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 BPFD_UNLOCK(d); 767 bpf_bpfd_cnt++; 768 769 CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", 770 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 771 772 if (op_w == 0) 773 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 774 } 775 776 /* 777 * Check if we need to upgrade our descriptor @d from write-only mode. 778 */ 779 static int 780 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 781 int flen) 782 { 783 int is_snap, need_upgrade; 784 785 /* 786 * Check if we've already upgraded or new filter is empty. 787 */ 788 if (d->bd_writer == 0 || fcode == NULL) 789 return (0); 790 791 need_upgrade = 0; 792 793 /* 794 * Check if cmd looks like snaplen setting from 795 * pcap_bpf.c:pcap_open_live(). 796 * Note we're not checking .k value here: 797 * while pcap_open_live() definitely sets to non-zero value, 798 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 799 * do not consider upgrading immediately 800 */ 801 if (cmd == BIOCSETF && flen == 1 && 802 fcode[0].code == (BPF_RET | BPF_K)) 803 is_snap = 1; 804 else 805 is_snap = 0; 806 807 if (is_snap == 0) { 808 /* 809 * We're setting first filter and it doesn't look like 810 * setting snaplen. We're probably using bpf directly. 811 * Upgrade immediately. 812 */ 813 need_upgrade = 1; 814 } else { 815 /* 816 * Do not require upgrade by first BIOCSETF 817 * (used to set snaplen) by pcap_open_live(). 818 */ 819 820 if (--d->bd_writer == 0) { 821 /* 822 * First snaplen filter has already 823 * been set. This is probably catch-all 824 * filter 825 */ 826 need_upgrade = 1; 827 } 828 } 829 830 CTR5(KTR_NET, 831 "%s: filter function set by pid %d, " 832 "bd_writer counter %d, snap %d upgrade %d", 833 __func__, d->bd_pid, d->bd_writer, 834 is_snap, need_upgrade); 835 836 return (need_upgrade); 837 } 838 839 /* 840 * Detach a file from its interface. 841 */ 842 static void 843 bpf_detachd(struct bpf_d *d) 844 { 845 BPF_LOCK(); 846 bpf_detachd_locked(d, false); 847 BPF_UNLOCK(); 848 } 849 850 static void 851 bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) 852 { 853 struct bpf_if *bp; 854 struct ifnet *ifp; 855 int error; 856 857 BPF_LOCK_ASSERT(); 858 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 859 860 /* Check if descriptor is attached */ 861 if ((bp = d->bd_bif) == NULL) 862 return; 863 864 BPFD_LOCK(d); 865 /* Remove d from the interface's descriptor list. */ 866 CK_LIST_REMOVE(d, bd_next); 867 /* Save bd_writer value */ 868 error = d->bd_writer; 869 ifp = bp->bif_ifp; 870 d->bd_bif = NULL; 871 if (detached_ifp) { 872 /* 873 * Notify descriptor as it's detached, so that any 874 * sleepers wake up and get ENXIO. 875 */ 876 bpf_wakeup(d); 877 } 878 BPFD_UNLOCK(d); 879 bpf_bpfd_cnt--; 880 881 /* Call event handler iff d is attached */ 882 if (error == 0) 883 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 884 885 /* 886 * Check if this descriptor had requested promiscuous mode. 887 * If so and ifnet is not detached, turn it off. 888 */ 889 if (d->bd_promisc && !detached_ifp) { 890 d->bd_promisc = 0; 891 CURVNET_SET(ifp->if_vnet); 892 error = ifpromisc(ifp, 0); 893 CURVNET_RESTORE(); 894 if (error != 0 && error != ENXIO) { 895 /* 896 * ENXIO can happen if a pccard is unplugged 897 * Something is really wrong if we were able to put 898 * the driver into promiscuous mode, but can't 899 * take it out. 900 */ 901 if_printf(bp->bif_ifp, 902 "bpf_detach: ifpromisc failed (%d)\n", error); 903 } 904 } 905 bpfif_rele(bp); 906 } 907 908 /* 909 * Close the descriptor by detaching it from its interface, 910 * deallocating its buffers, and marking it free. 911 */ 912 static void 913 bpf_dtor(void *data) 914 { 915 struct bpf_d *d = data; 916 917 BPFD_LOCK(d); 918 if (d->bd_state == BPF_WAITING) 919 callout_stop(&d->bd_callout); 920 d->bd_state = BPF_IDLE; 921 BPFD_UNLOCK(d); 922 funsetown(&d->bd_sigio); 923 bpf_detachd(d); 924 #ifdef MAC 925 mac_bpfdesc_destroy(d); 926 #endif /* MAC */ 927 seldrain(&d->bd_sel); 928 knlist_destroy(&d->bd_sel.si_note); 929 callout_drain(&d->bd_callout); 930 bpfd_rele(d); 931 } 932 933 /* 934 * Open ethernet device. Returns ENXIO for illegal minor device number, 935 * EBUSY if file is open by another process. 936 */ 937 /* ARGSUSED */ 938 static int 939 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 940 { 941 struct bpf_d *d; 942 int error; 943 944 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 945 error = devfs_set_cdevpriv(d, bpf_dtor); 946 if (error != 0) { 947 free(d, M_BPF); 948 return (error); 949 } 950 951 /* Setup counters */ 952 d->bd_rcount = counter_u64_alloc(M_WAITOK); 953 d->bd_dcount = counter_u64_alloc(M_WAITOK); 954 d->bd_fcount = counter_u64_alloc(M_WAITOK); 955 d->bd_wcount = counter_u64_alloc(M_WAITOK); 956 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 957 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 958 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 959 960 /* 961 * For historical reasons, perform a one-time initialization call to 962 * the buffer routines, even though we're not yet committed to a 963 * particular buffer method. 964 */ 965 bpf_buffer_init(d); 966 if ((flags & FREAD) == 0) 967 d->bd_writer = 2; 968 d->bd_hbuf_in_use = 0; 969 d->bd_bufmode = BPF_BUFMODE_BUFFER; 970 d->bd_sig = SIGIO; 971 d->bd_direction = BPF_D_INOUT; 972 d->bd_refcnt = 1; 973 BPF_PID_REFRESH(d, td); 974 #ifdef MAC 975 mac_bpfdesc_init(d); 976 mac_bpfdesc_create(td->td_ucred, d); 977 #endif 978 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 979 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 980 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 981 982 /* Disable VLAN pcp tagging. */ 983 d->bd_pcp = 0; 984 985 return (0); 986 } 987 988 /* 989 * bpfread - read next chunk of packets from buffers 990 */ 991 static int 992 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 993 { 994 struct bpf_d *d; 995 int error; 996 int non_block; 997 int timed_out; 998 999 error = devfs_get_cdevpriv((void **)&d); 1000 if (error != 0) 1001 return (error); 1002 1003 /* 1004 * Restrict application to use a buffer the same size as 1005 * as kernel buffers. 1006 */ 1007 if (uio->uio_resid != d->bd_bufsize) 1008 return (EINVAL); 1009 1010 non_block = ((ioflag & O_NONBLOCK) != 0); 1011 1012 BPFD_LOCK(d); 1013 BPF_PID_REFRESH_CUR(d); 1014 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 1015 BPFD_UNLOCK(d); 1016 return (EOPNOTSUPP); 1017 } 1018 if (d->bd_state == BPF_WAITING) 1019 callout_stop(&d->bd_callout); 1020 timed_out = (d->bd_state == BPF_TIMED_OUT); 1021 d->bd_state = BPF_IDLE; 1022 while (d->bd_hbuf_in_use) { 1023 error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1024 PRINET|PCATCH, "bd_hbuf", 0); 1025 if (error != 0) { 1026 BPFD_UNLOCK(d); 1027 return (error); 1028 } 1029 } 1030 /* 1031 * If the hold buffer is empty, then do a timed sleep, which 1032 * ends when the timeout expires or when enough packets 1033 * have arrived to fill the store buffer. 1034 */ 1035 while (d->bd_hbuf == NULL) { 1036 if (d->bd_slen != 0) { 1037 /* 1038 * A packet(s) either arrived since the previous 1039 * read or arrived while we were asleep. 1040 */ 1041 if (d->bd_immediate || non_block || timed_out) { 1042 /* 1043 * Rotate the buffers and return what's here 1044 * if we are in immediate mode, non-blocking 1045 * flag is set, or this descriptor timed out. 1046 */ 1047 ROTATE_BUFFERS(d); 1048 break; 1049 } 1050 } 1051 1052 /* 1053 * No data is available, check to see if the bpf device 1054 * is still pointed at a real interface. If not, return 1055 * ENXIO so that the userland process knows to rebind 1056 * it before using it again. 