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 <vfs/devfs/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);
92 * The default read buffer size is patchable.
94 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
95 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
97 int bpf_maxbufsize = BPF_MAXBUFSIZE;
98 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
99 &bpf_maxbufsize, 0, "");
102 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
104 static struct bpf_if *bpf_iflist;
106 static int bpf_allocbufs(struct bpf_d *);
107 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
108 static void bpf_detachd(struct bpf_d *d);
109 static void bpf_resetd(struct bpf_d *);
110 static void bpf_freed(struct bpf_d *);
111 static void bpf_mcopy(const void *, void *, size_t);
112 static int bpf_movein(struct uio *, int, struct mbuf **,
113 struct sockaddr *, int *, struct bpf_insn *);
114 static int bpf_setif(struct bpf_d *, struct ifreq *);
115 static void bpf_timed_out(void *);
116 static void bpf_wakeup(struct bpf_d *);
117 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
118 void (*)(const void *, void *, size_t),
119 const struct timeval *);
120 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
121 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
122 static int bpf_setdlt(struct bpf_d *, u_int);
123 static void bpf_drvinit(void *unused);
125 static d_open_t bpfopen;
126 static d_clone_t bpfclone;
127 static d_close_t bpfclose;
128 static d_read_t bpfread;
129 static d_write_t bpfwrite;
130 static d_ioctl_t bpfioctl;
131 static d_poll_t bpfpoll;
133 #define CDEV_MAJOR 23
134 static struct dev_ops bpf_ops = {
135 { "bpf", CDEV_MAJOR, 0 },
146 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
147 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
159 * Build a sockaddr based on the data link layer type.
160 * We do this at this level because the ethernet header
161 * is copied directly into the data field of the sockaddr.
162 * In the case of SLIP, there is no header and the packet
163 * is forwarded as is.
164 * Also, we are careful to leave room at the front of the mbuf
165 * for the link level header.
169 sockp->sa_family = AF_INET;
174 sockp->sa_family = AF_UNSPEC;
175 /* XXX Would MAXLINKHDR be better? */
176 hlen = sizeof(struct ether_header);
181 sockp->sa_family = AF_UNSPEC;
185 case DLT_ATM_RFC1483:
187 * en atm driver requires 4-byte atm pseudo header.
188 * though it isn't standard, vpi:vci needs to be
191 sockp->sa_family = AF_UNSPEC;
192 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
196 sockp->sa_family = AF_UNSPEC;
197 hlen = 4; /* This should match PPP_HDRLEN */
204 len = uio->uio_resid;
205 *datlen = len - hlen;
206 if ((unsigned)len > MCLBYTES)
209 m = m_getl(len, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
212 m->m_pkthdr.len = m->m_len = len;
213 m->m_pkthdr.rcvif = NULL;
216 if (m->m_len < hlen) {
221 error = uiomove(mtod(m, u_char *), len, uio);
225 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
232 * Make room for link header, and copy it to sockaddr.
235 bcopy(m->m_data, sockp->sa_data, hlen);
236 m->m_pkthdr.len -= hlen;
238 m->m_data += hlen; /* XXX */
247 * Attach file to the bpf interface, i.e. make d listen on bp.
248 * Must be called at splimp.
251 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
254 * Point d at bp, and add d to the interface's list of listeners.
255 * Finally, point the driver's bpf cookie at the interface so
256 * it will divert packets to bpf.
259 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
260 *bp->bif_driverp = bp;
264 * Detach a file from its interface.
267 bpf_detachd(struct bpf_d *d)
276 /* Remove d from the interface's descriptor list. */
277 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
279 if (SLIST_EMPTY(&bp->bif_dlist)) {
281 * Let the driver know that there are no more listeners.
283 *bp->bif_driverp = NULL;
287 * Check if this descriptor had requested promiscuous mode.
288 * If so, turn it off.
292 error = ifpromisc(ifp, 0);
293 if (error != 0 && error != ENXIO) {
295 * ENXIO can happen if a pccard is unplugged,
296 * Something is really wrong if we were able to put
297 * the driver into promiscuous mode, but can't
300 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
307 * Open ethernet device. Returns ENXIO for illegal minor device number,
308 * EBUSY if file is open by another process.
