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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#)bpf.c 8.2 (Berkeley) 3/28/94
36 * $FreeBSD: src/sys/net/bpf.c,v 1.59.2.12 2002/04/14 21:41:48 luigi Exp $
41 #include <sys/param.h>
42 #include <sys/systm.h>
44 #include <sys/device.h>
45 #include <sys/malloc.h>
49 #include <sys/signalvar.h>
50 #include <sys/filio.h>
51 #include <sys/sockio.h>
52 #include <sys/ttycom.h>
53 #include <sys/filedesc.h>
55 #include <sys/event.h>
57 #include <sys/socket.h>
58 #include <sys/vnode.h>
60 #include <sys/thread2.h>
64 #include <net/bpfdesc.h>
65 #include <net/netmsg2.h>
66 #include <net/netisr2.h>
68 #include <netinet/in.h>
69 #include <netinet/if_ether.h>
70 #include <sys/kernel.h>
71 #include <sys/sysctl.h>
73 #include <netproto/802_11/ieee80211_dragonfly.h>
75 #include <sys/devfs.h>
77 struct netmsg_bpf_output {
78 struct netmsg_base base;
81 struct sockaddr *nm_dst;
84 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
85 DEVFS_DEFINE_CLONE_BITMAP(bpf);
88 #define BPF_PREALLOCATED_UNITS 4
90 #define BPF_PREALLOCATED_UNITS NBPF
96 * The default read buffer size is patchable.
98 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
99 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
100 &bpf_bufsize, 0, "Current size of bpf buffer");
101 int bpf_maxbufsize = BPF_MAXBUFSIZE;
102 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
103 &bpf_maxbufsize, 0, "Maximum size of bpf buffer");
106 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
108 static struct bpf_if *bpf_iflist;
110 static struct lwkt_token bpf_token = LWKT_TOKEN_INITIALIZER(bpf_token);
112 static int bpf_allocbufs(struct bpf_d *);
113 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
114 static void bpf_detachd(struct bpf_d *d);
115 static void bpf_resetd(struct bpf_d *);
116 static void bpf_freed(struct bpf_d *);
117 static void bpf_mcopy(volatile const void *, volatile void *, size_t);
118 static int bpf_movein(struct uio *, int, struct mbuf **,
119 struct sockaddr *, int *, struct bpf_insn *);
120 static int bpf_setif(struct bpf_d *, struct ifreq *);
121 static void bpf_timed_out(void *);
122 static void bpf_wakeup(struct bpf_d *);
123 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
124 void (*)(volatile const void *,
125 volatile void *, size_t),
126 const struct timeval *);
127 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
128 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
129 static int bpf_setdlt(struct bpf_d *, u_int);
130 static void bpf_drvinit(void *unused);
131 static void bpf_filter_detach(struct knote *kn);
132 static int bpf_filter_read(struct knote *kn, long hint);
134 static d_open_t bpfopen;
135 static d_clone_t bpfclone;
136 static d_close_t bpfclose;
137 static d_read_t bpfread;
138 static d_write_t bpfwrite;
139 static d_ioctl_t bpfioctl;
140 static d_kqfilter_t bpfkqfilter;
142 #define CDEV_MAJOR 23
143 static struct dev_ops bpf_ops = {
144 { "bpf", 0, D_MPSAFE },
150 .d_kqfilter = bpfkqfilter
155 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
156 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
158 const struct ieee80211_bpf_params *p;
169 * Build a sockaddr based on the data link layer type.
170 * We do this at this level because the ethernet header
171 * is copied directly into the data field of the sockaddr.
172 * In the case of SLIP, there is no header and the packet
173 * is forwarded as is.
174 * Also, we are careful to leave room at the front of the mbuf
175 * for the link level header.
179 sockp->sa_family = AF_INET;
184 sockp->sa_family = AF_UNSPEC;
185 /* XXX Would MAXLINKHDR be better? */
186 hlen = sizeof(struct ether_header);
191 sockp->sa_family = AF_UNSPEC;
195 case DLT_ATM_RFC1483:
197 * en atm driver requires 4-byte atm pseudo header.
