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/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 struct bpf_if *bpf_iflist; 95 static struct mtx bpf_mtx; /* bpf global lock */ 96 97 static int bpf_allocbufs(struct bpf_d *); 98 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 99 static void bpf_detachd(struct bpf_d *d); 100 static void bpf_freed(struct bpf_d *); 101 static void bpf_mcopy(const void *, void *, size_t); 102 static int bpf_movein(struct uio *, int, 103 struct mbuf **, struct sockaddr *, int *); 104 static int bpf_setif(struct bpf_d *, struct ifreq *); 105 static void bpf_timed_out(void *); 106 static __inline void 107 bpf_wakeup(struct bpf_d *); 108 static void catchpacket(struct bpf_d *, u_char *, u_int, 109 u_int, void (*)(const void *, void *, size_t)); 110 static void reset_d(struct bpf_d *); 111 static int bpf_setf(struct bpf_d *, struct bpf_program *); 112 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 113 static int bpf_setdlt(struct bpf_d *, u_int); 114 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 d->bd_next = bp->bif_dlist; 260 bp->bif_dlist = d; 261 262 *bp->bif_driverp = bp; 263 BPFIF_UNLOCK(bp); 264 } 265 266 /* 267 * Detach a file from its interface. 268 */ 269 static void 270 bpf_detachd(d) 271 struct bpf_d *d; 272 { 273 int error; 274 struct bpf_d **p; 275 struct bpf_if *bp; 276 277 /* XXX locking */ 278 bp = d->bd_bif; 279 d->bd_bif = 0; 280 /* 281 * Check if this descriptor had requested promiscuous mode. 282 * If so, turn it off. 283 */ 284 if (d->bd_promisc) { 285 d->bd_promisc = 0; 286 error = ifpromisc(bp->bif_ifp, 0); 287 if (error != 0 && error != ENXIO) { 288 /* 289 * ENXIO can happen if a pccard is unplugged 290 * Something is really wrong if we were able to put 291 * the driver into promiscuous mode, but can't 292 * take it out. 293 */ 294 if_printf(bp->bif_ifp, 295 "bpf_detach: ifpromisc failed (%d)\n", error); 296 } 297 } 298 /* Remove d from the interface's descriptor list. */ 299 BPFIF_LOCK(bp); 300 p = &bp->bif_dlist; 301 while (*p != d) { 302 p = &(*p)->bd_next; 303 if (*p == 0) 304 panic("bpf_detachd: descriptor not in list"); 305 } 306 *p = (*p)->bd_next; 307 if (bp->bif_dlist == 0) 308 /* 309 * Let the driver know that there are no more listeners. 310 */ 311 *bp->bif_driverp = 0; 312 BPFIF_UNLOCK(bp); 313 } 314 315 /* 316 * Open ethernet device. Returns ENXIO for illegal minor device number, 317 * EBUSY if file is open by another process. 318 */ 319 /* ARGSUSED */ 320 static int 321 bpfopen(dev, flags, fmt, td) 322 struct cdev *dev; 323 int flags; 324 int fmt; 325 struct thread *td; 326 { 327 struct bpf_d *d; 328 329 mtx_lock(&bpf_mtx); 330 d = dev->si_drv1; 331 /* 332 * Each minor can be opened by only one process. If the requested 333 * minor is in use, return EBUSY. 334 */ 335 if (d) { 336 mtx_unlock(&bpf_mtx); 337 return (EBUSY); 338 } 339 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 340 mtx_unlock(&bpf_mtx); 341 342 if ((dev->si_flags & SI_NAMED) == 0) 343 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 344 "bpf%d", dev2unit(dev)); 345 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 346 dev->si_drv1 = d; 347 d->bd_bufsize = bpf_bufsize; 348 d->bd_sig = SIGIO; 349 d->bd_seesent = 1; 350 #ifdef MAC 351 mac_init_bpfdesc(d); 352 mac_create_bpfdesc(td->td_ucred, d); 353 #endif 354 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 355 callout_init(&d->bd_callout, debug_mpsafenet ? CALLOUT_MPSAFE : 0); 356 357 return (0); 358 } 359 360 /* 361 * Close the descriptor by detaching it from its interface, 362 * deallocating its buffers, and marking it free. 363 */ 364 /* ARGSUSED */ 365 static int 366 bpfclose(dev, flags, fmt, td) 367 struct cdev *dev; 368 int flags; 369 int fmt; 370 struct thread *td; 371 { 372 struct bpf_d *d = dev->si_drv1; 373 374 BPFD_LOCK(d); 375 if (d->bd_state == BPF_WAITING) 376 callout_stop(&d->bd_callout); 377 d->bd_state = BPF_IDLE; 378 BPFD_UNLOCK(d); 379 funsetown(&d->bd_sigio); 380 mtx_lock(&bpf_mtx); 381 if (d->bd_bif) 382 bpf_detachd(d); 383 mtx_unlock(&bpf_mtx); 384 #ifdef MAC 385 mac_destroy_bpfdesc(d); 386 #endif /* MAC */ 387 bpf_freed(d); 388 dev->si_drv1 = 0; 389 free(d, M_BPF); 390 391 return (0); 392 } 393 394 395 /* 396 * Rotate the packet buffers in descriptor d. Move the store buffer 397 * into the hold slot, and the free buffer into the store slot. 398 * Zero the length of the new store buffer. 