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ed(1): simplify by using arc4random_buf().
[freebsd-src.git] / sys / net / bpf.c
blob3b12cf4cb501ec590d331d2ff2632afdb5480a2c
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("$FreeBSD$");
39
40 #include "opt_bpf.h"
41 #include "opt_compat.h"
42 #include "opt_ddb.h"
43 #include "opt_netgraph.h"
44
45 #include <sys/types.h>
46 #include <sys/param.h>
47 #include <sys/lock.h>
48 #include <sys/rwlock.h>
49 #include <sys/systm.h>
50 #include <sys/conf.h>
51 #include <sys/fcntl.h>
52 #include <sys/jail.h>
53 #include <sys/malloc.h>
54 #include <sys/mbuf.h>
55 #include <sys/time.h>
56 #include <sys/priv.h>
57 #include <sys/proc.h>
58 #include <sys/signalvar.h>
59 #include <sys/filio.h>
60 #include <sys/sockio.h>
61 #include <sys/ttycom.h>
62 #include <sys/uio.h>
63
64 #include <sys/event.h>
65 #include <sys/file.h>
66 #include <sys/poll.h>
67 #include <sys/proc.h>
68
69 #include <sys/socket.h>
70
71 #ifdef DDB
72 #include <ddb/ddb.h>
73 #endif
74
75 #include <net/if.h>
76 #include <net/if_var.h>
77 #include <net/if_dl.h>
78 #include <net/bpf.h>
79 #include <net/bpf_buffer.h>
80 #ifdef BPF_JITTER
81 #include <net/bpf_jitter.h>
82 #endif
83 #include <net/bpf_zerocopy.h>
84 #include <net/bpfdesc.h>
85 #include <net/route.h>
86 #include <net/vnet.h>
87
88 #include <netinet/in.h>
89 #include <netinet/if_ether.h>
90 #include <sys/kernel.h>
91 #include <sys/sysctl.h>
92
93 #include <net80211/ieee80211_freebsd.h>
94
95 #include <security/mac/mac_framework.h>
96
97 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
98
99 struct bpf_if {
100 #define bif_next bif_ext.bif_next
101 #define bif_dlist bif_ext.bif_dlist
102 struct bpf_if_ext bif_ext; /* public members */
103 u_int bif_dlt; /* link layer type */
104 u_int bif_hdrlen; /* length of link header */
105 struct ifnet *bif_ifp; /* corresponding interface */
106 struct rwlock bif_lock; /* interface lock */
107 LIST_HEAD(, bpf_d) bif_wlist; /* writer-only list */
108 int bif_flags; /* Interface flags */
109 };
110
111 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0);
112
113 #if defined(DEV_BPF) || defined(NETGRAPH_BPF)
114
115 #define PRINET 26 /* interruptible */
116
117 #define SIZEOF_BPF_HDR(type) \
118 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen))
119
120 #ifdef COMPAT_FREEBSD32
121 #include <sys/mount.h>
122 #include <compat/freebsd32/freebsd32.h>
123 #define BPF_ALIGNMENT32 sizeof(int32_t)
124 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32)
125
126 #ifndef BURN_BRIDGES
127 /*
128 * 32-bit version of structure prepended to each packet. We use this header
129 * instead of the standard one for 32-bit streams. We mark the a stream as
130 * 32-bit the first time we see a 32-bit compat ioctl request.
131 */
132 struct bpf_hdr32 {
133 struct timeval32 bh_tstamp; /* time stamp */
134 uint32_t bh_caplen; /* length of captured portion */
135 uint32_t bh_datalen; /* original length of packet */
136 uint16_t bh_hdrlen; /* length of bpf header (this struct
137 plus alignment padding) */
138 };
139 #endif
140
141 struct bpf_program32 {
142 u_int bf_len;
143 uint32_t bf_insns;
144 };
145
146 struct bpf_dltlist32 {
147 u_int bfl_len;
148 u_int bfl_list;
149 };
150
151 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32)
152 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32)
153 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32)
154 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32)
155 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32)
156 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32)
157 #endif
158
159 /*
160 * bpf_iflist is a list of BPF interface structures, each corresponding to a
161 * specific DLT. The same network interface might have several BPF interface
162 * structures registered by different layers in the stack (i.e., 802.11
163 * frames, ethernet frames, etc).
164 */
165 static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist;
166 static struct mtx bpf_mtx; /* bpf global lock */
167 static int bpf_bpfd_cnt;
168
169 static void bpf_attachd(struct bpf_d *, struct bpf_if *);
170 static void bpf_detachd(struct bpf_d *);
171 static void bpf_detachd_locked(struct bpf_d *);
172 static void bpf_freed(struct bpf_d *);
173 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **,
174 struct sockaddr *, int *, struct bpf_d *);
175 static int bpf_setif(struct bpf_d *, struct ifreq *);
176 static void bpf_timed_out(void *);
177 static __inline void
178 bpf_wakeup(struct bpf_d *);
179 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
180 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int),
181 struct bintime *);
182 static void reset_d(struct bpf_d *);
183 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
184 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
185 static int bpf_setdlt(struct bpf_d *, u_int);
186 static void filt_bpfdetach(struct knote *);
187 static int filt_bpfread(struct knote *, long);
188 static void bpf_drvinit(void *);
189 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS);
190
191 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl");
192 int bpf_maxinsns = BPF_MAXINSNS;
193 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW,
194 &bpf_maxinsns, 0, "Maximum bpf program instructions");
195 static int bpf_zerocopy_enable = 0;
196 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW,
197 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions");
198 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW,
199 bpf_stats_sysctl, "bpf statistics portal");
200
201 static VNET_DEFINE(int, bpf_optimize_writers) = 0;
202 #define V_bpf_optimize_writers VNET(bpf_optimize_writers)
203 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RW,
204 &VNET_NAME(bpf_optimize_writers), 0,
205 "Do not send packets until BPF program is set");
206
207 static d_open_t bpfopen;
208 static d_read_t bpfread;
209 static d_write_t bpfwrite;
210 static d_ioctl_t bpfioctl;
211 static d_poll_t bpfpoll;
212 static d_kqfilter_t bpfkqfilter;
213
214 static struct cdevsw bpf_cdevsw = {
215 .d_version = D_VERSION,
216 .d_open = bpfopen,
217 .d_read = bpfread,
218 .d_write = bpfwrite,
219 .d_ioctl = bpfioctl,
220 .d_poll = bpfpoll,
221 .d_name = "bpf",
222 .d_kqfilter = bpfkqfilter,
223 };
224
225 static struct filterops bpfread_filtops = {
226 .f_isfd = 1,
227 .f_detach = filt_bpfdetach,
228 .f_event = filt_bpfread,
229 };
230
231 eventhandler_tag bpf_ifdetach_cookie = NULL;
232
233 /*
234 * LOCKING MODEL USED BY BPF:
235 * Locks:
236 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal,
237 * some global counters and every bpf_if reference.
238 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters.
239 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields
240 * used by bpf_mtap code.
241 *
242 * Lock order:
243 *
244 * Global lock, interface lock, descriptor lock
245 *
246 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2]
247 * working model. In many places (like bpf_detachd) we start with BPF descriptor
248 * (and we need to at least rlock it to get reliable interface pointer). This
249 * gives us potential LOR. As a result, we use global lock to protect from bpf_if
250 * change in every such place.
251 *
252 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and
253 * 3) descriptor main wlock.
254 * Reading bd_bif can be protected by any of these locks, typically global lock.
255 *
256 * Changing read/write BPF filter is protected by the same three locks,
257 * the same applies for reading.
258 *
259 * Sleeping in global lock is not allowed due to bpfdetach() using it.
260 */
261
262 /*
263 * Wrapper functions for various buffering methods. If the set of buffer
264 * modes expands, we will probably want to introduce a switch data structure
265 * similar to protosw, et.
266 */
267 static void
268 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
269 u_int len)
270 {
271
272 BPFD_LOCK_ASSERT(d);
273
274 switch (d->bd_bufmode) {
275 case BPF_BUFMODE_BUFFER:
276 return (bpf_buffer_append_bytes(d, buf, offset, src, len));
277
278 case BPF_BUFMODE_ZBUF:
279 d->bd_zcopy++;
280 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len));
281
282 default:
283 panic("bpf_buf_append_bytes");
284 }
285 }
286
287 static void
288 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
289 u_int len)
290 {
291
292 BPFD_LOCK_ASSERT(d);
293
294 switch (d->bd_bufmode) {
295 case BPF_BUFMODE_BUFFER:
296 return (bpf_buffer_append_mbuf(d, buf, offset, src, len));
297
298 case BPF_BUFMODE_ZBUF:
299 d->bd_zcopy++;
300 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len));
301
302 default:
303 panic("bpf_buf_append_mbuf");
304 }
305 }
306
307 /*
308 * This function gets called when the free buffer is re-assigned.
309 */
310 static void
311 bpf_buf_reclaimed(struct bpf_d *d)
312 {
313
314 BPFD_LOCK_ASSERT(d);
315
316 switch (d->bd_bufmode) {
317 case BPF_BUFMODE_BUFFER:
318 return;
319
320 case BPF_BUFMODE_ZBUF:
321 bpf_zerocopy_buf_reclaimed(d);
322 return;
323
324 default:
325 panic("bpf_buf_reclaimed");
326 }
327 }
328
329 /*
330 * If the buffer mechanism has a way to decide that a held buffer can be made
331 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is
332 * returned if the buffer can be discarded, (0) is returned if it cannot.
333 */
334 static int
335 bpf_canfreebuf(struct bpf_d *d)
336 {
337
338 BPFD_LOCK_ASSERT(d);
339
340 switch (d->bd_bufmode) {
341 case BPF_BUFMODE_ZBUF:
342 return (bpf_zerocopy_canfreebuf(d));
343 }
344 return (0);
345 }
346
347 /*
348 * Allow the buffer model to indicate that the current store buffer is
349 * immutable, regardless of the appearance of space. Return (1) if the
350 * buffer is writable, and (0) if not.
351 */
352 static int
353 bpf_canwritebuf(struct bpf_d *d)
354 {
355 BPFD_LOCK_ASSERT(d);
356
357 switch (d->bd_bufmode) {
358 case BPF_BUFMODE_ZBUF:
359 return (bpf_zerocopy_canwritebuf(d));
360 }
361 return (1);
362 }
363
364 /*
365 * Notify buffer model that an attempt to write to the store buffer has
366 * resulted in a dropped packet, in which case the buffer may be considered
367 * full.
368 */
369 static void
370 bpf_buffull(struct bpf_d *d)
371 {
372
373 BPFD_LOCK_ASSERT(d);
374
375 switch (d->bd_bufmode) {
376 case BPF_BUFMODE_ZBUF:
377 bpf_zerocopy_buffull(d);
378 break;
379 }
380 }
381
382 /*
383 * Notify the buffer model that a buffer has moved into the hold position.
