1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * Copyright (c) 2019 Andrey V. Elsukov <ae@FreeBSD.org> 7 * 8 * This code is derived from the Stanford/CMU enet packet filter, 9 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 10 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 11 * Berkeley Laboratory. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38 #include <sys/cdefs.h> 39 #include "opt_bpf.h" 40 #include "opt_netgraph.h" 41 42 #include <sys/param.h> 43 #include <sys/conf.h> 44 #include <sys/fcntl.h> 45 #include <sys/jail.h> 46 #include <sys/ktr.h> 47 #include <sys/lock.h> 48 #include <sys/malloc.h> 49 #include <sys/mbuf.h> 50 #include <sys/mutex.h> 51 #include <sys/time.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/signalvar.h> 55 #include <sys/filio.h> 56 #include <sys/sockio.h> 57 #include <sys/ttycom.h> 58 #include <sys/uio.h> 59 #include <sys/sysent.h> 60 #include <sys/systm.h> 61 62 #include <sys/file.h> 63 #include <sys/poll.h> 64 #include <sys/proc.h> 65 66 #include <sys/socket.h> 67 68 #include <net/if.h> 69 #include <net/if_var.h> 70 #include <net/if_private.h> 71 #include <net/if_vlan_var.h> 72 #include <net/bpf.h> 73 #include <net/bpf_buffer.h> 74 #ifdef BPF_JITTER 75 #include <net/bpf_jitter.h> 76 #endif 77 #include <net/bpf_zerocopy.h> 78 #include <net/bpfdesc.h> 79 #include <net/vnet.h> 80 81 #include <sys/kernel.h> 82 #include <sys/sysctl.h> 83 84 #include <security/mac/mac_framework.h> 85 86 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 87 88 struct bpf_if { 89 struct bpfd_list bif_dlist; /* list of all interfaces */ 90 LIST_ENTRY(bpf_if) bif_next; /* descriptor list */ 91 u_int bif_dlt; /* link layer type */ 92 u_int bif_hdrlen; /* length of link header */ 93 volatile u_int bif_refcnt; 94 struct bpfd_list bif_wlist; /* writer-only list */ 95 const struct bif_methods *bif_methods; 96 void *bif_softc; 97 const char *bif_name; 98 struct epoch_context epoch_ctx; 99 }; 100 101 /* See bpf_peers_present() in bpf.h. */ 102 _Static_assert(offsetof(struct bpf_if, bif_dlist) == 0, 103 "bpf_if shall start with bif_dlist"); 104 105 static inline void 106 bif_attachd(struct bpf_if *bp) 107 { 108 if (bp->bif_methods->bif_attachd != NULL) 109 bp->bif_methods->bif_attachd(bp->bif_softc); 110 } 111 112 static inline void 113 bif_detachd(struct bpf_if *bp) 114 { 115 if (bp->bif_methods->bif_detachd != NULL) 116 bp->bif_methods->bif_detachd(bp->bif_softc); 117 } 118 119 static inline uint32_t 120 bif_wrsize(struct bpf_if *bp) 121 { 122 if (bp->bif_methods->bif_wrsize != NULL) 123 return (bp->bif_methods->bif_wrsize(bp->bif_softc)); 124 else 125 return (0); 126 } 127 128 static inline int 129 bif_promisc(struct bpf_if *bp, bool on) 130 { 131 if (bp->bif_methods->bif_promisc != NULL) 132 return (bp->bif_methods->bif_promisc(bp->bif_softc, on)); 133 else 134 return (0); 135 } 136 137 #ifdef MAC 138 static inline int 139 bif_mac_check_receive(struct bpf_if *bp, struct bpf_d *d) 140 { 141 if (bp->bif_methods->bif_mac_check_receive != NULL) 142 return (bp->bif_methods->bif_mac_check_receive(bp->bif_softc, 143 d)); 144 else 145 return (0); 146 } 147 #endif 148 149 /* 150 * XXXGL: Once we migrate to tapping KPI that would specify packet direction 151 * we no longer need bif_chkdir method. 152 */ 153 static inline bool 154 bpf_chkdir(struct bpf_d *d, struct mbuf *m) 155 { 156 return (d->bd_bif->bif_methods->bif_chkdir(d->bd_bif->bif_softc, m, 157 d->bd_direction)); 158 } 159 160 struct bpf_program_buffer { 161 struct epoch_context epoch_ctx; 162 #ifdef BPF_JITTER 163 bpf_jit_filter *func; 164 #endif 165 void *buffer[0]; 166 }; 167 168 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 169 170 #define PRINET 26 /* interruptible */ 171 #define BPF_PRIO_MAX 7 172 173 #define SIZEOF_BPF_HDR(type) \ 174 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 175 176 #ifdef COMPAT_FREEBSD32 177 #include <sys/mount.h> 178 #include <compat/freebsd32/freebsd32.h> 179 #define BPF_ALIGNMENT32 sizeof(int32_t) 180 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) 181 182 #ifndef BURN_BRIDGES 183 /* 184 * 32-bit version of structure prepended to each packet. We use this header 185 * instead of the standard one for 32-bit streams. We mark the a stream as 186 * 32-bit the first time we see a 32-bit compat ioctl request. 187 */ 188 struct bpf_hdr32 { 189 struct timeval32 bh_tstamp; /* time stamp */ 190 uint32_t bh_caplen; /* length of captured portion */ 191 uint32_t bh_datalen; /* original length of packet */ 192 uint16_t bh_hdrlen; /* length of bpf header (this struct 193 plus alignment padding) */ 194 }; 195 #endif 196 197 struct bpf_program32 { 198 u_int bf_len; 199 uint32_t bf_insns; 200 }; 201 202 struct bpf_dltlist32 { 203 u_int bfl_len; 204 u_int bfl_list; 205 }; 206 207 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 208 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 209 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 210 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 211 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 212 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 213 #endif 214 215 #define BPF_LOCK() sx_xlock(&bpf_sx) 216 #define BPF_UNLOCK() sx_xunlock(&bpf_sx) 217 #define BPF_LOCK_ASSERT() sx_assert(&bpf_sx, SA_XLOCKED) 218 /* 219 * bpf_iflist is a list of BPF interface structures, each corresponding to a 220 * specific DLT. The same network interface might have several BPF interface 221 * structures registered by different layers in the stack (i.e., 802.11 222 * frames, ethernet frames, etc). 223 */ 224 VNET_DEFINE_STATIC(LIST_HEAD(, bpf_if), bpf_iflist) = LIST_HEAD_INITIALIZER(); 225 #define V_bpf_iflist VNET(bpf_iflist) 226 static struct sx bpf_sx; /* bpf global lock */ 227 228 static void bpfif_ref(struct bpf_if *); 229 static void bpfif_rele(struct bpf_if *); 230 231 static void bpfd_ref(struct bpf_d *); 232 static void bpfd_rele(struct bpf_d *); 233 static int bpf_attachd(struct bpf_d *d, struct bpf_if *); 234 static void bpf_detachd(struct bpf_d *, bool); 235 static void bpfd_free(epoch_context_t); 236 static void bpf_timed_out(void *); 237 static __inline void 238 bpf_wakeup(struct bpf_d *); 239 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 240 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 241 struct bintime *); 242 static void reset_d(struct bpf_d *); 243 static int bpf_getiflist(struct bpf_iflist *); 244 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 245 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 246 static int bpf_setdlt(struct bpf_d *, u_int); 247 static void filt_bpfdetach(struct knote *); 248 static int filt_bpfread(struct knote *, long); 249 static int filt_bpfwrite(struct knote *, long); 250 static void bpf_drvinit(void *); 251 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 252 253 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 254 "bpf sysctl"); 255 int bpf_maxinsns = BPF_MAXINSNS; 256 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 257 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 258 static int bpf_zerocopy_enable = 0; 259 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 260 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 261 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, 262 CTLFLAG_VNET | CTLFLAG_MPSAFE | CTLFLAG_RW, 263 bpf_stats_sysctl, "bpf statistics portal"); 264 265 VNET_DEFINE_STATIC(int, bpf_optimize_writers) = 0; 266 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 267 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RWTUN, 268 &VNET_NAME(bpf_optimize_writers), 0, 269 "Do not send packets until BPF program is set"); 270 271 static d_open_t bpfopen; 272 static d_read_t bpfread; 273 static d_write_t bpfwrite; 274 static d_ioctl_t bpfioctl; 275 static d_poll_t bpfpoll; 276 static d_kqfilter_t bpfkqfilter; 277 278 static struct cdevsw bpf_cdevsw = { 279 .d_version = D_VERSION, 280 .d_open = bpfopen, 281 .d_read = bpfread, 282 .d_write = bpfwrite, 283 .d_ioctl = bpfioctl, 284 .d_poll = bpfpoll, 285 .d_name = "bpf", 286 .d_kqfilter = bpfkqfilter, 287 }; 288 289 static const struct filterops bpfread_filtops = { 290 .f_isfd = 1, 291 .f_detach = filt_bpfdetach, 292 .f_event = filt_bpfread, 293 .f_copy = knote_triv_copy, 294 }; 295 296 static const struct filterops bpfwrite_filtops = { 297 .f_isfd = 1, 298 .f_detach = filt_bpfdetach, 299 .f_event = filt_bpfwrite, 300 .f_copy = knote_triv_copy, 301 }; 302 303 /* 304 * LOCKING MODEL USED BY BPF 305 * 306 * Locks: 307 * 1) global lock (BPF_LOCK). Sx, used to protect some global counters, 308 * every bpf_iflist changes, serializes ioctl access to bpf descriptors. 309 * 2) Descriptor lock. Mutex, used to protect BPF buffers and various 310 * structure fields used by bpf_*tap* code. 311 * 312 * Lock order: global lock, then descriptor lock. 313 * 314 * There are several possible consumers: 315 * 316 * 1. The kernel registers interface pointer with bpfattach(). 317 * Each call allocates new bpf_if structure, references ifnet pointer 318 * and links bpf_if into bpf_iflist chain. This is protected with global 319 * lock. 320 * 321 * 2. An userland application uses ioctl() call to bpf_d descriptor. 322 * All such call are serialized with global lock. BPF filters can be 323 * changed, but pointer to old filter will be freed using NET_EPOCH_CALL(). 324 * Thus it should be safe for bpf_tap/bpf_mtap* code to do access to 325 * filter pointers, even if change will happen during bpf_tap execution. 326 * Destroying of bpf_d descriptor also is doing using NET_EPOCH_CALL(). 327 * 328 * 3. An userland application can write packets into bpf_d descriptor. 329 * There we need to be sure, that ifnet won't disappear during bpfwrite(). 