bpf.c revision 180515
1/*- 2 * Copyright (c) 1990, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from the Stanford/CMU enet packet filter, 6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 8 * Berkeley Laboratory. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/net/bpf.c 180515 2008-07-14 22:41:48Z jkim $"); 39 40#include "opt_bpf.h" 41#include "opt_mac.h" 42#include "opt_netgraph.h" 43 44#include <sys/types.h> 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/conf.h> 48#include <sys/fcntl.h> 49#include <sys/malloc.h> 50#include <sys/mbuf.h> 51#include <sys/time.h> 52#include <sys/priv.h> 53#include <sys/proc.h> 54#include <sys/signalvar.h> 55#include <sys/filio.h> 56#include <sys/sockio.h> 57#include <sys/ttycom.h> 58#include <sys/uio.h> 59 60#include <sys/event.h> 61#include <sys/file.h> 62#include <sys/poll.h> 63#include <sys/proc.h> 64 65#include <sys/socket.h> 66 67#include <net/if.h> 68#include <net/bpf.h> 69#include <net/bpf_buffer.h> 70#ifdef BPF_JITTER 71#include <net/bpf_jitter.h> 72#endif 73#include <net/bpf_zerocopy.h> 74#include <net/bpfdesc.h> 75 76#include <netinet/in.h> 77#include <netinet/if_ether.h> 78#include <sys/kernel.h> 79#include <sys/sysctl.h> 80 81#include <net80211/ieee80211_freebsd.h> 82 83#include <security/mac/mac_framework.h> 84 85MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 86 87#if defined(DEV_BPF) || defined(NETGRAPH_BPF) 88 89#define PRINET 26 /* interruptible */ 90 91/* 92 * bpf_iflist is a list of BPF interface structures, each corresponding to a 93 * specific DLT. The same network interface might have several BPF interface 94 * structures registered by different layers in the stack (i.e., 802.11 95 * frames, ethernet frames, etc). 96 */ 97static LIST_HEAD(, bpf_if) bpf_iflist; 98static struct mtx bpf_mtx; /* bpf global lock */ 99static int bpf_bpfd_cnt; 100 101static void bpf_attachd(struct bpf_d *, struct bpf_if *); 102static void bpf_detachd(struct bpf_d *); 103static void bpf_freed(struct bpf_d *); 104static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 105 struct sockaddr *, int *, struct bpf_insn *); 106static int bpf_setif(struct bpf_d *, struct ifreq *); 107static void bpf_timed_out(void *); 108static __inline void 109 bpf_wakeup(struct bpf_d *); 110static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 111 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 112 struct timeval *); 113static void reset_d(struct bpf_d *); 114static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 115static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 116static int bpf_setdlt(struct bpf_d *, u_int); 117static void filt_bpfdetach(struct knote *); 118static int filt_bpfread(struct knote *, long); 119static void bpf_drvinit(void *); 120static void bpf_clone(void *, struct ucred *, char *, int, struct cdev **); 121static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 122 123SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 124static int bpf_maxinsns = BPF_MAXINSNS; 125SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 126 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 127static int bpf_zerocopy_enable = 0; 128SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 129 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 130SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_RW, 131 bpf_stats_sysctl, "bpf statistics portal"); 132 133static d_open_t bpfopen; 134static d_close_t bpfclose; 135static d_read_t bpfread; 136static d_write_t bpfwrite; 137static d_ioctl_t bpfioctl; 138static d_poll_t bpfpoll; 139static d_kqfilter_t bpfkqfilter; 140 141static struct cdevsw bpf_cdevsw = { 142 .d_version = D_VERSION, 143 .d_flags = D_TRACKCLOSE, 144 .d_open = bpfopen, 145 .d_close = bpfclose, 146 .d_read = bpfread, 147 .d_write = bpfwrite, 148 .d_ioctl = bpfioctl, 149 .d_poll = bpfpoll, 150 .d_name = "bpf", 151 .d_kqfilter = bpfkqfilter, 152}; 153 154static struct filterops bpfread_filtops = 155 { 1, NULL, filt_bpfdetach, filt_bpfread }; 156 157/* 158 * Wrapper functions for various buffering methods. If the set of buffer 159 * modes expands, we will probably want to introduce a switch data structure 160 * similar to protosw, et. 161 */ 162static void 163bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 164 u_int len) 165{ 166 167 BPFD_LOCK_ASSERT(d); 168 169 switch (d->bd_bufmode) { 170 case BPF_BUFMODE_BUFFER: 171 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 172 173 case BPF_BUFMODE_ZBUF: 174 d->bd_zcopy++; 175 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 176 177 default: 178 panic("bpf_buf_append_bytes"); 179 } 180} 181 182static void 183bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 184 u_int len) 185{ 186 187 BPFD_LOCK_ASSERT(d); 188 189 switch (d->bd_bufmode) { 190 case BPF_BUFMODE_BUFFER: 191 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 192 193 case BPF_BUFMODE_ZBUF: 194 d->bd_zcopy++; 195 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 196 197 default: 198 panic("bpf_buf_append_mbuf"); 199 } 200} 201 202/* 203 * This function gets called when the free buffer is re-assigned. 204 */ 205static void 206bpf_buf_reclaimed(struct bpf_d *d) 207{ 208 209 BPFD_LOCK_ASSERT(d); 210 211 switch (d->bd_bufmode) { 212 case BPF_BUFMODE_BUFFER: 213 return; 214 215 case BPF_BUFMODE_ZBUF: 216 bpf_zerocopy_buf_reclaimed(d); 217 return; 218 219 default: 220 panic("bpf_buf_reclaimed"); 221 } 222} 223 224/* 225 * If the buffer mechanism has a way to decide that a held buffer can be made 226 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 227 * returned if the buffer can be discarded, (0) is returned if it cannot. 228 */ 229static int 230bpf_canfreebuf(struct bpf_d *d) 231{ 232 233 BPFD_LOCK_ASSERT(d); 234 235 switch (d->bd_bufmode) { 236 case BPF_BUFMODE_ZBUF: 237 return (bpf_zerocopy_canfreebuf(d)); 238 } 239 return (0); 240} 241 242/* 243 * Allow the buffer model to indicate that the current store buffer is 244 * immutable, regardless of the appearance of space. Return (1) if the 245 * buffer is writable, and (0) if not. 246 */ 247static int 248bpf_canwritebuf(struct bpf_d *d) 249{ 250 251 BPFD_LOCK_ASSERT(d); 252 253 switch (d->bd_bufmode) { 254 case BPF_BUFMODE_ZBUF: 255 return (bpf_zerocopy_canwritebuf(d)); 256 } 257 return (1); 258} 259 260/* 261 * Notify buffer model that an attempt to write to the store buffer has 262 * resulted in a dropped packet, in which case the buffer may be considered 263 * full. 264 */ 265static void 266bpf_buffull(struct bpf_d *d) 267{ 268 269 BPFD_LOCK_ASSERT(d); 270 271 switch (d->bd_bufmode) { 272 case BPF_BUFMODE_ZBUF: 273 bpf_zerocopy_buffull(d); 274 break; 275 } 276} 277 278/* 279 * Notify the buffer model that a buffer has moved into the hold position. 