bpf.c revision 204105
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 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/net/bpf.c 204105 2010-02-20 00:19:21Z jkim $"); 39 40#include "opt_bpf.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/jail.h> 49#include <sys/malloc.h> 50#include <sys/mbuf.h> 51#include <sys/time.h> 52#include <sys/priv.h> 53#include <sys/proc.h> 54#include <sys/signalvar.h> 55#include <sys/filio.h> 56#include <sys/sockio.h> 57#include <sys/ttycom.h> 58#include <sys/uio.h> 59 60#include <sys/event.h> 61#include <sys/file.h> 62#include <sys/poll.h> 63#include <sys/proc.h> 64 65#include <sys/socket.h> 66 67#include <net/if.h> 68#include <net/bpf.h> 69#include <net/bpf_buffer.h> 70#ifdef BPF_JITTER 71#include <net/bpf_jitter.h> 72#endif 73#include <net/bpf_zerocopy.h> 74#include <net/bpfdesc.h> 75#include <net/vnet.h> 76 77#include <netinet/in.h> 78#include <netinet/if_ether.h> 79#include <sys/kernel.h> 80#include <sys/sysctl.h> 81 82#include <net80211/ieee80211_freebsd.h> 83 84#include <security/mac/mac_framework.h> 85 86MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 87 88#if defined(DEV_BPF) || defined(NETGRAPH_BPF) 89 90#define PRINET 26 /* interruptible */ 91 92/* 93 * bpf_iflist is a list of BPF interface structures, each corresponding to a 94 * specific DLT. The same network interface might have several BPF interface 95 * structures registered by different layers in the stack (i.e., 802.11 96 * frames, ethernet frames, etc). 97 */ 98static LIST_HEAD(, bpf_if) bpf_iflist; 99static struct mtx bpf_mtx; /* bpf global lock */ 100static int bpf_bpfd_cnt; 101 102static void bpf_attachd(struct bpf_d *, struct bpf_if *); 103static void bpf_detachd(struct bpf_d *); 104static void bpf_freed(struct bpf_d *); 105static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 106 struct sockaddr *, int *, struct bpf_insn *); 107static int bpf_setif(struct bpf_d *, struct ifreq *); 108static void bpf_timed_out(void *); 109static __inline void 110 bpf_wakeup(struct bpf_d *); 111static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 112 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 113 struct timeval *); 114static void reset_d(struct bpf_d *); 115static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 116static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 117static int bpf_setdlt(struct bpf_d *, u_int); 118static void filt_bpfdetach(struct knote *); 119static int filt_bpfread(struct knote *, long); 120static void bpf_drvinit(void *); 121static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 122 123SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 124int bpf_maxinsns = BPF_MAXINSNS; 125SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 126 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 127static int bpf_zerocopy_enable = 0; 128SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 129 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 130SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 131 bpf_stats_sysctl, "bpf statistics portal"); 132 133static d_open_t bpfopen; 134static d_read_t bpfread; 135static d_write_t bpfwrite; 136static d_ioctl_t bpfioctl; 137static d_poll_t bpfpoll; 138static d_kqfilter_t bpfkqfilter; 139 140static struct cdevsw bpf_cdevsw = { 141 .d_version = D_VERSION, 142 .d_open = bpfopen, 143 .d_read = bpfread, 144 .d_write = bpfwrite, 145 .d_ioctl = bpfioctl, 146 .d_poll = bpfpoll, 147 .d_name = "bpf", 148 .d_kqfilter = bpfkqfilter, 149}; 150 151static struct filterops bpfread_filtops = { 152 .f_isfd = 1, 153 .f_detach = filt_bpfdetach, 154 .f_event = filt_bpfread, 155}; 156 157/* 158 * Wrapper functions for various buffering methods. If the set of buffer 159 * modes expands, we will probably want to introduce a switch data structure 160 * similar to protosw, et. 161 */ 162static void 163bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 164 u_int len) 165{ 166 167 BPFD_LOCK_ASSERT(d); 168 169 switch (d->bd_bufmode) { 170 case BPF_BUFMODE_BUFFER: 171 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 172 173 case BPF_BUFMODE_ZBUF: 174 d->bd_zcopy++; 175 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 176 177 default: 178 panic("bpf_buf_append_bytes"); 179 } 180} 181 182static void 183bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 184 u_int len) 185{ 186 187 BPFD_LOCK_ASSERT(d); 188 189 switch (d->bd_bufmode) { 190 case BPF_BUFMODE_BUFFER: 191 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 192 193 case BPF_BUFMODE_ZBUF: 194 d->bd_zcopy++; 195 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 196 197 default: 198 panic("bpf_buf_append_mbuf"); 199 } 200} 201 202/* 203 * This function gets called when the free buffer is re-assigned. 204 */ 205static void 206bpf_buf_reclaimed(struct bpf_d *d) 207{ 208 209 BPFD_LOCK_ASSERT(d); 210 211 switch (d->bd_bufmode) { 212 case BPF_BUFMODE_BUFFER: 213 return; 214 215 case BPF_BUFMODE_ZBUF: 216 bpf_zerocopy_buf_reclaimed(d); 217 return; 218 219 default: 220 panic("bpf_buf_reclaimed"); 221 } 222} 223 224/* 225 * If the buffer mechanism has a way to decide that a held buffer can be made 226 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 227 * returned if the buffer can be discarded, (0) is returned if it cannot. 228 */ 229static int 230bpf_canfreebuf(struct bpf_d *d) 231{ 232 233 BPFD_LOCK_ASSERT(d); 234 235 switch (d->bd_bufmode) { 236 case BPF_BUFMODE_ZBUF: 237 return (bpf_zerocopy_canfreebuf(d)); 238 } 239 return (0); 240} 241 242/* 243 * Allow the buffer model to indicate that the current store buffer is 244 * immutable, regardless of the appearance of space. Return (1) if the 245 * buffer is writable, and (0) if not. 246 */ 247static int 248bpf_canwritebuf(struct bpf_d *d) 249{ 250 251 BPFD_LOCK_ASSERT(d); 252 253 switch (d->bd_bufmode) { 254 case BPF_BUFMODE_ZBUF: 255 return (bpf_zerocopy_canwritebuf(d)); 256 } 257 return (1); 258} 259 260/* 261 * Notify buffer model that an attempt to write to the store buffer has 262 * resulted in a dropped packet, in which case the buffer may be considered 263 * full. 264 */ 265static void 266bpf_buffull(struct bpf_d *d) 267{ 268 269 BPFD_LOCK_ASSERT(d); 270 271 switch (d->bd_bufmode) { 272 case BPF_BUFMODE_ZBUF: 273 bpf_zerocopy_buffull(d); 274 break; 275 } 276} 277 278/* 279 * Notify the buffer model that a buffer has moved into the hold position. 