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/if_dl.h> 73 #include <net/bpf.h> 74 #include <net/bpf_buffer.h> 75 #ifdef BPF_JITTER 76 #include <net/bpf_jitter.h> 77 #endif 78 #include <net/bpf_zerocopy.h> 79 #include <net/bpfdesc.h> 80 #include <net/route.h> 81 #include <net/vnet.h> 82 83 #include <netinet/in.h> 84 #include <netinet/if_ether.h> 85 #include <sys/kernel.h> 86 #include <sys/sysctl.h> 87 88 #include <net80211/ieee80211_freebsd.h> 89 90 #include <security/mac/mac_framework.h> 91 92 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 93 94 struct bpf_if { 95 #define bif_next bif_ext.bif_next 96 #define bif_dlist bif_ext.bif_dlist 97 struct bpf_if_ext bif_ext; /* public members */ 98 u_int bif_dlt; /* link layer type */ 99 u_int bif_hdrlen; /* length of link header */ 100 struct ifnet *bif_ifp; /* corresponding interface */ 101 struct rwlock bif_lock; /* interface lock */ 102 LIST_HEAD(, bpf_d) bif_wlist; /* writer-only list */ 103 int bif_flags; /* Interface flags */ 104 }; 105 106 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); 107 108 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 109 110 #define PRINET 26 /* interruptible */ 111 112 #define SIZEOF_BPF_HDR(type) \ 113 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 114 115 #ifdef COMPAT_FREEBSD32 116 #include <sys/mount.h> 117 #include <compat/freebsd32/freebsd32.h> 118 #define BPF_ALIGNMENT32 sizeof(int32_t) 119 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1)) 120 121 #ifndef BURN_BRIDGES 122 /* 123 * 32-bit version of structure prepended to each packet. We use this header 124 * instead of the standard one for 32-bit streams. We mark the a stream as 125 * 32-bit the first time we see a 32-bit compat ioctl request. 126 */ 127 struct bpf_hdr32 { 128 struct timeval32 bh_tstamp; /* time stamp */ 129 uint32_t bh_caplen; /* length of captured portion */ 130 uint32_t bh_datalen; /* original length of packet */ 131 uint16_t bh_hdrlen; /* length of bpf header (this struct 132 plus alignment padding) */ 133 }; 134 #endif 135 136 struct bpf_program32 { 137 u_int bf_len; 138 uint32_t bf_insns; 139 }; 140 141 struct bpf_dltlist32 { 142 u_int bfl_len; 143 u_int bfl_list; 144 }; 145 146 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 147 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 148 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 149 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 150 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 151 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 152 #endif 153 154 /* 155 * bpf_iflist is a list of BPF interface structures, each corresponding to a 156 * specific DLT. The same network interface might have several BPF interface 157 * structures registered by different layers in the stack (i.e., 802.11 158 * frames, ethernet frames, etc). 159 */ 160 static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist; 161 static struct mtx bpf_mtx; /* bpf global lock */ 162 static int bpf_bpfd_cnt; 163 164 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 165 static void bpf_detachd(struct bpf_d *); 166 static void bpf_detachd_locked(struct bpf_d *); 167 static void bpf_freed(struct bpf_d *); 168 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 169 struct sockaddr *, int *, struct bpf_d *); 170 static int bpf_setif(struct bpf_d *, struct ifreq *); 171 static void bpf_timed_out(void *); 172 static __inline void 173 bpf_wakeup(struct bpf_d *); 174 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 175 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 176 struct bintime *); 177 static void reset_d(struct bpf_d *); 178 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 179 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 180 static int bpf_setdlt(struct bpf_d *, u_int); 181 static void filt_bpfdetach(struct knote *); 182 static int filt_bpfread(struct knote *, long); 183 static void bpf_drvinit(void *); 184 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 185 186 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 187 int bpf_maxinsns = BPF_MAXINSNS; 188 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 189 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 190 static int bpf_zerocopy_enable = 0; 191 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 192 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 193 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 194 bpf_stats_sysctl, "bpf statistics portal"); 195 196 static VNET_DEFINE(int, bpf_optimize_writers) = 0; 197 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 198 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RW, 199 &VNET_NAME(bpf_optimize_writers), 0, 200 "Do not send packets until BPF program is set"); 201 202 static d_open_t bpfopen; 203 static d_read_t bpfread; 204 static d_write_t bpfwrite; 205 static d_ioctl_t bpfioctl; 206 static d_poll_t bpfpoll; 207 static d_kqfilter_t bpfkqfilter; 208 209 static struct cdevsw bpf_cdevsw = { 210 .d_version = D_VERSION, 211 .d_open = bpfopen, 212 .d_read = bpfread, 213 .d_write = bpfwrite, 214 .d_ioctl = bpfioctl, 215 .d_poll = bpfpoll, 216 .d_name = "bpf", 217 .d_kqfilter = bpfkqfilter, 218 }; 219 220 static struct filterops bpfread_filtops = { 221 .f_isfd = 1, 222 .f_detach = filt_bpfdetach, 223 .f_event = filt_bpfread, 224 }; 225 226 eventhandler_tag bpf_ifdetach_cookie = NULL; 227 228 /* 229 * LOCKING MODEL USED BY BPF: 230 * Locks: 231 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal, 232 * some global counters and every bpf_if reference. 233 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters. 234 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields 235 * used by bpf_mtap code. 236 * 237 * Lock order: 238 * 239 * Global lock, interface lock, descriptor lock 240 * 241 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2] 242 * working model. In many places (like bpf_detachd) we start with BPF descriptor 243 * (and we need to at least rlock it to get reliable interface pointer). This 244 * gives us potential LOR. As a result, we use global lock to protect from bpf_if 245 * change in every such place. 246 * 247 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and 248 * 3) descriptor main wlock. 249 * Reading bd_bif can be protected by any of these locks, typically global lock. 250 * 251 * Changing read/write BPF filter is protected by the same three locks, 252 * the same applies for reading. 253 * 254 * Sleeping in global lock is not allowed due to bpfdetach() using it. 255 */ 256 257 /* 258 * Wrapper functions for various buffering methods. If the set of buffer 259 * modes expands, we will probably want to introduce a switch data structure 260 * similar to protosw, et. 261 */ 262 static void 263 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 264 u_int len) 265 { 266 267 BPFD_LOCK_ASSERT(d); 268 269 switch (d->bd_bufmode) { 270 case BPF_BUFMODE_BUFFER: 271 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 272 273 case BPF_BUFMODE_ZBUF: 274 d->bd_zcopy++; 275 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 276 277 default: 278 panic("bpf_buf_append_bytes"); 279 } 280 } 281 282 static void 283 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 284 u_int len) 285 { 286 287 BPFD_LOCK_ASSERT(d); 288 289 switch (d->bd_bufmode) { 290 case BPF_BUFMODE_BUFFER: 291 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 292 293 case BPF_BUFMODE_ZBUF: 294 d->bd_zcopy++; 295 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 296 297 default: 298 panic("bpf_buf_append_mbuf"); 299 } 300 } 301 302 /* 303 * This function gets called when the free buffer is re-assigned. 304 */ 305 static void 306 bpf_buf_reclaimed(struct bpf_d *d) 307 { 308 309 BPFD_LOCK_ASSERT(d); 310 311 switch (d->bd_bufmode) { 312 case BPF_BUFMODE_BUFFER: 313 return; 314 315 case BPF_BUFMODE_ZBUF: 316 bpf_zerocopy_buf_reclaimed(d); 317 return; 318 319 default: 320 panic("bpf_buf_reclaimed"); 321 } 322 } 323 324 /* 325 * If the buffer mechanism has a way to decide that a held buffer can be made 326 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 327 * returned if the buffer can be discarded, (0) is returned if it cannot. 328 */ 329 static int 330 bpf_canfreebuf(struct bpf_d *d) 331 { 332 333 BPFD_LOCK_ASSERT(d); 334 335 switch (d->bd_bufmode) { 336 case BPF_BUFMODE_ZBUF: 337 return (bpf_zerocopy_canfreebuf(d)); 338 } 339 return (0); 340 } 341 342 /* 343 * Allow the buffer model to indicate that the current store buffer is 344 * immutable, regardless of the appearance of space. Return (1) if the 345 * buffer is writable, and (0) if not. 346 */ 347 static int 348 bpf_canwritebuf(struct bpf_d *d) 349 { 350 BPFD_LOCK_ASSERT(d); 351 352 switch (d->bd_bufmode) { 353 case BPF_BUFMODE_ZBUF: 354 return (bpf_zerocopy_canwritebuf(d)); 355 } 356 return (1); 357 } 358 359 /* 360 * Notify buffer model that an attempt to write to the store buffer has 361 * resulted in a dropped packet, in which case the buffer may be considered 362 * full. 363 */ 364 static void 365 bpf_buffull(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_buffull(d); 373 break; 374 } 375 } 376 377 /* 378 * Notify the buffer model that a buffer has moved into the hold position. 