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 | CTLFLAG_MPSAFE, 0, 218 "bpf sysctl"); 219 int bpf_maxinsns = BPF_MAXINSNS; 220 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 221 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 222 static int bpf_zerocopy_enable = 0; 223 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 224 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 225 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 226 bpf_stats_sysctl, "bpf statistics portal"); 227 228 VNET_DEFINE_STATIC(int, bpf_optimize_writers) = 0; 229 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 230 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RWTUN, 231 &VNET_NAME(bpf_optimize_writers), 0, 232 "Do not send packets until BPF program is set"); 233 234 static d_open_t bpfopen; 235 static d_read_t bpfread; 236 static d_write_t bpfwrite; 237 static d_ioctl_t bpfioctl; 238 static d_poll_t bpfpoll; 239 static d_kqfilter_t bpfkqfilter; 240 241 static struct cdevsw bpf_cdevsw = { 242 .d_version = D_VERSION, 243 .d_open = bpfopen, 244 .d_read = bpfread, 245 .d_write = bpfwrite, 246 .d_ioctl = bpfioctl, 247 .d_poll = bpfpoll, 248 .d_name = "bpf", 249 .d_kqfilter = bpfkqfilter, 250 }; 251 252 static struct filterops bpfread_filtops = { 253 .f_isfd = 1, 254 .f_detach = filt_bpfdetach, 255 .f_event = filt_bpfread, 256 }; 257 258 /* 259 * LOCKING MODEL USED BY BPF 260 * 261 * Locks: 262 * 1) global lock (BPF_LOCK). Sx, used to protect some global counters, 263 * every bpf_iflist changes, serializes ioctl access to bpf descriptors. 264 * 2) Descriptor lock. Mutex, used to protect BPF buffers and various 265 * structure fields used by bpf_*tap* code. 266 * 267 * Lock order: global lock, then descriptor lock. 268 * 269 * There are several possible consumers: 270 * 271 * 1. The kernel registers interface pointer with bpfattach(). 272 * Each call allocates new bpf_if structure, references ifnet pointer 273 * and links bpf_if into bpf_iflist chain. This is protected with global 274 * lock. 275 * 276 * 2. An userland application uses ioctl() call to bpf_d descriptor. 277 * All such call are serialized with global lock. BPF filters can be 278 * changed, but pointer to old filter will be freed using NET_EPOCH_CALL(). 279 * Thus it should be safe for bpf_tap/bpf_mtap* code to do access to 280 * filter pointers, even if change will happen during bpf_tap execution. 281 * Destroying of bpf_d descriptor also is doing using NET_EPOCH_CALL(). 282 * 283 * 3. An userland application can write packets into bpf_d descriptor. 284 * There we need to be sure, that ifnet won't disappear during bpfwrite(). 285 * 286 * 4. The kernel invokes bpf_tap/bpf_mtap* functions. The access to 287 * bif_dlist is protected with net_epoch_preempt section. So, it should 288 * be safe to make access to bpf_d descriptor inside the section. 289 * 290 * 5. The kernel invokes bpfdetach() on interface destroying. All lists 291 * are modified with global lock held and actual free() is done using 292 * NET_EPOCH_CALL(). 293 */ 294 295 static void 296 bpfif_free(epoch_context_t ctx) 297 { 298 struct bpf_if *bp; 299 300 bp = __containerof(ctx, struct bpf_if, epoch_ctx); 301 if_rele(bp->bif_ifp); 302 free(bp, M_BPF); 303 } 304 305 static void 306 bpfif_ref(struct bpf_if *bp) 307 { 308 309 refcount_acquire(&bp->bif_refcnt); 310 } 311 312 static void 313 bpfif_rele(struct bpf_if *bp) 314 { 315 316 if (!refcount_release(&bp->bif_refcnt)) 317 return; 318 NET_EPOCH_CALL(bpfif_free, &bp->epoch_ctx); 319 } 320 321 static void 322 bpfd_ref(struct bpf_d *d) 323 { 324 325 refcount_acquire(&d->bd_refcnt); 326 } 327 328 static void 329 bpfd_rele(struct bpf_d *d) 330 { 331 332 if (!refcount_release(&d->bd_refcnt)) 333 return; 334 NET_EPOCH_CALL(bpfd_free, &d->epoch_ctx); 335 } 336 337 static struct bpf_program_buffer* 338 bpf_program_buffer_alloc(size_t size, int flags) 339 { 340 341 return (malloc(sizeof(struct bpf_program_buffer) + size, 342 M_BPF, flags)); 343 } 344 345 static void 346 bpf_program_buffer_free(epoch_context_t ctx) 347 { 348 struct bpf_program_buffer *ptr; 349 350 ptr = __containerof(ctx, struct bpf_program_buffer, epoch_ctx); 351 #ifdef BPF_JITTER 352 if (ptr->func != NULL) 353 bpf_destroy_jit_filter(ptr->func); 354 #endif 355 free(ptr, M_BPF); 356 } 357 358 /* 359 * Wrapper functions for various buffering methods. If the set of buffer 360 * modes expands, we will probably want to introduce a switch data structure 361 * similar to protosw, et. 362 */ 363 static void 364 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 365 u_int len) 366 { 367 368 BPFD_LOCK_ASSERT(d); 369 370 switch (d->bd_bufmode) { 371 case BPF_BUFMODE_BUFFER: 372 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 373 374 case BPF_BUFMODE_ZBUF: 375 counter_u64_add(d->bd_zcopy, 1); 376 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 377 378 default: 379 panic("bpf_buf_append_bytes"); 380 } 381 } 382 383 static void 384 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 385 u_int len) 386 { 387 388 BPFD_LOCK_ASSERT(d); 389 390 switch (d->bd_bufmode) { 391 case BPF_BUFMODE_BUFFER: 392 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 393 394 case BPF_BUFMODE_ZBUF: 395 counter_u64_add(d->bd_zcopy, 1); 396 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 397 398 default: 399 panic("bpf_buf_append_mbuf"); 400 } 401 } 402 403 /* 404 * This function gets called when the free buffer is re-assigned. 405 */ 406 static void 407 bpf_buf_reclaimed(struct bpf_d *d) 408 { 409 410 BPFD_LOCK_ASSERT(d); 411 412 switch (d->bd_bufmode) { 413 case BPF_BUFMODE_BUFFER: 414 return; 415 416 case BPF_BUFMODE_ZBUF: 417 bpf_zerocopy_buf_reclaimed(d); 418 return; 419 420 default: 421 panic("bpf_buf_reclaimed"); 422 } 423 } 424 425 /* 426 * If the buffer mechanism has a way to decide that a held buffer can be made 427 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 428 * returned if the buffer can be discarded, (0) is returned if it cannot. 