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 * 4. 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 8.4 (Berkeley) 1/9/95
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
41 #include "opt_compat.h"
42 #include "opt_netgraph.h"
44 #include <sys/types.h>
45 #include <sys/param.h>
47 #include <sys/rwlock.h>
48 #include <sys/systm.h>
50 #include <sys/fcntl.h>
52 #include <sys/malloc.h>
57 #include <sys/signalvar.h>
58 #include <sys/filio.h>
59 #include <sys/sockio.h>
60 #include <sys/ttycom.h>
63 #include <sys/event.h>
68 #include <sys/socket.h>
73 #include <net/bpf_buffer.h>
75 #include <net/bpf_jitter.h>
77 #include <net/bpf_zerocopy.h>
78 #include <net/bpfdesc.h>
81 #include <netinet/in.h>
82 #include <netinet/if_ether.h>
83 #include <sys/kernel.h>
84 #include <sys/sysctl.h>
86 #include <net80211/ieee80211_freebsd.h>
88 #include <security/mac/mac_framework.h>
90 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
92 #if defined(DEV_BPF) || defined(NETGRAPH_BPF)
94 #define PRINET 26 /* interruptible */
96 #define SIZEOF_BPF_HDR(type) \
97 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen))
99 #ifdef COMPAT_FREEBSD32
100 #include <sys/mount.h>
101 #include <compat/freebsd32/freebsd32.h>
102 #define BPF_ALIGNMENT32 sizeof(int32_t)
103 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
107 * 32-bit version of structure prepended to each packet. We use this header
108 * instead of the standard one for 32-bit streams. We mark the a stream as
109 * 32-bit the first time we see a 32-bit compat ioctl request.
112 struct timeval32 bh_tstamp; /* time stamp */
113 uint32_t bh_caplen; /* length of captured portion */
114 uint32_t bh_datalen; /* original length of packet */
115 uint16_t bh_hdrlen; /* length of bpf header (this struct
116 plus alignment padding) */
120 struct bpf_program32 {
125 struct bpf_dltlist32 {
130 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32)
131 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32)
132 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32)
133 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32)
134 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32)
135 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32)
139 * bpf_iflist is a list of BPF interface structures, each corresponding to a
140 * specific DLT. The same network interface might have several BPF interface
141 * structures registered by different layers in the stack (i.e., 802.11
142 * frames, ethernet frames, etc).
144 static LIST_HEAD(, bpf_if) bpf_iflist;
145 static struct mtx bpf_mtx; /* bpf global lock */
146 static int bpf_bpfd_cnt;
148 static void bpf_attachd(struct bpf_d *, struct bpf_if *);
149 static void bpf_detachd(struct bpf_d *);
150 static void bpf_detachd_locked(struct bpf_d *);
151 static void bpf_freed(struct bpf_d *);
152 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **,
153 struct sockaddr *, int *, struct bpf_insn *);
154 static int bpf_setif(struct bpf_d *, struct ifreq *);
155 static void bpf_timed_out(void *);
157 bpf_wakeup(struct bpf_d *);
158 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
159 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int),
161 static void reset_d(struct bpf_d *);
162 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
163 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
164 static int bpf_setdlt(struct bpf_d *, u_int);
165 static void filt_bpfdetach(struct knote *);
166 static int filt_bpfread(struct knote *, long);
167 static void bpf_drvinit(void *);
168 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS);
170 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl");
171 int bpf_maxinsns = BPF_MAXINSNS;
172 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW,
173 &bpf_maxinsns, 0, "Maximum bpf program instructions");
174 static int bpf_zerocopy_enable = 0;
175 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW,
176 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions");
177 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW,
178 bpf_stats_sysctl, "bpf statistics portal");
180 static VNET_DEFINE(int, bpf_optimize_writers) = 0;
181 #define V_bpf_optimize_writers VNET(bpf_optimize_writers)
182 SYSCTL_VNET_INT(_net_bpf, OID_AUTO, optimize_writers,
183 CTLFLAG_RW, &VNET_NAME(bpf_optimize_writers), 0,
184 "Do not send packets until BPF program is set");
186 static d_open_t bpfopen;
187 static d_read_t bpfread;
188 static d_write_t bpfwrite;
189 static d_ioctl_t bpfioctl;
190 static d_poll_t bpfpoll;
191 static d_kqfilter_t bpfkqfilter;
193 static struct cdevsw bpf_cdevsw = {
194 .d_version = D_VERSION,
201 .d_kqfilter = bpfkqfilter,
204 static struct filterops bpfread_filtops = {
206 .f_detach = filt_bpfdetach,
207 .f_event = filt_bpfread,
210 eventhandler_tag bpf_ifdetach_cookie = NULL;
213 * LOCKING MODEL USED BY BPF:
215 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal,
216 * some global counters and every bpf_if reference.
217 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters.
218 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields
219 * used by bpf_mtap code.
223 * Global lock, interface lock, descriptor lock
225 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2]
226 * working model. In many places (like bpf_detachd) we start with BPF descriptor
227 * (and we need to at least rlock it to get reliable interface pointer). This
228 * gives us potential LOR. As a result, we use global lock to protect from bpf_if
229 * change in every such place.
231 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and
232 * 3) descriptor main wlock.
233 * Reading bd_bif can be protected by any of these locks, typically global lock.
235 * Changing read/write BPF filter is protected by the same three locks,
236 * the same applies for reading.
238 * Sleeping in global lock is not allowed due to bpfdetach() using it.
242 * Wrapper functions for various buffering methods. If the set of buffer
243 * modes expands, we will probably want to introduce a switch data structure
244 * similar to protosw, et.
247 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
253 switch (d->bd_bufmode) {
254 case BPF_BUFMODE_BUFFER:
255 return (bpf_buffer_append_bytes(d, buf, offset, src, len));
257 case BPF_BUFMODE_ZBUF:
259 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len));
262 panic("bpf_buf_append_bytes");
267 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
273 switch (d->bd_bufmode) {
274 case BPF_BUFMODE_BUFFER:
275 return (bpf_buffer_append_mbuf(d, buf, offset, src, len));
277 case BPF_BUFMODE_ZBUF:
279 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len));
282 panic("bpf_buf_append_mbuf");
287 * This function gets called when the free buffer is re-assigned.
290 bpf_buf_reclaimed(struct bpf_d *d)
295 switch (d->bd_bufmode) {
296 case BPF_BUFMODE_BUFFER:
299 case BPF_BUFMODE_ZBUF:
300 bpf_zerocopy_buf_reclaimed(d);
304 panic("bpf_buf_reclaimed");
309 * If the buffer mechanism has a way to decide that a held buffer can be made
310 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is
311 * returned if the buffer can be discarded, (0) is returned if it cannot.
