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 <sys/devfs.h>
75 struct netmsg_bpf_output {
76 struct netmsg_base base;
79 struct sockaddr *nm_dst;
82 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
83 DEVFS_DECLARE_CLONE_BITMAP(bpf);
86 #define BPF_PREALLOCATED_UNITS 4
88 #define BPF_PREALLOCATED_UNITS NBPF
94 * The default read buffer size is patchable.
96 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
97 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
98 &bpf_bufsize, 0, "Current size of bpf buffer");
99 int bpf_maxbufsize = BPF_MAXBUFSIZE;
100 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
101 &bpf_maxbufsize, 0, "Maximum size of bpf buffer");
104 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
106 static struct bpf_if *bpf_iflist;
108 static struct lwkt_token bpf_token = LWKT_TOKEN_INITIALIZER(bpf_token);
110 static int bpf_allocbufs(struct bpf_d *);
111 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
112 static void bpf_detachd(struct bpf_d *d);
113 static void bpf_resetd(struct bpf_d *);
114 static void bpf_freed(struct bpf_d *);
115 static void bpf_mcopy(const void *, void *, size_t);
116 static int bpf_movein(struct uio *, int, struct mbuf **,
117 struct sockaddr *, int *, struct bpf_insn *);
118 static int bpf_setif(struct bpf_d *, struct ifreq *);
119 static void bpf_timed_out(void *);
120 static void bpf_wakeup(struct bpf_d *);
121 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
122 void (*)(const void *, void *, size_t),
123 const struct timeval *);
124 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
125 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
126 static int bpf_setdlt(struct bpf_d *, u_int);
127 static void bpf_drvinit(void *unused);
128 static void bpf_filter_detach(struct knote *kn);
129 static int bpf_filter_read(struct knote *kn, long hint);
131 static d_open_t bpfopen;
132 static d_clone_t bpfclone;
133 static d_close_t bpfclose;
134 static d_read_t bpfread;
135 static d_write_t bpfwrite;
136 static d_ioctl_t bpfioctl;
137 static d_kqfilter_t bpfkqfilter;
139 #define CDEV_MAJOR 23
140 static struct dev_ops bpf_ops = {
141 { "bpf", 0, D_MPSAFE },
147 .d_kqfilter = bpfkqfilter
152 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
153 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
165 * Build a sockaddr based on the data link layer type.
166 * We do this at this level because the ethernet header
167 * is copied directly into the data field of the sockaddr.
168 * In the case of SLIP, there is no header and the packet
169 * is forwarded as is.
170 * Also, we are careful to leave room at the front of the mbuf
171 * for the link level header.
175 sockp->sa_family = AF_INET;
180 sockp->sa_family = AF_UNSPEC;
181 /* XXX Would MAXLINKHDR be better? */
182 hlen = sizeof(struct ether_header);
187 sockp->sa_family = AF_UNSPEC;
191 case DLT_ATM_RFC1483:
193 * en atm driver requires 4-byte atm pseudo header.
194 * though it isn't standard, vpi:vci needs to be
197 sockp->sa_family = AF_UNSPEC;
198 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
202 sockp->sa_family = AF_UNSPEC;
203 hlen = 4; /* This should match PPP_HDRLEN */
210 len = uio->uio_resid;
211 *datlen = len - hlen;
212 if ((unsigned)len > MCLBYTES)
215 m = m_getl(len, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
218 m->m_pkthdr.len = m->m_len = len;
219 m->m_pkthdr.rcvif = NULL;
222 if (m->m_len < hlen) {
227 error = uiomove(mtod(m, u_char *), len, uio);
231 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
238 * Make room for link header, and copy it to sockaddr.
241 bcopy(m->m_data, sockp->sa_data, hlen);
242 m->m_pkthdr.len -= hlen;
244 m->m_data += hlen; /* XXX */
253 * Attach file to the bpf interface, i.e. make d listen on bp.
254 * Must be called at splimp.
257 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
260 * Point d at bp, and add d to the interface's list of listeners.
