bpf.c revision 1.215
1 /* $NetBSD: bpf.c,v 1.215 2017/02/19 13:58:42 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from the Stanford/CMU enet packet filter, 8 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 9 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 10 * Berkeley Laboratory. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 37 * static char rcsid[] = 38 * "Header: bpf.c,v 1.67 96/09/26 22:00:52 leres Exp "; 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: bpf.c,v 1.215 2017/02/19 13:58:42 christos Exp $"); 43 44 #if defined(_KERNEL_OPT) 45 #include "opt_bpf.h" 46 #include "sl.h" 47 #include "strip.h" 48 #include "opt_net_mpsafe.h" 49 #endif 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/mbuf.h> 54 #include <sys/buf.h> 55 #include <sys/time.h> 56 #include <sys/proc.h> 57 #include <sys/ioctl.h> 58 #include <sys/conf.h> 59 #include <sys/vnode.h> 60 #include <sys/queue.h> 61 #include <sys/stat.h> 62 #include <sys/module.h> 63 #include <sys/atomic.h> 64 #include <sys/cpu.h> 65 66 #include <sys/file.h> 67 #include <sys/filedesc.h> 68 #include <sys/tty.h> 69 #include <sys/uio.h> 70 71 #include <sys/protosw.h> 72 #include <sys/socket.h> 73 #include <sys/errno.h> 74 #include <sys/kernel.h> 75 #include <sys/poll.h> 76 #include <sys/sysctl.h> 77 #include <sys/kauth.h> 78 #include <sys/syslog.h> 79 #include <sys/percpu.h> 80 #include <sys/pserialize.h> 81 #include <sys/lwp.h> 82 83 #include <net/if.h> 84 #include <net/slip.h> 85 86 #include <net/bpf.h> 87 #include <net/bpfdesc.h> 88 #include <net/bpfjit.h> 89 90 #include <net/if_arc.h> 91 #include <net/if_ether.h> 92 93 #include <netinet/in.h> 94 #include <netinet/if_inarp.h> 95 96 97 #include <compat/sys/sockio.h> 98 99 #ifndef BPF_BUFSIZE 100 /* 101 * 4096 is too small for FDDI frames. 8192 is too small for gigabit Ethernet 102 * jumbos (circa 9k), ATM, or Intel gig/10gig ethernet jumbos (16k). 103 */ 104 # define BPF_BUFSIZE 32768 105 #endif 106 107 #define PRINET 26 /* interruptible */ 108 109 /* 110 * The default read buffer size, and limit for BIOCSBLEN, is sysctl'able. 111 * XXX the default values should be computed dynamically based 112 * on available memory size and available mbuf clusters. 113 */ 114 static int bpf_bufsize = BPF_BUFSIZE; 115 static int bpf_maxbufsize = BPF_DFLTBUFSIZE; /* XXX set dynamically, see above */ 116 static bool bpf_jit = false; 117 118 struct bpfjit_ops bpfjit_module_ops = { 119 .bj_generate_code = NULL, 120 .bj_free_code = NULL 121 }; 122 123 /* 124 * Global BPF statistics returned by net.bpf.stats sysctl. 125 */ 126 static struct percpu *bpf_gstats_percpu; /* struct bpf_stat */ 127 128 #define BPF_STATINC(id) \ 129 { \ 130 struct bpf_stat *__stats = \ 131 percpu_getref(bpf_gstats_percpu); \ 132 __stats->bs_##id++; \ 133 percpu_putref(bpf_gstats_percpu); \ 134 } 135 136 /* 137 * Locking notes: 138 * - bpf_mtx (adaptive mutex) protects: 139 * - Gobal lists: bpf_iflist and bpf_dlist 140 * - struct bpf_if 141 * - bpf_close 142 * - bpf_psz (pserialize) 143 * - struct bpf_d has two mutexes: 144 * - bd_buf_mtx (spin mutex) protects the buffers that can be accessed 145 * on packet tapping 146 * - bd_mtx (adaptive mutex) protects member variables other than the buffers 147 * - Locking order: bpf_mtx => bpf_d#bd_mtx => bpf_d#bd_buf_mtx 148 * - struct bpf_d obtained via fp->f_bpf in bpf_read and bpf_write is 149 * never freed because struct bpf_d is only freed in bpf_close and 150 * bpf_close never be called while executing bpf_read and bpf_write 151 * - A filter that is assigned to bpf_d can be replaced with another filter 152 * while tapping packets, so it needs to be done atomically 153 * - struct bpf_d is iterated on bpf_dlist with psz 154 * - struct bpf_if is iterated on bpf_iflist with psz or psref 155 */ 156 /* 157 * Use a mutex to avoid a race condition between gathering the stats/peers 158 * and opening/closing the device. 159 */ 160 static kmutex_t bpf_mtx; 161 162 static struct psref_class *bpf_psref_class __read_mostly; 163 static pserialize_t bpf_psz; 164 165 static inline void 166 bpf_if_acquire(struct bpf_if *bp, struct psref *psref) 167 { 168 169 psref_acquire(psref, &bp->bif_psref, bpf_psref_class); 170 } 171 172 static inline void 173 bpf_if_release(struct bpf_if *bp, struct psref *psref) 174 { 175 176 psref_release(psref, &bp->bif_psref, bpf_psref_class); 177 } 178 179 /* 180 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 181 * bpf_dtab holds the descriptors, indexed by minor device # 182 */ 183 static struct pslist_head bpf_iflist; 184 static struct pslist_head bpf_dlist; 185 186 /* Macros for bpf_d on bpf_dlist */ 187 #define BPF_DLIST_WRITER_INSERT_HEAD(__d) \ 188 PSLIST_WRITER_INSERT_HEAD(&bpf_dlist, (__d), bd_bpf_dlist_entry) 189 #define BPF_DLIST_READER_FOREACH(__d) \ 190 PSLIST_READER_FOREACH((__d), &bpf_dlist, struct bpf_d, \ 191 bd_bpf_dlist_entry) 192 #define BPF_DLIST_WRITER_FOREACH(__d) \ 193 PSLIST_WRITER_FOREACH((__d), &bpf_dlist, struct bpf_d, \ 194 bd_bpf_dlist_entry) 195 #define BPF_DLIST_ENTRY_INIT(__d) \ 196 PSLIST_ENTRY_INIT((__d), bd_bpf_dlist_entry) 197 #define BPF_DLIST_WRITER_REMOVE(__d) \ 198 PSLIST_WRITER_REMOVE((__d), bd_bpf_dlist_entry) 199 #define BPF_DLIST_ENTRY_DESTROY(__d) \ 200 PSLIST_ENTRY_DESTROY((__d), bd_bpf_dlist_entry) 201 202 /* Macros for bpf_if on bpf_iflist */ 203 #define BPF_IFLIST_WRITER_INSERT_HEAD(__bp) \ 204 PSLIST_WRITER_INSERT_HEAD(&bpf_iflist, (__bp), bif_iflist_entry) 205 #define BPF_IFLIST_READER_FOREACH(__bp) \ 206 PSLIST_READER_FOREACH((__bp), &bpf_iflist, struct bpf_if, \ 207 bif_iflist_entry) 208 #define BPF_IFLIST_WRITER_FOREACH(__bp) \ 209 PSLIST_WRITER_FOREACH((__bp), &bpf_iflist, struct bpf_if, \ 210 bif_iflist_entry) 211 #define BPF_IFLIST_WRITER_REMOVE(__bp) \ 212 PSLIST_WRITER_REMOVE((__bp), bif_iflist_entry) 213 #define BPF_IFLIST_ENTRY_INIT(__bp) \ 214 PSLIST_ENTRY_INIT((__bp), bif_iflist_entry) 215 #define BPF_IFLIST_ENTRY_DESTROY(__bp) \ 216 PSLIST_ENTRY_DESTROY((__bp), bif_iflist_entry) 217 218 /* Macros for bpf_d on bpf_if#bif_dlist_pslist */ 219 #define BPFIF_DLIST_READER_FOREACH(__d, __bp) \ 220 PSLIST_READER_FOREACH((__d), &(__bp)->bif_dlist_head, struct bpf_d, \ 221 bd_bif_dlist_entry) 222 #define BPFIF_DLIST_WRITER_INSERT_HEAD(__bp, __d) \ 223 PSLIST_WRITER_INSERT_HEAD(&(__bp)->bif_dlist_head, (__d), \ 224 bd_bif_dlist_entry) 225 #define BPFIF_DLIST_WRITER_REMOVE(__d) \ 226 PSLIST_WRITER_REMOVE((__d), bd_bif_dlist_entry) 227 #define BPFIF_DLIST_ENTRY_INIT(__d) \ 228 PSLIST_ENTRY_INIT((__d), bd_bif_dlist_entry) 229 #define BPFIF_DLIST_READER_EMPTY(__bp) \ 230 (PSLIST_READER_FIRST(&(__bp)->bif_dlist_head, struct bpf_d, \ 231 bd_bif_dlist_entry) == NULL) 232 #define BPFIF_DLIST_WRITER_EMPTY(__bp) \ 233 (PSLIST_WRITER_FIRST(&(__bp)->bif_dlist_head, struct bpf_d, \ 234 bd_bif_dlist_entry) == NULL) 235 #define BPFIF_DLIST_ENTRY_DESTROY(__d) \ 236 PSLIST_ENTRY_DESTROY((__d), bd_bif_dlist_entry) 237 238 static int bpf_allocbufs(struct bpf_d *); 239 static void bpf_deliver(struct bpf_if *, 240 void *(*cpfn)(void *, const void *, size_t), 241 void *, u_int, u_int, const bool); 242 static void bpf_freed(struct bpf_d *); 243 static void bpf_free_filter(struct bpf_filter *); 244 static void bpf_ifname(struct ifnet *, struct ifreq *); 245 static void *bpf_mcpy(void *, const void *, size_t); 246 static int bpf_movein(struct uio *, int, uint64_t, 247 struct mbuf **, struct sockaddr *); 248 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 249 static void bpf_detachd(struct bpf_d *); 250 static int bpf_setif(struct bpf_d *, struct ifreq *); 251 static int bpf_setf(struct bpf_d *, struct bpf_program *); 252 static void bpf_timed_out(void *); 253 static inline void 254 bpf_wakeup(struct bpf_d *); 255 static int bpf_hdrlen(struct bpf_d *); 256 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 257 void *(*)(void *, const void *, size_t), struct timespec *); 258 static void reset_d(struct bpf_d *); 259 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 