bpf.c revision 142787
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 * $FreeBSD: head/sys/net/bpf.c 142787 2005-02-28 12:35:52Z rwatson $ 37 */ 38 39#include "opt_bpf.h" 40#include "opt_mac.h" 41#include "opt_netgraph.h" 42 43#include <sys/types.h> 44#include <sys/param.h> 45#include <sys/systm.h> 46#include <sys/conf.h> 47#include <sys/fcntl.h> 48#include <sys/mac.h> 49#include <sys/malloc.h> 50#include <sys/mbuf.h> 51#include <sys/time.h> 52#include <sys/proc.h> 53#include <sys/signalvar.h> 54#include <sys/filio.h> 55#include <sys/sockio.h> 56#include <sys/ttycom.h> 57#include <sys/uio.h> 58 59#include <sys/event.h> 60#include <sys/file.h> 61#include <sys/poll.h> 62#include <sys/proc.h> 63 64#include <sys/socket.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 75static 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 */ 84static int bpf_bufsize = 4096; 85SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 86 &bpf_bufsize, 0, ""); 87static int bpf_maxbufsize = BPF_MAXBUFSIZE; 88SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 89 &bpf_maxbufsize, 0, ""); 90 91/* 92 * bpf_iflist is a list of BPF interface structures, each corresponding to a 93 * specific DLT. The same network interface might have several BPF interface 94 * structures registered by different layers in the stack (i.e., 802.11 95 * frames, ethernet frames, etc). 96 */ 97static LIST_HEAD(, bpf_if) bpf_iflist; 98static struct mtx bpf_mtx; /* bpf global lock */ 99 100static int bpf_allocbufs(struct bpf_d *); 101static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 102static void bpf_detachd(struct bpf_d *d); 103static void bpf_freed(struct bpf_d *); 104static void bpf_mcopy(const void *, void *, size_t); 105static int bpf_movein(struct uio *, int, 106 struct mbuf **, struct sockaddr *, int *); 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, 112 u_int, void (*)(const void *, void *, size_t)); 113static void reset_d(struct bpf_d *); 114static int bpf_setf(struct bpf_d *, struct bpf_program *); 115static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 116static int bpf_setdlt(struct bpf_d *, u_int); 117static void filt_bpfdetach(struct knote *); 118static int filt_bpfread(struct knote *, long); 119 120static d_open_t bpfopen; 121static d_close_t bpfclose; 122static d_read_t bpfread; 123static d_write_t bpfwrite; 124static d_ioctl_t bpfioctl; 125static d_poll_t bpfpoll; 126static d_kqfilter_t bpfkqfilter; 127 128static struct cdevsw bpf_cdevsw = { 129 .d_version = D_VERSION, 130 .d_flags = D_NEEDGIANT, 131 .d_open = bpfopen, 132 .d_close = bpfclose, 133 .d_read = bpfread, 134 .d_write = bpfwrite, 135 .d_ioctl = bpfioctl, 136 .d_poll = bpfpoll, 137 .d_name = "bpf", 138 .d_kqfilter = bpfkqfilter, 139}; 140 141static struct filterops bpfread_filtops = 142 { 1, NULL, filt_bpfdetach, filt_bpfread }; 143 144static int 145bpf_movein(uio, linktype, mp, sockp, datlen) 146 struct uio *uio; 147 int linktype, *datlen; 148 struct mbuf **mp; 149 struct sockaddr *sockp; 150{ 151 struct mbuf *m; 152 int error; 153 int len; 154 int hlen; 155 156 /* 157 * Build a sockaddr based on the data link layer type. 158 * We do this at this level because the ethernet header 159 * is copied directly into the data field of the sockaddr. 160 * In the case of SLIP, there is no header and the packet 161 * is forwarded as is. 162 * Also, we are careful to leave room at the front of the mbuf 163 * for the link level header. 164 */ 165 switch (linktype) { 166 167 case DLT_SLIP: 168 sockp->sa_family = AF_INET; 169 hlen = 0; 170 break; 171 172 case DLT_EN10MB: 173 sockp->sa_family = AF_UNSPEC; 174 /* XXX Would MAXLINKHDR be better? */ 175 hlen = ETHER_HDR_LEN; 176 break; 177 178 case DLT_FDDI: 179 sockp->sa_family = AF_IMPLINK; 180 hlen = 0; 181 break; 182 183 case DLT_RAW: 184 case DLT_NULL: 185 sockp->sa_family = AF_UNSPEC; 186 hlen = 0; 187 break; 188 189 case DLT_ATM_RFC1483: 190 /* 191 * en atm driver requires 4-byte atm pseudo header. 192 * though it isn't standard, vpi:vci needs to be 193 * specified anyway. 194 */ 195 sockp->sa_family = AF_UNSPEC; 196 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 197 break; 198 199 case DLT_PPP: 200 sockp->sa_family = AF_UNSPEC; 201 hlen = 4; /* This should match PPP_HDRLEN */ 202 break; 203 204 default: 205 return (EIO); 206 } 207 208 len = uio->uio_resid; 209 *datlen = len - hlen; 210 if ((unsigned)len > MCLBYTES) 211 return (EIO); 212 213 if (len > MHLEN) { 214 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 215 } else { 216 MGETHDR(m, M_TRYWAIT, MT_DATA); 217 } 218 if (m == NULL) 219 return (ENOBUFS); 220 m->m_pkthdr.len = m->m_len = len; 221 m->m_pkthdr.rcvif = NULL; 222 *mp = m; 223 224 /* 225 * Make room for link header. 