2 * Copyright (c) 1990, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from the Stanford/CMU enet packet filter,
6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#)bpf.c 8.2 (Berkeley) 3/28/94
40 * $FreeBSD: src/sys/net/bpf.c,v 1.59.2.12 2002/04/14 21:41:48 luigi Exp $
45 #include <sys/param.h>
46 #include <sys/systm.h>
48 #include <sys/device.h>
49 #include <sys/malloc.h>
53 #include <sys/signalvar.h>
54 #include <sys/filio.h>
55 #include <sys/sockio.h>
56 #include <sys/ttycom.h>
57 #include <sys/filedesc.h>
59 #include <sys/event.h>
61 #include <sys/socket.h>
62 #include <sys/vnode.h>
64 #include <sys/thread2.h>
65 #include <sys/mplock2.h>
69 #include <net/bpfdesc.h>
70 #include <net/netmsg2.h>
72 #include <netinet/in.h>
73 #include <netinet/if_ether.h>
74 #include <sys/kernel.h>
75 #include <sys/sysctl.h>
77 #include <sys/devfs.h>
79 struct netmsg_bpf_output {
80 struct netmsg_base base;
83 struct sockaddr *nm_dst;
86 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
87 DEVFS_DECLARE_CLONE_BITMAP(bpf);
90 #define BPF_PREALLOCATED_UNITS 4
92 #define BPF_PREALLOCATED_UNITS NBPF
98 * The default read buffer size is patchable.
100 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
101 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
102 &bpf_bufsize, 0, "Current size of bpf buffer");
103 int bpf_maxbufsize = BPF_MAXBUFSIZE;
104 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
105 &bpf_maxbufsize, 0, "Maximum size of bpf buffer");
108 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
110 static struct bpf_if *bpf_iflist;
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 = {
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)
167 * Build a sockaddr based on the data link layer type.
168 * We do this at this level because the ethernet header
169 * is copied directly into the data field of the sockaddr.
170 * In the case of SLIP, there is no header and the packet
171 * is forwarded as is.
172 * Also, we are careful to leave room at the front of the mbuf
173 * for the link level header.
177 sockp->sa_family = AF_INET;
182 sockp->sa_family = AF_UNSPEC;
183 /* XXX Would MAXLINKHDR be better? */
184 hlen = sizeof(struct ether_header);
189 sockp->sa_family = AF_UNSPEC;
193 case DLT_ATM_RFC1483:
195 * en atm driver requires 4-byte atm pseudo header.
196 * though it isn't standard, vpi:vci needs to be
199 sockp->sa_family = AF_UNSPEC;
200 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
204 sockp->sa_family = AF_UNSPEC;
205 hlen = 4; /* This should match PPP_HDRLEN */
212 len = uio->uio_resid;
213 *datlen = len - hlen;
214 if ((unsigned)len > MCLBYTES)
217 m = m_getl(len, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
220 m->m_pkthdr.len = m->m_len = len;
221 m->m_pkthdr.rcvif = NULL;
224 if (m->m_len < hlen) {
229 error = uiomove(mtod(m, u_char *), len, uio);
233 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
240 * Make room for link header, and copy it to sockaddr.
243 bcopy(m->m_data, sockp->sa_data, hlen);
244 m->m_pkthdr.len -= hlen;
246 m->m_data += hlen; /* XXX */
255 * Attach file to the bpf interface, i.e. make d listen on bp.
256 * Must be called at splimp.
259 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
262 * Point d at bp, and add d to the interface's list of listeners.
263 * Finally, point the driver's bpf cookie at the interface so
264 * it will divert packets to bpf.
267 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
268 *bp->bif_driverp = bp;
270 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
274 * Detach a file from its interface.
277 bpf_detachd(struct bpf_d *d)
286 /* Remove d from the interface's descriptor list. */
287 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
289 if (SLIST_EMPTY(&bp->bif_dlist)) {
291 * Let the driver know that there are no more listeners.
293 *bp->bif_driverp = NULL;
297 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
300 * Check if this descriptor had requested promiscuous mode.
301 * If so, turn it off.