429 */ 430 static int 431 bpf_canfreebuf(struct bpf_d *d) 432 { 433 434 BPFD_LOCK_ASSERT(d); 435 436 switch (d->bd_bufmode) { 437 case BPF_BUFMODE_ZBUF: 438 return (bpf_zerocopy_canfreebuf(d)); 439 } 440 return (0); 441 } 442 443 /* 444 * Allow the buffer model to indicate that the current store buffer is 445 * immutable, regardless of the appearance of space. Return (1) if the 446 * buffer is writable, and (0) if not. 447 */ 448 static int 449 bpf_canwritebuf(struct bpf_d *d) 450 { 451 BPFD_LOCK_ASSERT(d); 452 453 switch (d->bd_bufmode) { 454 case BPF_BUFMODE_ZBUF: 455 return (bpf_zerocopy_canwritebuf(d)); 456 } 457 return (1); 458 } 459 460 /* 461 * Notify buffer model that an attempt to write to the store buffer has 462 * resulted in a dropped packet, in which case the buffer may be considered 463 * full. 464 */ 465 static void 466 bpf_buffull(struct bpf_d *d) 467 { 468 469 BPFD_LOCK_ASSERT(d); 470 471 switch (d->bd_bufmode) { 472 case BPF_BUFMODE_ZBUF: 473 bpf_zerocopy_buffull(d); 474 break; 475 } 476 } 477 478 /* 479 * Notify the buffer model that a buffer has moved into the hold position. 480 */ 481 void 482 bpf_bufheld(struct bpf_d *d) 483 { 484 485 BPFD_LOCK_ASSERT(d); 486 487 switch (d->bd_bufmode) { 488 case BPF_BUFMODE_ZBUF: 489 bpf_zerocopy_bufheld(d); 490 break; 491 } 492 } 493 494 static void 495 bpf_free(struct bpf_d *d) 496 { 497 498 switch (d->bd_bufmode) { 499 case BPF_BUFMODE_BUFFER: 500 return (bpf_buffer_free(d)); 501 502 case BPF_BUFMODE_ZBUF: 503 return (bpf_zerocopy_free(d)); 504 505 default: 506 panic("bpf_buf_free"); 507 } 508 } 509 510 static int 511 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 512 { 513 514 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 515 return (EOPNOTSUPP); 516 return (bpf_buffer_uiomove(d, buf, len, uio)); 517 } 518 519 static int 520 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 521 { 522 523 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 524 return (EOPNOTSUPP); 525 return (bpf_buffer_ioctl_sblen(d, i)); 526 } 527 528 static int 529 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 530 { 531 532 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 533 return (EOPNOTSUPP); 534 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 535 } 536 537 static int 538 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 539 { 540 541 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 542 return (EOPNOTSUPP); 543 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 544 } 545 546 static int 547 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 548 { 549 550 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 551 return (EOPNOTSUPP); 552 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 553 } 554 555 /* 556 * General BPF functions. 557 */ 558 static int 559 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 560 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) 561 { 562 const struct ieee80211_bpf_params *p; 563 struct ether_header *eh; 564 struct mbuf *m; 565 int error; 566 int len; 567 int hlen; 568 int slen; 569 570 /* 571 * Build a sockaddr based on the data link layer type. 572 * We do this at this level because the ethernet header 573 * is copied directly into the data field of the sockaddr. 574 * In the case of SLIP, there is no header and the packet 575 * is forwarded as is. 576 * Also, we are careful to leave room at the front of the mbuf 577 * for the link level header. 578 */ 579 switch (linktype) { 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 default: 1431 error = EINVAL; 1432 break; 1433 1434 /* 1435 * Check for read packet available. 1436 */ 1437 case FIONREAD: 1438 { 1439 int n; 1440 1441 BPFD_LOCK(d); 1442 n = d->bd_slen; 1443 while (d->bd_hbuf_in_use) 1444 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1445 PRINET, "bd_hbuf", 0); 1446 if (d->bd_hbuf) 1447 n += d->bd_hlen; 1448 BPFD_UNLOCK(d); 1449 1450 *(int *)addr = n; 1451 break; 1452 } 1453 1454 /* 1455 * Get buffer len [for read()]. 1456 */ 1457 case BIOCGBLEN: 1458 BPFD_LOCK(d); 1459 *(u_int *)addr = d->bd_bufsize; 1460 BPFD_UNLOCK(d); 1461 break; 1462 1463 /* 1464 * Set buffer length. 1465 */ 1466 case BIOCSBLEN: 1467 error = bpf_ioctl_sblen(d, (u_int *)addr); 1468 break; 1469 1470 /* 1471 * Set link layer read filter. 1472 */ 1473 case BIOCSETF: 1474 case BIOCSETFNR: 1475 case BIOCSETWF: 1476 #ifdef COMPAT_FREEBSD32 1477 case BIOCSETF32: 1478 case BIOCSETFNR32: 1479 case BIOCSETWF32: 1480 #endif 1481 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1482 break; 1483 1484 /* 1485 * Flush read packet buffer. 1486 */ 1487 case BIOCFLUSH: 1488 BPFD_LOCK(d); 1489 reset_d(d); 1490 BPFD_UNLOCK(d); 1491 break; 1492 1493 /* 1494 * Put interface into promiscuous mode. 1495 */ 1496 case BIOCPROMISC: 1497 if (d->bd_bif == NULL) { 1498 /* 1499 * No interface attached yet. 1500 */ 1501 error = EINVAL; 1502 break; 1503 } 1504 if (d->bd_promisc == 0) { 1505 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1506 if (error == 0) 1507 d->bd_promisc = 1; 1508 } 1509 break; 1510 1511 /* 1512 * Get current data link type. 1513 */ 1514 case BIOCGDLT: 1515 BPF_LOCK(); 1516 if (d->bd_bif == NULL) 1517 error = EINVAL; 1518 else 1519 *(u_int *)addr = d->bd_bif->bif_dlt; 1520 BPF_UNLOCK(); 1521 break; 1522 1523 /* 1524 * Get a list of supported data link types. 1525 */ 1526 #ifdef COMPAT_FREEBSD32 1527 case BIOCGDLTLIST32: 1528 { 1529 struct bpf_dltlist32 *list32; 1530 struct bpf_dltlist dltlist; 1531 1532 list32 = (struct bpf_dltlist32 *)addr; 1533 dltlist.bfl_len = list32->bfl_len; 1534 dltlist.bfl_list = PTRIN(list32->bfl_list); 1535 BPF_LOCK(); 1536 if (d->bd_bif == NULL) 1537 error = EINVAL; 1538 else { 1539 error = bpf_getdltlist(d, &dltlist); 1540 if (error == 0) 1541 list32->bfl_len = dltlist.bfl_len; 1542 } 1543 BPF_UNLOCK(); 1544 break; 1545 } 1546 #endif 1547 1548 case BIOCGDLTLIST: 1549 BPF_LOCK(); 1550 if (d->bd_bif == NULL) 1551 error = EINVAL; 1552 else 1553 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1554 BPF_UNLOCK(); 1555 break; 1556 1557 /* 1558 * Set data link type. 1559 */ 1560 case BIOCSDLT: 1561 BPF_LOCK(); 1562 if (d->bd_bif == NULL) 1563 error = EINVAL; 1564 else 1565 error = bpf_setdlt(d, *(u_int *)addr); 1566 BPF_UNLOCK(); 1567 break; 1568 1569 /* 1570 * Get interface name. 1571 */ 1572 case BIOCGETIF: 1573 BPF_LOCK(); 1574 if (d->bd_bif == NULL) 1575 error = EINVAL; 1576 else { 1577 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1578 struct ifreq *const ifr = (struct ifreq *)addr; 1579 1580 strlcpy(ifr->ifr_name, ifp->if_xname, 1581 sizeof(ifr->ifr_name)); 1582 } 1583 BPF_UNLOCK(); 1584 break; 1585 1586 /* 1587 * Set interface. 