if_shmem.c revision 1.43
1 /* $NetBSD: if_shmem.c,v 1.43 2011/09/02 22:25:08 dyoung 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 1.43 2011/09/02 22:25:08 dyoung 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_MUSTJOIN, 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 vmem_addr_t t; 288 int unit, error; 289 int memfd = -1; /* XXXgcc */ 290 291 if (path) { 292 memfd = rumpuser_open(path, O_RDWR | O_CREAT, &error); 293 if (memfd == -1) 294 return error; 295 } 296 297 error = vmem_xalloc(shmif_units, 1, 0, 0, 0, 298 VMEM_ADDR_MIN, VMEM_ADDR_MAX, VM_INSTANTFIT | VM_SLEEP, &t); 299 300 if (error != 0) { 301 if (path) 302 rumpuser_close(memfd, NULL); 303 return error; 304 } 305 306 unit = t - 1; 307 308 if ((error = allocif(unit, &sc)) != 0) { 309 if (path) 310 rumpuser_close(memfd, NULL); 311 return error; 312 } 313 314 if (!path) 315 goto out; 316 317 error = initbackend(sc, memfd); 318 if (error) { 319 shmif_unclone(&sc->sc_ec.ec_if); 320 return error; 321 } 322 323 sc->sc_backfilelen = strlen(path)+1; 324 sc->sc_backfile = kmem_alloc(sc->sc_backfilelen, KM_SLEEP); 325 strcpy(sc->sc_backfile, path); 326 327 out: 328 if (ifnum) 329 *ifnum = unit; 330 331 return 0; 332 } 333 334 static int 335 shmif_clone(struct if_clone *ifc, int unit) 336 { 337 int rc; 338 vmem_addr_t unit2; 339 340 /* 341 * Ok, we know the unit number, but we must still reserve it. 342 * Otherwise the wildcard-side of things might get the same one. 343 * This is slightly offset-happy due to vmem. First, we offset 344 * the range of unit numbers by +1 since vmem cannot deal with 345 * ranges starting from 0. Talk about uuuh. 346 */ 347 rc = vmem_xalloc(shmif_units, 1, 0, 0, 0, unit+1, unit+1, 348 VM_SLEEP | VM_INSTANTFIT, &unit2); 349 KASSERT(rc == 0 && unit2-1 == unit); 350 351 return allocif(unit, NULL); 352 } 353 354 static int 355 shmif_unclone(struct ifnet *ifp) 356 { 357 struct shmif_sc *sc = ifp->if_softc; 358 359 shmif_stop(ifp, 1); 360 if_down(ifp); 361 finibackend(sc); 362 363 mutex_enter(&sc->sc_mtx); 364 sc->sc_dying = true; 365 cv_broadcast(&sc->sc_cv); 366 mutex_exit(&sc->sc_mtx); 367 368 if (sc->sc_rcvl) 369 kthread_join(sc->sc_rcvl); 370 sc->sc_rcvl = NULL; 371 372 vmem_xfree(shmif_units, sc->sc_unit+1, 1); 373 374 ether_ifdetach(ifp); 375 if_detach(ifp); 376 377 cv_destroy(&sc->sc_cv); 378 mutex_destroy(&sc->sc_mtx); 379 380 kmem_free(sc, sizeof(*sc)); 381 382 return 0; 383 } 384 385 static int 386 shmif_init(struct ifnet *ifp) 387 { 388 struct shmif_sc *sc = ifp->if_softc; 389 int error = 0; 390 391 if (sc->sc_memfd == -1) 392 return ENXIO; 393 KASSERT(sc->sc_busmem); 394 395 ifp->if_flags |= IFF_RUNNING; 396 397 mutex_enter(&sc->sc_mtx); 398 sc->sc_nextpacket = sc->sc_busmem->shm_last; 399 sc->sc_devgen = sc->sc_busmem->shm_gen; 400 401 cv_broadcast(&sc->sc_cv); 402 mutex_exit(&sc->sc_mtx); 403 404 return error; 405 } 406 407 static int 408 shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 409 { 410 struct shmif_sc *sc = ifp->if_softc; 411 struct ifdrv *ifd; 412 char *path; 413 int s, rv, memfd; 414 415 s = splnet(); 416 switch (cmd) { 417 case SIOCGLINKSTR: 418 ifd = data; 419 420 if (sc->sc_backfilelen == 0) { 421 rv = ENOENT; 422 break; 423 } 424 425 ifd->ifd_len = sc->sc_backfilelen; 426 if (ifd->ifd_cmd == IFLINKSTR_QUERYLEN) { 427 rv = 0; 428 break; 429 } 430 431 if (ifd->ifd_cmd != 0) { 432 rv = EINVAL; 433 break; 434 } 435 436 rv = copyoutstr(sc->sc_backfile, ifd->ifd_data, 437 MIN(sc->sc_backfilelen, ifd->ifd_len), NULL); 438 break; 439 case SIOCSLINKSTR: 440 if (ifp->if_flags & IFF_UP) { 441 rv = EBUSY; 442 break; 443 } 444 445 ifd = data; 446 if (ifd->ifd_cmd == IFLINKSTR_UNSET) { 447 finibackend(sc); 448 rv = 0; 449 break; 450 } else if (ifd->ifd_cmd != 0) { 451 rv = EINVAL; 452 break; 453 } else if (sc->sc_backfile) { 454 rv = EBUSY; 455 break; 456 } 457 458 if (ifd->ifd_len > MAXPATHLEN) { 459 rv = E2BIG; 460 break; 461 } else if (ifd->ifd_len < 1) { 462 rv = EINVAL; 463 break; 464 } 465 466 path = kmem_alloc(ifd->ifd_len, KM_SLEEP); 467 rv = copyinstr(ifd->ifd_data, path, ifd->ifd_len, NULL); 468 if (rv) { 469 kmem_free(path, ifd->ifd_len); 470 break; 471 } 472 memfd = rumpuser_open(path, O_RDWR | O_CREAT, &rv); 473 if (memfd == -1) { 474 kmem_free(path, ifd->ifd_len); 475 break; 476 } 477 rv = initbackend(sc, memfd); 478 if (rv) { 479 kmem_free(path, ifd->ifd_len); 480 rumpuser_close(memfd, NULL); 481 break; 482 } 483 sc->sc_backfile = path; 484 sc->sc_backfilelen = ifd->ifd_len; 485 486 break; 487 default: 488 rv = ether_ioctl(ifp, cmd, data); 489 if (rv == ENETRESET) 490 rv = 0; 491 break; 492 } 493 splx(s); 494 495 return rv; 496 } 497 498 /* send everything in-context since it's just a matter of mem-to-mem copy */ 499 static void 500 shmif_start(struct ifnet *ifp) 501 { 502 struct shmif_sc *sc = ifp->if_softc; 503 struct shmif_mem *busmem = sc->sc_busmem; 504 struct mbuf *m, *m0; 505 uint32_t dataoff; 506 uint32_t pktsize, pktwrote; 507 bool wrote = false; 508 bool wrap; 509 int error; 510 511 ifp->if_flags |= IFF_OACTIVE; 512 513 for (;;) { 514 struct shmif_pkthdr sp; 515 struct timeval tv; 516 517 IF_DEQUEUE(&ifp->if_snd, m0); 518 if (m0 == NULL) { 519 break; 520 } 521 522 pktsize = 0; 523 for (m = m0; m != NULL; m = m->m_next) { 524 pktsize += m->m_len; 525 } 526 KASSERT(pktsize <= ETHERMTU + ETHER_HDR_LEN); 527 528 getmicrouptime(&tv); 529 sp.sp_len = pktsize; 530 sp.sp_sec = tv.tv_sec; 531 sp.sp_usec = tv.tv_usec; 532 533 bpf_mtap(ifp, m0); 534 535 shmif_lockbus(busmem); 536 