260 static int bpf_setdlt(struct bpf_d *, u_int); 261 262 static int bpf_read(struct file *, off_t *, struct uio *, kauth_cred_t, 263 int); 264 static int bpf_write(struct file *, off_t *, struct uio *, kauth_cred_t, 265 int); 266 static int bpf_ioctl(struct file *, u_long, void *); 267 static int bpf_poll(struct file *, int); 268 static int bpf_stat(struct file *, struct stat *); 269 static int bpf_close(struct file *); 270 static int bpf_kqfilter(struct file *, struct knote *); 271 static void bpf_softintr(void *); 272 273 static const struct fileops bpf_fileops = { 274 .fo_read = bpf_read, 275 .fo_write = bpf_write, 276 .fo_ioctl = bpf_ioctl, 277 .fo_fcntl = fnullop_fcntl, 278 .fo_poll = bpf_poll, 279 .fo_stat = bpf_stat, 280 .fo_close = bpf_close, 281 .fo_kqfilter = bpf_kqfilter, 282 .fo_restart = fnullop_restart, 283 }; 284 285 dev_type_open(bpfopen); 286 287 const struct cdevsw bpf_cdevsw = { 288 .d_open = bpfopen, 289 .d_close = noclose, 290 .d_read = noread, 291 .d_write = nowrite, 292 .d_ioctl = noioctl, 293 .d_stop = nostop, 294 .d_tty = notty, 295 .d_poll = nopoll, 296 .d_mmap = nommap, 297 .d_kqfilter = nokqfilter, 298 .d_discard = nodiscard, 299 .d_flag = D_OTHER 300 }; 301 302 bpfjit_func_t 303 bpf_jit_generate(bpf_ctx_t *bc, void *code, size_t size) 304 { 305 306 membar_consumer(); 307 if (bpfjit_module_ops.bj_generate_code != NULL) { 308 return bpfjit_module_ops.bj_generate_code(bc, code, size); 309 } 310 return NULL; 311 } 312 313 void 314 bpf_jit_freecode(bpfjit_func_t jcode) 315 { 316 KASSERT(bpfjit_module_ops.bj_free_code != NULL); 317 bpfjit_module_ops.bj_free_code(jcode); 318 } 319 320 static int 321 bpf_movein(struct uio *uio, int linktype, uint64_t mtu, struct mbuf **mp, 322 struct sockaddr *sockp) 323 { 324 struct mbuf *m; 325 int error; 326 size_t len; 327 size_t hlen; 328 size_t align; 329 330 /* 331 * Build a sockaddr based on the data link layer type. 332 * We do this at this level because the ethernet header 333 * is copied directly into the data field of the sockaddr. 334 * In the case of SLIP, there is no header and the packet 335 * is forwarded as is. 336 * Also, we are careful to leave room at the front of the mbuf 337 * for the link level header. 338 */ 339 switch (linktype) { 340 341 case DLT_SLIP: 342 sockp->sa_family = AF_INET; 343 hlen = 0; 344 align = 0; 345 break; 346 347 case DLT_PPP: 348 sockp->sa_family = AF_UNSPEC; 349 hlen = 0; 350 align = 0; 351 break; 352 353 case DLT_EN10MB: 354 sockp->sa_family = AF_UNSPEC; 355 /* XXX Would MAXLINKHDR be better? */ 356 /* 6(dst)+6(src)+2(type) */ 357 hlen = sizeof(struct ether_header); 358 align = 2; 359 break; 360 361 case DLT_ARCNET: 362 sockp->sa_family = AF_UNSPEC; 363 hlen = ARC_HDRLEN; 364 align = 5; 365 break; 366 367 case DLT_FDDI: 368 sockp->sa_family = AF_LINK; 369 /* XXX 4(FORMAC)+6(dst)+6(src) */ 370 hlen = 16; 371 align = 0; 372 break; 373 374 case DLT_ECONET: 375 sockp->sa_family = AF_UNSPEC; 376 hlen = 6; 377 align = 2; 378 break; 379 380 case DLT_NULL: 381 sockp->sa_family = AF_UNSPEC; 382 hlen = 0; 383 align = 0; 384 break; 385 386 default: 387 return (EIO); 388 } 389 390 len = uio->uio_resid; 391 /* 392 * If there aren't enough bytes for a link level header or the 393 * packet length exceeds the interface mtu, return an error. 394 */ 395 if (len - hlen > mtu) 396 return (EMSGSIZE); 397 398 /* 399 * XXX Avoid complicated buffer chaining --- 400 * bail if it won't fit in a single mbuf. 401 * (Take into account possible alignment bytes) 402 */ 403 if (len + align > MCLBYTES) 404 return (EIO); 405 406 m = m_gethdr(M_WAIT, MT_DATA); 407 m_reset_rcvif(m); 408 m->m_pkthdr.len = (int)(len - hlen); 409 if (len + align > MHLEN) { 410 m_clget(m, M_WAIT); 411 if ((m->m_flags & M_EXT) == 0) { 412 error = ENOBUFS; 413 goto bad; 414 } 415 } 416 417 /* Insure the data is properly aligned */ 418 if (align > 0) { 419 m->m_data += align; 420 m->m_len -= (int)align; 421 } 422 423 error = uiomove(mtod(m, void *), len, uio); 424 if (error) 425 goto bad; 426 if (hlen != 0) { 427 memcpy(sockp->sa_data, mtod(m, void *), hlen); 428 m->m_data += hlen; /* XXX */ 429 len -= hlen; 430 } 431 m->m_len = (int)len; 432 *mp = m; 433 return (0); 434 435 bad: 436 m_freem(m); 437 return (error); 438 } 439 440 /* 441 * Attach file to the bpf interface, i.e. make d listen on bp. 442 */ 443 static void 444 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 445 { 446 447 KASSERT(mutex_owned(&bpf_mtx)); 448 KASSERT(mutex_owned(d->bd_mtx)); 449 /* 450 * Point d at bp, and add d to the interface's list of listeners. 451 * Finally, point the driver's bpf cookie at the interface so 452 * it will divert packets to bpf. 453 */ 454 d->bd_bif = bp; 455 BPFIF_DLIST_WRITER_INSERT_HEAD(bp, d); 456 457 *bp->bif_driverp = bp; 458 } 459 460 /* 461 * Detach a file from its interface. 462 */ 463 static void 464 bpf_detachd(struct bpf_d *d) 465 { 466 struct bpf_if *bp; 467 468 KASSERT(mutex_owned(&bpf_mtx)); 469 KASSERT(mutex_owned(d->bd_mtx)); 470 471 bp = d->bd_bif; 472 /* 473 * Check if this descriptor had requested promiscuous mode. 474 * If so, turn it off. 475 */ 476 if (d->bd_promisc) { 477 int error __diagused; 478 479 d->bd_promisc = 0; 480 /* 481 * Take device out of promiscuous mode. Since we were 482 * able to enter promiscuous mode, we should be able 483 * to turn it off. But we can get an error if 484 * the interface was configured down, so only panic 485 * if we don't get an unexpected error. 486 */ 487 #ifndef NET_MPSAFE 488 KERNEL_LOCK(1, NULL); 489 #endif 490 error = ifpromisc(bp->bif_ifp, 0); 491 #ifndef NET_MPSAFE 492 KERNEL_UNLOCK_ONE(NULL); 493 #endif 494 #ifdef DIAGNOSTIC 495 if (error) 496 printf("%s: ifpromisc failed: %d", __func__, error); 497 #endif 498 } 499 500 /* Remove d from the interface's descriptor list. */ 501 BPFIF_DLIST_WRITER_REMOVE(d); 502 503 pserialize_perform(bpf_psz); 504 505 if (BPFIF_DLIST_WRITER_EMPTY(bp)) { 506 /* 507 * Let the driver know that there are no more listeners. 508 */ 509 *d->bd_bif->bif_driverp = NULL; 510 } 511 d->bd_bif = NULL; 512 } 513 514 static void 515 bpf_init(void) 516 { 517 518 mutex_init(&bpf_mtx, MUTEX_DEFAULT, IPL_NONE); 519 bpf_psz = pserialize_create(); 520 bpf_psref_class = psref_class_create("bpf", IPL_SOFTNET); 521 522 PSLIST_INIT(&bpf_iflist); 523 PSLIST_INIT(&bpf_dlist); 524 525 bpf_gstats_percpu = percpu_alloc(sizeof(struct bpf_stat)); 526 527 return; 528 } 529 530 /* 531 * bpfilterattach() is called at boot time. We don't need to do anything 532 * here, since any initialization will happen as part of module init code. 533 */ 534 /* ARGSUSED */ 535 void 536 bpfilterattach(int n) 537 { 538 539 } 540 541 /* 542 * Open ethernet device. Clones. 543 */ 544 /* ARGSUSED */ 545 int 546 bpfopen(dev_t dev, int flag, int mode, struct lwp *l) 547 { 548 struct bpf_d *d; 549 struct file *fp; 550 int error, fd; 551 552 /* falloc() will fill in the descriptor for us. */ 553 if ((error = fd_allocfile(&fp, &fd)) != 0) 554 return error; 555 556 d = kmem_zalloc(sizeof(*d), KM_SLEEP); 557 d->bd_bufsize = bpf_bufsize; 558 d->bd_seesent = 1; 559 d->bd_feedback = 0; 560 d->bd_pid = l->l_proc->p_pid; 561 #ifdef _LP64 562 if (curproc->p_flag & PK_32) 563 d->bd_compat32 = 1; 564 #endif 565 getnanotime(&d->bd_btime); 566 d->bd_atime = d->bd_mtime = d->bd_btime; 567 callout_init(&d->bd_callout, 0); 568 selinit(&d->bd_sel); 569 d->bd_sih = softint_establish(SOFTINT_CLOCK, bpf_softintr, d); 570 d->bd_jitcode = NULL; 571 d->bd_filter = NULL; 572 BPF_DLIST_ENTRY_INIT(d); 573 BPFIF_DLIST_ENTRY_INIT(d); 574 d->bd_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTNET); 575 d->bd_buf_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NET); 576 cv_init(&d->bd_cv, "bpf"); 577 578 mutex_enter(&bpf_mtx); 579 BPF_DLIST_WRITER_INSERT_HEAD(d); 580 mutex_exit(&bpf_mtx); 581 582 return fd_clone(fp, fd, flag, &bpf_fileops, d); 583 } 584 585 /* 586 * Close the descriptor by detaching it from its interface, 587 * deallocating its buffers, and marking it free. 588 */ 589 /* ARGSUSED */ 590 static int 591 bpf_close(struct file *fp) 592 { 593 struct bpf_d *d; 594 595 mutex_enter(&bpf_mtx); 596 597 if ((d = fp->f_bpf) == NULL) { 598 mutex_exit(&bpf_mtx); 599 return 0; 600 } 601 602 /* 603 * Refresh the PID associated with this bpf file. 604 */ 605 d->bd_pid = curproc->p_pid; 606 607 mutex_enter(d->bd_mtx); 608 if (d->bd_state == BPF_WAITING) 609 callout_halt(&d->bd_callout, d->bd_mtx); 610 d->bd_state = BPF_IDLE; 611 if (d->bd_bif) 612 bpf_detachd(d); 613 mutex_exit(d->bd_mtx); 614 615 BPF_DLIST_WRITER_REMOVE(d); 616 617 pserialize_perform(bpf_psz); 618 mutex_exit(&bpf_mtx); 619 620 BPFIF_DLIST_ENTRY_DESTROY(d); 621 BPF_DLIST_ENTRY_DESTROY(d); 622 fp->f_bpf = NULL; 623 bpf_freed(d); 624 callout_destroy(&d->bd_callout); 625 seldestroy(&d->bd_sel); 626 softint_disestablish(d->bd_sih); 627 mutex_obj_free(d->bd_mtx); 628 mutex_obj_free(d->bd_buf_mtx); 629 cv_destroy(&d->bd_cv); 630 631 kmem_free(d, sizeof(*d)); 632 633 return (0); 634 } 635 636 /* 637 * Rotate the packet buffers in descriptor d. Move the store buffer 638 * into the hold slot, and the free buffer into the store slot. 639 * Zero the length of the new store buffer. 