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_vlan_var.h> 82 #include <net/if_dl.h> 83 #include <net/bpf.h> 84 #include <net/bpf_buffer.h> 85 #ifdef BPF_JITTER 86 #include <net/bpf_jitter.h> 87 #endif 88 #include <net/bpf_zerocopy.h> 89 #include <net/bpfdesc.h> 90 #include <net/route.h> 91 #include <net/vnet.h> 92 93 #include <netinet/in.h> 94 #include <netinet/if_ether.h> 95 #include <sys/kernel.h> 96 #include <sys/sysctl.h> 97 98 #include <net80211/ieee80211_freebsd.h> 99 100 #include <security/mac/mac_framework.h> 101 102 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 103 104 static struct bpf_if_ext dead_bpf_if = { 105 .bif_dlist = CK_LIST_HEAD_INITIALIZER() 106 }; 107 108 struct bpf_if { 109 #define bif_next bif_ext.bif_next 110 #define bif_dlist bif_ext.bif_dlist 111 struct bpf_if_ext bif_ext; /* public members */ 112 u_int bif_dlt; /* link layer type */ 113 u_int bif_hdrlen; /* length of link header */ 114 struct bpfd_list bif_wlist; /* writer-only list */ 115 struct ifnet *bif_ifp; /* corresponding interface */ 116 struct bpf_if **bif_bpf; /* Pointer to pointer to us */ 117 volatile u_int bif_refcnt; 118 struct epoch_context epoch_ctx; 119 }; 120 121 CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); 122 123 struct bpf_program_buffer { 124 struct epoch_context epoch_ctx; 125 #ifdef BPF_JITTER 126 bpf_jit_filter *func; 127 #endif 128 void *buffer[0]; 129 }; 130 131 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 132 133 #define PRINET 26 /* interruptible */ 134 #define BPF_PRIO_MAX 7 135 136 #define SIZEOF_BPF_HDR(type) \ 137 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 138 139 #ifdef COMPAT_FREEBSD32 140 #include <sys/mount.h> 141 #include <compat/freebsd32/freebsd32.h> 142 #define BPF_ALIGNMENT32 sizeof(int32_t) 143 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) 144 145 #ifndef BURN_BRIDGES 146 /* 147 * 32-bit version of structure prepended to each packet. We use this header 148 * instead of the standard one for 32-bit streams. We mark the a stream as 149 * 32-bit the first time we see a 32-bit compat ioctl request. 150 */ 151 struct bpf_hdr32 { 152 struct timeval32 bh_tstamp; /* time stamp */ 153 uint32_t bh_caplen; /* length of captured portion */ 154 uint32_t bh_datalen; /* original length of packet */ 155 uint16_t bh_hdrlen; /* length of bpf header (this struct 156 plus alignment padding) */ 157 }; 158 #endif 159 160 struct bpf_program32 { 161 u_int bf_len; 162 uint32_t bf_insns; 163 }; 164 165 struct bpf_dltlist32 { 166 u_int bfl_len; 167 u_int bfl_list; 168 }; 169 170 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 171 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 172 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 173 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 174 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 175 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 176 #endif 177 178 #define BPF_LOCK() sx_xlock(&bpf_sx) 179 #define BPF_UNLOCK() sx_xunlock(&bpf_sx) 180 #define BPF_LOCK_ASSERT() sx_assert(&bpf_sx, SA_XLOCKED) 181 /* 182 * bpf_iflist is a list of BPF interface structures, each corresponding to a 183 * specific DLT. The same network interface might have several BPF interface 184 * structures registered by different layers in the stack (i.e., 802.11 185 * frames, ethernet frames, etc). 186 */ 187 CK_LIST_HEAD(bpf_iflist, bpf_if); 188 static struct bpf_iflist bpf_iflist; 189 static struct sx bpf_sx; /* bpf global lock */ 190 static int bpf_bpfd_cnt; 191 192 static void bpfif_ref(struct bpf_if *); 193 static void bpfif_rele(struct bpf_if *); 194 195 static void bpfd_ref(struct bpf_d *); 196 static void bpfd_rele(struct bpf_d *); 197 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 198 static void bpf_detachd(struct bpf_d *); 199 static void bpf_detachd_locked(struct bpf_d *, bool); 200 static void bpfd_free(epoch_context_t); 201 static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 202 struct sockaddr *, int *, struct bpf_d *); 203 static int bpf_setif(struct bpf_d *, struct ifreq *); 204 static void bpf_timed_out(void *); 205 static __inline void 206 bpf_wakeup(struct bpf_d *); 207 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 208 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 209 struct bintime *); 210 static void reset_d(struct bpf_d *); 211 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 212 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 213 static int bpf_setdlt(struct bpf_d *, u_int); 214 static void filt_bpfdetach(struct knote *); 215 static int filt_bpfread(struct knote *, long); 216 static int filt_bpfwrite(struct knote *, long); 217 static void bpf_drvinit(void *); 218 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 219 220 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 221 "bpf sysctl"); 222 int bpf_maxinsns = BPF_MAXINSNS; 223 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 224 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 225 static int bpf_zerocopy_enable = 0; 226 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 227 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 228 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, 229 bpf_stats_sysctl, "bpf statistics portal"); 230 231 VNET_DEFINE_STATIC(int, bpf_optimize_writers) = 0; 232 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 233 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RWTUN, 234 &VNET_NAME(bpf_optimize_writers), 0, 235 "Do not send packets until BPF program is set"); 236 237 static d_open_t bpfopen; 238 static d_read_t bpfread; 239 static d_write_t bpfwrite; 240 static d_ioctl_t bpfioctl; 241 static d_poll_t bpfpoll; 242 static d_kqfilter_t bpfkqfilter; 243 244 static struct cdevsw bpf_cdevsw = { 245 .d_version = D_VERSION, 246 .d_open = bpfopen, 247 .d_read = bpfread, 248 .d_write = bpfwrite, 249 .d_ioctl = bpfioctl, 250 .d_poll = bpfpoll, 251 .d_name = "bpf", 252 .d_kqfilter = bpfkqfilter, 253 }; 254 255 static struct filterops bpfread_filtops = { 256 .f_isfd = 1, 257 .f_detach = filt_bpfdetach, 258 .f_event = filt_bpfread, 259 }; 260 261 static struct filterops bpfwrite_filtops = { 262 .f_isfd = 1, 263 .f_detach = filt_bpfdetach, 264 .f_event = filt_bpfwrite, 265 }; 266 267 /* 268 * LOCKING MODEL USED BY BPF 269 * 270 * Locks: 271 * 1) global lock (BPF_LOCK). Sx, used to protect some global counters, 272 * every bpf_iflist changes, serializes ioctl access to bpf descriptors. 273 * 2) Descriptor lock. Mutex, used to protect BPF buffers and various 274 * structure fields used by bpf_*tap* code. 275 * 276 * Lock order: global lock, then descriptor lock. 277 * 278 * There are several possible consumers: 279 * 280 * 1. The kernel registers interface pointer with bpfattach(). 281 * Each call allocates new bpf_if structure, references ifnet pointer 282 * and links bpf_if into bpf_iflist chain. This is protected with global 283 * lock. 284 * 285 * 2. An userland application uses ioctl() call to bpf_d descriptor. 286 * All such call are serialized with global lock. BPF filters can be 287 * changed, but pointer to old filter will be freed using NET_EPOCH_CALL(). 288 * Thus it should be safe for bpf_tap/bpf_mtap* code to do access to 289 * filter pointers, even if change will happen during bpf_tap execution. 290 * Destroying of bpf_d descriptor also is doing using NET_EPOCH_CALL(). 291 * 292 * 3. An userland application can write packets into bpf_d descriptor. 293 * There we need to be sure, that ifnet won't disappear during bpfwrite(). 294 * 295 * 4. The kernel invokes bpf_tap/bpf_mtap* functions. The access to 296 * bif_dlist is protected with net_epoch_preempt section. So, it should 297 * be safe to make access to bpf_d descriptor inside the section. 298 * 299 * 5. The kernel invokes bpfdetach() on interface destroying. All lists 300 * are modified with global lock held and actual free() is done using 301 * NET_EPOCH_CALL(). 302 */ 303 304 static void 305 bpfif_free(epoch_context_t ctx) 306 { 307 struct bpf_if *bp; 308 309 bp = __containerof(ctx, struct bpf_if, epoch_ctx); 310 if_rele(bp->bif_ifp); 311 free(bp, M_BPF); 312 } 313 314 static void 315 bpfif_ref(struct bpf_if *bp) 316 { 317 318 refcount_acquire(&bp->bif_refcnt); 319 } 320 321 static void 322 bpfif_rele(struct bpf_if *bp) 323 { 324 325 if (!refcount_release(&bp->bif_refcnt)) 326 return; 327 NET_EPOCH_CALL(bpfif_free, &bp->epoch_ctx); 328 } 329 330 static void 331 bpfd_ref(struct bpf_d *d) 332 { 333 334 refcount_acquire(&d->bd_refcnt); 335 } 336 337 static void 338 bpfd_rele(struct bpf_d *d) 339 { 340 341 if (!refcount_release(&d->bd_refcnt)) 342 return; 343 NET_EPOCH_CALL(bpfd_free, &d->epoch_ctx); 344 } 345 346 static struct bpf_program_buffer* 347 bpf_program_buffer_alloc(size_t size, int flags) 348 { 349 350 return (malloc(sizeof(struct bpf_program_buffer) + size, 351 M_BPF, flags)); 352 } 353 354 static void 355 bpf_program_buffer_free(epoch_context_t ctx) 356 { 357 struct bpf_program_buffer *ptr; 358 359 ptr = __containerof(ctx, struct bpf_program_buffer, epoch_ctx); 360 #ifdef BPF_JITTER 361 if (ptr->func != NULL) 362 bpf_destroy_jit_filter(ptr->func); 363 #endif 364 free(ptr, M_BPF); 365 } 366 367 /* 368 * Wrapper functions for various buffering methods. If the set of buffer 369 * modes expands, we will probably want to introduce a switch data structure 370 * similar to protosw, et. 371 */ 372 static void 373 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 374 u_int len) 375 { 376 377 BPFD_LOCK_ASSERT(d); 378 379 switch (d->bd_bufmode) { 380 case BPF_BUFMODE_BUFFER: 381 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 382 383 case BPF_BUFMODE_ZBUF: 384 counter_u64_add(d->bd_zcopy, 1); 385 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 386 387 default: 388 panic("bpf_buf_append_bytes"); 389 } 390 } 391 392 static void 393 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 394 u_int len) 395 { 396 397 BPFD_LOCK_ASSERT(d); 398 399 switch (d->bd_bufmode) { 400 case BPF_BUFMODE_BUFFER: 401 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 402 403 case BPF_BUFMODE_ZBUF: 404 counter_u64_add(d->bd_zcopy, 1); 405 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 406 407 default: 408 panic("bpf_buf_append_mbuf"); 409 } 410 } 411 412 /* 413 * This function gets called when the free buffer is re-assigned. 