1 /*
2 * Copyright (c) 2000-2022 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /*
29 * Copyright (c) 1990, 1991, 1993
30 * The Regents of the University of California. All rights reserved.
31 *
32 * This code is derived from the Stanford/CMU enet packet filter,
33 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
34 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
35 * Berkeley Laboratory.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. All advertising materials mentioning features or use of this software
46 * must display the following acknowledgement:
47 * This product includes software developed by the University of
48 * California, Berkeley and its contributors.
49 * 4. Neither the name of the University nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
65 * @(#)bpf.c 8.2 (Berkeley) 3/28/94
66 *
67 * $FreeBSD: src/sys/net/bpf.c,v 1.59.2.5 2001/01/05 04:49:09 jdp Exp $
68 */
69 /*
70 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
71 * support for mandatory and extensible security protections. This notice
72 * is included in support of clause 2.2 (b) of the Apple Public License,
73 * Version 2.0.
74 */
75
76 #include "bpf.h"
77
78 #ifndef __GNUC__
79 #define inline
80 #else
81 #define inline __inline
82 #endif
83
84 #include <sys/param.h>
85 #include <sys/systm.h>
86 #include <sys/conf.h>
87 #include <sys/malloc.h>
88 #include <sys/mbuf.h>
89 #include <sys/time.h>
90 #include <sys/proc.h>
91 #include <sys/signalvar.h>
92 #include <sys/filio.h>
93 #include <sys/sockio.h>
94 #include <sys/ttycom.h>
95 #include <sys/filedesc.h>
96 #include <sys/uio_internal.h>
97 #include <sys/file_internal.h>
98 #include <sys/event.h>
99
100 #include <sys/poll.h>
101
102 #include <sys/socket.h>
103 #include <sys/socketvar.h>
104 #include <sys/vnode.h>
105
106 #include <net/if.h>
107 #include <net/bpf.h>
108 #include <net/bpfdesc.h>
109
110 #include <netinet/in.h>
111 #include <netinet/ip.h>
112 #include <netinet/ip6.h>
113 #include <netinet/in_pcb.h>
114 #include <netinet/in_var.h>
115 #include <netinet/ip_var.h>
116 #include <netinet/tcp.h>
117 #include <netinet/tcp_var.h>
118 #include <netinet/udp.h>
119 #include <netinet/udp_var.h>
120 #include <netinet/if_ether.h>
121 #include <netinet/isakmp.h>
122 #include <netinet6/esp.h>
123 #include <sys/kernel.h>
124 #include <sys/sysctl.h>
125 #include <net/firewire.h>
126
127 #include <miscfs/devfs/devfs.h>
128 #include <net/dlil.h>
129 #include <net/pktap.h>
130
131 #include <kern/assert.h>
132 #include <kern/locks.h>
133 #include <kern/thread_call.h>
134 #include <libkern/section_keywords.h>
135
136 #include <os/log.h>
137
138 #include <IOKit/IOBSD.h>
139
140 #include <net/sockaddr_utils.h>
141
142 extern int tvtohz(struct timeval *);
143 extern const char *proc_name_address(void *p);
144
145 #define BPF_BUFSIZE 4096
146
147 #define PRINET 26 /* interruptible */
148
149 #define ISAKMP_HDR_SIZE (sizeof(struct isakmp) + sizeof(struct isakmp_gen))
150 #define ESP_HDR_SIZE sizeof(struct newesp)
151
152 #define BPF_WRITE_LEEWAY 18 /* space for link layer header */
153
154 #define BPF_WRITE_MAX 0x1000000 /* 16 MB arbitrary value */
155
156 typedef void (*pktcopyfunc_t)(const void *, void *, size_t);
157
158 /*
159 * The default read buffer size is patchable.
160 */
161 static unsigned int bpf_bufsize = BPF_BUFSIZE;
162 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW | CTLFLAG_LOCKED,
163 &bpf_bufsize, 0, "");
164
165 __private_extern__ unsigned int bpf_maxbufsize = BPF_MAXBUFSIZE;
166 static int sysctl_bpf_maxbufsize SYSCTL_HANDLER_ARGS;
167 SYSCTL_PROC(_debug, OID_AUTO, bpf_maxbufsize, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
168 &bpf_maxbufsize, 0,
169 sysctl_bpf_maxbufsize, "I", "Default BPF max buffer size");
170
171 extern const int copysize_limit_panic;
172 #define BPF_BUFSIZE_CAP (copysize_limit_panic >> 1)
173 static int sysctl_bpf_bufsize_cap SYSCTL_HANDLER_ARGS;
174 SYSCTL_PROC(_debug, OID_AUTO, bpf_bufsize_cap, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_LOCKED,
175 0, 0,
176 sysctl_bpf_bufsize_cap, "I", "Upper limit on BPF max buffer size");
177
178 #define BPF_MAX_DEVICES 256
179 static unsigned int bpf_maxdevices = BPF_MAX_DEVICES;
180 SYSCTL_UINT(_debug, OID_AUTO, bpf_maxdevices, CTLFLAG_RD | CTLFLAG_LOCKED,
181 &bpf_maxdevices, 0, "");
182
183 /*
184 * bpf_wantpktap controls the defaul visibility of DLT_PKTAP
185 * For OS X is off by default so process need to use the ioctl BPF_WANT_PKTAP
186 * explicitly to be able to use DLT_PKTAP.
187 */
188 #if !XNU_TARGET_OS_OSX
189 static unsigned int bpf_wantpktap = 1;
190 #else /* XNU_TARGET_OS_OSX */
191 static unsigned int bpf_wantpktap = 0;
192 #endif /* XNU_TARGET_OS_OSX */
193 SYSCTL_UINT(_debug, OID_AUTO, bpf_wantpktap, CTLFLAG_RW | CTLFLAG_LOCKED,
194 &bpf_wantpktap, 0, "");
195
196 static int bpf_debug = 0;
197 SYSCTL_INT(_debug, OID_AUTO, bpf_debug, CTLFLAG_RW | CTLFLAG_LOCKED,
198 &bpf_debug, 0, "");
199
200 static unsigned long bpf_trunc_overflow = 0;
201 SYSCTL_ULONG(_debug, OID_AUTO, bpf_trunc_overflow, CTLFLAG_RD | CTLFLAG_LOCKED,
202 &bpf_trunc_overflow, "");
203
204 static int bpf_hdr_comp_enable = 1;
205 SYSCTL_INT(_debug, OID_AUTO, bpf_hdr_comp_enable, CTLFLAG_RW | CTLFLAG_LOCKED,
206 &bpf_hdr_comp_enable, 1, "");
207
208 static int sysctl_bpf_stats SYSCTL_HANDLER_ARGS;
209 SYSCTL_PROC(_debug, OID_AUTO, bpf_stats, CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
210 0, 0,
211 sysctl_bpf_stats, "S", "BPF statistics");
212
213 /*
214 * bpf_iflist is the list of interfaces; each corresponds to an ifnet
215 * bpf_dtab holds pointer to the descriptors, indexed by minor device #
216 */
217 static struct bpf_if *bpf_iflist;
218 /*
219 * BSD now stores the bpf_d in the dev_t which is a struct
220 * on their system. Our dev_t is an int, so we still store
221 * the bpf_d in a separate table indexed by minor device #.
222 *
223 * The value stored in bpf_dtab[n] represent three states:
224 * NULL: device not opened
225 * BPF_DEV_RESERVED: device opening or closing
226 * other: device <n> opened with pointer to storage
227 */
228 static struct bpf_d *BPF_DEV_RESERVED = __unsafe_forge_single(struct bpf_d *, 1);
229 static unsigned int bpf_dtab_size = 0;
230 static struct bpf_d **__counted_by(bpf_dtab_size) bpf_dtab = NULL;
231 static unsigned int nbpfilter = 0;
232 static unsigned bpf_bpfd_cnt = 0;
233
234 static LCK_GRP_DECLARE(bpf_mlock_grp, "bpf");
235 static LCK_MTX_DECLARE(bpf_mlock_data, &bpf_mlock_grp);
236 static lck_mtx_t *const bpf_mlock = &bpf_mlock_data;
237
238 static int bpf_allocbufs(struct bpf_d *);
239 static errno_t bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
240 static int bpf_detachd(struct bpf_d *d);
241 static void bpf_freed(struct bpf_d *);
242 static int bpf_setif(struct bpf_d *, ifnet_t ifp, bool, bool, bool);
243 static void bpf_timed_out(void *, void *);
244 static void bpf_wakeup(struct bpf_d *);
245 static uint32_t get_pkt_trunc_len(struct bpf_packet *);
246 static void catchpacket(struct bpf_d *, struct bpf_packet *, u_int, int);
247 static void reset_d(struct bpf_d *);
248 static int bpf_setf(struct bpf_d *, u_int, user_addr_t, u_long);
249 static int bpf_getdltlist(struct bpf_d *, caddr_t __bidi_indexable, struct proc *);
250 static int bpf_setdlt(struct bpf_d *, u_int);
251 static int bpf_set_traffic_class(struct bpf_d *, int);
252 static void bpf_set_packet_service_class(struct mbuf *, int);
253
254 static void bpf_acquire_d(struct bpf_d *);
255 static void bpf_release_d(struct bpf_d *);
256
257 static int bpf_devsw_installed;
258
259 void bpf_init(void *unused);
260 static int bpf_tap_callback(struct ifnet *ifp, struct mbuf *m);
261
262 /*
263 * Darwin differs from BSD here, the following are static
264 * on BSD and not static on Darwin.
265 */
266 d_open_t bpfopen;
267 d_close_t bpfclose;
268 d_read_t bpfread;
269 d_write_t bpfwrite;
270 ioctl_fcn_t bpfioctl;
271 select_fcn_t bpfselect;
272
273 /* Darwin's cdevsw struct differs slightly from BSDs */
274 #define CDEV_MAJOR 23
275 static const struct cdevsw bpf_cdevsw = {
276 .d_open = bpfopen,
277 .d_close = bpfclose,
278 .d_read = bpfread,
279 .d_write = bpfwrite,
280 .d_ioctl = bpfioctl,
281 .d_stop = eno_stop,
282 .d_reset = eno_reset,
283 .d_ttys = NULL,
284 .d_select = bpfselect,
285 .d_mmap = eno_mmap,
286 .d_strategy = eno_strat,
287 .d_reserved_1 = eno_getc,
288 .d_reserved_2 = eno_putc,
289 .d_type = 0
290 };
291
292 #define SOCKADDR_HDR_LEN offsetof(struct sockaddr, sa_data)
293
294 static int
bpf_copy_uio_to_mbuf_packet(struct uio * auio,int bytes_to_copy,struct mbuf * top)295 bpf_copy_uio_to_mbuf_packet(struct uio *auio, int bytes_to_copy, struct mbuf *top)
296 {
297 int error = 0;
298
299 for (struct mbuf *m = top; m != NULL; m = m->m_next) {
300 int mlen;
301
302 if (m->m_flags & M_EXT) {
303 mlen = m->m_ext.ext_size - (int)M_LEADINGSPACE(m);
304 } else if (m->m_flags & M_PKTHDR) {
305 mlen = MHLEN - (int)M_LEADINGSPACE(m);
306 } else {
307 mlen = MLEN - (int)M_LEADINGSPACE(m);
308 }
309 int copy_len = imin((int)mlen, bytes_to_copy);
310
311 error = uiomove(mtod(m, caddr_t), (int)copy_len, auio);
312 if (error != 0) {
313 os_log(OS_LOG_DEFAULT, "bpf_copy_uio_to_mbuf_packet: len %d error %d",
314 copy_len, error);
315 goto done;
316 }
317 m->m_len = copy_len;
318 top->m_pkthdr.len += copy_len;
319
320 if (bytes_to_copy > copy_len) {
321 bytes_to_copy -= copy_len;
322 } else {
323 break;
324 }
325 }
326 done:
327 return error;
328 }
329
330 static inline void
bpf_set_bcast_mcast(mbuf_t m,struct ether_header * eh)331 bpf_set_bcast_mcast(mbuf_t m, struct ether_header * eh)
332 {
333 if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
334 if (_ether_cmp(etherbroadcastaddr, eh->ether_dhost) == 0) {
335 m->m_flags |= M_BCAST;
336 } else {
337 m->m_flags |= M_MCAST;
338 }
339 }
340 }
341
342 #if DEBUG | DEVELOPMENT
343 static void
bpf_log_bcast(const char * func,const char * ifname,uint16_t flags,bool hdrcmplt)344 bpf_log_bcast(const char * func, const char * ifname, uint16_t flags,
345 bool hdrcmplt)
346 {
347 const char * type;
348
349 if ((flags & M_BCAST) != 0) {
350 type = "broadcast";
351 } else if ((flags & M_MCAST) != 0) {
352 type = "multicast";
353 } else {
354 type = "unicast";
355 }
356 os_log(OS_LOG_DEFAULT, "%s %s %s hdrcmplt=%s", func, ifname, type,
357 hdrcmplt ? "true" : "false");
358 }
359 #endif /* DEBUG | DEVELOPMENT */
360
361 static int
bpf_movein(struct uio * uio,int copy_len,struct bpf_d * d,struct mbuf ** mp,struct sockaddr * sockp)362 bpf_movein(struct uio *uio, int copy_len, struct bpf_d *d, struct mbuf **mp,
363 struct sockaddr *sockp)
364 {
365 mbuf_ref_t m = NULL;
366 int error;
367 int len;
368 uint8_t sa_family;
369 int hlen = 0;
370 struct ifnet *ifp = d->bd_bif->bif_ifp;
371 int linktype = (int)d->bd_bif->bif_dlt;
372
373 switch (linktype) {
374 #if SLIP
375 case DLT_SLIP:
376 sa_family = AF_INET;
377 hlen = 0;
378 break;
379 #endif /* SLIP */
380
381 case DLT_EN10MB:
382 sa_family = AF_UNSPEC;
383 /* XXX Would MAXLINKHDR be better? */
384 hlen = sizeof(struct ether_header);
385 break;
386
387 #if FDDI
388 case DLT_FDDI:
389 #if defined(__FreeBSD__) || defined(__bsdi__)
390 sa_family = AF_IMPLINK;
391 hlen = 0;
392 #else
393 sa_family = AF_UNSPEC;
394 /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */
395 hlen = 24;
396 #endif
397 break;
398 #endif /* FDDI */
399
400 case DLT_RAW:
401 case DLT_NULL:
402 sa_family = AF_UNSPEC;
403 hlen = 0;
404 break;
405
406 #ifdef __FreeBSD__
407 case DLT_ATM_RFC1483:
408 /*
409 * en atm driver requires 4-byte atm pseudo header.
410 * though it isn't standard, vpi:vci needs to be
411 * specified anyway.
412 */
413 sa_family = AF_UNSPEC;
414 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
415 break;
416 #endif
417
418 case DLT_PPP:
419 sa_family = AF_UNSPEC;
420 hlen = 4; /* This should match PPP_HDRLEN */
421 break;
422
423 case DLT_APPLE_IP_OVER_IEEE1394:
424 sa_family = AF_UNSPEC;
425 hlen = sizeof(struct firewire_header);
426 break;
427
428 case DLT_IEEE802_11: /* IEEE 802.11 wireless */
429 sa_family = AF_IEEE80211;
430 hlen = 0;
431 break;
432
433 case DLT_IEEE802_11_RADIO:
434 sa_family = AF_IEEE80211;
435 hlen = 0;
436 break;
437
438 default:
439 return EIO;
440 }
441
442 if (sockp) {
443 /*
444 * Build a sockaddr based on the data link layer type.
445 * We do this at this level because the ethernet header
446 * is copied directly into the data field of the sockaddr.
447 * In the case of SLIP, there is no header and the packet
448 * is forwarded as is.
449 * Also, we are careful to leave room at the front of the mbuf
450 * for the link level header.
451 */
452 if ((hlen + SOCKADDR_HDR_LEN) > sockp->sa_len) {
453 return EIO;
454 }
455 sockp->sa_family = sa_family;
456 } else {
457 /*
458 * We're directly sending the packet data supplied by
459 * the user; we don't need to make room for the link
460 * header, and don't need the header length value any
461 * more, so set it to 0.
462 */
463 hlen = 0;
464 }
465
466 len = (int)uio_resid(uio);
467 if (len < copy_len) {
468 os_log(OS_LOG_DEFAULT, "bpfwrite: len %d if %s less than copy_len %d",
469 (unsigned)len, ifp->if_xname, copy_len);
470 return EMSGSIZE;
471 }
472 len = copy_len;
473 if (len < hlen || (unsigned)len > BPF_WRITE_MAX) {
474 os_log(OS_LOG_DEFAULT, "bpfwrite: bad len %d if %s",
475 (unsigned)len, ifp->if_xname);
476 return EMSGSIZE;
477 }
478 if (d->bd_write_size_max != 0) {
479 if ((len - hlen) > (d->bd_write_size_max + BPF_WRITE_LEEWAY)) {
480 os_log(OS_LOG_DEFAULT, "bpfwrite: len %u - hlen %u too big if %s write_size_max %u",
481 (unsigned)len, (unsigned)hlen, ifp->if_xname, d->bd_write_size_max);
482 }
483 } else if ((len - hlen) > (ifp->if_mtu + BPF_WRITE_LEEWAY)) {
484 os_log(OS_LOG_DEFAULT, "bpfwrite: len %u - hlen %u too big if %s mtu %u",
485 (unsigned)len, (unsigned)hlen, ifp->if_xname, ifp->if_mtu);
486 return EMSGSIZE;
487 }
488
489 /* drop lock while allocating mbuf and copying data */
490 lck_mtx_unlock(bpf_mlock);
491
492 error = mbuf_allocpacket(MBUF_WAITOK, len, NULL, &m);
493 if (error != 0) {
494 os_log(OS_LOG_DEFAULT,
495 "bpfwrite mbuf_allocpacket len %d error %d", len, error);
496 goto bad;
497 }
498 /*
499 * Make room for link header -- the packet length is 0 at this stage
500 */
501 if (hlen != 0) {
502 m->m_data += hlen; /* leading space */
503 error = uiomove((caddr_t)sockp->sa_data, hlen, uio);
504 if (error) {
505 os_log(OS_LOG_DEFAULT,
506 "bpfwrite uiomove hlen %d error %d", hlen, error);
507 goto bad;
508 }
509 len -= hlen;
510 if (linktype == DLT_EN10MB) {
511 struct ether_header * eh;
512
513 eh = (struct ether_header *)(void *)sockp->sa_data;
514 bpf_set_bcast_mcast(m, eh);
515 #if DEBUG || DEVELOPMENT
516 if (__improbable(bpf_debug != 0)) {
517 bpf_log_bcast(__func__, ifp->if_xname,
518 m->m_flags, false);
519 }
520 #endif /* DEBUG || DEVELOPMENT */
521 }
522 }
523 /*
524 * bpf_copy_uio_to_mbuf_packet() does set the length of each mbuf and adds it to
525 * the total packet length
526 */
527 error = bpf_copy_uio_to_mbuf_packet(uio, len, m);
528 if (error != 0) {
529 os_log(OS_LOG_DEFAULT,
530 "bpfwrite bpf_copy_uio_to_mbuf_packet error %d", error);
531 goto bad;
532 }
533
534 /* Check for multicast destination */
535 if (hlen == 0 && linktype == DLT_EN10MB) {
536 struct ether_header *eh;
537
538 eh = mtod(m, struct ether_header *);
539 bpf_set_bcast_mcast(m, eh);
540 #if DEBUG || DEVELOPMENT
541 if (__improbable(bpf_debug != 0)) {
542 bpf_log_bcast(__func__, ifp->if_xname,
543 m->m_flags, true);
544 }
545 #endif /* DEBUG || DEVELOPMENT */
546 }
547 *mp = m;
548
549 lck_mtx_lock(bpf_mlock);
550 return 0;
551 bad:
552 if (m != NULL) {
553 m_freem(m);
554 }
555 lck_mtx_lock(bpf_mlock);
556 return error;
557 }
558
559 static int
bpf_movein_batch(struct uio * uio,struct bpf_d * d,struct mbuf ** mp,struct sockaddr * sockp)560 bpf_movein_batch(struct uio *uio, struct bpf_d *d, struct mbuf **mp,
561 struct sockaddr *sockp)
562 {
563 int error = 0;
564 user_ssize_t resid;
565 int count = 0;
566 struct mbuf *last = NULL;
567
568 *mp = NULL;
569 while ((resid = uio_resid(uio)) >= sizeof(struct bpf_hdr)) {
570 struct bpf_hdr bpfhdr = {};
571 int bpf_hdr_min_len = offsetof(struct bpf_hdr, bh_hdrlen) + sizeof(bpfhdr.bh_hdrlen);
572 int padding_len;
573
574 error = uiomove((caddr_t)&bpfhdr, bpf_hdr_min_len, uio);
575 if (error != 0) {
576 os_log(OS_LOG_DEFAULT, "bpf_movein_batch uiomove error %d", error);
577 break;
578 }
579 /*
580 * Buffer validation:
581 * - ignore bh_tstamp
582 * - bh_hdrlen must fit
583 * - bh_caplen and bh_datalen must be equal
584 */
585 if (bpfhdr.bh_hdrlen < bpf_hdr_min_len) {
586 error = EINVAL;
587 os_log(OS_LOG_DEFAULT, "bpf_movein_batch bh_hdrlen %u too small",
588 bpfhdr.bh_hdrlen);
589 break;
590 }
591 if (bpfhdr.bh_caplen != bpfhdr.bh_datalen) {
592 error = EINVAL;
593 os_log(OS_LOG_DEFAULT, "bpf_movein_batch bh_caplen %u != bh_datalen %u",
594 bpfhdr.bh_caplen, bpfhdr.bh_datalen);
595 break;
596 }
597 if (bpfhdr.bh_hdrlen > resid) {
598 error = EINVAL;
599 os_log(OS_LOG_DEFAULT, "bpf_movein_batch bh_hdrlen %u too large",
600 bpfhdr.bh_hdrlen);
601 break;
602 }
603
604 /*
605 * Ignore additional bytes in the header
606 */
607 padding_len = bpfhdr.bh_hdrlen - bpf_hdr_min_len;
608 if (padding_len > 0) {
609 uio_update(uio, padding_len);
610 }
611
612 /* skip empty packets */
613 if (bpfhdr.bh_caplen > 0) {
614 mbuf_ref_t m;
615
616 /*
617 * For time being assume all packets have same destination
618 */
619 error = bpf_movein(uio, bpfhdr.bh_caplen, d, &m, sockp);
620 if (error != 0) {
621 os_log(OS_LOG_DEFAULT, "bpf_movein_batch bpf_movein error %d",
622 error);
623 break;
624 }
625 count += 1;
626
627 if (last == NULL) {
628 *mp = m;
629 } else {
630 last->m_nextpkt = m;
631 }
632 last = m;
633 }
634
635 /*
636 * Each BPF packet is padded for alignment
637 */
638 padding_len = BPF_WORDALIGN(bpfhdr.bh_hdrlen + bpfhdr.bh_caplen) - (bpfhdr.bh_hdrlen + bpfhdr.bh_caplen);
639 if (padding_len > 0) {
640 uio_update(uio, padding_len);
641 }
642 }
643
644 if (error != 0) {
645 if (*mp != NULL) {
646 m_freem_list(*mp);
647 *mp = NULL;
648 }
649 }
650 return error;
651 }
652
653 /*
654 * The dynamic addition of a new device node must block all processes that
655 * are opening the last device so that no process will get an unexpected
656 * ENOENT
657 */
658 static void
bpf_make_dev_t(int maj)659 bpf_make_dev_t(int maj)
660 {
661 static int bpf_growing = 0;
662 unsigned int cur_size = nbpfilter, i;
663
664 if (nbpfilter >= BPF_MAX_DEVICES) {
665 return;
666 }
667
668 while (bpf_growing) {
669 /* Wait until new device has been created */
670 (void) tsleep((caddr_t)&bpf_growing, PZERO, "bpf_growing", 0);
671 }
672 if (nbpfilter > cur_size) {
673 /* other thread grew it already */
674 return;
675 }
676 bpf_growing = 1;
677
678 /* need to grow bpf_dtab first */
679 if (nbpfilter == bpf_dtab_size) {
680 unsigned int new_dtab_size;
681 struct bpf_d **new_dtab = NULL;
682
683 new_dtab_size = bpf_dtab_size + NBPFILTER;
684 new_dtab = krealloc_type(struct bpf_d *,
685 bpf_dtab_size, new_dtab_size, bpf_dtab, Z_WAITOK | Z_ZERO);
686
687 if (new_dtab == 0) {
688 os_log_error(OS_LOG_DEFAULT, "bpf_make_dev_t: malloc bpf_dtab failed");
689 goto done;
690 }
691 bpf_dtab = new_dtab;
692 bpf_dtab_size = new_dtab_size;
693 }
694 i = nbpfilter++;
695 (void) devfs_make_node(makedev(maj, i),
696 DEVFS_CHAR, UID_ROOT, GID_WHEEL, 0600,
697 "bpf%d", i);
698 done:
699 bpf_growing = 0;
700 wakeup((caddr_t)&bpf_growing);
701 }
702
703 /*
704 * Attach file to the bpf interface, i.e. make d listen on bp.
