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 38 #include <sys/cdefs.h> 39 #include "opt_bpf.h" 40 #include "opt_ddb.h" 41 #include "opt_netgraph.h" 42 43 #include <sys/param.h> 44 #include <sys/conf.h> 45 #include <sys/eventhandler.h> 46 #include <sys/fcntl.h> 47 #include <sys/jail.h> 48 #include <sys/ktr.h> 49 #include <sys/lock.h> 50 #include <sys/malloc.h> 51 #include <sys/mbuf.h> 52 #include <sys/mutex.h> 53 #include <sys/time.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/signalvar.h> 57 #include <sys/filio.h> 58 #include <sys/sockio.h> 59 #include <sys/ttycom.h> 60 #include <sys/uio.h> 61 #include <sys/sysent.h> 62 #include <sys/systm.h> 63 64 #include <sys/event.h> 65 #include <sys/file.h> 66 #include <sys/poll.h> 67 #include <sys/proc.h> 68 69 #include <sys/socket.h> 70 71 #ifdef DDB 72 #include <ddb/ddb.h> 73 #endif 74 75 #include <net/if.h> 76 #include <net/if_var.h> 77 #include <net/if_private.h> 78 #include <net/if_vlan_var.h> 79 #include <net/if_dl.h> 80 #include <net/bpf.h> 81 #include <net/bpf_buffer.h> 82 #ifdef BPF_JITTER 83 #include <net/bpf_jitter.h> 84 #endif 85 #include <net/bpf_zerocopy.h> 86 #include <net/bpfdesc.h> 87 #include <net/route.h> 88 #include <net/vnet.h> 89 90 #include <netinet/in.h> 91 #include <netinet/if_ether.h> 92 #include <sys/kernel.h> 93 #include <sys/sysctl.h> 94 95 #include <net80211/ieee80211_freebsd.h> 96 97 #include <security/mac/mac_framework.h> 98 99 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 100 101 static const struct bpf_if_ext dead_bpf_if = { 102 .bif_dlist = CK_LIST_HEAD_INITIALIZER() 103 }; 104 105 struct bpf_if { 106 #define bif_next bif_ext.bif_next 107 #define bif_dlist bif_ext.bif_dlist 108 struct bpf_if_ext bif_ext; /* public members */ 109 u_int bif_dlt; /* link layer type */ 110 u_int bif_hdrlen; /* length of link header */ 111 struct bpfd_list bif_wlist; /* writer-only list */ 112 struct ifnet *bif_ifp; /* corresponding interface */ 113 struct bpf_if **bif_bpf; /* Pointer to pointer to us */ 114 volatile u_int bif_refcnt; 115 struct epoch_context epoch_ctx; 116 }; 117 118 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); 119 120 struct bpf_program_buffer { 121 struct epoch_context epoch_ctx; 122 #ifdef BPF_JITTER 123 bpf_jit_filter *func; 124 #endif 125 void *buffer[0]; 126 }; 127 128 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 129 130 #define PRINET 26 /* interruptible */ 131 #define BPF_PRIO_MAX 7 132 133 #define SIZEOF_BPF_HDR(type) \ 134 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 135 136 #ifdef COMPAT_FREEBSD32 137 #include <sys/mount.h> 138 #include <compat/freebsd32/freebsd32.h> 139 #define BPF_ALIGNMENT32 sizeof(int32_t) 140 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) 141 142 #ifndef BURN_BRIDGES 143 /* 144 * 32-bit version of structure prepended to each packet. We use this header 145 * instead of the standard one for 32-bit streams. We mark the a stream as 146 * 32-bit the first time we see a 32-bit compat ioctl request. 147 */ 148 struct bpf_hdr32 { 149 struct timeval32 bh_tstamp; /* time stamp */ 150 uint32_t bh_caplen; /* length of captured portion */ 151 uint32_t bh_datalen; /* original length of packet */ 152 uint16_t bh_hdrlen; /* length of bpf header (this struct 153 plus alignment padding) */ 154 }; 155 #endif 156 157 struct bpf_program32 { 158 u_int bf_len; 159 uint32_t bf_insns; 160 }; 161 162 struct bpf_dltlist32 { 163 u_int bfl_len; 164 u_int bfl_list; 165 }; 166 167 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 168 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 169 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 170 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 171 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 172 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 173 #endif 174 175 #define BPF_LOCK() sx_xlock(&bpf_sx) 176 #define BPF_UNLOCK() sx_xunlock(&bpf_sx) 177 #define BPF_LOCK_ASSERT() sx_assert(&bpf_sx, SA_XLOCKED) 178 /* 179 * bpf_iflist is a list of BPF interface structures, each corresponding to a 180 * specific DLT. The same network interface might have several BPF interface 181 * structures registered by different layers in the stack (i.e., 802.11 182 * frames, ethernet frames, etc). 183 */ 184 CK_LIST_HEAD(bpf_iflist, bpf_if); 185 static struct bpf_iflist bpf_iflist = CK_LIST_HEAD_INITIALIZER(); 186 static struct sx bpf_sx; /* bpf global lock */ 187 static int bpf_bpfd_cnt; 188 189 static void bpfif_ref(struct bpf_if *); 190 static void bpfif_rele(struct bpf_if *); 191 192 static void bpfd_ref(struct bpf_d *); 193 static void bpfd_rele(struct bpf_d *); 194 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 195 static void bpf_detachd(struct bpf_d *); 196 static void bpf_detachd_locked(struct bpf_d *, bool); 197 static void bpfd_free(epoch_context_t); 198 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 199 struct sockaddr *, int *, struct bpf_d *); 200 static int bpf_setif(struct bpf_d *, struct ifreq *); 201 static void bpf_timed_out(void *); 202 static __inline void 203 bpf_wakeup(struct bpf_d *); 204 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 205 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 206 struct bintime *); 207 static void reset_d(struct bpf_d *); 208 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 209 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 210 static int bpf_setdlt(struct bpf_d *, u_int); 211 static void filt_bpfdetach(struct knote *); 212 static int filt_bpfread(struct knote *, long); 213 static int filt_bpfwrite(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 const struct filterops bpfread_filtops = { 253 .f_isfd = 1, 254 .f_detach = filt_bpfdetach, 255 .f_event = filt_bpfread, 256 }; 257 258 static const struct filterops bpfwrite_filtops = { 259 .f_isfd = 1, 260 .f_detach = filt_bpfdetach, 261 .f_event = filt_bpfwrite, 262 }; 263 264 /* 265 * LOCKING MODEL USED BY BPF 266 * 267 * Locks: 268 * 1) global lock (BPF_LOCK). Sx, used to protect some global counters, 269 * every bpf_iflist changes, serializes ioctl access to bpf descriptors. 270 * 2) Descriptor lock. Mutex, used to protect BPF buffers and various 271 * structure fields used by bpf_*tap* code. 272 * 273 * Lock order: global lock, then descriptor lock. 274 * 275 * There are several possible consumers: 276 * 277 * 1. The kernel registers interface pointer with bpfattach(). 278 * Each call allocates new bpf_if structure, references ifnet pointer 279 * and links bpf_if into bpf_iflist chain. This is protected with global 280 * lock. 281 * 282 * 2. An userland application uses ioctl() call to bpf_d descriptor. 283 * All such call are serialized with global lock. BPF filters can be 284 * changed, but pointer to old filter will be freed using NET_EPOCH_CALL(). 285 * Thus it should be safe for bpf_tap/bpf_mtap* code to do access to 286 * filter pointers, even if change will happen during bpf_tap execution. 287 * Destroying of bpf_d descriptor also is doing using NET_EPOCH_CALL(). 288 * 289 * 3. An userland application can write packets into bpf_d descriptor. 290 * There we need to be sure, that ifnet won't disappear during bpfwrite(). 291 * 292 * 4. The kernel invokes bpf_tap/bpf_mtap* functions. The access to 293 * bif_dlist is protected with net_epoch_preempt section. So, it should 294 * be safe to make access to bpf_d descriptor inside the section. 295 * 296 * 5. The kernel invokes bpfdetach() on interface destroying. All lists 297 * are modified with global lock held and actual free() is done using 298 * NET_EPOCH_CALL(). 299 */ 300 301 static void 302 bpfif_free(epoch_context_t ctx) 303 { 304 struct bpf_if *bp; 305 306 bp = __containerof(ctx, struct bpf_if, epoch_ctx); 307 if_rele(bp->bif_ifp); 308 free(bp, M_BPF); 309 } 310 311 static void 312 bpfif_ref(struct bpf_if *bp) 313 { 314 315 refcount_acquire(&bp->bif_refcnt); 316 } 317 318 static void 319 bpfif_rele(struct bpf_if *bp) 320 { 321 322 if (!refcount_release(&bp->bif_refcnt)) 323 return; 324 NET_EPOCH_CALL(bpfif_free, &bp->epoch_ctx); 325 } 326 327 static void 328 bpfd_ref(struct bpf_d *d) 329 { 330 331 refcount_acquire(&d->bd_refcnt); 332 } 333 334 static void 335 bpfd_rele(struct bpf_d *d) 336 { 337 338 if (!refcount_release(&d->bd_refcnt)) 339 return; 340 NET_EPOCH_CALL(bpfd_free, &d->epoch_ctx); 341 } 342 343 static struct bpf_program_buffer* 344 bpf_program_buffer_alloc(size_t size, int flags) 345 { 346 347 return (malloc(sizeof(struct bpf_program_buffer) + size, 348 M_BPF, flags)); 349 } 350 351 static void 352 bpf_program_buffer_free(epoch_context_t ctx) 353 { 354 struct bpf_program_buffer *ptr; 355 356 ptr = __containerof(ctx, struct bpf_program_buffer, epoch_ctx); 357 #ifdef BPF_JITTER 358 if (ptr->func != NULL) 359 bpf_destroy_jit_filter(ptr->func); 360 #endif 361 free(ptr, M_BPF); 362 } 363 364 /* 365 * Wrapper functions for various buffering methods. If the set of buffer 366 * modes expands, we will probably want to introduce a switch data structure 367 * similar to protosw, et. 368 */ 369 static void 370 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 371 u_int len) 372 { 373 374 BPFD_LOCK_ASSERT(d); 375 376 switch (d->bd_bufmode) { 377 case BPF_BUFMODE_BUFFER: 378 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 379 380 case BPF_BUFMODE_ZBUF: 381 counter_u64_add(d->bd_zcopy, 1); 382 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 383 384 default: 385 panic("bpf_buf_append_bytes"); 386 } 387 } 388 389 static void 390 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 391 u_int len) 392 { 393 394 BPFD_LOCK_ASSERT(d); 395 396 switch (d->bd_bufmode) { 397 case BPF_BUFMODE_BUFFER: 398 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 399 400 case BPF_BUFMODE_ZBUF: 401 counter_u64_add(d->bd_zcopy, 1); 402 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 403 404 default: 405 panic("bpf_buf_append_mbuf"); 406 } 407 } 408 409 /* 410 * This function gets called when the free buffer is re-assigned. 