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>
44 #include <sys/device.h>
45 #include <sys/malloc.h>
49 #include <sys/signalvar.h>
50 #include <sys/filio.h>
51 #include <sys/sockio.h>
52 #include <sys/ttycom.h>
53 #include <sys/filedesc.h>
55 #include <sys/event.h>
57 #include <sys/socket.h>
58 #include <sys/vnode.h>
62 #include <net/bpfdesc.h>
63 #include <net/netmsg2.h>
64 #include <net/netisr2.h>
66 #include <netinet/in.h>
67 #include <netinet/if_ether.h>
68 #include <sys/kernel.h>
69 #include <sys/sysctl.h>
71 #include <netproto/802_11/ieee80211_dragonfly.h>
73 #include <sys/devfs.h>
75 struct netmsg_bpf_output {
76 struct netmsg_base base;
79 struct sockaddr *nm_dst;
80 boolean_t nm_feedback;
83 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
84 DEVFS_DEFINE_CLONE_BITMAP(bpf);
87 #define BPF_PREALLOCATED_UNITS 4
89 #define BPF_PREALLOCATED_UNITS NBPF
95 * The default read buffer size is patchable.
97 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
98 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
99 &bpf_bufsize, 0, "Current size of bpf buffer");
100 int bpf_maxbufsize = BPF_MAXBUFSIZE;
101 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
102 &bpf_maxbufsize, 0, "Maximum size of bpf buffer");
105 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
107 static struct bpf_if *bpf_iflist;
109 static struct lwkt_token bpf_token = LWKT_TOKEN_INITIALIZER(bpf_token);
111 static int bpf_allocbufs(struct bpf_d *);
112 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
113 static void bpf_detachd(struct bpf_d *d);
114 static void bpf_resetd(struct bpf_d *);
115 static void bpf_freed(struct bpf_d *);
116 static void bpf_mcopy(volatile const void *, volatile void *, size_t);
117 static int bpf_movein(struct uio *, int, struct mbuf **,
118 struct sockaddr *, int *, struct bpf_insn *);
119 static int bpf_setif(struct bpf_d *, struct ifreq *);
120 static void bpf_timed_out(void *);
121 static void bpf_wakeup(struct bpf_d *);
122 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
123 void (*)(volatile const void *,
124 volatile void *, size_t),
125 const struct timeval *);
126 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
127 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
128 static int bpf_setdlt(struct bpf_d *, u_int);
129 static void bpf_drvinit(void *unused);
130 static void bpf_filter_detach(struct knote *kn);
131 static int bpf_filter_read(struct knote *kn, long hint);
133 static d_open_t bpfopen;
134 static d_clone_t bpfclone;
135 static d_close_t bpfclose;
136 static d_read_t bpfread;
137 static d_write_t bpfwrite;
138 static d_ioctl_t bpfioctl;
139 static d_kqfilter_t bpfkqfilter;
141 #define CDEV_MAJOR 23
142 static struct dev_ops bpf_ops = {
143 { "bpf", 0, D_MPSAFE },
149 .d_kqfilter = bpfkqfilter
154 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
155 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
157 const struct ieee80211_bpf_params *p;
168 * Build a sockaddr based on the data link layer type.
169 * We do this at this level because the ethernet header
170 * is copied directly into the data field of the sockaddr.
171 * In the case of SLIP, there is no header and the packet
172 * is forwarded as is.
173 * Also, we are careful to leave room at the front of the mbuf
174 * for the link level header.
178 sockp->sa_family = AF_INET;
183 sockp->sa_family = AF_UNSPEC;
184 /* XXX Would MAXLINKHDR be better? */
185 hlen = sizeof(struct ether_header);
190 sockp->sa_family = AF_UNSPEC;
194 case DLT_ATM_RFC1483:
196 * en atm driver requires 4-byte atm pseudo header.