640 */ 641 #define ROTATE_BUFFERS(d) \ 642 (d)->bd_hbuf = (d)->bd_sbuf; \ 643 (d)->bd_hlen = (d)->bd_slen; \ 644 (d)->bd_sbuf = (d)->bd_fbuf; \ 645 (d)->bd_slen = 0; \ 646 (d)->bd_fbuf = NULL; 647 /* 648 * bpfread - read next chunk of packets from buffers 649 */ 650 static int 651 bpf_read(struct file *fp, off_t *offp, struct uio *uio, 652 kauth_cred_t cred, int flags) 653 { 654 struct bpf_d *d = fp->f_bpf; 655 int timed_out; 656 int error; 657 658 getnanotime(&d->bd_atime); 659 /* 660 * Restrict application to use a buffer the same size as 661 * the kernel buffers. 662 */ 663 if (uio->uio_resid != d->bd_bufsize) 664 return (EINVAL); 665 666 mutex_enter(d->bd_mtx); 667 if (d->bd_state == BPF_WAITING) 668 callout_halt(&d->bd_callout, d->bd_buf_mtx); 669 timed_out = (d->bd_state == BPF_TIMED_OUT); 670 d->bd_state = BPF_IDLE; 671 mutex_exit(d->bd_mtx); 672 /* 673 * If the hold buffer is empty, then do a timed sleep, which 674 * ends when the timeout expires or when enough packets 675 * have arrived to fill the store buffer. 676 */ 677 mutex_enter(d->bd_buf_mtx); 678 while (d->bd_hbuf == NULL) { 679 if (fp->f_flag & FNONBLOCK) { 680 if (d->bd_slen == 0) { 681 error = EWOULDBLOCK; 682 goto out; 683 } 684 ROTATE_BUFFERS(d); 685 break; 686 } 687 688 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 689 /* 690 * A packet(s) either arrived since the previous 691 * read or arrived while we were asleep. 692 * Rotate the buffers and return what's here. 693 */ 694 ROTATE_BUFFERS(d); 695 break; 696 } 697 698 error = cv_timedwait_sig(&d->bd_cv, d->bd_buf_mtx, d->bd_rtout); 699 700 if (error == EINTR || error == ERESTART) 701 goto out; 702 703 if (error == EWOULDBLOCK) { 704 /* 705 * On a timeout, return what's in the buffer, 706 * which may be nothing. If there is something 707 * in the store buffer, we can rotate the buffers. 708 */ 709 if (d->bd_hbuf) 710 /* 711 * We filled up the buffer in between 712 * getting the timeout and arriving 713 * here, so we don't need to rotate. 714 */ 715 break; 716 717 if (d->bd_slen == 0) { 718 error = 0; 719 goto out; 720 } 721 ROTATE_BUFFERS(d); 722 break; 723 } 724 if (error != 0) 725 goto out; 726 } 727 /* 728 * At this point, we know we have something in the hold slot. 729 */ 730 mutex_exit(d->bd_buf_mtx); 731 732 /* 733 * Move data from hold buffer into user space. 734 * We know the entire buffer is transferred since 735 * we checked above that the read buffer is bpf_bufsize bytes. 736 */ 737 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 738 739 mutex_enter(d->bd_buf_mtx); 740 d->bd_fbuf = d->bd_hbuf; 741 d->bd_hbuf = NULL; 742 d->bd_hlen = 0; 743 out: 744 mutex_exit(d->bd_buf_mtx); 745 return (error); 746 } 747 748 749 /* 750 * If there are processes sleeping on this descriptor, wake them up. 751 */ 752 static inline void 753 bpf_wakeup(struct bpf_d *d) 754 { 755 756 mutex_enter(d->bd_buf_mtx); 757 cv_broadcast(&d->bd_cv); 758 mutex_exit(d->bd_buf_mtx); 759 760 if (d->bd_async) 761 softint_schedule(d->bd_sih); 762 selnotify(&d->bd_sel, 0, 0); 763 } 764 765 static void 766 bpf_softintr(void *cookie) 767 { 768 struct bpf_d *d; 769 770 d = cookie; 771 if (d->bd_async) 772 fownsignal(d->bd_pgid, SIGIO, 0, 0, NULL); 773 } 774 775 static void 776 bpf_timed_out(void *arg) 777 { 778 struct bpf_d *d = arg; 779 780 mutex_enter(d->bd_mtx); 781 if (d->bd_state == BPF_WAITING) { 782 d->bd_state = BPF_TIMED_OUT; 783 if (d->bd_slen != 0) 784 bpf_wakeup(d); 785 } 786 mutex_exit(d->bd_mtx); 787 } 788 789 790 static int 791 bpf_write(struct file *fp, off_t *offp, struct uio *uio, 792 kauth_cred_t cred, int flags) 793 { 794 struct bpf_d *d = fp->f_bpf; 795 struct bpf_if *bp; 796 struct ifnet *ifp; 797 struct mbuf *m, *mc; 798 int error; 799 static struct sockaddr_storage dst; 800 struct psref psref; 801 int bound; 802 803 m = NULL; /* XXX gcc */ 804 805 bound = curlwp_bind(); 806 mutex_enter(d->bd_mtx); 807 bp = d->bd_bif; 808 if (bp == NULL) { 809 mutex_exit(d->bd_mtx); 810 error = ENXIO; 811 goto out_bindx; 812 } 813 bpf_if_acquire(bp, &psref); 814 mutex_exit(d->bd_mtx); 815 816 getnanotime(&d->bd_mtime); 817 818 ifp = bp->bif_ifp; 819 if (if_is_deactivated(ifp)) { 820 error = ENXIO; 821 goto out; 822 } 823 824 if (uio->uio_resid == 0) { 825 error = 0; 826 goto out; 827 } 828 829 error = bpf_movein(uio, (int)bp->bif_dlt, ifp->if_mtu, &m, 830 (struct sockaddr *) &dst); 831 if (error) 832 goto out; 833 834 if (m->m_pkthdr.len > ifp->if_mtu) { 835 m_freem(m); 836 error = EMSGSIZE; 837 goto out; 838 } 839 840 if (d->bd_hdrcmplt) 841 dst.ss_family = pseudo_AF_HDRCMPLT; 842 843 if (d->bd_feedback) { 844 mc = m_dup(m, 0, M_COPYALL, M_NOWAIT); 845 if (mc != NULL) 846 m_set_rcvif(mc, ifp); 847 /* Set M_PROMISC for outgoing packets to be discarded. */ 848 if (1 /*d->bd_direction == BPF_D_INOUT*/) 849 m->m_flags |= M_PROMISC; 850 } else 851 mc = NULL; 852 853 error = if_output_lock(ifp, ifp, m, (struct sockaddr *) &dst, NULL); 854 855 if (mc != NULL) { 856 if (error == 0) 857 ifp->_if_input(ifp, mc); 858 else 859 m_freem(mc); 860 } 861 /* 862 * The driver frees the mbuf. 863 */ 864 out: 865 bpf_if_release(bp, &psref); 866 out_bindx: 867 curlwp_bindx(bound); 868 return error; 869 } 870 871 /* 872 * Reset a descriptor by flushing its packet buffer and clearing the 873 * receive and drop counts. 874 */ 875 static void 876 reset_d(struct bpf_d *d) 877 { 878 879 KASSERT(mutex_owned(d->bd_mtx)); 880 881 mutex_enter(d->bd_buf_mtx); 882 if (d->bd_hbuf) { 883 /* Free the hold buffer. */ 884 d->bd_fbuf = d->bd_hbuf; 885 d->bd_hbuf = NULL; 886 } 887 d->bd_slen = 0; 888 d->bd_hlen = 0; 889 d->bd_rcount = 0; 890 d->bd_dcount = 0; 891 d->bd_ccount = 0; 892 mutex_exit(d->bd_buf_mtx); 893 } 894 895 /* 896 * FIONREAD Check for read packet available. 897 * BIOCGBLEN Get buffer len [for read()]. 898 * BIOCSETF Set ethernet read filter. 899 * BIOCFLUSH Flush read packet buffer. 900 * BIOCPROMISC Put interface into promiscuous mode. 901 * BIOCGDLT Get link layer type. 902 * BIOCGETIF Get interface name. 903 * BIOCSETIF Set interface. 904 * BIOCSRTIMEOUT Set read timeout. 905 * BIOCGRTIMEOUT Get read timeout. 906 * BIOCGSTATS Get packet stats. 907 * BIOCIMMEDIATE Set immediate mode. 908 * BIOCVERSION Get filter language version. 909 * BIOCGHDRCMPLT Get "header already complete" flag. 910 * BIOCSHDRCMPLT Set "header already complete" flag. 911 * BIOCSFEEDBACK Set packet feedback mode. 912 * BIOCGFEEDBACK Get packet feedback mode. 913 * BIOCGSEESENT Get "see sent packets" mode. 914 * BIOCSSEESENT Set "see sent packets" mode. 915 */ 916 /* ARGSUSED */ 917 static int 918 bpf_ioctl(struct file *fp, u_long cmd, void *addr) 919 { 920 struct bpf_d *d = fp->f_bpf; 921 int error = 0; 922 923 /* 924 * Refresh the PID associated with this bpf file. 925 */ 926 d->bd_pid = curproc->p_pid; 927 #ifdef _LP64 928 if (curproc->p_flag & PK_32) 929 d->bd_compat32 = 1; 930 else 931 d->bd_compat32 = 0; 932 #endif 933 934 mutex_enter(d->bd_mtx); 935 if (d->bd_state == BPF_WAITING) 936 callout_halt(&d->bd_callout, d->bd_mtx); 937 d->bd_state = BPF_IDLE; 938 mutex_exit(d->bd_mtx); 939 940 switch (cmd) { 941 942 default: 943 error = EINVAL; 944 break; 945 946 /* 947 * Check for read packet available. 