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 $
41 * $DragonFly: src/sys/net/bpf.c,v 1.50 2008/09/23 11:28:49 sephe Exp $
46 #include <sys/param.h>
47 #include <sys/systm.h>
49 #include <sys/device.h>
50 #include <sys/malloc.h>
54 #include <sys/signalvar.h>
55 #include <sys/filio.h>
56 #include <sys/sockio.h>
57 #include <sys/ttycom.h>
58 #include <sys/filedesc.h>
60 #include <sys/event.h>
62 #include <sys/socket.h>
63 #include <sys/vnode.h>
65 #include <sys/thread2.h>
66 #include <sys/mplock2.h>
70 #include <net/bpfdesc.h>
71 #include <net/netmsg2.h>
73 #include <netinet/in.h>
74 #include <netinet/if_ether.h>
75 #include <sys/kernel.h>
76 #include <sys/sysctl.h>
78 #include <sys/devfs.h>
80 struct netmsg_bpf_output {
81 struct netmsg nm_netmsg;
84 struct sockaddr *nm_dst;
87 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
88 DEVFS_DECLARE_CLONE_BITMAP(bpf);
91 #define BPF_PREALLOCATED_UNITS 4
93 #define BPF_PREALLOCATED_UNITS NBPF
99 * The default read buffer size is patchable.
101 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
102 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
103 &bpf_bufsize, 0, "");
104 int bpf_maxbufsize = BPF_MAXBUFSIZE;
105 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
106 &bpf_maxbufsize, 0, "");
109 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
111 static struct bpf_if *bpf_iflist;
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(const void *, 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 (*)(const void *, void *, size_t),
126 const struct timeval *);
127 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
128 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
129 static int bpf_setdlt(struct bpf_d *, u_int);
130 static void bpf_drvinit(void *unused);
131 static void bpf_filter_detach(struct knote *kn);
132 static int bpf_filter_read(struct knote *kn, long hint);
134 static d_open_t bpfopen;
135 static d_clone_t bpfclone;
136 static d_close_t bpfclose;
137 static d_read_t bpfread;
138 static d_write_t bpfwrite;
139 static d_ioctl_t bpfioctl;
140 static d_kqfilter_t bpfkqfilter;
142 #define CDEV_MAJOR 23
143 static struct dev_ops bpf_ops = {
144 { "bpf", CDEV_MAJOR, D_KQFILTER },
150 .d_kqfilter = bpfkqfilter
155 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
156 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
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 */
213 len = uio->uio_resid;
214 *datlen = len - hlen;
215 if ((unsigned)len > MCLBYTES)
218 m = m_getl(len, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
221 m->m_pkthdr.len = m->m_len = len;
222 m->m_pkthdr.rcvif = NULL;
225 if (m->m_len < hlen) {
230 error = uiomove(mtod(m, u_char *), len, uio);
234 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
241 * Make room for link header, and copy it to sockaddr.
244 bcopy(m->m_data, sockp->sa_data, hlen);
245 m->m_pkthdr.len -= hlen;
247 m->m_data += hlen; /* XXX */
256 * Attach file to the bpf interface, i.e. make d listen on bp.
257 * Must be called at splimp.
260 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
263 * Point d at bp, and add d to the interface's list of listeners.
264 * Finally, point the driver's bpf cookie at the interface so
265 * it will divert packets to bpf.
268 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
269 *bp->bif_driverp = bp;
271 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
275 * Detach a file from its interface.
278 bpf_detachd(struct bpf_d *d)
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",
321 * Open ethernet device. Returns ENXIO for illegal minor device number,
322 * EBUSY if file is open by another process.
326 bpfopen(struct dev_open_args *ap)
328 cdev_t dev = ap->a_head.a_dev;
331 if (ap->a_cred->cr_prison)
336 * Each minor can be opened by only one process. If the requested
337 * minor is in use, return EBUSY.
342 MALLOC(d, struct bpf_d *, sizeof *d, M_BPF, M_WAITOK | M_ZERO);
344 d->bd_bufsize = bpf_bufsize;
347 callout_init(&d->bd_callout);
352 bpfclone(struct dev_clone_args *ap)
356 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
357 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
363 * Close the descriptor by detaching it from its interface,
364 * deallocating its buffers, and marking it free.
