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 * $FreeBSD$ 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 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 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 */ 97 static LIST_HEAD(, bpf_if) bpf_iflist; 98 static struct mtx bpf_mtx; /* bpf global lock */ 99 100 static int bpf_allocbufs(struct bpf_d *); 101 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 102 static void bpf_detachd(struct bpf_d *d); 103 static void bpf_freed(struct bpf_d *); 104 static void bpf_mcopy(const void *, void *, size_t); 105 static int bpf_movein(struct uio *, int, 106 struct mbuf **, struct sockaddr *, int *); 107 static int bpf_setif(struct bpf_d *, struct ifreq *); 108 static void bpf_timed_out(void *); 109 static __inline void 110 bpf_wakeup(struct bpf_d *); 111 static void catchpacket(struct bpf_d *, u_char *, u_int, 112 u_int, void (*)(const void *, void *, size_t)); 113 static void reset_d(struct bpf_d *); 114 static int bpf_setf(struct bpf_d *, struct bpf_program *); 115 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 116 static int bpf_setdlt(struct bpf_d *, u_int); 117 static void filt_bpfdetach(struct knote *); 118 static int filt_bpfread(struct knote *, long); 119 120 static d_open_t bpfopen; 121 static d_close_t bpfclose; 122 static d_read_t bpfread; 123 static d_write_t bpfwrite; 124 static d_ioctl_t bpfioctl; 125 static d_poll_t bpfpoll; 126 static d_kqfilter_t bpfkqfilter; 127 128 static 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 }; 140 141 static struct filterops bpfread_filtops = 142 { 1, NULL, filt_bpfdetach, filt_bpfread }; 143 144 static int 145 bpf_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); 242 bad: 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 */ 250 static void 251 bpf_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 */ 271 static void 272 bpf_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 */ 324 static int 325 bpfopen(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 */ 370 static int 371 bpfclose(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 selwakeuppri(&d->bd_sel, PRINET); 390 #ifdef MAC 391 mac_destroy_bpfdesc(d); 392 #endif /* MAC */ 393 knlist_destroy(&d->bd_sel.si_note); 394 bpf_freed(d); 395 dev->si_drv1 = NULL; 396 free(d, M_BPF); 397 398 return (0); 399 } 400 401 402 /* 403 * Rotate the packet buffers in descriptor d. Move the store buffer 404 * into the hold slot, and the free buffer into the store slot. 405 * Zero the length of the new store buffer. 406 */ 407 #define ROTATE_BUFFERS(d) \ 408 (d)->bd_hbuf = (d)->bd_sbuf; \ 409 (d)->bd_hlen = (d)->bd_slen; \ 410 (d)->bd_sbuf = (d)->bd_fbuf; \ 411 (d)->bd_slen = 0; \ 412 (d)->bd_fbuf = NULL; 413 /* 414 * bpfread - read next chunk of packets from buffers 415 */ 416 static int 417 bpfread(dev, uio, ioflag) 418 struct cdev *dev; 419 struct uio *uio; 420 int ioflag; 421 { 422 struct bpf_d *d = dev->si_drv1; 423 int timed_out; 424 int error; 425 426 /* 427 * Restrict application to use a buffer the same size as 428 * as kernel buffers. 429 */ 430 if (uio->uio_resid != d->bd_bufsize) 431 return (EINVAL); 432 433 BPFD_LOCK(d); 434 if (d->bd_state == BPF_WAITING) 435 callout_stop(&d->bd_callout); 436 timed_out = (d->bd_state == BPF_TIMED_OUT); 437 d->bd_state = BPF_IDLE; 438 /* 439 * If the hold buffer is empty, then do a timed sleep, which 440 * ends when the timeout expires or when enough packets 441 * have arrived to fill the store buffer. 442 */ 443 while (d->bd_hbuf == NULL) { 444 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 445 /* 446 * A packet(s) either arrived since the previous 447 * read or arrived while we were asleep. 448 * Rotate the buffers and return what's here. 449 */ 450 ROTATE_BUFFERS(d); 451 break; 452 } 453 454 /* 455 * No data is available, check to see if the bpf device 456 * is still pointed at a real interface. If not, return 457 * ENXIO so that the userland process knows to rebind 458 * it before using it again. 