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) { 580 581 case DLT_SLIP: 582 sockp->sa_family = AF_INET; 583 hlen = 0; 584 break; 585 586 case DLT_EN10MB: 587 sockp->sa_family = AF_UNSPEC; 588 /* XXX Would MAXLINKHDR be better? */ 589 hlen = ETHER_HDR_LEN; 590 break; 591 592 case DLT_FDDI: 593 sockp->sa_family = AF_IMPLINK; 594 hlen = 0; 595 break; 596 597 case DLT_RAW: 598 sockp->sa_family = AF_UNSPEC; 599 hlen = 0; 600 break; 601 602 case DLT_NULL: 603 /* 604 * null interface types require a 4 byte pseudo header which 605 * corresponds to the address family of the packet. 606 */ 607 sockp->sa_family = AF_UNSPEC; 608 hlen = 4; 609 break; 610 611 case DLT_ATM_RFC1483: 612 /* 613 * en atm driver requires 4-byte atm pseudo header. 614 * though it isn't standard, vpi:vci needs to be 615 * specified anyway. 616 */ 617 sockp->sa_family = AF_UNSPEC; 618 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 619 break; 620 621 case DLT_PPP: 622 sockp->sa_family = AF_UNSPEC; 623 hlen = 4; /* This should match PPP_HDRLEN */ 624 break; 625 626 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 627 sockp->sa_family = AF_IEEE80211; 628 hlen = 0; 629 break; 630 631 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 632 sockp->sa_family = AF_IEEE80211; 633 sockp->sa_len = 12; /* XXX != 0 */ 634 hlen = sizeof(struct ieee80211_bpf_params); 635 break; 636 637 default: 638 return (EIO); 639 } 640 641 len = uio->uio_resid; 642 if (len < hlen || len - hlen > ifp->if_mtu) 643 return (EMSGSIZE); 644 645 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR); 646 if (m == NULL) 647 return (EIO); 648 m->m_pkthdr.len = m->m_len = len; 649 *mp = m; 650 651 error = uiomove(mtod(m, u_char *), len, uio); 652 if (error) 653 goto bad; 654 655 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 656 if (slen == 0) { 657 error = EPERM; 658 goto bad; 659 } 660 661 /* Check for multicast destination */ 662 switch (linktype) { 663 case DLT_EN10MB: 664 eh = mtod(m, struct ether_header *); 665 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 666 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 667 ETHER_ADDR_LEN) == 0) 668 m->m_flags |= M_BCAST; 669 else 670 m->m_flags |= M_MCAST; 671 } 672 if (d->bd_hdrcmplt == 0) { 673 memcpy(eh->ether_shost, IF_LLADDR(ifp), 674 sizeof(eh->ether_shost)); 675 } 676 break; 677 } 678 679 /* 680 * Make room for link header, and copy it to sockaddr 681 */ 682 if (hlen != 0) { 683 if (sockp->sa_family == AF_IEEE80211) { 684 /* 685 * Collect true length from the parameter header 686 * NB: sockp is known to be zero'd so if we do a 687 * short copy unspecified parameters will be 688 * zero. 689 * NB: packet may not be aligned after stripping 690 * bpf params 691 * XXX check ibp_vers 692 */ 693 p = mtod(m, const struct ieee80211_bpf_params *); 694 hlen = p->ibp_len; 695 if (hlen > sizeof(sockp->sa_data)) { 696 error = EINVAL; 697 goto bad; 698 } 699 } 700 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 701 } 702 *hdrlen = hlen; 703 704 return (0); 705 bad: 706 m_freem(m); 707 return (error); 708 } 709 710 /* 711 * Attach descriptor to the bpf interface, i.e. make d listen on bp, 712 * then reset its buffers and counters with reset_d(). 713 */ 714 static void 715 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 716 { 717 int op_w; 718 719 BPF_LOCK_ASSERT(); 720 721 /* 722 * Save sysctl value to protect from sysctl change 723 * between reads 724 */ 725 op_w = V_bpf_optimize_writers || d->bd_writer; 726 727 if (d->bd_bif != NULL) 728 bpf_detachd_locked(d, false); 729 /* 730 * Point d at bp, and add d to the interface's list. 731 * Since there are many applications using BPF for 732 * sending raw packets only (dhcpd, cdpd are good examples) 733 * we can delay adding d to the list of active listeners until 734 * some filter is configured. 735 */ 736 737 BPFD_LOCK(d); 738 /* 739 * Hold reference to bpif while descriptor uses this interface. 740 */ 741 bpfif_ref(bp); 742 d->bd_bif = bp; 743 if (op_w != 0) { 744 /* Add to writers-only list */ 745 CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 746 /* 747 * We decrement bd_writer on every filter set operation. 748 * First BIOCSETF is done by pcap_open_live() to set up 749 * snap length. After that appliation usually sets its own 750 * filter. 751 */ 752 d->bd_writer = 2; 753 } else 754 CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 755 756 reset_d(d); 757 BPFD_UNLOCK(d); 758 bpf_bpfd_cnt++; 759 760 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 761 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 762 763 if (op_w == 0) 764 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 765 } 766 767 /* 768 * Check if we need to upgrade our descriptor @d from write-only mode. 769 */ 770 static int 771 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 772 int flen) 773 { 774 int is_snap, need_upgrade; 775 776 /* 777 * Check if we've already upgraded or new filter is empty. 778 */ 779 if (d->bd_writer == 0 || fcode == NULL) 780 return (0); 781 782 need_upgrade = 0; 783 784 /* 785 * Check if cmd looks like snaplen setting from 786 * pcap_bpf.c:pcap_open_live(). 787 * Note we're not checking .k value here: 788 * while pcap_open_live() definitely sets to non-zero value, 789 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 790 * do not consider upgrading immediately 791 */ 792 if (cmd == BIOCSETF && flen == 1 && 793 fcode[0].code == (BPF_RET | BPF_K)) 794 is_snap = 1; 795 else 796 is_snap = 0; 797 798 if (is_snap == 0) { 799 /* 800 * We're setting first filter and it doesn't look like 801 * setting snaplen. We're probably using bpf directly. 802 * Upgrade immediately. 803 */ 804 need_upgrade = 1; 805 } else { 806 /* 807 * Do not require upgrade by first BIOCSETF 808 * (used to set snaplen) by pcap_open_live(). 809 */ 810 811 if (--d->bd_writer == 0) { 812 /* 813 * First snaplen filter has already 814 * been set. This is probably catch-all 815 * filter 816 */ 817 need_upgrade = 1; 818 } 819 } 820 821 CTR5(KTR_NET, 822 "%s: filter function set by pid %d, " 823 "bd_writer counter %d, snap %d upgrade %d", 824 __func__, d->bd_pid, d->bd_writer, 825 is_snap, need_upgrade); 826 827 return (need_upgrade); 828 } 829 830 /* 831 * Detach a file from its interface. 832 */ 833 static void 834 bpf_detachd(struct bpf_d *d) 835 { 836 BPF_LOCK(); 837 bpf_detachd_locked(d, false); 838 BPF_UNLOCK(); 839 } 840 841 static void 842 bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) 843 { 844 struct bpf_if *bp; 845 struct ifnet *ifp; 846 int error; 847 848 BPF_LOCK_ASSERT(); 849 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 850 851 /* Check if descriptor is attached */ 852 if ((bp = d->bd_bif) == NULL) 853 return; 854 855 BPFD_LOCK(d); 856 /* Remove d from the interface's descriptor list. */ 857 CK_LIST_REMOVE(d, bd_next); 858 /* Save bd_writer value */ 859 error = d->bd_writer; 860 ifp = bp->bif_ifp; 861 d->bd_bif = NULL; 862 if (detached_ifp) { 863 /* 864 * Notify descriptor as it's detached, so that any 865 * sleepers wake up and get ENXIO. 866 */ 867 bpf_wakeup(d); 868 } 869 BPFD_UNLOCK(d); 870 bpf_bpfd_cnt--; 871 872 /* Call event handler iff d is attached */ 873 if (error == 0) 874 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 875 876 /* 877 * Check if this descriptor had requested promiscuous mode. 878 * If so and ifnet is not detached, turn it off. 879 */ 880 if (d->bd_promisc && !detached_ifp) { 881 d->bd_promisc = 0; 882 CURVNET_SET(ifp->if_vnet); 883 error = ifpromisc(ifp, 0); 884 CURVNET_RESTORE(); 885 if (error != 0 && error != ENXIO) { 886 /* 887 * ENXIO can happen if a pccard is unplugged 888 * Something is really wrong if we were able to put 889 * the driver into promiscuous mode, but can't 890 * take it out. 891 */ 892 if_printf(bp->bif_ifp, 893 "bpf_detach: ifpromisc failed (%d)\n", error); 894 } 895 } 896 bpfif_rele(bp); 897 } 898 899 /* 900 * Close the descriptor by detaching it from its interface, 901 * deallocating its buffers, and marking it free. 902 */ 903 static void 904 bpf_dtor(void *data) 905 { 906 struct bpf_d *d = data; 907 908 BPFD_LOCK(d); 909 if (d->bd_state == BPF_WAITING) 910 callout_stop(&d->bd_callout); 911 d->bd_state = BPF_IDLE; 912 BPFD_UNLOCK(d); 913 funsetown(&d->bd_sigio); 914 bpf_detachd(d); 915 #ifdef MAC 916 mac_bpfdesc_destroy(d); 917 #endif /* MAC */ 918 seldrain(&d->bd_sel); 919 knlist_destroy(&d->bd_sel.si_note); 920 callout_drain(&d->bd_callout); 921 bpfd_rele(d); 922 } 923 924 /* 925 * Open ethernet device. Returns ENXIO for illegal minor device number, 926 * EBUSY if file is open by another process. 