379 */ 380 void 381 bpf_bufheld(struct bpf_d *d) 382 { 383 384 BPFD_LOCK_ASSERT(d); 385 386 switch (d->bd_bufmode) { 387 case BPF_BUFMODE_ZBUF: 388 bpf_zerocopy_bufheld(d); 389 break; 390 } 391 } 392 393 static void 394 bpf_free(struct bpf_d *d) 395 { 396 397 switch (d->bd_bufmode) { 398 case BPF_BUFMODE_BUFFER: 399 return (bpf_buffer_free(d)); 400 401 case BPF_BUFMODE_ZBUF: 402 return (bpf_zerocopy_free(d)); 403 404 default: 405 panic("bpf_buf_free"); 406 } 407 } 408 409 static int 410 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 411 { 412 413 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 414 return (EOPNOTSUPP); 415 return (bpf_buffer_uiomove(d, buf, len, uio)); 416 } 417 418 static int 419 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 420 { 421 422 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 423 return (EOPNOTSUPP); 424 return (bpf_buffer_ioctl_sblen(d, i)); 425 } 426 427 static int 428 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 429 { 430 431 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 432 return (EOPNOTSUPP); 433 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 434 } 435 436 static int 437 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 438 { 439 440 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 441 return (EOPNOTSUPP); 442 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 443 } 444 445 static int 446 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 447 { 448 449 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 450 return (EOPNOTSUPP); 451 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 452 } 453 454 /* 455 * General BPF functions. 456 */ 457 static int 458 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 459 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) 460 { 461 const struct ieee80211_bpf_params *p; 462 struct ether_header *eh; 463 struct mbuf *m; 464 int error; 465 int len; 466 int hlen; 467 int slen; 468 469 /* 470 * Build a sockaddr based on the data link layer type. 471 * We do this at this level because the ethernet header 472 * is copied directly into the data field of the sockaddr. 473 * In the case of SLIP, there is no header and the packet 474 * is forwarded as is. 475 * Also, we are careful to leave room at the front of the mbuf 476 * for the link level header. 477 */ 478 switch (linktype) { 479 480 case DLT_SLIP: 481 sockp->sa_family = AF_INET; 482 hlen = 0; 483 break; 484 485 case DLT_EN10MB: 486 sockp->sa_family = AF_UNSPEC; 487 /* XXX Would MAXLINKHDR be better? */ 488 hlen = ETHER_HDR_LEN; 489 break; 490 491 case DLT_FDDI: 492 sockp->sa_family = AF_IMPLINK; 493 hlen = 0; 494 break; 495 496 case DLT_RAW: 497 sockp->sa_family = AF_UNSPEC; 498 hlen = 0; 499 break; 500 501 case DLT_NULL: 502 /* 503 * null interface types require a 4 byte pseudo header which 504 * corresponds to the address family of the packet. 505 */ 506 sockp->sa_family = AF_UNSPEC; 507 hlen = 4; 508 break; 509 510 case DLT_ATM_RFC1483: 511 /* 512 * en atm driver requires 4-byte atm pseudo header. 513 * though it isn't standard, vpi:vci needs to be 514 * specified anyway. 515 */ 516 sockp->sa_family = AF_UNSPEC; 517 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 518 break; 519 520 case DLT_PPP: 521 sockp->sa_family = AF_UNSPEC; 522 hlen = 4; /* This should match PPP_HDRLEN */ 523 break; 524 525 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 526 sockp->sa_family = AF_IEEE80211; 527 hlen = 0; 528 break; 529 530 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 531 sockp->sa_family = AF_IEEE80211; 532 sockp->sa_len = 12; /* XXX != 0 */ 533 hlen = sizeof(struct ieee80211_bpf_params); 534 break; 535 536 default: 537 return (EIO); 538 } 539 540 len = uio->uio_resid; 541 if (len < hlen || len - hlen > ifp->if_mtu) 542 return (EMSGSIZE); 543 544 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR); 545 if (m == NULL) 546 return (EIO); 547 m->m_pkthdr.len = m->m_len = len; 548 *mp = m; 549 550 error = uiomove(mtod(m, u_char *), len, uio); 551 if (error) 552 goto bad; 553 554 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 555 if (slen == 0) { 556 error = EPERM; 557 goto bad; 558 } 559 560 /* Check for multicast destination */ 561 switch (linktype) { 562 case DLT_EN10MB: 563 eh = mtod(m, struct ether_header *); 564 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 565 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 566 ETHER_ADDR_LEN) == 0) 567 m->m_flags |= M_BCAST; 568 else 569 m->m_flags |= M_MCAST; 570 } 571 if (d->bd_hdrcmplt == 0) { 572 memcpy(eh->ether_shost, IF_LLADDR(ifp), 573 sizeof(eh->ether_shost)); 574 } 575 break; 576 } 577 578 /* 579 * Make room for link header, and copy it to sockaddr 580 */ 581 if (hlen != 0) { 582 if (sockp->sa_family == AF_IEEE80211) { 583 /* 584 * Collect true length from the parameter header 585 * NB: sockp is known to be zero'd so if we do a 586 * short copy unspecified parameters will be 587 * zero. 588 * NB: packet may not be aligned after stripping 589 * bpf params 590 * XXX check ibp_vers 591 */ 592 p = mtod(m, const struct ieee80211_bpf_params *); 593 hlen = p->ibp_len; 594 if (hlen > sizeof(sockp->sa_data)) { 595 error = EINVAL; 596 goto bad; 597 } 598 } 599 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 600 } 601 *hdrlen = hlen; 602 603 return (0); 604 bad: 605 m_freem(m); 606 return (error); 607 } 608 609 /* 610 * Attach file to the bpf interface, i.e. make d listen on bp. 611 */ 612 static void 613 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 614 { 615 int op_w; 616 617 BPF_LOCK_ASSERT(); 618 619 /* 620 * Save sysctl value to protect from sysctl change 621 * between reads 622 */ 623 op_w = V_bpf_optimize_writers || d->bd_writer; 624 625 if (d->bd_bif != NULL) 626 bpf_detachd_locked(d); 627 /* 628 * Point d at bp, and add d to the interface's list. 629 * Since there are many applications using BPF for 630 * sending raw packets only (dhcpd, cdpd are good examples) 631 * we can delay adding d to the list of active listeners until 632 * some filter is configured. 633 */ 634 635 BPFIF_WLOCK(bp); 636 BPFD_LOCK(d); 637 638 d->bd_bif = bp; 639 640 if (op_w != 0) { 641 /* Add to writers-only list */ 642 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 643 /* 644 * We decrement bd_writer on every filter set operation. 645 * First BIOCSETF is done by pcap_open_live() to set up 646 * snap length. After that appliation usually sets its own filter 647 */ 648 d->bd_writer = 2; 649 } else 650 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 651 652 BPFD_UNLOCK(d); 653 BPFIF_WUNLOCK(bp); 654 655 bpf_bpfd_cnt++; 656 657 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 658 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 659 660 if (op_w == 0) 661 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 662 } 663 664 /* 665 * Check if we need to upgrade our descriptor @d from write-only mode. 666 */ 667 static int 668 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen) 669 { 670 int is_snap, need_upgrade; 671 672 /* 673 * Check if we've already upgraded or new filter is empty. 674 */ 675 if (d->bd_writer == 0 || fcode == NULL) 676 return (0); 677 678 need_upgrade = 0; 679 680 /* 681 * Check if cmd looks like snaplen setting from 682 * pcap_bpf.c:pcap_open_live(). 683 * Note we're not checking .k value here: 684 * while pcap_open_live() definitely sets to to non-zero value, 685 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 686 * do not consider upgrading immediately 687 */ 688 if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K)) 689 is_snap = 1; 690 else 691 is_snap = 0; 692 693 if (is_snap == 0) { 694 /* 695 * We're setting first filter and it doesn't look like 696 * setting snaplen. We're probably using bpf directly. 697 * Upgrade immediately. 698 */ 699 need_upgrade = 1; 700 } else { 701 /* 702 * Do not require upgrade by first BIOCSETF 703 * (used to set snaplen) by pcap_open_live(). 704 */ 705 706 if (--d->bd_writer == 0) { 707 /* 708 * First snaplen filter has already 709 * been set. This is probably catch-all 710 * filter 711 */ 712 need_upgrade = 1; 713 } 714 } 715 716 CTR5(KTR_NET, 717 "%s: filter function set by pid %d, " 718 "bd_writer counter %d, snap %d upgrade %d", 719 __func__, d->bd_pid, d->bd_writer, 720 is_snap, need_upgrade); 721 722 return (need_upgrade); 723 } 724 725 /* 726 * Add d to the list of active bp filters. 727 * Requires bpf_attachd() to be called before. 728 */ 729 static void 730 bpf_upgraded(struct bpf_d *d) 731 { 732 struct bpf_if *bp; 733 734 BPF_LOCK_ASSERT(); 735 736 bp = d->bd_bif; 737 738 /* 739 * Filter can be set several times without specifying interface. 740 * Mark d as reader and exit. 741 */ 742 if (bp == NULL) { 743 BPFD_LOCK(d); 744 d->bd_writer = 0; 745 BPFD_UNLOCK(d); 746 return; 747 } 748 749 BPFIF_WLOCK(bp); 750 BPFD_LOCK(d); 751 752 /* Remove from writers-only list */ 753 LIST_REMOVE(d, bd_next); 754 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 755 /* Mark d as reader */ 756 d->bd_writer = 0; 757 758 BPFD_UNLOCK(d); 759 BPFIF_WUNLOCK(bp); 760 761 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid); 762 763 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 764 } 765 766 /* 767 * Detach a file from its interface. 