314 bpf_canfreebuf(struct bpf_d *d)
319 switch (d->bd_bufmode) {
320 case BPF_BUFMODE_ZBUF:
321 return (bpf_zerocopy_canfreebuf(d));
327 * Allow the buffer model to indicate that the current store buffer is
328 * immutable, regardless of the appearance of space. Return (1) if the
329 * buffer is writable, and (0) if not.
332 bpf_canwritebuf(struct bpf_d *d)
336 switch (d->bd_bufmode) {
337 case BPF_BUFMODE_ZBUF:
338 return (bpf_zerocopy_canwritebuf(d));
344 * Notify buffer model that an attempt to write to the store buffer has
345 * resulted in a dropped packet, in which case the buffer may be considered
349 bpf_buffull(struct bpf_d *d)
354 switch (d->bd_bufmode) {
355 case BPF_BUFMODE_ZBUF:
356 bpf_zerocopy_buffull(d);
362 * Notify the buffer model that a buffer has moved into the hold position.
365 bpf_bufheld(struct bpf_d *d)
370 switch (d->bd_bufmode) {
371 case BPF_BUFMODE_ZBUF:
372 bpf_zerocopy_bufheld(d);
378 bpf_free(struct bpf_d *d)
381 switch (d->bd_bufmode) {
382 case BPF_BUFMODE_BUFFER:
383 return (bpf_buffer_free(d));
385 case BPF_BUFMODE_ZBUF:
386 return (bpf_zerocopy_free(d));
389 panic("bpf_buf_free");
394 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
397 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
399 return (bpf_buffer_uiomove(d, buf, len, uio));
403 bpf_ioctl_sblen(struct bpf_d *d, u_int *i)
406 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
408 return (bpf_buffer_ioctl_sblen(d, i));
412 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i)
415 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
417 return (bpf_zerocopy_ioctl_getzmax(td, d, i));
421 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
424 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
426 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz));
430 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
433 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
435 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz));
439 * General BPF functions.
442 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp,
443 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter)
445 const struct ieee80211_bpf_params *p;
446 struct ether_header *eh;
454 * Build a sockaddr based on the data link layer type.
455 * We do this at this level because the ethernet header
456 * is copied directly into the data field of the sockaddr.
457 * In the case of SLIP, there is no header and the packet
458 * is forwarded as is.
459 * Also, we are careful to leave room at the front of the mbuf
460 * for the link level header.
465 sockp->sa_family = AF_INET;
470 sockp->sa_family = AF_UNSPEC;
471 /* XXX Would MAXLINKHDR be better? */
472 hlen = ETHER_HDR_LEN;
476 sockp->sa_family = AF_IMPLINK;
481 sockp->sa_family = AF_UNSPEC;
487 * null interface types require a 4 byte pseudo header which
488 * corresponds to the address family of the packet.
490 sockp->sa_family = AF_UNSPEC;
494 case DLT_ATM_RFC1483:
496 * en atm driver requires 4-byte atm pseudo header.
497 * though it isn't standard, vpi:vci needs to be
500 sockp->sa_family = AF_UNSPEC;
501 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
505 sockp->sa_family = AF_UNSPEC;
506 hlen = 4; /* This should match PPP_HDRLEN */
509 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
510 sockp->sa_family = AF_IEEE80211;
514 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
515 sockp->sa_family = AF_IEEE80211;
516 sockp->sa_len = 12; /* XXX != 0 */
517 hlen = sizeof(struct ieee80211_bpf_params);
524 len = uio->uio_resid;
526 if (len - hlen > ifp->if_mtu)
529 if ((unsigned)len > MJUM16BYTES)
533 MGETHDR(m, M_WAIT, MT_DATA);
534 else if (len <= MCLBYTES)
535 m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR);
537 m = m_getjcl(M_WAIT, MT_DATA, M_PKTHDR,
538 #if (MJUMPAGESIZE > MCLBYTES)
539 len <= MJUMPAGESIZE ? MJUMPAGESIZE :
541 (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES));
542 m->m_pkthdr.len = m->m_len = len;
543 m->m_pkthdr.rcvif = NULL;
546 if (m->m_len < hlen) {
551 error = uiomove(mtod(m, u_char *), len, uio);
555 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
561 /* Check for multicast destination */
564 eh = mtod(m, struct ether_header *);
565 if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
566 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
567 ETHER_ADDR_LEN) == 0)
568 m->m_flags |= M_BCAST;
570 m->m_flags |= M_MCAST;
576 * Make room for link header, and copy it to sockaddr
579 if (sockp->sa_family == AF_IEEE80211) {
581 * Collect true length from the parameter header
582 * NB: sockp is known to be zero'd so if we do a
583 * short copy unspecified parameters will be
585 * NB: packet may not be aligned after stripping
589 p = mtod(m, const struct ieee80211_bpf_params *);
591 if (hlen > sizeof(sockp->sa_data)) {
596 bcopy(m->m_data, sockp->sa_data, hlen);
607 * Attach file to the bpf interface, i.e. make d listen on bp.
610 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
617 * Save sysctl value to protect from sysctl change
620 op_w = V_bpf_optimize_writers || d->bd_writer;
622 if (d->bd_bif != NULL)
623 bpf_detachd_locked(d);
625 * Point d at bp, and add d to the interface's list.
626 * Since there are many applicaiotns using BPF for
627 * sending raw packets only (dhcpd, cdpd are good examples)
628 * we can delay adding d to the list of active listeners until
629 * some filter is configured.
638 /* Add to writers-only list */
639 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next);
641 * We decrement bd_writer on every filter set operation.
642 * First BIOCSETF is done by pcap_open_live() to set up
643 * snap length. After that appliation usually sets its own filter
647 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
654 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list",
655 __func__, d->bd_pid, d->bd_writer ? "writer" : "active");
658 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
662 * Check if we need to upgrade our descriptor @d from write-only mode.
665 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen)
667 int is_snap, need_upgrade;
670 * Check if we've already upgraded or new filter is empty.
672 if (d->bd_writer == 0 || fcode == NULL)
678 * Check if cmd looks like snaplen setting from
679 * pcap_bpf.c:pcap_open_live().
680 * Note we're not checking .k value here:
681 * while pcap_open_live() definitely sets to to non-zero value,
682 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g.
683 * do not consider upgrading immediately
685 if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K))
692 * We're setting first filter and it doesn't look like
693 * setting snaplen. We're probably using bpf directly.
694 * Upgrade immediately.
699 * Do not require upgrade by first BIOCSETF
700 * (used to set snaplen) by pcap_open_live().
703 if (--d->bd_writer == 0) {
705 * First snaplen filter has already
706 * been set. This is probably catch-all
714 "%s: filter function set by pid %d, "
715 "bd_writer counter %d, snap %d upgrade %d",
716 __func__, d->bd_pid, d->bd_writer,
717 is_snap, need_upgrade);
719 return (need_upgrade);
723 * Add d to the list of active bp filters.
