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;
82 boolean_t nm_feedback;
85 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
86 DEVFS_DEFINE_CLONE_BITMAP(bpf);
89 #define BPF_PREALLOCATED_UNITS 4
91 #define BPF_PREALLOCATED_UNITS NBPF
97 * The default read buffer size is patchable.
99 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
100 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
101 &bpf_bufsize, 0, "Current size of bpf buffer");
102 int bpf_maxbufsize = BPF_MAXBUFSIZE;
103 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
104 &bpf_maxbufsize, 0, "Maximum size of bpf buffer");
107 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
109 static struct bpf_if *bpf_iflist;
111 static struct lwkt_token bpf_token = LWKT_TOKEN_INITIALIZER(bpf_token);
113 static int bpf_allocbufs(struct bpf_d *);
114 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
115 static void bpf_detachd(struct bpf_d *d);
116 static void bpf_resetd(struct bpf_d *);
117 static void bpf_freed(struct bpf_d *);
118 static void bpf_mcopy(volatile const void *, volatile void *, size_t);
119 static int bpf_movein(struct uio *, int, struct mbuf **,
120 struct sockaddr *, int *, struct bpf_insn *);
121 static int bpf_setif(struct bpf_d *, struct ifreq *);
122 static void bpf_timed_out(void *);
123 static void bpf_wakeup(struct bpf_d *);
124 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
125 void (*)(volatile const void *,
126 volatile void *, size_t),
127 const struct timeval *);
128 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
129 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
130 static int bpf_setdlt(struct bpf_d *, u_int);
131 static void bpf_drvinit(void *unused);
132 static void bpf_filter_detach(struct knote *kn);
133 static int bpf_filter_read(struct knote *kn, long hint);
135 static d_open_t bpfopen;
136 static d_clone_t bpfclone;
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_kqfilter_t bpfkqfilter;
143 #define CDEV_MAJOR 23
144 static struct dev_ops bpf_ops = {
145 { "bpf", 0, D_MPSAFE },
151 .d_kqfilter = bpfkqfilter
156 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
157 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
159 const struct ieee80211_bpf_params *p;
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.
180 sockp->sa_family = AF_INET;
185 sockp->sa_family = AF_UNSPEC;
186 /* XXX Would MAXLINKHDR be better? */
187 hlen = sizeof(struct ether_header);
192 sockp->sa_family = AF_UNSPEC;
196 case DLT_ATM_RFC1483:
198 * en atm driver requires 4-byte atm pseudo header.
199 * though it isn't standard, vpi:vci needs to be
202 sockp->sa_family = AF_UNSPEC;
203 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
207 sockp->sa_family = AF_UNSPEC;
208 hlen = 4; /* This should match PPP_HDRLEN */
211 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
212 sockp->sa_family = AF_IEEE80211;
216 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
217 sockp->sa_family = AF_IEEE80211;
218 sockp->sa_len = 12; /* XXX != 0 */
219 hlen = sizeof(struct ieee80211_bpf_params);
226 len = uio->uio_resid;
227 *datlen = len - hlen;
228 if ((unsigned)len > MCLBYTES)
231 m = m_getl(len, M_WAITOK, MT_DATA, M_PKTHDR, NULL);
234 m->m_pkthdr.len = m->m_len = len;
235 m->m_pkthdr.rcvif = NULL;
238 if (m->m_len < hlen) {
243 error = uiomove(mtod(m, u_char *), len, uio);
247 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
254 * Make room for link header, and copy it to sockaddr.
257 if (sockp->sa_family == AF_IEEE80211) {
259 * Collect true length from the parameter header
260 * NB: sockp is known to be zero'd so if we do a
261 * short copy unspecified parameters will be
263 * NB: packet may not be aligned after stripping
267 p = mtod(m, const struct ieee80211_bpf_params *);
269 if (hlen > sizeof(sockp->sa_data)) {
274 bcopy(m->m_data, sockp->sa_data, hlen);
275 m->m_pkthdr.len -= hlen;
277 m->m_data += hlen; /* XXX */
286 * Attach file to the bpf interface, i.e. make d listen on bp.
287 * Must be called at splimp.
290 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
293 * Point d at bp, and add d to the interface's list of listeners.