280 */ 281void 282bpf_bufheld(struct bpf_d *d) 283{ 284 285 BPFD_LOCK_ASSERT(d); 286 287 switch (d->bd_bufmode) { 288 case BPF_BUFMODE_ZBUF: 289 bpf_zerocopy_bufheld(d); 290 break; 291 } 292} 293 294static void 295bpf_free(struct bpf_d *d) 296{ 297 298 switch (d->bd_bufmode) { 299 case BPF_BUFMODE_BUFFER: 300 return (bpf_buffer_free(d)); 301 302 case BPF_BUFMODE_ZBUF: 303 return (bpf_zerocopy_free(d)); 304 305 default: 306 panic("bpf_buf_free"); 307 } 308} 309 310static int 311bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 312{ 313 314 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 315 return (EOPNOTSUPP); 316 return (bpf_buffer_uiomove(d, buf, len, uio)); 317} 318 319static int 320bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 321{ 322 323 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 324 return (EOPNOTSUPP); 325 return (bpf_buffer_ioctl_sblen(d, i)); 326} 327 328static int 329bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 330{ 331 332 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 333 return (EOPNOTSUPP); 334 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 335} 336 337static int 338bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 339{ 340 341 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 342 return (EOPNOTSUPP); 343 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 344} 345 346static int 347bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 348{ 349 350 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 351 return (EOPNOTSUPP); 352 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 353} 354 355/* 356 * General BPF functions. 357 */ 358static int 359bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 360 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) 361{ 362 const struct ieee80211_bpf_params *p; 363 struct ether_header *eh; 364 struct mbuf *m; 365 int error; 366 int len; 367 int hlen; 368 int slen; 369 370 /* 371 * Build a sockaddr based on the data link layer type. 372 * We do this at this level because the ethernet header 373 * is copied directly into the data field of the sockaddr. 374 * In the case of SLIP, there is no header and the packet 375 * is forwarded as is. 376 * Also, we are careful to leave room at the front of the mbuf 377 * for the link level header. 378 */ 379 switch (linktype) { 380 381 case DLT_SLIP: 382 sockp->sa_family = AF_INET; 383 hlen = 0; 384 break; 385 386 case DLT_EN10MB: 387 sockp->sa_family = AF_UNSPEC; 388 /* XXX Would MAXLINKHDR be better? */ 389 hlen = ETHER_HDR_LEN; 390 break; 391 392 case DLT_FDDI: 393 sockp->sa_family = AF_IMPLINK; 394 hlen = 0; 395 break; 396 397 case DLT_RAW: 398 sockp->sa_family = AF_UNSPEC; 399 hlen = 0; 400 break; 401 402 case DLT_NULL: 403 /* 404 * null interface types require a 4 byte pseudo header which 405 * corresponds to the address family of the packet. 406 */ 407 sockp->sa_family = AF_UNSPEC; 408 hlen = 4; 409 break; 410 411 case DLT_ATM_RFC1483: 412 /* 413 * en atm driver requires 4-byte atm pseudo header. 414 * though it isn't standard, vpi:vci needs to be 415 * specified anyway. 416 */ 417 sockp->sa_family = AF_UNSPEC; 418 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 419 break; 420 421 case DLT_PPP: 422 sockp->sa_family = AF_UNSPEC; 423 hlen = 4; /* This should match PPP_HDRLEN */ 424 break; 425 426 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 427 sockp->sa_family = AF_IEEE80211; 428 hlen = 0; 429 break; 430 431 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 432 sockp->sa_family = AF_IEEE80211; 433 sockp->sa_len = 12; /* XXX != 0 */ 434 hlen = sizeof(struct ieee80211_bpf_params); 435 break; 436 437 default: 438 return (EIO); 439 } 440 441 len = uio->uio_resid; 442 443 if (len - hlen > ifp->if_mtu) 444 return (EMSGSIZE); 445 446 if ((unsigned)len > MJUM16BYTES) 447 return (EIO); 448 449 if (len <= MHLEN) 450 MGETHDR(m, M_WAIT, MT_DATA); 451 else if (len <= MCLBYTES) 452 m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR); 453 else 454 m = m_getjcl(M_WAIT, MT_DATA, M_PKTHDR, 455#if (MJUMPAGESIZE > MCLBYTES) 456 len <= MJUMPAGESIZE ? MJUMPAGESIZE : 457#endif 458 (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES)); 459 m->m_pkthdr.len = m->m_len = len; 460 m->m_pkthdr.rcvif = NULL; 461 *mp = m; 462 463 if (m->m_len < hlen) { 464 error = EPERM; 465 goto bad; 466 } 467 468 error = uiomove(mtod(m, u_char *), len, uio); 469 if (error) 470 goto bad; 471 472 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 473 if (slen == 0) { 474 error = EPERM; 475 goto bad; 476 } 477 478 /* Check for multicast destination */ 479 switch (linktype) { 480 case DLT_EN10MB: 481 eh = mtod(m, struct ether_header *); 482 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 483 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 484 ETHER_ADDR_LEN) == 0) 485 m->m_flags |= M_BCAST; 486 else 487 m->m_flags |= M_MCAST; 488 } 489 break; 490 } 491 492 /* 493 * Make room for link header, and copy it to sockaddr 494 */ 495 if (hlen != 0) { 496 if (sockp->sa_family == AF_IEEE80211) { 497 /* 498 * Collect true length from the parameter header 499 * NB: sockp is known to be zero'd so if we do a 500 * short copy unspecified parameters will be 501 * zero. 502 * NB: packet may not be aligned after stripping 503 * bpf params 504 * XXX check ibp_vers 505 */ 506 p = mtod(m, const struct ieee80211_bpf_params *); 507 hlen = p->ibp_len; 508 if (hlen > sizeof(sockp->sa_data)) { 509 error = EINVAL; 510 goto bad; 511 } 512 } 513 bcopy(m->m_data, sockp->sa_data, hlen); 514 } 515 *hdrlen = hlen; 516 517 return (0); 518bad: 519 m_freem(m); 520 return (error); 521} 522 523/* 524 * Attach file to the bpf interface, i.e. make d listen on bp. 525 */ 526static void 527bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 528{ 529 /* 530 * Point d at bp, and add d to the interface's list of listeners. 531 * Finally, point the driver's bpf cookie at the interface so 532 * it will divert packets to bpf. 533 */ 534 BPFIF_LOCK(bp); 535 d->bd_bif = bp; 536 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 537 538 bpf_bpfd_cnt++; 539 BPFIF_UNLOCK(bp); 540 541 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 542} 543 544/* 545 * Detach a file from its interface. 546 */ 547static void 548bpf_detachd(struct bpf_d *d) 549{ 550 int error; 551 struct bpf_if *bp; 552 struct ifnet *ifp; 553 554 bp = d->bd_bif; 555 BPFIF_LOCK(bp); 556 BPFD_LOCK(d); 557 ifp = d->bd_bif->bif_ifp; 558 559 /* 560 * Remove d from the interface's descriptor list. 561 */ 562 LIST_REMOVE(d, bd_next); 563 564 bpf_bpfd_cnt--; 565 d->bd_bif = NULL; 566 BPFD_UNLOCK(d); 567 BPFIF_UNLOCK(bp); 568 569 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 570 571 /* 572 * Check if this descriptor had requested promiscuous mode. 573 * If so, turn it off. 574 */ 575 if (d->bd_promisc) { 576 d->bd_promisc = 0; 577 CURVNET_SET(ifp->if_vnet); 578 error = ifpromisc(ifp, 0); 579 CURVNET_RESTORE(); 580 if (error != 0 && error != ENXIO) { 581 /* 582 * ENXIO can happen if a pccard is unplugged 583 * Something is really wrong if we were able to put 584 * the driver into promiscuous mode, but can't 585 * take it out. 586 */ 587 if_printf(bp->bif_ifp, 588 "bpf_detach: ifpromisc failed (%d)\n", error); 589 } 590 } 591} 592 593/* 594 * Close the descriptor by detaching it from its interface, 595 * deallocating its buffers, and marking it free. 596 */ 597static void 598bpf_dtor(void *data) 599{ 600 struct bpf_d *d = data; 601 602 BPFD_LOCK(d); 603 if (d->bd_state == BPF_WAITING) 604 callout_stop(&d->bd_callout); 605 d->bd_state = BPF_IDLE; 606 BPFD_UNLOCK(d); 607 funsetown(&d->bd_sigio); 608 mtx_lock(&bpf_mtx); 609 if (d->bd_bif) 610 bpf_detachd(d); 611 mtx_unlock(&bpf_mtx); 612 selwakeuppri(&d->bd_sel, PRINET); 613#ifdef MAC 614 mac_bpfdesc_destroy(d); 615#endif /* MAC */ 616 knlist_destroy(&d->bd_sel.si_note); 617 bpf_freed(d); 618 free(d, M_BPF); 619} 620 621/* 622 * Open ethernet device. Returns ENXIO for illegal minor device number, 623 * EBUSY if file is open by another process. 