414 */ 415 static void 416 bpf_buf_reclaimed(struct bpf_d *d) 417 { 418 419 BPFD_LOCK_ASSERT(d); 420 421 switch (d->bd_bufmode) { 422 case BPF_BUFMODE_BUFFER: 423 return; 424 425 case BPF_BUFMODE_ZBUF: 426 bpf_zerocopy_buf_reclaimed(d); 427 return; 428 429 default: 430 panic("bpf_buf_reclaimed"); 431 } 432 } 433 434 /* 435 * If the buffer mechanism has a way to decide that a held buffer can be made 436 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 437 * returned if the buffer can be discarded, (0) is returned if it cannot. 438 */ 439 static int 440 bpf_canfreebuf(struct bpf_d *d) 441 { 442 443 BPFD_LOCK_ASSERT(d); 444 445 switch (d->bd_bufmode) { 446 case BPF_BUFMODE_ZBUF: 447 return (bpf_zerocopy_canfreebuf(d)); 448 } 449 return (0); 450 } 451 452 /* 453 * Allow the buffer model to indicate that the current store buffer is 454 * immutable, regardless of the appearance of space. Return (1) if the 455 * buffer is writable, and (0) if not. 456 */ 457 static int 458 bpf_canwritebuf(struct bpf_d *d) 459 { 460 BPFD_LOCK_ASSERT(d); 461 462 switch (d->bd_bufmode) { 463 case BPF_BUFMODE_ZBUF: 464 return (bpf_zerocopy_canwritebuf(d)); 465 } 466 return (1); 467 } 468 469 /* 470 * Notify buffer model that an attempt to write to the store buffer has 471 * resulted in a dropped packet, in which case the buffer may be considered 472 * full. 473 */ 474 static void 475 bpf_buffull(struct bpf_d *d) 476 { 477 478 BPFD_LOCK_ASSERT(d); 479 480 switch (d->bd_bufmode) { 481 case BPF_BUFMODE_ZBUF: 482 bpf_zerocopy_buffull(d); 483 break; 484 } 485 } 486 487 /* 488 * Notify the buffer model that a buffer has moved into the hold position. 489 */ 490 void 491 bpf_bufheld(struct bpf_d *d) 492 { 493 494 BPFD_LOCK_ASSERT(d); 495 496 switch (d->bd_bufmode) { 497 case BPF_BUFMODE_ZBUF: 498 bpf_zerocopy_bufheld(d); 499 break; 500 } 501 } 502 503 static void 504 bpf_free(struct bpf_d *d) 505 { 506 507 switch (d->bd_bufmode) { 508 case BPF_BUFMODE_BUFFER: 509 return (bpf_buffer_free(d)); 510 511 case BPF_BUFMODE_ZBUF: 512 return (bpf_zerocopy_free(d)); 513 514 default: 515 panic("bpf_buf_free"); 516 } 517 } 518 519 static int 520 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 521 { 522 523 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 524 return (EOPNOTSUPP); 525 return (bpf_buffer_uiomove(d, buf, len, uio)); 526 } 527 528 static int 529 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 530 { 531 532 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 533 return (EOPNOTSUPP); 534 return (bpf_buffer_ioctl_sblen(d, i)); 535 } 536 537 static int 538 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 539 { 540 541 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 542 return (EOPNOTSUPP); 543 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 544 } 545 546 static int 547 bpf_ioctl_rotzbuf(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_rotzbuf(td, d, bz)); 553 } 554 555 static int 556 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 557 { 558 559 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 560 return (EOPNOTSUPP); 561 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 562 } 563 564 /* 565 * General BPF functions. 566 */ 567 static int 568 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 569 struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) 570 { 571 const struct ieee80211_bpf_params *p; 572 struct ether_header *eh; 573 struct mbuf *m; 574 int error; 575 int len; 576 int hlen; 577 int slen; 578 579 /* 580 * Build a sockaddr based on the data link layer type. 581 * We do this at this level because the ethernet header 582 * is copied directly into the data field of the sockaddr. 583 * In the case of SLIP, there is no header and the packet 584 * is forwarded as is. 585 * Also, we are careful to leave room at the front of the mbuf 586 * for the link level header. 587 */ 588 switch (linktype) { 589 case DLT_SLIP: 590 sockp->sa_family = AF_INET; 591 hlen = 0; 592 break; 593 594 case DLT_EN10MB: 595 sockp->sa_family = AF_UNSPEC; 596 /* XXX Would MAXLINKHDR be better? */ 597 hlen = ETHER_HDR_LEN; 598 break; 599 600 case DLT_FDDI: 601 sockp->sa_family = AF_IMPLINK; 602 hlen = 0; 603 break; 604 605 case DLT_RAW: 606 sockp->sa_family = AF_UNSPEC; 607 hlen = 0; 608 break; 609 610 case DLT_NULL: 611 /* 612 * null interface types require a 4 byte pseudo header which 613 * corresponds to the address family of the packet. 614 */ 615 sockp->sa_family = AF_UNSPEC; 616 hlen = 4; 617 break; 618 619 case DLT_ATM_RFC1483: 620 /* 621 * en atm driver requires 4-byte atm pseudo header. 622 * though it isn't standard, vpi:vci needs to be 623 * specified anyway. 624 */ 625 sockp->sa_family = AF_UNSPEC; 626 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 627 break; 628 629 case DLT_PPP: 630 sockp->sa_family = AF_UNSPEC; 631 hlen = 4; /* This should match PPP_HDRLEN */ 632 break; 633 634 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 635 sockp->sa_family = AF_IEEE80211; 636 hlen = 0; 637 break; 638 639 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 640 sockp->sa_family = AF_IEEE80211; 641 sockp->sa_len = 12; /* XXX != 0 */ 642 hlen = sizeof(struct ieee80211_bpf_params); 643 break; 644 645 default: 646 return (EIO); 647 } 648 649 len = uio->uio_resid; 650 if (len < hlen || len - hlen > ifp->if_mtu) 651 return (EMSGSIZE); 652 653 /* Allocate a mbuf for our write, since m_get2 fails if len >= to MJUMPAGESIZE, use m_getjcl for bigger buffers */ 654 m = m_get3(len, M_WAITOK, MT_DATA, M_PKTHDR); 655 if (m == NULL) 656 return (EIO); 657 m->m_pkthdr.len = m->m_len = len; 658 *mp = m; 659 660 error = uiomove(mtod(m, u_char *), len, uio); 661 if (error) 662 goto bad; 663 664 slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); 665 if (slen == 0) { 666 error = EPERM; 667 goto bad; 668 } 669 670 /* Check for multicast destination */ 671 switch (linktype) { 672 case DLT_EN10MB: 673 eh = mtod(m, struct ether_header *); 674 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 675 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 676 ETHER_ADDR_LEN) == 0) 677 m->m_flags |= M_BCAST; 678 else 679 m->m_flags |= M_MCAST; 680 } 681 if (d->bd_hdrcmplt == 0) { 682 memcpy(eh->ether_shost, IF_LLADDR(ifp), 683 sizeof(eh->ether_shost)); 684 } 685 break; 686 } 687 688 /* 689 * Make room for link header, and copy it to sockaddr 690 */ 691 if (hlen != 0) { 692 if (sockp->sa_family == AF_IEEE80211) { 693 /* 694 * Collect true length from the parameter header 695 * NB: sockp is known to be zero'd so if we do a 696 * short copy unspecified parameters will be 697 * zero. 698 * NB: packet may not be aligned after stripping 699 * bpf params 700 * XXX check ibp_vers 701 */ 702 p = mtod(m, const struct ieee80211_bpf_params *); 703 hlen = p->ibp_len; 704 if (hlen > sizeof(sockp->sa_data)) { 705 error = EINVAL; 706 goto bad; 707 } 708 } 709 bcopy(mtod(m, const void *), sockp->sa_data, hlen); 710 } 711 *hdrlen = hlen; 712 713 return (0); 714 bad: 715 m_freem(m); 716 return (error); 717 } 718 719 /* 720 * Attach descriptor to the bpf interface, i.e. make d listen on bp, 721 * then reset its buffers and counters with reset_d(). 722 */ 723 static void 724 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 725 { 726 int op_w; 727 728 BPF_LOCK_ASSERT(); 729 730 /* 731 * Save sysctl value to protect from sysctl change 732 * between reads 733 */ 734 op_w = V_bpf_optimize_writers || d->bd_writer; 735 736 if (d->bd_bif != NULL) 737 bpf_detachd_locked(d, false); 738 /* 739 * Point d at bp, and add d to the interface's list. 740 * Since there are many applications using BPF for 741 * sending raw packets only (dhcpd, cdpd are good examples) 742 * we can delay adding d to the list of active listeners until 743 * some filter is configured. 744 */ 745 746 BPFD_LOCK(d); 747 /* 748 * Hold reference to bpif while descriptor uses this interface. 749 */ 750 bpfif_ref(bp); 751 d->bd_bif = bp; 752 if (op_w != 0) { 753 /* Add to writers-only list */ 754 CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 755 /* 756 * We decrement bd_writer on every filter set operation. 757 * First BIOCSETF is done by pcap_open_live() to set up 758 * snap length. After that appliation usually sets its own 759 * filter. 760 */ 761 d->bd_writer = 2; 762 } else 763 CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 764 765 reset_d(d); 766 767 /* Trigger EVFILT_WRITE events. */ 768 bpf_wakeup(d); 769 770 BPFD_UNLOCK(d); 771 bpf_bpfd_cnt++; 772 773 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 774 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 775 776 if (op_w == 0) 777 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 778 } 779 780 /* 781 * Check if we need to upgrade our descriptor @d from write-only mode. 782 */ 783 static int 784 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 785 int flen) 786 { 787 int is_snap, need_upgrade; 788 789 /* 790 * Check if we've already upgraded or new filter is empty. 791 */ 792 if (d->bd_writer == 0 || fcode == NULL) 793 return (0); 794 795 need_upgrade = 0; 796 797 /* 798 * Check if cmd looks like snaplen setting from 799 * pcap_bpf.c:pcap_open_live(). 800 * Note we're not checking .k value here: 801 * while pcap_open_live() definitely sets to non-zero value, 802 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 803 * do not consider upgrading immediately 804 */ 805 if (cmd == BIOCSETF && flen == 1 && 806 fcode[0].code == (BPF_RET | BPF_K)) 807 is_snap = 1; 808 else 809 is_snap = 0; 810 811 if (is_snap == 0) { 812 /* 813 * We're setting first filter and it doesn't look like 814 * setting snaplen. We're probably using bpf directly. 815 * Upgrade immediately. 