705 */
706 static errno_t
bpf_attachd(struct bpf_d * d,struct bpf_if * bp)707 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
708 {
709 int first = bp->bif_dlist == NULL;
710 int error = 0;
711
712 /*
713 * Point d at bp, and add d to the interface's list of listeners.
714 * Finally, point the driver's bpf cookie at the interface so
715 * it will divert packets to bpf.
716 */
717 d->bd_bif = bp;
718 d->bd_next = bp->bif_dlist;
719 bp->bif_dlist = d;
720 bpf_bpfd_cnt++;
721
722 /*
723 * Take a reference on the device even if an error is returned
724 * because we keep the device in the interface's list of listeners
725 */
726 bpf_acquire_d(d);
727
728 if (first) {
729 /* Find the default bpf entry for this ifp */
730 if (bp->bif_ifp->if_bpf == NULL) {
731 struct bpf_if *tmp, *primary = NULL;
732
733 for (tmp = bpf_iflist; tmp; tmp = tmp->bif_next) {
734 if (tmp->bif_ifp == bp->bif_ifp) {
735 primary = tmp;
736 break;
737 }
738 }
739 bp->bif_ifp->if_bpf = primary;
740 }
741 /* Only call dlil_set_bpf_tap for primary dlt */
742 if (bp->bif_ifp->if_bpf == bp) {
743 dlil_set_bpf_tap(bp->bif_ifp, BPF_TAP_INPUT_OUTPUT,
744 bpf_tap_callback);
745 }
746
747 if (bp->bif_tap != NULL) {
748 error = bp->bif_tap(bp->bif_ifp, bp->bif_dlt,
749 BPF_TAP_INPUT_OUTPUT);
750 }
751 }
752
753 /*
754 * Reset the detach flags in case we previously detached an interface
755 */
756 d->bd_flags &= ~(BPF_DETACHING | BPF_DETACHED);
757
758 if (bp->bif_dlt == DLT_PKTAP) {
759 d->bd_flags |= BPF_FINALIZE_PKTAP;
760 } else {
761 d->bd_flags &= ~BPF_FINALIZE_PKTAP;
762 }
763 return error;
764 }
765
766 /*
767 * Detach a file from its interface.
768 *
769 * Return 1 if was closed by some thread, 0 otherwise
770 */
771 static int
bpf_detachd(struct bpf_d * d)772 bpf_detachd(struct bpf_d *d)
773 {
774 struct bpf_d **p;
775 struct bpf_if *bp;
776 struct ifnet *ifp;
777 uint32_t dlt;
778 bpf_tap_func disable_tap;
779 uint8_t bd_promisc;
780
781 int bpf_closed = d->bd_flags & BPF_CLOSING;
782 /*
783 * Some other thread already detached
784 */
785 if ((d->bd_flags & (BPF_DETACHED | BPF_DETACHING)) != 0) {
786 goto done;
787 }
788 /*
789 * This thread is doing the detach
790 */
791 d->bd_flags |= BPF_DETACHING;
792
793 ifp = d->bd_bif->bif_ifp;
794 bp = d->bd_bif;
795
796 /* Remove d from the interface's descriptor list. */
797 p = &bp->bif_dlist;
798 while (*p != d) {
799 p = &(*p)->bd_next;
800 if (*p == 0) {
801 panic("bpf_detachd: descriptor not in list");
802 }
803 }
804 *p = (*p)->bd_next;
805 bpf_bpfd_cnt--;
806 disable_tap = NULL;
807 if (bp->bif_dlist == 0) {
808 /*
809 * Let the driver know that there are no more listeners.
810 */
811 /* Only call dlil_set_bpf_tap for primary dlt */
812 if (bp->bif_ifp->if_bpf == bp) {
813 dlil_set_bpf_tap(ifp, BPF_TAP_DISABLE, NULL);
814 }
815
816 disable_tap = bp->bif_tap;
817 if (disable_tap) {
818 dlt = bp->bif_dlt;
819 }
820
821 for (bp = bpf_iflist; bp; bp = bp->bif_next) {
822 if (bp->bif_ifp == ifp && bp->bif_dlist != 0) {
823 break;
824 }
825 }
826 if (bp == NULL) {
827 ifp->if_bpf = NULL;
828 }
829 }
830 d->bd_bif = NULL;
831
832 /*
833 * Stop disabling input
834 */
835 if ((d->bd_flags & BPF_DIVERT_IN) != 0) {
836 if_clear_xflags(ifp, IFXF_DISABLE_INPUT);
837 d->bd_flags &= ~BPF_DIVERT_IN;
838
839 os_log(OS_LOG_DEFAULT,
840 "bpf_detachd: bpf%d %s disable input 0",
841 d->bd_dev_minor, if_name(ifp));
842 }
843
844 /*
845 * Check if this descriptor had requested promiscuous mode.
846 * If so, turn it off.
847 */
848 bd_promisc = d->bd_promisc;
849 d->bd_promisc = 0;
850
851 lck_mtx_unlock(bpf_mlock);
852 if (bd_promisc) {
853 if (ifnet_set_promiscuous(ifp, 0)) {
854 /*
855 * Something is really wrong if we were able to put
856 * the driver into promiscuous mode, but can't
857 * take it out.
858 * Most likely the network interface is gone.
859 */
860 os_log_error(OS_LOG_DEFAULT,
861 "%s: bpf%d ifnet_set_promiscuous %s failed",
862 __func__, d->bd_dev_minor, if_name(ifp));
863 }
864 }
865
866 if (disable_tap) {
867 disable_tap(ifp, dlt, BPF_TAP_DISABLE);
868 }
869 lck_mtx_lock(bpf_mlock);
870
871 /*
872 * Wake up other thread that are waiting for this thread to finish
873 * detaching
874 */
875 d->bd_flags &= ~BPF_DETACHING;
876 d->bd_flags |= BPF_DETACHED;
877
878 /* Refresh the local variable as d could have been modified */
879 bpf_closed = d->bd_flags & BPF_CLOSING;
880
881 os_log(OS_LOG_DEFAULT, "bpf%d%s detached from %s fcount %llu dcount %llu",
882 d->bd_dev_minor, bpf_closed ? " closed and" : "", if_name(ifp),
883 d->bd_fcount, d->bd_dcount);
884
885 /*
886 * Note that We've kept the reference because we may have dropped
887 * the lock when turning off promiscuous mode
888 */
889 bpf_release_d(d);
890 done:
891 /*
892 * Let the caller know the bpf_d is closed
893 */
894 if (bpf_closed) {
895 return 1;
896 } else {
897 return 0;
898 }
899 }
900
901 /*
902 * Start asynchronous timer, if necessary.
903 * Must be called with bpf_mlock held.
904 */
905 static void
bpf_start_timer(struct bpf_d * d)906 bpf_start_timer(struct bpf_d *d)
907 {
908 uint64_t deadline;
909 struct timeval tv;
910
911 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
912 tv.tv_sec = d->bd_rtout / hz;
913 tv.tv_usec = (d->bd_rtout % hz) * tick;
914
915 clock_interval_to_deadline(
916 (uint32_t)tv.tv_sec * USEC_PER_SEC + tv.tv_usec,
917 NSEC_PER_USEC, &deadline);
918 /*
919 * The state is BPF_IDLE, so the timer hasn't
920 * been started yet, and hasn't gone off yet;
921 * there is no thread call scheduled, so this
922 * won't change the schedule.
923 *
924 * XXX - what if, by the time it gets entered,
925 * the deadline has already passed?
926 */
927 thread_call_enter_delayed(d->bd_thread_call, deadline);
928 d->bd_state = BPF_WAITING;
929 }
930 }
931
932 /*
933 * Cancel asynchronous timer.
934 * Must be called with bpf_mlock held.
935 */
936 static boolean_t
bpf_stop_timer(struct bpf_d * d)937 bpf_stop_timer(struct bpf_d *d)
938 {
939 /*
940 * If the timer has already gone off, this does nothing.
941 * Our caller is expected to set d->bd_state to BPF_IDLE,
942 * with the bpf_mlock, after we are called. bpf_timed_out()
943 * also grabs bpf_mlock, so, if the timer has gone off and
944 * bpf_timed_out() hasn't finished, it's waiting for the
945 * lock; when this thread releases the lock, it will
946 * find the state is BPF_IDLE, and just release the
947 * lock and return.
948 */
949 return thread_call_cancel(d->bd_thread_call);
950 }
951
952 void
bpf_acquire_d(struct bpf_d * d)953 bpf_acquire_d(struct bpf_d *d)
954 {
955 void *__single lr_saved = __unsafe_forge_single(void *, __builtin_return_address(0));
956
957 LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
958
959 d->bd_refcnt += 1;
960
961 d->bd_ref_lr[d->bd_next_ref_lr] = lr_saved;
962 d->bd_next_ref_lr = (d->bd_next_ref_lr + 1) % BPF_REF_HIST;
963 }
964
965 void
bpf_release_d(struct bpf_d * d)966 bpf_release_d(struct bpf_d *d)
967 {
968 void *__single lr_saved = __unsafe_forge_single(void *, __builtin_return_address(0));
969
970 LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
971
972 if (d->bd_refcnt <= 0) {
973 panic("%s: %p refcnt <= 0", __func__, d);
974 }
975
976 d->bd_refcnt -= 1;
977
978 d->bd_unref_lr[d->bd_next_unref_lr] = lr_saved;
979 d->bd_next_unref_lr = (d->bd_next_unref_lr + 1) % BPF_REF_HIST;
980
981 if (d->bd_refcnt == 0) {
982 /* Assert the device is detached */
983 if ((d->bd_flags & BPF_DETACHED) == 0) {
984 panic("%s: %p BPF_DETACHED not set", __func__, d);
985 }
986
987 kfree_type(struct bpf_d, d);
988 }
989 }
990
991 /*
992 * Open ethernet device. Returns ENXIO for illegal minor device number,
993 * EBUSY if file is open by another process.
994 */
995 /* ARGSUSED */
996 int
bpfopen(dev_t dev,int flags,__unused int fmt,struct proc * p)997 bpfopen(dev_t dev, int flags, __unused int fmt,
998 struct proc *p)
999 {
1000 struct bpf_d *d;
1001
1002 lck_mtx_lock(bpf_mlock);
1003 if ((unsigned int) minor(dev) >= nbpfilter) {
1004 lck_mtx_unlock(bpf_mlock);
1005 return ENXIO;
1006 }
1007 /*
1008 * New device nodes are created on demand when opening the last one.
1009 * The programming model is for processes to loop on the minor starting
1010 * at 0 as long as EBUSY is returned. The loop stops when either the
1011 * open succeeds or an error other that EBUSY is returned. That means
1012 * that bpf_make_dev_t() must block all processes that are opening the
1013 * last node. If not all processes are blocked, they could unexpectedly
1014 * get ENOENT and abort their opening loop.
1015 */
1016 if ((unsigned int) minor(dev) == (nbpfilter - 1)) {
1017 bpf_make_dev_t(major(dev));
1018 }
1019
1020 /*
1021 * Each minor can be opened by only one process. If the requested
1022 * minor is in use, return EBUSY.
1023 *
1024 * Important: bpfopen() and bpfclose() have to check and set the status
1025 * of a device in the same lockin context otherwise the device may be
1026 * leaked because the vnode use count will be unpextectly greater than 1
1027 * when close() is called.
1028 */
1029 if (bpf_dtab[minor(dev)] == NULL) {
1030 /* Reserve while opening */
1031 bpf_dtab[minor(dev)] = BPF_DEV_RESERVED;
1032 } else {
1033 lck_mtx_unlock(bpf_mlock);
1034 return EBUSY;
1035 }
1036 d = kalloc_type(struct bpf_d, Z_WAITOK | Z_ZERO);
1037 if (d == NULL) {
1038 /* this really is a catastrophic failure */
1039 os_log_error(OS_LOG_DEFAULT,
1040 "bpfopen: bpf%d kalloc_type bpf_d failed", minor(dev));
1041 bpf_dtab[minor(dev)] = NULL;
1042 lck_mtx_unlock(bpf_mlock);
1043 return ENOMEM;
1044 }
1045
1046 /* Mark "in use" and do most initialization. */
1047 bpf_acquire_d(d);
1048 d->bd_bufsize = bpf_bufsize;
1049 d->bd_sig = SIGIO;
1050 d->bd_direction = BPF_D_INOUT;
1051 d->bd_oflags = flags;
1052 d->bd_state = BPF_IDLE;
1053 d->bd_traffic_class = SO_TC_BE;
1054 d->bd_flags |= BPF_DETACHED;
1055 if (bpf_wantpktap) {
1056 d->bd_flags |= BPF_WANT_PKTAP;
1057 } else {
1058 d->bd_flags &= ~BPF_WANT_PKTAP;
1059 }
1060
1061 d->bd_thread_call = thread_call_allocate(bpf_timed_out, d);
1062 if (d->bd_thread_call == NULL) {
1063 os_log_error(OS_LOG_DEFAULT, "bpfopen: bpf%d malloc thread call failed",
1064 minor(dev));
1065 bpf_dtab[minor(dev)] = NULL;
1066 bpf_release_d(d);
1067 lck_mtx_unlock(bpf_mlock);
1068
1069 return ENOMEM;
1070 }
1071 d->bd_opened_by = p;
1072 uuid_generate(d->bd_uuid);
1073 d->bd_pid = proc_pid(p);
1074
1075 d->bd_dev_minor = minor(dev);
1076 bpf_dtab[minor(dev)] = d; /* Mark opened */
1077 lck_mtx_unlock(bpf_mlock);
1078
1079 if (bpf_debug) {
1080 os_log(OS_LOG_DEFAULT, "bpf%u opened by %s.%u",
1081 d->bd_dev_minor, proc_name_address(p), d->bd_pid);
1082 }
1083 return 0;
1084 }
1085
1086 /*
1087 * Close the descriptor by detaching it from its interface,
1088 * deallocating its buffers, and marking it free.
1089 */
1090 /* ARGSUSED */
1091 int
bpfclose(dev_t dev,__unused int flags,__unused int fmt,__unused struct proc * p)1092 bpfclose(dev_t dev, __unused int flags, __unused int fmt,
1093 __unused struct proc *p)
1094 {
1095 struct bpf_d *d;
1096
1097 /* Take BPF lock to ensure no other thread is using the device */
1098 lck_mtx_lock(bpf_mlock);
1099
1100 d = bpf_dtab[minor(dev)];
1101 if (d == NULL || d == BPF_DEV_RESERVED) {
1102 lck_mtx_unlock(bpf_mlock);
1103 return ENXIO;
1104 }
1105
1106 /*
1107 * Other threads may call bpd_detachd() if we drop the bpf_mlock
1108 */
1109 d->bd_flags |= BPF_CLOSING;
1110
1111 if (bpf_debug != 0) {
1112 os_log(OS_LOG_DEFAULT, "%s: bpf%d",
1113 __func__, d->bd_dev_minor);
1114 }
1115
1116 bpf_dtab[minor(dev)] = BPF_DEV_RESERVED; /* Reserve while closing */
1117
1118 /*
1119 * Deal with any in-progress timeouts.
1120 */
1121 switch (d->bd_state) {
1122 case BPF_IDLE:
1123 /*
1124 * Not waiting for a timeout, and no timeout happened.
1125 */
1126 break;
1127
1128 case BPF_WAITING:
1129 /*
1130 * Waiting for a timeout.
1131 * Cancel any timer that has yet to go off,
1132 * and mark the state as "closing".
1133 * Then drop the lock to allow any timers that
1134 * *have* gone off to run to completion, and wait
1135 * for them to finish.
1136 */
1137 if (!bpf_stop_timer(d)) {
1138 /*
1139 * There was no pending call, so the call must
1140 * have been in progress. Wait for the call to
1141 * complete; we have to drop the lock while
1142 * waiting. to let the in-progrss call complete
1143 */
1144 d->bd_state = BPF_DRAINING;
1145 while (d->bd_state == BPF_DRAINING) {
1146 msleep((caddr_t)d, bpf_mlock, PRINET,
1147 "bpfdraining", NULL);
1148 }
1149 }
1150 d->bd_state = BPF_IDLE;
1151 break;
1152
1153 case BPF_TIMED_OUT:
1154 /*
1155 * Timer went off, and the timeout routine finished.
1156 */
1157 d->bd_state = BPF_IDLE;
1158 break;
1159
1160 case BPF_DRAINING:
1161 /*
1162 * Another thread is blocked on a close waiting for
1163 * a timeout to finish.
1164 * This "shouldn't happen", as the first thread to enter
1165 * bpfclose() will set bpf_dtab[minor(dev)] to 1, and
1166 * all subsequent threads should see that and fail with
1167 * ENXIO.
1168 */
1169 panic("Two threads blocked in a BPF close");
1170 break;
1171 }
1172
1173 if (d->bd_bif) {
1174 bpf_detachd(d);
1175 }
1176 selthreadclear(&d->bd_sel);
1177 thread_call_free(d->bd_thread_call);
1178
1179 while (d->bd_hbuf_read || d->bd_hbuf_write) {
1180 msleep((caddr_t)d, bpf_mlock, PRINET, "bpfclose", NULL);
1181 }
1182
1183 if (bpf_debug) {
1184 os_log(OS_LOG_DEFAULT,
1185 "bpf%u closed by %s.%u dcount %llu fcount %llu ccount %llu",
1186 d->bd_dev_minor, proc_name_address(p), d->bd_pid,
1187 d->bd_dcount, d->bd_fcount, d->bd_bcs.bcs_count_compressed_prefix);
1188 }
1189
1190 bpf_freed(d);
1191
1192 /* Mark free in same context as bpfopen comes to check */
1193 bpf_dtab[minor(dev)] = NULL; /* Mark closed */
1194
1195 bpf_release_d(d);
1196
1197 lck_mtx_unlock(bpf_mlock);
1198
1199 return 0;
1200 }
1201
1202 #define BPF_SLEEP bpf_sleep
1203
1204 static int
bpf_sleep(struct bpf_d * d,int pri,const char * wmesg,int timo)1205 bpf_sleep(struct bpf_d *d, int pri, const char *wmesg, int timo)
1206 {
1207 u_int64_t abstime = 0;
1208
1209 if (timo != 0) {
1210 clock_interval_to_deadline(timo, NSEC_PER_SEC / hz, &abstime);
1211 }
1212
1213 return msleep1((caddr_t)d, bpf_mlock, pri, wmesg, abstime);
1214 }
1215
1216 static void
bpf_finalize_pktap(struct bpf_hdr * hp,struct pktap_header * pktaphdr)1217 bpf_finalize_pktap(struct bpf_hdr *hp, struct pktap_header *pktaphdr)
1218 {
1219 if (pktaphdr->pth_flags & PTH_FLAG_V2_HDR) {
1220 struct pktap_v2_hdr *pktap_v2_hdr;
1221
1222 pktap_v2_hdr = (struct pktap_v2_hdr *)pktaphdr;
1223
1224 if (pktap_v2_hdr->pth_flags & PTH_FLAG_DELAY_PKTAP) {
1225 pktap_v2_finalize_proc_info(pktap_v2_hdr);
1226 }
1227 } else {
1228 if (pktaphdr->pth_flags & PTH_FLAG_DELAY_PKTAP) {
1229 pktap_finalize_proc_info(pktaphdr);
1230 }
1231
1232 if (pktaphdr->pth_flags & PTH_FLAG_TSTAMP) {
1233 hp->bh_tstamp.tv_sec = pktaphdr->pth_tstamp.tv_sec;
1234 hp->bh_tstamp.tv_usec = pktaphdr->pth_tstamp.tv_usec;
1235 }
1236 }
1237 }
1238
1239 /*
1240 * Rotate the packet buffers in descriptor d. Move the store buffer
1241 * into the hold slot, and the free buffer into the store slot.