198 * though it isn't standard, vpi:vci needs to be
201 sockp->sa_family = AF_UNSPEC;
202 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
206 sockp->sa_family = AF_UNSPEC;
207 hlen = 4; /* This should match PPP_HDRLEN */
210 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
211 sockp->sa_family = AF_IEEE80211;
215 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
216 sockp->sa_family = AF_IEEE80211;
217 sockp->sa_len = 12; /* XXX != 0 */
218 hlen = sizeof(struct ieee80211_bpf_params);
225 len = uio->uio_resid;
226 *datlen = len - hlen;
227 if ((unsigned)len > MCLBYTES)
230 m = m_getl(len, M_WAITOK, MT_DATA, M_PKTHDR, NULL);
233 m->m_pkthdr.len = m->m_len = len;
234 m->m_pkthdr.rcvif = NULL;
237 if (m->m_len < hlen) {
242 error = uiomove(mtod(m, u_char *), len, uio);
246 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
253 * Make room for link header, and copy it to sockaddr.
256 if (sockp->sa_family == AF_IEEE80211) {
258 * Collect true length from the parameter header
259 * NB: sockp is known to be zero'd so if we do a
260 * short copy unspecified parameters will be
262 * NB: packet may not be aligned after stripping
266 p = mtod(m, const struct ieee80211_bpf_params *);
268 if (hlen > sizeof(sockp->sa_data)) {
273 bcopy(m->m_data, sockp->sa_data, hlen);
274 m->m_pkthdr.len -= hlen;
276 m->m_data += hlen; /* XXX */
285 * Attach file to the bpf interface, i.e. make d listen on bp.
286 * Must be called at splimp.
289 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
292 * Point d at bp, and add d to the interface's list of listeners.
293 * Finally, point the driver's bpf cookie at the interface so
294 * it will divert packets to bpf.
296 lwkt_gettoken(&bpf_token);
298 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
299 *bp->bif_driverp = bp;
301 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
302 lwkt_reltoken(&bpf_token);
306 * Detach a file from its interface.
309 bpf_detachd(struct bpf_d *d)
315 lwkt_gettoken(&bpf_token);
319 /* Remove d from the interface's descriptor list. */
320 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
322 if (SLIST_EMPTY(&bp->bif_dlist)) {
324 * Let the driver know that there are no more listeners.
326 *bp->bif_driverp = NULL;
330 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
333 * Check if this descriptor had requested promiscuous mode.
334 * If so, turn it off.
338 error = ifpromisc(ifp, 0);
339 if (error != 0 && error != ENXIO) {
341 * ENXIO can happen if a pccard is unplugged,
342 * Something is really wrong if we were able to put
343 * the driver into promiscuous mode, but can't
346 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
350 lwkt_reltoken(&bpf_token);
354 * Open ethernet device. Returns ENXIO for illegal minor device number,
355 * EBUSY if file is open by another process.
359 bpfopen(struct dev_open_args *ap)
361 cdev_t dev = ap->a_head.a_dev;
364 lwkt_gettoken(&bpf_token);
365 if (ap->a_cred->cr_prison) {
366 lwkt_reltoken(&bpf_token);
372 * Each minor can be opened by only one process. If the requested
373 * minor is in use, return EBUSY.
376 lwkt_reltoken(&bpf_token);
380 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
382 d->bd_bufsize = bpf_bufsize;
385 callout_init(&d->bd_callout);
386 lwkt_reltoken(&bpf_token);
392 bpfclone(struct dev_clone_args *ap)
396 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
397 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
403 * Close the descriptor by detaching it from its interface,
404 * deallocating its buffers, and marking it free.
408 bpfclose(struct dev_close_args *ap)
410 cdev_t dev = ap->a_head.a_dev;
411 struct bpf_d *d = dev->si_drv1;
413 lwkt_gettoken(&bpf_token);
414 funsetown(&d->bd_sigio);
415 if (d->bd_state == BPF_WAITING)
416 callout_stop(&d->bd_callout);
417 d->bd_state = BPF_IDLE;
418 if (d->bd_bif != NULL)
422 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) {
423 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor);
427 lwkt_reltoken(&bpf_token);
433 * Rotate the packet buffers in descriptor d. Move the store buffer
434 * into the hold slot, and the free buffer into the store slot.
435 * Zero the length of the new store buffer.
