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>
71 #include <net/if_var.h>
74 #include <net/bpf_buffer.h>
76 #include <net/bpf_jitter.h>
78 #include <net/bpf_zerocopy.h>
79 #include <net/bpfdesc.h>
82 #include <netinet/in.h>
83 #include <netinet/if_ether.h>
84 #include <sys/kernel.h>
85 #include <sys/sysctl.h>
87 #include <net80211/ieee80211_freebsd.h>
89 #include <security/mac/mac_framework.h>
91 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
93 #if defined(DEV_BPF) || defined(NETGRAPH_BPF)
95 #define PRINET 26 /* interruptible */
97 #define SIZEOF_BPF_HDR(type) \
98 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen))
100 #ifdef COMPAT_FREEBSD32
101 #include <sys/mount.h>
102 #include <compat/freebsd32/freebsd32.h>
103 #define BPF_ALIGNMENT32 sizeof(int32_t)
104 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
108 * 32-bit version of structure prepended to each packet. We use this header
109 * instead of the standard one for 32-bit streams. We mark the a stream as
110 * 32-bit the first time we see a 32-bit compat ioctl request.
113 struct timeval32 bh_tstamp; /* time stamp */
114 uint32_t bh_caplen; /* length of captured portion */
115 uint32_t bh_datalen; /* original length of packet */
116 uint16_t bh_hdrlen; /* length of bpf header (this struct
117 plus alignment padding) */
121 struct bpf_program32 {
126 struct bpf_dltlist32 {
131 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32)
132 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32)
133 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32)
134 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32)
135 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32)
136 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32)
140 * bpf_iflist is a list of BPF interface structures, each corresponding to a
141 * specific DLT. The same network interface might have several BPF interface
142 * structures registered by different layers in the stack (i.e., 802.11
143 * frames, ethernet frames, etc).
145 static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist;
146 static struct mtx bpf_mtx; /* bpf global lock */
147 static int bpf_bpfd_cnt;
149 static void bpf_attachd(struct bpf_d *, struct bpf_if *);
150 static void bpf_detachd(struct bpf_d *);
151 static void bpf_detachd_locked(struct bpf_d *);
152 static void bpf_freed(struct bpf_d *);
153 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **,
154 struct sockaddr *, int *, struct bpf_insn *);
155 static int bpf_setif(struct bpf_d *, struct ifreq *);
156 static void bpf_timed_out(void *);
158 bpf_wakeup(struct bpf_d *);
159 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
160 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int),
162 static void reset_d(struct bpf_d *);
163 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
164 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
165 static int bpf_setdlt(struct bpf_d *, u_int);
166 static void filt_bpfdetach(struct knote *);
167 static int filt_bpfread(struct knote *, long);
168 static void bpf_drvinit(void *);
169 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS);
171 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl");
172 int bpf_maxinsns = BPF_MAXINSNS;
173 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW,
174 &bpf_maxinsns, 0, "Maximum bpf program instructions");
175 static int bpf_zerocopy_enable = 0;
176 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW,
177 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions");
178 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW,
179 bpf_stats_sysctl, "bpf statistics portal");
181 static VNET_DEFINE(int, bpf_optimize_writers) = 0;
182 #define V_bpf_optimize_writers VNET(bpf_optimize_writers)
183 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RW,
184 &VNET_NAME(bpf_optimize_writers), 0,
185 "Do not send packets until BPF program is set");
187 static d_open_t bpfopen;
188 static d_read_t bpfread;
189 static d_write_t bpfwrite;
190 static d_ioctl_t bpfioctl;
191 static d_poll_t bpfpoll;
192 static d_kqfilter_t bpfkqfilter;
194 static struct cdevsw bpf_cdevsw = {
195 .d_version = D_VERSION,
202 .d_kqfilter = bpfkqfilter,
205 static struct filterops bpfread_filtops = {
207 .f_detach = filt_bpfdetach,
208 .f_event = filt_bpfread,
211 eventhandler_tag bpf_ifdetach_cookie = NULL;
214 * LOCKING MODEL USED BY BPF:
216 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal,
217 * some global counters and every bpf_if reference.
218 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters.
219 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields
220 * used by bpf_mtap code.
224 * Global lock, interface lock, descriptor lock
226 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2]
227 * working model. In many places (like bpf_detachd) we start with BPF descriptor
228 * (and we need to at least rlock it to get reliable interface pointer). This
229 * gives us potential LOR. As a result, we use global lock to protect from bpf_if
230 * change in every such place.
232 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and
233 * 3) descriptor main wlock.
234 * Reading bd_bif can be protected by any of these locks, typically global lock.
236 * Changing read/write BPF filter is protected by the same three locks,
237 * the same applies for reading.
239 * Sleeping in global lock is not allowed due to bpfdetach() using it.
243 * Wrapper functions for various buffering methods. If the set of buffer
244 * modes expands, we will probably want to introduce a switch data structure
245 * similar to protosw, et.
248 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
254 switch (d->bd_bufmode) {
255 case BPF_BUFMODE_BUFFER:
256 return (bpf_buffer_append_bytes(d, buf, offset, src, len));
258 case BPF_BUFMODE_ZBUF:
260 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len));
263 panic("bpf_buf_append_bytes");
268 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
274 switch (d->bd_bufmode) {
275 case BPF_BUFMODE_BUFFER:
276 return (bpf_buffer_append_mbuf(d, buf, offset, src, len));
278 case BPF_BUFMODE_ZBUF:
280 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len));
283 panic("bpf_buf_append_mbuf");
288 * This function gets called when the free buffer is re-assigned.
291 bpf_buf_reclaimed(struct bpf_d *d)
296 switch (d->bd_bufmode) {
297 case BPF_BUFMODE_BUFFER:
300 case BPF_BUFMODE_ZBUF:
301 bpf_zerocopy_buf_reclaimed(d);
305 panic("bpf_buf_reclaimed");
310 * If the buffer mechanism has a way to decide that a held buffer can be made
311 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is
312 * returned if the buffer can be discarded, (0) is returned if it cannot.
315 bpf_canfreebuf(struct bpf_d *d)
320 switch (d->bd_bufmode) {
321 case BPF_BUFMODE_ZBUF:
322 return (bpf_zerocopy_canfreebuf(d));
328 * Allow the buffer model to indicate that the current store buffer is
329 * immutable, regardless of the appearance of space. Return (1) if the
330 * buffer is writable, and (0) if not.
