if_shmem.c revision 1.67
1 /* $NetBSD: if_shmem.c,v 1.67 2016/06/10 13:27:16 ozaki-r 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 1.67 2016/06/10 13:27:16 ozaki-r 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_initialize(ifp); 191 ether_ifattach(ifp, enaddr); 192 if_register(ifp); 193 194 aprint_verbose("shmif%d: Ethernet address %s\n", 195 unit, ether_sprintf(enaddr)); 196 197 if (scp) 198 *scp = sc; 199 200 error = 0; 201 if (rump_threads) { 202 error = kthread_create(PRI_NONE, 203 KTHREAD_MPSAFE | KTHREAD_MUSTJOIN, NULL, 204 shmif_rcv, ifp, &sc->sc_rcvl, "shmif"); 205 } else { 206 printf("WARNING: threads not enabled, shmif NOT working\n"); 207 } 208 209 if (error) { 210 shmif_unclone(ifp); 211 } 212 213 return error; 214 } 215 216 static int 217 initbackend(struct shmif_sc *sc, int memfd) 218 { 219 volatile uint8_t v; 220 volatile uint8_t *p; 221 void *mem; 222 int error; 223 224 error = rumpcomp_shmif_mmap(memfd, BUSMEM_SIZE, &mem); 225 if (error) 226 return error; 227 sc->sc_busmem = mem; 228 229 if (sc->sc_busmem->shm_magic 230 && sc->sc_busmem->shm_magic != SHMIF_MAGIC) { 231 printf("bus is not magical"); 232 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 233 return ENOEXEC; 234 } 235 236 /* 237 * Prefault in pages to minimize runtime penalty with buslock. 238 * Use 512 instead of PAGE_SIZE to make sure we catch cases where 239 * rump kernel PAGE_SIZE > host page size. 240 */ 241 for (p = (uint8_t *)sc->sc_busmem; 242 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 243 p += 512) 244 v = *p; 245 246 shmif_lockbus(sc->sc_busmem); 247 /* we're first? initialize bus */ 248 if (sc->sc_busmem->shm_magic == 0) { 249 sc->sc_busmem->shm_magic = SHMIF_MAGIC; 250 sc->sc_busmem->shm_first = BUSMEM_DATASIZE; 251 } 252 253 sc->sc_nextpacket = sc->sc_busmem->shm_last; 254 sc->sc_devgen = sc->sc_busmem->shm_gen; 255 256 #ifdef PREFAULT_RW 257 for (p = (uint8_t *)sc->sc_busmem; 258 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 259 p += PAGE_SIZE) { 260 v = *p; 261 *p = v; 262 } 263 #endif 264 shmif_unlockbus(sc->sc_busmem); 265 266 sc->sc_kq = -1; 267 error = rumpcomp_shmif_watchsetup(&sc->sc_kq, memfd); 268 if (error) { 269 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 270 return error; 271 } 272 273 sc->sc_memfd = memfd; 274 275 return error; 276 } 277 278 static void 279 finibackend(struct shmif_sc *sc) 280 { 281 282 if (sc->sc_backfile == NULL) 283 return; 284 285 if (sc->sc_backfile) { 286 kmem_free(sc->sc_backfile, sc->sc_backfilelen); 287 sc->sc_backfile = NULL; 288 sc->sc_backfilelen = 0; 289 } 290 291 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 292 rumpuser_close(sc->sc_memfd); 293 rumpuser_close(sc->sc_kq); 294 295 sc->sc_memfd = -1; 296 } 297 298 int 299 rump_shmif_create(const char *path, int *ifnum) 300 { 301 struct shmif_sc *sc; 302 