816 */ 817 need_upgrade = 1; 818 } else { 819 /* 820 * Do not require upgrade by first BIOCSETF 821 * (used to set snaplen) by pcap_open_live(). 822 */ 823 824 if (--d->bd_writer == 0) { 825 /* 826 * First snaplen filter has already 827 * been set. This is probably catch-all 828 * filter 829 */ 830 need_upgrade = 1; 831 } 832 } 833 834 CTR5(KTR_NET, 835 "%s: filter function set by pid %d, " 836 "bd_writer counter %d, snap %d upgrade %d", 837 __func__, d->bd_pid, d->bd_writer, 838 is_snap, need_upgrade); 839 840 return (need_upgrade); 841 } 842 843 /* 844 * Detach a file from its interface. 845 */ 846 static void 847 bpf_detachd(struct bpf_d *d) 848 { 849 BPF_LOCK(); 850 bpf_detachd_locked(d, false); 851 BPF_UNLOCK(); 852 } 853 854 static void 855 bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) 856 { 857 struct bpf_if *bp; 858 struct ifnet *ifp; 859 int error; 860 861 BPF_LOCK_ASSERT(); 862 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 863 864 /* Check if descriptor is attached */ 865 if ((bp = d->bd_bif) == NULL) 866 return; 867 868 BPFD_LOCK(d); 869 /* Remove d from the interface's descriptor list. */ 870 CK_LIST_REMOVE(d, bd_next); 871 /* Save bd_writer value */ 872 error = d->bd_writer; 873 ifp = bp->bif_ifp; 874 d->bd_bif = NULL; 875 if (detached_ifp) { 876 /* 877 * Notify descriptor as it's detached, so that any 878 * sleepers wake up and get ENXIO. 879 */ 880 bpf_wakeup(d); 881 } 882 BPFD_UNLOCK(d); 883 bpf_bpfd_cnt--; 884 885 /* Call event handler iff d is attached */ 886 if (error == 0) 887 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 888 889 /* 890 * Check if this descriptor had requested promiscuous mode. 891 * If so and ifnet is not detached, turn it off. 892 */ 893 if (d->bd_promisc && !detached_ifp) { 894 d->bd_promisc = 0; 895 CURVNET_SET(ifp->if_vnet); 896 error = ifpromisc(ifp, 0); 897 CURVNET_RESTORE(); 898 if (error != 0 && error != ENXIO) { 899 /* 900 * ENXIO can happen if a pccard is unplugged 901 * Something is really wrong if we were able to put 902 * the driver into promiscuous mode, but can't 903 * take it out. 904 */ 905 if_printf(bp->bif_ifp, 906 "bpf_detach: ifpromisc failed (%d)\n", error); 907 } 908 } 909 bpfif_rele(bp); 910 } 911 912 /* 913 * Close the descriptor by detaching it from its interface, 914 * deallocating its buffers, and marking it free. 915 */ 916 static void 917 bpf_dtor(void *data) 918 { 919 struct bpf_d *d = data; 920 921 BPFD_LOCK(d); 922 if (d->bd_state == BPF_WAITING) 923 callout_stop(&d->bd_callout); 924 d->bd_state = BPF_IDLE; 925 BPFD_UNLOCK(d); 926 funsetown(&d->bd_sigio); 927 bpf_detachd(d); 928 #ifdef MAC 929 mac_bpfdesc_destroy(d); 930 #endif /* MAC */ 931 seldrain(&d->bd_sel); 932 knlist_destroy(&d->bd_sel.si_note); 933 callout_drain(&d->bd_callout); 934 bpfd_rele(d); 935 } 936 937 /* 938 * Open ethernet device. Returns ENXIO for illegal minor device number, 939 * EBUSY if file is open by another process. 940 */ 941 /* ARGSUSED */ 942 static int 943 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 944 { 945 struct bpf_d *d; 946 int error; 947 948 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 949 error = devfs_set_cdevpriv(d, bpf_dtor); 950 if (error != 0) { 951 free(d, M_BPF); 952 return (error); 953 } 954 955 /* Setup counters */ 956 d->bd_rcount = counter_u64_alloc(M_WAITOK); 957 d->bd_dcount = counter_u64_alloc(M_WAITOK); 958 d->bd_fcount = counter_u64_alloc(M_WAITOK); 959 d->bd_wcount = counter_u64_alloc(M_WAITOK); 960 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 961 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 962 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 963 964 /* 965 * For historical reasons, perform a one-time initialization call to 966 * the buffer routines, even though we're not yet committed to a 967 * particular buffer method. 968 */ 969 bpf_buffer_init(d); 970 if ((flags & FREAD) == 0) 971 d->bd_writer = 2; 972 d->bd_hbuf_in_use = 0; 973 d->bd_bufmode = BPF_BUFMODE_BUFFER; 974 d->bd_sig = SIGIO; 975 d->bd_direction = BPF_D_INOUT; 976 refcount_init(&d->bd_refcnt, 1); 977 BPF_PID_REFRESH(d, td); 978 #ifdef MAC 979 mac_bpfdesc_init(d); 980 mac_bpfdesc_create(td->td_ucred, d); 981 #endif 982 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 983 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 984 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 985 986 /* Disable VLAN pcp tagging. */ 987 d->bd_pcp = 0; 988 989 return (0); 990 } 991 992 /* 993 * bpfread - read next chunk of packets from buffers 994 */ 995 static int 996 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 997 { 998 struct bpf_d *d; 999 int error; 1000 int non_block; 1001 int timed_out; 1002 1003 error = devfs_get_cdevpriv((void **)&d); 1004 if (error != 0) 1005 return (error); 1006 1007 /* 1008 * Restrict application to use a buffer the same size as 1009 * as kernel buffers. 1010 */ 1011 if (uio->uio_resid != d->bd_bufsize) 1012 return (EINVAL); 1013 1014 non_block = ((ioflag & O_NONBLOCK) != 0); 1015 1016 BPFD_LOCK(d); 1017 BPF_PID_REFRESH_CUR(d); 1018 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 1019 BPFD_UNLOCK(d); 1020 return (EOPNOTSUPP); 1021 } 1022 if (d->bd_state == BPF_WAITING) 1023 callout_stop(&d->bd_callout); 1024 timed_out = (d->bd_state == BPF_TIMED_OUT); 1025 d->bd_state = BPF_IDLE; 1026 while (d->bd_hbuf_in_use) { 1027 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1028 PRINET|PCATCH, "bd_hbuf", 0); 1029 if (error != 0) { 1030 BPFD_UNLOCK(d); 1031 return (error); 1032 } 1033 } 1034 /* 1035 * If the hold buffer is empty, then do a timed sleep, which 1036 * ends when the timeout expires or when enough packets 1037 * have arrived to fill the store buffer. 1038 */ 1039 while (d->bd_hbuf == NULL) { 1040 if (d->bd_slen != 0) { 1041 /* 1042 * A packet(s) either arrived since the previous 1043 * read or arrived while we were asleep. 1044 */ 1045 if (d->bd_immediate || non_block || timed_out) { 1046 /* 1047 * Rotate the buffers and return what's here 1048 * if we are in immediate mode, non-blocking 1049 * flag is set, or this descriptor timed out. 1050 */ 1051 ROTATE_BUFFERS(d); 1052 break; 1053 } 1054 } 1055 1056 /* 1057 * No data is available, check to see if the bpf device 1058 * is still pointed at a real interface. If not, return 1059 * ENXIO so that the userland process knows to rebind 1060 * it before using it again. 1061 */ 1062 if (d->bd_bif == NULL) { 1063 BPFD_UNLOCK(d); 1064 return (ENXIO); 1065 } 1066 1067 if (non_block) { 1068 BPFD_UNLOCK(d); 1069 return (EWOULDBLOCK); 1070 } 1071 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 1072 "bpf", d->bd_rtout); 1073 if (error == EINTR || error == ERESTART) { 1074 BPFD_UNLOCK(d); 1075 return (error); 1076 } 1077 if (error == EWOULDBLOCK) { 1078 /* 1079 * On a timeout, return what's in the buffer, 1080 * which may be nothing. If there is something 1081 * in the store buffer, we can rotate the buffers. 1082 */ 1083 if (d->bd_hbuf) 1084 /* 1085 * We filled up the buffer in between 1086 * getting the timeout and arriving 1087 * here, so we don't need to rotate. 1088 */ 1089 break; 1090 1091 if (d->bd_slen == 0) { 1092 BPFD_UNLOCK(d); 1093 return (0); 1094 } 1095 ROTATE_BUFFERS(d); 1096 break; 1097 } 1098 } 1099 /* 1100 * At this point, we know we have something in the hold slot. 1101 */ 1102 d->bd_hbuf_in_use = 1; 1103 BPFD_UNLOCK(d); 1104 1105 /* 1106 * Move data from hold buffer into user space. 1107 * We know the entire buffer is transferred since 1108 * we checked above that the read buffer is bpf_bufsize bytes. 1109 * 1110 * We do not have to worry about simultaneous reads because 1111 * we waited for sole access to the hold buffer above. 1112 */ 1113 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1114 1115 BPFD_LOCK(d); 1116 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1117 d->bd_fbuf = d->bd_hbuf; 1118 d->bd_hbuf = NULL; 1119 d->bd_hlen = 0; 1120 bpf_buf_reclaimed(d); 1121 d->bd_hbuf_in_use = 0; 1122 wakeup(&d->bd_hbuf_in_use); 1123 BPFD_UNLOCK(d); 1124 1125 return (error); 1126 } 1127 1128 /* 1129 * If there are processes sleeping on this descriptor, wake them up. 1130 */ 1131 static __inline void 1132 bpf_wakeup(struct bpf_d *d) 1133 { 1134 1135 BPFD_LOCK_ASSERT(d); 1136 if (d->bd_state == BPF_WAITING) { 1137 callout_stop(&d->bd_callout); 1138 d->bd_state = BPF_IDLE; 1139 } 1140 wakeup(d); 1141 if (d->bd_async && d->bd_sig && d->bd_sigio) 1142 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1143 1144 selwakeuppri(&d->bd_sel, PRINET); 1145 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1146 } 1147 1148 static void 1149 bpf_timed_out(void *arg) 1150 { 1151 struct bpf_d *d = (struct bpf_d *)arg; 1152 1153 BPFD_LOCK_ASSERT(d); 1154 1155 if (callout_pending(&d->bd_callout) || 1156 !callout_active(&d->bd_callout)) 1157 return; 1158 if (d->bd_state == BPF_WAITING) { 1159 d->bd_state = BPF_TIMED_OUT; 1160 if (d->bd_slen != 0) 1161 bpf_wakeup(d); 1162 } 1163 } 1164 1165 static int 1166 bpf_ready(struct bpf_d *d) 1167 { 1168 1169 BPFD_LOCK_ASSERT(d); 1170 1171 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1172 return (1); 1173 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1174 d->bd_slen != 0) 1175 return (1); 1176 return (0); 1177 } 1178 1179 static int 1180 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1181 { 1182 struct route ro; 1183 struct sockaddr dst; 1184 struct epoch_tracker et; 1185 struct bpf_if *bp; 1186 struct bpf_d *d; 1187 struct ifnet *ifp; 1188 struct mbuf *m, *mc; 1189 int error, hlen; 1190 1191 error = devfs_get_cdevpriv((void **)&d); 1192 if (error != 0) 1193 return (error); 1194 1195 NET_EPOCH_ENTER(et); 1196 BPFD_LOCK(d); 1197 BPF_PID_REFRESH_CUR(d); 1198 counter_u64_add(d->bd_wcount, 1); 1199 if ((bp = d->bd_bif) == NULL) { 1200 error = ENXIO; 1201 goto out_locked; 1202 } 1203 1204 ifp = bp->bif_ifp; 1205 if ((ifp->if_flags & IFF_UP) == 0) { 1206 error = ENETDOWN; 1207 goto out_locked; 1208 } 1209 1210 if (uio->uio_resid == 0) 1211 goto out_locked; 1212 1213 bzero(&dst, sizeof(dst)); 1214 m = NULL; 1215 hlen = 0; 1216 1217 /* 1218 * Take extra reference, unlock d and exit from epoch section, 1219 * since bpf_movein() can sleep. 