1057 */ 1058 if (d->bd_bif == NULL) { 1059 BPFD_UNLOCK(d); 1060 return (ENXIO); 1061 } 1062 1063 if (non_block) { 1064 BPFD_UNLOCK(d); 1065 return (EWOULDBLOCK); 1066 } 1067 error = msleep(d, &d->bd_lock, PRINET|PCATCH, 1068 "bpf", d->bd_rtout); 1069 if (error == EINTR || error == ERESTART) { 1070 BPFD_UNLOCK(d); 1071 return (error); 1072 } 1073 if (error == EWOULDBLOCK) { 1074 /* 1075 * On a timeout, return what's in the buffer, 1076 * which may be nothing. If there is something 1077 * in the store buffer, we can rotate the buffers. 1078 */ 1079 if (d->bd_hbuf) 1080 /* 1081 * We filled up the buffer in between 1082 * getting the timeout and arriving 1083 * here, so we don't need to rotate. 1084 */ 1085 break; 1086 1087 if (d->bd_slen == 0) { 1088 BPFD_UNLOCK(d); 1089 return (0); 1090 } 1091 ROTATE_BUFFERS(d); 1092 break; 1093 } 1094 } 1095 /* 1096 * At this point, we know we have something in the hold slot. 1097 */ 1098 d->bd_hbuf_in_use = 1; 1099 BPFD_UNLOCK(d); 1100 1101 /* 1102 * Move data from hold buffer into user space. 1103 * We know the entire buffer is transferred since 1104 * we checked above that the read buffer is bpf_bufsize bytes. 1105 * 1106 * We do not have to worry about simultaneous reads because 1107 * we waited for sole access to the hold buffer above. 1108 */ 1109 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 1110 1111 BPFD_LOCK(d); 1112 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 1113 d->bd_fbuf = d->bd_hbuf; 1114 d->bd_hbuf = NULL; 1115 d->bd_hlen = 0; 1116 bpf_buf_reclaimed(d); 1117 d->bd_hbuf_in_use = 0; 1118 wakeup(&d->bd_hbuf_in_use); 1119 BPFD_UNLOCK(d); 1120 1121 return (error); 1122 } 1123 1124 /* 1125 * If there are processes sleeping on this descriptor, wake them up. 1126 */ 1127 static __inline void 1128 bpf_wakeup(struct bpf_d *d) 1129 { 1130 1131 BPFD_LOCK_ASSERT(d); 1132 if (d->bd_state == BPF_WAITING) { 1133 callout_stop(&d->bd_callout); 1134 d->bd_state = BPF_IDLE; 1135 } 1136 wakeup(d); 1137 if (d->bd_async && d->bd_sig && d->bd_sigio) 1138 pgsigio(&d->bd_sigio, d->bd_sig, 0); 1139 1140 selwakeuppri(&d->bd_sel, PRINET); 1141 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 1142 } 1143 1144 static void 1145 bpf_timed_out(void *arg) 1146 { 1147 struct bpf_d *d = (struct bpf_d *)arg; 1148 1149 BPFD_LOCK_ASSERT(d); 1150 1151 if (callout_pending(&d->bd_callout) || 1152 !callout_active(&d->bd_callout)) 1153 return; 1154 if (d->bd_state == BPF_WAITING) { 1155 d->bd_state = BPF_TIMED_OUT; 1156 if (d->bd_slen != 0) 1157 bpf_wakeup(d); 1158 } 1159 } 1160 1161 static int 1162 bpf_ready(struct bpf_d *d) 1163 { 1164 1165 BPFD_LOCK_ASSERT(d); 1166 1167 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 1168 return (1); 1169 if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1170 d->bd_slen != 0) 1171 return (1); 1172 return (0); 1173 } 1174 1175 static int 1176 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 1177 { 1178 struct route ro; 1179 struct sockaddr dst; 1180 struct epoch_tracker et; 1181 struct bpf_if *bp; 1182 struct bpf_d *d; 1183 struct ifnet *ifp; 1184 struct mbuf *m, *mc; 1185 int error, hlen; 1186 1187 error = devfs_get_cdevpriv((void **)&d); 1188 if (error != 0) 1189 return (error); 1190 1191 NET_EPOCH_ENTER(et); 1192 BPFD_LOCK(d); 1193 BPF_PID_REFRESH_CUR(d); 1194 counter_u64_add(d->bd_wcount, 1); 1195 if ((bp = d->bd_bif) == NULL) { 1196 error = ENXIO; 1197 goto out_locked; 1198 } 1199 1200 ifp = bp->bif_ifp; 1201 if ((ifp->if_flags & IFF_UP) == 0) { 1202 error = ENETDOWN; 1203 goto out_locked; 1204 } 1205 1206 if (uio->uio_resid == 0) 1207 goto out_locked; 1208 1209 bzero(&dst, sizeof(dst)); 1210 m = NULL; 1211 hlen = 0; 1212 1213 /* 1214 * Take extra reference, unlock d and exit from epoch section, 1215 * since bpf_movein() can sleep. 1216 */ 1217 bpfd_ref(d); 1218 NET_EPOCH_EXIT(et); 1219 BPFD_UNLOCK(d); 1220 1221 error = bpf_movein(uio, (int)bp->bif_dlt, ifp, 1222 &m, &dst, &hlen, d); 1223 1224 if (error != 0) { 1225 counter_u64_add(d->bd_wdcount, 1); 1226 bpfd_rele(d); 1227 return (error); 1228 } 1229 1230 BPFD_LOCK(d); 1231 /* 1232 * Check that descriptor is still attached to the interface. 1233 * This can happen on bpfdetach(). To avoid access to detached 1234 * ifnet, free mbuf and return ENXIO. 1235 */ 1236 if (d->bd_bif == NULL) { 1237 counter_u64_add(d->bd_wdcount, 1); 1238 BPFD_UNLOCK(d); 1239 bpfd_rele(d); 1240 m_freem(m); 1241 return (ENXIO); 1242 } 1243 counter_u64_add(d->bd_wfcount, 1); 1244 if (d->bd_hdrcmplt) 1245 dst.sa_family = pseudo_AF_HDRCMPLT; 1246 1247 if (d->bd_feedback) { 1248 mc = m_dup(m, M_NOWAIT); 1249 if (mc != NULL) 1250 mc->m_pkthdr.rcvif = ifp; 1251 /* Set M_PROMISC for outgoing packets to be discarded. */ 1252 if (d->bd_direction == BPF_D_INOUT) 1253 m->m_flags |= M_PROMISC; 1254 } else 1255 mc = NULL; 1256 1257 m->m_pkthdr.len -= hlen; 1258 m->m_len -= hlen; 1259 m->m_data += hlen; /* XXX */ 1260 1261 CURVNET_SET(ifp->if_vnet); 1262 #ifdef MAC 1263 mac_bpfdesc_create_mbuf(d, m); 1264 if (mc != NULL) 1265 mac_bpfdesc_create_mbuf(d, mc); 1266 #endif 1267 1268 bzero(&ro, sizeof(ro)); 1269 if (hlen != 0) { 1270 ro.ro_prepend = (u_char *)&dst.sa_data; 1271 ro.ro_plen = hlen; 1272 ro.ro_flags = RT_HAS_HEADER; 1273 } 1274 1275 if (d->bd_pcp != 0) 1276 vlan_set_pcp(m, d->bd_pcp); 1277 1278 /* Avoid possible recursion on BPFD_LOCK(). */ 1279 NET_EPOCH_ENTER(et); 1280 BPFD_UNLOCK(d); 1281 error = (*ifp->if_output)(ifp, m, &dst, &ro); 1282 if (error) 1283 counter_u64_add(d->bd_wdcount, 1); 1284 1285 if (mc != NULL) { 1286 if (error == 0) 1287 (*ifp->if_input)(ifp, mc); 1288 else 1289 m_freem(mc); 1290 } 1291 NET_EPOCH_EXIT(et); 1292 CURVNET_RESTORE(); 1293 bpfd_rele(d); 1294 return (error); 1295 1296 out_locked: 1297 counter_u64_add(d->bd_wdcount, 1); 1298 NET_EPOCH_EXIT(et); 1299 BPFD_UNLOCK(d); 1300 return (error); 1301 } 1302 1303 /* 1304 * Reset a descriptor by flushing its packet buffer and clearing the receive 1305 * and drop counts. This is doable for kernel-only buffers, but with 1306 * zero-copy buffers, we can't write to (or rotate) buffers that are 1307 * currently owned by userspace. It would be nice if we could encapsulate 1308 * this logic in the buffer code rather than here. 1309 */ 1310 static void 1311 reset_d(struct bpf_d *d) 1312 { 1313 1314 BPFD_LOCK_ASSERT(d); 1315 1316 while (d->bd_hbuf_in_use) 1317 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, 1318 "bd_hbuf", 0); 1319 if ((d->bd_hbuf != NULL) && 1320 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1321 /* Free the hold buffer. */ 1322 d->bd_fbuf = d->bd_hbuf; 1323 d->bd_hbuf = NULL; 1324 d->bd_hlen = 0; 1325 bpf_buf_reclaimed(d); 1326 } 1327 if (bpf_canwritebuf(d)) 1328 d->bd_slen = 0; 1329 counter_u64_zero(d->bd_rcount); 1330 counter_u64_zero(d->bd_dcount); 1331 counter_u64_zero(d->bd_fcount); 1332 counter_u64_zero(d->bd_wcount); 1333 counter_u64_zero(d->bd_wfcount); 1334 counter_u64_zero(d->bd_wdcount); 1335 counter_u64_zero(d->bd_zcopy); 1336 } 1337 1338 /* 1339 * FIONREAD Check for read packet available. 1340 * BIOCGBLEN Get buffer len [for read()]. 1341 * BIOCSETF Set read filter. 1342 * BIOCSETFNR Set read filter without resetting descriptor. 1343 * BIOCSETWF Set write filter. 1344 * BIOCFLUSH Flush read packet buffer. 1345 * BIOCPROMISC Put interface into promiscuous mode. 1346 * BIOCGDLT Get link layer type. 1347 * BIOCGETIF Get interface name. 1348 * BIOCSETIF Set interface. 1349 * BIOCSRTIMEOUT Set read timeout. 1350 * BIOCGRTIMEOUT Get read timeout. 