bpf.c revision 1.230
1 /* $NetBSD: bpf.c,v 1.230 2019/09/12 07:38:19 maxv 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 1.230 2019/09/12 07:38:19 maxv 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 u_int); 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 *); 271 272 static const struct fileops bpf_fileops = { 273 .fo_name = "bpf", 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 | D_MPSAFE 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 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 488 error = ifpromisc(bp->bif_ifp, 0); 489 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 490 #ifdef DIAGNOSTIC 491 if (error) 492 printf("%s: ifpromisc failed: %d", __func__, error); 493 #endif 494 } 495 496 /* Remove d from the interface's descriptor list. */ 497 BPFIF_DLIST_WRITER_REMOVE(d); 498 499 pserialize_perform(bpf_psz); 500 501 if (BPFIF_DLIST_WRITER_EMPTY(bp)) { 502 /* 503 * Let the driver know that there are no more listeners. 504 */ 505 *d->bd_bif->bif_driverp = NULL; 506 } 507 d->bd_bif = NULL; 508 } 509 510 static void 511 bpf_init(void) 512 { 513 514 mutex_init(&bpf_mtx, MUTEX_DEFAULT, IPL_NONE); 515 bpf_psz = pserialize_create(); 516 bpf_psref_class = psref_class_create("bpf", IPL_SOFTNET); 517 518 PSLIST_INIT(&bpf_iflist); 519 PSLIST_INIT(&bpf_dlist); 520 521 bpf_gstats_percpu = percpu_alloc(sizeof(struct bpf_stat)); 522 523 return; 524 } 525 526 /* 527 * bpfilterattach() is called at boot time. We don't need to do anything 528 * here, since any initialization will happen as part of module init code. 529 */ 530 /* ARGSUSED */ 531 void 532 bpfilterattach(int n) 533 { 534 535 } 536 537 /* 538 * Open ethernet device. Clones. 539 */ 540 /* ARGSUSED */ 541 int 542 bpfopen(dev_t dev, int flag, int mode, struct lwp *l) 543 { 544 struct bpf_d *d; 545 struct file *fp; 546 int error, fd; 547 548 /* falloc() will fill in the descriptor for us. */ 549 if ((error = fd_allocfile(&fp, &fd)) != 0) 550 return error; 551 552 d = kmem_zalloc(sizeof(*d), KM_SLEEP); 553 d->bd_bufsize = bpf_bufsize; 554 d->bd_direction = BPF_D_INOUT; 555 d->bd_feedback = 0; 556 d->bd_pid = l->l_proc->p_pid; 557 #ifdef _LP64 558 if (curproc->p_flag & PK_32) 559 d->bd_compat32 = 1; 560 #endif 561 getnanotime(&d->bd_btime); 562 d->bd_atime = d->bd_mtime = d->bd_btime; 563 callout_init(&d->bd_callout, CALLOUT_MPSAFE); 564 selinit(&d->bd_sel); 565 d->bd_jitcode = NULL; 566 d->bd_filter = NULL; 567 BPF_DLIST_ENTRY_INIT(d); 568 BPFIF_DLIST_ENTRY_INIT(d); 569 d->bd_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTNET); 570 d->bd_buf_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NET); 571 cv_init(&d->bd_cv, "bpf"); 572 573 mutex_enter(&bpf_mtx); 574 BPF_DLIST_WRITER_INSERT_HEAD(d); 575 mutex_exit(&bpf_mtx); 576 577 return fd_clone(fp, fd, flag, &bpf_fileops, d); 578 } 579 580 /* 581 * Close the descriptor by detaching it from its interface, 582 * deallocating its buffers, and marking it free. 583 */ 584 /* ARGSUSED */ 585 static int 586 bpf_close(struct file *fp) 587 { 588 struct bpf_d *d; 589 590 mutex_enter(&bpf_mtx); 591 592 if ((d = fp->f_bpf) == NULL) { 593 mutex_exit(&bpf_mtx); 594 return 0; 595 } 596 597 /* 598 * Refresh the PID associated with this bpf file. 599 */ 600 d->bd_pid = curproc->p_pid; 601 602 mutex_enter(d->bd_mtx); 603 if (d->bd_state == BPF_WAITING) 604 callout_halt(&d->bd_callout, d->bd_mtx); 605 d->bd_state = BPF_IDLE; 606 if (d->bd_bif) 607 bpf_detachd(d); 608 mutex_exit(d->bd_mtx); 609 610 BPF_DLIST_WRITER_REMOVE(d); 611 612 pserialize_perform(bpf_psz); 613 mutex_exit(&bpf_mtx); 614 615 BPFIF_DLIST_ENTRY_DESTROY(d); 616 BPF_DLIST_ENTRY_DESTROY(d); 617 fp->f_bpf = NULL; 618 bpf_freed(d); 619 callout_destroy(&d->bd_callout); 620 seldestroy(&d->bd_sel); 621 mutex_obj_free(d->bd_mtx); 622 mutex_obj_free(d->bd_buf_mtx); 623 cv_destroy(&d->bd_cv); 624 625 kmem_free(d, sizeof(*d)); 626 627 return (0); 628 } 629 630 /* 631 * Rotate the packet buffers in descriptor d. Move the store buffer 632 * into the hold slot, and the free buffer into the store slot. 633 * Zero the length of the new store buffer. 634 */ 635 #define ROTATE_BUFFERS(d) \ 636 (d)->bd_hbuf = (d)->bd_sbuf; \ 637 (d)->bd_hlen = (d)->bd_slen; \ 638 (d)->bd_sbuf = (d)->bd_fbuf; \ 639 (d)->bd_slen = 0; \ 640 (d)->bd_fbuf = NULL; 641 /* 642 * bpfread - read next chunk of packets from buffers 643 */ 644 static int 645 bpf_read(struct file *fp, off_t *offp, struct uio *uio, 646 kauth_cred_t cred, int flags) 647 { 648 struct bpf_d *d = fp->f_bpf; 649 int timed_out; 650 int error; 651 652 getnanotime(&d->bd_atime); 653 /* 654 * Restrict application to use a buffer the same size as 655 * the kernel buffers. 656 */ 657 if (uio->uio_resid != d->bd_bufsize) 658 return (EINVAL); 659 660 mutex_enter(d->bd_mtx); 661 if (d->bd_state == BPF_WAITING) 662 callout_halt(&d->bd_callout, d->bd_mtx); 663 timed_out = (d->bd_state == BPF_TIMED_OUT); 664 d->bd_state = BPF_IDLE; 665 mutex_exit(d->bd_mtx); 666 /* 667 * If the hold buffer is empty, then do a timed sleep, which 668 * ends when the timeout expires or when enough packets 669 * have arrived to fill the store buffer. 670 */ 671 mutex_enter(d->bd_buf_mtx); 672 while (d->bd_hbuf == NULL) { 673 if (fp->f_flag & FNONBLOCK) { 674 if (d->bd_slen == 0) { 675 error = EWOULDBLOCK; 676 goto out; 677 } 678 ROTATE_BUFFERS(d); 679 break; 680 } 681 682 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 683 /* 684 * A packet(s) either arrived since the previous 685 * read or arrived while we were asleep. 686 * Rotate the buffers and return what's here. 687 */ 688 ROTATE_BUFFERS(d); 689 break; 690 } 691 692 error = cv_timedwait_sig(&d->bd_cv, d->bd_buf_mtx, d->bd_rtout); 693 694 if (error == EINTR || error == ERESTART) 695 goto out; 696 697 if (error == EWOULDBLOCK) { 698 /* 699 * On a timeout, return what's in the buffer, 700 * which may be nothing. If there is something 701 * in the store buffer, we can rotate the buffers. 702 */ 703 if (d->bd_hbuf) 704 /* 705 * We filled up the buffer in between 706 * getting the timeout and arriving 707 * here, so we don't need to rotate. 708 */ 709 break; 710 711 if (d->bd_slen == 0) { 712 error = 0; 713 goto out; 714 } 715 ROTATE_BUFFERS(d); 716 break; 717 } 718 if (error != 0) 719 goto out; 720 } 721 /* 722 * At this point, we know we have something in the hold slot. 723 */ 724 mutex_exit(d->bd_buf_mtx); 725 726 /* 727 * Move data from hold buffer into user space. 