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 1.50 2008/09/23 11:28:49 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>
70 #include <net/netmsg2.h>
72 #include <netinet/in.h>
73 #include <netinet/if_ether.h>
74 #include <sys/kernel.h>
75 #include <sys/sysctl.h>
77 #include <sys/devfs.h>
79 struct netmsg_bpf_output
{
80 struct netmsg nm_netmsg
;
83 struct sockaddr
*nm_dst
;
86 MALLOC_DEFINE(M_BPF
, "BPF", "BPF data");
87 DEVFS_DECLARE_CLONE_BITMAP(bpf
);
88 #define BPF_PREALLOCATED_UNITS 4
93 * The default read buffer size is patchable.
95 static int bpf_bufsize
= BPF_DEFAULTBUFSIZE
;
96 SYSCTL_INT(_debug
, OID_AUTO
, bpf_bufsize
, CTLFLAG_RW
,
98 int bpf_maxbufsize
= BPF_MAXBUFSIZE
;
99 SYSCTL_INT(_debug
, OID_AUTO
, bpf_maxbufsize
, CTLFLAG_RW
,
100 &bpf_maxbufsize
, 0, "");
103 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
105 static struct bpf_if
*bpf_iflist
;
107 static int bpf_allocbufs(struct bpf_d
*);
108 static void bpf_attachd(struct bpf_d
*d
, struct bpf_if
*bp
);
109 static void bpf_detachd(struct bpf_d
*d
);
110 static void bpf_resetd(struct bpf_d
*);
111 static void bpf_freed(struct bpf_d
*);
112 static void bpf_mcopy(const void *, void *, size_t);
113 static int bpf_movein(struct uio
*, int, struct mbuf
**,
114 struct sockaddr
*, int *, struct bpf_insn
*);
115 static int bpf_setif(struct bpf_d
*, struct ifreq
*);
116 static void bpf_timed_out(void *);
117 static void bpf_wakeup(struct bpf_d
*);
118 static void catchpacket(struct bpf_d
*, u_char
*, u_int
, u_int
,
119 void (*)(const void *, void *, size_t),
120 const struct timeval
*);
121 static int bpf_setf(struct bpf_d
*, struct bpf_program
*, u_long cmd
);
122 static int bpf_getdltlist(struct bpf_d
*, struct bpf_dltlist
*);
123 static int bpf_setdlt(struct bpf_d
*, u_int
);
124 static void bpf_drvinit(void *unused
);
126 static d_open_t bpfopen
;
127 static d_clone_t bpfclone
;
128 static d_close_t bpfclose
;
129 static d_read_t bpfread
;
130 static d_write_t bpfwrite
;
131 static d_ioctl_t bpfioctl
;
132 static d_poll_t bpfpoll
;
134 #define CDEV_MAJOR 23
135 static struct dev_ops bpf_ops
= {
136 { "bpf", CDEV_MAJOR
, 0 },
147 bpf_movein(struct uio
*uio
, int linktype
, struct mbuf
**mp
,
148 struct sockaddr
*sockp
, int *datlen
, struct bpf_insn
*wfilter
)
160 * Build a sockaddr based on the data link layer type.
161 * We do this at this level because the ethernet header
162 * is copied directly into the data field of the sockaddr.
163 * In the case of SLIP, there is no header and the packet
164 * is forwarded as is.
165 * Also, we are careful to leave room at the front of the mbuf
166 * for the link level header.
170 sockp
->sa_family
= AF_INET
;
175 sockp
->sa_family
= AF_UNSPEC
;
176 /* XXX Would MAXLINKHDR be better? */
177 hlen
= sizeof(struct ether_header
);
182 sockp
->sa_family
= AF_UNSPEC
;
186 case DLT_ATM_RFC1483
:
188 * en atm driver requires 4-byte atm pseudo header.
189 * though it isn't standard, vpi:vci needs to be
192 sockp
->sa_family
= AF_UNSPEC
;
193 hlen
= 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
197 sockp
->sa_family
= AF_UNSPEC
;
198 hlen
= 4; /* This should match PPP_HDRLEN */
205 len
= uio
->uio_resid
;
206 *datlen
= len
- hlen
;
207 if ((unsigned)len
> MCLBYTES
)
210 m
= m_getl(len
, MB_WAIT
, MT_DATA
, M_PKTHDR
, NULL
);
213 m
->m_pkthdr
.len
= m
->m_len
= len
;
214 m
->m_pkthdr
.rcvif
= NULL
;
217 if (m
->m_len
< hlen
) {
222 error
= uiomove(mtod(m
, u_char
*), len
, uio
);
226 slen
= bpf_filter(wfilter
, mtod(m
, u_char
*), len
, len
);
233 * Make room for link header, and copy it to sockaddr.