768 */ 769 static void 770 bpf_detachd(struct bpf_d *d) 771 { 772 BPF_LOCK(); 773 bpf_detachd_locked(d); 774 BPF_UNLOCK(); 775 } 776 777 static void 778 bpf_detachd_locked(struct bpf_d *d) 779 { 780 int error; 781 struct bpf_if *bp; 782 struct ifnet *ifp; 783 784 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 785 786 BPF_LOCK_ASSERT(); 787 788 /* Check if descriptor is attached */ 789 if ((bp = d->bd_bif) == NULL) 790 return; 791 792 BPFIF_WLOCK(bp); 793 BPFD_LOCK(d); 794 795 /* Save bd_writer value */ 796 error = d->bd_writer; 797 798 /* 799 * Remove d from the interface's descriptor list. 800 */ 801 LIST_REMOVE(d, bd_next); 802 803 ifp = bp->bif_ifp; 804 d->bd_bif = NULL; 805 BPFD_UNLOCK(d); 806 BPFIF_WUNLOCK(bp); 807 808 bpf_bpfd_cnt--; 809 810 /* Call event handler iff d is attached */ 811 if (error == 0) 812 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 813 814 /* 815 * Check if this descriptor had requested promiscuous mode. 816 * If so, turn it off. 817 */ 818 if (d->bd_promisc) { 819 d->bd_promisc = 0; 820 CURVNET_SET(ifp->if_vnet); 821 error = ifpromisc(ifp, 0); 822 CURVNET_RESTORE(); 823 if (error != 0 && error != ENXIO) { 824 /* 825 * ENXIO can happen if a pccard is unplugged 826 * Something is really wrong if we were able to put 827 * the driver into promiscuous mode, but can't 828 * take it out. 829 */ 830 if_printf(bp->bif_ifp, 831 "bpf_detach: ifpromisc failed (%d)\n", error); 832 } 833 } 834 } 835 836 /* 837 * Close the descriptor by detaching it from its interface, 838 * deallocating its buffers, and marking it free. 839 */ 840 static void 841 bpf_dtor(void *data) 842 { 843 struct bpf_d *d = data; 844 845 BPFD_LOCK(d); 846 if (d->bd_state == BPF_WAITING) 847 callout_stop(&d->bd_callout); 848 d->bd_state = BPF_IDLE; 849 BPFD_UNLOCK(d); 850 funsetown(&d->bd_sigio); 851 bpf_detachd(d); 852 #ifdef MAC 853 mac_bpfdesc_destroy(d); 854 #endif /* MAC */ 855 seldrain(&d->bd_sel); 856 knlist_destroy(&d->bd_sel.si_note); 857 callout_drain(&d->bd_callout); 858 bpf_freed(d); 859 free(d, M_BPF); 860 } 861 862 /* 863 * Open ethernet device. Returns ENXIO for illegal minor device number, 864 * EBUSY if file is open by another process. 865 */ 866 /* ARGSUSED */ 867 static int 868 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 869 { 870 struct bpf_d *d; 871 int error; 872 873 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 874 error = devfs_set_cdevpriv(d, bpf_dtor); 875 if (error != 0) { 876 free(d, M_BPF); 877 return (error); 878 } 879 880 /* 881 * For historical reasons, perform a one-time initialization call to 882 * the buffer routines, even though we're not yet committed to a 883 * particular buffer method. 884 */ 885 bpf_buffer_init(d); 886 if ((flags & FREAD) == 0) 887 d->bd_writer = 2; 888 d->bd_hbuf_in_use = 0; 889 d->bd_bufmode = BPF_BUFMODE_BUFFER; 890 d->bd_sig = SIGIO; 891 d->bd_direction = BPF_D_INOUT; 892 BPF_PID_REFRESH(d, td); 893 #ifdef MAC 894 mac_bpfdesc_init(d); 895 mac_bpfdesc_create(td->td_ucred, d); 896 #endif 897 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 898 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 899 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 900 901 return (0); 902 } 903 904 /* 905 * bpfread - read next chunk of packets from buffers 906 */ 907 static int 908 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 909 { 910 struct bpf_d *d; 911 int error; 912 int non_block; 913 int timed_out; 914 915 error = devfs_get_cdevpriv((void **)&d); 916 if (error != 0) 917 return (error); 918 919 /* 920 * Restrict application to use a buffer the same size as 921 * as kernel buffers. 922 */ 923 if (uio->uio_resid != d->bd_bufsize) 924 return (EINVAL); 925 926 non_block = ((ioflag & O_NONBLOCK) != 0); 927 928 BPFD_LOCK(d); 929 BPF_PID_REFRESH_CUR(d); 930 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 931 BPFD_UNLOCK(d); 932 return (EOPNOTSUPP); 933 } 934 if (d->bd_state == BPF_WAITING) 935 callout_stop(&d->bd_callout); 936 timed_out = (d->bd_state == BPF_TIMED_OUT); 937 d->bd_state = BPF_IDLE; 938 while (d->bd_hbuf_in_use) { 939 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 940 PRINET|PCATCH, "bd_hbuf", 0); 941 if (error != 0) { 942 BPFD_UNLOCK(d); 943 return (error); 944 } 945 } 946 /* 947 * If the hold buffer is empty, then do a timed sleep, which 948 * ends when the timeout expires or when enough packets 949 * have arrived to fill the store buffer. 950 */ 951 while (d->bd_hbuf == NULL) { 952 if (d->bd_slen != 0) { 953 /* 954 * A packet(s) either arrived since the previous 955 * read or arrived while we were asleep. 956 */ 957 if (d->bd_immediate || non_block || timed_out) { 958 /* 959 * Rotate the buffers and return what's here 960 * if we are in immediate mode, non-blocking 961 * flag is set, or this descriptor timed out. 962 */ 963 ROTATE_BUFFERS(d); 964 break; 965 } 966 } 967 968 /* 969 * No data is available, check to see if the bpf device 970 * is still pointed at a real interface. If not, return 971 * ENXIO so that the userland process knows to rebind 972 * it before using it again. 973 */ 974 if (d->bd_bif == NULL) { 975 BPFD_UNLOCK(d); 976 return (ENXIO); 977 } 978 979 if (non_block) { 980 BPFD_UNLOCK(d); 981 return (EWOULDBLOCK); 982 } 983 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 984 "bpf", d->bd_rtout); 985 if (error == EINTR || error == ERESTART) { 986 BPFD_UNLOCK(d); 987 return (error); 988 } 989 if (error == EWOULDBLOCK) { 990 /* 991 * On a timeout, return what's in the buffer, 992 * which may be nothing. If there is something 993 * in the store buffer, we can rotate the buffers. 994 */ 995 if (d->bd_hbuf) 996 /* 997 * We filled up the buffer in between 998 * getting the timeout and arriving 999 * here, so we don't need to rotate. 1000 */ 1001 break; 1002 1003 if (d->bd_slen == 0) { 1004 BPFD_UNLOCK(d); 1005 return (0); 1006 } 1007 ROTATE_BUFFERS(d); 1008 break; 1009 } 1010 } 1011 /* 1012 * At this point, we know we have something in the hold slot. 1013 */ 1014 d->bd_hbuf_in_use = 1; 1015 BPFD_UNLOCK(d); 1016 1017 /* 1018 * Move data from hold buffer into user space. 1019 * We know the entire buffer is transferred since 1020 * we checked above that the read buffer is bpf_bufsize bytes. 1021 * 1022 * We do not have to worry about simultaneous reads because 1023 * we waited for sole access to the hold buffer above. 1024 */ 1025 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1026 1027 BPFD_LOCK(d); 1028 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1029 d->bd_fbuf = d->bd_hbuf; 1030 d->bd_hbuf = NULL; 1031 d->bd_hlen = 0; 1032 bpf_buf_reclaimed(d); 1033 d->bd_hbuf_in_use = 0; 1034 wakeup(&d->bd_hbuf_in_use); 1035 BPFD_UNLOCK(d); 1036 1037 return (error); 1038 } 1039 1040 /* 1041 * If there are processes sleeping on this descriptor, wake them up. 1042 */ 1043 static __inline void 1044 bpf_wakeup(struct bpf_d *d) 1045 { 1046 1047 BPFD_LOCK_ASSERT(d); 1048 if (d->bd_state == BPF_WAITING) { 1049 callout_stop(&d->bd_callout); 1050 d->bd_state = BPF_IDLE; 1051 } 1052 wakeup(d); 1053 if (d->bd_async && d->bd_sig && d->bd_sigio) 1054 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1055 1056 selwakeuppri(&d->bd_sel, PRINET); 1057 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1058 } 1059 1060 static void 1061 bpf_timed_out(void *arg) 1062 { 1063 struct bpf_d *d = (struct bpf_d *)arg; 1064 1065 BPFD_LOCK_ASSERT(d); 1066 1067 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) 1068 return; 1069 if (d->bd_state == BPF_WAITING) { 1070 d->bd_state = BPF_TIMED_OUT; 1071 if (d->bd_slen != 0) 1072 bpf_wakeup(d); 1073 } 1074 } 1075 1076 static int 1077 bpf_ready(struct bpf_d *d) 1078 { 1079 1080 BPFD_LOCK_ASSERT(d); 1081 1082 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1083 return (1); 1084 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1085 d->bd_slen != 0) 1086 return (1); 1087 return (0); 1088 } 1089 1090 static int 1091 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1092 { 1093 struct bpf_d *d; 1094 struct ifnet *ifp; 1095 struct mbuf *m, *mc; 1096 struct sockaddr dst; 1097 struct route ro; 1098 int error, hlen; 1099 1100 error = devfs_get_cdevpriv((void **)&d); 1101 if (error != 0) 1102 return (error); 1103 1104 BPF_PID_REFRESH_CUR(d); 1105 d->bd_wcount++; 1106 /* XXX: locking required */ 1107 if (d->bd_bif == NULL) { 1108 d->bd_wdcount++; 1109 return (ENXIO); 1110 } 1111 1112 ifp = d->bd_bif->bif_ifp; 1113 1114 if ((ifp->if_flags & IFF_UP) == 0) { 1115 d->bd_wdcount++; 1116 return (ENETDOWN); 1117 } 1118 1119 if (uio->uio_resid == 0) { 1120 d->bd_wdcount++; 1121 return (0); 1122 } 1123 1124 bzero(&dst, sizeof(dst)); 1125 m = NULL; 1126 hlen = 0; 1127 /* XXX: bpf_movein() can sleep */ 1128 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 1129 &m, &dst, &hlen, d); 1130 if (error) { 1131 d->bd_wdcount++; 1132 return (error); 1133 } 1134 d->bd_wfcount++; 1135 if (d->bd_hdrcmplt) 1136 dst.sa_family = pseudo_AF_HDRCMPLT; 1137 1138 if (d->bd_feedback) { 1139 mc = m_dup(m, M_NOWAIT); 1140 if (mc != NULL) 1141 mc->m_pkthdr.rcvif = ifp; 1142 /* Set M_PROMISC for outgoing packets to be discarded. */ 1143 if (d->bd_direction == BPF_D_INOUT) 1144 m->m_flags |= M_PROMISC; 1145 } else 1146 mc = NULL; 1147 1148 m->m_pkthdr.len -= hlen; 1149 m->m_len -= hlen; 1150 m->m_data += hlen; /* XXX */ 1151 1152 CURVNET_SET(ifp->if_vnet); 1153 #ifdef