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 * $Id: bpf.c,v 1.51 1999/05/31 11:28:08 phk Exp $
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 #include "opt_devfs.h"
84 #include <sys/devfsext.h>
90 * Older BSDs don't have kernel malloc.
94 static caddr_t bpf_alloc();
95 #include <net/bpf_compat.h>
96 #define BPF_BUFSIZE (MCLBYTES-8)
97 #define UIOMOVE(cp, len, code, uio) uiomove(cp, len, code, uio)
99 #define BPF_BUFSIZE 4096
100 #define UIOMOVE(cp, len, code, uio) uiomove(cp, len, uio)
103 #define PRINET 26 /* interruptible */
106 * The default read buffer size is patchable.
108 static int bpf_bufsize = BPF_BUFSIZE;
109 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
110 &bpf_bufsize, 0, "");
113 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
114 * bpf_dtab holds the descriptors, indexed by minor device #
116 static struct bpf_if *bpf_iflist;
117 static struct bpf_d bpf_dtab[NBPF];
118 static int bpf_dtab_init;
120 static int bpf_allocbufs __P((struct bpf_d *));
121 static void bpf_attachd __P((struct bpf_d *d, struct bpf_if *bp));
122 static void bpf_detachd __P((struct bpf_d *d));
123 static void bpf_freed __P((struct bpf_d *));
124 static void bpf_ifname __P((struct ifnet *, struct ifreq *));
125 static void bpf_mcopy __P((const void *, void *, size_t));
126 static int bpf_movein __P((struct uio *, int,
127 struct mbuf **, struct sockaddr *, int *));
128 static int bpf_setif __P((struct bpf_d *, struct ifreq *));
130 bpf_wakeup __P((struct bpf_d *));
131 static void catchpacket __P((struct bpf_d *, u_char *, u_int,
132 u_int, void (*)(const void *, void *, size_t)));
133 static void reset_d __P((struct bpf_d *));
134 static int bpf_setf __P((struct bpf_d *, struct bpf_program *));
136 static d_open_t bpfopen;
137 static d_close_t bpfclose;
138 static d_read_t bpfread;
139 static d_write_t bpfwrite;
140 static d_ioctl_t bpfioctl;
141 static d_poll_t bpfpoll;
143 #define CDEV_MAJOR 23
144 static struct cdevsw bpf_cdevsw = {
146 /* close */ bpfclose,
148 /* write */ bpfwrite,
149 /* ioctl */ bpfioctl,
152 /* devtotty */ nodevtotty,
155 /* strategy */ nostrategy,
158 /* maj */ CDEV_MAJOR,
168 bpf_movein(uio, linktype, mp, sockp, datlen)
169 register struct uio *uio;
170 int linktype, *datlen;
171 register struct mbuf **mp;
172 register struct sockaddr *sockp;
180 * Build a sockaddr based on the data link layer type.
181 * We do this at this level because the ethernet header
182 * is copied directly into the data field of the sockaddr.
183 * In the case of SLIP, there is no header and the packet
184 * is forwarded as is.
185 * Also, we are careful to leave room at the front of the mbuf
186 * for the link level header.
191 sockp->sa_family = AF_INET;
196 sockp->sa_family = AF_UNSPEC;
197 /* XXX Would MAXLINKHDR be better? */
198 hlen = sizeof(struct ether_header);
202 #if defined(__FreeBSD__) || defined(__bsdi__)
203 sockp->sa_family = AF_IMPLINK;
206 sockp->sa_family = AF_UNSPEC;
207 /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */
214 sockp->sa_family = AF_UNSPEC;
219 case DLT_ATM_RFC1483:
221 * en atm driver requires 4-byte atm pseudo header.
222 * though it isn't standard, vpi:vci needs to be
225 sockp->sa_family = AF_UNSPEC;
226 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
234 len = uio->uio_resid;
235 *datlen = len - hlen;
236 if ((unsigned)len > MCLBYTES)
239 MGETHDR(m, M_WAIT, MT_DATA);
245 if ((m->m_flags & M_EXT) == 0) {
248 if (m->m_len != MCLBYTES) {
254 m->m_pkthdr.len = m->m_len = len;
255 m->m_pkthdr.rcvif = NULL;
258 * Make room for link header.
261 m->m_pkthdr.len -= hlen;
264 m->m_data += hlen; /* XXX */
268 error = UIOMOVE((caddr_t)sockp->sa_data, hlen, UIO_WRITE, uio);
272 error = UIOMOVE(mtod(m, caddr_t), len - hlen, UIO_WRITE, uio);
281 * Attach file to the bpf interface, i.e. make d listen on bp.
