if_shmem.c revision 1.82
1 /* $NetBSD: if_shmem.c,v 1.82 2021/06/16 00:21:19 riastradh 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 1.82 2021/06/16 00:21:19 riastradh 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 #include <net/ether_sw_offload.h> 47 48 #include <netinet/in.h> 49 #include <netinet/in_var.h> 50 51 #include <rump-sys/kern.h> 52 #include <rump-sys/net.h> 53 54 #include <rump/rump.h> 55 #include <rump/rumpuser.h> 56 57 #include "shmif_user.h" 58 59 static int shmif_clone(struct if_clone *, int); 60 static int shmif_unclone(struct ifnet *); 61 62 struct if_clone shmif_cloner = 63 IF_CLONE_INITIALIZER("shmif", shmif_clone, shmif_unclone); 64 65 /* 66 * Do r/w prefault for backend pages when attaching the interface. 67 * At least logically thinking improves performance (although no 68 * mlocking is done, so they might go away). 69 */ 70 #define PREFAULT_RW 71 72 /* 73 * A virtual ethernet interface which uses shared memory from a 74 * memory mapped file as the bus. 75 */ 76 77 static int shmif_init(struct ifnet *); 78 static int shmif_ioctl(struct ifnet *, u_long, void *); 79 static void shmif_start(struct ifnet *); 80 static void shmif_snd(struct ifnet *, struct mbuf *); 81 static void shmif_stop(struct ifnet *, int); 82 83 #include "shmifvar.h" 84 85 struct shmif_sc { 86 struct ethercom sc_ec; 87 struct shmif_mem *sc_busmem; 88 int sc_memfd; 89 int sc_kq; 90 int sc_unit; 91 92 char *sc_backfile; 93 size_t sc_backfilelen; 94 95 uint64_t sc_devgen; 96 uint32_t sc_nextpacket; 97 98 kmutex_t sc_mtx; 99 kcondvar_t sc_cv; 100 101 struct lwp *sc_rcvl; 102 bool sc_dying; 103 104 uint64_t sc_uid; 105 }; 106 107 static void shmif_rcv(void *); 108 109 #define LOCK_UNLOCKED 0 110 #define LOCK_LOCKED 1 111 #define LOCK_COOLDOWN 1001 112 113 vmem_t *shmif_units; 114 115 static void 116 dowakeup(struct shmif_sc *sc) 117 { 118 struct rumpuser_iovec iov; 119 uint32_t ver = SHMIF_VERSION; 120 size_t n; 121 122 iov.iov_base = &ver; 123 iov.iov_len = sizeof(ver); 124 rumpuser_iovwrite(sc->sc_memfd, &iov, 1, IFMEM_WAKEUP, &n); 125 } 126 127 /* 128 * This locking needs work and will misbehave severely if: 129 * 1) the backing memory has to be paged in 130 * 2) some lockholder exits while holding the lock 131 */ 132 static void 133 shmif_lockbus(struct shmif_mem *busmem) 134 { 135 int i = 0; 136 137 while (__predict_false(atomic_cas_32(&busmem->shm_lock, 138 LOCK_UNLOCKED, LOCK_LOCKED) == LOCK_LOCKED)) { 139 if (__predict_false(++i > LOCK_COOLDOWN)) { 140 /* wait 1ms */ 141 rumpuser_clock_sleep(RUMPUSER_CLOCK_RELWALL, 142 0, 1000*1000); 143 i = 0; 144 } 145 continue; 146 } 147 membar_enter(); 148 } 149 150 static void 151 shmif_unlockbus(struct shmif_mem *busmem) 152 { 153 unsigned int old __diagused; 154 155 membar_exit(); 156 old = atomic_swap_32(&busmem->shm_lock, LOCK_UNLOCKED); 157 KASSERT(old == LOCK_LOCKED); 158 } 159 160 static int 161 allocif(int unit, struct shmif_sc **scp) 162 { 163 uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0xa0, 0x00, 0x00, 0x00, 0x00 }; 164 struct shmif_sc *sc; 165 struct ifnet *ifp; 166 uint64_t randnum; 167 int error = 0; 168 169 