1351 * BIOCGSTATS Get packet stats. 1352 * BIOCIMMEDIATE Set immediate mode. 1353 * BIOCVERSION Get filter language version. 1354 * BIOCGHDRCMPLT Get "header already complete" flag 1355 * BIOCSHDRCMPLT Set "header already complete" flag 1356 * BIOCGDIRECTION Get packet direction flag 1357 * BIOCSDIRECTION Set packet direction flag 1358 * BIOCGTSTAMP Get time stamp format and resolution. 1359 * BIOCSTSTAMP Set time stamp format and resolution. 1360 * BIOCLOCK Set "locked" flag 1361 * BIOCFEEDBACK Set packet feedback mode. 1362 * BIOCSETZBUF Set current zero-copy buffer locations. 1363 * BIOCGETZMAX Get maximum zero-copy buffer size. 1364 * BIOCROTZBUF Force rotation of zero-copy buffer 1365 * BIOCSETBUFMODE Set buffer mode. 1366 * BIOCGETBUFMODE Get current buffer mode. 1367 * BIOCSETVLANPCP Set VLAN PCP tag. 1368 */ 1369 /* ARGSUSED */ 1370 static int 1371 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1372 struct thread *td) 1373 { 1374 struct bpf_d *d; 1375 int error; 1376 1377 error = devfs_get_cdevpriv((void **)&d); 1378 if (error != 0) 1379 return (error); 1380 1381 /* 1382 * Refresh PID associated with this descriptor. 1383 */ 1384 BPFD_LOCK(d); 1385 BPF_PID_REFRESH(d, td); 1386 if (d->bd_state == BPF_WAITING) 1387 callout_stop(&d->bd_callout); 1388 d->bd_state = BPF_IDLE; 1389 BPFD_UNLOCK(d); 1390 1391 if (d->bd_locked == 1) { 1392 switch (cmd) { 1393 case BIOCGBLEN: 1394 case BIOCFLUSH: 1395 case BIOCGDLT: 1396 case BIOCGDLTLIST: 1397 #ifdef COMPAT_FREEBSD32 1398 case BIOCGDLTLIST32: 1399 #endif 1400 case BIOCGETIF: 1401 case BIOCGRTIMEOUT: 1402 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1403 case BIOCGRTIMEOUT32: 1404 #endif 1405 case BIOCGSTATS: 1406 case BIOCVERSION: 1407 case BIOCGRSIG: 1408 case BIOCGHDRCMPLT: 1409 case BIOCSTSTAMP: 1410 case BIOCFEEDBACK: 1411 case FIONREAD: 1412 case BIOCLOCK: 1413 case BIOCSRTIMEOUT: 1414 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1415 case BIOCSRTIMEOUT32: 1416 #endif 1417 case BIOCIMMEDIATE: 1418 case TIOCGPGRP: 1419 case BIOCROTZBUF: 1420 break; 1421 default: 1422 return (EPERM); 1423 } 1424 } 1425 #ifdef COMPAT_FREEBSD32 1426 /* 1427 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1428 * that it will get 32-bit packet headers. 1429 */ 1430 switch (cmd) { 1431 case BIOCSETF32: 1432 case BIOCSETFNR32: 1433 case BIOCSETWF32: 1434 case BIOCGDLTLIST32: 1435 case BIOCGRTIMEOUT32: 1436 case BIOCSRTIMEOUT32: 1437 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1438 BPFD_LOCK(d); 1439 d->bd_compat32 = 1; 1440 BPFD_UNLOCK(d); 1441 } 1442 } 1443 #endif 1444 1445 CURVNET_SET(TD_TO_VNET(td)); 1446 switch (cmd) { 1447 default: 1448 error = EINVAL; 1449 break; 1450 1451 /* 1452 * Check for read packet available. 1453 */ 1454 case FIONREAD: 1455 { 1456 int n; 1457 1458 BPFD_LOCK(d); 1459 n = d->bd_slen; 1460 while (d->bd_hbuf_in_use) 1461 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 1462 PRINET, "bd_hbuf", 0); 1463 if (d->bd_hbuf) 1464 n += d->bd_hlen; 1465 BPFD_UNLOCK(d); 1466 1467 *(int *)addr = n; 1468 break; 1469 } 1470 1471 /* 1472 * Get buffer len [for read()]. 1473 */ 1474 case BIOCGBLEN: 1475 BPFD_LOCK(d); 1476 *(u_int *)addr = d->bd_bufsize; 1477 BPFD_UNLOCK(d); 1478 break; 1479 1480 /* 1481 * Set buffer length. 1482 */ 1483 case BIOCSBLEN: 1484 error = bpf_ioctl_sblen(d, (u_int *)addr); 1485 break; 1486 1487 /* 1488 * Set link layer read filter. 1489 */ 1490 case BIOCSETF: 1491 case BIOCSETFNR: 1492 case BIOCSETWF: 1493 #ifdef COMPAT_FREEBSD32 1494 case BIOCSETF32: 1495 case BIOCSETFNR32: 1496 case BIOCSETWF32: 1497 #endif 1498 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1499 break; 1500 1501 /* 1502 * Flush read packet buffer. 1503 */ 1504 case BIOCFLUSH: 1505 BPFD_LOCK(d); 1506 reset_d(d); 1507 BPFD_UNLOCK(d); 1508 break; 1509 1510 /* 1511 * Put interface into promiscuous mode. 1512 */ 1513 case BIOCPROMISC: 1514 if (d->bd_bif == NULL) { 1515 /* 1516 * No interface attached yet. 1517 */ 1518 error = EINVAL; 1519 break; 1520 } 1521 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 break; 1527 1528 /* 1529 * Get current data link type. 1530 */ 1531 case BIOCGDLT: 1532 BPF_LOCK(); 1533 if (d->bd_bif == NULL) 1534 error = EINVAL; 1535 else 1536 *(u_int *)addr = d->bd_bif->bif_dlt; 1537 BPF_UNLOCK(); 1538 break; 1539 1540 /* 1541 * Get a list of supported data link types. 1542 */ 1543 #ifdef COMPAT_FREEBSD32 1544 case BIOCGDLTLIST32: 1545 { 1546 struct bpf_dltlist32 *list32; 1547 struct bpf_dltlist dltlist; 1548 1549 list32 = (struct bpf_dltlist32 *)addr; 1550 dltlist.bfl_len = list32->bfl_len; 1551 dltlist.bfl_list = PTRIN(list32->bfl_list); 1552 BPF_LOCK(); 1553 if (d->bd_bif == NULL) 1554 error = EINVAL; 1555 else { 1556 error = bpf_getdltlist(d, &dltlist); 1557 if (error == 0) 1558 list32->bfl_len = dltlist.bfl_len; 1559 } 1560 BPF_UNLOCK(); 1561 break; 1562 } 1563 #endif 1564 1565 case BIOCGDLTLIST: 1566 BPF_LOCK(); 1567 if (d->bd_bif == NULL) 1568 error = EINVAL; 1569 else 1570 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1571 BPF_UNLOCK(); 1572 break; 1573 1574 /* 1575 * Set data link type. 1576 */ 1577 case BIOCSDLT: 1578 BPF_LOCK(); 1579 if (d->bd_bif == NULL) 1580 error = EINVAL; 1581 else 1582 error = bpf_setdlt(d, *(u_int *)addr); 1583 BPF_UNLOCK(); 1584 break; 1585 1586 /* 1587 * Get interface name. 1588 */ 1589 case BIOCGETIF: 1590 BPF_LOCK(); 1591 if (d->bd_bif == NULL) 1592 error = EINVAL; 1593 else { 1594 struct ifnet *const ifp = d->bd_bif->bif_ifp; 1595 struct ifreq *const ifr = (struct ifreq *)addr; 1596 1597 strlcpy(ifr->ifr_name, ifp->if_xname, 1598 sizeof(ifr->ifr_name)); 1599 } 1600 BPF_UNLOCK(); 1601 break; 1602 1603 /* 1604 * Set interface. 1605 */ 1606 case BIOCSETIF: 1607 { 1608 int alloc_buf, size; 1609 1610 /* 1611 * Behavior here depends on the buffering model. If 1612 * we're using kernel memory buffers, then we can 1613 * allocate them here. If we're using zero-copy, 1614 * then the user process must have registered buffers 1615 * by the time we get here. 1616 */ 1617 alloc_buf = 0; 1618 BPFD_LOCK(d); 1619 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1620 d->bd_sbuf == NULL) 1621 alloc_buf = 1; 1622 BPFD_UNLOCK(d); 1623 if (alloc_buf) { 1624 size = d->bd_bufsize; 1625 error = bpf_buffer_ioctl_sblen(d, &size); 1626 if (error != 0) 1627 break; 1628 } 1629 BPF_LOCK(); 1630 error = bpf_setif(d, (struct ifreq *)addr); 1631 BPF_UNLOCK(); 1632 break; 1633 } 1634 1635 /* 1636 * Set read timeout. 1637 */ 1638 case BIOCSRTIMEOUT: 1639 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1640 case BIOCSRTIMEOUT32: 1641 #endif 1642 { 1643 struct timeval *tv = (struct timeval *)addr; 1644 #if defined(COMPAT_FREEBSD32) && !defined(__mips__) 1645 struct timeval32 *tv32; 1646 struct timeval tv64; 1647 1648 if (cmd == BIOCSRTIMEOUT32) { 1649 tv32 = (struct timeval32 *)addr; 1650 tv = &tv64; 1651 tv->tv_sec = tv32->tv_sec; 1652 tv->tv_usec = tv32->tv_usec; 1653 } else 1654 #endif 1655 tv = (struct timeval *)addr; 1656 1657 /* 1658 * Subtract 1 tick from tvtohz() since this isn't 1659 * a one-shot timer. 1660 */ 1661 if ((error = itimerfix(tv)) == 0) 1662 d->bd_rtout = tvtohz(tv) - 1; 1663 break; 1664 } 1665 1666 /* 1667 * Get read timeout. 1668 */ 1669 case BIOCGRTIMEOUT: 1670 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1671 case BIOCGRTIMEOUT32: 1672 #endif 1673 { 1674 struct timeval *tv; 1675 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1676 struct timeval32 *tv32; 1677 struct timeval tv64; 1678 1679 if (cmd == BIOCGRTIMEOUT32) 1680 tv = &tv64; 1681 else 1682 #endif 1683 tv = (struct timeval *)addr; 1684 1685 tv->tv_sec = d->bd_rtout / hz; 1686 tv->tv_usec = (d->bd_rtout % hz) * tick; 1687 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1688 if (cmd == BIOCGRTIMEOUT32) { 1689 tv32 = (struct timeval32 *)addr; 1690 tv32->tv_sec = tv->tv_sec; 1691 tv32->tv_usec = tv->tv_usec; 1692 } 1693 #endif 1694 1695 break; 1696 } 1697 1698 /* 1699 * Get packet stats. 