1220 */ 1221 bpfd_ref(d); 1222 NET_EPOCH_EXIT(et); 1223 BPFD_UNLOCK(d); 1224 1225 error = bpf_movein(uio, (int)bp->bif_dlt, ifp, 1226 &m, &dst, &hlen, d); 1227 1228 if (error != 0) { 1229 counter_u64_add(d->bd_wdcount, 1); 1230 bpfd_rele(d); 1231 return (error); 1232 } 1233 1234 BPFD_LOCK(d); 1235 /* 1236 * Check that descriptor is still attached to the interface. 1237 * This can happen on bpfdetach(). To avoid access to detached 1238 * ifnet, free mbuf and return ENXIO. 1239 */ 1240 if (d->bd_bif == NULL) { 1241 counter_u64_add(d->bd_wdcount, 1); 1242 BPFD_UNLOCK(d); 1243 bpfd_rele(d); 1244 m_freem(m); 1245 return (ENXIO); 1246 } 1247 counter_u64_add(d->bd_wfcount, 1); 1248 if (d->bd_hdrcmplt) 1249 dst.sa_family = pseudo_AF_HDRCMPLT; 1250 1251 if (d->bd_feedback) { 1252 mc = m_dup(m, M_NOWAIT); 1253 if (mc != NULL) 1254 mc->m_pkthdr.rcvif = ifp; 1255 /* Set M_PROMISC for outgoing packets to be discarded. */ 1256 if (d->bd_direction == BPF_D_INOUT) 1257 m->m_flags |= M_PROMISC; 1258 } else 1259 mc = NULL; 1260 1261 m->m_pkthdr.len -= hlen; 1262 m->m_len -= hlen; 1263 m->m_data += hlen; /* XXX */ 1264 1265 CURVNET_SET(ifp->if_vnet); 1266 #ifdef MAC 1267 mac_bpfdesc_create_mbuf(d, m); 1268 if (mc != NULL) 1269 mac_bpfdesc_create_mbuf(d, mc); 1270 #endif 1271 1272 bzero(&ro, sizeof(ro)); 1273 if (hlen != 0) { 1274 ro.ro_prepend = (u_char *)&dst.sa_data; 1275 ro.ro_plen = hlen; 1276 ro.ro_flags = RT_HAS_HEADER; 1277 } 1278 1279 if (d->bd_pcp != 0) 1280 vlan_set_pcp(m, d->bd_pcp); 1281 1282 /* Avoid possible recursion on BPFD_LOCK(). */ 1283 NET_EPOCH_ENTER(et); 1284 BPFD_UNLOCK(d); 1285 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1286 if (error) 1287 counter_u64_add(d->bd_wdcount, 1); 1288 1289 if (mc != NULL) { 1290 if (error == 0) 1291 (*ifp->if_input)(ifp, mc); 1292 else 1293 m_freem(mc); 1294 } 1295 NET_EPOCH_EXIT(et); 1296 CURVNET_RESTORE(); 1297 bpfd_rele(d); 1298 return (error); 1299 1300 out_locked: 1301 counter_u64_add(d->bd_wdcount, 1); 1302 NET_EPOCH_EXIT(et); 1303 BPFD_UNLOCK(d); 1304 return (error); 1305 } 1306 1307 /* 1308 * Reset a descriptor by flushing its packet buffer and clearing the receive 1309 * and drop counts. This is doable for kernel-only buffers, but with 1310 * zero-copy buffers, we can't write to (or rotate) buffers that are 1311 * currently owned by userspace. It would be nice if we could encapsulate 1312 * this logic in the buffer code rather than here. 1313 */ 1314 static void 1315 reset_d(struct bpf_d *d) 1316 { 1317 1318 BPFD_LOCK_ASSERT(d); 1319 1320 while (d->bd_hbuf_in_use) 1321 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1322 "bd_hbuf", 0); 1323 if ((d->bd_hbuf != NULL) && 1324 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1325 /* Free the hold buffer. */ 1326 d->bd_fbuf = d->bd_hbuf; 1327 d->bd_hbuf = NULL; 1328 d->bd_hlen = 0; 1329 bpf_buf_reclaimed(d); 1330 } 1331 if (bpf_canwritebuf(d)) 1332 d->bd_slen = 0; 1333 counter_u64_zero(d->bd_rcount); 1334 counter_u64_zero(d->bd_dcount); 1335 counter_u64_zero(d->bd_fcount); 1336 counter_u64_zero(d->bd_wcount); 1337 counter_u64_zero(d->bd_wfcount); 1338 counter_u64_zero(d->bd_wdcount); 1339 counter_u64_zero(d->bd_zcopy); 1340 } 1341 1342 /* 1343 * FIONREAD Check for read packet available. 1344 * BIOCGBLEN Get buffer len [for read()]. 1345 * BIOCSETF Set read filter. 1346 * BIOCSETFNR Set read filter without resetting descriptor. 1347 * BIOCSETWF Set write filter. 1348 * BIOCFLUSH Flush read packet buffer. 1349 * BIOCPROMISC Put interface into promiscuous mode. 1350 * BIOCGDLT Get link layer type. 1351 * BIOCGETIF Get interface name. 1352 * BIOCSETIF Set interface. 1353 * BIOCSRTIMEOUT Set read timeout. 1354 * BIOCGRTIMEOUT Get read timeout. 1355 * BIOCGSTATS Get packet stats. 1356 * BIOCIMMEDIATE Set immediate mode. 1357 * BIOCVERSION Get filter language version. 1358 * BIOCGHDRCMPLT Get "header already complete" flag 1359 * BIOCSHDRCMPLT Set "header already complete" flag 1360 * BIOCGDIRECTION Get packet direction flag 1361 * BIOCSDIRECTION Set packet direction flag 1362 * BIOCGTSTAMP Get time stamp format and resolution. 1363 * BIOCSTSTAMP Set time stamp format and resolution. 1364 * BIOCLOCK Set "locked" flag 1365 * BIOCFEEDBACK Set packet feedback mode. 1366 * BIOCSETZBUF Set current zero-copy buffer locations. 1367 * BIOCGETZMAX Get maximum zero-copy buffer size. 1368 * BIOCROTZBUF Force rotation of zero-copy buffer 1369 * BIOCSETBUFMODE Set buffer mode. 1370 * BIOCGETBUFMODE Get current buffer mode. 1371 * BIOCSETVLANPCP Set VLAN PCP tag. 1372 */ 1373 /* ARGSUSED */ 1374 static int 1375 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1376 struct thread *td) 1377 { 1378 struct bpf_d *d; 1379 int error; 1380 1381 error = devfs_get_cdevpriv((void **)&d); 1382 if (error != 0) 1383 return (error); 1384 1385 /* 1386 * Refresh PID associated with this descriptor. 1387 */ 1388 BPFD_LOCK(d); 1389 BPF_PID_REFRESH(d, td); 1390 if (d->bd_state == BPF_WAITING) 1391 callout_stop(&d->bd_callout); 1392 d->bd_state = BPF_IDLE; 1393 BPFD_UNLOCK(d); 1394 1395 if (d->bd_locked == 1) { 1396 switch (cmd) { 1397 case BIOCGBLEN: 1398 case BIOCFLUSH: 1399 case BIOCGDLT: 1400 case BIOCGDLTLIST: 1401 #ifdef COMPAT_FREEBSD32 1402 case BIOCGDLTLIST32: 1403 #endif 1404 case BIOCGETIF: 1405 case BIOCGRTIMEOUT: 1406 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1407 case BIOCGRTIMEOUT32: 1408 #endif 1409 case BIOCGSTATS: 1410 case BIOCVERSION: 1411 case BIOCGRSIG: 1412 case BIOCGHDRCMPLT: 1413 case BIOCSTSTAMP: 1414 case BIOCFEEDBACK: 1415 case FIONREAD: 1416 case BIOCLOCK: 1417 case BIOCSRTIMEOUT: 1418 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1419 case BIOCSRTIMEOUT32: 1420 #endif 1421 case BIOCIMMEDIATE: 1422 case TIOCGPGRP: 1423 case BIOCROTZBUF: 1424 break; 1425 default: 1426 return (EPERM); 1427 } 1428 } 1429 #ifdef COMPAT_FREEBSD32 1430 /* 1431 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1432 * that it will get 32-bit packet headers. 1433 */ 1434 switch (cmd) { 1435 case BIOCSETF32: 1436 case BIOCSETFNR32: 1437 case BIOCSETWF32: 1438 case BIOCGDLTLIST32: 1439 case BIOCGRTIMEOUT32: 1440 case BIOCSRTIMEOUT32: 1441 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1442 BPFD_LOCK(d); 1443 d->bd_compat32 = 1; 1444 BPFD_UNLOCK(d); 1445 } 1446 } 1447 #endif 1448 1449 CURVNET_SET(TD_TO_VNET(td)); 1450 switch (cmd) { 1451 default: 1452 error = EINVAL; 1453 break; 1454 1455 /* 1456 * Check for read packet available. 1457 */ 1458 case FIONREAD: 1459 { 1460 int n; 1461 1462 BPFD_LOCK(d); 1463 n = d->bd_slen; 1464 while (d->bd_hbuf_in_use) 1465 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1466 PRINET, "bd_hbuf", 0); 1467 if (d->bd_hbuf) 1468 n += d->bd_hlen; 1469 BPFD_UNLOCK(d); 1470 1471 *(int *)addr = n; 1472 break; 1473 } 1474 1475 /* 1476 * Get buffer len [for read()]. 1477 */ 1478 case BIOCGBLEN: 1479 BPFD_LOCK(d); 1480 *(u_int *)addr = d->bd_bufsize; 1481 BPFD_UNLOCK(d); 1482 break; 1483 1484 /* 1485 * Set buffer length. 1486 */ 1487 case BIOCSBLEN: 1488 error = bpf_ioctl_sblen(d, (u_int *)addr); 1489 break; 1490 1491 /* 1492 * Set link layer read filter. 1493 */ 1494 case BIOCSETF: 1495 case BIOCSETFNR: 1496 case BIOCSETWF: 1497 #ifdef COMPAT_FREEBSD32 1498 case BIOCSETF32: 1499 case BIOCSETFNR32: 1500 case BIOCSETWF32: 1501 #endif 1502 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1503 break; 1504 1505 /* 1506 * Flush read packet buffer. 1507 */ 1508 case BIOCFLUSH: 1509 BPFD_LOCK(d); 1510 reset_d(d); 1511 BPFD_UNLOCK(d); 1512 break; 1513 1514 /* 1515 * Put interface into promiscuous mode. 1516 */ 1517 case BIOCPROMISC: 1518 BPF_LOCK(); 1519 if (d->bd_bif == NULL) { 1520 /* 1521 * No interface attached yet. 1522 */ 1523 error = EINVAL; 1524 } else if (d->bd_promisc == 0) { 1525 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1526 if (error == 0) 1527 d->bd_promisc = 1; 1528 } 1529 BPF_UNLOCK(); 1530 break; 1531 1532 /* 1533 * Get current data link type. 1534 */ 1535 case BIOCGDLT: 1536 BPF_LOCK(); 1537 if (d->bd_bif == NULL) 1538 error = EINVAL; 1539 else 1540 *(u_int *)addr = d->bd_bif->bif_dlt; 1541 BPF_UNLOCK(); 1542 break; 1543 1544 /* 1545 * Get a list of supported data link types. 1546 */ 1547 #ifdef COMPAT_FREEBSD32 1548 case BIOCGDLTLIST32: 1549 { 1550 struct bpf_dltlist32 *list32; 1551 struct bpf_dltlist dltlist; 1552 1553 list32 = (struct bpf_dltlist32 *)addr; 1554 dltlist.bfl_len = list32->bfl_len; 1555 dltlist.bfl_list = PTRIN(list32->bfl_list); 1556 BPF_LOCK(); 1557 if (d->bd_bif == NULL) 1558 error = EINVAL; 1559 else { 1560 error = bpf_getdltlist(d, &dltlist); 1561 if (error == 0) 1562 list32->bfl_len = dltlist.bfl_len; 1563 } 1564 BPF_UNLOCK(); 1565 break; 1566 } 1567 #endif 1568 1569 case BIOCGDLTLIST: 1570 BPF_LOCK(); 1571 if (d->bd_bif == NULL) 1572 error = EINVAL; 1573 else 1574 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1575 BPF_UNLOCK(); 1576 break; 1577 1578 /* 1579 * Set data link type. 1580 */ 1581 case BIOCSDLT: 1582 BPF_LOCK(); 1583 if (d->bd_bif == NULL) 1584 error = EINVAL; 1585 else 1586 error = bpf_setdlt(d, *(u_int *)addr); 1587 BPF_UNLOCK(); 1588 break; 1589 1590 /* 1591 * Get interface name. 1592 */ 1593 case BIOCGETIF: 1594 BPF_LOCK(); 1595 if (d->bd_bif == NULL) 1596 error = EINVAL; 1597 else { 1598 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1599 struct ifreq *const ifr = (struct ifreq *)addr; 1600 1601 strlcpy(ifr->ifr_name, ifp->if_xname, 1602 sizeof(ifr->ifr_name)); 1603 } 1604 BPF_UNLOCK(); 1605 break; 1606 1607 /* 1608 * Set interface. 1609 */ 1610 case BIOCSETIF: 1611 { 1612 int alloc_buf, size; 1613 1614 /* 1615 * Behavior here depends on the buffering model. If 1616 * we're using kernel memory buffers, then we can 1617 * allocate them here. If we're using zero-copy, 1618 * then the user process must have registered buffers 1619 * by the time we get here. 1620 */ 1621 alloc_buf = 0; 1622 BPFD_LOCK(d); 1623 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1624 d->bd_sbuf == NULL) 1625 alloc_buf = 1; 1626 BPFD_UNLOCK(d); 1627 if (alloc_buf) { 1628 size = d->bd_bufsize; 1629 error = bpf_buffer_ioctl_sblen(d, &size); 1630 if (error != 0) 1631 break; 1632 } 1633 BPF_LOCK(); 1634 error = bpf_setif(d, (struct ifreq *)addr); 1635 BPF_UNLOCK(); 1636 break; 1637 } 1638 1639 /* 1640 * Set read timeout. 