FreeBSD/Linux Kernel Cross Reference
sys/net/bpf.c
1 /*-
2 * Copyright (c) 1990, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
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
8 * Berkeley Laboratory.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
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.
21 *
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
32 * SUCH DAMAGE.
33 *
34 * @(#)bpf.c 8.4 (Berkeley) 1/9/95
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/8.1/sys/net/bpf.c 207815 2010-05-09 12:36:51Z kib $");
39
40 #include "opt_bpf.h"
41 #include "opt_compat.h"
42 #include "opt_netgraph.h"
43
44 #include <sys/types.h>
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/conf.h>
48 #include <sys/fcntl.h>
49 #include <sys/jail.h>
50 #include <sys/malloc.h>
51 #include <sys/mbuf.h>
52 #include <sys/time.h>
53 #include <sys/priv.h>
54 #include <sys/proc.h>
55 #include <sys/signalvar.h>
56 #include <sys/filio.h>
57 #include <sys/sockio.h>
58 #include <sys/ttycom.h>
59 #include <sys/uio.h>
60
61 #include <sys/event.h>
62 #include <sys/file.h>
63 #include <sys/poll.h>
64 #include <sys/proc.h>
65
66 #include <sys/socket.h>
67
68 #include <net/if.h>
69 #include <net/bpf.h>
70 #include <net/bpf_buffer.h>
71 #ifdef BPF_JITTER
72 #include <net/bpf_jitter.h>
73 #endif
74 #include <net/bpf_zerocopy.h>
75 #include <net/bpfdesc.h>
76 #include <net/vnet.h>
77
78 #include <netinet/in.h>
79 #include <netinet/if_ether.h>
80 #include <sys/kernel.h>
81 #include <sys/sysctl.h>
82
83 #include <net80211/ieee80211_freebsd.h>
84
85 #include <security/mac/mac_framework.h>
86
87 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
88
89 #if defined(DEV_BPF) || defined(NETGRAPH_BPF)
90
91 #define PRINET 26 /* interruptible */
92
93 #ifdef COMPAT_FREEBSD32
94 #include <sys/mount.h>
95 #include <compat/freebsd32/freebsd32.h>
96 #define BPF_ALIGNMENT32 sizeof(int32_t)
97 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
98
99 /*
100 * 32-bit version of structure prepended to each packet. We use this header
101 * instead of the standard one for 32-bit streams. We mark the a stream as
102 * 32-bit the first time we see a 32-bit compat ioctl request.
103 */
104 struct bpf_hdr32 {
105 struct timeval32 bh_tstamp; /* time stamp */
106 uint32_t bh_caplen; /* length of captured portion */
107 uint32_t bh_datalen; /* original length of packet */
108 uint16_t bh_hdrlen; /* length of bpf header (this struct
109 plus alignment padding) */
110 };
111
112 struct bpf_program32 {
113 u_int bf_len;
114 uint32_t bf_insns;
115 };
116
117 struct bpf_dltlist32 {
118 u_int bfl_len;
119 u_int bfl_list;
120 };
121
122 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32)
123 #define BIOCSRTIMEOUT32 _IOW('B',109, struct timeval32)
124 #define BIOCGRTIMEOUT32 _IOR('B',110, struct timeval32)
125 #define BIOCGDLTLIST32 _IOWR('B',121, struct bpf_dltlist32)
126 #define BIOCSETWF32 _IOW('B',123, struct bpf_program32)
127 #define BIOCSETFNR32 _IOW('B',130, struct bpf_program32)
128 #endif
129
130 /*
131 * bpf_iflist is a list of BPF interface structures, each corresponding to a
132 * specific DLT. The same network interface might have several BPF interface
133 * structures registered by different layers in the stack (i.e., 802.11
134 * frames, ethernet frames, etc).
135 */
136 static LIST_HEAD(, bpf_if) bpf_iflist;
137 static struct mtx bpf_mtx; /* bpf global lock */
138 static int bpf_bpfd_cnt;
139
140 static void bpf_attachd(struct bpf_d *, struct bpf_if *);
141 static void bpf_detachd(struct bpf_d *);
142 static void bpf_freed(struct bpf_d *);
143 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **,
144 struct sockaddr *, int *, struct bpf_insn *);
145 static int bpf_setif(struct bpf_d *, struct ifreq *);
146 static void bpf_timed_out(void *);
147 static __inline void
148 bpf_wakeup(struct bpf_d *);
149 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
150 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int),
151 struct timeval *);
152 static void reset_d(struct bpf_d *);
153 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
154 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
155 static int bpf_setdlt(struct bpf_d *, u_int);
156 static void filt_bpfdetach(struct knote *);
157 static int filt_bpfread(struct knote *, long);
158 static void bpf_drvinit(void *);
159 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS);
160
161 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl");
162 int bpf_maxinsns = BPF_MAXINSNS;
163 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW,
164 &bpf_maxinsns, 0, "Maximum bpf program instructions");
165 static int bpf_zerocopy_enable = 0;
166 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW,
167 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions");
168 SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW,
169 bpf_stats_sysctl, "bpf statistics portal");
170
171 static d_open_t bpfopen;
172 static d_read_t bpfread;
173 static d_write_t bpfwrite;
174 static d_ioctl_t bpfioctl;
175 static d_poll_t bpfpoll;
176 static d_kqfilter_t bpfkqfilter;
177
178 static struct cdevsw bpf_cdevsw = {
179 .d_version = D_VERSION,
180 .d_open = bpfopen,
181 .d_read = bpfread,
182 .d_write = bpfwrite,
183 .d_ioctl = bpfioctl,
184 .d_poll = bpfpoll,
185 .d_name = "bpf",
186 .d_kqfilter = bpfkqfilter,
187 };
188
189 static struct filterops bpfread_filtops =
190 { 1, NULL, filt_bpfdetach, filt_bpfread };
191
192 /*
193 * Wrapper functions for various buffering methods. If the set of buffer
194 * modes expands, we will probably want to introduce a switch data structure
195 * similar to protosw, et.
196 */
197 static void
198 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
199 u_int len)
200 {
201
202 BPFD_LOCK_ASSERT(d);
203
204 switch (d->bd_bufmode) {
205 case BPF_BUFMODE_BUFFER:
206 return (bpf_buffer_append_bytes(d, buf, offset, src, len));
207
208 case BPF_BUFMODE_ZBUF:
209 d->bd_zcopy++;
210 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len));
211
212 default:
213 panic("bpf_buf_append_bytes");
214 }
215 }
216
217 static void
218 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
219 u_int len)
220 {
221
222 BPFD_LOCK_ASSERT(d);
223
224 switch (d->bd_bufmode) {
225 case BPF_BUFMODE_BUFFER:
226 return (bpf_buffer_append_mbuf(d, buf, offset, src, len));
227
228 case BPF_BUFMODE_ZBUF:
229 d->bd_zcopy++;
230 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len));
231
232 default:
233 panic("bpf_buf_append_mbuf");
234 }
235 }
236
237 /*
238 * This function gets called when the free buffer is re-assigned.
239 */
240 static void
241 bpf_buf_reclaimed(struct bpf_d *d)
242 {
243
244 BPFD_LOCK_ASSERT(d);
245
246 switch (d->bd_bufmode) {
247 case BPF_BUFMODE_BUFFER:
248 return;
249
250 case BPF_BUFMODE_ZBUF:
251 bpf_zerocopy_buf_reclaimed(d);
252 return;
253
254 default:
255 panic("bpf_buf_reclaimed");
256 }
257 }
258
259 /*
260 * If the buffer mechanism has a way to decide that a held buffer can be made
261 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is
262 * returned if the buffer can be discarded, (0) is returned if it cannot.
263 */
264 static int
265 bpf_canfreebuf(struct bpf_d *d)
266 {
267
268 BPFD_LOCK_ASSERT(d);
269
270 switch (d->bd_bufmode) {
271 case BPF_BUFMODE_ZBUF:
272 return (bpf_zerocopy_canfreebuf(d));
273 }
274 return (0);
275 }
276
277 /*
278 * Allow the buffer model to indicate that the current store buffer is
279 * immutable, regardless of the appearance of space. Return (1) if the
280 * buffer is writable, and (0) if not.
281 */
282 static int
283 bpf_canwritebuf(struct bpf_d *d)
284 {
285
286 BPFD_LOCK_ASSERT(d);
287
288 switch (d->bd_bufmode) {
289 case BPF_BUFMODE_ZBUF:
290 return (bpf_zerocopy_canwritebuf(d));
291 }
292 return (1);
293 }
294
295 /*
296 * Notify buffer model that an attempt to write to the store buffer has
297 * resulted in a dropped packet, in which case the buffer may be considered
298 * full.
299 */
300 static void
301 bpf_buffull(struct bpf_d *d)
302 {
303
304 BPFD_LOCK_ASSERT(d);
305
306 switch (d->bd_bufmode) {
307 case BPF_BUFMODE_ZBUF:
308 bpf_zerocopy_buffull(d);
309 break;
310 }
311 }
312
313 /*
314 * Notify the buffer model that a buffer has moved into the hold position.