411 */ 412 static void 413 bpf_buf_reclaimed(struct bpf_d *d) 414 { 415 416 BPFD_LOCK_ASSERT(d); 417 418 switch (d->bd_bufmode) { 419 case BPF_BUFMODE_BUFFER: 420 return; 421 422 case BPF_BUFMODE_ZBUF: 423 bpf_zerocopy_buf_reclaimed(d); 424 return; 425 426 default: 427 panic("bpf_buf_reclaimed"); 428 } 429 } 430 431 /* 432 * If the buffer mechanism has a way to decide that a held buffer can be made 433 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 434 * returned if the buffer can be discarded, (0) is returned if it cannot. 435 */ 436 static int 437 bpf_canfreebuf(struct bpf_d *d) 438 { 439 440 BPFD_LOCK_ASSERT(d); 441 442 switch (d->bd_bufmode) { 443 case BPF_BUFMODE_ZBUF: 444 return (bpf_zerocopy_canfreebuf(d)); 445 } 446 return (0); 447 } 448 449 /* 450 * Allow the buffer model to indicate that the current store buffer is 451 * immutable, regardless of the appearance of space. Return (1) if the 452 * buffer is writable, and (0) if not. 453 */ 454 static int 455 bpf_canwritebuf(struct bpf_d *d) 456 { 457 BPFD_LOCK_ASSERT(d); 458 459 switch (d->bd_bufmode) { 460 case BPF_BUFMODE_ZBUF: 461 return (bpf_zerocopy_canwritebuf(d)); 462 } 463 return (1); 464 } 465 466 /* 467 * Notify buffer model that an attempt to write to the store buffer has 468 * resulted in a dropped packet, in which case the buffer may be considered 469 * full. 470 */ 471 static void 472 bpf_buffull(struct bpf_d *d) 473 { 474 475 BPFD_LOCK_ASSERT(d); 476 477 switch (d->bd_bufmode) { 478 case BPF_BUFMODE_ZBUF: 479 bpf_zerocopy_buffull(d); 480 break; 481 } 482 } 483 484 /* 485 * Notify the buffer model that a buffer has moved into the hold position. 486 */ 487 void 488 bpf_bufheld(struct bpf_d *d) 489 { 490 491 BPFD_LOCK_ASSERT(d); 492 493 switch (d->bd_bufmode) { 494 case BPF_BUFMODE_ZBUF: 495 bpf_zerocopy_bufheld(d); 496 break; 497 } 498 } 499 500 static void 501 bpf_free(struct bpf_d *d) 502 { 503 504 switch (d->bd_bufmode) { 505 case BPF_BUFMODE_BUFFER: 506 return (bpf_buffer_free(d)); 507 508 case BPF_BUFMODE_ZBUF: 509 return (bpf_zerocopy_free(d)); 510 511 default: 512 panic("bpf_buf_free"); 513 } 514 } 515 516 static int 517 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 518 { 519 520 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 521 return (EOPNOTSUPP); 522 return (bpf_buffer_uiomove(d, buf, len, uio)); 523 } 524 525 static int 526 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 527 { 528 529 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 530 return (EOPNOTSUPP); 531 return (bpf_buffer_ioctl_sblen(d, i)); 532 } 533 534 static int 535 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 536 { 537 538 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 539 return (EOPNOTSUPP); 540 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 541 } 542 543 static int 544 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 545 { 546 547 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 548 return (EOPNOTSUPP); 549 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 550 } 551 552 static int 553 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 554 { 555 556 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 557 return (EOPNOTSUPP); 558 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 559 } 560 561 /* 562 * General BPF functions. 563 */ 564 static int 565 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 566 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) 567 { 568 const struct ieee80211_bpf_params *p; 569 struct ether_header *eh; 570 struct mbuf *m; 571 int error; 572 int len; 573 int hlen; 574 int slen; 575 576 /* 577 * Build a sockaddr based on the data link layer type. 578 * We do this at this level because the ethernet header 579 * is copied directly into the data field of the sockaddr. 580 * In the case of SLIP, there is no header and the packet 581 * is forwarded as is. 582 * Also, we are careful to leave room at the front of the mbuf 583 * for the link level header. 584 */ 585 switch (linktype) { 586 case DLT_SLIP: 587 sockp->sa_family = AF_INET; 588 hlen = 0; 589 break; 590 591 case DLT_EN10MB: 592 sockp->sa_family = AF_UNSPEC; 593 /* XXX Would MAXLINKHDR be better? */ 594 hlen = ETHER_HDR_LEN; 595 break; 596 597 case DLT_FDDI: 598 sockp->sa_family = AF_IMPLINK; 599 hlen = 0; 600 break; 601 602 case DLT_RAW: 603 sockp->sa_family = AF_UNSPEC; 604 hlen = 0; 605 break; 606 607 case DLT_NULL: 608 /* 609 * null interface types require a 4 byte pseudo header which 610 * corresponds to the address family of the packet. 611 */ 612 sockp->sa_family = AF_UNSPEC; 613 hlen = 4; 614 break; 615 616 case DLT_ATM_RFC1483: 617 /* 618 * en atm driver requires 4-byte atm pseudo header. 619 * though it isn't standard, vpi:vci needs to be 620 * specified anyway. 621 */ 622 sockp->sa_family = AF_UNSPEC; 623 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 624 break; 625 626 case DLT_PPP: 627 sockp->sa_family = AF_UNSPEC; 628 hlen = 4; /* This should match PPP_HDRLEN */ 629 break; 630 631 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 632 sockp->sa_family = AF_IEEE80211; 633 hlen = 0; 634 break; 635 636 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 637 sockp->sa_family = AF_IEEE80211; 638 sockp->sa_len = 12; /* XXX != 0 */ 639 hlen = sizeof(struct ieee80211_bpf_params); 640 break; 641 642 default: 643 return (EIO); 644 } 645 646 len = uio->uio_resid; 647 if (len < hlen || len - hlen > ifp->if_mtu) 648 return (EMSGSIZE); 649 650 /* Allocate a mbuf, up to MJUM16BYTES bytes, for our write. */ 651 m = m_get3(len, M_WAITOK, MT_DATA, M_PKTHDR); 652 if (m == NULL) 653 return (EIO); 654 m->m_pkthdr.len = m->m_len = len; 655 *mp = m; 656 657 error = uiomove(mtod(m, u_char *), len, uio); 658 if (error) 659 goto bad; 660 661 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 662 if (slen == 0) { 663 error = EPERM; 664 goto bad; 665 } 666 667 /* Check for multicast destination */ 668 switch (linktype) { 669 case DLT_EN10MB: 670 eh = mtod(m, struct ether_header *); 671 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 672 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 673 ETHER_ADDR_LEN) == 0) 674 m->m_flags |= M_BCAST; 675 else 676 m->m_flags |= M_MCAST; 677 } 678 if (d->bd_hdrcmplt == 0) { 679 memcpy(eh->ether_shost, IF_LLADDR(ifp), 680 sizeof(eh->ether_shost)); 681 } 682 break; 683 } 684 685 /* 686 * Make room for link header, and copy it to sockaddr 687 */ 688 if (hlen != 0) { 689 if (sockp->sa_family == AF_IEEE80211) { 690 /* 691 * Collect true length from the parameter header 692 * NB: sockp is known to be zero'd so if we do a 693 * short copy unspecified parameters will be 694 * zero. 695 * NB: packet may not be aligned after stripping 696 * bpf params 697 * XXX check ibp_vers 698 */ 699 p = mtod(m, const struct ieee80211_bpf_params *); 700 hlen = p->ibp_len; 701 if (hlen > sizeof(sockp->sa_data)) { 702 error = EINVAL; 703 goto bad; 704 } 705 } 706 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 707 } 708 *hdrlen = hlen; 709 710 return (0); 711 bad: 712 m_freem(m); 713 return (error); 714 } 715 716 /* 717 * Attach descriptor to the bpf interface, i.e. make d listen on bp, 718 * then reset its buffers and counters with reset_d(). 719 */ 720 static void 721 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 722 { 723 int op_w; 724 725 BPF_LOCK_ASSERT(); 726 727 /* 728 * Save sysctl value to protect from sysctl change 729 * between reads 730 */ 731 op_w = V_bpf_optimize_writers || d->bd_writer; 732 733 if (d->bd_bif != NULL) 734 bpf_detachd_locked(d, false); 735 /* 736 * Point d at bp, and add d to the interface's list. 737 * Since there are many applications using BPF for 738 * sending raw packets only (dhcpd, cdpd are good examples) 739 * we can delay adding d to the list of active listeners until 740 * some filter is configured. 741 */ 742 743 BPFD_LOCK(d); 744 /* 745 * Hold reference to bpif while descriptor uses this interface. 746 */ 747 bpfif_ref(bp); 748 d->bd_bif = bp; 749 if (op_w != 0) { 750 /* Add to writers-only list */ 751 CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 752 /* 753 * We decrement bd_writer on every filter set operation. 754 * First BIOCSETF is done by pcap_open_live() to set up 755 * snap length. After that appliation usually sets its own 756 * filter. 757 */ 758 d->bd_writer = 2; 759 } else 760 CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 761 762 reset_d(d); 763 764 /* Trigger EVFILT_WRITE events. */ 765 bpf_wakeup(d); 766 767 BPFD_UNLOCK(d); 768 bpf_bpfd_cnt++; 769 770 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 771 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 772 773 if (op_w == 0) 774 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 775 } 776 777 /* 778 * Check if we need to upgrade our descriptor @d from write-only mode. 779 */ 780 static int 781 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 782 int flen) 783 { 784 int is_snap, need_upgrade; 785 786 /* 787 * Check if we've already upgraded or new filter is empty. 788 */ 789 if (d->bd_writer == 0 || fcode == NULL) 790 return (0); 791 792 need_upgrade = 0; 793 794 /* 795 * Check if cmd looks like snaplen setting from 796 * pcap_bpf.c:pcap_open_live(). 797 * Note we're not checking .k value here: 798 * while pcap_open_live() definitely sets to non-zero value, 799 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 800 * do not consider upgrading immediately 801 */ 802 if (cmd == BIOCSETF && flen == 1 && 803 fcode[0].code == (BPF_RET | BPF_K)) 804 is_snap = 1; 805 else 806 is_snap = 0; 807 808 if (is_snap == 0) { 809 /* 810 * We're setting first filter and it doesn't look like 811 * setting snaplen. We're probably using bpf directly. 812 * Upgrade immediately. 813 */ 814 need_upgrade = 1; 815 } else { 816 /* 817 * Do not require upgrade by first BIOCSETF 818 * (used to set snaplen) by pcap_open_live(). 819 */ 820 821 if (--d->bd_writer == 0) { 822 /* 823 * First snaplen filter has already 824 * been set. This is probably catch-all 825 * filter 826 */ 827 need_upgrade = 1; 828 } 829 } 830 831 CTR5(KTR_NET, 832 "%s: filter function set by pid %d, " 833 "bd_writer counter %d, snap %d upgrade %d", 834 __func__, d->bd_pid, d->bd_writer, 835 is_snap, need_upgrade); 836 837 return (need_upgrade); 838 } 839 840 /* 841 * Detach a file from its interface. 