261 * Finally, point the driver's bpf cookie at the interface so
262 * it will divert packets to bpf.
264 lwkt_gettoken(&bpf_token);
266 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
267 *bp->bif_driverp = bp;
269 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
270 lwkt_reltoken(&bpf_token);
274 * Detach a file from its interface.
277 bpf_detachd(struct bpf_d *d)
283 lwkt_gettoken(&bpf_token);
287 /* Remove d from the interface's descriptor list. */
288 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
290 if (SLIST_EMPTY(&bp->bif_dlist)) {
292 * Let the driver know that there are no more listeners.
294 *bp->bif_driverp = NULL;
298 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
301 * Check if this descriptor had requested promiscuous mode.
302 * If so, turn it off.
306 error = ifpromisc(ifp, 0);
307 if (error != 0 && error != ENXIO) {
309 * ENXIO can happen if a pccard is unplugged,
310 * Something is really wrong if we were able to put
311 * the driver into promiscuous mode, but can't
314 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
318 lwkt_reltoken(&bpf_token);
322 * Open ethernet device. Returns ENXIO for illegal minor device number,
323 * EBUSY if file is open by another process.
327 bpfopen(struct dev_open_args *ap)
329 cdev_t dev = ap->a_head.a_dev;
332 lwkt_gettoken(&bpf_token);
333 if (ap->a_cred->cr_prison) {
334 lwkt_reltoken(&bpf_token);
340 * Each minor can be opened by only one process. If the requested
341 * minor is in use, return EBUSY.
344 lwkt_reltoken(&bpf_token);
348 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
350 d->bd_bufsize = bpf_bufsize;
353 callout_init(&d->bd_callout);
354 lwkt_reltoken(&bpf_token);
360 bpfclone(struct dev_clone_args *ap)
364 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
365 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
371 * Close the descriptor by detaching it from its interface,
372 * deallocating its buffers, and marking it free.
376 bpfclose(struct dev_close_args *ap)
378 cdev_t dev = ap->a_head.a_dev;
379 struct bpf_d *d = dev->si_drv1;
381 lwkt_gettoken(&bpf_token);
382 funsetown(&d->bd_sigio);
383 if (d->bd_state == BPF_WAITING)
384 callout_stop(&d->bd_callout);
385 d->bd_state = BPF_IDLE;
386 if (d->bd_bif != NULL)
390 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) {
391 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor);
395 lwkt_reltoken(&bpf_token);
401 * Rotate the packet buffers in descriptor d. Move the store buffer
402 * into the hold slot, and the free buffer into the store slot.
403 * Zero the length of the new store buffer.
405 #define ROTATE_BUFFERS(d) \
406 (d)->bd_hbuf = (d)->bd_sbuf; \
407 (d)->bd_hlen = (d)->bd_slen; \
408 (d)->bd_sbuf = (d)->bd_fbuf; \
412 * bpfread - read next chunk of packets from buffers
415 bpfread(struct dev_read_args *ap)
417 cdev_t dev = ap->a_head.a_dev;
418 struct bpf_d *d = dev->si_drv1;
422 lwkt_gettoken(&bpf_token);
424 * Restrict application to use a buffer the same size as
427 if (ap->a_uio->uio_resid != d->bd_bufsize) {
428 lwkt_reltoken(&bpf_token);
432 if (d->bd_state == BPF_WAITING)
433 callout_stop(&d->bd_callout);
434 timed_out = (d->bd_state == BPF_TIMED_OUT);
435 d->bd_state = BPF_IDLE;
437 * If the hold buffer is empty, then do a timed sleep, which
438 * ends when the timeout expires or when enough packets
439 * have arrived to fill the store buffer.
441 while (d->bd_hbuf == NULL) {
442 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
443 && d->bd_slen != 0) {
445 * A packet(s) either arrived since the previous,
446 * We're in immediate mode, or are reading
447 * in non-blocking mode, and a packet(s)
448 * either arrived since the previous
449 * read or arrived while we were asleep.
450 * Rotate the buffers and return what's here.