280 */ 281void 282bpf_bufheld(struct bpf_d *d) 283{ 284 285 BPFD_LOCK_ASSERT(d); 286 287 switch (d->bd_bufmode) { 288 case BPF_BUFMODE_ZBUF: 289 bpf_zerocopy_bufheld(d); 290 break; 291 } 292} 293 294static void 295bpf_free(struct bpf_d *d) 296{ 297 298 switch (d->bd_bufmode) { 299 case BPF_BUFMODE_BUFFER: 300 return (bpf_buffer_free(d)); 301 302 case BPF_BUFMODE_ZBUF: 303 return (bpf_zerocopy_free(d)); 304 305 default: 306 panic("bpf_buf_free"); 307 } 308} 309 310static int 311bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 312{ 313 314 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 315 return (EOPNOTSUPP); 316 return (bpf_buffer_uiomove(d, buf, len, uio)); 317} 318 319static int 320bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 321{ 322 323 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 324 return (EOPNOTSUPP); 325 return (bpf_buffer_ioctl_sblen(d, i)); 326} 327 328static int 329bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 330{ 331 332 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 333 return (EOPNOTSUPP); 334 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 335} 336 337static int 338bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 339{ 340 341 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 342 return (EOPNOTSUPP); 343 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 344} 345 346static int 347bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 348{ 349 350 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 351 return (EOPNOTSUPP); 352 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 353} 354 355/* 356 * General BPF functions. 357 */ 358static int 359bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 360 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) 361{ 362 const struct ieee80211_bpf_params *p; 363 struct ether_header *eh; 364 struct mbuf *m; 365 int error; 366 int len; 367 int hlen; 368 int slen; 369 370 /* 371 * Build a sockaddr based on the data link layer type. 372 * We do this at this level because the ethernet header 373 * is copied directly into the data field of the sockaddr. 374 * In the case of SLIP, there is no header and the packet 375 * is forwarded as is. 376 * Also, we are careful to leave room at the front of the mbuf 377 * for the link level header. 378 */ 379 switch (linktype) { 380 381 case DLT_SLIP: 382 sockp->sa_family = AF_INET; 383 hlen = 0; 384 break; 385 386 case DLT_EN10MB: 387 sockp->sa_family = AF_UNSPEC; 388 /* XXX Would MAXLINKHDR be better? */ 389 hlen = ETHER_HDR_LEN; 390 break; 391 392 case DLT_FDDI: 393 sockp->sa_family = AF_IMPLINK; 394 hlen = 0; 395 break; 396 397 case DLT_RAW: 398 sockp->sa_family = AF_UNSPEC; 399 hlen = 0; 400 break; 401 402 case DLT_NULL: 403 /* 404 * null interface types require a 4 byte pseudo header which 405 * corresponds to the address family of the packet. 406 */ 407 sockp->sa_family = AF_UNSPEC; 408 hlen = 4; 409 break; 410 411 case DLT_ATM_RFC1483: 412 /* 413 * en atm driver requires 4-byte atm pseudo header. 414 * though it isn't standard, vpi:vci needs to be 415 * specified anyway. 416 */ 417 sockp->sa_family = AF_UNSPEC; 418 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 419 break; 420 421 case DLT_PPP: 422 sockp->sa_family = AF_UNSPEC; 423 hlen = 4; /* This should match PPP_HDRLEN */ 424 break; 425 426 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 427 sockp->sa_family = AF_IEEE80211; 428 hlen = 0; 429 break; 430 431 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 432 sockp->sa_family = AF_IEEE80211; 433 sockp->sa_len = 12; /* XXX != 0 */ 434 hlen = sizeof(struct ieee80211_bpf_params); 435 break; 436 437 default: 438 return (EIO); 439 } 440 441 len = uio->uio_resid; 442 443 if (len - hlen > ifp->if_mtu) 444 return (EMSGSIZE); 445 446 if ((unsigned)len > MJUM16BYTES) 447 return (EIO); 448 449 if (len <= MHLEN) 450 MGETHDR(m, M_WAIT, MT_DATA); 451 else if (len <= MCLBYTES) 452 m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR); 453 else 454 m = m_getjcl(M_WAIT, MT_DATA, M_PKTHDR, 455#if (MJUMPAGESIZE > MCLBYTES) 456 len <= MJUMPAGESIZE ? MJUMPAGESIZE : 457#endif 458 (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES)); 459 m->m_pkthdr.len = m->m_len = len; 460 m->m_pkthdr.rcvif = NULL; 461 *mp = m; 462 463 if (m->m_len < hlen) { 464 error = EPERM; 465 goto bad; 466 } 467 468 error = uiomove(mtod(m, u_char *), len, uio); 469 if (error) 470 goto bad; 471 472 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 473 if (slen == 0) { 474 error = EPERM; 475 goto bad; 476 } 477 478 /* Check for multicast destination */ 479 switch (linktype) { 480 case DLT_EN10MB: 481 eh = mtod(m, struct ether_header *); 482 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 483 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 484 ETHER_ADDR_LEN) == 0) 485 m->m_flags |= M_BCAST; 486 else 487 m->m_flags |= M_MCAST; 488 } 489 break; 490 } 491 492 /* 493 * Make room for link header, and copy it to sockaddr 494 */ 495 if (hlen != 0) { 496 if (sockp->sa_family == AF_IEEE80211) { 497 /* 498 * Collect true length from the parameter header 499 * NB: sockp is known to be zero'd so if we do a 500 * short copy unspecified parameters will be 501 * zero. 502 * NB: packet may not be aligned after stripping 503 * bpf params 504 * XXX check ibp_vers 505 */ 506 p = mtod(m, const struct ieee80211_bpf_params *); 507 hlen = p->ibp_len; 508 if (hlen > sizeof(sockp->sa_data)) { 509 error = EINVAL; 510 goto bad; 511 } 512 } 513 bcopy(m->m_data, sockp->sa_data, hlen); 514 } 515 *hdrlen = hlen; 516 517 return (0); 518bad: 519 m_freem(m); 520 return (error); 521} 522 523/* 524 * Attach file to the bpf interface, i.e. make d listen on bp. 525 */ 526static void 527bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 528{ 529 /* 530 * Point d at bp, and add d to the interface's list of listeners. 531 * Finally, point the driver's bpf cookie at the interface so 532 * it will divert packets to bpf. 533 */ 534 BPFIF_LOCK(bp); 535 d->bd_bif = bp; 536 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 537 538 bpf_bpfd_cnt++; 539 BPFIF_UNLOCK(bp); 540} 541 542/* 543 * Detach a file from its interface. 