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("$FreeBSD$"); 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 #include <net/if_var.h> 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 90 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 91 92 struct bpf_if { 93 #define bif_next bif_ext.bif_next 94 #define bif_dlist bif_ext.bif_dlist 95 struct bpf_if_ext bif_ext; /* public members */ 96 u_int bif_dlt; /* link layer type */ 97 u_int bif_hdrlen; /* length of link header */ 98 struct ifnet *bif_ifp; /* corresponding interface */ 99 struct rwlock bif_lock; /* interface lock */ 100 LIST_HEAD(, bpf_d) bif_wlist; /* writer-only list */ 101 int bif_flags; /* Interface flags */ 102 }; 103 104 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); 105 106 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 107 108 #define PRINET 26 /* interruptible */ 109 110 #define SIZEOF_BPF_HDR(type) \ 111 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 112 113 #ifdef COMPAT_FREEBSD32 114 #include <sys/mount.h> 115 #include <compat/freebsd32/freebsd32.h> 116 #define BPF_ALIGNMENT32 sizeof(int32_t) 117 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1)) 118 119 #ifndef BURN_BRIDGES 120 /* 121 * 32-bit version of structure prepended to each packet. We use this header 122 * instead of the standard one for 32-bit streams. We mark the a stream as 123 * 32-bit the first time we see a 32-bit compat ioctl request. 124 */ 125 struct bpf_hdr32 { 126 struct timeval32 bh_tstamp; /* time stamp */ 127 uint32_t bh_caplen; /* length of captured portion */ 128 uint32_t bh_datalen; /* original length of packet */ 129 uint16_t bh_hdrlen; /* length of bpf header (this struct 130 plus alignment padding) */ 131 }; 132 #endif 133 134 struct bpf_program32 { 135 u_int bf_len; 136 uint32_t bf_insns; 137 }; 138 139 struct bpf_dltlist32 { 140 u_int bfl_len; 141 u_int bfl_list; 142 }; 143 144 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 145 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 146 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 147 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 148 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 149 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 150 #endif 151 152 /* 153 * bpf_iflist is a list of BPF interface structures, each corresponding to a 154 * specific DLT. The same network interface might have several BPF interface 155 * structures registered by different layers in the stack (i.e., 802.11 156 * frames, ethernet frames, etc). 157 */ 158 static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist; 159 static struct mtx bpf_mtx; /* bpf global lock */ 160 static int bpf_bpfd_cnt; 161 162 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 163 static void bpf_detachd(struct bpf_d *); 164 static void bpf_detachd_locked(struct bpf_d *); 165 static void bpf_freed(struct bpf_d *); 166 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 167 struct sockaddr *, int *, struct bpf_insn *); 168 static int bpf_setif(struct bpf_d *, struct ifreq *); 169 static void bpf_timed_out(void *); 170 static __inline void 171 bpf_wakeup(struct bpf_d *); 172 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 173 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 174 struct bintime *); 175 static void reset_d(struct bpf_d *); 176 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 177 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 178 static int bpf_setdlt(struct bpf_d *, u_int); 179 static void filt_bpfdetach(struct knote *); 180 static int filt_bpfread(struct knote *, long); 181 static void bpf_drvinit(void *); 182 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 183 184 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 185 int bpf_maxinsns = BPF_MAXINSNS; 186 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 187 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 188 static int bpf_zerocopy_enable = 0; 189 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 190 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 191 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 192 bpf_stats_sysctl, "bpf statistics portal"); 193 194 static VNET_DEFINE(int, bpf_optimize_writers) = 0; 195 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 196 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RW, 197 &VNET_NAME(bpf_optimize_writers), 0, 198 "Do not send packets until BPF program is set"); 199 200 static d_open_t bpfopen; 201 static d_read_t bpfread; 202 static d_write_t bpfwrite; 203 static d_ioctl_t bpfioctl; 204 static d_poll_t bpfpoll; 205 static d_kqfilter_t bpfkqfilter; 206 207 static struct cdevsw bpf_cdevsw = { 208 .d_version = D_VERSION, 209 .d_open = bpfopen, 210 .d_read = bpfread, 211 .d_write = bpfwrite, 212 .d_ioctl = bpfioctl, 213 .d_poll = bpfpoll, 214 .d_name = "bpf", 215 .d_kqfilter = bpfkqfilter, 216 }; 217 218 static struct filterops bpfread_filtops = { 219 .f_isfd = 1, 220 .f_detach = filt_bpfdetach, 221 .f_event = filt_bpfread, 222 }; 223 224 eventhandler_tag bpf_ifdetach_cookie = NULL; 225 226 /* 227 * LOCKING MODEL USED BY BPF: 228 * Locks: 229 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal, 230 * some global counters and every bpf_if reference. 231 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters. 232 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields 233 * used by bpf_mtap code. 234 * 235 * Lock order: 236 * 237 * Global lock, interface lock, descriptor lock 238 * 239 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2] 240 * working model. In many places (like bpf_detachd) we start with BPF descriptor 241 * (and we need to at least rlock it to get reliable interface pointer). This 242 * gives us potential LOR. As a result, we use global lock to protect from bpf_if 243 * change in every such place. 244 * 245 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and 246 * 3) descriptor main wlock. 247 * Reading bd_bif can be protected by any of these locks, typically global lock. 248 * 249 * Changing read/write BPF filter is protected by the same three locks, 250 * the same applies for reading. 251 * 252 * Sleeping in global lock is not allowed due to bpfdetach() using it. 253 */ 254 255 /* 256 * Wrapper functions for various buffering methods. If the set of buffer 257 * modes expands, we will probably want to introduce a switch data structure 258 * similar to protosw, et. 259 */ 260 static void 261 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 262 u_int len) 263 { 264 265 BPFD_LOCK_ASSERT(d); 266 267 switch (d->bd_bufmode) { 268 case BPF_BUFMODE_BUFFER: 269 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 270 271 case BPF_BUFMODE_ZBUF: 272 d->bd_zcopy++; 273 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 274 275 default: 276 panic("bpf_buf_append_bytes"); 277 } 278 } 279 280 static void 281 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 282 u_int len) 283 { 284 285 BPFD_LOCK_ASSERT(d); 286 287 switch (d->bd_bufmode) { 288 case BPF_BUFMODE_BUFFER: 289 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 290 291 case BPF_BUFMODE_ZBUF: 292 d->bd_zcopy++; 293 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 294 295 default: 296 panic("bpf_buf_append_mbuf"); 297 } 298 } 299 300 /* 301 * This function gets called when the free buffer is re-assigned. 302 */ 303 static void 304 bpf_buf_reclaimed(struct bpf_d *d) 305 { 306 307 BPFD_LOCK_ASSERT(d); 308 309 switch (d->bd_bufmode) { 310 case BPF_BUFMODE_BUFFER: 311 return; 312 313 case BPF_BUFMODE_ZBUF: 314 bpf_zerocopy_buf_reclaimed(d); 315 return; 316 317 default: 318 panic("bpf_buf_reclaimed"); 319 } 320 } 321 322 /* 323 * If the buffer mechanism has a way to decide that a held buffer can be made 324 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 325 * returned if the buffer can be discarded, (0) is returned if it cannot. 326 */ 327 static int 328 bpf_canfreebuf(struct bpf_d *d) 329 { 330 331 BPFD_LOCK_ASSERT(d); 332 333 switch (d->bd_bufmode) { 334 case BPF_BUFMODE_ZBUF: 335 return (bpf_zerocopy_canfreebuf(d)); 336 } 337 return (0); 338 } 339 340 /* 341 * Allow the buffer model to indicate that the current store buffer is 342 * immutable, regardless of the appearance of space. Return (1) if the 343 * buffer is writable, and (0) if not. 344 */ 345 static int 346 bpf_canwritebuf(struct bpf_d *d) 347 { 348 BPFD_LOCK_ASSERT(d); 349 350 switch (d->bd_bufmode) { 351 case BPF_BUFMODE_ZBUF: 352 return (bpf_zerocopy_canwritebuf(d)); 353 } 354 return (1); 355 } 356 357 /* 358 * Notify buffer model that an attempt to write to the store buffer has 359 * resulted in a dropped packet, in which case the buffer may be considered 360 * full. 361 */ 362 static void 363 bpf_buffull(struct bpf_d *d) 364 { 365 366 BPFD_LOCK_ASSERT(d); 367 368 switch (d->bd_bufmode) { 369 case BPF_BUFMODE_ZBUF: 370 bpf_zerocopy_buffull(d); 371 break; 372 } 373 } 374 375 /* 376 * Notify the buffer model that a buffer has moved into the hold position. 