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 * Copyright (c) 2019 Andrey V. Elsukov <ae@FreeBSD.org> 7 * 8 * This code is derived from the Stanford/CMU enet packet filter, 9 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 10 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 11 * Berkeley Laboratory. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 38 */ 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include "opt_bpf.h" 44 #include "opt_ddb.h" 45 #include "opt_netgraph.h" 46 47 #include <sys/param.h> 48 #include <sys/conf.h> 49 #include <sys/eventhandler.h> 50 #include <sys/fcntl.h> 51 #include <sys/jail.h> 52 #include <sys/ktr.h> 53 #include <sys/lock.h> 54 #include <sys/malloc.h> 55 #include <sys/mbuf.h> 56 #include <sys/mutex.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 #include <sys/systm.h> 67 68 #include <sys/event.h> 69 #include <sys/file.h> 70 #include <sys/poll.h> 71 #include <sys/proc.h> 72 73 #include <sys/socket.h> 74 75 #ifdef DDB 76 #include <ddb/ddb.h> 77 #endif 78 79 #include <net/if.h> 80 #include <net/if_var.h> 81 #include <net/if_dl.h> 82 #include <net/bpf.h> 83 #include <net/bpf_buffer.h> 84 #ifdef BPF_JITTER 85 #include <net/bpf_jitter.h> 86 #endif 87 #include <net/bpf_zerocopy.h> 88 #include <net/bpfdesc.h> 89 #include <net/route.h> 90 #include <net/vnet.h> 91 92 #include <netinet/in.h> 93 #include <netinet/if_ether.h> 94 #include <sys/kernel.h> 95 #include <sys/sysctl.h> 96 97 #include <net80211/ieee80211_freebsd.h> 98 99 #include <security/mac/mac_framework.h> 100 101 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 102 103 static struct bpf_if_ext dead_bpf_if = { 104 .bif_dlist = CK_LIST_HEAD_INITIALIZER() 105 }; 106 107 struct bpf_if { 108 #define bif_next bif_ext.bif_next 109 #define bif_dlist bif_ext.bif_dlist 110 struct bpf_if_ext bif_ext; /* public members */ 111 u_int bif_dlt; /* link layer type */ 112 u_int bif_hdrlen; /* length of link header */ 113 struct bpfd_list bif_wlist; /* writer-only list */ 114 struct ifnet *bif_ifp; /* corresponding interface */ 115 struct bpf_if **bif_bpf; /* Pointer to pointer to us */ 116 volatile u_int bif_refcnt; 117 struct epoch_context epoch_ctx; 118 }; 119 120 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); 121 122 struct bpf_program_buffer { 123 struct epoch_context epoch_ctx; 124 #ifdef BPF_JITTER 125 bpf_jit_filter *func; 126 #endif 127 void *buffer[0]; 128 }; 129 130 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 131 132 #define PRINET 26 /* interruptible */ 133 134 #define SIZEOF_BPF_HDR(type) \ 135 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 136 137 #ifdef COMPAT_FREEBSD32 138 #include <sys/mount.h> 139 #include <compat/freebsd32/freebsd32.h> 140 #define BPF_ALIGNMENT32 sizeof(int32_t) 141 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) 142 143 #ifndef BURN_BRIDGES 144 /* 145 * 32-bit version of structure prepended to each packet. We use this header 146 * instead of the standard one for 32-bit streams. We mark the a stream as 147 * 32-bit the first time we see a 32-bit compat ioctl request. 148 */ 149 struct bpf_hdr32 { 150 struct timeval32 bh_tstamp; /* time stamp */ 151 uint32_t bh_caplen; /* length of captured portion */ 152 uint32_t bh_datalen; /* original length of packet */ 153 uint16_t bh_hdrlen; /* length of bpf header (this struct 154 plus alignment padding) */ 155 }; 156 #endif 157 158 struct bpf_program32 { 159 u_int bf_len; 160 uint32_t bf_insns; 161 }; 162 163 struct bpf_dltlist32 { 164 u_int bfl_len; 165 u_int bfl_list; 166 }; 167 168 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 169 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 170 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 171 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 172 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 173 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 174 #endif 175 176 #define BPF_LOCK() sx_xlock(&bpf_sx) 177 #define BPF_UNLOCK() sx_xunlock(&bpf_sx) 178 #define BPF_LOCK_ASSERT() sx_assert(&bpf_sx, SA_XLOCKED) 179 /* 180 * bpf_iflist is a list of BPF interface structures, each corresponding to a 181 * specific DLT. The same network interface might have several BPF interface 182 * structures registered by different layers in the stack (i.e., 802.11 183 * frames, ethernet frames, etc). 184 */ 185 CK_LIST_HEAD(bpf_iflist, bpf_if); 186 static struct bpf_iflist bpf_iflist; 187 static struct sx bpf_sx; /* bpf global lock */ 188 static int bpf_bpfd_cnt; 189 190 static void bpfif_ref(struct bpf_if *); 191 static void bpfif_rele(struct bpf_if *); 192 193 static void bpfd_ref(struct bpf_d *); 194 static void bpfd_rele(struct bpf_d *); 195 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 196 static void bpf_detachd(struct bpf_d *); 197 static void bpf_detachd_locked(struct bpf_d *, bool); 198 static void bpfd_free(epoch_context_t); 199 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 200 struct sockaddr *, int *, struct bpf_d *); 201 static int bpf_setif(struct bpf_d *, struct ifreq *); 202 static void bpf_timed_out(void *); 203 static __inline void 204 bpf_wakeup(struct bpf_d *); 205 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 206 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 207 struct bintime *); 208 static void reset_d(struct bpf_d *); 209 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 210 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 211 static int bpf_setdlt(struct bpf_d *, u_int); 212 static void filt_bpfdetach(struct knote *); 213 static int filt_bpfread(struct knote *, long); 214 static void bpf_drvinit(void *); 215 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 216 217 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 218 int bpf_maxinsns = BPF_MAXINSNS; 219 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 220 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 221 static int bpf_zerocopy_enable = 0; 222 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 223 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 224 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 225 bpf_stats_sysctl, "bpf statistics portal"); 226 227 VNET_DEFINE_STATIC(int, bpf_optimize_writers) = 0; 228 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 229 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RW, 230 &VNET_NAME(bpf_optimize_writers), 0, 231 "Do not send packets until BPF program is set"); 232 233 static d_open_t bpfopen; 234 static d_read_t bpfread; 235 static d_write_t bpfwrite; 236 static d_ioctl_t bpfioctl; 237 static d_poll_t bpfpoll; 238 static d_kqfilter_t bpfkqfilter; 239 240 static struct cdevsw bpf_cdevsw = { 241 .d_version = D_VERSION, 242 .d_open = bpfopen, 243 .d_read = bpfread, 244 .d_write = bpfwrite, 245 .d_ioctl = bpfioctl, 246 .d_poll = bpfpoll, 247 .d_name = "bpf", 248 .d_kqfilter = bpfkqfilter, 249 }; 250 251 static struct filterops bpfread_filtops = { 252 .f_isfd = 1, 253 .f_detach = filt_bpfdetach, 254 .f_event = filt_bpfread, 255 }; 256 257 /* 258 * LOCKING MODEL USED BY BPF 259 * 260 * Locks: 261 * 1) global lock (BPF_LOCK). Sx, used to protect some global counters, 262 * every bpf_iflist changes, serializes ioctl access to bpf descriptors. 263 * 2) Descriptor lock. Mutex, used to protect BPF buffers and various 264 * structure fields used by bpf_*tap* code. 265 * 266 * Lock order: global lock, then descriptor lock. 267 * 268 * There are several possible consumers: 269 * 270 * 1. The kernel registers interface pointer with bpfattach(). 271 * Each call allocates new bpf_if structure, references ifnet pointer 272 * and links bpf_if into bpf_iflist chain. This is protected with global 273 * lock. 274 * 275 * 2. An userland application uses ioctl() call to bpf_d descriptor. 276 * All such call are serialized with global lock. BPF filters can be 277 * changed, but pointer to old filter will be freed using NET_EPOCH_CALL(). 278 * Thus it should be safe for bpf_tap/bpf_mtap* code to do access to 279 * filter pointers, even if change will happen during bpf_tap execution. 280 * Destroying of bpf_d descriptor also is doing using NET_EPOCH_CALL(). 281 * 282 * 3. An userland application can write packets into bpf_d descriptor. 283 * There we need to be sure, that ifnet won't disappear during bpfwrite(). 284 * 285 * 4. The kernel invokes bpf_tap/bpf_mtap* functions. The access to 286 * bif_dlist is protected with net_epoch_preempt section. So, it should 287 * be safe to make access to bpf_d descriptor inside the section. 288 * 289 * 5. The kernel invokes bpfdetach() on interface destroying. All lists 290 * are modified with global lock held and actual free() is done using 291 * NET_EPOCH_CALL(). 292 */ 293 294 static void 295 bpfif_free(epoch_context_t ctx) 296 { 297 struct bpf_if *bp; 298 299 bp = __containerof(ctx, struct bpf_if, epoch_ctx); 300 if_rele(bp->bif_ifp); 301 free(bp, M_BPF); 302 } 303 304 static void 305 bpfif_ref(struct bpf_if *bp) 306 { 307 308 refcount_acquire(&bp->bif_refcnt); 309 } 310 311 static void 312 bpfif_rele(struct bpf_if *bp) 313 { 314 315 if (!refcount_release(&bp->bif_refcnt)) 316 return; 317 NET_EPOCH_CALL(bpfif_free, &bp->epoch_ctx); 318 } 319 320 static void 321 bpfd_ref(struct bpf_d *d) 322 { 323 324 refcount_acquire(&d->bd_refcnt); 325 } 326 327 static void 328 bpfd_rele(struct bpf_d *d) 329 { 330 331 if (!refcount_release(&d->bd_refcnt)) 332 return; 333 NET_EPOCH_CALL(bpfd_free, &d->epoch_ctx); 334 } 335 336 static struct bpf_program_buffer* 337 bpf_program_buffer_alloc(size_t size, int flags) 338 { 339 340 return (malloc(sizeof(struct bpf_program_buffer) + size, 341 M_BPF, flags)); 342 } 343 344 static void 345 bpf_program_buffer_free(epoch_context_t ctx) 346 { 347 struct bpf_program_buffer *ptr; 348 349 ptr = __containerof(ctx, struct bpf_program_buffer, epoch_ctx); 350 #ifdef BPF_JITTER 351 if (ptr->func != NULL) 352 bpf_destroy_jit_filter(ptr->func); 353 #endif 354 free(ptr, M_BPF); 355 } 356 357 /* 358 * Wrapper functions for various buffering methods. If the set of buffer 359 * modes expands, we will probably want to introduce a switch data structure 360 * similar to protosw, et. 361 */ 362 static void 363 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 364 u_int len) 365 { 366 367 BPFD_LOCK_ASSERT(d); 368 369 switch (d->bd_bufmode) { 370 case BPF_BUFMODE_BUFFER: 371 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 372 373 case BPF_BUFMODE_ZBUF: 374 counter_u64_add(d->bd_zcopy, 1); 375 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 376 377 default: 378 panic("bpf_buf_append_bytes"); 379 } 380 } 381 382 static void 383 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 384 u_int len) 385 { 386 387 BPFD_LOCK_ASSERT(d); 388 389 switch (d->bd_bufmode) { 390 case BPF_BUFMODE_BUFFER: 391 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 392 393 case BPF_BUFMODE_ZBUF: 394 counter_u64_add(d->bd_zcopy, 1); 395 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 396 397 default: 398 panic("bpf_buf_append_mbuf"); 399 } 400 } 401 402 /* 403 * This function gets called when the free buffer is re-assigned. 