1700 */ 1701 case BIOCGSTATS: 1702 { 1703 struct bpf_stat *bs = (struct bpf_stat *)addr; 1704 1705 /* XXXCSJP overflow */ 1706 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1707 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1708 break; 1709 } 1710 1711 /* 1712 * Set immediate mode. 1713 */ 1714 case BIOCIMMEDIATE: 1715 BPFD_LOCK(d); 1716 d->bd_immediate = *(u_int *)addr; 1717 BPFD_UNLOCK(d); 1718 break; 1719 1720 case BIOCVERSION: 1721 { 1722 struct bpf_version *bv = (struct bpf_version *)addr; 1723 1724 bv->bv_major = BPF_MAJOR_VERSION; 1725 bv->bv_minor = BPF_MINOR_VERSION; 1726 break; 1727 } 1728 1729 /* 1730 * Get "header already complete" flag 1731 */ 1732 case BIOCGHDRCMPLT: 1733 BPFD_LOCK(d); 1734 *(u_int *)addr = d->bd_hdrcmplt; 1735 BPFD_UNLOCK(d); 1736 break; 1737 1738 /* 1739 * Set "header already complete" flag 1740 */ 1741 case BIOCSHDRCMPLT: 1742 BPFD_LOCK(d); 1743 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1744 BPFD_UNLOCK(d); 1745 break; 1746 1747 /* 1748 * Get packet direction flag 1749 */ 1750 case BIOCGDIRECTION: 1751 BPFD_LOCK(d); 1752 *(u_int *)addr = d->bd_direction; 1753 BPFD_UNLOCK(d); 1754 break; 1755 1756 /* 1757 * Set packet direction flag 1758 */ 1759 case BIOCSDIRECTION: 1760 { 1761 u_int direction; 1762 1763 direction = *(u_int *)addr; 1764 switch (direction) { 1765 case BPF_D_IN: 1766 case BPF_D_INOUT: 1767 case BPF_D_OUT: 1768 BPFD_LOCK(d); 1769 d->bd_direction = direction; 1770 BPFD_UNLOCK(d); 1771 break; 1772 default: 1773 error = EINVAL; 1774 } 1775 } 1776 break; 1777 1778 /* 1779 * Get packet timestamp format and resolution. 1780 */ 1781 case BIOCGTSTAMP: 1782 BPFD_LOCK(d); 1783 *(u_int *)addr = d->bd_tstamp; 1784 BPFD_UNLOCK(d); 1785 break; 1786 1787 /* 1788 * Set packet timestamp format and resolution. 1789 */ 1790 case BIOCSTSTAMP: 1791 { 1792 u_int func; 1793 1794 func = *(u_int *)addr; 1795 if (BPF_T_VALID(func)) 1796 d->bd_tstamp = func; 1797 else 1798 error = EINVAL; 1799 } 1800 break; 1801 1802 case BIOCFEEDBACK: 1803 BPFD_LOCK(d); 1804 d->bd_feedback = *(u_int *)addr; 1805 BPFD_UNLOCK(d); 1806 break; 1807 1808 case BIOCLOCK: 1809 BPFD_LOCK(d); 1810 d->bd_locked = 1; 1811 BPFD_UNLOCK(d); 1812 break; 1813 1814 case FIONBIO: /* Non-blocking I/O */ 1815 break; 1816 1817 case FIOASYNC: /* Send signal on receive packets */ 1818 BPFD_LOCK(d); 1819 d->bd_async = *(int *)addr; 1820 BPFD_UNLOCK(d); 1821 break; 1822 1823 case FIOSETOWN: 1824 /* 1825 * XXX: Add some sort of locking here? 1826 * fsetown() can sleep. 1827 */ 1828 error = fsetown(*(int *)addr, &d->bd_sigio); 1829 break; 1830 1831 case FIOGETOWN: 1832 BPFD_LOCK(d); 1833 *(int *)addr = fgetown(&d->bd_sigio); 1834 BPFD_UNLOCK(d); 1835 break; 1836 1837 /* This is deprecated, FIOSETOWN should be used instead. */ 1838 case TIOCSPGRP: 1839 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1840 break; 1841 1842 /* This is deprecated, FIOGETOWN should be used instead. */ 1843 case TIOCGPGRP: 1844 *(int *)addr = -fgetown(&d->bd_sigio); 1845 break; 1846 1847 case BIOCSRSIG: /* Set receive signal */ 1848 { 1849 u_int sig; 1850 1851 sig = *(u_int *)addr; 1852 1853 if (sig >= NSIG) 1854 error = EINVAL; 1855 else { 1856 BPFD_LOCK(d); 1857 d->bd_sig = sig; 1858 BPFD_UNLOCK(d); 1859 } 1860 break; 1861 } 1862 case BIOCGRSIG: 1863 BPFD_LOCK(d); 1864 *(u_int *)addr = d->bd_sig; 1865 BPFD_UNLOCK(d); 1866 break; 1867 1868 case BIOCGETBUFMODE: 1869 BPFD_LOCK(d); 1870 *(u_int *)addr = d->bd_bufmode; 1871 BPFD_UNLOCK(d); 1872 break; 1873 1874 case BIOCSETBUFMODE: 1875 /* 1876 * Allow the buffering mode to be changed as long as we 1877 * haven't yet committed to a particular mode. Our 1878 * definition of commitment, for now, is whether or not a 1879 * buffer has been allocated or an interface attached, since 1880 * that's the point where things get tricky. 1881 */ 1882 switch (*(u_int *)addr) { 1883 case BPF_BUFMODE_BUFFER: 1884 break; 1885 1886 case BPF_BUFMODE_ZBUF: 1887 if (bpf_zerocopy_enable) 1888 break; 1889 /* FALLSTHROUGH */ 1890 1891 default: 1892 CURVNET_RESTORE(); 1893 return (EINVAL); 1894 } 1895 1896 BPFD_LOCK(d); 1897 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1898 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1899 BPFD_UNLOCK(d); 1900 CURVNET_RESTORE(); 1901 return (EBUSY); 1902 } 1903 d->bd_bufmode = *(u_int *)addr; 1904 BPFD_UNLOCK(d); 1905 break; 1906 1907 case BIOCGETZMAX: 1908 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1909 break; 1910 1911 case BIOCSETZBUF: 1912 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1913 break; 1914 1915 case BIOCROTZBUF: 1916 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1917 break; 1918 1919 case BIOCSETVLANPCP: 1920 { 1921 u_int pcp; 1922 1923 pcp = *(u_int *)addr; 1924 if (pcp > BPF_PRIO_MAX || pcp < 0) { 1925 error = EINVAL; 1926 break; 1927 } 1928 d->bd_pcp = pcp; 1929 break; 1930 } 1931 } 1932 CURVNET_RESTORE(); 1933 return (error); 1934 } 1935 1936 /* 1937 * Set d's packet filter program to fp. If this file already has a filter, 1938 * free it and replace it. Returns EINVAL for bogus requests. 1939 * 1940 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1941 * calls. 1942 */ 1943 static int 1944 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1945 { 1946 #ifdef COMPAT_FREEBSD32 1947 struct bpf_program fp_swab; 1948 struct bpf_program32 *fp32; 1949 #endif 1950 struct bpf_program_buffer *fcode; 1951 struct bpf_insn *filter; 1952 #ifdef BPF_JITTER 1953 bpf_jit_filter *jfunc; 1954 #endif 1955 size_t size; 1956 u_int flen; 1957 bool track_event; 1958 1959 #ifdef COMPAT_FREEBSD32 1960 switch (cmd) { 1961 case BIOCSETF32: 1962 case BIOCSETWF32: 1963 case BIOCSETFNR32: 1964 fp32 = (struct bpf_program32 *)fp; 1965 fp_swab.bf_len = fp32->bf_len; 1966 fp_swab.bf_insns = 1967 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1968 fp = &fp_swab; 1969 switch (cmd) { 1970 case BIOCSETF32: 1971 cmd = BIOCSETF; 1972 break; 1973 case BIOCSETWF32: 1974 cmd = BIOCSETWF; 1975 break; 1976 } 1977 break; 1978 } 1979 #endif 1980 1981 filter = NULL; 1982 #ifdef BPF_JITTER 1983 jfunc = NULL; 1984 #endif 1985 /* 1986 * Check new filter validness before acquiring any locks. 1987 * Allocate memory for new filter, if needed. 1988 */ 1989 flen = fp->bf_len; 1990 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1991 return (EINVAL); 1992 size = flen * sizeof(*fp->bf_insns); 1993 if (size > 0) { 1994 /* We're setting up new filter. Copy and check actual data. */ 1995 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1996 filter = (struct bpf_insn *)fcode->buffer; 1997 if (copyin(fp->bf_insns, filter, size) != 0 || 1998 !bpf_validate(filter, flen)) { 1999 free(fcode, M_BPF); 2000 return (EINVAL); 2001 } 2002 #ifdef BPF_JITTER 2003 if (cmd != BIOCSETWF) { 2004 /* 2005 * Filter is copied inside fcode and is 2006 * perfectly valid. 