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 * 3. 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 8.2 (Berkeley) 3/28/94
35 *
36 * $FreeBSD: src/sys/net/bpf.c,v 1.59.2.12 2002/04/14 21:41:48 luigi Exp $
37 */
38
39 #include "use_bpf.h"
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/uio.h>
44 #include <sys/conf.h>
45 #include <sys/device.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/time.h>
49 #include <sys/proc.h>
50 #include <sys/signalvar.h>
51 #include <sys/filio.h>
52 #include <sys/sockio.h>
53 #include <sys/ttycom.h>
54 #include <sys/filedesc.h>
55
56 #include <sys/event.h>
57
58 #include <sys/socket.h>
59 #include <sys/vnode.h>
60
61 #include <net/if.h>
62 #include <net/bpf.h>
63 #include <net/bpfdesc.h>
64 #include <net/netmsg2.h>
65 #include <net/netisr2.h>
66
67 #include <netinet/in.h>
68 #include <netinet/if_ether.h>
69 #include <sys/kernel.h>
70 #include <sys/sysctl.h>
71
72 #include <netproto/802_11/ieee80211_dragonfly.h>
73
74 #include <sys/devfs.h>
75
76 MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
77 DEVFS_DEFINE_CLONE_BITMAP(bpf);
78
79 #if NBPF <= 1
80 #define BPF_PREALLOCATED_UNITS 4
81 #else
82 #define BPF_PREALLOCATED_UNITS NBPF
83 #endif
84
85 #if NBPF > 0
86
87 struct netmsg_bpf_output {
88 struct netmsg_base base;
89 struct mbuf *nm_mbuf;
90 struct ifnet *nm_ifp;
91 struct sockaddr *nm_dst;
92 boolean_t nm_feedback;
93 };
94
95 /*
96 * The default read buffer size is patchable.
97 */
98 static int bpf_bufsize = BPF_DEFAULTBUFSIZE;
99 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
100 &bpf_bufsize, 0, "Current size of bpf buffer");
101 int bpf_maxbufsize = BPF_MAXBUFSIZE;
102 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
103 &bpf_maxbufsize, 0, "Maximum size of bpf buffer");
104
105 /*
106 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
107 */
108 static struct bpf_if *bpf_iflist;
109
110 static struct lwkt_token bpf_token = LWKT_TOKEN_INITIALIZER(bpf_token);
111
112 static int bpf_allocbufs(struct bpf_d *);
113 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
114 static void bpf_detachd(struct bpf_d *d);
115 static void bpf_resetd(struct bpf_d *);
116 static void bpf_freed(struct bpf_d *);
117 static void bpf_mcopy(volatile const void *, volatile void *, size_t);
118 static int bpf_movein(struct uio *, int, struct mbuf **,
119 struct sockaddr *, int *, struct bpf_insn *);
120 static int bpf_setif(struct bpf_d *, struct ifreq *);
121 static void bpf_timed_out(void *);
122 static void bpf_wakeup(struct bpf_d *);
123 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
124 void (*)(volatile const void *,
125 volatile void *, size_t),
126 const struct timeval *);
127 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
128 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
129 static int bpf_setdlt(struct bpf_d *, u_int);
130 static void bpf_drvinit(void *unused);
131 static void bpf_filter_detach(struct knote *kn);
132 static int bpf_filter_read(struct knote *kn, long hint);
133
134 static d_open_t bpfopen;
135 static d_clone_t bpfclone;
136 static d_close_t bpfclose;
137 static d_read_t bpfread;
138 static d_write_t bpfwrite;
139 static d_ioctl_t bpfioctl;
140 static d_kqfilter_t bpfkqfilter;
141
142 #define CDEV_MAJOR 23
143 static struct dev_ops bpf_ops = {
144 { "bpf", 0, D_MPSAFE },
145 .d_open = bpfopen,
146 .d_close = bpfclose,
147 .d_read = bpfread,
148 .d_write = bpfwrite,
149 .d_ioctl = bpfioctl,
150 .d_kqfilter = bpfkqfilter
151 };
152
153
154 static int
bpf_movein(struct uio * uio,int linktype,struct mbuf ** mp,struct sockaddr * sockp,int * datlen,struct bpf_insn * wfilter)155 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp,
156 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter)
157 {
158 const struct ieee80211_bpf_params *p;
159 struct mbuf *m;
160 int error;
161 int len;
162 int hlen;
163 int slen;
164
165 *datlen = 0;
166 *mp = NULL;
167
168 /*
169 * Build a sockaddr based on the data link layer type.
170 * We do this at this level because the ethernet header
171 * is copied directly into the data field of the sockaddr.
172 * In the case of SLIP, there is no header and the packet
173 * is forwarded as is.
174 * Also, we are careful to leave room at the front of the mbuf
175 * for the link level header.
176 */
177 switch (linktype) {
178 case DLT_SLIP:
179 sockp->sa_family = AF_INET;
180 hlen = 0;
181 break;
182
183 case DLT_EN10MB:
184 sockp->sa_family = AF_UNSPEC;
185 /* XXX Would MAXLINKHDR be better? */
186 hlen = sizeof(struct ether_header);
187 break;
188
189 case DLT_RAW:
190 case DLT_NULL:
191 sockp->sa_family = AF_UNSPEC;
192 hlen = 0;
193 break;
194
195 case DLT_ATM_RFC1483:
196 /*
197 * en atm driver requires 4-byte atm pseudo header.
198 * though it isn't standard, vpi:vci needs to be
199 * specified anyway.
200 */
201 sockp->sa_family = AF_UNSPEC;
202 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
203 break;
204
205 case DLT_PPP:
206 sockp->sa_family = AF_UNSPEC;
207 hlen = 4; /* This should match PPP_HDRLEN */
208 break;
209
210 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
211 sockp->sa_family = AF_IEEE80211;
212 hlen = 0;
213 break;
214
215 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
216 sockp->sa_family = AF_IEEE80211;
217 sockp->sa_len = 12; /* XXX != 0 */
218 hlen = sizeof(struct ieee80211_bpf_params);
219 break;
220
221 default:
222 return(EIO);
223 }
224
225 len = uio->uio_resid;
226 *datlen = len - hlen;
227 if ((unsigned)len > MCLBYTES)
228 return(EIO);
229
230 m = m_getl(len, M_WAITOK, MT_DATA, M_PKTHDR, NULL);
231 m->m_pkthdr.len = m->m_len = len;
232 m->m_pkthdr.rcvif = NULL;
233 *mp = m;
234
235 if (m->m_len < hlen) {
236 error = EPERM;
237 goto bad;
238 }
239
240 error = uiomove(mtod(m, u_char *), len, uio);
241 if (error)
242 goto bad;
243
244 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
245 if (slen == 0) {
246 error = EPERM;
247 goto bad;
248 }
249
250 /*
251 * Make room for link header, and copy it to sockaddr.