1242 * Zero the length of the new store buffer.
1243 *
1244 * Note: in head drop mode, the hold buffer can be dropped so the fist packet of the
1245 * store buffer cannot be compressed as it otherwise would refer to deleted data
1246 * in a dropped hold buffer that the reader process does know about
1247 */
1248 #define ROTATE_BUFFERS(d) do { \
1249 if (d->bd_hbuf_read) \
1250 panic("rotating bpf buffers during read"); \
1251 (d)->bd_hbuf = (d)->bd_sbuf; \
1252 (d)->bd_hlen = (d)->bd_slen; \
1253 (d)->bd_hcnt = (d)->bd_scnt; \
1254 (d)->bd_sbuf = (d)->bd_fbuf; \
1255 (d)->bd_slen = 0; \
1256 (d)->bd_scnt = 0; \
1257 (d)->bd_fbuf = NULL; \
1258 if ((d)->bd_headdrop != 0) \
1259 (d)->bd_prev_slen = 0; \
1260 } while(false)
1261
1262 /*
1263 * bpfread - read next chunk of packets from buffers
1264 */
1265 int
bpfread(dev_t dev,struct uio * uio,int ioflag)1266 bpfread(dev_t dev, struct uio *uio, int ioflag)
1267 {
1268 struct bpf_d *d;
1269 caddr_t hbuf;
1270 int timed_out, hbuf_len;
1271 int error;
1272 int flags;
1273
1274 lck_mtx_lock(bpf_mlock);
1275
1276 d = bpf_dtab[minor(dev)];
1277 if (d == NULL || d == BPF_DEV_RESERVED ||
1278 (d->bd_flags & BPF_CLOSING) != 0) {
1279 lck_mtx_unlock(bpf_mlock);
1280 return ENXIO;
1281 }
1282
1283 bpf_acquire_d(d);
1284
1285 /*
1286 * Restrict application to use a buffer the same size as
1287 * as kernel buffers.
1288 */
1289 if (uio_resid(uio) != d->bd_bufsize) {
1290 bpf_release_d(d);
1291 lck_mtx_unlock(bpf_mlock);
1292 return EINVAL;
1293 }
1294
1295 if (d->bd_state == BPF_WAITING) {
1296 bpf_stop_timer(d);
1297 }
1298
1299 timed_out = (d->bd_state == BPF_TIMED_OUT);
1300 d->bd_state = BPF_IDLE;
1301
1302 while (d->bd_hbuf_read) {
1303 msleep((caddr_t)d, bpf_mlock, PRINET, "bpfread", NULL);
1304 }
1305
1306 if ((d->bd_flags & BPF_CLOSING) != 0) {
1307 bpf_release_d(d);
1308 lck_mtx_unlock(bpf_mlock);
1309 return ENXIO;
1310 }
1311 /*
1312 * If the hold buffer is empty, then do a timed sleep, which
1313 * ends when the timeout expires or when enough packets
1314 * have arrived to fill the store buffer.
1315 */
1316 while (d->bd_hbuf == 0) {
1317 if ((d->bd_immediate || timed_out || (ioflag & IO_NDELAY)) &&
1318 d->bd_slen != 0) {
1319 /*
1320 * We're in immediate mode, or are reading
1321 * in non-blocking mode, or a timer was
1322 * started before the read (e.g., by select()
1323 * or poll()) and has expired and a packet(s)
1324 * either arrived since the previous
1325 * read or arrived while we were asleep.
1326 * Rotate the buffers and return what's here.
1327 */
1328 ROTATE_BUFFERS(d);
1329 break;
1330 }
1331
1332 /*
1333 * No data is available, check to see if the bpf device
1334 * is still pointed at a real interface. If not, return
1335 * ENXIO so that the userland process knows to rebind
1336 * it before using it again.
1337 */
1338 if (d->bd_bif == NULL) {
1339 bpf_release_d(d);
1340 lck_mtx_unlock(bpf_mlock);
1341 return ENXIO;
1342 }
1343 if (ioflag & IO_NDELAY) {
1344 bpf_release_d(d);
1345 lck_mtx_unlock(bpf_mlock);
1346 return EWOULDBLOCK;
1347 }
1348 error = BPF_SLEEP(d, PRINET | PCATCH, "bpf", d->bd_rtout);
1349 /*
1350 * Make sure device is still opened
1351 */
1352 if ((d->bd_flags & BPF_CLOSING) != 0) {
1353 bpf_release_d(d);
1354 lck_mtx_unlock(bpf_mlock);
1355 return ENXIO;
1356 }
1357
1358 while (d->bd_hbuf_read) {
1359 msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_read",
1360 NULL);
1361 }
1362
1363 if ((d->bd_flags & BPF_CLOSING) != 0) {
1364 bpf_release_d(d);
1365 lck_mtx_unlock(bpf_mlock);
1366 return ENXIO;
1367 }
1368
1369 if (error == EINTR || error == ERESTART) {
1370 if (d->bd_hbuf != NULL) {
1371 /*
1372 * Because we msleep, the hold buffer might
1373 * be filled when we wake up. Avoid rotating
1374 * in this case.
1375 */
1376 break;
1377 }
1378 if (d->bd_slen != 0) {
1379 /*
1380 * Sometimes we may be interrupted often and
1381 * the sleep above will not timeout.
1382 * Regardless, we should rotate the buffers
1383 * if there's any new data pending and
1384 * return it.
1385 */
1386 ROTATE_BUFFERS(d);
1387 break;
1388 }
1389 bpf_release_d(d);
1390 lck_mtx_unlock(bpf_mlock);
1391 if (error == ERESTART) {
1392 os_log(OS_LOG_DEFAULT, "%s: bpf%d ERESTART to EINTR",
1393 __func__, d->bd_dev_minor);
1394 error = EINTR;
1395 }
1396 return error;
1397 }
1398 if (error == EWOULDBLOCK) {
1399 /*
1400 * On a timeout, return what's in the buffer,
1401 * which may be nothing. If there is something
1402 * in the store buffer, we can rotate the buffers.
1403 */
1404 if (d->bd_hbuf) {
1405 /*
1406 * We filled up the buffer in between
1407 * getting the timeout and arriving
1408 * here, so we don't need to rotate.
1409 */
1410 break;
1411 }
1412
1413 if (d->bd_slen == 0) {
1414 bpf_release_d(d);
1415 lck_mtx_unlock(bpf_mlock);
1416 return 0;
1417 }
1418 ROTATE_BUFFERS(d);
1419 break;
1420 }
1421 }
1422 /*
1423 * At this point, we know we have something in the hold slot.
1424 */
1425
1426 /*
1427 * Set the hold buffer read. So we do not
1428 * rotate the buffers until the hold buffer
1429 * read is complete. Also to avoid issues resulting
1430 * from page faults during disk sleep (<rdar://problem/13436396>).
1431 */
1432 d->bd_hbuf_read = true;
1433 hbuf = d->bd_hbuf;
1434 hbuf_len = d->bd_hlen;
1435 flags = d->bd_flags;
1436 d->bd_bcs.bcs_total_read += d->bd_hcnt;
1437 lck_mtx_unlock(bpf_mlock);
1438
1439 /*
1440 * Before we move data to userland, we fill out the extended
1441 * header fields.
1442 */
1443 if (flags & BPF_EXTENDED_HDR) {
1444 char *p;
1445
1446 p = hbuf;
1447 while (p < hbuf + hbuf_len) {
1448 struct bpf_hdr_ext *ehp;
1449 uint32_t flowid;
1450 struct so_procinfo soprocinfo;
1451 int found = 0;
1452
1453 ehp = (struct bpf_hdr_ext *)(void *)p;
1454 if ((flowid = ehp->bh_flowid) != 0) {
1455 if (ehp->bh_flags & BPF_HDR_EXT_FLAGS_TCP) {
1456 ehp->bh_flags &= ~BPF_HDR_EXT_FLAGS_TCP;
1457 found = inp_findinpcb_procinfo(&tcbinfo,
1458 flowid, &soprocinfo);
1459 } else if (ehp->bh_flags == BPF_HDR_EXT_FLAGS_UDP) {
1460 ehp->bh_flags &= ~BPF_HDR_EXT_FLAGS_UDP;
1461 found = inp_findinpcb_procinfo(&udbinfo,
1462 flowid, &soprocinfo);
1463 }
1464 if (found == 1) {
1465 ehp->bh_pid = soprocinfo.spi_pid;
1466 strbufcpy(ehp->bh_comm,
1467 soprocinfo.spi_proc_name);
1468 }
1469 ehp->bh_flowid = 0;
1470 }
1471
1472 if ((flags & BPF_FINALIZE_PKTAP) != 0 && ehp->bh_complen == 0) {
1473 struct pktap_header *pktaphdr;
1474
1475 pktaphdr = (struct pktap_header *)(void *)
1476 (p + BPF_WORDALIGN(ehp->bh_hdrlen));
1477
1478 bpf_finalize_pktap((struct bpf_hdr *) ehp,
1479 pktaphdr);
1480 }
1481 p += BPF_WORDALIGN(ehp->bh_hdrlen + ehp->bh_caplen);
1482 }
1483 } else if (flags & BPF_FINALIZE_PKTAP) {
1484 char *p;
1485
1486 p = hbuf;
1487
1488 while (p < hbuf + hbuf_len) {
1489 struct bpf_hdr *hp;
1490 struct pktap_header *pktaphdr;
1491
1492 hp = (struct bpf_hdr *)(void *)p;
1493
1494 /*
1495 * Cannot finalize a compressed pktap header as we may not have
1496 * all the fields present
1497 */
1498 if (d->bd_flags & BPF_COMP_ENABLED) {
1499 struct bpf_comp_hdr *hcp;
1500
1501 hcp = (struct bpf_comp_hdr *)(void *)p;
1502
1503 if (hcp->bh_complen != 0) {
1504 p += BPF_WORDALIGN(hcp->bh_hdrlen + hcp->bh_caplen);
1505 continue;
1506 }
1507 }
1508
1509 pktaphdr = (struct pktap_header *)(void *)
1510 (p + BPF_WORDALIGN(hp->bh_hdrlen));
1511
1512 bpf_finalize_pktap(hp, pktaphdr);
1513
1514 p += BPF_WORDALIGN(hp->bh_hdrlen + hp->bh_caplen);
1515 }
1516 }
1517
1518 /*
1519 * Move data from hold buffer into user space.
1520 * We know the entire buffer is transferred since
1521 * we checked above that the read buffer is bpf_bufsize bytes.
1522 */
1523 error = uiomove(hbuf, hbuf_len, uio);
1524
1525 lck_mtx_lock(bpf_mlock);
1526 /*
1527 * Make sure device is still opened
1528 */
1529 if ((d->bd_flags & BPF_CLOSING) != 0) {
1530 bpf_release_d(d);
1531 lck_mtx_unlock(bpf_mlock);
1532 return ENXIO;
1533 }
1534
1535 d->bd_hbuf_read = false;
1536 d->bd_fbuf = d->bd_hbuf;
1537 d->bd_hbuf = NULL;
1538 d->bd_hlen = 0;
1539 d->bd_hcnt = 0;
1540 wakeup((caddr_t)d);
1541
1542 bpf_release_d(d);
1543 lck_mtx_unlock(bpf_mlock);
1544 return error;
1545 }
1546
1547 /*
1548 * If there are processes sleeping on this descriptor, wake them up.
1549 */
1550 static void
bpf_wakeup(struct bpf_d * d)1551 bpf_wakeup(struct bpf_d *d)
1552 {
1553 if (d->bd_state == BPF_WAITING) {
1554 bpf_stop_timer(d);
1555 d->bd_state = BPF_IDLE;
1556 }
1557 wakeup((caddr_t)d);
1558 if (d->bd_async && d->bd_sig && d->bd_sigio) {
1559 pgsigio(d->bd_sigio, d->bd_sig);
1560 }
1561
1562 selwakeup(&d->bd_sel);
1563 if ((d->bd_flags & BPF_KNOTE)) {
1564 KNOTE(&d->bd_sel.si_note, 1);
1565 }
1566 }
1567
1568 static void
bpf_timed_out(void * arg,__unused void * dummy)1569 bpf_timed_out(void *arg, __unused void *dummy)
1570 {
1571 struct bpf_d *d = (struct bpf_d *)arg;
1572
1573 lck_mtx_lock(bpf_mlock);
1574 if (d->bd_state == BPF_WAITING) {
1575 /*
1576 * There's a select or kqueue waiting for this; if there's
1577 * now stuff to read, wake it up.
1578 */
1579 d->bd_state = BPF_TIMED_OUT;
1580 if (d->bd_slen != 0) {
1581 bpf_wakeup(d);
1582 }
1583 } else if (d->bd_state == BPF_DRAINING) {
1584 /*
1585 * A close is waiting for this to finish.
1586 * Mark it as finished, and wake the close up.
1587 */
1588 d->bd_state = BPF_IDLE;
1589 bpf_wakeup(d);
1590 }
1591 lck_mtx_unlock(bpf_mlock);
1592 }
1593
1594 /* keep in sync with bpf_movein above: */
1595 #define MAX_DATALINK_HDR_LEN (sizeof(struct firewire_header))
1596
1597 int
bpfwrite(dev_t dev,struct uio * uio,__unused int ioflag)1598 bpfwrite(dev_t dev, struct uio *uio, __unused int ioflag)
1599 {
1600 struct bpf_d *d;
1601 struct ifnet *ifp;
1602 mbuf_ref_t m = NULL;
1603 int error = 0;
1604 char dst_buf[SOCKADDR_HDR_LEN + MAX_DATALINK_HDR_LEN] = {};
1605 int bif_dlt;
1606 int bd_hdrcmplt;
1607 bpf_send_func bif_send;
1608
1609 lck_mtx_lock(bpf_mlock);
1610
1611 while (true) {
1612 d = bpf_dtab[minor(dev)];
1613 if (d == NULL || d == BPF_DEV_RESERVED ||
1614 (d->bd_flags & BPF_CLOSING) != 0) {
1615 lck_mtx_unlock(bpf_mlock);
1616 return ENXIO;
1617 }
1618
1619 if (d->bd_hbuf_write) {
1620 msleep((caddr_t)d, bpf_mlock, PRINET, "bpfwrite",
1621 NULL);
1622 } else {
1623 break;
1624 }
1625 }
1626 d->bd_hbuf_write = true;
1627
1628 bpf_acquire_d(d);
1629
1630 ++d->bd_wcount;
1631
1632 if (d->bd_bif == NULL) {
1633 error = ENXIO;
1634 goto done;
1635 }
1636
1637 ifp = d->bd_bif->bif_ifp;
1638
1639 if (IFNET_IS_MANAGEMENT(ifp) &&
1640 IOCurrentTaskHasEntitlement(MANAGEMENT_DATA_ENTITLEMENT) == false) {
1641 ++d->bd_wdcount;
1642 bpf_release_d(d);
1643 lck_mtx_unlock(bpf_mlock);
1644 return ENETDOWN;
1645 }
1646
1647 if ((ifp->if_flags & IFF_UP) == 0) {
1648 error = ENETDOWN;
1649 goto done;
1650 }
1651 int resid = (int)uio_resid(uio);
1652 if (resid <= 0) {
1653 error = resid == 0 ? 0 : EINVAL;
1654 os_log(OS_LOG_DEFAULT, "bpfwrite: resid %d error %d", resid, error);
1655 goto done;
1656 }
1657 SA(dst_buf)->sa_len = sizeof(dst_buf);
1658
1659 /*
1660 * geting variables onto stack before dropping the lock
1661 */
1662 bif_dlt = (int)d->bd_bif->bif_dlt;
1663 bd_hdrcmplt = d->bd_hdrcmplt;
1664 bool batch_write = (d->bd_flags & BPF_BATCH_WRITE) ? true : false;
1665
1666 if (batch_write) {
1667 error = bpf_movein_batch(uio, d, &m, bd_hdrcmplt ? NULL : SA(dst_buf));
1668 if (error != 0) {
1669 goto done;
1670 }
1671 } else {
1672 error = bpf_movein(uio, resid, d, &m, bd_hdrcmplt ? NULL : SA(dst_buf));
1673 if (error != 0) {
1674 goto done;
1675 }
1676 bpf_set_packet_service_class(m, d->bd_traffic_class);
1677 }
1678
1679 /* verify the device is still open */
1680 if ((d->bd_flags & BPF_CLOSING) != 0) {
1681 error = ENXIO;
1682 goto done;
1683 }
1684
1685 if (d->bd_bif == NULL || d->bd_bif->bif_ifp != ifp) {
1686 error = ENXIO;
1687 goto done;
1688 }
1689
1690 bif_send = d->bd_bif->bif_send;
1691
1692 lck_mtx_unlock(bpf_mlock);
1693
1694 if (bd_hdrcmplt) {
1695 if (bif_send) {
1696 /*
1697 * Send one packet at a time, the driver frees the mbuf
1698 * but we need to take care of the leftover
1699 */
1700 while (m != NULL && error == 0) {
1701 struct mbuf *next = m->m_nextpkt;
1702
1703 m->m_nextpkt = NULL;
1704 error = bif_send(ifp, bif_dlt, m);
1705 m = next;
1706 }
1707 } else {
1708 error = dlil_output(ifp, 0, m, NULL, NULL,
1709 DLIL_OUTPUT_FLAGS_RAW, NULL);
1710 /* Make sure we do not double free */
1711 m = NULL;
1712 }
1713 } else {
1714 error = dlil_output(ifp, PF_INET, m, NULL, SA(dst_buf),
1715 DLIL_OUTPUT_FLAGS_NONE, NULL);
1716 /* Make sure we do not double free */
1717 m = NULL;
1718 }
1719
1720 lck_mtx_lock(bpf_mlock);
1721 done:
1722 if (error != 0 && m != NULL) {
1723 ++d->bd_wdcount;
1724 }
1725 if (m != NULL) {
1726 m_freem_list(m);
1727 }
1728 d->bd_hbuf_write = false;
1729 wakeup((caddr_t)d);
1730 bpf_release_d(d);
1731 lck_mtx_unlock(bpf_mlock);
1732
1733 return error;
1734 }
1735
1736 /*
1737 * Reset a descriptor by flushing its packet buffer and clearing the
1738 * receive and drop counts.