384 */
385 void
386 bpf_bufheld(struct bpf_d *d)
387 {
388
389 BPFD_LOCK_ASSERT(d);
390
391 switch (d->bd_bufmode) {
392 case BPF_BUFMODE_ZBUF:
393 bpf_zerocopy_bufheld(d);
394 break;
395 }
396 }
397
398 static void
399 bpf_free(struct bpf_d *d)
400 {
401
402 switch (d->bd_bufmode) {
403 case BPF_BUFMODE_BUFFER:
404 return (bpf_buffer_free(d));
405
406 case BPF_BUFMODE_ZBUF:
407 return (bpf_zerocopy_free(d));
408
409 default:
410 panic("bpf_buf_free");
411 }
412 }
413
414 static int
415 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
416 {
417
418 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
419 return (EOPNOTSUPP);
420 return (bpf_buffer_uiomove(d, buf, len, uio));
421 }
422
423 static int
424 bpf_ioctl_sblen(struct bpf_d *d, u_int *i)
425 {
426
427 if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
428 return (EOPNOTSUPP);
429 return (bpf_buffer_ioctl_sblen(d, i));
430 }
431
432 static int
433 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i)
434 {
435
436 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
437 return (EOPNOTSUPP);
438 return (bpf_zerocopy_ioctl_getzmax(td, d, i));
439 }
440
441 static int
442 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
443 {
444
445 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
446 return (EOPNOTSUPP);
447 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz));
448 }
449
450 static int
451 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
452 {
453
454 if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
455 return (EOPNOTSUPP);
456 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz));
457 }
458
459 /*
460 * General BPF functions.
461 */
462 static int
463 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp,
464 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d)
465 {
466 const struct ieee80211_bpf_params *p;
467 struct ether_header *eh;
468 struct mbuf *m;
469 int error;
470 int len;
471 int hlen;
472 int slen;
473
474 /*
475 * Build a sockaddr based on the data link layer type.
476 * We do this at this level because the ethernet header
477 * is copied directly into the data field of the sockaddr.
478 * In the case of SLIP, there is no header and the packet
479 * is forwarded as is.
480 * Also, we are careful to leave room at the front of the mbuf
481 * for the link level header.
482 */
483 switch (linktype) {
484
485 case DLT_SLIP:
486 sockp->sa_family = AF_INET;
487 hlen = 0;
488 break;
489
490 case DLT_EN10MB:
491 sockp->sa_family = AF_UNSPEC;
492 /* XXX Would MAXLINKHDR be better? */
493 hlen = ETHER_HDR_LEN;
494 break;
495
496 case DLT_FDDI:
497 sockp->sa_family = AF_IMPLINK;
498 hlen = 0;
499 break;
500
501 case DLT_RAW:
502 sockp->sa_family = AF_UNSPEC;
503 hlen = 0;
504 break;
505
506 case DLT_NULL:
507 /*
508 * null interface types require a 4 byte pseudo header which
509 * corresponds to the address family of the packet.
510 */
511 sockp->sa_family = AF_UNSPEC;
512 hlen = 4;
513 break;
514
515 case DLT_ATM_RFC1483:
516 /*
517 * en atm driver requires 4-byte atm pseudo header.
518 * though it isn't standard, vpi:vci needs to be
519 * specified anyway.
520 */
521 sockp->sa_family = AF_UNSPEC;
522 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
523 break;
524
525 case DLT_PPP:
526 sockp->sa_family = AF_UNSPEC;
527 hlen = 4; /* This should match PPP_HDRLEN */
528 break;
529
530 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
531 sockp->sa_family = AF_IEEE80211;
532 hlen = 0;
533 break;
534
535 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
536 sockp->sa_family = AF_IEEE80211;
537 sockp->sa_len = 12; /* XXX != 0 */
538 hlen = sizeof(struct ieee80211_bpf_params);
539 break;
540
541 default:
542 return (EIO);
543 }
544
545 len = uio->uio_resid;
546 if (len < hlen || len - hlen > ifp->if_mtu)
547 return (EMSGSIZE);
548
549 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR);
550 if (m == NULL)
551 return (EIO);
552 m->m_pkthdr.len = m->m_len = len;
553 *mp = m;
554
555 error = uiomove(mtod(m, u_char *), len, uio);
556 if (error)
557 goto bad;
558
559 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len);
560 if (slen == 0) {
561 error = EPERM;
562 goto bad;
563 }
564
565 /* Check for multicast destination */
566 switch (linktype) {
567 case DLT_EN10MB:
568 eh = mtod(m, struct ether_header *);
569 if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
570 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
571 ETHER_ADDR_LEN) == 0)
572 m->m_flags |= M_BCAST;
573 else
574 m->m_flags |= M_MCAST;
575 }
576 if (d->bd_hdrcmplt == 0) {
577 memcpy(eh->ether_shost, IF_LLADDR(ifp),
578 sizeof(eh->ether_shost));
579 }
580 break;
581 }
582
583 /*
584 * Make room for link header, and copy it to sockaddr
585 */
586 if (hlen != 0) {
587 if (sockp->sa_family == AF_IEEE80211) {
588 /*
589 * Collect true length from the parameter header
590 * NB: sockp is known to be zero'd so if we do a
591 * short copy unspecified parameters will be
592 * zero.
593 * NB: packet may not be aligned after stripping
594 * bpf params
595 * XXX check ibp_vers
596 */
597 p = mtod(m, const struct ieee80211_bpf_params *);
598 hlen = p->ibp_len;
599 if (hlen > sizeof(sockp->sa_data)) {
600 error = EINVAL;
601 goto bad;
602 }
603 }
604 bcopy(mtod(m, const void *), sockp->sa_data, hlen);
605 }
606 *hdrlen = hlen;
607
608 return (0);
609 bad:
610 m_freem(m);
611 return (error);
612 }
613
614 /*
615 * Attach file to the bpf interface, i.e. make d listen on bp.
616 */
617 static void
618 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
619 {
620 int op_w;
621
622 BPF_LOCK_ASSERT();
623
624 /*
625 * Save sysctl value to protect from sysctl change
626 * between reads
627 */
628 op_w = V_bpf_optimize_writers || d->bd_writer;
629
630 if (d->bd_bif != NULL)
631 bpf_detachd_locked(d);
632 /*
633 * Point d at bp, and add d to the interface's list.
634 * Since there are many applications using BPF for
635 * sending raw packets only (dhcpd, cdpd are good examples)
636 * we can delay adding d to the list of active listeners until
637 * some filter is configured.
638 */
639
640 BPFIF_WLOCK(bp);
641 BPFD_LOCK(d);
642
643 d->bd_bif = bp;
644
645 if (op_w != 0) {
646 /* Add to writers-only list */
647 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next);
648 /*
649 * We decrement bd_writer on every filter set operation.
650 * First BIOCSETF is done by pcap_open_live() to set up
651 * snap length. After that appliation usually sets its own filter
652 */
653 d->bd_writer = 2;
654 } else
655 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
656
657 BPFD_UNLOCK(d);
658 BPFIF_WUNLOCK(bp);
659
660 bpf_bpfd_cnt++;
661
662 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list",
663 __func__, d->bd_pid, d->bd_writer ? "writer" : "active");
664
665 if (op_w == 0)
666 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
667 }
668
669 /*
670 * Check if we need to upgrade our descriptor @d from write-only mode.
671 */
672 static int
673 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen)
674 {
675 int is_snap, need_upgrade;
676
677 /*
678 * Check if we've already upgraded or new filter is empty.
679 */
680 if (d->bd_writer == 0 || fcode == NULL)
681 return (0);
682
683 need_upgrade = 0;
684
685 /*
686 * Check if cmd looks like snaplen setting from
687 * pcap_bpf.c:pcap_open_live().
688 * Note we're not checking .k value here:
689 * while pcap_open_live() definitely sets to to non-zero value,
690 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g.
691 * do not consider upgrading immediately
692 */
693 if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K))
694 is_snap = 1;
695 else
696 is_snap = 0;
697
698 if (is_snap == 0) {
699 /*
700 * We're setting first filter and it doesn't look like
701 * setting snaplen. We're probably using bpf directly.
702 * Upgrade immediately.
703 */
704 need_upgrade = 1;
705 } else {
706 /*
707 * Do not require upgrade by first BIOCSETF
708 * (used to set snaplen) by pcap_open_live().
709 */
710
711 if (--d->bd_writer == 0) {
712 /*
713 * First snaplen filter has already
714 * been set. This is probably catch-all
715 * filter
716 */
717 need_upgrade = 1;
718 }
719 }
720
721 CTR5(KTR_NET,
722 "%s: filter function set by pid %d, "
723 "bd_writer counter %d, snap %d upgrade %d",
724 __func__, d->bd_pid, d->bd_writer,
725 is_snap, need_upgrade);
726
727 return (need_upgrade);
728 }
729
730 /*
731 * Add d to the list of active bp filters.
732 * Requires bpf_attachd() to be called before.
733 */
734 static void
735 bpf_upgraded(struct bpf_d *d)
736 {
737 struct bpf_if *bp;
738
739 BPF_LOCK_ASSERT();
740
741 bp = d->bd_bif;
742
743 /*
744 * Filter can be set several times without specifying interface.
745 * Mark d as reader and exit.
746 */
747 if (bp == NULL) {
748 BPFD_LOCK(d);
749 d->bd_writer = 0;
750 BPFD_UNLOCK(d);
751 return;
752 }
753
754 BPFIF_WLOCK(bp);
755 BPFD_LOCK(d);
756
757 /* Remove from writers-only list */
758 LIST_REMOVE(d, bd_next);
759 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
760 /* Mark d as reader */
761 d->bd_writer = 0;
762
763 BPFD_UNLOCK(d);
764 BPFIF_WUNLOCK(bp);
765
766 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid);
767
768 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
769 }
770
771 /*
772 * Detach a file from its interface.
773 */
774 static void
775 bpf_detachd(struct bpf_d *d)
776 {
777 BPF_LOCK();
778 bpf_detachd_locked(d);
779 BPF_UNLOCK();
780 }
781
782 static void
783 bpf_detachd_locked(struct bpf_d *d)
784 {
785 int error;
786 struct bpf_if *bp;
787 struct ifnet *ifp;
788
789 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid);
790
791 BPF_LOCK_ASSERT();
792
793 /* Check if descriptor is attached */
794 if ((bp = d->bd_bif) == NULL)
795 return;
796
797 BPFIF_WLOCK(bp);
798 BPFD_LOCK(d);
799
800 /* Save bd_writer value */
801 error = d->bd_writer;
802
803 /*
804 * Remove d from the interface's descriptor list.
805 */
806 LIST_REMOVE(d, bd_next);
807
808 ifp = bp->bif_ifp;
809 d->bd_bif = NULL;
810 BPFD_UNLOCK(d);
811 BPFIF_WUNLOCK(bp);
812
813 bpf_bpfd_cnt--;
814
815 /* Call event handler iff d is attached */
816 if (error == 0)
817 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
818
819 /*
820 * Check if this descriptor had requested promiscuous mode.
821 * If so, turn it off.
822 */
823 if (d->bd_promisc) {
824 d->bd_promisc = 0;
825 CURVNET_SET(ifp->if_vnet);
826 error = ifpromisc(ifp, 0);
827 CURVNET_RESTORE();
828 if (error != 0 && error != ENXIO) {
829 /*
830 * ENXIO can happen if a pccard is unplugged
831 * Something is really wrong if we were able to put
832 * the driver into promiscuous mode, but can't
833 * take it out.
834 */
835 if_printf(bp->bif_ifp,
836 "bpf_detach: ifpromisc failed (%d)\n", error);
837 }
838 }
839 }
840
841 /*
842 * Close the descriptor by detaching it from its interface,
843 * deallocating its buffers, and marking it free.
