bpf.c revision 143064
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 143064 2005-03-02 21:59:39Z jmg $ 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, NET_CALLOUT_MPSAFE); 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 if (fp->bf_insns == NULL) { 951 if (fp->bf_len != 0) 952 return (EINVAL); 953 BPFD_LOCK(d); 954 old = d->bd_filter; 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 old = d->bd_filter; 972 d->bd_filter = fcode; 973 reset_d(d); 974 BPFD_UNLOCK(d); 975 if (old != NULL) 976 free((caddr_t)old, M_BPF); 977 978 return (0); 979 } 980 free((caddr_t)fcode, M_BPF); 981 return (EINVAL); 982} 983 984/* 985 * Detach a file from its current interface (if attached at all) and attach 986 * to the interface indicated by the name stored in ifr. 987 * Return an errno or 0. 988 */ 989static int 990bpf_setif(d, ifr) 991 struct bpf_d *d; 992 struct ifreq *ifr; 993{ 994 struct bpf_if *bp; 995 int error; 996 struct ifnet *theywant; 997 998 theywant = ifunit(ifr->ifr_name); 999 if (theywant == NULL) 1000 return ENXIO; 1001 1002 /* 1003 * Look through attached interfaces for the named one. 1004 */ 1005 mtx_lock(&bpf_mtx); 1006 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1007 struct ifnet *ifp = bp->bif_ifp; 1008 1009 if (ifp == NULL || ifp != theywant) 1010 continue; 1011 /* skip additional entry */ 1012 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 1013 continue; 1014 1015 mtx_unlock(&bpf_mtx); 1016 /* 1017 * We found the requested interface. 1018 * Allocate the packet buffers if we need to. 1019 * If we're already attached to requested interface, 1020 * just flush the buffer. 1021 */ 1022 if (d->bd_sbuf == NULL) { 1023 error = bpf_allocbufs(d); 1024 if (error != 0) 1025 return (error); 1026 } 1027 if (bp != d->bd_bif) { 1028 if (d->bd_bif) 1029 /* 1030 * Detach if attached to something else. 1031 */ 1032 bpf_detachd(d); 1033 1034 bpf_attachd(d, bp); 1035 } 1036 BPFD_LOCK(d); 1037 reset_d(d); 1038 BPFD_UNLOCK(d); 1039 return (0); 1040 } 1041 mtx_unlock(&bpf_mtx); 1042 /* Not found. */ 1043 return (ENXIO); 1044} 1045 1046/* 1047 * Support for select() and poll() system calls 1048 * 1049 * Return true iff the specific operation will not block indefinitely. 1050 * Otherwise, return false but make a note that a selwakeup() must be done. 1051 */ 1052static int 1053bpfpoll(dev, events, td) 1054 struct cdev *dev; 1055 int events; 1056 struct thread *td; 1057{ 1058 struct bpf_d *d; 1059 int revents; 1060 1061 d = dev->si_drv1; 1062 if (d->bd_bif == NULL) 1063 return (ENXIO); 1064 1065 revents = events & (POLLOUT | POLLWRNORM); 1066 BPFD_LOCK(d); 1067 if (events & (POLLIN | POLLRDNORM)) { 1068 if (bpf_ready(d)) 1069 revents |= events & (POLLIN | POLLRDNORM); 1070 else { 1071 selrecord(td, &d->bd_sel); 1072 /* Start the read timeout if necessary. */ 1073 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1074 callout_reset(&d->bd_callout, d->bd_rtout, 1075 bpf_timed_out, d); 1076 d->bd_state = BPF_WAITING; 1077 } 1078 } 1079 } 1080 BPFD_UNLOCK(d); 1081 return (revents); 1082} 1083 1084/* 1085 * Support for kevent() system call. Register EVFILT_READ filters and 1086 * reject all others. 