624 */ 625/* ARGSUSED */ 626static int 627bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 628{ 629 struct bpf_d *d; 630 int error; 631 632 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 633 error = devfs_set_cdevpriv(d, bpf_dtor); 634 if (error != 0) { 635 free(d, M_BPF); 636 return (error); 637 } 638 639 /* 640 * For historical reasons, perform a one-time initialization call to 641 * the buffer routines, even though we're not yet committed to a 642 * particular buffer method. 643 */ 644 bpf_buffer_init(d); 645 d->bd_bufmode = BPF_BUFMODE_BUFFER; 646 d->bd_sig = SIGIO; 647 d->bd_direction = BPF_D_INOUT; 648 d->bd_pid = td->td_proc->p_pid; 649#ifdef MAC 650 mac_bpfdesc_init(d); 651 mac_bpfdesc_create(td->td_ucred, d); 652#endif 653 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 654 callout_init(&d->bd_callout, CALLOUT_MPSAFE); 655 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_mtx); 656 657 return (0); 658} 659 660/* 661 * bpfread - read next chunk of packets from buffers 662 */ 663static int 664bpfread(struct cdev *dev, struct uio *uio, int ioflag) 665{ 666 struct bpf_d *d; 667 int error; 668 int non_block; 669 int timed_out; 670 671 error = devfs_get_cdevpriv((void **)&d); 672 if (error != 0) 673 return (error); 674 675 /* 676 * Restrict application to use a buffer the same size as 677 * as kernel buffers. 678 */ 679 if (uio->uio_resid != d->bd_bufsize) 680 return (EINVAL); 681 682 non_block = ((ioflag & O_NONBLOCK) != 0); 683 684 BPFD_LOCK(d); 685 d->bd_pid = curthread->td_proc->p_pid; 686 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 687 BPFD_UNLOCK(d); 688 return (EOPNOTSUPP); 689 } 690 if (d->bd_state == BPF_WAITING) 691 callout_stop(&d->bd_callout); 692 timed_out = (d->bd_state == BPF_TIMED_OUT); 693 d->bd_state = BPF_IDLE; 694 /* 695 * If the hold buffer is empty, then do a timed sleep, which 696 * ends when the timeout expires or when enough packets 697 * have arrived to fill the store buffer. 698 */ 699 while (d->bd_hbuf == NULL) { 700 if (d->bd_slen != 0) { 701 /* 702 * A packet(s) either arrived since the previous 703 * read or arrived while we were asleep. 704 */ 705 if (d->bd_immediate || non_block || timed_out) { 706 /* 707 * Rotate the buffers and return what's here 708 * if we are in immediate mode, non-blocking 709 * flag is set, or this descriptor timed out. 710 */ 711 ROTATE_BUFFERS(d); 712 break; 713 } 714 } 715 716 /* 717 * No data is available, check to see if the bpf device 718 * is still pointed at a real interface. If not, return 719 * ENXIO so that the userland process knows to rebind 720 * it before using it again. 721 */ 722 if (d->bd_bif == NULL) { 723 BPFD_UNLOCK(d); 724 return (ENXIO); 725 } 726 727 if (non_block) { 728 BPFD_UNLOCK(d); 729 return (EWOULDBLOCK); 730 } 731 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 732 "bpf", d->bd_rtout); 733 if (error == EINTR || error == ERESTART) { 734 BPFD_UNLOCK(d); 735 return (error); 736 } 737 if (error == EWOULDBLOCK) { 738 /* 739 * On a timeout, return what's in the buffer, 740 * which may be nothing. If there is something 741 * in the store buffer, we can rotate the buffers. 742 */ 743 if (d->bd_hbuf) 744 /* 745 * We filled up the buffer in between 746 * getting the timeout and arriving 747 * here, so we don't need to rotate. 748 */ 749 break; 750 751 if (d->bd_slen == 0) { 752 BPFD_UNLOCK(d); 753 return (0); 754 } 755 ROTATE_BUFFERS(d); 756 break; 757 } 758 } 759 /* 760 * At this point, we know we have something in the hold slot. 761 */ 762 BPFD_UNLOCK(d); 763 764 /* 765 * Move data from hold buffer into user space. 766 * We know the entire buffer is transferred since 767 * we checked above that the read buffer is bpf_bufsize bytes. 768 * 769 * XXXRW: More synchronization needed here: what if a second thread 770 * issues a read on the same fd at the same time? Don't want this 771 * getting invalidated. 772 */ 773 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 774 775 BPFD_LOCK(d); 776 d->bd_fbuf = d->bd_hbuf; 777 d->bd_hbuf = NULL; 778 d->bd_hlen = 0; 779 bpf_buf_reclaimed(d); 780 BPFD_UNLOCK(d); 781 782 return (error); 783} 784 785/* 786 * If there are processes sleeping on this descriptor, wake them up. 787 */ 788static __inline void 789bpf_wakeup(struct bpf_d *d) 790{ 791 792 BPFD_LOCK_ASSERT(d); 793 if (d->bd_state == BPF_WAITING) { 794 callout_stop(&d->bd_callout); 795 d->bd_state = BPF_IDLE; 796 } 797 wakeup(d); 798 if (d->bd_async && d->bd_sig && d->bd_sigio) 799 pgsigio(&d->bd_sigio, d->bd_sig, 0); 800 801 selwakeuppri(&d->bd_sel, PRINET); 802 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 803} 804 805static void 806bpf_timed_out(void *arg) 807{ 808 struct bpf_d *d = (struct bpf_d *)arg; 809 810 BPFD_LOCK(d); 811 if (d->bd_state == BPF_WAITING) { 812 d->bd_state = BPF_TIMED_OUT; 813 if (d->bd_slen != 0) 814 bpf_wakeup(d); 815 } 816 BPFD_UNLOCK(d); 817} 818 819static int 820bpf_ready(struct bpf_d *d) 821{ 822 823 BPFD_LOCK_ASSERT(d); 824 825 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 826 return (1); 827 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 828 d->bd_slen != 0) 829 return (1); 830 return (0); 831} 832 833static int 834bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 835{ 836 struct bpf_d *d; 837 struct ifnet *ifp; 838 struct mbuf *m, *mc; 839 struct sockaddr dst; 840 int error, hlen; 841 842 error = devfs_get_cdevpriv((void **)&d); 843 if (error != 0) 844 return (error); 845 846 d->bd_pid = curthread->td_proc->p_pid; 847 d->bd_wcount++; 848 if (d->bd_bif == NULL) { 849 d->bd_wdcount++; 850 return (ENXIO); 851 } 852 853 ifp = d->bd_bif->bif_ifp; 854 855 if ((ifp->if_flags & IFF_UP) == 0) { 856 d->bd_wdcount++; 857 return (ENETDOWN); 858 } 859 860 if (uio->uio_resid == 0) { 861 d->bd_wdcount++; 862 return (0); 863 } 864 865 bzero(&dst, sizeof(dst)); 866 m = NULL; 867 hlen = 0; 868 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 869 &m, &dst, &hlen, d->bd_wfilter); 870 if (error) { 871 d->bd_wdcount++; 872 return (error); 873 } 874 d->bd_wfcount++; 875 if (d->bd_hdrcmplt) 876 dst.sa_family = pseudo_AF_HDRCMPLT; 877 878 if (d->bd_feedback) { 879 mc = m_dup(m, M_DONTWAIT); 880 if (mc != NULL) 881 mc->m_pkthdr.rcvif = ifp; 882 /* Set M_PROMISC for outgoing packets to be discarded. */ 883 if (d->bd_direction == BPF_D_INOUT) 884 m->m_flags |= M_PROMISC; 885 } else 886 mc = NULL; 887 888 m->m_pkthdr.len -= hlen; 889 m->m_len -= hlen; 890 m->m_data += hlen; /* XXX */ 891 892 CURVNET_SET(ifp->if_vnet); 893#ifdef MAC 894 BPFD_LOCK(d); 895 mac_bpfdesc_create_mbuf(d, m); 896 if (mc != NULL) 897 mac_bpfdesc_create_mbuf(d, mc); 898 BPFD_UNLOCK(d); 899#endif 900 901 error = (*ifp->if_output)(ifp, m, &dst, NULL); 902 if (error) 903 d->bd_wdcount++; 904 905 if (mc != NULL) { 906 if (error == 0) 907 (*ifp->if_input)(ifp, mc); 908 else 909 m_freem(mc); 910 } 911 CURVNET_RESTORE(); 912 913 return (error); 914} 915 916/* 917 * Reset a descriptor by flushing its packet buffer and clearing the receive 918 * and drop counts. This is doable for kernel-only buffers, but with 919 * zero-copy buffers, we can't write to (or rotate) buffers that are 920 * currently owned by userspace. It would be nice if we could encapsulate 921 * this logic in the buffer code rather than here. 922 */ 923static void 924reset_d(struct bpf_d *d) 925{ 926 927 mtx_assert(&d->bd_mtx, MA_OWNED); 928 929 if ((d->bd_hbuf != NULL) && 930 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 931 /* Free the hold buffer. */ 932 d->bd_fbuf = d->bd_hbuf; 933 d->bd_hbuf = NULL; 934 d->bd_hlen = 0; 935 bpf_buf_reclaimed(d); 936 } 937 if (bpf_canwritebuf(d)) 938 d->bd_slen = 0; 939 d->bd_rcount = 0; 940 d->bd_dcount = 0; 941 d->bd_fcount = 0; 942 d->bd_wcount = 0; 943 d->bd_wfcount = 0; 944 d->bd_wdcount = 0; 945 d->bd_zcopy = 0; 946} 947 948/* 949 * FIONREAD Check for read packet available. 950 * SIOCGIFADDR Get interface address - convenient hook to driver. 951 * BIOCGBLEN Get buffer len [for read()]. 952 * BIOCSETF Set read filter. 953 * BIOCSETFNR Set read filter without resetting descriptor. 954 * BIOCSETWF Set write filter. 955 * BIOCFLUSH Flush read packet buffer. 956 * BIOCPROMISC Put interface into promiscuous mode. 957 * BIOCGDLT Get link layer type. 958 * BIOCGETIF Get interface name. 959 * BIOCSETIF Set interface. 960 * BIOCSRTIMEOUT Set read timeout. 961 * BIOCGRTIMEOUT Get read timeout. 962 * BIOCGSTATS Get packet stats. 963 * BIOCIMMEDIATE Set immediate mode. 964 * BIOCVERSION Get filter language version. 965 * BIOCGHDRCMPLT Get "header already complete" flag 966 * BIOCSHDRCMPLT Set "header already complete" flag 967 * BIOCGDIRECTION Get packet direction flag 968 * BIOCSDIRECTION Set packet direction flag 969 * BIOCLOCK Set "locked" flag 970 * BIOCFEEDBACK Set packet feedback mode. 971 * BIOCSETZBUF Set current zero-copy buffer locations. 972 * BIOCGETZMAX Get maximum zero-copy buffer size. 973 * BIOCROTZBUF Force rotation of zero-copy buffer 974 * BIOCSETBUFMODE Set buffer mode. 975 * BIOCGETBUFMODE Get current buffer mode. 976 */ 977/* ARGSUSED */ 978static int 979bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 980 struct thread *td) 981{ 982 struct bpf_d *d; 983 int error; 984 985 error = devfs_get_cdevpriv((void **)&d); 986 if (error != 0) 987 return (error); 988 989 /* 990 * Refresh PID associated with this descriptor. 991 */ 992 BPFD_LOCK(d); 993 d->bd_pid = td->td_proc->p_pid; 994 if (d->bd_state == BPF_WAITING) 995 callout_stop(&d->bd_callout); 996 d->bd_state = BPF_IDLE; 997 BPFD_UNLOCK(d); 998 999 if (d->bd_locked == 1) { 1000 switch (cmd) { 1001 case BIOCGBLEN: 1002 case BIOCFLUSH: 1003 case BIOCGDLT: 1004 case BIOCGDLTLIST: 1005 case BIOCGETIF: 1006 case BIOCGRTIMEOUT: 1007 case BIOCGSTATS: 1008 case BIOCVERSION: 1009 case BIOCGRSIG: 1010 case BIOCGHDRCMPLT: 1011 case BIOCFEEDBACK: 1012 case FIONREAD: 1013 case BIOCLOCK: 1014 case BIOCSRTIMEOUT: 1015 case BIOCIMMEDIATE: 1016 case TIOCGPGRP: 1017 case BIOCROTZBUF: 1018 break; 1019 default: 1020 return (EPERM); 1021 } 1022 } 1023 CURVNET_SET(TD_TO_VNET(td)); 1024 switch (cmd) { 1025 1026 default: 1027 error = EINVAL; 1028 break; 1029 1030 /* 1031 * Check for read packet available. 1032 */ 1033 case FIONREAD: 1034 { 1035 int n; 1036 1037 BPFD_LOCK(d); 1038 n = d->bd_slen; 1039 if (d->bd_hbuf) 1040 n += d->bd_hlen; 1041 BPFD_UNLOCK(d); 1042 1043 *(int *)addr = n; 1044 break; 1045 } 1046 1047 case SIOCGIFADDR: 1048 { 1049 struct ifnet *ifp; 1050 1051 if (d->bd_bif == NULL) 1052 error = EINVAL; 1053 else { 1054 ifp = d->bd_bif->bif_ifp; 1055 error = (*ifp->if_ioctl)(ifp, cmd, addr); 1056 } 1057 break; 1058 } 1059 1060 /* 1061 * Get buffer len [for read()]. 1062 */ 1063 case BIOCGBLEN: 1064 *(u_int *)addr = d->bd_bufsize; 1065 break; 1066 1067 /* 1068 * Set buffer length. 1069 */ 1070 case BIOCSBLEN: 1071 error = bpf_ioctl_sblen(d, (u_int *)addr); 1072 break; 1073 1074 /* 1075 * Set link layer read filter. 1076 */ 1077 case BIOCSETF: 1078 case BIOCSETFNR: 1079 case BIOCSETWF: 1080 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1081 break; 1082 1083 /* 1084 * Flush read packet buffer. 1085 */ 1086 case BIOCFLUSH: 1087 BPFD_LOCK(d); 1088 reset_d(d); 1089 BPFD_UNLOCK(d); 1090 break; 1091 1092 /* 1093 * Put interface into promiscuous mode. 1094 */ 1095 case BIOCPROMISC: 1096 if (d->bd_bif == NULL) { 1097 /* 1098 * No interface attached yet. 1099 */ 1100 error = EINVAL; 1101 break; 1102 } 1103 if (d->bd_promisc == 0) { 1104 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1105 if (error == 0) 1106 d->bd_promisc = 1; 1107 } 1108 break; 1109 1110 /* 1111 * Get current data link type. 1112 */ 1113 case BIOCGDLT: 1114 if (d->bd_bif == NULL) 1115 error = EINVAL; 1116 else 1117 *(u_int *)addr = d->bd_bif->bif_dlt; 1118 break; 1119 1120 /* 1121 * Get a list of supported data link types. 1122 */ 1123 case BIOCGDLTLIST: 1124 if (d->bd_bif == NULL) 1125 error = EINVAL; 1126 else 1127 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1128 break; 1129 1130 /* 1131 * Set data link type. 1132 */ 1133 case BIOCSDLT: 1134 if (d->bd_bif == NULL) 1135 error = EINVAL; 1136 else 1137 error = bpf_setdlt(d, *(u_int *)addr); 1138 break; 1139 1140 /* 1141 * Get interface name. 1142 */ 1143 case BIOCGETIF: 1144 if (d->bd_bif == NULL) 1145 error = EINVAL; 1146 else { 1147 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1148 struct ifreq *const ifr = (struct ifreq *)addr; 1149 1150 strlcpy(ifr->ifr_name, ifp->if_xname, 1151 sizeof(ifr->ifr_name)); 1152 } 1153 break; 1154 1155 /* 1156 * Set interface. 1157 */ 1158 case BIOCSETIF: 1159 error = bpf_setif(d, (struct ifreq *)addr); 1160 break; 1161 1162 /* 1163 * Set read timeout. 1164 */ 1165 case BIOCSRTIMEOUT: 1166 { 1167 struct timeval *tv = (struct timeval *)addr; 1168 1169 /* 1170 * Subtract 1 tick from tvtohz() since this isn't 1171 * a one-shot timer. 