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(const void *, 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 (*)(const void *, void *, size_t),
125 const struct timeval *);
126 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
127 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
128 static int bpf_setdlt(struct bpf_d *, u_int);
129 static void bpf_drvinit(void *unused);
130 static void bpf_filter_detach(struct knote *kn);
131 static int bpf_filter_read(struct knote *kn, long hint);
133 static d_open_t bpfopen;
134 static d_clone_t bpfclone;
135 static d_close_t bpfclose;
136 static d_read_t bpfread;
137 static d_write_t bpfwrite;
138 static d_ioctl_t bpfioctl;
139 static d_kqfilter_t bpfkqfilter;
141 #define CDEV_MAJOR 23
142 static struct dev_ops bpf_ops = {
143 { "bpf", 0, D_MPSAFE },
149 .d_kqfilter = bpfkqfilter
154 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
155 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
157 const struct ieee80211_bpf_params *p;
168 * Build a sockaddr based on the data link layer type.
169 * We do this at this level because the ethernet header
170 * is copied directly into the data field of the sockaddr.
171 * In the case of SLIP, there is no header and the packet
172 * is forwarded as is.
173 * Also, we are careful to leave room at the front of the mbuf
174 * for the link level header.
178 sockp->sa_family = AF_INET;
183 sockp->sa_family = AF_UNSPEC;
184 /* XXX Would MAXLINKHDR be better? */
185 hlen = sizeof(struct ether_header);
190 sockp->sa_family = AF_UNSPEC;
194 case DLT_ATM_RFC1483:
196 * en atm driver requires 4-byte atm pseudo header.
197 * though it isn't standard, vpi:vci needs to be
200 sockp->sa_family = AF_UNSPEC;
201 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
205 sockp->sa_family = AF_UNSPEC;
206 hlen = 4; /* This should match PPP_HDRLEN */
209 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
210 sockp->sa_family = AF_IEEE80211;
214 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
215 sockp->sa_family = AF_IEEE80211;
216 sockp->sa_len = 12; /* XXX != 0 */
217 hlen = sizeof(struct ieee80211_bpf_params);
224 len = uio->uio_resid;
225 *datlen = len - hlen;
226 if ((unsigned)len > MCLBYTES)
229 m = m_getl(len, M_WAITOK, MT_DATA, M_PKTHDR, NULL);
232 m->m_pkthdr.len = m->m_len = len;
233 m->m_pkthdr.rcvif = NULL;
236 if (m->m_len < hlen) {
241 error = uiomove(mtod(m, u_char *), len, uio);
245 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
252 * Make room for link header, and copy it to sockaddr.
255 if (sockp->sa_family == AF_IEEE80211) {
257 * Collect true length from the parameter header
258 * NB: sockp is known to be zero'd so if we do a
259 * short copy unspecified parameters will be
261 * NB: packet may not be aligned after stripping
265 p = mtod(m, const struct ieee80211_bpf_params *);
267 if (hlen > sizeof(sockp->sa_data)) {
272 bcopy(m->m_data, sockp->sa_data, hlen);
273 m->m_pkthdr.len -= hlen;
275 m->m_data += hlen; /* XXX */
284 * Attach file to the bpf interface, i.e. make d listen on bp.
285 * Must be called at splimp.
288 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
291 * Point d at bp, and add d to the interface's list of listeners.
292 * Finally, point the driver's bpf cookie at the interface so
293 * it will divert packets to bpf.
295 lwkt_gettoken(&bpf_token);
297 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
298 *bp->bif_driverp = bp;
300 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
301 lwkt_reltoken(&bpf_token);
305 * Detach a file from its interface.
308 bpf_detachd(struct bpf_d *d)
314 lwkt_gettoken(&bpf_token);
318 /* Remove d from the interface's descriptor list. */
319 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
321 if (SLIST_EMPTY(&bp->bif_dlist)) {
323 * Let the driver know that there are no more listeners.
325 *bp->bif_driverp = NULL;
329 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
332 * Check if this descriptor had requested promiscuous mode.