236 bcopy(m
->m_data
, sockp
->sa_data
, hlen
);
237 m
->m_pkthdr
.len
-= hlen
;
239 m
->m_data
+= hlen
; /* XXX */
248 * Attach file to the bpf interface, i.e. make d listen on bp.
249 * Must be called at splimp.
252 bpf_attachd(struct bpf_d
*d
, struct bpf_if
*bp
)
255 * Point d at bp, and add d to the interface's list of listeners.
256 * Finally, point the driver's bpf cookie at the interface so
257 * it will divert packets to bpf.
260 SLIST_INSERT_HEAD(&bp
->bif_dlist
, d
, bd_next
);
261 *bp
->bif_driverp
= bp
;
265 * Detach a file from its interface.
268 bpf_detachd(struct bpf_d
*d
)
277 /* Remove d from the interface's descriptor list. */
278 SLIST_REMOVE(&bp
->bif_dlist
, d
, bpf_d
, bd_next
);
280 if (SLIST_EMPTY(&bp
->bif_dlist
)) {
282 * Let the driver know that there are no more listeners.
284 *bp
->bif_driverp
= NULL
;
288 * Check if this descriptor had requested promiscuous mode.
289 * If so, turn it off.
293 error
= ifpromisc(ifp
, 0);
294 if (error
!= 0 && error
!= ENXIO
) {
296 * ENXIO can happen if a pccard is unplugged,
297 * Something is really wrong if we were able to put
298 * the driver into promiscuous mode, but can't
301 if_printf(ifp
, "bpf_detach: ifpromisc failed(%d)\n",
308 * Open ethernet device. Returns ENXIO for illegal minor device number,
309 * EBUSY if file is open by another process.
313 bpfopen(struct dev_open_args
*ap
)
315 cdev_t dev
= ap
->a_head
.a_dev
;
318 if (ap
->a_cred
->cr_prison
)
323 * Each minor can be opened by only one process. If the requested
324 * minor is in use, return EBUSY.
329 MALLOC(d
, struct bpf_d
*, sizeof *d
, M_BPF
, M_WAITOK
| M_ZERO
);
331 d
->bd_bufsize
= bpf_bufsize
;
334 callout_init(&d
->bd_callout
);
339 bpfclone(struct dev_clone_args
*ap
)
343 unit
= devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf
), 0);
344 ap
->a_dev
= make_only_dev(&bpf_ops
, unit
, 0, 0, 0600, "bpf%d", unit
);
350 * Close the descriptor by detaching it from its interface,
351 * deallocating its buffers, and marking it free.
355 bpfclose(struct dev_close_args
*ap
)
357 cdev_t dev
= ap
->a_head
.a_dev
;
358 struct bpf_d
*d
= dev
->si_drv1
;
360 funsetown(d
->bd_sigio
);
362 if (d
->bd_state
== BPF_WAITING
)
363 callout_stop(&d
->bd_callout
);
364 d
->bd_state
= BPF_IDLE
;
365 if (d
->bd_bif
!= NULL
)
370 if (dev
->si_uminor
>= BPF_PREALLOCATED_UNITS
) {
371 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf
), dev
->si_uminor
);
379 * Rotate the packet buffers in descriptor d. Move the store buffer
380 * into the hold slot, and the free buffer into the store slot.
381 * Zero the length of the new store buffer.
383 #define ROTATE_BUFFERS(d) \
384 (d)->bd_hbuf = (d)->bd_sbuf; \
385 (d)->bd_hlen = (d)->bd_slen; \
386 (d)->bd_sbuf = (d)->bd_fbuf; \
390 * bpfread - read next chunk of packets from buffers
393 bpfread(struct dev_read_args
*ap
)
395 cdev_t dev
= ap
->a_head
.a_dev
;
396 struct bpf_d
*d
= dev
->si_drv1
;
401 * Restrict application to use a buffer the same size as
404 if (ap
->a_uio
->uio_resid
!= d
->bd_bufsize
)
408 if (d
->bd_state
== BPF_WAITING
)
409 callout_stop(&d
->bd_callout
);
410 timed_out
= (d
->bd_state
== BPF_TIMED_OUT
);
411 d
->bd_state
= BPF_IDLE
;
413 * If the hold buffer is empty, then do a timed sleep, which
414 * ends when the timeout expires or when enough packets
415 * have arrived to fill the store buffer.
