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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#)bpf.c 8.2 (Berkeley) 3/28/94
36 * $FreeBSD: src/sys/net/bpf.c,v 1.59.2.12 2002/04/14 21:41:48 luigi Exp $
41 #include <sys/param.h>
42 #include <sys/systm.h>
45 #include <sys/device.h>
46 #include <sys/malloc.h>
50 #include <sys/signalvar.h>
51 #include <sys/filio.h>
52 #include <sys/sockio.h>
53 #include <sys/ttycom.h>
54 #include <sys/filedesc.h>
56 #include <sys/event.h>
58 #include <sys/socket.h>
59 #include <sys/vnode.h>
63 #include <net/bpfdesc.h>
64 #include <net/netmsg2.h>
65 #include <net/netisr2.h>
67 #include <netinet/in.h>
68 #include <netinet/if_ether.h>
69 #include <sys/kernel.h>
70 #include <sys/sysctl.h>
72 #include <netproto/802_11/ieee80211_dragonfly.h>
74 #include <sys/devfs.h>
76 struct netmsg_bpf_output {
77 struct netmsg_base base;
80 struct sockaddr *nm_dst;
81 boolean_t nm_feedback;
84 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
85 DEVFS_DEFINE_CLONE_BITMAP(bpf);
88 #define BPF_PREALLOCATED_UNITS 4
90 #define BPF_PREALLOCATED_UNITS NBPF
96 * The default read buffer size is patchable.
98 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
99 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
100 &bpf_bufsize, 0, "Current size of bpf buffer");
101 int bpf_maxbufsize = BPF_MAXBUFSIZE;
102 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
103 &bpf_maxbufsize, 0, "Maximum size of bpf buffer");
106 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
108 static struct bpf_if *bpf_iflist;
110 static struct lwkt_token bpf_token = LWKT_TOKEN_INITIALIZER(bpf_token);
112 static int bpf_allocbufs(struct bpf_d *);
113 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
114 static void bpf_detachd(struct bpf_d *d);
115 static void bpf_resetd(struct bpf_d *);
116 static void bpf_freed(struct bpf_d *);
117 static void bpf_mcopy(volatile const void *, volatile void *, size_t);
118 static int bpf_movein(struct uio *, int, struct mbuf **,
119 struct sockaddr *, int *, struct bpf_insn *);
120 static int bpf_setif(struct bpf_d *, struct ifreq *);
121 static void bpf_timed_out(void *);
122 static void bpf_wakeup(struct bpf_d *);
123 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
124 void (*)(volatile const void *,
125 volatile void *, size_t),
126 const struct timeval *);
127 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
128 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
129 static int bpf_setdlt(struct bpf_d *, u_int);
130 static void bpf_drvinit(void *unused);
131 static void bpf_filter_detach(struct knote *kn);
132 static int bpf_filter_read(struct knote *kn, long hint);
134 static d_open_t bpfopen;
135 static d_clone_t bpfclone;
136 static d_close_t bpfclose;
137 static d_read_t bpfread;
138 static d_write_t bpfwrite;
139 static d_ioctl_t bpfioctl;
140 static d_kqfilter_t bpfkqfilter;
142 #define CDEV_MAJOR 23
143 static struct dev_ops bpf_ops = {
144 { "bpf", 0, D_MPSAFE },
150 .d_kqfilter = bpfkqfilter
155 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
156 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
158 const struct ieee80211_bpf_params *p;
169 * Build a sockaddr based on the data link layer type.
170 * We do this at this level because the ethernet header
171 * is copied directly into the data field of the sockaddr.
172 * In the case of SLIP, there is no header and the packet
173 * is forwarded as is.
174 * Also, we are careful to leave room at the front of the mbuf
175 * for the link level header.
179 sockp->sa_family = AF_INET;
184 sockp->sa_family = AF_UNSPEC;
185 /* XXX Would MAXLINKHDR be better? */
186 hlen = sizeof(struct ether_header);
191 sockp->sa_family = AF_UNSPEC;
195 case DLT_ATM_RFC1483:
197 * en atm driver requires 4-byte atm pseudo header.
