= __DECONST(void *, data
); /* LINTED */
1125 mb
.m_pkthdr
.rcvif
= m
->m_pkthdr
.rcvif
;
1131 * Move the packet data from interface memory (pkt) into the
1132 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1133 * otherwise 0. "copy" is the routine called to do the actual data
1134 * transfer. bcopy is passed in to copy contiguous chunks, while
1135 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1136 * pkt is really an mbuf.
1139 catchpacket(struct bpf_d
*d
, u_char
*pkt
, u_int pktlen
, u_int snaplen
,
1140 void (*cpfn
)(const void *, void *, size_t),
1141 const struct timeval
*tv
)
1145 int hdrlen
= d
->bd_bif
->bif_hdrlen
;
1147 * Figure out how many bytes to move. If the packet is
1148 * greater or equal to the snapshot length, transfer that
1149 * much. Otherwise, transfer the whole packet (unless
1150 * we hit the buffer size limit).
1152 totlen
= hdrlen
+ min(snaplen
, pktlen
);
1153 if (totlen
> d
->bd_bufsize
)
1154 totlen
= d
->bd_bufsize
;
1157 * Round up the end of the previous packet to the next longword.
1159 curlen
= BPF_WORDALIGN(d
->bd_slen
);
1160 if (curlen
+ totlen
> d
->bd_bufsize
) {
1162 * This packet will overflow the storage buffer.
1163 * Rotate the buffers if we can, then wakeup any
1166 if (d
->bd_fbuf
== NULL
) {
1168 * We haven't completed the previous read yet,
1169 * so drop the packet.
1177 } else if (d
->bd_immediate
|| d
->bd_state
== BPF_TIMED_OUT
) {
1179 * Immediate mode is set, or the read timeout has
1180 * already expired during a select call. A packet
1181 * arrived, so the reader should be woken up.
1187 * Append the bpf header.
1189 hp
= (struct bpf_hdr
*)(d
->bd_sbuf
+ curlen
);
1190 hp
->bh_tstamp
= *tv
;
1191 hp
->bh_datalen
= pktlen
;
1192 hp
->bh_hdrlen
= hdrlen
;
1194 * Copy the packet data into the store buffer and update its length.
1196 (*cpfn
)(pkt
, (u_char
*)hp
+ hdrlen
, (hp
->bh_caplen
= totlen
- hdrlen
));
1197 d
->bd_slen
= curlen
+ totlen
;
1201 * Initialize all nonzero fields of a descriptor.
1204 bpf_allocbufs(struct bpf_d
*d
)
1206 d
->bd_fbuf
= kmalloc(d
->bd_bufsize
, M_BPF
, M_WAITOK
);
1207 d
->bd_sbuf
= kmalloc(d
->bd_bufsize
, M_BPF
, M_WAITOK
);
1214 * Free buffers and packet filter program currently in use by a descriptor.
1218 bpf_freed(struct bpf_d
*d
)
1221 * We don't need to lock out interrupts since this descriptor has
1222 * been detached from its interface and it yet hasn't been marked
1225 if (d
->bd_sbuf
!= NULL
) {
1226 kfree(d
->bd_sbuf
, M_BPF
);
1227 if (d
->bd_hbuf
!= NULL
)
1228 kfree(d
->bd_hbuf
, M_BPF
);
1229 if (d
->bd_fbuf
!= NULL
)
1230 kfree(d
->bd_fbuf
, M_BPF
);
1232 if (d
->bd_filter
!= NULL
)
1233 kfree(d
->bd_filter
, M_BPF
);
1237 * Attach an interface to bpf. ifp is a pointer to the structure
1238 * defining the interface to be attached, dlt is the link layer type,
1239 * and hdrlen is the fixed size of the link header (variable length
1240 * headers are not yet supported).