417 while (d
->bd_hbuf
== NULL
) {
418 if ((d
->bd_immediate
|| timed_out
) && d
->bd_slen
!= 0) {
420 * A packet(s) either arrived since the previous
421 * read or arrived while we were asleep.
422 * Rotate the buffers and return what's here.
429 * No data is available, check to see if the bpf device
430 * is still pointed at a real interface. If not, return
431 * ENXIO so that the userland process knows to rebind
432 * it before using it again.
434 if (d
->bd_bif
== NULL
) {
439 if (ap
->a_ioflag
& IO_NDELAY
) {
443 error
= tsleep(d
, PCATCH
, "bpf", d
->bd_rtout
);
444 if (error
== EINTR
|| error
== ERESTART
) {
448 if (error
== EWOULDBLOCK
) {
450 * On a timeout, return what's in the buffer,
451 * which may be nothing. If there is something
452 * in the store buffer, we can rotate the buffers.
456 * We filled up the buffer in between
457 * getting the timeout and arriving
458 * here, so we don't need to rotate.
462 if (d
->bd_slen
== 0) {
471 * At this point, we know we have something in the hold slot.
476 * Move data from hold buffer into user space.
477 * We know the entire buffer is transferred since
478 * we checked above that the read buffer is bpf_bufsize bytes.
480 error
= uiomove(d
->bd_hbuf
, d
->bd_hlen
, ap
->a_uio
);
483 d
->bd_fbuf
= d
->bd_hbuf
;
493 * If there are processes sleeping on this descriptor, wake them up.
496 bpf_wakeup(struct bpf_d
*d
)
498 if (d
->bd_state
== BPF_WAITING
) {
499 callout_stop(&d
->bd_callout
);
500 d
->bd_state
= BPF_IDLE
;
503 if (d
->bd_async
&& d
->bd_sig
&& d
->bd_sigio
)
504 pgsigio(d
->bd_sigio
, d
->bd_sig
, 0);
507 selwakeup(&d
->bd_sel
);
510 d
->bd_sel
.si_pid
= 0;
514 bpf_timed_out(void *arg
)
516 struct bpf_d
*d
= (struct bpf_d
*)arg
;
519 if (d
->bd_state
== BPF_WAITING
) {
520 d
->bd_state
= BPF_TIMED_OUT
;
528 bpf_output_dispatch(struct netmsg
*nmsg
)
530 struct netmsg_bpf_output
*bmsg
= (struct netmsg_bpf_output
*)nmsg
;
531 struct ifnet
*ifp
= bmsg
->nm_ifp
;
535 * The driver frees the mbuf.
537 error
= ifp
->if_output(ifp
, bmsg
->nm_mbuf
, bmsg
->nm_dst
, NULL
);
538 lwkt_replymsg(&nmsg
->nm_lmsg
, error
);
542 bpfwrite(struct dev_write_args
*ap
)
544 cdev_t dev
= ap
->a_head
.a_dev
;
545 struct bpf_d
*d
= dev
->si_drv1
;
551 struct netmsg_bpf_output bmsg
;
553 if (d
->bd_bif
== NULL
)
556 ifp
= d
->bd_bif
->bif_ifp
;
558 if (ap
->a_uio
->uio_resid
== 0)
561 error
= bpf_movein(ap
->a_uio
, (int)d
->bd_bif
->bif_dlt
, &m
,
562 &dst
, &datlen
, d
->bd_wfilter
);
566 if (datlen
> ifp
->if_mtu
) {
572 dst
.sa_family
= pseudo_AF_HDRCMPLT
;
574 netmsg_init(&bmsg
.nm_netmsg
, &curthread
->td_msgport
, MSGF_MPSAFE
,
575 bpf_output_dispatch
);
580 return lwkt_domsg(cpu_portfn(0), &bmsg
.nm_netmsg
.nm_lmsg
, 0);
584 * Reset a descriptor by flushing its packet buffer and clearing the
585 * receive and drop counts. Should be called at splimp.
