bpf.c revision 245878
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 245878 2013-01-24 14:29:31Z glebius $"); 39 40#include "opt_bpf.h" 41#include "opt_compat.h" 42#include "opt_netgraph.h" 43 44#include <sys/types.h> 45#include <sys/param.h> 46#include <sys/lock.h> 47#include <sys/rwlock.h> 48#include <sys/systm.h> 49#include <sys/conf.h> 50#include <sys/fcntl.h> 51#include <sys/jail.h> 52#include <sys/malloc.h> 53#include <sys/mbuf.h> 54#include <sys/time.h> 55#include <sys/priv.h> 56#include <sys/proc.h> 57#include <sys/signalvar.h> 58#include <sys/filio.h> 59#include <sys/sockio.h> 60#include <sys/ttycom.h> 61#include <sys/uio.h> 62 63#include <sys/event.h> 64#include <sys/file.h> 65#include <sys/poll.h> 66#include <sys/proc.h> 67 68#include <sys/socket.h> 69 70#include <net/if.h> 71#define BPF_INTERNAL 72#include <net/bpf.h> 73#include <net/bpf_buffer.h> 74#ifdef BPF_JITTER 75#include <net/bpf_jitter.h> 76#endif 77#include <net/bpf_zerocopy.h> 78#include <net/bpfdesc.h> 79#include <net/vnet.h> 80 81#include <netinet/in.h> 82#include <netinet/if_ether.h> 83#include <sys/kernel.h> 84#include <sys/sysctl.h> 85 86#include <net80211/ieee80211_freebsd.h> 87 88#include <security/mac/mac_framework.h> 89 90MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 91 92#if defined(DEV_BPF) || defined(NETGRAPH_BPF) 93 94#define PRINET 26 /* interruptible */ 95 96#define SIZEOF_BPF_HDR(type) \ 97 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 98 99#ifdef COMPAT_FREEBSD32 100#include <sys/mount.h> 101#include <compat/freebsd32/freebsd32.h> 102#define BPF_ALIGNMENT32 sizeof(int32_t) 103#define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1)) 104 105#ifndef BURN_BRIDGES 106/* 107 * 32-bit version of structure prepended to each packet. We use this header 108 * instead of the standard one for 32-bit streams. We mark the a stream as 109 * 32-bit the first time we see a 32-bit compat ioctl request. 110 */ 111struct bpf_hdr32 { 112 struct timeval32 bh_tstamp; /* time stamp */ 113 uint32_t bh_caplen; /* length of captured portion */ 114 uint32_t bh_datalen; /* original length of packet */ 115 uint16_t bh_hdrlen; /* length of bpf header (this struct 116 plus alignment padding) */ 117}; 118#endif 119 120struct bpf_program32 { 121 u_int bf_len; 122 uint32_t bf_insns; 123}; 124 125struct bpf_dltlist32 { 126 u_int bfl_len; 127 u_int bfl_list; 128}; 129 130#define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 131#define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 132#define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 133#define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 134#define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 135#define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 136#endif 137 138/* 139 * bpf_iflist is a list of BPF interface structures, each corresponding to a 140 * specific DLT. The same network interface might have several BPF interface 141 * structures registered by different layers in the stack (i.e., 802.11 142 * frames, ethernet frames, etc). 143 */ 144static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist; 145static struct mtx bpf_mtx; /* bpf global lock */ 146static int bpf_bpfd_cnt; 147 148static void bpf_attachd(struct bpf_d *, struct bpf_if *); 149static void bpf_detachd(struct bpf_d *); 150static void bpf_detachd_locked(struct bpf_d *); 151static void bpf_freed(struct bpf_d *); 152static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 153 struct sockaddr *, int *, struct bpf_insn *); 154static int bpf_setif(struct bpf_d *, struct ifreq *); 155static void bpf_timed_out(void *); 156static __inline void 157 bpf_wakeup(struct bpf_d *); 158static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 159 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 160 struct bintime *); 161static void reset_d(struct bpf_d *); 162static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 163static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 164static int bpf_setdlt(struct bpf_d *, u_int); 165static void filt_bpfdetach(struct knote *); 166static int filt_bpfread(struct knote *, long); 167static void bpf_drvinit(void *); 168static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 169 170SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 171int bpf_maxinsns = BPF_MAXINSNS; 172SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 173 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 174static int bpf_zerocopy_enable = 0; 175SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 176 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 177static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 178 bpf_stats_sysctl, "bpf statistics portal"); 179 180static VNET_DEFINE(int, bpf_optimize_writers) = 0; 181#define V_bpf_optimize_writers VNET(bpf_optimize_writers) 182SYSCTL_VNET_INT(_net_bpf, OID_AUTO, optimize_writers, 183 CTLFLAG_RW, &VNET_NAME(bpf_optimize_writers), 0, 184 "Do not send packets until BPF program is set"); 185 186static d_open_t bpfopen; 187static d_read_t bpfread; 188static d_write_t bpfwrite; 189static d_ioctl_t bpfioctl; 190static d_poll_t bpfpoll; 191static d_kqfilter_t bpfkqfilter; 192 193static struct cdevsw bpf_cdevsw = { 194 .d_version = D_VERSION, 195 .d_open = bpfopen, 196 .d_read = bpfread, 197 .d_write = bpfwrite, 198 .d_ioctl = bpfioctl, 199 .d_poll = bpfpoll, 200 .d_name = "bpf", 201 .d_kqfilter = bpfkqfilter, 202}; 203 204static struct filterops bpfread_filtops = { 205 .f_isfd = 1, 206 .f_detach = filt_bpfdetach, 207 .f_event = filt_bpfread, 208}; 209 210eventhandler_tag bpf_ifdetach_cookie = NULL; 211 212/* 213 * LOCKING MODEL USED BY BPF: 214 * Locks: 215 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal, 216 * some global counters and every bpf_if reference. 217 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters. 218 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields 219 * used by bpf_mtap code. 220 * 221 * Lock order: 222 * 223 * Global lock, interface lock, descriptor lock 224 * 225 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2] 226 * working model. In many places (like bpf_detachd) we start with BPF descriptor 227 * (and we need to at least rlock it to get reliable interface pointer). This 228 * gives us potential LOR. As a result, we use global lock to protect from bpf_if 229 * change in every such place. 230 * 231 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and 232 * 3) descriptor main wlock. 233 * Reading bd_bif can be protected by any of these locks, typically global lock. 234 * 235 * Changing read/write BPF filter is protected by the same three locks, 236 * the same applies for reading. 237 * 238 * Sleeping in global lock is not allowed due to bpfdetach() using it. 239 */ 240 241/* 242 * Wrapper functions for various buffering methods. If the set of buffer 243 * modes expands, we will probably want to introduce a switch data structure 244 * similar to protosw, et. 245 */ 246static void 247bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 248 u_int len) 249{ 250 251 BPFD_LOCK_ASSERT(d); 252 253 switch (d->bd_bufmode) { 254 case BPF_BUFMODE_BUFFER: 255 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 256 257 case BPF_BUFMODE_ZBUF: 258 d->bd_zcopy++; 259 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 260 261 default: 262 panic("bpf_buf_append_bytes"); 263 } 264} 265 266static void 267bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 268 u_int len) 269{ 270 271 BPFD_LOCK_ASSERT(d); 272 273 switch (d->bd_bufmode) { 274 case BPF_BUFMODE_BUFFER: 275 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 276 277 case BPF_BUFMODE_ZBUF: 278 d->bd_zcopy++; 279 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 280 281 default: 282 panic("bpf_buf_append_mbuf"); 283 } 284} 285 286/* 287 * This function gets called when the free buffer is re-assigned. 288 */ 289static void 290bpf_buf_reclaimed(struct bpf_d *d) 291{ 292 293 BPFD_LOCK_ASSERT(d); 294 295 switch (d->bd_bufmode) { 296 case BPF_BUFMODE_BUFFER: 297 return; 298 299 case BPF_BUFMODE_ZBUF: 300 bpf_zerocopy_buf_reclaimed(d); 301 return; 302 303 default: 304 panic("bpf_buf_reclaimed"); 305 } 306} 307 308/* 309 * If the buffer mechanism has a way to decide that a held buffer can be made 310 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 311 * returned if the buffer can be discarded, (0) is returned if it cannot. 312 */ 313static int 314bpf_canfreebuf(struct bpf_d *d) 315{ 316 317 BPFD_LOCK_ASSERT(d); 318 319 switch (d->bd_bufmode) { 320 case BPF_BUFMODE_ZBUF: 321 return (bpf_zerocopy_canfreebuf(d)); 322 } 323 return (0); 324} 325 326/* 327 * Allow the buffer model to indicate that the current store buffer is 328 * immutable, regardless of the appearance of space. Return (1) if the 329 * buffer is writable, and (0) if not. 330 */ 331static int 332bpf_canwritebuf(struct bpf_d *d) 333{ 334 BPFD_LOCK_ASSERT(d); 335 336 switch (d->bd_bufmode) { 337 case BPF_BUFMODE_ZBUF: 338 return (bpf_zerocopy_canwritebuf(d)); 339 } 340 return (1); 341} 342 343/* 344 * Notify buffer model that an attempt to write to the store buffer has 345 * resulted in a dropped packet, in which case the buffer may be considered 346 * full. 347 */ 348static void 349bpf_buffull(struct bpf_d *d) 350{ 351 352 BPFD_LOCK_ASSERT(d); 353 354 switch (d->bd_bufmode) { 355 case BPF_BUFMODE_ZBUF: 356 bpf_zerocopy_buffull(d); 357 break; 358 } 359} 360 361/* 362 * Notify the buffer model that a buffer has moved into the hold position. 