bpf.c revision 192763
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 192763 2009-05-25 16:34:35Z sam $"); 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#include <sys/vimage.h> 60 61#include <sys/event.h> 62#include <sys/file.h> 63#include <sys/poll.h> 64#include <sys/proc.h> 65 66#include <sys/socket.h> 67 68#include <net/if.h> 69#include <net/bpf.h> 70#include <net/bpf_buffer.h> 71#ifdef BPF_JITTER 72#include <net/bpf_jitter.h> 73#endif 74#include <net/bpf_zerocopy.h> 75#include <net/bpfdesc.h> 76 77#include <netinet/in.h> 78#include <netinet/if_ether.h> 79#include <sys/kernel.h> 80#include <sys/sysctl.h> 81 82#include <net80211/ieee80211_freebsd.h> 83 84#include <security/mac/mac_framework.h> 85 86MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 87 88#if defined(DEV_BPF) || defined(NETGRAPH_BPF) 89 90#define PRINET 26 /* interruptible */ 91 92/* 93 * bpf_iflist is a list of BPF interface structures, each corresponding to a 94 * specific DLT. The same network interface might have several BPF interface 95 * structures registered by different layers in the stack (i.e., 802.11 96 * frames, ethernet frames, etc). 97 */ 98static LIST_HEAD(, bpf_if) bpf_iflist; 99static struct mtx bpf_mtx; /* bpf global lock */ 100static int bpf_bpfd_cnt; 101 102static void bpf_attachd(struct bpf_d *, struct bpf_if *); 103static void bpf_detachd(struct bpf_d *); 104static void bpf_freed(struct bpf_d *); 105static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 106 struct sockaddr *, int *, struct bpf_insn *); 107static int bpf_setif(struct bpf_d *, struct ifreq *); 108static void bpf_timed_out(void *); 109static __inline void 110 bpf_wakeup(struct bpf_d *); 111static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 112 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 113 struct timeval *); 114static void reset_d(struct bpf_d *); 115static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 116static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 117static int bpf_setdlt(struct bpf_d *, u_int); 118static void filt_bpfdetach(struct knote *); 119static int filt_bpfread(struct knote *, long); 120static void bpf_drvinit(void *); 121static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 122 123SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 124int 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_MPSAFE | CTLFLAG_RW, 131 bpf_stats_sysctl, "bpf statistics portal"); 132 133static d_open_t bpfopen; 134static d_read_t bpfread; 135static d_write_t bpfwrite; 136static d_ioctl_t bpfioctl; 137static d_poll_t bpfpoll; 138static d_kqfilter_t bpfkqfilter; 139 140static struct cdevsw bpf_cdevsw = { 141 .d_version = D_VERSION, 142 .d_open = bpfopen, 143 .d_read = bpfread, 144 .d_write = bpfwrite, 145 .d_ioctl = bpfioctl, 146 .d_poll = bpfpoll, 147 .d_name = "bpf", 148 .d_kqfilter = bpfkqfilter, 149}; 150 151static struct filterops bpfread_filtops = 152 { 1, NULL, filt_bpfdetach, filt_bpfread }; 153 154/* 155 * Wrapper functions for various buffering methods. If the set of buffer 156 * modes expands, we will probably want to introduce a switch data structure 157 * similar to protosw, et. 158 */ 159static void 160bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 161 u_int len) 162{ 163 164 BPFD_LOCK_ASSERT(d); 165 166 switch (d->bd_bufmode) { 167 case BPF_BUFMODE_BUFFER: 168 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 169 170 case BPF_BUFMODE_ZBUF: 171 d->bd_zcopy++; 172 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 173 174 default: 175 panic("bpf_buf_append_bytes"); 176 } 177} 178 179static void 180bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 181 u_int len) 182{ 183 184 BPFD_LOCK_ASSERT(d); 185 186 switch (d->bd_bufmode) { 187 case BPF_BUFMODE_BUFFER: 188 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 189 190 case BPF_BUFMODE_ZBUF: 191 d->bd_zcopy++; 192 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 193 194 default: 195 panic("bpf_buf_append_mbuf"); 196 } 197} 198 199/* 200 * This function gets called when the free buffer is re-assigned. 201 */ 202static void 203bpf_buf_reclaimed(struct bpf_d *d) 204{ 205 206 BPFD_LOCK_ASSERT(d); 207 208 switch (d->bd_bufmode) { 209 case BPF_BUFMODE_BUFFER: 210 return; 211 212 case BPF_BUFMODE_ZBUF: 213 bpf_zerocopy_buf_reclaimed(d); 214 return; 215 216 default: 217 panic("bpf_buf_reclaimed"); 218 } 219} 220 221/* 222 * If the buffer mechanism has a way to decide that a held buffer can be made 223 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 224 * returned if the buffer can be discarded, (0) is returned if it cannot. 225 */ 226static int 227bpf_canfreebuf(struct bpf_d *d) 228{ 229 230 BPFD_LOCK_ASSERT(d); 231 232 switch (d->bd_bufmode) { 233 case BPF_BUFMODE_ZBUF: 234 return (bpf_zerocopy_canfreebuf(d)); 235 } 236 return (0); 237} 238 239/* 240 * Allow the buffer model to indicate that the current store buffer is 241 * immutable, regardless of the appearance of space. Return (1) if the 242 * buffer is writable, and (0) if not. 243 */ 244static int 245bpf_canwritebuf(struct bpf_d *d) 246{ 247 248 BPFD_LOCK_ASSERT(d); 249 250 switch (d->bd_bufmode) { 251 case BPF_BUFMODE_ZBUF: 252 return (bpf_zerocopy_canwritebuf(d)); 253 } 254 return (1); 255} 256 257/* 258 * Notify buffer model that an attempt to write to the store buffer has 259 * resulted in a dropped packet, in which case the buffer may be considered 260 * full. 261 */ 262static void 263bpf_buffull(struct bpf_d *d) 264{ 265 266 BPFD_LOCK_ASSERT(d); 267 268 switch (d->bd_bufmode) { 269 case BPF_BUFMODE_ZBUF: 270 bpf_zerocopy_buffull(d); 271 break; 272 } 273} 274 275/* 276 * Notify the buffer model that a buffer has moved into the hold position. 