728 * We know the entire buffer is transferred since 729 * we checked above that the read buffer is bpf_bufsize bytes. 730 */ 731 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 732 733 mutex_enter(d->bd_buf_mtx); 734 d->bd_fbuf = d->bd_hbuf; 735 d->bd_hbuf = NULL; 736 d->bd_hlen = 0; 737 out: 738 mutex_exit(d->bd_buf_mtx); 739 return (error); 740 } 741 742 743 /* 744 * If there are processes sleeping on this descriptor, wake them up. 745 */ 746 static inline void 747 bpf_wakeup(struct bpf_d *d) 748 { 749 750 mutex_enter(d->bd_buf_mtx); 751 cv_broadcast(&d->bd_cv); 752 mutex_exit(d->bd_buf_mtx); 753 754 if (d->bd_async) 755 fownsignal(d->bd_pgid, SIGIO, 0, 0, NULL); 756 selnotify(&d->bd_sel, 0, 0); 757 } 758 759 static void 760 bpf_timed_out(void *arg) 761 { 762 struct bpf_d *d = arg; 763 764 mutex_enter(d->bd_mtx); 765 if (d->bd_state == BPF_WAITING) { 766 d->bd_state = BPF_TIMED_OUT; 767 if (d->bd_slen != 0) 768 bpf_wakeup(d); 769 } 770 mutex_exit(d->bd_mtx); 771 } 772 773 774 static int 775 bpf_write(struct file *fp, off_t *offp, struct uio *uio, 776 kauth_cred_t cred, int flags) 777 { 778 struct bpf_d *d = fp->f_bpf; 779 struct bpf_if *bp; 780 struct ifnet *ifp; 781 struct mbuf *m, *mc; 782 int error; 783 static struct sockaddr_storage dst; 784 struct psref psref; 785 int bound; 786 787 m = NULL; /* XXX gcc */ 788 789 bound = curlwp_bind(); 790 mutex_enter(d->bd_mtx); 791 bp = d->bd_bif; 792 if (bp == NULL) { 793 mutex_exit(d->bd_mtx); 794 error = ENXIO; 795 goto out_bindx; 796 } 797 bpf_if_acquire(bp, &psref); 798 mutex_exit(d->bd_mtx); 799 800 getnanotime(&d->bd_mtime); 801 802 ifp = bp->bif_ifp; 803 if (if_is_deactivated(ifp)) { 804 error = ENXIO; 805 goto out; 806 } 807 808 if (uio->uio_resid == 0) { 809 error = 0; 810 goto out; 811 } 812 813 error = bpf_movein(uio, (int)bp->bif_dlt, ifp->if_mtu, &m, 814 (struct sockaddr *) &dst); 815 if (error) 816 goto out; 817 818 if (m->m_pkthdr.len > ifp->if_mtu) { 819 m_freem(m); 820 error = EMSGSIZE; 821 goto out; 822 } 823 824 if (d->bd_hdrcmplt) 825 dst.ss_family = pseudo_AF_HDRCMPLT; 826 827 if (d->bd_feedback) { 828 mc = m_dup(m, 0, M_COPYALL, M_NOWAIT); 829 if (mc != NULL) 830 m_set_rcvif(mc, ifp); 831 /* Set M_PROMISC for outgoing packets to be discarded. */ 832 if (1 /*d->bd_direction == BPF_D_INOUT*/) 833 m->m_flags |= M_PROMISC; 834 } else 835 mc = NULL; 836 837 error = if_output_lock(ifp, ifp, m, (struct sockaddr *) &dst, NULL); 838 839 if (mc != NULL) { 840 if (error == 0) { 841 int s = splsoftnet(); 842 KERNEL_LOCK_UNLESS_IFP_MPSAFE(ifp); 843 ifp->_if_input(ifp, mc); 844 KERNEL_UNLOCK_UNLESS_IFP_MPSAFE(ifp); 845 splx(s); 846 } else 847 m_freem(mc); 848 } 849 /* 850 * The driver frees the mbuf. 851 */ 852 out: 853 bpf_if_release(bp, &psref); 854 out_bindx: 855 curlwp_bindx(bound); 856 return error; 857 } 858 859 /* 860 * Reset a descriptor by flushing its packet buffer and clearing the 861 * receive and drop counts. 862 */ 863 static void 864 reset_d(struct bpf_d *d) 865 { 866 867 KASSERT(mutex_owned(d->bd_mtx)); 868 869 mutex_enter(d->bd_buf_mtx); 870 if (d->bd_hbuf) { 871 /* Free the hold buffer. */ 872 d->bd_fbuf = d->bd_hbuf; 873 d->bd_hbuf = NULL; 874 } 875 d->bd_slen = 0; 876 d->bd_hlen = 0; 877 d->bd_rcount = 0; 878 d->bd_dcount = 0; 879 d->bd_ccount = 0; 880 mutex_exit(d->bd_buf_mtx); 881 } 882 883 /* 884 * FIONREAD Check for read packet available. 885 * BIOCGBLEN Get buffer len [for read()]. 886 * BIOCSETF Set ethernet read filter. 887 * BIOCFLUSH Flush read packet buffer. 888 * BIOCPROMISC Put interface into promiscuous mode. 889 * BIOCGDLT Get link layer type. 890 * BIOCGETIF Get interface name. 891 * BIOCSETIF Set interface. 892 * BIOCSRTIMEOUT Set read timeout. 893 * BIOCGRTIMEOUT Get read timeout. 894 * BIOCGSTATS Get packet stats. 895 * BIOCIMMEDIATE Set immediate mode. 896 * BIOCVERSION Get filter language version. 897 * BIOCGHDRCMPLT Get "header already complete" flag. 898 * BIOCSHDRCMPLT Set "header already complete" flag. 899 * BIOCSFEEDBACK Set packet feedback mode. 900 * BIOCGFEEDBACK Get packet feedback mode. 901 * BIOCGDIRECTION Get packet direction flag 902 * BIOCSDIRECTION Set packet direction flag 903 */ 904 /* ARGSUSED */ 905 static int 906 bpf_ioctl(struct file *fp, u_long cmd, void *addr) 907 { 908 struct bpf_d *d = fp->f_bpf; 909 int error = 0; 910 911 /* 912 * Refresh the PID associated with this bpf file. 913 */ 914 d->bd_pid = curproc->p_pid; 915 #ifdef _LP64 916 if (curproc->p_flag & PK_32) 917 d->bd_compat32 = 1; 918 else 919 d->bd_compat32 = 0; 920 #endif 921 922 mutex_enter(d->bd_mtx); 923 if (d->bd_state == BPF_WAITING) 924 callout_halt(&d->bd_callout, d->bd_mtx); 925 d->bd_state = BPF_IDLE; 926 mutex_exit(d->bd_mtx); 927 928 switch (cmd) { 929 930 default: 931 error = EINVAL; 932 break; 933 934 /* 935 * Check for read packet available. 936 */ 937 case FIONREAD: 938 { 939 int n; 940 941 mutex_enter(d->bd_buf_mtx); 942 n = d->bd_slen; 943 if (d->bd_hbuf) 944 n += d->bd_hlen; 945 mutex_exit(d->bd_buf_mtx); 946 947 *(int *)addr = n; 948 break; 949 } 950 951 /* 952 * Get buffer len [for read()]. 953 */ 954 case BIOCGBLEN: 955 *(u_int *)addr = d->bd_bufsize; 956 break; 957 958 /* 959 * Set buffer length. 960 */ 961 case BIOCSBLEN: 962 /* 963 * Forbid to change the buffer length if buffers are already 964 * allocated. 965 */ 966 mutex_enter(d->bd_mtx); 967 mutex_enter(d->bd_buf_mtx); 968 if (d->bd_bif != NULL || d->bd_sbuf != NULL) 969 error = EINVAL; 970 else { 971 u_int size = *(u_int *)addr; 972 973 if (size > bpf_maxbufsize) 974 *(u_int *)addr = size = bpf_maxbufsize; 975 else if (size < BPF_MINBUFSIZE) 976 *(u_int *)addr = size = BPF_MINBUFSIZE; 977 d->bd_bufsize = size; 978 } 979 mutex_exit(d->bd_buf_mtx); 980 mutex_exit(d->bd_mtx); 981 break; 982 983 /* 984 * Set link layer read filter. 985 */ 986 case BIOCSETF: 987 error = bpf_setf(d, addr); 988 break; 989 990 /* 991 * Flush read packet buffer. 992 */ 993 case BIOCFLUSH: 994 mutex_enter(d->bd_mtx); 995 reset_d(d); 996 mutex_exit(d->bd_mtx); 997 break; 998 999 /* 1000 * Put interface into promiscuous mode. 1001 */ 1002 case BIOCPROMISC: 1003 mutex_enter(d->bd_mtx); 1004 if (d->bd_bif == NULL) { 1005 mutex_exit(d->bd_mtx); 1006 /* 1007 * No interface attached yet. 1008 */ 1009 error = EINVAL; 1010 break; 1011 } 1012 if (d->bd_promisc == 0) { 1013 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1014 error = ifpromisc(d->bd_bif->bif_ifp, 1); 1015 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1016 if (error == 0) 1017 d->bd_promisc = 1; 1018 } 1019 mutex_exit(d->bd_mtx); 1020 break; 1021 1022 /* 1023 * Get device parameters. 