294 * Finally, point the driver's bpf cookie at the interface so
295 * it will divert packets to bpf.
297 lwkt_gettoken(&bpf_token);
299 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
300 *bp->bif_driverp = bp;
302 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
303 lwkt_reltoken(&bpf_token);
307 * Detach a file from its interface.
310 bpf_detachd(struct bpf_d *d)
316 lwkt_gettoken(&bpf_token);
320 /* Remove d from the interface's descriptor list. */
321 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
323 if (SLIST_EMPTY(&bp->bif_dlist)) {
325 * Let the driver know that there are no more listeners.
327 *bp->bif_driverp = NULL;
331 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
334 * Check if this descriptor had requested promiscuous mode.
335 * If so, turn it off.
339 error = ifpromisc(ifp, 0);
340 if (error != 0 && error != ENXIO) {
342 * ENXIO can happen if a pccard is unplugged,
343 * Something is really wrong if we were able to put
344 * the driver into promiscuous mode, but can't
347 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
351 lwkt_reltoken(&bpf_token);
355 * Open ethernet device. Returns ENXIO for illegal minor device number,
356 * EBUSY if file is open by another process.
360 bpfopen(struct dev_open_args *ap)
362 cdev_t dev = ap->a_head.a_dev;
365 lwkt_gettoken(&bpf_token);
366 if (ap->a_cred->cr_prison) {
367 lwkt_reltoken(&bpf_token);
373 * Each minor can be opened by only one process. If the requested
374 * minor is in use, return EBUSY.
377 lwkt_reltoken(&bpf_token);
381 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
383 d->bd_bufsize = bpf_bufsize;
387 callout_init(&d->bd_callout);
388 lwkt_reltoken(&bpf_token);
394 bpfclone(struct dev_clone_args *ap)
398 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
399 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
405 * Close the descriptor by detaching it from its interface,
406 * deallocating its buffers, and marking it free.
410 bpfclose(struct dev_close_args *ap)
412 cdev_t dev = ap->a_head.a_dev;
413 struct bpf_d *d = dev->si_drv1;
415 lwkt_gettoken(&bpf_token);
416 funsetown(&d->bd_sigio);
417 if (d->bd_state == BPF_WAITING)
418 callout_stop(&d->bd_callout);
419 d->bd_state = BPF_IDLE;
420 if (d->bd_bif != NULL)
424 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) {
425 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor);
429 lwkt_reltoken(&bpf_token);
435 * Rotate the packet buffers in descriptor d. Move the store buffer
436 * into the hold slot, and the free buffer into the store slot.
437 * Zero the length of the new store buffer.
439 #define ROTATE_BUFFERS(d) \
440 (d)->bd_hbuf = (d)->bd_sbuf; \
441 (d)->bd_hlen = (d)->bd_slen; \
442 (d)->bd_sbuf = (d)->bd_fbuf; \
446 * bpfread - read next chunk of packets from buffers
449 bpfread(struct dev_read_args *ap)
451 cdev_t dev = ap->a_head.a_dev;
452 struct bpf_d *d = dev->si_drv1;
456 lwkt_gettoken(&bpf_token);
458 * Restrict application to use a buffer the same size as
461 if (ap->a_uio->uio_resid != d->bd_bufsize) {
462 lwkt_reltoken(&bpf_token);
466 if (d->bd_state == BPF_WAITING)
467 callout_stop(&d->bd_callout);
468 timed_out = (d->bd_state == BPF_TIMED_OUT);
469 d->bd_state = BPF_IDLE;
471 * If the hold buffer is empty, then do a timed sleep, which
472 * ends when the timeout expires or when enough packets
473 * have arrived to fill the store buffer.
475 while (d->bd_hbuf == NULL) {
476 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
477 && d->bd_slen != 0) {
479 * A packet(s) either arrived since the previous,
480 * We're in immediate mode, or are reading
481 * in non-blocking mode, and a packet(s)
482 * either arrived since the previous
483 * read or arrived while we were asleep.
484 * Rotate the buffers and return what's here.
491 * No data is available, check to see if the bpf device
492 * is still pointed at a real interface. If not, return
493 * ENXIO so that the userland process knows to rebind
494 * it before using it again.