844 */
845 static void
846 bpf_dtor(void *data)
847 {
848 struct bpf_d *d = data;
849
850 BPFD_LOCK(d);
851 if (d->bd_state == BPF_WAITING)
852 callout_stop(&d->bd_callout);
853 d->bd_state = BPF_IDLE;
854 BPFD_UNLOCK(d);
855 funsetown(&d->bd_sigio);
856 bpf_detachd(d);
857 #ifdef MAC
858 mac_bpfdesc_destroy(d);
859 #endif /* MAC */
860 seldrain(&d->bd_sel);
861 knlist_destroy(&d->bd_sel.si_note);
862 callout_drain(&d->bd_callout);
863 bpf_freed(d);
864 free(d, M_BPF);
865 }
866
867 /*
868 * Open ethernet device. Returns ENXIO for illegal minor device number,
869 * EBUSY if file is open by another process.
870 */
871 /* ARGSUSED */
872 static int
873 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td)
874 {
875 struct bpf_d *d;
876 int error;
877
878 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
879 error = devfs_set_cdevpriv(d, bpf_dtor);
880 if (error != 0) {
881 free(d, M_BPF);
882 return (error);
883 }
884
885 /*
886 * For historical reasons, perform a one-time initialization call to
887 * the buffer routines, even though we're not yet committed to a
888 * particular buffer method.
889 */
890 bpf_buffer_init(d);
891 if ((flags & FREAD) == 0)
892 d->bd_writer = 2;
893 d->bd_hbuf_in_use = 0;
894 d->bd_bufmode = BPF_BUFMODE_BUFFER;
895 d->bd_sig = SIGIO;
896 d->bd_direction = BPF_D_INOUT;
897 BPF_PID_REFRESH(d, td);
898 #ifdef MAC
899 mac_bpfdesc_init(d);
900 mac_bpfdesc_create(td->td_ucred, d);
901 #endif
902 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF);
903 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0);
904 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock);
905
906 return (0);
907 }
908
909 /*
910 * bpfread - read next chunk of packets from buffers
911 */
912 static int
913 bpfread(struct cdev *dev, struct uio *uio, int ioflag)
914 {
915 struct bpf_d *d;
916 int error;
917 int non_block;
918 int timed_out;
919
920 error = devfs_get_cdevpriv((void **)&d);
921 if (error != 0)
922 return (error);
923
924 /*
925 * Restrict application to use a buffer the same size as
926 * as kernel buffers.
927 */
928 if (uio->uio_resid != d->bd_bufsize)
929 return (EINVAL);
930
931 non_block = ((ioflag & O_NONBLOCK) != 0);
932
933 BPFD_LOCK(d);
934 BPF_PID_REFRESH_CUR(d);
935 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
936 BPFD_UNLOCK(d);
937 return (EOPNOTSUPP);
938 }
939 if (d->bd_state == BPF_WAITING)
940 callout_stop(&d->bd_callout);
941 timed_out = (d->bd_state == BPF_TIMED_OUT);
942 d->bd_state = BPF_IDLE;
943 while (d->bd_hbuf_in_use) {
944 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
945 PRINET|PCATCH, "bd_hbuf", 0);
946 if (error != 0) {
947 BPFD_UNLOCK(d);
948 return (error);
949 }
950 }
951 /*
952 * If the hold buffer is empty, then do a timed sleep, which
953 * ends when the timeout expires or when enough packets
954 * have arrived to fill the store buffer.
955 */
956 while (d->bd_hbuf == NULL) {
957 if (d->bd_slen != 0) {
958 /*
959 * A packet(s) either arrived since the previous
960 * read or arrived while we were asleep.
961 */
962 if (d->bd_immediate || non_block || timed_out) {
963 /*
964 * Rotate the buffers and return what's here
965 * if we are in immediate mode, non-blocking
966 * flag is set, or this descriptor timed out.
967 */
968 ROTATE_BUFFERS(d);
969 break;
970 }
971 }
972
973 /*
974 * No data is available, check to see if the bpf device
975 * is still pointed at a real interface. If not, return
976 * ENXIO so that the userland process knows to rebind
977 * it before using it again.
978 */
979 if (d->bd_bif == NULL) {
980 BPFD_UNLOCK(d);
981 return (ENXIO);
982 }
983
984 if (non_block) {
985 BPFD_UNLOCK(d);
986 return (EWOULDBLOCK);
987 }
988 error = msleep(d, &d->bd_lock, PRINET|PCATCH,
989 "bpf", d->bd_rtout);
990 if (error == EINTR || error == ERESTART) {
991 BPFD_UNLOCK(d);
992 return (error);
993 }
994 if (error == EWOULDBLOCK) {
995 /*
996 * On a timeout, return what's in the buffer,
997 * which may be nothing. If there is something
998 * in the store buffer, we can rotate the buffers.
999 */
1000 if (d->bd_hbuf)
1001 /*
1002 * We filled up the buffer in between
1003 * getting the timeout and arriving
1004 * here, so we don't need to rotate.
1005 */
1006 break;
1007
1008 if (d->bd_slen == 0) {
1009 BPFD_UNLOCK(d);
1010 return (0);
1011 }
1012 ROTATE_BUFFERS(d);
1013 break;
1014 }
1015 }
1016 /*
1017 * At this point, we know we have something in the hold slot.
1018 */
1019 d->bd_hbuf_in_use = 1;
1020 BPFD_UNLOCK(d);
1021
1022 /*
1023 * Move data from hold buffer into user space.
1024 * We know the entire buffer is transferred since
1025 * we checked above that the read buffer is bpf_bufsize bytes.
1026 *
1027 * We do not have to worry about simultaneous reads because
1028 * we waited for sole access to the hold buffer above.
1029 */
1030 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio);
1031
1032 BPFD_LOCK(d);
1033 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf"));
1034 d->bd_fbuf = d->bd_hbuf;
1035 d->bd_hbuf = NULL;
1036 d->bd_hlen = 0;
1037 bpf_buf_reclaimed(d);
1038 d->bd_hbuf_in_use = 0;
1039 wakeup(&d->bd_hbuf_in_use);
1040 BPFD_UNLOCK(d);
1041
1042 return (error);
1043 }
1044
1045 /*
1046 * If there are processes sleeping on this descriptor, wake them up.
1047 */
1048 static __inline void
1049 bpf_wakeup(struct bpf_d *d)
1050 {
1051
1052 BPFD_LOCK_ASSERT(d);
1053 if (d->bd_state == BPF_WAITING) {
1054 callout_stop(&d->bd_callout);
1055 d->bd_state = BPF_IDLE;
1056 }
1057 wakeup(d);
1058 if (d->bd_async && d->bd_sig && d->bd_sigio)
1059 pgsigio(&d->bd_sigio, d->bd_sig, 0);
1060
1061 selwakeuppri(&d->bd_sel, PRINET);
1062 KNOTE_LOCKED(&d->bd_sel.si_note, 0);
1063 }
1064
1065 static void
1066 bpf_timed_out(void *arg)
1067 {
1068 struct bpf_d *d = (struct bpf_d *)arg;
1069
1070 BPFD_LOCK_ASSERT(d);
1071
1072 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout))
1073 return;
1074 if (d->bd_state == BPF_WAITING) {
1075 d->bd_state = BPF_TIMED_OUT;
1076 if (d->bd_slen != 0)
1077 bpf_wakeup(d);
1078 }
1079 }
1080
1081 static int
1082 bpf_ready(struct bpf_d *d)
1083 {
1084
1085 BPFD_LOCK_ASSERT(d);
1086
1087 if (!bpf_canfreebuf(d) && d->bd_hlen != 0)
1088 return (1);
1089 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1090 d->bd_slen != 0)
1091 return (1);
1092 return (0);
1093 }
1094
1095 static int
1096 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag)
1097 {
1098 struct bpf_d *d;
1099 struct ifnet *ifp;
1100 struct mbuf *m, *mc;
1101 struct sockaddr dst;
1102 struct route ro;
1103 int error, hlen;
1104
1105 error = devfs_get_cdevpriv((void **)&d);
1106 if (error != 0)
1107 return (error);
1108
1109 BPF_PID_REFRESH_CUR(d);
1110 d->bd_wcount++;
1111 /* XXX: locking required */
1112 if (d->bd_bif == NULL) {
1113 d->bd_wdcount++;
1114 return (ENXIO);
1115 }
1116
1117 ifp = d->bd_bif->bif_ifp;
1118
1119 if ((ifp->if_flags & IFF_UP) == 0) {
1120 d->bd_wdcount++;
1121 return (ENETDOWN);
1122 }
1123
1124 if (uio->uio_resid == 0) {
1125 d->bd_wdcount++;
1126 return (0);
1127 }
1128
1129 bzero(&dst, sizeof(dst));
1130 m = NULL;
1131 hlen = 0;
1132 /* XXX: bpf_movein() can sleep */
1133 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp,
1134 &m, &dst, &hlen, d);
1135 if (error) {
1136 d->bd_wdcount++;
1137 return (error);
1138 }
1139 d->bd_wfcount++;
1140 if (d->bd_hdrcmplt)
1141 dst.sa_family = pseudo_AF_HDRCMPLT;
1142
1143 if (d->bd_feedback) {
1144 mc = m_dup(m, M_NOWAIT);
1145 if (mc != NULL)
1146 mc->m_pkthdr.rcvif = ifp;
1147 /* Set M_PROMISC for outgoing packets to be discarded. */
1148 if (d->bd_direction == BPF_D_INOUT)
1149 m->m_flags |= M_PROMISC;
1150 } else
1151 mc = NULL;
1152
1153 m->m_pkthdr.len -= hlen;
1154 m->m_len -= hlen;
1155 m->m_data += hlen; /* XXX */
1156
1157 CURVNET_SET(ifp->if_vnet);
1158 #ifdef MAC
1159 BPFD_LOCK(d);
1160 mac_bpfdesc_create_mbuf(d, m);
1161 if (mc != NULL)
1162 mac_bpfdesc_create_mbuf(d, mc);
1163 BPFD_UNLOCK(d);
1164 #endif
1165
1166 bzero(&ro, sizeof(ro));
1167 if (hlen != 0) {
1168 ro.ro_prepend = (u_char *)&dst.sa_data;
1169 ro.ro_plen = hlen;
1170 ro.ro_flags = RT_HAS_HEADER;
1171 }
1172
1173 error = (*ifp->if_output)(ifp, m, &dst, &ro);
1174 if (error)
1175 d->bd_wdcount++;
1176
1177 if (mc != NULL) {
1178 if (error == 0)
1179 (*ifp->if_input)(ifp, mc);
1180 else
1181 m_freem(mc);
1182 }
1183 CURVNET_RESTORE();
1184
1185 return (error);
1186 }
1187
1188 /*
1189 * Reset a descriptor by flushing its packet buffer and clearing the receive
1190 * and drop counts. This is doable for kernel-only buffers, but with
1191 * zero-copy buffers, we can't write to (or rotate) buffers that are
1192 * currently owned by userspace. It would be nice if we could encapsulate
1193 * this logic in the buffer code rather than here.
1194 */
1195 static void
1196 reset_d(struct bpf_d *d)
1197 {
1198
1199 BPFD_LOCK_ASSERT(d);
1200
1201 while (d->bd_hbuf_in_use)
1202 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET,
1203 "bd_hbuf", 0);
1204 if ((d->bd_hbuf != NULL) &&
1205 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) {
1206 /* Free the hold buffer. */
1207 d->bd_fbuf = d->bd_hbuf;
1208 d->bd_hbuf = NULL;
1209 d->bd_hlen = 0;
1210 bpf_buf_reclaimed(d);
1211 }
1212 if (bpf_canwritebuf(d))
1213 d->bd_slen = 0;
1214 d->bd_rcount = 0;
1215 d->bd_dcount = 0;
1216 d->bd_fcount = 0;
1217 d->bd_wcount = 0;
1218 d->bd_wfcount = 0;
1219 d->bd_wdcount = 0;
1220 d->bd_zcopy = 0;
1221 }
1222
1223 /*
1224 * FIONREAD Check for read packet available.