1024 */ 1025 case BIOCGDLT: 1026 mutex_enter(d->bd_mtx); 1027 if (d->bd_bif == NULL) 1028 error = EINVAL; 1029 else 1030 *(u_int *)addr = d->bd_bif->bif_dlt; 1031 mutex_exit(d->bd_mtx); 1032 break; 1033 1034 /* 1035 * Get a list of supported device parameters. 1036 */ 1037 case BIOCGDLTLIST: 1038 mutex_enter(d->bd_mtx); 1039 if (d->bd_bif == NULL) 1040 error = EINVAL; 1041 else 1042 error = bpf_getdltlist(d, addr); 1043 mutex_exit(d->bd_mtx); 1044 break; 1045 1046 /* 1047 * Set device parameters. 1048 */ 1049 case BIOCSDLT: 1050 mutex_enter(&bpf_mtx); 1051 mutex_enter(d->bd_mtx); 1052 if (d->bd_bif == NULL) 1053 error = EINVAL; 1054 else 1055 error = bpf_setdlt(d, *(u_int *)addr); 1056 mutex_exit(d->bd_mtx); 1057 mutex_exit(&bpf_mtx); 1058 break; 1059 1060 /* 1061 * Set interface name. 1062 */ 1063 #ifdef OBIOCGETIF 1064 case OBIOCGETIF: 1065 #endif 1066 case BIOCGETIF: 1067 mutex_enter(d->bd_mtx); 1068 if (d->bd_bif == NULL) 1069 error = EINVAL; 1070 else 1071 bpf_ifname(d->bd_bif->bif_ifp, addr); 1072 mutex_exit(d->bd_mtx); 1073 break; 1074 1075 /* 1076 * Set interface. 1077 */ 1078 #ifdef OBIOCSETIF 1079 case OBIOCSETIF: 1080 #endif 1081 case BIOCSETIF: 1082 mutex_enter(&bpf_mtx); 1083 error = bpf_setif(d, addr); 1084 mutex_exit(&bpf_mtx); 1085 break; 1086 1087 /* 1088 * Set read timeout. 1089 */ 1090 case BIOCSRTIMEOUT: 1091 { 1092 struct timeval *tv = addr; 1093 1094 /* Compute number of ticks. */ 1095 d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick; 1096 if ((d->bd_rtout == 0) && (tv->tv_usec != 0)) 1097 d->bd_rtout = 1; 1098 break; 1099 } 1100 1101 #ifdef BIOCGORTIMEOUT 1102 /* 1103 * Get read timeout. 1104 */ 1105 case BIOCGORTIMEOUT: 1106 { 1107 struct timeval50 *tv = addr; 1108 1109 tv->tv_sec = d->bd_rtout / hz; 1110 tv->tv_usec = (d->bd_rtout % hz) * tick; 1111 break; 1112 } 1113 #endif 1114 1115 #ifdef BIOCSORTIMEOUT 1116 /* 1117 * Set read timeout. 1118 */ 1119 case BIOCSORTIMEOUT: 1120 { 1121 struct timeval50 *tv = addr; 1122 1123 /* Compute number of ticks. */ 1124 d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick; 1125 if ((d->bd_rtout == 0) && (tv->tv_usec != 0)) 1126 d->bd_rtout = 1; 1127 break; 1128 } 1129 #endif 1130 1131 /* 1132 * Get read timeout. 1133 */ 1134 case BIOCGRTIMEOUT: 1135 { 1136 struct timeval *tv = addr; 1137 1138 tv->tv_sec = d->bd_rtout / hz; 1139 tv->tv_usec = (d->bd_rtout % hz) * tick; 1140 break; 1141 } 1142 /* 1143 * Get packet stats. 1144 */ 1145 case BIOCGSTATS: 1146 { 1147 struct bpf_stat *bs = addr; 1148 1149 bs->bs_recv = d->bd_rcount; 1150 bs->bs_drop = d->bd_dcount; 1151 bs->bs_capt = d->bd_ccount; 1152 break; 1153 } 1154 1155 case BIOCGSTATSOLD: 1156 { 1157 struct bpf_stat_old *bs = addr; 1158 1159 bs->bs_recv = d->bd_rcount; 1160 bs->bs_drop = d->bd_dcount; 1161 break; 1162 } 1163 1164 /* 1165 * Set immediate mode. 1166 */ 1167 case BIOCIMMEDIATE: 1168 d->bd_immediate = *(u_int *)addr; 1169 break; 1170 1171 case BIOCVERSION: 1172 { 1173 struct bpf_version *bv = addr; 1174 1175 bv->bv_major = BPF_MAJOR_VERSION; 1176 bv->bv_minor = BPF_MINOR_VERSION; 1177 break; 1178 } 1179 1180 case BIOCGHDRCMPLT: /* get "header already complete" flag */ 1181 *(u_int *)addr = d->bd_hdrcmplt; 1182 break; 1183 1184 case BIOCSHDRCMPLT: /* set "header already complete" flag */ 1185 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 1186 break; 1187 1188 /* 1189 * Get packet direction flag 1190 */ 1191 case BIOCGDIRECTION: 1192 *(u_int *)addr = d->bd_direction; 1193 break; 1194 1195 /* 1196 * Set packet direction flag 1197 */ 1198 case BIOCSDIRECTION: 1199 { 1200 u_int direction; 1201 1202 direction = *(u_int *)addr; 1203 switch (direction) { 1204 case BPF_D_IN: 1205 case BPF_D_INOUT: 1206 case BPF_D_OUT: 1207 d->bd_direction = direction; 1208 break; 1209 default: 1210 error = EINVAL; 1211 } 1212 } 1213 break; 1214 1215 /* 1216 * Set "feed packets from bpf back to input" mode 1217 */ 1218 case BIOCSFEEDBACK: 1219 d->bd_feedback = *(u_int *)addr; 1220 break; 1221 1222 /* 1223 * Get "feed packets from bpf back to input" mode 1224 */ 1225 case BIOCGFEEDBACK: 1226 *(u_int *)addr = d->bd_feedback; 1227 break; 1228 1229 case FIONBIO: /* Non-blocking I/O */ 1230 /* 1231 * No need to do anything special as we use IO_NDELAY in 1232 * bpfread() as an indication of whether or not to block 1233 * the read. 1234 */ 1235 break; 1236 1237 case FIOASYNC: /* Send signal on receive packets */ 1238 mutex_enter(d->bd_mtx); 1239 d->bd_async = *(int *)addr; 1240 mutex_exit(d->bd_mtx); 1241 break; 1242 1243 case TIOCSPGRP: /* Process or group to send signals to */ 1244 case FIOSETOWN: 1245 error = fsetown(&d->bd_pgid, cmd, addr); 1246 break; 1247 1248 case TIOCGPGRP: 1249 case FIOGETOWN: 1250 error = fgetown(d->bd_pgid, cmd, addr); 1251 break; 1252 } 1253 return (error); 1254 } 1255 1256 /* 1257 * Set d's packet filter program to fp. If this file already has a filter, 1258 * free it and replace it. Returns EINVAL for bogus requests. 1259 */ 1260 static int 1261 bpf_setf(struct bpf_d *d, struct bpf_program *fp) 1262 { 1263 struct bpf_insn *fcode; 1264 bpfjit_func_t jcode; 1265 size_t flen, size = 0; 1266 struct bpf_filter *oldf, *newf; 1267 1268 jcode = NULL; 1269 flen = fp->bf_len; 1270 1271 if ((fp->bf_insns == NULL && flen) || flen > BPF_MAXINSNS) { 1272 return EINVAL; 1273 } 1274 1275 if (flen) { 1276 /* 1277 * Allocate the buffer, copy the byte-code from 1278 * userspace and validate it. 1279 */ 1280 size = flen * sizeof(*fp->bf_insns); 1281 fcode = kmem_alloc(size, KM_SLEEP); 1282 if (copyin(fp->bf_insns, fcode, size) != 0 || 1283 !bpf_validate(fcode, (int)flen)) { 1284 kmem_free(fcode, size); 1285 return EINVAL; 1286 } 1287 membar_consumer(); 1288 if (bpf_jit) 1289 jcode = bpf_jit_generate(NULL, fcode, flen); 1290 } else { 1291 fcode = NULL; 1292 } 1293 1294 newf = kmem_alloc(sizeof(*newf), KM_SLEEP); 1295 newf->bf_insn = fcode; 1296 newf->bf_size = size; 1297 newf->bf_jitcode = jcode; 1298 d->bd_jitcode = jcode; /* XXX just for kvm(3) users */ 1299 1300 /* Need to hold bpf_mtx for pserialize_perform */ 1301 mutex_enter(&bpf_mtx); 1302 mutex_enter(d->bd_mtx); 1303 oldf = d->bd_filter; 1304 d->bd_filter = newf; 1305 membar_producer(); 1306 reset_d(d); 1307 pserialize_perform(bpf_psz); 1308 mutex_exit(d->bd_mtx); 1309 mutex_exit(&bpf_mtx); 1310 1311 if (oldf != NULL) 1312 bpf_free_filter(oldf); 1313 1314 return 0; 1315 } 1316 1317 /* 1318 * Detach a file from its current interface (if attached at all) and attach 1319 * to the interface indicated by the name stored in ifr. 1320 * Return an errno or 0. 