363 */ 364void 365bpf_bufheld(struct bpf_d *d) 366{ 367 368 BPFD_LOCK_ASSERT(d); 369 370 switch (d->bd_bufmode) { 371 case BPF_BUFMODE_ZBUF: 372 bpf_zerocopy_bufheld(d); 373 break; 374 } 375} 376 377static void 378bpf_free(struct bpf_d *d) 379{ 380 381 switch (d->bd_bufmode) { 382 case BPF_BUFMODE_BUFFER: 383 return (bpf_buffer_free(d)); 384 385 case BPF_BUFMODE_ZBUF: 386 return (bpf_zerocopy_free(d)); 387 388 default: 389 panic("bpf_buf_free"); 390 } 391} 392 393static int 394bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 395{ 396 397 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 398 return (EOPNOTSUPP); 399 return (bpf_buffer_uiomove(d, buf, len, uio)); 400} 401 402static int 403bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 404{ 405 406 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 407 return (EOPNOTSUPP); 408 return (bpf_buffer_ioctl_sblen(d, i)); 409} 410 411static int 412bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 413{ 414 415 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 416 return (EOPNOTSUPP); 417 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 418} 419 420static int 421bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 422{ 423 424 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 425 return (EOPNOTSUPP); 426 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 427} 428 429static int 430bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 431{ 432 433 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 434 return (EOPNOTSUPP); 435 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 436} 437 438/* 439 * General BPF functions. 440 */ 441static int 442bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 443 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) 444{ 445 const struct ieee80211_bpf_params *p; 446 struct ether_header *eh; 447 struct mbuf *m; 448 int error; 449 int len; 450 int hlen; 451 int slen; 452 453 /* 454 * Build a sockaddr based on the data link layer type. 455 * We do this at this level because the ethernet header 456 * is copied directly into the data field of the sockaddr. 457 * In the case of SLIP, there is no header and the packet 458 * is forwarded as is. 459 * Also, we are careful to leave room at the front of the mbuf 460 * for the link level header. 461 */ 462 switch (linktype) { 463 464 case DLT_SLIP: 465 sockp->sa_family = AF_INET; 466 hlen = 0; 467 break; 468 469 case DLT_EN10MB: 470 sockp->sa_family = AF_UNSPEC; 471 /* XXX Would MAXLINKHDR be better? */ 472 hlen = ETHER_HDR_LEN; 473 break; 474 475 case DLT_FDDI: 476 sockp->sa_family = AF_IMPLINK; 477 hlen = 0; 478 break; 479 480 case DLT_RAW: 481 sockp->sa_family = AF_UNSPEC; 482 hlen = 0; 483 break; 484 485 case DLT_NULL: 486 /* 487 * null interface types require a 4 byte pseudo header which 488 * corresponds to the address family of the packet. 489 */ 490 sockp->sa_family = AF_UNSPEC; 491 hlen = 4; 492 break; 493 494 case DLT_ATM_RFC1483: 495 /* 496 * en atm driver requires 4-byte atm pseudo header. 497 * though it isn't standard, vpi:vci needs to be 498 * specified anyway. 499 */ 500 sockp->sa_family = AF_UNSPEC; 501 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 502 break; 503 504 case DLT_PPP: 505 sockp->sa_family = AF_UNSPEC; 506 hlen = 4; /* This should match PPP_HDRLEN */ 507 break; 508 509 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 510 sockp->sa_family = AF_IEEE80211; 511 hlen = 0; 512 break; 513 514 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 515 sockp->sa_family = AF_IEEE80211; 516 sockp->sa_len = 12; /* XXX != 0 */ 517 hlen = sizeof(struct ieee80211_bpf_params); 518 break; 519 520 default: 521 return (EIO); 522 } 523 524 len = uio->uio_resid; 525 if (len < hlen || len - hlen > ifp->if_mtu) 526 return (EMSGSIZE); 527 528 m = m_get2(M_WAITOK, MT_DATA, M_PKTHDR, len); 529 if (m == NULL) 530 return (EIO); 531 m->m_pkthdr.len = m->m_len = len; 532 *mp = m; 533 534 error = uiomove(mtod(m, u_char *), len, uio); 535 if (error) 536 goto bad; 537 538 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 539 if (slen == 0) { 540 error = EPERM; 541 goto bad; 542 } 543 544 /* Check for multicast destination */ 545 switch (linktype) { 546 case DLT_EN10MB: 547 eh = mtod(m, struct ether_header *); 548 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 549 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 550 ETHER_ADDR_LEN) == 0) 551 m->m_flags |= M_BCAST; 552 else 553 m->m_flags |= M_MCAST; 554 } 555 break; 556 } 557 558 /* 559 * Make room for link header, and copy it to sockaddr 560 */ 561 if (hlen != 0) { 562 if (sockp->sa_family == AF_IEEE80211) { 563 /* 564 * Collect true length from the parameter header 565 * NB: sockp is known to be zero'd so if we do a 566 * short copy unspecified parameters will be 567 * zero. 568 * NB: packet may not be aligned after stripping 569 * bpf params 570 * XXX check ibp_vers 571 */ 572 p = mtod(m, const struct ieee80211_bpf_params *); 573 hlen = p->ibp_len; 574 if (hlen > sizeof(sockp->sa_data)) { 575 error = EINVAL; 576 goto bad; 577 } 578 } 579 bcopy(m->m_data, sockp->sa_data, hlen); 580 } 581 *hdrlen = hlen; 582 583 return (0); 584bad: 585 m_freem(m); 586 return (error); 587} 588 589/* 590 * Attach file to the bpf interface, i.e. make d listen on bp. 591 */ 592static void 593bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 594{ 595 int op_w; 596 597 BPF_LOCK_ASSERT(); 598 599 /* 600 * Save sysctl value to protect from sysctl change 601 * between reads 602 */ 603 op_w = V_bpf_optimize_writers; 604 605 if (d->bd_bif != NULL) 606 bpf_detachd_locked(d); 607 /* 608 * Point d at bp, and add d to the interface's list. 609 * Since there are many applicaiotns using BPF for 610 * sending raw packets only (dhcpd, cdpd are good examples) 611 * we can delay adding d to the list of active listeners until 612 * some filter is configured. 613 */ 614 615 BPFIF_WLOCK(bp); 616 BPFD_LOCK(d); 617 618 d->bd_bif = bp; 619 620 if (op_w != 0) { 621 /* Add to writers-only list */ 622 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 623 /* 624 * We decrement bd_writer on every filter set operation. 625 * First BIOCSETF is done by pcap_open_live() to set up 626 * snap length. After that appliation usually sets its own filter 627 */ 628 d->bd_writer = 2; 629 } else 630 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 631 632 BPFD_UNLOCK(d); 633 BPFIF_WUNLOCK(bp); 634 635 bpf_bpfd_cnt++; 636 637 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 638 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 639 640 if (op_w == 0) 641 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 642} 643 644/* 645 * Add d to the list of active bp filters. 646 * Reuqires bpf_attachd() to be called before 647 */ 648static void 649bpf_upgraded(struct bpf_d *d) 650{ 651 struct bpf_if *bp; 652 653 BPF_LOCK_ASSERT(); 654 655 bp = d->bd_bif; 656 657 /* 658 * Filter can be set several times without specifying interface. 659 * Mark d as reader and exit. 660 */ 661 if (bp == NULL) { 662 BPFD_LOCK(d); 663 d->bd_writer = 0; 664 BPFD_UNLOCK(d); 665 return; 666 } 667 668 BPFIF_WLOCK(bp); 669 BPFD_LOCK(d); 670 671 /* Remove from writers-only list */ 672 LIST_REMOVE(d, bd_next); 673 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 674 /* Mark d as reader */ 675 d->bd_writer = 0; 676 677 BPFD_UNLOCK(d); 678 BPFIF_WUNLOCK(bp); 679 680 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid); 681 682 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 683} 684 685/* 686 * Detach a file from its interface. 