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 8.4 (Berkeley) 1/9/95
45 #include "opt_netgraph.h"
47 #include <sys/param.h>
48 #include <sys/systm.h>
51 #include <sys/malloc.h>
55 #include <sys/signalvar.h>
56 #include <sys/filio.h>
57 #include <sys/sockio.h>
58 #include <sys/ttycom.h>
59 #include <sys/filedesc.h>
63 #include <sys/socket.h>
64 #include <sys/vnode.h>
68 #include <net/bpfdesc.h>
70 #include <netinet/in.h>
71 #include <netinet/if_ether.h>
72 #include <sys/kernel.h>
73 #include <sys/sysctl.h>
75 static MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
77 #if defined(DEV_BPF) || defined(NETGRAPH_BPF)
79 #define PRINET 26 /* interruptible */
82 * The default read buffer size is patchable.
84 static int bpf_bufsize = 4096;
85 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
87 static int bpf_maxbufsize = BPF_MAXBUFSIZE;
88 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
89 &bpf_maxbufsize, 0, "");
92 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
94 static struct bpf_if *bpf_iflist;
95 static struct mtx bpf_mtx; /* bpf global lock */
97 static int bpf_allocbufs(struct bpf_d *);
98 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
99 static void bpf_detachd(struct bpf_d *d);
100 static void bpf_freed(struct bpf_d *);
101 static void bpf_mcopy(const void *, void *, size_t);
102 static int bpf_movein(struct uio *, int,
103 struct mbuf **, struct sockaddr *, int *);
104 static int bpf_setif(struct bpf_d *, struct ifreq *);
105 static void bpf_timed_out(void *);
107 bpf_wakeup(struct bpf_d *);
108 static void catchpacket(struct bpf_d *, u_char *, u_int,
109 u_int, void (*)(const void *, void *, size_t));
110 static void reset_d(struct bpf_d *);
111 static int bpf_setf(struct bpf_d *, struct bpf_program *);
113 static d_open_t bpfopen;
114 static d_close_t bpfclose;
115 static d_read_t bpfread;
116 static d_write_t bpfwrite;
117 static d_ioctl_t bpfioctl;
118 static d_poll_t bpfpoll;
120 #define CDEV_MAJOR 23
121 static struct cdevsw bpf_cdevsw = {
123 /* close */ bpfclose,
125 /* write */ bpfwrite,
126 /* ioctl */ bpfioctl,
129 /* strategy */ nostrategy,
131 /* maj */ CDEV_MAJOR,
139 bpf_movein(uio, linktype, mp, sockp, datlen)
140 register struct uio *uio;
141 int linktype, *datlen;
142 register struct mbuf **mp;
143 register struct sockaddr *sockp;
151 * Build a sockaddr based on the data link layer type.
152 * We do this at this level because the ethernet header
153 * is copied directly into the data field of the sockaddr.
154 * In the case of SLIP, there is no header and the packet
155 * is forwarded as is.
156 * Also, we are careful to leave room at the front of the mbuf
157 * for the link level header.
162 sockp->sa_family = AF_INET;
167 sockp->sa_family = AF_UNSPEC;
168 /* XXX Would MAXLINKHDR be better? */
169 hlen = sizeof(struct ether_header);
173 sockp->sa_family = AF_IMPLINK;
179 sockp->sa_family = AF_UNSPEC;
183 case DLT_ATM_RFC1483:
185 * en atm driver requires 4-byte atm pseudo header.
186 * though it isn't standard, vpi:vci needs to be
189 sockp->sa_family = AF_UNSPEC;
190 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
194 sockp->sa_family = AF_UNSPEC;
195 hlen = 4; /* This should match PPP_HDRLEN */
202 len = uio->uio_resid;
203 *datlen = len - hlen;
204 if ((unsigned)len > MCLBYTES)
207 MGETHDR(m, M_TRYWAIT, MT_DATA);
211 MCLGET(m, M_TRYWAIT);
212 if ((m->m_flags & M_EXT) == 0) {
217 m->m_pkthdr.len = m->m_len = len;
218 m->m_pkthdr.rcvif = NULL;
221 * Make room for link header.