399 */ 400 #define ROTATE_BUFFERS(d) \ 401 (d)->bd_hbuf = (d)->bd_sbuf; \ 402 (d)->bd_hlen = (d)->bd_slen; \ 403 (d)->bd_sbuf = (d)->bd_fbuf; \ 404 (d)->bd_slen = 0; \ 405 (d)->bd_fbuf = 0; 406 /* 407 * bpfread - read next chunk of packets from buffers 408 */ 409 static int 410 bpfread(dev, uio, ioflag) 411 struct cdev *dev; 412 struct uio *uio; 413 int ioflag; 414 { 415 struct bpf_d *d = dev->si_drv1; 416 int timed_out; 417 int error; 418 419 /* 420 * Restrict application to use a buffer the same size as 421 * as kernel buffers. 422 */ 423 if (uio->uio_resid != d->bd_bufsize) 424 return (EINVAL); 425 426 BPFD_LOCK(d); 427 if (d->bd_state == BPF_WAITING) 428 callout_stop(&d->bd_callout); 429 timed_out = (d->bd_state == BPF_TIMED_OUT); 430 d->bd_state = BPF_IDLE; 431 /* 432 * If the hold buffer is empty, then do a timed sleep, which 433 * ends when the timeout expires or when enough packets 434 * have arrived to fill the store buffer. 435 */ 436 while (d->bd_hbuf == 0) { 437 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 438 /* 439 * A packet(s) either arrived since the previous 440 * read or arrived while we were asleep. 441 * Rotate the buffers and return what's here. 442 */ 443 ROTATE_BUFFERS(d); 444 break; 445 } 446 447 /* 448 * No data is available, check to see if the bpf device 449 * is still pointed at a real interface. If not, return 450 * ENXIO so that the userland process knows to rebind 451 * it before using it again. 452 */ 453 if (d->bd_bif == NULL) { 454 BPFD_UNLOCK(d); 455 return (ENXIO); 456 } 457 458 if (ioflag & IO_NDELAY) { 459 BPFD_UNLOCK(d); 460 return (EWOULDBLOCK); 461 } 462 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 463 "bpf", d->bd_rtout); 464 if (error == EINTR || error == ERESTART) { 465 BPFD_UNLOCK(d); 466 return (error); 467 } 468 if (error == EWOULDBLOCK) { 469 /* 470 * On a timeout, return what's in the buffer, 471 * which may be nothing. If there is something 472 * in the store buffer, we can rotate the buffers. 473 */ 474 if (d->bd_hbuf) 475 /* 476 * We filled up the buffer in between 477 * getting the timeout and arriving 478 * here, so we don't need to rotate. 479 */ 480 break; 481 482 if (d->bd_slen == 0) { 483 BPFD_UNLOCK(d); 484 return (0); 485 } 486 ROTATE_BUFFERS(d); 487 break; 488 } 489 } 490 /* 491 * At this point, we know we have something in the hold slot. 492 */ 493 BPFD_UNLOCK(d); 494 495 /* 496 * Move data from hold buffer into user space. 497 * We know the entire buffer is transferred since 498 * we checked above that the read buffer is bpf_bufsize bytes. 499 */ 500 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 501 502 BPFD_LOCK(d); 503 d->bd_fbuf = d->bd_hbuf; 504 d->bd_hbuf = 0; 505 d->bd_hlen = 0; 506 BPFD_UNLOCK(d); 507 508 return (error); 509 } 510 511 512 /* 513 * If there are processes sleeping on this descriptor, wake them up. 514 */ 515 static __inline void 516 bpf_wakeup(d) 517 struct bpf_d *d; 518 { 519 if (d->bd_state == BPF_WAITING) { 520 callout_stop(&d->bd_callout); 521 d->bd_state = BPF_IDLE; 522 } 523 wakeup(d); 524 if (d->bd_async && d->bd_sig && d->bd_sigio) 525 pgsigio(&d->bd_sigio, d->bd_sig, 0); 526 527 selwakeuppri(&d->bd_sel, PRINET); 528 KNOTE(&d->bd_sel.si_note, 0); 529 } 530 531 static void 532 bpf_timed_out(arg) 533 void *arg; 534 { 535 struct bpf_d *d = (struct bpf_d *)arg; 536 537 BPFD_LOCK(d); 538 if (d->bd_state == BPF_WAITING) { 539 d->bd_state = BPF_TIMED_OUT; 540 if (d->bd_slen != 0) 541 bpf_wakeup(d); 542 } 543 BPFD_UNLOCK(d); 544 } 545 546 static int 547 bpfwrite(dev, uio, ioflag) 548 struct cdev *dev; 549 struct uio *uio; 550 int ioflag; 551 { 552 struct bpf_d *d = dev->si_drv1; 553 struct ifnet *ifp; 554 struct mbuf *m; 555 int error; 556 struct sockaddr dst; 557 int datlen; 558 559 if (d->bd_bif == 0) 560 return (ENXIO); 561 562 ifp = d->bd_bif->bif_ifp; 563 564 if (uio->uio_resid == 0) 565 return (0); 566 567 bzero(&dst, sizeof(dst)); 568 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 569 if (error) 570 return (error); 571 572 if (datlen > ifp->if_mtu) 573 return (EMSGSIZE); 574 575 if (d->bd_hdrcmplt) 576 dst.sa_family = pseudo_AF_HDRCMPLT; 577 578 #ifdef MAC 579 BPFD_LOCK(d); 580 mac_create_mbuf_from_bpfdesc(d, m); 581 BPFD_UNLOCK(d); 582 #endif 583 NET_LOCK_GIANT(); 584 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); 585 NET_UNLOCK_GIANT(); 586 /* 587 * The driver frees the mbuf. 588 */ 589 return (error); 590 } 591 592 /* 593 * Reset a descriptor by flushing its packet buffer and clearing the 594 * receive and drop counts. 