687 */ 688static void 689bpf_detachd(struct bpf_d *d) 690{ 691 BPF_LOCK(); 692 bpf_detachd_locked(d); 693 BPF_UNLOCK(); 694} 695 696static void 697bpf_detachd_locked(struct bpf_d *d) 698{ 699 int error; 700 struct bpf_if *bp; 701 struct ifnet *ifp; 702 703 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 704 705 BPF_LOCK_ASSERT(); 706 707 /* Check if descriptor is attached */ 708 if ((bp = d->bd_bif) == NULL) 709 return; 710 711 BPFIF_WLOCK(bp); 712 BPFD_LOCK(d); 713 714 /* Save bd_writer value */ 715 error = d->bd_writer; 716 717 /* 718 * Remove d from the interface's descriptor list. 719 */ 720 LIST_REMOVE(d, bd_next); 721 722 ifp = bp->bif_ifp; 723 d->bd_bif = NULL; 724 BPFD_UNLOCK(d); 725 BPFIF_WUNLOCK(bp); 726 727 bpf_bpfd_cnt--; 728 729 /* Call event handler iff d is attached */ 730 if (error == 0) 731 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 732 733 /* 734 * Check if this descriptor had requested promiscuous mode. 735 * If so, turn it off. 736 */ 737 if (d->bd_promisc) { 738 d->bd_promisc = 0; 739 CURVNET_SET(ifp->if_vnet); 740 error = ifpromisc(ifp, 0); 741 CURVNET_RESTORE(); 742 if (error != 0 && error != ENXIO) { 743 /* 744 * ENXIO can happen if a pccard is unplugged 745 * Something is really wrong if we were able to put 746 * the driver into promiscuous mode, but can't 747 * take it out. 748 */ 749 if_printf(bp->bif_ifp, 750 "bpf_detach: ifpromisc failed (%d)\n", error); 751 } 752 } 753} 754 755/* 756 * Close the descriptor by detaching it from its interface, 757 * deallocating its buffers, and marking it free. 758 */ 759static void 760bpf_dtor(void *data) 761{ 762 struct bpf_d *d = data; 763 764 BPFD_LOCK(d); 765 if (d->bd_state == BPF_WAITING) 766 callout_stop(&d->bd_callout); 767 d->bd_state = BPF_IDLE; 768 BPFD_UNLOCK(d); 769 funsetown(&d->bd_sigio); 770 bpf_detachd(d); 771#ifdef MAC 772 mac_bpfdesc_destroy(d); 773#endif /* MAC */ 774 seldrain(&d->bd_sel); 775 knlist_destroy(&d->bd_sel.si_note); 776 callout_drain(&d->bd_callout); 777 bpf_freed(d); 778 free(d, M_BPF); 779} 780 781/* 782 * Open ethernet device. Returns ENXIO for illegal minor device number, 783 * EBUSY if file is open by another process. 784 */ 785/* ARGSUSED */ 786static int 787bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 788{ 789 struct bpf_d *d; 790 int error, size; 791 792 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 793 error = devfs_set_cdevpriv(d, bpf_dtor); 794 if (error != 0) { 795 free(d, M_BPF); 796 return (error); 797 } 798 799 /* 800 * For historical reasons, perform a one-time initialization call to 801 * the buffer routines, even though we're not yet committed to a 802 * particular buffer method. 803 */ 804 bpf_buffer_init(d); 805 d->bd_hbuf_in_use = 0; 806 d->bd_bufmode = BPF_BUFMODE_BUFFER; 807 d->bd_sig = SIGIO; 808 d->bd_direction = BPF_D_INOUT; 809 BPF_PID_REFRESH(d, td); 810#ifdef MAC 811 mac_bpfdesc_init(d); 812 mac_bpfdesc_create(td->td_ucred, d); 813#endif 814 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 815 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 816 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 817 818 /* Allocate default buffers */ 819 size = d->bd_bufsize; 820 bpf_buffer_ioctl_sblen(d, &size); 821 822 return (0); 823} 824 825/* 826 * bpfread - read next chunk of packets from buffers 827 */ 828static int 829bpfread(struct cdev *dev, struct uio *uio, int ioflag) 830{ 831 struct bpf_d *d; 832 int error; 833 int non_block; 834 int timed_out; 835 836 error = devfs_get_cdevpriv((void **)&d); 837 if (error != 0) 838 return (error); 839 840 /* 841 * Restrict application to use a buffer the same size as 842 * as kernel buffers. 843 */ 844 if (uio->uio_resid != d->bd_bufsize) 845 return (EINVAL); 846 847 non_block = ((ioflag & O_NONBLOCK) != 0); 848 849 BPFD_LOCK(d); 850 BPF_PID_REFRESH_CUR(d); 851 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 852 BPFD_UNLOCK(d); 853 return (EOPNOTSUPP); 854 } 855 if (d->bd_state == BPF_WAITING) 856 callout_stop(&d->bd_callout); 857 timed_out = (d->bd_state == BPF_TIMED_OUT); 858 d->bd_state = BPF_IDLE; 859 while (d->bd_hbuf_in_use) 860 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 861 PRINET|PCATCH, "bd_hbuf", 0); 862 /* 863 * If the hold buffer is empty, then do a timed sleep, which 864 * ends when the timeout expires or when enough packets 865 * have arrived to fill the store buffer. 866 */ 867 while (d->bd_hbuf == NULL) { 868 if (d->bd_slen != 0) { 869 /* 870 * A packet(s) either arrived since the previous 871 * read or arrived while we were asleep. 872 */ 873 if (d->bd_immediate || non_block || timed_out) { 874 /* 875 * Rotate the buffers and return what's here 876 * if we are in immediate mode, non-blocking 877 * flag is set, or this descriptor timed out. 878 */ 879 ROTATE_BUFFERS(d); 880 break; 881 } 882 } 883 884 /* 885 * No data is available, check to see if the bpf device 886 * is still pointed at a real interface. If not, return 887 * ENXIO so that the userland process knows to rebind 888 * it before using it again. 889 */ 890 if (d->bd_bif == NULL) { 891 BPFD_UNLOCK(d); 892 return (ENXIO); 893 } 894 895 if (non_block) { 896 BPFD_UNLOCK(d); 897 return (EWOULDBLOCK); 898 } 899 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 900 "bpf", d->bd_rtout); 901 if (error == EINTR || error == ERESTART) { 902 BPFD_UNLOCK(d); 903 return (error); 904 } 905 if (error == EWOULDBLOCK) { 906 /* 907 * On a timeout, return what's in the buffer, 908 * which may be nothing. If there is something 909 * in the store buffer, we can rotate the buffers. 910 */ 911 if (d->bd_hbuf) 912 /* 913 * We filled up the buffer in between 914 * getting the timeout and arriving 915 * here, so we don't need to rotate. 916 */ 917 break; 918 919 if (d->bd_slen == 0) { 920 BPFD_UNLOCK(d); 921 return (0); 922 } 923 ROTATE_BUFFERS(d); 924 break; 925 } 926 } 927 /* 928 * At this point, we know we have something in the hold slot. 929 */ 930 d->bd_hbuf_in_use = 1; 931 BPFD_UNLOCK(d); 932 933 /* 934 * Move data from hold buffer into user space. 935 * We know the entire buffer is transferred since 936 * we checked above that the read buffer is bpf_bufsize bytes. 937 * 938 * We do not have to worry about simultaneous reads because 939 * we waited for sole access to the hold buffer above. 940 */ 941 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 942 943 BPFD_LOCK(d); 944 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 945 d->bd_fbuf = d->bd_hbuf; 946 d->bd_hbuf = NULL; 947 d->bd_hlen = 0; 948 bpf_buf_reclaimed(d); 949 d->bd_hbuf_in_use = 0; 950 wakeup(&d->bd_hbuf_in_use); 951 BPFD_UNLOCK(d); 952 953 return (error); 954} 955 956/* 957 * If there are processes sleeping on this descriptor, wake them up. 958 */ 959static __inline void 960bpf_wakeup(struct bpf_d *d) 961{ 962 963 BPFD_LOCK_ASSERT(d); 964 if (d->bd_state == BPF_WAITING) { 965 callout_stop(&d->bd_callout); 966 d->bd_state = BPF_IDLE; 967 } 968 wakeup(d); 969 if (d->bd_async && d->bd_sig && d->bd_sigio) 970 pgsigio(&d->bd_sigio, d->bd_sig, 0); 971 972 selwakeuppri(&d->bd_sel, PRINET); 973 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 974} 975 976static void 977bpf_timed_out(void *arg) 978{ 979 struct bpf_d *d = (struct bpf_d *)arg; 980 981 BPFD_LOCK_ASSERT(d); 982 983 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) 984 return; 985 if (d->bd_state == BPF_WAITING) { 986 d->bd_state = BPF_TIMED_OUT; 987 if (d->bd_slen != 0) 988 bpf_wakeup(d); 989 } 990} 991 992static int 993bpf_ready(struct bpf_d *d) 994{ 995 996 BPFD_LOCK_ASSERT(d); 997 998 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 999 return (1); 1000 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1001 d->bd_slen != 0) 1002 return (1); 1003 return (0); 1004} 1005 1006static int 1007bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1008{ 1009 struct bpf_d *d; 1010 struct ifnet *ifp; 1011 struct mbuf *m, *mc; 1012 struct sockaddr dst; 1013 int error, hlen; 1014 1015 error = devfs_get_cdevpriv((void **)&d); 1016 if (error != 0) 1017 return (error); 1018 1019 BPF_PID_REFRESH_CUR(d); 1020 d->bd_wcount++; 1021 /* XXX: locking required */ 1022 if (d->bd_bif == NULL) { 1023 d->bd_wdcount++; 1024 return (ENXIO); 1025 } 1026 1027 ifp = d->bd_bif->bif_ifp; 1028 1029 if ((ifp->if_flags & IFF_UP) == 0) { 1030 d->bd_wdcount++; 1031 return (ENETDOWN); 1032 } 1033 1034 if (uio->uio_resid == 0) { 1035 d->bd_wdcount++; 1036 return (0); 1037 } 1038 1039 bzero(&dst, sizeof(dst)); 1040 m = NULL; 1041 hlen = 0; 1042 /* XXX: bpf_movein() can sleep */ 1043 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 1044 &m, &dst, &hlen, d->bd_wfilter); 1045 if (error) { 1046 d->bd_wdcount++; 1047 return (error); 1048 } 1049 d->bd_wfcount++; 1050 if (d->bd_hdrcmplt) 1051 dst.sa_family = pseudo_AF_HDRCMPLT; 1052 1053 if (d->bd_feedback) { 1054 mc = m_dup(m, M_NOWAIT); 1055 if (mc != NULL) 1056 mc->m_pkthdr.rcvif = ifp; 1057 /* Set M_PROMISC for outgoing packets to be discarded. */ 1058 if (d->bd_direction == BPF_D_INOUT) 1059 m->m_flags |= M_PROMISC; 1060 } else 1061 mc = NULL; 1062 1063 m->m_pkthdr.len -= hlen; 1064 m->m_len -= hlen; 1065 m->m_data += hlen; /* XXX */ 1066 1067 CURVNET_SET(ifp->if_vnet); 1068#ifdef MAC 1069 BPFD_LOCK(d); 1070 mac_bpfdesc_create_mbuf(d, m); 1071 if (mc != NULL) 1072 mac_bpfdesc_create_mbuf(d, mc); 1073 BPFD_UNLOCK(d); 1074#endif 1075 1076 error = (*ifp->if_output)(ifp, m, &dst, NULL); 1077 if (error) 1078 d->bd_wdcount++; 1079 1080 if (mc != NULL) { 1081 if (error == 0) 1082 (*ifp->if_input)(ifp, mc); 1083 else 1084 m_freem(mc); 1085 } 1086 CURVNET_RESTORE(); 1087 1088 return (error); 1089} 1090 1091/* 1092 * Reset a descriptor by flushing its packet buffer and clearing the receive 1093 * and drop counts. This is doable for kernel-only buffers, but with 1094 * zero-copy buffers, we can't write to (or rotate) buffers that are 1095 * currently owned by userspace. It would be nice if we could encapsulate 1096 * this logic in the buffer code rather than here. 1097 */ 1098static void 1099reset_d(struct bpf_d *d) 1100{ 1101 1102 BPFD_LOCK_ASSERT(d); 1103 1104 while (d->bd_hbuf_in_use) 1105 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1106 "bd_hbuf", 0); 1107 if ((d->bd_hbuf != NULL) && 1108 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1109 /* Free the hold buffer. */ 1110 d->bd_fbuf = d->bd_hbuf; 1111 d->bd_hbuf = NULL; 1112 d->bd_hlen = 0; 1113 bpf_buf_reclaimed(d); 1114 } 1115 if (bpf_canwritebuf(d)) 1116 d->bd_slen = 0; 1117 d->bd_rcount = 0; 1118 d->bd_dcount = 0; 1119 d->bd_fcount = 0; 1120 d->bd_wcount = 0; 1121 d->bd_wfcount = 0; 1122 d->bd_wdcount = 0; 1123 d->bd_zcopy = 0; 1124} 1125 1126/* 1127 * FIONREAD Check for read packet available. 