252 */
253 if (hlen != 0) {
254 if (sockp->sa_family == AF_IEEE80211) {
255 /*
256 * Collect true length from the parameter header
257 * NB: sockp is known to be zero'd so if we do a
258 * short copy unspecified parameters will be
259 * zero.
260 * NB: packet may not be aligned after stripping
261 * bpf params
262 * XXX check ibp_vers
263 */
264 p = mtod(m, const struct ieee80211_bpf_params *);
265 hlen = p->ibp_len;
266 if (hlen > sizeof(sockp->sa_data)) {
267 error = EINVAL;
268 goto bad;
269 }
270 }
271 bcopy(m->m_data, sockp->sa_data, hlen);
272 m->m_pkthdr.len -= hlen;
273 m->m_len -= hlen;
274 m->m_data += hlen; /* XXX */
275 }
276 return (0);
277 bad:
278 m_freem(m);
279 return(error);
280 }
281
282 /*
283 * Attach file to the bpf interface, i.e. make d listen on bp.
284 * Must be called at splimp.
285 */
286 static void
bpf_attachd(struct bpf_d * d,struct bpf_if * bp)287 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
288 {
289 /*
290 * Point d at bp, and add d to the interface's list of listeners.
291 * Finally, point the driver's bpf cookie at the interface so
292 * it will divert packets to bpf.
293 */
294 lwkt_gettoken(&bpf_token);
295 d->bd_bif = bp;
296 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
297 *bp->bif_driverp = bp;
298
299 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
300 lwkt_reltoken(&bpf_token);
301 }
302
303 /*
304 * Detach a file from its interface.
305 */
306 static void
bpf_detachd(struct bpf_d * d)307 bpf_detachd(struct bpf_d *d)
308 {
309 int error;
310 struct bpf_if *bp;
311 struct ifnet *ifp;
312
313 lwkt_gettoken(&bpf_token);
314 bp = d->bd_bif;
315 ifp = bp->bif_ifp;
316
317 /* Remove d from the interface's descriptor list. */
318 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next);
319
320 if (SLIST_EMPTY(&bp->bif_dlist)) {
321 /*
322 * Let the driver know that there are no more listeners.
323 */
324 *bp->bif_driverp = NULL;
325 }
326 d->bd_bif = NULL;
327
328 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
329
330 /*
331 * Check if this descriptor had requested promiscuous mode.
332 * If so, turn it off.
333 */
334 if (d->bd_promisc) {
335 d->bd_promisc = 0;
336 error = ifpromisc(ifp, 0);
337 if (error != 0 && error != ENXIO) {
338 /*
339 * ENXIO can happen if a pccard is unplugged,
340 * Something is really wrong if we were able to put
341 * the driver into promiscuous mode, but can't
342 * take it out.
343 */
344 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n",
345 error);
346 }
347 }
348 lwkt_reltoken(&bpf_token);
349 }
350
351 /*
352 * Open ethernet device. Returns ENXIO for illegal minor device number,
353 * EBUSY if file is open by another process.
354 */
355 /* ARGSUSED */
356 static int
bpfopen(struct dev_open_args * ap)357 bpfopen(struct dev_open_args *ap)
358 {
359 cdev_t dev = ap->a_head.a_dev;
360 struct bpf_d *d;
361
362 lwkt_gettoken(&bpf_token);
363 if (ap->a_cred->cr_prison) {
364 lwkt_reltoken(&bpf_token);
365 return(EPERM);
366 }
367
368 d = dev->si_drv1;
369 /*
370 * Each minor can be opened by only one process. If the requested
371 * minor is in use, return EBUSY.
372 */
373 if (d != NULL) {
374 lwkt_reltoken(&bpf_token);
375 return(EBUSY);
376 }
377
378 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO);
379 dev->si_drv1 = d;
380 d->bd_bufsize = bpf_bufsize;
381 d->bd_sig = SIGIO;
382 d->bd_seesent = 1;
383 d->bd_feedback = 0;
384 callout_init(&d->bd_callout);
385 lwkt_reltoken(&bpf_token);
386
387 return(0);
388 }
389
390 static int
bpfclone(struct dev_clone_args * ap)391 bpfclone(struct dev_clone_args *ap)
392 {
393 int unit;
394
395 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0);
396 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit);
397
398 return 0;
399 }
400
401 /*
402 * Close the descriptor by detaching it from its interface,
403 * deallocating its buffers, and marking it free.
404 */
405 /* ARGSUSED */
406 static int
bpfclose(struct dev_close_args * ap)407 bpfclose(struct dev_close_args *ap)
408 {
409 cdev_t dev = ap->a_head.a_dev;
410 struct bpf_d *d = dev->si_drv1;
411 int unit;
412
413 lwkt_gettoken(&bpf_token);
414 funsetown(&d->bd_sigio);
415 if (d->bd_state == BPF_WAITING)
416 callout_stop(&d->bd_callout);
417 d->bd_state = BPF_IDLE;
418 if (d->bd_bif != NULL)
419 bpf_detachd(d);
420 bpf_freed(d);
421 dev->si_drv1 = NULL;
422
423 unit = dev->si_uminor;
424 if (unit >= BPF_PREALLOCATED_UNITS) {
425 destroy_dev(dev);
426 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), unit);
427 }
428 kfree(d, M_BPF);
429 lwkt_reltoken(&bpf_token);
430
431 return(0);
432 }
433
434 /*
435 * Rotate the packet buffers in descriptor d. Move the store buffer
436 * into the hold slot, and the free buffer into the store slot.
437 * Zero the length of the new store buffer.
438 */
439 #define ROTATE_BUFFERS(d) \
440 (d)->bd_hbuf = (d)->bd_sbuf; \
441 (d)->bd_hlen = (d)->bd_slen; \
442 (d)->bd_sbuf = (d)->bd_fbuf; \
443 (d)->bd_slen = 0; \
444 (d)->bd_fbuf = NULL;
445 /*
446 * bpfread - read next chunk of packets from buffers
447 */
448 static int
bpfread(struct dev_read_args * ap)449 bpfread(struct dev_read_args *ap)
450 {
451 cdev_t dev = ap->a_head.a_dev;
452 struct bpf_d *d = dev->si_drv1;
453 int timed_out;
454 int error;
455
456 lwkt_gettoken(&bpf_token);
457 /*
458 * Restrict application to use a buffer the same size as
459 * as kernel buffers.