377 */ 378 void 379 bpf_bufheld(struct bpf_d *d) 380 { 381 382 BPFD_LOCK_ASSERT(d); 383 384 switch (d->bd_bufmode) { 385 case BPF_BUFMODE_ZBUF: 386 bpf_zerocopy_bufheld(d); 387 break; 388 } 389 } 390 391 static void 392 bpf_free(struct bpf_d *d) 393 { 394 395 switch (d->bd_bufmode) { 396 case BPF_BUFMODE_BUFFER: 397 return (bpf_buffer_free(d)); 398 399 case BPF_BUFMODE_ZBUF: 400 return (bpf_zerocopy_free(d)); 401 402 default: 403 panic("bpf_buf_free"); 404 } 405 } 406 407 static int 408 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 409 { 410 411 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 412 return (EOPNOTSUPP); 413 return (bpf_buffer_uiomove(d, buf, len, uio)); 414 } 415 416 static int 417 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 418 { 419 420 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 421 return (EOPNOTSUPP); 422 return (bpf_buffer_ioctl_sblen(d, i)); 423 } 424 425 static int 426 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 427 { 428 429 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 430 return (EOPNOTSUPP); 431 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 432 } 433 434 static int 435 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 436 { 437 438 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 439 return (EOPNOTSUPP); 440 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 441 } 442 443 static int 444 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 445 { 446 447 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 448 return (EOPNOTSUPP); 449 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 450 } 451 452 /* 453 * General BPF functions. 454 */ 455 static int 456 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 457 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) 458 { 459 const struct ieee80211_bpf_params *p; 460 struct ether_header *eh; 461 struct mbuf *m; 462 int error; 463 int len; 464 int hlen; 465 int slen; 466 467 /* 468 * Build a sockaddr based on the data link layer type. 469 * We do this at this level because the ethernet header 470 * is copied directly into the data field of the sockaddr. 471 * In the case of SLIP, there is no header and the packet 472 * is forwarded as is. 473 * Also, we are careful to leave room at the front of the mbuf 474 * for the link level header. 475 */ 476 switch (linktype) { 477 478 case DLT_SLIP: 479 sockp->sa_family = AF_INET; 480 hlen = 0; 481 break; 482 483 case DLT_EN10MB: 484 sockp->sa_family = AF_UNSPEC; 485 /* XXX Would MAXLINKHDR be better? */ 486 hlen = ETHER_HDR_LEN; 487 break; 488 489 case DLT_FDDI: 490 sockp->sa_family = AF_IMPLINK; 491 hlen = 0; 492 break; 493 494 case DLT_RAW: 495 sockp->sa_family = AF_UNSPEC; 496 hlen = 0; 497 break; 498 499 case DLT_NULL: 500 /* 501 * null interface types require a 4 byte pseudo header which 502 * corresponds to the address family of the packet. 503 */ 504 sockp->sa_family = AF_UNSPEC; 505 hlen = 4; 506 break; 507 508 case DLT_ATM_RFC1483: 509 /* 510 * en atm driver requires 4-byte atm pseudo header. 511 * though it isn't standard, vpi:vci needs to be 512 * specified anyway. 513 */ 514 sockp->sa_family = AF_UNSPEC; 515 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 516 break; 517 518 case DLT_PPP: 519 sockp->sa_family = AF_UNSPEC; 520 hlen = 4; /* This should match PPP_HDRLEN */ 521 break; 522 523 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 524 sockp->sa_family = AF_IEEE80211; 525 hlen = 0; 526 break; 527 528 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 529 sockp->sa_family = AF_IEEE80211; 530 sockp->sa_len = 12; /* XXX != 0 */ 531 hlen = sizeof(struct ieee80211_bpf_params); 532 break; 533 534 default: 535 return (EIO); 536 } 537 538 len = uio->uio_resid; 539 if (len < hlen || len - hlen > ifp->if_mtu) 540 return (EMSGSIZE); 541 542 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR); 543 if (m == NULL) 544 return (EIO); 545 m->m_pkthdr.len = m->m_len = len; 546 *mp = m; 547 548 error = uiomove(mtod(m, u_char *), len, uio); 549 if (error) 550 goto bad; 551 552 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 553 if (slen == 0) { 554 error = EPERM; 555 goto bad; 556 } 557 558 /* Check for multicast destination */ 559 switch (linktype) { 560 case DLT_EN10MB: 561 eh = mtod(m, struct ether_header *); 562 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 563 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 564 ETHER_ADDR_LEN) == 0) 565 m->m_flags |= M_BCAST; 566 else 567 m->m_flags |= M_MCAST; 568 } 569 break; 570 } 571 572 /* 573 * Make room for link header, and copy it to sockaddr 574 */ 575 if (hlen != 0) { 576 if (sockp->sa_family == AF_IEEE80211) { 577 /* 578 * Collect true length from the parameter header 579 * NB: sockp is known to be zero'd so if we do a 580 * short copy unspecified parameters will be 581 * zero. 582 * NB: packet may not be aligned after stripping 583 * bpf params 584 * XXX check ibp_vers 585 */ 586 p = mtod(m, const struct ieee80211_bpf_params *); 587 hlen = p->ibp_len; 588 if (hlen > sizeof(sockp->sa_data)) { 589 error = EINVAL; 590 goto bad; 591 } 592 } 593 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 594 } 595 *hdrlen = hlen; 596 597 return (0); 598 bad: 599 m_freem(m); 600 return (error); 601 } 602 603 /* 604 * Attach file to the bpf interface, i.e. make d listen on bp. 605 */ 606 static void 607 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 608 { 609 int op_w; 610 611 BPF_LOCK_ASSERT(); 612 613 /* 614 * Save sysctl value to protect from sysctl change 615 * between reads 616 */ 617 op_w = V_bpf_optimize_writers || d->bd_writer; 618 619 if (d->bd_bif != NULL) 620 bpf_detachd_locked(d); 621 /* 622 * Point d at bp, and add d to the interface's list. 623 * Since there are many applicaiotns using BPF for 624 * sending raw packets only (dhcpd, cdpd are good examples) 625 * we can delay adding d to the list of active listeners until 626 * some filter is configured. 627 */ 628 629 BPFIF_WLOCK(bp); 630 BPFD_LOCK(d); 631 632 d->bd_bif = bp; 633 634 if (op_w != 0) { 635 /* Add to writers-only list */ 636 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 637 /* 638 * We decrement bd_writer on every filter set operation. 639 * First BIOCSETF is done by pcap_open_live() to set up 640 * snap length. After that appliation usually sets its own filter 641 */ 642 d->bd_writer = 2; 643 } else 644 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 645 646 BPFD_UNLOCK(d); 647 BPFIF_WUNLOCK(bp); 648 649 bpf_bpfd_cnt++; 650 651 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 652 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 653 654 if (op_w == 0) 655 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 656 } 657 658 /* 659 * Check if we need to upgrade our descriptor @d from write-only mode. 660 */ 661 static int 662 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen) 663 { 664 int is_snap, need_upgrade; 665 666 /* 667 * Check if we've already upgraded or new filter is empty. 668 */ 669 if (d->bd_writer == 0 || fcode == NULL) 670 return (0); 671 672 need_upgrade = 0; 673 674 /* 675 * Check if cmd looks like snaplen setting from 676 * pcap_bpf.c:pcap_open_live(). 677 * Note we're not checking .k value here: 678 * while pcap_open_live() definitely sets to to non-zero value, 679 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 680 * do not consider upgrading immediately 681 */ 682 if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K)) 683 is_snap = 1; 684 else 685 is_snap = 0; 686 687 if (is_snap == 0) { 688 /* 689 * We're setting first filter and it doesn't look like 690 * setting snaplen. We're probably using bpf directly. 691 * Upgrade immediately. 692 */ 693 need_upgrade = 1; 694 } else { 695 /* 696 * Do not require upgrade by first BIOCSETF 697 * (used to set snaplen) by pcap_open_live(). 698 */ 699 700 if (--d->bd_writer == 0) { 701 /* 702 * First snaplen filter has already 703 * been set. This is probably catch-all 704 * filter 705 */ 706 need_upgrade = 1; 707 } 708 } 709 710 CTR5(KTR_NET, 711 "%s: filter function set by pid %d, " 712 "bd_writer counter %d, snap %d upgrade %d", 713 __func__, d->bd_pid, d->bd_writer, 714 is_snap, need_upgrade); 715 716 return (need_upgrade); 717 } 718 719 /* 720 * Add d to the list of active bp filters. 721 * Reuqires bpf_attachd() to be called before 722 */ 723 static void 724 bpf_upgraded(struct bpf_d *d) 725 { 726 struct bpf_if *bp; 727 728 BPF_LOCK_ASSERT(); 729 730 bp = d->bd_bif; 731 732 /* 733 * Filter can be set several times without specifying interface. 734 * Mark d as reader and exit. 735 */ 736 if (bp == NULL) { 737 BPFD_LOCK(d); 738 d->bd_writer = 0; 739 BPFD_UNLOCK(d); 740 return; 741 } 742 743 BPFIF_WLOCK(bp); 744 BPFD_LOCK(d); 745 746 /* Remove from writers-only list */ 747 LIST_REMOVE(d, bd_next); 748 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 749 /* Mark d as reader */ 750 d->bd_writer = 0; 751 752 BPFD_UNLOCK(d); 753 BPFIF_WUNLOCK(bp); 754 755 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid); 756 757 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 758 } 759 760 /* 761 * Detach a file from its interface. 