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 1.45 2008/05/14 11:59:23 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>
71 #include <netinet/in.h>
72 #include <netinet/if_ether.h>
73 #include <sys/kernel.h>
74 #include <sys/sysctl.h>
76 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
81 * The default read buffer size is patchable.
83 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
84 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
86 int bpf_maxbufsize = BPF_MAXBUFSIZE;
87 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
88 &bpf_maxbufsize, 0, "");
91 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
93 static struct bpf_if *bpf_iflist;
95 static int bpf_allocbufs(struct bpf_d *);
96 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
97 static void bpf_detachd(struct bpf_d *d);
98 static void bpf_resetd(struct bpf_d *);
99 static void bpf_freed(struct bpf_d *);
100 static void bpf_mcopy(const void *, void *, size_t);
101 static int bpf_movein(struct uio *, int, struct mbuf **,
102 struct sockaddr *, int *, struct bpf_insn *);
103 static int bpf_setif(struct bpf_d *, struct ifreq *);
104 static void bpf_timed_out(void *);
105 static void bpf_wakeup(struct bpf_d *);
106 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
107 void (*)(const void *, void *, size_t),
108 const struct timeval *);
109 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
110 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
111 static int bpf_setdlt(struct bpf_d *, u_int);
112 static void bpf_drvinit(void *unused);
114 static d_open_t bpfopen;
115 static d_close_t bpfclose;
116 static d_read_t bpfread;
117 static d_write_t bpfwrite;
118 static d_ioctl_t bpfioctl;
119 static d_poll_t bpfpoll;
121 #define CDEV_MAJOR 23
122 static struct dev_ops bpf_ops = {
123 { "bpf", CDEV_MAJOR, 0 },
134 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
135 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
147 * Build a sockaddr based on the data link layer type.
148 * We do this at this level because the ethernet header
149 * is copied directly into the data field of the sockaddr.
150 * In the case of SLIP, there is no header and the packet
151 * is forwarded as is.
152 * Also, we are careful to leave room at the front of the mbuf
153 * for the link level header.
157 sockp->sa_family = AF_INET;
162 sockp->sa_family = AF_UNSPEC;
163 /* XXX Would MAXLINKHDR be better? */
164 hlen = sizeof(struct ether_header);
169 sockp->sa_family = AF_UNSPEC;
173 case DLT_ATM_RFC1483:
175 * en atm driver requires 4-byte atm pseudo header.
176 * though it isn't standard, vpi:vci needs to be
179 sockp->sa_family = AF_UNSPEC;
180 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
184 sockp->sa_family = AF_UNSPEC;
185 hlen = 4; /* This should match PPP_HDRLEN */
192 len = uio->uio_resid;
193 *datlen = len - hlen;
194 if ((unsigned)len > MCLBYTES)
197 m = m_getl(len, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
200 m->m_pkthdr.len = m->m_len = len;
201 m->m_pkthdr.rcvif = NULL;
204 if (m->m_len < hlen) {
209 error = uiomove(mtod(m, u_char *), len, uio);
213 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
220 * Make room for link header, and copy it to sockaddr.
223 bcopy(m->m_data, sockp->sa_data, hlen);
224 m->m_pkthdr.len -= hlen;
226 m->m_data += hlen; /* XXX */
235 * Attach file to the bpf interface, i.e. make d listen on bp.
236 * Must be called at splimp.
239 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
242 * Point d at bp, and add d to the interface's list of listeners.
243 * Finally, point the driver's bpf cookie at the interface so
244 * it will divert packets to bpf.
247 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
248 *bp->bif_driverp = bp;
252 * Detach a file from its interface.
255 bpf_detachd(struct bpf_d *d)
264 /* Remove d from the interface's descriptor list. */
265 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
267 if (SLIST_EMPTY(&bp->bif_dlist)) {
269 * Let the driver know that there are no more listeners.
271 *bp->bif_driverp = NULL;
275 * Check if this descriptor had requested promiscuous mode.
276 * If so, turn it off.
