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 /* Allocate a mbuf for our write, since m_get2 fails if len >= to MJUMPAGESIZE, use m_getjcl for bigger buffers */ 645 if (len < MJUMPAGESIZE) 646 m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR); 647 else if (len <= MJUM9BYTES) 648 m = m_getjcl(M_WAITOK, MT_DATA, M_PKTHDR, MJUM9BYTES); 649 else if (len <= MJUM16BYTES) 650 m = m_getjcl(M_WAITOK, MT_DATA, M_PKTHDR, MJUM16BYTES); 651 else 652 m = NULL; 653 if (m == NULL) 654 return (EIO); 655 m->m_pkthdr.len = m->m_len = len; 656 *mp = m; 657 658 error = uiomove(mtod(m, u_char *), len, uio); 659 if (error) 660 goto bad; 661 662 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 663 if (slen == 0) { 664 error = EPERM; 665 goto bad; 666 } 667 668 /* Check for multicast destination */ 669 switch (linktype) { 670 case DLT_EN10MB: 671 eh = mtod(m, struct ether_header *); 672 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 673 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 674 ETHER_ADDR_LEN) == 0) 675 m->m_flags |= M_BCAST; 676 else 677 m->m_flags |= M_MCAST; 678 } 679 if (d->bd_hdrcmplt == 0) { 680 memcpy(eh->ether_shost, IF_LLADDR(ifp), 681 sizeof(eh->ether_shost)); 682 } 683 break; 684 } 685 686 /* 687 * Make room for link header, and copy it to sockaddr 688 */ 689 if (hlen != 0) { 690 if (sockp->sa_family == AF_IEEE80211) { 691 /* 692 * Collect true length from the parameter header 693 * NB: sockp is known to be zero'd so if we do a 694 * short copy unspecified parameters will be 695 * zero. 696 * NB: packet may not be aligned after stripping 697 * bpf params 698 * XXX check ibp_vers 699 */ 700 p = mtod(m, const struct ieee80211_bpf_params *); 701 hlen = p->ibp_len; 702 if (hlen > sizeof(sockp->sa_data)) { 703 error = EINVAL; 704 goto bad; 705 } 706 } 707 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 708 } 709 *hdrlen = hlen; 710 711 return (0); 712 bad: 713 m_freem(m); 714 return (error); 715 } 716 717 /* 718 * Attach descriptor to the bpf interface, i.e. make d listen on bp, 719 * then reset its buffers and counters with reset_d(). 720 */ 721 static void 722 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 723 { 724 int op_w; 725 726 BPF_LOCK_ASSERT(); 727 728 /* 729 * Save sysctl value to protect from sysctl change 730 * between reads 731 */ 732 op_w = V_bpf_optimize_writers || d->bd_writer; 733 734 if (d->bd_bif != NULL) 735 bpf_detachd_locked(d, false); 736 /* 737 * Point d at bp, and add d to the interface's list. 738 * Since there are many applications using BPF for 739 * sending raw packets only (dhcpd, cdpd are good examples) 740 * we can delay adding d to the list of active listeners until 741 * some filter is configured. 742 */ 743 744 BPFD_LOCK(d); 745 /* 746 * Hold reference to bpif while descriptor uses this interface. 747 */ 748 bpfif_ref(bp); 749 d->bd_bif = bp; 750 if (op_w != 0) { 751 /* Add to writers-only list */ 752 CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 753 /* 754 * We decrement bd_writer on every filter set operation. 755 * First BIOCSETF is done by pcap_open_live() to set up 756 * snap length. After that appliation usually sets its own 757 * filter. 758 */ 759 d->bd_writer = 2; 760 } else 761 CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 762 763 reset_d(d); 764 BPFD_UNLOCK(d); 765 bpf_bpfd_cnt++; 766 767 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 768 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 769 770 if (op_w == 0) 771 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 772 } 773 774 /* 775 * Check if we need to upgrade our descriptor @d from write-only mode. 776 */ 777 static int 778 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 779 int flen) 780 { 781 int is_snap, need_upgrade; 782 783 /* 784 * Check if we've already upgraded or new filter is empty. 785 */ 786 if (d->bd_writer == 0 || fcode == NULL) 787 return (0); 788 789 need_upgrade = 0; 790 791 /* 792 * Check if cmd looks like snaplen setting from 793 * pcap_bpf.c:pcap_open_live(). 794 * Note we're not checking .k value here: 795 * while pcap_open_live() definitely sets to non-zero value, 796 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 797 * do not consider upgrading immediately 798 */ 799 if (cmd == BIOCSETF && flen == 1 && 800 fcode[0].code == (BPF_RET | BPF_K)) 801 is_snap = 1; 802 else 803 is_snap = 0; 804 805 if (is_snap == 0) { 806 /* 807 * We're setting first filter and it doesn't look like 808 * setting snaplen. We're probably using bpf directly. 809 * Upgrade immediately. 810 */ 811 need_upgrade = 1; 812 } else { 813 /* 814 * Do not require upgrade by first BIOCSETF 815 * (used to set snaplen) by pcap_open_live(). 816 */ 817 818 if (--d->bd_writer == 0) { 819 /* 820 * First snaplen filter has already 821 * been set. This is probably catch-all 822 * filter 823 */ 824 need_upgrade = 1; 825 } 826 } 827 828 CTR5(KTR_NET, 829 "%s: filter function set by pid %d, " 830 "bd_writer counter %d, snap %d upgrade %d", 831 __func__, d->bd_pid, d->bd_writer, 832 is_snap, need_upgrade); 833 834 return (need_upgrade); 835 } 836 837 /* 838 * Detach a file from its interface. 839 */ 840 static void 841 bpf_detachd(struct bpf_d *d) 842 { 843 BPF_LOCK(); 844 bpf_detachd_locked(d, false); 845 BPF_UNLOCK(); 846 } 847 848 static void 849 bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) 850 { 851 struct bpf_if *bp; 852 struct ifnet *ifp; 853 int error; 854 855 BPF_LOCK_ASSERT(); 856 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 857 858 /* Check if descriptor is attached */ 859 if ((bp = d->bd_bif) == NULL) 860 return; 861 862 BPFD_LOCK(d); 863 /* Remove d from the interface's descriptor list. */ 864 CK_LIST_REMOVE(d, bd_next); 865 /* Save bd_writer value */ 866 error = d->bd_writer; 867 ifp = bp->bif_ifp; 868 d->bd_bif = NULL; 869 if (detached_ifp) { 870 /* 871 * Notify descriptor as it's detached, so that any 872 * sleepers wake up and get ENXIO. 873 */ 874 bpf_wakeup(d); 875 } 876 BPFD_UNLOCK(d); 877 bpf_bpfd_cnt--; 878 879 /* Call event handler iff d is attached */ 880 if (error == 0) 881 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 882 883 /* 884 * Check if this descriptor had requested promiscuous mode. 885 * If so and ifnet is not detached, turn it off. 886 */ 887 if (d->bd_promisc && !detached_ifp) { 888 d->bd_promisc = 0; 889 CURVNET_SET(ifp->if_vnet); 890 error = ifpromisc(ifp, 0); 891 CURVNET_RESTORE(); 892 if (error != 0 && error != ENXIO) { 893 /* 894 * ENXIO can happen if a pccard is unplugged 895 * Something is really wrong if we were able to put 896 * the driver into promiscuous mode, but can't 897 * take it out. 898 */ 899 if_printf(bp->bif_ifp, 900 "bpf_detach: ifpromisc failed (%d)\n", error); 901 } 902 } 903 bpfif_rele(bp); 904 } 905 906 /* 907 * Close the descriptor by detaching it from its interface, 908 * deallocating its buffers, and marking it free. 909 */ 910 static void 911 bpf_dtor(void *data) 912 { 913 struct bpf_d *d = data; 914 915 BPFD_LOCK(d); 916 if (d->bd_state == BPF_WAITING) 917 callout_stop(&d->bd_callout); 918 d->bd_state = BPF_IDLE; 919 BPFD_UNLOCK(d); 920 funsetown(&d->bd_sigio); 921 bpf_detachd(d); 922 #ifdef MAC 923 mac_bpfdesc_destroy(d); 924 #endif /* MAC */ 925 seldrain(&d->bd_sel); 926 knlist_destroy(&d->bd_sel.si_note); 927 callout_drain(&d->bd_callout); 928 bpfd_rele(d); 929 } 930 931 /* 932 * Open ethernet device. Returns ENXIO for illegal minor device number, 933 * EBUSY if file is open by another process. 