368 bpfclose(struct dev_close_args *ap)
370 cdev_t dev = ap->a_head.a_dev;
371 struct bpf_d *d = dev->si_drv1;
373 funsetown(d->bd_sigio);
375 if (d->bd_state == BPF_WAITING)
376 callout_stop(&d->bd_callout);
377 d->bd_state = BPF_IDLE;
378 if (d->bd_bif != NULL)
383 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) {
384 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor);
392 * Rotate the packet buffers in descriptor d. Move the store buffer
393 * into the hold slot, and the free buffer into the store slot.
394 * Zero the length of the new store buffer.
396 #define ROTATE_BUFFERS(d) \
397 (d)->bd_hbuf = (d)->bd_sbuf; \
398 (d)->bd_hlen = (d)->bd_slen; \
399 (d)->bd_sbuf = (d)->bd_fbuf; \
403 * bpfread - read next chunk of packets from buffers
406 bpfread(struct dev_read_args *ap)
408 cdev_t dev = ap->a_head.a_dev;
409 struct bpf_d *d = dev->si_drv1;
414 * Restrict application to use a buffer the same size as
417 if (ap->a_uio->uio_resid != d->bd_bufsize)
421 if (d->bd_state == BPF_WAITING)
422 callout_stop(&d->bd_callout);
423 timed_out = (d->bd_state == BPF_TIMED_OUT);
424 d->bd_state = BPF_IDLE;
426 * If the hold buffer is empty, then do a timed sleep, which
427 * ends when the timeout expires or when enough packets
428 * have arrived to fill the store buffer.
430 while (d->bd_hbuf == NULL) {
431 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
432 && d->bd_slen != 0) {
434 * A packet(s) either arrived since the previous,
435 * We're in immediate mode, or are reading
436 * in non-blocking mode, and a packet(s)
437 * either arrived since the previous
438 * read or arrived while we were asleep.
439 * Rotate the buffers and return what's here.
446 * No data is available, check to see if the bpf device
447 * is still pointed at a real interface. If not, return
448 * ENXIO so that the userland process knows to rebind
449 * it before using it again.
451 if (d->bd_bif == NULL) {
456 if (ap->a_ioflag & IO_NDELAY) {
460 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
461 if (error == EINTR || error == ERESTART) {
465 if (error == EWOULDBLOCK) {
467 * On a timeout, return what's in the buffer,
468 * which may be nothing. If there is something
469 * in the store buffer, we can rotate the buffers.
473 * We filled up the buffer in between
474 * getting the timeout and arriving
475 * here, so we don't need to rotate.
479 if (d->bd_slen == 0) {
488 * At this point, we know we have something in the hold slot.
493 * Move data from hold buffer into user space.
494 * We know the entire buffer is transferred since
495 * we checked above that the read buffer is bpf_bufsize bytes.
497 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
500 d->bd_fbuf = d->bd_hbuf;
510 * If there are processes sleeping on this descriptor, wake them up.
513 bpf_wakeup(struct bpf_d *d)
515 if (d->bd_state == BPF_WAITING) {
516 callout_stop(&d->bd_callout);
517 d->bd_state = BPF_IDLE;
520 if (d->bd_async && d->bd_sig && d->bd_sigio)
521 pgsigio(d->bd_sigio, d->bd_sig, 0);
524 selwakeup(&d->bd_sel);
525 KNOTE(&d->bd_sel.si_note, 0);
528 d->bd_sel.si_pid = 0;
532 bpf_timed_out(void *arg)
534 struct bpf_d *d = (struct bpf_d *)arg;
537 if (d->bd_state == BPF_WAITING) {
538 d->bd_state = BPF_TIMED_OUT;
546 bpf_output_dispatch(struct netmsg *nmsg)
548 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)nmsg;
549 struct ifnet *ifp = bmsg->nm_ifp;
553 * The driver frees the mbuf.