1243 bpfattach(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
)
1245 bpfattach_dlt(ifp
, dlt
, hdrlen
, &ifp
->if_bpf
);
1249 bpfattach_dlt(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
, struct bpf_if
**driverp
)
1253 bp
= kmalloc(sizeof *bp
, M_BPF
, M_WAITOK
| M_ZERO
);
1255 SLIST_INIT(&bp
->bif_dlist
);
1258 bp
->bif_driverp
= driverp
;
1259 *bp
->bif_driverp
= NULL
;
1261 bp
->bif_next
= bpf_iflist
;
1265 * Compute the length of the bpf header. This is not necessarily
1266 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1267 * that the network layer header begins on a longword boundary (for
1268 * performance reasons and to alleviate alignment restrictions).
1270 bp
->bif_hdrlen
= BPF_WORDALIGN(hdrlen
+ SIZEOF_BPF_HDR
) - hdrlen
;
1273 if_printf(ifp
, "bpf attached\n");
1277 * Detach bpf from an interface. This involves detaching each descriptor
1278 * associated with the interface, and leaving bd_bif NULL. Notify each
1279 * descriptor as it's detached so that any sleepers wake up and get
1283 bpfdetach(struct ifnet
*ifp
)
1285 struct bpf_if
*bp
, *bp_prev
;
1290 /* Locate BPF interface information */
1292 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1293 if (ifp
== bp
->bif_ifp
)
1298 /* Interface wasn't attached */
1299 if (bp
->bif_ifp
== NULL
) {
1301 kprintf("bpfdetach: %s was not attached\n", ifp
->if_xname
);
1305 while ((d
= SLIST_FIRST(&bp
->bif_dlist
)) != NULL
) {
1310 if (bp_prev
!= NULL
)
1311 bp_prev
->bif_next
= bp
->bif_next
;
1313 bpf_iflist
= bp
->bif_next
;
1321 * Get a list of available data link type of the interface.
1324 bpf_getdltlist(struct bpf_d
*d
, struct bpf_dltlist
*bfl
)
1330 ifp
= d
->bd_bif
->bif_ifp
;
1333 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1334 if (bp
->bif_ifp
!= ifp
)
1336 if (bfl
->bfl_list
!= NULL
) {
1337 if (n
>= bfl
->bfl_len
) {
1340 error
= copyout(&bp
->bif_dlt
,
1341 bfl
->bfl_list
+ n
, sizeof(u_int
));
1350 * Set the data link type of a BPF instance.
1353 bpf_setdlt(struct bpf_d
*d
, u_int dlt
)
1355 int error
, opromisc
;
1359 if (d
->bd_bif
->bif_dlt
== dlt
)
1361 ifp
= d
->bd_bif
->bif_ifp
;
1362 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1363 if (bp
->bif_ifp
== ifp
&& bp
->bif_dlt
== dlt
)
1367 opromisc
= d
->bd_promisc
;
1373 error
= ifpromisc(bp
->bif_ifp
, 1);
1375 if_printf(bp
->bif_ifp
,
1376 "bpf_setdlt: ifpromisc failed (%d)\n",
1384 return(bp
== NULL
? EINVAL
: 0);
1388 bpf_drvinit(void *unused
)
1390 dev_ops_add(&bpf_ops
, 0, 0);
1393 SYSINIT(bpfdev
,SI_SUB_DRIVERS
,SI_ORDER_MIDDLE
+CDEV_MAJOR
,bpf_drvinit
,NULL
)
1397 * NOP stubs to allow bpf-using drivers to load and function.
1399 * A 'better' implementation would allow the core bpf functionality
1400 * to be loaded at runtime.
1404 bpf_tap(struct bpf_if
*bp
, u_char
*pkt
, u_int pktlen
)
1409 bpf_mtap(struct bpf_if
*bp
, struct mbuf
*m
)
1414 bpf_ptap(struct bpf_if
*bp
, struct mbuf
*m
, const void *data
, u_int dlen
)
1419 bpfattach(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
)
1424 bpfattach_dlt(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
, struct bpf_if
**driverp
)
1429 bpfdetach(struct ifnet
*ifp
)
1434 bpf_filter(const struct bpf_insn
*pc
, u_char
*p
, u_int wirelen
, u_int buflen
)
1436 return -1; /* "no filter" behaviour */