224 m->m_pkthdr.len -= hlen;
227 m->m_data += hlen; /* XXX */
231 error = uiomove((caddr_t)sockp->sa_data, hlen, uio);
235 error = uiomove(mtod(m, caddr_t), len - hlen, uio);
244 * Attach file to the bpf interface, i.e. make d listen on bp.
252 * Point d at bp, and add d to the interface's list of listeners.
253 * Finally, point the driver's bpf cookie at the interface so
254 * it will divert packets to bpf.
258 d->bd_next = bp->bif_dlist;
261 bp->bif_ifp->if_bpf = bp;
266 * Detach a file from its interface.
278 * Check if this descriptor had requested promiscuous mode.
279 * If so, turn it off.
283 error = ifpromisc(bp->bif_ifp, 0);
284 if (error != 0 && error != ENXIO) {
286 * ENXIO can happen if a pccard is unplugged
287 * Something is really wrong if we were able to put
288 * the driver into promiscuous mode, but can't
291 printf("%s%d: ifpromisc failed %d\n",
292 bp->bif_ifp->if_name, bp->bif_ifp->if_unit, error);
295 /* Remove d from the interface's descriptor list. */
301 panic("bpf_detachd: descriptor not in list");
304 if (bp->bif_dlist == 0)
306 * Let the driver know that there are no more listeners.
308 d->bd_bif->bif_ifp->if_bpf = 0;
314 * Open ethernet device. Returns ENXIO for illegal minor device number,
315 * EBUSY if file is open by another process.
319 bpfopen(dev, flags, fmt, td)
330 * Each minor can be opened by only one process. If the requested
331 * minor is in use, return EBUSY.
334 mtx_unlock(&bpf_mtx);
337 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */
338 mtx_unlock(&bpf_mtx);
340 if ((dev->si_flags & SI_NAMED) == 0)
341 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600,
342 "bpf%d", dev2unit(dev));
343 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
345 d->bd_bufsize = bpf_bufsize;
350 mac_create_bpfdesc(td->td_ucred, d);
352 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF);
353 callout_init(&d->bd_callout, 1);
359 * Close the descriptor by detaching it from its interface,
360 * deallocating its buffers, and marking it free.
364 bpfclose(dev, flags, fmt, td)
370 struct bpf_d *d = dev->si_drv1;
373 if (d->bd_state == BPF_WAITING)
374 callout_stop(&d->bd_callout);
375 d->bd_state = BPF_IDLE;
377 funsetown(&d->bd_sigio);
381 mtx_unlock(&bpf_mtx);
383 mac_destroy_bpfdesc(d);
394 * Rotate the packet buffers in descriptor d. Move the store buffer
395 * into the hold slot, and the free buffer into the store slot.
396 * Zero the length of the new store buffer.
398 #define ROTATE_BUFFERS(d) \
399 (d)->bd_hbuf = (d)->bd_sbuf; \
400 (d)->bd_hlen = (d)->bd_slen; \
401 (d)->bd_sbuf = (d)->bd_fbuf; \
405 * bpfread - read next chunk of packets from buffers
408 bpfread(dev, uio, ioflag)
410 register struct uio *uio;
413 struct bpf_d *d = dev->si_drv1;
418 * Restrict application to use a buffer the same size as
421 if (uio->uio_resid != d->bd_bufsize)
425 if (d->bd_state == BPF_WAITING)
426 callout_stop(&d->bd_callout);
427 timed_out = (d->bd_state == BPF_TIMED_OUT);
428 d->bd_state = BPF_IDLE;
430 * If the hold buffer is empty, then do a timed sleep, which
431 * ends when the timeout expires or when enough packets
432 * have arrived to fill the store buffer.
434 while (d->bd_hbuf == 0) {
435 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) {
437 * A packet(s) either arrived since the previous
438 * read or arrived while we were asleep.
439 * Rotate the buffers and return what's here.
446 * No data is available, check to see if the bpf device
447 * is still pointed at a real interface. If not, return
448 * ENXIO so that the userland process knows to rebind
449 * it before using it again.
