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      1 /*	$NetBSD: bpf.c,v 1.258 2024/10/20 14:03:51 mlelstv Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1990, 1991, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from the Stanford/CMU enet packet filter,
      8  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
      9  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
     10  * Berkeley Laboratory.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  *	@(#)bpf.c	8.4 (Berkeley) 1/9/95
     37  * static char rcsid[] =
     38  * "Header: bpf.c,v 1.67 96/09/26 22:00:52 leres Exp ";
     39  */
     40 
     41 #include <sys/cdefs.h>
     42 __KERNEL_RCSID(0, "$NetBSD: bpf.c,v 1.258 2024/10/20 14:03:51 mlelstv Exp $");
     43 
     44 #if defined(_KERNEL_OPT)
     45 #include "opt_bpf.h"
     46 #include "sl.h"
     47 #include "opt_net_mpsafe.h"
     48 #endif
     49 
     50 #include <sys/param.h>
     51 
     52 #include <sys/atomic.h>
     53 #include <sys/buf.h>
     54 #include <sys/conf.h>
     55 #include <sys/cpu.h>
     56 #include <sys/errno.h>
     57 #include <sys/file.h>
     58 #include <sys/filedesc.h>
     59 #include <sys/ioctl.h>
     60 #include <sys/kauth.h>
     61 #include <sys/kernel.h>
     62 #include <sys/lwp.h>
     63 #include <sys/mbuf.h>
     64 #include <sys/module.h>
     65 #include <sys/percpu.h>
     66 #include <sys/poll.h>
     67 #include <sys/proc.h>
     68 #include <sys/protosw.h>
     69 #include <sys/pserialize.h>
     70 #include <sys/queue.h>
     71 #include <sys/socket.h>
     72 #include <sys/stat.h>
     73 #include <sys/sysctl.h>
     74 #include <sys/syslog.h>
     75 #include <sys/systm.h>
     76 #include <sys/time.h>
     77 #include <sys/tty.h>
     78 #include <sys/uio.h>
     79 #include <sys/vnode.h>
     80 #include <sys/xcall.h>
     81 
     82 #include <net/bpf.h>
     83 #include <net/bpfdesc.h>
     84 #include <net/bpfjit.h>
     85 #include <net/if.h>
     86 #include <net/if_arc.h>
     87 #include <net/if_ether.h>
     88 #include <net/if_types.h>
     89 #include <net/slip.h>
     90 
     91 #include <netinet/if_inarp.h>
     92 #include <netinet/in.h>
     93 
     94 #include <compat/sys/sockio.h>
     95 
     96 #ifndef BPF_BUFSIZE
     97 /*
     98  * 4096 is too small for FDDI frames. 8192 is too small for gigabit Ethernet
     99  * jumbos (circa 9k), ATM, or Intel gig/10gig ethernet jumbos (16k).
    100  */
    101 # define BPF_BUFSIZE 32768
    102 #endif
    103 
    104 #define PRINET  26			/* interruptible */
    105 
    106 /*
    107  * The default read buffer size, and limit for BIOCSBLEN, is sysctl'able.
    108  * XXX the default values should be computed dynamically based
    109  * on available memory size and available mbuf clusters.
    110  */
    111 static int bpf_bufsize = BPF_BUFSIZE;
    112 static int bpf_maxbufsize = BPF_DFLTBUFSIZE;	/* XXX set dynamically, see above */
    113 static bool bpf_jit = false;
    114 
    115 struct bpfjit_ops bpfjit_module_ops = {
    116 	.bj_generate_code = NULL,
    117 	.bj_free_code = NULL
    118 };
    119 
    120 /*
    121  * Global BPF statistics returned by net.bpf.stats sysctl.
    122  */
    123 static struct percpu	*bpf_gstats_percpu; /* struct bpf_stat */
    124 
    125 #define BPF_STATINC(id)					\
    126 	{						\
    127 		struct bpf_stat *__stats =		\
    128 		    percpu_getref(bpf_gstats_percpu);	\
    129 		__stats->bs_##id++;			\
    130 		percpu_putref(bpf_gstats_percpu);	\
    131 	}
    132 
    133 /*
    134  * Locking notes:
    135  * - bpf_mtx (adaptive mutex) protects:
    136  *   - Gobal lists: bpf_iflist and bpf_dlist
    137  *   - struct bpf_if
    138  *   - bpf_close
    139  *   - bpf_psz (pserialize)
    140  * - struct bpf_d has two mutexes:
    141  *   - bd_buf_mtx (spin mutex) protects the buffers that can be accessed
    142  *     on packet tapping
    143  *   - bd_mtx (adaptive mutex) protects member variables other than the buffers
    144  * - Locking order: bpf_mtx => bpf_d#bd_mtx => bpf_d#bd_buf_mtx
    145  * - struct bpf_d obtained via fp->f_bpf in bpf_read and bpf_write is
    146  *   never freed because struct bpf_d is only freed in bpf_close and
    147  *   bpf_close never be called while executing bpf_read and bpf_write
    148  * - A filter that is assigned to bpf_d can be replaced with another filter
    149  *   while tapping packets, so it needs to be done atomically
    150  * - struct bpf_d is iterated on bpf_dlist with psz
    151  * - struct bpf_if is iterated on bpf_iflist with psz or psref
    152  */
    153 /*
    154  * Use a mutex to avoid a race condition between gathering the stats/peers
    155  * and opening/closing the device.
    156  */
    157 static kmutex_t bpf_mtx;
    158 
    159 static struct psref_class	*bpf_psref_class __read_mostly;
    160 static pserialize_t		bpf_psz;
    161 
    162 static inline void
    163 bpf_if_acquire(struct bpf_if *bp, struct psref *psref)
    164 {
    165 
    166 	psref_acquire(psref, &bp->bif_psref, bpf_psref_class);
    167 }
    168 
    169 static inline void
    170 bpf_if_release(struct bpf_if *bp, struct psref *psref)
    171 {
    172 
    173 	psref_release(psref, &bp->bif_psref, bpf_psref_class);
    174 }
    175 
    176 /*
    177  *  bpf_iflist is the list of interfaces; each corresponds to an ifnet
    178  *  bpf_dtab holds the descriptors, indexed by minor device #
    179  */
    180 static struct pslist_head bpf_iflist;
    181 static struct pslist_head bpf_dlist;
    182 
    183 /* Macros for bpf_d on bpf_dlist */
    184 #define BPF_DLIST_WRITER_INSERT_HEAD(__d)				\
    185 	PSLIST_WRITER_INSERT_HEAD(&bpf_dlist, (__d), bd_bpf_dlist_entry)
    186 #define BPF_DLIST_READER_FOREACH(__d)					\
    187 	PSLIST_READER_FOREACH((__d), &bpf_dlist, struct bpf_d,		\
    188 	    bd_bpf_dlist_entry)
    189 #define BPF_DLIST_WRITER_FOREACH(__d)					\
    190 	PSLIST_WRITER_FOREACH((__d), &bpf_dlist, struct bpf_d,		\
    191 	    bd_bpf_dlist_entry)
    192 #define BPF_DLIST_ENTRY_INIT(__d)					\
    193 	PSLIST_ENTRY_INIT((__d), bd_bpf_dlist_entry)
    194 #define BPF_DLIST_WRITER_REMOVE(__d)					\
    195 	PSLIST_WRITER_REMOVE((__d), bd_bpf_dlist_entry)
    196 #define BPF_DLIST_ENTRY_DESTROY(__d)					\
    197 	PSLIST_ENTRY_DESTROY((__d), bd_bpf_dlist_entry)
    198 
    199 /* Macros for bpf_if on bpf_iflist */
    200 #define BPF_IFLIST_WRITER_INSERT_HEAD(__bp)				\
    201 	PSLIST_WRITER_INSERT_HEAD(&bpf_iflist, (__bp), bif_iflist_entry)
    202 #define BPF_IFLIST_READER_FOREACH(__bp)					\
    203 	PSLIST_READER_FOREACH((__bp), &bpf_iflist, struct bpf_if,	\
    204 	    bif_iflist_entry)
    205 #define BPF_IFLIST_WRITER_FOREACH(__bp)					\
    206 	PSLIST_WRITER_FOREACH((__bp), &bpf_iflist, struct bpf_if,	\
    207 	    bif_iflist_entry)
    208 #define BPF_IFLIST_WRITER_REMOVE(__bp)					\
    209 	PSLIST_WRITER_REMOVE((__bp), bif_iflist_entry)
    210 #define BPF_IFLIST_ENTRY_INIT(__bp)					\
    211 	PSLIST_ENTRY_INIT((__bp), bif_iflist_entry)
    212 #define BPF_IFLIST_ENTRY_DESTROY(__bp)					\
    213 	PSLIST_ENTRY_DESTROY((__bp), bif_iflist_entry)
    214 
    215 /* Macros for bpf_d on bpf_if#bif_dlist_pslist */
    216 #define BPFIF_DLIST_READER_FOREACH(__d, __bp)				\
    217 	PSLIST_READER_FOREACH((__d), &(__bp)->bif_dlist_head, struct bpf_d, \
    218 	    bd_bif_dlist_entry)
    219 #define BPFIF_DLIST_WRITER_INSERT_HEAD(__bp, __d)			\
    220 	PSLIST_WRITER_INSERT_HEAD(&(__bp)->bif_dlist_head, (__d),	\
    221 	    bd_bif_dlist_entry)
    222 #define BPFIF_DLIST_WRITER_REMOVE(__d)					\
    223 	PSLIST_WRITER_REMOVE((__d), bd_bif_dlist_entry)
    224 #define BPFIF_DLIST_ENTRY_INIT(__d)					\
    225 	PSLIST_ENTRY_INIT((__d), bd_bif_dlist_entry)
    226 #define	BPFIF_DLIST_READER_EMPTY(__bp)					\
    227 	(PSLIST_READER_FIRST(&(__bp)->bif_dlist_head, struct bpf_d,	\
    228 	    bd_bif_dlist_entry) == NULL)
    229 #define	BPFIF_DLIST_WRITER_EMPTY(__bp)					\
    230 	(PSLIST_WRITER_FIRST(&(__bp)->bif_dlist_head, struct bpf_d,	\
    231 	    bd_bif_dlist_entry) == NULL)
    232 #define BPFIF_DLIST_ENTRY_DESTROY(__d)					\
    233 	PSLIST_ENTRY_DESTROY((__d), bd_bif_dlist_entry)
    234 
    235 static int	bpf_allocbufs(struct bpf_d *);
    236 static u_int	bpf_xfilter(struct bpf_filter **, void *, u_int, u_int);
    237 static void	bpf_deliver(struct bpf_if *,
    238 		    void *(*cpfn)(void *, const void *, size_t),
    239 		    void *, u_int, u_int, const u_int);
    240 static void	bpf_freed(struct bpf_d *);
    241 static void	bpf_free_filter(struct bpf_filter *);
    242 static void	bpf_ifname(struct ifnet *, struct ifreq *);
    243 static void	*bpf_mcpy(void *, const void *, size_t);
    244 static int	bpf_movein(struct ifnet *, struct uio *, int, uint64_t,
    245 		    struct mbuf **, struct sockaddr *,
    246 		    struct bpf_filter **);
    247 static void	bpf_attachd(struct bpf_d *, struct bpf_if *);
    248 static void	bpf_detachd(struct bpf_d *);
    249 static int	bpf_setif(struct bpf_d *, struct ifreq *);
    250 static int	bpf_setf(struct bpf_d *, struct bpf_program *, u_long);
    251 static void	bpf_timed_out(void *);
    252 static inline void
    253 		bpf_wakeup(struct bpf_d *);
    254 static int	bpf_hdrlen(struct bpf_d *);
    255 static void	catchpacket(struct bpf_d *, u_char *, u_int, u_int,
    256 		    void *(*)(void *, const void *, size_t),
    257 		    struct timespec *);
    258 static void	reset_d(struct bpf_d *);
    259 static int	bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
    260 static int	bpf_setdlt(struct bpf_d *, u_int);
    261 
    262 static int	bpf_read(struct file *, off_t *, struct uio *, kauth_cred_t,
    263 		    int);
    264 static int	bpf_write(struct file *, off_t *, struct uio *, kauth_cred_t,
    265 		    int);
    266 static int	bpf_ioctl(struct file *, u_long, void *);
    267 static int	bpf_poll(struct file *, int);
    268 static int	bpf_stat(struct file *, struct stat *);
    269 static int	bpf_close(struct file *);
    270 static int	bpf_kqfilter(struct file *, struct knote *);
    271 static void	bpf_softintr(void *);
    272 
    273 static const struct fileops bpf_fileops = {
    274 	.fo_name = "bpf",
    275 	.fo_read = bpf_read,
    276 	.fo_write = bpf_write,
    277 	.fo_ioctl = bpf_ioctl,
    278 	.fo_fcntl = fnullop_fcntl,
    279 	.fo_poll = bpf_poll,
    280 	.fo_stat = bpf_stat,
    281 	.fo_close = bpf_close,
    282 	.fo_kqfilter = bpf_kqfilter,
    283 	.fo_restart = fnullop_restart,
    284 };
    285 
    286 dev_type_open(bpfopen);
    287 
    288 const struct cdevsw bpf_cdevsw = {
    289 	.d_open = bpfopen,
    290 	.d_close = noclose,
    291 	.d_read = noread,
    292 	.d_write = nowrite,
    293 	.d_ioctl = noioctl,
    294 	.d_stop = nostop,
    295 	.d_tty = notty,
    296 	.d_poll = nopoll,
    297 	.d_mmap = nommap,
    298 	.d_kqfilter = nokqfilter,
    299 	.d_discard = nodiscard,
    300 	.d_flag = D_OTHER | D_MPSAFE
    301 };
    302 
    303 bpfjit_func_t
    304 bpf_jit_generate(bpf_ctx_t *bc, void *code, size_t size)
    305 {
    306 	struct bpfjit_ops *ops = &bpfjit_module_ops;
    307 	bpfjit_func_t (*generate_code)(const bpf_ctx_t *,
    308 	    const struct bpf_insn *, size_t);
    309 
    310 	generate_code = atomic_load_acquire(&ops->bj_generate_code);
    311 	if (generate_code != NULL) {
    312 		return generate_code(bc, code, size);
    313 	}
    314 	return NULL;
    315 }
    316 
    317 void
    318 bpf_jit_freecode(bpfjit_func_t jcode)
    319 {
    320 	KASSERT(bpfjit_module_ops.bj_free_code != NULL);
    321 	bpfjit_module_ops.bj_free_code(jcode);
    322 }
    323 
    324 static int
    325 bpf_movein(struct ifnet *ifp, struct uio *uio, int linktype, uint64_t mtu,
    326     struct mbuf **mp, struct sockaddr *sockp, struct bpf_filter **wfilter)
    327 {
    328 	struct mbuf *m, *m0, *n;
    329 	int error;
    330 	size_t len;
    331 	size_t hlen;
    332 	size_t align;
    333 	u_int slen;
    334 
    335 	/*
    336 	 * Build a sockaddr based on the data link layer type.