762 */ 763 static void 764 bpf_detachd(struct bpf_d *d) 765 { 766 BPF_LOCK(); 767 bpf_detachd_locked(d); 768 BPF_UNLOCK(); 769 } 770 771 static void 772 bpf_detachd_locked(struct bpf_d *d) 773 { 774 int error; 775 struct bpf_if *bp; 776 struct ifnet *ifp; 777 778 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 779 780 BPF_LOCK_ASSERT(); 781 782 /* Check if descriptor is attached */ 783 if ((bp = d->bd_bif) == NULL) 784 return; 785 786 BPFIF_WLOCK(bp); 787 BPFD_LOCK(d); 788 789 /* Save bd_writer value */ 790 error = d->bd_writer; 791 792 /* 793 * Remove d from the interface's descriptor list. 794 */ 795 LIST_REMOVE(d, bd_next); 796 797 ifp = bp->bif_ifp; 798 d->bd_bif = NULL; 799 BPFD_UNLOCK(d); 800 BPFIF_WUNLOCK(bp); 801 802 bpf_bpfd_cnt--; 803 804 /* Call event handler iff d is attached */ 805 if (error == 0) 806 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 807 808 /* 809 * Check if this descriptor had requested promiscuous mode. 810 * If so, turn it off. 811 */ 812 if (d->bd_promisc) { 813 d->bd_promisc = 0; 814 CURVNET_SET(ifp->if_vnet); 815 error = ifpromisc(ifp, 0); 816 CURVNET_RESTORE(); 817 if (error != 0 && error != ENXIO) { 818 /* 819 * ENXIO can happen if a pccard is unplugged 820 * Something is really wrong if we were able to put 821 * the driver into promiscuous mode, but can't 822 * take it out. 823 */ 824 if_printf(bp->bif_ifp, 825 "bpf_detach: ifpromisc failed (%d)\n", error); 826 } 827 } 828 } 829 830 /* 831 * Close the descriptor by detaching it from its interface, 832 * deallocating its buffers, and marking it free. 833 */ 834 static void 835 bpf_dtor(void *data) 836 { 837 struct bpf_d *d = data; 838 839 BPFD_LOCK(d); 840 if (d->bd_state == BPF_WAITING) 841 callout_stop(&d->bd_callout); 842 d->bd_state = BPF_IDLE; 843 BPFD_UNLOCK(d); 844 funsetown(&d->bd_sigio); 845 bpf_detachd(d); 846 #ifdef MAC 847 mac_bpfdesc_destroy(d); 848 #endif /* MAC */ 849 seldrain(&d->bd_sel); 850 knlist_destroy(&d->bd_sel.si_note); 851 callout_drain(&d->bd_callout); 852 bpf_freed(d); 853 free(d, M_BPF); 854 } 855 856 /* 857 * Open ethernet device. Returns ENXIO for illegal minor device number, 858 * EBUSY if file is open by another process. 859 */ 860 /* ARGSUSED */ 861 static int 862 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 863 { 864 struct bpf_d *d; 865 int error, size; 866 867 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 868 error = devfs_set_cdevpriv(d, bpf_dtor); 869 if (error != 0) { 870 free(d, M_BPF); 871 return (error); 872 } 873 874 /* 875 * For historical reasons, perform a one-time initialization call to 876 * the buffer routines, even though we're not yet committed to a 877 * particular buffer method. 878 */ 879 bpf_buffer_init(d); 880 if ((flags & FREAD) == 0) 881 d->bd_writer = 2; 882 d->bd_hbuf_in_use = 0; 883 d->bd_bufmode = BPF_BUFMODE_BUFFER; 884 d->bd_sig = SIGIO; 885 d->bd_direction = BPF_D_INOUT; 886 BPF_PID_REFRESH(d, td); 887 #ifdef MAC 888 mac_bpfdesc_init(d); 889 mac_bpfdesc_create(td->td_ucred, d); 890 #endif 891 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 892 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 893 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 894 895 /* Allocate default buffers */ 896 size = d->bd_bufsize; 897 bpf_buffer_ioctl_sblen(d, &size); 898 899 return (0); 900 } 901 902 /* 903 * bpfread - read next chunk of packets from buffers 904 */ 905 static int 906 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 907 { 908 struct bpf_d *d; 909 int error; 910 int non_block; 911 int timed_out; 912 913 error = devfs_get_cdevpriv((void **)&d); 914 if (error != 0) 915 return (error); 916 917 /* 918 * Restrict application to use a buffer the same size as 919 * as kernel buffers. 920 */ 921 if (uio->uio_resid != d->bd_bufsize) 922 return (EINVAL); 923 924 non_block = ((ioflag & O_NONBLOCK) != 0); 925 926 BPFD_LOCK(d); 927 BPF_PID_REFRESH_CUR(d); 928 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 929 BPFD_UNLOCK(d); 930 return (EOPNOTSUPP); 931 } 932 if (d->bd_state == BPF_WAITING) 933 callout_stop(&d->bd_callout); 934 timed_out = (d->bd_state == BPF_TIMED_OUT); 935 d->bd_state = BPF_IDLE; 936 while (d->bd_hbuf_in_use) { 937 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 938 PRINET|PCATCH, "bd_hbuf", 0); 939 if (error != 0) { 940 BPFD_UNLOCK(d); 941 return (error); 942 } 943 } 944 /* 945 * If the hold buffer is empty, then do a timed sleep, which 946 * ends when the timeout expires or when enough packets 947 * have arrived to fill the store buffer. 948 */ 949 while (d->bd_hbuf == NULL) { 950 if (d->bd_slen != 0) { 951 /* 952 * A packet(s) either arrived since the previous 953 * read or arrived while we were asleep. 954 */ 955 if (d->bd_immediate || non_block || timed_out) { 956 /* 957 * Rotate the buffers and return what's here 958 * if we are in immediate mode, non-blocking 959 * flag is set, or this descriptor timed out. 960 */ 961 ROTATE_BUFFERS(d); 962 break; 963 } 964 } 965 966 /* 967 * No data is available, check to see if the bpf device 968 * is still pointed at a real interface. If not, return 969 * ENXIO so that the userland process knows to rebind 970 * it before using it again. 971 */ 972 if (d->bd_bif == NULL) { 973 BPFD_UNLOCK(d); 974 return (ENXIO); 975 } 976 977 if (non_block) { 978 BPFD_UNLOCK(d); 979 return (EWOULDBLOCK); 980 } 981 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 982 "bpf", d->bd_rtout); 983 if (error == EINTR || error == ERESTART) { 984 BPFD_UNLOCK(d); 985 return (error); 986 } 987 if (error == EWOULDBLOCK) { 988 /* 989 * On a timeout, return what's in the buffer, 990 * which may be nothing. If there is something 991 * in the store buffer, we can rotate the buffers. 992 */ 993 if (d->bd_hbuf) 994 /* 995 * We filled up the buffer in between 996 * getting the timeout and arriving 997 * here, so we don't need to rotate. 998 */ 999 break; 1000 1001 if (d->bd_slen == 0) { 1002 BPFD_UNLOCK(d); 1003 return (0); 1004 } 1005 ROTATE_BUFFERS(d); 1006 break; 1007 } 1008 } 1009 /* 1010 * At this point, we know we have something in the hold slot. 1011 */ 1012 d->bd_hbuf_in_use = 1; 1013 BPFD_UNLOCK(d); 1014 1015 /* 1016 * Move data from hold buffer into user space. 1017 * We know the entire buffer is transferred since 1018 * we checked above that the read buffer is bpf_bufsize bytes. 1019 * 1020 * We do not have to worry about simultaneous reads because 1021 * we waited for sole access to the hold buffer above. 1022 */ 1023 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1024 1025 BPFD_LOCK(d); 1026 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1027 d->bd_fbuf = d->bd_hbuf; 1028 d->bd_hbuf = NULL; 1029 d->bd_hlen = 0; 1030 bpf_buf_reclaimed(d); 1031 d->bd_hbuf_in_use = 0; 1032 wakeup(&d->bd_hbuf_in_use); 1033 BPFD_UNLOCK(d); 1034 1035 return (error); 1036 } 1037 1038 /* 1039 * If there are processes sleeping on this descriptor, wake them up. 1040 */ 1041 static __inline void 1042 bpf_wakeup(struct bpf_d *d) 1043 { 1044 1045 BPFD_LOCK_ASSERT(d); 1046 if (d->bd_state == BPF_WAITING) { 1047 callout_stop(&d->bd_callout); 1048 d->bd_state = BPF_IDLE; 1049 } 1050 wakeup(d); 1051 if (d->bd_async && d->bd_sig && d->bd_sigio) 1052 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1053 1054 selwakeuppri(&d->bd_sel, PRINET); 1055 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1056 } 1057 1058 static void 1059 bpf_timed_out(void *arg) 1060 { 1061 struct bpf_d *d = (struct bpf_d *)arg; 1062 1063 BPFD_LOCK_ASSERT(d); 1064 1065 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) 1066 return; 1067 if (d->bd_state == BPF_WAITING) { 1068 d->bd_state = BPF_TIMED_OUT; 1069 if (d->bd_slen != 0) 1070 bpf_wakeup(d); 1071 } 1072 } 1073 1074 static int 1075 bpf_ready(struct bpf_d *d) 1076 { 1077 1078 BPFD_LOCK_ASSERT(d); 1079 1080 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1081 return (1); 1082 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1083 d->bd_slen != 0) 1084 return (1); 1085 return (0); 1086 } 1087 1088 static int 1089 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1090 { 1091 struct bpf_d *d; 1092 struct ifnet *ifp; 1093 struct mbuf *m, *mc; 1094 struct sockaddr dst; 1095 int error, hlen; 1096 1097 error = devfs_get_cdevpriv((void **)&d); 1098 if (error != 0) 1099 return (error); 1100 1101 BPF_PID_REFRESH_CUR(d); 1102 d->bd_wcount++; 1103 /* XXX: locking required */ 1104 if (d->bd_bif == NULL) { 1105 d->bd_wdcount++; 1106 return (ENXIO); 1107 } 1108 1109 ifp = d->bd_bif->bif_ifp; 1110 1111 if ((ifp->if_flags & IFF_UP) == 0) { 1112 d->bd_wdcount++; 1113 return (ENETDOWN); 1114 } 1115 1116 if (uio->uio_resid == 0) { 1117 d->bd_wdcount++; 1118 return (0); 1119 } 1120 1121 bzero(&dst, sizeof(dst)); 1122 m = NULL; 1123 hlen = 0; 1124 /* XXX: bpf_movein() can sleep */ 1125 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 1126 &m, &dst, &hlen, d->bd_wfilter); 1127 if (error) { 1128 d->bd_wdcount++; 1129 return (error); 1130 } 1131 d->bd_wfcount++; 1132 if (d->bd_hdrcmplt) 1133 dst.sa_family = pseudo_AF_HDRCMPLT; 1134 1135 if (d->bd_feedback) { 1136 mc = m_dup(m, M_NOWAIT); 1137 if (mc != NULL) 1138 mc->m_pkthdr.rcvif = ifp; 1139 /* Set M_PROMISC for outgoing packets to be discarded. */ 1140 if (d->bd_direction == BPF_D_INOUT) 1141 m->m_flags |= M_PROMISC; 1142 } else 1143 mc = NULL; 1144 1145 m->m_pkthdr.len -= hlen; 1146 m->m_len -= hlen; 1147 m->m_data += hlen; /* XXX */ 1148 1149 CURVNET_SET(ifp->if_vnet); 1150 #ifdef MAC 1151 BPFD_LOCK(d); 1152 mac_bpfdesc_create_mbuf(d, m); 1153 if (mc != NULL) 1154 mac_bpfdesc_create_mbuf(d, mc); 1155 BPFD_UNLOCK(d); 1156 #endif 1157 1158 error = (*ifp->if_output)(ifp, m, &dst, NULL); 1159 if (error) 1160 d->bd_wdcount++; 1161 1162 if (mc != NULL) { 1163 if (error == 0) 1164 (*ifp->if_input)(ifp, mc); 1165 else 1166 m_freem(mc); 1167 } 1168 CURVNET_RESTORE(); 1169 1170 return (error); 1171 } 1172 1173 /* 1174 * Reset a descriptor by flushing its packet buffer and clearing the receive 1175 * and drop counts. This is doable for kernel-only buffers, but with 1176 * zero-copy buffers, we can't write to (or rotate) buffers that are 1177 * currently owned by userspace. It would be nice if we could encapsulate 1178 * this logic in the buffer code rather than here. 1179 */ 1180 static void 1181 reset_d(struct bpf_d *d) 1182 { 1183 1184 BPFD_LOCK_ASSERT(d); 1185 1186 while (d->bd_hbuf_in_use) 1187 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1188 "bd_hbuf", 0); 1189 if ((d->bd_hbuf != NULL) && 1190 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1191 /* Free the hold buffer. */ 1192 d->bd_fbuf = d->bd_hbuf; 1193 d->bd_hbuf = NULL; 1194 d->bd_hlen = 0; 1195 bpf_buf_reclaimed(d); 1196 } 1197 if (bpf_canwritebuf(d)) 1198 d->bd_slen = 0; 1199 d->bd_rcount = 0; 1200 d->bd_dcount = 0; 1201 d->bd_fcount = 0; 1202 d->bd_wcount = 0; 1203 d->bd_wfcount = 0; 1204 d->bd_wdcount = 0; 1205 d->bd_zcopy = 0; 1206 } 1207 1208 /* 1209 * FIONREAD Check for read packet available. 1210 * BIOCGBLEN Get buffer len [for read()]. 1211 * BIOCSETF Set read filter. 1212 * BIOCSETFNR Set read filter without resetting descriptor. 1213 * BIOCSETWF Set write filter. 1214 * BIOCFLUSH Flush read packet buffer. 1215 * BIOCPROMISC Put interface into promiscuous mode. 1216 * BIOCGDLT Get link layer type. 1217 * BIOCGETIF Get interface name. 1218 * BIOCSETIF Set interface. 1219 * BIOCSRTIMEOUT Set read timeout. 1220 * BIOCGRTIMEOUT Get read timeout. 1221 * BIOCGSTATS Get packet stats. 1222 * BIOCIMMEDIATE Set immediate mode. 1223 * BIOCVERSION Get filter language version. 1224 * BIOCGHDRCMPLT Get "header already complete" flag 1225 * BIOCSHDRCMPLT Set "header already complete" flag 1226 * BIOCGDIRECTION Get packet direction flag 1227 * BIOCSDIRECTION Set packet direction flag 1228 * BIOCGTSTAMP Get time stamp format and resolution. 1229 * BIOCSTSTAMP Set time stamp format and resolution. 1230 * BIOCLOCK Set "locked" flag 1231 * BIOCFEEDBACK Set packet feedback mode. 1232 * BIOCSETZBUF Set current zero-copy buffer locations. 1233 * BIOCGETZMAX Get maximum zero-copy buffer size. 1234 * BIOCROTZBUF Force rotation of zero-copy buffer 1235 * BIOCSETBUFMODE Set buffer mode. 1236 * BIOCGETBUFMODE Get current buffer mode. 1237 */ 1238 /* ARGSUSED */ 1239 static int 1240 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1241 struct thread *td) 1242 { 1243 struct bpf_d *d; 1244 int error; 1245 1246 error = devfs_get_cdevpriv((void **)&d); 1247 if (error != 0) 1248 return (error); 1249 1250 /* 1251 * Refresh PID associated with this descriptor. 1252 */ 1253 BPFD_LOCK(d); 1254 BPF_PID_REFRESH(d, td); 1255 if (d->bd_state == BPF_WAITING) 1256 callout_stop(&d->bd_callout); 1257 d->bd_state = BPF_IDLE; 1258 BPFD_UNLOCK(d); 1259 1260 if (d->bd_locked == 1) { 1261 switch (cmd) { 1262 case BIOCGBLEN: 1263 case BIOCFLUSH: 1264 case BIOCGDLT: 1265 case BIOCGDLTLIST: 1266 #ifdef COMPAT_FREEBSD32 1267 case BIOCGDLTLIST32: 1268 #endif 1269 case BIOCGETIF: 1270 case BIOCGRTIMEOUT: 1271 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1272 case BIOCGRTIMEOUT32: 1273 #endif 1274 case BIOCGSTATS: 1275 case BIOCVERSION: 1276 case BIOCGRSIG: 1277 case BIOCGHDRCMPLT: 1278 case BIOCSTSTAMP: 1279 case BIOCFEEDBACK: 1280 case FIONREAD: 1281 case BIOCLOCK: 1282 case BIOCSRTIMEOUT: 1283 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1284 case BIOCSRTIMEOUT32: 1285 #endif 1286 case BIOCIMMEDIATE: 1287 case TIOCGPGRP: 1288 case BIOCROTZBUF: 1289 break; 1290 default: 1291 return (EPERM); 1292 } 1293 } 1294 #ifdef COMPAT_FREEBSD32 1295 /* 1296 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1297 * that it will get 32-bit packet headers. 1298 */ 1299 switch (cmd) { 1300 case BIOCSETF32: 1301 case BIOCSETFNR32: 1302 case BIOCSETWF32: 1303 case BIOCGDLTLIST32: 1304 case BIOCGRTIMEOUT32: 1305 case BIOCSRTIMEOUT32: 1306 BPFD_LOCK(d); 1307 d->bd_compat32 = 1; 1308 BPFD_UNLOCK(d); 1309 } 1310 #endif 1311 1312 CURVNET_SET(TD_TO_VNET(td)); 1313 switch (cmd) { 1314 1315 default: 1316 error = EINVAL; 1317 break; 1318 1319 /* 1320 * Check for read packet available. 1321 */ 1322 case FIONREAD: 1323 { 1324 int n; 1325 1326 BPFD_LOCK(d); 1327 n = d->bd_slen; 1328 while (d->bd_hbuf_in_use) 1329 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1330 PRINET, "bd_hbuf", 0); 1331 if (d->bd_hbuf) 1332 n += d->bd_hlen; 1333 BPFD_UNLOCK(d); 1334 1335 *(int *)addr = n; 1336 break; 1337 } 1338 1339 /* 1340 * Get buffer len [for read()]. 1341 */ 1342 case BIOCGBLEN: 1343 BPFD_LOCK(d); 1344 *(u_int *)addr = d->bd_bufsize; 1345 BPFD_UNLOCK(d); 1346 break; 1347 1348 /* 1349 * Set buffer length. 1350 */ 1351 case BIOCSBLEN: 1352 error = bpf_ioctl_sblen(d, (u_int *)addr); 1353 break; 1354 1355 /* 1356 * Set link layer read filter. 1357 */ 1358 case BIOCSETF: 1359 case BIOCSETFNR: 1360 case BIOCSETWF: 1361 #ifdef COMPAT_FREEBSD32 1362 case BIOCSETF32: 1363 case BIOCSETFNR32: 1364 case BIOCSETWF32: 1365 #endif 1366 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1367 break; 1368 1369 /* 1370 * Flush read packet buffer. 1371 */ 1372 case BIOCFLUSH: 1373 BPFD_LOCK(d); 1374 reset_d(d); 1375 BPFD_UNLOCK(d); 1376 break; 1377 1378 /* 1379 * Put interface into promiscuous mode. 1380 */ 1381 case BIOCPROMISC: 1382 if (d->bd_bif == NULL) { 1383 /* 1384 * No interface attached yet. 1385 */ 1386 error = EINVAL; 1387 break; 1388 } 1389 if (d->bd_promisc == 0) { 1390 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1391 if (error == 0) 1392 d->bd_promisc = 1; 1393 } 1394 break; 1395 1396 /* 1397 * Get current data link type. 1398 */ 1399 case BIOCGDLT: 1400 BPF_LOCK(); 1401 if (d->bd_bif == NULL) 1402 error = EINVAL; 1403 else 1404 *(u_int *)addr = d->bd_bif->bif_dlt; 1405 BPF_UNLOCK(); 1406 break; 1407 1408 /* 1409 * Get a list of supported data link types. 1410 */ 1411 #ifdef COMPAT_FREEBSD32 1412 case BIOCGDLTLIST32: 1413 { 1414 struct bpf_dltlist32 *list32; 1415 struct bpf_dltlist dltlist; 1416 1417 list32 = (struct bpf_dltlist32 *)addr; 1418 dltlist.bfl_len = list32->bfl_len; 1419 dltlist.bfl_list = PTRIN(list32->bfl_list); 1420 BPF_LOCK(); 1421 if (d->bd_bif == NULL) 1422 error = EINVAL; 1423 else { 1424 error = bpf_getdltlist(d, &dltlist); 1425 if (error == 0) 1426 list32->bfl_len = dltlist.bfl_len; 1427 } 1428 BPF_UNLOCK(); 1429 break; 1430 } 1431 #endif 1432 1433 case BIOCGDLTLIST: 1434 BPF_LOCK(); 1435 if (d->bd_bif == NULL) 1436 error = EINVAL; 1437 else 1438 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1439 BPF_UNLOCK(); 1440 break; 1441 1442 /* 1443 * Set data link type. 1444 */ 1445 case BIOCSDLT: 1446 BPF_LOCK(); 1447 if (d->bd_bif == NULL) 1448 error = EINVAL; 1449 else 1450 error = bpf_setdlt(d, *(u_int *)addr); 1451 BPF_UNLOCK(); 1452 break; 1453 1454 /* 1455 * Get interface name. 1456 */ 1457 case BIOCGETIF: 1458 BPF_LOCK(); 1459 if (d->bd_bif == NULL) 1460 error = EINVAL; 1461 else { 1462 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1463 struct ifreq *const ifr = (struct ifreq *)addr; 1464 1465 strlcpy(ifr->ifr_name, ifp->if_xname, 1466 sizeof(ifr->ifr_name)); 1467 } 1468 BPF_UNLOCK(); 1469 break; 1470 1471 /* 1472 * Set interface. 1473 */ 1474 case BIOCSETIF: 1475 BPF_LOCK(); 1476 error = bpf_setif(d, (struct ifreq *)addr); 1477 BPF_UNLOCK(); 1478 break; 1479 1480 /* 1481 * Set read timeout. 1482 */ 1483 case BIOCSRTIMEOUT: 1484 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1485 case BIOCSRTIMEOUT32: 1486 #endif 1487 { 1488 struct timeval *tv = (struct timeval *)addr; 1489 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1490 struct timeval32 *tv32; 1491 struct timeval tv64; 1492 1493 if (cmd == BIOCSRTIMEOUT32) { 1494 tv32 = (struct timeval32 *)addr; 1495 tv = &tv64; 1496 tv->tv_sec = tv32->tv_sec; 1497 tv->tv_usec = tv32->tv_usec; 1498 } else 1499 #endif 1500 tv = (struct timeval *)addr; 1501 1502 /* 1503 * Subtract 1 tick from tvtohz() since this isn't 1504 * a one-shot timer. 1505 */ 1506 if ((error = itimerfix(tv)) == 0) 1507 d->bd_rtout = tvtohz(tv) - 1; 1508 break; 1509 } 1510 1511 /* 1512 * Get read timeout. 1513 */ 1514 case BIOCGRTIMEOUT: 1515 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1516 case BIOCGRTIMEOUT32: 1517 #endif 1518 { 1519 struct timeval *tv; 1520 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1521 struct timeval32 *tv32; 1522 struct timeval tv64; 1523 1524 if (cmd == BIOCGRTIMEOUT32) 1525 tv = &tv64; 1526 else 1527 #endif 1528 tv = (struct timeval *)addr; 1529 1530 tv->tv_sec = d->bd_rtout / hz; 1531 tv->tv_usec = (d->bd_rtout % hz) * tick; 1532 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1533 if (cmd == BIOCGRTIMEOUT32) { 1534 tv32 = (struct timeval32 *)addr; 1535 tv32->tv_sec = tv->tv_sec; 1536 tv32->tv_usec = tv->tv_usec; 1537 } 1538 #endif 1539 1540 break; 1541 } 1542 1543 /* 1544 * Get packet stats. 