927 */ 928 /* ARGSUSED */ 929 static int 930 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 931 { 932 struct bpf_d *d; 933 int error; 934 935 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 936 error = devfs_set_cdevpriv(d, bpf_dtor); 937 if (error != 0) { 938 free(d, M_BPF); 939 return (error); 940 } 941 942 /* Setup counters */ 943 d->bd_rcount = counter_u64_alloc(M_WAITOK); 944 d->bd_dcount = counter_u64_alloc(M_WAITOK); 945 d->bd_fcount = counter_u64_alloc(M_WAITOK); 946 d->bd_wcount = counter_u64_alloc(M_WAITOK); 947 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 948 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 949 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 950 951 /* 952 * For historical reasons, perform a one-time initialization call to 953 * the buffer routines, even though we're not yet committed to a 954 * particular buffer method. 955 */ 956 bpf_buffer_init(d); 957 if ((flags & FREAD) == 0) 958 d->bd_writer = 2; 959 d->bd_hbuf_in_use = 0; 960 d->bd_bufmode = BPF_BUFMODE_BUFFER; 961 d->bd_sig = SIGIO; 962 d->bd_direction = BPF_D_INOUT; 963 d->bd_refcnt = 1; 964 BPF_PID_REFRESH(d, td); 965 #ifdef MAC 966 mac_bpfdesc_init(d); 967 mac_bpfdesc_create(td->td_ucred, d); 968 #endif 969 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 970 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 971 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 972 973 return (0); 974 } 975 976 /* 977 * bpfread - read next chunk of packets from buffers 978 */ 979 static int 980 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 981 { 982 struct bpf_d *d; 983 int error; 984 int non_block; 985 int timed_out; 986 987 error = devfs_get_cdevpriv((void **)&d); 988 if (error != 0) 989 return (error); 990 991 /* 992 * Restrict application to use a buffer the same size as 993 * as kernel buffers. 994 */ 995 if (uio->uio_resid != d->bd_bufsize) 996 return (EINVAL); 997 998 non_block = ((ioflag & O_NONBLOCK) != 0); 999 1000 BPFD_LOCK(d); 1001 BPF_PID_REFRESH_CUR(d); 1002 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 1003 BPFD_UNLOCK(d); 1004 return (EOPNOTSUPP); 1005 } 1006 if (d->bd_state == BPF_WAITING) 1007 callout_stop(&d->bd_callout); 1008 timed_out = (d->bd_state == BPF_TIMED_OUT); 1009 d->bd_state = BPF_IDLE; 1010 while (d->bd_hbuf_in_use) { 1011 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1012 PRINET|PCATCH, "bd_hbuf", 0); 1013 if (error != 0) { 1014 BPFD_UNLOCK(d); 1015 return (error); 1016 } 1017 } 1018 /* 1019 * If the hold buffer is empty, then do a timed sleep, which 1020 * ends when the timeout expires or when enough packets 1021 * have arrived to fill the store buffer. 1022 */ 1023 while (d->bd_hbuf == NULL) { 1024 if (d->bd_slen != 0) { 1025 /* 1026 * A packet(s) either arrived since the previous 1027 * read or arrived while we were asleep. 1028 */ 1029 if (d->bd_immediate || non_block || timed_out) { 1030 /* 1031 * Rotate the buffers and return what's here 1032 * if we are in immediate mode, non-blocking 1033 * flag is set, or this descriptor timed out. 1034 */ 1035 ROTATE_BUFFERS(d); 1036 break; 1037 } 1038 } 1039 1040 /* 1041 * No data is available, check to see if the bpf device 1042 * is still pointed at a real interface. If not, return 1043 * ENXIO so that the userland process knows to rebind 1044 * it before using it again. 1045 */ 1046 if (d->bd_bif == NULL) { 1047 BPFD_UNLOCK(d); 1048 return (ENXIO); 1049 } 1050 1051 if (non_block) { 1052 BPFD_UNLOCK(d); 1053 return (EWOULDBLOCK); 1054 } 1055 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 1056 "bpf", d->bd_rtout); 1057 if (error == EINTR || error == ERESTART) { 1058 BPFD_UNLOCK(d); 1059 return (error); 1060 } 1061 if (error == EWOULDBLOCK) { 1062 /* 1063 * On a timeout, return what's in the buffer, 1064 * which may be nothing. If there is something 1065 * in the store buffer, we can rotate the buffers. 1066 */ 1067 if (d->bd_hbuf) 1068 /* 1069 * We filled up the buffer in between 1070 * getting the timeout and arriving 1071 * here, so we don't need to rotate. 1072 */ 1073 break; 1074 1075 if (d->bd_slen == 0) { 1076 BPFD_UNLOCK(d); 1077 return (0); 1078 } 1079 ROTATE_BUFFERS(d); 1080 break; 1081 } 1082 } 1083 /* 1084 * At this point, we know we have something in the hold slot. 1085 */ 1086 d->bd_hbuf_in_use = 1; 1087 BPFD_UNLOCK(d); 1088 1089 /* 1090 * Move data from hold buffer into user space. 1091 * We know the entire buffer is transferred since 1092 * we checked above that the read buffer is bpf_bufsize bytes. 1093 * 1094 * We do not have to worry about simultaneous reads because 1095 * we waited for sole access to the hold buffer above. 1096 */ 1097 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1098 1099 BPFD_LOCK(d); 1100 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1101 d->bd_fbuf = d->bd_hbuf; 1102 d->bd_hbuf = NULL; 1103 d->bd_hlen = 0; 1104 bpf_buf_reclaimed(d); 1105 d->bd_hbuf_in_use = 0; 1106 wakeup(&d->bd_hbuf_in_use); 1107 BPFD_UNLOCK(d); 1108 1109 return (error); 1110 } 1111 1112 /* 1113 * If there are processes sleeping on this descriptor, wake them up. 1114 */ 1115 static __inline void 1116 bpf_wakeup(struct bpf_d *d) 1117 { 1118 1119 BPFD_LOCK_ASSERT(d); 1120 if (d->bd_state == BPF_WAITING) { 1121 callout_stop(&d->bd_callout); 1122 d->bd_state = BPF_IDLE; 1123 } 1124 wakeup(d); 1125 if (d->bd_async && d->bd_sig && d->bd_sigio) 1126 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1127 1128 selwakeuppri(&d->bd_sel, PRINET); 1129 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1130 } 1131 1132 static void 1133 bpf_timed_out(void *arg) 1134 { 1135 struct bpf_d *d = (struct bpf_d *)arg; 1136 1137 BPFD_LOCK_ASSERT(d); 1138 1139 if (callout_pending(&d->bd_callout) || 1140 !callout_active(&d->bd_callout)) 1141 return; 1142 if (d->bd_state == BPF_WAITING) { 1143 d->bd_state = BPF_TIMED_OUT; 1144 if (d->bd_slen != 0) 1145 bpf_wakeup(d); 1146 } 1147 } 1148 1149 static int 1150 bpf_ready(struct bpf_d *d) 1151 { 1152 1153 BPFD_LOCK_ASSERT(d); 1154 1155 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1156 return (1); 1157 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1158 d->bd_slen != 0) 1159 return (1); 1160 return (0); 1161 } 1162 1163 static int 1164 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1165 { 1166 struct route ro; 1167 struct sockaddr dst; 1168 struct epoch_tracker et; 1169 struct bpf_if *bp; 1170 struct bpf_d *d; 1171 struct ifnet *ifp; 1172 struct mbuf *m, *mc; 1173 int error, hlen; 1174 1175 error = devfs_get_cdevpriv((void **)&d); 1176 if (error != 0) 1177 return (error); 1178 1179 NET_EPOCH_ENTER(et); 1180 BPFD_LOCK(d); 1181 BPF_PID_REFRESH_CUR(d); 1182 counter_u64_add(d->bd_wcount, 1); 1183 if ((bp = d->bd_bif) == NULL) { 1184 error = ENXIO; 1185 goto out_locked; 1186 } 1187 1188 ifp = bp->bif_ifp; 1189 if ((ifp->if_flags & IFF_UP) == 0) { 1190 error = ENETDOWN; 1191 goto out_locked; 1192 } 1193 1194 if (uio->uio_resid == 0) 1195 goto out_locked; 1196 1197 bzero(&dst, sizeof(dst)); 1198 m = NULL; 1199 hlen = 0; 1200 1201 /* 1202 * Take extra reference, unlock d and exit from epoch section, 1203 * since bpf_movein() can sleep. 1204 */ 1205 bpfd_ref(d); 1206 NET_EPOCH_EXIT(et); 1207 BPFD_UNLOCK(d); 1208 1209 error = bpf_movein(uio, (int)bp->bif_dlt, ifp, 1210 &m, &dst, &hlen, d); 1211 1212 if (error != 0) { 1213 counter_u64_add(d->bd_wdcount, 1); 1214 bpfd_rele(d); 1215 return (error); 1216 } 1217 1218 BPFD_LOCK(d); 1219 /* 1220 * Check that descriptor is still attached to the interface. 