404 */ 405 static void 406 bpf_buf_reclaimed(struct bpf_d *d) 407 { 408 409 BPFD_LOCK_ASSERT(d); 410 411 switch (d->bd_bufmode) { 412 case BPF_BUFMODE_BUFFER: 413 return; 414 415 case BPF_BUFMODE_ZBUF: 416 bpf_zerocopy_buf_reclaimed(d); 417 return; 418 419 default: 420 panic("bpf_buf_reclaimed"); 421 } 422 } 423 424 /* 425 * If the buffer mechanism has a way to decide that a held buffer can be made 426 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 427 * returned if the buffer can be discarded, (0) is returned if it cannot. 428 */ 429 static int 430 bpf_canfreebuf(struct bpf_d *d) 431 { 432 433 BPFD_LOCK_ASSERT(d); 434 435 switch (d->bd_bufmode) { 436 case BPF_BUFMODE_ZBUF: 437 return (bpf_zerocopy_canfreebuf(d)); 438 } 439 return (0); 440 } 441 442 /* 443 * Allow the buffer model to indicate that the current store buffer is 444 * immutable, regardless of the appearance of space. Return (1) if the 445 * buffer is writable, and (0) if not. 446 */ 447 static int 448 bpf_canwritebuf(struct bpf_d *d) 449 { 450 BPFD_LOCK_ASSERT(d); 451 452 switch (d->bd_bufmode) { 453 case BPF_BUFMODE_ZBUF: 454 return (bpf_zerocopy_canwritebuf(d)); 455 } 456 return (1); 457 } 458 459 /* 460 * Notify buffer model that an attempt to write to the store buffer has 461 * resulted in a dropped packet, in which case the buffer may be considered 462 * full. 463 */ 464 static void 465 bpf_buffull(struct bpf_d *d) 466 { 467 468 BPFD_LOCK_ASSERT(d); 469 470 switch (d->bd_bufmode) { 471 case BPF_BUFMODE_ZBUF: 472 bpf_zerocopy_buffull(d); 473 break; 474 } 475 } 476 477 /* 478 * Notify the buffer model that a buffer has moved into the hold position. 479 */ 480 void 481 bpf_bufheld(struct bpf_d *d) 482 { 483 484 BPFD_LOCK_ASSERT(d); 485 486 switch (d->bd_bufmode) { 487 case BPF_BUFMODE_ZBUF: 488 bpf_zerocopy_bufheld(d); 489 break; 490 } 491 } 492 493 static void 494 bpf_free(struct bpf_d *d) 495 { 496 497 switch (d->bd_bufmode) { 498 case BPF_BUFMODE_BUFFER: 499 return (bpf_buffer_free(d)); 500 501 case BPF_BUFMODE_ZBUF: 502 return (bpf_zerocopy_free(d)); 503 504 default: 505 panic("bpf_buf_free"); 506 } 507 } 508 509 static int 510 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 511 { 512 513 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 514 return (EOPNOTSUPP); 515 return (bpf_buffer_uiomove(d, buf, len, uio)); 516 } 517 518 static int 519 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 520 { 521 522 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 523 return (EOPNOTSUPP); 524 return (bpf_buffer_ioctl_sblen(d, i)); 525 } 526 527 static int 528 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 529 { 530 531 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 532 return (EOPNOTSUPP); 533 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 534 } 535 536 static int 537 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 538 { 539 540 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 541 return (EOPNOTSUPP); 542 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 543 } 544 545 static int 546 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 547 { 548 549 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 550 return (EOPNOTSUPP); 551 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 552 } 553 554 /* 555 * General BPF functions. 556 */ 557 static int 558 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 559 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) 560 { 561 const struct ieee80211_bpf_params *p; 562 struct ether_header *eh; 563 struct mbuf *m; 564 int error; 565 int len; 566 int hlen; 567 int slen; 568 569 /* 570 * Build a sockaddr based on the data link layer type. 571 * We do this at this level because the ethernet header 572 * is copied directly into the data field of the sockaddr. 573 * In the case of SLIP, there is no header and the packet 574 * is forwarded as is. 575 * Also, we are careful to leave room at the front of the mbuf 576 * for the link level header. 577 */ 578 switch (linktype) { 579 580 case DLT_SLIP: 581 sockp->sa_family = AF_INET; 582 hlen = 0; 583 break; 584 585 case DLT_EN10MB: 586 sockp->sa_family = AF_UNSPEC; 587 /* XXX Would MAXLINKHDR be better? */ 588 hlen = ETHER_HDR_LEN; 589 break; 590 591 case DLT_FDDI: 592 sockp->sa_family = AF_IMPLINK; 593 hlen = 0; 594 break; 595 596 case DLT_RAW: 597 sockp->sa_family = AF_UNSPEC; 598 hlen = 0; 599 break; 600 601 case DLT_NULL: 602 /* 603 * null interface types require a 4 byte pseudo header which 604 * corresponds to the address family of the packet. 605 */ 606 sockp->sa_family = AF_UNSPEC; 607 hlen = 4; 608 break; 609 610 case DLT_ATM_RFC1483: 611 /* 612 * en atm driver requires 4-byte atm pseudo header. 613 * though it isn't standard, vpi:vci needs to be 614 * specified anyway. 615 */ 616 sockp->sa_family = AF_UNSPEC; 617 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 618 break; 619 620 case DLT_PPP: 621 sockp->sa_family = AF_UNSPEC; 622 hlen = 4; /* This should match PPP_HDRLEN */ 623 break; 624 625 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 626 sockp->sa_family = AF_IEEE80211; 627 hlen = 0; 628 break; 629 630 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 631 sockp->sa_family = AF_IEEE80211; 632 sockp->sa_len = 12; /* XXX != 0 */ 633 hlen = sizeof(struct ieee80211_bpf_params); 634 break; 635 636 default: 637 return (EIO); 638 } 639 640 len = uio->uio_resid; 641 if (len < hlen || len - hlen > ifp->if_mtu) 642 return (EMSGSIZE); 643 644 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR); 645 if (m == NULL) 646 return (EIO); 647 m->m_pkthdr.len = m->m_len = len; 648 *mp = m; 649 650 error = uiomove(mtod(m, u_char *), len, uio); 651 if (error) 652 goto bad; 653 654 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 655 if (slen == 0) { 656 error = EPERM; 657 goto bad; 658 } 659 660 /* Check for multicast destination */ 661 switch (linktype) { 662 case DLT_EN10MB: 663 eh = mtod(m, struct ether_header *); 664 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 665 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 666 ETHER_ADDR_LEN) == 0) 667 m->m_flags |= M_BCAST; 668 else 669 m->m_flags |= M_MCAST; 670 } 671 if (d->bd_hdrcmplt == 0) { 672 memcpy(eh->ether_shost, IF_LLADDR(ifp), 673 sizeof(eh->ether_shost)); 674 } 675 break; 676 } 677 678 /* 679 * Make room for link header, and copy it to sockaddr 680 */ 681 if (hlen != 0) { 682 if (sockp->sa_family == AF_IEEE80211) { 683 /* 684 * Collect true length from the parameter header 685 * NB: sockp is known to be zero'd so if we do a 686 * short copy unspecified parameters will be 687 * zero. 688 * NB: packet may not be aligned after stripping 689 * bpf params 690 * XXX check ibp_vers 691 */ 692 p = mtod(m, const struct ieee80211_bpf_params *); 693 hlen = p->ibp_len; 694 if (hlen > sizeof(sockp->sa_data)) { 695 error = EINVAL; 696 goto bad; 697 } 698 } 699 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 700 } 701 *hdrlen = hlen; 702 703 return (0); 704 bad: 705 m_freem(m); 706 return (error); 707 } 708 709 /* 710 * Attach descriptor to the bpf interface, i.e. make d listen on bp, 711 * then reset its buffers and counters with reset_d(). 712 */ 713 static void 714 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 715 { 716 int op_w; 717 718 BPF_LOCK_ASSERT(); 719 720 /* 721 * Save sysctl value to protect from sysctl change 722 * between reads 723 */ 724 op_w = V_bpf_optimize_writers || d->bd_writer; 725 726 if (d->bd_bif != NULL) 727 bpf_detachd_locked(d, false); 728 /* 729 * Point d at bp, and add d to the interface's list. 730 * Since there are many applications using BPF for 731 * sending raw packets only (dhcpd, cdpd are good examples) 732 * we can delay adding d to the list of active listeners until 733 * some filter is configured. 734 */ 735 736 BPFD_LOCK(d); 737 /* 738 * Hold reference to bpif while descriptor uses this interface. 739 */ 740 bpfif_ref(bp); 741 d->bd_bif = bp; 742 if (op_w != 0) { 743 /* Add to writers-only list */ 744 CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 745 /* 746 * We decrement bd_writer on every filter set operation. 747 * First BIOCSETF is done by pcap_open_live() to set up 748 * snap length. After that appliation usually sets its own 749 * filter. 750 */ 751 d->bd_writer = 2; 752 } else 753 CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 754 755 reset_d(d); 756 BPFD_UNLOCK(d); 757 bpf_bpfd_cnt++; 758 759 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 760 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 761 762 if (op_w == 0) 763 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 764 } 765 766 /* 767 * Check if we need to upgrade our descriptor @d from write-only mode. 768 */ 769 static int 770 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 771 int flen) 772 { 773 int is_snap, need_upgrade; 774 775 /* 776 * Check if we've already upgraded or new filter is empty. 