1545 */ 1546 case BIOCGSTATS: 1547 { 1548 struct bpf_stat *bs = (struct bpf_stat *)addr; 1549 1550 /* XXXCSJP overflow */ 1551 bs->bs_recv = d->bd_rcount; 1552 bs->bs_drop = d->bd_dcount; 1553 break; 1554 } 1555 1556 /* 1557 * Set immediate mode. 1558 */ 1559 case BIOCIMMEDIATE: 1560 BPFD_LOCK(d); 1561 d->bd_immediate = *(u_int *)addr; 1562 BPFD_UNLOCK(d); 1563 break; 1564 1565 case BIOCVERSION: 1566 { 1567 struct bpf_version *bv = (struct bpf_version *)addr; 1568 1569 bv->bv_major = BPF_MAJOR_VERSION; 1570 bv->bv_minor = BPF_MINOR_VERSION; 1571 break; 1572 } 1573 1574 /* 1575 * Get "header already complete" flag 1576 */ 1577 case BIOCGHDRCMPLT: 1578 BPFD_LOCK(d); 1579 *(u_int *)addr = d->bd_hdrcmplt; 1580 BPFD_UNLOCK(d); 1581 break; 1582 1583 /* 1584 * Set "header already complete" flag 1585 */ 1586 case BIOCSHDRCMPLT: 1587 BPFD_LOCK(d); 1588 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1589 BPFD_UNLOCK(d); 1590 break; 1591 1592 /* 1593 * Get packet direction flag 1594 */ 1595 case BIOCGDIRECTION: 1596 BPFD_LOCK(d); 1597 *(u_int *)addr = d->bd_direction; 1598 BPFD_UNLOCK(d); 1599 break; 1600 1601 /* 1602 * Set packet direction flag 1603 */ 1604 case BIOCSDIRECTION: 1605 { 1606 u_int direction; 1607 1608 direction = *(u_int *)addr; 1609 switch (direction) { 1610 case BPF_D_IN: 1611 case BPF_D_INOUT: 1612 case BPF_D_OUT: 1613 BPFD_LOCK(d); 1614 d->bd_direction = direction; 1615 BPFD_UNLOCK(d); 1616 break; 1617 default: 1618 error = EINVAL; 1619 } 1620 } 1621 break; 1622 1623 /* 1624 * Get packet timestamp format and resolution. 1625 */ 1626 case BIOCGTSTAMP: 1627 BPFD_LOCK(d); 1628 *(u_int *)addr = d->bd_tstamp; 1629 BPFD_UNLOCK(d); 1630 break; 1631 1632 /* 1633 * Set packet timestamp format and resolution. 1634 */ 1635 case BIOCSTSTAMP: 1636 { 1637 u_int func; 1638 1639 func = *(u_int *)addr; 1640 if (BPF_T_VALID(func)) 1641 d->bd_tstamp = func; 1642 else 1643 error = EINVAL; 1644 } 1645 break; 1646 1647 case BIOCFEEDBACK: 1648 BPFD_LOCK(d); 1649 d->bd_feedback = *(u_int *)addr; 1650 BPFD_UNLOCK(d); 1651 break; 1652 1653 case BIOCLOCK: 1654 BPFD_LOCK(d); 1655 d->bd_locked = 1; 1656 BPFD_UNLOCK(d); 1657 break; 1658 1659 case FIONBIO: /* Non-blocking I/O */ 1660 break; 1661 1662 case FIOASYNC: /* Send signal on receive packets */ 1663 BPFD_LOCK(d); 1664 d->bd_async = *(int *)addr; 1665 BPFD_UNLOCK(d); 1666 break; 1667 1668 case FIOSETOWN: 1669 /* 1670 * XXX: Add some sort of locking here? 1671 * fsetown() can sleep. 1672 */ 1673 error = fsetown(*(int *)addr, &d->bd_sigio); 1674 break; 1675 1676 case FIOGETOWN: 1677 BPFD_LOCK(d); 1678 *(int *)addr = fgetown(&d->bd_sigio); 1679 BPFD_UNLOCK(d); 1680 break; 1681 1682 /* This is deprecated, FIOSETOWN should be used instead. */ 1683 case TIOCSPGRP: 1684 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1685 break; 1686 1687 /* This is deprecated, FIOGETOWN should be used instead. */ 1688 case TIOCGPGRP: 1689 *(int *)addr = -fgetown(&d->bd_sigio); 1690 break; 1691 1692 case BIOCSRSIG: /* Set receive signal */ 1693 { 1694 u_int sig; 1695 1696 sig = *(u_int *)addr; 1697 1698 if (sig >= NSIG) 1699 error = EINVAL; 1700 else { 1701 BPFD_LOCK(d); 1702 d->bd_sig = sig; 1703 BPFD_UNLOCK(d); 1704 } 1705 break; 1706 } 1707 case BIOCGRSIG: 1708 BPFD_LOCK(d); 1709 *(u_int *)addr = d->bd_sig; 1710 BPFD_UNLOCK(d); 1711 break; 1712 1713 case BIOCGETBUFMODE: 1714 BPFD_LOCK(d); 1715 *(u_int *)addr = d->bd_bufmode; 1716 BPFD_UNLOCK(d); 1717 break; 1718 1719 case BIOCSETBUFMODE: 1720 /* 1721 * Allow the buffering mode to be changed as long as we 1722 * haven't yet committed to a particular mode. Our 1723 * definition of commitment, for now, is whether or not a 1724 * buffer has been allocated or an interface attached, since 1725 * that's the point where things get tricky. 1726 */ 1727 switch (*(u_int *)addr) { 1728 case BPF_BUFMODE_BUFFER: 1729 break; 1730 1731 case BPF_BUFMODE_ZBUF: 1732 if (bpf_zerocopy_enable) 1733 break; 1734 /* FALLSTHROUGH */ 1735 1736 default: 1737 CURVNET_RESTORE(); 1738 return (EINVAL); 1739 } 1740 1741 BPFD_LOCK(d); 1742 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1743 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1744 BPFD_UNLOCK(d); 1745 CURVNET_RESTORE(); 1746 return (EBUSY); 1747 } 1748 d->bd_bufmode = *(u_int *)addr; 1749 BPFD_UNLOCK(d); 1750 break; 1751 1752 case BIOCGETZMAX: 1753 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1754 break; 1755 1756 case BIOCSETZBUF: 1757 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1758 break; 1759 1760 case BIOCROTZBUF: 1761 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1762 break; 1763 } 1764 CURVNET_RESTORE(); 1765 return (error); 1766 } 1767 1768 /* 1769 * Set d's packet filter program to fp. If this file already has a filter, 1770 * free it and replace it. Returns EINVAL for bogus requests. 1771 * 1772 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls 1773 * since reading d->bd_bif can't be protected by d or interface lock due to 1774 * lock order. 1775 * 1776 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses 1777 * interface read lock to read all filers. 1778 * 1779 */ 1780 static int 1781 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1782 { 1783 #ifdef COMPAT_FREEBSD32 1784 struct bpf_program fp_swab; 1785 struct bpf_program32 *fp32; 1786 #endif 1787 struct bpf_insn *fcode, *old; 1788 #ifdef BPF_JITTER 1789 bpf_jit_filter *jfunc, *ofunc; 1790 #endif 1791 size_t size; 1792 u_int flen; 1793 int need_upgrade; 1794 1795 #ifdef COMPAT_FREEBSD32 1796 switch (cmd) { 1797 case BIOCSETF32: 1798 case BIOCSETWF32: 1799 case BIOCSETFNR32: 1800 fp32 = (struct bpf_program32 *)fp; 1801 fp_swab.bf_len = fp32->bf_len; 1802 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1803 fp = &fp_swab; 1804 switch (cmd) { 1805 case BIOCSETF32: 1806 cmd = BIOCSETF; 1807 break; 1808 case BIOCSETWF32: 1809 cmd = BIOCSETWF; 1810 break; 1811 } 1812 break; 1813 } 1814 #endif 1815 1816 fcode = NULL; 1817 #ifdef BPF_JITTER 1818 jfunc = ofunc = NULL; 1819 #endif 1820 need_upgrade = 0; 1821 1822 /* 1823 * Check new filter validness before acquiring any locks. 1824 * Allocate memory for new filter, if needed. 1825 */ 1826 flen = fp->bf_len; 1827 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1828 return (EINVAL); 1829 size = flen * sizeof(*fp->bf_insns); 1830 if (size > 0) { 1831 /* We're setting up new filter. Copy and check actual data. */ 1832 fcode = malloc(size, M_BPF, M_WAITOK); 1833 if (copyin(fp->bf_insns, fcode, size) != 0 || 1834 !bpf_validate(fcode, flen)) { 1835 free(fcode, M_BPF); 1836 return (EINVAL); 1837 } 1838 #ifdef BPF_JITTER 1839 /* Filter is copied inside fcode and is perfectly valid. */ 1840 jfunc = bpf_jitter(fcode, flen); 1841 #endif 1842 } 1843 1844 BPF_LOCK(); 1845 1846 /* 1847 * Set up new filter. 1848 * Protect filter change by interface lock. 1849 * Additionally, we are protected by global lock here. 1850 */ 1851 if (d->bd_bif != NULL) 1852 BPFIF_WLOCK(d->bd_bif); 1853 BPFD_LOCK(d); 1854 if (cmd == BIOCSETWF) { 1855 old = d->bd_wfilter; 1856 d->bd_wfilter = fcode; 1857 } else { 1858 old = d->bd_rfilter; 1859 d->bd_rfilter = fcode; 1860 #ifdef BPF_JITTER 1861 ofunc = d->bd_bfilter; 1862 d->bd_bfilter = jfunc; 1863 #endif 1864 if (cmd == BIOCSETF) 1865 reset_d(d); 1866 1867 need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen); 1868 } 1869 BPFD_UNLOCK(d); 1870 if (d->bd_bif != NULL) 1871 BPFIF_WUNLOCK(d->bd_bif); 1872 if (old != NULL) 1873 free(old, M_BPF); 1874 #ifdef BPF_JITTER 1875 if (ofunc != NULL) 1876 bpf_destroy_jit_filter(ofunc); 1877 #endif 1878 1879 /* Move d to active readers list. */ 1880 if (need_upgrade != 0) 1881 bpf_upgraded(d); 1882 1883 BPF_UNLOCK(); 1884 return (0); 1885 } 1886 1887 /* 1888 * Detach a file from its current interface (if attached at all) and attach 1889 * to the interface indicated by the name stored in ifr. 1890 * Return an errno or 0. 1891 */ 1892 static int 1893 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1894 { 1895 struct bpf_if *bp; 1896 struct ifnet *theywant; 1897 1898 BPF_LOCK_ASSERT(); 1899 1900 theywant = ifunit(ifr->ifr_name); 1901 if (theywant == NULL || theywant->if_bpf == NULL) 1902 return (ENXIO); 1903 1904 bp = theywant->if_bpf; 1905 1906 /* Check if interface is not being detached from BPF */ 1907 BPFIF_RLOCK(bp); 1908 if (bp->bif_flags & BPFIF_FLAG_DYING) { 1909 BPFIF_RUNLOCK(bp); 1910 return (ENXIO); 1911 } 1912 BPFIF_RUNLOCK(bp); 1913 1914 /* 1915 * Behavior here depends on the buffering model. If we're using 1916 * kernel memory buffers, then we can allocate them here. If we're 1917 * using zero-copy, then the user process must have registered 1918 * buffers by the time we get here. If not, return an error. 