1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from the Stanford/CMU enet packet filter, 8 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 9 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 10 * Berkeley Laboratory. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_bpf.h" 43 #include "opt_compat.h" 44 #include "opt_ddb.h" 45 #include "opt_netgraph.h" 46 47 #include <sys/types.h> 48 #include <sys/param.h> 49 #include <sys/lock.h> 50 #include <sys/rwlock.h> 51 #include <sys/systm.h> 52 #include <sys/conf.h> 53 #include <sys/fcntl.h> 54 #include <sys/jail.h> 55 #include <sys/malloc.h> 56 #include <sys/mbuf.h> 57 #include <sys/time.h> 58 #include <sys/priv.h> 59 #include <sys/proc.h> 60 #include <sys/signalvar.h> 61 #include <sys/filio.h> 62 #include <sys/sockio.h> 63 #include <sys/ttycom.h> 64 #include <sys/uio.h> 65 #include <sys/sysent.h> 66 67 #include <sys/event.h> 68 #include <sys/file.h> 69 #include <sys/poll.h> 70 #include <sys/proc.h> 71 72 #include <sys/socket.h> 73 74 #ifdef DDB 75 #include <ddb/ddb.h> 76 #endif 77 78 #include <net/if.h> 79 #include <net/if_var.h> 80 #include <net/if_dl.h> 81 #include <net/bpf.h> 82 #include <net/bpf_buffer.h> 83 #ifdef BPF_JITTER 84 #include <net/bpf_jitter.h> 85 #endif 86 #include <net/bpf_zerocopy.h> 87 #include <net/bpfdesc.h> 88 #include <net/route.h> 89 #include <net/vnet.h> 90 91 #include <netinet/in.h> 92 #include <netinet/if_ether.h> 93 #include <sys/kernel.h> 94 #include <sys/sysctl.h> 95 96 #include <net80211/ieee80211_freebsd.h> 97 98 #include <security/mac/mac_framework.h> 99 100 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 101 102 struct bpf_if { 103 #define bif_next bif_ext.bif_next 104 #define bif_dlist bif_ext.bif_dlist 105 struct bpf_if_ext bif_ext; /* public members */ 106 u_int bif_dlt; /* link layer type */ 107 u_int bif_hdrlen; /* length of link header */ 108 struct ifnet *bif_ifp; /* corresponding interface */ 109 struct rwlock bif_lock; /* interface lock */ 110 LIST_HEAD(, bpf_d) bif_wlist; /* writer-only list */ 111 int bif_flags; /* Interface flags */ 112 struct bpf_if **bif_bpf; /* Pointer to pointer to us */ 113 }; 114 115 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); 116 117 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 118 119 #define PRINET 26 /* interruptible */ 120 121 #define SIZEOF_BPF_HDR(type) \ 122 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 123 124 #ifdef COMPAT_FREEBSD32 125 #include <sys/mount.h> 126 #include <compat/freebsd32/freebsd32.h> 127 #define BPF_ALIGNMENT32 sizeof(int32_t) 128 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) 129 130 #ifndef BURN_BRIDGES 131 /* 132 * 32-bit version of structure prepended to each packet. We use this header 133 * instead of the standard one for 32-bit streams. We mark the a stream as 134 * 32-bit the first time we see a 32-bit compat ioctl request. 135 */ 136 struct bpf_hdr32 { 137 struct timeval32 bh_tstamp; /* time stamp */ 138 uint32_t bh_caplen; /* length of captured portion */ 139 uint32_t bh_datalen; /* original length of packet */ 140 uint16_t bh_hdrlen; /* length of bpf header (this struct 141 plus alignment padding) */ 142 }; 143 #endif 144 145 struct bpf_program32 { 146 u_int bf_len; 147 uint32_t bf_insns; 148 }; 149 150 struct bpf_dltlist32 { 151 u_int bfl_len; 152 u_int bfl_list; 153 }; 154 155 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 156 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 157 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 158 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 159 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 160 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 161 #endif 162 163 /* 164 * bpf_iflist is a list of BPF interface structures, each corresponding to a 165 * specific DLT. The same network interface might have several BPF interface 166 * structures registered by different layers in the stack (i.e., 802.11 167 * frames, ethernet frames, etc). 168 */ 169 static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist; 170 static struct mtx bpf_mtx; /* bpf global lock */ 171 static int bpf_bpfd_cnt; 172 173 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 174 static void bpf_detachd(struct bpf_d *); 175 static void bpf_detachd_locked(struct bpf_d *); 176 static void bpf_freed(struct bpf_d *); 177 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 178 struct sockaddr *, int *, struct bpf_d *); 179 static int bpf_setif(struct bpf_d *, struct ifreq *); 180 static void bpf_timed_out(void *); 181 static __inline void 182 bpf_wakeup(struct bpf_d *); 183 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 184 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 185 struct bintime *); 186 static void reset_d(struct bpf_d *); 187 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 188 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 189 static int bpf_setdlt(struct bpf_d *, u_int); 190 static void filt_bpfdetach(struct knote *); 191 static int filt_bpfread(struct knote *, long); 192 static void bpf_drvinit(void *); 193 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 194 195 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 196 int bpf_maxinsns = BPF_MAXINSNS; 197 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 198 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 199 static int bpf_zerocopy_enable = 0; 200 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 201 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 202 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 203 bpf_stats_sysctl, "bpf statistics portal"); 204 205 static VNET_DEFINE(int, bpf_optimize_writers) = 0; 206 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 207 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RW, 208 &VNET_NAME(bpf_optimize_writers), 0, 209 "Do not send packets until BPF program is set"); 210 211 static d_open_t bpfopen; 212 static d_read_t bpfread; 213 static d_write_t bpfwrite; 214 static d_ioctl_t bpfioctl; 215 static d_poll_t bpfpoll; 216 static d_kqfilter_t bpfkqfilter; 217 218 static struct cdevsw bpf_cdevsw = { 219 .d_version = D_VERSION, 220 .d_open = bpfopen, 221 .d_read = bpfread, 222 .d_write = bpfwrite, 223 .d_ioctl = bpfioctl, 224 .d_poll = bpfpoll, 225 .d_name = "bpf", 226 .d_kqfilter = bpfkqfilter, 227 }; 228 229 static struct filterops bpfread_filtops = { 230 .f_isfd = 1, 231 .f_detach = filt_bpfdetach, 232 .f_event = filt_bpfread, 233 }; 234 235 eventhandler_tag bpf_ifdetach_cookie = NULL; 236 237 /* 238 * LOCKING MODEL USED BY BPF: 239 * Locks: 240 * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal, 241 * some global counters and every bpf_if reference. 242 * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters. 243 * 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields 244 * used by bpf_mtap code. 245 * 246 * Lock order: 247 * 248 * Global lock, interface lock, descriptor lock 249 * 250 * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2] 251 * working model. In many places (like bpf_detachd) we start with BPF descriptor 252 * (and we need to at least rlock it to get reliable interface pointer). This 253 * gives us potential LOR. As a result, we use global lock to protect from bpf_if 254 * change in every such place. 255 * 256 * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and 257 * 3) descriptor main wlock. 258 * Reading bd_bif can be protected by any of these locks, typically global lock. 259 * 260 * Changing read/write BPF filter is protected by the same three locks, 261 * the same applies for reading. 262 * 263 * Sleeping in global lock is not allowed due to bpfdetach() using it. 264 */ 265 266 /* 267 * Wrapper functions for various buffering methods. If the set of buffer 268 * modes expands, we will probably want to introduce a switch data structure 269 * similar to protosw, et. 270 */ 271 static void 272 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 273 u_int len) 274 { 275 276 BPFD_LOCK_ASSERT(d); 277 278 switch (d->bd_bufmode) { 279 case BPF_BUFMODE_BUFFER: 280 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 281 282 case BPF_BUFMODE_ZBUF: 283 counter_u64_add(d->bd_zcopy, 1); 284 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 285 286 default: 287 panic("bpf_buf_append_bytes"); 288 } 289 } 290 291 static void 292 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 293 u_int len) 294 { 295 296 BPFD_LOCK_ASSERT(d); 297 298 switch (d->bd_bufmode) { 299 case BPF_BUFMODE_BUFFER: 300 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 301 302 case BPF_BUFMODE_ZBUF: 303 counter_u64_add(d->bd_zcopy, 1); 304 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 305 306 default: 307 panic("bpf_buf_append_mbuf"); 308 } 309 } 310 311 /* 312 * This function gets called when the free buffer is re-assigned. 313 */ 314 static void 315 bpf_buf_reclaimed(struct bpf_d *d) 316 { 317 318 BPFD_LOCK_ASSERT(d); 319 320 switch (d->bd_bufmode) { 321 case BPF_BUFMODE_BUFFER: 322 return; 323 324 case BPF_BUFMODE_ZBUF: 325 bpf_zerocopy_buf_reclaimed(d); 326 return; 327 328 default: 329 panic("bpf_buf_reclaimed"); 330 } 331 } 332 333 /* 334 * If the buffer mechanism has a way to decide that a held buffer can be made 335 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 336 * returned if the buffer can be discarded, (0) is returned if it cannot. 