1087 */ 1088int 1089bpfkqfilter(dev, kn) 1090 struct cdev *dev; 1091 struct knote *kn; 1092{ 1093 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1094 1095 if (kn->kn_filter != EVFILT_READ) 1096 return (1); 1097 1098 kn->kn_fop = &bpfread_filtops; 1099 kn->kn_hook = d; 1100 knlist_add(&d->bd_sel.si_note, kn, 0); 1101 1102 return (0); 1103} 1104 1105static void 1106filt_bpfdetach(kn) 1107 struct knote *kn; 1108{ 1109 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1110 1111 knlist_remove(&d->bd_sel.si_note, kn, 0); 1112} 1113 1114static int 1115filt_bpfread(kn, hint) 1116 struct knote *kn; 1117 long hint; 1118{ 1119 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1120 int ready; 1121 1122 BPFD_LOCK_ASSERT(d); 1123 ready = bpf_ready(d); 1124 if (ready) { 1125 kn->kn_data = d->bd_slen; 1126 if (d->bd_hbuf) 1127 kn->kn_data += d->bd_hlen; 1128 } 1129 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1130 callout_reset(&d->bd_callout, d->bd_rtout, 1131 bpf_timed_out, d); 1132 d->bd_state = BPF_WAITING; 1133 } 1134 1135 return (ready); 1136} 1137 1138/* 1139 * Incoming linkage from device drivers. Process the packet pkt, of length 1140 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1141 * by each process' filter, and if accepted, stashed into the corresponding 1142 * buffer. 1143 */ 1144void 1145bpf_tap(bp, pkt, pktlen) 1146 struct bpf_if *bp; 1147 u_char *pkt; 1148 u_int pktlen; 1149{ 1150 struct bpf_d *d; 1151 u_int slen; 1152 1153 /* 1154 * Lockless read to avoid cost of locking the interface if there are 1155 * no descriptors attached. 1156 */ 1157 if (LIST_EMPTY(&bp->bif_dlist)) 1158 return; 1159 1160 BPFIF_LOCK(bp); 1161 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1162 BPFD_LOCK(d); 1163 ++d->bd_rcount; 1164 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1165 if (slen != 0) { 1166#ifdef MAC 1167 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1168#endif 1169 catchpacket(d, pkt, pktlen, slen, bcopy); 1170 } 1171 BPFD_UNLOCK(d); 1172 } 1173 BPFIF_UNLOCK(bp); 1174} 1175 1176/* 1177 * Copy data from an mbuf chain into a buffer. This code is derived 1178 * from m_copydata in sys/uipc_mbuf.c. 1179 */ 1180static void 1181bpf_mcopy(src_arg, dst_arg, len) 1182 const void *src_arg; 1183 void *dst_arg; 1184 size_t len; 1185{ 1186 const struct mbuf *m; 1187 u_int count; 1188 u_char *dst; 1189 1190 m = src_arg; 1191 dst = dst_arg; 1192 while (len > 0) { 1193 if (m == NULL) 1194 panic("bpf_mcopy"); 1195 count = min(m->m_len, len); 1196 bcopy(mtod(m, void *), dst, count); 1197 m = m->m_next; 1198 dst += count; 1199 len -= count; 1200 } 1201} 1202 1203/* 1204 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1205 */ 1206void 1207bpf_mtap(bp, m) 1208 struct bpf_if *bp; 1209 struct mbuf *m; 1210{ 1211 struct bpf_d *d; 1212 u_int pktlen, slen; 1213 1214 /* 1215 * Lockless read to avoid cost of locking the interface if there are 1216 * no descriptors attached. 1217 */ 1218 if (LIST_EMPTY(&bp->bif_dlist)) 1219 return; 1220 1221 pktlen = m_length(m, NULL); 1222 if (pktlen == m->m_len) { 1223 bpf_tap(bp, mtod(m, u_char *), pktlen); 1224 return; 1225 } 1226 1227 BPFIF_LOCK(bp); 1228 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1229 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1230 continue; 1231 BPFD_LOCK(d); 1232 ++d->bd_rcount; 1233 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1234 if (slen != 0) 1235#ifdef MAC 1236 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1237#endif 1238 catchpacket(d, (u_char *)m, pktlen, slen, 1239 bpf_mcopy); 1240 BPFD_UNLOCK(d); 1241 } 1242 BPFIF_UNLOCK(bp); 1243} 1244 1245/* 1246 * Incoming linkage from device drivers, when packet is in 1247 * an mbuf chain and to be prepended by a contiguous header. 1248 */ 1249void 1250bpf_mtap2(bp, data, dlen, m) 1251 struct bpf_if *bp; 1252 void *data; 1253 u_int dlen; 1254 struct mbuf *m; 1255{ 1256 struct mbuf mb; 1257 struct bpf_d *d; 1258 u_int pktlen, slen; 1259 1260 /* 1261 * Lockless read to avoid cost of locking the interface if there are 1262 * no descriptors attached. 