588 bpf_resetd(struct bpf_d
*d
)
591 /* Free the hold buffer. */
592 d
->bd_fbuf
= d
->bd_hbuf
;
602 * FIONREAD Check for read packet available.
603 * SIOCGIFADDR Get interface address - convenient hook to driver.
604 * BIOCGBLEN Get buffer len [for read()].
605 * BIOCSETF Set ethernet read filter.
606 * BIOCSETWF Set ethernet write filter.
607 * BIOCFLUSH Flush read packet buffer.
608 * BIOCPROMISC Put interface into promiscuous mode.
609 * BIOCGDLT Get link layer type.
610 * BIOCGETIF Get interface name.
611 * BIOCSETIF Set interface.
612 * BIOCSRTIMEOUT Set read timeout.
613 * BIOCGRTIMEOUT Get read timeout.
614 * BIOCGSTATS Get packet stats.
615 * BIOCIMMEDIATE Set immediate mode.
616 * BIOCVERSION Get filter language version.
617 * BIOCGHDRCMPLT Get "header already complete" flag
618 * BIOCSHDRCMPLT Set "header already complete" flag
619 * BIOCGSEESENT Get "see packets sent" flag
620 * BIOCSSEESENT Set "see packets sent" flag
621 * BIOCLOCK Set "locked" flag
625 bpfioctl(struct dev_ioctl_args
*ap
)
627 cdev_t dev
= ap
->a_head
.a_dev
;
628 struct bpf_d
*d
= dev
->si_drv1
;
632 if (d
->bd_state
== BPF_WAITING
)
633 callout_stop(&d
->bd_callout
);
634 d
->bd_state
= BPF_IDLE
;
637 if (d
->bd_locked
== 1) {
665 * Check for read packet available.
677 *(int *)ap
->a_data
= n
;
685 if (d
->bd_bif
== NULL
) {
688 ifp
= d
->bd_bif
->bif_ifp
;
689 ifnet_serialize_all(ifp
);
690 error
= ifp
->if_ioctl(ifp
, ap
->a_cmd
,
691 ap
->a_data
, ap
->a_cred
);
692 ifnet_deserialize_all(ifp
);
698 * Get buffer len [for read()].
701 *(u_int
*)ap
->a_data
= d
->bd_bufsize
;
708 if (d
->bd_bif
!= NULL
) {
711 u_int size
= *(u_int
*)ap
->a_data
;
713 if (size
> bpf_maxbufsize
)
714 *(u_int
*)ap
->a_data
= size
= bpf_maxbufsize
;
715 else if (size
< BPF_MINBUFSIZE
)
716 *(u_int
*)ap
->a_data
= size
= BPF_MINBUFSIZE
;
717 d
->bd_bufsize
= size
;
722 * Set link layer read filter.
726 error
= bpf_setf(d
, (struct bpf_program
*)ap
->a_data
,
731 * Flush read packet buffer.
740 * Put interface into promiscuous mode.
743 if (d
->bd_bif
== NULL
) {
745 * No interface attached yet.
751 if (d
->bd_promisc
== 0) {
752 error
= ifpromisc(d
->bd_bif
->bif_ifp
, 1);
760 * Get device parameters.
763 if (d
->bd_bif
== NULL
)
766 *(u_int
*)ap
->a_data
= d
->bd_bif
->bif_dlt
;
770 * Get a list of supported data link types.
773 if (d
->bd_bif
== NULL
) {
776 error
= bpf_getdltlist(d
,
777 (struct bpf_dltlist
*)ap
->a_data
);
782 * Set data link type.
785 if (d
->bd_bif
== NULL
)
788 error
= bpf_setdlt(d
, *(u_int
*)ap
->a_data
);
792 * Get interface name.
795 if (d
->bd_bif
== NULL
) {
798 struct ifnet
*const ifp
= d
->bd_bif
->bif_ifp
;
799 struct ifreq
*const ifr
= (struct ifreq
*)ap
->a_data
;
801 strlcpy(ifr
->ifr_name
, ifp
->if_xname
,
802 sizeof ifr
->ifr_name
);
810 error
= bpf_setif(d
, (struct ifreq
*)ap
->a_data
);
818 struct timeval
*tv
= (struct timeval
*)ap
->a_data
;
821 * Subtract 1 tick from tvtohz() since this isn't
824 if ((error
= itimerfix(tv
)) == 0)
825 d
->bd_rtout
= tvtohz_low(tv
);
834 struct timeval
*tv
= (struct timeval
*)ap
->a_data
;
836 tv
->tv_sec
= d
->bd_rtout
/ hz
;
837 tv
->tv_usec
= (d
->bd_rtout
% hz
) * tick
;
846 struct bpf_stat
*bs
= (struct bpf_stat
*)ap
->a_data
;
848 bs
->bs_recv
= d
->bd_rcount
;
849 bs
->bs_drop
= d
->bd_dcount
;
854 * Set immediate mode.