934 */ 935 /* ARGSUSED */ 936 static int 937 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 938 { 939 struct bpf_d *d; 940 int error; 941 942 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 943 error = devfs_set_cdevpriv(d, bpf_dtor); 944 if (error != 0) { 945 free(d, M_BPF); 946 return (error); 947 } 948 949 /* Setup counters */ 950 d->bd_rcount = counter_u64_alloc(M_WAITOK); 951 d->bd_dcount = counter_u64_alloc(M_WAITOK); 952 d->bd_fcount = counter_u64_alloc(M_WAITOK); 953 d->bd_wcount = counter_u64_alloc(M_WAITOK); 954 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 955 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 956 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 957 958 /* 959 * For historical reasons, perform a one-time initialization call to 960 * the buffer routines, even though we're not yet committed to a 961 * particular buffer method. 962 */ 963 bpf_buffer_init(d); 964 if ((flags & FREAD) == 0) 965 d->bd_writer = 2; 966 d->bd_hbuf_in_use = 0; 967 d->bd_bufmode = BPF_BUFMODE_BUFFER; 968 d->bd_sig = SIGIO; 969 d->bd_direction = BPF_D_INOUT; 970 d->bd_refcnt = 1; 971 BPF_PID_REFRESH(d, td); 972 #ifdef MAC 973 mac_bpfdesc_init(d); 974 mac_bpfdesc_create(td->td_ucred, d); 975 #endif 976 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 977 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 978 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 979 980 return (0); 981 } 982 983 /* 984 * bpfread - read next chunk of packets from buffers 985 */ 986 static int 987 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 988 { 989 struct bpf_d *d; 990 int error; 991 int non_block; 992 int timed_out; 993 994 error = devfs_get_cdevpriv((void **)&d); 995 if (error != 0) 996 return (error); 997 998 /* 999 * Restrict application to use a buffer the same size as 1000 * as kernel buffers. 1001 */ 1002 if (uio->uio_resid != d->bd_bufsize) 1003 return (EINVAL); 1004 1005 non_block = ((ioflag & O_NONBLOCK) != 0); 1006 1007 BPFD_LOCK(d); 1008 BPF_PID_REFRESH_CUR(d); 1009 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 1010 BPFD_UNLOCK(d); 1011 return (EOPNOTSUPP); 1012 } 1013 if (d->bd_state == BPF_WAITING) 1014 callout_stop(&d->bd_callout); 1015 timed_out = (d->bd_state == BPF_TIMED_OUT); 1016 d->bd_state = BPF_IDLE; 1017 while (d->bd_hbuf_in_use) { 1018 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1019 PRINET|PCATCH, "bd_hbuf", 0); 1020 if (error != 0) { 1021 BPFD_UNLOCK(d); 1022 return (error); 1023 } 1024 } 1025 /* 1026 * If the hold buffer is empty, then do a timed sleep, which 1027 * ends when the timeout expires or when enough packets 1028 * have arrived to fill the store buffer. 1029 */ 1030 while (d->bd_hbuf == NULL) { 1031 if (d->bd_slen != 0) { 1032 /* 1033 * A packet(s) either arrived since the previous 1034 * read or arrived while we were asleep. 1035 */ 1036 if (d->bd_immediate || non_block || timed_out) { 1037 /* 1038 * Rotate the buffers and return what's here 1039 * if we are in immediate mode, non-blocking 1040 * flag is set, or this descriptor timed out. 1041 */ 1042 ROTATE_BUFFERS(d); 1043 break; 1044 } 1045 } 1046 1047 /* 1048 * No data is available, check to see if the bpf device 1049 * is still pointed at a real interface. If not, return 1050 * ENXIO so that the userland process knows to rebind 1051 * it before using it again. 1052 */ 1053 if (d->bd_bif == NULL) { 1054 BPFD_UNLOCK(d); 1055 return (ENXIO); 1056 } 1057 1058 if (non_block) { 1059 BPFD_UNLOCK(d); 1060 return (EWOULDBLOCK); 1061 } 1062 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 1063 "bpf", d->bd_rtout); 1064 if (error == EINTR || error == ERESTART) { 1065 BPFD_UNLOCK(d); 1066 return (error); 1067 } 1068 if (error == EWOULDBLOCK) { 1069 /* 1070 * On a timeout, return what's in the buffer, 1071 * which may be nothing. If there is something 1072 * in the store buffer, we can rotate the buffers. 1073 */ 1074 if (d->bd_hbuf) 1075 /* 1076 * We filled up the buffer in between 1077 * getting the timeout and arriving 1078 * here, so we don't need to rotate. 1079 */ 1080 break; 1081 1082 if (d->bd_slen == 0) { 1083 BPFD_UNLOCK(d); 1084 return (0); 1085 } 1086 ROTATE_BUFFERS(d); 1087 break; 1088 } 1089 } 1090 /* 1091 * At this point, we know we have something in the hold slot. 1092 */ 1093 d->bd_hbuf_in_use = 1; 1094 BPFD_UNLOCK(d); 1095 1096 /* 1097 * Move data from hold buffer into user space. 1098 * We know the entire buffer is transferred since 1099 * we checked above that the read buffer is bpf_bufsize bytes. 1100 * 1101 * We do not have to worry about simultaneous reads because 1102 * we waited for sole access to the hold buffer above. 1103 */ 1104 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1105 1106 BPFD_LOCK(d); 1107 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1108 d->bd_fbuf = d->bd_hbuf; 1109 d->bd_hbuf = NULL; 1110 d->bd_hlen = 0; 1111 bpf_buf_reclaimed(d); 1112 d->bd_hbuf_in_use = 0; 1113 wakeup(&d->bd_hbuf_in_use); 1114 BPFD_UNLOCK(d); 1115 1116 return (error); 1117 } 1118 1119 /* 1120 * If there are processes sleeping on this descriptor, wake them up. 1121 */ 1122 static __inline void 1123 bpf_wakeup(struct bpf_d *d) 1124 { 1125 1126 BPFD_LOCK_ASSERT(d); 1127 if (d->bd_state == BPF_WAITING) { 1128 callout_stop(&d->bd_callout); 1129 d->bd_state = BPF_IDLE; 1130 } 1131 wakeup(d); 1132 if (d->bd_async && d->bd_sig && d->bd_sigio) 1133 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1134 1135 selwakeuppri(&d->bd_sel, PRINET); 1136 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1137 } 1138 1139 static void 1140 bpf_timed_out(void *arg) 1141 { 1142 struct bpf_d *d = (struct bpf_d *)arg; 1143 1144 BPFD_LOCK_ASSERT(d); 1145 1146 if (callout_pending(&d->bd_callout) || 1147 !callout_active(&d->bd_callout)) 1148 return; 1149 if (d->bd_state == BPF_WAITING) { 1150 d->bd_state = BPF_TIMED_OUT; 1151 if (d->bd_slen != 0) 1152 bpf_wakeup(d); 1153 } 1154 } 1155 1156 static int 1157 bpf_ready(struct bpf_d *d) 1158 { 1159 1160 BPFD_LOCK_ASSERT(d); 1161 1162 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1163 return (1); 1164 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1165 d->bd_slen != 0) 1166 return (1); 1167 return (0); 1168 } 1169 1170 static int 1171 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1172 { 1173 struct route ro; 1174 struct sockaddr dst; 1175 struct epoch_tracker et; 1176 struct bpf_if *bp; 1177 struct bpf_d *d; 1178 struct ifnet *ifp; 1179 struct mbuf *m, *mc; 1180 int error, hlen; 1181 1182 error = devfs_get_cdevpriv((void **)&d); 1183 if (error != 0) 1184 return (error); 1185 1186 NET_EPOCH_ENTER(et); 1187 BPFD_LOCK(d); 1188 BPF_PID_REFRESH_CUR(d); 1189 counter_u64_add(d->bd_wcount, 1); 1190 if ((bp = d->bd_bif) == NULL) { 1191 error = ENXIO; 1192 goto out_locked; 1193 } 1194 1195 ifp = bp->bif_ifp; 1196 if ((ifp->if_flags & IFF_UP) == 0) { 1197 error = ENETDOWN; 1198 goto out_locked; 1199 } 1200 1201 if (uio->uio_resid == 0) 1202 goto out_locked; 1203 1204 bzero(&dst, sizeof(dst)); 1205 m = NULL; 1206 hlen = 0; 1207 1208 /* 1209 * Take extra reference, unlock d and exit from epoch section, 1210 * since bpf_movein() can sleep. 1211 */ 1212 bpfd_ref(d); 1213 NET_EPOCH_EXIT(et); 1214 BPFD_UNLOCK(d); 1215 1216 error = bpf_movein(uio, (int)bp->bif_dlt, ifp, 1217 &m, &dst, &hlen, d); 1218 1219 if (error != 0) { 1220 counter_u64_add(d->bd_wdcount, 1); 1221 bpfd_rele(d); 1222 return (error); 1223 } 1224 1225 BPFD_LOCK(d); 1226 /* 1227 * Check that descriptor is still attached to the interface. 1228 * This can happen on bpfdetach(). To avoid access to detached 1229 * ifnet, free mbuf and return ENXIO. 