1588 */ 1589 case BIOCSETIF: 1590 { 1591 int alloc_buf, size; 1592 1593 /* 1594 * Behavior here depends on the buffering model. If 1595 * we're using kernel memory buffers, then we can 1596 * allocate them here. If we're using zero-copy, 1597 * then the user process must have registered buffers 1598 * by the time we get here. 1599 */ 1600 alloc_buf = 0; 1601 BPFD_LOCK(d); 1602 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1603 d->bd_sbuf == NULL) 1604 alloc_buf = 1; 1605 BPFD_UNLOCK(d); 1606 if (alloc_buf) { 1607 size = d->bd_bufsize; 1608 error = bpf_buffer_ioctl_sblen(d, &size); 1609 if (error != 0) 1610 break; 1611 } 1612 BPF_LOCK(); 1613 error = bpf_setif(d, (struct ifreq *)addr); 1614 BPF_UNLOCK(); 1615 break; 1616 } 1617 1618 /* 1619 * Set read timeout. 1620 */ 1621 case BIOCSRTIMEOUT: 1622 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1623 case BIOCSRTIMEOUT32: 1624 #endif 1625 { 1626 struct timeval *tv = (struct timeval *)addr; 1627 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1628 struct timeval32 *tv32; 1629 struct timeval tv64; 1630 1631 if (cmd == BIOCSRTIMEOUT32) { 1632 tv32 = (struct timeval32 *)addr; 1633 tv = &tv64; 1634 tv->tv_sec = tv32->tv_sec; 1635 tv->tv_usec = tv32->tv_usec; 1636 } else 1637 #endif 1638 tv = (struct timeval *)addr; 1639 1640 /* 1641 * Subtract 1 tick from tvtohz() since this isn't 1642 * a one-shot timer. 1643 */ 1644 if ((error = itimerfix(tv)) == 0) 1645 d->bd_rtout = tvtohz(tv) - 1; 1646 break; 1647 } 1648 1649 /* 1650 * Get read timeout. 1651 */ 1652 case BIOCGRTIMEOUT: 1653 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1654 case BIOCGRTIMEOUT32: 1655 #endif 1656 { 1657 struct timeval *tv; 1658 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1659 struct timeval32 *tv32; 1660 struct timeval tv64; 1661 1662 if (cmd == BIOCGRTIMEOUT32) 1663 tv = &tv64; 1664 else 1665 #endif 1666 tv = (struct timeval *)addr; 1667 1668 tv->tv_sec = d->bd_rtout / hz; 1669 tv->tv_usec = (d->bd_rtout % hz) * tick; 1670 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1671 if (cmd == BIOCGRTIMEOUT32) { 1672 tv32 = (struct timeval32 *)addr; 1673 tv32->tv_sec = tv->tv_sec; 1674 tv32->tv_usec = tv->tv_usec; 1675 } 1676 #endif 1677 1678 break; 1679 } 1680 1681 /* 1682 * Get packet stats. 1683 */ 1684 case BIOCGSTATS: 1685 { 1686 struct bpf_stat *bs = (struct bpf_stat *)addr; 1687 1688 /* XXXCSJP overflow */ 1689 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1690 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1691 break; 1692 } 1693 1694 /* 1695 * Set immediate mode. 1696 */ 1697 case BIOCIMMEDIATE: 1698 BPFD_LOCK(d); 1699 d->bd_immediate = *(u_int *)addr; 1700 BPFD_UNLOCK(d); 1701 break; 1702 1703 case BIOCVERSION: 1704 { 1705 struct bpf_version *bv = (struct bpf_version *)addr; 1706 1707 bv->bv_major = BPF_MAJOR_VERSION; 1708 bv->bv_minor = BPF_MINOR_VERSION; 1709 break; 1710 } 1711 1712 /* 1713 * Get "header already complete" flag 1714 */ 1715 case BIOCGHDRCMPLT: 1716 BPFD_LOCK(d); 1717 *(u_int *)addr = d->bd_hdrcmplt; 1718 BPFD_UNLOCK(d); 1719 break; 1720 1721 /* 1722 * Set "header already complete" flag 1723 */ 1724 case BIOCSHDRCMPLT: 1725 BPFD_LOCK(d); 1726 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1727 BPFD_UNLOCK(d); 1728 break; 1729 1730 /* 1731 * Get packet direction flag 1732 */ 1733 case BIOCGDIRECTION: 1734 BPFD_LOCK(d); 1735 *(u_int *)addr = d->bd_direction; 1736 BPFD_UNLOCK(d); 1737 break; 1738 1739 /* 1740 * Set packet direction flag 1741 */ 1742 case BIOCSDIRECTION: 1743 { 1744 u_int direction; 1745 1746 direction = *(u_int *)addr; 1747 switch (direction) { 1748 case BPF_D_IN: 1749 case BPF_D_INOUT: 1750 case BPF_D_OUT: 1751 BPFD_LOCK(d); 1752 d->bd_direction = direction; 1753 BPFD_UNLOCK(d); 1754 break; 1755 default: 1756 error = EINVAL; 1757 } 1758 } 1759 break; 1760 1761 /* 1762 * Get packet timestamp format and resolution. 1763 */ 1764 case BIOCGTSTAMP: 1765 BPFD_LOCK(d); 1766 *(u_int *)addr = d->bd_tstamp; 1767 BPFD_UNLOCK(d); 1768 break; 1769 1770 /* 1771 * Set packet timestamp format and resolution. 1772 */ 1773 case BIOCSTSTAMP: 1774 { 1775 u_int func; 1776 1777 func = *(u_int *)addr; 1778 if (BPF_T_VALID(func)) 1779 d->bd_tstamp = func; 1780 else 1781 error = EINVAL; 1782 } 1783 break; 1784 1785 case BIOCFEEDBACK: 1786 BPFD_LOCK(d); 1787 d->bd_feedback = *(u_int *)addr; 1788 BPFD_UNLOCK(d); 1789 break; 1790 1791 case BIOCLOCK: 1792 BPFD_LOCK(d); 1793 d->bd_locked = 1; 1794 BPFD_UNLOCK(d); 1795 break; 1796 1797 case FIONBIO: /* Non-blocking I/O */ 1798 break; 1799 1800 case FIOASYNC: /* Send signal on receive packets */ 1801 BPFD_LOCK(d); 1802 d->bd_async = *(int *)addr; 1803 BPFD_UNLOCK(d); 1804 break; 1805 1806 case FIOSETOWN: 1807 /* 1808 * XXX: Add some sort of locking here? 1809 * fsetown() can sleep. 1810 */ 1811 error = fsetown(*(int *)addr, &d->bd_sigio); 1812 break; 1813 1814 case FIOGETOWN: 1815 BPFD_LOCK(d); 1816 *(int *)addr = fgetown(&d->bd_sigio); 1817 BPFD_UNLOCK(d); 1818 break; 1819 1820 /* This is deprecated, FIOSETOWN should be used instead. */ 1821 case TIOCSPGRP: 1822 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1823 break; 1824 1825 /* This is deprecated, FIOGETOWN should be used instead. */ 1826 case TIOCGPGRP: 1827 *(int *)addr = -fgetown(&d->bd_sigio); 1828 break; 1829 1830 case BIOCSRSIG: /* Set receive signal */ 1831 { 1832 u_int sig; 1833 1834 sig = *(u_int *)addr; 1835 1836 if (sig >= NSIG) 1837 error = EINVAL; 1838 else { 1839 BPFD_LOCK(d); 1840 d->bd_sig = sig; 1841 BPFD_UNLOCK(d); 1842 } 1843 break; 1844 } 1845 case BIOCGRSIG: 1846 BPFD_LOCK(d); 1847 *(u_int *)addr = d->bd_sig; 1848 BPFD_UNLOCK(d); 1849 break; 1850 1851 case BIOCGETBUFMODE: 1852 BPFD_LOCK(d); 1853 *(u_int *)addr = d->bd_bufmode; 1854 BPFD_UNLOCK(d); 1855 break; 1856 1857 case BIOCSETBUFMODE: 1858 /* 1859 * Allow the buffering mode to be changed as long as we 1860 * haven't yet committed to a particular mode. Our 1861 * definition of commitment, for now, is whether or not a 1862 * buffer has been allocated or an interface attached, since 1863 * that's the point where things get tricky. 1864 */ 1865 switch (*(u_int *)addr) { 1866 case BPF_BUFMODE_BUFFER: 1867 break; 1868 1869 case BPF_BUFMODE_ZBUF: 1870 if (bpf_zerocopy_enable) 1871 break; 1872 /* FALLSTHROUGH */ 1873 1874 default: 1875 CURVNET_RESTORE(); 1876 return (EINVAL); 1877 } 1878 1879 BPFD_LOCK(d); 1880 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1881 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1882 BPFD_UNLOCK(d); 1883 CURVNET_RESTORE(); 1884 return (EBUSY); 1885 } 1886 d->bd_bufmode = *(u_int *)addr; 1887 BPFD_UNLOCK(d); 1888 break; 1889 1890 case BIOCGETZMAX: 1891 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1892 break; 1893 1894 case BIOCSETZBUF: 1895 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1896 break; 1897 1898 case BIOCROTZBUF: 1899 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1900 break; 1901 } 1902 CURVNET_RESTORE(); 1903 return (error); 1904 } 1905 1906 /* 1907 * Set d's packet filter program to fp. If this file already has a filter, 1908 * free it and replace it. Returns EINVAL for bogus requests. 