544 */ 545static void 546bpf_detachd(struct bpf_d *d) 547{ 548 int error; 549 struct bpf_if *bp; 550 struct ifnet *ifp; 551 552 bp = d->bd_bif; 553 BPFIF_LOCK(bp); 554 BPFD_LOCK(d); 555 ifp = d->bd_bif->bif_ifp; 556 557 /* 558 * Remove d from the interface's descriptor list. 559 */ 560 LIST_REMOVE(d, bd_next); 561 562 bpf_bpfd_cnt--; 563 d->bd_bif = NULL; 564 BPFD_UNLOCK(d); 565 BPFIF_UNLOCK(bp); 566 567 /* 568 * Check if this descriptor had requested promiscuous mode. 569 * If so, turn it off. 570 */ 571 if (d->bd_promisc) { 572 d->bd_promisc = 0; 573 error = ifpromisc(ifp, 0); 574 if (error != 0 && error != ENXIO) { 575 /* 576 * ENXIO can happen if a pccard is unplugged 577 * Something is really wrong if we were able to put 578 * the driver into promiscuous mode, but can't 579 * take it out. 580 */ 581 if_printf(bp->bif_ifp, 582 "bpf_detach: ifpromisc failed (%d)\n", error); 583 } 584 } 585} 586 587/* 588 * Open ethernet device. Returns ENXIO for illegal minor device number, 589 * EBUSY if file is open by another process. 590 */ 591/* ARGSUSED */ 592static int 593bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 594{ 595 struct bpf_d *d; 596 597 mtx_lock(&bpf_mtx); 598 d = dev->si_drv1; 599 /* 600 * Each minor can be opened by only one process. If the requested 601 * minor is in use, return EBUSY. 602 */ 603 if (d != NULL) { 604 mtx_unlock(&bpf_mtx); 605 return (EBUSY); 606 } 607 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 608 mtx_unlock(&bpf_mtx); 609 610 if ((dev->si_flags & SI_NAMED) == 0) 611 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 612 "bpf%d", dev2unit(dev)); 613 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 614 dev->si_drv1 = d; 615 616 /* 617 * For historical reasons, perform a one-time initialization call to 618 * the buffer routines, even though we're not yet committed to a 619 * particular buffer method. 620 */ 621 bpf_buffer_init(d); 622 d->bd_bufmode = BPF_BUFMODE_BUFFER; 623 d->bd_sig = SIGIO; 624 d->bd_direction = BPF_D_INOUT; 625 d->bd_pid = td->td_proc->p_pid; 626#ifdef MAC 627 mac_bpfdesc_init(d); 628 mac_bpfdesc_create(td->td_ucred, d); 629#endif 630 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 631 callout_init(&d->bd_callout, CALLOUT_MPSAFE); 632 knlist_init(&d->bd_sel.si_note, &d->bd_mtx, NULL, NULL, NULL); 633 634 return (0); 635} 636 637/* 638 * Close the descriptor by detaching it from its interface, 639 * deallocating its buffers, and marking it free. 640 */ 641/* ARGSUSED */ 642static int 643bpfclose(struct cdev *dev, int flags, int fmt, struct thread *td) 644{ 645 struct bpf_d *d = dev->si_drv1; 646 647 BPFD_LOCK(d); 648 if (d->bd_state == BPF_WAITING) 649 callout_stop(&d->bd_callout); 650 d->bd_state = BPF_IDLE; 651 BPFD_UNLOCK(d); 652 funsetown(&d->bd_sigio); 653 mtx_lock(&bpf_mtx); 654 if (d->bd_bif) 655 bpf_detachd(d); 656 mtx_unlock(&bpf_mtx); 657 selwakeuppri(&d->bd_sel, PRINET); 658#ifdef MAC 659 mac_bpfdesc_destroy(d); 660#endif /* MAC */ 661 knlist_destroy(&d->bd_sel.si_note); 662 bpf_freed(d); 663 dev->si_drv1 = NULL; 664 free(d, M_BPF); 665 666 return (0); 667} 668 669/* 670 * bpfread - read next chunk of packets from buffers 671 */ 672static int 673bpfread(struct cdev *dev, struct uio *uio, int ioflag) 674{ 675 struct bpf_d *d = dev->si_drv1; 676 int timed_out; 677 int error; 678 679 /* 680 * Restrict application to use a buffer the same size as 681 * as kernel buffers. 682 */ 683 if (uio->uio_resid != d->bd_bufsize) 684 return (EINVAL); 685 686 BPFD_LOCK(d); 687 d->bd_pid = curthread->td_proc->p_pid; 688 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 689 BPFD_UNLOCK(d); 690 return (EOPNOTSUPP); 691 } 692 if (d->bd_state == BPF_WAITING) 693 callout_stop(&d->bd_callout); 694 timed_out = (d->bd_state == BPF_TIMED_OUT); 695 d->bd_state = BPF_IDLE; 696 /* 697 * If the hold buffer is empty, then do a timed sleep, which 698 * ends when the timeout expires or when enough packets 699 * have arrived to fill the store buffer. 700 */ 701 while (d->bd_hbuf == NULL) { 702 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 703 /* 704 * A packet(s) either arrived since the previous 705 * read or arrived while we were asleep. 706 * Rotate the buffers and return what's here. 707 */ 708 ROTATE_BUFFERS(d); 709 break; 710 } 711 712 /* 713 * No data is available, check to see if the bpf device 714 * is still pointed at a real interface. If not, return 715 * ENXIO so that the userland process knows to rebind 716 * it before using it again. 717 */ 718 if (d->bd_bif == NULL) { 719 BPFD_UNLOCK(d); 720 return (ENXIO); 721 } 722 723 if (ioflag & O_NONBLOCK) { 724 BPFD_UNLOCK(d); 725 return (EWOULDBLOCK); 726 } 727 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 728 "bpf", d->bd_rtout); 729 if (error == EINTR || error == ERESTART) { 730 BPFD_UNLOCK(d); 731 return (error); 732 } 733 if (error == EWOULDBLOCK) { 734 /* 735 * On a timeout, return what's in the buffer, 736 * which may be nothing. If there is something 737 * in the store buffer, we can rotate the buffers. 738 */ 739 if (d->bd_hbuf) 740 /* 741 * We filled up the buffer in between 742 * getting the timeout and arriving 743 * here, so we don't need to rotate. 744 */ 745 break; 746 747 if (d->bd_slen == 0) { 748 BPFD_UNLOCK(d); 749 return (0); 750 } 751 ROTATE_BUFFERS(d); 752 break; 753 } 754 } 755 /* 756 * At this point, we know we have something in the hold slot. 757 */ 758 BPFD_UNLOCK(d); 759 760 /* 761 * Move data from hold buffer into user space. 762 * We know the entire buffer is transferred since 763 * we checked above that the read buffer is bpf_bufsize bytes. 764 * 765 * XXXRW: More synchronization needed here: what if a second thread 766 * issues a read on the same fd at the same time? Don't want this 767 * getting invalidated. 768 */ 769 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 770 771 BPFD_LOCK(d); 772 d->bd_fbuf = d->bd_hbuf; 773 d->bd_hbuf = NULL; 774 d->bd_hlen = 0; 775 bpf_buf_reclaimed(d); 776 BPFD_UNLOCK(d); 777 778 return (error); 779} 780 781/* 782 * If there are processes sleeping on this descriptor, wake them up. 783 */ 784static __inline void 785bpf_wakeup(struct bpf_d *d) 786{ 787 788 BPFD_LOCK_ASSERT(d); 789 if (d->bd_state == BPF_WAITING) { 790 callout_stop(&d->bd_callout); 791 d->bd_state = BPF_IDLE; 792 } 793 wakeup(d); 794 if (d->bd_async && d->bd_sig && d->bd_sigio) 795 pgsigio(&d->bd_sigio, d->bd_sig, 0); 796 797 selwakeuppri(&d->bd_sel, PRINET); 798 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 799} 800 801static void 802bpf_timed_out(void *arg) 803{ 804 struct bpf_d *d = (struct bpf_d *)arg; 805 806 BPFD_LOCK(d); 807 if (d->bd_state == BPF_WAITING) { 808 d->bd_state = BPF_TIMED_OUT; 809 if (d->bd_slen != 0) 810 bpf_wakeup(d); 811 } 812 BPFD_UNLOCK(d); 813} 814 815static int 816bpf_ready(struct bpf_d *d) 817{ 818 819 BPFD_LOCK_ASSERT(d); 820 821 