337 */ 338 static int 339 bpf_canfreebuf(struct bpf_d *d) 340 { 341 342 BPFD_LOCK_ASSERT(d); 343 344 switch (d->bd_bufmode) { 345 case BPF_BUFMODE_ZBUF: 346 return (bpf_zerocopy_canfreebuf(d)); 347 } 348 return (0); 349 } 350 351 /* 352 * Allow the buffer model to indicate that the current store buffer is 353 * immutable, regardless of the appearance of space. Return (1) if the 354 * buffer is writable, and (0) if not. 355 */ 356 static int 357 bpf_canwritebuf(struct bpf_d *d) 358 { 359 BPFD_LOCK_ASSERT(d); 360 361 switch (d->bd_bufmode) { 362 case BPF_BUFMODE_ZBUF: 363 return (bpf_zerocopy_canwritebuf(d)); 364 } 365 return (1); 366 } 367 368 /* 369 * Notify buffer model that an attempt to write to the store buffer has 370 * resulted in a dropped packet, in which case the buffer may be considered 371 * full. 372 */ 373 static void 374 bpf_buffull(struct bpf_d *d) 375 { 376 377 BPFD_LOCK_ASSERT(d); 378 379 switch (d->bd_bufmode) { 380 case BPF_BUFMODE_ZBUF: 381 bpf_zerocopy_buffull(d); 382 break; 383 } 384 } 385 386 /* 387 * Notify the buffer model that a buffer has moved into the hold position. 388 */ 389 void 390 bpf_bufheld(struct bpf_d *d) 391 { 392 393 BPFD_LOCK_ASSERT(d); 394 395 switch (d->bd_bufmode) { 396 case BPF_BUFMODE_ZBUF: 397 bpf_zerocopy_bufheld(d); 398 break; 399 } 400 } 401 402 static void 403 bpf_free(struct bpf_d *d) 404 { 405 406 switch (d->bd_bufmode) { 407 case BPF_BUFMODE_BUFFER: 408 return (bpf_buffer_free(d)); 409 410 case BPF_BUFMODE_ZBUF: 411 return (bpf_zerocopy_free(d)); 412 413 default: 414 panic("bpf_buf_free"); 415 } 416 } 417 418 static int 419 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 420 { 421 422 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 423 return (EOPNOTSUPP); 424 return (bpf_buffer_uiomove(d, buf, len, uio)); 425 } 426 427 static int 428 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 429 { 430 431 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 432 return (EOPNOTSUPP); 433 return (bpf_buffer_ioctl_sblen(d, i)); 434 } 435 436 static int 437 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 438 { 439 440 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 441 return (EOPNOTSUPP); 442 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 443 } 444 445 static int 446 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 447 { 448 449 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 450 return (EOPNOTSUPP); 451 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 452 } 453 454 static int 455 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 456 { 457 458 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 459 return (EOPNOTSUPP); 460 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 461 } 462 463 /* 464 * General BPF functions. 465 */ 466 static int 467 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 468 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) 469 { 470 const struct ieee80211_bpf_params *p; 471 struct ether_header *eh; 472 struct mbuf *m; 473 int error; 474 int len; 475 int hlen; 476 int slen; 477 478 /* 479 * Build a sockaddr based on the data link layer type. 480 * We do this at this level because the ethernet header 481 * is copied directly into the data field of the sockaddr. 482 * In the case of SLIP, there is no header and the packet 483 * is forwarded as is. 484 * Also, we are careful to leave room at the front of the mbuf 485 * for the link level header. 486 */ 487 switch (linktype) { 488 489 case DLT_SLIP: 490 sockp->sa_family = AF_INET; 491 hlen = 0; 492 break; 493 494 case DLT_EN10MB: 495 sockp->sa_family = AF_UNSPEC; 496 /* XXX Would MAXLINKHDR be better? */ 497 hlen = ETHER_HDR_LEN; 498 break; 499 500 case DLT_FDDI: 501 sockp->sa_family = AF_IMPLINK; 502 hlen = 0; 503 break; 504 505 case DLT_RAW: 506 sockp->sa_family = AF_UNSPEC; 507 hlen = 0; 508 break; 509 510 case DLT_NULL: 511 /* 512 * null interface types require a 4 byte pseudo header which 513 * corresponds to the address family of the packet. 514 */ 515 sockp->sa_family = AF_UNSPEC; 516 hlen = 4; 517 break; 518 519 case DLT_ATM_RFC1483: 520 /* 521 * en atm driver requires 4-byte atm pseudo header. 522 * though it isn't standard, vpi:vci needs to be 523 * specified anyway. 524 */ 525 sockp->sa_family = AF_UNSPEC; 526 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 527 break; 528 529 case DLT_PPP: 530 sockp->sa_family = AF_UNSPEC; 531 hlen = 4; /* This should match PPP_HDRLEN */ 532 break; 533 534 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 535 sockp->sa_family = AF_IEEE80211; 536 hlen = 0; 537 break; 538 539 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 540 sockp->sa_family = AF_IEEE80211; 541 sockp->sa_len = 12; /* XXX != 0 */ 542 hlen = sizeof(struct ieee80211_bpf_params); 543 break; 544 545 default: 546 return (EIO); 547 } 548 549 len = uio->uio_resid; 550 if (len < hlen || len - hlen > ifp->if_mtu) 551 return (EMSGSIZE); 552 553 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR); 554 if (m == NULL) 555 return (EIO); 556 m->m_pkthdr.len = m->m_len = len; 557 *mp = m; 558 559 error = uiomove(mtod(m, u_char *), len, uio); 560 if (error) 561 goto bad; 562 563 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 564 if (slen == 0) { 565 error = EPERM; 566 goto bad; 567 } 568 569 /* Check for multicast destination */ 570 switch (linktype) { 571 case DLT_EN10MB: 572 eh = mtod(m, struct ether_header *); 573 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 574 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 575 ETHER_ADDR_LEN) == 0) 576 m->m_flags |= M_BCAST; 577 else 578 m->m_flags |= M_MCAST; 579 } 580 if (d->bd_hdrcmplt == 0) { 581 memcpy(eh->ether_shost, IF_LLADDR(ifp), 582 sizeof(eh->ether_shost)); 583 } 584 break; 585 } 586 587 /* 588 * Make room for link header, and copy it to sockaddr 589 */ 590 if (hlen != 0) { 591 if (sockp->sa_family == AF_IEEE80211) { 592 /* 593 * Collect true length from the parameter header 594 * NB: sockp is known to be zero'd so if we do a 595 * short copy unspecified parameters will be 596 * zero. 597 * NB: packet may not be aligned after stripping 598 * bpf params 599 * XXX check ibp_vers 600 */ 601 p = mtod(m, const struct ieee80211_bpf_params *); 602 hlen = p->ibp_len; 603 if (hlen > sizeof(sockp->sa_data)) { 604 error = EINVAL; 605 goto bad; 606 } 607 } 608 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 609 } 610 *hdrlen = hlen; 611 612 return (0); 613 bad: 614 m_freem(m); 615 return (error); 616 } 617 618 /* 619 * Attach file to the bpf interface, i.e. make d listen on bp. 620 */ 621 static void 622 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 623 { 624 int op_w; 625 626 BPF_LOCK_ASSERT(); 627 628 /* 629 * Save sysctl value to protect from sysctl change 630 * between reads 631 */ 632 op_w = V_bpf_optimize_writers || d->bd_writer; 633 634 if (d->bd_bif != NULL) 635 bpf_detachd_locked(d); 636 /* 637 * Point d at bp, and add d to the interface's list. 638 * Since there are many applications using BPF for 639 * sending raw packets only (dhcpd, cdpd are good examples) 640 * we can delay adding d to the list of active listeners until 641 * some filter is configured. 642 */ 643 644 BPFIF_WLOCK(bp); 645 BPFD_LOCK(d); 646 647 d->bd_bif = bp; 648 649 if (op_w != 0) { 650 /* Add to writers-only list */ 651 LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 652 /* 653 * We decrement bd_writer on every filter set operation. 654 * First BIOCSETF is done by pcap_open_live() to set up 655 * snap length. After that appliation usually sets its own filter 656 */ 657 d->bd_writer = 2; 658 } else 659 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 660 661 BPFD_UNLOCK(d); 662 BPFIF_WUNLOCK(bp); 663 664 bpf_bpfd_cnt++; 665 666 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 667 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 668 669 if (op_w == 0) 670 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 671 } 672 673 /* 674 * Check if we need to upgrade our descriptor @d from write-only mode. 675 */ 676 static int 677 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen) 678 { 679 int is_snap, need_upgrade; 680 681 /* 682 * Check if we've already upgraded or new filter is empty. 683 */ 684 if (d->bd_writer == 0 || fcode == NULL) 685 return (0); 686 687 need_upgrade = 0; 688 689 /* 690 * Check if cmd looks like snaplen setting from 691 * pcap_bpf.c:pcap_open_live(). 692 * Note we're not checking .k value here: 693 * while pcap_open_live() definitely sets to non-zero value, 694 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 695 * do not consider upgrading immediately 696 */ 697 if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K)) 698 is_snap = 1; 699 else 700 is_snap = 0; 701 702 if (is_snap == 0) { 703 /* 704 * We're setting first filter and it doesn't look like 705 * setting snaplen. We're probably using bpf directly. 706 * Upgrade immediately. 707 */ 708 need_upgrade = 1; 709 } else { 710 /* 711 * Do not require upgrade by first BIOCSETF 712 * (used to set snaplen) by pcap_open_live(). 713 */ 714 715 if (--d->bd_writer == 0) { 716 /* 717 * First snaplen filter has already 718 * been set. This is probably catch-all 719 * filter 720 */ 721 need_upgrade = 1; 722 } 723 } 724 725 CTR5(KTR_NET, 726 "%s: filter function set by pid %d, " 727 "bd_writer counter %d, snap %d upgrade %d", 728 __func__, d->bd_pid, d->bd_writer, 729 is_snap, need_upgrade); 730 731 return (need_upgrade); 732 } 733 734 /* 735 * Add d to the list of active bp filters. 736 * Requires bpf_attachd() to be called before. 737 */ 738 static void 739 bpf_upgraded(struct bpf_d *d) 740 { 741 struct bpf_if *bp; 742 743 BPF_LOCK_ASSERT(); 744 745 bp = d->bd_bif; 746 747 /* 748 * Filter can be set several times without specifying interface. 749 * Mark d as reader and exit. 750 */ 751 if (bp == NULL) { 752 BPFD_LOCK(d); 753 d->bd_writer = 0; 754 BPFD_UNLOCK(d); 755 return; 756 } 757 758 BPFIF_WLOCK(bp); 759 BPFD_LOCK(d); 760 761 /* Remove from writers-only list */ 762 LIST_REMOVE(d, bd_next); 763 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 764 /* Mark d as reader */ 765 d->bd_writer = 0; 766 767 BPFD_UNLOCK(d); 768 BPFIF_WUNLOCK(bp); 769 770 CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid); 771 772 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 773 } 774 775 /* 776 * Detach a file from its interface. 