MAC 1154 BPFD_LOCK(d); 1155 mac_bpfdesc_create_mbuf(d, m); 1156 if (mc != NULL) 1157 mac_bpfdesc_create_mbuf(d, mc); 1158 BPFD_UNLOCK(d); 1159 #endif 1160 1161 bzero(&ro, sizeof(ro)); 1162 if (hlen != 0) { 1163 ro.ro_prepend = (u_char *)&dst.sa_data; 1164 ro.ro_plen = hlen; 1165 ro.ro_flags = RT_HAS_HEADER; 1166 } 1167 1168 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1169 if (error) 1170 d->bd_wdcount++; 1171 1172 if (mc != NULL) { 1173 if (error == 0) 1174 (*ifp->if_input)(ifp, mc); 1175 else 1176 m_freem(mc); 1177 } 1178 CURVNET_RESTORE(); 1179 1180 return (error); 1181 } 1182 1183 /* 1184 * Reset a descriptor by flushing its packet buffer and clearing the receive 1185 * and drop counts. This is doable for kernel-only buffers, but with 1186 * zero-copy buffers, we can't write to (or rotate) buffers that are 1187 * currently owned by userspace. It would be nice if we could encapsulate 1188 * this logic in the buffer code rather than here. 1189 */ 1190 static void 1191 reset_d(struct bpf_d *d) 1192 { 1193 1194 BPFD_LOCK_ASSERT(d); 1195 1196 while (d->bd_hbuf_in_use) 1197 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1198 "bd_hbuf", 0); 1199 if ((d->bd_hbuf != NULL) && 1200 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1201 /* Free the hold buffer. */ 1202 d->bd_fbuf = d->bd_hbuf; 1203 d->bd_hbuf = NULL; 1204 d->bd_hlen = 0; 1205 bpf_buf_reclaimed(d); 1206 } 1207 if (bpf_canwritebuf(d)) 1208 d->bd_slen = 0; 1209 d->bd_rcount = 0; 1210 d->bd_dcount = 0; 1211 d->bd_fcount = 0; 1212 d->bd_wcount = 0; 1213 d->bd_wfcount = 0; 1214 d->bd_wdcount = 0; 1215 d->bd_zcopy = 0; 1216 } 1217 1218 /* 1219 * FIONREAD Check for read packet available. 1220 * BIOCGBLEN Get buffer len [for read()]. 1221 * BIOCSETF Set read filter. 1222 * BIOCSETFNR Set read filter without resetting descriptor. 1223 * BIOCSETWF Set write filter. 1224 * BIOCFLUSH Flush read packet buffer. 1225 * BIOCPROMISC Put interface into promiscuous mode. 1226 * BIOCGDLT Get link layer type. 1227 * BIOCGETIF Get interface name. 1228 * BIOCSETIF Set interface. 1229 * BIOCSRTIMEOUT Set read timeout. 1230 * BIOCGRTIMEOUT Get read timeout. 1231 * BIOCGSTATS Get packet stats. 1232 * BIOCIMMEDIATE Set immediate mode. 1233 * BIOCVERSION Get filter language version. 1234 * BIOCGHDRCMPLT Get "header already complete" flag 1235 * BIOCSHDRCMPLT Set "header already complete" flag 1236 * BIOCGDIRECTION Get packet direction flag 1237 * BIOCSDIRECTION Set packet direction flag 1238 * BIOCGTSTAMP Get time stamp format and resolution. 1239 * BIOCSTSTAMP Set time stamp format and resolution. 1240 * BIOCLOCK Set "locked" flag 1241 * BIOCFEEDBACK Set packet feedback mode. 1242 * BIOCSETZBUF Set current zero-copy buffer locations. 1243 * BIOCGETZMAX Get maximum zero-copy buffer size. 1244 * BIOCROTZBUF Force rotation of zero-copy buffer 1245 * BIOCSETBUFMODE Set buffer mode. 1246 * BIOCGETBUFMODE Get current buffer mode. 1247 */ 1248 /* ARGSUSED */ 1249 static int 1250 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1251 struct thread *td) 1252 { 1253 struct bpf_d *d; 1254 int error; 1255 1256 error = devfs_get_cdevpriv((void **)&d); 1257 if (error != 0) 1258 return (error); 1259 1260 /* 1261 * Refresh PID associated with this descriptor. 1262 */ 1263 BPFD_LOCK(d); 1264 BPF_PID_REFRESH(d, td); 1265 if (d->bd_state == BPF_WAITING) 1266 callout_stop(&d->bd_callout); 1267 d->bd_state = BPF_IDLE; 1268 BPFD_UNLOCK(d); 1269 1270 if (d->bd_locked == 1) { 1271 switch (cmd) { 1272 case BIOCGBLEN: 1273 case BIOCFLUSH: 1274 case BIOCGDLT: 1275 case BIOCGDLTLIST: 1276 #ifdef COMPAT_FREEBSD32 1277 case BIOCGDLTLIST32: 1278 #endif 1279 case BIOCGETIF: 1280 case BIOCGRTIMEOUT: 1281 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1282 case BIOCGRTIMEOUT32: 1283 #endif 1284 case BIOCGSTATS: 1285 case BIOCVERSION: 1286 case BIOCGRSIG: 1287 case BIOCGHDRCMPLT: 1288 case BIOCSTSTAMP: 1289 case BIOCFEEDBACK: 1290 case FIONREAD: 1291 case BIOCLOCK: 1292 case BIOCSRTIMEOUT: 1293 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1294 case BIOCSRTIMEOUT32: 1295 #endif 1296 case BIOCIMMEDIATE: 1297 case TIOCGPGRP: 1298 case BIOCROTZBUF: 1299 break; 1300 default: 1301 return (EPERM); 1302 } 1303 } 1304 #ifdef COMPAT_FREEBSD32 1305 /* 1306 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1307 * that it will get 32-bit packet headers. 1308 */ 1309 switch (cmd) { 1310 case BIOCSETF32: 1311 case BIOCSETFNR32: 1312 case BIOCSETWF32: 1313 case BIOCGDLTLIST32: 1314 case BIOCGRTIMEOUT32: 1315 case BIOCSRTIMEOUT32: 1316 BPFD_LOCK(d); 1317 d->bd_compat32 = 1; 1318 BPFD_UNLOCK(d); 1319 } 1320 #endif 1321 1322 CURVNET_SET(TD_TO_VNET(td)); 1323 switch (cmd) { 1324 1325 default: 1326 error = EINVAL; 1327 break; 1328 1329 /* 1330 * Check for read packet available. 1331 */ 1332 case FIONREAD: 1333 { 1334 int n; 1335 1336 BPFD_LOCK(d); 1337 n = d->bd_slen; 1338 while (d->bd_hbuf_in_use) 1339 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1340 PRINET, "bd_hbuf", 0); 1341 if (d->bd_hbuf) 1342 n += d->bd_hlen; 1343 BPFD_UNLOCK(d); 1344 1345 *(int *)addr = n; 1346 break; 1347 } 1348 1349 /* 1350 * Get buffer len [for read()]. 1351 */ 1352 case BIOCGBLEN: 1353 BPFD_LOCK(d); 1354 *(u_int *)addr = d->bd_bufsize; 1355 BPFD_UNLOCK(d); 1356 break; 1357 1358 /* 1359 * Set buffer length. 1360 */ 1361 case BIOCSBLEN: 1362 error = bpf_ioctl_sblen(d, (u_int *)addr); 1363 break; 1364 1365 /* 1366 * Set link layer read filter. 1367 */ 1368 case BIOCSETF: 1369 case BIOCSETFNR: 1370 case BIOCSETWF: 1371 #ifdef COMPAT_FREEBSD32 1372 case BIOCSETF32: 1373 case BIOCSETFNR32: 1374 case BIOCSETWF32: 1375 #endif 1376 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1377 break; 1378 1379 /* 1380 * Flush read packet buffer. 1381 */ 1382 case BIOCFLUSH: 1383 BPFD_LOCK(d); 1384 reset_d(d); 1385 BPFD_UNLOCK(d); 1386 break; 1387 1388 /* 1389 * Put interface into promiscuous mode. 1390 */ 1391 case BIOCPROMISC: 1392 if (d->bd_bif == NULL) { 1393 /* 1394 * No interface attached yet. 1395 */ 1396 error = EINVAL; 1397 break; 1398 } 1399 if (d->bd_promisc == 0) { 1400 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1401 if (error == 0) 1402 d->bd_promisc = 1; 1403 } 1404 break; 1405 1406 /* 1407 * Get current data link type. 1408 */ 1409 case BIOCGDLT: 1410 BPF_LOCK(); 1411 if (d->bd_bif == NULL) 1412 error = EINVAL; 1413 else 1414 *(u_int *)addr = d->bd_bif->bif_dlt; 1415 BPF_UNLOCK(); 1416 break; 1417 1418 /* 1419 * Get a list of supported data link types. 1420 */ 1421 #ifdef COMPAT_FREEBSD32 1422 case BIOCGDLTLIST32: 1423 { 1424 struct bpf_dltlist32 *list32; 1425 struct bpf_dltlist dltlist; 1426 1427 list32 = (struct bpf_dltlist32 *)addr; 1428 dltlist.bfl_len = list32->bfl_len; 1429 dltlist.bfl_list = PTRIN(list32->bfl_list); 1430 BPF_LOCK(); 1431 if (d->bd_bif == NULL) 1432 error = EINVAL; 1433 else { 1434 error = bpf_getdltlist(d, &dltlist); 1435 if (error == 0) 1436 list32->bfl_len = dltlist.bfl_len; 1437 } 1438 BPF_UNLOCK(); 1439 break; 1440 } 1441 #endif 1442 1443 case BIOCGDLTLIST: 1444 BPF_LOCK(); 1445 if (d->bd_bif == NULL) 1446 error = EINVAL; 1447 else 1448 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1449 BPF_UNLOCK(); 1450 break; 1451 1452 /* 1453 * Set data link type. 1454 */ 1455 case BIOCSDLT: 1456 BPF_LOCK(); 1457 if (d->bd_bif == NULL) 1458 error = EINVAL; 1459 else 1460 error = bpf_setdlt(d, *(u_int *)addr); 1461 BPF_UNLOCK(); 1462 break; 1463 1464 /* 1465 * Get interface name. 1466 */ 1467 case BIOCGETIF: 1468 BPF_LOCK(); 1469 if (d->bd_bif == NULL) 1470 error = EINVAL; 1471 else { 1472 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1473 struct ifreq *const ifr = (struct ifreq *)addr; 1474 1475 strlcpy(ifr->ifr_name, ifp->if_xname, 1476 sizeof(ifr->ifr_name)); 1477 } 1478 BPF_UNLOCK(); 1479 break; 1480 1481 /* 1482 * Set interface. 1483 */ 1484 case BIOCSETIF: 1485 { 1486 int alloc_buf, size; 1487 1488 /* 1489 * Behavior here depends on the buffering model. If 1490 * we're using kernel memory buffers, then we can 1491 * allocate them here. If we're using zero-copy, 1492 * then the user process must have registered buffers 1493 * by the time we get here. 1494 */ 1495 alloc_buf = 0; 1496 BPFD_LOCK(d); 1497 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1498 d->bd_sbuf == NULL) 1499 alloc_buf = 1; 1500 BPFD_UNLOCK(d); 1501 if (alloc_buf) { 1502 size = d->bd_bufsize; 1503 error = bpf_buffer_ioctl_sblen(d, &size); 1504 if (error != 0) 1505 break; 1506 } 1507 BPF_LOCK(); 1508 error = bpf_setif(d, (struct ifreq *)addr); 1509 BPF_UNLOCK(); 1510 break; 1511 } 1512 1513 /* 1514 * Set read timeout. 1515 */ 1516 case BIOCSRTIMEOUT: 1517 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1518 case BIOCSRTIMEOUT32: 1519 #endif 1520 { 1521 struct timeval *tv = (struct timeval *)addr; 1522 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1523 struct timeval32 *tv32; 1524 struct timeval tv64; 1525 1526 if (cmd == BIOCSRTIMEOUT32) { 1527 tv32 = (struct timeval32 *)addr; 1528 tv = &tv64; 1529 tv->tv_sec = tv32->tv_sec; 1530 tv->tv_usec = tv32->tv_usec; 1531 } else 1532 #endif 1533 tv = (struct timeval *)addr; 1534 1535 /* 1536 * Subtract 1 tick from tvtohz() since this isn't 1537 * a one-shot timer. 1538 */ 1539 if ((error = itimerfix(tv)) == 0) 1540 d->bd_rtout = tvtohz(tv) - 1; 1541 break; 1542 } 1543 1544 /* 1545 * Get read timeout. 