198 * though it isn't standard, vpi:vci needs to be
201 sockp->sa_family = AF_UNSPEC;
202 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
206 sockp->sa_family = AF_UNSPEC;
207 hlen = 4; /* This should match PPP_HDRLEN */
210 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
211 sockp->sa_family = AF_IEEE80211;
215 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
216 sockp->sa_family = AF_IEEE80211;
217 sockp->sa_len = 12; /* XXX != 0 */
218 hlen = sizeof(struct ieee80211_bpf_params);
225 len = uio->uio_resid;
226 *datlen = len - hlen;
227 if ((unsigned)len > MCLBYTES)
230 m = m_getl(len, M_WAITOK, MT_DATA, M_PKTHDR, NULL);
233 m->m_pkthdr.len = m->m_len = len;
234 m->m_pkthdr.rcvif = NULL;
237 if (m->m_len < hlen) {
242 error = uiomove(mtod(m, u_char *), len, uio);
246 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
253 * Make room for link header, and copy it to sockaddr.
256 if (sockp->sa_family == AF_IEEE80211) {
258 * Collect true length from the parameter header
259 * NB: sockp is known to be zero'd so if we do a
260 * short copy unspecified parameters will be
262 * NB: packet may not be aligned after stripping
266 p = mtod(m, const struct ieee80211_bpf_params *);
268 if (hlen > sizeof(sockp->sa_data)) {
273 bcopy(m->m_data, sockp->sa_data, hlen);
274 m->m_pkthdr.len -= hlen;
276 m->m_data += hlen; /* XXX */
285 * Attach file to the bpf interface, i.e. make d listen on bp.
286 * Must be called at splimp.
289 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
292 * Point d at bp, and add d to the interface's list of listeners.
293 * Finally, point the driver's bpf cookie at the interface so
294 * it will divert packets to bpf.
296 lwkt_gettoken(&bpf_token);
298 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
299 *bp->bif_driverp = bp;
301 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
302 lwkt_reltoken(&bpf_token);
306 * Detach a file from its interface.
309 bpf_detachd(struct bpf_d *d)
315 lwkt_gettoken(&bpf_token);
319 /* Remove d from the interface's descriptor list. */
320 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
322 if (SLIST_EMPTY(&bp->bif_dlist)) {
324 * Let the driver know that there are no more listeners.
326 *bp->bif_driverp = NULL;
330 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
333 * Check if this descriptor had requested promiscuous mode.
334 * If so, turn it off.
338 error = ifpromisc(ifp, 0);
339 if (error != 0 && error != ENXIO) {
341 * ENXIO can happen if a pccard is unplugged,
342 * Something is really wrong if we were able to put
343 * the driver into promiscuous mode, but can't
346 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
350 lwkt_reltoken(&bpf_token);
354 * Open ethernet device. Returns ENXIO for illegal minor device number,
355 * EBUSY if file is open by another process.
359 bpfopen(struct dev_open_args *ap)
361 cdev_t dev = ap->a_head.a_dev;
364 lwkt_gettoken(&bpf_token);
365 if (ap->a_cred->cr_prison) {
366 lwkt_reltoken(&bpf_token);
372 * Each minor can be opened by only one process. If the requested
373 * minor is in use, return EBUSY.
376 lwkt_reltoken(&bpf_token);
380 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
382 d->bd_bufsize = bpf_bufsize;
386 callout_init(&d->bd_callout);
387 lwkt_reltoken(&bpf_token);
393 bpfclone(struct dev_clone_args *ap)
397 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
398 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
404 * Close the descriptor by detaching it from its interface,
405 * deallocating its buffers, and marking it free.