277 */ 278void 279bpf_bufheld(struct bpf_d *d) 280{ 281 282 BPFD_LOCK_ASSERT(d); 283 284 switch (d->bd_bufmode) { 285 case BPF_BUFMODE_ZBUF: 286 bpf_zerocopy_bufheld(d); 287 break; 288 } 289} 290 291static void 292bpf_free(struct bpf_d *d) 293{ 294 295 switch (d->bd_bufmode) { 296 case BPF_BUFMODE_BUFFER: 297 return (bpf_buffer_free(d)); 298 299 case BPF_BUFMODE_ZBUF: 300 return (bpf_zerocopy_free(d)); 301 302 default: 303 panic("bpf_buf_free"); 304 } 305} 306 307static int 308bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 309{ 310 311 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 312 return (EOPNOTSUPP); 313 return (bpf_buffer_uiomove(d, buf, len, uio)); 314} 315 316static int 317bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 318{ 319 320 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 321 return (EOPNOTSUPP); 322 return (bpf_buffer_ioctl_sblen(d, i)); 323} 324 325static int 326bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 327{ 328 329 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 330 return (EOPNOTSUPP); 331 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 332} 333 334static int 335bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 336{ 337 338 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 339 return (EOPNOTSUPP); 340 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 341} 342 343static int 344bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 345{ 346 347 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 348 return (EOPNOTSUPP); 349 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 350} 351 352/* 353 * General BPF functions. 354 */ 355static int 356bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 357 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) 358{ 359 const struct ieee80211_bpf_params *p; 360 struct ether_header *eh; 361 struct mbuf *m; 362 int error; 363 int len; 364 int hlen; 365 int slen; 366 367 /* 368 * Build a sockaddr based on the data link layer type. 369 * We do this at this level because the ethernet header 370 * is copied directly into the data field of the sockaddr. 371 * In the case of SLIP, there is no header and the packet 372 * is forwarded as is. 373 * Also, we are careful to leave room at the front of the mbuf 374 * for the link level header. 375 */ 376 switch (linktype) { 377 378 case DLT_SLIP: 379 sockp->sa_family = AF_INET; 380 hlen = 0; 381 break; 382 383 case DLT_EN10MB: 384 sockp->sa_family = AF_UNSPEC; 385 /* XXX Would MAXLINKHDR be better? */ 386 hlen = ETHER_HDR_LEN; 387 break; 388 389 case DLT_FDDI: 390 sockp->sa_family = AF_IMPLINK; 391 hlen = 0; 392 break; 393 394 case DLT_RAW: 395 sockp->sa_family = AF_UNSPEC; 396 hlen = 0; 397 break; 398 399 case DLT_NULL: 400 /* 401 * null interface types require a 4 byte pseudo header which 402 * corresponds to the address family of the packet. 403 */ 404 sockp->sa_family = AF_UNSPEC; 405 hlen = 4; 406 break; 407 408 case DLT_ATM_RFC1483: 409 /* 410 * en atm driver requires 4-byte atm pseudo header. 411 * though it isn't standard, vpi:vci needs to be 412 * specified anyway. 413 */ 414 sockp->sa_family = AF_UNSPEC; 415 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 416 break; 417 418 case DLT_PPP: 419 sockp->sa_family = AF_UNSPEC; 420 hlen = 4; /* This should match PPP_HDRLEN */ 421 break; 422 423 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 424 sockp->sa_family = AF_IEEE80211; 425 hlen = 0; 426 break; 427 428 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 429 sockp->sa_family = AF_IEEE80211; 430 sockp->sa_len = 12; /* XXX != 0 */ 431 hlen = sizeof(struct ieee80211_bpf_params); 432 break; 433 434 default: 435 return (EIO); 436 } 437 438 len = uio->uio_resid; 439 440 if (len - hlen > ifp->if_mtu) 441 return (EMSGSIZE); 442 443 if ((unsigned)len > MJUM16BYTES) 444 return (EIO); 445 446 if (len <= MHLEN) 447 MGETHDR(m, M_WAIT, MT_DATA); 448 else if (len <= MCLBYTES) 449 m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR); 450 else 451 m = m_getjcl(M_WAIT, MT_DATA, M_PKTHDR, 452#if (MJUMPAGESIZE > MCLBYTES) 453 len <= MJUMPAGESIZE ? MJUMPAGESIZE : 454#endif 455 (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES)); 456 m->m_pkthdr.len = m->m_len = len; 457 m->m_pkthdr.rcvif = NULL; 458 *mp = m; 459 460 if (m->m_len < hlen) { 461 error = EPERM; 462 goto bad; 463 } 464 465 error = uiomove(mtod(m, u_char *), len, uio); 466 if (error) 467 goto bad; 468 469 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 470 if (slen == 0) { 471 error = EPERM; 472 goto bad; 473 } 474 475 /* Check for multicast destination */ 476 switch (linktype) { 477 case DLT_EN10MB: 478 eh = mtod(m, struct ether_header *); 479 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 480 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 481 ETHER_ADDR_LEN) == 0) 482 m->m_flags |= M_BCAST; 483 else 484 m->m_flags |= M_MCAST; 485 } 486 break; 487 } 488 489 /* 490 * Make room for link header, and copy it to sockaddr 491 */ 492 if (hlen != 0) { 493 if (sockp->sa_family == AF_IEEE80211) { 494 /* 495 * Collect true length from the parameter header 496 * NB: sockp is known to be zero'd so if we do a 497 * short copy unspecified parameters will be 498 * zero. 499 * NB: packet may not be aligned after stripping 500 * bpf params 501 * XXX check ibp_vers 502 */ 503 p = mtod(m, const struct ieee80211_bpf_params *); 504 hlen = p->ibp_len; 505 if (hlen > sizeof(sockp->sa_data)) { 506 error = EINVAL; 507 goto bad; 508 } 509 } 510 bcopy(m->m_data, sockp->sa_data, hlen); 511 } 512 *hdrlen = hlen; 513 514 return (0); 515bad: 516 m_freem(m); 517 return (error); 518} 519 520/* 521 * Attach file to the bpf interface, i.e. make d listen on bp. 522 */ 523static void 524bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 525{ 526 /* 527 * Point d at bp, and add d to the interface's list of listeners. 528 * Finally, point the driver's bpf cookie at the interface so 529 * it will divert packets to bpf. 530 */ 531 BPFIF_LOCK(bp); 532 d->bd_bif = bp; 533 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 534 535 bpf_bpfd_cnt++; 536 BPFIF_UNLOCK(bp); 537 538 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 539} 540 541/* 542 * Detach a file from its interface. 543 */ 544static void 545bpf_detachd(struct bpf_d *d) 546{ 547 int error; 548 struct bpf_if *bp; 549 struct ifnet *ifp; 550 551 bp = d->bd_bif; 552 BPFIF_LOCK(bp); 553 BPFD_LOCK(d); 554 ifp = d->bd_bif->bif_ifp; 555 556 /* 557 * Remove d from the interface's descriptor list. 558 */ 559 LIST_REMOVE(d, bd_next); 560 561 bpf_bpfd_cnt--; 562 d->bd_bif = NULL; 563 BPFD_UNLOCK(d); 564 BPFIF_UNLOCK(bp); 565 566 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 567 568 /* 569 * Check if this descriptor had requested promiscuous mode. 570 * If so, turn it off. 571 */ 572 if (d->bd_promisc) { 573 d->bd_promisc = 0; 574 CURVNET_SET(ifp->if_vnet); 575 error = ifpromisc(ifp, 0); 576 CURVNET_RESTORE(); 577 if (error != 0 && error != ENXIO) { 578 /* 579 * ENXIO can happen if a pccard is unplugged 580 * Something is really wrong if we were able to put 581 * the driver into promiscuous mode, but can't 582 * take it out. 583 */ 584 if_printf(bp->bif_ifp, 585 "bpf_detach: ifpromisc failed (%d)\n", error); 586 } 587 } 588} 589 590/* 591 * Close the descriptor by detaching it from its interface, 592 * deallocating its buffers, and marking it free. 593 */ 594static void 595bpf_dtor(void *data) 596{ 597 struct bpf_d *d = data; 598 599 BPFD_LOCK(d); 600 if (d->bd_state == BPF_WAITING) 601 callout_stop(&d->bd_callout); 602 d->bd_state = BPF_IDLE; 603 BPFD_UNLOCK(d); 604 funsetown(&d->bd_sigio); 605 mtx_lock(&bpf_mtx); 606 if (d->bd_bif) 607 bpf_detachd(d); 608 mtx_unlock(&bpf_mtx); 609 selwakeuppri(&d->bd_sel, PRINET); 610#ifdef MAC 611 mac_bpfdesc_destroy(d); 612#endif /* MAC */ 613 knlist_destroy(&d->bd_sel.si_note); 614 bpf_freed(d); 615 free(d, M_BPF); 616} 617 618/* 619 * Open ethernet device. Returns ENXIO for illegal minor device number, 620 * EBUSY if file is open by another process. 