330 * 331 * 4. The kernel invokes bpf_tap/bpf_mtap* functions. The access to 332 * bif_dlist is protected with net_epoch_preempt section. So, it should 333 * be safe to make access to bpf_d descriptor inside the section. 334 * 335 * 5. The kernel invokes bpfdetach() on interface destroying. All lists 336 * are modified with global lock held and actual free() is done using 337 * NET_EPOCH_CALL(). 338 */ 339 340 static void 341 bpfif_free(epoch_context_t ctx) 342 { 343 struct bpf_if *bp; 344 345 bp = __containerof(ctx, struct bpf_if, epoch_ctx); 346 free(bp, M_BPF); 347 } 348 349 static void 350 bpfif_ref(struct bpf_if *bp) 351 { 352 353 refcount_acquire(&bp->bif_refcnt); 354 } 355 356 static void 357 bpfif_rele(struct bpf_if *bp) 358 { 359 360 if (!refcount_release(&bp->bif_refcnt)) 361 return; 362 NET_EPOCH_CALL(bpfif_free, &bp->epoch_ctx); 363 } 364 365 static void 366 bpfd_ref(struct bpf_d *d) 367 { 368 369 refcount_acquire(&d->bd_refcnt); 370 } 371 372 static void 373 bpfd_rele(struct bpf_d *d) 374 { 375 376 if (!refcount_release(&d->bd_refcnt)) 377 return; 378 NET_EPOCH_CALL(bpfd_free, &d->epoch_ctx); 379 } 380 381 static struct bpf_program_buffer* 382 bpf_program_buffer_alloc(size_t size, int flags) 383 { 384 385 return (malloc(sizeof(struct bpf_program_buffer) + size, 386 M_BPF, flags)); 387 } 388 389 static void 390 bpf_program_buffer_free(epoch_context_t ctx) 391 { 392 struct bpf_program_buffer *ptr; 393 394 ptr = __containerof(ctx, struct bpf_program_buffer, epoch_ctx); 395 #ifdef BPF_JITTER 396 if (ptr->func != NULL) 397 bpf_destroy_jit_filter(ptr->func); 398 #endif 399 free(ptr, M_BPF); 400 } 401 402 /* 403 * Wrapper functions for various buffering methods. If the set of buffer 404 * modes expands, we will probably want to introduce a switch data structure 405 * similar to protosw, et. 406 */ 407 static void 408 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 409 u_int len) 410 { 411 412 BPFD_LOCK_ASSERT(d); 413 414 switch (d->bd_bufmode) { 415 case BPF_BUFMODE_BUFFER: 416 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 417 418 case BPF_BUFMODE_ZBUF: 419 counter_u64_add(d->bd_zcopy, 1); 420 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 421 422 default: 423 panic("bpf_buf_append_bytes"); 424 } 425 } 426 427 static void 428 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 429 u_int len) 430 { 431 432 BPFD_LOCK_ASSERT(d); 433 434 switch (d->bd_bufmode) { 435 case BPF_BUFMODE_BUFFER: 436 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 437 438 case BPF_BUFMODE_ZBUF: 439 counter_u64_add(d->bd_zcopy, 1); 440 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 441 442 default: 443 panic("bpf_buf_append_mbuf"); 444 } 445 } 446 447 /* 448 * This function gets called when the free buffer is re-assigned. 449 */ 450 static void 451 bpf_buf_reclaimed(struct bpf_d *d) 452 { 453 454 BPFD_LOCK_ASSERT(d); 455 456 switch (d->bd_bufmode) { 457 case BPF_BUFMODE_BUFFER: 458 return; 459 460 case BPF_BUFMODE_ZBUF: 461 bpf_zerocopy_buf_reclaimed(d); 462 return; 463 464 default: 465 panic("bpf_buf_reclaimed"); 466 } 467 } 468 469 /* 470 * If the buffer mechanism has a way to decide that a held buffer can be made 471 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 472 * returned if the buffer can be discarded, (0) is returned if it cannot. 473 */ 474 static int 475 bpf_canfreebuf(struct bpf_d *d) 476 { 477 478 BPFD_LOCK_ASSERT(d); 479 480 switch (d->bd_bufmode) { 481 case BPF_BUFMODE_ZBUF: 482 return (bpf_zerocopy_canfreebuf(d)); 483 } 484 return (0); 485 } 486 487 /* 488 * Allow the buffer model to indicate that the current store buffer is 489 * immutable, regardless of the appearance of space. Return (1) if the 490 * buffer is writable, and (0) if not. 491 */ 492 static int 493 bpf_canwritebuf(struct bpf_d *d) 494 { 495 BPFD_LOCK_ASSERT(d); 496 497 switch (d->bd_bufmode) { 498 case BPF_BUFMODE_ZBUF: 499 return (bpf_zerocopy_canwritebuf(d)); 500 } 501 return (1); 502 } 503 504 /* 505 * Notify buffer model that an attempt to write to the store buffer has 506 * resulted in a dropped packet, in which case the buffer may be considered 507 * full. 508 */ 509 static void 510 bpf_buffull(struct bpf_d *d) 511 { 512 513 BPFD_LOCK_ASSERT(d); 514 515 switch (d->bd_bufmode) { 516 case BPF_BUFMODE_ZBUF: 517 bpf_zerocopy_buffull(d); 518 break; 519 } 520 } 521 522 /* 523 * Notify the buffer model that a buffer has moved into the hold position. 524 */ 525 void 526 bpf_bufheld(struct bpf_d *d) 527 { 528 529 BPFD_LOCK_ASSERT(d); 530 531 switch (d->bd_bufmode) { 532 case BPF_BUFMODE_ZBUF: 533 bpf_zerocopy_bufheld(d); 534 break; 535 } 536 } 537 538 static void 539 bpf_free(struct bpf_d *d) 540 { 541 542 switch (d->bd_bufmode) { 543 case BPF_BUFMODE_BUFFER: 544 return (bpf_buffer_free(d)); 545 546 case BPF_BUFMODE_ZBUF: 547 return (bpf_zerocopy_free(d)); 548 549 default: 550 panic("bpf_buf_free"); 551 } 552 } 553 554 static int 555 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 556 { 557 558 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 559 return (EOPNOTSUPP); 560 return (bpf_buffer_uiomove(d, buf, len, uio)); 561 } 562 563 static int 564 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 565 { 566 567 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 568 return (EOPNOTSUPP); 569 return (bpf_buffer_ioctl_sblen(d, i)); 570 } 571 572 static int 573 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 574 { 575 576 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 577 return (EOPNOTSUPP); 578 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 579 } 580 581 static int 582 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 583 { 584 585 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 586 return (EOPNOTSUPP); 587 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 588 } 589 590 static int 591 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 592 { 593 594 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 595 return (EOPNOTSUPP); 596 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 597 } 598 599 /* 600 * Check if we need to upgrade our descriptor @d from write-only mode. 601 */ 602 static int 603 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 604 int flen) 605 { 606 int is_snap, need_upgrade; 607 608 /* 609 * Check if we've already upgraded or new filter is empty. 610 */ 611 if (d->bd_writer == 0 || fcode == NULL) 612 return (0); 613 614 need_upgrade = 0; 615 616 /* 617 * Check if cmd looks like snaplen setting from 618 * pcap_bpf.c:pcap_open_live(). 619 * Note we're not checking .k value here: 620 * while pcap_open_live() definitely sets to non-zero value, 621 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 622 * do not consider upgrading immediately 623 */ 624 if (cmd == BIOCSETF && flen == 1 && 625 fcode[0].code == (BPF_RET | BPF_K)) 626 is_snap = 1; 627 else 628 is_snap = 0; 629 630 if (is_snap == 0) { 631 /* 632 * We're setting first filter and it doesn't look like 633 * setting snaplen. We're probably using bpf directly. 634 * Upgrade immediately. 635 */ 636 need_upgrade = 1; 637 } else { 638 /* 639 * Do not require upgrade by first BIOCSETF 640 * (used to set snaplen) by pcap_open_live(). 641 */ 642 643 if (--d->bd_writer == 0) { 644 /* 645 * First snaplen filter has already 646 * been set. This is probably catch-all 647 * filter 648 */ 649 need_upgrade = 1; 650 } 651 } 652 653 CTR5(KTR_NET, 654 "%s: filter function set by pid %d, " 655 "bd_writer counter %d, snap %d upgrade %d", 656 __func__, d->bd_pid, d->bd_writer, 657 is_snap, need_upgrade); 658 659 return (need_upgrade); 660 } 661 662 /* 663 * Detach a file from its interface. 664 */ 665 static void 666 bpf_detachd(struct bpf_d *d, bool detached_ifp) 667 { 668 struct bpf_if *bp; 669 bool writer; 670 671 BPF_LOCK_ASSERT(); 672 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 673 674 /* Check if descriptor is attached */ 675 if ((bp = d->bd_bif) == NULL) 676 return; 677 678 BPFD_LOCK(d); 679 CK_LIST_REMOVE(d, bd_next); 680 writer = (d->bd_writer > 0); 681 if (detached_ifp) { 682 d->bd_bif = NULL; 683 /* 684 * Notify descriptor as it's detached, so that any 685 * sleepers wake up and get ENXIO. 686 */ 687 bpf_wakeup(d); 688 } 689 BPFD_UNLOCK(d); 690 691 if (!writer) 692 bif_detachd(bp); 693 694 if (d->bd_promisc && !detached_ifp) { 695 d->bd_promisc = 0; 696 (void)bif_promisc(bp, false); 697 } 698 699 bpfif_rele(bp); 700 } 701 702 /* 703 * Close the descriptor by detaching it from its interface, 704 * deallocating its buffers, and marking it free. 705 */ 706 static void 707 bpf_dtor(void *data) 708 { 709 struct bpf_d *d = data; 710 711 BPFD_LOCK(d); 712 if (d->bd_state == BPF_WAITING) 713 callout_stop(&d->bd_callout); 714 d->bd_state = BPF_IDLE; 715 BPFD_UNLOCK(d); 716 funsetown(&d->bd_sigio); 717 BPF_LOCK(); 718 bpf_detachd(d, false); 719 BPF_UNLOCK(); 720 #ifdef MAC 721 mac_bpfdesc_destroy(d); 722 #endif /* MAC */ 723 seldrain(&d->bd_sel); 724 knlist_destroy(&d->bd_sel.si_note); 725 callout_drain(&d->bd_callout); 726 bpfd_rele(d); 727 } 728 729 /* 730 * Open ethernet device. Returns ENXIO for illegal minor device number, 731 * EBUSY if file is open by another process. 732 */ 733 /* ARGSUSED */ 734 static int 735 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 736 { 737 struct bpf_d *d; 738 int error; 739 740 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 741 error = devfs_set_cdevpriv(d, bpf_dtor); 742 if (error != 0) { 743 free(d, M_BPF); 744 return (error); 745 } 746 747 /* Setup counters */ 748 d->bd_rcount = counter_u64_alloc(M_WAITOK); 749 d->bd_dcount = counter_u64_alloc(M_WAITOK); 750 d->bd_fcount = counter_u64_alloc(M_WAITOK); 751 d->bd_wcount = counter_u64_alloc(M_WAITOK); 752 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 753 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 754 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 755 756 /* 757 * For historical reasons, perform a one-time initialization call to 758 * the buffer routines, even though we're not yet committed to a 759 * particular buffer method. 