1321 */ 1322 static int 1323 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1324 { 1325 struct bpf_if *bp; 1326 char *cp; 1327 int unit_seen, i, error; 1328 1329 KASSERT(mutex_owned(&bpf_mtx)); 1330 /* 1331 * Make sure the provided name has a unit number, and default 1332 * it to '0' if not specified. 1333 * XXX This is ugly ... do this differently? 1334 */ 1335 unit_seen = 0; 1336 cp = ifr->ifr_name; 1337 cp[sizeof(ifr->ifr_name) - 1] = '\0'; /* sanity */ 1338 while (*cp++) 1339 if (*cp >= '0' && *cp <= '9') 1340 unit_seen = 1; 1341 if (!unit_seen) { 1342 /* Make sure to leave room for the '\0'. */ 1343 for (i = 0; i < (IFNAMSIZ - 1); ++i) { 1344 if ((ifr->ifr_name[i] >= 'a' && 1345 ifr->ifr_name[i] <= 'z') || 1346 (ifr->ifr_name[i] >= 'A' && 1347 ifr->ifr_name[i] <= 'Z')) 1348 continue; 1349 ifr->ifr_name[i] = '0'; 1350 } 1351 } 1352 1353 /* 1354 * Look through attached interfaces for the named one. 1355 */ 1356 BPF_IFLIST_WRITER_FOREACH(bp) { 1357 struct ifnet *ifp = bp->bif_ifp; 1358 1359 if (ifp == NULL || 1360 strcmp(ifp->if_xname, ifr->ifr_name) != 0) 1361 continue; 1362 /* skip additional entry */ 1363 if (bp->bif_driverp != &ifp->if_bpf) 1364 continue; 1365 /* 1366 * We found the requested interface. 1367 * Allocate the packet buffers if we need to. 1368 * If we're already attached to requested interface, 1369 * just flush the buffer. 1370 */ 1371 /* 1372 * bpf_allocbufs is called only here. bpf_mtx ensures that 1373 * no race condition happen on d->bd_sbuf. 1374 */ 1375 if (d->bd_sbuf == NULL) { 1376 error = bpf_allocbufs(d); 1377 if (error != 0) 1378 return (error); 1379 } 1380 mutex_enter(d->bd_mtx); 1381 if (bp != d->bd_bif) { 1382 if (d->bd_bif) { 1383 /* 1384 * Detach if attached to something else. 1385 */ 1386 bpf_detachd(d); 1387 BPFIF_DLIST_ENTRY_INIT(d); 1388 } 1389 1390 bpf_attachd(d, bp); 1391 } 1392 reset_d(d); 1393 mutex_exit(d->bd_mtx); 1394 return (0); 1395 } 1396 /* Not found. */ 1397 return (ENXIO); 1398 } 1399 1400 /* 1401 * Copy the interface name to the ifreq. 1402 */ 1403 static void 1404 bpf_ifname(struct ifnet *ifp, struct ifreq *ifr) 1405 { 1406 memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ); 1407 } 1408 1409 static int 1410 bpf_stat(struct file *fp, struct stat *st) 1411 { 1412 struct bpf_d *d = fp->f_bpf; 1413 1414 (void)memset(st, 0, sizeof(*st)); 1415 mutex_enter(d->bd_mtx); 1416 st->st_dev = makedev(cdevsw_lookup_major(&bpf_cdevsw), d->bd_pid); 1417 st->st_atimespec = d->bd_atime; 1418 st->st_mtimespec = d->bd_mtime; 1419 st->st_ctimespec = st->st_birthtimespec = d->bd_btime; 1420 st->st_uid = kauth_cred_geteuid(fp->f_cred); 1421 st->st_gid = kauth_cred_getegid(fp->f_cred); 1422 st->st_mode = S_IFCHR; 1423 mutex_exit(d->bd_mtx); 1424 return 0; 1425 } 1426 1427 /* 1428 * Support for poll() system call 1429 * 1430 * Return true iff the specific operation will not block indefinitely - with 1431 * the assumption that it is safe to positively acknowledge a request for the 1432 * ability to write to the BPF device. 1433 * Otherwise, return false but make a note that a selnotify() must be done. 1434 */ 1435 static int 1436 bpf_poll(struct file *fp, int events) 1437 { 1438 struct bpf_d *d = fp->f_bpf; 1439 int revents; 1440 1441 /* 1442 * Refresh the PID associated with this bpf file. 1443 */ 1444 mutex_enter(&bpf_mtx); 1445 d->bd_pid = curproc->p_pid; 1446 1447 revents = events & (POLLOUT | POLLWRNORM); 1448 if (events & (POLLIN | POLLRDNORM)) { 1449 /* 1450 * An imitation of the FIONREAD ioctl code. 1451 */ 1452 mutex_enter(d->bd_mtx); 1453 if (d->bd_hlen != 0 || 1454 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1455 d->bd_slen != 0)) { 1456 revents |= events & (POLLIN | POLLRDNORM); 1457 } else { 1458 selrecord(curlwp, &d->bd_sel); 1459 /* Start the read timeout if necessary */ 1460 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1461 callout_reset(&d->bd_callout, d->bd_rtout, 1462 bpf_timed_out, d); 1463 d->bd_state = BPF_WAITING; 1464 } 1465 } 1466 mutex_exit(d->bd_mtx); 1467 } 1468 1469 mutex_exit(&bpf_mtx); 1470 return (revents); 1471 } 1472 1473 static void 1474 filt_bpfrdetach(struct knote *kn) 1475 { 1476 struct bpf_d *d = kn->kn_hook; 1477 1478 mutex_enter(d->bd_buf_mtx); 1479 SLIST_REMOVE(&d->bd_sel.sel_klist, kn, knote, kn_selnext); 1480 mutex_exit(d->bd_buf_mtx); 1481 } 1482 1483 static int 1484 filt_bpfread(struct knote *kn, long hint) 1485 { 1486 struct bpf_d *d = kn->kn_hook; 1487 int rv; 1488 1489 mutex_enter(d->bd_buf_mtx); 1490 kn->kn_data = d->bd_hlen; 1491 if (d->bd_immediate) 1492 kn->kn_data += d->bd_slen; 1493 rv = (kn->kn_data > 0); 1494 mutex_exit(d->bd_buf_mtx); 1495 return rv; 1496 } 1497 1498 static const struct filterops bpfread_filtops = { 1499 .f_isfd = 1, 1500 .f_attach = NULL, 1501 .f_detach = filt_bpfrdetach, 1502 .f_event = filt_bpfread, 1503 }; 1504 1505 static int 1506 bpf_kqfilter(struct file *fp, struct knote *kn) 1507 { 1508 struct bpf_d *d = fp->f_bpf; 1509 struct klist *klist; 1510 1511 mutex_enter(d->bd_buf_mtx); 1512 switch (kn->kn_filter) { 1513 case EVFILT_READ: 1514 klist = &d->bd_sel.sel_klist; 1515 kn->kn_fop = &bpfread_filtops; 1516 break; 1517 1518 default: 1519 mutex_exit(d->bd_buf_mtx); 1520 return (EINVAL); 1521 } 1522 1523 kn->kn_hook = d; 1524 1525 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1526 mutex_exit(d->bd_buf_mtx); 1527 1528 return (0); 1529 } 1530 1531 /* 1532 * Copy data from an mbuf chain into a buffer. This code is derived 1533 * from m_copydata in sys/uipc_mbuf.c. 1534 */ 1535 static void * 1536 bpf_mcpy(void *dst_arg, const void *src_arg, size_t len) 1537 { 1538 const struct mbuf *m; 1539 u_int count; 1540 u_char *dst; 1541 1542 m = src_arg; 1543 dst = dst_arg; 1544 while (len > 0) { 1545 if (m == NULL) 1546 panic("bpf_mcpy"); 1547 count = uimin(m->m_len, len); 1548 memcpy(dst, mtod(m, const void *), count); 1549 m = m->m_next; 1550 dst += count; 1551 len -= count; 1552 } 1553 return dst_arg; 1554 } 1555 1556 /* 1557 * Dispatch a packet to all the listeners on interface bp. 1558 * 1559 * pkt pointer to the packet, either a data buffer or an mbuf chain 1560 * buflen buffer length, if pkt is a data buffer 1561 * cpfn a function that can copy pkt into the listener's buffer 1562 * pktlen length of the packet 1563 * direction BPF_D_IN or BPF_D_OUT 1564 */ 1565 static inline void 1566 bpf_deliver(struct bpf_if *bp, void *(*cpfn)(void *, const void *, size_t), 1567 void *pkt, u_int pktlen, u_int buflen, const u_int direction) 1568 { 1569 uint32_t mem[BPF_MEMWORDS]; 1570 bpf_args_t args = { 1571 .pkt = (const uint8_t *)pkt, 1572 .wirelen = pktlen, 1573 .buflen = buflen, 1574 .mem = mem, 1575 .arg = NULL 1576 }; 1577 bool gottime = false; 1578 struct timespec ts; 1579 struct bpf_d *d; 1580 int s; 1581 1582 KASSERT(!cpu_intr_p()); 1583 1584 /* 1585 * Note that the IPL does not have to be raised at this point. 1586 * The only problem that could arise here is that if two different 1587 * interfaces shared any data. This is not the case. 1588 */ 1589 s = pserialize_read_enter(); 1590 BPFIF_DLIST_READER_FOREACH(d, bp) { 1591 u_int slen = 0; 1592 struct bpf_filter *filter; 1593 1594 if (direction == BPF_D_IN) { 1595 if (d->bd_direction == BPF_D_OUT) 1596 continue; 1597 } else { /* BPF_D_OUT */ 1598 if (d->bd_direction == BPF_D_IN) 1599 continue; 1600 } 1601 1602 atomic_inc_ulong(&d->bd_rcount); 1603 BPF_STATINC(recv); 1604 1605 filter = d->bd_filter; 1606 membar_datadep_consumer(); 1607 if (filter != NULL) { 1608 if (filter->bf_jitcode != NULL) 1609 slen = filter->bf_jitcode(NULL, &args); 1610 else 1611 slen = bpf_filter_ext(NULL, filter->bf_insn, 1612 &args); 1613 } 1614 1615 if (!slen) { 1616 continue; 1617 } 1618 if (!gottime) { 1619 gottime = true; 1620 nanotime(&ts); 1621 } 1622 /* Assume catchpacket doesn't sleep */ 1623 catchpacket(d, pkt, pktlen, slen, cpfn, &ts); 1624 } 1625 pserialize_read_exit(s); 1626 } 1627 1628 /* 1629 * Incoming linkage from device drivers, when the head of the packet is in 1630 * a buffer, and the tail is in an mbuf chain. 1631 */ 1632 static void 1633 _bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m, 1634 u_int direction) 1635 { 1636 u_int pktlen; 1637 struct mbuf mb; 1638 1639 /* Skip outgoing duplicate packets. */ 1640 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) { 1641 m->m_flags &= ~M_PROMISC; 1642 return; 1643 } 1644 1645 pktlen = m_length(m) + dlen; 1646 1647 /* 1648 * Craft on-stack mbuf suitable for passing to bpf_filter. 1649 * Note that we cut corners here; we only setup what's 1650 * absolutely needed--this mbuf should never go anywhere else. 1651 */ 1652 (void)memset(&mb, 0, sizeof(mb)); 1653 mb.m_type = MT_DATA; 1654 mb.m_next = m; 1655 mb.m_data = data; 1656 mb.m_len = dlen; 1657 1658 bpf_deliver(bp, bpf_mcpy, &mb, pktlen, 0, direction); 1659 } 1660 1661 /* 1662 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1663 */ 1664 static void 1665 _bpf_mtap(struct bpf_if *bp, struct mbuf *m, u_int direction) 1666 { 1667 void *(*cpfn)(void *, const void *, size_t); 1668 u_int pktlen, buflen; 1669 void *marg; 1670 1671 /* Skip outgoing duplicate packets. */ 1672 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) { 1673 m->m_flags &= ~M_PROMISC; 1674 return; 1675 } 1676 1677 pktlen = m_length(m); 1678 1679 if (pktlen == m->m_len) { 1680 cpfn = (void *)memcpy; 1681 marg = mtod(m, void *); 1682 buflen = pktlen; 1683 KASSERT(buflen != 0); 1684 } else { 1685 cpfn = bpf_mcpy; 1686 marg = m; 1687 buflen = 0; 1688 } 1689 1690 bpf_deliver(bp, cpfn, marg, pktlen, buflen, direction); 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, u_int direction) 1702 { 1703 struct mbuf m0; 1704 1705 m0.m_type = MT_DATA; 1706 m0.m_flags = 0; 1707 m0.m_next = m; 1708 m0.m_nextpkt = NULL; 1709 m0.m_owner = NULL; 1710 m0.m_len = 4; 1711 m0.m_data = (char *)⁡ 1712 1713 _bpf_mtap(bp, &m0, direction); 1714 } 1715 1716 /* 1717 * Put the SLIP pseudo-"link header" in place. 1718 * Note this M_PREPEND() should never fail, 1719 * swince we know we always have enough space 1720 * in the input buffer. 1721 */ 1722 static void 1723 _bpf_mtap_sl_in(struct bpf_if *bp, u_char *chdr, struct mbuf **m) 1724 { 1725 u_char *hp; 1726 1727 M_PREPEND(*m, SLIP_HDRLEN, M_DONTWAIT); 1728 if (*m == NULL) 1729 return; 1730 1731 hp = mtod(*m, u_char *); 1732 hp[SLX_DIR] = SLIPDIR_IN; 1733 (void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); 1734 1735 _bpf_mtap(bp, *m, BPF_D_IN); 1736 1737 m_adj(*m, SLIP_HDRLEN); 1738 } 1739 1740 /* 1741 * Put the SLIP pseudo-"link header" in 1742 * place. The compressed header is now 1743 * at the beginning of the mbuf. 1744 */ 1745 static void 1746 _bpf_mtap_sl_out(struct bpf_if *bp, u_char *chdr, struct mbuf *m) 1747 { 1748 struct mbuf m0; 1749 u_char *hp; 1750 1751 m0.m_type = MT_DATA; 1752 m0.m_flags = 0; 1753 m0.m_next = m; 1754 m0.m_nextpkt = NULL; 1755 m0.m_owner = NULL; 1756 m0.m_data = m0.m_dat; 1757 m0.m_len = SLIP_HDRLEN; 1758 1759 hp = mtod(&m0, u_char *); 1760 1761 hp[SLX_DIR] = SLIPDIR_OUT; 1762 (void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); 1763 1764 _bpf_mtap(bp, &m0, BPF_D_OUT); 1765 m_freem(m); 1766 } 1767 1768 static struct mbuf * 1769 bpf_mbuf_enqueue(struct bpf_if *bp, struct mbuf *m) 1770 { 1771 struct mbuf *dup; 1772 1773 dup = m_dup(m, 0, M_COPYALL, M_NOWAIT); 1774 if (dup == NULL) 1775 return NULL; 1776 1777 if (bp->bif_mbuf_tail != NULL) { 1778 bp->bif_mbuf_tail->m_nextpkt = dup; 1779 } else { 1780 bp->bif_mbuf_head = dup; 1781 } 1782 bp->bif_mbuf_tail = dup; 1783 #ifdef BPF_MTAP_SOFTINT_DEBUG 1784 log(LOG_DEBUG, "%s: enqueued mbuf=%p to %s\n", 1785 __func__, dup, bp->bif_ifp->if_xname); 1786 #endif 1787 1788 return dup; 1789 } 1790 1791 static struct mbuf * 1792 bpf_mbuf_dequeue(struct bpf_if *bp) 1793 { 1794 struct mbuf *m; 1795 int s; 1796 1797 /* XXX NOMPSAFE: assumed running on one CPU */ 1798 s = splnet(); 1799 m = bp->bif_mbuf_head; 1800 if (m != NULL) { 1801 bp->bif_mbuf_head = m->m_nextpkt; 1802 m->m_nextpkt = NULL; 1803 1804 if (bp->bif_mbuf_head == NULL) 1805 bp->bif_mbuf_tail = NULL; 1806 #ifdef BPF_MTAP_SOFTINT_DEBUG 1807 log(LOG_DEBUG, "%s: dequeued mbuf=%p from %s\n", 1808 __func__, m, bp->bif_ifp->if_xname); 1809 #endif 1810 } 1811 splx(s); 