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 822 return (1); 823 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 824 d->bd_slen != 0) 825 return (1); 826 return (0); 827} 828 829static int 830bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 831{ 832 struct bpf_d *d = dev->si_drv1; 833 struct ifnet *ifp; 834 struct mbuf *m, *mc; 835 struct sockaddr dst; 836 int error, hlen; 837 838 d->bd_pid = curthread->td_proc->p_pid; 839 d->bd_wcount++; 840 if (d->bd_bif == NULL) { 841 d->bd_wdcount++; 842 return (ENXIO); 843 } 844 845 ifp = d->bd_bif->bif_ifp; 846 847 if ((ifp->if_flags & IFF_UP) == 0) { 848 d->bd_wdcount++; 849 return (ENETDOWN); 850 } 851 852 if (uio->uio_resid == 0) { 853 d->bd_wdcount++; 854 return (0); 855 } 856 857 bzero(&dst, sizeof(dst)); 858 m = NULL; 859 hlen = 0; 860 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 861 &m, &dst, &hlen, d->bd_wfilter); 862 if (error) { 863 d->bd_wdcount++; 864 return (error); 865 } 866 d->bd_wfcount++; 867 if (d->bd_hdrcmplt) 868 dst.sa_family = pseudo_AF_HDRCMPLT; 869 870 if (d->bd_feedback) { 871 mc = m_dup(m, M_DONTWAIT); 872 if (mc != NULL) 873 mc->m_pkthdr.rcvif = ifp; 874 /* Set M_PROMISC for outgoing packets to be discarded. */ 875 if (d->bd_direction == BPF_D_INOUT) 876 m->m_flags |= M_PROMISC; 877 } else 878 mc = NULL; 879 880 m->m_pkthdr.len -= hlen; 881 m->m_len -= hlen; 882 m->m_data += hlen; /* XXX */ 883 884#ifdef MAC 885 BPFD_LOCK(d); 886 mac_bpfdesc_create_mbuf(d, m); 887 if (mc != NULL) 888 mac_bpfdesc_create_mbuf(d, mc); 889 BPFD_UNLOCK(d); 890#endif 891 892 error = (*ifp->if_output)(ifp, m, &dst, NULL); 893 if (error) 894 d->bd_wdcount++; 895 896 if (mc != NULL) { 897 if (error == 0) 898 (*ifp->if_input)(ifp, mc); 899 else 900 m_freem(mc); 901 } 902 903 return (error); 904} 905 906/* 907 * Reset a descriptor by flushing its packet buffer and clearing the 908 * receive and drop counts. 909 */ 910static void 911reset_d(struct bpf_d *d) 912{ 913 914 mtx_assert(&d->bd_mtx, MA_OWNED); 915 if (d->bd_hbuf) { 916 /* Free the hold buffer. */ 917 d->bd_fbuf = d->bd_hbuf; 918 d->bd_hbuf = NULL; 919 bpf_buf_reclaimed(d); 920 } 921 d->bd_slen = 0; 922 d->bd_hlen = 0; 923 d->bd_rcount = 0; 924 d->bd_dcount = 0; 925 d->bd_fcount = 0; 926 d->bd_wcount = 0; 927 d->bd_wfcount = 0; 928 d->bd_wdcount = 0; 929 d->bd_zcopy = 0; 930} 931 932/* 933 * FIONREAD Check for read packet available. 934 * SIOCGIFADDR Get interface address - convenient hook to driver. 935 * BIOCGBLEN Get buffer len [for read()]. 936 * BIOCSETF Set read filter. 937 * BIOCSETFNR Set read filter without resetting descriptor. 938 * BIOCSETWF Set write filter. 939 * BIOCFLUSH Flush read packet buffer. 940 * BIOCPROMISC Put interface into promiscuous mode. 941 * BIOCGDLT Get link layer type. 942 * BIOCGETIF Get interface name. 943 * BIOCSETIF Set interface. 944 * BIOCSRTIMEOUT Set read timeout. 945 * BIOCGRTIMEOUT Get read timeout. 946 * BIOCGSTATS Get packet stats. 947 * BIOCIMMEDIATE Set immediate mode. 948 * BIOCVERSION Get filter language version. 949 * BIOCGHDRCMPLT Get "header already complete" flag 950 * BIOCSHDRCMPLT Set "header already complete" flag 951 * BIOCGDIRECTION Get packet direction flag 952 * BIOCSDIRECTION Set packet direction flag 953 * BIOCLOCK Set "locked" flag 954 * BIOCFEEDBACK Set packet feedback mode. 955 * BIOCSETZBUF Set current zero-copy buffer locations. 956 * BIOCGETZMAX Get maximum zero-copy buffer size. 957 * BIOCROTZBUF Force rotation of zero-copy buffer 958 * BIOCSETBUFMODE Set buffer mode. 959 * BIOCGETBUFMODE Get current buffer mode. 960 */ 961/* ARGSUSED */ 962static int 963bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 964 struct thread *td) 965{ 966 struct bpf_d *d = dev->si_drv1; 967 int error = 0; 968 969 /* 970 * Refresh PID associated with this descriptor. 971 */ 972 BPFD_LOCK(d); 973 d->bd_pid = td->td_proc->p_pid; 974 if (d->bd_state == BPF_WAITING) 975 callout_stop(&d->bd_callout); 976 d->bd_state = BPF_IDLE; 977 BPFD_UNLOCK(d); 978 979 if (d->bd_locked == 1) { 980 switch (cmd) { 981 case BIOCGBLEN: 982 case BIOCFLUSH: 983 case BIOCGDLT: 984 case BIOCGDLTLIST: 985 case BIOCGETIF: 986 case BIOCGRTIMEOUT: 987 case BIOCGSTATS: 988 case BIOCVERSION: 989 case BIOCGRSIG: 990 case BIOCGHDRCMPLT: 991 case BIOCFEEDBACK: 992 case FIONREAD: 993 case BIOCLOCK: 994 case BIOCSRTIMEOUT: 995 case BIOCIMMEDIATE: 996 case TIOCGPGRP: 997 case BIOCROTZBUF: 998 break; 999 default: 1000 return (EPERM); 1001 } 1002 } 1003 switch (cmd) { 1004 1005 default: 1006 error = EINVAL; 1007 break; 1008 1009 /* 1010 * Check for read packet available. 1011 */ 1012 case FIONREAD: 1013 { 1014 int n; 1015 1016 BPFD_LOCK(d); 1017 n = d->bd_slen; 1018 if (d->bd_hbuf) 1019 n += d->bd_hlen; 1020 BPFD_UNLOCK(d); 1021 1022 *(int *)addr = n; 1023 break; 1024 } 1025 1026 case SIOCGIFADDR: 1027 { 1028 struct ifnet *ifp; 1029 1030 if (d->bd_bif == NULL) 1031 error = EINVAL; 1032 else { 1033 ifp = d->bd_bif->bif_ifp; 1034 error = (*ifp->if_ioctl)(ifp, cmd, addr); 1035 } 1036 break; 1037 } 1038 1039 /* 1040 * Get buffer len [for read()]. 1041 */ 1042 case BIOCGBLEN: 1043 *(u_int *)addr = d->bd_bufsize; 1044 break; 1045 1046 /* 1047 * Set buffer length. 1048 */ 1049 case BIOCSBLEN: 1050 error = bpf_ioctl_sblen(d, (u_int *)addr); 1051 break; 1052 1053 /* 1054 * Set link layer read filter. 1055 */ 1056 case BIOCSETF: 1057 case BIOCSETFNR: 1058 case BIOCSETWF: 1059 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1060 break; 1061 1062 /* 1063 * Flush read packet buffer. 1064 */ 1065 case BIOCFLUSH: 1066 BPFD_LOCK(d); 1067 reset_d(d); 1068 BPFD_UNLOCK(d); 1069 break; 1070 1071 /* 1072 * Put interface into promiscuous mode. 1073 */ 1074 case BIOCPROMISC: 1075 if (d->bd_bif == NULL) { 1076 /* 1077 * No interface attached yet. 1078 */ 1079 error = EINVAL; 1080 break; 1081 } 1082 if (d->bd_promisc == 0) { 1083 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1084 if (error == 0) 1085 d->bd_promisc = 1; 1086 } 1087 break; 1088 1089 /* 1090 * Get current data link type. 1091 */ 1092 case BIOCGDLT: 1093 if (d->bd_bif == NULL) 1094 error = EINVAL; 1095 else 1096 *(u_int *)addr = d->bd_bif->bif_dlt; 1097 break; 1098 1099 /* 1100 * Get a list of supported data link types. 1101 */ 1102 case BIOCGDLTLIST: 1103 if (d->bd_bif == NULL) 1104 error = EINVAL; 1105 else 1106 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1107 break; 1108 1109 /* 1110 * Set data link type. 1111 */ 1112 case BIOCSDLT: 1113 if (d->bd_bif == NULL) 1114 error = EINVAL; 1115 else 1116 error = bpf_setdlt(d, *(u_int *)addr); 1117 break; 1118 1119 /* 1120 * Get interface name. 1121 */ 1122 case BIOCGETIF: 1123 if (d->bd_bif == NULL) 1124 error = EINVAL; 1125 else { 1126 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1127 struct ifreq *const ifr = (struct ifreq *)addr; 1128 1129 strlcpy(ifr->ifr_name, ifp->if_xname, 1130 sizeof(ifr->ifr_name)); 1131 } 1132 break; 1133 1134 /* 1135 * Set interface. 