2007 */ 2008 jfunc = bpf_jitter(filter, flen); 2009 } 2010 #endif 2011 } 2012 2013 track_event = false; 2014 fcode = NULL; 2015 2016 BPF_LOCK(); 2017 BPFD_LOCK(d); 2018 /* Set up new filter. */ 2019 if (cmd == BIOCSETWF) { 2020 if (d->bd_wfilter != NULL) { 2021 fcode = __containerof((void *)d->bd_wfilter, 2022 struct bpf_program_buffer, buffer); 2023 #ifdef BPF_JITTER 2024 fcode->func = NULL; 2025 #endif 2026 } 2027 d->bd_wfilter = filter; 2028 } else { 2029 if (d->bd_rfilter != NULL) { 2030 fcode = __containerof((void *)d->bd_rfilter, 2031 struct bpf_program_buffer, buffer); 2032 #ifdef BPF_JITTER 2033 fcode->func = d->bd_bfilter; 2034 #endif 2035 } 2036 d->bd_rfilter = filter; 2037 #ifdef BPF_JITTER 2038 d->bd_bfilter = jfunc; 2039 #endif 2040 if (cmd == BIOCSETF) 2041 reset_d(d); 2042 2043 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 2044 /* 2045 * Filter can be set several times without 2046 * specifying interface. In this case just mark d 2047 * as reader. 2048 */ 2049 d->bd_writer = 0; 2050 if (d->bd_bif != NULL) { 2051 /* 2052 * Remove descriptor from writers-only list 2053 * and add it to active readers list. 2054 */ 2055 CK_LIST_REMOVE(d, bd_next); 2056 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 2057 d, bd_next); 2058 CTR2(KTR_NET, 2059 "%s: upgrade required by pid %d", 2060 __func__, d->bd_pid); 2061 track_event = true; 2062 } 2063 } 2064 } 2065 BPFD_UNLOCK(d); 2066 2067 if (fcode != NULL) 2068 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 2069 2070 if (track_event) 2071 EVENTHANDLER_INVOKE(bpf_track, 2072 d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); 2073 2074 BPF_UNLOCK(); 2075 return (0); 2076 } 2077 2078 /* 2079 * Detach a file from its current interface (if attached at all) and attach 2080 * to the interface indicated by the name stored in ifr. 2081 * Return an errno or 0. 2082 */ 2083 static int 2084 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 2085 { 2086 struct bpf_if *bp; 2087 struct ifnet *theywant; 2088 2089 BPF_LOCK_ASSERT(); 2090 2091 theywant = ifunit(ifr->ifr_name); 2092 if (theywant == NULL || theywant->if_bpf == NULL) 2093 return (ENXIO); 2094 2095 bp = theywant->if_bpf; 2096 /* 2097 * At this point, we expect the buffer is already allocated. If not, 2098 * return an error. 2099 */ 2100 switch (d->bd_bufmode) { 2101 case BPF_BUFMODE_BUFFER: 2102 case BPF_BUFMODE_ZBUF: 2103 if (d->bd_sbuf == NULL) 2104 return (EINVAL); 2105 break; 2106 2107 default: 2108 panic("bpf_setif: bufmode %d", d->bd_bufmode); 2109 } 2110 if (bp != d->bd_bif) 2111 bpf_attachd(d, bp); 2112 else { 2113 BPFD_LOCK(d); 2114 reset_d(d); 2115 BPFD_UNLOCK(d); 2116 } 2117 return (0); 2118 } 2119 2120 /* 2121 * Support for select() and poll() system calls 2122 * 2123 * Return true iff the specific operation will not block indefinitely. 2124 * Otherwise, return false but make a note that a selwakeup() must be done. 2125 */ 2126 static int 2127 bpfpoll(struct cdev *dev, int events, struct thread *td) 2128 { 2129 struct bpf_d *d; 2130 int revents; 2131 2132 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2133 return (events & 2134 (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); 2135 2136 /* 2137 * Refresh PID associated with this descriptor. 2138 */ 2139 revents = events & (POLLOUT | POLLWRNORM); 2140 BPFD_LOCK(d); 2141 BPF_PID_REFRESH(d, td); 2142 if (events & (POLLIN | POLLRDNORM)) { 2143 if (bpf_ready(d)) 2144 revents |= events & (POLLIN | POLLRDNORM); 2145 else { 2146 selrecord(td, &d->bd_sel); 2147 /* Start the read timeout if necessary. */ 2148 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2149 callout_reset(&d->bd_callout, d->bd_rtout, 2150 bpf_timed_out, d); 2151 d->bd_state = BPF_WAITING; 2152 } 2153 } 2154 } 2155 BPFD_UNLOCK(d); 2156 return (revents); 2157 } 2158 2159 /* 2160 * Support for kevent() system call. Register EVFILT_READ filters and 2161 * reject all others. 2162 */ 2163 int 2164 bpfkqfilter(struct cdev *dev, struct knote *kn) 2165 { 2166 struct bpf_d *d; 2167 2168 if (devfs_get_cdevpriv((void **)&d) != 0) 2169 return (1); 2170 2171 switch (kn->kn_filter) { 2172 case EVFILT_READ: 2173 kn->kn_fop = &bpfread_filtops; 2174 break; 2175 2176 case EVFILT_WRITE: 2177 kn->kn_fop = &bpfwrite_filtops; 2178 break; 2179 2180 default: 2181 return (1); 2182 } 2183 2184 /* 2185 * Refresh PID associated with this descriptor. 2186 */ 2187 BPFD_LOCK(d); 2188 BPF_PID_REFRESH_CUR(d); 2189 kn->kn_hook = d; 2190 knlist_add(&d->bd_sel.si_note, kn, 1); 2191 BPFD_UNLOCK(d); 2192 2193 return (0); 2194 } 2195 2196 static void 2197 filt_bpfdetach(struct knote *kn) 2198 { 2199 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2200 2201 knlist_remove(&d->bd_sel.si_note, kn, 0); 2202 } 2203 2204 static int 2205 filt_bpfread(struct knote *kn, long hint) 2206 { 2207 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2208 int ready; 2209 2210 BPFD_LOCK_ASSERT(d); 2211 ready = bpf_ready(d); 2212 if (ready) { 2213 kn->kn_data = d->bd_slen; 2214 /* 2215 * Ignore the hold buffer if it is being copied to user space. 2216 */ 2217 if (!d->bd_hbuf_in_use && d->bd_hbuf) 2218 kn->kn_data += d->bd_hlen; 2219 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2220 callout_reset(&d->bd_callout, d->bd_rtout, 2221 bpf_timed_out, d); 2222 d->bd_state = BPF_WAITING; 2223 } 2224 2225 return (ready); 2226 } 2227 2228 static int 2229 filt_bpfwrite(struct knote *kn, long hint) 2230 { 2231 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2232 BPFD_LOCK_ASSERT(d); 2233 2234 kn->kn_data = d->bd_bif->bif_ifp->if_mtu; 2235 2236 return (1); 2237 } 2238 2239 #define BPF_TSTAMP_NONE 0 2240 #define BPF_TSTAMP_FAST 1 2241 #define BPF_TSTAMP_NORMAL 2 2242 #define BPF_TSTAMP_EXTERN 3 2243 2244 static int 2245 bpf_ts_quality(int tstype) 2246 { 2247 2248 if (tstype == BPF_T_NONE) 2249 return (BPF_TSTAMP_NONE); 2250 if ((tstype & BPF_T_FAST) != 0) 2251 return (BPF_TSTAMP_FAST); 2252 2253 return (BPF_TSTAMP_NORMAL); 2254 } 2255 2256 static int 2257 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2258 { 2259 struct m_tag *tag; 2260 int quality; 2261 2262 quality = bpf_ts_quality(tstype); 2263 if (quality == BPF_TSTAMP_NONE) 2264 return (quality); 2265 2266 if (m != NULL) { 2267 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2268 if (tag != NULL) { 2269 *bt = *(struct bintime *)(tag + 1); 2270 return (BPF_TSTAMP_EXTERN); 2271 } 2272 } 2273 if (quality == BPF_TSTAMP_NORMAL) 2274 binuptime(bt); 2275 else 2276 getbinuptime(bt); 2277 2278 return (quality); 2279 } 2280 2281 /* 2282 * Incoming linkage from device drivers. Process the packet pkt, of length 2283 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2284 * by each process' filter, and if accepted, stashed into the corresponding 2285 * buffer. 2286 */ 2287 void 2288 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2289 { 2290 struct epoch_tracker et; 2291 struct bintime bt; 2292 struct bpf_d *d; 2293 #ifdef BPF_JITTER 2294 bpf_jit_filter *bf; 2295 #endif 2296 u_int slen; 2297 int gottime; 2298 2299 gottime = BPF_TSTAMP_NONE; 2300 NET_EPOCH_ENTER(et); 2301 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2302 counter_u64_add(d->bd_rcount, 1); 2303 /* 2304 * NB: We dont call BPF_CHECK_DIRECTION() here since there 2305 * is no way for the caller to indiciate to us whether this 2306 * packet is inbound or outbound. In the bpf_mtap() routines, 2307 * we use the interface pointers on the mbuf to figure it out. 2308 */ 2309 #ifdef BPF_JITTER 2310 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2311 if (bf != NULL) 2312 slen = (*(bf->func))(pkt, pktlen, pktlen); 2313 else 2314 #endif 2315 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2316 if (slen != 0) { 2317 /* 2318 * Filter matches. Let's to acquire write lock. 2319 */ 2320 BPFD_LOCK(d); 2321 counter_u64_add(d->bd_fcount, 1); 2322 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2323 gottime = bpf_gettime(&bt, d->bd_tstamp, 2324 NULL); 2325 #ifdef MAC 2326 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2327 #endif 2328 catchpacket(d, pkt, pktlen, slen, 2329 bpf_append_bytes, &bt); 2330 BPFD_UNLOCK(d); 2331 } 2332 } 2333 NET_EPOCH_EXIT(et); 2334 } 2335 2336 #define BPF_CHECK_DIRECTION(d, r, i) \ 2337 (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ 2338 ((d)->bd_direction == BPF_D_OUT && (r) == (i))) 2339 2340 /* 2341 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2342 * Locking model is explained in bpf_tap(). 