1263 */ 1264 if (LIST_EMPTY(&bp->bif_dlist)) 1265 return; 1266 1267 pktlen = m_length(m, NULL); 1268 /* 1269 * Craft on-stack mbuf suitable for passing to bpf_filter. 1270 * Note that we cut corners here; we only setup what's 1271 * absolutely needed--this mbuf should never go anywhere else. 1272 */ 1273 mb.m_next = m; 1274 mb.m_data = data; 1275 mb.m_len = dlen; 1276 pktlen += dlen; 1277 1278 BPFIF_LOCK(bp); 1279 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1280 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1281 continue; 1282 BPFD_LOCK(d); 1283 ++d->bd_rcount; 1284 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0); 1285 if (slen != 0) 1286#ifdef MAC 1287 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1288#endif 1289 catchpacket(d, (u_char *)&mb, pktlen, slen, 1290 bpf_mcopy); 1291 BPFD_UNLOCK(d); 1292 } 1293 BPFIF_UNLOCK(bp); 1294} 1295 1296/* 1297 * Move the packet data from interface memory (pkt) into the 1298 * store buffer. "cpfn" is the routine called to do the actual data 1299 * transfer. bcopy is passed in to copy contiguous chunks, while 1300 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1301 * pkt is really an mbuf. 1302 */ 1303static void 1304catchpacket(d, pkt, pktlen, snaplen, cpfn) 1305 struct bpf_d *d; 1306 u_char *pkt; 1307 u_int pktlen, snaplen; 1308 void (*cpfn)(const void *, void *, size_t); 1309{ 1310 struct bpf_hdr *hp; 1311 int totlen, curlen; 1312 int hdrlen = d->bd_bif->bif_hdrlen; 1313 int do_wakeup = 0; 1314 1315 /* 1316 * Figure out how many bytes to move. If the packet is 1317 * greater or equal to the snapshot length, transfer that 1318 * much. Otherwise, transfer the whole packet (unless 1319 * we hit the buffer size limit). 1320 */ 1321 totlen = hdrlen + min(snaplen, pktlen); 1322 if (totlen > d->bd_bufsize) 1323 totlen = d->bd_bufsize; 1324 1325 /* 1326 * Round up the end of the previous packet to the next longword. 1327 */ 1328 curlen = BPF_WORDALIGN(d->bd_slen); 1329 if (curlen + totlen > d->bd_bufsize) { 1330 /* 1331 * This packet will overflow the storage buffer. 1332 * Rotate the buffers if we can, then wakeup any 1333 * pending reads. 1334 */ 1335 if (d->bd_fbuf == NULL) { 1336 /* 1337 * We haven't completed the previous read yet, 1338 * so drop the packet. 1339 */ 1340 ++d->bd_dcount; 1341 return; 1342 } 1343 ROTATE_BUFFERS(d); 1344 do_wakeup = 1; 1345 curlen = 0; 1346 } 1347 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1348 /* 1349 * Immediate mode is set, or the read timeout has 1350 * already expired during a select call. A packet 1351 * arrived, so the reader should be woken up. 1352 */ 1353 do_wakeup = 1; 1354 1355 /* 1356 * Append the bpf header. 1357 */ 1358 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1359 microtime(&hp->bh_tstamp); 1360 hp->bh_datalen = pktlen; 1361 hp->bh_hdrlen = hdrlen; 1362 /* 1363 * Copy the packet data into the store buffer and update its length. 1364 */ 1365 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1366 d->bd_slen = curlen + totlen; 1367 1368 if (do_wakeup) 1369 bpf_wakeup(d); 1370} 1371 1372/* 1373 * Initialize all nonzero fields of a descriptor. 1374 */ 1375static int 1376bpf_allocbufs(d) 1377 struct bpf_d *d; 1378{ 1379 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1380 if (d->bd_fbuf == NULL) 1381 return (ENOBUFS); 1382 1383 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1384 if (d->bd_sbuf == NULL) { 1385 free(d->bd_fbuf, M_BPF); 1386 return (ENOBUFS); 1387 } 1388 d->bd_slen = 0; 1389 d->bd_hlen = 0; 1390 return (0); 1391} 1392 1393/* 1394 * Free buffers currently in use by a descriptor. 