333 * If so, turn it off.
337 error = ifpromisc(ifp, 0);
338 if (error != 0 && error != ENXIO) {
340 * ENXIO can happen if a pccard is unplugged,
341 * Something is really wrong if we were able to put
342 * the driver into promiscuous mode, but can't
345 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
349 lwkt_reltoken(&bpf_token);
353 * Open ethernet device. Returns ENXIO for illegal minor device number,
354 * EBUSY if file is open by another process.
358 bpfopen(struct dev_open_args *ap)
360 cdev_t dev = ap->a_head.a_dev;
363 lwkt_gettoken(&bpf_token);
364 if (ap->a_cred->cr_prison) {
365 lwkt_reltoken(&bpf_token);
371 * Each minor can be opened by only one process. If the requested
372 * minor is in use, return EBUSY.
375 lwkt_reltoken(&bpf_token);
379 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
381 d->bd_bufsize = bpf_bufsize;
384 callout_init(&d->bd_callout);
385 lwkt_reltoken(&bpf_token);
391 bpfclone(struct dev_clone_args *ap)
395 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
396 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
402 * Close the descriptor by detaching it from its interface,
403 * deallocating its buffers, and marking it free.
407 bpfclose(struct dev_close_args *ap)
409 cdev_t dev = ap->a_head.a_dev;
410 struct bpf_d *d = dev->si_drv1;
412 lwkt_gettoken(&bpf_token);
413 funsetown(&d->bd_sigio);
414 if (d->bd_state == BPF_WAITING)
415 callout_stop(&d->bd_callout);
416 d->bd_state = BPF_IDLE;
417 if (d->bd_bif != NULL)
421 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) {
422 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor);
426 lwkt_reltoken(&bpf_token);
432 * Rotate the packet buffers in descriptor d. Move the store buffer
433 * into the hold slot, and the free buffer into the store slot.
434 * Zero the length of the new store buffer.
436 #define ROTATE_BUFFERS(d) \
437 (d)->bd_hbuf = (d)->bd_sbuf; \
438 (d)->bd_hlen = (d)->bd_slen; \
439 (d)->bd_sbuf = (d)->bd_fbuf; \
443 * bpfread - read next chunk of packets from buffers
446 bpfread(struct dev_read_args *ap)
448 cdev_t dev = ap->a_head.a_dev;
449 struct bpf_d *d = dev->si_drv1;
453 lwkt_gettoken(&bpf_token);
455 * Restrict application to use a buffer the same size as
458 if (ap->a_uio->uio_resid != d->bd_bufsize) {
459 lwkt_reltoken(&bpf_token);
463 if (d->bd_state == BPF_WAITING)
464 callout_stop(&d->bd_callout);
465 timed_out = (d->bd_state == BPF_TIMED_OUT);
466 d->bd_state = BPF_IDLE;
468 * If the hold buffer is empty, then do a timed sleep, which
469 * ends when the timeout expires or when enough packets
470 * have arrived to fill the store buffer.
472 while (d->bd_hbuf == NULL) {
473 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
474 && d->bd_slen != 0) {
476 * A packet(s) either arrived since the previous,
477 * We're in immediate mode, or are reading
478 * in non-blocking mode, and a packet(s)
479 * either arrived since the previous
480 * read or arrived while we were asleep.
481 * Rotate the buffers and return what's here.
488 * No data is available, check to see if the bpf device
489 * is still pointed at a real interface. If not, return
490 * ENXIO so that the userland process knows to rebind
491 * it before using it again.
493 if (d->bd_bif == NULL) {
494 lwkt_reltoken(&bpf_token);
498 if (ap->a_ioflag & IO_NDELAY) {
499 lwkt_reltoken(&bpf_token);
502 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
503 if (error == EINTR || error == ERESTART) {
504 lwkt_reltoken(&bpf_token);
507 if (error == EWOULDBLOCK) {
509 * On a timeout, return what's in the buffer,
510 * which may be nothing. If there is something
511 * in the store buffer, we can rotate the buffers.