1812 1813 return m; 1814 } 1815 1816 static void 1817 bpf_mtap_si(void *arg) 1818 { 1819 struct bpf_if *bp = arg; 1820 struct mbuf *m; 1821 1822 while ((m = bpf_mbuf_dequeue(bp)) != NULL) { 1823 #ifdef BPF_MTAP_SOFTINT_DEBUG 1824 log(LOG_DEBUG, "%s: tapping mbuf=%p on %s\n", 1825 __func__, m, bp->bif_ifp->if_xname); 1826 #endif 1827 bpf_ops->bpf_mtap(bp, m, BPF_D_IN); 1828 m_freem(m); 1829 } 1830 } 1831 1832 static void 1833 _bpf_mtap_softint(struct ifnet *ifp, struct mbuf *m) 1834 { 1835 struct bpf_if *bp = ifp->if_bpf; 1836 struct mbuf *dup; 1837 1838 KASSERT(cpu_intr_p()); 1839 1840 /* To avoid extra invocations of the softint */ 1841 if (BPFIF_DLIST_READER_EMPTY(bp)) 1842 return; 1843 KASSERT(bp->bif_si != NULL); 1844 1845 dup = bpf_mbuf_enqueue(bp, m); 1846 if (dup != NULL) 1847 softint_schedule(bp->bif_si); 1848 } 1849 1850 static int 1851 bpf_hdrlen(struct bpf_d *d) 1852 { 1853 int hdrlen = d->bd_bif->bif_hdrlen; 1854 /* 1855 * Compute the length of the bpf header. This is not necessarily 1856 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1857 * that the network layer header begins on a longword boundary (for 1858 * performance reasons and to alleviate alignment restrictions). 1859 */ 1860 #ifdef _LP64 1861 if (d->bd_compat32) 1862 return (BPF_WORDALIGN32(hdrlen + SIZEOF_BPF_HDR32) - hdrlen); 1863 else 1864 #endif 1865 return (BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen); 1866 } 1867 1868 /* 1869 * Move the packet data from interface memory (pkt) into the 1870 * store buffer. Call the wakeup functions if it's time to wakeup 1871 * a listener (buffer full), "cpfn" is the routine called to do the 1872 * actual data transfer. memcpy is passed in to copy contiguous chunks, 1873 * while bpf_mcpy is passed in to copy mbuf chains. In the latter case, 1874 * pkt is really an mbuf. 1875 */ 1876 static void 1877 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1878 void *(*cpfn)(void *, const void *, size_t), struct timespec *ts) 1879 { 1880 char *h; 1881 int totlen, curlen, caplen; 1882 int hdrlen = bpf_hdrlen(d); 1883 int do_wakeup = 0; 1884 1885 atomic_inc_ulong(&d->bd_ccount); 1886 BPF_STATINC(capt); 1887 /* 1888 * Figure out how many bytes to move. If the packet is 1889 * greater or equal to the snapshot length, transfer that 1890 * much. Otherwise, transfer the whole packet (unless 1891 * we hit the buffer size limit). 1892 */ 1893 totlen = hdrlen + uimin(snaplen, pktlen); 1894 if (totlen > d->bd_bufsize) 1895 totlen = d->bd_bufsize; 1896 /* 1897 * If we adjusted totlen to fit the bufsize, it could be that 1898 * totlen is smaller than hdrlen because of the link layer header. 1899 */ 1900 caplen = totlen - hdrlen; 1901 if (caplen < 0) 1902 caplen = 0; 1903 1904 mutex_enter(d->bd_buf_mtx); 1905 /* 1906 * Round up the end of the previous packet to the next longword. 1907 */ 1908 #ifdef _LP64 1909 if (d->bd_compat32) 1910 curlen = BPF_WORDALIGN32(d->bd_slen); 1911 else 1912 #endif 1913 curlen = BPF_WORDALIGN(d->bd_slen); 1914 if (curlen + totlen > d->bd_bufsize) { 1915 /* 1916 * This packet will overflow the storage buffer. 1917 * Rotate the buffers if we can, then wakeup any 1918 * pending reads. 1919 */ 1920 if (d->bd_fbuf == NULL) { 1921 mutex_exit(d->bd_buf_mtx); 1922 /* 1923 * We haven't completed the previous read yet, 1924 * so drop the packet. 1925 */ 1926 atomic_inc_ulong(&d->bd_dcount); 1927 BPF_STATINC(drop); 1928 return; 1929 } 1930 ROTATE_BUFFERS(d); 1931 do_wakeup = 1; 1932 curlen = 0; 1933 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { 1934 /* 1935 * Immediate mode is set, or the read timeout has 1936 * already expired during a select call. A packet 1937 * arrived, so the reader should be woken up. 1938 */ 1939 do_wakeup = 1; 1940 } 1941 1942 /* 1943 * Append the bpf header. 1944 */ 1945 h = (char *)d->bd_sbuf + curlen; 1946 #ifdef _LP64 1947 if (d->bd_compat32) { 1948 struct bpf_hdr32 *hp32; 1949 1950 hp32 = (struct bpf_hdr32 *)h; 1951 hp32->bh_tstamp.tv_sec = ts->tv_sec; 1952 hp32->bh_tstamp.tv_usec = ts->tv_nsec / 1000; 1953 hp32->bh_datalen = pktlen; 1954 hp32->bh_hdrlen = hdrlen; 1955 hp32->bh_caplen = caplen; 1956 } else 1957 #endif 1958 { 1959 struct bpf_hdr *hp; 1960 1961 hp = (struct bpf_hdr *)h; 1962 hp->bh_tstamp.tv_sec = ts->tv_sec; 1963 hp->bh_tstamp.tv_usec = ts->tv_nsec / 1000; 1964 hp->bh_datalen = pktlen; 1965 hp->bh_hdrlen = hdrlen; 1966 hp->bh_caplen = caplen; 1967 } 1968 1969 /* 1970 * Copy the packet data into the store buffer and update its length. 1971 */ 1972 (*cpfn)(h + hdrlen, pkt, caplen); 1973 d->bd_slen = curlen + totlen; 1974 mutex_exit(d->bd_buf_mtx); 1975 1976 /* 1977 * Call bpf_wakeup after bd_slen has been updated so that kevent(2) 1978 * will cause filt_bpfread() to be called with it adjusted. 1979 */ 1980 if (do_wakeup) 1981 bpf_wakeup(d); 1982 } 1983 1984 /* 1985 * Initialize all nonzero fields of a descriptor. 1986 */ 1987 static int 1988 bpf_allocbufs(struct bpf_d *d) 1989 { 1990 1991 d->bd_fbuf = kmem_zalloc(d->bd_bufsize, KM_NOSLEEP); 1992 if (!d->bd_fbuf) 1993 return (ENOBUFS); 1994 d->bd_sbuf = kmem_zalloc(d->bd_bufsize, KM_NOSLEEP); 1995 if (!d->bd_sbuf) { 1996 kmem_free(d->bd_fbuf, d->bd_bufsize); 1997 return (ENOBUFS); 1998 } 1999 d->bd_slen = 0; 2000 d->bd_hlen = 0; 2001 return (0); 2002 } 2003 2004 static void 2005 bpf_free_filter(struct bpf_filter *filter) 2006 { 2007 2008 KASSERT(filter != NULL); 2009 KASSERT(filter->bf_insn != NULL); 2010 2011 kmem_free(filter->bf_insn, filter->bf_size); 2012 if (filter->bf_jitcode != NULL) 2013 bpf_jit_freecode(filter->bf_jitcode); 2014 kmem_free(filter, sizeof(*filter)); 2015 } 2016 2017 /* 2018 * Free buffers currently in use by a descriptor. 2019 * Called on close. 2020 */ 2021 static void 2022 bpf_freed(struct bpf_d *d) 2023 { 2024 /* 2025 * We don't need to lock out interrupts since this descriptor has 2026 * been detached from its interface and it yet hasn't been marked 2027 * free. 2028 */ 2029 if (d->bd_sbuf != NULL) { 2030 kmem_free(d->bd_sbuf, d->bd_bufsize); 2031 if (d->bd_hbuf != NULL) 2032 kmem_free(d->bd_hbuf, d->bd_bufsize); 2033 if (d->bd_fbuf != NULL) 2034 kmem_free(d->bd_fbuf, d->bd_bufsize); 2035 } 2036 if (d->bd_filter != NULL) { 2037 bpf_free_filter(d->bd_filter); 2038 d->bd_filter = NULL; 2039 } 2040 d->bd_jitcode = NULL; 2041 } 2042 2043 /* 2044 * Attach an interface to bpf. dlt is the link layer type; 2045 * hdrlen is the fixed size of the link header for the specified dlt 2046 * (variable length headers not yet supported). 