857 d
->bd_immediate
= *(u_int
*)ap
->a_data
;
862 struct bpf_version
*bv
= (struct bpf_version
*)ap
->a_data
;
864 bv
->bv_major
= BPF_MAJOR_VERSION
;
865 bv
->bv_minor
= BPF_MINOR_VERSION
;
870 * Get "header already complete" flag
873 *(u_int
*)ap
->a_data
= d
->bd_hdrcmplt
;
877 * Set "header already complete" flag
880 d
->bd_hdrcmplt
= *(u_int
*)ap
->a_data
? 1 : 0;
884 * Get "see sent packets" flag
887 *(u_int
*)ap
->a_data
= d
->bd_seesent
;
891 * Set "see sent packets" flag
894 d
->bd_seesent
= *(u_int
*)ap
->a_data
;
897 case FIOASYNC
: /* Send signal on receive packets */
898 d
->bd_async
= *(int *)ap
->a_data
;
902 error
= fsetown(*(int *)ap
->a_data
, &d
->bd_sigio
);
906 *(int *)ap
->a_data
= fgetown(d
->bd_sigio
);
909 /* This is deprecated, FIOSETOWN should be used instead. */
911 error
= fsetown(-(*(int *)ap
->a_data
), &d
->bd_sigio
);
914 /* This is deprecated, FIOGETOWN should be used instead. */
916 *(int *)ap
->a_data
= -fgetown(d
->bd_sigio
);
919 case BIOCSRSIG
: /* Set receive signal */
923 sig
= *(u_int
*)ap
->a_data
;
932 *(u_int
*)ap
->a_data
= d
->bd_sig
;
942 * Set d's packet filter program to fp. If this file already has a filter,
943 * free it and replace it. Returns EINVAL for bogus requests.
946 bpf_setf(struct bpf_d
*d
, struct bpf_program
*fp
, u_long cmd
)
948 struct bpf_insn
*fcode
, *old
;
949 u_int wfilter
, flen
, size
;
951 if (cmd
== BIOCSETWF
) {
958 if (fp
->bf_insns
== NULL
) {
963 d
->bd_wfilter
= NULL
;
965 d
->bd_rfilter
= NULL
;
973 if (flen
> BPF_MAXINSNS
)
976 size
= flen
* sizeof *fp
->bf_insns
;
977 fcode
= (struct bpf_insn
*)kmalloc(size
, M_BPF
, M_WAITOK
);
978 if (copyin(fp
->bf_insns
, fcode
, size
) == 0 &&
979 bpf_validate(fcode
, (int)flen
)) {
982 d
->bd_wfilter
= fcode
;
984 d
->bd_rfilter
= fcode
;
997 * Detach a file from its current interface (if attached at all) and attach
998 * to the interface indicated by the name stored in ifr.
999 * Return an errno or 0.
1002 bpf_setif(struct bpf_d
*d
, struct ifreq
*ifr
)
1006 struct ifnet
*theywant
;
1008 theywant
= ifunit(ifr
->ifr_name
);
1009 if (theywant
== NULL
)
1013 * Look through attached interfaces for the named one.
1015 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1016 struct ifnet
*ifp
= bp
->bif_ifp
;
1018 if (ifp
== NULL
|| ifp
!= theywant
)
1020 /* skip additional entry */
1021 if (bp
->bif_driverp
!= &ifp
->if_bpf
)
1024 * We found the requested interface.
1025 * If it's not up, return an error.
1026 * Allocate the packet buffers if we need to.
1027 * If we're already attached to requested interface,
1028 * just flush the buffer.
1030 if (!(ifp
->if_flags
& IFF_UP
))
1033 if (d
->bd_sbuf
== NULL
) {
1034 error
= bpf_allocbufs(d
);
1039 if (bp
!= d
->bd_bif
) {
1040 if (d
->bd_bif
!= NULL
) {
1042 * Detach if attached to something else.