437 #define ROTATE_BUFFERS(d) \
438 (d)->bd_hbuf = (d)->bd_sbuf; \
439 (d)->bd_hlen = (d)->bd_slen; \
440 (d)->bd_sbuf = (d)->bd_fbuf; \
444 * bpfread - read next chunk of packets from buffers
447 bpfread(struct dev_read_args *ap)
449 cdev_t dev = ap->a_head.a_dev;
450 struct bpf_d *d = dev->si_drv1;
454 lwkt_gettoken(&bpf_token);
456 * Restrict application to use a buffer the same size as
459 if (ap->a_uio->uio_resid != d->bd_bufsize) {
460 lwkt_reltoken(&bpf_token);
464 if (d->bd_state == BPF_WAITING)
465 callout_stop(&d->bd_callout);
466 timed_out = (d->bd_state == BPF_TIMED_OUT);
467 d->bd_state = BPF_IDLE;
469 * If the hold buffer is empty, then do a timed sleep, which
470 * ends when the timeout expires or when enough packets
471 * have arrived to fill the store buffer.
473 while (d->bd_hbuf == NULL) {
474 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
475 && d->bd_slen != 0) {
477 * A packet(s) either arrived since the previous,
478 * We're in immediate mode, or are reading
479 * in non-blocking mode, and a packet(s)
480 * either arrived since the previous
481 * read or arrived while we were asleep.
482 * Rotate the buffers and return what's here.
489 * No data is available, check to see if the bpf device
490 * is still pointed at a real interface. If not, return
491 * ENXIO so that the userland process knows to rebind
492 * it before using it again.
494 if (d->bd_bif == NULL) {
495 lwkt_reltoken(&bpf_token);
499 if (ap->a_ioflag & IO_NDELAY) {
500 lwkt_reltoken(&bpf_token);
503 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
504 if (error == EINTR || error == ERESTART) {
505 lwkt_reltoken(&bpf_token);
508 if (error == EWOULDBLOCK) {
510 * On a timeout, return what's in the buffer,
511 * which may be nothing. If there is something
512 * in the store buffer, we can rotate the buffers.
516 * We filled up the buffer in between
517 * getting the timeout and arriving
518 * here, so we don't need to rotate.
522 if (d->bd_slen == 0) {
523 lwkt_reltoken(&bpf_token);
531 * 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, ap->a_uio);
541 d->bd_fbuf = d->bd_hbuf;
544 lwkt_reltoken(&bpf_token);
551 * If there are processes sleeping on this descriptor, wake them up.
554 bpf_wakeup(struct bpf_d *d)
556 if (d->bd_state == BPF_WAITING) {
557 callout_stop(&d->bd_callout);
558 d->bd_state = BPF_IDLE;
561 if (d->bd_async && d->bd_sig && d->bd_sigio)
562 pgsigio(d->bd_sigio, d->bd_sig, 0);
564 KNOTE(&d->bd_kq.ki_note, 0);
568 bpf_timed_out(void *arg)
570 struct bpf_d *d = (struct bpf_d *)arg;
572 if (d->bd_state == BPF_WAITING) {
573 d->bd_state = BPF_TIMED_OUT;
580 bpf_output_dispatch(netmsg_t msg)
582 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
583 struct ifnet *ifp = bmsg->nm_ifp;
587 * The driver frees the mbuf.
589 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
590 lwkt_replymsg(&msg->lmsg, error);
594 bpfwrite(struct dev_write_args *ap)
596 cdev_t dev = ap->a_head.a_dev;
597 struct bpf_d *d = dev->si_drv1;
603 struct netmsg_bpf_output bmsg;
605 lwkt_gettoken(&bpf_token);
606 if (d->bd_bif == NULL) {
607 lwkt_reltoken(&bpf_token);
611 ifp = d->bd_bif->bif_ifp;
613 if (ap->a_uio->uio_resid == 0) {
614 lwkt_reltoken(&bpf_token);
618 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
619 &dst, &datlen, d->bd_wfilter);
621 lwkt_reltoken(&bpf_token);
625 if (datlen > ifp->if_mtu) {
627 lwkt_reltoken(&bpf_token);
632 dst.sa_family = pseudo_AF_HDRCMPLT;
634 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
635 0, bpf_output_dispatch);
640 ret = lwkt_domsg(netisr_cpuport(0), &bmsg.base.lmsg, 0);
641 lwkt_reltoken(&bpf_token);
647 * Reset a descriptor by flushing its packet buffer and clearing the
648 * receive and drop counts. Should be called at splimp.