333 bpf_canwritebuf(struct bpf_d *d)
337 switch (d->bd_bufmode) {
338 case BPF_BUFMODE_ZBUF:
339 return (bpf_zerocopy_canwritebuf(d));
345 * Notify buffer model that an attempt to write to the store buffer has
346 * resulted in a dropped packet, in which case the buffer may be considered
350 bpf_buffull(struct bpf_d *d)
355 switch (d->bd_bufmode) {
356 case BPF_BUFMODE_ZBUF:
357 bpf_zerocopy_buffull(d);
363 * Notify the buffer model that a buffer has moved into the hold position.
366 bpf_bufheld(struct bpf_d *d)
371 switch (d->bd_bufmode) {
372 case BPF_BUFMODE_ZBUF:
373 bpf_zerocopy_bufheld(d);
379 bpf_free(struct bpf_d *d)
382 switch (d->bd_bufmode) {
383 case BPF_BUFMODE_BUFFER:
384 return (bpf_buffer_free(d));
386 case BPF_BUFMODE_ZBUF:
387 return (bpf_zerocopy_free(d));
390 panic("bpf_buf_free");
395 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
398 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
400 return (bpf_buffer_uiomove(d, buf, len, uio));
404 bpf_ioctl_sblen(struct bpf_d *d, u_int *i)
407 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
409 return (bpf_buffer_ioctl_sblen(d, i));
413 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i)
416 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
418 return (bpf_zerocopy_ioctl_getzmax(td, d, i));
422 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
425 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
427 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz));
431 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
434 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
436 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz));
440 * General BPF functions.
443 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp,
444 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter)
446 const struct ieee80211_bpf_params *p;
447 struct ether_header *eh;
455 * Build a sockaddr based on the data link layer type.
456 * We do this at this level because the ethernet header
457 * is copied directly into the data field of the sockaddr.
458 * In the case of SLIP, there is no header and the packet
459 * is forwarded as is.
460 * Also, we are careful to leave room at the front of the mbuf
461 * for the link level header.
466 sockp->sa_family = AF_INET;
471 sockp->sa_family = AF_UNSPEC;
472 /* XXX Would MAXLINKHDR be better? */
473 hlen = ETHER_HDR_LEN;
477 sockp->sa_family = AF_IMPLINK;
482 sockp->sa_family = AF_UNSPEC;
488 * null interface types require a 4 byte pseudo header which
489 * corresponds to the address family of the packet.
491 sockp->sa_family = AF_UNSPEC;
495 case DLT_ATM_RFC1483:
497 * en atm driver requires 4-byte atm pseudo header.
498 * though it isn't standard, vpi:vci needs to be
501 sockp->sa_family = AF_UNSPEC;
502 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
506 sockp->sa_family = AF_UNSPEC;
507 hlen = 4; /* This should match PPP_HDRLEN */
510 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
511 sockp->sa_family = AF_IEEE80211;
515 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
516 sockp->sa_family = AF_IEEE80211;
517 sockp->sa_len = 12; /* XXX != 0 */
518 hlen = sizeof(struct ieee80211_bpf_params);
525 len = uio->uio_resid;
526 if (len < hlen || len - hlen > ifp->if_mtu)
529 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR);
532 m->m_pkthdr.len = m->m_len = len;
535 error = uiomove(mtod(m, u_char *), len, uio);
539 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
545 /* Check for multicast destination */
548 eh = mtod(m, struct ether_header *);
549 if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
550 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
551 ETHER_ADDR_LEN) == 0)
552 m->m_flags |= M_BCAST;
554 m->m_flags |= M_MCAST;
560 * Make room for link header, and copy it to sockaddr
563 if (sockp->sa_family == AF_IEEE80211) {
565 * Collect true length from the parameter header
566 * NB: sockp is known to be zero'd so if we do a
567 * short copy unspecified parameters will be
569 * NB: packet may not be aligned after stripping
573 p = mtod(m, const struct ieee80211_bpf_params *);
575 if (hlen > sizeof(sockp->sa_data)) {
580 bcopy(mtod(m, const void *), sockp->sa_data, hlen);
591 * Attach file to the bpf interface, i.e. make d listen on bp.
594 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
601 * Save sysctl value to protect from sysctl change
604 op_w = V_bpf_optimize_writers;
606 if (d->bd_bif != NULL)
607 bpf_detachd_locked(d);
609 * Point d at bp, and add d to the interface's list.
610 * Since there are many applicaiotns using BPF for
611 * sending raw packets only (dhcpd, cdpd are good examples)
612 * we can delay adding d to the list of active listeners until
613 * some filter is configured.
622 /* Add to writers-only list */
623 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next);
625 * We decrement bd_writer on every filter set operation.
626 * First BIOCSETF is done by pcap_open_live() to set up
627 * snap length. After that appliation usually sets its own filter
631 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
638 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list",
639 __func__, d->bd_pid, d->bd_writer ? "writer" : "active");
642 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
646 * Check if we need to upgrade our descriptor @d from write-only mode.
649 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen)
651 int is_snap, need_upgrade;
654 * Check if we've already upgraded or new filter is empty.
656 if (d->bd_writer == 0 || fcode == NULL)
662 * Check if cmd looks like snaplen setting from
663 * pcap_bpf.c:pcap_open_live().
664 * Note we're not checking .k value here:
665 * while pcap_open_live() definitely sets to to non-zero value,
666 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g.
667 * do not consider upgrading immediately
669 if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K))
676 * We're setting first filter and it doesn't look like
677 * setting snaplen. We're probably using bpf directly.
678 * Upgrade immediately.
683 * Do not require upgrade by first BIOCSETF
684 * (used to set snaplen) by pcap_open_live().
687 if (--d->bd_writer == 0) {
689 * First snaplen filter has already
690 * been set. This is probably catch-all
698 "%s: filter function set by pid %d, "
699 "bd_writer counter %d, snap %d upgrade %d",
700 __func__, d->bd_pid, d->bd_writer,
701 is_snap, need_upgrade);
703 return (need_upgrade);
707 * Add d to the list of active bp filters.
708 * Reuqires bpf_attachd() to be called before
711 bpf_upgraded(struct bpf_d *d)
720 * Filter can be set several times without specifying interface.
721 * Mark d as reader and exit.
733 /* Remove from writers-only list */
734 LIST_REMOVE(d, bd_next);
735 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
736 /* Mark d as reader */
742 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid);
744 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
748 * Detach a file from its interface.
751 bpf_detachd(struct bpf_d *d)
754 bpf_detachd_locked(d);
759 bpf_detachd_locked(struct bpf_d *d)
765 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid);
769 /* Check if descriptor is attached */
770 if ((bp = d->bd_bif) == NULL)
776 /* Save bd_writer value */
777 error = d->bd_writer;
780 * Remove d from the interface's descriptor list.
782 LIST_REMOVE(d, bd_next);
791 /* Call event handler iff d is attached */
793 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
796 * Check if this descriptor had requested promiscuous mode.
797 * If so, turn it off.