777 */ 778 if (d->bd_writer == 0 || fcode == NULL) 779 return (0); 780 781 need_upgrade = 0; 782 783 /* 784 * Check if cmd looks like snaplen setting from 785 * pcap_bpf.c:pcap_open_live(). 786 * Note we're not checking .k value here: 787 * while pcap_open_live() definitely sets to non-zero value, 788 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 789 * do not consider upgrading immediately 790 */ 791 if (cmd == BIOCSETF && flen == 1 && 792 fcode[0].code == (BPF_RET | BPF_K)) 793 is_snap = 1; 794 else 795 is_snap = 0; 796 797 if (is_snap == 0) { 798 /* 799 * We're setting first filter and it doesn't look like 800 * setting snaplen. We're probably using bpf directly. 801 * Upgrade immediately. 802 */ 803 need_upgrade = 1; 804 } else { 805 /* 806 * Do not require upgrade by first BIOCSETF 807 * (used to set snaplen) by pcap_open_live(). 808 */ 809 810 if (--d->bd_writer == 0) { 811 /* 812 * First snaplen filter has already 813 * been set. This is probably catch-all 814 * filter 815 */ 816 need_upgrade = 1; 817 } 818 } 819 820 CTR5(KTR_NET, 821 "%s: filter function set by pid %d, " 822 "bd_writer counter %d, snap %d upgrade %d", 823 __func__, d->bd_pid, d->bd_writer, 824 is_snap, need_upgrade); 825 826 return (need_upgrade); 827 } 828 829 /* 830 * Detach a file from its interface. 831 */ 832 static void 833 bpf_detachd(struct bpf_d *d) 834 { 835 BPF_LOCK(); 836 bpf_detachd_locked(d, false); 837 BPF_UNLOCK(); 838 } 839 840 static void 841 bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) 842 { 843 struct bpf_if *bp; 844 struct ifnet *ifp; 845 int error; 846 847 BPF_LOCK_ASSERT(); 848 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 849 850 /* Check if descriptor is attached */ 851 if ((bp = d->bd_bif) == NULL) 852 return; 853 854 BPFD_LOCK(d); 855 /* Remove d from the interface's descriptor list. */ 856 CK_LIST_REMOVE(d, bd_next); 857 /* Save bd_writer value */ 858 error = d->bd_writer; 859 ifp = bp->bif_ifp; 860 d->bd_bif = NULL; 861 if (detached_ifp) { 862 /* 863 * Notify descriptor as it's detached, so that any 864 * sleepers wake up and get ENXIO. 865 */ 866 bpf_wakeup(d); 867 } 868 BPFD_UNLOCK(d); 869 bpf_bpfd_cnt--; 870 871 /* Call event handler iff d is attached */ 872 if (error == 0) 873 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 874 875 /* 876 * Check if this descriptor had requested promiscuous mode. 877 * If so and ifnet is not detached, turn it off. 878 */ 879 if (d->bd_promisc && !detached_ifp) { 880 d->bd_promisc = 0; 881 CURVNET_SET(ifp->if_vnet); 882 error = ifpromisc(ifp, 0); 883 CURVNET_RESTORE(); 884 if (error != 0 && error != ENXIO) { 885 /* 886 * ENXIO can happen if a pccard is unplugged 887 * Something is really wrong if we were able to put 888 * the driver into promiscuous mode, but can't 889 * take it out. 890 */ 891 if_printf(bp->bif_ifp, 892 "bpf_detach: ifpromisc failed (%d)\n", error); 893 } 894 } 895 bpfif_rele(bp); 896 } 897 898 /* 899 * Close the descriptor by detaching it from its interface, 900 * deallocating its buffers, and marking it free. 901 */ 902 static void 903 bpf_dtor(void *data) 904 { 905 struct bpf_d *d = data; 906 907 BPFD_LOCK(d); 908 if (d->bd_state == BPF_WAITING) 909 callout_stop(&d->bd_callout); 910 d->bd_state = BPF_IDLE; 911 BPFD_UNLOCK(d); 912 funsetown(&d->bd_sigio); 913 bpf_detachd(d); 914 #ifdef MAC 915 mac_bpfdesc_destroy(d); 916 #endif /* MAC */ 917 seldrain(&d->bd_sel); 918 knlist_destroy(&d->bd_sel.si_note); 919 callout_drain(&d->bd_callout); 920 bpfd_rele(d); 921 } 922 923 /* 924 * Open ethernet device. Returns ENXIO for illegal minor device number, 925 * EBUSY if file is open by another process. 926 */ 927 /* ARGSUSED */ 928 static int 929 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 930 { 931 struct bpf_d *d; 932 int error; 933 934 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 935 error = devfs_set_cdevpriv(d, bpf_dtor); 936 if (error != 0) { 937 free(d, M_BPF); 938 return (error); 939 } 940 941 /* Setup counters */ 942 d->bd_rcount = counter_u64_alloc(M_WAITOK); 943 d->bd_dcount = counter_u64_alloc(M_WAITOK); 944 d->bd_fcount = counter_u64_alloc(M_WAITOK); 945 d->bd_wcount = counter_u64_alloc(M_WAITOK); 946 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 947 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 948 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 949 950 /* 951 * For historical reasons, perform a one-time initialization call to 952 * the buffer routines, even though we're not yet committed to a 953 * particular buffer method. 954 */ 955 bpf_buffer_init(d); 956 if ((flags & FREAD) == 0) 957 d->bd_writer = 2; 958 d->bd_hbuf_in_use = 0; 959 d->bd_bufmode = BPF_BUFMODE_BUFFER; 960 d->bd_sig = SIGIO; 961 d->bd_direction = BPF_D_INOUT; 962 d->bd_refcnt = 1; 963 BPF_PID_REFRESH(d, td); 964 #ifdef MAC 965 mac_bpfdesc_init(d); 966 mac_bpfdesc_create(td->td_ucred, d); 967 #endif 968 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 969 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 970 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 971 972 return (0); 973 } 974 975 /* 976 * bpfread - read next chunk of packets from buffers 977 */ 978 static int 979 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 980 { 981 struct bpf_d *d; 982 int error; 983 int non_block; 984 int timed_out; 985 986 error = devfs_get_cdevpriv((void **)&d); 987 if (error != 0) 988 return (error); 989 990 /* 991 * Restrict application to use a buffer the same size as 992 * as kernel buffers. 993 */ 994 if (uio->uio_resid != d->bd_bufsize) 995 return (EINVAL); 996 997 non_block = ((ioflag & O_NONBLOCK) != 0); 998 999 BPFD_LOCK(d); 1000 BPF_PID_REFRESH_CUR(d); 1001 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 1002 BPFD_UNLOCK(d); 1003 return (EOPNOTSUPP); 1004 } 1005 if (d->bd_state == BPF_WAITING) 1006 callout_stop(&d->bd_callout); 1007 timed_out = (d->bd_state == BPF_TIMED_OUT); 1008 d->bd_state = BPF_IDLE; 1009 while (d->bd_hbuf_in_use) { 1010 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1011 PRINET|PCATCH, "bd_hbuf", 0); 1012 if (error != 0) { 1013 BPFD_UNLOCK(d); 1014 return (error); 1015 } 1016 } 1017 /* 1018 * If the hold buffer is empty, then do a timed sleep, which 1019 * ends when the timeout expires or when enough packets 1020 * have arrived to fill the store buffer. 1021 */ 1022 while (d->bd_hbuf == NULL) { 1023 if (d->bd_slen != 0) { 1024 /* 1025 * A packet(s) either arrived since the previous 1026 * read or arrived while we were asleep. 1027 */ 1028 if (d->bd_immediate || non_block || timed_out) { 1029 /* 1030 * Rotate the buffers and return what's here 1031 * if we are in immediate mode, non-blocking 1032 * flag is set, or this descriptor timed out. 1033 */ 1034 ROTATE_BUFFERS(d); 1035 break; 1036 } 1037 } 1038 1039 /* 1040 * No data is available, check to see if the bpf device 1041 * is still pointed at a real interface. If not, return 1042 * ENXIO so that the userland process knows to rebind 1043 * it before using it again. 1044 */ 1045 if (d->bd_bif == NULL) { 1046 BPFD_UNLOCK(d); 1047 return (ENXIO); 1048 } 1049 1050 if (non_block) { 1051 BPFD_UNLOCK(d); 1052 return (EWOULDBLOCK); 1053 } 1054 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 1055 "bpf", d->bd_rtout); 1056 if (error == EINTR || error == ERESTART) { 1057 BPFD_UNLOCK(d); 1058 return (error); 1059 } 1060 if (error == EWOULDBLOCK) { 1061 /* 1062 * On a timeout, return what's in the buffer, 1063 * which may be nothing. If there is something 1064 * in the store buffer, we can rotate the buffers. 1065 */ 1066 if (d->bd_hbuf) 1067 /* 1068 * We filled up the buffer in between 1069 * getting the timeout and arriving 1070 * here, so we don't need to rotate. 1071 */ 1072 break; 1073 1074 if (d->bd_slen == 0) { 1075 BPFD_UNLOCK(d); 1076 return (0); 1077 } 1078 ROTATE_BUFFERS(d); 1079 break; 1080 } 1081 } 1082 /* 1083 * At this point, we know we have something in the hold slot. 1084 */ 1085 d->bd_hbuf_in_use = 1; 1086 BPFD_UNLOCK(d); 1087 1088 /* 1089 * Move data from hold buffer into user space. 1090 * We know the entire buffer is transferred since 1091 * we checked above that the read buffer is bpf_bufsize bytes. 1092 * 1093 * We do not have to worry about simultaneous reads because 1094 * we waited for sole access to the hold buffer above. 1095 */ 1096 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1097 1098 BPFD_LOCK(d); 1099 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1100 d->bd_fbuf = d->bd_hbuf; 1101 d->bd_hbuf = NULL; 1102 d->bd_hlen = 0; 1103 bpf_buf_reclaimed(d); 1104 d->bd_hbuf_in_use = 0; 1105 wakeup(&d->bd_hbuf_in_use); 1106 BPFD_UNLOCK(d); 1107 1108 return (error); 1109 } 1110 1111 /* 1112 * If there are processes sleeping on this descriptor, wake them up. 1113 */ 1114 static __inline void 1115 bpf_wakeup(struct bpf_d *d) 1116 { 1117 1118 BPFD_LOCK_ASSERT(d); 1119 if (d->bd_state == BPF_WAITING) { 1120 callout_stop(&d->bd_callout); 1121 d->bd_state = BPF_IDLE; 1122 } 1123 wakeup(d); 1124 if (d->bd_async && d->bd_sig && d->bd_sigio) 1125 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1126 1127 selwakeuppri(&d->bd_sel, PRINET); 1128 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1129 } 1130 1131 static void 1132 bpf_timed_out(void *arg) 1133 { 1134 struct bpf_d *d = (struct bpf_d *)arg; 1135 1136 BPFD_LOCK_ASSERT(d); 1137 1138 if (callout_pending(&d->bd_callout) || 1139 !callout_active(&d->bd_callout)) 1140 return; 1141 if (d->bd_state == BPF_WAITING) { 1142 d->bd_state = BPF_TIMED_OUT; 1143 if (d->bd_slen != 0) 1144 bpf_wakeup(d); 1145 } 1146 } 1147 1148 static int 1149 bpf_ready(struct bpf_d *d) 1150 { 1151 1152 BPFD_LOCK_ASSERT(d); 1153 1154 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1155 return (1); 1156 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1157 d->bd_slen != 0) 1158 return (1); 1159 return (0); 1160 } 1161 1162 static int 1163 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1164 { 1165 struct route ro; 1166 struct sockaddr dst; 1167 struct epoch_tracker et; 1168 struct bpf_if *bp; 1169 struct bpf_d *d; 1170 struct ifnet *ifp; 1171 struct mbuf *m, *mc; 1172 int error, hlen; 1173 1174 error = devfs_get_cdevpriv((void **)&d); 1175 if (error != 0) 1176 return (error); 1177 1178 NET_EPOCH_ENTER(et); 1179 BPFD_LOCK(d); 1180 BPF_PID_REFRESH_CUR(d); 1181 counter_u64_add(d->bd_wcount, 1); 1182 if ((bp = d->bd_bif) == NULL) { 1183 error = ENXIO; 1184 goto out_locked; 1185 } 1186 1187 ifp = bp->bif_ifp; 1188 if ((ifp->if_flags & IFF_UP) == 0) { 1189 error = ENETDOWN; 1190 goto out_locked; 1191 } 1192 1193 if (uio->uio_resid == 0) 1194 goto out_locked; 1195 1196 bzero(&dst, sizeof(dst)); 1197 m = NULL; 1198 hlen = 0; 1199 1200 /* 1201 * Take extra reference, unlock d and exit from epoch section, 1202 * since bpf_movein() can sleep. 