1 /* 2 * Copyright (c) 1990, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from the Stanford/CMU enet packet filter, 6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 8 * Berkeley Laboratory. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 39 * 40 * $FreeBSD$ 41 */ 42 43 #include "opt_bpf.h" 44 #include "opt_mac.h" 45 #include "opt_netgraph.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/conf.h> 50 #include <sys/mac.h> 51 #include <sys/malloc.h> 52 #include <sys/mbuf.h> 53 #include <sys/time.h> 54 #include <sys/proc.h> 55 #include <sys/signalvar.h> 56 #include <sys/filio.h> 57 #include <sys/sockio.h> 58 #include <sys/ttycom.h> 59 #include <sys/filedesc.h> 60 61 #include <sys/poll.h> 62 63 #include <sys/socket.h> 64 #include <sys/vnode.h> 65 66 #include <net/if.h> 67 #include <net/bpf.h> 68 #include <net/bpfdesc.h> 69 70 #include <netinet/in.h> 71 #include <netinet/if_ether.h> 72 #include <sys/kernel.h> 73 #include <sys/sysctl.h> 74 75 static MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 76 77 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 78 79 #define PRINET 26 /* interruptible */ 80 81 /* 82 * The default read buffer size is patchable. 83 */ 84 static int bpf_bufsize = 4096; 85 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 86 &bpf_bufsize, 0, ""); 87 static int bpf_maxbufsize = BPF_MAXBUFSIZE; 88 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 89 &bpf_maxbufsize, 0, ""); 90 91 /* 92 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 93 */ 94 static struct bpf_if *bpf_iflist; 95 static struct mtx bpf_mtx; /* bpf global lock */ 96 97 static int bpf_allocbufs(struct bpf_d *); 98 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 99 static void bpf_detachd(struct bpf_d *d); 100 static void bpf_freed(struct bpf_d *); 101 static void bpf_mcopy(const void *, void *, size_t); 102 static int bpf_movein(struct uio *, int, 103 struct mbuf **, struct sockaddr *, int *); 104 static int bpf_setif(struct bpf_d *, struct ifreq *); 105 static void bpf_timed_out(void *); 106 static __inline void 107 bpf_wakeup(struct bpf_d *); 108 static void catchpacket(struct bpf_d *, u_char *, u_int, 109 u_int, void (*)(const void *, void *, size_t)); 110 static void reset_d(struct bpf_d *); 111 static int bpf_setf(struct bpf_d *, struct bpf_program *); 112 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 113 static int bpf_setdlt(struct bpf_d *, u_int); 114 115 static d_open_t bpfopen; 116 static d_close_t bpfclose; 117 static d_read_t bpfread; 118 static d_write_t bpfwrite; 119 static d_ioctl_t bpfioctl; 120 static d_poll_t bpfpoll; 121 122 #define CDEV_MAJOR 23 123 static struct cdevsw bpf_cdevsw = { 124 .d_open = bpfopen, 125 .d_close = bpfclose, 126 .d_read = bpfread, 127 .d_write = bpfwrite, 128 .d_ioctl = bpfioctl, 129 .d_poll = bpfpoll, 130 .d_name = "bpf", 131 .d_maj = CDEV_MAJOR, 132 }; 133 134 135 static int 136 bpf_movein(uio, linktype, mp, sockp, datlen) 137 struct uio *uio; 138 int linktype, *datlen; 139 struct mbuf **mp; 140 struct sockaddr *sockp; 141 { 142 struct mbuf *m; 143 int error; 144 int len; 145 int hlen; 146 147 /* 148 * Build a sockaddr based on the data link layer type. 149 * We do this at this level because the ethernet header 150 * is copied directly into the data field of the sockaddr. 151 * In the case of SLIP, there is no header and the packet 152 * is forwarded as is. 153 * Also, we are careful to leave room at the front of the mbuf 154 * for the link level header. 155 */ 156 switch (linktype) { 157 158 case DLT_SLIP: 159 sockp->sa_family = AF_INET; 160 hlen = 0; 161 break; 162 163 case DLT_EN10MB: 164 sockp->sa_family = AF_UNSPEC; 165 /* XXX Would MAXLINKHDR be better? */ 166 hlen = ETHER_HDR_LEN; 167 break; 168 169 case DLT_FDDI: 170 sockp->sa_family = AF_IMPLINK; 171 hlen = 0; 172 break; 173 174 case DLT_RAW: 175 case DLT_NULL: 176 sockp->sa_family = AF_UNSPEC; 177 hlen = 0; 178 break; 179 180 case DLT_ATM_RFC1483: 181 /* 182 * en atm driver requires 4-byte atm pseudo header. 183 * though it isn't standard, vpi:vci needs to be 184 * specified anyway. 