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 * 3. 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_ddb.h" 43 #include "opt_netgraph.h" 44 45 #include <sys/types.h> 46 #include <sys/param.h> 47 #include <sys/lock.h> 48 #include <sys/rwlock.h> 49 #include <sys/systm.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/jail.h> 53 #include <sys/malloc.h> 54 #include <sys/mbuf.h> 55 #include <sys/time.h> 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/signalvar.h> 59 #include <sys/filio.h> 60 #include <sys/sockio.h> 61 #include <sys/ttycom.h> 62 #include <sys/uio.h> 63 64 #include <sys/event.h> 65 #include <sys/file.h> 66 #include <sys/poll.h> 67 #include <sys/proc.h> 68 69 #include <sys/socket.h> 70 71 #ifdef DDB 72 #include <ddb/ddb.h> 73 #endif 74 75 #include <net/if.h> 76 #include <net/if_var.h> 77 #include <net/if_dl.h> 78 #include <net/bpf.h> 79 #include <net/bpf_buffer.h> 80 #ifdef BPF_JITTER 81 #include <net/bpf_jitter.h> 82 #endif 83 #include <net/bpf_zerocopy.h> 84 #include <net/bpfdesc.h> 85 #include <net/route.h> 86 #include <net/vnet.h> 87 88 #include <netinet/in.h> 89 #include <netinet/if_ether.h> 90 #include <sys/kernel.h> 91 #include <sys/sysctl.h> 92 93 #include <net80211/ieee80211_freebsd.h> 94 95 #include <security/mac/mac_framework.h> 96 97 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 98 99 struct bpf_if { 100 #define bif_next bif_ext.bif_next 101 #define bif_dlist bif_ext.bif_dlist 102 struct bpf_if_ext bif_ext; /* public members */ 103 u_int bif_dlt; /* link layer type */ 104 u_int bif_hdrlen; /* length of link header */ 105 struct ifnet *bif_ifp; /* corresponding interface */ 106 struct rwlock bif_lock; /* interface lock */ 107 LIST_HEAD(, bpf_d) bif_wlist; /* writer-only list */ 108 int bif_flags; /* Interface flags */ 109 }; 110 111 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); 112 113 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 114 115 #define PRINET 26 /* interruptible */ 116 117 #define SIZEOF_BPF_HDR(type) \ 118 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 119 120 #ifdef COMPAT_FREEBSD32 121 #include <sys/mount.h> 122 #include <compat/freebsd32/freebsd32.h> 123 #define BPF_ALIGNMENT32 sizeof(int32_t) 124 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) 125 126 #ifndef BURN_BRIDGES 127 /* 128 * 32-bit version of structure prepended to each packet. We use this header 129 * instead of the standard one for 32-bit streams. We mark the a stream as 130 * 32-bit the first time we see a 32-bit compat ioctl request. 131 */ 132 struct bpf_hdr32 { 133 struct timeval32 bh_tstamp; /* time stamp */ 134 uint32_t bh_caplen; /* length of captured portion */ 135 uint32_t bh_datalen; /* original length of packet */ 136 uint16_t bh_hdrlen; /* length of bpf header (this struct 137 plus alignment padding) */ 138 }; 139 #endif 140 141 struct bpf_program32 { 142 u_int bf_len; 143 uint32_t bf_insns; 144 }; 145 146 struct bpf_dltlist32 { 147 u_int bfl_len; 148 u_int bfl_list; 149 }; 150 151 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 152 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 153 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 154 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 155 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 156 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 157 #endif 158 159 /* 160 * bpf_iflist is a list of BPF interface structures, each corresponding to a 161 * specific DLT. The same network interface might have several BPF interface 162 * structures registered by different layers in the stack (i.e., 802.11 163 * frames, ethernet frames, etc). 164 */ 165 static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist; 166 static struct mtx bpf_mtx; /* bpf global lock */ 167 static int bpf_bpfd_cnt; 168 169 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 170 static void bpf_detachd(struct bpf_d *); 171 static void bpf_detachd_locked(struct bpf_d *); 172 static void bpf_freed(struct bpf_d *); 173 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 174 struct sockaddr *, int *, struct bpf_d *); 175 static int bpf_setif(struct bpf_d *, struct ifreq *); 176 static void bpf_timed_out(void *); 177 static __inline void 178 bpf_wakeup(struct bpf_d *); 179 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 180 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 181 struct bintime *); 182 static void reset_d(struct bpf_d *); 183 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 184 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 185 static int bpf_setdlt(struct bpf_d *, u_int); 186 static void filt_bpfdetach(struct knote *); 187 static int filt_bpfread(struct knote *, long); 188 static void bpf_drvinit(void *); 189 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 190 191 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 192 int bpf_maxinsns = BPF_MAXINSNS; 193 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 194 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 195 static int bpf_zerocopy_enable = 0; 196 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 197 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 198 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 199 bpf_stats_sysctl, "bpf statistics portal"); 200 201 static VNET_DEFINE(int, bpf_optimize_writers) = 0; 202 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 203 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RW, 204 &VNET_NAME(bpf_optimize_writers), 0, 205 "Do not send packets until BPF program is set"); 206 207 static d_open_t bpfopen; 208 static d_read_t bpfread; 209 static d_write_t bpfwrite; 210 static d_ioctl_t bpfioctl; 211 static d_poll_t bpfpoll; 212 static d_kqfilter_t bpfkqfilter; 213 214 static struct cdevsw bpf_cdevsw = { 215 .d_version = D_VERSION, 216 .d_open = bpfopen, 217 .d_read = bpfread, 218 .d_write = bpfwrite, 219 .d_ioctl = bpfioctl, 220 .d_poll = bpfpoll, 221 .d_name = "bpf", 222 .d_kqfilter = bpfkqfilter, 223 }; 224 225 static struct filterops bpfread_filtops = { 226 .f_isfd = 1, 227 .f_detach = filt_bpfdetach, 228 .f_event = filt_bpfread, 229 }; 230 231 eventhandler_tag bpf_ifdetach_cookie = NULL; 232 233 /* 234 * LOCKING MODEL USED BY BPF: 235 * Locks: 236 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal, 237 * some global counters and every bpf_if reference. 238 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters. 239 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields 240 * used by bpf_mtap code. 241 * 242 * Lock order: 243 * 244 * Global lock, interface lock, descriptor lock 245 * 246 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2] 247 * working model. In many places (like bpf_detachd) we start with BPF descriptor 248 * (and we need to at least rlock it to get reliable interface pointer). This 249 * gives us potential LOR. As a result, we use global lock to protect from bpf_if 250 * change in every such place. 251 * 252 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and 253 * 3) descriptor main wlock. 254 * Reading bd_bif can be protected by any of these locks, typically global lock. 255 * 256 * Changing read/write BPF filter is protected by the same three locks, 257 * the same applies for reading. 258 * 259 * Sleeping in global lock is not allowed due to bpfdetach() using it. 260 */ 261 262 /* 263 * Wrapper functions for various buffering methods. If the set of buffer 264 * modes expands, we will probably want to introduce a switch data structure 265 * similar to protosw, et. 266 */ 267 static void 268 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 269 u_int len) 270 { 271 272 BPFD_LOCK_ASSERT(d); 273 274 switch (d->bd_bufmode) { 275 case BPF_BUFMODE_BUFFER: 276 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 277 278 case BPF_BUFMODE_ZBUF: 279 d->bd_zcopy++; 280 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 281 282 default: 283 panic("bpf_buf_append_bytes"); 284 } 285 } 286 287 static void 288 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 289 u_int len) 290 { 291 292 BPFD_LOCK_ASSERT(d); 293 294 switch (d->bd_bufmode) { 295 case BPF_BUFMODE_BUFFER: 296 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 297 298 case BPF_BUFMODE_ZBUF: 299 d->bd_zcopy++; 300 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 301 302 default: 303 panic("bpf_buf_append_mbuf"); 304 } 305 } 306 307 /* 308 * This function gets called when the free buffer is re-assigned. 309 */ 310 static void 311 bpf_buf_reclaimed(struct bpf_d *d) 312 { 313 314 BPFD_LOCK_ASSERT(d); 315 316 switch (d->bd_bufmode) { 317 case BPF_BUFMODE_BUFFER: 318 return; 319 320 case BPF_BUFMODE_ZBUF: 321 bpf_zerocopy_buf_reclaimed(d); 322 return; 323 324 default: 325 panic("bpf_buf_reclaimed"); 326 } 327 } 328 329 /* 330 * If the buffer mechanism has a way to decide that a held buffer can be made 331 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 332 * returned if the buffer can be discarded, (0) is returned if it cannot. 333 */ 334 static int 335 bpf_canfreebuf(struct bpf_d *d) 336 { 337 338 BPFD_LOCK_ASSERT(d); 339 340 switch (d->bd_bufmode) { 341 case BPF_BUFMODE_ZBUF: 342 return (bpf_zerocopy_canfreebuf(d)); 343 } 344 return (0); 345 } 346 347 /* 348 * Allow the buffer model to indicate that the current store buffer is 349 * immutable, regardless of the appearance of space. Return (1) if the 350 * buffer is writable, and (0) if not. 351 */ 352 static int 353 bpf_canwritebuf(struct bpf_d *d) 354 { 355 BPFD_LOCK_ASSERT(d); 356 357 switch (d->bd_bufmode) { 358 case BPF_BUFMODE_ZBUF: 359 return (bpf_zerocopy_canwritebuf(d)); 360 } 361 return (1); 362 } 363 364 /* 365 * Notify buffer model that an attempt to write to the store buffer has 366 * resulted in a dropped packet, in which case the buffer may be considered 367 * full. 368 */ 369 static void 370 bpf_buffull(struct bpf_d *d) 371 { 372 373 BPFD_LOCK_ASSERT(d); 374 375 switch (d->bd_bufmode) { 376 case BPF_BUFMODE_ZBUF: 377 bpf_zerocopy_buffull(d); 378 break; 379 } 380 } 381 382 /* 383 * Notify the buffer model that a buffer has moved into the hold position. 