724 * Reuqires bpf_attachd() to be called before
727 bpf_upgraded(struct bpf_d *d)
736 * Filter can be set several times without specifying interface.
737 * Mark d as reader and exit.
749 /* Remove from writers-only list */
750 LIST_REMOVE(d, bd_next);
751 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
752 /* Mark d as reader */
758 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid);
760 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
764 * Detach a file from its interface.
767 bpf_detachd(struct bpf_d *d)
770 bpf_detachd_locked(d);
775 bpf_detachd_locked(struct bpf_d *d)
781 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid);
785 /* Check if descriptor is attached */
786 if ((bp = d->bd_bif) == NULL)
792 /* Save bd_writer value */
793 error = d->bd_writer;
796 * Remove d from the interface's descriptor list.
798 LIST_REMOVE(d, bd_next);
807 /* Call event handler iff d is attached */
809 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
812 * Check if this descriptor had requested promiscuous mode.
813 * If so, turn it off.
817 CURVNET_SET(ifp->if_vnet);
818 error = ifpromisc(ifp, 0);
820 if (error != 0 && error != ENXIO) {
822 * ENXIO can happen if a pccard is unplugged
823 * Something is really wrong if we were able to put
824 * the driver into promiscuous mode, but can't
827 if_printf(bp->bif_ifp,
828 "bpf_detach: ifpromisc failed (%d)\n", error);
834 * Close the descriptor by detaching it from its interface,
835 * deallocating its buffers, and marking it free.
840 struct bpf_d *d = data;
843 if (d->bd_state == BPF_WAITING)
844 callout_stop(&d->bd_callout);
845 d->bd_state = BPF_IDLE;
847 funsetown(&d->bd_sigio);
850 mac_bpfdesc_destroy(d);
852 seldrain(&d->bd_sel);
853 knlist_destroy(&d->bd_sel.si_note);
854 callout_drain(&d->bd_callout);
860 * Open ethernet device. Returns ENXIO for illegal minor device number,
861 * EBUSY if file is open by another process.
865 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td)
870 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
871 error = devfs_set_cdevpriv(d, bpf_dtor);
878 * For historical reasons, perform a one-time initialization call to
879 * the buffer routines, even though we're not yet committed to a
880 * particular buffer method.
883 if ((flags & FREAD) == 0)
885 d->bd_hbuf_in_use = 0;
886 d->bd_bufmode = BPF_BUFMODE_BUFFER;
888 d->bd_direction = BPF_D_INOUT;
889 BPF_PID_REFRESH(d, td);
892 mac_bpfdesc_create(td->td_ucred, d);
894 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF);
895 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0);
896 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock);
898 /* Allocate default buffers */
899 size = d->bd_bufsize;
900 bpf_buffer_ioctl_sblen(d, &size);
906 * bpfread - read next chunk of packets from buffers
909 bpfread(struct cdev *dev, struct uio *uio, int ioflag)
916 error = devfs_get_cdevpriv((void **)&d);
921 * Restrict application to use a buffer the same size as
924 if (uio->uio_resid != d->bd_bufsize)
927 non_block = ((ioflag & O_NONBLOCK) != 0);
930 BPF_PID_REFRESH_CUR(d);
931 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
935 if (d->bd_state == BPF_WAITING)
936 callout_stop(&d->bd_callout);
937 timed_out = (d->bd_state == BPF_TIMED_OUT);
938 d->bd_state = BPF_IDLE;
939 while (d->bd_hbuf_in_use) {
940 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
941 PRINET|PCATCH, "bd_hbuf", 0);
948 * If the hold buffer is empty, then do a timed sleep, which
949 * ends when the timeout expires or when enough packets
950 * have arrived to fill the store buffer.
952 while (d->bd_hbuf == NULL) {
953 if (d->bd_slen != 0) {
955 * A packet(s) either arrived since the previous
956 * read or arrived while we were asleep.
958 if (d->bd_immediate || non_block || timed_out) {
960 * Rotate the buffers and return what's here
961 * if we are in immediate mode, non-blocking
962 * flag is set, or this descriptor timed out.
970 * No data is available, check to see if the bpf device
971 * is still pointed at a real interface. If not, return
972 * ENXIO so that the userland process knows to rebind
973 * it before using it again.
975 if (d->bd_bif == NULL) {
982 return (EWOULDBLOCK);
984 error = msleep(d, &d->bd_lock, PRINET|PCATCH,
986 if (error == EINTR || error == ERESTART) {
990 if (error == EWOULDBLOCK) {
992 * On a timeout, return what's in the buffer,
993 * which may be nothing. If there is something
994 * in the store buffer, we can rotate the buffers.
998 * We filled up the buffer in between
999 * getting the timeout and arriving
1000 * here, so we don't need to rotate.
1004 if (d->bd_slen == 0) {
1013 * At this point, we know we have something in the hold slot.
1015 d->bd_hbuf_in_use = 1;
1019 * Move data from hold buffer into user space.
1020 * We know the entire buffer is transferred since
1021 * we checked above that the read buffer is bpf_bufsize bytes.
1023 * We do not have to worry about simultaneous reads because
1024 * we waited for sole access to the hold buffer above.
1026 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio);
1029 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf"));
1030 d->bd_fbuf = d->bd_hbuf;
1033 bpf_buf_reclaimed(d);
1034 d->bd_hbuf_in_use = 0;
1035 wakeup(&d->bd_hbuf_in_use);
1042 * If there are processes sleeping on this descriptor, wake them up.