515 * We filled up the buffer in between
516 * getting the timeout and arriving
517 * here, so we don't need to rotate.
521 if (d->bd_slen == 0) {
522 lwkt_reltoken(&bpf_token);
530 * At this point, we know we have something in the hold slot.
534 * Move data from hold buffer into user space.
535 * We know the entire buffer is transferred since
536 * we checked above that the read buffer is bpf_bufsize bytes.
538 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
540 d->bd_fbuf = d->bd_hbuf;
543 lwkt_reltoken(&bpf_token);
550 * If there are processes sleeping on this descriptor, wake them up.
553 bpf_wakeup(struct bpf_d *d)
555 if (d->bd_state == BPF_WAITING) {
556 callout_stop(&d->bd_callout);
557 d->bd_state = BPF_IDLE;
560 if (d->bd_async && d->bd_sig && d->bd_sigio)
561 pgsigio(d->bd_sigio, d->bd_sig, 0);
563 KNOTE(&d->bd_kq.ki_note, 0);
567 bpf_timed_out(void *arg)
569 struct bpf_d *d = (struct bpf_d *)arg;
571 if (d->bd_state == BPF_WAITING) {
572 d->bd_state = BPF_TIMED_OUT;
579 bpf_output_dispatch(netmsg_t msg)
581 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
582 struct ifnet *ifp = bmsg->nm_ifp;
586 * The driver frees the mbuf.
588 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
589 lwkt_replymsg(&msg->lmsg, error);
593 bpfwrite(struct dev_write_args *ap)
595 cdev_t dev = ap->a_head.a_dev;
596 struct bpf_d *d = dev->si_drv1;
602 struct netmsg_bpf_output bmsg;
604 lwkt_gettoken(&bpf_token);
605 if (d->bd_bif == NULL) {
606 lwkt_reltoken(&bpf_token);
610 ifp = d->bd_bif->bif_ifp;
612 if (ap->a_uio->uio_resid == 0) {
613 lwkt_reltoken(&bpf_token);
617 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
618 &dst, &datlen, d->bd_wfilter);
620 lwkt_reltoken(&bpf_token);
624 if (datlen > ifp->if_mtu) {
626 lwkt_reltoken(&bpf_token);
631 dst.sa_family = pseudo_AF_HDRCMPLT;
633 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
634 0, bpf_output_dispatch);
639 ret = lwkt_domsg(netisr_cpuport(0), &bmsg.base.lmsg, 0);
640 lwkt_reltoken(&bpf_token);
646 * Reset a descriptor by flushing its packet buffer and clearing the
647 * receive and drop counts. Should be called at splimp.
650 bpf_resetd(struct bpf_d *d)
653 /* Free the hold buffer. */
654 d->bd_fbuf = d->bd_hbuf;
664 * FIONREAD Check for read packet available.
665 * SIOCGIFADDR Get interface address - convenient hook to driver.
666 * BIOCGBLEN Get buffer len [for read()].
667 * BIOCSETF Set ethernet read filter.
668 * BIOCSETWF Set ethernet write filter.
669 * BIOCFLUSH Flush read packet buffer.
670 * BIOCPROMISC Put interface into promiscuous mode.
671 * BIOCGDLT Get link layer type.
672 * BIOCGETIF Get interface name.
673 * BIOCSETIF Set interface.
674 * BIOCSRTIMEOUT Set read timeout.
675 * BIOCGRTIMEOUT Get read timeout.
676 * BIOCGSTATS Get packet stats.
677 * BIOCIMMEDIATE Set immediate mode.
678 * BIOCVERSION Get filter language version.