randnum = cprng_strong64(); 170 memcpy(&enaddr[2], &randnum, 4); 171 172 sc = kmem_zalloc(sizeof(*sc), KM_SLEEP); 173 sc->sc_memfd = -1; 174 sc->sc_unit = unit; 175 sc->sc_uid = randnum; 176 177 ifp = &sc->sc_ec.ec_if; 178 179 snprintf(ifp->if_xname, sizeof(ifp->if_xname), "shmif%d", unit); 180 ifp->if_softc = sc; 181 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 182 ifp->if_init = shmif_init; 183 ifp->if_ioctl = shmif_ioctl; 184 ifp->if_start = shmif_start; 185 ifp->if_stop = shmif_stop; 186 ifp->if_mtu = ETHERMTU; 187 ifp->if_dlt = DLT_EN10MB; 188 ifp->if_capabilities = IFCAP_TSOv4 | IFCAP_TSOv6 | 189 IFCAP_CSUM_IPv4_Rx | IFCAP_CSUM_IPv4_Tx | 190 IFCAP_CSUM_TCPv4_Rx | IFCAP_CSUM_TCPv4_Tx | 191 IFCAP_CSUM_UDPv4_Rx | IFCAP_CSUM_UDPv4_Tx | 192 IFCAP_CSUM_TCPv6_Rx | IFCAP_CSUM_TCPv6_Tx | 193 IFCAP_CSUM_UDPv6_Rx | IFCAP_CSUM_UDPv6_Tx; 194 195 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE); 196 cv_init(&sc->sc_cv, "shmifcv"); 197 198 if_initialize(ifp); 199 #if 1 200 char buf[256]; 201 202 if (rumpuser_getparam("RUMP_SHMIF_CAPENABLE", buf, sizeof(buf)) == 0) { 203 uint64_t capen = strtoul(buf, NULL, 0); 204 205 ifp->if_capenable = capen & ifp->if_capabilities; 206 } 207 #endif 208 209 ether_ifattach(ifp, enaddr); 210 if_register(ifp); 211 212 aprint_verbose("shmif%d: Ethernet address %s\n", 213 unit, ether_sprintf(enaddr)); 214 215 if (scp) 216 *scp = sc; 217 218 if (rump_threads) { 219 error = kthread_create(PRI_NONE, 220 KTHREAD_MPSAFE | KTHREAD_MUSTJOIN, NULL, 221 shmif_rcv, ifp, &sc->sc_rcvl, "shmif"); 222 } else { 223 printf("WARNING: threads not enabled, shmif NOT working\n"); 224 } 225 226 if (error) { 227 shmif_unclone(ifp); 228 } 229 230 return 0; 231 } 232 233 static int 234 initbackend(struct shmif_sc *sc, int memfd) 235 { 236 volatile uint8_t v; 237 volatile uint8_t *p; 238 void *mem; 239 int error; 240 241 error = rumpcomp_shmif_mmap(memfd, BUSMEM_SIZE, &mem); 242 if (error) 243 return error; 244 sc->sc_busmem = mem; 245 246 if (sc->sc_busmem->shm_magic 247 && sc->sc_busmem->shm_magic != SHMIF_MAGIC) { 248 printf("bus is not magical"); 249 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 250 return ENOEXEC; 251 } 252 253 /* 254 * Prefault in pages to minimize runtime penalty with buslock. 255 * Use 512 instead of PAGE_SIZE to make sure we catch cases where 256 * rump kernel PAGE_SIZE > host page size. 257 */ 258 for (p = (uint8_t *)sc->sc_busmem; 259 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 260 p += 512) 261 v = *p; 262 263 shmif_lockbus(sc->sc_busmem); 264 /* we're first? initialize bus */ 265 if (sc->sc_busmem->shm_magic == 0) { 266 sc->sc_busmem->shm_magic = SHMIF_MAGIC; 267 sc->sc_busmem->shm_first = BUSMEM_DATASIZE; 268 } 269 270 sc->sc_nextpacket = sc->sc_busmem->shm_last; 271 sc->sc_devgen = sc->sc_busmem->shm_gen; 272 273 #ifdef PREFAULT_RW 274 for (p = (uint8_t *)sc->sc_busmem; 275 p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE; 276 p += PAGE_SIZE) { 277 v = *p; 278 *p = v; 279 } 280 #endif 281 shmif_unlockbus(sc->sc_busmem); 282 283 sc->sc_kq = -1; 284 error = rumpcomp_shmif_watchsetup(&sc->sc_kq, memfd); 285 if (error) { 286 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 287 return error; 288 } 289 290 sc->sc_memfd = memfd; 291 292 return error; 293 } 294 295 static void 296 finibackend(struct shmif_sc *sc) 297 { 298 299 if (sc->sc_backfile == NULL) 300 return; 301 302 if (sc->sc_backfile) { 303 kmem_free(sc->sc_backfile, sc->sc_backfilelen); 304 sc->sc_backfile = NULL; 305 sc->sc_backfilelen = 0; 306 } 307 308 rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE); 309 rumpuser_close(sc->sc_memfd); 310 rumpuser_close(sc->sc_kq); 311 312 sc->sc_memfd = -1; 313 } 314 315 int 316 rump_shmif_create(const char *path, int *ifnum) 317 { 318 struct shmif_sc *sc; 319 vmem_addr_t t; 320 int unit, error; 321 int memfd = -1; /* XXXgcc */ 322 323 if (path) { 324 error = rumpuser_open(path, 325 RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd); 326 if (error) 327 return error; 328 } 329 330 error = vmem_xalloc(shmif_units, 1, 0, 0, 0, 331 VMEM_ADDR_MIN, VMEM_ADDR_MAX, VM_INSTANTFIT | VM_SLEEP, &t); 332 333 if (error != 0) { 334 if (path) 335 rumpuser_close(memfd); 336 return error; 337 } 338 339 unit = t - 1; 340 341 if ((error = allocif(unit, &sc)) != 0) { 342 if (path) 343 rumpuser_close(memfd); 344 return error; 345 } 346 347 if (!path) 348 goto out; 349 350 error = initbackend(sc, memfd); 351 if (error) { 352 shmif_unclone(&sc->sc_ec.ec_if); 353 return error; 354 } 355 356 sc->sc_backfilelen = strlen(path)+1; 357 sc->sc_backfile = kmem_alloc(sc->sc_backfilelen, KM_SLEEP); 358 strcpy(sc->sc_backfile, path); 359 360 out: 361 if (ifnum) 362 *ifnum = unit; 363 364 return 0; 365 } 366 367 static int 368 shmif_clone(struct if_clone *ifc, int unit) 369 { 370 int rc __diagused; 371 vmem_addr_t unit2; 372 373 /* 374 * Ok, we know the unit number, but we must still reserve it. 375 * Otherwise the wildcard-side of things might get the same one. 376 * This is slightly offset-happy due to vmem. First, we offset 377 * the range of unit numbers by +1 since vmem cannot deal with 378 * ranges starting from 0. Talk about uuuh. 379 */ 380 rc = vmem_xalloc(shmif_units, 1, 0, 0, 0, unit+1, unit+1, 381 VM_SLEEP | VM_INSTANTFIT, &unit2); 382 KASSERT(rc == 0 && unit2-1 == unit); 383 384 return allocif(unit, NULL); 385 } 386 387 static int 388 shmif_unclone(struct ifnet *ifp) 389 { 390 struct shmif_sc *sc = ifp->if_softc; 391 392 shmif_stop(ifp, 1); 393 if_down(ifp); 394 395 mutex_enter(&sc->sc_mtx); 396 sc->sc_dying = true; 397 cv_broadcast(&sc->sc_cv); 398 mutex_exit(&sc->sc_mtx); 399 400 if (sc->sc_rcvl) 401 kthread_join(sc->sc_rcvl); 402 sc->sc_rcvl = NULL; 403 404 /* 405 * Need to be called after the kthread left, otherwise closing kqueue 406 * (sc_kq) hangs sometimes perhaps because of a race condition between 407 * close and kevent in the kthread on the kqueue. 