457 * No data is available, check to see if the bpf device
458 * is still pointed at a real interface. If not, return
459 * ENXIO so that the userland process knows to rebind
460 * it before using it again.
462 if (d->bd_bif == NULL) {
463 lwkt_reltoken(&bpf_token);
467 if (ap->a_ioflag & IO_NDELAY) {
468 lwkt_reltoken(&bpf_token);
471 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
472 if (error == EINTR || error == ERESTART) {
473 lwkt_reltoken(&bpf_token);
476 if (error == EWOULDBLOCK) {
478 * On a timeout, return what's in the buffer,
479 * which may be nothing. If there is something
480 * in the store buffer, we can rotate the buffers.
484 * We filled up the buffer in between
485 * getting the timeout and arriving
486 * here, so we don't need to rotate.
490 if (d->bd_slen == 0) {
491 lwkt_reltoken(&bpf_token);
499 * At this point, we know we have something in the hold slot.
503 * Move data from hold buffer into user space.
504 * We know the entire buffer is transferred since
505 * we checked above that the read buffer is bpf_bufsize bytes.
507 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
509 d->bd_fbuf = d->bd_hbuf;
512 lwkt_reltoken(&bpf_token);
519 * If there are processes sleeping on this descriptor, wake them up.
522 bpf_wakeup(struct bpf_d *d)
524 if (d->bd_state == BPF_WAITING) {
525 callout_stop(&d->bd_callout);
526 d->bd_state = BPF_IDLE;
529 if (d->bd_async && d->bd_sig && d->bd_sigio)
530 pgsigio(d->bd_sigio, d->bd_sig, 0);
532 KNOTE(&d->bd_kq.ki_note, 0);
536 bpf_timed_out(void *arg)
538 struct bpf_d *d = (struct bpf_d *)arg;
540 if (d->bd_state == BPF_WAITING) {
541 d->bd_state = BPF_TIMED_OUT;
548 bpf_output_dispatch(netmsg_t msg)
550 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
551 struct ifnet *ifp = bmsg->nm_ifp;
555 * The driver frees the mbuf.
557 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
558 lwkt_replymsg(&msg->lmsg, error);
562 bpfwrite(struct dev_write_args *ap)
564 cdev_t dev = ap->a_head.a_dev;
565 struct bpf_d *d = dev->si_drv1;
571 struct netmsg_bpf_output bmsg;
573 lwkt_gettoken(&bpf_token);
574 if (d->bd_bif == NULL) {
575 lwkt_reltoken(&bpf_token);
579 ifp = d->bd_bif->bif_ifp;
581 if (ap->a_uio->uio_resid == 0) {
582 lwkt_reltoken(&bpf_token);
586 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
587 &dst, &datlen, d->bd_wfilter);
589 lwkt_reltoken(&bpf_token);
593 if (datlen > ifp->if_mtu) {
595 lwkt_reltoken(&bpf_token);
600 dst.sa_family = pseudo_AF_HDRCMPLT;
602 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
603 0, bpf_output_dispatch);
608 ret = lwkt_domsg(netisr_cpuport(0), &bmsg.base.lmsg, 0);
609 lwkt_reltoken(&bpf_token);
615 * Reset a descriptor by flushing its packet buffer and clearing the
616 * receive and drop counts. Should be called at splimp.
619 bpf_resetd(struct bpf_d *d)
622 /* Free the hold buffer. */
623 d->bd_fbuf = d->bd_hbuf;
633 * FIONREAD Check for read packet available.
634 * SIOCGIFADDR Get interface address - convenient hook to driver.
635 * BIOCGBLEN Get buffer len [for read()].
636 * BIOCSETF Set ethernet read filter.
637 * BIOCSETWF Set ethernet write filter.
638 * BIOCFLUSH Flush read packet buffer.
639 * BIOCPROMISC Put interface into promiscuous mode.
640 * BIOCGDLT Get link layer type.
641 * BIOCGETIF Get interface name.
642 * BIOCSETIF Set interface.
643 * BIOCSRTIMEOUT Set read timeout.
644 * BIOCGRTIMEOUT Get read timeout.
