if_tun.c revision 1.115.6.2
1 /* $NetBSD: if_tun.c,v 1.115.6.2 2017/12/03 11:39:02 jdolecek Exp $ */ 2 3 /* 4 * Copyright (c) 1988, Julian Onions <jpo (at) cs.nott.ac.uk> 5 * Nottingham University 1987. 6 * 7 * This source may be freely distributed, however I would be interested 8 * in any changes that are made. 9 * 10 * This driver takes packets off the IP i/f and hands them up to a 11 * user process to have its wicked way with. This driver has its 12 * roots in a similar driver written by Phil Cockcroft (formerly) at 13 * UCL. This driver is based much more on read/write/poll mode of 14 * operation though. 15 */ 16 17 /* 18 * tun - tunnel software network interface. 19 */ 20 21 #include <sys/cdefs.h> 22 __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.115.6.2 2017/12/03 11:39:02 jdolecek Exp $"); 23 24 #ifdef _KERNEL_OPT 25 #include "opt_inet.h" 26 #endif 27 28 #include <sys/param.h> 29 30 #include <sys/buf.h> 31 #include <sys/conf.h> 32 #include <sys/cpu.h> 33 #include <sys/device.h> 34 #include <sys/file.h> 35 #include <sys/ioctl.h> 36 #include <sys/kauth.h> 37 #include <sys/kmem.h> 38 #include <sys/lwp.h> 39 #include <sys/mbuf.h> 40 #include <sys/module.h> 41 #include <sys/mutex.h> 42 #include <sys/poll.h> 43 #include <sys/select.h> 44 #include <sys/signalvar.h> 45 #include <sys/socket.h> 46 47 #include <net/bpf.h> 48 #include <net/if.h> 49 #include <net/if_types.h> 50 #include <net/route.h> 51 52 #ifdef INET 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/in_var.h> 56 #include <netinet/ip.h> 57 #include <netinet/if_inarp.h> 58 #endif 59 60 #include <net/if_tun.h> 61 62 #include "ioconf.h" 63 64 #define TUNDEBUG if (tundebug) printf 65 int tundebug = 0; 66 67 extern int ifqmaxlen; 68 69 static LIST_HEAD(, tun_softc) tun_softc_list; 70 static LIST_HEAD(, tun_softc) tunz_softc_list; 71 static kmutex_t tun_softc_lock; 72 73 static int tun_ioctl(struct ifnet *, u_long, void *); 74 static int tun_output(struct ifnet *, struct mbuf *, 75 const struct sockaddr *, const struct rtentry *rt); 76 static int tun_clone_create(struct if_clone *, int); 77 static int tun_clone_destroy(struct ifnet *); 78 79 static struct if_clone tun_cloner = 80 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 81 82 static void tunattach0(struct tun_softc *); 83 static void tun_enable(struct tun_softc *, const struct ifaddr *); 84 static void tun_i_softintr(void *); 85 static void tun_o_softintr(void *); 86 #ifdef ALTQ 87 static void tunstart(struct ifnet *); 88 #endif 89 static struct tun_softc *tun_find_unit(dev_t); 90 static struct tun_softc *tun_find_zunit(int); 91 92 static dev_type_open(tunopen); 93 static dev_type_close(tunclose); 94 static dev_type_read(tunread); 95 static dev_type_write(tunwrite); 96 static dev_type_ioctl(tunioctl); 97 static dev_type_poll(tunpoll); 98 static dev_type_kqfilter(tunkqfilter); 99 100 const struct cdevsw tun_cdevsw = { 101 .d_open = tunopen, 102 .d_close = tunclose, 103 .d_read = tunread, 104 .d_write = tunwrite, 105 .d_ioctl = tunioctl, 106 .d_stop = nostop, 107 .d_tty = notty, 108 .d_poll = tunpoll, 109 .d_mmap = nommap, 110 .d_kqfilter = tunkqfilter, 111 .d_discard = nodiscard, 112 .d_flag = D_OTHER | D_MPSAFE 113 }; 114 115 #ifdef _MODULE 116 devmajor_t tun_bmajor = -1, tun_cmajor = -1; 117 #endif 118 119 void 120 tunattach(int unused) 121 { 122 123 /* 124 * Nothing to do here, initialization is handled by the 125 * module initialization code in tuninit() below). 