460 */
461 if (ap->a_uio->uio_resid != d->bd_bufsize) {
462 lwkt_reltoken(&bpf_token);
463 return(EINVAL);
464 }
465
466 if (d->bd_state == BPF_WAITING)
467 callout_stop(&d->bd_callout);
468 timed_out = (d->bd_state == BPF_TIMED_OUT);
469 d->bd_state = BPF_IDLE;
470 /*
471 * If the hold buffer is empty, then do a timed sleep, which
472 * ends when the timeout expires or when enough packets
473 * have arrived to fill the store buffer.
474 */
475 while (d->bd_hbuf == NULL) {
476 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out)
477 && d->bd_slen != 0) {
478 /*
479 * A packet(s) either arrived since the previous,
480 * We're in immediate mode, or are reading
481 * in non-blocking mode, and a packet(s)
482 * either arrived since the previous
483 * read or arrived while we were asleep.
484 * Rotate the buffers and return what's here.
485 */
486 ROTATE_BUFFERS(d);
487 break;
488 }
489
490 /*
491 * No data is available, check to see if the bpf device
492 * is still pointed at a real interface. If not, return
493 * ENXIO so that the userland process knows to rebind
494 * it before using it again.
495 */
496 if (d->bd_bif == NULL) {
497 lwkt_reltoken(&bpf_token);
498 return(ENXIO);
499 }
500
501 if (ap->a_ioflag & IO_NDELAY) {
502 lwkt_reltoken(&bpf_token);
503 return(EWOULDBLOCK);
504 }
505 error = tsleep(d, PCATCH, "bpf", d->bd_rtout);
506 if (error == EINTR || error == ERESTART) {
507 lwkt_reltoken(&bpf_token);
508 return(error);
509 }
510 if (error == EWOULDBLOCK) {
511 /*
512 * On a timeout, return what's in the buffer,
513 * which may be nothing. If there is something
514 * in the store buffer, we can rotate the buffers.
515 */
516 if (d->bd_hbuf)
517 /*
518 * We filled up the buffer in between
519 * getting the timeout and arriving
520 * here, so we don't need to rotate.
521 */
522 break;
523
524 if (d->bd_slen == 0) {
525 lwkt_reltoken(&bpf_token);
526 return(0);
527 }
528 ROTATE_BUFFERS(d);
529 break;
530 }
531 }
532 /*
533 * At this point, we know we have something in the hold slot.
534 */
535
536 /*
537 * Move data from hold buffer into user space.
538 * We know the entire buffer is transferred since
539 * we checked above that the read buffer is bpf_bufsize bytes.
540 */
541 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio);
542
543 d->bd_fbuf = d->bd_hbuf;
544 d->bd_hbuf = NULL;
545 d->bd_hlen = 0;
546 lwkt_reltoken(&bpf_token);
547
548 return(error);
549 }
550
551
552 /*
553 * If there are processes sleeping on this descriptor, wake them up.
554 */
555 static void
bpf_wakeup(struct bpf_d * d)556 bpf_wakeup(struct bpf_d *d)
557 {
558 if (d->bd_state == BPF_WAITING) {
559 callout_stop(&d->bd_callout);
560 d->bd_state = BPF_IDLE;
561 }
562 wakeup(d);
563 if (d->bd_async && d->bd_sig && d->bd_sigio)
564 pgsigio(d->bd_sigio, d->bd_sig, 0);
565
566 KNOTE(&d->bd_kq.ki_note, 0);
567 }
568
569 static void
bpf_timed_out(void * arg)570 bpf_timed_out(void *arg)
571 {
572 struct bpf_d *d = (struct bpf_d *)arg;
573
574 if (d->bd_state == BPF_WAITING) {
575 d->bd_state = BPF_TIMED_OUT;
576 if (d->bd_slen != 0)
577 bpf_wakeup(d);
578 }
579 }
580
581 static void
bpf_output_dispatch(netmsg_t msg)582 bpf_output_dispatch(netmsg_t msg)
583 {
584 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg;
585 struct ifnet *ifp = bmsg->nm_ifp;
586 struct mbuf *mc = NULL;
587 int error;
588
589 if (bmsg->nm_feedback) {
590 mc = m_dup(bmsg->nm_mbuf, M_NOWAIT);
591 if (mc != NULL)
592 mc->m_pkthdr.rcvif = ifp;
593 }
594
595 /*
596 * The driver frees the mbuf.
597 */
598 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL);
599 lwkt_replymsg(&msg->lmsg, error);
600
601 if (mc != NULL) {
602 if (error == 0) {
603 mc->m_flags &= ~M_HASH;
604 (*ifp->if_input)(ifp, mc, NULL, -1);
605 } else {
606 m_freem(mc);
607 }
608 }
609 }
610
611 static int
bpfwrite(struct dev_write_args * ap)612 bpfwrite(struct dev_write_args *ap)
613 {
614 cdev_t dev = ap->a_head.a_dev;
615 struct bpf_d *d = dev->si_drv1;
616 struct ifnet *ifp;
617 struct mbuf *m;
618 int error, ret;
619 struct sockaddr dst;
620 int datlen;
621 struct netmsg_bpf_output bmsg;
622
623 lwkt_gettoken(&bpf_token);
624 if (d->bd_bif == NULL) {
625 lwkt_reltoken(&bpf_token);
626 return(ENXIO);
627 }
628
629 ifp = d->bd_bif->bif_ifp;
630
631 if (ap->a_uio->uio_resid == 0) {
632 lwkt_reltoken(&bpf_token);
633 return(0);
634 }
635
636 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m,
637 &dst, &datlen, d->bd_wfilter);
638 if (error) {
639 lwkt_reltoken(&bpf_token);
640 return(error);
641 }
642
643 if (datlen > ifp->if_mtu) {
644 m_freem(m);
645 lwkt_reltoken(&bpf_token);
646 return(EMSGSIZE);
647 }
648
649 if (d->bd_hdrcmplt)
650 dst.sa_family = pseudo_AF_HDRCMPLT;
651
652 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport,
653 0, bpf_output_dispatch);
654 bmsg.nm_mbuf = m;
655 bmsg.nm_ifp = ifp;
656 bmsg.nm_dst = &dst;
657
658 if (d->bd_feedback)
659 bmsg.nm_feedback = TRUE;
660 else
661 bmsg.nm_feedback = FALSE;
662
663 ret = lwkt_domsg(netisr_cpuport(0), &bmsg.base.lmsg, 0);
664
665 lwkt_reltoken(&bpf_token);
666
667 return ret;
668 }
669
670 /*
671 * Reset a descriptor by flushing its packet buffer and clearing the
672 * receive and drop counts. Should be called at splimp.