1919 */ 1920 switch (d->bd_bufmode) { 1921 case BPF_BUFMODE_BUFFER: 1922 case BPF_BUFMODE_ZBUF: 1923 if (d->bd_sbuf == NULL) 1924 return (EINVAL); 1925 break; 1926 1927 default: 1928 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1929 } 1930 if (bp != d->bd_bif) 1931 bpf_attachd(d, bp); 1932 BPFD_LOCK(d); 1933 reset_d(d); 1934 BPFD_UNLOCK(d); 1935 return (0); 1936 } 1937 1938 /* 1939 * Support for select() and poll() system calls 1940 * 1941 * Return true iff the specific operation will not block indefinitely. 1942 * Otherwise, return false but make a note that a selwakeup() must be done. 1943 */ 1944 static int 1945 bpfpoll(struct cdev *dev, int events, struct thread *td) 1946 { 1947 struct bpf_d *d; 1948 int revents; 1949 1950 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 1951 return (events & 1952 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 1953 1954 /* 1955 * Refresh PID associated with this descriptor. 1956 */ 1957 revents = events & (POLLOUT | POLLWRNORM); 1958 BPFD_LOCK(d); 1959 BPF_PID_REFRESH(d, td); 1960 if (events & (POLLIN | POLLRDNORM)) { 1961 if (bpf_ready(d)) 1962 revents |= events & (POLLIN | POLLRDNORM); 1963 else { 1964 selrecord(td, &d->bd_sel); 1965 /* Start the read timeout if necessary. */ 1966 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1967 callout_reset(&d->bd_callout, d->bd_rtout, 1968 bpf_timed_out, d); 1969 d->bd_state = BPF_WAITING; 1970 } 1971 } 1972 } 1973 BPFD_UNLOCK(d); 1974 return (revents); 1975 } 1976 1977 /* 1978 * Support for kevent() system call. Register EVFILT_READ filters and 1979 * reject all others. 1980 */ 1981 int 1982 bpfkqfilter(struct cdev *dev, struct knote *kn) 1983 { 1984 struct bpf_d *d; 1985 1986 if (devfs_get_cdevpriv((void **)&d) != 0 || 1987 kn->kn_filter != EVFILT_READ) 1988 return (1); 1989 1990 /* 1991 * Refresh PID associated with this descriptor. 1992 */ 1993 BPFD_LOCK(d); 1994 BPF_PID_REFRESH_CUR(d); 1995 kn->kn_fop = &bpfread_filtops; 1996 kn->kn_hook = d; 1997 knlist_add(&d->bd_sel.si_note, kn, 1); 1998 BPFD_UNLOCK(d); 1999 2000 return (0); 2001 } 2002 2003 static void 2004 filt_bpfdetach(struct knote *kn) 2005 { 2006 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2007 2008 knlist_remove(&d->bd_sel.si_note, kn, 0); 2009 } 2010 2011 static int 2012 filt_bpfread(struct knote *kn, long hint) 2013 { 2014 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2015 int ready; 2016 2017 BPFD_LOCK_ASSERT(d); 2018 ready = bpf_ready(d); 2019 if (ready) { 2020 kn->kn_data = d->bd_slen; 2021 while (d->bd_hbuf_in_use) 2022 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 2023 PRINET, "bd_hbuf", 0); 2024 if (d->bd_hbuf) 2025 kn->kn_data += d->bd_hlen; 2026 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2027 callout_reset(&d->bd_callout, d->bd_rtout, 2028 bpf_timed_out, d); 2029 d->bd_state = BPF_WAITING; 2030 } 2031 2032 return (ready); 2033 } 2034 2035 #define BPF_TSTAMP_NONE 0 2036 #define BPF_TSTAMP_FAST 1 2037 #define BPF_TSTAMP_NORMAL 2 2038 #define BPF_TSTAMP_EXTERN 3 2039 2040 static int 2041 bpf_ts_quality(int tstype) 2042 { 2043 2044 if (tstype == BPF_T_NONE) 2045 return (BPF_TSTAMP_NONE); 2046 if ((tstype & BPF_T_FAST) != 0) 2047 return (BPF_TSTAMP_FAST); 2048 2049 return (BPF_TSTAMP_NORMAL); 2050 } 2051 2052 static int 2053 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2054 { 2055 struct m_tag *tag; 2056 int quality; 2057 2058 quality = bpf_ts_quality(tstype); 2059 if (quality == BPF_TSTAMP_NONE) 2060 return (quality); 2061 2062 if (m != NULL) { 2063 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2064 if (tag != NULL) { 2065 *bt = *(struct bintime *)(tag + 1); 2066 return (BPF_TSTAMP_EXTERN); 2067 } 2068 } 2069 if (quality == BPF_TSTAMP_NORMAL) 2070 binuptime(bt); 2071 else 2072 getbinuptime(bt); 2073 2074 return (quality); 2075 } 2076 2077 /* 2078 * Incoming linkage from device drivers. Process the packet pkt, of length 2079 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2080 * by each process' filter, and if accepted, stashed into the corresponding 2081 * buffer. 2082 */ 2083 void 2084 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2085 { 2086 struct bintime bt; 2087 struct bpf_d *d; 2088 #ifdef BPF_JITTER 2089 bpf_jit_filter *bf; 2090 #endif 2091 u_int slen; 2092 int gottime; 2093 2094 gottime = BPF_TSTAMP_NONE; 2095 2096 BPFIF_RLOCK(bp); 2097 2098 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2099 /* 2100 * We are not using any locks for d here because: 2101 * 1) any filter change is protected by interface 2102 * write lock 2103 * 2) destroying/detaching d is protected by interface 2104 * write lock, too 2105 */ 2106 2107 /* XXX: Do not protect counter for the sake of performance. */ 2108 ++d->bd_rcount; 2109 /* 2110 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no 2111 * way for the caller to indiciate to us whether this packet 2112 * is inbound or outbound. In the bpf_mtap() routines, we use 2113 * the interface pointers on the mbuf to figure it out. 2114 */ 2115 #ifdef BPF_JITTER 2116 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2117 if (bf != NULL) 2118 slen = (*(bf->func))(pkt, pktlen, pktlen); 2119 else 2120 #endif 2121 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2122 if (slen != 0) { 2123 /* 2124 * Filter matches. Let's to acquire write lock. 2125 */ 2126 BPFD_LOCK(d); 2127 2128 d->bd_fcount++; 2129 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2130 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL); 2131 #ifdef MAC 2132 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2133 #endif 2134 catchpacket(d, pkt, pktlen, slen, 2135 bpf_append_bytes, &bt); 2136 BPFD_UNLOCK(d); 2137 } 2138 } 2139 BPFIF_RUNLOCK(bp); 2140 } 2141 2142 #define BPF_CHECK_DIRECTION(d, r, i) \ 2143 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2144 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2145 2146 /* 2147 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2148 * Locking model is explained in bpf_tap(). 2149 */ 2150 void 2151 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2152 { 2153 struct bintime bt; 2154 struct bpf_d *d; 2155 #ifdef BPF_JITTER 2156 bpf_jit_filter *bf; 2157 #endif 2158 u_int pktlen, slen; 2159 int gottime; 2160 2161 /* Skip outgoing duplicate packets. */ 2162 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2163 m->m_flags &= ~M_PROMISC; 2164 return; 2165 } 2166 2167 pktlen = m_length(m, NULL); 2168 gottime = BPF_TSTAMP_NONE; 2169 2170 BPFIF_RLOCK(bp); 2171 2172 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2173 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2174 continue; 2175 ++d->bd_rcount; 2176 #ifdef BPF_JITTER 2177 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2178 /* XXX We cannot handle multiple mbufs. */ 2179 if (bf != NULL && m->m_next == NULL) 2180 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); 2181 else 2182 #endif 2183 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2184 if (slen != 0) { 2185 BPFD_LOCK(d); 2186 2187 d->bd_fcount++; 2188 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2189 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2190 #ifdef MAC 2191 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2192 #endif 2193 catchpacket(d, (u_char *)m, pktlen, slen, 2194 bpf_append_mbuf, &bt); 2195 BPFD_UNLOCK(d); 2196 } 2197 } 2198 BPFIF_RUNLOCK(bp); 2199 } 2200 2201 /* 2202 * Incoming linkage from device drivers, when packet is in 2203 * an mbuf chain and to be prepended by a contiguous header. 2204 */ 2205 void 2206 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2207 { 2208 struct bintime bt; 2209 struct mbuf mb; 2210 struct bpf_d *d; 2211 u_int pktlen, slen; 2212 int gottime; 2213 2214 /* Skip outgoing duplicate packets. */ 2215 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2216 m->m_flags &= ~M_PROMISC; 2217 return; 2218 } 2219 2220 pktlen = m_length(m, NULL); 2221 /* 2222 * Craft on-stack mbuf suitable for passing to bpf_filter. 