1136 */ 1137 case BIOCSETIF: 1138 error = bpf_setif(d, (struct ifreq *)addr); 1139 break; 1140 1141 /* 1142 * Set read timeout. 1143 */ 1144 case BIOCSRTIMEOUT: 1145 { 1146 struct timeval *tv = (struct timeval *)addr; 1147 1148 /* 1149 * Subtract 1 tick from tvtohz() since this isn't 1150 * a one-shot timer. 1151 */ 1152 if ((error = itimerfix(tv)) == 0) 1153 d->bd_rtout = tvtohz(tv) - 1; 1154 break; 1155 } 1156 1157 /* 1158 * Get read timeout. 1159 */ 1160 case BIOCGRTIMEOUT: 1161 { 1162 struct timeval *tv = (struct timeval *)addr; 1163 1164 tv->tv_sec = d->bd_rtout / hz; 1165 tv->tv_usec = (d->bd_rtout % hz) * tick; 1166 break; 1167 } 1168 1169 /* 1170 * Get packet stats. 1171 */ 1172 case BIOCGSTATS: 1173 { 1174 struct bpf_stat *bs = (struct bpf_stat *)addr; 1175 1176 /* XXXCSJP overflow */ 1177 bs->bs_recv = d->bd_rcount; 1178 bs->bs_drop = d->bd_dcount; 1179 break; 1180 } 1181 1182 /* 1183 * Set immediate mode. 1184 */ 1185 case BIOCIMMEDIATE: 1186 d->bd_immediate = *(u_int *)addr; 1187 break; 1188 1189 case BIOCVERSION: 1190 { 1191 struct bpf_version *bv = (struct bpf_version *)addr; 1192 1193 bv->bv_major = BPF_MAJOR_VERSION; 1194 bv->bv_minor = BPF_MINOR_VERSION; 1195 break; 1196 } 1197 1198 /* 1199 * Get "header already complete" flag 1200 */ 1201 case BIOCGHDRCMPLT: 1202 *(u_int *)addr = d->bd_hdrcmplt; 1203 break; 1204 1205 /* 1206 * Set "header already complete" flag 1207 */ 1208 case BIOCSHDRCMPLT: 1209 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1210 break; 1211 1212 /* 1213 * Get packet direction flag 1214 */ 1215 case BIOCGDIRECTION: 1216 *(u_int *)addr = d->bd_direction; 1217 break; 1218 1219 /* 1220 * Set packet direction flag 1221 */ 1222 case BIOCSDIRECTION: 1223 { 1224 u_int direction; 1225 1226 direction = *(u_int *)addr; 1227 switch (direction) { 1228 case BPF_D_IN: 1229 case BPF_D_INOUT: 1230 case BPF_D_OUT: 1231 d->bd_direction = direction; 1232 break; 1233 default: 1234 error = EINVAL; 1235 } 1236 } 1237 break; 1238 1239 case BIOCFEEDBACK: 1240 d->bd_feedback = *(u_int *)addr; 1241 break; 1242 1243 case BIOCLOCK: 1244 d->bd_locked = 1; 1245 break; 1246 1247 case FIONBIO: /* Non-blocking I/O */ 1248 break; 1249 1250 case FIOASYNC: /* Send signal on receive packets */ 1251 d->bd_async = *(int *)addr; 1252 break; 1253 1254 case FIOSETOWN: 1255 error = fsetown(*(int *)addr, &d->bd_sigio); 1256 break; 1257 1258 case FIOGETOWN: 1259 *(int *)addr = fgetown(&d->bd_sigio); 1260 break; 1261 1262 /* This is deprecated, FIOSETOWN should be used instead. */ 1263 case TIOCSPGRP: 1264 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1265 break; 1266 1267 /* This is deprecated, FIOGETOWN should be used instead. */ 1268 case TIOCGPGRP: 1269 *(int *)addr = -fgetown(&d->bd_sigio); 1270 break; 1271 1272 case BIOCSRSIG: /* Set receive signal */ 1273 { 1274 u_int sig; 1275 1276 sig = *(u_int *)addr; 1277 1278 if (sig >= NSIG) 1279 error = EINVAL; 1280 else 1281 d->bd_sig = sig; 1282 break; 1283 } 1284 case BIOCGRSIG: 1285 *(u_int *)addr = d->bd_sig; 1286 break; 1287 1288 case BIOCGETBUFMODE: 1289 *(u_int *)addr = d->bd_bufmode; 1290 break; 1291 1292 case BIOCSETBUFMODE: 1293 /* 1294 * Allow the buffering mode to be changed as long as we 1295 * haven't yet committed to a particular mode. Our 1296 * definition of commitment, for now, is whether or not a 1297 * buffer has been allocated or an interface attached, since 1298 * that's the point where things get tricky. 1299 */ 1300 switch (*(u_int *)addr) { 1301 case BPF_BUFMODE_BUFFER: 1302 break; 1303 1304 case BPF_BUFMODE_ZBUF: 1305 if (bpf_zerocopy_enable) 1306 break; 1307 /* FALLSTHROUGH */ 1308 1309 default: 1310 return (EINVAL); 1311 } 1312 1313 BPFD_LOCK(d); 1314 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1315 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1316 BPFD_UNLOCK(d); 1317 return (EBUSY); 1318 } 1319 d->bd_bufmode = *(u_int *)addr; 1320 BPFD_UNLOCK(d); 1321 break; 1322 1323 case BIOCGETZMAX: 1324 return (bpf_ioctl_getzmax(td, d, (size_t *)addr)); 1325 1326 case BIOCSETZBUF: 1327 return (bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr)); 1328 1329 case BIOCROTZBUF: 1330 return (bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr)); 1331 } 1332 return (error); 1333} 1334 1335/* 1336 * Set d's packet filter program to fp. If this file already has a filter, 1337 * free it and replace it. Returns EINVAL for bogus requests. 1338 */ 1339static int 1340bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1341{ 1342 struct bpf_insn *fcode, *old; 1343 u_int wfilter, flen, size; 1344#ifdef BPF_JITTER 1345 bpf_jit_filter *ofunc; 1346#endif 1347 1348 if (cmd == BIOCSETWF) { 1349 old = d->bd_wfilter; 1350 wfilter = 1; 1351#ifdef BPF_JITTER 1352 ofunc = NULL; 1353#endif 1354 } else { 1355 wfilter = 0; 1356 old = d->bd_rfilter; 1357#ifdef BPF_JITTER 1358 ofunc = d->bd_bfilter; 1359#endif 1360 } 1361 if (fp->bf_insns == NULL) { 1362 if (fp->bf_len != 0) 1363 return (EINVAL); 1364 BPFD_LOCK(d); 1365 if (wfilter) 1366 d->bd_wfilter = NULL; 1367 else { 1368 d->bd_rfilter = NULL; 1369#ifdef BPF_JITTER 1370 d->bd_bfilter = NULL; 1371#endif 1372 if (cmd == BIOCSETF) 1373 reset_d(d); 1374 } 1375 BPFD_UNLOCK(d); 1376 if (old != NULL) 1377 free((caddr_t)old, M_BPF); 1378#ifdef BPF_JITTER 1379 if (ofunc != NULL) 1380 bpf_destroy_jit_filter(ofunc); 1381#endif 1382 return (0); 1383 } 1384 flen = fp->bf_len; 1385 if (flen > bpf_maxinsns) 1386 return (EINVAL); 1387 1388 size = flen * sizeof(*fp->bf_insns); 1389 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 1390 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 1391 bpf_validate(fcode, (int)flen)) { 1392 BPFD_LOCK(d); 1393 if (wfilter) 1394 d->bd_wfilter = fcode; 1395 else { 1396 d->bd_rfilter = fcode; 1397#ifdef BPF_JITTER 1398 d->bd_bfilter = bpf_jitter(fcode, flen); 1399#endif 1400 if (cmd == BIOCSETF) 1401 reset_d(d); 1402 } 1403 BPFD_UNLOCK(d); 1404 if (old != NULL) 1405 free((caddr_t)old, M_BPF); 1406#ifdef BPF_JITTER 1407 if (ofunc != NULL) 1408 bpf_destroy_jit_filter(ofunc); 1409#endif 1410 1411 return (0); 1412 } 1413 free((caddr_t)fcode, M_BPF); 1414 return (EINVAL); 1415} 1416 1417/* 1418 * Detach a file from its current interface (if attached at all) and attach 1419 * to the interface indicated by the name stored in ifr. 1420 * Return an errno or 0. 