185 */ 186 sockp->sa_family = AF_UNSPEC; 187 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 188 break; 189 190 case DLT_PPP: 191 sockp->sa_family = AF_UNSPEC; 192 hlen = 4; /* This should match PPP_HDRLEN */ 193 break; 194 195 default: 196 return (EIO); 197 } 198 199 len = uio->uio_resid; 200 *datlen = len - hlen; 201 if ((unsigned)len > MCLBYTES) 202 return (EIO); 203 204 if (len > MHLEN) { 205 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 206 } else { 207 MGETHDR(m, M_TRYWAIT, MT_DATA); 208 } 209 if (m == NULL) 210 return (ENOBUFS); 211 m->m_pkthdr.len = m->m_len = len; 212 m->m_pkthdr.rcvif = NULL; 213 *mp = m; 214 215 /* 216 * Make room for link header. 217 */ 218 if (hlen != 0) { 219 m->m_pkthdr.len -= hlen; 220 m->m_len -= hlen; 221 #if BSD >= 199103 222 m->m_data += hlen; /* XXX */ 223 #else 224 m->m_off += hlen; 225 #endif 226 error = uiomove(sockp->sa_data, hlen, uio); 227 if (error) 228 goto bad; 229 } 230 error = uiomove(mtod(m, void *), len - hlen, uio); 231 if (!error) 232 return (0); 233 bad: 234 m_freem(m); 235 return (error); 236 } 237 238 /* 239 * Attach file to the bpf interface, i.e. make d listen on bp. 240 */ 241 static void 242 bpf_attachd(d, bp) 243 struct bpf_d *d; 244 struct bpf_if *bp; 245 { 246 /* 247 * Point d at bp, and add d to the interface's list of listeners. 248 * Finally, point the driver's bpf cookie at the interface so 249 * it will divert packets to bpf. 250 */ 251 BPFIF_LOCK(bp); 252 d->bd_bif = bp; 253 d->bd_next = bp->bif_dlist; 254 bp->bif_dlist = d; 255 256 *bp->bif_driverp = bp; 257 BPFIF_UNLOCK(bp); 258 } 259 260 /* 261 * Detach a file from its interface. 262 */ 263 static void 264 bpf_detachd(d) 265 struct bpf_d *d; 266 { 267 int error; 268 struct bpf_d **p; 269 struct bpf_if *bp; 270 271 bp = d->bd_bif; 272 /* 273 * Check if this descriptor had requested promiscuous mode. 274 * If so, turn it off. 275 */ 276 if (d->bd_promisc) { 277 d->bd_promisc = 0; 278 error = ifpromisc(bp->bif_ifp, 0); 279 if (error != 0 && error != ENXIO) { 280 /* 281 * ENXIO can happen if a pccard is unplugged 282 * Something is really wrong if we were able to put 283 * the driver into promiscuous mode, but can't 284 * take it out. 285 */ 286 if_printf(bp->bif_ifp, 287 "bpf_detach: ifpromisc failed (%d)\n", error); 288 } 289 } 290 /* Remove d from the interface's descriptor list. */ 291 BPFIF_LOCK(bp); 292 p = &bp->bif_dlist; 293 while (*p != d) { 294 p = &(*p)->bd_next; 295 if (*p == 0) 296 panic("bpf_detachd: descriptor not in list"); 297 } 298 *p = (*p)->bd_next; 299 if (bp->bif_dlist == 0) 300 /* 301 * Let the driver know that there are no more listeners. 302 */ 303 *d->bd_bif->bif_driverp = 0; 304 BPFIF_UNLOCK(bp); 305 d->bd_bif = 0; 306 } 307 308 /* 309 * Open ethernet device. Returns ENXIO for illegal minor device number, 310 * EBUSY if file is open by another process. 311 */ 312 /* ARGSUSED */ 313 static int 314 bpfopen(dev, flags, fmt, td) 315 dev_t dev; 316 int flags; 317 int fmt; 318 struct thread *td; 319 { 320 struct bpf_d *d; 321 322 mtx_lock(&bpf_mtx); 323 d = dev->si_drv1; 324 /* 325 * Each minor can be opened by only one process. If the requested 326 * minor is in use, return EBUSY. 327 */ 328 if (d) { 329 mtx_unlock(&bpf_mtx); 330 return (EBUSY); 331 } 332 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 333 mtx_unlock(&bpf_mtx); 334 335 if ((dev->si_flags & SI_NAMED) == 0) 336 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 337 "bpf%d", dev2unit(dev)); 338 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 339 dev->si_drv1 = d; 340 d->bd_bufsize = bpf_bufsize; 341 d->bd_sig = SIGIO; 342 d->bd_seesent = 1; 343 #ifdef MAC 344 mac_init_bpfdesc(d); 345 mac_create_bpfdesc(td->td_ucred, d); 346 #endif 347 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 348 callout_init(&d->bd_callout, 1); 349 350 return (0); 351 } 352 353 /* 354 * Close the descriptor by detaching it from its interface, 355 * deallocating its buffers, and marking it free. 356 */ 357 /* ARGSUSED */ 358 static int 359 bpfclose(dev, flags, fmt, td) 360 dev_t dev; 361 int flags; 362 int fmt; 363 struct thread *td; 364 { 365 struct bpf_d *d = dev->si_drv1; 366 367 BPFD_LOCK(d); 368 if (d->bd_state == BPF_WAITING) 369 callout_stop(&d->bd_callout); 370 d->bd_state = BPF_IDLE; 371 BPFD_UNLOCK(d); 372 funsetown(&d->bd_sigio); 373 mtx_lock(&bpf_mtx); 374 if (d->bd_bif) 375 bpf_detachd(d); 376 mtx_unlock(&bpf_mtx); 377 #ifdef MAC 378 mac_destroy_bpfdesc(d); 379 #endif /* MAC */ 380 bpf_freed(d); 381 dev->si_drv1 = 0; 382 free(d, M_BPF); 383 384 return (0); 385 } 386 387 388 /* 389 * Rotate the packet buffers in descriptor d. Move the store buffer 390 * into the hold slot, and the free buffer into the store slot. 391 * Zero the length of the new store buffer. 