801 CURVNET_SET(ifp->if_vnet);
802 error = ifpromisc(ifp, 0);
804 if (error != 0 && error != ENXIO) {
806 * ENXIO can happen if a pccard is unplugged
807 * Something is really wrong if we were able to put
808 * the driver into promiscuous mode, but can't
811 if_printf(bp->bif_ifp,
812 "bpf_detach: ifpromisc failed (%d)\n", error);
818 * Close the descriptor by detaching it from its interface,
819 * deallocating its buffers, and marking it free.
824 struct bpf_d *d = data;
827 if (d->bd_state == BPF_WAITING)
828 callout_stop(&d->bd_callout);
829 d->bd_state = BPF_IDLE;
831 funsetown(&d->bd_sigio);
834 mac_bpfdesc_destroy(d);
836 seldrain(&d->bd_sel);
837 knlist_destroy(&d->bd_sel.si_note);
838 callout_drain(&d->bd_callout);
844 * Open ethernet device. Returns ENXIO for illegal minor device number,
845 * EBUSY if file is open by another process.
849 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td)
854 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
855 error = devfs_set_cdevpriv(d, bpf_dtor);
862 * For historical reasons, perform a one-time initialization call to
863 * the buffer routines, even though we're not yet committed to a
864 * particular buffer method.
867 d->bd_hbuf_in_use = 0;
868 d->bd_bufmode = BPF_BUFMODE_BUFFER;
870 d->bd_direction = BPF_D_INOUT;
871 BPF_PID_REFRESH(d, td);
874 mac_bpfdesc_create(td->td_ucred, d);
876 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF);
877 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0);
878 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock);
880 /* Allocate default buffers */
881 size = d->bd_bufsize;
882 bpf_buffer_ioctl_sblen(d, &size);
888 * bpfread - read next chunk of packets from buffers
891 bpfread(struct cdev *dev, struct uio *uio, int ioflag)
898 error = devfs_get_cdevpriv((void **)&d);
903 * Restrict application to use a buffer the same size as
906 if (uio->uio_resid != d->bd_bufsize)
909 non_block = ((ioflag & O_NONBLOCK) != 0);
912 BPF_PID_REFRESH_CUR(d);
913 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
917 if (d->bd_state == BPF_WAITING)
918 callout_stop(&d->bd_callout);
919 timed_out = (d->bd_state == BPF_TIMED_OUT);
920 d->bd_state = BPF_IDLE;
921 while (d->bd_hbuf_in_use) {
922 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
923 PRINET|PCATCH, "bd_hbuf", 0);
930 * If the hold buffer is empty, then do a timed sleep, which
931 * ends when the timeout expires or when enough packets
932 * have arrived to fill the store buffer.
934 while (d->bd_hbuf == NULL) {
935 if (d->bd_slen != 0) {
937 * A packet(s) either arrived since the previous
938 * read or arrived while we were asleep.
940 if (d->bd_immediate || non_block || timed_out) {
942 * Rotate the buffers and return what's here
943 * if we are in immediate mode, non-blocking
944 * flag is set, or this descriptor timed out.
952 * No data is available, check to see if the bpf device
953 * is still pointed at a real interface. If not, return
954 * ENXIO so that the userland process knows to rebind
955 * it before using it again.
957 if (d->bd_bif == NULL) {
964 return (EWOULDBLOCK);
966 error = msleep(d, &d->bd_lock, PRINET|PCATCH,
968 if (error == EINTR || error == ERESTART) {
972 if (error == EWOULDBLOCK) {
974 * On a timeout, return what's in the buffer,
975 * which may be nothing. If there is something
976 * in the store buffer, we can rotate the buffers.
980 * We filled up the buffer in between
981 * getting the timeout and arriving
982 * here, so we don't need to rotate.
986 if (d->bd_slen == 0) {
995 * At this point, we know we have something in the hold slot.
997 d->bd_hbuf_in_use = 1;
1001 * Move data from hold buffer into user space.
1002 * We know the entire buffer is transferred since
1003 * we checked above that the read buffer is bpf_bufsize bytes.
1005 * We do not have to worry about simultaneous reads because
1006 * we waited for sole access to the hold buffer above.
1008 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio);
1011 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf"));
1012 d->bd_fbuf = d->bd_hbuf;
1015 bpf_buf_reclaimed(d);
1016 d->bd_hbuf_in_use = 0;
1017 wakeup(&d->bd_hbuf_in_use);
1024 * If there are processes sleeping on this descriptor, wake them up.
1026 static __inline void
1027 bpf_wakeup(struct bpf_d *d)
1030 BPFD_LOCK_ASSERT(d);
1031 if (d->bd_state == BPF_WAITING) {
1032 callout_stop(&d->bd_callout);
1033 d->bd_state = BPF_IDLE;
1036 if (d->bd_async && d->bd_sig && d->bd_sigio)
1037 pgsigio(&d->bd_sigio, d->bd_sig, 0);
1039 selwakeuppri(&d->bd_sel, PRINET);
1040 KNOTE_LOCKED(&d->bd_sel.si_note, 0);
1044 bpf_timed_out(void *arg)
1046 struct bpf_d *d = (struct bpf_d *)arg;
1048 BPFD_LOCK_ASSERT(d);
1050 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout))
1052 if (d->bd_state == BPF_WAITING) {
1053 d->bd_state = BPF_TIMED_OUT;
1054 if (d->bd_slen != 0)
1060 bpf_ready(struct bpf_d *d)
1063 BPFD_LOCK_ASSERT(d);
1065 if (!bpf_canfreebuf(d) && d->bd_hlen != 0)
1067 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1074 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag)
1078 struct mbuf *m, *mc;
1079 struct sockaddr dst;
1082 error = devfs_get_cdevpriv((void **)&d);
1086 BPF_PID_REFRESH_CUR(d);
1088 /* XXX: locking required */
1089 if (d->bd_bif == NULL) {
1094 ifp = d->bd_bif->bif_ifp;
1096 if ((ifp->if_flags & IFF_UP) == 0) {
1101 if (uio->uio_resid == 0) {
1106 bzero(&dst, sizeof(dst));
1109 /* XXX: bpf_movein() can sleep */
1110 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp,
1111 &m, &dst, &hlen, d->bd_wfilter);
1118 dst.sa_family = pseudo_AF_HDRCMPLT;
1120 if (d->bd_feedback) {
1121 mc = m_dup(m, M_NOWAIT);
1123 mc->m_pkthdr.rcvif = ifp;
1124 /* Set M_PROMISC for outgoing packets to be discarded. */
1125 if (d->bd_direction == BPF_D_INOUT)
1126 m->m_flags |= M_PROMISC;
1130 m->m_pkthdr.len -= hlen;
1132 m->m_data += hlen; /* XXX */
1134 CURVNET_SET(ifp->if_vnet);
1137 mac_bpfdesc_create_mbuf(d, m);
1139 mac_bpfdesc_create_mbuf(d, mc);
1143 error = (*ifp->if_output)(ifp, m, &dst, NULL);
1149 (*ifp->if_input)(ifp, mc);
1159 * Reset a descriptor by flushing its packet buffer and clearing the receive
1160 * and drop counts. This is doable for kernel-only buffers, but with
1161 * zero-copy buffers, we can't write to (or rotate) buffers that are
1162 * currently owned by userspace. It would be nice if we could encapsulate
1163 * this logic in the buffer code rather than here.