1230 */ 1231 if (d->bd_bif == NULL) { 1232 counter_u64_add(d->bd_wdcount, 1); 1233 BPFD_UNLOCK(d); 1234 bpfd_rele(d); 1235 m_freem(m); 1236 return (ENXIO); 1237 } 1238 counter_u64_add(d->bd_wfcount, 1); 1239 if (d->bd_hdrcmplt) 1240 dst.sa_family = pseudo_AF_HDRCMPLT; 1241 1242 if (d->bd_feedback) { 1243 mc = m_dup(m, M_NOWAIT); 1244 if (mc != NULL) 1245 mc->m_pkthdr.rcvif = ifp; 1246 /* Set M_PROMISC for outgoing packets to be discarded. */ 1247 if (d->bd_direction == BPF_D_INOUT) 1248 m->m_flags |= M_PROMISC; 1249 } else 1250 mc = NULL; 1251 1252 m->m_pkthdr.len -= hlen; 1253 m->m_len -= hlen; 1254 m->m_data += hlen; /* XXX */ 1255 1256 CURVNET_SET(ifp->if_vnet); 1257 #ifdef MAC 1258 mac_bpfdesc_create_mbuf(d, m); 1259 if (mc != NULL) 1260 mac_bpfdesc_create_mbuf(d, mc); 1261 #endif 1262 1263 bzero(&ro, sizeof(ro)); 1264 if (hlen != 0) { 1265 ro.ro_prepend = (u_char *)&dst.sa_data; 1266 ro.ro_plen = hlen; 1267 ro.ro_flags = RT_HAS_HEADER; 1268 } 1269 1270 /* Avoid possible recursion on BPFD_LOCK(). */ 1271 NET_EPOCH_ENTER(et); 1272 BPFD_UNLOCK(d); 1273 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1274 if (error) 1275 counter_u64_add(d->bd_wdcount, 1); 1276 1277 if (mc != NULL) { 1278 if (error == 0) 1279 (*ifp->if_input)(ifp, mc); 1280 else 1281 m_freem(mc); 1282 } 1283 NET_EPOCH_EXIT(et); 1284 CURVNET_RESTORE(); 1285 bpfd_rele(d); 1286 return (error); 1287 1288 out_locked: 1289 counter_u64_add(d->bd_wdcount, 1); 1290 NET_EPOCH_EXIT(et); 1291 BPFD_UNLOCK(d); 1292 return (error); 1293 } 1294 1295 /* 1296 * Reset a descriptor by flushing its packet buffer and clearing the receive 1297 * and drop counts. This is doable for kernel-only buffers, but with 1298 * zero-copy buffers, we can't write to (or rotate) buffers that are 1299 * currently owned by userspace. It would be nice if we could encapsulate 1300 * this logic in the buffer code rather than here. 1301 */ 1302 static void 1303 reset_d(struct bpf_d *d) 1304 { 1305 1306 BPFD_LOCK_ASSERT(d); 1307 1308 while (d->bd_hbuf_in_use) 1309 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1310 "bd_hbuf", 0); 1311 if ((d->bd_hbuf != NULL) && 1312 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1313 /* Free the hold buffer. */ 1314 d->bd_fbuf = d->bd_hbuf; 1315 d->bd_hbuf = NULL; 1316 d->bd_hlen = 0; 1317 bpf_buf_reclaimed(d); 1318 } 1319 if (bpf_canwritebuf(d)) 1320 d->bd_slen = 0; 1321 counter_u64_zero(d->bd_rcount); 1322 counter_u64_zero(d->bd_dcount); 1323 counter_u64_zero(d->bd_fcount); 1324 counter_u64_zero(d->bd_wcount); 1325 counter_u64_zero(d->bd_wfcount); 1326 counter_u64_zero(d->bd_wdcount); 1327 counter_u64_zero(d->bd_zcopy); 1328 } 1329 1330 /* 1331 * FIONREAD Check for read packet available. 1332 * BIOCGBLEN Get buffer len [for read()]. 1333 * BIOCSETF Set read filter. 1334 * BIOCSETFNR Set read filter without resetting descriptor. 1335 * BIOCSETWF Set write filter. 1336 * BIOCFLUSH Flush read packet buffer. 1337 * BIOCPROMISC Put interface into promiscuous mode. 1338 * BIOCGDLT Get link layer type. 1339 * BIOCGETIF Get interface name. 1340 * BIOCSETIF Set interface. 1341 * BIOCSRTIMEOUT Set read timeout. 1342 * BIOCGRTIMEOUT Get read timeout. 1343 * BIOCGSTATS Get packet stats. 1344 * BIOCIMMEDIATE Set immediate mode. 1345 * BIOCVERSION Get filter language version. 1346 * BIOCGHDRCMPLT Get "header already complete" flag 1347 * BIOCSHDRCMPLT Set "header already complete" flag 1348 * BIOCGDIRECTION Get packet direction flag 1349 * BIOCSDIRECTION Set packet direction flag 1350 * BIOCGTSTAMP Get time stamp format and resolution. 1351 * BIOCSTSTAMP Set time stamp format and resolution. 1352 * BIOCLOCK Set "locked" flag 1353 * BIOCFEEDBACK Set packet feedback mode. 1354 * BIOCSETZBUF Set current zero-copy buffer locations. 1355 * BIOCGETZMAX Get maximum zero-copy buffer size. 1356 * BIOCROTZBUF Force rotation of zero-copy buffer 1357 * BIOCSETBUFMODE Set buffer mode. 1358 * BIOCGETBUFMODE Get current buffer mode. 1359 */ 1360 /* ARGSUSED */ 1361 static int 1362 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1363 struct thread *td) 1364 { 1365 struct bpf_d *d; 1366 int error; 1367 1368 error = devfs_get_cdevpriv((void **)&d); 1369 if (error != 0) 1370 return (error); 1371 1372 /* 1373 * Refresh PID associated with this descriptor. 1374 */ 1375 BPFD_LOCK(d); 1376 BPF_PID_REFRESH(d, td); 1377 if (d->bd_state == BPF_WAITING) 1378 callout_stop(&d->bd_callout); 1379 d->bd_state = BPF_IDLE; 1380 BPFD_UNLOCK(d); 1381 1382 if (d->bd_locked == 1) { 1383 switch (cmd) { 1384 case BIOCGBLEN: 1385 case BIOCFLUSH: 1386 case BIOCGDLT: 1387 case BIOCGDLTLIST: 1388 #ifdef COMPAT_FREEBSD32 1389 case BIOCGDLTLIST32: 1390 #endif 1391 case BIOCGETIF: 1392 case BIOCGRTIMEOUT: 1393 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1394 case BIOCGRTIMEOUT32: 1395 #endif 1396 case BIOCGSTATS: 1397 case BIOCVERSION: 1398 case BIOCGRSIG: 1399 case BIOCGHDRCMPLT: 1400 case BIOCSTSTAMP: 1401 case BIOCFEEDBACK: 1402 case FIONREAD: 1403 case BIOCLOCK: 1404 case BIOCSRTIMEOUT: 1405 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1406 case BIOCSRTIMEOUT32: 1407 #endif 1408 case BIOCIMMEDIATE: 1409 case TIOCGPGRP: 1410 case BIOCROTZBUF: 1411 break; 1412 default: 1413 return (EPERM); 1414 } 1415 } 1416 #ifdef COMPAT_FREEBSD32 1417 /* 1418 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1419 * that it will get 32-bit packet headers. 1420 */ 1421 switch (cmd) { 1422 case BIOCSETF32: 1423 case BIOCSETFNR32: 1424 case BIOCSETWF32: 1425 case BIOCGDLTLIST32: 1426 case BIOCGRTIMEOUT32: 1427 case BIOCSRTIMEOUT32: 1428 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1429 BPFD_LOCK(d); 1430 d->bd_compat32 = 1; 1431 BPFD_UNLOCK(d); 1432 } 1433 } 1434 #endif 1435 1436 CURVNET_SET(TD_TO_VNET(td)); 1437 switch (cmd) { 1438 default: 1439 error = EINVAL; 1440 break; 1441 1442 /* 1443 * Check for read packet available. 1444 */ 1445 case FIONREAD: 1446 { 1447 int n; 1448 1449 BPFD_LOCK(d); 1450 n = d->bd_slen; 1451 while (d->bd_hbuf_in_use) 1452 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1453 PRINET, "bd_hbuf", 0); 1454 if (d->bd_hbuf) 1455 n += d->bd_hlen; 1456 BPFD_UNLOCK(d); 1457 1458 *(int *)addr = n; 1459 break; 1460 } 1461 1462 /* 1463 * Get buffer len [for read()]. 1464 */ 1465 case BIOCGBLEN: 1466 BPFD_LOCK(d); 1467 *(u_int *)addr = d->bd_bufsize; 1468 BPFD_UNLOCK(d); 1469 break; 1470 1471 /* 1472 * Set buffer length. 1473 */ 1474 case BIOCSBLEN: 1475 error = bpf_ioctl_sblen(d, (u_int *)addr); 1476 break; 1477 1478 /* 1479 * Set link layer read filter. 1480 */ 1481 case BIOCSETF: 1482 case BIOCSETFNR: 1483 case BIOCSETWF: 1484 #ifdef COMPAT_FREEBSD32 1485 case BIOCSETF32: 1486 case BIOCSETFNR32: 1487 case BIOCSETWF32: 1488 #endif 1489 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1490 break; 1491 1492 /* 1493 * Flush read packet buffer. 1494 */ 1495 case BIOCFLUSH: 1496 BPFD_LOCK(d); 1497 reset_d(d); 1498 BPFD_UNLOCK(d); 1499 break; 1500 1501 /* 1502 * Put interface into promiscuous mode. 1503 */ 1504 case BIOCPROMISC: 1505 if (d->bd_bif == NULL) { 1506 /* 1507 * No interface attached yet. 1508 */ 1509 error = EINVAL; 1510 break; 1511 } 1512 if (d->bd_promisc == 0) { 1513 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1514 if (error == 0) 1515 d->bd_promisc = 1; 1516 } 1517 break; 1518 1519 /* 1520 * Get current data link type. 1521 */ 1522 case BIOCGDLT: 1523 BPF_LOCK(); 1524 if (d->bd_bif == NULL) 1525 error = EINVAL; 1526 else 1527 *(u_int *)addr = d->bd_bif->bif_dlt; 1528 BPF_UNLOCK(); 1529 break; 1530 1531 /* 1532 * Get a list of supported data link types. 1533 */ 1534 #ifdef COMPAT_FREEBSD32 1535 case BIOCGDLTLIST32: 1536 { 1537 struct bpf_dltlist32 *list32; 1538 struct bpf_dltlist dltlist; 1539 1540 list32 = (struct bpf_dltlist32 *)addr; 1541 dltlist.bfl_len = list32->bfl_len; 1542 dltlist.bfl_list = PTRIN(list32->bfl_list); 1543 BPF_LOCK(); 1544 if (d->bd_bif == NULL) 1545 error = EINVAL; 1546 else { 1547 error = bpf_getdltlist(d, &dltlist); 1548 if (error == 0) 1549 list32->bfl_len = dltlist.bfl_len; 1550 } 1551 BPF_UNLOCK(); 1552 break; 1553 } 1554 #endif 1555 1556 case BIOCGDLTLIST: 1557 BPF_LOCK(); 1558 if (d->bd_bif == NULL) 1559 error = EINVAL; 1560 else 1561 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1562 BPF_UNLOCK(); 1563 break; 1564 1565 /* 1566 * Set data link type. 1567 */ 1568 case BIOCSDLT: 1569 BPF_LOCK(); 1570 if (d->bd_bif == NULL) 1571 error = EINVAL; 1572 else 1573 error = bpf_setdlt(d, *(u_int *)addr); 1574 BPF_UNLOCK(); 1575 break; 1576 1577 /* 1578 * Get interface name. 1579 */ 1580 case BIOCGETIF: 1581 BPF_LOCK(); 1582 if (d->bd_bif == NULL) 1583 error = EINVAL; 1584 else { 1585 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1586 struct ifreq *const ifr = (struct ifreq *)addr; 1587 1588 strlcpy(ifr->ifr_name, ifp->if_xname, 1589 sizeof(ifr->ifr_name)); 1590 } 1591 BPF_UNLOCK(); 1592 break; 1593 1594 /* 1595 * Set interface. 