282 * Must be called at splimp.
290 * Point d at bp, and add d to the interface's list of listeners.
291 * Finally, point the driver's bpf cookie at the interface so
292 * it will divert packets to bpf.
295 d->bd_next = bp->bif_dlist;
298 bp->bif_ifp->if_bpf = bp;
302 * Detach a file from its interface.
313 * Check if this descriptor had requested promiscuous mode.
314 * If so, turn it off.
318 if (ifpromisc(bp->bif_ifp, 0))
320 * Something is really wrong if we were able to put
321 * the driver into promiscuous mode, but can't
324 panic("bpf: ifpromisc failed");
326 /* Remove d from the interface's descriptor list. */
331 panic("bpf_detachd: descriptor not in list");
334 if (bp->bif_dlist == 0)
336 * Let the driver know that there are no more listeners.
338 d->bd_bif->bif_ifp->if_bpf = 0;
344 * Mark a descriptor free by making it point to itself.
345 * This is probably cheaper than marking with a constant since
346 * the address should be in a register anyway.
348 #define D_ISFREE(d) ((d) == (d)->bd_next)
349 #define D_MARKFREE(d) ((d)->bd_next = (d))
350 #define D_MARKUSED(d) ((d)->bd_next = 0)
353 * Open ethernet device. Returns ENXIO for illegal minor device number,
354 * EBUSY if file is open by another process.
358 bpfopen(dev, flags, fmt, p)
364 register struct bpf_d *d;
369 if (minor(dev) >= NBPF)
372 * Each minor can be opened by only one process. If the requested
373 * minor is in use, return EBUSY.
375 d = &bpf_dtab[minor(dev)];
379 /* Mark "free" and do most initialization. */
380 bzero((char *)d, sizeof(*d));
381 d->bd_bufsize = bpf_bufsize;
388 * Close the descriptor by detaching it from its interface,
389 * deallocating its buffers, and marking it free.
393 bpfclose(dev, flags, fmt, p)
399 register struct bpf_d *d = &bpf_dtab[minor(dev)];
402 funsetown(d->bd_sigio);
413 * Support for SunOS, which does not have tsleep.
420 struct bpf_d *d = (struct bpf_d *)arg;
425 #define BPF_SLEEP(chan, pri, s, t) bpf_sleep((struct bpf_d *)chan)
429 register struct bpf_d *d;
431 register int rto = d->bd_rtout;
436 timeout(bpf_timeout, (caddr_t)d, rto);
438 st = sleep((caddr_t)d, PRINET|PCATCH);
440 if (d->bd_timedout == 0)
441 untimeout(bpf_timeout, (caddr_t)d);
445 return (st != 0) ? EINTR : 0;
448 #define BPF_SLEEP tsleep
452 * Rotate the packet buffers in descriptor d. Move the store buffer
453 * into the hold slot, and the free buffer into the store slot.
454 * Zero the length of the new store buffer.
456 #define ROTATE_BUFFERS(d) \
457 (d)->bd_hbuf = (d)->bd_sbuf; \
458 (d)->bd_hlen = (d)->bd_slen; \
459 (d)->bd_sbuf = (d)->bd_fbuf; \
463 * bpfread - read next chunk of packets from buffers
466 bpfread(dev, uio, ioflag)
468 register struct uio *uio;
471 register struct bpf_d *d = &bpf_dtab[minor(dev)];
476 * Restrict application to use a buffer the same size as
479 if (uio->uio_resid != d->bd_bufsize)
484 * If the hold buffer is empty, then do a timed sleep, which
485 * ends when the timeout expires or when enough packets
486 * have arrived to fill the store buffer.
488 while (d->bd_hbuf == 0) {
489 if (d->bd_immediate && d->bd_slen != 0) {
491 * A packet(s) either arrived since the previous
492 * read or arrived while we were asleep.
493 * Rotate the buffers and return what's here.
498 if (ioflag & IO_NDELAY)
501 error = BPF_SLEEP((caddr_t)d, PRINET|PCATCH, "bpf",
503 if (error == EINTR || error == ERESTART) {
507 if (error == EWOULDBLOCK) {
509 * On a timeout, return what's in the buffer,
510 * which may be nothing. If there is something
511 * in the store buffer, we can rotate the buffers.
515 * We filled up the buffer in between
516 * getting the timeout and arriving
517 * here, so we don't need to rotate.
521 if (d->bd_slen == 0) {
530 * At this point, we know we have something in the hold slot.
535 * Move data from hold buffer into user space.
536 * We know the entire buffer is transferred since
537 * we checked above that the read buffer is bpf_bufsize bytes.