226 */ 227 if (hlen != 0) { 228 m->m_pkthdr.len -= hlen; 229 m->m_len -= hlen; 230#if BSD >= 199103 231 m->m_data += hlen; /* XXX */ 232#else 233 m->m_off += hlen; 234#endif 235 error = uiomove(sockp->sa_data, hlen, uio); 236 if (error) 237 goto bad; 238 } 239 error = uiomove(mtod(m, void *), len - hlen, uio); 240 if (!error) 241 return (0); 242bad: 243 m_freem(m); 244 return (error); 245} 246 247/* 248 * Attach file to the bpf interface, i.e. make d listen on bp. 249 */ 250static void 251bpf_attachd(d, bp) 252 struct bpf_d *d; 253 struct bpf_if *bp; 254{ 255 /* 256 * Point d at bp, and add d to the interface's list of listeners. 257 * Finally, point the driver's bpf cookie at the interface so 258 * it will divert packets to bpf. 259 */ 260 BPFIF_LOCK(bp); 261 d->bd_bif = bp; 262 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 263 264 *bp->bif_driverp = bp; 265 BPFIF_UNLOCK(bp); 266} 267 268/* 269 * Detach a file from its interface. 270 */ 271static void 272bpf_detachd(d) 273 struct bpf_d *d; 274{ 275 int error; 276 struct bpf_if *bp; 277 struct ifnet *ifp; 278 279 bp = d->bd_bif; 280 BPFIF_LOCK(bp); 281 BPFD_LOCK(d); 282 ifp = d->bd_bif->bif_ifp; 283 284 /* 285 * Remove d from the interface's descriptor list. 286 */ 287 LIST_REMOVE(d, bd_next); 288 289 /* 290 * Let the driver know that there are no more listeners. 291 */ 292 if (LIST_EMPTY(&bp->bif_dlist)) 293 *bp->bif_driverp = NULL; 294 295 d->bd_bif = NULL; 296 BPFD_UNLOCK(d); 297 BPFIF_UNLOCK(bp); 298 299 /* 300 * Check if this descriptor had requested promiscuous mode. 301 * If so, turn it off. 302 */ 303 if (d->bd_promisc) { 304 d->bd_promisc = 0; 305 error = ifpromisc(ifp, 0); 306 if (error != 0 && error != ENXIO) { 307 /* 308 * ENXIO can happen if a pccard is unplugged 309 * Something is really wrong if we were able to put 310 * the driver into promiscuous mode, but can't 311 * take it out. 312 */ 313 if_printf(bp->bif_ifp, 314 "bpf_detach: ifpromisc failed (%d)\n", error); 315 } 316 } 317} 318 319/* 320 * Open ethernet device. Returns ENXIO for illegal minor device number, 321 * EBUSY if file is open by another process. 322 */ 323/* ARGSUSED */ 324static int 325bpfopen(dev, flags, fmt, td) 326 struct cdev *dev; 327 int flags; 328 int fmt; 329 struct thread *td; 330{ 331 struct bpf_d *d; 332 333 mtx_lock(&bpf_mtx); 334 d = dev->si_drv1; 335 /* 336 * Each minor can be opened by only one process. If the requested 337 * minor is in use, return EBUSY. 338 */ 339 if (d != NULL) { 340 mtx_unlock(&bpf_mtx); 341 return (EBUSY); 342 } 343 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 344 mtx_unlock(&bpf_mtx); 345 346 if ((dev->si_flags & SI_NAMED) == 0) 347 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 348 "bpf%d", dev2unit(dev)); 349 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 350 dev->si_drv1 = d; 351 d->bd_bufsize = bpf_bufsize; 352 d->bd_sig = SIGIO; 353 d->bd_seesent = 1; 354#ifdef MAC 355 mac_init_bpfdesc(d); 356 mac_create_bpfdesc(td->td_ucred, d); 357#endif 358 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 359 callout_init(&d->bd_callout, debug_mpsafenet ? CALLOUT_MPSAFE : 0); 360 knlist_init(&d->bd_sel.si_note, &d->bd_mtx); 361 362 return (0); 363} 364 365/* 366 * Close the descriptor by detaching it from its interface, 367 * deallocating its buffers, and marking it free. 368 */ 369/* ARGSUSED */ 370static int 371bpfclose(dev, flags, fmt, td) 372 struct cdev *dev; 373 int flags; 374 int fmt; 375 struct thread *td; 376{ 377 struct bpf_d *d = dev->si_drv1; 378 379 BPFD_LOCK(d); 380 if (d->bd_state == BPF_WAITING) 381 callout_stop(&d->bd_callout); 382 d->bd_state = BPF_IDLE; 383 BPFD_UNLOCK(d); 384 funsetown(&d->bd_sigio); 385 mtx_lock(&bpf_mtx); 386 if (d->bd_bif) 387 bpf_detachd(d); 388 mtx_unlock(&bpf_mtx); 389#ifdef MAC 390 mac_destroy_bpfdesc(d); 391#endif /* MAC */ 392 knlist_destroy(&d->bd_sel.si_note); 393 bpf_freed(d); 394 dev->si_drv1 = NULL; 395 free(d, M_BPF); 396 397 return (0); 398} 399 400 401/* 402 * Rotate the packet buffers in descriptor d. Move the store buffer 403 * into the hold slot, and the free buffer into the store slot. 404 * Zero the length of the new store buffer. 405 */ 406#define ROTATE_BUFFERS(d) \ 407 (d)->bd_hbuf = (d)->bd_sbuf; \ 408 (d)->bd_hlen = (d)->bd_slen; \ 409 (d)->bd_sbuf = (d)->bd_fbuf; \ 410 (d)->bd_slen = 0; \ 411 (d)->bd_fbuf = NULL; 412/* 413 * bpfread - read next chunk of packets from buffers 414 */ 415static int 416bpfread(dev, uio, ioflag) 417 struct cdev *dev; 418 struct uio *uio; 419 int ioflag; 420{ 421 struct bpf_d *d = dev->si_drv1; 422 int timed_out; 423 int error; 424 425 /* 426 * Restrict application to use a buffer the same size as 427 * as kernel buffers. 