315 */
316 void
317 bpf_bufheld(struct bpf_d *d)
318 {
319
320 BPFD_LOCK_ASSERT(d);
321
322 switch (d->bd_bufmode) {
323 case BPF_BUFMODE_ZBUF:
324 bpf_zerocopy_bufheld(d);
325 break;
326 }
327 }
328
329 static void
330 bpf_free(struct bpf_d *d)
331 {
332
333 switch (d->bd_bufmode) {
334 case BPF_BUFMODE_BUFFER:
335 return (bpf_buffer_free(d));
336
337 case BPF_BUFMODE_ZBUF:
338 return (bpf_zerocopy_free(d));
339
340 default:
341 panic("bpf_buf_free");
342 }
343 }
344
345 static int
346 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
347 {
348
349 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
350 return (EOPNOTSUPP);
351 return (bpf_buffer_uiomove(d, buf, len, uio));
352 }
353
354 static int
355 bpf_ioctl_sblen(struct bpf_d *d, u_int *i)
356 {
357
358 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
359 return (EOPNOTSUPP);
360 return (bpf_buffer_ioctl_sblen(d, i));
361 }
362
363 static int
364 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i)
365 {
366
367 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
368 return (EOPNOTSUPP);
369 return (bpf_zerocopy_ioctl_getzmax(td, d, i));
370 }
371
372 static int
373 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
374 {
375
376 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
377 return (EOPNOTSUPP);
378 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz));
379 }
380
381 static int
382 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
383 {
384
385 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
386 return (EOPNOTSUPP);
387 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz));
388 }
389
390 /*
391 * General BPF functions.
392 */
393 static int
394 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp,
395 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter)
396 {
397 const struct ieee80211_bpf_params *p;
398 struct ether_header *eh;
399 struct mbuf *m;
400 int error;
401 int len;
402 int hlen;
403 int slen;
404
405 /*
406 * Build a sockaddr based on the data link layer type.
407 * We do this at this level because the ethernet header
408 * is copied directly into the data field of the sockaddr.
409 * In the case of SLIP, there is no header and the packet
410 * is forwarded as is.
411 * Also, we are careful to leave room at the front of the mbuf
412 * for the link level header.
413 */
414 switch (linktype) {
415
416 case DLT_SLIP:
417 sockp->sa_family = AF_INET;
418 hlen = 0;
419 break;
420
421 case DLT_EN10MB:
422 sockp->sa_family = AF_UNSPEC;
423 /* XXX Would MAXLINKHDR be better? */
424 hlen = ETHER_HDR_LEN;
425 break;
426
427 case DLT_FDDI:
428 sockp->sa_family = AF_IMPLINK;
429 hlen = 0;
430 break;
431
432 case DLT_RAW:
433 sockp->sa_family = AF_UNSPEC;
434 hlen = 0;
435 break;
436
437 case DLT_NULL:
438 /*
439 * null interface types require a 4 byte pseudo header which
440 * corresponds to the address family of the packet.
441 */
442 sockp->sa_family = AF_UNSPEC;
443 hlen = 4;
444 break;
445
446 case DLT_ATM_RFC1483:
447 /*
448 * en atm driver requires 4-byte atm pseudo header.
449 * though it isn't standard, vpi:vci needs to be
450 * specified anyway.
451 */
452 sockp->sa_family = AF_UNSPEC;
453 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
454 break;
455
456 case DLT_PPP:
457 sockp->sa_family = AF_UNSPEC;
458 hlen = 4; /* This should match PPP_HDRLEN */
459 break;
460
461 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
462 sockp->sa_family = AF_IEEE80211;
463 hlen = 0;
464 break;
465
466 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
467 sockp->sa_family = AF_IEEE80211;
468 sockp->sa_len = 12; /* XXX != 0 */
469 hlen = sizeof(struct ieee80211_bpf_params);
470 break;
471
472 default:
473 return (EIO);
474 }
475
476 len = uio->uio_resid;
477
478 if (len - hlen > ifp->if_mtu)
479 return (EMSGSIZE);
480
481 if ((unsigned)len > MJUM16BYTES)
482 return (EIO);
483
484 if (len <= MHLEN)
485 MGETHDR(m, M_WAIT, MT_DATA);
486 else if (len <= MCLBYTES)
487 m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR);
488 else
489 m = m_getjcl(M_WAIT, MT_DATA, M_PKTHDR,
490 #if (MJUMPAGESIZE > MCLBYTES)
491 len <= MJUMPAGESIZE ? MJUMPAGESIZE :
492 #endif
493 (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES));
494 m->m_pkthdr.len = m->m_len = len;
495 m->m_pkthdr.rcvif = NULL;
496 *mp = m;
497
498 if (m->m_len < hlen) {
499 error = EPERM;
500 goto bad;
501 }
502
503 error = uiomove(mtod(m, u_char *), len, uio);
504 if (error)
505 goto bad;
506
507 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
508 if (slen == 0) {
509 error = EPERM;
510 goto bad;
511 }
512
513 /* Check for multicast destination */
514 switch (linktype) {
515 case DLT_EN10MB:
516 eh = mtod(m, struct ether_header *);
517 if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
518 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
519 ETHER_ADDR_LEN) == 0)
520 m->m_flags |= M_BCAST;
521 else
522 m->m_flags |= M_MCAST;
523 }
524 break;
525 }
526
527 /*
528 * Make room for link header, and copy it to sockaddr
529 */
530 if (hlen != 0) {
531 if (sockp->sa_family == AF_IEEE80211) {
532 /*
533 * Collect true length from the parameter header
534 * NB: sockp is known to be zero'd so if we do a
535 * short copy unspecified parameters will be
536 * zero.
537 * NB: packet may not be aligned after stripping
538 * bpf params
539 * XXX check ibp_vers
540 */
541 p = mtod(m, const struct ieee80211_bpf_params *);
542 hlen = p->ibp_len;
543 if (hlen > sizeof(sockp->sa_data)) {
544 error = EINVAL;
545 goto bad;
546 }
547 }
548 bcopy(m->m_data, sockp->sa_data, hlen);
549 }
550 *hdrlen = hlen;
551
552 return (0);
553 bad:
554 m_freem(m);
555 return (error);
556 }
557
558 /*
559 * Attach file to the bpf interface, i.e. make d listen on bp.
560 */
561 static void
562 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
563 {
564 /*
565 * Point d at bp, and add d to the interface's list of listeners.
566 * Finally, point the driver's bpf cookie at the interface so
567 * it will divert packets to bpf.
568 */
569 BPFIF_LOCK(bp);
570 d->bd_bif = bp;
571 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
572
573 bpf_bpfd_cnt++;
574 BPFIF_UNLOCK(bp);
575
576 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
577 }
578
579 /*
580 * Detach a file from its interface.
581 */
582 static void
583 bpf_detachd(struct bpf_d *d)
584 {
585 int error;
586 struct bpf_if *bp;
587 struct ifnet *ifp;
588
589 bp = d->bd_bif;
590 BPFIF_LOCK(bp);
591 BPFD_LOCK(d);
592 ifp = d->bd_bif->bif_ifp;
593
594 /*
595 * Remove d from the interface's descriptor list.
596 */
597 LIST_REMOVE(d, bd_next);
598
599 bpf_bpfd_cnt--;
600 d->bd_bif = NULL;
601 BPFD_UNLOCK(d);
602 BPFIF_UNLOCK(bp);
603
604 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
605
606 /*
607 * Check if this descriptor had requested promiscuous mode.
608 * If so, turn it off.
609 */
610 if (d->bd_promisc) {
611 d->bd_promisc = 0;
612 CURVNET_SET(ifp->if_vnet);
613 error = ifpromisc(ifp, 0);
614 CURVNET_RESTORE();
615 if (error != 0 && error != ENXIO) {
616 /*
617 * ENXIO can happen if a pccard is unplugged
618 * Something is really wrong if we were able to put
619 * the driver into promiscuous mode, but can't
620 * take it out.
621 */
622 if_printf(bp->bif_ifp,
623 "bpf_detach: ifpromisc failed (%d)\n", error);
624 }
625 }
626 }
627
628 /*
629 * Close the descriptor by detaching it from its interface,
630 * deallocating its buffers, and marking it free.
631 */
632 static void
633 bpf_dtor(void *data)
634 {
635 struct bpf_d *d = data;
636
637 BPFD_LOCK(d);
638 if (d->bd_state == BPF_WAITING)
639 callout_stop(&d->bd_callout);
640 d->bd_state = BPF_IDLE;
641 BPFD_UNLOCK(d);
642 funsetown(&d->bd_sigio);
643 mtx_lock(&bpf_mtx);
644 if (d->bd_bif)
645 bpf_detachd(d);
646 mtx_unlock(&bpf_mtx);
647 selwakeuppri(&d->bd_sel, PRINET);
648 #ifdef MAC
649 mac_bpfdesc_destroy(d);
650 #endif /* MAC */
651 knlist_destroy(&d->bd_sel.si_note);
652 callout_drain(&d->bd_callout);
653 bpf_freed(d);
654 free(d, M_BPF);
655 }
656
657 /*
658 * Open ethernet device. Returns ENXIO for illegal minor device number,
659 * EBUSY if file is open by another process.