621 */ 622/* ARGSUSED */ 623static int 624bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 625{ 626 struct bpf_d *d; 627 int error; 628 629 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 630 error = devfs_set_cdevpriv(d, bpf_dtor); 631 if (error != 0) { 632 free(d, M_BPF); 633 return (error); 634 } 635 636 /* 637 * For historical reasons, perform a one-time initialization call to 638 * the buffer routines, even though we're not yet committed to a 639 * particular buffer method. 640 */ 641 bpf_buffer_init(d); 642 d->bd_bufmode = BPF_BUFMODE_BUFFER; 643 d->bd_sig = SIGIO; 644 d->bd_direction = BPF_D_INOUT; 645 d->bd_pid = td->td_proc->p_pid; 646#ifdef MAC 647 mac_bpfdesc_init(d); 648 mac_bpfdesc_create(td->td_ucred, d); 649#endif 650 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 651 callout_init(&d->bd_callout, CALLOUT_MPSAFE); 652 knlist_init(&d->bd_sel.si_note, &d->bd_mtx, NULL, NULL, NULL); 653 654 return (0); 655} 656 657/* 658 * bpfread - read next chunk of packets from buffers 659 */ 660static int 661bpfread(struct cdev *dev, struct uio *uio, int ioflag) 662{ 663 struct bpf_d *d; 664 int timed_out; 665 int error; 666 667 error = devfs_get_cdevpriv((void **)&d); 668 if (error != 0) 669 return (error); 670 671 /* 672 * Restrict application to use a buffer the same size as 673 * as kernel buffers. 674 */ 675 if (uio->uio_resid != d->bd_bufsize) 676 return (EINVAL); 677 678 BPFD_LOCK(d); 679 d->bd_pid = curthread->td_proc->p_pid; 680 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 681 BPFD_UNLOCK(d); 682 return (EOPNOTSUPP); 683 } 684 if (d->bd_state == BPF_WAITING) 685 callout_stop(&d->bd_callout); 686 timed_out = (d->bd_state == BPF_TIMED_OUT); 687 d->bd_state = BPF_IDLE; 688 /* 689 * If the hold buffer is empty, then do a timed sleep, which 690 * ends when the timeout expires or when enough packets 691 * have arrived to fill the store buffer. 692 */ 693 while (d->bd_hbuf == NULL) { 694 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 695 /* 696 * A packet(s) either arrived since the previous 697 * read or arrived while we were asleep. 698 * Rotate the buffers and return what's here. 699 */ 700 ROTATE_BUFFERS(d); 701 break; 702 } 703 704 /* 705 * No data is available, check to see if the bpf device 706 * is still pointed at a real interface. If not, return 707 * ENXIO so that the userland process knows to rebind 708 * it before using it again. 709 */ 710 if (d->bd_bif == NULL) { 711 BPFD_UNLOCK(d); 712 return (ENXIO); 713 } 714 715 if (ioflag & O_NONBLOCK) { 716 BPFD_UNLOCK(d); 717 return (EWOULDBLOCK); 718 } 719 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 720 "bpf", d->bd_rtout); 721 if (error == EINTR || error == ERESTART) { 722 BPFD_UNLOCK(d); 723 return (error); 724 } 725 if (error == EWOULDBLOCK) { 726 /* 727 * On a timeout, return what's in the buffer, 728 * which may be nothing. If there is something 729 * in the store buffer, we can rotate the buffers. 730 */ 731 if (d->bd_hbuf) 732 /* 733 * We filled up the buffer in between 734 * getting the timeout and arriving 735 * here, so we don't need to rotate. 736 */ 737 break; 738 739 if (d->bd_slen == 0) { 740 BPFD_UNLOCK(d); 741 return (0); 742 } 743 ROTATE_BUFFERS(d); 744 break; 745 } 746 } 747 /* 748 * At this point, we know we have something in the hold slot. 749 */ 750 BPFD_UNLOCK(d); 751 752 /* 753 * Move data from hold buffer into user space. 754 * We know the entire buffer is transferred since 755 * we checked above that the read buffer is bpf_bufsize bytes. 756 * 757 * XXXRW: More synchronization needed here: what if a second thread 758 * issues a read on the same fd at the same time? Don't want this 759 * getting invalidated. 760 */ 761 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 762 763 BPFD_LOCK(d); 764 d->bd_fbuf = d->bd_hbuf; 765 d->bd_hbuf = NULL; 766 d->bd_hlen = 0; 767 bpf_buf_reclaimed(d); 768 BPFD_UNLOCK(d); 769 770 return (error); 771} 772 773/* 774 * If there are processes sleeping on this descriptor, wake them up. 775 */ 776static __inline void 777bpf_wakeup(struct bpf_d *d) 778{ 779 780 BPFD_LOCK_ASSERT(d); 781 if (d->bd_state == BPF_WAITING) { 782 callout_stop(&d->bd_callout); 783 d->bd_state = BPF_IDLE; 784 } 785 wakeup(d); 786 if (d->bd_async && d->bd_sig && d->bd_sigio) 787 pgsigio(&d->bd_sigio, d->bd_sig, 0); 788 789 selwakeuppri(&d->bd_sel, PRINET); 790 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 791} 792 793static void 794bpf_timed_out(void *arg) 795{ 796 struct bpf_d *d = (struct bpf_d *)arg; 797 798 BPFD_LOCK(d); 799 if (d->bd_state == BPF_WAITING) { 800 d->bd_state = BPF_TIMED_OUT; 801 if (d->bd_slen != 0) 802 bpf_wakeup(d); 803 } 804 BPFD_UNLOCK(d); 805} 806 807static int 808bpf_ready(struct bpf_d *d) 809{ 810 811 BPFD_LOCK_ASSERT(d); 812 813 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 814 return (1); 815 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 816 d->bd_slen != 0) 817 return (1); 818 return (0); 819} 820 821static int 822bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 823{ 824 struct bpf_d *d; 825 struct ifnet *ifp; 826 struct mbuf *m, *mc; 827 struct sockaddr dst; 828 int error, hlen; 829 830 error = devfs_get_cdevpriv((void **)&d); 831 if (error != 0) 832 return (error); 833 834 d->bd_pid = curthread->td_proc->p_pid; 835 d->bd_wcount++; 836 if (d->bd_bif == NULL) { 837 d->bd_wdcount++; 838 return (ENXIO); 839 } 840 841 ifp = d->bd_bif->bif_ifp; 842 843 if ((ifp->if_flags & IFF_UP) == 0) { 844 d->bd_wdcount++; 845 return (ENETDOWN); 846 } 847 848 if (uio->uio_resid == 0) { 849 d->bd_wdcount++; 850 return (0); 851 } 852 853 bzero(&dst, sizeof(dst)); 854 m = NULL; 855 hlen = 0; 856 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 857 &m, &dst, &hlen, d->bd_wfilter); 858 if (error) { 859 d->bd_wdcount++; 860 return (error); 861 } 862 d->bd_wfcount++; 863 if (d->bd_hdrcmplt) 864 dst.sa_family = pseudo_AF_HDRCMPLT; 865 866 if (d->bd_feedback) { 867 mc = m_dup(m, M_DONTWAIT); 868 if (mc != NULL) 869 mc->m_pkthdr.rcvif = ifp; 870 /* Set M_PROMISC for outgoing packets to be discarded. */ 871 if (d->bd_direction == BPF_D_INOUT) 872 m->m_flags |= M_PROMISC; 873 } else 874 mc = NULL; 875 876 m->m_pkthdr.len -= hlen; 877 m->m_len -= hlen; 878 m->m_data += hlen; /* XXX */ 879 880 CURVNET_SET(ifp->if_vnet); 881#ifdef MAC 882 BPFD_LOCK(d); 883 mac_bpfdesc_create_mbuf(d, m); 884 if (mc != NULL) 885 mac_bpfdesc_create_mbuf(d, mc); 886 BPFD_UNLOCK(d); 887#endif 888 889 error = (*ifp->if_output)(ifp, m, &dst, NULL); 890 if (error) 891 d->bd_wdcount++; 892 893 if (mc != NULL) { 894 if (error == 0) 895 (*ifp->if_input)(ifp, mc); 896 else 897 m_freem(mc); 898 } 899 CURVNET_RESTORE(); 900 901 return (error); 902} 903 904/* 905 * Reset a descriptor by flushing its packet buffer and clearing the receive 906 * and drop counts. This is doable for kernel-only buffers, but with 907 * zero-copy buffers, we can't write to (or rotate) buffers that are 908 * currently owned by userspace. It would be nice if we could encapsulate 909 * this logic in the buffer code rather than here. 910 */ 911static void 912reset_d(struct bpf_d *d) 913{ 914 915 mtx_assert(&d->bd_mtx, MA_OWNED); 916 917 if ((d->bd_hbuf != NULL) && 918 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 919 /* Free the hold buffer. */ 920 d->bd_fbuf = d->bd_hbuf; 921 d->bd_hbuf = NULL; 922 d->bd_hlen = 0; 923 bpf_buf_reclaimed(d); 924 } 925 if (bpf_canwritebuf(d)) 926 d->bd_slen = 0; 927 d->bd_rcount = 0; 928 d->bd_dcount = 0; 929 d->bd_fcount = 0; 930 d->bd_wcount = 0; 931 d->bd_wfcount = 0; 932 d->bd_wdcount = 0; 933 d->bd_zcopy = 0; 934} 935 936/* 937 * FIONREAD Check for read packet available. 938 * SIOCGIFADDR Get interface address - convenient hook to driver. 939 * BIOCGBLEN Get buffer len [for read()]. 940 * BIOCSETF Set read filter. 941 * BIOCSETFNR Set read filter without resetting descriptor. 942 * BIOCSETWF Set write filter. 943 * BIOCFLUSH Flush read packet buffer. 944 * BIOCPROMISC Put interface into promiscuous mode. 945 * BIOCGDLT Get link layer type. 946 * BIOCGETIF Get interface name. 947 * BIOCSETIF Set interface. 948 * BIOCSRTIMEOUT Set read timeout. 949 * BIOCGRTIMEOUT Get read timeout. 950 * BIOCGSTATS Get packet stats. 951 * BIOCIMMEDIATE Set immediate mode. 952 * BIOCVERSION Get filter language version. 953 * BIOCGHDRCMPLT Get "header already complete" flag 954 * BIOCSHDRCMPLT Set "header already complete" flag 955 * BIOCGDIRECTION Get packet direction flag 956 * BIOCSDIRECTION Set packet direction flag 957 * BIOCLOCK Set "locked" flag 958 * BIOCFEEDBACK Set packet feedback mode. 959 * BIOCSETZBUF Set current zero-copy buffer locations. 960 * BIOCGETZMAX Get maximum zero-copy buffer size. 961 * BIOCROTZBUF Force rotation of zero-copy buffer 962 * BIOCSETBUFMODE Set buffer mode. 963 * BIOCGETBUFMODE Get current buffer mode. 964 */ 965/* ARGSUSED */ 966static int 967bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 968 struct thread *td) 969{ 970 struct bpf_d *d; 971 int error; 972 973 error = devfs_get_cdevpriv((void **)&d); 974 if (error != 0) 975 return (error); 976 977 /* 978 * Refresh PID associated with this descriptor. 979 */ 980 BPFD_LOCK(d); 981 d->bd_pid = td->td_proc->p_pid; 982 if (d->bd_state == BPF_WAITING) 983 callout_stop(&d->bd_callout); 984 d->bd_state = BPF_IDLE; 985 BPFD_UNLOCK(d); 986 987 if (d->bd_locked == 1) { 988 switch (cmd) { 989 case BIOCGBLEN: 990 case BIOCFLUSH: 991 case BIOCGDLT: 992 case BIOCGDLTLIST: 993 case BIOCGETIF: 994 case BIOCGRTIMEOUT: 995 case BIOCGSTATS: 996 case BIOCVERSION: 997 case BIOCGRSIG: 998 case BIOCGHDRCMPLT: 999 case BIOCFEEDBACK: 1000 case FIONREAD: 1001 case BIOCLOCK: 1002 case BIOCSRTIMEOUT: 1003 case BIOCIMMEDIATE: 1004 case TIOCGPGRP: 1005 case BIOCROTZBUF: 1006 break; 1007 default: 1008 return (EPERM); 1009 } 1010 } 1011 CURVNET_SET(TD_TO_VNET(td)); 1012 switch (cmd) { 1013 1014 default: 1015 error = EINVAL; 1016 break; 1017 1018 /* 1019 * Check for read packet available. 1020 */ 1021 case FIONREAD: 1022 { 1023 int n; 1024 1025 BPFD_LOCK(d); 1026 n = d->bd_slen; 1027 if (d->bd_hbuf) 1028 n += d->bd_hlen; 1029 BPFD_UNLOCK(d); 1030 1031 *(int *)addr = n; 1032 break; 1033 } 1034 1035 case SIOCGIFADDR: 1036 { 1037 struct ifnet *ifp; 1038 1039 if (d->bd_bif == NULL) 1040 error = EINVAL; 1041 else { 1042 ifp = d->bd_bif->bif_ifp; 1043 error = (*ifp->if_ioctl)(ifp, cmd, addr); 1044 } 1045 break; 1046 } 1047 1048 /* 1049 * Get buffer len [for read()]. 1050 */ 1051 case BIOCGBLEN: 1052 *(u_int *)addr = d->bd_bufsize; 1053 break; 1054 1055 /* 1056 * Set buffer length. 1057 */ 1058 case BIOCSBLEN: 1059 error = bpf_ioctl_sblen(d, (u_int *)addr); 1060 break; 1061 1062 /* 1063 * Set link layer read filter. 1064 */ 1065 case BIOCSETF: 1066 case BIOCSETFNR: 1067 case BIOCSETWF: 1068 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1069 break; 1070 1071 /* 1072 * Flush read packet buffer. 1073 */ 1074 case BIOCFLUSH: 1075 BPFD_LOCK(d); 1076 reset_d(d); 1077 BPFD_UNLOCK(d); 1078 break; 1079 1080 /* 1081 * Put interface into promiscuous mode. 1082 */ 1083 case BIOCPROMISC: 1084 if (d->bd_bif == NULL) { 1085 /* 1086 * No interface attached yet. 1087 */ 1088 error = EINVAL; 1089 break; 1090 } 1091 if (d->bd_promisc == 0) { 1092 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1093 if (error == 0) 1094 d->bd_promisc = 1; 1095 } 1096 break; 1097 1098 /* 1099 * Get current data link type. 1100 */ 1101 case BIOCGDLT: 1102 if (d->bd_bif == NULL) 1103 error = EINVAL; 1104 else 1105 *(u_int *)addr = d->bd_bif->bif_dlt; 1106 break; 1107 1108 /* 1109 * Get a list of supported data link types. 1110 */ 1111 case BIOCGDLTLIST: 1112 if (d->bd_bif == NULL) 1113 error = EINVAL; 1114 else 1115 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1116 break; 1117 1118 /* 1119 * Set data link type. 1120 */ 1121 case BIOCSDLT: 1122 if (d->bd_bif == NULL) 1123 error = EINVAL; 1124 else 1125 error = bpf_setdlt(d, *(u_int *)addr); 1126 break; 1127 1128 /* 1129 * Get interface name. 1130 */ 1131 case BIOCGETIF: 1132 if (d->bd_bif == NULL) 1133 error = EINVAL; 1134 else { 1135 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1136 struct ifreq *const ifr = (struct ifreq *)addr; 1137 1138 strlcpy(ifr->ifr_name, ifp->if_xname, 1139 sizeof(ifr->ifr_name)); 1140 } 1141 break; 1142 1143 /* 1144 * Set interface. 