305 error = ifpromisc(ifp, 0);
306 if (error != 0 && error != ENXIO) {
308 * ENXIO can happen if a pccard is unplugged,
309 * Something is really wrong if we were able to put
310 * the driver into promiscuous mode, but can't
313 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
320 * Open ethernet device. Returns ENXIO for illegal minor device number,
321 * EBUSY if file is open by another process.
325 bpfopen(struct dev_open_args *ap)
327 cdev_t dev = ap->a_head.a_dev;
330 if (ap->a_cred->cr_prison)
335 * Each minor can be opened by only one process. If the requested
336 * minor is in use, return EBUSY.
341 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
343 d->bd_bufsize = bpf_bufsize;
346 callout_init(&d->bd_callout);
351 bpfclone(struct dev_clone_args *ap)
355 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
356 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
362 * Close the descriptor by detaching it from its interface,
363 * deallocating its buffers, and marking it free.
367 bpfclose(struct dev_close_args *ap)
369 cdev_t dev = ap->a_head.a_dev;
370 struct bpf_d *d = dev->si_drv1;
372 funsetown(&d->bd_sigio);
374 if (d->bd_state == BPF_WAITING)
375 callout_stop(&d->bd_callout);
376 d->bd_state = BPF_IDLE;
377 if (d->bd_bif != NULL)
382 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) {
383 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor);
391 * Rotate the packet buffers in descriptor d. Move the store buffer
392 * into the hold slot, and the free buffer into the store slot.
393 * Zero the length of the new store buffer.
395 #define ROTATE_BUFFERS(d) \
396 (d)->bd_hbuf = (d)->bd_sbuf; \
397 (d)->bd_hlen = (d)->bd_slen; \
398 (d)->bd_sbuf = (d)->bd_fbuf; \
402 * bpfread - read next chunk of packets from buffers
405 bpfread(struct dev_read_args *ap)
407 cdev_t dev = ap->a_head.a_dev;
408 struct bpf_d *d = dev->si_drv1;
413 * Restrict application to use a buffer the same size as
416 if (ap->a_uio->uio_resid != d->bd_bufsize)
420 if (d->bd_state == BPF_WAITING)
421 callout_stop(&d->bd_callout);
422 timed_out = (d->bd_state == BPF_TIMED_OUT);
423 d->bd_state = BPF_IDLE;
425 * If the hold buffer is empty, then do a timed sleep, which
426 * ends when the timeout expires or when enough packets
427 * have arrived to fill the store buffer.
429 while (d->bd_hbuf == NULL) {
430 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
431 && d->bd_slen != 0) {
433 * A packet(s) either arrived since the previous,
434 * We're in immediate mode, or are reading
435 * in non-blocking mode, and a packet(s)
436 * either arrived since the previous
437 * read or arrived while we were asleep.
438 * Rotate the buffers and return what's here.
445 * No data is available, check to see if the bpf device
446 * is still pointed at a real interface. If not, return
447 * ENXIO so that the userland process knows to rebind
448 * it before using it again.
450 if (d->bd_bif == NULL) {
455 if (ap->a_ioflag & IO_NDELAY) {
459 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
460 if (error == EINTR || error == ERESTART) {
464 if (error == EWOULDBLOCK) {
466 * On a timeout, return what's in the buffer,
467 * which may be nothing. If there is something
468 * in the store buffer, we can rotate the buffers.
472 * We filled up the buffer in between
473 * getting the timeout and arriving
474 * here, so we don't need to rotate.
478 if (d->bd_slen == 0) {
487 * At this point, we know we have something in the hold slot.
492 * Move data from hold buffer into user space.
493 * We know the entire buffer is transferred since
494 * we checked above that the read buffer is bpf_bufsize bytes.
496 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
499 d->bd_fbuf = d->bd_hbuf;
509 * If there are processes sleeping on this descriptor, wake them up.
512 bpf_wakeup(struct bpf_d *d)
514 if (d->bd_state == BPF_WAITING) {
515 callout_stop(&d->bd_callout);
516 d->bd_state = BPF_IDLE;
519 if (d->bd_async && d->bd_sig && d->bd_sigio)
520 pgsigio(d->bd_sigio, d->bd_sig, 0);
523 KNOTE(&d->bd_kq.ki_note, 0);
528 bpf_timed_out(void *arg)
530 struct bpf_d *d = (struct bpf_d *)arg;
533 if (d->bd_state == BPF_WAITING) {
534 d->bd_state = BPF_TIMED_OUT;
542 bpf_output_dispatch(netmsg_t msg)
544 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
545 struct ifnet *ifp = bmsg->nm_ifp;
549 * The driver frees the mbuf.
