1 /* $NetBSD: if_shmem.c,v 1.39 2011/03/21 16:41:09 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2009, 2010 Antti Kantee. All Rights Reserved. 5 * 6 * Development of this software was supported by The Nokia Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 18 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.39 2011/03/21 16:41:09 pooka Exp $"); 32 33 #include <sys/param.h> 34 #include <sys/atomic.h> 35 #include <sys/fcntl.h> 36 #include <sys/kmem.h> 37 #include <sys/kthread.h> 38 #include <sys/lock.h> 39 #include <sys/vmem.h> 40 41 #include <net/bpf.h> 42 #include <net/if.h> 43 #include <net/if_dl.h> 44 #include <net/if_ether.h> 45 46 #include <netinet/in.h> 47 #include <netinet/in_var.h> 48 49 #include <rump/rump.h> 50 #include <rump/rumpuser.h> 51 52 #include "rump_private.h" 53 #include "rump_net_private.h" 54 55 static int shmif_clone(struct if_clone *, int); 56 static int shmif_unclone(struct ifnet *); 57 58 struct if_clone shmif_cloner = 59 IF_CLONE_INITIALIZER("shmif", shmif_clone, shmif_unclone); 60 61 /* 62 * Do r/w prefault for backend pages when attaching the interface. 63 * At least logically thinking improves performance (although no 64 * mlocking is done, so they might go away). 65 */ 66 #define PREFAULT_RW 67 68 /* 69 * A virtual ethernet interface which uses shared memory from a 70 * memory mapped file as the bus. 71 */ 72 73 static int shmif_init(struct ifnet *); 74 static int shmif_ioctl(struct ifnet *, u_long, void *); 75 static void shmif_start(struct ifnet *); 76 static void shmif_stop(struct ifnet *, int); 77 78 #include "shmifvar.h" 79 80 struct shmif_sc { 81 struct ethercom sc_ec; 82 struct shmif_mem *sc_busmem; 83 int sc_memfd; 84 int sc_kq; 85 int sc_unit; 86 87 char *sc_backfile; 88 size_t sc_backfilelen; 89 90 uint64_t sc_devgen; 91 uint32_t sc_nextpacket; 92 93 kmutex_t sc_mtx; 94 kcondvar_t sc_cv; 95 96 struct lwp *sc_rcvl; 97 bool sc_dying; 98 }; 99 100 static const uint32_t busversion = SHMIF_VERSION; 101 102 static void shmif_rcv(void *); 103 104 #define LOCK_UNLOCKED 0 105 #define LOCK_LOCKED 1 106 #define LOCK_COOLDOWN 1001 107 108 vmem_t *shmif_units; 109 110 /* 111 * This locking needs work and will misbehave severely if: 112 * 1) the backing memory has to be paged in 113 * 2) some lockholder exits while holding the lock 114 */ 115 static void 116 shmif_lockbus(struct shmif_mem *busmem) 117 { 118 int i = 0; 119 120 while (__predict_false(atomic_cas_32(&busmem->shm_lock, 121 LOCK_UNLOCKED, LOCK_LOCKED) == LOCK_LOCKED)) { 122 if (__predict_false(++i > LOCK_COOLDOWN)) { 123 uint64_t sec, nsec; 124 int error; 125 126 sec = 0; 127 nsec = 1000*1000; /* 1ms */ 128 rumpuser_nanosleep(&sec, &nsec, &error); 129 i = 0; 130 } 131 continue; 132 } 133 membar_enter(); 134 } 135 136 static void 137 shmif_unlockbus(struct shmif_mem *busmem) 138 { 139 unsigned int old; 140 141 