1546 */ 1547 case BIOCGRTIMEOUT: 1548 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1549 case BIOCGRTIMEOUT32: 1550 #endif 1551 { 1552 struct timeval *tv; 1553 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1554 struct timeval32 *tv32; 1555 struct timeval tv64; 1556 1557 if (cmd == BIOCGRTIMEOUT32) 1558 tv = &tv64; 1559 else 1560 #endif 1561 tv = (struct timeval *)addr; 1562 1563 tv->tv_sec = d->bd_rtout / hz; 1564 tv->tv_usec = (d->bd_rtout % hz) * tick; 1565 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1566 if (cmd == BIOCGRTIMEOUT32) { 1567 tv32 = (struct timeval32 *)addr; 1568 tv32->tv_sec = tv->tv_sec; 1569 tv32->tv_usec = tv->tv_usec; 1570 } 1571 #endif 1572 1573 break; 1574 } 1575 1576 /* 1577 * Get packet stats. 1578 */ 1579 case BIOCGSTATS: 1580 { 1581 struct bpf_stat *bs = (struct bpf_stat *)addr; 1582 1583 /* XXXCSJP overflow */ 1584 bs->bs_recv = d->bd_rcount; 1585 bs->bs_drop = d->bd_dcount; 1586 break; 1587 } 1588 1589 /* 1590 * Set immediate mode. 1591 */ 1592 case BIOCIMMEDIATE: 1593 BPFD_LOCK(d); 1594 d->bd_immediate = *(u_int *)addr; 1595 BPFD_UNLOCK(d); 1596 break; 1597 1598 case BIOCVERSION: 1599 { 1600 struct bpf_version *bv = (struct bpf_version *)addr; 1601 1602 bv->bv_major = BPF_MAJOR_VERSION; 1603 bv->bv_minor = BPF_MINOR_VERSION; 1604 break; 1605 } 1606 1607 /* 1608 * Get "header already complete" flag 1609 */ 1610 case BIOCGHDRCMPLT: 1611 BPFD_LOCK(d); 1612 *(u_int *)addr = d->bd_hdrcmplt; 1613 BPFD_UNLOCK(d); 1614 break; 1615 1616 /* 1617 * Set "header already complete" flag 1618 */ 1619 case BIOCSHDRCMPLT: 1620 BPFD_LOCK(d); 1621 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1622 BPFD_UNLOCK(d); 1623 break; 1624 1625 /* 1626 * Get packet direction flag 1627 */ 1628 case BIOCGDIRECTION: 1629 BPFD_LOCK(d); 1630 *(u_int *)addr = d->bd_direction; 1631 BPFD_UNLOCK(d); 1632 break; 1633 1634 /* 1635 * Set packet direction flag 1636 */ 1637 case BIOCSDIRECTION: 1638 { 1639 u_int direction; 1640 1641 direction = *(u_int *)addr; 1642 switch (direction) { 1643 case BPF_D_IN: 1644 case BPF_D_INOUT: 1645 case BPF_D_OUT: 1646 BPFD_LOCK(d); 1647 d->bd_direction = direction; 1648 BPFD_UNLOCK(d); 1649 break; 1650 default: 1651 error = EINVAL; 1652 } 1653 } 1654 break; 1655 1656 /* 1657 * Get packet timestamp format and resolution. 1658 */ 1659 case BIOCGTSTAMP: 1660 BPFD_LOCK(d); 1661 *(u_int *)addr = d->bd_tstamp; 1662 BPFD_UNLOCK(d); 1663 break; 1664 1665 /* 1666 * Set packet timestamp format and resolution. 1667 */ 1668 case BIOCSTSTAMP: 1669 { 1670 u_int func; 1671 1672 func = *(u_int *)addr; 1673 if (BPF_T_VALID(func)) 1674 d->bd_tstamp = func; 1675 else 1676 error = EINVAL; 1677 } 1678 break; 1679 1680 case BIOCFEEDBACK: 1681 BPFD_LOCK(d); 1682 d->bd_feedback = *(u_int *)addr; 1683 BPFD_UNLOCK(d); 1684 break; 1685 1686 case BIOCLOCK: 1687 BPFD_LOCK(d); 1688 d->bd_locked = 1; 1689 BPFD_UNLOCK(d); 1690 break; 1691 1692 case FIONBIO: /* Non-blocking I/O */ 1693 break; 1694 1695 case FIOASYNC: /* Send signal on receive packets */ 1696 BPFD_LOCK(d); 1697 d->bd_async = *(int *)addr; 1698 BPFD_UNLOCK(d); 1699 break; 1700 1701 case FIOSETOWN: 1702 /* 1703 * XXX: Add some sort of locking here? 1704 * fsetown() can sleep. 1705 */ 1706 error = fsetown(*(int *)addr, &d->bd_sigio); 1707 break; 1708 1709 case FIOGETOWN: 1710 BPFD_LOCK(d); 1711 *(int *)addr = fgetown(&d->bd_sigio); 1712 BPFD_UNLOCK(d); 1713 break; 1714 1715 /* This is deprecated, FIOSETOWN should be used instead. */ 1716 case TIOCSPGRP: 1717 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1718 break; 1719 1720 /* This is deprecated, FIOGETOWN should be used instead. */ 1721 case TIOCGPGRP: 1722 *(int *)addr = -fgetown(&d->bd_sigio); 1723 break; 1724 1725 case BIOCSRSIG: /* Set receive signal */ 1726 { 1727 u_int sig; 1728 1729 sig = *(u_int *)addr; 1730 1731 if (sig >= NSIG) 1732 error = EINVAL; 1733 else { 1734 BPFD_LOCK(d); 1735 d->bd_sig = sig; 1736 BPFD_UNLOCK(d); 1737 } 1738 break; 1739 } 1740 case BIOCGRSIG: 1741 BPFD_LOCK(d); 1742 *(u_int *)addr = d->bd_sig; 1743 BPFD_UNLOCK(d); 1744 break; 1745 1746 case BIOCGETBUFMODE: 1747 BPFD_LOCK(d); 1748 *(u_int *)addr = d->bd_bufmode; 1749 BPFD_UNLOCK(d); 1750 break; 1751 1752 case BIOCSETBUFMODE: 1753 /* 1754 * Allow the buffering mode to be changed as long as we 1755 * haven't yet committed to a particular mode. Our 1756 * definition of commitment, for now, is whether or not a 1757 * buffer has been allocated or an interface attached, since 1758 * that's the point where things get tricky. 1759 */ 1760 switch (*(u_int *)addr) { 1761 case BPF_BUFMODE_BUFFER: 1762 break; 1763 1764 case BPF_BUFMODE_ZBUF: 1765 if (bpf_zerocopy_enable) 1766 break; 1767 /* FALLSTHROUGH */ 1768 1769 default: 1770 CURVNET_RESTORE(); 1771 return (EINVAL); 1772 } 1773 1774 BPFD_LOCK(d); 1775 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1776 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1777 BPFD_UNLOCK(d); 1778 CURVNET_RESTORE(); 1779 return (EBUSY); 1780 } 1781 d->bd_bufmode = *(u_int *)addr; 1782 BPFD_UNLOCK(d); 1783 break; 1784 1785 case BIOCGETZMAX: 1786 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1787 break; 1788 1789 case BIOCSETZBUF: 1790 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1791 break; 1792 1793 case BIOCROTZBUF: 1794 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1795 break; 1796 } 1797 CURVNET_RESTORE(); 1798 return (error); 1799 } 1800 1801 /* 1802 * Set d's packet filter program to fp. If this file already has a filter, 1803 * free it and replace it. Returns EINVAL for bogus requests. 1804 * 1805 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls 1806 * since reading d->bd_bif can't be protected by d or interface lock due to 1807 * lock order. 1808 * 1809 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses 1810 * interface read lock to read all filers. 1811 * 1812 */ 1813 static int 1814 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1815 { 1816 #ifdef COMPAT_FREEBSD32 1817 struct bpf_program fp_swab; 1818 struct bpf_program32 *fp32; 1819 #endif 1820 struct bpf_insn *fcode, *old; 1821 #ifdef BPF_JITTER 1822 bpf_jit_filter *jfunc, *ofunc; 1823 #endif 1824 size_t size; 1825 u_int flen; 1826 int need_upgrade; 1827 1828 #ifdef COMPAT_FREEBSD32 1829 switch (cmd) { 1830 case BIOCSETF32: 1831 case BIOCSETWF32: 1832 case BIOCSETFNR32: 1833 fp32 = (struct bpf_program32 *)fp; 1834 fp_swab.bf_len = fp32->bf_len; 1835 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1836 fp = &fp_swab; 1837 switch (cmd) { 1838 case BIOCSETF32: 1839 cmd = BIOCSETF; 1840 break; 1841 case BIOCSETWF32: 1842 cmd = BIOCSETWF; 1843 break; 1844 } 1845 break; 1846 } 1847 #endif 1848 1849 fcode = NULL; 1850 #ifdef BPF_JITTER 1851 jfunc = ofunc = NULL; 1852 #endif 1853 need_upgrade = 0; 1854 1855 /* 1856 * Check new filter validness before acquiring any locks. 1857 * Allocate memory for new filter, if needed. 1858 */ 1859 flen = fp->bf_len; 1860 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1861 return (EINVAL); 1862 size = flen * sizeof(*fp->bf_insns); 1863 if (size > 0) { 1864 /* We're setting up new filter. Copy and check actual data. */ 1865 fcode = malloc(size, M_BPF, M_WAITOK); 1866 if (copyin(fp->bf_insns, fcode, size) != 0 || 1867 !bpf_validate(fcode, flen)) { 1868 free(fcode, M_BPF); 1869 return (EINVAL); 1870 } 1871 #ifdef BPF_JITTER 1872 /* Filter is copied inside fcode and is perfectly valid. */ 1873 jfunc = bpf_jitter(fcode, flen); 1874 #endif 1875 } 1876 1877 BPF_LOCK(); 1878 1879 /* 1880 * Set up new filter. 1881 * Protect filter change by interface lock. 1882 * Additionally, we are protected by global lock here. 1883 */ 1884 if (d->bd_bif != NULL) 1885 BPFIF_WLOCK(d->bd_bif); 1886 BPFD_LOCK(d); 1887 if (cmd == BIOCSETWF) { 1888 old = d->bd_wfilter; 1889 d->bd_wfilter = fcode; 1890 } else { 1891 old = d->bd_rfilter; 1892 d->bd_rfilter = fcode; 1893 #ifdef BPF_JITTER 1894 ofunc = d->bd_bfilter; 1895 d->bd_bfilter = jfunc; 1896 #endif 1897 if (cmd == BIOCSETF) 1898 reset_d(d); 1899 1900 need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen); 1901 } 1902 BPFD_UNLOCK(d); 1903 if (d->bd_bif != NULL) 1904 BPFIF_WUNLOCK(d->bd_bif); 1905 if (old != NULL) 1906 free(old, M_BPF); 1907 #ifdef BPF_JITTER 1908 if (ofunc != NULL) 1909 bpf_destroy_jit_filter(ofunc); 1910 #endif 1911 1912 /* Move d to active readers list. */ 1913 if (need_upgrade != 0) 1914 bpf_upgraded(d); 1915 1916 BPF_UNLOCK(); 1917 return (0); 1918 } 1919 1920 /* 1921 * Detach a file from its current interface (if attached at all) and attach 1922 * to the interface indicated by the name stored in ifr. 1923 * Return an errno or 0. 1924 */ 1925 static int 1926 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1927 { 1928 struct bpf_if *bp; 1929 struct ifnet *theywant; 1930 1931 BPF_LOCK_ASSERT(); 1932 1933 theywant = ifunit(ifr->ifr_name); 1934 if (theywant == NULL || theywant->if_bpf == NULL) 1935 return (ENXIO); 1936 1937 bp = theywant->if_bpf; 1938 1939 /* Check if interface is not being detached from BPF */ 1940 BPFIF_RLOCK(bp); 1941 if (bp->bif_flags & BPFIF_FLAG_DYING) { 1942 BPFIF_RUNLOCK(bp); 1943 return (ENXIO); 1944 } 1945 BPFIF_RUNLOCK(bp); 1946 1947 /* 1948 * At this point, we expect the buffer is already allocated. If not, 1949 * return an error. 