Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/net/bpf.c
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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: releng/5.3/sys/net/bpf.c 136588 2004-10-16 08:43:07Z cvs2svn $ 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/mac.h> 48 #include <sys/malloc.h> 49 #include <sys/mbuf.h> 50 #include <sys/time.h> 51 #include <sys/proc.h> 52 #include <sys/signalvar.h> 53 #include <sys/filio.h> 54 #include <sys/sockio.h> 55 #include <sys/ttycom.h> 56 #include <sys/filedesc.h> 57 58 #include <sys/event.h> 59 #include <sys/file.h> 60 #include <sys/poll.h> 61 #include <sys/proc.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 LIST_HEAD(, 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 static void filt_bpfdetach(struct knote *); 115 static int filt_bpfread(struct knote *, long); 116 117 static d_open_t bpfopen; 118 static d_close_t bpfclose; 119 static d_read_t bpfread; 120 static d_write_t bpfwrite; 121 static d_ioctl_t bpfioctl; 122 static d_poll_t bpfpoll; 123 static d_kqfilter_t bpfkqfilter; 124 125 static struct cdevsw bpf_cdevsw = { 126 .d_version = D_VERSION, 127 .d_flags = D_NEEDGIANT, 128 .d_open = bpfopen, 129 .d_close = bpfclose, 130 .d_read = bpfread, 131 .d_write = bpfwrite, 132 .d_ioctl = bpfioctl, 133 .d_poll = bpfpoll, 134 .d_name = "bpf", 135 .d_kqfilter = bpfkqfilter, 136 }; 137 138 static struct filterops bpfread_filtops = 139 { 1, NULL, filt_bpfdetach, filt_bpfread }; 140 141 static int 142 bpf_movein(uio, linktype, mp, sockp, datlen) 143 struct uio *uio; 144 int linktype, *datlen; 145 struct mbuf **mp; 146 struct sockaddr *sockp; 147 { 148 struct mbuf *m; 149 int error; 150 int len; 151 int hlen; 152 153 /* 154 * Build a sockaddr based on the data link layer type. 155 * We do this at this level because the ethernet header 156 * is copied directly into the data field of the sockaddr. 157 * In the case of SLIP, there is no header and the packet 158 * is forwarded as is. 159 * Also, we are careful to leave room at the front of the mbuf 160 * for the link level header. 161 */ 162 switch (linktype) { 163 164 case DLT_SLIP: 165 sockp->sa_family = AF_INET; 166 hlen = 0; 167 break; 168 169 case DLT_EN10MB: 170 sockp->sa_family = AF_UNSPEC; 171 /* XXX Would MAXLINKHDR be better? */ 172 hlen = ETHER_HDR_LEN; 173 break; 174 175 case DLT_FDDI: 176 sockp->sa_family = AF_IMPLINK; 177 hlen = 0; 178 break; 179 180 case DLT_RAW: 181 case DLT_NULL: 182 sockp->sa_family = AF_UNSPEC; 183 hlen = 0; 184 break; 185 186 case DLT_ATM_RFC1483: 187 /* 188 * en atm driver requires 4-byte atm pseudo header. 189 * though it isn't standard, vpi:vci needs to be 190 * specified anyway. 191 */ 192 sockp->sa_family = AF_UNSPEC; 193 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 194 break; 195 196 case DLT_PPP: 197 sockp->sa_family = AF_UNSPEC; 198 hlen = 4; /* This should match PPP_HDRLEN */ 199 break; 200 201 default: 202 return (EIO); 203 } 204 205 len = uio->uio_resid; 206 *datlen = len - hlen; 207 if ((unsigned)len > MCLBYTES) 208 return (EIO); 209 210 if (len > MHLEN) { 211 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 212 } else { 213 MGETHDR(m, M_TRYWAIT, MT_DATA); 214 } 215 if (m == NULL) 216 return (ENOBUFS); 217 m->m_pkthdr.len = m->m_len = len; 218 m->m_pkthdr.rcvif = NULL; 219 *mp = m; 220 221 /* 222 * Make room for link header. 223 */ 224 if (hlen != 0) { 225 m->m_pkthdr.len -= hlen; 226 m->m_len -= hlen; 227 #if BSD >= 199103 228 m->m_data += hlen; /* XXX */ 229 #else 230 m->m_off += hlen; 231 #endif 232 error = uiomove(sockp->sa_data, hlen, uio); 233 if (error) 234 goto bad; 235 } 236 error = uiomove(mtod(m, void *), len - hlen, uio); 237 if (!error) 238 return (0); 239 bad: 240 m_freem(m); 241 return (error); 242 } 243 244 /* 245 * Attach file to the bpf interface, i.e. make d listen on bp. 246 */ 247 static void 248 bpf_attachd(d, bp) 249 struct bpf_d *d; 250 struct bpf_if *bp; 251 { 252 /* 253 * Point d at bp, and add d to the interface's list of listeners. 254 * Finally, point the driver's bpf cookie at the interface so 255 * it will divert packets to bpf. 256 */ 257 BPFIF_LOCK(bp); 258 d->bd_bif = bp; 259 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 260 261 *bp->bif_driverp = bp; 262 BPFIF_UNLOCK(bp); 263 } 264 265 /* 266 * Detach a file from its interface. 267 */ 268 static void 269 bpf_detachd(d) 270 struct bpf_d *d; 271 { 272 int error; 273 struct bpf_if *bp; 274 struct ifnet *ifp; 275 276 bp = d->bd_bif; 277 BPFIF_LOCK(bp); 278 BPFD_LOCK(d); 279 ifp = d->bd_bif->bif_ifp; 280 281 /* 282 * Remove d from the interface's descriptor list. 283 */ 284 LIST_REMOVE(d, bd_next); 285 286 /* 287 * Let the driver know that there are no more listeners. 