651 bpf_resetd(struct bpf_d *d)
654 /* Free the hold buffer. */
655 d->bd_fbuf = d->bd_hbuf;
665 * FIONREAD Check for read packet available.
666 * SIOCGIFADDR Get interface address - convenient hook to driver.
667 * BIOCGBLEN Get buffer len [for read()].
668 * BIOCSETF Set ethernet read filter.
669 * BIOCSETWF Set ethernet write filter.
670 * BIOCFLUSH Flush read packet buffer.
671 * BIOCPROMISC Put interface into promiscuous mode.
672 * BIOCGDLT Get link layer type.
673 * BIOCGETIF Get interface name.
674 * BIOCSETIF Set interface.
675 * BIOCSRTIMEOUT Set read timeout.
676 * BIOCGRTIMEOUT Get read timeout.
677 * BIOCGSTATS Get packet stats.
678 * BIOCIMMEDIATE Set immediate mode.
679 * BIOCVERSION Get filter language version.
680 * BIOCGHDRCMPLT Get "header already complete" flag
681 * BIOCSHDRCMPLT Set "header already complete" flag
682 * BIOCGSEESENT Get "see packets sent" flag
683 * BIOCSSEESENT Set "see packets sent" flag
684 * BIOCLOCK Set "locked" flag
688 bpfioctl(struct dev_ioctl_args *ap)
690 cdev_t dev = ap->a_head.a_dev;
691 struct bpf_d *d = dev->si_drv1;
694 lwkt_gettoken(&bpf_token);
695 if (d->bd_state == BPF_WAITING)
696 callout_stop(&d->bd_callout);
697 d->bd_state = BPF_IDLE;
699 if (d->bd_locked == 1) {
718 lwkt_reltoken(&bpf_token);
728 * Check for read packet available.
738 *(int *)ap->a_data = n;
746 if (d->bd_bif == NULL) {
749 ifp = d->bd_bif->bif_ifp;
750 ifnet_serialize_all(ifp);
751 error = ifp->if_ioctl(ifp, ap->a_cmd,
752 ap->a_data, ap->a_cred);
753 ifnet_deserialize_all(ifp);
759 * Get buffer len [for read()].
762 *(u_int *)ap->a_data = d->bd_bufsize;
769 if (d->bd_bif != NULL) {
772 u_int size = *(u_int *)ap->a_data;
774 if (size > bpf_maxbufsize)
775 *(u_int *)ap->a_data = size = bpf_maxbufsize;
776 else if (size < BPF_MINBUFSIZE)
777 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
778 d->bd_bufsize = size;
783 * Set link layer read filter.
787 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
792 * Flush read packet buffer.
799 * Put interface into promiscuous mode.
802 if (d->bd_bif == NULL) {
804 * No interface attached yet.
809 if (d->bd_promisc == 0) {
810 error = ifpromisc(d->bd_bif->bif_ifp, 1);
817 * Get device parameters.
820 if (d->bd_bif == NULL)
823 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
827 * Get a list of supported data link types.
830 if (d->bd_bif == NULL) {
833 error = bpf_getdltlist(d,
834 (struct bpf_dltlist *)ap->a_data);
839 * Set data link type.
842 if (d->bd_bif == NULL)
845 error = bpf_setdlt(d, *(u_int *)ap->a_data);
849 * Get interface name.
852 if (d->bd_bif == NULL) {
855 struct ifnet *const ifp = d->bd_bif->bif_ifp;
856 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
858 strlcpy(ifr->ifr_name, ifp->if_xname,
859 sizeof ifr->ifr_name);
867 error = bpf_setif(d, (struct ifreq *)ap->a_data);
875 struct timeval *tv = (struct timeval *)ap->a_data;
878 * Subtract 1 tick from tvtohz() since this isn't
881 if ((error = itimerfix(tv)) == 0)
882 d->bd_rtout = tvtohz_low(tv);
891 struct timeval *tv = (struct timeval *)ap->a_data;
893 tv->tv_sec = d->bd_rtout / hz;
894 tv->tv_usec = (d->bd_rtout % hz) * ustick;
903 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
905 bs->bs_recv = d->bd_rcount;
906 bs->bs_drop = d->bd_dcount;
911 * Set immediate mode.