1395 * Called on close. 1396 */ 1397static void 1398bpf_freed(d) 1399 struct bpf_d *d; 1400{ 1401 /* 1402 * We don't need to lock out interrupts since this descriptor has 1403 * been detached from its interface and it yet hasn't been marked 1404 * free. 1405 */ 1406 if (d->bd_sbuf != NULL) { 1407 free(d->bd_sbuf, M_BPF); 1408 if (d->bd_hbuf != NULL) 1409 free(d->bd_hbuf, M_BPF); 1410 if (d->bd_fbuf != NULL) 1411 free(d->bd_fbuf, M_BPF); 1412 } 1413 if (d->bd_filter) 1414 free((caddr_t)d->bd_filter, M_BPF); 1415 mtx_destroy(&d->bd_mtx); 1416} 1417 1418/* 1419 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1420 * fixed size of the link header (variable length headers not yet supported). 1421 */ 1422void 1423bpfattach(ifp, dlt, hdrlen) 1424 struct ifnet *ifp; 1425 u_int dlt, hdrlen; 1426{ 1427 1428 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1429} 1430 1431/* 1432 * Attach an interface to bpf. ifp is a pointer to the structure 1433 * defining the interface to be attached, dlt is the link layer type, 1434 * and hdrlen is the fixed size of the link header (variable length 1435 * headers are not yet supporrted). 1436 */ 1437void 1438bpfattach2(ifp, dlt, hdrlen, driverp) 1439 struct ifnet *ifp; 1440 u_int dlt, hdrlen; 1441 struct bpf_if **driverp; 1442{ 1443 struct bpf_if *bp; 1444 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1445 if (bp == NULL) 1446 panic("bpfattach"); 1447 1448 LIST_INIT(&bp->bif_dlist); 1449 bp->bif_driverp = driverp; 1450 bp->bif_ifp = ifp; 1451 bp->bif_dlt = dlt; 1452 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1453 1454 mtx_lock(&bpf_mtx); 1455 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1456 mtx_unlock(&bpf_mtx); 1457 1458 *bp->bif_driverp = NULL; 1459 1460 /* 1461 * Compute the length of the bpf header. This is not necessarily 1462 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1463 * that the network layer header begins on a longword boundary (for 1464 * performance reasons and to alleviate alignment restrictions). 1465 */ 1466 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1467 1468 if (bootverbose) 1469 if_printf(ifp, "bpf attached\n"); 1470} 1471 1472/* 1473 * Detach bpf from an interface. This involves detaching each descriptor 1474 * associated with the interface, and leaving bd_bif NULL. Notify each 1475 * descriptor as it's detached so that any sleepers wake up and get 1476 * ENXIO. 1477 */ 1478void 1479bpfdetach(ifp) 1480 struct ifnet *ifp; 1481{ 1482 struct bpf_if *bp; 1483 struct bpf_d *d; 1484 1485 /* Locate BPF interface information */ 1486 mtx_lock(&bpf_mtx); 1487 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1488 if (ifp == bp->bif_ifp) 1489 break; 1490 } 1491 1492 /* Interface wasn't attached */ 1493 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1494 mtx_unlock(&bpf_mtx); 1495 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1496 return; 1497 } 1498 1499 LIST_REMOVE(bp, bif_next); 1500 mtx_unlock(&bpf_mtx); 1501 1502 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1503 bpf_detachd(d); 1504 BPFD_LOCK(d); 1505 bpf_wakeup(d); 1506 BPFD_UNLOCK(d); 1507 } 1508 1509 mtx_destroy(&bp->bif_mtx); 1510 free(bp, M_BPF); 1511} 1512 1513/* 1514 * Get a list of available data link type of the interface. 