312 bpfopen(struct dev_open_args *ap)
314 cdev_t dev = ap->a_head.a_dev;
317 if (ap->a_cred->cr_prison)
322 * Each minor can be opened by only one process. If the requested
323 * minor is in use, return EBUSY.
328 MALLOC(d, struct bpf_d *, sizeof *d, M_BPF, M_WAITOK | M_ZERO);
330 d->bd_bufsize = bpf_bufsize;
333 callout_init(&d->bd_callout);
338 bpfclone(struct dev_clone_args *ap)
342 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
343 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
349 * Close the descriptor by detaching it from its interface,
350 * deallocating its buffers, and marking it free.
354 bpfclose(struct dev_close_args *ap)
356 cdev_t dev = ap->a_head.a_dev;
357 struct bpf_d *d = dev->si_drv1;
359 funsetown(d->bd_sigio);
361 if (d->bd_state == BPF_WAITING)
362 callout_stop(&d->bd_callout);
363 d->bd_state = BPF_IDLE;
364 if (d->bd_bif != NULL)
369 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor);
375 * Rotate the packet buffers in descriptor d. Move the store buffer
376 * into the hold slot, and the free buffer into the store slot.
377 * Zero the length of the new store buffer.
379 #define ROTATE_BUFFERS(d) \
380 (d)->bd_hbuf = (d)->bd_sbuf; \
381 (d)->bd_hlen = (d)->bd_slen; \
382 (d)->bd_sbuf = (d)->bd_fbuf; \
386 * bpfread - read next chunk of packets from buffers
389 bpfread(struct dev_read_args *ap)
391 cdev_t dev = ap->a_head.a_dev;
392 struct bpf_d *d = dev->si_drv1;
397 * Restrict application to use a buffer the same size as
400 if (ap->a_uio->uio_resid != d->bd_bufsize)
404 if (d->bd_state == BPF_WAITING)
405 callout_stop(&d->bd_callout);
406 timed_out = (d->bd_state == BPF_TIMED_OUT);
407 d->bd_state = BPF_IDLE;
409 * If the hold buffer is empty, then do a timed sleep, which
410 * ends when the timeout expires or when enough packets
411 * have arrived to fill the store buffer.
413 while (d->bd_hbuf == NULL) {
414 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) {
416 * A packet(s) either arrived since the previous
417 * read or arrived while we were asleep.
418 * Rotate the buffers and return what's here.
425 * No data is available, check to see if the bpf device
426 * is still pointed at a real interface. If not, return
427 * ENXIO so that the userland process knows to rebind
428 * it before using it again.
430 if (d->bd_bif == NULL) {
435 if (ap->a_ioflag & IO_NDELAY) {
439 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
440 if (error == EINTR || error == ERESTART) {
444 if (error == EWOULDBLOCK) {
446 * On a timeout, return what's in the buffer,
447 * which may be nothing. If there is something
448 * in the store buffer, we can rotate the buffers.
452 * We filled up the buffer in between
453 * getting the timeout and arriving
454 * here, so we don't need to rotate.
458 if (d->bd_slen == 0) {
467 * At this point, we know we have something in the hold slot.
472 * Move data from hold buffer into user space.
473 * We know the entire buffer is transferred since
474 * we checked above that the read buffer is bpf_bufsize bytes.
476 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
479 d->bd_fbuf = d->bd_hbuf;
489 * If there are processes sleeping on this descriptor, wake them up.
492 bpf_wakeup(struct bpf_d *d)
494 if (d->bd_state == BPF_WAITING) {
495 callout_stop(&d->bd_callout);
496 d->bd_state = BPF_IDLE;
499 if (d->bd_async && d->bd_sig && d->bd_sigio)
500 pgsigio(d->bd_sigio, d->bd_sig, 0);
503 selwakeup(&d->bd_sel);
506 d->bd_sel.si_pid = 0;
510 bpf_timed_out(void *arg)
512 struct bpf_d *d = (struct bpf_d *)arg;
515 if (d->bd_state == BPF_WAITING) {
516 d->bd_state = BPF_TIMED_OUT;
524 bpf_output_dispatch(struct netmsg *nmsg)
526 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)nmsg;
527 struct ifnet *ifp = bmsg->nm_ifp;
531 * The driver frees the mbuf.
