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
48 #define inline __inline
51 #include <sys/param.h>
52 #include <sys/systm.h>
54 #include <sys/malloc.h>
58 #include <sys/signalvar.h>
59 #include <sys/filio.h>
60 #include <sys/sockio.h>
61 #include <sys/ttycom.h>
62 #include <sys/filedesc.h>
64 #if defined(sparc) && BSD < 199103
65 #include <sys/stream.h>
69 #include <sys/socket.h>
70 #include <sys/vnode.h>
74 #include <net/bpfdesc.h>
76 #include <netinet/in.h>
77 #include <netinet/if_ether.h>
78 #include <sys/kernel.h>
79 #include <sys/sysctl.h>
81 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
86 * Older BSDs don't have kernel malloc.
90 static caddr_t bpf_alloc();
91 #include <net/bpf_compat.h>
92 #define BPF_BUFSIZE (MCLBYTES-8)
93 #define UIOMOVE(cp, len, code, uio) uiomove(cp, len, code, uio)
95 #define BPF_BUFSIZE 4096
96 #define UIOMOVE(cp, len, code, uio) uiomove(cp, len, uio)
99 #define PRINET 26 /* interruptible */
102 * The default read buffer size is patchable.
104 static int bpf_bufsize = BPF_BUFSIZE;
105 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
106 &bpf_bufsize, 0, "");
107 static int bpf_maxbufsize = BPF_MAXBUFSIZE;
108 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
109 &bpf_maxbufsize, 0, "");
112 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
114 static struct bpf_if *bpf_iflist;
116 static int bpf_allocbufs __P((struct bpf_d *));
117 static void bpf_attachd __P((struct bpf_d *d, struct bpf_if *bp));
118 static void bpf_detachd __P((struct bpf_d *d));
119 static void bpf_freed __P((struct bpf_d *));
120 static void bpf_mcopy __P((const void *, void *, size_t));
121 static int bpf_movein __P((struct uio *, int,
122 struct mbuf **, struct sockaddr *, int *));
123 static int bpf_setif __P((struct bpf_d *, struct ifreq *));
125 bpf_wakeup __P((struct bpf_d *));
126 static void catchpacket __P((struct bpf_d *, u_char *, u_int,
127 u_int, void (*)(const void *, void *, size_t)));
128 static void reset_d __P((struct bpf_d *));
129 static int bpf_setf __P((struct bpf_d *, struct bpf_program *));
131 static d_open_t bpfopen;
132 static d_close_t bpfclose;
133 static d_read_t bpfread;
134 static d_write_t bpfwrite;
135 static d_ioctl_t bpfioctl;
136 static d_poll_t bpfpoll;
138 #define CDEV_MAJOR 23
139 static struct cdevsw bpf_cdevsw = {
141 /* close */ bpfclose,
143 /* write */ bpfwrite,
144 /* ioctl */ bpfioctl,
147 /* strategy */ nostrategy,
149 /* maj */ CDEV_MAJOR,
158 bpf_movein(uio, linktype, mp, sockp, datlen)
159 register struct uio *uio;
160 int linktype, *datlen;
161 register struct mbuf **mp;
162 register struct sockaddr *sockp;
170 * Build a sockaddr based on the data link layer type.
171 * We do this at this level because the ethernet header
172 * is copied directly into the data field of the sockaddr.
173 * In the case of SLIP, there is no header and the packet
174 * is forwarded as is.
175 * Also, we are careful to leave room at the front of the mbuf
176 * for the link level header.
181 sockp->sa_family = AF_INET;
186 sockp->sa_family = AF_UNSPEC;
187 /* XXX Would MAXLINKHDR be better? */
188 hlen = sizeof(struct ether_header);
192 #if defined(__FreeBSD__) || defined(__bsdi__)
193 sockp->sa_family = AF_IMPLINK;
196 sockp->sa_family = AF_UNSPEC;
197 /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */
204 sockp->sa_family = AF_UNSPEC;
209 case DLT_ATM_RFC1483:
211 * en atm driver requires 4-byte atm pseudo header.