392 */ 393 #define ROTATE_BUFFERS(d) \ 394 (d)->bd_hbuf = (d)->bd_sbuf; \ 395 (d)->bd_hlen = (d)->bd_slen; \ 396 (d)->bd_sbuf = (d)->bd_fbuf; \ 397 (d)->bd_slen = 0; \ 398 (d)->bd_fbuf = 0; 399 /* 400 * bpfread - read next chunk of packets from buffers 401 */ 402 static int 403 bpfread(dev, uio, ioflag) 404 dev_t dev; 405 struct uio *uio; 406 int ioflag; 407 { 408 struct bpf_d *d = dev->si_drv1; 409 int timed_out; 410 int error; 411 412 /* 413 * Restrict application to use a buffer the same size as 414 * as kernel buffers. 415 */ 416 if (uio->uio_resid != d->bd_bufsize) 417 return (EINVAL); 418 419 BPFD_LOCK(d); 420 if (d->bd_state == BPF_WAITING) 421 callout_stop(&d->bd_callout); 422 timed_out = (d->bd_state == BPF_TIMED_OUT); 423 d->bd_state = BPF_IDLE; 424 /* 425 * If the hold buffer is empty, then do a timed sleep, which 426 * ends when the timeout expires or when enough packets 427 * have arrived to fill the store buffer. 428 */ 429 while (d->bd_hbuf == 0) { 430 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 431 /* 432 * A packet(s) either arrived since the previous 433 * read or arrived while we were asleep. 434 * Rotate the buffers and return what's here. 435 */ 436 ROTATE_BUFFERS(d); 437 break; 438 } 439 440 /* 441 * No data is available, check to see if the bpf device 442 * is still pointed at a real interface. If not, return 443 * ENXIO so that the userland process knows to rebind 444 * it before using it again. 445 */ 446 if (d->bd_bif == NULL) { 447 BPFD_UNLOCK(d); 448 return (ENXIO); 449 } 450 451 if (ioflag & IO_NDELAY) { 452 BPFD_UNLOCK(d); 453 return (EWOULDBLOCK); 454 } 455 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 456 "bpf", d->bd_rtout); 457 if (error == EINTR || error == ERESTART) { 458 BPFD_UNLOCK(d); 459 return (error); 460 } 461 if (error == EWOULDBLOCK) { 462 /* 463 * On a timeout, return what's in the buffer, 464 * which may be nothing. If there is something 465 * in the store buffer, we can rotate the buffers. 466 */ 467 if (d->bd_hbuf) 468 /* 469 * We filled up the buffer in between 470 * getting the timeout and arriving 471 * here, so we don't need to rotate. 472 */ 473 break; 474 475 if (d->bd_slen == 0) { 476 BPFD_UNLOCK(d); 477 return (0); 478 } 479 ROTATE_BUFFERS(d); 480 break; 481 } 482 } 483 /* 484 * At this point, we know we have something in the hold slot. 485 */ 486 BPFD_UNLOCK(d); 487 488 /* 489 * Move data from hold buffer into user space. 490 * We know the entire buffer is transferred since 491 * we checked above that the read buffer is bpf_bufsize bytes. 492 */ 493 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 494 495 BPFD_LOCK(d); 496 d->bd_fbuf = d->bd_hbuf; 497 d->bd_hbuf = 0; 498 d->bd_hlen = 0; 499 BPFD_UNLOCK(d); 500 501 return (error); 502 } 503 504 505 /* 506 * If there are processes sleeping on this descriptor, wake them up. 507 */ 508 static __inline void 509 bpf_wakeup(d) 510 struct bpf_d *d; 511 { 512 if (d->bd_state == BPF_WAITING) { 513 callout_stop(&d->bd_callout); 514 d->bd_state = BPF_IDLE; 515 } 516 wakeup(d); 517 if (d->bd_async && d->bd_sig && d->bd_sigio) 518 pgsigio(&d->bd_sigio, d->bd_sig, 0); 519 520 selwakeup(&d->bd_sel); 521 } 522 523 static void 524 bpf_timed_out(arg) 525 void *arg; 526 { 527 struct bpf_d *d = (struct bpf_d *)arg; 528 529 BPFD_LOCK(d); 530 if (d->bd_state == BPF_WAITING) { 531 d->bd_state = BPF_TIMED_OUT; 532 if (d->bd_slen != 0) 533 bpf_wakeup(d); 534 } 535 BPFD_UNLOCK(d); 536 } 537 538 static int 539 bpfwrite(dev, uio, ioflag) 540 dev_t dev; 541 struct uio *uio; 542 int ioflag; 543 { 544 struct bpf_d *d = dev->si_drv1; 545 struct ifnet *ifp; 546 struct mbuf *m; 547 int error; 548 static struct sockaddr dst; 549 int datlen; 550 551 if (d->bd_bif == 0) 552 return (ENXIO); 553 554 ifp = d->bd_bif->bif_ifp; 555 556 if (uio->uio_resid == 0) 557 return (0); 558 559 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 560 if (error) 561 return (error); 562 563 if (datlen > ifp->if_mtu) 564 return (EMSGSIZE); 565 566 if (d->bd_hdrcmplt) 567 dst.sa_family = pseudo_AF_HDRCMPLT; 568 569 mtx_lock(&Giant); 570 #ifdef MAC 571 mac_create_mbuf_from_bpfdesc(d, m); 572 #endif 573 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); 574 mtx_unlock(&Giant); 575 /* 576 * The driver frees the mbuf. 577 */ 578 return (error); 579 } 580 581 /* 582 * Reset a descriptor by flushing its packet buffer and clearing the 583 * receive and drop counts. 