1421 */ 1422static int 1423bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1424{ 1425 struct bpf_if *bp; 1426 struct ifnet *theywant; 1427 1428 theywant = ifunit(ifr->ifr_name); 1429 if (theywant == NULL || theywant->if_bpf == NULL) 1430 return (ENXIO); 1431 1432 bp = theywant->if_bpf; 1433 1434 /* 1435 * Behavior here depends on the buffering model. If we're using 1436 * kernel memory buffers, then we can allocate them here. If we're 1437 * using zero-copy, then the user process must have registered 1438 * buffers by the time we get here. If not, return an error. 1439 * 1440 * XXXRW: There are locking issues here with multi-threaded use: what 1441 * if two threads try to set the interface at once? 1442 */ 1443 switch (d->bd_bufmode) { 1444 case BPF_BUFMODE_BUFFER: 1445 if (d->bd_sbuf == NULL) 1446 bpf_buffer_alloc(d); 1447 KASSERT(d->bd_sbuf != NULL, ("bpf_setif: bd_sbuf NULL")); 1448 break; 1449 1450 case BPF_BUFMODE_ZBUF: 1451 if (d->bd_sbuf == NULL) 1452 return (EINVAL); 1453 break; 1454 1455 default: 1456 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1457 } 1458 if (bp != d->bd_bif) { 1459 if (d->bd_bif) 1460 /* 1461 * Detach if attached to something else. 1462 */ 1463 bpf_detachd(d); 1464 1465 bpf_attachd(d, bp); 1466 } 1467 BPFD_LOCK(d); 1468 reset_d(d); 1469 BPFD_UNLOCK(d); 1470 return (0); 1471} 1472 1473/* 1474 * Support for select() and poll() system calls 1475 * 1476 * Return true iff the specific operation will not block indefinitely. 1477 * Otherwise, return false but make a note that a selwakeup() must be done. 1478 */ 1479static int 1480bpfpoll(struct cdev *dev, int events, struct thread *td) 1481{ 1482 struct bpf_d *d; 1483 int revents; 1484 1485 d = dev->si_drv1; 1486 if (d->bd_bif == NULL) 1487 return (ENXIO); 1488 1489 /* 1490 * Refresh PID associated with this descriptor. 1491 */ 1492 revents = events & (POLLOUT | POLLWRNORM); 1493 BPFD_LOCK(d); 1494 d->bd_pid = td->td_proc->p_pid; 1495 if (events & (POLLIN | POLLRDNORM)) { 1496 if (bpf_ready(d)) 1497 revents |= events & (POLLIN | POLLRDNORM); 1498 else { 1499 selrecord(td, &d->bd_sel); 1500 /* Start the read timeout if necessary. */ 1501 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1502 callout_reset(&d->bd_callout, d->bd_rtout, 1503 bpf_timed_out, d); 1504 d->bd_state = BPF_WAITING; 1505 } 1506 } 1507 } 1508 BPFD_UNLOCK(d); 1509 return (revents); 1510} 1511 1512/* 1513 * Support for kevent() system call. Register EVFILT_READ filters and 1514 * reject all others. 1515 */ 1516int 1517bpfkqfilter(struct cdev *dev, struct knote *kn) 1518{ 1519 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1520 1521 if (kn->kn_filter != EVFILT_READ) 1522 return (1); 1523 1524 /* 1525 * Refresh PID associated with this descriptor. 1526 */ 1527 BPFD_LOCK(d); 1528 d->bd_pid = curthread->td_proc->p_pid; 1529 kn->kn_fop = &bpfread_filtops; 1530 kn->kn_hook = d; 1531 knlist_add(&d->bd_sel.si_note, kn, 1); 1532 BPFD_UNLOCK(d); 1533 1534 return (0); 1535} 1536 1537static void 1538filt_bpfdetach(struct knote *kn) 1539{ 1540 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1541 1542 knlist_remove(&d->bd_sel.si_note, kn, 0); 1543} 1544 1545static int 1546filt_bpfread(struct knote *kn, long hint) 1547{ 1548 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1549 int ready; 1550 1551 BPFD_LOCK_ASSERT(d); 1552 ready = bpf_ready(d); 1553 if (ready) { 1554 kn->kn_data = d->bd_slen; 1555 if (d->bd_hbuf) 1556 kn->kn_data += d->bd_hlen; 1557 } 1558 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1559 callout_reset(&d->bd_callout, d->bd_rtout, 1560 bpf_timed_out, d); 1561 d->bd_state = BPF_WAITING; 1562 } 1563 1564 return (ready); 1565} 1566 1567/* 1568 * Incoming linkage from device drivers. Process the packet pkt, of length 1569 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1570 * by each process' filter, and if accepted, stashed into the corresponding 1571 * buffer. 1572 */ 1573void 1574bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1575{ 1576 struct bpf_d *d; 1577 u_int slen; 1578 int gottime; 1579 struct timeval tv; 1580 1581 gottime = 0; 1582 BPFIF_LOCK(bp); 1583 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1584 BPFD_LOCK(d); 1585 ++d->bd_rcount; 1586#ifdef BPF_JITTER 1587 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL) 1588 slen = (*(d->bd_bfilter->func))(pkt, pktlen, pktlen); 1589 else 1590#endif 1591 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1592 if (slen != 0) { 1593 d->bd_fcount++; 1594 if (!gottime) { 1595 microtime(&tv); 1596 gottime = 1; 1597 } 1598#ifdef MAC 1599 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1600#endif 1601 catchpacket(d, pkt, pktlen, slen, 1602 bpf_append_bytes, &tv); 1603 } 1604 BPFD_UNLOCK(d); 1605 } 1606 BPFIF_UNLOCK(bp); 1607} 1608 1609#define BPF_CHECK_DIRECTION(d, r, i) \ 1610 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 1611 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 1612 1613/* 1614 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1615 */ 1616void 1617bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1618{ 1619 struct bpf_d *d; 1620 u_int pktlen, slen; 1621 int gottime; 1622 struct timeval tv; 1623 1624 /* Skip outgoing duplicate packets. */ 1625 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 1626 m->m_flags &= ~M_PROMISC; 1627 return; 1628 } 1629 1630 gottime = 0; 1631 1632 pktlen = m_length(m, NULL); 1633 1634 BPFIF_LOCK(bp); 1635 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1636 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 1637 continue; 1638 BPFD_LOCK(d); 1639 ++d->bd_rcount; 1640#ifdef BPF_JITTER 1641 /* XXX We cannot handle multiple mbufs. */ 1642 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL && 1643 m->m_next == NULL) 1644 slen = (*(d->bd_bfilter->func))(mtod(m, u_char *), 1645 pktlen, pktlen); 1646 else 1647#endif 1648 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1649 if (slen != 0) { 1650 d->bd_fcount++; 1651 if (!gottime) { 1652 microtime(&tv); 1653 gottime = 1; 1654 } 1655#ifdef MAC 1656 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1657#endif 1658 catchpacket(d, (u_char *)m, pktlen, slen, 1659 bpf_append_mbuf, &tv); 1660 } 1661 BPFD_UNLOCK(d); 1662 } 1663 BPFIF_UNLOCK(bp); 1664} 1665 1666/* 1667 * Incoming linkage from device drivers, when packet is in 1668 * an mbuf chain and to be prepended by a contiguous header. 