428 */ 429 if (uio->uio_resid != d->bd_bufsize) 430 return (EINVAL); 431 432 BPFD_LOCK(d); 433 if (d->bd_state == BPF_WAITING) 434 callout_stop(&d->bd_callout); 435 timed_out = (d->bd_state == BPF_TIMED_OUT); 436 d->bd_state = BPF_IDLE; 437 /* 438 * If the hold buffer is empty, then do a timed sleep, which 439 * ends when the timeout expires or when enough packets 440 * have arrived to fill the store buffer. 441 */ 442 while (d->bd_hbuf == NULL) { 443 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 444 /* 445 * A packet(s) either arrived since the previous 446 * read or arrived while we were asleep. 447 * Rotate the buffers and return what's here. 448 */ 449 ROTATE_BUFFERS(d); 450 break; 451 } 452 453 /* 454 * No data is available, check to see if the bpf device 455 * is still pointed at a real interface. If not, return 456 * ENXIO so that the userland process knows to rebind 457 * it before using it again. 458 */ 459 if (d->bd_bif == NULL) { 460 BPFD_UNLOCK(d); 461 return (ENXIO); 462 } 463 464 if (ioflag & O_NONBLOCK) { 465 BPFD_UNLOCK(d); 466 return (EWOULDBLOCK); 467 } 468 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 469 "bpf", d->bd_rtout); 470 if (error == EINTR || error == ERESTART) { 471 BPFD_UNLOCK(d); 472 return (error); 473 } 474 if (error == EWOULDBLOCK) { 475 /* 476 * On a timeout, return what's in the buffer, 477 * which may be nothing. If there is something 478 * in the store buffer, we can rotate the buffers. 479 */ 480 if (d->bd_hbuf) 481 /* 482 * We filled up the buffer in between 483 * getting the timeout and arriving 484 * here, so we don't need to rotate. 485 */ 486 break; 487 488 if (d->bd_slen == 0) { 489 BPFD_UNLOCK(d); 490 return (0); 491 } 492 ROTATE_BUFFERS(d); 493 break; 494 } 495 } 496 /* 497 * At this point, we know we have something in the hold slot. 498 */ 499 BPFD_UNLOCK(d); 500 501 /* 502 * Move data from hold buffer into user space. 503 * We know the entire buffer is transferred since 504 * we checked above that the read buffer is bpf_bufsize bytes. 505 */ 506 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 507 508 BPFD_LOCK(d); 509 d->bd_fbuf = d->bd_hbuf; 510 d->bd_hbuf = NULL; 511 d->bd_hlen = 0; 512 BPFD_UNLOCK(d); 513 514 return (error); 515} 516 517 518/* 519 * If there are processes sleeping on this descriptor, wake them up. 520 */ 521static __inline void 522bpf_wakeup(d) 523 struct bpf_d *d; 524{ 525 if (d->bd_state == BPF_WAITING) { 526 callout_stop(&d->bd_callout); 527 d->bd_state = BPF_IDLE; 528 } 529 wakeup(d); 530 if (d->bd_async && d->bd_sig && d->bd_sigio) 531 pgsigio(&d->bd_sigio, d->bd_sig, 0); 532 533 selwakeuppri(&d->bd_sel, PRINET); 534 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 535} 536 537static void 538bpf_timed_out(arg) 539 void *arg; 540{ 541 struct bpf_d *d = (struct bpf_d *)arg; 542 543 BPFD_LOCK(d); 544 if (d->bd_state == BPF_WAITING) { 545 d->bd_state = BPF_TIMED_OUT; 546 if (d->bd_slen != 0) 547 bpf_wakeup(d); 548 } 549 BPFD_UNLOCK(d); 550} 551 552static int 553bpfwrite(dev, uio, ioflag) 554 struct cdev *dev; 555 struct uio *uio; 556 int ioflag; 557{ 558 struct bpf_d *d = dev->si_drv1; 559 struct ifnet *ifp; 560 struct mbuf *m; 561 int error; 562 struct sockaddr dst; 563 int datlen; 564 565 if (d->bd_bif == NULL) 566 return (ENXIO); 567 568 ifp = d->bd_bif->bif_ifp; 569 570 if ((ifp->if_flags & IFF_UP) == 0) 571 return (ENETDOWN); 572 573 if (uio->uio_resid == 0) 574 return (0); 575 576 bzero(&dst, sizeof(dst)); 577 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 578 if (error) 579 return (error); 580 581 if (datlen > ifp->if_mtu) { 582 m_freem(m); 583 return (EMSGSIZE); 584 } 585 586 if (d->bd_hdrcmplt) 587 dst.sa_family = pseudo_AF_HDRCMPLT; 588 589#ifdef MAC 590 BPFD_LOCK(d); 591 mac_create_mbuf_from_bpfdesc(d, m); 592 BPFD_UNLOCK(d); 593#endif 594 NET_LOCK_GIANT(); 595 error = (*ifp->if_output)(ifp, m, &dst, NULL); 596 NET_UNLOCK_GIANT(); 597 /* 598 * The driver frees the mbuf. 599 */ 600 return (error); 601} 602 603/* 604 * Reset a descriptor by flushing its packet buffer and clearing the 605 * receive and drop counts. 606 */ 607static void 608reset_d(d) 609 struct bpf_d *d; 610{ 611 612 mtx_assert(&d->bd_mtx, MA_OWNED); 613 if (d->bd_hbuf) { 614 /* Free the hold buffer. */ 615 d->bd_fbuf = d->bd_hbuf; 616 d->bd_hbuf = NULL; 617 } 618 d->bd_slen = 0; 619 d->bd_hlen = 0; 620 d->bd_rcount = 0; 621 d->bd_dcount = 0; 622} 623 624/* 625 * FIONREAD Check for read packet available. 626 * SIOCGIFADDR Get interface address - convenient hook to driver. 627 * BIOCGBLEN Get buffer len [for read()]. 628 * BIOCSETF Set ethernet read filter. 629 * BIOCFLUSH Flush read packet buffer. 630 * BIOCPROMISC Put interface into promiscuous mode. 631 * BIOCGDLT Get link layer type. 632 * BIOCGETIF Get interface name. 633 * BIOCSETIF Set interface. 634 * BIOCSRTIMEOUT Set read timeout. 635 * BIOCGRTIMEOUT Get read timeout. 