1059 * Support for select() and poll() system calls
1061 * Return true iff the specific operation will not block indefinitely.
1062 * Otherwise, return false but make a note that a selwakeup() must be done.
1065 bpfpoll(struct dev_poll_args
*ap
)
1067 cdev_t dev
= ap
->a_head
.a_dev
;
1072 if (d
->bd_bif
== NULL
)
1075 revents
= ap
->a_events
& (POLLOUT
| POLLWRNORM
);
1077 if (ap
->a_events
& (POLLIN
| POLLRDNORM
)) {
1079 * An imitation of the FIONREAD ioctl code.
1080 * XXX not quite. An exact imitation:
1081 * if (d->b_slen != 0 ||
1082 * (d->bd_hbuf != NULL && d->bd_hlen != 0)
1084 if (d
->bd_hlen
!= 0 ||
1085 ((d
->bd_immediate
|| d
->bd_state
== BPF_TIMED_OUT
) &&
1087 revents
|= ap
->a_events
& (POLLIN
| POLLRDNORM
);
1089 selrecord(curthread
, &d
->bd_sel
);
1090 /* Start the read timeout if necessary. */
1091 if (d
->bd_rtout
> 0 && d
->bd_state
== BPF_IDLE
) {
1092 callout_reset(&d
->bd_callout
, d
->bd_rtout
,
1094 d
->bd_state
= BPF_WAITING
;
1099 ap
->a_events
= revents
;
1104 * Process the packet pkt of length pktlen. The packet is parsed
1105 * by each listener's filter, and if accepted, stashed into the
1106 * corresponding buffer.
1109 bpf_tap(struct bpf_if
*bp
, u_char
*pkt
, u_int pktlen
)
1125 * Note that the ipl does not have to be raised at this point.
1126 * The only problem that could arise here is that if two different
1127 * interfaces shared any data. This is not the case.
1129 SLIST_FOREACH(d
, &bp
->bif_dlist
, bd_next
) {
1131 slen
= bpf_filter(d
->bd_rfilter
, pkt
, pktlen
, pktlen
);
1137 catchpacket(d
, pkt
, pktlen
, slen
, ovbcopy
, &tv
);
1145 * Copy data from an mbuf chain into a buffer. This code is derived
1146 * from m_copydata in sys/uipc_mbuf.c.
1149 bpf_mcopy(const void *src_arg
, void *dst_arg
, size_t len
)
1151 const struct mbuf
*m
;
1160 count
= min(m
->m_len
, len
);
1161 bcopy(mtod(m
, void *), dst
, count
);
1169 * Process the packet in the mbuf chain m. The packet is parsed by each
1170 * listener's filter, and if accepted, stashed into the corresponding
1174 bpf_mtap(struct bpf_if
*bp
, struct mbuf
*m
)
1189 /* Don't compute pktlen, if no descriptor is attached. */
1190 if (SLIST_EMPTY(&bp
->bif_dlist
)) {
1195 pktlen
= m_lengthm(m
, NULL
);
1197 SLIST_FOREACH(d
, &bp
->bif_dlist
, bd_next
) {
1198 if (!d
->bd_seesent
&& (m
->m_pkthdr
.rcvif
== NULL
))
1201 slen
= bpf_filter(d
->bd_rfilter
, (u_char
*)m
, pktlen
, 0);
1207 catchpacket(d
, (u_char
*)m
, pktlen
, slen
, bpf_mcopy
,
1216 bpf_mtap_family(struct bpf_if
*bp
, struct mbuf
*m
, sa_family_t family
)
1220 KKASSERT(family
!= AF_UNSPEC
);
1222 family4
= (u_int
)family
;
1223 bpf_ptap(bp
, m
, &family4
, sizeof(family4
));
1227 * Process the packet in the mbuf chain m with the header in m prepended.
1228 * The packet is parsed by each listener's filter, and if accepted,
1229 * stashed into the corresponding buffer.
1232 bpf_ptap(struct bpf_if
*bp
, struct mbuf
*m
, const void *data
, u_int dlen
)
1237 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1238 * Note that we cut corners here; we only setup what's
1239 * absolutely needed--this mbuf should never go anywhere else.
1242 mb
.m_data
= __DECONST(void *, data
); /* LINTED */
1244 mb
.m_pkthdr
.rcvif
= m
->m_pkthdr
.rcvif
;
1250 * Move the packet data from interface memory (pkt) into the
1251 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1252 * otherwise 0. "copy" is the routine called to do the actual data
1253 * transfer. bcopy is passed in to copy contiguous chunks, while
1254 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1255 * pkt is really an mbuf.