membar_exit(); 142 old = atomic_swap_32(&busmem->shm_lock, LOCK_UNLOCKED); 143 KASSERT(old == LOCK_LOCKED); 144 } 145 146 static int 147 allocif(int unit, struct shmif_sc **scp) 148 { 149 uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0xa0, 0x00, 0x00, 0x00, 0x00 }; 150 struct shmif_sc *sc; 151 struct ifnet *ifp; 152 uint32_t randnum; 153 int error; 154 155 randnum = arc4random(); 156 memcpy(&enaddr[2], &randnum, sizeof(randnum)); 157 158 sc = kmem_zalloc(sizeof(*sc), KM_SLEEP); 159 sc->sc_memfd = -1; 160 sc->sc_unit = unit; 161 162 ifp = &sc->sc_ec.ec_if; 163 164 sprintf(ifp->if_xname, "shmif%d", unit); 165 ifp->if_softc = sc; 166 ifp->if_flags = IFF_BROADCAST | IFF_MULTICAST; 167 ifp->if_init = shmif_init; 168 ifp->if_ioctl = shmif_ioctl; 169 ifp->if_start = shmif_start; 170 ifp->if_stop = shmif_stop; 171 ifp->if_mtu = ETHERMTU; 172 ifp->if_dlt = DLT_EN10MB; 173 174 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE); 175 cv_init(&sc->sc_cv, "shmifcv"); 176 177 if_attach(ifp); 178 ether_ifattach(ifp, enaddr); 179 180 aprint_verbose("shmif%d: Ethernet address %s\n", 181 unit, ether_sprintf(enaddr)); 182 183 if (scp) 184 *scp = sc; 185 186 error = 0; 187 if (rump_threads) { 188 error = kthread_create(PRI_NONE, 189 KTHREAD_MPSAFE | KTHREAD_JOINABLE, NULL, 190 shmif_rcv, ifp, &sc->sc_rcvl, "shmif"); 191 } else { 192 printf("WARNING: threads not enabled, shmif NOT working\n"); 193 } 194 195 if (error) { 196 shmif_unclone(ifp); 197 } 198 199 return error; 200 } 201 202 static int 203 initbackend(struct shmif_sc *sc, int memfd) 204 { 205 volatile uint8_t v; 206 volatile uint8_t *p; 207 int error; 208 209 sc->sc_busmem = rumpuser_filemmap(memfd, 0, BUSMEM_SIZE, 210 RUMPUSER_FILEMMAP_TRUNCATE | RUMPUSER_FILEMMAP_SHARED 211 | RUMPUSER_FILEMMAP_READ | RUMPUSER_FILEMMAP_WRITE, &error); 212 if (error) 213 return error; 214 215 if (sc->sc_busmem->shm_magic 216 && sc->sc_busmem->shm_magic != SHMIF_MAGIC) { 217 printf("bus is not magical"); 218 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 219 return ENOEXEC; 220 } 221 222 /* 223 * Prefault in pages to minimize runtime penalty with buslock. 224 * Use 512 instead of PAGE_SIZE to make sure we catch cases where 225 * rump kernel PAGE_SIZE > host page size. 226 */ 227 for (p = (uint8_t *)sc->sc_busmem; 228 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 229 p += 512) 230 v = *p; 231 232 shmif_lockbus(sc->sc_busmem); 233 /* we're first? initialize bus */ 234 if (sc->sc_busmem->shm_magic == 0) { 235 sc->sc_busmem->shm_magic = SHMIF_MAGIC; 236 sc->sc_busmem->shm_first = BUSMEM_DATASIZE; 237 } 238 239 sc->sc_nextpacket = sc->sc_busmem->shm_last; 240 sc->sc_devgen = sc->sc_busmem->shm_gen; 241 242 #ifdef PREFAULT_RW 243 for (p = (uint8_t *)sc->sc_busmem; 244 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 245 p += PAGE_SIZE) { 246 v = *p; 247 *p = v; 248 } 249 #endif 250 shmif_unlockbus(sc->sc_busmem); 251 252 sc->sc_kq = rumpuser_writewatchfile_setup(-1, memfd, 0, &error); 253 if (sc->sc_kq == -1) { 254 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 255 return error; 256 } 257 258 sc->sc_memfd = memfd; 259 260 return error; 261 } 262 263 static void 264 finibackend(struct shmif_sc *sc) 265 { 266 267 if (sc->sc_backfile == NULL) 268 return; 269 270 if (sc->sc_backfile) { 271 kmem_free(sc->sc_backfile, sc->sc_backfilelen); 272 sc->sc_backfile = NULL; 273 sc->sc_backfilelen = 0; 274 } 275 276 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 277 rumpuser_close(sc->sc_memfd, NULL); 278 rumpuser_close(sc->sc_kq, NULL); 279 280 sc->sc_memfd = -1; 281 } 282 283 int 284 rump_shmif_create(const char *path, int *ifnum) 285 { 286 struct shmif_sc *sc; 287 int unit, error; 288 int memfd = -1; /* XXXgcc */ 289 290 if (path) { 291 memfd = rumpuser_open(path, O_RDWR | O_CREAT, &error); 292 if (memfd == -1) 293 return error; 294 } 295 296 unit = vmem_xalloc(shmif_units, 1, 0, 0, 0, 0, 0, 297 VM_INSTANTFIT | VM_SLEEP) - 1; 298 299 if ((error = allocif(unit, &sc)) != 0) { 300 if (path) 301 rumpuser_close(memfd, NULL); 302 return error; 303 } 304 305 if (!path) 306 goto out; 307 308 error = initbackend(sc, memfd); 309 if (error) { 310 shmif_unclone(&sc->sc_ec.ec_if); 311 return error; 312 } 313 314 sc->sc_backfilelen = strlen(path)+1; 315 sc->sc_backfile = kmem_alloc(sc->sc_backfilelen, KM_SLEEP); 316 strcpy(sc->sc_backfile, path); 317 318 out: 319 if (ifnum) 320 *ifnum = unit; 321 322 return 0; 323 } 324 325 static int 326 shmif_clone(struct if_clone *ifc, int unit) 327 { 328 int unit2; 329 330 /* 331 * Ok, we know the unit number, but we must still reserve it. 332 * Otherwise the wildcard-side of things might get the same one. 333 * This is slightly offset-happy due to vmem. First, we offset 334 * the range of unit numbers by +1 since vmem cannot deal with 335 * ranges starting from 0. Second, since vmem_xalloc() allocates 336 * from [min,max) (half-*open* interval), we need to add one extra 337 * to the one extra we add to maxaddr. Talk about uuuh. 338 */ 339 unit2 = vmem_xalloc(shmif_units, 1, 0, 0, 0, unit+1, unit+3, 340 VM_SLEEP | VM_INSTANTFIT); 341 KASSERT(unit2-1 == unit); 342 343 return allocif(unit, NULL); 344 } 345 346 static int 347 shmif_unclone(struct ifnet *ifp) 348 { 349 struct shmif_sc *sc = ifp->if_softc; 350 351 shmif_stop(ifp, 1); 352 if_down(ifp); 353 finibackend(sc); 354 355 mutex_enter(&sc->sc_mtx); 356 sc->sc_dying = true; 357 cv_broadcast(&sc->sc_cv); 358 mutex_exit(&sc->sc_mtx); 359 360 if (sc->sc_rcvl) 361 kthread_join(sc->sc_rcvl); 362 sc->sc_rcvl = NULL; 363 364 vmem_xfree(shmif_units, sc->sc_unit+1, 1); 365 366 ether_ifdetach(ifp); 367 if_detach(ifp); 368 369 cv_destroy(&sc->sc_cv); 370 mutex_destroy(&sc->sc_mtx); 371 372 kmem_free(sc, sizeof(*sc)); 373 