533 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
534 lwkt_replymsg(&nmsg->nm_lmsg, error);
538 bpfwrite(struct dev_write_args *ap)
540 cdev_t dev = ap->a_head.a_dev;
541 struct bpf_d *d = dev->si_drv1;
547 struct netmsg_bpf_output bmsg;
549 if (d->bd_bif == NULL)
552 ifp = d->bd_bif->bif_ifp;
554 if (ap->a_uio->uio_resid == 0)
557 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
558 &dst, &datlen, d->bd_wfilter);
562 if (datlen > ifp->if_mtu) {
568 dst.sa_family = pseudo_AF_HDRCMPLT;
570 netmsg_init(&bmsg.nm_netmsg, &curthread->td_msgport, MSGF_MPSAFE,
571 bpf_output_dispatch);
576 return lwkt_domsg(cpu_portfn(0), &bmsg.nm_netmsg.nm_lmsg, 0);
580 * Reset a descriptor by flushing its packet buffer and clearing the
581 * receive and drop counts. Should be called at splimp.
584 bpf_resetd(struct bpf_d *d)
587 /* Free the hold buffer. */
588 d->bd_fbuf = d->bd_hbuf;
598 * FIONREAD Check for read packet available.
599 * SIOCGIFADDR Get interface address - convenient hook to driver.
600 * BIOCGBLEN Get buffer len [for read()].
601 * BIOCSETF Set ethernet read filter.
602 * BIOCSETWF Set ethernet write filter.
603 * BIOCFLUSH Flush read packet buffer.
604 * BIOCPROMISC Put interface into promiscuous mode.
605 * BIOCGDLT Get link layer type.
606 * BIOCGETIF Get interface name.
607 * BIOCSETIF Set interface.
608 * BIOCSRTIMEOUT Set read timeout.
609 * BIOCGRTIMEOUT Get read timeout.
610 * BIOCGSTATS Get packet stats.
611 * BIOCIMMEDIATE Set immediate mode.
612 * BIOCVERSION Get filter language version.
613 * BIOCGHDRCMPLT Get "header already complete" flag
614 * BIOCSHDRCMPLT Set "header already complete" flag
615 * BIOCGSEESENT Get "see packets sent" flag
616 * BIOCSSEESENT Set "see packets sent" flag
617 * BIOCLOCK Set "locked" flag
621 bpfioctl(struct dev_ioctl_args *ap)
623 cdev_t dev = ap->a_head.a_dev;
624 struct bpf_d *d = dev->si_drv1;
628 if (d->bd_state == BPF_WAITING)
629 callout_stop(&d->bd_callout);
630 d->bd_state = BPF_IDLE;
633 if (d->bd_locked == 1) {
661 * Check for read packet available.
673 *(int *)ap->a_data = n;
681 if (d->bd_bif == NULL) {
684 ifp = d->bd_bif->bif_ifp;
685 ifnet_serialize_all(ifp);
686 error = ifp->if_ioctl(ifp, ap->a_cmd,
687 ap->a_data, ap->a_cred);
688 ifnet_deserialize_all(ifp);
694 * Get buffer len [for read()].
697 *(u_int *)ap->a_data = d->bd_bufsize;
704 if (d->bd_bif != NULL) {
707 u_int size = *(u_int *)ap->a_data;
709 if (size > bpf_maxbufsize)
710 *(u_int *)ap->a_data = size = bpf_maxbufsize;
711 else if (size < BPF_MINBUFSIZE)
712 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
713 d->bd_bufsize = size;
718 * Set link layer read filter.
722 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
727 * Flush read packet buffer.
736 * Put interface into promiscuous mode.
739 if (d->bd_bif == NULL) {
741 * No interface attached yet.
747 if (d->bd_promisc == 0) {
748 error = ifpromisc(d->bd_bif->bif_ifp, 1);
756 * Get device parameters.
759 if (d->bd_bif == NULL)
762 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
766 * Get a list of supported data link types.
769 if (d->bd_bif == NULL) {
772 error = bpf_getdltlist(d,
773 (struct bpf_dltlist *)ap->a_data);
778 * Set data link type.