636 * BIOCGSTATS Get packet stats. 637 * BIOCIMMEDIATE Set immediate mode. 638 * BIOCVERSION Get filter language version. 639 * BIOCGHDRCMPLT Get "header already complete" flag 640 * BIOCSHDRCMPLT Set "header already complete" flag 641 * BIOCGSEESENT Get "see packets sent" flag 642 * BIOCSSEESENT Set "see packets sent" flag 643 */ 644/* ARGSUSED */ 645static int 646bpfioctl(dev, cmd, addr, flags, td) 647 struct cdev *dev; 648 u_long cmd; 649 caddr_t addr; 650 int flags; 651 struct thread *td; 652{ 653 struct bpf_d *d = dev->si_drv1; 654 int error = 0; 655 656 BPFD_LOCK(d); 657 if (d->bd_state == BPF_WAITING) 658 callout_stop(&d->bd_callout); 659 d->bd_state = BPF_IDLE; 660 BPFD_UNLOCK(d); 661 662 switch (cmd) { 663 664 default: 665 error = EINVAL; 666 break; 667 668 /* 669 * Check for read packet available. 670 */ 671 case FIONREAD: 672 { 673 int n; 674 675 BPFD_LOCK(d); 676 n = d->bd_slen; 677 if (d->bd_hbuf) 678 n += d->bd_hlen; 679 BPFD_UNLOCK(d); 680 681 *(int *)addr = n; 682 break; 683 } 684 685 case SIOCGIFADDR: 686 { 687 struct ifnet *ifp; 688 689 if (d->bd_bif == NULL) 690 error = EINVAL; 691 else { 692 ifp = d->bd_bif->bif_ifp; 693 error = (*ifp->if_ioctl)(ifp, cmd, addr); 694 } 695 break; 696 } 697 698 /* 699 * Get buffer len [for read()]. 700 */ 701 case BIOCGBLEN: 702 *(u_int *)addr = d->bd_bufsize; 703 break; 704 705 /* 706 * Set buffer length. 707 */ 708 case BIOCSBLEN: 709 if (d->bd_bif != NULL) 710 error = EINVAL; 711 else { 712 u_int size = *(u_int *)addr; 713 714 if (size > bpf_maxbufsize) 715 *(u_int *)addr = size = bpf_maxbufsize; 716 else if (size < BPF_MINBUFSIZE) 717 *(u_int *)addr = size = BPF_MINBUFSIZE; 718 d->bd_bufsize = size; 719 } 720 break; 721 722 /* 723 * Set link layer read filter. 724 */ 725 case BIOCSETF: 726 error = bpf_setf(d, (struct bpf_program *)addr); 727 break; 728 729 /* 730 * Flush read packet buffer. 731 */ 732 case BIOCFLUSH: 733 BPFD_LOCK(d); 734 reset_d(d); 735 BPFD_UNLOCK(d); 736 break; 737 738 /* 739 * Put interface into promiscuous mode. 740 */ 741 case BIOCPROMISC: 742 if (d->bd_bif == NULL) { 743 /* 744 * No interface attached yet. 745 */ 746 error = EINVAL; 747 break; 748 } 749 if (d->bd_promisc == 0) { 750 mtx_lock(&Giant); 751 error = ifpromisc(d->bd_bif->bif_ifp, 1); 752 mtx_unlock(&Giant); 753 if (error == 0) 754 d->bd_promisc = 1; 755 } 756 break; 757 758 /* 759 * Get current data link type. 760 */ 761 case BIOCGDLT: 762 if (d->bd_bif == NULL) 763 error = EINVAL; 764 else 765 *(u_int *)addr = d->bd_bif->bif_dlt; 766 break; 767 768 /* 769 * Get a list of supported data link types. 770 */ 771 case BIOCGDLTLIST: 772 if (d->bd_bif == NULL) 773 error = EINVAL; 774 else 775 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 776 break; 777 778 /* 779 * Set data link type. 780 */ 781 case BIOCSDLT: 782 if (d->bd_bif == NULL) 783 error = EINVAL; 784 else 785 error = bpf_setdlt(d, *(u_int *)addr); 786 break; 787 788 /* 789 * Get interface name. 790 */ 791 case BIOCGETIF: 792 if (d->bd_bif == NULL) 793 error = EINVAL; 794 else { 795 struct ifnet *const ifp = d->bd_bif->bif_ifp; 796 struct ifreq *const ifr = (struct ifreq *)addr; 797 798 strlcpy(ifr->ifr_name, ifp->if_xname, 799 sizeof(ifr->ifr_name)); 800 } 801 break; 802 803 /* 804 * Set interface. 805 */ 806 case BIOCSETIF: 807 error = bpf_setif(d, (struct ifreq *)addr); 808 break; 809 810 /* 811 * Set read timeout. 812 */ 813 case BIOCSRTIMEOUT: 814 { 815 struct timeval *tv = (struct timeval *)addr; 816 817 /* 818 * Subtract 1 tick from tvtohz() since this isn't 819 * a one-shot timer. 820 */ 821 if ((error = itimerfix(tv)) == 0) 822 d->bd_rtout = tvtohz(tv) - 1; 823 break; 824 } 825 826 /* 827 * Get read timeout. 828 */ 829 case BIOCGRTIMEOUT: 830 { 831 struct timeval *tv = (struct timeval *)addr; 832 833 tv->tv_sec = d->bd_rtout / hz; 834 tv->tv_usec = (d->bd_rtout % hz) * tick; 835 break; 836 } 837 838 /* 839 * Get packet stats. 840 */ 841 case BIOCGSTATS: 842 { 843 struct bpf_stat *bs = (struct bpf_stat *)addr; 844 845 bs->bs_recv = d->bd_rcount; 846 bs->bs_drop = d->bd_dcount; 847 break; 848 } 849 850 /* 851 * Set immediate mode. 852 */ 853 case BIOCIMMEDIATE: 854 d->bd_immediate = *(u_int *)addr; 855 break; 856 857 case BIOCVERSION: 858 { 859 struct bpf_version *bv = (struct bpf_version *)addr; 860 861 bv->bv_major = BPF_MAJOR_VERSION; 862 bv->bv_minor = BPF_MINOR_VERSION; 863 break; 864 } 865 866 /* 867 * Get "header already complete" flag 868 */ 869 case BIOCGHDRCMPLT: 870 *(u_int *)addr = d->bd_hdrcmplt; 871 break; 872 873 /* 874 * Set "header already complete" flag 875 */ 876 case BIOCSHDRCMPLT: 877 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 878 break; 879 880 /* 881 * Get "see sent packets" flag 882 */ 883 case BIOCGSEESENT: 884 *(u_int *)addr = d->bd_seesent; 885 break; 886 