777 */ 778 static void 779 bpf_detachd(struct bpf_d *d) 780 { 781 BPF_LOCK(); 782 bpf_detachd_locked(d); 783 BPF_UNLOCK(); 784 } 785 786 static void 787 bpf_detachd_locked(struct bpf_d *d) 788 { 789 int error; 790 struct bpf_if *bp; 791 struct ifnet *ifp; 792 793 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 794 795 BPF_LOCK_ASSERT(); 796 797 /* Check if descriptor is attached */ 798 if ((bp = d->bd_bif) == NULL) 799 return; 800 801 BPFIF_WLOCK(bp); 802 BPFD_LOCK(d); 803 804 /* Save bd_writer value */ 805 error = d->bd_writer; 806 807 /* 808 * Remove d from the interface's descriptor list. 809 */ 810 LIST_REMOVE(d, bd_next); 811 812 ifp = bp->bif_ifp; 813 d->bd_bif = NULL; 814 BPFD_UNLOCK(d); 815 BPFIF_WUNLOCK(bp); 816 817 bpf_bpfd_cnt--; 818 819 /* Call event handler iff d is attached */ 820 if (error == 0) 821 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 822 823 /* 824 * Check if this descriptor had requested promiscuous mode. 825 * If so, turn it off. 826 */ 827 if (d->bd_promisc) { 828 d->bd_promisc = 0; 829 CURVNET_SET(ifp->if_vnet); 830 error = ifpromisc(ifp, 0); 831 CURVNET_RESTORE(); 832 if (error != 0 && error != ENXIO) { 833 /* 834 * ENXIO can happen if a pccard is unplugged 835 * Something is really wrong if we were able to put 836 * the driver into promiscuous mode, but can't 837 * take it out. 838 */ 839 if_printf(bp->bif_ifp, 840 "bpf_detach: ifpromisc failed (%d)\n", error); 841 } 842 } 843 } 844 845 /* 846 * Close the descriptor by detaching it from its interface, 847 * deallocating its buffers, and marking it free. 848 */ 849 static void 850 bpf_dtor(void *data) 851 { 852 struct bpf_d *d = data; 853 854 BPFD_LOCK(d); 855 if (d->bd_state == BPF_WAITING) 856 callout_stop(&d->bd_callout); 857 d->bd_state = BPF_IDLE; 858 BPFD_UNLOCK(d); 859 funsetown(&d->bd_sigio); 860 bpf_detachd(d); 861 #ifdef MAC 862 mac_bpfdesc_destroy(d); 863 #endif /* MAC */ 864 seldrain(&d->bd_sel); 865 knlist_destroy(&d->bd_sel.si_note); 866 callout_drain(&d->bd_callout); 867 bpf_freed(d); 868 free(d, M_BPF); 869 } 870 871 /* 872 * Open ethernet device. Returns ENXIO for illegal minor device number, 873 * EBUSY if file is open by another process. 874 */ 875 /* ARGSUSED */ 876 static int 877 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 878 { 879 struct bpf_d *d; 880 int error; 881 882 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 883 error = devfs_set_cdevpriv(d, bpf_dtor); 884 if (error != 0) { 885 free(d, M_BPF); 886 return (error); 887 } 888 889 /* Setup counters */ 890 d->bd_rcount = counter_u64_alloc(M_WAITOK); 891 d->bd_dcount = counter_u64_alloc(M_WAITOK); 892 d->bd_fcount = counter_u64_alloc(M_WAITOK); 893 d->bd_wcount = counter_u64_alloc(M_WAITOK); 894 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 895 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 896 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 897 898 /* 899 * For historical reasons, perform a one-time initialization call to 900 * the buffer routines, even though we're not yet committed to a 901 * particular buffer method. 902 */ 903 bpf_buffer_init(d); 904 if ((flags & FREAD) == 0) 905 d->bd_writer = 2; 906 d->bd_hbuf_in_use = 0; 907 d->bd_bufmode = BPF_BUFMODE_BUFFER; 908 d->bd_sig = SIGIO; 909 d->bd_direction = BPF_D_INOUT; 910 BPF_PID_REFRESH(d, td); 911 #ifdef MAC 912 mac_bpfdesc_init(d); 913 mac_bpfdesc_create(td->td_ucred, d); 914 #endif 915 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 916 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 917 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 918 919 return (0); 920 } 921 922 /* 923 * bpfread - read next chunk of packets from buffers 924 */ 925 static int 926 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 927 { 928 struct bpf_d *d; 929 int error; 930 int non_block; 931 int timed_out; 932 933 error = devfs_get_cdevpriv((void **)&d); 934 if (error != 0) 935 return (error); 936 937 /* 938 * Restrict application to use a buffer the same size as 939 * as kernel buffers. 940 */ 941 if (uio->uio_resid != d->bd_bufsize) 942 return (EINVAL); 943 944 non_block = ((ioflag & O_NONBLOCK) != 0); 945 946 BPFD_LOCK(d); 947 BPF_PID_REFRESH_CUR(d); 948 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 949 BPFD_UNLOCK(d); 950 return (EOPNOTSUPP); 951 } 952 if (d->bd_state == BPF_WAITING) 953 callout_stop(&d->bd_callout); 954 timed_out = (d->bd_state == BPF_TIMED_OUT); 955 d->bd_state = BPF_IDLE; 956 while (d->bd_hbuf_in_use) { 957 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 958 PRINET|PCATCH, "bd_hbuf", 0); 959 if (error != 0) { 960 BPFD_UNLOCK(d); 961 return (error); 962 } 963 } 964 /* 965 * If the hold buffer is empty, then do a timed sleep, which 966 * ends when the timeout expires or when enough packets 967 * have arrived to fill the store buffer. 968 */ 969 while (d->bd_hbuf == NULL) { 970 if (d->bd_slen != 0) { 971 /* 972 * A packet(s) either arrived since the previous 973 * read or arrived while we were asleep. 974 */ 975 if (d->bd_immediate || non_block || timed_out) { 976 /* 977 * Rotate the buffers and return what's here 978 * if we are in immediate mode, non-blocking 979 * flag is set, or this descriptor timed out. 980 */ 981 ROTATE_BUFFERS(d); 982 break; 983 } 984 } 985 986 /* 987 * No data is available, check to see if the bpf device 988 * is still pointed at a real interface. If not, return 989 * ENXIO so that the userland process knows to rebind 990 * it before using it again. 991 */ 992 if (d->bd_bif == NULL) { 993 BPFD_UNLOCK(d); 994 return (ENXIO); 995 } 996 997 if (non_block) { 998 BPFD_UNLOCK(d); 999 return (EWOULDBLOCK); 1000 } 1001 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 1002 "bpf", d->bd_rtout); 1003 if (error == EINTR || error == ERESTART) { 1004 BPFD_UNLOCK(d); 1005 return (error); 1006 } 1007 if (error == EWOULDBLOCK) { 1008 /* 1009 * On a timeout, return what's in the buffer, 1010 * which may be nothing. If there is something 1011 * in the store buffer, we can rotate the buffers. 1012 */ 1013 if (d->bd_hbuf) 1014 /* 1015 * We filled up the buffer in between 1016 * getting the timeout and arriving 1017 * here, so we don't need to rotate. 1018 */ 1019 break; 1020 1021 if (d->bd_slen == 0) { 1022 BPFD_UNLOCK(d); 1023 return (0); 1024 } 1025 ROTATE_BUFFERS(d); 1026 break; 1027 } 1028 } 1029 /* 1030 * At this point, we know we have something in the hold slot. 1031 */ 1032 d->bd_hbuf_in_use = 1; 1033 BPFD_UNLOCK(d); 1034 1035 /* 1036 * Move data from hold buffer into user space. 1037 * We know the entire buffer is transferred since 1038 * we checked above that the read buffer is bpf_bufsize bytes. 1039 * 1040 * We do not have to worry about simultaneous reads because 1041 * we waited for sole access to the hold buffer above. 1042 */ 1043 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1044 1045 BPFD_LOCK(d); 1046 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1047 d->bd_fbuf = d->bd_hbuf; 1048 d->bd_hbuf = NULL; 1049 d->bd_hlen = 0; 1050 bpf_buf_reclaimed(d); 1051 d->bd_hbuf_in_use = 0; 1052 wakeup(&d->bd_hbuf_in_use); 1053 BPFD_UNLOCK(d); 1054 1055 return (error); 1056 } 1057 1058 /* 1059 * If there are processes sleeping on this descriptor, wake them up. 1060 */ 1061 static __inline void 1062 bpf_wakeup(struct bpf_d *d) 1063 { 1064 1065 BPFD_LOCK_ASSERT(d); 1066 if (d->bd_state == BPF_WAITING) { 1067 callout_stop(&d->bd_callout); 1068 d->bd_state = BPF_IDLE; 1069 } 1070 wakeup(d); 1071 if (d->bd_async && d->bd_sig && d->bd_sigio) 1072 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1073 1074 selwakeuppri(&d->bd_sel, PRINET); 1075 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1076 } 1077 1078 static void 1079 bpf_timed_out(void *arg) 1080 { 1081 struct bpf_d *d = (struct bpf_d *)arg; 1082 1083 BPFD_LOCK_ASSERT(d); 1084 1085 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) 1086 return; 1087 if (d->bd_state == BPF_WAITING) { 1088 d->bd_state = BPF_TIMED_OUT; 1089 if (d->bd_slen != 0) 1090 bpf_wakeup(d); 1091 } 1092 } 1093 1094 static int 1095 bpf_ready(struct bpf_d *d) 1096 { 1097 1098 BPFD_LOCK_ASSERT(d); 1099 1100 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1101 return (1); 1102 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1103 d->bd_slen != 0) 1104 return (1); 1105 return (0); 1106 } 1107 1108 static int 1109 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1110 { 1111 struct bpf_d *d; 1112 struct ifnet *ifp; 1113 struct mbuf *m, *mc; 1114 struct sockaddr dst; 1115 struct route ro; 1116 int error, hlen; 1117 1118 error = devfs_get_cdevpriv((void **)&d); 1119 if (error != 0) 1120 return (error); 1121 1122 BPF_PID_REFRESH_CUR(d); 1123 counter_u64_add(d->bd_wcount, 1); 1124 /* XXX: locking required */ 1125 if (d->bd_bif == NULL) { 1126 counter_u64_add(d->bd_wdcount, 1); 1127 return (ENXIO); 1128 } 1129 1130 ifp = d->bd_bif->bif_ifp; 1131 1132 if ((ifp->if_flags & IFF_UP) == 0) { 1133 counter_u64_add(d->bd_wdcount, 1); 1134 return (ENETDOWN); 1135 } 1136 1137 if (uio->uio_resid == 0) { 1138 counter_u64_add(d->bd_wdcount, 1); 1139 return (0); 1140 } 1141 1142 bzero(&dst, sizeof(dst)); 1143 m = NULL; 1144 hlen = 0; 1145 /* XXX: bpf_movein() can sleep */ 1146 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 1147 &m, &dst, &hlen, d); 1148 if (error) { 1149 counter_u64_add(d->bd_wdcount, 1); 1150 return (error); 1151 } 1152 counter_u64_add(d->bd_wfcount, 1); 1153 if (d->bd_hdrcmplt) 1154 dst.sa_family = pseudo_AF_HDRCMPLT; 1155 1156 if (d->bd_feedback) { 1157 mc = m_dup(m, M_NOWAIT); 1158 if (mc != NULL) 1159 mc->m_pkthdr.rcvif = ifp; 1160 /* Set M_PROMISC for outgoing packets to be