2343 */ 2344 void 2345 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2346 { 2347 struct epoch_tracker et; 2348 struct bintime bt; 2349 struct bpf_d *d; 2350 #ifdef BPF_JITTER 2351 bpf_jit_filter *bf; 2352 #endif 2353 u_int pktlen, slen; 2354 int gottime; 2355 2356 /* Skip outgoing duplicate packets. */ 2357 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2358 m->m_flags &= ~M_PROMISC; 2359 return; 2360 } 2361 2362 pktlen = m_length(m, NULL); 2363 gottime = BPF_TSTAMP_NONE; 2364 2365 NET_EPOCH_ENTER(et); 2366 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2367 if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) 2368 continue; 2369 counter_u64_add(d->bd_rcount, 1); 2370 #ifdef BPF_JITTER 2371 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2372 /* XXX We cannot handle multiple mbufs. */ 2373 if (bf != NULL && m->m_next == NULL) 2374 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2375 pktlen); 2376 else 2377 #endif 2378 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2379 if (slen != 0) { 2380 BPFD_LOCK(d); 2381 2382 counter_u64_add(d->bd_fcount, 1); 2383 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2384 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2385 #ifdef MAC 2386 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2387 #endif 2388 catchpacket(d, (u_char *)m, pktlen, slen, 2389 bpf_append_mbuf, &bt); 2390 BPFD_UNLOCK(d); 2391 } 2392 } 2393 NET_EPOCH_EXIT(et); 2394 } 2395 2396 /* 2397 * Incoming linkage from device drivers, when packet is in 2398 * an mbuf chain and to be prepended by a contiguous header. 2399 */ 2400 void 2401 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2402 { 2403 struct epoch_tracker et; 2404 struct bintime bt; 2405 struct mbuf mb; 2406 struct bpf_d *d; 2407 u_int pktlen, slen; 2408 int gottime; 2409 2410 /* Skip outgoing duplicate packets. */ 2411 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2412 m->m_flags &= ~M_PROMISC; 2413 return; 2414 } 2415 2416 pktlen = m_length(m, NULL); 2417 /* 2418 * Craft on-stack mbuf suitable for passing to bpf_filter. 2419 * Note that we cut corners here; we only setup what's 2420 * absolutely needed--this mbuf should never go anywhere else. 2421 */ 2422 mb.m_flags = 0; 2423 mb.m_next = m; 2424 mb.m_data = data; 2425 mb.m_len = dlen; 2426 pktlen += dlen; 2427 2428 gottime = BPF_TSTAMP_NONE; 2429 2430 NET_EPOCH_ENTER(et); 2431 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2432 if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) 2433 continue; 2434 counter_u64_add(d->bd_rcount, 1); 2435 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2436 if (slen != 0) { 2437 BPFD_LOCK(d); 2438 2439 counter_u64_add(d->bd_fcount, 1); 2440 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2441 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2442 #ifdef MAC 2443 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 2444 #endif 2445 catchpacket(d, (u_char *)&mb, pktlen, slen, 2446 bpf_append_mbuf, &bt); 2447 BPFD_UNLOCK(d); 2448 } 2449 } 2450 NET_EPOCH_EXIT(et); 2451 } 2452 2453 #undef BPF_CHECK_DIRECTION 2454 #undef BPF_TSTAMP_NONE 2455 #undef BPF_TSTAMP_FAST 2456 #undef BPF_TSTAMP_NORMAL 2457 #undef BPF_TSTAMP_EXTERN 2458 2459 static int 2460 bpf_hdrlen(struct bpf_d *d) 2461 { 2462 int hdrlen; 2463 2464 hdrlen = d->bd_bif->bif_hdrlen; 2465 #ifndef BURN_BRIDGES 2466 if (d->bd_tstamp == BPF_T_NONE || 2467 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2468 #ifdef COMPAT_FREEBSD32 2469 if (d->bd_compat32) 2470 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2471 else 2472 #endif 2473 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2474 else 2475 #endif 2476 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2477 #ifdef COMPAT_FREEBSD32 2478 if (d->bd_compat32) 2479 hdrlen = BPF_WORDALIGN32(hdrlen); 2480 else 2481 #endif 2482 hdrlen = BPF_WORDALIGN(hdrlen); 2483 2484 return (hdrlen - d->bd_bif->bif_hdrlen); 2485 } 2486 2487 static void 2488 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2489 { 2490 struct bintime bt2, boottimebin; 2491 struct timeval tsm; 2492 struct timespec tsn; 2493 2494 if ((tstype & BPF_T_MONOTONIC) == 0) { 2495 bt2 = *bt; 2496 getboottimebin(&boottimebin); 2497 bintime_add(&bt2, &boottimebin); 2498 bt = &bt2; 2499 } 2500 switch (BPF_T_FORMAT(tstype)) { 2501 case BPF_T_MICROTIME: 2502 bintime2timeval(bt, &tsm); 2503 ts->bt_sec = tsm.tv_sec; 2504 ts->bt_frac = tsm.tv_usec; 2505 break; 2506 case BPF_T_NANOTIME: 2507 bintime2timespec(bt, &tsn); 2508 ts->bt_sec = tsn.tv_sec; 2509 ts->bt_frac = tsn.tv_nsec; 2510 break; 2511 case BPF_T_BINTIME: 2512 ts->bt_sec = bt->sec; 2513 ts->bt_frac = bt->frac; 2514 break; 2515 } 2516 } 2517 2518 /* 2519 * Move the packet data from interface memory (pkt) into the 2520 * store buffer. "cpfn" is the routine called to do the actual data 2521 * transfer. bcopy is passed in to copy contiguous chunks, while 2522 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2523 * pkt is really an mbuf. 2524 */ 2525 static void 2526 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2527 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2528 struct bintime *bt) 2529 { 2530 struct bpf_xhdr hdr; 2531 #ifndef BURN_BRIDGES 2532 struct bpf_hdr hdr_old; 2533 #ifdef COMPAT_FREEBSD32 2534 struct bpf_hdr32 hdr32_old; 2535 #endif 2536 #endif 2537 int caplen, curlen, hdrlen, totlen; 2538 int do_wakeup = 0; 2539 int do_timestamp; 2540 int tstype; 2541 2542 BPFD_LOCK_ASSERT(d); 2543 if (d->bd_bif == NULL) { 2544 /* Descriptor was detached in concurrent thread */ 2545 counter_u64_add(d->bd_dcount, 1); 2546 return; 2547 } 2548 2549 /* 2550 * Detect whether user space has released a buffer back to us, and if 2551 * so, move it from being a hold buffer to a free buffer. This may 2552 * not be the best place to do it (for example, we might only want to 2553 * run this check if we need the space), but for now it's a reliable 2554 * spot to do it. 2555 */ 2556 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2557 d->bd_fbuf = d->bd_hbuf; 2558 d->bd_hbuf = NULL; 2559 d->bd_hlen = 0; 2560 bpf_buf_reclaimed(d); 2561 } 2562 2563 /* 2564 * Figure out how many bytes to move. If the packet is 2565 * greater or equal to the snapshot length, transfer that 2566 * much. Otherwise, transfer the whole packet (unless 2567 * we hit the buffer size limit). 2568 */ 2569 hdrlen = bpf_hdrlen(d); 2570 totlen = hdrlen + min(snaplen, pktlen); 2571 if (totlen > d->bd_bufsize) 2572 totlen = d->bd_bufsize; 2573 2574 /* 2575 * Round up the end of the previous packet to the next longword. 2576 * 2577 * Drop the packet if there's no room and no hope of room 2578 * If the packet would overflow the storage buffer or the storage 2579 * buffer is considered immutable by the buffer model, try to rotate 2580 * the buffer and wakeup pending processes. 2581 */ 2582 #ifdef COMPAT_FREEBSD32 2583 if (d->bd_compat32) 2584 curlen = BPF_WORDALIGN32(d->bd_slen); 2585 else 2586 #endif 2587 curlen = BPF_WORDALIGN(d->bd_slen); 2588 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2589 if (d->bd_fbuf == NULL) { 2590 /* 2591 * There's no room in the store buffer, and no 2592 * prospect of room, so drop the packet. Notify the 2593 * buffer model. 