1909 * 1910 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1911 * calls. 1912 */ 1913 static int 1914 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1915 { 1916 #ifdef COMPAT_FREEBSD32 1917 struct bpf_program fp_swab; 1918 struct bpf_program32 *fp32; 1919 #endif 1920 struct bpf_program_buffer *fcode; 1921 struct bpf_insn *filter; 1922 #ifdef BPF_JITTER 1923 bpf_jit_filter *jfunc; 1924 #endif 1925 size_t size; 1926 u_int flen; 1927 bool track_event; 1928 1929 #ifdef COMPAT_FREEBSD32 1930 switch (cmd) { 1931 case BIOCSETF32: 1932 case BIOCSETWF32: 1933 case BIOCSETFNR32: 1934 fp32 = (struct bpf_program32 *)fp; 1935 fp_swab.bf_len = fp32->bf_len; 1936 fp_swab.bf_insns = 1937 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1938 fp = &fp_swab; 1939 switch (cmd) { 1940 case BIOCSETF32: 1941 cmd = BIOCSETF; 1942 break; 1943 case BIOCSETWF32: 1944 cmd = BIOCSETWF; 1945 break; 1946 } 1947 break; 1948 } 1949 #endif 1950 1951 filter = NULL; 1952 #ifdef BPF_JITTER 1953 jfunc = NULL; 1954 #endif 1955 /* 1956 * Check new filter validness before acquiring any locks. 1957 * Allocate memory for new filter, if needed. 1958 */ 1959 flen = fp->bf_len; 1960 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1961 return (EINVAL); 1962 size = flen * sizeof(*fp->bf_insns); 1963 if (size > 0) { 1964 /* We're setting up new filter. Copy and check actual data. */ 1965 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1966 filter = (struct bpf_insn *)fcode->buffer; 1967 if (copyin(fp->bf_insns, filter, size) != 0 || 1968 !bpf_validate(filter, flen)) { 1969 free(fcode, M_BPF); 1970 return (EINVAL); 1971 } 1972 #ifdef BPF_JITTER 1973 if (cmd != BIOCSETWF) { 1974 /* 1975 * Filter is copied inside fcode and is 1976 * perfectly valid. 1977 */ 1978 jfunc = bpf_jitter(filter, flen); 1979 } 1980 #endif 1981 } 1982 1983 track_event = false; 1984 fcode = NULL; 1985 1986 BPF_LOCK(); 1987 BPFD_LOCK(d); 1988 /* Set up new filter. */ 1989 if (cmd == BIOCSETWF) { 1990 if (d->bd_wfilter != NULL) { 1991 fcode = __containerof((void *)d->bd_wfilter, 1992 struct bpf_program_buffer, buffer); 1993 #ifdef BPF_JITTER 1994 fcode->func = NULL; 1995 #endif 1996 } 1997 d->bd_wfilter = filter; 1998 } else { 1999 if (d->bd_rfilter != NULL) { 2000 fcode = __containerof((void *)d->bd_rfilter, 2001 struct bpf_program_buffer, buffer); 2002 #ifdef BPF_JITTER 2003 fcode->func = d->bd_bfilter; 2004 #endif 2005 } 2006 d->bd_rfilter = filter; 2007 #ifdef BPF_JITTER 2008 d->bd_bfilter = jfunc; 2009 #endif 2010 if (cmd == BIOCSETF) 2011 reset_d(d); 2012 2013 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 2014 /* 2015 * Filter can be set several times without 2016 * specifying interface. In this case just mark d 2017 * as reader. 2018 */ 2019 d->bd_writer = 0; 2020 if (d->bd_bif != NULL) { 2021 /* 2022 * Remove descriptor from writers-only list 2023 * and add it to active readers list. 2024 */ 2025 CK_LIST_REMOVE(d, bd_next); 2026 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 2027 d, bd_next); 2028 CTR2(KTR_NET, 2029 "%s: upgrade required by pid %d", 2030 __func__, d->bd_pid); 2031 track_event = true; 2032 } 2033 } 2034 } 2035 BPFD_UNLOCK(d); 2036 2037 if (fcode != NULL) 2038 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 2039 2040 if (track_event) 2041 EVENTHANDLER_INVOKE(bpf_track, 2042 d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); 2043 2044 BPF_UNLOCK(); 2045 return (0); 2046 } 2047 2048 /* 2049 * Detach a file from its current interface (if attached at all) and attach 2050 * to the interface indicated by the name stored in ifr. 2051 * Return an errno or 0. 2052 */ 2053 static int 2054 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 2055 { 2056 struct bpf_if *bp; 2057 struct ifnet *theywant; 2058 2059 BPF_LOCK_ASSERT(); 2060 2061 theywant = ifunit(ifr->ifr_name); 2062 if (theywant == NULL || theywant->if_bpf == NULL) 2063 return (ENXIO); 2064 2065 bp = theywant->if_bpf; 2066 /* 2067 * At this point, we expect the buffer is already allocated. If not, 2068 * return an error. 2069 */ 2070 switch (d->bd_bufmode) { 2071 case BPF_BUFMODE_BUFFER: 2072 case BPF_BUFMODE_ZBUF: 2073 if (d->bd_sbuf == NULL) 2074 return (EINVAL); 2075 break; 2076 2077 default: 2078 panic("bpf_setif: bufmode %d", d->bd_bufmode); 2079 } 2080 if (bp != d->bd_bif) 2081 bpf_attachd(d, bp); 2082 else { 2083 BPFD_LOCK(d); 2084 reset_d(d); 2085 BPFD_UNLOCK(d); 2086 } 2087 return (0); 2088 } 2089 2090 /* 2091 * Support for select() and poll() system calls 2092 * 2093 * Return true iff the specific operation will not block indefinitely. 2094 * Otherwise, return false but make a note that a selwakeup() must be done. 2095 */ 2096 static int 2097 bpfpoll(struct cdev *dev, int events, struct thread *td) 2098 { 2099 struct bpf_d *d; 2100 int revents; 2101 2102 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2103 return (events & 2104 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 2105 2106 /* 2107 * Refresh PID associated with this descriptor. 2108 */ 2109 revents = events & (POLLOUT | POLLWRNORM); 2110 BPFD_LOCK(d); 2111 BPF_PID_REFRESH(d, td); 2112 if (events & (POLLIN | POLLRDNORM)) { 2113 if (bpf_ready(d)) 2114 revents |= events & (POLLIN | POLLRDNORM); 2115 else { 2116 selrecord(td, &d->bd_sel); 2117 /* Start the read timeout if necessary. */ 2118 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2119 callout_reset(&d->bd_callout, d->bd_rtout, 2120 bpf_timed_out, d); 2121 d->bd_state = BPF_WAITING; 2122 } 2123 } 2124 } 2125 BPFD_UNLOCK(d); 2126 return (revents); 2127 } 2128 2129 /* 2130 * Support for kevent() system call. Register EVFILT_READ filters and 2131 * reject all others. 2132 */ 2133 int 2134 bpfkqfilter(struct cdev *dev, struct knote *kn) 2135 { 2136 struct bpf_d *d; 2137 2138 if (devfs_get_cdevpriv((void **)&d) != 0 || 2139 kn->kn_filter != EVFILT_READ) 2140 return (1); 2141 2142 /* 2143 * Refresh PID associated with this descriptor. 