451 if (d->bd_bif == NULL) {
456 if (ioflag & IO_NDELAY) {
458 return (EWOULDBLOCK);
460 error = msleep((caddr_t)d, &d->bd_mtx, PRINET|PCATCH,
462 if (error == EINTR || error == ERESTART) {
466 if (error == EWOULDBLOCK) {
468 * On a timeout, return what's in the buffer,
469 * which may be nothing. If there is something
470 * in the store buffer, we can rotate the buffers.
474 * We filled up the buffer in between
475 * getting the timeout and arriving
476 * here, so we don't need to rotate.
480 if (d->bd_slen == 0) {
489 * At this point, we know we have something in the hold slot.
494 * Move data from hold buffer into user space.
495 * We know the entire buffer is transferred since
496 * we checked above that the read buffer is bpf_bufsize bytes.
498 error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
501 d->bd_fbuf = d->bd_hbuf;
511 * If there are processes sleeping on this descriptor, wake them up.
515 register struct bpf_d *d;
517 if (d->bd_state == BPF_WAITING) {
518 callout_stop(&d->bd_callout);
519 d->bd_state = BPF_IDLE;
522 if (d->bd_async && d->bd_sig && d->bd_sigio)
523 pgsigio(&d->bd_sigio, d->bd_sig, 0);
525 selwakeup(&d->bd_sel);
532 struct bpf_d *d = (struct bpf_d *)arg;
535 if (d->bd_state == BPF_WAITING) {
536 d->bd_state = BPF_TIMED_OUT;
544 bpfwrite(dev, uio, ioflag)
549 struct bpf_d *d = dev->si_drv1;
553 static struct sockaddr dst;
559 ifp = d->bd_bif->bif_ifp;
561 if (uio->uio_resid == 0)
564 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen);
568 if (datlen > ifp->if_mtu)
572 dst.sa_family = pseudo_AF_HDRCMPLT;
576 mac_create_mbuf_from_bpfdesc(d, m);
578 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0);
581 * The driver frees the mbuf.
587 * Reset a descriptor by flushing its packet buffer and clearing the
588 * receive and drop counts.
595 mtx_assert(&d->bd_mtx, MA_OWNED);
597 /* Free the hold buffer. */
598 d->bd_fbuf = d->bd_hbuf;
608 * FIONREAD Check for read packet available.
609 * SIOCGIFADDR Get interface address - convenient hook to driver.
610 * BIOCGBLEN Get buffer len [for read()].
611 * BIOCSETF Set ethernet read filter.
612 * BIOCFLUSH Flush read packet buffer.
613 * BIOCPROMISC Put interface into promiscuous mode.
614 * BIOCGDLT Get link layer type.
615 * BIOCGETIF Get interface name.
616 * BIOCSETIF Set interface.
617 * BIOCSRTIMEOUT Set read timeout.
618 * BIOCGRTIMEOUT Get read timeout.
619 * BIOCGSTATS Get packet stats.
620 * BIOCIMMEDIATE Set immediate mode.
621 * BIOCVERSION Get filter language version.
622 * BIOCGHDRCMPLT Get "header already complete" flag
623 * BIOCSHDRCMPLT Set "header already complete" flag
624 * BIOCGSEESENT Get "see packets sent" flag
625 * BIOCSSEESENT Set "see packets sent" flag
629 bpfioctl(dev, cmd, addr, flags, td)
636 struct bpf_d *d = dev->si_drv1;
640 if (d->bd_state == BPF_WAITING)
641 callout_stop(&d->bd_callout);
642 d->bd_state = BPF_IDLE;
652 * Check for read packet available.
675 ifp = d->bd_bif->bif_ifp;
676 error = (*ifp->if_ioctl)(ifp, cmd, addr);
682 * Get buffer len [for read()].
685 *(u_int *)addr = d->bd_bufsize;
695 register u_int size = *(u_int *)addr;
697 if (size > bpf_maxbufsize)
698 *(u_int *)addr = size = bpf_maxbufsize;
699 else if (size < BPF_MINBUFSIZE)
700 *(u_int *)addr = size = BPF_MINBUFSIZE;
701 d->bd_bufsize = size;
706 * Set link layer read filter.
709 error = bpf_setf(d, (struct bpf_program *)addr);
713 * Flush read packet buffer.