948 */ 949 case FIONREAD: 950 { 951 int n; 952 953 mutex_enter(d->bd_buf_mtx); 954 n = d->bd_slen; 955 if (d->bd_hbuf) 956 n += d->bd_hlen; 957 mutex_exit(d->bd_buf_mtx); 958 959 *(int *)addr = n; 960 break; 961 } 962 963 /* 964 * Get buffer len [for read()]. 965 */ 966 case BIOCGBLEN: 967 *(u_int *)addr = d->bd_bufsize; 968 break; 969 970 /* 971 * Set buffer length. 972 */ 973 case BIOCSBLEN: 974 /* 975 * Forbid to change the buffer length if buffers are already 976 * allocated. 977 */ 978 mutex_enter(d->bd_mtx); 979 mutex_enter(d->bd_buf_mtx); 980 if (d->bd_bif != NULL || d->bd_sbuf != NULL) 981 error = EINVAL; 982 else { 983 u_int size = *(u_int *)addr; 984 985 if (size > bpf_maxbufsize) 986 *(u_int *)addr = size = bpf_maxbufsize; 987 else if (size < BPF_MINBUFSIZE) 988 *(u_int *)addr = size = BPF_MINBUFSIZE; 989 d->bd_bufsize = size; 990 } 991 mutex_exit(d->bd_buf_mtx); 992 mutex_exit(d->bd_mtx); 993 break; 994 995 /* 996 * Set link layer read filter. 997 */ 998 case BIOCSETF: 999 error = bpf_setf(d, addr); 1000 break; 1001 1002 /* 1003 * Flush read packet buffer. 1004 */ 1005 case BIOCFLUSH: 1006 mutex_enter(d->bd_mtx); 1007 reset_d(d); 1008 mutex_exit(d->bd_mtx); 1009 break; 1010 1011 /* 1012 * Put interface into promiscuous mode. 1013 */ 1014 case BIOCPROMISC: 1015 mutex_enter(d->bd_mtx); 1016 if (d->bd_bif == NULL) { 1017 mutex_exit(d->bd_mtx); 1018 /* 1019 * No interface attached yet. 1020 */ 1021 error = EINVAL; 1022 break; 1023 } 1024 if (d->bd_promisc == 0) { 1025 #ifndef NET_MPSAFE 1026 KERNEL_LOCK(1, NULL); 1027 #endif 1028 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1029 #ifndef NET_MPSAFE 1030 KERNEL_UNLOCK_ONE(NULL); 1031 #endif 1032 if (error == 0) 1033 d->bd_promisc = 1; 1034 } 1035 mutex_exit(d->bd_mtx); 1036 break; 1037 1038 /* 1039 * Get device parameters. 1040 */ 1041 case BIOCGDLT: 1042 mutex_enter(d->bd_mtx); 1043 if (d->bd_bif == NULL) 1044 error = EINVAL; 1045 else 1046 *(u_int *)addr = d->bd_bif->bif_dlt; 1047 mutex_exit(d->bd_mtx); 1048 break; 1049 1050 /* 1051 * Get a list of supported device parameters. 1052 */ 1053 case BIOCGDLTLIST: 1054 mutex_enter(d->bd_mtx); 1055 if (d->bd_bif == NULL) 1056 error = EINVAL; 1057 else 1058 error = bpf_getdltlist(d, addr); 1059 mutex_exit(d->bd_mtx); 1060 break; 1061 1062 /* 1063 * Set device parameters. 1064 */ 1065 case BIOCSDLT: 1066 mutex_enter(&bpf_mtx); 1067 mutex_enter(d->bd_mtx); 1068 if (d->bd_bif == NULL) 1069 error = EINVAL; 1070 else 1071 error = bpf_setdlt(d, *(u_int *)addr); 1072 mutex_exit(d->bd_mtx); 1073 mutex_exit(&bpf_mtx); 1074 break; 1075 1076 /* 1077 * Set interface name. 1078 */ 1079 #ifdef OBIOCGETIF 1080 case OBIOCGETIF: 1081 #endif 1082 case BIOCGETIF: 1083 mutex_enter(d->bd_mtx); 1084 if (d->bd_bif == NULL) 1085 error = EINVAL; 1086 else 1087 bpf_ifname(d->bd_bif->bif_ifp, addr); 1088 mutex_exit(d->bd_mtx); 1089 break; 1090 1091 /* 1092 * Set interface. 1093 */ 1094 #ifdef OBIOCSETIF 1095 case OBIOCSETIF: 1096 #endif 1097 case BIOCSETIF: 1098 mutex_enter(&bpf_mtx); 1099 error = bpf_setif(d, addr); 1100 mutex_exit(&bpf_mtx); 1101 break; 1102 1103 /* 1104 * Set read timeout. 1105 */ 1106 case BIOCSRTIMEOUT: 1107 { 1108 struct timeval *tv = addr; 1109 1110 /* Compute number of ticks. */ 1111 d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick; 1112 if ((d->bd_rtout == 0) && (tv->tv_usec != 0)) 1113 d->bd_rtout = 1; 1114 break; 1115 } 1116 1117 #ifdef BIOCGORTIMEOUT 1118 /* 1119 * Get read timeout. 1120 */ 1121 case BIOCGORTIMEOUT: 1122 { 1123 struct timeval50 *tv = addr; 1124 1125 tv->tv_sec = d->bd_rtout / hz; 1126 tv->tv_usec = (d->bd_rtout % hz) * tick; 1127 break; 1128 } 1129 #endif 1130 1131 #ifdef BIOCSORTIMEOUT 1132 /* 1133 * Set read timeout. 1134 */ 1135 case BIOCSORTIMEOUT: 1136 { 1137 struct timeval50 *tv = addr; 1138 1139 /* Compute number of ticks. */ 1140 d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick; 1141 if ((d->bd_rtout == 0) && (tv->tv_usec != 0)) 1142 d->bd_rtout = 1; 1143 break; 1144 } 1145 #endif 1146 1147 /* 1148 * Get read timeout. 1149 */ 1150 case BIOCGRTIMEOUT: 1151 { 1152 struct timeval *tv = addr; 1153 1154 tv->tv_sec = d->bd_rtout / hz; 1155 tv->tv_usec = (d->bd_rtout % hz) * tick; 1156 break; 1157 } 1158 /* 1159 * Get packet stats. 1160 */ 1161 case BIOCGSTATS: 1162 { 1163 struct bpf_stat *bs = addr; 1164 1165 bs->bs_recv = d->bd_rcount; 1166 bs->bs_drop = d->bd_dcount; 1167 bs->bs_capt = d->bd_ccount; 1168 break; 1169 } 1170 1171 case BIOCGSTATSOLD: 1172 { 1173 struct bpf_stat_old *bs = addr; 1174 1175 bs->bs_recv = d->bd_rcount; 1176 bs->bs_drop = d->bd_dcount; 1177 break; 1178 } 1179 1180 /* 1181 * Set immediate mode. 1182 */ 1183 case BIOCIMMEDIATE: 1184 d->bd_immediate = *(u_int *)addr; 1185 break; 1186 1187 case BIOCVERSION: 1188 { 1189 struct bpf_version *bv = addr; 1190 1191 bv->bv_major = BPF_MAJOR_VERSION; 1192 bv->bv_minor = BPF_MINOR_VERSION; 1193 break; 1194 } 1195 1196 case BIOCGHDRCMPLT: /* get "header already complete" flag */ 1197 *(u_int *)addr = d->bd_hdrcmplt; 1198 break; 1199 1200 case BIOCSHDRCMPLT: /* set "header already complete" flag */ 1201 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1202 break; 1203 1204 /* 1205 * Get "see sent packets" flag 1206 */ 1207 case BIOCGSEESENT: 1208 *(u_int *)addr = d->bd_seesent; 1209 break; 1210 1211 /* 1212 * Set "see sent" packets flag 1213 */ 1214 case BIOCSSEESENT: 1215 d->bd_seesent = *(u_int *)addr; 1216 break; 1217 1218 /* 1219 * Set "feed packets from bpf back to input" mode 1220 */ 1221 case BIOCSFEEDBACK: 1222 d->bd_feedback = *(u_int *)addr; 1223 break; 1224 1225 /* 1226 * Get "feed packets from bpf back to input" mode 1227 */ 1228 case BIOCGFEEDBACK: 1229 *(u_int *)addr = d->bd_feedback; 1230 break; 1231 1232 case FIONBIO: /* Non-blocking I/O */ 1233 /* 1234 * No need to do anything special as we use IO_NDELAY in 1235 * bpfread() as an indication of whether or not to block 1236 * the read. 1237 */ 1238 break; 1239 1240 case FIOASYNC: /* Send signal on receive packets */ 1241 d->bd_async = *(int *)addr; 1242 break; 1243 1244 case TIOCSPGRP: /* Process or group to send signals to */ 1245 case FIOSETOWN: 1246 error = fsetown(&d->bd_pgid, cmd, addr); 1247 break; 1248 1249 case TIOCGPGRP: 1250 case FIOGETOWN: 1251 error = fgetown(d->bd_pgid, cmd, addr); 1252 break; 1253 } 1254 return (error); 1255 } 1256 1257 /* 1258 * Set d's packet filter program to fp. If this file already has a filter, 1259 * free it and replace it. Returns EINVAL for bogus requests. 1260 */ 1261 static int 1262 bpf_setf(struct bpf_d *d, struct bpf_program *fp) 1263 { 1264 struct bpf_insn *fcode; 1265 bpfjit_func_t jcode; 1266 size_t flen, size = 0; 1267 struct bpf_filter *oldf, *newf; 1268 1269 jcode = NULL; 1270 flen = fp->bf_len; 1271 1272 if ((fp->bf_insns == NULL && flen) || flen > BPF_MAXINSNS) { 1273 return EINVAL; 1274 } 1275 1276 if (flen) { 1277 /* 1278 * Allocate the buffer, copy the byte-code from 1279 * userspace and validate it. 1280 */ 1281 size = flen * sizeof(*fp->bf_insns); 1282 fcode = kmem_alloc(size, KM_SLEEP); 1283 if (copyin(fp->bf_insns, fcode, size) != 0 || 1284 !bpf_validate(fcode, (int)flen)) { 1285 kmem_free(fcode, size); 1286 return EINVAL; 1287 } 1288 membar_consumer(); 1289 if (bpf_jit) 1290 jcode = bpf_jit_generate(NULL, fcode, flen); 1291 } else { 1292 fcode = NULL; 1293 } 1294 1295 newf = kmem_alloc(sizeof(*newf), KM_SLEEP); 1296 newf->bf_insn = fcode; 1297 newf->bf_size = size; 1298 newf->bf_jitcode = jcode; 1299 d->bd_jitcode = jcode; /* XXX just for kvm(3) users */ 1300 1301 /* Need to hold bpf_mtx for pserialize_perform */ 1302 mutex_enter(&bpf_mtx); 1303 mutex_enter(d->bd_mtx); 1304 oldf = d->bd_filter; 1305 d->bd_filter = newf; 1306 membar_producer(); 1307 reset_d(d); 1308 pserialize_perform(bpf_psz); 1309 mutex_exit(d->bd_mtx); 1310 mutex_exit(&bpf_mtx); 1311 1312 if (oldf != NULL) 1313 bpf_free_filter(oldf); 1314 1315 return 0; 1316 } 1317 1318 /* 1319 * Detach a file from its current interface (if attached at all) and attach 1320 * to the interface indicated by the name stored in ifr. 1321 * Return an errno or 0. 