bpf.c revision 133148
1/* 2 * Copyright (c) 1990, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from the Stanford/CMU enet packet filter, 6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 8 * Berkeley Laboratory. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 35 * 36 * $FreeBSD: head/sys/net/bpf.c 133148 2004-08-05 02:37:36Z rwatson $ 37 */ 38 39#include "opt_bpf.h" 40#include "opt_mac.h" 41#include "opt_netgraph.h" 42 43#include <sys/types.h> 44#include <sys/param.h> 45#include <sys/systm.h> 46#include <sys/conf.h> 47#include <sys/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 75static MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 76 77#if defined(DEV_BPF) || defined(NETGRAPH_BPF) 78 79#define PRINET 26 /* interruptible */ 80 81/* 82 * The default read buffer size is patchable. 83 */ 84static int bpf_bufsize = 4096; 85SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 86 &bpf_bufsize, 0, ""); 87static int bpf_maxbufsize = BPF_MAXBUFSIZE; 88SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 89 &bpf_maxbufsize, 0, ""); 90 91/* 92 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 93 */ 94static struct bpf_if *bpf_iflist; 95static struct mtx bpf_mtx; /* bpf global lock */ 96 97static int bpf_allocbufs(struct bpf_d *); 98static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 99static void bpf_detachd(struct bpf_d *d); 100static void bpf_freed(struct bpf_d *); 101static void bpf_mcopy(const void *, void *, size_t); 102static int bpf_movein(struct uio *, int, 103 struct mbuf **, struct sockaddr *, int *); 104static int bpf_setif(struct bpf_d *, struct ifreq *); 105static void bpf_timed_out(void *); 106static __inline void 107 bpf_wakeup(struct bpf_d *); 108static void catchpacket(struct bpf_d *, u_char *, u_int, 109 u_int, void (*)(const void *, void *, size_t)); 110static void reset_d(struct bpf_d *); 111static int bpf_setf(struct bpf_d *, struct bpf_program *); 112static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 113static int bpf_setdlt(struct bpf_d *, u_int); 114static void filt_bpfdetach(struct knote *); 115static int filt_bpfread(struct knote *, long); 116 117static d_open_t bpfopen; 118static d_close_t bpfclose; 119static d_read_t bpfread; 120static d_write_t bpfwrite; 121static d_ioctl_t bpfioctl; 122static d_poll_t bpfpoll; 123static d_kqfilter_t bpfkqfilter; 124 125static 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 138static struct filterops bpfread_filtops = 139 { 1, NULL, filt_bpfdetach, filt_bpfread }; 140 141static int 142bpf_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); 239bad: 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 */ 247static void 248bpf_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 */ 269static void 270bpf_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 = NULL; 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 == NULL) 304 panic("bpf_detachd: descriptor not in list"); 305 } 306 *p = (*p)->bd_next; 307 if (bp->bif_dlist == NULL) 308 /* 309 * Let the driver know that there are no more listeners. 310 */ 311 *bp->bif_driverp = NULL; 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 */ 320static int 321bpfopen(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 */ 365static int 366bpfclose(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 */ 409static int 410bpfread(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 == NULL) { 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 = NULL; 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 */ 515static __inline void 516bpf_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 531static void 532bpf_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 546static int 547bpfwrite(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 == NULL) 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, NULL); 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 */ 596static void 597reset_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 = NULL; 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 */ 634static int 635bpfioctl(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 == NULL) 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 != NULL) 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 == NULL) { 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 == NULL) 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 == NULL) 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 == NULL) 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 == NULL) 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 */ 931static int 932bpf_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 == NULL) { 941 if (fp->bf_len != 0) 942 return (EINVAL); 943 BPFD_LOCK(d); 944 d->bd_filter = NULL; 945 reset_d(d); 946 BPFD_UNLOCK(d); 947 if (old != NULL) 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 != NULL) 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 */ 977static int 978bpf_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 == NULL) 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 != NULL; bp = bp->bif_next) { 995 struct ifnet *ifp = bp->bif_ifp; 996 997 if (ifp == NULL || 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 == NULL) { 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 */ 1044static int 1045bpfpoll(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 */ 1080int 1081bpfkqfilter(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 1099static void 1100filt_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 1110static int 1111filt_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 */ 1141void 1142bpf_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 /* 1151 * Lockless read to avoid cost of locking the interface if there are 1152 * no descriptors attached. 1153 */ 1154 if (bp->bif_dlist == NULL) 1155 return; 1156 1157 BPFIF_LOCK(bp); 1158 for (d = bp->bif_dlist; d != NULL; d = d->bd_next) { 1159 BPFD_LOCK(d); 1160 ++d->bd_rcount; 1161 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1162 if (slen != 0) { 1163#ifdef MAC 1164 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1165#endif 1166 catchpacket(d, pkt, pktlen, slen, bcopy); 1167 } 1168 BPFD_UNLOCK(d); 1169 } 1170 BPFIF_UNLOCK(bp); 1171} 1172 1173/* 1174 * Copy data from an mbuf chain into a buffer. This code is derived 1175 * from m_copydata in sys/uipc_mbuf.c. 1176 */ 1177static void 1178bpf_mcopy(src_arg, dst_arg, len) 1179 const void *src_arg; 1180 void *dst_arg; 1181 size_t len; 1182{ 1183 const struct mbuf *m; 1184 u_int count; 1185 u_char *dst; 1186 1187 m = src_arg; 1188 dst = dst_arg; 1189 while (len > 0) { 1190 if (m == NULL) 1191 panic("bpf_mcopy"); 1192 count = min(m->m_len, len); 1193 bcopy(mtod(m, void *), dst, count); 1194 m = m->m_next; 1195 dst += count; 1196 len -= count; 1197 } 1198} 1199 1200/* 1201 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1202 */ 1203void 1204bpf_mtap(bp, m) 1205 struct bpf_if *bp; 1206 struct mbuf *m; 1207{ 1208 struct bpf_d *d; 1209 u_int pktlen, slen; 1210 1211 /* 1212 * Lockless read to avoid cost of locking the interface if there are 1213 * no descriptors attached. 1214 */ 1215 if (bp->bif_dlist == NULL) 1216 return; 1217 1218 pktlen = m_length(m, NULL); 1219 if (pktlen == m->m_len) { 1220 bpf_tap(bp, mtod(m, u_char *), pktlen); 1221 return; 1222 } 1223 1224 BPFIF_LOCK(bp); 1225 for (d = bp->bif_dlist; d != NULL; d = d->bd_next) { 1226 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1227 continue; 1228 BPFD_LOCK(d); 1229 ++d->bd_rcount; 1230 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1231 if (slen != 0) 1232#ifdef MAC 1233 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1234#endif 1235 catchpacket(d, (u_char *)m, pktlen, slen, 1236 bpf_mcopy); 1237 BPFD_UNLOCK(d); 1238 } 1239 BPFIF_UNLOCK(bp); 1240} 1241 1242/* 1243 * Incoming linkage from device drivers, when packet is in 1244 * an mbuf chain and to be prepended by a contiguous header. 1245 */ 1246void 1247bpf_mtap2(bp, data, dlen, m) 1248 struct bpf_if *bp; 1249 void *data; 1250 u_int dlen; 1251 struct mbuf *m; 1252{ 1253 struct mbuf mb; 1254 struct bpf_d *d; 1255 u_int pktlen, slen; 1256 1257 /* 1258 * Lockless read to avoid cost of locking the interface if there are 1259 * no descriptors attached. 1260 */ 1261 if (bp->bif_dlist == NULL) 1262 return; 1263 1264 pktlen = m_length(m, NULL); 1265 /* 1266 * Craft on-stack mbuf suitable for passing to bpf_filter. 