722 * Put interface into promiscuous mode.
725 if (d->bd_bif == 0) {
727 * No interface attached yet.
732 if (d->bd_promisc == 0) {
734 error = ifpromisc(d->bd_bif->bif_ifp, 1);
742 * Get device parameters.
748 *(u_int *)addr = d->bd_bif->bif_dlt;
752 * Get interface name.
758 struct ifnet *const ifp = d->bd_bif->bif_ifp;
759 struct ifreq *const ifr = (struct ifreq *)addr;
761 snprintf(ifr->ifr_name, sizeof(ifr->ifr_name),
762 "%s%d", ifp->if_name, ifp->if_unit);
770 error = bpf_setif(d, (struct ifreq *)addr);
778 struct timeval *tv = (struct timeval *)addr;
781 * Subtract 1 tick from tvtohz() since this isn't
784 if ((error = itimerfix(tv)) == 0)
785 d->bd_rtout = tvtohz(tv) - 1;
794 struct timeval *tv = (struct timeval *)addr;
796 tv->tv_sec = d->bd_rtout / hz;
797 tv->tv_usec = (d->bd_rtout % hz) * tick;
806 struct bpf_stat *bs = (struct bpf_stat *)addr;
808 bs->bs_recv = d->bd_rcount;
809 bs->bs_drop = d->bd_dcount;
814 * Set immediate mode.
817 d->bd_immediate = *(u_int *)addr;
822 struct bpf_version *bv = (struct bpf_version *)addr;
824 bv->bv_major = BPF_MAJOR_VERSION;
825 bv->bv_minor = BPF_MINOR_VERSION;
830 * Get "header already complete" flag
833 *(u_int *)addr = d->bd_hdrcmplt;
837 * Set "header already complete" flag
840 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
844 * Get "see sent packets" flag
847 *(u_int *)addr = d->bd_seesent;
851 * Set "see sent packets" flag
854 d->bd_seesent = *(u_int *)addr;
857 case FIONBIO: /* Non-blocking I/O */
860 case FIOASYNC: /* Send signal on receive packets */
861 d->bd_async = *(int *)addr;
865 error = fsetown(*(int *)addr, &d->bd_sigio);
869 *(int *)addr = fgetown(&d->bd_sigio);
872 /* This is deprecated, FIOSETOWN should be used instead. */
874 error = fsetown(-(*(int *)addr), &d->bd_sigio);
877 /* This is deprecated, FIOGETOWN should be used instead. */
879 *(int *)addr = -fgetown(&d->bd_sigio);
882 case BIOCSRSIG: /* Set receive signal */
886 sig = *(u_int *)addr;
895 *(u_int *)addr = d->bd_sig;
902 * Set d's packet filter program to fp. If this file already has a filter,
903 * free it and replace it. Returns EINVAL for bogus requests.
908 struct bpf_program *fp;
910 struct bpf_insn *fcode, *old;
914 if (fp->bf_insns == 0) {
922 free((caddr_t)old, M_BPF);
926 if (flen > BPF_MAXINSNS)
929 size = flen * sizeof(*fp->bf_insns);
930 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK);
931 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 &&
932 bpf_validate(fcode, (int)flen)) {
934 d->bd_filter = fcode;
938 free((caddr_t)old, M_BPF);
942 free((caddr_t)fcode, M_BPF);
947 * Detach a file from its current interface (if attached at all) and attach
948 * to the interface indicated by the name stored in ifr.
949 * Return an errno or 0.
958 struct ifnet *theywant;
960 theywant = ifunit(ifr->ifr_name);
965 * Look through attached interfaces for the named one.
968 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
969 struct ifnet *ifp = bp->bif_ifp;
971 if (ifp == 0 || ifp != theywant)
974 mtx_unlock(&bpf_mtx);
976 * We found the requested interface.
977 * If it's not up, return an error.
978 * Allocate the packet buffers if we need to.
979 * If we're already attached to requested interface,
980 * just flush the buffer.
982 if ((ifp->if_flags & IFF_UP) == 0)
985 if (d->bd_sbuf == 0) {
986 error = bpf_allocbufs(d);
990 if (bp != d->bd_bif) {
993 * Detach if attached to something else.