459 */ 460 if (d->bd_bif == NULL) { 461 BPFD_UNLOCK(d); 462 return (ENXIO); 463 } 464 465 if (ioflag & O_NONBLOCK) { 466 BPFD_UNLOCK(d); 467 return (EWOULDBLOCK); 468 } 469 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 470 "bpf", d->bd_rtout); 471 if (error == EINTR || error == ERESTART) { 472 BPFD_UNLOCK(d); 473 return (error); 474 } 475 if (error == EWOULDBLOCK) { 476 /* 477 * On a timeout, return what's in the buffer, 478 * which may be nothing. If there is something 479 * in the store buffer, we can rotate the buffers. 480 */ 481 if (d->bd_hbuf) 482 /* 483 * We filled up the buffer in between 484 * getting the timeout and arriving 485 * here, so we don't need to rotate. 486 */ 487 break; 488 489 if (d->bd_slen == 0) { 490 BPFD_UNLOCK(d); 491 return (0); 492 } 493 ROTATE_BUFFERS(d); 494 break; 495 } 496 } 497 /* 498 * At this point, we know we have something in the hold slot. 499 */ 500 BPFD_UNLOCK(d); 501 502 /* 503 * Move data from hold buffer into user space. 504 * We know the entire buffer is transferred since 505 * we checked above that the read buffer is bpf_bufsize bytes. 506 */ 507 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 508 509 BPFD_LOCK(d); 510 d->bd_fbuf = d->bd_hbuf; 511 d->bd_hbuf = NULL; 512 d->bd_hlen = 0; 513 BPFD_UNLOCK(d); 514 515 return (error); 516 } 517 518 519 /* 520 * If there are processes sleeping on this descriptor, wake them up. 521 */ 522 static __inline void 523 bpf_wakeup(d) 524 struct bpf_d *d; 525 { 526 if (d->bd_state == BPF_WAITING) { 527 callout_stop(&d->bd_callout); 528 d->bd_state = BPF_IDLE; 529 } 530 wakeup(d); 531 if (d->bd_async && d->bd_sig && d->bd_sigio) 532 pgsigio(&d->bd_sigio, d->bd_sig, 0); 533 534 selwakeuppri(&d->bd_sel, PRINET); 535 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 536 } 537 538 static void 539 bpf_timed_out(arg) 540 void *arg; 541 { 542 struct bpf_d *d = (struct bpf_d *)arg; 543 544 BPFD_LOCK(d); 545 if (d->bd_state == BPF_WAITING) { 546 d->bd_state = BPF_TIMED_OUT; 547 if (d->bd_slen != 0) 548 bpf_wakeup(d); 549 } 550 BPFD_UNLOCK(d); 551 } 552 553 static int 554 bpfwrite(dev, uio, ioflag) 555 struct cdev *dev; 556 struct uio *uio; 557 int ioflag; 558 { 559 struct bpf_d *d = dev->si_drv1; 560 struct ifnet *ifp; 561 struct mbuf *m; 562 int error; 563 struct sockaddr dst; 564 int datlen; 565 566 if (d->bd_bif == NULL) 567 return (ENXIO); 568 569 ifp = d->bd_bif->bif_ifp; 570 571 if ((ifp->if_flags & IFF_UP) == 0) 572 return (ENETDOWN); 573 574 if (uio->uio_resid == 0) 575 return (0); 576 577 bzero(&dst, sizeof(dst)); 578 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 579 if (error) 580 return (error); 581 582 if (datlen > ifp->if_mtu) { 583 m_freem(m); 584 return (EMSGSIZE); 585 } 586 587 if (d->bd_hdrcmplt) 588 dst.sa_family = pseudo_AF_HDRCMPLT; 589 590 #ifdef MAC 591 BPFD_LOCK(d); 592 mac_create_mbuf_from_bpfdesc(d, m); 593 BPFD_UNLOCK(d); 594 #endif 595 NET_LOCK_GIANT(); 596 error = (*ifp->if_output)(ifp, m, &dst, NULL); 597 NET_UNLOCK_GIANT(); 598 /* 599 * The driver frees the mbuf. 600 */ 601 return (error); 602 } 603 604 /* 605 * Reset a descriptor by flushing its packet buffer and clearing the 606 * receive and drop counts. 607 */ 608 static void 609 reset_d(d) 610 struct bpf_d *d; 611 { 612 613 mtx_assert(&d->bd_mtx, MA_OWNED); 614 if (d->bd_hbuf) { 615 /* Free the hold buffer. */ 616 d->bd_fbuf = d->bd_hbuf; 617 d->bd_hbuf = NULL; 618 } 619 d->bd_slen = 0; 620 d->bd_hlen = 0; 621 d->bd_rcount = 0; 622 d->bd_dcount = 0; 623 } 624 625 /* 626 * FIONREAD Check for read packet available. 627 * SIOCGIFADDR Get interface address - convenient hook to driver. 628 * BIOCGBLEN Get buffer len [for read()]. 629 * BIOCSETF Set ethernet read filter. 630 * BIOCFLUSH Flush read packet buffer. 631 * BIOCPROMISC Put interface into promiscuous mode. 632 * BIOCGDLT Get link layer type. 633 * BIOCGETIF Get interface name. 634 * BIOCSETIF Set interface. 635 * BIOCSRTIMEOUT Set read timeout. 636 * BIOCGRTIMEOUT Get read timeout. 637 * BIOCGSTATS Get packet stats. 