1203 */ 1204 bpfd_ref(d); 1205 NET_EPOCH_EXIT(et); 1206 BPFD_UNLOCK(d); 1207 1208 error = bpf_movein(uio, (int)bp->bif_dlt, ifp, 1209 &m, &dst, &hlen, d); 1210 1211 if (error != 0) { 1212 counter_u64_add(d->bd_wdcount, 1); 1213 bpfd_rele(d); 1214 return (error); 1215 } 1216 1217 BPFD_LOCK(d); 1218 /* 1219 * Check that descriptor is still attached to the interface. 1220 * This can happen on bpfdetach(). To avoid access to detached 1221 * ifnet, free mbuf and return ENXIO. 1222 */ 1223 if (d->bd_bif == NULL) { 1224 counter_u64_add(d->bd_wdcount, 1); 1225 BPFD_UNLOCK(d); 1226 bpfd_rele(d); 1227 m_freem(m); 1228 return (ENXIO); 1229 } 1230 counter_u64_add(d->bd_wfcount, 1); 1231 if (d->bd_hdrcmplt) 1232 dst.sa_family = pseudo_AF_HDRCMPLT; 1233 1234 if (d->bd_feedback) { 1235 mc = m_dup(m, M_NOWAIT); 1236 if (mc != NULL) 1237 mc->m_pkthdr.rcvif = ifp; 1238 /* Set M_PROMISC for outgoing packets to be discarded. */ 1239 if (d->bd_direction == BPF_D_INOUT) 1240 m->m_flags |= M_PROMISC; 1241 } else 1242 mc = NULL; 1243 1244 m->m_pkthdr.len -= hlen; 1245 m->m_len -= hlen; 1246 m->m_data += hlen; /* XXX */ 1247 1248 CURVNET_SET(ifp->if_vnet); 1249 #ifdef MAC 1250 mac_bpfdesc_create_mbuf(d, m); 1251 if (mc != NULL) 1252 mac_bpfdesc_create_mbuf(d, mc); 1253 #endif 1254 1255 bzero(&ro, sizeof(ro)); 1256 if (hlen != 0) { 1257 ro.ro_prepend = (u_char *)&dst.sa_data; 1258 ro.ro_plen = hlen; 1259 ro.ro_flags = RT_HAS_HEADER; 1260 } 1261 1262 /* Avoid possible recursion on BPFD_LOCK(). */ 1263 NET_EPOCH_ENTER(et); 1264 BPFD_UNLOCK(d); 1265 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1266 if (error) 1267 counter_u64_add(d->bd_wdcount, 1); 1268 1269 if (mc != NULL) { 1270 if (error == 0) 1271 (*ifp->if_input)(ifp, mc); 1272 else 1273 m_freem(mc); 1274 } 1275 NET_EPOCH_EXIT(et); 1276 CURVNET_RESTORE(); 1277 bpfd_rele(d); 1278 return (error); 1279 1280 out_locked: 1281 counter_u64_add(d->bd_wdcount, 1); 1282 NET_EPOCH_EXIT(et); 1283 BPFD_UNLOCK(d); 1284 return (error); 1285 } 1286 1287 /* 1288 * Reset a descriptor by flushing its packet buffer and clearing the receive 1289 * and drop counts. This is doable for kernel-only buffers, but with 1290 * zero-copy buffers, we can't write to (or rotate) buffers that are 1291 * currently owned by userspace. It would be nice if we could encapsulate 1292 * this logic in the buffer code rather than here. 1293 */ 1294 static void 1295 reset_d(struct bpf_d *d) 1296 { 1297 1298 BPFD_LOCK_ASSERT(d); 1299 1300 while (d->bd_hbuf_in_use) 1301 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1302 "bd_hbuf", 0); 1303 if ((d->bd_hbuf != NULL) && 1304 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1305 /* Free the hold buffer. */ 1306 d->bd_fbuf = d->bd_hbuf; 1307 d->bd_hbuf = NULL; 1308 d->bd_hlen = 0; 1309 bpf_buf_reclaimed(d); 1310 } 1311 if (bpf_canwritebuf(d)) 1312 d->bd_slen = 0; 1313 counter_u64_zero(d->bd_rcount); 1314 counter_u64_zero(d->bd_dcount); 1315 counter_u64_zero(d->bd_fcount); 1316 counter_u64_zero(d->bd_wcount); 1317 counter_u64_zero(d->bd_wfcount); 1318 counter_u64_zero(d->bd_wdcount); 1319 counter_u64_zero(d->bd_zcopy); 1320 } 1321 1322 /* 1323 * FIONREAD Check for read packet available. 1324 * BIOCGBLEN Get buffer len [for read()]. 1325 * BIOCSETF Set read filter. 1326 * BIOCSETFNR Set read filter without resetting descriptor. 1327 * BIOCSETWF Set write filter. 1328 * BIOCFLUSH Flush read packet buffer. 1329 * BIOCPROMISC Put interface into promiscuous mode. 1330 * BIOCGDLT Get link layer type. 1331 * BIOCGETIF Get interface name. 1332 * BIOCSETIF Set interface. 1333 * BIOCSRTIMEOUT Set read timeout. 1334 * BIOCGRTIMEOUT Get read timeout. 1335 * BIOCGSTATS Get packet stats. 1336 * BIOCIMMEDIATE Set immediate mode. 1337 * BIOCVERSION Get filter language version. 1338 * BIOCGHDRCMPLT Get "header already complete" flag 1339 * BIOCSHDRCMPLT Set "header already complete" flag 1340 * BIOCGDIRECTION Get packet direction flag 1341 * BIOCSDIRECTION Set packet direction flag 1342 * BIOCGTSTAMP Get time stamp format and resolution. 1343 * BIOCSTSTAMP Set time stamp format and resolution. 1344 * BIOCLOCK Set "locked" flag 1345 * BIOCFEEDBACK Set packet feedback mode. 1346 * BIOCSETZBUF Set current zero-copy buffer locations. 1347 * BIOCGETZMAX Get maximum zero-copy buffer size. 1348 * BIOCROTZBUF Force rotation of zero-copy buffer 1349 * BIOCSETBUFMODE Set buffer mode. 1350 * BIOCGETBUFMODE Get current buffer mode. 1351 */ 1352 /* ARGSUSED */ 1353 static int 1354 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1355 struct thread *td) 1356 { 1357 struct bpf_d *d; 1358 int error; 1359 1360 error = devfs_get_cdevpriv((void **)&d); 1361 if (error != 0) 1362 return (error); 1363 1364 /* 1365 * Refresh PID associated with this descriptor. 1366 */ 1367 BPFD_LOCK(d); 1368 BPF_PID_REFRESH(d, td); 1369 if (d->bd_state == BPF_WAITING) 1370 callout_stop(&d->bd_callout); 1371 d->bd_state = BPF_IDLE; 1372 BPFD_UNLOCK(d); 1373 1374 if (d->bd_locked == 1) { 1375 switch (cmd) { 1376 case BIOCGBLEN: 1377 case BIOCFLUSH: 1378 case BIOCGDLT: 1379 case BIOCGDLTLIST: 1380 #ifdef COMPAT_FREEBSD32 1381 case BIOCGDLTLIST32: 1382 #endif 1383 case BIOCGETIF: 1384 case BIOCGRTIMEOUT: 1385 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1386 case BIOCGRTIMEOUT32: 1387 #endif 1388 case BIOCGSTATS: 1389 case BIOCVERSION: 1390 case BIOCGRSIG: 1391 case BIOCGHDRCMPLT: 1392 case BIOCSTSTAMP: 1393 case BIOCFEEDBACK: 1394 case FIONREAD: 1395 case BIOCLOCK: 1396 case BIOCSRTIMEOUT: 1397 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1398 case BIOCSRTIMEOUT32: 1399 #endif 1400 case BIOCIMMEDIATE: 1401 case TIOCGPGRP: 1402 case BIOCROTZBUF: 1403 break; 1404 default: 1405 return (EPERM); 1406 } 1407 } 1408 #ifdef COMPAT_FREEBSD32 1409 /* 1410 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1411 * that it will get 32-bit packet headers. 1412 */ 1413 switch (cmd) { 1414 case BIOCSETF32: 1415 case BIOCSETFNR32: 1416 case BIOCSETWF32: 1417 case BIOCGDLTLIST32: 1418 case BIOCGRTIMEOUT32: 1419 case BIOCSRTIMEOUT32: 1420 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1421 BPFD_LOCK(d); 1422 d->bd_compat32 = 1; 1423 BPFD_UNLOCK(d); 1424 } 1425 } 1426 #endif 1427 1428 CURVNET_SET(TD_TO_VNET(td)); 1429 switch (cmd) { 1430 1431 default: 1432 error = EINVAL; 1433 break; 1434 1435 /* 1436 * Check for read packet available. 1437 */ 1438 case FIONREAD: 1439 { 1440 int n; 1441 1442 BPFD_LOCK(d); 1443 n = d->bd_slen; 1444 while (d->bd_hbuf_in_use) 1445 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1446 PRINET, "bd_hbuf", 0); 1447 if (d->bd_hbuf) 1448 n += d->bd_hlen; 1449 BPFD_UNLOCK(d); 1450 1451 *(int *)addr = n; 1452 break; 1453 } 1454 1455 /* 1456 * Get buffer len [for read()]. 1457 */ 1458 case BIOCGBLEN: 1459 BPFD_LOCK(d); 1460 *(u_int *)addr = d->bd_bufsize; 1461 BPFD_UNLOCK(d); 1462 break; 1463 1464 /* 1465 * Set buffer length. 1466 */ 1467 case BIOCSBLEN: 1468 error = bpf_ioctl_sblen(d, (u_int *)addr); 1469 break; 1470 1471 /* 1472 * Set link layer read filter. 1473 */ 1474 case BIOCSETF: 1475 case BIOCSETFNR: 1476 case BIOCSETWF: 1477 #ifdef COMPAT_FREEBSD32 1478 case BIOCSETF32: 1479 case BIOCSETFNR32: 1480 case BIOCSETWF32: 1481 #endif 1482 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1483 break; 1484 1485 /* 1486 * Flush read packet buffer. 1487 */ 1488 case BIOCFLUSH: 1489 BPFD_LOCK(d); 1490 reset_d(d); 1491 BPFD_UNLOCK(d); 1492 break; 1493 1494 /* 1495 * Put interface into promiscuous mode. 1496 */ 1497 case BIOCPROMISC: 1498 if (d->bd_bif == NULL) { 1499 /* 1500 * No interface attached yet. 1501 */ 1502 error = EINVAL; 1503 break; 1504 } 1505 if (d->bd_promisc == 0) { 1506 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1507 if (error == 0) 1508 d->bd_promisc = 1; 1509 } 1510 break; 1511 1512 /* 1513 * Get current data link type. 1514 */ 1515 case BIOCGDLT: 1516 BPF_LOCK(); 1517 if (d->bd_bif == NULL) 1518 error = EINVAL; 1519 else 1520 *(u_int *)addr = d->bd_bif->bif_dlt; 1521 BPF_UNLOCK(); 1522 break; 1523 1524 /* 1525 * Get a list of supported data link types. 1526 */ 1527 #ifdef COMPAT_FREEBSD32 1528 case BIOCGDLTLIST32: 1529 { 1530 struct bpf_dltlist32 *list32; 1531 struct bpf_dltlist dltlist; 1532 1533 list32 = (struct bpf_dltlist32 *)addr; 1534 dltlist.bfl_len = list32->bfl_len; 1535 dltlist.bfl_list = PTRIN(list32->bfl_list); 1536 BPF_LOCK(); 1537 if (d->bd_bif == NULL) 1538 error = EINVAL; 1539 else { 1540 error = bpf_getdltlist(d, &dltlist); 1541 if (error == 0) 1542 list32->bfl_len = dltlist.bfl_len; 1543 } 1544 BPF_UNLOCK(); 1545 break; 1546 } 1547 #endif 1548 1549 case BIOCGDLTLIST: 1550 BPF_LOCK(); 1551 if (d->bd_bif == NULL) 1552 error = EINVAL; 1553 else 1554 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1555 BPF_UNLOCK(); 1556 break; 1557 1558 /* 1559 * Set data link type. 1560 */ 1561 case BIOCSDLT: 1562 BPF_LOCK(); 1563 if (d->bd_bif == NULL) 1564 error = EINVAL; 1565 else 1566 error = bpf_setdlt(d, *(u_int *)addr); 1567 BPF_UNLOCK(); 1568 break; 1569 1570 /* 1571 * Get interface name. 1572 */ 1573 case BIOCGETIF: 1574 BPF_LOCK(); 1575 if (d->bd_bif == NULL) 1576 error = EINVAL; 1577 else { 1578 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1579 struct ifreq *const ifr = (struct ifreq *)addr; 1580 1581 strlcpy(ifr->ifr_name, ifp->if_xname, 1582 sizeof(ifr->ifr_name)); 1583 } 1584 BPF_UNLOCK(); 1585 break; 1586 1587 /* 1588 * Set interface. 