1044 static __inline void
1045 bpf_wakeup(struct bpf_d *d)
1048 BPFD_LOCK_ASSERT(d);
1049 if (d->bd_state == BPF_WAITING) {
1050 callout_stop(&d->bd_callout);
1051 d->bd_state = BPF_IDLE;
1054 if (d->bd_async && d->bd_sig && d->bd_sigio)
1055 pgsigio(&d->bd_sigio, d->bd_sig, 0);
1057 selwakeuppri(&d->bd_sel, PRINET);
1058 KNOTE_LOCKED(&d->bd_sel.si_note, 0);
1062 bpf_timed_out(void *arg)
1064 struct bpf_d *d = (struct bpf_d *)arg;
1066 BPFD_LOCK_ASSERT(d);
1068 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout))
1070 if (d->bd_state == BPF_WAITING) {
1071 d->bd_state = BPF_TIMED_OUT;
1072 if (d->bd_slen != 0)
1078 bpf_ready(struct bpf_d *d)
1081 BPFD_LOCK_ASSERT(d);
1083 if (!bpf_canfreebuf(d) && d->bd_hlen != 0)
1085 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1092 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag)
1096 struct mbuf *m, *mc;
1097 struct sockaddr dst;
1100 error = devfs_get_cdevpriv((void **)&d);
1104 BPF_PID_REFRESH_CUR(d);
1106 /* XXX: locking required */
1107 if (d->bd_bif == NULL) {
1112 ifp = d->bd_bif->bif_ifp;
1114 if ((ifp->if_flags & IFF_UP) == 0) {
1119 if (uio->uio_resid == 0) {
1124 bzero(&dst, sizeof(dst));
1127 /* XXX: bpf_movein() can sleep */
1128 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp,
1129 &m, &dst, &hlen, d->bd_wfilter);
1136 dst.sa_family = pseudo_AF_HDRCMPLT;
1138 if (d->bd_feedback) {
1139 mc = m_dup(m, M_DONTWAIT);
1141 mc->m_pkthdr.rcvif = ifp;
1142 /* Set M_PROMISC for outgoing packets to be discarded. */
1143 if (d->bd_direction == BPF_D_INOUT)
1144 m->m_flags |= M_PROMISC;
1148 m->m_pkthdr.len -= hlen;
1150 m->m_data += hlen; /* XXX */
1152 CURVNET_SET(ifp->if_vnet);
1155 mac_bpfdesc_create_mbuf(d, m);
1157 mac_bpfdesc_create_mbuf(d, mc);
1161 error = (*ifp->if_output)(ifp, m, &dst, NULL);
1167 (*ifp->if_input)(ifp, mc);
1177 * Reset a descriptor by flushing its packet buffer and clearing the receive
1178 * and drop counts. This is doable for kernel-only buffers, but with
1179 * zero-copy buffers, we can't write to (or rotate) buffers that are
1180 * currently owned by userspace. It would be nice if we could encapsulate
1181 * this logic in the buffer code rather than here.
1184 reset_d(struct bpf_d *d)
1187 BPFD_LOCK_ASSERT(d);
1189 while (d->bd_hbuf_in_use)
1190 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET,
1192 if ((d->bd_hbuf != NULL) &&
1193 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) {
1194 /* Free the hold buffer. */
1195 d->bd_fbuf = d->bd_hbuf;
1198 bpf_buf_reclaimed(d);
1200 if (bpf_canwritebuf(d))
1212 * FIONREAD Check for read packet available.
1213 * SIOCGIFADDR Get interface address - convenient hook to driver.
1214 * BIOCGBLEN Get buffer len [for read()].
1215 * BIOCSETF Set read filter.
1216 * BIOCSETFNR Set read filter without resetting descriptor.
1217 * BIOCSETWF Set write filter.
1218 * BIOCFLUSH Flush read packet buffer.
1219 * BIOCPROMISC Put interface into promiscuous mode.
1220 * BIOCGDLT Get link layer type.
1221 * BIOCGETIF Get interface name.
1222 * BIOCSETIF Set interface.
1223 * BIOCSRTIMEOUT Set read timeout.
1224 * BIOCGRTIMEOUT Get read timeout.
1225 * BIOCGSTATS Get packet stats.
1226 * BIOCIMMEDIATE Set immediate mode.
1227 * BIOCVERSION Get filter language version.
1228 * BIOCGHDRCMPLT Get "header already complete" flag
1229 * BIOCSHDRCMPLT Set "header already complete" flag
1230 * BIOCGDIRECTION Get packet direction flag
1231 * BIOCSDIRECTION Set packet direction flag
1232 * BIOCGTSTAMP Get time stamp format and resolution.
1233 * BIOCSTSTAMP Set time stamp format and resolution.
1234 * BIOCLOCK Set "locked" flag
1235 * BIOCFEEDBACK Set packet feedback mode.
1236 * BIOCSETZBUF Set current zero-copy buffer locations.
1237 * BIOCGETZMAX Get maximum zero-copy buffer size.
1238 * BIOCROTZBUF Force rotation of zero-copy buffer
1239 * BIOCSETBUFMODE Set buffer mode.
1240 * BIOCGETBUFMODE Get current buffer mode.
1244 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
1250 error = devfs_get_cdevpriv((void **)&d);
1255 * Refresh PID associated with this descriptor.
1258 BPF_PID_REFRESH(d, td);
1259 if (d->bd_state == BPF_WAITING)
1260 callout_stop(&d->bd_callout);
1261 d->bd_state = BPF_IDLE;
1264 if (d->bd_locked == 1) {
1270 #ifdef COMPAT_FREEBSD32
1271 case BIOCGDLTLIST32:
1275 #ifdef COMPAT_FREEBSD32
1276 case BIOCGRTIMEOUT32:
1287 #ifdef COMPAT_FREEBSD32
1288 case BIOCSRTIMEOUT32:
1298 #ifdef COMPAT_FREEBSD32
1300 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so
1301 * that it will get 32-bit packet headers.
1307 case BIOCGDLTLIST32:
1308 case BIOCGRTIMEOUT32:
1309 case BIOCSRTIMEOUT32:
1316 CURVNET_SET(TD_TO_VNET(td));
1324 * Check for read packet available.
1332 while (d->bd_hbuf_in_use)
1333 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
1334 PRINET, "bd_hbuf", 0);
1347 if (d->bd_bif == NULL)
1350 ifp = d->bd_bif->bif_ifp;
1351 error = (*ifp->if_ioctl)(ifp, cmd, addr);
1357 * Get buffer len [for read()].
1361 *(u_int *)addr = d->bd_bufsize;
1366 * Set buffer length.
1369 error = bpf_ioctl_sblen(d, (u_int *)addr);
1373 * Set link layer read filter.
1378 #ifdef COMPAT_FREEBSD32
1383 error = bpf_setf(d, (struct bpf_program *)addr, cmd);
1387 * Flush read packet buffer.
1396 * Put interface into promiscuous mode.
1399 if (d->bd_bif == NULL) {
1401 * No interface attached yet.
1406 if (d->bd_promisc == 0) {
1407 error = ifpromisc(d->bd_bif->bif_ifp, 1);
1414 * Get current data link type.
1418 if (d->bd_bif == NULL)
1421 *(u_int *)addr = d->bd_bif->bif_dlt;
1426 * Get a list of supported data link types.
1428 #ifdef COMPAT_FREEBSD32
1429 case BIOCGDLTLIST32:
1431 struct bpf_dltlist32 *list32;
1432 struct bpf_dltlist dltlist;
1434 list32 = (struct bpf_dltlist32 *)addr;
1435 dltlist.bfl_len = list32->bfl_len;
1436 dltlist.bfl_list = PTRIN(list32->bfl_list);
1438 if (d->bd_bif == NULL)
1441 error = bpf_getdltlist(d, &dltlist);
1443 list32->bfl_len = dltlist.bfl_len;
1452 if (d->bd_bif == NULL)
1455 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
1460 * Set data link type.
1464 if (d->bd_bif == NULL)
1467 error = bpf_setdlt(d, *(u_int *)addr);
1472 * Get interface name.