638 * BIOCIMMEDIATE Set immediate mode. 639 * BIOCVERSION Get filter language version. 640 * BIOCGHDRCMPLT Get "header already complete" flag 641 * BIOCSHDRCMPLT Set "header already complete" flag 642 * BIOCGSEESENT Get "see packets sent" flag 643 * BIOCSSEESENT Set "see packets sent" flag 644 */ 645 /* ARGSUSED */ 646 static int 647 bpfioctl(dev, cmd, addr, flags, td) 648 struct cdev *dev; 649 u_long cmd; 650 caddr_t addr; 651 int flags; 652 struct thread *td; 653 { 654 struct bpf_d *d = dev->si_drv1; 655 int error = 0; 656 657 BPFD_LOCK(d); 658 if (d->bd_state == BPF_WAITING) 659 callout_stop(&d->bd_callout); 660 d->bd_state = BPF_IDLE; 661 BPFD_UNLOCK(d); 662 663 switch (cmd) { 664 665 default: 666 error = EINVAL; 667 break; 668 669 /* 670 * Check for read packet available. 671 */ 672 case FIONREAD: 673 { 674 int n; 675 676 BPFD_LOCK(d); 677 n = d->bd_slen; 678 if (d->bd_hbuf) 679 n += d->bd_hlen; 680 BPFD_UNLOCK(d); 681 682 *(int *)addr = n; 683 break; 684 } 685 686 case SIOCGIFADDR: 687 { 688 struct ifnet *ifp; 689 690 if (d->bd_bif == NULL) 691 error = EINVAL; 692 else { 693 ifp = d->bd_bif->bif_ifp; 694 error = (*ifp->if_ioctl)(ifp, cmd, addr); 695 } 696 break; 697 } 698 699 /* 700 * Get buffer len [for read()]. 701 */ 702 case BIOCGBLEN: 703 *(u_int *)addr = d->bd_bufsize; 704 break; 705 706 /* 707 * Set buffer length. 708 */ 709 case BIOCSBLEN: 710 if (d->bd_bif != NULL) 711 error = EINVAL; 712 else { 713 u_int size = *(u_int *)addr; 714 715 if (size > bpf_maxbufsize) 716 *(u_int *)addr = size = bpf_maxbufsize; 717 else if (size < BPF_MINBUFSIZE) 718 *(u_int *)addr = size = BPF_MINBUFSIZE; 719 d->bd_bufsize = size; 720 } 721 break; 722 723 /* 724 * Set link layer read filter. 725 */ 726 case BIOCSETF: 727 error = bpf_setf(d, (struct bpf_program *)addr); 728 break; 729 730 /* 731 * Flush read packet buffer. 732 */ 733 case BIOCFLUSH: 734 BPFD_LOCK(d); 735 reset_d(d); 736 BPFD_UNLOCK(d); 737 break; 738 739 /* 740 * Put interface into promiscuous mode. 741 */ 742 case BIOCPROMISC: 743 if (d->bd_bif == NULL) { 744 /* 745 * No interface attached yet. 746 */ 747 error = EINVAL; 748 break; 749 } 750 if (d->bd_promisc == 0) { 751 mtx_lock(&Giant); 752 error = ifpromisc(d->bd_bif->bif_ifp, 1); 753 mtx_unlock(&Giant); 754 if (error == 0) 755 d->bd_promisc = 1; 756 } 757 break; 758 759 /* 760 * Get current data link type. 761 */ 762 case BIOCGDLT: 763 if (d->bd_bif == NULL) 764 error = EINVAL; 765 else 766 *(u_int *)addr = d->bd_bif->bif_dlt; 767 break; 768 769 /* 770 * Get a list of supported data link types. 771 */ 772 case BIOCGDLTLIST: 773 if (d->bd_bif == NULL) 774 error = EINVAL; 775 else 776 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 777 break; 778 779 /* 780 * Set data link type. 781 */ 782 case BIOCSDLT: 783 if (d->bd_bif == NULL) 784 error = EINVAL; 785 else 786 error = bpf_setdlt(d, *(u_int *)addr); 787 break; 788 789 /* 790 * Get interface name. 791 */ 792 case BIOCGETIF: 793 if (d->bd_bif == NULL) 794 error = EINVAL; 795 else { 796 struct ifnet *const ifp = d->bd_bif->bif_ifp; 797 struct ifreq *const ifr = (struct ifreq *)addr; 798 799 strlcpy(ifr->ifr_name, ifp->if_xname, 800 sizeof(ifr->ifr_name)); 801 } 802 break; 803 804 /* 805 * Set interface. 806 */ 807 case BIOCSETIF: 808 error = bpf_setif(d, (struct ifreq *)addr); 809 break; 810 811 /* 812 * Set read timeout. 813 */ 814 case BIOCSRTIMEOUT: 815 { 816 struct timeval *tv = (struct timeval *)addr; 817 818 /* 819 * Subtract 1 tick from tvtohz() since this isn't 820 * a one-shot timer. 821 */ 822 if ((error = itimerfix(tv)) == 0) 823 d->bd_rtout = tvtohz(tv) - 1; 824 break; 825 } 826 827 /* 828 * Get read timeout. 829 */ 830 case BIOCGRTIMEOUT: 831 { 832 struct timeval *tv = (struct timeval *)addr; 833 834 tv->tv_sec = d->bd_rtout / hz; 835 tv->tv_usec = (d->bd_rtout % hz) * tick; 836 break; 837 } 838 839 /* 840 * Get packet stats. 