584 */ 585 static void 586 reset_d(d) 587 struct bpf_d *d; 588 { 589 590 mtx_assert(&d->bd_mtx, MA_OWNED); 591 if (d->bd_hbuf) { 592 /* Free the hold buffer. */ 593 d->bd_fbuf = d->bd_hbuf; 594 d->bd_hbuf = 0; 595 } 596 d->bd_slen = 0; 597 d->bd_hlen = 0; 598 d->bd_rcount = 0; 599 d->bd_dcount = 0; 600 } 601 602 /* 603 * FIONREAD Check for read packet available. 604 * SIOCGIFADDR Get interface address - convenient hook to driver. 605 * BIOCGBLEN Get buffer len [for read()]. 606 * BIOCSETF Set ethernet read filter. 607 * BIOCFLUSH Flush read packet buffer. 608 * BIOCPROMISC Put interface into promiscuous mode. 609 * BIOCGDLT Get link layer type. 610 * BIOCGETIF Get interface name. 611 * BIOCSETIF Set interface. 612 * BIOCSRTIMEOUT Set read timeout. 613 * BIOCGRTIMEOUT Get read timeout. 614 * BIOCGSTATS Get packet stats. 615 * BIOCIMMEDIATE Set immediate mode. 616 * BIOCVERSION Get filter language version. 617 * BIOCGHDRCMPLT Get "header already complete" flag 618 * BIOCSHDRCMPLT Set "header already complete" flag 619 * BIOCGSEESENT Get "see packets sent" flag 620 * BIOCSSEESENT Set "see packets sent" flag 621 */ 622 /* ARGSUSED */ 623 static int 624 bpfioctl(dev, cmd, addr, flags, td) 625 dev_t dev; 626 u_long cmd; 627 caddr_t addr; 628 int flags; 629 struct thread *td; 630 { 631 struct bpf_d *d = dev->si_drv1; 632 int error = 0; 633 634 BPFD_LOCK(d); 635 if (d->bd_state == BPF_WAITING) 636 callout_stop(&d->bd_callout); 637 d->bd_state = BPF_IDLE; 638 BPFD_UNLOCK(d); 639 640 switch (cmd) { 641 642 default: 643 error = EINVAL; 644 break; 645 646 /* 647 * Check for read packet available. 648 */ 649 case FIONREAD: 650 { 651 int n; 652 653 BPFD_LOCK(d); 654 n = d->bd_slen; 655 if (d->bd_hbuf) 656 n += d->bd_hlen; 657 BPFD_UNLOCK(d); 658 659 *(int *)addr = n; 660 break; 661 } 662 663 case SIOCGIFADDR: 664 { 665 struct ifnet *ifp; 666 667 if (d->bd_bif == 0) 668 error = EINVAL; 669 else { 670 ifp = d->bd_bif->bif_ifp; 671 error = (*ifp->if_ioctl)(ifp, cmd, addr); 672 } 673 break; 674 } 675 676 /* 677 * Get buffer len [for read()]. 678 */ 679 case BIOCGBLEN: 680 *(u_int *)addr = d->bd_bufsize; 681 break; 682 683 /* 684 * Set buffer length. 685 */ 686 case BIOCSBLEN: 687 if (d->bd_bif != 0) 688 error = EINVAL; 689 else { 690 u_int size = *(u_int *)addr; 691 692 if (size > bpf_maxbufsize) 693 *(u_int *)addr = size = bpf_maxbufsize; 694 else if (size < BPF_MINBUFSIZE) 695 *(u_int *)addr = size = BPF_MINBUFSIZE; 696 d->bd_bufsize = size; 697 } 698 break; 699 700 /* 701 * Set link layer read filter. 702 */ 703 case BIOCSETF: 704 error = bpf_setf(d, (struct bpf_program *)addr); 705 break; 706 707 /* 708 * Flush read packet buffer. 709 */ 710 case BIOCFLUSH: 711 BPFD_LOCK(d); 712 reset_d(d); 713 BPFD_UNLOCK(d); 714 break; 715 716 /* 717 * Put interface into promiscuous mode. 718 */ 719 case BIOCPROMISC: 720 if (d->bd_bif == 0) { 721 /* 722 * No interface attached yet. 723 */ 724 error = EINVAL; 725 break; 726 } 727 if (d->bd_promisc == 0) { 728 mtx_lock(&Giant); 729 error = ifpromisc(d->bd_bif->bif_ifp, 1); 730 mtx_unlock(&Giant); 731 if (error == 0) 732 d->bd_promisc = 1; 733 } 734 break; 735 736 /* 737 * Get current data link type. 738 */ 739 case BIOCGDLT: 740 if (d->bd_bif == 0) 741 error = EINVAL; 742 else 743 *(u_int *)addr = d->bd_bif->bif_dlt; 744 break; 745 746 /* 747 * Get a list of supported data link types. 748 */ 749 case BIOCGDLTLIST: 750 if (d->bd_bif == 0) 751 error = EINVAL; 752 else 753 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 754 break; 755 756 /* 757 * Set data link type. 758 */ 759 case BIOCSDLT: 760 if (d->bd_bif == 0) 761 error = EINVAL; 762 else 763 error = bpf_setdlt(d, *(u_int *)addr); 764 break; 765 766 /* 767 * Get interface name. 768 */ 769 case BIOCGETIF: 770 if (d->bd_bif == 0) 771 error = EINVAL; 772 else { 773 struct ifnet *const ifp = d->bd_bif->bif_ifp; 774 struct ifreq *const ifr = (struct ifreq *)addr; 775 776 snprintf(ifr->ifr_name, sizeof(ifr->ifr_name), 777 "%s%d", ifp->if_name, ifp->if_unit); 778 } 779 break; 780 781 /* 782 * Set interface. 783 */ 784 case BIOCSETIF: 785 error = bpf_setif(d, (struct ifreq *)addr); 786 break; 787 788 /* 789 * Set read timeout. 790 */ 791 case BIOCSRTIMEOUT: 792 { 793 struct timeval *tv = (struct timeval *)addr; 794 795 /* 796 * Subtract 1 tick from tvtohz() since this isn't 797 * a one-shot timer. 798 */ 799 if ((error = itimerfix(tv)) == 0) 800 d->bd_rtout = tvtohz(tv) - 1; 801 break; 802 } 803 804 /* 805 * Get read timeout. 