551 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
552 lwkt_replymsg(&msg->lmsg, error);
556 bpfwrite(struct dev_write_args *ap)
558 cdev_t dev = ap->a_head.a_dev;
559 struct bpf_d *d = dev->si_drv1;
565 struct netmsg_bpf_output bmsg;
567 if (d->bd_bif == NULL)
570 ifp = d->bd_bif->bif_ifp;
572 if (ap->a_uio->uio_resid == 0)
575 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
576 &dst, &datlen, d->bd_wfilter);
580 if (datlen > ifp->if_mtu) {
586 dst.sa_family = pseudo_AF_HDRCMPLT;
588 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
589 0, bpf_output_dispatch);
594 return lwkt_domsg(netisr_portfn(0), &bmsg.base.lmsg, 0);
598 * Reset a descriptor by flushing its packet buffer and clearing the
599 * receive and drop counts. Should be called at splimp.
602 bpf_resetd(struct bpf_d *d)
605 /* Free the hold buffer. */
606 d->bd_fbuf = d->bd_hbuf;
616 * FIONREAD Check for read packet available.
617 * SIOCGIFADDR Get interface address - convenient hook to driver.
618 * BIOCGBLEN Get buffer len [for read()].
619 * BIOCSETF Set ethernet read filter.
620 * BIOCSETWF Set ethernet write filter.
621 * BIOCFLUSH Flush read packet buffer.
622 * BIOCPROMISC Put interface into promiscuous mode.
623 * BIOCGDLT Get link layer type.
624 * BIOCGETIF Get interface name.
625 * BIOCSETIF Set interface.
626 * BIOCSRTIMEOUT Set read timeout.
627 * BIOCGRTIMEOUT Get read timeout.
628 * BIOCGSTATS Get packet stats.
629 * BIOCIMMEDIATE Set immediate mode.
630 * BIOCVERSION Get filter language version.
631 * BIOCGHDRCMPLT Get "header already complete" flag
632 * BIOCSHDRCMPLT Set "header already complete" flag
633 * BIOCGSEESENT Get "see packets sent" flag
634 * BIOCSSEESENT Set "see packets sent" flag
635 * BIOCLOCK Set "locked" flag
639 bpfioctl(struct dev_ioctl_args *ap)
641 cdev_t dev = ap->a_head.a_dev;
642 struct bpf_d *d = dev->si_drv1;
646 if (d->bd_state == BPF_WAITING)
647 callout_stop(&d->bd_callout);
648 d->bd_state = BPF_IDLE;
651 if (d->bd_locked == 1) {
679 * Check for read packet available.
691 *(int *)ap->a_data = n;
699 if (d->bd_bif == NULL) {
702 ifp = d->bd_bif->bif_ifp;
703 ifnet_serialize_all(ifp);
704 error = ifp->if_ioctl(ifp, ap->a_cmd,
705 ap->a_data, ap->a_cred);
706 ifnet_deserialize_all(ifp);
712 * Get buffer len [for read()].
715 *(u_int *)ap->a_data = d->bd_bufsize;
722 if (d->bd_bif != NULL) {
725 u_int size = *(u_int *)ap->a_data;
727 if (size > bpf_maxbufsize)
728 *(u_int *)ap->a_data = size = bpf_maxbufsize;
729 else if (size < BPF_MINBUFSIZE)
730 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
731 d->bd_bufsize = size;
736 * Set link layer read filter.
740 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
745 * Flush read packet buffer.
754 * Put interface into promiscuous mode.
757 if (d->bd_bif == NULL) {
759 * No interface attached yet.
765 if (d->bd_promisc == 0) {
766 error = ifpromisc(d->bd_bif->bif_ifp, 1);
774 * Get device parameters.
777 if (d->bd_bif == NULL)
780 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
784 * Get a list of supported data link types.
787 if (d->bd_bif == NULL) {
790 error = bpf_getdltlist(d,
791 (struct bpf_dltlist *)ap->a_data);
796 * Set data link type.