1128 * SIOCGIFADDR Get interface address - convenient hook to driver. 1129 * BIOCGBLEN Get buffer len [for read()]. 1130 * BIOCSETF Set read filter. 1131 * BIOCSETFNR Set read filter without resetting descriptor. 1132 * BIOCSETWF Set write filter. 1133 * BIOCFLUSH Flush read packet buffer. 1134 * BIOCPROMISC Put interface into promiscuous mode. 1135 * BIOCGDLT Get link layer type. 1136 * BIOCGETIF Get interface name. 1137 * BIOCSETIF Set interface. 1138 * BIOCSRTIMEOUT Set read timeout. 1139 * BIOCGRTIMEOUT Get read timeout. 1140 * BIOCGSTATS Get packet stats. 1141 * BIOCIMMEDIATE Set immediate mode. 1142 * BIOCVERSION Get filter language version. 1143 * BIOCGHDRCMPLT Get "header already complete" flag 1144 * BIOCSHDRCMPLT Set "header already complete" flag 1145 * BIOCGDIRECTION Get packet direction flag 1146 * BIOCSDIRECTION Set packet direction flag 1147 * BIOCGTSTAMP Get time stamp format and resolution. 1148 * BIOCSTSTAMP Set time stamp format and resolution. 1149 * BIOCLOCK Set "locked" flag 1150 * BIOCFEEDBACK Set packet feedback mode. 1151 * BIOCSETZBUF Set current zero-copy buffer locations. 1152 * BIOCGETZMAX Get maximum zero-copy buffer size. 1153 * BIOCROTZBUF Force rotation of zero-copy buffer 1154 * BIOCSETBUFMODE Set buffer mode. 1155 * BIOCGETBUFMODE Get current buffer mode. 1156 */ 1157/* ARGSUSED */ 1158static int 1159bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1160 struct thread *td) 1161{ 1162 struct bpf_d *d; 1163 int error; 1164 1165 error = devfs_get_cdevpriv((void **)&d); 1166 if (error != 0) 1167 return (error); 1168 1169 /* 1170 * Refresh PID associated with this descriptor. 1171 */ 1172 BPFD_LOCK(d); 1173 BPF_PID_REFRESH(d, td); 1174 if (d->bd_state == BPF_WAITING) 1175 callout_stop(&d->bd_callout); 1176 d->bd_state = BPF_IDLE; 1177 BPFD_UNLOCK(d); 1178 1179 if (d->bd_locked == 1) { 1180 switch (cmd) { 1181 case BIOCGBLEN: 1182 case BIOCFLUSH: 1183 case BIOCGDLT: 1184 case BIOCGDLTLIST: 1185#ifdef COMPAT_FREEBSD32 1186 case BIOCGDLTLIST32: 1187#endif 1188 case BIOCGETIF: 1189 case BIOCGRTIMEOUT: 1190#if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1191 case BIOCGRTIMEOUT32: 1192#endif 1193 case BIOCGSTATS: 1194 case BIOCVERSION: 1195 case BIOCGRSIG: 1196 case BIOCGHDRCMPLT: 1197 case BIOCSTSTAMP: 1198 case BIOCFEEDBACK: 1199 case FIONREAD: 1200 case BIOCLOCK: 1201 case BIOCSRTIMEOUT: 1202#if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1203 case BIOCSRTIMEOUT32: 1204#endif 1205 case BIOCIMMEDIATE: 1206 case TIOCGPGRP: 1207 case BIOCROTZBUF: 1208 break; 1209 default: 1210 return (EPERM); 1211 } 1212 } 1213#ifdef COMPAT_FREEBSD32 1214 /* 1215 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1216 * that it will get 32-bit packet headers. 1217 */ 1218 switch (cmd) { 1219 case BIOCSETF32: 1220 case BIOCSETFNR32: 1221 case BIOCSETWF32: 1222 case BIOCGDLTLIST32: 1223 case BIOCGRTIMEOUT32: 1224 case BIOCSRTIMEOUT32: 1225 BPFD_LOCK(d); 1226 d->bd_compat32 = 1; 1227 BPFD_UNLOCK(d); 1228 } 1229#endif 1230 1231 CURVNET_SET(TD_TO_VNET(td)); 1232 switch (cmd) { 1233 1234 default: 1235 error = EINVAL; 1236 break; 1237 1238 /* 1239 * Check for read packet available. 1240 */ 1241 case FIONREAD: 1242 { 1243 int n; 1244 1245 BPFD_LOCK(d); 1246 n = d->bd_slen; 1247 while (d->bd_hbuf_in_use) 1248 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1249 PRINET, "bd_hbuf", 0); 1250 if (d->bd_hbuf) 1251 n += d->bd_hlen; 1252 BPFD_UNLOCK(d); 1253 1254 *(int *)addr = n; 1255 break; 1256 } 1257 1258 case SIOCGIFADDR: 1259 { 1260 struct ifnet *ifp; 1261 1262 if (d->bd_bif == NULL) 1263 error = EINVAL; 1264 else { 1265 ifp = d->bd_bif->bif_ifp; 1266 error = (*ifp->if_ioctl)(ifp, cmd, addr); 1267 } 1268 break; 1269 } 1270 1271 /* 1272 * Get buffer len [for read()]. 1273 */ 1274 case BIOCGBLEN: 1275 BPFD_LOCK(d); 1276 *(u_int *)addr = d->bd_bufsize; 1277 BPFD_UNLOCK(d); 1278 break; 1279 1280 /* 1281 * Set buffer length. 1282 */ 1283 case BIOCSBLEN: 1284 error = bpf_ioctl_sblen(d, (u_int *)addr); 1285 break; 1286 1287 /* 1288 * Set link layer read filter. 1289 */ 1290 case BIOCSETF: 1291 case BIOCSETFNR: 1292 case BIOCSETWF: 1293#ifdef COMPAT_FREEBSD32 1294 case BIOCSETF32: 1295 case BIOCSETFNR32: 1296 case BIOCSETWF32: 1297#endif 1298 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1299 break; 1300 1301 /* 1302 * Flush read packet buffer. 1303 */ 1304 case BIOCFLUSH: 1305 BPFD_LOCK(d); 1306 reset_d(d); 1307 BPFD_UNLOCK(d); 1308 break; 1309 1310 /* 1311 * Put interface into promiscuous mode. 1312 */ 1313 case BIOCPROMISC: 1314 if (d->bd_bif == NULL) { 1315 /* 1316 * No interface attached yet. 1317 */ 1318 error = EINVAL; 1319 break; 1320 } 1321 if (d->bd_promisc == 0) { 1322 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1323 if (error == 0) 1324 d->bd_promisc = 1; 1325 } 1326 break; 1327 1328 /* 1329 * Get current data link type. 1330 */ 1331 case BIOCGDLT: 1332 BPF_LOCK(); 1333 if (d->bd_bif == NULL) 1334 error = EINVAL; 1335 else 1336 *(u_int *)addr = d->bd_bif->bif_dlt; 1337 BPF_UNLOCK(); 1338 break; 1339 1340 /* 1341 * Get a list of supported data link types. 1342 */ 1343#ifdef COMPAT_FREEBSD32 1344 case BIOCGDLTLIST32: 1345 { 1346 struct bpf_dltlist32 *list32; 1347 struct bpf_dltlist dltlist; 1348 1349 list32 = (struct bpf_dltlist32 *)addr; 1350 dltlist.bfl_len = list32->bfl_len; 1351 dltlist.bfl_list = PTRIN(list32->bfl_list); 1352 BPF_LOCK(); 1353 if (d->bd_bif == NULL) 1354 error = EINVAL; 1355 else { 1356 error = bpf_getdltlist(d, &dltlist); 1357 if (error == 0) 1358 list32->bfl_len = dltlist.bfl_len; 1359 } 1360 BPF_UNLOCK(); 1361 break; 1362 } 1363#endif 1364 1365 case BIOCGDLTLIST: 1366 BPF_LOCK(); 1367 if (d->bd_bif == NULL) 1368 error = EINVAL; 1369 else 1370 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1371 BPF_UNLOCK(); 1372 break; 1373 1374 /* 1375 * Set data link type. 1376 */ 1377 case BIOCSDLT: 1378 BPF_LOCK(); 1379 if (d->bd_bif == NULL) 1380 error = EINVAL; 1381 else 1382 error = bpf_setdlt(d, *(u_int *)addr); 1383 BPF_UNLOCK(); 1384 break; 1385 1386 /* 1387 * Get interface name. 1388 */ 1389 case BIOCGETIF: 1390 BPF_LOCK(); 1391 if (d->bd_bif == NULL) 1392 error = EINVAL; 1393 else { 1394 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1395 struct ifreq *const ifr = (struct ifreq *)addr; 1396 1397 strlcpy(ifr->ifr_name, ifp->if_xname, 1398 sizeof(ifr->ifr_name)); 1399 } 1400 BPF_UNLOCK(); 1401 break; 1402 1403 /* 1404 * Set interface. 1405 */ 1406 case BIOCSETIF: 1407 BPF_LOCK(); 1408 error = bpf_setif(d, (struct ifreq *)addr); 1409 BPF_UNLOCK(); 1410 break; 1411 1412 /* 1413 * Set read timeout. 1414 */ 1415 case BIOCSRTIMEOUT: 1416#if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1417 case BIOCSRTIMEOUT32: 1418#endif 1419 { 1420 struct timeval *tv = (struct timeval *)addr; 1421#if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1422 struct timeval32 *tv32; 1423 struct timeval tv64; 1424 1425 if (cmd == BIOCSRTIMEOUT32) { 1426 tv32 = (struct timeval32 *)addr; 1427 tv = &tv64; 1428 tv->tv_sec = tv32->tv_sec; 1429 tv->tv_usec = tv32->tv_usec; 1430 } else 1431#endif 1432 tv = (struct timeval *)addr; 1433 1434 /* 1435 * Subtract 1 tick from tvtohz() since this isn't 1436 * a one-shot timer. 1437 */ 1438 if ((error = itimerfix(tv)) == 0) 1439 d->bd_rtout = tvtohz(tv) - 1; 1440 break; 1441 } 1442 1443 /* 1444 * Get read timeout. 1445 */ 1446 case BIOCGRTIMEOUT: 1447#if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1448 case BIOCGRTIMEOUT32: 1449#endif 1450 { 1451 struct timeval *tv; 1452#if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1453 struct timeval32 *tv32; 1454 struct timeval tv64; 1455 1456 if (cmd == BIOCGRTIMEOUT32) 1457 tv = &tv64; 1458 else 1459#endif 1460 tv = (struct timeval *)addr; 1461 1462 tv->tv_sec = d->bd_rtout / hz; 1463 tv->tv_usec = (d->bd_rtout % hz) * tick; 1464#if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1465 if (cmd == BIOCGRTIMEOUT32) { 1466 tv32 = (struct timeval32 *)addr; 1467 tv32->tv_sec = tv->tv_sec; 1468 tv32->tv_usec = tv->tv_usec; 1469 } 1470#endif 1471 1472 break; 1473 } 1474 1475 /* 1476 * Get packet stats. 