679 * BIOCGHDRCMPLT Get "header already complete" flag
680 * BIOCSHDRCMPLT Set "header already complete" flag
681 * BIOCGSEESENT Get "see packets sent" flag
682 * BIOCSSEESENT Set "see packets sent" flag
683 * BIOCLOCK Set "locked" flag
687 bpfioctl(struct dev_ioctl_args *ap)
689 cdev_t dev = ap->a_head.a_dev;
690 struct bpf_d *d = dev->si_drv1;
693 lwkt_gettoken(&bpf_token);
694 if (d->bd_state == BPF_WAITING)
695 callout_stop(&d->bd_callout);
696 d->bd_state = BPF_IDLE;
698 if (d->bd_locked == 1) {
717 lwkt_reltoken(&bpf_token);
727 * Check for read packet available.
737 *(int *)ap->a_data = n;
745 if (d->bd_bif == NULL) {
748 ifp = d->bd_bif->bif_ifp;
749 ifnet_serialize_all(ifp);
750 error = ifp->if_ioctl(ifp, ap->a_cmd,
751 ap->a_data, ap->a_cred);
752 ifnet_deserialize_all(ifp);
758 * Get buffer len [for read()].
761 *(u_int *)ap->a_data = d->bd_bufsize;
768 if (d->bd_bif != NULL) {
771 u_int size = *(u_int *)ap->a_data;
773 if (size > bpf_maxbufsize)
774 *(u_int *)ap->a_data = size = bpf_maxbufsize;
775 else if (size < BPF_MINBUFSIZE)
776 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
777 d->bd_bufsize = size;
782 * Set link layer read filter.
786 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
791 * Flush read packet buffer.
798 * Put interface into promiscuous mode.
801 if (d->bd_bif == NULL) {
803 * No interface attached yet.
808 if (d->bd_promisc == 0) {
809 error = ifpromisc(d->bd_bif->bif_ifp, 1);
816 * Get device parameters.
819 if (d->bd_bif == NULL)
822 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
826 * Get a list of supported data link types.
829 if (d->bd_bif == NULL) {
832 error = bpf_getdltlist(d,
833 (struct bpf_dltlist *)ap->a_data);
838 * Set data link type.
841 if (d->bd_bif == NULL)
844 error = bpf_setdlt(d, *(u_int *)ap->a_data);
848 * Get interface name.
851 if (d->bd_bif == NULL) {
854 struct ifnet *const ifp = d->bd_bif->bif_ifp;
855 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
857 strlcpy(ifr->ifr_name, ifp->if_xname,
858 sizeof ifr->ifr_name);
866 error = bpf_setif(d, (struct ifreq *)ap->a_data);
874 struct timeval *tv = (struct timeval *)ap->a_data;
877 * Subtract 1 tick from tvtohz() since this isn't
880 if ((error = itimerfix(tv)) == 0)
881 d->bd_rtout = tvtohz_low(tv);
890 struct timeval *tv = (struct timeval *)ap->a_data;
892 tv->tv_sec = d->bd_rtout / hz;
893 tv->tv_usec = (d->bd_rtout % hz) * ustick;
902 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
904 bs->bs_recv = d->bd_rcount;
905 bs->bs_drop = d->bd_dcount;
910 * Set immediate mode.
913 d->bd_immediate = *(u_int *)ap->a_data;
918 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
920 bv->bv_major = BPF_MAJOR_VERSION;
921 bv->bv_minor = BPF_MINOR_VERSION;
926 * Get "header already complete" flag
929 *(u_int *)ap->a_data = d->bd_hdrcmplt;
933 * Set "header already complete" flag
936 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
940 * Get "see sent packets" flag
943 *(u_int *)ap->a_data = d->bd_seesent;
947 * Set "see sent packets" flag
950 d->bd_seesent = *(u_int *)ap->a_data;
953 case FIOASYNC: /* Send signal on receive packets */
954 d->bd_async = *(int *)ap->a_data;
958 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
962 *(int *)ap->a_data = fgetown(&d->bd_sigio);
965 /* This is deprecated, FIOSETOWN should be used instead. */
967 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
970 /* This is deprecated, FIOGETOWN should be used instead. */
972 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
975 case BIOCSRSIG: /* Set receive signal */
979 sig = *(u_int *)ap->a_data;
988 *(u_int *)ap->a_data = d->bd_sig;
994 lwkt_reltoken(&bpf_token);
1000 * Set d's packet filter program to fp. If this file already has a filter,
1001 * free it and replace it. Returns EINVAL for bogus requests.