212 * though it isn't standard, vpi:vci needs to be
215 sockp->sa_family = AF_UNSPEC;
216 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
224 len = uio->uio_resid;
225 *datlen = len - hlen;
226 if ((unsigned)len > MCLBYTES)
229 MGETHDR(m, M_WAIT, MT_DATA);
235 if ((m->m_flags & M_EXT) == 0) {
238 if (m->m_len != MCLBYTES) {
244 m->m_pkthdr.len = m->m_len = len;
245 m->m_pkthdr.rcvif = NULL;
248 * Make room for link header.
251 m->m_pkthdr.len -= hlen;
254 m->m_data += hlen; /* XXX */
258 error = UIOMOVE((caddr_t)sockp->sa_data, hlen, UIO_WRITE, uio);
262 error = UIOMOVE(mtod(m, caddr_t), len - hlen, UIO_WRITE, uio);
271 * Attach file to the bpf interface, i.e. make d listen on bp.
272 * Must be called at splimp.
280 * Point d at bp, and add d to the interface's list of listeners.
281 * Finally, point the driver's bpf cookie at the interface so
282 * it will divert packets to bpf.
285 d->bd_next = bp->bif_dlist;
288 bp->bif_ifp->if_bpf = bp;
292 * Detach a file from its interface.
303 * Check if this descriptor had requested promiscuous mode.
304 * If so, turn it off.
308 if (ifpromisc(bp->bif_ifp, 0))
310 * Something is really wrong if we were able to put
311 * the driver into promiscuous mode, but can't
314 panic("bpf: ifpromisc failed");
316 /* Remove d from the interface's descriptor list. */
321 panic("bpf_detachd: descriptor not in list");
324 if (bp->bif_dlist == 0)
326 * Let the driver know that there are no more listeners.
328 d->bd_bif->bif_ifp->if_bpf = 0;
333 * Open ethernet device. Returns ENXIO for illegal minor device number,
334 * EBUSY if file is open by another process.
338 bpfopen(dev, flags, fmt, p)
344 register struct bpf_d *d;
351 * Each minor can be opened by only one process. If the requested
352 * minor is in use, return EBUSY.
356 make_dev(&bpf_cdevsw, minor(dev), 0, 0, 0600, "bpf%d", lminor(dev));
357 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK);
358 bzero(d, sizeof(*d));
360 d->bd_bufsize = bpf_bufsize;
368 * Close the descriptor by detaching it from its interface,
369 * deallocating its buffers, and marking it free.
373 bpfclose(dev, flags, fmt, p)
379 register struct bpf_d *d = dev->si_drv1;
382 funsetown(d->bd_sigio);
395 * Support for SunOS, which does not have tsleep.
402 struct bpf_d *d = (struct bpf_d *)arg;
407 #define BPF_SLEEP(chan, pri, s, t) bpf_sleep((struct bpf_d *)chan)
411 register struct bpf_d *d;
413 register int rto = d->bd_rtout;
418 timeout(bpf_timeout, (caddr_t)d, rto);
420 st = sleep((caddr_t)d, PRINET|PCATCH);
422 if (d->bd_timedout == 0)
423 untimeout(bpf_timeout, (caddr_t)d);
427 return (st != 0) ? EINTR : 0;
430 #define BPF_SLEEP tsleep
434 * Rotate the packet buffers in descriptor d. Move the store buffer
435 * into the hold slot, and the free buffer into the store slot.
436 * Zero the length of the new store buffer.