288 */ 289 if (LIST_EMPTY(&bp->bif_dlist)) 290 *bp->bif_driverp = NULL; 291 292 d->bd_bif = NULL; 293 BPFD_UNLOCK(d); 294 BPFIF_UNLOCK(bp); 295 296 /* 297 * Check if this descriptor had requested promiscuous mode. 298 * If so, turn it off. 299 */ 300 if (d->bd_promisc) { 301 d->bd_promisc = 0; 302 error = ifpromisc(ifp, 0); 303 if (error != 0 && error != ENXIO) { 304 /* 305 * ENXIO can happen if a pccard is unplugged 306 * Something is really wrong if we were able to put 307 * the driver into promiscuous mode, but can't 308 * take it out. 309 */ 310 if_printf(bp->bif_ifp, 311 "bpf_detach: ifpromisc failed (%d)\n", error); 312 } 313 } 314 } 315 316 /* 317 * Open ethernet device. Returns ENXIO for illegal minor device number, 318 * EBUSY if file is open by another process. 319 */ 320 /* ARGSUSED */ 321 static int 322 bpfopen(dev, flags, fmt, td) 323 struct cdev *dev; 324 int flags; 325 int fmt; 326 struct thread *td; 327 { 328 struct bpf_d *d; 329 330 mtx_lock(&bpf_mtx); 331 d = dev->si_drv1; 332 /* 333 * Each minor can be opened by only one process. If the requested 334 * minor is in use, return EBUSY. 335 */ 336 if (d != NULL) { 337 mtx_unlock(&bpf_mtx); 338 return (EBUSY); 339 } 340 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 341 mtx_unlock(&bpf_mtx); 342 343 if ((dev->si_flags & SI_NAMED) == 0) 344 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 345 "bpf%d", dev2unit(dev)); 346 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 347 dev->si_drv1 = d; 348 d->bd_bufsize = bpf_bufsize; 349 d->bd_sig = SIGIO; 350 d->bd_seesent = 1; 351 #ifdef MAC 352 mac_init_bpfdesc(d); 353 mac_create_bpfdesc(td->td_ucred, d); 354 #endif 355 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 356 callout_init(&d->bd_callout, debug_mpsafenet ? CALLOUT_MPSAFE : 0); 357 knlist_init(&d->bd_sel.si_note, &d->bd_mtx); 358 359 return (0); 360 } 361 362 /* 363 * Close the descriptor by detaching it from its interface, 364 * deallocating its buffers, and marking it free. 365 */ 366 /* ARGSUSED */ 367 static int 368 bpfclose(dev, flags, fmt, td) 369 struct cdev *dev; 370 int flags; 371 int fmt; 372 struct thread *td; 373 { 374 struct bpf_d *d = dev->si_drv1; 375 376 BPFD_LOCK(d); 377 if (d->bd_state == BPF_WAITING) 378 callout_stop(&d->bd_callout); 379 d->bd_state = BPF_IDLE; 380 BPFD_UNLOCK(d); 381 funsetown(&d->bd_sigio); 382 mtx_lock(&bpf_mtx); 383 if (d->bd_bif) 384 bpf_detachd(d); 385 mtx_unlock(&bpf_mtx); 386 #ifdef MAC 387 mac_destroy_bpfdesc(d); 388 #endif /* MAC */ 389 knlist_destroy(&d->bd_sel.si_note); 390 bpf_freed(d); 391 dev->si_drv1 = NULL; 392 free(d, M_BPF); 393 394 return (0); 395 } 396 397 398 /* 399 * Rotate the packet buffers in descriptor d. Move the store buffer 400 * into the hold slot, and the free buffer into the store slot. 401 * Zero the length of the new store buffer. 402 */ 403 #define ROTATE_BUFFERS(d) \ 404 (d)->bd_hbuf = (d)->bd_sbuf; \ 405 (d)->bd_hlen = (d)->bd_slen; \ 406 (d)->bd_sbuf = (d)->bd_fbuf; \ 407 (d)->bd_slen = 0; \ 408 (d)->bd_fbuf = NULL; 409 /* 410 * bpfread - read next chunk of packets from buffers 411 */ 412 static int 413 bpfread(dev, uio, ioflag) 414 struct cdev *dev; 415 struct uio *uio; 416 int ioflag; 417 { 418 struct bpf_d *d = dev->si_drv1; 419 int timed_out; 420 int error; 421 422 /* 423 * Restrict application to use a buffer the same size as 424 * as kernel buffers. 425 */ 426 if (uio->uio_resid != d->bd_bufsize) 427 return (EINVAL); 428 429 BPFD_LOCK(d); 430 if (d->bd_state == BPF_WAITING) 431 callout_stop(&d->bd_callout); 432 timed_out = (d->bd_state == BPF_TIMED_OUT); 433 d->bd_state = BPF_IDLE; 434 /* 435 * If the hold buffer is empty, then do a timed sleep, which 436 * ends when the timeout expires or when enough packets 437 * have arrived to fill the store buffer. 438 */ 439 while (d->bd_hbuf == NULL) { 440 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 441 /* 442 * A packet(s) either arrived since the previous 443 * read or arrived while we were asleep. 444 * Rotate the buffers and return what's here. 445 */ 446 ROTATE_BUFFERS(d); 447 break; 448 } 449 450 /* 451 * No data is available, check to see if the bpf device 452 * is still pointed at a real interface. If not, return 453 * ENXIO so that the userland process knows to rebind 454 * it before using it again. 455 */ 456 if (d->bd_bif == NULL) { 457 BPFD_UNLOCK(d); 458 return (ENXIO); 459 } 460 461 if (ioflag & IO_NDELAY) { 462 BPFD_UNLOCK(d); 463 return (EWOULDBLOCK); 464 } 465 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 466 "bpf", d->bd_rtout); 467 if (error == EINTR || error == ERESTART) { 468 BPFD_UNLOCK(d); 469 return (error); 470 } 471 if (error == EWOULDBLOCK) { 472 /* 473 * On a timeout, return what's in the buffer, 474 * which may be nothing. If there is something 475 * in the store buffer, we can rotate the buffers. 