555 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
556 lwkt_replymsg(&nmsg->nm_lmsg, error);
560 bpfwrite(struct dev_write_args *ap)
562 cdev_t dev = ap->a_head.a_dev;
563 struct bpf_d *d = dev->si_drv1;
569 struct netmsg_bpf_output bmsg;
571 if (d->bd_bif == NULL)
574 ifp = d->bd_bif->bif_ifp;
576 if (ap->a_uio->uio_resid == 0)
579 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
580 &dst, &datlen, d->bd_wfilter);
584 if (datlen > ifp->if_mtu) {
590 dst.sa_family = pseudo_AF_HDRCMPLT;
592 netmsg_init(&bmsg.nm_netmsg, NULL, &curthread->td_msgport,
593 MSGF_MPSAFE, bpf_output_dispatch);
598 return lwkt_domsg(cpu_portfn(0), &bmsg.nm_netmsg.nm_lmsg, 0);
602 * Reset a descriptor by flushing its packet buffer and clearing the
603 * receive and drop counts. Should be called at splimp.
606 bpf_resetd(struct bpf_d *d)
609 /* Free the hold buffer. */
610 d->bd_fbuf = d->bd_hbuf;
620 * FIONREAD Check for read packet available.
621 * SIOCGIFADDR Get interface address - convenient hook to driver.
622 * BIOCGBLEN Get buffer len [for read()].
623 * BIOCSETF Set ethernet read filter.
624 * BIOCSETWF Set ethernet write filter.
625 * BIOCFLUSH Flush read packet buffer.
626 * BIOCPROMISC Put interface into promiscuous mode.
627 * BIOCGDLT Get link layer type.
628 * BIOCGETIF Get interface name.
629 * BIOCSETIF Set interface.
630 * BIOCSRTIMEOUT Set read timeout.
631 * BIOCGRTIMEOUT Get read timeout.
632 * BIOCGSTATS Get packet stats.
633 * BIOCIMMEDIATE Set immediate mode.
634 * BIOCVERSION Get filter language version.
635 * BIOCGHDRCMPLT Get "header already complete" flag
636 * BIOCSHDRCMPLT Set "header already complete" flag
637 * BIOCGSEESENT Get "see packets sent" flag
638 * BIOCSSEESENT Set "see packets sent" flag
639 * BIOCLOCK Set "locked" flag
643 bpfioctl(struct dev_ioctl_args *ap)
645 cdev_t dev = ap->a_head.a_dev;
646 struct bpf_d *d = dev->si_drv1;
650 if (d->bd_state == BPF_WAITING)
651 callout_stop(&d->bd_callout);
652 d->bd_state = BPF_IDLE;
655 if (d->bd_locked == 1) {
683 * Check for read packet available.
695 *(int *)ap->a_data = n;
703 if (d->bd_bif == NULL) {
706 ifp = d->bd_bif->bif_ifp;
707 ifnet_serialize_all(ifp);
708 error = ifp->if_ioctl(ifp, ap->a_cmd,
709 ap->a_data, ap->a_cred);
710 ifnet_deserialize_all(ifp);
716 * Get buffer len [for read()].
719 *(u_int *)ap->a_data = d->bd_bufsize;
726 if (d->bd_bif != NULL) {
729 u_int size = *(u_int *)ap->a_data;
731 if (size > bpf_maxbufsize)
732 *(u_int *)ap->a_data = size = bpf_maxbufsize;
733 else if (size < BPF_MINBUFSIZE)
734 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
735 d->bd_bufsize = size;
740 * Set link layer read filter.
744 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
749 * Flush read packet buffer.
758 * Put interface into promiscuous mode.
761 if (d->bd_bif == NULL) {
763 * No interface attached yet.
769 if (d->bd_promisc == 0) {
770 error = ifpromisc(d->bd_bif->bif_ifp, 1);
778 * Get device parameters.
781 if (d->bd_bif == NULL)
784 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
788 * Get a list of supported data link types.
791 if (d->bd_bif == NULL) {
794 error = bpf_getdltlist(d,
795 (struct bpf_dltlist *)ap->a_data);
800 * Set data link type.