1172 */ 1173 if ((error = itimerfix(tv)) == 0) 1174 d->bd_rtout = tvtohz(tv) - 1; 1175 break; 1176 } 1177 1178 /* 1179 * Get read timeout. 1180 */ 1181 case BIOCGRTIMEOUT: 1182 { 1183 struct timeval *tv = (struct timeval *)addr; 1184 1185 tv->tv_sec = d->bd_rtout / hz; 1186 tv->tv_usec = (d->bd_rtout % hz) * tick; 1187 break; 1188 } 1189 1190 /* 1191 * Get packet stats. 1192 */ 1193 case BIOCGSTATS: 1194 { 1195 struct bpf_stat *bs = (struct bpf_stat *)addr; 1196 1197 /* XXXCSJP overflow */ 1198 bs->bs_recv = d->bd_rcount; 1199 bs->bs_drop = d->bd_dcount; 1200 break; 1201 } 1202 1203 /* 1204 * Set immediate mode. 1205 */ 1206 case BIOCIMMEDIATE: 1207 d->bd_immediate = *(u_int *)addr; 1208 break; 1209 1210 case BIOCVERSION: 1211 { 1212 struct bpf_version *bv = (struct bpf_version *)addr; 1213 1214 bv->bv_major = BPF_MAJOR_VERSION; 1215 bv->bv_minor = BPF_MINOR_VERSION; 1216 break; 1217 } 1218 1219 /* 1220 * Get "header already complete" flag 1221 */ 1222 case BIOCGHDRCMPLT: 1223 *(u_int *)addr = d->bd_hdrcmplt; 1224 break; 1225 1226 /* 1227 * Set "header already complete" flag 1228 */ 1229 case BIOCSHDRCMPLT: 1230 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1231 break; 1232 1233 /* 1234 * Get packet direction flag 1235 */ 1236 case BIOCGDIRECTION: 1237 *(u_int *)addr = d->bd_direction; 1238 break; 1239 1240 /* 1241 * Set packet direction flag 1242 */ 1243 case BIOCSDIRECTION: 1244 { 1245 u_int direction; 1246 1247 direction = *(u_int *)addr; 1248 switch (direction) { 1249 case BPF_D_IN: 1250 case BPF_D_INOUT: 1251 case BPF_D_OUT: 1252 d->bd_direction = direction; 1253 break; 1254 default: 1255 error = EINVAL; 1256 } 1257 } 1258 break; 1259 1260 case BIOCFEEDBACK: 1261 d->bd_feedback = *(u_int *)addr; 1262 break; 1263 1264 case BIOCLOCK: 1265 d->bd_locked = 1; 1266 break; 1267 1268 case FIONBIO: /* Non-blocking I/O */ 1269 break; 1270 1271 case FIOASYNC: /* Send signal on receive packets */ 1272 d->bd_async = *(int *)addr; 1273 break; 1274 1275 case FIOSETOWN: 1276 error = fsetown(*(int *)addr, &d->bd_sigio); 1277 break; 1278 1279 case FIOGETOWN: 1280 *(int *)addr = fgetown(&d->bd_sigio); 1281 break; 1282 1283 /* This is deprecated, FIOSETOWN should be used instead. */ 1284 case TIOCSPGRP: 1285 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1286 break; 1287 1288 /* This is deprecated, FIOGETOWN should be used instead. */ 1289 case TIOCGPGRP: 1290 *(int *)addr = -fgetown(&d->bd_sigio); 1291 break; 1292 1293 case BIOCSRSIG: /* Set receive signal */ 1294 { 1295 u_int sig; 1296 1297 sig = *(u_int *)addr; 1298 1299 if (sig >= NSIG) 1300 error = EINVAL; 1301 else 1302 d->bd_sig = sig; 1303 break; 1304 } 1305 case BIOCGRSIG: 1306 *(u_int *)addr = d->bd_sig; 1307 break; 1308 1309 case BIOCGETBUFMODE: 1310 *(u_int *)addr = d->bd_bufmode; 1311 break; 1312 1313 case BIOCSETBUFMODE: 1314 /* 1315 * Allow the buffering mode to be changed as long as we 1316 * haven't yet committed to a particular mode. Our 1317 * definition of commitment, for now, is whether or not a 1318 * buffer has been allocated or an interface attached, since 1319 * that's the point where things get tricky. 1320 */ 1321 switch (*(u_int *)addr) { 1322 case BPF_BUFMODE_BUFFER: 1323 break; 1324 1325 case BPF_BUFMODE_ZBUF: 1326 if (bpf_zerocopy_enable) 1327 break; 1328 /* FALLSTHROUGH */ 1329 1330 default: 1331 return (EINVAL); 1332 } 1333 1334 BPFD_LOCK(d); 1335 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1336 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1337 BPFD_UNLOCK(d); 1338 return (EBUSY); 1339 } 1340 d->bd_bufmode = *(u_int *)addr; 1341 BPFD_UNLOCK(d); 1342 break; 1343 1344 case BIOCGETZMAX: 1345 return (bpf_ioctl_getzmax(td, d, (size_t *)addr)); 1346 1347 case BIOCSETZBUF: 1348 return (bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr)); 1349 1350 case BIOCROTZBUF: 1351 return (bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr)); 1352 } 1353 CURVNET_RESTORE(); 1354 return (error); 1355} 1356 1357/* 1358 * Set d's packet filter program to fp. If this file already has a filter, 1359 * free it and replace it. Returns EINVAL for bogus requests. 1360 */ 1361static int 1362bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1363{ 1364 struct bpf_insn *fcode, *old; 1365 u_int wfilter, flen, size; 1366#ifdef BPF_JITTER 1367 bpf_jit_filter *ofunc; 1368#endif 1369 1370 if (cmd == BIOCSETWF) { 1371 old = d->bd_wfilter; 1372 wfilter = 1; 1373#ifdef BPF_JITTER 1374 ofunc = NULL; 1375#endif 1376 } else { 1377 wfilter = 0; 1378 old = d->bd_rfilter; 1379#ifdef BPF_JITTER 1380 ofunc = d->bd_bfilter; 1381#endif 1382 } 1383 if (fp->bf_insns == NULL) { 1384 if (fp->bf_len != 0) 1385 return (EINVAL); 1386 BPFD_LOCK(d); 1387 if (wfilter) 1388 d->bd_wfilter = NULL; 1389 else { 1390 d->bd_rfilter = NULL; 1391#ifdef BPF_JITTER 1392 d->bd_bfilter = NULL; 1393#endif 1394 if (cmd == BIOCSETF) 1395 reset_d(d); 1396 } 1397 BPFD_UNLOCK(d); 1398 if (old != NULL) 1399 free((caddr_t)old, M_BPF); 1400#ifdef BPF_JITTER 1401 if (ofunc != NULL) 1402 bpf_destroy_jit_filter(ofunc); 1403#endif 1404 return (0); 1405 } 1406 flen = fp->bf_len; 1407 if (flen > bpf_maxinsns) 1408 return (EINVAL); 1409 1410 size = flen * sizeof(*fp->bf_insns); 1411 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 1412 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 1413 bpf_validate(fcode, (int)flen)) { 1414 BPFD_LOCK(d); 1415 if (wfilter) 1416 d->bd_wfilter = fcode; 1417 else { 1418 d->bd_rfilter = fcode; 1419#ifdef BPF_JITTER 1420 d->bd_bfilter = bpf_jitter(fcode, flen); 1421#endif 1422 if (cmd == BIOCSETF) 1423 reset_d(d); 1424 } 1425 BPFD_UNLOCK(d); 1426 if (old != NULL) 1427 free((caddr_t)old, M_BPF); 1428#ifdef BPF_JITTER 1429 if (ofunc != NULL) 1430 bpf_destroy_jit_filter(ofunc); 1431#endif 1432 1433 return (0); 1434 } 1435 free((caddr_t)fcode, M_BPF); 1436 return (EINVAL); 1437} 1438 1439/* 1440 * Detach a file from its current interface (if attached at all) and attach 1441 * to the interface indicated by the name stored in ifr. 1442 * Return an errno or 0. 1443 */ 1444static int 1445bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1446{ 1447 struct bpf_if *bp; 1448 struct ifnet *theywant; 1449 1450 theywant = ifunit(ifr->ifr_name); 1451 if (theywant == NULL || theywant->if_bpf == NULL) 1452 return (ENXIO); 1453 1454 bp = theywant->if_bpf; 1455 1456 /* 1457 * Behavior here depends on the buffering model. If we're using 1458 * kernel memory buffers, then we can allocate them here. If we're 1459 * using zero-copy, then the user process must have registered 1460 * buffers by the time we get here. If not, return an error. 