384 */ 385 void 386 bpf_bufheld(struct bpf_d *d) 387 { 388 389 BPFD_LOCK_ASSERT(d); 390 391 switch (d->bd_bufmode) { 392 case BPF_BUFMODE_ZBUF: 393 bpf_zerocopy_bufheld(d); 394 break; 395 } 396 } 397 398 static void 399 bpf_free(struct bpf_d *d) 400 { 401 402 switch (d->bd_bufmode) { 403 case BPF_BUFMODE_BUFFER: 404 return (bpf_buffer_free(d)); 405 406 case BPF_BUFMODE_ZBUF: 407 return (bpf_zerocopy_free(d)); 408 409 default: 410 panic("bpf_buf_free"); 411 } 412 } 413 414 static int 415 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 416 { 417 418 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 419 return (EOPNOTSUPP); 420 return (bpf_buffer_uiomove(d, buf, len, uio)); 421 } 422 423 static int 424 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 425 { 426 427 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 428 return (EOPNOTSUPP); 429 return (bpf_buffer_ioctl_sblen(d, i)); 430 } 431 432 static int 433 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 434 { 435 436 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 437 return (EOPNOTSUPP); 438 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 439 } 440 441 static int 442 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 443 { 444 445 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 446 return (EOPNOTSUPP); 447 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 448 } 449 450 static int 451 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 452 { 453 454 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 455 return (EOPNOTSUPP); 456 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 457 } 458 459 /* 460 * General BPF functions. 461 */ 462 static int 463 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 464 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) 465 { 466 const struct ieee80211_bpf_params *p; 467 struct ether_header *eh; 468 struct mbuf *m; 469 int error; 470 int len; 471 int hlen; 472 int slen; 473 474 /* 475 * Build a sockaddr based on the data link layer type. 476 * We do this at this level because the ethernet header 477 * is copied directly into the data field of the sockaddr. 478 * In the case of SLIP, there is no header and the packet 479 * is forwarded as is. 480 * Also, we are careful to leave room at the front of the mbuf 481 * for the link level header. 482 */ 483 switch (linktype) { 484 485 case DLT_SLIP: 486 sockp->sa_family = AF_INET; 487 hlen = 0; 488 break; 489 490 case DLT_EN10MB: 491 sockp->sa_family = AF_UNSPEC; 492 /* XXX Would MAXLINKHDR be better? */ 493 hlen = ETHER_HDR_LEN; 494 break; 495 496 case DLT_FDDI: 497 sockp->sa_family = AF_IMPLINK; 498 hlen = 0; 499 break; 500 501 case DLT_RAW: 502 sockp->sa_family = AF_UNSPEC; 503 hlen = 0; 504 break; 505 506 case DLT_NULL: 507 /* 508 * null interface types require a 4 byte pseudo header which 509 * corresponds to the address family of the packet. 510 */ 511 sockp->sa_family = AF_UNSPEC; 512 hlen = 4; 513 break; 514 515 case DLT_ATM_RFC1483: 516 /* 517 * en atm driver requires 4-byte atm pseudo header. 518 * though it isn't standard, vpi:vci needs to be 519 * specified anyway. 520 */ 521 sockp->sa_family = AF_UNSPEC; 522 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 523 break; 524 525 case DLT_PPP: 526 sockp->sa_family = AF_UNSPEC; 527 hlen = 4; /* This should match PPP_HDRLEN */ 528 break; 529 530 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 531 sockp->sa_family = AF_IEEE80211; 532 hlen = 0; 533 break; 534 535 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 536 sockp->sa_family = AF_IEEE80211; 537 sockp->sa_len = 12; /* XXX != 0 */ 538 hlen = sizeof(struct ieee80211_bpf_params); 539 break; 540 541 default: 542 return (EIO); 543 } 544 545 len = uio->uio_resid; 546 if (len < hlen || len - hlen > ifp->if_mtu) 547 return (EMSGSIZE); 548 549 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR); 550 if (m == NULL) 551 return (EIO); 552 m->m_pkthdr.len = m->m_len = len; 553 *mp = m; 554 555 error = uiomove(mtod(m, u_char *), len, uio); 556 if (error) 557 goto bad; 558 559 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 560 if (slen == 0) { 561 error = EPERM; 562 goto bad; 563 } 564 565 /* Check for multicast destination */ 566 switch (linktype) { 567 case DLT_EN10MB: 568 eh = mtod(m, struct ether_header *); 569 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 570 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 571 ETHER_ADDR_LEN) == 0) 572 m->m_flags |= M_BCAST; 573 else 574 m->m_flags |= M_MCAST; 575 } 576 if (d->bd_hdrcmplt == 0) { 577 memcpy(eh->ether_shost, IF_LLADDR(ifp), 578 sizeof(eh->ether_shost)); 579 } 580 break; 581 } 582 583 /* 584 * Make room for link header, and copy it to sockaddr 585 */ 586 if (hlen != 0) { 587 if (sockp->sa_family == AF_IEEE80211) { 588 /* 589 * Collect true length from the parameter header 590 * NB: sockp is known to be zero'd so if we do a 591 * short copy unspecified parameters will be 592 * zero. 593 * NB: packet may not be aligned after stripping 594 * bpf params 595 * XXX check ibp_vers 596 */ 597 p = mtod(m, const struct ieee80211_bpf_params *); 598 hlen = p->ibp_len; 599 if (hlen > sizeof(sockp->sa_data)) { 600 error = EINVAL; 601 goto bad; 602 } 603 } 604 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 605 } 606 *hdrlen = hlen; 607 608 return (0); 609 bad: 610 m_freem(m); 611 return (error); 612 } 613 614 /* 615 * Attach file to the bpf interface, i.e. make d listen on bp. 616 */ 617 static void 618 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 619 { 620 int op_w; 621 622 BPF_LOCK_ASSERT(); 623 624 /* 625 * Save sysctl value to protect from sysctl change 626 * between reads 627 */ 628 op_w = V_bpf_optimize_writers || d->bd_writer; 629 630 if (d->bd_bif != NULL) 631 bpf_detachd_locked(d); 632 /* 633 * Point d at bp, and add d to the interface's list. 634 * Since there are many applications using BPF for 635 * sending raw packets only (dhcpd, cdpd are good examples) 636 * we can delay adding d to the list of active listeners until 637 * some filter is configured. 638 */ 639 640 BPFIF_WLOCK(bp); 641 BPFD_LOCK(d); 642 643 d->bd_bif = bp; 644 645 if (op_w != 0) { 646 /* Add to writers-only list */ 647 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 648 /* 649 * We decrement bd_writer on every filter set operation. 650 * First BIOCSETF is done by pcap_open_live() to set up 651 * snap length. After that appliation usually sets its own filter 652 */ 653 d->bd_writer = 2; 654 } else 655 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 656 657 BPFD_UNLOCK(d); 658 BPFIF_WUNLOCK(bp); 659 660 bpf_bpfd_cnt++; 661 662 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 663 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 664 665 if (op_w == 0) 666 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 667 } 668 669 /* 670 * Check if we need to upgrade our descriptor @d from write-only mode. 671 */ 672 static int 673 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen) 674 { 675 int is_snap, need_upgrade; 676 677 /* 678 * Check if we've already upgraded or new filter is empty. 679 */ 680 if (d->bd_writer == 0 || fcode == NULL) 681 return (0); 682 683 need_upgrade = 0; 684 685 /* 686 * Check if cmd looks like snaplen setting from 687 * pcap_bpf.c:pcap_open_live(). 688 * Note we're not checking .k value here: 689 * while pcap_open_live() definitely sets to to non-zero value, 690 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 691 * do not consider upgrading immediately 692 */ 693 if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K)) 694 is_snap = 1; 695 else 696 is_snap = 0; 697 698 if (is_snap == 0) { 699 /* 700 * We're setting first filter and it doesn't look like 701 * setting snaplen. We're probably using bpf directly. 702 * Upgrade immediately. 703 */ 704 need_upgrade = 1; 705 } else { 706 /* 707 * Do not require upgrade by first BIOCSETF 708 * (used to set snaplen) by pcap_open_live(). 709 */ 710 711 if (--d->bd_writer == 0) { 712 /* 713 * First snaplen filter has already 714 * been set. This is probably catch-all 715 * filter 716 */ 717 need_upgrade = 1; 718 } 719 } 720 721 CTR5(KTR_NET, 722 "%s: filter function set by pid %d, " 723 "bd_writer counter %d, snap %d upgrade %d", 724 __func__, d->bd_pid, d->bd_writer, 725 is_snap, need_upgrade); 726 727 return (need_upgrade); 728 } 729 730 /* 731 * Add d to the list of active bp filters. 732 * Requires bpf_attachd() to be called before. 733 */ 734 static void 735 bpf_upgraded(struct bpf_d *d) 736 { 737 struct bpf_if *bp; 738 739 BPF_LOCK_ASSERT(); 740 741 bp = d->bd_bif; 742 743 /* 744 * Filter can be set several times without specifying interface. 745 * Mark d as reader and exit. 746 */ 747 if (bp == NULL) { 748 BPFD_LOCK(d); 749 d->bd_writer = 0; 750 BPFD_UNLOCK(d); 751 return; 752 } 753 754 BPFIF_WLOCK(bp); 755 BPFD_LOCK(d); 756 757 /* Remove from writers-only list */ 758 LIST_REMOVE(d, bd_next); 759 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 760 /* Mark d as reader */ 761 d->bd_writer = 0; 762 763 BPFD_UNLOCK(d); 764 BPFIF_WUNLOCK(bp); 765 766 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid); 767 768 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 769 } 770 771 /* 772 * Detach a file from its interface. 