1221 * This can happen on bpfdetach(). To avoid access to detached 1222 * ifnet, free mbuf and return ENXIO. 1223 */ 1224 if (d->bd_bif == NULL) { 1225 counter_u64_add(d->bd_wdcount, 1); 1226 BPFD_UNLOCK(d); 1227 bpfd_rele(d); 1228 m_freem(m); 1229 return (ENXIO); 1230 } 1231 counter_u64_add(d->bd_wfcount, 1); 1232 if (d->bd_hdrcmplt) 1233 dst.sa_family = pseudo_AF_HDRCMPLT; 1234 1235 if (d->bd_feedback) { 1236 mc = m_dup(m, M_NOWAIT); 1237 if (mc != NULL) 1238 mc->m_pkthdr.rcvif = ifp; 1239 /* Set M_PROMISC for outgoing packets to be discarded. */ 1240 if (d->bd_direction == BPF_D_INOUT) 1241 m->m_flags |= M_PROMISC; 1242 } else 1243 mc = NULL; 1244 1245 m->m_pkthdr.len -= hlen; 1246 m->m_len -= hlen; 1247 m->m_data += hlen; /* XXX */ 1248 1249 CURVNET_SET(ifp->if_vnet); 1250 #ifdef MAC 1251 mac_bpfdesc_create_mbuf(d, m); 1252 if (mc != NULL) 1253 mac_bpfdesc_create_mbuf(d, mc); 1254 #endif 1255 1256 bzero(&ro, sizeof(ro)); 1257 if (hlen != 0) { 1258 ro.ro_prepend = (u_char *)&dst.sa_data; 1259 ro.ro_plen = hlen; 1260 ro.ro_flags = RT_HAS_HEADER; 1261 } 1262 1263 /* Avoid possible recursion on BPFD_LOCK(). */ 1264 NET_EPOCH_ENTER(et); 1265 BPFD_UNLOCK(d); 1266 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1267 if (error) 1268 counter_u64_add(d->bd_wdcount, 1); 1269 1270 if (mc != NULL) { 1271 if (error == 0) 1272 (*ifp->if_input)(ifp, mc); 1273 else 1274 m_freem(mc); 1275 } 1276 NET_EPOCH_EXIT(et); 1277 CURVNET_RESTORE(); 1278 bpfd_rele(d); 1279 return (error); 1280 1281 out_locked: 1282 counter_u64_add(d->bd_wdcount, 1); 1283 NET_EPOCH_EXIT(et); 1284 BPFD_UNLOCK(d); 1285 return (error); 1286 } 1287 1288 /* 1289 * Reset a descriptor by flushing its packet buffer and clearing the receive 1290 * and drop counts. This is doable for kernel-only buffers, but with 1291 * zero-copy buffers, we can't write to (or rotate) buffers that are 1292 * currently owned by userspace. It would be nice if we could encapsulate 1293 * this logic in the buffer code rather than here. 1294 */ 1295 static void 1296 reset_d(struct bpf_d *d) 1297 { 1298 1299 BPFD_LOCK_ASSERT(d); 1300 1301 while (d->bd_hbuf_in_use) 1302 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1303 "bd_hbuf", 0); 1304 if ((d->bd_hbuf != NULL) && 1305 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1306 /* Free the hold buffer. */ 1307 d->bd_fbuf = d->bd_hbuf; 1308 d->bd_hbuf = NULL; 1309 d->bd_hlen = 0; 1310 bpf_buf_reclaimed(d); 1311 } 1312 if (bpf_canwritebuf(d)) 1313 d->bd_slen = 0; 1314 counter_u64_zero(d->bd_rcount); 1315 counter_u64_zero(d->bd_dcount); 1316 counter_u64_zero(d->bd_fcount); 1317 counter_u64_zero(d->bd_wcount); 1318 counter_u64_zero(d->bd_wfcount); 1319 counter_u64_zero(d->bd_wdcount); 1320 counter_u64_zero(d->bd_zcopy); 1321 } 1322 1323 /* 1324 * FIONREAD Check for read packet available. 1325 * BIOCGBLEN Get buffer len [for read()]. 1326 * BIOCSETF Set read filter. 1327 * BIOCSETFNR Set read filter without resetting descriptor. 1328 * BIOCSETWF Set write filter. 1329 * BIOCFLUSH Flush read packet buffer. 1330 * BIOCPROMISC Put interface into promiscuous mode. 1331 * BIOCGDLT Get link layer type. 1332 * BIOCGETIF Get interface name. 1333 * BIOCSETIF Set interface. 1334 * BIOCSRTIMEOUT Set read timeout. 1335 * BIOCGRTIMEOUT Get read timeout. 1336 * BIOCGSTATS Get packet stats. 1337 * BIOCIMMEDIATE Set immediate mode. 1338 * BIOCVERSION Get filter language version. 1339 * BIOCGHDRCMPLT Get "header already complete" flag 1340 * BIOCSHDRCMPLT Set "header already complete" flag 1341 * BIOCGDIRECTION Get packet direction flag 1342 * BIOCSDIRECTION Set packet direction flag 1343 * BIOCGTSTAMP Get time stamp format and resolution. 1344 * BIOCSTSTAMP Set time stamp format and resolution. 1345 * BIOCLOCK Set "locked" flag 1346 * BIOCFEEDBACK Set packet feedback mode. 1347 * BIOCSETZBUF Set current zero-copy buffer locations. 1348 * BIOCGETZMAX Get maximum zero-copy buffer size. 1349 * BIOCROTZBUF Force rotation of zero-copy buffer 1350 * BIOCSETBUFMODE Set buffer mode. 1351 * BIOCGETBUFMODE Get current buffer mode. 1352 */ 1353 /* ARGSUSED */ 1354 static int 1355 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1356 struct thread *td) 1357 { 1358 struct bpf_d *d; 1359 int error; 1360 1361 error = devfs_get_cdevpriv((void **)&d); 1362 if (error != 0) 1363 return (error); 1364 1365 /* 1366 * Refresh PID associated with this descriptor. 1367 */ 1368 BPFD_LOCK(d); 1369 BPF_PID_REFRESH(d, td); 1370 if (d->bd_state == BPF_WAITING) 1371 callout_stop(&d->bd_callout); 1372 d->bd_state = BPF_IDLE; 1373 BPFD_UNLOCK(d); 1374 1375 if (d->bd_locked == 1) { 1376 switch (cmd) { 1377 case BIOCGBLEN: 1378 case BIOCFLUSH: 1379 case BIOCGDLT: 1380 case BIOCGDLTLIST: 1381 #ifdef COMPAT_FREEBSD32 1382 case BIOCGDLTLIST32: 1383 #endif 1384 case BIOCGETIF: 1385 case BIOCGRTIMEOUT: 1386 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1387 case BIOCGRTIMEOUT32: 1388 #endif 1389 case BIOCGSTATS: 1390 case BIOCVERSION: 1391 case BIOCGRSIG: 1392 case BIOCGHDRCMPLT: 1393 case BIOCSTSTAMP: 1394 case BIOCFEEDBACK: 1395 case FIONREAD: 1396 case BIOCLOCK: 1397 case BIOCSRTIMEOUT: 1398 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1399 case BIOCSRTIMEOUT32: 1400 #endif 1401 case BIOCIMMEDIATE: 1402 case TIOCGPGRP: 1403 case BIOCROTZBUF: 1404 break; 1405 default: 1406 return (EPERM); 1407 } 1408 } 1409 #ifdef COMPAT_FREEBSD32 1410 /* 1411 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1412 * that it will get 32-bit packet headers. 1413 */ 1414 switch (cmd) { 1415 case BIOCSETF32: 1416 case BIOCSETFNR32: 1417 case BIOCSETWF32: 1418 case BIOCGDLTLIST32: 1419 case BIOCGRTIMEOUT32: 1420 case BIOCSRTIMEOUT32: 1421 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1422 BPFD_LOCK(d); 1423 d->bd_compat32 = 1; 1424 BPFD_UNLOCK(d); 1425 } 1426 } 1427 #endif 1428 1429 CURVNET_SET(TD_TO_VNET(td)); 1430 switch (cmd) { 1431 1432 default: 1433 error = EINVAL; 1434 break; 1435 1436 /* 1437 * Check for read packet available. 1438 */ 1439 case FIONREAD: 1440 { 1441 int n; 1442 1443 BPFD_LOCK(d); 1444 n = d->bd_slen; 1445 while (d->bd_hbuf_in_use) 1446 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1447 PRINET, "bd_hbuf", 0); 1448 if (d->bd_hbuf) 1449 n += d->bd_hlen; 1450 BPFD_UNLOCK(d); 1451 1452 *(int *)addr = n; 1453 break; 1454 } 1455 1456 /* 1457 * Get buffer len [for read()]. 1458 */ 1459 case BIOCGBLEN: 1460 BPFD_LOCK(d); 1461 *(u_int *)addr = d->bd_bufsize; 1462 BPFD_UNLOCK(d); 1463 break; 1464 1465 /* 1466 * Set buffer length. 1467 */ 1468 case BIOCSBLEN: 1469 error = bpf_ioctl_sblen(d, (u_int *)addr); 1470 break; 1471 1472 /* 1473 * Set link layer read filter. 1474 */ 1475 case BIOCSETF: 1476 case BIOCSETFNR: 1477 case BIOCSETWF: 1478 #ifdef COMPAT_FREEBSD32 1479 case BIOCSETF32: 1480 case BIOCSETFNR32: 1481 case BIOCSETWF32: 1482 #endif 1483 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1484 break; 1485 1486 /* 1487 * Flush read packet buffer. 1488 */ 1489 case BIOCFLUSH: 1490 BPFD_LOCK(d); 1491 reset_d(d); 1492 BPFD_UNLOCK(d); 1493 break; 1494 1495 /* 1496 * Put interface into promiscuous mode. 1497 */ 1498 case BIOCPROMISC: 1499 if (d->bd_bif == NULL) { 1500 /* 1501 * No interface attached yet. 1502 */ 1503 error = EINVAL; 1504 break; 1505 } 1506 if (d->bd_promisc == 0) { 1507 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1508 if (error == 0) 1509 d->bd_promisc = 1; 1510 } 1511 break; 1512 1513 /* 1514 * Get current data link type. 1515 */ 1516 case BIOCGDLT: 1517 BPF_LOCK(); 1518 if (d->bd_bif == NULL) 1519 error = EINVAL; 1520 else 1521 *(u_int *)addr = d->bd_bif->bif_dlt; 1522 BPF_UNLOCK(); 1523 break; 1524 1525 /* 1526 * Get a list of supported data link types. 