1461 * 1462 * XXXRW: There are locking issues here with multi-threaded use: what 1463 * if two threads try to set the interface at once? 1464 */ 1465 switch (d->bd_bufmode) { 1466 case BPF_BUFMODE_BUFFER: 1467 if (d->bd_sbuf == NULL) 1468 bpf_buffer_alloc(d); 1469 KASSERT(d->bd_sbuf != NULL, ("bpf_setif: bd_sbuf NULL")); 1470 break; 1471 1472 case BPF_BUFMODE_ZBUF: 1473 if (d->bd_sbuf == NULL) 1474 return (EINVAL); 1475 break; 1476 1477 default: 1478 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1479 } 1480 if (bp != d->bd_bif) { 1481 if (d->bd_bif) 1482 /* 1483 * Detach if attached to something else. 1484 */ 1485 bpf_detachd(d); 1486 1487 bpf_attachd(d, bp); 1488 } 1489 BPFD_LOCK(d); 1490 reset_d(d); 1491 BPFD_UNLOCK(d); 1492 return (0); 1493} 1494 1495/* 1496 * Support for select() and poll() system calls 1497 * 1498 * Return true iff the specific operation will not block indefinitely. 1499 * Otherwise, return false but make a note that a selwakeup() must be done. 1500 */ 1501static int 1502bpfpoll(struct cdev *dev, int events, struct thread *td) 1503{ 1504 struct bpf_d *d; 1505 int revents; 1506 1507 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 1508 return (events & 1509 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 1510 1511 /* 1512 * Refresh PID associated with this descriptor. 1513 */ 1514 revents = events & (POLLOUT | POLLWRNORM); 1515 BPFD_LOCK(d); 1516 d->bd_pid = td->td_proc->p_pid; 1517 if (events & (POLLIN | POLLRDNORM)) { 1518 if (bpf_ready(d)) 1519 revents |= events & (POLLIN | POLLRDNORM); 1520 else { 1521 selrecord(td, &d->bd_sel); 1522 /* Start the read timeout if necessary. */ 1523 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1524 callout_reset(&d->bd_callout, d->bd_rtout, 1525 bpf_timed_out, d); 1526 d->bd_state = BPF_WAITING; 1527 } 1528 } 1529 } 1530 BPFD_UNLOCK(d); 1531 return (revents); 1532} 1533 1534/* 1535 * Support for kevent() system call. Register EVFILT_READ filters and 1536 * reject all others. 1537 */ 1538int 1539bpfkqfilter(struct cdev *dev, struct knote *kn) 1540{ 1541 struct bpf_d *d; 1542 1543 if (devfs_get_cdevpriv((void **)&d) != 0 || 1544 kn->kn_filter != EVFILT_READ) 1545 return (1); 1546 1547 /* 1548 * Refresh PID associated with this descriptor. 1549 */ 1550 BPFD_LOCK(d); 1551 d->bd_pid = curthread->td_proc->p_pid; 1552 kn->kn_fop = &bpfread_filtops; 1553 kn->kn_hook = d; 1554 knlist_add(&d->bd_sel.si_note, kn, 1); 1555 BPFD_UNLOCK(d); 1556 1557 return (0); 1558} 1559 1560static void 1561filt_bpfdetach(struct knote *kn) 1562{ 1563 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1564 1565 knlist_remove(&d->bd_sel.si_note, kn, 0); 1566} 1567 1568static int 1569filt_bpfread(struct knote *kn, long hint) 1570{ 1571 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1572 int ready; 1573 1574 BPFD_LOCK_ASSERT(d); 1575 ready = bpf_ready(d); 1576 if (ready) { 1577 kn->kn_data = d->bd_slen; 1578 if (d->bd_hbuf) 1579 kn->kn_data += d->bd_hlen; 1580 } 1581 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1582 callout_reset(&d->bd_callout, d->bd_rtout, 1583 bpf_timed_out, d); 1584 d->bd_state = BPF_WAITING; 1585 } 1586 1587 return (ready); 1588} 1589 1590/* 1591 * Incoming linkage from device drivers. Process the packet pkt, of length 1592 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1593 * by each process' filter, and if accepted, stashed into the corresponding 1594 * buffer. 1595 */ 1596void 1597bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1598{ 1599 struct bpf_d *d; 1600#ifdef BPF_JITTER 1601 bpf_jit_filter *bf; 1602#endif 1603 u_int slen; 1604 int gottime; 1605 struct timeval tv; 1606 1607 gottime = 0; 1608 BPFIF_LOCK(bp); 1609 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1610 BPFD_LOCK(d); 1611 ++d->bd_rcount; 1612 /* 1613 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no 1614 * way for the caller to indiciate to us whether this packet 1615 * is inbound or outbound. In the bpf_mtap() routines, we use 1616 * the interface pointers on the mbuf to figure it out. 1617 */ 1618#ifdef BPF_JITTER 1619 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 1620 if (bf != NULL) 1621 slen = (*(bf->func))(pkt, pktlen, pktlen); 1622 else 1623#endif 1624 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1625 if (slen != 0) { 1626 d->bd_fcount++; 1627 if (!gottime) { 1628 microtime(&tv); 1629 gottime = 1; 1630 } 1631#ifdef MAC 1632 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1633#endif 1634 catchpacket(d, pkt, pktlen, slen, 1635 bpf_append_bytes, &tv); 1636 } 1637 BPFD_UNLOCK(d); 1638 } 1639 BPFIF_UNLOCK(bp); 1640} 1641 1642#define BPF_CHECK_DIRECTION(d, r, i) \ 1643 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 1644 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 1645 1646/* 1647 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1648 */ 1649void 1650bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1651{ 1652 struct bpf_d *d; 1653#ifdef BPF_JITTER 1654 bpf_jit_filter *bf; 1655#endif 1656 u_int pktlen, slen; 1657 int gottime; 1658 struct timeval tv; 1659 1660 /* Skip outgoing duplicate packets. */ 1661 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 1662 m->m_flags &= ~M_PROMISC; 1663 return; 1664 } 1665 1666 gottime = 0; 1667 1668 pktlen = m_length(m, NULL); 1669 1670 BPFIF_LOCK(bp); 1671 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1672 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 1673 continue; 1674 BPFD_LOCK(d); 1675 ++d->bd_rcount; 1676#ifdef BPF_JITTER 1677 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 1678 /* XXX We cannot handle multiple mbufs. */ 1679 if (bf != NULL && m->m_next == NULL) 1680 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); 1681 else 1682#endif 1683 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1684 if (slen != 0) { 1685 d->bd_fcount++; 1686 if (!gottime) { 1687 microtime(&tv); 1688 gottime = 1; 1689 } 1690#ifdef MAC 1691 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1692#endif 1693 catchpacket(d, (u_char *)m, pktlen, slen, 1694 bpf_append_mbuf, &tv); 1695 } 1696 BPFD_UNLOCK(d); 1697 } 1698 BPFIF_UNLOCK(bp); 1699} 1700 1701/* 1702 * Incoming linkage from device drivers, when packet is in 1703 * an mbuf chain and to be prepended by a contiguous header. 1704 */ 1705void 1706bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1707{ 1708 struct mbuf mb; 1709 struct bpf_d *d; 1710 u_int pktlen, slen; 1711 int gottime; 1712 struct timeval tv; 1713 1714 /* Skip outgoing duplicate packets. */ 1715 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 1716 m->m_flags &= ~M_PROMISC; 1717 return; 1718 } 1719 1720 gottime = 0; 1721 1722 pktlen = m_length(m, NULL); 1723 /* 1724 * Craft on-stack mbuf suitable for passing to bpf_filter. 