773 */ 774 static void 775 bpf_detachd(struct bpf_d *d) 776 { 777 BPF_LOCK(); 778 bpf_detachd_locked(d); 779 BPF_UNLOCK(); 780 } 781 782 static void 783 bpf_detachd_locked(struct bpf_d *d) 784 { 785 int error; 786 struct bpf_if *bp; 787 struct ifnet *ifp; 788 789 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 790 791 BPF_LOCK_ASSERT(); 792 793 /* Check if descriptor is attached */ 794 if ((bp = d->bd_bif) == NULL) 795 return; 796 797 BPFIF_WLOCK(bp); 798 BPFD_LOCK(d); 799 800 /* Save bd_writer value */ 801 error = d->bd_writer; 802 803 /* 804 * Remove d from the interface's descriptor list. 805 */ 806 LIST_REMOVE(d, bd_next); 807 808 ifp = bp->bif_ifp; 809 d->bd_bif = NULL; 810 BPFD_UNLOCK(d); 811 BPFIF_WUNLOCK(bp); 812 813 bpf_bpfd_cnt--; 814 815 /* Call event handler iff d is attached */ 816 if (error == 0) 817 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 818 819 /* 820 * Check if this descriptor had requested promiscuous mode. 821 * If so, turn it off. 822 */ 823 if (d->bd_promisc) { 824 d->bd_promisc = 0; 825 CURVNET_SET(ifp->if_vnet); 826 error = ifpromisc(ifp, 0); 827 CURVNET_RESTORE(); 828 if (error != 0 && error != ENXIO) { 829 /* 830 * ENXIO can happen if a pccard is unplugged 831 * Something is really wrong if we were able to put 832 * the driver into promiscuous mode, but can't 833 * take it out. 834 */ 835 if_printf(bp->bif_ifp, 836 "bpf_detach: ifpromisc failed (%d)\n", error); 837 } 838 } 839 } 840 841 /* 842 * Close the descriptor by detaching it from its interface, 843 * deallocating its buffers, and marking it free. 844 */ 845 static void 846 bpf_dtor(void *data) 847 { 848 struct bpf_d *d = data; 849 850 BPFD_LOCK(d); 851 if (d->bd_state == BPF_WAITING) 852 callout_stop(&d->bd_callout); 853 d->bd_state = BPF_IDLE; 854 BPFD_UNLOCK(d); 855 funsetown(&d->bd_sigio); 856 bpf_detachd(d); 857 #ifdef MAC 858 mac_bpfdesc_destroy(d); 859 #endif /* MAC */ 860 seldrain(&d->bd_sel); 861 knlist_destroy(&d->bd_sel.si_note); 862 callout_drain(&d->bd_callout); 863 bpf_freed(d); 864 free(d, M_BPF); 865 } 866 867 /* 868 * Open ethernet device. Returns ENXIO for illegal minor device number, 869 * EBUSY if file is open by another process. 870 */ 871 /* ARGSUSED */ 872 static int 873 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 874 { 875 struct bpf_d *d; 876 int error; 877 878 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 879 error = devfs_set_cdevpriv(d, bpf_dtor); 880 if (error != 0) { 881 free(d, M_BPF); 882 return (error); 883 } 884 885 /* 886 * For historical reasons, perform a one-time initialization call to 887 * the buffer routines, even though we're not yet committed to a 888 * particular buffer method. 889 */ 890 bpf_buffer_init(d); 891 if ((flags & FREAD) == 0) 892 d->bd_writer = 2; 893 d->bd_hbuf_in_use = 0; 894 d->bd_bufmode = BPF_BUFMODE_BUFFER; 895 d->bd_sig = SIGIO; 896 d->bd_direction = BPF_D_INOUT; 897 BPF_PID_REFRESH(d, td); 898 #ifdef MAC 899 mac_bpfdesc_init(d); 900 mac_bpfdesc_create(td->td_ucred, d); 901 #endif 902 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 903 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 904 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 905 906 return (0); 907 } 908 909 /* 910 * bpfread - read next chunk of packets from buffers 911 */ 912 static int 913 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 914 { 915 struct bpf_d *d; 916 int error; 917 int non_block; 918 int timed_out; 919 920 error = devfs_get_cdevpriv((void **)&d); 921 if (error != 0) 922 return (error); 923 924 /* 925 * Restrict application to use a buffer the same size as 926 * as kernel buffers. 927 */ 928 if (uio->uio_resid != d->bd_bufsize) 929 return (EINVAL); 930 931 non_block = ((ioflag & O_NONBLOCK) != 0); 932 933 BPFD_LOCK(d); 934 BPF_PID_REFRESH_CUR(d); 935 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 936 BPFD_UNLOCK(d); 937 return (EOPNOTSUPP); 938 } 939 if (d->bd_state == BPF_WAITING) 940 callout_stop(&d->bd_callout); 941 timed_out = (d->bd_state == BPF_TIMED_OUT); 942 d->bd_state = BPF_IDLE; 943 while (d->bd_hbuf_in_use) { 944 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 945 PRINET|PCATCH, "bd_hbuf", 0); 946 if (error != 0) { 947 BPFD_UNLOCK(d); 948 return (error); 949 } 950 } 951 /* 952 * If the hold buffer is empty, then do a timed sleep, which 953 * ends when the timeout expires or when enough packets 954 * have arrived to fill the store buffer. 955 */ 956 while (d->bd_hbuf == NULL) { 957 if (d->bd_slen != 0) { 958 /* 959 * A packet(s) either arrived since the previous 960 * read or arrived while we were asleep. 961 */ 962 if (d->bd_immediate || non_block || timed_out) { 963 /* 964 * Rotate the buffers and return what's here 965 * if we are in immediate mode, non-blocking 966 * flag is set, or this descriptor timed out. 967 */ 968 ROTATE_BUFFERS(d); 969 break; 970 } 971 } 972 973 /* 974 * No data is available, check to see if the bpf device 975 * is still pointed at a real interface. If not, return 976 * ENXIO so that the userland process knows to rebind 977 * it before using it again. 978 */ 979 if (d->bd_bif == NULL) { 980 BPFD_UNLOCK(d); 981 return (ENXIO); 982 } 983 984 if (non_block) { 985 BPFD_UNLOCK(d); 986 return (EWOULDBLOCK); 987 } 988 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 989 "bpf", d->bd_rtout); 990 if (error == EINTR || error == ERESTART) { 991 BPFD_UNLOCK(d); 992 return (error); 993 } 994 if (error == EWOULDBLOCK) { 995 /* 996 * On a timeout, return what's in the buffer, 997 * which may be nothing. If there is something 998 * in the store buffer, we can rotate the buffers. 999 */ 1000 if (d->bd_hbuf) 1001 /* 1002 * We filled up the buffer in between 1003 * getting the timeout and arriving 1004 * here, so we don't need to rotate. 1005 */ 1006 break; 1007 1008 if (d->bd_slen == 0) { 1009 BPFD_UNLOCK(d); 1010 return (0); 1011 } 1012 ROTATE_BUFFERS(d); 1013 break; 1014 } 1015 } 1016 /* 1017 * At this point, we know we have something in the hold slot. 1018 */ 1019 d->bd_hbuf_in_use = 1; 1020 BPFD_UNLOCK(d); 1021 1022 /* 1023 * Move data from hold buffer into user space. 1024 * We know the entire buffer is transferred since 1025 * we checked above that the read buffer is bpf_bufsize bytes. 1026 * 1027 * We do not have to worry about simultaneous reads because 1028 * we waited for sole access to the hold buffer above. 1029 */ 1030 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1031 1032 BPFD_LOCK(d); 1033 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1034 d->bd_fbuf = d->bd_hbuf; 1035 d->bd_hbuf = NULL; 1036 d->bd_hlen = 0; 1037 bpf_buf_reclaimed(d); 1038 d->bd_hbuf_in_use = 0; 1039 wakeup(&d->bd_hbuf_in_use); 1040 BPFD_UNLOCK(d); 1041 1042 return (error); 1043 } 1044 1045 /* 1046 * If there are processes sleeping on this descriptor, wake them up. 1047 */ 1048 static __inline void 1049 bpf_wakeup(struct bpf_d *d) 1050 { 1051 1052 BPFD_LOCK_ASSERT(d); 1053 if (d->bd_state == BPF_WAITING) { 1054 callout_stop(&d->bd_callout); 1055 d->bd_state = BPF_IDLE; 1056 } 1057 wakeup(d); 1058 if (d->bd_async && d->bd_sig && d->bd_sigio) 1059 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1060 1061 selwakeuppri(&d->bd_sel, PRINET); 1062 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1063 } 1064 1065 static void 1066 bpf_timed_out(void *arg) 1067 { 1068 struct bpf_d *d = (struct bpf_d *)arg; 1069 1070 BPFD_LOCK_ASSERT(d); 1071 1072 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) 1073 return; 1074 if (d->bd_state == BPF_WAITING) { 1075 d->bd_state = BPF_TIMED_OUT; 1076 if (d->bd_slen != 0) 1077 bpf_wakeup(d); 1078 } 1079 } 1080 1081 static int 1082 bpf_ready(struct bpf_d *d) 1083 { 1084 1085 BPFD_LOCK_ASSERT(d); 1086 1087 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1088 return (1); 1089 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1090 d->bd_slen != 0) 1091 return (1); 1092 return (0); 1093 } 1094 1095 static int 1096 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1097 { 1098 struct bpf_d *d; 1099 struct ifnet *ifp; 1100 struct mbuf *m, *mc; 1101 struct sockaddr dst; 1102 struct route ro; 1103 int error, hlen; 1104 1105 error = devfs_get_cdevpriv((void **)&d); 1106 if (error != 0) 1107 return (error); 1108 1109 BPF_PID_REFRESH_CUR(d); 1110 d->bd_wcount++; 1111 /* XXX: locking required */ 1112 if (d->bd_bif == NULL) { 1113 d->bd_wdcount++; 1114 return (ENXIO); 1115 } 1116 1117 ifp = d->bd_bif->bif_ifp; 1118 1119 if ((ifp->if_flags & IFF_UP) == 0) { 1120 d->bd_wdcount++; 1121 return (ENETDOWN); 1122 } 1123 1124 if (uio->uio_resid == 0) { 1125 d->bd_wdcount++; 1126 return (0); 1127 } 1128 1129 bzero(&dst, sizeof(dst)); 1130 m = NULL; 1131 hlen = 0; 1132 /* XXX: bpf_movein() can sleep */ 1133 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 1134 &m, &dst, &hlen, d); 1135 if (error) { 1136 d->bd_wdcount++; 1137 return (error); 1138 } 1139 d->bd_wfcount++; 1140 if (d->bd_hdrcmplt) 1141 dst.sa_family = pseudo_AF_HDRCMPLT; 1142 1143 if (d->bd_feedback) { 1144 mc = m_dup(m, M_NOWAIT); 1145 if (mc != NULL) 1146 mc->m_pkthdr.rcvif = ifp; 1147 /* Set M_PROMISC for outgoing packets to be discarded. */ 1148 if (d->bd_direction == BPF_D_INOUT) 1149 m->m_flags |= M_PROMISC; 1150 } else 1151 mc = NULL; 1152 1153 m->m_pkthdr.len -= hlen; 1154 m->m_len -= hlen; 1155 m->m_data += hlen; /* XXX */ 1156 1157 CURVNET_SET(ifp->if_vnet); 1158 #ifdef MAC 1159 BPFD_LOCK(d); 1160 