1 /* $NetBSD: if_shmem.c,v 1.64 2016/01/26 23:12:19 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 1.64 2016/01/26 23:12:19 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 #include <sys/cprng.h> 41 42 #include <net/bpf.h> 43 #include <net/if.h> 44 #include <net/if_dl.h> 45 #include <net/if_ether.h> 46 47 #include <netinet/in.h> 48 #include <netinet/in_var.h> 49 50 #include <rump-sys/kern.h> 51 #include <rump-sys/net.h> 52 53 #include <rump/rump.h> 54 #include <rump/rumpuser.h> 55 56 #include "shmif_user.h" 57 58 static int shmif_clone(struct if_clone *, int); 59 static int shmif_unclone(struct ifnet *); 60 61 struct if_clone shmif_cloner = 62 IF_CLONE_INITIALIZER("shmif", shmif_clone, shmif_unclone); 63 64 /* 65 * Do r/w prefault for backend pages when attaching the interface. 66 * At least logically thinking improves performance (although no 67 * mlocking is done, so they might go away). 68 */ 69 #define PREFAULT_RW 70 71 /* 72 * A virtual ethernet interface which uses shared memory from a 73 * memory mapped file as the bus. 74 */ 75 76 static int shmif_init(struct ifnet *); 77 static int shmif_ioctl(struct ifnet *, u_long, void *); 78 static void shmif_start(struct ifnet *); 79 static void shmif_stop(struct ifnet *, int); 80 81 #include "shmifvar.h" 82 83 struct shmif_sc { 84 struct ethercom sc_ec; 85 struct shmif_mem *sc_busmem; 86 int sc_memfd; 87 int sc_kq; 88 int sc_unit; 89 90 char *sc_backfile; 91 size_t sc_backfilelen; 92 93 uint64_t sc_devgen; 94 uint32_t sc_nextpacket; 95 96 kmutex_t sc_mtx; 97 kcondvar_t sc_cv; 98 99 struct lwp *sc_rcvl; 100 bool sc_dying; 101 102 uint64_t sc_uuid; 103 }; 104 105 static void shmif_rcv(void *); 106 107 #define LOCK_UNLOCKED 0 108 #define LOCK_LOCKED 1 109 #define LOCK_COOLDOWN 1001 110 111 vmem_t *shmif_units; 112 113 static void 114 dowakeup(struct shmif_sc *sc) 115 { 116 struct rumpuser_iovec iov; 117 uint32_t ver = SHMIF_VERSION; 118 size_t n; 119 120 iov.iov_base = &ver; 121 iov.iov_len = sizeof(ver); 122 rumpuser_iovwrite(sc->sc_memfd, &iov, 1, IFMEM_WAKEUP, &n); 123 } 124 125 /* 126 * This locking needs work and will misbehave severely if: 127 * 1) the backing memory has to be paged in 128 * 2) some lockholder exits while holding the lock 129 */ 130 static void 131 shmif_lockbus(struct shmif_mem *busmem) 132 { 133 int i = 0; 134 135 while (__predict_false(atomic_cas_32(&busmem->shm_lock, 136 LOCK_UNLOCKED, LOCK_LOCKED) == LOCK_LOCKED)) { 137 if (__predict_false(++i > LOCK_COOLDOWN)) { 138 /* wait 1ms */ 139 rumpuser_clock_sleep(RUMPUSER_CLOCK_RELWALL, 140 0, 1000*1000); 141 i = 0; 142 } 143 continue; 144 } 145 membar_enter(); 146 } 147 148 static void 149 shmif_unlockbus(struct shmif_mem *busmem) 150 { 151 unsigned int old __diagused; 152 153 membar_exit(); 154 old = atomic_swap_32(&busmem->shm_lock, LOCK_UNLOCKED); 155 KASSERT(old == LOCK_LOCKED); 156 } 157 158 static int 159 allocif(int unit, struct shmif_sc **scp) 160 { 161 uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0xa0, 0x00, 0x00, 0x00, 0x00 }; 162 struct shmif_sc *sc; 163 struct ifnet *ifp; 164 uint32_t randnum; 165 int error; 166 167 randnum = cprng_fast32(); 168 memcpy(&enaddr[2], &randnum, sizeof(randnum)); 169 170 sc = kmem_zalloc(sizeof(*sc), KM_SLEEP); 171 sc->sc_memfd = -1; 172 sc->sc_unit = unit; 173 sc->sc_uuid = cprng_fast64(); 174 175 ifp = &sc->sc_ec.ec_if; 176 177 snprintf(ifp->if_xname, sizeof(ifp->if_xname), "shmif%d", unit); 178 ifp->if_softc = sc; 179 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 180 ifp->if_init = shmif_init; 181 ifp->if_ioctl = shmif_ioctl; 182 ifp->if_start = shmif_start; 183 ifp->if_stop = shmif_stop; 184 ifp->if_mtu = ETHERMTU; 185 ifp->if_dlt = DLT_EN10MB; 186 187 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE); 188 cv_init(&sc->sc_cv, "shmifcv"); 189 190 if_attach(ifp); 191 ether_ifattach(ifp, enaddr); 192 193 aprint_verbose("shmif%d: Ethernet address %s\n", 194 unit, ether_sprintf(enaddr)); 195 196 if (scp) 197 *scp = sc; 198 199 error = 0; 200 if (rump_threads) { 201 error = kthread_create(PRI_NONE, 202 KTHREAD_MPSAFE | KTHREAD_MUSTJOIN, NULL, 203 shmif_rcv, ifp, &sc->sc_rcvl, "shmif"); 204 } else { 205 printf("WARNING: threads not enabled, shmif NOT working\n"); 206 } 207 208 if (error) { 209 shmif_unclone(ifp); 210 } 211 212 return error; 213 } 214 215 static int 216 initbackend(struct shmif_sc *sc, int memfd) 217 { 218 volatile uint8_t v; 219 volatile uint8_t *p; 220 void *mem; 221 int error; 222 223 error = rumpcomp_shmif_mmap(memfd, BUSMEM_SIZE, &mem); 224 if (error) 225 return error; 226 sc->sc_busmem = mem; 227 228 if (sc->sc_busmem->shm_magic 229 && sc->sc_busmem->shm_magic != SHMIF_MAGIC) { 230 printf("bus is not magical"); 231 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 232 return ENOEXEC; 233 } 234 235 /* 236 * Prefault in pages to minimize runtime penalty with buslock. 237 * Use 512 instead of PAGE_SIZE to make sure we catch cases where 238 * rump kernel PAGE_SIZE > host page size. 239 */ 240 for (p = (uint8_t *)sc->sc_busmem; 241 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 242 p += 512) 243 v = *p; 244 245 shmif_lockbus(sc->sc_busmem); 246 /* we're first? initialize bus */ 247 if (sc->sc_busmem->shm_magic == 0) { 248 sc->sc_busmem->shm_magic = SHMIF_MAGIC; 249 sc->sc_busmem->shm_first = BUSMEM_DATASIZE; 250 } 251 252 sc->sc_nextpacket = sc->sc_busmem->shm_last; 253 sc->sc_devgen = sc->sc_busmem->shm_gen; 254 255 #ifdef PREFAULT_RW 256 for (p = (uint8_t *)sc->sc_busmem; 257 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 258 p += PAGE_SIZE) { 259 v = *p; 260 *p = v; 261 } 262 #endif 263 shmif_unlockbus(sc->sc_busmem); 264 265 sc->sc_kq = -1; 266 error = rumpcomp_shmif_watchsetup(&sc->sc_kq, memfd); 267 if (error) { 268 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 269 return error; 270 } 271 272 sc->sc_memfd = memfd; 273 274 return error; 275 } 276 277 static void 278 finibackend(struct shmif_sc *sc) 279 { 280 281 if (sc->sc_backfile == NULL) 282 return; 283 284 if (sc->sc_backfile) { 285 kmem_free(sc->sc_backfile, sc->sc_backfilelen); 286 sc->sc_backfile = NULL; 287 sc->sc_backfilelen = 0; 288 } 289 290 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 291 rumpuser_close(sc->sc_memfd); 292 rumpuser_close(sc->sc_kq); 293 294 sc->sc_memfd = -1; 295 } 296 297 int 298 rump_shmif_create(const char *path, int *ifnum) 299 { 300 struct shmif_sc *sc; 301 vmem_addr_t t; 302 int unit, error; 303 int memfd = -1; /* XXXgcc */ 304 305 if (path) { 306 error = rumpuser_open(path, 307 RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd); 308 if (error) 309 return error; 310 } 311 312 error = vmem_xalloc(shmif_units, 1, 0, 0, 0, 313 VMEM_ADDR_MIN, VMEM_ADDR_MAX, VM_INSTANTFIT | VM_SLEEP, &t); 314 315 if (error != 0) { 316 if (path) 317 rumpuser_close(memfd); 318 return error; 319 } 320 321 unit = t - 1; 322 323 if ((error = allocif(unit, &sc)) != 0) { 324 if (path) 325 rumpuser_close(memfd); 326 return error; 327 } 328 329 if (!path) 330 goto out; 331 332 error = initbackend(sc, memfd); 333 if (error) { 334 shmif_unclone(&sc->sc_ec.ec_if); 335 return error; 336 } 337 338 sc->sc_backfilelen = strlen(path)+1; 339 sc->sc_backfile = kmem_alloc(sc->sc_backfilelen, KM_SLEEP); 340 strcpy(sc->sc_backfile, path); 341 342 out: 343 if (ifnum) 344 *ifnum = unit; 345 346 return 0; 347 } 348 349 static int 350 shmif_clone(struct if_clone *ifc, int unit) 351 { 352 int rc __diagused; 353 vmem_addr_t unit2; 354 355 /* 356 * Ok, we know the unit number, but we must still reserve it. 357 * Otherwise the wildcard-side of things might get the same one. 358 * This is slightly offset-happy due to vmem. First, we offset 359 * the range of unit numbers by +1 since vmem cannot deal with 360 * ranges starting from 0. Talk about uuuh. 361 */ 362 rc = vmem_xalloc(shmif_units, 1, 0, 0, 0, unit+1, unit+1, 363 VM_SLEEP | VM_INSTANTFIT, &unit2); 364 KASSERT(rc == 0 && unit2-1 == unit); 365 366 return allocif(unit, NULL); 367 } 368 369 static int 370 shmif_unclone(struct ifnet *ifp) 371 { 372 struct shmif_sc *sc = ifp->if_softc; 373 374 shmif_stop(ifp, 1); 375 if_down(ifp); 376 finibackend(sc); 377 378 mutex_enter(&sc->sc_mtx); 379 sc->sc_dying = true; 380 cv_broadcast(&sc->sc_cv); 381 mutex_exit(&sc->sc_mtx); 382 383 if (sc->sc_rcvl) 384 kthread_join(sc->sc_rcvl); 385 sc->sc_rcvl = NULL; 386 387 vmem_xfree(shmif_units, sc->sc_unit+1, 1); 388 389 ether_ifdetach(ifp); 390 if_detach(ifp); 391 392 cv_destroy(&sc->sc_cv); 393 mutex_destroy(&sc->sc_mtx); 394 395 kmem_free(sc, sizeof(*sc)); 396 397 return 0; 398 } 399 400 static int 401 shmif_init(struct ifnet *ifp) 402 { 403 struct shmif_sc *sc = ifp->if_softc; 404 int error = 0; 405 406 if (sc->sc_memfd == -1) 407 return ENXIO; 408 KASSERT(sc->sc_busmem); 409 410 ifp->if_flags |= IFF_RUNNING; 411 412 mutex_enter(&sc->sc_mtx); 413 sc->sc_nextpacket = sc->sc_busmem->shm_last; 414 sc->sc_devgen = sc->sc_busmem->shm_gen; 415 416 cv_broadcast(&sc->sc_cv); 417 mutex_exit(&sc->sc_mtx); 418 419 return error; 420 } 421 422 static int 423 shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 424 { 425 struct shmif_sc *sc = ifp->if_softc; 426 struct ifdrv *ifd; 427 char *path; 428 int s, rv, memfd; 429 430 s = splnet(); 431 switch (cmd) { 432 case SIOCGLINKSTR: 433 ifd = data; 434 435 if (sc->sc_backfilelen == 0) { 436 rv = ENOENT; 437 break; 438 } 439 440 ifd->ifd_len = sc->sc_backfilelen; 441 if (ifd->ifd_cmd == IFLINKSTR_QUERYLEN) { 442 rv = 0; 443 break; 444 } 445 446 if (ifd->ifd_cmd != 0) { 447 rv = EINVAL; 448 break; 449 } 450 451 rv = copyoutstr(sc->sc_backfile, ifd->ifd_data, 452 MIN(sc->sc_backfilelen, ifd->ifd_len), NULL); 453 break; 454 case SIOCSLINKSTR: 455 if (ifp->if_flags & IFF_UP) { 456 rv = EBUSY; 457 break; 458 } 459 460 ifd = data; 461 if (ifd->ifd_cmd == IFLINKSTR_UNSET) { 462 finibackend(sc); 463 rv = 0; 464 break; 465 } else if (ifd->ifd_cmd != 0) { 466 rv = EINVAL; 467 break; 468 } else if (sc->sc_backfile) { 469 rv = EBUSY; 470 break; 471 } 472 473 if (ifd->ifd_len > MAXPATHLEN) { 474 rv = E2BIG; 475 break; 476 } else if (ifd->ifd_len < 1) { 477 rv = EINVAL; 478 break; 479 } 480 481 path = kmem_alloc(ifd->ifd_len, KM_SLEEP); 482 rv = copyinstr(ifd->ifd_data, path, ifd->ifd_len, NULL); 483 if (rv) { 484 kmem_free(path, ifd->ifd_len); 485 break; 486 } 487 rv = rumpuser_open(path, 488 RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd); 489 if (rv) { 490 kmem_free(path, ifd->ifd_len); 491 break; 492 } 493 rv = initbackend(sc, memfd); 494 if (rv) { 495 kmem_free(path, ifd->ifd_len); 496 rumpuser_close(memfd); 497 break; 498 } 499 sc->sc_backfile = path; 500 sc->sc_backfilelen = ifd->ifd_len; 501 502 break; 503 default: 504 rv = ether_ioctl(ifp, cmd, data); 505 if (rv == ENETRESET) 506 rv = 0; 507 break; 508 } 509 splx(s); 510 511 return rv; 512 } 513 514 /* send everything in-context since it's just a matter of mem-to-mem copy */ 515 static void 516 shmif_start(struct ifnet *ifp) 517 { 518 struct shmif_sc *sc = ifp->if_softc; 519 struct shmif_mem *busmem = sc->sc_busmem; 520 struct mbuf *m, *m0; 521 uint32_t dataoff; 522 uint32_t pktsize, pktwrote; 523 bool wrote = false; 524 bool wrap; 525 526 ifp->if_flags |= IFF_OACTIVE; 527 528 for (;;) { 529 struct shmif_pkthdr sp; 530 struct timeval tv; 531 532 IF_DEQUEUE(&ifp->if_snd, m0); 533 if (m0 == NULL) { 534 break; 535 } 536 537 pktsize = 0; 538 for (m = m0; m != NULL; m = m->m_next) { 539 pktsize += m->m_len; 540 } 541 KASSERT(pktsize <= ETHERMTU + ETHER_HDR_LEN); 542 543 getmicrouptime(&tv); 544 sp.sp_len = pktsize; 545 sp.sp_sec = tv.tv_sec; 546 sp.sp_usec = tv.tv_usec; 547 sp.sp_sender = sc->sc_uuid; 548 549 bpf_mtap(ifp, m0); 550 551 shmif_lockbus(busmem); 552 