914 d->bd_immediate = *(u_int *)ap->a_data;
919 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
921 bv->bv_major = BPF_MAJOR_VERSION;
922 bv->bv_minor = BPF_MINOR_VERSION;
927 * Get "header already complete" flag
930 *(u_int *)ap->a_data = d->bd_hdrcmplt;
934 * Set "header already complete" flag
937 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
941 * Get "see sent packets" flag
944 *(u_int *)ap->a_data = d->bd_seesent;
948 * Set "see sent packets" flag
951 d->bd_seesent = *(u_int *)ap->a_data;
954 case FIOASYNC: /* Send signal on receive packets */
955 d->bd_async = *(int *)ap->a_data;
959 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
963 *(int *)ap->a_data = fgetown(&d->bd_sigio);
966 /* This is deprecated, FIOSETOWN should be used instead. */
968 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
971 /* This is deprecated, FIOGETOWN should be used instead. */
973 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
976 case BIOCSRSIG: /* Set receive signal */
980 sig = *(u_int *)ap->a_data;
989 *(u_int *)ap->a_data = d->bd_sig;
995 lwkt_reltoken(&bpf_token);
1001 * Set d's packet filter program to fp. If this file already has a filter,
1002 * free it and replace it. Returns EINVAL for bogus requests.
1005 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1007 struct bpf_insn *fcode, *old;
1008 u_int wfilter, flen, size;
1010 if (cmd == BIOCSETWF) {
1011 old = d->bd_wfilter;
1015 old = d->bd_rfilter;
1017 if (fp->bf_insns == NULL) {
1018 if (fp->bf_len != 0)
1021 d->bd_wfilter = NULL;
1023 d->bd_rfilter = NULL;
1030 if (flen > BPF_MAXINSNS)
1033 size = flen * sizeof *fp->bf_insns;
1034 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
1035 if (copyin(fp->bf_insns, fcode, size) == 0 &&
1036 bpf_validate(fcode, (int)flen)) {
1038 d->bd_wfilter = fcode;
1040 d->bd_rfilter = fcode;
1047 kfree(fcode, M_BPF);
1052 * Detach a file from its current interface (if attached at all) and attach
1053 * to the interface indicated by the name stored in ifr.
1054 * Return an errno or 0.
1057 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1061 struct ifnet *theywant;
1065 theywant = ifunit(ifr->ifr_name);
1066 if (theywant == NULL) {
1072 * Look through attached interfaces for the named one.
1074 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1075 struct ifnet *ifp = bp->bif_ifp;
1077 if (ifp == NULL || ifp != theywant)
1079 /* skip additional entry */
1080 if (bp->bif_driverp != &ifp->if_bpf)
1083 * We found the requested interface.
1084 * Allocate the packet buffers if we need to.
1085 * If we're already attached to requested interface,
1086 * just flush the buffer.
1088 if (d->bd_sbuf == NULL) {
1089 error = bpf_allocbufs(d);
1095 if (bp != d->bd_bif) {
1096 if (d->bd_bif != NULL) {
1098 * Detach if attached to something else.
1117 static struct filterops bpf_read_filtops =
1118 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1121 bpfkqfilter(struct dev_kqfilter_args *ap)
1123 cdev_t dev = ap->a_head.a_dev;
1124 struct knote *kn = ap->a_kn;
1125 struct klist *klist;
1128 lwkt_gettoken(&bpf_token);
1130 if (d->bd_bif == NULL) {
1132 lwkt_reltoken(&bpf_token);
1137 switch (kn->kn_filter) {
1139 kn->kn_fop = &bpf_read_filtops;
1140 kn->kn_hook = (caddr_t)d;
1143 ap->a_result = EOPNOTSUPP;
1144 lwkt_reltoken(&bpf_token);
1148 klist = &d->bd_kq.ki_note;
1149 knote_insert(klist, kn);
1150 lwkt_reltoken(&bpf_token);
1156 bpf_filter_detach(struct knote *kn)
1158 struct klist *klist;
1161 d = (struct bpf_d *)kn->kn_hook;
1162 klist = &d->bd_kq.ki_note;
1163 knote_remove(klist, kn);
1167 bpf_filter_read(struct knote *kn, long hint)
1172 d = (struct bpf_d *)kn->kn_hook;
1173 if (d->bd_hlen != 0 ||
1174 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1178 /* Start the read timeout if necessary. */
1179 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1180 callout_reset(&d->bd_callout, d->bd_rtout,
1182 d->bd_state = BPF_WAITING;
1191 * Process the packet pkt of length pktlen. The packet is parsed
1192 * by each listener's filter, and if accepted, stashed into the
1193 * corresponding buffer.