197 * though it isn't standard, vpi:vci needs to be
200 sockp->sa_family = AF_UNSPEC;
201 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
205 sockp->sa_family = AF_UNSPEC;
206 hlen = 4; /* This should match PPP_HDRLEN */
209 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
210 sockp->sa_family = AF_IEEE80211;
214 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
215 sockp->sa_family = AF_IEEE80211;
216 sockp->sa_len = 12; /* XXX != 0 */
217 hlen = sizeof(struct ieee80211_bpf_params);
224 len = uio->uio_resid;
225 *datlen = len - hlen;
226 if ((unsigned)len > MCLBYTES)
229 m = m_getl(len, M_WAITOK, MT_DATA, M_PKTHDR, NULL);
232 m->m_pkthdr.len = m->m_len = len;
233 m->m_pkthdr.rcvif = NULL;
236 if (m->m_len < hlen) {
241 error = uiomove(mtod(m, u_char *), len, uio);
245 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
252 * Make room for link header, and copy it to sockaddr.
255 if (sockp->sa_family == AF_IEEE80211) {
257 * Collect true length from the parameter header
258 * NB: sockp is known to be zero'd so if we do a
259 * short copy unspecified parameters will be
261 * NB: packet may not be aligned after stripping
265 p = mtod(m, const struct ieee80211_bpf_params *);
267 if (hlen > sizeof(sockp->sa_data)) {
272 bcopy(m->m_data, sockp->sa_data, hlen);
273 m->m_pkthdr.len -= hlen;
275 m->m_data += hlen; /* XXX */
284 * Attach file to the bpf interface, i.e. make d listen on bp.
285 * Must be called at splimp.
288 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
291 * Point d at bp, and add d to the interface's list of listeners.
292 * Finally, point the driver's bpf cookie at the interface so
293 * it will divert packets to bpf.
295 lwkt_gettoken(&bpf_token);
297 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
298 *bp->bif_driverp = bp;
300 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
301 lwkt_reltoken(&bpf_token);
305 * Detach a file from its interface.
308 bpf_detachd(struct bpf_d *d)
314 lwkt_gettoken(&bpf_token);
318 /* Remove d from the interface's descriptor list. */
319 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
321 if (SLIST_EMPTY(&bp->bif_dlist)) {
323 * Let the driver know that there are no more listeners.
325 *bp->bif_driverp = NULL;
329 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
332 * Check if this descriptor had requested promiscuous mode.
333 * If so, turn it off.
337 error = ifpromisc(ifp, 0);
338 if (error != 0 && error != ENXIO) {
340 * ENXIO can happen if a pccard is unplugged,
341 * Something is really wrong if we were able to put
342 * the driver into promiscuous mode, but can't
345 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
349 lwkt_reltoken(&bpf_token);
353 * Open ethernet device. Returns ENXIO for illegal minor device number,
354 * EBUSY if file is open by another process.
358 bpfopen(struct dev_open_args *ap)
360 cdev_t dev = ap->a_head.a_dev;
363 lwkt_gettoken(&bpf_token);
364 if (ap->a_cred->cr_prison) {
365 lwkt_reltoken(&bpf_token);
371 * Each minor can be opened by only one process. If the requested
372 * minor is in use, return EBUSY.
375 lwkt_reltoken(&bpf_token);
379 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
381 d->bd_bufsize = bpf_bufsize;
385 callout_init(&d->bd_callout);
386 lwkt_reltoken(&bpf_token);
392 bpfclone(struct dev_clone_args *ap)
396 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
397 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
403 * Close the descriptor by detaching it from its interface,
404 * deallocating its buffers, and marking it free.