806 */ 807 case BIOCGRTIMEOUT: 808 { 809 struct timeval *tv = (struct timeval *)addr; 810 811 tv->tv_sec = d->bd_rtout / hz; 812 tv->tv_usec = (d->bd_rtout % hz) * tick; 813 break; 814 } 815 816 /* 817 * Get packet stats. 818 */ 819 case BIOCGSTATS: 820 { 821 struct bpf_stat *bs = (struct bpf_stat *)addr; 822 823 bs->bs_recv = d->bd_rcount; 824 bs->bs_drop = d->bd_dcount; 825 break; 826 } 827 828 /* 829 * Set immediate mode. 830 */ 831 case BIOCIMMEDIATE: 832 d->bd_immediate = *(u_int *)addr; 833 break; 834 835 case BIOCVERSION: 836 { 837 struct bpf_version *bv = (struct bpf_version *)addr; 838 839 bv->bv_major = BPF_MAJOR_VERSION; 840 bv->bv_minor = BPF_MINOR_VERSION; 841 break; 842 } 843 844 /* 845 * Get "header already complete" flag 846 */ 847 case BIOCGHDRCMPLT: 848 *(u_int *)addr = d->bd_hdrcmplt; 849 break; 850 851 /* 852 * Set "header already complete" flag 853 */ 854 case BIOCSHDRCMPLT: 855 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 856 break; 857 858 /* 859 * Get "see sent packets" flag 860 */ 861 case BIOCGSEESENT: 862 *(u_int *)addr = d->bd_seesent; 863 break; 864 865 /* 866 * Set "see sent packets" flag 867 */ 868 case BIOCSSEESENT: 869 d->bd_seesent = *(u_int *)addr; 870 break; 871 872 case FIONBIO: /* Non-blocking I/O */ 873 break; 874 875 case FIOASYNC: /* Send signal on receive packets */ 876 d->bd_async = *(int *)addr; 877 break; 878 879 case FIOSETOWN: 880 error = fsetown(*(int *)addr, &d->bd_sigio); 881 break; 882 883 case FIOGETOWN: 884 *(int *)addr = fgetown(&d->bd_sigio); 885 break; 886 887 /* This is deprecated, FIOSETOWN should be used instead. */ 888 case TIOCSPGRP: 889 error = fsetown(-(*(int *)addr), &d->bd_sigio); 890 break; 891 892 /* This is deprecated, FIOGETOWN should be used instead. */ 893 case TIOCGPGRP: 894 *(int *)addr = -fgetown(&d->bd_sigio); 895 break; 896 897 case BIOCSRSIG: /* Set receive signal */ 898 { 899 u_int sig; 900 901 sig = *(u_int *)addr; 902 903 if (sig >= NSIG) 904 error = EINVAL; 905 else 906 d->bd_sig = sig; 907 break; 908 } 909 case BIOCGRSIG: 910 *(u_int *)addr = d->bd_sig; 911 break; 912 } 913 return (error); 914 } 915 916 /* 917 * Set d's packet filter program to fp. If this file already has a filter, 918 * free it and replace it. Returns EINVAL for bogus requests. 919 */ 920 static int 921 bpf_setf(d, fp) 922 struct bpf_d *d; 923 struct bpf_program *fp; 924 { 925 struct bpf_insn *fcode, *old; 926 u_int flen, size; 927 928 old = d->bd_filter; 929 if (fp->bf_insns == 0) { 930 if (fp->bf_len != 0) 931 return (EINVAL); 932 BPFD_LOCK(d); 933 d->bd_filter = 0; 934 reset_d(d); 935 BPFD_UNLOCK(d); 936 if (old != 0) 937 free((caddr_t)old, M_BPF); 938 return (0); 939 } 940 flen = fp->bf_len; 941 if (flen > BPF_MAXINSNS) 942 return (EINVAL); 943 944 size = flen * sizeof(*fp->bf_insns); 945 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 946 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 947 bpf_validate(fcode, (int)flen)) { 948 BPFD_LOCK(d); 949 d->bd_filter = fcode; 950 reset_d(d); 951 BPFD_UNLOCK(d); 952 if (old != 0) 953 free((caddr_t)old, M_BPF); 954 955 return (0); 956 } 957 free((caddr_t)fcode, M_BPF); 958 return (EINVAL); 959 } 960 961 /* 962 * Detach a file from its current interface (if attached at all) and attach 963 * to the interface indicated by the name stored in ifr. 964 * Return an errno or 0. 965 */ 966 static int 967 bpf_setif(d, ifr) 968 struct bpf_d *d; 969 struct ifreq *ifr; 970 { 971 struct bpf_if *bp; 972 int error; 973 struct ifnet *theywant; 974 975 theywant = ifunit(ifr->ifr_name); 976 if (theywant == 0) 977 return ENXIO; 978 979 /* 980 * Look through attached interfaces for the named one. 981 */ 982 mtx_lock(&bpf_mtx); 983 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 984 struct ifnet *ifp = bp->bif_ifp; 985 986 if (ifp == 0 || ifp != theywant) 987 continue; 988 /* skip additional entry */ 989 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 990 continue; 991 992 mtx_unlock(&bpf_mtx); 993 /* 994 * We found the requested interface. 995 * If it's not up, return an error. 996 * Allocate the packet buffers if we need to. 997 * If we're already attached to requested interface, 998 * just flush the buffer. 