discarded. */ 1161 if (d->bd_direction == BPF_D_INOUT) 1162 m->m_flags |= M_PROMISC; 1163 } else 1164 mc = NULL; 1165 1166 m->m_pkthdr.len -= hlen; 1167 m->m_len -= hlen; 1168 m->m_data += hlen; /* XXX */ 1169 1170 CURVNET_SET(ifp->if_vnet); 1171 #ifdef MAC 1172 BPFD_LOCK(d); 1173 mac_bpfdesc_create_mbuf(d, m); 1174 if (mc != NULL) 1175 mac_bpfdesc_create_mbuf(d, mc); 1176 BPFD_UNLOCK(d); 1177 #endif 1178 1179 bzero(&ro, sizeof(ro)); 1180 if (hlen != 0) { 1181 ro.ro_prepend = (u_char *)&dst.sa_data; 1182 ro.ro_plen = hlen; 1183 ro.ro_flags = RT_HAS_HEADER; 1184 } 1185 1186 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1187 if (error) 1188 counter_u64_add(d->bd_wdcount, 1); 1189 1190 if (mc != NULL) { 1191 if (error == 0) 1192 (*ifp->if_input)(ifp, mc); 1193 else 1194 m_freem(mc); 1195 } 1196 CURVNET_RESTORE(); 1197 1198 return (error); 1199 } 1200 1201 /* 1202 * Reset a descriptor by flushing its packet buffer and clearing the receive 1203 * and drop counts. This is doable for kernel-only buffers, but with 1204 * zero-copy buffers, we can't write to (or rotate) buffers that are 1205 * currently owned by userspace. It would be nice if we could encapsulate 1206 * this logic in the buffer code rather than here. 1207 */ 1208 static void 1209 reset_d(struct bpf_d *d) 1210 { 1211 1212 BPFD_LOCK_ASSERT(d); 1213 1214 while (d->bd_hbuf_in_use) 1215 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1216 "bd_hbuf", 0); 1217 if ((d->bd_hbuf != NULL) && 1218 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1219 /* Free the hold buffer. */ 1220 d->bd_fbuf = d->bd_hbuf; 1221 d->bd_hbuf = NULL; 1222 d->bd_hlen = 0; 1223 bpf_buf_reclaimed(d); 1224 } 1225 if (bpf_canwritebuf(d)) 1226 d->bd_slen = 0; 1227 counter_u64_zero(d->bd_rcount); 1228 counter_u64_zero(d->bd_dcount); 1229 counter_u64_zero(d->bd_fcount); 1230 counter_u64_zero(d->bd_wcount); 1231 counter_u64_zero(d->bd_wfcount); 1232 counter_u64_zero(d->bd_wdcount); 1233 counter_u64_zero(d->bd_zcopy); 1234 } 1235 1236 /* 1237 * FIONREAD Check for read packet available. 1238 * BIOCGBLEN Get buffer len [for read()]. 1239 * BIOCSETF Set read filter. 1240 * BIOCSETFNR Set read filter without resetting descriptor. 1241 * BIOCSETWF Set write filter. 1242 * BIOCFLUSH Flush read packet buffer. 1243 * BIOCPROMISC Put interface into promiscuous mode. 1244 * BIOCGDLT Get link layer type. 1245 * BIOCGETIF Get interface name. 1246 * BIOCSETIF Set interface. 1247 * BIOCSRTIMEOUT Set read timeout. 1248 * BIOCGRTIMEOUT Get read timeout. 1249 * BIOCGSTATS Get packet stats. 1250 * BIOCIMMEDIATE Set immediate mode. 1251 * BIOCVERSION Get filter language version. 1252 * BIOCGHDRCMPLT Get "header already complete" flag 1253 * BIOCSHDRCMPLT Set "header already complete" flag 1254 * BIOCGDIRECTION Get packet direction flag 1255 * BIOCSDIRECTION Set packet direction flag 1256 * BIOCGTSTAMP Get time stamp format and resolution. 1257 * BIOCSTSTAMP Set time stamp format and resolution. 1258 * BIOCLOCK Set "locked" flag 1259 * BIOCFEEDBACK Set packet feedback mode. 1260 * BIOCSETZBUF Set current zero-copy buffer locations. 1261 * BIOCGETZMAX Get maximum zero-copy buffer size. 1262 * BIOCROTZBUF Force rotation of zero-copy buffer 1263 * BIOCSETBUFMODE Set buffer mode. 1264 * BIOCGETBUFMODE Get current buffer mode. 1265 */ 1266 /* ARGSUSED */ 1267 static int 1268 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1269 struct thread *td) 1270 { 1271 struct bpf_d *d; 1272 int error; 1273 1274 error = devfs_get_cdevpriv((void **)&d); 1275 if (error != 0) 1276 return (error); 1277 1278 /* 1279 * Refresh PID associated with this descriptor. 1280 */ 1281 BPFD_LOCK(d); 1282 BPF_PID_REFRESH(d, td); 1283 if (d->bd_state == BPF_WAITING) 1284 callout_stop(&d->bd_callout); 1285 d->bd_state = BPF_IDLE; 1286 BPFD_UNLOCK(d); 1287 1288 if (d->bd_locked == 1) { 1289 switch (cmd) { 1290 case BIOCGBLEN: 1291 case BIOCFLUSH: 1292 case BIOCGDLT: 1293 case BIOCGDLTLIST: 1294 #ifdef COMPAT_FREEBSD32 1295 case BIOCGDLTLIST32: 1296 #endif 1297 case BIOCGETIF: 1298 case BIOCGRTIMEOUT: 1299 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1300 case BIOCGRTIMEOUT32: 1301 #endif 1302 case BIOCGSTATS: 1303 case BIOCVERSION: 1304 case BIOCGRSIG: 1305 case BIOCGHDRCMPLT: 1306 case BIOCSTSTAMP: 1307 case BIOCFEEDBACK: 1308 case FIONREAD: 1309 case BIOCLOCK: 1310 case BIOCSRTIMEOUT: 1311 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1312 case BIOCSRTIMEOUT32: 1313 #endif 1314 case BIOCIMMEDIATE: 1315 case TIOCGPGRP: 1316 case BIOCROTZBUF: 1317 break; 1318 default: 1319 return (EPERM); 1320 } 1321 } 1322 #ifdef COMPAT_FREEBSD32 1323 /* 1324 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1325 * that it will get 32-bit packet headers. 1326 */ 1327 switch (cmd) { 1328 case BIOCSETF32: 1329 case BIOCSETFNR32: 1330 case BIOCSETWF32: 1331 case BIOCGDLTLIST32: 1332 case BIOCGRTIMEOUT32: 1333 case BIOCSRTIMEOUT32: 1334 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1335 BPFD_LOCK(d); 1336 d->bd_compat32 = 1; 1337 BPFD_UNLOCK(d); 1338 } 1339 } 1340 #endif 1341 1342 CURVNET_SET(TD_TO_VNET(td)); 1343 switch (cmd) { 1344 1345 default: 1346 error = EINVAL; 1347 break; 1348 1349 /* 1350 * Check for read packet available. 1351 */ 1352 case FIONREAD: 1353 { 1354 int n; 1355 1356 BPFD_LOCK(d); 1357 n = d->bd_slen; 1358 while (d->bd_hbuf_in_use) 1359 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1360 PRINET, "bd_hbuf", 0); 1361 if (d->bd_hbuf) 1362 n += d->bd_hlen; 1363 BPFD_UNLOCK(d); 1364 1365 *(int *)addr = n; 1366 break; 1367 } 1368 1369 /* 1370 * Get buffer len [for read()]. 1371 */ 1372 case BIOCGBLEN: 1373 BPFD_LOCK(d); 1374 *(u_int *)addr = d->bd_bufsize; 1375 BPFD_UNLOCK(d); 1376 break; 1377 1378 /* 1379 * Set buffer length. 1380 */ 1381 case BIOCSBLEN: 1382 error = bpf_ioctl_sblen(d, (u_int *)addr); 1383 break; 1384 1385 /* 1386 * Set link layer read filter. 1387 */ 1388 case BIOCSETF: 1389 case BIOCSETFNR: 1390 case BIOCSETWF: 1391 #ifdef COMPAT_FREEBSD32 1392 case BIOCSETF32: 1393 case BIOCSETFNR32: 1394 case BIOCSETWF32: 1395 #endif 1396 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1397 break; 1398 1399 /* 1400 * Flush read packet buffer. 1401 */ 1402 case BIOCFLUSH: 1403 BPFD_LOCK(d); 1404 reset_d(d); 1405 BPFD_UNLOCK(d); 1406 break; 1407 1408 /* 1409 * Put interface into promiscuous mode. 1410 */ 1411 case BIOCPROMISC: 1412 if (d->bd_bif == NULL) { 1413 /* 1414 * No interface attached yet. 1415 */ 1416 error = EINVAL; 1417 break; 1418 } 1419 if (d->bd_promisc == 0) { 1420 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1421 if (error == 0) 1422 d->bd_promisc = 1; 1423 } 1424 break; 1425 1426 /* 1427 * Get current data link type. 1428 */ 1429 case BIOCGDLT: 1430 BPF_LOCK(); 1431 if (d->bd_bif == NULL) 1432 error = EINVAL; 1433 else 1434 *(u_int *)addr = d->bd_bif->bif_dlt; 1435 BPF_UNLOCK(); 1436 break; 1437 1438 /* 1439 * Get a list of supported data link types. 1440 */ 1441 #ifdef COMPAT_FREEBSD32 1442 case BIOCGDLTLIST32: 1443 { 1444 struct bpf_dltlist32 *list32; 1445 struct bpf_dltlist dltlist; 1446 1447 list32 = (struct bpf_dltlist32 *)addr; 1448 dltlist.bfl_len = list32->bfl_len; 1449 dltlist.bfl_list = PTRIN(list32->bfl_list); 1450 BPF_LOCK(); 1451 if (d->bd_bif == NULL) 1452 error = EINVAL; 1453 else { 1454 error = bpf_getdltlist(d, &dltlist); 1455 if (error == 0) 1456 list32->bfl_len = dltlist.bfl_len; 1457 } 1458 BPF_UNLOCK(); 1459 break; 1460 } 1461 #endif 1462 1463 case BIOCGDLTLIST: 1464 BPF_LOCK(); 1465 if (d->bd_bif == NULL) 1466 error = EINVAL; 1467 else 1468 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1469 BPF_UNLOCK(); 1470 break; 1471 1472 /* 1473 * Set data link type. 1474 */ 1475 case BIOCSDLT: 1476 BPF_LOCK(); 1477 if (d->bd_bif == NULL) 1478 error = EINVAL; 1479 else 1480 error = bpf_setdlt(d, *(u_int *)addr); 1481 BPF_UNLOCK(); 1482 break; 1483 1484 /* 1485 * Get interface name. 1486 */ 1487 case BIOCGETIF: 1488 BPF_LOCK(); 1489 if (d->bd_bif == NULL) 1490 error = EINVAL; 1491 else { 1492 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1493 struct ifreq *const ifr = (struct ifreq *)addr; 1494 1495 strlcpy(ifr->ifr_name, ifp->if_xname, 1496 sizeof(ifr->ifr_name)); 1497 } 1498 BPF_UNLOCK(); 1499 break; 1500 1501 /* 1502 * Set interface. 1503 */ 1504 case BIOCSETIF: 1505 { 1506 int alloc_buf, size; 1507 1508 /* 1509 * Behavior here depends on the buffering model. If 1510 * we're using kernel memory buffers, then we can 1511 * allocate them here. If we're using zero-copy, 1512 * then the user process must have registered buffers 1513 * by the time we get here. 1514 */ 1515 alloc_buf = 0; 1516 BPFD_LOCK(d); 1517 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1518 d->bd_sbuf == NULL) 1519 alloc_buf = 1; 1520 BPFD_UNLOCK(d); 1521 if (alloc_buf) { 1522 size = d->bd_bufsize; 1523 error = bpf_buffer_ioctl_sblen(d, &size); 1524 if (error != 0) 1525 break; 1526 } 1527 BPF_LOCK(); 1528 error = bpf_setif(d, (struct ifreq *)addr); 1529 BPF_UNLOCK(); 1530 break; 1531 } 1532 1533 /* 1534 * Set read timeout. 1535 */ 1536 case BIOCSRTIMEOUT: 1537 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1538 case BIOCSRTIMEOUT32: 1539 #endif 1540 { 1541 struct timeval *tv = (struct timeval *)addr; 1542 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1543 struct timeval32 *tv32; 1544 struct timeval tv64; 1545 1546 if (cmd == BIOCSRTIMEOUT32) { 1547 tv32 = (struct timeval32 *)addr; 1548 tv = &tv64; 1549 tv->tv_sec = tv32->tv_sec; 1550 tv->tv_usec = tv32->tv_usec; 1551 } else 1552 #endif 1553 tv = (struct timeval *)addr; 1554 1555 /* 1556 * Subtract 1 tick from tvtohz() since this isn't 1557 * a one-shot timer. 1558 */ 1559 if ((error = itimerfix(tv)) == 0) 1560 d->bd_rtout = tvtohz(tv) - 1; 1561 break; 1562 } 1563 1564 /* 1565 * Get read timeout. 