374 return 0; 375 } 376 377 static int 378 shmif_init(struct ifnet *ifp) 379 { 380 struct shmif_sc *sc = ifp->if_softc; 381 int error = 0; 382 383 if (sc->sc_memfd == -1) 384 return ENXIO; 385 KASSERT(sc->sc_busmem); 386 387 ifp->if_flags |= IFF_RUNNING; 388 389 mutex_enter(&sc->sc_mtx); 390 sc->sc_nextpacket = sc->sc_busmem->shm_last; 391 sc->sc_devgen = sc->sc_busmem->shm_gen; 392 393 cv_broadcast(&sc->sc_cv); 394 mutex_exit(&sc->sc_mtx); 395 396 return error; 397 } 398 399 static int 400 shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 401 { 402 struct shmif_sc *sc = ifp->if_softc; 403 struct ifdrv *ifd; 404 char *path; 405 int s, rv, memfd; 406 407 s = splnet(); 408 switch (cmd) { 409 case SIOCGLINKSTR: 410 ifd = data; 411 412 if (sc->sc_backfilelen == 0) { 413 rv = ENOENT; 414 break; 415 } 416 417 ifd->ifd_len = sc->sc_backfilelen; 418 if (ifd->ifd_cmd == IFLINKSTR_QUERYLEN) { 419 rv = 0; 420 break; 421 } 422 423 if (ifd->ifd_cmd != 0) { 424 rv = EINVAL; 425 break; 426 } 427 428 rv = copyoutstr(sc->sc_backfile, ifd->ifd_data, 429 MIN(sc->sc_backfilelen, ifd->ifd_len), NULL); 430 break; 431 case SIOCSLINKSTR: 432 if (ifp->if_flags & IFF_UP) { 433 rv = EBUSY; 434 break; 435 } 436 437 ifd = data; 438 if (ifd->ifd_cmd == IFLINKSTR_UNSET) { 439 finibackend(sc); 440 rv = 0; 441 break; 442 } else if (ifd->ifd_cmd != 0) { 443 rv = EINVAL; 444 break; 445 } else if (sc->sc_backfile) { 446 rv = EBUSY; 447 break; 448 } 449 450 if (ifd->ifd_len > MAXPATHLEN) { 451 rv = E2BIG; 452 break; 453 } else if (ifd->ifd_len < 1) { 454 rv = EINVAL; 455 break; 456 } 457 458 path = kmem_alloc(ifd->ifd_len, KM_SLEEP); 459 rv = copyinstr(ifd->ifd_data, path, ifd->ifd_len, NULL); 460 if (rv) { 461 kmem_free(path, ifd->ifd_len); 462 break; 463 } 464 memfd = rumpuser_open(path, O_RDWR | O_CREAT, &rv); 465 if (memfd == -1) { 466 kmem_free(path, ifd->ifd_len); 467 break; 468 } 469 rv = initbackend(sc, memfd); 470 if (rv) { 471 kmem_free(path, ifd->ifd_len); 472 rumpuser_close(memfd, NULL); 473 break; 474 } 475 sc->sc_backfile = path; 476 sc->sc_backfilelen = ifd->ifd_len; 477 478 break; 479 default: 480 rv = ether_ioctl(ifp, cmd, data); 481 if (rv == ENETRESET) 482 rv = 0; 483 break; 484 } 485 splx(s); 486 487 return rv; 488 } 489 490 /* send everything in-context since it's just a matter of mem-to-mem copy */ 491 static void 492 shmif_start(struct ifnet *ifp) 493 { 494 struct shmif_sc *sc = ifp->if_softc; 495 struct shmif_mem *busmem = sc->sc_busmem; 496 struct mbuf *m, *m0; 497 uint32_t dataoff; 498 uint32_t pktsize, pktwrote; 499 bool wrote = false; 500 bool wrap; 501 int error; 502 503 ifp->if_flags |= IFF_OACTIVE; 504 505 for (;;) { 506 struct shmif_pkthdr sp; 507 struct timeval tv; 508 509 IF_DEQUEUE(&ifp->if_snd, m0); 510 if (m0 == NULL) { 511 break; 512 } 513 514 pktsize = 0; 515 for (m = m0; m != NULL; m = m->m_next) { 516 pktsize += m->m_len; 517 } 518 KASSERT(pktsize <= ETHERMTU + ETHER_HDR_LEN); 519 520 getmicrouptime(&tv); 521 sp.sp_len = pktsize; 522 sp.sp_sec = tv.tv_sec; 523 sp.sp_usec = tv.tv_usec; 524 525 bpf_mtap(ifp, m0); 526 527 shmif_lockbus(busmem); 528 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 529 busmem->shm_last = shmif_nextpktoff(busmem, busmem->shm_last); 530 531 wrap = false; 532 dataoff = shmif_buswrite(busmem, 533 busmem->shm_last, &sp, sizeof(sp), &wrap); 534 pktwrote = 0; 535 for (m = m0; m != NULL; m = m->m_next) { 536 pktwrote += m->m_len; 537 dataoff = shmif_buswrite(busmem, dataoff, 538 mtod(m, void *), m->m_len, &wrap); 539 } 540 KASSERT(pktwrote == pktsize); 541 if (wrap) { 542 busmem->shm_gen++; 543 DPRINTF(("bus generation now %d\n", busmem->shm_gen)); 544 } 545 shmif_unlockbus(busmem); 546 547 m_freem(m0); 548 wrote = true; 549 550 DPRINTF(("shmif_start: send %d bytes at off %d\n", 551 pktsize, busmem->shm_last)); 552 } 553 554 ifp->if_flags &= ~IFF_OACTIVE; 555 556 /* wakeup? */ 557 if (wrote) 558 rumpuser_pwrite(sc->sc_memfd, 559 &busversion, sizeof(busversion), IFMEM_WAKEUP, &error); 560 } 561 562 static void 563 shmif_stop(struct ifnet *ifp, int disable) 564 { 565 struct shmif_sc *sc = ifp->if_softc; 566 567 ifp->if_flags &= ~IFF_RUNNING; 568 membar_producer(); 569 570 /* 571 * wakeup thread. this will of course wake up all bus 572 * listeners, but that's life. 573 */ 574 if (sc->sc_memfd != -1) 575 rumpuser_pwrite(sc->sc_memfd, 576 &busversion, sizeof(busversion), IFMEM_WAKEUP, NULL); 577 } 578 579 580 /* 581 * Check if we have been sleeping too long. Basically, 582 * our in-sc nextpkt must by first <= nextpkt <= last"+1". 583 * We use the fact that first is guaranteed to never overlap 584 * with the last frame in the ring. 585 */ 586 static __inline bool 587 stillvalid_p(struct shmif_sc *sc) 588 { 589 struct shmif_mem *busmem = sc->sc_busmem; 590 unsigned gendiff = busmem->shm_gen - sc->sc_devgen; 591 uint32_t lastoff, devoff; 592 593 KASSERT(busmem->shm_first != busmem->shm_last); 594 595 /* normalize onto a 2x busmem chunk */ 596 devoff = sc->sc_nextpacket; 597 lastoff = shmif_nextpktoff(busmem, busmem->shm_last); 598 599 /* trivial case */ 600 if (gendiff > 1) 601 return false; 602 KASSERT(gendiff <= 1); 603 604 /* Normalize onto 2x busmem chunk */ 605 if (busmem->shm_first >= lastoff) { 606 lastoff += BUSMEM_DATASIZE; 607 if (gendiff == 0) 608 devoff += BUSMEM_DATASIZE; 609 } else { 610 if (gendiff) 611 return false; 612 } 613 614 return devoff >= busmem->shm_first && devoff <= lastoff; 615 } 616 617 static void 618 shmif_rcv(void *arg) 619 { 620 struct ifnet *ifp = arg; 621 struct shmif_sc *sc = ifp->if_softc; 622 struct shmif_mem *busmem; 623 struct mbuf *m = NULL; 624 struct ether_header *eth; 625 uint32_t nextpkt; 626 bool wrap, passup; 627 int error; 628 629 reup: 630 