476 */ 477 if (d->bd_hbuf) 478 /* 479 * We filled up the buffer in between 480 * getting the timeout and arriving 481 * here, so we don't need to rotate. 482 */ 483 break; 484 485 if (d->bd_slen == 0) { 486 BPFD_UNLOCK(d); 487 return (0); 488 } 489 ROTATE_BUFFERS(d); 490 break; 491 } 492 } 493 /* 494 * At this point, we know we have something in the hold slot. 495 */ 496 BPFD_UNLOCK(d); 497 498 /* 499 * Move data from hold buffer into user space. 500 * We know the entire buffer is transferred since 501 * we checked above that the read buffer is bpf_bufsize bytes. 502 */ 503 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 504 505 BPFD_LOCK(d); 506 d->bd_fbuf = d->bd_hbuf; 507 d->bd_hbuf = NULL; 508 d->bd_hlen = 0; 509 BPFD_UNLOCK(d); 510 511 return (error); 512 } 513 514 515 /* 516 * If there are processes sleeping on this descriptor, wake them up. 517 */ 518 static __inline void 519 bpf_wakeup(d) 520 struct bpf_d *d; 521 { 522 if (d->bd_state == BPF_WAITING) { 523 callout_stop(&d->bd_callout); 524 d->bd_state = BPF_IDLE; 525 } 526 wakeup(d); 527 if (d->bd_async && d->bd_sig && d->bd_sigio) 528 pgsigio(&d->bd_sigio, d->bd_sig, 0); 529 530 selwakeuppri(&d->bd_sel, PRINET); 531 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 532 } 533 534 static void 535 bpf_timed_out(arg) 536 void *arg; 537 { 538 struct bpf_d *d = (struct bpf_d *)arg; 539 540 BPFD_LOCK(d); 541 if (d->bd_state == BPF_WAITING) { 542 d->bd_state = BPF_TIMED_OUT; 543 if (d->bd_slen != 0) 544 bpf_wakeup(d); 545 } 546 BPFD_UNLOCK(d); 547 } 548 549 static int 550 bpfwrite(dev, uio, ioflag) 551 struct cdev *dev; 552 struct uio *uio; 553 int ioflag; 554 { 555 struct bpf_d *d = dev->si_drv1; 556 struct ifnet *ifp; 557 struct mbuf *m; 558 int error; 559 struct sockaddr dst; 560 int datlen; 561 562 if (d->bd_bif == NULL) 563 return (ENXIO); 564 565 ifp = d->bd_bif->bif_ifp; 566 567 if (uio->uio_resid == 0) 568 return (0); 569 570 bzero(&dst, sizeof(dst)); 571 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 572 if (error) 573 return (error); 574 575 if (datlen > ifp->if_mtu) 576 return (EMSGSIZE); 577 578 if (d->bd_hdrcmplt) 579 dst.sa_family = pseudo_AF_HDRCMPLT; 580 581 #ifdef MAC 582 BPFD_LOCK(d); 583 mac_create_mbuf_from_bpfdesc(d, m); 584 BPFD_UNLOCK(d); 585 #endif 586 NET_LOCK_GIANT(); 587 error = (*ifp->if_output)(ifp, m, &dst, NULL); 588 NET_UNLOCK_GIANT(); 589 /* 590 * The driver frees the mbuf. 591 */ 592 return (error); 593 } 594 595 /* 596 * Reset a descriptor by flushing its packet buffer and clearing the 597 * receive and drop counts. 598 */ 599 static void 600 reset_d(d) 601 struct bpf_d *d; 602 { 603 604 mtx_assert(&d->bd_mtx, MA_OWNED); 605 if (d->bd_hbuf) { 606 /* Free the hold buffer. */ 607 d->bd_fbuf = d->bd_hbuf; 608 d->bd_hbuf = NULL; 609 } 610 d->bd_slen = 0; 611 d->bd_hlen = 0; 612 d->bd_rcount = 0; 613 d->bd_dcount = 0; 614 } 615 616 /* 617 * FIONREAD Check for read packet available. 618 * SIOCGIFADDR Get interface address - convenient hook to driver. 619 * BIOCGBLEN Get buffer len [for read()]. 620 * BIOCSETF Set ethernet read filter. 621 * BIOCFLUSH Flush read packet buffer. 622 * BIOCPROMISC Put interface into promiscuous mode. 623 * BIOCGDLT Get link layer type. 624 * BIOCGETIF Get interface name. 625 * BIOCSETIF Set interface. 626 * BIOCSRTIMEOUT Set read timeout. 627 * BIOCGRTIMEOUT Get read timeout. 628 * BIOCGSTATS Get packet stats. 629 * BIOCIMMEDIATE Set immediate mode. 630 * BIOCVERSION Get filter language version. 631 * BIOCGHDRCMPLT Get "header already complete" flag 632 * BIOCSHDRCMPLT Set "header already complete" flag 633 * BIOCGSEESENT Get "see packets sent" flag 634 * BIOCSSEESENT Set "see packets sent" flag 635 */ 636 /* ARGSUSED */ 637 static int 638 bpfioctl(dev, cmd, addr, flags, td) 639 struct cdev *dev; 640 u_long cmd; 641 caddr_t addr; 642 int flags; 643 struct thread *td; 644 { 645 struct bpf_d *d = dev->si_drv1; 646 int error = 0; 647 648 BPFD_LOCK(d); 649 if (d->bd_state == BPF_WAITING) 650 callout_stop(&d->bd_callout); 651 d->bd_state = BPF_IDLE; 652 BPFD_UNLOCK(d); 653 654 switch (cmd) { 655 656 default: 657 error = EINVAL; 658 break; 659 660 /* 661 * Check for read packet available. 