1566 */ 1567 case BIOCGRTIMEOUT: 1568 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1569 case BIOCGRTIMEOUT32: 1570 #endif 1571 { 1572 struct timeval *tv; 1573 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1574 struct timeval32 *tv32; 1575 struct timeval tv64; 1576 1577 if (cmd == BIOCGRTIMEOUT32) 1578 tv = &tv64; 1579 else 1580 #endif 1581 tv = (struct timeval *)addr; 1582 1583 tv->tv_sec = d->bd_rtout / hz; 1584 tv->tv_usec = (d->bd_rtout % hz) * tick; 1585 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1586 if (cmd == BIOCGRTIMEOUT32) { 1587 tv32 = (struct timeval32 *)addr; 1588 tv32->tv_sec = tv->tv_sec; 1589 tv32->tv_usec = tv->tv_usec; 1590 } 1591 #endif 1592 1593 break; 1594 } 1595 1596 /* 1597 * Get packet stats. 1598 */ 1599 case BIOCGSTATS: 1600 { 1601 struct bpf_stat *bs = (struct bpf_stat *)addr; 1602 1603 /* XXXCSJP overflow */ 1604 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1605 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1606 break; 1607 } 1608 1609 /* 1610 * Set immediate mode. 1611 */ 1612 case BIOCIMMEDIATE: 1613 BPFD_LOCK(d); 1614 d->bd_immediate = *(u_int *)addr; 1615 BPFD_UNLOCK(d); 1616 break; 1617 1618 case BIOCVERSION: 1619 { 1620 struct bpf_version *bv = (struct bpf_version *)addr; 1621 1622 bv->bv_major = BPF_MAJOR_VERSION; 1623 bv->bv_minor = BPF_MINOR_VERSION; 1624 break; 1625 } 1626 1627 /* 1628 * Get "header already complete" flag 1629 */ 1630 case BIOCGHDRCMPLT: 1631 BPFD_LOCK(d); 1632 *(u_int *)addr = d->bd_hdrcmplt; 1633 BPFD_UNLOCK(d); 1634 break; 1635 1636 /* 1637 * Set "header already complete" flag 1638 */ 1639 case BIOCSHDRCMPLT: 1640 BPFD_LOCK(d); 1641 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1642 BPFD_UNLOCK(d); 1643 break; 1644 1645 /* 1646 * Get packet direction flag 1647 */ 1648 case BIOCGDIRECTION: 1649 BPFD_LOCK(d); 1650 *(u_int *)addr = d->bd_direction; 1651 BPFD_UNLOCK(d); 1652 break; 1653 1654 /* 1655 * Set packet direction flag 1656 */ 1657 case BIOCSDIRECTION: 1658 { 1659 u_int direction; 1660 1661 direction = *(u_int *)addr; 1662 switch (direction) { 1663 case BPF_D_IN: 1664 case BPF_D_INOUT: 1665 case BPF_D_OUT: 1666 BPFD_LOCK(d); 1667 d->bd_direction = direction; 1668 BPFD_UNLOCK(d); 1669 break; 1670 default: 1671 error = EINVAL; 1672 } 1673 } 1674 break; 1675 1676 /* 1677 * Get packet timestamp format and resolution. 1678 */ 1679 case BIOCGTSTAMP: 1680 BPFD_LOCK(d); 1681 *(u_int *)addr = d->bd_tstamp; 1682 BPFD_UNLOCK(d); 1683 break; 1684 1685 /* 1686 * Set packet timestamp format and resolution. 1687 */ 1688 case BIOCSTSTAMP: 1689 { 1690 u_int func; 1691 1692 func = *(u_int *)addr; 1693 if (BPF_T_VALID(func)) 1694 d->bd_tstamp = func; 1695 else 1696 error = EINVAL; 1697 } 1698 break; 1699 1700 case BIOCFEEDBACK: 1701 BPFD_LOCK(d); 1702 d->bd_feedback = *(u_int *)addr; 1703 BPFD_UNLOCK(d); 1704 break; 1705 1706 case BIOCLOCK: 1707 BPFD_LOCK(d); 1708 d->bd_locked = 1; 1709 BPFD_UNLOCK(d); 1710 break; 1711 1712 case FIONBIO: /* Non-blocking I/O */ 1713 break; 1714 1715 case FIOASYNC: /* Send signal on receive packets */ 1716 BPFD_LOCK(d); 1717 d->bd_async = *(int *)addr; 1718 BPFD_UNLOCK(d); 1719 break; 1720 1721 case FIOSETOWN: 1722 /* 1723 * XXX: Add some sort of locking here? 1724 * fsetown() can sleep. 1725 */ 1726 error = fsetown(*(int *)addr, &d->bd_sigio); 1727 break; 1728 1729 case FIOGETOWN: 1730 BPFD_LOCK(d); 1731 *(int *)addr = fgetown(&d->bd_sigio); 1732 BPFD_UNLOCK(d); 1733 break; 1734 1735 /* This is deprecated, FIOSETOWN should be used instead. */ 1736 case TIOCSPGRP: 1737 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1738 break; 1739 1740 /* This is deprecated, FIOGETOWN should be used instead. */ 1741 case TIOCGPGRP: 1742 *(int *)addr = -fgetown(&d->bd_sigio); 1743 break; 1744 1745 case BIOCSRSIG: /* Set receive signal */ 1746 { 1747 u_int sig; 1748 1749 sig = *(u_int *)addr; 1750 1751 if (sig >= NSIG) 1752 error = EINVAL; 1753 else { 1754 BPFD_LOCK(d); 1755 d->bd_sig = sig; 1756 BPFD_UNLOCK(d); 1757 } 1758 break; 1759 } 1760 case BIOCGRSIG: 1761 BPFD_LOCK(d); 1762 *(u_int *)addr = d->bd_sig; 1763 BPFD_UNLOCK(d); 1764 break; 1765 1766 case BIOCGETBUFMODE: 1767 BPFD_LOCK(d); 1768 *(u_int *)addr = d->bd_bufmode; 1769 BPFD_UNLOCK(d); 1770 break; 1771 1772 case BIOCSETBUFMODE: 1773 /* 1774 * Allow the buffering mode to be changed as long as we 1775 * haven't yet committed to a particular mode. Our 1776 * definition of commitment, for now, is whether or not a 1777 * buffer has been allocated or an interface attached, since 1778 * that's the point where things get tricky. 1779 */ 1780 switch (*(u_int *)addr) { 1781 case BPF_BUFMODE_BUFFER: 1782 break; 1783 1784 case BPF_BUFMODE_ZBUF: 1785 if (bpf_zerocopy_enable) 1786 break; 1787 /* FALLSTHROUGH */ 1788 1789 default: 1790 CURVNET_RESTORE(); 1791 return (EINVAL); 1792 } 1793 1794 BPFD_LOCK(d); 1795 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1796 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1797 BPFD_UNLOCK(d); 1798 CURVNET_RESTORE(); 1799 return (EBUSY); 1800 } 1801 d->bd_bufmode = *(u_int *)addr; 1802 BPFD_UNLOCK(d); 1803 break; 1804 1805 case BIOCGETZMAX: 1806 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1807 break; 1808 1809 case BIOCSETZBUF: 1810 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1811 break; 1812 1813 case BIOCROTZBUF: 1814 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1815 break; 1816 } 1817 CURVNET_RESTORE(); 1818 return (error); 1819 } 1820 1821 /* 1822 * Set d's packet filter program to fp. If this file already has a filter, 1823 * free it and replace it. Returns EINVAL for bogus requests. 1824 * 1825 * Note we need global lock here to serialize bpf_setf() and bpf_setif() calls 1826 * since reading d->bd_bif can't be protected by d or interface lock due to 1827 * lock order. 1828 * 1829 * Additionally, we have to acquire interface write lock due to bpf_mtap() uses 1830 * interface read lock to read all filers. 1831 * 1832 */ 1833 static int 1834 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1835 { 1836 #ifdef COMPAT_FREEBSD32 1837 struct bpf_program fp_swab; 1838 struct bpf_program32 *fp32; 1839 #endif 1840 struct bpf_insn *fcode, *old; 1841 #ifdef BPF_JITTER 1842 bpf_jit_filter *jfunc, *ofunc; 1843 #endif 1844 size_t size; 1845 u_int flen; 1846 int need_upgrade; 1847 1848 #ifdef COMPAT_FREEBSD32 1849 switch (cmd) { 1850 case BIOCSETF32: 1851 case BIOCSETWF32: 1852 case BIOCSETFNR32: 1853 fp32 = (struct bpf_program32 *)fp; 1854 fp_swab.bf_len = fp32->bf_len; 1855 fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1856 fp = &fp_swab; 1857 switch (cmd) { 1858 case BIOCSETF32: 1859 cmd = BIOCSETF; 1860 break; 1861 case BIOCSETWF32: 1862 cmd = BIOCSETWF; 1863 break; 1864 } 1865 break; 1866 } 1867 #endif 1868 1869 fcode = NULL; 1870 #ifdef BPF_JITTER 1871 jfunc = ofunc = NULL; 1872 #endif 1873 need_upgrade = 0; 1874 1875 /* 1876 * Check new filter validness before acquiring any locks. 1877 * Allocate memory for new filter, if needed. 1878 */ 1879 flen = fp->bf_len; 1880 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1881 return (EINVAL); 1882 size = flen * sizeof(*fp->bf_insns); 1883 if (size > 0) { 1884 /* We're setting up new filter. Copy and check actual data. */ 1885 fcode = malloc(size, M_BPF, M_WAITOK); 1886 if (copyin(fp->bf_insns, fcode, size) != 0 || 1887 !bpf_validate(fcode, flen)) { 1888 free(fcode, M_BPF); 1889 return (EINVAL); 1890 } 1891 #ifdef BPF_JITTER 1892 /* Filter is copied inside fcode and is perfectly valid. */ 1893 jfunc = bpf_jitter(fcode, flen); 1894 #endif 1895 } 1896 1897 BPF_LOCK(); 1898 1899 /* 1900 * Set up new filter. 1901 * Protect filter change by interface lock. 1902 * Additionally, we are protected by global lock here. 1903 */ 1904 if (d->bd_bif != NULL) 1905 BPFIF_WLOCK(d->bd_bif); 1906 BPFD_LOCK(d); 1907 if (cmd == BIOCSETWF) { 1908 old = d->bd_wfilter; 1909 d->bd_wfilter = fcode; 1910 } else { 1911 old = d->bd_rfilter; 1912 d->bd_rfilter = fcode; 1913 #ifdef BPF_JITTER 1914 ofunc = d->bd_bfilter; 1915 d->bd_bfilter = jfunc; 1916 #endif 1917 if (cmd == BIOCSETF) 1918 reset_d(d); 1919 1920 need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen); 1921 } 1922 BPFD_UNLOCK(d); 1923 if (d->bd_bif != NULL) 1924 BPFIF_WUNLOCK(d->bd_bif); 1925 if (old != NULL) 1926 free(old, M_BPF); 1927 #ifdef BPF_JITTER 1928 if (ofunc != NULL) 1929 bpf_destroy_jit_filter(ofunc); 1930 #endif 1931 1932 /* Move d to active readers list. */ 1933 if (need_upgrade != 0) 1934 bpf_upgraded(d); 1935 1936 BPF_UNLOCK(); 1937 return (0); 1938 } 1939 1940 /* 1941 * Detach a file from its current interface (if attached at all) and attach 1942 * to the interface indicated by the name stored in ifr. 1943 * Return an errno or 0. 1944 */ 1945 static int 1946 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1947 { 1948 struct bpf_if *bp; 1949 struct ifnet *theywant; 1950 1951 BPF_LOCK_ASSERT(); 1952 1953 theywant = ifunit(ifr->ifr_name); 1954 if (theywant == NULL || theywant->if_bpf == NULL) 1955 return (ENXIO); 1956 1957 bp = theywant->if_bpf; 1958 1959 /* Check if interface is not being detached from BPF */ 1960 BPFIF_RLOCK(bp); 1961 if (bp->bif_flags & BPFIF_FLAG_DYING) { 1962 BPFIF_RUNLOCK(bp); 1963 return (ENXIO); 1964 } 1965 BPFIF_RUNLOCK(bp); 1966 1967 /* 1968 * At this point, we expect the buffer is already allocated. If not, 1969 * return an error. 1970 */ 1971 switch (d->bd_bufmode) { 1972 case BPF_BUFMODE_BUFFER: 1973 case BPF_BUFMODE_ZBUF: 1974 if (d->bd_sbuf == NULL) 1975 return (EINVAL); 1976 break; 1977 1978 default: 1979 panic("bpf_setif: bufmode %d", d->bd_bufmode); 1980 } 1981 if (bp != d->bd_bif) 1982 bpf_attachd(d, bp); 1983 BPFD_LOCK(d); 1984 reset_d(d); 1985 BPFD_UNLOCK(d); 1986 return (0); 1987 } 1988 1989 /* 1990 * Support for select() and poll() system calls 1991 * 1992 * Return true iff the specific operation will not block indefinitely. 