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 537 busmem->shm_last = shmif_nextpktoff(busmem, busmem->shm_last); 538 539 wrap = false; 540 dataoff = shmif_buswrite(busmem, 541 busmem->shm_last, &sp, sizeof(sp), &wrap); 542 pktwrote = 0; 543 for (m = m0; m != NULL; m = m->m_next) { 544 pktwrote += m->m_len; 545 dataoff = shmif_buswrite(busmem, dataoff, 546 mtod(m, void *), m->m_len, &wrap); 547 } 548 KASSERT(pktwrote == pktsize); 549 if (wrap) { 550 busmem->shm_gen++; 551 DPRINTF(("bus generation now %d\n", busmem->shm_gen)); 552 } 553 shmif_unlockbus(busmem); 554 555 m_freem(m0); 556 wrote = true; 557 558 DPRINTF(("shmif_start: send %d bytes at off %d\n", 559 pktsize, busmem->shm_last)); 560 } 561 562 ifp->if_flags &= ~IFF_OACTIVE; 563 564 /* wakeup? */ 565 if (wrote) 566 rumpuser_pwrite(sc->sc_memfd, 567 &busversion, sizeof(busversion), IFMEM_WAKEUP, &error); 568 } 569 570 static void 571 shmif_stop(struct ifnet *ifp, int disable) 572 { 573 struct shmif_sc *sc = ifp->if_softc; 574 575 ifp->if_flags &= ~IFF_RUNNING; 576 membar_producer(); 577 578 /* 579 * wakeup thread. this will of course wake up all bus 580 * listeners, but that's life. 581 */ 582 if (sc->sc_memfd != -1) 583 rumpuser_pwrite(sc->sc_memfd, 584 &busversion, sizeof(busversion), IFMEM_WAKEUP, NULL); 585 } 586 587 588 /* 589 * Check if we have been sleeping too long. Basically, 590 * our in-sc nextpkt must by first <= nextpkt <= last"+1". 591 * We use the fact that first is guaranteed to never overlap 592 * with the last frame in the ring. 593 */ 594 static __inline bool 595 stillvalid_p(struct shmif_sc *sc) 596 { 597 struct shmif_mem *busmem = sc->sc_busmem; 598 unsigned gendiff = busmem->shm_gen - sc->sc_devgen; 599 uint32_t lastoff, devoff; 600 601 KASSERT(busmem->shm_first != busmem->shm_last); 602 603 /* normalize onto a 2x busmem chunk */ 604 devoff = sc->sc_nextpacket; 605 lastoff = shmif_nextpktoff(busmem, busmem->shm_last); 606 607 /* trivial case */ 608 if (gendiff > 1) 609 return false; 610 KASSERT(gendiff <= 1); 611 612 /* Normalize onto 2x busmem chunk */ 613 if (busmem->shm_first >= lastoff) { 614 lastoff += BUSMEM_DATASIZE; 615 if (gendiff == 0) 616 devoff += BUSMEM_DATASIZE; 617 } else { 618 if (gendiff) 619 return false; 620 } 621 622 return devoff >= busmem->shm_first && devoff <= lastoff; 623 } 624 625 static void 626 shmif_rcv(void *arg) 627 { 628 struct ifnet *ifp = arg; 629 struct shmif_sc *sc = ifp->if_softc; 630 struct shmif_mem *busmem; 631 struct mbuf *m = NULL; 632 struct ether_header *eth; 633 uint32_t nextpkt; 634 bool wrap, passup; 635 int error; 636 637 reup: 638 mutex_enter(&sc->sc_mtx); 639 while ((ifp->if_flags & IFF_RUNNING) == 0 && !sc->sc_dying) 640 cv_wait(&sc->sc_cv, &sc->sc_mtx); 641 mutex_exit(&sc->sc_mtx); 642 643 