799 if (d->bd_bif == NULL)
802 error = bpf_setdlt(d, *(u_int *)ap->a_data);
806 * Get interface name.
809 if (d->bd_bif == NULL) {
812 struct ifnet *const ifp = d->bd_bif->bif_ifp;
813 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
815 strlcpy(ifr->ifr_name, ifp->if_xname,
816 sizeof ifr->ifr_name);
824 error = bpf_setif(d, (struct ifreq *)ap->a_data);
832 struct timeval *tv = (struct timeval *)ap->a_data;
835 * Subtract 1 tick from tvtohz() since this isn't
838 if ((error = itimerfix(tv)) == 0)
839 d->bd_rtout = tvtohz_low(tv);
848 struct timeval *tv = (struct timeval *)ap->a_data;
850 tv->tv_sec = d->bd_rtout / hz;
851 tv->tv_usec = (d->bd_rtout % hz) * ustick;
860 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
862 bs->bs_recv = d->bd_rcount;
863 bs->bs_drop = d->bd_dcount;
868 * Set immediate mode.
871 d->bd_immediate = *(u_int *)ap->a_data;
876 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
878 bv->bv_major = BPF_MAJOR_VERSION;
879 bv->bv_minor = BPF_MINOR_VERSION;
884 * Get "header already complete" flag
887 *(u_int *)ap->a_data = d->bd_hdrcmplt;
891 * Set "header already complete" flag
894 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
898 * Get "see sent packets" flag
901 *(u_int *)ap->a_data = d->bd_seesent;
905 * Set "see sent packets" flag
908 d->bd_seesent = *(u_int *)ap->a_data;
911 case FIOASYNC: /* Send signal on receive packets */
912 d->bd_async = *(int *)ap->a_data;
916 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
920 *(int *)ap->a_data = fgetown(&d->bd_sigio);
923 /* This is deprecated, FIOSETOWN should be used instead. */
925 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
928 /* This is deprecated, FIOGETOWN should be used instead. */
930 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
933 case BIOCSRSIG: /* Set receive signal */
937 sig = *(u_int *)ap->a_data;
946 *(u_int *)ap->a_data = d->bd_sig;
956 * Set d's packet filter program to fp. If this file already has a filter,
957 * free it and replace it. Returns EINVAL for bogus requests.
960 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
962 struct bpf_insn *fcode, *old;
963 u_int wfilter, flen, size;
965 if (cmd == BIOCSETWF) {
972 if (fp->bf_insns == NULL) {
977 d->bd_wfilter = NULL;
979 d->bd_rfilter = NULL;
987 if (flen > BPF_MAXINSNS)
990 size = flen * sizeof *fp->bf_insns;
991 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
992 if (copyin(fp->bf_insns, fcode, size) == 0 &&
993 bpf_validate(fcode, (int)flen)) {
996 d->bd_wfilter = fcode;
998 d->bd_rfilter = fcode;
1006 kfree(fcode, M_BPF);
1011 * Detach a file from its current interface (if attached at all) and attach
1012 * to the interface indicated by the name stored in ifr.
1013 * Return an errno or 0.
1016 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1020 struct ifnet *theywant;
1022 theywant = ifunit(ifr->ifr_name);
1023 if (theywant == NULL)
1027 * Look through attached interfaces for the named one.
1029 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1030 struct ifnet *ifp = bp->bif_ifp;
1032 if (ifp == NULL || ifp != theywant)
1034 /* skip additional entry */
1035 if (bp->bif_driverp != &ifp->if_bpf)
1038 * We found the requested interface.
1039 * Allocate the packet buffers if we need to.
1040 * If we're already attached to requested interface,
1041 * just flush the buffer.
1043 if (d->bd_sbuf == NULL) {
1044 error = bpf_allocbufs(d);
1049 if (bp != d->bd_bif) {
1050 if (d->bd_bif != NULL) {
1052 * Detach if attached to something else.