760 */ 761 bpf_buffer_init(d); 762 if ((flags & FREAD) == 0) 763 d->bd_writer = 2; 764 d->bd_bufmode = BPF_BUFMODE_BUFFER; 765 d->bd_sig = SIGIO; 766 d->bd_direction = BPF_D_INOUT; 767 refcount_init(&d->bd_refcnt, 1); 768 BPF_PID_REFRESH(d, td); 769 #ifdef MAC 770 mac_bpfdesc_init(d); 771 mac_bpfdesc_create(td->td_ucred, d); 772 #endif 773 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 774 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 775 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 776 777 /* Disable VLAN pcp tagging. */ 778 d->bd_pcp = 0; 779 780 return (0); 781 } 782 783 /* 784 * bpfread - read next chunk of packets from buffers 785 */ 786 static int 787 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 788 { 789 struct bpf_d *d; 790 int error; 791 int non_block; 792 int timed_out; 793 794 error = devfs_get_cdevpriv((void **)&d); 795 if (error != 0) 796 return (error); 797 798 /* 799 * Restrict application to use a buffer the same size as 800 * as kernel buffers. 801 */ 802 if (uio->uio_resid != d->bd_bufsize) 803 return (EINVAL); 804 805 non_block = ((ioflag & O_NONBLOCK) != 0); 806 807 BPFD_LOCK(d); 808 BPF_PID_REFRESH_CUR(d); 809 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 810 BPFD_UNLOCK(d); 811 return (EOPNOTSUPP); 812 } 813 if (d->bd_state == BPF_WAITING) 814 callout_stop(&d->bd_callout); 815 timed_out = (d->bd_state == BPF_TIMED_OUT); 816 d->bd_state = BPF_IDLE; 817 while (d->bd_flags & BPFD_HBUF_INUSE) { 818 error = mtx_sleep(&d->bd_hbuf, &d->bd_lock, PRINET | PCATCH, 819 "bd_hbuf", 0); 820 if (error != 0) { 821 BPFD_UNLOCK(d); 822 return (error); 823 } 824 } 825 /* 826 * If the hold buffer is empty, then do a timed sleep, which 827 * ends when the timeout expires or when enough packets 828 * have arrived to fill the store buffer. 829 */ 830 while (d->bd_hbuf == NULL) { 831 if (d->bd_slen != 0) { 832 /* 833 * A packet(s) either arrived since the previous 834 * read or arrived while we were asleep. 835 */ 836 if ((d->bd_flags & BPFD_IMMEDIATE) || non_block || 837 timed_out) { 838 /* 839 * Rotate the buffers and return what's here 840 * if we are in immediate mode, non-blocking 841 * flag is set, or this descriptor timed out. 842 */ 843 ROTATE_BUFFERS(d); 844 break; 845 } 846 } 847 848 /* 849 * No data is available, check to see if the bpf device 850 * is still pointed at a real interface. If not, return 851 * ENXIO so that the userland process knows to rebind 852 * it before using it again. 853 */ 854 if (d->bd_bif == NULL) { 855 BPFD_UNLOCK(d); 856 return (ENXIO); 857 } 858 859 if (non_block) { 860 BPFD_UNLOCK(d); 861 return (EWOULDBLOCK); 862 } 863 error = msleep(d, &d->bd_lock, PRINET | PCATCH, 864 "bpf", d->bd_rtout); 865 if (error == EINTR || error == ERESTART) { 866 BPFD_UNLOCK(d); 867 return (error); 868 } 869 if (error == EWOULDBLOCK) { 870 /* 871 * On a timeout, return what's in the buffer, 872 * which may be nothing. If there is something 873 * in the store buffer, we can rotate the buffers. 874 */ 875 if (d->bd_hbuf) 876 /* 877 * We filled up the buffer in between 878 * getting the timeout and arriving 879 * here, so we don't need to rotate. 880 */ 881 break; 882 883 if (d->bd_slen == 0) { 884 BPFD_UNLOCK(d); 885 return (0); 886 } 887 ROTATE_BUFFERS(d); 888 break; 889 } 890 } 891 /* 892 * At this point, we know we have something in the hold slot. 893 */ 894 d->bd_flags |= BPFD_HBUF_INUSE; 895 BPFD_UNLOCK(d); 896 897 /* 898 * Move data from hold buffer into user space. 899 * We know the entire buffer is transferred since 900 * we checked above that the read buffer is bpf_bufsize bytes. 901 * 902 * We do not have to worry about simultaneous reads because 903 * we waited for sole access to the hold buffer above. 904 */ 905 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 906 907 BPFD_LOCK(d); 908 if (d->bd_flags & BPFD_HBUF_INUSE) { 909 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 910 d->bd_fbuf = d->bd_hbuf; 911 d->bd_hbuf = NULL; 912 d->bd_hlen = 0; 913 bpf_buf_reclaimed(d); 914 d->bd_flags &= ~BPFD_HBUF_INUSE; 915 wakeup(&d->bd_hbuf); 916 } 917 BPFD_UNLOCK(d); 918 919 return (error); 920 } 921 922 /* 923 * If there are processes sleeping on this descriptor, wake them up. 924 */ 925 static __inline void 926 bpf_wakeup(struct bpf_d *d) 927 { 928 929 BPFD_LOCK_ASSERT(d); 930 if (d->bd_state == BPF_WAITING) { 931 callout_stop(&d->bd_callout); 932 d->bd_state = BPF_IDLE; 933 } 934 wakeup(d); 935 if ((d->bd_flags & BPFD_ASYNC) && d->bd_sig && d->bd_sigio) 936 pgsigio(&d->bd_sigio, d->bd_sig, 0); 937 938 selwakeuppri(&d->bd_sel, PRINET); 939 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 940 } 941 942 static void 943 bpf_timed_out(void *arg) 944 { 945 struct bpf_d *d = (struct bpf_d *)arg; 946 947 BPFD_LOCK_ASSERT(d); 948 949 if (callout_pending(&d->bd_callout) || 950 !callout_active(&d->bd_callout)) 951 return; 952 if (d->bd_state == BPF_WAITING) { 953 d->bd_state = BPF_TIMED_OUT; 954 if (d->bd_slen != 0) 955 bpf_wakeup(d); 956 } 957 } 958 959 static int 960 bpf_ready(struct bpf_d *d) 961 { 962 963 BPFD_LOCK_ASSERT(d); 964 965 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 966 return (1); 967 if (((d->bd_flags & BPFD_IMMEDIATE) || d->bd_state == BPF_TIMED_OUT) && 968 d->bd_slen != 0) 969 return (1); 970 return (0); 971 } 972 973 static int 974 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 975 { 976 struct epoch_tracker et; 977 struct bpf_if *bp; 978 struct bpf_d *d; 979 struct mbuf *m, *mc; 980 ssize_t len; 981 int error; 982 983 error = devfs_get_cdevpriv((void **)&d); 984 if (error != 0) 985 return (error); 986 987 if (uio->uio_resid == 0) 988 return (0); 989 990 BPFD_LOCK(d); 991 if ((bp = d->bd_bif) == NULL) 992 error = ENXIO; 993 else if (bp->bif_methods->bif_write == NULL) 994 error = EOPNOTSUPP; 995 if (error) { 996 BPFD_UNLOCK(d); 997 counter_u64_add(d->bd_wdcount, 1); 998 return (error); 999 } 1000 bpfd_ref(d); 1001 BPFD_UNLOCK(d); 1002 1003 len = uio->uio_resid; 1004 /* Allocate a mbuf, up to MJUM16BYTES bytes, for our write. */ 1005 m = m_get3(len, M_WAITOK, MT_DATA, M_PKTHDR); 1006 if (m == NULL) { 1007 error = ENOMEM; 1008 goto fail_wref; 1009 } 1010 m->m_pkthdr.len = m->m_len = len; 1011 1012 error = uiomove(mtod(m, u_char *), len, uio); 1013 if (error) 1014 goto fail_wref; 1015 1016 if (bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len) == 0) { 1017 error = EPERM; 1018 goto fail_wref; 1019 } 1020 1021 if (d->bd_flags & BPFD_FEEDBACK) { 1022 mc = m_dup(m, M_WAITOK); 1023 /* Set M_PROMISC for outgoing packets to be discarded. */ 1024 if (d->bd_direction == BPF_D_INOUT) 1025 m->m_flags |= M_PROMISC; 1026 } else 1027 mc = NULL; 1028 1029 /* XXXGL: should belong to bpf_ifnet.c */ 1030 if (d->bd_pcp != 0) 1031 (void)vlan_set_pcp(m, d->bd_pcp); 1032 1033 BPFD_LOCK(d); 1034 #ifdef MAC 1035 mac_bpfdesc_create_mbuf(d, m); 1036 if (mc != NULL) 1037 mac_bpfdesc_create_mbuf(d, mc); 1038 #endif 1039 /* 1040 * Check that descriptor is still attached to the interface. 1041 * This can happen on bpfdetach() or if other thread did BIOCSDLT. 1042 */ 1043 if (__predict_false(d->bd_bif != bp)) { 1044 BPFD_UNLOCK(d); 1045 m_freem(mc); 1046 error = ENXIO; 1047 goto fail_wref; 1048 } 1049 BPFD_UNLOCK(d); 1050 1051 NET_EPOCH_ENTER(et); 1052 error = bp->bif_methods->bif_write(bp->bif_softc, m, mc, d->bd_flags); 1053 NET_EPOCH_EXIT(et); 1054 if (error) 1055 counter_u64_add(d->bd_wdcount, 1); 1056 else 1057 counter_u64_add(d->bd_wfcount, 1); 1058 bpfd_rele(d); 1059 1060 return (error); 1061 1062 fail_wref: 1063 counter_u64_add(d->bd_wdcount, 1); 1064 bpfd_rele(d); 1065 m_freem(m); 1066 return (error); 1067 } 1068 1069 /* 1070 * Reset a descriptor by flushing its packet buffer and clearing the receive 1071 * and drop counts. This is doable for kernel-only buffers, but with 1072 * zero-copy buffers, we can't write to (or rotate) buffers that are 1073 * currently owned by userspace. It would be nice if we could encapsulate 1074 * this logic in the buffer code rather than here. 1075 */ 1076 static void 1077 reset_d(struct bpf_d *d) 1078 { 1079 1080 BPFD_LOCK_ASSERT(d); 1081 1082 while (d->bd_flags & BPFD_HBUF_INUSE) 1083 mtx_sleep(&d->bd_hbuf, &d->bd_lock, PRINET, "bd_hbuf", 0); 1084 if ((d->bd_hbuf != NULL) && 1085 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1086 /* Free the hold buffer. */ 1087 d->bd_fbuf = d->bd_hbuf; 1088 d->bd_hbuf = NULL; 1089 d->bd_hlen = 0; 1090 bpf_buf_reclaimed(d); 1091 } 1092 if (bpf_canwritebuf(d)) 1093 d->bd_slen = 0; 1094 counter_u64_zero(d->bd_rcount); 1095 counter_u64_zero(d->bd_dcount); 1096 counter_u64_zero(d->bd_fcount); 1097 counter_u64_zero(d->bd_wcount); 1098 counter_u64_zero(d->bd_wfcount); 1099 counter_u64_zero(d->bd_wdcount); 1100 counter_u64_zero(d->bd_zcopy); 1101 } 1102 1103 /* 1104 * FIONREAD Check for read packet available. 1105 * BIOCGETIFLIST Get list of all tap points. 1106 * BIOCGBLEN Get buffer len [for read()]. 1107 * BIOCSETF Set read filter. 1108 * BIOCSETFNR Set read filter without resetting descriptor. 1109 * BIOCSETWF Set write filter. 1110 * BIOCFLUSH Flush read packet buffer. 1111 * BIOCPROMISC Put interface into promiscuous mode. 1112 * BIOCGDLT Get link layer type. 1113 * BIOCGETIF Get interface name. 1114 * BIOCSETIF Set interface. 1115 * BIOCSRTIMEOUT Set read timeout. 1116 * BIOCGRTIMEOUT Get read timeout. 1117 * BIOCGSTATS Get packet stats. 1118 * BIOCIMMEDIATE Set immediate mode. 1119 * BIOCVERSION Get filter language version. 1120 * BIOCGHDRCMPLT Get "header already complete" flag 1121 * BIOCSHDRCMPLT Set "header already complete" flag 1122 * BIOCGDIRECTION Get packet direction flag 1123 * BIOCSDIRECTION Set packet direction flag 1124 * BIOCGTSTAMP Get time stamp format and resolution. 