887 /* 888 * Set "see sent packets" flag 889 */ 890 case BIOCSSEESENT: 891 d->bd_seesent = *(u_int *)addr; 892 break; 893 894 case FIONBIO: /* Non-blocking I/O */ 895 break; 896 897 case FIOASYNC: /* Send signal on receive packets */ 898 d->bd_async = *(int *)addr; 899 break; 900 901 case FIOSETOWN: 902 error = fsetown(*(int *)addr, &d->bd_sigio); 903 break; 904 905 case FIOGETOWN: 906 *(int *)addr = fgetown(&d->bd_sigio); 907 break; 908 909 /* This is deprecated, FIOSETOWN should be used instead. */ 910 case TIOCSPGRP: 911 error = fsetown(-(*(int *)addr), &d->bd_sigio); 912 break; 913 914 /* This is deprecated, FIOGETOWN should be used instead. */ 915 case TIOCGPGRP: 916 *(int *)addr = -fgetown(&d->bd_sigio); 917 break; 918 919 case BIOCSRSIG: /* Set receive signal */ 920 { 921 u_int sig; 922 923 sig = *(u_int *)addr; 924 925 if (sig >= NSIG) 926 error = EINVAL; 927 else 928 d->bd_sig = sig; 929 break; 930 } 931 case BIOCGRSIG: 932 *(u_int *)addr = d->bd_sig; 933 break; 934 } 935 return (error); 936} 937 938/* 939 * Set d's packet filter program to fp. If this file already has a filter, 940 * free it and replace it. Returns EINVAL for bogus requests. 941 */ 942static int 943bpf_setf(d, fp) 944 struct bpf_d *d; 945 struct bpf_program *fp; 946{ 947 struct bpf_insn *fcode, *old; 948 u_int flen, size; 949 950 old = d->bd_filter; 951 if (fp->bf_insns == NULL) { 952 if (fp->bf_len != 0) 953 return (EINVAL); 954 BPFD_LOCK(d); 955 d->bd_filter = NULL; 956 reset_d(d); 957 BPFD_UNLOCK(d); 958 if (old != NULL) 959 free((caddr_t)old, M_BPF); 960 return (0); 961 } 962 flen = fp->bf_len; 963 if (flen > BPF_MAXINSNS) 964 return (EINVAL); 965 966 size = flen * sizeof(*fp->bf_insns); 967 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 968 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 969 bpf_validate(fcode, (int)flen)) { 970 BPFD_LOCK(d); 971 d->bd_filter = fcode; 972 reset_d(d); 973 BPFD_UNLOCK(d); 974 if (old != NULL) 975 free((caddr_t)old, M_BPF); 976 977 return (0); 978 } 979 free((caddr_t)fcode, M_BPF); 980 return (EINVAL); 981} 982 983/* 984 * Detach a file from its current interface (if attached at all) and attach 985 * to the interface indicated by the name stored in ifr. 986 * Return an errno or 0. 987 */ 988static int 989bpf_setif(d, ifr) 990 struct bpf_d *d; 991 struct ifreq *ifr; 992{ 993 struct bpf_if *bp; 994 int error; 995 struct ifnet *theywant; 996 997 theywant = ifunit(ifr->ifr_name); 998 if (theywant == NULL) 999 return ENXIO; 1000 1001 /* 1002 * Look through attached interfaces for the named one. 1003 */ 1004 mtx_lock(&bpf_mtx); 1005 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1006 struct ifnet *ifp = bp->bif_ifp; 1007 1008 if (ifp == NULL || ifp != theywant) 1009 continue; 1010 /* skip additional entry */ 1011 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 1012 continue; 1013 1014 mtx_unlock(&bpf_mtx); 1015 /* 1016 * We found the requested interface. 1017 * Allocate the packet buffers if we need to. 1018 * If we're already attached to requested interface, 1019 * just flush the buffer. 1020 */ 1021 if (d->bd_sbuf == NULL) { 1022 error = bpf_allocbufs(d); 1023 if (error != 0) 1024 return (error); 1025 } 1026 if (bp != d->bd_bif) { 1027 if (d->bd_bif) 1028 /* 1029 * Detach if attached to something else. 1030 */ 1031 bpf_detachd(d); 1032 1033 bpf_attachd(d, bp); 1034 } 1035 BPFD_LOCK(d); 1036 reset_d(d); 1037 BPFD_UNLOCK(d); 1038 return (0); 1039 } 1040 mtx_unlock(&bpf_mtx); 1041 /* Not found. */ 1042 return (ENXIO); 1043} 1044 1045/* 1046 * Support for select() and poll() system calls 1047 * 1048 * Return true iff the specific operation will not block indefinitely. 1049 * Otherwise, return false but make a note that a selwakeup() must be done. 1050 */ 1051static int 1052bpfpoll(dev, events, td) 1053 struct cdev *dev; 1054 int events; 1055 struct thread *td; 1056{ 1057 struct bpf_d *d; 1058 int revents; 1059 1060 d = dev->si_drv1; 1061 if (d->bd_bif == NULL) 1062 return (ENXIO); 1063 1064 revents = events & (POLLOUT | POLLWRNORM); 1065 BPFD_LOCK(d); 1066 if (events & (POLLIN | POLLRDNORM)) { 1067 if (bpf_ready(d)) 1068 revents |= events & (POLLIN | POLLRDNORM); 1069 else { 1070 selrecord(td, &d->bd_sel); 1071 /* Start the read timeout if necessary. */ 1072 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1073 callout_reset(&d->bd_callout, d->bd_rtout, 1074 bpf_timed_out, d); 1075 d->bd_state = BPF_WAITING; 1076 } 1077 } 1078 } 1079 BPFD_UNLOCK(d); 1080 return (revents); 1081} 1082 1083/* 1084 * Support for kevent() system call. Register EVFILT_READ filters and 1085 * reject all others. 