842 */ 843 static void 844 bpf_detachd(struct bpf_d *d) 845 { 846 BPF_LOCK(); 847 bpf_detachd_locked(d, false); 848 BPF_UNLOCK(); 849 } 850 851 static void 852 bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) 853 { 854 struct bpf_if *bp; 855 struct ifnet *ifp; 856 int error; 857 858 BPF_LOCK_ASSERT(); 859 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 860 861 /* Check if descriptor is attached */ 862 if ((bp = d->bd_bif) == NULL) 863 return; 864 865 BPFD_LOCK(d); 866 /* Remove d from the interface's descriptor list. */ 867 CK_LIST_REMOVE(d, bd_next); 868 /* Save bd_writer value */ 869 error = d->bd_writer; 870 ifp = bp->bif_ifp; 871 d->bd_bif = NULL; 872 if (detached_ifp) { 873 /* 874 * Notify descriptor as it's detached, so that any 875 * sleepers wake up and get ENXIO. 876 */ 877 bpf_wakeup(d); 878 } 879 BPFD_UNLOCK(d); 880 bpf_bpfd_cnt--; 881 882 /* Call event handler iff d is attached */ 883 if (error == 0) 884 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 885 886 /* 887 * Check if this descriptor had requested promiscuous mode. 888 * If so and ifnet is not detached, turn it off. 889 */ 890 if (d->bd_promisc && !detached_ifp) { 891 d->bd_promisc = 0; 892 CURVNET_SET(ifp->if_vnet); 893 error = ifpromisc(ifp, 0); 894 CURVNET_RESTORE(); 895 if (error != 0 && error != ENXIO) { 896 /* 897 * ENXIO can happen if a pccard is unplugged 898 * Something is really wrong if we were able to put 899 * the driver into promiscuous mode, but can't 900 * take it out. 901 */ 902 if_printf(bp->bif_ifp, 903 "bpf_detach: ifpromisc failed (%d)\n", error); 904 } 905 } 906 bpfif_rele(bp); 907 } 908 909 /* 910 * Close the descriptor by detaching it from its interface, 911 * deallocating its buffers, and marking it free. 912 */ 913 static void 914 bpf_dtor(void *data) 915 { 916 struct bpf_d *d = data; 917 918 BPFD_LOCK(d); 919 if (d->bd_state == BPF_WAITING) 920 callout_stop(&d->bd_callout); 921 d->bd_state = BPF_IDLE; 922 BPFD_UNLOCK(d); 923 funsetown(&d->bd_sigio); 924 bpf_detachd(d); 925 #ifdef MAC 926 mac_bpfdesc_destroy(d); 927 #endif /* MAC */ 928 seldrain(&d->bd_sel); 929 knlist_destroy(&d->bd_sel.si_note); 930 callout_drain(&d->bd_callout); 931 bpfd_rele(d); 932 } 933 934 /* 935 * Open ethernet device. Returns ENXIO for illegal minor device number, 936 * EBUSY if file is open by another process. 937 */ 938 /* ARGSUSED */ 939 static int 940 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 941 { 942 struct bpf_d *d; 943 int error; 944 945 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 946 error = devfs_set_cdevpriv(d, bpf_dtor); 947 if (error != 0) { 948 free(d, M_BPF); 949 return (error); 950 } 951 952 /* Setup counters */ 953 d->bd_rcount = counter_u64_alloc(M_WAITOK); 954 d->bd_dcount = counter_u64_alloc(M_WAITOK); 955 d->bd_fcount = counter_u64_alloc(M_WAITOK); 956 d->bd_wcount = counter_u64_alloc(M_WAITOK); 957 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 958 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 959 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 960 961 /* 962 * For historical reasons, perform a one-time initialization call to 963 * the buffer routines, even though we're not yet committed to a 964 * particular buffer method. 965 */ 966 bpf_buffer_init(d); 967 if ((flags & FREAD) == 0) 968 d->bd_writer = 2; 969 d->bd_hbuf_in_use = 0; 970 d->bd_bufmode = BPF_BUFMODE_BUFFER; 971 d->bd_sig = SIGIO; 972 d->bd_direction = BPF_D_INOUT; 973 refcount_init(&d->bd_refcnt, 1); 974 BPF_PID_REFRESH(d, td); 975 #ifdef MAC 976 mac_bpfdesc_init(d); 977 mac_bpfdesc_create(td->td_ucred, d); 978 #endif 979 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 980 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 981 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 982 983 /* Disable VLAN pcp tagging. */ 984 d->bd_pcp = 0; 985 986 return (0); 987 } 988 989 /* 990 * bpfread - read next chunk of packets from buffers 991 */ 992 static int 993 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 994 { 995 struct bpf_d *d; 996 int error; 997 int non_block; 998 int timed_out; 999 1000 error = devfs_get_cdevpriv((void **)&d); 1001 if (error != 0) 1002 return (error); 1003 1004 /* 1005 * Restrict application to use a buffer the same size as 1006 * as kernel buffers. 1007 */ 1008 if (uio->uio_resid != d->bd_bufsize) 1009 return (EINVAL); 1010 1011 non_block = ((ioflag & O_NONBLOCK) != 0); 1012 1013 BPFD_LOCK(d); 1014 BPF_PID_REFRESH_CUR(d); 1015 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 1016 BPFD_UNLOCK(d); 1017 return (EOPNOTSUPP); 1018 } 1019 if (d->bd_state == BPF_WAITING) 1020 callout_stop(&d->bd_callout); 1021 timed_out = (d->bd_state == BPF_TIMED_OUT); 1022 d->bd_state = BPF_IDLE; 1023 while (d->bd_hbuf_in_use) { 1024 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1025 PRINET | PCATCH, "bd_hbuf", 0); 1026 if (error != 0) { 1027 BPFD_UNLOCK(d); 1028 return (error); 1029 } 1030 } 1031 /* 1032 * If the hold buffer is empty, then do a timed sleep, which 1033 * ends when the timeout expires or when enough packets 1034 * have arrived to fill the store buffer. 1035 */ 1036 while (d->bd_hbuf == NULL) { 1037 if (d->bd_slen != 0) { 1038 /* 1039 * A packet(s) either arrived since the previous 1040 * read or arrived while we were asleep. 1041 */ 1042 if (d->bd_immediate || non_block || timed_out) { 1043 /* 1044 * Rotate the buffers and return what's here 1045 * if we are in immediate mode, non-blocking 1046 * flag is set, or this descriptor timed out. 1047 */ 1048 ROTATE_BUFFERS(d); 1049 break; 1050 } 1051 } 1052 1053 /* 1054 * No data is available, check to see if the bpf device 1055 * is still pointed at a real interface. If not, return 1056 * ENXIO so that the userland process knows to rebind 1057 * it before using it again. 1058 */ 1059 if (d->bd_bif == NULL) { 1060 BPFD_UNLOCK(d); 1061 return (ENXIO); 1062 } 1063 1064 if (non_block) { 1065 BPFD_UNLOCK(d); 1066 return (EWOULDBLOCK); 1067 } 1068 error = msleep(d, &d->bd_lock, PRINET | PCATCH, 1069 "bpf", d->bd_rtout); 1070 if (error == EINTR || error == ERESTART) { 1071 BPFD_UNLOCK(d); 1072 return (error); 1073 } 1074 if (error == EWOULDBLOCK) { 1075 /* 1076 * On a timeout, return what's in the buffer, 1077 * which may be nothing. If there is something 1078 * in the store buffer, we can rotate the buffers. 1079 */ 1080 if (d->bd_hbuf) 1081 /* 1082 * We filled up the buffer in between 1083 * getting the timeout and arriving 1084 * here, so we don't need to rotate. 1085 */ 1086 break; 1087 1088 if (d->bd_slen == 0) { 1089 BPFD_UNLOCK(d); 1090 return (0); 1091 } 1092 ROTATE_BUFFERS(d); 1093 break; 1094 } 1095 } 1096 /* 1097 * At this point, we know we have something in the hold slot. 1098 */ 1099 d->bd_hbuf_in_use = 1; 1100 BPFD_UNLOCK(d); 1101 1102 /* 1103 * Move data from hold buffer into user space. 1104 * We know the entire buffer is transferred since 1105 * we checked above that the read buffer is bpf_bufsize bytes. 1106 * 1107 * We do not have to worry about simultaneous reads because 1108 * we waited for sole access to the hold buffer above. 1109 */ 1110 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1111 1112 BPFD_LOCK(d); 1113 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1114 d->bd_fbuf = d->bd_hbuf; 1115 d->bd_hbuf = NULL; 1116 d->bd_hlen = 0; 1117 bpf_buf_reclaimed(d); 1118 d->bd_hbuf_in_use = 0; 1119 wakeup(&d->bd_hbuf_in_use); 1120 BPFD_UNLOCK(d); 1121 1122 return (error); 1123 } 1124 1125 /* 1126 * If there are processes sleeping on this descriptor, wake them up. 1127 */ 1128 static __inline void 1129 bpf_wakeup(struct bpf_d *d) 1130 { 1131 1132 BPFD_LOCK_ASSERT(d); 1133 if (d->bd_state == BPF_WAITING) { 1134 callout_stop(&d->bd_callout); 1135 d->bd_state = BPF_IDLE; 1136 } 1137 wakeup(d); 1138 if (d->bd_async && d->bd_sig && d->bd_sigio) 1139 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1140 1141 selwakeuppri(&d->bd_sel, PRINET); 1142 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1143 } 1144 1145 static void 1146 bpf_timed_out(void *arg) 1147 { 1148 struct bpf_d *d = (struct bpf_d *)arg; 1149 1150 BPFD_LOCK_ASSERT(d); 1151 1152 if (callout_pending(&d->bd_callout) || 1153 !callout_active(&d->bd_callout)) 1154 return; 1155 if (d->bd_state == BPF_WAITING) { 1156 d->bd_state = BPF_TIMED_OUT; 1157 if (d->bd_slen != 0) 1158 bpf_wakeup(d); 1159 } 1160 } 1161 1162 static int 1163 bpf_ready(struct bpf_d *d) 1164 { 1165 1166 BPFD_LOCK_ASSERT(d); 1167 1168 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1169 return (1); 1170 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1171 d->bd_slen != 0) 1172 return (1); 1173 return (0); 1174 } 1175 1176 static int 1177 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1178 { 1179 struct route ro; 1180 struct sockaddr dst; 1181 struct epoch_tracker et; 1182 struct bpf_if *bp; 1183 struct bpf_d *d; 1184 struct ifnet *ifp; 1185 struct mbuf *m, *mc; 1186 int error, hlen; 1187 1188 error = devfs_get_cdevpriv((void **)&d); 1189 if (error != 0) 1190 return (error); 1191 1192 NET_EPOCH_ENTER(et); 1193 BPFD_LOCK(d); 1194 BPF_PID_REFRESH_CUR(d); 1195 counter_u64_add(d->bd_wcount, 1); 1196 if ((bp = d->bd_bif) == NULL) { 1197 error = ENXIO; 1198 goto out_locked; 1199 } 1200 1201 ifp = bp->bif_ifp; 1202 if ((ifp->if_flags & IFF_UP) == 0) { 1203 error = ENETDOWN; 1204 goto out_locked; 1205 } 1206 1207 if (uio->uio_resid == 0) 1208 goto out_locked; 1209 1210 bzero(&dst, sizeof(dst)); 1211 m = NULL; 1212 hlen = 0; 1213 1214 /* 1215 * Take extra reference, unlock d and exit from epoch section, 1216 * since bpf_movein() can sleep. 1217 */ 1218 bpfd_ref(d); 1219 NET_EPOCH_EXIT(et); 1220 BPFD_UNLOCK(d); 1221 1222 error = bpf_movein(uio, (int)bp->bif_dlt, ifp, 1223 &m, &dst, &hlen, d); 1224 1225 if (error != 0) { 1226 counter_u64_add(d->bd_wdcount, 1); 1227 bpfd_rele(d); 1228 return (error); 1229 } 1230 1231 BPFD_LOCK(d); 1232 /* 1233 * Check that descriptor is still attached to the interface. 1234 * This can happen on bpfdetach(). To avoid access to detached 1235 * ifnet, free mbuf and return ENXIO. 