496 if (d->bd_bif == NULL) {
497 lwkt_reltoken(&bpf_token);
501 if (ap->a_ioflag & IO_NDELAY) {
502 lwkt_reltoken(&bpf_token);
505 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
506 if (error == EINTR || error == ERESTART) {
507 lwkt_reltoken(&bpf_token);
510 if (error == EWOULDBLOCK) {
512 * On a timeout, return what's in the buffer,
513 * which may be nothing. If there is something
514 * in the store buffer, we can rotate the buffers.
518 * We filled up the buffer in between
519 * getting the timeout and arriving
520 * here, so we don't need to rotate.
524 if (d->bd_slen == 0) {
525 lwkt_reltoken(&bpf_token);
533 * At this point, we know we have something in the hold slot.
537 * Move data from hold buffer into user space.
538 * We know the entire buffer is transferred since
539 * we checked above that the read buffer is bpf_bufsize bytes.
541 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
543 d->bd_fbuf = d->bd_hbuf;
546 lwkt_reltoken(&bpf_token);
553 * If there are processes sleeping on this descriptor, wake them up.
556 bpf_wakeup(struct bpf_d *d)
558 if (d->bd_state == BPF_WAITING) {
559 callout_stop(&d->bd_callout);
560 d->bd_state = BPF_IDLE;
563 if (d->bd_async && d->bd_sig && d->bd_sigio)
564 pgsigio(d->bd_sigio, d->bd_sig, 0);
566 KNOTE(&d->bd_kq.ki_note, 0);
570 bpf_timed_out(void *arg)
572 struct bpf_d *d = (struct bpf_d *)arg;
574 if (d->bd_state == BPF_WAITING) {
575 d->bd_state = BPF_TIMED_OUT;
582 bpf_output_dispatch(netmsg_t msg)
584 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
585 struct ifnet *ifp = bmsg->nm_ifp;
586 struct mbuf *mc = NULL;
589 if (bmsg->nm_feedback) {
590 mc = m_dup(bmsg->nm_mbuf, M_NOWAIT);
592 mc->m_pkthdr.rcvif = ifp;
596 * The driver frees the mbuf.
598 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
599 lwkt_replymsg(&msg->lmsg, error);
603 mc->m_flags &= ~M_HASH;
604 (*ifp->if_input)(ifp, mc, NULL, -1);
612 bpfwrite(struct dev_write_args *ap)
614 cdev_t dev = ap->a_head.a_dev;
615 struct bpf_d *d = dev->si_drv1;
621 struct netmsg_bpf_output bmsg;
623 lwkt_gettoken(&bpf_token);
624 if (d->bd_bif == NULL) {
625 lwkt_reltoken(&bpf_token);
629 ifp = d->bd_bif->bif_ifp;
631 if (ap->a_uio->uio_resid == 0) {
632 lwkt_reltoken(&bpf_token);
636 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
637 &dst, &datlen, d->bd_wfilter);
639 lwkt_reltoken(&bpf_token);
643 if (datlen > ifp->if_mtu) {
645 lwkt_reltoken(&bpf_token);
650 dst.sa_family = pseudo_AF_HDRCMPLT;
652 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
653 0, bpf_output_dispatch);
659 bmsg.nm_feedback = TRUE;
661 bmsg.nm_feedback = FALSE;
663 ret = lwkt_domsg(netisr_cpuport(0), &bmsg.base.lmsg, 0);
665 lwkt_reltoken(&bpf_token);
671 * Reset a descriptor by flushing its packet buffer and clearing the
672 * receive and drop counts. Should be called at splimp.
675 bpf_resetd(struct bpf_d *d)
678 /* Free the hold buffer. */
679 d->bd_fbuf = d->bd_hbuf;
689 * FIONREAD Check for read packet available.
690 * SIOCGIFADDR Get interface address - convenient hook to driver.
691 * BIOCGBLEN Get buffer len [for read()].
692 * BIOCSETF Set ethernet read filter.
693 * BIOCSETWF Set ethernet write filter.
694 * BIOCFLUSH Flush read packet buffer.
695 * BIOCPROMISC Put interface into promiscuous mode.
696 * BIOCGDLT Get link layer type.
697 * BIOCGETIF Get interface name.
698 * BIOCSETIF Set interface.
699 * BIOCSRTIMEOUT Set read timeout.