1477 */ 1478 case BIOCGSTATS: 1479 { 1480 struct bpf_stat *bs = (struct bpf_stat *)addr; 1481 1482 /* XXXCSJP overflow */ 1483 bs->bs_recv = d->bd_rcount; 1484 bs->bs_drop = d->bd_dcount; 1485 break; 1486 } 1487 1488 /* 1489 * Set immediate mode. 1490 */ 1491 case BIOCIMMEDIATE: 1492 BPFD_LOCK(d); 1493 d->bd_immediate = *(u_int *)addr; 1494 BPFD_UNLOCK(d); 1495 break; 1496 1497 case BIOCVERSION: 1498 { 1499 struct bpf_version *bv = (struct bpf_version *)addr; 1500 1501 bv->bv_major = BPF_MAJOR_VERSION; 1502 bv->bv_minor = BPF_MINOR_VERSION; 1503 break; 1504 } 1505 1506 /* 1507 * Get "header already complete" flag 1508 */ 1509 case BIOCGHDRCMPLT: 1510 BPFD_LOCK(d); 1511 *(u_int *)addr = d->bd_hdrcmplt; 1512 BPFD_UNLOCK(d); 1513 break; 1514 1515 /* 1516 * Set "header already complete" flag 1517 */ 1518 case BIOCSHDRCMPLT: 1519 BPFD_LOCK(d); 1520 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1521 BPFD_UNLOCK(d); 1522 break; 1523 1524 /* 1525 * Get packet direction flag 1526 */ 1527 case BIOCGDIRECTION: 1528 BPFD_LOCK(d); 1529 *(u_int *)addr = d->bd_direction; 1530 BPFD_UNLOCK(d); 1531 break; 1532 1533 /* 1534 * Set packet direction flag 1535 */ 1536 case BIOCSDIRECTION: 1537 { 1538 u_int direction; 1539 1540 direction = *(u_int *)addr; 1541 switch (direction) { 1542 case BPF_D_IN: 1543 case BPF_D_INOUT: 1544 case BPF_D_OUT: 1545 BPFD_LOCK(d); 1546 d->bd_direction = direction; 1547 BPFD_UNLOCK(d); 1548 break; 1549 default: 1550 error = EINVAL; 1551 } 1552 } 1553 break; 1554 1555 /* 1556 * Get packet timestamp format and resolution. 1557 */ 1558 case BIOCGTSTAMP: 1559 BPFD_LOCK(d); 1560 *(u_int *)addr = d->bd_tstamp; 1561 BPFD_UNLOCK(d); 1562 break; 1563 1564 /* 1565 * Set packet timestamp format and resolution. 1566 */ 1567 case BIOCSTSTAMP: 1568 { 1569 u_int func; 1570 1571 func = *(u_int *)addr; 1572 if (BPF_T_VALID(func)) 1573 d->bd_tstamp = func; 1574 else 1575 error = EINVAL; 1576 } 1577 break; 1578 1579 case BIOCFEEDBACK: 1580 BPFD_LOCK(d); 1581 d->bd_feedback = *(u_int *)addr; 1582 BPFD_UNLOCK(d); 1583 break; 1584 1585 case BIOCLOCK: 1586 BPFD_LOCK(d); 1587 d->bd_locked = 1; 1588 BPFD_UNLOCK(d); 1589 break; 1590 1591 case FIONBIO: /* Non-blocking I/O */ 1592 break; 1593 1594 case FIOASYNC: /* Send signal on receive packets */ 1595 BPFD_LOCK(d); 1596 d->bd_async = *(int *)addr; 1597 BPFD_UNLOCK(d); 1598 break; 1599 1600 case FIOSETOWN: 1601 /* 1602 * XXX: Add some sort of locking here? 1603 * fsetown() can sleep. 1604 */ 1605 error = fsetown(*(int *)addr, &d->bd_sigio); 1606 break; 1607 1608 case FIOGETOWN: 1609 BPFD_LOCK(d); 1610 *(int *)addr = fgetown(&d->bd_sigio); 1611 BPFD_UNLOCK(d); 1612 break; 1613 1614 /* This is deprecated, FIOSETOWN should be used instead. */ 1615 case TIOCSPGRP: 1616 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1617 break; 1618 1619 /* This is deprecated, FIOGETOWN should be used instead. */ 1620 case TIOCGPGRP: 1621 *(int *)addr = -fgetown(&d->bd_sigio); 1622 break; 1623 1624 case BIOCSRSIG: /* Set receive signal */ 1625 { 1626 u_int sig; 1627 1628 sig = *(u_int *)addr; 1629 1630 if (sig >= NSIG) 1631 error = EINVAL; 1632 else { 1633 BPFD_LOCK(d); 1634 d->bd_sig = sig; 1635 BPFD_UNLOCK(d); 1636 } 1637 break; 1638 } 1639 case BIOCGRSIG: 1640 BPFD_LOCK(d); 1641 *(u_int *)addr = d->bd_sig; 1642 BPFD_UNLOCK(d); 1643 break; 1644 1645 case BIOCGETBUFMODE: 1646 BPFD_LOCK(d); 1647 *(u_int *)addr = d->bd_bufmode; 1648 BPFD_UNLOCK(d); 1649 break; 1650 1651 case BIOCSETBUFMODE: 1652 /* 1653 * Allow the buffering mode to be changed as long as we 1654 * haven't yet committed to a particular mode. Our 1655 * definition of commitment, for now, is whether or not a 1656 * buffer has been allocated or an interface attached, since 1657 * that's the point where things get tricky. 1658 */ 1659 switch (*(u_int *)addr) { 1660 case BPF_BUFMODE_BUFFER: 1661 break; 1662 1663 case BPF_BUFMODE_ZBUF: 1664 if (bpf_zerocopy_enable) 1665 break; 1666 /* FALLSTHROUGH */ 1667 1668 default: 1669 CURVNET_RESTORE(); 1670 return (EINVAL); 1671 } 1672 1673 BPFD_LOCK(d); 1674 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1675 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1676 BPFD_UNLOCK(d); 1677 CURVNET_RESTORE(); 1678 return (EBUSY); 1679 } 1680 d->bd_bufmode = *(u_int *)addr; 1681 BPFD_UNLOCK(d); 1682 break; 1683 1684 case BIOCGETZMAX: 1685 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1686 break; 1687 1688 case BIOCSETZBUF: 1689 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1690 break; 1691 1692 case BIOCROTZBUF: 1693 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1694 break; 1695 } 1696 CURVNET_RESTORE(); 1697 return (error); 1698} 1699 1700/* 1701 * Set d's packet filter program to fp. If this file already has a filter, 1702 * free it and replace it. Returns EINVAL for bogus requests. 1703 * 1704 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls 1705 * since reading d->bd_bif can't be protected by d or interface lock due to 1706 * lock order. 1707 * 1708 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses 1709 * interface read lock to read all filers. 1710 * 1711 */ 1712static int 1713bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1714{ 1715#ifdef COMPAT_FREEBSD32 1716 struct bpf_program fp_swab; 1717 struct bpf_program32 *fp32; 1718#endif 1719 struct bpf_insn *fcode, *old; 1720#ifdef BPF_JITTER 1721 bpf_jit_filter *jfunc, *ofunc; 1722#endif 1723 size_t size; 1724 u_int flen; 1725 int need_upgrade; 1726 1727#ifdef COMPAT_FREEBSD32 1728 switch (cmd) { 1729 case BIOCSETF32: 1730 case BIOCSETWF32: 1731 case BIOCSETFNR32: 1732 fp32 = (struct bpf_program32 *)fp; 1733 fp_swab.bf_len = fp32->bf_len; 1734 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1735 fp = &fp_swab; 1736 switch (cmd) { 1737 case BIOCSETF32: 1738 cmd = BIOCSETF; 1739 break; 1740 case BIOCSETWF32: 1741 cmd = BIOCSETWF; 1742 break; 1743 } 1744 break; 1745 } 1746#endif 1747 1748 fcode = NULL; 1749#ifdef BPF_JITTER 1750 jfunc = ofunc = NULL; 1751#endif 1752 need_upgrade = 0; 1753 1754 /* 1755 * Check new filter validness before acquiring any locks. 1756 * Allocate memory for new filter, if needed. 1757 */ 1758 flen = fp->bf_len; 1759 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1760 return (EINVAL); 1761 size = flen * sizeof(*fp->bf_insns); 1762 if (size > 0) { 1763 /* We're setting up new filter. Copy and check actual data. */ 1764 fcode = malloc(size, M_BPF, M_WAITOK); 1765 if (copyin(fp->bf_insns, fcode, size) != 0 || 1766 !bpf_validate(fcode, flen)) { 1767 free(fcode, M_BPF); 1768 return (EINVAL); 1769 } 1770#ifdef BPF_JITTER 1771 /* Filter is copied inside fcode and is perfectly valid. */ 1772 jfunc = bpf_jitter(fcode, flen); 1773#endif 1774 } 1775 1776 BPF_LOCK(); 1777 1778 /* 1779 * Set up new filter. 1780 * Protect filter change by interface lock. 1781 * Additionally, we are protected by global lock here. 1782 */ 1783 if (d->bd_bif != NULL) 1784 BPFIF_WLOCK(d->bd_bif); 1785 BPFD_LOCK(d); 1786 if (cmd == BIOCSETWF) { 1787 old = d->bd_wfilter; 1788 d->bd_wfilter = fcode; 1789 } else { 1790 old = d->bd_rfilter; 1791 d->bd_rfilter = fcode; 1792#ifdef BPF_JITTER 1793 ofunc = d->bd_bfilter; 1794 d->bd_bfilter = jfunc; 1795#endif 1796 if (cmd == BIOCSETF) 1797 reset_d(d); 1798 1799 if (fcode != NULL) { 1800 /* 1801 * Do not require upgrade by first BIOCSETF 1802 * (used to set snaplen) by pcap_open_live(). 1803 */ 1804 if (d->bd_writer != 0 && --d->bd_writer == 0) 1805 need_upgrade = 1; 1806 CTR4(KTR_NET, "%s: filter function set by pid %d, " 1807 "bd_writer counter %d, need_upgrade %d", 1808 __func__, d->bd_pid, d->bd_writer, need_upgrade); 1809 } 1810 } 1811 BPFD_UNLOCK(d); 1812 if (d->bd_bif != NULL) 1813 BPFIF_WUNLOCK(d->bd_bif); 1814 if (old != NULL) 1815 free(old, M_BPF); 1816#ifdef BPF_JITTER 1817 if (ofunc != NULL) 1818 bpf_destroy_jit_filter(ofunc); 1819#endif 1820 1821 /* Move d to active readers list. */ 1822 if (need_upgrade) 1823 bpf_upgraded(d); 1824 1825 BPF_UNLOCK(); 1826 return (0); 1827} 1828 1829/* 1830 * Detach a file from its current interface (if attached at all) and attach 1831 * to the interface indicated by the name stored in ifr. 1832 * Return an errno or 0. 1833 */ 1834static int 1835bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1836{ 1837 struct bpf_if *bp; 1838 struct ifnet *theywant; 1839 1840 BPF_LOCK_ASSERT(); 1841 1842 theywant = ifunit(ifr->ifr_name); 1843 if (theywant == NULL || theywant->if_bpf == NULL) 1844 return (ENXIO); 1845 1846 bp = theywant->if_bpf; 1847 1848 /* Check if interface is not being detached from BPF */ 1849 BPFIF_RLOCK(bp); 1850 if (bp->flags & BPFIF_FLAG_DYING) { 1851 BPFIF_RUNLOCK(bp); 1852 return (ENXIO); 1853 } 1854 BPFIF_RUNLOCK(bp); 1855 1856 /* 1857 * Behavior here depends on the buffering model. If we're using 1858 * kernel memory buffers, then we can allocate them here. If we're 1859 * using zero-copy, then the user process must have registered 1860 * buffers by the time we get here. If not, return an error. 