1739 */
1740 static void
reset_d(struct bpf_d * d)1741 reset_d(struct bpf_d *d)
1742 {
1743 if (d->bd_hbuf_read) {
1744 panic("resetting buffers during read");
1745 }
1746
1747 if (d->bd_hbuf) {
1748 /* Free the hold buffer. */
1749 d->bd_fbuf = d->bd_hbuf;
1750 d->bd_hbuf = NULL;
1751 }
1752 d->bd_slen = 0;
1753 d->bd_hlen = 0;
1754 d->bd_scnt = 0;
1755 d->bd_hcnt = 0;
1756 d->bd_rcount = 0;
1757 d->bd_dcount = 0;
1758 d->bd_fcount = 0;
1759 d->bd_wcount = 0;
1760 d->bd_wdcount = 0;
1761
1762 d->bd_prev_slen = 0;
1763 }
1764
1765 static struct bpf_d *
bpf_get_device_from_uuid(uuid_t uuid)1766 bpf_get_device_from_uuid(uuid_t uuid)
1767 {
1768 unsigned int i;
1769
1770 for (i = 0; i < nbpfilter; i++) {
1771 struct bpf_d *d = bpf_dtab[i];
1772
1773 if (d == NULL || d == BPF_DEV_RESERVED ||
1774 (d->bd_flags & BPF_CLOSING) != 0) {
1775 continue;
1776 }
1777 if (uuid_compare(uuid, d->bd_uuid) == 0) {
1778 return d;
1779 }
1780 }
1781
1782 return NULL;
1783 }
1784
1785 /*
1786 * The BIOCSETUP command "atomically" attach to the interface and
1787 * copy the buffer from another interface. This minimizes the risk
1788 * of missing packet because this is done while holding
1789 * the BPF global lock
1790 */
1791 static int
bpf_setup(struct bpf_d * d_to,uuid_t uuid_from,ifnet_t ifp)1792 bpf_setup(struct bpf_d *d_to, uuid_t uuid_from, ifnet_t ifp)
1793 {
1794 struct bpf_d *d_from;
1795 int error = 0;
1796
1797 LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
1798
1799 /*
1800 * Sanity checks
1801 */
1802 d_from = bpf_get_device_from_uuid(uuid_from);
1803 if (d_from == NULL) {
1804 error = ENOENT;
1805 os_log_error(OS_LOG_DEFAULT,
1806 "%s: uuids not found error %d",
1807 __func__, error);
1808 return error;
1809 }
1810 if (d_from->bd_opened_by != d_to->bd_opened_by) {
1811 error = EACCES;
1812 os_log_error(OS_LOG_DEFAULT,
1813 "%s: processes not matching error %d",
1814 __func__, error);
1815 return error;
1816 }
1817
1818 /*
1819 * Prevent any read or write while copying
1820 */
1821 while (d_to->bd_hbuf_read || d_to->bd_hbuf_write) {
1822 msleep((caddr_t)d_to, bpf_mlock, PRINET, __func__, NULL);
1823 }
1824 d_to->bd_hbuf_read = true;
1825 d_to->bd_hbuf_write = true;
1826
1827 while (d_from->bd_hbuf_read || d_from->bd_hbuf_write) {
1828 msleep((caddr_t)d_from, bpf_mlock, PRINET, __func__, NULL);
1829 }
1830 d_from->bd_hbuf_read = true;
1831 d_from->bd_hbuf_write = true;
1832
1833 /*
1834 * Verify the devices have not been closed
1835 */
1836 if (d_to->bd_flags & BPF_CLOSING) {
1837 error = ENXIO;
1838 os_log_error(OS_LOG_DEFAULT,
1839 "%s: d_to is closing error %d",
1840 __func__, error);
1841 goto done;
1842 }
1843 if (d_from->bd_flags & BPF_CLOSING) {
1844 error = ENXIO;
1845 os_log_error(OS_LOG_DEFAULT,
1846 "%s: d_from is closing error %d",
1847 __func__, error);
1848 goto done;
1849 }
1850
1851 /*
1852 * For now require the same buffer size
1853 */
1854 if (d_from->bd_bufsize != d_to->bd_bufsize) {
1855 error = EINVAL;
1856 os_log_error(OS_LOG_DEFAULT,
1857 "%s: bufsizes not matching error %d",
1858 __func__, error);
1859 goto done;
1860 }
1861
1862 /*
1863 * Copy relevant options and flags
1864 */
1865 d_to->bd_flags = d_from->bd_flags & (BPF_EXTENDED_HDR | BPF_WANT_PKTAP |
1866 BPF_FINALIZE_PKTAP | BPF_TRUNCATE | BPF_PKTHDRV2 |
1867 BPF_COMP_REQ | BPF_COMP_ENABLED);
1868
1869 d_to->bd_headdrop = d_from->bd_headdrop;
1870
1871 /*
1872 * Allocate and copy the buffers
1873 */
1874 error = bpf_allocbufs(d_to);
1875 if (error != 0) {
1876 goto done;
1877 }
1878
1879 /*
1880 * Make sure the buffers are setup as expected by bpf_setif()
1881 */
1882 ASSERT(d_to->bd_hbuf == NULL);
1883 ASSERT(d_to->bd_sbuf != NULL);
1884 ASSERT(d_to->bd_fbuf != NULL);
1885
1886 /*
1887 * Copy the buffers and update the pointers and counts
1888 */
1889 memcpy(d_to->bd_sbuf, d_from->bd_sbuf, d_from->bd_slen);
1890 d_to->bd_slen = d_from->bd_slen;
1891 d_to->bd_scnt = d_from->bd_scnt;
1892
1893 if (d_from->bd_hbuf != NULL) {
1894 d_to->bd_hbuf = d_to->bd_fbuf;
1895 d_to->bd_fbuf = NULL;
1896 memcpy(d_to->bd_hbuf, d_from->bd_hbuf, d_from->bd_hlen);
1897 }
1898 d_to->bd_hlen = d_from->bd_hlen;
1899 d_to->bd_hcnt = d_from->bd_hcnt;
1900
1901 if (d_to->bd_flags & BPF_COMP_REQ) {
1902 ASSERT(d_to->bd_prev_sbuf != NULL);
1903 ASSERT(d_to->bd_prev_fbuf != NULL);
1904
1905 d_to->bd_prev_slen = d_from->bd_prev_slen;
1906 ASSERT(d_to->bd_prev_slen <= BPF_HDR_COMP_LEN_MAX);
1907 memcpy(d_to->bd_prev_sbuf, d_from->bd_prev_sbuf, BPF_HDR_COMP_LEN_MAX);
1908 }
1909
1910 d_to->bd_bcs = d_from->bd_bcs;
1911
1912 /*
1913 * Attach to the interface:
1914 * - don't reset the buffers
1915 * - we already prevent reads and writes
1916 * - the buffers are already allocated
1917 */
1918 error = bpf_setif(d_to, ifp, false, true, true);
1919 if (error != 0) {
1920 os_log_error(OS_LOG_DEFAULT,
1921 "%s: bpf_setif() failed error %d",
1922 __func__, error);
1923 goto done;
1924 }
1925 done:
1926 d_from->bd_hbuf_read = false;
1927 d_from->bd_hbuf_write = false;
1928 wakeup((caddr_t)d_from);
1929
1930 d_to->bd_hbuf_read = false;
1931 d_to->bd_hbuf_write = false;
1932 wakeup((caddr_t)d_to);
1933
1934 return error;
1935 }
1936
1937 #if DEVELOPMENT || DEBUG
1938 #define BPF_IOC_LIST \
1939 X(FIONREAD) \
1940 X(SIOCGIFADDR) \
1941 X(BIOCGBLEN) \
1942 X(BIOCSBLEN) \
1943 X(BIOCSETF32) \
1944 X(BIOCSETFNR32) \
1945 X(BIOCSETF64) \
1946 X(BIOCSETFNR64) \
1947 X(BIOCFLUSH) \
1948 X(BIOCPROMISC) \
1949 X(BIOCGDLT) \
1950 X(BIOCGDLTLIST) \
1951 X(BIOCSDLT) \
1952 X(BIOCGETIF) \
1953 X(BIOCSETIF) \
1954 X(BIOCSRTIMEOUT32) \
1955 X(BIOCSRTIMEOUT64) \
1956 X(BIOCGRTIMEOUT32) \
1957 X(BIOCGRTIMEOUT64) \
1958 X(BIOCGSTATS) \
1959 X(BIOCIMMEDIATE) \
1960 X(BIOCVERSION) \
1961 X(BIOCGHDRCMPLT) \
1962 X(BIOCSHDRCMPLT) \
1963 X(BIOCGSEESENT) \
1964 X(BIOCSSEESENT) \
1965 X(BIOCSETTC) \
1966 X(BIOCGETTC) \
1967 X(FIONBIO) \
1968 X(FIOASYNC) \
1969 X(BIOCSRSIG) \
1970 X(BIOCGRSIG) \
1971 X(BIOCSEXTHDR) \
1972 X(BIOCGIFATTACHCOUNT) \
1973 X(BIOCGWANTPKTAP) \
1974 X(BIOCSWANTPKTAP) \
1975 X(BIOCSHEADDROP) \
1976 X(BIOCGHEADDROP) \
1977 X(BIOCSTRUNCATE) \
1978 X(BIOCGETUUID) \
1979 X(BIOCSETUP) \
1980 X(BIOCSPKTHDRV2) \
1981 X(BIOCGHDRCOMP) \
1982 X(BIOCSHDRCOMP) \
1983 X(BIOCGHDRCOMPSTATS) \
1984 X(BIOCGHDRCOMPON) \
1985 X(BIOCGDIRECTION) \
1986 X(BIOCSDIRECTION) \
1987 X(BIOCSWRITEMAX) \
1988 X(BIOCGWRITEMAX) \
1989 X(BIOCGBATCHWRITE) \
1990 X(BIOCSBATCHWRITE) \
1991 X(BIOCGNOTSTAMP) \
1992 X(BIOCSNOTSTAMP)
1993
1994 static void
log_bpf_ioctl_str(struct bpf_d * d,u_long cmd)1995 log_bpf_ioctl_str(struct bpf_d *d, u_long cmd)
1996 {
1997 const char *p = NULL;
1998 char str[32];
1999
2000 #define X(x) case x: { p = #x ; printf("%s\n", p); break; }
2001 switch (cmd) {
2002 BPF_IOC_LIST
2003 }
2004 #undef X
2005 if (p == NULL) {
2006 snprintf(str, sizeof(str), "0x%08x", (unsigned int)cmd);
2007 p = str;
2008 }
2009 os_log(OS_LOG_DEFAULT, "bpfioctl bpf%u %s",
2010 d->bd_dev_minor, p);
2011 }
2012 #endif /* DEVELOPMENT || DEBUG */
2013
2014 /*
2015 * FIONREAD Check for read packet available.
2016 * SIOCGIFADDR Get interface address - convenient hook to driver.
2017 * BIOCGBLEN Get buffer len [for read()].
2018 * BIOCSETF Set ethernet read filter.
2019 * BIOCFLUSH Flush read packet buffer.
2020 * BIOCPROMISC Put interface into promiscuous mode.
2021 * BIOCGDLT Get link layer type.
2022 * BIOCGETIF Get interface name.
2023 * BIOCSETIF Set interface.
2024 * BIOCSRTIMEOUT Set read timeout.
2025 * BIOCGRTIMEOUT Get read timeout.
2026 * BIOCGSTATS Get packet stats.
2027 * BIOCIMMEDIATE Set immediate mode.
2028 * BIOCVERSION Get filter language version.
2029 * BIOCGHDRCMPLT Get "header already complete" flag
2030 * BIOCSHDRCMPLT Set "header already complete" flag
2031 * BIOCGSEESENT Get "see packets sent" flag
2032 * BIOCSSEESENT Set "see packets sent" flag
2033 * BIOCSETTC Set traffic class.
2034 * BIOCGETTC Get traffic class.
2035 * BIOCSEXTHDR Set "extended header" flag
2036 * BIOCSHEADDROP Drop head of the buffer if user is not reading
2037 * BIOCGHEADDROP Get "head-drop" flag
2038 */
2039 /* ARGSUSED */
2040 int
bpfioctl(dev_t dev,u_long cmd,caddr_t __sized_by (IOCPARM_LEN (cmd))addr,__unused int flags,struct proc * p)2041 bpfioctl(dev_t dev, u_long cmd, caddr_t __sized_by(IOCPARM_LEN(cmd)) addr,
2042 __unused int flags, struct proc *p)
2043 {
2044 struct bpf_d *d;
2045 int error = 0;
2046 u_int int_arg;
2047 struct ifreq ifr = {};
2048
2049 lck_mtx_lock(bpf_mlock);
2050 d = bpf_dtab[minor(dev)];
2051 if (d == NULL || d == BPF_DEV_RESERVED ||
2052 (d->bd_flags & BPF_CLOSING) != 0) {
2053 lck_mtx_unlock(bpf_mlock);
2054 return ENXIO;
2055 }
2056
2057 bpf_acquire_d(d);
2058
2059 if (d->bd_state == BPF_WAITING) {
2060 bpf_stop_timer(d);
2061 }
2062 d->bd_state = BPF_IDLE;
2063
2064 #if DEVELOPMENT || DEBUG
2065 if (bpf_debug > 0) {
2066 log_bpf_ioctl_str(d, cmd);
2067 }
2068 #endif /* DEVELOPMENT || DEBUG */
2069
2070 switch (cmd) {
2071 default:
2072 error = EINVAL;
2073 break;
2074
2075 /*
2076 * Check for read packet available.
2077 */
2078 case FIONREAD: { /* int */
2079 int n;
2080
2081 n = d->bd_slen;
2082 if (d->bd_hbuf && d->bd_hbuf_read) {
2083 n += d->bd_hlen;
2084 }
2085
2086 bcopy(&n, addr, sizeof(n));
2087 break;
2088 }
2089
2090 case SIOCGIFADDR: { /* struct ifreq */
2091 struct ifnet *ifp;
2092
2093 if (d->bd_bif == 0) {
2094 error = EINVAL;
2095 } else {
2096 ifp = d->bd_bif->bif_ifp;
2097 error = ifnet_ioctl(ifp, 0, cmd, addr);
2098 }
2099 break;
2100 }
2101
2102 /*
2103 * Get buffer len [for read()].
2104 */
2105 case BIOCGBLEN: { /* u_int */
2106 _CASSERT(sizeof(d->bd_bufsize) == sizeof(u_int));
2107 bcopy(&d->bd_bufsize, addr, sizeof(u_int));
2108 break;
2109 }
2110
2111 /*
2112 * Set buffer length.
2113 */
2114 case BIOCSBLEN: { /* u_int */
2115 u_int size;
2116
2117 if (d->bd_bif != 0 || (d->bd_flags & BPF_DETACHING)) {
2118 /*
2119 * Interface already attached, unable to change buffers
2120 */
2121 error = EINVAL;
2122 break;
2123 }
2124 bcopy(addr, &size, sizeof(size));
2125
2126 if (size > BPF_BUFSIZE_CAP) {
2127 d->bd_bufsize = BPF_BUFSIZE_CAP;
2128
2129 os_log_info(OS_LOG_DEFAULT,
2130 "bpf%d BIOCSBLEN capped to %u from %u",
2131 minor(dev), d->bd_bufsize, size);
2132 } else if (size < BPF_MINBUFSIZE) {
2133 d->bd_bufsize = BPF_MINBUFSIZE;
2134
2135 os_log_info(OS_LOG_DEFAULT,
2136 "bpf%d BIOCSBLEN bumped to %u from %u",
2137 minor(dev), d->bd_bufsize, size);
2138 } else {
2139 d->bd_bufsize = size;
2140
2141 os_log_info(OS_LOG_DEFAULT,
2142 "bpf%d BIOCSBLEN %u",
2143 minor(dev), d->bd_bufsize);
2144 }
2145
2146 /* It's a read/write ioctl */
2147 bcopy(&d->bd_bufsize, addr, sizeof(u_int));
2148 break;
2149 }
2150 /*
2151 * Set link layer read filter.
2152 */
2153 case BIOCSETF32:
2154 case BIOCSETFNR32: { /* struct bpf_program32 */
2155 struct bpf_program32 prg32;
2156
2157 bcopy(addr, &prg32, sizeof(prg32));
2158 error = bpf_setf(d, prg32.bf_len,
2159 CAST_USER_ADDR_T(prg32.bf_insns), cmd);
2160 break;
2161 }
2162
2163 case BIOCSETF64:
2164 case BIOCSETFNR64: { /* struct bpf_program64 */
2165 struct bpf_program64 prg64;
2166
2167 bcopy(addr, &prg64, sizeof(prg64));
2168 error = bpf_setf(d, prg64.bf_len, CAST_USER_ADDR_T(prg64.bf_insns), cmd);
2169 break;
2170 }
2171
2172 /*
2173 * Flush read packet buffer.
2174 */
2175 case BIOCFLUSH:
2176 while (d->bd_hbuf_read) {
2177 msleep((caddr_t)d, bpf_mlock, PRINET, "BIOCFLUSH",
2178 NULL);
2179 }
2180 if ((d->bd_flags & BPF_CLOSING) != 0) {
2181 error = ENXIO;
2182 break;
2183 }
2184 reset_d(d);
2185 break;
2186
2187 /*
2188 * Put interface into promiscuous mode.
2189 */
2190 case BIOCPROMISC:
2191 if (d->bd_bif == 0) {
2192 /*
2193 * No interface attached yet.
2194 */
2195 error = EINVAL;
2196 break;
2197 }
2198 if (d->bd_promisc == 0) {
2199 lck_mtx_unlock(bpf_mlock);
2200 error = ifnet_set_promiscuous(d->bd_bif->bif_ifp, 1);
2201 lck_mtx_lock(bpf_mlock);
2202 if (error == 0) {
2203 d->bd_promisc = 1;
2204 }
2205 }
2206 break;
2207
2208 /*
2209 * Get device parameters.
2210 */
2211 case BIOCGDLT: { /* u_int */
2212 if (d->bd_bif == 0) {
2213 error = EINVAL;
2214 } else {
2215 _CASSERT(sizeof(d->bd_bif->bif_dlt) == sizeof(u_int));
2216 bcopy(&d->bd_bif->bif_dlt, addr, sizeof(u_int));
2217 }
2218 break;
2219 }
2220
2221 /*
2222 * Get a list of supported data link types.
2223 */
2224 case BIOCGDLTLIST: /* struct bpf_dltlist */
2225 if (d->bd_bif == NULL) {
2226 error = EINVAL;
2227 } else {
2228 error = bpf_getdltlist(d, addr, p);
2229 }
2230 break;
2231
2232 /*
2233 * Set data link type.
2234 */
2235 case BIOCSDLT: /* u_int */
2236 if (d->bd_bif == NULL) {
2237 error = EINVAL;
2238 } else {
2239 u_int dlt;
2240
2241 bcopy(addr, &dlt, sizeof(dlt));
2242
2243 if (dlt == DLT_PKTAP &&
2244 !(d->bd_flags & BPF_WANT_PKTAP)) {
2245 dlt = DLT_RAW;
2246 }
2247 error = bpf_setdlt(d, dlt);
2248 }
2249 break;
2250
2251 /*
2252 * Get interface name.
2253 */
2254 case BIOCGETIF: /* struct ifreq */
2255 if (d->bd_bif == 0) {
2256 error = EINVAL;
2257 } else {
2258 struct ifnet *const ifp = d->bd_bif->bif_ifp;
2259
2260 snprintf(((struct ifreq *)(void *)addr)->ifr_name,
2261 sizeof(ifr.ifr_name), "%s", if_name(ifp));
2262 }
2263 break;
2264
2265 /*
2266 * Set interface.
2267 */
2268 case BIOCSETIF: { /* struct ifreq */
2269 ifnet_t ifp;
2270
2271 bcopy(addr, &ifr, sizeof(ifr));
2272 ifr.ifr_name[IFNAMSIZ - 1] = '\0';
2273 ifp = ifunit(__unsafe_null_terminated_from_indexable(ifr.ifr_name,
2274 &ifr.ifr_name[IFNAMSIZ - 1]));
2275 if (ifp == NULL) {
2276 error = ENXIO;
2277 } else {
2278 error = bpf_setif(d, ifp, true, false, false);
2279 }
2280 break;
2281 }
2282
2283 /*
2284 * Set read timeout.
2285 */
2286 case BIOCSRTIMEOUT32: { /* struct user32_timeval */
2287 struct user32_timeval _tv;
2288 struct timeval tv;
2289
2290 bcopy(addr, &_tv, sizeof(_tv));
2291 tv.tv_sec = _tv.tv_sec;
2292 tv.tv_usec = _tv.tv_usec;
2293
2294 /*
2295 * Subtract 1 tick from tvtohz() since this isn't
2296 * a one-shot timer.
2297 */
2298 if ((error = itimerfix(&tv)) == 0) {
2299 d->bd_rtout = tvtohz(&tv) - 1;
2300 }
2301 break;
2302 }
2303
2304 case BIOCSRTIMEOUT64: { /* struct user64_timeval */
2305 struct user64_timeval _tv;
2306 struct timeval tv;
2307
2308 bcopy(addr, &_tv, sizeof(_tv));
2309 tv.tv_sec = (__darwin_time_t)_tv.tv_sec;
2310 tv.tv_usec = _tv.tv_usec;
2311
2312 /*
2313 * Subtract 1 tick from tvtohz() since this isn't
2314 * a one-shot timer.
2315 */
2316 if ((error = itimerfix(&tv)) == 0) {
2317 d->bd_rtout = tvtohz(&tv) - 1;
2318 }
2319 break;
2320 }
2321
2322 /*
2323 * Get read timeout.
2324 */
2325 case BIOCGRTIMEOUT32: { /* struct user32_timeval */
2326 struct user32_timeval tv;
2327
2328 bzero(&tv, sizeof(tv));
2329 tv.tv_sec = d->bd_rtout / hz;
2330 tv.tv_usec = (d->bd_rtout % hz) * tick;
2331 bcopy(&tv, addr, sizeof(tv));
2332 break;
2333 }
2334
2335 case BIOCGRTIMEOUT64: { /* struct user64_timeval */
2336 struct user64_timeval tv;
2337
2338 bzero(&tv, sizeof(tv));
2339 tv.tv_sec = d->bd_rtout / hz;
2340 tv.tv_usec = (d->bd_rtout % hz) * tick;
2341 bcopy(&tv, addr, sizeof(tv));
2342 break;
2343 }
2344
2345 /*
2346 * Get packet stats.
2347 */
2348 case BIOCGSTATS: { /* struct bpf_stat */
2349 struct bpf_stat bs;
2350
2351 bzero(&bs, sizeof(bs));
2352 bs.bs_recv = (u_int)d->bd_rcount;
2353 bs.bs_drop = (u_int)d->bd_dcount;
2354 bcopy(&bs, addr, sizeof(bs));
2355 break;
2356 }
2357
2358 /*
2359 * Set immediate mode.