662 */ 663 case FIONREAD: 664 { 665 int n; 666 667 BPFD_LOCK(d); 668 n = d->bd_slen; 669 if (d->bd_hbuf) 670 n += d->bd_hlen; 671 BPFD_UNLOCK(d); 672 673 *(int *)addr = n; 674 break; 675 } 676 677 case SIOCGIFADDR: 678 { 679 struct ifnet *ifp; 680 681 if (d->bd_bif == NULL) 682 error = EINVAL; 683 else { 684 ifp = d->bd_bif->bif_ifp; 685 error = (*ifp->if_ioctl)(ifp, cmd, addr); 686 } 687 break; 688 } 689 690 /* 691 * Get buffer len [for read()]. 692 */ 693 case BIOCGBLEN: 694 *(u_int *)addr = d->bd_bufsize; 695 break; 696 697 /* 698 * Set buffer length. 699 */ 700 case BIOCSBLEN: 701 if (d->bd_bif != NULL) 702 error = EINVAL; 703 else { 704 u_int size = *(u_int *)addr; 705 706 if (size > bpf_maxbufsize) 707 *(u_int *)addr = size = bpf_maxbufsize; 708 else if (size < BPF_MINBUFSIZE) 709 *(u_int *)addr = size = BPF_MINBUFSIZE; 710 d->bd_bufsize = size; 711 } 712 break; 713 714 /* 715 * Set link layer read filter. 716 */ 717 case BIOCSETF: 718 error = bpf_setf(d, (struct bpf_program *)addr); 719 break; 720 721 /* 722 * Flush read packet buffer. 723 */ 724 case BIOCFLUSH: 725 BPFD_LOCK(d); 726 reset_d(d); 727 BPFD_UNLOCK(d); 728 break; 729 730 /* 731 * Put interface into promiscuous mode. 732 */ 733 case BIOCPROMISC: 734 if (d->bd_bif == NULL) { 735 /* 736 * No interface attached yet. 737 */ 738 error = EINVAL; 739 break; 740 } 741 if (d->bd_promisc == 0) { 742 mtx_lock(&Giant); 743 error = ifpromisc(d->bd_bif->bif_ifp, 1); 744 mtx_unlock(&Giant); 745 if (error == 0) 746 d->bd_promisc = 1; 747 } 748 break; 749 750 /* 751 * Get current data link type. 752 */ 753 case BIOCGDLT: 754 if (d->bd_bif == NULL) 755 error = EINVAL; 756 else 757 *(u_int *)addr = d->bd_bif->bif_dlt; 758 break; 759 760 /* 761 * Get a list of supported data link types. 762 */ 763 case BIOCGDLTLIST: 764 if (d->bd_bif == NULL) 765 error = EINVAL; 766 else 767 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 768 break; 769 770 /* 771 * Set data link type. 772 */ 773 case BIOCSDLT: 774 if (d->bd_bif == NULL) 775 error = EINVAL; 776 else 777 error = bpf_setdlt(d, *(u_int *)addr); 778 break; 779 780 /* 781 * Get interface name. 782 */ 783 case BIOCGETIF: 784 if (d->bd_bif == NULL) 785 error = EINVAL; 786 else { 787 struct ifnet *const ifp = d->bd_bif->bif_ifp; 788 struct ifreq *const ifr = (struct ifreq *)addr; 789 790 strlcpy(ifr->ifr_name, ifp->if_xname, 791 sizeof(ifr->ifr_name)); 792 } 793 break; 794 795 /* 796 * Set interface. 797 */ 798 case BIOCSETIF: 799 error = bpf_setif(d, (struct ifreq *)addr); 800 break; 801 802 /* 803 * Set read timeout. 804 */ 805 case BIOCSRTIMEOUT: 806 { 807 struct timeval *tv = (struct timeval *)addr; 808 809 /* 810 * Subtract 1 tick from tvtohz() since this isn't 811 * a one-shot timer. 812 */ 813 if ((error = itimerfix(tv)) == 0) 814 d->bd_rtout = tvtohz(tv) - 1; 815 break; 816 } 817 818 /* 819 * Get read timeout. 820 */ 821 case BIOCGRTIMEOUT: 822 { 823 struct timeval *tv = (struct timeval *)addr; 824 825 tv->tv_sec = d->bd_rtout / hz; 826 tv->tv_usec = (d->bd_rtout % hz) * tick; 827 break; 828 } 829 830 /* 831 * Get packet stats. 832 */ 833 case BIOCGSTATS: 834 { 835 struct bpf_stat *bs = (struct bpf_stat *)addr; 836 837 bs->bs_recv = d->bd_rcount; 838 bs->bs_drop = d->bd_dcount; 839 break; 840 } 841 842 /* 843 * Set immediate mode. 844 */ 845 case BIOCIMMEDIATE: 846 d->bd_immediate = *(u_int *)addr; 847 break; 848 849 case BIOCVERSION: 850 { 851 struct bpf_version *bv = (struct bpf_version *)addr; 852 853 bv->bv_major = BPF_MAJOR_VERSION; 854 bv->bv_minor = BPF_MINOR_VERSION; 855 break; 856 } 857 858 /* 859 * Get "header already complete" flag 860 */ 861 case BIOCGHDRCMPLT: 862 *(u_int *)addr = d->bd_hdrcmplt; 863 break; 864 865 /* 866 * Set "header already complete" flag 867 */ 868 case BIOCSHDRCMPLT: 869 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 870 break; 871 872 /* 873 * Get "see sent packets" flag 874 */ 875 case BIOCGSEESENT: 876 *(u_int *)addr = d->bd_seesent; 877 break; 878 879 /* 880 * Set "see sent packets" flag 881 */ 882 case BIOCSSEESENT: 883 d->bd_seesent = *(u_int *)addr; 884 break; 885 886 case FIONBIO: /* Non-blocking I/O */ 887 break; 888 889 case FIOASYNC: /* Send signal on receive packets */ 890 d->bd_async = *(int *)addr; 891 break; 892 893 case FIOSETOWN: 894 error = fsetown(*(int *)addr, &d->bd_sigio); 895 break; 896 897 case FIOGETOWN: 898 *(int *)addr = fgetown(&d->bd_sigio); 899 break; 900 901 /* This is deprecated, FIOSETOWN should be used instead. */ 902 case TIOCSPGRP: 903 error = fsetown(-(*(int *)addr), &d->bd_sigio); 904 break; 905 906 /* This is deprecated, FIOGETOWN should be used instead. */ 907 case TIOCGPGRP: 908 *(int *)addr = -fgetown(&d->bd_sigio); 909 break; 910 911 case BIOCSRSIG: /* Set receive signal */ 912 { 913 u_int sig; 914 915 sig = *(u_int *)addr; 916 917 if (sig >= NSIG) 918 error = EINVAL; 919 else 920 d->bd_sig = sig; 921 break; 922 } 923 case BIOCGRSIG: 924 *(u_int *)addr = d->bd_sig; 925 break; 926 } 927 return (error); 928 } 929 930 /* 931 * Set d's packet filter program to fp. If this file already has a filter, 932 * free it and replace it. Returns EINVAL for bogus requests. 