1225 * BIOCGBLEN Get buffer len [for read()].
1226 * BIOCSETF Set read filter.
1227 * BIOCSETFNR Set read filter without resetting descriptor.
1228 * BIOCSETWF Set write filter.
1229 * BIOCFLUSH Flush read packet buffer.
1230 * BIOCPROMISC Put interface into promiscuous mode.
1231 * BIOCGDLT Get link layer type.
1232 * BIOCGETIF Get interface name.
1233 * BIOCSETIF Set interface.
1234 * BIOCSRTIMEOUT Set read timeout.
1235 * BIOCGRTIMEOUT Get read timeout.
1236 * BIOCGSTATS Get packet stats.
1237 * BIOCIMMEDIATE Set immediate mode.
1238 * BIOCVERSION Get filter language version.
1239 * BIOCGHDRCMPLT Get "header already complete" flag
1240 * BIOCSHDRCMPLT Set "header already complete" flag
1241 * BIOCGDIRECTION Get packet direction flag
1242 * BIOCSDIRECTION Set packet direction flag
1243 * BIOCGTSTAMP Get time stamp format and resolution.
1244 * BIOCSTSTAMP Set time stamp format and resolution.
1245 * BIOCLOCK Set "locked" flag
1246 * BIOCFEEDBACK Set packet feedback mode.
1247 * BIOCSETZBUF Set current zero-copy buffer locations.
1248 * BIOCGETZMAX Get maximum zero-copy buffer size.
1249 * BIOCROTZBUF Force rotation of zero-copy buffer
1250 * BIOCSETBUFMODE Set buffer mode.
1251 * BIOCGETBUFMODE Get current buffer mode.
1252 */
1253 /* ARGSUSED */
1254 static int
1255 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
1256 struct thread *td)
1257 {
1258 struct bpf_d *d;
1259 int error;
1260
1261 error = devfs_get_cdevpriv((void **)&d);
1262 if (error != 0)
1263 return (error);
1264
1265 /*
1266 * Refresh PID associated with this descriptor.
1267 */
1268 BPFD_LOCK(d);
1269 BPF_PID_REFRESH(d, td);
1270 if (d->bd_state == BPF_WAITING)
1271 callout_stop(&d->bd_callout);
1272 d->bd_state = BPF_IDLE;
1273 BPFD_UNLOCK(d);
1274
1275 if (d->bd_locked == 1) {
1276 switch (cmd) {
1277 case BIOCGBLEN:
1278 case BIOCFLUSH:
1279 case BIOCGDLT:
1280 case BIOCGDLTLIST:
1281 #ifdef COMPAT_FREEBSD32
1282 case BIOCGDLTLIST32:
1283 #endif
1284 case BIOCGETIF:
1285 case BIOCGRTIMEOUT:
1286 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1287 case BIOCGRTIMEOUT32:
1288 #endif
1289 case BIOCGSTATS:
1290 case BIOCVERSION:
1291 case BIOCGRSIG:
1292 case BIOCGHDRCMPLT:
1293 case BIOCSTSTAMP:
1294 case BIOCFEEDBACK:
1295 case FIONREAD:
1296 case BIOCLOCK:
1297 case BIOCSRTIMEOUT:
1298 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1299 case BIOCSRTIMEOUT32:
1300 #endif
1301 case BIOCIMMEDIATE:
1302 case TIOCGPGRP:
1303 case BIOCROTZBUF:
1304 break;
1305 default:
1306 return (EPERM);
1307 }
1308 }
1309 #ifdef COMPAT_FREEBSD32
1310 /*
1311 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so
1312 * that it will get 32-bit packet headers.
1313 */
1314 switch (cmd) {
1315 case BIOCSETF32:
1316 case BIOCSETFNR32:
1317 case BIOCSETWF32:
1318 case BIOCGDLTLIST32:
1319 case BIOCGRTIMEOUT32:
1320 case BIOCSRTIMEOUT32:
1321 BPFD_LOCK(d);
1322 d->bd_compat32 = 1;
1323 BPFD_UNLOCK(d);
1324 }
1325 #endif
1326
1327 CURVNET_SET(TD_TO_VNET(td));
1328 switch (cmd) {
1329
1330 default:
1331 error = EINVAL;
1332 break;
1333
1334 /*
1335 * Check for read packet available.
1336 */
1337 case FIONREAD:
1338 {
1339 int n;
1340
1341 BPFD_LOCK(d);
1342 n = d->bd_slen;
1343 while (d->bd_hbuf_in_use)
1344 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
1345 PRINET, "bd_hbuf", 0);
1346 if (d->bd_hbuf)
1347 n += d->bd_hlen;
1348 BPFD_UNLOCK(d);
1349
1350 *(int *)addr = n;
1351 break;
1352 }
1353
1354 /*
1355 * Get buffer len [for read()].
1356 */
1357 case BIOCGBLEN:
1358 BPFD_LOCK(d);
1359 *(u_int *)addr = d->bd_bufsize;
1360 BPFD_UNLOCK(d);
1361 break;
1362
1363 /*
1364 * Set buffer length.
1365 */
1366 case BIOCSBLEN:
1367 error = bpf_ioctl_sblen(d, (u_int *)addr);
1368 break;
1369
1370 /*
1371 * Set link layer read filter.
1372 */
1373 case BIOCSETF:
1374 case BIOCSETFNR:
1375 case BIOCSETWF:
1376 #ifdef COMPAT_FREEBSD32
1377 case BIOCSETF32:
1378 case BIOCSETFNR32:
1379 case BIOCSETWF32:
1380 #endif
1381 error = bpf_setf(d, (struct bpf_program *)addr, cmd);
1382 break;
1383
1384 /*
1385 * Flush read packet buffer.
1386 */
1387 case BIOCFLUSH:
1388 BPFD_LOCK(d);
1389 reset_d(d);
1390 BPFD_UNLOCK(d);
1391 break;
1392
1393 /*
1394 * Put interface into promiscuous mode.
1395 */
1396 case BIOCPROMISC:
1397 if (d->bd_bif == NULL) {
1398 /*
1399 * No interface attached yet.
1400 */
1401 error = EINVAL;
1402 break;
1403 }
1404 if (d->bd_promisc == 0) {
1405 error = ifpromisc(d->bd_bif->bif_ifp, 1);
1406 if (error == 0)
1407 d->bd_promisc = 1;
1408 }
1409 break;
1410
1411 /*
1412 * Get current data link type.
1413 */
1414 case BIOCGDLT:
1415 BPF_LOCK();
1416 if (d->bd_bif == NULL)
1417 error = EINVAL;
1418 else
1419 *(u_int *)addr = d->bd_bif->bif_dlt;
1420 BPF_UNLOCK();
1421 break;
1422
1423 /*
1424 * Get a list of supported data link types.
1425 */
1426 #ifdef COMPAT_FREEBSD32
1427 case BIOCGDLTLIST32:
1428 {
1429 struct bpf_dltlist32 *list32;
1430 struct bpf_dltlist dltlist;
1431
1432 list32 = (struct bpf_dltlist32 *)addr;
1433 dltlist.bfl_len = list32->bfl_len;
1434 dltlist.bfl_list = PTRIN(list32->bfl_list);
1435 BPF_LOCK();
1436 if (d->bd_bif == NULL)
1437 error = EINVAL;
1438 else {
1439 error = bpf_getdltlist(d, &dltlist);
1440 if (error == 0)
1441 list32->bfl_len = dltlist.bfl_len;
1442 }
1443 BPF_UNLOCK();
1444 break;
1445 }
1446 #endif
1447
1448 case BIOCGDLTLIST:
1449 BPF_LOCK();
1450 if (d->bd_bif == NULL)
1451 error = EINVAL;
1452 else
1453 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
1454 BPF_UNLOCK();
1455 break;
1456
1457 /*
1458 * Set data link type.
1459 */
1460 case BIOCSDLT:
1461 BPF_LOCK();
1462 if (d->bd_bif == NULL)
1463 error = EINVAL;
1464 else
1465 error = bpf_setdlt(d, *(u_int *)addr);
1466 BPF_UNLOCK();
1467 break;
1468
1469 /*
1470 * Get interface name.
1471 */
1472 case BIOCGETIF:
1473 BPF_LOCK();
1474 if (d->bd_bif == NULL)
1475 error = EINVAL;
1476 else {
1477 struct ifnet *const ifp = d->bd_bif->bif_ifp;
1478 struct ifreq *const ifr = (struct ifreq *)addr;
1479
1480 strlcpy(ifr->ifr_name, ifp->if_xname,
1481 sizeof(ifr->ifr_name));
1482 }
1483 BPF_UNLOCK();
1484 break;
1485
1486 /*
1487 * Set interface.
1488 */
1489 case BIOCSETIF:
1490 {
1491 int alloc_buf, size;
1492
1493 /*
1494 * Behavior here depends on the buffering model. If
1495 * we're using kernel memory buffers, then we can
1496 * allocate them here. If we're using zero-copy,
1497 * then the user process must have registered buffers
1498 * by the time we get here.
1499 */
1500 alloc_buf = 0;
1501 BPFD_LOCK(d);
1502 if (d->bd_bufmode == BPF_BUFMODE_BUFFER &&
1503 d->bd_sbuf == NULL)
1504 alloc_buf = 1;
1505 BPFD_UNLOCK(d);
1506 if (alloc_buf) {
1507 size = d->bd_bufsize;
1508 error = bpf_buffer_ioctl_sblen(d, &size);
1509 if (error != 0)
1510 break;
1511 }
1512 BPF_LOCK();
1513 error = bpf_setif(d, (struct ifreq *)addr);
1514 BPF_UNLOCK();
1515 break;
1516 }
1517
1518 /*
1519 * Set read timeout.
1520 */
1521 case BIOCSRTIMEOUT:
1522 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1523 case BIOCSRTIMEOUT32:
1524 #endif
1525 {
1526 struct timeval *tv = (struct timeval *)addr;
1527 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1528 struct timeval32 *tv32;
1529 struct timeval tv64;
1530
1531 if (cmd == BIOCSRTIMEOUT32) {
1532 tv32 = (struct timeval32 *)addr;
1533 tv = &tv64;
1534 tv->tv_sec = tv32->tv_sec;
1535 tv->tv_usec = tv32->tv_usec;
1536 } else
1537 #endif
1538 tv = (struct timeval *)addr;
1539
1540 /*
1541 * Subtract 1 tick from tvtohz() since this isn't
1542 * a one-shot timer.
1543 */
1544 if ((error = itimerfix(tv)) == 0)
1545 d->bd_rtout = tvtohz(tv) - 1;
1546 break;
1547 }
1548
1549 /*
1550 * Get read timeout.
1551 */
1552 case BIOCGRTIMEOUT:
1553 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1554 case BIOCGRTIMEOUT32:
1555 #endif
1556 {
1557 struct timeval *tv;
1558 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1559 struct timeval32 *tv32;
1560 struct timeval tv64;
1561
1562 if (cmd == BIOCGRTIMEOUT32)
1563 tv = &tv64;
1564 else
1565 #endif
1566 tv = (struct timeval *)addr;
1567
1568 tv->tv_sec = d->bd_rtout / hz;
1569 tv->tv_usec = (d->bd_rtout % hz) * tick;
1570 #if defined(COMPAT_FREEBSD32) && !defined(__mips__)
1571 if (cmd == BIOCGRTIMEOUT32) {
1572 tv32 = (struct timeval32 *)addr;
1573 tv32->tv_sec = tv->tv_sec;
1574 tv32->tv_usec = tv->tv_usec;
1575 }
1576 #endif
1577
1578 break;
1579 }
1580
1581 /*
1582 * Get packet stats.