660 */
661 /* ARGSUSED */
662 static int
663 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td)
664 {
665 struct bpf_d *d;
666 int error;
667
668 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
669 error = devfs_set_cdevpriv(d, bpf_dtor);
670 if (error != 0) {
671 free(d, M_BPF);
672 return (error);
673 }
674
675 /*
676 * For historical reasons, perform a one-time initialization call to
677 * the buffer routines, even though we're not yet committed to a
678 * particular buffer method.
679 */
680 bpf_buffer_init(d);
681 d->bd_bufmode = BPF_BUFMODE_BUFFER;
682 d->bd_sig = SIGIO;
683 d->bd_direction = BPF_D_INOUT;
684 d->bd_pid = td->td_proc->p_pid;
685 #ifdef MAC
686 mac_bpfdesc_init(d);
687 mac_bpfdesc_create(td->td_ucred, d);
688 #endif
689 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF);
690 callout_init_mtx(&d->bd_callout, &d->bd_mtx, 0);
691 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_mtx);
692
693 return (0);
694 }
695
696 /*
697 * bpfread - read next chunk of packets from buffers
698 */
699 static int
700 bpfread(struct cdev *dev, struct uio *uio, int ioflag)
701 {
702 struct bpf_d *d;
703 int error;
704 int non_block;
705 int timed_out;
706
707 error = devfs_get_cdevpriv((void **)&d);
708 if (error != 0)
709 return (error);
710
711 /*
712 * Restrict application to use a buffer the same size as
713 * as kernel buffers.
714 */
715 if (uio->uio_resid != d->bd_bufsize)
716 return (EINVAL);
717
718 non_block = ((ioflag & O_NONBLOCK) != 0);
719
720 BPFD_LOCK(d);
721 d->bd_pid = curthread->td_proc->p_pid;
722 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
723 BPFD_UNLOCK(d);
724 return (EOPNOTSUPP);
725 }
726 if (d->bd_state == BPF_WAITING)
727 callout_stop(&d->bd_callout);
728 timed_out = (d->bd_state == BPF_TIMED_OUT);
729 d->bd_state = BPF_IDLE;
730 /*
731 * If the hold buffer is empty, then do a timed sleep, which
732 * ends when the timeout expires or when enough packets
733 * have arrived to fill the store buffer.
734 */
735 while (d->bd_hbuf == NULL) {
736 if (d->bd_slen != 0) {
737 /*
738 * A packet(s) either arrived since the previous
739 * read or arrived while we were asleep.
740 */
741 if (d->bd_immediate || non_block || timed_out) {
742 /*
743 * Rotate the buffers and return what's here
744 * if we are in immediate mode, non-blocking
745 * flag is set, or this descriptor timed out.
746 */
747 ROTATE_BUFFERS(d);
748 break;
749 }
750 }
751
752 /*
753 * No data is available, check to see if the bpf device
754 * is still pointed at a real interface. If not, return
755 * ENXIO so that the userland process knows to rebind
756 * it before using it again.
757 */
758 if (d->bd_bif == NULL) {
759 BPFD_UNLOCK(d);
760 return (ENXIO);
761 }
762
763 if (non_block) {
764 BPFD_UNLOCK(d);
765 return (EWOULDBLOCK);
766 }
767 error = msleep(d, &d->bd_mtx, PRINET|PCATCH,
768 "bpf", d->bd_rtout);
769 if (error == EINTR || error == ERESTART) {
770 BPFD_UNLOCK(d);
771 return (error);
772 }
773 if (error == EWOULDBLOCK) {
774 /*
775 * On a timeout, return what's in the buffer,
776 * which may be nothing. If there is something
777 * in the store buffer, we can rotate the buffers.
778 */
779 if (d->bd_hbuf)
780 /*
781 * We filled up the buffer in between
782 * getting the timeout and arriving
783 * here, so we don't need to rotate.
784 */
785 break;
786
787 if (d->bd_slen == 0) {
788 BPFD_UNLOCK(d);
789 return (0);
790 }
791 ROTATE_BUFFERS(d);
792 break;
793 }
794 }
795 /*
796 * At this point, we know we have something in the hold slot.
797 */
798 BPFD_UNLOCK(d);
799
800 /*
801 * Move data from hold buffer into user space.
802 * We know the entire buffer is transferred since
803 * we checked above that the read buffer is bpf_bufsize bytes.
804 *
805 * XXXRW: More synchronization needed here: what if a second thread
806 * issues a read on the same fd at the same time? Don't want this
807 * getting invalidated.
808 */
809 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio);
810
811 BPFD_LOCK(d);
812 d->bd_fbuf = d->bd_hbuf;
813 d->bd_hbuf = NULL;
814 d->bd_hlen = 0;
815 bpf_buf_reclaimed(d);
816 BPFD_UNLOCK(d);
817
818 return (error);
819 }
820
821 /*
822 * If there are processes sleeping on this descriptor, wake them up.
823 */
824 static __inline void
825 bpf_wakeup(struct bpf_d *d)
826 {
827
828 BPFD_LOCK_ASSERT(d);
829 if (d->bd_state == BPF_WAITING) {
830 callout_stop(&d->bd_callout);
831 d->bd_state = BPF_IDLE;
832 }
833 wakeup(d);
834 if (d->bd_async && d->bd_sig && d->bd_sigio)
835 pgsigio(&d->bd_sigio, d->bd_sig, 0);
836
837 selwakeuppri(&d->bd_sel, PRINET);
838 KNOTE_LOCKED(&d->bd_sel.si_note, 0);
839 }
840
841 static void
842 bpf_timed_out(void *arg)
843 {
844 struct bpf_d *d = (struct bpf_d *)arg;
845
846 BPFD_LOCK_ASSERT(d);
847
848 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout))
849 return;
850 if (d->bd_state == BPF_WAITING) {
851 d->bd_state = BPF_TIMED_OUT;
852 if (d->bd_slen != 0)
853 bpf_wakeup(d);
854 }
855 }
856
857 static int
858 bpf_ready(struct bpf_d *d)
859 {
860
861 BPFD_LOCK_ASSERT(d);
862
863 if (!bpf_canfreebuf(d) && d->bd_hlen != 0)
864 return (1);
865 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
866 d->bd_slen != 0)
867 return (1);
868 return (0);
869 }
870
871 static int
872 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag)
873 {
874 struct bpf_d *d;
875 struct ifnet *ifp;
876 struct mbuf *m, *mc;
877 struct sockaddr dst;
878 int error, hlen;
879
880 error = devfs_get_cdevpriv((void **)&d);
881 if (error != 0)
882 return (error);
883
884 d->bd_pid = curthread->td_proc->p_pid;
885 d->bd_wcount++;
886 if (d->bd_bif == NULL) {
887 d->bd_wdcount++;
888 return (ENXIO);
889 }
890
891 ifp = d->bd_bif->bif_ifp;
892
893 if ((ifp->if_flags & IFF_UP) == 0) {
894 d->bd_wdcount++;
895 return (ENETDOWN);
896 }
897
898 if (uio->uio_resid == 0) {
899 d->bd_wdcount++;
900 return (0);
901 }
902
903 bzero(&dst, sizeof(dst));
904 m = NULL;
905 hlen = 0;
906 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp,
907 &m, &dst, &hlen, d->bd_wfilter);
908 if (error) {
909 d->bd_wdcount++;
910 return (error);
911 }
912 d->bd_wfcount++;
913 if (d->bd_hdrcmplt)
914 dst.sa_family = pseudo_AF_HDRCMPLT;
915
916 if (d->bd_feedback) {
917 mc = m_dup(m, M_DONTWAIT);
918 if (mc != NULL)
919 mc->m_pkthdr.rcvif = ifp;
920 /* Set M_PROMISC for outgoing packets to be discarded. */
921 if (d->bd_direction == BPF_D_INOUT)
922 m->m_flags |= M_PROMISC;
923 } else
924 mc = NULL;
925
926 m->m_pkthdr.len -= hlen;
927 m->m_len -= hlen;
928 m->m_data += hlen; /* XXX */
929
930 CURVNET_SET(ifp->if_vnet);
931 #ifdef MAC
932 BPFD_LOCK(d);
933 mac_bpfdesc_create_mbuf(d, m);
934 if (mc != NULL)
935 mac_bpfdesc_create_mbuf(d, mc);
936 BPFD_UNLOCK(d);
937 #endif
938
939 error = (*ifp->if_output)(ifp, m, &dst, NULL);
940 if (error)
941 d->bd_wdcount++;
942
943 if (mc != NULL) {
944 if (error == 0)
945 (*ifp->if_input)(ifp, mc);
946 else
947 m_freem(mc);
948 }
949 CURVNET_RESTORE();
950
951 return (error);
952 }
953
954 /*
955 * Reset a descriptor by flushing its packet buffer and clearing the receive
956 * and drop counts. This is doable for kernel-only buffers, but with
957 * zero-copy buffers, we can't write to (or rotate) buffers that are
958 * currently owned by userspace. It would be nice if we could encapsulate
959 * this logic in the buffer code rather than here.