539 error = UIOMOVE(d->bd_hbuf, d->bd_hlen, UIO_READ, uio);
542 d->bd_fbuf = d->bd_hbuf;
552 * If there are processes sleeping on this descriptor, wake them up.
556 register struct bpf_d *d;
559 if (d->bd_async && d->bd_sig && d->bd_sigio)
560 pgsigio(d->bd_sigio, d->bd_sig, 0);
563 selwakeup(&d->bd_sel);
565 d->bd_sel.si_pid = 0;
568 selwakeup(d->bd_selproc, (int)d->bd_selcoll);
576 bpfwrite(dev, uio, ioflag)
581 register struct bpf_d *d = &bpf_dtab[minor(dev)];
585 static struct sockaddr dst;
591 ifp = d->bd_bif->bif_ifp;
593 if (uio->uio_resid == 0)
596 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen);
600 if (datlen > ifp->if_mtu)
605 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0);
607 error = (*ifp->if_output)(ifp, m, &dst);
611 * The driver frees the mbuf.
617 * Reset a descriptor by flushing its packet buffer and clearing the
618 * receive and drop counts. Should be called at splimp.
625 /* Free the hold buffer. */
626 d->bd_fbuf = d->bd_hbuf;
636 * FIONREAD Check for read packet available.
637 * SIOCGIFADDR Get interface address - convenient hook to driver.
638 * BIOCGBLEN Get buffer len [for read()].
639 * BIOCSETF Set ethernet read filter.
640 * BIOCFLUSH Flush read packet buffer.
641 * BIOCPROMISC Put interface into promiscuous mode.
642 * BIOCGDLT Get link layer type.
643 * BIOCGETIF Get interface name.
644 * BIOCSETIF Set interface.
645 * BIOCSRTIMEOUT Set read timeout.
646 * BIOCGRTIMEOUT Get read timeout.
647 * BIOCGSTATS Get packet stats.
648 * BIOCIMMEDIATE Set immediate mode.
649 * BIOCVERSION Get filter language version.
653 bpfioctl(dev, cmd, addr, flags, p)
660 register struct bpf_d *d = &bpf_dtab[minor(dev)];
670 * Check for read packet available.
693 ifp = d->bd_bif->bif_ifp;
694 error = (*ifp->if_ioctl)(ifp, cmd, addr);
700 * Get buffer len [for read()].
703 *(u_int *)addr = d->bd_bufsize;
716 register u_int size = *(u_int *)addr;
718 if (size > BPF_MAXBUFSIZE)
719 *(u_int *)addr = size = BPF_MAXBUFSIZE;
720 else if (size < BPF_MINBUFSIZE)
721 *(u_int *)addr = size = BPF_MINBUFSIZE;
722 d->bd_bufsize = size;
728 * Set link layer read filter.
731 error = bpf_setf(d, (struct bpf_program *)addr);
735 * Flush read packet buffer.
744 * Put interface into promiscuous mode.
747 if (d->bd_bif == 0) {
749 * No interface attached yet.
755 if (d->bd_promisc == 0) {
756 error = ifpromisc(d->bd_bif->bif_ifp, 1);
764 * Get device parameters.
770 *(u_int *)addr = d->bd_bif->bif_dlt;
774 * Set interface name.
780 bpf_ifname(d->bd_bif->bif_ifp, (struct ifreq *)addr);
787 error = bpf_setif(d, (struct ifreq *)addr);
795 struct timeval *tv = (struct timeval *)addr;
798 * Subtract 1 tick from tvtohz() since this isn't
801 if ((error = itimerfix(tv)) == 0)
802 d->bd_rtout = tvtohz(tv) - 1;
811 struct timeval *tv = (struct timeval *)addr;
813 tv->tv_sec = d->bd_rtout / hz;
814 tv->tv_usec = (d->bd_rtout % hz) * tick;
823 struct bpf_stat *bs = (struct bpf_stat *)addr;
825 bs->bs_recv = d->bd_rcount;
826 bs->bs_drop = d->bd_dcount;
831 * Set immediate mode.