mac_bpfdesc_create_mbuf(d, m); 1161 if (mc != NULL) 1162 mac_bpfdesc_create_mbuf(d, mc); 1163 BPFD_UNLOCK(d); 1164 #endif 1165 1166 bzero(&ro, sizeof(ro)); 1167 if (hlen != 0) { 1168 ro.ro_prepend = (u_char *)&dst.sa_data; 1169 ro.ro_plen = hlen; 1170 ro.ro_flags = RT_HAS_HEADER; 1171 } 1172 1173 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1174 if (error) 1175 d->bd_wdcount++; 1176 1177 if (mc != NULL) { 1178 if (error == 0) 1179 (*ifp->if_input)(ifp, mc); 1180 else 1181 m_freem(mc); 1182 } 1183 CURVNET_RESTORE(); 1184 1185 return (error); 1186 } 1187 1188 /* 1189 * Reset a descriptor by flushing its packet buffer and clearing the receive 1190 * and drop counts. This is doable for kernel-only buffers, but with 1191 * zero-copy buffers, we can't write to (or rotate) buffers that are 1192 * currently owned by userspace. It would be nice if we could encapsulate 1193 * this logic in the buffer code rather than here. 1194 */ 1195 static void 1196 reset_d(struct bpf_d *d) 1197 { 1198 1199 BPFD_LOCK_ASSERT(d); 1200 1201 while (d->bd_hbuf_in_use) 1202 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1203 "bd_hbuf", 0); 1204 if ((d->bd_hbuf != NULL) && 1205 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1206 /* Free the hold buffer. */ 1207 d->bd_fbuf = d->bd_hbuf; 1208 d->bd_hbuf = NULL; 1209 d->bd_hlen = 0; 1210 bpf_buf_reclaimed(d); 1211 } 1212 if (bpf_canwritebuf(d)) 1213 d->bd_slen = 0; 1214 d->bd_rcount = 0; 1215 d->bd_dcount = 0; 1216 d->bd_fcount = 0; 1217 d->bd_wcount = 0; 1218 d->bd_wfcount = 0; 1219 d->bd_wdcount = 0; 1220 d->bd_zcopy = 0; 1221 } 1222 1223 /* 1224 * FIONREAD Check for read packet available. 1225 * BIOCGBLEN Get buffer len [for read()]. 1226 * BIOCSETF Set read filter. 1227 * BIOCSETFNR Set read filter without resetting descriptor. 1228 * BIOCSETWF Set write filter. 1229 * BIOCFLUSH Flush read packet buffer. 1230 * BIOCPROMISC Put interface into promiscuous mode. 1231 * BIOCGDLT Get link layer type. 1232 * BIOCGETIF Get interface name. 1233 * BIOCSETIF Set interface. 1234 * BIOCSRTIMEOUT Set read timeout. 1235 * BIOCGRTIMEOUT Get read timeout. 1236 * BIOCGSTATS Get packet stats. 1237 * BIOCIMMEDIATE Set immediate mode. 1238 * BIOCVERSION Get filter language version. 1239 * BIOCGHDRCMPLT Get "header already complete" flag 1240 * BIOCSHDRCMPLT Set "header already complete" flag 1241 * BIOCGDIRECTION Get packet direction flag 1242 * BIOCSDIRECTION Set packet direction flag 1243 * BIOCGTSTAMP Get time stamp format and resolution. 1244 * BIOCSTSTAMP Set time stamp format and resolution. 1245 * BIOCLOCK Set "locked" flag 1246 * BIOCFEEDBACK Set packet feedback mode. 1247 * BIOCSETZBUF Set current zero-copy buffer locations. 1248 * BIOCGETZMAX Get maximum zero-copy buffer size. 1249 * BIOCROTZBUF Force rotation of zero-copy buffer 1250 * BIOCSETBUFMODE Set buffer mode. 1251 * BIOCGETBUFMODE Get current buffer mode. 1252 */ 1253 /* ARGSUSED */ 1254 static int 1255 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1256 struct thread *td) 1257 { 1258 struct bpf_d *d; 1259 int error; 1260 1261 error = devfs_get_cdevpriv((void **)&d); 1262 if (error != 0) 1263 return (error); 1264 1265 /* 1266 * Refresh PID associated with this descriptor. 1267 */ 1268 BPFD_LOCK(d); 1269 BPF_PID_REFRESH(d, td); 1270 if (d->bd_state == BPF_WAITING) 1271 callout_stop(&d->bd_callout); 1272 d->bd_state = BPF_IDLE; 1273 BPFD_UNLOCK(d); 1274 1275 if (d->bd_locked == 1) { 1276 switch (cmd) { 1277 case BIOCGBLEN: 1278 case BIOCFLUSH: 1279 case BIOCGDLT: 1280 case BIOCGDLTLIST: 1281 #ifdef COMPAT_FREEBSD32 1282 case BIOCGDLTLIST32: 1283 #endif 1284 case BIOCGETIF: 1285 case BIOCGRTIMEOUT: 1286 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1287 case BIOCGRTIMEOUT32: 1288 #endif 1289 case BIOCGSTATS: 1290 case BIOCVERSION: 1291 case BIOCGRSIG: 1292 case BIOCGHDRCMPLT: 1293 case BIOCSTSTAMP: 1294 case BIOCFEEDBACK: 1295 case FIONREAD: 1296 case BIOCLOCK: 1297 case BIOCSRTIMEOUT: 1298 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1299 case BIOCSRTIMEOUT32: 1300 #endif 1301 case BIOCIMMEDIATE: 1302 case TIOCGPGRP: 1303 case BIOCROTZBUF: 1304 break; 1305 default: 1306 return (EPERM); 1307 } 1308 } 1309 #ifdef COMPAT_FREEBSD32 1310 /* 1311 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1312 * that it will get 32-bit packet headers. 1313 */ 1314 switch (cmd) { 1315 case BIOCSETF32: 1316 case BIOCSETFNR32: 1317 case BIOCSETWF32: 1318 case BIOCGDLTLIST32: 1319 case BIOCGRTIMEOUT32: 1320 case BIOCSRTIMEOUT32: 1321 BPFD_LOCK(d); 1322 d->bd_compat32 = 1; 1323 BPFD_UNLOCK(d); 1324 } 1325 #endif 1326 1327 CURVNET_SET(TD_TO_VNET(td)); 1328 switch (cmd) { 1329 1330 default: 1331 error = EINVAL; 1332 break; 1333 1334 /* 1335 * Check for read packet available. 1336 */ 1337 case FIONREAD: 1338 { 1339 int n; 1340 1341 BPFD_LOCK(d); 1342 n = d->bd_slen; 1343 while (d->bd_hbuf_in_use) 1344 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1345 PRINET, "bd_hbuf", 0); 1346 if (d->bd_hbuf) 1347 n += d->bd_hlen; 1348 BPFD_UNLOCK(d); 1349 1350 *(int *)addr = n; 1351 break; 1352 } 1353 1354 /* 1355 * Get buffer len [for read()]. 1356 */ 1357 case BIOCGBLEN: 1358 BPFD_LOCK(d); 1359 *(u_int *)addr = d->bd_bufsize; 1360 BPFD_UNLOCK(d); 1361 break; 1362 1363 /* 1364 * Set buffer length. 1365 */ 1366 case BIOCSBLEN: 1367 error = bpf_ioctl_sblen(d, (u_int *)addr); 1368 break; 1369 1370 /* 1371 * Set link layer read filter. 1372 */ 1373 case BIOCSETF: 1374 case BIOCSETFNR: 1375 case BIOCSETWF: 1376 #ifdef COMPAT_FREEBSD32 1377 case BIOCSETF32: 1378 case BIOCSETFNR32: 1379 case BIOCSETWF32: 1380 #endif 1381 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1382 break; 1383 1384 /* 1385 * Flush read packet buffer. 1386 */ 1387 case BIOCFLUSH: 1388 BPFD_LOCK(d); 1389 reset_d(d); 1390 BPFD_UNLOCK(d); 1391 break; 1392 1393 /* 1394 * Put interface into promiscuous mode. 1395 */ 1396 case BIOCPROMISC: 1397 if (d->bd_bif == NULL) { 1398 /* 1399 * No interface attached yet. 1400 */ 1401 error = EINVAL; 1402 break; 1403 } 1404 if (d->bd_promisc == 0) { 1405 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1406 if (error == 0) 1407 d->bd_promisc = 1; 1408 } 1409 break; 1410 1411 /* 1412 * Get current data link type. 1413 */ 1414 case BIOCGDLT: 1415 BPF_LOCK(); 1416 if (d->bd_bif == NULL) 1417 error = EINVAL; 1418 else 1419 *(u_int *)addr = d->bd_bif->bif_dlt; 1420 BPF_UNLOCK(); 1421 break; 1422 1423 /* 1424 * Get a list of supported data link types. 1425 */ 1426 #ifdef COMPAT_FREEBSD32 1427 case BIOCGDLTLIST32: 1428 { 1429 struct bpf_dltlist32 *list32; 1430 struct bpf_dltlist dltlist; 1431 1432 list32 = (struct bpf_dltlist32 *)addr; 1433 dltlist.bfl_len = list32->bfl_len; 1434 dltlist.bfl_list = PTRIN(list32->bfl_list); 1435 BPF_LOCK(); 1436 if (d->bd_bif == NULL) 1437 error = EINVAL; 1438 else { 1439 error = bpf_getdltlist(d, &dltlist); 1440 if (error == 0) 1441 list32->bfl_len = dltlist.bfl_len; 1442 } 1443 BPF_UNLOCK(); 1444 break; 1445 } 1446 #endif 1447 1448 case BIOCGDLTLIST: 1449 BPF_LOCK(); 1450 if (d->bd_bif == NULL) 1451 error = EINVAL; 1452 else 1453 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1454 BPF_UNLOCK(); 1455 break; 1456 1457 /* 1458 * Set data link type. 1459 */ 1460 case BIOCSDLT: 1461 BPF_LOCK(); 1462 if (d->bd_bif == NULL) 1463 error = EINVAL; 1464 else 1465 error = bpf_setdlt(d, *(u_int *)addr); 1466 BPF_UNLOCK(); 1467 break; 1468 1469 /* 1470 * Get interface name. 1471 */ 1472 case BIOCGETIF: 1473 BPF_LOCK(); 1474 if (d->bd_bif == NULL) 1475 error = EINVAL; 1476 else { 1477 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1478 struct ifreq *const ifr = (struct ifreq *)addr; 1479 1480 strlcpy(ifr->ifr_name, ifp->if_xname, 1481 sizeof(ifr->ifr_name)); 1482 } 1483 BPF_UNLOCK(); 1484 break; 1485 1486 /* 1487 * Set interface. 1488 */ 1489 case BIOCSETIF: 1490 { 1491 int alloc_buf, size; 1492 1493 /* 1494 * Behavior here depends on the buffering model. If 1495 * we're using kernel memory buffers, then we can 1496 * allocate them here. If we're using zero-copy, 1497 * then the user process must have registered buffers 1498 * by the time we get here. 1499 */ 1500 alloc_buf = 0; 1501 BPFD_LOCK(d); 1502 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1503 d->bd_sbuf == NULL) 1504 alloc_buf = 1; 1505 BPFD_UNLOCK(d); 1506 if (alloc_buf) { 1507 size = d->bd_bufsize; 1508 error = bpf_buffer_ioctl_sblen(d, &size); 1509 if (error != 0) 1510 break; 1511 } 1512 BPF_LOCK(); 1513 error = bpf_setif(d, (struct ifreq *)addr); 1514 BPF_UNLOCK(); 1515 break; 1516 } 1517 1518 /* 1519 * Set read timeout. 1520 */ 1521 case BIOCSRTIMEOUT: 1522 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1523 case BIOCSRTIMEOUT32: 1524 #endif 1525 { 1526 struct timeval *tv = (struct timeval *)addr; 1527 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1528 struct timeval32 *tv32; 1529 struct timeval tv64; 1530 1531 if (cmd == BIOCSRTIMEOUT32) { 1532 tv32 = (struct timeval32 *)addr; 1533 tv = &tv64; 1534 tv->tv_sec = tv32->tv_sec; 1535 tv->tv_usec = tv32->tv_usec; 1536 } else 1537 #endif 1538 tv = (struct timeval *)addr; 1539 1540 /* 1541 * Subtract 1 tick from tvtohz() since this isn't 1542 * a one-shot timer. 1543 */ 1544 if ((error = itimerfix(tv)) == 0) 1545 d->bd_rtout = tvtohz(tv) - 1; 1546 break; 1547 } 1548 1549 /* 1550 * Get read timeout. 