1861 */ 1862 switch (d->bd_bufmode) { 1863 case BPF_BUFMODE_BUFFER: 1864 case BPF_BUFMODE_ZBUF: 1865 if (d->bd_sbuf == NULL) 1866 return (EINVAL); 1867 break; 1868 1869 default: 1870 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1871 } 1872 if (bp != d->bd_bif) 1873 bpf_attachd(d, bp); 1874 BPFD_LOCK(d); 1875 reset_d(d); 1876 BPFD_UNLOCK(d); 1877 return (0); 1878} 1879 1880/* 1881 * Support for select() and poll() system calls 1882 * 1883 * Return true iff the specific operation will not block indefinitely. 1884 * Otherwise, return false but make a note that a selwakeup() must be done. 1885 */ 1886static int 1887bpfpoll(struct cdev *dev, int events, struct thread *td) 1888{ 1889 struct bpf_d *d; 1890 int revents; 1891 1892 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 1893 return (events & 1894 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 1895 1896 /* 1897 * Refresh PID associated with this descriptor. 1898 */ 1899 revents = events & (POLLOUT | POLLWRNORM); 1900 BPFD_LOCK(d); 1901 BPF_PID_REFRESH(d, td); 1902 if (events & (POLLIN | POLLRDNORM)) { 1903 if (bpf_ready(d)) 1904 revents |= events & (POLLIN | POLLRDNORM); 1905 else { 1906 selrecord(td, &d->bd_sel); 1907 /* Start the read timeout if necessary. */ 1908 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1909 callout_reset(&d->bd_callout, d->bd_rtout, 1910 bpf_timed_out, d); 1911 d->bd_state = BPF_WAITING; 1912 } 1913 } 1914 } 1915 BPFD_UNLOCK(d); 1916 return (revents); 1917} 1918 1919/* 1920 * Support for kevent() system call. Register EVFILT_READ filters and 1921 * reject all others. 1922 */ 1923int 1924bpfkqfilter(struct cdev *dev, struct knote *kn) 1925{ 1926 struct bpf_d *d; 1927 1928 if (devfs_get_cdevpriv((void **)&d) != 0 || 1929 kn->kn_filter != EVFILT_READ) 1930 return (1); 1931 1932 /* 1933 * Refresh PID associated with this descriptor. 1934 */ 1935 BPFD_LOCK(d); 1936 BPF_PID_REFRESH_CUR(d); 1937 kn->kn_fop = &bpfread_filtops; 1938 kn->kn_hook = d; 1939 knlist_add(&d->bd_sel.si_note, kn, 1); 1940 BPFD_UNLOCK(d); 1941 1942 return (0); 1943} 1944 1945static void 1946filt_bpfdetach(struct knote *kn) 1947{ 1948 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1949 1950 knlist_remove(&d->bd_sel.si_note, kn, 0); 1951} 1952 1953static int 1954filt_bpfread(struct knote *kn, long hint) 1955{ 1956 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1957 int ready; 1958 1959 BPFD_LOCK_ASSERT(d); 1960 ready = bpf_ready(d); 1961 if (ready) { 1962 kn->kn_data = d->bd_slen; 1963 while (d->bd_hbuf_in_use) 1964 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1965 PRINET, "bd_hbuf", 0); 1966 if (d->bd_hbuf) 1967 kn->kn_data += d->bd_hlen; 1968 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1969 callout_reset(&d->bd_callout, d->bd_rtout, 1970 bpf_timed_out, d); 1971 d->bd_state = BPF_WAITING; 1972 } 1973 1974 return (ready); 1975} 1976 1977#define BPF_TSTAMP_NONE 0 1978#define BPF_TSTAMP_FAST 1 1979#define BPF_TSTAMP_NORMAL 2 1980#define BPF_TSTAMP_EXTERN 3 1981 1982static int 1983bpf_ts_quality(int tstype) 1984{ 1985 1986 if (tstype == BPF_T_NONE) 1987 return (BPF_TSTAMP_NONE); 1988 if ((tstype & BPF_T_FAST) != 0) 1989 return (BPF_TSTAMP_FAST); 1990 1991 return (BPF_TSTAMP_NORMAL); 1992} 1993 1994static int 1995bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 1996{ 1997 struct m_tag *tag; 1998 int quality; 1999 2000 quality = bpf_ts_quality(tstype); 2001 if (quality == BPF_TSTAMP_NONE) 2002 return (quality); 2003 2004 if (m != NULL) { 2005 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2006 if (tag != NULL) { 2007 *bt = *(struct bintime *)(tag + 1); 2008 return (BPF_TSTAMP_EXTERN); 2009 } 2010 } 2011 if (quality == BPF_TSTAMP_NORMAL) 2012 binuptime(bt); 2013 else 2014 getbinuptime(bt); 2015 2016 return (quality); 2017} 2018 2019/* 2020 * Incoming linkage from device drivers. Process the packet pkt, of length 2021 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2022 * by each process' filter, and if accepted, stashed into the corresponding 2023 * buffer. 2024 */ 2025void 2026bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2027{ 2028 struct bintime bt; 2029 struct bpf_d *d; 2030#ifdef BPF_JITTER 2031 bpf_jit_filter *bf; 2032#endif 2033 u_int slen; 2034 int gottime; 2035 2036 gottime = BPF_TSTAMP_NONE; 2037 2038 BPFIF_RLOCK(bp); 2039 2040 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2041 /* 2042 * We are not using any locks for d here because: 2043 * 1) any filter change is protected by interface 2044 * write lock 2045 * 2) destroying/detaching d is protected by interface 2046 * write lock, too 2047 */ 2048 2049 /* XXX: Do not protect counter for the sake of performance. */ 2050 ++d->bd_rcount; 2051 /* 2052 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no 2053 * way for the caller to indiciate to us whether this packet 2054 * is inbound or outbound. In the bpf_mtap() routines, we use 2055 * the interface pointers on the mbuf to figure it out. 2056 */ 2057#ifdef BPF_JITTER 2058 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2059 if (bf != NULL) 2060 slen = (*(bf->func))(pkt, pktlen, pktlen); 2061 else 2062#endif 2063 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2064 if (slen != 0) { 2065 /* 2066 * Filter matches. Let's to acquire write lock. 2067 */ 2068 BPFD_LOCK(d); 2069 2070 d->bd_fcount++; 2071 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2072 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL); 2073#ifdef MAC 2074 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2075#endif 2076 catchpacket(d, pkt, pktlen, slen, 2077 bpf_append_bytes, &bt); 2078 BPFD_UNLOCK(d); 2079 } 2080 } 2081 BPFIF_RUNLOCK(bp); 2082} 2083 2084#define BPF_CHECK_DIRECTION(d, r, i) \ 2085 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2086 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2087 2088/* 2089 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2090 * Locking model is explained in bpf_tap(). 2091 */ 2092void 2093bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2094{ 2095 struct bintime bt; 2096 struct bpf_d *d; 2097#ifdef BPF_JITTER 2098 bpf_jit_filter *bf; 2099#endif 2100 u_int pktlen, slen; 2101 int gottime; 2102 2103 /* Skip outgoing duplicate packets. */ 2104 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2105 m->m_flags &= ~M_PROMISC; 2106 return; 2107 } 2108 2109 pktlen = m_length(m, NULL); 2110 gottime = BPF_TSTAMP_NONE; 2111 2112 BPFIF_RLOCK(bp); 2113 2114 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2115 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2116 continue; 2117 ++d->bd_rcount; 2118#ifdef BPF_JITTER 2119 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2120 /* XXX We cannot handle multiple mbufs. */ 2121 if (bf != NULL && m->m_next == NULL) 2122 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); 2123 else 2124#endif 2125 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2126 if (slen != 0) { 2127 BPFD_LOCK(d); 2128 2129 d->bd_fcount++; 2130 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2131 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2132#ifdef MAC 2133 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2134#endif 2135 catchpacket(d, (u_char *)m, pktlen, slen, 2136 bpf_append_mbuf, &bt); 2137 BPFD_UNLOCK(d); 2138 } 2139 } 2140 BPFIF_RUNLOCK(bp); 2141} 2142 2143/* 2144 * Incoming linkage from device drivers, when packet is in 2145 * an mbuf chain and to be prepended by a contiguous header. 2146 */ 2147void 2148bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2149{ 2150 struct bintime bt; 2151 struct mbuf mb; 2152 struct bpf_d *d; 2153 u_int pktlen, slen; 2154 int gottime; 2155 2156 /* Skip outgoing duplicate packets. */ 2157 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2158 m->m_flags &= ~M_PROMISC; 2159 return; 2160 } 2161 2162 pktlen = m_length(m, NULL); 2163 /* 2164 * Craft on-stack mbuf suitable for passing to bpf_filter. 