    337 	 * We do this at this level because the ethernet header
    338 	 * is copied directly into the data field of the sockaddr.
    339 	 * In the case of SLIP, there is no header and the packet
    340 	 * is forwarded as is.
    341 	 * Also, we are careful to leave room at the front of the mbuf
    342 	 * for the link level header.
    343 	 */
    344 	switch (linktype) {
    345 
    346 	case DLT_SLIP:
    347 		sockp->sa_family = AF_INET;
    348 		hlen = 0;
    349 		align = 0;
    350 		break;
    351 
    352 	case DLT_PPP:
    353 		sockp->sa_family = AF_UNSPEC;
    354 		hlen = 0;
    355 		align = 0;
    356 		break;
    357 
    358 	case DLT_EN10MB:
    359 		sockp->sa_family = AF_UNSPEC;
    360 		/* XXX Would MAXLINKHDR be better? */
    361  		/* 6(dst)+6(src)+2(type) */
    362 		hlen = sizeof(struct ether_header);
    363 		align = 2;
    364 		break;
    365 
    366 	case DLT_ARCNET:
    367 		sockp->sa_family = AF_UNSPEC;
    368 		hlen = ARC_HDRLEN;
    369 		align = 5;
    370 		break;
    371 
    372 	case DLT_FDDI:
    373 		sockp->sa_family = AF_LINK;
    374 		/* XXX 4(FORMAC)+6(dst)+6(src) */
    375 		hlen = 16;
    376 		align = 0;
    377 		break;
    378 
    379 	case DLT_ECONET:
    380 		sockp->sa_family = AF_UNSPEC;
    381 		hlen = 6;
    382 		align = 2;
    383 		break;
    384 
    385 	case DLT_NULL:
    386 		sockp->sa_family = AF_UNSPEC;
    387 		if (ifp->if_type == IFT_LOOP) {
    388 			/* Set here to apply the following validations */
    389 			hlen = sizeof(uint32_t);
    390 		} else
    391 			hlen = 0;
    392 		align = 0;
    393 		break;
    394 
    395 	default:
    396 		return (EIO);
    397 	}
    398 
    399 	len = uio->uio_resid;
    400 	/*
    401 	 * If there aren't enough bytes for a link level header or the
    402 	 * packet length exceeds the interface mtu, return an error.
    403 	 */
    404 	if (len - hlen > mtu)
    405 		return (EMSGSIZE);
    406 
    407 	m0 = m = m_gethdr(M_WAIT, MT_DATA);
    408 	m_reset_rcvif(m);
    409 	m->m_pkthdr.len = (int)(len - hlen);
    410 	if (len + align > MHLEN) {
    411 		m_clget(m, M_WAIT);
    412 		if ((m->m_flags & M_EXT) == 0) {
    413 			error = ENOBUFS;
    414 			goto bad;
    415 		}
    416 	}
    417 
    418 	/* Ensure the data is properly aligned */
    419 	if (align > 0)
    420 		m->m_data += align;
    421 
    422 	for (;;) {
    423 		len = M_TRAILINGSPACE(m);
    424 		if (len > uio->uio_resid)
    425 			len = uio->uio_resid;
    426 		error = uiomove(mtod(m, void *), len, uio);
    427 		if (error)
    428 			goto bad;
    429 		m->m_len = len;
    430 
    431 		if (uio->uio_resid == 0)
    432 			break;
    433 
    434 		n = m_get(M_WAIT, MT_DATA);
    435 		m_clget(n, M_WAIT);	/* if fails, there is no problem */
    436 		m->m_next = n;
    437 		m = n;
    438 	}
    439 
    440 	slen = bpf_xfilter(wfilter, mtod(m, u_char *), len, len);
    441 	if (slen == 0) {
    442 		error = EPERM;
    443 		goto bad;
    444 	}
    445 
    446 	if (hlen != 0) {
    447 		if (linktype == DLT_NULL && ifp->if_type == IFT_LOOP) {
    448 			uint32_t af;
    449 			/* the link header indicates the address family */
    450 			memcpy(&af, mtod(m0, void *), sizeof(af));
    451 			sockp->sa_family = af;
    452 		} else {
    453 			/* move link level header in the top of mbuf to sa_data */
    454 			memcpy(sockp->sa_data, mtod(m0, void *), hlen);
    455 		}
    456 		m0->m_data += hlen;
    457 		m0->m_len -= hlen;
    458 	}
    459 
    460 	m_claimm(m, ifp->if_mowner);
    461 
    462 	*mp = m0;
    463 	return (0);
    464 
    465 bad:
    466 	m_freem(m0);
    467 	return (error);
    468 }
    469 
    470 /*
    471  * Attach file to the bpf interface, i.e. make d listen on bp.
    472  */
    473 static void
    474 bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
    475 {
    476 	struct bpf_event_tracker *t;
    477 
    478 	KASSERT(mutex_owned(&bpf_mtx));
    479 	KASSERT(mutex_owned(d->bd_mtx));
    480 	/*
    481 	 * Point d at bp, and add d to the interface's list of listeners.
    482 	 * Finally, point the driver's bpf cookie at the interface so
    483 	 * it will divert packets to bpf.
    484 	 */
    485 	d->bd_bif = bp;
    486 	BPFIF_DLIST_WRITER_INSERT_HEAD(bp, d);
    487 
    488 	*bp->bif_driverp = bp;
    489 
    490 	SLIST_FOREACH(t, &bp->bif_trackers, bet_entries) {
    491 		t->bet_notify(bp, bp->bif_ifp, bp->bif_dlt,
    492 		    BPF_TRACK_EVENT_ATTACH);
    493 	}
    494 }
    495 
    496 /*
    497  * Detach a file from its interface.
    498  */
    499 static void
    500 bpf_detachd(struct bpf_d *d)
    501 {
    502 	struct bpf_if *bp;
    503 	struct bpf_event_tracker *t;
    504 
    505 	KASSERT(mutex_owned(&bpf_mtx));
    506 	KASSERT(mutex_owned(d->bd_mtx));
    507 
    508 	bp = d->bd_bif;
    509 	/*
    510 	 * Check if this descriptor had requested promiscuous mode.
    511 	 * If so, turn it off.
    512 	 */
    513 	if (d->bd_promisc) {
    514 		int error __diagused;
    515 
    516 		d->bd_promisc = 0;
    517 		/*
    518 		 * Take device out of promiscuous mode.  Since we were
    519 		 * able to enter promiscuous mode, we should be able
    520 		 * to turn it off.  But we can get an error if
    521 		 * the interface was configured down, so only panic
    522 		 * if we don't get an unexpected error.
    523 		 */
    524 		KERNEL_LOCK_UNLESS_NET_MPSAFE();
    525   		error = ifpromisc(bp->bif_ifp, 0);
    526 		KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
    527 #ifdef DIAGNOSTIC
    528 		if (error)
    529 			printf("%s: ifpromisc failed: %d", __func__, error);
    530 #endif
    531 	}
    532 
    533 	/* Remove d from the interface's descriptor list. */
    534 	BPFIF_DLIST_WRITER_REMOVE(d);
    535 
    536 	pserialize_perform(bpf_psz);
    537 
    538 	if (BPFIF_DLIST_WRITER_EMPTY(bp)) {
    539 		/*
    540 		 * Let the driver know that there are no more listeners.
    541 		 */
    542 		*d->bd_bif->bif_driverp = NULL;
    543 	}
    544 
    545 	d->bd_bif = NULL;
    546 
    547 	SLIST_FOREACH(t, &bp->bif_trackers, bet_entries) {
    548 		t->bet_notify(bp, bp->bif_ifp, bp->bif_dlt,
    549 		    BPF_TRACK_EVENT_DETACH);
    550 	}
    551 }
    552 
    553 static void
    554 bpf_init(void)
    555 {
    556 
    557 	mutex_init(&bpf_mtx, MUTEX_DEFAULT, IPL_NONE);
    558 	bpf_psz = pserialize_create();
    559 	bpf_psref_class = psref_class_create("bpf", IPL_SOFTNET);
    560 
    561 	PSLIST_INIT(&bpf_iflist);
    562 	PSLIST_INIT(&bpf_dlist);
    563 
    564 	bpf_gstats_percpu = percpu_alloc(sizeof(struct bpf_stat));
    565 
    566 	return;
    567 }
    568 
    569 /*
    570  * bpfilterattach() is called at boot time.  We don't need to do anything
    571  * here, since any initialization will happen as part of module init code.
    572  */
    573 /* ARGSUSED */
    574 void
    575 bpfilterattach(int n)
    576 {
    577 
    578 }
    579 
    580 /*
    581  * Open ethernet device. Clones.
    582  */
    583 /* ARGSUSED */
    584 int
    585 bpfopen(dev_t dev, int flag, int mode, struct lwp *l)
    586 {
    587 	struct bpf_d *d;
    588 	struct file *fp;
    589 	int error, fd;
    590 
    591 	/* falloc() will fill in the descriptor for us. */
    592 	if ((error = fd_allocfile(&fp, &fd)) != 0)
    593 		return error;
    594 
    595 	d = kmem_zalloc(sizeof(*d), KM_SLEEP);
    596 	d->bd_bufsize = bpf_bufsize;
    597 	d->bd_direction = BPF_D_INOUT;
    598 	d->bd_feedback = 0;
    599 	d->bd_pid = l->l_proc->p_pid;
    600 #ifdef _LP64
    601 	if (curproc->p_flag & PK_32)
    602 		d->bd_compat32 = 1;
    603 #endif
    604 	getnanotime(&d->bd_btime);
    605 	d->bd_atime = d->bd_mtime = d->bd_btime;
    606 	callout_init(&d->bd_callout, CALLOUT_MPSAFE);
    607 	selinit(&d->bd_sel);
    608 	d->bd_sih = softint_establish(SOFTINT_CLOCK, bpf_softintr, d);
    609 	d->bd_jitcode = NULL;
    610 	d->bd_rfilter = NULL;
    611 	d->bd_wfilter = NULL;
    612 	d->bd_locked = 0;
    613 	BPF_DLIST_ENTRY_INIT(d);
    614 	BPFIF_DLIST_ENTRY_INIT(d);
    615 	d->bd_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTNET);
    616 	d->bd_buf_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NET);
    617 	cv_init(&d->bd_cv, "bpf");
    618 
    619 	mutex_enter(&bpf_mtx);
    620 	BPF_DLIST_WRITER_INSERT_HEAD(d);
    621 	mutex_exit(&bpf_mtx);
    622 
    623 	return fd_clone(fp, fd, flag, &bpf_fileops, d);
    624 }
    625 
    626 /*
    627  * Close the descriptor by detaching it from its interface,
    628  * deallocating its buffers, and marking it free.
    629  */
    630 /* ARGSUSED */
    631 static int
    632 bpf_close(struct file *fp)
    633 {
    634 	struct bpf_d *d;
    635 
    636 	mutex_enter(&bpf_mtx);
    637 
    638 	if ((d = fp->f_bpf) == NULL) {
    639 		mutex_exit(&bpf_mtx);
    640 		return 0;
    641 	}
    642 
    643 	/*
    644 	 * Refresh the PID associated with this bpf file.
    645 	 */
    646 	d->bd_pid = curproc->p_pid;
    647 
    648 	mutex_enter(d->bd_buf_mtx);
    649 	if (d->bd_state == BPF_WAITING)
    650 		callout_halt(&d->bd_callout, d->bd_buf_mtx);
    651 	d->bd_state = BPF_IDLE;
    652 	mutex_exit(d->bd_buf_mtx);
    653 	mutex_enter(d->bd_mtx);
    654 	if (d->bd_bif)
    655 		bpf_detachd(d);
    656 	mutex_exit(d->bd_mtx);
    657 
    658 	BPF_DLIST_WRITER_REMOVE(d);
    659 
    660 	pserialize_perform(bpf_psz);
    661 	mutex_exit(&bpf_mtx);
    662 
    663 	BPFIF_DLIST_ENTRY_DESTROY(d);
    664 	BPF_DLIST_ENTRY_DESTROY(d);
    665 	fp->f_bpf = NULL;
    666 	bpf_freed(d);
    667 	callout_destroy(&d->bd_callout);
    668 	seldestroy(&d->bd_sel);
    669 	softint_disestablish(d->bd_sih);
    670 	mutex_obj_free(d->bd_mtx);
    671 	mutex_obj_free(d->bd_buf_mtx);
    672 	cv_destroy(&d->bd_cv);
    673 
    674 	kmem_free(d, sizeof(*d));
    675 
    676 	return (0);
    677 }
    678 
    679 /*
    680  * Rotate the packet buffers in descriptor d.  Move the store buffer
    681  * into the hold slot, and the free buffer into the store slot.