1993 * Otherwise, return false but make a note that a selwakeup() must be done. 1994 */ 1995 static int 1996 bpfpoll(struct cdev *dev, int events, struct thread *td) 1997 { 1998 struct bpf_d *d; 1999 int revents; 2000 2001 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2002 return (events & 2003 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 2004 2005 /* 2006 * Refresh PID associated with this descriptor. 2007 */ 2008 revents = events & (POLLOUT | POLLWRNORM); 2009 BPFD_LOCK(d); 2010 BPF_PID_REFRESH(d, td); 2011 if (events & (POLLIN | POLLRDNORM)) { 2012 if (bpf_ready(d)) 2013 revents |= events & (POLLIN | POLLRDNORM); 2014 else { 2015 selrecord(td, &d->bd_sel); 2016 /* Start the read timeout if necessary. */ 2017 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2018 callout_reset(&d->bd_callout, d->bd_rtout, 2019 bpf_timed_out, d); 2020 d->bd_state = BPF_WAITING; 2021 } 2022 } 2023 } 2024 BPFD_UNLOCK(d); 2025 return (revents); 2026 } 2027 2028 /* 2029 * Support for kevent() system call. Register EVFILT_READ filters and 2030 * reject all others. 2031 */ 2032 int 2033 bpfkqfilter(struct cdev *dev, struct knote *kn) 2034 { 2035 struct bpf_d *d; 2036 2037 if (devfs_get_cdevpriv((void **)&d) != 0 || 2038 kn->kn_filter != EVFILT_READ) 2039 return (1); 2040 2041 /* 2042 * Refresh PID associated with this descriptor. 2043 */ 2044 BPFD_LOCK(d); 2045 BPF_PID_REFRESH_CUR(d); 2046 kn->kn_fop = &bpfread_filtops; 2047 kn->kn_hook = d; 2048 knlist_add(&d->bd_sel.si_note, kn, 1); 2049 BPFD_UNLOCK(d); 2050 2051 return (0); 2052 } 2053 2054 static void 2055 filt_bpfdetach(struct knote *kn) 2056 { 2057 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2058 2059 knlist_remove(&d->bd_sel.si_note, kn, 0); 2060 } 2061 2062 static int 2063 filt_bpfread(struct knote *kn, long hint) 2064 { 2065 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2066 int ready; 2067 2068 BPFD_LOCK_ASSERT(d); 2069 ready = bpf_ready(d); 2070 if (ready) { 2071 kn->kn_data = d->bd_slen; 2072 /* 2073 * Ignore the hold buffer if it is being copied to user space. 2074 */ 2075 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2076 kn->kn_data += d->bd_hlen; 2077 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2078 callout_reset(&d->bd_callout, d->bd_rtout, 2079 bpf_timed_out, d); 2080 d->bd_state = BPF_WAITING; 2081 } 2082 2083 return (ready); 2084 } 2085 2086 #define BPF_TSTAMP_NONE 0 2087 #define BPF_TSTAMP_FAST 1 2088 #define BPF_TSTAMP_NORMAL 2 2089 #define BPF_TSTAMP_EXTERN 3 2090 2091 static int 2092 bpf_ts_quality(int tstype) 2093 { 2094 2095 if (tstype == BPF_T_NONE) 2096 return (BPF_TSTAMP_NONE); 2097 if ((tstype & BPF_T_FAST) != 0) 2098 return (BPF_TSTAMP_FAST); 2099 2100 return (BPF_TSTAMP_NORMAL); 2101 } 2102 2103 static int 2104 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2105 { 2106 struct m_tag *tag; 2107 int quality; 2108 2109 quality = bpf_ts_quality(tstype); 2110 if (quality == BPF_TSTAMP_NONE) 2111 return (quality); 2112 2113 if (m != NULL) { 2114 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2115 if (tag != NULL) { 2116 *bt = *(struct bintime *)(tag + 1); 2117 return (BPF_TSTAMP_EXTERN); 2118 } 2119 } 2120 if (quality == BPF_TSTAMP_NORMAL) 2121 binuptime(bt); 2122 else 2123 getbinuptime(bt); 2124 2125 return (quality); 2126 } 2127 2128 /* 2129 * Incoming linkage from device drivers. Process the packet pkt, of length 2130 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2131 * by each process' filter, and if accepted, stashed into the corresponding 2132 * buffer. 2133 */ 2134 void 2135 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2136 { 2137 struct bintime bt; 2138 struct bpf_d *d; 2139 #ifdef BPF_JITTER 2140 bpf_jit_filter *bf; 2141 #endif 2142 u_int slen; 2143 int gottime; 2144 2145 gottime = BPF_TSTAMP_NONE; 2146 2147 BPFIF_RLOCK(bp); 2148 2149 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2150 /* 2151 * We are not using any locks for d here because: 2152 * 1) any filter change is protected by interface 2153 * write lock 2154 * 2) destroying/detaching d is protected by interface 2155 * write lock, too 2156 */ 2157 2158 counter_u64_add(d->bd_rcount, 1); 2159 /* 2160 * NB: We dont call BPF_CHECK_DIRECTION() here since there is no 2161 * way for the caller to indiciate to us whether this packet 2162 * is inbound or outbound. In the bpf_mtap() routines, we use 2163 * the interface pointers on the mbuf to figure it out. 2164 */ 2165 #ifdef BPF_JITTER 2166 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2167 if (bf != NULL) 2168 slen = (*(bf->func))(pkt, pktlen, pktlen); 2169 else 2170 #endif 2171 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2172 if (slen != 0) { 2173 /* 2174 * Filter matches. Let's to acquire write lock. 2175 */ 2176 BPFD_LOCK(d); 2177 2178 counter_u64_add(d->bd_fcount, 1); 2179 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2180 gottime = bpf_gettime(&bt, d->bd_tstamp, NULL); 2181 #ifdef MAC 2182 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2183 #endif 2184 catchpacket(d, pkt, pktlen, slen, 2185 bpf_append_bytes, &bt); 2186 BPFD_UNLOCK(d); 2187 } 2188 } 2189 BPFIF_RUNLOCK(bp); 2190 } 2191 2192 #define BPF_CHECK_DIRECTION(d, r, i) \ 2193 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2194 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2195 2196 /* 2197 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2198 * Locking model is explained in bpf_tap(). 2199 */ 2200 void 2201 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2202 { 2203 struct bintime bt; 2204 struct bpf_d *d; 2205 #ifdef BPF_JITTER 2206 bpf_jit_filter *bf; 2207 #endif 2208 u_int pktlen, slen; 2209 int gottime; 2210 2211 /* Skip outgoing duplicate packets. */ 2212 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2213 m->m_flags &= ~M_PROMISC; 2214 return; 2215 } 2216 2217 pktlen = m_length(m, NULL); 2218 gottime = BPF_TSTAMP_NONE; 2219 2220 BPFIF_RLOCK(bp); 2221 2222 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2223 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2224 continue; 2225 counter_u64_add(d->bd_rcount, 1); 2226 #ifdef BPF_JITTER 2227 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2228 /* XXX We cannot handle multiple mbufs. */ 2229 if (bf != NULL && m->m_next == NULL) 2230 slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); 2231 else 2232 #endif 2233 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2234 if (slen != 0) { 2235 BPFD_LOCK(d); 2236 2237 counter_u64_add(d->bd_fcount, 1); 2238 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2239 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2240 #ifdef MAC 2241 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2242 #endif 2243 catchpacket(d, (u_char *)m, pktlen, slen, 2244 bpf_append_mbuf, &bt); 2245 BPFD_UNLOCK(d); 2246 } 2247 } 2248 BPFIF_RUNLOCK(bp); 2249 } 2250 2251 /* 2252 * Incoming linkage from device drivers, when packet is in 2253 * an mbuf chain and to be prepended by a contiguous header. 2254 */ 2255 void 2256 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2257 { 2258 struct bintime bt; 2259 struct mbuf mb; 2260 struct bpf_d *d; 2261 u_int pktlen, slen; 2262 int gottime; 2263 2264 /* Skip outgoing duplicate packets. */ 2265 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2266 m->m_flags &= ~M_PROMISC; 2267 return; 2268 } 2269 2270 pktlen = m_length(m, NULL); 2271 /* 2272 * Craft on-stack mbuf suitable for passing to bpf_filter. 2273 * Note that we cut corners here; we only setup what's 2274 * absolutely needed--this mbuf should never go anywhere else. 2275 */ 2276 mb.m_next = m; 2277 mb.m_data = data; 2278 mb.m_len = dlen; 2279 pktlen += dlen; 2280 2281 gottime = BPF_TSTAMP_NONE; 2282 2283 BPFIF_RLOCK(bp); 2284 2285 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2286 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2287 continue; 2288 counter_u64_add(d->bd_rcount, 1); 2289 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2290 if (slen != 0) { 2291 BPFD_LOCK(d); 2292 2293 counter_u64_add(d->bd_fcount, 1); 2294 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2295 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2296 #ifdef MAC 2297 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2298 #endif 2299 catchpacket(d, (u_char *)&mb, pktlen, slen, 2300 bpf_append_mbuf, &bt); 2301 BPFD_UNLOCK(d); 2302 } 2303 } 2304 BPFIF_RUNLOCK(bp); 2305 } 2306 2307 #undef BPF_CHECK_DIRECTION 2308 2309 #undef BPF_TSTAMP_NONE 2310 #undef BPF_TSTAMP_FAST 2311 #undef BPF_TSTAMP_NORMAL 2312 #undef BPF_TSTAMP_EXTERN 2313 2314 static int 2315 bpf_hdrlen(struct bpf_d *d) 2316 { 2317 int hdrlen; 2318 2319 hdrlen = d->bd_bif->bif_hdrlen; 2320 #ifndef BURN_BRIDGES 2321 if (d->bd_tstamp == BPF_T_NONE || 2322 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2323 #ifdef COMPAT_FREEBSD32 2324 if (d->bd_compat32) 2325 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2326 else 2327 #endif 2328 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2329 else 2330 #endif 2331 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2332 #ifdef COMPAT_FREEBSD32 2333 if (d->bd_compat32) 2334 hdrlen = BPF_WORDALIGN32(hdrlen); 2335 else 2336 #endif 2337 hdrlen = BPF_WORDALIGN(hdrlen); 2338 2339 return (hdrlen - d->bd_bif->bif_hdrlen); 2340 } 2341 2342 static void 2343 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2344 { 2345 struct bintime bt2, boottimebin; 2346 struct timeval tsm; 2347 struct timespec tsn; 2348 2349 if ((tstype & BPF_T_MONOTONIC) == 0) { 2350 bt2 = *bt; 2351 getboottimebin(&boottimebin); 2352 bintime_add(&bt2, &boottimebin); 2353 bt = &bt2; 2354 } 2355 switch (BPF_T_FORMAT(tstype)) { 2356 case BPF_T_MICROTIME: 2357 