409 bpfclose(struct dev_close_args *ap)
411 cdev_t dev = ap->a_head.a_dev;
412 struct bpf_d *d = dev->si_drv1;
415 lwkt_gettoken(&bpf_token);
416 funsetown(&d->bd_sigio);
417 if (d->bd_state == BPF_WAITING)
418 callout_stop(&d->bd_callout);
419 d->bd_state = BPF_IDLE;
420 if (d->bd_bif != NULL)
425 unit = dev->si_uminor;
426 if (unit >= BPF_PREALLOCATED_UNITS) {
428 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), unit);
431 lwkt_reltoken(&bpf_token);
437 * Rotate the packet buffers in descriptor d. Move the store buffer
438 * into the hold slot, and the free buffer into the store slot.
439 * Zero the length of the new store buffer.
441 #define ROTATE_BUFFERS(d) \
442 (d)->bd_hbuf = (d)->bd_sbuf; \
443 (d)->bd_hlen = (d)->bd_slen; \
444 (d)->bd_sbuf = (d)->bd_fbuf; \
448 * bpfread - read next chunk of packets from buffers
451 bpfread(struct dev_read_args *ap)
453 cdev_t dev = ap->a_head.a_dev;
454 struct bpf_d *d = dev->si_drv1;
458 lwkt_gettoken(&bpf_token);
460 * Restrict application to use a buffer the same size as
463 if (ap->a_uio->uio_resid != d->bd_bufsize) {
464 lwkt_reltoken(&bpf_token);
468 if (d->bd_state == BPF_WAITING)
469 callout_stop(&d->bd_callout);
470 timed_out = (d->bd_state == BPF_TIMED_OUT);
471 d->bd_state = BPF_IDLE;
473 * If the hold buffer is empty, then do a timed sleep, which
474 * ends when the timeout expires or when enough packets
475 * have arrived to fill the store buffer.
477 while (d->bd_hbuf == NULL) {
478 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
479 && d->bd_slen != 0) {
481 * A packet(s) either arrived since the previous,
482 * We're in immediate mode, or are reading
483 * in non-blocking mode, and a packet(s)
484 * either arrived since the previous
485 * read or arrived while we were asleep.
486 * Rotate the buffers and return what's here.
493 * No data is available, check to see if the bpf device
494 * is still pointed at a real interface. If not, return
495 * ENXIO so that the userland process knows to rebind
496 * it before using it again.
498 if (d->bd_bif == NULL) {
499 lwkt_reltoken(&bpf_token);
503 if (ap->a_ioflag & IO_NDELAY) {
504 lwkt_reltoken(&bpf_token);
507 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
508 if (error == EINTR || error == ERESTART) {
509 lwkt_reltoken(&bpf_token);
512 if (error == EWOULDBLOCK) {
514 * On a timeout, return what's in the buffer,
515 * which may be nothing. If there is something
516 * in the store buffer, we can rotate the buffers.
520 * We filled up the buffer in between
521 * getting the timeout and arriving
522 * here, so we don't need to rotate.
526 if (d->bd_slen == 0) {
527 lwkt_reltoken(&bpf_token);
535 * At this point, we know we have something in the hold slot.
539 * Move data from hold buffer into user space.
540 * We know the entire buffer is transferred since
541 * we checked above that the read buffer is bpf_bufsize bytes.
543 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
545 d->bd_fbuf = d->bd_hbuf;
548 lwkt_reltoken(&bpf_token);
555 * If there are processes sleeping on this descriptor, wake them up.
558 bpf_wakeup(struct bpf_d *d)
560 if (d->bd_state == BPF_WAITING) {
561 callout_stop(&d->bd_callout);
562 d->bd_state = BPF_IDLE;
565 if (d->bd_async && d->bd_sig && d->bd_sigio)
566 pgsigio(d->bd_sigio, d->bd_sig, 0);
568 KNOTE(&d->bd_kq.ki_note, 0);
572 bpf_timed_out(void *arg)
574 struct bpf_d *d = (struct bpf_d *)arg;
576 if (d->bd_state == BPF_WAITING) {
577 d->bd_state = BPF_TIMED_OUT;
584 bpf_output_dispatch(netmsg_t msg)
586 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
587 struct ifnet *ifp = bmsg->nm_ifp;
588 struct mbuf *mc = NULL;
591 if (bmsg->nm_feedback) {
592 mc = m_dup(bmsg->nm_mbuf, M_NOWAIT);
594 mc->m_pkthdr.rcvif = ifp;
598 * The driver frees the mbuf.