    682  * Zero the length of the new store buffer.
    683  */
    684 #define ROTATE_BUFFERS(d) \
    685 	(d)->bd_hbuf = (d)->bd_sbuf; \
    686 	(d)->bd_hlen = (d)->bd_slen; \
    687 	(d)->bd_sbuf = (d)->bd_fbuf; \
    688 	(d)->bd_slen = 0; \
    689 	(d)->bd_fbuf = NULL;
    690 /*
    691  *  bpfread - read next chunk of packets from buffers
    692  */
    693 static int
    694 bpf_read(struct file *fp, off_t *offp, struct uio *uio,
    695     kauth_cred_t cred, int flags)
    696 {
    697 	struct bpf_d *d = fp->f_bpf;
    698 	int timed_out;
    699 	int error;
    700 
    701 	/*
    702 	 * Refresh the PID associated with this bpf file.
    703 	 */
    704 	d->bd_pid = curproc->p_pid;
    705 
    706 	getnanotime(&d->bd_atime);
    707 	/*
    708 	 * Restrict application to use a buffer the same size as
    709 	 * the kernel buffers.
    710 	 */
    711 	if (uio->uio_resid != d->bd_bufsize)
    712 		return (EINVAL);
    713 
    714 	mutex_enter(d->bd_buf_mtx);
    715 	if (d->bd_state == BPF_WAITING)
    716 		callout_halt(&d->bd_callout, d->bd_buf_mtx);
    717 	timed_out = (d->bd_state == BPF_TIMED_OUT);
    718 	d->bd_state = BPF_IDLE;
    719 	mutex_exit(d->bd_buf_mtx);
    720 	/*
    721 	 * If the hold buffer is empty, then do a timed sleep, which
    722 	 * ends when the timeout expires or when enough packets
    723 	 * have arrived to fill the store buffer.
    724 	 */
    725 	mutex_enter(d->bd_buf_mtx);
    726 	while (d->bd_hbuf == NULL) {
    727 		if (fp->f_flag & FNONBLOCK) {
    728 			if (d->bd_slen == 0) {
    729 				error = EWOULDBLOCK;
    730 				goto out;
    731 			}
    732 			ROTATE_BUFFERS(d);
    733 			break;
    734 		}
    735 
    736 		if ((d->bd_immediate || timed_out) && d->bd_slen != 0) {
    737 			/*
    738 			 * A packet(s) either arrived since the previous
    739 			 * read or arrived while we were asleep.
    740 			 * Rotate the buffers and return what's here.
    741 			 */
    742 			ROTATE_BUFFERS(d);
    743 			break;
    744 		}
    745 
    746 		error = cv_timedwait_sig(&d->bd_cv, d->bd_buf_mtx, d->bd_rtout);
    747 
    748 		if (error == EINTR || error == ERESTART)
    749 			goto out;
    750 
    751 		if (error == EWOULDBLOCK) {
    752 			/*
    753 			 * On a timeout, return what's in the buffer,
    754 			 * which may be nothing.  If there is something
    755 			 * in the store buffer, we can rotate the buffers.
    756 			 */
    757 			if (d->bd_hbuf)
    758 				/*
    759 				 * We filled up the buffer in between
    760 				 * getting the timeout and arriving
    761 				 * here, so we don't need to rotate.
    762 				 */
    763 				break;
    764 
    765 			if (d->bd_slen == 0) {
    766 				error = 0;
    767 				goto out;
    768 			}
    769 			ROTATE_BUFFERS(d);
    770 			break;
    771 		}
    772 		if (error != 0)
    773 			goto out;
    774 	}
    775 	/*
    776 	 * At this point, we know we have something in the hold slot.
    777 	 */
    778 	mutex_exit(d->bd_buf_mtx);
    779 
    780 	/*
    781 	 * Move data from hold buffer into user space.
    782 	 * We know the entire buffer is transferred since
    783 	 * we checked above that the read buffer is bpf_bufsize bytes.
    784 	 */
    785 	error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
    786 
    787 	mutex_enter(d->bd_buf_mtx);
    788 	d->bd_fbuf = d->bd_hbuf;
    789 	d->bd_hbuf = NULL;
    790 	d->bd_hlen = 0;
    791 out:
    792 	mutex_exit(d->bd_buf_mtx);
    793 	return (error);
    794 }
    795 
    796 /*
    797  * If there are processes sleeping on this descriptor, wake them up.
    798  */
    799 static inline void
    800 bpf_wakeup(struct bpf_d *d)
    801 {
    802 
    803 	KASSERT(mutex_owned(d->bd_buf_mtx));
    804 
    805 	cv_broadcast(&d->bd_cv);
    806 
    807 	if (d->bd_async)
    808 		softint_schedule(d->bd_sih);
    809 	selnotify(&d->bd_sel, 0, NOTE_SUBMIT);
    810 }
    811 
    812 static void
    813 bpf_softintr(void *cookie)
    814 {
    815 	struct bpf_d *d;
    816 
    817 	d = cookie;
    818 	if (d->bd_async)
    819 		fownsignal(d->bd_pgid, SIGIO, 0, 0, NULL);
    820 }
    821 
    822 static void
    823 bpf_timed_out(void *arg)
    824 {
    825 	struct bpf_d *d = arg;
    826 
    827 	mutex_enter(d->bd_buf_mtx);
    828 	if (d->bd_state == BPF_WAITING) {
    829 		d->bd_state = BPF_TIMED_OUT;
    830 		if (d->bd_slen != 0)
    831 			bpf_wakeup(d);
    832 	}
    833 	mutex_exit(d->bd_buf_mtx);
    834 }
    835 
    836 static int
    837 bpf_write(struct file *fp, off_t *offp, struct uio *uio,
    838     kauth_cred_t cred, int flags)
    839 {
    840 	struct bpf_d *d = fp->f_bpf;
    841 	struct bpf_if *bp;
    842 	struct ifnet *ifp;
    843 	struct mbuf *m, *mc;
    844 	int error;
    845 	static struct sockaddr_storage dst;
    846 	struct psref psref;
    847 	int bound;
    848 
    849 	/*
    850 	 * Refresh the PID associated with this bpf file.
    851 	 */
    852 	d->bd_pid = curproc->p_pid;
    853 
    854 	m = NULL;	/* XXX gcc */
    855 
    856 	bound = curlwp_bind();
    857 	mutex_enter(d->bd_mtx);
    858 	bp = d->bd_bif;
    859 	if (bp == NULL) {
    860 		mutex_exit(d->bd_mtx);
    861 		error = ENXIO;
    862 		goto out_bindx;
    863 	}
    864 	bpf_if_acquire(bp, &psref);
    865 	mutex_exit(d->bd_mtx);
    866 
    867 	getnanotime(&d->bd_mtime);
    868 
    869 	ifp = bp->bif_ifp;
    870 	if (if_is_deactivated(ifp)) {
    871 		error = ENXIO;
    872 		goto out;
    873 	}
    874 
    875 	if (uio->uio_resid == 0) {
    876 		error = 0;
    877 		goto out;
    878 	}
    879 
    880 	error = bpf_movein(ifp, uio, (int)bp->bif_dlt, ifp->if_mtu, &m,
    881 	    (struct sockaddr *) &dst, &d->bd_wfilter);
    882 	if (error)
    883 		goto out;
    884 
    885 	if (m->m_pkthdr.len > ifp->if_mtu) {
    886 		m_freem(m);
    887 		error = EMSGSIZE;
    888 		goto out;
    889 	}
    890 
    891 	/*
    892 	 * If writing to a loopback interface, the address family has
    893 	 * already been specially computed in bpf_movein(), so don't
    894 	 * clobber it, or the loopback will reject it in looutput().
    895 	 */
    896 	if (d->bd_hdrcmplt && ifp->if_type != IFT_LOOP)
    897 		dst.ss_family = pseudo_AF_HDRCMPLT;
    898 
    899 	if (d->bd_feedback) {
    900 		mc = m_dup(m, 0, M_COPYALL, M_NOWAIT);
    901 		if (mc != NULL)
    902 			m_set_rcvif(mc, ifp);
    903 		/* Set M_PROMISC for outgoing packets to be discarded. */
    904 		if (1 /*d->bd_direction == BPF_D_INOUT*/)
    905 			m->m_flags |= M_PROMISC;
    906 	} else
    907 		mc = NULL;
    908 
    909 	error = if_output_lock(ifp, ifp, m, (struct sockaddr *) &dst, NULL);
    910 
    911 	if (mc != NULL) {
    912 		if (error == 0) {
    913 			int s = splsoftnet();
    914 			KERNEL_LOCK_UNLESS_IFP_MPSAFE(ifp);
    915 			ifp->_if_input(ifp, mc);
    916 			KERNEL_UNLOCK_UNLESS_IFP_MPSAFE(ifp);
    917 			splx(s);
    918 		} else
    919 			m_freem(mc);
    920 	}
    921 	/*
    922 	 * The driver frees the mbuf.
    923 	 */
    924 out:
    925 	bpf_if_release(bp, &psref);
    926 out_bindx:
    927 	curlwp_bindx(bound);
    928 	return error;
    929 }
    930 
    931 /*
    932  * Reset a descriptor by flushing its packet buffer and clearing the
    933  * receive and drop counts.
    934  */
    935 static void
    936 reset_d(struct bpf_d *d)
    937 {
    938 
    939 	KASSERT(mutex_owned(d->bd_mtx));
    940 
    941 	mutex_enter(d->bd_buf_mtx);
    942 	if (d->bd_hbuf) {
    943 		/* Free the hold buffer. */
    944 		d->bd_fbuf = d->bd_hbuf;
    945 		d->bd_hbuf = NULL;
    946 	}
    947 	d->bd_slen = 0;
    948 	d->bd_hlen = 0;
    949 	d->bd_rcount = 0;
    950 	d->bd_dcount = 0;
    951 	d->bd_ccount = 0;
    952 	mutex_exit(d->bd_buf_mtx);
    953 }
    954 
    955 /*
    956  *  FIONREAD		Check for read packet available.
    957  *  BIOCGBLEN		Get buffer len [for read()].
    958  *  BIOCSETF		Set ethernet read filter.
    959  *  BIOCFLUSH		Flush read packet buffer.
    960  *  BIOCPROMISC		Put interface into promiscuous mode.
    961  *  BIOCGDLT		Get link layer type.
    962  *  BIOCGETIF		Get interface name.
    963  *  BIOCSETIF		Set interface.
    964  *  BIOCSRTIMEOUT	Set read timeout.
    965  *  BIOCGRTIMEOUT	Get read timeout.
    966  *  BIOCGSTATS		Get packet stats.
    967  *  BIOCIMMEDIATE	Set immediate mode.
    968  *  BIOCVERSION		Get filter language version.
    969  *  BIOCGHDRCMPLT	Get "header already complete" flag.
    970  *  BIOCSHDRCMPLT	Set "header already complete" flag.
    971  *  BIOCSFEEDBACK	Set packet feedback mode.
    972  *  BIOCGFEEDBACK	Get packet feedback mode.
    973  *  BIOCGDIRECTION	Get packet direction flag
    974  *  BIOCSDIRECTION	Set packet direction flag
    975  */
    976 /* ARGSUSED */
    977 static int
    978 bpf_ioctl(struct file *fp, u_long cmd, void *addr)
    979 {
    980 	struct bpf_d *d = fp->f_bpf;
    981 	int error = 0;
    982 
    983 	/*
    984 	 * Refresh the PID associated with this bpf file.
    985 	 */
    986 	d->bd_pid = curproc->p_pid;
    987 #ifdef _LP64
    988 	if (curproc->p_flag & PK_32)
    989 		d->bd_compat32 = 1;
    990 	else
    991 		d->bd_compat32 = 0;
    992 #endif
    993 
    994 	mutex_enter(d->bd_buf_mtx);
    995 	if (d->bd_state == BPF_WAITING)
    996 		callout_halt(&d->bd_callout, d->bd_buf_mtx);
    997 	d->bd_state = BPF_IDLE;
    998 	mutex_exit(d->bd_buf_mtx);
    999 
   1000 	if (d->bd_locked) {
   1001 		switch (cmd) {
   1002 		case BIOCGBLEN:		/* FALLTHROUGH */
   1003 		case BIOCFLUSH:		/* FALLTHROUGH */
   1004 		case BIOCGDLT:		/* FALLTHROUGH */
   1005 		case BIOCGDLTLIST:	/* FALLTHROUGH */
   1006 		case BIOCGETIF:		/* FALLTHROUGH */
   1007 		case BIOCGRTIMEOUT:	/* FALLTHROUGH */
   1008 		case BIOCGSTATS:	/* FALLTHROUGH */
   1009 		case BIOCVERSION:	/* FALLTHROUGH */
   1010 		case BIOCGHDRCMPLT:	/* FALLTHROUGH */
   1011 		case FIONREAD:		/* FALLTHROUGH */
   1012 		case BIOCLOCK:		/* FALLTHROUGH */
   1013 		case BIOCSRTIMEOUT:	/* FALLTHROUGH */
   1014 		case BIOCIMMEDIATE:	/* FALLTHROUGH */
   1015 		case TIOCGPGRP:
   1016 			break;
   1017 		default:
   1018 			return EPERM;
   1019 		}
   1020 	}
   1021 
   1022 	switch (cmd) {
   1023 
   1024 	default:
   1025 		error = EINVAL;
   1026 		break;
   1027 
   1028 	/*
   1029 	 * Check for read packet available.