bintime2timeval(bt, &tsm); 2358 ts->bt_sec = tsm.tv_sec; 2359 ts->bt_frac = tsm.tv_usec; 2360 break; 2361 case BPF_T_NANOTIME: 2362 bintime2timespec(bt, &tsn); 2363 ts->bt_sec = tsn.tv_sec; 2364 ts->bt_frac = tsn.tv_nsec; 2365 break; 2366 case BPF_T_BINTIME: 2367 ts->bt_sec = bt->sec; 2368 ts->bt_frac = bt->frac; 2369 break; 2370 } 2371 } 2372 2373 /* 2374 * Move the packet data from interface memory (pkt) into the 2375 * store buffer. "cpfn" is the routine called to do the actual data 2376 * transfer. bcopy is passed in to copy contiguous chunks, while 2377 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2378 * pkt is really an mbuf. 2379 */ 2380 static void 2381 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2382 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2383 struct bintime *bt) 2384 { 2385 struct bpf_xhdr hdr; 2386 #ifndef BURN_BRIDGES 2387 struct bpf_hdr hdr_old; 2388 #ifdef COMPAT_FREEBSD32 2389 struct bpf_hdr32 hdr32_old; 2390 #endif 2391 #endif 2392 int caplen, curlen, hdrlen, totlen; 2393 int do_wakeup = 0; 2394 int do_timestamp; 2395 int tstype; 2396 2397 BPFD_LOCK_ASSERT(d); 2398 2399 /* 2400 * Detect whether user space has released a buffer back to us, and if 2401 * so, move it from being a hold buffer to a free buffer. This may 2402 * not be the best place to do it (for example, we might only want to 2403 * run this check if we need the space), but for now it's a reliable 2404 * spot to do it. 2405 */ 2406 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2407 d->bd_fbuf = d->bd_hbuf; 2408 d->bd_hbuf = NULL; 2409 d->bd_hlen = 0; 2410 bpf_buf_reclaimed(d); 2411 } 2412 2413 /* 2414 * Figure out how many bytes to move. If the packet is 2415 * greater or equal to the snapshot length, transfer that 2416 * much. Otherwise, transfer the whole packet (unless 2417 * we hit the buffer size limit). 2418 */ 2419 hdrlen = bpf_hdrlen(d); 2420 totlen = hdrlen + min(snaplen, pktlen); 2421 if (totlen > d->bd_bufsize) 2422 totlen = d->bd_bufsize; 2423 2424 /* 2425 * Round up the end of the previous packet to the next longword. 2426 * 2427 * Drop the packet if there's no room and no hope of room 2428 * If the packet would overflow the storage buffer or the storage 2429 * buffer is considered immutable by the buffer model, try to rotate 2430 * the buffer and wakeup pending processes. 2431 */ 2432 #ifdef COMPAT_FREEBSD32 2433 if (d->bd_compat32) 2434 curlen = BPF_WORDALIGN32(d->bd_slen); 2435 else 2436 #endif 2437 curlen = BPF_WORDALIGN(d->bd_slen); 2438 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2439 if (d->bd_fbuf == NULL) { 2440 /* 2441 * There's no room in the store buffer, and no 2442 * prospect of room, so drop the packet. Notify the 2443 * buffer model. 2444 */ 2445 bpf_buffull(d); 2446 counter_u64_add(d->bd_dcount, 1); 2447 return; 2448 } 2449 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2450 ROTATE_BUFFERS(d); 2451 do_wakeup = 1; 2452 curlen = 0; 2453 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2454 /* 2455 * Immediate mode is set, or the read timeout has already 2456 * expired during a select call. A packet arrived, so the 2457 * reader should be woken up. 2458 */ 2459 do_wakeup = 1; 2460 caplen = totlen - hdrlen; 2461 tstype = d->bd_tstamp; 2462 do_timestamp = tstype != BPF_T_NONE; 2463 #ifndef BURN_BRIDGES 2464 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2465 struct bpf_ts ts; 2466 if (do_timestamp) 2467 bpf_bintime2ts(bt, &ts, tstype); 2468 #ifdef COMPAT_FREEBSD32 2469 if (d->bd_compat32) { 2470 bzero(&hdr32_old, sizeof(hdr32_old)); 2471 if (do_timestamp) { 2472 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2473 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2474 } 2475 hdr32_old.bh_datalen = pktlen; 2476 hdr32_old.bh_hdrlen = hdrlen; 2477 hdr32_old.bh_caplen = caplen; 2478 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2479 sizeof(hdr32_old)); 2480 goto copy; 2481 } 2482 #endif 2483 bzero(&hdr_old, sizeof(hdr_old)); 2484 if (do_timestamp) { 2485 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2486 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2487 } 2488 hdr_old.bh_datalen = pktlen; 2489 hdr_old.bh_hdrlen = hdrlen; 2490 hdr_old.bh_caplen = caplen; 2491 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2492 sizeof(hdr_old)); 2493 goto copy; 2494 } 2495 #endif 2496 2497 /* 2498 * Append the bpf header. Note we append the actual header size, but 2499 * move forward the length of the header plus padding. 2500 */ 2501 bzero(&hdr, sizeof(hdr)); 2502 if (do_timestamp) 2503 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2504 hdr.bh_datalen = pktlen; 2505 hdr.bh_hdrlen = hdrlen; 2506 hdr.bh_caplen = caplen; 2507 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2508 2509 /* 2510 * Copy the packet data into the store buffer and update its length. 2511 */ 2512 #ifndef BURN_BRIDGES 2513 copy: 2514 #endif 2515 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2516 d->bd_slen = curlen + totlen; 2517 2518 if (do_wakeup) 2519 bpf_wakeup(d); 2520 } 2521 2522 /* 2523 * Free buffers currently in use by a descriptor. 2524 * Called on close. 2525 */ 2526 static void 2527 bpf_freed(struct bpf_d *d) 2528 { 2529 2530 /* 2531 * We don't need to lock out interrupts since this descriptor has 2532 * been detached from its interface and it yet hasn't been marked 2533 * free. 2534 */ 2535 bpf_free(d); 2536 if (d->bd_rfilter != NULL) { 2537 free((caddr_t)d->bd_rfilter, M_BPF); 2538 #ifdef BPF_JITTER 2539 if (d->bd_bfilter != NULL) 2540 bpf_destroy_jit_filter(d->bd_bfilter); 2541 #endif 2542 } 2543 if (d->bd_wfilter != NULL) 2544 free((caddr_t)d->bd_wfilter, M_BPF); 2545 mtx_destroy(&d->bd_lock); 2546 2547 counter_u64_free(d->bd_rcount); 2548 counter_u64_free(d->bd_dcount); 2549 counter_u64_free(d->bd_fcount); 2550 counter_u64_free(d->bd_wcount); 2551 counter_u64_free(d->bd_wfcount); 2552 counter_u64_free(d->bd_wdcount); 2553 counter_u64_free(d->bd_zcopy); 2554 2555 } 2556 2557 /* 2558 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2559 * fixed size of the link header (variable length headers not yet supported). 2560 */ 2561 void 2562 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2563 { 2564 2565 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2566 } 2567 2568 /* 2569 * Attach an interface to bpf. ifp is a pointer to the structure 2570 * defining the interface to be attached, dlt is the link layer type, 2571 * and hdrlen is the fixed size of the link header (variable length 2572 * headers are not yet supporrted). 2573 */ 2574 void 2575 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2576 { 2577 struct bpf_if *bp; 2578 2579 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 2580 if (bp == NULL) 2581 panic("bpfattach"); 2582 2583 LIST_INIT(&bp->bif_dlist); 2584 LIST_INIT(&bp->bif_wlist); 2585 bp->bif_ifp = ifp; 2586 bp->bif_dlt = dlt; 2587 rw_init(&bp->bif_lock, "bpf interface lock"); 2588 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 2589 bp->bif_bpf = driverp; 2590 *driverp = bp; 2591 2592 BPF_LOCK(); 2593 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2594 BPF_UNLOCK(); 2595 2596 bp->bif_hdrlen = hdrlen; 2597 2598 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2599 if_printf(ifp, "bpf attached\n"); 2600 } 2601 2602 #ifdef VIMAGE 2603 /* 2604 * When moving interfaces between vnet instances we need a way to 2605 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2606 * after the vmove. We unfortunately have no device driver infrastructure 2607 * to query the interface for these values after creation/attach, thus 2608 * add this as a workaround. 2609 */ 2610 int 2611 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2612 { 2613 2614 if (bp == NULL) 2615 return (ENXIO); 2616 if (bif_dlt == NULL && bif_hdrlen == NULL) 2617 return (0); 2618 2619 if (bif_dlt != NULL) 2620 *bif_dlt = bp->bif_dlt; 2621 if (bif_hdrlen != NULL) 2622 *bif_hdrlen = bp->bif_hdrlen; 2623 2624 return (0); 2625 } 2626 #endif 2627 2628 /* 2629 * Detach bpf from an interface. This involves detaching each descriptor 2630 * associated with the interface. Notify each descriptor as it's detached 2631 * so that any sleepers wake up and get ENXIO. 2632 */ 2633 void 2634 bpfdetach(struct ifnet *ifp) 2635 { 2636 struct bpf_if *bp, *bp_temp; 2637 struct bpf_d *d; 2638 int ndetached; 2639 2640 ndetached = 0; 2641 2642 BPF_LOCK(); 2643 /* Find all bpf_if struct's which reference ifp and detach them. */ 2644 LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2645 if (ifp != bp->bif_ifp) 2646 continue; 2647 2648 LIST_REMOVE(bp, bif_next); 2649 /* Add to to-be-freed list */ 2650 LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next); 2651 2652 ndetached++; 2653 /* 2654 * Delay freeing bp till interface is detached 2655 * and all routes through this interface are removed. 2656 * Mark bp as detached to restrict new consumers. 2657 */ 2658 BPFIF_WLOCK(bp); 2659 bp->bif_flags |= BPFIF_FLAG_DYING; 2660 *bp->bif_bpf = NULL; 2661 BPFIF_WUNLOCK(bp); 2662 2663 CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p", 2664 __func__, bp->bif_dlt, bp, ifp); 2665 2666 /* Free common descriptors */ 2667 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 2668 bpf_detachd_locked(d); 2669 BPFD_LOCK(d); 2670 bpf_wakeup(d); 2671 BPFD_UNLOCK(d); 2672 } 2673 2674 /* Free writer-only descriptors */ 2675 while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) { 2676 bpf_detachd_locked(d); 2677 BPFD_LOCK(d); 2678 bpf_wakeup(d); 2679 BPFD_UNLOCK(d); 2680 } 2681 } 2682 BPF_UNLOCK(); 2683 2684 #ifdef INVARIANTS 2685 if (ndetached == 0) 2686 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 2687 #endif 2688 } 2689 2690 /* 2691 * Interface departure handler. 