1068 static struct filterops bpf_read_filtops =
1069 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1072 bpfkqfilter(struct dev_kqfilter_args *ap)
1074 cdev_t dev = ap->a_head.a_dev;
1075 struct knote *kn = ap->a_kn;
1076 struct klist *klist;
1080 if (d->bd_bif == NULL) {
1086 switch (kn->kn_filter) {
1088 kn->kn_fop = &bpf_read_filtops;
1089 kn->kn_hook = (caddr_t)d;
1092 ap->a_result = EOPNOTSUPP;
1096 klist = &d->bd_kq.ki_note;
1097 knote_insert(klist, kn);
1103 bpf_filter_detach(struct knote *kn)
1105 struct klist *klist;
1108 d = (struct bpf_d *)kn->kn_hook;
1109 klist = &d->bd_kq.ki_note;
1110 knote_remove(klist, kn);
1114 bpf_filter_read(struct knote *kn, long hint)
1120 d = (struct bpf_d *)kn->kn_hook;
1121 if (d->bd_hlen != 0 ||
1122 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1126 /* Start the read timeout if necessary. */
1127 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1128 callout_reset(&d->bd_callout, d->bd_rtout,
1130 d->bd_state = BPF_WAITING;
1140 * Process the packet pkt of length pktlen. The packet is parsed
1141 * by each listener's filter, and if accepted, stashed into the
1142 * corresponding buffer.
1145 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1161 * Note that the ipl does not have to be raised at this point.
1162 * The only problem that could arise here is that if two different
1163 * interfaces shared any data. This is not the case.
1165 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1167 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1173 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv);
1181 * Copy data from an mbuf chain into a buffer. This code is derived
1182 * from m_copydata in sys/uipc_mbuf.c.
1185 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len)
1187 const struct mbuf *m;
1196 count = min(m->m_len, len);
1197 bcopy(mtod(m, void *), dst, count);
1205 * Process the packet in the mbuf chain m. The packet is parsed by each
1206 * listener's filter, and if accepted, stashed into the corresponding
1210 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1225 /* Don't compute pktlen, if no descriptor is attached. */
1226 if (SLIST_EMPTY(&bp->bif_dlist)) {
1231 pktlen = m_lengthm(m, NULL);
1233 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1234 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1237 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1243 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1252 * Incoming linkage from device drivers, where we have a mbuf chain
1253 * but need to prepend some arbitrary header from a linear buffer.
1255 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1256 * struct m_hdr on the stack. This is safe as bpf only reads from the
1257 * fields in this header that we initialize, and will not try to free
1258 * it or keep a pointer to it.
1261 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m, u_int direction)
1270 return bpf_mtap(arg, (struct mbuf *) &mh);
1274 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1278 KKASSERT(family != AF_UNSPEC);
1280 family4 = (u_int)family;
1281 bpf_ptap(bp, m, &family4, sizeof(family4));
1285 * Process the packet in the mbuf chain m with the header in m prepended.
1286 * The packet is parsed by each listener's filter, and if accepted,
1287 * stashed into the corresponding buffer.
1290 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1295 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1296 * Note that we cut corners here; we only setup what's
1297 * absolutely needed--this mbuf should never go anywhere else.
1300 mb.m_data = __DECONST(void *, data); /* LINTED */
1302 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1308 * Move the packet data from interface memory (pkt) into the
1309 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1310 * otherwise 0. "copy" is the routine called to do the actual data
1311 * transfer. bcopy is passed in to copy contiguous chunks, while
1312 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1313 * pkt is really an mbuf.
1316 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1317 void (*cpfn)(const void *, void *, size_t),
1318 const struct timeval *tv)
1322 int hdrlen = d->bd_bif->bif_hdrlen;
1325 * Figure out how many bytes to move. If the packet is
1326 * greater or equal to the snapshot length, transfer that
1327 * much. Otherwise, transfer the whole packet (unless
1328 * we hit the buffer size limit).
1330 totlen = hdrlen + min(snaplen, pktlen);
1331 if (totlen > d->bd_bufsize)
1332 totlen = d->bd_bufsize;
1335 * Round up the end of the previous packet to the next longword.
1337 curlen = BPF_WORDALIGN(d->bd_slen);
1338 if (curlen + totlen > d->bd_bufsize) {
1340 * This packet will overflow the storage buffer.
1341 * Rotate the buffers if we can, then wakeup any
1344 if (d->bd_fbuf == NULL) {
1346 * We haven't completed the previous read yet,
1347 * so drop the packet.
1355 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1357 * Immediate mode is set, or the read timeout has
1358 * already expired during a select call. A packet
1359 * arrived, so the reader should be woken up.