595 */ 596 static void 597 reset_d(d) 598 struct bpf_d *d; 599 { 600 601 mtx_assert(&d->bd_mtx, MA_OWNED); 602 if (d->bd_hbuf) { 603 /* Free the hold buffer. */ 604 d->bd_fbuf = d->bd_hbuf; 605 d->bd_hbuf = 0; 606 } 607 d->bd_slen = 0; 608 d->bd_hlen = 0; 609 d->bd_rcount = 0; 610 d->bd_dcount = 0; 611 } 612 613 /* 614 * FIONREAD Check for read packet available. 615 * SIOCGIFADDR Get interface address - convenient hook to driver. 616 * BIOCGBLEN Get buffer len [for read()]. 617 * BIOCSETF Set ethernet read filter. 618 * BIOCFLUSH Flush read packet buffer. 619 * BIOCPROMISC Put interface into promiscuous mode. 620 * BIOCGDLT Get link layer type. 621 * BIOCGETIF Get interface name. 622 * BIOCSETIF Set interface. 623 * BIOCSRTIMEOUT Set read timeout. 624 * BIOCGRTIMEOUT Get read timeout. 625 * BIOCGSTATS Get packet stats. 626 * BIOCIMMEDIATE Set immediate mode. 627 * BIOCVERSION Get filter language version. 628 * BIOCGHDRCMPLT Get "header already complete" flag 629 * BIOCSHDRCMPLT Set "header already complete" flag 630 * BIOCGSEESENT Get "see packets sent" flag 631 * BIOCSSEESENT Set "see packets sent" flag 632 */ 633 /* ARGSUSED */ 634 static int 635 bpfioctl(dev, cmd, addr, flags, td) 636 struct cdev *dev; 637 u_long cmd; 638 caddr_t addr; 639 int flags; 640 struct thread *td; 641 { 642 struct bpf_d *d = dev->si_drv1; 643 int error = 0; 644 645 BPFD_LOCK(d); 646 if (d->bd_state == BPF_WAITING) 647 callout_stop(&d->bd_callout); 648 d->bd_state = BPF_IDLE; 649 BPFD_UNLOCK(d); 650 651 switch (cmd) { 652 653 default: 654 error = EINVAL; 655 break; 656 657 /* 658 * Check for read packet available. 659 */ 660 case FIONREAD: 661 { 662 int n; 663 664 BPFD_LOCK(d); 665 n = d->bd_slen; 666 if (d->bd_hbuf) 667 n += d->bd_hlen; 668 BPFD_UNLOCK(d); 669 670 *(int *)addr = n; 671 break; 672 } 673 674 case SIOCGIFADDR: 675 { 676 struct ifnet *ifp; 677 678 if (d->bd_bif == 0) 679 error = EINVAL; 680 else { 681 ifp = d->bd_bif->bif_ifp; 682 error = (*ifp->if_ioctl)(ifp, cmd, addr); 683 } 684 break; 685 } 686 687 /* 688 * Get buffer len [for read()]. 689 */ 690 case BIOCGBLEN: 691 *(u_int *)addr = d->bd_bufsize; 692 break; 693 694 /* 695 * Set buffer length. 696 */ 697 case BIOCSBLEN: 698 if (d->bd_bif != 0) 699 error = EINVAL; 700 else { 701 u_int size = *(u_int *)addr; 702 703 if (size > bpf_maxbufsize) 704 *(u_int *)addr = size = bpf_maxbufsize; 705 else if (size < BPF_MINBUFSIZE) 706 *(u_int *)addr = size = BPF_MINBUFSIZE; 707 d->bd_bufsize = size; 708 } 709 break; 710 711 /* 712 * Set link layer read filter. 713 */ 714 case BIOCSETF: 715 error = bpf_setf(d, (struct bpf_program *)addr); 716 break; 717 718 /* 719 * Flush read packet buffer. 720 */ 721 case BIOCFLUSH: 722 BPFD_LOCK(d); 723 reset_d(d); 724 BPFD_UNLOCK(d); 725 break; 726 727 /* 728 * Put interface into promiscuous mode. 729 */ 730 case BIOCPROMISC: 731 if (d->bd_bif == 0) { 732 /* 733 * No interface attached yet. 734 */ 735 error = EINVAL; 736 break; 737 } 738 if (d->bd_promisc == 0) { 739 mtx_lock(&Giant); 740 error = ifpromisc(d->bd_bif->bif_ifp, 1); 741 mtx_unlock(&Giant); 742 if (error == 0) 743 d->bd_promisc = 1; 744 } 745 break; 746 747 /* 748 * Get current data link type. 749 */ 750 case BIOCGDLT: 751 if (d->bd_bif == 0) 752 error = EINVAL; 753 else 754 *(u_int *)addr = d->bd_bif->bif_dlt; 755 break; 756 757 /* 758 * Get a list of supported data link types. 