408 bpfclose(struct dev_close_args *ap)
410 cdev_t dev = ap->a_head.a_dev;
411 struct bpf_d *d = dev->si_drv1;
414 lwkt_gettoken(&bpf_token);
415 funsetown(&d->bd_sigio);
416 if (d->bd_state == BPF_WAITING)
417 callout_stop(&d->bd_callout);
418 d->bd_state = BPF_IDLE;
419 if (d->bd_bif != NULL)
424 unit = dev->si_uminor;
425 if (unit >= BPF_PREALLOCATED_UNITS) {
427 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), unit);
430 lwkt_reltoken(&bpf_token);
436 * Rotate the packet buffers in descriptor d. Move the store buffer
437 * into the hold slot, and the free buffer into the store slot.
438 * Zero the length of the new store buffer.
440 #define ROTATE_BUFFERS(d) \
441 (d)->bd_hbuf = (d)->bd_sbuf; \
442 (d)->bd_hlen = (d)->bd_slen; \
443 (d)->bd_sbuf = (d)->bd_fbuf; \
447 * bpfread - read next chunk of packets from buffers
450 bpfread(struct dev_read_args *ap)
452 cdev_t dev = ap->a_head.a_dev;
453 struct bpf_d *d = dev->si_drv1;
457 lwkt_gettoken(&bpf_token);
459 * Restrict application to use a buffer the same size as
462 if (ap->a_uio->uio_resid != d->bd_bufsize) {
463 lwkt_reltoken(&bpf_token);
467 if (d->bd_state == BPF_WAITING)
468 callout_stop(&d->bd_callout);
469 timed_out = (d->bd_state == BPF_TIMED_OUT);
470 d->bd_state = BPF_IDLE;
472 * If the hold buffer is empty, then do a timed sleep, which
473 * ends when the timeout expires or when enough packets
474 * have arrived to fill the store buffer.
476 while (d->bd_hbuf == NULL) {
477 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
478 && d->bd_slen != 0) {
480 * A packet(s) either arrived since the previous,
481 * We're in immediate mode, or are reading
482 * in non-blocking mode, and a packet(s)
483 * either arrived since the previous
484 * read or arrived while we were asleep.
485 * Rotate the buffers and return what's here.
492 * No data is available, check to see if the bpf device
493 * is still pointed at a real interface. If not, return
494 * ENXIO so that the userland process knows to rebind
495 * it before using it again.
497 if (d->bd_bif == NULL) {
498 lwkt_reltoken(&bpf_token);
502 if (ap->a_ioflag & IO_NDELAY) {
503 lwkt_reltoken(&bpf_token);
506 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
507 if (error == EINTR || error == ERESTART) {
508 lwkt_reltoken(&bpf_token);
511 if (error == EWOULDBLOCK) {
513 * On a timeout, return what's in the buffer,
514 * which may be nothing. If there is something
515 * in the store buffer, we can rotate the buffers.
519 * We filled up the buffer in between
520 * getting the timeout and arriving
521 * here, so we don't need to rotate.
525 if (d->bd_slen == 0) {
526 lwkt_reltoken(&bpf_token);
534 * At this point, we know we have something in the hold slot.
538 * Move data from hold buffer into user space.
539 * We know the entire buffer is transferred since
540 * we checked above that the read buffer is bpf_bufsize bytes.
542 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
544 d->bd_fbuf = d->bd_hbuf;
547 lwkt_reltoken(&bpf_token);
554 * If there are processes sleeping on this descriptor, wake them up.
557 bpf_wakeup(struct bpf_d *d)
559 if (d->bd_state == BPF_WAITING) {
560 callout_stop(&d->bd_callout);
561 d->bd_state = BPF_IDLE;
564 if (d->bd_async && d->bd_sig && d->bd_sigio)
565 pgsigio(d->bd_sigio, d->bd_sig, 0);
567 KNOTE(&d->bd_kq.ki_note, 0);
571 bpf_timed_out(void *arg)
573 struct bpf_d *d = (struct bpf_d *)arg;
575 if (d->bd_state == BPF_WAITING) {
576 d->bd_state = BPF_TIMED_OUT;
583 bpf_output_dispatch(netmsg_t msg)
585 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
586 struct ifnet *ifp = bmsg->nm_ifp;
587 struct mbuf *mc = NULL;
590 if (bmsg->nm_feedback) {
591 mc = m_dup(bmsg->nm_mbuf, M_NOWAIT);
593 mc->m_pkthdr.rcvif = ifp;
597 * The driver frees the mbuf.