1589 */ 1590 case BIOCSETIF: 1591 { 1592 int alloc_buf, size; 1593 1594 /* 1595 * Behavior here depends on the buffering model. If 1596 * we're using kernel memory buffers, then we can 1597 * allocate them here. If we're using zero-copy, 1598 * then the user process must have registered buffers 1599 * by the time we get here. 1600 */ 1601 alloc_buf = 0; 1602 BPFD_LOCK(d); 1603 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1604 d->bd_sbuf == NULL) 1605 alloc_buf = 1; 1606 BPFD_UNLOCK(d); 1607 if (alloc_buf) { 1608 size = d->bd_bufsize; 1609 error = bpf_buffer_ioctl_sblen(d, &size); 1610 if (error != 0) 1611 break; 1612 } 1613 BPF_LOCK(); 1614 error = bpf_setif(d, (struct ifreq *)addr); 1615 BPF_UNLOCK(); 1616 break; 1617 } 1618 1619 /* 1620 * Set read timeout. 1621 */ 1622 case BIOCSRTIMEOUT: 1623 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1624 case BIOCSRTIMEOUT32: 1625 #endif 1626 { 1627 struct timeval *tv = (struct timeval *)addr; 1628 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1629 struct timeval32 *tv32; 1630 struct timeval tv64; 1631 1632 if (cmd == BIOCSRTIMEOUT32) { 1633 tv32 = (struct timeval32 *)addr; 1634 tv = &tv64; 1635 tv->tv_sec = tv32->tv_sec; 1636 tv->tv_usec = tv32->tv_usec; 1637 } else 1638 #endif 1639 tv = (struct timeval *)addr; 1640 1641 /* 1642 * Subtract 1 tick from tvtohz() since this isn't 1643 * a one-shot timer. 1644 */ 1645 if ((error = itimerfix(tv)) == 0) 1646 d->bd_rtout = tvtohz(tv) - 1; 1647 break; 1648 } 1649 1650 /* 1651 * Get read timeout. 1652 */ 1653 case BIOCGRTIMEOUT: 1654 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1655 case BIOCGRTIMEOUT32: 1656 #endif 1657 { 1658 struct timeval *tv; 1659 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1660 struct timeval32 *tv32; 1661 struct timeval tv64; 1662 1663 if (cmd == BIOCGRTIMEOUT32) 1664 tv = &tv64; 1665 else 1666 #endif 1667 tv = (struct timeval *)addr; 1668 1669 tv->tv_sec = d->bd_rtout / hz; 1670 tv->tv_usec = (d->bd_rtout % hz) * tick; 1671 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1672 if (cmd == BIOCGRTIMEOUT32) { 1673 tv32 = (struct timeval32 *)addr; 1674 tv32->tv_sec = tv->tv_sec; 1675 tv32->tv_usec = tv->tv_usec; 1676 } 1677 #endif 1678 1679 break; 1680 } 1681 1682 /* 1683 * Get packet stats. 1684 */ 1685 case BIOCGSTATS: 1686 { 1687 struct bpf_stat *bs = (struct bpf_stat *)addr; 1688 1689 /* XXXCSJP overflow */ 1690 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1691 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1692 break; 1693 } 1694 1695 /* 1696 * Set immediate mode. 1697 */ 1698 case BIOCIMMEDIATE: 1699 BPFD_LOCK(d); 1700 d->bd_immediate = *(u_int *)addr; 1701 BPFD_UNLOCK(d); 1702 break; 1703 1704 case BIOCVERSION: 1705 { 1706 struct bpf_version *bv = (struct bpf_version *)addr; 1707 1708 bv->bv_major = BPF_MAJOR_VERSION; 1709 bv->bv_minor = BPF_MINOR_VERSION; 1710 break; 1711 } 1712 1713 /* 1714 * Get "header already complete" flag 1715 */ 1716 case BIOCGHDRCMPLT: 1717 BPFD_LOCK(d); 1718 *(u_int *)addr = d->bd_hdrcmplt; 1719 BPFD_UNLOCK(d); 1720 break; 1721 1722 /* 1723 * Set "header already complete" flag 1724 */ 1725 case BIOCSHDRCMPLT: 1726 BPFD_LOCK(d); 1727 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1728 BPFD_UNLOCK(d); 1729 break; 1730 1731 /* 1732 * Get packet direction flag 1733 */ 1734 case BIOCGDIRECTION: 1735 BPFD_LOCK(d); 1736 *(u_int *)addr = d->bd_direction; 1737 BPFD_UNLOCK(d); 1738 break; 1739 1740 /* 1741 * Set packet direction flag 1742 */ 1743 case BIOCSDIRECTION: 1744 { 1745 u_int direction; 1746 1747 direction = *(u_int *)addr; 1748 switch (direction) { 1749 case BPF_D_IN: 1750 case BPF_D_INOUT: 1751 case BPF_D_OUT: 1752 BPFD_LOCK(d); 1753 d->bd_direction = direction; 1754 BPFD_UNLOCK(d); 1755 break; 1756 default: 1757 error = EINVAL; 1758 } 1759 } 1760 break; 1761 1762 /* 1763 * Get packet timestamp format and resolution. 1764 */ 1765 case BIOCGTSTAMP: 1766 BPFD_LOCK(d); 1767 *(u_int *)addr = d->bd_tstamp; 1768 BPFD_UNLOCK(d); 1769 break; 1770 1771 /* 1772 * Set packet timestamp format and resolution. 1773 */ 1774 case BIOCSTSTAMP: 1775 { 1776 u_int func; 1777 1778 func = *(u_int *)addr; 1779 if (BPF_T_VALID(func)) 1780 d->bd_tstamp = func; 1781 else 1782 error = EINVAL; 1783 } 1784 break; 1785 1786 case BIOCFEEDBACK: 1787 BPFD_LOCK(d); 1788 d->bd_feedback = *(u_int *)addr; 1789 BPFD_UNLOCK(d); 1790 break; 1791 1792 case BIOCLOCK: 1793 BPFD_LOCK(d); 1794 d->bd_locked = 1; 1795 BPFD_UNLOCK(d); 1796 break; 1797 1798 case FIONBIO: /* Non-blocking I/O */ 1799 break; 1800 1801 case FIOASYNC: /* Send signal on receive packets */ 1802 BPFD_LOCK(d); 1803 d->bd_async = *(int *)addr; 1804 BPFD_UNLOCK(d); 1805 break; 1806 1807 case FIOSETOWN: 1808 /* 1809 * XXX: Add some sort of locking here? 1810 * fsetown() can sleep. 1811 */ 1812 error = fsetown(*(int *)addr, &d->bd_sigio); 1813 break; 1814 1815 case FIOGETOWN: 1816 BPFD_LOCK(d); 1817 *(int *)addr = fgetown(&d->bd_sigio); 1818 BPFD_UNLOCK(d); 1819 break; 1820 1821 /* This is deprecated, FIOSETOWN should be used instead. */ 1822 case TIOCSPGRP: 1823 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1824 break; 1825 1826 /* This is deprecated, FIOGETOWN should be used instead. */ 1827 case TIOCGPGRP: 1828 *(int *)addr = -fgetown(&d->bd_sigio); 1829 break; 1830 1831 case BIOCSRSIG: /* Set receive signal */ 1832 { 1833 u_int sig; 1834 1835 sig = *(u_int *)addr; 1836 1837 if (sig >= NSIG) 1838 error = EINVAL; 1839 else { 1840 BPFD_LOCK(d); 1841 d->bd_sig = sig; 1842 BPFD_UNLOCK(d); 1843 } 1844 break; 1845 } 1846 case BIOCGRSIG: 1847 BPFD_LOCK(d); 1848 *(u_int *)addr = d->bd_sig; 1849 BPFD_UNLOCK(d); 1850 break; 1851 1852 case BIOCGETBUFMODE: 1853 BPFD_LOCK(d); 1854 *(u_int *)addr = d->bd_bufmode; 1855 BPFD_UNLOCK(d); 1856 break; 1857 1858 case BIOCSETBUFMODE: 1859 /* 1860 * Allow the buffering mode to be changed as long as we 1861 * haven't yet committed to a particular mode. Our 1862 * definition of commitment, for now, is whether or not a 1863 * buffer has been allocated or an interface attached, since 1864 * that's the point where things get tricky. 1865 */ 1866 switch (*(u_int *)addr) { 1867 case BPF_BUFMODE_BUFFER: 1868 break; 1869 1870 case BPF_BUFMODE_ZBUF: 1871 if (bpf_zerocopy_enable) 1872 break; 1873 /* FALLSTHROUGH */ 1874 1875 default: 1876 CURVNET_RESTORE(); 1877 return (EINVAL); 1878 } 1879 1880 BPFD_LOCK(d); 1881 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1882 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1883 BPFD_UNLOCK(d); 1884 CURVNET_RESTORE(); 1885 return (EBUSY); 1886 } 1887 d->bd_bufmode = *(u_int *)addr; 1888 BPFD_UNLOCK(d); 1889 break; 1890 1891 case BIOCGETZMAX: 1892 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1893 break; 1894 1895 case BIOCSETZBUF: 1896 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1897 break; 1898 1899 case BIOCROTZBUF: 1900 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1901 break; 1902 } 1903 CURVNET_RESTORE(); 1904 return (error); 1905 } 1906 1907 /* 1908 * Set d's packet filter program to fp. If this file already has a filter, 1909 * free it and replace it. Returns EINVAL for bogus requests. 1910 * 1911 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1912 * calls. 1913 */ 1914 static int 1915 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1916 { 1917 #ifdef COMPAT_FREEBSD32 1918 struct bpf_program fp_swab; 1919 struct bpf_program32 *fp32; 1920 #endif 1921 struct bpf_program_buffer *fcode; 1922 struct bpf_insn *filter; 1923 #ifdef BPF_JITTER 1924 bpf_jit_filter *jfunc; 1925 #endif 1926 size_t size; 1927 u_int flen; 1928 bool track_event; 1929 1930 #ifdef COMPAT_FREEBSD32 1931 switch (cmd) { 1932 case BIOCSETF32: 1933 case BIOCSETWF32: 1934 case BIOCSETFNR32: 1935 fp32 = (struct bpf_program32 *)fp; 1936 fp_swab.bf_len = fp32->bf_len; 1937 fp_swab.bf_insns = 1938 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1939 fp = &fp_swab; 1940 switch (cmd) { 1941 case BIOCSETF32: 1942 cmd = BIOCSETF; 1943 break; 1944 case BIOCSETWF32: 1945 cmd = BIOCSETWF; 1946 break; 1947 } 1948 break; 1949 } 1950 #endif 1951 1952 filter = NULL; 1953 #ifdef BPF_JITTER 1954 jfunc = NULL; 1955 #endif 1956 /* 1957 * Check new filter validness before acquiring any locks. 1958 * Allocate memory for new filter, if needed. 1959 */ 1960 flen = fp->bf_len; 1961 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1962 return (EINVAL); 1963 size = flen * sizeof(*fp->bf_insns); 1964 if (size > 0) { 1965 /* We're setting up new filter. Copy and check actual data. */ 1966 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1967 filter = (struct bpf_insn *)fcode->buffer; 1968 if (copyin(fp->bf_insns, filter, size) != 0 || 1969 !bpf_validate(filter, flen)) { 1970 free(fcode, M_BPF); 1971 return (EINVAL); 1972 } 1973 #ifdef BPF_JITTER 1974 if (cmd != BIOCSETWF) { 1975 /* 1976 * Filter is copied inside fcode and is 1977 * perfectly valid. 1978 */ 1979 jfunc = bpf_jitter(filter, flen); 1980 } 1981 #endif 1982 } 1983 1984 track_event = false; 1985 fcode = NULL; 1986 1987 BPF_LOCK(); 1988 BPFD_LOCK(d); 1989 /* Set up new filter. */ 1990 if (cmd == BIOCSETWF) { 1991 if (d->bd_wfilter != NULL) { 1992 fcode = __containerof((void *)d->bd_wfilter, 1993 struct bpf_program_buffer, buffer); 1994 #ifdef BPF_JITTER 1995 fcode->func = NULL; 1996 #endif 1997 } 1998 d->bd_wfilter = filter; 1999 } else { 2000 if (d->bd_rfilter != NULL) { 2001 fcode = __containerof((void *)d->bd_rfilter, 2002 struct bpf_program_buffer, buffer); 2003 #ifdef BPF_JITTER 2004 fcode->func = d->bd_bfilter; 2005 #endif 2006 } 2007 d->bd_rfilter = filter; 2008 #ifdef BPF_JITTER 2009 d->bd_bfilter = jfunc; 2010 #endif 2011 if (cmd == BIOCSETF) 2012 reset_d(d); 2013 2014 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 2015 /* 2016 * Filter can be set several times without 2017 * specifying interface. In this case just mark d 2018 * as reader. 