vmem_addr_t t; 303 int unit, error; 304 int memfd = -1; /* XXXgcc */ 305 306 if (path) { 307 error = rumpuser_open(path, 308 RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd); 309 if (error) 310 return error; 311 } 312 313 error = vmem_xalloc(shmif_units, 1, 0, 0, 0, 314 VMEM_ADDR_MIN, VMEM_ADDR_MAX, VM_INSTANTFIT | VM_SLEEP, &t); 315 316 if (error != 0) { 317 if (path) 318 rumpuser_close(memfd); 319 return error; 320 } 321 322 unit = t - 1; 323 324 if ((error = allocif(unit, &sc)) != 0) { 325 if (path) 326 rumpuser_close(memfd); 327 return error; 328 } 329 330 if (!path) 331 goto out; 332 333 error = initbackend(sc, memfd); 334 if (error) { 335 shmif_unclone(&sc->sc_ec.ec_if); 336 return error; 337 } 338 339 sc->sc_backfilelen = strlen(path)+1; 340 sc->sc_backfile = kmem_alloc(sc->sc_backfilelen, KM_SLEEP); 341 strcpy(sc->sc_backfile, path); 342 343 out: 344 if (ifnum) 345 *ifnum = unit; 346 347 return 0; 348 } 349 350 static int 351 shmif_clone(struct if_clone *ifc, int unit) 352 { 353 int rc __diagused; 354 vmem_addr_t unit2; 355 356 /* 357 * Ok, we know the unit number, but we must still reserve it. 358 * Otherwise the wildcard-side of things might get the same one. 359 * This is slightly offset-happy due to vmem. First, we offset 360 * the range of unit numbers by +1 since vmem cannot deal with 361 * ranges starting from 0. Talk about uuuh. 362 */ 363 rc = vmem_xalloc(shmif_units, 1, 0, 0, 0, unit+1, unit+1, 364 VM_SLEEP | VM_INSTANTFIT, &unit2); 365 KASSERT(rc == 0 && unit2-1 == unit); 366 367 return allocif(unit, NULL); 368 } 369 370 static int 371 shmif_unclone(struct ifnet *ifp) 372 { 373 struct shmif_sc *sc = ifp->if_softc; 374 375 shmif_stop(ifp, 1); 376 if_down(ifp); 377 finibackend(sc); 378 379 mutex_enter(&sc->sc_mtx); 380 sc->sc_dying = true; 381 cv_broadcast(&sc->sc_cv); 382 mutex_exit(&sc->sc_mtx); 383 384 if (sc->sc_rcvl) 385 kthread_join(sc->sc_rcvl); 386 sc->sc_rcvl = NULL; 387 388 vmem_xfree(shmif_units, sc->sc_unit+1, 1); 389 390 ether_ifdetach(ifp); 391 if_detach(ifp); 392 393 cv_destroy(&sc->sc_cv); 394 mutex_destroy(&sc->sc_mtx); 395 396 kmem_free(sc, sizeof(*sc)); 397 398 return 0; 399 } 400 401 static int 402 shmif_init(struct ifnet *ifp) 403 { 404 struct shmif_sc *sc = ifp->if_softc; 405 int error = 0; 406 407 if (sc->sc_memfd == -1) 408 return ENXIO; 409 KASSERT(sc->sc_busmem); 410 411 ifp->if_flags |= IFF_RUNNING; 412 413 mutex_enter(&sc->sc_mtx); 414 sc->sc_nextpacket = sc->sc_busmem->shm_last; 415 sc->sc_devgen = sc->sc_busmem->shm_gen; 416 417 cv_broadcast(&sc->sc_cv); 418 mutex_exit(&sc->sc_mtx); 419 420 return error; 421 } 422 423 static int 424 shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 425 { 426 struct shmif_sc *sc = ifp->if_softc; 427 struct ifdrv *ifd; 428 char *path; 429 int s, rv, memfd; 430 431 s = splnet(); 432 switch (cmd) { 