1669 */ 1670void 1671bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1672{ 1673 struct mbuf mb; 1674 struct bpf_d *d; 1675 u_int pktlen, slen; 1676 int gottime; 1677 struct timeval tv; 1678 1679 /* Skip outgoing duplicate packets. */ 1680 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 1681 m->m_flags &= ~M_PROMISC; 1682 return; 1683 } 1684 1685 gottime = 0; 1686 1687 pktlen = m_length(m, NULL); 1688 /* 1689 * Craft on-stack mbuf suitable for passing to bpf_filter. 1690 * Note that we cut corners here; we only setup what's 1691 * absolutely needed--this mbuf should never go anywhere else. 1692 */ 1693 mb.m_next = m; 1694 mb.m_data = data; 1695 mb.m_len = dlen; 1696 pktlen += dlen; 1697 1698 BPFIF_LOCK(bp); 1699 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1700 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 1701 continue; 1702 BPFD_LOCK(d); 1703 ++d->bd_rcount; 1704 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 1705 if (slen != 0) { 1706 d->bd_fcount++; 1707 if (!gottime) { 1708 microtime(&tv); 1709 gottime = 1; 1710 } 1711#ifdef MAC 1712 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1713#endif 1714 catchpacket(d, (u_char *)&mb, pktlen, slen, 1715 bpf_append_mbuf, &tv); 1716 } 1717 BPFD_UNLOCK(d); 1718 } 1719 BPFIF_UNLOCK(bp); 1720} 1721 1722#undef BPF_CHECK_DIRECTION 1723 1724/* 1725 * Move the packet data from interface memory (pkt) into the 1726 * store buffer. "cpfn" is the routine called to do the actual data 1727 * transfer. bcopy is passed in to copy contiguous chunks, while 1728 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 1729 * pkt is really an mbuf. 1730 */ 1731static void 1732catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1733 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 1734 struct timeval *tv) 1735{ 1736 struct bpf_hdr hdr; 1737 int totlen, curlen; 1738 int hdrlen = d->bd_bif->bif_hdrlen; 1739 int do_wakeup = 0; 1740 1741 BPFD_LOCK_ASSERT(d); 1742 1743 /* 1744 * Detect whether user space has released a buffer back to us, and if 1745 * so, move it from being a hold buffer to a free buffer. This may 1746 * not be the best place to do it (for example, we might only want to 1747 * run this check if we need the space), but for now it's a reliable 1748 * spot to do it. 1749 */ 1750 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 1751 d->bd_fbuf = d->bd_hbuf; 1752 d->bd_hbuf = NULL; 1753 d->bd_hlen = 0; 1754 bpf_buf_reclaimed(d); 1755 } 1756 1757 /* 1758 * Figure out how many bytes to move. If the packet is 1759 * greater or equal to the snapshot length, transfer that 1760 * much. Otherwise, transfer the whole packet (unless 1761 * we hit the buffer size limit). 1762 */ 1763 totlen = hdrlen + min(snaplen, pktlen); 1764 if (totlen > d->bd_bufsize) 1765 totlen = d->bd_bufsize; 1766 1767 /* 1768 * Round up the end of the previous packet to the next longword. 1769 * 1770 * Drop the packet if there's no room and no hope of room 1771 * If the packet would overflow the storage buffer or the storage 1772 * buffer is considered immutable by the buffer model, try to rotate 1773 * the buffer and wakeup pending processes. 1774 */ 1775 curlen = BPF_WORDALIGN(d->bd_slen); 1776 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 1777 if (d->bd_fbuf == NULL) { 1778 /* 1779 * There's no room in the store buffer, and no 1780 * prospect of room, so drop the packet. Notify the 1781 * buffer model. 1782 */ 1783 bpf_buffull(d); 1784 ++d->bd_dcount; 1785 return; 1786 } 1787 ROTATE_BUFFERS(d); 1788 do_wakeup = 1; 1789 curlen = 0; 1790 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1791 /* 1792 * Immediate mode is set, or the read timeout has already 1793 * expired during a select call. A packet arrived, so the 1794 * reader should be woken up. 1795 */ 1796 do_wakeup = 1; 1797 1798 /* 1799 * Append the bpf header. Note we append the actual header size, but 1800 * move forward the length of the header plus padding. 1801 */ 1802 bzero(&hdr, sizeof(hdr)); 1803 hdr.bh_tstamp = *tv; 1804 hdr.bh_datalen = pktlen; 1805 hdr.bh_hdrlen = hdrlen; 1806 hdr.bh_caplen = totlen - hdrlen; 1807 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 1808 1809 /* 1810 * Copy the packet data into the store buffer and update its length. 1811 */ 1812 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, hdr.bh_caplen); 1813 d->bd_slen = curlen + totlen; 1814 1815 if (do_wakeup) 1816 bpf_wakeup(d); 1817} 1818 1819/* 1820 * Free buffers currently in use by a descriptor. 1821 * Called on close. 1822 */ 1823static void 1824bpf_freed(struct bpf_d *d) 1825{ 1826 1827 /* 1828 * We don't need to lock out interrupts since this descriptor has 1829 * been detached from its interface and it yet hasn't been marked 1830 * free. 1831 */ 1832 bpf_free(d); 1833 if (d->bd_rfilter) { 1834 free((caddr_t)d->bd_rfilter, M_BPF); 1835#ifdef BPF_JITTER 1836 bpf_destroy_jit_filter(d->bd_bfilter); 1837#endif 1838 } 1839 if (d->bd_wfilter) 1840 free((caddr_t)d->bd_wfilter, M_BPF); 1841 mtx_destroy(&d->bd_mtx); 1842} 1843 1844/* 1845 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1846 * fixed size of the link header (variable length headers not yet supported). 1847 */ 1848void 1849bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1850{ 1851 1852 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1853} 1854 1855/* 1856 * Attach an interface to bpf. ifp is a pointer to the structure 1857 * defining the interface to be attached, dlt is the link layer type, 1858 * and hdrlen is the fixed size of the link header (variable length 1859 * headers are not yet supporrted). 1860 */ 1861void 1862bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1863{ 1864 struct bpf_if *bp; 1865 1866 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1867 if (bp == NULL) 1868 panic("bpfattach"); 1869 1870 LIST_INIT(&bp->bif_dlist); 1871 bp->bif_ifp = ifp; 1872 bp->bif_dlt = dlt; 1873 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1874 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 1875 *driverp = bp; 1876 1877 mtx_lock(&bpf_mtx); 1878 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1879 mtx_unlock(&bpf_mtx); 1880 1881 /* 1882 * Compute the length of the bpf header. This is not necessarily 1883 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1884 * that the network layer header begins on a longword boundary (for 1885 * performance reasons and to alleviate alignment restrictions). 1886 */ 1887 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1888 1889 if (bootverbose) 1890 if_printf(ifp, "bpf attached\n"); 1891} 1892 1893/* 1894 * Detach bpf from an interface. This involves detaching each descriptor 1895 * associated with the interface, and leaving bd_bif NULL. Notify each 1896 * descriptor as it's detached so that any sleepers wake up and get 1897 * ENXIO. 