1551 */ 1552 case BIOCGRTIMEOUT: 1553 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1554 case BIOCGRTIMEOUT32: 1555 #endif 1556 { 1557 struct timeval *tv; 1558 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1559 struct timeval32 *tv32; 1560 struct timeval tv64; 1561 1562 if (cmd == BIOCGRTIMEOUT32) 1563 tv = &tv64; 1564 else 1565 #endif 1566 tv = (struct timeval *)addr; 1567 1568 tv->tv_sec = d->bd_rtout / hz; 1569 tv->tv_usec = (d->bd_rtout % hz) * tick; 1570 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1571 if (cmd == BIOCGRTIMEOUT32) { 1572 tv32 = (struct timeval32 *)addr; 1573 tv32->tv_sec = tv->tv_sec; 1574 tv32->tv_usec = tv->tv_usec; 1575 } 1576 #endif 1577 1578 break; 1579 } 1580 1581 /* 1582 * Get packet stats. 1583 */ 1584 case BIOCGSTATS: 1585 { 1586 struct bpf_stat *bs = (struct bpf_stat *)addr; 1587 1588 /* XXXCSJP overflow */ 1589 bs->bs_recv = d->bd_rcount; 1590 bs->bs_drop = d->bd_dcount; 1591 break; 1592 } 1593 1594 /* 1595 * Set immediate mode. 1596 */ 1597 case BIOCIMMEDIATE: 1598 BPFD_LOCK(d); 1599 d->bd_immediate = *(u_int *)addr; 1600 BPFD_UNLOCK(d); 1601 break; 1602 1603 case BIOCVERSION: 1604 { 1605 struct bpf_version *bv = (struct bpf_version *)addr; 1606 1607 bv->bv_major = BPF_MAJOR_VERSION; 1608 bv->bv_minor = BPF_MINOR_VERSION; 1609 break; 1610 } 1611 1612 /* 1613 * Get "header already complete" flag 1614 */ 1615 case BIOCGHDRCMPLT: 1616 BPFD_LOCK(d); 1617 *(u_int *)addr = d->bd_hdrcmplt; 1618 BPFD_UNLOCK(d); 1619 break; 1620 1621 /* 1622 * Set "header already complete" flag 1623 */ 1624 case BIOCSHDRCMPLT: 1625 BPFD_LOCK(d); 1626 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1627 BPFD_UNLOCK(d); 1628 break; 1629 1630 /* 1631 * Get packet direction flag 1632 */ 1633 case BIOCGDIRECTION: 1634 BPFD_LOCK(d); 1635 *(u_int *)addr = d->bd_direction; 1636 BPFD_UNLOCK(d); 1637 break; 1638 1639 /* 1640 * Set packet direction flag 1641 */ 1642 case BIOCSDIRECTION: 1643 { 1644 u_int direction; 1645 1646 direction = *(u_int *)addr; 1647 switch (direction) { 1648 case BPF_D_IN: 1649 case BPF_D_INOUT: 1650 case BPF_D_OUT: 1651 BPFD_LOCK(d); 1652 d->bd_direction = direction; 1653 BPFD_UNLOCK(d); 1654 break; 1655 default: 1656 error = EINVAL; 1657 } 1658 } 1659 break; 1660 1661 /* 1662 * Get packet timestamp format and resolution. 1663 */ 1664 case BIOCGTSTAMP: 1665 BPFD_LOCK(d); 1666 *(u_int *)addr = d->bd_tstamp; 1667 BPFD_UNLOCK(d); 1668 break; 1669 1670 /* 1671 * Set packet timestamp format and resolution. 1672 */ 1673 case BIOCSTSTAMP: 1674 { 1675 u_int func; 1676 1677 func = *(u_int *)addr; 1678 if (BPF_T_VALID(func)) 1679 d->bd_tstamp = func; 1680 else 1681 error = EINVAL; 1682 } 1683 break; 1684 1685 case BIOCFEEDBACK: 1686 BPFD_LOCK(d); 1687 d->bd_feedback = *(u_int *)addr; 1688 BPFD_UNLOCK(d); 1689 break; 1690 1691 case BIOCLOCK: 1692 BPFD_LOCK(d); 1693 d->bd_locked = 1; 1694 BPFD_UNLOCK(d); 1695 break; 1696 1697 case FIONBIO: /* Non-blocking I/O */ 1698 break; 1699 1700 case FIOASYNC: /* Send signal on receive packets */ 1701 BPFD_LOCK(d); 1702 d->bd_async = *(int *)addr; 1703 BPFD_UNLOCK(d); 1704 break; 1705 1706 case FIOSETOWN: 1707 /* 1708 * XXX: Add some sort of locking here? 1709 * fsetown() can sleep. 1710 */ 1711 error = fsetown(*(int *)addr, &d->bd_sigio); 1712 break; 1713 1714 case FIOGETOWN: 1715 BPFD_LOCK(d); 1716 *(int *)addr = fgetown(&d->bd_sigio); 1717 BPFD_UNLOCK(d); 1718 break; 1719 1720 /* This is deprecated, FIOSETOWN should be used instead. */ 1721 case TIOCSPGRP: 1722 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1723 break; 1724 1725 /* This is deprecated, FIOGETOWN should be used instead. */ 1726 case TIOCGPGRP: 1727 *(int *)addr = -fgetown(&d->bd_sigio); 1728 break; 1729 1730 case BIOCSRSIG: /* Set receive signal */ 1731 { 1732 u_int sig; 1733 1734 sig = *(u_int *)addr; 1735 1736 if (sig >= NSIG) 1737 error = EINVAL; 1738 else { 1739 BPFD_LOCK(d); 1740 d->bd_sig = sig; 1741 BPFD_UNLOCK(d); 1742 } 1743 break; 1744 } 1745 case BIOCGRSIG: 1746 BPFD_LOCK(d); 1747 *(u_int *)addr = d->bd_sig; 1748 BPFD_UNLOCK(d); 1749 break; 1750 1751 case BIOCGETBUFMODE: 1752 BPFD_LOCK(d); 1753 *(u_int *)addr = d->bd_bufmode; 1754 BPFD_UNLOCK(d); 1755 break; 1756 1757 case BIOCSETBUFMODE: 1758 /* 1759 * Allow the buffering mode to be changed as long as we 1760 * haven't yet committed to a particular mode. Our 1761 * definition of commitment, for now, is whether or not a 1762 * buffer has been allocated or an interface attached, since 1763 * that's the point where things get tricky. 1764 */ 1765 switch (*(u_int *)addr) { 1766 case BPF_BUFMODE_BUFFER: 1767 break; 1768 1769 case BPF_BUFMODE_ZBUF: 1770 if (bpf_zerocopy_enable) 1771 break; 1772 /* FALLSTHROUGH */ 1773 1774 default: 1775 CURVNET_RESTORE(); 1776 return (EINVAL); 1777 } 1778 1779 BPFD_LOCK(d); 1780 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1781 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1782 BPFD_UNLOCK(d); 1783 CURVNET_RESTORE(); 1784 return (EBUSY); 1785 } 1786 d->bd_bufmode = *(u_int *)addr; 1787 BPFD_UNLOCK(d); 1788 break; 1789 1790 case BIOCGETZMAX: 1791 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1792 break; 1793 1794 case BIOCSETZBUF: 1795 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1796 break; 1797 1798 case BIOCROTZBUF: 1799 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1800 break; 1801 } 1802 CURVNET_RESTORE(); 1803 return (error); 1804 } 1805 1806 /* 1807 * Set d's packet filter program to fp. If this file already has a filter, 1808 * free it and replace it. Returns EINVAL for bogus requests. 1809 * 1810 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls 1811 * since reading d->bd_bif can't be protected by d or interface lock due to 1812 * lock order. 1813 * 1814 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses 1815 * interface read lock to read all filers. 1816 * 1817 */ 1818 static int 1819 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1820 { 1821 #ifdef COMPAT_FREEBSD32 1822 struct bpf_program fp_swab; 1823 struct bpf_program32 *fp32; 1824 #endif 1825 struct bpf_insn *fcode, *old; 1826 #ifdef BPF_JITTER 1827 bpf_jit_filter *jfunc, *ofunc; 1828 #endif 1829 size_t size; 1830 u_int flen; 1831 int need_upgrade; 1832 1833 #ifdef COMPAT_FREEBSD32 1834 switch (cmd) { 1835 case BIOCSETF32: 1836 case BIOCSETWF32: 1837 case BIOCSETFNR32: 1838 fp32 = (struct bpf_program32 *)fp; 1839 fp_swab.bf_len = fp32->bf_len; 1840 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1841 fp = &fp_swab; 1842 switch (cmd) { 1843 case BIOCSETF32: 1844 cmd = BIOCSETF; 1845 break; 1846 case BIOCSETWF32: 1847 cmd = BIOCSETWF; 1848 break; 1849 } 1850 break; 1851 } 1852 #endif 1853 1854 fcode = NULL; 1855 #ifdef BPF_JITTER 1856 jfunc = ofunc = NULL; 1857 #endif 1858 need_upgrade = 0; 1859 1860 /* 1861 * Check new filter validness before acquiring any locks. 1862 * Allocate memory for new filter, if needed. 1863 */ 1864 flen = fp->bf_len; 1865 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1866 return (EINVAL); 1867 size = flen * sizeof(*fp->bf_insns); 1868 if (size > 0) { 1869 /* We're setting up new filter. Copy and check actual data. */ 1870 fcode = malloc(size, M_BPF, M_WAITOK); 1871 if (copyin(fp->bf_insns, fcode, size) != 0 || 1872 !bpf_validate(fcode, flen)) { 1873 free(fcode, M_BPF); 1874 return (EINVAL); 1875 } 1876 #ifdef BPF_JITTER 1877 /* Filter is copied inside fcode and is perfectly valid. */ 1878 jfunc = bpf_jitter(fcode, flen); 1879 #endif 1880 } 1881 1882 BPF_LOCK(); 1883 1884 /* 1885 * Set up new filter. 1886 * Protect filter change by interface lock. 1887 * Additionally, we are protected by global lock here. 1888 */ 1889 if (d->bd_bif != NULL) 1890 BPFIF_WLOCK(d->bd_bif); 1891 BPFD_LOCK(d); 1892 if (cmd == BIOCSETWF) { 1893 old = d->bd_wfilter; 1894 d->bd_wfilter = fcode; 1895 } else { 1896 old = d->bd_rfilter; 1897 d->bd_rfilter = fcode; 1898 #ifdef BPF_JITTER 1899 ofunc = d->bd_bfilter; 1900 d->bd_bfilter = jfunc; 1901 #endif 1902 if (cmd == BIOCSETF) 1903 reset_d(d); 1904 1905 need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen); 1906 } 1907 BPFD_UNLOCK(d); 1908 if (d->bd_bif != NULL) 1909 BPFIF_WUNLOCK(d->bd_bif); 1910 if (old != NULL) 1911 free(old, M_BPF); 1912 #ifdef BPF_JITTER 1913 if (ofunc != NULL) 1914 bpf_destroy_jit_filter(ofunc); 1915 #endif 1916 1917 /* Move d to active readers list. */ 1918 if (need_upgrade != 0) 1919 bpf_upgraded(d); 1920 1921 BPF_UNLOCK(); 1922 return (0); 1923 } 1924 1925 /* 1926 * Detach a file from its current interface (if attached at all) and attach 1927 * to the interface indicated by the name stored in ifr. 1928 * Return an errno or 0. 1929 */ 1930 static int 1931 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1932 { 1933 struct bpf_if *bp; 1934 struct ifnet *theywant; 1935 1936 BPF_LOCK_ASSERT(); 1937 1938 theywant = ifunit(ifr->ifr_name); 1939 if (theywant == NULL || theywant->if_bpf == NULL) 1940 return (ENXIO); 1941 1942 bp = theywant->if_bpf; 1943 1944 /* Check if interface is not being detached from BPF */ 1945 BPFIF_RLOCK(bp); 1946 if (bp->bif_flags & BPFIF_FLAG_DYING) { 1947 BPFIF_RUNLOCK(bp); 1948 return (ENXIO); 1949 } 1950 BPFIF_RUNLOCK(bp); 1951 1952 /* 1953 * At this point, we expect the buffer is already allocated. If not, 1954 * return an error. 1955 */ 1956 switch (d->bd_bufmode) { 1957 case BPF_BUFMODE_BUFFER: 1958 case BPF_BUFMODE_ZBUF: 1959 if (d->bd_sbuf == NULL) 1960 return (EINVAL); 1961 break; 1962 1963 default: 1964 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1965 } 1966 if (bp != d->bd_bif) 1967 bpf_attachd(d, bp); 1968 BPFD_LOCK(d); 1969 reset_d(d); 1970 BPFD_UNLOCK(d); 1971 return (0); 1972 } 1973 1974 /* 1975 * Support for select() and poll() system calls 1976 * 1977 * Return true iff the specific operation will not block indefinitely. 