2047 */ 2048 static void 2049 _bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 2050 { 2051 struct bpf_if *bp; 2052 bp = kmem_alloc(sizeof(*bp), KM_NOSLEEP); 2053 if (bp == NULL) 2054 panic("bpfattach"); 2055 2056 mutex_enter(&bpf_mtx); 2057 bp->bif_driverp = driverp; 2058 bp->bif_ifp = ifp; 2059 bp->bif_dlt = dlt; 2060 bp->bif_si = NULL; 2061 BPF_IFLIST_ENTRY_INIT(bp); 2062 PSLIST_INIT(&bp->bif_dlist_head); 2063 psref_target_init(&bp->bif_psref, bpf_psref_class); 2064 2065 BPF_IFLIST_WRITER_INSERT_HEAD(bp); 2066 2067 *bp->bif_driverp = NULL; 2068 2069 bp->bif_hdrlen = hdrlen; 2070 mutex_exit(&bpf_mtx); 2071 #if 0 2072 printf("bpf: %s attached\n", ifp->if_xname); 2073 #endif 2074 } 2075 2076 static void 2077 _bpf_mtap_softint_init(struct ifnet *ifp) 2078 { 2079 struct bpf_if *bp; 2080 2081 mutex_enter(&bpf_mtx); 2082 BPF_IFLIST_WRITER_FOREACH(bp) { 2083 if (bp->bif_ifp != ifp) 2084 continue; 2085 2086 bp->bif_mbuf_head = NULL; 2087 bp->bif_mbuf_tail = NULL; 2088 bp->bif_si = softint_establish(SOFTINT_NET, bpf_mtap_si, bp); 2089 if (bp->bif_si == NULL) 2090 panic("%s: softint_establish() failed", __func__); 2091 break; 2092 } 2093 mutex_exit(&bpf_mtx); 2094 2095 if (bp == NULL) 2096 panic("%s: no bpf_if found for %s", __func__, ifp->if_xname); 2097 } 2098 2099 /* 2100 * Remove an interface from bpf. 2101 */ 2102 static void 2103 _bpfdetach(struct ifnet *ifp) 2104 { 2105 struct bpf_if *bp; 2106 struct bpf_d *d; 2107 int s; 2108 2109 mutex_enter(&bpf_mtx); 2110 /* Nuke the vnodes for any open instances */ 2111 again_d: 2112 BPF_DLIST_WRITER_FOREACH(d) { 2113 mutex_enter(d->bd_mtx); 2114 if (d->bd_bif != NULL && d->bd_bif->bif_ifp == ifp) { 2115 /* 2116 * Detach the descriptor from an interface now. 2117 * It will be free'ed later by close routine. 2118 */ 2119 d->bd_promisc = 0; /* we can't touch device. */ 2120 bpf_detachd(d); 2121 mutex_exit(d->bd_mtx); 2122 goto again_d; 2123 } 2124 mutex_exit(d->bd_mtx); 2125 } 2126 2127 again: 2128 BPF_IFLIST_WRITER_FOREACH(bp) { 2129 if (bp->bif_ifp == ifp) { 2130 BPF_IFLIST_WRITER_REMOVE(bp); 2131 2132 pserialize_perform(bpf_psz); 2133 psref_target_destroy(&bp->bif_psref, bpf_psref_class); 2134 2135 BPF_IFLIST_ENTRY_DESTROY(bp); 2136 if (bp->bif_si != NULL) { 2137 /* XXX NOMPSAFE: assumed running on one CPU */ 2138 s = splnet(); 2139 while (bp->bif_mbuf_head != NULL) { 2140 struct mbuf *m = bp->bif_mbuf_head; 2141 bp->bif_mbuf_head = m->m_nextpkt; 2142 m_freem(m); 2143 } 2144 splx(s); 2145 softint_disestablish(bp->bif_si); 2146 } 2147 kmem_free(bp, sizeof(*bp)); 2148 goto again; 2149 } 2150 } 2151 mutex_exit(&bpf_mtx); 2152 } 2153 2154 /* 2155 * Change the data link type of a interface. 2156 */ 2157 static void 2158 _bpf_change_type(struct ifnet *ifp, u_int dlt, u_int hdrlen) 2159 { 2160 struct bpf_if *bp; 2161 2162 mutex_enter(&bpf_mtx); 2163 BPF_IFLIST_WRITER_FOREACH(bp) { 2164 if (bp->bif_driverp == &ifp->if_bpf) 2165 break; 2166 } 2167 if (bp == NULL) 2168 panic("bpf_change_type"); 2169 2170 bp->bif_dlt = dlt; 2171 2172 bp->bif_hdrlen = hdrlen; 2173 mutex_exit(&bpf_mtx); 2174 } 2175 2176 /* 2177 * Get a list of available data link type of the interface. 2178 */ 2179 static int 2180 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2181 { 2182 int n, error; 2183 struct ifnet *ifp; 2184 struct bpf_if *bp; 2185 int s, bound; 2186 2187 KASSERT(mutex_owned(d->bd_mtx)); 2188 2189 ifp = d->bd_bif->bif_ifp; 2190 n = 0; 2191 error = 0; 2192 2193 bound = curlwp_bind(); 2194 s = pserialize_read_enter(); 2195 BPF_IFLIST_READER_FOREACH(bp) { 2196 if (bp->bif_ifp != ifp) 2197 continue; 2198 if (bfl->bfl_list != NULL) { 2199 struct psref psref; 2200 2201 if (n >= bfl->bfl_len) { 2202 pserialize_read_exit(s); 2203 return ENOMEM; 2204 } 2205 2206 bpf_if_acquire(bp, &psref); 2207 pserialize_read_exit(s); 2208 2209 error = copyout(&bp->bif_dlt, 2210 bfl->bfl_list + n, sizeof(u_int)); 2211 2212 s = pserialize_read_enter(); 2213 bpf_if_release(bp, &psref); 2214 } 2215 n++; 2216 } 2217 pserialize_read_exit(s); 2218 curlwp_bindx(bound); 2219 2220 bfl->bfl_len = n; 2221 return error; 2222 } 2223 2224 /* 2225 * Set the data link type of a BPF instance. 2226 */ 2227 static int 2228 bpf_setdlt(struct bpf_d *d, u_int dlt) 2229 { 2230 int error, opromisc; 2231 struct ifnet *ifp; 2232 struct bpf_if *bp; 2233 2234 KASSERT(mutex_owned(&bpf_mtx)); 2235 KASSERT(mutex_owned(d->bd_mtx)); 2236 2237 if (d->bd_bif->bif_dlt == dlt) 2238 return 0; 2239 ifp = d->bd_bif->bif_ifp; 2240 BPF_IFLIST_WRITER_FOREACH(bp) { 2241 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 2242 break; 2243 } 2244 if (bp == NULL) 2245 return EINVAL; 2246 opromisc = d->bd_promisc; 2247 bpf_detachd(d); 2248 BPFIF_DLIST_ENTRY_INIT(d); 2249 bpf_attachd(d, bp); 2250 reset_d(d); 2251 if (opromisc) { 2252 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 2253 error = ifpromisc(bp->bif_ifp, 1); 2254 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 2255 if (error) 2256 printf("%s: bpf_setdlt: ifpromisc failed (%d)\n", 2257 bp->bif_ifp->if_xname, error); 2258 else 2259 d->bd_promisc = 1; 2260 } 2261 return 0; 2262 } 2263 2264 static int 2265 sysctl_net_bpf_maxbufsize(SYSCTLFN_ARGS) 2266 { 2267 int newsize, error; 2268 struct sysctlnode node; 2269 2270 node = *rnode; 2271 node.sysctl_data = &newsize; 2272 newsize = bpf_maxbufsize; 2273 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 2274 if (error || newp == NULL) 2275 return (error); 2276 2277 if (newsize < BPF_MINBUFSIZE || newsize > BPF_MAXBUFSIZE) 2278 return (EINVAL); 2279 2280 bpf_maxbufsize = newsize; 2281 2282 return (0); 2283 } 2284 2285 #if defined(MODULAR) || defined(BPFJIT) 2286 static int 2287 sysctl_net_bpf_jit(SYSCTLFN_ARGS) 2288 { 2289 bool newval; 2290 int error; 2291 struct sysctlnode node; 2292 2293 node = *rnode; 2294 node.sysctl_data = &newval; 2295 newval = bpf_jit; 2296 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 2297 if (error != 0 || newp == NULL) 2298 return error; 2299 2300 bpf_jit = newval; 2301 2302 /* 2303 * Do a full sync to publish new bpf_jit value and 2304 * update bpfjit_module_ops.bj_generate_code variable. 