999 */ 1000 if ((ifp->if_flags & IFF_UP) == 0) 1001 return (ENETDOWN); 1002 1003 if (d->bd_sbuf == 0) { 1004 error = bpf_allocbufs(d); 1005 if (error != 0) 1006 return (error); 1007 } 1008 if (bp != d->bd_bif) { 1009 if (d->bd_bif) 1010 /* 1011 * Detach if attached to something else. 1012 */ 1013 bpf_detachd(d); 1014 1015 bpf_attachd(d, bp); 1016 } 1017 BPFD_LOCK(d); 1018 reset_d(d); 1019 BPFD_UNLOCK(d); 1020 return (0); 1021 } 1022 mtx_unlock(&bpf_mtx); 1023 /* Not found. */ 1024 return (ENXIO); 1025 } 1026 1027 /* 1028 * Support for select() and poll() system calls 1029 * 1030 * Return true iff the specific operation will not block indefinitely. 1031 * Otherwise, return false but make a note that a selwakeup() must be done. 1032 */ 1033 static int 1034 bpfpoll(dev, events, td) 1035 dev_t dev; 1036 int events; 1037 struct thread *td; 1038 { 1039 struct bpf_d *d; 1040 int revents; 1041 1042 d = dev->si_drv1; 1043 if (d->bd_bif == NULL) 1044 return (ENXIO); 1045 1046 revents = events & (POLLOUT | POLLWRNORM); 1047 BPFD_LOCK(d); 1048 if (events & (POLLIN | POLLRDNORM)) { 1049 /* 1050 * An imitation of the FIONREAD ioctl code. 1051 * XXX not quite. An exact imitation: 1052 * if (d->b_slen != 0 || 1053 * (d->bd_hbuf != NULL && d->bd_hlen != 0) 1054 */ 1055 if (d->bd_hlen != 0 || 1056 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1057 d->bd_slen != 0)) 1058 revents |= events & (POLLIN | POLLRDNORM); 1059 else { 1060 selrecord(td, &d->bd_sel); 1061 /* Start the read timeout if necessary. */ 1062 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1063 callout_reset(&d->bd_callout, d->bd_rtout, 1064 bpf_timed_out, d); 1065 d->bd_state = BPF_WAITING; 1066 } 1067 } 1068 } 1069 BPFD_UNLOCK(d); 1070 return (revents); 1071 } 1072 1073 /* 1074 * Incoming linkage from device drivers. Process the packet pkt, of length 1075 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1076 * by each process' filter, and if accepted, stashed into the corresponding 1077 * buffer. 1078 */ 1079 void 1080 bpf_tap(bp, pkt, pktlen) 1081 struct bpf_if *bp; 1082 u_char *pkt; 1083 u_int pktlen; 1084 { 1085 struct bpf_d *d; 1086 u_int slen; 1087 1088 BPFIF_LOCK(bp); 1089 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1090 BPFD_LOCK(d); 1091 ++d->bd_rcount; 1092 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1093 if (slen != 0) { 1094 #ifdef MAC 1095 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1096 #endif 1097 catchpacket(d, pkt, pktlen, slen, bcopy); 1098 } 1099 BPFD_UNLOCK(d); 1100 } 1101 BPFIF_UNLOCK(bp); 1102 } 1103 1104 /* 1105 * Copy data from an mbuf chain into a buffer. This code is derived 1106 * from m_copydata in sys/uipc_mbuf.c. 1107 */ 1108 static void 1109 bpf_mcopy(src_arg, dst_arg, len) 1110 const void *src_arg; 1111 void *dst_arg; 1112 size_t len; 1113 { 1114 const struct mbuf *m; 1115 u_int count; 1116 u_char *dst; 1117 1118 m = src_arg; 1119 dst = dst_arg; 1120 while (len > 0) { 1121 if (m == 0) 1122 panic("bpf_mcopy"); 1123 count = min(m->m_len, len); 1124 bcopy(mtod(m, void *), dst, count); 1125 m = m->m_next; 1126 dst += count; 1127 len -= count; 1128 } 1129 } 1130 1131 /* 1132 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1133 */ 1134 void 1135 bpf_mtap(bp, m) 1136 struct bpf_if *bp; 1137 struct mbuf *m; 1138 { 1139 struct bpf_d *d; 1140 u_int pktlen, slen; 1141 1142 pktlen = m_length(m, NULL); 1143 if (pktlen == m->m_len) { 1144 bpf_tap(bp, mtod(m, u_char *), pktlen); 1145 return; 1146 } 1147 1148 BPFIF_LOCK(bp); 1149 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1150 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1151 continue; 1152 BPFD_LOCK(d); 1153 ++d->bd_rcount; 1154 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1155 if (slen != 0) 1156 #ifdef MAC 1157 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1158 #endif 1159 catchpacket(d, (u_char *)m, pktlen, slen, 1160 bpf_mcopy); 1161 BPFD_UNLOCK(d); 1162 } 1163 BPFIF_UNLOCK(bp); 1164 } 1165 1166 /* 1167 * Move the packet data from interface memory (pkt) into the 1168 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1169 * otherwise 0. "copy" is the routine called to do the actual data 1170 * transfer. bcopy is passed in to copy contiguous chunks, while 1171 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1172 * pkt is really an mbuf. 1173 */ 1174 static void 1175 catchpacket(d, pkt, pktlen, snaplen, cpfn) 1176 struct bpf_d *d; 1177 u_char *pkt; 1178 u_int pktlen, snaplen; 1179 void (*cpfn)(const void *, void *, size_t); 1180 { 1181 struct bpf_hdr *hp; 1182 int totlen, curlen; 1183 int hdrlen = d->bd_bif->bif_hdrlen; 1184 /* 1185 * Figure out how many bytes to move. If the packet is 1186 * greater or equal to the snapshot length, transfer that 1187 * much. Otherwise, transfer the whole packet (unless 1188 * we hit the buffer size limit). 