1978 * Otherwise, return false but make a note that a selwakeup() must be done. 1979 */ 1980 static int 1981 bpfpoll(struct cdev *dev, int events, struct thread *td) 1982 { 1983 struct bpf_d *d; 1984 int revents; 1985 1986 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 1987 return (events & 1988 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 1989 1990 /* 1991 * Refresh PID associated with this descriptor. 1992 */ 1993 revents = events & (POLLOUT | POLLWRNORM); 1994 BPFD_LOCK(d); 1995 BPF_PID_REFRESH(d, td); 1996 if (events & (POLLIN | POLLRDNORM)) { 1997 if (bpf_ready(d)) 1998 revents |= events & (POLLIN | POLLRDNORM); 1999 else { 2000 selrecord(td, &d->bd_sel); 2001 /* Start the read timeout if necessary. */ 2002 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2003 callout_reset(&d->bd_callout, d->bd_rtout, 2004 bpf_timed_out, d); 2005 d->bd_state = BPF_WAITING; 2006 } 2007 } 2008 } 2009 BPFD_UNLOCK(d); 2010 return (revents); 2011 } 2012 2013 /* 2014 * Support for kevent() system call. Register EVFILT_READ filters and 2015 * reject all others. 2016 */ 2017 int 2018 bpfkqfilter(struct cdev *dev, struct knote *kn) 2019 { 2020 struct bpf_d *d; 2021 2022 if (devfs_get_cdevpriv((void **)&d) != 0 || 2023 kn->kn_filter != EVFILT_READ) 2024 return (1); 2025 2026 /* 2027 * Refresh PID associated with this descriptor. 2028 */ 2029 BPFD_LOCK(d); 2030 BPF_PID_REFRESH_CUR(d); 2031 kn->kn_fop = &bpfread_filtops; 2032 kn->kn_hook = d; 2033 knlist_add(&d->bd_sel.si_note, kn, 1); 2034 BPFD_UNLOCK(d); 2035 2036 return (0); 2037 } 2038 2039 static void 2040 filt_bpfdetach(struct knote *kn) 2041 { 2042 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2043 2044 knlist_remove(&d->bd_sel.si_note, kn, 0); 2045 } 2046 2047 static int 2048 filt_bpfread(struct knote *kn, long hint) 2049 { 2050 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2051 int ready; 2052 2053 BPFD_LOCK_ASSERT(d); 2054 ready = bpf_ready(d); 2055 if (ready) { 2056 kn->kn_data = d->bd_slen; 2057 /* 2058 * Ignore the hold buffer if it is being copied to user space. 2059 */ 2060 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2061 kn->kn_data += d->bd_hlen; 2062 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2063 callout_reset(&d->bd_callout, d->bd_rtout, 2064 bpf_timed_out, d); 2065 d->bd_state = BPF_WAITING; 2066 } 2067 2068 return (ready); 2069 } 2070 2071 #define BPF_TSTAMP_NONE 0 2072 #define BPF_TSTAMP_FAST 1 2073 #define BPF_TSTAMP_NORMAL 2 2074 #define BPF_TSTAMP_EXTERN 3 2075 2076 static int 2077 bpf_ts_quality(int tstype) 2078 { 2079 2080 if (tstype == BPF_T_NONE) 2081 return (BPF_TSTAMP_NONE); 2082 if ((tstype & BPF_T_FAST) != 0) 2083 return (BPF_TSTAMP_FAST); 2084 2085 return (BPF_TSTAMP_NORMAL); 2086 } 2087 2088 static int 2089 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2090 { 2091 struct m_tag *tag; 2092 int quality; 2093 2094 quality = bpf_ts_quality(tstype); 2095 if (quality == BPF_TSTAMP_NONE) 2096 return (quality); 2097 2098 if (m != NULL) { 2099 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2100 if (tag != NULL) { 2101 *bt = *(struct bintime *)(tag + 1); 2102 return (BPF_TSTAMP_EXTERN); 2103 } 2104 } 2105 if (quality == BPF_TSTAMP_NORMAL) 2106 binuptime(bt); 2107 else 2108 getbinuptime(bt); 2109 2110 return (quality); 2111 } 2112 2113 /* 2114 * Incoming linkage from device drivers. Process the packet pkt, of length 2115 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2116 * by each process' filter, and if accepted, stashed into the corresponding 2117 * buffer. 2118 */ 2119 void 2120 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2121 { 2122 struct bintime bt; 2123 struct bpf_d *d; 2124 #ifdef BPF_JITTER 2125 bpf_jit_filter *bf; 2126 #endif 2127 u_int slen; 2128 int gottime; 2129 2130 gottime = BPF_TSTAMP_NONE; 2131 2132 BPFIF_RLOCK(bp); 2133 2134 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2135 /* 2136 * We are not using any locks for d here because: 2137 * 1) any filter change is protected by interface 2138 * write lock 2139 * 2) destroying/detaching d is protected by interface 2140 * write lock, too 2141 */ 2142 2143 /* XXX: Do not protect counter for the sake of performance. */ 2144 ++d->bd_rcount; 2145 /* 2146 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no 2147 * way for the caller to indiciate to us whether this packet 2148 * is inbound or outbound. In the bpf_mtap() routines, we use 2149 * the interface pointers on the mbuf to figure it out. 2150 */ 2151 #ifdef BPF_JITTER 2152 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2153 if (bf != NULL) 2154 slen = (*(bf->func))(pkt, pktlen, pktlen); 2155 else 2156 #endif 2157 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2158 if (slen != 0) { 2159 /* 2160 * Filter matches. Let's to acquire write lock. 2161 */ 2162 BPFD_LOCK(d); 2163 2164 d->bd_fcount++; 2165 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2166 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL); 2167 #ifdef MAC 2168 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2169 #endif 2170 catchpacket(d, pkt, pktlen, slen, 2171 bpf_append_bytes, &bt); 2172 BPFD_UNLOCK(d); 2173 } 2174 } 2175 BPFIF_RUNLOCK(bp); 2176 } 2177 2178 #define BPF_CHECK_DIRECTION(d, r, i) \ 2179 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2180 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2181 2182 /* 2183 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2184 * Locking model is explained in bpf_tap(). 2185 */ 2186 void 2187 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2188 { 2189 struct bintime bt; 2190 struct bpf_d *d; 2191 #ifdef BPF_JITTER 2192 bpf_jit_filter *bf; 2193 #endif 2194 u_int pktlen, slen; 2195 int gottime; 2196 2197 /* Skip outgoing duplicate packets. */ 2198 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2199 m->m_flags &= ~M_PROMISC; 2200 return; 2201 } 2202 2203 pktlen = m_length(m, NULL); 2204 gottime = BPF_TSTAMP_NONE; 2205 2206 BPFIF_RLOCK(bp); 2207 2208 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2209 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2210 continue; 2211 ++d->bd_rcount; 2212 #ifdef BPF_JITTER 2213 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2214 /* XXX We cannot handle multiple mbufs. */ 2215 if (bf != NULL && m->m_next == NULL) 2216 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); 2217 else 2218 #endif 2219 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2220 if (slen != 0) { 2221 BPFD_LOCK(d); 2222 2223 d->bd_fcount++; 2224 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2225 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2226 #ifdef MAC 2227 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2228 #endif 2229 catchpacket(d, (u_char *)m, pktlen, slen, 2230 bpf_append_mbuf, &bt); 2231 BPFD_UNLOCK(d); 2232 } 2233 } 2234 BPFIF_RUNLOCK(bp); 2235 } 2236 2237 /* 2238 * Incoming linkage from device drivers, when packet is in 2239 * an mbuf chain and to be prepended by a contiguous header. 2240 */ 2241 void 2242 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2243 { 2244 struct bintime bt; 2245 struct mbuf mb; 2246 struct bpf_d *d; 2247 u_int pktlen, slen; 2248 int gottime; 2249 2250 /* Skip outgoing duplicate packets. */ 2251 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2252 m->m_flags &= ~M_PROMISC; 2253 return; 2254 } 2255 2256 pktlen = m_length(m, NULL); 2257 /* 2258 * Craft on-stack mbuf suitable for passing to bpf_filter. 2259 * Note that we cut corners here; we only setup what's 2260 * absolutely needed--this mbuf should never go anywhere else. 2261 */ 2262 mb.m_next = m; 2263 mb.m_data = data; 2264 mb.m_len = dlen; 2265 pktlen += dlen; 2266 2267 gottime = BPF_TSTAMP_NONE; 2268 2269 BPFIF_RLOCK(bp); 2270 2271 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2272 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2273 continue; 2274 ++d->bd_rcount; 2275 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2276 if (slen != 0) { 2277 BPFD_LOCK(d); 2278 2279 d->bd_fcount++; 2280 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2281 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2282 #ifdef MAC 2283 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2284 #endif 2285 catchpacket(d, (u_char *)&mb, pktlen, slen, 2286 bpf_append_mbuf, &bt); 2287 BPFD_UNLOCK(d); 2288 } 2289 } 2290 BPFIF_RUNLOCK(bp); 2291 } 2292 2293 #undef BPF_CHECK_DIRECTION 2294 2295 #undef BPF_TSTAMP_NONE 2296 #undef BPF_TSTAMP_FAST 2297 #undef BPF_TSTAMP_NORMAL 2298 #undef BPF_TSTAMP_EXTERN 2299 2300 static int 2301 bpf_hdrlen(struct bpf_d *d) 2302 { 2303 int hdrlen; 2304 2305 hdrlen = d->bd_bif->bif_hdrlen; 2306 #ifndef BURN_BRIDGES 2307 if (d->bd_tstamp == BPF_T_NONE || 2308 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2309 #ifdef COMPAT_FREEBSD32 2310 if (d->bd_compat32) 2311 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2312 else 2313 #endif 2314 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2315 else 2316 #endif 2317 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2318 #ifdef COMPAT_FREEBSD32 2319 if (d->bd_compat32) 2320 hdrlen = BPF_WORDALIGN32(hdrlen); 2321 else 2322 #endif 2323 hdrlen = BPF_WORDALIGN(hdrlen); 2324 2325 return (hdrlen - d->bd_bif->bif_hdrlen); 2326 } 2327 2328 static void 2329 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2330 { 2331 struct bintime bt2, boottimebin; 2332 struct timeval tsm; 2333 struct timespec tsn; 2334 2335 if ((tstype & BPF_T_MONOTONIC) == 0) { 2336 bt2 = *bt; 2337 getboottimebin(&boottimebin); 2338 bintime_add(&bt2, &boottimebin); 2339 bt = &bt2; 2340 } 2341 switch (BPF_T_FORMAT(tstype)) { 2342 case BPF_T_MICROTIME: 2343 