2144 */ 2145 BPFD_LOCK(d); 2146 BPF_PID_REFRESH_CUR(d); 2147 kn->kn_fop = &bpfread_filtops; 2148 kn->kn_hook = d; 2149 knlist_add(&d->bd_sel.si_note, kn, 1); 2150 BPFD_UNLOCK(d); 2151 2152 return (0); 2153 } 2154 2155 static void 2156 filt_bpfdetach(struct knote *kn) 2157 { 2158 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2159 2160 knlist_remove(&d->bd_sel.si_note, kn, 0); 2161 } 2162 2163 static int 2164 filt_bpfread(struct knote *kn, long hint) 2165 { 2166 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2167 int ready; 2168 2169 BPFD_LOCK_ASSERT(d); 2170 ready = bpf_ready(d); 2171 if (ready) { 2172 kn->kn_data = d->bd_slen; 2173 /* 2174 * Ignore the hold buffer if it is being copied to user space. 2175 */ 2176 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2177 kn->kn_data += d->bd_hlen; 2178 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2179 callout_reset(&d->bd_callout, d->bd_rtout, 2180 bpf_timed_out, d); 2181 d->bd_state = BPF_WAITING; 2182 } 2183 2184 return (ready); 2185 } 2186 2187 #define BPF_TSTAMP_NONE 0 2188 #define BPF_TSTAMP_FAST 1 2189 #define BPF_TSTAMP_NORMAL 2 2190 #define BPF_TSTAMP_EXTERN 3 2191 2192 static int 2193 bpf_ts_quality(int tstype) 2194 { 2195 2196 if (tstype == BPF_T_NONE) 2197 return (BPF_TSTAMP_NONE); 2198 if ((tstype & BPF_T_FAST) != 0) 2199 return (BPF_TSTAMP_FAST); 2200 2201 return (BPF_TSTAMP_NORMAL); 2202 } 2203 2204 static int 2205 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2206 { 2207 struct m_tag *tag; 2208 int quality; 2209 2210 quality = bpf_ts_quality(tstype); 2211 if (quality == BPF_TSTAMP_NONE) 2212 return (quality); 2213 2214 if (m != NULL) { 2215 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2216 if (tag != NULL) { 2217 *bt = *(struct bintime *)(tag + 1); 2218 return (BPF_TSTAMP_EXTERN); 2219 } 2220 } 2221 if (quality == BPF_TSTAMP_NORMAL) 2222 binuptime(bt); 2223 else 2224 getbinuptime(bt); 2225 2226 return (quality); 2227 } 2228 2229 /* 2230 * Incoming linkage from device drivers. Process the packet pkt, of length 2231 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2232 * by each process' filter, and if accepted, stashed into the corresponding 2233 * buffer. 2234 */ 2235 void 2236 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2237 { 2238 struct epoch_tracker et; 2239 struct bintime bt; 2240 struct bpf_d *d; 2241 #ifdef BPF_JITTER 2242 bpf_jit_filter *bf; 2243 #endif 2244 u_int slen; 2245 int gottime; 2246 2247 gottime = BPF_TSTAMP_NONE; 2248 NET_EPOCH_ENTER(et); 2249 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2250 counter_u64_add(d->bd_rcount, 1); 2251 /* 2252 * NB: We dont call BPF_CHECK_DIRECTION() here since there 2253 * is no way for the caller to indiciate to us whether this 2254 * packet is inbound or outbound. In the bpf_mtap() routines, 2255 * we use the interface pointers on the mbuf to figure it out. 2256 */ 2257 #ifdef BPF_JITTER 2258 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2259 if (bf != NULL) 2260 slen = (*(bf->func))(pkt, pktlen, pktlen); 2261 else 2262 #endif 2263 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2264 if (slen != 0) { 2265 /* 2266 * Filter matches. Let's to acquire write lock. 2267 */ 2268 BPFD_LOCK(d); 2269 counter_u64_add(d->bd_fcount, 1); 2270 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2271 gottime = bpf_gettime(&bt, d->bd_tstamp, 2272 NULL); 2273 #ifdef MAC 2274 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2275 #endif 2276 catchpacket(d, pkt, pktlen, slen, 2277 bpf_append_bytes, &bt); 2278 BPFD_UNLOCK(d); 2279 } 2280 } 2281 NET_EPOCH_EXIT(et); 2282 } 2283 2284 #define BPF_CHECK_DIRECTION(d, r, i) \ 2285 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2286 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2287 2288 /* 2289 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2290 * Locking model is explained in bpf_tap(). 2291 */ 2292 void 2293 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2294 { 2295 struct epoch_tracker et; 2296 struct bintime bt; 2297 struct bpf_d *d; 2298 #ifdef BPF_JITTER 2299 bpf_jit_filter *bf; 2300 #endif 2301 u_int pktlen, slen; 2302 int gottime; 2303 2304 /* Skip outgoing duplicate packets. */ 2305 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2306 m->m_flags &= ~M_PROMISC; 2307 return; 2308 } 2309 2310 pktlen = m_length(m, NULL); 2311 gottime = BPF_TSTAMP_NONE; 2312 2313 NET_EPOCH_ENTER(et); 2314 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2315 if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) 2316 continue; 2317 counter_u64_add(d->bd_rcount, 1); 2318 #ifdef BPF_JITTER 2319 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2320 /* XXX We cannot handle multiple mbufs. */ 2321 if (bf != NULL && m->m_next == NULL) 2322 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2323 pktlen); 2324 else 2325 #endif 2326 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2327 if (slen != 0) { 2328 BPFD_LOCK(d); 2329 2330 counter_u64_add(d->bd_fcount, 1); 2331 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2332 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2333 #ifdef MAC 2334 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2335 #endif 2336 catchpacket(d, (u_char *)m, pktlen, slen, 2337 bpf_append_mbuf, &bt); 2338 BPFD_UNLOCK(d); 2339 } 2340 } 2341 NET_EPOCH_EXIT(et); 2342 } 2343 2344 /* 2345 * Incoming linkage from device drivers, when packet is in 2346 * an mbuf chain and to be prepended by a contiguous header. 2347 */ 2348 void 2349 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2350 { 2351 struct epoch_tracker et; 2352 struct bintime bt; 2353 struct mbuf mb; 2354 struct bpf_d *d; 2355 u_int pktlen, slen; 2356 int gottime; 2357 2358 /* Skip outgoing duplicate packets. */ 2359 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2360 m->m_flags &= ~M_PROMISC; 2361 return; 2362 } 2363 2364 pktlen = m_length(m, NULL); 2365 /* 2366 * Craft on-stack mbuf suitable for passing to bpf_filter. 