599 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
600 lwkt_replymsg(&msg->lmsg, error);
604 mc->m_flags &= ~M_HASH;
605 (*ifp->if_input)(ifp, mc, NULL, -1);
613 bpfwrite(struct dev_write_args *ap)
615 cdev_t dev = ap->a_head.a_dev;
616 struct bpf_d *d = dev->si_drv1;
622 struct netmsg_bpf_output bmsg;
624 lwkt_gettoken(&bpf_token);
625 if (d->bd_bif == NULL) {
626 lwkt_reltoken(&bpf_token);
630 ifp = d->bd_bif->bif_ifp;
632 if (ap->a_uio->uio_resid == 0) {
633 lwkt_reltoken(&bpf_token);
637 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
638 &dst, &datlen, d->bd_wfilter);
640 lwkt_reltoken(&bpf_token);
644 if (datlen > ifp->if_mtu) {
646 lwkt_reltoken(&bpf_token);
651 dst.sa_family = pseudo_AF_HDRCMPLT;
653 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
654 0, bpf_output_dispatch);
660 bmsg.nm_feedback = TRUE;
662 bmsg.nm_feedback = FALSE;
664 ret = lwkt_domsg(netisr_cpuport(0), &bmsg.base.lmsg, 0);
666 lwkt_reltoken(&bpf_token);
672 * Reset a descriptor by flushing its packet buffer and clearing the
673 * receive and drop counts. Should be called at splimp.
676 bpf_resetd(struct bpf_d *d)
679 /* Free the hold buffer. */
680 d->bd_fbuf = d->bd_hbuf;
690 * FIONREAD Check for read packet available.
691 * SIOCGIFADDR Get interface address - convenient hook to driver.
692 * BIOCGBLEN Get buffer len [for read()].
693 * BIOCSETF Set ethernet read filter.
694 * BIOCSETWF Set ethernet write filter.
695 * BIOCFLUSH Flush read packet buffer.
696 * BIOCPROMISC Put interface into promiscuous mode.
697 * BIOCGDLT Get link layer type.
698 * BIOCGETIF Get interface name.
699 * BIOCSETIF Set interface.
700 * BIOCSRTIMEOUT Set read timeout.
701 * BIOCGRTIMEOUT Get read timeout.
702 * BIOCGSTATS Get packet stats.
703 * BIOCIMMEDIATE Set immediate mode.
704 * BIOCVERSION Get filter language version.
705 * BIOCGHDRCMPLT Get "header already complete" flag
706 * BIOCSHDRCMPLT Set "header already complete" flag
707 * BIOCSFEEDBACK Set packet feedback mode.
708 * BIOCGFEEDBACK Get packet feedback mode.
709 * BIOCGSEESENT Get "see packets sent" flag
710 * BIOCSSEESENT Set "see packets sent" flag
711 * BIOCLOCK Set "locked" flag
715 bpfioctl(struct dev_ioctl_args *ap)
717 cdev_t dev = ap->a_head.a_dev;
718 struct bpf_d *d = dev->si_drv1;
721 lwkt_gettoken(&bpf_token);
722 if (d->bd_state == BPF_WAITING)
723 callout_stop(&d->bd_callout);
724 d->bd_state = BPF_IDLE;
726 if (d->bd_locked == 1) {
745 lwkt_reltoken(&bpf_token);
755 * Check for read packet available.
765 *(int *)ap->a_data = n;
773 if (d->bd_bif == NULL) {
776 ifp = d->bd_bif->bif_ifp;
777 ifnet_serialize_all(ifp);
778 error = ifp->if_ioctl(ifp, ap->a_cmd,
779 ap->a_data, ap->a_cred);
780 ifnet_deserialize_all(ifp);
786 * Get buffer len [for read()].