841 */ 842 case BIOCGSTATS: 843 { 844 struct bpf_stat *bs = (struct bpf_stat *)addr; 845 846 bs->bs_recv = d->bd_rcount; 847 bs->bs_drop = d->bd_dcount; 848 break; 849 } 850 851 /* 852 * Set immediate mode. 853 */ 854 case BIOCIMMEDIATE: 855 d->bd_immediate = *(u_int *)addr; 856 break; 857 858 case BIOCVERSION: 859 { 860 struct bpf_version *bv = (struct bpf_version *)addr; 861 862 bv->bv_major = BPF_MAJOR_VERSION; 863 bv->bv_minor = BPF_MINOR_VERSION; 864 break; 865 } 866 867 /* 868 * Get "header already complete" flag 869 */ 870 case BIOCGHDRCMPLT: 871 *(u_int *)addr = d->bd_hdrcmplt; 872 break; 873 874 /* 875 * Set "header already complete" flag 876 */ 877 case BIOCSHDRCMPLT: 878 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 879 break; 880 881 /* 882 * Get "see sent packets" flag 883 */ 884 case BIOCGSEESENT: 885 *(u_int *)addr = d->bd_seesent; 886 break; 887 888 /* 889 * Set "see sent packets" flag 890 */ 891 case BIOCSSEESENT: 892 d->bd_seesent = *(u_int *)addr; 893 break; 894 895 case FIONBIO: /* Non-blocking I/O */ 896 break; 897 898 case FIOASYNC: /* Send signal on receive packets */ 899 d->bd_async = *(int *)addr; 900 break; 901 902 case FIOSETOWN: 903 error = fsetown(*(int *)addr, &d->bd_sigio); 904 break; 905 906 case FIOGETOWN: 907 *(int *)addr = fgetown(&d->bd_sigio); 908 break; 909 910 /* This is deprecated, FIOSETOWN should be used instead. */ 911 case TIOCSPGRP: 912 error = fsetown(-(*(int *)addr), &d->bd_sigio); 913 break; 914 915 /* This is deprecated, FIOGETOWN should be used instead. */ 916 case TIOCGPGRP: 917 *(int *)addr = -fgetown(&d->bd_sigio); 918 break; 919 920 case BIOCSRSIG: /* Set receive signal */ 921 { 922 u_int sig; 923 924 sig = *(u_int *)addr; 925 926 if (sig >= NSIG) 927 error = EINVAL; 928 else 929 d->bd_sig = sig; 930 break; 931 } 932 case BIOCGRSIG: 933 *(u_int *)addr = d->bd_sig; 934 break; 935 } 936 return (error); 937 } 938 939 /* 940 * Set d's packet filter program to fp. If this file already has a filter, 941 * free it and replace it. Returns EINVAL for bogus requests. 942 */ 943 static int 944 bpf_setf(d, fp) 945 struct bpf_d *d; 946 struct bpf_program *fp; 947 { 948 struct bpf_insn *fcode, *old; 949 u_int flen, size; 950 951 if (fp->bf_insns == NULL) { 952 if (fp->bf_len != 0) 953 return (EINVAL); 954 BPFD_LOCK(d); 955 old = d->bd_filter; 956 d->bd_filter = NULL; 957 reset_d(d); 958 BPFD_UNLOCK(d); 959 if (old != NULL) 960 free((caddr_t)old, M_BPF); 961 return (0); 962 } 963 flen = fp->bf_len; 964 if (flen > BPF_MAXINSNS) 965 return (EINVAL); 966 967 size = flen * sizeof(*fp->bf_insns); 968 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 969 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 970 bpf_validate(fcode, (int)flen)) { 971 BPFD_LOCK(d); 972 old = d->bd_filter; 973 d->bd_filter = fcode; 974 reset_d(d); 975 BPFD_UNLOCK(d); 976 if (old != NULL) 977 free((caddr_t)old, M_BPF); 978 979 return (0); 980 } 981 free((caddr_t)fcode, M_BPF); 982 return (EINVAL); 983 } 984 985 /* 986 * Detach a file from its current interface (if attached at all) and attach 987 * to the interface indicated by the name stored in ifr. 988 * Return an errno or 0. 989 */ 990 static int 991 bpf_setif(d, ifr) 992 struct bpf_d *d; 993 struct ifreq *ifr; 994 { 995 struct bpf_if *bp; 996 int error; 997 struct ifnet *theywant; 998 999 theywant = ifunit(ifr->ifr_name); 1000 if (theywant == NULL) 1001 return ENXIO; 1002 1003 /* 1004 * Look through attached interfaces for the named one. 1005 */ 1006 mtx_lock(&bpf_mtx); 1007 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1008 struct ifnet *ifp = bp->bif_ifp; 1009 1010 if (ifp == NULL || ifp != theywant) 1011 continue; 1012 /* skip additional entry */ 1013 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 1014 continue; 1015 1016 mtx_unlock(&bpf_mtx); 1017 /* 1018 * We found the requested interface. 1019 * Allocate the packet buffers if we need to. 1020 * If we're already attached to requested interface, 1021 * just flush the buffer. 