960 */
961 static void
962 reset_d(struct bpf_d *d)
963 {
964
965 mtx_assert(&d->bd_mtx, MA_OWNED);
966
967 if ((d->bd_hbuf != NULL) &&
968 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) {
969 /* Free the hold buffer. */
970 d->bd_fbuf = d->bd_hbuf;
971 d->bd_hbuf = NULL;
972 d->bd_hlen = 0;
973 bpf_buf_reclaimed(d);
974 }
975 if (bpf_canwritebuf(d))
976 d->bd_slen = 0;
977 d->bd_rcount = 0;
978 d->bd_dcount = 0;
979 d->bd_fcount = 0;
980 d->bd_wcount = 0;
981 d->bd_wfcount = 0;
982 d->bd_wdcount = 0;
983 d->bd_zcopy = 0;
984 }
985
986 /*
987 * FIONREAD Check for read packet available.
988 * SIOCGIFADDR Get interface address - convenient hook to driver.
989 * BIOCGBLEN Get buffer len [for read()].
990 * BIOCSETF Set read filter.
991 * BIOCSETFNR Set read filter without resetting descriptor.
992 * BIOCSETWF Set write filter.
993 * BIOCFLUSH Flush read packet buffer.
994 * BIOCPROMISC Put interface into promiscuous mode.
995 * BIOCGDLT Get link layer type.
996 * BIOCGETIF Get interface name.
997 * BIOCSETIF Set interface.
998 * BIOCSRTIMEOUT Set read timeout.
999 * BIOCGRTIMEOUT Get read timeout.
1000 * BIOCGSTATS Get packet stats.
1001 * BIOCIMMEDIATE Set immediate mode.
1002 * BIOCVERSION Get filter language version.
1003 * BIOCGHDRCMPLT Get "header already complete" flag
1004 * BIOCSHDRCMPLT Set "header already complete" flag
1005 * BIOCGDIRECTION Get packet direction flag
1006 * BIOCSDIRECTION Set packet direction flag
1007 * BIOCLOCK Set "locked" flag
1008 * BIOCFEEDBACK Set packet feedback mode.
1009 * BIOCSETZBUF Set current zero-copy buffer locations.
1010 * BIOCGETZMAX Get maximum zero-copy buffer size.
1011 * BIOCROTZBUF Force rotation of zero-copy buffer
1012 * BIOCSETBUFMODE Set buffer mode.
1013 * BIOCGETBUFMODE Get current buffer mode.
1014 */
1015 /* ARGSUSED */
1016 static int
1017 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
1018 struct thread *td)
1019 {
1020 struct bpf_d *d;
1021 int error;
1022
1023 error = devfs_get_cdevpriv((void **)&d);
1024 if (error != 0)
1025 return (error);
1026
1027 /*
1028 * Refresh PID associated with this descriptor.
1029 */
1030 BPFD_LOCK(d);
1031 d->bd_pid = td->td_proc->p_pid;
1032 if (d->bd_state == BPF_WAITING)
1033 callout_stop(&d->bd_callout);
1034 d->bd_state = BPF_IDLE;
1035 BPFD_UNLOCK(d);
1036
1037 if (d->bd_locked == 1) {
1038 switch (cmd) {
1039 case BIOCGBLEN:
1040 case BIOCFLUSH:
1041 case BIOCGDLT:
1042 case BIOCGDLTLIST:
1043 #ifdef COMPAT_FREEBSD32
1044 case BIOCGDLTLIST32:
1045 #endif
1046 case BIOCGETIF:
1047 case BIOCGRTIMEOUT:
1048 #ifdef COMPAT_FREEBSD32
1049 case BIOCGRTIMEOUT32:
1050 #endif
1051 case BIOCGSTATS:
1052 case BIOCVERSION:
1053 case BIOCGRSIG:
1054 case BIOCGHDRCMPLT:
1055 case BIOCFEEDBACK:
1056 case FIONREAD:
1057 case BIOCLOCK:
1058 case BIOCSRTIMEOUT:
1059 #ifdef COMPAT_FREEBSD32
1060 case BIOCSRTIMEOUT32:
1061 #endif
1062 case BIOCIMMEDIATE:
1063 case TIOCGPGRP:
1064 case BIOCROTZBUF:
1065 break;
1066 default:
1067 return (EPERM);
1068 }
1069 }
1070 #ifdef COMPAT_FREEBSD32
1071 /*
1072 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so
1073 * that it will get 32-bit packet headers.
1074 */
1075 switch (cmd) {
1076 case BIOCSETF32:
1077 case BIOCSETFNR32:
1078 case BIOCSETWF32:
1079 case BIOCGDLTLIST32:
1080 case BIOCGRTIMEOUT32:
1081 case BIOCSRTIMEOUT32:
1082 d->bd_compat32 = 1;
1083 }
1084 #endif
1085
1086 CURVNET_SET(TD_TO_VNET(td));
1087 switch (cmd) {
1088
1089 default:
1090 error = EINVAL;
1091 break;
1092
1093 /*
1094 * Check for read packet available.
1095 */
1096 case FIONREAD:
1097 {
1098 int n;
1099
1100 BPFD_LOCK(d);
1101 n = d->bd_slen;
1102 if (d->bd_hbuf)
1103 n += d->bd_hlen;
1104 BPFD_UNLOCK(d);
1105
1106 *(int *)addr = n;
1107 break;
1108 }
1109
1110 case SIOCGIFADDR:
1111 {
1112 struct ifnet *ifp;
1113
1114 if (d->bd_bif == NULL)
1115 error = EINVAL;
1116 else {
1117 ifp = d->bd_bif->bif_ifp;
1118 error = (*ifp->if_ioctl)(ifp, cmd, addr);
1119 }
1120 break;
1121 }
1122
1123 /*
1124 * Get buffer len [for read()].
1125 */
1126 case BIOCGBLEN:
1127 *(u_int *)addr = d->bd_bufsize;
1128 break;
1129
1130 /*
1131 * Set buffer length.
1132 */
1133 case BIOCSBLEN:
1134 error = bpf_ioctl_sblen(d, (u_int *)addr);
1135 break;
1136
1137 /*
1138 * Set link layer read filter.
1139 */
1140 case BIOCSETF:
1141 case BIOCSETFNR:
1142 case BIOCSETWF:
1143 #ifdef COMPAT_FREEBSD32
1144 case BIOCSETF32:
1145 case BIOCSETFNR32:
1146 case BIOCSETWF32:
1147 #endif
1148 error = bpf_setf(d, (struct bpf_program *)addr, cmd);
1149 break;
1150
1151 /*
1152 * Flush read packet buffer.
1153 */
1154 case BIOCFLUSH:
1155 BPFD_LOCK(d);
1156 reset_d(d);
1157 BPFD_UNLOCK(d);
1158 break;
1159
1160 /*
1161 * Put interface into promiscuous mode.
1162 */
1163 case BIOCPROMISC:
1164 if (d->bd_bif == NULL) {
1165 /*
1166 * No interface attached yet.
1167 */
1168 error = EINVAL;
1169 break;
1170 }
1171 if (d->bd_promisc == 0) {
1172 error = ifpromisc(d->bd_bif->bif_ifp, 1);
1173 if (error == 0)
1174 d->bd_promisc = 1;
1175 }
1176 break;
1177
1178 /*
1179 * Get current data link type.
1180 */
1181 case BIOCGDLT:
1182 if (d->bd_bif == NULL)
1183 error = EINVAL;
1184 else
1185 *(u_int *)addr = d->bd_bif->bif_dlt;
1186 break;
1187
1188 /*
1189 * Get a list of supported data link types.
1190 */
1191 #ifdef COMPAT_FREEBSD32
1192 case BIOCGDLTLIST32:
1193 {
1194 struct bpf_dltlist32 *list32;
1195 struct bpf_dltlist dltlist;
1196
1197 list32 = (struct bpf_dltlist32 *)addr;
1198 dltlist.bfl_len = list32->bfl_len;
1199 dltlist.bfl_list = PTRIN(list32->bfl_list);
1200 if (d->bd_bif == NULL)
1201 error = EINVAL;
1202 else {
1203 error = bpf_getdltlist(d, &dltlist);
1204 if (error == 0)
1205 list32->bfl_len = dltlist.bfl_len;
1206 }
1207 break;
1208 }
1209 #endif
1210
1211 case BIOCGDLTLIST:
1212 if (d->bd_bif == NULL)
1213 error = EINVAL;
1214 else
1215 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
1216 break;
1217
1218 /*
1219 * Set data link type.
1220 */
1221 case BIOCSDLT:
1222 if (d->bd_bif == NULL)
1223 error = EINVAL;
1224 else
1225 error = bpf_setdlt(d, *(u_int *)addr);
1226 break;
1227
1228 /*
1229 * Get interface name.