803 if (d->bd_bif == NULL)
806 error = bpf_setdlt(d, *(u_int *)ap->a_data);
810 * Get interface name.
813 if (d->bd_bif == NULL) {
816 struct ifnet *const ifp = d->bd_bif->bif_ifp;
817 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
819 strlcpy(ifr->ifr_name, ifp->if_xname,
820 sizeof ifr->ifr_name);
828 error = bpf_setif(d, (struct ifreq *)ap->a_data);
836 struct timeval *tv = (struct timeval *)ap->a_data;
839 * Subtract 1 tick from tvtohz() since this isn't
842 if ((error = itimerfix(tv)) == 0)
843 d->bd_rtout = tvtohz_low(tv);
852 struct timeval *tv = (struct timeval *)ap->a_data;
854 tv->tv_sec = d->bd_rtout / hz;
855 tv->tv_usec = (d->bd_rtout % hz) * ustick;
864 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
866 bs->bs_recv = d->bd_rcount;
867 bs->bs_drop = d->bd_dcount;
872 * Set immediate mode.
875 d->bd_immediate = *(u_int *)ap->a_data;
880 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
882 bv->bv_major = BPF_MAJOR_VERSION;
883 bv->bv_minor = BPF_MINOR_VERSION;
888 * Get "header already complete" flag
891 *(u_int *)ap->a_data = d->bd_hdrcmplt;
895 * Set "header already complete" flag
898 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
902 * Get "see sent packets" flag
905 *(u_int *)ap->a_data = d->bd_seesent;
909 * Set "see sent packets" flag
912 d->bd_seesent = *(u_int *)ap->a_data;
915 case FIOASYNC: /* Send signal on receive packets */
916 d->bd_async = *(int *)ap->a_data;
920 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
924 *(int *)ap->a_data = fgetown(d->bd_sigio);
927 /* This is deprecated, FIOSETOWN should be used instead. */
929 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
932 /* This is deprecated, FIOGETOWN should be used instead. */
934 *(int *)ap->a_data = -fgetown(d->bd_sigio);
937 case BIOCSRSIG: /* Set receive signal */
941 sig = *(u_int *)ap->a_data;
950 *(u_int *)ap->a_data = d->bd_sig;
960 * Set d's packet filter program to fp. If this file already has a filter,
961 * free it and replace it. Returns EINVAL for bogus requests.
964 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
966 struct bpf_insn *fcode, *old;
967 u_int wfilter, flen, size;
969 if (cmd == BIOCSETWF) {
976 if (fp->bf_insns == NULL) {
981 d->bd_wfilter = NULL;
983 d->bd_rfilter = NULL;
991 if (flen > BPF_MAXINSNS)
994 size = flen * sizeof *fp->bf_insns;
995 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
996 if (copyin(fp->bf_insns, fcode, size) == 0 &&
997 bpf_validate(fcode, (int)flen)) {
1000 d->bd_wfilter = fcode;
1002 d->bd_rfilter = fcode;
1010 kfree(fcode, M_BPF);
1015 * Detach a file from its current interface (if attached at all) and attach
1016 * to the interface indicated by the name stored in ifr.
1017 * Return an errno or 0.
1020 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1024 struct ifnet *theywant;
1026 theywant = ifunit(ifr->ifr_name);
1027 if (theywant == NULL)
1031 * Look through attached interfaces for the named one.
1033 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1034 struct ifnet *ifp = bp->bif_ifp;
1036 if (ifp == NULL || ifp != theywant)
1038 /* skip additional entry */
1039 if (bp->bif_driverp != &ifp->if_bpf)
1042 * We found the requested interface.
1043 * Allocate the packet buffers if we need to.
1044 * If we're already attached to requested interface,
1045 * just flush the buffer.
1047 if (d->bd_sbuf == NULL) {
1048 error = bpf_allocbufs(d);
1053 if (bp != d->bd_bif) {
1054 if (d->bd_bif != NULL) {
1056 * Detach if attached to something else.