438 #define ROTATE_BUFFERS(d) \
439 (d)->bd_hbuf = (d)->bd_sbuf; \
440 (d)->bd_hlen = (d)->bd_slen; \
441 (d)->bd_sbuf = (d)->bd_fbuf; \
445 * bpfread - read next chunk of packets from buffers
448 bpfread(dev, uio, ioflag)
450 register struct uio *uio;
453 register struct bpf_d *d = dev->si_drv1;
458 * Restrict application to use a buffer the same size as
461 if (uio->uio_resid != d->bd_bufsize)
466 * If the hold buffer is empty, then do a timed sleep, which
467 * ends when the timeout expires or when enough packets
468 * have arrived to fill the store buffer.
470 while (d->bd_hbuf == 0) {
471 if (d->bd_immediate && d->bd_slen != 0) {
473 * A packet(s) either arrived since the previous
474 * read or arrived while we were asleep.
475 * Rotate the buffers and return what's here.
482 * No data is available, check to see if the bpf device
483 * is still pointed at a real interface. If not, return
484 * ENXIO so that the userland process knows to rebind
485 * it before using it again.
487 if (d->bd_bif == NULL) {
492 if (ioflag & IO_NDELAY)
495 error = BPF_SLEEP((caddr_t)d, PRINET|PCATCH, "bpf",
497 if (error == EINTR || error == ERESTART) {
501 if (error == EWOULDBLOCK) {
503 * On a timeout, return what's in the buffer,
504 * which may be nothing. If there is something
505 * in the store buffer, we can rotate the buffers.
509 * We filled up the buffer in between
510 * getting the timeout and arriving
511 * here, so we don't need to rotate.
515 if (d->bd_slen == 0) {
524 * At this point, we know we have something in the hold slot.
529 * Move data from hold buffer into user space.
530 * We know the entire buffer is transferred since
531 * we checked above that the read buffer is bpf_bufsize bytes.
533 error = UIOMOVE(d->bd_hbuf, d->bd_hlen, UIO_READ, uio);
536 d->bd_fbuf = d->bd_hbuf;
546 * If there are processes sleeping on this descriptor, wake them up.
550 register struct bpf_d *d;
553 if (d->bd_async && d->bd_sig && d->bd_sigio)
554 pgsigio(d->bd_sigio, d->bd_sig, 0);
557 selwakeup(&d->bd_sel);
559 d->bd_sel.si_pid = 0;
562 selwakeup(d->bd_selproc, (int)d->bd_selcoll);
570 bpfwrite(dev, uio, ioflag)
575 register struct bpf_d *d = dev->si_drv1;
579 static struct sockaddr dst;
585 ifp = d->bd_bif->bif_ifp;
587 if (uio->uio_resid == 0)
590 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen);
594 if (datlen > ifp->if_mtu)
598 dst.sa_family = pseudo_AF_HDRCMPLT;
602 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0);
604 error = (*ifp->if_output)(ifp, m, &dst);
608 * The driver frees the mbuf.
614 * Reset a descriptor by flushing its packet buffer and clearing the
615 * receive and drop counts. Should be called at splimp.
622 /* Free the hold buffer. */
623 d->bd_fbuf = d->bd_hbuf;
633 * FIONREAD Check for read packet available.
634 * SIOCGIFADDR Get interface address - convenient hook to driver.
635 * BIOCGBLEN Get buffer len [for read()].
636 * BIOCSETF Set ethernet read filter.
637 * BIOCFLUSH Flush read packet buffer.
638 * BIOCPROMISC Put interface into promiscuous mode.
639 * BIOCGDLT Get link layer type.
640 * BIOCGETIF Get interface name.
641 * BIOCSETIF Set interface.
642 * BIOCSRTIMEOUT Set read timeout.
643 * BIOCGRTIMEOUT Get read timeout.
644 * BIOCGSTATS Get packet stats.
645 * BIOCIMMEDIATE Set immediate mode.
646 * BIOCVERSION Get filter language version.
647 * BIOCGHDRCMPLT Get "header already complete" flag
648 * BIOCSHDRCMPLT Set "header already complete" flag
649 * BIOCGSEESENT Get "see packets sent" flag
650 * BIOCSSEESENT Set "see packets sent" flag
654 bpfioctl(dev, cmd, addr, flags, p)
661 register struct bpf_d *d = dev->si_drv1;
671 * Check for read packet available.