1641 */ 1642 case BIOCSRTIMEOUT: 1643 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1644 case BIOCSRTIMEOUT32: 1645 #endif 1646 { 1647 struct timeval *tv = (struct timeval *)addr; 1648 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1649 struct timeval32 *tv32; 1650 struct timeval tv64; 1651 1652 if (cmd == BIOCSRTIMEOUT32) { 1653 tv32 = (struct timeval32 *)addr; 1654 tv = &tv64; 1655 tv->tv_sec = tv32->tv_sec; 1656 tv->tv_usec = tv32->tv_usec; 1657 } else 1658 #endif 1659 tv = (struct timeval *)addr; 1660 1661 /* 1662 * Subtract 1 tick from tvtohz() since this isn't 1663 * a one-shot timer. 1664 */ 1665 if ((error = itimerfix(tv)) == 0) 1666 d->bd_rtout = tvtohz(tv) - 1; 1667 break; 1668 } 1669 1670 /* 1671 * Get read timeout. 1672 */ 1673 case BIOCGRTIMEOUT: 1674 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1675 case BIOCGRTIMEOUT32: 1676 #endif 1677 { 1678 struct timeval *tv; 1679 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1680 struct timeval32 *tv32; 1681 struct timeval tv64; 1682 1683 if (cmd == BIOCGRTIMEOUT32) 1684 tv = &tv64; 1685 else 1686 #endif 1687 tv = (struct timeval *)addr; 1688 1689 tv->tv_sec = d->bd_rtout / hz; 1690 tv->tv_usec = (d->bd_rtout % hz) * tick; 1691 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1692 if (cmd == BIOCGRTIMEOUT32) { 1693 tv32 = (struct timeval32 *)addr; 1694 tv32->tv_sec = tv->tv_sec; 1695 tv32->tv_usec = tv->tv_usec; 1696 } 1697 #endif 1698 1699 break; 1700 } 1701 1702 /* 1703 * Get packet stats. 1704 */ 1705 case BIOCGSTATS: 1706 { 1707 struct bpf_stat *bs = (struct bpf_stat *)addr; 1708 1709 /* XXXCSJP overflow */ 1710 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1711 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1712 break; 1713 } 1714 1715 /* 1716 * Set immediate mode. 1717 */ 1718 case BIOCIMMEDIATE: 1719 BPFD_LOCK(d); 1720 d->bd_immediate = *(u_int *)addr; 1721 BPFD_UNLOCK(d); 1722 break; 1723 1724 case BIOCVERSION: 1725 { 1726 struct bpf_version *bv = (struct bpf_version *)addr; 1727 1728 bv->bv_major = BPF_MAJOR_VERSION; 1729 bv->bv_minor = BPF_MINOR_VERSION; 1730 break; 1731 } 1732 1733 /* 1734 * Get "header already complete" flag 1735 */ 1736 case BIOCGHDRCMPLT: 1737 BPFD_LOCK(d); 1738 *(u_int *)addr = d->bd_hdrcmplt; 1739 BPFD_UNLOCK(d); 1740 break; 1741 1742 /* 1743 * Set "header already complete" flag 1744 */ 1745 case BIOCSHDRCMPLT: 1746 BPFD_LOCK(d); 1747 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1748 BPFD_UNLOCK(d); 1749 break; 1750 1751 /* 1752 * Get packet direction flag 1753 */ 1754 case BIOCGDIRECTION: 1755 BPFD_LOCK(d); 1756 *(u_int *)addr = d->bd_direction; 1757 BPFD_UNLOCK(d); 1758 break; 1759 1760 /* 1761 * Set packet direction flag 1762 */ 1763 case BIOCSDIRECTION: 1764 { 1765 u_int direction; 1766 1767 direction = *(u_int *)addr; 1768 switch (direction) { 1769 case BPF_D_IN: 1770 case BPF_D_INOUT: 1771 case BPF_D_OUT: 1772 BPFD_LOCK(d); 1773 d->bd_direction = direction; 1774 BPFD_UNLOCK(d); 1775 break; 1776 default: 1777 error = EINVAL; 1778 } 1779 } 1780 break; 1781 1782 /* 1783 * Get packet timestamp format and resolution. 1784 */ 1785 case BIOCGTSTAMP: 1786 BPFD_LOCK(d); 1787 *(u_int *)addr = d->bd_tstamp; 1788 BPFD_UNLOCK(d); 1789 break; 1790 1791 /* 1792 * Set packet timestamp format and resolution. 1793 */ 1794 case BIOCSTSTAMP: 1795 { 1796 u_int func; 1797 1798 func = *(u_int *)addr; 1799 if (BPF_T_VALID(func)) 1800 d->bd_tstamp = func; 1801 else 1802 error = EINVAL; 1803 } 1804 break; 1805 1806 case BIOCFEEDBACK: 1807 BPFD_LOCK(d); 1808 d->bd_feedback = *(u_int *)addr; 1809 BPFD_UNLOCK(d); 1810 break; 1811 1812 case BIOCLOCK: 1813 BPFD_LOCK(d); 1814 d->bd_locked = 1; 1815 BPFD_UNLOCK(d); 1816 break; 1817 1818 case FIONBIO: /* Non-blocking I/O */ 1819 break; 1820 1821 case FIOASYNC: /* Send signal on receive packets */ 1822 BPFD_LOCK(d); 1823 d->bd_async = *(int *)addr; 1824 BPFD_UNLOCK(d); 1825 break; 1826 1827 case FIOSETOWN: 1828 /* 1829 * XXX: Add some sort of locking here? 1830 * fsetown() can sleep. 1831 */ 1832 error = fsetown(*(int *)addr, &d->bd_sigio); 1833 break; 1834 1835 case FIOGETOWN: 1836 BPFD_LOCK(d); 1837 *(int *)addr = fgetown(&d->bd_sigio); 1838 BPFD_UNLOCK(d); 1839 break; 1840 1841 /* This is deprecated, FIOSETOWN should be used instead. */ 1842 case TIOCSPGRP: 1843 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1844 break; 1845 1846 /* This is deprecated, FIOGETOWN should be used instead. */ 1847 case TIOCGPGRP: 1848 *(int *)addr = -fgetown(&d->bd_sigio); 1849 break; 1850 1851 case BIOCSRSIG: /* Set receive signal */ 1852 { 1853 u_int sig; 1854 1855 sig = *(u_int *)addr; 1856 1857 if (sig >= NSIG) 1858 error = EINVAL; 1859 else { 1860 BPFD_LOCK(d); 1861 d->bd_sig = sig; 1862 BPFD_UNLOCK(d); 1863 } 1864 break; 1865 } 1866 case BIOCGRSIG: 1867 BPFD_LOCK(d); 1868 *(u_int *)addr = d->bd_sig; 1869 BPFD_UNLOCK(d); 1870 break; 1871 1872 case BIOCGETBUFMODE: 1873 BPFD_LOCK(d); 1874 *(u_int *)addr = d->bd_bufmode; 1875 BPFD_UNLOCK(d); 1876 break; 1877 1878 case BIOCSETBUFMODE: 1879 /* 1880 * Allow the buffering mode to be changed as long as we 1881 * haven't yet committed to a particular mode. Our 1882 * definition of commitment, for now, is whether or not a 1883 * buffer has been allocated or an interface attached, since 1884 * that's the point where things get tricky. 1885 */ 1886 switch (*(u_int *)addr) { 1887 case BPF_BUFMODE_BUFFER: 1888 break; 1889 1890 case BPF_BUFMODE_ZBUF: 1891 if (bpf_zerocopy_enable) 1892 break; 1893 /* FALLSTHROUGH */ 1894 1895 default: 1896 CURVNET_RESTORE(); 1897 return (EINVAL); 1898 } 1899 1900 BPFD_LOCK(d); 1901 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1902 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1903 BPFD_UNLOCK(d); 1904 CURVNET_RESTORE(); 1905 return (EBUSY); 1906 } 1907 d->bd_bufmode = *(u_int *)addr; 1908 BPFD_UNLOCK(d); 1909 break; 1910 1911 case BIOCGETZMAX: 1912 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1913 break; 1914 1915 case BIOCSETZBUF: 1916 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1917 break; 1918 1919 case BIOCROTZBUF: 1920 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1921 break; 1922 1923 case BIOCSETVLANPCP: 1924 { 1925 u_int pcp; 1926 1927 pcp = *(u_int *)addr; 1928 if (pcp > BPF_PRIO_MAX || pcp < 0) { 1929 error = EINVAL; 1930 break; 1931 } 1932 d->bd_pcp = pcp; 1933 break; 1934 } 1935 } 1936 CURVNET_RESTORE(); 1937 return (error); 1938 } 1939 1940 /* 1941 * Set d's packet filter program to fp. If this file already has a filter, 1942 * free it and replace it. Returns EINVAL for bogus requests. 1943 * 1944 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1945 * calls. 1946 */ 1947 static int 1948 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1949 { 1950 #ifdef COMPAT_FREEBSD32 1951 struct bpf_program fp_swab; 1952 struct bpf_program32 *fp32; 1953 #endif 1954 struct bpf_program_buffer *fcode; 1955 struct bpf_insn *filter; 1956 #ifdef BPF_JITTER 1957 bpf_jit_filter *jfunc; 1958 #endif 1959 size_t size; 1960 u_int flen; 1961 bool track_event; 1962 1963 #ifdef COMPAT_FREEBSD32 1964 switch (cmd) { 1965 case BIOCSETF32: 1966 case BIOCSETWF32: 1967 case BIOCSETFNR32: 1968 fp32 = (struct bpf_program32 *)fp; 1969 fp_swab.bf_len = fp32->bf_len; 1970 fp_swab.bf_insns = 1971 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1972 fp = &fp_swab; 1973 switch (cmd) { 1974 case BIOCSETF32: 1975 cmd = BIOCSETF; 1976 break; 1977 case BIOCSETWF32: 1978 cmd = BIOCSETWF; 1979 break; 1980 } 1981 break; 1982 } 1983 #endif 1984 1985 filter = NULL; 1986 #ifdef BPF_JITTER 1987 jfunc = NULL; 1988 #endif 1989 /* 1990 * Check new filter validness before acquiring any locks. 1991 * Allocate memory for new filter, if needed. 1992 */ 1993 flen = fp->bf_len; 1994 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1995 return (EINVAL); 1996 size = flen * sizeof(*fp->bf_insns); 1997 if (size > 0) { 1998 /* We're setting up new filter. Copy and check actual data. */ 1999 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 2000 filter = (struct bpf_insn *)fcode->buffer; 2001 if (copyin(fp->bf_insns, filter, size) != 0 || 2002 !bpf_validate(filter, flen)) { 2003 free(fcode, M_BPF); 2004 return (EINVAL); 2005 } 2006 #ifdef BPF_JITTER 2007 if (cmd != BIOCSETWF) { 2008 /* 2009 * Filter is copied inside fcode and is 2010 * perfectly valid. 2011 */ 2012 jfunc = bpf_jitter(filter, flen); 2013 } 2014 #endif 2015 } 2016 2017 track_event = false; 2018 fcode = NULL; 2019 2020 BPF_LOCK(); 2021 BPFD_LOCK(d); 2022 /* Set up new filter. */ 2023 if (cmd == BIOCSETWF) { 2024 if (d->bd_wfilter != NULL) { 2025 fcode = __containerof((void *)d->bd_wfilter, 2026 struct bpf_program_buffer, buffer); 2027 #ifdef BPF_JITTER 2028 fcode->func = NULL; 2029 #endif 2030 } 2031 d->bd_wfilter = filter; 2032 } else { 2033 if (d->bd_rfilter != NULL) { 2034 fcode = __containerof((void *)d->bd_rfilter, 2035 struct bpf_program_buffer, buffer); 2036 #ifdef BPF_JITTER 2037 fcode->func = d->bd_bfilter; 2038 #endif 2039 } 2040 d->bd_rfilter = filter; 2041 #ifdef BPF_JITTER 2042 d->bd_bfilter = jfunc; 2043 #endif 2044 if (cmd == BIOCSETF) 2045 reset_d(d); 2046 2047 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 2048 /* 2049 * Filter can be set several times without 2050 * specifying interface. In this case just mark d 2051 * as reader. 