2019 */ 2020 d->bd_writer = 0; 2021 if (d->bd_bif != NULL) { 2022 /* 2023 * Remove descriptor from writers-only list 2024 * and add it to active readers list. 2025 */ 2026 CK_LIST_REMOVE(d, bd_next); 2027 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 2028 d, bd_next); 2029 CTR2(KTR_NET, 2030 "%s: upgrade required by pid %d", 2031 __func__, d->bd_pid); 2032 track_event = true; 2033 } 2034 } 2035 } 2036 BPFD_UNLOCK(d); 2037 2038 if (fcode != NULL) 2039 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 2040 2041 if (track_event) 2042 EVENTHANDLER_INVOKE(bpf_track, 2043 d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); 2044 2045 BPF_UNLOCK(); 2046 return (0); 2047 } 2048 2049 /* 2050 * Detach a file from its current interface (if attached at all) and attach 2051 * to the interface indicated by the name stored in ifr. 2052 * Return an errno or 0. 2053 */ 2054 static int 2055 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 2056 { 2057 struct bpf_if *bp; 2058 struct ifnet *theywant; 2059 2060 BPF_LOCK_ASSERT(); 2061 2062 theywant = ifunit(ifr->ifr_name); 2063 if (theywant == NULL || theywant->if_bpf == NULL) 2064 return (ENXIO); 2065 2066 bp = theywant->if_bpf; 2067 /* 2068 * At this point, we expect the buffer is already allocated. If not, 2069 * return an error. 2070 */ 2071 switch (d->bd_bufmode) { 2072 case BPF_BUFMODE_BUFFER: 2073 case BPF_BUFMODE_ZBUF: 2074 if (d->bd_sbuf == NULL) 2075 return (EINVAL); 2076 break; 2077 2078 default: 2079 panic("bpf_setif: bufmode %d", d->bd_bufmode); 2080 } 2081 if (bp != d->bd_bif) 2082 bpf_attachd(d, bp); 2083 else { 2084 BPFD_LOCK(d); 2085 reset_d(d); 2086 BPFD_UNLOCK(d); 2087 } 2088 return (0); 2089 } 2090 2091 /* 2092 * Support for select() and poll() system calls 2093 * 2094 * Return true iff the specific operation will not block indefinitely. 2095 * Otherwise, return false but make a note that a selwakeup() must be done. 2096 */ 2097 static int 2098 bpfpoll(struct cdev *dev, int events, struct thread *td) 2099 { 2100 struct bpf_d *d; 2101 int revents; 2102 2103 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2104 return (events & 2105 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 2106 2107 /* 2108 * Refresh PID associated with this descriptor. 2109 */ 2110 revents = events & (POLLOUT | POLLWRNORM); 2111 BPFD_LOCK(d); 2112 BPF_PID_REFRESH(d, td); 2113 if (events & (POLLIN | POLLRDNORM)) { 2114 if (bpf_ready(d)) 2115 revents |= events & (POLLIN | POLLRDNORM); 2116 else { 2117 selrecord(td, &d->bd_sel); 2118 /* Start the read timeout if necessary. */ 2119 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2120 callout_reset(&d->bd_callout, d->bd_rtout, 2121 bpf_timed_out, d); 2122 d->bd_state = BPF_WAITING; 2123 } 2124 } 2125 } 2126 BPFD_UNLOCK(d); 2127 return (revents); 2128 } 2129 2130 /* 2131 * Support for kevent() system call. Register EVFILT_READ filters and 2132 * reject all others. 2133 */ 2134 int 2135 bpfkqfilter(struct cdev *dev, struct knote *kn) 2136 { 2137 struct bpf_d *d; 2138 2139 if (devfs_get_cdevpriv((void **)&d) != 0 || 2140 kn->kn_filter != EVFILT_READ) 2141 return (1); 2142 2143 /* 2144 * Refresh PID associated with this descriptor. 2145 */ 2146 BPFD_LOCK(d); 2147 BPF_PID_REFRESH_CUR(d); 2148 kn->kn_fop = &bpfread_filtops; 2149 kn->kn_hook = d; 2150 knlist_add(&d->bd_sel.si_note, kn, 1); 2151 BPFD_UNLOCK(d); 2152 2153 return (0); 2154 } 2155 2156 static void 2157 filt_bpfdetach(struct knote *kn) 2158 { 2159 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2160 2161 knlist_remove(&d->bd_sel.si_note, kn, 0); 2162 } 2163 2164 static int 2165 filt_bpfread(struct knote *kn, long hint) 2166 { 2167 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2168 int ready; 2169 2170 BPFD_LOCK_ASSERT(d); 2171 ready = bpf_ready(d); 2172 if (ready) { 2173 kn->kn_data = d->bd_slen; 2174 /* 2175 * Ignore the hold buffer if it is being copied to user space. 2176 */ 2177 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2178 kn->kn_data += d->bd_hlen; 2179 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2180 callout_reset(&d->bd_callout, d->bd_rtout, 2181 bpf_timed_out, d); 2182 d->bd_state = BPF_WAITING; 2183 } 2184 2185 return (ready); 2186 } 2187 2188 #define BPF_TSTAMP_NONE 0 2189 #define BPF_TSTAMP_FAST 1 2190 #define BPF_TSTAMP_NORMAL 2 2191 #define BPF_TSTAMP_EXTERN 3 2192 2193 static int 2194 bpf_ts_quality(int tstype) 2195 { 2196 2197 if (tstype == BPF_T_NONE) 2198 return (BPF_TSTAMP_NONE); 2199 if ((tstype & BPF_T_FAST) != 0) 2200 return (BPF_TSTAMP_FAST); 2201 2202 return (BPF_TSTAMP_NORMAL); 2203 } 2204 2205 static int 2206 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2207 { 2208 struct m_tag *tag; 2209 int quality; 2210 2211 quality = bpf_ts_quality(tstype); 2212 if (quality == BPF_TSTAMP_NONE) 2213 return (quality); 2214 2215 if (m != NULL) { 2216 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2217 if (tag != NULL) { 2218 *bt = *(struct bintime *)(tag + 1); 2219 return (BPF_TSTAMP_EXTERN); 2220 } 2221 } 2222 if (quality == BPF_TSTAMP_NORMAL) 2223 binuptime(bt); 2224 else 2225 getbinuptime(bt); 2226 2227 return (quality); 2228 } 2229 2230 /* 2231 * Incoming linkage from device drivers. Process the packet pkt, of length 2232 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2233 * by each process' filter, and if accepted, stashed into the corresponding 2234 * buffer. 2235 */ 2236 void 2237 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2238 { 2239 struct epoch_tracker et; 2240 struct bintime bt; 2241 struct bpf_d *d; 2242 #ifdef BPF_JITTER 2243 bpf_jit_filter *bf; 2244 #endif 2245 u_int slen; 2246 int gottime; 2247 2248 gottime = BPF_TSTAMP_NONE; 2249 NET_EPOCH_ENTER(et); 2250 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2251 counter_u64_add(d->bd_rcount, 1); 2252 /* 2253 * NB: We dont call BPF_CHECK_DIRECTION() here since there 2254 * is no way for the caller to indiciate to us whether this 2255 * packet is inbound or outbound. In the bpf_mtap() routines, 2256 * we use the interface pointers on the mbuf to figure it out. 2257 */ 2258 #ifdef BPF_JITTER 2259 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2260 if (bf != NULL) 2261 slen = (*(bf->func))(pkt, pktlen, pktlen); 2262 else 2263 #endif 2264 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2265 if (slen != 0) { 2266 /* 2267 * Filter matches. Let's to acquire write lock. 2268 */ 2269 BPFD_LOCK(d); 2270 counter_u64_add(d->bd_fcount, 1); 2271 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2272 gottime = bpf_gettime(&bt, d->bd_tstamp, 2273 NULL); 2274 #ifdef MAC 2275 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2276 #endif 2277 catchpacket(d, pkt, pktlen, slen, 2278 bpf_append_bytes, &bt); 2279 BPFD_UNLOCK(d); 2280 } 2281 } 2282 NET_EPOCH_EXIT(et); 2283 } 2284 2285 #define BPF_CHECK_DIRECTION(d, r, i) \ 2286 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2287 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2288 2289 /* 2290 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2291 * Locking model is explained in bpf_tap(). 2292 */ 2293 void 2294 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2295 { 2296 struct epoch_tracker et; 2297 struct bintime bt; 2298 struct bpf_d *d; 2299 #ifdef BPF_JITTER 2300 bpf_jit_filter *bf; 2301 #endif 2302 u_int pktlen, slen; 2303 int gottime; 2304 2305 /* Skip outgoing duplicate packets. */ 2306 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2307 m->m_flags &= ~M_PROMISC; 2308 return; 2309 } 2310 2311 pktlen = m_length(m, NULL); 2312 gottime = BPF_TSTAMP_NONE; 2313 2314 NET_EPOCH_ENTER(et); 2315 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2316 if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) 2317 continue; 2318 counter_u64_add(d->bd_rcount, 1); 2319 #ifdef BPF_JITTER 2320 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2321 /* XXX We cannot handle multiple mbufs. */ 2322 if (bf != NULL && m->m_next == NULL) 2323 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2324 pktlen); 2325 else 2326 #endif 2327 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2328 if (slen != 0) { 2329 BPFD_LOCK(d); 2330 2331 counter_u64_add(d->bd_fcount, 1); 2332 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2333 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2334 #ifdef MAC 2335 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2336 #endif 2337 catchpacket(d, (u_char *)m, pktlen, slen, 2338 bpf_append_mbuf, &bt); 2339 BPFD_UNLOCK(d); 2340 } 2341 } 2342 NET_EPOCH_EXIT(et); 2343 } 2344 2345 /* 2346 * Incoming linkage from device drivers, when packet is in 2347 * an mbuf chain and to be prepended by a contiguous header. 2348 */ 2349 void 2350 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2351 { 2352 struct epoch_tracker et; 2353 struct bintime bt; 2354 struct mbuf mb; 2355 struct bpf_d *d; 2356 u_int pktlen, slen; 2357 int gottime; 2358 2359 /* Skip outgoing duplicate packets. */ 2360 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2361 m->m_flags &= ~M_PROMISC; 2362 return; 2363 } 2364 2365 pktlen = m_length(m, NULL); 2366 /* 2367 * Craft on-stack mbuf suitable for passing to bpf_filter. 