1267 * Note that we cut corners here; we only setup what's 1268 * absolutely needed--this mbuf should never go anywhere else. 1269 */ 1270 mb.m_next = m; 1271 mb.m_data = data; 1272 mb.m_len = dlen; 1273 pktlen += dlen; 1274 1275 BPFIF_LOCK(bp); 1276 for (d = bp->bif_dlist; d != NULL; d = d->bd_next) { 1277 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1278 continue; 1279 BPFD_LOCK(d); 1280 ++d->bd_rcount; 1281 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0); 1282 if (slen != 0) 1283#ifdef MAC 1284 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1285#endif 1286 catchpacket(d, (u_char *)&mb, pktlen, slen, 1287 bpf_mcopy); 1288 BPFD_UNLOCK(d); 1289 } 1290 BPFIF_UNLOCK(bp); 1291} 1292 1293/* 1294 * Move the packet data from interface memory (pkt) into the 1295 * store buffer. "cpfn" is the routine called to do the actual data 1296 * transfer. bcopy is passed in to copy contiguous chunks, while 1297 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1298 * pkt is really an mbuf. 1299 */ 1300static void 1301catchpacket(d, pkt, pktlen, snaplen, cpfn) 1302 struct bpf_d *d; 1303 u_char *pkt; 1304 u_int pktlen, snaplen; 1305 void (*cpfn)(const void *, void *, size_t); 1306{ 1307 struct bpf_hdr *hp; 1308 int totlen, curlen; 1309 int hdrlen = d->bd_bif->bif_hdrlen; 1310 1311 /* 1312 * Figure out how many bytes to move. If the packet is 1313 * greater or equal to the snapshot length, transfer that 1314 * much. Otherwise, transfer the whole packet (unless 1315 * we hit the buffer size limit). 1316 */ 1317 totlen = hdrlen + min(snaplen, pktlen); 1318 if (totlen > d->bd_bufsize) 1319 totlen = d->bd_bufsize; 1320 1321 /* 1322 * Round up the end of the previous packet to the next longword. 1323 */ 1324 curlen = BPF_WORDALIGN(d->bd_slen); 1325 if (curlen + totlen > d->bd_bufsize) { 1326 /* 1327 * This packet will overflow the storage buffer. 1328 * Rotate the buffers if we can, then wakeup any 1329 * pending reads. 1330 */ 1331 if (d->bd_fbuf == NULL) { 1332 /* 1333 * We haven't completed the previous read yet, 1334 * so drop the packet. 1335 */ 1336 ++d->bd_dcount; 1337 return; 1338 } 1339 ROTATE_BUFFERS(d); 1340 bpf_wakeup(d); 1341 curlen = 0; 1342 } 1343 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1344 /* 1345 * Immediate mode is set, or the read timeout has 1346 * already expired during a select call. A packet 1347 * arrived, so the reader should be woken up. 1348 */ 1349 bpf_wakeup(d); 1350 1351 /* 1352 * Append the bpf header. 1353 */ 1354 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1355 microtime(&hp->bh_tstamp); 1356 hp->bh_datalen = pktlen; 1357 hp->bh_hdrlen = hdrlen; 1358 /* 1359 * Copy the packet data into the store buffer and update its length. 1360 */ 1361 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1362 d->bd_slen = curlen + totlen; 1363} 1364 1365/* 1366 * Initialize all nonzero fields of a descriptor. 1367 */ 1368static int 1369bpf_allocbufs(d) 1370 struct bpf_d *d; 1371{ 1372 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1373 if (d->bd_fbuf == NULL) 1374 return (ENOBUFS); 1375 1376 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1377 if (d->bd_sbuf == NULL) { 1378 free(d->bd_fbuf, M_BPF); 1379 return (ENOBUFS); 1380 } 1381 d->bd_slen = 0; 1382 d->bd_hlen = 0; 1383 return (0); 1384} 1385 1386/* 1387 * Free buffers currently in use by a descriptor. 1388 * Called on close. 1389 */ 1390static void 1391bpf_freed(d) 1392 struct bpf_d *d; 1393{ 1394 /* 1395 * We don't need to lock out interrupts since this descriptor has 1396 * been detached from its interface and it yet hasn't been marked 1397 * free. 1398 */ 1399 if (d->bd_sbuf != NULL) { 1400 free(d->bd_sbuf, M_BPF); 1401 if (d->bd_hbuf != NULL) 1402 free(d->bd_hbuf, M_BPF); 1403 if (d->bd_fbuf != NULL) 1404 free(d->bd_fbuf, M_BPF); 1405 } 1406 if (d->bd_filter) 1407 free((caddr_t)d->bd_filter, M_BPF); 1408 mtx_destroy(&d->bd_mtx); 1409} 1410 1411/* 1412 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1413 * fixed size of the link header (variable length headers not yet supported). 1414 */ 1415void 1416bpfattach(ifp, dlt, hdrlen) 1417 struct ifnet *ifp; 1418 u_int dlt, hdrlen; 1419{ 1420 1421 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1422} 1423 1424/* 1425 * Attach an interface to bpf. ifp is a pointer to the structure 1426 * defining the interface to be attached, dlt is the link layer type, 1427 * and hdrlen is the fixed size of the link header (variable length 1428 * headers are not yet supporrted). 