1236 */ 1237 if (d->bd_bif == NULL) { 1238 counter_u64_add(d->bd_wdcount, 1); 1239 BPFD_UNLOCK(d); 1240 bpfd_rele(d); 1241 m_freem(m); 1242 return (ENXIO); 1243 } 1244 counter_u64_add(d->bd_wfcount, 1); 1245 if (d->bd_hdrcmplt) 1246 dst.sa_family = pseudo_AF_HDRCMPLT; 1247 1248 if (d->bd_feedback) { 1249 mc = m_dup(m, M_NOWAIT); 1250 if (mc != NULL) 1251 mc->m_pkthdr.rcvif = ifp; 1252 /* Set M_PROMISC for outgoing packets to be discarded. */ 1253 if (d->bd_direction == BPF_D_INOUT) 1254 m->m_flags |= M_PROMISC; 1255 } else 1256 mc = NULL; 1257 1258 m->m_pkthdr.len -= hlen; 1259 m->m_len -= hlen; 1260 m->m_data += hlen; /* XXX */ 1261 1262 CURVNET_SET(ifp->if_vnet); 1263 #ifdef MAC 1264 mac_bpfdesc_create_mbuf(d, m); 1265 if (mc != NULL) 1266 mac_bpfdesc_create_mbuf(d, mc); 1267 #endif 1268 1269 bzero(&ro, sizeof(ro)); 1270 if (hlen != 0) { 1271 ro.ro_prepend = (u_char *)&dst.sa_data; 1272 ro.ro_plen = hlen; 1273 ro.ro_flags = RT_HAS_HEADER; 1274 } 1275 1276 if (d->bd_pcp != 0) 1277 vlan_set_pcp(m, d->bd_pcp); 1278 1279 /* Avoid possible recursion on BPFD_LOCK(). */ 1280 NET_EPOCH_ENTER(et); 1281 BPFD_UNLOCK(d); 1282 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1283 if (error) 1284 counter_u64_add(d->bd_wdcount, 1); 1285 1286 if (mc != NULL) { 1287 if (error == 0) 1288 (*ifp->if_input)(ifp, mc); 1289 else 1290 m_freem(mc); 1291 } 1292 NET_EPOCH_EXIT(et); 1293 CURVNET_RESTORE(); 1294 bpfd_rele(d); 1295 return (error); 1296 1297 out_locked: 1298 counter_u64_add(d->bd_wdcount, 1); 1299 NET_EPOCH_EXIT(et); 1300 BPFD_UNLOCK(d); 1301 return (error); 1302 } 1303 1304 /* 1305 * Reset a descriptor by flushing its packet buffer and clearing the receive 1306 * and drop counts. This is doable for kernel-only buffers, but with 1307 * zero-copy buffers, we can't write to (or rotate) buffers that are 1308 * currently owned by userspace. It would be nice if we could encapsulate 1309 * this logic in the buffer code rather than here. 1310 */ 1311 static void 1312 reset_d(struct bpf_d *d) 1313 { 1314 1315 BPFD_LOCK_ASSERT(d); 1316 1317 while (d->bd_hbuf_in_use) 1318 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1319 "bd_hbuf", 0); 1320 if ((d->bd_hbuf != NULL) && 1321 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1322 /* Free the hold buffer. */ 1323 d->bd_fbuf = d->bd_hbuf; 1324 d->bd_hbuf = NULL; 1325 d->bd_hlen = 0; 1326 bpf_buf_reclaimed(d); 1327 } 1328 if (bpf_canwritebuf(d)) 1329 d->bd_slen = 0; 1330 counter_u64_zero(d->bd_rcount); 1331 counter_u64_zero(d->bd_dcount); 1332 counter_u64_zero(d->bd_fcount); 1333 counter_u64_zero(d->bd_wcount); 1334 counter_u64_zero(d->bd_wfcount); 1335 counter_u64_zero(d->bd_wdcount); 1336 counter_u64_zero(d->bd_zcopy); 1337 } 1338 1339 /* 1340 * FIONREAD Check for read packet available. 1341 * BIOCGBLEN Get buffer len [for read()]. 1342 * BIOCSETF Set read filter. 1343 * BIOCSETFNR Set read filter without resetting descriptor. 1344 * BIOCSETWF Set write filter. 1345 * BIOCFLUSH Flush read packet buffer. 1346 * BIOCPROMISC Put interface into promiscuous mode. 1347 * BIOCGDLT Get link layer type. 1348 * BIOCGETIF Get interface name. 1349 * BIOCSETIF Set interface. 1350 * BIOCSRTIMEOUT Set read timeout. 1351 * BIOCGRTIMEOUT Get read timeout. 1352 * BIOCGSTATS Get packet stats. 1353 * BIOCIMMEDIATE Set immediate mode. 1354 * BIOCVERSION Get filter language version. 1355 * BIOCGHDRCMPLT Get "header already complete" flag 1356 * BIOCSHDRCMPLT Set "header already complete" flag 1357 * BIOCGDIRECTION Get packet direction flag 1358 * BIOCSDIRECTION Set packet direction flag 1359 * BIOCGTSTAMP Get time stamp format and resolution. 1360 * BIOCSTSTAMP Set time stamp format and resolution. 1361 * BIOCLOCK Set "locked" flag 1362 * BIOCFEEDBACK Set packet feedback mode. 1363 * BIOCSETZBUF Set current zero-copy buffer locations. 1364 * BIOCGETZMAX Get maximum zero-copy buffer size. 1365 * BIOCROTZBUF Force rotation of zero-copy buffer 1366 * BIOCSETBUFMODE Set buffer mode. 1367 * BIOCGETBUFMODE Get current buffer mode. 1368 * BIOCSETVLANPCP Set VLAN PCP tag. 1369 */ 1370 /* ARGSUSED */ 1371 static int 1372 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1373 struct thread *td) 1374 { 1375 struct bpf_d *d; 1376 int error; 1377 1378 error = devfs_get_cdevpriv((void **)&d); 1379 if (error != 0) 1380 return (error); 1381 1382 /* 1383 * Refresh PID associated with this descriptor. 1384 */ 1385 BPFD_LOCK(d); 1386 BPF_PID_REFRESH(d, td); 1387 if (d->bd_state == BPF_WAITING) 1388 callout_stop(&d->bd_callout); 1389 d->bd_state = BPF_IDLE; 1390 BPFD_UNLOCK(d); 1391 1392 if (d->bd_locked == 1) { 1393 switch (cmd) { 1394 case BIOCGBLEN: 1395 case BIOCFLUSH: 1396 case BIOCGDLT: 1397 case BIOCGDLTLIST: 1398 #ifdef COMPAT_FREEBSD32 1399 case BIOCGDLTLIST32: 1400 #endif 1401 case BIOCGETIF: 1402 case BIOCGRTIMEOUT: 1403 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1404 case BIOCGRTIMEOUT32: 1405 #endif 1406 case BIOCGSTATS: 1407 case BIOCVERSION: 1408 case BIOCGRSIG: 1409 case BIOCGHDRCMPLT: 1410 case BIOCSTSTAMP: 1411 case BIOCFEEDBACK: 1412 case FIONREAD: 1413 case BIOCLOCK: 1414 case BIOCSRTIMEOUT: 1415 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1416 case BIOCSRTIMEOUT32: 1417 #endif 1418 case BIOCIMMEDIATE: 1419 case TIOCGPGRP: 1420 case BIOCROTZBUF: 1421 break; 1422 default: 1423 return (EPERM); 1424 } 1425 } 1426 #ifdef COMPAT_FREEBSD32 1427 /* 1428 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1429 * that it will get 32-bit packet headers. 1430 */ 1431 switch (cmd) { 1432 case BIOCSETF32: 1433 case BIOCSETFNR32: 1434 case BIOCSETWF32: 1435 case BIOCGDLTLIST32: 1436 case BIOCGRTIMEOUT32: 1437 case BIOCSRTIMEOUT32: 1438 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1439 BPFD_LOCK(d); 1440 d->bd_compat32 = 1; 1441 BPFD_UNLOCK(d); 1442 } 1443 } 1444 #endif 1445 1446 CURVNET_SET(TD_TO_VNET(td)); 1447 switch (cmd) { 1448 default: 1449 error = EINVAL; 1450 break; 1451 1452 /* 1453 * Check for read packet available. 1454 */ 1455 case FIONREAD: 1456 { 1457 int n; 1458 1459 BPFD_LOCK(d); 1460 n = d->bd_slen; 1461 while (d->bd_hbuf_in_use) 1462 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1463 PRINET, "bd_hbuf", 0); 1464 if (d->bd_hbuf) 1465 n += d->bd_hlen; 1466 BPFD_UNLOCK(d); 1467 1468 *(int *)addr = n; 1469 break; 1470 } 1471 1472 /* 1473 * Get buffer len [for read()]. 1474 */ 1475 case BIOCGBLEN: 1476 BPFD_LOCK(d); 1477 *(u_int *)addr = d->bd_bufsize; 1478 BPFD_UNLOCK(d); 1479 break; 1480 1481 /* 1482 * Set buffer length. 1483 */ 1484 case BIOCSBLEN: 1485 error = bpf_ioctl_sblen(d, (u_int *)addr); 1486 break; 1487 1488 /* 1489 * Set link layer read filter. 1490 */ 1491 case BIOCSETF: 1492 case BIOCSETFNR: 1493 case BIOCSETWF: 1494 #ifdef COMPAT_FREEBSD32 1495 case BIOCSETF32: 1496 case BIOCSETFNR32: 1497 case BIOCSETWF32: 1498 #endif 1499 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1500 break; 1501 1502 /* 1503 * Flush read packet buffer. 1504 */ 1505 case BIOCFLUSH: 1506 BPFD_LOCK(d); 1507 reset_d(d); 1508 BPFD_UNLOCK(d); 1509 break; 1510 1511 /* 1512 * Put interface into promiscuous mode. 1513 */ 1514 case BIOCPROMISC: 1515 BPF_LOCK(); 1516 if (d->bd_bif == NULL) { 1517 /* 1518 * No interface attached yet. 1519 */ 1520 error = EINVAL; 1521 } else if (d->bd_promisc == 0) { 1522 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1523 if (error == 0) 1524 d->bd_promisc = 1; 1525 } 1526 BPF_UNLOCK(); 1527 break; 1528 1529 /* 1530 * Get current data link type. 1531 */ 1532 case BIOCGDLT: 1533 BPF_LOCK(); 1534 if (d->bd_bif == NULL) 1535 error = EINVAL; 1536 else 1537 *(u_int *)addr = d->bd_bif->bif_dlt; 1538 BPF_UNLOCK(); 1539 break; 1540 1541 /* 1542 * Get a list of supported data link types. 1543 */ 1544 #ifdef COMPAT_FREEBSD32 1545 case BIOCGDLTLIST32: 1546 { 1547 struct bpf_dltlist32 *list32; 1548 struct bpf_dltlist dltlist; 1549 1550 list32 = (struct bpf_dltlist32 *)addr; 1551 dltlist.bfl_len = list32->bfl_len; 1552 dltlist.bfl_list = PTRIN(list32->bfl_list); 1553 BPF_LOCK(); 1554 if (d->bd_bif == NULL) 1555 error = EINVAL; 1556 else { 1557 error = bpf_getdltlist(d, &dltlist); 1558 if (error == 0) 1559 list32->bfl_len = dltlist.bfl_len; 1560 } 1561 BPF_UNLOCK(); 1562 break; 1563 } 1564 #endif 1565 1566 case BIOCGDLTLIST: 1567 BPF_LOCK(); 1568 if (d->bd_bif == NULL) 1569 error = EINVAL; 1570 else 1571 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1572 BPF_UNLOCK(); 1573 break; 1574 1575 /* 1576 * Set data link type. 1577 */ 1578 case BIOCSDLT: 1579 BPF_LOCK(); 1580 if (d->bd_bif == NULL) 1581 error = EINVAL; 1582 else 1583 error = bpf_setdlt(d, *(u_int *)addr); 1584 BPF_UNLOCK(); 1585 break; 1586 1587 /* 1588 * Get interface name. 1589 */ 1590 case BIOCGETIF: 1591 BPF_LOCK(); 1592 if (d->bd_bif == NULL) 1593 error = EINVAL; 1594 else { 1595 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1596 struct ifreq *const ifr = (struct ifreq *)addr; 1597 1598 strlcpy(ifr->ifr_name, ifp->if_xname, 1599 sizeof(ifr->ifr_name)); 1600 } 1601 BPF_UNLOCK(); 1602 break; 1603 1604 /* 1605 * Set interface. 1606 */ 1607 case BIOCSETIF: 1608 { 1609 int alloc_buf, size; 1610 1611 /* 1612 * Behavior here depends on the buffering model. If 1613 * we're using kernel memory buffers, then we can 1614 * allocate them here. If we're using zero-copy, 1615 * then the user process must have registered buffers 1616 * by the time we get here. 1617 */ 1618 alloc_buf = 0; 1619 BPFD_LOCK(d); 1620 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1621 d->bd_sbuf == NULL) 1622 alloc_buf = 1; 1623 BPFD_UNLOCK(d); 1624 if (alloc_buf) { 1625 size = d->bd_bufsize; 1626 error = bpf_buffer_ioctl_sblen(d, &size); 1627 if (error != 0) 1628 break; 1629 } 1630 BPF_LOCK(); 1631 error = bpf_setif(d, (struct ifreq *)addr); 1632 BPF_UNLOCK(); 1633 break; 1634 } 1635 1636 /* 1637 * Set read timeout. 1638 */ 1639 case BIOCSRTIMEOUT: 1640 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1641 case BIOCSRTIMEOUT32: 1642 #endif 1643 { 1644 struct timeval *tv = (struct timeval *)addr; 1645 #if defined(COMPAT_FREEBSD32) 1646 struct timeval32 *tv32; 1647 struct timeval tv64; 1648 1649 if (cmd == BIOCSRTIMEOUT32) { 1650 tv32 = (struct timeval32 *)addr; 1651 tv = &tv64; 1652 tv->tv_sec = tv32->tv_sec; 1653 tv->tv_usec = tv32->tv_usec; 1654 } else 1655 #endif 1656 tv = (struct timeval *)addr; 1657 1658 /* 1659 * Subtract 1 tick from tvtohz() since this isn't 1660 * a one-shot timer. 1661 */ 1662 if ((error = itimerfix(tv)) == 0) 1663 d->bd_rtout = tvtohz(tv) - 1; 1664 break; 1665 } 1666 1667 /* 1668 * Get read timeout. 