1230 */
1231 case BIOCGETIF:
1232 if (d->bd_bif == NULL)
1233 error = EINVAL;
1234 else {
1235 struct ifnet *const ifp = d->bd_bif->bif_ifp;
1236 struct ifreq *const ifr = (struct ifreq *)addr;
1237
1238 strlcpy(ifr->ifr_name, ifp->if_xname,
1239 sizeof(ifr->ifr_name));
1240 }
1241 break;
1242
1243 /*
1244 * Set interface.
1245 */
1246 case BIOCSETIF:
1247 error = bpf_setif(d, (struct ifreq *)addr);
1248 break;
1249
1250 /*
1251 * Set read timeout.
1252 */
1253 case BIOCSRTIMEOUT:
1254 #ifdef COMPAT_FREEBSD32
1255 case BIOCSRTIMEOUT32:
1256 #endif
1257 {
1258 struct timeval *tv = (struct timeval *)addr;
1259 #ifdef COMPAT_FREEBSD32
1260 struct timeval32 *tv32;
1261 struct timeval tv64;
1262
1263 if (cmd == BIOCSRTIMEOUT32) {
1264 tv32 = (struct timeval32 *)addr;
1265 tv = &tv64;
1266 tv->tv_sec = tv32->tv_sec;
1267 tv->tv_usec = tv32->tv_usec;
1268 } else
1269 #endif
1270 tv = (struct timeval *)addr;
1271
1272 /*
1273 * Subtract 1 tick from tvtohz() since this isn't
1274 * a one-shot timer.
1275 */
1276 if ((error = itimerfix(tv)) == 0)
1277 d->bd_rtout = tvtohz(tv) - 1;
1278 break;
1279 }
1280
1281 /*
1282 * Get read timeout.
1283 */
1284 case BIOCGRTIMEOUT:
1285 #ifdef COMPAT_FREEBSD32
1286 case BIOCGRTIMEOUT32:
1287 #endif
1288 {
1289 struct timeval *tv;
1290 #ifdef COMPAT_FREEBSD32
1291 struct timeval32 *tv32;
1292 struct timeval tv64;
1293
1294 if (cmd == BIOCGRTIMEOUT32)
1295 tv = &tv64;
1296 else
1297 #endif
1298 tv = (struct timeval *)addr;
1299
1300 tv->tv_sec = d->bd_rtout / hz;
1301 tv->tv_usec = (d->bd_rtout % hz) * tick;
1302 #ifdef COMPAT_FREEBSD32
1303 if (cmd == BIOCGRTIMEOUT32) {
1304 tv32 = (struct timeval32 *)addr;
1305 tv32->tv_sec = tv->tv_sec;
1306 tv32->tv_usec = tv->tv_usec;
1307 }
1308 #endif
1309
1310 break;
1311 }
1312
1313 /*
1314 * Get packet stats.
1315 */
1316 case BIOCGSTATS:
1317 {
1318 struct bpf_stat *bs = (struct bpf_stat *)addr;
1319
1320 /* XXXCSJP overflow */
1321 bs->bs_recv = d->bd_rcount;
1322 bs->bs_drop = d->bd_dcount;
1323 break;
1324 }
1325
1326 /*
1327 * Set immediate mode.
1328 */
1329 case BIOCIMMEDIATE:
1330 d->bd_immediate = *(u_int *)addr;
1331 break;
1332
1333 case BIOCVERSION:
1334 {
1335 struct bpf_version *bv = (struct bpf_version *)addr;
1336
1337 bv->bv_major = BPF_MAJOR_VERSION;
1338 bv->bv_minor = BPF_MINOR_VERSION;
1339 break;
1340 }
1341
1342 /*
1343 * Get "header already complete" flag
1344 */
1345 case BIOCGHDRCMPLT:
1346 *(u_int *)addr = d->bd_hdrcmplt;
1347 break;
1348
1349 /*
1350 * Set "header already complete" flag
1351 */
1352 case BIOCSHDRCMPLT:
1353 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
1354 break;
1355
1356 /*
1357 * Get packet direction flag
1358 */
1359 case BIOCGDIRECTION:
1360 *(u_int *)addr = d->bd_direction;
1361 break;
1362
1363 /*
1364 * Set packet direction flag
1365 */
1366 case BIOCSDIRECTION:
1367 {
1368 u_int direction;
1369
1370 direction = *(u_int *)addr;
1371 switch (direction) {
1372 case BPF_D_IN:
1373 case BPF_D_INOUT:
1374 case BPF_D_OUT:
1375 d->bd_direction = direction;
1376 break;
1377 default:
1378 error = EINVAL;
1379 }
1380 }
1381 break;
1382
1383 case BIOCFEEDBACK:
1384 d->bd_feedback = *(u_int *)addr;
1385 break;
1386
1387 case BIOCLOCK:
1388 d->bd_locked = 1;
1389 break;
1390
1391 case FIONBIO: /* Non-blocking I/O */
1392 break;
1393
1394 case FIOASYNC: /* Send signal on receive packets */
1395 d->bd_async = *(int *)addr;
1396 break;
1397
1398 case FIOSETOWN:
1399 error = fsetown(*(int *)addr, &d->bd_sigio);
1400 break;
1401
1402 case FIOGETOWN:
1403 *(int *)addr = fgetown(&d->bd_sigio);
1404 break;
1405
1406 /* This is deprecated, FIOSETOWN should be used instead. */
1407 case TIOCSPGRP:
1408 error = fsetown(-(*(int *)addr), &d->bd_sigio);
1409 break;
1410
1411 /* This is deprecated, FIOGETOWN should be used instead. */
1412 case TIOCGPGRP:
1413 *(int *)addr = -fgetown(&d->bd_sigio);
1414 break;
1415
1416 case BIOCSRSIG: /* Set receive signal */
1417 {
1418 u_int sig;
1419
1420 sig = *(u_int *)addr;
1421
1422 if (sig >= NSIG)
1423 error = EINVAL;
1424 else
1425 d->bd_sig = sig;
1426 break;
1427 }
1428 case BIOCGRSIG:
1429 *(u_int *)addr = d->bd_sig;
1430 break;
1431
1432 case BIOCGETBUFMODE:
1433 *(u_int *)addr = d->bd_bufmode;
1434 break;
1435
1436 case BIOCSETBUFMODE:
1437 /*
1438 * Allow the buffering mode to be changed as long as we
1439 * haven't yet committed to a particular mode. Our
1440 * definition of commitment, for now, is whether or not a
1441 * buffer has been allocated or an interface attached, since
1442 * that's the point where things get tricky.
1443 */
1444 switch (*(u_int *)addr) {
1445 case BPF_BUFMODE_BUFFER:
1446 break;
1447
1448 case BPF_BUFMODE_ZBUF:
1449 if (bpf_zerocopy_enable)
1450 break;
1451 /* FALLSTHROUGH */
1452
1453 default:
1454 CURVNET_RESTORE();
1455 return (EINVAL);
1456 }
1457
1458 BPFD_LOCK(d);
1459 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL ||
1460 d->bd_fbuf != NULL || d->bd_bif != NULL) {
1461 BPFD_UNLOCK(d);
1462 CURVNET_RESTORE();
1463 return (EBUSY);
1464 }
1465 d->bd_bufmode = *(u_int *)addr;
1466 BPFD_UNLOCK(d);
1467 break;
1468
1469 case BIOCGETZMAX:
1470 error = bpf_ioctl_getzmax(td, d, (size_t *)addr);
1471 break;
1472
1473 case BIOCSETZBUF:
1474 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr);
1475 break;
1476
1477 case BIOCROTZBUF:
1478 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr);
1479 break;
1480 }
1481 CURVNET_RESTORE();
1482 return (error);
1483 }
1484
1485 /*
1486 * Set d's packet filter program to fp. If this file already has a filter,
1487 * free it and replace it. Returns EINVAL for bogus requests.