1596 */ 1597 case BIOCSETIF: 1598 { 1599 int alloc_buf, size; 1600 1601 /* 1602 * Behavior here depends on the buffering model. If 1603 * we're using kernel memory buffers, then we can 1604 * allocate them here. If we're using zero-copy, 1605 * then the user process must have registered buffers 1606 * by the time we get here. 1607 */ 1608 alloc_buf = 0; 1609 BPFD_LOCK(d); 1610 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1611 d->bd_sbuf == NULL) 1612 alloc_buf = 1; 1613 BPFD_UNLOCK(d); 1614 if (alloc_buf) { 1615 size = d->bd_bufsize; 1616 error = bpf_buffer_ioctl_sblen(d, &size); 1617 if (error != 0) 1618 break; 1619 } 1620 BPF_LOCK(); 1621 error = bpf_setif(d, (struct ifreq *)addr); 1622 BPF_UNLOCK(); 1623 break; 1624 } 1625 1626 /* 1627 * Set read timeout. 1628 */ 1629 case BIOCSRTIMEOUT: 1630 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1631 case BIOCSRTIMEOUT32: 1632 #endif 1633 { 1634 struct timeval *tv = (struct timeval *)addr; 1635 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1636 struct timeval32 *tv32; 1637 struct timeval tv64; 1638 1639 if (cmd == BIOCSRTIMEOUT32) { 1640 tv32 = (struct timeval32 *)addr; 1641 tv = &tv64; 1642 tv->tv_sec = tv32->tv_sec; 1643 tv->tv_usec = tv32->tv_usec; 1644 } else 1645 #endif 1646 tv = (struct timeval *)addr; 1647 1648 /* 1649 * Subtract 1 tick from tvtohz() since this isn't 1650 * a one-shot timer. 1651 */ 1652 if ((error = itimerfix(tv)) == 0) 1653 d->bd_rtout = tvtohz(tv) - 1; 1654 break; 1655 } 1656 1657 /* 1658 * Get read timeout. 1659 */ 1660 case BIOCGRTIMEOUT: 1661 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1662 case BIOCGRTIMEOUT32: 1663 #endif 1664 { 1665 struct timeval *tv; 1666 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1667 struct timeval32 *tv32; 1668 struct timeval tv64; 1669 1670 if (cmd == BIOCGRTIMEOUT32) 1671 tv = &tv64; 1672 else 1673 #endif 1674 tv = (struct timeval *)addr; 1675 1676 tv->tv_sec = d->bd_rtout / hz; 1677 tv->tv_usec = (d->bd_rtout % hz) * tick; 1678 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1679 if (cmd == BIOCGRTIMEOUT32) { 1680 tv32 = (struct timeval32 *)addr; 1681 tv32->tv_sec = tv->tv_sec; 1682 tv32->tv_usec = tv->tv_usec; 1683 } 1684 #endif 1685 1686 break; 1687 } 1688 1689 /* 1690 * Get packet stats. 1691 */ 1692 case BIOCGSTATS: 1693 { 1694 struct bpf_stat *bs = (struct bpf_stat *)addr; 1695 1696 /* XXXCSJP overflow */ 1697 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1698 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1699 break; 1700 } 1701 1702 /* 1703 * Set immediate mode. 1704 */ 1705 case BIOCIMMEDIATE: 1706 BPFD_LOCK(d); 1707 d->bd_immediate = *(u_int *)addr; 1708 BPFD_UNLOCK(d); 1709 break; 1710 1711 case BIOCVERSION: 1712 { 1713 struct bpf_version *bv = (struct bpf_version *)addr; 1714 1715 bv->bv_major = BPF_MAJOR_VERSION; 1716 bv->bv_minor = BPF_MINOR_VERSION; 1717 break; 1718 } 1719 1720 /* 1721 * Get "header already complete" flag 1722 */ 1723 case BIOCGHDRCMPLT: 1724 BPFD_LOCK(d); 1725 *(u_int *)addr = d->bd_hdrcmplt; 1726 BPFD_UNLOCK(d); 1727 break; 1728 1729 /* 1730 * Set "header already complete" flag 1731 */ 1732 case BIOCSHDRCMPLT: 1733 BPFD_LOCK(d); 1734 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1735 BPFD_UNLOCK(d); 1736 break; 1737 1738 /* 1739 * Get packet direction flag 1740 */ 1741 case BIOCGDIRECTION: 1742 BPFD_LOCK(d); 1743 *(u_int *)addr = d->bd_direction; 1744 BPFD_UNLOCK(d); 1745 break; 1746 1747 /* 1748 * Set packet direction flag 1749 */ 1750 case BIOCSDIRECTION: 1751 { 1752 u_int direction; 1753 1754 direction = *(u_int *)addr; 1755 switch (direction) { 1756 case BPF_D_IN: 1757 case BPF_D_INOUT: 1758 case BPF_D_OUT: 1759 BPFD_LOCK(d); 1760 d->bd_direction = direction; 1761 BPFD_UNLOCK(d); 1762 break; 1763 default: 1764 error = EINVAL; 1765 } 1766 } 1767 break; 1768 1769 /* 1770 * Get packet timestamp format and resolution. 1771 */ 1772 case BIOCGTSTAMP: 1773 BPFD_LOCK(d); 1774 *(u_int *)addr = d->bd_tstamp; 1775 BPFD_UNLOCK(d); 1776 break; 1777 1778 /* 1779 * Set packet timestamp format and resolution. 1780 */ 1781 case BIOCSTSTAMP: 1782 { 1783 u_int func; 1784 1785 func = *(u_int *)addr; 1786 if (BPF_T_VALID(func)) 1787 d->bd_tstamp = func; 1788 else 1789 error = EINVAL; 1790 } 1791 break; 1792 1793 case BIOCFEEDBACK: 1794 BPFD_LOCK(d); 1795 d->bd_feedback = *(u_int *)addr; 1796 BPFD_UNLOCK(d); 1797 break; 1798 1799 case BIOCLOCK: 1800 BPFD_LOCK(d); 1801 d->bd_locked = 1; 1802 BPFD_UNLOCK(d); 1803 break; 1804 1805 case FIONBIO: /* Non-blocking I/O */ 1806 break; 1807 1808 case FIOASYNC: /* Send signal on receive packets */ 1809 BPFD_LOCK(d); 1810 d->bd_async = *(int *)addr; 1811 BPFD_UNLOCK(d); 1812 break; 1813 1814 case FIOSETOWN: 1815 /* 1816 * XXX: Add some sort of locking here? 1817 * fsetown() can sleep. 1818 */ 1819 error = fsetown(*(int *)addr, &d->bd_sigio); 1820 break; 1821 1822 case FIOGETOWN: 1823 BPFD_LOCK(d); 1824 *(int *)addr = fgetown(&d->bd_sigio); 1825 BPFD_UNLOCK(d); 1826 break; 1827 1828 /* This is deprecated, FIOSETOWN should be used instead. */ 1829 case TIOCSPGRP: 1830 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1831 break; 1832 1833 /* This is deprecated, FIOGETOWN should be used instead. */ 1834 case TIOCGPGRP: 1835 *(int *)addr = -fgetown(&d->bd_sigio); 1836 break; 1837 1838 case BIOCSRSIG: /* Set receive signal */ 1839 { 1840 u_int sig; 1841 1842 sig = *(u_int *)addr; 1843 1844 if (sig >= NSIG) 1845 error = EINVAL; 1846 else { 1847 BPFD_LOCK(d); 1848 d->bd_sig = sig; 1849 BPFD_UNLOCK(d); 1850 } 1851 break; 1852 } 1853 case BIOCGRSIG: 1854 BPFD_LOCK(d); 1855 *(u_int *)addr = d->bd_sig; 1856 BPFD_UNLOCK(d); 1857 break; 1858 1859 case BIOCGETBUFMODE: 1860 BPFD_LOCK(d); 1861 *(u_int *)addr = d->bd_bufmode; 1862 BPFD_UNLOCK(d); 1863 break; 1864 1865 case BIOCSETBUFMODE: 1866 /* 1867 * Allow the buffering mode to be changed as long as we 1868 * haven't yet committed to a particular mode. Our 1869 * definition of commitment, for now, is whether or not a 1870 * buffer has been allocated or an interface attached, since 1871 * that's the point where things get tricky. 1872 */ 1873 switch (*(u_int *)addr) { 1874 case BPF_BUFMODE_BUFFER: 1875 break; 1876 1877 case BPF_BUFMODE_ZBUF: 1878 if (bpf_zerocopy_enable) 1879 break; 1880 /* FALLSTHROUGH */ 1881 1882 default: 1883 CURVNET_RESTORE(); 1884 return (EINVAL); 1885 } 1886 1887 BPFD_LOCK(d); 1888 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1889 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1890 BPFD_UNLOCK(d); 1891 CURVNET_RESTORE(); 1892 return (EBUSY); 1893 } 1894 d->bd_bufmode = *(u_int *)addr; 1895 BPFD_UNLOCK(d); 1896 break; 1897 1898 case BIOCGETZMAX: 1899 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1900 break; 1901 1902 case BIOCSETZBUF: 1903 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1904 break; 1905 1906 case BIOCROTZBUF: 1907 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1908 break; 1909 } 1910 CURVNET_RESTORE(); 1911 return (error); 1912 } 1913 1914 /* 1915 * Set d's packet filter program to fp. If this file already has a filter, 1916 * free it and replace it. Returns EINVAL for bogus requests. 1917 * 1918 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1919 * calls. 