bintime2timeval(bt, &tsm); 2344 ts->bt_sec = tsm.tv_sec; 2345 ts->bt_frac = tsm.tv_usec; 2346 break; 2347 case BPF_T_NANOTIME: 2348 bintime2timespec(bt, &tsn); 2349 ts->bt_sec = tsn.tv_sec; 2350 ts->bt_frac = tsn.tv_nsec; 2351 break; 2352 case BPF_T_BINTIME: 2353 ts->bt_sec = bt->sec; 2354 ts->bt_frac = bt->frac; 2355 break; 2356 } 2357 } 2358 2359 /* 2360 * Move the packet data from interface memory (pkt) into the 2361 * store buffer. "cpfn" is the routine called to do the actual data 2362 * transfer. bcopy is passed in to copy contiguous chunks, while 2363 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2364 * pkt is really an mbuf. 2365 */ 2366 static void 2367 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2368 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2369 struct bintime *bt) 2370 { 2371 struct bpf_xhdr hdr; 2372 #ifndef BURN_BRIDGES 2373 struct bpf_hdr hdr_old; 2374 #ifdef COMPAT_FREEBSD32 2375 struct bpf_hdr32 hdr32_old; 2376 #endif 2377 #endif 2378 int caplen, curlen, hdrlen, totlen; 2379 int do_wakeup = 0; 2380 int do_timestamp; 2381 int tstype; 2382 2383 BPFD_LOCK_ASSERT(d); 2384 2385 /* 2386 * Detect whether user space has released a buffer back to us, and if 2387 * so, move it from being a hold buffer to a free buffer. This may 2388 * not be the best place to do it (for example, we might only want to 2389 * run this check if we need the space), but for now it's a reliable 2390 * spot to do it. 2391 */ 2392 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2393 d->bd_fbuf = d->bd_hbuf; 2394 d->bd_hbuf = NULL; 2395 d->bd_hlen = 0; 2396 bpf_buf_reclaimed(d); 2397 } 2398 2399 /* 2400 * Figure out how many bytes to move. If the packet is 2401 * greater or equal to the snapshot length, transfer that 2402 * much. Otherwise, transfer the whole packet (unless 2403 * we hit the buffer size limit). 2404 */ 2405 hdrlen = bpf_hdrlen(d); 2406 totlen = hdrlen + min(snaplen, pktlen); 2407 if (totlen > d->bd_bufsize) 2408 totlen = d->bd_bufsize; 2409 2410 /* 2411 * Round up the end of the previous packet to the next longword. 2412 * 2413 * Drop the packet if there's no room and no hope of room 2414 * If the packet would overflow the storage buffer or the storage 2415 * buffer is considered immutable by the buffer model, try to rotate 2416 * the buffer and wakeup pending processes. 2417 */ 2418 #ifdef COMPAT_FREEBSD32 2419 if (d->bd_compat32) 2420 curlen = BPF_WORDALIGN32(d->bd_slen); 2421 else 2422 #endif 2423 curlen = BPF_WORDALIGN(d->bd_slen); 2424 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2425 if (d->bd_fbuf == NULL) { 2426 /* 2427 * There's no room in the store buffer, and no 2428 * prospect of room, so drop the packet. Notify the 2429 * buffer model. 2430 */ 2431 bpf_buffull(d); 2432 ++d->bd_dcount; 2433 return; 2434 } 2435 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2436 ROTATE_BUFFERS(d); 2437 do_wakeup = 1; 2438 curlen = 0; 2439 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2440 /* 2441 * Immediate mode is set, or the read timeout has already 2442 * expired during a select call. A packet arrived, so the 2443 * reader should be woken up. 2444 */ 2445 do_wakeup = 1; 2446 caplen = totlen - hdrlen; 2447 tstype = d->bd_tstamp; 2448 do_timestamp = tstype != BPF_T_NONE; 2449 #ifndef BURN_BRIDGES 2450 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2451 struct bpf_ts ts; 2452 if (do_timestamp) 2453 bpf_bintime2ts(bt, &ts, tstype); 2454 #ifdef COMPAT_FREEBSD32 2455 if (d->bd_compat32) { 2456 bzero(&hdr32_old, sizeof(hdr32_old)); 2457 if (do_timestamp) { 2458 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2459 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2460 } 2461 hdr32_old.bh_datalen = pktlen; 2462 hdr32_old.bh_hdrlen = hdrlen; 2463 hdr32_old.bh_caplen = caplen; 2464 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2465 sizeof(hdr32_old)); 2466 goto copy; 2467 } 2468 #endif 2469 bzero(&hdr_old, sizeof(hdr_old)); 2470 if (do_timestamp) { 2471 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2472 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2473 } 2474 hdr_old.bh_datalen = pktlen; 2475 hdr_old.bh_hdrlen = hdrlen; 2476 hdr_old.bh_caplen = caplen; 2477 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2478 sizeof(hdr_old)); 2479 goto copy; 2480 } 2481 #endif 2482 2483 /* 2484 * Append the bpf header. Note we append the actual header size, but 2485 * move forward the length of the header plus padding. 2486 */ 2487 bzero(&hdr, sizeof(hdr)); 2488 if (do_timestamp) 2489 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2490 hdr.bh_datalen = pktlen; 2491 hdr.bh_hdrlen = hdrlen; 2492 hdr.bh_caplen = caplen; 2493 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2494 2495 /* 2496 * Copy the packet data into the store buffer and update its length. 2497 */ 2498 #ifndef BURN_BRIDGES 2499 copy: 2500 #endif 2501 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2502 d->bd_slen = curlen + totlen; 2503 2504 if (do_wakeup) 2505 bpf_wakeup(d); 2506 } 2507 2508 /* 2509 * Free buffers currently in use by a descriptor. 2510 * Called on close. 2511 */ 2512 static void 2513 bpf_freed(struct bpf_d *d) 2514 { 2515 2516 /* 2517 * We don't need to lock out interrupts since this descriptor has 2518 * been detached from its interface and it yet hasn't been marked 2519 * free. 2520 */ 2521 bpf_free(d); 2522 if (d->bd_rfilter != NULL) { 2523 free((caddr_t)d->bd_rfilter, M_BPF); 2524 #ifdef BPF_JITTER 2525 if (d->bd_bfilter != NULL) 2526 bpf_destroy_jit_filter(d->bd_bfilter); 2527 #endif 2528 } 2529 if (d->bd_wfilter != NULL) 2530 free((caddr_t)d->bd_wfilter, M_BPF); 2531 mtx_destroy(&d->bd_lock); 2532 } 2533 2534 /* 2535 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2536 * fixed size of the link header (variable length headers not yet supported). 2537 */ 2538 void 2539 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2540 { 2541 2542 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2543 } 2544 2545 /* 2546 * Attach an interface to bpf. ifp is a pointer to the structure 2547 * defining the interface to be attached, dlt is the link layer type, 2548 * and hdrlen is the fixed size of the link header (variable length 2549 * headers are not yet supporrted). 2550 */ 2551 void 2552 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2553 { 2554 struct bpf_if *bp; 2555 2556 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 2557 if (bp == NULL) 2558 panic("bpfattach"); 2559 2560 LIST_INIT(&bp->bif_dlist); 2561 LIST_INIT(&bp->bif_wlist); 2562 bp->bif_ifp = ifp; 2563 bp->bif_dlt = dlt; 2564 rw_init(&bp->bif_lock, "bpf interface lock"); 2565 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 2566 *driverp = bp; 2567 2568 BPF_LOCK(); 2569 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2570 BPF_UNLOCK(); 2571 2572 bp->bif_hdrlen = hdrlen; 2573 2574 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2575 if_printf(ifp, "bpf attached\n"); 2576 } 2577 2578 #ifdef VIMAGE 2579 /* 2580 * When moving interfaces between vnet instances we need a way to 2581 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2582 * after the vmove. We unfortunately have no device driver infrastructure 2583 * to query the interface for these values after creation/attach, thus 2584 * add this as a workaround. 2585 */ 2586 int 2587 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2588 { 2589 2590 if (bp == NULL) 2591 return (ENXIO); 2592 if (bif_dlt == NULL && bif_hdrlen == NULL) 2593 return (0); 2594 2595 if (bif_dlt != NULL) 2596 *bif_dlt = bp->bif_dlt; 2597 if (bif_hdrlen != NULL) 2598 *bif_hdrlen = bp->bif_hdrlen; 2599 2600 return (0); 2601 } 2602 #endif 2603 2604 /* 2605 * Detach bpf from an interface. This involves detaching each descriptor 2606 * associated with the interface. Notify each descriptor as it's detached 2607 * so that any sleepers wake up and get ENXIO. 2608 */ 2609 void 2610 bpfdetach(struct ifnet *ifp) 2611 { 2612 struct bpf_if *bp, *bp_temp; 2613 struct bpf_d *d; 2614 int ndetached; 2615 2616 ndetached = 0; 2617 2618 BPF_LOCK(); 2619 /* Find all bpf_if struct's which reference ifp and detach them. */ 2620 LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2621 if (ifp != bp->bif_ifp) 2622 continue; 2623 2624 LIST_REMOVE(bp, bif_next); 2625 /* Add to to-be-freed list */ 2626 LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next); 2627 2628 ndetached++; 2629 /* 2630 * Delay freeing bp till interface is detached 2631 * and all routes through this interface are removed. 2632 * Mark bp as detached to restrict new consumers. 2633 */ 2634 BPFIF_WLOCK(bp); 2635 bp->bif_flags |= BPFIF_FLAG_DYING; 2636 BPFIF_WUNLOCK(bp); 2637 2638 CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p", 2639 __func__, bp->bif_dlt, bp, ifp); 2640 2641 /* Free common descriptors */ 2642 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 2643 bpf_detachd_locked(d); 2644 BPFD_LOCK(d); 2645 bpf_wakeup(d); 2646 BPFD_UNLOCK(d); 2647 } 2648 2649 /* Free writer-only descriptors */ 2650 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) { 2651 bpf_detachd_locked(d); 2652 BPFD_LOCK(d); 2653 bpf_wakeup(d); 2654 BPFD_UNLOCK(d); 2655 } 2656 } 2657 BPF_UNLOCK(); 2658 2659 #ifdef INVARIANTS 2660 if (ndetached == 0) 2661 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 2662 #endif 2663 } 2664 2665 /* 2666 * Interface departure handler. 