1488 */
1489 static int
1490 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1491 {
1492 struct bpf_insn *fcode, *old;
1493 u_int wfilter, flen, size;
1494 #ifdef BPF_JITTER
1495 bpf_jit_filter *ofunc;
1496 #endif
1497 #ifdef COMPAT_FREEBSD32
1498 struct bpf_program32 *fp32;
1499 struct bpf_program fp_swab;
1500
1501 if (cmd == BIOCSETWF32 || cmd == BIOCSETF32 || cmd == BIOCSETFNR32) {
1502 fp32 = (struct bpf_program32 *)fp;
1503 fp_swab.bf_len = fp32->bf_len;
1504 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns;
1505 fp = &fp_swab;
1506 if (cmd == BIOCSETWF32)
1507 cmd = BIOCSETWF;
1508 }
1509 #endif
1510 if (cmd == BIOCSETWF) {
1511 old = d->bd_wfilter;
1512 wfilter = 1;
1513 #ifdef BPF_JITTER
1514 ofunc = NULL;
1515 #endif
1516 } else {
1517 wfilter = 0;
1518 old = d->bd_rfilter;
1519 #ifdef BPF_JITTER
1520 ofunc = d->bd_bfilter;
1521 #endif
1522 }
1523 if (fp->bf_insns == NULL) {
1524 if (fp->bf_len != 0)
1525 return (EINVAL);
1526 BPFD_LOCK(d);
1527 if (wfilter)
1528 d->bd_wfilter = NULL;
1529 else {
1530 d->bd_rfilter = NULL;
1531 #ifdef BPF_JITTER
1532 d->bd_bfilter = NULL;
1533 #endif
1534 if (cmd == BIOCSETF)
1535 reset_d(d);
1536 }
1537 BPFD_UNLOCK(d);
1538 if (old != NULL)
1539 free((caddr_t)old, M_BPF);
1540 #ifdef BPF_JITTER
1541 if (ofunc != NULL)
1542 bpf_destroy_jit_filter(ofunc);
1543 #endif
1544 return (0);
1545 }
1546 flen = fp->bf_len;
1547 if (flen > bpf_maxinsns)
1548 return (EINVAL);
1549
1550 size = flen * sizeof(*fp->bf_insns);
1551 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK);
1552 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 &&
1553 bpf_validate(fcode, (int)flen)) {
1554 BPFD_LOCK(d);
1555 if (wfilter)
1556 d->bd_wfilter = fcode;
1557 else {
1558 d->bd_rfilter = fcode;
1559 #ifdef BPF_JITTER
1560 d->bd_bfilter = bpf_jitter(fcode, flen);
1561 #endif
1562 if (cmd == BIOCSETF)
1563 reset_d(d);
1564 }
1565 BPFD_UNLOCK(d);
1566 if (old != NULL)
1567 free((caddr_t)old, M_BPF);
1568 #ifdef BPF_JITTER
1569 if (ofunc != NULL)
1570 bpf_destroy_jit_filter(ofunc);
1571 #endif
1572
1573 return (0);
1574 }
1575 free((caddr_t)fcode, M_BPF);
1576 return (EINVAL);
1577 }
1578
1579 /*
1580 * Detach a file from its current interface (if attached at all) and attach
1581 * to the interface indicated by the name stored in ifr.
1582 * Return an errno or 0.
1583 */
1584 static int
1585 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1586 {
1587 struct bpf_if *bp;
1588 struct ifnet *theywant;
1589
1590 theywant = ifunit(ifr->ifr_name);
1591 if (theywant == NULL || theywant->if_bpf == NULL)
1592 return (ENXIO);
1593
1594 bp = theywant->if_bpf;
1595
1596 /*
1597 * Behavior here depends on the buffering model. If we're using
1598 * kernel memory buffers, then we can allocate them here. If we're
1599 * using zero-copy, then the user process must have registered
1600 * buffers by the time we get here. If not, return an error.
1601 *
1602 * XXXRW: There are locking issues here with multi-threaded use: what
1603 * if two threads try to set the interface at once?
1604 */
1605 switch (d->bd_bufmode) {
1606 case BPF_BUFMODE_BUFFER:
1607 if (d->bd_sbuf == NULL)
1608 bpf_buffer_alloc(d);
1609 KASSERT(d->bd_sbuf != NULL, ("bpf_setif: bd_sbuf NULL"));
1610 break;
1611
1612 case BPF_BUFMODE_ZBUF:
1613 if (d->bd_sbuf == NULL)
1614 return (EINVAL);
1615 break;
1616
1617 default:
1618 panic("bpf_setif: bufmode %d", d->bd_bufmode);
1619 }
1620 if (bp != d->bd_bif) {
1621 if (d->bd_bif)
1622 /*
1623 * Detach if attached to something else.
1624 */
1625 bpf_detachd(d);
1626
1627 bpf_attachd(d, bp);
1628 }
1629 BPFD_LOCK(d);
1630 reset_d(d);
1631 BPFD_UNLOCK(d);
1632 return (0);
1633 }
1634
1635 /*
1636 * Support for select() and poll() system calls
1637 *
1638 * Return true iff the specific operation will not block indefinitely.
1639 * Otherwise, return false but make a note that a selwakeup() must be done.
1640 */
1641 static int
1642 bpfpoll(struct cdev *dev, int events, struct thread *td)
1643 {
1644 struct bpf_d *d;
1645 int revents;
1646
1647 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL)
1648 return (events &
1649 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
1650
1651 /*
1652 * Refresh PID associated with this descriptor.
1653 */
1654 revents = events & (POLLOUT | POLLWRNORM);
1655 BPFD_LOCK(d);
1656 d->bd_pid = td->td_proc->p_pid;
1657 if (events & (POLLIN | POLLRDNORM)) {
1658 if (bpf_ready(d))
1659 revents |= events & (POLLIN | POLLRDNORM);
1660 else {
1661 selrecord(td, &d->bd_sel);
1662 /* Start the read timeout if necessary. */
1663 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1664 callout_reset(&d->bd_callout, d->bd_rtout,
1665 bpf_timed_out, d);
1666 d->bd_state = BPF_WAITING;
1667 }
1668 }
1669 }
1670 BPFD_UNLOCK(d);
1671 return (revents);
1672 }
1673
1674 /*
1675 * Support for kevent() system call. Register EVFILT_READ filters and
1676 * reject all others.
1677 */
1678 int
1679 bpfkqfilter(struct cdev *dev, struct knote *kn)
1680 {
1681 struct bpf_d *d;
1682
1683 if (devfs_get_cdevpriv((void **)&d) != 0 ||
1684 kn->kn_filter != EVFILT_READ)
1685 return (1);
1686
1687 /*
1688 * Refresh PID associated with this descriptor.
1689 */
1690 BPFD_LOCK(d);
1691 d->bd_pid = curthread->td_proc->p_pid;
1692 kn->kn_fop = &bpfread_filtops;
1693 kn->kn_hook = d;
1694 knlist_add(&d->bd_sel.si_note, kn, 1);
1695 BPFD_UNLOCK(d);
1696
1697 return (0);
1698 }
1699
1700 static void
1701 filt_bpfdetach(struct knote *kn)
1702 {
1703 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
1704
1705 knlist_remove(&d->bd_sel.si_note, kn, 0);
1706 }
1707
1708 static int
1709 filt_bpfread(struct knote *kn, long hint)
1710 {
1711 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
1712 int ready;
1713
1714 BPFD_LOCK_ASSERT(d);
1715 ready = bpf_ready(d);
1716 if (ready) {
1717 kn->kn_data = d->bd_slen;
1718 if (d->bd_hbuf)
1719 kn->kn_data += d->bd_hlen;
1720 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1721 callout_reset(&d->bd_callout, d->bd_rtout,
1722 bpf_timed_out, d);
1723 d->bd_state = BPF_WAITING;
1724 }
1725
1726 return (ready);
1727 }
1728
1729 /*
1730 * Incoming linkage from device drivers. Process the packet pkt, of length
1731 * pktlen, which is stored in a contiguous buffer. The packet is parsed
1732 * by each process' filter, and if accepted, stashed into the corresponding
1733 * buffer.
1734 */
1735 void
1736 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1737 {
1738 struct bpf_d *d;
1739 #ifdef BPF_JITTER
1740 bpf_jit_filter *bf;
1741 #endif
1742 u_int slen;
1743 int gottime;
1744 struct timeval tv;
1745
1746 gottime = 0;
1747 BPFIF_LOCK(bp);
1748 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1749 BPFD_LOCK(d);
1750 ++d->bd_rcount;
1751 /*
1752 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no
1753 * way for the caller to indiciate to us whether this packet
1754 * is inbound or outbound. In the bpf_mtap() routines, we use
1755 * the interface pointers on the mbuf to figure it out.
1756 */
1757 #ifdef BPF_JITTER
1758 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
1759 if (bf != NULL)
1760 slen = (*(bf->func))(pkt, pktlen, pktlen);
1761 else
1762 #endif
1763 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1764 if (slen != 0) {
1765 d->bd_fcount++;
1766 if (!gottime) {
1767 microtime(&tv);
1768 gottime = 1;
1769 }
1770 #ifdef MAC
1771 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
1772 #endif
1773 catchpacket(d, pkt, pktlen, slen,
1774 bpf_append_bytes, &tv);
1775 }
1776 BPFD_UNLOCK(d);
1777 }
1778 BPFIF_UNLOCK(bp);
1779 }
1780
1781 #define BPF_CHECK_DIRECTION(d, r, i) \
1782 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \
1783 ((d)->bd_direction == BPF_D_OUT && (r) == (i)))
1784
1785 /*
1786 * Incoming linkage from device drivers, when packet is in an mbuf chain.
1787 */
1788 void
1789 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1790 {
1791 struct bpf_d *d;
1792 #ifdef BPF_JITTER
1793 bpf_jit_filter *bf;
1794 #endif
1795 u_int pktlen, slen;
1796 int gottime;
1797 struct timeval tv;
1798
1799 /* Skip outgoing duplicate packets. */
1800 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
1801 m->m_flags &= ~M_PROMISC;
1802 return;
1803 }
1804
1805 gottime = 0;
1806
1807 pktlen = m_length(m, NULL);
1808
1809 BPFIF_LOCK(bp);
1810 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1811 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
1812 continue;
1813 BPFD_LOCK(d);
1814 ++d->bd_rcount;
1815 #ifdef BPF_JITTER
1816 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
1817 /* XXX We cannot handle multiple mbufs. */
1818 if (bf != NULL && m->m_next == NULL)
1819 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen);
1820 else
1821 #endif
1822 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1823 if (slen != 0) {
1824 d->bd_fcount++;
1825 if (!gottime) {
1826 microtime(&tv);
1827 gottime = 1;
1828 }
1829 #ifdef MAC
1830 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
1831 #endif
1832 catchpacket(d, (u_char *)m, pktlen, slen,
1833 bpf_append_mbuf, &tv);
1834 }
1835 BPFD_UNLOCK(d);
1836 }
1837 BPFIF_UNLOCK(bp);
1838 }
1839
1840 /*
1841 * Incoming linkage from device drivers, when packet is in
1842 * an mbuf chain and to be prepended by a contiguous header.