759 */ 760 case BIOCGDLTLIST: 761 if (d->bd_bif == 0) 762 error = EINVAL; 763 else 764 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 765 break; 766 767 /* 768 * Set data link type. 769 */ 770 case BIOCSDLT: 771 if (d->bd_bif == 0) 772 error = EINVAL; 773 else 774 error = bpf_setdlt(d, *(u_int *)addr); 775 break; 776 777 /* 778 * Get interface name. 779 */ 780 case BIOCGETIF: 781 if (d->bd_bif == 0) 782 error = EINVAL; 783 else { 784 struct ifnet *const ifp = d->bd_bif->bif_ifp; 785 struct ifreq *const ifr = (struct ifreq *)addr; 786 787 strlcpy(ifr->ifr_name, ifp->if_xname, 788 sizeof(ifr->ifr_name)); 789 } 790 break; 791 792 /* 793 * Set interface. 794 */ 795 case BIOCSETIF: 796 error = bpf_setif(d, (struct ifreq *)addr); 797 break; 798 799 /* 800 * Set read timeout. 801 */ 802 case BIOCSRTIMEOUT: 803 { 804 struct timeval *tv = (struct timeval *)addr; 805 806 /* 807 * Subtract 1 tick from tvtohz() since this isn't 808 * a one-shot timer. 809 */ 810 if ((error = itimerfix(tv)) == 0) 811 d->bd_rtout = tvtohz(tv) - 1; 812 break; 813 } 814 815 /* 816 * Get read timeout. 817 */ 818 case BIOCGRTIMEOUT: 819 { 820 struct timeval *tv = (struct timeval *)addr; 821 822 tv->tv_sec = d->bd_rtout / hz; 823 tv->tv_usec = (d->bd_rtout % hz) * tick; 824 break; 825 } 826 827 /* 828 * Get packet stats. 829 */ 830 case BIOCGSTATS: 831 { 832 struct bpf_stat *bs = (struct bpf_stat *)addr; 833 834 bs->bs_recv = d->bd_rcount; 835 bs->bs_drop = d->bd_dcount; 836 break; 837 } 838 839 /* 840 * Set immediate mode. 841 */ 842 case BIOCIMMEDIATE: 843 d->bd_immediate = *(u_int *)addr; 844 break; 845 846 case BIOCVERSION: 847 { 848 struct bpf_version *bv = (struct bpf_version *)addr; 849 850 bv->bv_major = BPF_MAJOR_VERSION; 851 bv->bv_minor = BPF_MINOR_VERSION; 852 break; 853 } 854 855 /* 856 * Get "header already complete" flag 857 */ 858 case BIOCGHDRCMPLT: 859 *(u_int *)addr = d->bd_hdrcmplt; 860 break; 861 862 /* 863 * Set "header already complete" flag 864 */ 865 case BIOCSHDRCMPLT: 866 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 867 break; 868 869 /* 870 * Get "see sent packets" flag 871 */ 872 case BIOCGSEESENT: 873 *(u_int *)addr = d->bd_seesent; 874 break; 875 876 /* 877 * Set "see sent packets" flag 878 */ 879 case BIOCSSEESENT: 880 d->bd_seesent = *(u_int *)addr; 881 break; 882 883 case FIONBIO: /* Non-blocking I/O */ 884 break; 885 886 case FIOASYNC: /* Send signal on receive packets */ 887 d->bd_async = *(int *)addr; 888 break; 889 890 case FIOSETOWN: 891 error = fsetown(*(int *)addr, &d->bd_sigio); 892 break; 893 894 case FIOGETOWN: 895 *(int *)addr = fgetown(&d->bd_sigio); 896 break; 897 898 /* This is deprecated, FIOSETOWN should be used instead. */ 899 case TIOCSPGRP: 900 error = fsetown(-(*(int *)addr), &d->bd_sigio); 901 break; 902 903 /* This is deprecated, FIOGETOWN should be used instead. */ 904 case TIOCGPGRP: 905 *(int *)addr = -fgetown(&d->bd_sigio); 906 break; 907 908 case BIOCSRSIG: /* Set receive signal */ 909 { 910 u_int sig; 911 912 sig = *(u_int *)addr; 913 914 if (sig >= NSIG) 915 error = EINVAL; 916 else 917 d->bd_sig = sig; 918 break; 919 } 920 case BIOCGRSIG: 921 *(u_int *)addr = d->bd_sig; 922 break; 923 } 924 return (error); 925 } 926 927 /* 928 * Set d's packet filter program to fp. If this file already has a filter, 929 * free it and replace it. Returns EINVAL for bogus requests. 930 */ 931 static int 932 bpf_setf(d, fp) 933 struct bpf_d *d; 934 struct bpf_program *fp; 935 { 936 struct bpf_insn *fcode, *old; 937 u_int flen, size; 938 939 old = d->bd_filter; 940 if (fp->bf_insns == 0) { 941 if (fp->bf_len != 0) 942 return (EINVAL); 943 BPFD_LOCK(d); 944 d->bd_filter = 0; 945 reset_d(d); 946 BPFD_UNLOCK(d); 947 if (old != 0) 948 free((caddr_t)old, M_BPF); 949 return (0); 950 } 951 flen = fp->bf_len; 952 if (flen > BPF_MAXINSNS) 953 return (EINVAL); 954 955 size = flen * sizeof(*fp->bf_insns); 956 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 957 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 958 bpf_validate(fcode, (int)flen)) { 959 BPFD_LOCK(d); 960 d->bd_filter = fcode; 961 reset_d(d); 962 BPFD_UNLOCK(d); 963 if (old != 0) 964 free((caddr_t)old, M_BPF); 965 966 return (0); 967 } 968 free((caddr_t)fcode, M_BPF); 969 return (EINVAL); 970 } 971 972 /* 973 * Detach a file from its current interface (if attached at all) and attach 974 * to the interface indicated by the name stored in ifr. 975 * Return an errno or 0. 