2223 * Note that we cut corners here; we only setup what's 2224 * absolutely needed--this mbuf should never go anywhere else. 2225 */ 2226 mb.m_next = m; 2227 mb.m_data = data; 2228 mb.m_len = dlen; 2229 pktlen += dlen; 2230 2231 gottime = BPF_TSTAMP_NONE; 2232 2233 BPFIF_RLOCK(bp); 2234 2235 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2236 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2237 continue; 2238 ++d->bd_rcount; 2239 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2240 if (slen != 0) { 2241 BPFD_LOCK(d); 2242 2243 d->bd_fcount++; 2244 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2245 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2246 #ifdef MAC 2247 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2248 #endif 2249 catchpacket(d, (u_char *)&mb, pktlen, slen, 2250 bpf_append_mbuf, &bt); 2251 BPFD_UNLOCK(d); 2252 } 2253 } 2254 BPFIF_RUNLOCK(bp); 2255 } 2256 2257 #undef BPF_CHECK_DIRECTION 2258 2259 #undef BPF_TSTAMP_NONE 2260 #undef BPF_TSTAMP_FAST 2261 #undef BPF_TSTAMP_NORMAL 2262 #undef BPF_TSTAMP_EXTERN 2263 2264 static int 2265 bpf_hdrlen(struct bpf_d *d) 2266 { 2267 int hdrlen; 2268 2269 hdrlen = d->bd_bif->bif_hdrlen; 2270 #ifndef BURN_BRIDGES 2271 if (d->bd_tstamp == BPF_T_NONE || 2272 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2273 #ifdef COMPAT_FREEBSD32 2274 if (d->bd_compat32) 2275 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2276 else 2277 #endif 2278 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2279 else 2280 #endif 2281 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2282 #ifdef COMPAT_FREEBSD32 2283 if (d->bd_compat32) 2284 hdrlen = BPF_WORDALIGN32(hdrlen); 2285 else 2286 #endif 2287 hdrlen = BPF_WORDALIGN(hdrlen); 2288 2289 return (hdrlen - d->bd_bif->bif_hdrlen); 2290 } 2291 2292 static void 2293 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2294 { 2295 struct bintime bt2; 2296 struct timeval tsm; 2297 struct timespec tsn; 2298 2299 if ((tstype & BPF_T_MONOTONIC) == 0) { 2300 bt2 = *bt; 2301 bintime_add(&bt2, &boottimebin); 2302 bt = &bt2; 2303 } 2304 switch (BPF_T_FORMAT(tstype)) { 2305 case BPF_T_MICROTIME: 2306 bintime2timeval(bt, &tsm); 2307 ts->bt_sec = tsm.tv_sec; 2308 ts->bt_frac = tsm.tv_usec; 2309 break; 2310 case BPF_T_NANOTIME: 2311 bintime2timespec(bt, &tsn); 2312 ts->bt_sec = tsn.tv_sec; 2313 ts->bt_frac = tsn.tv_nsec; 2314 break; 2315 case BPF_T_BINTIME: 2316 ts->bt_sec = bt->sec; 2317 ts->bt_frac = bt->frac; 2318 break; 2319 } 2320 } 2321 2322 /* 2323 * Move the packet data from interface memory (pkt) into the 2324 * store buffer. "cpfn" is the routine called to do the actual data 2325 * transfer. bcopy is passed in to copy contiguous chunks, while 2326 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2327 * pkt is really an mbuf. 2328 */ 2329 static void 2330 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2331 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2332 struct bintime *bt) 2333 { 2334 struct bpf_xhdr hdr; 2335 #ifndef BURN_BRIDGES 2336 struct bpf_hdr hdr_old; 2337 #ifdef COMPAT_FREEBSD32 2338 struct bpf_hdr32 hdr32_old; 2339 #endif 2340 #endif 2341 int caplen, curlen, hdrlen, totlen; 2342 int do_wakeup = 0; 2343 int do_timestamp; 2344 int tstype; 2345 2346 BPFD_LOCK_ASSERT(d); 2347 2348 /* 2349 * Detect whether user space has released a buffer back to us, and if 2350 * so, move it from being a hold buffer to a free buffer. This may 2351 * not be the best place to do it (for example, we might only want to 2352 * run this check if we need the space), but for now it's a reliable 2353 * spot to do it. 2354 */ 2355 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2356 while (d->bd_hbuf_in_use) 2357 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 2358 PRINET, "bd_hbuf", 0); 2359 d->bd_fbuf = d->bd_hbuf; 2360 d->bd_hbuf = NULL; 2361 d->bd_hlen = 0; 2362 bpf_buf_reclaimed(d); 2363 } 2364 2365 /* 2366 * Figure out how many bytes to move. If the packet is 2367 * greater or equal to the snapshot length, transfer that 2368 * much. Otherwise, transfer the whole packet (unless 2369 * we hit the buffer size limit). 2370 */ 2371 hdrlen = bpf_hdrlen(d); 2372 totlen = hdrlen + min(snaplen, pktlen); 2373 if (totlen > d->bd_bufsize) 2374 totlen = d->bd_bufsize; 2375 2376 /* 2377 * Round up the end of the previous packet to the next longword. 2378 * 2379 * Drop the packet if there's no room and no hope of room 2380 * If the packet would overflow the storage buffer or the storage 2381 * buffer is considered immutable by the buffer model, try to rotate 2382 * the buffer and wakeup pending processes. 2383 */ 2384 #ifdef COMPAT_FREEBSD32 2385 if (d->bd_compat32) 2386 curlen = BPF_WORDALIGN32(d->bd_slen); 2387 else 2388 #endif 2389 curlen = BPF_WORDALIGN(d->bd_slen); 2390 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2391 if (d->bd_fbuf == NULL) { 2392 /* 2393 * There's no room in the store buffer, and no 2394 * prospect of room, so drop the packet. Notify the 2395 * buffer model. 2396 */ 2397 bpf_buffull(d); 2398 ++d->bd_dcount; 2399 return; 2400 } 2401 while (d->bd_hbuf_in_use) 2402 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 2403 PRINET, "bd_hbuf", 0); 2404 ROTATE_BUFFERS(d); 2405 do_wakeup = 1; 2406 curlen = 0; 2407 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2408 /* 2409 * Immediate mode is set, or the read timeout has already 2410 * expired during a select call. A packet arrived, so the 2411 * reader should be woken up. 2412 */ 2413 do_wakeup = 1; 2414 caplen = totlen - hdrlen; 2415 tstype = d->bd_tstamp; 2416 do_timestamp = tstype != BPF_T_NONE; 2417 #ifndef BURN_BRIDGES 2418 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2419 struct bpf_ts ts; 2420 if (do_timestamp) 2421 bpf_bintime2ts(bt, &ts, tstype); 2422 #ifdef COMPAT_FREEBSD32 2423 if (d->bd_compat32) { 2424 bzero(&hdr32_old, sizeof(hdr32_old)); 2425 if (do_timestamp) { 2426 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2427 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2428 } 2429 hdr32_old.bh_datalen = pktlen; 2430 hdr32_old.bh_hdrlen = hdrlen; 2431 hdr32_old.bh_caplen = caplen; 2432 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2433 sizeof(hdr32_old)); 2434 goto copy; 2435 } 2436 #endif 2437 bzero(&hdr_old, sizeof(hdr_old)); 2438 if (do_timestamp) { 2439 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2440 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2441 } 2442 hdr_old.bh_datalen = pktlen; 2443 hdr_old.bh_hdrlen = hdrlen; 2444 hdr_old.bh_caplen = caplen; 2445 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2446 sizeof(hdr_old)); 2447 goto copy; 2448 } 2449 #endif 2450 2451 /* 2452 * Append the bpf header. Note we append the actual header size, but 2453 * move forward the length of the header plus padding. 2454 */ 2455 bzero(&hdr, sizeof(hdr)); 2456 if (do_timestamp) 2457 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2458 hdr.bh_datalen = pktlen; 2459 hdr.bh_hdrlen = hdrlen; 2460 hdr.bh_caplen = caplen; 2461 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2462 2463 /* 2464 * Copy the packet data into the store buffer and update its length. 2465 */ 2466 #ifndef BURN_BRIDGES 2467 copy: 2468 #endif 2469 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2470 d->bd_slen = curlen + totlen; 2471 2472 if (do_wakeup) 2473 bpf_wakeup(d); 2474 } 2475 2476 /* 2477 * Free buffers currently in use by a descriptor. 2478 * Called on close. 2479 */ 2480 static void 2481 bpf_freed(struct bpf_d *d) 2482 { 2483 2484 /* 2485 * We don't need to lock out interrupts since this descriptor has 2486 * been detached from its interface and it yet hasn't been marked 2487 * free. 2488 */ 2489 bpf_free(d); 2490 if (d->bd_rfilter != NULL) { 2491 free((caddr_t)d->bd_rfilter, M_BPF); 2492 #ifdef BPF_JITTER 2493 if (d->bd_bfilter != NULL) 2494 bpf_destroy_jit_filter(d->bd_bfilter); 2495 #endif 2496 } 2497 if (d->bd_wfilter != NULL) 2498 free((caddr_t)d->bd_wfilter, M_BPF); 2499 mtx_destroy(&d->bd_lock); 2500 } 2501 2502 /* 2503 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2504 * fixed size of the link header (variable length headers not yet supported). 2505 */ 2506 void 2507 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2508 { 2509 2510 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2511 } 2512 2513 /* 2514 * Attach an interface to bpf. ifp is a pointer to the structure 2515 * defining the interface to be attached, dlt is the link layer type, 2516 * and hdrlen is the fixed size of the link header (variable length 2517 * headers are not yet supporrted). 2518 */ 2519 void 2520 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2521 { 2522 struct bpf_if *bp; 2523 2524 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 2525 if (bp == NULL) 2526 panic("bpfattach"); 2527 2528 LIST_INIT(&bp->bif_dlist); 2529 LIST_INIT(&bp->bif_wlist); 2530 bp->bif_ifp = ifp; 2531 bp->bif_dlt = dlt; 2532 rw_init(&bp->bif_lock, "bpf interface lock"); 2533 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 2534 *driverp = bp; 2535 2536 BPF_LOCK(); 2537 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2538 BPF_UNLOCK(); 2539 2540 bp->bif_hdrlen = hdrlen; 2541 2542 if (bootverbose) 2543 if_printf(ifp, "bpf attached\n"); 2544 } 2545 2546 /* 2547 * Detach bpf from an interface. This involves detaching each descriptor 2548 * associated with the interface. Notify each descriptor as it's detached 2549 * so that any sleepers wake up and get ENXIO. 2550 */ 2551 void 2552 bpfdetach(struct ifnet *ifp) 2553 { 2554 struct bpf_if *bp, *bp_temp; 2555 struct bpf_d *d; 2556 int ndetached; 2557 2558 ndetached = 0; 2559 2560 BPF_LOCK(); 2561 /* Find all bpf_if struct's which reference ifp and detach them. */ 2562 LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2563 if (ifp != bp->bif_ifp) 2564 continue; 2565 2566 LIST_REMOVE(bp, bif_next); 2567 /* Add to to-be-freed list */ 2568 LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next); 2569 2570 ndetached++; 2571 /* 2572 * Delay freeing bp till interface is detached 2573 * and all routes through this interface are removed. 2574 * Mark bp as detached to restrict new consumers. 