1583 */
1584 case BIOCGSTATS:
1585 {
1586 struct bpf_stat *bs = (struct bpf_stat *)addr;
1587
1588 /* XXXCSJP overflow */
1589 bs->bs_recv = d->bd_rcount;
1590 bs->bs_drop = d->bd_dcount;
1591 break;
1592 }
1593
1594 /*
1595 * Set immediate mode.
1596 */
1597 case BIOCIMMEDIATE:
1598 BPFD_LOCK(d);
1599 d->bd_immediate = *(u_int *)addr;
1600 BPFD_UNLOCK(d);
1601 break;
1602
1603 case BIOCVERSION:
1604 {
1605 struct bpf_version *bv = (struct bpf_version *)addr;
1606
1607 bv->bv_major = BPF_MAJOR_VERSION;
1608 bv->bv_minor = BPF_MINOR_VERSION;
1609 break;
1610 }
1611
1612 /*
1613 * Get "header already complete" flag
1614 */
1615 case BIOCGHDRCMPLT:
1616 BPFD_LOCK(d);
1617 *(u_int *)addr = d->bd_hdrcmplt;
1618 BPFD_UNLOCK(d);
1619 break;
1620
1621 /*
1622 * Set "header already complete" flag
1623 */
1624 case BIOCSHDRCMPLT:
1625 BPFD_LOCK(d);
1626 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
1627 BPFD_UNLOCK(d);
1628 break;
1629
1630 /*
1631 * Get packet direction flag
1632 */
1633 case BIOCGDIRECTION:
1634 BPFD_LOCK(d);
1635 *(u_int *)addr = d->bd_direction;
1636 BPFD_UNLOCK(d);
1637 break;
1638
1639 /*
1640 * Set packet direction flag
1641 */
1642 case BIOCSDIRECTION:
1643 {
1644 u_int direction;
1645
1646 direction = *(u_int *)addr;
1647 switch (direction) {
1648 case BPF_D_IN:
1649 case BPF_D_INOUT:
1650 case BPF_D_OUT:
1651 BPFD_LOCK(d);
1652 d->bd_direction = direction;
1653 BPFD_UNLOCK(d);
1654 break;
1655 default:
1656 error = EINVAL;
1657 }
1658 }
1659 break;
1660
1661 /*
1662 * Get packet timestamp format and resolution.
1663 */
1664 case BIOCGTSTAMP:
1665 BPFD_LOCK(d);
1666 *(u_int *)addr = d->bd_tstamp;
1667 BPFD_UNLOCK(d);
1668 break;
1669
1670 /*
1671 * Set packet timestamp format and resolution.
1672 */
1673 case BIOCSTSTAMP:
1674 {
1675 u_int func;
1676
1677 func = *(u_int *)addr;
1678 if (BPF_T_VALID(func))
1679 d->bd_tstamp = func;
1680 else
1681 error = EINVAL;
1682 }
1683 break;
1684
1685 case BIOCFEEDBACK:
1686 BPFD_LOCK(d);
1687 d->bd_feedback = *(u_int *)addr;
1688 BPFD_UNLOCK(d);
1689 break;
1690
1691 case BIOCLOCK:
1692 BPFD_LOCK(d);
1693 d->bd_locked = 1;
1694 BPFD_UNLOCK(d);
1695 break;
1696
1697 case FIONBIO: /* Non-blocking I/O */
1698 break;
1699
1700 case FIOASYNC: /* Send signal on receive packets */
1701 BPFD_LOCK(d);
1702 d->bd_async = *(int *)addr;
1703 BPFD_UNLOCK(d);
1704 break;
1705
1706 case FIOSETOWN:
1707 /*
1708 * XXX: Add some sort of locking here?
1709 * fsetown() can sleep.
1710 */
1711 error = fsetown(*(int *)addr, &d->bd_sigio);
1712 break;
1713
1714 case FIOGETOWN:
1715 BPFD_LOCK(d);
1716 *(int *)addr = fgetown(&d->bd_sigio);
1717 BPFD_UNLOCK(d);
1718 break;
1719
1720 /* This is deprecated, FIOSETOWN should be used instead. */
1721 case TIOCSPGRP:
1722 error = fsetown(-(*(int *)addr), &d->bd_sigio);
1723 break;
1724
1725 /* This is deprecated, FIOGETOWN should be used instead. */
1726 case TIOCGPGRP:
1727 *(int *)addr = -fgetown(&d->bd_sigio);
1728 break;
1729
1730 case BIOCSRSIG: /* Set receive signal */
1731 {
1732 u_int sig;
1733
1734 sig = *(u_int *)addr;
1735
1736 if (sig >= NSIG)
1737 error = EINVAL;
1738 else {
1739 BPFD_LOCK(d);
1740 d->bd_sig = sig;
1741 BPFD_UNLOCK(d);
1742 }
1743 break;
1744 }
1745 case BIOCGRSIG:
1746 BPFD_LOCK(d);
1747 *(u_int *)addr = d->bd_sig;
1748 BPFD_UNLOCK(d);
1749 break;
1750
1751 case BIOCGETBUFMODE:
1752 BPFD_LOCK(d);
1753 *(u_int *)addr = d->bd_bufmode;
1754 BPFD_UNLOCK(d);
1755 break;
1756
1757 case BIOCSETBUFMODE:
1758 /*
1759 * Allow the buffering mode to be changed as long as we
1760 * haven't yet committed to a particular mode. Our
1761 * definition of commitment, for now, is whether or not a
1762 * buffer has been allocated or an interface attached, since
1763 * that's the point where things get tricky.
1764 */
1765 switch (*(u_int *)addr) {
1766 case BPF_BUFMODE_BUFFER:
1767 break;
1768
1769 case BPF_BUFMODE_ZBUF:
1770 if (bpf_zerocopy_enable)
1771 break;
1772 /* FALLSTHROUGH */
1773
1774 default:
1775 CURVNET_RESTORE();
1776 return (EINVAL);
1777 }
1778
1779 BPFD_LOCK(d);
1780 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL ||
1781 d->bd_fbuf != NULL || d->bd_bif != NULL) {
1782 BPFD_UNLOCK(d);
1783 CURVNET_RESTORE();
1784 return (EBUSY);
1785 }
1786 d->bd_bufmode = *(u_int *)addr;
1787 BPFD_UNLOCK(d);
1788 break;
1789
1790 case BIOCGETZMAX:
1791 error = bpf_ioctl_getzmax(td, d, (size_t *)addr);
1792 break;
1793
1794 case BIOCSETZBUF:
1795 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr);
1796 break;
1797
1798 case BIOCROTZBUF:
1799 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr);
1800 break;
1801 }
1802 CURVNET_RESTORE();
1803 return (error);
1804 }
1805
1806 /*
1807 * Set d's packet filter program to fp. If this file already has a filter,
1808 * free it and replace it. Returns EINVAL for bogus requests.
1809 *
1810 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls
1811 * since reading d->bd_bif can't be protected by d or interface lock due to
1812 * lock order.
1813 *
1814 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses
1815 * interface read lock to read all filers.
1816 *
1817 */
1818 static int
1819 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1820 {
1821 #ifdef COMPAT_FREEBSD32
1822 struct bpf_program fp_swab;
1823 struct bpf_program32 *fp32;
1824 #endif
1825 struct bpf_insn *fcode, *old;
1826 #ifdef BPF_JITTER
1827 bpf_jit_filter *jfunc, *ofunc;
1828 #endif
1829 size_t size;
1830 u_int flen;
1831 int need_upgrade;
1832
1833 #ifdef COMPAT_FREEBSD32
1834 switch (cmd) {
1835 case BIOCSETF32:
1836 case BIOCSETWF32:
1837 case BIOCSETFNR32:
1838 fp32 = (struct bpf_program32 *)fp;
1839 fp_swab.bf_len = fp32->bf_len;
1840 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns;
1841 fp = &fp_swab;
1842 switch (cmd) {
1843 case BIOCSETF32:
1844 cmd = BIOCSETF;
1845 break;
1846 case BIOCSETWF32:
1847 cmd = BIOCSETWF;
1848 break;
1849 }
1850 break;
1851 }
1852 #endif
1853
1854 fcode = NULL;
1855 #ifdef BPF_JITTER
1856 jfunc = ofunc = NULL;
1857 #endif
1858 need_upgrade = 0;
1859
1860 /*
1861 * Check new filter validness before acquiring any locks.
1862 * Allocate memory for new filter, if needed.
1863 */
1864 flen = fp->bf_len;
1865 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0))
1866 return (EINVAL);
1867 size = flen * sizeof(*fp->bf_insns);
1868 if (size > 0) {
1869 /* We're setting up new filter. Copy and check actual data. */
1870 fcode = malloc(size, M_BPF, M_WAITOK);
1871 if (copyin(fp->bf_insns, fcode, size) != 0 ||
1872 !bpf_validate(fcode, flen)) {
1873 free(fcode, M_BPF);
1874 return (EINVAL);
1875 }
1876 #ifdef BPF_JITTER
1877 /* Filter is copied inside fcode and is perfectly valid. */
1878 jfunc = bpf_jitter(fcode, flen);
1879 #endif
1880 }
1881
1882 BPF_LOCK();
1883
1884 /*
1885 * Set up new filter.
1886 * Protect filter change by interface lock.
1887 * Additionally, we are protected by global lock here.
1888 */
1889 if (d->bd_bif != NULL)
1890 BPFIF_WLOCK(d->bd_bif);
1891 BPFD_LOCK(d);
1892 if (cmd == BIOCSETWF) {
1893 old = d->bd_wfilter;
1894 d->bd_wfilter = fcode;
1895 } else {
1896 old = d->bd_rfilter;
1897 d->bd_rfilter = fcode;
1898 #ifdef BPF_JITTER
1899 ofunc = d->bd_bfilter;
1900 d->bd_bfilter = jfunc;
1901 #endif
1902 if (cmd == BIOCSETF)
1903 reset_d(d);
1904
1905 need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen);
1906 }
1907 BPFD_UNLOCK(d);
1908 if (d->bd_bif != NULL)
1909 BPFIF_WUNLOCK(d->bd_bif);
1910 if (old != NULL)
1911 free(old, M_BPF);
1912 #ifdef BPF_JITTER
1913 if (ofunc != NULL)
1914 bpf_destroy_jit_filter(ofunc);
1915 #endif
1916
1917 /* Move d to active readers list. */
1918 if (need_upgrade != 0)
1919 bpf_upgraded(d);
1920
1921 BPF_UNLOCK();
1922 return (0);
1923 }
1924
1925 /*
1926 * Detach a file from its current interface (if attached at all) and attach
1927 * to the interface indicated by the name stored in ifr.
1928 * Return an errno or 0.