1920 */ 1921 static int 1922 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1923 { 1924 #ifdef COMPAT_FREEBSD32 1925 struct bpf_program fp_swab; 1926 struct bpf_program32 *fp32; 1927 #endif 1928 struct bpf_program_buffer *fcode; 1929 struct bpf_insn *filter; 1930 #ifdef BPF_JITTER 1931 bpf_jit_filter *jfunc; 1932 #endif 1933 size_t size; 1934 u_int flen; 1935 bool track_event; 1936 1937 #ifdef COMPAT_FREEBSD32 1938 switch (cmd) { 1939 case BIOCSETF32: 1940 case BIOCSETWF32: 1941 case BIOCSETFNR32: 1942 fp32 = (struct bpf_program32 *)fp; 1943 fp_swab.bf_len = fp32->bf_len; 1944 fp_swab.bf_insns = 1945 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1946 fp = &fp_swab; 1947 switch (cmd) { 1948 case BIOCSETF32: 1949 cmd = BIOCSETF; 1950 break; 1951 case BIOCSETWF32: 1952 cmd = BIOCSETWF; 1953 break; 1954 } 1955 break; 1956 } 1957 #endif 1958 1959 filter = NULL; 1960 #ifdef BPF_JITTER 1961 jfunc = NULL; 1962 #endif 1963 /* 1964 * Check new filter validness before acquiring any locks. 1965 * Allocate memory for new filter, if needed. 1966 */ 1967 flen = fp->bf_len; 1968 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1969 return (EINVAL); 1970 size = flen * sizeof(*fp->bf_insns); 1971 if (size > 0) { 1972 /* We're setting up new filter. Copy and check actual data. */ 1973 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1974 filter = (struct bpf_insn *)fcode->buffer; 1975 if (copyin(fp->bf_insns, filter, size) != 0 || 1976 !bpf_validate(filter, flen)) { 1977 free(fcode, M_BPF); 1978 return (EINVAL); 1979 } 1980 #ifdef BPF_JITTER 1981 if (cmd != BIOCSETWF) { 1982 /* 1983 * Filter is copied inside fcode and is 1984 * perfectly valid. 1985 */ 1986 jfunc = bpf_jitter(filter, flen); 1987 } 1988 #endif 1989 } 1990 1991 track_event = false; 1992 fcode = NULL; 1993 1994 BPF_LOCK(); 1995 BPFD_LOCK(d); 1996 /* Set up new filter. */ 1997 if (cmd == BIOCSETWF) { 1998 if (d->bd_wfilter != NULL) { 1999 fcode = __containerof((void *)d->bd_wfilter, 2000 struct bpf_program_buffer, buffer); 2001 #ifdef BPF_JITTER 2002 fcode->func = NULL; 2003 #endif 2004 } 2005 d->bd_wfilter = filter; 2006 } else { 2007 if (d->bd_rfilter != NULL) { 2008 fcode = __containerof((void *)d->bd_rfilter, 2009 struct bpf_program_buffer, buffer); 2010 #ifdef BPF_JITTER 2011 fcode->func = d->bd_bfilter; 2012 #endif 2013 } 2014 d->bd_rfilter = filter; 2015 #ifdef BPF_JITTER 2016 d->bd_bfilter = jfunc; 2017 #endif 2018 if (cmd == BIOCSETF) 2019 reset_d(d); 2020 2021 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 2022 /* 2023 * Filter can be set several times without 2024 * specifying interface. In this case just mark d 2025 * as reader. 2026 */ 2027 d->bd_writer = 0; 2028 if (d->bd_bif != NULL) { 2029 /* 2030 * Remove descriptor from writers-only list 2031 * and add it to active readers list. 2032 */ 2033 CK_LIST_REMOVE(d, bd_next); 2034 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 2035 d, bd_next); 2036 CTR2(KTR_NET, 2037 "%s: upgrade required by pid %d", 2038 __func__, d->bd_pid); 2039 track_event = true; 2040 } 2041 } 2042 } 2043 BPFD_UNLOCK(d); 2044 2045 if (fcode != NULL) 2046 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 2047 2048 if (track_event) 2049 EVENTHANDLER_INVOKE(bpf_track, 2050 d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); 2051 2052 BPF_UNLOCK(); 2053 return (0); 2054 } 2055 2056 /* 2057 * Detach a file from its current interface (if attached at all) and attach 2058 * to the interface indicated by the name stored in ifr. 2059 * Return an errno or 0. 2060 */ 2061 static int 2062 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 2063 { 2064 struct bpf_if *bp; 2065 struct ifnet *theywant; 2066 2067 BPF_LOCK_ASSERT(); 2068 2069 theywant = ifunit(ifr->ifr_name); 2070 if (theywant == NULL || theywant->if_bpf == NULL) 2071 return (ENXIO); 2072 2073 bp = theywant->if_bpf; 2074 /* 2075 * At this point, we expect the buffer is already allocated. If not, 2076 * return an error. 2077 */ 2078 switch (d->bd_bufmode) { 2079 case BPF_BUFMODE_BUFFER: 2080 case BPF_BUFMODE_ZBUF: 2081 if (d->bd_sbuf == NULL) 2082 return (EINVAL); 2083 break; 2084 2085 default: 2086 panic("bpf_setif: bufmode %d", d->bd_bufmode); 2087 } 2088 if (bp != d->bd_bif) 2089 bpf_attachd(d, bp); 2090 else { 2091 BPFD_LOCK(d); 2092 reset_d(d); 2093 BPFD_UNLOCK(d); 2094 } 2095 return (0); 2096 } 2097 2098 /* 2099 * Support for select() and poll() system calls 2100 * 2101 * Return true iff the specific operation will not block indefinitely. 2102 * Otherwise, return false but make a note that a selwakeup() must be done. 2103 */ 2104 static int 2105 bpfpoll(struct cdev *dev, int events, struct thread *td) 2106 { 2107 struct bpf_d *d; 2108 int revents; 2109 2110 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2111 return (events & 2112 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 2113 2114 /* 2115 * Refresh PID associated with this descriptor. 2116 */ 2117 revents = events & (POLLOUT | POLLWRNORM); 2118 BPFD_LOCK(d); 2119 BPF_PID_REFRESH(d, td); 2120 if (events & (POLLIN | POLLRDNORM)) { 2121 if (bpf_ready(d)) 2122 revents |= events & (POLLIN | POLLRDNORM); 2123 else { 2124 selrecord(td, &d->bd_sel); 2125 /* Start the read timeout if necessary. */ 2126 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2127 callout_reset(&d->bd_callout, d->bd_rtout, 2128 bpf_timed_out, d); 2129 d->bd_state = BPF_WAITING; 2130 } 2131 } 2132 } 2133 BPFD_UNLOCK(d); 2134 return (revents); 2135 } 2136 2137 /* 2138 * Support for kevent() system call. Register EVFILT_READ filters and 2139 * reject all others. 2140 */ 2141 int 2142 bpfkqfilter(struct cdev *dev, struct knote *kn) 2143 { 2144 struct bpf_d *d; 2145 2146 if (devfs_get_cdevpriv((void **)&d) != 0 || 2147 kn->kn_filter != EVFILT_READ) 2148 return (1); 2149 2150 /* 2151 * Refresh PID associated with this descriptor. 2152 */ 2153 BPFD_LOCK(d); 2154 BPF_PID_REFRESH_CUR(d); 2155 kn->kn_fop = &bpfread_filtops; 2156 kn->kn_hook = d; 2157 knlist_add(&d->bd_sel.si_note, kn, 1); 2158 BPFD_UNLOCK(d); 2159 2160 return (0); 2161 } 2162 2163 static void 2164 filt_bpfdetach(struct knote *kn) 2165 { 2166 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2167 2168 knlist_remove(&d->bd_sel.si_note, kn, 0); 2169 } 2170 2171 static int 2172 filt_bpfread(struct knote *kn, long hint) 2173 { 2174 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2175 int ready; 2176 2177 BPFD_LOCK_ASSERT(d); 2178 ready = bpf_ready(d); 2179 if (ready) { 2180 kn->kn_data = d->bd_slen; 2181 /* 2182 * Ignore the hold buffer if it is being copied to user space. 2183 */ 2184 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2185 kn->kn_data += d->bd_hlen; 2186 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2187 callout_reset(&d->bd_callout, d->bd_rtout, 2188 bpf_timed_out, d); 2189 d->bd_state = BPF_WAITING; 2190 } 2191 2192 return (ready); 2193 } 2194 2195 #define BPF_TSTAMP_NONE 0 2196 #define BPF_TSTAMP_FAST 1 2197 #define BPF_TSTAMP_NORMAL 2 2198 #define BPF_TSTAMP_EXTERN 3 2199 2200 static int 2201 bpf_ts_quality(int tstype) 2202 { 2203 2204 if (tstype == BPF_T_NONE) 2205 return (BPF_TSTAMP_NONE); 2206 if ((tstype & BPF_T_FAST) != 0) 2207 return (BPF_TSTAMP_FAST); 2208 2209 return (BPF_TSTAMP_NORMAL); 2210 } 2211 2212 static int 2213 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2214 { 2215 struct m_tag *tag; 2216 int quality; 2217 2218 quality = bpf_ts_quality(tstype); 2219 if (quality == BPF_TSTAMP_NONE) 2220 return (quality); 2221 2222 if (m != NULL) { 2223 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2224 if (tag != NULL) { 2225 *bt = *(struct bintime *)(tag + 1); 2226 return (BPF_TSTAMP_EXTERN); 2227 } 2228 } 2229 if (quality == BPF_TSTAMP_NORMAL) 2230 binuptime(bt); 2231 else 2232 getbinuptime(bt); 2233 2234 return (quality); 2235 } 2236 2237 /* 2238 * Incoming linkage from device drivers. Process the packet pkt, of length 2239 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2240 * by each process' filter, and if accepted, stashed into the corresponding 2241 * buffer. 