700 * BIOCGRTIMEOUT Get read timeout.
701 * BIOCGSTATS Get packet stats.
702 * BIOCIMMEDIATE Set immediate mode.
703 * BIOCVERSION Get filter language version.
704 * BIOCGHDRCMPLT Get "header already complete" flag
705 * BIOCSHDRCMPLT Set "header already complete" flag
706 * BIOCSFEEDBACK Set packet feedback mode.
707 * BIOCGFEEDBACK Get packet feedback mode.
708 * BIOCGSEESENT Get "see packets sent" flag
709 * BIOCSSEESENT Set "see packets sent" flag
710 * BIOCLOCK Set "locked" flag
714 bpfioctl(struct dev_ioctl_args *ap)
716 cdev_t dev = ap->a_head.a_dev;
717 struct bpf_d *d = dev->si_drv1;
720 lwkt_gettoken(&bpf_token);
721 if (d->bd_state == BPF_WAITING)
722 callout_stop(&d->bd_callout);
723 d->bd_state = BPF_IDLE;
725 if (d->bd_locked == 1) {
744 lwkt_reltoken(&bpf_token);
754 * Check for read packet available.
764 *(int *)ap->a_data = n;
772 if (d->bd_bif == NULL) {
775 ifp = d->bd_bif->bif_ifp;
776 ifnet_serialize_all(ifp);
777 error = ifp->if_ioctl(ifp, ap->a_cmd,
778 ap->a_data, ap->a_cred);
779 ifnet_deserialize_all(ifp);
785 * Get buffer len [for read()].
788 *(u_int *)ap->a_data = d->bd_bufsize;
795 if (d->bd_bif != NULL) {
798 u_int size = *(u_int *)ap->a_data;
800 if (size > bpf_maxbufsize)
801 *(u_int *)ap->a_data = size = bpf_maxbufsize;
802 else if (size < BPF_MINBUFSIZE)
803 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
804 d->bd_bufsize = size;
809 * Set link layer read filter.
813 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
818 * Flush read packet buffer.
825 * Put interface into promiscuous mode.
828 if (d->bd_bif == NULL) {
830 * No interface attached yet.
835 if (d->bd_promisc == 0) {
836 error = ifpromisc(d->bd_bif->bif_ifp, 1);
843 * Get device parameters.
846 if (d->bd_bif == NULL)
849 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
853 * Get a list of supported data link types.
856 if (d->bd_bif == NULL) {
859 error = bpf_getdltlist(d,
860 (struct bpf_dltlist *)ap->a_data);
865 * Set data link type.
868 if (d->bd_bif == NULL)
871 error = bpf_setdlt(d, *(u_int *)ap->a_data);
875 * Get interface name.
878 if (d->bd_bif == NULL) {
881 struct ifnet *const ifp = d->bd_bif->bif_ifp;
882 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
884 strlcpy(ifr->ifr_name, ifp->if_xname,
885 sizeof ifr->ifr_name);
893 error = bpf_setif(d, (struct ifreq *)ap->a_data);
901 struct timeval *tv = (struct timeval *)ap->a_data;
904 * Subtract 1 tick from tvtohz() since this isn't
907 if ((error = itimerfix(tv)) == 0)
908 d->bd_rtout = tvtohz_low(tv);
917 struct timeval *tv = (struct timeval *)ap->a_data;
919 tv->tv_sec = d->bd_rtout / hz;
920 tv->tv_usec = (d->bd_rtout % hz) * ustick;
929 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
931 bs->bs_recv = d->bd_rcount;
932 bs->bs_drop = d->bd_dcount;
937 * Set immediate mode.