1258 catchpacket(struct bpf_d
*d
, u_char
*pkt
, u_int pktlen
, u_int snaplen
,
1259 void (*cpfn
)(const void *, void *, size_t),
1260 const struct timeval
*tv
)
1264 int hdrlen
= d
->bd_bif
->bif_hdrlen
;
1266 * Figure out how many bytes to move. If the packet is
1267 * greater or equal to the snapshot length, transfer that
1268 * much. Otherwise, transfer the whole packet (unless
1269 * we hit the buffer size limit).
1271 totlen
= hdrlen
+ min(snaplen
, pktlen
);
1272 if (totlen
> d
->bd_bufsize
)
1273 totlen
= d
->bd_bufsize
;
1276 * Round up the end of the previous packet to the next longword.
1278 curlen
= BPF_WORDALIGN(d
->bd_slen
);
1279 if (curlen
+ totlen
> d
->bd_bufsize
) {
1281 * This packet will overflow the storage buffer.
1282 * Rotate the buffers if we can, then wakeup any
1285 if (d
->bd_fbuf
== NULL
) {
1287 * We haven't completed the previous read yet,
1288 * so drop the packet.
1296 } else if (d
->bd_immediate
|| d
->bd_state
== BPF_TIMED_OUT
) {
1298 * Immediate mode is set, or the read timeout has
1299 * already expired during a select call. A packet
1300 * arrived, so the reader should be woken up.
1306 * Append the bpf header.
1308 hp
= (struct bpf_hdr
*)(d
->bd_sbuf
+ curlen
);
1309 hp
->bh_tstamp
= *tv
;
1310 hp
->bh_datalen
= pktlen
;
1311 hp
->bh_hdrlen
= hdrlen
;
1313 * Copy the packet data into the store buffer and update its length.
1315 (*cpfn
)(pkt
, (u_char
*)hp
+ hdrlen
, (hp
->bh_caplen
= totlen
- hdrlen
));
1316 d
->bd_slen
= curlen
+ totlen
;
1320 * Initialize all nonzero fields of a descriptor.
1323 bpf_allocbufs(struct bpf_d
*d
)
1325 d
->bd_fbuf
= kmalloc(d
->bd_bufsize
, M_BPF
, M_WAITOK
);
1326 d
->bd_sbuf
= kmalloc(d
->bd_bufsize
, M_BPF
, M_WAITOK
);
1333 * Free buffers and packet filter program currently in use by a descriptor.
1337 bpf_freed(struct bpf_d
*d
)
1340 * We don't need to lock out interrupts since this descriptor has
1341 * been detached from its interface and it yet hasn't been marked
1344 if (d
->bd_sbuf
!= NULL
) {
1345 kfree(d
->bd_sbuf
, M_BPF
);
1346 if (d
->bd_hbuf
!= NULL
)
1347 kfree(d
->bd_hbuf
, M_BPF
);
1348 if (d
->bd_fbuf
!= NULL
)
1349 kfree(d
->bd_fbuf
, M_BPF
);
1352 kfree(d
->bd_rfilter
, M_BPF
);
1354 kfree(d
->bd_wfilter
, M_BPF
);
1358 * Attach an interface to bpf. ifp is a pointer to the structure
1359 * defining the interface to be attached, dlt is the link layer type,
1360 * and hdrlen is the fixed size of the link header (variable length
1361 * headers are not yet supported).
1364 bpfattach(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
)
1366 bpfattach_dlt(ifp
, dlt
, hdrlen
, &ifp
->if_bpf
);
1370 bpfattach_dlt(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
, struct bpf_if
**driverp
)
1374 bp
= kmalloc(sizeof *bp
, M_BPF
, M_WAITOK
| M_ZERO
);
1376 SLIST_INIT(&bp
->bif_dlist
);
1379 bp
->bif_driverp
= driverp
;
1380 *bp
->bif_driverp
= NULL
;
1382 bp
->bif_next
= bpf_iflist
;
1386 * Compute the length of the bpf header. This is not necessarily
1387 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1388 * that the network layer header begins on a longword boundary (for
1389 * performance reasons and to alleviate alignment restrictions).