1429 */ 1430void 1431bpfattach2(ifp, dlt, hdrlen, driverp) 1432 struct ifnet *ifp; 1433 u_int dlt, hdrlen; 1434 struct bpf_if **driverp; 1435{ 1436 struct bpf_if *bp; 1437 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1438 if (bp == NULL) 1439 panic("bpfattach"); 1440 1441 bp->bif_dlist = NULL; 1442 bp->bif_driverp = driverp; 1443 bp->bif_ifp = ifp; 1444 bp->bif_dlt = dlt; 1445 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1446 1447 mtx_lock(&bpf_mtx); 1448 bp->bif_next = bpf_iflist; 1449 bpf_iflist = bp; 1450 mtx_unlock(&bpf_mtx); 1451 1452 *bp->bif_driverp = NULL; 1453 1454 /* 1455 * Compute the length of the bpf header. This is not necessarily 1456 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1457 * that the network layer header begins on a longword boundary (for 1458 * performance reasons and to alleviate alignment restrictions). 1459 */ 1460 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1461 1462 if (bootverbose) 1463 if_printf(ifp, "bpf attached\n"); 1464} 1465 1466/* 1467 * Detach bpf from an interface. This involves detaching each descriptor 1468 * associated with the interface, and leaving bd_bif NULL. Notify each 1469 * descriptor as it's detached so that any sleepers wake up and get 1470 * ENXIO. 1471 */ 1472void 1473bpfdetach(ifp) 1474 struct ifnet *ifp; 1475{ 1476 struct bpf_if *bp, *bp_prev; 1477 struct bpf_d *d; 1478 1479 /* Locate BPF interface information */ 1480 bp_prev = NULL; 1481 1482 mtx_lock(&bpf_mtx); 1483 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1484 if (ifp == bp->bif_ifp) 1485 break; 1486 bp_prev = bp; 1487 } 1488 1489 /* Interface wasn't attached */ 1490 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1491 mtx_unlock(&bpf_mtx); 1492 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1493 return; 1494 } 1495 1496 if (bp_prev) { 1497 bp_prev->bif_next = bp->bif_next; 1498 } else { 1499 bpf_iflist = bp->bif_next; 1500 } 1501 mtx_unlock(&bpf_mtx); 1502 1503 while ((d = 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 */ 1517static int 1518bpf_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 for (bp = bpf_iflist; bp != NULL; bp = bp->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 */ 1551static int 1552bpf_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 for (bp = bpf_iflist; bp != NULL; bp = bp->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 BPFD_LOCK(d); 1571 opromisc = d->bd_promisc; 1572 bpf_detachd(d); 1573 bpf_attachd(d, bp); 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 1589static void bpf_drvinit(void *unused); 1590 1591static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev); 1592 1593static void 1594bpf_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)->si_flags |= SI_CHEAPCLONE; 1609 return; 1610} 1611 1612static void 1613bpf_drvinit(unused) 1614 void *unused; 1615{ 1616 1617 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1618 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1619} 1620 1621SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1622 1623#else /* !DEV_BPF && !NETGRAPH_BPF */ 1624/* 1625 * NOP stubs to allow bpf-using drivers to load and function. 1626 * 1627 * A 'better' implementation would allow the core bpf functionality 1628 * to be loaded at runtime. 1629 */ 1630 1631void 1632bpf_tap(bp, pkt, pktlen) 1633 struct bpf_if *bp; 1634 u_char *pkt; 1635 u_int pktlen; 1636{ 1637} 1638 1639void 1640bpf_mtap(bp, m) 1641 struct bpf_if *bp; 1642 struct mbuf *m; 1643{ 1644} 1645 1646void 1647bpf_mtap2(bp, d, l, m) 1648 struct bpf_if *bp; 1649 void *d; 1650 u_int l; 1651 struct mbuf *m; 1652{ 1653} 1654 1655void 1656bpfattach(ifp, dlt, hdrlen) 1657 struct ifnet *ifp; 1658 u_int dlt, hdrlen; 1659{ 1660} 1661 1662void 1663bpfattach2(ifp, dlt, hdrlen, driverp) 1664 struct ifnet *ifp; 1665 u_int dlt, hdrlen; 1666 struct bpf_if **driverp; 1667{ 1668} 1669 1670void 1671bpfdetach(ifp) 1672 struct ifnet *ifp; 1673{ 1674} 1675 1676u_int 1677bpf_filter(pc, p, wirelen, buflen) 1678 const struct bpf_insn *pc; 1679 u_char *p; 1680 u_int wirelen; 1681 u_int buflen; 1682{ 1683 return -1; /* "no filter" behaviour */ 1684} 1685 1686int 1687bpf_validate(f, len) 1688 const struct bpf_insn *f; 1689 int len; 1690{ 1691 return 0; /* false */ 1692} 1693 1694#endif /* !DEV_BPF && !NETGRAPH_BPF */ 1695