645 * BIOCGSTATS Get packet stats.
646 * BIOCIMMEDIATE Set immediate mode.
647 * BIOCVERSION Get filter language version.
648 * BIOCGHDRCMPLT Get "header already complete" flag
649 * BIOCSHDRCMPLT Set "header already complete" flag
650 * BIOCGSEESENT Get "see packets sent" flag
651 * BIOCSSEESENT Set "see packets sent" flag
652 * BIOCLOCK Set "locked" flag
656 bpfioctl(struct dev_ioctl_args *ap)
658 cdev_t dev = ap->a_head.a_dev;
659 struct bpf_d *d = dev->si_drv1;
662 lwkt_gettoken(&bpf_token);
663 if (d->bd_state == BPF_WAITING)
664 callout_stop(&d->bd_callout);
665 d->bd_state = BPF_IDLE;
667 if (d->bd_locked == 1) {
686 lwkt_reltoken(&bpf_token);
696 * Check for read packet available.
706 *(int *)ap->a_data = n;
714 if (d->bd_bif == NULL) {
717 ifp = d->bd_bif->bif_ifp;
718 ifnet_serialize_all(ifp);
719 error = ifp->if_ioctl(ifp, ap->a_cmd,
720 ap->a_data, ap->a_cred);
721 ifnet_deserialize_all(ifp);
727 * Get buffer len [for read()].
730 *(u_int *)ap->a_data = d->bd_bufsize;
737 if (d->bd_bif != NULL) {
740 u_int size = *(u_int *)ap->a_data;
742 if (size > bpf_maxbufsize)
743 *(u_int *)ap->a_data = size = bpf_maxbufsize;
744 else if (size < BPF_MINBUFSIZE)
745 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
746 d->bd_bufsize = size;
751 * Set link layer read filter.
755 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
760 * Flush read packet buffer.
767 * Put interface into promiscuous mode.
770 if (d->bd_bif == NULL) {
772 * No interface attached yet.
777 if (d->bd_promisc == 0) {
778 error = ifpromisc(d->bd_bif->bif_ifp, 1);
785 * Get device parameters.
788 if (d->bd_bif == NULL)
791 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
795 * Get a list of supported data link types.
798 if (d->bd_bif == NULL) {
801 error = bpf_getdltlist(d,
802 (struct bpf_dltlist *)ap->a_data);
807 * Set data link type.
810 if (d->bd_bif == NULL)
813 error = bpf_setdlt(d, *(u_int *)ap->a_data);
817 * Get interface name.
820 if (d->bd_bif == NULL) {
823 struct ifnet *const ifp = d->bd_bif->bif_ifp;
824 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
826 strlcpy(ifr->ifr_name, ifp->if_xname,
827 sizeof ifr->ifr_name);
835 error = bpf_setif(d, (struct ifreq *)ap->a_data);
843 struct timeval *tv = (struct timeval *)ap->a_data;
846 * Subtract 1 tick from tvtohz() since this isn't
849 if ((error = itimerfix(tv)) == 0)
850 d->bd_rtout = tvtohz_low(tv);
859 struct timeval *tv = (struct timeval *)ap->a_data;
861 tv->tv_sec = d->bd_rtout / hz;
862 tv->tv_usec = (d->bd_rtout % hz) * ustick;
871 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
873 bs->bs_recv = d->bd_rcount;
874 bs->bs_drop = d->bd_dcount;
879 * Set immediate mode.