1022 */ 1023 if (d->bd_sbuf == NULL) { 1024 error = bpf_allocbufs(d); 1025 if (error != 0) 1026 return (error); 1027 } 1028 if (bp != d->bd_bif) { 1029 if (d->bd_bif) 1030 /* 1031 * Detach if attached to something else. 1032 */ 1033 bpf_detachd(d); 1034 1035 bpf_attachd(d, bp); 1036 } 1037 BPFD_LOCK(d); 1038 reset_d(d); 1039 BPFD_UNLOCK(d); 1040 return (0); 1041 } 1042 mtx_unlock(&bpf_mtx); 1043 /* Not found. */ 1044 return (ENXIO); 1045 } 1046 1047 /* 1048 * Support for select() and poll() system calls 1049 * 1050 * Return true iff the specific operation will not block indefinitely. 1051 * Otherwise, return false but make a note that a selwakeup() must be done. 1052 */ 1053 static int 1054 bpfpoll(dev, events, td) 1055 struct cdev *dev; 1056 int events; 1057 struct thread *td; 1058 { 1059 struct bpf_d *d; 1060 int revents; 1061 1062 d = dev->si_drv1; 1063 if (d->bd_bif == NULL) 1064 return (ENXIO); 1065 1066 revents = events & (POLLOUT | POLLWRNORM); 1067 BPFD_LOCK(d); 1068 if (events & (POLLIN | POLLRDNORM)) { 1069 if (bpf_ready(d)) 1070 revents |= events & (POLLIN | POLLRDNORM); 1071 else { 1072 selrecord(td, &d->bd_sel); 1073 /* Start the read timeout if necessary. */ 1074 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1075 callout_reset(&d->bd_callout, d->bd_rtout, 1076 bpf_timed_out, d); 1077 d->bd_state = BPF_WAITING; 1078 } 1079 } 1080 } 1081 BPFD_UNLOCK(d); 1082 return (revents); 1083 } 1084 1085 /* 1086 * Support for kevent() system call. Register EVFILT_READ filters and 1087 * reject all others. 1088 */ 1089 int 1090 bpfkqfilter(dev, kn) 1091 struct cdev *dev; 1092 struct knote *kn; 1093 { 1094 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1095 1096 if (kn->kn_filter != EVFILT_READ) 1097 return (1); 1098 1099 kn->kn_fop = &bpfread_filtops; 1100 kn->kn_hook = d; 1101 knlist_add(&d->bd_sel.si_note, kn, 0); 1102 1103 return (0); 1104 } 1105 1106 static void 1107 filt_bpfdetach(kn) 1108 struct knote *kn; 1109 { 1110 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1111 1112 knlist_remove(&d->bd_sel.si_note, kn, 0); 1113 } 1114 1115 static int 1116 filt_bpfread(kn, hint) 1117 struct knote *kn; 1118 long hint; 1119 { 1120 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1121 int ready; 1122 1123 BPFD_LOCK_ASSERT(d); 1124 ready = bpf_ready(d); 1125 if (ready) { 1126 kn->kn_data = d->bd_slen; 1127 if (d->bd_hbuf) 1128 kn->kn_data += d->bd_hlen; 1129 } 1130 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1131 callout_reset(&d->bd_callout, d->bd_rtout, 1132 bpf_timed_out, d); 1133 d->bd_state = BPF_WAITING; 1134 } 1135 1136 return (ready); 1137 } 1138 1139 /* 1140 * Incoming linkage from device drivers. Process the packet pkt, of length 1141 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1142 * by each process' filter, and if accepted, stashed into the corresponding 1143 * buffer. 1144 */ 1145 void 1146 bpf_tap(bp, pkt, pktlen) 1147 struct bpf_if *bp; 1148 u_char *pkt; 1149 u_int pktlen; 1150 { 1151 struct bpf_d *d; 1152 u_int slen; 1153 1154 /* 1155 * Lockless read to avoid cost of locking the interface if there are 1156 * no descriptors attached. 1157 */ 1158 if (LIST_EMPTY(&bp->bif_dlist)) 1159 return; 1160 1161 BPFIF_LOCK(bp); 1162 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1163 BPFD_LOCK(d); 1164 ++d->bd_rcount; 1165 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1166 if (slen != 0) { 1167 #ifdef MAC 1168 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1169 #endif 1170 catchpacket(d, pkt, pktlen, slen, bcopy); 1171 } 1172 BPFD_UNLOCK(d); 1173 } 1174 BPFIF_UNLOCK(bp); 1175 } 1176 1177 /* 1178 * Copy data from an mbuf chain into a buffer. This code is derived 1179 * from m_copydata in sys/uipc_mbuf.c. 1180 */ 1181 static void 1182 bpf_mcopy(src_arg, dst_arg, len) 1183 const void *src_arg; 1184 void *dst_arg; 1185 size_t len; 1186 { 1187 const struct mbuf *m; 1188 u_int count; 1189 u_char *dst; 1190 1191 m = src_arg; 1192 dst = dst_arg; 1193 while (len > 0) { 1194 if (m == NULL) 1195 panic("bpf_mcopy"); 1196 count = min(m->m_len, len); 1197 bcopy(mtod(m, void *), dst, count); 1198 m = m->m_next; 1199 dst += count; 1200 len -= count; 1201 } 1202 } 1203 1204 /* 1205 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1206 */ 1207 void 1208 bpf_mtap(bp, m) 1209 struct bpf_if *bp; 1210 struct mbuf *m; 1211 { 1212 struct bpf_d *d; 1213 u_int pktlen, slen; 1214 1215 /* 1216 * Lockless read to avoid cost of locking the interface if there are 1217 * no descriptors attached. 