933 */ 934 static int 935 bpf_setf(d, fp) 936 struct bpf_d *d; 937 struct bpf_program *fp; 938 { 939 struct bpf_insn *fcode, *old; 940 u_int flen, size; 941 942 old = d->bd_filter; 943 if (fp->bf_insns == NULL) { 944 if (fp->bf_len != 0) 945 return (EINVAL); 946 BPFD_LOCK(d); 947 d->bd_filter = NULL; 948 reset_d(d); 949 BPFD_UNLOCK(d); 950 if (old != NULL) 951 free((caddr_t)old, M_BPF); 952 return (0); 953 } 954 flen = fp->bf_len; 955 if (flen > BPF_MAXINSNS) 956 return (EINVAL); 957 958 size = flen * sizeof(*fp->bf_insns); 959 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 960 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 961 bpf_validate(fcode, (int)flen)) { 962 BPFD_LOCK(d); 963 d->bd_filter = fcode; 964 reset_d(d); 965 BPFD_UNLOCK(d); 966 if (old != NULL) 967 free((caddr_t)old, M_BPF); 968 969 return (0); 970 } 971 free((caddr_t)fcode, M_BPF); 972 return (EINVAL); 973 } 974 975 /* 976 * Detach a file from its current interface (if attached at all) and attach 977 * to the interface indicated by the name stored in ifr. 978 * Return an errno or 0. 979 */ 980 static int 981 bpf_setif(d, ifr) 982 struct bpf_d *d; 983 struct ifreq *ifr; 984 { 985 struct bpf_if *bp; 986 int error; 987 struct ifnet *theywant; 988 989 theywant = ifunit(ifr->ifr_name); 990 if (theywant == NULL) 991 return ENXIO; 992 993 /* 994 * Look through attached interfaces for the named one. 995 */ 996 mtx_lock(&bpf_mtx); 997 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 998 struct ifnet *ifp = bp->bif_ifp; 999 1000 if (ifp == NULL || ifp != theywant) 1001 continue; 1002 /* skip additional entry */ 1003 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 1004 continue; 1005 1006 mtx_unlock(&bpf_mtx); 1007 /* 1008 * We found the requested interface. 1009 * If it's not up, return an error. 1010 * Allocate the packet buffers if we need to. 1011 * If we're already attached to requested interface, 1012 * just flush the buffer. 1013 */ 1014 if ((ifp->if_flags & IFF_UP) == 0) 1015 return (ENETDOWN); 1016 1017 if (d->bd_sbuf == NULL) { 1018 error = bpf_allocbufs(d); 1019 if (error != 0) 1020 return (error); 1021 } 1022 if (bp != d->bd_bif) { 1023 if (d->bd_bif) 1024 /* 1025 * Detach if attached to something else. 1026 */ 1027 bpf_detachd(d); 1028 1029 bpf_attachd(d, bp); 1030 } 1031 BPFD_LOCK(d); 1032 reset_d(d); 1033 BPFD_UNLOCK(d); 1034 return (0); 1035 } 1036 mtx_unlock(&bpf_mtx); 1037 /* Not found. */ 1038 return (ENXIO); 1039 } 1040 1041 /* 1042 * Support for select() and poll() system calls 1043 * 1044 * Return true iff the specific operation will not block indefinitely. 1045 * Otherwise, return false but make a note that a selwakeup() must be done. 1046 */ 1047 static int 1048 bpfpoll(dev, events, td) 1049 struct cdev *dev; 1050 int events; 1051 struct thread *td; 1052 { 1053 struct bpf_d *d; 1054 int revents; 1055 1056 d = dev->si_drv1; 1057 if (d->bd_bif == NULL) 1058 return (ENXIO); 1059 1060 revents = events & (POLLOUT | POLLWRNORM); 1061 BPFD_LOCK(d); 1062 if (events & (POLLIN | POLLRDNORM)) { 1063 if (bpf_ready(d)) 1064 revents |= events & (POLLIN | POLLRDNORM); 1065 else { 1066 selrecord(td, &d->bd_sel); 1067 /* Start the read timeout if necessary. */ 1068 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1069 callout_reset(&d->bd_callout, d->bd_rtout, 1070 bpf_timed_out, d); 1071 d->bd_state = BPF_WAITING; 1072 } 1073 } 1074 } 1075 BPFD_UNLOCK(d); 1076 return (revents); 1077 } 1078 1079 /* 1080 * Support for kevent() system call. Register EVFILT_READ filters and 1081 * reject all others. 1082 */ 1083 int 1084 bpfkqfilter(dev, kn) 1085 struct cdev *dev; 1086 struct knote *kn; 1087 { 1088 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1089 1090 if (kn->kn_filter != EVFILT_READ) 1091 return (1); 1092 1093 kn->kn_fop = &bpfread_filtops; 1094 kn->kn_hook = d; 1095 knlist_add(&d->bd_sel.si_note, kn, 0); 1096 1097 return (0); 1098 } 1099 1100 static void 1101 filt_bpfdetach(kn) 1102 struct knote *kn; 1103 { 1104 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1105 1106 knlist_remove(&d->bd_sel.si_note, kn, 0); 1107 } 1108 1109 static int 1110 filt_bpfread(kn, hint) 1111 struct knote *kn; 1112 long hint; 1113 { 1114 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1115 int ready; 1116 1117 BPFD_LOCK(d); 1118 ready = bpf_ready(d); 1119 if (ready) { 1120 kn->kn_data = d->bd_slen; 1121 if (d->bd_hbuf) 1122 kn->kn_data += d->bd_hlen; 1123 } 1124 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1125 callout_reset(&d->bd_callout, d->bd_rtout, 1126 bpf_timed_out, d); 1127 d->bd_state = BPF_WAITING; 1128 } 1129 BPFD_UNLOCK(d); 1130 1131 return (ready); 1132 } 1133 1134 /* 1135 * Incoming linkage from device drivers. Process the packet pkt, of length 1136 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1137 * by each process' filter, and if accepted, stashed into the corresponding 1138 * buffer. 