1527 */ 1528 #ifdef COMPAT_FREEBSD32 1529 case BIOCGDLTLIST32: 1530 { 1531 struct bpf_dltlist32 *list32; 1532 struct bpf_dltlist dltlist; 1533 1534 list32 = (struct bpf_dltlist32 *)addr; 1535 dltlist.bfl_len = list32->bfl_len; 1536 dltlist.bfl_list = PTRIN(list32->bfl_list); 1537 BPF_LOCK(); 1538 if (d->bd_bif == NULL) 1539 error = EINVAL; 1540 else { 1541 error = bpf_getdltlist(d, &dltlist); 1542 if (error == 0) 1543 list32->bfl_len = dltlist.bfl_len; 1544 } 1545 BPF_UNLOCK(); 1546 break; 1547 } 1548 #endif 1549 1550 case BIOCGDLTLIST: 1551 BPF_LOCK(); 1552 if (d->bd_bif == NULL) 1553 error = EINVAL; 1554 else 1555 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1556 BPF_UNLOCK(); 1557 break; 1558 1559 /* 1560 * Set data link type. 1561 */ 1562 case BIOCSDLT: 1563 BPF_LOCK(); 1564 if (d->bd_bif == NULL) 1565 error = EINVAL; 1566 else 1567 error = bpf_setdlt(d, *(u_int *)addr); 1568 BPF_UNLOCK(); 1569 break; 1570 1571 /* 1572 * Get interface name. 1573 */ 1574 case BIOCGETIF: 1575 BPF_LOCK(); 1576 if (d->bd_bif == NULL) 1577 error = EINVAL; 1578 else { 1579 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1580 struct ifreq *const ifr = (struct ifreq *)addr; 1581 1582 strlcpy(ifr->ifr_name, ifp->if_xname, 1583 sizeof(ifr->ifr_name)); 1584 } 1585 BPF_UNLOCK(); 1586 break; 1587 1588 /* 1589 * Set interface. 1590 */ 1591 case BIOCSETIF: 1592 { 1593 int alloc_buf, size; 1594 1595 /* 1596 * Behavior here depends on the buffering model. If 1597 * we're using kernel memory buffers, then we can 1598 * allocate them here. If we're using zero-copy, 1599 * then the user process must have registered buffers 1600 * by the time we get here. 1601 */ 1602 alloc_buf = 0; 1603 BPFD_LOCK(d); 1604 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1605 d->bd_sbuf == NULL) 1606 alloc_buf = 1; 1607 BPFD_UNLOCK(d); 1608 if (alloc_buf) { 1609 size = d->bd_bufsize; 1610 error = bpf_buffer_ioctl_sblen(d, &size); 1611 if (error != 0) 1612 break; 1613 } 1614 BPF_LOCK(); 1615 error = bpf_setif(d, (struct ifreq *)addr); 1616 BPF_UNLOCK(); 1617 break; 1618 } 1619 1620 /* 1621 * Set read timeout. 1622 */ 1623 case BIOCSRTIMEOUT: 1624 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1625 case BIOCSRTIMEOUT32: 1626 #endif 1627 { 1628 struct timeval *tv = (struct timeval *)addr; 1629 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1630 struct timeval32 *tv32; 1631 struct timeval tv64; 1632 1633 if (cmd == BIOCSRTIMEOUT32) { 1634 tv32 = (struct timeval32 *)addr; 1635 tv = &tv64; 1636 tv->tv_sec = tv32->tv_sec; 1637 tv->tv_usec = tv32->tv_usec; 1638 } else 1639 #endif 1640 tv = (struct timeval *)addr; 1641 1642 /* 1643 * Subtract 1 tick from tvtohz() since this isn't 1644 * a one-shot timer. 1645 */ 1646 if ((error = itimerfix(tv)) == 0) 1647 d->bd_rtout = tvtohz(tv) - 1; 1648 break; 1649 } 1650 1651 /* 1652 * Get read timeout. 1653 */ 1654 case BIOCGRTIMEOUT: 1655 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1656 case BIOCGRTIMEOUT32: 1657 #endif 1658 { 1659 struct timeval *tv; 1660 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1661 struct timeval32 *tv32; 1662 struct timeval tv64; 1663 1664 if (cmd == BIOCGRTIMEOUT32) 1665 tv = &tv64; 1666 else 1667 #endif 1668 tv = (struct timeval *)addr; 1669 1670 tv->tv_sec = d->bd_rtout / hz; 1671 tv->tv_usec = (d->bd_rtout % hz) * tick; 1672 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1673 if (cmd == BIOCGRTIMEOUT32) { 1674 tv32 = (struct timeval32 *)addr; 1675 tv32->tv_sec = tv->tv_sec; 1676 tv32->tv_usec = tv->tv_usec; 1677 } 1678 #endif 1679 1680 break; 1681 } 1682 1683 /* 1684 * Get packet stats. 1685 */ 1686 case BIOCGSTATS: 1687 { 1688 struct bpf_stat *bs = (struct bpf_stat *)addr; 1689 1690 /* XXXCSJP overflow */ 1691 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1692 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1693 break; 1694 } 1695 1696 /* 1697 * Set immediate mode. 1698 */ 1699 case BIOCIMMEDIATE: 1700 BPFD_LOCK(d); 1701 d->bd_immediate = *(u_int *)addr; 1702 BPFD_UNLOCK(d); 1703 break; 1704 1705 case BIOCVERSION: 1706 { 1707 struct bpf_version *bv = (struct bpf_version *)addr; 1708 1709 bv->bv_major = BPF_MAJOR_VERSION; 1710 bv->bv_minor = BPF_MINOR_VERSION; 1711 break; 1712 } 1713 1714 /* 1715 * Get "header already complete" flag 1716 */ 1717 case BIOCGHDRCMPLT: 1718 BPFD_LOCK(d); 1719 *(u_int *)addr = d->bd_hdrcmplt; 1720 BPFD_UNLOCK(d); 1721 break; 1722 1723 /* 1724 * Set "header already complete" flag 1725 */ 1726 case BIOCSHDRCMPLT: 1727 BPFD_LOCK(d); 1728 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1729 BPFD_UNLOCK(d); 1730 break; 1731 1732 /* 1733 * Get packet direction flag 1734 */ 1735 case BIOCGDIRECTION: 1736 BPFD_LOCK(d); 1737 *(u_int *)addr = d->bd_direction; 1738 BPFD_UNLOCK(d); 1739 break; 1740 1741 /* 1742 * Set packet direction flag 1743 */ 1744 case BIOCSDIRECTION: 1745 { 1746 u_int direction; 1747 1748 direction = *(u_int *)addr; 1749 switch (direction) { 1750 case BPF_D_IN: 1751 case BPF_D_INOUT: 1752 case BPF_D_OUT: 1753 BPFD_LOCK(d); 1754 d->bd_direction = direction; 1755 BPFD_UNLOCK(d); 1756 break; 1757 default: 1758 error = EINVAL; 1759 } 1760 } 1761 break; 1762 1763 /* 1764 * Get packet timestamp format and resolution. 1765 */ 1766 case BIOCGTSTAMP: 1767 BPFD_LOCK(d); 1768 *(u_int *)addr = d->bd_tstamp; 1769 BPFD_UNLOCK(d); 1770 break; 1771 1772 /* 1773 * Set packet timestamp format and resolution. 1774 */ 1775 case BIOCSTSTAMP: 1776 { 1777 u_int func; 1778 1779 func = *(u_int *)addr; 1780 if (BPF_T_VALID(func)) 1781 d->bd_tstamp = func; 1782 else 1783 error = EINVAL; 1784 } 1785 break; 1786 1787 case BIOCFEEDBACK: 1788 BPFD_LOCK(d); 1789 d->bd_feedback = *(u_int *)addr; 1790 BPFD_UNLOCK(d); 1791 break; 1792 1793 case BIOCLOCK: 1794 BPFD_LOCK(d); 1795 d->bd_locked = 1; 1796 BPFD_UNLOCK(d); 1797 break; 1798 1799 case FIONBIO: /* Non-blocking I/O */ 1800 break; 1801 1802 case FIOASYNC: /* Send signal on receive packets */ 1803 BPFD_LOCK(d); 1804 d->bd_async = *(int *)addr; 1805 BPFD_UNLOCK(d); 1806 break; 1807 1808 case FIOSETOWN: 1809 /* 1810 * XXX: Add some sort of locking here? 1811 * fsetown() can sleep. 1812 */ 1813 error = fsetown(*(int *)addr, &d->bd_sigio); 1814 break; 1815 1816 case FIOGETOWN: 1817 BPFD_LOCK(d); 1818 *(int *)addr = fgetown(&d->bd_sigio); 1819 BPFD_UNLOCK(d); 1820 break; 1821 1822 /* This is deprecated, FIOSETOWN should be used instead. */ 1823 case TIOCSPGRP: 1824 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1825 break; 1826 1827 /* This is deprecated, FIOGETOWN should be used instead. */ 1828 case TIOCGPGRP: 1829 *(int *)addr = -fgetown(&d->bd_sigio); 1830 break; 1831 1832 case BIOCSRSIG: /* Set receive signal */ 1833 { 1834 u_int sig; 1835 1836 sig = *(u_int *)addr; 1837 1838 if (sig >= NSIG) 1839 error = EINVAL; 1840 else { 1841 BPFD_LOCK(d); 1842 d->bd_sig = sig; 1843 BPFD_UNLOCK(d); 1844 } 1845 break; 1846 } 1847 case BIOCGRSIG: 1848 BPFD_LOCK(d); 1849 *(u_int *)addr = d->bd_sig; 1850 BPFD_UNLOCK(d); 1851 break; 1852 1853 case BIOCGETBUFMODE: 1854 BPFD_LOCK(d); 1855 *(u_int *)addr = d->bd_bufmode; 1856 BPFD_UNLOCK(d); 1857 break; 1858 1859 case BIOCSETBUFMODE: 1860 /* 1861 * Allow the buffering mode to be changed as long as we 1862 * haven't yet committed to a particular mode. Our 1863 * definition of commitment, for now, is whether or not a 1864 * buffer has been allocated or an interface attached, since 1865 * that's the point where things get tricky. 1866 */ 1867 switch (*(u_int *)addr) { 1868 case BPF_BUFMODE_BUFFER: 1869 break; 1870 1871 case BPF_BUFMODE_ZBUF: 1872 if (bpf_zerocopy_enable) 1873 break; 1874 /* FALLSTHROUGH */ 1875 1876 default: 1877 CURVNET_RESTORE(); 1878 return (EINVAL); 1879 } 1880 1881 BPFD_LOCK(d); 1882 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1883 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1884 BPFD_UNLOCK(d); 1885 CURVNET_RESTORE(); 1886 return (EBUSY); 1887 } 1888 d->bd_bufmode = *(u_int *)addr; 1889 BPFD_UNLOCK(d); 1890 break; 1891 1892 case BIOCGETZMAX: 1893 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1894 break; 1895 1896 case BIOCSETZBUF: 1897 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1898 break; 1899 1900 case BIOCROTZBUF: 1901 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1902 break; 1903 } 1904 CURVNET_RESTORE(); 1905 return (error); 1906 } 1907 1908 /* 1909 * Set d's packet filter program to fp. If this file already has a filter, 1910 * free it and replace it. Returns EINVAL for bogus requests. 