1196 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1203 lwkt_gettoken(&bpf_token);
1206 lwkt_reltoken(&bpf_token);
1211 * Note that the ipl does not have to be raised at this point.
1212 * The only problem that could arise here is that if two different
1213 * interfaces shared any data. This is not the case.
1215 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1217 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1223 catchpacket(d, pkt, pktlen, slen, bcopy, &tv);
1226 lwkt_reltoken(&bpf_token);
1230 * Copy data from an mbuf chain into a buffer. This code is derived
1231 * from m_copydata in sys/uipc_mbuf.c.
1234 bpf_mcopy(volatile const void *src_arg, volatile void *dst_arg, size_t len)
1236 volatile const struct mbuf *m;
1238 volatile u_char *dst;
1245 count = min(m->m_len, len);
1246 bcopy(mtod(m, void *), dst, count);
1254 * Process the packet in the mbuf chain m. The packet is parsed by each
1255 * listener's filter, and if accepted, stashed into the corresponding
1259 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1266 lwkt_gettoken(&bpf_token);
1269 lwkt_reltoken(&bpf_token);
1273 /* Don't compute pktlen, if no descriptor is attached. */
1274 if (SLIST_EMPTY(&bp->bif_dlist)) {
1275 lwkt_reltoken(&bpf_token);
1279 pktlen = m_lengthm(m, NULL);
1281 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1282 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1285 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1291 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1295 lwkt_reltoken(&bpf_token);
1299 * Incoming linkage from device drivers, where we have a mbuf chain
1300 * but need to prepend some arbitrary header from a linear buffer.
1302 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1303 * struct m_hdr on the stack. This is safe as bpf only reads from the
1304 * fields in this header that we initialize, and will not try to free
1305 * it or keep a pointer to it.
1308 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m,
1318 bpf_mtap(arg, (struct mbuf *) &mh);
1322 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1326 KKASSERT(family != AF_UNSPEC);
1328 family4 = (u_int)family;
1329 bpf_ptap(bp, m, &family4, sizeof(family4));
1333 * Process the packet in the mbuf chain m with the header in m prepended.
1334 * The packet is parsed by each listener's filter, and if accepted,
1335 * stashed into the corresponding buffer.
1338 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1343 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1344 * Note that we cut corners here; we only setup what's
1345 * absolutely needed--this mbuf should never go anywhere else.
1348 mb.m_data = __DECONST(void *, data); /* LINTED */
1350 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1356 * Move the packet data from interface memory (pkt) into the
1357 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1358 * otherwise 0. "copy" is the routine called to do the actual data
1359 * transfer. bcopy is passed in to copy contiguous chunks, while
1360 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1361 * pkt is really an mbuf.
1364 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1365 void (*cpfn)(volatile const void *, volatile void *, size_t),
1366 const struct timeval *tv)
1370 int hdrlen = d->bd_bif->bif_hdrlen;
1373 * Figure out how many bytes to move. If the packet is
1374 * greater or equal to the snapshot length, transfer that
1375 * much. Otherwise, transfer the whole packet (unless
1376 * we hit the buffer size limit).
1378 totlen = hdrlen + min(snaplen, pktlen);
1379 if (totlen > d->bd_bufsize)
1380 totlen = d->bd_bufsize;
1383 * Round up the end of the previous packet to the next longword.
1385 curlen = BPF_WORDALIGN(d->bd_slen);
1386 if (curlen + totlen > d->bd_bufsize) {
1388 * This packet will overflow the storage buffer.
1389 * Rotate the buffers if we can, then wakeup any
1392 if (d->bd_fbuf == NULL) {
1394 * We haven't completed the previous read yet,
1395 * so drop the packet.
1403 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1405 * Immediate mode is set, or the read timeout has
1406 * already expired during a select call. A packet
1407 * arrived, so the reader should be woken up.
1413 * Append the bpf header.
1415 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1416 hp->bh_tstamp = *tv;
1417 hp->bh_datalen = pktlen;
1418 hp->bh_hdrlen = hdrlen;
1420 * Copy the packet data into the store buffer and update its length.