2667 * Note departure event does not guarantee interface is going down. 2668 * Interface renaming is currently done via departure/arrival event set. 2669 * 2670 * Departure handled is called after all routes pointing to 2671 * given interface are removed and interface is in down state 2672 * restricting any packets to be sent/received. We assume it is now safe 2673 * to free data allocated by BPF. 2674 */ 2675 static void 2676 bpf_ifdetach(void *arg __unused, struct ifnet *ifp) 2677 { 2678 struct bpf_if *bp, *bp_temp; 2679 int nmatched = 0; 2680 2681 /* Ignore ifnet renaming. */ 2682 if (ifp->if_flags & IFF_RENAMING) 2683 return; 2684 2685 BPF_LOCK(); 2686 /* 2687 * Find matching entries in free list. 2688 * Nothing should be found if bpfdetach() was not called. 2689 */ 2690 LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) { 2691 if (ifp != bp->bif_ifp) 2692 continue; 2693 2694 CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p", 2695 __func__, bp, ifp); 2696 2697 LIST_REMOVE(bp, bif_next); 2698 2699 rw_destroy(&bp->bif_lock); 2700 free(bp, M_BPF); 2701 2702 nmatched++; 2703 } 2704 BPF_UNLOCK(); 2705 2706 /* 2707 * Note that we cannot zero other pointers to 2708 * custom DLTs possibly used by given interface. 2709 */ 2710 if (nmatched != 0) 2711 ifp->if_bpf = NULL; 2712 } 2713 2714 /* 2715 * Get a list of available data link type of the interface. 2716 */ 2717 static int 2718 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2719 { 2720 struct ifnet *ifp; 2721 struct bpf_if *bp; 2722 u_int *lst; 2723 int error, n, n1; 2724 2725 BPF_LOCK_ASSERT(); 2726 2727 ifp = d->bd_bif->bif_ifp; 2728 again: 2729 n1 = 0; 2730 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2731 if (bp->bif_ifp == ifp) 2732 n1++; 2733 } 2734 if (bfl->bfl_list == NULL) { 2735 bfl->bfl_len = n1; 2736 return (0); 2737 } 2738 if (n1 > bfl->bfl_len) 2739 return (ENOMEM); 2740 BPF_UNLOCK(); 2741 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2742 n = 0; 2743 BPF_LOCK(); 2744 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2745 if (bp->bif_ifp != ifp) 2746 continue; 2747 if (n >= n1) { 2748 free(lst, M_TEMP); 2749 goto again; 2750 } 2751 lst[n] = bp->bif_dlt; 2752 n++; 2753 } 2754 BPF_UNLOCK(); 2755 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2756 free(lst, M_TEMP); 2757 BPF_LOCK(); 2758 bfl->bfl_len = n; 2759 return (error); 2760 } 2761 2762 /* 2763 * Set the data link type of a BPF instance. 2764 */ 2765 static int 2766 bpf_setdlt(struct bpf_d *d, u_int dlt) 2767 { 2768 int error, opromisc; 2769 struct ifnet *ifp; 2770 struct bpf_if *bp; 2771 2772 BPF_LOCK_ASSERT(); 2773 2774 if (d->bd_bif->bif_dlt == dlt) 2775 return (0); 2776 ifp = d->bd_bif->bif_ifp; 2777 2778 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2779 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2780 break; 2781 } 2782 2783 if (bp != NULL) { 2784 opromisc = d->bd_promisc; 2785 bpf_attachd(d, bp); 2786 BPFD_LOCK(d); 2787 reset_d(d); 2788 BPFD_UNLOCK(d); 2789 if (opromisc) { 2790 error = ifpromisc(bp->bif_ifp, 1); 2791 if (error) 2792 if_printf(bp->bif_ifp, 2793 "bpf_setdlt: ifpromisc failed (%d)\n", 2794 error); 2795 else 2796 d->bd_promisc = 1; 2797 } 2798 } 2799 return (bp == NULL ? EINVAL : 0); 2800 } 2801 2802 static void 2803 bpf_drvinit(void *unused) 2804 { 2805 struct cdev *dev; 2806 2807 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2808 LIST_INIT(&bpf_iflist); 2809 LIST_INIT(&bpf_freelist); 2810 2811 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2812 /* For compatibility */ 2813 make_dev_alias(dev, "bpf0"); 2814 2815 /* Register interface departure handler */ 2816 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER( 2817 ifnet_departure_event, bpf_ifdetach, NULL, 2818 EVENTHANDLER_PRI_ANY); 2819 } 2820 2821 /* 2822 * Zero out the various packet counters associated with all of the bpf 2823 * descriptors. At some point, we will probably want to get a bit more 2824 * granular and allow the user to specify descriptors to be zeroed. 2825 */ 2826 static void 2827 bpf_zero_counters(void) 2828 { 2829 struct bpf_if *bp; 2830 struct bpf_d *bd; 2831 2832 BPF_LOCK(); 2833 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2834 BPFIF_RLOCK(bp); 2835 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2836 BPFD_LOCK(bd); 2837 bd->bd_rcount = 0; 2838 bd->bd_dcount = 0; 2839 bd->bd_fcount = 0; 2840 bd->bd_wcount = 0; 2841 bd->bd_wfcount = 0; 2842 bd->bd_zcopy = 0; 2843 BPFD_UNLOCK(bd); 2844 } 2845 BPFIF_RUNLOCK(bp); 2846 } 2847 BPF_UNLOCK(); 2848 } 2849 2850 /* 2851 * Fill filter statistics 2852 */ 2853 static void 2854 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2855 { 2856 2857 bzero(d, sizeof(*d)); 2858 BPFD_LOCK_ASSERT(bd); 2859 d->bd_structsize = sizeof(*d); 2860 /* XXX: reading should be protected by global lock */ 2861 d->bd_immediate = bd->bd_immediate; 2862 d->bd_promisc = bd->bd_promisc; 2863 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2864 d->bd_direction = bd->bd_direction; 2865 d->bd_feedback = bd->bd_feedback; 2866 d->bd_async = bd->bd_async; 2867 d->bd_rcount = bd->bd_rcount; 2868 d->bd_dcount = bd->bd_dcount; 2869 d->bd_fcount = bd->bd_fcount; 2870 d->bd_sig = bd->bd_sig; 2871 d->bd_slen = bd->bd_slen; 2872 d->bd_hlen = bd->bd_hlen; 2873 d->bd_bufsize = bd->bd_bufsize; 2874 d->bd_pid = bd->bd_pid; 2875 strlcpy(d->bd_ifname, 2876 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2877 d->bd_locked = bd->bd_locked; 2878 d->bd_wcount = bd->bd_wcount; 2879 d->bd_wdcount = bd->bd_wdcount; 2880 d->bd_wfcount = bd->bd_wfcount; 2881 d->bd_zcopy = bd->bd_zcopy; 2882 d->bd_bufmode = bd->bd_bufmode; 2883 } 2884 2885 /* 2886 * Handle `netstat -B' stats request 2887 */ 2888 static int 2889 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2890 { 2891 static const struct xbpf_d zerostats; 2892 struct xbpf_d *xbdbuf, *xbd, tempstats; 2893 int index, error; 2894 struct bpf_if *bp; 2895 struct bpf_d *bd; 2896 2897 /* 2898 * XXX This is not technically correct. It is possible for non 2899 * privileged users to open bpf devices. It would make sense 2900 * if the users who opened the devices were able to retrieve 2901 * the statistics for them, too. 2902 */ 2903 error = priv_check(req->td, PRIV_NET_BPF); 2904 if (error) 2905 return (error); 2906 /* 2907 * Check to see if the user is requesting that the counters be 2908 * zeroed out. Explicitly check that the supplied data is zeroed, 2909 * as we aren't allowing the user to set the counters currently. 2910 */ 2911 if (req->newptr != NULL) { 2912 if (req->newlen != sizeof(tempstats)) 2913 return (EINVAL); 2914 memset(&tempstats, 0, sizeof(tempstats)); 2915 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2916 if (error) 2917 return (error); 2918 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2919 return (EINVAL); 2920 bpf_zero_counters(); 2921 return (0); 2922 } 2923 if (req->oldptr == NULL) 2924 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2925 if (bpf_bpfd_cnt == 0) 2926 return (SYSCTL_OUT(req, 0, 0)); 2927 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2928 BPF_LOCK(); 2929 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2930 BPF_UNLOCK(); 2931 free(xbdbuf, M_BPF); 2932 return (ENOMEM); 2933 } 2934 index = 0; 2935 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2936 BPFIF_RLOCK(bp); 2937 /* Send writers-only first */ 2938 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2939 xbd = &xbdbuf[index++]; 2940 BPFD_LOCK(bd); 2941 bpfstats_fill_xbpf(xbd, bd); 2942 BPFD_UNLOCK(bd); 2943 } 2944 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2945 xbd = &xbdbuf[index++]; 2946 BPFD_LOCK(bd); 2947 bpfstats_fill_xbpf(xbd, bd); 2948 BPFD_UNLOCK(bd); 2949 } 2950 BPFIF_RUNLOCK(bp); 2951 } 2952 BPF_UNLOCK(); 2953 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2954 free(xbdbuf, M_BPF); 2955 return (error); 2956 } 2957 2958 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2959 2960 #else /* !DEV_BPF && !NETGRAPH_BPF */ 2961 /* 2962 * NOP stubs to allow bpf-using drivers to load and function. 2963 * 2964 * A 'better' implementation would allow the core bpf functionality 2965 * to be loaded at runtime. 2966 */ 2967 static struct bpf_if bp_null; 2968 2969 void 2970 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2971 { 2972 } 2973 2974 void 2975 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2976 { 2977 } 2978 2979 void 2980 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2981 { 2982 } 2983 2984 void 2985 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2986 { 2987 2988 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2989 } 2990 2991 void 2992 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2993 { 2994 2995 *driverp = &bp_null; 2996 } 2997 2998 void 2999 bpfdetach(struct ifnet *ifp) 3000 { 3001 } 3002 3003 u_int 3004 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3005 { 3006 return -1; /* "no filter" behaviour */ 3007 } 3008 3009 int 3010 bpf_validate(const struct bpf_insn *f, int len) 3011 { 3012 return 0; /* false */ 3013 } 3014 3015 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3016 3017 #ifdef DDB 3018 static void 3019 bpf_show_bpf_if(struct bpf_if *bpf_if) 3020 { 3021 3022 if (bpf_if == NULL) 3023 return; 3024 db_printf("%p:\n", bpf_if); 3025 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3026 /* bif_ext.bif_next */ 3027 /* bif_ext.bif_dlist */ 3028 BPF_DB_PRINTF("%#x", bif_dlt); 3029 BPF_DB_PRINTF("%u", bif_hdrlen); 3030 BPF_DB_PRINTF("%p", bif_ifp); 3031 /* bif_lock */ 3032 /* bif_wlist */ 3033 BPF_DB_PRINTF("%#x", bif_flags); 3034 } 3035 3036 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3037 { 3038 3039 if (!have_addr) { 3040 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3041 return; 3042 } 3043 3044 bpf_show_bpf_if((struct bpf_if *)addr); 3045 } 3046 #endif 3047