1911 * 1912 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1913 * calls. 1914 */ 1915 static int 1916 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1917 { 1918 #ifdef COMPAT_FREEBSD32 1919 struct bpf_program fp_swab; 1920 struct bpf_program32 *fp32; 1921 #endif 1922 struct bpf_program_buffer *fcode; 1923 struct bpf_insn *filter; 1924 #ifdef BPF_JITTER 1925 bpf_jit_filter *jfunc; 1926 #endif 1927 size_t size; 1928 u_int flen; 1929 bool track_event; 1930 1931 #ifdef COMPAT_FREEBSD32 1932 switch (cmd) { 1933 case BIOCSETF32: 1934 case BIOCSETWF32: 1935 case BIOCSETFNR32: 1936 fp32 = (struct bpf_program32 *)fp; 1937 fp_swab.bf_len = fp32->bf_len; 1938 fp_swab.bf_insns = 1939 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1940 fp = &fp_swab; 1941 switch (cmd) { 1942 case BIOCSETF32: 1943 cmd = BIOCSETF; 1944 break; 1945 case BIOCSETWF32: 1946 cmd = BIOCSETWF; 1947 break; 1948 } 1949 break; 1950 } 1951 #endif 1952 1953 filter = NULL; 1954 #ifdef BPF_JITTER 1955 jfunc = NULL; 1956 #endif 1957 /* 1958 * Check new filter validness before acquiring any locks. 1959 * Allocate memory for new filter, if needed. 1960 */ 1961 flen = fp->bf_len; 1962 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1963 return (EINVAL); 1964 size = flen * sizeof(*fp->bf_insns); 1965 if (size > 0) { 1966 /* We're setting up new filter. Copy and check actual data. */ 1967 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1968 filter = (struct bpf_insn *)fcode->buffer; 1969 if (copyin(fp->bf_insns, filter, size) != 0 || 1970 !bpf_validate(filter, flen)) { 1971 free(fcode, M_BPF); 1972 return (EINVAL); 1973 } 1974 #ifdef BPF_JITTER 1975 if (cmd != BIOCSETWF) { 1976 /* 1977 * Filter is copied inside fcode and is 1978 * perfectly valid. 1979 */ 1980 jfunc = bpf_jitter(filter, flen); 1981 } 1982 #endif 1983 } 1984 1985 track_event = false; 1986 fcode = NULL; 1987 1988 BPF_LOCK(); 1989 BPFD_LOCK(d); 1990 /* Set up new filter. */ 1991 if (cmd == BIOCSETWF) { 1992 if (d->bd_wfilter != NULL) { 1993 fcode = __containerof((void *)d->bd_wfilter, 1994 struct bpf_program_buffer, buffer); 1995 #ifdef BPF_JITTER 1996 fcode->func = NULL; 1997 #endif 1998 } 1999 d->bd_wfilter = filter; 2000 } else { 2001 if (d->bd_rfilter != NULL) { 2002 fcode = __containerof((void *)d->bd_rfilter, 2003 struct bpf_program_buffer, buffer); 2004 #ifdef BPF_JITTER 2005 fcode->func = d->bd_bfilter; 2006 #endif 2007 } 2008 d->bd_rfilter = filter; 2009 #ifdef BPF_JITTER 2010 d->bd_bfilter = jfunc; 2011 #endif 2012 if (cmd == BIOCSETF) 2013 reset_d(d); 2014 2015 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 2016 /* 2017 * Filter can be set several times without 2018 * specifying interface. In this case just mark d 2019 * as reader. 2020 */ 2021 d->bd_writer = 0; 2022 if (d->bd_bif != NULL) { 2023 /* 2024 * Remove descriptor from writers-only list 2025 * and add it to active readers list. 2026 */ 2027 CK_LIST_REMOVE(d, bd_next); 2028 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 2029 d, bd_next); 2030 CTR2(KTR_NET, 2031 "%s: upgrade required by pid %d", 2032 __func__, d->bd_pid); 2033 track_event = true; 2034 } 2035 } 2036 } 2037 BPFD_UNLOCK(d); 2038 2039 if (fcode != NULL) 2040 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 2041 2042 if (track_event) 2043 EVENTHANDLER_INVOKE(bpf_track, 2044 d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); 2045 2046 BPF_UNLOCK(); 2047 return (0); 2048 } 2049 2050 /* 2051 * Detach a file from its current interface (if attached at all) and attach 2052 * to the interface indicated by the name stored in ifr. 2053 * Return an errno or 0. 2054 */ 2055 static int 2056 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 2057 { 2058 struct bpf_if *bp; 2059 struct ifnet *theywant; 2060 2061 BPF_LOCK_ASSERT(); 2062 2063 theywant = ifunit(ifr->ifr_name); 2064 if (theywant == NULL || theywant->if_bpf == NULL) 2065 return (ENXIO); 2066 2067 bp = theywant->if_bpf; 2068 /* 2069 * At this point, we expect the buffer is already allocated. If not, 2070 * return an error. 2071 */ 2072 switch (d->bd_bufmode) { 2073 case BPF_BUFMODE_BUFFER: 2074 case BPF_BUFMODE_ZBUF: 2075 if (d->bd_sbuf == NULL) 2076 return (EINVAL); 2077 break; 2078 2079 default: 2080 panic("bpf_setif: bufmode %d", d->bd_bufmode); 2081 } 2082 if (bp != d->bd_bif) 2083 bpf_attachd(d, bp); 2084 else { 2085 BPFD_LOCK(d); 2086 reset_d(d); 2087 BPFD_UNLOCK(d); 2088 } 2089 return (0); 2090 } 2091 2092 /* 2093 * Support for select() and poll() system calls 2094 * 2095 * Return true iff the specific operation will not block indefinitely. 2096 * Otherwise, return false but make a note that a selwakeup() must be done. 2097 */ 2098 static int 2099 bpfpoll(struct cdev *dev, int events, struct thread *td) 2100 { 2101 struct bpf_d *d; 2102 int revents; 2103 2104 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2105 return (events & 2106 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 2107 2108 /* 2109 * Refresh PID associated with this descriptor. 2110 */ 2111 revents = events & (POLLOUT | POLLWRNORM); 2112 BPFD_LOCK(d); 2113 BPF_PID_REFRESH(d, td); 2114 if (events & (POLLIN | POLLRDNORM)) { 2115 if (bpf_ready(d)) 2116 revents |= events & (POLLIN | POLLRDNORM); 2117 else { 2118 selrecord(td, &d->bd_sel); 2119 /* Start the read timeout if necessary. */ 2120 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2121 callout_reset(&d->bd_callout, d->bd_rtout, 2122 bpf_timed_out, d); 2123 d->bd_state = BPF_WAITING; 2124 } 2125 } 2126 } 2127 BPFD_UNLOCK(d); 2128 return (revents); 2129 } 2130 2131 /* 2132 * Support for kevent() system call. Register EVFILT_READ filters and 2133 * reject all others. 2134 */ 2135 int 2136 bpfkqfilter(struct cdev *dev, struct knote *kn) 2137 { 2138 struct bpf_d *d; 2139 2140 if (devfs_get_cdevpriv((void **)&d) != 0 || 2141 kn->kn_filter != EVFILT_READ) 2142 return (1); 2143 2144 /* 2145 * Refresh PID associated with this descriptor. 2146 */ 2147 BPFD_LOCK(d); 2148 BPF_PID_REFRESH_CUR(d); 2149 kn->kn_fop = &bpfread_filtops; 2150 kn->kn_hook = d; 2151 knlist_add(&d->bd_sel.si_note, kn, 1); 2152 BPFD_UNLOCK(d); 2153 2154 return (0); 2155 } 2156 2157 static void 2158 filt_bpfdetach(struct knote *kn) 2159 { 2160 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2161 2162 knlist_remove(&d->bd_sel.si_note, kn, 0); 2163 } 2164 2165 static int 2166 filt_bpfread(struct knote *kn, long hint) 2167 { 2168 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2169 int ready; 2170 2171 BPFD_LOCK_ASSERT(d); 2172 ready = bpf_ready(d); 2173 if (ready) { 2174 kn->kn_data = d->bd_slen; 2175 /* 2176 * Ignore the hold buffer if it is being copied to user space. 2177 */ 2178 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2179 kn->kn_data += d->bd_hlen; 2180 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2181 callout_reset(&d->bd_callout, d->bd_rtout, 2182 bpf_timed_out, d); 2183 d->bd_state = BPF_WAITING; 2184 } 2185 2186 return (ready); 2187 } 2188 2189 #define BPF_TSTAMP_NONE 0 2190 #define BPF_TSTAMP_FAST 1 2191 #define BPF_TSTAMP_NORMAL 2 2192 #define BPF_TSTAMP_EXTERN 3 2193 2194 static int 2195 bpf_ts_quality(int tstype) 2196 { 2197 2198 if (tstype == BPF_T_NONE) 2199 return (BPF_TSTAMP_NONE); 2200 if ((tstype & BPF_T_FAST) != 0) 2201 return (BPF_TSTAMP_FAST); 2202 2203 return (BPF_TSTAMP_NORMAL); 2204 } 2205 2206 static int 2207 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2208 { 2209 struct m_tag *tag; 2210 int quality; 2211 2212 quality = bpf_ts_quality(tstype); 2213 if (quality == BPF_TSTAMP_NONE) 2214 return (quality); 2215 2216 if (m != NULL) { 2217 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2218 if (tag != NULL) { 2219 *bt = *(struct bintime *)(tag + 1); 2220 return (BPF_TSTAMP_EXTERN); 2221 } 2222 } 2223 if (quality == BPF_TSTAMP_NORMAL) 2224 binuptime(bt); 2225 else 2226 getbinuptime(bt); 2227 2228 return (quality); 2229 } 2230 2231 /* 2232 * Incoming linkage from device drivers. Process the packet pkt, of length 2233 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2234 * by each process' filter, and if accepted, stashed into the corresponding 2235 * buffer. 