1898 */ 1899void 1900bpfdetach(struct ifnet *ifp) 1901{ 1902 struct bpf_if *bp; 1903 struct bpf_d *d; 1904 1905 /* Locate BPF interface information */ 1906 mtx_lock(&bpf_mtx); 1907 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1908 if (ifp == bp->bif_ifp) 1909 break; 1910 } 1911 1912 /* Interface wasn't attached */ 1913 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1914 mtx_unlock(&bpf_mtx); 1915 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1916 return; 1917 } 1918 1919 LIST_REMOVE(bp, bif_next); 1920 mtx_unlock(&bpf_mtx); 1921 1922 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1923 bpf_detachd(d); 1924 BPFD_LOCK(d); 1925 bpf_wakeup(d); 1926 BPFD_UNLOCK(d); 1927 } 1928 1929 mtx_destroy(&bp->bif_mtx); 1930 free(bp, M_BPF); 1931} 1932 1933/* 1934 * Get a list of available data link type of the interface. 1935 */ 1936static int 1937bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1938{ 1939 int n, error; 1940 struct ifnet *ifp; 1941 struct bpf_if *bp; 1942 1943 ifp = d->bd_bif->bif_ifp; 1944 n = 0; 1945 error = 0; 1946 mtx_lock(&bpf_mtx); 1947 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1948 if (bp->bif_ifp != ifp) 1949 continue; 1950 if (bfl->bfl_list != NULL) { 1951 if (n >= bfl->bfl_len) { 1952 mtx_unlock(&bpf_mtx); 1953 return (ENOMEM); 1954 } 1955 error = copyout(&bp->bif_dlt, 1956 bfl->bfl_list + n, sizeof(u_int)); 1957 } 1958 n++; 1959 } 1960 mtx_unlock(&bpf_mtx); 1961 bfl->bfl_len = n; 1962 return (error); 1963} 1964 1965/* 1966 * Set the data link type of a BPF instance. 1967 */ 1968static int 1969bpf_setdlt(struct bpf_d *d, u_int dlt) 1970{ 1971 int error, opromisc; 1972 struct ifnet *ifp; 1973 struct bpf_if *bp; 1974 1975 if (d->bd_bif->bif_dlt == dlt) 1976 return (0); 1977 ifp = d->bd_bif->bif_ifp; 1978 mtx_lock(&bpf_mtx); 1979 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1980 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1981 break; 1982 } 1983 mtx_unlock(&bpf_mtx); 1984 if (bp != NULL) { 1985 opromisc = d->bd_promisc; 1986 bpf_detachd(d); 1987 bpf_attachd(d, bp); 1988 BPFD_LOCK(d); 1989 reset_d(d); 1990 BPFD_UNLOCK(d); 1991 if (opromisc) { 1992 error = ifpromisc(bp->bif_ifp, 1); 1993 if (error) 1994 if_printf(bp->bif_ifp, 1995 "bpf_setdlt: ifpromisc failed (%d)\n", 1996 error); 1997 else 1998 d->bd_promisc = 1; 1999 } 2000 } 2001 return (bp == NULL ? EINVAL : 0); 2002} 2003 2004static void 2005bpf_clone(void *arg, struct ucred *cred, char *name, int namelen, 2006 struct cdev **dev) 2007{ 2008 int u; 2009 2010 if (*dev != NULL) 2011 return; 2012 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 2013 return; 2014 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 2015 "bpf%d", u); 2016 dev_ref(*dev); 2017 (*dev)->si_flags |= SI_CHEAPCLONE; 2018 return; 2019} 2020 2021static void 2022bpf_drvinit(void *unused) 2023{ 2024 2025 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2026 LIST_INIT(&bpf_iflist); 2027 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 2028} 2029 2030static void 2031bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2032{ 2033 2034 bzero(d, sizeof(*d)); 2035 BPFD_LOCK_ASSERT(bd); 2036 d->bd_structsize = sizeof(*d); 2037 d->bd_immediate = bd->bd_immediate; 2038 d->bd_promisc = bd->bd_promisc; 2039 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2040 d->bd_direction = bd->bd_direction; 2041 d->bd_feedback = bd->bd_feedback; 2042 d->bd_async = bd->bd_async; 2043 d->bd_rcount = bd->bd_rcount; 2044 d->bd_dcount = bd->bd_dcount; 2045 d->bd_fcount = bd->bd_fcount; 2046 d->bd_sig = bd->bd_sig; 2047 d->bd_slen = bd->bd_slen; 2048 d->bd_hlen = bd->bd_hlen; 2049 d->bd_bufsize = bd->bd_bufsize; 2050 d->bd_pid = bd->bd_pid; 2051 strlcpy(d->bd_ifname, 2052 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2053 d->bd_locked = bd->bd_locked; 2054 d->bd_wcount = bd->bd_wcount; 2055 d->bd_wdcount = bd->bd_wdcount; 2056 d->bd_wfcount = bd->bd_wfcount; 2057 d->bd_zcopy = bd->bd_zcopy; 2058 d->bd_bufmode = bd->bd_bufmode; 2059} 2060 2061static int 2062bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2063{ 2064 struct xbpf_d *xbdbuf, *xbd; 2065 int index, error; 2066 struct bpf_if *bp; 2067 struct bpf_d *bd; 2068 2069 /* 2070 * XXX This is not technically correct. It is possible for non 2071 * privileged users to open bpf devices. It would make sense 2072 * if the users who opened the devices were able to retrieve 2073 * the statistics for them, too. 2074 */ 2075 error = priv_check(req->td, PRIV_NET_BPF); 2076 if (error) 2077 return (error); 2078 if (req->oldptr == NULL) 2079 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2080 if (bpf_bpfd_cnt == 0) 2081 return (SYSCTL_OUT(req, 0, 0)); 2082 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2083 mtx_lock(&bpf_mtx); 2084 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2085 mtx_unlock(&bpf_mtx); 2086 free(xbdbuf, M_BPF); 2087 return (ENOMEM); 2088 } 2089 index = 0; 2090 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2091 BPFIF_LOCK(bp); 2092 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2093 xbd = &xbdbuf[index++]; 2094 BPFD_LOCK(bd); 2095 bpfstats_fill_xbpf(xbd, bd); 2096 BPFD_UNLOCK(bd); 2097 } 2098 BPFIF_UNLOCK(bp); 2099 } 2100 mtx_unlock(&bpf_mtx); 2101 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2102 free(xbdbuf, M_BPF); 2103 return (error); 2104} 2105 2106SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2107 2108#else /* !DEV_BPF && !NETGRAPH_BPF */ 2109/* 2110 * NOP stubs to allow bpf-using drivers to load and function. 2111 * 2112 * A 'better' implementation would allow the core bpf functionality 2113 * to be loaded at runtime. 2114 */ 2115static struct bpf_if bp_null; 2116 2117void 2118bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2119{ 2120} 2121 2122void 2123bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2124{ 2125} 2126 2127void 2128bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2129{ 2130} 2131 2132void 2133bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2134{ 2135 2136 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2137} 2138 2139void 2140bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2141{ 2142 2143 *driverp = &bp_null; 2144} 2145 2146void 2147bpfdetach(struct ifnet *ifp) 2148{ 2149} 2150 2151u_int 2152bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 2153{ 2154 return -1; /* "no filter" behaviour */ 2155} 2156 2157int 2158bpf_validate(const struct bpf_insn *f, int len) 2159{ 2160 return 0; /* false */ 2161} 2162 2163#endif /* !DEV_BPF && !NETGRAPH_BPF */ 2164