1145 */ 1146 case BIOCSETIF: 1147 error = bpf_setif(d, (struct ifreq *)addr); 1148 break; 1149 1150 /* 1151 * Set read timeout. 1152 */ 1153 case BIOCSRTIMEOUT: 1154 { 1155 struct timeval *tv = (struct timeval *)addr; 1156 1157 /* 1158 * Subtract 1 tick from tvtohz() since this isn't 1159 * a one-shot timer. 1160 */ 1161 if ((error = itimerfix(tv)) == 0) 1162 d->bd_rtout = tvtohz(tv) - 1; 1163 break; 1164 } 1165 1166 /* 1167 * Get read timeout. 1168 */ 1169 case BIOCGRTIMEOUT: 1170 { 1171 struct timeval *tv = (struct timeval *)addr; 1172 1173 tv->tv_sec = d->bd_rtout / hz; 1174 tv->tv_usec = (d->bd_rtout % hz) * tick; 1175 break; 1176 } 1177 1178 /* 1179 * Get packet stats. 1180 */ 1181 case BIOCGSTATS: 1182 { 1183 struct bpf_stat *bs = (struct bpf_stat *)addr; 1184 1185 /* XXXCSJP overflow */ 1186 bs->bs_recv = d->bd_rcount; 1187 bs->bs_drop = d->bd_dcount; 1188 break; 1189 } 1190 1191 /* 1192 * Set immediate mode. 1193 */ 1194 case BIOCIMMEDIATE: 1195 d->bd_immediate = *(u_int *)addr; 1196 break; 1197 1198 case BIOCVERSION: 1199 { 1200 struct bpf_version *bv = (struct bpf_version *)addr; 1201 1202 bv->bv_major = BPF_MAJOR_VERSION; 1203 bv->bv_minor = BPF_MINOR_VERSION; 1204 break; 1205 } 1206 1207 /* 1208 * Get "header already complete" flag 1209 */ 1210 case BIOCGHDRCMPLT: 1211 *(u_int *)addr = d->bd_hdrcmplt; 1212 break; 1213 1214 /* 1215 * Set "header already complete" flag 1216 */ 1217 case BIOCSHDRCMPLT: 1218 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1219 break; 1220 1221 /* 1222 * Get packet direction flag 1223 */ 1224 case BIOCGDIRECTION: 1225 *(u_int *)addr = d->bd_direction; 1226 break; 1227 1228 /* 1229 * Set packet direction flag 1230 */ 1231 case BIOCSDIRECTION: 1232 { 1233 u_int direction; 1234 1235 direction = *(u_int *)addr; 1236 switch (direction) { 1237 case BPF_D_IN: 1238 case BPF_D_INOUT: 1239 case BPF_D_OUT: 1240 d->bd_direction = direction; 1241 break; 1242 default: 1243 error = EINVAL; 1244 } 1245 } 1246 break; 1247 1248 case BIOCFEEDBACK: 1249 d->bd_feedback = *(u_int *)addr; 1250 break; 1251 1252 case BIOCLOCK: 1253 d->bd_locked = 1; 1254 break; 1255 1256 case FIONBIO: /* Non-blocking I/O */ 1257 break; 1258 1259 case FIOASYNC: /* Send signal on receive packets */ 1260 d->bd_async = *(int *)addr; 1261 break; 1262 1263 case FIOSETOWN: 1264 error = fsetown(*(int *)addr, &d->bd_sigio); 1265 break; 1266 1267 case FIOGETOWN: 1268 *(int *)addr = fgetown(&d->bd_sigio); 1269 break; 1270 1271 /* This is deprecated, FIOSETOWN should be used instead. */ 1272 case TIOCSPGRP: 1273 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1274 break; 1275 1276 /* This is deprecated, FIOGETOWN should be used instead. */ 1277 case TIOCGPGRP: 1278 *(int *)addr = -fgetown(&d->bd_sigio); 1279 break; 1280 1281 case BIOCSRSIG: /* Set receive signal */ 1282 { 1283 u_int sig; 1284 1285 sig = *(u_int *)addr; 1286 1287 if (sig >= NSIG) 1288 error = EINVAL; 1289 else 1290 d->bd_sig = sig; 1291 break; 1292 } 1293 case BIOCGRSIG: 1294 *(u_int *)addr = d->bd_sig; 1295 break; 1296 1297 case BIOCGETBUFMODE: 1298 *(u_int *)addr = d->bd_bufmode; 1299 break; 1300 1301 case BIOCSETBUFMODE: 1302 /* 1303 * Allow the buffering mode to be changed as long as we 1304 * haven't yet committed to a particular mode. Our 1305 * definition of commitment, for now, is whether or not a 1306 * buffer has been allocated or an interface attached, since 1307 * that's the point where things get tricky. 1308 */ 1309 switch (*(u_int *)addr) { 1310 case BPF_BUFMODE_BUFFER: 1311 break; 1312 1313 case BPF_BUFMODE_ZBUF: 1314 if (bpf_zerocopy_enable) 1315 break; 1316 /* FALLSTHROUGH */ 1317 1318 default: 1319 return (EINVAL); 1320 } 1321 1322 BPFD_LOCK(d); 1323 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1324 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1325 BPFD_UNLOCK(d); 1326 return (EBUSY); 1327 } 1328 d->bd_bufmode = *(u_int *)addr; 1329 BPFD_UNLOCK(d); 1330 break; 1331 1332 case BIOCGETZMAX: 1333 return (bpf_ioctl_getzmax(td, d, (size_t *)addr)); 1334 1335 case BIOCSETZBUF: 1336 return (bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr)); 1337 1338 case BIOCROTZBUF: 1339 return (bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr)); 1340 } 1341 CURVNET_RESTORE(); 1342 return (error); 1343} 1344 1345/* 1346 * Set d's packet filter program to fp. If this file already has a filter, 1347 * free it and replace it. Returns EINVAL for bogus requests. 1348 */ 1349static int 1350bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1351{ 1352 struct bpf_insn *fcode, *old; 1353 u_int wfilter, flen, size; 1354#ifdef BPF_JITTER 1355 bpf_jit_filter *ofunc; 1356#endif 1357 1358 if (cmd == BIOCSETWF) { 1359 old = d->bd_wfilter; 1360 wfilter = 1; 1361#ifdef BPF_JITTER 1362 ofunc = NULL; 1363#endif 1364 } else { 1365 wfilter = 0; 1366 old = d->bd_rfilter; 1367#ifdef BPF_JITTER 1368 ofunc = d->bd_bfilter; 1369#endif 1370 } 1371 if (fp->bf_insns == NULL) { 1372 if (fp->bf_len != 0) 1373 return (EINVAL); 1374 BPFD_LOCK(d); 1375 if (wfilter) 1376 d->bd_wfilter = NULL; 1377 else { 1378 d->bd_rfilter = NULL; 1379#ifdef BPF_JITTER 1380 d->bd_bfilter = NULL; 1381#endif 1382 if (cmd == BIOCSETF) 1383 reset_d(d); 1384 } 1385 BPFD_UNLOCK(d); 1386 if (old != NULL) 1387 free((caddr_t)old, M_BPF); 1388#ifdef BPF_JITTER 1389 if (ofunc != NULL) 1390 bpf_destroy_jit_filter(ofunc); 1391#endif 1392 return (0); 1393 } 1394 flen = fp->bf_len; 1395 if (flen > bpf_maxinsns) 1396 return (EINVAL); 1397 1398 size = flen * sizeof(*fp->bf_insns); 1399 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 1400 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 1401 bpf_validate(fcode, (int)flen)) { 1402 BPFD_LOCK(d); 1403 if (wfilter) 1404 d->bd_wfilter = fcode; 1405 else { 1406 d->bd_rfilter = fcode; 1407#ifdef BPF_JITTER 1408 d->bd_bfilter = bpf_jitter(fcode, flen); 1409#endif 1410 if (cmd == BIOCSETF) 1411 reset_d(d); 1412 } 1413 BPFD_UNLOCK(d); 1414 if (old != NULL) 1415 free((caddr_t)old, M_BPF); 1416#ifdef BPF_JITTER 1417 if (ofunc != NULL) 1418 bpf_destroy_jit_filter(ofunc); 1419#endif 1420 1421 return (0); 1422 } 1423 free((caddr_t)fcode, M_BPF); 1424 return (EINVAL); 1425} 1426 1427/* 1428 * Detach a file from its current interface (if attached at all) and attach 1429 * to the interface indicated by the name stored in ifr. 1430 * Return an errno or 0. 