1218 */ 1219 if (LIST_EMPTY(&bp->bif_dlist)) 1220 return; 1221 1222 pktlen = m_length(m, NULL); 1223 if (pktlen == m->m_len) { 1224 bpf_tap(bp, mtod(m, u_char *), pktlen); 1225 return; 1226 } 1227 1228 BPFIF_LOCK(bp); 1229 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1230 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1231 continue; 1232 BPFD_LOCK(d); 1233 ++d->bd_rcount; 1234 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1235 if (slen != 0) 1236 #ifdef MAC 1237 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1238 #endif 1239 catchpacket(d, (u_char *)m, pktlen, slen, 1240 bpf_mcopy); 1241 BPFD_UNLOCK(d); 1242 } 1243 BPFIF_UNLOCK(bp); 1244 } 1245 1246 /* 1247 * Incoming linkage from device drivers, when packet is in 1248 * an mbuf chain and to be prepended by a contiguous header. 1249 */ 1250 void 1251 bpf_mtap2(bp, data, dlen, m) 1252 struct bpf_if *bp; 1253 void *data; 1254 u_int dlen; 1255 struct mbuf *m; 1256 { 1257 struct mbuf mb; 1258 struct bpf_d *d; 1259 u_int pktlen, slen; 1260 1261 /* 1262 * Lockless read to avoid cost of locking the interface if there are 1263 * no descriptors attached. 1264 */ 1265 if (LIST_EMPTY(&bp->bif_dlist)) 1266 return; 1267 1268 pktlen = m_length(m, NULL); 1269 /* 1270 * Craft on-stack mbuf suitable for passing to bpf_filter. 1271 * Note that we cut corners here; we only setup what's 1272 * absolutely needed--this mbuf should never go anywhere else. 1273 */ 1274 mb.m_next = m; 1275 mb.m_data = data; 1276 mb.m_len = dlen; 1277 pktlen += dlen; 1278 1279 BPFIF_LOCK(bp); 1280 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1281 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1282 continue; 1283 BPFD_LOCK(d); 1284 ++d->bd_rcount; 1285 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0); 1286 if (slen != 0) 1287 #ifdef MAC 1288 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1289 #endif 1290 catchpacket(d, (u_char *)&mb, pktlen, slen, 1291 bpf_mcopy); 1292 BPFD_UNLOCK(d); 1293 } 1294 BPFIF_UNLOCK(bp); 1295 } 1296 1297 /* 1298 * Move the packet data from interface memory (pkt) into the 1299 * store buffer. "cpfn" is the routine called to do the actual data 1300 * transfer. bcopy is passed in to copy contiguous chunks, while 1301 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1302 * pkt is really an mbuf. 1303 */ 1304 static void 1305 catchpacket(d, pkt, pktlen, snaplen, cpfn) 1306 struct bpf_d *d; 1307 u_char *pkt; 1308 u_int pktlen, snaplen; 1309 void (*cpfn)(const void *, void *, size_t); 1310 { 1311 struct bpf_hdr *hp; 1312 int totlen, curlen; 1313 int hdrlen = d->bd_bif->bif_hdrlen; 1314 int do_wakeup = 0; 1315 1316 /* 1317 * Figure out how many bytes to move. If the packet is 1318 * greater or equal to the snapshot length, transfer that 1319 * much. Otherwise, transfer the whole packet (unless 1320 * we hit the buffer size limit). 1321 */ 1322 totlen = hdrlen + min(snaplen, pktlen); 1323 if (totlen > d->bd_bufsize) 1324 totlen = d->bd_bufsize; 1325 1326 /* 1327 * Round up the end of the previous packet to the next longword. 1328 */ 1329 curlen = BPF_WORDALIGN(d->bd_slen); 1330 if (curlen + totlen > d->bd_bufsize) { 1331 /* 1332 * This packet will overflow the storage buffer. 1333 * Rotate the buffers if we can, then wakeup any 1334 * pending reads. 1335 */ 1336 if (d->bd_fbuf == NULL) { 1337 /* 1338 * We haven't completed the previous read yet, 1339 * so drop the packet. 1340 */ 1341 ++d->bd_dcount; 1342 return; 1343 } 1344 ROTATE_BUFFERS(d); 1345 do_wakeup = 1; 1346 curlen = 0; 1347 } 1348 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1349 /* 1350 * Immediate mode is set, or the read timeout has 1351 * already expired during a select call. A packet 1352 * arrived, so the reader should be woken up. 1353 */ 1354 do_wakeup = 1; 1355 1356 /* 1357 * Append the bpf header. 