2368 * Note that we cut corners here; we only setup what's 2369 * absolutely needed--this mbuf should never go anywhere else. 2370 */ 2371 mb.m_flags = 0; 2372 mb.m_next = m; 2373 mb.m_data = data; 2374 mb.m_len = dlen; 2375 pktlen += dlen; 2376 2377 gottime = BPF_TSTAMP_NONE; 2378 2379 NET_EPOCH_ENTER(et); 2380 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2381 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2382 continue; 2383 counter_u64_add(d->bd_rcount, 1); 2384 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2385 if (slen != 0) { 2386 BPFD_LOCK(d); 2387 2388 counter_u64_add(d->bd_fcount, 1); 2389 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2390 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2391 #ifdef MAC 2392 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2393 #endif 2394 catchpacket(d, (u_char *)&mb, pktlen, slen, 2395 bpf_append_mbuf, &bt); 2396 BPFD_UNLOCK(d); 2397 } 2398 } 2399 NET_EPOCH_EXIT(et); 2400 } 2401 2402 #undef BPF_CHECK_DIRECTION 2403 #undef BPF_TSTAMP_NONE 2404 #undef BPF_TSTAMP_FAST 2405 #undef BPF_TSTAMP_NORMAL 2406 #undef BPF_TSTAMP_EXTERN 2407 2408 static int 2409 bpf_hdrlen(struct bpf_d *d) 2410 { 2411 int hdrlen; 2412 2413 hdrlen = d->bd_bif->bif_hdrlen; 2414 #ifndef BURN_BRIDGES 2415 if (d->bd_tstamp == BPF_T_NONE || 2416 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2417 #ifdef COMPAT_FREEBSD32 2418 if (d->bd_compat32) 2419 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2420 else 2421 #endif 2422 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2423 else 2424 #endif 2425 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2426 #ifdef COMPAT_FREEBSD32 2427 if (d->bd_compat32) 2428 hdrlen = BPF_WORDALIGN32(hdrlen); 2429 else 2430 #endif 2431 hdrlen = BPF_WORDALIGN(hdrlen); 2432 2433 return (hdrlen - d->bd_bif->bif_hdrlen); 2434 } 2435 2436 static void 2437 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2438 { 2439 struct bintime bt2, boottimebin; 2440 struct timeval tsm; 2441 struct timespec tsn; 2442 2443 if ((tstype & BPF_T_MONOTONIC) == 0) { 2444 bt2 = *bt; 2445 getboottimebin(&boottimebin); 2446 bintime_add(&bt2, &boottimebin); 2447 bt = &bt2; 2448 } 2449 switch (BPF_T_FORMAT(tstype)) { 2450 case BPF_T_MICROTIME: 2451 bintime2timeval(bt, &tsm); 2452 ts->bt_sec = tsm.tv_sec; 2453 ts->bt_frac = tsm.tv_usec; 2454 break; 2455 case BPF_T_NANOTIME: 2456 bintime2timespec(bt, &tsn); 2457 ts->bt_sec = tsn.tv_sec; 2458 ts->bt_frac = tsn.tv_nsec; 2459 break; 2460 case BPF_T_BINTIME: 2461 ts->bt_sec = bt->sec; 2462 ts->bt_frac = bt->frac; 2463 break; 2464 } 2465 } 2466 2467 /* 2468 * Move the packet data from interface memory (pkt) into the 2469 * store buffer. "cpfn" is the routine called to do the actual data 2470 * transfer. bcopy is passed in to copy contiguous chunks, while 2471 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2472 * pkt is really an mbuf. 2473 */ 2474 static void 2475 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2476 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2477 struct bintime *bt) 2478 { 2479 struct bpf_xhdr hdr; 2480 #ifndef BURN_BRIDGES 2481 struct bpf_hdr hdr_old; 2482 #ifdef COMPAT_FREEBSD32 2483 struct bpf_hdr32 hdr32_old; 2484 #endif 2485 #endif 2486 int caplen, curlen, hdrlen, totlen; 2487 int do_wakeup = 0; 2488 int do_timestamp; 2489 int tstype; 2490 2491 BPFD_LOCK_ASSERT(d); 2492 if (d->bd_bif == NULL) { 2493 /* Descriptor was detached in concurrent thread */ 2494 counter_u64_add(d->bd_dcount, 1); 2495 return; 2496 } 2497 2498 /* 2499 * Detect whether user space has released a buffer back to us, and if 2500 * so, move it from being a hold buffer to a free buffer. This may 2501 * not be the best place to do it (for example, we might only want to 2502 * run this check if we need the space), but for now it's a reliable 2503 * spot to do it. 2504 */ 2505 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2506 d->bd_fbuf = d->bd_hbuf; 2507 d->bd_hbuf = NULL; 2508 d->bd_hlen = 0; 2509 bpf_buf_reclaimed(d); 2510 } 2511 2512 /* 2513 * Figure out how many bytes to move. If the packet is 2514 * greater or equal to the snapshot length, transfer that 2515 * much. Otherwise, transfer the whole packet (unless 2516 * we hit the buffer size limit). 2517 */ 2518 hdrlen = bpf_hdrlen(d); 2519 totlen = hdrlen + min(snaplen, pktlen); 2520 if (totlen > d->bd_bufsize) 2521 totlen = d->bd_bufsize; 2522 2523 /* 2524 * Round up the end of the previous packet to the next longword. 2525 * 2526 * Drop the packet if there's no room and no hope of room 2527 * If the packet would overflow the storage buffer or the storage 2528 * buffer is considered immutable by the buffer model, try to rotate 2529 * the buffer and wakeup pending processes. 2530 */ 2531 #ifdef COMPAT_FREEBSD32 2532 if (d->bd_compat32) 2533 curlen = BPF_WORDALIGN32(d->bd_slen); 2534 else 2535 #endif 2536 curlen = BPF_WORDALIGN(d->bd_slen); 2537 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2538 if (d->bd_fbuf == NULL) { 2539 /* 2540 * There's no room in the store buffer, and no 2541 * prospect of room, so drop the packet. Notify the 2542 * buffer model. 2543 */ 2544 bpf_buffull(d); 2545 counter_u64_add(d->bd_dcount, 1); 2546 return; 2547 } 2548 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2549 ROTATE_BUFFERS(d); 2550 do_wakeup = 1; 2551 curlen = 0; 2552 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2553 /* 2554 * Immediate mode is set, or the read timeout has already 2555 * expired during a select call. A packet arrived, so the 2556 * reader should be woken up. 2557 */ 2558 do_wakeup = 1; 2559 caplen = totlen - hdrlen; 2560 tstype = d->bd_tstamp; 2561 do_timestamp = tstype != BPF_T_NONE; 2562 #ifndef BURN_BRIDGES 2563 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2564 struct bpf_ts ts; 2565 if (do_timestamp) 2566 bpf_bintime2ts(bt, &ts, tstype); 2567 #ifdef COMPAT_FREEBSD32 2568 if (d->bd_compat32) { 2569 bzero(&hdr32_old, sizeof(hdr32_old)); 2570 if (do_timestamp) { 2571 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2572 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2573 } 2574 hdr32_old.bh_datalen = pktlen; 2575 hdr32_old.bh_hdrlen = hdrlen; 2576 hdr32_old.bh_caplen = caplen; 2577 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2578 sizeof(hdr32_old)); 2579 goto copy; 2580 } 2581 #endif 2582 bzero(&hdr_old, sizeof(hdr_old)); 2583 if (do_timestamp) { 2584 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2585 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2586 } 2587 hdr_old.bh_datalen = pktlen; 2588 hdr_old.bh_hdrlen = hdrlen; 2589 hdr_old.bh_caplen = caplen; 2590 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2591 sizeof(hdr_old)); 2592 goto copy; 2593 } 2594 #endif 2595 2596 /* 2597 * Append the bpf header. Note we append the actual header size, but 2598 * move forward the length of the header plus padding. 2599 */ 2600 bzero(&hdr, sizeof(hdr)); 2601 if (do_timestamp) 2602 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2603 hdr.bh_datalen = pktlen; 2604 hdr.bh_hdrlen = hdrlen; 2605 hdr.bh_caplen = caplen; 2606 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2607 2608 /* 2609 * Copy the packet data into the store buffer and update its length. 2610 */ 2611 #ifndef BURN_BRIDGES 2612 copy: 2613 #endif 2614 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2615 d->bd_slen = curlen + totlen; 2616 2617 if (do_wakeup) 2618 bpf_wakeup(d); 2619 } 2620 2621 /* 2622 * Free buffers currently in use by a descriptor. 2623 * Called on close. 2624 */ 2625 static void 2626 bpfd_free(epoch_context_t ctx) 2627 { 2628 struct bpf_d *d; 2629 struct bpf_program_buffer *p; 2630 2631 /* 2632 * We don't need to lock out interrupts since this descriptor has 2633 * been detached from its interface and it yet hasn't been marked 2634 * free. 2635 */ 2636 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2637 bpf_free(d); 2638 if (d->bd_rfilter != NULL) { 2639 p = __containerof((void *)d->bd_rfilter, 2640 struct bpf_program_buffer, buffer); 2641 #ifdef BPF_JITTER 2642 p->func = d->bd_bfilter; 2643 #endif 2644 bpf_program_buffer_free(&p->epoch_ctx); 2645 } 2646 if (d->bd_wfilter != NULL) { 2647 p = __containerof((void *)d->bd_wfilter, 2648 struct bpf_program_buffer, buffer); 2649 #ifdef BPF_JITTER 2650 p->func = NULL; 2651 #endif 2652 bpf_program_buffer_free(&p->epoch_ctx); 2653 } 2654 2655 mtx_destroy(&d->bd_lock); 2656 counter_u64_free(d->bd_rcount); 2657 counter_u64_free(d->bd_dcount); 2658 counter_u64_free(d->bd_fcount); 2659 counter_u64_free(d->bd_wcount); 2660 counter_u64_free(d->bd_wfcount); 2661 counter_u64_free(d->bd_wdcount); 2662 counter_u64_free(d->bd_zcopy); 2663 free(d, M_BPF); 2664 } 2665 2666 /* 2667 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2668 * fixed size of the link header (variable length headers not yet supported). 2669 */ 2670 void 2671 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2672 { 2673 2674 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2675 } 2676 2677 /* 2678 * Attach an interface to bpf. ifp is a pointer to the structure 2679 * defining the interface to be attached, dlt is the link layer type, 2680 * and hdrlen is the fixed size of the link header (variable length 2681 * headers are not yet supporrted). 2682 */ 2683 void 2684 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, 2685 struct bpf_if **driverp) 2686 { 2687 struct bpf_if *bp; 2688 2689 KASSERT(*driverp == NULL, 2690 ("bpfattach2: driverp already initialized")); 2691 2692 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2693 2694 CK_LIST_INIT(&bp->bif_dlist); 2695 CK_LIST_INIT(&bp->bif_wlist); 2696 bp->bif_ifp = ifp; 2697 bp->bif_dlt = dlt; 2698 bp->bif_hdrlen = hdrlen; 2699 bp->bif_bpf = driverp; 2700 bp->bif_refcnt = 1; 2701 *driverp = bp; 2702 /* 2703 * Reference ifnet pointer, so it won't freed until 2704 * we release it. 2705 */ 2706 if_ref(ifp); 2707 BPF_LOCK(); 2708 CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2709 BPF_UNLOCK(); 2710 2711 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2712 if_printf(ifp, "bpf attached\n"); 2713 } 2714 2715 #ifdef VIMAGE 2716 /* 2717 * When moving interfaces between vnet instances we need a way to 2718 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2719 * after the vmove. We unfortunately have no device driver infrastructure 2720 * to query the interface for these values after creation/attach, thus 2721 * add this as a workaround. 