2165 * Note that we cut corners here; we only setup what's 2166 * absolutely needed--this mbuf should never go anywhere else. 2167 */ 2168 mb.m_next = m; 2169 mb.m_data = data; 2170 mb.m_len = dlen; 2171 pktlen += dlen; 2172 2173 gottime = BPF_TSTAMP_NONE; 2174 2175 BPFIF_RLOCK(bp); 2176 2177 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2178 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2179 continue; 2180 ++d->bd_rcount; 2181 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2182 if (slen != 0) { 2183 BPFD_LOCK(d); 2184 2185 d->bd_fcount++; 2186 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2187 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2188#ifdef MAC 2189 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2190#endif 2191 catchpacket(d, (u_char *)&mb, pktlen, slen, 2192 bpf_append_mbuf, &bt); 2193 BPFD_UNLOCK(d); 2194 } 2195 } 2196 BPFIF_RUNLOCK(bp); 2197} 2198 2199#undef BPF_CHECK_DIRECTION 2200 2201#undef BPF_TSTAMP_NONE 2202#undef BPF_TSTAMP_FAST 2203#undef BPF_TSTAMP_NORMAL 2204#undef BPF_TSTAMP_EXTERN 2205 2206static int 2207bpf_hdrlen(struct bpf_d *d) 2208{ 2209 int hdrlen; 2210 2211 hdrlen = d->bd_bif->bif_hdrlen; 2212#ifndef BURN_BRIDGES 2213 if (d->bd_tstamp == BPF_T_NONE || 2214 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2215#ifdef COMPAT_FREEBSD32 2216 if (d->bd_compat32) 2217 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2218 else 2219#endif 2220 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2221 else 2222#endif 2223 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2224#ifdef COMPAT_FREEBSD32 2225 if (d->bd_compat32) 2226 hdrlen = BPF_WORDALIGN32(hdrlen); 2227 else 2228#endif 2229 hdrlen = BPF_WORDALIGN(hdrlen); 2230 2231 return (hdrlen - d->bd_bif->bif_hdrlen); 2232} 2233 2234static void 2235bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2236{ 2237 struct bintime bt2; 2238 struct timeval tsm; 2239 struct timespec tsn; 2240 2241 if ((tstype & BPF_T_MONOTONIC) == 0) { 2242 bt2 = *bt; 2243 bintime_add(&bt2, &boottimebin); 2244 bt = &bt2; 2245 } 2246 switch (BPF_T_FORMAT(tstype)) { 2247 case BPF_T_MICROTIME: 2248 bintime2timeval(bt, &tsm); 2249 ts->bt_sec = tsm.tv_sec; 2250 ts->bt_frac = tsm.tv_usec; 2251 break; 2252 case BPF_T_NANOTIME: 2253 bintime2timespec(bt, &tsn); 2254 ts->bt_sec = tsn.tv_sec; 2255 ts->bt_frac = tsn.tv_nsec; 2256 break; 2257 case BPF_T_BINTIME: 2258 ts->bt_sec = bt->sec; 2259 ts->bt_frac = bt->frac; 2260 break; 2261 } 2262} 2263 2264/* 2265 * Move the packet data from interface memory (pkt) into the 2266 * store buffer. "cpfn" is the routine called to do the actual data 2267 * transfer. bcopy is passed in to copy contiguous chunks, while 2268 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2269 * pkt is really an mbuf. 2270 */ 2271static void 2272catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2273 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2274 struct bintime *bt) 2275{ 2276 struct bpf_xhdr hdr; 2277#ifndef BURN_BRIDGES 2278 struct bpf_hdr hdr_old; 2279#ifdef COMPAT_FREEBSD32 2280 struct bpf_hdr32 hdr32_old; 2281#endif 2282#endif 2283 int caplen, curlen, hdrlen, totlen; 2284 int do_wakeup = 0; 2285 int do_timestamp; 2286 int tstype; 2287 2288 BPFD_LOCK_ASSERT(d); 2289 2290 /* 2291 * Detect whether user space has released a buffer back to us, and if 2292 * so, move it from being a hold buffer to a free buffer. This may 2293 * not be the best place to do it (for example, we might only want to 2294 * run this check if we need the space), but for now it's a reliable 2295 * spot to do it. 2296 */ 2297 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2298 while (d->bd_hbuf_in_use) 2299 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 2300 PRINET, "bd_hbuf", 0); 2301 d->bd_fbuf = d->bd_hbuf; 2302 d->bd_hbuf = NULL; 2303 d->bd_hlen = 0; 2304 bpf_buf_reclaimed(d); 2305 } 2306 2307 /* 2308 * Figure out how many bytes to move. If the packet is 2309 * greater or equal to the snapshot length, transfer that 2310 * much. Otherwise, transfer the whole packet (unless 2311 * we hit the buffer size limit). 2312 */ 2313 hdrlen = bpf_hdrlen(d); 2314 totlen = hdrlen + min(snaplen, pktlen); 2315 if (totlen > d->bd_bufsize) 2316 totlen = d->bd_bufsize; 2317 2318 /* 2319 * Round up the end of the previous packet to the next longword. 2320 * 2321 * Drop the packet if there's no room and no hope of room 2322 * If the packet would overflow the storage buffer or the storage 2323 * buffer is considered immutable by the buffer model, try to rotate 2324 * the buffer and wakeup pending processes. 2325 */ 2326#ifdef COMPAT_FREEBSD32 2327 if (d->bd_compat32) 2328 curlen = BPF_WORDALIGN32(d->bd_slen); 2329 else 2330#endif 2331 curlen = BPF_WORDALIGN(d->bd_slen); 2332 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2333 if (d->bd_fbuf == NULL) { 2334 /* 2335 * There's no room in the store buffer, and no 2336 * prospect of room, so drop the packet. Notify the 2337 * buffer model. 2338 */ 2339 bpf_buffull(d); 2340 ++d->bd_dcount; 2341 return; 2342 } 2343 while (d->bd_hbuf_in_use) 2344 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 2345 PRINET, "bd_hbuf", 0); 2346 ROTATE_BUFFERS(d); 2347 do_wakeup = 1; 2348 curlen = 0; 2349 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2350 /* 2351 * Immediate mode is set, or the read timeout has already 2352 * expired during a select call. A packet arrived, so the 2353 * reader should be woken up. 2354 */ 2355 do_wakeup = 1; 2356 caplen = totlen - hdrlen; 2357 tstype = d->bd_tstamp; 2358 do_timestamp = tstype != BPF_T_NONE; 2359#ifndef BURN_BRIDGES 2360 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2361 struct bpf_ts ts; 2362 if (do_timestamp) 2363 bpf_bintime2ts(bt, &ts, tstype); 2364#ifdef COMPAT_FREEBSD32 2365 if (d->bd_compat32) { 2366 bzero(&hdr32_old, sizeof(hdr32_old)); 2367 if (do_timestamp) { 2368 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2369 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2370 } 2371 hdr32_old.bh_datalen = pktlen; 2372 hdr32_old.bh_hdrlen = hdrlen; 2373 hdr32_old.bh_caplen = caplen; 2374 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2375 sizeof(hdr32_old)); 2376 goto copy; 2377 } 2378#endif 2379 bzero(&hdr_old, sizeof(hdr_old)); 2380 if (do_timestamp) { 2381 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2382 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2383 } 2384 hdr_old.bh_datalen = pktlen; 2385 hdr_old.bh_hdrlen = hdrlen; 2386 hdr_old.bh_caplen = caplen; 2387 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2388 sizeof(hdr_old)); 2389 goto copy; 2390 } 2391#endif 2392 2393 /* 2394 * Append the bpf header. Note we append the actual header size, but 2395 * move forward the length of the header plus padding. 2396 */ 2397 bzero(&hdr, sizeof(hdr)); 2398 if (do_timestamp) 2399 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2400 hdr.bh_datalen = pktlen; 2401 hdr.bh_hdrlen = hdrlen; 2402 hdr.bh_caplen = caplen; 2403 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2404 2405 /* 2406 * Copy the packet data into the store buffer and update its length. 2407 */ 2408#ifndef BURN_BRIDGES 2409copy: 2410#endif 2411 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2412 d->bd_slen = curlen + totlen; 2413 2414 if (do_wakeup) 2415 bpf_wakeup(d); 2416} 2417 2418/* 2419 * Free buffers currently in use by a descriptor. 2420 * Called on close. 2421 */ 2422static void 2423bpf_freed(struct bpf_d *d) 2424{ 2425 2426 /* 2427 * We don't need to lock out interrupts since this descriptor has 2428 * been detached from its interface and it yet hasn't been marked 2429 * free. 2430 */ 2431 bpf_free(d); 2432 if (d->bd_rfilter != NULL) { 2433 free((caddr_t)d->bd_rfilter, M_BPF); 2434#ifdef BPF_JITTER 2435 if (d->bd_bfilter != NULL) 2436 bpf_destroy_jit_filter(d->bd_bfilter); 2437#endif 2438 } 2439 if (d->bd_wfilter != NULL) 2440 free((caddr_t)d->bd_wfilter, M_BPF); 2441 mtx_destroy(&d->bd_lock); 2442} 2443 2444/* 2445 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2446 * fixed size of the link header (variable length headers not yet supported). 2447 */ 2448void 2449bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2450{ 2451 2452 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2453} 2454 2455/* 2456 * Attach an interface to bpf. ifp is a pointer to the structure 2457 * defining the interface to be attached, dlt is the link layer type, 2458 * and hdrlen is the fixed size of the link header (variable length 2459 * headers are not yet supporrted). 2460 */ 2461void 2462bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2463{ 2464 struct bpf_if *bp; 2465 2466 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 2467 if (bp == NULL) 2468 panic("bpfattach"); 2469 2470 LIST_INIT(&bp->bif_dlist); 2471 LIST_INIT(&bp->bif_wlist); 2472 bp->bif_ifp = ifp; 2473 bp->bif_dlt = dlt; 2474 rw_init(&bp->bif_lock, "bpf interface lock"); 2475 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 2476 *driverp = bp; 2477 2478 BPF_LOCK(); 2479 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2480 BPF_UNLOCK(); 2481 2482 bp->bif_hdrlen = hdrlen; 2483 2484 if (bootverbose) 2485 if_printf(ifp, "bpf attached\n"); 2486} 2487 2488/* 2489 * Detach bpf from an interface. This involves detaching each descriptor 2490 * associated with the interface. Notify each descriptor as it's detached 2491 * so that any sleepers wake up and get ENXIO. 2492 */ 2493void 2494bpfdetach(struct ifnet *ifp) 2495{ 2496 struct bpf_if *bp, *bp_temp; 2497 struct bpf_d *d; 2498 int ndetached; 2499 2500 ndetached = 0; 2501 2502 BPF_LOCK(); 2503 /* Find all bpf_if struct's which reference ifp and detach them. */ 2504 LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2505 if (ifp != bp->bif_ifp) 2506 continue; 2507 2508 LIST_REMOVE(bp, bif_next); 2509 /* Add to to-be-freed list */ 2510 LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next); 2511 2512 ndetached++; 2513 /* 2514 * Delay freeing bp till interface is detached 2515 * and all routes through this interface are removed. 2516 * Mark bp as detached to restrict new consumers. 