2692 * Note departure event does not guarantee interface is going down. 2693 * Interface renaming is currently done via departure/arrival event set. 2694 * 2695 * Departure handled is called after all routes pointing to 2696 * given interface are removed and interface is in down state 2697 * restricting any packets to be sent/received. We assume it is now safe 2698 * to free data allocated by BPF. 2699 */ 2700 static void 2701 bpf_ifdetach(void *arg __unused, struct ifnet *ifp) 2702 { 2703 struct bpf_if *bp, *bp_temp; 2704 int nmatched = 0; 2705 2706 /* Ignore ifnet renaming. */ 2707 if (ifp->if_flags & IFF_RENAMING) 2708 return; 2709 2710 BPF_LOCK(); 2711 /* 2712 * Find matching entries in free list. 2713 * Nothing should be found if bpfdetach() was not called. 2714 */ 2715 LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) { 2716 if (ifp != bp->bif_ifp) 2717 continue; 2718 2719 CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p", 2720 __func__, bp, ifp); 2721 2722 LIST_REMOVE(bp, bif_next); 2723 2724 rw_destroy(&bp->bif_lock); 2725 free(bp, M_BPF); 2726 2727 nmatched++; 2728 } 2729 BPF_UNLOCK(); 2730 } 2731 2732 /* 2733 * Get a list of available data link type of the interface. 2734 */ 2735 static int 2736 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2737 { 2738 struct ifnet *ifp; 2739 struct bpf_if *bp; 2740 u_int *lst; 2741 int error, n, n1; 2742 2743 BPF_LOCK_ASSERT(); 2744 2745 ifp = d->bd_bif->bif_ifp; 2746 again: 2747 n1 = 0; 2748 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2749 if (bp->bif_ifp == ifp) 2750 n1++; 2751 } 2752 if (bfl->bfl_list == NULL) { 2753 bfl->bfl_len = n1; 2754 return (0); 2755 } 2756 if (n1 > bfl->bfl_len) 2757 return (ENOMEM); 2758 BPF_UNLOCK(); 2759 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2760 n = 0; 2761 BPF_LOCK(); 2762 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2763 if (bp->bif_ifp != ifp) 2764 continue; 2765 if (n >= n1) { 2766 free(lst, M_TEMP); 2767 goto again; 2768 } 2769 lst[n] = bp->bif_dlt; 2770 n++; 2771 } 2772 BPF_UNLOCK(); 2773 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2774 free(lst, M_TEMP); 2775 BPF_LOCK(); 2776 bfl->bfl_len = n; 2777 return (error); 2778 } 2779 2780 /* 2781 * Set the data link type of a BPF instance. 2782 */ 2783 static int 2784 bpf_setdlt(struct bpf_d *d, u_int dlt) 2785 { 2786 int error, opromisc; 2787 struct ifnet *ifp; 2788 struct bpf_if *bp; 2789 2790 BPF_LOCK_ASSERT(); 2791 2792 if (d->bd_bif->bif_dlt == dlt) 2793 return (0); 2794 ifp = d->bd_bif->bif_ifp; 2795 2796 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2797 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2798 break; 2799 } 2800 2801 if (bp != NULL) { 2802 opromisc = d->bd_promisc; 2803 bpf_attachd(d, bp); 2804 BPFD_LOCK(d); 2805 reset_d(d); 2806 BPFD_UNLOCK(d); 2807 if (opromisc) { 2808 error = ifpromisc(bp->bif_ifp, 1); 2809 if (error) 2810 if_printf(bp->bif_ifp, 2811 "bpf_setdlt: ifpromisc failed (%d)\n", 2812 error); 2813 else 2814 d->bd_promisc = 1; 2815 } 2816 } 2817 return (bp == NULL ? EINVAL : 0); 2818 } 2819 2820 static void 2821 bpf_drvinit(void *unused) 2822 { 2823 struct cdev *dev; 2824 2825 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 2826 LIST_INIT(&bpf_iflist); 2827 LIST_INIT(&bpf_freelist); 2828 2829 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2830 /* For compatibility */ 2831 make_dev_alias(dev, "bpf0"); 2832 2833 /* Register interface departure handler */ 2834 bpf_ifdetach_cookie = EVENTHANDLER_REGISTER( 2835 ifnet_departure_event, bpf_ifdetach, NULL, 2836 EVENTHANDLER_PRI_ANY); 2837 } 2838 2839 /* 2840 * Zero out the various packet counters associated with all of the bpf 2841 * descriptors. At some point, we will probably want to get a bit more 2842 * granular and allow the user to specify descriptors to be zeroed. 2843 */ 2844 static void 2845 bpf_zero_counters(void) 2846 { 2847 struct bpf_if *bp; 2848 struct bpf_d *bd; 2849 2850 BPF_LOCK(); 2851 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2852 BPFIF_RLOCK(bp); 2853 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2854 BPFD_LOCK(bd); 2855 counter_u64_zero(bd->bd_rcount); 2856 counter_u64_zero(bd->bd_dcount); 2857 counter_u64_zero(bd->bd_fcount); 2858 counter_u64_zero(bd->bd_wcount); 2859 counter_u64_zero(bd->bd_wfcount); 2860 counter_u64_zero(bd->bd_zcopy); 2861 BPFD_UNLOCK(bd); 2862 } 2863 BPFIF_RUNLOCK(bp); 2864 } 2865 BPF_UNLOCK(); 2866 } 2867 2868 /* 2869 * Fill filter statistics 2870 */ 2871 static void 2872 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2873 { 2874 2875 bzero(d, sizeof(*d)); 2876 BPFD_LOCK_ASSERT(bd); 2877 d->bd_structsize = sizeof(*d); 2878 /* XXX: reading should be protected by global lock */ 2879 d->bd_immediate = bd->bd_immediate; 2880 d->bd_promisc = bd->bd_promisc; 2881 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2882 d->bd_direction = bd->bd_direction; 2883 d->bd_feedback = bd->bd_feedback; 2884 d->bd_async = bd->bd_async; 2885 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2886 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2887 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2888 d->bd_sig = bd->bd_sig; 2889 d->bd_slen = bd->bd_slen; 2890 d->bd_hlen = bd->bd_hlen; 2891 d->bd_bufsize = bd->bd_bufsize; 2892 d->bd_pid = bd->bd_pid; 2893 strlcpy(d->bd_ifname, 2894 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2895 d->bd_locked = bd->bd_locked; 2896 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2897 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2898 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2899 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2900 d->bd_bufmode = bd->bd_bufmode; 2901 } 2902 2903 /* 2904 * Handle `netstat -B' stats request 2905 */ 2906 static int 2907 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2908 { 2909 static const struct xbpf_d zerostats; 2910 struct xbpf_d *xbdbuf, *xbd, tempstats; 2911 int index, error; 2912 struct bpf_if *bp; 2913 struct bpf_d *bd; 2914 2915 /* 2916 * XXX This is not technically correct. It is possible for non 2917 * privileged users to open bpf devices. It would make sense 2918 * if the users who opened the devices were able to retrieve 2919 * the statistics for them, too. 2920 */ 2921 error = priv_check(req->td, PRIV_NET_BPF); 2922 if (error) 2923 return (error); 2924 /* 2925 * Check to see if the user is requesting that the counters be 2926 * zeroed out. Explicitly check that the supplied data is zeroed, 2927 * as we aren't allowing the user to set the counters currently. 2928 */ 2929 if (req->newptr != NULL) { 2930 if (req->newlen != sizeof(tempstats)) 2931 return (EINVAL); 2932 memset(&tempstats, 0, sizeof(tempstats)); 2933 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2934 if (error) 2935 return (error); 2936 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2937 return (EINVAL); 2938 bpf_zero_counters(); 2939 return (0); 2940 } 2941 if (req->oldptr == NULL) 2942 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2943 if (bpf_bpfd_cnt == 0) 2944 return (SYSCTL_OUT(req, 0, 0)); 2945 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2946 BPF_LOCK(); 2947 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2948 BPF_UNLOCK(); 2949 free(xbdbuf, M_BPF); 2950 return (ENOMEM); 2951 } 2952 index = 0; 2953 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2954 BPFIF_RLOCK(bp); 2955 /* Send writers-only first */ 2956 LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2957 xbd = &xbdbuf[index++]; 2958 BPFD_LOCK(bd); 2959 bpfstats_fill_xbpf(xbd, bd); 2960 BPFD_UNLOCK(bd); 2961 } 2962 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2963 xbd = &xbdbuf[index++]; 2964 BPFD_LOCK(bd); 2965 bpfstats_fill_xbpf(xbd, bd); 2966 BPFD_UNLOCK(bd); 2967 } 2968 BPFIF_RUNLOCK(bp); 2969 } 2970 BPF_UNLOCK(); 2971 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2972 free(xbdbuf, M_BPF); 2973 return (error); 2974 } 2975 2976 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 2977 2978 #else /* !DEV_BPF && !NETGRAPH_BPF */ 2979 /* 2980 * NOP stubs to allow bpf-using drivers to load and function. 2981 * 2982 * A 'better' implementation would allow the core bpf functionality 2983 * to be loaded at runtime. 2984 */ 2985 static struct bpf_if bp_null; 2986 2987 void 2988 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2989 { 2990 } 2991 2992 void 2993 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2994 { 2995 } 2996 2997 void 2998 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 2999 { 3000 } 3001 3002 void 3003 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3004 { 3005 3006 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3007 } 3008 3009 void 3010 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3011 { 3012 3013 *driverp = &bp_null; 3014 } 3015 3016 void 3017 bpfdetach(struct ifnet *ifp) 3018 { 3019 } 3020 3021 u_int 3022 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3023 { 3024 return -1; /* "no filter" behaviour */ 3025 } 3026 3027 int 3028 bpf_validate(const struct bpf_insn *f, int len) 3029 { 3030 return 0; /* false */ 3031 } 3032 3033 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3034 3035 #ifdef DDB 3036 static void 3037 bpf_show_bpf_if(struct bpf_if *bpf_if) 3038 { 3039 3040 if (bpf_if == NULL) 3041 return; 3042 db_printf("%p:\n", bpf_if); 3043 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3044 /* bif_ext.bif_next */ 3045 /* bif_ext.bif_dlist */ 3046 BPF_DB_PRINTF("%#x", bif_dlt); 3047 BPF_DB_PRINTF("%u", bif_hdrlen); 3048 BPF_DB_PRINTF("%p", bif_ifp); 3049 /* bif_lock */ 3050 /* bif_wlist */ 3051 BPF_DB_PRINTF("%#x", bif_flags); 3052 } 3053 3054 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3055 { 3056 3057 if (!have_addr) { 3058 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3059 return; 3060 } 3061 3062 bpf_show_bpf_if((struct bpf_if *)addr); 3063 } 3064 #endif 3065