433 case SIOCGLINKSTR: 434 ifd = data; 435 436 if (sc->sc_backfilelen == 0) { 437 rv = ENOENT; 438 break; 439 } 440 441 ifd->ifd_len = sc->sc_backfilelen; 442 if (ifd->ifd_cmd == IFLINKSTR_QUERYLEN) { 443 rv = 0; 444 break; 445 } 446 447 if (ifd->ifd_cmd != 0) { 448 rv = EINVAL; 449 break; 450 } 451 452 rv = copyoutstr(sc->sc_backfile, ifd->ifd_data, 453 MIN(sc->sc_backfilelen, ifd->ifd_len), NULL); 454 break; 455 case SIOCSLINKSTR: 456 if (ifp->if_flags & IFF_UP) { 457 rv = EBUSY; 458 break; 459 } 460 461 ifd = data; 462 if (ifd->ifd_cmd == IFLINKSTR_UNSET) { 463 finibackend(sc); 464 rv = 0; 465 break; 466 } else if (ifd->ifd_cmd != 0) { 467 rv = EINVAL; 468 break; 469 } else if (sc->sc_backfile) { 470 rv = EBUSY; 471 break; 472 } 473 474 if (ifd->ifd_len > MAXPATHLEN) { 475 rv = E2BIG; 476 break; 477 } else if (ifd->ifd_len < 1) { 478 rv = EINVAL; 479 break; 480 } 481 482 path = kmem_alloc(ifd->ifd_len, KM_SLEEP); 483 rv = copyinstr(ifd->ifd_data, path, ifd->ifd_len, NULL); 484 if (rv) { 485 kmem_free(path, ifd->ifd_len); 486 break; 487 } 488 rv = rumpuser_open(path, 489 RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd); 490 if (rv) { 491 kmem_free(path, ifd->ifd_len); 492 break; 493 } 494 rv = initbackend(sc, memfd); 495 if (rv) { 496 kmem_free(path, ifd->ifd_len); 497 rumpuser_close(memfd); 498 break; 499 } 500 sc->sc_backfile = path; 501 sc->sc_backfilelen = ifd->ifd_len; 502 503 break; 504 default: 505 rv = ether_ioctl(ifp, cmd, data); 506 if (rv == ENETRESET) 507 rv = 0; 508 break; 509 } 510 splx(s); 511 512 return rv; 513 } 514 515 /* send everything in-context since it's just a matter of mem-to-mem copy */ 516 static void 517 shmif_start(struct ifnet *ifp) 518 { 519 struct shmif_sc *sc = ifp->if_softc; 520 struct shmif_mem *busmem = sc->sc_busmem; 521 struct mbuf *m, *m0; 522 uint32_t dataoff; 523 uint32_t pktsize, pktwrote; 524 bool wrote = false; 525 bool wrap; 526 527 ifp->if_flags |= IFF_OACTIVE; 528 529 for (;;) { 530 struct shmif_pkthdr sp; 531 struct timeval tv; 532 533 IF_DEQUEUE(&ifp->if_snd, m0); 534 if (m0 == NULL) { 535 break; 536 } 537 538 pktsize = 0; 539 for (m = m0; m != NULL; m = m->m_next) { 540 pktsize += m->m_len; 541 } 542 KASSERT(pktsize <= ETHERMTU + ETHER_HDR_LEN); 543 544 getmicrouptime(&tv); 545 sp.sp_len = pktsize; 546 sp.sp_sec = tv.tv_sec; 547 sp.sp_usec = tv.tv_usec; 548 sp.sp_sender = sc->sc_uuid; 549 550 bpf_mtap(ifp, m0); 551 552 shmif_lockbus(busmem); 553 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 554 busmem->shm_last = shmif_nextpktoff(busmem, busmem->shm_last); 555 556 wrap = false; 557 dataoff = shmif_buswrite(busmem, 558 busmem->shm_last, &sp, sizeof(sp), &wrap); 559 pktwrote = 0; 560 for (m = m0; m != NULL; m = m->m_next) { 561 pktwrote += m->m_len; 562 dataoff = shmif_buswrite(busmem, dataoff, 563 mtod(m, void *), m->m_len, &wrap); 