2236 */ 2237 void 2238 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2239 { 2240 struct epoch_tracker et; 2241 struct bintime bt; 2242 struct bpf_d *d; 2243 #ifdef BPF_JITTER 2244 bpf_jit_filter *bf; 2245 #endif 2246 u_int slen; 2247 int gottime; 2248 2249 gottime = BPF_TSTAMP_NONE; 2250 NET_EPOCH_ENTER(et); 2251 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2252 counter_u64_add(d->bd_rcount, 1); 2253 /* 2254 * NB: We dont call BPF_CHECK_DIRECTION() here since there 2255 * is no way for the caller to indiciate to us whether this 2256 * packet is inbound or outbound. In the bpf_mtap() routines, 2257 * we use the interface pointers on the mbuf to figure it out. 2258 */ 2259 #ifdef BPF_JITTER 2260 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2261 if (bf != NULL) 2262 slen = (*(bf->func))(pkt, pktlen, pktlen); 2263 else 2264 #endif 2265 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2266 if (slen != 0) { 2267 /* 2268 * Filter matches. Let's to acquire write lock. 2269 */ 2270 BPFD_LOCK(d); 2271 counter_u64_add(d->bd_fcount, 1); 2272 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2273 gottime = bpf_gettime(&bt, d->bd_tstamp, 2274 NULL); 2275 #ifdef MAC 2276 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2277 #endif 2278 catchpacket(d, pkt, pktlen, slen, 2279 bpf_append_bytes, &bt); 2280 BPFD_UNLOCK(d); 2281 } 2282 } 2283 NET_EPOCH_EXIT(et); 2284 } 2285 2286 #define BPF_CHECK_DIRECTION(d, r, i) \ 2287 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2288 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2289 2290 /* 2291 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2292 * Locking model is explained in bpf_tap(). 2293 */ 2294 void 2295 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2296 { 2297 struct epoch_tracker et; 2298 struct bintime bt; 2299 struct bpf_d *d; 2300 #ifdef BPF_JITTER 2301 bpf_jit_filter *bf; 2302 #endif 2303 u_int pktlen, slen; 2304 int gottime; 2305 2306 /* Skip outgoing duplicate packets. */ 2307 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2308 m->m_flags &= ~M_PROMISC; 2309 return; 2310 } 2311 2312 pktlen = m_length(m, NULL); 2313 gottime = BPF_TSTAMP_NONE; 2314 2315 NET_EPOCH_ENTER(et); 2316 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2317 if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) 2318 continue; 2319 counter_u64_add(d->bd_rcount, 1); 2320 #ifdef BPF_JITTER 2321 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2322 /* XXX We cannot handle multiple mbufs. */ 2323 if (bf != NULL && m->m_next == NULL) 2324 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2325 pktlen); 2326 else 2327 #endif 2328 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2329 if (slen != 0) { 2330 BPFD_LOCK(d); 2331 2332 counter_u64_add(d->bd_fcount, 1); 2333 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2334 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2335 #ifdef MAC 2336 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2337 #endif 2338 catchpacket(d, (u_char *)m, pktlen, slen, 2339 bpf_append_mbuf, &bt); 2340 BPFD_UNLOCK(d); 2341 } 2342 } 2343 NET_EPOCH_EXIT(et); 2344 } 2345 2346 /* 2347 * Incoming linkage from device drivers, when packet is in 2348 * an mbuf chain and to be prepended by a contiguous header. 2349 */ 2350 void 2351 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2352 { 2353 struct epoch_tracker et; 2354 struct bintime bt; 2355 struct mbuf mb; 2356 struct bpf_d *d; 2357 u_int pktlen, slen; 2358 int gottime; 2359 2360 /* Skip outgoing duplicate packets. */ 2361 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2362 m->m_flags &= ~M_PROMISC; 2363 return; 2364 } 2365 2366 pktlen = m_length(m, NULL); 2367 /* 2368 * Craft on-stack mbuf suitable for passing to bpf_filter. 2369 * Note that we cut corners here; we only setup what's 2370 * absolutely needed--this mbuf should never go anywhere else. 2371 */ 2372 mb.m_flags = 0; 2373 mb.m_next = m; 2374 mb.m_data = data; 2375 mb.m_len = dlen; 2376 pktlen += dlen; 2377 2378 gottime = BPF_TSTAMP_NONE; 2379 2380 NET_EPOCH_ENTER(et); 2381 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2382 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2383 continue; 2384 counter_u64_add(d->bd_rcount, 1); 2385 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2386 if (slen != 0) { 2387 BPFD_LOCK(d); 2388 2389 counter_u64_add(d->bd_fcount, 1); 2390 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2391 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2392 #ifdef MAC 2393 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2394 #endif 2395 catchpacket(d, (u_char *)&mb, pktlen, slen, 2396 bpf_append_mbuf, &bt); 2397 BPFD_UNLOCK(d); 2398 } 2399 } 2400 NET_EPOCH_EXIT(et); 2401 } 2402 2403 #undef BPF_CHECK_DIRECTION 2404 #undef BPF_TSTAMP_NONE 2405 #undef BPF_TSTAMP_FAST 2406 #undef BPF_TSTAMP_NORMAL 2407 #undef BPF_TSTAMP_EXTERN 2408 2409 static int 2410 bpf_hdrlen(struct bpf_d *d) 2411 { 2412 int hdrlen; 2413 2414 hdrlen = d->bd_bif->bif_hdrlen; 2415 #ifndef BURN_BRIDGES 2416 if (d->bd_tstamp == BPF_T_NONE || 2417 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2418 #ifdef COMPAT_FREEBSD32 2419 if (d->bd_compat32) 2420 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2421 else 2422 #endif 2423 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2424 else 2425 #endif 2426 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2427 #ifdef COMPAT_FREEBSD32 2428 if (d->bd_compat32) 2429 hdrlen = BPF_WORDALIGN32(hdrlen); 2430 else 2431 #endif 2432 hdrlen = BPF_WORDALIGN(hdrlen); 2433 2434 return (hdrlen - d->bd_bif->bif_hdrlen); 2435 } 2436 2437 static void 2438 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2439 { 2440 struct bintime bt2, boottimebin; 2441 struct timeval tsm; 2442 struct timespec tsn; 2443 2444 if ((tstype & BPF_T_MONOTONIC) == 0) { 2445 bt2 = *bt; 2446 getboottimebin(&boottimebin); 2447 bintime_add(&bt2, &boottimebin); 2448 bt = &bt2; 2449 } 2450 switch (BPF_T_FORMAT(tstype)) { 2451 case BPF_T_MICROTIME: 2452 bintime2timeval(bt, &tsm); 2453 ts->bt_sec = tsm.tv_sec; 2454 ts->bt_frac = tsm.tv_usec; 2455 break; 2456 case BPF_T_NANOTIME: 2457 bintime2timespec(bt, &tsn); 2458 ts->bt_sec = tsn.tv_sec; 2459 ts->bt_frac = tsn.tv_nsec; 2460 break; 2461 case BPF_T_BINTIME: 2462 ts->bt_sec = bt->sec; 2463 ts->bt_frac = bt->frac; 2464 break; 2465 } 2466 } 2467 2468 /* 2469 * Move the packet data from interface memory (pkt) into the 2470 * store buffer. "cpfn" is the routine called to do the actual data 2471 * transfer. bcopy is passed in to copy contiguous chunks, while 2472 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2473 * pkt is really an mbuf. 2474 */ 2475 static void 2476 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2477 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2478 struct bintime *bt) 2479 { 2480 struct bpf_xhdr hdr; 2481 #ifndef BURN_BRIDGES 2482 struct bpf_hdr hdr_old; 2483 #ifdef COMPAT_FREEBSD32 2484 struct bpf_hdr32 hdr32_old; 2485 #endif 2486 #endif 2487 int caplen, curlen, hdrlen, totlen; 2488 int do_wakeup = 0; 2489 int do_timestamp; 2490 int tstype; 2491 2492 BPFD_LOCK_ASSERT(d); 2493 if (d->bd_bif == NULL) { 2494 /* Descriptor was detached in concurrent thread */ 2495 counter_u64_add(d->bd_dcount, 1); 2496 return; 2497 } 2498 2499 /* 2500 * Detect whether user space has released a buffer back to us, and if 2501 * so, move it from being a hold buffer to a free buffer. This may 2502 * not be the best place to do it (for example, we might only want to 2503 * run this check if we need the space), but for now it's a reliable 2504 * spot to do it. 2505 */ 2506 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2507 d->bd_fbuf = d->bd_hbuf; 2508 d->bd_hbuf = NULL; 2509 d->bd_hlen = 0; 2510 bpf_buf_reclaimed(d); 2511 } 2512 2513 /* 2514 * Figure out how many bytes to move. If the packet is 2515 * greater or equal to the snapshot length, transfer that 2516 * much. Otherwise, transfer the whole packet (unless 2517 * we hit the buffer size limit). 