408 */ 409 finibackend(sc); 410 411 vmem_xfree(shmif_units, sc->sc_unit+1, 1); 412 413 ether_ifdetach(ifp); 414 if_detach(ifp); 415 416 cv_destroy(&sc->sc_cv); 417 mutex_destroy(&sc->sc_mtx); 418 419 kmem_free(sc, sizeof(*sc)); 420 421 return 0; 422 } 423 424 static int 425 shmif_init(struct ifnet *ifp) 426 { 427 struct shmif_sc *sc = ifp->if_softc; 428 int error = 0; 429 430 if (sc->sc_memfd == -1) 431 return ENXIO; 432 KASSERT(sc->sc_busmem); 433 434 ifp->if_flags |= IFF_RUNNING; 435 436 mutex_enter(&sc->sc_mtx); 437 sc->sc_nextpacket = sc->sc_busmem->shm_last; 438 sc->sc_devgen = sc->sc_busmem->shm_gen; 439 440 cv_broadcast(&sc->sc_cv); 441 mutex_exit(&sc->sc_mtx); 442 443 return error; 444 } 445 446 static int 447 shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 448 { 449 struct shmif_sc *sc = ifp->if_softc; 450 struct ifdrv *ifd; 451 char *path; 452 int s, rv, memfd; 453 454 s = splnet(); 455 switch (cmd) { 456 case SIOCGLINKSTR: 457 ifd = data; 458 459 if (sc->sc_backfilelen == 0) { 460 rv = ENOENT; 461 break; 462 } 463 464 ifd->ifd_len = sc->sc_backfilelen; 465 if (ifd->ifd_cmd == IFLINKSTR_QUERYLEN) { 466 rv = 0; 467 break; 468 } 469 470 if (ifd->ifd_cmd != 0) { 471 rv = EINVAL; 472 break; 473 } 474 475 rv = copyoutstr(sc->sc_backfile, ifd->ifd_data, 476 MIN(sc->sc_backfilelen, ifd->ifd_len), NULL); 477 break; 478 case SIOCSLINKSTR: 479 if (ifp->if_flags & IFF_UP) { 480 rv = EBUSY; 481 break; 482 } 483 484 ifd = data; 485 if (ifd->ifd_cmd == IFLINKSTR_UNSET) { 486 finibackend(sc); 487 rv = 0; 488 break; 489 } else if (ifd->ifd_cmd != 0) { 490 rv = EINVAL; 491 break; 492 } else if (sc->sc_backfile) { 493 rv = EBUSY; 494 break; 495 } 496 497 if (ifd->ifd_len > MAXPATHLEN) { 498 rv = E2BIG; 499 break; 500 } else if (ifd->ifd_len < 1) { 501 rv = EINVAL; 502 break; 503 } 504 505 path = kmem_alloc(ifd->ifd_len, KM_SLEEP); 506 rv = copyinstr(ifd->ifd_data, path, ifd->ifd_len, NULL); 507 if (rv) { 508 kmem_free(path, ifd->ifd_len); 509 break; 510 } 511 rv = rumpuser_open(path, 512 RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd); 513 if (rv) { 514 kmem_free(path, ifd->ifd_len); 515 break; 516 } 517 rv = initbackend(sc, memfd); 518 if (rv) { 519 kmem_free(path, ifd->ifd_len); 520 rumpuser_close(memfd); 521 break; 522 } 523 sc->sc_backfile = path; 524 sc->sc_backfilelen = ifd->ifd_len; 525 526 break; 527 default: 528 rv = ether_ioctl(ifp, cmd, data); 529 if (rv == ENETRESET) 530 rv = 0; 531 break; 532 } 533 splx(s); 534 535 return rv; 536 } 537 538 static void 539 shmif_start(struct ifnet *ifp) 540 { 541 struct shmif_sc *sc = ifp->if_softc; 542 struct mbuf *m, *n; 543 bool wrote = false; 544 545 ifp->if_flags |= IFF_OACTIVE; 546 547 for (;;) { 548 IF_DEQUEUE(&ifp->if_snd, m); 549 if (m == NULL) 550 break; 551 552 m = ether_sw_offload_tx(ifp, m); 553 if (m == NULL) { 554 if_statinc(ifp, if_oerrors); 555 break; 556 } 557 558 do { 559 n = m->m_nextpkt; 560 shmif_snd(ifp, m); 561 m = n; 562 } while (m != NULL); 563 564 wrote = true; 565 } 566 567 ifp->if_flags &= ~IFF_OACTIVE; 568 569 /* wakeup? */ 570 if (wrote) { 571 dowakeup(sc); 572 } 573 } 574 575 /* send everything in-context since it's just a matter of mem-to-mem copy */ 576 static void 577 shmif_snd(struct ifnet *ifp, struct mbuf *m0) 578 { 579 struct shmif_sc *sc = ifp->if_softc; 580 struct shmif_mem *busmem = sc->sc_busmem; 581 struct shmif_pkthdr sp; 582 struct timeval tv; 583 struct mbuf *m; 584 uint32_t dataoff; 585 uint32_t pktsize, pktwrote; 