2367 * Note that we cut corners here; we only setup what's 2368 * absolutely needed--this mbuf should never go anywhere else. 2369 */ 2370 mb.m_flags = 0; 2371 mb.m_next = m; 2372 mb.m_data = data; 2373 mb.m_len = dlen; 2374 pktlen += dlen; 2375 2376 gottime = BPF_TSTAMP_NONE; 2377 2378 NET_EPOCH_ENTER(et); 2379 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2380 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2381 continue; 2382 counter_u64_add(d->bd_rcount, 1); 2383 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2384 if (slen != 0) { 2385 BPFD_LOCK(d); 2386 2387 counter_u64_add(d->bd_fcount, 1); 2388 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2389 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2390 #ifdef MAC 2391 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2392 #endif 2393 catchpacket(d, (u_char *)&mb, pktlen, slen, 2394 bpf_append_mbuf, &bt); 2395 BPFD_UNLOCK(d); 2396 } 2397 } 2398 NET_EPOCH_EXIT(et); 2399 } 2400 2401 #undef BPF_CHECK_DIRECTION 2402 #undef BPF_TSTAMP_NONE 2403 #undef BPF_TSTAMP_FAST 2404 #undef BPF_TSTAMP_NORMAL 2405 #undef BPF_TSTAMP_EXTERN 2406 2407 static int 2408 bpf_hdrlen(struct bpf_d *d) 2409 { 2410 int hdrlen; 2411 2412 hdrlen = d->bd_bif->bif_hdrlen; 2413 #ifndef BURN_BRIDGES 2414 if (d->bd_tstamp == BPF_T_NONE || 2415 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2416 #ifdef COMPAT_FREEBSD32 2417 if (d->bd_compat32) 2418 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2419 else 2420 #endif 2421 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2422 else 2423 #endif 2424 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2425 #ifdef COMPAT_FREEBSD32 2426 if (d->bd_compat32) 2427 hdrlen = BPF_WORDALIGN32(hdrlen); 2428 else 2429 #endif 2430 hdrlen = BPF_WORDALIGN(hdrlen); 2431 2432 return (hdrlen - d->bd_bif->bif_hdrlen); 2433 } 2434 2435 static void 2436 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2437 { 2438 struct bintime bt2, boottimebin; 2439 struct timeval tsm; 2440 struct timespec tsn; 2441 2442 if ((tstype & BPF_T_MONOTONIC) == 0) { 2443 bt2 = *bt; 2444 getboottimebin(&boottimebin); 2445 bintime_add(&bt2, &boottimebin); 2446 bt = &bt2; 2447 } 2448 switch (BPF_T_FORMAT(tstype)) { 2449 case BPF_T_MICROTIME: 2450 bintime2timeval(bt, &tsm); 2451 ts->bt_sec = tsm.tv_sec; 2452 ts->bt_frac = tsm.tv_usec; 2453 break; 2454 case BPF_T_NANOTIME: 2455 bintime2timespec(bt, &tsn); 2456 ts->bt_sec = tsn.tv_sec; 2457 ts->bt_frac = tsn.tv_nsec; 2458 break; 2459 case BPF_T_BINTIME: 2460 ts->bt_sec = bt->sec; 2461 ts->bt_frac = bt->frac; 2462 break; 2463 } 2464 } 2465 2466 /* 2467 * Move the packet data from interface memory (pkt) into the 2468 * store buffer. "cpfn" is the routine called to do the actual data 2469 * transfer. bcopy is passed in to copy contiguous chunks, while 2470 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2471 * pkt is really an mbuf. 2472 */ 2473 static void 2474 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2475 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2476 struct bintime *bt) 2477 { 2478 struct bpf_xhdr hdr; 2479 #ifndef BURN_BRIDGES 2480 struct bpf_hdr hdr_old; 2481 #ifdef COMPAT_FREEBSD32 2482 struct bpf_hdr32 hdr32_old; 2483 #endif 2484 #endif 2485 int caplen, curlen, hdrlen, totlen; 2486 int do_wakeup = 0; 2487 int do_timestamp; 2488 int tstype; 2489 2490 BPFD_LOCK_ASSERT(d); 2491 if (d->bd_bif == NULL) { 2492 /* Descriptor was detached in concurrent thread */ 2493 counter_u64_add(d->bd_dcount, 1); 2494 return; 2495 } 2496 2497 /* 2498 * Detect whether user space has released a buffer back to us, and if 2499 * so, move it from being a hold buffer to a free buffer. This may 2500 * not be the best place to do it (for example, we might only want to 2501 * run this check if we need the space), but for now it's a reliable 2502 * spot to do it. 2503 */ 2504 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2505 d->bd_fbuf = d->bd_hbuf; 2506 d->bd_hbuf = NULL; 2507 d->bd_hlen = 0; 2508 bpf_buf_reclaimed(d); 2509 } 2510 2511 /* 2512 * Figure out how many bytes to move. If the packet is 2513 * greater or equal to the snapshot length, transfer that 2514 * much. Otherwise, transfer the whole packet (unless 2515 * we hit the buffer size limit). 2516 */ 2517 hdrlen = bpf_hdrlen(d); 2518 totlen = hdrlen + min(snaplen, pktlen); 2519 if (totlen > d->bd_bufsize) 2520 totlen = d->bd_bufsize; 2521 2522 /* 2523 * Round up the end of the previous packet to the next longword. 2524 * 2525 * Drop the packet if there's no room and no hope of room 2526 * If the packet would overflow the storage buffer or the storage 2527 * buffer is considered immutable by the buffer model, try to rotate 2528 * the buffer and wakeup pending processes. 2529 */ 2530 #ifdef COMPAT_FREEBSD32 2531 if (d->bd_compat32) 2532 curlen = BPF_WORDALIGN32(d->bd_slen); 2533 else 2534 #endif 2535 curlen = BPF_WORDALIGN(d->bd_slen); 2536 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2537 if (d->bd_fbuf == NULL) { 2538 /* 2539 * There's no room in the store buffer, and no 2540 * prospect of room, so drop the packet. Notify the 2541 * buffer model. 2542 */ 2543 bpf_buffull(d); 2544 counter_u64_add(d->bd_dcount, 1); 2545 return; 2546 } 2547 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2548 ROTATE_BUFFERS(d); 2549 do_wakeup = 1; 2550 curlen = 0; 2551 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2552 /* 2553 * Immediate mode is set, or the read timeout has already 2554 * expired during a select call. A packet arrived, so the 2555 * reader should be woken up. 2556 */ 2557 do_wakeup = 1; 2558 caplen = totlen - hdrlen; 2559 tstype = d->bd_tstamp; 2560 do_timestamp = tstype != BPF_T_NONE; 2561 #ifndef BURN_BRIDGES 2562 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2563 struct bpf_ts ts; 2564 if (do_timestamp) 2565 bpf_bintime2ts(bt, &ts, tstype); 2566 #ifdef COMPAT_FREEBSD32 2567 if (d->bd_compat32) { 2568 bzero(&hdr32_old, sizeof(hdr32_old)); 2569 if (do_timestamp) { 2570 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2571 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2572 } 2573 hdr32_old.bh_datalen = pktlen; 2574 hdr32_old.bh_hdrlen = hdrlen; 2575 hdr32_old.bh_caplen = caplen; 2576 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2577 sizeof(hdr32_old)); 2578 goto copy; 2579 } 2580 #endif 2581 bzero(&hdr_old, sizeof(hdr_old)); 2582 if (do_timestamp) { 2583 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2584 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2585 } 2586 hdr_old.bh_datalen = pktlen; 2587 hdr_old.bh_hdrlen = hdrlen; 2588 hdr_old.bh_caplen = caplen; 2589 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2590 sizeof(hdr_old)); 2591 goto copy; 2592 } 2593 #endif 2594 2595 /* 2596 * Append the bpf header. Note we append the actual header size, but 2597 * move forward the length of the header plus padding. 2598 */ 2599 bzero(&hdr, sizeof(hdr)); 2600 if (do_timestamp) 2601 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2602 hdr.bh_datalen = pktlen; 2603 hdr.bh_hdrlen = hdrlen; 2604 hdr.bh_caplen = caplen; 2605 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2606 2607 /* 2608 * Copy the packet data into the store buffer and update its length. 