976 */ 977 static int 978 bpf_setif(d, ifr) 979 struct bpf_d *d; 980 struct ifreq *ifr; 981 { 982 struct bpf_if *bp; 983 int error; 984 struct ifnet *theywant; 985 986 theywant = ifunit(ifr->ifr_name); 987 if (theywant == 0) 988 return ENXIO; 989 990 /* 991 * Look through attached interfaces for the named one. 992 */ 993 mtx_lock(&bpf_mtx); 994 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 995 struct ifnet *ifp = bp->bif_ifp; 996 997 if (ifp == 0 || ifp != theywant) 998 continue; 999 /* skip additional entry */ 1000 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 1001 continue; 1002 1003 mtx_unlock(&bpf_mtx); 1004 /* 1005 * We found the requested interface. 1006 * If it's not up, return an error. 1007 * Allocate the packet buffers if we need to. 1008 * If we're already attached to requested interface, 1009 * just flush the buffer. 1010 */ 1011 if ((ifp->if_flags & IFF_UP) == 0) 1012 return (ENETDOWN); 1013 1014 if (d->bd_sbuf == 0) { 1015 error = bpf_allocbufs(d); 1016 if (error != 0) 1017 return (error); 1018 } 1019 if (bp != d->bd_bif) { 1020 if (d->bd_bif) 1021 /* 1022 * Detach if attached to something else. 1023 */ 1024 bpf_detachd(d); 1025 1026 bpf_attachd(d, bp); 1027 } 1028 BPFD_LOCK(d); 1029 reset_d(d); 1030 BPFD_UNLOCK(d); 1031 return (0); 1032 } 1033 mtx_unlock(&bpf_mtx); 1034 /* Not found. */ 1035 return (ENXIO); 1036 } 1037 1038 /* 1039 * Support for select() and poll() system calls 1040 * 1041 * Return true iff the specific operation will not block indefinitely. 1042 * Otherwise, return false but make a note that a selwakeup() must be done. 1043 */ 1044 static int 1045 bpfpoll(dev, events, td) 1046 struct cdev *dev; 1047 int events; 1048 struct thread *td; 1049 { 1050 struct bpf_d *d; 1051 int revents; 1052 1053 d = dev->si_drv1; 1054 if (d->bd_bif == NULL) 1055 return (ENXIO); 1056 1057 revents = events & (POLLOUT | POLLWRNORM); 1058 BPFD_LOCK(d); 1059 if (events & (POLLIN | POLLRDNORM)) { 1060 if (bpf_ready(d)) 1061 revents |= events & (POLLIN | POLLRDNORM); 1062 else { 1063 selrecord(td, &d->bd_sel); 1064 /* Start the read timeout if necessary. */ 1065 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1066 callout_reset(&d->bd_callout, d->bd_rtout, 1067 bpf_timed_out, d); 1068 d->bd_state = BPF_WAITING; 1069 } 1070 } 1071 } 1072 BPFD_UNLOCK(d); 1073 return (revents); 1074 } 1075 1076 /* 1077 * Support for kevent() system call. Register EVFILT_READ filters and 1078 * reject all others. 1079 */ 1080 int 1081 bpfkqfilter(dev, kn) 1082 struct cdev *dev; 1083 struct knote *kn; 1084 { 1085 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1086 1087 if (kn->kn_filter != EVFILT_READ) 1088 return (1); 1089 1090 kn->kn_fop = &bpfread_filtops; 1091 kn->kn_hook = d; 1092 BPFD_LOCK(d); 1093 SLIST_INSERT_HEAD(&d->bd_sel.si_note, kn, kn_selnext); 1094 BPFD_UNLOCK(d); 1095 1096 return (0); 1097 } 1098 1099 static void 1100 filt_bpfdetach(kn) 1101 struct knote *kn; 1102 { 1103 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1104 1105 BPFD_LOCK(d); 1106 SLIST_REMOVE(&d->bd_sel.si_note, kn, knote, kn_selnext); 1107 BPFD_UNLOCK(d); 1108 } 1109 1110 static int 1111 filt_bpfread(kn, hint) 1112 struct knote *kn; 1113 long hint; 1114 { 1115 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1116 int ready; 1117 1118 BPFD_LOCK(d); 1119 ready = bpf_ready(d); 1120 if (ready) { 1121 kn->kn_data = d->bd_slen; 1122 if (d->bd_hbuf) 1123 kn->kn_data += d->bd_hlen; 1124 } 1125 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1126 callout_reset(&d->bd_callout, d->bd_rtout, 1127 bpf_timed_out, d); 1128 d->bd_state = BPF_WAITING; 1129 } 1130 BPFD_UNLOCK(d); 1131 1132 return (ready); 1133 } 1134 1135 /* 1136 * Incoming linkage from device drivers. Process the packet pkt, of length 1137 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1138 * by each process' filter, and if accepted, stashed into the corresponding 1139 * buffer. 