1431 */ 1432static int 1433bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1434{ 1435 struct bpf_if *bp; 1436 struct ifnet *theywant; 1437 1438 theywant = ifunit(ifr->ifr_name); 1439 if (theywant == NULL || theywant->if_bpf == NULL) 1440 return (ENXIO); 1441 1442 bp = theywant->if_bpf; 1443 1444 /* 1445 * Behavior here depends on the buffering model. If we're using 1446 * kernel memory buffers, then we can allocate them here. If we're 1447 * using zero-copy, then the user process must have registered 1448 * buffers by the time we get here. If not, return an error. 1449 * 1450 * XXXRW: There are locking issues here with multi-threaded use: what 1451 * if two threads try to set the interface at once? 1452 */ 1453 switch (d->bd_bufmode) { 1454 case BPF_BUFMODE_BUFFER: 1455 if (d->bd_sbuf == NULL) 1456 bpf_buffer_alloc(d); 1457 KASSERT(d->bd_sbuf != NULL, ("bpf_setif: bd_sbuf NULL")); 1458 break; 1459 1460 case BPF_BUFMODE_ZBUF: 1461 if (d->bd_sbuf == NULL) 1462 return (EINVAL); 1463 break; 1464 1465 default: 1466 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1467 } 1468 if (bp != d->bd_bif) { 1469 if (d->bd_bif) 1470 /* 1471 * Detach if attached to something else. 1472 */ 1473 bpf_detachd(d); 1474 1475 bpf_attachd(d, bp); 1476 } 1477 BPFD_LOCK(d); 1478 reset_d(d); 1479 BPFD_UNLOCK(d); 1480 return (0); 1481} 1482 1483/* 1484 * Support for select() and poll() system calls 1485 * 1486 * Return true iff the specific operation will not block indefinitely. 1487 * Otherwise, return false but make a note that a selwakeup() must be done. 1488 */ 1489static int 1490bpfpoll(struct cdev *dev, int events, struct thread *td) 1491{ 1492 struct bpf_d *d; 1493 int revents; 1494 1495 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 1496 return (events & 1497 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 1498 1499 /* 1500 * Refresh PID associated with this descriptor. 1501 */ 1502 revents = events & (POLLOUT | POLLWRNORM); 1503 BPFD_LOCK(d); 1504 d->bd_pid = td->td_proc->p_pid; 1505 if (events & (POLLIN | POLLRDNORM)) { 1506 if (bpf_ready(d)) 1507 revents |= events & (POLLIN | POLLRDNORM); 1508 else { 1509 selrecord(td, &d->bd_sel); 1510 /* Start the read timeout if necessary. */ 1511 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1512 callout_reset(&d->bd_callout, d->bd_rtout, 1513 bpf_timed_out, d); 1514 d->bd_state = BPF_WAITING; 1515 } 1516 } 1517 } 1518 BPFD_UNLOCK(d); 1519 return (revents); 1520} 1521 1522/* 1523 * Support for kevent() system call. Register EVFILT_READ filters and 1524 * reject all others. 1525 */ 1526int 1527bpfkqfilter(struct cdev *dev, struct knote *kn) 1528{ 1529 struct bpf_d *d; 1530 1531 if (devfs_get_cdevpriv((void **)&d) != 0 || 1532 kn->kn_filter != EVFILT_READ) 1533 return (1); 1534 1535 /* 1536 * Refresh PID associated with this descriptor. 1537 */ 1538 BPFD_LOCK(d); 1539 d->bd_pid = curthread->td_proc->p_pid; 1540 kn->kn_fop = &bpfread_filtops; 1541 kn->kn_hook = d; 1542 knlist_add(&d->bd_sel.si_note, kn, 1); 1543 BPFD_UNLOCK(d); 1544 1545 return (0); 1546} 1547 1548static void 1549filt_bpfdetach(struct knote *kn) 1550{ 1551 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1552 1553 knlist_remove(&d->bd_sel.si_note, kn, 0); 1554} 1555 1556static int 1557filt_bpfread(struct knote *kn, long hint) 1558{ 1559 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1560 int ready; 1561 1562 BPFD_LOCK_ASSERT(d); 1563 ready = bpf_ready(d); 1564 if (ready) { 1565 kn->kn_data = d->bd_slen; 1566 if (d->bd_hbuf) 1567 kn->kn_data += d->bd_hlen; 1568 } 1569 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1570 callout_reset(&d->bd_callout, d->bd_rtout, 1571 bpf_timed_out, d); 1572 d->bd_state = BPF_WAITING; 1573 } 1574 1575 return (ready); 1576} 1577 1578/* 1579 * Incoming linkage from device drivers. Process the packet pkt, of length 1580 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1581 * by each process' filter, and if accepted, stashed into the corresponding 1582 * buffer. 1583 */ 1584void 1585bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1586{ 1587 struct bpf_d *d; 1588 u_int slen; 1589 int gottime; 1590 struct timeval tv; 1591 1592 gottime = 0; 1593 BPFIF_LOCK(bp); 1594 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1595 BPFD_LOCK(d); 1596 ++d->bd_rcount; 1597 /* 1598 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no 1599 * way for the caller to indiciate to us whether this packet 1600 * is inbound or outbound. In the bpf_mtap() routines, we use 1601 * the interface pointers on the mbuf to figure it out. 1602 */ 1603#ifdef BPF_JITTER 1604 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL) 1605 slen = (*(d->bd_bfilter->func))(pkt, pktlen, pktlen); 1606 else 1607#endif 1608 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1609 if (slen != 0) { 1610 d->bd_fcount++; 1611 if (!gottime) { 1612 microtime(&tv); 1613 gottime = 1; 1614 } 1615#ifdef MAC 1616 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1617#endif 1618 catchpacket(d, pkt, pktlen, slen, 1619 bpf_append_bytes, &tv); 1620 } 1621 BPFD_UNLOCK(d); 1622 } 1623 BPFIF_UNLOCK(bp); 1624} 1625 1626#define BPF_CHECK_DIRECTION(d, r, i) \ 1627 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 1628 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 1629 1630/* 1631 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1632 */ 1633void 1634bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1635{ 1636 struct bpf_d *d; 1637 u_int pktlen, slen; 1638 int gottime; 1639 struct timeval tv; 1640 1641 /* Skip outgoing duplicate packets. */ 1642 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 1643 m->m_flags &= ~M_PROMISC; 1644 return; 1645 } 1646 1647 gottime = 0; 1648 1649 pktlen = m_length(m, NULL); 1650 1651 BPFIF_LOCK(bp); 1652 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1653 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 1654 continue; 1655 BPFD_LOCK(d); 1656 ++d->bd_rcount; 1657#ifdef BPF_JITTER 1658 /* XXX We cannot handle multiple mbufs. */ 1659 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL && 1660 m->m_next == NULL) 1661 slen = (*(d->bd_bfilter->func))(mtod(m, u_char *), 1662 pktlen, pktlen); 1663 else 1664#endif 1665 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1666 if (slen != 0) { 1667 d->bd_fcount++; 1668 if (!gottime) { 1669 microtime(&tv); 1670 gottime = 1; 1671 } 1672#ifdef MAC 1673 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1674#endif 1675 catchpacket(d, (u_char *)m, pktlen, slen, 1676 bpf_append_mbuf, &tv); 1677 } 1678 BPFD_UNLOCK(d); 1679 } 1680 BPFIF_UNLOCK(bp); 1681} 1682 1683/* 1684 * Incoming linkage from device drivers, when packet is in 1685 * an mbuf chain and to be prepended by a contiguous header. 