940 d->bd_immediate = *(u_int *)ap->a_data;
945 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
947 bv->bv_major = BPF_MAJOR_VERSION;
948 bv->bv_minor = BPF_MINOR_VERSION;
953 * Get "header already complete" flag
956 *(u_int *)ap->a_data = d->bd_hdrcmplt;
960 * Set "header already complete" flag
963 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
967 * Get "see sent packets" flag
970 *(u_int *)ap->a_data = d->bd_seesent;
974 * Set "see sent packets" flag
977 d->bd_seesent = *(u_int *)ap->a_data;
980 case FIOASYNC: /* Send signal on receive packets */
981 d->bd_async = *(int *)ap->a_data;
985 * Set "feed packets from bpf back to input" mode
988 d->bd_feedback = *(int *)ap->a_data;
992 * Get "feed packets from bpf back to input" mode
995 *(u_int *)ap->a_data = d->bd_feedback;
999 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
1003 *(int *)ap->a_data = fgetown(&d->bd_sigio);
1006 /* This is deprecated, FIOSETOWN should be used instead. */
1008 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
1011 /* This is deprecated, FIOGETOWN should be used instead. */
1013 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
1016 case BIOCSRSIG: /* Set receive signal */
1020 sig = *(u_int *)ap->a_data;
1029 *(u_int *)ap->a_data = d->bd_sig;
1035 lwkt_reltoken(&bpf_token);
1041 * Set d's packet filter program to fp. If this file already has a filter,
1042 * free it and replace it. Returns EINVAL for bogus requests.
1045 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1047 struct bpf_insn *fcode, *old;
1048 u_int wfilter, flen, size;
1050 if (cmd == BIOCSETWF) {
1051 old = d->bd_wfilter;
1055 old = d->bd_rfilter;
1057 if (fp->bf_insns == NULL) {
1058 if (fp->bf_len != 0)
1061 d->bd_wfilter = NULL;
1063 d->bd_rfilter = NULL;
1070 if (flen > BPF_MAXINSNS)
1073 size = flen * sizeof *fp->bf_insns;
1074 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
1075 if (copyin(fp->bf_insns, fcode, size) == 0 &&
1076 bpf_validate(fcode, (int)flen)) {
1078 d->bd_wfilter = fcode;
1080 d->bd_rfilter = fcode;
1087 kfree(fcode, M_BPF);
1092 * Detach a file from its current interface (if attached at all) and attach
1093 * to the interface indicated by the name stored in ifr.
1094 * Return an errno or 0.
1097 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1101 struct ifnet *theywant;
1105 theywant = ifunit(ifr->ifr_name);
1106 if (theywant == NULL) {
1112 * Look through attached interfaces for the named one.
1114 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1115 struct ifnet *ifp = bp->bif_ifp;
1117 if (ifp == NULL || ifp != theywant)
1119 /* skip additional entry */
1120 if (bp->bif_driverp != &ifp->if_bpf)
1123 * We found the requested interface.
1124 * Allocate the packet buffers if we need to.
1125 * If we're already attached to requested interface,
1126 * just flush the buffer.
1128 if (d->bd_sbuf == NULL) {
1129 error = bpf_allocbufs(d);
1135 if (bp != d->bd_bif) {
1136 if (d->bd_bif != NULL) {
1138 * Detach if attached to something else.
1157 static struct filterops bpf_read_filtops =
1158 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1161 bpfkqfilter(struct dev_kqfilter_args *ap)
1163 cdev_t dev = ap->a_head.a_dev;
1164 struct knote *kn = ap->a_kn;
1165 struct klist *klist;
1168 lwkt_gettoken(&bpf_token);
1170 if (d->bd_bif == NULL) {
1172 lwkt_reltoken(&bpf_token);
1177 switch (kn->kn_filter) {
1179 kn->kn_fop = &bpf_read_filtops;
1180 kn->kn_hook = (caddr_t)d;
1183 ap->a_result = EOPNOTSUPP;
1184 lwkt_reltoken(&bpf_token);
1188 klist = &d->bd_kq.ki_note;
1189 knote_insert(klist, kn);
1190 lwkt_reltoken(&bpf_token);
1196 bpf_filter_detach(struct knote *kn)
1198 struct klist *klist;
1201 d = (struct bpf_d *)kn->kn_hook;
1202 klist = &d->bd_kq.ki_note;
1203 knote_remove(klist, kn);
1207 bpf_filter_read(struct knote *kn, long hint)
1212 d = (struct bpf_d *)kn->kn_hook;
1213 if (d->bd_hlen != 0 ||
1214 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1218 /* Start the read timeout if necessary. */
1219 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1220 callout_reset(&d->bd_callout, d->bd_rtout,
1222 d->bd_state = BPF_WAITING;
1231 * Process the packet pkt of length pktlen. The packet is parsed
1232 * by each listener's filter, and if accepted, stashed into the
1233 * corresponding buffer.