2518 */ 2519 hdrlen = bpf_hdrlen(d); 2520 totlen = hdrlen + min(snaplen, pktlen); 2521 if (totlen > d->bd_bufsize) 2522 totlen = d->bd_bufsize; 2523 2524 /* 2525 * Round up the end of the previous packet to the next longword. 2526 * 2527 * Drop the packet if there's no room and no hope of room 2528 * If the packet would overflow the storage buffer or the storage 2529 * buffer is considered immutable by the buffer model, try to rotate 2530 * the buffer and wakeup pending processes. 2531 */ 2532 #ifdef COMPAT_FREEBSD32 2533 if (d->bd_compat32) 2534 curlen = BPF_WORDALIGN32(d->bd_slen); 2535 else 2536 #endif 2537 curlen = BPF_WORDALIGN(d->bd_slen); 2538 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2539 if (d->bd_fbuf == NULL) { 2540 /* 2541 * There's no room in the store buffer, and no 2542 * prospect of room, so drop the packet. Notify the 2543 * buffer model. 2544 */ 2545 bpf_buffull(d); 2546 counter_u64_add(d->bd_dcount, 1); 2547 return; 2548 } 2549 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2550 ROTATE_BUFFERS(d); 2551 do_wakeup = 1; 2552 curlen = 0; 2553 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2554 /* 2555 * Immediate mode is set, or the read timeout has already 2556 * expired during a select call. A packet arrived, so the 2557 * reader should be woken up. 2558 */ 2559 do_wakeup = 1; 2560 caplen = totlen - hdrlen; 2561 tstype = d->bd_tstamp; 2562 do_timestamp = tstype != BPF_T_NONE; 2563 #ifndef BURN_BRIDGES 2564 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2565 struct bpf_ts ts; 2566 if (do_timestamp) 2567 bpf_bintime2ts(bt, &ts, tstype); 2568 #ifdef COMPAT_FREEBSD32 2569 if (d->bd_compat32) { 2570 bzero(&hdr32_old, sizeof(hdr32_old)); 2571 if (do_timestamp) { 2572 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2573 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2574 } 2575 hdr32_old.bh_datalen = pktlen; 2576 hdr32_old.bh_hdrlen = hdrlen; 2577 hdr32_old.bh_caplen = caplen; 2578 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2579 sizeof(hdr32_old)); 2580 goto copy; 2581 } 2582 #endif 2583 bzero(&hdr_old, sizeof(hdr_old)); 2584 if (do_timestamp) { 2585 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2586 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2587 } 2588 hdr_old.bh_datalen = pktlen; 2589 hdr_old.bh_hdrlen = hdrlen; 2590 hdr_old.bh_caplen = caplen; 2591 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2592 sizeof(hdr_old)); 2593 goto copy; 2594 } 2595 #endif 2596 2597 /* 2598 * Append the bpf header. Note we append the actual header size, but 2599 * move forward the length of the header plus padding. 2600 */ 2601 bzero(&hdr, sizeof(hdr)); 2602 if (do_timestamp) 2603 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2604 hdr.bh_datalen = pktlen; 2605 hdr.bh_hdrlen = hdrlen; 2606 hdr.bh_caplen = caplen; 2607 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2608 2609 /* 2610 * Copy the packet data into the store buffer and update its length. 2611 */ 2612 #ifndef BURN_BRIDGES 2613 copy: 2614 #endif 2615 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2616 d->bd_slen = curlen + totlen; 2617 2618 if (do_wakeup) 2619 bpf_wakeup(d); 2620 } 2621 2622 /* 2623 * Free buffers currently in use by a descriptor. 2624 * Called on close. 2625 */ 2626 static void 2627 bpfd_free(epoch_context_t ctx) 2628 { 2629 struct bpf_d *d; 2630 struct bpf_program_buffer *p; 2631 2632 /* 2633 * We don't need to lock out interrupts since this descriptor has 2634 * been detached from its interface and it yet hasn't been marked 2635 * free. 2636 */ 2637 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2638 bpf_free(d); 2639 if (d->bd_rfilter != NULL) { 2640 p = __containerof((void *)d->bd_rfilter, 2641 struct bpf_program_buffer, buffer); 2642 #ifdef BPF_JITTER 2643 p->func = d->bd_bfilter; 2644 #endif 2645 bpf_program_buffer_free(&p->epoch_ctx); 2646 } 2647 if (d->bd_wfilter != NULL) { 2648 p = __containerof((void *)d->bd_wfilter, 2649 struct bpf_program_buffer, buffer); 2650 #ifdef BPF_JITTER 2651 p->func = NULL; 2652 #endif 2653 bpf_program_buffer_free(&p->epoch_ctx); 2654 } 2655 2656 mtx_destroy(&d->bd_lock); 2657 counter_u64_free(d->bd_rcount); 2658 counter_u64_free(d->bd_dcount); 2659 counter_u64_free(d->bd_fcount); 2660 counter_u64_free(d->bd_wcount); 2661 counter_u64_free(d->bd_wfcount); 2662 counter_u64_free(d->bd_wdcount); 2663 counter_u64_free(d->bd_zcopy); 2664 free(d, M_BPF); 2665 } 2666 2667 /* 2668 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2669 * fixed size of the link header (variable length headers not yet supported). 2670 */ 2671 void 2672 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2673 { 2674 2675 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2676 } 2677 2678 /* 2679 * Attach an interface to bpf. ifp is a pointer to the structure 2680 * defining the interface to be attached, dlt is the link layer type, 2681 * and hdrlen is the fixed size of the link header (variable length 2682 * headers are not yet supporrted). 2683 */ 2684 void 2685 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, 2686 struct bpf_if **driverp) 2687 { 2688 struct bpf_if *bp; 2689 2690 KASSERT(*driverp == NULL, 2691 ("bpfattach2: driverp already initialized")); 2692 2693 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2694 2695 CK_LIST_INIT(&bp->bif_dlist); 2696 CK_LIST_INIT(&bp->bif_wlist); 2697 bp->bif_ifp = ifp; 2698 bp->bif_dlt = dlt; 2699 bp->bif_hdrlen = hdrlen; 2700 bp->bif_bpf = driverp; 2701 bp->bif_refcnt = 1; 2702 *driverp = bp; 2703 /* 2704 * Reference ifnet pointer, so it won't freed until 2705 * we release it. 2706 */ 2707 if_ref(ifp); 2708 BPF_LOCK(); 2709 CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2710 BPF_UNLOCK(); 2711 2712 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2713 if_printf(ifp, "bpf attached\n"); 2714 } 2715 2716 #ifdef VIMAGE 2717 /* 2718 * When moving interfaces between vnet instances we need a way to 2719 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2720 * after the vmove. We unfortunately have no device driver infrastructure 2721 * to query the interface for these values after creation/attach, thus 2722 * add this as a workaround. 2723 */ 2724 int 2725 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2726 { 2727 2728 if (bp == NULL) 2729 return (ENXIO); 2730 if (bif_dlt == NULL && bif_hdrlen == NULL) 2731 return (0); 2732 2733 if (bif_dlt != NULL) 2734 *bif_dlt = bp->bif_dlt; 2735 if (bif_hdrlen != NULL) 2736 *bif_hdrlen = bp->bif_hdrlen; 2737 2738 return (0); 2739 } 2740 #endif 2741 2742 /* 2743 * Detach bpf from an interface. This involves detaching each descriptor 2744 * associated with the interface. Notify each descriptor as it's detached 2745 * so that any sleepers wake up and get ENXIO. 2746 */ 2747 void 2748 bpfdetach(struct ifnet *ifp) 2749 { 2750 struct bpf_if *bp, *bp_temp; 2751 struct bpf_d *d; 2752 2753 BPF_LOCK(); 2754 /* Find all bpf_if struct's which reference ifp and detach them. */ 2755 CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2756 if (ifp != bp->bif_ifp) 2757 continue; 2758 2759 CK_LIST_REMOVE(bp, bif_next); 2760 *bp->bif_bpf = (struct bpf_if *)&dead_bpf_if; 2761 2762 CTR4(KTR_NET, 2763 "%s: sheduling free for encap %d (%p) for if %p", 2764 __func__, bp->bif_dlt, bp, ifp); 2765 2766 /* Detach common descriptors */ 2767 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2768 bpf_detachd_locked(d, true); 2769 } 2770 2771 /* Detach writer-only descriptors */ 2772 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2773 bpf_detachd_locked(d, true); 2774 } 2775 bpfif_rele(bp); 2776 } 2777 BPF_UNLOCK(); 2778 } 2779 2780 /* 2781 * Get a list of available data link type of the interface. 