882 d->bd_immediate = *(u_int *)ap->a_data;
887 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
889 bv->bv_major = BPF_MAJOR_VERSION;
890 bv->bv_minor = BPF_MINOR_VERSION;
895 * Get "header already complete" flag
898 *(u_int *)ap->a_data = d->bd_hdrcmplt;
902 * Set "header already complete" flag
905 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
909 * Get "see sent packets" flag
912 *(u_int *)ap->a_data = d->bd_seesent;
916 * Set "see sent packets" flag
919 d->bd_seesent = *(u_int *)ap->a_data;
922 case FIOASYNC: /* Send signal on receive packets */
923 d->bd_async = *(int *)ap->a_data;
927 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
931 *(int *)ap->a_data = fgetown(&d->bd_sigio);
934 /* This is deprecated, FIOSETOWN should be used instead. */
936 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
939 /* This is deprecated, FIOGETOWN should be used instead. */
941 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
944 case BIOCSRSIG: /* Set receive signal */
948 sig = *(u_int *)ap->a_data;
957 *(u_int *)ap->a_data = d->bd_sig;
963 lwkt_reltoken(&bpf_token);
969 * Set d's packet filter program to fp. If this file already has a filter,
970 * free it and replace it. Returns EINVAL for bogus requests.
973 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
975 struct bpf_insn *fcode, *old;
976 u_int wfilter, flen, size;
978 if (cmd == BIOCSETWF) {
985 if (fp->bf_insns == NULL) {
989 d->bd_wfilter = NULL;
991 d->bd_rfilter = NULL;
998 if (flen > BPF_MAXINSNS)
1001 size = flen * sizeof *fp->bf_insns;
1002 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
1003 if (copyin(fp->bf_insns, fcode, size) == 0 &&
1004 bpf_validate(fcode, (int)flen)) {
1006 d->bd_wfilter = fcode;
1008 d->bd_rfilter = fcode;
1015 kfree(fcode, M_BPF);
1020 * Detach a file from its current interface (if attached at all) and attach
1021 * to the interface indicated by the name stored in ifr.
1022 * Return an errno or 0.
1025 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1029 struct ifnet *theywant;
1031 theywant = ifunit(ifr->ifr_name);
1032 if (theywant == NULL)
1036 * Look through attached interfaces for the named one.
1038 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1039 struct ifnet *ifp = bp->bif_ifp;
1041 if (ifp == NULL || ifp != theywant)
1043 /* skip additional entry */
1044 if (bp->bif_driverp != &ifp->if_bpf)
1047 * We found the requested interface.
1048 * Allocate the packet buffers if we need to.
1049 * If we're already attached to requested interface,
1050 * just flush the buffer.
1052 if (d->bd_sbuf == NULL) {
1053 error = bpf_allocbufs(d);
1057 if (bp != d->bd_bif) {
1058 if (d->bd_bif != NULL) {
1060 * Detach if attached to something else.
1075 static struct filterops bpf_read_filtops =
1076 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1079 bpfkqfilter(struct dev_kqfilter_args *ap)
1081 cdev_t dev = ap->a_head.a_dev;
1082 struct knote *kn = ap->a_kn;
1083 struct klist *klist;
1086 lwkt_gettoken(&bpf_token);
1088 if (d->bd_bif == NULL) {
1090 lwkt_reltoken(&bpf_token);
1095 switch (kn->kn_filter) {
1097 kn->kn_fop = &bpf_read_filtops;
1098 kn->kn_hook = (caddr_t)d;
1101 ap->a_result = EOPNOTSUPP;
1102 lwkt_reltoken(&bpf_token);
1106 klist = &d->bd_kq.ki_note;
1107 knote_insert(klist, kn);
1108 lwkt_reltoken(&bpf_token);
1114 bpf_filter_detach(struct knote *kn)
1116 struct klist *klist;
1119 d = (struct bpf_d *)kn->kn_hook;
1120 klist = &d->bd_kq.ki_note;
1121 knote_remove(klist, kn);
1125 bpf_filter_read(struct knote *kn, long hint)
1130 d = (struct bpf_d *)kn->kn_hook;
1131 if (d->bd_hlen != 0 ||
1132 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1136 /* Start the read timeout if necessary. */
1137 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1138 callout_reset(&d->bd_callout, d->bd_rtout,
1140 d->bd_state = BPF_WAITING;
1149 * Process the packet pkt of length pktlen. The packet is parsed
1150 * by each listener's filter, and if accepted, stashed into the
1151 * corresponding buffer.
1154 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1161 lwkt_gettoken(&bpf_token);
1164 lwkt_reltoken(&bpf_token);
1169 * Note that the ipl does not have to be raised at this point.