280 error = ifpromisc(ifp, 0);
281 if (error != 0 && error != ENXIO) {
283 * ENXIO can happen if a pccard is unplugged,
284 * Something is really wrong if we were able to put
285 * the driver into promiscuous mode, but can't
288 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
295 * Open ethernet device. Returns ENXIO for illegal minor device number,
296 * EBUSY if file is open by another process.
300 bpfopen(struct dev_open_args *ap)
302 cdev_t dev = ap->a_head.a_dev;
305 if (ap->a_cred->cr_prison)
310 * Each minor can be opened by only one process. If the requested
311 * minor is in use, return EBUSY.
315 make_dev(&bpf_ops, minor(dev), 0, 0, 0600, "bpf%d", lminor(dev));
316 MALLOC(d, struct bpf_d *, sizeof *d, M_BPF, M_WAITOK | M_ZERO);
318 d->bd_bufsize = bpf_bufsize;
321 callout_init(&d->bd_callout);
326 * Close the descriptor by detaching it from its interface,
327 * deallocating its buffers, and marking it free.
331 bpfclose(struct dev_close_args *ap)
333 cdev_t dev = ap->a_head.a_dev;
334 struct bpf_d *d = dev->si_drv1;
336 funsetown(d->bd_sigio);
338 if (d->bd_state == BPF_WAITING)
339 callout_stop(&d->bd_callout);
340 d->bd_state = BPF_IDLE;
341 if (d->bd_bif != NULL)
352 * Rotate the packet buffers in descriptor d. Move the store buffer
353 * into the hold slot, and the free buffer into the store slot.
354 * Zero the length of the new store buffer.
356 #define ROTATE_BUFFERS(d) \
357 (d)->bd_hbuf = (d)->bd_sbuf; \
358 (d)->bd_hlen = (d)->bd_slen; \
359 (d)->bd_sbuf = (d)->bd_fbuf; \
363 * bpfread - read next chunk of packets from buffers
366 bpfread(struct dev_read_args *ap)
368 cdev_t dev = ap->a_head.a_dev;
369 struct bpf_d *d = dev->si_drv1;
374 * Restrict application to use a buffer the same size as
377 if (ap->a_uio->uio_resid != d->bd_bufsize)
381 if (d->bd_state == BPF_WAITING)
382 callout_stop(&d->bd_callout);
383 timed_out = (d->bd_state == BPF_TIMED_OUT);
384 d->bd_state = BPF_IDLE;
386 * If the hold buffer is empty, then do a timed sleep, which
387 * ends when the timeout expires or when enough packets
388 * have arrived to fill the store buffer.
390 while (d->bd_hbuf == NULL) {
391 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) {
393 * A packet(s) either arrived since the previous
394 * read or arrived while we were asleep.
395 * Rotate the buffers and return what's here.
402 * No data is available, check to see if the bpf device
403 * is still pointed at a real interface. If not, return
404 * ENXIO so that the userland process knows to rebind
405 * it before using it again.
407 if (d->bd_bif == NULL) {
412 if (ap->a_ioflag & IO_NDELAY) {
416 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
417 if (error == EINTR || error == ERESTART) {
421 if (error == EWOULDBLOCK) {
423 * On a timeout, return what's in the buffer,
424 * which may be nothing. If there is something
425 * in the store buffer, we can rotate the buffers.
429 * We filled up the buffer in between
430 * getting the timeout and arriving
431 * here, so we don't need to rotate.
435 if (d->bd_slen == 0) {
444 * At this point, we know we have something in the hold slot.
449 * Move data from hold buffer into user space.
450 * We know the entire buffer is transferred since
451 * we checked above that the read buffer is bpf_bufsize bytes.
453 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
456 d->bd_fbuf = d->bd_hbuf;
466 * If there are processes sleeping on this descriptor, wake them up.