1515 */ 1516static int 1517bpf_getdltlist(d, bfl) 1518 struct bpf_d *d; 1519 struct bpf_dltlist *bfl; 1520{ 1521 int n, error; 1522 struct ifnet *ifp; 1523 struct bpf_if *bp; 1524 1525 ifp = d->bd_bif->bif_ifp; 1526 n = 0; 1527 error = 0; 1528 mtx_lock(&bpf_mtx); 1529 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1530 if (bp->bif_ifp != ifp) 1531 continue; 1532 if (bfl->bfl_list != NULL) { 1533 if (n >= bfl->bfl_len) { 1534 mtx_unlock(&bpf_mtx); 1535 return (ENOMEM); 1536 } 1537 error = copyout(&bp->bif_dlt, 1538 bfl->bfl_list + n, sizeof(u_int)); 1539 } 1540 n++; 1541 } 1542 mtx_unlock(&bpf_mtx); 1543 bfl->bfl_len = n; 1544 return (error); 1545} 1546 1547/* 1548 * Set the data link type of a BPF instance. 1549 */ 1550static int 1551bpf_setdlt(d, dlt) 1552 struct bpf_d *d; 1553 u_int dlt; 1554{ 1555 int error, opromisc; 1556 struct ifnet *ifp; 1557 struct bpf_if *bp; 1558 1559 if (d->bd_bif->bif_dlt == dlt) 1560 return (0); 1561 ifp = d->bd_bif->bif_ifp; 1562 mtx_lock(&bpf_mtx); 1563 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1564 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1565 break; 1566 } 1567 mtx_unlock(&bpf_mtx); 1568 if (bp != NULL) { 1569 opromisc = d->bd_promisc; 1570 bpf_detachd(d); 1571 bpf_attachd(d, bp); 1572 BPFD_LOCK(d); 1573 reset_d(d); 1574 BPFD_UNLOCK(d); 1575 if (opromisc) { 1576 error = ifpromisc(bp->bif_ifp, 1); 1577 if (error) 1578 if_printf(bp->bif_ifp, 1579 "bpf_setdlt: ifpromisc failed (%d)\n", 1580 error); 1581 else 1582 d->bd_promisc = 1; 1583 } 1584 } 1585 return (bp == NULL ? EINVAL : 0); 1586} 1587 1588static void bpf_drvinit(void *unused); 1589 1590static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev); 1591 1592static void 1593bpf_clone(arg, name, namelen, dev) 1594 void *arg; 1595 char *name; 1596 int namelen; 1597 struct cdev **dev; 1598{ 1599 int u; 1600 1601 if (*dev != NULL) 1602 return; 1603 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1604 return; 1605 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1606 "bpf%d", u); 1607 (*dev)->si_flags |= SI_CHEAPCLONE; 1608 return; 1609} 1610 1611static void 1612bpf_drvinit(unused) 1613 void *unused; 1614{ 1615 1616 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1617 LIST_INIT(&bpf_iflist); 1618 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1619} 1620 1621SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1622 1623#else /* !DEV_BPF && !NETGRAPH_BPF */ 1624/* 1625 * NOP stubs to allow bpf-using drivers to load and function. 1626 * 1627 * A 'better' implementation would allow the core bpf functionality 1628 * to be loaded at runtime. 1629 */ 1630 1631void 1632bpf_tap(bp, pkt, pktlen) 1633 struct bpf_if *bp; 1634 u_char *pkt; 1635 u_int pktlen; 1636{ 1637} 1638 1639void 1640bpf_mtap(bp, m) 1641 struct bpf_if *bp; 1642 struct mbuf *m; 1643{ 1644} 1645 1646void 1647bpf_mtap2(bp, d, l, m) 1648 struct bpf_if *bp; 1649 void *d; 1650 u_int l; 1651 struct mbuf *m; 1652{ 1653} 1654 1655void 1656bpfattach(ifp, dlt, hdrlen) 1657 struct ifnet *ifp; 1658 u_int dlt, hdrlen; 1659{ 1660} 1661 1662void 1663bpfattach2(ifp, dlt, hdrlen, driverp) 1664 struct ifnet *ifp; 1665 u_int dlt, hdrlen; 1666 struct bpf_if **driverp; 1667{ 1668} 1669 1670void 1671bpfdetach(ifp) 1672 struct ifnet *ifp; 1673{ 1674} 1675 1676u_int 1677bpf_filter(pc, p, wirelen, buflen) 1678 const struct bpf_insn *pc; 1679 u_char *p; 1680 u_int wirelen; 1681 u_int buflen; 1682{ 1683 return -1; /* "no filter" behaviour */ 1684} 1685 1686int 1687bpf_validate(f, len) 1688 const struct bpf_insn *f; 1689 int len; 1690{ 1691 return 0; /* false */ 1692} 1693 1694#endif /* !DEV_BPF && !NETGRAPH_BPF */ 1695