1358 */ 1359 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1360 microtime(&hp->bh_tstamp); 1361 hp->bh_datalen = pktlen; 1362 hp->bh_hdrlen = hdrlen; 1363 /* 1364 * Copy the packet data into the store buffer and update its length. 1365 */ 1366 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1367 d->bd_slen = curlen + totlen; 1368 1369 if (do_wakeup) 1370 bpf_wakeup(d); 1371 } 1372 1373 /* 1374 * Initialize all nonzero fields of a descriptor. 1375 */ 1376 static int 1377 bpf_allocbufs(d) 1378 struct bpf_d *d; 1379 { 1380 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1381 if (d->bd_fbuf == NULL) 1382 return (ENOBUFS); 1383 1384 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1385 if (d->bd_sbuf == NULL) { 1386 free(d->bd_fbuf, M_BPF); 1387 return (ENOBUFS); 1388 } 1389 d->bd_slen = 0; 1390 d->bd_hlen = 0; 1391 return (0); 1392 } 1393 1394 /* 1395 * Free buffers currently in use by a descriptor. 1396 * Called on close. 1397 */ 1398 static void 1399 bpf_freed(d) 1400 struct bpf_d *d; 1401 { 1402 /* 1403 * We don't need to lock out interrupts since this descriptor has 1404 * been detached from its interface and it yet hasn't been marked 1405 * free. 1406 */ 1407 if (d->bd_sbuf != NULL) { 1408 free(d->bd_sbuf, M_BPF); 1409 if (d->bd_hbuf != NULL) 1410 free(d->bd_hbuf, M_BPF); 1411 if (d->bd_fbuf != NULL) 1412 free(d->bd_fbuf, M_BPF); 1413 } 1414 if (d->bd_filter) 1415 free((caddr_t)d->bd_filter, M_BPF); 1416 mtx_destroy(&d->bd_mtx); 1417 } 1418 1419 /* 1420 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1421 * fixed size of the link header (variable length headers not yet supported). 1422 */ 1423 void 1424 bpfattach(ifp, dlt, hdrlen) 1425 struct ifnet *ifp; 1426 u_int dlt, hdrlen; 1427 { 1428 1429 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1430 } 1431 1432 /* 1433 * Attach an interface to bpf. ifp is a pointer to the structure 1434 * defining the interface to be attached, dlt is the link layer type, 1435 * and hdrlen is the fixed size of the link header (variable length 1436 * headers are not yet supporrted). 1437 */ 1438 void 1439 bpfattach2(ifp, dlt, hdrlen, driverp) 1440 struct ifnet *ifp; 1441 u_int dlt, hdrlen; 1442 struct bpf_if **driverp; 1443 { 1444 struct bpf_if *bp; 1445 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1446 if (bp == NULL) 1447 panic("bpfattach"); 1448 1449 LIST_INIT(&bp->bif_dlist); 1450 bp->bif_driverp = driverp; 1451 bp->bif_ifp = ifp; 1452 bp->bif_dlt = dlt; 1453 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1454 1455 mtx_lock(&bpf_mtx); 1456 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1457 mtx_unlock(&bpf_mtx); 1458 1459 *bp->bif_driverp = NULL; 1460 1461 /* 1462 * Compute the length of the bpf header. This is not necessarily 1463 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1464 * that the network layer header begins on a longword boundary (for 1465 * performance reasons and to alleviate alignment restrictions). 1466 */ 1467 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1468 1469 if (bootverbose) 1470 if_printf(ifp, "bpf attached\n"); 1471 } 1472 1473 /* 1474 * Detach bpf from an interface. This involves detaching each descriptor 1475 * associated with the interface, and leaving bd_bif NULL. Notify each 1476 * descriptor as it's detached so that any sleepers wake up and get 1477 * ENXIO. 1478 */ 1479 void 1480 bpfdetach(ifp) 1481 struct ifnet *ifp; 1482 { 1483 struct bpf_if *bp; 1484 struct bpf_d *d; 1485 1486 /* Locate BPF interface information */ 1487 mtx_lock(&bpf_mtx); 1488 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1489 if (ifp == bp->bif_ifp) 1490 break; 1491 } 1492 1493 /* Interface wasn't attached */ 1494 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1495 mtx_unlock(&bpf_mtx); 1496 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1497 return; 1498 } 1499 1500 LIST_REMOVE(bp, bif_next); 1501 mtx_unlock(&bpf_mtx); 1502 1503 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1504 bpf_detachd(d); 1505 BPFD_LOCK(d); 1506 bpf_wakeup(d); 1507 BPFD_UNLOCK(d); 1508 } 1509 1510 mtx_destroy(&bp->bif_mtx); 1511 free(bp, M_BPF); 1512 } 1513 1514 /* 1515 * Get a list of available data link type of the interface. 