469 bpf_wakeup(struct bpf_d *d)
471 if (d->bd_state == BPF_WAITING) {
472 callout_stop(&d->bd_callout);
473 d->bd_state = BPF_IDLE;
476 if (d->bd_async && d->bd_sig && d->bd_sigio)
477 pgsigio(d->bd_sigio, d->bd_sig, 0);
480 selwakeup(&d->bd_sel);
483 d->bd_sel.si_pid = 0;
487 bpf_timed_out(void *arg)
489 struct bpf_d *d = (struct bpf_d *)arg;
492 if (d->bd_state == BPF_WAITING) {
493 d->bd_state = BPF_TIMED_OUT;
501 bpfwrite(struct dev_write_args *ap)
503 cdev_t dev = ap->a_head.a_dev;
504 struct bpf_d *d = dev->si_drv1;
508 static struct sockaddr dst;
511 if (d->bd_bif == NULL)
514 ifp = d->bd_bif->bif_ifp;
516 if (ap->a_uio->uio_resid == 0)
519 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
520 &dst, &datlen, d->bd_wfilter);
524 if (datlen > ifp->if_mtu) {
530 dst.sa_family = pseudo_AF_HDRCMPLT;
533 error = ifp->if_output(ifp, m, &dst, NULL);
536 * The driver frees the mbuf.
542 * Reset a descriptor by flushing its packet buffer and clearing the
543 * receive and drop counts. Should be called at splimp.
546 bpf_resetd(struct bpf_d *d)
549 /* Free the hold buffer. */
550 d->bd_fbuf = d->bd_hbuf;
560 * FIONREAD Check for read packet available.
561 * SIOCGIFADDR Get interface address - convenient hook to driver.
562 * BIOCGBLEN Get buffer len [for read()].
563 * BIOCSETF Set ethernet read filter.
564 * BIOCSETWF Set ethernet write filter.
565 * BIOCFLUSH Flush read packet buffer.
566 * BIOCPROMISC Put interface into promiscuous mode.
567 * BIOCGDLT Get link layer type.
568 * BIOCGETIF Get interface name.
569 * BIOCSETIF Set interface.
570 * BIOCSRTIMEOUT Set read timeout.
571 * BIOCGRTIMEOUT Get read timeout.
572 * BIOCGSTATS Get packet stats.
573 * BIOCIMMEDIATE Set immediate mode.
574 * BIOCVERSION Get filter language version.
575 * BIOCGHDRCMPLT Get "header already complete" flag
576 * BIOCSHDRCMPLT Set "header already complete" flag
577 * BIOCGSEESENT Get "see packets sent" flag
578 * BIOCSSEESENT Set "see packets sent" flag
579 * BIOCLOCK Set "locked" flag
583 bpfioctl(struct dev_ioctl_args *ap)
585 cdev_t dev = ap->a_head.a_dev;
586 struct bpf_d *d = dev->si_drv1;
590 if (d->bd_state == BPF_WAITING)
591 callout_stop(&d->bd_callout);
592 d->bd_state = BPF_IDLE;
595 if (d->bd_locked == 1) {
623 * Check for read packet available.
635 *(int *)ap->a_data = n;
643 if (d->bd_bif == NULL) {
646 ifp = d->bd_bif->bif_ifp;
647 lwkt_serialize_enter(ifp->if_serializer);
648 error = ifp->if_ioctl(ifp, ap->a_cmd,
649 ap->a_data, ap->a_cred);
650 lwkt_serialize_exit(ifp->if_serializer);
656 * Get buffer len [for read()].
659 *(u_int *)ap->a_data = d->bd_bufsize;
666 if (d->bd_bif != NULL) {
669 u_int size = *(u_int *)ap->a_data;
671 if (size > bpf_maxbufsize)
672 *(u_int *)ap->a_data = size = bpf_maxbufsize;
673 else if (size < BPF_MINBUFSIZE)
674 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
675 d->bd_bufsize = size;
680 * Set link layer read filter.
684 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
689 * Flush read packet buffer.
698 * Put interface into promiscuous mode.
701 if (d->bd_bif == NULL) {
703 * No interface attached yet.
709 if (d->bd_promisc == 0) {
710 error = ifpromisc(d->bd_bif->bif_ifp, 1);
718 * Get device parameters.
721 if (d->bd_bif == NULL)
724 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
728 * Get a list of supported data link types.