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 553 busmem->shm_last = shmif_nextpktoff(busmem, busmem->shm_last); 554 555 wrap = false; 556 dataoff = shmif_buswrite(busmem, 557 busmem->shm_last, &sp, sizeof(sp), &wrap); 558 pktwrote = 0; 559 for (m = m0; m != NULL; m = m->m_next) { 560 pktwrote += m->m_len; 561 dataoff = shmif_buswrite(busmem, dataoff, 562 mtod(m, void *), m->m_len, &wrap); 563 } 564 KASSERT(pktwrote == pktsize); 565 if (wrap) { 566 busmem->shm_gen++; 567 DPRINTF(("bus generation now %" PRIu64 "\n", 568 busmem->shm_gen)); 569 } 570 shmif_unlockbus(busmem); 571 572 m_freem(m0); 573 wrote = true; 574 ifp->if_opackets++; 575 576 DPRINTF(("shmif_start: send %d bytes at off %d\n", 577 pktsize, busmem->shm_last)); 578 } 579 580 ifp->if_flags &= ~IFF_OACTIVE; 581 582 /* wakeup? */ 583 if (wrote) { 584 dowakeup(sc); 585 } 586 } 587 588 static void 589 shmif_stop(struct ifnet *ifp, int disable) 590 { 591 struct shmif_sc *sc = ifp->if_softc; 592 593 ifp->if_flags &= ~IFF_RUNNING; 594 membar_producer(); 595 596 /* 597 * wakeup thread. this will of course wake up all bus 598 * listeners, but that's life. 599 */ 600 if (sc->sc_memfd != -1) { 601 dowakeup(sc); 602 } 603 } 604 605 606 /* 607 * Check if we have been sleeping too long. Basically, 608 * our in-sc nextpkt must by first <= nextpkt <= last"+1". 609 * We use the fact that first is guaranteed to never overlap 610 * with the last frame in the ring. 611 */ 612 static __inline bool 613 stillvalid_p(struct shmif_sc *sc) 614 { 615 struct shmif_mem *busmem = sc->sc_busmem; 616 unsigned gendiff = busmem->shm_gen - sc->sc_devgen; 617 uint32_t lastoff, devoff; 618 619 KASSERT(busmem->shm_first != busmem->shm_last); 620 621 /* normalize onto a 2x busmem chunk */ 622 devoff = sc->sc_nextpacket; 623 lastoff = shmif_nextpktoff(busmem, busmem->shm_last); 624 625 /* trivial case */ 626 if (gendiff > 1) 627 return false; 628 KASSERT(gendiff <= 1); 629 630 /* Normalize onto 2x busmem chunk */ 631 if (busmem->shm_first >= lastoff) { 632 lastoff += BUSMEM_DATASIZE; 633 if (gendiff == 0) 634 devoff += BUSMEM_DATASIZE; 635 } else { 636 if (gendiff) 637 return false; 638 } 639 640 return devoff >= busmem->shm_first && devoff <= lastoff; 641 } 642 643 static void 644 shmif_rcv(void *arg) 645 { 646 struct ifnet *ifp = arg; 647 struct shmif_sc *sc = ifp->if_softc; 648 struct shmif_mem *busmem; 649 struct mbuf *m = NULL; 650 struct ether_header *eth; 651 uint32_t nextpkt; 652 bool wrap, passup; 653 int error; 654 const int align 655 = ALIGN(sizeof(struct ether_header)) - sizeof(struct ether_header); 656 657 reup: 658 mutex_enter(&sc->sc_mtx); 659 while ((ifp->if_flags & IFF_RUNNING) == 0 && !sc->sc_dying) 660 cv_wait(&sc->sc_cv, &sc->sc_mtx); 661 mutex_exit(&sc->sc_mtx); 662 663 busmem = sc->sc_busmem; 664 665 while (ifp->if_flags & IFF_RUNNING) { 666 struct shmif_pkthdr sp; 667 668 if (m == NULL) { 669 m = m_gethdr(M_WAIT, MT_DATA); 670 