2360 */
2361 case BIOCIMMEDIATE: /* u_int */
2362 d->bd_immediate = *(u_char *)(void *)addr;
2363 break;
2364
2365 case BIOCVERSION: { /* struct bpf_version */
2366 struct bpf_version bv;
2367
2368 bzero(&bv, sizeof(bv));
2369 bv.bv_major = BPF_MAJOR_VERSION;
2370 bv.bv_minor = BPF_MINOR_VERSION;
2371 bcopy(&bv, addr, sizeof(bv));
2372 break;
2373 }
2374
2375 /*
2376 * Get "header already complete" flag
2377 */
2378 case BIOCGHDRCMPLT: { /* u_int */
2379 u_int *addr_int = (u_int *)(void *)addr;
2380 *addr_int = d->bd_hdrcmplt;
2381 break;
2382 }
2383
2384 /*
2385 * Set "header already complete" flag
2386 */
2387 case BIOCSHDRCMPLT: /* u_int */
2388 bcopy(addr, &int_arg, sizeof(int_arg));
2389 if (int_arg == 0 && (d->bd_flags & BPF_BATCH_WRITE)) {
2390 os_log(OS_LOG_DEFAULT,
2391 "bpf%u cannot set BIOCSHDRCMPLT when BIOCSBATCHWRITE is set",
2392 d->bd_dev_minor);
2393 error = EINVAL;
2394 break;
2395 }
2396 d->bd_hdrcmplt = int_arg ? 1 : 0;
2397 break;
2398
2399 /*
2400 * Get "see sent packets" flag
2401 */
2402 case BIOCGSEESENT: { /* u_int */
2403 int_arg = 0;
2404
2405 if (d->bd_direction & BPF_D_OUT) {
2406 int_arg = 1;
2407 }
2408 bcopy(&int_arg, addr, sizeof(u_int));
2409 break;
2410 }
2411 /*
2412 * Set "see sent packets" flag
2413 */
2414 case BIOCSSEESENT: { /* u_int */
2415 bcopy(addr, &int_arg, sizeof(u_int));
2416
2417 if (int_arg == 0) {
2418 d->bd_direction = BPF_D_IN;
2419 } else {
2420 d->bd_direction = BPF_D_INOUT;
2421 }
2422 break;
2423 }
2424 /*
2425 * Get direction of tapped packets that can be seen for reading
2426 */
2427 case BIOCGDIRECTION: { /* u_int */
2428 int_arg = d->bd_direction;
2429
2430 bcopy(&int_arg, addr, sizeof(u_int));
2431 break;
2432 }
2433 /*
2434 * Set direction of tapped packets that can be seen for reading
2435 */
2436 case BIOCSDIRECTION: { /* u_int */
2437 bcopy(addr, &int_arg, sizeof(u_int));
2438
2439 switch (int_arg) {
2440 case BPF_D_NONE:
2441 case BPF_D_IN:
2442 case BPF_D_OUT:
2443 case BPF_D_INOUT:
2444 d->bd_direction = int_arg;
2445 break;
2446 default:
2447 error = EINVAL;
2448 break;
2449 }
2450 break;
2451 }
2452 /*
2453 * Set traffic service class
2454 */
2455 case BIOCSETTC: { /* int */
2456 int tc;
2457
2458 bcopy(addr, &tc, sizeof(int));
2459 if (tc != 0 && (d->bd_flags & BPF_BATCH_WRITE)) {
2460 os_log(OS_LOG_DEFAULT,
2461 "bpf%u cannot set BIOCSETTC when BIOCSBATCHWRITE is set",
2462 d->bd_dev_minor);
2463 error = EINVAL;
2464 break;
2465 }
2466 error = bpf_set_traffic_class(d, tc);
2467 break;
2468 }
2469
2470 /*
2471 * Get traffic service class
2472 */
2473 case BIOCGETTC: { /* int */
2474 _CASSERT(sizeof(d->bd_traffic_class) == sizeof(int));
2475 bcopy(&d->bd_traffic_class, addr, sizeof(int));
2476 break;
2477 }
2478
2479 case FIONBIO: /* Non-blocking I/O; int */
2480 break;
2481
2482 case FIOASYNC: { /* Send signal on receive packets; int */
2483 _CASSERT(sizeof(d->bd_async) == sizeof(int));
2484 bcopy(addr, &d->bd_async, sizeof(int));
2485 break;
2486 }
2487
2488 case BIOCSRSIG: { /* Set receive signal; u_int */
2489 u_int sig;
2490
2491 bcopy(addr, &sig, sizeof(u_int));
2492
2493 if (sig >= NSIG) {
2494 error = EINVAL;
2495 } else {
2496 d->bd_sig = sig;
2497 }
2498 break;
2499 }
2500 case BIOCGRSIG: { /* u_int */
2501 _CASSERT(sizeof(d->bd_sig) == sizeof(u_int));
2502 bcopy(&d->bd_sig, addr, sizeof(u_int));
2503 break;
2504 }
2505
2506 case BIOCSEXTHDR: /* u_int */
2507 bcopy(addr, &int_arg, sizeof(int_arg));
2508 if (int_arg) {
2509 d->bd_flags |= BPF_EXTENDED_HDR;
2510 } else {
2511 d->bd_flags &= ~BPF_EXTENDED_HDR;
2512 }
2513 break;
2514
2515 case BIOCGIFATTACHCOUNT: { /* struct ifreq */
2516 ifnet_t ifp;
2517 struct bpf_if *bp;
2518
2519 bcopy(addr, &ifr, sizeof(ifr));
2520 ifr.ifr_name[IFNAMSIZ - 1] = '\0';
2521 ifp = ifunit(__unsafe_null_terminated_from_indexable(ifr.ifr_name,
2522 &ifr.ifr_name[IFNAMSIZ - 1]));
2523 if (ifp == NULL) {
2524 error = ENXIO;
2525 break;
2526 }
2527 ifr.ifr_intval = 0;
2528 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
2529 struct bpf_d *bpf_d;
2530
2531 if (bp->bif_ifp == NULL || bp->bif_ifp != ifp) {
2532 continue;
2533 }
2534 for (bpf_d = bp->bif_dlist; bpf_d;
2535 bpf_d = bpf_d->bd_next) {
2536 ifr.ifr_intval += 1;
2537 }
2538 }
2539 bcopy(&ifr, addr, sizeof(ifr));
2540 break;
2541 }
2542 case BIOCGWANTPKTAP: /* u_int */
2543 int_arg = d->bd_flags & BPF_WANT_PKTAP ? 1 : 0;
2544 bcopy(&int_arg, addr, sizeof(int_arg));
2545 break;
2546
2547 case BIOCSWANTPKTAP: /* u_int */
2548 bcopy(addr, &int_arg, sizeof(int_arg));
2549 if (int_arg) {
2550 d->bd_flags |= BPF_WANT_PKTAP;
2551 } else {
2552 d->bd_flags &= ~BPF_WANT_PKTAP;
2553 }
2554 break;
2555
2556 case BIOCSHEADDROP:
2557 bcopy(addr, &int_arg, sizeof(int_arg));
2558 d->bd_headdrop = int_arg ? 1 : 0;
2559 break;
2560
2561 case BIOCGHEADDROP: {
2562 u_int *addr_int = (uint *)(void *)addr;
2563 *addr_int = d->bd_headdrop;
2564 break;
2565 }
2566
2567 case BIOCSTRUNCATE:
2568 bcopy(addr, &int_arg, sizeof(int_arg));
2569 if (int_arg) {
2570 d->bd_flags |= BPF_TRUNCATE;
2571 } else {
2572 d->bd_flags &= ~BPF_TRUNCATE;
2573 }
2574 break;
2575
2576 case BIOCGETUUID: /* uuid_t */
2577 bcopy(&d->bd_uuid, addr, sizeof(uuid_t));
2578 break;
2579
2580 case BIOCSETUP: {
2581 struct bpf_setup_args bsa;
2582 ifnet_t ifp;
2583
2584 bcopy(addr, &bsa, sizeof(struct bpf_setup_args));
2585 bsa.bsa_ifname[IFNAMSIZ - 1] = 0;
2586 ifp = ifunit(__unsafe_null_terminated_from_indexable(bsa.bsa_ifname,
2587 &bsa.bsa_ifname[IFNAMSIZ - 1]));
2588 if (ifp == NULL) {
2589 error = ENXIO;
2590 os_log_error(OS_LOG_DEFAULT,
2591 "%s: ifnet not found for %s error %d",
2592 __func__, bsa.bsa_ifname, error);
2593 break;
2594 }
2595
2596 error = bpf_setup(d, bsa.bsa_uuid, ifp);
2597 break;
2598 }
2599 case BIOCSPKTHDRV2:
2600 bcopy(addr, &int_arg, sizeof(int_arg));
2601 if (int_arg != 0) {
2602 d->bd_flags |= BPF_PKTHDRV2;
2603 } else {
2604 d->bd_flags &= ~BPF_PKTHDRV2;
2605 }
2606 break;
2607
2608 case BIOCGPKTHDRV2:
2609 int_arg = d->bd_flags & BPF_PKTHDRV2 ? 1 : 0;
2610 bcopy(&int_arg, addr, sizeof(int_arg));
2611 break;
2612
2613 case BIOCGHDRCOMP:
2614 int_arg = d->bd_flags & BPF_COMP_REQ ? 1 : 0;
2615 bcopy(&int_arg, addr, sizeof(int_arg));
2616 break;
2617
2618 case BIOCSHDRCOMP:
2619 bcopy(addr, &int_arg, sizeof(int_arg));
2620 if (int_arg != 0 && int_arg != 1) {
2621 return EINVAL;
2622 }
2623 if (d->bd_bif != 0 || (d->bd_flags & BPF_DETACHING)) {
2624 /*
2625 * Interface already attached, unable to change buffers
2626 */
2627 error = EINVAL;
2628 break;
2629 }
2630 if (int_arg != 0) {
2631 d->bd_flags |= BPF_COMP_REQ;
2632 if (bpf_hdr_comp_enable != 0) {
2633 d->bd_flags |= BPF_COMP_ENABLED;
2634 }
2635 } else {
2636 d->bd_flags &= ~(BPF_COMP_REQ | BPF_COMP_ENABLED);
2637 }
2638 break;
2639
2640 case BIOCGHDRCOMPON:
2641 int_arg = d->bd_flags & BPF_COMP_ENABLED ? 1 : 0;
2642 bcopy(&int_arg, addr, sizeof(int_arg));
2643 break;
2644
2645 case BIOCGHDRCOMPSTATS: {
2646 struct bpf_comp_stats bcs = {};
2647
2648 bcs = d->bd_bcs;
2649
2650 bcopy(&bcs, addr, sizeof(bcs));
2651 break;
2652 }
2653 case BIOCSWRITEMAX:
2654 bcopy(addr, &int_arg, sizeof(int_arg));
2655 if (int_arg > BPF_WRITE_MAX) {
2656 os_log(OS_LOG_DEFAULT, "bpf%u bd_write_size_max %u too big",
2657 d->bd_dev_minor, d->bd_write_size_max);
2658 error = EINVAL;
2659 break;
2660 }
2661 d->bd_write_size_max = int_arg;
2662 break;
2663
2664 case BIOCGWRITEMAX:
2665 int_arg = d->bd_write_size_max;
2666 bcopy(&int_arg, addr, sizeof(int_arg));
2667 break;
2668
2669 case BIOCGBATCHWRITE: /* int */
2670 int_arg = d->bd_flags & BPF_BATCH_WRITE ? 1 : 0;
2671 bcopy(&int_arg, addr, sizeof(int_arg));
2672 break;
2673
2674 case BIOCSBATCHWRITE: /* int */
2675 bcopy(addr, &int_arg, sizeof(int_arg));
2676 if (int_arg != 0) {
2677 if (d->bd_hdrcmplt == 0) {
2678 os_log(OS_LOG_DEFAULT,
2679 "bpf%u cannot set BIOCSBATCHWRITE when BIOCSHDRCMPLT is not set",
2680 d->bd_dev_minor);
2681 error = EINVAL;
2682 break;
2683 }
2684 if (d->bd_traffic_class != 0) {
2685 os_log(OS_LOG_DEFAULT,
2686 "bpf%u cannot set BIOCSBATCHWRITE when BIOCSETTC is set",
2687 d->bd_dev_minor);
2688 error = EINVAL;
2689 break;
2690 }
2691 d->bd_flags |= BPF_BATCH_WRITE;
2692 } else {
2693 d->bd_flags &= ~BPF_BATCH_WRITE;
2694 }
2695 break;
2696 case BIOCGNOTSTAMP:
2697 if (d->bd_tstamp == BPF_T_NONE) {
2698 int_arg = 1;
2699 } else {
2700 int_arg = 0;
2701 }
2702 bcopy(&int_arg, addr, sizeof(int_arg));
2703 break;
2704 case BIOCSNOTSTAMP:
2705 bcopy(addr, &int_arg, sizeof(int_arg));
2706 switch (int_arg) {
2707 case 0:
2708 d->bd_tstamp = BPF_T_MICROTIME;
2709 break;
2710 default:
2711 d->bd_tstamp = BPF_T_NONE;
2712 break;
2713 }
2714 break;
2715 case BIOCGDVRTIN:
2716 int_arg = d->bd_flags & BPF_DIVERT_IN ? 1 : 0;
2717 bcopy(&int_arg, addr, sizeof(int_arg));
2718 break;
2719 case BIOCSDVRTIN:
2720 if (d->bd_bif == NULL) {
2721 /*
2722 * No interface attached yet.
2723 */
2724 error = ENXIO;
2725 break;
2726 }
2727 bcopy(addr, &int_arg, sizeof(int_arg));
2728 if (int_arg == 0) {
2729 if ((d->bd_flags & BPF_DIVERT_IN) == 0) {
2730 error = EINVAL;
2731 break;
2732 }
2733 d->bd_flags &= ~BPF_DIVERT_IN;
2734 if_clear_xflags(d->bd_bif->bif_ifp, IFXF_DISABLE_INPUT);
2735 } else {
2736 if ((d->bd_flags & BPF_DIVERT_IN) != 0 ||
2737 (d->bd_bif->bif_ifp->if_xflags & IFXF_DISABLE_INPUT) != 0) {
2738 error = EALREADY;
2739 break;
2740 }
2741 d->bd_flags |= BPF_DIVERT_IN;
2742 if_set_xflags(d->bd_bif->bif_ifp, IFXF_DISABLE_INPUT);
2743 }
2744 break;
2745 }
2746
2747 bpf_release_d(d);
2748 lck_mtx_unlock(bpf_mlock);
2749
2750 return error;
2751 }
2752
2753 /*
2754 * Set d's packet filter program to fp. If this file already has a filter,
2755 * free it and replace it. Returns EINVAL for bogus requests.
2756 */
2757 static int
bpf_setf(struct bpf_d * d,u_int bf_len,user_addr_t bf_insns,u_long cmd)2758 bpf_setf(struct bpf_d *d, u_int bf_len, user_addr_t bf_insns,
2759 u_long cmd)
2760 {
2761 struct bpf_insn *fcode, *old;
2762 u_int flen, size;
2763
2764 while (d->bd_hbuf_read) {
2765 msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_setf", NULL);
2766 }
2767
2768 if ((d->bd_flags & BPF_CLOSING) != 0) {
2769 return ENXIO;
2770 }
2771
2772 old = d->bd_filter;
2773 if (bf_insns == USER_ADDR_NULL) {
2774 if (bf_len != 0) {
2775 return EINVAL;
2776 }
2777 d->bd_filter = NULL;
2778 d->bd_filter_len = 0;
2779 reset_d(d);
2780 if (old != 0) {
2781 kfree_data_addr(old);
2782 }
2783 return 0;
2784 }
2785 flen = bf_len;
2786 if (flen > BPF_MAXINSNS) {
2787 return EINVAL;
2788 }
2789
2790 size = flen * sizeof(struct bpf_insn);
2791 fcode = (struct bpf_insn *) kalloc_data(size, Z_WAITOK | Z_ZERO);
2792 if (fcode == NULL) {
2793 return ENOMEM;
2794 }
2795 if (copyin(bf_insns, (caddr_t)fcode, size) == 0 &&
2796 bpf_validate(fcode, (int)flen)) {
2797 d->bd_filter = fcode;
2798 d->bd_filter_len = flen;
2799
2800 if (cmd == BIOCSETF32 || cmd == BIOCSETF64) {
2801 reset_d(d);
2802 }
2803
2804 if (old != 0) {
2805 kfree_data_addr(old);
2806 }
2807
2808 return 0;
2809 }
2810 kfree_data(fcode, size);
2811 return EINVAL;
2812 }
2813
2814 /*
2815 * Detach a file from its current interface (if attached at all) and attach
2816 * to the interface indicated by the name stored in ifr.
2817 * Return an errno or 0.
2818 */
2819 static int
bpf_setif(struct bpf_d * d,ifnet_t theywant,bool do_reset,bool has_hbuf_read_write,bool has_bufs_allocated)2820 bpf_setif(struct bpf_d *d, ifnet_t theywant, bool do_reset, bool has_hbuf_read_write,
2821 bool has_bufs_allocated)
2822 {
2823 struct bpf_if *bp;
2824 int error;
2825
2826 while (!has_hbuf_read_write && (d->bd_hbuf_read || d->bd_hbuf_write)) {
2827 msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_setif", NULL);
2828 }
2829
2830 if ((d->bd_flags & BPF_CLOSING) != 0) {
2831 return ENXIO;
2832 }
2833
2834 /*
2835 * Look through attached interfaces for the named one.
2836 */
2837 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
2838 struct ifnet *ifp = bp->bif_ifp;
2839
2840 if (ifp == 0 || ifp != theywant) {
2841 continue;
2842 }
2843 /*
2844 * Do not use DLT_PKTAP, unless requested explicitly
2845 */
2846 if (bp->bif_dlt == DLT_PKTAP && !(d->bd_flags & BPF_WANT_PKTAP)) {
2847 continue;
2848 }
2849 /*
2850 * Skip the coprocessor interface
2851 */
2852 if (!intcoproc_unrestricted && IFNET_IS_INTCOPROC(ifp)) {
2853 continue;
2854 }
2855 /*
2856 * We found the requested interface.
2857 * Allocate the packet buffers.
2858 */
2859 if (has_bufs_allocated == false) {
2860 error = bpf_allocbufs(d);
2861 if (error != 0) {
2862 return error;
2863 }
2864 }
2865 /*
2866 * Detach if attached to something else.
2867 */
2868 if (bp != d->bd_bif) {
2869 if (d->bd_bif != NULL) {
2870 if (bpf_detachd(d) != 0) {
2871 return ENXIO;
2872 }
2873 }
2874 if (bpf_attachd(d, bp) != 0) {
2875 return ENXIO;
2876 }
2877 }
2878 if (do_reset) {
2879 reset_d(d);
2880 }
2881 os_log(OS_LOG_DEFAULT, "bpf%u attached to %s",
2882 d->bd_dev_minor, if_name(theywant));
2883 return 0;
2884 }
2885 /* Not found. */
2886 return ENXIO;
2887 }
2888
2889 /*
2890 * Get a list of available data link type of the interface.
2891 */
2892 static int
bpf_getdltlist(struct bpf_d * d,caddr_t __bidi_indexable addr,struct proc * p)2893 bpf_getdltlist(struct bpf_d *d, caddr_t __bidi_indexable addr, struct proc *p)
2894 {
2895 u_int n;
2896 int error;
2897 struct ifnet *ifp;
2898 struct bpf_if *bp;
2899 user_addr_t dlist;
2900 struct bpf_dltlist bfl;
2901
2902 bcopy(addr, &bfl, sizeof(bfl));
2903 if (proc_is64bit(p)) {
2904 dlist = (user_addr_t)bfl.bfl_u.bflu_pad;
2905 } else {
2906 dlist = CAST_USER_ADDR_T(bfl.bfl_u.bflu_list);
2907 }
2908
2909 ifp = d->bd_bif->bif_ifp;
2910 n = 0;
2911 error = 0;
2912
2913 for (bp = bpf_iflist; bp; bp = bp->bif_next) {
2914 if (bp->bif_ifp != ifp) {
2915 continue;
2916 }
2917 /*
2918 * Do not use DLT_PKTAP, unless requested explicitly
2919 */
2920 if (bp->bif_dlt == DLT_PKTAP && !(d->bd_flags & BPF_WANT_PKTAP)) {
2921 continue;
2922 }
2923 if (dlist != USER_ADDR_NULL) {
2924 if (n >= bfl.bfl_len) {
2925 return ENOMEM;
2926 }
2927 error = copyout(&bp->bif_dlt, dlist,
2928 sizeof(bp->bif_dlt));
2929 if (error != 0) {
2930 break;
2931 }
2932 dlist += sizeof(bp->bif_dlt);
2933 }
2934 n++;
2935 }
2936 bfl.bfl_len = n;
2937 bcopy(&bfl, addr, sizeof(bfl));
2938
2939 return error;
2940 }
2941
2942 /*
2943 * Set the data link type of a BPF instance.
2944 */
2945 static int
bpf_setdlt(struct bpf_d * d,uint32_t dlt)2946 bpf_setdlt(struct bpf_d *d, uint32_t dlt)
2947 {
2948 int error, opromisc;
2949 struct ifnet *ifp;
2950 struct bpf_if *bp;
2951
2952 if (d->bd_bif->bif_dlt == dlt) {
2953 return 0;
2954 }
2955
2956 while (d->bd_hbuf_read) {
2957 msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_setdlt", NULL);
2958 }
2959
2960 if ((d->bd_flags & BPF_CLOSING) != 0) {
2961 return ENXIO;
2962 }
2963
2964 ifp = d->bd_bif->bif_ifp;
2965 for (bp = bpf_iflist; bp; bp = bp->bif_next) {
2966 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) {
2967 /*
2968 * Do not use DLT_PKTAP, unless requested explicitly
2969 */
2970 if (bp->bif_dlt == DLT_PKTAP &&
2971 !(d->bd_flags & BPF_WANT_PKTAP)) {
2972 continue;
2973 }
2974 break;
2975 }
2976 }
2977 if (bp != NULL) {
2978 opromisc = d->bd_promisc;
2979 if (bpf_detachd(d) != 0) {
2980 return ENXIO;
2981 }
2982 error = bpf_attachd(d, bp);
2983 if (error != 0) {
2984 os_log_error(OS_LOG_DEFAULT,
2985 "bpf_setdlt: bpf%d bpf_attachd %s error %d",
2986 d->bd_dev_minor, if_name(bp->bif_ifp),
2987 error);
2988 return error;
2989 }
2990 reset_d(d);
2991 if (opromisc) {
2992 lck_mtx_unlock(bpf_mlock);
2993 error = ifnet_set_promiscuous(bp->bif_ifp, 1);
2994 lck_mtx_lock(bpf_mlock);
2995 if (error != 0) {
2996 os_log_error(OS_LOG_DEFAULT,
2997 "bpf_setdlt: bpf%d ifpromisc %s error %d",
2998 d->bd_dev_minor, if_name(bp->bif_ifp), error);
2999 } else {
3000 d->bd_promisc = 1;
3001 }
3002 }
3003 }
3004 return bp == NULL ? EINVAL : 0;
3005 }
3006
3007 static int
bpf_set_traffic_class(struct bpf_d * d,int tc)3008 bpf_set_traffic_class(struct bpf_d *d, int tc)
3009 {
3010 int error = 0;
3011
3012 if (!SO_VALID_TC(tc)) {
3013 error = EINVAL;
3014 } else {
3015 d->bd_traffic_class = tc;
3016 }
3017
3018 return error;
3019 }
3020
3021 static void
bpf_set_packet_service_class(struct mbuf * m,int tc)3022 bpf_set_packet_service_class(struct mbuf *m, int tc)
3023 {
3024 if (!(m->m_flags & M_PKTHDR)) {
3025 return;
3026 }
3027
3028 VERIFY(SO_VALID_TC(tc));
3029 (void) m_set_service_class(m, so_tc2msc(tc));
3030 }
3031
3032 /*
3033 * Support for select()
3034 *
3035 * Return true iff the specific operation will not block indefinitely.
3036 * Otherwise, return false but make a note that a selwakeup() must be done.
3037 */
3038 int
bpfselect(dev_t dev,int which,void * wql,struct proc * p)3039 bpfselect(dev_t dev, int which, void * wql, struct proc *p)
3040 {
3041 struct bpf_d *d;
3042 int ret = 0;
3043
3044 lck_mtx_lock(bpf_mlock);
3045
3046 d = bpf_dtab[minor(dev)];
3047 if (d == NULL || d == BPF_DEV_RESERVED ||
3048 (d->bd_flags & BPF_CLOSING) != 0) {
3049 lck_mtx_unlock(bpf_mlock);
3050 return ENXIO;
3051 }
3052
3053 bpf_acquire_d(d);
3054
3055 if (d->bd_bif == NULL) {
3056 bpf_release_d(d);
3057 lck_mtx_unlock(bpf_mlock);
3058 return ENXIO;
3059 }
3060
3061 while (d->bd_hbuf_read) {
3062 msleep((caddr_t)d, bpf_mlock, PRINET, "bpfselect", NULL);
3063 }
3064
3065 if ((d->bd_flags & BPF_CLOSING) != 0) {
3066 bpf_release_d(d);
3067 lck_mtx_unlock(bpf_mlock);
3068 return ENXIO;
3069 }
3070
3071 switch (which) {
3072 case FREAD:
3073 if (d->bd_hlen != 0 ||
3074 ((d->bd_immediate ||
3075 d->bd_state == BPF_TIMED_OUT) && d->bd_slen != 0)) {
3076 ret = 1; /* read has data to return */
3077 } else {
3078 /*
3079 * Read has no data to return.