2517 */ 2518 BPFIF_WLOCK(bp); 2519 bp->flags |= BPFIF_FLAG_DYING; 2520 BPFIF_WUNLOCK(bp); 2521 2522 CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p", 2523 __func__, bp->bif_dlt, bp, ifp); 2524 2525 /* Free common descriptors */ 2526 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 2527 bpf_detachd_locked(d); 2528 BPFD_LOCK(d); 2529 bpf_wakeup(d); 2530 BPFD_UNLOCK(d); 2531 } 2532 2533 /* Free writer-only descriptors */ 2534 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) { 2535 bpf_detachd_locked(d); 2536 BPFD_LOCK(d); 2537 bpf_wakeup(d); 2538 BPFD_UNLOCK(d); 2539 } 2540 } 2541 BPF_UNLOCK(); 2542 2543#ifdef INVARIANTS 2544 if (ndetached == 0) 2545 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 2546#endif 2547} 2548 2549/* 2550 * Interface departure handler. 2551 * Note departure event does not guarantee interface is going down. 2552 * Interface renaming is currently done via departure/arrival event set. 2553 * 2554 * Departure handled is called after all routes pointing to 2555 * given interface are removed and interface is in down state 2556 * restricting any packets to be sent/received. We assume it is now safe 2557 * to free data allocated by BPF. 2558 */ 2559static void 2560bpf_ifdetach(void *arg __unused, struct ifnet *ifp) 2561{ 2562 struct bpf_if *bp, *bp_temp; 2563 int nmatched = 0; 2564 2565 BPF_LOCK(); 2566 /* 2567 * Find matching entries in free list. 2568 * Nothing should be found if bpfdetach() was not called. 2569 */ 2570 LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) { 2571 if (ifp != bp->bif_ifp) 2572 continue; 2573 2574 CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p", 2575 __func__, bp, ifp); 2576 2577 LIST_REMOVE(bp, bif_next); 2578 2579 rw_destroy(&bp->bif_lock); 2580 free(bp, M_BPF); 2581 2582 nmatched++; 2583 } 2584 BPF_UNLOCK(); 2585 2586 /* 2587 * Note that we cannot zero other pointers to 2588 * custom DLTs possibly used by given interface. 2589 */ 2590 if (nmatched != 0) 2591 ifp->if_bpf = NULL; 2592} 2593 2594/* 2595 * Get a list of available data link type of the interface. 2596 */ 2597static int 2598bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2599{ 2600 int n, error; 2601 struct ifnet *ifp; 2602 struct bpf_if *bp; 2603 2604 BPF_LOCK_ASSERT(); 2605 2606 ifp = d->bd_bif->bif_ifp; 2607 n = 0; 2608 error = 0; 2609 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2610 if (bp->bif_ifp != ifp) 2611 continue; 2612 if (bfl->bfl_list != NULL) { 2613 if (n >= bfl->bfl_len) 2614 return (ENOMEM); 2615 error = copyout(&bp->bif_dlt, 2616 bfl->bfl_list + n, sizeof(u_int)); 2617 } 2618 n++; 2619 } 2620 bfl->bfl_len = n; 2621 return (error); 2622} 2623 2624/* 2625 * Set the data link type of a BPF instance. 2626 */ 2627static int 2628bpf_setdlt(struct bpf_d *d, u_int dlt) 2629{ 2630 int error, opromisc; 2631 struct ifnet *ifp; 2632 struct bpf_if *bp; 2633 2634 BPF_LOCK_ASSERT(); 2635 2636 if (d->bd_bif->bif_dlt == dlt) 2637 return (0); 2638 ifp = d->bd_bif->bif_ifp; 2639 2640 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2641 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2642 break; 2643 } 2644 2645 if (bp != NULL) { 2646 opromisc = d->bd_promisc; 2647 bpf_attachd(d, bp); 2648 BPFD_LOCK(d); 2649 reset_d(d); 2650 BPFD_UNLOCK(d); 2651 if (opromisc) { 2652 error = ifpromisc(bp->bif_ifp, 1); 2653 if (error) 2654 if_printf(bp->bif_ifp, 2655 "bpf_setdlt: ifpromisc failed (%d)\n", 2656 error); 2657 else 2658 d->bd_promisc = 1; 2659 } 2660 } 2661 return (bp == NULL ? EINVAL : 0); 2662} 2663 2664static void 2665bpf_drvinit(void *unused) 2666{ 2667 struct cdev *dev; 2668 2669 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2670 LIST_INIT(&bpf_iflist); 2671 LIST_INIT(&bpf_freelist); 2672 2673 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2674 /* For compatibility */ 2675 make_dev_alias(dev, "bpf0"); 2676 2677 /* Register interface departure handler */ 2678 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER( 2679 ifnet_departure_event, bpf_ifdetach, NULL, 2680 EVENTHANDLER_PRI_ANY); 2681} 2682 2683/* 2684 * Zero out the various packet counters associated with all of the bpf 2685 * descriptors. At some point, we will probably want to get a bit more 2686 * granular and allow the user to specify descriptors to be zeroed. 2687 */ 2688static void 2689bpf_zero_counters(void) 2690{ 2691 struct bpf_if *bp; 2692 struct bpf_d *bd; 2693 2694 BPF_LOCK(); 2695 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2696 BPFIF_RLOCK(bp); 2697 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2698 BPFD_LOCK(bd); 2699 bd->bd_rcount = 0; 2700 bd->bd_dcount = 0; 2701 bd->bd_fcount = 0; 2702 bd->bd_wcount = 0; 2703 bd->bd_wfcount = 0; 2704 bd->bd_zcopy = 0; 2705 BPFD_UNLOCK(bd); 2706 } 2707 BPFIF_RUNLOCK(bp); 2708 } 2709 BPF_UNLOCK(); 2710} 2711 2712/* 2713 * Fill filter statistics 2714 */ 2715static void 2716bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2717{ 2718 2719 bzero(d, sizeof(*d)); 2720 BPFD_LOCK_ASSERT(bd); 2721 d->bd_structsize = sizeof(*d); 2722 /* XXX: reading should be protected by global lock */ 2723 d->bd_immediate = bd->bd_immediate; 2724 d->bd_promisc = bd->bd_promisc; 2725 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2726 d->bd_direction = bd->bd_direction; 2727 d->bd_feedback = bd->bd_feedback; 2728 d->bd_async = bd->bd_async; 2729 d->bd_rcount = bd->bd_rcount; 2730 d->bd_dcount = bd->bd_dcount; 2731 d->bd_fcount = bd->bd_fcount; 2732 d->bd_sig = bd->bd_sig; 2733 d->bd_slen = bd->bd_slen; 2734 d->bd_hlen = bd->bd_hlen; 2735 d->bd_bufsize = bd->bd_bufsize; 2736 d->bd_pid = bd->bd_pid; 2737 strlcpy(d->bd_ifname, 2738 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2739 d->bd_locked = bd->bd_locked; 2740 d->bd_wcount = bd->bd_wcount; 2741 d->bd_wdcount = bd->bd_wdcount; 2742 d->bd_wfcount = bd->bd_wfcount; 2743 d->bd_zcopy = bd->bd_zcopy; 2744 d->bd_bufmode = bd->bd_bufmode; 2745} 2746 2747/* 2748 * Handle `netstat -B' stats request 2749 */ 2750static int 2751bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2752{ 2753 struct xbpf_d *xbdbuf, *xbd, zerostats; 2754 int index, error; 2755 struct bpf_if *bp; 2756 struct bpf_d *bd; 2757 2758 /* 2759 * XXX This is not technically correct. It is possible for non 2760 * privileged users to open bpf devices. It would make sense 2761 * if the users who opened the devices were able to retrieve 2762 * the statistics for them, too. 2763 */ 2764 error = priv_check(req->td, PRIV_NET_BPF); 2765 if (error) 2766 return (error); 2767 /* 2768 * Check to see if the user is requesting that the counters be 2769 * zeroed out. Explicitly check that the supplied data is zeroed, 2770 * as we aren't allowing the user to set the counters currently. 2771 */ 2772 if (req->newptr != NULL) { 2773 if (req->newlen != sizeof(zerostats)) 2774 return (EINVAL); 2775 bzero(&zerostats, sizeof(zerostats)); 2776 xbd = req->newptr; 2777 if (bcmp(xbd, &zerostats, sizeof(*xbd)) != 0) 2778 return (EINVAL); 2779 bpf_zero_counters(); 2780 return (0); 2781 } 2782 if (req->oldptr == NULL) 2783 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2784 if (bpf_bpfd_cnt == 0) 2785 return (SYSCTL_OUT(req, 0, 0)); 2786 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2787 BPF_LOCK(); 2788 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2789 BPF_UNLOCK(); 2790 free(xbdbuf, M_BPF); 2791 return (ENOMEM); 2792 } 2793 index = 0; 2794 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2795 BPFIF_RLOCK(bp); 2796 /* Send writers-only first */ 2797 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2798 xbd = &xbdbuf[index++]; 2799 BPFD_LOCK(bd); 2800 bpfstats_fill_xbpf(xbd, bd); 2801 BPFD_UNLOCK(bd); 2802 } 2803 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2804 xbd = &xbdbuf[index++]; 2805 BPFD_LOCK(bd); 2806 bpfstats_fill_xbpf(xbd, bd); 2807 BPFD_UNLOCK(bd); 2808 } 2809 BPFIF_RUNLOCK(bp); 2810 } 2811 BPF_UNLOCK(); 2812 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2813 free(xbdbuf, M_BPF); 2814 return (error); 2815} 2816 2817SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2818 2819#else /* !DEV_BPF && !NETGRAPH_BPF */ 2820/* 2821 * NOP stubs to allow bpf-using drivers to load and function. 2822 * 2823 * A 'better' implementation would allow the core bpf functionality 2824 * to be loaded at runtime. 2825 */ 2826static struct bpf_if bp_null; 2827 2828void 2829bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2830{ 2831} 2832 2833void 2834bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2835{ 2836} 2837 2838void 2839bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2840{ 2841} 2842 2843void 2844bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2845{ 2846 2847 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2848} 2849 2850void 2851bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2852{ 2853 2854 *driverp = &bp_null; 2855} 2856 2857void 2858bpfdetach(struct ifnet *ifp) 2859{ 2860} 2861 2862u_int 2863bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 2864{ 2865 return -1; /* "no filter" behaviour */ 2866} 2867 2868int 2869bpf_validate(const struct bpf_insn *f, int len) 2870{ 2871 return 0; /* false */ 2872} 2873 2874#endif /* !DEV_BPF && !NETGRAPH_BPF */ 2875