mutex_enter(&sc->sc_mtx); 631 while ((ifp->if_flags & IFF_RUNNING) == 0 && !sc->sc_dying) 632 cv_wait(&sc->sc_cv, &sc->sc_mtx); 633 mutex_exit(&sc->sc_mtx); 634 635 busmem = sc->sc_busmem; 636 637 while (ifp->if_flags & IFF_RUNNING) { 638 struct shmif_pkthdr sp; 639 640 if (m == NULL) { 641 m = m_gethdr(M_WAIT, MT_DATA); 642 MCLGET(m, M_WAIT); 643 } 644 645 DPRINTF(("waiting %d/%d\n", sc->sc_nextpacket, sc->sc_devgen)); 646 KASSERT(m->m_flags & M_EXT); 647 648 shmif_lockbus(busmem); 649 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 650 KASSERT(busmem->shm_gen >= sc->sc_devgen); 651 652 /* need more data? */ 653 if (sc->sc_devgen == busmem->shm_gen && 654 shmif_nextpktoff(busmem, busmem->shm_last) 655 == sc->sc_nextpacket) { 656 shmif_unlockbus(busmem); 657 error = 0; 658 rumpuser_writewatchfile_wait(sc->sc_kq, NULL, &error); 659 if (__predict_false(error)) 660 printf("shmif_rcv: wait failed %d\n", error); 661 membar_consumer(); 662 continue; 663 } 664 665 if (stillvalid_p(sc)) { 666 nextpkt = sc->sc_nextpacket; 667 } else { 668 KASSERT(busmem->shm_gen > 0); 669 nextpkt = busmem->shm_first; 670 if (busmem->shm_first > busmem->shm_last) 671 sc->sc_devgen = busmem->shm_gen - 1; 672 else 673 sc->sc_devgen = busmem->shm_gen; 674 DPRINTF(("dev %p overrun, new data: %d/%d\n", 675 sc, nextpkt, sc->sc_devgen)); 676 } 677 678 /* 679 * If our read pointer is ahead the bus last write, our 680 * generation must be one behind. 681 */ 682 KASSERT(!(nextpkt > busmem->shm_last 683 && sc->sc_devgen == busmem->shm_gen)); 684 685 wrap = false; 686 nextpkt = shmif_busread(busmem, &sp, 687 nextpkt, sizeof(sp), &wrap); 688 KASSERT(sp.sp_len <= ETHERMTU + ETHER_HDR_LEN); 689 nextpkt = shmif_busread(busmem, mtod(m, void *), 690 nextpkt, sp.sp_len, &wrap); 691 692 DPRINTF(("shmif_rcv: read packet of length %d at %d\n", 693 sp.sp_len, nextpkt)); 694 695 sc->sc_nextpacket = nextpkt; 696 shmif_unlockbus(sc->sc_busmem); 697 698 if (wrap) { 699 sc->sc_devgen++; 700 DPRINTF(("dev %p generation now %d\n", 701 sc, sc->sc_devgen)); 702 } 703 704 m->m_len = m->m_pkthdr.len = sp.sp_len; 705 m->m_pkthdr.rcvif = ifp; 706 707 /* 708 * Test if we want to pass the packet upwards 709 */ 710 eth = mtod(m, struct ether_header *); 711 if (memcmp(eth->ether_dhost, CLLADDR(ifp->if_sadl), 712 ETHER_ADDR_LEN) == 0) { 713 passup = true; 714 } else if (memcmp(eth->ether_dhost, etherbroadcastaddr, 715 ETHER_ADDR_LEN) == 0) { 716 passup = true; 717 } else if (ifp->if_flags & IFF_PROMISC) { 718 m->m_flags |= M_PROMISC; 719 passup = true; 720 } else { 721 passup = false; 722 } 723 724 if (passup) { 725 KERNEL_LOCK(1, NULL); 726 bpf_mtap(ifp, m); 727 ifp->if_input(ifp, m); 728 KERNEL_UNLOCK_ONE(NULL); 729 m = NULL; 730 } 731 /* else: reuse mbuf for a future packet */ 732 } 733 m_freem(m); 734 m = NULL; 735 736 if (!sc->sc_dying) 737 goto reup; 738 739 kthread_exit(0); 740 } 741