2052 */ 2053 d->bd_writer = 0; 2054 if (d->bd_bif != NULL) { 2055 /* 2056 * Remove descriptor from writers-only list 2057 * and add it to active readers list. 2058 */ 2059 CK_LIST_REMOVE(d, bd_next); 2060 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 2061 d, bd_next); 2062 CTR2(KTR_NET, 2063 "%s: upgrade required by pid %d", 2064 __func__, d->bd_pid); 2065 track_event = true; 2066 } 2067 } 2068 } 2069 BPFD_UNLOCK(d); 2070 2071 if (fcode != NULL) 2072 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 2073 2074 if (track_event) 2075 EVENTHANDLER_INVOKE(bpf_track, 2076 d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); 2077 2078 BPF_UNLOCK(); 2079 return (0); 2080 } 2081 2082 /* 2083 * Detach a file from its current interface (if attached at all) and attach 2084 * to the interface indicated by the name stored in ifr. 2085 * Return an errno or 0. 2086 */ 2087 static int 2088 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 2089 { 2090 struct bpf_if *bp; 2091 struct ifnet *theywant; 2092 2093 BPF_LOCK_ASSERT(); 2094 2095 theywant = ifunit(ifr->ifr_name); 2096 if (theywant == NULL || theywant->if_bpf == NULL) 2097 return (ENXIO); 2098 2099 bp = theywant->if_bpf; 2100 /* 2101 * At this point, we expect the buffer is already allocated. If not, 2102 * return an error. 2103 */ 2104 switch (d->bd_bufmode) { 2105 case BPF_BUFMODE_BUFFER: 2106 case BPF_BUFMODE_ZBUF: 2107 if (d->bd_sbuf == NULL) 2108 return (EINVAL); 2109 break; 2110 2111 default: 2112 panic("bpf_setif: bufmode %d", d->bd_bufmode); 2113 } 2114 if (bp != d->bd_bif) 2115 bpf_attachd(d, bp); 2116 else { 2117 BPFD_LOCK(d); 2118 reset_d(d); 2119 BPFD_UNLOCK(d); 2120 } 2121 return (0); 2122 } 2123 2124 /* 2125 * Support for select() and poll() system calls 2126 * 2127 * Return true iff the specific operation will not block indefinitely. 2128 * Otherwise, return false but make a note that a selwakeup() must be done. 2129 */ 2130 static int 2131 bpfpoll(struct cdev *dev, int events, struct thread *td) 2132 { 2133 struct bpf_d *d; 2134 int revents; 2135 2136 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2137 return (events & 2138 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 2139 2140 /* 2141 * Refresh PID associated with this descriptor. 2142 */ 2143 revents = events & (POLLOUT | POLLWRNORM); 2144 BPFD_LOCK(d); 2145 BPF_PID_REFRESH(d, td); 2146 if (events & (POLLIN | POLLRDNORM)) { 2147 if (bpf_ready(d)) 2148 revents |= events & (POLLIN | POLLRDNORM); 2149 else { 2150 selrecord(td, &d->bd_sel); 2151 /* Start the read timeout if necessary. */ 2152 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2153 callout_reset(&d->bd_callout, d->bd_rtout, 2154 bpf_timed_out, d); 2155 d->bd_state = BPF_WAITING; 2156 } 2157 } 2158 } 2159 BPFD_UNLOCK(d); 2160 return (revents); 2161 } 2162 2163 /* 2164 * Support for kevent() system call. Register EVFILT_READ filters and 2165 * reject all others. 2166 */ 2167 int 2168 bpfkqfilter(struct cdev *dev, struct knote *kn) 2169 { 2170 struct bpf_d *d; 2171 2172 if (devfs_get_cdevpriv((void **)&d) != 0) 2173 return (1); 2174 2175 switch (kn->kn_filter) { 2176 case EVFILT_READ: 2177 kn->kn_fop = &bpfread_filtops; 2178 break; 2179 2180 case EVFILT_WRITE: 2181 kn->kn_fop = &bpfwrite_filtops; 2182 break; 2183 2184 default: 2185 return (1); 2186 } 2187 2188 /* 2189 * Refresh PID associated with this descriptor. 2190 */ 2191 BPFD_LOCK(d); 2192 BPF_PID_REFRESH_CUR(d); 2193 kn->kn_hook = d; 2194 knlist_add(&d->bd_sel.si_note, kn, 1); 2195 BPFD_UNLOCK(d); 2196 2197 return (0); 2198 } 2199 2200 static void 2201 filt_bpfdetach(struct knote *kn) 2202 { 2203 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2204 2205 knlist_remove(&d->bd_sel.si_note, kn, 0); 2206 } 2207 2208 static int 2209 filt_bpfread(struct knote *kn, long hint) 2210 { 2211 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2212 int ready; 2213 2214 BPFD_LOCK_ASSERT(d); 2215 ready = bpf_ready(d); 2216 if (ready) { 2217 kn->kn_data = d->bd_slen; 2218 /* 2219 * Ignore the hold buffer if it is being copied to user space. 2220 */ 2221 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2222 kn->kn_data += d->bd_hlen; 2223 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2224 callout_reset(&d->bd_callout, d->bd_rtout, 2225 bpf_timed_out, d); 2226 d->bd_state = BPF_WAITING; 2227 } 2228 2229 return (ready); 2230 } 2231 2232 static int 2233 filt_bpfwrite(struct knote *kn, long hint) 2234 { 2235 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2236 2237 BPFD_LOCK_ASSERT(d); 2238 2239 if (d->bd_bif == NULL) { 2240 kn->kn_data = 0; 2241 return (0); 2242 } else { 2243 kn->kn_data = d->bd_bif->bif_ifp->if_mtu; 2244 return (1); 2245 } 2246 } 2247 2248 #define BPF_TSTAMP_NONE 0 2249 #define BPF_TSTAMP_FAST 1 2250 #define BPF_TSTAMP_NORMAL 2 2251 #define BPF_TSTAMP_EXTERN 3 2252 2253 static int 2254 bpf_ts_quality(int tstype) 2255 { 2256 2257 if (tstype == BPF_T_NONE) 2258 return (BPF_TSTAMP_NONE); 2259 if ((tstype & BPF_T_FAST) != 0) 2260 return (BPF_TSTAMP_FAST); 2261 2262 return (BPF_TSTAMP_NORMAL); 2263 } 2264 2265 static int 2266 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2267 { 2268 struct timespec ts; 2269 struct m_tag *tag; 2270 int quality; 2271 2272 quality = bpf_ts_quality(tstype); 2273 if (quality == BPF_TSTAMP_NONE) 2274 return (quality); 2275 2276 if (m != NULL) { 2277 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { 2278 mbuf_tstmp2timespec(m, &ts); 2279 timespec2bintime(&ts, bt); 2280 return (BPF_TSTAMP_EXTERN); 2281 } 2282 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2283 if (tag != NULL) { 2284 *bt = *(struct bintime *)(tag + 1); 2285 return (BPF_TSTAMP_EXTERN); 2286 } 2287 } 2288 if (quality == BPF_TSTAMP_NORMAL) 2289 binuptime(bt); 2290 else 2291 getbinuptime(bt); 2292 2293 return (quality); 2294 } 2295 2296 /* 2297 * Incoming linkage from device drivers. Process the packet pkt, of length 2298 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2299 * by each process' filter, and if accepted, stashed into the corresponding 2300 * buffer. 2301 */ 2302 void 2303 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2304 { 2305 struct epoch_tracker et; 2306 struct bintime bt; 2307 struct bpf_d *d; 2308 #ifdef BPF_JITTER 2309 bpf_jit_filter *bf; 2310 #endif 2311 u_int slen; 2312 int gottime; 2313 2314 gottime = BPF_TSTAMP_NONE; 2315 NET_EPOCH_ENTER(et); 2316 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2317 counter_u64_add(d->bd_rcount, 1); 2318 /* 2319 * NB: We dont call BPF_CHECK_DIRECTION() here since there 2320 * is no way for the caller to indiciate to us whether this 2321 * packet is inbound or outbound. In the bpf_mtap() routines, 2322 * we use the interface pointers on the mbuf to figure it out. 2323 */ 2324 #ifdef BPF_JITTER 2325 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2326 if (bf != NULL) 2327 slen = (*(bf->func))(pkt, pktlen, pktlen); 2328 else 2329 #endif 2330 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2331 if (slen != 0) { 2332 /* 2333 * Filter matches. Let's to acquire write lock. 2334 */ 2335 BPFD_LOCK(d); 2336 counter_u64_add(d->bd_fcount, 1); 2337 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2338 gottime = bpf_gettime(&bt, d->bd_tstamp, 2339 NULL); 2340 #ifdef MAC 2341 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2342 #endif 2343 catchpacket(d, pkt, pktlen, slen, 2344 bpf_append_bytes, &bt); 2345 BPFD_UNLOCK(d); 2346 } 2347 } 2348 NET_EPOCH_EXIT(et); 2349 } 2350 2351 #define BPF_CHECK_DIRECTION(d, r, i) \ 2352 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2353 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2354 2355 /* 2356 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2357 * Locking model is explained in bpf_tap(). 2358 */ 2359 void 2360 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2361 { 2362 struct epoch_tracker et; 2363 struct bintime bt; 2364 struct bpf_d *d; 2365 #ifdef BPF_JITTER 2366 bpf_jit_filter *bf; 2367 #endif 2368 u_int pktlen, slen; 2369 int gottime; 2370 2371 /* Skip outgoing duplicate packets. */ 2372 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2373 m->m_flags &= ~M_PROMISC; 2374 return; 2375 } 2376 2377 pktlen = m_length(m, NULL); 2378 gottime = BPF_TSTAMP_NONE; 2379 2380 NET_EPOCH_ENTER(et); 2381 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2382 if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) 2383 continue; 2384 counter_u64_add(d->bd_rcount, 1); 2385 #ifdef BPF_JITTER 2386 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2387 /* XXX We cannot handle multiple mbufs. */ 2388 if (bf != NULL && m->m_next == NULL) 2389 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2390 pktlen); 2391 else 2392 #endif 2393 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2394 if (slen != 0) { 2395 BPFD_LOCK(d); 2396 2397 counter_u64_add(d->bd_fcount, 1); 2398 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2399 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2400 #ifdef MAC 2401 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2402 #endif 2403 catchpacket(d, (u_char *)m, pktlen, slen, 2404 bpf_append_mbuf, &bt); 2405 BPFD_UNLOCK(d); 2406 } 2407 } 2408 NET_EPOCH_EXIT(et); 2409 } 2410 2411 /* 2412 * Incoming linkage from device drivers, when packet is in 2413 * an mbuf chain and to be prepended by a contiguous header. 2414 */ 2415 void 2416 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2417 { 2418 struct epoch_tracker et; 2419 struct bintime bt; 2420 struct mbuf mb; 2421 struct bpf_d *d; 2422 u_int pktlen, slen; 2423 int gottime; 2424 2425 /* Skip outgoing duplicate packets. */ 2426 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2427 m->m_flags &= ~M_PROMISC; 2428 return; 2429 } 2430 2431 pktlen = m_length(m, NULL); 2432 /* 2433 * Craft on-stack mbuf suitable for passing to bpf_filter. 