   1030 	 */
   1031 	case FIONREAD: {
   1032 		int n;
   1033 
   1034 		mutex_enter(d->bd_buf_mtx);
   1035 		n = d->bd_slen;
   1036 		if (d->bd_hbuf)
   1037 			n += d->bd_hlen;
   1038 		mutex_exit(d->bd_buf_mtx);
   1039 
   1040 		*(int *)addr = n;
   1041 		break;
   1042 	}
   1043 
   1044 	/*
   1045 	 * Get buffer len [for read()].
   1046 	 */
   1047 	case BIOCGBLEN:
   1048 		*(u_int *)addr = d->bd_bufsize;
   1049 		break;
   1050 
   1051 	/*
   1052 	 * Set buffer length.
   1053 	 */
   1054 	case BIOCSBLEN:
   1055 		/*
   1056 		 * Forbid to change the buffer length if buffers are already
   1057 		 * allocated.
   1058 		 */
   1059 		mutex_enter(d->bd_mtx);
   1060 		mutex_enter(d->bd_buf_mtx);
   1061 		if (d->bd_bif != NULL || d->bd_sbuf != NULL)
   1062 			error = EINVAL;
   1063 		else {
   1064 			u_int size = *(u_int *)addr;
   1065 
   1066 			if (size > bpf_maxbufsize)
   1067 				*(u_int *)addr = size = bpf_maxbufsize;
   1068 			else if (size < BPF_MINBUFSIZE)
   1069 				*(u_int *)addr = size = BPF_MINBUFSIZE;
   1070 			d->bd_bufsize = size;
   1071 		}
   1072 		mutex_exit(d->bd_buf_mtx);
   1073 		mutex_exit(d->bd_mtx);
   1074 		break;
   1075 
   1076 	/*
   1077 	 * Set link layer read filter.
   1078 	 */
   1079 	case BIOCSETF:		/* FALLTHROUGH */
   1080 	case BIOCSETWF:
   1081 		error = bpf_setf(d, addr, cmd);
   1082 		break;
   1083 
   1084 	case BIOCLOCK:
   1085 		d->bd_locked = 1;
   1086 		break;
   1087 
   1088 	/*
   1089 	 * Flush read packet buffer.
   1090 	 */
   1091 	case BIOCFLUSH:
   1092 		mutex_enter(d->bd_mtx);
   1093 		reset_d(d);
   1094 		mutex_exit(d->bd_mtx);
   1095 		break;
   1096 
   1097 	/*
   1098 	 * Put interface into promiscuous mode.
   1099 	 */
   1100 	case BIOCPROMISC:
   1101 		mutex_enter(d->bd_mtx);
   1102 		if (d->bd_bif == NULL) {
   1103 			mutex_exit(d->bd_mtx);
   1104 			/*
   1105 			 * No interface attached yet.
   1106 			 */
   1107 			error = EINVAL;
   1108 			break;
   1109 		}
   1110 		if (d->bd_promisc == 0) {
   1111 			KERNEL_LOCK_UNLESS_NET_MPSAFE();
   1112 			error = ifpromisc(d->bd_bif->bif_ifp, 1);
   1113 			KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
   1114 			if (error == 0)
   1115 				d->bd_promisc = 1;
   1116 		}
   1117 		mutex_exit(d->bd_mtx);
   1118 		break;
   1119 
   1120 	/*
   1121 	 * Get device parameters.
   1122 	 */
   1123 	case BIOCGDLT:
   1124 		mutex_enter(d->bd_mtx);
   1125 		if (d->bd_bif == NULL)
   1126 			error = EINVAL;
   1127 		else
   1128 			*(u_int *)addr = d->bd_bif->bif_dlt;
   1129 		mutex_exit(d->bd_mtx);
   1130 		break;
   1131 
   1132 	/*
   1133 	 * Get a list of supported device parameters.
   1134 	 */
   1135 	case BIOCGDLTLIST:
   1136 		mutex_enter(d->bd_mtx);
   1137 		if (d->bd_bif == NULL)
   1138 			error = EINVAL;
   1139 		else
   1140 			error = bpf_getdltlist(d, addr);
   1141 		mutex_exit(d->bd_mtx);
   1142 		break;
   1143 
   1144 	/*
   1145 	 * Set device parameters.
   1146 	 */
   1147 	case BIOCSDLT:
   1148 		mutex_enter(&bpf_mtx);
   1149 		mutex_enter(d->bd_mtx);
   1150 		if (d->bd_bif == NULL)
   1151 			error = EINVAL;
   1152 		else
   1153 			error = bpf_setdlt(d, *(u_int *)addr);
   1154 		mutex_exit(d->bd_mtx);
   1155 		mutex_exit(&bpf_mtx);
   1156 		break;
   1157 
   1158 	/*
   1159 	 * Set interface name.
   1160 	 */
   1161 #ifdef OBIOCGETIF
   1162 	case OBIOCGETIF:
   1163 #endif
   1164 	case BIOCGETIF:
   1165 		mutex_enter(d->bd_mtx);
   1166 		if (d->bd_bif == NULL)
   1167 			error = EINVAL;
   1168 		else
   1169 			bpf_ifname(d->bd_bif->bif_ifp, addr);
   1170 		mutex_exit(d->bd_mtx);
   1171 		break;
   1172 
   1173 	/*
   1174 	 * Set interface.
   1175 	 */
   1176 #ifdef OBIOCSETIF
   1177 	case OBIOCSETIF:
   1178 #endif
   1179 	case BIOCSETIF:
   1180 		mutex_enter(&bpf_mtx);
   1181 		error = bpf_setif(d, addr);
   1182 		mutex_exit(&bpf_mtx);
   1183 		break;
   1184 
   1185 	/*
   1186 	 * Set read timeout.
   1187 	 */
   1188 	case BIOCSRTIMEOUT: {
   1189 		struct timeval *tv = addr;
   1190 
   1191 		/* Compute number of ticks. */
   1192 		if (tv->tv_sec < 0 ||
   1193 		    tv->tv_usec < 0 || tv->tv_usec >= 1000000) {
   1194 			error = EINVAL;
   1195 			break;
   1196 		} else if (tv->tv_sec > INT_MAX/hz - 1) {
   1197 			d->bd_rtout = INT_MAX;
   1198 		} else {
   1199 			d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick;
   1200 		}
   1201 		if ((d->bd_rtout == 0) && (tv->tv_usec != 0))
   1202 			d->bd_rtout = 1;
   1203 		break;
   1204 	}
   1205 
   1206 #ifdef BIOCGORTIMEOUT
   1207 	/*
   1208 	 * Get read timeout.
   1209 	 */
   1210 	case BIOCGORTIMEOUT: {
   1211 		struct timeval50 *tv = addr;
   1212 
   1213 		tv->tv_sec = d->bd_rtout / hz;
   1214 		tv->tv_usec = (d->bd_rtout % hz) * tick;
   1215 		break;
   1216 	}
   1217 #endif
   1218 
   1219 #ifdef BIOCSORTIMEOUT
   1220 	/*
   1221 	 * Set read timeout.
   1222 	 */
   1223 	case BIOCSORTIMEOUT: {
   1224 		struct timeval50 *tv = addr;
   1225 
   1226 		/* Compute number of ticks. */
   1227 		if (tv->tv_sec < 0 ||
   1228 		    tv->tv_usec < 0 || tv->tv_usec >= 1000000) {
   1229 			error = EINVAL;
   1230 			break;
   1231 		} else if (tv->tv_sec > INT_MAX/hz - 1) {
   1232 			d->bd_rtout = INT_MAX;
   1233 		} else {
   1234 			d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick;
   1235 		}
   1236 		if ((d->bd_rtout == 0) && (tv->tv_usec != 0))
   1237 			d->bd_rtout = 1;
   1238 		break;
   1239 	}
   1240 #endif
   1241 
   1242 	/*
   1243 	 * Get read timeout.
   1244 	 */
   1245 	case BIOCGRTIMEOUT: {
   1246 		struct timeval *tv = addr;
   1247 
   1248 		tv->tv_sec = d->bd_rtout / hz;
   1249 		tv->tv_usec = (d->bd_rtout % hz) * tick;
   1250 		break;
   1251 	}
   1252 	/*
   1253 	 * Get packet stats.
   1254 	 */
   1255 	case BIOCGSTATS: {
   1256 		struct bpf_stat *bs = addr;
   1257 
   1258 		bs->bs_recv = d->bd_rcount;
   1259 		bs->bs_drop = d->bd_dcount;
   1260 		bs->bs_capt = d->bd_ccount;
   1261 		break;
   1262 	}
   1263 
   1264 	case BIOCGSTATS_30: {
   1265 		struct bpf_stat30 *bs = addr;
   1266 
   1267 		bs->bs_recv = d->bd_rcount;
   1268 		bs->bs_drop = d->bd_dcount;
   1269 		break;
   1270 	}
   1271 
   1272 	/*
   1273 	 * Set immediate mode.
   1274 	 */
   1275 	case BIOCIMMEDIATE:
   1276 		d->bd_immediate = *(u_int *)addr;
   1277 		break;
   1278 
   1279 	case BIOCVERSION: {
   1280 		struct bpf_version *bv = addr;
   1281 
   1282 		bv->bv_major = BPF_MAJOR_VERSION;
   1283 		bv->bv_minor = BPF_MINOR_VERSION;
   1284 		break;
   1285 	}
   1286 
   1287 	case BIOCGHDRCMPLT:	/* get "header already complete" flag */
   1288 		*(u_int *)addr = d->bd_hdrcmplt;
   1289 		break;
   1290 
   1291 	case BIOCSHDRCMPLT:	/* set "header already complete" flag */
   1292 		d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
   1293 		break;
   1294 
   1295 	/*
   1296 	 * Get packet direction flag
   1297 	 */
   1298 	case BIOCGDIRECTION:
   1299 		*(u_int *)addr = d->bd_direction;
   1300 		break;
   1301 
   1302 	/*
   1303 	 * Set packet direction flag
   1304 	 */
   1305 	case BIOCSDIRECTION: {
   1306 		u_int	direction;
   1307 
   1308 		direction = *(u_int *)addr;
   1309 		switch (direction) {
   1310 		case BPF_D_IN:
   1311 		case BPF_D_INOUT:
   1312 		case BPF_D_OUT:
   1313 			d->bd_direction = direction;
   1314 			break;
   1315 		default:
   1316 			error = EINVAL;
   1317 		}
   1318 	}
   1319 	break;
   1320 
   1321 	/*
   1322 	 * Set "feed packets from bpf back to input" mode
   1323 	 */
   1324 	case BIOCSFEEDBACK:
   1325 		d->bd_feedback = *(u_int *)addr;
   1326 		break;
   1327 
   1328 	/*
   1329 	 * Get "feed packets from bpf back to input" mode
   1330 	 */
   1331 	case BIOCGFEEDBACK:
   1332 		*(u_int *)addr = d->bd_feedback;
   1333 		break;
   1334 
   1335 	case FIONBIO:		/* Non-blocking I/O */
   1336 		/*
   1337 		 * No need to do anything special as we use IO_NDELAY in
   1338 		 * bpfread() as an indication of whether or not to block
   1339 		 * the read.
   1340 		 */
   1341 		break;
   1342 
   1343 	case FIOASYNC:		/* Send signal on receive packets */
   1344 		mutex_enter(d->bd_mtx);
   1345 		d->bd_async = *(int *)addr;
   1346 		mutex_exit(d->bd_mtx);
   1347 		break;
   1348 
   1349 	case TIOCSPGRP:		/* Process or group to send signals to */
   1350 	case FIOSETOWN:
   1351 		error = fsetown(&d->bd_pgid, cmd, addr);
   1352 		break;
   1353 
   1354 	case TIOCGPGRP:
   1355 	case FIOGETOWN:
   1356 		error = fgetown(d->bd_pgid, cmd, addr);
   1357 		break;
   1358 	}
   1359 	return (error);
   1360 }
   1361 
   1362 /*
   1363  * Set d's packet filter program to fp.  If this file already has a filter,
   1364  * free it and replace it.  Returns EINVAL for bogus requests.
   1365  */
   1366 static int
   1367 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
   1368 {
   1369 	struct bpf_insn *fcode;
   1370 	bpfjit_func_t jcode;
   1371 	size_t flen, size = 0;
   1372 	struct bpf_filter *oldf, *newf, **storef;
   1373 
   1374 	jcode = NULL;
   1375 	flen = fp->bf_len;
   1376 
   1377 	if ((fp->bf_insns == NULL && flen) || flen > BPF_MAXINSNS) {
   1378 		return EINVAL;
   1379 	}
   1380 
   1381 	if (flen) {
   1382 		/*
   1383 		 * Allocate the buffer, copy the byte-code from
   1384 		 * userspace and validate it.