1843 */
1844 void
1845 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
1846 {
1847 struct mbuf mb;
1848 struct bpf_d *d;
1849 u_int pktlen, slen;
1850 int gottime;
1851 struct timeval tv;
1852
1853 /* Skip outgoing duplicate packets. */
1854 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
1855 m->m_flags &= ~M_PROMISC;
1856 return;
1857 }
1858
1859 gottime = 0;
1860
1861 pktlen = m_length(m, NULL);
1862 /*
1863 * Craft on-stack mbuf suitable for passing to bpf_filter.
1864 * Note that we cut corners here; we only setup what's
1865 * absolutely needed--this mbuf should never go anywhere else.
1866 */
1867 mb.m_next = m;
1868 mb.m_data = data;
1869 mb.m_len = dlen;
1870 pktlen += dlen;
1871
1872 BPFIF_LOCK(bp);
1873 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1874 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
1875 continue;
1876 BPFD_LOCK(d);
1877 ++d->bd_rcount;
1878 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0);
1879 if (slen != 0) {
1880 d->bd_fcount++;
1881 if (!gottime) {
1882 microtime(&tv);
1883 gottime = 1;
1884 }
1885 #ifdef MAC
1886 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
1887 #endif
1888 catchpacket(d, (u_char *)&mb, pktlen, slen,
1889 bpf_append_mbuf, &tv);
1890 }
1891 BPFD_UNLOCK(d);
1892 }
1893 BPFIF_UNLOCK(bp);
1894 }
1895
1896 #undef BPF_CHECK_DIRECTION
1897
1898 /*
1899 * Move the packet data from interface memory (pkt) into the
1900 * store buffer. "cpfn" is the routine called to do the actual data
1901 * transfer. bcopy is passed in to copy contiguous chunks, while
1902 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case,
1903 * pkt is really an mbuf.
1904 */
1905 static void
1906 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1907 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int),
1908 struct timeval *tv)
1909 {
1910 struct bpf_hdr hdr;
1911 #ifdef COMPAT_FREEBSD32
1912 struct bpf_hdr32 hdr32;
1913 #endif
1914 int totlen, curlen;
1915 int hdrlen = d->bd_bif->bif_hdrlen;
1916 int do_wakeup = 0;
1917
1918 BPFD_LOCK_ASSERT(d);
1919
1920 /*
1921 * Detect whether user space has released a buffer back to us, and if
1922 * so, move it from being a hold buffer to a free buffer. This may
1923 * not be the best place to do it (for example, we might only want to
1924 * run this check if we need the space), but for now it's a reliable
1925 * spot to do it.
1926 */
1927 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) {
1928 d->bd_fbuf = d->bd_hbuf;
1929 d->bd_hbuf = NULL;
1930 d->bd_hlen = 0;
1931 bpf_buf_reclaimed(d);
1932 }
1933
1934 /*
1935 * Figure out how many bytes to move. If the packet is
1936 * greater or equal to the snapshot length, transfer that
1937 * much. Otherwise, transfer the whole packet (unless
1938 * we hit the buffer size limit).
1939 */
1940 totlen = hdrlen + min(snaplen, pktlen);
1941 if (totlen > d->bd_bufsize)
1942 totlen = d->bd_bufsize;
1943
1944 /*
1945 * Round up the end of the previous packet to the next longword.
1946 *
1947 * Drop the packet if there's no room and no hope of room
1948 * If the packet would overflow the storage buffer or the storage
1949 * buffer is considered immutable by the buffer model, try to rotate
1950 * the buffer and wakeup pending processes.
1951 */
1952 #ifdef COMPAT_FREEBSD32
1953 if (d->bd_compat32)
1954 curlen = BPF_WORDALIGN32(d->bd_slen);
1955 else
1956 #endif
1957 curlen = BPF_WORDALIGN(d->bd_slen);
1958 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) {
1959 if (d->bd_fbuf == NULL) {
1960 /*
1961 * There's no room in the store buffer, and no
1962 * prospect of room, so drop the packet. Notify the
1963 * buffer model.
1964 */
1965 bpf_buffull(d);
1966 ++d->bd_dcount;
1967 return;
1968 }
1969 ROTATE_BUFFERS(d);
1970 do_wakeup = 1;
1971 curlen = 0;
1972 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT)
1973 /*
1974 * Immediate mode is set, or the read timeout has already
1975 * expired during a select call. A packet arrived, so the
1976 * reader should be woken up.
1977 */
1978 do_wakeup = 1;
1979 #ifdef COMPAT_FREEBSD32
1980 /*
1981 * If this is a 32-bit stream, then stick a 32-bit header at the
1982 * front and copy the data into the buffer.
1983 */
1984 if (d->bd_compat32) {
1985 bzero(&hdr32, sizeof(hdr32));
1986 hdr32.bh_tstamp.tv_sec = tv->tv_sec;
1987 hdr32.bh_tstamp.tv_usec = tv->tv_usec;
1988 hdr32.bh_datalen = pktlen;
1989 hdr32.bh_hdrlen = hdrlen;
1990 hdr.bh_caplen = hdr32.bh_caplen = totlen - hdrlen;
1991 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32, sizeof(hdr32));
1992 goto copy;
1993 }
1994 #endif
1995
1996 /*
1997 * Append the bpf header. Note we append the actual header size, but
1998 * move forward the length of the header plus padding.
1999 */
2000 bzero(&hdr, sizeof(hdr));
2001 hdr.bh_tstamp = *tv;
2002 hdr.bh_datalen = pktlen;
2003 hdr.bh_hdrlen = hdrlen;
2004 hdr.bh_caplen = totlen - hdrlen;
2005 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr));
2006
2007 /*
2008 * Copy the packet data into the store buffer and update its length.
2009 */
2010 #ifdef COMPAT_FREEBSD32
2011 copy:
2012 #endif
2013 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, hdr.bh_caplen);
2014 d->bd_slen = curlen + totlen;
2015
2016 if (do_wakeup)
2017 bpf_wakeup(d);
2018 }
2019
2020 /*
2021 * Free buffers currently in use by a descriptor.
2022 * Called on close.
2023 */
2024 static void
2025 bpf_freed(struct bpf_d *d)
2026 {
2027
2028 /*
2029 * We don't need to lock out interrupts since this descriptor has
2030 * been detached from its interface and it yet hasn't been marked
2031 * free.
2032 */
2033 bpf_free(d);
2034 if (d->bd_rfilter != NULL) {
2035 free((caddr_t)d->bd_rfilter, M_BPF);
2036 #ifdef BPF_JITTER
2037 if (d->bd_bfilter != NULL)
2038 bpf_destroy_jit_filter(d->bd_bfilter);
2039 #endif
2040 }
2041 if (d->bd_wfilter != NULL)
2042 free((caddr_t)d->bd_wfilter, M_BPF);
2043 mtx_destroy(&d->bd_mtx);
2044 }
2045
2046 /*
2047 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the
2048 * fixed size of the link header (variable length headers not yet supported).
2049 */
2050 void
2051 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2052 {
2053
2054 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2055 }
2056
2057 /*
2058 * Attach an interface to bpf. ifp is a pointer to the structure
2059 * defining the interface to be attached, dlt is the link layer type,
2060 * and hdrlen is the fixed size of the link header (variable length
2061 * headers are not yet supporrted).
2062 */
2063 void
2064 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2065 {
2066 struct bpf_if *bp;
2067
2068 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
2069 if (bp == NULL)
2070 panic("bpfattach");
2071
2072 LIST_INIT(&bp->bif_dlist);
2073 bp->bif_ifp = ifp;
2074 bp->bif_dlt = dlt;
2075 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF);
2076 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
2077 *driverp = bp;
2078
2079 mtx_lock(&bpf_mtx);
2080 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
2081 mtx_unlock(&bpf_mtx);
2082
2083 /*
2084 * Compute the length of the bpf header. This is not necessarily
2085 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
2086 * that the network layer header begins on a longword boundary (for
2087 * performance reasons and to alleviate alignment restrictions).
2088 */
2089 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
2090
2091 if (bootverbose)
2092 if_printf(ifp, "bpf attached\n");
2093 }
2094
2095 /*
2096 * Detach bpf from an interface. This involves detaching each descriptor
2097 * associated with the interface, and leaving bd_bif NULL. Notify each
2098 * descriptor as it's detached so that any sleepers wake up and get
2099 * ENXIO.