1476 if (d->bd_bif == NULL)
1479 struct ifnet *const ifp = d->bd_bif->bif_ifp;
1480 struct ifreq *const ifr = (struct ifreq *)addr;
1482 strlcpy(ifr->ifr_name, ifp->if_xname,
1483 sizeof(ifr->ifr_name));
1493 error = bpf_setif(d, (struct ifreq *)addr);
1501 #ifdef COMPAT_FREEBSD32
1502 case BIOCSRTIMEOUT32:
1505 struct timeval *tv = (struct timeval *)addr;
1506 #ifdef COMPAT_FREEBSD32
1507 struct timeval32 *tv32;
1508 struct timeval tv64;
1510 if (cmd == BIOCSRTIMEOUT32) {
1511 tv32 = (struct timeval32 *)addr;
1513 tv->tv_sec = tv32->tv_sec;
1514 tv->tv_usec = tv32->tv_usec;
1517 tv = (struct timeval *)addr;
1520 * Subtract 1 tick from tvtohz() since this isn't
1523 if ((error = itimerfix(tv)) == 0)
1524 d->bd_rtout = tvtohz(tv) - 1;
1532 #ifdef COMPAT_FREEBSD32
1533 case BIOCGRTIMEOUT32:
1537 #ifdef COMPAT_FREEBSD32
1538 struct timeval32 *tv32;
1539 struct timeval tv64;
1541 if (cmd == BIOCGRTIMEOUT32)
1545 tv = (struct timeval *)addr;
1547 tv->tv_sec = d->bd_rtout / hz;
1548 tv->tv_usec = (d->bd_rtout % hz) * tick;
1549 #ifdef COMPAT_FREEBSD32
1550 if (cmd == BIOCGRTIMEOUT32) {
1551 tv32 = (struct timeval32 *)addr;
1552 tv32->tv_sec = tv->tv_sec;
1553 tv32->tv_usec = tv->tv_usec;
1565 struct bpf_stat *bs = (struct bpf_stat *)addr;
1567 /* XXXCSJP overflow */
1568 bs->bs_recv = d->bd_rcount;
1569 bs->bs_drop = d->bd_dcount;
1574 * Set immediate mode.
1578 d->bd_immediate = *(u_int *)addr;
1584 struct bpf_version *bv = (struct bpf_version *)addr;
1586 bv->bv_major = BPF_MAJOR_VERSION;
1587 bv->bv_minor = BPF_MINOR_VERSION;
1592 * Get "header already complete" flag
1596 *(u_int *)addr = d->bd_hdrcmplt;
1601 * Set "header already complete" flag
1605 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
1610 * Get packet direction flag
1612 case BIOCGDIRECTION:
1614 *(u_int *)addr = d->bd_direction;
1619 * Set packet direction flag
1621 case BIOCSDIRECTION:
1625 direction = *(u_int *)addr;
1626 switch (direction) {
1631 d->bd_direction = direction;
1641 * Get packet timestamp format and resolution.
1645 *(u_int *)addr = d->bd_tstamp;
1650 * Set packet timestamp format and resolution.
1656 func = *(u_int *)addr;
1657 if (BPF_T_VALID(func))
1658 d->bd_tstamp = func;
1666 d->bd_feedback = *(u_int *)addr;
1676 case FIONBIO: /* Non-blocking I/O */
1679 case FIOASYNC: /* Send signal on receive packets */
1681 d->bd_async = *(int *)addr;
1687 * XXX: Add some sort of locking here?
1688 * fsetown() can sleep.
1690 error = fsetown(*(int *)addr, &d->bd_sigio);
1695 *(int *)addr = fgetown(&d->bd_sigio);
1699 /* This is deprecated, FIOSETOWN should be used instead. */
1701 error = fsetown(-(*(int *)addr), &d->bd_sigio);
1704 /* This is deprecated, FIOGETOWN should be used instead. */
1706 *(int *)addr = -fgetown(&d->bd_sigio);
1709 case BIOCSRSIG: /* Set receive signal */
1713 sig = *(u_int *)addr;
1726 *(u_int *)addr = d->bd_sig;
1730 case BIOCGETBUFMODE:
1732 *(u_int *)addr = d->bd_bufmode;
1736 case BIOCSETBUFMODE:
1738 * Allow the buffering mode to be changed as long as we
1739 * haven't yet committed to a particular mode. Our
1740 * definition of commitment, for now, is whether or not a
1741 * buffer has been allocated or an interface attached, since
1742 * that's the point where things get tricky.
1744 switch (*(u_int *)addr) {
1745 case BPF_BUFMODE_BUFFER:
1748 case BPF_BUFMODE_ZBUF:
1749 if (bpf_zerocopy_enable)
1759 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL ||
1760 d->bd_fbuf != NULL || d->bd_bif != NULL) {
1765 d->bd_bufmode = *(u_int *)addr;
1770 error = bpf_ioctl_getzmax(td, d, (size_t *)addr);
1774 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr);
1778 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr);
1786 * Set d's packet filter program to fp. If this file already has a filter,
1787 * free it and replace it. Returns EINVAL for bogus requests.
1789 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls
1790 * since reading d->bd_bif can't be protected by d or interface lock due to
1793 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses
1794 * interface read lock to read all filers.
1798 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1800 #ifdef COMPAT_FREEBSD32
1801 struct bpf_program fp_swab;
1802 struct bpf_program32 *fp32;
1804 struct bpf_insn *fcode, *old;
1806 bpf_jit_filter *jfunc, *ofunc;
1812 #ifdef COMPAT_FREEBSD32
1817 fp32 = (struct bpf_program32 *)fp;
1818 fp_swab.bf_len = fp32->bf_len;
1819 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns;
1835 jfunc = ofunc = NULL;
1840 * Check new filter validness before acquiring any locks.
1841 * Allocate memory for new filter, if needed.
1844 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0))
1846 size = flen * sizeof(*fp->bf_insns);
1848 /* We're setting up new filter. Copy and check actual data. */
1849 fcode = malloc(size, M_BPF, M_WAITOK);
1850 if (copyin(fp->bf_insns, fcode, size) != 0 ||
1851 !bpf_validate(fcode, flen)) {
1856 /* Filter is copied inside fcode and is perfectly valid. */
1857 jfunc = bpf_jitter(fcode, flen);
1864 * Set up new filter.
1865 * Protect filter change by interface lock.
1866 * Additionally, we are protected by global lock here.
1868 if (d->bd_bif != NULL)
1869 BPFIF_WLOCK(d->bd_bif);
1871 if (cmd == BIOCSETWF) {
1872 old = d->bd_wfilter;
1873 d->bd_wfilter = fcode;
1875 old = d->bd_rfilter;
1876 d->bd_rfilter = fcode;
1878 ofunc = d->bd_bfilter;
1879 d->bd_bfilter = jfunc;
1881 if (cmd == BIOCSETF)
1884 need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen);
1887 if (d->bd_bif != NULL)
1888 BPFIF_WUNLOCK(d->bd_bif);
1893 bpf_destroy_jit_filter(ofunc);
1896 /* Move d to active readers list. */
1897 if (need_upgrade != 0)
1905 * Detach a file from its current interface (if attached at all) and attach
1906 * to the interface indicated by the name stored in ifr.