1686 */ 1687void 1688bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1689{ 1690 struct mbuf mb; 1691 struct bpf_d *d; 1692 u_int pktlen, slen; 1693 int gottime; 1694 struct timeval tv; 1695 1696 /* Skip outgoing duplicate packets. */ 1697 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 1698 m->m_flags &= ~M_PROMISC; 1699 return; 1700 } 1701 1702 gottime = 0; 1703 1704 pktlen = m_length(m, NULL); 1705 /* 1706 * Craft on-stack mbuf suitable for passing to bpf_filter. 1707 * Note that we cut corners here; we only setup what's 1708 * absolutely needed--this mbuf should never go anywhere else. 1709 */ 1710 mb.m_next = m; 1711 mb.m_data = data; 1712 mb.m_len = dlen; 1713 pktlen += dlen; 1714 1715 BPFIF_LOCK(bp); 1716 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1717 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 1718 continue; 1719 BPFD_LOCK(d); 1720 ++d->bd_rcount; 1721 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 1722 if (slen != 0) { 1723 d->bd_fcount++; 1724 if (!gottime) { 1725 microtime(&tv); 1726 gottime = 1; 1727 } 1728#ifdef MAC 1729 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1730#endif 1731 catchpacket(d, (u_char *)&mb, pktlen, slen, 1732 bpf_append_mbuf, &tv); 1733 } 1734 BPFD_UNLOCK(d); 1735 } 1736 BPFIF_UNLOCK(bp); 1737} 1738 1739#undef BPF_CHECK_DIRECTION 1740 1741/* 1742 * Move the packet data from interface memory (pkt) into the 1743 * store buffer. "cpfn" is the routine called to do the actual data 1744 * transfer. bcopy is passed in to copy contiguous chunks, while 1745 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 1746 * pkt is really an mbuf. 1747 */ 1748static void 1749catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1750 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 1751 struct timeval *tv) 1752{ 1753 struct bpf_hdr hdr; 1754 int totlen, curlen; 1755 int hdrlen = d->bd_bif->bif_hdrlen; 1756 int do_wakeup = 0; 1757 1758 BPFD_LOCK_ASSERT(d); 1759 1760 /* 1761 * Detect whether user space has released a buffer back to us, and if 1762 * so, move it from being a hold buffer to a free buffer. This may 1763 * not be the best place to do it (for example, we might only want to 1764 * run this check if we need the space), but for now it's a reliable 1765 * spot to do it. 1766 */ 1767 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 1768 d->bd_fbuf = d->bd_hbuf; 1769 d->bd_hbuf = NULL; 1770 d->bd_hlen = 0; 1771 bpf_buf_reclaimed(d); 1772 } 1773 1774 /* 1775 * Figure out how many bytes to move. If the packet is 1776 * greater or equal to the snapshot length, transfer that 1777 * much. Otherwise, transfer the whole packet (unless 1778 * we hit the buffer size limit). 1779 */ 1780 totlen = hdrlen + min(snaplen, pktlen); 1781 if (totlen > d->bd_bufsize) 1782 totlen = d->bd_bufsize; 1783 1784 /* 1785 * Round up the end of the previous packet to the next longword. 1786 * 1787 * Drop the packet if there's no room and no hope of room 1788 * If the packet would overflow the storage buffer or the storage 1789 * buffer is considered immutable by the buffer model, try to rotate 1790 * the buffer and wakeup pending processes. 1791 */ 1792 curlen = BPF_WORDALIGN(d->bd_slen); 1793 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 1794 if (d->bd_fbuf == NULL) { 1795 /* 1796 * There's no room in the store buffer, and no 1797 * prospect of room, so drop the packet. Notify the 1798 * buffer model. 1799 */ 1800 bpf_buffull(d); 1801 ++d->bd_dcount; 1802 return; 1803 } 1804 ROTATE_BUFFERS(d); 1805 do_wakeup = 1; 1806 curlen = 0; 1807 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1808 /* 1809 * Immediate mode is set, or the read timeout has already 1810 * expired during a select call. A packet arrived, so the 1811 * reader should be woken up. 1812 */ 1813 do_wakeup = 1; 1814 1815 /* 1816 * Append the bpf header. Note we append the actual header size, but 1817 * move forward the length of the header plus padding. 1818 */ 1819 bzero(&hdr, sizeof(hdr)); 1820 hdr.bh_tstamp = *tv; 1821 hdr.bh_datalen = pktlen; 1822 hdr.bh_hdrlen = hdrlen; 1823 hdr.bh_caplen = totlen - hdrlen; 1824 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 1825 1826 /* 1827 * Copy the packet data into the store buffer and update its length. 1828 */ 1829 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, hdr.bh_caplen); 1830 d->bd_slen = curlen + totlen; 1831 1832 if (do_wakeup) 1833 bpf_wakeup(d); 1834} 1835 1836/* 1837 * Free buffers currently in use by a descriptor. 1838 * Called on close. 1839 */ 1840static void 1841bpf_freed(struct bpf_d *d) 1842{ 1843 1844 /* 1845 * We don't need to lock out interrupts since this descriptor has 1846 * been detached from its interface and it yet hasn't been marked 1847 * free. 1848 */ 1849 bpf_free(d); 1850 if (d->bd_rfilter) { 1851 free((caddr_t)d->bd_rfilter, M_BPF); 1852#ifdef BPF_JITTER 1853 bpf_destroy_jit_filter(d->bd_bfilter); 1854#endif 1855 } 1856 if (d->bd_wfilter) 1857 free((caddr_t)d->bd_wfilter, M_BPF); 1858 mtx_destroy(&d->bd_mtx); 1859} 1860 1861/* 1862 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1863 * fixed size of the link header (variable length headers not yet supported). 1864 */ 1865void 1866bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1867{ 1868 1869 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1870} 1871 1872/* 1873 * Attach an interface to bpf. ifp is a pointer to the structure 1874 * defining the interface to be attached, dlt is the link layer type, 1875 * and hdrlen is the fixed size of the link header (variable length 1876 * headers are not yet supporrted). 1877 */ 1878void 1879bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1880{ 1881 struct bpf_if *bp; 1882 1883 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1884 if (bp == NULL) 1885 panic("bpfattach"); 1886 1887 LIST_INIT(&bp->bif_dlist); 1888 bp->bif_ifp = ifp; 1889 bp->bif_dlt = dlt; 1890 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1891 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 1892 *driverp = bp; 1893 1894 mtx_lock(&bpf_mtx); 1895 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1896 mtx_unlock(&bpf_mtx); 1897 1898 /* 1899 * Compute the length of the bpf header. This is not necessarily 1900 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1901 * that the network layer header begins on a longword boundary (for 1902 * performance reasons and to alleviate alignment restrictions). 