1166 reset_d(struct bpf_d *d)
1169 BPFD_LOCK_ASSERT(d);
1171 while (d->bd_hbuf_in_use)
1172 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET,
1174 if ((d->bd_hbuf != NULL) &&
1175 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) {
1176 /* Free the hold buffer. */
1177 d->bd_fbuf = d->bd_hbuf;
1180 bpf_buf_reclaimed(d);
1182 if (bpf_canwritebuf(d))
1194 * FIONREAD Check for read packet available.
1195 * BIOCGBLEN Get buffer len [for read()].
1196 * BIOCSETF Set read filter.
1197 * BIOCSETFNR Set read filter without resetting descriptor.
1198 * BIOCSETWF Set write filter.
1199 * BIOCFLUSH Flush read packet buffer.
1200 * BIOCPROMISC Put interface into promiscuous mode.
1201 * BIOCGDLT Get link layer type.
1202 * BIOCGETIF Get interface name.
1203 * BIOCSETIF Set interface.
1204 * BIOCSRTIMEOUT Set read timeout.
1205 * BIOCGRTIMEOUT Get read timeout.
1206 * BIOCGSTATS Get packet stats.
1207 * BIOCIMMEDIATE Set immediate mode.
1208 * BIOCVERSION Get filter language version.
1209 * BIOCGHDRCMPLT Get "header already complete" flag
1210 * BIOCSHDRCMPLT Set "header already complete" flag
1211 * BIOCGDIRECTION Get packet direction flag
1212 * BIOCSDIRECTION Set packet direction flag
1213 * BIOCGTSTAMP Get time stamp format and resolution.
1214 * BIOCSTSTAMP Set time stamp format and resolution.
1215 * BIOCLOCK Set "locked" flag
1216 * BIOCFEEDBACK Set packet feedback mode.
1217 * BIOCSETZBUF Set current zero-copy buffer locations.
1218 * BIOCGETZMAX Get maximum zero-copy buffer size.
1219 * BIOCROTZBUF Force rotation of zero-copy buffer
1220 * BIOCSETBUFMODE Set buffer mode.
1221 * BIOCGETBUFMODE Get current buffer mode.
1225 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
1231 error = devfs_get_cdevpriv((void **)&d);
1236 * Refresh PID associated with this descriptor.
1239 BPF_PID_REFRESH(d, td);
1240 if (d->bd_state == BPF_WAITING)
1241 callout_stop(&d->bd_callout);
1242 d->bd_state = BPF_IDLE;
1245 if (d->bd_locked == 1) {
1251 #ifdef COMPAT_FREEBSD32
1252 case BIOCGDLTLIST32:
1256 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1257 case BIOCGRTIMEOUT32:
1268 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1269 case BIOCSRTIMEOUT32:
1279 #ifdef COMPAT_FREEBSD32
1281 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so
1282 * that it will get 32-bit packet headers.
1288 case BIOCGDLTLIST32:
1289 case BIOCGRTIMEOUT32:
1290 case BIOCSRTIMEOUT32:
1297 CURVNET_SET(TD_TO_VNET(td));
1305 * Check for read packet available.
1313 while (d->bd_hbuf_in_use)
1314 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
1315 PRINET, "bd_hbuf", 0);
1325 * Get buffer len [for read()].
1329 *(u_int *)addr = d->bd_bufsize;
1334 * Set buffer length.
1337 error = bpf_ioctl_sblen(d, (u_int *)addr);
1341 * Set link layer read filter.
1346 #ifdef COMPAT_FREEBSD32
1351 error = bpf_setf(d, (struct bpf_program *)addr, cmd);
1355 * Flush read packet buffer.
1364 * Put interface into promiscuous mode.
1367 if (d->bd_bif == NULL) {
1369 * No interface attached yet.
1374 if (d->bd_promisc == 0) {
1375 error = ifpromisc(d->bd_bif->bif_ifp, 1);
1382 * Get current data link type.
1386 if (d->bd_bif == NULL)
1389 *(u_int *)addr = d->bd_bif->bif_dlt;
1394 * Get a list of supported data link types.
1396 #ifdef COMPAT_FREEBSD32
1397 case BIOCGDLTLIST32:
1399 struct bpf_dltlist32 *list32;
1400 struct bpf_dltlist dltlist;
1402 list32 = (struct bpf_dltlist32 *)addr;
1403 dltlist.bfl_len = list32->bfl_len;
1404 dltlist.bfl_list = PTRIN(list32->bfl_list);
1406 if (d->bd_bif == NULL)
1409 error = bpf_getdltlist(d, &dltlist);
1411 list32->bfl_len = dltlist.bfl_len;
1420 if (d->bd_bif == NULL)
1423 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
1428 * Set data link type.
1432 if (d->bd_bif == NULL)
1435 error = bpf_setdlt(d, *(u_int *)addr);
1440 * Get interface name.
1444 if (d->bd_bif == NULL)
1447 struct ifnet *const ifp = d->bd_bif->bif_ifp;
1448 struct ifreq *const ifr = (struct ifreq *)addr;
1450 strlcpy(ifr->ifr_name, ifp->if_xname,
1451 sizeof(ifr->ifr_name));
1461 error = bpf_setif(d, (struct ifreq *)addr);
1469 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1470 case BIOCSRTIMEOUT32:
1473 struct timeval *tv = (struct timeval *)addr;
1474 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1475 struct timeval32 *tv32;
1476 struct timeval tv64;
1478 if (cmd == BIOCSRTIMEOUT32) {
1479 tv32 = (struct timeval32 *)addr;
1481 tv->tv_sec = tv32->tv_sec;
1482 tv->tv_usec = tv32->tv_usec;
1485 tv = (struct timeval *)addr;
1488 * Subtract 1 tick from tvtohz() since this isn't
1491 if ((error = itimerfix(tv)) == 0)
1492 d->bd_rtout = tvtohz(tv) - 1;
1500 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1501 case BIOCGRTIMEOUT32:
1505 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1506 struct timeval32 *tv32;
1507 struct timeval tv64;
1509 if (cmd == BIOCGRTIMEOUT32)
1513 tv = (struct timeval *)addr;
1515 tv->tv_sec = d->bd_rtout / hz;
1516 tv->tv_usec = (d->bd_rtout % hz) * tick;
1517 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1518 if (cmd == BIOCGRTIMEOUT32) {
1519 tv32 = (struct timeval32 *)addr;
1520 tv32->tv_sec = tv->tv_sec;
1521 tv32->tv_usec = tv->tv_usec;
1533 struct bpf_stat *bs = (struct bpf_stat *)addr;
1535 /* XXXCSJP overflow */
1536 bs->bs_recv = d->bd_rcount;
1537 bs->bs_drop = d->bd_dcount;
1542 * Set immediate mode.