1365 * Append the bpf header.
1367 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1368 hp->bh_tstamp = *tv;
1369 hp->bh_datalen = pktlen;
1370 hp->bh_hdrlen = hdrlen;
1372 * Copy the packet data into the store buffer and update its length.
1374 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1375 d->bd_slen = curlen + totlen;
1382 * Initialize all nonzero fields of a descriptor.
1385 bpf_allocbufs(struct bpf_d *d)
1387 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1388 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1395 * Free buffers and packet filter program currently in use by a descriptor.
1399 bpf_freed(struct bpf_d *d)
1402 * We don't need to lock out interrupts since this descriptor has
1403 * been detached from its interface and it yet hasn't been marked
1406 if (d->bd_sbuf != NULL) {
1407 kfree(d->bd_sbuf, M_BPF);
1408 if (d->bd_hbuf != NULL)
1409 kfree(d->bd_hbuf, M_BPF);
1410 if (d->bd_fbuf != NULL)
1411 kfree(d->bd_fbuf, M_BPF);
1414 kfree(d->bd_rfilter, M_BPF);
1416 kfree(d->bd_wfilter, M_BPF);
1420 * Attach an interface to bpf. ifp is a pointer to the structure
1421 * defining the interface to be attached, dlt is the link layer type,
1422 * and hdrlen is the fixed size of the link header (variable length
1423 * headers are not yet supported).
1426 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1428 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1432 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1436 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1438 SLIST_INIT(&bp->bif_dlist);
1441 bp->bif_driverp = driverp;
1442 *bp->bif_driverp = NULL;
1444 bp->bif_next = bpf_iflist;
1448 * Compute the length of the bpf header. This is not necessarily
1449 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1450 * that the network layer header begins on a longword boundary (for
1451 * performance reasons and to alleviate alignment restrictions).
1453 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1456 if_printf(ifp, "bpf attached\n");
1460 * Detach bpf from an interface. This involves detaching each descriptor
1461 * associated with the interface, and leaving bd_bif NULL. Notify each
1462 * descriptor as it's detached so that any sleepers wake up and get
1466 bpfdetach(struct ifnet *ifp)
1468 struct bpf_if *bp, *bp_prev;
1473 /* Locate BPF interface information */
1475 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1476 if (ifp == bp->bif_ifp)
1481 /* Interface wasn't attached */
1482 if (bp->bif_ifp == NULL) {
1484 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1488 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1493 if (bp_prev != NULL)
1494 bp_prev->bif_next = bp->bif_next;
1496 bpf_iflist = bp->bif_next;
1504 * Get a list of available data link type of the interface.
1507 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1513 ifp = d->bd_bif->bif_ifp;
1516 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1517 if (bp->bif_ifp != ifp)
1519 if (bfl->bfl_list != NULL) {
1520 if (n >= bfl->bfl_len) {
1523 error = copyout(&bp->bif_dlt,
1524 bfl->bfl_list + n, sizeof(u_int));
1533 * Set the data link type of a BPF instance.
1536 bpf_setdlt(struct bpf_d *d, u_int dlt)
1538 int error, opromisc;
1542 if (d->bd_bif->bif_dlt == dlt)
1544 ifp = d->bd_bif->bif_ifp;
1545 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1546 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1550 opromisc = d->bd_promisc;
1556 error = ifpromisc(bp->bif_ifp, 1);
1558 if_printf(bp->bif_ifp,
1559 "bpf_setdlt: ifpromisc failed (%d)\n",
1567 return(bp == NULL ? EINVAL : 0);
1571 bpf_drvinit(void *unused)
1575 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1576 bpfclone, 0, 0, 0600, "bpf");
1577 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1578 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1579 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1584 bpf_drvuninit(void *unused)
1586 devfs_clone_handler_del("bpf");
1587 dev_ops_remove_all(&bpf_ops);
1588 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1591 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1592 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1596 * NOP stubs to allow bpf-using drivers to load and function.
1598 * A 'better' implementation would allow the core bpf functionality
1599 * to be loaded at runtime.
1603 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1608 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1613 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1618 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1623 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1628 bpfdetach(struct ifnet *ifp)
1633 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1635 return -1; /* "no filter" behaviour */