564 } 565 KASSERT(pktwrote == pktsize); 566 if (wrap) { 567 busmem->shm_gen++; 568 DPRINTF(("bus generation now %" PRIu64 "\n", 569 busmem->shm_gen)); 570 } 571 shmif_unlockbus(busmem); 572 573 m_freem(m0); 574 wrote = true; 575 ifp->if_opackets++; 576 577 DPRINTF(("shmif_start: send %d bytes at off %d\n", 578 pktsize, busmem->shm_last)); 579 } 580 581 ifp->if_flags &= ~IFF_OACTIVE; 582 583 /* wakeup? */ 584 if (wrote) { 585 dowakeup(sc); 586 } 587 } 588 589 static void 590 shmif_stop(struct ifnet *ifp, int disable) 591 { 592 struct shmif_sc *sc = ifp->if_softc; 593 594 ifp->if_flags &= ~IFF_RUNNING; 595 membar_producer(); 596 597 /* 598 * wakeup thread. this will of course wake up all bus 599 * listeners, but that's life. 600 */ 601 if (sc->sc_memfd != -1) { 602 dowakeup(sc); 603 } 604 } 605 606 607 /* 608 * Check if we have been sleeping too long. Basically, 609 * our in-sc nextpkt must by first <= nextpkt <= last"+1". 610 * We use the fact that first is guaranteed to never overlap 611 * with the last frame in the ring. 612 */ 613 static __inline bool 614 stillvalid_p(struct shmif_sc *sc) 615 { 616 struct shmif_mem *busmem = sc->sc_busmem; 617 unsigned gendiff = busmem->shm_gen - sc->sc_devgen; 618 uint32_t lastoff, devoff; 619 620 KASSERT(busmem->shm_first != busmem->shm_last); 621 622 /* normalize onto a 2x busmem chunk */ 623 devoff = sc->sc_nextpacket; 624 lastoff = shmif_nextpktoff(busmem, busmem->shm_last); 625 626 /* trivial case */ 627 if (gendiff > 1) 628 return false; 629 KASSERT(gendiff <= 1); 630 631 /* Normalize onto 2x busmem chunk */ 632 if (busmem->shm_first >= lastoff) { 633 lastoff += BUSMEM_DATASIZE; 634 if (gendiff == 0) 635 devoff += BUSMEM_DATASIZE; 636 } else { 637 if (gendiff) 638 return false; 639 } 640 641 return devoff >= busmem->shm_first && devoff <= lastoff; 642 } 643 644 static void 645 shmif_rcv(void *arg) 646 { 647 struct ifnet *ifp = arg; 648 struct shmif_sc *sc = ifp->if_softc; 649 struct shmif_mem *busmem; 650 struct mbuf *m = NULL; 651 struct ether_header *eth; 652 uint32_t nextpkt; 653 bool wrap, passup; 654 int error; 655 const int align 656 = ALIGN(sizeof(struct ether_header)) - sizeof(struct ether_header); 657 658 reup: 659 mutex_enter(&sc->sc_mtx); 660 while ((ifp->if_flags & IFF_RUNNING) == 0 && !sc->sc_dying) 661 cv_wait(&sc->sc_cv, &sc->sc_mtx); 662 mutex_exit(&sc->sc_mtx); 663 664 busmem = sc->sc_busmem; 665 666 while (ifp->if_flags & IFF_RUNNING) { 667 struct shmif_pkthdr sp; 668 669 if (m == NULL) { 670 m = m_gethdr(M_WAIT, MT_DATA); 671 MCLGET(m, M_WAIT); 672 m->m_data += align; 673 } 674 675 DPRINTF(("waiting %d/%" PRIu64 "\n", 676 sc->sc_nextpacket, sc->sc_devgen)); 677 KASSERT(m->m_flags & M_EXT); 678 679 shmif_lockbus(busmem); 680 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 681 KASSERT(busmem->shm_gen >= sc->sc_devgen); 