2782 */ 2783 static int 2784 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2785 { 2786 struct ifnet *ifp; 2787 struct bpf_if *bp; 2788 u_int *lst; 2789 int error, n, n1; 2790 2791 BPF_LOCK_ASSERT(); 2792 2793 ifp = d->bd_bif->bif_ifp; 2794 n1 = 0; 2795 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2796 if (bp->bif_ifp == ifp) 2797 n1++; 2798 } 2799 if (bfl->bfl_list == NULL) { 2800 bfl->bfl_len = n1; 2801 return (0); 2802 } 2803 if (n1 > bfl->bfl_len) 2804 return (ENOMEM); 2805 2806 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2807 n = 0; 2808 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2809 if (bp->bif_ifp != ifp) 2810 continue; 2811 lst[n++] = bp->bif_dlt; 2812 } 2813 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2814 free(lst, M_TEMP); 2815 bfl->bfl_len = n; 2816 return (error); 2817 } 2818 2819 /* 2820 * Set the data link type of a BPF instance. 2821 */ 2822 static int 2823 bpf_setdlt(struct bpf_d *d, u_int dlt) 2824 { 2825 int error, opromisc; 2826 struct ifnet *ifp; 2827 struct bpf_if *bp; 2828 2829 BPF_LOCK_ASSERT(); 2830 MPASS(d->bd_bif != NULL); 2831 2832 /* 2833 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2834 * changed while we hold global lock. 2835 */ 2836 if (d->bd_bif->bif_dlt == dlt) 2837 return (0); 2838 2839 ifp = d->bd_bif->bif_ifp; 2840 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2841 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2842 break; 2843 } 2844 if (bp == NULL) 2845 return (EINVAL); 2846 2847 opromisc = d->bd_promisc; 2848 bpf_attachd(d, bp); 2849 if (opromisc) { 2850 error = ifpromisc(bp->bif_ifp, 1); 2851 if (error) 2852 if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", 2853 __func__, error); 2854 else 2855 d->bd_promisc = 1; 2856 } 2857 return (0); 2858 } 2859 2860 static void 2861 bpf_drvinit(void *unused) 2862 { 2863 struct cdev *dev; 2864 2865 sx_init(&bpf_sx, "bpf global lock"); 2866 CK_LIST_INIT(&bpf_iflist); 2867 2868 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2869 /* For compatibility */ 2870 make_dev_alias(dev, "bpf0"); 2871 } 2872 2873 /* 2874 * Zero out the various packet counters associated with all of the bpf 2875 * descriptors. At some point, we will probably want to get a bit more 2876 * granular and allow the user to specify descriptors to be zeroed. 2877 */ 2878 static void 2879 bpf_zero_counters(void) 2880 { 2881 struct bpf_if *bp; 2882 struct bpf_d *bd; 2883 2884 BPF_LOCK(); 2885 /* 2886 * We are protected by global lock here, interfaces and 2887 * descriptors can not be deleted while we hold it. 2888 */ 2889 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2890 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2891 counter_u64_zero(bd->bd_rcount); 2892 counter_u64_zero(bd->bd_dcount); 2893 counter_u64_zero(bd->bd_fcount); 2894 counter_u64_zero(bd->bd_wcount); 2895 counter_u64_zero(bd->bd_wfcount); 2896 counter_u64_zero(bd->bd_zcopy); 2897 } 2898 } 2899 BPF_UNLOCK(); 2900 } 2901 2902 /* 2903 * Fill filter statistics 2904 */ 2905 static void 2906 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2907 { 2908 2909 BPF_LOCK_ASSERT(); 2910 bzero(d, sizeof(*d)); 2911 d->bd_structsize = sizeof(*d); 2912 d->bd_immediate = bd->bd_immediate; 2913 d->bd_promisc = bd->bd_promisc; 2914 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2915 d->bd_direction = bd->bd_direction; 2916 d->bd_feedback = bd->bd_feedback; 2917 d->bd_async = bd->bd_async; 2918 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2919 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2920 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2921 d->bd_sig = bd->bd_sig; 2922 d->bd_slen = bd->bd_slen; 2923 d->bd_hlen = bd->bd_hlen; 2924 d->bd_bufsize = bd->bd_bufsize; 2925 d->bd_pid = bd->bd_pid; 2926 strlcpy(d->bd_ifname, 2927 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2928 d->bd_locked = bd->bd_locked; 2929 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2930 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2931 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2932 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2933 d->bd_bufmode = bd->bd_bufmode; 2934 } 2935 2936 /* 2937 * Handle `netstat -B' stats request 2938 */ 2939 static int 2940 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2941 { 2942 static const struct xbpf_d zerostats; 2943 struct xbpf_d *xbdbuf, *xbd, tempstats; 2944 int index, error; 2945 struct bpf_if *bp; 2946 struct bpf_d *bd; 2947 2948 /* 2949 * XXX This is not technically correct. It is possible for non 2950 * privileged users to open bpf devices. It would make sense 2951 * if the users who opened the devices were able to retrieve 2952 * the statistics for them, too. 2953 */ 2954 error = priv_check(req->td, PRIV_NET_BPF); 2955 if (error) 2956 return (error); 2957 /* 2958 * Check to see if the user is requesting that the counters be 2959 * zeroed out. Explicitly check that the supplied data is zeroed, 2960 * as we aren't allowing the user to set the counters currently. 2961 */ 2962 if (req->newptr != NULL) { 2963 if (req->newlen != sizeof(tempstats)) 2964 return (EINVAL); 2965 memset(&tempstats, 0, sizeof(tempstats)); 2966 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2967 if (error) 2968 return (error); 2969 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2970 return (EINVAL); 2971 bpf_zero_counters(); 2972 return (0); 2973 } 2974 if (req->oldptr == NULL) 2975 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2976 if (bpf_bpfd_cnt == 0) 2977 return (SYSCTL_OUT(req, 0, 0)); 2978 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2979 BPF_LOCK(); 2980 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2981 BPF_UNLOCK(); 2982 free(xbdbuf, M_BPF); 2983 return (ENOMEM); 2984 } 2985 index = 0; 2986 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2987 /* Send writers-only first */ 2988 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2989 xbd = &xbdbuf[index++]; 2990 bpfstats_fill_xbpf(xbd, bd); 2991 } 2992 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2993 xbd = &xbdbuf[index++]; 2994 bpfstats_fill_xbpf(xbd, bd); 2995 } 2996 } 2997 BPF_UNLOCK(); 2998 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2999 free(xbdbuf, M_BPF); 3000 return (error); 3001 } 3002 3003 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 3004 3005 #else /* !DEV_BPF && !NETGRAPH_BPF */ 3006 3007 /* 3008 * NOP stubs to allow bpf-using drivers to load and function. 3009 * 3010 * A 'better' implementation would allow the core bpf functionality 3011 * to be loaded at runtime. 3012 */ 3013 3014 void 3015 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3016 { 3017 } 3018 3019 void 3020 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3021 { 3022 } 3023 3024 void 3025 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3026 { 3027 } 3028 3029 void 3030 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3031 { 3032 3033 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3034 } 3035 3036 void 3037 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3038 { 3039 3040 *driverp = (struct bpf_if *)&dead_bpf_if; 3041 } 3042 3043 void 3044 bpfdetach(struct ifnet *ifp) 3045 { 3046 } 3047 3048 u_int 3049 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3050 { 3051 return -1; /* "no filter" behaviour */ 3052 } 3053 3054 int 3055 bpf_validate(const struct bpf_insn *f, int len) 3056 { 3057 return 0; /* false */ 3058 } 3059 3060 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3061 3062 #ifdef DDB 3063 static void 3064 bpf_show_bpf_if(struct bpf_if *bpf_if) 3065 { 3066 3067 if (bpf_if == NULL) 3068 return; 3069 db_printf("%p:\n", bpf_if); 3070 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3071 /* bif_ext.bif_next */ 3072 /* bif_ext.bif_dlist */ 3073 BPF_DB_PRINTF("%#x", bif_dlt); 3074 BPF_DB_PRINTF("%u", bif_hdrlen); 3075 /* bif_wlist */ 3076 BPF_DB_PRINTF("%p", bif_ifp); 3077 BPF_DB_PRINTF("%p", bif_bpf); 3078 BPF_DB_PRINTF("%u", bif_refcnt); 3079 } 3080 3081 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3082 { 3083 3084 if (!have_addr) { 3085 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3086 return; 3087 } 3088 3089 bpf_show_bpf_if((struct bpf_if *)addr); 3090 } 3091 #endif 3092