busmem = sc->sc_busmem; 644 645 while (ifp->if_flags & IFF_RUNNING) { 646 struct shmif_pkthdr sp; 647 648 if (m == NULL) { 649 m = m_gethdr(M_WAIT, MT_DATA); 650 MCLGET(m, M_WAIT); 651 } 652 653 DPRINTF(("waiting %d/%d\n", sc->sc_nextpacket, sc->sc_devgen)); 654 KASSERT(m->m_flags & M_EXT); 655 656 shmif_lockbus(busmem); 657 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 658 KASSERT(busmem->shm_gen >= sc->sc_devgen); 659 660 /* need more data? */ 661 if (sc->sc_devgen == busmem->shm_gen && 662 shmif_nextpktoff(busmem, busmem->shm_last) 663 == sc->sc_nextpacket) { 664 shmif_unlockbus(busmem); 665 error = 0; 666 rumpuser_writewatchfile_wait(sc->sc_kq, NULL, &error); 667 if (__predict_false(error)) 668 printf("shmif_rcv: wait failed %d\n", error); 669 membar_consumer(); 670 continue; 671 } 672 673 if (stillvalid_p(sc)) { 674 nextpkt = sc->sc_nextpacket; 675 } else { 676 KASSERT(busmem->shm_gen > 0); 677 nextpkt = busmem->shm_first; 678 if (busmem->shm_first > busmem->shm_last) 679 sc->sc_devgen = busmem->shm_gen - 1; 680 else 681 sc->sc_devgen = busmem->shm_gen; 682 DPRINTF(("dev %p overrun, new data: %d/%d\n", 683 sc, nextpkt, sc->sc_devgen)); 684 } 685 686 /* 687 * If our read pointer is ahead the bus last write, our 688 * generation must be one behind. 689 */ 690 KASSERT(!(nextpkt > busmem->shm_last 691 && sc->sc_devgen == busmem->shm_gen)); 692 693 wrap = false; 694 nextpkt = shmif_busread(busmem, &sp, 695 nextpkt, sizeof(sp), &wrap); 696 KASSERT(sp.sp_len <= ETHERMTU + ETHER_HDR_LEN); 697 nextpkt = shmif_busread(busmem, mtod(m, void *), 698 nextpkt, sp.sp_len, &wrap); 699 700 DPRINTF(("shmif_rcv: read packet of length %d at %d\n", 701 sp.sp_len, nextpkt)); 702 703 sc->sc_nextpacket = nextpkt; 704 shmif_unlockbus(sc->sc_busmem); 705 706 if (wrap) { 707 sc->sc_devgen++; 708 DPRINTF(("dev %p generation now %d\n", 709 sc, sc->sc_devgen)); 710 } 711 712 m->m_len = m->m_pkthdr.len = sp.sp_len; 713 m->m_pkthdr.rcvif = ifp; 714 715 /* 716 * Test if we want to pass the packet upwards 717 */ 718 eth = mtod(m, struct ether_header *); 719 if (memcmp(eth->ether_dhost, CLLADDR(ifp->if_sadl), 720 ETHER_ADDR_LEN) == 0) { 721 passup = true; 722 } else if (memcmp(eth->ether_dhost, etherbroadcastaddr, 723 ETHER_ADDR_LEN) == 0) { 724 passup = true; 725 } else if (ifp->if_flags & IFF_PROMISC) { 726 m->m_flags |= M_PROMISC; 727 passup = true; 728 } else { 729 passup = false; 730 } 731 732 if (passup) { 733 KERNEL_LOCK(1, NULL); 734 bpf_mtap(ifp, m); 735 ifp->if_input(ifp, m); 736 KERNEL_UNLOCK_ONE(NULL); 737 m = NULL; 738 } 739 /* else: reuse mbuf for a future packet */ 740 } 741 m_freem(m); 742 m = NULL; 743 744 if (!sc->sc_dying) 745 goto reup; 746 747 kthread_exit(0); 748 } 749
Indexes created Mon Sep 22 13:09:51 GMT 2025