1236 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1243 lwkt_gettoken(&bpf_token);
1246 lwkt_reltoken(&bpf_token);
1251 * Note that the ipl does not have to be raised at this point.
1252 * The only problem that could arise here is that if two different
1253 * interfaces shared any data. This is not the case.
1255 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1257 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1263 catchpacket(d, pkt, pktlen, slen, bcopy, &tv);
1266 lwkt_reltoken(&bpf_token);
1270 * Copy data from an mbuf chain into a buffer. This code is derived
1271 * from m_copydata in sys/uipc_mbuf.c.
1274 bpf_mcopy(volatile const void *src_arg, volatile void *dst_arg, size_t len)
1276 volatile const struct mbuf *m;
1278 volatile u_char *dst;
1285 count = min(m->m_len, len);
1286 bcopy(mtod(m, void *), dst, count);
1294 * Process the packet in the mbuf chain m. The packet is parsed by each
1295 * listener's filter, and if accepted, stashed into the corresponding
1299 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1306 lwkt_gettoken(&bpf_token);
1309 lwkt_reltoken(&bpf_token);
1313 /* Don't compute pktlen, if no descriptor is attached. */
1314 if (SLIST_EMPTY(&bp->bif_dlist)) {
1315 lwkt_reltoken(&bpf_token);
1319 pktlen = m_lengthm(m, NULL);
1321 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1322 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1325 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1331 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1335 lwkt_reltoken(&bpf_token);
1339 * Incoming linkage from device drivers, where we have a mbuf chain
1340 * but need to prepend some arbitrary header from a linear buffer.
1342 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1343 * struct m_hdr on the stack. This is safe as bpf only reads from the
1344 * fields in this header that we initialize, and will not try to free
1345 * it or keep a pointer to it.
1348 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m,
1358 bpf_mtap(arg, (struct mbuf *) &mh);
1362 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1366 KKASSERT(family != AF_UNSPEC);
1368 family4 = (u_int)family;
1369 bpf_ptap(bp, m, &family4, sizeof(family4));
1373 * Process the packet in the mbuf chain m with the header in m prepended.
1374 * The packet is parsed by each listener's filter, and if accepted,
1375 * stashed into the corresponding buffer.
1378 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1383 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1384 * Note that we cut corners here; we only setup what's
1385 * absolutely needed--this mbuf should never go anywhere else.
1388 mb.m_data = __DECONST(void *, data); /* LINTED */
1390 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1396 * Move the packet data from interface memory (pkt) into the
1397 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1398 * otherwise 0. "copy" is the routine called to do the actual data
1399 * transfer. bcopy is passed in to copy contiguous chunks, while
1400 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1401 * pkt is really an mbuf.
1404 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1405 void (*cpfn)(volatile const void *, volatile void *, size_t),
1406 const struct timeval *tv)
1410 int hdrlen = d->bd_bif->bif_hdrlen;
1413 * Figure out how many bytes to move. If the packet is
1414 * greater or equal to the snapshot length, transfer that
1415 * much. Otherwise, transfer the whole packet (unless
1416 * we hit the buffer size limit).
1418 totlen = hdrlen + min(snaplen, pktlen);
1419 if (totlen > d->bd_bufsize)
1420 totlen = d->bd_bufsize;
1423 * Round up the end of the previous packet to the next longword.
1425 curlen = BPF_WORDALIGN(d->bd_slen);
1426 if (curlen + totlen > d->bd_bufsize) {
1428 * This packet will overflow the storage buffer.
1429 * Rotate the buffers if we can, then wakeup any
1432 if (d->bd_fbuf == NULL) {
1434 * We haven't completed the previous read yet,
1435 * so drop the packet.
1443 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1445 * Immediate mode is set, or the read timeout has
1446 * already expired during a select call. A packet
1447 * arrived, so the reader should be woken up.
1453 * Append the bpf header.
1455 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1456 hp->bh_tstamp = *tv;
1457 hp->bh_datalen = pktlen;
1458 hp->bh_hdrlen = hdrlen;
1460 * Copy the packet data into the store buffer and update its length.
1462 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1463 d->bd_slen = curlen + totlen;
1470 * Initialize all nonzero fields of a descriptor.