789 *(u_int *)ap->a_data = d->bd_bufsize;
796 if (d->bd_bif != NULL) {
799 u_int size = *(u_int *)ap->a_data;
801 if (size > bpf_maxbufsize)
802 *(u_int *)ap->a_data = size = bpf_maxbufsize;
803 else if (size < BPF_MINBUFSIZE)
804 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
805 d->bd_bufsize = size;
810 * Set link layer read filter.
814 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
819 * Flush read packet buffer.
826 * Put interface into promiscuous mode.
829 if (d->bd_bif == NULL) {
831 * No interface attached yet.
836 if (d->bd_promisc == 0) {
837 error = ifpromisc(d->bd_bif->bif_ifp, 1);
844 * Get device parameters.
847 if (d->bd_bif == NULL)
850 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
854 * Get a list of supported data link types.
857 if (d->bd_bif == NULL) {
860 error = bpf_getdltlist(d,
861 (struct bpf_dltlist *)ap->a_data);
866 * Set data link type.
869 if (d->bd_bif == NULL)
872 error = bpf_setdlt(d, *(u_int *)ap->a_data);
876 * Get interface name.
879 if (d->bd_bif == NULL) {
882 struct ifnet *const ifp = d->bd_bif->bif_ifp;
883 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
885 strlcpy(ifr->ifr_name, ifp->if_xname,
886 sizeof ifr->ifr_name);
894 error = bpf_setif(d, (struct ifreq *)ap->a_data);
902 struct timeval *tv = (struct timeval *)ap->a_data;
905 * Subtract 1 tick from tvtohz() since this isn't
908 if ((error = itimerfix(tv)) == 0)
909 d->bd_rtout = tvtohz_low(tv);
918 struct timeval *tv = (struct timeval *)ap->a_data;
920 tv->tv_sec = d->bd_rtout / hz;
921 tv->tv_usec = (d->bd_rtout % hz) * ustick;
930 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
932 bs->bs_recv = d->bd_rcount;
933 bs->bs_drop = d->bd_dcount;
938 * Set immediate mode.
941 d->bd_immediate = *(u_int *)ap->a_data;
946 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
948 bv->bv_major = BPF_MAJOR_VERSION;
949 bv->bv_minor = BPF_MINOR_VERSION;
954 * Get "header already complete" flag
957 *(u_int *)ap->a_data = d->bd_hdrcmplt;
961 * Set "header already complete" flag
964 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
968 * Get "see sent packets" flag
971 *(u_int *)ap->a_data = d->bd_seesent;
975 * Set "see sent packets" flag
978 d->bd_seesent = *(u_int *)ap->a_data;
981 case FIOASYNC: /* Send signal on receive packets */
982 d->bd_async = *(int *)ap->a_data;
986 * Set "feed packets from bpf back to input" mode
989 d->bd_feedback = *(int *)ap->a_data;
993 * Get "feed packets from bpf back to input" mode
996 *(u_int *)ap->a_data = d->bd_feedback;
1000 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
1004 *(int *)ap->a_data = fgetown(&d->bd_sigio);
1007 /* This is deprecated, FIOSETOWN should be used instead. */
1009 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
1012 /* This is deprecated, FIOGETOWN should be used instead. */
1014 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
1017 case BIOCSRSIG: /* Set receive signal */
1021 sig = *(u_int *)ap->a_data;
1030 *(u_int *)ap->a_data = d->bd_sig;
1036 lwkt_reltoken(&bpf_token);
1042 * Set d's packet filter program to fp. If this file already has a filter,
1043 * free it and replace it. Returns EINVAL for bogus requests.