1125 * BIOCSTSTAMP Set time stamp format and resolution. 1126 * BIOCLOCK Set "locked" flag 1127 * BIOCFEEDBACK Set packet feedback mode. 1128 * BIOCSETZBUF Set current zero-copy buffer locations. 1129 * BIOCGETZMAX Get maximum zero-copy buffer size. 1130 * BIOCROTZBUF Force rotation of zero-copy buffer 1131 * BIOCSETBUFMODE Set buffer mode. 1132 * BIOCGETBUFMODE Get current buffer mode. 1133 * BIOCSETVLANPCP Set VLAN PCP tag. 1134 */ 1135 /* ARGSUSED */ 1136 static int 1137 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1138 struct thread *td) 1139 { 1140 struct bpf_d *d; 1141 int error; 1142 1143 error = devfs_get_cdevpriv((void **)&d); 1144 if (error != 0) 1145 return (error); 1146 1147 /* 1148 * Refresh PID associated with this descriptor. 1149 */ 1150 BPFD_LOCK(d); 1151 BPF_PID_REFRESH(d, td); 1152 if (d->bd_state == BPF_WAITING) 1153 callout_stop(&d->bd_callout); 1154 d->bd_state = BPF_IDLE; 1155 BPFD_UNLOCK(d); 1156 1157 if (d->bd_flags & BPFD_LOCKED) { 1158 switch (cmd) { 1159 case BIOCGETIFLIST: 1160 case BIOCGBLEN: 1161 case BIOCFLUSH: 1162 case BIOCGDLT: 1163 case BIOCGDLTLIST: 1164 #ifdef COMPAT_FREEBSD32 1165 case BIOCGDLTLIST32: 1166 #endif 1167 case BIOCGETIF: 1168 case BIOCGRTIMEOUT: 1169 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1170 case BIOCGRTIMEOUT32: 1171 #endif 1172 case BIOCGSTATS: 1173 case BIOCVERSION: 1174 case BIOCGRSIG: 1175 case BIOCGHDRCMPLT: 1176 case BIOCSTSTAMP: 1177 case BIOCFEEDBACK: 1178 case FIONREAD: 1179 case BIOCLOCK: 1180 case BIOCSRTIMEOUT: 1181 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1182 case BIOCSRTIMEOUT32: 1183 #endif 1184 case BIOCIMMEDIATE: 1185 case TIOCGPGRP: 1186 case BIOCROTZBUF: 1187 break; 1188 default: 1189 return (EPERM); 1190 } 1191 } 1192 #ifdef COMPAT_FREEBSD32 1193 /* 1194 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1195 * that it will get 32-bit packet headers. 1196 */ 1197 switch (cmd) { 1198 case BIOCSETF32: 1199 case BIOCSETFNR32: 1200 case BIOCSETWF32: 1201 case BIOCGDLTLIST32: 1202 case BIOCGRTIMEOUT32: 1203 case BIOCSRTIMEOUT32: 1204 if (SV_CURPROC_FLAG(SV_ILP32)) { 1205 BPFD_LOCK(d); 1206 d->bd_compat32 = 1; 1207 BPFD_UNLOCK(d); 1208 } 1209 } 1210 #endif 1211 1212 #if defined(COMPAT_FREEBSD32) 1213 if (SV_CURPROC_FLAG(SV_ILP32)) { 1214 /* 1215 * On platforms other than amd64, BIOC[GS]RTIMEOUT32 is equal to 1216 * BIOC[GS]RTIMEOUT. Since this is difficult to handle in the 1217 * switch command, map them. 1218 */ 1219 if (cmd == BIOCSRTIMEOUT32) 1220 cmd = BIOCSRTIMEOUT; 1221 if (cmd == BIOCGRTIMEOUT32) 1222 cmd = BIOCGRTIMEOUT; 1223 } 1224 #endif 1225 CURVNET_SET(TD_TO_VNET(td)); 1226 switch (cmd) { 1227 default: 1228 error = EINVAL; 1229 break; 1230 1231 /* 1232 * Check for read packet available. 1233 */ 1234 case FIONREAD: 1235 { 1236 int n; 1237 1238 BPFD_LOCK(d); 1239 n = d->bd_slen; 1240 while (d->bd_flags & BPFD_HBUF_INUSE) 1241 mtx_sleep(&d->bd_hbuf, &d->bd_lock, 1242 PRINET, "bd_hbuf", 0); 1243 if (d->bd_hbuf) 1244 n += d->bd_hlen; 1245 BPFD_UNLOCK(d); 1246 1247 *(int *)addr = n; 1248 break; 1249 } 1250 /* 1251 * Get list of all tap points. 1252 */ 1253 case BIOCGETIFLIST: 1254 error = bpf_getiflist((struct bpf_iflist *)addr); 1255 break; 1256 1257 /* 1258 * Get buffer len [for read()]. 1259 */ 1260 case BIOCGBLEN: 1261 BPFD_LOCK(d); 1262 *(u_int *)addr = d->bd_bufsize; 1263 BPFD_UNLOCK(d); 1264 break; 1265 1266 /* 1267 * Set buffer length. 1268 */ 1269 case BIOCSBLEN: 1270 error = bpf_ioctl_sblen(d, (u_int *)addr); 1271 break; 1272 1273 /* 1274 * Set link layer read filter. 1275 */ 1276 case BIOCSETF: 1277 case BIOCSETFNR: 1278 case BIOCSETWF: 1279 #ifdef COMPAT_FREEBSD32 1280 case BIOCSETF32: 1281 case BIOCSETFNR32: 1282 case BIOCSETWF32: 1283 #endif 1284 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1285 break; 1286 1287 /* 1288 * Flush read packet buffer. 1289 */ 1290 case BIOCFLUSH: 1291 BPFD_LOCK(d); 1292 reset_d(d); 1293 BPFD_UNLOCK(d); 1294 break; 1295 1296 /* 1297 * Put interface into promiscuous mode. 1298 */ 1299 case BIOCPROMISC: 1300 BPF_LOCK(); 1301 if (d->bd_bif == NULL) { 1302 /* 1303 * No interface attached yet. 1304 */ 1305 error = EINVAL; 1306 } else if (d->bd_promisc == 0) { 1307 struct bpf_if *bp = d->bd_bif; 1308 1309 if ((error = bif_promisc(bp, true)) == 0) 1310 d->bd_promisc = 1; 1311 } 1312 BPF_UNLOCK(); 1313 break; 1314 1315 /* 1316 * Get current data link type. 1317 */ 1318 case BIOCGDLT: 1319 BPF_LOCK(); 1320 if (d->bd_bif == NULL) 1321 error = EINVAL; 1322 else 1323 *(u_int *)addr = d->bd_bif->bif_dlt; 1324 BPF_UNLOCK(); 1325 break; 1326 1327 /* 1328 * Get a list of supported data link types. 1329 */ 1330 #ifdef COMPAT_FREEBSD32 1331 case BIOCGDLTLIST32: 1332 { 1333 struct bpf_dltlist32 *list32; 1334 struct bpf_dltlist dltlist; 1335 1336 list32 = (struct bpf_dltlist32 *)addr; 1337 dltlist.bfl_len = list32->bfl_len; 1338 dltlist.bfl_list = PTRIN(list32->bfl_list); 1339 BPF_LOCK(); 1340 if (d->bd_bif == NULL) 1341 error = EINVAL; 1342 else { 1343 error = bpf_getdltlist(d, &dltlist); 1344 if (error == 0) 1345 list32->bfl_len = dltlist.bfl_len; 1346 } 1347 BPF_UNLOCK(); 1348 break; 1349 } 1350 #endif 1351 1352 case BIOCGDLTLIST: 1353 BPF_LOCK(); 1354 if (d->bd_bif == NULL) 1355 error = EINVAL; 1356 else 1357 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1358 BPF_UNLOCK(); 1359 break; 1360 1361 /* 1362 * Set data link type. 1363 */ 1364 case BIOCSDLT: 1365 BPF_LOCK(); 1366 if (d->bd_bif == NULL) 1367 error = EINVAL; 1368 else 1369 error = bpf_setdlt(d, *(u_int *)addr); 1370 BPF_UNLOCK(); 1371 break; 1372 1373 /* 1374 * Get interface name. 1375 */ 1376 case BIOCGETIF: 1377 BPF_LOCK(); 1378 if (d->bd_bif == NULL) 1379 error = EINVAL; 1380 else { 1381 struct bpf_if *const bp = d->bd_bif; 1382 struct ifreq *const ifr = (struct ifreq *)addr; 1383 1384 strlcpy(ifr->ifr_name, bp->bif_name, 1385 sizeof(ifr->ifr_name)); 1386 } 1387 BPF_UNLOCK(); 1388 break; 1389 1390 /* 1391 * Set interface. 1392 */ 1393 case BIOCSETIF: { 1394 struct ifreq *const ifr = (struct ifreq *)addr; 1395 struct bpf_if *bp; 1396 1397 /* 1398 * Behavior here depends on the buffering model. If we're 1399 * using kernel memory buffers, then we can allocate them here. 1400 * If we're using zero-copy, then the user process must have 1401 * registered buffers by the time we get here. 1402 */ 1403 BPFD_LOCK(d); 1404 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1405 d->bd_sbuf == NULL) { 1406 u_int size; 1407 1408 size = d->bd_bufsize; 1409 BPFD_UNLOCK(d); 1410 error = bpf_buffer_ioctl_sblen(d, &size); 1411 if (error != 0) 1412 break; 1413 } else 1414 BPFD_UNLOCK(d); 1415 BPF_LOCK(); 1416 /* 1417 * Look through attached interfaces for the named one. 1418 */ 1419 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 1420 if (strncmp(ifr->ifr_name, bp->bif_name, 1421 sizeof(ifr->ifr_name)) == 0) 1422 break; 1423 } 1424 if (bp != NULL) 1425 error = bpf_attachd(d, bp); 1426 else 1427 error = ENXIO; 1428 BPF_UNLOCK(); 1429 break; 1430 } 1431 /* 1432 * Set read timeout. 1433 */ 1434 case BIOCSRTIMEOUT: 1435 { 1436 struct timeval *tv = (struct timeval *)addr; 1437 #ifdef COMPAT_FREEBSD32 1438 struct timeval32 *tv32; 1439 struct timeval tv64; 1440 1441 if (SV_CURPROC_FLAG(SV_ILP32)) { 1442 tv32 = (struct timeval32 *)addr; 1443 tv = &tv64; 1444 tv->tv_sec = tv32->tv_sec; 1445 tv->tv_usec = tv32->tv_usec; 1446 } 1447 #endif 1448 1449 /* 1450 * Subtract 1 tick from tvtohz() since this isn't 1451 * a one-shot timer. 1452 */ 1453 if ((error = itimerfix(tv)) == 0) 1454 d->bd_rtout = tvtohz(tv) - 1; 1455 break; 1456 } 1457 1458 /* 1459 * Get read timeout. 1460 */ 1461 case BIOCGRTIMEOUT: 1462 { 1463 struct timeval *tv = (struct timeval *)addr; 1464 #ifdef COMPAT_FREEBSD32 1465 struct timeval32 *tv32; 1466 struct timeval tv64; 1467 1468 if (SV_CURPROC_FLAG(SV_ILP32)) 1469 tv = &tv64; 1470 #endif 1471 tv->tv_sec = d->bd_rtout / hz; 1472 tv->tv_usec = (d->bd_rtout % hz) * tick; 1473 #ifdef COMPAT_FREEBSD32 1474 if (SV_CURPROC_FLAG(SV_ILP32)) { 1475 tv32 = (struct timeval32 *)addr; 1476 tv32->tv_sec = tv->tv_sec; 1477 tv32->tv_usec = tv->tv_usec; 1478 } 1479 #endif 1480 break; 1481 } 1482 1483 /* 1484 * Get packet stats. 1485 */ 1486 case BIOCGSTATS: 1487 { 1488 struct bpf_stat *bs = (struct bpf_stat *)addr; 1489 1490 /* XXXCSJP overflow */ 1491 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1492 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1493 break; 1494 } 1495 1496 /* 1497 * Set immediate mode. 1498 */ 1499 case BIOCIMMEDIATE: 1500 BPFD_LOCK(d); 1501 d->bd_flags |= *(u_int *)addr ? BPFD_IMMEDIATE : 0; 1502 BPFD_UNLOCK(d); 1503 break; 1504 1505 case BIOCVERSION: 1506 { 1507 struct bpf_version *bv = (struct bpf_version *)addr; 1508 1509 bv->bv_major = BPF_MAJOR_VERSION; 1510 bv->bv_minor = BPF_MINOR_VERSION; 1511 break; 1512 } 1513 1514 /* 1515 * Get "header already complete" flag 1516 */ 1517 case BIOCGHDRCMPLT: 1518 BPFD_LOCK(d); 1519 *(u_int *)addr = d->bd_flags & BPFD_HDRCMPLT ? 1 : 0; 1520 BPFD_UNLOCK(d); 1521 break; 1522 1523 /* 1524 * Set "header already complete" flag 1525 */ 1526 case BIOCSHDRCMPLT: 1527 BPFD_LOCK(d); 1528 d->bd_flags |= *(u_int *)addr ? BPFD_HDRCMPLT : 0; 1529 BPFD_UNLOCK(d); 1530 break; 1531 1532 /* 1533 * Get packet direction flag 1534 */ 1535 case BIOCGDIRECTION: 1536 BPFD_LOCK(d); 1537 *(u_int *)addr = d->bd_direction; 1538 BPFD_UNLOCK(d); 1539 break; 1540 1541 /* 1542 * Set packet direction flag 1543 */ 1544 case BIOCSDIRECTION: 1545 { 1546 u_int direction; 1547 1548 direction = *(u_int *)addr; 1549 switch (direction) { 1550 case BPF_D_IN: 1551 case BPF_D_INOUT: 1552 case BPF_D_OUT: 1553 BPFD_LOCK(d); 1554 d->bd_direction = direction; 1555 BPFD_UNLOCK(d); 1556 break; 1557 default: 1558 error = EINVAL; 1559 } 1560 } 1561 break; 1562 1563 /* 1564 * Get packet timestamp format and resolution. 