   1385 		 */
   1386 		size = flen * sizeof(*fp->bf_insns);
   1387 		fcode = kmem_alloc(size, KM_SLEEP);
   1388 		if (copyin(fp->bf_insns, fcode, size) != 0 ||
   1389 		    !bpf_validate(fcode, (int)flen)) {
   1390 			kmem_free(fcode, size);
   1391 			return EINVAL;
   1392 		}
   1393 		if (bpf_jit)
   1394 			jcode = bpf_jit_generate(NULL, fcode, flen);
   1395 	} else {
   1396 		fcode = NULL;
   1397 	}
   1398 
   1399 	newf = kmem_alloc(sizeof(*newf), KM_SLEEP);
   1400 	newf->bf_insn = fcode;
   1401 	newf->bf_size = size;
   1402 	newf->bf_jitcode = jcode;
   1403 	if (cmd == BIOCSETF)
   1404 		d->bd_jitcode = jcode; /* XXX just for kvm(3) users */
   1405 
   1406 	/* Need to hold bpf_mtx for pserialize_perform */
   1407 	mutex_enter(&bpf_mtx);
   1408 	mutex_enter(d->bd_mtx);
   1409 	if (cmd == BIOCSETWF) {
   1410 		oldf = d->bd_wfilter;
   1411 		storef = &d->bd_wfilter;
   1412 	} else {
   1413 		oldf = d->bd_rfilter;
   1414 		storef = &d->bd_rfilter;
   1415 	}
   1416 	atomic_store_release(storef, newf);
   1417 	reset_d(d);
   1418 	pserialize_perform(bpf_psz);
   1419 	mutex_exit(d->bd_mtx);
   1420 	mutex_exit(&bpf_mtx);
   1421 
   1422 	if (oldf != NULL)
   1423 		bpf_free_filter(oldf);
   1424 
   1425 	return 0;
   1426 }
   1427 
   1428 /*
   1429  * Detach a file from its current interface (if attached at all) and attach
   1430  * to the interface indicated by the name stored in ifr.
   1431  * Return an errno or 0.
   1432  */
   1433 static int
   1434 bpf_setif(struct bpf_d *d, struct ifreq *ifr)
   1435 {
   1436 	struct bpf_if *bp;
   1437 	char *cp;
   1438 	int unit_seen, i, error;
   1439 
   1440 	KASSERT(mutex_owned(&bpf_mtx));
   1441 	/*
   1442 	 * Make sure the provided name has a unit number, and default
   1443 	 * it to '0' if not specified.
   1444 	 * XXX This is ugly ... do this differently?
   1445 	 */
   1446 	unit_seen = 0;
   1447 	cp = ifr->ifr_name;
   1448 	cp[sizeof(ifr->ifr_name) - 1] = '\0';	/* sanity */
   1449 	while (*cp++)
   1450 		if (*cp >= '0' && *cp <= '9')
   1451 			unit_seen = 1;
   1452 	if (!unit_seen) {
   1453 		/* Make sure to leave room for the '\0'. */
   1454 		for (i = 0; i < (IFNAMSIZ - 1); ++i) {
   1455 			if ((ifr->ifr_name[i] >= 'a' &&
   1456 				ifr->ifr_name[i] <= 'z') ||
   1457 			    (ifr->ifr_name[i] >= 'A' &&
   1458 				ifr->ifr_name[i] <= 'Z'))
   1459 				continue;
   1460 			ifr->ifr_name[i] = '0';
   1461 		}
   1462 	}
   1463 
   1464 	/*
   1465 	 * Look through attached interfaces for the named one.
   1466 	 */
   1467 	BPF_IFLIST_WRITER_FOREACH(bp) {
   1468 		struct ifnet *ifp = bp->bif_ifp;
   1469 
   1470 		if (ifp == NULL ||
   1471 		    strcmp(ifp->if_xname, ifr->ifr_name) != 0)
   1472 			continue;
   1473 		/* skip additional entry */
   1474 		if (bp->bif_driverp != &ifp->if_bpf)
   1475 			continue;
   1476 		/*
   1477 		 * We found the requested interface.
   1478 		 * Allocate the packet buffers if we need to.
   1479 		 * If we're already attached to requested interface,
   1480 		 * just flush the buffer.
   1481 		 */
   1482 		/*
   1483 		 * bpf_allocbufs is called only here. bpf_mtx ensures that
   1484 		 * no race condition happen on d->bd_sbuf.
   1485 		 */
   1486 		if (d->bd_sbuf == NULL) {
   1487 			error = bpf_allocbufs(d);
   1488 			if (error != 0)
   1489 				return (error);
   1490 		}
   1491 		mutex_enter(d->bd_mtx);
   1492 		if (bp != d->bd_bif) {
   1493 			if (d->bd_bif) {
   1494 				/*
   1495 				 * Detach if attached to something else.
   1496 				 */
   1497 				bpf_detachd(d);
   1498 				BPFIF_DLIST_ENTRY_INIT(d);
   1499 			}
   1500 
   1501 			bpf_attachd(d, bp);
   1502 		}
   1503 		reset_d(d);
   1504 		mutex_exit(d->bd_mtx);
   1505 		return (0);
   1506 	}
   1507 	/* Not found. */
   1508 	return (ENXIO);
   1509 }
   1510 
   1511 /*
   1512  * Copy the interface name to the ifreq.
   1513  */
   1514 static void
   1515 bpf_ifname(struct ifnet *ifp, struct ifreq *ifr)
   1516 {
   1517 	memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
   1518 }
   1519 
   1520 static int
   1521 bpf_stat(struct file *fp, struct stat *st)
   1522 {
   1523 	struct bpf_d *d = fp->f_bpf;
   1524 
   1525 	(void)memset(st, 0, sizeof(*st));
   1526 	mutex_enter(d->bd_mtx);
   1527 	st->st_dev = makedev(cdevsw_lookup_major(&bpf_cdevsw), d->bd_pid);
   1528 	st->st_atimespec = d->bd_atime;
   1529 	st->st_mtimespec = d->bd_mtime;
   1530 	st->st_ctimespec = st->st_birthtimespec = d->bd_btime;
   1531 	st->st_uid = kauth_cred_geteuid(fp->f_cred);
   1532 	st->st_gid = kauth_cred_getegid(fp->f_cred);
   1533 	st->st_mode = S_IFCHR;
   1534 	mutex_exit(d->bd_mtx);
   1535 	return 0;
   1536 }
   1537 
   1538 /*
   1539  * Support for poll() system call
   1540  *
   1541  * Return true iff the specific operation will not block indefinitely - with
   1542  * the assumption that it is safe to positively acknowledge a request for the
   1543  * ability to write to the BPF device.
   1544  * Otherwise, return false but make a note that a selnotify() must be done.
   1545  */
   1546 static int
   1547 bpf_poll(struct file *fp, int events)
   1548 {
   1549 	struct bpf_d *d = fp->f_bpf;
   1550 	int revents;
   1551 
   1552 	/*
   1553 	 * Refresh the PID associated with this bpf file.
   1554 	 */
   1555 	mutex_enter(&bpf_mtx);
   1556 	d->bd_pid = curproc->p_pid;
   1557 
   1558 	revents = events & (POLLOUT | POLLWRNORM);
   1559 	if (events & (POLLIN | POLLRDNORM)) {
   1560 		/*
   1561 		 * An imitation of the FIONREAD ioctl code.
   1562 		 */
   1563 		mutex_enter(d->bd_mtx);
   1564 		mutex_enter(d->bd_buf_mtx);
   1565 		if (d->bd_hlen != 0 ||
   1566 		    ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
   1567 			d->bd_slen != 0)) {
   1568 			revents |= events & (POLLIN | POLLRDNORM);
   1569 		} else {
   1570 			selrecord(curlwp, &d->bd_sel);
   1571 			/* Start the read timeout if necessary */
   1572 			if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
   1573 				callout_reset(&d->bd_callout, d->bd_rtout,
   1574 				    bpf_timed_out, d);
   1575 				d->bd_state = BPF_WAITING;
   1576 			}
   1577 		}
   1578 		mutex_exit(d->bd_buf_mtx);
   1579 		mutex_exit(d->bd_mtx);
   1580 	}
   1581 
   1582 	mutex_exit(&bpf_mtx);
   1583 	return (revents);
   1584 }
   1585 
   1586 static void
   1587 filt_bpfrdetach(struct knote *kn)
   1588 {
   1589 	struct bpf_d *d = kn->kn_hook;
   1590 
   1591 	mutex_enter(d->bd_buf_mtx);
   1592 	selremove_knote(&d->bd_sel, kn);
   1593 	mutex_exit(d->bd_buf_mtx);
   1594 }
   1595 
   1596 static int
   1597 filt_bpfread(struct knote *kn, long hint)
   1598 {
   1599 	struct bpf_d *d = kn->kn_hook;
   1600 	int rv;
   1601 
   1602 	/*
   1603 	 * Refresh the PID associated with this bpf file.
   1604 	 */
   1605 	d->bd_pid = curproc->p_pid;
   1606 
   1607 	if (hint & NOTE_SUBMIT)
   1608 		KASSERT(mutex_owned(d->bd_buf_mtx));
   1609 	else
   1610 		mutex_enter(d->bd_buf_mtx);
   1611 	kn->kn_data = d->bd_hlen;
   1612 	if (d->bd_immediate)
   1613 		kn->kn_data += d->bd_slen;
   1614 	rv = (kn->kn_data > 0);
   1615 	if (hint & NOTE_SUBMIT)
   1616 		KASSERT(mutex_owned(d->bd_buf_mtx));
   1617 	else
   1618 		mutex_exit(d->bd_buf_mtx);
   1619 	return rv;
   1620 }
   1621 
   1622 static const struct filterops bpfread_filtops = {
   1623 	.f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
   1624 	.f_attach = NULL,
   1625 	.f_detach = filt_bpfrdetach,
   1626 	.f_event = filt_bpfread,
   1627 };
   1628 
   1629 static int
   1630 bpf_kqfilter(struct file *fp, struct knote *kn)
   1631 {
   1632 	struct bpf_d *d = fp->f_bpf;
   1633 
   1634 	switch (kn->kn_filter) {
   1635 	case EVFILT_READ:
   1636 		kn->kn_fop = &bpfread_filtops;
   1637 		break;
   1638 
   1639 	default:
   1640 		return (EINVAL);
   1641 	}
   1642 
   1643 	kn->kn_hook = d;
   1644 
   1645 	mutex_enter(d->bd_buf_mtx);
   1646 	selrecord_knote(&d->bd_sel, kn);
   1647 	mutex_exit(d->bd_buf_mtx);
   1648 
   1649 	return (0);
   1650 }
   1651 
   1652 /*
   1653  * Copy data from an mbuf chain into a buffer.  This code is derived
   1654  * from m_copydata in sys/uipc_mbuf.c.
   1655  */
   1656 static void *
   1657 bpf_mcpy(void *dst_arg, const void *src_arg, size_t len)
   1658 {
   1659 	const struct mbuf *m;
   1660 	u_int count;
   1661 	u_char *dst;
   1662 
   1663 	m = src_arg;
   1664 	dst = dst_arg;
   1665 	while (len > 0) {
   1666 		if (m == NULL)
   1667 			panic("bpf_mcpy");
   1668 		count = uimin(m->m_len, len);
   1669 		memcpy(dst, mtod(m, const void *), count);
   1670 		m = m->m_next;
   1671 		dst += count;
   1672 		len -= count;
   1673 	}
   1674 	return dst_arg;
   1675 }
   1676 
   1677 static inline u_int
   1678 bpf_xfilter(struct bpf_filter **filter, void *pkt, u_int pktlen, u_int buflen)
   1679 {
   1680 	struct bpf_filter *filt;
   1681 	uint32_t mem[BPF_MEMWORDS];
   1682 	bpf_args_t args = {
   1683 		.pkt = (const uint8_t *)pkt,
   1684 		.wirelen = pktlen,
   1685 		.buflen = buflen,
   1686 		.mem = mem,
   1687 		.arg = NULL
   1688 	};
   1689 	u_int slen;
   1690 
   1691 	filt = atomic_load_consume(filter);
   1692 	if (filt == NULL) /* No filter means accept all. */
   1693 		return (u_int)-1;
   1694 
   1695 	if (filt->bf_jitcode != NULL)
   1696 		slen = filt->bf_jitcode(NULL, &args);
   1697 	else
   1698 		slen = bpf_filter_ext(NULL, filt->bf_insn, &args);
   1699 	return slen;
   1700 }
   1701 
   1702 /*
   1703  * Dispatch a packet to all the listeners on interface bp.
   1704  *
   1705  * pkt       pointer to the packet, either a data buffer or an mbuf chain
   1706  * buflen    buffer length, if pkt is a data buffer
   1707  * cpfn      a function that can copy pkt into the listener's buffer
   1708  * pktlen    length of the packet
   1709  * direction BPF_D_IN or BPF_D_OUT
   1710  */
   1711 static inline void
   1712 bpf_deliver(struct bpf_if *bp, void *(*cpfn)(void *, const void *, size_t),
   1713     void *pkt, u_int pktlen, u_int buflen, const u_int direction)
   1714 {
   1715 	bool gottime = false;
   1716 	struct timespec ts;
   1717 	struct bpf_d *d;
   1718 	int s;
   1719 	u_int slen;
   1720 
   1721 	KASSERT(!cpu_intr_p());
   1722 
   1723 	/*
   1724 	 * Note that the IPL does not have to be raised at this point.