1546 d->bd_immediate = *(u_int *)addr;
1552 struct bpf_version *bv = (struct bpf_version *)addr;
1554 bv->bv_major = BPF_MAJOR_VERSION;
1555 bv->bv_minor = BPF_MINOR_VERSION;
1560 * Get "header already complete" flag
1564 *(u_int *)addr = d->bd_hdrcmplt;
1569 * Set "header already complete" flag
1573 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
1578 * Get packet direction flag
1580 case BIOCGDIRECTION:
1582 *(u_int *)addr = d->bd_direction;
1587 * Set packet direction flag
1589 case BIOCSDIRECTION:
1593 direction = *(u_int *)addr;
1594 switch (direction) {
1599 d->bd_direction = direction;
1609 * Get packet timestamp format and resolution.
1613 *(u_int *)addr = d->bd_tstamp;
1618 * Set packet timestamp format and resolution.
1624 func = *(u_int *)addr;
1625 if (BPF_T_VALID(func))
1626 d->bd_tstamp = func;
1634 d->bd_feedback = *(u_int *)addr;
1644 case FIONBIO: /* Non-blocking I/O */
1647 case FIOASYNC: /* Send signal on receive packets */
1649 d->bd_async = *(int *)addr;
1655 * XXX: Add some sort of locking here?
1656 * fsetown() can sleep.
1658 error = fsetown(*(int *)addr, &d->bd_sigio);
1663 *(int *)addr = fgetown(&d->bd_sigio);
1667 /* This is deprecated, FIOSETOWN should be used instead. */
1669 error = fsetown(-(*(int *)addr), &d->bd_sigio);
1672 /* This is deprecated, FIOGETOWN should be used instead. */
1674 *(int *)addr = -fgetown(&d->bd_sigio);
1677 case BIOCSRSIG: /* Set receive signal */
1681 sig = *(u_int *)addr;
1694 *(u_int *)addr = d->bd_sig;
1698 case BIOCGETBUFMODE:
1700 *(u_int *)addr = d->bd_bufmode;
1704 case BIOCSETBUFMODE:
1706 * Allow the buffering mode to be changed as long as we
1707 * haven't yet committed to a particular mode. Our
1708 * definition of commitment, for now, is whether or not a
1709 * buffer has been allocated or an interface attached, since
1710 * that's the point where things get tricky.
1712 switch (*(u_int *)addr) {
1713 case BPF_BUFMODE_BUFFER:
1716 case BPF_BUFMODE_ZBUF:
1717 if (bpf_zerocopy_enable)
1727 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL ||
1728 d->bd_fbuf != NULL || d->bd_bif != NULL) {
1733 d->bd_bufmode = *(u_int *)addr;
1738 error = bpf_ioctl_getzmax(td, d, (size_t *)addr);
1742 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr);
1746 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr);
1754 * Set d's packet filter program to fp. If this file already has a filter,
1755 * free it and replace it. Returns EINVAL for bogus requests.
1757 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls
1758 * since reading d->bd_bif can't be protected by d or interface lock due to
1761 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses
1762 * interface read lock to read all filers.
1766 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1768 #ifdef COMPAT_FREEBSD32
1769 struct bpf_program fp_swab;
1770 struct bpf_program32 *fp32;
1772 struct bpf_insn *fcode, *old;
1774 bpf_jit_filter *jfunc, *ofunc;
1780 #ifdef COMPAT_FREEBSD32
1785 fp32 = (struct bpf_program32 *)fp;
1786 fp_swab.bf_len = fp32->bf_len;
1787 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns;
1803 jfunc = ofunc = NULL;
1808 * Check new filter validness before acquiring any locks.
1809 * Allocate memory for new filter, if needed.
1812 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0))
1814 size = flen * sizeof(*fp->bf_insns);
1816 /* We're setting up new filter. Copy and check actual data. */
1817 fcode = malloc(size, M_BPF, M_WAITOK);
1818 if (copyin(fp->bf_insns, fcode, size) != 0 ||
1819 !bpf_validate(fcode, flen)) {
1824 /* Filter is copied inside fcode and is perfectly valid. */
1825 jfunc = bpf_jitter(fcode, flen);
1832 * Set up new filter.
1833 * Protect filter change by interface lock.
1834 * Additionally, we are protected by global lock here.
1836 if (d->bd_bif != NULL)
1837 BPFIF_WLOCK(d->bd_bif);
1839 if (cmd == BIOCSETWF) {
1840 old = d->bd_wfilter;
1841 d->bd_wfilter = fcode;
1843 old = d->bd_rfilter;
1844 d->bd_rfilter = fcode;
1846 ofunc = d->bd_bfilter;
1847 d->bd_bfilter = jfunc;
1849 if (cmd == BIOCSETF)
1852 need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen);
1855 if (d->bd_bif != NULL)
1856 BPFIF_WUNLOCK(d->bd_bif);
1861 bpf_destroy_jit_filter(ofunc);
1864 /* Move d to active readers list. */
1865 if (need_upgrade != 0)
1873 * Detach a file from its current interface (if attached at all) and attach
1874 * to the interface indicated by the name stored in ifr.
1875 * Return an errno or 0.
1878 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1881 struct ifnet *theywant;
1885 theywant = ifunit(ifr->ifr_name);
1886 if (theywant == NULL || theywant->if_bpf == NULL)
1889 bp = theywant->if_bpf;
1891 /* Check if interface is not being detached from BPF */
1893 if (bp->flags & BPFIF_FLAG_DYING) {
1900 * Behavior here depends on the buffering model. If we're using
1901 * kernel memory buffers, then we can allocate them here. If we're
1902 * using zero-copy, then the user process must have registered
1903 * buffers by the time we get here. If not, return an error.
1905 switch (d->bd_bufmode) {
1906 case BPF_BUFMODE_BUFFER:
1907 case BPF_BUFMODE_ZBUF:
1908 if (d->bd_sbuf == NULL)
1913 panic("bpf_setif: bufmode %d", d->bd_bufmode);
1915 if (bp != d->bd_bif)
1924 * Support for select() and poll() system calls
1926 * Return true iff the specific operation will not block indefinitely.