2434 * Note that we cut corners here; we only setup what's 2435 * absolutely needed--this mbuf should never go anywhere else. 2436 */ 2437 mb.m_flags = 0; 2438 mb.m_next = m; 2439 mb.m_data = data; 2440 mb.m_len = dlen; 2441 pktlen += dlen; 2442 2443 gottime = BPF_TSTAMP_NONE; 2444 2445 NET_EPOCH_ENTER(et); 2446 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2447 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2448 continue; 2449 counter_u64_add(d->bd_rcount, 1); 2450 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2451 if (slen != 0) { 2452 BPFD_LOCK(d); 2453 2454 counter_u64_add(d->bd_fcount, 1); 2455 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2456 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2457 #ifdef MAC 2458 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2459 #endif 2460 catchpacket(d, (u_char *)&mb, pktlen, slen, 2461 bpf_append_mbuf, &bt); 2462 BPFD_UNLOCK(d); 2463 } 2464 } 2465 NET_EPOCH_EXIT(et); 2466 } 2467 2468 #undef BPF_CHECK_DIRECTION 2469 #undef BPF_TSTAMP_NONE 2470 #undef BPF_TSTAMP_FAST 2471 #undef BPF_TSTAMP_NORMAL 2472 #undef BPF_TSTAMP_EXTERN 2473 2474 static int 2475 bpf_hdrlen(struct bpf_d *d) 2476 { 2477 int hdrlen; 2478 2479 hdrlen = d->bd_bif->bif_hdrlen; 2480 #ifndef BURN_BRIDGES 2481 if (d->bd_tstamp == BPF_T_NONE || 2482 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2483 #ifdef COMPAT_FREEBSD32 2484 if (d->bd_compat32) 2485 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2486 else 2487 #endif 2488 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2489 else 2490 #endif 2491 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2492 #ifdef COMPAT_FREEBSD32 2493 if (d->bd_compat32) 2494 hdrlen = BPF_WORDALIGN32(hdrlen); 2495 else 2496 #endif 2497 hdrlen = BPF_WORDALIGN(hdrlen); 2498 2499 return (hdrlen - d->bd_bif->bif_hdrlen); 2500 } 2501 2502 static void 2503 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2504 { 2505 struct bintime bt2, boottimebin; 2506 struct timeval tsm; 2507 struct timespec tsn; 2508 2509 if ((tstype & BPF_T_MONOTONIC) == 0) { 2510 bt2 = *bt; 2511 getboottimebin(&boottimebin); 2512 bintime_add(&bt2, &boottimebin); 2513 bt = &bt2; 2514 } 2515 switch (BPF_T_FORMAT(tstype)) { 2516 case BPF_T_MICROTIME: 2517 bintime2timeval(bt, &tsm); 2518 ts->bt_sec = tsm.tv_sec; 2519 ts->bt_frac = tsm.tv_usec; 2520 break; 2521 case BPF_T_NANOTIME: 2522 bintime2timespec(bt, &tsn); 2523 ts->bt_sec = tsn.tv_sec; 2524 ts->bt_frac = tsn.tv_nsec; 2525 break; 2526 case BPF_T_BINTIME: 2527 ts->bt_sec = bt->sec; 2528 ts->bt_frac = bt->frac; 2529 break; 2530 } 2531 } 2532 2533 /* 2534 * Move the packet data from interface memory (pkt) into the 2535 * store buffer. "cpfn" is the routine called to do the actual data 2536 * transfer. bcopy is passed in to copy contiguous chunks, while 2537 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2538 * pkt is really an mbuf. 2539 */ 2540 static void 2541 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2542 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2543 struct bintime *bt) 2544 { 2545 static char zeroes[BPF_ALIGNMENT]; 2546 struct bpf_xhdr hdr; 2547 #ifndef BURN_BRIDGES 2548 struct bpf_hdr hdr_old; 2549 #ifdef COMPAT_FREEBSD32 2550 struct bpf_hdr32 hdr32_old; 2551 #endif 2552 #endif 2553 int caplen, curlen, hdrlen, pad, totlen; 2554 int do_wakeup = 0; 2555 int do_timestamp; 2556 int tstype; 2557 2558 BPFD_LOCK_ASSERT(d); 2559 if (d->bd_bif == NULL) { 2560 /* Descriptor was detached in concurrent thread */ 2561 counter_u64_add(d->bd_dcount, 1); 2562 return; 2563 } 2564 2565 /* 2566 * Detect whether user space has released a buffer back to us, and if 2567 * so, move it from being a hold buffer to a free buffer. This may 2568 * not be the best place to do it (for example, we might only want to 2569 * run this check if we need the space), but for now it's a reliable 2570 * spot to do it. 2571 */ 2572 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2573 d->bd_fbuf = d->bd_hbuf; 2574 d->bd_hbuf = NULL; 2575 d->bd_hlen = 0; 2576 bpf_buf_reclaimed(d); 2577 } 2578 2579 /* 2580 * Figure out how many bytes to move. If the packet is 2581 * greater or equal to the snapshot length, transfer that 2582 * much. Otherwise, transfer the whole packet (unless 2583 * we hit the buffer size limit). 2584 */ 2585 hdrlen = bpf_hdrlen(d); 2586 totlen = hdrlen + min(snaplen, pktlen); 2587 if (totlen > d->bd_bufsize) 2588 totlen = d->bd_bufsize; 2589 2590 /* 2591 * Round up the end of the previous packet to the next longword. 2592 * 2593 * Drop the packet if there's no room and no hope of room 2594 * If the packet would overflow the storage buffer or the storage 2595 * buffer is considered immutable by the buffer model, try to rotate 2596 * the buffer and wakeup pending processes. 2597 */ 2598 #ifdef COMPAT_FREEBSD32 2599 if (d->bd_compat32) 2600 curlen = BPF_WORDALIGN32(d->bd_slen); 2601 else 2602 #endif 2603 curlen = BPF_WORDALIGN(d->bd_slen); 2604 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2605 if (d->bd_fbuf == NULL) { 2606 /* 2607 * There's no room in the store buffer, and no 2608 * prospect of room, so drop the packet. Notify the 2609 * buffer model. 2610 */ 2611 bpf_buffull(d); 2612 counter_u64_add(d->bd_dcount, 1); 2613 return; 2614 } 2615 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2616 ROTATE_BUFFERS(d); 2617 do_wakeup = 1; 2618 curlen = 0; 2619 } else { 2620 if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { 2621 /* 2622 * Immediate mode is set, or the read timeout has 2623 * already expired during a select call. A packet 2624 * arrived, so the reader should be woken up. 2625 */ 2626 do_wakeup = 1; 2627 } 2628 pad = curlen - d->bd_slen; 2629 KASSERT(pad >= 0 && pad <= sizeof(zeroes), 2630 ("%s: invalid pad byte count %d", __func__, pad)); 2631 if (pad > 0) { 2632 /* Zero pad bytes. */ 2633 bpf_append_bytes(d, d->bd_sbuf, d->bd_slen, zeroes, 2634 pad); 2635 } 2636 } 2637 2638 caplen = totlen - hdrlen; 2639 tstype = d->bd_tstamp; 2640 do_timestamp = tstype != BPF_T_NONE; 2641 #ifndef BURN_BRIDGES 2642 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2643 struct bpf_ts ts; 2644 if (do_timestamp) 2645 bpf_bintime2ts(bt, &ts, tstype); 2646 #ifdef COMPAT_FREEBSD32 2647 if (d->bd_compat32) { 2648 bzero(&hdr32_old, sizeof(hdr32_old)); 2649 if (do_timestamp) { 2650 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2651 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2652 } 2653 hdr32_old.bh_datalen = pktlen; 2654 hdr32_old.bh_hdrlen = hdrlen; 2655 hdr32_old.bh_caplen = caplen; 2656 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2657 sizeof(hdr32_old)); 2658 goto copy; 2659 } 2660 #endif 2661 bzero(&hdr_old, sizeof(hdr_old)); 2662 if (do_timestamp) { 2663 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2664 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2665 } 2666 hdr_old.bh_datalen = pktlen; 2667 hdr_old.bh_hdrlen = hdrlen; 2668 hdr_old.bh_caplen = caplen; 2669 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2670 sizeof(hdr_old)); 2671 goto copy; 2672 } 2673 #endif 2674 2675 /* 2676 * Append the bpf header. Note we append the actual header size, but 2677 * move forward the length of the header plus padding. 2678 */ 2679 bzero(&hdr, sizeof(hdr)); 2680 if (do_timestamp) 2681 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2682 hdr.bh_datalen = pktlen; 2683 hdr.bh_hdrlen = hdrlen; 2684 hdr.bh_caplen = caplen; 2685 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2686 2687 /* 2688 * Copy the packet data into the store buffer and update its length. 2689 */ 2690 #ifndef BURN_BRIDGES 2691 copy: 2692 #endif 2693 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2694 d->bd_slen = curlen + totlen; 2695 2696 if (do_wakeup) 2697 bpf_wakeup(d); 2698 } 2699 2700 /* 2701 * Free buffers currently in use by a descriptor. 2702 * Called on close. 2703 */ 2704 static void 2705 bpfd_free(epoch_context_t ctx) 2706 { 2707 struct bpf_d *d; 2708 struct bpf_program_buffer *p; 2709 2710 /* 2711 * We don't need to lock out interrupts since this descriptor has 2712 * been detached from its interface and it yet hasn't been marked 2713 * free. 2714 */ 2715 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2716 bpf_free(d); 2717 if (d->bd_rfilter != NULL) { 2718 p = __containerof((void *)d->bd_rfilter, 2719 struct bpf_program_buffer, buffer); 2720 #ifdef BPF_JITTER 2721 p->func = d->bd_bfilter; 2722 #endif 2723 bpf_program_buffer_free(&p->epoch_ctx); 2724 } 2725 if (d->bd_wfilter != NULL) { 2726 p = __containerof((void *)d->bd_wfilter, 2727 struct bpf_program_buffer, buffer); 2728 #ifdef BPF_JITTER 2729 p->func = NULL; 2730 #endif 2731 bpf_program_buffer_free(&p->epoch_ctx); 2732 } 2733 2734 mtx_destroy(&d->bd_lock); 2735 counter_u64_free(d->bd_rcount); 2736 counter_u64_free(d->bd_dcount); 2737 counter_u64_free(d->bd_fcount); 2738 counter_u64_free(d->bd_wcount); 2739 counter_u64_free(d->bd_wfcount); 2740 counter_u64_free(d->bd_wdcount); 2741 counter_u64_free(d->bd_zcopy); 2742 free(d, M_BPF); 2743 } 2744 2745 /* 2746 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2747 * fixed size of the link header (variable length headers not yet supported). 2748 */ 2749 void 2750 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2751 { 2752 2753 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2754 } 2755 2756 /* 2757 * Attach an interface to bpf. ifp is a pointer to the structure 2758 * defining the interface to be attached, dlt is the link layer type, 2759 * and hdrlen is the fixed size of the link header (variable length 2760 * headers are not yet supporrted). 2761 */ 2762 void 2763 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, 2764 struct bpf_if **driverp) 2765 { 2766 struct bpf_if *bp; 2767 2768 KASSERT(*driverp == NULL, 2769 ("bpfattach2: driverp already initialized")); 2770 2771 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2772 2773 CK_LIST_INIT(&bp->bif_dlist); 2774 CK_LIST_INIT(&bp->bif_wlist); 2775 bp->bif_ifp = ifp; 2776 bp->bif_dlt = dlt; 2777 bp->bif_hdrlen = hdrlen; 2778 bp->bif_bpf = driverp; 2779 refcount_init(&bp->bif_refcnt, 1); 2780 *driverp = bp; 2781 /* 2782 * Reference ifnet pointer, so it won't freed until 2783 * we release it. 2784 */ 2785 if_ref(ifp); 2786 BPF_LOCK(); 2787 CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2788 BPF_UNLOCK(); 2789 2790 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2791 if_printf(ifp, "bpf attached\n"); 2792 } 2793 2794 #ifdef VIMAGE 2795 /* 2796 * When moving interfaces between vnet instances we need a way to 2797 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2798 * after the vmove. We unfortunately have no device driver infrastructure 2799 * to query the interface for these values after creation/attach, thus 2800 * add this as a workaround. 