1004 mtx_unlock(&bpf_mtx);
1010 * Support for select() and poll() system calls
1012 * Return true iff the specific operation will not block indefinitely.
1013 * Otherwise, return false but make a note that a selwakeup() must be done.
1016 bpfpoll(dev, events, td)
1025 if (d->bd_bif == NULL)
1028 revents = events & (POLLOUT | POLLWRNORM);
1030 if (events & (POLLIN | POLLRDNORM)) {
1032 * An imitation of the FIONREAD ioctl code.
1033 * XXX not quite. An exact imitation:
1034 * if (d->b_slen != 0 ||
1035 * (d->bd_hbuf != NULL && d->bd_hlen != 0)
1037 if (d->bd_hlen != 0 ||
1038 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1040 revents |= events & (POLLIN | POLLRDNORM);
1042 selrecord(td, &d->bd_sel);
1043 /* Start the read timeout if necessary. */
1044 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1045 callout_reset(&d->bd_callout, d->bd_rtout,
1047 d->bd_state = BPF_WAITING;
1056 * Incoming linkage from device drivers. Process the packet pkt, of length
1057 * pktlen, which is stored in a contiguous buffer. The packet is parsed
1058 * by each process' filter, and if accepted, stashed into the corresponding
1062 bpf_tap(ifp, pkt, pktlen)
1064 register u_char *pkt;
1065 register u_int pktlen;
1068 register struct bpf_d *d;
1069 register u_int slen;
1073 for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
1076 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
1079 if (mac_check_bpfdesc_receive(d, ifp) == 0)
1081 catchpacket(d, pkt, pktlen, slen, bcopy);
1089 * Copy data from an mbuf chain into a buffer. This code is derived
1090 * from m_copydata in sys/uipc_mbuf.c.
1093 bpf_mcopy(src_arg, dst_arg, len)
1094 const void *src_arg;
1096 register size_t len;
1098 register const struct mbuf *m;
1099 register u_int count;
1107 count = min(m->m_len, len);
1108 bcopy(mtod(m, void *), dst, count);
1116 * Incoming linkage from device drivers, when packet is in an mbuf chain.
1123 struct bpf_if *bp = ifp->if_bpf;
1127 pktlen = m_length(m, NULL);
1128 if (pktlen == m->m_len) {
1129 bpf_tap(ifp, mtod(m, u_char *), pktlen);
1134 for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
1135 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1139 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0);
1142 if (mac_check_bpfdesc_receive(d, ifp) == 0)
1144 catchpacket(d, (u_char *)m, pktlen, slen,
1152 * Move the packet data from interface memory (pkt) into the
1153 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1154 * otherwise 0. "copy" is the routine called to do the actual data
1155 * transfer. bcopy is passed in to copy contiguous chunks, while
1156 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1157 * pkt is really an mbuf.
1160 catchpacket(d, pkt, pktlen, snaplen, cpfn)
1161 register struct bpf_d *d;
1162 register u_char *pkt;
1163 register u_int pktlen, snaplen;
1164 register void (*cpfn)(const void *, void *, size_t);
1166 register struct bpf_hdr *hp;
1167 register int totlen, curlen;
1168 register int hdrlen = d->bd_bif->bif_hdrlen;
1170 * Figure out how many bytes to move. If the packet is
1171 * greater or equal to the snapshot length, transfer that
1172 * much. Otherwise, transfer the whole packet (unless
1173 * we hit the buffer size limit).
1175 totlen = hdrlen + min(snaplen, pktlen);
1176 if (totlen > d->bd_bufsize)
1177 totlen = d->bd_bufsize;
1180 * Round up the end of the previous packet to the next longword.
1182 curlen = BPF_WORDALIGN(d->bd_slen);
1183 if (curlen + totlen > d->bd_bufsize) {
1185 * This packet will overflow the storage buffer.
1186 * Rotate the buffers if we can, then wakeup any
1189 if (d->bd_fbuf == 0) {
1191 * We haven't completed the previous read yet,
1192 * so drop the packet.
1201 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT)
1203 * Immediate mode is set, or the read timeout has
1204 * already expired during a select call. A packet
1205 * arrived, so the reader should be woken up.