600 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
601 lwkt_replymsg(&msg->lmsg, error);
605 mc->m_flags &= ~M_HASH;
606 (*ifp->if_input)(ifp, mc, NULL, -1);
614 bpfwrite(struct dev_write_args *ap)
616 cdev_t dev = ap->a_head.a_dev;
617 struct bpf_d *d = dev->si_drv1;
623 struct netmsg_bpf_output bmsg;
625 lwkt_gettoken(&bpf_token);
626 if (d->bd_bif == NULL) {
627 lwkt_reltoken(&bpf_token);
631 ifp = d->bd_bif->bif_ifp;
633 if (ap->a_uio->uio_resid == 0) {
634 lwkt_reltoken(&bpf_token);
638 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
639 &dst, &datlen, d->bd_wfilter);
641 lwkt_reltoken(&bpf_token);
645 if (datlen > ifp->if_mtu) {
647 lwkt_reltoken(&bpf_token);
652 dst.sa_family = pseudo_AF_HDRCMPLT;
654 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
655 0, bpf_output_dispatch);
661 bmsg.nm_feedback = TRUE;
663 bmsg.nm_feedback = FALSE;
665 ret = lwkt_domsg(netisr_cpuport(0), &bmsg.base.lmsg, 0);
667 lwkt_reltoken(&bpf_token);
673 * Reset a descriptor by flushing its packet buffer and clearing the
674 * receive and drop counts. Should be called at splimp.
677 bpf_resetd(struct bpf_d *d)
680 /* Free the hold buffer. */
681 d->bd_fbuf = d->bd_hbuf;
691 * FIONREAD Check for read packet available.
692 * SIOCGIFADDR Get interface address - convenient hook to driver.
693 * BIOCGBLEN Get buffer len [for read()].
694 * BIOCSETF Set ethernet read filter.
695 * BIOCSETWF Set ethernet write filter.
696 * BIOCFLUSH Flush read packet buffer.
697 * BIOCPROMISC Put interface into promiscuous mode.
698 * BIOCGDLT Get link layer type.
699 * BIOCGETIF Get interface name.
700 * BIOCSETIF Set interface.
701 * BIOCSRTIMEOUT Set read timeout.
702 * BIOCGRTIMEOUT Get read timeout.
703 * BIOCGSTATS Get packet stats.
704 * BIOCIMMEDIATE Set immediate mode.
705 * BIOCVERSION Get filter language version.
706 * BIOCGHDRCMPLT Get "header already complete" flag
707 * BIOCSHDRCMPLT Set "header already complete" flag
708 * BIOCSFEEDBACK Set packet feedback mode.
709 * BIOCGFEEDBACK Get packet feedback mode.
710 * BIOCGSEESENT Get "see packets sent" flag
711 * BIOCSSEESENT Set "see packets sent" flag
712 * BIOCLOCK Set "locked" flag
716 bpfioctl(struct dev_ioctl_args *ap)
718 cdev_t dev = ap->a_head.a_dev;
719 struct bpf_d *d = dev->si_drv1;
722 lwkt_gettoken(&bpf_token);
723 if (d->bd_state == BPF_WAITING)
724 callout_stop(&d->bd_callout);
725 d->bd_state = BPF_IDLE;
727 if (d->bd_locked == 1) {
746 lwkt_reltoken(&bpf_token);
756 * Check for read packet available.