1927 * Otherwise, return false but make a note that a selwakeup() must be done.
1930 bpfpoll(struct cdev *dev, int events, struct thread *td)
1935 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL)
1937 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
1940 * Refresh PID associated with this descriptor.
1942 revents = events & (POLLOUT | POLLWRNORM);
1944 BPF_PID_REFRESH(d, td);
1945 if (events & (POLLIN | POLLRDNORM)) {
1947 revents |= events & (POLLIN | POLLRDNORM);
1949 selrecord(td, &d->bd_sel);
1950 /* Start the read timeout if necessary. */
1951 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1952 callout_reset(&d->bd_callout, d->bd_rtout,
1954 d->bd_state = BPF_WAITING;
1963 * Support for kevent() system call. Register EVFILT_READ filters and
1964 * reject all others.
1967 bpfkqfilter(struct cdev *dev, struct knote *kn)
1971 if (devfs_get_cdevpriv((void **)&d) != 0 ||
1972 kn->kn_filter != EVFILT_READ)
1976 * Refresh PID associated with this descriptor.
1979 BPF_PID_REFRESH_CUR(d);
1980 kn->kn_fop = &bpfread_filtops;
1982 knlist_add(&d->bd_sel.si_note, kn, 1);
1989 filt_bpfdetach(struct knote *kn)
1991 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
1993 knlist_remove(&d->bd_sel.si_note, kn, 0);
1997 filt_bpfread(struct knote *kn, long hint)
1999 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
2002 BPFD_LOCK_ASSERT(d);
2003 ready = bpf_ready(d);
2005 kn->kn_data = d->bd_slen;
2006 while (d->bd_hbuf_in_use)
2007 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2008 PRINET, "bd_hbuf", 0);
2010 kn->kn_data += d->bd_hlen;
2011 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
2012 callout_reset(&d->bd_callout, d->bd_rtout,
2014 d->bd_state = BPF_WAITING;
2020 #define BPF_TSTAMP_NONE 0
2021 #define BPF_TSTAMP_FAST 1
2022 #define BPF_TSTAMP_NORMAL 2
2023 #define BPF_TSTAMP_EXTERN 3
2026 bpf_ts_quality(int tstype)
2029 if (tstype == BPF_T_NONE)
2030 return (BPF_TSTAMP_NONE);
2031 if ((tstype & BPF_T_FAST) != 0)
2032 return (BPF_TSTAMP_FAST);
2034 return (BPF_TSTAMP_NORMAL);
2038 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m)
2043 quality = bpf_ts_quality(tstype);
2044 if (quality == BPF_TSTAMP_NONE)
2048 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL);
2050 *bt = *(struct bintime *)(tag + 1);
2051 return (BPF_TSTAMP_EXTERN);
2054 if (quality == BPF_TSTAMP_NORMAL)
2063 * Incoming linkage from device drivers. Process the packet pkt, of length
2064 * pktlen, which is stored in a contiguous buffer. The packet is parsed
2065 * by each process' filter, and if accepted, stashed into the corresponding
2069 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2079 gottime = BPF_TSTAMP_NONE;
2083 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2085 * We are not using any locks for d here because:
2086 * 1) any filter change is protected by interface
2088 * 2) destroying/detaching d is protected by interface
2092 /* XXX: Do not protect counter for the sake of performance. */
2095 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no
2096 * way for the caller to indiciate to us whether this packet
2097 * is inbound or outbound. In the bpf_mtap() routines, we use
2098 * the interface pointers on the mbuf to figure it out.
2101 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2103 slen = (*(bf->func))(pkt, pktlen, pktlen);
2106 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
2109 * Filter matches. Let's to acquire write lock.
2114 if (gottime < bpf_ts_quality(d->bd_tstamp))
2115 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL);
2117 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2119 catchpacket(d, pkt, pktlen, slen,
2120 bpf_append_bytes, &bt);
2127 #define BPF_CHECK_DIRECTION(d, r, i) \
2128 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \
2129 ((d)->bd_direction == BPF_D_OUT && (r) == (i)))
2132 * Incoming linkage from device drivers, when packet is in an mbuf chain.
2133 * Locking model is explained in bpf_tap().
2136 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2146 /* Skip outgoing duplicate packets. */
2147 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2148 m->m_flags &= ~M_PROMISC;
2152 pktlen = m_length(m, NULL);
2153 gottime = BPF_TSTAMP_NONE;
2157 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2158 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2162 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2163 /* XXX We cannot handle multiple mbufs. */
2164 if (bf != NULL && m->m_next == NULL)
2165 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen);
2168 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
2173 if (gottime < bpf_ts_quality(d->bd_tstamp))
2174 gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2176 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2178 catchpacket(d, (u_char *)m, pktlen, slen,
2179 bpf_append_mbuf, &bt);
2187 * Incoming linkage from device drivers, when packet is in
2188 * an mbuf chain and to be prepended by a contiguous header.
2191 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
2199 /* Skip outgoing duplicate packets. */
2200 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2201 m->m_flags &= ~M_PROMISC;
2205 pktlen = m_length(m, NULL);
2207 * Craft on-stack mbuf suitable for passing to bpf_filter.
2208 * Note that we cut corners here; we only setup what's
2209 * absolutely needed--this mbuf should never go anywhere else.
2216 gottime = BPF_TSTAMP_NONE;
2220 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2221 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2224 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0);
2229 if (gottime < bpf_ts_quality(d->bd_tstamp))
2230 gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2232 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2234 catchpacket(d, (u_char *)&mb, pktlen, slen,
2235 bpf_append_mbuf, &bt);
2242 #undef BPF_CHECK_DIRECTION
2244 #undef BPF_TSTAMP_NONE
2245 #undef BPF_TSTAMP_FAST
2246 #undef BPF_TSTAMP_NORMAL
2247 #undef BPF_TSTAMP_EXTERN
2250 bpf_hdrlen(struct bpf_d *d)
2254 hdrlen = d->bd_bif->bif_hdrlen;
2255 #ifndef BURN_BRIDGES
2256 if (d->bd_tstamp == BPF_T_NONE ||
2257 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME)
2258 #ifdef COMPAT_FREEBSD32
2260 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32);
2263 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr);
2266 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr);
2267 #ifdef COMPAT_FREEBSD32
2269 hdrlen = BPF_WORDALIGN32(hdrlen);
2272 hdrlen = BPF_WORDALIGN(hdrlen);
2274 return (hdrlen - d->bd_bif->bif_hdrlen);
2278 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype)
2282 struct timespec tsn;
2284 if ((tstype & BPF_T_MONOTONIC) == 0) {
2286 bintime_add(&bt2, &boottimebin);
2289 switch (BPF_T_FORMAT(tstype)) {
2290 case BPF_T_MICROTIME:
2291 bintime2timeval(bt, &tsm);
2292 ts->bt_sec = tsm.tv_sec;
2293 ts->bt_frac = tsm.tv_usec;
2295 case BPF_T_NANOTIME:
2296 bintime2timespec(bt, &tsn);
2297 ts->bt_sec = tsn.tv_sec;
2298 ts->bt_frac = tsn.tv_nsec;
2301 ts->bt_sec = bt->sec;
2302 ts->bt_frac = bt->frac;
2308 * Move the packet data from interface memory (pkt) into the
2309 * store buffer. "cpfn" is the routine called to do the actual data
2310 * transfer. bcopy is passed in to copy contiguous chunks, while
2311 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case,
2312 * pkt is really an mbuf.