1046 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1048 struct bpf_insn *fcode, *old;
1049 u_int wfilter, flen, size;
1051 if (cmd == BIOCSETWF) {
1052 old = d->bd_wfilter;
1056 old = d->bd_rfilter;
1058 if (fp->bf_insns == NULL) {
1059 if (fp->bf_len != 0)
1062 d->bd_wfilter = NULL;
1064 d->bd_rfilter = NULL;
1071 if (flen > BPF_MAXINSNS)
1074 size = flen * sizeof *fp->bf_insns;
1075 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
1076 if (copyin(fp->bf_insns, fcode, size) == 0 &&
1077 bpf_validate(fcode, (int)flen)) {
1079 d->bd_wfilter = fcode;
1081 d->bd_rfilter = fcode;
1088 kfree(fcode, M_BPF);
1093 * Detach a file from its current interface (if attached at all) and attach
1094 * to the interface indicated by the name stored in ifr.
1095 * Return an errno or 0.
1098 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1102 struct ifnet *theywant;
1106 theywant = ifunit(ifr->ifr_name);
1107 if (theywant == NULL) {
1113 * Look through attached interfaces for the named one.
1115 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1116 struct ifnet *ifp = bp->bif_ifp;
1118 if (ifp == NULL || ifp != theywant)
1120 /* skip additional entry */
1121 if (bp->bif_driverp != &ifp->if_bpf)
1124 * We found the requested interface.
1125 * Allocate the packet buffers if we need to.
1126 * If we're already attached to requested interface,
1127 * just flush the buffer.
1129 if (d->bd_sbuf == NULL) {
1130 error = bpf_allocbufs(d);
1136 if (bp != d->bd_bif) {
1137 if (d->bd_bif != NULL) {
1139 * Detach if attached to something else.
1158 static struct filterops bpf_read_filtops =
1159 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1162 bpfkqfilter(struct dev_kqfilter_args *ap)
1164 cdev_t dev = ap->a_head.a_dev;
1165 struct knote *kn = ap->a_kn;
1166 struct klist *klist;
1169 lwkt_gettoken(&bpf_token);
1171 if (d->bd_bif == NULL) {
1173 lwkt_reltoken(&bpf_token);
1178 switch (kn->kn_filter) {
1180 kn->kn_fop = &bpf_read_filtops;
1181 kn->kn_hook = (caddr_t)d;
1184 ap->a_result = EOPNOTSUPP;
1185 lwkt_reltoken(&bpf_token);
1189 klist = &d->bd_kq.ki_note;
1190 knote_insert(klist, kn);
1191 lwkt_reltoken(&bpf_token);
1197 bpf_filter_detach(struct knote *kn)
1199 struct klist *klist;
1202 d = (struct bpf_d *)kn->kn_hook;
1203 klist = &d->bd_kq.ki_note;
1204 knote_remove(klist, kn);
1208 bpf_filter_read(struct knote *kn, long hint)
1213 d = (struct bpf_d *)kn->kn_hook;
1214 if (d->bd_hlen != 0 ||
1215 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1219 /* Start the read timeout if necessary. */
1220 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1221 callout_reset(&d->bd_callout, d->bd_rtout,
1223 d->bd_state = BPF_WAITING;
1232 * Process the packet pkt of length pktlen. The packet is parsed
1233 * by each listener's filter, and if accepted, stashed into the
1234 * corresponding buffer.
1237 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1244 lwkt_gettoken(&bpf_token);
1247 lwkt_reltoken(&bpf_token);
1252 * Note that the ipl does not have to be raised at this point.
1253 * The only problem that could arise here is that if two different
1254 * interfaces shared any data. This is not the case.
1256 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1258 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1264 catchpacket(d, pkt, pktlen, slen, _bcopy, &tv);
1267 lwkt_reltoken(&bpf_token);
1271 * Copy data from an mbuf chain into a buffer. This code is derived
1272 * from m_copydata in sys/uipc_mbuf.c.