1950 */ 1951 switch (d->bd_bufmode) { 1952 case BPF_BUFMODE_BUFFER: 1953 case BPF_BUFMODE_ZBUF: 1954 if (d->bd_sbuf == NULL) 1955 return (EINVAL); 1956 break; 1957 1958 default: 1959 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1960 } 1961 if (bp != d->bd_bif) 1962 bpf_attachd(d, bp); 1963 BPFD_LOCK(d); 1964 reset_d(d); 1965 BPFD_UNLOCK(d); 1966 return (0); 1967 } 1968 1969 /* 1970 * Support for select() and poll() system calls 1971 * 1972 * Return true iff the specific operation will not block indefinitely. 1973 * Otherwise, return false but make a note that a selwakeup() must be done. 1974 */ 1975 static int 1976 bpfpoll(struct cdev *dev, int events, struct thread *td) 1977 { 1978 struct bpf_d *d; 1979 int revents; 1980 1981 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 1982 return (events & 1983 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 1984 1985 /* 1986 * Refresh PID associated with this descriptor. 1987 */ 1988 revents = events & (POLLOUT | POLLWRNORM); 1989 BPFD_LOCK(d); 1990 BPF_PID_REFRESH(d, td); 1991 if (events & (POLLIN | POLLRDNORM)) { 1992 if (bpf_ready(d)) 1993 revents |= events & (POLLIN | POLLRDNORM); 1994 else { 1995 selrecord(td, &d->bd_sel); 1996 /* Start the read timeout if necessary. */ 1997 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1998 callout_reset(&d->bd_callout, d->bd_rtout, 1999 bpf_timed_out, d); 2000 d->bd_state = BPF_WAITING; 2001 } 2002 } 2003 } 2004 BPFD_UNLOCK(d); 2005 return (revents); 2006 } 2007 2008 /* 2009 * Support for kevent() system call. Register EVFILT_READ filters and 2010 * reject all others. 2011 */ 2012 int 2013 bpfkqfilter(struct cdev *dev, struct knote *kn) 2014 { 2015 struct bpf_d *d; 2016 2017 if (devfs_get_cdevpriv((void **)&d) != 0 || 2018 kn->kn_filter != EVFILT_READ) 2019 return (1); 2020 2021 /* 2022 * Refresh PID associated with this descriptor. 2023 */ 2024 BPFD_LOCK(d); 2025 BPF_PID_REFRESH_CUR(d); 2026 kn->kn_fop = &bpfread_filtops; 2027 kn->kn_hook = d; 2028 knlist_add(&d->bd_sel.si_note, kn, 1); 2029 BPFD_UNLOCK(d); 2030 2031 return (0); 2032 } 2033 2034 static void 2035 filt_bpfdetach(struct knote *kn) 2036 { 2037 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2038 2039 knlist_remove(&d->bd_sel.si_note, kn, 0); 2040 } 2041 2042 static int 2043 filt_bpfread(struct knote *kn, long hint) 2044 { 2045 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2046 int ready; 2047 2048 BPFD_LOCK_ASSERT(d); 2049 ready = bpf_ready(d); 2050 if (ready) { 2051 kn->kn_data = d->bd_slen; 2052 /* 2053 * Ignore the hold buffer if it is being copied to user space. 2054 */ 2055 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2056 kn->kn_data += d->bd_hlen; 2057 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2058 callout_reset(&d->bd_callout, d->bd_rtout, 2059 bpf_timed_out, d); 2060 d->bd_state = BPF_WAITING; 2061 } 2062 2063 return (ready); 2064 } 2065 2066 #define BPF_TSTAMP_NONE 0 2067 #define BPF_TSTAMP_FAST 1 2068 #define BPF_TSTAMP_NORMAL 2 2069 #define BPF_TSTAMP_EXTERN 3 2070 2071 static int 2072 bpf_ts_quality(int tstype) 2073 { 2074 2075 if (tstype == BPF_T_NONE) 2076 return (BPF_TSTAMP_NONE); 2077 if ((tstype & BPF_T_FAST) != 0) 2078 return (BPF_TSTAMP_FAST); 2079 2080 return (BPF_TSTAMP_NORMAL); 2081 } 2082 2083 static int 2084 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2085 { 2086 struct m_tag *tag; 2087 int quality; 2088 2089 quality = bpf_ts_quality(tstype); 2090 if (quality == BPF_TSTAMP_NONE) 2091 return (quality); 2092 2093 if (m != NULL) { 2094 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2095 if (tag != NULL) { 2096 *bt = *(struct bintime *)(tag + 1); 2097 return (BPF_TSTAMP_EXTERN); 2098 } 2099 } 2100 if (quality == BPF_TSTAMP_NORMAL) 2101 binuptime(bt); 2102 else 2103 getbinuptime(bt); 2104 2105 return (quality); 2106 } 2107 2108 /* 2109 * Incoming linkage from device drivers. Process the packet pkt, of length 2110 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2111 * by each process' filter, and if accepted, stashed into the corresponding 2112 * buffer. 2113 */ 2114 void 2115 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2116 { 2117 struct bintime bt; 2118 struct bpf_d *d; 2119 #ifdef BPF_JITTER 2120 bpf_jit_filter *bf; 2121 #endif 2122 u_int slen; 2123 int gottime; 2124 2125 gottime = BPF_TSTAMP_NONE; 2126 2127 BPFIF_RLOCK(bp); 2128 2129 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2130 /* 2131 * We are not using any locks for d here because: 2132 * 1) any filter change is protected by interface 2133 * write lock 2134 * 2) destroying/detaching d is protected by interface 2135 * write lock, too 2136 */ 2137 2138 /* XXX: Do not protect counter for the sake of performance. */ 2139 ++d->bd_rcount; 2140 /* 2141 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no 2142 * way for the caller to indiciate to us whether this packet 2143 * is inbound or outbound. In the bpf_mtap() routines, we use 2144 * the interface pointers on the mbuf to figure it out. 2145 */ 2146 #ifdef BPF_JITTER 2147 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2148 if (bf != NULL) 2149 slen = (*(bf->func))(pkt, pktlen, pktlen); 2150 else 2151 #endif 2152 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2153 if (slen != 0) { 2154 /* 2155 * Filter matches. Let's to acquire write lock. 2156 */ 2157 BPFD_LOCK(d); 2158 2159 d->bd_fcount++; 2160 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2161 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL); 2162 #ifdef MAC 2163 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2164 #endif 2165 catchpacket(d, pkt, pktlen, slen, 2166 bpf_append_bytes, &bt); 2167 BPFD_UNLOCK(d); 2168 } 2169 } 2170 BPFIF_RUNLOCK(bp); 2171 } 2172 2173 #define BPF_CHECK_DIRECTION(d, r, i) \ 2174 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2175 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2176 2177 /* 2178 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2179 * Locking model is explained in bpf_tap(). 2180 */ 2181 void 2182 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2183 { 2184 struct bintime bt; 2185 struct bpf_d *d; 2186 #ifdef BPF_JITTER 2187 bpf_jit_filter *bf; 2188 #endif 2189 u_int pktlen, slen; 2190 int gottime; 2191 2192 /* Skip outgoing duplicate packets. */ 2193 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2194 m->m_flags &= ~M_PROMISC; 2195 return; 2196 } 2197 2198 pktlen = m_length(m, NULL); 2199 gottime = BPF_TSTAMP_NONE; 2200 2201 BPFIF_RLOCK(bp); 2202 2203 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2204 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2205 continue; 2206 ++d->bd_rcount; 2207 #ifdef BPF_JITTER 2208 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2209 /* XXX We cannot handle multiple mbufs. */ 2210 if (bf != NULL && m->m_next == NULL) 2211 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); 2212 else 2213 #endif 2214 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2215 if (slen != 0) { 2216 BPFD_LOCK(d); 2217 2218 d->bd_fcount++; 2219 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2220 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2221 #ifdef MAC 2222 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2223 #endif 2224 catchpacket(d, (u_char *)m, pktlen, slen, 2225 bpf_append_mbuf, &bt); 2226 BPFD_UNLOCK(d); 2227 } 2228 } 2229 BPFIF_RUNLOCK(bp); 2230 } 2231 2232 /* 2233 * Incoming linkage from device drivers, when packet is in 2234 * an mbuf chain and to be prepended by a contiguous header. 2235 */ 2236 void 2237 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2238 { 2239 struct bintime bt; 2240 struct mbuf mb; 2241 struct bpf_d *d; 2242 u_int pktlen, slen; 2243 int gottime; 2244 2245 /* Skip outgoing duplicate packets. */ 2246 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2247 m->m_flags &= ~M_PROMISC; 2248 return; 2249 } 2250 2251 pktlen = m_length(m, NULL); 2252 /* 2253 * Craft on-stack mbuf suitable for passing to bpf_filter. 