   1725 	 * The only problem that could arise here is that if two different
   1726 	 * interfaces shared any data.  This is not the case.
   1727 	 */
   1728 	s = pserialize_read_enter();
   1729 	BPFIF_DLIST_READER_FOREACH(d, bp) {
   1730 		if (direction == BPF_D_IN) {
   1731 			if (d->bd_direction == BPF_D_OUT)
   1732 				continue;
   1733 		} else { /* BPF_D_OUT */
   1734 			if (d->bd_direction == BPF_D_IN)
   1735 				continue;
   1736 		}
   1737 
   1738 		atomic_inc_ulong(&d->bd_rcount);
   1739 		BPF_STATINC(recv);
   1740 
   1741 		slen = bpf_xfilter(&d->bd_rfilter, pkt, pktlen, buflen);
   1742 		if (slen == 0)
   1743 			continue;
   1744 
   1745 		if (!gottime) {
   1746 			gottime = true;
   1747 			nanotime(&ts);
   1748 		}
   1749 		/* Assume catchpacket doesn't sleep */
   1750 		catchpacket(d, pkt, pktlen, slen, cpfn, &ts);
   1751 	}
   1752 	pserialize_read_exit(s);
   1753 }
   1754 
   1755 /*
   1756  * Incoming linkage from device drivers, when the head of the packet is in
   1757  * a buffer, and the tail is in an mbuf chain.
   1758  */
   1759 static void
   1760 _bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m,
   1761     u_int direction)
   1762 {
   1763 	u_int pktlen;
   1764 	struct mbuf mb;
   1765 
   1766 	/* Skip outgoing duplicate packets. */
   1767 	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) {
   1768 		m->m_flags &= ~M_PROMISC;
   1769 		return;
   1770 	}
   1771 
   1772 	pktlen = m_length(m) + dlen;
   1773 
   1774 	/*
   1775 	 * Craft on-stack mbuf suitable for passing to bpf_filter.
   1776 	 * Note that we cut corners here; we only set up what's
   1777 	 * absolutely needed--this mbuf should never go anywhere else.
   1778 	 */
   1779 	(void)memset(&mb, 0, sizeof(mb));
   1780 	mb.m_type = MT_DATA;
   1781 	mb.m_next = m;
   1782 	mb.m_data = data;
   1783 	mb.m_len = dlen;
   1784 
   1785 	bpf_deliver(bp, bpf_mcpy, &mb, pktlen, 0, direction);
   1786 }
   1787 
   1788 /*
   1789  * Incoming linkage from device drivers, when packet is in an mbuf chain.
   1790  */
   1791 static void
   1792 _bpf_mtap(struct bpf_if *bp, struct mbuf *m, u_int direction)
   1793 {
   1794 	void *(*cpfn)(void *, const void *, size_t);
   1795 	u_int pktlen, buflen;
   1796 	void *marg;
   1797 
   1798 	/* Skip outgoing duplicate packets. */
   1799 	if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) {
   1800 		m->m_flags &= ~M_PROMISC;
   1801 		return;
   1802 	}
   1803 
   1804 	pktlen = m_length(m);
   1805 
   1806 	/* Skip zero-sized packets. */
   1807 	if (__predict_false(pktlen == 0)) {
   1808 		return;
   1809 	}
   1810 
   1811 	if (pktlen == m->m_len) {
   1812 		cpfn = (void *)memcpy;
   1813 		marg = mtod(m, void *);
   1814 		buflen = pktlen;
   1815 		KASSERT(buflen != 0);
   1816 	} else {
   1817 		cpfn = bpf_mcpy;
   1818 		marg = m;
   1819 		buflen = 0;
   1820 	}
   1821 
   1822 	bpf_deliver(bp, cpfn, marg, pktlen, buflen, direction);
   1823 }
   1824 
   1825 /*
   1826  * We need to prepend the address family as
   1827  * a four byte field.  Cons up a dummy header
   1828  * to pacify bpf.  This is safe because bpf
   1829  * will only read from the mbuf (i.e., it won't
   1830  * try to free it or keep a pointer a to it).
   1831  */
   1832 static void
   1833 _bpf_mtap_af(struct bpf_if *bp, uint32_t af, struct mbuf *m, u_int direction)
   1834 {
   1835 	struct mbuf m0;
   1836 
   1837 	m0.m_type = MT_DATA;
   1838 	m0.m_flags = 0;
   1839 	m0.m_next = m;
   1840 	m0.m_nextpkt = NULL;
   1841 	m0.m_owner = NULL;
   1842 	m0.m_len = 4;
   1843 	m0.m_data = (char *)&af;
   1844 
   1845 	_bpf_mtap(bp, &m0, direction);
   1846 }
   1847 
   1848 /*
   1849  * Put the SLIP pseudo-"link header" in place.
   1850  * Note this M_PREPEND() should never fail,
   1851  * since we know we always have enough space
   1852  * in the input buffer.
   1853  */
   1854 static void
   1855 _bpf_mtap_sl_in(struct bpf_if *bp, u_char *chdr, struct mbuf **m)
   1856 {
   1857 	u_char *hp;
   1858 
   1859 	M_PREPEND(*m, SLIP_HDRLEN, M_DONTWAIT);
   1860 	if (*m == NULL)
   1861 		return;
   1862 
   1863 	hp = mtod(*m, u_char *);
   1864 	hp[SLX_DIR] = SLIPDIR_IN;
   1865 	(void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
   1866 
   1867 	_bpf_mtap(bp, *m, BPF_D_IN);
   1868 
   1869 	m_adj(*m, SLIP_HDRLEN);
   1870 }
   1871 
   1872 /*
   1873  * Put the SLIP pseudo-"link header" in
   1874  * place.  The compressed header is now
   1875  * at the beginning of the mbuf.
   1876  */
   1877 static void
   1878 _bpf_mtap_sl_out(struct bpf_if *bp, u_char *chdr, struct mbuf *m)
   1879 {
   1880 	struct mbuf m0;
   1881 	u_char *hp;
   1882 
   1883 	m0.m_type = MT_DATA;
   1884 	m0.m_flags = 0;
   1885 	m0.m_next = m;
   1886 	m0.m_nextpkt = NULL;
   1887 	m0.m_owner = NULL;
   1888 	m0.m_data = m0.m_dat;
   1889 	m0.m_len = SLIP_HDRLEN;
   1890 
   1891 	hp = mtod(&m0, u_char *);
   1892 
   1893 	hp[SLX_DIR] = SLIPDIR_OUT;
   1894 	(void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
   1895 
   1896 	_bpf_mtap(bp, &m0, BPF_D_OUT);
   1897 	m_freem(m);
   1898 }
   1899 
   1900 static struct mbuf *
   1901 bpf_mbuf_enqueue(struct bpf_if *bp, struct mbuf *m)
   1902 {
   1903 	struct mbuf *dup;
   1904 
   1905 	dup = m_dup(m, 0, M_COPYALL, M_NOWAIT);
   1906 	if (dup == NULL)
   1907 		return NULL;
   1908 
   1909 	if (bp->bif_mbuf_tail != NULL) {
   1910 		bp->bif_mbuf_tail->m_nextpkt = dup;
   1911 	} else {
   1912 		bp->bif_mbuf_head = dup;
   1913 	}
   1914 	bp->bif_mbuf_tail = dup;
   1915 #ifdef BPF_MTAP_SOFTINT_DEBUG
   1916 	log(LOG_DEBUG, "%s: enqueued mbuf=%p to %s\n",
   1917 	    __func__, dup, bp->bif_ifp->if_xname);
   1918 #endif
   1919 
   1920 	return dup;
   1921 }
   1922 
   1923 static struct mbuf *
   1924 bpf_mbuf_dequeue(struct bpf_if *bp)
   1925 {
   1926 	struct mbuf *m;
   1927 	int s;
   1928 
   1929 	/* XXX NOMPSAFE: assumed running on one CPU */
   1930 	s = splnet();
   1931 	m = bp->bif_mbuf_head;
   1932 	if (m != NULL) {
   1933 		bp->bif_mbuf_head = m->m_nextpkt;
   1934 		m->m_nextpkt = NULL;
   1935 
   1936 		if (bp->bif_mbuf_head == NULL)
   1937 			bp->bif_mbuf_tail = NULL;
   1938 #ifdef BPF_MTAP_SOFTINT_DEBUG
   1939 		log(LOG_DEBUG, "%s: dequeued mbuf=%p from %s\n",
   1940 		    __func__, m, bp->bif_ifp->if_xname);
   1941 #endif
   1942 	}
   1943 	splx(s);
   1944 
   1945 	return m;
   1946 }
   1947 
   1948 static void
   1949 bpf_mtap_si(void *arg)
   1950 {
   1951 	struct bpf_if *bp = arg;
   1952 	struct mbuf *m;
   1953 
   1954 	while ((m = bpf_mbuf_dequeue(bp)) != NULL) {
   1955 #ifdef BPF_MTAP_SOFTINT_DEBUG
   1956 		log(LOG_DEBUG, "%s: tapping mbuf=%p on %s\n",
   1957 		    __func__, m, bp->bif_ifp->if_xname);
   1958 #endif
   1959 		bpf_ops->bpf_mtap(bp, m, BPF_D_IN);
   1960 		m_freem(m);
   1961 	}
   1962 }
   1963 
   1964 static void
   1965 _bpf_mtap_softint(struct ifnet *ifp, struct mbuf *m)
   1966 {
   1967 	struct bpf_if *bp = ifp->if_bpf;
   1968 	struct mbuf *dup;
   1969 
   1970 	KASSERT(cpu_intr_p());
   1971 
   1972 	/* To avoid extra invocations of the softint */
   1973 	if (BPFIF_DLIST_READER_EMPTY(bp))
   1974 		return;
   1975 	KASSERT(bp->bif_si != NULL);
   1976 
   1977 	dup = bpf_mbuf_enqueue(bp, m);
   1978 	if (dup != NULL)
   1979 		softint_schedule(bp->bif_si);
   1980 }
   1981 
   1982 static int
   1983 bpf_hdrlen(struct bpf_d *d)
   1984 {
   1985 	int hdrlen = d->bd_bif->bif_hdrlen;
   1986 	/*
   1987 	 * Compute the length of the bpf header.  This is not necessarily
   1988 	 * equal to SIZEOF_BPF_HDR because we want to insert spacing such
   1989 	 * that the network layer header begins on a longword boundary (for
   1990 	 * performance reasons and to alleviate alignment restrictions).
   1991 	 */
   1992 #ifdef _LP64
   1993 	if (d->bd_compat32)
   1994 		return (BPF_WORDALIGN32(hdrlen + SIZEOF_BPF_HDR32) - hdrlen);
   1995 	else
   1996 #endif
   1997 		return (BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen);
   1998 }
   1999 
   2000 /*
   2001  * Move the packet data from interface memory (pkt) into the
   2002  * store buffer. Call the wakeup functions if it's time to wake up
   2003  * a listener (buffer full), "cpfn" is the routine called to do the
   2004  * actual data transfer. memcpy is passed in to copy contiguous chunks,
   2005  * while bpf_mcpy is passed in to copy mbuf chains.  In the latter case,
   2006  * pkt is really an mbuf.
   2007  */
   2008 static void
   2009 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
   2010     void *(*cpfn)(void *, const void *, size_t), struct timespec *ts)
   2011 {
   2012 	char *h;
   2013 	int totlen, curlen, caplen;
   2014 	int hdrlen = bpf_hdrlen(d);
   2015 	int do_wakeup = 0;
   2016 
   2017 	atomic_inc_ulong(&d->bd_ccount);
   2018 	BPF_STATINC(capt);
   2019 	/*
   2020 	 * Figure out how many bytes to move.  If the packet is
   2021 	 * greater or equal to the snapshot length, transfer that
   2022 	 * much.  Otherwise, transfer the whole packet (unless
   2023 	 * we hit the buffer size limit).
   2024 	 */
   2025 	totlen = hdrlen + uimin(snaplen, pktlen);
   2026 	if (totlen > d->bd_bufsize)
   2027 		totlen = d->bd_bufsize;
   2028 	/*
   2029 	 * If we adjusted totlen to fit the bufsize, it could be that
   2030 	 * totlen is smaller than hdrlen because of the link layer header.
   2031 	 */
   2032 	caplen = totlen - hdrlen;
   2033 	if (caplen < 0)
   2034 		caplen = 0;
   2035 
   2036 	mutex_enter(d->bd_buf_mtx);
   2037 	/*
   2038 	 * Round up the end of the previous packet to the next longword.
   2039 	 */
   2040 #ifdef _LP64
   2041 	if (d->bd_compat32)
   2042 		curlen = BPF_WORDALIGN32(d->bd_slen);
   2043 	else
   2044 #endif
   2045 		curlen = BPF_WORDALIGN(d->bd_slen);
   2046 	if (curlen + totlen > d->bd_bufsize) {
   2047 		/*
   2048 		 * This packet will overflow the storage buffer.
   2049 		 * Rotate the buffers if we can, then wakeup any
   2050 		 * pending reads.
   2051 		 */
   2052 		if (d->bd_fbuf == NULL) {
   2053 			mutex_exit(d->bd_buf_mtx);
   2054 			/*
   2055 			 * We haven't completed the previous read yet,
   2056 			 * so drop the packet.