673 */
674 static void
bpf_resetd(struct bpf_d * d)675 bpf_resetd(struct bpf_d *d)
676 {
677 if (d->bd_hbuf) {
678 /* Free the hold buffer. */
679 d->bd_fbuf = d->bd_hbuf;
680 d->bd_hbuf = NULL;
681 }
682 d->bd_slen = 0;
683 d->bd_hlen = 0;
684 d->bd_rcount = 0;
685 d->bd_dcount = 0;
686 }
687
688 /*
689 * FIONREAD Check for read packet available.
690 * SIOCGIFADDR Get interface address - convenient hook to driver.
691 * BIOCGBLEN Get buffer len [for read()].
692 * BIOCSETF Set ethernet read filter.
693 * BIOCSETWF Set ethernet write filter.
694 * BIOCFLUSH Flush read packet buffer.
695 * BIOCPROMISC Put interface into promiscuous mode.
696 * BIOCGDLT Get link layer type.
697 * BIOCGETIF Get interface name.
698 * BIOCSETIF Set interface.
699 * BIOCSRTIMEOUT Set read timeout.
700 * BIOCGRTIMEOUT Get read timeout.
701 * BIOCGSTATS Get packet stats.
702 * BIOCIMMEDIATE Set immediate mode.
703 * BIOCVERSION Get filter language version.
704 * BIOCGHDRCMPLT Get "header already complete" flag
705 * BIOCSHDRCMPLT Set "header already complete" flag
706 * BIOCSFEEDBACK Set packet feedback mode.
707 * BIOCGFEEDBACK Get packet feedback mode.
708 * BIOCGSEESENT Get "see packets sent" flag
709 * BIOCSSEESENT Set "see packets sent" flag
710 * BIOCLOCK Set "locked" flag
711 */
712 /* ARGSUSED */
713 static int
bpfioctl(struct dev_ioctl_args * ap)714 bpfioctl(struct dev_ioctl_args *ap)
715 {
716 cdev_t dev = ap->a_head.a_dev;
717 struct bpf_d *d = dev->si_drv1;
718 int error = 0;
719
720 lwkt_gettoken(&bpf_token);
721 if (d->bd_state == BPF_WAITING)
722 callout_stop(&d->bd_callout);
723 d->bd_state = BPF_IDLE;
724
725 if (d->bd_locked == 1) {
726 switch (ap->a_cmd) {
727 case BIOCGBLEN:
728 case BIOCFLUSH:
729 case BIOCGDLT:
730 case BIOCGDLTLIST:
731 case BIOCGETIF:
732 case BIOCGRTIMEOUT:
733 case BIOCGSTATS:
734 case BIOCVERSION:
735 case BIOCGRSIG:
736 case BIOCGHDRCMPLT:
737 case FIONREAD:
738 case BIOCLOCK:
739 case BIOCSRTIMEOUT:
740 case BIOCIMMEDIATE:
741 case TIOCGPGRP:
742 break;
743 default:
744 lwkt_reltoken(&bpf_token);
745 return (EPERM);
746 }
747 }
748 switch (ap->a_cmd) {
749 default:
750 error = EINVAL;
751 break;
752
753 /*
754 * Check for read packet available.
755 */
756 case FIONREAD:
757 {
758 int n;
759
760 n = d->bd_slen;
761 if (d->bd_hbuf)
762 n += d->bd_hlen;
763
764 *(int *)ap->a_data = n;
765 break;
766 }
767
768 case SIOCGIFADDR:
769 {
770 struct ifnet *ifp;
771
772 if (d->bd_bif == NULL) {
773 error = EINVAL;
774 } else {
775 ifp = d->bd_bif->bif_ifp;
776 ifnet_serialize_all(ifp);
777 error = ifp->if_ioctl(ifp, ap->a_cmd,
778 ap->a_data, ap->a_cred);
779 ifnet_deserialize_all(ifp);
780 }
781 break;
782 }
783
784 /*
785 * Get buffer len [for read()].
786 */
787 case BIOCGBLEN:
788 *(u_int *)ap->a_data = d->bd_bufsize;
789 break;
790
791 /*
792 * Set buffer length.
793 */
794 case BIOCSBLEN:
795 if (d->bd_bif != NULL) {
796 error = EINVAL;
797 } else {
798 u_int size = *(u_int *)ap->a_data;
799
800 if (size > bpf_maxbufsize)
801 *(u_int *)ap->a_data = size = bpf_maxbufsize;
802 else if (size < BPF_MINBUFSIZE)
803 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE;
804 d->bd_bufsize = size;
805 }
806 break;
807
808 /*
809 * Set link layer read filter.
810 */
811 case BIOCSETF:
812 case BIOCSETWF:
813 error = bpf_setf(d, (struct bpf_program *)ap->a_data,
814 ap->a_cmd);
815 break;
816
817 /*
818 * Flush read packet buffer.
819 */
820 case BIOCFLUSH:
821 bpf_resetd(d);
822 break;
823
824 /*
825 * Put interface into promiscuous mode.
826 */
827 case BIOCPROMISC:
828 if (d->bd_bif == NULL) {
829 /*
830 * No interface attached yet.
831 */
832 error = EINVAL;
833 break;
834 }
835 if (d->bd_promisc == 0) {
836 error = ifpromisc(d->bd_bif->bif_ifp, 1);
837 if (error == 0)
838 d->bd_promisc = 1;
839 }
840 break;
841
842 /*
843 * Get device parameters.
844 */
845 case BIOCGDLT:
846 if (d->bd_bif == NULL)
847 error = EINVAL;
848 else
849 *(u_int *)ap->a_data = d->bd_bif->bif_dlt;
850 break;
851
852 /*
853 * Get a list of supported data link types.
854 */
855 case BIOCGDLTLIST:
856 if (d->bd_bif == NULL) {
857 error = EINVAL;
858 } else {
859 error = bpf_getdltlist(d,
860 (struct bpf_dltlist *)ap->a_data);
861 }
862 break;
863
864 /*
865 * Set data link type.
866 */
867 case BIOCSDLT:
868 if (d->bd_bif == NULL)
869 error = EINVAL;
870 else
871 error = bpf_setdlt(d, *(u_int *)ap->a_data);
872 break;
873
874 /*
875 * Get interface name.
876 */
877 case BIOCGETIF:
878 if (d->bd_bif == NULL) {
879 error = EINVAL;
880 } else {
881 struct ifnet *const ifp = d->bd_bif->bif_ifp;
882 struct ifreq *const ifr = (struct ifreq *)ap->a_data;
883
884 strlcpy(ifr->ifr_name, ifp->if_xname,
885 sizeof ifr->ifr_name);
886 }
887 break;
888
889 /*
890 * Set interface.
891 */
892 case BIOCSETIF:
893 error = bpf_setif(d, (struct ifreq *)ap->a_data);
894 break;
895
896 /*
897 * Set read timeout.