731 if (d->bd_bif == NULL) {
734 error = bpf_getdltlist(d,
735 (struct bpf_dltlist *)ap->a_data);
740 * Set data link type.
743 if (d->bd_bif == NULL)
746 error = bpf_setdlt(d, *(u_int *)ap->a_data);
750 * Get interface name.
753 if (d->bd_bif == NULL) {
756 struct ifnet *const ifp = d->bd_bif->bif_ifp;
757 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
759 strlcpy(ifr->ifr_name, ifp->if_xname,
760 sizeof ifr->ifr_name);
768 error = bpf_setif(d, (struct ifreq *)ap->a_data);
776 struct timeval *tv = (struct timeval *)ap->a_data;
779 * Subtract 1 tick from tvtohz() since this isn't
782 if ((error = itimerfix(tv)) == 0)
783 d->bd_rtout = tvtohz_low(tv);
792 struct timeval *tv = (struct timeval *)ap->a_data;
794 tv->tv_sec = d->bd_rtout / hz;
795 tv->tv_usec = (d->bd_rtout % hz) * tick;
804 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
806 bs->bs_recv = d->bd_rcount;
807 bs->bs_drop = d->bd_dcount;
812 * Set immediate mode.
815 d->bd_immediate = *(u_int *)ap->a_data;
820 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
822 bv->bv_major = BPF_MAJOR_VERSION;
823 bv->bv_minor = BPF_MINOR_VERSION;
828 * Get "header already complete" flag
831 *(u_int *)ap->a_data = d->bd_hdrcmplt;
835 * Set "header already complete" flag
838 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
842 * Get "see sent packets" flag
845 *(u_int *)ap->a_data = d->bd_seesent;
849 * Set "see sent packets" flag
852 d->bd_seesent = *(u_int *)ap->a_data;
855 case FIOASYNC: /* Send signal on receive packets */
856 d->bd_async = *(int *)ap->a_data;
860 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
864 *(int *)ap->a_data = fgetown(d->bd_sigio);
867 /* This is deprecated, FIOSETOWN should be used instead. */
869 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
872 /* This is deprecated, FIOGETOWN should be used instead. */
874 *(int *)ap->a_data = -fgetown(d->bd_sigio);
877 case BIOCSRSIG: /* Set receive signal */
881 sig = *(u_int *)ap->a_data;
890 *(u_int *)ap->a_data = d->bd_sig;
900 * Set d's packet filter program to fp. If this file already has a filter,
901 * free it and replace it. Returns EINVAL for bogus requests.
904 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
906 struct bpf_insn *fcode, *old;
907 u_int wfilter, flen, size;
909 if (cmd == BIOCSETWF) {
916 if (fp->bf_insns == NULL) {
921 d->bd_wfilter = NULL;
923 d->bd_rfilter = NULL;
931 if (flen > BPF_MAXINSNS)
934 size = flen * sizeof *fp->bf_insns;
935 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
936 if (copyin(fp->bf_insns, fcode, size) == 0 &&
937 bpf_validate(fcode, (int)flen)) {
940 d->bd_wfilter = fcode;
942 d->bd_rfilter = fcode;
955 * Detach a file from its current interface (if attached at all) and attach
956 * to the interface indicated by the name stored in ifr.
957 * Return an errno or 0.
960 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
964 struct ifnet *theywant;
966 theywant = ifunit(ifr->ifr_name);
967 if (theywant == NULL)
971 * Look through attached interfaces for the named one.
973 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
974 struct ifnet *ifp = bp->bif_ifp;
976 if (ifp == NULL || ifp != theywant)
978 /* skip additional entry */
979 if (bp->bif_driverp != &ifp->if_bpf)
982 * We found the requested interface.
983 * If it's not up, return an error.
984 * Allocate the packet buffers if we need to.
985 * If we're already attached to requested interface,
986 * just flush the buffer.
988 if (!(ifp->if_flags & IFF_UP))
991 if (d->bd_sbuf == NULL) {
992 error = bpf_allocbufs(d);
997 if (bp != d->bd_bif) {
998 if (d->bd_bif != NULL) {
1000 * Detach if attached to something else.