1275 bpf_mcopy(volatile const void *src_arg, volatile void *dst_arg, size_t len)
1277 volatile const struct mbuf *m;
1279 volatile u_char *dst;
1286 count = min(m->m_len, len);
1287 bcopy(mtod(m, void *), dst, count);
1295 * Process the packet in the mbuf chain m. The packet is parsed by each
1296 * listener's filter, and if accepted, stashed into the corresponding
1300 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1307 lwkt_gettoken(&bpf_token);
1310 lwkt_reltoken(&bpf_token);
1314 /* Don't compute pktlen, if no descriptor is attached. */
1315 if (SLIST_EMPTY(&bp->bif_dlist)) {
1316 lwkt_reltoken(&bpf_token);
1320 pktlen = m_lengthm(m, NULL);
1322 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1323 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1326 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1332 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1336 lwkt_reltoken(&bpf_token);
1340 * Incoming linkage from device drivers, where we have a mbuf chain
1341 * but need to prepend some arbitrary header from a linear buffer.
1343 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1344 * struct m_hdr on the stack. This is safe as bpf only reads from the
1345 * fields in this header that we initialize, and will not try to free
1346 * it or keep a pointer to it.
1349 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m,
1359 bpf_mtap(arg, (struct mbuf *) &mh);
1363 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1367 KKASSERT(family != AF_UNSPEC);
1369 family4 = (u_int)family;
1370 bpf_ptap(bp, m, &family4, sizeof(family4));
1374 * Process the packet in the mbuf chain m with the header in m prepended.
1375 * The packet is parsed by each listener's filter, and if accepted,
1376 * stashed into the corresponding buffer.
1379 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1384 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1385 * Note that we cut corners here; we only setup what's
1386 * absolutely needed--this mbuf should never go anywhere else.
1389 mb.m_data = __DECONST(void *, data); /* LINTED */
1391 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1397 * Move the packet data from interface memory (pkt) into the
1398 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1399 * otherwise 0. "copy" is the routine called to do the actual data
1400 * transfer. bcopy is passed in to copy contiguous chunks, while
1401 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1402 * pkt is really an mbuf.
1405 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1406 void (*cpfn)(volatile const void *, volatile void *, size_t),
1407 const struct timeval *tv)
1411 int hdrlen = d->bd_bif->bif_hdrlen;
1414 * Figure out how many bytes to move. If the packet is
1415 * greater or equal to the snapshot length, transfer that
1416 * much. Otherwise, transfer the whole packet (unless
1417 * we hit the buffer size limit).
1419 totlen = hdrlen + min(snaplen, pktlen);
1420 if (totlen > d->bd_bufsize)
1421 totlen = d->bd_bufsize;
1424 * Round up the end of the previous packet to the next longword.
1426 curlen = BPF_WORDALIGN(d->bd_slen);
1427 if (curlen + totlen > d->bd_bufsize) {
1429 * This packet will overflow the storage buffer.
1430 * Rotate the buffers if we can, then wakeup any
1433 if (d->bd_fbuf == NULL) {
1435 * We haven't completed the previous read yet,
1436 * so drop the packet.
1444 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1446 * Immediate mode is set, or the read timeout has
1447 * already expired during a select call. A packet
1448 * arrived, so the reader should be woken up.
1454 * Append the bpf header.
1456 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1457 hp->bh_tstamp = *tv;
1458 hp->bh_datalen = pktlen;
1459 hp->bh_hdrlen = hdrlen;
1461 * Copy the packet data into the store buffer and update its length.
1463 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1464 d->bd_slen = curlen + totlen;
1471 * Initialize all nonzero fields of a descriptor.
1474 bpf_allocbufs(struct bpf_d *d)
1476 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1477 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1484 * Free buffers and packet filter program currently in use by a descriptor.