1422 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1423 d->bd_slen = curlen + totlen;
1430 * Initialize all nonzero fields of a descriptor.
1433 bpf_allocbufs(struct bpf_d *d)
1435 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1436 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1443 * Free buffers and packet filter program currently in use by a descriptor.
1447 bpf_freed(struct bpf_d *d)
1450 * We don't need to lock out interrupts since this descriptor has
1451 * been detached from its interface and it yet hasn't been marked
1454 if (d->bd_sbuf != NULL) {
1455 kfree(d->bd_sbuf, M_BPF);
1456 if (d->bd_hbuf != NULL)
1457 kfree(d->bd_hbuf, M_BPF);
1458 if (d->bd_fbuf != NULL)
1459 kfree(d->bd_fbuf, M_BPF);
1462 kfree(d->bd_rfilter, M_BPF);
1464 kfree(d->bd_wfilter, M_BPF);
1468 * Attach an interface to bpf. ifp is a pointer to the structure
1469 * defining the interface to be attached, dlt is the link layer type,
1470 * and hdrlen is the fixed size of the link header (variable length
1471 * headers are not yet supported).
1474 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1476 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1480 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1484 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1486 lwkt_gettoken(&bpf_token);
1488 SLIST_INIT(&bp->bif_dlist);
1491 bp->bif_driverp = driverp;
1492 *bp->bif_driverp = NULL;
1494 bp->bif_next = bpf_iflist;
1498 * Compute the length of the bpf header. This is not necessarily
1499 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1500 * that the network layer header begins on a longword boundary (for
1501 * performance reasons and to alleviate alignment restrictions).
1503 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1505 lwkt_reltoken(&bpf_token);
1508 if_printf(ifp, "bpf attached\n");
1512 * Detach bpf from an interface. This involves detaching each descriptor
1513 * associated with the interface, and leaving bd_bif NULL. Notify each
1514 * descriptor as it's detached so that any sleepers wake up and get
1518 bpfdetach(struct ifnet *ifp)
1520 struct bpf_if *bp, *bp_prev;
1523 lwkt_gettoken(&bpf_token);
1525 /* Locate BPF interface information */
1527 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1528 if (ifp == bp->bif_ifp)
1533 /* Interface wasn't attached */
1534 if (bp->bif_ifp == NULL) {
1535 lwkt_reltoken(&bpf_token);
1536 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1540 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1545 if (bp_prev != NULL)
1546 bp_prev->bif_next = bp->bif_next;
1548 bpf_iflist = bp->bif_next;
1552 lwkt_reltoken(&bpf_token);
1556 * Get a list of available data link type of the interface.
1559 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1565 ifp = d->bd_bif->bif_ifp;
1568 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1569 if (bp->bif_ifp != ifp)
1571 if (bfl->bfl_list != NULL) {
1572 if (n >= bfl->bfl_len) {
1575 error = copyout(&bp->bif_dlt,
1576 bfl->bfl_list + n, sizeof(u_int));
1585 * Set the data link type of a BPF instance.
1588 bpf_setdlt(struct bpf_d *d, u_int dlt)
1590 int error, opromisc;
1594 if (d->bd_bif->bif_dlt == dlt)
1596 ifp = d->bd_bif->bif_ifp;
1597 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1598 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1602 opromisc = d->bd_promisc;
1607 error = ifpromisc(bp->bif_ifp, 1);
1609 if_printf(bp->bif_ifp,
1610 "bpf_setdlt: ifpromisc failed (%d)\n",
1617 return(bp == NULL ? EINVAL : 0);
1623 lwkt_gettoken(&bpf_token);
1629 lwkt_reltoken(&bpf_token);
1633 bpf_drvinit(void *unused)
1637 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1638 bpfclone, 0, 0, 0600, "bpf");
1639 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1640 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1641 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1646 bpf_drvuninit(void *unused)
1648 devfs_clone_handler_del("bpf");
1649 dev_ops_remove_all(&bpf_ops);
1650 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1653 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR, bpf_drvinit, NULL);
1654 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1658 * NOP stubs to allow bpf-using drivers to load and function.
1660 * A 'better' implementation would allow the core bpf functionality
1661 * to be loaded at runtime.
1665 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1670 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1675 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1680 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1685 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1690 bpfdetach(struct ifnet *ifp)
1695 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1697 return -1; /* "no filter" behaviour */