2594 */ 2595 bpf_buffull(d); 2596 counter_u64_add(d->bd_dcount, 1); 2597 return; 2598 } 2599 KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); 2600 ROTATE_BUFFERS(d); 2601 do_wakeup = 1; 2602 curlen = 0; 2603 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 2604 /* 2605 * Immediate mode is set, or the read timeout has already 2606 * expired during a select call. A packet arrived, so the 2607 * reader should be woken up. 2608 */ 2609 do_wakeup = 1; 2610 caplen = totlen - hdrlen; 2611 tstype = d->bd_tstamp; 2612 do_timestamp = tstype != BPF_T_NONE; 2613 #ifndef BURN_BRIDGES 2614 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2615 struct bpf_ts ts; 2616 if (do_timestamp) 2617 bpf_bintime2ts(bt, &ts, tstype); 2618 #ifdef COMPAT_FREEBSD32 2619 if (d->bd_compat32) { 2620 bzero(&hdr32_old, sizeof(hdr32_old)); 2621 if (do_timestamp) { 2622 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2623 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2624 } 2625 hdr32_old.bh_datalen = pktlen; 2626 hdr32_old.bh_hdrlen = hdrlen; 2627 hdr32_old.bh_caplen = caplen; 2628 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2629 sizeof(hdr32_old)); 2630 goto copy; 2631 } 2632 #endif 2633 bzero(&hdr_old, sizeof(hdr_old)); 2634 if (do_timestamp) { 2635 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2636 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2637 } 2638 hdr_old.bh_datalen = pktlen; 2639 hdr_old.bh_hdrlen = hdrlen; 2640 hdr_old.bh_caplen = caplen; 2641 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2642 sizeof(hdr_old)); 2643 goto copy; 2644 } 2645 #endif 2646 2647 /* 2648 * Append the bpf header. Note we append the actual header size, but 2649 * move forward the length of the header plus padding. 2650 */ 2651 bzero(&hdr, sizeof(hdr)); 2652 if (do_timestamp) 2653 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2654 hdr.bh_datalen = pktlen; 2655 hdr.bh_hdrlen = hdrlen; 2656 hdr.bh_caplen = caplen; 2657 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2658 2659 /* 2660 * Copy the packet data into the store buffer and update its length. 2661 */ 2662 #ifndef BURN_BRIDGES 2663 copy: 2664 #endif 2665 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2666 d->bd_slen = curlen + totlen; 2667 2668 if (do_wakeup) 2669 bpf_wakeup(d); 2670 } 2671 2672 /* 2673 * Free buffers currently in use by a descriptor. 2674 * Called on close. 2675 */ 2676 static void 2677 bpfd_free(epoch_context_t ctx) 2678 { 2679 struct bpf_d *d; 2680 struct bpf_program_buffer *p; 2681 2682 /* 2683 * We don't need to lock out interrupts since this descriptor has 2684 * been detached from its interface and it yet hasn't been marked 2685 * free. 2686 */ 2687 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2688 bpf_free(d); 2689 if (d->bd_rfilter != NULL) { 2690 p = __containerof((void *)d->bd_rfilter, 2691 struct bpf_program_buffer, buffer); 2692 #ifdef BPF_JITTER 2693 p->func = d->bd_bfilter; 2694 #endif 2695 bpf_program_buffer_free(&p->epoch_ctx); 2696 } 2697 if (d->bd_wfilter != NULL) { 2698 p = __containerof((void *)d->bd_wfilter, 2699 struct bpf_program_buffer, buffer); 2700 #ifdef BPF_JITTER 2701 p->func = NULL; 2702 #endif 2703 bpf_program_buffer_free(&p->epoch_ctx); 2704 } 2705 2706 mtx_destroy(&d->bd_lock); 2707 counter_u64_free(d->bd_rcount); 2708 counter_u64_free(d->bd_dcount); 2709 counter_u64_free(d->bd_fcount); 2710 counter_u64_free(d->bd_wcount); 2711 counter_u64_free(d->bd_wfcount); 2712 counter_u64_free(d->bd_wdcount); 2713 counter_u64_free(d->bd_zcopy); 2714 free(d, M_BPF); 2715 } 2716 2717 /* 2718 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 2719 * fixed size of the link header (variable length headers not yet supported). 2720 */ 2721 void 2722 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2723 { 2724 2725 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 2726 } 2727 2728 /* 2729 * Attach an interface to bpf. ifp is a pointer to the structure 2730 * defining the interface to be attached, dlt is the link layer type, 2731 * and hdrlen is the fixed size of the link header (variable length 2732 * headers are not yet supporrted). 2733 */ 2734 void 2735 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, 2736 struct bpf_if **driverp) 2737 { 2738 struct bpf_if *bp; 2739 2740 KASSERT(*driverp == NULL, 2741 ("bpfattach2: driverp already initialized")); 2742 2743 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2744 2745 CK_LIST_INIT(&bp->bif_dlist); 2746 CK_LIST_INIT(&bp->bif_wlist); 2747 bp->bif_ifp = ifp; 2748 bp->bif_dlt = dlt; 2749 bp->bif_hdrlen = hdrlen; 2750 bp->bif_bpf = driverp; 2751 bp->bif_refcnt = 1; 2752 *driverp = bp; 2753 /* 2754 * Reference ifnet pointer, so it won't freed until 2755 * we release it. 2756 */ 2757 if_ref(ifp); 2758 BPF_LOCK(); 2759 CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 2760 BPF_UNLOCK(); 2761 2762 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 2763 if_printf(ifp, "bpf attached\n"); 2764 } 2765 2766 #ifdef VIMAGE 2767 /* 2768 * When moving interfaces between vnet instances we need a way to 2769 * query the dlt and hdrlen before detach so we can re-attch the if_bpf 2770 * after the vmove. We unfortunately have no device driver infrastructure 2771 * to query the interface for these values after creation/attach, thus 2772 * add this as a workaround. 2773 */ 2774 int 2775 bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) 2776 { 2777 2778 if (bp == NULL) 2779 return (ENXIO); 2780 if (bif_dlt == NULL && bif_hdrlen == NULL) 2781 return (0); 2782 2783 if (bif_dlt != NULL) 2784 *bif_dlt = bp->bif_dlt; 2785 if (bif_hdrlen != NULL) 2786 *bif_hdrlen = bp->bif_hdrlen; 2787 2788 return (0); 2789 } 2790 #endif 2791 2792 /* 2793 * Detach bpf from an interface. This involves detaching each descriptor 2794 * associated with the interface. Notify each descriptor as it's detached 2795 * so that any sleepers wake up and get ENXIO. 2796 */ 2797 void 2798 bpfdetach(struct ifnet *ifp) 2799 { 2800 struct bpf_if *bp, *bp_temp; 2801 struct bpf_d *d; 2802 2803 BPF_LOCK(); 2804 /* Find all bpf_if struct's which reference ifp and detach them. */ 2805 CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { 2806 if (ifp != bp->bif_ifp) 2807 continue; 2808 2809 CK_LIST_REMOVE(bp, bif_next); 2810 *bp->bif_bpf = (struct bpf_if *)&dead_bpf_if; 2811 2812 CTR4(KTR_NET, 2813 "%s: sheduling free for encap %d (%p) for if %p", 2814 __func__, bp->bif_dlt, bp, ifp); 2815 2816 /* Detach common descriptors */ 2817 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2818 bpf_detachd_locked(d, true); 2819 } 2820 2821 /* Detach writer-only descriptors */ 2822 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2823 bpf_detachd_locked(d, true); 2824 } 2825 bpfif_rele(bp); 2826 } 2827 BPF_UNLOCK(); 2828 } 2829 2830 /* 2831 * Get a list of available data link type of the interface. 2832 */ 2833 static int 2834 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2835 { 2836 struct ifnet *ifp; 2837 struct bpf_if *bp; 2838 u_int *lst; 2839 int error, n, n1; 2840 2841 BPF_LOCK_ASSERT(); 2842 2843 ifp = d->bd_bif->bif_ifp; 2844 n1 = 0; 2845 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2846 if (bp->bif_ifp == ifp) 2847 n1++; 2848 } 2849 if (bfl->bfl_list == NULL) { 2850 bfl->bfl_len = n1; 2851 return (0); 2852 } 2853 if (n1 > bfl->bfl_len) 2854 return (ENOMEM); 2855 2856 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2857 n = 0; 2858 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2859 if (bp->bif_ifp != ifp) 2860 continue; 2861 lst[n++] = bp->bif_dlt; 2862 } 2863 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2864 free(lst, M_TEMP); 2865 bfl->bfl_len = n; 2866 return (error); 2867 } 2868 2869 /* 2870 * Set the data link type of a BPF instance. 