1004 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1006 struct bpf_insn *fcode, *old;
1007 u_int wfilter, flen, size;
1009 if (cmd == BIOCSETWF) {
1010 old = d->bd_wfilter;
1014 old = d->bd_rfilter;
1016 if (fp->bf_insns == NULL) {
1017 if (fp->bf_len != 0)
1020 d->bd_wfilter = NULL;
1022 d->bd_rfilter = NULL;
1029 if (flen > BPF_MAXINSNS)
1032 size = flen * sizeof *fp->bf_insns;
1033 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
1034 if (copyin(fp->bf_insns, fcode, size) == 0 &&
1035 bpf_validate(fcode, (int)flen)) {
1037 d->bd_wfilter = fcode;
1039 d->bd_rfilter = fcode;
1046 kfree(fcode, M_BPF);
1051 * Detach a file from its current interface (if attached at all) and attach
1052 * to the interface indicated by the name stored in ifr.
1053 * Return an errno or 0.
1056 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1060 struct ifnet *theywant;
1064 theywant = ifunit(ifr->ifr_name);
1065 if (theywant == NULL) {
1071 * Look through attached interfaces for the named one.
1073 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1074 struct ifnet *ifp = bp->bif_ifp;
1076 if (ifp == NULL || ifp != theywant)
1078 /* skip additional entry */
1079 if (bp->bif_driverp != &ifp->if_bpf)
1082 * We found the requested interface.
1083 * Allocate the packet buffers if we need to.
1084 * If we're already attached to requested interface,
1085 * just flush the buffer.
1087 if (d->bd_sbuf == NULL) {
1088 error = bpf_allocbufs(d);
1094 if (bp != d->bd_bif) {
1095 if (d->bd_bif != NULL) {
1097 * Detach if attached to something else.
1116 static struct filterops bpf_read_filtops =
1117 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1120 bpfkqfilter(struct dev_kqfilter_args *ap)
1122 cdev_t dev = ap->a_head.a_dev;
1123 struct knote *kn = ap->a_kn;
1124 struct klist *klist;
1127 lwkt_gettoken(&bpf_token);
1129 if (d->bd_bif == NULL) {
1131 lwkt_reltoken(&bpf_token);
1136 switch (kn->kn_filter) {
1138 kn->kn_fop = &bpf_read_filtops;
1139 kn->kn_hook = (caddr_t)d;
1142 ap->a_result = EOPNOTSUPP;
1143 lwkt_reltoken(&bpf_token);
1147 klist = &d->bd_kq.ki_note;
1148 knote_insert(klist, kn);
1149 lwkt_reltoken(&bpf_token);
1155 bpf_filter_detach(struct knote *kn)
1157 struct klist *klist;
1160 d = (struct bpf_d *)kn->kn_hook;
1161 klist = &d->bd_kq.ki_note;
1162 knote_remove(klist, kn);
1166 bpf_filter_read(struct knote *kn, long hint)
1171 d = (struct bpf_d *)kn->kn_hook;
1172 if (d->bd_hlen != 0 ||
1173 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1177 /* Start the read timeout if necessary. */
1178 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1179 callout_reset(&d->bd_callout, d->bd_rtout,
1181 d->bd_state = BPF_WAITING;
1190 * Process the packet pkt of length pktlen. The packet is parsed
1191 * by each listener's filter, and if accepted, stashed into the
1192 * corresponding buffer.
1195 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1202 lwkt_gettoken(&bpf_token);
1205 lwkt_reltoken(&bpf_token);
1210 * Note that the ipl does not have to be raised at this point.
1211 * The only problem that could arise here is that if two different
1212 * interfaces shared any data. This is not the case.