1322 */ 1323 static int 1324 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1325 { 1326 struct bpf_if *bp; 1327 char *cp; 1328 int unit_seen, i, error; 1329 1330 KASSERT(mutex_owned(&bpf_mtx)); 1331 /* 1332 * Make sure the provided name has a unit number, and default 1333 * it to '0' if not specified. 1334 * XXX This is ugly ... do this differently? 1335 */ 1336 unit_seen = 0; 1337 cp = ifr->ifr_name; 1338 cp[sizeof(ifr->ifr_name) - 1] = '\0'; /* sanity */ 1339 while (*cp++) 1340 if (*cp >= '0' && *cp <= '9') 1341 unit_seen = 1; 1342 if (!unit_seen) { 1343 /* Make sure to leave room for the '\0'. */ 1344 for (i = 0; i < (IFNAMSIZ - 1); ++i) { 1345 if ((ifr->ifr_name[i] >= 'a' && 1346 ifr->ifr_name[i] <= 'z') || 1347 (ifr->ifr_name[i] >= 'A' && 1348 ifr->ifr_name[i] <= 'Z')) 1349 continue; 1350 ifr->ifr_name[i] = '0'; 1351 } 1352 } 1353 1354 /* 1355 * Look through attached interfaces for the named one. 1356 */ 1357 BPF_IFLIST_WRITER_FOREACH(bp) { 1358 struct ifnet *ifp = bp->bif_ifp; 1359 1360 if (ifp == NULL || 1361 strcmp(ifp->if_xname, ifr->ifr_name) != 0) 1362 continue; 1363 /* skip additional entry */ 1364 if (bp->bif_driverp != &ifp->if_bpf) 1365 continue; 1366 /* 1367 * We found the requested interface. 1368 * Allocate the packet buffers if we need to. 1369 * If we're already attached to requested interface, 1370 * just flush the buffer. 1371 */ 1372 /* 1373 * bpf_allocbufs is called only here. bpf_mtx ensures that 1374 * no race condition happen on d->bd_sbuf. 1375 */ 1376 if (d->bd_sbuf == NULL) { 1377 error = bpf_allocbufs(d); 1378 if (error != 0) 1379 return (error); 1380 } 1381 mutex_enter(d->bd_mtx); 1382 if (bp != d->bd_bif) { 1383 if (d->bd_bif) 1384 /* 1385 * Detach if attached to something else. 1386 */ 1387 bpf_detachd(d); 1388 1389 bpf_attachd(d, bp); 1390 } 1391 reset_d(d); 1392 mutex_exit(d->bd_mtx); 1393 return (0); 1394 } 1395 /* Not found. */ 1396 return (ENXIO); 1397 } 1398 1399 /* 1400 * Copy the interface name to the ifreq. 1401 */ 1402 static void 1403 bpf_ifname(struct ifnet *ifp, struct ifreq *ifr) 1404 { 1405 memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ); 1406 } 1407 1408 static int 1409 bpf_stat(struct file *fp, struct stat *st) 1410 { 1411 struct bpf_d *d = fp->f_bpf; 1412 1413 (void)memset(st, 0, sizeof(*st)); 1414 mutex_enter(d->bd_mtx); 1415 st->st_dev = makedev(cdevsw_lookup_major(&bpf_cdevsw), d->bd_pid); 1416 st->st_atimespec = d->bd_atime; 1417 st->st_mtimespec = d->bd_mtime; 1418 st->st_ctimespec = st->st_birthtimespec = d->bd_btime; 1419 st->st_uid = kauth_cred_geteuid(fp->f_cred); 1420 st->st_gid = kauth_cred_getegid(fp->f_cred); 1421 st->st_mode = S_IFCHR; 1422 mutex_exit(d->bd_mtx); 1423 return 0; 1424 } 1425 1426 /* 1427 * Support for poll() system call 1428 * 1429 * Return true iff the specific operation will not block indefinitely - with 1430 * the assumption that it is safe to positively acknowledge a request for the 1431 * ability to write to the BPF device. 1432 * Otherwise, return false but make a note that a selnotify() must be done. 1433 */ 1434 static int 1435 bpf_poll(struct file *fp, int events) 1436 { 1437 struct bpf_d *d = fp->f_bpf; 1438 int revents; 1439 1440 /* 1441 * Refresh the PID associated with this bpf file. 1442 */ 1443 mutex_enter(&bpf_mtx); 1444 d->bd_pid = curproc->p_pid; 1445 1446 revents = events & (POLLOUT | POLLWRNORM); 1447 if (events & (POLLIN | POLLRDNORM)) { 1448 /* 1449 * An imitation of the FIONREAD ioctl code. 1450 */ 1451 mutex_enter(d->bd_mtx); 1452 if (d->bd_hlen != 0 || 1453 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1454 d->bd_slen != 0)) { 1455 revents |= events & (POLLIN | POLLRDNORM); 1456 } else { 1457 selrecord(curlwp, &d->bd_sel); 1458 /* Start the read timeout if necessary */ 1459 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1460 callout_reset(&d->bd_callout, d->bd_rtout, 1461 bpf_timed_out, d); 1462 d->bd_state = BPF_WAITING; 1463 } 1464 } 1465 mutex_exit(d->bd_mtx); 1466 } 1467 1468 mutex_exit(&bpf_mtx); 1469 return (revents); 1470 } 1471 1472 static void 1473 filt_bpfrdetach(struct knote *kn) 1474 { 1475 struct bpf_d *d = kn->kn_hook; 1476 1477 mutex_enter(d->bd_buf_mtx); 1478 SLIST_REMOVE(&d->bd_sel.sel_klist, kn, knote, kn_selnext); 1479 mutex_exit(d->bd_buf_mtx); 1480 } 1481 1482 static int 1483 filt_bpfread(struct knote *kn, long hint) 1484 { 1485 struct bpf_d *d = kn->kn_hook; 1486 int rv; 1487 1488 mutex_enter(d->bd_buf_mtx); 1489 kn->kn_data = d->bd_hlen; 1490 if (d->bd_immediate) 1491 kn->kn_data += d->bd_slen; 1492 rv = (kn->kn_data > 0); 1493 mutex_exit(d->bd_buf_mtx); 1494 return rv; 1495 } 1496 1497 static const struct filterops bpfread_filtops = 1498 { 1, NULL, filt_bpfrdetach, filt_bpfread }; 1499 1500 static int 1501 bpf_kqfilter(struct file *fp, struct knote *kn) 1502 { 1503 struct bpf_d *d = fp->f_bpf; 1504 struct klist *klist; 1505 1506 mutex_enter(d->bd_buf_mtx); 1507 switch (kn->kn_filter) { 1508 case EVFILT_READ: 1509 klist = &d->bd_sel.sel_klist; 1510 kn->kn_fop = &bpfread_filtops; 1511 break; 1512 1513 default: 1514 mutex_exit(d->bd_buf_mtx); 1515 return (EINVAL); 1516 } 1517 1518 kn->kn_hook = d; 1519 1520 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1521 mutex_exit(d->bd_buf_mtx); 1522 1523 return (0); 1524 } 1525 1526 /* 1527 * Copy data from an mbuf chain into a buffer. This code is derived 1528 * from m_copydata in sys/uipc_mbuf.c. 1529 */ 1530 static void * 1531 bpf_mcpy(void *dst_arg, const void *src_arg, size_t len) 1532 { 1533 const struct mbuf *m; 1534 u_int count; 1535 u_char *dst; 1536 1537 m = src_arg; 1538 dst = dst_arg; 1539 while (len > 0) { 1540 if (m == NULL) 1541 panic("bpf_mcpy"); 1542 count = min(m->m_len, len); 1543 memcpy(dst, mtod(m, const void *), count); 1544 m = m->m_next; 1545 dst += count; 1546 len -= count; 1547 } 1548 return dst_arg; 1549 } 1550 1551 /* 1552 * Dispatch a packet to all the listeners on interface bp. 1553 * 1554 * pkt pointer to the packet, either a data buffer or an mbuf chain 1555 * buflen buffer length, if pkt is a data buffer 1556 * cpfn a function that can copy pkt into the listener's buffer 1557 * pktlen length of the packet 1558 * rcv true if packet came in 1559 */ 1560 static inline void 1561 bpf_deliver(struct bpf_if *bp, void *(*cpfn)(void *, const void *, size_t), 1562 void *pkt, u_int pktlen, u_int buflen, const bool rcv) 1563 { 1564 uint32_t mem[BPF_MEMWORDS]; 1565 bpf_args_t args = { 1566 .pkt = (const uint8_t *)pkt, 1567 .wirelen = pktlen, 1568 .buflen = buflen, 1569 .mem = mem, 1570 .arg = NULL 1571 }; 1572 bool gottime = false; 1573 struct timespec ts; 1574 struct bpf_d *d; 1575 int s; 1576 1577 KASSERT(!cpu_intr_p()); 1578 1579 /* 1580 * Note that the IPL does not have to be raised at this point. 1581 * The only problem that could arise here is that if two different 1582 * interfaces shared any data. This is not the case. 1583 */ 1584 s = pserialize_read_enter(); 1585 BPFIF_DLIST_READER_FOREACH(d, bp) { 1586 u_int slen = 0; 1587 struct bpf_filter *filter; 1588 1589 if (!d->bd_seesent && !rcv) { 1590 continue; 1591 } 1592 atomic_inc_ulong(&d->bd_rcount); 1593 BPF_STATINC(recv); 1594 1595 filter = d->bd_filter; 1596 membar_datadep_consumer(); 1597 if (filter != NULL) { 1598 if (filter->bf_jitcode != NULL) 1599 slen = filter->bf_jitcode(NULL, &args); 1600 else 1601 slen = bpf_filter_ext(NULL, filter->bf_insn, 1602 &args); 1603 } 1604 1605 if (!slen) { 1606 continue; 1607 } 1608 if (!gottime) { 1609 gottime = true; 1610 nanotime(&ts); 1611 } 1612 /* Assume catchpacket doesn't sleep */ 1613 catchpacket(d, pkt, pktlen, slen, cpfn, &ts); 1614 } 1615 pserialize_read_exit(s); 1616 } 1617 1618 /* 1619 * Incoming linkage from device drivers. Process the packet pkt, of length 1620 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1621 * by each process' filter, and if accepted, stashed into the corresponding 1622 * buffer. 