1725 * Note that we cut corners here; we only setup what's 1726 * absolutely needed--this mbuf should never go anywhere else. 1727 */ 1728 mb.m_next = m; 1729 mb.m_data = data; 1730 mb.m_len = dlen; 1731 pktlen += dlen; 1732 1733 BPFIF_LOCK(bp); 1734 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1735 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 1736 continue; 1737 BPFD_LOCK(d); 1738 ++d->bd_rcount; 1739 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 1740 if (slen != 0) { 1741 d->bd_fcount++; 1742 if (!gottime) { 1743 microtime(&tv); 1744 gottime = 1; 1745 } 1746#ifdef MAC 1747 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1748#endif 1749 catchpacket(d, (u_char *)&mb, pktlen, slen, 1750 bpf_append_mbuf, &tv); 1751 } 1752 BPFD_UNLOCK(d); 1753 } 1754 BPFIF_UNLOCK(bp); 1755} 1756 1757#undef BPF_CHECK_DIRECTION 1758 1759/* 1760 * Move the packet data from interface memory (pkt) into the 1761 * store buffer. "cpfn" is the routine called to do the actual data 1762 * transfer. bcopy is passed in to copy contiguous chunks, while 1763 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 1764 * pkt is really an mbuf. 1765 */ 1766static void 1767catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1768 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 1769 struct timeval *tv) 1770{ 1771 struct bpf_hdr hdr; 1772 int totlen, curlen; 1773 int hdrlen = d->bd_bif->bif_hdrlen; 1774 int do_wakeup = 0; 1775 1776 BPFD_LOCK_ASSERT(d); 1777 1778 /* 1779 * Detect whether user space has released a buffer back to us, and if 1780 * so, move it from being a hold buffer to a free buffer. This may 1781 * not be the best place to do it (for example, we might only want to 1782 * run this check if we need the space), but for now it's a reliable 1783 * spot to do it. 1784 */ 1785 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 1786 d->bd_fbuf = d->bd_hbuf; 1787 d->bd_hbuf = NULL; 1788 d->bd_hlen = 0; 1789 bpf_buf_reclaimed(d); 1790 } 1791 1792 /* 1793 * Figure out how many bytes to move. If the packet is 1794 * greater or equal to the snapshot length, transfer that 1795 * much. Otherwise, transfer the whole packet (unless 1796 * we hit the buffer size limit). 1797 */ 1798 totlen = hdrlen + min(snaplen, pktlen); 1799 if (totlen > d->bd_bufsize) 1800 totlen = d->bd_bufsize; 1801 1802 /* 1803 * Round up the end of the previous packet to the next longword. 1804 * 1805 * Drop the packet if there's no room and no hope of room 1806 * If the packet would overflow the storage buffer or the storage 1807 * buffer is considered immutable by the buffer model, try to rotate 1808 * the buffer and wakeup pending processes. 1809 */ 1810 curlen = BPF_WORDALIGN(d->bd_slen); 1811 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 1812 if (d->bd_fbuf == NULL) { 1813 /* 1814 * There's no room in the store buffer, and no 1815 * prospect of room, so drop the packet. Notify the 1816 * buffer model. 1817 */ 1818 bpf_buffull(d); 1819 ++d->bd_dcount; 1820 return; 1821 } 1822 ROTATE_BUFFERS(d); 1823 do_wakeup = 1; 1824 curlen = 0; 1825 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1826 /* 1827 * Immediate mode is set, or the read timeout has already 1828 * expired during a select call. A packet arrived, so the 1829 * reader should be woken up. 1830 */ 1831 do_wakeup = 1; 1832 1833 /* 1834 * Append the bpf header. Note we append the actual header size, but 1835 * move forward the length of the header plus padding. 1836 */ 1837 bzero(&hdr, sizeof(hdr)); 1838 hdr.bh_tstamp = *tv; 1839 hdr.bh_datalen = pktlen; 1840 hdr.bh_hdrlen = hdrlen; 1841 hdr.bh_caplen = totlen - hdrlen; 1842 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 1843 1844 /* 1845 * Copy the packet data into the store buffer and update its length. 1846 */ 1847 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, hdr.bh_caplen); 1848 d->bd_slen = curlen + totlen; 1849 1850 if (do_wakeup) 1851 bpf_wakeup(d); 1852} 1853 1854/* 1855 * Free buffers currently in use by a descriptor. 1856 * Called on close. 1857 */ 1858static void 1859bpf_freed(struct bpf_d *d) 1860{ 1861 1862 /* 1863 * We don't need to lock out interrupts since this descriptor has 1864 * been detached from its interface and it yet hasn't been marked 1865 * free. 1866 */ 1867 bpf_free(d); 1868 if (d->bd_rfilter) { 1869 free((caddr_t)d->bd_rfilter, M_BPF); 1870#ifdef BPF_JITTER 1871 bpf_destroy_jit_filter(d->bd_bfilter); 1872#endif 1873 } 1874 if (d->bd_wfilter) 1875 free((caddr_t)d->bd_wfilter, M_BPF); 1876 mtx_destroy(&d->bd_mtx); 1877} 1878 1879/* 1880 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1881 * fixed size of the link header (variable length headers not yet supported). 1882 */ 1883void 1884bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1885{ 1886 1887 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1888} 1889 1890/* 1891 * Attach an interface to bpf. ifp is a pointer to the structure 1892 * defining the interface to be attached, dlt is the link layer type, 1893 * and hdrlen is the fixed size of the link header (variable length 1894 * headers are not yet supporrted). 1895 */ 1896void 1897bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1898{ 1899 struct bpf_if *bp; 1900 1901 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1902 if (bp == NULL) 1903 panic("bpfattach"); 1904 1905 LIST_INIT(&bp->bif_dlist); 1906 bp->bif_ifp = ifp; 1907 bp->bif_dlt = dlt; 1908 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1909 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 1910 *driverp = bp; 1911 1912 mtx_lock(&bpf_mtx); 1913 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1914 mtx_unlock(&bpf_mtx); 1915 1916 /* 1917 * Compute the length of the bpf header. This is not necessarily 1918 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1919 * that the network layer header begins on a longword boundary (for 1920 * performance reasons and to alleviate alignment restrictions). 1921 */ 1922 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1923 1924 if (bootverbose) 1925 if_printf(ifp, "bpf attached\n"); 1926} 1927 1928/* 1929 * Detach bpf from an interface. This involves detaching each descriptor 1930 * associated with the interface, and leaving bd_bif NULL. Notify each 1931 * descriptor as it's detached so that any sleepers wake up and get 1932 * ENXIO. 1933 */ 1934void 1935bpfdetach(struct ifnet *ifp) 1936{ 1937 struct bpf_if *bp; 1938 struct bpf_d *d; 1939 1940 /* Locate BPF interface information */ 1941 mtx_lock(&bpf_mtx); 1942 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1943 if (ifp == bp->bif_ifp) 1944 break; 1945 } 1946 1947 /* Interface wasn't attached */ 1948 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1949 mtx_unlock(&bpf_mtx); 1950 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1951 return; 1952 } 1953 1954 LIST_REMOVE(bp, bif_next); 1955 mtx_unlock(&bpf_mtx); 1956 1957 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1958 bpf_detachd(d); 1959 BPFD_LOCK(d); 1960 bpf_wakeup(d); 1961 BPFD_UNLOCK(d); 1962 } 1963 1964 mtx_destroy(&bp->bif_mtx); 1965 free(bp, M_BPF); 1966} 1967 1968/* 1969 * Get a list of available data link type of the interface. 