3080 * Make the select wait, and start a timer if
3081 * necessary.
3082 */
3083 selrecord(p, &d->bd_sel, wql);
3084 bpf_start_timer(d);
3085 }
3086 break;
3087
3088 case FWRITE:
3089 /* can't determine whether a write would block */
3090 ret = 1;
3091 break;
3092 }
3093
3094 bpf_release_d(d);
3095 lck_mtx_unlock(bpf_mlock);
3096
3097 return ret;
3098 }
3099
3100 /*
3101 * Support for kevent() system call. Register EVFILT_READ filters and
3102 * reject all others.
3103 */
3104 int bpfkqfilter(dev_t dev, struct knote *kn);
3105 static void filt_bpfdetach(struct knote *);
3106 static int filt_bpfread(struct knote *, long);
3107 static int filt_bpftouch(struct knote *kn, struct kevent_qos_s *kev);
3108 static int filt_bpfprocess(struct knote *kn, struct kevent_qos_s *kev);
3109
3110 SECURITY_READ_ONLY_EARLY(struct filterops) bpfread_filtops = {
3111 .f_isfd = 1,
3112 .f_detach = filt_bpfdetach,
3113 .f_event = filt_bpfread,
3114 .f_touch = filt_bpftouch,
3115 .f_process = filt_bpfprocess,
3116 };
3117
3118 static int
filt_bpfread_common(struct knote * kn,struct kevent_qos_s * kev,struct bpf_d * d)3119 filt_bpfread_common(struct knote *kn, struct kevent_qos_s *kev, struct bpf_d *d)
3120 {
3121 int ready = 0;
3122 int64_t data = 0;
3123
3124 if (d->bd_immediate) {
3125 /*
3126 * If there's data in the hold buffer, it's the
3127 * amount of data a read will return.
3128 *
3129 * If there's no data in the hold buffer, but
3130 * there's data in the store buffer, a read will
3131 * immediately rotate the store buffer to the
3132 * hold buffer, the amount of data in the store
3133 * buffer is the amount of data a read will
3134 * return.
3135 *
3136 * If there's no data in either buffer, we're not
3137 * ready to read.
3138 */
3139 data = (d->bd_hlen == 0 || d->bd_hbuf_read ?
3140 d->bd_slen : d->bd_hlen);
3141 int64_t lowwat = knote_low_watermark(kn);
3142 if (lowwat > d->bd_bufsize) {
3143 lowwat = d->bd_bufsize;
3144 }
3145 ready = (data >= lowwat);
3146 } else {
3147 /*
3148 * If there's data in the hold buffer, it's the
3149 * amount of data a read will return.
3150 *
3151 * If there's no data in the hold buffer, but
3152 * there's data in the store buffer, if the
3153 * timer has expired a read will immediately
3154 * rotate the store buffer to the hold buffer,
3155 * so the amount of data in the store buffer is
3156 * the amount of data a read will return.
3157 *
3158 * If there's no data in either buffer, or there's
3159 * no data in the hold buffer and the timer hasn't
3160 * expired, we're not ready to read.
3161 */
3162 data = ((d->bd_hlen == 0 || d->bd_hbuf_read) &&
3163 d->bd_state == BPF_TIMED_OUT ? d->bd_slen : d->bd_hlen);
3164 ready = (data > 0);
3165 }
3166 if (!ready) {
3167 bpf_start_timer(d);
3168 } else if (kev) {
3169 knote_fill_kevent(kn, kev, data);
3170 }
3171
3172 return ready;
3173 }
3174
3175 int
bpfkqfilter(dev_t dev,struct knote * kn)3176 bpfkqfilter(dev_t dev, struct knote *kn)
3177 {
3178 struct bpf_d *d;
3179 int res;
3180
3181 /*
3182 * Is this device a bpf?
3183 */
3184 if (major(dev) != CDEV_MAJOR || kn->kn_filter != EVFILT_READ) {
3185 knote_set_error(kn, EINVAL);
3186 return 0;
3187 }
3188
3189 lck_mtx_lock(bpf_mlock);
3190
3191 d = bpf_dtab[minor(dev)];
3192
3193 if (d == NULL || d == BPF_DEV_RESERVED ||
3194 (d->bd_flags & BPF_CLOSING) != 0 ||
3195 d->bd_bif == NULL) {
3196 lck_mtx_unlock(bpf_mlock);
3197 knote_set_error(kn, ENXIO);
3198 return 0;
3199 }
3200
3201 kn->kn_filtid = EVFILTID_BPFREAD;
3202 knote_kn_hook_set_raw(kn, d);
3203 KNOTE_ATTACH(&d->bd_sel.si_note, kn);
3204 d->bd_flags |= BPF_KNOTE;
3205
3206 /* capture the current state */
3207 res = filt_bpfread_common(kn, NULL, d);
3208
3209 lck_mtx_unlock(bpf_mlock);
3210
3211 return res;
3212 }
3213
3214 static void
filt_bpfdetach(struct knote * kn)3215 filt_bpfdetach(struct knote *kn)
3216 {
3217 struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
3218
3219 lck_mtx_lock(bpf_mlock);
3220 if (d->bd_flags & BPF_KNOTE) {
3221 KNOTE_DETACH(&d->bd_sel.si_note, kn);
3222 d->bd_flags &= ~BPF_KNOTE;
3223 }
3224 lck_mtx_unlock(bpf_mlock);
3225 }
3226
3227 static int
filt_bpfread(struct knote * kn,long hint)3228 filt_bpfread(struct knote *kn, long hint)
3229 {
3230 #pragma unused(hint)
3231 struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
3232
3233 return filt_bpfread_common(kn, NULL, d);
3234 }
3235
3236 static int
filt_bpftouch(struct knote * kn,struct kevent_qos_s * kev)3237 filt_bpftouch(struct knote *kn, struct kevent_qos_s *kev)
3238 {
3239 struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
3240 int res;
3241
3242 lck_mtx_lock(bpf_mlock);
3243
3244 /* save off the lowat threshold and flag */
3245 kn->kn_sdata = kev->data;
3246 kn->kn_sfflags = kev->fflags;
3247
3248 /* output data will be re-generated here */
3249 res = filt_bpfread_common(kn, NULL, d);
3250
3251 lck_mtx_unlock(bpf_mlock);
3252
3253 return res;
3254 }
3255
3256 static int
filt_bpfprocess(struct knote * kn,struct kevent_qos_s * kev)3257 filt_bpfprocess(struct knote *kn, struct kevent_qos_s *kev)
3258 {
3259 struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
3260 int res;
3261
3262 lck_mtx_lock(bpf_mlock);
3263 res = filt_bpfread_common(kn, kev, d);
3264 lck_mtx_unlock(bpf_mlock);
3265
3266 return res;
3267 }
3268
3269 /*
3270 * Copy data from an mbuf chain into a buffer. This code is derived
3271 * from m_copydata in kern/uipc_mbuf.c.
3272 */
3273 static void
bpf_mcopy(struct mbuf * m,uint8_t * __sized_by (len)dst,size_t len,size_t offset)3274 bpf_mcopy(struct mbuf *m, uint8_t *__sized_by(len) dst, size_t len, size_t offset)
3275 {
3276 u_int count;
3277
3278 while (offset >= m->m_len) {
3279 offset -= m->m_len;
3280 m = m->m_next;
3281 if (m == NULL) {
3282 panic("bpf_mcopy");
3283 }
3284 continue;
3285 }
3286
3287 while (len > 0) {
3288 if (m == NULL) {
3289 panic("bpf_mcopy");
3290 }
3291 count = MIN(m->m_len - (u_int)offset, (u_int)len);
3292 bcopy(m_mtod_current(m) + offset, dst, count);
3293 m = m->m_next;
3294 dst += count;
3295 len -= count;
3296 offset = 0;
3297 }
3298 }
3299
3300 static inline void
bpf_tap_imp(ifnet_t ifp,u_int32_t dlt,struct bpf_packet * bpf_pkt,int outbound)3301 bpf_tap_imp(
3302 ifnet_t ifp,
3303 u_int32_t dlt,
3304 struct bpf_packet *bpf_pkt,
3305 int outbound)
3306 {
3307 struct bpf_d *d;
3308 u_int slen;
3309 struct bpf_if *bp;
3310
3311 /*
3312 * It's possible that we get here after the bpf descriptor has been
3313 * detached from the interface; in such a case we simply return.
3314 * Lock ordering is important since we can be called asynchronously
3315 * (from IOKit) to process an inbound packet; when that happens
3316 * we would have been holding its "gateLock" and will be acquiring
3317 * "bpf_mlock" upon entering this routine. Due to that, we release
3318 * "bpf_mlock" prior to calling ifnet_set_promiscuous (which will
3319 * acquire "gateLock" in the IOKit), in order to avoid a deadlock
3320 * when a ifnet_set_promiscuous request simultaneously collides with
3321 * an inbound packet being passed into the tap callback.
3322 */
3323 lck_mtx_lock(bpf_mlock);
3324 if (ifp->if_bpf == NULL) {
3325 lck_mtx_unlock(bpf_mlock);
3326 return;
3327 }
3328 for (bp = ifp->if_bpf; bp != NULL; bp = bp->bif_next) {
3329 if (bp->bif_ifp != ifp) {
3330 /* wrong interface */
3331 bp = NULL;
3332 break;
3333 }
3334 if (dlt == 0 || bp->bif_dlt == dlt) {
3335 /* tapping default DLT or DLT matches */
3336 break;
3337 }
3338 }
3339 if (bp == NULL) {
3340 goto done;
3341 }
3342 for (d = bp->bif_dlist; d != NULL; d = d->bd_next) {
3343 struct bpf_packet *bpf_pkt_saved = bpf_pkt;
3344 u_char *bpf_pkt_ptr = (u_char *)(struct bpf_packet *__bidi_indexable)bpf_pkt;
3345 struct bpf_packet bpf_pkt_tmp = {};
3346 struct pktap_header_buffer bpfp_header_tmp = {};
3347
3348 if (outbound && (d->bd_direction & BPF_D_OUT) == 0) {
3349 continue;
3350 }
3351 if (!outbound && (d->bd_direction & BPF_D_IN) == 0) {
3352 continue;
3353 }
3354
3355 ++d->bd_rcount;
3356 slen = bpf_filter(d->bd_filter, d->bd_filter_len,
3357 bpf_pkt_ptr,
3358 (u_int)bpf_pkt->bpfp_total_length, 0);
3359
3360 if (slen != 0) {
3361 if (bp->bif_ifp->if_type == IFT_PKTAP &&
3362 bp->bif_dlt == DLT_PKTAP) {
3363 if (d->bd_flags & BPF_TRUNCATE) {
3364 slen = min(slen, get_pkt_trunc_len(bpf_pkt));
3365 }
3366 /*
3367 * Need to copy the bpf_pkt because the conversion
3368 * to v2 pktap header modifies the content of the
3369 * bpfp_header
3370 */
3371 if ((d->bd_flags & BPF_PKTHDRV2) &&
3372 bpf_pkt->bpfp_header_length <= sizeof(bpfp_header_tmp)) {
3373 bpf_pkt_tmp = *bpf_pkt;
3374 bpf_pkt = &bpf_pkt_tmp;
3375
3376 memcpy(&bpfp_header_tmp, bpf_pkt->bpfp_header,
3377 bpf_pkt->bpfp_header_length);
3378
3379 bpf_pkt->bpfp_header = &bpfp_header_tmp;
3380 bpf_pkt->bpfp_header_length = bpf_pkt->bpfp_header_length;
3381
3382 convert_to_pktap_header_to_v2(bpf_pkt,
3383 !!(d->bd_flags & BPF_TRUNCATE));
3384 }
3385 }
3386 ++d->bd_fcount;
3387 catchpacket(d, bpf_pkt, slen, outbound);
3388 }
3389 bpf_pkt = bpf_pkt_saved;
3390 }
3391
3392 done:
3393 lck_mtx_unlock(bpf_mlock);
3394 }
3395
3396 static inline void
bpf_tap_mbuf(ifnet_t ifp,u_int32_t dlt,mbuf_t m,void * __sized_by (hlen)hdr,size_t hlen,int outbound)3397 bpf_tap_mbuf(
3398 ifnet_t ifp,
3399 u_int32_t dlt,
3400 mbuf_t m,
3401 void *__sized_by(hlen) hdr,
3402 size_t hlen,
3403 int outbound)
3404 {
3405 struct bpf_packet bpf_pkt;
3406 mbuf_ref_t m0;
3407
3408 if (ifp->if_bpf == NULL) {
3409 /* quickly check without taking lock */
3410 return;
3411 }
3412 bpf_pkt.bpfp_type = BPF_PACKET_TYPE_MBUF;
3413 bpf_pkt.bpfp_mbuf = m;
3414 bpf_pkt.bpfp_total_length = 0;
3415 for (m0 = m; m0 != NULL; m0 = m0->m_next) {
3416 bpf_pkt.bpfp_total_length += m0->m_len;
3417 }
3418 if (hdr != NULL) {
3419 bpf_pkt.bpfp_header = hdr;
3420 bpf_pkt.bpfp_header_length = hlen;
3421 bpf_pkt.bpfp_total_length += hlen;
3422 } else {
3423 bpf_pkt.bpfp_header = NULL;
3424 bpf_pkt.bpfp_header_length = 0;
3425 }
3426 bpf_tap_imp(ifp, dlt, &bpf_pkt, outbound);
3427 }
3428
3429 void
bpf_tap_out(ifnet_t ifp,u_int32_t dlt,mbuf_t m,void * __sized_by (hlen)hdr,size_t hlen)3430 bpf_tap_out(
3431 ifnet_t ifp,
3432 u_int32_t dlt,
3433 mbuf_t m,
3434 void *__sized_by(hlen) hdr,
3435 size_t hlen)
3436 {
3437 bpf_tap_mbuf(ifp, dlt, m, hdr, hlen, 1);
3438 }
3439
3440 void
bpf_tap_in(ifnet_t ifp,u_int32_t dlt,mbuf_t m,void * __sized_by (hlen)hdr,size_t hlen)3441 bpf_tap_in(
3442 ifnet_t ifp,
3443 u_int32_t dlt,
3444 mbuf_t m,
3445 void *__sized_by(hlen) hdr,
3446 size_t hlen)
3447 {
3448 bpf_tap_mbuf(ifp, dlt, m, hdr, hlen, 0);
3449 }
3450
3451 /* Callback registered with Ethernet driver. */
3452 static int
bpf_tap_callback(struct ifnet * ifp,struct mbuf * m)3453 bpf_tap_callback(struct ifnet *ifp, struct mbuf *m)
3454 {
3455 bpf_tap_mbuf(ifp, 0, m, NULL, 0, mbuf_pkthdr_rcvif(m) == NULL);
3456
3457 return 0;
3458 }
3459
3460 #if SKYWALK
3461 #include <skywalk/os_skywalk_private.h>
3462
3463 static void
bpf_pktcopy(kern_packet_t pkt,uint8_t * __sized_by (len)dst,size_t len,size_t offset)3464 bpf_pktcopy(kern_packet_t pkt, uint8_t *__sized_by(len) dst, size_t len, size_t offset)
3465 {
3466 kern_buflet_t buflet = NULL;
3467 size_t count;
3468
3469 while (len > 0) {
3470 uint8_t *addr;
3471 uint32_t buflet_length;
3472 uint32_t buflet_offset;
3473 uint32_t limit;
3474
3475 buflet = kern_packet_get_next_buflet(pkt, buflet);
3476 VERIFY(buflet != NULL);
3477 limit = kern_buflet_get_data_limit(buflet);
3478 buflet_offset = kern_buflet_get_data_offset(buflet);
3479 addr = __unsafe_forge_bidi_indexable(uint8_t *,
3480 (uintptr_t)kern_buflet_get_data_address(buflet) + buflet_offset,
3481 limit - buflet_offset);
3482 VERIFY(addr != NULL);
3483 buflet_length = kern_buflet_get_data_length(buflet);
3484 if (offset >= buflet_length) {
3485 offset -= buflet_length;
3486 continue;
3487 }
3488 count = MIN(buflet_length - offset, len);
3489 bcopy((void *)(addr + offset), (void *)dst, count);
3490 dst += count;
3491 len -= count;
3492 offset = 0;
3493 }
3494 }
3495
3496 static inline void
bpf_tap_packet(ifnet_t ifp,u_int32_t dlt,kern_packet_t pkt,void * __sized_by (hlen)hdr,size_t hlen,int outbound)3497 bpf_tap_packet(
3498 ifnet_t ifp,
3499 u_int32_t dlt,
3500 kern_packet_t pkt,
3501 void *__sized_by(hlen) hdr,
3502 size_t hlen,
3503 int outbound)
3504 {
3505 struct bpf_packet bpf_pkt;
3506 struct mbuf * m;
3507
3508 if (ifp->if_bpf == NULL) {
3509 /* quickly check without taking lock */
3510 return;
3511 }
3512 m = kern_packet_get_mbuf(pkt);
3513 if (m != NULL) {
3514 bpf_pkt.bpfp_type = BPF_PACKET_TYPE_MBUF;
3515 bpf_pkt.bpfp_mbuf = m;
3516 bpf_pkt.bpfp_total_length = m_length(m);
3517 } else {
3518 bpf_pkt.bpfp_type = BPF_PACKET_TYPE_PKT;
3519 bpf_pkt.bpfp_pkt = pkt;
3520 if (PKT_ADDR(pkt)->pkt_pflags & PKT_F_TRUNCATED) {
3521 struct __kern_buflet *bft = kern_packet_get_next_buflet(pkt, NULL);
3522 bpf_pkt.bpfp_total_length = kern_buflet_get_data_length(bft);
3523 } else {
3524 bpf_pkt.bpfp_total_length = kern_packet_get_data_length(pkt);
3525 }
3526 }
3527 bpf_pkt.bpfp_header = hdr;
3528 bpf_pkt.bpfp_header_length = hlen;
3529 if (hlen != 0) {
3530 bpf_pkt.bpfp_total_length += hlen;
3531 }
3532 bpf_tap_imp(ifp, dlt, &bpf_pkt, outbound);
3533 }
3534
3535 void
bpf_tap_packet_out(ifnet_t ifp,u_int32_t dlt,kern_packet_t pkt,void * __sized_by (hlen)hdr,size_t hlen)3536 bpf_tap_packet_out(
3537 ifnet_t ifp,
3538 u_int32_t dlt,
3539 kern_packet_t pkt,
3540 void *__sized_by(hlen) hdr,
3541 size_t hlen)
3542 {
3543 bpf_tap_packet(ifp, dlt, pkt, hdr, hlen, 1);
3544 }
3545
3546 void
bpf_tap_packet_in(ifnet_t ifp,u_int32_t dlt,kern_packet_t pkt,void * __sized_by (hlen)hdr,size_t hlen)3547 bpf_tap_packet_in(
3548 ifnet_t ifp,
3549 u_int32_t dlt,
3550 kern_packet_t pkt,
3551 void *__sized_by(hlen) hdr,
3552 size_t hlen)
3553 {
3554 bpf_tap_packet(ifp, dlt, pkt, hdr, hlen, 0);
3555 }
3556
3557 #endif /* SKYWALK */
3558
3559 static errno_t
bpf_copydata(struct bpf_packet * pkt,size_t off,size_t len,void * __sized_by (len)out_data)3560 bpf_copydata(struct bpf_packet *pkt, size_t off, size_t len, void *__sized_by(len) out_data)
3561 {
3562 errno_t err = 0;
3563 if (pkt->bpfp_type == BPF_PACKET_TYPE_MBUF) {
3564 err = mbuf_copydata(pkt->bpfp_mbuf, off, len, out_data);
3565 #if SKYWALK
3566 } else if (pkt->bpfp_type == BPF_PACKET_TYPE_PKT) {
3567 err = kern_packet_copy_bytes(pkt->bpfp_pkt, off, len, out_data);
3568 #endif /* SKYWALK */
3569 } else {
3570 err = EINVAL;
3571 }
3572
3573 return err;
3574 }
3575
3576 static void
copy_bpf_packet_offset(struct bpf_packet * pkt,uint8_t * __sized_by (len)dst,size_t len,size_t offset)3577 copy_bpf_packet_offset(struct bpf_packet * pkt, uint8_t *__sized_by(len) dst, size_t len, size_t offset)
3578 {
3579 /* copy the optional header */
3580 if (offset < pkt->bpfp_header_length) {
3581 size_t count = MIN(len, pkt->bpfp_header_length - offset);
3582 caddr_t src = pkt->bpfp_header;
3583 bcopy(src + offset, dst, count);
3584 dst += count;
3585 len -= count;
3586 offset = 0;
3587 } else {
3588 offset -= pkt->bpfp_header_length;
3589 }
3590
3591 if (len == 0) {
3592 /* nothing past the header */
3593 return;
3594 }
3595 /* copy the packet */
3596 switch (pkt->bpfp_type) {
3597 case BPF_PACKET_TYPE_MBUF:
3598 bpf_mcopy(pkt->bpfp_mbuf, dst, len, offset);
3599 break;
3600 #if SKYWALK
3601 case BPF_PACKET_TYPE_PKT:
3602 bpf_pktcopy(pkt->bpfp_pkt, dst, len, offset);
3603 break;