834 d->bd_immediate = *(u_int *)addr;
839 struct bpf_version *bv = (struct bpf_version *)addr;
841 bv->bv_major = BPF_MAJOR_VERSION;
842 bv->bv_minor = BPF_MINOR_VERSION;
846 case FIONBIO: /* Non-blocking I/O */
849 case FIOASYNC: /* Send signal on receive packets */
850 d->bd_async = *(int *)addr;
854 error = fsetown(*(int *)addr, &d->bd_sigio);
858 *(int *)addr = fgetown(d->bd_sigio);
861 /* This is deprecated, FIOSETOWN should be used instead. */
863 error = fsetown(-(*(int *)addr), &d->bd_sigio);
866 /* This is deprecated, FIOGETOWN should be used instead. */
868 *(int *)addr = -fgetown(d->bd_sigio);
871 case BIOCSRSIG: /* Set receive signal */
875 sig = *(u_int *)addr;
884 *(u_int *)addr = d->bd_sig;
891 * Set d's packet filter program to fp. If this file already has a filter,
892 * free it and replace it. Returns EINVAL for bogus requests.
897 struct bpf_program *fp;
899 struct bpf_insn *fcode, *old;
904 if (fp->bf_insns == 0) {
912 free((caddr_t)old, M_DEVBUF);
916 if (flen > BPF_MAXINSNS)
919 size = flen * sizeof(*fp->bf_insns);
920 fcode = (struct bpf_insn *)malloc(size, M_DEVBUF, M_WAITOK);
921 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 &&
922 bpf_validate(fcode, (int)flen)) {
924 d->bd_filter = fcode;
928 free((caddr_t)old, M_DEVBUF);
932 free((caddr_t)fcode, M_DEVBUF);
937 * Detach a file from its current interface (if attached at all) and attach
938 * to the interface indicated by the name stored in ifr.
939 * Return an errno or 0.
948 struct ifnet *theywant;
950 theywant = ifunit(ifr->ifr_name);
955 * Look through attached interfaces for the named one.
957 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
958 struct ifnet *ifp = bp->bif_ifp;
960 if (ifp == 0 || ifp != theywant)
963 * We found the requested interface.
964 * If it's not up, return an error.
965 * Allocate the packet buffers if we need to.
966 * If we're already attached to requested interface,
967 * just flush the buffer.
969 if ((ifp->if_flags & IFF_UP) == 0)
972 if (d->bd_sbuf == 0) {
973 error = bpf_allocbufs(d);
978 if (bp != d->bd_bif) {
981 * Detach if attached to something else.
996 * Convert an interface name plus unit number of an ifp to a single
997 * name which is returned in the ifr.
1000 bpf_ifname(ifp, ifr)
1004 char *s = ifp->if_name;
1005 char *d = ifr->ifr_name;
1007 while ((*d++ = *s++) != 0)
1009 d--; /* back to the null */
1010 /* XXX Assume that unit number is less than 10. */
1011 *d++ = ifp->if_unit + '0';
1016 * Support for select() and poll() system calls
1018 * Return true iff the specific operation will not block indefinitely.
1019 * Otherwise, return false but make a note that a selwakeup() must be done.
1022 bpfpoll(dev, events, p)
1027 register struct bpf_d *d;
1032 * An imitation of the FIONREAD ioctl code.
1034 d = &bpf_dtab[minor(dev)];
1037 if (events & (POLLIN | POLLRDNORM)) {
1038 if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0))
1039 revents |= events & (POLLIN | POLLRDNORM);
1041 selrecord(p, &d->bd_sel);
1048 * Incoming linkage from device drivers. Process the packet pkt, of length
1049 * pktlen, which is stored in a contiguous buffer. The packet is parsed
1050 * by each process' filter, and if accepted, stashed into the corresponding
1054 bpf_tap(ifp, pkt, pktlen)
1056 register u_char *pkt;
1057 register u_int pktlen;
1060 register struct bpf_d *d;
1061 register u_int slen;
1063 * Note that the ipl does not have to be raised at this point.
1064 * The only problem that could arise here is that if two different
1065 * interfaces shared any data. This is not the case.
1068 for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
1070 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
1072 catchpacket(d, pkt, pktlen, slen, bcopy);
1077 * Copy data from an mbuf chain into a buffer. This code is derived
1078 * from m_copydata in sys/uipc_mbuf.c.
1081 bpf_mcopy(src_arg, dst_arg, len)
1082 const void *src_arg;
1084 register size_t len;
1086 register const struct mbuf *m;
1087 register u_int count;
1095 count = min(m->m_len, len);
1096 bcopy(mtod(m, void *), dst, count);
1104 * Incoming linkage from device drivers, when packet is in an mbuf chain.
1111 struct bpf_if *bp = ifp->if_bpf;
1117 for (m0 = m; m0 != 0; m0 = m0->m_next)
1118 pktlen += m0->m_len;
1120 for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
1122 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0);
1124 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy);
1129 * Move the packet data from interface memory (pkt) into the
1130 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1131 * otherwise 0. "copy" is the routine called to do the actual data
1132 * transfer. bcopy is passed in to copy contiguous chunks, while
1133 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1134 * pkt is really an mbuf.