1903 */ 1904 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1905 1906 if (bootverbose) 1907 if_printf(ifp, "bpf attached\n"); 1908} 1909 1910/* 1911 * Detach bpf from an interface. This involves detaching each descriptor 1912 * associated with the interface, and leaving bd_bif NULL. Notify each 1913 * descriptor as it's detached so that any sleepers wake up and get 1914 * ENXIO. 1915 */ 1916void 1917bpfdetach(struct ifnet *ifp) 1918{ 1919 struct bpf_if *bp; 1920 struct bpf_d *d; 1921 1922 /* Locate BPF interface information */ 1923 mtx_lock(&bpf_mtx); 1924 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1925 if (ifp == bp->bif_ifp) 1926 break; 1927 } 1928 1929 /* Interface wasn't attached */ 1930 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1931 mtx_unlock(&bpf_mtx); 1932 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1933 return; 1934 } 1935 1936 LIST_REMOVE(bp, bif_next); 1937 mtx_unlock(&bpf_mtx); 1938 1939 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1940 bpf_detachd(d); 1941 BPFD_LOCK(d); 1942 bpf_wakeup(d); 1943 BPFD_UNLOCK(d); 1944 } 1945 1946 mtx_destroy(&bp->bif_mtx); 1947 free(bp, M_BPF); 1948} 1949 1950/* 1951 * Get a list of available data link type of the interface. 1952 */ 1953static int 1954bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1955{ 1956 int n, error; 1957 struct ifnet *ifp; 1958 struct bpf_if *bp; 1959 1960 ifp = d->bd_bif->bif_ifp; 1961 n = 0; 1962 error = 0; 1963 mtx_lock(&bpf_mtx); 1964 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1965 if (bp->bif_ifp != ifp) 1966 continue; 1967 if (bfl->bfl_list != NULL) { 1968 if (n >= bfl->bfl_len) { 1969 mtx_unlock(&bpf_mtx); 1970 return (ENOMEM); 1971 } 1972 error = copyout(&bp->bif_dlt, 1973 bfl->bfl_list + n, sizeof(u_int)); 1974 } 1975 n++; 1976 } 1977 mtx_unlock(&bpf_mtx); 1978 bfl->bfl_len = n; 1979 return (error); 1980} 1981 1982/* 1983 * Set the data link type of a BPF instance. 1984 */ 1985static int 1986bpf_setdlt(struct bpf_d *d, u_int dlt) 1987{ 1988 int error, opromisc; 1989 struct ifnet *ifp; 1990 struct bpf_if *bp; 1991 1992 if (d->bd_bif->bif_dlt == dlt) 1993 return (0); 1994 ifp = d->bd_bif->bif_ifp; 1995 mtx_lock(&bpf_mtx); 1996 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1997 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1998 break; 1999 } 2000 mtx_unlock(&bpf_mtx); 2001 if (bp != NULL) { 2002 opromisc = d->bd_promisc; 2003 bpf_detachd(d); 2004 bpf_attachd(d, bp); 2005 BPFD_LOCK(d); 2006 reset_d(d); 2007 BPFD_UNLOCK(d); 2008 if (opromisc) { 2009 error = ifpromisc(bp->bif_ifp, 1); 2010 if (error) 2011 if_printf(bp->bif_ifp, 2012 "bpf_setdlt: ifpromisc failed (%d)\n", 2013 error); 2014 else 2015 d->bd_promisc = 1; 2016 } 2017 } 2018 return (bp == NULL ? EINVAL : 0); 2019} 2020 2021static void 2022bpf_drvinit(void *unused) 2023{ 2024 struct cdev *dev; 2025 2026 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2027 LIST_INIT(&bpf_iflist); 2028 2029 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2030 /* For compatibility */ 2031 make_dev_alias(dev, "bpf0"); 2032 2033} 2034 2035static void 2036bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2037{ 2038 2039 bzero(d, sizeof(*d)); 2040 BPFD_LOCK_ASSERT(bd); 2041 d->bd_structsize = sizeof(*d); 2042 d->bd_immediate = bd->bd_immediate; 2043 d->bd_promisc = bd->bd_promisc; 2044 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2045 d->bd_direction = bd->bd_direction; 2046 d->bd_feedback = bd->bd_feedback; 2047 d->bd_async = bd->bd_async; 2048 d->bd_rcount = bd->bd_rcount; 2049 d->bd_dcount = bd->bd_dcount; 2050 d->bd_fcount = bd->bd_fcount; 2051 d->bd_sig = bd->bd_sig; 2052 d->bd_slen = bd->bd_slen; 2053 d->bd_hlen = bd->bd_hlen; 2054 d->bd_bufsize = bd->bd_bufsize; 2055 d->bd_pid = bd->bd_pid; 2056 strlcpy(d->bd_ifname, 2057 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2058 d->bd_locked = bd->bd_locked; 2059 d->bd_wcount = bd->bd_wcount; 2060 d->bd_wdcount = bd->bd_wdcount; 2061 d->bd_wfcount = bd->bd_wfcount; 2062 d->bd_zcopy = bd->bd_zcopy; 2063 d->bd_bufmode = bd->bd_bufmode; 2064} 2065 2066static int 2067bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2068{ 2069 struct xbpf_d *xbdbuf, *xbd; 2070 int index, error; 2071 struct bpf_if *bp; 2072 struct bpf_d *bd; 2073 2074 /* 2075 * XXX This is not technically correct. It is possible for non 2076 * privileged users to open bpf devices. It would make sense 2077 * if the users who opened the devices were able to retrieve 2078 * the statistics for them, too. 2079 */ 2080 error = priv_check(req->td, PRIV_NET_BPF); 2081 if (error) 2082 return (error); 2083 if (req->oldptr == NULL) 2084 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2085 if (bpf_bpfd_cnt == 0) 2086 return (SYSCTL_OUT(req, 0, 0)); 2087 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2088 mtx_lock(&bpf_mtx); 2089 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2090 mtx_unlock(&bpf_mtx); 2091 free(xbdbuf, M_BPF); 2092 return (ENOMEM); 2093 } 2094 index = 0; 2095 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2096 BPFIF_LOCK(bp); 2097 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2098 xbd = &xbdbuf[index++]; 2099 BPFD_LOCK(bd); 2100 bpfstats_fill_xbpf(xbd, bd); 2101 BPFD_UNLOCK(bd); 2102 } 2103 BPFIF_UNLOCK(bp); 2104 } 2105 mtx_unlock(&bpf_mtx); 2106 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2107 free(xbdbuf, M_BPF); 2108 return (error); 2109} 2110 2111SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2112 2113#else /* !DEV_BPF && !NETGRAPH_BPF */ 2114/* 2115 * NOP stubs to allow bpf-using drivers to load and function. 2116 * 2117 * A 'better' implementation would allow the core bpf functionality 2118 * to be loaded at runtime. 2119 */ 2120static struct bpf_if bp_null; 2121 2122void 2123bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2124{ 2125} 2126 2127void 2128bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2129{ 2130} 2131 2132void 2133bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2134{ 2135} 2136 2137void 2138bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2139{ 2140 2141 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2142} 2143 2144void 2145bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2146{ 2147 2148 *driverp = &bp_null; 2149} 2150 2151void 2152bpfdetach(struct ifnet *ifp) 2153{ 2154} 2155 2156u_int 2157bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 2158{ 2159 return -1; /* "no filter" behaviour */ 2160} 2161 2162int 2163bpf_validate(const struct bpf_insn *f, int len) 2164{ 2165 return 0; /* false */ 2166} 2167 2168#endif /* !DEV_BPF && !NETGRAPH_BPF */ 2169