1565 */ 1566 case BIOCGTSTAMP: 1567 BPFD_LOCK(d); 1568 *(u_int *)addr = d->bd_tstamp; 1569 BPFD_UNLOCK(d); 1570 break; 1571 1572 /* 1573 * Set packet timestamp format and resolution. 1574 */ 1575 case BIOCSTSTAMP: 1576 { 1577 u_int func; 1578 1579 func = *(u_int *)addr; 1580 if (BPF_T_VALID(func)) 1581 d->bd_tstamp = func; 1582 else 1583 error = EINVAL; 1584 } 1585 break; 1586 1587 case BIOCFEEDBACK: 1588 BPFD_LOCK(d); 1589 d->bd_flags |= *(u_int *)addr ? BPFD_FEEDBACK : 0; 1590 BPFD_UNLOCK(d); 1591 break; 1592 1593 case BIOCLOCK: 1594 BPFD_LOCK(d); 1595 d->bd_flags |= BPFD_LOCKED; 1596 BPFD_UNLOCK(d); 1597 break; 1598 1599 case FIONBIO: /* Non-blocking I/O */ 1600 break; 1601 1602 case FIOASYNC: /* Send signal on receive packets */ 1603 BPFD_LOCK(d); 1604 d->bd_flags |= *(u_int *)addr ? BPFD_ASYNC : 0; 1605 BPFD_UNLOCK(d); 1606 break; 1607 1608 case FIOSETOWN: 1609 /* 1610 * XXX: Add some sort of locking here? 1611 * fsetown() can sleep. 1612 */ 1613 error = fsetown(*(int *)addr, &d->bd_sigio); 1614 break; 1615 1616 case FIOGETOWN: 1617 BPFD_LOCK(d); 1618 *(int *)addr = fgetown(&d->bd_sigio); 1619 BPFD_UNLOCK(d); 1620 break; 1621 1622 /* This is deprecated, FIOSETOWN should be used instead. */ 1623 case TIOCSPGRP: 1624 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1625 break; 1626 1627 /* This is deprecated, FIOGETOWN should be used instead. */ 1628 case TIOCGPGRP: 1629 *(int *)addr = -fgetown(&d->bd_sigio); 1630 break; 1631 1632 case BIOCSRSIG: /* Set receive signal */ 1633 { 1634 u_int sig; 1635 1636 sig = *(u_int *)addr; 1637 1638 if (sig >= NSIG) 1639 error = EINVAL; 1640 else { 1641 BPFD_LOCK(d); 1642 d->bd_sig = sig; 1643 BPFD_UNLOCK(d); 1644 } 1645 break; 1646 } 1647 case BIOCGRSIG: 1648 BPFD_LOCK(d); 1649 *(u_int *)addr = d->bd_sig; 1650 BPFD_UNLOCK(d); 1651 break; 1652 1653 case BIOCGETBUFMODE: 1654 BPFD_LOCK(d); 1655 *(u_int *)addr = d->bd_bufmode; 1656 BPFD_UNLOCK(d); 1657 break; 1658 1659 case BIOCSETBUFMODE: 1660 /* 1661 * Allow the buffering mode to be changed as long as we 1662 * haven't yet committed to a particular mode. Our 1663 * definition of commitment, for now, is whether or not a 1664 * buffer has been allocated or an interface attached, since 1665 * that's the point where things get tricky. 1666 */ 1667 switch (*(u_int *)addr) { 1668 case BPF_BUFMODE_BUFFER: 1669 break; 1670 1671 case BPF_BUFMODE_ZBUF: 1672 if (bpf_zerocopy_enable) 1673 break; 1674 /* FALLSTHROUGH */ 1675 1676 default: 1677 CURVNET_RESTORE(); 1678 return (EINVAL); 1679 } 1680 1681 BPFD_LOCK(d); 1682 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1683 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1684 BPFD_UNLOCK(d); 1685 CURVNET_RESTORE(); 1686 return (EBUSY); 1687 } 1688 d->bd_bufmode = *(u_int *)addr; 1689 BPFD_UNLOCK(d); 1690 break; 1691 1692 case BIOCGETZMAX: 1693 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1694 break; 1695 1696 case BIOCSETZBUF: 1697 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1698 break; 1699 1700 case BIOCROTZBUF: 1701 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1702 break; 1703 1704 case BIOCSETVLANPCP: 1705 { 1706 u_int pcp; 1707 1708 pcp = *(u_int *)addr; 1709 if (pcp > BPF_PRIO_MAX || pcp < 0) { 1710 error = EINVAL; 1711 break; 1712 } 1713 d->bd_pcp = pcp; 1714 break; 1715 } 1716 } 1717 CURVNET_RESTORE(); 1718 return (error); 1719 } 1720 1721 /* 1722 * Return list of available tapping points, or report how much space is 1723 * required for a successful return. 1724 */ 1725 static int 1726 bpf_getiflist(struct bpf_iflist *bi) 1727 { 1728 struct bpf_if *bp; 1729 u_int allsize, size, cnt; 1730 char *uaddr; 1731 1732 BPF_LOCK(); 1733 1734 cnt = allsize = size = 0; 1735 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 1736 allsize += strlen(bp->bif_name) + 1; 1737 if (++cnt == bi->bi_count) 1738 size = allsize; 1739 } 1740 if (size == 0) 1741 size = allsize; 1742 1743 if (bi->bi_size == 0) { 1744 BPF_UNLOCK(); 1745 bi->bi_size = size; 1746 bi->bi_count = cnt; 1747 return (0); 1748 } else if (bi->bi_size < size) { 1749 BPF_UNLOCK(); 1750 return (ENOSPC); 1751 } 1752 1753 uaddr = bi->bi_ubuf; 1754 cnt = 0; 1755 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 1756 u_int len; 1757 int error; 1758 1759 len = strlen(bp->bif_name) + 1; 1760 if ((error = copyout(bp->bif_name, uaddr, len)) != 0) { 1761 BPF_UNLOCK(); 1762 return (error); 1763 } 1764 if (++cnt == bi->bi_count) 1765 break; 1766 uaddr += len; 1767 } 1768 BPF_UNLOCK(); 1769 bi->bi_count = cnt; 1770 1771 return (0); 1772 } 1773 1774 /* 1775 * Set d's packet filter program to fp. If this file already has a filter, 1776 * free it and replace it. Returns EINVAL for bogus requests. 1777 * 1778 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1779 * calls. 1780 */ 1781 static int 1782 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1783 { 1784 #ifdef COMPAT_FREEBSD32 1785 struct bpf_program fp_swab; 1786 struct bpf_program32 *fp32; 1787 #endif 1788 struct bpf_program_buffer *fcode; 1789 struct bpf_insn *filter; 1790 #ifdef BPF_JITTER 1791 bpf_jit_filter *jfunc; 1792 #endif 1793 size_t size; 1794 u_int flen; 1795 bool track_event; 1796 1797 #ifdef COMPAT_FREEBSD32 1798 switch (cmd) { 1799 case BIOCSETF32: 1800 case BIOCSETWF32: 1801 case BIOCSETFNR32: 1802 fp32 = (struct bpf_program32 *)fp; 1803 fp_swab.bf_len = fp32->bf_len; 1804 fp_swab.bf_insns = 1805 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1806 fp = &fp_swab; 1807 switch (cmd) { 1808 case BIOCSETF32: 1809 cmd = BIOCSETF; 1810 break; 1811 case BIOCSETWF32: 1812 cmd = BIOCSETWF; 1813 break; 1814 } 1815 break; 1816 } 1817 #endif 1818 1819 filter = NULL; 1820 #ifdef BPF_JITTER 1821 jfunc = NULL; 1822 #endif 1823 /* 1824 * Check new filter validness before acquiring any locks. 1825 * Allocate memory for new filter, if needed. 1826 */ 1827 flen = fp->bf_len; 1828 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1829 return (EINVAL); 1830 size = flen * sizeof(*fp->bf_insns); 1831 if (size > 0) { 1832 /* We're setting up new filter. Copy and check actual data. */ 1833 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1834 filter = (struct bpf_insn *)fcode->buffer; 1835 if (copyin(fp->bf_insns, filter, size) != 0 || 1836 !bpf_validate(filter, flen)) { 1837 free(fcode, M_BPF); 1838 return (EINVAL); 1839 } 1840 #ifdef BPF_JITTER 1841 if (cmd != BIOCSETWF) { 1842 /* 1843 * Filter is copied inside fcode and is 1844 * perfectly valid. 1845 */ 1846 jfunc = bpf_jitter(filter, flen); 1847 } 1848 #endif 1849 } 1850 1851 track_event = false; 1852 fcode = NULL; 1853 1854 BPF_LOCK(); 1855 BPFD_LOCK(d); 1856 /* Set up new filter. */ 1857 if (cmd == BIOCSETWF) { 1858 if (d->bd_wfilter != NULL) { 1859 fcode = __containerof((void *)d->bd_wfilter, 1860 struct bpf_program_buffer, buffer); 1861 #ifdef BPF_JITTER 1862 fcode->func = NULL; 1863 #endif 1864 } 1865 d->bd_wfilter = filter; 1866 } else { 1867 if (d->bd_rfilter != NULL) { 1868 fcode = __containerof((void *)d->bd_rfilter, 1869 struct bpf_program_buffer, buffer); 1870 #ifdef BPF_JITTER 1871 fcode->func = d->bd_bfilter; 1872 #endif 1873 } 1874 d->bd_rfilter = filter; 1875 #ifdef BPF_JITTER 1876 d->bd_bfilter = jfunc; 1877 #endif 1878 if (cmd == BIOCSETF) 1879 reset_d(d); 1880 1881 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 1882 /* 1883 * Filter can be set several times without 1884 * specifying interface. In this case just mark d 1885 * as reader. 1886 */ 1887 d->bd_writer = 0; 1888 if (d->bd_bif != NULL) { 1889 /* 1890 * Remove descriptor from writers-only list 1891 * and add it to active readers list. 1892 */ 1893 CK_LIST_REMOVE(d, bd_next); 1894 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 1895 d, bd_next); 1896 CTR2(KTR_NET, 1897 "%s: upgrade required by pid %d", 1898 __func__, d->bd_pid); 1899 track_event = true; 1900 } 1901 } 1902 } 1903 BPFD_UNLOCK(d); 1904 1905 if (fcode != NULL) 1906 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 1907 1908 if (track_event) 1909 bif_attachd(d->bd_bif); 1910 1911 BPF_UNLOCK(); 1912 return (0); 1913 } 1914 1915 /* 1916 * Attach descriptor to a tap point, possibly detaching from the old one, 1917 * reset the counters. 1918 * XXXGL: this KPI is subject to change 1919 */ 1920 static int 1921 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 1922 { 1923 bool writer; 1924 1925 BPF_LOCK_ASSERT(); 1926 1927 /* 1928 * At this point, we expect the buffer is already allocated. If not, 1929 * return an error. 1930 */ 1931 switch (d->bd_bufmode) { 1932 case BPF_BUFMODE_BUFFER: 1933 case BPF_BUFMODE_ZBUF: 1934 if (d->bd_sbuf == NULL) 1935 return (EINVAL); 1936 break; 1937 1938 default: 1939 panic("%s: bufmode %d", __func__, d->bd_bufmode); 1940 } 1941 1942 if (bp == d->bd_bif) { 1943 BPFD_LOCK(d); 1944 reset_d(d); 1945 BPFD_UNLOCK(d); 1946 return (0); 1947 } else if (d->bd_bif != NULL) 1948 bpf_detachd(d, false); 1949 1950 /* 1951 * Save sysctl value to protect from sysctl change between reads. 1952 */ 1953 writer = V_bpf_optimize_writers || (d->bd_writer > 0); 1954 1955 /* 1956 * Point d at bp, and add d to the interface's list. 1957 * Since there are many applications using BPF for 1958 * sending raw packets only (dhcpd, cdpd are good examples) 1959 * we can delay adding d to the list of active listeners until 1960 * some filter is configured. 1961 */ 1962 BPFD_LOCK(d); 1963 /* 1964 * Hold reference to bpif while descriptor uses this interface. 1965 */ 1966 bpfif_ref(bp); 1967 d->bd_bif = bp; 1968 if (writer) { 1969 /* Add to writers-only list */ 1970 CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 1971 /* 1972 * We decrement bd_writer on every filter set operation. 1973 * First BIOCSETF is done by pcap_open_live() to set up 1974 * snap length. After that application usually sets its own 1975 * filter. 