2609 */ 2610 #ifndef BURN_BRIDGES 2611 copy: 2612 #endif 2613 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2614 d->bd_slen = curlen + totlen; 2615 2616 if (do_wakeup) 2617 bpf_wakeup(d); 2618 } 2619 2620 /* 2621 * Free buffers currently in use by a descriptor. 2622 * Called on close. 2623 */ 2624 static void 2625 bpfd_free(epoch_context_t ctx) 2626 { 2627 struct bpf_d *d; 2628 struct bpf_program_buffer *p; 2629 2630 /* 2631 * We don't need to lock out interrupts since this descriptor has 2632 * been detached from its interface and it yet hasn't been marked 2633 * free. 2634 */ 2635 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2636 bpf_free(d); 2637 if (d->bd_rfilter != NULL) { 2638 p = __containerof((void *)d->bd_rfilter, 2639 struct bpf_program_buffer, buffer); 2640 #ifdef BPF_JITTER 2641 p->func = d->bd_bfilter; 2642 #endif 2643 bpf_program_buffer_free(&p->epoch_ctx); 2644 } 2645 if (d->bd_wfilter != NULL) { 2646 p = __containerof((void *)d->bd_wfilter, 2647 struct bpf_program_buffer, buffer); 2648 #ifdef BPF_JITTER 2649 p->func = NULL; 2650 #endif 2651 bpf_program_buffer_free(&p->epoch_ctx); 2652 } 2653 2654 mtx_destroy(&d->bd_lock); 2655 counter_u64_free(d->bd_rcount); 2656 counter_u64_free(d->bd_dcount); 2657 counter_u64_free(d->bd_fcount); 2658 counter_u64_free(d->bd_wcount); 2659 counter_u64_free(d->bd_wfcount); 2660 counter_u64_free(d->bd_wdcount); 2661 counter_u64_free(d->bd_zcopy); 2662 free(d, M_BPF); 2663 } 2664 2665 /* 2666 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2667 * fixed size of the link header (variable length headers not yet supported). 2668 */ 2669 void 2670 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2671 { 2672 2673 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2674 } 2675 2676 /* 2677 * Attach an interface to bpf. ifp is a pointer to the structure 2678 * defining the interface to be attached, dlt is the link layer type, 2679 * and hdrlen is the fixed size of the link header (variable length 2680 * headers are not yet supporrted). 2681 */ 2682 void 2683 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, 2684 struct bpf_if **driverp) 2685 { 2686 struct bpf_if *bp; 2687 2688 KASSERT(*driverp == NULL, 2689 ("bpfattach2: driverp already initialized")); 2690 2691 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2692 2693 CK_LIST_INIT(&bp->bif_dlist); 2694 CK_LIST_INIT(&bp->bif_wlist); 2695 bp->bif_ifp = ifp; 2696 bp->bif_dlt = dlt; 2697 bp->bif_hdrlen = hdrlen; 2698 bp->bif_bpf = driverp; 2699 bp->bif_refcnt = 1; 2700 *driverp = bp; 2701 /* 2702 * Reference ifnet pointer, so it won't freed until 2703 * we release it. 2704 */ 2705 if_ref(ifp); 2706 BPF_LOCK(); 2707 CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2708 BPF_UNLOCK(); 2709 2710 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2711 if_printf(ifp, "bpf attached\n"); 2712 } 2713 2714 #ifdef VIMAGE 2715 /* 2716 * When moving interfaces between vnet instances we need a way to 2717 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2718 * after the vmove. We unfortunately have no device driver infrastructure 2719 * to query the interface for these values after creation/attach, thus 2720 * add this as a workaround. 2721 */ 2722 int 2723 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2724 { 2725 2726 if (bp == NULL) 2727 return (ENXIO); 2728 if (bif_dlt == NULL && bif_hdrlen == NULL) 2729 return (0); 2730 2731 if (bif_dlt != NULL) 2732 *bif_dlt = bp->bif_dlt; 2733 if (bif_hdrlen != NULL) 2734 *bif_hdrlen = bp->bif_hdrlen; 2735 2736 return (0); 2737 } 2738 #endif 2739 2740 /* 2741 * Detach bpf from an interface. This involves detaching each descriptor 2742 * associated with the interface. Notify each descriptor as it's detached 2743 * so that any sleepers wake up and get ENXIO. 2744 */ 2745 void 2746 bpfdetach(struct ifnet *ifp) 2747 { 2748 struct bpf_if *bp, *bp_temp; 2749 struct bpf_d *d; 2750 2751 BPF_LOCK(); 2752 /* Find all bpf_if struct's which reference ifp and detach them. */ 2753 CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2754 if (ifp != bp->bif_ifp) 2755 continue; 2756 2757 CK_LIST_REMOVE(bp, bif_next); 2758 *bp->bif_bpf = (struct bpf_if *)&dead_bpf_if; 2759 2760 CTR4(KTR_NET, 2761 "%s: sheduling free for encap %d (%p) for if %p", 2762 __func__, bp->bif_dlt, bp, ifp); 2763 2764 /* Detach common descriptors */ 2765 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2766 bpf_detachd_locked(d, true); 2767 } 2768 2769 /* Detach writer-only descriptors */ 2770 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2771 bpf_detachd_locked(d, true); 2772 } 2773 bpfif_rele(bp); 2774 } 2775 BPF_UNLOCK(); 2776 } 2777 2778 /* 2779 * Get a list of available data link type of the interface. 2780 */ 2781 static int 2782 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2783 { 2784 struct ifnet *ifp; 2785 struct bpf_if *bp; 2786 u_int *lst; 2787 int error, n, n1; 2788 2789 BPF_LOCK_ASSERT(); 2790 2791 ifp = d->bd_bif->bif_ifp; 2792 n1 = 0; 2793 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2794 if (bp->bif_ifp == ifp) 2795 n1++; 2796 } 2797 if (bfl->bfl_list == NULL) { 2798 bfl->bfl_len = n1; 2799 return (0); 2800 } 2801 if (n1 > bfl->bfl_len) 2802 return (ENOMEM); 2803 2804 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2805 n = 0; 2806 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2807 if (bp->bif_ifp != ifp) 2808 continue; 2809 lst[n++] = bp->bif_dlt; 2810 } 2811 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2812 free(lst, M_TEMP); 2813 bfl->bfl_len = n; 2814 return (error); 2815 } 2816 2817 /* 2818 * Set the data link type of a BPF instance. 2819 */ 2820 static int 2821 bpf_setdlt(struct bpf_d *d, u_int dlt) 2822 { 2823 int error, opromisc; 2824 struct ifnet *ifp; 2825 struct bpf_if *bp; 2826 2827 BPF_LOCK_ASSERT(); 2828 MPASS(d->bd_bif != NULL); 2829 2830 /* 2831 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2832 * changed while we hold global lock. 2833 */ 2834 if (d->bd_bif->bif_dlt == dlt) 2835 return (0); 2836 2837 ifp = d->bd_bif->bif_ifp; 2838 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2839 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2840 break; 2841 } 2842 if (bp == NULL) 2843 return (EINVAL); 2844 2845 opromisc = d->bd_promisc; 2846 bpf_attachd(d, bp); 2847 if (opromisc) { 2848 error = ifpromisc(bp->bif_ifp, 1); 2849 if (error) 2850 if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", 2851 __func__, error); 2852 else 2853 d->bd_promisc = 1; 2854 } 2855 return (0); 2856 } 2857 2858 static void 2859 bpf_drvinit(void *unused) 2860 { 2861 struct cdev *dev; 2862 2863 sx_init(&bpf_sx, "bpf global lock"); 2864 CK_LIST_INIT(&bpf_iflist); 2865 2866 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2867 /* For compatibility */ 2868 make_dev_alias(dev, "bpf0"); 2869 } 2870 2871 /* 2872 * Zero out the various packet counters associated with all of the bpf 2873 * descriptors. At some point, we will probably want to get a bit more 2874 * granular and allow the user to specify descriptors to be zeroed. 