781 if (d->bd_bif == NULL)
784 error = bpf_setdlt(d, *(u_int *)ap->a_data);
788 * Get interface name.
791 if (d->bd_bif == NULL) {
794 struct ifnet *const ifp = d->bd_bif->bif_ifp;
795 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
797 strlcpy(ifr->ifr_name, ifp->if_xname,
798 sizeof ifr->ifr_name);
806 error = bpf_setif(d, (struct ifreq *)ap->a_data);
814 struct timeval *tv = (struct timeval *)ap->a_data;
817 * Subtract 1 tick from tvtohz() since this isn't
820 if ((error = itimerfix(tv)) == 0)
821 d->bd_rtout = tvtohz_low(tv);
830 struct timeval *tv = (struct timeval *)ap->a_data;
832 tv->tv_sec = d->bd_rtout / hz;
833 tv->tv_usec = (d->bd_rtout % hz) * tick;
842 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
844 bs->bs_recv = d->bd_rcount;
845 bs->bs_drop = d->bd_dcount;
850 * Set immediate mode.
853 d->bd_immediate = *(u_int *)ap->a_data;
858 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
860 bv->bv_major = BPF_MAJOR_VERSION;
861 bv->bv_minor = BPF_MINOR_VERSION;
866 * Get "header already complete" flag
869 *(u_int *)ap->a_data = d->bd_hdrcmplt;
873 * Set "header already complete" flag
876 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
880 * Get "see sent packets" flag
883 *(u_int *)ap->a_data = d->bd_seesent;
887 * Set "see sent packets" flag
890 d->bd_seesent = *(u_int *)ap->a_data;
893 case FIOASYNC: /* Send signal on receive packets */
894 d->bd_async = *(int *)ap->a_data;
898 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
902 *(int *)ap->a_data = fgetown(d->bd_sigio);
905 /* This is deprecated, FIOSETOWN should be used instead. */
907 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
910 /* This is deprecated, FIOGETOWN should be used instead. */
912 *(int *)ap->a_data = -fgetown(d->bd_sigio);
915 case BIOCSRSIG: /* Set receive signal */
919 sig = *(u_int *)ap->a_data;
928 *(u_int *)ap->a_data = d->bd_sig;
938 * Set d's packet filter program to fp. If this file already has a filter,
939 * free it and replace it. Returns EINVAL for bogus requests.
942 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
944 struct bpf_insn *fcode, *old;
945 u_int wfilter, flen, size;
947 if (cmd == BIOCSETWF) {
954 if (fp->bf_insns == NULL) {
959 d->bd_wfilter = NULL;
961 d->bd_rfilter = NULL;
969 if (flen > BPF_MAXINSNS)
972 size = flen * sizeof *fp->bf_insns;
973 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
974 if (copyin(fp->bf_insns, fcode, size) == 0 &&
975 bpf_validate(fcode, (int)flen)) {
978 d->bd_wfilter = fcode;
980 d->bd_rfilter = fcode;
993 * Detach a file from its current interface (if attached at all) and attach
994 * to the interface indicated by the name stored in ifr.
995 * Return an errno or 0.
998 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1002 struct ifnet *theywant;
1004 theywant = ifunit(ifr->ifr_name);
1005 if (theywant == NULL)
1009 * Look through attached interfaces for the named one.
1011 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1012 struct ifnet *ifp = bp->bif_ifp;
1014 if (ifp == NULL || ifp != theywant)
1016 /* skip additional entry */
1017 if (bp->bif_driverp != &ifp->if_bpf)
1020 * We found the requested interface.
1021 * If it's not up, return an error.
1022 * Allocate the packet buffers if we need to.
1023 * If we're already attached to requested interface,
1024 * just flush the buffer.
1026 if (!(ifp->if_flags & IFF_UP))
1029 if (d->bd_sbuf == NULL) {
1030 error = bpf_allocbufs(d);
1035 if (bp != d->bd_bif) {
1036 if (d->bd_bif != NULL) {
1038 * Detach if attached to something else.
1055 * Support for select() and poll() system calls
1057 * Return true iff the specific operation will not block indefinitely.