1473 bpf_allocbufs(struct bpf_d *d)
1475 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1476 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1483 * Free buffers and packet filter program currently in use by a descriptor.
1487 bpf_freed(struct bpf_d *d)
1490 * We don't need to lock out interrupts since this descriptor has
1491 * been detached from its interface and it yet hasn't been marked
1494 if (d->bd_sbuf != NULL) {
1495 kfree(d->bd_sbuf, M_BPF);
1496 if (d->bd_hbuf != NULL)
1497 kfree(d->bd_hbuf, M_BPF);
1498 if (d->bd_fbuf != NULL)
1499 kfree(d->bd_fbuf, M_BPF);
1502 kfree(d->bd_rfilter, M_BPF);
1504 kfree(d->bd_wfilter, M_BPF);
1508 * Attach an interface to bpf. ifp is a pointer to the structure
1509 * defining the interface to be attached, dlt is the link layer type,
1510 * and hdrlen is the fixed size of the link header (variable length
1511 * headers are not yet supported).
1514 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1516 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1520 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1524 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1526 lwkt_gettoken(&bpf_token);
1528 SLIST_INIT(&bp->bif_dlist);
1531 bp->bif_driverp = driverp;
1532 *bp->bif_driverp = NULL;
1534 bp->bif_next = bpf_iflist;
1538 * Compute the length of the bpf header. This is not necessarily
1539 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1540 * that the network layer header begins on a longword boundary (for
1541 * performance reasons and to alleviate alignment restrictions).
1543 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1545 lwkt_reltoken(&bpf_token);
1548 if_printf(ifp, "bpf attached\n");
1552 * Detach bpf from an interface. This involves detaching each descriptor
1553 * associated with the interface, and leaving bd_bif NULL. Notify each
1554 * descriptor as it's detached so that any sleepers wake up and get
1558 bpfdetach(struct ifnet *ifp)
1560 struct bpf_if *bp, *bp_prev;
1563 lwkt_gettoken(&bpf_token);
1565 /* Locate BPF interface information */
1567 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1568 if (ifp == bp->bif_ifp)
1573 /* Interface wasn't attached */
1574 if (bp->bif_ifp == NULL) {
1575 lwkt_reltoken(&bpf_token);
1576 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1580 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1585 if (bp_prev != NULL)
1586 bp_prev->bif_next = bp->bif_next;
1588 bpf_iflist = bp->bif_next;
1592 lwkt_reltoken(&bpf_token);
1596 * Get a list of available data link type of the interface.
1599 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1605 ifp = d->bd_bif->bif_ifp;
1608 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1609 if (bp->bif_ifp != ifp)
1611 if (bfl->bfl_list != NULL) {
1612 if (n >= bfl->bfl_len) {
1615 error = copyout(&bp->bif_dlt,
1616 bfl->bfl_list + n, sizeof(u_int));
1625 * Set the data link type of a BPF instance.
1628 bpf_setdlt(struct bpf_d *d, u_int dlt)
1630 int error, opromisc;
1634 if (d->bd_bif->bif_dlt == dlt)
1636 ifp = d->bd_bif->bif_ifp;
1637 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1638 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1642 opromisc = d->bd_promisc;
1647 error = ifpromisc(bp->bif_ifp, 1);
1649 if_printf(bp->bif_ifp,
1650 "bpf_setdlt: ifpromisc failed (%d)\n",
1657 return(bp == NULL ? EINVAL : 0);
1663 lwkt_gettoken(&bpf_token);
1669 lwkt_reltoken(&bpf_token);
1673 bpf_drvinit(void *unused)
1677 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1678 bpfclone, 0, 0, 0600, "bpf");
1679 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1680 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1681 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1686 bpf_drvuninit(void *unused)
1688 devfs_clone_handler_del("bpf");
1689 dev_ops_remove_all(&bpf_ops);
1690 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1693 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR, bpf_drvinit, NULL);
1694 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1698 * NOP stubs to allow bpf-using drivers to load and function.
1700 * A 'better' implementation would allow the core bpf functionality
1701 * to be loaded at runtime.
1705 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1710 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1715 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1720 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1725 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1730 bpfdetach(struct ifnet *ifp)
1735 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1737 return -1; /* "no filter" behaviour */