1970 */ 1971static int 1972bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1973{ 1974 int n, error; 1975 struct ifnet *ifp; 1976 struct bpf_if *bp; 1977 1978 ifp = d->bd_bif->bif_ifp; 1979 n = 0; 1980 error = 0; 1981 mtx_lock(&bpf_mtx); 1982 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1983 if (bp->bif_ifp != ifp) 1984 continue; 1985 if (bfl->bfl_list != NULL) { 1986 if (n >= bfl->bfl_len) { 1987 mtx_unlock(&bpf_mtx); 1988 return (ENOMEM); 1989 } 1990 error = copyout(&bp->bif_dlt, 1991 bfl->bfl_list + n, sizeof(u_int)); 1992 } 1993 n++; 1994 } 1995 mtx_unlock(&bpf_mtx); 1996 bfl->bfl_len = n; 1997 return (error); 1998} 1999 2000/* 2001 * Set the data link type of a BPF instance. 2002 */ 2003static int 2004bpf_setdlt(struct bpf_d *d, u_int dlt) 2005{ 2006 int error, opromisc; 2007 struct ifnet *ifp; 2008 struct bpf_if *bp; 2009 2010 if (d->bd_bif->bif_dlt == dlt) 2011 return (0); 2012 ifp = d->bd_bif->bif_ifp; 2013 mtx_lock(&bpf_mtx); 2014 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2015 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2016 break; 2017 } 2018 mtx_unlock(&bpf_mtx); 2019 if (bp != NULL) { 2020 opromisc = d->bd_promisc; 2021 bpf_detachd(d); 2022 bpf_attachd(d, bp); 2023 BPFD_LOCK(d); 2024 reset_d(d); 2025 BPFD_UNLOCK(d); 2026 if (opromisc) { 2027 error = ifpromisc(bp->bif_ifp, 1); 2028 if (error) 2029 if_printf(bp->bif_ifp, 2030 "bpf_setdlt: ifpromisc failed (%d)\n", 2031 error); 2032 else 2033 d->bd_promisc = 1; 2034 } 2035 } 2036 return (bp == NULL ? EINVAL : 0); 2037} 2038 2039static void 2040bpf_drvinit(void *unused) 2041{ 2042 struct cdev *dev; 2043 2044 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2045 LIST_INIT(&bpf_iflist); 2046 2047 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2048 /* For compatibility */ 2049 make_dev_alias(dev, "bpf0"); 2050} 2051 2052/* 2053 * Zero out the various packet counters associated with all of the bpf 2054 * descriptors. At some point, we will probably want to get a bit more 2055 * granular and allow the user to specify descriptors to be zeroed. 2056 */ 2057static void 2058bpf_zero_counters(void) 2059{ 2060 struct bpf_if *bp; 2061 struct bpf_d *bd; 2062 2063 mtx_lock(&bpf_mtx); 2064 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2065 BPFIF_LOCK(bp); 2066 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2067 BPFD_LOCK(bd); 2068 bd->bd_rcount = 0; 2069 bd->bd_dcount = 0; 2070 bd->bd_fcount = 0; 2071 bd->bd_wcount = 0; 2072 bd->bd_wfcount = 0; 2073 bd->bd_zcopy = 0; 2074 BPFD_UNLOCK(bd); 2075 } 2076 BPFIF_UNLOCK(bp); 2077 } 2078 mtx_unlock(&bpf_mtx); 2079} 2080 2081static void 2082bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2083{ 2084 2085 bzero(d, sizeof(*d)); 2086 BPFD_LOCK_ASSERT(bd); 2087 d->bd_structsize = sizeof(*d); 2088 d->bd_immediate = bd->bd_immediate; 2089 d->bd_promisc = bd->bd_promisc; 2090 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2091 d->bd_direction = bd->bd_direction; 2092 d->bd_feedback = bd->bd_feedback; 2093 d->bd_async = bd->bd_async; 2094 d->bd_rcount = bd->bd_rcount; 2095 d->bd_dcount = bd->bd_dcount; 2096 d->bd_fcount = bd->bd_fcount; 2097 d->bd_sig = bd->bd_sig; 2098 d->bd_slen = bd->bd_slen; 2099 d->bd_hlen = bd->bd_hlen; 2100 d->bd_bufsize = bd->bd_bufsize; 2101 d->bd_pid = bd->bd_pid; 2102 strlcpy(d->bd_ifname, 2103 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2104 d->bd_locked = bd->bd_locked; 2105 d->bd_wcount = bd->bd_wcount; 2106 d->bd_wdcount = bd->bd_wdcount; 2107 d->bd_wfcount = bd->bd_wfcount; 2108 d->bd_zcopy = bd->bd_zcopy; 2109 d->bd_bufmode = bd->bd_bufmode; 2110} 2111 2112static int 2113bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2114{ 2115 struct xbpf_d *xbdbuf, *xbd, zerostats; 2116 int index, error; 2117 struct bpf_if *bp; 2118 struct bpf_d *bd; 2119 2120 /* 2121 * XXX This is not technically correct. It is possible for non 2122 * privileged users to open bpf devices. It would make sense 2123 * if the users who opened the devices were able to retrieve 2124 * the statistics for them, too. 2125 */ 2126 error = priv_check(req->td, PRIV_NET_BPF); 2127 if (error) 2128 return (error); 2129 /* 2130 * Check to see if the user is requesting that the counters be 2131 * zeroed out. Explicitly check that the supplied data is zeroed, 2132 * as we aren't allowing the user to set the counters currently. 2133 */ 2134 if (req->newptr != NULL) { 2135 if (req->newlen != sizeof(zerostats)) 2136 return (EINVAL); 2137 bzero(&zerostats, sizeof(zerostats)); 2138 xbd = req->newptr; 2139 if (bcmp(xbd, &zerostats, sizeof(*xbd)) != 0) 2140 return (EINVAL); 2141 bpf_zero_counters(); 2142 return (0); 2143 } 2144 if (req->oldptr == NULL) 2145 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2146 if (bpf_bpfd_cnt == 0) 2147 return (SYSCTL_OUT(req, 0, 0)); 2148 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2149 mtx_lock(&bpf_mtx); 2150 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2151 mtx_unlock(&bpf_mtx); 2152 free(xbdbuf, M_BPF); 2153 return (ENOMEM); 2154 } 2155 index = 0; 2156 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2157 BPFIF_LOCK(bp); 2158 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2159 xbd = &xbdbuf[index++]; 2160 BPFD_LOCK(bd); 2161 bpfstats_fill_xbpf(xbd, bd); 2162 BPFD_UNLOCK(bd); 2163 } 2164 BPFIF_UNLOCK(bp); 2165 } 2166 mtx_unlock(&bpf_mtx); 2167 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2168 free(xbdbuf, M_BPF); 2169 return (error); 2170} 2171 2172SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2173 2174#else /* !DEV_BPF && !NETGRAPH_BPF */ 2175/* 2176 * NOP stubs to allow bpf-using drivers to load and function. 2177 * 2178 * A 'better' implementation would allow the core bpf functionality 2179 * to be loaded at runtime. 2180 */ 2181static struct bpf_if bp_null; 2182 2183void 2184bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2185{ 2186} 2187 2188void 2189bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2190{ 2191} 2192 2193void 2194bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2195{ 2196} 2197 2198void 2199bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2200{ 2201 2202 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2203} 2204 2205void 2206bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2207{ 2208 2209 *driverp = &bp_null; 2210} 2211 2212void 2213bpfdetach(struct ifnet *ifp) 2214{ 2215} 2216 2217u_int 2218bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 2219{ 2220 return -1; /* "no filter" behaviour */ 2221} 2222 2223int 2224bpf_validate(const struct bpf_insn *f, int len) 2225{ 2226 return 0; /* false */ 2227} 2228 2229#endif /* !DEV_BPF && !NETGRAPH_BPF */ 2230