1058 * Otherwise, return false but make a note that a selwakeup() must be done.
1061 bpfpoll(struct dev_poll_args *ap)
1063 cdev_t dev = ap->a_head.a_dev;
1068 if (d->bd_bif == NULL)
1071 revents = ap->a_events & (POLLOUT | POLLWRNORM);
1073 if (ap->a_events & (POLLIN | POLLRDNORM)) {
1075 * An imitation of the FIONREAD ioctl code.
1076 * XXX not quite. An exact imitation:
1077 * if (d->b_slen != 0 ||
1078 * (d->bd_hbuf != NULL && d->bd_hlen != 0)
1080 if (d->bd_hlen != 0 ||
1081 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1083 revents |= ap->a_events & (POLLIN | POLLRDNORM);
1085 selrecord(curthread, &d->bd_sel);
1086 /* Start the read timeout if necessary. */
1087 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1088 callout_reset(&d->bd_callout, d->bd_rtout,
1090 d->bd_state = BPF_WAITING;
1095 ap->a_events = revents;
1100 * Process the packet pkt of length pktlen. The packet is parsed
1101 * by each listener's filter, and if accepted, stashed into the
1102 * corresponding buffer.
1105 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1121 * Note that the ipl does not have to be raised at this point.
1122 * The only problem that could arise here is that if two different
1123 * interfaces shared any data. This is not the case.
1125 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1127 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1133 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv);
1141 * Copy data from an mbuf chain into a buffer. This code is derived
1142 * from m_copydata in sys/uipc_mbuf.c.
1145 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len)
1147 const struct mbuf *m;
1156 count = min(m->m_len, len);
1157 bcopy(mtod(m, void *), dst, count);
1165 * Process the packet in the mbuf chain m. The packet is parsed by each
1166 * listener's filter, and if accepted, stashed into the corresponding
1170 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1185 /* Don't compute pktlen, if no descriptor is attached. */
1186 if (SLIST_EMPTY(&bp->bif_dlist)) {
1191 pktlen = m_lengthm(m, NULL);
1193 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1194 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1197 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1203 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1212 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1216 KKASSERT(family != AF_UNSPEC);
1218 family4 = (u_int)family;
1219 bpf_ptap(bp, m, &family4, sizeof(family4));
1223 * Process the packet in the mbuf chain m with the header in m prepended.
1224 * The packet is parsed by each listener's filter, and if accepted,
1225 * stashed into the corresponding buffer.
1228 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1233 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1234 * Note that we cut corners here; we only setup what's
1235 * absolutely needed--this mbuf should never go anywhere else.
1238 mb.m_data = __DECONST(void *, data); /* LINTED */
1240 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1246 * Move the packet data from interface memory (pkt) into the
1247 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1248 * otherwise 0. "copy" is the routine called to do the actual data
1249 * transfer. bcopy is passed in to copy contiguous chunks, while
1250 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1251 * pkt is really an mbuf.
1254 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1255 void (*cpfn)(const void *, void *, size_t),
1256 const struct timeval *tv)
1260 int hdrlen = d->bd_bif->bif_hdrlen;
1262 * Figure out how many bytes to move. If the packet is
1263 * greater or equal to the snapshot length, transfer that
1264 * much. Otherwise, transfer the whole packet (unless
1265 * we hit the buffer size limit).
1267 totlen = hdrlen + min(snaplen, pktlen);
1268 if (totlen > d->bd_bufsize)
1269 totlen = d->bd_bufsize;
1272 * Round up the end of the previous packet to the next longword.
1274 curlen = BPF_WORDALIGN(d->bd_slen);
1275 if (curlen + totlen > d->bd_bufsize) {
1277 * This packet will overflow the storage buffer.
1278 * Rotate the buffers if we can, then wakeup any
1281 if (d->bd_fbuf == NULL) {
1283 * We haven't completed the previous read yet,
1284 * so drop the packet.
1292 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1294 * Immediate mode is set, or the read timeout has
1295 * already expired during a select call. A packet
1296 * arrived, so the reader should be woken up.
1302 * Append the bpf header.