   2057 			 */
   2058 			atomic_inc_ulong(&d->bd_dcount);
   2059 			BPF_STATINC(drop);
   2060 			return;
   2061 		}
   2062 		ROTATE_BUFFERS(d);
   2063 		do_wakeup = 1;
   2064 		curlen = 0;
   2065 	} else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
   2066 		/*
   2067 		 * Immediate mode is set, or the read timeout has
   2068 		 * already expired during a select call.  A packet
   2069 		 * arrived, so the reader should be woken up.
   2070 		 */
   2071 		do_wakeup = 1;
   2072 	}
   2073 
   2074 	/*
   2075 	 * Append the bpf header.
   2076 	 */
   2077 	h = (char *)d->bd_sbuf + curlen;
   2078 #ifdef _LP64
   2079 	if (d->bd_compat32) {
   2080 		struct bpf_hdr32 *hp32;
   2081 
   2082 		hp32 = (struct bpf_hdr32 *)h;
   2083 		hp32->bh_tstamp.tv_sec = ts->tv_sec;
   2084 		hp32->bh_tstamp.tv_usec = ts->tv_nsec / 1000;
   2085 		hp32->bh_datalen = pktlen;
   2086 		hp32->bh_hdrlen = hdrlen;
   2087 		hp32->bh_caplen = caplen;
   2088 	} else
   2089 #endif
   2090 	{
   2091 		struct bpf_hdr *hp;
   2092 
   2093 		hp = (struct bpf_hdr *)h;
   2094 		hp->bh_tstamp.tv_sec = ts->tv_sec;
   2095 		hp->bh_tstamp.tv_usec = ts->tv_nsec / 1000;
   2096 		hp->bh_datalen = pktlen;
   2097 		hp->bh_hdrlen = hdrlen;
   2098 		hp->bh_caplen = caplen;
   2099 	}
   2100 
   2101 	/*
   2102 	 * Copy the packet data into the store buffer and update its length.
   2103 	 */
   2104 	(*cpfn)(h + hdrlen, pkt, caplen);
   2105 	d->bd_slen = curlen + totlen;
   2106 
   2107 	/*
   2108 	 * Call bpf_wakeup after bd_slen has been updated so that kevent(2)
   2109 	 * will cause filt_bpfread() to be called with it adjusted.
   2110 	 */
   2111 	if (do_wakeup)
   2112 		bpf_wakeup(d);
   2113 
   2114 	mutex_exit(d->bd_buf_mtx);
   2115 }
   2116 
   2117 /*
   2118  * Initialize all nonzero fields of a descriptor.
   2119  */
   2120 static int
   2121 bpf_allocbufs(struct bpf_d *d)
   2122 {
   2123 
   2124 	d->bd_fbuf = kmem_zalloc(d->bd_bufsize, KM_NOSLEEP);
   2125 	if (!d->bd_fbuf)
   2126 		return (ENOBUFS);
   2127 	d->bd_sbuf = kmem_zalloc(d->bd_bufsize, KM_NOSLEEP);
   2128 	if (!d->bd_sbuf) {
   2129 		kmem_free(d->bd_fbuf, d->bd_bufsize);
   2130 		return (ENOBUFS);
   2131 	}
   2132 	d->bd_slen = 0;
   2133 	d->bd_hlen = 0;
   2134 	return (0);
   2135 }
   2136 
   2137 static void
   2138 bpf_free_filter(struct bpf_filter *filter)
   2139 {
   2140 
   2141 	KASSERT(filter != NULL);
   2142 
   2143 	if (filter->bf_insn != NULL)
   2144 		kmem_free(filter->bf_insn, filter->bf_size);
   2145 	if (filter->bf_jitcode != NULL)
   2146 		bpf_jit_freecode(filter->bf_jitcode);
   2147 	kmem_free(filter, sizeof(*filter));
   2148 }
   2149 
   2150 /*
   2151  * Free buffers currently in use by a descriptor.
   2152  * Called on close.
   2153  */
   2154 static void
   2155 bpf_freed(struct bpf_d *d)
   2156 {
   2157 	/*
   2158 	 * We don't need to lock out interrupts since this descriptor has
   2159 	 * been detached from its interface and it yet hasn't been marked
   2160 	 * free.
   2161 	 */
   2162 	if (d->bd_sbuf != NULL) {
   2163 		kmem_free(d->bd_sbuf, d->bd_bufsize);
   2164 		if (d->bd_hbuf != NULL)
   2165 			kmem_free(d->bd_hbuf, d->bd_bufsize);
   2166 		if (d->bd_fbuf != NULL)
   2167 			kmem_free(d->bd_fbuf, d->bd_bufsize);
   2168 	}
   2169 	if (d->bd_rfilter != NULL) {
   2170 		bpf_free_filter(d->bd_rfilter);
   2171 		d->bd_rfilter = NULL;
   2172 	}
   2173 	if (d->bd_wfilter != NULL) {
   2174 		bpf_free_filter(d->bd_wfilter);
   2175 		d->bd_wfilter = NULL;
   2176 	}
   2177 	d->bd_jitcode = NULL;
   2178 }
   2179 
   2180 /*
   2181  * Attach an interface to bpf.  dlt is the link layer type;
   2182  * hdrlen is the fixed size of the link header for the specified dlt
   2183  * (variable length headers not yet supported).
   2184  */
   2185 static void
   2186 _bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
   2187 {
   2188 	struct bpf_if *bp;
   2189 
   2190 	bp = kmem_alloc(sizeof(*bp), KM_SLEEP);
   2191 
   2192 	mutex_enter(&bpf_mtx);
   2193 	bp->bif_driverp = driverp;
   2194 	bp->bif_ifp = ifp;
   2195 	bp->bif_dlt = dlt;
   2196 	bp->bif_si = NULL;
   2197 	BPF_IFLIST_ENTRY_INIT(bp);
   2198 	PSLIST_INIT(&bp->bif_dlist_head);
   2199 	psref_target_init(&bp->bif_psref, bpf_psref_class);
   2200 	SLIST_INIT(&bp->bif_trackers);
   2201 
   2202 	BPF_IFLIST_WRITER_INSERT_HEAD(bp);
   2203 
   2204 	*bp->bif_driverp = NULL;
   2205 
   2206 	bp->bif_hdrlen = hdrlen;
   2207 	mutex_exit(&bpf_mtx);
   2208 #if 0
   2209 	printf("bpf: %s attached with dlt %x\n", ifp->if_xname, dlt);
   2210 #endif
   2211 }
   2212 
   2213 static void
   2214 _bpf_mtap_softint_init(struct ifnet *ifp)
   2215 {
   2216 	struct bpf_if *bp;
   2217 
   2218 	mutex_enter(&bpf_mtx);
   2219 	BPF_IFLIST_WRITER_FOREACH(bp) {
   2220 		if (bp->bif_ifp != ifp)
   2221 			continue;
   2222 
   2223 		bp->bif_mbuf_head = NULL;
   2224 		bp->bif_mbuf_tail = NULL;
   2225 		bp->bif_si = softint_establish(SOFTINT_NET, bpf_mtap_si, bp);
   2226 		if (bp->bif_si == NULL)
   2227 			panic("%s: softint_establish() failed", __func__);
   2228 		break;
   2229 	}
   2230 	mutex_exit(&bpf_mtx);
   2231 
   2232 	if (bp == NULL)
   2233 		panic("%s: no bpf_if found for %s", __func__, ifp->if_xname);
   2234 }
   2235 
   2236 /*
   2237  * Remove an interface from bpf.
   2238  */
   2239 static void
   2240 _bpfdetach(struct ifnet *ifp)
   2241 {
   2242 	struct bpf_if *bp;
   2243 	struct bpf_d *d;
   2244 	int s;
   2245 
   2246 	mutex_enter(&bpf_mtx);
   2247 	/* Nuke the vnodes for any open instances */
   2248 again_d:
   2249 	BPF_DLIST_WRITER_FOREACH(d) {
   2250 		mutex_enter(d->bd_mtx);
   2251 		if (d->bd_bif != NULL && d->bd_bif->bif_ifp == ifp) {
   2252 			/*
   2253 			 * Detach the descriptor from an interface now.
   2254 			 * It will be free'ed later by close routine.
   2255 			 */
   2256 			bpf_detachd(d);
   2257 			mutex_exit(d->bd_mtx);
   2258 			goto again_d;
   2259 		}
   2260 		mutex_exit(d->bd_mtx);
   2261 	}
   2262 
   2263 again:
   2264 	BPF_IFLIST_WRITER_FOREACH(bp) {
   2265 		if (bp->bif_ifp == ifp) {
   2266 			BPF_IFLIST_WRITER_REMOVE(bp);
   2267 
   2268 			pserialize_perform(bpf_psz);
   2269 			psref_target_destroy(&bp->bif_psref, bpf_psref_class);
   2270 
   2271 			while (!SLIST_EMPTY(&bp->bif_trackers)) {
   2272 				struct bpf_event_tracker *t =
   2273 				    SLIST_FIRST(&bp->bif_trackers);
   2274 				SLIST_REMOVE_HEAD(&bp->bif_trackers,
   2275 				    bet_entries);
   2276 				kmem_free(t, sizeof(*t));
   2277 			}
   2278 
   2279 			BPF_IFLIST_ENTRY_DESTROY(bp);
   2280 			if (bp->bif_si != NULL) {
   2281 				/* XXX NOMPSAFE: assumed running on one CPU */
   2282 				s = splnet();
   2283 				while (bp->bif_mbuf_head != NULL) {
   2284 					struct mbuf *m = bp->bif_mbuf_head;
   2285 					bp->bif_mbuf_head = m->m_nextpkt;
   2286 					m_freem(m);
   2287 				}
   2288 				splx(s);
   2289 				softint_disestablish(bp->bif_si);
   2290 			}
   2291 			kmem_free(bp, sizeof(*bp));
   2292 			goto again;
   2293 		}
   2294 	}
   2295 	mutex_exit(&bpf_mtx);
   2296 }
   2297 
   2298 /*
   2299  * Change the data link type of a interface.
   2300  */
   2301 static void
   2302 _bpf_change_type(struct ifnet *ifp, u_int dlt, u_int hdrlen)
   2303 {
   2304 	struct bpf_if *bp;
   2305 
   2306 	mutex_enter(&bpf_mtx);
   2307 	BPF_IFLIST_WRITER_FOREACH(bp) {
   2308 		if (bp->bif_driverp == &ifp->if_bpf)
   2309 			break;
   2310 	}
   2311 	if (bp == NULL)
   2312 		panic("bpf_change_type");
   2313 
   2314 	bp->bif_dlt = dlt;
   2315 
   2316 	bp->bif_hdrlen = hdrlen;
   2317 	mutex_exit(&bpf_mtx);
   2318 }
   2319 
   2320 /*
   2321  * Get a list of available data link type of the interface.
   2322  */
   2323 static int
   2324 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
   2325 {
   2326 	int n, error;
   2327 	struct ifnet *ifp;
   2328 	struct bpf_if *bp;
   2329 	int s, bound;
   2330 
   2331 	KASSERT(mutex_owned(d->bd_mtx));
   2332 
   2333 	ifp = d->bd_bif->bif_ifp;
   2334 	n = 0;
   2335 	error = 0;
   2336 
   2337 	bound = curlwp_bind();
   2338 	s = pserialize_read_enter();
   2339 	BPF_IFLIST_READER_FOREACH(bp) {
   2340 		if (bp->bif_ifp != ifp)
   2341 			continue;
   2342 		if (bfl->bfl_list != NULL) {
   2343 			struct psref psref;
   2344 
   2345 			if (n >= bfl->bfl_len) {
   2346 				pserialize_read_exit(s);
   2347 				return ENOMEM;
   2348 			}
   2349 
   2350 			bpf_if_acquire(bp, &psref);
   2351 			pserialize_read_exit(s);
   2352 
   2353 			error = copyout(&bp->bif_dlt,
   2354 			    bfl->bfl_list + n, sizeof(u_int));
   2355 
   2356 			s = pserialize_read_enter();
   2357 			bpf_if_release(bp, &psref);
   2358 		}
   2359 		n++;
   2360 	}
   2361 	pserialize_read_exit(s);
   2362 	curlwp_bindx(bound);
   2363 
   2364 	bfl->bfl_len = n;
   2365 	return error;
   2366 }
   2367 
   2368 /*
   2369  * Set the data link type of a BPF instance.