2722 */ 2723 int 2724 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2725 { 2726 2727 if (bp == NULL) 2728 return (ENXIO); 2729 if (bif_dlt == NULL && bif_hdrlen == NULL) 2730 return (0); 2731 2732 if (bif_dlt != NULL) 2733 *bif_dlt = bp->bif_dlt; 2734 if (bif_hdrlen != NULL) 2735 *bif_hdrlen = bp->bif_hdrlen; 2736 2737 return (0); 2738 } 2739 #endif 2740 2741 /* 2742 * Detach bpf from an interface. This involves detaching each descriptor 2743 * associated with the interface. Notify each descriptor as it's detached 2744 * so that any sleepers wake up and get ENXIO. 2745 */ 2746 void 2747 bpfdetach(struct ifnet *ifp) 2748 { 2749 struct bpf_if *bp, *bp_temp; 2750 struct bpf_d *d; 2751 2752 BPF_LOCK(); 2753 /* Find all bpf_if struct's which reference ifp and detach them. */ 2754 CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2755 if (ifp != bp->bif_ifp) 2756 continue; 2757 2758 CK_LIST_REMOVE(bp, bif_next); 2759 *bp->bif_bpf = (struct bpf_if *)&dead_bpf_if; 2760 2761 CTR4(KTR_NET, 2762 "%s: sheduling free for encap %d (%p) for if %p", 2763 __func__, bp->bif_dlt, bp, ifp); 2764 2765 /* Detach common descriptors */ 2766 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2767 bpf_detachd_locked(d, true); 2768 } 2769 2770 /* Detach writer-only descriptors */ 2771 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2772 bpf_detachd_locked(d, true); 2773 } 2774 bpfif_rele(bp); 2775 } 2776 BPF_UNLOCK(); 2777 } 2778 2779 /* 2780 * Get a list of available data link type of the interface. 2781 */ 2782 static int 2783 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2784 { 2785 struct ifnet *ifp; 2786 struct bpf_if *bp; 2787 u_int *lst; 2788 int error, n, n1; 2789 2790 BPF_LOCK_ASSERT(); 2791 2792 ifp = d->bd_bif->bif_ifp; 2793 n1 = 0; 2794 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2795 if (bp->bif_ifp == ifp) 2796 n1++; 2797 } 2798 if (bfl->bfl_list == NULL) { 2799 bfl->bfl_len = n1; 2800 return (0); 2801 } 2802 if (n1 > bfl->bfl_len) 2803 return (ENOMEM); 2804 2805 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2806 n = 0; 2807 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2808 if (bp->bif_ifp != ifp) 2809 continue; 2810 lst[n++] = bp->bif_dlt; 2811 } 2812 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2813 free(lst, M_TEMP); 2814 bfl->bfl_len = n; 2815 return (error); 2816 } 2817 2818 /* 2819 * Set the data link type of a BPF instance. 2820 */ 2821 static int 2822 bpf_setdlt(struct bpf_d *d, u_int dlt) 2823 { 2824 int error, opromisc; 2825 struct ifnet *ifp; 2826 struct bpf_if *bp; 2827 2828 BPF_LOCK_ASSERT(); 2829 MPASS(d->bd_bif != NULL); 2830 2831 /* 2832 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2833 * changed while we hold global lock. 2834 */ 2835 if (d->bd_bif->bif_dlt == dlt) 2836 return (0); 2837 2838 ifp = d->bd_bif->bif_ifp; 2839 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2840 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2841 break; 2842 } 2843 if (bp == NULL) 2844 return (EINVAL); 2845 2846 opromisc = d->bd_promisc; 2847 bpf_attachd(d, bp); 2848 if (opromisc) { 2849 error = ifpromisc(bp->bif_ifp, 1); 2850 if (error) 2851 if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", 2852 __func__, error); 2853 else 2854 d->bd_promisc = 1; 2855 } 2856 return (0); 2857 } 2858 2859 static void 2860 bpf_drvinit(void *unused) 2861 { 2862 struct cdev *dev; 2863 2864 sx_init(&bpf_sx, "bpf global lock"); 2865 CK_LIST_INIT(&bpf_iflist); 2866 2867 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2868 /* For compatibility */ 2869 make_dev_alias(dev, "bpf0"); 2870 } 2871 2872 /* 2873 * Zero out the various packet counters associated with all of the bpf 2874 * descriptors. At some point, we will probably want to get a bit more 2875 * granular and allow the user to specify descriptors to be zeroed. 2876 */ 2877 static void 2878 bpf_zero_counters(void) 2879 { 2880 struct bpf_if *bp; 2881 struct bpf_d *bd; 2882 2883 BPF_LOCK(); 2884 /* 2885 * We are protected by global lock here, interfaces and 2886 * descriptors can not be deleted while we hold it. 2887 */ 2888 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2889 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2890 counter_u64_zero(bd->bd_rcount); 2891 counter_u64_zero(bd->bd_dcount); 2892 counter_u64_zero(bd->bd_fcount); 2893 counter_u64_zero(bd->bd_wcount); 2894 counter_u64_zero(bd->bd_wfcount); 2895 counter_u64_zero(bd->bd_zcopy); 2896 } 2897 } 2898 BPF_UNLOCK(); 2899 } 2900 2901 /* 2902 * Fill filter statistics 2903 */ 2904 static void 2905 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2906 { 2907 2908 BPF_LOCK_ASSERT(); 2909 bzero(d, sizeof(*d)); 2910 d->bd_structsize = sizeof(*d); 2911 d->bd_immediate = bd->bd_immediate; 2912 d->bd_promisc = bd->bd_promisc; 2913 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2914 d->bd_direction = bd->bd_direction; 2915 d->bd_feedback = bd->bd_feedback; 2916 d->bd_async = bd->bd_async; 2917 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2918 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2919 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2920 d->bd_sig = bd->bd_sig; 2921 d->bd_slen = bd->bd_slen; 2922 d->bd_hlen = bd->bd_hlen; 2923 d->bd_bufsize = bd->bd_bufsize; 2924 d->bd_pid = bd->bd_pid; 2925 strlcpy(d->bd_ifname, 2926 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2927 d->bd_locked = bd->bd_locked; 2928 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2929 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2930 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2931 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2932 d->bd_bufmode = bd->bd_bufmode; 2933 } 2934 2935 /* 2936 * Handle `netstat -B' stats request 2937 */ 2938 static int 2939 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2940 { 2941 static const struct xbpf_d zerostats; 2942 struct xbpf_d *xbdbuf, *xbd, tempstats; 2943 int index, error; 2944 struct bpf_if *bp; 2945 struct bpf_d *bd; 2946 2947 /* 2948 * XXX This is not technically correct. It is possible for non 2949 * privileged users to open bpf devices. It would make sense 2950 * if the users who opened the devices were able to retrieve 2951 * the statistics for them, too. 2952 */ 2953 error = priv_check(req->td, PRIV_NET_BPF); 2954 if (error) 2955 return (error); 2956 /* 2957 * Check to see if the user is requesting that the counters be 2958 * zeroed out. Explicitly check that the supplied data is zeroed, 2959 * as we aren't allowing the user to set the counters currently. 2960 */ 2961 if (req->newptr != NULL) { 2962 if (req->newlen != sizeof(tempstats)) 2963 return (EINVAL); 2964 memset(&tempstats, 0, sizeof(tempstats)); 2965 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2966 if (error) 2967 return (error); 2968 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2969 return (EINVAL); 2970 bpf_zero_counters(); 2971 return (0); 2972 } 2973 if (req->oldptr == NULL) 2974 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2975 if (bpf_bpfd_cnt == 0) 2976 return (SYSCTL_OUT(req, 0, 0)); 2977 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2978 BPF_LOCK(); 2979 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2980 BPF_UNLOCK(); 2981 free(xbdbuf, M_BPF); 2982 return (ENOMEM); 2983 } 2984 index = 0; 2985 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2986 /* Send writers-only first */ 2987 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2988 xbd = &xbdbuf[index++]; 2989 bpfstats_fill_xbpf(xbd, bd); 2990 } 2991 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2992 xbd = &xbdbuf[index++]; 2993 bpfstats_fill_xbpf(xbd, bd); 2994 } 2995 } 2996 BPF_UNLOCK(); 2997 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2998 free(xbdbuf, M_BPF); 2999 return (error); 3000 } 3001 3002 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 3003 3004 #else /* !DEV_BPF && !NETGRAPH_BPF */ 3005 3006 /* 3007 * NOP stubs to allow bpf-using drivers to load and function. 3008 * 3009 * A 'better' implementation would allow the core bpf functionality 3010 * to be loaded at runtime. 3011 */ 3012 3013 void 3014 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3015 { 3016 } 3017 3018 void 3019 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3020 { 3021 } 3022 3023 void 3024 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3025 { 3026 } 3027 3028 void 3029 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3030 { 3031 3032 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3033 } 3034 3035 void 3036 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3037 { 3038 3039 *driverp = (struct bpf_if *)&dead_bpf_if; 3040 } 3041 3042 void 3043 bpfdetach(struct ifnet *ifp) 3044 { 3045 } 3046 3047 u_int 3048 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3049 { 3050 return -1; /* "no filter" behaviour */ 3051 } 3052 3053 int 3054 bpf_validate(const struct bpf_insn *f, int len) 3055 { 3056 return 0; /* false */ 3057 } 3058 3059 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3060 3061 #ifdef DDB 3062 static void 3063 bpf_show_bpf_if(struct bpf_if *bpf_if) 3064 { 3065 3066 if (bpf_if == NULL) 3067 return; 3068 db_printf("%p:\n", bpf_if); 3069 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3070 /* bif_ext.bif_next */ 3071 /* bif_ext.bif_dlist */ 3072 BPF_DB_PRINTF("%#x", bif_dlt); 3073 BPF_DB_PRINTF("%u", bif_hdrlen); 3074 /* bif_wlist */ 3075 BPF_DB_PRINTF("%p", bif_ifp); 3076 BPF_DB_PRINTF("%p", bif_bpf); 3077 BPF_DB_PRINTF("%u", bif_refcnt); 3078 } 3079 3080 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3081 { 3082 3083 if (!have_addr) { 3084 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3085 return; 3086 } 3087 3088 bpf_show_bpf_if((struct bpf_if *)addr); 3089 } 3090 #endif 3091