1304 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1305 hp->bh_tstamp = *tv;
1306 hp->bh_datalen = pktlen;
1307 hp->bh_hdrlen = hdrlen;
1309 * Copy the packet data into the store buffer and update its length.
1311 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1312 d->bd_slen = curlen + totlen;
1316 * Initialize all nonzero fields of a descriptor.
1319 bpf_allocbufs(struct bpf_d *d)
1321 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1322 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1329 * Free buffers and packet filter program currently in use by a descriptor.
1333 bpf_freed(struct bpf_d *d)
1336 * We don't need to lock out interrupts since this descriptor has
1337 * been detached from its interface and it yet hasn't been marked
1340 if (d->bd_sbuf != NULL) {
1341 kfree(d->bd_sbuf, M_BPF);
1342 if (d->bd_hbuf != NULL)
1343 kfree(d->bd_hbuf, M_BPF);
1344 if (d->bd_fbuf != NULL)
1345 kfree(d->bd_fbuf, M_BPF);
1348 kfree(d->bd_rfilter, M_BPF);
1350 kfree(d->bd_wfilter, M_BPF);
1354 * Attach an interface to bpf. ifp is a pointer to the structure
1355 * defining the interface to be attached, dlt is the link layer type,
1356 * and hdrlen is the fixed size of the link header (variable length
1357 * headers are not yet supported).
1360 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1362 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1366 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1370 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1372 SLIST_INIT(&bp->bif_dlist);
1375 bp->bif_driverp = driverp;
1376 *bp->bif_driverp = NULL;
1378 bp->bif_next = bpf_iflist;
1382 * Compute the length of the bpf header. This is not necessarily
1383 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1384 * that the network layer header begins on a longword boundary (for
1385 * performance reasons and to alleviate alignment restrictions).
1387 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1390 if_printf(ifp, "bpf attached\n");
1394 * Detach bpf from an interface. This involves detaching each descriptor
1395 * associated with the interface, and leaving bd_bif NULL. Notify each
1396 * descriptor as it's detached so that any sleepers wake up and get
1400 bpfdetach(struct ifnet *ifp)
1402 struct bpf_if *bp, *bp_prev;
1407 /* Locate BPF interface information */
1409 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1410 if (ifp == bp->bif_ifp)
1415 /* Interface wasn't attached */
1416 if (bp->bif_ifp == NULL) {
1418 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1422 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1427 if (bp_prev != NULL)
1428 bp_prev->bif_next = bp->bif_next;
1430 bpf_iflist = bp->bif_next;
1438 * Get a list of available data link type of the interface.
1441 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1447 ifp = d->bd_bif->bif_ifp;
1450 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1451 if (bp->bif_ifp != ifp)
1453 if (bfl->bfl_list != NULL) {
1454 if (n >= bfl->bfl_len) {
1457 error = copyout(&bp->bif_dlt,
1458 bfl->bfl_list + n, sizeof(u_int));
1467 * Set the data link type of a BPF instance.
1470 bpf_setdlt(struct bpf_d *d, u_int dlt)
1472 int error, opromisc;
1476 if (d->bd_bif->bif_dlt == dlt)
1478 ifp = d->bd_bif->bif_ifp;
1479 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1480 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1484 opromisc = d->bd_promisc;
1490 error = ifpromisc(bp->bif_ifp, 1);
1492 if_printf(bp->bif_ifp,
1493 "bpf_setdlt: ifpromisc failed (%d)\n",
1501 return(bp == NULL ? EINVAL : 0);
1505 bpf_drvinit(void *unused)
1507 make_dev(&bpf_ops, 0, 0, 0, 0600, "bpf");
1508 devfs_clone_bitmap_init(&DEVFS_CLONE_BITMAP(bpf));
1509 devfs_clone_handler_add("bpf", bpfclone);
1513 bpf_drvuninit(void *unused)
1515 dev_ops_remove_all(&bpf_ops);
1516 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1519 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1520 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1524 * NOP stubs to allow bpf-using drivers to load and function.
1526 * A 'better' implementation would allow the core bpf functionality
1527 * to be loaded at runtime.
1531 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1536 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1541 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1546 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1551 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1556 bpfdetach(struct ifnet *ifp)
1561 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1563 return -1; /* "no filter" behaviour */