2305 */ 2306 membar_sync(); 2307 2308 if (newval && bpfjit_module_ops.bj_generate_code == NULL) { 2309 printf("JIT compilation is postponed " 2310 "until after bpfjit module is loaded\n"); 2311 } 2312 2313 return 0; 2314 } 2315 #endif 2316 2317 static int 2318 sysctl_net_bpf_peers(SYSCTLFN_ARGS) 2319 { 2320 int error, elem_count; 2321 struct bpf_d *dp; 2322 struct bpf_d_ext dpe; 2323 size_t len, needed, elem_size, out_size; 2324 char *sp; 2325 2326 if (namelen == 1 && name[0] == CTL_QUERY) 2327 return (sysctl_query(SYSCTLFN_CALL(rnode))); 2328 2329 if (namelen != 2) 2330 return (EINVAL); 2331 2332 /* BPF peers is privileged information. */ 2333 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE, 2334 KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, NULL, NULL, NULL); 2335 if (error) 2336 return (EPERM); 2337 2338 len = (oldp != NULL) ? *oldlenp : 0; 2339 sp = oldp; 2340 elem_size = name[0]; 2341 elem_count = name[1]; 2342 out_size = MIN(sizeof(dpe), elem_size); 2343 needed = 0; 2344 2345 if (elem_size < 1 || elem_count < 0) 2346 return (EINVAL); 2347 2348 mutex_enter(&bpf_mtx); 2349 BPF_DLIST_WRITER_FOREACH(dp) { 2350 if (len >= elem_size && elem_count > 0) { 2351 #define BPF_EXT(field) dpe.bde_ ## field = dp->bd_ ## field 2352 BPF_EXT(bufsize); 2353 BPF_EXT(promisc); 2354 BPF_EXT(state); 2355 BPF_EXT(immediate); 2356 BPF_EXT(hdrcmplt); 2357 BPF_EXT(direction); 2358 BPF_EXT(pid); 2359 BPF_EXT(rcount); 2360 BPF_EXT(dcount); 2361 BPF_EXT(ccount); 2362 #undef BPF_EXT 2363 mutex_enter(dp->bd_mtx); 2364 if (dp->bd_bif) 2365 (void)strlcpy(dpe.bde_ifname, 2366 dp->bd_bif->bif_ifp->if_xname, 2367 IFNAMSIZ - 1); 2368 else 2369 dpe.bde_ifname[0] = '\0'; 2370 mutex_exit(dp->bd_mtx); 2371 2372 error = copyout(&dpe, sp, out_size); 2373 if (error) 2374 break; 2375 sp += elem_size; 2376 len -= elem_size; 2377 } 2378 needed += elem_size; 2379 if (elem_count > 0 && elem_count != INT_MAX) 2380 elem_count--; 2381 } 2382 mutex_exit(&bpf_mtx); 2383 2384 *oldlenp = needed; 2385 2386 return (error); 2387 } 2388 2389 static void 2390 bpf_stats(void *p, void *arg, struct cpu_info *ci __unused) 2391 { 2392 struct bpf_stat *const stats = p; 2393 struct bpf_stat *sum = arg; 2394 2395 sum->bs_recv += stats->bs_recv; 2396 sum->bs_drop += stats->bs_drop; 2397 sum->bs_capt += stats->bs_capt; 2398 } 2399 2400 static int 2401 bpf_sysctl_gstats_handler(SYSCTLFN_ARGS) 2402 { 2403 struct sysctlnode node; 2404 int error; 2405 struct bpf_stat sum; 2406 2407 memset(&sum, 0, sizeof(sum)); 2408 node = *rnode; 2409 2410 percpu_foreach(bpf_gstats_percpu, bpf_stats, &sum); 2411 2412 node.sysctl_data = ∑ 2413 node.sysctl_size = sizeof(sum); 2414 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 2415 if (error != 0 || newp == NULL) 2416 return error; 2417 2418 return 0; 2419 } 2420 2421 static struct sysctllog *bpf_sysctllog; 2422 static void 2423 sysctl_net_bpf_setup(void) 2424 { 2425 const struct sysctlnode *node; 2426 2427 node = NULL; 2428 sysctl_createv(&bpf_sysctllog, 0, NULL, &node, 2429 CTLFLAG_PERMANENT, 2430 CTLTYPE_NODE, "bpf", 2431 SYSCTL_DESCR("BPF options"), 2432 NULL, 0, NULL, 0, 2433 CTL_NET, CTL_CREATE, CTL_EOL); 2434 if (node != NULL) { 2435 #if defined(MODULAR) || defined(BPFJIT) 2436 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2437 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2438 CTLTYPE_BOOL, "jit", 2439 SYSCTL_DESCR("Toggle Just-In-Time compilation"), 2440 sysctl_net_bpf_jit, 0, &bpf_jit, 0, 2441 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2442 #endif 2443 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2444 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 2445 CTLTYPE_INT, "maxbufsize", 2446 SYSCTL_DESCR("Maximum size for data capture buffer"), 2447 sysctl_net_bpf_maxbufsize, 0, &bpf_maxbufsize, 0, 2448 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2449 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2450 CTLFLAG_PERMANENT, 2451 CTLTYPE_STRUCT, "stats", 2452 SYSCTL_DESCR("BPF stats"), 2453 bpf_sysctl_gstats_handler, 0, NULL, 0, 2454 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2455 sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, 2456 CTLFLAG_PERMANENT, 2457 CTLTYPE_STRUCT, "peers", 2458 SYSCTL_DESCR("BPF peers"), 2459 sysctl_net_bpf_peers, 0, NULL, 0, 2460 CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); 2461 } 2462 2463 } 2464 2465 struct bpf_ops bpf_ops_kernel = { 2466 .bpf_attach = _bpfattach, 2467 .bpf_detach = _bpfdetach, 2468 .bpf_change_type = _bpf_change_type, 2469 2470 .bpf_mtap = _bpf_mtap, 2471 .bpf_mtap2 = _bpf_mtap2, 2472 .bpf_mtap_af = _bpf_mtap_af, 2473 .bpf_mtap_sl_in = _bpf_mtap_sl_in, 2474 .bpf_mtap_sl_out = _bpf_mtap_sl_out, 2475 2476 .bpf_mtap_softint = _bpf_mtap_softint, 2477 .bpf_mtap_softint_init = _bpf_mtap_softint_init, 2478 }; 2479 2480 MODULE(MODULE_CLASS_DRIVER, bpf, "bpf_filter"); 2481 2482 static int 2483 bpf_modcmd(modcmd_t cmd, void *arg) 2484 { 2485 #ifdef _MODULE 2486 devmajor_t bmajor, cmajor; 2487 #endif 2488 int error = 0; 2489 2490 switch (cmd) { 2491 case MODULE_CMD_INIT: 2492 bpf_init(); 2493 #ifdef _MODULE 2494 bmajor = cmajor = NODEVMAJOR; 2495 error = devsw_attach("bpf", NULL, &bmajor, 2496 &bpf_cdevsw, &cmajor); 2497 if (error) 2498 break; 2499 #endif 2500 2501 bpf_ops_handover_enter(&bpf_ops_kernel); 2502 atomic_swap_ptr(&bpf_ops, &bpf_ops_kernel); 2503 bpf_ops_handover_exit(); 2504 sysctl_net_bpf_setup(); 2505 break; 2506 2507 case MODULE_CMD_FINI: 2508 /* 2509 * While there is no reference counting for bpf callers, 2510 * unload could at least in theory be done similarly to 2511 * system call disestablishment. This should even be 2512 * a little simpler: 2513 * 2514 * 1) replace op vector with stubs 2515 * 2) post update to all cpus with xc 2516 * 3) check that nobody is in bpf anymore 2517 * (it's doubtful we'd want something like l_sysent, 2518 * but we could do something like *signed* percpu 2519 * counters. if the sum is 0, we're good). 2520 * 4) if fail, unroll changes 2521 * 2522 * NOTE: change won't be atomic to the outside. some 2523 * packets may be not captured even if unload is 2524 * not succesful. I think packet capture not working 2525 * is a perfectly logical consequence of trying to 2526 * disable packet capture. 2527 */ 2528 error = EOPNOTSUPP; 2529 /* insert sysctl teardown */ 2530 break; 2531 2532 default: 2533 error = ENOTTY; 2534 break; 2535 } 2536 2537 return error; 2538 } 2539
Indexes created Mon Sep 22 13:09:51 GMT 2025