1976 */ 1977 d->bd_writer = 2; 1978 } else 1979 CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 1980 1981 reset_d(d); 1982 1983 /* Trigger EVFILT_WRITE events. */ 1984 bpf_wakeup(d); 1985 1986 BPFD_UNLOCK(d); 1987 1988 CTR3(KTR_NET, "%s: called by pid %d, adding to %s list", 1989 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 1990 1991 if (!writer) 1992 bif_attachd(bp); 1993 1994 return (0); 1995 } 1996 1997 /* 1998 * Support for select() and poll() system calls 1999 * 2000 * Return true iff the specific operation will not block indefinitely. 2001 * Otherwise, return false but make a note that a selwakeup() must be done. 2002 */ 2003 static int 2004 bpfpoll(struct cdev *dev, int events, struct thread *td) 2005 { 2006 struct bpf_d *d; 2007 int revents; 2008 2009 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2010 return (events & 2011 (POLLHUP | POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM)); 2012 2013 /* 2014 * Refresh PID associated with this descriptor. 2015 */ 2016 revents = events & (POLLOUT | POLLWRNORM); 2017 BPFD_LOCK(d); 2018 BPF_PID_REFRESH(d, td); 2019 if (events & (POLLIN | POLLRDNORM)) { 2020 if (bpf_ready(d)) 2021 revents |= events & (POLLIN | POLLRDNORM); 2022 else { 2023 selrecord(td, &d->bd_sel); 2024 /* Start the read timeout if necessary. */ 2025 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2026 callout_reset(&d->bd_callout, d->bd_rtout, 2027 bpf_timed_out, d); 2028 d->bd_state = BPF_WAITING; 2029 } 2030 } 2031 } 2032 BPFD_UNLOCK(d); 2033 return (revents); 2034 } 2035 2036 /* 2037 * Support for kevent() system call. Register EVFILT_READ filters and 2038 * reject all others. 2039 */ 2040 int 2041 bpfkqfilter(struct cdev *dev, struct knote *kn) 2042 { 2043 struct bpf_d *d; 2044 2045 if (devfs_get_cdevpriv((void **)&d) != 0) 2046 return (1); 2047 2048 switch (kn->kn_filter) { 2049 case EVFILT_READ: 2050 kn->kn_fop = &bpfread_filtops; 2051 break; 2052 2053 case EVFILT_WRITE: 2054 kn->kn_fop = &bpfwrite_filtops; 2055 break; 2056 2057 default: 2058 return (1); 2059 } 2060 2061 /* 2062 * Refresh PID associated with this descriptor. 2063 */ 2064 BPFD_LOCK(d); 2065 BPF_PID_REFRESH_CUR(d); 2066 kn->kn_hook = d; 2067 knlist_add(&d->bd_sel.si_note, kn, 1); 2068 BPFD_UNLOCK(d); 2069 2070 return (0); 2071 } 2072 2073 static void 2074 filt_bpfdetach(struct knote *kn) 2075 { 2076 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2077 2078 knlist_remove(&d->bd_sel.si_note, kn, 0); 2079 } 2080 2081 static int 2082 filt_bpfread(struct knote *kn, long hint) 2083 { 2084 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2085 int ready; 2086 2087 BPFD_LOCK_ASSERT(d); 2088 ready = bpf_ready(d); 2089 if (ready) { 2090 kn->kn_data = d->bd_slen; 2091 /* 2092 * Ignore the hold buffer if it is being copied to user space. 2093 */ 2094 if (!(d->bd_flags & BPFD_HBUF_INUSE) && d->bd_hbuf) 2095 kn->kn_data += d->bd_hlen; 2096 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2097 callout_reset(&d->bd_callout, d->bd_rtout, 2098 bpf_timed_out, d); 2099 d->bd_state = BPF_WAITING; 2100 } 2101 2102 return (ready); 2103 } 2104 2105 static int 2106 filt_bpfwrite(struct knote *kn, long hint) 2107 { 2108 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2109 2110 BPFD_LOCK_ASSERT(d); 2111 2112 if (d->bd_bif == NULL) { 2113 kn->kn_data = 0; 2114 return (0); 2115 } else { 2116 kn->kn_data = bif_wrsize(d->bd_bif); 2117 return (1); 2118 } 2119 } 2120 2121 #define BPF_TSTAMP_NONE 0 2122 #define BPF_TSTAMP_FAST 1 2123 #define BPF_TSTAMP_NORMAL 2 2124 #define BPF_TSTAMP_EXTERN 3 2125 2126 static int 2127 bpf_ts_quality(int tstype) 2128 { 2129 2130 if (tstype == BPF_T_NONE) 2131 return (BPF_TSTAMP_NONE); 2132 if ((tstype & BPF_T_FAST) != 0) 2133 return (BPF_TSTAMP_FAST); 2134 2135 return (BPF_TSTAMP_NORMAL); 2136 } 2137 2138 static int 2139 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2140 { 2141 struct timespec ts; 2142 struct m_tag *tag; 2143 int quality; 2144 2145 quality = bpf_ts_quality(tstype); 2146 if (quality == BPF_TSTAMP_NONE) 2147 return (quality); 2148 2149 if (m != NULL) { 2150 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { 2151 mbuf_tstmp2timespec(m, &ts); 2152 timespec2bintime(&ts, bt); 2153 return (BPF_TSTAMP_EXTERN); 2154 } 2155 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2156 if (tag != NULL) { 2157 *bt = *(struct bintime *)(tag + 1); 2158 return (BPF_TSTAMP_EXTERN); 2159 } 2160 } 2161 if (quality == BPF_TSTAMP_NORMAL) 2162 binuptime(bt); 2163 else 2164 getbinuptime(bt); 2165 2166 return (quality); 2167 } 2168 2169 /* 2170 * Incoming linkage from device drivers. Process the packet pkt, of length 2171 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2172 * by each process' filter, and if accepted, stashed into the corresponding 2173 * buffer. 2174 */ 2175 void 2176 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2177 { 2178 struct epoch_tracker et; 2179 struct bintime bt; 2180 struct bpf_d *d; 2181 #ifdef BPF_JITTER 2182 bpf_jit_filter *bf; 2183 #endif 2184 u_int slen; 2185 int gottime; 2186 2187 gottime = BPF_TSTAMP_NONE; 2188 NET_EPOCH_ENTER(et); 2189 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2190 counter_u64_add(d->bd_rcount, 1); 2191 /* 2192 * NB: We don't check the direction here since there 2193 * is no way for the caller to indiciate to us whether this 2194 * packet is inbound or outbound. In the bpf_mtap() routines, 2195 * we use the interface pointers on the mbuf to figure it out. 2196 */ 2197 #ifdef BPF_JITTER 2198 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2199 if (bf != NULL) 2200 slen = (*(bf->func))(pkt, pktlen, pktlen); 2201 else 2202 #endif 2203 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2204 if (slen != 0) { 2205 /* 2206 * Filter matches. Let's to acquire write lock. 2207 */ 2208 BPFD_LOCK(d); 2209 counter_u64_add(d->bd_fcount, 1); 2210 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2211 gottime = bpf_gettime(&bt, d->bd_tstamp, 2212 NULL); 2213 #ifdef MAC 2214 if (bif_mac_check_receive(bp, d) == 0) 2215 #endif 2216 catchpacket(d, pkt, pktlen, slen, 2217 bpf_append_bytes, &bt); 2218 BPFD_UNLOCK(d); 2219 } 2220 } 2221 NET_EPOCH_EXIT(et); 2222 } 2223 2224 void 2225 bpf_tap_if(if_t ifp, u_char *pkt, u_int pktlen) 2226 { 2227 if (bpf_peers_present(ifp->if_bpf)) 2228 bpf_tap(ifp->if_bpf, pkt, pktlen); 2229 } 2230 2231 /* 2232 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2233 * Locking model is explained in bpf_tap(). 2234 */ 2235 void 2236 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2237 { 2238 struct epoch_tracker et; 2239 struct bintime bt; 2240 struct bpf_d *d; 2241 #ifdef BPF_JITTER 2242 bpf_jit_filter *bf; 2243 #endif 2244 u_int pktlen, slen; 2245 int gottime; 2246 2247 /* Skip outgoing duplicate packets. */ 2248 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2249 m->m_flags &= ~M_PROMISC; 2250 return; 2251 } 2252 2253 pktlen = m_length(m, NULL); 2254 gottime = BPF_TSTAMP_NONE; 2255 2256 NET_EPOCH_ENTER(et); 2257 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2258 if (bpf_chkdir(d, m)) 2259 continue; 2260 counter_u64_add(d->bd_rcount, 1); 2261 #ifdef BPF_JITTER 2262 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2263 /* XXX We cannot handle multiple mbufs. */ 2264 if (bf != NULL && m->m_next == NULL) 2265 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2266 pktlen); 2267 else 2268 #endif 2269 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2270 if (slen != 0) { 2271 BPFD_LOCK(d); 2272 2273 counter_u64_add(d->bd_fcount, 1); 2274 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2275 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2276 #ifdef MAC 2277 if (bif_mac_check_receive(bp, d) == 0) 2278 #endif 2279 catchpacket(d, (u_char *)m, pktlen, slen, 2280 bpf_append_mbuf, &bt); 2281 BPFD_UNLOCK(d); 2282 } 2283 } 2284 NET_EPOCH_EXIT(et); 2285 } 2286 2287 void 2288 bpf_mtap_if(if_t ifp, struct mbuf *m) 2289 { 2290 if (bpf_peers_present(ifp->if_bpf)) { 2291 M_ASSERTVALID(m); 2292 bpf_mtap(ifp->if_bpf, m); 2293 } 2294 } 2295 2296 /* 2297 * Incoming linkage from device drivers, when packet is in 2298 * an mbuf chain and to be prepended by a contiguous header. 2299 */ 2300 void 2301 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2302 { 2303 struct epoch_tracker et; 2304 struct bintime bt; 2305 struct mbuf mb; 2306 struct bpf_d *d; 2307 u_int pktlen, slen; 2308 int gottime; 2309 2310 /* Skip outgoing duplicate packets. */ 2311 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2312 m->m_flags &= ~M_PROMISC; 2313 return; 2314 } 2315 2316 pktlen = m_length(m, NULL); 2317 /* 2318 * Craft on-stack mbuf suitable for passing to bpf_filter. 