1072 static struct filterops bpf_read_filtops =
1073 { 1, NULL, bpf_filter_detach, bpf_filter_read };
1076 bpfkqfilter(struct dev_kqfilter_args *ap)
1078 cdev_t dev = ap->a_head.a_dev;
1079 struct knote *kn = ap->a_kn;
1080 struct klist *klist;
1084 if (d->bd_bif == NULL) {
1090 switch (kn->kn_filter) {
1092 kn->kn_fop = &bpf_read_filtops;
1093 kn->kn_hook = (caddr_t)d;
1096 ap->a_result = EOPNOTSUPP;
1101 klist = &d->bd_sel.si_note;
1102 SLIST_INSERT_HEAD(klist, kn, kn_selnext);
1109 bpf_filter_detach(struct knote *kn)
1111 struct klist *klist;
1115 d = (struct bpf_d *)kn->kn_hook;
1116 klist = &d->bd_sel.si_note;
1117 SLIST_REMOVE(klist, kn, knote, kn_selnext);
1122 bpf_filter_read(struct knote *kn, long hint)
1128 d = (struct bpf_d *)kn->kn_hook;
1129 if (d->bd_hlen != 0 ||
1130 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1134 /* Start the read timeout if necessary. */
1135 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1136 callout_reset(&d->bd_callout, d->bd_rtout,
1138 d->bd_state = BPF_WAITING;
1148 * Process the packet pkt of length pktlen. The packet is parsed
1149 * by each listener's filter, and if accepted, stashed into the
1150 * corresponding buffer.
1153 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
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);
1189 * Copy data from an mbuf chain into a buffer. This code is derived
1190 * from m_copydata in sys/uipc_mbuf.c.
1193 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len)
1195 const struct mbuf *m;
1204 count = min(m->m_len, len);
1205 bcopy(mtod(m, void *), dst, count);
1213 * Process the packet in the mbuf chain m. The packet is parsed by each
1214 * listener's filter, and if accepted, stashed into the corresponding
1218 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1233 /* Don't compute pktlen, if no descriptor is attached. */
1234 if (SLIST_EMPTY(&bp->bif_dlist)) {
1239 pktlen = m_lengthm(m, NULL);
1241 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1242 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1245 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1251 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1260 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1264 KKASSERT(family != AF_UNSPEC);
1266 family4 = (u_int)family;
1267 bpf_ptap(bp, m, &family4, sizeof(family4));
1271 * Process the packet in the mbuf chain m with the header in m prepended.
1272 * The packet is parsed by each listener's filter, and if accepted,
1273 * stashed into the corresponding buffer.
1276 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1281 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1282 * Note that we cut corners here; we only setup what's
1283 * absolutely needed--this mbuf should never go anywhere else.
1286 mb.m_data = __DECONST(void *, data); /* LINTED */
1288 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1294 * Move the packet data from interface memory (pkt) into the
1295 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1296 * otherwise 0. "copy" is the routine called to do the actual data
1297 * transfer. bcopy is passed in to copy contiguous chunks, while
1298 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1299 * pkt is really an mbuf.
1302 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1303 void (*cpfn)(const void *, void *, size_t),
1304 const struct timeval *tv)
1308 int hdrlen = d->bd_bif->bif_hdrlen;
1310 * Figure out how many bytes to move. If the packet is
1311 * greater or equal to the snapshot length, transfer that
1312 * much. Otherwise, transfer the whole packet (unless
1313 * we hit the buffer size limit).
1315 totlen = hdrlen + min(snaplen, pktlen);
1316 if (totlen > d->bd_bufsize)
1317 totlen = d->bd_bufsize;
1320 * Round up the end of the previous packet to the next longword.
1322 curlen = BPF_WORDALIGN(d->bd_slen);
1323 if (curlen + totlen > d->bd_bufsize) {
1325 * This packet will overflow the storage buffer.
1326 * Rotate the buffers if we can, then wakeup any
1329 if (d->bd_fbuf == NULL) {
1331 * We haven't completed the previous read yet,
1332 * so drop the packet.
1340 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1342 * Immediate mode is set, or the read timeout has
1343 * already expired during a select call. A packet
1344 * arrived, so the reader should be woken up.
1350 * Append the bpf header.