1669 */ 1670 case BIOCGRTIMEOUT: 1671 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1672 case BIOCGRTIMEOUT32: 1673 #endif 1674 { 1675 struct timeval *tv; 1676 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1677 struct timeval32 *tv32; 1678 struct timeval tv64; 1679 1680 if (cmd == BIOCGRTIMEOUT32) 1681 tv = &tv64; 1682 else 1683 #endif 1684 tv = (struct timeval *)addr; 1685 1686 tv->tv_sec = d->bd_rtout / hz; 1687 tv->tv_usec = (d->bd_rtout % hz) * tick; 1688 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1689 if (cmd == BIOCGRTIMEOUT32) { 1690 tv32 = (struct timeval32 *)addr; 1691 tv32->tv_sec = tv->tv_sec; 1692 tv32->tv_usec = tv->tv_usec; 1693 } 1694 #endif 1695 1696 break; 1697 } 1698 1699 /* 1700 * Get packet stats. 1701 */ 1702 case BIOCGSTATS: 1703 { 1704 struct bpf_stat *bs = (struct bpf_stat *)addr; 1705 1706 /* XXXCSJP overflow */ 1707 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1708 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1709 break; 1710 } 1711 1712 /* 1713 * Set immediate mode. 1714 */ 1715 case BIOCIMMEDIATE: 1716 BPFD_LOCK(d); 1717 d->bd_immediate = *(u_int *)addr; 1718 BPFD_UNLOCK(d); 1719 break; 1720 1721 case BIOCVERSION: 1722 { 1723 struct bpf_version *bv = (struct bpf_version *)addr; 1724 1725 bv->bv_major = BPF_MAJOR_VERSION; 1726 bv->bv_minor = BPF_MINOR_VERSION; 1727 break; 1728 } 1729 1730 /* 1731 * Get "header already complete" flag 1732 */ 1733 case BIOCGHDRCMPLT: 1734 BPFD_LOCK(d); 1735 *(u_int *)addr = d->bd_hdrcmplt; 1736 BPFD_UNLOCK(d); 1737 break; 1738 1739 /* 1740 * Set "header already complete" flag 1741 */ 1742 case BIOCSHDRCMPLT: 1743 BPFD_LOCK(d); 1744 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1745 BPFD_UNLOCK(d); 1746 break; 1747 1748 /* 1749 * Get packet direction flag 1750 */ 1751 case BIOCGDIRECTION: 1752 BPFD_LOCK(d); 1753 *(u_int *)addr = d->bd_direction; 1754 BPFD_UNLOCK(d); 1755 break; 1756 1757 /* 1758 * Set packet direction flag 1759 */ 1760 case BIOCSDIRECTION: 1761 { 1762 u_int direction; 1763 1764 direction = *(u_int *)addr; 1765 switch (direction) { 1766 case BPF_D_IN: 1767 case BPF_D_INOUT: 1768 case BPF_D_OUT: 1769 BPFD_LOCK(d); 1770 d->bd_direction = direction; 1771 BPFD_UNLOCK(d); 1772 break; 1773 default: 1774 error = EINVAL; 1775 } 1776 } 1777 break; 1778 1779 /* 1780 * Get packet timestamp format and resolution. 1781 */ 1782 case BIOCGTSTAMP: 1783 BPFD_LOCK(d); 1784 *(u_int *)addr = d->bd_tstamp; 1785 BPFD_UNLOCK(d); 1786 break; 1787 1788 /* 1789 * Set packet timestamp format and resolution. 1790 */ 1791 case BIOCSTSTAMP: 1792 { 1793 u_int func; 1794 1795 func = *(u_int *)addr; 1796 if (BPF_T_VALID(func)) 1797 d->bd_tstamp = func; 1798 else 1799 error = EINVAL; 1800 } 1801 break; 1802 1803 case BIOCFEEDBACK: 1804 BPFD_LOCK(d); 1805 d->bd_feedback = *(u_int *)addr; 1806 BPFD_UNLOCK(d); 1807 break; 1808 1809 case BIOCLOCK: 1810 BPFD_LOCK(d); 1811 d->bd_locked = 1; 1812 BPFD_UNLOCK(d); 1813 break; 1814 1815 case FIONBIO: /* Non-blocking I/O */ 1816 break; 1817 1818 case FIOASYNC: /* Send signal on receive packets */ 1819 BPFD_LOCK(d); 1820 d->bd_async = *(int *)addr; 1821 BPFD_UNLOCK(d); 1822 break; 1823 1824 case FIOSETOWN: 1825 /* 1826 * XXX: Add some sort of locking here? 1827 * fsetown() can sleep. 1828 */ 1829 error = fsetown(*(int *)addr, &d->bd_sigio); 1830 break; 1831 1832 case FIOGETOWN: 1833 BPFD_LOCK(d); 1834 *(int *)addr = fgetown(&d->bd_sigio); 1835 BPFD_UNLOCK(d); 1836 break; 1837 1838 /* This is deprecated, FIOSETOWN should be used instead. */ 1839 case TIOCSPGRP: 1840 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1841 break; 1842 1843 /* This is deprecated, FIOGETOWN should be used instead. */ 1844 case TIOCGPGRP: 1845 *(int *)addr = -fgetown(&d->bd_sigio); 1846 break; 1847 1848 case BIOCSRSIG: /* Set receive signal */ 1849 { 1850 u_int sig; 1851 1852 sig = *(u_int *)addr; 1853 1854 if (sig >= NSIG) 1855 error = EINVAL; 1856 else { 1857 BPFD_LOCK(d); 1858 d->bd_sig = sig; 1859 BPFD_UNLOCK(d); 1860 } 1861 break; 1862 } 1863 case BIOCGRSIG: 1864 BPFD_LOCK(d); 1865 *(u_int *)addr = d->bd_sig; 1866 BPFD_UNLOCK(d); 1867 break; 1868 1869 case BIOCGETBUFMODE: 1870 BPFD_LOCK(d); 1871 *(u_int *)addr = d->bd_bufmode; 1872 BPFD_UNLOCK(d); 1873 break; 1874 1875 case BIOCSETBUFMODE: 1876 /* 1877 * Allow the buffering mode to be changed as long as we 1878 * haven't yet committed to a particular mode. Our 1879 * definition of commitment, for now, is whether or not a 1880 * buffer has been allocated or an interface attached, since 1881 * that's the point where things get tricky. 1882 */ 1883 switch (*(u_int *)addr) { 1884 case BPF_BUFMODE_BUFFER: 1885 break; 1886 1887 case BPF_BUFMODE_ZBUF: 1888 if (bpf_zerocopy_enable) 1889 break; 1890 /* FALLSTHROUGH */ 1891 1892 default: 1893 CURVNET_RESTORE(); 1894 return (EINVAL); 1895 } 1896 1897 BPFD_LOCK(d); 1898 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1899 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1900 BPFD_UNLOCK(d); 1901 CURVNET_RESTORE(); 1902 return (EBUSY); 1903 } 1904 d->bd_bufmode = *(u_int *)addr; 1905 BPFD_UNLOCK(d); 1906 break; 1907 1908 case BIOCGETZMAX: 1909 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1910 break; 1911 1912 case BIOCSETZBUF: 1913 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1914 break; 1915 1916 case BIOCROTZBUF: 1917 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1918 break; 1919 1920 case BIOCSETVLANPCP: 1921 { 1922 u_int pcp; 1923 1924 pcp = *(u_int *)addr; 1925 if (pcp > BPF_PRIO_MAX || pcp < 0) { 1926 error = EINVAL; 1927 break; 1928 } 1929 d->bd_pcp = pcp; 1930 break; 1931 } 1932 } 1933 CURVNET_RESTORE(); 1934 return (error); 1935 } 1936 1937 /* 1938 * Set d's packet filter program to fp. If this file already has a filter, 1939 * free it and replace it. Returns EINVAL for bogus requests. 1940 * 1941 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1942 * calls. 1943 */ 1944 static int 1945 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1946 { 1947 #ifdef COMPAT_FREEBSD32 1948 struct bpf_program fp_swab; 1949 struct bpf_program32 *fp32; 1950 #endif 1951 struct bpf_program_buffer *fcode; 1952 struct bpf_insn *filter; 1953 #ifdef BPF_JITTER 1954 bpf_jit_filter *jfunc; 1955 #endif 1956 size_t size; 1957 u_int flen; 1958 bool track_event; 1959 1960 #ifdef COMPAT_FREEBSD32 1961 switch (cmd) { 1962 case BIOCSETF32: 1963 case BIOCSETWF32: 1964 case BIOCSETFNR32: 1965 fp32 = (struct bpf_program32 *)fp; 1966 fp_swab.bf_len = fp32->bf_len; 1967 fp_swab.bf_insns = 1968 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1969 fp = &fp_swab; 1970 switch (cmd) { 1971 case BIOCSETF32: 1972 cmd = BIOCSETF; 1973 break; 1974 case BIOCSETWF32: 1975 cmd = BIOCSETWF; 1976 break; 1977 } 1978 break; 1979 } 1980 #endif 1981 1982 filter = NULL; 1983 #ifdef BPF_JITTER 1984 jfunc = NULL; 1985 #endif 1986 /* 1987 * Check new filter validness before acquiring any locks. 1988 * Allocate memory for new filter, if needed. 1989 */ 1990 flen = fp->bf_len; 1991 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1992 return (EINVAL); 1993 size = flen * sizeof(*fp->bf_insns); 1994 if (size > 0) { 1995 /* We're setting up new filter. Copy and check actual data. */ 1996 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1997 filter = (struct bpf_insn *)fcode->buffer; 1998 if (copyin(fp->bf_insns, filter, size) != 0 || 1999 !bpf_validate(filter, flen)) { 2000 free(fcode, M_BPF); 2001 return (EINVAL); 2002 } 2003 #ifdef BPF_JITTER 2004 if (cmd != BIOCSETWF) { 2005 /* 2006 * Filter is copied inside fcode and is 2007 * perfectly valid. 2008 */ 2009 jfunc = bpf_jitter(filter, flen); 2010 } 2011 #endif 2012 } 2013 2014 track_event = false; 2015 fcode = NULL; 2016 2017 BPF_LOCK(); 2018 BPFD_LOCK(d); 2019 /* Set up new filter. */ 2020 if (cmd == BIOCSETWF) { 2021 if (d->bd_wfilter != NULL) { 2022 fcode = __containerof((void *)d->bd_wfilter, 2023 struct bpf_program_buffer, buffer); 2024 #ifdef BPF_JITTER 2025 fcode->func = NULL; 2026 #endif 2027 } 2028 d->bd_wfilter = filter; 2029 } else { 2030 if (d->bd_rfilter != NULL) { 2031 fcode = __containerof((void *)d->bd_rfilter, 2032 struct bpf_program_buffer, buffer); 2033 #ifdef BPF_JITTER 2034 fcode->func = d->bd_bfilter; 2035 #endif 2036 } 2037 d->bd_rfilter = filter; 2038 #ifdef BPF_JITTER 2039 d->bd_bfilter = jfunc; 2040 #endif 2041 if (cmd == BIOCSETF) 2042 reset_d(d); 2043 2044 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 2045 /* 2046 * Filter can be set several times without 2047 * specifying interface. In this case just mark d 2048 * as reader. 2049 */ 2050 d->bd_writer = 0; 2051 if (d->bd_bif != NULL) { 2052 /* 2053 * Remove descriptor from writers-only list 2054 * and add it to active readers list. 2055 */ 2056 CK_LIST_REMOVE(d, bd_next); 2057 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 2058 d, bd_next); 2059 CTR2(KTR_NET, 2060 "%s: upgrade required by pid %d", 2061 __func__, d->bd_pid); 2062 track_event = true; 2063 } 2064 } 2065 } 2066 BPFD_UNLOCK(d); 2067 2068 if (fcode != NULL) 2069 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 2070 2071 if (track_event) 2072 EVENTHANDLER_INVOKE(bpf_track, 2073 d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); 2074 2075 BPF_UNLOCK(); 2076 return (0); 2077 } 2078 2079 /* 2080 * Detach a file from its current interface (if attached at all) and attach 2081 * to the interface indicated by the name stored in ifr. 2082 * Return an errno or 0. 2083 */ 2084 static int 2085 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 2086 { 2087 struct bpf_if *bp; 2088 struct ifnet *theywant; 2089 2090 BPF_LOCK_ASSERT(); 2091 2092 theywant = ifunit(ifr->ifr_name); 2093 if (theywant == NULL) 2094 return (ENXIO); 2095 /* 2096 * Look through attached interfaces for the named one. 2097 */ 2098 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2099 if (bp->bif_ifp == theywant && 2100 bp->bif_bpf == &theywant->if_bpf) 2101 break; 2102 } 2103 if (bp == NULL) 2104 return (ENXIO); 2105 2106 MPASS(bp == theywant->if_bpf); 2107 /* 2108 * At this point, we expect the buffer is already allocated. If not, 2109 * return an error. 