1086 */ 1087int 1088bpfkqfilter(dev, kn) 1089 struct cdev *dev; 1090 struct knote *kn; 1091{ 1092 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1093 1094 if (kn->kn_filter != EVFILT_READ) 1095 return (1); 1096 1097 kn->kn_fop = &bpfread_filtops; 1098 kn->kn_hook = d; 1099 knlist_add(&d->bd_sel.si_note, kn, 0); 1100 1101 return (0); 1102} 1103 1104static void 1105filt_bpfdetach(kn) 1106 struct knote *kn; 1107{ 1108 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1109 1110 knlist_remove(&d->bd_sel.si_note, kn, 0); 1111} 1112 1113static int 1114filt_bpfread(kn, hint) 1115 struct knote *kn; 1116 long hint; 1117{ 1118 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1119 int ready; 1120 1121 BPFD_LOCK_ASSERT(d); 1122 ready = bpf_ready(d); 1123 if (ready) { 1124 kn->kn_data = d->bd_slen; 1125 if (d->bd_hbuf) 1126 kn->kn_data += d->bd_hlen; 1127 } 1128 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1129 callout_reset(&d->bd_callout, d->bd_rtout, 1130 bpf_timed_out, d); 1131 d->bd_state = BPF_WAITING; 1132 } 1133 1134 return (ready); 1135} 1136 1137/* 1138 * Incoming linkage from device drivers. Process the packet pkt, of length 1139 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1140 * by each process' filter, and if accepted, stashed into the corresponding 1141 * buffer. 1142 */ 1143void 1144bpf_tap(bp, pkt, pktlen) 1145 struct bpf_if *bp; 1146 u_char *pkt; 1147 u_int pktlen; 1148{ 1149 struct bpf_d *d; 1150 u_int slen; 1151 1152 /* 1153 * Lockless read to avoid cost of locking the interface if there are 1154 * no descriptors attached. 1155 */ 1156 if (LIST_EMPTY(&bp->bif_dlist)) 1157 return; 1158 1159 BPFIF_LOCK(bp); 1160 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1161 BPFD_LOCK(d); 1162 ++d->bd_rcount; 1163 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1164 if (slen != 0) { 1165#ifdef MAC 1166 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1167#endif 1168 catchpacket(d, pkt, pktlen, slen, bcopy); 1169 } 1170 BPFD_UNLOCK(d); 1171 } 1172 BPFIF_UNLOCK(bp); 1173} 1174 1175/* 1176 * Copy data from an mbuf chain into a buffer. This code is derived 1177 * from m_copydata in sys/uipc_mbuf.c. 1178 */ 1179static void 1180bpf_mcopy(src_arg, dst_arg, len) 1181 const void *src_arg; 1182 void *dst_arg; 1183 size_t len; 1184{ 1185 const struct mbuf *m; 1186 u_int count; 1187 u_char *dst; 1188 1189 m = src_arg; 1190 dst = dst_arg; 1191 while (len > 0) { 1192 if (m == NULL) 1193 panic("bpf_mcopy"); 1194 count = min(m->m_len, len); 1195 bcopy(mtod(m, void *), dst, count); 1196 m = m->m_next; 1197 dst += count; 1198 len -= count; 1199 } 1200} 1201 1202/* 1203 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1204 */ 1205void 1206bpf_mtap(bp, m) 1207 struct bpf_if *bp; 1208 struct mbuf *m; 1209{ 1210 struct bpf_d *d; 1211 u_int pktlen, slen; 1212 1213 /* 1214 * Lockless read to avoid cost of locking the interface if there are 1215 * no descriptors attached. 1216 */ 1217 if (LIST_EMPTY(&bp->bif_dlist)) 1218 return; 1219 1220 pktlen = m_length(m, NULL); 1221 if (pktlen == m->m_len) { 1222 bpf_tap(bp, mtod(m, u_char *), pktlen); 1223 return; 1224 } 1225 1226 BPFIF_LOCK(bp); 1227 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1228 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1229 continue; 1230 BPFD_LOCK(d); 1231 ++d->bd_rcount; 1232 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1233 if (slen != 0) 1234#ifdef MAC 1235 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1236#endif 1237 catchpacket(d, (u_char *)m, pktlen, slen, 1238 bpf_mcopy); 1239 BPFD_UNLOCK(d); 1240 } 1241 BPFIF_UNLOCK(bp); 1242} 1243 1244/* 1245 * Incoming linkage from device drivers, when packet is in 1246 * an mbuf chain and to be prepended by a contiguous header. 1247 */ 1248void 1249bpf_mtap2(bp, data, dlen, m) 1250 struct bpf_if *bp; 1251 void *data; 1252 u_int dlen; 1253 struct mbuf *m; 1254{ 1255 struct mbuf mb; 1256 struct bpf_d *d; 1257 u_int pktlen, slen; 1258 1259 /* 1260 * Lockless read to avoid cost of locking the interface if there are 1261 * no descriptors attached. 1262 */ 1263 if (LIST_EMPTY(&bp->bif_dlist)) 1264 return; 1265 1266 pktlen = m_length(m, NULL); 1267 /* 1268 * Craft on-stack mbuf suitable for passing to bpf_filter. 