1139 */ 1140 void 1141 bpf_tap(bp, pkt, pktlen) 1142 struct bpf_if *bp; 1143 u_char *pkt; 1144 u_int pktlen; 1145 { 1146 struct bpf_d *d; 1147 u_int slen; 1148 1149 /* 1150 * Lockless read to avoid cost of locking the interface if there are 1151 * no descriptors attached. 1152 */ 1153 if (LIST_EMPTY(&bp->bif_dlist)) 1154 return; 1155 1156 BPFIF_LOCK(bp); 1157 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1158 BPFD_LOCK(d); 1159 ++d->bd_rcount; 1160 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1161 if (slen != 0) { 1162 #ifdef MAC 1163 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1164 #endif 1165 catchpacket(d, pkt, pktlen, slen, bcopy); 1166 } 1167 BPFD_UNLOCK(d); 1168 } 1169 BPFIF_UNLOCK(bp); 1170 } 1171 1172 /* 1173 * Copy data from an mbuf chain into a buffer. This code is derived 1174 * from m_copydata in sys/uipc_mbuf.c. 1175 */ 1176 static void 1177 bpf_mcopy(src_arg, dst_arg, len) 1178 const void *src_arg; 1179 void *dst_arg; 1180 size_t len; 1181 { 1182 const struct mbuf *m; 1183 u_int count; 1184 u_char *dst; 1185 1186 m = src_arg; 1187 dst = dst_arg; 1188 while (len > 0) { 1189 if (m == NULL) 1190 panic("bpf_mcopy"); 1191 count = min(m->m_len, len); 1192 bcopy(mtod(m, void *), dst, count); 1193 m = m->m_next; 1194 dst += count; 1195 len -= count; 1196 } 1197 } 1198 1199 /* 1200 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1201 */ 1202 void 1203 bpf_mtap(bp, m) 1204 struct bpf_if *bp; 1205 struct mbuf *m; 1206 { 1207 struct bpf_d *d; 1208 u_int pktlen, slen; 1209 1210 /* 1211 * Lockless read to avoid cost of locking the interface if there are 1212 * no descriptors attached. 1213 */ 1214 if (LIST_EMPTY(&bp->bif_dlist)) 1215 return; 1216 1217 pktlen = m_length(m, NULL); 1218 if (pktlen == m->m_len) { 1219 bpf_tap(bp, mtod(m, u_char *), pktlen); 1220 return; 1221 } 1222 1223 BPFIF_LOCK(bp); 1224 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1225 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1226 continue; 1227 BPFD_LOCK(d); 1228 ++d->bd_rcount; 1229 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1230 if (slen != 0) 1231 #ifdef MAC 1232 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1233 #endif 1234 catchpacket(d, (u_char *)m, pktlen, slen, 1235 bpf_mcopy); 1236 BPFD_UNLOCK(d); 1237 } 1238 BPFIF_UNLOCK(bp); 1239 } 1240 1241 /* 1242 * Incoming linkage from device drivers, when packet is in 1243 * an mbuf chain and to be prepended by a contiguous header. 1244 */ 1245 void 1246 bpf_mtap2(bp, data, dlen, m) 1247 struct bpf_if *bp; 1248 void *data; 1249 u_int dlen; 1250 struct mbuf *m; 1251 { 1252 struct mbuf mb; 1253 struct bpf_d *d; 1254 u_int pktlen, slen; 1255 1256 /* 1257 * Lockless read to avoid cost of locking the interface if there are 1258 * no descriptors attached. 1259 */ 1260 if (LIST_EMPTY(&bp->bif_dlist)) 1261 return; 1262 1263 pktlen = m_length(m, NULL); 1264 /* 1265 * Craft on-stack mbuf suitable for passing to bpf_filter. 1266 * Note that we cut corners here; we only setup what's 1267 * absolutely needed--this mbuf should never go anywhere else. 1268 */ 1269 mb.m_next = m; 1270 mb.m_data = data; 1271 mb.m_len = dlen; 1272 pktlen += dlen; 1273 1274 BPFIF_LOCK(bp); 1275 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1276 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1277 continue; 1278 BPFD_LOCK(d); 1279 ++d->bd_rcount; 1280 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0); 1281 if (slen != 0) 1282 #ifdef MAC 1283 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1284 #endif 1285 catchpacket(d, (u_char *)&mb, pktlen, slen, 1286 bpf_mcopy); 1287 BPFD_UNLOCK(d); 1288 } 1289 BPFIF_UNLOCK(bp); 1290 } 1291 1292 /* 1293 * Move the packet data from interface memory (pkt) into the 1294 * store buffer. "cpfn" is the routine called to do the actual data 1295 * transfer. bcopy is passed in to copy contiguous chunks, while 1296 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1297 * pkt is really an mbuf. 1298 */ 1299 static void 1300 catchpacket(d, pkt, pktlen, snaplen, cpfn) 1301 struct bpf_d *d; 1302 u_char *pkt; 1303 u_int pktlen, snaplen; 1304 void (*cpfn)(const void *, void *, size_t); 1305 { 1306 struct bpf_hdr *hp; 1307 int totlen, curlen; 1308 int hdrlen = d->bd_bif->bif_hdrlen; 1309 1310 /* 1311 * Figure out how many bytes to move. If the packet is 1312 * greater or equal to the snapshot length, transfer that 1313 * much. Otherwise, transfer the whole packet (unless 1314 * we hit the buffer size limit). 