1907 * Return an errno or 0.
1910 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1913 struct ifnet *theywant;
1917 theywant = ifunit(ifr->ifr_name);
1918 if (theywant == NULL || theywant->if_bpf == NULL)
1921 bp = theywant->if_bpf;
1923 /* Check if interface is not being detached from BPF */
1925 if (bp->flags & BPFIF_FLAG_DYING) {
1932 * Behavior here depends on the buffering model. If we're using
1933 * kernel memory buffers, then we can allocate them here. If we're
1934 * using zero-copy, then the user process must have registered
1935 * buffers by the time we get here. If not, return an error.
1937 switch (d->bd_bufmode) {
1938 case BPF_BUFMODE_BUFFER:
1939 case BPF_BUFMODE_ZBUF:
1940 if (d->bd_sbuf == NULL)
1945 panic("bpf_setif: bufmode %d", d->bd_bufmode);
1947 if (bp != d->bd_bif)
1956 * Support for select() and poll() system calls
1958 * Return true iff the specific operation will not block indefinitely.
1959 * Otherwise, return false but make a note that a selwakeup() must be done.
1962 bpfpoll(struct cdev *dev, int events, struct thread *td)
1967 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL)
1969 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
1972 * Refresh PID associated with this descriptor.
1974 revents = events & (POLLOUT | POLLWRNORM);
1976 BPF_PID_REFRESH(d, td);
1977 if (events & (POLLIN | POLLRDNORM)) {
1979 revents |= events & (POLLIN | POLLRDNORM);
1981 selrecord(td, &d->bd_sel);
1982 /* Start the read timeout if necessary. */
1983 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1984 callout_reset(&d->bd_callout, d->bd_rtout,
1986 d->bd_state = BPF_WAITING;
1995 * Support for kevent() system call. Register EVFILT_READ filters and
1996 * reject all others.
1999 bpfkqfilter(struct cdev *dev, struct knote *kn)
2003 if (devfs_get_cdevpriv((void **)&d) != 0 ||
2004 kn->kn_filter != EVFILT_READ)
2008 * Refresh PID associated with this descriptor.
2011 BPF_PID_REFRESH_CUR(d);
2012 kn->kn_fop = &bpfread_filtops;
2014 knlist_add(&d->bd_sel.si_note, kn, 1);
2021 filt_bpfdetach(struct knote *kn)
2023 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
2025 knlist_remove(&d->bd_sel.si_note, kn, 0);
2029 filt_bpfread(struct knote *kn, long hint)
2031 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
2034 BPFD_LOCK_ASSERT(d);
2035 ready = bpf_ready(d);
2037 kn->kn_data = d->bd_slen;
2038 while (d->bd_hbuf_in_use)
2039 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2040 PRINET, "bd_hbuf", 0);
2042 kn->kn_data += d->bd_hlen;
2043 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
2044 callout_reset(&d->bd_callout, d->bd_rtout,
2046 d->bd_state = BPF_WAITING;
2052 #define BPF_TSTAMP_NONE 0
2053 #define BPF_TSTAMP_FAST 1
2054 #define BPF_TSTAMP_NORMAL 2
2055 #define BPF_TSTAMP_EXTERN 3
2058 bpf_ts_quality(int tstype)
2061 if (tstype == BPF_T_NONE)
2062 return (BPF_TSTAMP_NONE);
2063 if ((tstype & BPF_T_FAST) != 0)
2064 return (BPF_TSTAMP_FAST);
2066 return (BPF_TSTAMP_NORMAL);
2070 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m)
2075 quality = bpf_ts_quality(tstype);
2076 if (quality == BPF_TSTAMP_NONE)
2080 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL);
2082 *bt = *(struct bintime *)(tag + 1);
2083 return (BPF_TSTAMP_EXTERN);
2086 if (quality == BPF_TSTAMP_NORMAL)
2095 * Incoming linkage from device drivers. Process the packet pkt, of length
2096 * pktlen, which is stored in a contiguous buffer. The packet is parsed
2097 * by each process' filter, and if accepted, stashed into the corresponding
2101 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2111 gottime = BPF_TSTAMP_NONE;
2115 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2117 * We are not using any locks for d here because:
2118 * 1) any filter change is protected by interface
2120 * 2) destroying/detaching d is protected by interface
2124 /* XXX: Do not protect counter for the sake of performance. */
2127 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no
2128 * way for the caller to indiciate to us whether this packet
2129 * is inbound or outbound. In the bpf_mtap() routines, we use
2130 * the interface pointers on the mbuf to figure it out.
2133 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2135 slen = (*(bf->func))(pkt, pktlen, pktlen);
2138 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
2141 * Filter matches. Let's to acquire write lock.
2146 if (gottime < bpf_ts_quality(d->bd_tstamp))
2147 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL);
2149 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2151 catchpacket(d, pkt, pktlen, slen,
2152 bpf_append_bytes, &bt);
2159 #define BPF_CHECK_DIRECTION(d, r, i) \
2160 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \
2161 ((d)->bd_direction == BPF_D_OUT && (r) == (i)))
2164 * Incoming linkage from device drivers, when packet is in an mbuf chain.
2165 * Locking model is explained in bpf_tap().
2168 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2178 /* Skip outgoing duplicate packets. */
2179 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2180 m->m_flags &= ~M_PROMISC;
2184 pktlen = m_length(m, NULL);
2185 gottime = BPF_TSTAMP_NONE;
2189 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2190 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2194 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2195 /* XXX We cannot handle multiple mbufs. */
2196 if (bf != NULL && m->m_next == NULL)
2197 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen);
2200 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
2205 if (gottime < bpf_ts_quality(d->bd_tstamp))
2206 gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2208 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2210 catchpacket(d, (u_char *)m, pktlen, slen,
2211 bpf_append_mbuf, &bt);
2219 * Incoming linkage from device drivers, when packet is in
2220 * an mbuf chain and to be prepended by a contiguous header.
2223 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
2231 /* Skip outgoing duplicate packets. */
2232 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2233 m->m_flags &= ~M_PROMISC;
2237 pktlen = m_length(m, NULL);
2239 * Craft on-stack mbuf suitable for passing to bpf_filter.
2240 * Note that we cut corners here; we only setup what's
2241 * absolutely needed--this mbuf should never go anywhere else.