1269 * Note that we cut corners here; we only setup what's 1270 * absolutely needed--this mbuf should never go anywhere else. 1271 */ 1272 mb.m_next = m; 1273 mb.m_data = data; 1274 mb.m_len = dlen; 1275 pktlen += dlen; 1276 1277 BPFIF_LOCK(bp); 1278 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1279 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1280 continue; 1281 BPFD_LOCK(d); 1282 ++d->bd_rcount; 1283 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0); 1284 if (slen != 0) 1285#ifdef MAC 1286 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1287#endif 1288 catchpacket(d, (u_char *)&mb, pktlen, slen, 1289 bpf_mcopy); 1290 BPFD_UNLOCK(d); 1291 } 1292 BPFIF_UNLOCK(bp); 1293} 1294 1295/* 1296 * Move the packet data from interface memory (pkt) into the 1297 * store buffer. "cpfn" is the routine called to do the actual data 1298 * transfer. bcopy is passed in to copy contiguous chunks, while 1299 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1300 * pkt is really an mbuf. 1301 */ 1302static void 1303catchpacket(d, pkt, pktlen, snaplen, cpfn) 1304 struct bpf_d *d; 1305 u_char *pkt; 1306 u_int pktlen, snaplen; 1307 void (*cpfn)(const void *, void *, size_t); 1308{ 1309 struct bpf_hdr *hp; 1310 int totlen, curlen; 1311 int hdrlen = d->bd_bif->bif_hdrlen; 1312 1313 /* 1314 * Figure out how many bytes to move. If the packet is 1315 * greater or equal to the snapshot length, transfer that 1316 * much. Otherwise, transfer the whole packet (unless 1317 * we hit the buffer size limit). 1318 */ 1319 totlen = hdrlen + min(snaplen, pktlen); 1320 if (totlen > d->bd_bufsize) 1321 totlen = d->bd_bufsize; 1322 1323 /* 1324 * Round up the end of the previous packet to the next longword. 1325 */ 1326 curlen = BPF_WORDALIGN(d->bd_slen); 1327 if (curlen + totlen > d->bd_bufsize) { 1328 /* 1329 * This packet will overflow the storage buffer. 1330 * Rotate the buffers if we can, then wakeup any 1331 * pending reads. 1332 */ 1333 if (d->bd_fbuf == NULL) { 1334 /* 1335 * We haven't completed the previous read yet, 1336 * so drop the packet. 1337 */ 1338 ++d->bd_dcount; 1339 return; 1340 } 1341 ROTATE_BUFFERS(d); 1342 bpf_wakeup(d); 1343 curlen = 0; 1344 } 1345 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1346 /* 1347 * Immediate mode is set, or the read timeout has 1348 * already expired during a select call. A packet 1349 * arrived, so the reader should be woken up. 1350 */ 1351 bpf_wakeup(d); 1352 1353 /* 1354 * Append the bpf header. 1355 */ 1356 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1357 microtime(&hp->bh_tstamp); 1358 hp->bh_datalen = pktlen; 1359 hp->bh_hdrlen = hdrlen; 1360 /* 1361 * Copy the packet data into the store buffer and update its length. 1362 */ 1363 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1364 d->bd_slen = curlen + totlen; 1365} 1366 1367/* 1368 * Initialize all nonzero fields of a descriptor. 1369 */ 1370static int 1371bpf_allocbufs(d) 1372 struct bpf_d *d; 1373{ 1374 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1375 if (d->bd_fbuf == NULL) 1376 return (ENOBUFS); 1377 1378 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1379 if (d->bd_sbuf == NULL) { 1380 free(d->bd_fbuf, M_BPF); 1381 return (ENOBUFS); 1382 } 1383 d->bd_slen = 0; 1384 d->bd_hlen = 0; 1385 return (0); 1386} 1387 1388/* 1389 * Free buffers currently in use by a descriptor. 1390 * Called on close. 1391 */ 1392static void 1393bpf_freed(d) 1394 struct bpf_d *d; 1395{ 1396 /* 1397 * We don't need to lock out interrupts since this descriptor has 1398 * been detached from its interface and it yet hasn't been marked 1399 * free. 1400 */ 1401 if (d->bd_sbuf != NULL) { 1402 free(d->bd_sbuf, M_BPF); 1403 if (d->bd_hbuf != NULL) 1404 free(d->bd_hbuf, M_BPF); 1405 if (d->bd_fbuf != NULL) 1406 free(d->bd_fbuf, M_BPF); 1407 } 1408 if (d->bd_filter) 1409 free((caddr_t)d->bd_filter, M_BPF); 1410 mtx_destroy(&d->bd_mtx); 1411} 1412 1413/* 1414 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1415 * fixed size of the link header (variable length headers not yet supported). 1416 */ 1417void 1418bpfattach(ifp, dlt, hdrlen) 1419 struct ifnet *ifp; 1420 u_int dlt, hdrlen; 1421{ 1422 1423 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1424} 1425 1426/* 1427 * Attach an interface to bpf. ifp is a pointer to the structure 1428 * defining the interface to be attached, dlt is the link layer type, 1429 * and hdrlen is the fixed size of the link header (variable length 1430 * headers are not yet supporrted). 1431 */ 1432void 1433bpfattach2(ifp, dlt, hdrlen, driverp) 1434 struct ifnet *ifp; 1435 u_int dlt, hdrlen; 1436 struct bpf_if **driverp; 1437{ 1438 struct bpf_if *bp; 1439 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1440 if (bp == NULL) 1441 panic("bpfattach"); 1442 1443 LIST_INIT(&bp->bif_dlist); 1444 bp->bif_driverp = driverp; 1445 bp->bif_ifp = ifp; 1446 bp->bif_dlt = dlt; 1447 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1448 1449 mtx_lock(&bpf_mtx); 1450 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1451 mtx_unlock(&bpf_mtx); 1452 1453 *bp->bif_driverp = NULL; 1454 1455 /* 1456 * Compute the length of the bpf header. This is not necessarily 1457 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1458 * that the network layer header begins on a longword boundary (for 1459 * performance reasons and to alleviate alignment restrictions). 