898 */
899 case BIOCSRTIMEOUT:
900 {
901 struct timeval *tv = (struct timeval *)ap->a_data;
902
903 /*
904 * Subtract 1 tick from tvtohz() since this isn't
905 * a one-shot timer.
906 */
907 if ((error = itimerfix(tv)) == 0)
908 d->bd_rtout = tvtohz_low(tv);
909 break;
910 }
911
912 /*
913 * Get read timeout.
914 */
915 case BIOCGRTIMEOUT:
916 {
917 struct timeval *tv = (struct timeval *)ap->a_data;
918
919 tv->tv_sec = d->bd_rtout / hz;
920 tv->tv_usec = (d->bd_rtout % hz) * ustick;
921 break;
922 }
923
924 /*
925 * Get packet stats.
926 */
927 case BIOCGSTATS:
928 {
929 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data;
930
931 bs->bs_recv = d->bd_rcount;
932 bs->bs_drop = d->bd_dcount;
933 break;
934 }
935
936 /*
937 * Set immediate mode.
938 */
939 case BIOCIMMEDIATE:
940 d->bd_immediate = *(u_int *)ap->a_data;
941 break;
942
943 case BIOCVERSION:
944 {
945 struct bpf_version *bv = (struct bpf_version *)ap->a_data;
946
947 bv->bv_major = BPF_MAJOR_VERSION;
948 bv->bv_minor = BPF_MINOR_VERSION;
949 break;
950 }
951
952 /*
953 * Get "header already complete" flag
954 */
955 case BIOCGHDRCMPLT:
956 *(u_int *)ap->a_data = d->bd_hdrcmplt;
957 break;
958
959 /*
960 * Set "header already complete" flag
961 */
962 case BIOCSHDRCMPLT:
963 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0;
964 break;
965
966 /*
967 * Get "see sent packets" flag
968 */
969 case BIOCGSEESENT:
970 *(u_int *)ap->a_data = d->bd_seesent;
971 break;
972
973 /*
974 * Set "see sent packets" flag
975 */
976 case BIOCSSEESENT:
977 d->bd_seesent = *(u_int *)ap->a_data;
978 break;
979
980 case FIOASYNC: /* Send signal on receive packets */
981 d->bd_async = *(int *)ap->a_data;
982 break;
983
984 /*
985 * Set "feed packets from bpf back to input" mode
986 */
987 case BIOCSFEEDBACK:
988 d->bd_feedback = *(int *)ap->a_data;
989 break;
990
991 /*
992 * Get "feed packets from bpf back to input" mode
993 */
994 case BIOCGFEEDBACK:
995 *(u_int *)ap->a_data = d->bd_feedback;
996 break;
997
998 case FIOSETOWN:
999 error = fsetown(*(int *)ap->a_data, &d->bd_sigio);
1000 break;
1001
1002 case FIOGETOWN:
1003 *(int *)ap->a_data = fgetown(&d->bd_sigio);
1004 break;
1005
1006 /* This is deprecated, FIOSETOWN should be used instead. */
1007 case TIOCSPGRP:
1008 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio);
1009 break;
1010
1011 /* This is deprecated, FIOGETOWN should be used instead. */
1012 case TIOCGPGRP:
1013 *(int *)ap->a_data = -fgetown(&d->bd_sigio);
1014 break;
1015
1016 case BIOCSRSIG: /* Set receive signal */
1017 {
1018 u_int sig;
1019
1020 sig = *(u_int *)ap->a_data;
1021
1022 if (sig >= NSIG)
1023 error = EINVAL;
1024 else
1025 d->bd_sig = sig;
1026 break;
1027 }
1028 case BIOCGRSIG:
1029 *(u_int *)ap->a_data = d->bd_sig;
1030 break;
1031 case BIOCLOCK:
1032 d->bd_locked = 1;
1033 break;
1034 }
1035 lwkt_reltoken(&bpf_token);
1036
1037 return(error);
1038 }
1039
1040 /*
1041 * Set d's packet filter program to fp. If this file already has a filter,
1042 * free it and replace it. Returns EINVAL for bogus requests.
1043 */
1044 static int
bpf_setf(struct bpf_d * d,struct bpf_program * fp,u_long cmd)1045 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
1046 {
1047 struct bpf_insn *fcode, *old;
1048 u_int wfilter, flen, size;
1049
1050 if (cmd == BIOCSETWF) {
1051 old = d->bd_wfilter;
1052 wfilter = 1;
1053 } else {
1054 wfilter = 0;
1055 old = d->bd_rfilter;
1056 }
1057 if (fp->bf_insns == NULL) {
1058 if (fp->bf_len != 0)
1059 return(EINVAL);
1060 if (wfilter)
1061 d->bd_wfilter = NULL;
1062 else
1063 d->bd_rfilter = NULL;
1064 bpf_resetd(d);
1065 if (old != NULL)
1066 kfree(old, M_BPF);
1067 return(0);
1068 }
1069 flen = fp->bf_len;
1070 if (flen > BPF_MAXINSNS)
1071 return(EINVAL);
1072
1073 size = flen * sizeof *fp->bf_insns;
1074 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK);
1075 if (copyin(fp->bf_insns, fcode, size) == 0 &&
1076 bpf_validate(fcode, (int)flen)) {
1077 if (wfilter)
1078 d->bd_wfilter = fcode;
1079 else
1080 d->bd_rfilter = fcode;
1081 bpf_resetd(d);
1082 if (old != NULL)
1083 kfree(old, M_BPF);
1084
1085 return(0);
1086 }
1087 kfree(fcode, M_BPF);
1088 return(EINVAL);
1089 }
1090
1091 /*
1092 * Detach a file from its current interface (if attached at all) and attach
1093 * to the interface indicated by the name stored in ifr.
1094 * Return an errno or 0.
1095 */
1096 static int
bpf_setif(struct bpf_d * d,struct ifreq * ifr)1097 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
1098 {
1099 struct bpf_if *bp;
1100 int error;
1101 struct ifnet *theywant;
1102
1103 ifnet_lock();
1104
1105 theywant = ifunit(ifr->ifr_name);
1106 if (theywant == NULL) {
1107 ifnet_unlock();
1108 return(ENXIO);
1109 }
1110
1111 /*
1112 * Look through attached interfaces for the named one.
1113 */
1114 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1115 struct ifnet *ifp = bp->bif_ifp;
1116
1117 if (ifp == NULL || ifp != theywant)
1118 continue;
1119 /* skip additional entry */
1120 if (bp->bif_driverp != &ifp->if_bpf)
1121 continue;
1122 /*
1123 * We found the requested interface.
1124 * Allocate the packet buffers if we need to.