1516 */ 1517 static int 1518 bpf_getdltlist(d, bfl) 1519 struct bpf_d *d; 1520 struct bpf_dltlist *bfl; 1521 { 1522 int n, error; 1523 struct ifnet *ifp; 1524 struct bpf_if *bp; 1525 1526 ifp = d->bd_bif->bif_ifp; 1527 n = 0; 1528 error = 0; 1529 mtx_lock(&bpf_mtx); 1530 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1531 if (bp->bif_ifp != ifp) 1532 continue; 1533 if (bfl->bfl_list != NULL) { 1534 if (n >= bfl->bfl_len) { 1535 mtx_unlock(&bpf_mtx); 1536 return (ENOMEM); 1537 } 1538 error = copyout(&bp->bif_dlt, 1539 bfl->bfl_list + n, sizeof(u_int)); 1540 } 1541 n++; 1542 } 1543 mtx_unlock(&bpf_mtx); 1544 bfl->bfl_len = n; 1545 return (error); 1546 } 1547 1548 /* 1549 * Set the data link type of a BPF instance. 1550 */ 1551 static int 1552 bpf_setdlt(d, dlt) 1553 struct bpf_d *d; 1554 u_int dlt; 1555 { 1556 int error, opromisc; 1557 struct ifnet *ifp; 1558 struct bpf_if *bp; 1559 1560 if (d->bd_bif->bif_dlt == dlt) 1561 return (0); 1562 ifp = d->bd_bif->bif_ifp; 1563 mtx_lock(&bpf_mtx); 1564 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1565 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1566 break; 1567 } 1568 mtx_unlock(&bpf_mtx); 1569 if (bp != NULL) { 1570 opromisc = d->bd_promisc; 1571 bpf_detachd(d); 1572 bpf_attachd(d, bp); 1573 BPFD_LOCK(d); 1574 reset_d(d); 1575 BPFD_UNLOCK(d); 1576 if (opromisc) { 1577 error = ifpromisc(bp->bif_ifp, 1); 1578 if (error) 1579 if_printf(bp->bif_ifp, 1580 "bpf_setdlt: ifpromisc failed (%d)\n", 1581 error); 1582 else 1583 d->bd_promisc = 1; 1584 } 1585 } 1586 return (bp == NULL ? EINVAL : 0); 1587 } 1588 1589 static void bpf_drvinit(void *unused); 1590 1591 static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev); 1592 1593 static void 1594 bpf_clone(arg, name, namelen, dev) 1595 void *arg; 1596 char *name; 1597 int namelen; 1598 struct cdev **dev; 1599 { 1600 int u; 1601 1602 if (*dev != NULL) 1603 return; 1604 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1605 return; 1606 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1607 "bpf%d", u); 1608 dev_ref(*dev); 1609 (*dev)->si_flags |= SI_CHEAPCLONE; 1610 return; 1611 } 1612 1613 static void 1614 bpf_drvinit(unused) 1615 void *unused; 1616 { 1617 1618 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1619 LIST_INIT(&bpf_iflist); 1620 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1621 } 1622 1623 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1624 1625 #else /* !DEV_BPF && !NETGRAPH_BPF */ 1626 /* 1627 * NOP stubs to allow bpf-using drivers to load and function. 1628 * 1629 * A 'better' implementation would allow the core bpf functionality 1630 * to be loaded at runtime. 1631 */ 1632 1633 void 1634 bpf_tap(bp, pkt, pktlen) 1635 struct bpf_if *bp; 1636 u_char *pkt; 1637 u_int pktlen; 1638 { 1639 } 1640 1641 void 1642 bpf_mtap(bp, m) 1643 struct bpf_if *bp; 1644 struct mbuf *m; 1645 { 1646 } 1647 1648 void 1649 bpf_mtap2(bp, d, l, m) 1650 struct bpf_if *bp; 1651 void *d; 1652 u_int l; 1653 struct mbuf *m; 1654 { 1655 } 1656 1657 void 1658 bpfattach(ifp, dlt, hdrlen) 1659 struct ifnet *ifp; 1660 u_int dlt, hdrlen; 1661 { 1662 } 1663 1664 void 1665 bpfattach2(ifp, dlt, hdrlen, driverp) 1666 struct ifnet *ifp; 1667 u_int dlt, hdrlen; 1668 struct bpf_if **driverp; 1669 { 1670 } 1671 1672 void 1673 bpfdetach(ifp) 1674 struct ifnet *ifp; 1675 { 1676 } 1677 1678 u_int 1679 bpf_filter(pc, p, wirelen, buflen) 1680 const struct bpf_insn *pc; 1681 u_char *p; 1682 u_int wirelen; 1683 u_int buflen; 1684 { 1685 return -1; /* "no filter" behaviour */ 1686 } 1687 1688 int 1689 bpf_validate(f, len) 1690 const struct bpf_insn *f; 1691 int len; 1692 { 1693 return 0; /* false */ 1694 } 1695 1696 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 1697