3604 #endif /* SKYWALK */
3605 default:
3606 break;
3607 }
3608 }
3609
3610 static void
copy_bpf_packet(struct bpf_packet * pkt,uint8_t * __sized_by (len)dst,size_t len)3611 copy_bpf_packet(struct bpf_packet * pkt, uint8_t *__sized_by(len) dst, size_t len)
3612 {
3613 copy_bpf_packet_offset(pkt, dst, len, 0);
3614 }
3615
3616 static uint32_t
get_esp_trunc_len(__unused struct bpf_packet * pkt,__unused uint32_t off,const uint32_t remaining_caplen)3617 get_esp_trunc_len(__unused struct bpf_packet *pkt, __unused uint32_t off,
3618 const uint32_t remaining_caplen)
3619 {
3620 /*
3621 * For some reason tcpdump expects to have one byte beyond the ESP header
3622 */
3623 uint32_t trunc_len = ESP_HDR_SIZE + 1;
3624
3625 if (trunc_len > remaining_caplen) {
3626 return remaining_caplen;
3627 }
3628
3629 return trunc_len;
3630 }
3631
3632 static uint32_t
get_isakmp_trunc_len(__unused struct bpf_packet * pkt,__unused uint32_t off,const uint32_t remaining_caplen)3633 get_isakmp_trunc_len(__unused struct bpf_packet *pkt, __unused uint32_t off,
3634 const uint32_t remaining_caplen)
3635 {
3636 /*
3637 * Include the payload generic header
3638 */
3639 uint32_t trunc_len = ISAKMP_HDR_SIZE;
3640
3641 if (trunc_len > remaining_caplen) {
3642 return remaining_caplen;
3643 }
3644
3645 return trunc_len;
3646 }
3647
3648 static uint32_t
get_isakmp_natt_trunc_len(struct bpf_packet * pkt,uint32_t off,const uint32_t remaining_caplen)3649 get_isakmp_natt_trunc_len(struct bpf_packet *pkt, uint32_t off,
3650 const uint32_t remaining_caplen)
3651 {
3652 int err = 0;
3653 uint32_t trunc_len = 0;
3654 char payload[remaining_caplen];
3655
3656 err = bpf_copydata(pkt, off, remaining_caplen, payload);
3657 if (err != 0) {
3658 return remaining_caplen;
3659 }
3660 /*
3661 * They are three cases:
3662 * - IKE: payload start with 4 bytes header set to zero before ISAKMP header
3663 * - keep alive: 1 byte payload
3664 * - otherwise it's ESP
3665 */
3666 if (remaining_caplen >= 4 &&
3667 payload[0] == 0 && payload[1] == 0 &&
3668 payload[2] == 0 && payload[3] == 0) {
3669 trunc_len = 4 + get_isakmp_trunc_len(pkt, off + 4, remaining_caplen - 4);
3670 } else if (remaining_caplen == 1) {
3671 trunc_len = 1;
3672 } else {
3673 trunc_len = get_esp_trunc_len(pkt, off, remaining_caplen);
3674 }
3675
3676 if (trunc_len > remaining_caplen) {
3677 return remaining_caplen;
3678 }
3679
3680 return trunc_len;
3681 }
3682
3683 static uint32_t
get_udp_trunc_len(struct bpf_packet * pkt,uint32_t off,const uint32_t remaining_caplen)3684 get_udp_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
3685 {
3686 int err = 0;
3687 uint32_t trunc_len = sizeof(struct udphdr); /* By default no UDP payload */
3688
3689 if (trunc_len >= remaining_caplen) {
3690 return remaining_caplen;
3691 }
3692
3693 struct udphdr udphdr;
3694 err = bpf_copydata(pkt, off, sizeof(struct udphdr), &udphdr);
3695 if (err != 0) {
3696 return remaining_caplen;
3697 }
3698
3699 u_short sport, dport;
3700
3701 sport = EXTRACT_SHORT(&udphdr.uh_sport);
3702 dport = EXTRACT_SHORT(&udphdr.uh_dport);
3703
3704 if (dport == PORT_DNS || sport == PORT_DNS) {
3705 /*
3706 * Full UDP payload for DNS
3707 */
3708 trunc_len = remaining_caplen;
3709 } else if ((sport == PORT_BOOTPS && dport == PORT_BOOTPC) ||
3710 (sport == PORT_BOOTPC && dport == PORT_BOOTPS)) {
3711 /*
3712 * Full UDP payload for BOOTP and DHCP
3713 */
3714 trunc_len = remaining_caplen;
3715 } else if (dport == PORT_ISAKMP && sport == PORT_ISAKMP) {
3716 /*
3717 * Return the ISAKMP header
3718 */
3719 trunc_len += get_isakmp_trunc_len(pkt, off + sizeof(struct udphdr),
3720 remaining_caplen - sizeof(struct udphdr));
3721 } else if (dport == PORT_ISAKMP_NATT && sport == PORT_ISAKMP_NATT) {
3722 trunc_len += get_isakmp_natt_trunc_len(pkt, off + sizeof(struct udphdr),
3723 remaining_caplen - sizeof(struct udphdr));
3724 }
3725 if (trunc_len >= remaining_caplen) {
3726 return remaining_caplen;
3727 }
3728
3729 return trunc_len;
3730 }
3731
3732 static uint32_t
get_tcp_trunc_len(struct bpf_packet * pkt,uint32_t off,const uint32_t remaining_caplen)3733 get_tcp_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
3734 {
3735 int err = 0;
3736 uint32_t trunc_len = sizeof(struct tcphdr); /* By default no TCP payload */
3737 if (trunc_len >= remaining_caplen) {
3738 return remaining_caplen;
3739 }
3740
3741 struct tcphdr tcphdr;
3742 err = bpf_copydata(pkt, off, sizeof(struct tcphdr), &tcphdr);
3743 if (err != 0) {
3744 return remaining_caplen;
3745 }
3746
3747 u_short sport, dport;
3748 sport = EXTRACT_SHORT(&tcphdr.th_sport);
3749 dport = EXTRACT_SHORT(&tcphdr.th_dport);
3750
3751 if (dport == PORT_DNS || sport == PORT_DNS) {
3752 /*
3753 * Full TCP payload for DNS
3754 */
3755 trunc_len = remaining_caplen;
3756 } else {
3757 trunc_len = (uint16_t)(tcphdr.th_off << 2);
3758 }
3759 if (trunc_len >= remaining_caplen) {
3760 return remaining_caplen;
3761 }
3762
3763 return trunc_len;
3764 }
3765
3766 static uint32_t
get_proto_trunc_len(uint8_t proto,struct bpf_packet * pkt,uint32_t off,const uint32_t remaining_caplen)3767 get_proto_trunc_len(uint8_t proto, struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
3768 {
3769 uint32_t trunc_len;
3770
3771 switch (proto) {
3772 case IPPROTO_ICMP: {
3773 /*
3774 * Full IMCP payload
3775 */
3776 trunc_len = remaining_caplen;
3777 break;
3778 }
3779 case IPPROTO_ICMPV6: {
3780 /*
3781 * Full IMCPV6 payload
3782 */
3783 trunc_len = remaining_caplen;
3784 break;
3785 }
3786 case IPPROTO_IGMP: {
3787 /*
3788 * Full IGMP payload
3789 */
3790 trunc_len = remaining_caplen;
3791 break;
3792 }
3793 case IPPROTO_UDP: {
3794 trunc_len = get_udp_trunc_len(pkt, off, remaining_caplen);
3795 break;
3796 }
3797 case IPPROTO_TCP: {
3798 trunc_len = get_tcp_trunc_len(pkt, off, remaining_caplen);
3799 break;
3800 }
3801 case IPPROTO_ESP: {
3802 trunc_len = get_esp_trunc_len(pkt, off, remaining_caplen);
3803 break;
3804 }
3805 default: {
3806 /*
3807 * By default we only include the IP header
3808 */
3809 trunc_len = 0;
3810 break;
3811 }
3812 }
3813 if (trunc_len >= remaining_caplen) {
3814 return remaining_caplen;
3815 }
3816
3817 return trunc_len;
3818 }
3819
3820 static uint32_t
get_ip_trunc_len(struct bpf_packet * pkt,uint32_t off,const uint32_t remaining_caplen)3821 get_ip_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
3822 {
3823 int err = 0;
3824 uint32_t iplen = sizeof(struct ip);
3825 if (iplen >= remaining_caplen) {
3826 return remaining_caplen;
3827 }
3828
3829 struct ip iphdr;
3830 err = bpf_copydata(pkt, off, sizeof(struct ip), &iphdr);
3831 if (err != 0) {
3832 return remaining_caplen;
3833 }
3834
3835 uint8_t proto = 0;
3836
3837 iplen = (uint16_t)(iphdr.ip_hl << 2);
3838 if (iplen >= remaining_caplen) {
3839 return remaining_caplen;
3840 }
3841
3842 proto = iphdr.ip_p;
3843 iplen += get_proto_trunc_len(proto, pkt, off + iplen, remaining_caplen - iplen);
3844
3845 if (iplen >= remaining_caplen) {
3846 return remaining_caplen;
3847 }
3848
3849 return iplen;
3850 }
3851
3852 static uint32_t
get_ip6_trunc_len(struct bpf_packet * pkt,uint32_t off,const uint32_t remaining_caplen)3853 get_ip6_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
3854 {
3855 int err = 0;
3856 uint32_t iplen = sizeof(struct ip6_hdr);
3857 if (iplen >= remaining_caplen) {
3858 return remaining_caplen;
3859 }
3860
3861 struct ip6_hdr ip6hdr;
3862 err = bpf_copydata(pkt, off, sizeof(struct ip6_hdr), &ip6hdr);
3863 if (err != 0) {
3864 return remaining_caplen;
3865 }
3866
3867 uint8_t proto = 0;
3868
3869 /*
3870 * TBD: process the extension headers
3871 */
3872 proto = ip6hdr.ip6_nxt;
3873 iplen += get_proto_trunc_len(proto, pkt, off + iplen, remaining_caplen - iplen);
3874
3875 if (iplen >= remaining_caplen) {
3876 return remaining_caplen;
3877 }
3878
3879 return iplen;
3880 }
3881
3882 static uint32_t
get_ether_trunc_len(struct bpf_packet * pkt,uint32_t off,const uint32_t remaining_caplen)3883 get_ether_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
3884 {
3885 int err = 0;
3886 uint32_t ethlen = sizeof(struct ether_header);
3887 if (ethlen >= remaining_caplen) {
3888 return remaining_caplen;
3889 }
3890
3891 struct ether_header eh = {};
3892 err = bpf_copydata(pkt, off, sizeof(struct ether_header), &eh);
3893 if (err != 0) {
3894 return remaining_caplen;
3895 }
3896
3897 u_short type = EXTRACT_SHORT(&eh.ether_type);
3898 /* Include full ARP */
3899 if (type == ETHERTYPE_ARP) {
3900 ethlen = remaining_caplen;
3901 } else if (type == ETHERTYPE_IP) {
3902 ethlen += get_ip_trunc_len(pkt, off + sizeof(struct ether_header),
3903 remaining_caplen - ethlen);
3904 } else if (type == ETHERTYPE_IPV6) {
3905 ethlen += get_ip6_trunc_len(pkt, off + sizeof(struct ether_header),
3906 remaining_caplen - ethlen);
3907 } else {
3908 ethlen = MIN(BPF_MIN_PKT_SIZE, remaining_caplen);
3909 }
3910 return ethlen;
3911 }
3912
3913 static uint32_t
get_pkt_trunc_len(struct bpf_packet * pkt)3914 get_pkt_trunc_len(struct bpf_packet *pkt)
3915 {
3916 struct pktap_header *pktap = (struct pktap_header *) (pkt->bpfp_header);
3917 uint32_t in_pkt_len = 0;
3918 uint32_t out_pkt_len = 0;
3919 uint32_t tlen = 0;
3920 uint32_t pre_adjust; // L2 header not in mbuf or kern_packet
3921
3922 // bpfp_total_length must contain the BPF packet header
3923 assert3u(pkt->bpfp_total_length, >=, pkt->bpfp_header_length);
3924
3925 // The BPF packet header must contain the pktap header
3926 assert3u(pkt->bpfp_header_length, >=, pktap->pth_length);
3927
3928 // The pre frame length (L2 header) must be contained in the packet
3929 assert3u(pkt->bpfp_total_length, >=, pktap->pth_length + pktap->pth_frame_pre_length);
3930
3931 /*
3932 * pktap->pth_frame_pre_length is the L2 header length and accounts
3933 * for both L2 header in the packet payload and pre_adjust.
3934 *
3935 * pre_adjust represents an adjustment for a pseudo L2 header that is not
3936 * part of packet payload -- not in the mbuf or kern_packet -- and comes
3937 * just after the pktap header.
3938 *
3939 * pktap->pth_length is the size of the pktap header (exclude pre_adjust)
3940 *
3941 * pkt->bpfp_header_length is (pktap->pth_length + pre_adjust)
3942 */
3943 pre_adjust = (uint32_t)(pkt->bpfp_header_length - pktap->pth_length);
3944
3945 if (pktap->pth_iftype == IFT_ETHER) {
3946 /*
3947 * We need to parse the Ethernet header to find the network layer
3948 * protocol
3949 */
3950 in_pkt_len = (uint32_t)(pkt->bpfp_total_length - pktap->pth_length - pre_adjust);
3951
3952 out_pkt_len = get_ether_trunc_len(pkt, 0, in_pkt_len);
3953
3954 tlen = pktap->pth_length + pre_adjust + out_pkt_len;
3955 } else {
3956 /*
3957 * For other interface types, we only know to parse IPv4 and IPv6.
3958 *
3959 * To get to the beginning of the IPv4 or IPv6 packet, we need to to skip
3960 * over the L2 header that is the actual packet payload (mbuf or kern_packet)
3961 */
3962 uint32_t off; // offset past the L2 header in the actual packet payload
3963
3964 off = pktap->pth_frame_pre_length - pre_adjust;
3965
3966 in_pkt_len = (uint32_t)(pkt->bpfp_total_length - pktap->pth_length - pktap->pth_frame_pre_length);
3967
3968 if (pktap->pth_protocol_family == AF_INET) {
3969 out_pkt_len = get_ip_trunc_len(pkt, off, in_pkt_len);
3970 } else if (pktap->pth_protocol_family == AF_INET6) {
3971 out_pkt_len = get_ip6_trunc_len(pkt, off, in_pkt_len);
3972 } else {
3973 out_pkt_len = MIN(BPF_MIN_PKT_SIZE, in_pkt_len);
3974 }
3975 tlen = pktap->pth_length + pktap->pth_frame_pre_length + out_pkt_len;
3976 }
3977
3978 // Verify we do not overflow the buffer
3979 if (__improbable(tlen > pkt->bpfp_total_length)) {
3980 bool do_panic = bpf_debug != 0 ? true : false;
3981
3982 #if DEBUG
3983 do_panic = true;
3984 #endif /* DEBUG */
3985 if (do_panic) {
3986 panic("%s:%d tlen %u > bpfp_total_length %lu bpfp_header_length %lu pth_frame_pre_length %u pre_adjust %u in_pkt_len %u out_pkt_len %u",
3987 __func__, __LINE__,
3988 tlen, pkt->bpfp_total_length, pkt->bpfp_header_length, pktap->pth_frame_pre_length, pre_adjust, in_pkt_len, out_pkt_len);
3989 } else {
3990 os_log(OS_LOG_DEFAULT,
3991 "%s:%d tlen %u > bpfp_total_length %lu bpfp_header_length %lu pth_frame_pre_length %u pre_adjust %u in_pkt_len %u out_pkt_len %u",
3992 __func__, __LINE__,
3993 tlen, pkt->bpfp_total_length, pkt->bpfp_header_length, pktap->pth_frame_pre_length, pre_adjust, in_pkt_len, out_pkt_len);
3994 }
3995 bpf_trunc_overflow += 1;
3996 tlen = (uint32_t)pkt->bpfp_total_length;
3997 }
3998
3999 return tlen;
4000 }
4001
4002 static uint8_t
get_common_prefix_size(const void * __bidi_indexable a,const void * __bidi_indexable b,uint8_t max_bytes)4003 get_common_prefix_size(const void *__bidi_indexable a, const void *__bidi_indexable b, uint8_t max_bytes)
4004 {
4005 uint8_t max_words = max_bytes >> 2;
4006 const uint32_t *x = (const uint32_t *)a;
4007 const uint32_t *y = (const uint32_t *)b;
4008 uint8_t i;
4009
4010 for (i = 0; i < max_words; i++) {
4011 if (x[i] != y[i]) {
4012 break;
4013 }
4014 }
4015 return (uint8_t)(i << 2);
4016 }
4017
4018 /*
4019 * Move the packet data from interface memory (pkt) into the
4020 * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
4021 * otherwise 0.
4022 */
4023 static void
catchpacket(struct bpf_d * d,struct bpf_packet * pkt,u_int snaplen,int outbound)4024 catchpacket(struct bpf_d *d, struct bpf_packet * pkt,
4025 u_int snaplen, int outbound)
4026 {
4027 struct bpf_hdr *hp;
4028 struct bpf_hdr_ext *ehp;
4029 uint32_t totlen, curlen;
4030 uint32_t hdrlen, caplen;
4031 int do_wakeup = 0;
4032 u_char *payload;
4033 struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
4034
4035 hdrlen = (d->bd_flags & BPF_EXTENDED_HDR) ? d->bd_bif->bif_exthdrlen :
4036 (d->bd_flags & BPF_COMP_REQ) ? d->bd_bif->bif_comphdrlen:
4037 d->bd_bif->bif_hdrlen;
4038 /*
4039 * Figure out how many bytes to move. If the packet is
4040 * greater or equal to the snapshot length, transfer that
4041 * much. Otherwise, transfer the whole packet (unless
4042 * we hit the buffer size limit).
4043 */
4044 totlen = hdrlen + MIN(snaplen, (int)pkt->bpfp_total_length);
4045 if (totlen > d->bd_bufsize) {
4046 totlen = d->bd_bufsize;
4047 }
4048
4049 if (hdrlen > totlen) {
4050 return;
4051 }
4052
4053 /*
4054 * Round up the end of the previous packet to the next longword.
4055 */
4056 curlen = BPF_WORDALIGN(d->bd_slen);
4057 if (curlen + totlen > d->bd_bufsize) {
4058 /*
4059 * This packet will overflow the storage buffer.
4060 * Rotate the buffers if we can, then wakeup any
4061 * pending reads.
4062 *
4063 * We cannot rotate buffers if a read is in progress
4064 * so drop the packet
4065 */
4066 if (d->bd_hbuf_read) {
4067 ++d->bd_dcount;
4068 return;
4069 }
4070
4071 if (d->bd_fbuf == NULL) {
4072 if (d->bd_headdrop == 0) {
4073 /*
4074 * We haven't completed the previous read yet,
4075 * so drop the packet.
4076 */
4077 ++d->bd_dcount;
4078 return;
4079 }
4080 /*
4081 * Drop the hold buffer as it contains older packets
4082 */
4083 d->bd_dcount += d->bd_hcnt;
4084 d->bd_fbuf = d->bd_hbuf;
4085 ROTATE_BUFFERS(d);
4086 } else {
4087 ROTATE_BUFFERS(d);
4088 }
4089 do_wakeup = 1;
4090 curlen = 0;
4091 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
4092 /*
4093 * Immediate mode is set, or the read timeout has
4094 * already expired during a select call. A packet
4095 * arrived, so the reader should be woken up.
4096 */
4097 do_wakeup = 1;
4098 }
4099
4100 /*
4101 * Append the bpf header.