1315 */ 1316 totlen = hdrlen + min(snaplen, pktlen); 1317 if (totlen > d->bd_bufsize) 1318 totlen = d->bd_bufsize; 1319 1320 /* 1321 * Round up the end of the previous packet to the next longword. 1322 */ 1323 curlen = BPF_WORDALIGN(d->bd_slen); 1324 if (curlen + totlen > d->bd_bufsize) { 1325 /* 1326 * This packet will overflow the storage buffer. 1327 * Rotate the buffers if we can, then wakeup any 1328 * pending reads. 1329 */ 1330 if (d->bd_fbuf == NULL) { 1331 /* 1332 * We haven't completed the previous read yet, 1333 * so drop the packet. 1334 */ 1335 ++d->bd_dcount; 1336 return; 1337 } 1338 ROTATE_BUFFERS(d); 1339 bpf_wakeup(d); 1340 curlen = 0; 1341 } 1342 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1343 /* 1344 * Immediate mode is set, or the read timeout has 1345 * already expired during a select call. A packet 1346 * arrived, so the reader should be woken up. 1347 */ 1348 bpf_wakeup(d); 1349 1350 /* 1351 * Append the bpf header. 1352 */ 1353 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1354 microtime(&hp->bh_tstamp); 1355 hp->bh_datalen = pktlen; 1356 hp->bh_hdrlen = hdrlen; 1357 /* 1358 * Copy the packet data into the store buffer and update its length. 1359 */ 1360 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1361 d->bd_slen = curlen + totlen; 1362 } 1363 1364 /* 1365 * Initialize all nonzero fields of a descriptor. 1366 */ 1367 static int 1368 bpf_allocbufs(d) 1369 struct bpf_d *d; 1370 { 1371 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1372 if (d->bd_fbuf == NULL) 1373 return (ENOBUFS); 1374 1375 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1376 if (d->bd_sbuf == NULL) { 1377 free(d->bd_fbuf, M_BPF); 1378 return (ENOBUFS); 1379 } 1380 d->bd_slen = 0; 1381 d->bd_hlen = 0; 1382 return (0); 1383 } 1384 1385 /* 1386 * Free buffers currently in use by a descriptor. 1387 * Called on close. 1388 */ 1389 static void 1390 bpf_freed(d) 1391 struct bpf_d *d; 1392 { 1393 /* 1394 * We don't need to lock out interrupts since this descriptor has 1395 * been detached from its interface and it yet hasn't been marked 1396 * free. 1397 */ 1398 if (d->bd_sbuf != NULL) { 1399 free(d->bd_sbuf, M_BPF); 1400 if (d->bd_hbuf != NULL) 1401 free(d->bd_hbuf, M_BPF); 1402 if (d->bd_fbuf != NULL) 1403 free(d->bd_fbuf, M_BPF); 1404 } 1405 if (d->bd_filter) 1406 free((caddr_t)d->bd_filter, M_BPF); 1407 mtx_destroy(&d->bd_mtx); 1408 } 1409 1410 /* 1411 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1412 * fixed size of the link header (variable length headers not yet supported). 1413 */ 1414 void 1415 bpfattach(ifp, dlt, hdrlen) 1416 struct ifnet *ifp; 1417 u_int dlt, hdrlen; 1418 { 1419 1420 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1421 } 1422 1423 /* 1424 * Attach an interface to bpf. ifp is a pointer to the structure 1425 * defining the interface to be attached, dlt is the link layer type, 1426 * and hdrlen is the fixed size of the link header (variable length 1427 * headers are not yet supporrted). 1428 */ 1429 void 1430 bpfattach2(ifp, dlt, hdrlen, driverp) 1431 struct ifnet *ifp; 1432 u_int dlt, hdrlen; 1433 struct bpf_if **driverp; 1434 { 1435 struct bpf_if *bp; 1436 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1437 if (bp == NULL) 1438 panic("bpfattach"); 1439 1440 LIST_INIT(&bp->bif_dlist); 1441 bp->bif_driverp = driverp; 1442 bp->bif_ifp = ifp; 1443 bp->bif_dlt = dlt; 1444 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1445 1446 mtx_lock(&bpf_mtx); 1447 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1448 mtx_unlock(&bpf_mtx); 1449 1450 *bp->bif_driverp = NULL; 1451 1452 /* 1453 * Compute the length of the bpf header. This is not necessarily 1454 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1455 * that the network layer header begins on a longword boundary (for 1456 * performance reasons and to alleviate alignment restrictions). 1457 */ 1458 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1459 1460 if (bootverbose) 1461 if_printf(ifp, "bpf attached\n"); 1462 } 1463 1464 /* 1465 * Detach bpf from an interface. This involves detaching each descriptor 1466 * associated with the interface, and leaving bd_bif NULL. Notify each 1467 * descriptor as it's detached so that any sleepers wake up and get 1468 * ENXIO. 