1391 bp
->bif_hdrlen
= BPF_WORDALIGN(hdrlen
+ SIZEOF_BPF_HDR
) - hdrlen
;
1394 if_printf(ifp
, "bpf attached\n");
1398 * Detach bpf from an interface. This involves detaching each descriptor
1399 * associated with the interface, and leaving bd_bif NULL. Notify each
1400 * descriptor as it's detached so that any sleepers wake up and get
1404 bpfdetach(struct ifnet
*ifp
)
1406 struct bpf_if
*bp
, *bp_prev
;
1411 /* Locate BPF interface information */
1413 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1414 if (ifp
== bp
->bif_ifp
)
1419 /* Interface wasn't attached */
1420 if (bp
->bif_ifp
== NULL
) {
1422 kprintf("bpfdetach: %s was not attached\n", ifp
->if_xname
);
1426 while ((d
= SLIST_FIRST(&bp
->bif_dlist
)) != NULL
) {
1431 if (bp_prev
!= NULL
)
1432 bp_prev
->bif_next
= bp
->bif_next
;
1434 bpf_iflist
= bp
->bif_next
;
1442 * Get a list of available data link type of the interface.
1445 bpf_getdltlist(struct bpf_d
*d
, struct bpf_dltlist
*bfl
)
1451 ifp
= d
->bd_bif
->bif_ifp
;
1454 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1455 if (bp
->bif_ifp
!= ifp
)
1457 if (bfl
->bfl_list
!= NULL
) {
1458 if (n
>= bfl
->bfl_len
) {
1461 error
= copyout(&bp
->bif_dlt
,
1462 bfl
->bfl_list
+ n
, sizeof(u_int
));
1471 * Set the data link type of a BPF instance.
1474 bpf_setdlt(struct bpf_d
*d
, u_int dlt
)
1476 int error
, opromisc
;
1480 if (d
->bd_bif
->bif_dlt
== dlt
)
1482 ifp
= d
->bd_bif
->bif_ifp
;
1483 for (bp
= bpf_iflist
; bp
!= NULL
; bp
= bp
->bif_next
) {
1484 if (bp
->bif_ifp
== ifp
&& bp
->bif_dlt
== dlt
)
1488 opromisc
= d
->bd_promisc
;
1494 error
= ifpromisc(bp
->bif_ifp
, 1);
1496 if_printf(bp
->bif_ifp
,
1497 "bpf_setdlt: ifpromisc failed (%d)\n",
1505 return(bp
== NULL
? EINVAL
: 0);
1509 bpf_drvinit(void *unused
)
1513 make_autoclone_dev(&bpf_ops
, &DEVFS_CLONE_BITMAP(bpf
),
1514 bpfclone
, 0, 0, 0600, "bpf");
1515 for (i
= 0; i
< BPF_PREALLOCATED_UNITS
; i
++) {
1516 make_dev(&bpf_ops
, i
, 0, 0, 0600, "bpf%d", i
);
1517 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf
), i
);
1522 bpf_drvuninit(void *unused
)
1524 devfs_clone_handler_del("bpf");
1525 dev_ops_remove_all(&bpf_ops
);
1526 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf
));
1529 SYSINIT(bpfdev
,SI_SUB_DRIVERS
,SI_ORDER_MIDDLE
+CDEV_MAJOR
,bpf_drvinit
,NULL
)
1530 SYSUNINIT(bpfdev
, SI_SUB_DRIVERS
,SI_ORDER_MIDDLE
+CDEV_MAJOR
,bpf_drvuninit
, NULL
);
1534 * NOP stubs to allow bpf-using drivers to load and function.
1536 * A 'better' implementation would allow the core bpf functionality
1537 * to be loaded at runtime.
1541 bpf_tap(struct bpf_if
*bp
, u_char
*pkt
, u_int pktlen
)
1546 bpf_mtap(struct bpf_if
*bp
, struct mbuf
*m
)
1551 bpf_ptap(struct bpf_if
*bp
, struct mbuf
*m
, const void *data
, u_int dlen
)
1556 bpfattach(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
)
1561 bpfattach_dlt(struct ifnet
*ifp
, u_int dlt
, u_int hdrlen
, struct bpf_if
**driverp
)
1566 bpfdetach(struct ifnet
*ifp
)
1571 bpf_filter(const struct bpf_insn
*pc
, u_char
*p
, u_int wirelen
, u_int buflen
)
1573 return -1; /* "no filter" behaviour */