2110 */ 2111 switch (d->bd_bufmode) { 2112 case BPF_BUFMODE_BUFFER: 2113 case BPF_BUFMODE_ZBUF: 2114 if (d->bd_sbuf == NULL) 2115 return (EINVAL); 2116 break; 2117 2118 default: 2119 panic("bpf_setif: bufmode %d", d->bd_bufmode); 2120 } 2121 if (bp != d->bd_bif) 2122 bpf_attachd(d, bp); 2123 else { 2124 BPFD_LOCK(d); 2125 reset_d(d); 2126 BPFD_UNLOCK(d); 2127 } 2128 return (0); 2129 } 2130 2131 /* 2132 * Support for select() and poll() system calls 2133 * 2134 * Return true iff the specific operation will not block indefinitely. 2135 * Otherwise, return false but make a note that a selwakeup() must be done. 2136 */ 2137 static int 2138 bpfpoll(struct cdev *dev, int events, struct thread *td) 2139 { 2140 struct bpf_d *d; 2141 int revents; 2142 2143 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2144 return (events & 2145 (POLLHUP | POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM)); 2146 2147 /* 2148 * Refresh PID associated with this descriptor. 2149 */ 2150 revents = events & (POLLOUT | POLLWRNORM); 2151 BPFD_LOCK(d); 2152 BPF_PID_REFRESH(d, td); 2153 if (events & (POLLIN | POLLRDNORM)) { 2154 if (bpf_ready(d)) 2155 revents |= events & (POLLIN | POLLRDNORM); 2156 else { 2157 selrecord(td, &d->bd_sel); 2158 /* Start the read timeout if necessary. */ 2159 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2160 callout_reset(&d->bd_callout, d->bd_rtout, 2161 bpf_timed_out, d); 2162 d->bd_state = BPF_WAITING; 2163 } 2164 } 2165 } 2166 BPFD_UNLOCK(d); 2167 return (revents); 2168 } 2169 2170 /* 2171 * Support for kevent() system call. Register EVFILT_READ filters and 2172 * reject all others. 2173 */ 2174 int 2175 bpfkqfilter(struct cdev *dev, struct knote *kn) 2176 { 2177 struct bpf_d *d; 2178 2179 if (devfs_get_cdevpriv((void **)&d) != 0) 2180 return (1); 2181 2182 switch (kn->kn_filter) { 2183 case EVFILT_READ: 2184 kn->kn_fop = &bpfread_filtops; 2185 break; 2186 2187 case EVFILT_WRITE: 2188 kn->kn_fop = &bpfwrite_filtops; 2189 break; 2190 2191 default: 2192 return (1); 2193 } 2194 2195 /* 2196 * Refresh PID associated with this descriptor. 2197 */ 2198 BPFD_LOCK(d); 2199 BPF_PID_REFRESH_CUR(d); 2200 kn->kn_hook = d; 2201 knlist_add(&d->bd_sel.si_note, kn, 1); 2202 BPFD_UNLOCK(d); 2203 2204 return (0); 2205 } 2206 2207 static void 2208 filt_bpfdetach(struct knote *kn) 2209 { 2210 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2211 2212 knlist_remove(&d->bd_sel.si_note, kn, 0); 2213 } 2214 2215 static int 2216 filt_bpfread(struct knote *kn, long hint) 2217 { 2218 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2219 int ready; 2220 2221 BPFD_LOCK_ASSERT(d); 2222 ready = bpf_ready(d); 2223 if (ready) { 2224 kn->kn_data = d->bd_slen; 2225 /* 2226 * Ignore the hold buffer if it is being copied to user space. 2227 */ 2228 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2229 kn->kn_data += d->bd_hlen; 2230 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2231 callout_reset(&d->bd_callout, d->bd_rtout, 2232 bpf_timed_out, d); 2233 d->bd_state = BPF_WAITING; 2234 } 2235 2236 return (ready); 2237 } 2238 2239 static int 2240 filt_bpfwrite(struct knote *kn, long hint) 2241 { 2242 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2243 2244 BPFD_LOCK_ASSERT(d); 2245 2246 if (d->bd_bif == NULL) { 2247 kn->kn_data = 0; 2248 return (0); 2249 } else { 2250 kn->kn_data = d->bd_bif->bif_ifp->if_mtu; 2251 return (1); 2252 } 2253 } 2254 2255 #define BPF_TSTAMP_NONE 0 2256 #define BPF_TSTAMP_FAST 1 2257 #define BPF_TSTAMP_NORMAL 2 2258 #define BPF_TSTAMP_EXTERN 3 2259 2260 static int 2261 bpf_ts_quality(int tstype) 2262 { 2263 2264 if (tstype == BPF_T_NONE) 2265 return (BPF_TSTAMP_NONE); 2266 if ((tstype & BPF_T_FAST) != 0) 2267 return (BPF_TSTAMP_FAST); 2268 2269 return (BPF_TSTAMP_NORMAL); 2270 } 2271 2272 static int 2273 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2274 { 2275 struct timespec ts; 2276 struct m_tag *tag; 2277 int quality; 2278 2279 quality = bpf_ts_quality(tstype); 2280 if (quality == BPF_TSTAMP_NONE) 2281 return (quality); 2282 2283 if (m != NULL) { 2284 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { 2285 mbuf_tstmp2timespec(m, &ts); 2286 timespec2bintime(&ts, bt); 2287 return (BPF_TSTAMP_EXTERN); 2288 } 2289 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2290 if (tag != NULL) { 2291 *bt = *(struct bintime *)(tag + 1); 2292 return (BPF_TSTAMP_EXTERN); 2293 } 2294 } 2295 if (quality == BPF_TSTAMP_NORMAL) 2296 binuptime(bt); 2297 else 2298 getbinuptime(bt); 2299 2300 return (quality); 2301 } 2302 2303 /* 2304 * Incoming linkage from device drivers. Process the packet pkt, of length 2305 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2306 * by each process' filter, and if accepted, stashed into the corresponding 2307 * buffer. 2308 */ 2309 void 2310 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2311 { 2312 struct epoch_tracker et; 2313 struct bintime bt; 2314 struct bpf_d *d; 2315 #ifdef BPF_JITTER 2316 bpf_jit_filter *bf; 2317 #endif 2318 u_int slen; 2319 int gottime; 2320 2321 gottime = BPF_TSTAMP_NONE; 2322 NET_EPOCH_ENTER(et); 2323 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2324 counter_u64_add(d->bd_rcount, 1); 2325 /* 2326 * NB: We dont call BPF_CHECK_DIRECTION() here since there 2327 * is no way for the caller to indiciate to us whether this 2328 * packet is inbound or outbound. In the bpf_mtap() routines, 2329 * we use the interface pointers on the mbuf to figure it out. 2330 */ 2331 #ifdef BPF_JITTER 2332 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2333 if (bf != NULL) 2334 slen = (*(bf->func))(pkt, pktlen, pktlen); 2335 else 2336 #endif 2337 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2338 if (slen != 0) { 2339 /* 2340 * Filter matches. Let's to acquire write lock. 2341 */ 2342 BPFD_LOCK(d); 2343 counter_u64_add(d->bd_fcount, 1); 2344 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2345 gottime = bpf_gettime(&bt, d->bd_tstamp, 2346 NULL); 2347 #ifdef MAC 2348 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2349 #endif 2350 catchpacket(d, pkt, pktlen, slen, 2351 bpf_append_bytes, &bt); 2352 BPFD_UNLOCK(d); 2353 } 2354 } 2355 NET_EPOCH_EXIT(et); 2356 } 2357 2358 void 2359 bpf_tap_if(if_t ifp, u_char *pkt, u_int pktlen) 2360 { 2361 if (bpf_peers_present(ifp->if_bpf)) 2362 bpf_tap(ifp->if_bpf, pkt, pktlen); 2363 } 2364 2365 #define BPF_CHECK_DIRECTION(d, r, i) \ 2366 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2367 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2368 2369 /* 2370 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2371 * Locking model is explained in bpf_tap(). 2372 */ 2373 void 2374 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2375 { 2376 struct epoch_tracker et; 2377 struct bintime bt; 2378 struct bpf_d *d; 2379 #ifdef BPF_JITTER 2380 bpf_jit_filter *bf; 2381 #endif 2382 u_int pktlen, slen; 2383 int gottime; 2384 2385 /* Skip outgoing duplicate packets. */ 2386 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2387 m->m_flags &= ~M_PROMISC; 2388 return; 2389 } 2390 2391 pktlen = m_length(m, NULL); 2392 gottime = BPF_TSTAMP_NONE; 2393 2394 NET_EPOCH_ENTER(et); 2395 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2396 if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) 2397 continue; 2398 counter_u64_add(d->bd_rcount, 1); 2399 #ifdef BPF_JITTER 2400 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2401 /* XXX We cannot handle multiple mbufs. */ 2402 if (bf != NULL && m->m_next == NULL) 2403 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2404 pktlen); 2405 else 2406 #endif 2407 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2408 if (slen != 0) { 2409 BPFD_LOCK(d); 2410 2411 counter_u64_add(d->bd_fcount, 1); 2412 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2413 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2414 #ifdef MAC 2415 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2416 #endif 2417 catchpacket(d, (u_char *)m, pktlen, slen, 2418 bpf_append_mbuf, &bt); 2419 BPFD_UNLOCK(d); 2420 } 2421 } 2422 NET_EPOCH_EXIT(et); 2423 } 2424 2425 void 2426 bpf_mtap_if(if_t ifp, struct mbuf *m) 2427 { 2428 if (bpf_peers_present(ifp->if_bpf)) { 2429 M_ASSERTVALID(m); 2430 bpf_mtap(ifp->if_bpf, m); 2431 } 2432 } 2433 2434 /* 2435 * Incoming linkage from device drivers, when packet is in 2436 * an mbuf chain and to be prepended by a contiguous header. 2437 */ 2438 void 2439 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2440 { 2441 struct epoch_tracker et; 2442 struct bintime bt; 2443 struct mbuf mb; 2444 struct bpf_d *d; 2445 u_int pktlen, slen; 2446 int gottime; 2447 2448 /* Skip outgoing duplicate packets. */ 2449 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2450 m->m_flags &= ~M_PROMISC; 2451 return; 2452 } 2453 2454 pktlen = m_length(m, NULL); 2455 /* 2456 * Craft on-stack mbuf suitable for passing to bpf_filter. 