2575 */ 2576 BPFIF_WLOCK(bp); 2577 bp->bif_flags |= BPFIF_FLAG_DYING; 2578 BPFIF_WUNLOCK(bp); 2579 2580 CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p", 2581 __func__, bp->bif_dlt, bp, ifp); 2582 2583 /* Free common descriptors */ 2584 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 2585 bpf_detachd_locked(d); 2586 BPFD_LOCK(d); 2587 bpf_wakeup(d); 2588 BPFD_UNLOCK(d); 2589 } 2590 2591 /* Free writer-only descriptors */ 2592 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) { 2593 bpf_detachd_locked(d); 2594 BPFD_LOCK(d); 2595 bpf_wakeup(d); 2596 BPFD_UNLOCK(d); 2597 } 2598 } 2599 BPF_UNLOCK(); 2600 2601 #ifdef INVARIANTS 2602 if (ndetached == 0) 2603 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 2604 #endif 2605 } 2606 2607 /* 2608 * Interface departure handler. 2609 * Note departure event does not guarantee interface is going down. 2610 * Interface renaming is currently done via departure/arrival event set. 2611 * 2612 * Departure handled is called after all routes pointing to 2613 * given interface are removed and interface is in down state 2614 * restricting any packets to be sent/received. We assume it is now safe 2615 * to free data allocated by BPF. 2616 */ 2617 static void 2618 bpf_ifdetach(void *arg __unused, struct ifnet *ifp) 2619 { 2620 struct bpf_if *bp, *bp_temp; 2621 int nmatched = 0; 2622 2623 BPF_LOCK(); 2624 /* 2625 * Find matching entries in free list. 2626 * Nothing should be found if bpfdetach() was not called. 2627 */ 2628 LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) { 2629 if (ifp != bp->bif_ifp) 2630 continue; 2631 2632 CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p", 2633 __func__, bp, ifp); 2634 2635 LIST_REMOVE(bp, bif_next); 2636 2637 rw_destroy(&bp->bif_lock); 2638 free(bp, M_BPF); 2639 2640 nmatched++; 2641 } 2642 BPF_UNLOCK(); 2643 2644 /* 2645 * Note that we cannot zero other pointers to 2646 * custom DLTs possibly used by given interface. 2647 */ 2648 if (nmatched != 0) 2649 ifp->if_bpf = NULL; 2650 } 2651 2652 /* 2653 * Get a list of available data link type of the interface. 2654 */ 2655 static int 2656 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2657 { 2658 int n, error; 2659 struct ifnet *ifp; 2660 struct bpf_if *bp; 2661 2662 BPF_LOCK_ASSERT(); 2663 2664 ifp = d->bd_bif->bif_ifp; 2665 n = 0; 2666 error = 0; 2667 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2668 if (bp->bif_ifp != ifp) 2669 continue; 2670 if (bfl->bfl_list != NULL) { 2671 if (n >= bfl->bfl_len) 2672 return (ENOMEM); 2673 error = copyout(&bp->bif_dlt, 2674 bfl->bfl_list + n, sizeof(u_int)); 2675 } 2676 n++; 2677 } 2678 bfl->bfl_len = n; 2679 return (error); 2680 } 2681 2682 /* 2683 * Set the data link type of a BPF instance. 2684 */ 2685 static int 2686 bpf_setdlt(struct bpf_d *d, u_int dlt) 2687 { 2688 int error, opromisc; 2689 struct ifnet *ifp; 2690 struct bpf_if *bp; 2691 2692 BPF_LOCK_ASSERT(); 2693 2694 if (d->bd_bif->bif_dlt == dlt) 2695 return (0); 2696 ifp = d->bd_bif->bif_ifp; 2697 2698 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2699 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2700 break; 2701 } 2702 2703 if (bp != NULL) { 2704 opromisc = d->bd_promisc; 2705 bpf_attachd(d, bp); 2706 BPFD_LOCK(d); 2707 reset_d(d); 2708 BPFD_UNLOCK(d); 2709 if (opromisc) { 2710 error = ifpromisc(bp->bif_ifp, 1); 2711 if (error) 2712 if_printf(bp->bif_ifp, 2713 "bpf_setdlt: ifpromisc failed (%d)\n", 2714 error); 2715 else 2716 d->bd_promisc = 1; 2717 } 2718 } 2719 return (bp == NULL ? EINVAL : 0); 2720 } 2721 2722 static void 2723 bpf_drvinit(void *unused) 2724 { 2725 struct cdev *dev; 2726 2727 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2728 LIST_INIT(&bpf_iflist); 2729 LIST_INIT(&bpf_freelist); 2730 2731 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2732 /* For compatibility */ 2733 make_dev_alias(dev, "bpf0"); 2734 2735 /* Register interface departure handler */ 2736 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER( 2737 ifnet_departure_event, bpf_ifdetach, NULL, 2738 EVENTHANDLER_PRI_ANY); 2739 } 2740 2741 /* 2742 * Zero out the various packet counters associated with all of the bpf 2743 * descriptors. At some point, we will probably want to get a bit more 2744 * granular and allow the user to specify descriptors to be zeroed. 2745 */ 2746 static void 2747 bpf_zero_counters(void) 2748 { 2749 struct bpf_if *bp; 2750 struct bpf_d *bd; 2751 2752 BPF_LOCK(); 2753 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2754 BPFIF_RLOCK(bp); 2755 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2756 BPFD_LOCK(bd); 2757 bd->bd_rcount = 0; 2758 bd->bd_dcount = 0; 2759 bd->bd_fcount = 0; 2760 bd->bd_wcount = 0; 2761 bd->bd_wfcount = 0; 2762 bd->bd_zcopy = 0; 2763 BPFD_UNLOCK(bd); 2764 } 2765 BPFIF_RUNLOCK(bp); 2766 } 2767 BPF_UNLOCK(); 2768 } 2769 2770 /* 2771 * Fill filter statistics 2772 */ 2773 static void 2774 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2775 { 2776 2777 bzero(d, sizeof(*d)); 2778 BPFD_LOCK_ASSERT(bd); 2779 d->bd_structsize = sizeof(*d); 2780 /* XXX: reading should be protected by global lock */ 2781 d->bd_immediate = bd->bd_immediate; 2782 d->bd_promisc = bd->bd_promisc; 2783 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2784 d->bd_direction = bd->bd_direction; 2785 d->bd_feedback = bd->bd_feedback; 2786 d->bd_async = bd->bd_async; 2787 d->bd_rcount = bd->bd_rcount; 2788 d->bd_dcount = bd->bd_dcount; 2789 d->bd_fcount = bd->bd_fcount; 2790 d->bd_sig = bd->bd_sig; 2791 d->bd_slen = bd->bd_slen; 2792 d->bd_hlen = bd->bd_hlen; 2793 d->bd_bufsize = bd->bd_bufsize; 2794 d->bd_pid = bd->bd_pid; 2795 strlcpy(d->bd_ifname, 2796 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2797 d->bd_locked = bd->bd_locked; 2798 d->bd_wcount = bd->bd_wcount; 2799 d->bd_wdcount = bd->bd_wdcount; 2800 d->bd_wfcount = bd->bd_wfcount; 2801 d->bd_zcopy = bd->bd_zcopy; 2802 d->bd_bufmode = bd->bd_bufmode; 2803 } 2804 2805 /* 2806 * Handle `netstat -B' stats request 2807 */ 2808 static int 2809 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2810 { 2811 static const struct xbpf_d zerostats; 2812 struct xbpf_d *xbdbuf, *xbd, tempstats; 2813 int index, error; 2814 struct bpf_if *bp; 2815 struct bpf_d *bd; 2816 2817 /* 2818 * XXX This is not technically correct. It is possible for non 2819 * privileged users to open bpf devices. It would make sense 2820 * if the users who opened the devices were able to retrieve 2821 * the statistics for them, too. 2822 */ 2823 error = priv_check(req->td, PRIV_NET_BPF); 2824 if (error) 2825 return (error); 2826 /* 2827 * Check to see if the user is requesting that the counters be 2828 * zeroed out. Explicitly check that the supplied data is zeroed, 2829 * as we aren't allowing the user to set the counters currently. 2830 */ 2831 if (req->newptr != NULL) { 2832 if (req->newlen != sizeof(tempstats)) 2833 return (EINVAL); 2834 memset(&tempstats, 0, sizeof(tempstats)); 2835 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2836 if (error) 2837 return (error); 2838 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2839 return (EINVAL); 2840 bpf_zero_counters(); 2841 return (0); 2842 } 2843 if (req->oldptr == NULL) 2844 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2845 if (bpf_bpfd_cnt == 0) 2846 return (SYSCTL_OUT(req, 0, 0)); 2847 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2848 BPF_LOCK(); 2849 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2850 BPF_UNLOCK(); 2851 free(xbdbuf, M_BPF); 2852 return (ENOMEM); 2853 } 2854 index = 0; 2855 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2856 BPFIF_RLOCK(bp); 2857 /* Send writers-only first */ 2858 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2859 xbd = &xbdbuf[index++]; 2860 BPFD_LOCK(bd); 2861 bpfstats_fill_xbpf(xbd, bd); 2862 BPFD_UNLOCK(bd); 2863 } 2864 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2865 xbd = &xbdbuf[index++]; 2866 BPFD_LOCK(bd); 2867 bpfstats_fill_xbpf(xbd, bd); 2868 BPFD_UNLOCK(bd); 2869 } 2870 BPFIF_RUNLOCK(bp); 2871 } 2872 BPF_UNLOCK(); 2873 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2874 free(xbdbuf, M_BPF); 2875 return (error); 2876 } 2877 2878 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2879 2880 #else /* !DEV_BPF && !NETGRAPH_BPF */ 2881 /* 2882 * NOP stubs to allow bpf-using drivers to load and function. 2883 * 2884 * A 'better' implementation would allow the core bpf functionality 2885 * to be loaded at runtime. 2886 */ 2887 static struct bpf_if bp_null; 2888 2889 void 2890 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2891 { 2892 } 2893 2894 void 2895 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2896 { 2897 } 2898 2899 void 2900 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2901 { 2902 } 2903 2904 void 2905 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2906 { 2907 2908 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2909 } 2910 2911 void 2912 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2913 { 2914 2915 *driverp = &bp_null; 2916 } 2917 2918 void 2919 bpfdetach(struct ifnet *ifp) 2920 { 2921 } 2922 2923 u_int 2924 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 2925 { 2926 return -1; /* "no filter" behaviour */ 2927 } 2928 2929 int 2930 bpf_validate(const struct bpf_insn *f, int len) 2931 { 2932 return 0; /* false */ 2933 } 2934 2935 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 2936