1623 */ 1624 static void 1625 _bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1626 { 1627 1628 bpf_deliver(bp, memcpy, pkt, pktlen, pktlen, true); 1629 } 1630 1631 /* 1632 * Incoming linkage from device drivers, when the head of the packet is in 1633 * a buffer, and the tail is in an mbuf chain. 1634 */ 1635 static void 1636 _bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1637 { 1638 u_int pktlen; 1639 struct mbuf mb; 1640 1641 /* Skip outgoing duplicate packets. */ 1642 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) { 1643 m->m_flags &= ~M_PROMISC; 1644 return; 1645 } 1646 1647 pktlen = m_length(m) + dlen; 1648 1649 /* 1650 * Craft on-stack mbuf suitable for passing to bpf_filter. 1651 * Note that we cut corners here; we only setup what's 1652 * absolutely needed--this mbuf should never go anywhere else. 1653 */ 1654 (void)memset(&mb, 0, sizeof(mb)); 1655 mb.m_next = m; 1656 mb.m_data = data; 1657 mb.m_len = dlen; 1658 1659 bpf_deliver(bp, bpf_mcpy, &mb, pktlen, 0, m->m_pkthdr.rcvif_index != 0); 1660 } 1661 1662 /* 1663 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1664 */ 1665 static void 1666 _bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1667 { 1668 void *(*cpfn)(void *, const void *, size_t); 1669 u_int pktlen, buflen; 1670 void *marg; 1671 1672 /* Skip outgoing duplicate packets. */ 1673 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) { 1674 m->m_flags &= ~M_PROMISC; 1675 return; 1676 } 1677 1678 pktlen = m_length(m); 1679 1680 if (pktlen == m->m_len) { 1681 cpfn = (void *)memcpy; 1682 marg = mtod(m, void *); 1683 buflen = pktlen; 1684 } else { 1685 cpfn = bpf_mcpy; 1686 marg = m; 1687 buflen = 0; 1688 } 1689 1690 bpf_deliver(bp, cpfn, marg, pktlen, buflen, m->m_pkthdr.rcvif_index != 0); 1691 } 1692 1693 /* 1694 * We need to prepend the address family as 1695 * a four byte field. Cons up a dummy header 1696 * to pacify bpf. This is safe because bpf 1697 * will only read from the mbuf (i.e., it won't 1698 * try to free it or keep a pointer a to it). 1699 */ 1700 static void 1701 _bpf_mtap_af(struct bpf_if *bp, uint32_t af, struct mbuf *m) 1702 { 1703 struct mbuf m0; 1704 1705 m0.m_flags = 0; 1706 m0.m_next = m; 1707 m0.m_len = 4; 1708 m0.m_data = (char *)⁡ 1709 1710 _bpf_mtap(bp, &m0); 1711 } 1712 1713 /* 1714 * Put the SLIP pseudo-"link header" in place. 1715 * Note this M_PREPEND() should never fail, 1716 * swince we know we always have enough space 1717 * in the input buffer. 1718 */ 1719 static void 1720 _bpf_mtap_sl_in(struct bpf_if *bp, u_char *chdr, struct mbuf **m) 1721 { 1722 u_char *hp; 1723 1724 M_PREPEND(*m, SLIP_HDRLEN, M_DONTWAIT); 1725 if (*m == NULL) 1726 return; 1727 1728 hp = mtod(*m, u_char *); 1729 hp[SLX_DIR] = SLIPDIR_IN; 1730 (void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); 1731 1732 _bpf_mtap(bp, *m); 1733 1734 m_adj(*m, SLIP_HDRLEN); 1735 } 1736 1737 /* 1738 * Put the SLIP pseudo-"link header" in 1739 * place. The compressed header is now 1740 * at the beginning of the mbuf. 1741 */ 1742 static void 1743 _bpf_mtap_sl_out(struct bpf_if *bp, u_char *chdr, struct mbuf *m) 1744 { 1745 struct mbuf m0; 1746 u_char *hp; 1747 1748 m0.m_flags = 0; 1749 m0.m_next = m; 1750 m0.m_data = m0.m_dat; 1751 m0.m_len = SLIP_HDRLEN; 1752 1753 hp = mtod(&m0, u_char *); 1754 1755 hp[SLX_DIR] = SLIPDIR_OUT; 1756 (void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); 1757 1758 _bpf_mtap(bp, &m0); 1759 m_freem(m); 1760 } 1761 1762 static struct mbuf * 1763 bpf_mbuf_enqueue(struct bpf_if *bp, struct mbuf *m) 1764 { 1765 struct mbuf *dup; 1766 1767 dup = m_dup(m, 0, M_COPYALL, M_NOWAIT); 1768 if (dup == NULL) 1769 return NULL; 1770 1771 if (bp->bif_mbuf_tail != NULL) { 1772 bp->bif_mbuf_tail->m_nextpkt = dup; 1773 } else { 1774 bp->bif_mbuf_head = dup; 1775 } 1776 bp->bif_mbuf_tail = dup; 1777 #ifdef BPF_MTAP_SOFTINT_DEBUG 1778 log(LOG_DEBUG, "%s: enqueued mbuf=%p to %s\n", 1779 __func__, dup, bp->bif_ifp->if_xname); 1780 #endif 1781 1782 return dup; 1783 } 1784 1785 static struct mbuf * 1786 bpf_mbuf_dequeue(struct bpf_if *bp) 1787 { 1788 struct mbuf *m; 1789 int s; 1790 1791 /* XXX NOMPSAFE: assumed running on one CPU */ 1792 s = splnet(); 1793 m = bp->bif_mbuf_head; 1794 if (m != NULL) { 1795 bp->bif_mbuf_head = m->m_nextpkt; 1796 m->m_nextpkt = NULL; 1797 1798 if (bp->bif_mbuf_head == NULL) 1799 bp->bif_mbuf_tail = NULL; 1800 #ifdef BPF_MTAP_SOFTINT_DEBUG 1801 log(LOG_DEBUG, "%s: dequeued mbuf=%p from %s\n", 1802 __func__, m, bp->bif_ifp->if_xname); 1803 #endif 1804 } 1805 splx(s); 1806 1807 return m; 1808 } 1809 1810 static void 1811 bpf_mtap_si(void *arg) 1812 { 1813 struct bpf_if *bp = arg; 1814 struct mbuf *m; 1815 1816 while ((m = bpf_mbuf_dequeue(bp)) != NULL) { 1817 #ifdef BPF_MTAP_SOFTINT_DEBUG 1818 log(LOG_DEBUG, "%s: tapping mbuf=%p on %s\n", 1819 __func__, m, bp->bif_ifp->if_xname); 1820 #endif 1821 bpf_ops->bpf_mtap(bp, m); 1822 m_freem(m); 1823 } 1824 } 1825 1826 static void 1827 _bpf_mtap_softint(struct ifnet *ifp, struct mbuf *m) 1828 { 1829 struct bpf_if *bp = ifp->if_bpf; 1830 struct mbuf *dup; 1831 1832 KASSERT(cpu_intr_p()); 1833 1834 /* To avoid extra invocations of the softint */ 1835 if (BPFIF_DLIST_READER_EMPTY(bp)) 1836 return; 1837 KASSERT(bp->bif_si != NULL); 1838 1839 dup = bpf_mbuf_enqueue(bp, m); 1840 if (dup != NULL) 1841 softint_schedule(bp->bif_si); 1842 } 1843 1844 static int 1845 bpf_hdrlen(struct bpf_d *d) 1846 { 1847 int hdrlen = d->bd_bif->bif_hdrlen; 1848 /* 1849 * Compute the length of the bpf header. This is not necessarily 1850 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1851 * that the network layer header begins on a longword boundary (for 1852 * performance reasons and to alleviate alignment restrictions). 1853 */ 1854 #ifdef _LP64 1855 if (d->bd_compat32) 1856 return (BPF_WORDALIGN32(hdrlen + SIZEOF_BPF_HDR32) - hdrlen); 1857 else 1858 #endif 1859 return (BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen); 1860 } 1861 1862 /* 1863 * Move the packet data from interface memory (pkt) into the 1864 * store buffer. Call the wakeup functions if it's time to wakeup 1865 * a listener (buffer full), "cpfn" is the routine called to do the 1866 * actual data transfer. memcpy is passed in to copy contiguous chunks, 1867 * while bpf_mcpy is passed in to copy mbuf chains. In the latter case, 1868 * pkt is really an mbuf. 1869 */ 1870 static void 1871 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1872 void *(*cpfn)(void *, const void *, size_t), struct timespec *ts) 1873 { 1874 char *h; 1875 int totlen, curlen, caplen; 1876 int hdrlen = bpf_hdrlen(d); 1877 int do_wakeup = 0; 1878 1879 atomic_inc_ulong(&d->bd_ccount); 1880 BPF_STATINC(capt); 1881 /* 1882 * Figure out how many bytes to move. If the packet is 1883 * greater or equal to the snapshot length, transfer that 1884 * much. Otherwise, transfer the whole packet (unless 1885 * we hit the buffer size limit). 1886 */ 1887 totlen = hdrlen + min(snaplen, pktlen); 1888 if (totlen > d->bd_bufsize) 1889 totlen = d->bd_bufsize; 1890 /* 1891 * If we adjusted totlen to fit the bufsize, it could be that 1892 * totlen is smaller than hdrlen because of the link layer header. 1893 */ 1894 caplen = totlen - hdrlen; 1895 if (caplen < 0) 1896 caplen = 0; 1897 1898 mutex_enter(d->bd_buf_mtx); 1899 /* 1900 * Round up the end of the previous packet to the next longword. 1901 */ 1902 #ifdef _LP64 1903 if (d->bd_compat32) 1904 curlen = BPF_WORDALIGN32(d->bd_slen); 1905 else 1906 #endif 1907 curlen = BPF_WORDALIGN(d->bd_slen); 1908 if (curlen + totlen > d->bd_bufsize) { 1909 /* 1910 * This packet will overflow the storage buffer. 