766 *(int *)ap->a_data = n;
774 if (d->bd_bif == NULL) {
777 ifp = d->bd_bif->bif_ifp;
778 ifnet_serialize_all(ifp);
779 error = ifp->if_ioctl(ifp, ap->a_cmd,
780 ap->a_data, ap->a_cred);
781 ifnet_deserialize_all(ifp);
787 * Get buffer len [for read()].
790 *(u_int *)ap->a_data = d->bd_bufsize;
797 if (d->bd_bif != NULL) {
800 u_int size = *(u_int *)ap->a_data;
802 if (size > bpf_maxbufsize)
803 *(u_int *)ap->a_data = size = bpf_maxbufsize;
804 else if (size < BPF_MINBUFSIZE)
805 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
806 d->bd_bufsize = size;
811 * Set link layer read filter.
815 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
820 * Flush read packet buffer.
827 * Put interface into promiscuous mode.
830 if (d->bd_bif == NULL) {
832 * No interface attached yet.
837 if (d->bd_promisc == 0) {
838 error = ifpromisc(d->bd_bif->bif_ifp, 1);
845 * Get device parameters.
848 if (d->bd_bif == NULL)
851 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
855 * Get a list of supported data link types.
858 if (d->bd_bif == NULL) {
861 error = bpf_getdltlist(d,
862 (struct bpf_dltlist *)ap->a_data);
867 * Set data link type.
870 if (d->bd_bif == NULL)
873 error = bpf_setdlt(d, *(u_int *)ap->a_data);
877 * Get interface name.
880 if (d->bd_bif == NULL) {
883 struct ifnet *const ifp = d->bd_bif->bif_ifp;
884 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
886 strlcpy(ifr->ifr_name, ifp->if_xname,
887 sizeof ifr->ifr_name);
895 error = bpf_setif(d, (struct ifreq *)ap->a_data);
903 struct timeval *tv = (struct timeval *)ap->a_data;
906 * Subtract 1 tick from tvtohz() since this isn't
909 if ((error = itimerfix(tv)) == 0)
910 d->bd_rtout = tvtohz_low(tv);
919 struct timeval *tv = (struct timeval *)ap->a_data;
921 tv->tv_sec = d->bd_rtout / hz;
922 tv->tv_usec = (d->bd_rtout % hz) * ustick;
931 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
933 bs->bs_recv = d->bd_rcount;
934 bs->bs_drop = d->bd_dcount;
939 * Set immediate mode.
942 d->bd_immediate = *(u_int *)ap->a_data;
947 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
949 bv->bv_major = BPF_MAJOR_VERSION;
950 bv->bv_minor = BPF_MINOR_VERSION;
955 * Get "header already complete" flag
958 *(u_int *)ap->a_data = d->bd_hdrcmplt;
962 * Set "header already complete" flag
965 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
969 * Get "see sent packets" flag
972 *(u_int *)ap->a_data = d->bd_seesent;
976 * Set "see sent packets" flag
979 d->bd_seesent = *(u_int *)ap->a_data;
982 case FIOASYNC: /* Send signal on receive packets */
983 d->bd_async = *(int *)ap->a_data;
987 * Set "feed packets from bpf back to input" mode
990 d->bd_feedback = *(int *)ap->a_data;
994 * Get "feed packets from bpf back to input" mode
997 *(u_int *)ap->a_data = d->bd_feedback;
1001 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
1005 *(int *)ap->a_data = fgetown(&d->bd_sigio);
1008 /* This is deprecated, FIOSETOWN should be used instead. */
1010 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
1013 /* This is deprecated, FIOGETOWN should be used instead. */
1015 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
1018 case BIOCSRSIG: /* Set receive signal */
1022 sig = *(u_int *)ap->a_data;
1031 *(u_int *)ap->a_data = d->bd_sig;
1037 lwkt_reltoken(&bpf_token);
1043 * Set d's packet filter program to fp. If this file already has a filter,
1044 * free it and replace it. Returns EINVAL for bogus requests.