   2370  */
   2371 static int
   2372 bpf_setdlt(struct bpf_d *d, u_int dlt)
   2373 {
   2374 	int error, opromisc;
   2375 	struct ifnet *ifp;
   2376 	struct bpf_if *bp;
   2377 
   2378 	KASSERT(mutex_owned(&bpf_mtx));
   2379 	KASSERT(mutex_owned(d->bd_mtx));
   2380 
   2381 	if (d->bd_bif->bif_dlt == dlt)
   2382 		return 0;
   2383 	ifp = d->bd_bif->bif_ifp;
   2384 	BPF_IFLIST_WRITER_FOREACH(bp) {
   2385 		if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
   2386 			break;
   2387 	}
   2388 	if (bp == NULL)
   2389 		return EINVAL;
   2390 	opromisc = d->bd_promisc;
   2391 	bpf_detachd(d);
   2392 	BPFIF_DLIST_ENTRY_INIT(d);
   2393 	bpf_attachd(d, bp);
   2394 	reset_d(d);
   2395 	if (opromisc) {
   2396 		KERNEL_LOCK_UNLESS_NET_MPSAFE();
   2397 		error = ifpromisc(bp->bif_ifp, 1);
   2398 		KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
   2399 		if (error)
   2400 			printf("%s: bpf_setdlt: ifpromisc failed (%d)\n",
   2401 			    bp->bif_ifp->if_xname, error);
   2402 		else
   2403 			d->bd_promisc = 1;
   2404 	}
   2405 	return 0;
   2406 }
   2407 
   2408 static int
   2409 sysctl_net_bpf_maxbufsize(SYSCTLFN_ARGS)
   2410 {
   2411 	int newsize, error;
   2412 	struct sysctlnode node;
   2413 
   2414 	node = *rnode;
   2415 	node.sysctl_data = &newsize;
   2416 	newsize = bpf_maxbufsize;
   2417 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   2418 	if (error || newp == NULL)
   2419 		return (error);
   2420 
   2421 	if (newsize < BPF_MINBUFSIZE || newsize > BPF_MAXBUFSIZE)
   2422 		return (EINVAL);
   2423 
   2424 	bpf_maxbufsize = newsize;
   2425 
   2426 	return (0);
   2427 }
   2428 
   2429 #if defined(MODULAR) || defined(BPFJIT)
   2430 static int
   2431 sysctl_net_bpf_jit(SYSCTLFN_ARGS)
   2432 {
   2433 	bool newval;
   2434 	int error;
   2435 	struct sysctlnode node;
   2436 
   2437 	node = *rnode;
   2438 	node.sysctl_data = &newval;
   2439 	newval = bpf_jit;
   2440 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   2441 	if (error != 0 || newp == NULL)
   2442 		return error;
   2443 
   2444 	bpf_jit = newval;
   2445 	if (newval && bpfjit_module_ops.bj_generate_code == NULL) {
   2446 		printf("JIT compilation is postponed "
   2447 		    "until after bpfjit module is loaded\n");
   2448 	}
   2449 
   2450 	return 0;
   2451 }
   2452 #endif
   2453 
   2454 static int
   2455 sysctl_net_bpf_peers(SYSCTLFN_ARGS)
   2456 {
   2457 	int    error, elem_count;
   2458 	struct bpf_d	 *dp;
   2459 	struct bpf_d_ext  dpe;
   2460 	size_t len, needed, elem_size, out_size;
   2461 	char   *sp;
   2462 
   2463 	if (namelen == 1 && name[0] == CTL_QUERY)
   2464 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
   2465 
   2466 	if (namelen != 2)
   2467 		return (EINVAL);
   2468 
   2469 	/* BPF peers is privileged information. */
   2470 	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
   2471 	    KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, NULL, NULL, NULL);
   2472 	if (error)
   2473 		return (EPERM);
   2474 
   2475 	len = (oldp != NULL) ? *oldlenp : 0;
   2476 	sp = oldp;
   2477 	elem_size = name[0];
   2478 	elem_count = name[1];
   2479 	out_size = MIN(sizeof(dpe), elem_size);
   2480 	needed = 0;
   2481 
   2482 	if (elem_size < 1 || elem_count < 0)
   2483 		return (EINVAL);
   2484 
   2485 	mutex_enter(&bpf_mtx);
   2486 	BPF_DLIST_WRITER_FOREACH(dp) {
   2487 		if (len >= elem_size && elem_count > 0) {
   2488 #define BPF_EXT(field)	dpe.bde_ ## field = dp->bd_ ## field
   2489 			BPF_EXT(bufsize);
   2490 			BPF_EXT(promisc);
   2491 			BPF_EXT(state);
   2492 			BPF_EXT(immediate);
   2493 			BPF_EXT(hdrcmplt);
   2494 			BPF_EXT(direction);
   2495 			BPF_EXT(pid);
   2496 			BPF_EXT(rcount);
   2497 			BPF_EXT(dcount);
   2498 			BPF_EXT(ccount);
   2499 #undef BPF_EXT
   2500 			mutex_enter(dp->bd_mtx);
   2501 			if (dp->bd_bif)
   2502 				(void)strlcpy(dpe.bde_ifname,
   2503 				    dp->bd_bif->bif_ifp->if_xname,
   2504 				    IFNAMSIZ - 1);
   2505 			else
   2506 				dpe.bde_ifname[0] = '\0';
   2507 			dpe.bde_locked = dp->bd_locked;
   2508 			mutex_exit(dp->bd_mtx);
   2509 
   2510 			error = copyout(&dpe, sp, out_size);
   2511 			if (error)
   2512 				break;
   2513 			sp += elem_size;
   2514 			len -= elem_size;
   2515 		}
   2516 		needed += elem_size;
   2517 		if (elem_count > 0 && elem_count != INT_MAX)
   2518 			elem_count--;
   2519 	}
   2520 	mutex_exit(&bpf_mtx);
   2521 
   2522 	*oldlenp = needed;
   2523 
   2524 	return (error);
   2525 }
   2526 
   2527 static void
   2528 bpf_stats(void *p, void *arg, struct cpu_info *ci __unused)
   2529 {
   2530 	struct bpf_stat *const stats = p;
   2531 	struct bpf_stat *sum = arg;
   2532 
   2533 	int s = splnet();
   2534 
   2535 	sum->bs_recv += stats->bs_recv;
   2536 	sum->bs_drop += stats->bs_drop;
   2537 	sum->bs_capt += stats->bs_capt;
   2538 
   2539 	splx(s);
   2540 }
   2541 
   2542 static int
   2543 bpf_sysctl_gstats_handler(SYSCTLFN_ARGS)
   2544 {
   2545 	struct sysctlnode node;
   2546 	int error;
   2547 	struct bpf_stat sum;
   2548 
   2549 	memset(&sum, 0, sizeof(sum));
   2550 	node = *rnode;
   2551 
   2552 	percpu_foreach_xcall(bpf_gstats_percpu, XC_HIGHPRI_IPL(IPL_SOFTNET),
   2553 	    bpf_stats, &sum);
   2554 
   2555 	node.sysctl_data = &sum;
   2556 	node.sysctl_size = sizeof(sum);
   2557 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   2558 	if (error != 0 || newp == NULL)
   2559 		return error;
   2560 
   2561 	return 0;
   2562 }
   2563 
   2564 SYSCTL_SETUP(sysctl_net_bpf_setup, "bpf sysctls")
   2565 {
   2566 	const struct sysctlnode *node;
   2567 
   2568 	node = NULL;
   2569 	sysctl_createv(clog, 0, NULL, &node,
   2570 	    CTLFLAG_PERMANENT,
   2571 	    CTLTYPE_NODE, "bpf",
   2572 	    SYSCTL_DESCR("BPF options"),
   2573 	    NULL, 0, NULL, 0,
   2574 	    CTL_NET, CTL_CREATE, CTL_EOL);
   2575 	if (node != NULL) {
   2576 #if defined(MODULAR) || defined(BPFJIT)
   2577 		sysctl_createv(clog, 0, NULL, NULL,
   2578 		    CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2579 		    CTLTYPE_BOOL, "jit",
   2580 		    SYSCTL_DESCR("Toggle Just-In-Time compilation"),
   2581 		    sysctl_net_bpf_jit, 0, &bpf_jit, 0,
   2582 		    CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
   2583 #endif
   2584 		sysctl_createv(clog, 0, NULL, NULL,
   2585 		    CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2586 		    CTLTYPE_INT, "maxbufsize",
   2587 		    SYSCTL_DESCR("Maximum size for data capture buffer"),
   2588 		    sysctl_net_bpf_maxbufsize, 0, &bpf_maxbufsize, 0,
   2589 		    CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
   2590 		sysctl_createv(clog, 0, NULL, NULL,
   2591 		    CTLFLAG_PERMANENT,
   2592 		    CTLTYPE_STRUCT, "stats",
   2593 		    SYSCTL_DESCR("BPF stats"),
   2594 		    bpf_sysctl_gstats_handler, 0, NULL, 0,
   2595 		    CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
   2596 		sysctl_createv(clog, 0, NULL, NULL,
   2597 		    CTLFLAG_PERMANENT,
   2598 		    CTLTYPE_STRUCT, "peers",
   2599 		    SYSCTL_DESCR("BPF peers"),
   2600 		    sysctl_net_bpf_peers, 0, NULL, 0,
   2601 		    CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
   2602 	}
   2603 
   2604 }
   2605 
   2606 static int
   2607 _bpf_register_track_event(struct bpf_if **driverp,
   2608     void (*_fun)(struct bpf_if *, struct ifnet *, int, int))
   2609 {
   2610 	struct bpf_if *bp;
   2611 	struct bpf_event_tracker *t;
   2612 	int ret = ENOENT;
   2613 
   2614 	t = kmem_zalloc(sizeof(*t), KM_SLEEP);
   2615 	if (!t)
   2616 		return ENOMEM;
   2617 	t->bet_notify = _fun;
   2618 
   2619 	mutex_enter(&bpf_mtx);
   2620 	BPF_IFLIST_WRITER_FOREACH(bp) {
   2621 		if (bp->bif_driverp != driverp)
   2622 			continue;
   2623 		SLIST_INSERT_HEAD(&bp->bif_trackers, t, bet_entries);
   2624 		ret = 0;
   2625 		break;
   2626 	}
   2627 	mutex_exit(&bpf_mtx);
   2628 
   2629 	return ret;
   2630 }
   2631 
   2632 static int
   2633 _bpf_deregister_track_event(struct bpf_if **driverp,
   2634     void (*_fun)(struct bpf_if *, struct ifnet *, int, int))
   2635 {
   2636 	struct bpf_if *bp;
   2637 	struct bpf_event_tracker *t = NULL;
   2638 	int ret = ENOENT;
   2639 
   2640 	mutex_enter(&bpf_mtx);
   2641 	BPF_IFLIST_WRITER_FOREACH(bp) {
   2642 		if (bp->bif_driverp != driverp)
   2643 			continue;
   2644 		SLIST_FOREACH(t, &bp->bif_trackers, bet_entries) {
   2645 			if (t->bet_notify == _fun) {
   2646 				ret = 0;
   2647 				break;
   2648 			}
   2649 		}
   2650 		if (ret == 0)
   2651 			break;
   2652 	}
   2653 	if (ret == 0 && t && t->bet_notify == _fun) {
   2654 		SLIST_REMOVE(&bp->bif_trackers, t, bpf_event_tracker,
   2655 		    bet_entries);
   2656 	}
   2657 	mutex_exit(&bpf_mtx);
   2658 	if (ret == 0)
   2659 		kmem_free(t, sizeof(*t));
   2660 	return ret;
   2661 }
   2662 
   2663 struct bpf_ops bpf_ops_kernel = {
   2664 	.bpf_attach =		_bpfattach,
   2665 	.bpf_detach =		_bpfdetach,
   2666 	.bpf_change_type =	_bpf_change_type,
   2667 	.bpf_register_track_event = _bpf_register_track_event,
   2668 	.bpf_deregister_track_event = _bpf_deregister_track_event,
   2669 
   2670 	.bpf_mtap =		_bpf_mtap,
   2671 	.bpf_mtap2 =		_bpf_mtap2,
   2672 	.bpf_mtap_af =		_bpf_mtap_af,
   2673 	.bpf_mtap_sl_in =	_bpf_mtap_sl_in,
   2674 	.bpf_mtap_sl_out =	_bpf_mtap_sl_out,
   2675 
   2676 	.bpf_mtap_softint =		_bpf_mtap_softint,
   2677 	.bpf_mtap_softint_init =	_bpf_mtap_softint_init,
   2678 };
   2679 
   2680 MODULE(MODULE_CLASS_DRIVER, bpf, "bpf_filter");
   2681 
   2682 static int
   2683 bpf_modcmd(modcmd_t cmd, void *arg)
   2684 {
   2685 #ifdef _MODULE
   2686 	devmajor_t bmajor, cmajor;
   2687 #endif
   2688 	int error = 0;
   2689 
   2690 	switch (cmd) {
   2691 	case MODULE_CMD_INIT:
   2692 		bpf_init();
   2693 #ifdef _MODULE
   2694 		bmajor = cmajor = NODEVMAJOR;
   2695 		error = devsw_attach("bpf", NULL, &bmajor,
   2696 		    &bpf_cdevsw, &cmajor);
   2697 		if (error)
   2698 			break;
   2699 #endif
   2700 
   2701 		bpf_ops_handover_enter(&bpf_ops_kernel);
   2702 		atomic_swap_ptr(&bpf_ops, &bpf_ops_kernel);
   2703 		bpf_ops_handover_exit();
   2704 		break;
   2705 
   2706 	case MODULE_CMD_FINI:
   2707 		/*
   2708 		 * While there is no reference counting for bpf callers,
   2709 		 * unload could at least in theory be done similarly to
   2710 		 * system call disestablishment.  This should even be
   2711 		 * a little simpler:
   2712 		 *
   2713 		 * 1) replace op vector with stubs
   2714 		 * 2) post update to all cpus with xc
   2715 		 * 3) check that nobody is in bpf anymore
   2716 		 *    (it's doubtful we'd want something like l_sysent,
   2717 		 *     but we could do something like *signed* percpu
   2718 		 *     counters.  if the sum is 0, we're good).
   2719 		 * 4) if fail, unroll changes
   2720 		 *
   2721 		 * NOTE: change won't be atomic to the outside.  some
   2722 		 * packets may be not captured even if unload is
   2723 		 * not successful.  I think packet capture not working
   2724 		 * is a perfectly logical consequence of trying to
   2725 		 * disable packet capture.
   2726 		 */
   2727 		error = EOPNOTSUPP;
   2728 		break;
   2729 
   2730 	default:
   2731 		error = ENOTTY;
   2732 		break;
   2733 	}
   2734 
   2735 	return error;
   2736 }
   2737