2315 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
2316 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int),
2319 struct bpf_xhdr hdr;
2320 #ifndef BURN_BRIDGES
2321 struct bpf_hdr hdr_old;
2322 #ifdef COMPAT_FREEBSD32
2323 struct bpf_hdr32 hdr32_old;
2326 int caplen, curlen, hdrlen, totlen;
2331 BPFD_LOCK_ASSERT(d);
2334 * Detect whether user space has released a buffer back to us, and if
2335 * so, move it from being a hold buffer to a free buffer. This may
2336 * not be the best place to do it (for example, we might only want to
2337 * run this check if we need the space), but for now it's a reliable
2340 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) {
2341 while (d->bd_hbuf_in_use)
2342 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2343 PRINET, "bd_hbuf", 0);
2344 d->bd_fbuf = d->bd_hbuf;
2347 bpf_buf_reclaimed(d);
2351 * Figure out how many bytes to move. If the packet is
2352 * greater or equal to the snapshot length, transfer that
2353 * much. Otherwise, transfer the whole packet (unless
2354 * we hit the buffer size limit).
2356 hdrlen = bpf_hdrlen(d);
2357 totlen = hdrlen + min(snaplen, pktlen);
2358 if (totlen > d->bd_bufsize)
2359 totlen = d->bd_bufsize;
2362 * Round up the end of the previous packet to the next longword.
2364 * Drop the packet if there's no room and no hope of room
2365 * If the packet would overflow the storage buffer or the storage
2366 * buffer is considered immutable by the buffer model, try to rotate
2367 * the buffer and wakeup pending processes.
2369 #ifdef COMPAT_FREEBSD32
2371 curlen = BPF_WORDALIGN32(d->bd_slen);
2374 curlen = BPF_WORDALIGN(d->bd_slen);
2375 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) {
2376 if (d->bd_fbuf == NULL) {
2378 * There's no room in the store buffer, and no
2379 * prospect of room, so drop the packet. Notify the
2386 while (d->bd_hbuf_in_use)
2387 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
2388 PRINET, "bd_hbuf", 0);
2392 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT)
2394 * Immediate mode is set, or the read timeout has already
2395 * expired during a select call. A packet arrived, so the
2396 * reader should be woken up.
2399 caplen = totlen - hdrlen;
2400 tstype = d->bd_tstamp;
2401 do_timestamp = tstype != BPF_T_NONE;
2402 #ifndef BURN_BRIDGES
2403 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) {
2406 bpf_bintime2ts(bt, &ts, tstype);
2407 #ifdef COMPAT_FREEBSD32
2408 if (d->bd_compat32) {
2409 bzero(&hdr32_old, sizeof(hdr32_old));
2411 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec;
2412 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac;
2414 hdr32_old.bh_datalen = pktlen;
2415 hdr32_old.bh_hdrlen = hdrlen;
2416 hdr32_old.bh_caplen = caplen;
2417 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old,
2422 bzero(&hdr_old, sizeof(hdr_old));
2424 hdr_old.bh_tstamp.tv_sec = ts.bt_sec;
2425 hdr_old.bh_tstamp.tv_usec = ts.bt_frac;
2427 hdr_old.bh_datalen = pktlen;
2428 hdr_old.bh_hdrlen = hdrlen;
2429 hdr_old.bh_caplen = caplen;
2430 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old,
2437 * Append the bpf header. Note we append the actual header size, but
2438 * move forward the length of the header plus padding.
2440 bzero(&hdr, sizeof(hdr));
2442 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype);
2443 hdr.bh_datalen = pktlen;
2444 hdr.bh_hdrlen = hdrlen;
2445 hdr.bh_caplen = caplen;
2446 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr));
2449 * Copy the packet data into the store buffer and update its length.
2451 #ifndef BURN_BRIDGES
2454 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen);
2455 d->bd_slen = curlen + totlen;
2462 * Free buffers currently in use by a descriptor.
2466 bpf_freed(struct bpf_d *d)
2470 * We don't need to lock out interrupts since this descriptor has
2471 * been detached from its interface and it yet hasn't been marked
2475 if (d->bd_rfilter != NULL) {
2476 free((caddr_t)d->bd_rfilter, M_BPF);
2478 if (d->bd_bfilter != NULL)
2479 bpf_destroy_jit_filter(d->bd_bfilter);
2482 if (d->bd_wfilter != NULL)
2483 free((caddr_t)d->bd_wfilter, M_BPF);
2484 mtx_destroy(&d->bd_lock);
2488 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the
2489 * fixed size of the link header (variable length headers not yet supported).
2492 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2495 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2499 * Attach an interface to bpf. ifp is a pointer to the structure
2500 * defining the interface to be attached, dlt is the link layer type,
2501 * and hdrlen is the fixed size of the link header (variable length
2502 * headers are not yet supporrted).
2505 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2509 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
2513 LIST_INIT(&bp->bif_dlist);
2514 LIST_INIT(&bp->bif_wlist);
2517 rw_init(&bp->bif_lock, "bpf interface lock");
2518 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
2522 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
2525 bp->bif_hdrlen = hdrlen;
2528 if_printf(ifp, "bpf attached\n");
2532 * Detach bpf from an interface. This involves detaching each descriptor
2533 * associated with the interface. Notify each descriptor as it's detached
2534 * so that any sleepers wake up and get ENXIO.
2537 bpfdetach(struct ifnet *ifp)
2539 struct bpf_if *bp, *bp_temp;
2546 /* Find all bpf_if struct's which reference ifp and detach them. */
2547 LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) {
2548 if (ifp != bp->bif_ifp)
2551 LIST_REMOVE(bp, bif_next);
2552 /* Add to to-be-freed list */
2553 LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next);
2557 * Delay freeing bp till interface is detached
2558 * and all routes through this interface are removed.