1469 */ 1470 void 1471 bpfdetach(ifp) 1472 struct ifnet *ifp; 1473 { 1474 struct bpf_if *bp; 1475 struct bpf_d *d; 1476 1477 /* Locate BPF interface information */ 1478 mtx_lock(&bpf_mtx); 1479 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1480 if (ifp == bp->bif_ifp) 1481 break; 1482 } 1483 1484 /* Interface wasn't attached */ 1485 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1486 mtx_unlock(&bpf_mtx); 1487 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1488 return; 1489 } 1490 1491 LIST_REMOVE(bp, bif_next); 1492 mtx_unlock(&bpf_mtx); 1493 1494 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1495 bpf_detachd(d); 1496 BPFD_LOCK(d); 1497 bpf_wakeup(d); 1498 BPFD_UNLOCK(d); 1499 } 1500 1501 mtx_destroy(&bp->bif_mtx); 1502 free(bp, M_BPF); 1503 } 1504 1505 /* 1506 * Get a list of available data link type of the interface. 1507 */ 1508 static int 1509 bpf_getdltlist(d, bfl) 1510 struct bpf_d *d; 1511 struct bpf_dltlist *bfl; 1512 { 1513 int n, error; 1514 struct ifnet *ifp; 1515 struct bpf_if *bp; 1516 1517 ifp = d->bd_bif->bif_ifp; 1518 n = 0; 1519 error = 0; 1520 mtx_lock(&bpf_mtx); 1521 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1522 if (bp->bif_ifp != ifp) 1523 continue; 1524 if (bfl->bfl_list != NULL) { 1525 if (n >= bfl->bfl_len) { 1526 mtx_unlock(&bpf_mtx); 1527 return (ENOMEM); 1528 } 1529 error = copyout(&bp->bif_dlt, 1530 bfl->bfl_list + n, sizeof(u_int)); 1531 } 1532 n++; 1533 } 1534 mtx_unlock(&bpf_mtx); 1535 bfl->bfl_len = n; 1536 return (error); 1537 } 1538 1539 /* 1540 * Set the data link type of a BPF instance. 1541 */ 1542 static int 1543 bpf_setdlt(d, dlt) 1544 struct bpf_d *d; 1545 u_int dlt; 1546 { 1547 int error, opromisc; 1548 struct ifnet *ifp; 1549 struct bpf_if *bp; 1550 1551 if (d->bd_bif->bif_dlt == dlt) 1552 return (0); 1553 ifp = d->bd_bif->bif_ifp; 1554 mtx_lock(&bpf_mtx); 1555 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1556 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1557 break; 1558 } 1559 mtx_unlock(&bpf_mtx); 1560 if (bp != NULL) { 1561 opromisc = d->bd_promisc; 1562 bpf_detachd(d); 1563 bpf_attachd(d, bp); 1564 BPFD_LOCK(d); 1565 reset_d(d); 1566 BPFD_UNLOCK(d); 1567 if (opromisc) { 1568 error = ifpromisc(bp->bif_ifp, 1); 1569 if (error) 1570 if_printf(bp->bif_ifp, 1571 "bpf_setdlt: ifpromisc failed (%d)\n", 1572 error); 1573 else 1574 d->bd_promisc = 1; 1575 } 1576 } 1577 return (bp == NULL ? EINVAL : 0); 1578 } 1579 1580 static void bpf_drvinit(void *unused); 1581 1582 static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev); 1583 1584 static void 1585 bpf_clone(arg, name, namelen, dev) 1586 void *arg; 1587 char *name; 1588 int namelen; 1589 struct cdev **dev; 1590 { 1591 int u; 1592 1593 if (*dev != NULL) 1594 return; 1595 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1596 return; 1597 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1598 "bpf%d", u); 1599 (*dev)->si_flags |= SI_CHEAPCLONE; 1600 return; 1601 } 1602 1603 static void 1604 bpf_drvinit(unused) 1605 void *unused; 1606 { 1607 1608 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1609 LIST_INIT(&bpf_iflist); 1610 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1611 } 1612 1613 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1614 1615 #else /* !DEV_BPF && !NETGRAPH_BPF */ 1616 /* 1617 * NOP stubs to allow bpf-using drivers to load and function. 1618 * 1619 * A 'better' implementation would allow the core bpf functionality 1620 * to be loaded at runtime. 1621 */ 1622 1623 void 1624 bpf_tap(bp, pkt, pktlen) 1625 struct bpf_if *bp; 1626 u_char *pkt; 1627 u_int pktlen; 1628 { 1629 } 1630 1631 void 1632 bpf_mtap(bp, m) 1633 struct bpf_if *bp; 1634 struct mbuf *m; 1635 { 1636 } 1637 1638 void 1639 bpf_mtap2(bp, d, l, m) 1640 struct bpf_if *bp; 1641 void *d; 1642 u_int l; 1643 struct mbuf *m; 1644 { 1645 } 1646 1647 void 1648 bpfattach(ifp, dlt, hdrlen) 1649 struct ifnet *ifp; 1650 u_int dlt, hdrlen; 1651 { 1652 } 1653 1654 void 1655 bpfattach2(ifp, dlt, hdrlen, driverp) 1656 struct ifnet *ifp; 1657 u_int dlt, hdrlen; 1658 struct bpf_if **driverp; 1659 { 1660 } 1661 1662 void 1663 bpfdetach(ifp) 1664 struct ifnet *ifp; 1665 { 1666 } 1667 1668 u_int 1669 bpf_filter(pc, p, wirelen, buflen) 1670 const struct bpf_insn *pc; 1671 u_char *p; 1672 u_int wirelen; 1673 u_int buflen; 1674 { 1675 return -1; /* "no filter" behaviour */ 1676 } 1677 1678 int 1679 bpf_validate(f, len) 1680 const struct bpf_insn *f; 1681 int len; 1682 { 1683 return 0; /* false */ 1684 } 1685 1686 #endif /* !DEV_BPF && !NETGRAPH_BPF */
Cache object: 0814534f46907940d91b7270c8d81539
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