1210 * Append the bpf header.
1212 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1213 microtime(&hp->bh_tstamp);
1214 hp->bh_datalen = pktlen;
1215 hp->bh_hdrlen = hdrlen;
1217 * Copy the packet data into the store buffer and update its length.
1219 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1220 d->bd_slen = curlen + totlen;
1224 * Initialize all nonzero fields of a descriptor.
1228 register struct bpf_d *d;
1230 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
1231 if (d->bd_fbuf == 0)
1234 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
1235 if (d->bd_sbuf == 0) {
1236 free(d->bd_fbuf, M_BPF);
1245 * Free buffers currently in use by a descriptor.
1250 register struct bpf_d *d;
1253 * We don't need to lock out interrupts since this descriptor has
1254 * been detached from its interface and it yet hasn't been marked
1257 if (d->bd_sbuf != 0) {
1258 free(d->bd_sbuf, M_BPF);
1259 if (d->bd_hbuf != 0)
1260 free(d->bd_hbuf, M_BPF);
1261 if (d->bd_fbuf != 0)
1262 free(d->bd_fbuf, M_BPF);
1265 free((caddr_t)d->bd_filter, M_BPF);
1266 mtx_destroy(&d->bd_mtx);
1270 * Attach an interface to bpf. ifp is a pointer to the structure
1271 * defining the interface to be attached, dlt is the link layer type,
1272 * and hdrlen is the fixed size of the link header (variable length
1273 * headers are not yet supporrted).
1276 bpfattach(ifp, dlt, hdrlen)
1281 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
1287 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF);
1290 bp->bif_next = bpf_iflist;
1292 mtx_unlock(&bpf_mtx);
1294 bp->bif_ifp->if_bpf = 0;
1297 * Compute the length of the bpf header. This is not necessarily
1298 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1299 * that the network layer header begins on a longword boundary (for
1300 * performance reasons and to alleviate alignment restrictions).
1302 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1305 printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit);
1309 * Detach bpf from an interface. This involves detaching each descriptor
1310 * associated with the interface, and leaving bd_bif NULL. Notify each
1311 * descriptor as it's detached so that any sleepers wake up and get
1318 struct bpf_if *bp, *bp_prev;
1323 /* Locate BPF interface information */
1325 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1326 if (ifp == bp->bif_ifp)
1331 /* Interface wasn't attached */
1332 if (bp->bif_ifp == NULL) {
1333 mtx_unlock(&bpf_mtx);
1334 printf("bpfdetach: %s%d was not attached\n", ifp->if_name,
1340 bp_prev->bif_next = bp->bif_next;
1342 bpf_iflist = bp->bif_next;
1345 while ((d = bp->bif_dlist) != NULL) {
1352 mtx_destroy(&bp->bif_mtx);
1355 mtx_unlock(&bpf_mtx);
1358 static void bpf_drvinit(void *unused);
1360 static void bpf_clone(void *arg, char *name, int namelen, dev_t *dev);
1363 bpf_clone(arg, name, namelen, dev)
1373 if (dev_stdclone(name, NULL, "bpf", &u) != 1)
1375 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600,
1377 (*dev)->si_flags |= SI_CHEAPCLONE;
1386 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
1387 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000);
1388 cdevsw_add(&bpf_cdevsw);
1391 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1393 #else /* !DEV_BPF && !NETGRAPH_BPF */
1395 * NOP stubs to allow bpf-using drivers to load and function.
1397 * A 'better' implementation would allow the core bpf functionality
1398 * to be loaded at runtime.
1402 bpf_tap(ifp, pkt, pktlen)
1404 register u_char *pkt;
1405 register u_int pktlen;
1417 bpfattach(ifp, dlt, hdrlen)
1430 bpf_filter(pc, p, wirelen, buflen)
1431 register const struct bpf_insn *pc;
1434 register u_int buflen;
1436 return -1; /* "no filter" behaviour */
1440 bpf_validate(f, len)
1441 const struct bpf_insn *f;
1444 return 0; /* false */
1447 #endif /* !DEV_BPF && !NETGRAPH_BPF */