1488 bpf_freed(struct bpf_d *d)
1491 * We don't need to lock out interrupts since this descriptor has
1492 * been detached from its interface and it yet hasn't been marked
1495 if (d->bd_sbuf != NULL) {
1496 kfree(d->bd_sbuf, M_BPF);
1497 if (d->bd_hbuf != NULL)
1498 kfree(d->bd_hbuf, M_BPF);
1499 if (d->bd_fbuf != NULL)
1500 kfree(d->bd_fbuf, M_BPF);
1503 kfree(d->bd_rfilter, M_BPF);
1505 kfree(d->bd_wfilter, M_BPF);
1509 * Attach an interface to bpf. ifp is a pointer to the structure
1510 * defining the interface to be attached, dlt is the link layer type,
1511 * and hdrlen is the fixed size of the link header (variable length
1512 * headers are not yet supported).
1515 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1517 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1521 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1525 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1527 lwkt_gettoken(&bpf_token);
1529 SLIST_INIT(&bp->bif_dlist);
1532 bp->bif_driverp = driverp;
1533 *bp->bif_driverp = NULL;
1535 bp->bif_next = bpf_iflist;
1539 * Compute the length of the bpf header. This is not necessarily
1540 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1541 * that the network layer header begins on a longword boundary (for
1542 * performance reasons and to alleviate alignment restrictions).
1544 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1546 lwkt_reltoken(&bpf_token);
1549 if_printf(ifp, "bpf attached\n");
1553 * Detach bpf from an interface. This involves detaching each descriptor
1554 * associated with the interface, and leaving bd_bif NULL. Notify each
1555 * descriptor as it's detached so that any sleepers wake up and get
1559 bpfdetach(struct ifnet *ifp)
1561 struct bpf_if *bp, *bp_prev;
1564 lwkt_gettoken(&bpf_token);
1566 /* Locate BPF interface information */
1568 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1569 if (ifp == bp->bif_ifp)
1574 /* Interface wasn't attached */
1575 if (bp->bif_ifp == NULL) {
1576 lwkt_reltoken(&bpf_token);
1577 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1581 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1586 if (bp_prev != NULL)
1587 bp_prev->bif_next = bp->bif_next;
1589 bpf_iflist = bp->bif_next;
1593 lwkt_reltoken(&bpf_token);
1597 * Get a list of available data link type of the interface.
1600 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1606 ifp = d->bd_bif->bif_ifp;
1609 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1610 if (bp->bif_ifp != ifp)
1612 if (bfl->bfl_list != NULL) {
1613 if (n >= bfl->bfl_len) {
1616 error = copyout(&bp->bif_dlt,
1617 bfl->bfl_list + n, sizeof(u_int));
1626 * Set the data link type of a BPF instance.
1629 bpf_setdlt(struct bpf_d *d, u_int dlt)
1631 int error, opromisc;
1635 if (d->bd_bif->bif_dlt == dlt)
1637 ifp = d->bd_bif->bif_ifp;
1638 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1639 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1643 opromisc = d->bd_promisc;
1648 error = ifpromisc(bp->bif_ifp, 1);
1650 if_printf(bp->bif_ifp,
1651 "bpf_setdlt: ifpromisc failed (%d)\n",
1658 return(bp == NULL ? EINVAL : 0);
1664 lwkt_gettoken(&bpf_token);
1670 lwkt_reltoken(&bpf_token);
1674 bpf_drvinit(void *unused)
1678 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1679 bpfclone, 0, 0, 0600, "bpf");
1680 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1681 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1682 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1687 bpf_drvuninit(void *unused)
1689 devfs_clone_handler_del("bpf");
1690 dev_ops_remove_all(&bpf_ops);
1691 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1694 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR, bpf_drvinit, NULL);
1695 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1699 * NOP stubs to allow bpf-using drivers to load and function.
1701 * A 'better' implementation would allow the core bpf functionality
1702 * to be loaded at runtime.
1706 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1711 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1716 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1721 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1726 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1731 bpfdetach(struct ifnet *ifp)
1736 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1738 return -1; /* "no filter" behaviour */