2559 * Mark bp as detached to restrict new consumers.
2562 bp->flags |= BPFIF_FLAG_DYING;
2565 CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p",
2566 __func__, bp->bif_dlt, bp, ifp);
2568 /* Free common descriptors */
2569 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
2570 bpf_detachd_locked(d);
2576 /* Free writer-only descriptors */
2577 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) {
2578 bpf_detachd_locked(d);
2588 printf("bpfdetach: %s was not attached\n", ifp->if_xname);
2593 * Interface departure handler.
2594 * Note departure event does not guarantee interface is going down.
2595 * Interface renaming is currently done via departure/arrival event set.
2597 * Departure handled is called after all routes pointing to
2598 * given interface are removed and interface is in down state
2599 * restricting any packets to be sent/received. We assume it is now safe
2600 * to free data allocated by BPF.
2603 bpf_ifdetach(void *arg __unused, struct ifnet *ifp)
2605 struct bpf_if *bp, *bp_temp;
2610 * Find matching entries in free list.
2611 * Nothing should be found if bpfdetach() was not called.
2613 LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) {
2614 if (ifp != bp->bif_ifp)
2617 CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p",
2620 LIST_REMOVE(bp, bif_next);
2622 rw_destroy(&bp->bif_lock);
2630 * Note that we cannot zero other pointers to
2631 * custom DLTs possibly used by given interface.
2638 * Get a list of available data link type of the interface.
2641 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
2649 ifp = d->bd_bif->bif_ifp;
2652 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2653 if (bp->bif_ifp != ifp)
2655 if (bfl->bfl_list != NULL) {
2656 if (n >= bfl->bfl_len)
2658 error = copyout(&bp->bif_dlt,
2659 bfl->bfl_list + n, sizeof(u_int));
2668 * Set the data link type of a BPF instance.
2671 bpf_setdlt(struct bpf_d *d, u_int dlt)
2673 int error, opromisc;
2679 if (d->bd_bif->bif_dlt == dlt)
2681 ifp = d->bd_bif->bif_ifp;
2683 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2684 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
2689 opromisc = d->bd_promisc;
2695 error = ifpromisc(bp->bif_ifp, 1);
2697 if_printf(bp->bif_ifp,
2698 "bpf_setdlt: ifpromisc failed (%d)\n",
2704 return (bp == NULL ? EINVAL : 0);
2708 bpf_drvinit(void *unused)
2712 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
2713 LIST_INIT(&bpf_iflist);
2714 LIST_INIT(&bpf_freelist);
2716 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf");
2717 /* For compatibility */
2718 make_dev_alias(dev, "bpf0");
2720 /* Register interface departure handler */
2721 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER(
2722 ifnet_departure_event, bpf_ifdetach, NULL,
2723 EVENTHANDLER_PRI_ANY);
2727 * Zero out the various packet counters associated with all of the bpf
2728 * descriptors. At some point, we will probably want to get a bit more
2729 * granular and allow the user to specify descriptors to be zeroed.
2732 bpf_zero_counters(void)
2738 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2740 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2756 * Fill filter statistics
2759 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
2762 bzero(d, sizeof(*d));
2763 BPFD_LOCK_ASSERT(bd);
2764 d->bd_structsize = sizeof(*d);
2765 /* XXX: reading should be protected by global lock */
2766 d->bd_immediate = bd->bd_immediate;
2767 d->bd_promisc = bd->bd_promisc;
2768 d->bd_hdrcmplt = bd->bd_hdrcmplt;
2769 d->bd_direction = bd->bd_direction;
2770 d->bd_feedback = bd->bd_feedback;
2771 d->bd_async = bd->bd_async;
2772 d->bd_rcount = bd->bd_rcount;
2773 d->bd_dcount = bd->bd_dcount;
2774 d->bd_fcount = bd->bd_fcount;
2775 d->bd_sig = bd->bd_sig;
2776 d->bd_slen = bd->bd_slen;
2777 d->bd_hlen = bd->bd_hlen;
2778 d->bd_bufsize = bd->bd_bufsize;
2779 d->bd_pid = bd->bd_pid;
2780 strlcpy(d->bd_ifname,
2781 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
2782 d->bd_locked = bd->bd_locked;
2783 d->bd_wcount = bd->bd_wcount;
2784 d->bd_wdcount = bd->bd_wdcount;
2785 d->bd_wfcount = bd->bd_wfcount;
2786 d->bd_zcopy = bd->bd_zcopy;
2787 d->bd_bufmode = bd->bd_bufmode;
2791 * Handle `netstat -B' stats request
2794 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS)
2796 static const struct xbpf_d zerostats;
2797 struct xbpf_d *xbdbuf, *xbd, tempstats;
2803 * XXX This is not technically correct. It is possible for non
2804 * privileged users to open bpf devices. It would make sense
2805 * if the users who opened the devices were able to retrieve
2806 * the statistics for them, too.
2808 error = priv_check(req->td, PRIV_NET_BPF);
2812 * Check to see if the user is requesting that the counters be
2813 * zeroed out. Explicitly check that the supplied data is zeroed,
2814 * as we aren't allowing the user to set the counters currently.
2816 if (req->newptr != NULL) {
2817 if (req->newlen != sizeof(tempstats))
2819 memset(&tempstats, 0, sizeof(tempstats));
2820 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats));
2823 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0)
2825 bpf_zero_counters();
2828 if (req->oldptr == NULL)
2829 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd)));
2830 if (bpf_bpfd_cnt == 0)
2831 return (SYSCTL_OUT(req, 0, 0));
2832 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK);
2834 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) {
2836 free(xbdbuf, M_BPF);
2840 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2842 /* Send writers-only first */
2843 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) {
2844 xbd = &xbdbuf[index++];
2846 bpfstats_fill_xbpf(xbd, bd);
2849 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2850 xbd = &xbdbuf[index++];
2852 bpfstats_fill_xbpf(xbd, bd);
2858 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd));
2859 free(xbdbuf, M_BPF);
2863 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL);
2865 #else /* !DEV_BPF && !NETGRAPH_BPF */
2867 * NOP stubs to allow bpf-using drivers to load and function.
2869 * A 'better' implementation would allow the core bpf functionality
2870 * to be loaded at runtime.
2872 static struct bpf_if bp_null;
2875 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2880 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2885 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m)
2890 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2893 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2897 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2900 *driverp = &bp_null;
2904 bpfdetach(struct ifnet *ifp)
2909 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
2911 return -1; /* "no filter" behaviour */
2915 bpf_validate(const struct bpf_insn *f, int len)
2917 return 0; /* false */
2920 #endif /* !DEV_BPF && !NETGRAPH_BPF */