2457 * Note that we cut corners here; we only setup what's 2458 * absolutely needed--this mbuf should never go anywhere else. 2459 */ 2460 mb.m_flags = 0; 2461 mb.m_next = m; 2462 mb.m_data = data; 2463 mb.m_len = dlen; 2464 pktlen += dlen; 2465 2466 gottime = BPF_TSTAMP_NONE; 2467 2468 NET_EPOCH_ENTER(et); 2469 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2470 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2471 continue; 2472 counter_u64_add(d->bd_rcount, 1); 2473 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2474 if (slen != 0) { 2475 BPFD_LOCK(d); 2476 2477 counter_u64_add(d->bd_fcount, 1); 2478 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2479 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2480 #ifdef MAC 2481 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2482 #endif 2483 catchpacket(d, (u_char *)&mb, pktlen, slen, 2484 bpf_append_mbuf, &bt); 2485 BPFD_UNLOCK(d); 2486 } 2487 } 2488 NET_EPOCH_EXIT(et); 2489 } 2490 2491 void 2492 bpf_mtap2_if(if_t ifp, void *data, u_int dlen, struct mbuf *m) 2493 { 2494 if (bpf_peers_present(ifp->if_bpf)) { 2495 M_ASSERTVALID(m); 2496 bpf_mtap2(ifp->if_bpf, data, dlen, m); 2497 } 2498 } 2499 2500 #undef BPF_CHECK_DIRECTION 2501 #undef BPF_TSTAMP_NONE 2502 #undef BPF_TSTAMP_FAST 2503 #undef BPF_TSTAMP_NORMAL 2504 #undef BPF_TSTAMP_EXTERN 2505 2506 static int 2507 bpf_hdrlen(struct bpf_d *d) 2508 { 2509 int hdrlen; 2510 2511 hdrlen = d->bd_bif->bif_hdrlen; 2512 #ifndef BURN_BRIDGES 2513 if (d->bd_tstamp == BPF_T_NONE || 2514 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2515 #ifdef COMPAT_FREEBSD32 2516 if (d->bd_compat32) 2517 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2518 else 2519 #endif 2520 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2521 else 2522 #endif 2523 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2524 #ifdef COMPAT_FREEBSD32 2525 if (d->bd_compat32) 2526 hdrlen = BPF_WORDALIGN32(hdrlen); 2527 else 2528 #endif 2529 hdrlen = BPF_WORDALIGN(hdrlen); 2530 2531 return (hdrlen - d->bd_bif->bif_hdrlen); 2532 } 2533 2534 static void 2535 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2536 { 2537 struct bintime bt2, boottimebin; 2538 struct timeval tsm; 2539 struct timespec tsn; 2540 2541 if ((tstype & BPF_T_MONOTONIC) == 0) { 2542 bt2 = *bt; 2543 getboottimebin(&boottimebin); 2544 bintime_add(&bt2, &boottimebin); 2545 bt = &bt2; 2546 } 2547 switch (BPF_T_FORMAT(tstype)) { 2548 case BPF_T_MICROTIME: 2549 bintime2timeval(bt, &tsm); 2550 ts->bt_sec = tsm.tv_sec; 2551 ts->bt_frac = tsm.tv_usec; 2552 break; 2553 case BPF_T_NANOTIME: 2554 bintime2timespec(bt, &tsn); 2555 ts->bt_sec = tsn.tv_sec; 2556 ts->bt_frac = tsn.tv_nsec; 2557 break; 2558 case BPF_T_BINTIME: 2559 ts->bt_sec = bt->sec; 2560 ts->bt_frac = bt->frac; 2561 break; 2562 } 2563 } 2564 2565 /* 2566 * Move the packet data from interface memory (pkt) into the 2567 * store buffer. "cpfn" is the routine called to do the actual data 2568 * transfer. bcopy is passed in to copy contiguous chunks, while 2569 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2570 * pkt is really an mbuf. 2571 */ 2572 static void 2573 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2574 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2575 struct bintime *bt) 2576 { 2577 static char zeroes[BPF_ALIGNMENT]; 2578 struct bpf_xhdr hdr; 2579 #ifndef BURN_BRIDGES 2580 struct bpf_hdr hdr_old; 2581 #ifdef COMPAT_FREEBSD32 2582 struct bpf_hdr32 hdr32_old; 2583 #endif 2584 #endif 2585 int caplen, curlen, hdrlen, pad, totlen; 2586 int do_wakeup = 0; 2587 int do_timestamp; 2588 int tstype; 2589 2590 BPFD_LOCK_ASSERT(d); 2591 if (d->bd_bif == NULL) { 2592 /* Descriptor was detached in concurrent thread */ 2593 counter_u64_add(d->bd_dcount, 1); 2594 return; 2595 } 2596 2597 /* 2598 * Detect whether user space has released a buffer back to us, and if 2599 * so, move it from being a hold buffer to a free buffer. This may 2600 * not be the best place to do it (for example, we might only want to 2601 * run this check if we need the space), but for now it's a reliable 2602 * spot to do it. 2603 */ 2604 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2605 d->bd_fbuf = d->bd_hbuf; 2606 d->bd_hbuf = NULL; 2607 d->bd_hlen = 0; 2608 bpf_buf_reclaimed(d); 2609 } 2610 2611 /* 2612 * Figure out how many bytes to move. If the packet is 2613 * greater or equal to the snapshot length, transfer that 2614 * much. Otherwise, transfer the whole packet (unless 2615 * we hit the buffer size limit). 2616 */ 2617 hdrlen = bpf_hdrlen(d); 2618 totlen = hdrlen + min(snaplen, pktlen); 2619 if (totlen > d->bd_bufsize) 2620 totlen = d->bd_bufsize; 2621 2622 /* 2623 * Round up the end of the previous packet to the next longword. 2624 * 2625 * Drop the packet if there's no room and no hope of room 2626 * If the packet would overflow the storage buffer or the storage 2627 * buffer is considered immutable by the buffer model, try to rotate 2628 * the buffer and wakeup pending processes. 2629 */ 2630 #ifdef COMPAT_FREEBSD32 2631 if (d->bd_compat32) 2632 curlen = BPF_WORDALIGN32(d->bd_slen); 2633 else 2634 #endif 2635 curlen = BPF_WORDALIGN(d->bd_slen); 2636 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2637 if (d->bd_fbuf == NULL) { 2638 /* 2639 * There's no room in the store buffer, and no 2640 * prospect of room, so drop the packet. Notify the 2641 * buffer model. 2642 */ 2643 bpf_buffull(d); 2644 counter_u64_add(d->bd_dcount, 1); 2645 return; 2646 } 2647 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2648 ROTATE_BUFFERS(d); 2649 do_wakeup = 1; 2650 curlen = 0; 2651 } else { 2652 if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { 2653 /* 2654 * Immediate mode is set, or the read timeout has 2655 * already expired during a select call. A packet 2656 * arrived, so the reader should be woken up. 2657 */ 2658 do_wakeup = 1; 2659 } 2660 pad = curlen - d->bd_slen; 2661 KASSERT(pad >= 0 && pad <= sizeof(zeroes), 2662 ("%s: invalid pad byte count %d", __func__, pad)); 2663 if (pad > 0) { 2664 /* Zero pad bytes. */ 2665 bpf_append_bytes(d, d->bd_sbuf, d->bd_slen, zeroes, 2666 pad); 2667 } 2668 } 2669 2670 caplen = totlen - hdrlen; 2671 tstype = d->bd_tstamp; 2672 do_timestamp = tstype != BPF_T_NONE; 2673 #ifndef BURN_BRIDGES 2674 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2675 struct bpf_ts ts; 2676 if (do_timestamp) 2677 bpf_bintime2ts(bt, &ts, tstype); 2678 #ifdef COMPAT_FREEBSD32 2679 if (d->bd_compat32) { 2680 bzero(&hdr32_old, sizeof(hdr32_old)); 2681 if (do_timestamp) { 2682 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2683 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2684 } 2685 hdr32_old.bh_datalen = pktlen; 2686 hdr32_old.bh_hdrlen = hdrlen; 2687 hdr32_old.bh_caplen = caplen; 2688 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2689 sizeof(hdr32_old)); 2690 goto copy; 2691 } 2692 #endif 2693 bzero(&hdr_old, sizeof(hdr_old)); 2694 if (do_timestamp) { 2695 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2696 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2697 } 2698 hdr_old.bh_datalen = pktlen; 2699 hdr_old.bh_hdrlen = hdrlen; 2700 hdr_old.bh_caplen = caplen; 2701 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2702 sizeof(hdr_old)); 2703 goto copy; 2704 } 2705 #endif 2706 2707 /* 2708 * Append the bpf header. Note we append the actual header size, but 2709 * move forward the length of the header plus padding. 2710 */ 2711 bzero(&hdr, sizeof(hdr)); 2712 if (do_timestamp) 2713 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2714 hdr.bh_datalen = pktlen; 2715 hdr.bh_hdrlen = hdrlen; 2716 hdr.bh_caplen = caplen; 2717 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2718 2719 /* 2720 * Copy the packet data into the store buffer and update its length. 2721 */ 2722 #ifndef BURN_BRIDGES 2723 copy: 2724 #endif 2725 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2726 d->bd_slen = curlen + totlen; 2727 2728 if (do_wakeup) 2729 bpf_wakeup(d); 2730 } 2731 2732 /* 2733 * Free buffers currently in use by a descriptor. 2734 * Called on close. 2735 */ 2736 static void 2737 bpfd_free(epoch_context_t ctx) 2738 { 2739 struct bpf_d *d; 2740 struct bpf_program_buffer *p; 2741 2742 /* 2743 * We don't need to lock out interrupts since this descriptor has 2744 * been detached from its interface and it yet hasn't been marked 2745 * free. 2746 */ 2747 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2748 bpf_free(d); 2749 if (d->bd_rfilter != NULL) { 2750 p = __containerof((void *)d->bd_rfilter, 2751 struct bpf_program_buffer, buffer); 2752 #ifdef BPF_JITTER 2753 p->func = d->bd_bfilter; 2754 #endif 2755 bpf_program_buffer_free(&p->epoch_ctx); 2756 } 2757 if (d->bd_wfilter != NULL) { 2758 p = __containerof((void *)d->bd_wfilter, 2759 struct bpf_program_buffer, buffer); 2760 #ifdef BPF_JITTER 2761 p->func = NULL; 2762 #endif 2763 bpf_program_buffer_free(&p->epoch_ctx); 2764 } 2765 2766 mtx_destroy(&d->bd_lock); 2767 counter_u64_free(d->bd_rcount); 2768 counter_u64_free(d->bd_dcount); 2769 counter_u64_free(d->bd_fcount); 2770 counter_u64_free(d->bd_wcount); 2771 counter_u64_free(d->bd_wfcount); 2772 counter_u64_free(d->bd_wdcount); 2773 counter_u64_free(d->bd_zcopy); 2774 free(d, M_BPF); 2775 } 2776 2777 /* 2778 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2779 * fixed size of the link header (variable length headers not yet supported). 2780 */ 2781 void 2782 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2783 { 2784 2785 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2786 } 2787 2788 /* 2789 * Attach an interface to bpf. ifp is a pointer to the structure 2790 * defining the interface to be attached, dlt is the link layer type, 2791 * and hdrlen is the fixed size of the link header (variable length 2792 * headers are not yet supporrted). 2793 */ 2794 void 2795 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, 2796 struct bpf_if **driverp) 2797 { 2798 struct bpf_if *bp; 2799 2800 KASSERT(*driverp == NULL, 2801 ("bpfattach2: driverp already initialized")); 2802 2803 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2804 2805 CK_LIST_INIT(&bp->bif_dlist); 2806 CK_LIST_INIT(&bp->bif_wlist); 2807 bp->bif_ifp = ifp; 2808 bp->bif_dlt = dlt; 2809 bp->bif_hdrlen = hdrlen; 2810 bp->bif_bpf = driverp; 2811 refcount_init(&bp->bif_refcnt, 1); 2812 *driverp = bp; 2813 /* 2814 * Reference ifnet pointer, so it won't freed until 2815 * we release it. 2816 */ 2817 if_ref(ifp); 2818 BPF_LOCK(); 2819 CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2820 BPF_UNLOCK(); 2821 2822 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2823 if_printf(ifp, "bpf attached\n"); 2824 } 2825 2826 #ifdef VIMAGE 2827 /* 2828 * When moving interfaces between vnet instances we need a way to 2829 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2830 * after the vmove. We unfortunately have no device driver infrastructure 2831 * to query the interface for these values after creation/attach, thus 2832 * add this as a workaround. 2833 */ 2834 int 2835 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2836 { 2837 2838 if (bp == NULL) 2839 return (ENXIO); 2840 if (bif_dlt == NULL && bif_hdrlen == NULL) 2841 return (0); 2842 2843 if (bif_dlt != NULL) 2844 *bif_dlt = bp->bif_dlt; 2845 if (bif_hdrlen != NULL) 2846 *bif_hdrlen = bp->bif_hdrlen; 2847 2848 return (0); 2849 } 2850 2851 /* 2852 * Detach descriptors on interface's vmove event. 