2242 */ 2243 void 2244 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2245 { 2246 struct epoch_tracker et; 2247 struct bintime bt; 2248 struct bpf_d *d; 2249 #ifdef BPF_JITTER 2250 bpf_jit_filter *bf; 2251 #endif 2252 u_int slen; 2253 int gottime; 2254 2255 gottime = BPF_TSTAMP_NONE; 2256 NET_EPOCH_ENTER(et); 2257 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2258 counter_u64_add(d->bd_rcount, 1); 2259 /* 2260 * NB: We dont call BPF_CHECK_DIRECTION() here since there 2261 * is no way for the caller to indiciate to us whether this 2262 * packet is inbound or outbound. In the bpf_mtap() routines, 2263 * we use the interface pointers on the mbuf to figure it out. 2264 */ 2265 #ifdef BPF_JITTER 2266 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2267 if (bf != NULL) 2268 slen = (*(bf->func))(pkt, pktlen, pktlen); 2269 else 2270 #endif 2271 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2272 if (slen != 0) { 2273 /* 2274 * Filter matches. Let's to acquire write lock. 2275 */ 2276 BPFD_LOCK(d); 2277 counter_u64_add(d->bd_fcount, 1); 2278 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2279 gottime = bpf_gettime(&bt, d->bd_tstamp, 2280 NULL); 2281 #ifdef MAC 2282 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2283 #endif 2284 catchpacket(d, pkt, pktlen, slen, 2285 bpf_append_bytes, &bt); 2286 BPFD_UNLOCK(d); 2287 } 2288 } 2289 NET_EPOCH_EXIT(et); 2290 } 2291 2292 #define BPF_CHECK_DIRECTION(d, r, i) \ 2293 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2294 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2295 2296 /* 2297 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2298 * Locking model is explained in bpf_tap(). 2299 */ 2300 void 2301 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2302 { 2303 struct epoch_tracker et; 2304 struct bintime bt; 2305 struct bpf_d *d; 2306 #ifdef BPF_JITTER 2307 bpf_jit_filter *bf; 2308 #endif 2309 u_int pktlen, slen; 2310 int gottime; 2311 2312 /* Skip outgoing duplicate packets. */ 2313 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2314 m->m_flags &= ~M_PROMISC; 2315 return; 2316 } 2317 2318 pktlen = m_length(m, NULL); 2319 gottime = BPF_TSTAMP_NONE; 2320 2321 NET_EPOCH_ENTER(et); 2322 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2323 if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) 2324 continue; 2325 counter_u64_add(d->bd_rcount, 1); 2326 #ifdef BPF_JITTER 2327 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2328 /* XXX We cannot handle multiple mbufs. */ 2329 if (bf != NULL && m->m_next == NULL) 2330 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2331 pktlen); 2332 else 2333 #endif 2334 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2335 if (slen != 0) { 2336 BPFD_LOCK(d); 2337 2338 counter_u64_add(d->bd_fcount, 1); 2339 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2340 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2341 #ifdef MAC 2342 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2343 #endif 2344 catchpacket(d, (u_char *)m, pktlen, slen, 2345 bpf_append_mbuf, &bt); 2346 BPFD_UNLOCK(d); 2347 } 2348 } 2349 NET_EPOCH_EXIT(et); 2350 } 2351 2352 /* 2353 * Incoming linkage from device drivers, when packet is in 2354 * an mbuf chain and to be prepended by a contiguous header. 2355 */ 2356 void 2357 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2358 { 2359 struct epoch_tracker et; 2360 struct bintime bt; 2361 struct mbuf mb; 2362 struct bpf_d *d; 2363 u_int pktlen, slen; 2364 int gottime; 2365 2366 /* Skip outgoing duplicate packets. */ 2367 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2368 m->m_flags &= ~M_PROMISC; 2369 return; 2370 } 2371 2372 pktlen = m_length(m, NULL); 2373 /* 2374 * Craft on-stack mbuf suitable for passing to bpf_filter. 2375 * Note that we cut corners here; we only setup what's 2376 * absolutely needed--this mbuf should never go anywhere else. 2377 */ 2378 mb.m_flags = 0; 2379 mb.m_next = m; 2380 mb.m_data = data; 2381 mb.m_len = dlen; 2382 pktlen += dlen; 2383 2384 gottime = BPF_TSTAMP_NONE; 2385 2386 NET_EPOCH_ENTER(et); 2387 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2388 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2389 continue; 2390 counter_u64_add(d->bd_rcount, 1); 2391 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2392 if (slen != 0) { 2393 BPFD_LOCK(d); 2394 2395 counter_u64_add(d->bd_fcount, 1); 2396 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2397 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2398 #ifdef MAC 2399 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2400 #endif 2401 catchpacket(d, (u_char *)&mb, pktlen, slen, 2402 bpf_append_mbuf, &bt); 2403 BPFD_UNLOCK(d); 2404 } 2405 } 2406 NET_EPOCH_EXIT(et); 2407 } 2408 2409 #undef BPF_CHECK_DIRECTION 2410 #undef BPF_TSTAMP_NONE 2411 #undef BPF_TSTAMP_FAST 2412 #undef BPF_TSTAMP_NORMAL 2413 #undef BPF_TSTAMP_EXTERN 2414 2415 static int 2416 bpf_hdrlen(struct bpf_d *d) 2417 { 2418 int hdrlen; 2419 2420 hdrlen = d->bd_bif->bif_hdrlen; 2421 #ifndef BURN_BRIDGES 2422 if (d->bd_tstamp == BPF_T_NONE || 2423 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2424 #ifdef COMPAT_FREEBSD32 2425 if (d->bd_compat32) 2426 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2427 else 2428 #endif 2429 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2430 else 2431 #endif 2432 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2433 #ifdef COMPAT_FREEBSD32 2434 if (d->bd_compat32) 2435 hdrlen = BPF_WORDALIGN32(hdrlen); 2436 else 2437 #endif 2438 hdrlen = BPF_WORDALIGN(hdrlen); 2439 2440 return (hdrlen - d->bd_bif->bif_hdrlen); 2441 } 2442 2443 static void 2444 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2445 { 2446 struct bintime bt2, boottimebin; 2447 struct timeval tsm; 2448 struct timespec tsn; 2449 2450 if ((tstype & BPF_T_MONOTONIC) == 0) { 2451 bt2 = *bt; 2452 getboottimebin(&boottimebin); 2453 bintime_add(&bt2, &boottimebin); 2454 bt = &bt2; 2455 } 2456 switch (BPF_T_FORMAT(tstype)) { 2457 case BPF_T_MICROTIME: 2458 bintime2timeval(bt, &tsm); 2459 ts->bt_sec = tsm.tv_sec; 2460 ts->bt_frac = tsm.tv_usec; 2461 break; 2462 case BPF_T_NANOTIME: 2463 bintime2timespec(bt, &tsn); 2464 ts->bt_sec = tsn.tv_sec; 2465 ts->bt_frac = tsn.tv_nsec; 2466 break; 2467 case BPF_T_BINTIME: 2468 ts->bt_sec = bt->sec; 2469 ts->bt_frac = bt->frac; 2470 break; 2471 } 2472 } 2473 2474 /* 2475 * Move the packet data from interface memory (pkt) into the 2476 * store buffer. "cpfn" is the routine called to do the actual data 2477 * transfer. bcopy is passed in to copy contiguous chunks, while 2478 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2479 * pkt is really an mbuf. 2480 */ 2481 static void 2482 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2483 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2484 struct bintime *bt) 2485 { 2486 struct bpf_xhdr hdr; 2487 #ifndef BURN_BRIDGES 2488 struct bpf_hdr hdr_old; 2489 #ifdef COMPAT_FREEBSD32 2490 struct bpf_hdr32 hdr32_old; 2491 #endif 2492 #endif 2493 int caplen, curlen, hdrlen, totlen; 2494 int do_wakeup = 0; 2495 int do_timestamp; 2496 int tstype; 2497 2498 BPFD_LOCK_ASSERT(d); 2499 if (d->bd_bif == NULL) { 2500 /* Descriptor was detached in concurrent thread */ 2501 counter_u64_add(d->bd_dcount, 1); 2502 return; 2503 } 2504 2505 /* 2506 * Detect whether user space has released a buffer back to us, and if 2507 * so, move it from being a hold buffer to a free buffer. This may 2508 * not be the best place to do it (for example, we might only want to 2509 * run this check if we need the space), but for now it's a reliable 2510 * spot to do it. 2511 */ 2512 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2513 d->bd_fbuf = d->bd_hbuf; 2514 d->bd_hbuf = NULL; 2515 d->bd_hlen = 0; 2516 bpf_buf_reclaimed(d); 2517 } 2518 2519 /* 2520 * Figure out how many bytes to move. If the packet is 2521 * greater or equal to the snapshot length, transfer that 2522 * much. Otherwise, transfer the whole packet (unless 2523 * we hit the buffer size limit). 2524 */ 2525 hdrlen = bpf_hdrlen(d); 2526 totlen = hdrlen + min(snaplen, pktlen); 2527 if (totlen > d->bd_bufsize) 2528 totlen = d->bd_bufsize; 2529 2530 /* 2531 * Round up the end of the previous packet to the next longword. 