2248 gottime = BPF_TSTAMP_NONE;
2252 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2253 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2256 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0);
2261 if (gottime < bpf_ts_quality(d->bd_tstamp))
2262 gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2264 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2266 catchpacket(d, (u_char *)&mb, pktlen, slen,
2267 bpf_append_mbuf, &bt);
2274 #undef BPF_CHECK_DIRECTION
2276 #undef BPF_TSTAMP_NONE
2277 #undef BPF_TSTAMP_FAST
2278 #undef BPF_TSTAMP_NORMAL
2279 #undef BPF_TSTAMP_EXTERN
2282 bpf_hdrlen(struct bpf_d *d)
2286 hdrlen = d->bd_bif->bif_hdrlen;
2287 #ifndef BURN_BRIDGES
2288 if (d->bd_tstamp == BPF_T_NONE ||
2289 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME)
2290 #ifdef COMPAT_FREEBSD32
2292 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32);
2295 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr);
2298 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr);
2299 #ifdef COMPAT_FREEBSD32
2301 hdrlen = BPF_WORDALIGN32(hdrlen);
2304 hdrlen = BPF_WORDALIGN(hdrlen);
2306 return (hdrlen - d->bd_bif->bif_hdrlen);
2310 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype)
2314 struct timespec tsn;
2316 if ((tstype & BPF_T_MONOTONIC) == 0) {
2318 bintime_add(&bt2, &boottimebin);
2321 switch (BPF_T_FORMAT(tstype)) {
2322 case BPF_T_MICROTIME:
2323 bintime2timeval(bt, &tsm);
2324 ts->bt_sec = tsm.tv_sec;
2325 ts->bt_frac = tsm.tv_usec;
2327 case BPF_T_NANOTIME:
2328 bintime2timespec(bt, &tsn);
2329 ts->bt_sec = tsn.tv_sec;
2330 ts->bt_frac = tsn.tv_nsec;
2333 ts->bt_sec = bt->sec;
2334 ts->bt_frac = bt->frac;
2340 * Move the packet data from interface memory (pkt) into the
2341 * store buffer. "cpfn" is the routine called to do the actual data
2342 * transfer. bcopy is passed in to copy contiguous chunks, while
2343 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case,
2344 * pkt is really an mbuf.
2347 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
2348 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int),
2351 struct bpf_xhdr hdr;
2352 #ifndef BURN_BRIDGES
2353 struct bpf_hdr hdr_old;
2354 #ifdef COMPAT_FREEBSD32
2355 struct bpf_hdr32 hdr32_old;
2358 int caplen, curlen, hdrlen, totlen;
2363 BPFD_LOCK_ASSERT(d);
2366 * Detect whether user space has released a buffer back to us, and if
2367 * so, move it from being a hold buffer to a free buffer. This may
2368 * not be the best place to do it (for example, we might only want to
2369 * run this check if we need the space), but for now it's a reliable
2372 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) {
2373 while (d->bd_hbuf_in_use)
2374 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2375 PRINET, "bd_hbuf", 0);
2376 d->bd_fbuf = d->bd_hbuf;
2379 bpf_buf_reclaimed(d);
2383 * Figure out how many bytes to move. If the packet is
2384 * greater or equal to the snapshot length, transfer that
2385 * much. Otherwise, transfer the whole packet (unless
2386 * we hit the buffer size limit).
2388 hdrlen = bpf_hdrlen(d);
2389 totlen = hdrlen + min(snaplen, pktlen);
2390 if (totlen > d->bd_bufsize)
2391 totlen = d->bd_bufsize;
2394 * Round up the end of the previous packet to the next longword.
2396 * Drop the packet if there's no room and no hope of room
2397 * If the packet would overflow the storage buffer or the storage
2398 * buffer is considered immutable by the buffer model, try to rotate
2399 * the buffer and wakeup pending processes.
2401 #ifdef COMPAT_FREEBSD32
2403 curlen = BPF_WORDALIGN32(d->bd_slen);
2406 curlen = BPF_WORDALIGN(d->bd_slen);
2407 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) {
2408 if (d->bd_fbuf == NULL) {
2410 * There's no room in the store buffer, and no
2411 * prospect of room, so drop the packet. Notify the
2418 while (d->bd_hbuf_in_use)
2419 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2420 PRINET, "bd_hbuf", 0);
2424 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT)
2426 * Immediate mode is set, or the read timeout has already
2427 * expired during a select call. A packet arrived, so the
2428 * reader should be woken up.
2431 caplen = totlen - hdrlen;
2432 tstype = d->bd_tstamp;
2433 do_timestamp = tstype != BPF_T_NONE;
2434 #ifndef BURN_BRIDGES
2435 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) {
2438 bpf_bintime2ts(bt, &ts, tstype);
2439 #ifdef COMPAT_FREEBSD32
2440 if (d->bd_compat32) {
2441 bzero(&hdr32_old, sizeof(hdr32_old));
2443 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec;
2444 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac;
2446 hdr32_old.bh_datalen = pktlen;
2447 hdr32_old.bh_hdrlen = hdrlen;
2448 hdr32_old.bh_caplen = caplen;
2449 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old,
2454 bzero(&hdr_old, sizeof(hdr_old));
2456 hdr_old.bh_tstamp.tv_sec = ts.bt_sec;
2457 hdr_old.bh_tstamp.tv_usec = ts.bt_frac;
2459 hdr_old.bh_datalen = pktlen;
2460 hdr_old.bh_hdrlen = hdrlen;
2461 hdr_old.bh_caplen = caplen;
2462 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old,
2469 * Append the bpf header. Note we append the actual header size, but
2470 * move forward the length of the header plus padding.
2472 bzero(&hdr, sizeof(hdr));
2474 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype);
2475 hdr.bh_datalen = pktlen;
2476 hdr.bh_hdrlen = hdrlen;
2477 hdr.bh_caplen = caplen;
2478 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr));
2481 * Copy the packet data into the store buffer and update its length.
2483 #ifndef BURN_BRIDGES
2486 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen);
2487 d->bd_slen = curlen + totlen;
2494 * Free buffers currently in use by a descriptor.
2498 bpf_freed(struct bpf_d *d)
2502 * We don't need to lock out interrupts since this descriptor has
2503 * been detached from its interface and it yet hasn't been marked
2507 if (d->bd_rfilter != NULL) {
2508 free((caddr_t)d->bd_rfilter, M_BPF);
2510 if (d->bd_bfilter != NULL)
2511 bpf_destroy_jit_filter(d->bd_bfilter);
2514 if (d->bd_wfilter != NULL)
2515 free((caddr_t)d->bd_wfilter, M_BPF);
2516 mtx_destroy(&d->bd_lock);
2520 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the
2521 * fixed size of the link header (variable length headers not yet supported).
2524 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2527 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2531 * Attach an interface to bpf. ifp is a pointer to the structure
2532 * defining the interface to be attached, dlt is the link layer type,
2533 * and hdrlen is the fixed size of the link header (variable length
2534 * headers are not yet supporrted).