2853 */ 2854 void 2855 bpf_ifdetach(struct ifnet *ifp) 2856 { 2857 struct bpf_if *bp; 2858 struct bpf_d *d; 2859 2860 BPF_LOCK(); 2861 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2862 if (bp->bif_ifp != ifp) 2863 continue; 2864 2865 /* Detach common descriptors */ 2866 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2867 bpf_detachd_locked(d, true); 2868 } 2869 2870 /* Detach writer-only descriptors */ 2871 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2872 bpf_detachd_locked(d, true); 2873 } 2874 } 2875 BPF_UNLOCK(); 2876 } 2877 #endif 2878 2879 /* 2880 * Detach bpf from an interface. This involves detaching each descriptor 2881 * associated with the interface. Notify each descriptor as it's detached 2882 * so that any sleepers wake up and get ENXIO. 2883 */ 2884 void 2885 bpfdetach(struct ifnet *ifp) 2886 { 2887 struct bpf_if *bp, *bp_temp; 2888 struct bpf_d *d; 2889 2890 BPF_LOCK(); 2891 /* Find all bpf_if struct's which reference ifp and detach them. */ 2892 CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2893 if (ifp != bp->bif_ifp) 2894 continue; 2895 2896 CK_LIST_REMOVE(bp, bif_next); 2897 *bp->bif_bpf = __DECONST(struct bpf_if *, &dead_bpf_if); 2898 2899 CTR4(KTR_NET, 2900 "%s: sheduling free for encap %d (%p) for if %p", 2901 __func__, bp->bif_dlt, bp, ifp); 2902 2903 /* Detach common descriptors */ 2904 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2905 bpf_detachd_locked(d, true); 2906 } 2907 2908 /* Detach writer-only descriptors */ 2909 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2910 bpf_detachd_locked(d, true); 2911 } 2912 bpfif_rele(bp); 2913 } 2914 BPF_UNLOCK(); 2915 } 2916 2917 bool 2918 bpf_peers_present_if(struct ifnet *ifp) 2919 { 2920 return (bpf_peers_present(ifp->if_bpf)); 2921 } 2922 2923 /* 2924 * Get a list of available data link type of the interface. 2925 */ 2926 static int 2927 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2928 { 2929 struct ifnet *ifp; 2930 struct bpf_if *bp; 2931 u_int *lst; 2932 int error, n, n1; 2933 2934 BPF_LOCK_ASSERT(); 2935 2936 ifp = d->bd_bif->bif_ifp; 2937 n1 = 0; 2938 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2939 if (bp->bif_ifp == ifp) 2940 n1++; 2941 } 2942 if (bfl->bfl_list == NULL) { 2943 bfl->bfl_len = n1; 2944 return (0); 2945 } 2946 if (n1 > bfl->bfl_len) 2947 return (ENOMEM); 2948 2949 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2950 n = 0; 2951 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2952 if (bp->bif_ifp != ifp) 2953 continue; 2954 lst[n++] = bp->bif_dlt; 2955 } 2956 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2957 free(lst, M_TEMP); 2958 bfl->bfl_len = n; 2959 return (error); 2960 } 2961 2962 /* 2963 * Set the data link type of a BPF instance. 2964 */ 2965 static int 2966 bpf_setdlt(struct bpf_d *d, u_int dlt) 2967 { 2968 int error, opromisc; 2969 struct ifnet *ifp; 2970 struct bpf_if *bp; 2971 2972 BPF_LOCK_ASSERT(); 2973 MPASS(d->bd_bif != NULL); 2974 2975 /* 2976 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2977 * changed while we hold global lock. 2978 */ 2979 if (d->bd_bif->bif_dlt == dlt) 2980 return (0); 2981 2982 ifp = d->bd_bif->bif_ifp; 2983 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2984 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2985 break; 2986 } 2987 if (bp == NULL) 2988 return (EINVAL); 2989 2990 opromisc = d->bd_promisc; 2991 bpf_attachd(d, bp); 2992 if (opromisc) { 2993 error = ifpromisc(bp->bif_ifp, 1); 2994 if (error) 2995 if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", 2996 __func__, error); 2997 else 2998 d->bd_promisc = 1; 2999 } 3000 return (0); 3001 } 3002 3003 static void 3004 bpf_drvinit(void *unused) 3005 { 3006 struct cdev *dev; 3007 3008 sx_init(&bpf_sx, "bpf global lock"); 3009 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 3010 /* For compatibility */ 3011 make_dev_alias(dev, "bpf0"); 3012 } 3013 3014 /* 3015 * Zero out the various packet counters associated with all of the bpf 3016 * descriptors. At some point, we will probably want to get a bit more 3017 * granular and allow the user to specify descriptors to be zeroed. 3018 */ 3019 static void 3020 bpf_zero_counters(void) 3021 { 3022 struct bpf_if *bp; 3023 struct bpf_d *bd; 3024 3025 BPF_LOCK(); 3026 /* 3027 * We are protected by global lock here, interfaces and 3028 * descriptors can not be deleted while we hold it. 3029 */ 3030 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 3031 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 3032 counter_u64_zero(bd->bd_rcount); 3033 counter_u64_zero(bd->bd_dcount); 3034 counter_u64_zero(bd->bd_fcount); 3035 counter_u64_zero(bd->bd_wcount); 3036 counter_u64_zero(bd->bd_wfcount); 3037 counter_u64_zero(bd->bd_zcopy); 3038 } 3039 } 3040 BPF_UNLOCK(); 3041 } 3042 3043 /* 3044 * Fill filter statistics 3045 */ 3046 static void 3047 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 3048 { 3049 3050 BPF_LOCK_ASSERT(); 3051 bzero(d, sizeof(*d)); 3052 d->bd_structsize = sizeof(*d); 3053 d->bd_immediate = bd->bd_immediate; 3054 d->bd_promisc = bd->bd_promisc; 3055 d->bd_hdrcmplt = bd->bd_hdrcmplt; 3056 d->bd_direction = bd->bd_direction; 3057 d->bd_feedback = bd->bd_feedback; 3058 d->bd_async = bd->bd_async; 3059 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 3060 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 3061 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 3062 d->bd_sig = bd->bd_sig; 3063 d->bd_slen = bd->bd_slen; 3064 d->bd_hlen = bd->bd_hlen; 3065 d->bd_bufsize = bd->bd_bufsize; 3066 d->bd_pid = bd->bd_pid; 3067 strlcpy(d->bd_ifname, 3068 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 3069 d->bd_locked = bd->bd_locked; 3070 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 3071 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 3072 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 3073 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 3074 d->bd_bufmode = bd->bd_bufmode; 3075 } 3076 3077 /* 3078 * Handle `netstat -B' stats request 3079 */ 3080 static int 3081 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 3082 { 3083 static const struct xbpf_d zerostats; 3084 struct xbpf_d *xbdbuf, *xbd, tempstats; 3085 int index, error; 3086 struct bpf_if *bp; 3087 struct bpf_d *bd; 3088 3089 /* 3090 * XXX This is not technically correct. It is possible for non 3091 * privileged users to open bpf devices. It would make sense 3092 * if the users who opened the devices were able to retrieve 3093 * the statistics for them, too. 3094 */ 3095 error = priv_check(req->td, PRIV_NET_BPF); 3096 if (error) 3097 return (error); 3098 /* 3099 * Check to see if the user is requesting that the counters be 3100 * zeroed out. Explicitly check that the supplied data is zeroed, 3101 * as we aren't allowing the user to set the counters currently. 3102 */ 3103 if (req->newptr != NULL) { 3104 if (req->newlen != sizeof(tempstats)) 3105 return (EINVAL); 3106 memset(&tempstats, 0, sizeof(tempstats)); 3107 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 3108 if (error) 3109 return (error); 3110 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 3111 return (EINVAL); 3112 bpf_zero_counters(); 3113 return (0); 3114 } 3115 if (req->oldptr == NULL) 3116 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 3117 if (bpf_bpfd_cnt == 0) 3118 return (SYSCTL_OUT(req, 0, 0)); 3119 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 3120 BPF_LOCK(); 3121 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 3122 BPF_UNLOCK(); 3123 free(xbdbuf, M_BPF); 3124 return (ENOMEM); 3125 } 3126 index = 0; 3127 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 3128 /* Send writers-only first */ 3129 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 3130 xbd = &xbdbuf[index++]; 3131 bpfstats_fill_xbpf(xbd, bd); 3132 } 3133 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 3134 xbd = &xbdbuf[index++]; 3135 bpfstats_fill_xbpf(xbd, bd); 3136 } 3137 } 3138 BPF_UNLOCK(); 3139 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 3140 free(xbdbuf, M_BPF); 3141 return (error); 3142 } 3143 3144 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, bpf_drvinit, NULL); 3145 3146 #else /* !DEV_BPF && !NETGRAPH_BPF */ 3147 3148 /* 3149 * NOP stubs to allow bpf-using drivers to load and function. 3150 * 3151 * A 'better' implementation would allow the core bpf functionality 3152 * to be loaded at runtime. 3153 */ 3154 3155 void 3156 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3157 { 3158 } 3159 3160 void 3161 bpf_tap_if(if_t ifp, u_char *pkt, u_int pktlen) 3162 { 3163 } 3164 3165 void 3166 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3167 { 3168 } 3169 3170 void 3171 bpf_mtap_if(if_t ifp, struct mbuf *m) 3172 { 3173 } 3174 3175 void 3176 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3177 { 3178 } 3179 3180 void 3181 bpf_mtap2_if(if_t ifp, void *data, u_int dlen, struct mbuf *m) 3182 { 3183 } 3184 3185 void 3186 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3187 { 3188 3189 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3190 } 3191 3192 void 3193 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3194 { 3195 3196 *driverp = __DECONST(struct bpf_if *, &dead_bpf_if); 3197 } 3198 3199 void 3200 bpfdetach(struct ifnet *ifp) 3201 { 3202 } 3203 3204 bool 3205 bpf_peers_present_if(struct ifnet *ifp) 3206 { 3207 return (false); 3208 } 3209 3210 u_int 3211 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3212 { 3213 return (-1); /* "no filter" behaviour */ 3214 } 3215 3216 int 3217 bpf_validate(const struct bpf_insn *f, int len) 3218 { 3219 return (0); /* false */ 3220 } 3221 3222 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3223 3224 #ifdef DDB 3225 static void 3226 bpf_show_bpf_if(struct bpf_if *bpf_if) 3227 { 3228 3229 if (bpf_if == NULL) 3230 return; 3231 db_printf("%p:\n", bpf_if); 3232 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3233 #define BPF_DB_PRINTF_RAW(f, e) db_printf(" %s = " f "\n", #e, e); 3234 /* bif_ext.bif_next */ 3235 /* bif_ext.bif_dlist */ 3236 BPF_DB_PRINTF("%#x", bif_dlt); 3237 BPF_DB_PRINTF("%u", bif_hdrlen); 3238 /* bif_wlist */ 3239 BPF_DB_PRINTF("%p", bif_ifp); 3240 BPF_DB_PRINTF("%p", bif_bpf); 3241 BPF_DB_PRINTF_RAW("%u", refcount_load(&bpf_if->bif_refcnt)); 3242 } 3243 3244 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3245 { 3246 3247 if (!have_addr) { 3248 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3249 return; 3250 } 3251 3252 bpf_show_bpf_if((struct bpf_if *)addr); 3253 } 3254 #endif 3255