1137 catchpacket(d, pkt, pktlen, snaplen, cpfn)
1138 register struct bpf_d *d;
1139 register u_char *pkt;
1140 register u_int pktlen, snaplen;
1141 register void (*cpfn) __P((const void *, void *, size_t));
1143 register struct bpf_hdr *hp;
1144 register int totlen, curlen;
1145 register int hdrlen = d->bd_bif->bif_hdrlen;
1147 * Figure out how many bytes to move. If the packet is
1148 * greater or equal to the snapshot length, transfer that
1149 * much. Otherwise, transfer the whole packet (unless
1150 * we hit the buffer size limit).
1152 totlen = hdrlen + min(snaplen, pktlen);
1153 if (totlen > d->bd_bufsize)
1154 totlen = d->bd_bufsize;
1157 * Round up the end of the previous packet to the next longword.
1159 curlen = BPF_WORDALIGN(d->bd_slen);
1160 if (curlen + totlen > d->bd_bufsize) {
1162 * This packet will overflow the storage buffer.
1163 * Rotate the buffers if we can, then wakeup any
1166 if (d->bd_fbuf == 0) {
1168 * We haven't completed the previous read yet,
1169 * so drop the packet.
1178 else if (d->bd_immediate)
1180 * Immediate mode is set. A packet arrived so any
1181 * reads should be woken up.
1186 * Append the bpf header.
1188 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1190 microtime(&hp->bh_tstamp);
1192 uniqtime(&hp->bh_tstamp);
1194 hp->bh_tstamp = time;
1196 hp->bh_datalen = pktlen;
1197 hp->bh_hdrlen = hdrlen;
1199 * Copy the packet data into the store buffer and update its length.
1201 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1202 d->bd_slen = curlen + totlen;
1206 * Initialize all nonzero fields of a descriptor.
1210 register struct bpf_d *d;
1212 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK);
1213 if (d->bd_fbuf == 0)
1216 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK);
1217 if (d->bd_sbuf == 0) {
1218 free(d->bd_fbuf, M_DEVBUF);
1227 * Free buffers currently in use by a descriptor.
1232 register struct bpf_d *d;
1235 * We don't need to lock out interrupts since this descriptor has
1236 * been detached from its interface and it yet hasn't been marked
1239 if (d->bd_sbuf != 0) {
1240 free(d->bd_sbuf, M_DEVBUF);
1241 if (d->bd_hbuf != 0)
1242 free(d->bd_hbuf, M_DEVBUF);
1243 if (d->bd_fbuf != 0)
1244 free(d->bd_fbuf, M_DEVBUF);
1247 free((caddr_t)d->bd_filter, M_DEVBUF);
1253 * Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *)
1254 * in the driver's softc; dlt is the link layer type; hdrlen is the fixed
1255 * size of the link header (variable length headers not yet supported).
1258 bpfattach(ifp, dlt, hdrlen)
1264 bp = (struct bpf_if *)malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT);
1272 bp->bif_next = bpf_iflist;
1275 bp->bif_ifp->if_bpf = 0;
1278 * Compute the length of the bpf header. This is not necessarily
1279 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1280 * that the network layer header begins on a longword boundary (for
1281 * performance reasons and to alleviate alignment restrictions).
1283 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1286 * Mark all the descriptors free if this hasn't been done.
1288 if (!bpf_dtab_init) {
1289 for (i = 0; i < NBPF; ++i)
1290 D_MARKFREE(&bpf_dtab[i]);
1295 printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit);
1299 static void *bpf_devfs_token[NBPF];
1302 static int bpf_devsw_installed;
1304 static void bpf_drvinit __P((void *unused));
1313 if( ! bpf_devsw_installed ) {
1314 cdevsw_add(&bpf_cdevsw);
1315 bpf_devsw_installed = 1;
1318 for ( i = 0 ; i < NBPF ; i++ ) {
1319 bpf_devfs_token[i] =
1320 devfs_add_devswf(&bpf_cdevsw, i, DV_CHR, 0, 0,
1327 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1331 * NOP stubs to allow bpf-using drivers to load and function.
1333 * A 'better' implementation would allow the core bpf functionality
1334 * to be loaded at runtime.
1338 bpf_tap(ifp, pkt, pktlen)
1340 register u_char *pkt;
1341 register u_int pktlen;
1353 bpfattach(ifp, dlt, hdrlen)
1360 bpf_filter(pc, p, wirelen, buflen)
1361 register struct bpf_insn *pc;
1364 register u_int buflen;
1366 return -1; /* "no filter" behaviour */