1929 */
1930 static int
1931 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1932 {
1933 struct bpf_if *bp;
1934 struct ifnet *theywant;
1935
1936 BPF_LOCK_ASSERT();
1937
1938 theywant = ifunit(ifr->ifr_name);
1939 if (theywant == NULL || theywant->if_bpf == NULL)
1940 return (ENXIO);
1941
1942 bp = theywant->if_bpf;
1943
1944 /* Check if interface is not being detached from BPF */
1945 BPFIF_RLOCK(bp);
1946 if (bp->bif_flags & BPFIF_FLAG_DYING) {
1947 BPFIF_RUNLOCK(bp);
1948 return (ENXIO);
1949 }
1950 BPFIF_RUNLOCK(bp);
1951
1952 /*
1953 * At this point, we expect the buffer is already allocated. If not,
1954 * return an error.
1955 */
1956 switch (d->bd_bufmode) {
1957 case BPF_BUFMODE_BUFFER:
1958 case BPF_BUFMODE_ZBUF:
1959 if (d->bd_sbuf == NULL)
1960 return (EINVAL);
1961 break;
1962
1963 default:
1964 panic("bpf_setif: bufmode %d", d->bd_bufmode);
1965 }
1966 if (bp != d->bd_bif)
1967 bpf_attachd(d, bp);
1968 BPFD_LOCK(d);
1969 reset_d(d);
1970 BPFD_UNLOCK(d);
1971 return (0);
1972 }
1973
1974 /*
1975 * Support for select() and poll() system calls
1976 *
1977 * Return true iff the specific operation will not block indefinitely.
1978 * Otherwise, return false but make a note that a selwakeup() must be done.
1979 */
1980 static int
1981 bpfpoll(struct cdev *dev, int events, struct thread *td)
1982 {
1983 struct bpf_d *d;
1984 int revents;
1985
1986 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL)
1987 return (events &
1988 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
1989
1990 /*
1991 * Refresh PID associated with this descriptor.
1992 */
1993 revents = events & (POLLOUT | POLLWRNORM);
1994 BPFD_LOCK(d);
1995 BPF_PID_REFRESH(d, td);
1996 if (events & (POLLIN | POLLRDNORM)) {
1997 if (bpf_ready(d))
1998 revents |= events & (POLLIN | POLLRDNORM);
1999 else {
2000 selrecord(td, &d->bd_sel);
2001 /* Start the read timeout if necessary. */
2002 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
2003 callout_reset(&d->bd_callout, d->bd_rtout,
2004 bpf_timed_out, d);
2005 d->bd_state = BPF_WAITING;
2006 }
2007 }
2008 }
2009 BPFD_UNLOCK(d);
2010 return (revents);
2011 }
2012
2013 /*
2014 * Support for kevent() system call. Register EVFILT_READ filters and
2015 * reject all others.
2016 */
2017 int
2018 bpfkqfilter(struct cdev *dev, struct knote *kn)
2019 {
2020 struct bpf_d *d;
2021
2022 if (devfs_get_cdevpriv((void **)&d) != 0 ||
2023 kn->kn_filter != EVFILT_READ)
2024 return (1);
2025
2026 /*
2027 * Refresh PID associated with this descriptor.
2028 */
2029 BPFD_LOCK(d);
2030 BPF_PID_REFRESH_CUR(d);
2031 kn->kn_fop = &bpfread_filtops;
2032 kn->kn_hook = d;
2033 knlist_add(&d->bd_sel.si_note, kn, 1);
2034 BPFD_UNLOCK(d);
2035
2036 return (0);
2037 }
2038
2039 static void
2040 filt_bpfdetach(struct knote *kn)
2041 {
2042 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
2043
2044 knlist_remove(&d->bd_sel.si_note, kn, 0);
2045 }
2046
2047 static int
2048 filt_bpfread(struct knote *kn, long hint)
2049 {
2050 struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
2051 int ready;
2052
2053 BPFD_LOCK_ASSERT(d);
2054 ready = bpf_ready(d);
2055 if (ready) {
2056 kn->kn_data = d->bd_slen;
2057 /*
2058 * Ignore the hold buffer if it is being copied to user space.
2059 */
2060 if (!d->bd_hbuf_in_use && d->bd_hbuf)
2061 kn->kn_data += d->bd_hlen;
2062 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
2063 callout_reset(&d->bd_callout, d->bd_rtout,
2064 bpf_timed_out, d);
2065 d->bd_state = BPF_WAITING;
2066 }
2067
2068 return (ready);
2069 }
2070
2071 #define BPF_TSTAMP_NONE 0
2072 #define BPF_TSTAMP_FAST 1
2073 #define BPF_TSTAMP_NORMAL 2
2074 #define BPF_TSTAMP_EXTERN 3
2075
2076 static int
2077 bpf_ts_quality(int tstype)
2078 {
2079
2080 if (tstype == BPF_T_NONE)
2081 return (BPF_TSTAMP_NONE);
2082 if ((tstype & BPF_T_FAST) != 0)
2083 return (BPF_TSTAMP_FAST);
2084
2085 return (BPF_TSTAMP_NORMAL);
2086 }
2087
2088 static int
2089 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m)
2090 {
2091 struct m_tag *tag;
2092 int quality;
2093
2094 quality = bpf_ts_quality(tstype);
2095 if (quality == BPF_TSTAMP_NONE)
2096 return (quality);
2097
2098 if (m != NULL) {
2099 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL);
2100 if (tag != NULL) {
2101 *bt = *(struct bintime *)(tag + 1);
2102 return (BPF_TSTAMP_EXTERN);
2103 }
2104 }
2105 if (quality == BPF_TSTAMP_NORMAL)
2106 binuptime(bt);
2107 else
2108 getbinuptime(bt);
2109
2110 return (quality);
2111 }
2112
2113 /*
2114 * Incoming linkage from device drivers. Process the packet pkt, of length
2115 * pktlen, which is stored in a contiguous buffer. The packet is parsed
2116 * by each process' filter, and if accepted, stashed into the corresponding
2117 * buffer.
2118 */
2119 void
2120 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2121 {
2122 struct bintime bt;
2123 struct bpf_d *d;
2124 #ifdef BPF_JITTER
2125 bpf_jit_filter *bf;
2126 #endif
2127 u_int slen;
2128 int gottime;
2129
2130 gottime = BPF_TSTAMP_NONE;
2131
2132 BPFIF_RLOCK(bp);
2133
2134 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2135 /*
2136 * We are not using any locks for d here because:
2137 * 1) any filter change is protected by interface
2138 * write lock
2139 * 2) destroying/detaching d is protected by interface
2140 * write lock, too
2141 */
2142
2143 /* XXX: Do not protect counter for the sake of performance. */
2144 ++d->bd_rcount;
2145 /*
2146 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no
2147 * way for the caller to indiciate to us whether this packet
2148 * is inbound or outbound. In the bpf_mtap() routines, we use
2149 * the interface pointers on the mbuf to figure it out.
2150 */
2151 #ifdef BPF_JITTER
2152 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2153 if (bf != NULL)
2154 slen = (*(bf->func))(pkt, pktlen, pktlen);
2155 else
2156 #endif
2157 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
2158 if (slen != 0) {
2159 /*
2160 * Filter matches. Let's to acquire write lock.
2161 */
2162 BPFD_LOCK(d);
2163
2164 d->bd_fcount++;
2165 if (gottime < bpf_ts_quality(d->bd_tstamp))
2166 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL);
2167 #ifdef MAC
2168 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2169 #endif
2170 catchpacket(d, pkt, pktlen, slen,
2171 bpf_append_bytes, &bt);
2172 BPFD_UNLOCK(d);
2173 }
2174 }
2175 BPFIF_RUNLOCK(bp);
2176 }
2177
2178 #define BPF_CHECK_DIRECTION(d, r, i) \
2179 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \
2180 ((d)->bd_direction == BPF_D_OUT && (r) == (i)))
2181
2182 /*
2183 * Incoming linkage from device drivers, when packet is in an mbuf chain.
2184 * Locking model is explained in bpf_tap().
2185 */
2186 void
2187 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2188 {
2189 struct bintime bt;
2190 struct bpf_d *d;
2191 #ifdef BPF_JITTER
2192 bpf_jit_filter *bf;
2193 #endif
2194 u_int pktlen, slen;
2195 int gottime;
2196
2197 /* Skip outgoing duplicate packets. */
2198 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2199 m->m_flags &= ~M_PROMISC;
2200 return;
2201 }
2202
2203 pktlen = m_length(m, NULL);
2204 gottime = BPF_TSTAMP_NONE;
2205
2206 BPFIF_RLOCK(bp);
2207
2208 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2209 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2210 continue;
2211 ++d->bd_rcount;
2212 #ifdef BPF_JITTER
2213 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
2214 /* XXX We cannot handle multiple mbufs. */
2215 if (bf != NULL && m->m_next == NULL)
2216 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen);
2217 else
2218 #endif
2219 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
2220 if (slen != 0) {
2221 BPFD_LOCK(d);
2222
2223 d->bd_fcount++;
2224 if (gottime < bpf_ts_quality(d->bd_tstamp))
2225 gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2226 #ifdef MAC
2227 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2228 #endif
2229 catchpacket(d, (u_char *)m, pktlen, slen,
2230 bpf_append_mbuf, &bt);
2231 BPFD_UNLOCK(d);
2232 }
2233 }
2234 BPFIF_RUNLOCK(bp);
2235 }
2236
2237 /*
2238 * Incoming linkage from device drivers, when packet is in
2239 * an mbuf chain and to be prepended by a contiguous header.
2240 */
2241 void
2242 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
2243 {
2244 struct bintime bt;
2245 struct mbuf mb;
2246 struct bpf_d *d;
2247 u_int pktlen, slen;
2248 int gottime;
2249
2250 /* Skip outgoing duplicate packets. */
2251 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
2252 m->m_flags &= ~M_PROMISC;
2253 return;
2254 }
2255
2256 pktlen = m_length(m, NULL);
2257 /*
2258 * Craft on-stack mbuf suitable for passing to bpf_filter.
2259 * Note that we cut corners here; we only setup what's
2260 * absolutely needed--this mbuf should never go anywhere else.