694 ifp = d->bd_bif->bif_ifp;
695 error = (*ifp->if_ioctl)(ifp, cmd, addr);
701 * Get buffer len [for read()].
704 *(u_int *)addr = d->bd_bufsize;
717 register u_int size = *(u_int *)addr;
719 if (size > bpf_maxbufsize)
720 *(u_int *)addr = size = bpf_maxbufsize;
721 else if (size < BPF_MINBUFSIZE)
722 *(u_int *)addr = size = BPF_MINBUFSIZE;
723 d->bd_bufsize = size;
729 * Set link layer read filter.
732 error = bpf_setf(d, (struct bpf_program *)addr);
736 * Flush read packet buffer.
745 * Put interface into promiscuous mode.
748 if (d->bd_bif == 0) {
750 * No interface attached yet.
756 if (d->bd_promisc == 0) {
757 error = ifpromisc(d->bd_bif->bif_ifp, 1);
765 * Get device parameters.
771 *(u_int *)addr = d->bd_bif->bif_dlt;
775 * Get interface name.
781 struct ifnet *const ifp = d->bd_bif->bif_ifp;
782 struct ifreq *const ifr = (struct ifreq *)addr;
784 snprintf(ifr->ifr_name, sizeof(ifr->ifr_name),
785 "%s%d", ifp->if_name, ifp->if_unit);
793 error = bpf_setif(d, (struct ifreq *)addr);
801 struct timeval *tv = (struct timeval *)addr;
804 * Subtract 1 tick from tvtohz() since this isn't
807 if ((error = itimerfix(tv)) == 0)
808 d->bd_rtout = tvtohz(tv) - 1;
817 struct timeval *tv = (struct timeval *)addr;
819 tv->tv_sec = d->bd_rtout / hz;
820 tv->tv_usec = (d->bd_rtout % hz) * tick;
829 struct bpf_stat *bs = (struct bpf_stat *)addr;
831 bs->bs_recv = d->bd_rcount;
832 bs->bs_drop = d->bd_dcount;
837 * Set immediate mode.
840 d->bd_immediate = *(u_int *)addr;
845 struct bpf_version *bv = (struct bpf_version *)addr;
847 bv->bv_major = BPF_MAJOR_VERSION;
848 bv->bv_minor = BPF_MINOR_VERSION;
853 * Get "header already complete" flag
856 *(u_int *)addr = d->bd_hdrcmplt;
860 * Set "header already complete" flag
863 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
867 * Get "see sent packets" flag
870 *(u_int *)addr = d->bd_seesent;
874 * Set "see sent packets" flag
877 d->bd_seesent = *(u_int *)addr;
880 case FIONBIO: /* Non-blocking I/O */
883 case FIOASYNC: /* Send signal on receive packets */
884 d->bd_async = *(int *)addr;
888 error = fsetown(*(int *)addr, &d->bd_sigio);
892 *(int *)addr = fgetown(d->bd_sigio);
895 /* This is deprecated, FIOSETOWN should be used instead. */
897 error = fsetown(-(*(int *)addr), &d->bd_sigio);
900 /* This is deprecated, FIOGETOWN should be used instead. */
902 *(int *)addr = -fgetown(d->bd_sigio);
905 case BIOCSRSIG: /* Set receive signal */
909 sig = *(u_int *)addr;
918 *(u_int *)addr = d->bd_sig;
925 * Set d's packet filter program to fp. If this file already has a filter,
926 * free it and replace it. Returns EINVAL for bogus requests.
