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