2261 */
2262 mb.m_next = m;
2263 mb.m_data = data;
2264 mb.m_len = dlen;
2265 pktlen += dlen;
2266
2267 gottime = BPF_TSTAMP_NONE;
2268
2269 BPFIF_RLOCK(bp);
2270
2271 LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
2272 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
2273 continue;
2274 ++d->bd_rcount;
2275 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0);
2276 if (slen != 0) {
2277 BPFD_LOCK(d);
2278
2279 d->bd_fcount++;
2280 if (gottime < bpf_ts_quality(d->bd_tstamp))
2281 gottime = bpf_gettime(&bt, d->bd_tstamp, m);
2282 #ifdef MAC
2283 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
2284 #endif
2285 catchpacket(d, (u_char *)&mb, pktlen, slen,
2286 bpf_append_mbuf, &bt);
2287 BPFD_UNLOCK(d);
2288 }
2289 }
2290 BPFIF_RUNLOCK(bp);
2291 }
2292
2293 #undef BPF_CHECK_DIRECTION
2294
2295 #undef BPF_TSTAMP_NONE
2296 #undef BPF_TSTAMP_FAST
2297 #undef BPF_TSTAMP_NORMAL
2298 #undef BPF_TSTAMP_EXTERN
2299
2300 static int
2301 bpf_hdrlen(struct bpf_d *d)
2302 {
2303 int hdrlen;
2304
2305 hdrlen = d->bd_bif->bif_hdrlen;
2306 #ifndef BURN_BRIDGES
2307 if (d->bd_tstamp == BPF_T_NONE ||
2308 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME)
2309 #ifdef COMPAT_FREEBSD32
2310 if (d->bd_compat32)
2311 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32);
2312 else
2313 #endif
2314 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr);
2315 else
2316 #endif
2317 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr);
2318 #ifdef COMPAT_FREEBSD32
2319 if (d->bd_compat32)
2320 hdrlen = BPF_WORDALIGN32(hdrlen);
2321 else
2322 #endif
2323 hdrlen = BPF_WORDALIGN(hdrlen);
2324
2325 return (hdrlen - d->bd_bif->bif_hdrlen);
2326 }
2327
2328 static void
2329 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype)
2330 {
2331 struct bintime bt2;
2332 struct timeval tsm;
2333 struct timespec tsn;
2334
2335 if ((tstype & BPF_T_MONOTONIC) == 0) {
2336 bt2 = *bt;
2337 bintime_add(&bt2, &boottimebin);
2338 bt = &bt2;
2339 }
2340 switch (BPF_T_FORMAT(tstype)) {
2341 case BPF_T_MICROTIME:
2342 bintime2timeval(bt, &tsm);
2343 ts->bt_sec = tsm.tv_sec;
2344 ts->bt_frac = tsm.tv_usec;
2345 break;
2346 case BPF_T_NANOTIME:
2347 bintime2timespec(bt, &tsn);
2348 ts->bt_sec = tsn.tv_sec;
2349 ts->bt_frac = tsn.tv_nsec;
2350 break;
2351 case BPF_T_BINTIME:
2352 ts->bt_sec = bt->sec;
2353 ts->bt_frac = bt->frac;
2354 break;
2355 }
2356 }
2357
2358 /*
2359 * Move the packet data from interface memory (pkt) into the
2360 * store buffer. "cpfn" is the routine called to do the actual data
2361 * transfer. bcopy is passed in to copy contiguous chunks, while
2362 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case,
2363 * pkt is really an mbuf.
2364 */
2365 static void
2366 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
2367 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int),
2368 struct bintime *bt)
2369 {
2370 struct bpf_xhdr hdr;
2371 #ifndef BURN_BRIDGES
2372 struct bpf_hdr hdr_old;
2373 #ifdef COMPAT_FREEBSD32
2374 struct bpf_hdr32 hdr32_old;
2375 #endif
2376 #endif
2377 int caplen, curlen, hdrlen, totlen;
2378 int do_wakeup = 0;
2379 int do_timestamp;
2380 int tstype;
2381
2382 BPFD_LOCK_ASSERT(d);
2383
2384 /*
2385 * Detect whether user space has released a buffer back to us, and if
2386 * so, move it from being a hold buffer to a free buffer. This may
2387 * not be the best place to do it (for example, we might only want to
2388 * run this check if we need the space), but for now it's a reliable
2389 * spot to do it.
2390 */
2391 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) {
2392 d->bd_fbuf = d->bd_hbuf;
2393 d->bd_hbuf = NULL;
2394 d->bd_hlen = 0;
2395 bpf_buf_reclaimed(d);
2396 }
2397
2398 /*
2399 * Figure out how many bytes to move. If the packet is
2400 * greater or equal to the snapshot length, transfer that
2401 * much. Otherwise, transfer the whole packet (unless
2402 * we hit the buffer size limit).
2403 */
2404 hdrlen = bpf_hdrlen(d);
2405 totlen = hdrlen + min(snaplen, pktlen);
2406 if (totlen > d->bd_bufsize)
2407 totlen = d->bd_bufsize;
2408
2409 /*
2410 * Round up the end of the previous packet to the next longword.
2411 *
2412 * Drop the packet if there's no room and no hope of room
2413 * If the packet would overflow the storage buffer or the storage
2414 * buffer is considered immutable by the buffer model, try to rotate
2415 * the buffer and wakeup pending processes.
2416 */
2417 #ifdef COMPAT_FREEBSD32
2418 if (d->bd_compat32)
2419 curlen = BPF_WORDALIGN32(d->bd_slen);
2420 else
2421 #endif
2422 curlen = BPF_WORDALIGN(d->bd_slen);
2423 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) {
2424 if (d->bd_fbuf == NULL) {
2425 /*
2426 * There's no room in the store buffer, and no
2427 * prospect of room, so drop the packet. Notify the
2428 * buffer model.
2429 */
2430 bpf_buffull(d);
2431 ++d->bd_dcount;
2432 return;
2433 }
2434 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use"));
2435 ROTATE_BUFFERS(d);
2436 do_wakeup = 1;
2437 curlen = 0;
2438 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT)
2439 /*
2440 * Immediate mode is set, or the read timeout has already
2441 * expired during a select call. A packet arrived, so the
2442 * reader should be woken up.
2443 */
2444 do_wakeup = 1;
2445 caplen = totlen - hdrlen;
2446 tstype = d->bd_tstamp;
2447 do_timestamp = tstype != BPF_T_NONE;
2448 #ifndef BURN_BRIDGES
2449 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) {
2450 struct bpf_ts ts;
2451 if (do_timestamp)
2452 bpf_bintime2ts(bt, &ts, tstype);
2453 #ifdef COMPAT_FREEBSD32
2454 if (d->bd_compat32) {
2455 bzero(&hdr32_old, sizeof(hdr32_old));
2456 if (do_timestamp) {
2457 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec;
2458 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac;
2459 }
2460 hdr32_old.bh_datalen = pktlen;
2461 hdr32_old.bh_hdrlen = hdrlen;
2462 hdr32_old.bh_caplen = caplen;
2463 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old,
2464 sizeof(hdr32_old));
2465 goto copy;
2466 }
2467 #endif
2468 bzero(&hdr_old, sizeof(hdr_old));
2469 if (do_timestamp) {
2470 hdr_old.bh_tstamp.tv_sec = ts.bt_sec;
2471 hdr_old.bh_tstamp.tv_usec = ts.bt_frac;
2472 }
2473 hdr_old.bh_datalen = pktlen;
2474 hdr_old.bh_hdrlen = hdrlen;
2475 hdr_old.bh_caplen = caplen;
2476 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old,
2477 sizeof(hdr_old));
2478 goto copy;
2479 }
2480 #endif
2481
2482 /*
2483 * Append the bpf header. Note we append the actual header size, but
2484 * move forward the length of the header plus padding.
2485 */
2486 bzero(&hdr, sizeof(hdr));
2487 if (do_timestamp)
2488 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype);
2489 hdr.bh_datalen = pktlen;
2490 hdr.bh_hdrlen = hdrlen;
2491 hdr.bh_caplen = caplen;
2492 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr));
2493
2494 /*
2495 * Copy the packet data into the store buffer and update its length.
2496 */
2497 #ifndef BURN_BRIDGES
2498 copy:
2499 #endif
2500 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen);
2501 d->bd_slen = curlen + totlen;
2502
2503 if (do_wakeup)
2504 bpf_wakeup(d);
2505 }
2506
2507 /*
2508 * Free buffers currently in use by a descriptor.
2509 * Called on close.
2510 */
2511 static void
2512 bpf_freed(struct bpf_d *d)
2513 {
2514
2515 /*
2516 * We don't need to lock out interrupts since this descriptor has
2517 * been detached from its interface and it yet hasn't been marked
2518 * free.
2519 */
2520 bpf_free(d);
2521 if (d->bd_rfilter != NULL) {
2522 free((caddr_t)d->bd_rfilter, M_BPF);
2523 #ifdef BPF_JITTER
2524 if (d->bd_bfilter != NULL)
2525 bpf_destroy_jit_filter(d->bd_bfilter);
2526 #endif
2527 }
2528 if (d->bd_wfilter != NULL)
2529 free((caddr_t)d->bd_wfilter, M_BPF);
2530 mtx_destroy(&d->bd_lock);
2531 }
2532
2533 /*
2534 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the
2535 * fixed size of the link header (variable length headers not yet supported).
2536 */
2537 void
2538 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2539 {
2540
2541 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2542 }
2543
2544 /*
2545 * Attach an interface to bpf. ifp is a pointer to the structure
2546 * defining the interface to be attached, dlt is the link layer type,
2547 * and hdrlen is the fixed size of the link header (variable length
2548 * headers are not yet supporrted).
2549 */
2550 void
2551 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2552 {
2553 struct bpf_if *bp;
2554
2555 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
2556 if (bp == NULL)
2557 panic("bpfattach");
2558
2559 LIST_INIT(&bp->bif_dlist);
2560 LIST_INIT(&bp->bif_wlist);
2561 bp->bif_ifp = ifp;
2562 bp->bif_dlt = dlt;
2563 rw_init(&bp->bif_lock, "bpf interface lock");
2564 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
2565 *driverp = bp;
2566
2567 BPF_LOCK();
2568 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
2569 BPF_UNLOCK();
2570
2571 bp->bif_hdrlen = hdrlen;
2572
2573 if (bootverbose && IS_DEFAULT_VNET(curvnet))
2574 if_printf(ifp, "bpf attached\n");
2575 }
2576
2577 #ifdef VIMAGE
2578 /*
2579 * When moving interfaces between vnet instances we need a way to
2580 * query the dlt and hdrlen before detach so we can re-attch the if_bpf
2581 * after the vmove. We unfortunately have no device driver infrastructure
2582 * to query the interface for these values after creation/attach, thus
2583 * add this as a workaround.
2584 */
2585 int
2586 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen)
2587 {
2588
2589 if (bp == NULL)
2590 return (ENXIO);
2591 if (bif_dlt == NULL && bif_hdrlen == NULL)
2592 return (0);
2593
2594 if (bif_dlt != NULL)
2595 *bif_dlt = bp->bif_dlt;
2596 if (bif_hdrlen != NULL)
2597 *bif_hdrlen = bp->bif_hdrlen;
2598
2599 return (0);
2600 }
2601 #endif
2602
2603 /*
2604 * Detach bpf from an interface. This involves detaching each descriptor
2605 * associated with the interface. Notify each descriptor as it's detached
2606 * so that any sleepers wake up and get ENXIO.
2607 */
2608 void
2609 bpfdetach(struct ifnet *ifp)
2610 {
2611 struct bpf_if *bp, *bp_temp;
2612 struct bpf_d *d;
2613 int ndetached;
2614
2615 ndetached = 0;
2616
2617 BPF_LOCK();
2618 /* Find all bpf_if struct's which reference ifp and detach them. */
2619 LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) {
2620 if (ifp != bp->bif_ifp)
2621 continue;
2622
2623 LIST_REMOVE(bp, bif_next);
2624 /* Add to to-be-freed list */
2625 LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next);
2626
2627 ndetached++;
2628 /*
2629 * Delay freeing bp till interface is detached
2630 * and all routes through this interface are removed.
2631 * Mark bp as detached to restrict new consumers.
2632 */
2633 BPFIF_WLOCK(bp);
2634 bp->bif_flags |= BPFIF_FLAG_DYING;
2635 BPFIF_WUNLOCK(bp);
2636
2637 CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p",
2638 __func__, bp->bif_dlt, bp, ifp);
2639
2640 /* Free common descriptors */
2641 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
2642 bpf_detachd_locked(d);
2643 BPFD_LOCK(d);
2644 bpf_wakeup(d);
2645 BPFD_UNLOCK(d);
2646 }
2647
2648 /* Free writer-only descriptors */
2649 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) {
2650 bpf_detachd_locked(d);
2651 BPFD_LOCK(d);
2652 bpf_wakeup(d);
2653 BPFD_UNLOCK(d);
2654 }
2655 }
2656 BPF_UNLOCK();
2657
2658 #ifdef INVARIANTS
2659 if (ndetached == 0)
2660 printf("bpfdetach: %s was not attached\n", ifp->if_xname);
2661 #endif
2662 }
2663
2664 /*
2665 * Interface departure handler.