931 struct bpf_program *fp;
933 struct bpf_insn *fcode, *old;
938 if (fp->bf_insns == 0) {
946 free((caddr_t)old, M_BPF);
950 if (flen > BPF_MAXINSNS)
953 size = flen * sizeof(*fp->bf_insns);
954 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK);
955 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 &&
956 bpf_validate(fcode, (int)flen)) {
958 d->bd_filter = fcode;
962 free((caddr_t)old, M_BPF);
966 free((caddr_t)fcode, M_BPF);
971 * Detach a file from its current interface (if attached at all) and attach
972 * to the interface indicated by the name stored in ifr.
973 * Return an errno or 0.
982 struct ifnet *theywant;
984 theywant = ifunit(ifr->ifr_name);
989 * Look through attached interfaces for the named one.
991 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
992 struct ifnet *ifp = bp->bif_ifp;
994 if (ifp == 0 || ifp != theywant)
997 * We found the requested interface.
998 * If it's not up, return an error.
999 * Allocate the packet buffers if we need to.
1000 * If we're already attached to requested interface,
1001 * just flush the buffer.
1003 if ((ifp->if_flags & IFF_UP) == 0)
1006 if (d->bd_sbuf == 0) {
1007 error = bpf_allocbufs(d);
1012 if (bp != d->bd_bif) {
1015 * Detach if attached to something else.
1030 * Support for select() and poll() system calls
1032 * Return true iff the specific operation will not block indefinitely.
1033 * Otherwise, return false but make a note that a selwakeup() must be done.
1036 bpfpoll(dev, events, p)
1041 register struct bpf_d *d;
1046 * An imitation of the FIONREAD ioctl code.
1050 if (d->bd_bif == NULL)
1054 if (events & (POLLIN | POLLRDNORM)) {
1055 if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0))
1056 revents |= events & (POLLIN | POLLRDNORM);
1058 selrecord(p, &d->bd_sel);
1065 * Incoming linkage from device drivers. Process the packet pkt, of length
1066 * pktlen, which is stored in a contiguous buffer. The packet is parsed
1067 * by each process' filter, and if accepted, stashed into the corresponding
1071 bpf_tap(ifp, pkt, pktlen)
1073 register u_char *pkt;
1074 register u_int pktlen;
1077 register struct bpf_d *d;
1078 register u_int slen;
1080 * Note that the ipl does not have to be raised at this point.
1081 * The only problem that could arise here is that if two different
1082 * interfaces shared any data. This is not the case.
1085 for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
1087 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
1089 catchpacket(d, pkt, pktlen, slen, bcopy);
1094 * Copy data from an mbuf chain into a buffer. This code is derived
1095 * from m_copydata in sys/uipc_mbuf.c.
1098 bpf_mcopy(src_arg, dst_arg, len)
1099 const void *src_arg;
1101 register size_t len;
1103 register const struct mbuf *m;
1104 register u_int count;
1112 count = min(m->m_len, len);
1113 bcopy(mtod(m, void *), dst, count);
1121 * Incoming linkage from device drivers, when packet is in an mbuf chain.
1128 struct bpf_if *bp = ifp->if_bpf;
1134 for (m0 = m; m0 != 0; m0 = m0->m_next)
1135 pktlen += m0->m_len;
1137 for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
1138 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1141 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0);
1143 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy);
1148 * Move the packet data from interface memory (pkt) into the
1149 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1150 * otherwise 0. "copy" is the routine called to do the actual data
1151 * transfer. bcopy is passed in to copy contiguous chunks, while
1152 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1153 * pkt is really an mbuf.
1156 catchpacket(d, pkt, pktlen, snaplen, cpfn)
1157 register struct bpf_d *d;
1158 register u_char *pkt;
1159 register u_int pktlen, snaplen;
1160 register void (*cpfn) __P((const void *, void *, size_t));
1162 register struct bpf_hdr *hp;
1163 register int totlen, curlen;
1164 register int hdrlen = d->bd_bif->bif_hdrlen;
1166 * Figure out how many bytes to move. If the packet is
1167 * greater or equal to the snapshot length, transfer that
1168 * much. Otherwise, transfer the whole packet (unless
1169 * we hit the buffer size limit).