1352 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1353 hp->bh_tstamp = *tv;
1354 hp->bh_datalen = pktlen;
1355 hp->bh_hdrlen = hdrlen;
1357 * Copy the packet data into the store buffer and update its length.
1359 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1360 d->bd_slen = curlen + totlen;
1364 * Initialize all nonzero fields of a descriptor.
1367 bpf_allocbufs(struct bpf_d *d)
1369 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1370 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1377 * Free buffers and packet filter program currently in use by a descriptor.
1381 bpf_freed(struct bpf_d *d)
1384 * We don't need to lock out interrupts since this descriptor has
1385 * been detached from its interface and it yet hasn't been marked
1388 if (d->bd_sbuf != NULL) {
1389 kfree(d->bd_sbuf, M_BPF);
1390 if (d->bd_hbuf != NULL)
1391 kfree(d->bd_hbuf, M_BPF);
1392 if (d->bd_fbuf != NULL)
1393 kfree(d->bd_fbuf, M_BPF);
1396 kfree(d->bd_rfilter, M_BPF);
1398 kfree(d->bd_wfilter, M_BPF);
1402 * Attach an interface to bpf. ifp is a pointer to the structure
1403 * defining the interface to be attached, dlt is the link layer type,
1404 * and hdrlen is the fixed size of the link header (variable length
1405 * headers are not yet supported).
1408 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1410 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1414 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1418 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1420 SLIST_INIT(&bp->bif_dlist);
1423 bp->bif_driverp = driverp;
1424 *bp->bif_driverp = NULL;
1426 bp->bif_next = bpf_iflist;
1430 * Compute the length of the bpf header. This is not necessarily
1431 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1432 * that the network layer header begins on a longword boundary (for
1433 * performance reasons and to alleviate alignment restrictions).
1435 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1438 if_printf(ifp, "bpf attached\n");
1442 * Detach bpf from an interface. This involves detaching each descriptor
1443 * associated with the interface, and leaving bd_bif NULL. Notify each
1444 * descriptor as it's detached so that any sleepers wake up and get
1448 bpfdetach(struct ifnet *ifp)
1450 struct bpf_if *bp, *bp_prev;
1455 /* Locate BPF interface information */
1457 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1458 if (ifp == bp->bif_ifp)
1463 /* Interface wasn't attached */
1464 if (bp->bif_ifp == NULL) {
1466 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1470 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1475 if (bp_prev != NULL)
1476 bp_prev->bif_next = bp->bif_next;
1478 bpf_iflist = bp->bif_next;
1486 * Get a list of available data link type of the interface.
1489 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1495 ifp = d->bd_bif->bif_ifp;
1498 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1499 if (bp->bif_ifp != ifp)
1501 if (bfl->bfl_list != NULL) {
1502 if (n >= bfl->bfl_len) {
1505 error = copyout(&bp->bif_dlt,
1506 bfl->bfl_list + n, sizeof(u_int));
1515 * Set the data link type of a BPF instance.
1518 bpf_setdlt(struct bpf_d *d, u_int dlt)
1520 int error, opromisc;
1524 if (d->bd_bif->bif_dlt == dlt)
1526 ifp = d->bd_bif->bif_ifp;
1527 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1528 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1532 opromisc = d->bd_promisc;
1538 error = ifpromisc(bp->bif_ifp, 1);
1540 if_printf(bp->bif_ifp,
1541 "bpf_setdlt: ifpromisc failed (%d)\n",
1549 return(bp == NULL ? EINVAL : 0);
1553 bpf_drvinit(void *unused)
1557 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1558 bpfclone, 0, 0, 0600, "bpf");
1559 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1560 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1561 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1566 bpf_drvuninit(void *unused)
1568 devfs_clone_handler_del("bpf");
1569 dev_ops_remove_all(&bpf_ops);
1570 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1573 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL)
1574 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1578 * NOP stubs to allow bpf-using drivers to load and function.
1580 * A 'better' implementation would allow the core bpf functionality
1581 * to be loaded at runtime.
1585 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1590 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1595 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1600 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1605 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1610 bpfdetach(struct ifnet *ifp)
1615 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1617 return -1; /* "no filter" behaviour */