2319 * Note that we cut corners here; we only setup what's 2320 * absolutely needed--this mbuf should never go anywhere else. 2321 */ 2322 mb.m_flags = 0; 2323 mb.m_next = m; 2324 mb.m_data = data; 2325 mb.m_len = dlen; 2326 pktlen += dlen; 2327 2328 gottime = BPF_TSTAMP_NONE; 2329 2330 NET_EPOCH_ENTER(et); 2331 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2332 if (bpf_chkdir(d, m)) 2333 continue; 2334 counter_u64_add(d->bd_rcount, 1); 2335 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2336 if (slen != 0) { 2337 BPFD_LOCK(d); 2338 2339 counter_u64_add(d->bd_fcount, 1); 2340 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2341 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2342 #ifdef MAC 2343 if (bif_mac_check_receive(bp, d) == 0) 2344 #endif 2345 catchpacket(d, (u_char *)&mb, pktlen, slen, 2346 bpf_append_mbuf, &bt); 2347 BPFD_UNLOCK(d); 2348 } 2349 } 2350 NET_EPOCH_EXIT(et); 2351 } 2352 2353 void 2354 bpf_mtap2_if(if_t ifp, void *data, u_int dlen, struct mbuf *m) 2355 { 2356 if (bpf_peers_present(ifp->if_bpf)) { 2357 M_ASSERTVALID(m); 2358 bpf_mtap2(ifp->if_bpf, data, dlen, m); 2359 } 2360 } 2361 2362 #undef BPF_TSTAMP_NONE 2363 #undef BPF_TSTAMP_FAST 2364 #undef BPF_TSTAMP_NORMAL 2365 #undef BPF_TSTAMP_EXTERN 2366 2367 static int 2368 bpf_hdrlen(struct bpf_d *d) 2369 { 2370 int hdrlen; 2371 2372 hdrlen = d->bd_bif->bif_hdrlen; 2373 #ifndef BURN_BRIDGES 2374 if (d->bd_tstamp == BPF_T_NONE || 2375 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2376 #ifdef COMPAT_FREEBSD32 2377 if (d->bd_compat32) 2378 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2379 else 2380 #endif 2381 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2382 else 2383 #endif 2384 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2385 #ifdef COMPAT_FREEBSD32 2386 if (d->bd_compat32) 2387 hdrlen = BPF_WORDALIGN32(hdrlen); 2388 else 2389 #endif 2390 hdrlen = BPF_WORDALIGN(hdrlen); 2391 2392 return (hdrlen - d->bd_bif->bif_hdrlen); 2393 } 2394 2395 static void 2396 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2397 { 2398 struct bintime bt2, boottimebin; 2399 struct timeval tsm; 2400 struct timespec tsn; 2401 2402 if ((tstype & BPF_T_MONOTONIC) == 0) { 2403 bt2 = *bt; 2404 getboottimebin(&boottimebin); 2405 bintime_add(&bt2, &boottimebin); 2406 bt = &bt2; 2407 } 2408 switch (BPF_T_FORMAT(tstype)) { 2409 case BPF_T_MICROTIME: 2410 bintime2timeval(bt, &tsm); 2411 ts->bt_sec = tsm.tv_sec; 2412 ts->bt_frac = tsm.tv_usec; 2413 break; 2414 case BPF_T_NANOTIME: 2415 bintime2timespec(bt, &tsn); 2416 ts->bt_sec = tsn.tv_sec; 2417 ts->bt_frac = tsn.tv_nsec; 2418 break; 2419 case BPF_T_BINTIME: 2420 ts->bt_sec = bt->sec; 2421 ts->bt_frac = bt->frac; 2422 break; 2423 } 2424 } 2425 2426 /* 2427 * Move the packet data from interface memory (pkt) into the 2428 * store buffer. "cpfn" is the routine called to do the actual data 2429 * transfer. bcopy is passed in to copy contiguous chunks, while 2430 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2431 * pkt is really an mbuf. 2432 */ 2433 static void 2434 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2435 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2436 struct bintime *bt) 2437 { 2438 static char zeroes[BPF_ALIGNMENT]; 2439 struct bpf_xhdr hdr; 2440 #ifndef BURN_BRIDGES 2441 struct bpf_hdr hdr_old; 2442 #ifdef COMPAT_FREEBSD32 2443 struct bpf_hdr32 hdr32_old; 2444 #endif 2445 #endif 2446 int caplen, curlen, hdrlen, pad, totlen; 2447 int do_wakeup = 0; 2448 int do_timestamp; 2449 int tstype; 2450 2451 BPFD_LOCK_ASSERT(d); 2452 if (d->bd_bif == NULL) { 2453 /* Descriptor was detached in concurrent thread */ 2454 counter_u64_add(d->bd_dcount, 1); 2455 return; 2456 } 2457 2458 /* 2459 * Detect whether user space has released a buffer back to us, and if 2460 * so, move it from being a hold buffer to a free buffer. This may 2461 * not be the best place to do it (for example, we might only want to 2462 * run this check if we need the space), but for now it's a reliable 2463 * spot to do it. 2464 */ 2465 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2466 d->bd_fbuf = d->bd_hbuf; 2467 d->bd_hbuf = NULL; 2468 d->bd_hlen = 0; 2469 bpf_buf_reclaimed(d); 2470 } 2471 2472 /* 2473 * Figure out how many bytes to move. If the packet is 2474 * greater or equal to the snapshot length, transfer that 2475 * much. Otherwise, transfer the whole packet (unless 2476 * we hit the buffer size limit). 2477 */ 2478 hdrlen = bpf_hdrlen(d); 2479 totlen = hdrlen + min(snaplen, pktlen); 2480 if (totlen > d->bd_bufsize) 2481 totlen = d->bd_bufsize; 2482 2483 /* 2484 * Round up the end of the previous packet to the next longword. 2485 * 2486 * Drop the packet if there's no room and no hope of room 2487 * If the packet would overflow the storage buffer or the storage 2488 * buffer is considered immutable by the buffer model, try to rotate 2489 * the buffer and wakeup pending processes. 2490 */ 2491 #ifdef COMPAT_FREEBSD32 2492 if (d->bd_compat32) 2493 curlen = BPF_WORDALIGN32(d->bd_slen); 2494 else 2495 #endif 2496 curlen = BPF_WORDALIGN(d->bd_slen); 2497 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2498 if (d->bd_fbuf == NULL) { 2499 /* 2500 * There's no room in the store buffer, and no 2501 * prospect of room, so drop the packet. Notify the 2502 * buffer model. 2503 */ 2504 bpf_buffull(d); 2505 counter_u64_add(d->bd_dcount, 1); 2506 return; 2507 } 2508 KASSERT(!(d->bd_flags & BPFD_HBUF_INUSE), 2509 ("hold buffer is in use")); 2510 ROTATE_BUFFERS(d); 2511 do_wakeup = 1; 2512 curlen = 0; 2513 } else { 2514 if ((d->bd_flags & BPFD_IMMEDIATE) || 2515 d->bd_state == BPF_TIMED_OUT) { 2516 /* 2517 * Immediate mode is set, or the read timeout has 2518 * already expired during a select call. A packet 2519 * arrived, so the reader should be woken up. 2520 */ 2521 do_wakeup = 1; 2522 } 2523 pad = curlen - d->bd_slen; 2524 KASSERT(pad >= 0 && pad <= sizeof(zeroes), 2525 ("%s: invalid pad byte count %d", __func__, pad)); 2526 if (pad > 0) { 2527 /* Zero pad bytes. */ 2528 bpf_append_bytes(d, d->bd_sbuf, d->bd_slen, zeroes, 2529 pad); 2530 } 2531 } 2532 2533 caplen = totlen - hdrlen; 2534 tstype = d->bd_tstamp; 2535 do_timestamp = tstype != BPF_T_NONE; 2536 #ifndef BURN_BRIDGES 2537 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2538 struct bpf_ts ts; 2539 if (do_timestamp) 2540 bpf_bintime2ts(bt, &ts, tstype); 2541 #ifdef COMPAT_FREEBSD32 2542 if (d->bd_compat32) { 2543 bzero(&hdr32_old, sizeof(hdr32_old)); 2544 if (do_timestamp) { 2545 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2546 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2547 } 2548 hdr32_old.bh_datalen = pktlen; 2549 hdr32_old.bh_hdrlen = hdrlen; 2550 hdr32_old.bh_caplen = caplen; 2551 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2552 sizeof(hdr32_old)); 2553 goto copy; 2554 } 2555 #endif 2556 bzero(&hdr_old, sizeof(hdr_old)); 2557 if (do_timestamp) { 2558 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2559 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2560 } 2561 hdr_old.bh_datalen = pktlen; 2562 hdr_old.bh_hdrlen = hdrlen; 2563 hdr_old.bh_caplen = caplen; 2564 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2565 sizeof(hdr_old)); 2566 goto copy; 2567 } 2568 #endif 2569 2570 /* 2571 * Append the bpf header. Note we append the actual header size, but 2572 * move forward the length of the header plus padding. 2573 */ 2574 bzero(&hdr, sizeof(hdr)); 2575 if (do_timestamp) 2576 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2577 hdr.bh_datalen = pktlen; 2578 hdr.bh_hdrlen = hdrlen; 2579 hdr.bh_caplen = caplen; 2580 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2581 2582 /* 2583 * Copy the packet data into the store buffer and update its length. 2584 */ 2585 #ifndef BURN_BRIDGES 2586 copy: 2587 #endif 2588 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2589 d->bd_slen = curlen + totlen; 2590 2591 if (do_wakeup) 2592 bpf_wakeup(d); 2593 } 2594 2595 /* 2596 * Free buffers currently in use by a descriptor. 2597 * Called on close. 2598 */ 2599 static void 2600 bpfd_free(epoch_context_t ctx) 2601 { 2602 struct bpf_d *d; 2603 struct bpf_program_buffer *p; 2604 2605 /* 2606 * We don't need to lock out interrupts since this descriptor has 2607 * been detached from its interface and it yet hasn't been marked 2608 * free. 2609 */ 2610 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2611 bpf_free(d); 2612 if (d->bd_rfilter != NULL) { 2613 p = __containerof((void *)d->bd_rfilter, 2614 struct bpf_program_buffer, buffer); 2615 #ifdef BPF_JITTER 2616 p->func = d->bd_bfilter; 2617 #endif 2618 bpf_program_buffer_free(&p->epoch_ctx); 2619 } 2620 if (d->bd_wfilter != NULL) { 2621 p = __containerof((void *)d->bd_wfilter, 2622 struct bpf_program_buffer, buffer); 2623 #ifdef BPF_JITTER 2624 p->func = NULL; 2625 #endif 2626 bpf_program_buffer_free(&p->epoch_ctx); 2627 } 2628 2629 mtx_destroy(&d->bd_lock); 2630 counter_u64_free(d->bd_rcount); 2631 counter_u64_free(d->bd_dcount); 2632 counter_u64_free(d->bd_fcount); 2633 counter_u64_free(d->bd_wcount); 2634 counter_u64_free(d->bd_wfcount); 2635 counter_u64_free(d->bd_wdcount); 2636 counter_u64_free(d->bd_zcopy); 2637 free(d, M_BPF); 2638 } 2639 2640 /* 2641 * Attach a tap point to bpf. 2642 * XXX: with current KPI it is consumer's responsibility to avoid duplicates. 2643 */ 2644 struct bpf_if * 2645 bpf_attach(const char *name, u_int dlt, u_int hdrlen, 2646 const struct bif_methods *methods, void *sc) 2647 { 2648 struct bpf_if *bp; 2649 2650 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2651 2652 CK_LIST_INIT(&bp->bif_dlist); 2653 CK_LIST_INIT(&bp->bif_wlist); 2654 bp->bif_dlt = dlt; 2655 bp->bif_hdrlen = hdrlen; 2656 bp->bif_softc = sc; 2657 bp->bif_name = name; 2658 bp->bif_methods = methods; 2659 refcount_init(&bp->bif_refcnt, 1); 2660 BPF_LOCK(); 2661 LIST_INSERT_HEAD(&V_bpf_iflist, bp, bif_next); 2662 BPF_UNLOCK(); 2663 2664 return (bp); 2665 } 2666 2667 #ifdef VIMAGE 2668 /* 2669 * Detach descriptors on interface's vmove event. 2670 * XXXGL: shouldn't be a special case, but a full detach. 2671 */ 2672 void 2673 bpf_ifdetach(struct ifnet *ifp) 2674 { 2675 struct bpf_if *bp; 2676 struct bpf_d *d; 2677 2678 BPF_LOCK(); 2679 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2680 /* XXXGL: assuming softc is ifnet here */ 2681 if (bp->bif_softc != ifp) 2682 continue; 2683 2684 /* Detach common descriptors */ 2685 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2686 bpf_detachd(d, true); 2687 } 2688 2689 /* Detach writer-only descriptors */ 2690 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2691 bpf_detachd(d, true); 2692 } 2693 } 2694 BPF_UNLOCK(); 2695 } 2696 #endif 2697 2698 /* 2699 * Detach bpf tap point. This involves detaching each descriptor associated 2700 * with the interface. Notify each descriptor as it's detached so that any 2701 * sleepers wake up and get ENXIO. 