1140 */ 1141 void 1142 bpf_tap(bp, pkt, pktlen) 1143 struct bpf_if *bp; 1144 u_char *pkt; 1145 u_int pktlen; 1146 { 1147 struct bpf_d *d; 1148 u_int slen; 1149 1150 BPFIF_LOCK(bp); 1151 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1152 BPFD_LOCK(d); 1153 ++d->bd_rcount; 1154 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1155 if (slen != 0) { 1156 #ifdef MAC 1157 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1158 #endif 1159 catchpacket(d, pkt, pktlen, slen, bcopy); 1160 } 1161 BPFD_UNLOCK(d); 1162 } 1163 BPFIF_UNLOCK(bp); 1164 } 1165 1166 /* 1167 * Copy data from an mbuf chain into a buffer. This code is derived 1168 * from m_copydata in sys/uipc_mbuf.c. 1169 */ 1170 static void 1171 bpf_mcopy(src_arg, dst_arg, len) 1172 const void *src_arg; 1173 void *dst_arg; 1174 size_t len; 1175 { 1176 const struct mbuf *m; 1177 u_int count; 1178 u_char *dst; 1179 1180 m = src_arg; 1181 dst = dst_arg; 1182 while (len > 0) { 1183 if (m == 0) 1184 panic("bpf_mcopy"); 1185 count = min(m->m_len, len); 1186 bcopy(mtod(m, void *), dst, count); 1187 m = m->m_next; 1188 dst += count; 1189 len -= count; 1190 } 1191 } 1192 1193 /* 1194 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1195 */ 1196 void 1197 bpf_mtap(bp, m) 1198 struct bpf_if *bp; 1199 struct mbuf *m; 1200 { 1201 struct bpf_d *d; 1202 u_int pktlen, slen; 1203 1204 pktlen = m_length(m, NULL); 1205 if (pktlen == m->m_len) { 1206 bpf_tap(bp, mtod(m, u_char *), pktlen); 1207 return; 1208 } 1209 1210 BPFIF_LOCK(bp); 1211 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1212 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1213 continue; 1214 BPFD_LOCK(d); 1215 ++d->bd_rcount; 1216 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1217 if (slen != 0) 1218 #ifdef MAC 1219 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1220 #endif 1221 catchpacket(d, (u_char *)m, pktlen, slen, 1222 bpf_mcopy); 1223 BPFD_UNLOCK(d); 1224 } 1225 BPFIF_UNLOCK(bp); 1226 } 1227 1228 /* 1229 * Incoming linkage from device drivers, when packet is in 1230 * an mbuf chain and to be prepended by a contiguous header. 1231 */ 1232 void 1233 bpf_mtap2(bp, data, dlen, m) 1234 struct bpf_if *bp; 1235 void *data; 1236 u_int dlen; 1237 struct mbuf *m; 1238 { 1239 struct mbuf mb; 1240 struct bpf_d *d; 1241 u_int pktlen, slen; 1242 1243 pktlen = m_length(m, NULL); 1244 /* 1245 * Craft on-stack mbuf suitable for passing to bpf_filter. 1246 * Note that we cut corners here; we only setup what's 1247 * absolutely needed--this mbuf should never go anywhere else. 1248 */ 1249 mb.m_next = m; 1250 mb.m_data = data; 1251 mb.m_len = dlen; 1252 pktlen += dlen; 1253 1254 BPFIF_LOCK(bp); 1255 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1256 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1257 continue; 1258 BPFD_LOCK(d); 1259 ++d->bd_rcount; 1260 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0); 1261 if (slen != 0) 1262 #ifdef MAC 1263 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1264 #endif 1265 catchpacket(d, (u_char *)&mb, pktlen, slen, 1266 bpf_mcopy); 1267 BPFD_UNLOCK(d); 1268 } 1269 BPFIF_UNLOCK(bp); 1270 } 1271 1272 /* 1273 * Move the packet data from interface memory (pkt) into the 1274 * store buffer. "cpfn" is the routine called to do the actual data 1275 * transfer. bcopy is passed in to copy contiguous chunks, while 1276 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1277 * pkt is really an mbuf. 1278 */ 1279 static void 1280 catchpacket(d, pkt, pktlen, snaplen, cpfn) 1281 struct bpf_d *d; 1282 u_char *pkt; 1283 u_int pktlen, snaplen; 1284 void (*cpfn)(const void *, void *, size_t); 1285 { 1286 struct bpf_hdr *hp; 1287 int totlen, curlen; 1288 int hdrlen = d->bd_bif->bif_hdrlen; 1289 1290 /* 1291 * Figure out how many bytes to move. If the packet is 1292 * greater or equal to the snapshot length, transfer that 1293 * much. Otherwise, transfer the whole packet (unless 1294 * we hit the buffer size limit). 1295 */ 1296 totlen = hdrlen + min(snaplen, pktlen); 1297 if (totlen > d->bd_bufsize) 1298 totlen = d->bd_bufsize; 1299 1300 /* 1301 * Round up the end of the previous packet to the next longword. 1302 */ 1303 curlen = BPF_WORDALIGN(d->bd_slen); 1304 if (curlen + totlen > d->bd_bufsize) { 1305 /* 1306 * This packet will overflow the storage buffer. 1307 * Rotate the buffers if we can, then wakeup any 1308 * pending reads. 1309 */ 1310 if (d->bd_fbuf == 0) { 1311 /* 1312 * We haven't completed the previous read yet, 1313 * so drop the packet. 