1125 * If we're already attached to requested interface,
1126 * just flush the buffer.
1127 */
1128 if (d->bd_sbuf == NULL) {
1129 error = bpf_allocbufs(d);
1130 if (error != 0) {
1131 ifnet_unlock();
1132 return(error);
1133 }
1134 }
1135 if (bp != d->bd_bif) {
1136 if (d->bd_bif != NULL) {
1137 /*
1138 * Detach if attached to something else.
1139 */
1140 bpf_detachd(d);
1141 }
1142
1143 bpf_attachd(d, bp);
1144 }
1145 bpf_resetd(d);
1146
1147 ifnet_unlock();
1148 return(0);
1149 }
1150
1151 ifnet_unlock();
1152
1153 /* Not found. */
1154 return(ENXIO);
1155 }
1156
1157 static struct filterops bpf_read_filtops =
1158 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read };
1159
1160 static int
bpfkqfilter(struct dev_kqfilter_args * ap)1161 bpfkqfilter(struct dev_kqfilter_args *ap)
1162 {
1163 cdev_t dev = ap->a_head.a_dev;
1164 struct knote *kn = ap->a_kn;
1165 struct klist *klist;
1166 struct bpf_d *d;
1167
1168 lwkt_gettoken(&bpf_token);
1169 d = dev->si_drv1;
1170 if (d->bd_bif == NULL) {
1171 ap->a_result = 1;
1172 lwkt_reltoken(&bpf_token);
1173 return (0);
1174 }
1175
1176 ap->a_result = 0;
1177 switch (kn->kn_filter) {
1178 case EVFILT_READ:
1179 kn->kn_fop = &bpf_read_filtops;
1180 kn->kn_hook = (caddr_t)d;
1181 break;
1182 default:
1183 ap->a_result = EOPNOTSUPP;
1184 lwkt_reltoken(&bpf_token);
1185 return (0);
1186 }
1187
1188 klist = &d->bd_kq.ki_note;
1189 knote_insert(klist, kn);
1190 lwkt_reltoken(&bpf_token);
1191
1192 return (0);
1193 }
1194
1195 static void
bpf_filter_detach(struct knote * kn)1196 bpf_filter_detach(struct knote *kn)
1197 {
1198 struct klist *klist;
1199 struct bpf_d *d;
1200
1201 d = (struct bpf_d *)kn->kn_hook;
1202 klist = &d->bd_kq.ki_note;
1203 knote_remove(klist, kn);
1204 }
1205
1206 static int
bpf_filter_read(struct knote * kn,long hint)1207 bpf_filter_read(struct knote *kn, long hint)
1208 {
1209 struct bpf_d *d;
1210 int ready = 0;
1211
1212 d = (struct bpf_d *)kn->kn_hook;
1213 if (d->bd_hlen != 0 ||
1214 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
1215 d->bd_slen != 0)) {
1216 ready = 1;
1217 } else {
1218 /* Start the read timeout if necessary. */
1219 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
1220 callout_reset(&d->bd_callout, d->bd_rtout,
1221 bpf_timed_out, d);
1222 d->bd_state = BPF_WAITING;
1223 }
1224 }
1225
1226 return (ready);
1227 }
1228
1229
1230 /*
1231 * Process the packet pkt of length pktlen. The packet is parsed
1232 * by each listener's filter, and if accepted, stashed into the
1233 * corresponding buffer.
1234 */
1235 void
bpf_tap(struct bpf_if * bp,u_char * pkt,u_int pktlen)1236 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1237 {
1238 struct bpf_d *d;
1239 struct timeval tv;
1240 int gottime = 0;
1241 u_int slen;
1242
1243 lwkt_gettoken(&bpf_token);
1244 /* Re-check */
1245 if (bp == NULL) {
1246 lwkt_reltoken(&bpf_token);
1247 return;
1248 }
1249
1250 /*
1251 * Note that the ipl does not have to be raised at this point.
1252 * The only problem that could arise here is that if two different
1253 * interfaces shared any data. This is not the case.
1254 */
1255 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1256 ++d->bd_rcount;
1257 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
1258 if (slen != 0) {
1259 if (!gottime) {
1260 microtime(&tv);
1261 gottime = 1;
1262 }
1263 catchpacket(d, pkt, pktlen, slen, _bcopy, &tv);
1264 }
1265 }
1266 lwkt_reltoken(&bpf_token);
1267 }
1268
1269 /*
1270 * Copy data from an mbuf chain into a buffer. This code is derived
1271 * from m_copydata in sys/uipc_mbuf.c.
1272 */
1273 static void
bpf_mcopy(volatile const void * src_arg,volatile void * dst_arg,size_t len)1274 bpf_mcopy(volatile const void *src_arg, volatile void *dst_arg, size_t len)
1275 {
1276 volatile const struct mbuf *m;
1277 u_int count;
1278 volatile u_char *dst;
1279
1280 m = src_arg;
1281 dst = dst_arg;
1282 while (len > 0) {
1283 if (m == NULL)
1284 panic("bpf_mcopy");
1285 count = min(m->m_len, len);
1286 bcopy(mtod(m, void *), dst, count);
1287 m = m->m_next;
1288 dst += count;
1289 len -= count;
1290 }
1291 }
1292
1293 /*
1294 * Process the packet in the mbuf chain m. The packet is parsed by each
1295 * listener's filter, and if accepted, stashed into the corresponding
1296 * buffer.
1297 */
1298 void
bpf_mtap(struct bpf_if * bp,struct mbuf * m)1299 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1300 {
1301 struct bpf_d *d;
1302 u_int pktlen, slen;
1303 struct timeval tv;
1304 int gottime = 0;
1305
1306 lwkt_gettoken(&bpf_token);
1307 /* Re-check */
1308 if (bp == NULL) {
1309 lwkt_reltoken(&bpf_token);
1310 return;
1311 }
1312
1313 /* Don't compute pktlen, if no descriptor is attached. */
1314 if (SLIST_EMPTY(&bp->bif_dlist)) {
1315 lwkt_reltoken(&bpf_token);
1316 return;
1317 }
1318
1319 pktlen = m_lengthm(m, NULL);
1320
1321 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
1322 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
1323 continue;
1324 ++d->bd_rcount;
1325 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
1326 if (slen != 0) {
1327 if (!gottime) {
1328 microtime(&tv);
1329 gottime = 1;
1330 }
1331 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy,
1332 &tv);
1333 }
1334 }
1335 lwkt_reltoken(&bpf_token);
1336 }
1337
1338 /*
1339 * Incoming linkage from device drivers, where we have a mbuf chain
1340 * but need to prepend some arbitrary header from a linear buffer.