1047 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1049 struct bpf_insn *fcode, *old;
1050 u_int wfilter, flen, size;
1052 if (cmd == BIOCSETWF) {
1053 old = d->bd_wfilter;
1057 old = d->bd_rfilter;
1059 if (fp->bf_insns == NULL) {
1060 if (fp->bf_len != 0)
1063 d->bd_wfilter = NULL;
1065 d->bd_rfilter = NULL;
1072 if (flen > BPF_MAXINSNS)
1075 size = flen * sizeof *fp->bf_insns;
1076 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
1077 if (copyin(fp->bf_insns, fcode, size) == 0 &&
1078 bpf_validate(fcode, (int)flen)) {
1080 d->bd_wfilter = fcode;
1082 d->bd_rfilter = fcode;
1089 kfree(fcode, M_BPF);
1094 * Detach a file from its current interface (if attached at all) and attach
1095 * to the interface indicated by the name stored in ifr.
1096 * Return an errno or 0.
1099 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1103 struct ifnet *theywant;
1107 theywant = ifunit(ifr->ifr_name);
1108 if (theywant == NULL) {
1114 * Look through attached interfaces for the named one.
1116 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1117 struct ifnet *ifp = bp->bif_ifp;
1119 if (ifp == NULL || ifp != theywant)
1121 /* skip additional entry */
1122 if (bp->bif_driverp != &ifp->if_bpf)
1125 * We found the requested interface.
1126 * Allocate the packet buffers if we need to.
1127 * If we're already attached to requested interface,
1128 * just flush the buffer.
1130 if (d->bd_sbuf == NULL) {
1131 error = bpf_allocbufs(d);
1137 if (bp != d->bd_bif) {
1138 if (d->bd_bif != NULL) {
1140 * Detach if attached to something else.
1159 static struct filterops bpf_read_filtops =
1160 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1163 bpfkqfilter(struct dev_kqfilter_args *ap)
1165 cdev_t dev = ap->a_head.a_dev;
1166 struct knote *kn = ap->a_kn;
1167 struct klist *klist;
1170 lwkt_gettoken(&bpf_token);
1172 if (d->bd_bif == NULL) {
1174 lwkt_reltoken(&bpf_token);
1179 switch (kn->kn_filter) {
1181 kn->kn_fop = &bpf_read_filtops;
1182 kn->kn_hook = (caddr_t)d;
1185 ap->a_result = EOPNOTSUPP;
1186 lwkt_reltoken(&bpf_token);
1190 klist = &d->bd_kq.ki_note;
1191 knote_insert(klist, kn);
1192 lwkt_reltoken(&bpf_token);
1198 bpf_filter_detach(struct knote *kn)
1200 struct klist *klist;
1203 d = (struct bpf_d *)kn->kn_hook;
1204 klist = &d->bd_kq.ki_note;
1205 knote_remove(klist, kn);
1209 bpf_filter_read(struct knote *kn, long hint)
1214 d = (struct bpf_d *)kn->kn_hook;
1215 if (d->bd_hlen != 0 ||
1216 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1220 /* Start the read timeout if necessary. */
1221 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1222 callout_reset(&d->bd_callout, d->bd_rtout,
1224 d->bd_state = BPF_WAITING;
1233 * Process the packet pkt of length pktlen. The packet is parsed
1234 * by each listener's filter, and if accepted, stashed into the
1235 * corresponding buffer.
1238 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1245 lwkt_gettoken(&bpf_token);
1248 lwkt_reltoken(&bpf_token);
1253 * Note that the ipl does not have to be raised at this point.
1254 * The only problem that could arise here is that if two different
1255 * interfaces shared any data. This is not the case.
1257 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1259 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1265 catchpacket(d, pkt, pktlen, slen, _bcopy, &tv);
1268 lwkt_reltoken(&bpf_token);
1272 * Copy data from an mbuf chain into a buffer. This code is derived
1273 * from m_copydata in sys/uipc_mbuf.c.