1314 */ 1315 ++d->bd_dcount; 1316 return; 1317 } 1318 ROTATE_BUFFERS(d); 1319 bpf_wakeup(d); 1320 curlen = 0; 1321 } 1322 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1323 /* 1324 * Immediate mode is set, or the read timeout has 1325 * already expired during a select call. A packet 1326 * arrived, so the reader should be woken up. 1327 */ 1328 bpf_wakeup(d); 1329 1330 /* 1331 * Append the bpf header. 1332 */ 1333 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1334 microtime(&hp->bh_tstamp); 1335 hp->bh_datalen = pktlen; 1336 hp->bh_hdrlen = hdrlen; 1337 /* 1338 * Copy the packet data into the store buffer and update its length. 1339 */ 1340 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1341 d->bd_slen = curlen + totlen; 1342 } 1343 1344 /* 1345 * Initialize all nonzero fields of a descriptor. 1346 */ 1347 static int 1348 bpf_allocbufs(d) 1349 struct bpf_d *d; 1350 { 1351 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1352 if (d->bd_fbuf == 0) 1353 return (ENOBUFS); 1354 1355 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1356 if (d->bd_sbuf == 0) { 1357 free(d->bd_fbuf, M_BPF); 1358 return (ENOBUFS); 1359 } 1360 d->bd_slen = 0; 1361 d->bd_hlen = 0; 1362 return (0); 1363 } 1364 1365 /* 1366 * Free buffers currently in use by a descriptor. 1367 * Called on close. 1368 */ 1369 static void 1370 bpf_freed(d) 1371 struct bpf_d *d; 1372 { 1373 /* 1374 * We don't need to lock out interrupts since this descriptor has 1375 * been detached from its interface and it yet hasn't been marked 1376 * free. 1377 */ 1378 if (d->bd_sbuf != 0) { 1379 free(d->bd_sbuf, M_BPF); 1380 if (d->bd_hbuf != 0) 1381 free(d->bd_hbuf, M_BPF); 1382 if (d->bd_fbuf != 0) 1383 free(d->bd_fbuf, M_BPF); 1384 } 1385 if (d->bd_filter) 1386 free((caddr_t)d->bd_filter, M_BPF); 1387 mtx_destroy(&d->bd_mtx); 1388 } 1389 1390 /* 1391 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1392 * fixed size of the link header (variable length headers not yet supported). 1393 */ 1394 void 1395 bpfattach(ifp, dlt, hdrlen) 1396 struct ifnet *ifp; 1397 u_int dlt, hdrlen; 1398 { 1399 1400 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1401 } 1402 1403 /* 1404 * Attach an interface to bpf. ifp is a pointer to the structure 1405 * defining the interface to be attached, dlt is the link layer type, 1406 * and hdrlen is the fixed size of the link header (variable length 1407 * headers are not yet supporrted). 1408 */ 1409 void 1410 bpfattach2(ifp, dlt, hdrlen, driverp) 1411 struct ifnet *ifp; 1412 u_int dlt, hdrlen; 1413 struct bpf_if **driverp; 1414 { 1415 struct bpf_if *bp; 1416 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1417 if (bp == 0) 1418 panic("bpfattach"); 1419 1420 bp->bif_dlist = 0; 1421 bp->bif_driverp = driverp; 1422 bp->bif_ifp = ifp; 1423 bp->bif_dlt = dlt; 1424 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1425 1426 mtx_lock(&bpf_mtx); 1427 bp->bif_next = bpf_iflist; 1428 bpf_iflist = bp; 1429 mtx_unlock(&bpf_mtx); 1430 1431 *bp->bif_driverp = 0; 1432 1433 /* 1434 * Compute the length of the bpf header. This is not necessarily 1435 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1436 * that the network layer header begins on a longword boundary (for 1437 * performance reasons and to alleviate alignment restrictions). 1438 */ 1439 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1440 1441 if (bootverbose) 1442 if_printf(ifp, "bpf attached\n"); 1443 } 1444 1445 /* 1446 * Detach bpf from an interface. This involves detaching each descriptor 1447 * associated with the interface, and leaving bd_bif NULL. Notify each 1448 * descriptor as it's detached so that any sleepers wake up and get 1449 * ENXIO. 