1911 * Rotate the buffers if we can, then wakeup any 1912 * pending reads. 1913 */ 1914 if (d->bd_fbuf == NULL) { 1915 mutex_exit(d->bd_buf_mtx); 1916 /* 1917 * We haven't completed the previous read yet, 1918 * so drop the packet. 1919 */ 1920 atomic_inc_ulong(&d->bd_dcount); 1921 BPF_STATINC(drop); 1922 return; 1923 } 1924 ROTATE_BUFFERS(d); 1925 do_wakeup = 1; 1926 curlen = 0; 1927 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { 1928 /* 1929 * Immediate mode is set, or the read timeout has 1930 * already expired during a select call. A packet 1931 * arrived, so the reader should be woken up. 1932 */ 1933 do_wakeup = 1; 1934 } 1935 1936 /* 1937 * Append the bpf header. 1938 */ 1939 h = (char *)d->bd_sbuf + curlen; 1940 #ifdef _LP64 1941 if (d->bd_compat32) { 1942 struct bpf_hdr32 *hp32; 1943 1944 hp32 = (struct bpf_hdr32 *)h; 1945 hp32->bh_tstamp.tv_sec = ts->tv_sec; 1946 hp32->bh_tstamp.tv_usec = ts->tv_nsec / 1000; 1947 hp32->bh_datalen = pktlen; 1948 hp32->bh_hdrlen = hdrlen; 1949 hp32->bh_caplen = caplen; 1950 } else 1951 #endif 1952 { 1953 struct bpf_hdr *hp; 1954 1955 hp = (struct bpf_hdr *)h; 1956 hp->bh_tstamp.tv_sec = ts->tv_sec; 1957 hp->bh_tstamp.tv_usec = ts->tv_nsec / 1000; 1958 hp->bh_datalen = pktlen; 1959 hp->bh_hdrlen = hdrlen; 1960 hp->bh_caplen = caplen; 1961 } 1962 1963 /* 1964 * Copy the packet data into the store buffer and update its length. 1965 */ 1966 (*cpfn)(h + hdrlen, pkt, caplen); 1967 d->bd_slen = curlen + totlen; 1968 mutex_exit(d->bd_buf_mtx); 1969 1970 /* 1971 * Call bpf_wakeup after bd_slen has been updated so that kevent(2) 1972 * will cause filt_bpfread() to be called with it adjusted. 1973 */ 1974 if (do_wakeup) 1975 bpf_wakeup(d); 1976 } 1977 1978 /* 1979 * Initialize all nonzero fields of a descriptor. 1980 */ 1981 static int 1982 bpf_allocbufs(struct bpf_d *d) 1983 { 1984 1985 d->bd_fbuf = kmem_alloc(d->bd_bufsize, KM_NOSLEEP); 1986 if (!d->bd_fbuf) 1987 return (ENOBUFS); 1988 d->bd_sbuf = kmem_alloc(d->bd_bufsize, KM_NOSLEEP); 1989 if (!d->bd_sbuf) { 1990 kmem_free(d->bd_fbuf, d->bd_bufsize); 1991 return (ENOBUFS); 1992 } 1993 d->bd_slen = 0; 1994 d->bd_hlen = 0; 1995 return (0); 1996 } 1997 1998 static void 1999 bpf_free_filter(struct bpf_filter *filter) 2000 { 2001 2002 KASSERT(filter != NULL); 2003 KASSERT(filter->bf_insn != NULL); 2004 2005 kmem_free(filter->bf_insn, filter->bf_size); 2006 if (filter->bf_jitcode != NULL) 2007 bpf_jit_freecode(filter->bf_jitcode); 2008 kmem_free(filter, sizeof(*filter)); 2009 } 2010 2011 /* 2012 * Free buffers currently in use by a descriptor. 2013 * Called on close. 2014 */ 2015 static void 2016 bpf_freed(struct bpf_d *d) 2017 { 2018 /* 2019 * We don't need to lock out interrupts since this descriptor has 2020 * been detached from its interface and it yet hasn't been marked 2021 * free. 2022 */ 2023 if (d->bd_sbuf != NULL) { 2024 kmem_free(d->bd_sbuf, d->bd_bufsize); 2025 if (d->bd_hbuf != NULL) 2026 kmem_free(d->bd_hbuf, d->bd_bufsize); 2027 if (d->bd_fbuf != NULL) 2028 kmem_free(d->bd_fbuf, d->bd_bufsize); 2029 } 2030 if (d->bd_filter != NULL) { 2031 bpf_free_filter(d->bd_filter); 2032 d->bd_filter = NULL; 2033 } 2034 d->bd_jitcode = NULL; 2035 } 2036 2037 /* 2038 * Attach an interface to bpf. dlt is the link layer type; 2039 * hdrlen is the fixed size of the link header for the specified dlt 2040 * (variable length headers not yet supported). 2041 */ 2042 static void 2043 _bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2044 { 2045 struct bpf_if *bp; 2046 bp = kmem_alloc(sizeof(*bp), KM_NOSLEEP); 2047 if (bp == NULL) 2048 panic("bpfattach"); 2049 2050 mutex_enter(&bpf_mtx); 2051 bp->bif_driverp = driverp; 2052 bp->bif_ifp = ifp; 2053 bp->bif_dlt = dlt; 2054 bp->bif_si = NULL; 2055 BPF_IFLIST_ENTRY_INIT(bp); 2056 PSLIST_INIT(&bp->bif_dlist_head); 2057 psref_target_init(&bp->bif_psref, bpf_psref_class); 2058 2059 BPF_IFLIST_WRITER_INSERT_HEAD(bp); 2060 2061 *bp->bif_driverp = NULL; 2062 2063 bp->bif_hdrlen = hdrlen; 2064 mutex_exit(&bpf_mtx); 2065 #if 0 2066 printf("bpf: %s attached\n", ifp->if_xname); 2067 #endif 2068 } 2069 2070 static void 2071 _bpf_mtap_softint_init(struct ifnet *ifp) 2072 { 2073 struct bpf_if *bp; 2074 2075 mutex_enter(&bpf_mtx); 2076 BPF_IFLIST_WRITER_FOREACH(bp) { 2077 if (bp->bif_ifp != ifp) 2078 continue; 2079 2080 bp->bif_mbuf_head = NULL; 2081 bp->bif_mbuf_tail = NULL; 2082 bp->bif_si = softint_establish(SOFTINT_NET, bpf_mtap_si, bp); 2083 if (bp->bif_si == NULL) 2084 panic("%s: softint_establish() failed", __func__); 2085 break; 2086 } 2087 mutex_exit(&bpf_mtx); 2088 2089 if (bp == NULL) 2090 panic("%s: no bpf_if found for %s", __func__, ifp->if_xname); 2091 } 2092 2093 /* 2094 * Remove an interface from bpf. 2095 */ 2096 static void 2097 _bpfdetach(struct ifnet *ifp) 2098 { 2099 struct bpf_if *bp; 2100 struct bpf_d *d; 2101 int s; 2102 2103 mutex_enter(&bpf_mtx); 2104 /* Nuke the vnodes for any open instances */ 2105 again_d: 2106 BPF_DLIST_WRITER_FOREACH(d) { 2107 mutex_enter(d->bd_mtx); 2108 if (d->bd_bif != NULL && d->bd_bif->bif_ifp == ifp) { 2109 /* 2110 * Detach the descriptor from an interface now. 2111 * It will be free'ed later by close routine. 2112 */ 2113 d->bd_promisc = 0; /* we can't touch device. */ 2114 bpf_detachd(d); 2115 mutex_exit(d->bd_mtx); 2116 goto again_d; 2117 } 2118 mutex_exit(d->bd_mtx); 2119 } 2120 2121 again: 2122 BPF_IFLIST_WRITER_FOREACH(bp) { 2123 if (bp->bif_ifp == ifp) { 2124 BPF_IFLIST_WRITER_REMOVE(bp); 2125 2126 pserialize_perform(bpf_psz); 2127 psref_target_destroy(&bp->bif_psref, bpf_psref_class); 2128 2129 BPF_IFLIST_ENTRY_DESTROY(bp); 2130 if (bp->bif_si != NULL) { 2131 /* XXX NOMPSAFE: assumed running on one CPU */ 2132 s = splnet(); 2133 while (bp->bif_mbuf_head != NULL) { 2134 struct mbuf *m = bp->bif_mbuf_head; 2135 bp->bif_mbuf_head = m->m_nextpkt; 2136 m_freem(m); 2137 } 2138 splx(s); 2139 softint_disestablish(bp->bif_si); 2140 } 2141 kmem_free(bp, sizeof(*bp)); 2142 goto again; 2143 } 2144 } 2145 mutex_exit(&bpf_mtx); 2146 } 2147 2148 /* 2149 * Change the data link type of a interface. 2150 */ 2151 static void 2152 _bpf_change_type(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2153 { 2154 struct bpf_if *bp; 2155 2156 mutex_enter(&bpf_mtx); 2157 BPF_IFLIST_WRITER_FOREACH(bp) { 2158 if (bp->bif_driverp == &ifp->if_bpf) 2159 break; 2160 } 2161 if (bp == NULL) 2162 panic("bpf_change_type"); 2163 2164 bp->bif_dlt = dlt; 2165 2166 bp->bif_hdrlen = hdrlen; 2167 mutex_exit(&bpf_mtx); 2168 } 2169 2170 /* 2171 * Get a list of available data link type of the interface. 2172 */ 2173 static int 2174 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2175 { 2176 int n, error; 2177 struct ifnet *ifp; 2178 struct bpf_if *bp; 2179 int s, bound; 2180 2181 KASSERT(mutex_owned(d->bd_mtx)); 2182 2183 ifp = d->bd_bif->bif_ifp; 2184 n = 0; 2185 error = 0; 2186 2187 bound = curlwp_bind(); 2188 s = pserialize_read_enter(); 2189 BPF_IFLIST_READER_FOREACH(bp) { 2190 if (bp->bif_ifp != ifp) 2191 continue; 2192 if (bfl->bfl_list != NULL) { 2193 struct psref psref; 2194 2195 if (n >= bfl->bfl_len) { 2196 pserialize_read_exit(s); 2197 return ENOMEM; 2198 } 2199 2200 bpf_if_acquire(bp, &psref); 2201 pserialize_read_exit(s); 2202 2203 error = copyout(&bp->bif_dlt, 2204 bfl->bfl_list + n, sizeof(u_int)); 2205 2206 s = pserialize_read_enter(); 2207 bpf_if_release(bp, &psref); 2208 } 2209 n++; 2210 } 2211 pserialize_read_exit(s); 2212 curlwp_bindx(bound); 2213 2214 bfl->bfl_len = n; 2215 return error; 2216 } 2217 2218 /* 2219 * Set the data link type of a BPF instance. 