2100 */
2101 void
2102 bpfdetach(struct ifnet *ifp)
2103 {
2104 struct bpf_if *bp;
2105 struct bpf_d *d;
2106
2107 /* Locate BPF interface information */
2108 mtx_lock(&bpf_mtx);
2109 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2110 if (ifp == bp->bif_ifp)
2111 break;
2112 }
2113
2114 /* Interface wasn't attached */
2115 if ((bp == NULL) || (bp->bif_ifp == NULL)) {
2116 mtx_unlock(&bpf_mtx);
2117 printf("bpfdetach: %s was not attached\n", ifp->if_xname);
2118 return;
2119 }
2120
2121 LIST_REMOVE(bp, bif_next);
2122 mtx_unlock(&bpf_mtx);
2123
2124 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
2125 bpf_detachd(d);
2126 BPFD_LOCK(d);
2127 bpf_wakeup(d);
2128 BPFD_UNLOCK(d);
2129 }
2130
2131 mtx_destroy(&bp->bif_mtx);
2132 free(bp, M_BPF);
2133 }
2134
2135 /*
2136 * Get a list of available data link type of the interface.
2137 */
2138 static int
2139 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
2140 {
2141 int n, error;
2142 struct ifnet *ifp;
2143 struct bpf_if *bp;
2144
2145 ifp = d->bd_bif->bif_ifp;
2146 n = 0;
2147 error = 0;
2148 mtx_lock(&bpf_mtx);
2149 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2150 if (bp->bif_ifp != ifp)
2151 continue;
2152 if (bfl->bfl_list != NULL) {
2153 if (n >= bfl->bfl_len) {
2154 mtx_unlock(&bpf_mtx);
2155 return (ENOMEM);
2156 }
2157 error = copyout(&bp->bif_dlt,
2158 bfl->bfl_list + n, sizeof(u_int));
2159 }
2160 n++;
2161 }
2162 mtx_unlock(&bpf_mtx);
2163 bfl->bfl_len = n;
2164 return (error);
2165 }
2166
2167 /*
2168 * Set the data link type of a BPF instance.
2169 */
2170 static int
2171 bpf_setdlt(struct bpf_d *d, u_int dlt)
2172 {
2173 int error, opromisc;
2174 struct ifnet *ifp;
2175 struct bpf_if *bp;
2176
2177 if (d->bd_bif->bif_dlt == dlt)
2178 return (0);
2179 ifp = d->bd_bif->bif_ifp;
2180 mtx_lock(&bpf_mtx);
2181 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2182 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
2183 break;
2184 }
2185 mtx_unlock(&bpf_mtx);
2186 if (bp != NULL) {
2187 opromisc = d->bd_promisc;
2188 bpf_detachd(d);
2189 bpf_attachd(d, bp);
2190 BPFD_LOCK(d);
2191 reset_d(d);
2192 BPFD_UNLOCK(d);
2193 if (opromisc) {
2194 error = ifpromisc(bp->bif_ifp, 1);
2195 if (error)
2196 if_printf(bp->bif_ifp,
2197 "bpf_setdlt: ifpromisc failed (%d)\n",
2198 error);
2199 else
2200 d->bd_promisc = 1;
2201 }
2202 }
2203 return (bp == NULL ? EINVAL : 0);
2204 }
2205
2206 static void
2207 bpf_drvinit(void *unused)
2208 {
2209 struct cdev *dev;
2210
2211 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
2212 LIST_INIT(&bpf_iflist);
2213
2214 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf");
2215 /* For compatibility */
2216 make_dev_alias(dev, "bpf0");
2217 }
2218
2219 /*
2220 * Zero out the various packet counters associated with all of the bpf
2221 * descriptors. At some point, we will probably want to get a bit more
2222 * granular and allow the user to specify descriptors to be zeroed.
2223 */
2224 static void
2225 bpf_zero_counters(void)
2226 {
2227 struct bpf_if *bp;
2228 struct bpf_d *bd;
2229
2230 mtx_lock(&bpf_mtx);
2231 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2232 BPFIF_LOCK(bp);
2233 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2234 BPFD_LOCK(bd);
2235 bd->bd_rcount = 0;
2236 bd->bd_dcount = 0;
2237 bd->bd_fcount = 0;
2238 bd->bd_wcount = 0;
2239 bd->bd_wfcount = 0;
2240 bd->bd_zcopy = 0;
2241 BPFD_UNLOCK(bd);
2242 }
2243 BPFIF_UNLOCK(bp);
2244 }
2245 mtx_unlock(&bpf_mtx);
2246 }
2247
2248 static void
2249 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
2250 {
2251
2252 bzero(d, sizeof(*d));
2253 BPFD_LOCK_ASSERT(bd);
2254 d->bd_structsize = sizeof(*d);
2255 d->bd_immediate = bd->bd_immediate;
2256 d->bd_promisc = bd->bd_promisc;
2257 d->bd_hdrcmplt = bd->bd_hdrcmplt;
2258 d->bd_direction = bd->bd_direction;
2259 d->bd_feedback = bd->bd_feedback;
2260 d->bd_async = bd->bd_async;
2261 d->bd_rcount = bd->bd_rcount;
2262 d->bd_dcount = bd->bd_dcount;
2263 d->bd_fcount = bd->bd_fcount;
2264 d->bd_sig = bd->bd_sig;
2265 d->bd_slen = bd->bd_slen;
2266 d->bd_hlen = bd->bd_hlen;
2267 d->bd_bufsize = bd->bd_bufsize;
2268 d->bd_pid = bd->bd_pid;
2269 strlcpy(d->bd_ifname,
2270 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
2271 d->bd_locked = bd->bd_locked;
2272 d->bd_wcount = bd->bd_wcount;
2273 d->bd_wdcount = bd->bd_wdcount;
2274 d->bd_wfcount = bd->bd_wfcount;
2275 d->bd_zcopy = bd->bd_zcopy;
2276 d->bd_bufmode = bd->bd_bufmode;
2277 }
2278
2279 static int
2280 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS)
2281 {
2282 struct xbpf_d *xbdbuf, *xbd, zerostats;
2283 int index, error;
2284 struct bpf_if *bp;
2285 struct bpf_d *bd;
2286
2287 /*
2288 * XXX This is not technically correct. It is possible for non
2289 * privileged users to open bpf devices. It would make sense
2290 * if the users who opened the devices were able to retrieve
2291 * the statistics for them, too.
2292 */
2293 error = priv_check(req->td, PRIV_NET_BPF);
2294 if (error)
2295 return (error);
2296 /*
2297 * Check to see if the user is requesting that the counters be
2298 * zeroed out. Explicitly check that the supplied data is zeroed,
2299 * as we aren't allowing the user to set the counters currently.
2300 */
2301 if (req->newptr != NULL) {
2302 if (req->newlen != sizeof(zerostats))
2303 return (EINVAL);
2304 bzero(&zerostats, sizeof(zerostats));
2305 xbd = req->newptr;
2306 if (bcmp(xbd, &zerostats, sizeof(*xbd)) != 0)
2307 return (EINVAL);
2308 bpf_zero_counters();
2309 return (0);
2310 }
2311 if (req->oldptr == NULL)
2312 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd)));
2313 if (bpf_bpfd_cnt == 0)
2314 return (SYSCTL_OUT(req, 0, 0));
2315 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK);
2316 mtx_lock(&bpf_mtx);
2317 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) {
2318 mtx_unlock(&bpf_mtx);
2319 free(xbdbuf, M_BPF);
2320 return (ENOMEM);
2321 }
2322 index = 0;
2323 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2324 BPFIF_LOCK(bp);
2325 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2326 xbd = &xbdbuf[index++];
2327 BPFD_LOCK(bd);
2328 bpfstats_fill_xbpf(xbd, bd);
2329 BPFD_UNLOCK(bd);
2330 }
2331 BPFIF_UNLOCK(bp);
2332 }
2333 mtx_unlock(&bpf_mtx);
2334 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd));
2335 free(xbdbuf, M_BPF);
2336 return (error);
2337 }
2338
2339 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL);
2340
2341 #else /* !DEV_BPF && !NETGRAPH_BPF */
2342 /*
2343 * NOP stubs to allow bpf-using drivers to load and function.
2344 *
2345 * A 'better' implementation would allow the core bpf functionality
2346 * to be loaded at runtime.
2347 */
2348 static struct bpf_if bp_null;
2349
2350 void
2351 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2352 {
2353 }
2354
2355 void
2356 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2357 {
2358 }
2359
2360 void
2361 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m)
2362 {
2363 }
2364
2365 void
2366 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2367 {
2368
2369 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2370 }
2371
2372 void
2373 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2374 {
2375
2376 *driverp = &bp_null;
2377 }
2378
2379 void
2380 bpfdetach(struct ifnet *ifp)
2381 {
2382 }
2383
2384 u_int
2385 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
2386 {
2387 return -1; /* "no filter" behaviour */
2388 }
2389
2390 int
2391 bpf_validate(const struct bpf_insn *f, int len)
2392 {
2393 return 0; /* false */
2394 }
2395
2396 #endif /* !DEV_BPF && !NETGRAPH_BPF */
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