2666 * Note departure event does not guarantee interface is going down.
2667 * Interface renaming is currently done via departure/arrival event set.
2668 *
2669 * Departure handled is called after all routes pointing to
2670 * given interface are removed and interface is in down state
2671 * restricting any packets to be sent/received. We assume it is now safe
2672 * to free data allocated by BPF.
2673 */
2674 static void
2675 bpf_ifdetach(void *arg __unused, struct ifnet *ifp)
2676 {
2677 struct bpf_if *bp, *bp_temp;
2678 int nmatched = 0;
2679
2680 BPF_LOCK();
2681 /*
2682 * Find matching entries in free list.
2683 * Nothing should be found if bpfdetach() was not called.
2684 */
2685 LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) {
2686 if (ifp != bp->bif_ifp)
2687 continue;
2688
2689 CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p",
2690 __func__, bp, ifp);
2691
2692 LIST_REMOVE(bp, bif_next);
2693
2694 rw_destroy(&bp->bif_lock);
2695 free(bp, M_BPF);
2696
2697 nmatched++;
2698 }
2699 BPF_UNLOCK();
2700
2701 /*
2702 * Note that we cannot zero other pointers to
2703 * custom DLTs possibly used by given interface.
2704 */
2705 if (nmatched != 0)
2706 ifp->if_bpf = NULL;
2707 }
2708
2709 /*
2710 * Get a list of available data link type of the interface.
2711 */
2712 static int
2713 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
2714 {
2715 struct ifnet *ifp;
2716 struct bpf_if *bp;
2717 u_int *lst;
2718 int error, n, n1;
2719
2720 BPF_LOCK_ASSERT();
2721
2722 ifp = d->bd_bif->bif_ifp;
2723 again:
2724 n1 = 0;
2725 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2726 if (bp->bif_ifp == ifp)
2727 n1++;
2728 }
2729 if (bfl->bfl_list == NULL) {
2730 bfl->bfl_len = n1;
2731 return (0);
2732 }
2733 if (n1 > bfl->bfl_len)
2734 return (ENOMEM);
2735 BPF_UNLOCK();
2736 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK);
2737 n = 0;
2738 BPF_LOCK();
2739 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2740 if (bp->bif_ifp != ifp)
2741 continue;
2742 if (n >= n1) {
2743 free(lst, M_TEMP);
2744 goto again;
2745 }
2746 lst[n] = bp->bif_dlt;
2747 n++;
2748 }
2749 BPF_UNLOCK();
2750 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n);
2751 free(lst, M_TEMP);
2752 BPF_LOCK();
2753 bfl->bfl_len = n;
2754 return (error);
2755 }
2756
2757 /*
2758 * Set the data link type of a BPF instance.
2759 */
2760 static int
2761 bpf_setdlt(struct bpf_d *d, u_int dlt)
2762 {
2763 int error, opromisc;
2764 struct ifnet *ifp;
2765 struct bpf_if *bp;
2766
2767 BPF_LOCK_ASSERT();
2768
2769 if (d->bd_bif->bif_dlt == dlt)
2770 return (0);
2771 ifp = d->bd_bif->bif_ifp;
2772
2773 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2774 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
2775 break;
2776 }
2777
2778 if (bp != NULL) {
2779 opromisc = d->bd_promisc;
2780 bpf_attachd(d, bp);
2781 BPFD_LOCK(d);
2782 reset_d(d);
2783 BPFD_UNLOCK(d);
2784 if (opromisc) {
2785 error = ifpromisc(bp->bif_ifp, 1);
2786 if (error)
2787 if_printf(bp->bif_ifp,
2788 "bpf_setdlt: ifpromisc failed (%d)\n",
2789 error);
2790 else
2791 d->bd_promisc = 1;
2792 }
2793 }
2794 return (bp == NULL ? EINVAL : 0);
2795 }
2796
2797 static void
2798 bpf_drvinit(void *unused)
2799 {
2800 struct cdev *dev;
2801
2802 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
2803 LIST_INIT(&bpf_iflist);
2804 LIST_INIT(&bpf_freelist);
2805
2806 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf");
2807 /* For compatibility */
2808 make_dev_alias(dev, "bpf0");
2809
2810 /* Register interface departure handler */
2811 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER(
2812 ifnet_departure_event, bpf_ifdetach, NULL,
2813 EVENTHANDLER_PRI_ANY);
2814 }
2815
2816 /*
2817 * Zero out the various packet counters associated with all of the bpf
2818 * descriptors. At some point, we will probably want to get a bit more
2819 * granular and allow the user to specify descriptors to be zeroed.
2820 */
2821 static void
2822 bpf_zero_counters(void)
2823 {
2824 struct bpf_if *bp;
2825 struct bpf_d *bd;
2826
2827 BPF_LOCK();
2828 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2829 BPFIF_RLOCK(bp);
2830 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2831 BPFD_LOCK(bd);
2832 bd->bd_rcount = 0;
2833 bd->bd_dcount = 0;
2834 bd->bd_fcount = 0;
2835 bd->bd_wcount = 0;
2836 bd->bd_wfcount = 0;
2837 bd->bd_zcopy = 0;
2838 BPFD_UNLOCK(bd);
2839 }
2840 BPFIF_RUNLOCK(bp);
2841 }
2842 BPF_UNLOCK();
2843 }
2844
2845 /*
2846 * Fill filter statistics
2847 */
2848 static void
2849 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
2850 {
2851
2852 bzero(d, sizeof(*d));
2853 BPFD_LOCK_ASSERT(bd);
2854 d->bd_structsize = sizeof(*d);
2855 /* XXX: reading should be protected by global lock */
2856 d->bd_immediate = bd->bd_immediate;
2857 d->bd_promisc = bd->bd_promisc;
2858 d->bd_hdrcmplt = bd->bd_hdrcmplt;
2859 d->bd_direction = bd->bd_direction;
2860 d->bd_feedback = bd->bd_feedback;
2861 d->bd_async = bd->bd_async;
2862 d->bd_rcount = bd->bd_rcount;
2863 d->bd_dcount = bd->bd_dcount;
2864 d->bd_fcount = bd->bd_fcount;
2865 d->bd_sig = bd->bd_sig;
2866 d->bd_slen = bd->bd_slen;
2867 d->bd_hlen = bd->bd_hlen;
2868 d->bd_bufsize = bd->bd_bufsize;
2869 d->bd_pid = bd->bd_pid;
2870 strlcpy(d->bd_ifname,
2871 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
2872 d->bd_locked = bd->bd_locked;
2873 d->bd_wcount = bd->bd_wcount;
2874 d->bd_wdcount = bd->bd_wdcount;
2875 d->bd_wfcount = bd->bd_wfcount;
2876 d->bd_zcopy = bd->bd_zcopy;
2877 d->bd_bufmode = bd->bd_bufmode;
2878 }
2879
2880 /*
2881 * Handle `netstat -B' stats request
2882 */
2883 static int
2884 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS)
2885 {
2886 static const struct xbpf_d zerostats;
2887 struct xbpf_d *xbdbuf, *xbd, tempstats;
2888 int index, error;
2889 struct bpf_if *bp;
2890 struct bpf_d *bd;
2891
2892 /*
2893 * XXX This is not technically correct. It is possible for non
2894 * privileged users to open bpf devices. It would make sense
2895 * if the users who opened the devices were able to retrieve
2896 * the statistics for them, too.
2897 */
2898 error = priv_check(req->td, PRIV_NET_BPF);
2899 if (error)
2900 return (error);
2901 /*
2902 * Check to see if the user is requesting that the counters be
2903 * zeroed out. Explicitly check that the supplied data is zeroed,
2904 * as we aren't allowing the user to set the counters currently.
2905 */
2906 if (req->newptr != NULL) {
2907 if (req->newlen != sizeof(tempstats))
2908 return (EINVAL);
2909 memset(&tempstats, 0, sizeof(tempstats));
2910 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats));
2911 if (error)
2912 return (error);
2913 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0)
2914 return (EINVAL);
2915 bpf_zero_counters();
2916 return (0);
2917 }
2918 if (req->oldptr == NULL)
2919 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd)));
2920 if (bpf_bpfd_cnt == 0)
2921 return (SYSCTL_OUT(req, 0, 0));
2922 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK);
2923 BPF_LOCK();
2924 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) {
2925 BPF_UNLOCK();
2926 free(xbdbuf, M_BPF);
2927 return (ENOMEM);
2928 }
2929 index = 0;
2930 LIST_FOREACH(bp, &bpf_iflist, bif_next) {
2931 BPFIF_RLOCK(bp);
2932 /* Send writers-only first */
2933 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) {
2934 xbd = &xbdbuf[index++];
2935 BPFD_LOCK(bd);
2936 bpfstats_fill_xbpf(xbd, bd);
2937 BPFD_UNLOCK(bd);
2938 }
2939 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
2940 xbd = &xbdbuf[index++];
2941 BPFD_LOCK(bd);
2942 bpfstats_fill_xbpf(xbd, bd);
2943 BPFD_UNLOCK(bd);
2944 }
2945 BPFIF_RUNLOCK(bp);
2946 }
2947 BPF_UNLOCK();
2948 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd));
2949 free(xbdbuf, M_BPF);
2950 return (error);
2951 }
2952
2953 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL);
2954
2955 #else /* !DEV_BPF && !NETGRAPH_BPF */
2956 /*
2957 * NOP stubs to allow bpf-using drivers to load and function.
2958 *
2959 * A 'better' implementation would allow the core bpf functionality
2960 * to be loaded at runtime.
2961 */
2962 static struct bpf_if bp_null;
2963
2964 void
2965 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
2966 {
2967 }
2968
2969 void
2970 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
2971 {
2972 }
2973
2974 void
2975 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m)
2976 {
2977 }
2978
2979 void
2980 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
2981 {
2982
2983 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
2984 }
2985
2986 void
2987 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
2988 {
2989
2990 *driverp = &bp_null;
2991 }
2992
2993 void
2994 bpfdetach(struct ifnet *ifp)
2995 {
2996 }
2997
2998 u_int
2999 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
3000 {
3001 return -1; /* "no filter" behaviour */
3002 }
3003
3004 int
3005 bpf_validate(const struct bpf_insn *f, int len)
3006 {
3007 return 0; /* false */
3008 }
3009
3010 #endif /* !DEV_BPF && !NETGRAPH_BPF */
3011
3012 #ifdef DDB
3013 static void
3014 bpf_show_bpf_if(struct bpf_if *bpf_if)
3015 {
3016
3017 if (bpf_if == NULL)
3018 return;
3019 db_printf("%p:\n", bpf_if);
3020 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e);
3021 /* bif_ext.bif_next */
3022 /* bif_ext.bif_dlist */
3023 BPF_DB_PRINTF("%#x", bif_dlt);
3024 BPF_DB_PRINTF("%u", bif_hdrlen);
3025 BPF_DB_PRINTF("%p", bif_ifp);
3026 /* bif_lock */
3027 /* bif_wlist */
3028 BPF_DB_PRINTF("%#x", bif_flags);
3029 }
3030
3031 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if)
3032 {
3033
3034 if (!have_addr) {
3035 db_printf("usage: show bpf_if <struct bpf_if *>\n");
3036 return;
3037 }
3038
3039 bpf_show_bpf_if((struct bpf_if *)addr);
3040 }
3041 #endif
FreeBSD src