2871 */ 2872 static int 2873 bpf_setdlt(struct bpf_d *d, u_int dlt) 2874 { 2875 int error, opromisc; 2876 struct ifnet *ifp; 2877 struct bpf_if *bp; 2878 2879 BPF_LOCK_ASSERT(); 2880 MPASS(d->bd_bif != NULL); 2881 2882 /* 2883 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2884 * changed while we hold global lock. 2885 */ 2886 if (d->bd_bif->bif_dlt == dlt) 2887 return (0); 2888 2889 ifp = d->bd_bif->bif_ifp; 2890 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2891 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2892 break; 2893 } 2894 if (bp == NULL) 2895 return (EINVAL); 2896 2897 opromisc = d->bd_promisc; 2898 bpf_attachd(d, bp); 2899 if (opromisc) { 2900 error = ifpromisc(bp->bif_ifp, 1); 2901 if (error) 2902 if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", 2903 __func__, error); 2904 else 2905 d->bd_promisc = 1; 2906 } 2907 return (0); 2908 } 2909 2910 static void 2911 bpf_drvinit(void *unused) 2912 { 2913 struct cdev *dev; 2914 2915 sx_init(&bpf_sx, "bpf global lock"); 2916 CK_LIST_INIT(&bpf_iflist); 2917 2918 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2919 /* For compatibility */ 2920 make_dev_alias(dev, "bpf0"); 2921 } 2922 2923 /* 2924 * Zero out the various packet counters associated with all of the bpf 2925 * descriptors. At some point, we will probably want to get a bit more 2926 * granular and allow the user to specify descriptors to be zeroed. 2927 */ 2928 static void 2929 bpf_zero_counters(void) 2930 { 2931 struct bpf_if *bp; 2932 struct bpf_d *bd; 2933 2934 BPF_LOCK(); 2935 /* 2936 * We are protected by global lock here, interfaces and 2937 * descriptors can not be deleted while we hold it. 2938 */ 2939 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 2940 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2941 counter_u64_zero(bd->bd_rcount); 2942 counter_u64_zero(bd->bd_dcount); 2943 counter_u64_zero(bd->bd_fcount); 2944 counter_u64_zero(bd->bd_wcount); 2945 counter_u64_zero(bd->bd_wfcount); 2946 counter_u64_zero(bd->bd_zcopy); 2947 } 2948 } 2949 BPF_UNLOCK(); 2950 } 2951 2952 /* 2953 * Fill filter statistics 2954 */ 2955 static void 2956 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2957 { 2958 2959 BPF_LOCK_ASSERT(); 2960 bzero(d, sizeof(*d)); 2961 d->bd_structsize = sizeof(*d); 2962 d->bd_immediate = bd->bd_immediate; 2963 d->bd_promisc = bd->bd_promisc; 2964 d->bd_hdrcmplt = bd->bd_hdrcmplt; 2965 d->bd_direction = bd->bd_direction; 2966 d->bd_feedback = bd->bd_feedback; 2967 d->bd_async = bd->bd_async; 2968 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2969 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2970 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2971 d->bd_sig = bd->bd_sig; 2972 d->bd_slen = bd->bd_slen; 2973 d->bd_hlen = bd->bd_hlen; 2974 d->bd_bufsize = bd->bd_bufsize; 2975 d->bd_pid = bd->bd_pid; 2976 strlcpy(d->bd_ifname, 2977 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 2978 d->bd_locked = bd->bd_locked; 2979 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2980 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2981 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2982 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2983 d->bd_bufmode = bd->bd_bufmode; 2984 } 2985 2986 /* 2987 * Handle `netstat -B' stats request 2988 */ 2989 static int 2990 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2991 { 2992 static const struct xbpf_d zerostats; 2993 struct xbpf_d *xbdbuf, *xbd, tempstats; 2994 int index, error; 2995 struct bpf_if *bp; 2996 struct bpf_d *bd; 2997 2998 /* 2999 * XXX This is not technically correct. It is possible for non 3000 * privileged users to open bpf devices. It would make sense 3001 * if the users who opened the devices were able to retrieve 3002 * the statistics for them, too. 3003 */ 3004 error = priv_check(req->td, PRIV_NET_BPF); 3005 if (error) 3006 return (error); 3007 /* 3008 * Check to see if the user is requesting that the counters be 3009 * zeroed out. Explicitly check that the supplied data is zeroed, 3010 * as we aren't allowing the user to set the counters currently. 3011 */ 3012 if (req->newptr != NULL) { 3013 if (req->newlen != sizeof(tempstats)) 3014 return (EINVAL); 3015 memset(&tempstats, 0, sizeof(tempstats)); 3016 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 3017 if (error) 3018 return (error); 3019 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 3020 return (EINVAL); 3021 bpf_zero_counters(); 3022 return (0); 3023 } 3024 if (req->oldptr == NULL) 3025 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 3026 if (bpf_bpfd_cnt == 0) 3027 return (SYSCTL_OUT(req, 0, 0)); 3028 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 3029 BPF_LOCK(); 3030 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 3031 BPF_UNLOCK(); 3032 free(xbdbuf, M_BPF); 3033 return (ENOMEM); 3034 } 3035 index = 0; 3036 CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { 3037 /* Send writers-only first */ 3038 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 3039 xbd = &xbdbuf[index++]; 3040 bpfstats_fill_xbpf(xbd, bd); 3041 } 3042 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 3043 xbd = &xbdbuf[index++]; 3044 bpfstats_fill_xbpf(xbd, bd); 3045 } 3046 } 3047 BPF_UNLOCK(); 3048 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 3049 free(xbdbuf, M_BPF); 3050 return (error); 3051 } 3052 3053 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); 3054 3055 #else /* !DEV_BPF && !NETGRAPH_BPF */ 3056 3057 /* 3058 * NOP stubs to allow bpf-using drivers to load and function. 3059 * 3060 * A 'better' implementation would allow the core bpf functionality 3061 * to be loaded at runtime. 3062 */ 3063 3064 void 3065 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3066 { 3067 } 3068 3069 void 3070 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3071 { 3072 } 3073 3074 void 3075 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3076 { 3077 } 3078 3079 void 3080 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3081 { 3082 3083 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 3084 } 3085 3086 void 3087 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 3088 { 3089 3090 *driverp = (struct bpf_if *)&dead_bpf_if; 3091 } 3092 3093 void 3094 bpfdetach(struct ifnet *ifp) 3095 { 3096 } 3097 3098 u_int 3099 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3100 { 3101 return -1; /* "no filter" behaviour */ 3102 } 3103 3104 int 3105 bpf_validate(const struct bpf_insn *f, int len) 3106 { 3107 return 0; /* false */ 3108 } 3109 3110 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3111 3112 #ifdef DDB 3113 static void 3114 bpf_show_bpf_if(struct bpf_if *bpf_if) 3115 { 3116 3117 if (bpf_if == NULL) 3118 return; 3119 db_printf("%p:\n", bpf_if); 3120 #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); 3121 /* bif_ext.bif_next */ 3122 /* bif_ext.bif_dlist */ 3123 BPF_DB_PRINTF("%#x", bif_dlt); 3124 BPF_DB_PRINTF("%u", bif_hdrlen); 3125 /* bif_wlist */ 3126 BPF_DB_PRINTF("%p", bif_ifp); 3127 BPF_DB_PRINTF("%p", bif_bpf); 3128 BPF_DB_PRINTF("%u", bif_refcnt); 3129 } 3130 3131 DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) 3132 { 3133 3134 if (!have_addr) { 3135 db_printf("usage: show bpf_if <struct bpf_if *>\n"); 3136 return; 3137 } 3138 3139 bpf_show_bpf_if((struct bpf_if *)addr); 3140 } 3141 #endif 3142