1017 * Support for select() and poll() system calls
1019 * Return true iff the specific operation will not block indefinitely.
1020 * Otherwise, return false but make a note that a selwakeup() must be done.
1023 bpfpoll(struct dev_poll_args *ap)
1025 cdev_t dev = ap->a_head.a_dev;
1030 if (d->bd_bif == NULL)
1033 revents = ap->a_events & (POLLOUT | POLLWRNORM);
1035 if (ap->a_events & (POLLIN | POLLRDNORM)) {
1037 * An imitation of the FIONREAD ioctl code.
1038 * XXX not quite. An exact imitation:
1039 * if (d->b_slen != 0 ||
1040 * (d->bd_hbuf != NULL && d->bd_hlen != 0)
1042 if (d->bd_hlen != 0 ||
1043 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1045 revents |= ap->a_events & (POLLIN | POLLRDNORM);
1047 selrecord(curthread, &d->bd_sel);
1048 /* Start the read timeout if necessary. */
1049 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1050 callout_reset(&d->bd_callout, d->bd_rtout,
1052 d->bd_state = BPF_WAITING;
1057 ap->a_events = revents;
1062 * Process the packet pkt of length pktlen. The packet is parsed
1063 * by each listener's filter, and if accepted, stashed into the
1064 * corresponding buffer.
1067 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1075 * Note that the ipl does not have to be raised at this point.
1076 * The only problem that could arise here is that if two different
1077 * interfaces shared any data. This is not the case.
1079 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1081 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1087 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv);
1093 * Copy data from an mbuf chain into a buffer. This code is derived
1094 * from m_copydata in sys/uipc_mbuf.c.
1097 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len)
1099 const struct mbuf *m;
1108 count = min(m->m_len, len);
1109 bcopy(mtod(m, void *), dst, count);
1117 * Process the packet in the mbuf chain m. The packet is parsed by each
1118 * listener's filter, and if accepted, stashed into the corresponding
1122 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1129 /* Don't compute pktlen, if no descriptor is attached. */
1130 if (SLIST_EMPTY(&bp->bif_dlist))
1133 pktlen = m_lengthm(m, NULL);
1135 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1136 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1139 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1145 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1152 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1156 KKASSERT(family != AF_UNSPEC);
1158 family4 = (u_int)family;
1159 bpf_ptap(bp, m, &family4, sizeof(family4));
1163 * Process the packet in the mbuf chain m with the header in m prepended.
1164 * The packet is parsed by each listener's filter, and if accepted,
1165 * stashed into the corresponding buffer.
1168 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1173 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1174 * Note that we cut corners here; we only setup what's
1175 * absolutely needed--this mbuf should never go anywhere else.
1178 mb.m_data = __DECONST(void *, data); /* LINTED */
1180 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1186 * Move the packet data from interface memory (pkt) into the
1187 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1188 * otherwise 0. "copy" is the routine called to do the actual data
1189 * transfer. bcopy is passed in to copy contiguous chunks, while
1190 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1191 * pkt is really an mbuf.
1194 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1195 void (*cpfn)(const void *, void *, size_t),
1196 const struct timeval *tv)
1200 int hdrlen = d->bd_bif->bif_hdrlen;
1202 * Figure out how many bytes to move. If the packet is
1203 * greater or equal to the snapshot length, transfer that
1204 * much. Otherwise, transfer the whole packet (unless
1205 * we hit the buffer size limit).
1207 totlen = hdrlen + min(snaplen, pktlen);
1208 if (totlen > d->bd_bufsize)
1209 totlen = d->bd_bufsize;
1212 * Round up the end of the previous packet to the next longword.
1214 curlen = BPF_WORDALIGN(d->bd_slen);
1215 if (curlen + totlen > d->bd_bufsize) {
1217 * This packet will overflow the storage buffer.
1218 * Rotate the buffers if we can, then wakeup any
1221 if (d->bd_fbuf == NULL) {
1223 * We haven't completed the previous read yet,
1224 * so drop the packet.