1170 * The only problem that could arise here is that if two different
1171 * interfaces shared any data. This is not the case.
1173 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1175 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1181 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv);
1184 lwkt_reltoken(&bpf_token);
1188 * Copy data from an mbuf chain into a buffer. This code is derived
1189 * from m_copydata in sys/uipc_mbuf.c.
1192 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len)
1194 const struct mbuf *m;
1203 count = min(m->m_len, len);
1204 bcopy(mtod(m, void *), dst, count);
1212 * Process the packet in the mbuf chain m. The packet is parsed by each
1213 * listener's filter, and if accepted, stashed into the corresponding
1217 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1224 lwkt_gettoken(&bpf_token);
1227 lwkt_reltoken(&bpf_token);
1231 /* Don't compute pktlen, if no descriptor is attached. */
1232 if (SLIST_EMPTY(&bp->bif_dlist)) {
1233 lwkt_reltoken(&bpf_token);
1237 pktlen = m_lengthm(m, NULL);
1239 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1240 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1243 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1249 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1253 lwkt_reltoken(&bpf_token);
1257 * Incoming linkage from device drivers, where we have a mbuf chain
1258 * but need to prepend some arbitrary header from a linear buffer.
1260 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1261 * struct m_hdr on the stack. This is safe as bpf only reads from the
1262 * fields in this header that we initialize, and will not try to free
1263 * it or keep a pointer to it.
1266 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m, u_int direction)
1275 return bpf_mtap(arg, (struct mbuf *) &mh);
1279 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1283 KKASSERT(family != AF_UNSPEC);
1285 family4 = (u_int)family;
1286 bpf_ptap(bp, m, &family4, sizeof(family4));
1290 * Process the packet in the mbuf chain m with the header in m prepended.
1291 * The packet is parsed by each listener's filter, and if accepted,
1292 * stashed into the corresponding buffer.
1295 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1300 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1301 * Note that we cut corners here; we only setup what's
1302 * absolutely needed--this mbuf should never go anywhere else.
1305 mb.m_data = __DECONST(void *, data); /* LINTED */
1307 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1313 * Move the packet data from interface memory (pkt) into the
1314 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1315 * otherwise 0. "copy" is the routine called to do the actual data
1316 * transfer. bcopy is passed in to copy contiguous chunks, while
1317 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1318 * pkt is really an mbuf.
1321 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1322 void (*cpfn)(const void *, void *, size_t),
1323 const struct timeval *tv)
1327 int hdrlen = d->bd_bif->bif_hdrlen;
1330 * Figure out how many bytes to move. If the packet is
1331 * greater or equal to the snapshot length, transfer that
1332 * much. Otherwise, transfer the whole packet (unless
1333 * we hit the buffer size limit).
1335 totlen = hdrlen + min(snaplen, pktlen);
1336 if (totlen > d->bd_bufsize)
1337 totlen = d->bd_bufsize;
1340 * Round up the end of the previous packet to the next longword.
1342 curlen = BPF_WORDALIGN(d->bd_slen);
1343 if (curlen + totlen > d->bd_bufsize) {
1345 * This packet will overflow the storage buffer.
1346 * Rotate the buffers if we can, then wakeup any
1349 if (d->bd_fbuf == NULL) {
1351 * We haven't completed the previous read yet,
1352 * so drop the packet.
1360 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1362 * Immediate mode is set, or the read timeout has
1363 * already expired during a select call. A packet
1364 * arrived, so the reader should be woken up.
1370 * Append the bpf header.
1372 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1373 hp->bh_tstamp = *tv;
1374 hp->bh_datalen = pktlen;
1375 hp->bh_hdrlen = hdrlen;
1377 * Copy the packet data into the store buffer and update its length.
1379 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1380 d->bd_slen = curlen + totlen;
1387 * Initialize all nonzero fields of a descriptor.
1390 bpf_allocbufs(struct bpf_d *d)
1392 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1393 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1400 * Free buffers and packet filter program currently in use by a descriptor.