2220 */ 2221 static int 2222 bpf_setdlt(struct bpf_d *d, u_int dlt) 2223 { 2224 int error, opromisc; 2225 struct ifnet *ifp; 2226 struct bpf_if *bp; 2227 2228 KASSERT(mutex_owned(&bpf_mtx)); 2229 KASSERT(mutex_owned(d->bd_mtx)); 2230 2231 if (d->bd_bif->bif_dlt == dlt) 2232 return 0; 2233 ifp = d->bd_bif->bif_ifp; 2234 BPF_IFLIST_WRITER_FOREACH(bp) { 2235 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2236 break; 2237 } 2238 if (bp == NULL) 2239 return EINVAL; 2240 opromisc = d->bd_promisc; 2241 bpf_detachd(d); 2242 bpf_attachd(d, bp); 2243 reset_d(d); 2244 if (opromisc) { 2245 #ifndef NET_MPSAFE 2246 KERNEL_LOCK(1, NULL); 2247 #endif 2248 error = ifpromisc(bp->bif_ifp, 1); 2249 #ifndef NET_MPSAFE 2250 KERNEL_UNLOCK_ONE(NULL); 2251 #endif 2252 if (error) 2253 printf("%s: bpf_setdlt: ifpromisc failed (%d)\n", 2254 bp->bif_ifp->if_xname, error); 2255 else 2256 d->bd_promisc = 1; 2257 } 2258 return 0; 2259 } 2260 2261 static int 2262 sysctl_net_bpf_maxbufsize(SYSCTLFN_ARGS) 2263 { 2264 int newsize, error; 2265 struct sysctlnode node; 2266 2267 node = *rnode; 2268 node.sysctl_data = &newsize; 2269 newsize = bpf_maxbufsize; 2270 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 2271 if (error || newp == NULL) 2272 return (error); 2273 2274 if (newsize < BPF_MINBUFSIZE || newsize > BPF_MAXBUFSIZE) 2275 return (EINVAL); 2276 2277 bpf_maxbufsize = newsize; 2278 2279 return (0); 2280 } 2281 2282 #if defined(MODULAR) || defined(BPFJIT) 2283 static int 2284 sysctl_net_bpf_jit(SYSCTLFN_ARGS) 2285 { 2286 bool newval; 2287 int error; 2288 struct sysctlnode node; 2289 2290 node = *rnode; 2291 node.sysctl_data = &newval; 2292 newval = bpf_jit; 2293 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 2294 if (error != 0 || newp == NULL) 2295 return error; 2296 2297 bpf_jit = newval; 2298 2299 /* 2300 * Do a full sync to publish new bpf_jit value and 2301 * update bpfjit_module_ops.bj_generate_code variable. 2302 */ 2303 membar_sync(); 2304 2305 if (newval && bpfjit_module_ops.bj_generate_code == NULL) { 2306 printf("JIT compilation is postponed " 2307 "until after bpfjit module is loaded\n"); 2308 } 2309 2310 return 0; 2311 } 2312 #endif 2313 2314 static int 2315 sysctl_net_bpf_peers(SYSCTLFN_ARGS) 2316 { 2317 int error, elem_count; 2318 struct bpf_d *dp; 2319 struct bpf_d_ext dpe; 2320 size_t len, needed, elem_size, out_size; 2321 char *sp; 2322 2323 if (namelen == 1 && name[0] == CTL_QUERY) 2324 return (sysctl_query(SYSCTLFN_CALL(rnode))); 2325 2326 if (namelen != 2) 2327 return (EINVAL); 2328 2329 /* BPF peers is privileged information. */ 2330 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE, 2331 KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, NULL, NULL, NULL); 2332 if (error) 2333 return (EPERM); 2334 2335 len = (oldp != NULL) ? *oldlenp : 0; 2336 sp = oldp; 2337 elem_size = name[0]; 2338 elem_count = name[1]; 2339 out_size = MIN(sizeof(dpe), elem_size); 2340 needed = 0; 2341 2342 if (elem_size < 1 || elem_count < 0) 2343 return (EINVAL); 2344 2345 mutex_enter(&bpf_mtx); 2346 BPF_DLIST_WRITER_FOREACH(dp) { 2347 if (len >= elem_size && elem_count > 0) { 2348 #define BPF_EXT(field) dpe.bde_ ## field = dp->bd_ ## field 2349 BPF_EXT(bufsize); 2350 BPF_EXT(promisc); 2351 BPF_EXT(state); 2352 BPF_EXT(immediate); 2353 BPF_EXT(hdrcmplt); 2354 BPF_EXT(seesent); 2355 BPF_EXT(pid); 2356 BPF_EXT(rcount); 2357 BPF_EXT(dcount); 2358 BPF_EXT(ccount); 2359 #undef BPF_EXT 2360 mutex_enter(dp->bd_mtx); 2361 if (dp->bd_bif) 2362 (void)strlcpy(dpe.bde_ifname, 2363 dp->bd_bif->bif_ifp->if_xname, 2364 IFNAMSIZ - 1); 2365 else 2366 dpe.bde_ifname[0] = '\0'; 2367 mutex_exit(dp->bd_mtx); 2368 2369 error = copyout(&dpe, sp, out_size); 2370 if (error) 2371 break; 2372 sp += elem_size; 2373 len -= elem_size; 2374 } 2375 needed += elem_size; 2376 if (elem_count > 0 && elem_count != INT_MAX) 2377 elem_count--; 2378 } 2379 mutex_exit(&bpf_mtx); 2380 2381 *oldlenp = needed; 2382 2383 return (error); 2384 } 2385 2386 static void 2387 bpf_stats(void *p, void *arg, struct cpu_info *ci __unused) 2388 { 2389 struct bpf_stat *const stats = p; 2390 struct bpf_stat *sum = arg; 2391 2392 sum->bs_recv += stats->bs_recv; 2393 sum->bs_drop += stats->bs_drop; 2394 sum->bs_capt += stats->bs_capt; 2395 } 2396 2397 static int 2398 bpf_sysctl_gstats_handler(SYSCTLFN_ARGS) 2399 { 2400 struct sysctlnode node; 2401 int error; 2402 struct bpf_stat sum; 2403 2404 memset(&sum, 0, sizeof(sum)); 2405 node = *rnode; 2406 2407 percpu_foreach(bpf_gstats_percpu, bpf_stats, &sum); 2408 2409 node.sysctl_data = ∑ 2410 node.sysctl_size = sizeof(sum); 2411 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 2412 if (error != 0 || newp == NULL) 2413 return error; 2414 2415 return 0; 2416 } 2417 2418 static struct sysctllog *bpf_sysctllog; 2419 static void 2420 sysctl_net_bpf_setup(void) 2421 { 2422 const struct sysctlnode *node; 2423 2424 node = NULL; 2425 sysctl_createv(&bpf_sysctllog, 0, NULL, &node, 2426 CTLFLAG_PERMANENT, 2427 CTLTYPE_NODE, "bpf", 2428 SYSCTL_DESCR("BPF options"), 2429 NULL, 0, NULL, 0, 2430 CTL_NET, CTL_CREATE, CTL_EOL); 2431 if (node != NULL) { 2432 #if defined(MODULAR) || defined(BPFJIT) 2433 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2434 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2435 CTLTYPE_BOOL, "jit", 2436 SYSCTL_DESCR("Toggle Just-In-Time compilation"), 2437 sysctl_net_bpf_jit, 0, &bpf_jit, 0, 2438 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2439 #endif 2440 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2441 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2442 CTLTYPE_INT, "maxbufsize", 2443 SYSCTL_DESCR("Maximum size for data capture buffer"), 2444 sysctl_net_bpf_maxbufsize, 0, &bpf_maxbufsize, 0, 2445 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2446 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2447 CTLFLAG_PERMANENT, 2448 CTLTYPE_STRUCT, "stats", 2449 SYSCTL_DESCR("BPF stats"), 2450 bpf_sysctl_gstats_handler, 0, NULL, 0, 2451 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2452 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2453 CTLFLAG_PERMANENT, 2454 CTLTYPE_STRUCT, "peers", 2455 SYSCTL_DESCR("BPF peers"), 2456 sysctl_net_bpf_peers, 0, NULL, 0, 2457 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2458 } 2459 2460 } 2461 2462 struct bpf_ops bpf_ops_kernel = { 2463 .bpf_attach = _bpfattach, 2464 .bpf_detach = _bpfdetach, 2465 .bpf_change_type = _bpf_change_type, 2466 2467 .bpf_tap = _bpf_tap, 2468 .bpf_mtap = _bpf_mtap, 2469 .bpf_mtap2 = _bpf_mtap2, 2470 .bpf_mtap_af = _bpf_mtap_af, 2471 .bpf_mtap_sl_in = _bpf_mtap_sl_in, 2472 .bpf_mtap_sl_out = _bpf_mtap_sl_out, 2473 2474 .bpf_mtap_softint = _bpf_mtap_softint, 2475 .bpf_mtap_softint_init = _bpf_mtap_softint_init, 2476 }; 2477 2478 MODULE(MODULE_CLASS_DRIVER, bpf, "bpf_filter"); 2479 2480 static int 2481 bpf_modcmd(modcmd_t cmd, void *arg) 2482 { 2483 #ifdef _MODULE 2484 devmajor_t bmajor, cmajor; 2485 #endif 2486 int error = 0; 2487 2488 switch (cmd) { 2489 case MODULE_CMD_INIT: 2490 bpf_init(); 2491 #ifdef _MODULE 2492 bmajor = cmajor = NODEVMAJOR; 2493 error = devsw_attach("bpf", NULL, &bmajor, 2494 &bpf_cdevsw, &cmajor); 2495 if (error) 2496 break; 2497 #endif 2498 2499 bpf_ops_handover_enter(&bpf_ops_kernel); 2500 atomic_swap_ptr(&bpf_ops, &bpf_ops_kernel); 2501 bpf_ops_handover_exit(); 2502 sysctl_net_bpf_setup(); 2503 break; 2504 2505 case MODULE_CMD_FINI: 2506 /* 2507 * While there is no reference counting for bpf callers, 2508 * unload could at least in theory be done similarly to 2509 * system call disestablishment. This should even be 2510 * a little simpler: 2511 * 2512 * 1) replace op vector with stubs 2513 * 2) post update to all cpus with xc 2514 * 3) check that nobody is in bpf anymore 2515 * (it's doubtful we'd want something like l_sysent, 2516 * but we could do something like *signed* percpu 2517 * counters. if the sum is 0, we're good). 2518 * 4) if fail, unroll changes 2519 * 2520 * NOTE: change won't be atomic to the outside. some 2521 * packets may be not captured even if unload is 2522 * not succesful. I think packet capture not working 2523 * is a perfectly logical consequence of trying to 2524 * disable packet capture. 2525 */ 2526 error = EOPNOTSUPP; 2527 /* insert sysctl teardown */ 2528 break; 2529 2530 default: 2531 error = ENOTTY; 2532 break; 2533 } 2534 2535 return error; 2536 } 2537
Indexes created Mon Sep 22 13:09:51 GMT 2025