2532 * 2533 * Drop the packet if there's no room and no hope of room 2534 * If the packet would overflow the storage buffer or the storage 2535 * buffer is considered immutable by the buffer model, try to rotate 2536 * the buffer and wakeup pending processes. 2537 */ 2538 #ifdef COMPAT_FREEBSD32 2539 if (d->bd_compat32) 2540 curlen = BPF_WORDALIGN32(d->bd_slen); 2541 else 2542 #endif 2543 curlen = BPF_WORDALIGN(d->bd_slen); 2544 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2545 if (d->bd_fbuf == NULL) { 2546 /* 2547 * There's no room in the store buffer, and no 2548 * prospect of room, so drop the packet. Notify the 2549 * buffer model. 2550 */ 2551 bpf_buffull(d); 2552 counter_u64_add(d->bd_dcount, 1); 2553 return; 2554 } 2555 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2556 ROTATE_BUFFERS(d); 2557 do_wakeup = 1; 2558 curlen = 0; 2559 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2560 /* 2561 * Immediate mode is set, or the read timeout has already 2562 * expired during a select call. A packet arrived, so the 2563 * reader should be woken up. 2564 */ 2565 do_wakeup = 1; 2566 caplen = totlen - hdrlen; 2567 tstype = d->bd_tstamp; 2568 do_timestamp = tstype != BPF_T_NONE; 2569 #ifndef BURN_BRIDGES 2570 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2571 struct bpf_ts ts; 2572 if (do_timestamp) 2573 bpf_bintime2ts(bt, &ts, tstype); 2574 #ifdef COMPAT_FREEBSD32 2575 if (d->bd_compat32) { 2576 bzero(&hdr32_old, sizeof(hdr32_old)); 2577 if (do_timestamp) { 2578 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2579 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2580 } 2581 hdr32_old.bh_datalen = pktlen; 2582 hdr32_old.bh_hdrlen = hdrlen; 2583 hdr32_old.bh_caplen = caplen; 2584 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2585 sizeof(hdr32_old)); 2586 goto copy; 2587 } 2588 #endif 2589 bzero(&hdr_old, sizeof(hdr_old)); 2590 if (do_timestamp) { 2591 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2592 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2593 } 2594 hdr_old.bh_datalen = pktlen; 2595 hdr_old.bh_hdrlen = hdrlen; 2596 hdr_old.bh_caplen = caplen; 2597 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2598 sizeof(hdr_old)); 2599 goto copy; 2600 } 2601 #endif 2602 2603 /* 2604 * Append the bpf header. Note we append the actual header size, but 2605 * move forward the length of the header plus padding. 2606 */ 2607 bzero(&hdr, sizeof(hdr)); 2608 if (do_timestamp) 2609 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2610 hdr.bh_datalen = pktlen; 2611 hdr.bh_hdrlen = hdrlen; 2612 hdr.bh_caplen = caplen; 2613 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2614 2615 /* 2616 * Copy the packet data into the store buffer and update its length. 2617 */ 2618 #ifndef BURN_BRIDGES 2619 copy: 2620 #endif 2621 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2622 d->bd_slen = curlen + totlen; 2623 2624 if (do_wakeup) 2625 bpf_wakeup(d); 2626 } 2627 2628 /* 2629 * Free buffers currently in use by a descriptor. 2630 * Called on close. 2631 */ 2632 static void 2633 bpfd_free(epoch_context_t ctx) 2634 { 2635 struct bpf_d *d; 2636 struct bpf_program_buffer *p; 2637 2638 /* 2639 * We don't need to lock out interrupts since this descriptor has 2640 * been detached from its interface and it yet hasn't been marked 2641 * free. 2642 */ 2643 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2644 bpf_free(d); 2645 if (d->bd_rfilter != NULL) { 2646 p = __containerof((void *)d->bd_rfilter, 2647 struct bpf_program_buffer, buffer); 2648 #ifdef BPF_JITTER 2649 p->func = d->bd_bfilter; 2650 #endif 2651 bpf_program_buffer_free(&p->epoch_ctx); 2652 } 2653 if (d->bd_wfilter != NULL) { 2654 p = __containerof((void *)d->bd_wfilter, 2655 struct bpf_program_buffer, buffer); 2656 #ifdef BPF_JITTER 2657 p->func = NULL; 2658 #endif 2659 bpf_program_buffer_free(&p->epoch_ctx); 2660 } 2661 2662 mtx_destroy(&d->bd_lock); 2663 counter_u64_free(d->bd_rcount); 2664 counter_u64_free(d->bd_dcount); 2665 counter_u64_free(d->bd_fcount); 2666 counter_u64_free(d->bd_wcount); 2667 counter_u64_free(d->bd_wfcount); 2668 counter_u64_free(d->bd_wdcount); 2669 counter_u64_free(d->bd_zcopy); 2670 free(d, M_BPF); 2671 } 2672 2673 /* 2674 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2675 * fixed size of the link header (variable length headers not yet supported). 2676 */ 2677 void 2678 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2679 { 2680 2681 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2682 } 2683 2684 /* 2685 * Attach an interface to bpf. ifp is a pointer to the structure 2686 * defining the interface to be attached, dlt is the link layer type, 2687 * and hdrlen is the fixed size of the link header (variable length 2688 * headers are not yet supporrted). 2689 */ 2690 void 2691 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, 2692 struct bpf_if **driverp) 2693 { 2694 struct bpf_if *bp; 2695 2696 KASSERT(*driverp == NULL, 2697 ("bpfattach2: driverp already initialized")); 2698 2699 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2700 2701 CK_LIST_INIT(&bp->bif_dlist); 2702 CK_LIST_INIT(&bp->bif_wlist); 2703 bp->bif_ifp = ifp; 2704 bp->bif_dlt = dlt; 2705 bp->bif_hdrlen = hdrlen; 2706 bp->bif_bpf = driverp; 2707 bp->bif_refcnt = 1; 2708 *driverp = bp; 2709 /* 2710 * Reference ifnet pointer, so it won't freed until 2711 * we release it. 2712 */ 2713 if_ref(ifp); 2714 BPF_LOCK(); 2715 CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2716 BPF_UNLOCK(); 2717 2718 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2719 if_printf(ifp, "bpf attached\n"); 2720 } 2721 2722 #ifdef VIMAGE 2723 /* 2724 * When moving interfaces between vnet instances we need a way to 2725 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2726 * after the vmove. We unfortunately have no device driver infrastructure 2727 * to query the interface for these values after creation/attach, thus 2728 * add this as a workaround. 2729 */ 2730 int 2731 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2732 { 2733 2734 if (bp == NULL) 2735 return (ENXIO); 2736 if (bif_dlt == NULL && bif_hdrlen == NULL) 2737 return (0); 2738 2739 if (bif_dlt != NULL) 2740 *bif_dlt = bp->bif_dlt; 2741 if (bif_hdrlen != NULL) 2742 *bif_hdrlen = bp->bif_hdrlen; 2743 2744 return (0); 2745 } 2746 #endif 2747 2748 /* 2749 * Detach bpf from an interface. This involves detaching each descriptor 2750 * associated with the interface. Notify each descriptor as it's detached 2751 * so that any sleepers wake up and get ENXIO. 2752 */ 2753 void 2754 bpfdetach(struct ifnet *ifp) 2755 { 2756 struct bpf_if *bp, *bp_temp; 2757 struct bpf_d *d; 2758 2759 BPF_LOCK(); 2760 /* Find all bpf_if struct's which reference ifp and detach them. */ 2761 CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2762 if (ifp != bp->bif_ifp) 2763 continue; 2764 2765 CK_LIST_REMOVE(bp, bif_next); 2766 *bp->bif_bpf = (struct bpf_if *)&dead_bpf_if; 2767 2768 CTR4(KTR_NET, 2769 "%s: sheduling free for encap %d (%p) for if %p", 2770 __func__, bp->bif_dlt, bp, ifp); 2771 2772 /* Detach common descriptors */ 2773 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2774 bpf_detachd_locked(d, true); 2775 } 2776 2777 /* Detach writer-only descriptors */ 2778 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2779 bpf_detachd_locked(d, true); 2780 } 2781 bpfif_rele(bp); 2782 } 2783 BPF_UNLOCK(); 2784 } 2785 2786 /* 2787 * Get a list of available data link type of the interface. 