1189 */ 1190 totlen = hdrlen + min(snaplen, pktlen); 1191 if (totlen > d->bd_bufsize) 1192 totlen = d->bd_bufsize; 1193 1194 /* 1195 * Round up the end of the previous packet to the next longword. 1196 */ 1197 curlen = BPF_WORDALIGN(d->bd_slen); 1198 if (curlen + totlen > d->bd_bufsize) { 1199 /* 1200 * This packet will overflow the storage buffer. 1201 * Rotate the buffers if we can, then wakeup any 1202 * pending reads. 1203 */ 1204 if (d->bd_fbuf == 0) { 1205 /* 1206 * We haven't completed the previous read yet, 1207 * so drop the packet. 1208 */ 1209 ++d->bd_dcount; 1210 return; 1211 } 1212 ROTATE_BUFFERS(d); 1213 bpf_wakeup(d); 1214 curlen = 0; 1215 } 1216 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1217 /* 1218 * Immediate mode is set, or the read timeout has 1219 * already expired during a select call. A packet 1220 * arrived, so the reader should be woken up. 1221 */ 1222 bpf_wakeup(d); 1223 1224 /* 1225 * Append the bpf header. 1226 */ 1227 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1228 microtime(&hp->bh_tstamp); 1229 hp->bh_datalen = pktlen; 1230 hp->bh_hdrlen = hdrlen; 1231 /* 1232 * Copy the packet data into the store buffer and update its length. 1233 */ 1234 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1235 d->bd_slen = curlen + totlen; 1236 } 1237 1238 /* 1239 * Initialize all nonzero fields of a descriptor. 1240 */ 1241 static int 1242 bpf_allocbufs(d) 1243 struct bpf_d *d; 1244 { 1245 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1246 if (d->bd_fbuf == 0) 1247 return (ENOBUFS); 1248 1249 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1250 if (d->bd_sbuf == 0) { 1251 free(d->bd_fbuf, M_BPF); 1252 return (ENOBUFS); 1253 } 1254 d->bd_slen = 0; 1255 d->bd_hlen = 0; 1256 return (0); 1257 } 1258 1259 /* 1260 * Free buffers currently in use by a descriptor. 1261 * Called on close. 1262 */ 1263 static void 1264 bpf_freed(d) 1265 struct bpf_d *d; 1266 { 1267 /* 1268 * We don't need to lock out interrupts since this descriptor has 1269 * been detached from its interface and it yet hasn't been marked 1270 * free. 1271 */ 1272 if (d->bd_sbuf != 0) { 1273 free(d->bd_sbuf, M_BPF); 1274 if (d->bd_hbuf != 0) 1275 free(d->bd_hbuf, M_BPF); 1276 if (d->bd_fbuf != 0) 1277 free(d->bd_fbuf, M_BPF); 1278 } 1279 if (d->bd_filter) 1280 free((caddr_t)d->bd_filter, M_BPF); 1281 mtx_destroy(&d->bd_mtx); 1282 } 1283 1284 /* 1285 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1286 * fixed size of the link header (variable length headers not yet supported). 1287 */ 1288 void 1289 bpfattach(ifp, dlt, hdrlen) 1290 struct ifnet *ifp; 1291 u_int dlt, hdrlen; 1292 { 1293 1294 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1295 } 1296 1297 /* 1298 * Attach an interface to bpf. ifp is a pointer to the structure 1299 * defining the interface to be attached, dlt is the link layer type, 1300 * and hdrlen is the fixed size of the link header (variable length 1301 * headers are not yet supporrted). 1302 */ 1303 void 1304 bpfattach2(ifp, dlt, hdrlen, driverp) 1305 struct ifnet *ifp; 1306 u_int dlt, hdrlen; 1307 struct bpf_if **driverp; 1308 { 1309 struct bpf_if *bp; 1310 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1311 if (bp == 0) 1312 panic("bpfattach"); 1313 1314 bp->bif_dlist = 0; 1315 bp->bif_driverp = driverp; 1316 bp->bif_ifp = ifp; 1317 bp->bif_dlt = dlt; 1318 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1319 1320 mtx_lock(&bpf_mtx); 1321 bp->bif_next = bpf_iflist; 1322 bpf_iflist = bp; 1323 mtx_unlock(&bpf_mtx); 1324 1325 *bp->bif_driverp = 0; 1326 1327 /* 1328 * Compute the length of the bpf header. This is not necessarily 1329 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1330 * that the network layer header begins on a longword boundary (for 1331 * performance reasons and to alleviate alignment restrictions). 1332 */ 1333 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1334 1335 if (bootverbose) 1336 if_printf(ifp, "bpf attached\n"); 1337 } 1338 1339 /* 1340 * Detach bpf from an interface. This involves detaching each descriptor 1341 * associated with the interface, and leaving bd_bif NULL. Notify each 1342 * descriptor as it's detached so that any sleepers wake up and get 1343 * ENXIO. 