4102 */
4103 if (d->bd_tstamp != BPF_T_NONE) {
4104 microtime(&tv);
4105 }
4106 if (d->bd_flags & BPF_EXTENDED_HDR) {
4107 ehp = (struct bpf_hdr_ext *)(void *)(d->bd_sbuf + curlen);
4108 memset(ehp, 0, sizeof(*ehp));
4109 ehp->bh_tstamp.tv_sec = (int)tv.tv_sec;
4110 ehp->bh_tstamp.tv_usec = tv.tv_usec;
4111
4112 ehp->bh_datalen = (bpf_u_int32)pkt->bpfp_total_length;
4113 ehp->bh_hdrlen = (u_short)hdrlen;
4114 caplen = ehp->bh_caplen = totlen - hdrlen;
4115 payload = (u_char *)ehp + hdrlen;
4116
4117 if (outbound) {
4118 ehp->bh_flags |= BPF_HDR_EXT_FLAGS_DIR_OUT;
4119 } else {
4120 ehp->bh_flags |= BPF_HDR_EXT_FLAGS_DIR_IN;
4121 }
4122
4123 if (pkt->bpfp_type == BPF_PACKET_TYPE_MBUF) {
4124 mbuf_ref_t m = pkt->bpfp_mbuf;
4125
4126 if (outbound) {
4127 /* only do lookups on non-raw INPCB */
4128 if ((m->m_pkthdr.pkt_flags & (PKTF_FLOW_ID |
4129 PKTF_FLOW_LOCALSRC | PKTF_FLOW_RAWSOCK)) ==
4130 (PKTF_FLOW_ID | PKTF_FLOW_LOCALSRC) &&
4131 m->m_pkthdr.pkt_flowsrc == FLOWSRC_INPCB) {
4132 ehp->bh_flowid = m->m_pkthdr.pkt_flowid;
4133 if (m->m_pkthdr.pkt_proto == IPPROTO_TCP) {
4134 ehp->bh_flags |= BPF_HDR_EXT_FLAGS_TCP;
4135 } else if (m->m_pkthdr.pkt_proto == IPPROTO_UDP) {
4136 ehp->bh_flags |= BPF_HDR_EXT_FLAGS_UDP;
4137 }
4138 }
4139 ehp->bh_svc = so_svc2tc(m->m_pkthdr.pkt_svc);
4140 if (m->m_pkthdr.pkt_flags & PKTF_TCP_REXMT) {
4141 ehp->bh_pktflags |= BPF_PKTFLAGS_TCP_REXMT;
4142 }
4143 if (m->m_pkthdr.pkt_flags & PKTF_START_SEQ) {
4144 ehp->bh_pktflags |= BPF_PKTFLAGS_START_SEQ;
4145 }
4146 if (m->m_pkthdr.pkt_flags & PKTF_LAST_PKT) {
4147 ehp->bh_pktflags |= BPF_PKTFLAGS_LAST_PKT;
4148 }
4149 if (m->m_pkthdr.pkt_flags & PKTF_VALID_UNSENT_DATA) {
4150 ehp->bh_unsent_bytes =
4151 m->m_pkthdr.bufstatus_if;
4152 ehp->bh_unsent_snd =
4153 m->m_pkthdr.bufstatus_sndbuf;
4154 }
4155 } else {
4156 if (m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) {
4157 ehp->bh_pktflags |= BPF_PKTFLAGS_WAKE_PKT;
4158 }
4159 }
4160 #if SKYWALK
4161 } else {
4162 kern_packet_t kern_pkt = pkt->bpfp_pkt;
4163 packet_flowid_t flowid = 0;
4164
4165 if (outbound) {
4166 /*
4167 * Note: pp_init() asserts that kern_packet_svc_class_t is equivalent
4168 * to mbuf_svc_class_t
4169 */
4170 ehp->bh_svc = so_svc2tc((mbuf_svc_class_t)kern_packet_get_service_class(kern_pkt));
4171 if (kern_packet_get_transport_retransmit(kern_pkt)) {
4172 ehp->bh_pktflags |= BPF_PKTFLAGS_TCP_REXMT;
4173 }
4174 if (kern_packet_get_transport_last_packet(kern_pkt)) {
4175 ehp->bh_pktflags |= BPF_PKTFLAGS_LAST_PKT;
4176 }
4177 } else {
4178 if (kern_packet_get_wake_flag(kern_pkt)) {
4179 ehp->bh_pktflags |= BPF_PKTFLAGS_WAKE_PKT;
4180 }
4181 }
4182 ehp->bh_trace_tag = kern_packet_get_trace_tag(kern_pkt);
4183 if (kern_packet_get_flowid(kern_pkt, &flowid) == 0) {
4184 ehp->bh_flowid = flowid;
4185 }
4186 #endif /* SKYWALK */
4187 }
4188 } else {
4189 hp = (struct bpf_hdr *)(void *)(d->bd_sbuf + curlen);
4190 memset(hp, 0, BPF_WORDALIGN(sizeof(*hp)));
4191 hp->bh_tstamp.tv_sec = (int)tv.tv_sec;
4192 hp->bh_tstamp.tv_usec = tv.tv_usec;
4193 hp->bh_datalen = (bpf_u_int32)pkt->bpfp_total_length;
4194 hp->bh_hdrlen = (u_short)hdrlen;
4195 caplen = hp->bh_caplen = totlen - hdrlen;
4196 payload = (u_char *)hp + hdrlen;
4197 }
4198 if (d->bd_flags & BPF_COMP_REQ) {
4199 uint8_t common_prefix_size = 0;
4200 uint8_t copy_len = MIN((uint8_t)caplen, BPF_HDR_COMP_LEN_MAX);
4201
4202 copy_bpf_packet(pkt, (uint8_t *__bidi_indexable)d->bd_prev_fbuf, copy_len);
4203
4204 if (d->bd_prev_slen != 0) {
4205 common_prefix_size = get_common_prefix_size(d->bd_prev_fbuf,
4206 d->bd_prev_sbuf, MIN(copy_len, d->bd_prev_slen));
4207 }
4208
4209 if (d->bd_flags & BPF_COMP_ENABLED) {
4210 assert3u(caplen, >=, common_prefix_size);
4211 copy_bpf_packet_offset(pkt, payload, caplen - common_prefix_size,
4212 common_prefix_size);
4213 d->bd_slen = curlen + totlen - common_prefix_size;
4214 } else {
4215 copy_bpf_packet(pkt, payload, caplen);
4216 d->bd_slen = curlen + totlen;
4217 }
4218
4219 /*
4220 * Update the caplen only if compression is enabled -- the caller
4221 * must pay attention to bpf_hdr_comp_enable
4222 */
4223 if (d->bd_flags & BPF_EXTENDED_HDR) {
4224 ehp->bh_complen = common_prefix_size;
4225 if (d->bd_flags & BPF_COMP_ENABLED) {
4226 ehp->bh_caplen -= common_prefix_size;
4227 }
4228 } else {
4229 struct bpf_comp_hdr *hcp;
4230
4231 hcp = (struct bpf_comp_hdr *)(void *)(d->bd_sbuf + curlen);
4232 hcp->bh_complen = common_prefix_size;
4233 if (d->bd_flags & BPF_COMP_ENABLED) {
4234 hcp->bh_caplen -= common_prefix_size;
4235 }
4236 }
4237
4238 if (common_prefix_size > 0) {
4239 d->bd_bcs.bcs_total_compressed_prefix_size += common_prefix_size;
4240 if (common_prefix_size > d->bd_bcs.bcs_max_compressed_prefix_size) {
4241 d->bd_bcs.bcs_max_compressed_prefix_size = common_prefix_size;
4242 }
4243 d->bd_bcs.bcs_count_compressed_prefix += 1;
4244 } else {
4245 d->bd_bcs.bcs_count_no_common_prefix += 1;
4246 }
4247
4248 /* The current compression buffer becomes the previous one */
4249 caddr_t tmp = d->bd_prev_sbuf;
4250 d->bd_prev_sbuf = d->bd_prev_fbuf;
4251 d->bd_prev_slen = copy_len;
4252 d->bd_prev_fbuf = tmp;
4253 } else {
4254 /*
4255 * Copy the packet data into the store buffer and update its length.
4256 */
4257 copy_bpf_packet(pkt, payload, caplen);
4258 d->bd_slen = curlen + totlen;
4259 }
4260 d->bd_scnt += 1;
4261 d->bd_bcs.bcs_total_hdr_size += pkt->bpfp_header_length;
4262 d->bd_bcs.bcs_total_size += caplen;
4263
4264 if (do_wakeup) {
4265 bpf_wakeup(d);
4266 }
4267 }
4268
4269 static void
bpf_freebufs(struct bpf_d * d)4270 bpf_freebufs(struct bpf_d *d)
4271 {
4272 if (d->bd_sbuf != NULL) {
4273 kfree_data_addr(d->bd_sbuf);
4274 }
4275 if (d->bd_hbuf != NULL) {
4276 kfree_data_addr(d->bd_hbuf);
4277 }
4278 if (d->bd_fbuf != NULL) {
4279 kfree_data_addr(d->bd_fbuf);
4280 }
4281
4282 if (d->bd_prev_sbuf != NULL) {
4283 kfree_data_addr(d->bd_prev_sbuf);
4284 }
4285 if (d->bd_prev_fbuf != NULL) {
4286 kfree_data_addr(d->bd_prev_fbuf);
4287 }
4288 }
4289 /*
4290 * Initialize all nonzero fields of a descriptor.
4291 */
4292 static int
bpf_allocbufs(struct bpf_d * d)4293 bpf_allocbufs(struct bpf_d *d)
4294 {
4295 bpf_freebufs(d);
4296
4297 d->bd_fbuf = kalloc_data(d->bd_bufsize, Z_WAITOK | Z_ZERO);
4298 if (d->bd_fbuf == NULL) {
4299 goto nobufs;
4300 }
4301
4302 d->bd_sbuf = kalloc_data(d->bd_bufsize, Z_WAITOK | Z_ZERO);
4303 if (d->bd_sbuf == NULL) {
4304 goto nobufs;
4305 }
4306 d->bd_slen = 0;
4307 d->bd_hlen = 0;
4308 d->bd_scnt = 0;
4309 d->bd_hcnt = 0;
4310
4311 d->bd_prev_slen = 0;
4312 if (d->bd_flags & BPF_COMP_REQ) {
4313 d->bd_prev_sbuf = kalloc_data(BPF_HDR_COMP_LEN_MAX, Z_WAITOK | Z_ZERO);
4314 if (d->bd_prev_sbuf == NULL) {
4315 goto nobufs;
4316 }
4317 d->bd_prev_fbuf = kalloc_data(BPF_HDR_COMP_LEN_MAX, Z_WAITOK | Z_ZERO);
4318 if (d->bd_prev_fbuf == NULL) {
4319 goto nobufs;
4320 }
4321 }
4322 return 0;
4323 nobufs:
4324 bpf_freebufs(d);
4325 return ENOMEM;
4326 }
4327
4328 /*
4329 * Free buffers currently in use by a descriptor.
4330 * Called on close.
4331 */
4332 static void
bpf_freed(struct bpf_d * d)4333 bpf_freed(struct bpf_d *d)
4334 {
4335 /*
4336 * We don't need to lock out interrupts since this descriptor has
4337 * been detached from its interface and it yet hasn't been marked
4338 * free.
4339 */
4340 if (d->bd_hbuf_read || d->bd_hbuf_write) {
4341 panic("bpf buffer freed during read/write");
4342 }
4343
4344 bpf_freebufs(d);
4345
4346 if (d->bd_filter) {
4347 kfree_data_addr_sized_by(d->bd_filter, d->bd_filter_len);
4348 }
4349 }
4350
4351 /*
4352 * Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *)
4353 * in the driver's softc; dlt is the link layer type; hdrlen is the fixed
4354 * size of the link header (variable length headers not yet supported).
4355 */
4356 void
bpfattach(struct ifnet * ifp,u_int dlt,u_int hdrlen)4357 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
4358 {
4359 bpf_attach(ifp, dlt, hdrlen, NULL, NULL);
4360 }
4361
4362 errno_t
bpf_attach(ifnet_t ifp,u_int32_t dlt,u_int32_t hdrlen,bpf_send_func send,bpf_tap_func tap)4363 bpf_attach(
4364 ifnet_t ifp,
4365 u_int32_t dlt,
4366 u_int32_t hdrlen,
4367 bpf_send_func send,
4368 bpf_tap_func tap)
4369 {
4370 struct bpf_if *bp;
4371 struct bpf_if *bp_new;
4372 struct bpf_if *bp_before_first = NULL;
4373 struct bpf_if *bp_first = NULL;
4374 struct bpf_if *bp_last = NULL;
4375 boolean_t found;
4376
4377 /*
4378 * Z_NOFAIL will cause a panic if the allocation fails
4379 */
4380 bp_new = kalloc_type(struct bpf_if, Z_WAITOK | Z_NOFAIL | Z_ZERO);
4381
4382 lck_mtx_lock(bpf_mlock);
4383
4384 /*
4385 * Check if this interface/dlt is already attached. Remember the
4386 * first and last attachment for this interface, as well as the
4387 * element before the first attachment.
4388 */
4389 found = FALSE;
4390 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
4391 if (bp->bif_ifp != ifp) {
4392 if (bp_first != NULL) {
4393 /* no more elements for this interface */
4394 break;
4395 }
4396 bp_before_first = bp;
4397 } else {
4398 if (bp->bif_dlt == dlt) {
4399 found = TRUE;
4400 break;
4401 }
4402 if (bp_first == NULL) {
4403 bp_first = bp;
4404 }
4405 bp_last = bp;
4406 }
4407 }
4408 if (found) {
4409 lck_mtx_unlock(bpf_mlock);
4410 os_log_error(OS_LOG_DEFAULT,
4411 "bpfattach - %s with dlt %d is already attached",
4412 if_name(ifp), dlt);
4413 kfree_type(struct bpf_if, bp_new);
4414 return EEXIST;
4415 }
4416
4417 bp_new->bif_ifp = ifp;
4418 bp_new->bif_dlt = dlt;
4419 bp_new->bif_send = send;
4420 bp_new->bif_tap = tap;
4421
4422 if (bp_first == NULL) {
4423 /* No other entries for this ifp */
4424 bp_new->bif_next = bpf_iflist;
4425 bpf_iflist = bp_new;
4426 } else {
4427 if (ifnet_type(ifp) == IFT_ETHER && dlt == DLT_EN10MB) {
4428 /* Make this the first entry for this interface */
4429 if (bp_before_first != NULL) {
4430 /* point the previous to us */
4431 bp_before_first->bif_next = bp_new;
4432 } else {
4433 /* we're the new head */
4434 bpf_iflist = bp_new;
4435 }
4436 bp_new->bif_next = bp_first;
4437 } else {
4438 /* Add this after the last entry for this interface */
4439 bp_new->bif_next = bp_last->bif_next;
4440 bp_last->bif_next = bp_new;
4441 }
4442 }
4443
4444 /*
4445 * Compute the length of the bpf header. This is not necessarily
4446 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
4447 * that the network layer header begins on a longword boundary (for
4448 * performance reasons and to alleviate alignment restrictions).
4449 */
4450 bp_new->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
4451 bp_new->bif_exthdrlen = BPF_WORDALIGN(hdrlen +
4452 sizeof(struct bpf_hdr_ext)) - hdrlen;
4453 bp_new->bif_comphdrlen = BPF_WORDALIGN(hdrlen +
4454 sizeof(struct bpf_comp_hdr)) - hdrlen;
4455
4456 /* Take a reference on the interface */
4457 ifnet_reference(ifp);
4458
4459 lck_mtx_unlock(bpf_mlock);
4460
4461 return 0;
4462 }
4463
4464 /*
4465 * Detach bpf from an interface. This involves detaching each descriptor
4466 * associated with the interface, and leaving bd_bif NULL. Notify each
4467 * descriptor as it's detached so that any sleepers wake up and get
4468 * ENXIO.
4469 */
4470 void
bpfdetach(struct ifnet * ifp)4471 bpfdetach(struct ifnet *ifp)
4472 {
4473 struct bpf_if *bp, *bp_prev, *bp_next;
4474 struct bpf_d *d;
4475
4476 if (bpf_debug != 0) {
4477 os_log(OS_LOG_DEFAULT, "%s: %s", __func__, if_name(ifp));
4478 }
4479
4480 lck_mtx_lock(bpf_mlock);
4481
4482 /*
4483 * Build the list of devices attached to that interface
4484 * that we need to free while keeping the lock to maintain
4485 * the integrity of the interface list
4486 */
4487 bp_prev = NULL;
4488 for (bp = bpf_iflist; bp != NULL; bp = bp_next) {
4489 bp_next = bp->bif_next;
4490
4491 if (ifp != bp->bif_ifp) {
4492 bp_prev = bp;
4493 continue;
4494 }
4495 /* Unlink from the interface list */
4496 if (bp_prev) {
4497 bp_prev->bif_next = bp->bif_next;
4498 } else {
4499 bpf_iflist = bp->bif_next;
4500 }
4501
4502 /* Detach the devices attached to the interface */
4503 while ((d = bp->bif_dlist) != NULL) {
4504 /*
4505 * Take an extra reference to prevent the device
4506 * from being freed when bpf_detachd() releases
4507 * the reference for the interface list
4508 */
4509 bpf_acquire_d(d);
4510
4511 /*
4512 * Wait for active read and writes to complete
4513 */
4514 while (d->bd_hbuf_read || d->bd_hbuf_write) {
4515 msleep((caddr_t)d, bpf_mlock, PRINET, "bpfdetach", NULL);
4516 }
4517
4518 bpf_detachd(d);
4519 bpf_wakeup(d);
4520 bpf_release_d(d);
4521 }
4522 ifnet_release(ifp);
4523 }
4524
4525 lck_mtx_unlock(bpf_mlock);
4526 }
4527
4528 void
bpf_init(__unused void * unused)4529 bpf_init(__unused void *unused)
4530 {
4531 int maj;
4532
4533 /* bpf_comp_hdr is an overlay of bpf_hdr */
4534 _CASSERT(BPF_WORDALIGN(sizeof(struct bpf_hdr)) ==
4535 BPF_WORDALIGN(sizeof(struct bpf_comp_hdr)));
4536
4537 /* compression length must fits in a byte */
4538 _CASSERT(BPF_HDR_COMP_LEN_MAX <= UCHAR_MAX );
4539
4540 (void) PE_parse_boot_argn("bpf_hdr_comp", &bpf_hdr_comp_enable,
4541 sizeof(bpf_hdr_comp_enable));
4542
4543 if (bpf_devsw_installed == 0) {
4544 bpf_devsw_installed = 1;
4545 maj = cdevsw_add(CDEV_MAJOR, &bpf_cdevsw);
4546 if (maj == -1) {
4547 bpf_devsw_installed = 0;
4548 os_log_error(OS_LOG_DEFAULT,
4549 "bpf_init: failed to allocate a major number");
4550 return;
4551 }
4552
4553 for (int i = 0; i < NBPFILTER; i++) {
4554 bpf_make_dev_t(maj);
4555 }
4556 }
4557 }
4558
4559 static int
4560 sysctl_bpf_maxbufsize SYSCTL_HANDLER_ARGS
4561 {
4562 #pragma unused(arg1, arg2)
4563 int i, err;
4564
4565 i = bpf_maxbufsize;
4566
4567 err = sysctl_handle_int(oidp, &i, 0, req);
4568 if (err != 0 || req->newptr == USER_ADDR_NULL) {
4569 return err;
4570 }
4571
4572 if (i < 0 || i > BPF_BUFSIZE_CAP) {
4573 i = BPF_BUFSIZE_CAP;
4574 }
4575
4576 bpf_maxbufsize = i;
4577 return err;
4578 }
4579
4580 static int
4581 sysctl_bpf_bufsize_cap SYSCTL_HANDLER_ARGS
4582 {
4583 #pragma unused(arg1, arg2)
4584 int i, err;
4585
4586 i = BPF_BUFSIZE_CAP;
4587
4588 err = sysctl_handle_int(oidp, &i, 0, req);
4589 if (err != 0 || req->newptr == USER_ADDR_NULL) {
4590 return err;
4591 }
4592
4593 return err;
4594 }
4595
4596 /*
4597 * Fill filter statistics
4598 */
4599 static void
bpfstats_fill_xbpf(struct xbpf_d * d,struct bpf_d * bd)4600 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
4601 {
4602 LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
4603
4604 d->bd_structsize = sizeof(struct xbpf_d);
4605 d->bd_promisc = bd->bd_promisc != 0 ? 1 : 0;
4606 d->bd_immediate = d->bd_immediate != 0 ? 1 : 0;
4607 d->bd_hdrcmplt = bd->bd_hdrcmplt != 0 ? 1 : 0;
4608 d->bd_async = bd->bd_async != 0 ? 1 : 0;
4609 d->bd_headdrop = bd->bd_headdrop != 0 ? 1 : 0;
4610 d->bd_direction = (uint8_t)bd->bd_direction;
4611 d->bh_compreq = bd->bd_flags & BPF_COMP_REQ ? 1 : 0;
4612 d->bh_compenabled = bd->bd_flags & BPF_COMP_ENABLED ? 1 : 0;
4613 d->bd_exthdr = bd->bd_flags & BPF_EXTENDED_HDR ? 1 : 0;
4614 d->bd_trunc = bd->bd_flags & BPF_TRUNCATE ? 1 : 0;
4615 d->bd_pkthdrv2 = bd->bd_flags & BPF_PKTHDRV2 ? 1 : 0;
4616 d->bd_batch_write = bd->bd_flags & BPF_BATCH_WRITE ? 1 : 0;
4617 d->bd_divert_in = bd->bd_flags & BPF_DIVERT_IN ? 1 : 0;
4618
4619 d->bd_dev_minor = (uint8_t)bd->bd_dev_minor;
4620
4621 d->bd_sig = bd->bd_sig;
4622
4623 d->bd_rcount = bd->bd_rcount;
4624 d->bd_dcount = bd->bd_dcount;
4625 d->bd_fcount = bd->bd_fcount;
4626 d->bd_wcount = bd->bd_wcount;
4627 d->bd_wdcount = bd->bd_wdcount;
4628 d->bd_slen = bd->bd_slen;
4629 d->bd_hlen = bd->bd_hlen;
4630 d->bd_bufsize = bd->bd_bufsize;
4631 d->bd_pid = bd->bd_pid;
4632 if (bd->bd_bif != NULL && bd->bd_bif->bif_ifp != NULL) {
4633 strlcpy(d->bd_ifname,
4634 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
4635 }
4636
4637 d->bd_comp_count = bd->bd_bcs.bcs_count_compressed_prefix;
4638 d->bd_comp_size = bd->bd_bcs.bcs_total_compressed_prefix_size;
4639
4640 d->bd_scnt = bd->bd_scnt;
4641 d->bd_hcnt = bd->bd_hcnt;
4642
4643 d->bd_read_count = bd->bd_bcs.bcs_total_read;
4644 d->bd_fsize = bd->bd_bcs.bcs_total_size;
4645 }
4646
4647 /*
4648 * Handle `netstat -B' stats request
4649 */
4650 static int
4651 sysctl_bpf_stats SYSCTL_HANDLER_ARGS
4652 {
4653 int error;
4654 struct xbpf_d *xbdbuf;
4655 unsigned int x_cnt;
4656 vm_size_t buf_size;
4657
4658 if (req->oldptr == USER_ADDR_NULL) {
4659 return SYSCTL_OUT(req, 0, nbpfilter * sizeof(struct xbpf_d));
4660 }
4661 if (nbpfilter == 0) {
4662 return SYSCTL_OUT(req, 0, 0);
4663 }
4664 buf_size = req->oldlen;
4665 if (buf_size > BPF_MAX_DEVICES * sizeof(struct xbpf_d)) {
4666 buf_size = BPF_MAX_DEVICES * sizeof(struct xbpf_d);
4667 }
4668 xbdbuf = kalloc_data(buf_size, Z_WAITOK | Z_ZERO);
4669
4670 lck_mtx_lock(bpf_mlock);
4671 if (buf_size < (nbpfilter * sizeof(struct xbpf_d))) {
4672 lck_mtx_unlock(bpf_mlock);
4673 kfree_data(xbdbuf, buf_size);
4674 return ENOMEM;
4675 }
4676 x_cnt = 0;
4677 unsigned int i;
4678
4679 for (i = 0; i < nbpfilter; i++) {
4680 struct bpf_d *bd = bpf_dtab[i];
4681 struct xbpf_d *xbd;
4682
4683 if (bd == NULL || bd == BPF_DEV_RESERVED ||
4684 (bd->bd_flags & BPF_CLOSING) != 0) {
4685 continue;
4686 }
4687 VERIFY(x_cnt < nbpfilter);
4688
4689 xbd = &xbdbuf[x_cnt++];
4690 bpfstats_fill_xbpf(xbd, bd);
4691 }
4692 lck_mtx_unlock(bpf_mlock);
4693
4694 error = SYSCTL_OUT(req, xbdbuf, x_cnt * sizeof(struct xbpf_d));
4695 kfree_data(xbdbuf, buf_size);
4696 return error;
4697 }
4698