1341 *
1342 * Con up a minimal dummy header to pacify bpf. Allocate (only) a
1343 * struct m_hdr on the stack. This is safe as bpf only reads from the
1344 * fields in this header that we initialize, and will not try to free
1345 * it or keep a pointer to it.
1346 */
1347 void
bpf_mtap_hdr(struct bpf_if * arg,caddr_t data,u_int dlen,struct mbuf * m,u_int direction)1348 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m,
1349 u_int direction)
1350 {
1351 struct m_hdr mh;
1352
1353 mh.mh_flags = 0;
1354 mh.mh_next = m;
1355 mh.mh_len = dlen;
1356 mh.mh_data = data;
1357
1358 bpf_mtap(arg, (struct mbuf *) &mh);
1359 }
1360
1361 void
bpf_mtap_family(struct bpf_if * bp,struct mbuf * m,sa_family_t family)1362 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family)
1363 {
1364 u_int family4;
1365
1366 KKASSERT(family != AF_UNSPEC);
1367
1368 family4 = (u_int)family;
1369 bpf_ptap(bp, m, &family4, sizeof(family4));
1370 }
1371
1372 /*
1373 * Process the packet in the mbuf chain m with the header in m prepended.
1374 * The packet is parsed by each listener's filter, and if accepted,
1375 * stashed into the corresponding buffer.
1376 */
1377 void
bpf_ptap(struct bpf_if * bp,struct mbuf * m,const void * data,u_int dlen)1378 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1379 {
1380 struct mbuf mb;
1381
1382 /*
1383 * Craft on-stack mbuf suitable for passing to bpf_mtap.
1384 * Note that we cut corners here; we only setup what's
1385 * absolutely needed--this mbuf should never go anywhere else.
1386 */
1387 mb.m_next = m;
1388 mb.m_data = __DECONST(void *, data); /* LINTED */
1389 mb.m_len = dlen;
1390 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif;
1391
1392 bpf_mtap(bp, &mb);
1393 }
1394
1395 /*
1396 * Move the packet data from interface memory (pkt) into the
1397 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
1398 * otherwise 0. "copy" is the routine called to do the actual data
1399 * transfer. bcopy is passed in to copy contiguous chunks, while
1400 * bpf_mcopy is passed in to copy mbuf chains. In the latter case,
1401 * pkt is really an mbuf.
1402 */
1403 static void
catchpacket(struct bpf_d * d,u_char * pkt,u_int pktlen,u_int snaplen,void (* cpfn)(volatile const void *,volatile void *,size_t),const struct timeval * tv)1404 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
1405 void (*cpfn)(volatile const void *, volatile void *, size_t),
1406 const struct timeval *tv)
1407 {
1408 struct bpf_hdr *hp;
1409 int totlen, curlen;
1410 int hdrlen = d->bd_bif->bif_hdrlen;
1411 int wakeup = 0;
1412 /*
1413 * Figure out how many bytes to move. If the packet is
1414 * greater or equal to the snapshot length, transfer that
1415 * much. Otherwise, transfer the whole packet (unless
1416 * we hit the buffer size limit).
1417 */
1418 totlen = hdrlen + min(snaplen, pktlen);
1419 if (totlen > d->bd_bufsize)
1420 totlen = d->bd_bufsize;
1421
1422 /*
1423 * Round up the end of the previous packet to the next longword.
1424 */
1425 curlen = BPF_WORDALIGN(d->bd_slen);
1426 if (curlen + totlen > d->bd_bufsize) {
1427 /*
1428 * This packet will overflow the storage buffer.
1429 * Rotate the buffers if we can, then wakeup any
1430 * pending reads.
1431 */
1432 if (d->bd_fbuf == NULL) {
1433 /*
1434 * We haven't completed the previous read yet,
1435 * so drop the packet.
1436 */
1437 ++d->bd_dcount;
1438 return;
1439 }
1440 ROTATE_BUFFERS(d);
1441 wakeup = 1;
1442 curlen = 0;
1443 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
1444 /*
1445 * Immediate mode is set, or the read timeout has
1446 * already expired during a select call. A packet
1447 * arrived, so the reader should be woken up.
1448 */
1449 wakeup = 1;
1450 }
1451
1452 /*
1453 * Append the bpf header.
1454 */
1455 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
1456 hp->bh_tstamp = *tv;
1457 hp->bh_datalen = pktlen;
1458 hp->bh_hdrlen = hdrlen;
1459 /*
1460 * Copy the packet data into the store buffer and update its length.
1461 */
1462 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1463 d->bd_slen = curlen + totlen;
1464
1465 if (wakeup)
1466 bpf_wakeup(d);
1467 }
1468
1469 /*
1470 * Initialize all nonzero fields of a descriptor.
1471 */
1472 static int
bpf_allocbufs(struct bpf_d * d)1473 bpf_allocbufs(struct bpf_d *d)
1474 {
1475 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1476 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK);
1477 d->bd_slen = 0;
1478 d->bd_hlen = 0;
1479 return(0);
1480 }
1481
1482 /*
1483 * Free buffers and packet filter program currently in use by a descriptor.
1484 * Called on close.
1485 */
1486 static void
bpf_freed(struct bpf_d * d)1487 bpf_freed(struct bpf_d *d)
1488 {
1489 /*
1490 * We don't need to lock out interrupts since this descriptor has
1491 * been detached from its interface and it yet hasn't been marked
1492 * free.
1493 */
1494 if (d->bd_sbuf != NULL) {
1495 kfree(d->bd_sbuf, M_BPF);
1496 if (d->bd_hbuf != NULL)
1497 kfree(d->bd_hbuf, M_BPF);
1498 if (d->bd_fbuf != NULL)
1499 kfree(d->bd_fbuf, M_BPF);
1500 }
1501 if (d->bd_rfilter)
1502 kfree(d->bd_rfilter, M_BPF);
1503 if (d->bd_wfilter)
1504 kfree(d->bd_wfilter, M_BPF);
1505 }
1506
1507 /*
1508 * Attach an interface to bpf. ifp is a pointer to the structure
1509 * defining the interface to be attached, dlt is the link layer type,
1510 * and hdrlen is the fixed size of the link header (variable length
1511 * headers are not yet supported).
1512 */
1513 void
bpfattach(struct ifnet * ifp,u_int dlt,u_int hdrlen)1514 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1515 {
1516 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf);
1517 }
1518
1519 void
bpfattach_dlt(struct ifnet * ifp,u_int dlt,u_int hdrlen,struct bpf_if ** driverp)1520 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1521 {
1522 struct bpf_if *bp;
1523
1524 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO);
1525
1526 lwkt_gettoken(&bpf_token);
1527
1528 SLIST_INIT(&bp->bif_dlist);
1529 bp->bif_ifp = ifp;
1530 bp->bif_dlt = dlt;
1531 bp->bif_driverp = driverp;
1532 *bp->bif_driverp = NULL;
1533
1534 bp->bif_next = bpf_iflist;
1535 bpf_iflist = bp;
1536
1537 /*
1538 * Compute the length of the bpf header. This is not necessarily
1539 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1540 * that the network layer header begins on a longword boundary (for
1541 * performance reasons and to alleviate alignment restrictions).