1344 */ 1345 void 1346 bpfdetach(ifp) 1347 struct ifnet *ifp; 1348 { 1349 struct bpf_if *bp, *bp_prev; 1350 struct bpf_d *d; 1351 1352 /* Locate BPF interface information */ 1353 bp_prev = NULL; 1354 1355 mtx_lock(&bpf_mtx); 1356 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1357 if (ifp == bp->bif_ifp) 1358 break; 1359 bp_prev = bp; 1360 } 1361 1362 /* Interface wasn't attached */ 1363 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1364 mtx_unlock(&bpf_mtx); 1365 printf("bpfdetach: %s%d was not attached\n", ifp->if_name, 1366 ifp->if_unit); 1367 return; 1368 } 1369 1370 if (bp_prev) { 1371 bp_prev->bif_next = bp->bif_next; 1372 } else { 1373 bpf_iflist = bp->bif_next; 1374 } 1375 mtx_unlock(&bpf_mtx); 1376 1377 while ((d = bp->bif_dlist) != NULL) { 1378 bpf_detachd(d); 1379 BPFD_LOCK(d); 1380 bpf_wakeup(d); 1381 BPFD_UNLOCK(d); 1382 } 1383 1384 mtx_destroy(&bp->bif_mtx); 1385 free(bp, M_BPF); 1386 } 1387 1388 /* 1389 * Get a list of available data link type of the interface. 1390 */ 1391 static int 1392 bpf_getdltlist(d, bfl) 1393 struct bpf_d *d; 1394 struct bpf_dltlist *bfl; 1395 { 1396 int n, error; 1397 struct ifnet *ifp; 1398 struct bpf_if *bp; 1399 1400 ifp = d->bd_bif->bif_ifp; 1401 n = 0; 1402 error = 0; 1403 mtx_lock(&bpf_mtx); 1404 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1405 if (bp->bif_ifp != ifp) 1406 continue; 1407 if (bfl->bfl_list != NULL) { 1408 if (n >= bfl->bfl_len) { 1409 mtx_unlock(&bpf_mtx); 1410 return (ENOMEM); 1411 } 1412 error = copyout(&bp->bif_dlt, 1413 bfl->bfl_list + n, sizeof(u_int)); 1414 } 1415 n++; 1416 } 1417 mtx_unlock(&bpf_mtx); 1418 bfl->bfl_len = n; 1419 return (error); 1420 } 1421 1422 /* 1423 * Set the data link type of a BPF instance. 1424 */ 1425 static int 1426 bpf_setdlt(d, dlt) 1427 struct bpf_d *d; 1428 u_int dlt; 1429 { 1430 int error, opromisc; 1431 struct ifnet *ifp; 1432 struct bpf_if *bp; 1433 1434 if (d->bd_bif->bif_dlt == dlt) 1435 return (0); 1436 ifp = d->bd_bif->bif_ifp; 1437 mtx_lock(&bpf_mtx); 1438 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1439 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1440 break; 1441 } 1442 mtx_unlock(&bpf_mtx); 1443 if (bp != NULL) { 1444 BPFD_LOCK(d); 1445 opromisc = d->bd_promisc; 1446 bpf_detachd(d); 1447 bpf_attachd(d, bp); 1448 reset_d(d); 1449 BPFD_UNLOCK(d); 1450 if (opromisc) { 1451 error = ifpromisc(bp->bif_ifp, 1); 1452 if (error) 1453 if_printf(bp->bif_ifp, 1454 "bpf_setdlt: ifpromisc failed (%d)\n", 1455 error); 1456 else 1457 d->bd_promisc = 1; 1458 } 1459 } 1460 return (bp == NULL ? EINVAL : 0); 1461 } 1462 1463 static void bpf_drvinit(void *unused); 1464 1465 static void bpf_clone(void *arg, char *name, int namelen, dev_t *dev); 1466 1467 static void 1468 bpf_clone(arg, name, namelen, dev) 1469 void *arg; 1470 char *name; 1471 int namelen; 1472 dev_t *dev; 1473 { 1474 int u; 1475 1476 if (*dev != NODEV) 1477 return; 1478 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1479 return; 1480 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1481 "bpf%d", u); 1482 (*dev)->si_flags |= SI_CHEAPCLONE; 1483 return; 1484 } 1485 1486 static void 1487 bpf_drvinit(unused) 1488 void *unused; 1489 { 1490 1491 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1492 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1493 } 1494 1495 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1496 1497 #else /* !DEV_BPF && !NETGRAPH_BPF */ 1498 /* 1499 * NOP stubs to allow bpf-using drivers to load and function. 1500 * 1501 * A 'better' implementation would allow the core bpf functionality 1502 * to be loaded at runtime. 1503 */ 1504 1505 void 1506 bpf_tap(bp, pkt, pktlen) 1507 struct bpf_if *bp; 1508 u_char *pkt; 1509 u_int pktlen; 1510 { 1511 } 1512 1513 void 1514 bpf_mtap(bp, m) 1515 struct bpf_if *bp; 1516 struct mbuf *m; 1517 { 1518 } 1519 1520 void 1521 bpfattach(ifp, dlt, hdrlen) 1522 struct ifnet *ifp; 1523 u_int dlt, hdrlen; 1524 { 1525 } 1526 1527 void 1528 bpfdetach(ifp) 1529 struct ifnet *ifp; 1530 { 1531 } 1532 1533 u_int 1534 bpf_filter(pc, p, wirelen, buflen) 1535 const struct bpf_insn *pc; 1536 u_char *p; 1537 u_int wirelen; 1538 u_int buflen; 1539 { 1540 return -1; /* "no filter" behaviour */ 1541 } 1542 1543 int 1544 bpf_validate(f, len) 1545 const struct bpf_insn *f; 1546 int len; 1547 { 1548 return 0; /* false */ 1549 } 1550 1551 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 1552