586 bool wrap; 587 588 pktsize = 0; 589 for (m = m0; m != NULL; m = m->m_next) { 590 pktsize += m->m_len; 591 } 592 KASSERT(pktsize <= ETHERMTU + ETHER_HDR_LEN); 593 594 getmicrouptime(&tv); 595 sp.sp_len = pktsize; 596 sp.sp_sec = tv.tv_sec; 597 sp.sp_usec = tv.tv_usec; 598 sp.sp_sender = sc->sc_uid; 599 600 bpf_mtap(ifp, m0, BPF_D_OUT); 601 602 shmif_lockbus(busmem); 603 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 604 busmem->shm_last = shmif_nextpktoff(busmem, busmem->shm_last); 605 606 wrap = false; 607 dataoff = 608 shmif_buswrite(busmem, busmem->shm_last, &sp, sizeof(sp), &wrap); 609 pktwrote = 0; 610 for (m = m0; m != NULL; m = m->m_next) { 611 pktwrote += m->m_len; 612 dataoff = shmif_buswrite(busmem, dataoff, mtod(m, void *), 613 m->m_len, &wrap); 614 } 615 KASSERT(pktwrote == pktsize); 616 if (wrap) { 617 busmem->shm_gen++; 618 DPRINTF(("bus generation now %" PRIu64 "\n", busmem->shm_gen)); 619 } 620 shmif_unlockbus(busmem); 621 622 m_freem(m0); 623 if_statinc(ifp, if_opackets); 624 625 DPRINTF(("shmif_start: send %d bytes at off %d\n", pktsize, 626 busmem->shm_last)); 627 } 628 629 static void 630 shmif_stop(struct ifnet *ifp, int disable) 631 { 632 struct shmif_sc *sc = ifp->if_softc; 633 634 ifp->if_flags &= ~IFF_RUNNING; 635 membar_producer(); 636 637 /* 638 * wakeup thread. this will of course wake up all bus 639 * listeners, but that's life. 640 */ 641 if (sc->sc_memfd != -1) { 642 dowakeup(sc); 643 } 644 } 645 646 647 /* 648 * Check if we have been sleeping too long. Basically, 649 * our in-sc nextpkt must by first <= nextpkt <= last"+1". 650 * We use the fact that first is guaranteed to never overlap 651 * with the last frame in the ring. 652 */ 653 static __inline bool 654 stillvalid_p(struct shmif_sc *sc) 655 { 656 struct shmif_mem *busmem = sc->sc_busmem; 657 unsigned gendiff = busmem->shm_gen - sc->sc_devgen; 658 uint32_t lastoff, devoff; 659 660 KASSERT(busmem->shm_first != busmem->shm_last); 661 662 /* normalize onto a 2x busmem chunk */ 663 devoff = sc->sc_nextpacket; 664 lastoff = shmif_nextpktoff(busmem, busmem->shm_last); 665 666 /* trivial case */ 667 if (gendiff > 1) 668 return false; 669 KASSERT(gendiff <= 1); 670 671 /* Normalize onto 2x busmem chunk */ 672 if (busmem->shm_first >= lastoff) { 673 lastoff += BUSMEM_DATASIZE; 674 if (gendiff == 0) 675 devoff += BUSMEM_DATASIZE; 676 } else { 677 if (gendiff) 678 return false; 679 } 680 681 return devoff >= busmem->shm_first && devoff <= lastoff; 682 } 683 684 static void 685 shmif_rcv(void *arg) 686 { 687 struct ifnet *ifp = arg; 688 struct shmif_sc *sc = ifp->if_softc; 689 struct shmif_mem *busmem; 690 struct mbuf *m = NULL; 691 struct ether_header *eth; 692 uint32_t nextpkt; 693 bool wrap, passup; 694 int error; 695 const int align 696 = ALIGN(sizeof(struct ether_header)) - sizeof(struct ether_header); 697 698 reup: 699 mutex_enter(&sc->sc_mtx); 700 while ((ifp->if_flags & IFF_RUNNING) == 0 && !sc->sc_dying) 701 cv_wait(&sc->sc_cv, &sc->sc_mtx); 702 mutex_exit(&sc->sc_mtx); 703 704 busmem = sc->sc_busmem; 705 706 while (ifp->if_flags & IFF_RUNNING) { 707 struct shmif_pkthdr sp; 708 