1542 */
1543 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1544
1545 lwkt_reltoken(&bpf_token);
1546
1547 if (bootverbose)
1548 if_printf(ifp, "bpf attached\n");
1549 }
1550
1551 /*
1552 * Detach bpf from an interface. This involves detaching each descriptor
1553 * associated with the interface, and leaving bd_bif NULL. Notify each
1554 * descriptor as it's detached so that any sleepers wake up and get
1555 * ENXIO.
1556 */
1557 void
bpfdetach(struct ifnet * ifp)1558 bpfdetach(struct ifnet *ifp)
1559 {
1560 struct bpf_if *bp, *bp_prev;
1561 struct bpf_d *d;
1562
1563 lwkt_gettoken(&bpf_token);
1564
1565 /* Locate BPF interface information */
1566 bp_prev = NULL;
1567 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1568 if (ifp == bp->bif_ifp)
1569 break;
1570 bp_prev = bp;
1571 }
1572
1573 /* Interface wasn't attached */
1574 if (bp->bif_ifp == NULL) {
1575 lwkt_reltoken(&bpf_token);
1576 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname);
1577 return;
1578 }
1579
1580 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) {
1581 bpf_detachd(d);
1582 bpf_wakeup(d);
1583 }
1584
1585 if (bp_prev != NULL)
1586 bp_prev->bif_next = bp->bif_next;
1587 else
1588 bpf_iflist = bp->bif_next;
1589
1590 kfree(bp, M_BPF);
1591
1592 lwkt_reltoken(&bpf_token);
1593 }
1594
1595 /*
1596 * Get a list of available data link type of the interface.
1597 */
1598 static int
bpf_getdltlist(struct bpf_d * d,struct bpf_dltlist * bfl)1599 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
1600 {
1601 int n, error;
1602 struct ifnet *ifp;
1603 struct bpf_if *bp;
1604
1605 ifp = d->bd_bif->bif_ifp;
1606 n = 0;
1607 error = 0;
1608 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1609 if (bp->bif_ifp != ifp)
1610 continue;
1611 if (bfl->bfl_list != NULL) {
1612 if (n >= bfl->bfl_len) {
1613 return (ENOMEM);
1614 }
1615 error = copyout(&bp->bif_dlt,
1616 bfl->bfl_list + n, sizeof(u_int));
1617 }
1618 n++;
1619 }
1620 bfl->bfl_len = n;
1621 return(error);
1622 }
1623
1624 /*
1625 * Set the data link type of a BPF instance.
1626 */
1627 static int
bpf_setdlt(struct bpf_d * d,u_int dlt)1628 bpf_setdlt(struct bpf_d *d, u_int dlt)
1629 {
1630 int error, opromisc;
1631 struct ifnet *ifp;
1632 struct bpf_if *bp;
1633
1634 if (d->bd_bif->bif_dlt == dlt)
1635 return (0);
1636 ifp = d->bd_bif->bif_ifp;
1637 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
1638 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
1639 break;
1640 }
1641 if (bp != NULL) {
1642 opromisc = d->bd_promisc;
1643 bpf_detachd(d);
1644 bpf_attachd(d, bp);
1645 bpf_resetd(d);
1646 if (opromisc) {
1647 error = ifpromisc(bp->bif_ifp, 1);
1648 if (error) {
1649 if_printf(bp->bif_ifp,
1650 "bpf_setdlt: ifpromisc failed (%d)\n",
1651 error);
1652 } else {
1653 d->bd_promisc = 1;
1654 }
1655 }
1656 }
1657 return(bp == NULL ? EINVAL : 0);
1658 }
1659
1660 void
bpf_gettoken(void)1661 bpf_gettoken(void)
1662 {
1663 lwkt_gettoken(&bpf_token);
1664 }
1665
1666 void
bpf_reltoken(void)1667 bpf_reltoken(void)
1668 {
1669 lwkt_reltoken(&bpf_token);
1670 }
1671
1672 static void
bpf_drvinit(void * unused)1673 bpf_drvinit(void *unused)
1674 {
1675 int i;
1676
1677 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf),
1678 bpfclone, 0, 0, 0600, "bpf");
1679 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) {
1680 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i);
1681 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i);
1682 }
1683 }
1684
1685 static void
bpf_drvuninit(void * unused)1686 bpf_drvuninit(void *unused)
1687 {
1688 devfs_clone_handler_del("bpf");
1689 dev_ops_remove_all(&bpf_ops);
1690 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf));
1691 }
1692
1693 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR, bpf_drvinit, NULL);
1694 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL);
1695
1696 #else /* !BPF */
1697 /*
1698 * NOP stubs to allow bpf-using drivers to load and function.
1699 *
1700 * A 'better' implementation would allow the core bpf functionality
1701 * to be loaded at runtime.
1702 */
1703
1704 void
bpf_tap(struct bpf_if * bp,u_char * pkt,u_int pktlen)1705 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
1706 {
1707 }
1708
1709 void
bpf_mtap(struct bpf_if * bp,struct mbuf * m)1710 bpf_mtap(struct bpf_if *bp, struct mbuf *m)
1711 {
1712 }
1713
1714 void
bpf_ptap(struct bpf_if * bp,struct mbuf * m,const void * data,u_int dlen)1715 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen)
1716 {
1717 }
1718
1719 void
bpfattach(struct ifnet * ifp,u_int dlt,u_int hdrlen)1720 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
1721 {
1722 }
1723
1724 void
bpfattach_dlt(struct ifnet * ifp,u_int dlt,u_int hdrlen,struct bpf_if ** driverp)1725 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
1726 {
1727 }
1728
1729 void
bpfdetach(struct ifnet * ifp)1730 bpfdetach(struct ifnet *ifp)
1731 {
1732 }
1733
1734 u_int
bpf_filter(const struct bpf_insn * pc,u_char * p,u_int wirelen,u_int buflen)1735 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
1736 {
1737 return -1; /* "no filter" behaviour */
1738 }
1739
1740 void
bpf_gettoken(void)1741 bpf_gettoken(void)
1742 {
1743 }
1744
1745 void
bpf_reltoken(void)1746 bpf_reltoken(void)
1747 {
1748 }
1749
1750 #endif /* !BPF */
1751