1276 bpf_mcopy(volatile const void *src_arg, volatile void *dst_arg, size_t len)
1278 volatile const struct mbuf *m;
1280 volatile u_char *dst;
1287 count = min(m->m_len, len);
1288 bcopy(mtod(m, void *), dst, count);
1296 * Process the packet in the mbuf chain m. The packet is parsed by each
1297 * listener's filter, and if accepted, stashed into the corresponding
1301 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1308 lwkt_gettoken(&bpf_token);
1311 lwkt_reltoken(&bpf_token);
1315 /* Don't compute pktlen, if no descriptor is attached. */
1316 if (SLIST_EMPTY(&bp->bif_dlist)) {
1317 lwkt_reltoken(&bpf_token);
1321 pktlen = m_lengthm(m, NULL);
1323 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1324 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1327 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1333 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1337 lwkt_reltoken(&bpf_token);
1341 * Incoming linkage from device drivers, where we have a mbuf chain
1342 * but need to prepend some arbitrary header from a linear buffer.
1344 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1345 * struct m_hdr on the stack. This is safe as bpf only reads from the
1346 * fields in this header that we initialize, and will not try to free
1347 * it or keep a pointer to it.
1350 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m,
1360 bpf_mtap(arg, (struct mbuf *) &mh);
1364 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1368 KKASSERT(family != AF_UNSPEC);
1370 family4 = (u_int)family;
1371 bpf_ptap(bp, m, &family4, sizeof(family4));
1375 * Process the packet in the mbuf chain m with the header in m prepended.
1376 * The packet is parsed by each listener's filter, and if accepted,
1377 * stashed into the corresponding buffer.
1380 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1385 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1386 * Note that we cut corners here; we only setup what's
1387 * absolutely needed--this mbuf should never go anywhere else.
1390 mb.m_data = __DECONST(void *, data); /* LINTED */
1392 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1398 * Move the packet data from interface memory (pkt) into the
1399 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1400 * otherwise 0. "copy" is the routine called to do the actual data
1401 * transfer. bcopy is passed in to copy contiguous chunks, while
1402 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1403 * pkt is really an mbuf.
1406 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1407 void (*cpfn)(volatile const void *, volatile void *, size_t),
1408 const struct timeval *tv)
1412 int hdrlen = d->bd_bif->bif_hdrlen;
1415 * Figure out how many bytes to move. If the packet is
1416 * greater or equal to the snapshot length, transfer that
1417 * much. Otherwise, transfer the whole packet (unless
1418 * we hit the buffer size limit).
1420 totlen = hdrlen + min(snaplen, pktlen);
1421 if (totlen > d->bd_bufsize)
1422 totlen = d->bd_bufsize;
1425 * Round up the end of the previous packet to the next longword.
1427 curlen = BPF_WORDALIGN(d->bd_slen);
1428 if (curlen + totlen > d->bd_bufsize) {
1430 * This packet will overflow the storage buffer.
1431 * Rotate the buffers if we can, then wakeup any
1434 if (d->bd_fbuf == NULL) {
1436 * We haven't completed the previous read yet,
1437 * so drop the packet.
1445 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1447 * Immediate mode is set, or the read timeout has
1448 * already expired during a select call. A packet
1449 * arrived, so the reader should be woken up.
1455 * Append the bpf header.
1457 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1458 hp->bh_tstamp = *tv;
1459 hp->bh_datalen = pktlen;
1460 hp->bh_hdrlen = hdrlen;
1462 * Copy the packet data into the store buffer and update its length.
1464 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1465 d->bd_slen = curlen + totlen;
1472 * Initialize all nonzero fields of a descriptor.
1475 bpf_allocbufs(struct bpf_d *d)
1477 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1478 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1485 * Free buffers and packet filter program currently in use by a descriptor.