2875 */ 2876 static void 2877 bpf_zero_counters(void) 2878 { 2879 struct bpf_if *bp; 2880 struct bpf_d *bd; 2881 2882 BPF_LOCK(); 2883 /* 2884 * We are protected by global lock here, interfaces and 2885 * descriptors can not be deleted while we hold it. 2886 */ 2887 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2888 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2889 counter_u64_zero(bd->bd_rcount); 2890 counter_u64_zero(bd->bd_dcount); 2891 counter_u64_zero(bd->bd_fcount); 2892 counter_u64_zero(bd->bd_wcount); 2893 counter_u64_zero(bd->bd_wfcount); 2894 counter_u64_zero(bd->bd_zcopy); 2895 } 2896 } 2897 BPF_UNLOCK(); 2898 } 2899 2900 /* 2901 * Fill filter statistics 2902 */ 2903 static void 2904 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2905 { 2906 2907 BPF_LOCK_ASSERT(); 2908 bzero(d, sizeof(*d)); 2909 d->bd_structsize = sizeof(*d); 2910 d->bd_immediate = bd->bd_immediate; 2911 d->bd_promisc = bd->bd_promisc; 2912 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2913 d->bd_direction = bd->bd_direction; 2914 d->bd_feedback = bd->bd_feedback; 2915 d->bd_async = bd->bd_async; 2916 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2917 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2918 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2919 d->bd_sig = bd->bd_sig; 2920 d->bd_slen = bd->bd_slen; 2921 d->bd_hlen = bd->bd_hlen; 2922 d->bd_bufsize = bd->bd_bufsize; 2923 d->bd_pid = bd->bd_pid; 2924 strlcpy(d->bd_ifname, 2925 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2926 d->bd_locked = bd->bd_locked; 2927 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2928 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2929 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2930 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2931 d->bd_bufmode = bd->bd_bufmode; 2932 } 2933 2934 /* 2935 * Handle `netstat -B' stats request 2936 */ 2937 static int 2938 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2939 { 2940 static const struct xbpf_d zerostats; 2941 struct xbpf_d *xbdbuf, *xbd, tempstats; 2942 int index, error; 2943 struct bpf_if *bp; 2944 struct bpf_d *bd; 2945 2946 /* 2947 * XXX This is not technically correct. It is possible for non 2948 * privileged users to open bpf devices. It would make sense 2949 * if the users who opened the devices were able to retrieve 2950 * the statistics for them, too. 2951 */ 2952 error = priv_check(req->td, PRIV_NET_BPF); 2953 if (error) 2954 return (error); 2955 /* 2956 * Check to see if the user is requesting that the counters be 2957 * zeroed out. Explicitly check that the supplied data is zeroed, 2958 * as we aren't allowing the user to set the counters currently. 2959 */ 2960 if (req->newptr != NULL) { 2961 if (req->newlen != sizeof(tempstats)) 2962 return (EINVAL); 2963 memset(&tempstats, 0, sizeof(tempstats)); 2964 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2965 if (error) 2966 return (error); 2967 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2968 return (EINVAL); 2969 bpf_zero_counters(); 2970 return (0); 2971 } 2972 if (req->oldptr == NULL) 2973 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2974 if (bpf_bpfd_cnt == 0) 2975 return (SYSCTL_OUT(req, 0, 0)); 2976 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2977 BPF_LOCK(); 2978 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2979 BPF_UNLOCK(); 2980 free(xbdbuf, M_BPF); 2981 return (ENOMEM); 2982 } 2983 index = 0; 2984 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2985 /* Send writers-only first */ 2986 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2987 xbd = &xbdbuf[index++]; 2988 bpfstats_fill_xbpf(xbd, bd); 2989 } 2990 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2991 xbd = &xbdbuf[index++]; 2992 bpfstats_fill_xbpf(xbd, bd); 2993 } 2994 } 2995 BPF_UNLOCK(); 2996 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2997 free(xbdbuf, M_BPF); 2998 return (error); 2999 } 3000 3001 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 3002 3003 #else /* !DEV_BPF && !NETGRAPH_BPF */ 3004 3005 /* 3006 * NOP stubs to allow bpf-using drivers to load and function. 3007 * 3008 * A 'better' implementation would allow the core bpf functionality 3009 * to be loaded at runtime. 3010 */ 3011 3012 void 3013 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3014 { 3015 } 3016 3017 void 3018 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3019 { 3020 } 3021 3022 void 3023 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3024 { 3025 } 3026 3027 void 3028 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3029 { 3030 3031 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3032 } 3033 3034 void 3035 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3036 { 3037 3038 *driverp = (struct bpf_if *)&dead_bpf_if; 3039 } 3040 3041 void 3042 bpfdetach(struct ifnet *ifp) 3043 { 3044 } 3045 3046 u_int 3047 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3048 { 3049 return -1; /* "no filter" behaviour */ 3050 } 3051 3052 int 3053 bpf_validate(const struct bpf_insn *f, int len) 3054 { 3055 return 0; /* false */ 3056 } 3057 3058 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3059 3060 #ifdef DDB 3061 static void 3062 bpf_show_bpf_if(struct bpf_if *bpf_if) 3063 { 3064 3065 if (bpf_if == NULL) 3066 return; 3067 db_printf("%p:\n", bpf_if); 3068 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3069 /* bif_ext.bif_next */ 3070 /* bif_ext.bif_dlist */ 3071 BPF_DB_PRINTF("%#x", bif_dlt); 3072 BPF_DB_PRINTF("%u", bif_hdrlen); 3073 /* bif_wlist */ 3074 BPF_DB_PRINTF("%p", bif_ifp); 3075 BPF_DB_PRINTF("%p", bif_bpf); 3076 BPF_DB_PRINTF("%u", bif_refcnt); 3077 } 3078 3079 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3080 { 3081 3082 if (!have_addr) { 3083 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3084 return; 3085 } 3086 3087 bpf_show_bpf_if((struct bpf_if *)addr); 3088 } 3089 #endif 3090