1214 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1216 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1222 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv);
1225 lwkt_reltoken(&bpf_token);
1229 * Copy data from an mbuf chain into a buffer. This code is derived
1230 * from m_copydata in sys/uipc_mbuf.c.
1233 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len)
1235 const struct mbuf *m;
1244 count = min(m->m_len, len);
1245 bcopy(mtod(m, void *), dst, count);
1253 * Process the packet in the mbuf chain m. The packet is parsed by each
1254 * listener's filter, and if accepted, stashed into the corresponding
1258 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1265 lwkt_gettoken(&bpf_token);
1268 lwkt_reltoken(&bpf_token);
1272 /* Don't compute pktlen, if no descriptor is attached. */
1273 if (SLIST_EMPTY(&bp->bif_dlist)) {
1274 lwkt_reltoken(&bpf_token);
1278 pktlen = m_lengthm(m, NULL);
1280 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1281 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1284 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1290 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1294 lwkt_reltoken(&bpf_token);
1298 * Incoming linkage from device drivers, where we have a mbuf chain
1299 * but need to prepend some arbitrary header from a linear buffer.
1301 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1302 * struct m_hdr on the stack. This is safe as bpf only reads from the
1303 * fields in this header that we initialize, and will not try to free
1304 * it or keep a pointer to it.
1307 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m,
1317 bpf_mtap(arg, (struct mbuf *) &mh);
1321 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1325 KKASSERT(family != AF_UNSPEC);
1327 family4 = (u_int)family;
1328 bpf_ptap(bp, m, &family4, sizeof(family4));
1332 * Process the packet in the mbuf chain m with the header in m prepended.
1333 * The packet is parsed by each listener's filter, and if accepted,
1334 * stashed into the corresponding buffer.
1337 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1342 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1343 * Note that we cut corners here; we only setup what's
1344 * absolutely needed--this mbuf should never go anywhere else.
1347 mb.m_data = __DECONST(void *, data); /* LINTED */
1349 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1355 * Move the packet data from interface memory (pkt) into the
1356 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1357 * otherwise 0. "copy" is the routine called to do the actual data
1358 * transfer. bcopy is passed in to copy contiguous chunks, while
1359 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1360 * pkt is really an mbuf.
1363 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1364 void (*cpfn)(const void *, void *, size_t),
1365 const struct timeval *tv)
1369 int hdrlen = d->bd_bif->bif_hdrlen;
1372 * Figure out how many bytes to move. If the packet is
1373 * greater or equal to the snapshot length, transfer that
1374 * much. Otherwise, transfer the whole packet (unless
1375 * we hit the buffer size limit).
1377 totlen = hdrlen + min(snaplen, pktlen);
1378 if (totlen > d->bd_bufsize)
1379 totlen = d->bd_bufsize;
1382 * Round up the end of the previous packet to the next longword.
1384 curlen = BPF_WORDALIGN(d->bd_slen);
1385 if (curlen + totlen > d->bd_bufsize) {
1387 * This packet will overflow the storage buffer.
1388 * Rotate the buffers if we can, then wakeup any
1391 if (d->bd_fbuf == NULL) {
1393 * We haven't completed the previous read yet,
1394 * so drop the packet.
1402 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1404 * Immediate mode is set, or the read timeout has
1405 * already expired during a select call. A packet
1406 * arrived, so the reader should be woken up.
1412 * Append the bpf header.
1414 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1415 hp->bh_tstamp = *tv;
1416 hp->bh_datalen = pktlen;
1417 hp->bh_hdrlen = hdrlen;
1419 * Copy the packet data into the store buffer and update its length.
1421 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1422 d->bd_slen = curlen + totlen;
1429 * Initialize all nonzero fields of a descriptor.
1432 bpf_allocbufs(struct bpf_d *d)
1434 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1435 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1442 * Free buffers and packet filter program currently in use by a descriptor.