MCLGET(m, M_WAIT); 671 m->m_data += align; 672 } 673 674 DPRINTF(("waiting %d/%" PRIu64 "\n", 675 sc->sc_nextpacket, sc->sc_devgen)); 676 KASSERT(m->m_flags & M_EXT); 677 678 shmif_lockbus(busmem); 679 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 680 KASSERT(busmem->shm_gen >= sc->sc_devgen); 681 682 /* need more data? */ 683 if (sc->sc_devgen == busmem->shm_gen && 684 shmif_nextpktoff(busmem, busmem->shm_last) 685 == sc->sc_nextpacket) { 686 shmif_unlockbus(busmem); 687 error = 0; 688 rumpcomp_shmif_watchwait(sc->sc_kq); 689 if (__predict_false(error)) 690 printf("shmif_rcv: wait failed %d\n", error); 691 membar_consumer(); 692 continue; 693 } 694 695 if (stillvalid_p(sc)) { 696 nextpkt = sc->sc_nextpacket; 697 } else { 698 KASSERT(busmem->shm_gen > 0); 699 nextpkt = busmem->shm_first; 700 if (busmem->shm_first > busmem->shm_last) 701 sc->sc_devgen = busmem->shm_gen - 1; 702 else 703 sc->sc_devgen = busmem->shm_gen; 704 DPRINTF(("dev %p overrun, new data: %d/%" PRIu64 "\n", 705 sc, nextpkt, sc->sc_devgen)); 706 } 707 708 /* 709 * If our read pointer is ahead the bus last write, our 710 * generation must be one behind. 711 */ 712 KASSERT(!(nextpkt > busmem->shm_last 713 && sc->sc_devgen == busmem->shm_gen)); 714 715 wrap = false; 716 nextpkt = shmif_busread(busmem, &sp, 717 nextpkt, sizeof(sp), &wrap); 718 KASSERT(sp.sp_len <= ETHERMTU + ETHER_HDR_LEN); 719 nextpkt = shmif_busread(busmem, mtod(m, void *), 720 nextpkt, sp.sp_len, &wrap); 721 722 DPRINTF(("shmif_rcv: read packet of length %d at %d\n", 723 sp.sp_len, nextpkt)); 724 725 sc->sc_nextpacket = nextpkt; 726 shmif_unlockbus(sc->sc_busmem); 727 728 if (wrap) { 729 sc->sc_devgen++; 730 DPRINTF(("dev %p generation now %" PRIu64 "\n", 731 sc, sc->sc_devgen)); 732 } 733 734 /* 735 * Ignore packets too short to possibly be valid. 736 * This is hit at least for the first frame on a new bus. 737 */ 738 if (__predict_false(sp.sp_len < ETHER_HDR_LEN)) { 739 DPRINTF(("shmif read packet len %d < ETHER_HDR_LEN\n", 740 sp.sp_len)); 741 continue; 742 } 743 744 m->m_len = m->m_pkthdr.len = sp.sp_len; 745 m->m_pkthdr.rcvif = ifp; 746 747 /* 748 * Test if we want to pass the packet upwards 749 */ 750 eth = mtod(m, struct ether_header *); 751 if (sp.sp_sender == sc->sc_uuid) { 752 passup = false; 753 } else if (memcmp(eth->ether_dhost, CLLADDR(ifp->if_sadl), 754 ETHER_ADDR_LEN) == 0) { 755 passup = true; 756 } else if (ETHER_IS_MULTICAST(eth->ether_dhost)) { 757 passup = true; 758 } else if (ifp->if_flags & IFF_PROMISC) { 759 m->m_flags |= M_PROMISC; 760 passup = true; 761 } else { 762 passup = false; 763 } 764 765 if (passup) { 766 ifp->if_ipackets++; 767 KERNEL_LOCK(1, NULL); 768 bpf_mtap(ifp, m); 769 ifp->if_input(ifp, m); 770 KERNEL_UNLOCK_ONE(NULL); 771 m = NULL; 772 } 773 /* else: reuse mbuf for a future packet */ 774 } 775 m_freem(m); 776 m = NULL; 777 778 if (!sc->sc_dying) 779 goto reup; 780 781 kthread_exit(0); 782 } 783