2537 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2541 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
2545 LIST_INIT(&bp->bif_dlist);
2546 LIST_INIT(&bp->bif_wlist);
2549 rw_init(&bp->bif_lock, "bpf interface lock");
2550 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
2554 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
2557 bp->bif_hdrlen = hdrlen;
2560 if_printf(ifp, "bpf attached\n");
2564 * Detach bpf from an interface. This involves detaching each descriptor
2565 * associated with the interface. Notify each descriptor as it's detached
2566 * so that any sleepers wake up and get ENXIO.
2569 bpfdetach(struct ifnet *ifp)
2580 /* Find all bpf_if struct's which reference ifp and detach them. */
2582 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2583 if (ifp == bp->bif_ifp)
2587 LIST_REMOVE(bp, bif_next);
2593 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
2594 bpf_detachd_locked(d);
2599 /* Free writer-only descriptors */
2600 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) {
2601 bpf_detachd_locked(d);
2608 * Delay freing bp till interface is detached
2609 * and all routes through this interface are removed.
2610 * Mark bp as detached to restrict new consumers.
2613 bp->flags |= BPFIF_FLAG_DYING;
2616 } while (bp != NULL);
2621 printf("bpfdetach: %s was not attached\n", ifp->if_xname);
2626 * Interface departure handler.
2627 * Note departure event does not guarantee interface is going down.
2630 bpf_ifdetach(void *arg __unused, struct ifnet *ifp)
2635 if ((bp = ifp->if_bpf) == NULL) {
2640 /* Check if bpfdetach() was called previously */
2641 if ((bp->flags & BPFIF_FLAG_DYING) == 0) {
2646 CTR3(KTR_NET, "%s: freing BPF instance %p for interface %p",
2652 rw_destroy(&bp->bif_lock);
2657 * Get a list of available data link type of the interface.
2660 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
2668 ifp = d->bd_bif->bif_ifp;
2671 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2672 if (bp->bif_ifp != ifp)
2674 if (bfl->bfl_list != NULL) {
2675 if (n >= bfl->bfl_len)
2677 error = copyout(&bp->bif_dlt,
2678 bfl->bfl_list + n, sizeof(u_int));
2687 * Set the data link type of a BPF instance.
2690 bpf_setdlt(struct bpf_d *d, u_int dlt)
2692 int error, opromisc;
2698 if (d->bd_bif->bif_dlt == dlt)
2700 ifp = d->bd_bif->bif_ifp;
2702 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2703 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
2708 opromisc = d->bd_promisc;
2714 error = ifpromisc(bp->bif_ifp, 1);
2716 if_printf(bp->bif_ifp,
2717 "bpf_setdlt: ifpromisc failed (%d)\n",
2723 return (bp == NULL ? EINVAL : 0);
2727 bpf_drvinit(void *unused)
2731 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
2732 LIST_INIT(&bpf_iflist);
2734 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf");
2735 /* For compatibility */
2736 make_dev_alias(dev, "bpf0");
2738 /* Register interface departure handler */
2739 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER(
2740 ifnet_departure_event, bpf_ifdetach, NULL,
2741 EVENTHANDLER_PRI_ANY);
2745 * Zero out the various packet counters associated with all of the bpf
2746 * descriptors. At some point, we will probably want to get a bit more
2747 * granular and allow the user to specify descriptors to be zeroed.
2750 bpf_zero_counters(void)
2756 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2758 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2774 * Fill filter statistics
2777 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
2780 bzero(d, sizeof(*d));
2781 BPFD_LOCK_ASSERT(bd);
2782 d->bd_structsize = sizeof(*d);
2783 /* XXX: reading should be protected by global lock */
2784 d->bd_immediate = bd->bd_immediate;
2785 d->bd_promisc = bd->bd_promisc;
2786 d->bd_hdrcmplt = bd->bd_hdrcmplt;
2787 d->bd_direction = bd->bd_direction;
2788 d->bd_feedback = bd->bd_feedback;
2789 d->bd_async = bd->bd_async;
2790 d->bd_rcount = bd->bd_rcount;
2791 d->bd_dcount = bd->bd_dcount;
2792 d->bd_fcount = bd->bd_fcount;
2793 d->bd_sig = bd->bd_sig;
2794 d->bd_slen = bd->bd_slen;
2795 d->bd_hlen = bd->bd_hlen;
2796 d->bd_bufsize = bd->bd_bufsize;
2797 d->bd_pid = bd->bd_pid;
2798 strlcpy(d->bd_ifname,
2799 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
2800 d->bd_locked = bd->bd_locked;
2801 d->bd_wcount = bd->bd_wcount;
2802 d->bd_wdcount = bd->bd_wdcount;
2803 d->bd_wfcount = bd->bd_wfcount;
2804 d->bd_zcopy = bd->bd_zcopy;
2805 d->bd_bufmode = bd->bd_bufmode;
2809 * Handle `netstat -B' stats request
2812 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS)
2814 static const struct xbpf_d zerostats;
2815 struct xbpf_d *xbdbuf, *xbd, tempstats;
2821 * XXX This is not technically correct. It is possible for non
2822 * privileged users to open bpf devices. It would make sense
2823 * if the users who opened the devices were able to retrieve
2824 * the statistics for them, too.
2826 error = priv_check(req->td, PRIV_NET_BPF);
2830 * Check to see if the user is requesting that the counters be
2831 * zeroed out. Explicitly check that the supplied data is zeroed,
2832 * as we aren't allowing the user to set the counters currently.
2834 if (req->newptr != NULL) {
2835 if (req->newlen != sizeof(tempstats))
2837 memset(&tempstats, 0, sizeof(tempstats));
2838 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats));
2841 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0)
2843 bpf_zero_counters();
2846 if (req->oldptr == NULL)
2847 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd)));
2848 if (bpf_bpfd_cnt == 0)
2849 return (SYSCTL_OUT(req, 0, 0));
2850 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK);
2852 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) {
2854 free(xbdbuf, M_BPF);
2858 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2860 /* Send writers-only first */
2861 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) {
2862 xbd = &xbdbuf[index++];
2864 bpfstats_fill_xbpf(xbd, bd);
2867 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2868 xbd = &xbdbuf[index++];
2870 bpfstats_fill_xbpf(xbd, bd);
2876 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd));
2877 free(xbdbuf, M_BPF);
2881 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL);
2883 #else /* !DEV_BPF && !NETGRAPH_BPF */
2885 * NOP stubs to allow bpf-using drivers to load and function.
2887 * A 'better' implementation would allow the core bpf functionality
2888 * to be loaded at runtime.
2890 static struct bpf_if bp_null;
2893 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2898 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2903 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m)
2908 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2911 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2915 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2918 *driverp = &bp_null;
2922 bpfdetach(struct ifnet *ifp)
2927 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
2929 return -1; /* "no filter" behaviour */
2933 bpf_validate(const struct bpf_insn *f, int len)
2935 return 0; /* false */
2938 #endif /* !DEV_BPF && !NETGRAPH_BPF */