1450 */ 1451 void 1452 bpfdetach(ifp) 1453 struct ifnet *ifp; 1454 { 1455 struct bpf_if *bp, *bp_prev; 1456 struct bpf_d *d; 1457 1458 /* Locate BPF interface information */ 1459 bp_prev = NULL; 1460 1461 mtx_lock(&bpf_mtx); 1462 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1463 if (ifp == bp->bif_ifp) 1464 break; 1465 bp_prev = bp; 1466 } 1467 1468 /* Interface wasn't attached */ 1469 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1470 mtx_unlock(&bpf_mtx); 1471 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1472 return; 1473 } 1474 1475 if (bp_prev) { 1476 bp_prev->bif_next = bp->bif_next; 1477 } else { 1478 bpf_iflist = bp->bif_next; 1479 } 1480 mtx_unlock(&bpf_mtx); 1481 1482 while ((d = bp->bif_dlist) != NULL) { 1483 bpf_detachd(d); 1484 BPFD_LOCK(d); 1485 bpf_wakeup(d); 1486 BPFD_UNLOCK(d); 1487 } 1488 1489 mtx_destroy(&bp->bif_mtx); 1490 free(bp, M_BPF); 1491 } 1492 1493 /* 1494 * Get a list of available data link type of the interface. 1495 */ 1496 static int 1497 bpf_getdltlist(d, bfl) 1498 struct bpf_d *d; 1499 struct bpf_dltlist *bfl; 1500 { 1501 int n, error; 1502 struct ifnet *ifp; 1503 struct bpf_if *bp; 1504 1505 ifp = d->bd_bif->bif_ifp; 1506 n = 0; 1507 error = 0; 1508 mtx_lock(&bpf_mtx); 1509 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1510 if (bp->bif_ifp != ifp) 1511 continue; 1512 if (bfl->bfl_list != NULL) { 1513 if (n >= bfl->bfl_len) { 1514 mtx_unlock(&bpf_mtx); 1515 return (ENOMEM); 1516 } 1517 error = copyout(&bp->bif_dlt, 1518 bfl->bfl_list + n, sizeof(u_int)); 1519 } 1520 n++; 1521 } 1522 mtx_unlock(&bpf_mtx); 1523 bfl->bfl_len = n; 1524 return (error); 1525 } 1526 1527 /* 1528 * Set the data link type of a BPF instance. 1529 */ 1530 static int 1531 bpf_setdlt(d, dlt) 1532 struct bpf_d *d; 1533 u_int dlt; 1534 { 1535 int error, opromisc; 1536 struct ifnet *ifp; 1537 struct bpf_if *bp; 1538 1539 if (d->bd_bif->bif_dlt == dlt) 1540 return (0); 1541 ifp = d->bd_bif->bif_ifp; 1542 mtx_lock(&bpf_mtx); 1543 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1544 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1545 break; 1546 } 1547 mtx_unlock(&bpf_mtx); 1548 if (bp != NULL) { 1549 BPFD_LOCK(d); 1550 opromisc = d->bd_promisc; 1551 bpf_detachd(d); 1552 bpf_attachd(d, bp); 1553 reset_d(d); 1554 BPFD_UNLOCK(d); 1555 if (opromisc) { 1556 error = ifpromisc(bp->bif_ifp, 1); 1557 if (error) 1558 if_printf(bp->bif_ifp, 1559 "bpf_setdlt: ifpromisc failed (%d)\n", 1560 error); 1561 else 1562 d->bd_promisc = 1; 1563 } 1564 } 1565 return (bp == NULL ? EINVAL : 0); 1566 } 1567 1568 static void bpf_drvinit(void *unused); 1569 1570 static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev); 1571 1572 static void 1573 bpf_clone(arg, name, namelen, dev) 1574 void *arg; 1575 char *name; 1576 int namelen; 1577 struct cdev **dev; 1578 { 1579 int u; 1580 1581 if (*dev != NULL) 1582 return; 1583 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1584 return; 1585 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1586 "bpf%d", u); 1587 (*dev)->si_flags |= SI_CHEAPCLONE; 1588 return; 1589 } 1590 1591 static void 1592 bpf_drvinit(unused) 1593 void *unused; 1594 { 1595 1596 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1597 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1598 } 1599 1600 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1601 1602 #else /* !DEV_BPF && !NETGRAPH_BPF */ 1603 /* 1604 * NOP stubs to allow bpf-using drivers to load and function. 1605 * 1606 * A 'better' implementation would allow the core bpf functionality 1607 * to be loaded at runtime. 1608 */ 1609 1610 void 1611 bpf_tap(bp, pkt, pktlen) 1612 struct bpf_if *bp; 1613 u_char *pkt; 1614 u_int pktlen; 1615 { 1616 } 1617 1618 void 1619 bpf_mtap(bp, m) 1620 struct bpf_if *bp; 1621 struct mbuf *m; 1622 { 1623 } 1624 1625 void 1626 bpf_mtap2(bp, d, l, m) 1627 struct bpf_if *bp; 1628 void *d; 1629 u_int l; 1630 struct mbuf *m; 1631 { 1632 } 1633 1634 void 1635 bpfattach(ifp, dlt, hdrlen) 1636 struct ifnet *ifp; 1637 u_int dlt, hdrlen; 1638 { 1639 } 1640 1641 void 1642 bpfattach2(ifp, dlt, hdrlen, driverp) 1643 struct ifnet *ifp; 1644 u_int dlt, hdrlen; 1645 struct bpf_if **driverp; 1646 { 1647 } 1648 1649 void 1650 bpfdetach(ifp) 1651 struct ifnet *ifp; 1652 { 1653 } 1654 1655 u_int 1656 bpf_filter(pc, p, wirelen, buflen) 1657 const struct bpf_insn *pc; 1658 u_char *p; 1659 u_int wirelen; 1660 u_int buflen; 1661 { 1662 return -1; /* "no filter" behaviour */ 1663 } 1664 1665 int 1666 bpf_validate(f, len) 1667 const struct bpf_insn *f; 1668 int len; 1669 { 1670 return 0; /* false */ 1671 } 1672 1673 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 1674