1171 totlen = hdrlen + min(snaplen, pktlen);
1172 if (totlen > d->bd_bufsize)
1173 totlen = d->bd_bufsize;
1176 * Round up the end of the previous packet to the next longword.
1178 curlen = BPF_WORDALIGN(d->bd_slen);
1179 if (curlen + totlen > d->bd_bufsize) {
1181 * This packet will overflow the storage buffer.
1182 * Rotate the buffers if we can, then wakeup any
1185 if (d->bd_fbuf == 0) {
1187 * We haven't completed the previous read yet,
1188 * so drop the packet.
1197 else if (d->bd_immediate)
1199 * Immediate mode is set. A packet arrived so any
1200 * reads should be woken up.
1205 * Append the bpf header.
1207 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1209 microtime(&hp->bh_tstamp);
1211 uniqtime(&hp->bh_tstamp);
1213 hp->bh_tstamp = time;
1215 hp->bh_datalen = pktlen;
1216 hp->bh_hdrlen = hdrlen;
1218 * Copy the packet data into the store buffer and update its length.
1220 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1221 d->bd_slen = curlen + totlen;
1225 * Initialize all nonzero fields of a descriptor.
1229 register struct bpf_d *d;
1231 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
1232 if (d->bd_fbuf == 0)
1235 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
1236 if (d->bd_sbuf == 0) {
1237 free(d->bd_fbuf, M_BPF);
1246 * Free buffers currently in use by a descriptor.
1251 register struct bpf_d *d;
1254 * We don't need to lock out interrupts since this descriptor has
1255 * been detached from its interface and it yet hasn't been marked
1258 if (d->bd_sbuf != 0) {
1259 free(d->bd_sbuf, M_BPF);
1260 if (d->bd_hbuf != 0)
1261 free(d->bd_hbuf, M_BPF);
1262 if (d->bd_fbuf != 0)
1263 free(d->bd_fbuf, M_BPF);
1266 free((caddr_t)d->bd_filter, M_BPF);
1270 * Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *)
1271 * in the driver's softc; dlt is the link layer type; hdrlen is the fixed
1272 * size of the link header (variable length headers not yet supported).
1275 bpfattach(ifp, dlt, hdrlen)
1280 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_DONTWAIT);
1288 bp->bif_next = bpf_iflist;
1291 bp->bif_ifp->if_bpf = 0;
1294 * Compute the length of the bpf header. This is not necessarily
1295 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1296 * that the network layer header begins on a longword boundary (for
1297 * performance reasons and to alleviate alignment restrictions).
1299 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1302 printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit);
1306 * Detach bpf from an interface. This involves detaching each descriptor
1307 * associated with the interface, and leaving bd_bif NULL. Notify each
1308 * descriptor as it's detached so that any sleepers wake up and get
1315 struct bpf_if *bp, *bp_prev;
1321 /* Locate BPF interface information */
1323 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1324 if (ifp == bp->bif_ifp)
1329 /* Interface wasn't attached */
1330 if (bp->bif_ifp == NULL) {
1332 printf("bpfdetach: %s%d was not attached\n", ifp->if_name,
1337 while ((d = bp->bif_dlist) != NULL) {
1343 bp_prev->bif_next = bp->bif_next;
1345 bpf_iflist = bp->bif_next;
1353 static void bpf_drvinit __P((void *unused));
1360 cdevsw_add(&bpf_cdevsw);
1363 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1367 * NOP stubs to allow bpf-using drivers to load and function.
1369 * A 'better' implementation would allow the core bpf functionality
1370 * to be loaded at runtime.
1374 bpf_tap(ifp, pkt, pktlen)
1376 register u_char *pkt;
1377 register u_int pktlen;
1389 bpfattach(ifp, dlt, hdrlen)
1396 bpf_filter(pc, p, wirelen, buflen)
1397 register const struct bpf_insn *pc;
1400 register u_int buflen;
1402 return -1; /* "no filter" behaviour */