682 683 /* need more data? */ 684 if (sc->sc_devgen == busmem->shm_gen && 685 shmif_nextpktoff(busmem, busmem->shm_last) 686 == sc->sc_nextpacket) { 687 shmif_unlockbus(busmem); 688 error = 0; 689 rumpcomp_shmif_watchwait(sc->sc_kq); 690 if (__predict_false(error)) 691 printf("shmif_rcv: wait failed %d\n", error); 692 membar_consumer(); 693 continue; 694 } 695 696 if (stillvalid_p(sc)) { 697 nextpkt = sc->sc_nextpacket; 698 } else { 699 KASSERT(busmem->shm_gen > 0); 700 nextpkt = busmem->shm_first; 701 if (busmem->shm_first > busmem->shm_last) 702 sc->sc_devgen = busmem->shm_gen - 1; 703 else 704 sc->sc_devgen = busmem->shm_gen; 705 DPRINTF(("dev %p overrun, new data: %d/%" PRIu64 "\n", 706 sc, nextpkt, sc->sc_devgen)); 707 } 708 709 /* 710 * If our read pointer is ahead the bus last write, our 711 * generation must be one behind. 712 */ 713 KASSERT(!(nextpkt > busmem->shm_last 714 && sc->sc_devgen == busmem->shm_gen)); 715 716 wrap = false; 717 nextpkt = shmif_busread(busmem, &sp, 718 nextpkt, sizeof(sp), &wrap); 719 KASSERT(sp.sp_len <= ETHERMTU + ETHER_HDR_LEN); 720 nextpkt = shmif_busread(busmem, mtod(m, void *), 721 nextpkt, sp.sp_len, &wrap); 722 723 DPRINTF(("shmif_rcv: read packet of length %d at %d\n", 724 sp.sp_len, nextpkt)); 725 726 sc->sc_nextpacket = nextpkt; 727 shmif_unlockbus(sc->sc_busmem); 728 729 if (wrap) { 730 sc->sc_devgen++; 731 DPRINTF(("dev %p generation now %" PRIu64 "\n", 732 sc, sc->sc_devgen)); 733 } 734 735 /* 736 * Ignore packets too short to possibly be valid. 737 * This is hit at least for the first frame on a new bus. 738 */ 739 if (__predict_false(sp.sp_len < ETHER_HDR_LEN)) { 740 DPRINTF(("shmif read packet len %d < ETHER_HDR_LEN\n", 741 sp.sp_len)); 742 continue; 743 } 744 745 m->m_len = m->m_pkthdr.len = sp.sp_len; 746 m_set_rcvif(m, ifp); 747 748 /* 749 * Test if we want to pass the packet upwards 750 */ 751 eth = mtod(m, struct ether_header *); 752 if (sp.sp_sender == sc->sc_uuid) { 753 passup = false; 754 } else if (memcmp(eth->ether_dhost, CLLADDR(ifp->if_sadl), 755 ETHER_ADDR_LEN) == 0) { 756 passup = true; 757 } else if (ETHER_IS_MULTICAST(eth->ether_dhost)) { 758 passup = true; 759 } else if (ifp->if_flags & IFF_PROMISC) { 760 m->m_flags |= M_PROMISC; 761 passup = true; 762 } else { 763 passup = false; 764 } 765 766 if (passup) { 767 int bound = curlwp->l_pflag & LP_BOUND; 768 ifp->if_ipackets++; 769 KERNEL_LOCK(1, NULL); 770 /* Prevent LWP migrations between CPUs for psref(9) */ 771 curlwp->l_pflag |= LP_BOUND; 772 bpf_mtap(ifp, m); 773 if_input(ifp, m); 774 curlwp->l_pflag ^= bound ^ LP_BOUND; 775 KERNEL_UNLOCK_ONE(NULL); 776 m = NULL; 777 } 778 /* else: reuse mbuf for a future packet */ 779 } 780 m_freem(m); 781 m = NULL; 782 783 if (!sc->sc_dying) 784 goto reup; 785 786 kthread_exit(0); 787 } 788
Indexes created Mon Sep 22 13:09:51 GMT 2025