2801 */ 2802 int 2803 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2804 { 2805 2806 if (bp == NULL) 2807 return (ENXIO); 2808 if (bif_dlt == NULL && bif_hdrlen == NULL) 2809 return (0); 2810 2811 if (bif_dlt != NULL) 2812 *bif_dlt = bp->bif_dlt; 2813 if (bif_hdrlen != NULL) 2814 *bif_hdrlen = bp->bif_hdrlen; 2815 2816 return (0); 2817 } 2818 #endif 2819 2820 /* 2821 * Detach bpf from an interface. This involves detaching each descriptor 2822 * associated with the interface. Notify each descriptor as it's detached 2823 * so that any sleepers wake up and get ENXIO. 2824 */ 2825 void 2826 bpfdetach(struct ifnet *ifp) 2827 { 2828 struct bpf_if *bp, *bp_temp; 2829 struct bpf_d *d; 2830 2831 BPF_LOCK(); 2832 /* Find all bpf_if struct's which reference ifp and detach them. */ 2833 CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2834 if (ifp != bp->bif_ifp) 2835 continue; 2836 2837 CK_LIST_REMOVE(bp, bif_next); 2838 *bp->bif_bpf = (struct bpf_if *)&dead_bpf_if; 2839 2840 CTR4(KTR_NET, 2841 "%s: sheduling free for encap %d (%p) for if %p", 2842 __func__, bp->bif_dlt, bp, ifp); 2843 2844 /* Detach common descriptors */ 2845 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2846 bpf_detachd_locked(d, true); 2847 } 2848 2849 /* Detach writer-only descriptors */ 2850 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2851 bpf_detachd_locked(d, true); 2852 } 2853 bpfif_rele(bp); 2854 } 2855 BPF_UNLOCK(); 2856 } 2857 2858 /* 2859 * Get a list of available data link type of the interface. 2860 */ 2861 static int 2862 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2863 { 2864 struct ifnet *ifp; 2865 struct bpf_if *bp; 2866 u_int *lst; 2867 int error, n, n1; 2868 2869 BPF_LOCK_ASSERT(); 2870 2871 ifp = d->bd_bif->bif_ifp; 2872 n1 = 0; 2873 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2874 if (bp->bif_ifp == ifp) 2875 n1++; 2876 } 2877 if (bfl->bfl_list == NULL) { 2878 bfl->bfl_len = n1; 2879 return (0); 2880 } 2881 if (n1 > bfl->bfl_len) 2882 return (ENOMEM); 2883 2884 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2885 n = 0; 2886 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2887 if (bp->bif_ifp != ifp) 2888 continue; 2889 lst[n++] = bp->bif_dlt; 2890 } 2891 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2892 free(lst, M_TEMP); 2893 bfl->bfl_len = n; 2894 return (error); 2895 } 2896 2897 /* 2898 * Set the data link type of a BPF instance. 2899 */ 2900 static int 2901 bpf_setdlt(struct bpf_d *d, u_int dlt) 2902 { 2903 int error, opromisc; 2904 struct ifnet *ifp; 2905 struct bpf_if *bp; 2906 2907 BPF_LOCK_ASSERT(); 2908 MPASS(d->bd_bif != NULL); 2909 2910 /* 2911 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2912 * changed while we hold global lock. 2913 */ 2914 if (d->bd_bif->bif_dlt == dlt) 2915 return (0); 2916 2917 ifp = d->bd_bif->bif_ifp; 2918 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2919 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2920 break; 2921 } 2922 if (bp == NULL) 2923 return (EINVAL); 2924 2925 opromisc = d->bd_promisc; 2926 bpf_attachd(d, bp); 2927 if (opromisc) { 2928 error = ifpromisc(bp->bif_ifp, 1); 2929 if (error) 2930 if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", 2931 __func__, error); 2932 else 2933 d->bd_promisc = 1; 2934 } 2935 return (0); 2936 } 2937 2938 static void 2939 bpf_drvinit(void *unused) 2940 { 2941 struct cdev *dev; 2942 2943 sx_init(&bpf_sx, "bpf global lock"); 2944 CK_LIST_INIT(&bpf_iflist); 2945 2946 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2947 /* For compatibility */ 2948 make_dev_alias(dev, "bpf0"); 2949 } 2950 2951 /* 2952 * Zero out the various packet counters associated with all of the bpf 2953 * descriptors. At some point, we will probably want to get a bit more 2954 * granular and allow the user to specify descriptors to be zeroed. 2955 */ 2956 static void 2957 bpf_zero_counters(void) 2958 { 2959 struct bpf_if *bp; 2960 struct bpf_d *bd; 2961 2962 BPF_LOCK(); 2963 /* 2964 * We are protected by global lock here, interfaces and 2965 * descriptors can not be deleted while we hold it. 2966 */ 2967 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2968 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2969 counter_u64_zero(bd->bd_rcount); 2970 counter_u64_zero(bd->bd_dcount); 2971 counter_u64_zero(bd->bd_fcount); 2972 counter_u64_zero(bd->bd_wcount); 2973 counter_u64_zero(bd->bd_wfcount); 2974 counter_u64_zero(bd->bd_zcopy); 2975 } 2976 } 2977 BPF_UNLOCK(); 2978 } 2979 2980 /* 2981 * Fill filter statistics 2982 */ 2983 static void 2984 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2985 { 2986 2987 BPF_LOCK_ASSERT(); 2988 bzero(d, sizeof(*d)); 2989 d->bd_structsize = sizeof(*d); 2990 d->bd_immediate = bd->bd_immediate; 2991 d->bd_promisc = bd->bd_promisc; 2992 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2993 d->bd_direction = bd->bd_direction; 2994 d->bd_feedback = bd->bd_feedback; 2995 d->bd_async = bd->bd_async; 2996 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2997 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2998 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2999 d->bd_sig = bd->bd_sig; 3000 d->bd_slen = bd->bd_slen; 3001 d->bd_hlen = bd->bd_hlen; 3002 d->bd_bufsize = bd->bd_bufsize; 3003 d->bd_pid = bd->bd_pid; 3004 strlcpy(d->bd_ifname, 3005 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 3006 d->bd_locked = bd->bd_locked; 3007 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 3008 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 3009 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 3010 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 3011 d->bd_bufmode = bd->bd_bufmode; 3012 } 3013 3014 /* 3015 * Handle `netstat -B' stats request 3016 */ 3017 static int 3018 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 3019 { 3020 static const struct xbpf_d zerostats; 3021 struct xbpf_d *xbdbuf, *xbd, tempstats; 3022 int index, error; 3023 struct bpf_if *bp; 3024 struct bpf_d *bd; 3025 3026 /* 3027 * XXX This is not technically correct. It is possible for non 3028 * privileged users to open bpf devices. It would make sense 3029 * if the users who opened the devices were able to retrieve 3030 * the statistics for them, too. 3031 */ 3032 error = priv_check(req->td, PRIV_NET_BPF); 3033 if (error) 3034 return (error); 3035 /* 3036 * Check to see if the user is requesting that the counters be 3037 * zeroed out. Explicitly check that the supplied data is zeroed, 3038 * as we aren't allowing the user to set the counters currently. 3039 */ 3040 if (req->newptr != NULL) { 3041 if (req->newlen != sizeof(tempstats)) 3042 return (EINVAL); 3043 memset(&tempstats, 0, sizeof(tempstats)); 3044 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 3045 if (error) 3046 return (error); 3047 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 3048 return (EINVAL); 3049 bpf_zero_counters(); 3050 return (0); 3051 } 3052 if (req->oldptr == NULL) 3053 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 3054 if (bpf_bpfd_cnt == 0) 3055 return (SYSCTL_OUT(req, 0, 0)); 3056 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 3057 BPF_LOCK(); 3058 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 3059 BPF_UNLOCK(); 3060 free(xbdbuf, M_BPF); 3061 return (ENOMEM); 3062 } 3063 index = 0; 3064 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 3065 /* Send writers-only first */ 3066 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 3067 xbd = &xbdbuf[index++]; 3068 bpfstats_fill_xbpf(xbd, bd); 3069 } 3070 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 3071 xbd = &xbdbuf[index++]; 3072 bpfstats_fill_xbpf(xbd, bd); 3073 } 3074 } 3075 BPF_UNLOCK(); 3076 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 3077 free(xbdbuf, M_BPF); 3078 return (error); 3079 } 3080 3081 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 3082 3083 #else /* !DEV_BPF && !NETGRAPH_BPF */ 3084 3085 /* 3086 * NOP stubs to allow bpf-using drivers to load and function. 3087 * 3088 * A 'better' implementation would allow the core bpf functionality 3089 * to be loaded at runtime. 3090 */ 3091 3092 void 3093 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3094 { 3095 } 3096 3097 void 3098 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3099 { 3100 } 3101 3102 void 3103 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3104 { 3105 } 3106 3107 void 3108 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3109 { 3110 3111 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3112 } 3113 3114 void 3115 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3116 { 3117 3118 *driverp = (struct bpf_if *)&dead_bpf_if; 3119 } 3120 3121 void 3122 bpfdetach(struct ifnet *ifp) 3123 { 3124 } 3125 3126 u_int 3127 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3128 { 3129 return -1; /* "no filter" behaviour */ 3130 } 3131 3132 int 3133 bpf_validate(const struct bpf_insn *f, int len) 3134 { 3135 return 0; /* false */ 3136 } 3137 3138 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3139 3140 #ifdef DDB 3141 static void 3142 bpf_show_bpf_if(struct bpf_if *bpf_if) 3143 { 3144 3145 if (bpf_if == NULL) 3146 return; 3147 db_printf("%p:\n", bpf_if); 3148 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3149 #define BPF_DB_PRINTF_RAW(f, e) db_printf(" %s = " f "\n", #e, e); 3150 /* bif_ext.bif_next */ 3151 /* bif_ext.bif_dlist */ 3152 BPF_DB_PRINTF("%#x", bif_dlt); 3153 BPF_DB_PRINTF("%u", bif_hdrlen); 3154 /* bif_wlist */ 3155 BPF_DB_PRINTF("%p", bif_ifp); 3156 BPF_DB_PRINTF("%p", bif_bpf); 3157 BPF_DB_PRINTF_RAW("%u", refcount_load(&bpf_if->bif_refcnt)); 3158 } 3159 3160 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3161 { 3162 3163 if (!have_addr) { 3164 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3165 return; 3166 } 3167 3168 bpf_show_bpf_if((struct bpf_if *)addr); 3169 } 3170 #endif 3171