1446 bpf_freed(struct bpf_d *d)
1449 * We don't need to lock out interrupts since this descriptor has
1450 * been detached from its interface and it yet hasn't been marked
1453 if (d->bd_sbuf != NULL) {
1454 kfree(d->bd_sbuf, M_BPF);
1455 if (d->bd_hbuf != NULL)
1456 kfree(d->bd_hbuf, M_BPF);
1457 if (d->bd_fbuf != NULL)
1458 kfree(d->bd_fbuf, M_BPF);
1461 kfree(d->bd_rfilter, M_BPF);
1463 kfree(d->bd_wfilter, M_BPF);
1467 * Attach an interface to bpf. ifp is a pointer to the structure
1468 * defining the interface to be attached, dlt is the link layer type,
1469 * and hdrlen is the fixed size of the link header (variable length
1470 * headers are not yet supported).
1473 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1475 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1479 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1483 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1485 lwkt_gettoken(&bpf_token);
1487 SLIST_INIT(&bp->bif_dlist);
1490 bp->bif_driverp = driverp;
1491 *bp->bif_driverp = NULL;
1493 bp->bif_next = bpf_iflist;
1497 * Compute the length of the bpf header. This is not necessarily
1498 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1499 * that the network layer header begins on a longword boundary (for
1500 * performance reasons and to alleviate alignment restrictions).
1502 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1504 lwkt_reltoken(&bpf_token);
1507 if_printf(ifp, "bpf attached\n");
1511 * Detach bpf from an interface. This involves detaching each descriptor
1512 * associated with the interface, and leaving bd_bif NULL. Notify each
1513 * descriptor as it's detached so that any sleepers wake up and get
1517 bpfdetach(struct ifnet *ifp)
1519 struct bpf_if *bp, *bp_prev;
1522 lwkt_gettoken(&bpf_token);
1524 /* Locate BPF interface information */
1526 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1527 if (ifp == bp->bif_ifp)
1532 /* Interface wasn't attached */
1533 if (bp->bif_ifp == NULL) {
1534 lwkt_reltoken(&bpf_token);
1535 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1539 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1544 if (bp_prev != NULL)
1545 bp_prev->bif_next = bp->bif_next;
1547 bpf_iflist = bp->bif_next;
1551 lwkt_reltoken(&bpf_token);
1555 * Get a list of available data link type of the interface.
1558 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1564 ifp = d->bd_bif->bif_ifp;
1567 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1568 if (bp->bif_ifp != ifp)
1570 if (bfl->bfl_list != NULL) {
1571 if (n >= bfl->bfl_len) {
1574 error = copyout(&bp->bif_dlt,
1575 bfl->bfl_list + n, sizeof(u_int));
1584 * Set the data link type of a BPF instance.
1587 bpf_setdlt(struct bpf_d *d, u_int dlt)
1589 int error, opromisc;
1593 if (d->bd_bif->bif_dlt == dlt)
1595 ifp = d->bd_bif->bif_ifp;
1596 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1597 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1601 opromisc = d->bd_promisc;
1606 error = ifpromisc(bp->bif_ifp, 1);
1608 if_printf(bp->bif_ifp,
1609 "bpf_setdlt: ifpromisc failed (%d)\n",
1616 return(bp == NULL ? EINVAL : 0);
1622 lwkt_gettoken(&bpf_token);
1628 lwkt_reltoken(&bpf_token);
1632 bpf_drvinit(void *unused)
1636 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1637 bpfclone, 0, 0, 0600, "bpf");
1638 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1639 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1640 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1645 bpf_drvuninit(void *unused)
1647 devfs_clone_handler_del("bpf");
1648 dev_ops_remove_all(&bpf_ops);
1649 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1652 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR, bpf_drvinit, NULL);
1653 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1657 * NOP stubs to allow bpf-using drivers to load and function.
1659 * A 'better' implementation would allow the core bpf functionality
1660 * to be loaded at runtime.
1664 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1669 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1674 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1679 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1684 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1689 bpfdetach(struct ifnet *ifp)
1694 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1696 return -1; /* "no filter" behaviour */