2254 * Note that we cut corners here; we only setup what's 2255 * absolutely needed--this mbuf should never go anywhere else. 2256 */ 2257 mb.m_next = m; 2258 mb.m_data = data; 2259 mb.m_len = dlen; 2260 pktlen += dlen; 2261 2262 gottime = BPF_TSTAMP_NONE; 2263 2264 BPFIF_RLOCK(bp); 2265 2266 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2267 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2268 continue; 2269 ++d->bd_rcount; 2270 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2271 if (slen != 0) { 2272 BPFD_LOCK(d); 2273 2274 d->bd_fcount++; 2275 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2276 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2277 #ifdef MAC 2278 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2279 #endif 2280 catchpacket(d, (u_char *)&mb, pktlen, slen, 2281 bpf_append_mbuf, &bt); 2282 BPFD_UNLOCK(d); 2283 } 2284 } 2285 BPFIF_RUNLOCK(bp); 2286 } 2287 2288 #undef BPF_CHECK_DIRECTION 2289 2290 #undef BPF_TSTAMP_NONE 2291 #undef BPF_TSTAMP_FAST 2292 #undef BPF_TSTAMP_NORMAL 2293 #undef BPF_TSTAMP_EXTERN 2294 2295 static int 2296 bpf_hdrlen(struct bpf_d *d) 2297 { 2298 int hdrlen; 2299 2300 hdrlen = d->bd_bif->bif_hdrlen; 2301 #ifndef BURN_BRIDGES 2302 if (d->bd_tstamp == BPF_T_NONE || 2303 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2304 #ifdef COMPAT_FREEBSD32 2305 if (d->bd_compat32) 2306 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2307 else 2308 #endif 2309 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2310 else 2311 #endif 2312 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2313 #ifdef COMPAT_FREEBSD32 2314 if (d->bd_compat32) 2315 hdrlen = BPF_WORDALIGN32(hdrlen); 2316 else 2317 #endif 2318 hdrlen = BPF_WORDALIGN(hdrlen); 2319 2320 return (hdrlen - d->bd_bif->bif_hdrlen); 2321 } 2322 2323 static void 2324 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2325 { 2326 struct bintime bt2; 2327 struct timeval tsm; 2328 struct timespec tsn; 2329 2330 if ((tstype & BPF_T_MONOTONIC) == 0) { 2331 bt2 = *bt; 2332 bintime_add(&bt2, &boottimebin); 2333 bt = &bt2; 2334 } 2335 switch (BPF_T_FORMAT(tstype)) { 2336 case BPF_T_MICROTIME: 2337 bintime2timeval(bt, &tsm); 2338 ts->bt_sec = tsm.tv_sec; 2339 ts->bt_frac = tsm.tv_usec; 2340 break; 2341 case BPF_T_NANOTIME: 2342 bintime2timespec(bt, &tsn); 2343 ts->bt_sec = tsn.tv_sec; 2344 ts->bt_frac = tsn.tv_nsec; 2345 break; 2346 case BPF_T_BINTIME: 2347 ts->bt_sec = bt->sec; 2348 ts->bt_frac = bt->frac; 2349 break; 2350 } 2351 } 2352 2353 /* 2354 * Move the packet data from interface memory (pkt) into the 2355 * store buffer. "cpfn" is the routine called to do the actual data 2356 * transfer. bcopy is passed in to copy contiguous chunks, while 2357 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2358 * pkt is really an mbuf. 2359 */ 2360 static void 2361 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2362 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2363 struct bintime *bt) 2364 { 2365 struct bpf_xhdr hdr; 2366 #ifndef BURN_BRIDGES 2367 struct bpf_hdr hdr_old; 2368 #ifdef COMPAT_FREEBSD32 2369 struct bpf_hdr32 hdr32_old; 2370 #endif 2371 #endif 2372 int caplen, curlen, hdrlen, totlen; 2373 int do_wakeup = 0; 2374 int do_timestamp; 2375 int tstype; 2376 2377 BPFD_LOCK_ASSERT(d); 2378 2379 /* 2380 * Detect whether user space has released a buffer back to us, and if 2381 * so, move it from being a hold buffer to a free buffer. This may 2382 * not be the best place to do it (for example, we might only want to 2383 * run this check if we need the space), but for now it's a reliable 2384 * spot to do it. 2385 */ 2386 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2387 d->bd_fbuf = d->bd_hbuf; 2388 d->bd_hbuf = NULL; 2389 d->bd_hlen = 0; 2390 bpf_buf_reclaimed(d); 2391 } 2392 2393 /* 2394 * Figure out how many bytes to move. If the packet is 2395 * greater or equal to the snapshot length, transfer that 2396 * much. Otherwise, transfer the whole packet (unless 2397 * we hit the buffer size limit). 2398 */ 2399 hdrlen = bpf_hdrlen(d); 2400 totlen = hdrlen + min(snaplen, pktlen); 2401 if (totlen > d->bd_bufsize) 2402 totlen = d->bd_bufsize; 2403 2404 /* 2405 * Round up the end of the previous packet to the next longword. 2406 * 2407 * Drop the packet if there's no room and no hope of room 2408 * If the packet would overflow the storage buffer or the storage 2409 * buffer is considered immutable by the buffer model, try to rotate 2410 * the buffer and wakeup pending processes. 2411 */ 2412 #ifdef COMPAT_FREEBSD32 2413 if (d->bd_compat32) 2414 curlen = BPF_WORDALIGN32(d->bd_slen); 2415 else 2416 #endif 2417 curlen = BPF_WORDALIGN(d->bd_slen); 2418 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2419 if (d->bd_fbuf == NULL) { 2420 /* 2421 * There's no room in the store buffer, and no 2422 * prospect of room, so drop the packet. Notify the 2423 * buffer model. 2424 */ 2425 bpf_buffull(d); 2426 ++d->bd_dcount; 2427 return; 2428 } 2429 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2430 ROTATE_BUFFERS(d); 2431 do_wakeup = 1; 2432 curlen = 0; 2433 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2434 /* 2435 * Immediate mode is set, or the read timeout has already 2436 * expired during a select call. A packet arrived, so the 2437 * reader should be woken up. 2438 */ 2439 do_wakeup = 1; 2440 caplen = totlen - hdrlen; 2441 tstype = d->bd_tstamp; 2442 do_timestamp = tstype != BPF_T_NONE; 2443 #ifndef BURN_BRIDGES 2444 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2445 struct bpf_ts ts; 2446 if (do_timestamp) 2447 bpf_bintime2ts(bt, &ts, tstype); 2448 #ifdef COMPAT_FREEBSD32 2449 if (d->bd_compat32) { 2450 bzero(&hdr32_old, sizeof(hdr32_old)); 2451 if (do_timestamp) { 2452 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2453 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2454 } 2455 hdr32_old.bh_datalen = pktlen; 2456 hdr32_old.bh_hdrlen = hdrlen; 2457 hdr32_old.bh_caplen = caplen; 2458 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2459 sizeof(hdr32_old)); 2460 goto copy; 2461 } 2462 #endif 2463 bzero(&hdr_old, sizeof(hdr_old)); 2464 if (do_timestamp) { 2465 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2466 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2467 } 2468 hdr_old.bh_datalen = pktlen; 2469 hdr_old.bh_hdrlen = hdrlen; 2470 hdr_old.bh_caplen = caplen; 2471 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2472 sizeof(hdr_old)); 2473 goto copy; 2474 } 2475 #endif 2476 2477 /* 2478 * Append the bpf header. Note we append the actual header size, but 2479 * move forward the length of the header plus padding. 2480 */ 2481 bzero(&hdr, sizeof(hdr)); 2482 if (do_timestamp) 2483 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2484 hdr.bh_datalen = pktlen; 2485 hdr.bh_hdrlen = hdrlen; 2486 hdr.bh_caplen = caplen; 2487 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2488 2489 /* 2490 * Copy the packet data into the store buffer and update its length. 2491 */ 2492 #ifndef BURN_BRIDGES 2493 copy: 2494 #endif 2495 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2496 d->bd_slen = curlen + totlen; 2497 2498 if (do_wakeup) 2499 bpf_wakeup(d); 2500 } 2501 2502 /* 2503 * Free buffers currently in use by a descriptor. 2504 * Called on close. 2505 */ 2506 static void 2507 bpf_freed(struct bpf_d *d) 2508 { 2509 2510 /* 2511 * We don't need to lock out interrupts since this descriptor has 2512 * been detached from its interface and it yet hasn't been marked 2513 * free. 2514 */ 2515 bpf_free(d); 2516 if (d->bd_rfilter != NULL) { 2517 free((caddr_t)d->bd_rfilter, M_BPF); 2518 #ifdef BPF_JITTER 2519 if (d->bd_bfilter != NULL) 2520 bpf_destroy_jit_filter(d->bd_bfilter); 2521 #endif 2522 } 2523 if (d->bd_wfilter != NULL) 2524 free((caddr_t)d->bd_wfilter, M_BPF); 2525 mtx_destroy(&d->bd_lock); 2526 } 2527 2528 /* 2529 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2530 * fixed size of the link header (variable length headers not yet supported). 2531 */ 2532 void 2533 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2534 { 2535 2536 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2537 } 2538 2539 /* 2540 * Attach an interface to bpf. ifp is a pointer to the structure 2541 * defining the interface to be attached, dlt is the link layer type, 2542 * and hdrlen is the fixed size of the link header (variable length 2543 * headers are not yet supporrted). 2544 */ 2545 void 2546 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2547 { 2548 struct bpf_if *bp; 2549 2550 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 2551 if (bp == NULL) 2552 panic("bpfattach"); 2553 2554 LIST_INIT(&bp->bif_dlist); 2555 LIST_INIT(&bp->bif_wlist); 2556 bp->bif_ifp = ifp; 2557 bp->bif_dlt = dlt; 2558 rw_init(&bp->bif_lock, "bpf interface lock"); 2559 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 2560 *driverp = bp; 2561 2562 BPF_LOCK(); 2563 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2564 BPF_UNLOCK(); 2565 2566 bp->bif_hdrlen = hdrlen; 2567 2568 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2569 if_printf(ifp, "bpf attached\n"); 2570 } 2571 2572 /* 2573 * Detach bpf from an interface. This involves detaching each descriptor 2574 * associated with the interface. Notify each descriptor as it's detached 2575 * so that any sleepers wake up and get ENXIO. 2576 */ 2577 void 2578 bpfdetach(struct ifnet *ifp) 2579 { 2580 struct bpf_if *bp, *bp_temp; 2581 struct bpf_d *d; 2582 int ndetached; 2583 2584 ndetached = 0; 2585 2586 BPF_LOCK(); 2587 /* Find all bpf_if struct's which reference ifp and detach them. */ 2588 LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2589 if (ifp != bp->bif_ifp) 2590 continue; 2591 2592 LIST_REMOVE(bp, bif_next); 2593 /* Add to to-be-freed list */ 2594 LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next); 2595 2596 ndetached++; 2597 /* 2598 * Delay freeing bp till interface is detached 2599 * and all routes through this interface are removed. 2600 * Mark bp as detached to restrict new consumers. 2601 */ 2602 BPFIF_WLOCK(bp); 2603 bp->bif_flags |= BPFIF_FLAG_DYING; 2604 BPFIF_WUNLOCK(bp); 2605 2606 CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p", 2607 __func__, bp->bif_dlt, bp, ifp); 2608 2609 /* Free common descriptors */ 2610 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 2611 bpf_detachd_locked(d); 2612 BPFD_LOCK(d); 2613 bpf_wakeup(d); 2614 BPFD_UNLOCK(d); 2615 } 2616 2617 /* Free writer-only descriptors */ 2618 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) { 2619 bpf_detachd_locked(d); 2620 BPFD_LOCK(d); 2621 bpf_wakeup(d); 2622 BPFD_UNLOCK(d); 2623 } 2624 } 2625 BPF_UNLOCK(); 2626 2627 #ifdef INVARIANTS 2628 if (ndetached == 0) 2629 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 2630 #endif 2631 } 2632 2633 /* 2634 * Interface departure handler. 