1232 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1234 * Immediate mode is set, or the read timeout has
1235 * already expired during a select call. A packet
1236 * arrived, so the reader should be woken up.
1242 * Append the bpf header.
1244 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1245 hp->bh_tstamp = *tv;
1246 hp->bh_datalen = pktlen;
1247 hp->bh_hdrlen = hdrlen;
1249 * Copy the packet data into the store buffer and update its length.
1251 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1252 d->bd_slen = curlen + totlen;
1256 * Initialize all nonzero fields of a descriptor.
1259 bpf_allocbufs(struct bpf_d *d)
1261 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1262 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1269 * Free buffers and packet filter program currently in use by a descriptor.
1273 bpf_freed(struct bpf_d *d)
1276 * We don't need to lock out interrupts since this descriptor has
1277 * been detached from its interface and it yet hasn't been marked
1280 if (d->bd_sbuf != NULL) {
1281 kfree(d->bd_sbuf, M_BPF);
1282 if (d->bd_hbuf != NULL)
1283 kfree(d->bd_hbuf, M_BPF);
1284 if (d->bd_fbuf != NULL)
1285 kfree(d->bd_fbuf, M_BPF);
1288 kfree(d->bd_rfilter, M_BPF);
1290 kfree(d->bd_wfilter, M_BPF);
1294 * Attach an interface to bpf. ifp is a pointer to the structure
1295 * defining the interface to be attached, dlt is the link layer type,
1296 * and hdrlen is the fixed size of the link header (variable length
1297 * headers are not yet supported).
1300 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1302 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1306 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1310 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1312 SLIST_INIT(&bp->bif_dlist);
1315 bp->bif_driverp = driverp;
1316 *bp->bif_driverp = NULL;
1318 bp->bif_next = bpf_iflist;
1322 * Compute the length of the bpf header. This is not necessarily
1323 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1324 * that the network layer header begins on a longword boundary (for
1325 * performance reasons and to alleviate alignment restrictions).
1327 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1330 if_printf(ifp, "bpf attached\n");
1334 * Detach bpf from an interface. This involves detaching each descriptor
1335 * associated with the interface, and leaving bd_bif NULL. Notify each
1336 * descriptor as it's detached so that any sleepers wake up and get
1340 bpfdetach(struct ifnet *ifp)
1342 struct bpf_if *bp, *bp_prev;
1347 /* Locate BPF interface information */
1349 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1350 if (ifp == bp->bif_ifp)
1355 /* Interface wasn't attached */
1356 if (bp->bif_ifp == NULL) {
1358 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1362 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1367 if (bp_prev != NULL)
1368 bp_prev->bif_next = bp->bif_next;
1370 bpf_iflist = bp->bif_next;
1378 * Get a list of available data link type of the interface.
1381 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1387 ifp = d->bd_bif->bif_ifp;
1390 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1391 if (bp->bif_ifp != ifp)
1393 if (bfl->bfl_list != NULL) {
1394 if (n >= bfl->bfl_len) {
1397 error = copyout(&bp->bif_dlt,
1398 bfl->bfl_list + n, sizeof(u_int));
1407 * Set the data link type of a BPF instance.
1410 bpf_setdlt(struct bpf_d *d, u_int dlt)
1412 int error, opromisc;
1416 if (d->bd_bif->bif_dlt == dlt)
1418 ifp = d->bd_bif->bif_ifp;
1419 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1420 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1424 opromisc = d->bd_promisc;
1430 error = ifpromisc(bp->bif_ifp, 1);
1432 if_printf(bp->bif_ifp,
1433 "bpf_setdlt: ifpromisc failed (%d)\n",
1441 return(bp == NULL ? EINVAL : 0);
1445 bpf_drvinit(void *unused)
1447 dev_ops_add(&bpf_ops, 0, 0);
1450 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1454 * NOP stubs to allow bpf-using drivers to load and function.
1456 * A 'better' implementation would allow the core bpf functionality
1457 * to be loaded at runtime.
1461 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1466 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1471 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1476 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1481 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1486 bpfdetach(struct ifnet *ifp)
1491 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1493 return -1; /* "no filter" behaviour */