2702 */ 2703 void 2704 bpf_detach(struct bpf_if *bp) 2705 { 2706 struct bpf_d *d; 2707 2708 BPF_LOCK(); 2709 LIST_REMOVE(bp, bif_next); 2710 2711 CTR3(KTR_NET, "%s: sheduling free for encap %d for bp %p", 2712 __func__, bp->bif_dlt, bp); 2713 2714 /* Detach common descriptors */ 2715 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2716 bpf_detachd(d, true); 2717 } 2718 2719 /* Detach writer-only descriptors */ 2720 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2721 bpf_detachd(d, true); 2722 } 2723 bpfif_rele(bp); 2724 BPF_UNLOCK(); 2725 } 2726 2727 #ifdef VIMAGE 2728 /* 2729 * Move bpf to a different VNET. This KPI is a crutch to support if_vmove 2730 * and is not supposed to be used anywhere else. 2731 */ 2732 void 2733 bpf_vmove(struct bpf_if *bp) 2734 { 2735 2736 BPF_LOCK(); 2737 LIST_REMOVE(bp, bif_next); 2738 LIST_INSERT_HEAD(&V_bpf_iflist, bp, bif_next); 2739 BPF_UNLOCK(); 2740 } 2741 #endif 2742 2743 bool 2744 bpf_peers_present_if(struct ifnet *ifp) 2745 { 2746 return (bpf_peers_present(ifp->if_bpf)); 2747 } 2748 2749 /* 2750 * Get a list of available data link type of the tap point. If a tap point 2751 * attaches more than one time, it is supposed to attach with different DLTs 2752 * but with the same name pointer. 2753 */ 2754 static int 2755 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2756 { 2757 const char *name; 2758 struct bpf_if *bp; 2759 u_int *lst; 2760 int error, n, n1; 2761 2762 BPF_LOCK_ASSERT(); 2763 2764 name = d->bd_bif->bif_name; 2765 n1 = 0; 2766 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2767 if (bp->bif_name == name) 2768 n1++; 2769 } 2770 if (bfl->bfl_list == NULL) { 2771 bfl->bfl_len = n1; 2772 return (0); 2773 } 2774 if (n1 > bfl->bfl_len) 2775 return (ENOMEM); 2776 2777 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2778 n = 0; 2779 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2780 if (bp->bif_name != name) 2781 continue; 2782 lst[n++] = bp->bif_dlt; 2783 } 2784 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2785 free(lst, M_TEMP); 2786 bfl->bfl_len = n; 2787 return (error); 2788 } 2789 2790 /* 2791 * Set the data link type of a BPF descriptor. The convention is that 2792 * application first do BIOCSETIF and then BIOCSETDLT, thus the descriptor 2793 * is supposed to be already attached. Only one kernel facility provides 2794 * tapping points with same name but different DLT - ieee80211_radiotap. 2795 * 2796 * XXXGL: this function definitely looks suspicious, e.g. it clearly doesn't 2797 * clear promisc on the old bpf_if. The convention about reference counting 2798 * is also unclear. 2799 */ 2800 static int 2801 bpf_setdlt(struct bpf_d *d, u_int dlt) 2802 { 2803 int error, opromisc; 2804 const char *name; 2805 struct bpf_if *bp; 2806 2807 BPF_LOCK_ASSERT(); 2808 MPASS(d->bd_bif != NULL); 2809 2810 /* 2811 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2812 * changed while we hold global lock. 2813 */ 2814 if (d->bd_bif->bif_dlt == dlt) 2815 return (0); 2816 2817 name = d->bd_bif->bif_name; 2818 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2819 if (bp->bif_name == name && bp->bif_dlt == dlt) 2820 break; 2821 } 2822 if (bp == NULL) 2823 return (EINVAL); 2824 2825 opromisc = d->bd_promisc; 2826 bpf_attachd(d, bp); 2827 if (opromisc) { 2828 error = bp->bif_methods->bif_promisc(bp->bif_softc, true); 2829 if (error) 2830 printf("%s: bif_promisc on %s failed (%d)\n", 2831 __func__, bp->bif_name, error); 2832 else 2833 d->bd_promisc = 1; 2834 } 2835 return (0); 2836 } 2837 2838 static void 2839 bpf_drvinit(void *unused) 2840 { 2841 struct cdev *dev; 2842 2843 sx_init(&bpf_sx, "bpf global lock"); 2844 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2845 /* For compatibility */ 2846 make_dev_alias(dev, "bpf0"); 2847 } 2848 2849 /* 2850 * Zero out the various packet counters associated with all of the bpf 2851 * descriptors. At some point, we will probably want to get a bit more 2852 * granular and allow the user to specify descriptors to be zeroed. 2853 */ 2854 static void 2855 bpf_zero_counters(void) 2856 { 2857 struct bpf_if *bp; 2858 struct bpf_d *bd; 2859 2860 BPF_LOCK(); 2861 /* 2862 * We are protected by global lock here, interfaces and 2863 * descriptors can not be deleted while we hold it. 2864 */ 2865 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2866 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2867 counter_u64_zero(bd->bd_rcount); 2868 counter_u64_zero(bd->bd_dcount); 2869 counter_u64_zero(bd->bd_fcount); 2870 counter_u64_zero(bd->bd_wcount); 2871 counter_u64_zero(bd->bd_wfcount); 2872 counter_u64_zero(bd->bd_zcopy); 2873 } 2874 } 2875 BPF_UNLOCK(); 2876 } 2877 2878 /* 2879 * Fill filter statistics 2880 */ 2881 static void 2882 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2883 { 2884 2885 BPF_LOCK_ASSERT(); 2886 bzero(d, sizeof(*d)); 2887 d->bd_structsize = sizeof(*d); 2888 d->bd_immediate = bd->bd_flags & BPFD_IMMEDIATE ? 1 : 0; 2889 d->bd_promisc = bd->bd_promisc; 2890 d->bd_hdrcmplt = bd->bd_flags & BPFD_HDRCMPLT ? 1 : 0; 2891 d->bd_direction = bd->bd_direction; 2892 d->bd_feedback = bd->bd_flags & BPFD_FEEDBACK ? 1 : 0; 2893 d->bd_async = bd->bd_flags & BPFD_ASYNC ? 1 : 0; 2894 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2895 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2896 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2897 d->bd_sig = bd->bd_sig; 2898 d->bd_slen = bd->bd_slen; 2899 d->bd_hlen = bd->bd_hlen; 2900 d->bd_bufsize = bd->bd_bufsize; 2901 d->bd_pid = bd->bd_pid; 2902 strlcpy(d->bd_ifname, bd->bd_bif->bif_name, sizeof(d->bd_ifname)); 2903 d->bd_locked = bd->bd_flags & BPFD_LOCKED ? 1 : 0; 2904 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2905 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2906 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2907 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2908 d->bd_bufmode = bd->bd_bufmode; 2909 } 2910 2911 /* 2912 * Handle `netstat -B' stats request 2913 */ 2914 static int 2915 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2916 { 2917 static const struct xbpf_d zerostats; 2918 struct xbpf_d *xbdbuf, *xbd, tempstats; 2919 u_int bpfd_cnt, index; 2920 int error; 2921 struct bpf_if *bp; 2922 struct bpf_d *bd; 2923 2924 /* 2925 * XXX This is not technically correct. It is possible for non 2926 * privileged users to open bpf devices. It would make sense 2927 * if the users who opened the devices were able to retrieve 2928 * the statistics for them, too. 2929 */ 2930 error = priv_check(req->td, PRIV_NET_BPF); 2931 if (error) 2932 return (error); 2933 /* 2934 * Check to see if the user is requesting that the counters be 2935 * zeroed out. Explicitly check that the supplied data is zeroed, 2936 * as we aren't allowing the user to set the counters currently. 2937 */ 2938 if (req->newptr != NULL) { 2939 if (req->newlen != sizeof(tempstats)) 2940 return (EINVAL); 2941 memset(&tempstats, 0, sizeof(tempstats)); 2942 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2943 if (error) 2944 return (error); 2945 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2946 return (EINVAL); 2947 bpf_zero_counters(); 2948 return (0); 2949 } 2950 bpfd_cnt = 0; 2951 BPF_LOCK(); 2952 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2953 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) 2954 bpfd_cnt++; 2955 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) 2956 bpfd_cnt++; 2957 } 2958 if (bpfd_cnt == 0 || req->oldptr == NULL) { 2959 BPF_UNLOCK(); 2960 return (SYSCTL_OUT(req, 0, bpfd_cnt * sizeof(*xbd))); 2961 } 2962 if (req->oldlen < bpfd_cnt * sizeof(*xbd)) { 2963 BPF_UNLOCK(); 2964 return (ENOMEM); 2965 } 2966 xbdbuf = malloc(bpfd_cnt * sizeof(*xbd), M_BPF, M_WAITOK); 2967 index = 0; 2968 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2969 /* Send writers-only first */ 2970 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2971 MPASS(index <= bpfd_cnt); 2972 xbd = &xbdbuf[index++]; 2973 bpfstats_fill_xbpf(xbd, bd); 2974 } 2975 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2976 MPASS(index <= bpfd_cnt); 2977 xbd = &xbdbuf[index++]; 2978 bpfstats_fill_xbpf(xbd, bd); 2979 } 2980 } 2981 BPF_UNLOCK(); 2982 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2983 free(xbdbuf, M_BPF); 2984 return (error); 2985 } 2986 2987 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, bpf_drvinit, NULL); 2988 2989 #else /* !DEV_BPF && !NETGRAPH_BPF */ 2990 2991 /* 2992 * NOP stubs to allow bpf-using drivers to load and function. 2993 * 2994 * A 'better' implementation would allow the core bpf functionality 2995 * to be loaded at runtime. 2996 */ 2997 2998 void 2999 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 3000 { 3001 } 3002 3003 void 3004 bpf_tap_if(if_t ifp, u_char *pkt, u_int pktlen) 3005 { 3006 } 3007 3008 void 3009 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3010 { 3011 } 3012 3013 void 3014 bpf_mtap_if(if_t ifp, struct mbuf *m) 3015 { 3016 } 3017 3018 void 3019 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3020 { 3021 } 3022 3023 void 3024 bpf_mtap2_if(if_t ifp, void *data, u_int dlen, struct mbuf *m) 3025 { 3026 } 3027 3028 void 3029 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3030 { 3031 static const struct bpfd_list dead_bpf_if = CK_LIST_HEAD_INITIALIZER(); 3032 3033 ifp->if_bpf = __DECONST(struct bpf_if *, &dead_bpf_if); 3034 } 3035 3036 void 3037 bpfdetach(struct ifnet *ifp) 3038 { 3039 } 3040 3041 bool 3042 bpf_peers_present_if(struct ifnet *ifp) 3043 { 3044 return (false); 3045 } 3046 3047 u_int 3048 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3049 { 3050 return (-1); /* "no filter" behaviour */ 3051 } 3052 3053 int 3054 bpf_validate(const struct bpf_insn *f, int len) 3055 { 3056 return (0); /* false */ 3057 } 3058 3059 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3060