1404 bpf_freed(struct bpf_d *d)
1407 * We don't need to lock out interrupts since this descriptor has
1408 * been detached from its interface and it yet hasn't been marked
1411 if (d->bd_sbuf != NULL) {
1412 kfree(d->bd_sbuf, M_BPF);
1413 if (d->bd_hbuf != NULL)
1414 kfree(d->bd_hbuf, M_BPF);
1415 if (d->bd_fbuf != NULL)
1416 kfree(d->bd_fbuf, M_BPF);
1419 kfree(d->bd_rfilter, M_BPF);
1421 kfree(d->bd_wfilter, M_BPF);
1425 * Attach an interface to bpf. ifp is a pointer to the structure
1426 * defining the interface to be attached, dlt is the link layer type,
1427 * and hdrlen is the fixed size of the link header (variable length
1428 * headers are not yet supported).
1431 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1433 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1437 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1441 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1443 lwkt_gettoken(&bpf_token);
1445 SLIST_INIT(&bp->bif_dlist);
1448 bp->bif_driverp = driverp;
1449 *bp->bif_driverp = NULL;
1451 bp->bif_next = bpf_iflist;
1455 * Compute the length of the bpf header. This is not necessarily
1456 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1457 * that the network layer header begins on a longword boundary (for
1458 * performance reasons and to alleviate alignment restrictions).
1460 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1462 lwkt_reltoken(&bpf_token);
1465 if_printf(ifp, "bpf attached\n");
1469 * Detach bpf from an interface. This involves detaching each descriptor
1470 * associated with the interface, and leaving bd_bif NULL. Notify each
1471 * descriptor as it's detached so that any sleepers wake up and get
1475 bpfdetach(struct ifnet *ifp)
1477 struct bpf_if *bp, *bp_prev;
1480 lwkt_gettoken(&bpf_token);
1482 /* Locate BPF interface information */
1484 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1485 if (ifp == bp->bif_ifp)
1490 /* Interface wasn't attached */
1491 if (bp->bif_ifp == NULL) {
1492 lwkt_reltoken(&bpf_token);
1493 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1497 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1502 if (bp_prev != NULL)
1503 bp_prev->bif_next = bp->bif_next;
1505 bpf_iflist = bp->bif_next;
1509 lwkt_reltoken(&bpf_token);
1513 * Get a list of available data link type of the interface.
1516 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1522 ifp = d->bd_bif->bif_ifp;
1525 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1526 if (bp->bif_ifp != ifp)
1528 if (bfl->bfl_list != NULL) {
1529 if (n >= bfl->bfl_len) {
1532 error = copyout(&bp->bif_dlt,
1533 bfl->bfl_list + n, sizeof(u_int));
1542 * Set the data link type of a BPF instance.
1545 bpf_setdlt(struct bpf_d *d, u_int dlt)
1547 int error, opromisc;
1551 if (d->bd_bif->bif_dlt == dlt)
1553 ifp = d->bd_bif->bif_ifp;
1554 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1555 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1559 opromisc = d->bd_promisc;
1564 error = ifpromisc(bp->bif_ifp, 1);
1566 if_printf(bp->bif_ifp,
1567 "bpf_setdlt: ifpromisc failed (%d)\n",
1574 return(bp == NULL ? EINVAL : 0);
1580 lwkt_gettoken(&bpf_token);
1586 lwkt_reltoken(&bpf_token);
1590 bpf_drvinit(void *unused)
1594 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1595 bpfclone, 0, 0, 0600, "bpf");
1596 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1597 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1598 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1603 bpf_drvuninit(void *unused)
1605 devfs_clone_handler_del("bpf");
1606 dev_ops_remove_all(&bpf_ops);
1607 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1610 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1611 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1615 * NOP stubs to allow bpf-using drivers to load and function.
1617 * A 'better' implementation would allow the core bpf functionality
1618 * to be loaded at runtime.
1622 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1627 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1632 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1637 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1642 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1647 bpfdetach(struct ifnet *ifp)
1652 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1654 return -1; /* "no filter" behaviour */