2788 */ 2789 static int 2790 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2791 { 2792 struct ifnet *ifp; 2793 struct bpf_if *bp; 2794 u_int *lst; 2795 int error, n, n1; 2796 2797 BPF_LOCK_ASSERT(); 2798 2799 ifp = d->bd_bif->bif_ifp; 2800 n1 = 0; 2801 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2802 if (bp->bif_ifp == ifp) 2803 n1++; 2804 } 2805 if (bfl->bfl_list == NULL) { 2806 bfl->bfl_len = n1; 2807 return (0); 2808 } 2809 if (n1 > bfl->bfl_len) 2810 return (ENOMEM); 2811 2812 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2813 n = 0; 2814 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2815 if (bp->bif_ifp != ifp) 2816 continue; 2817 lst[n++] = bp->bif_dlt; 2818 } 2819 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2820 free(lst, M_TEMP); 2821 bfl->bfl_len = n; 2822 return (error); 2823 } 2824 2825 /* 2826 * Set the data link type of a BPF instance. 2827 */ 2828 static int 2829 bpf_setdlt(struct bpf_d *d, u_int dlt) 2830 { 2831 int error, opromisc; 2832 struct ifnet *ifp; 2833 struct bpf_if *bp; 2834 2835 BPF_LOCK_ASSERT(); 2836 MPASS(d->bd_bif != NULL); 2837 2838 /* 2839 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2840 * changed while we hold global lock. 2841 */ 2842 if (d->bd_bif->bif_dlt == dlt) 2843 return (0); 2844 2845 ifp = d->bd_bif->bif_ifp; 2846 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2847 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2848 break; 2849 } 2850 if (bp == NULL) 2851 return (EINVAL); 2852 2853 opromisc = d->bd_promisc; 2854 bpf_attachd(d, bp); 2855 if (opromisc) { 2856 error = ifpromisc(bp->bif_ifp, 1); 2857 if (error) 2858 if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", 2859 __func__, error); 2860 else 2861 d->bd_promisc = 1; 2862 } 2863 return (0); 2864 } 2865 2866 static void 2867 bpf_drvinit(void *unused) 2868 { 2869 struct cdev *dev; 2870 2871 sx_init(&bpf_sx, "bpf global lock"); 2872 CK_LIST_INIT(&bpf_iflist); 2873 2874 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2875 /* For compatibility */ 2876 make_dev_alias(dev, "bpf0"); 2877 } 2878 2879 /* 2880 * Zero out the various packet counters associated with all of the bpf 2881 * descriptors. At some point, we will probably want to get a bit more 2882 * granular and allow the user to specify descriptors to be zeroed. 2883 */ 2884 static void 2885 bpf_zero_counters(void) 2886 { 2887 struct bpf_if *bp; 2888 struct bpf_d *bd; 2889 2890 BPF_LOCK(); 2891 /* 2892 * We are protected by global lock here, interfaces and 2893 * descriptors can not be deleted while we hold it. 2894 */ 2895 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2896 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2897 counter_u64_zero(bd->bd_rcount); 2898 counter_u64_zero(bd->bd_dcount); 2899 counter_u64_zero(bd->bd_fcount); 2900 counter_u64_zero(bd->bd_wcount); 2901 counter_u64_zero(bd->bd_wfcount); 2902 counter_u64_zero(bd->bd_zcopy); 2903 } 2904 } 2905 BPF_UNLOCK(); 2906 } 2907 2908 /* 2909 * Fill filter statistics 2910 */ 2911 static void 2912 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2913 { 2914 2915 BPF_LOCK_ASSERT(); 2916 bzero(d, sizeof(*d)); 2917 d->bd_structsize = sizeof(*d); 2918 d->bd_immediate = bd->bd_immediate; 2919 d->bd_promisc = bd->bd_promisc; 2920 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2921 d->bd_direction = bd->bd_direction; 2922 d->bd_feedback = bd->bd_feedback; 2923 d->bd_async = bd->bd_async; 2924 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2925 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2926 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2927 d->bd_sig = bd->bd_sig; 2928 d->bd_slen = bd->bd_slen; 2929 d->bd_hlen = bd->bd_hlen; 2930 d->bd_bufsize = bd->bd_bufsize; 2931 d->bd_pid = bd->bd_pid; 2932 strlcpy(d->bd_ifname, 2933 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2934 d->bd_locked = bd->bd_locked; 2935 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2936 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2937 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2938 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2939 d->bd_bufmode = bd->bd_bufmode; 2940 } 2941 2942 /* 2943 * Handle `netstat -B' stats request 2944 */ 2945 static int 2946 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2947 { 2948 static const struct xbpf_d zerostats; 2949 struct xbpf_d *xbdbuf, *xbd, tempstats; 2950 int index, error; 2951 struct bpf_if *bp; 2952 struct bpf_d *bd; 2953 2954 /* 2955 * XXX This is not technically correct. It is possible for non 2956 * privileged users to open bpf devices. It would make sense 2957 * if the users who opened the devices were able to retrieve 2958 * the statistics for them, too. 2959 */ 2960 error = priv_check(req->td, PRIV_NET_BPF); 2961 if (error) 2962 return (error); 2963 /* 2964 * Check to see if the user is requesting that the counters be 2965 * zeroed out. Explicitly check that the supplied data is zeroed, 2966 * as we aren't allowing the user to set the counters currently. 2967 */ 2968 if (req->newptr != NULL) { 2969 if (req->newlen != sizeof(tempstats)) 2970 return (EINVAL); 2971 memset(&tempstats, 0, sizeof(tempstats)); 2972 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2973 if (error) 2974 return (error); 2975 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2976 return (EINVAL); 2977 bpf_zero_counters(); 2978 return (0); 2979 } 2980 if (req->oldptr == NULL) 2981 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 2982 if (bpf_bpfd_cnt == 0) 2983 return (SYSCTL_OUT(req, 0, 0)); 2984 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 2985 BPF_LOCK(); 2986 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 2987 BPF_UNLOCK(); 2988 free(xbdbuf, M_BPF); 2989 return (ENOMEM); 2990 } 2991 index = 0; 2992 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2993 /* Send writers-only first */ 2994 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2995 xbd = &xbdbuf[index++]; 2996 bpfstats_fill_xbpf(xbd, bd); 2997 } 2998 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2999 xbd = &xbdbuf[index++]; 3000 bpfstats_fill_xbpf(xbd, bd); 3001 } 3002 } 3003 BPF_UNLOCK(); 3004 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 3005 free(xbdbuf, M_BPF); 3006 return (error); 3007 } 3008 3009 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 3010 3011 #else /* !DEV_BPF && !NETGRAPH_BPF */ 3012 3013 /* 3014 * NOP stubs to allow bpf-using drivers to load and function. 3015 * 3016 * A 'better' implementation would allow the core bpf functionality 3017 * to be loaded at runtime. 3018 */ 3019 3020 void 3021 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3022 { 3023 } 3024 3025 void 3026 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3027 { 3028 } 3029 3030 void 3031 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3032 { 3033 } 3034 3035 void 3036 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3037 { 3038 3039 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3040 } 3041 3042 void 3043 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3044 { 3045 3046 *driverp = (struct bpf_if *)&dead_bpf_if; 3047 } 3048 3049 void 3050 bpfdetach(struct ifnet *ifp) 3051 { 3052 } 3053 3054 u_int 3055 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3056 { 3057 return -1; /* "no filter" behaviour */ 3058 } 3059 3060 int 3061 bpf_validate(const struct bpf_insn *f, int len) 3062 { 3063 return 0; /* false */ 3064 } 3065 3066 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3067 3068 #ifdef DDB 3069 static void 3070 bpf_show_bpf_if(struct bpf_if *bpf_if) 3071 { 3072 3073 if (bpf_if == NULL) 3074 return; 3075 db_printf("%p:\n", bpf_if); 3076 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3077 /* bif_ext.bif_next */ 3078 /* bif_ext.bif_dlist */ 3079 BPF_DB_PRINTF("%#x", bif_dlt); 3080 BPF_DB_PRINTF("%u", bif_hdrlen); 3081 /* bif_wlist */ 3082 BPF_DB_PRINTF("%p", bif_ifp); 3083 BPF_DB_PRINTF("%p", bif_bpf); 3084 BPF_DB_PRINTF("%u", bif_refcnt); 3085 } 3086 3087 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3088 { 3089 3090 if (!have_addr) { 3091 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3092 return; 3093 } 3094 3095 bpf_show_bpf_if((struct bpf_if *)addr); 3096 } 3097 #endif 3098