1460 */ 1461 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1462 1463 if (bootverbose) 1464 if_printf(ifp, "bpf attached\n"); 1465} 1466 1467/* 1468 * Detach bpf from an interface. This involves detaching each descriptor 1469 * associated with the interface, and leaving bd_bif NULL. Notify each 1470 * descriptor as it's detached so that any sleepers wake up and get 1471 * ENXIO. 1472 */ 1473void 1474bpfdetach(ifp) 1475 struct ifnet *ifp; 1476{ 1477 struct bpf_if *bp; 1478 struct bpf_d *d; 1479 1480 /* Locate BPF interface information */ 1481 mtx_lock(&bpf_mtx); 1482 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1483 if (ifp == bp->bif_ifp) 1484 break; 1485 } 1486 1487 /* Interface wasn't attached */ 1488 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1489 mtx_unlock(&bpf_mtx); 1490 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1491 return; 1492 } 1493 1494 LIST_REMOVE(bp, bif_next); 1495 mtx_unlock(&bpf_mtx); 1496 1497 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1498 bpf_detachd(d); 1499 BPFD_LOCK(d); 1500 bpf_wakeup(d); 1501 BPFD_UNLOCK(d); 1502 } 1503 1504 mtx_destroy(&bp->bif_mtx); 1505 free(bp, M_BPF); 1506} 1507 1508/* 1509 * Get a list of available data link type of the interface. 1510 */ 1511static int 1512bpf_getdltlist(d, bfl) 1513 struct bpf_d *d; 1514 struct bpf_dltlist *bfl; 1515{ 1516 int n, error; 1517 struct ifnet *ifp; 1518 struct bpf_if *bp; 1519 1520 ifp = d->bd_bif->bif_ifp; 1521 n = 0; 1522 error = 0; 1523 mtx_lock(&bpf_mtx); 1524 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1525 if (bp->bif_ifp != ifp) 1526 continue; 1527 if (bfl->bfl_list != NULL) { 1528 if (n >= bfl->bfl_len) { 1529 mtx_unlock(&bpf_mtx); 1530 return (ENOMEM); 1531 } 1532 error = copyout(&bp->bif_dlt, 1533 bfl->bfl_list + n, sizeof(u_int)); 1534 } 1535 n++; 1536 } 1537 mtx_unlock(&bpf_mtx); 1538 bfl->bfl_len = n; 1539 return (error); 1540} 1541 1542/* 1543 * Set the data link type of a BPF instance. 1544 */ 1545static int 1546bpf_setdlt(d, dlt) 1547 struct bpf_d *d; 1548 u_int dlt; 1549{ 1550 int error, opromisc; 1551 struct ifnet *ifp; 1552 struct bpf_if *bp; 1553 1554 if (d->bd_bif->bif_dlt == dlt) 1555 return (0); 1556 ifp = d->bd_bif->bif_ifp; 1557 mtx_lock(&bpf_mtx); 1558 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1559 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1560 break; 1561 } 1562 mtx_unlock(&bpf_mtx); 1563 if (bp != NULL) { 1564 opromisc = d->bd_promisc; 1565 bpf_detachd(d); 1566 bpf_attachd(d, bp); 1567 BPFD_LOCK(d); 1568 reset_d(d); 1569 BPFD_UNLOCK(d); 1570 if (opromisc) { 1571 error = ifpromisc(bp->bif_ifp, 1); 1572 if (error) 1573 if_printf(bp->bif_ifp, 1574 "bpf_setdlt: ifpromisc failed (%d)\n", 1575 error); 1576 else 1577 d->bd_promisc = 1; 1578 } 1579 } 1580 return (bp == NULL ? EINVAL : 0); 1581} 1582 1583static void bpf_drvinit(void *unused); 1584 1585static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev); 1586 1587static void 1588bpf_clone(arg, name, namelen, dev) 1589 void *arg; 1590 char *name; 1591 int namelen; 1592 struct cdev **dev; 1593{ 1594 int u; 1595 1596 if (*dev != NULL) 1597 return; 1598 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1599 return; 1600 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1601 "bpf%d", u); 1602 (*dev)->si_flags |= SI_CHEAPCLONE; 1603 return; 1604} 1605 1606static void 1607bpf_drvinit(unused) 1608 void *unused; 1609{ 1610 1611 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1612 LIST_INIT(&bpf_iflist); 1613 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1614} 1615 1616SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1617 1618#else /* !DEV_BPF && !NETGRAPH_BPF */ 1619/* 1620 * NOP stubs to allow bpf-using drivers to load and function. 1621 * 1622 * A 'better' implementation would allow the core bpf functionality 1623 * to be loaded at runtime. 1624 */ 1625 1626void 1627bpf_tap(bp, pkt, pktlen) 1628 struct bpf_if *bp; 1629 u_char *pkt; 1630 u_int pktlen; 1631{ 1632} 1633 1634void 1635bpf_mtap(bp, m) 1636 struct bpf_if *bp; 1637 struct mbuf *m; 1638{ 1639} 1640 1641void 1642bpf_mtap2(bp, d, l, m) 1643 struct bpf_if *bp; 1644 void *d; 1645 u_int l; 1646 struct mbuf *m; 1647{ 1648} 1649 1650void 1651bpfattach(ifp, dlt, hdrlen) 1652 struct ifnet *ifp; 1653 u_int dlt, hdrlen; 1654{ 1655} 1656 1657void 1658bpfattach2(ifp, dlt, hdrlen, driverp) 1659 struct ifnet *ifp; 1660 u_int dlt, hdrlen; 1661 struct bpf_if **driverp; 1662{ 1663} 1664 1665void 1666bpfdetach(ifp) 1667 struct ifnet *ifp; 1668{ 1669} 1670 1671u_int 1672bpf_filter(pc, p, wirelen, buflen) 1673 const struct bpf_insn *pc; 1674 u_char *p; 1675 u_int wirelen; 1676 u_int buflen; 1677{ 1678 return -1; /* "no filter" behaviour */ 1679} 1680 1681int 1682bpf_validate(f, len) 1683 const struct bpf_insn *f; 1684 int len; 1685{ 1686 return 0; /* false */ 1687} 1688 1689#endif /* !DEV_BPF && !NETGRAPH_BPF */ 1690