1489 bpf_freed(struct bpf_d *d)
1492 * We don't need to lock out interrupts since this descriptor has
1493 * been detached from its interface and it yet hasn't been marked
1496 if (d->bd_sbuf != NULL) {
1497 kfree(d->bd_sbuf, M_BPF);
1498 if (d->bd_hbuf != NULL)
1499 kfree(d->bd_hbuf, M_BPF);
1500 if (d->bd_fbuf != NULL)
1501 kfree(d->bd_fbuf, M_BPF);
1504 kfree(d->bd_rfilter, M_BPF);
1506 kfree(d->bd_wfilter, M_BPF);
1510 * Attach an interface to bpf. ifp is a pointer to the structure
1511 * defining the interface to be attached, dlt is the link layer type,
1512 * and hdrlen is the fixed size of the link header (variable length
1513 * headers are not yet supported).
1516 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1518 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1522 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1526 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1528 lwkt_gettoken(&bpf_token);
1530 SLIST_INIT(&bp->bif_dlist);
1533 bp->bif_driverp = driverp;
1534 *bp->bif_driverp = NULL;
1536 bp->bif_next = bpf_iflist;
1540 * Compute the length of the bpf header. This is not necessarily
1541 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1542 * that the network layer header begins on a longword boundary (for
1543 * performance reasons and to alleviate alignment restrictions).
1545 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1547 lwkt_reltoken(&bpf_token);
1550 if_printf(ifp, "bpf attached\n");
1554 * Detach bpf from an interface. This involves detaching each descriptor
1555 * associated with the interface, and leaving bd_bif NULL. Notify each
1556 * descriptor as it's detached so that any sleepers wake up and get
1560 bpfdetach(struct ifnet *ifp)
1562 struct bpf_if *bp, *bp_prev;
1565 lwkt_gettoken(&bpf_token);
1567 /* Locate BPF interface information */
1569 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1570 if (ifp == bp->bif_ifp)
1575 /* Interface wasn't attached */
1576 if (bp->bif_ifp == NULL) {
1577 lwkt_reltoken(&bpf_token);
1578 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1582 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1587 if (bp_prev != NULL)
1588 bp_prev->bif_next = bp->bif_next;
1590 bpf_iflist = bp->bif_next;
1594 lwkt_reltoken(&bpf_token);
1598 * Get a list of available data link type of the interface.
1601 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1607 ifp = d->bd_bif->bif_ifp;
1610 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1611 if (bp->bif_ifp != ifp)
1613 if (bfl->bfl_list != NULL) {
1614 if (n >= bfl->bfl_len) {
1617 error = copyout(&bp->bif_dlt,
1618 bfl->bfl_list + n, sizeof(u_int));
1627 * Set the data link type of a BPF instance.
1630 bpf_setdlt(struct bpf_d *d, u_int dlt)
1632 int error, opromisc;
1636 if (d->bd_bif->bif_dlt == dlt)
1638 ifp = d->bd_bif->bif_ifp;
1639 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1640 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1644 opromisc = d->bd_promisc;
1649 error = ifpromisc(bp->bif_ifp, 1);
1651 if_printf(bp->bif_ifp,
1652 "bpf_setdlt: ifpromisc failed (%d)\n",
1659 return(bp == NULL ? EINVAL : 0);
1665 lwkt_gettoken(&bpf_token);
1671 lwkt_reltoken(&bpf_token);
1675 bpf_drvinit(void *unused)
1679 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1680 bpfclone, 0, 0, 0600, "bpf");
1681 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1682 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1683 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1688 bpf_drvuninit(void *unused)
1690 devfs_clone_handler_del("bpf");
1691 dev_ops_remove_all(&bpf_ops);
1692 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1695 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR, bpf_drvinit, NULL);
1696 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1700 * NOP stubs to allow bpf-using drivers to load and function.
1702 * A 'better' implementation would allow the core bpf functionality
1703 * to be loaded at runtime.
1707 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1712 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1717 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1722 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1727 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1732 bpfdetach(struct ifnet *ifp)
1737 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1739 return -1; /* "no filter" behaviour */