2635 * Note departure event does not guarantee interface is going down. 2636 * Interface renaming is currently done via departure/arrival event set. 2637 * 2638 * Departure handled is called after all routes pointing to 2639 * given interface are removed and interface is in down state 2640 * restricting any packets to be sent/received. We assume it is now safe 2641 * to free data allocated by BPF. 2642 */ 2643 static void 2644 bpf_ifdetach(void *arg __unused, struct ifnet *ifp) 2645 { 2646 struct bpf_if *bp, *bp_temp; 2647 int nmatched = 0; 2648 2649 BPF_LOCK(); 2650 /* 2651 * Find matching entries in free list. 2652 * Nothing should be found if bpfdetach() was not called. 2653 */ 2654 LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) { 2655 if (ifp != bp->bif_ifp) 2656 continue; 2657 2658 CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p", 2659 __func__, bp, ifp); 2660 2661 LIST_REMOVE(bp, bif_next); 2662 2663 rw_destroy(&bp->bif_lock); 2664 free(bp, M_BPF); 2665 2666 nmatched++; 2667 } 2668 BPF_UNLOCK(); 2669 2670 /* 2671 * Note that we cannot zero other pointers to 2672 * custom DLTs possibly used by given interface. 2673 */ 2674 if (nmatched != 0) 2675 ifp->if_bpf = NULL; 2676 } 2677 2678 /* 2679 * Get a list of available data link type of the interface. 2680 */ 2681 static int 2682 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2683 { 2684 struct ifnet *ifp; 2685 struct bpf_if *bp; 2686 u_int *lst; 2687 int error, n, n1; 2688 2689 BPF_LOCK_ASSERT(); 2690 2691 ifp = d->bd_bif->bif_ifp; 2692 again: 2693 n1 = 0; 2694 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2695 if (bp->bif_ifp == ifp) 2696 n1++; 2697 } 2698 if (bfl->bfl_list == NULL) { 2699 bfl->bfl_len = n1; 2700 return (0); 2701 } 2702 if (n1 > bfl->bfl_len) 2703 return (ENOMEM); 2704 BPF_UNLOCK(); 2705 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2706 n = 0; 2707 BPF_LOCK(); 2708 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2709 if (bp->bif_ifp != ifp) 2710 continue; 2711 if (n > n1) { 2712 free(lst, M_TEMP); 2713 goto again; 2714 } 2715 lst[n] = bp->bif_dlt; 2716 n++; 2717 } 2718 BPF_UNLOCK(); 2719 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2720 free(lst, M_TEMP); 2721 BPF_LOCK(); 2722 bfl->bfl_len = n; 2723 return (error); 2724 } 2725 2726 /* 2727 * Set the data link type of a BPF instance. 2728 */ 2729 static int 2730 bpf_setdlt(struct bpf_d *d, u_int dlt) 2731 { 2732 int error, opromisc; 2733 struct ifnet *ifp; 2734 struct bpf_if *bp; 2735 2736 BPF_LOCK_ASSERT(); 2737 2738 if (d->bd_bif->bif_dlt == dlt) 2739 return (0); 2740 ifp = d->bd_bif->bif_ifp; 2741 2742 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2743 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2744 break; 2745 } 2746 2747 if (bp != NULL) { 2748 opromisc = d->bd_promisc; 2749 bpf_attachd(d, bp); 2750 BPFD_LOCK(d); 2751 reset_d(d); 2752 BPFD_UNLOCK(d); 2753 if (opromisc) { 2754 error = ifpromisc(bp->bif_ifp, 1); 2755 if (error) 2756 if_printf(bp->bif_ifp, 2757 "bpf_setdlt: ifpromisc failed (%d)\n", 2758 error); 2759 else 2760 d->bd_promisc = 1; 2761 } 2762 } 2763 return (bp == NULL ? EINVAL : 0); 2764 } 2765 2766 static void 2767 bpf_drvinit(void *unused) 2768 { 2769 struct cdev *dev; 2770 2771 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2772 LIST_INIT(&bpf_iflist); 2773 LIST_INIT(&bpf_freelist); 2774 2775 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2776 /* For compatibility */ 2777 make_dev_alias(dev, "bpf0"); 2778 2779 /* Register interface departure handler */ 2780 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER( 2781 ifnet_departure_event, bpf_ifdetach, NULL, 2782 EVENTHANDLER_PRI_ANY); 2783 } 2784 2785 /* 2786 * Zero out the various packet counters associated with all of the bpf 2787 * descriptors. At some point, we will probably want to get a bit more 2788 * granular and allow the user to specify descriptors to be zeroed. 2789 */ 2790 static void 2791 bpf_zero_counters(void) 2792 { 2793 struct bpf_if *bp; 2794 struct bpf_d *bd; 2795 2796 BPF_LOCK(); 2797 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2798 BPFIF_RLOCK(bp); 2799 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2800 BPFD_LOCK(bd); 2801 bd->bd_rcount = 0; 2802 bd->bd_dcount = 0; 2803 bd->bd_fcount = 0; 2804 bd->bd_wcount = 0; 2805 bd->bd_wfcount = 0; 2806 bd->bd_zcopy = 0; 2807 BPFD_UNLOCK(bd); 2808 } 2809 BPFIF_RUNLOCK(bp); 2810 } 2811 BPF_UNLOCK(); 2812 } 2813 2814 /* 2815 * Fill filter statistics 2816 */ 2817 static void 2818 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2819 { 2820 2821 bzero(d, sizeof(*d)); 2822 BPFD_LOCK_ASSERT(bd); 2823 d->bd_structsize = sizeof(*d); 2824 /* XXX: reading should be protected by global lock */ 2825 d->bd_immediate = bd->bd_immediate; 2826 d->bd_promisc = bd->bd_promisc; 2827 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2828 d->bd_direction = bd->bd_direction; 2829 d->bd_feedback = bd->bd_feedback; 2830 d->bd_async = bd->bd_async; 2831 d->bd_rcount = bd->bd_rcount; 2832 d->bd_dcount = bd->bd_dcount; 2833 d->bd_fcount = bd->bd_fcount; 2834 d->bd_sig = bd->bd_sig; 2835 d->bd_slen = bd->bd_slen; 2836 d->bd_hlen = bd->bd_hlen; 2837 d->bd_bufsize = bd->bd_bufsize; 2838 d->bd_pid = bd->bd_pid; 2839 strlcpy(d->bd_ifname, 2840 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2841 d->bd_locked = bd->bd_locked; 2842 d->bd_wcount = bd->bd_wcount; 2843 d->bd_wdcount = bd->bd_wdcount; 2844 d->bd_wfcount = bd->bd_wfcount; 2845 d->bd_zcopy = bd->bd_zcopy; 2846 d->bd_bufmode = bd->bd_bufmode; 2847 } 2848 2849 /* 2850 * Handle `netstat -B' stats request 2851 */ 2852 static int 2853 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2854 { 2855 static const struct xbpf_d zerostats; 2856 struct xbpf_d *xbdbuf, *xbd, tempstats; 2857 int index, error; 2858 struct bpf_if *bp; 2859 struct bpf_d *bd; 2860 2861 /* 2862 * XXX This is not technically correct. It is possible for non 2863 * privileged users to open bpf devices. It would make sense 2864 * if the users who opened the devices were able to retrieve 2865 * the statistics for them, too. 2866 */ 2867 error = priv_check(req->td, PRIV_NET_BPF); 2868 if (error) 2869 return (error); 2870 /* 2871 * Check to see if the user is requesting that the counters be 2872 * zeroed out. Explicitly check that the supplied data is zeroed, 2873 * as we aren't allowing the user to set the counters currently. 2874 */ 2875 if (req->newptr != NULL) { 2876 if (req->newlen != sizeof(tempstats)) 2877 return (EINVAL); 2878 memset(&tempstats, 0, sizeof(tempstats)); 2879 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2880 if (error) 2881 return (error); 2882 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2883 return (EINVAL); 2884 bpf_zero_counters(); 2885 return (0); 2886 } 2887 if (req->oldptr == NULL) 2888 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2889 if (bpf_bpfd_cnt == 0) 2890 return (SYSCTL_OUT(req, 0, 0)); 2891 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2892 BPF_LOCK(); 2893 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2894 BPF_UNLOCK(); 2895 free(xbdbuf, M_BPF); 2896 return (ENOMEM); 2897 } 2898 index = 0; 2899 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2900 BPFIF_RLOCK(bp); 2901 /* Send writers-only first */ 2902 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2903 xbd = &xbdbuf[index++]; 2904 BPFD_LOCK(bd); 2905 bpfstats_fill_xbpf(xbd, bd); 2906 BPFD_UNLOCK(bd); 2907 } 2908 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2909 xbd = &xbdbuf[index++]; 2910 BPFD_LOCK(bd); 2911 bpfstats_fill_xbpf(xbd, bd); 2912 BPFD_UNLOCK(bd); 2913 } 2914 BPFIF_RUNLOCK(bp); 2915 } 2916 BPF_UNLOCK(); 2917 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2918 free(xbdbuf, M_BPF); 2919 return (error); 2920 } 2921 2922 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2923 2924 #else /* !DEV_BPF && !NETGRAPH_BPF */ 2925 /* 2926 * NOP stubs to allow bpf-using drivers to load and function. 2927 * 2928 * A 'better' implementation would allow the core bpf functionality 2929 * to be loaded at runtime. 2930 */ 2931 static struct bpf_if bp_null; 2932 2933 void 2934 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2935 { 2936 } 2937 2938 void 2939 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2940 { 2941 } 2942 2943 void 2944 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2945 { 2946 } 2947 2948 void 2949 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2950 { 2951 2952 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2953 } 2954 2955 void 2956 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2957 { 2958 2959 *driverp = &bp_null; 2960 } 2961 2962 void 2963 bpfdetach(struct ifnet *ifp) 2964 { 2965 } 2966 2967 u_int 2968 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 2969 { 2970 return -1; /* "no filter" behaviour */ 2971 } 2972 2973 int 2974 bpf_validate(const struct bpf_insn *f, int len) 2975 { 2976 return 0; /* false */ 2977 } 2978 2979 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 2980