709 if (m == NULL) { 710 m = m_gethdr(M_WAIT, MT_DATA); 711 MCLGET(m, M_WAIT); 712 m->m_data += align; 713 } 714 715 DPRINTF(("waiting %d/%" PRIu64 "\n", 716 sc->sc_nextpacket, sc->sc_devgen)); 717 KASSERT(m->m_flags & M_EXT); 718 719 shmif_lockbus(busmem); 720 KASSERT(busmem->shm_magic == SHMIF_MAGIC); 721 KASSERT(busmem->shm_gen >= sc->sc_devgen); 722 723 /* need more data? */ 724 if (sc->sc_devgen == busmem->shm_gen && 725 shmif_nextpktoff(busmem, busmem->shm_last) 726 == sc->sc_nextpacket) { 727 shmif_unlockbus(busmem); 728 error = rumpcomp_shmif_watchwait(sc->sc_kq); 729 if (__predict_false(error)) 730 printf("shmif_rcv: wait failed %d\n", error); 731 membar_consumer(); 732 continue; 733 } 734 735 if (stillvalid_p(sc)) { 736 nextpkt = sc->sc_nextpacket; 737 } else { 738 KASSERT(busmem->shm_gen > 0); 739 nextpkt = busmem->shm_first; 740 if (busmem->shm_first > busmem->shm_last) 741 sc->sc_devgen = busmem->shm_gen - 1; 742 else 743 sc->sc_devgen = busmem->shm_gen; 744 DPRINTF(("dev %p overrun, new data: %d/%" PRIu64 "\n", 745 sc, nextpkt, sc->sc_devgen)); 746 } 747 748 /* 749 * If our read pointer is ahead the bus last write, our 750 * generation must be one behind. 751 */ 752 KASSERT(!(nextpkt > busmem->shm_last 753 && sc->sc_devgen == busmem->shm_gen)); 754 755 wrap = false; 756 nextpkt = shmif_busread(busmem, &sp, 757 nextpkt, sizeof(sp), &wrap); 758 KASSERT(sp.sp_len <= ETHERMTU + ETHER_HDR_LEN); 759 nextpkt = shmif_busread(busmem, mtod(m, void *), 760 nextpkt, sp.sp_len, &wrap); 761 762 DPRINTF(("shmif_rcv: read packet of length %d at %d\n", 763 sp.sp_len, nextpkt)); 764 765 sc->sc_nextpacket = nextpkt; 766 shmif_unlockbus(sc->sc_busmem); 767 768 if (wrap) { 769 sc->sc_devgen++; 770 DPRINTF(("dev %p generation now %" PRIu64 "\n", 771 sc, sc->sc_devgen)); 772 } 773 774 /* 775 * Ignore packets too short to possibly be valid. 776 * This is hit at least for the first frame on a new bus. 777 */ 778 if (__predict_false(sp.sp_len < ETHER_HDR_LEN)) { 779 DPRINTF(("shmif read packet len %d < ETHER_HDR_LEN\n", 780 sp.sp_len)); 781 continue; 782 } 783 784 m->m_len = m->m_pkthdr.len = sp.sp_len; 785 m_set_rcvif(m, ifp); 786 787 /* 788 * Test if we want to pass the packet upwards 789 */ 790 eth = mtod(m, struct ether_header *); 791 if (sp.sp_sender == sc->sc_uid) { 792 passup = false; 793 } else if (memcmp(eth->ether_dhost, CLLADDR(ifp->if_sadl), 794 ETHER_ADDR_LEN) == 0) { 795 passup = true; 796 } else if (ETHER_IS_MULTICAST(eth->ether_dhost)) { 797 passup = true; 798 } else if (ifp->if_flags & IFF_PROMISC) { 799 m->m_flags |= M_PROMISC; 800 passup = true; 801 } else { 802 passup = false; 803 } 804 805 if (passup) { 806 int bound; 807 808 m = ether_sw_offload_rx(ifp, m); 809 810 KERNEL_LOCK(1, NULL); 811 /* Prevent LWP migrations between CPUs for psref(9) */ 812 bound = curlwp_bind(); 813 if_input(ifp, m); 814 curlwp_bindx(bound); 815 KERNEL_UNLOCK_ONE(NULL); 816 817 m = NULL; 818 } 819 /* else: reuse mbuf for a future packet */ 820 } 821 m_freem(m); 822 m = NULL; 823 824 if (!sc->sc_dying) 825 goto reup; 826 827 kthread_exit(0); 828 } 829
Indexes created Wed Sep 24 05:09:52 GMT 2025