126 */ 127 } 128 129 static void 130 tuninit(void) 131 { 132 133 mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NET); 134 LIST_INIT(&tun_softc_list); 135 LIST_INIT(&tunz_softc_list); 136 if_clone_attach(&tun_cloner); 137 #ifdef _MODULE 138 devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); 139 #endif 140 } 141 142 static int 143 tundetach(void) 144 { 145 int error = 0; 146 147 if (!LIST_EMPTY(&tun_softc_list) || !LIST_EMPTY(&tunz_softc_list)) 148 error = EBUSY; 149 150 #ifdef _MODULE 151 if (error == 0) 152 error = devsw_detach(NULL, &tun_cdevsw); 153 #endif 154 if (error == 0) { 155 if_clone_detach(&tun_cloner); 156 mutex_destroy(&tun_softc_lock); 157 } 158 159 return error; 160 } 161 162 /* 163 * Find driver instance from dev_t. 164 * Returns with tp locked (if found). 165 */ 166 static struct tun_softc * 167 tun_find_unit(dev_t dev) 168 { 169 struct tun_softc *tp; 170 int unit = minor(dev); 171 172 mutex_enter(&tun_softc_lock); 173 LIST_FOREACH(tp, &tun_softc_list, tun_list) 174 if (unit == tp->tun_unit) 175 break; 176 if (tp) 177 mutex_enter(&tp->tun_lock); 178 mutex_exit(&tun_softc_lock); 179 180 return tp; 181 } 182 183 /* 184 * Find zombie driver instance by unit number. 185 * Remove tp from list and return it unlocked (if found). 186 */ 187 static struct tun_softc * 188 tun_find_zunit(int unit) 189 { 190 struct tun_softc *tp; 191 192 mutex_enter(&tun_softc_lock); 193 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 194 if (unit == tp->tun_unit) 195 break; 196 if (tp) 197 LIST_REMOVE(tp, tun_list); 198 mutex_exit(&tun_softc_lock); 199 KASSERTMSG(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) == TUN_OPEN, 200 "tun%d: inconsistent flags: %x", unit, tp->tun_flags); 201 202 return tp; 203 } 204 205 static int 206 tun_clone_create(struct if_clone *ifc, int unit) 207 { 208 struct tun_softc *tp; 209 210 if ((tp = tun_find_zunit(unit)) == NULL) { 211 tp = kmem_zalloc(sizeof(*tp), KM_SLEEP); 212 213 tp->tun_unit = unit; 214 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 215 cv_init(&tp->tun_cv, "tunread"); 216 selinit(&tp->tun_rsel); 217 selinit(&tp->tun_wsel); 218 } else { 219 /* Revive tunnel instance; clear ifp part */ 220 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 221 } 222 223 if_initname(&tp->tun_if, ifc->ifc_name, unit); 224 tunattach0(tp); 225 tp->tun_flags |= TUN_INITED; 226 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 227 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 228 229 mutex_enter(&tun_softc_lock); 230 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 231 mutex_exit(&tun_softc_lock); 232 233 return 0; 234 } 235 236 static void 237 tunattach0(struct tun_softc *tp) 238 { 239 struct ifnet *ifp; 240 241 ifp = &tp->tun_if; 242 ifp->if_softc = tp; 243 ifp->if_mtu = TUNMTU; 244 ifp->if_ioctl = tun_ioctl; 245 ifp->if_output = tun_output; 246 #ifdef ALTQ 247 ifp->if_start = tunstart; 248 #endif 249 ifp->if_flags = IFF_POINTOPOINT; 250 ifp->if_extflags = IFEF_NO_LINK_STATE_CHANGE; 251 ifp->if_type = IFT_TUNNEL; 252 ifp->if_snd.ifq_maxlen = ifqmaxlen; 253 ifp->if_collisions = 0; 254 ifp->if_ierrors = 0; 255 ifp->if_oerrors = 0; 256 ifp->if_ipackets = 0; 257 ifp->if_opackets = 0; 258 ifp->if_ibytes = 0; 259 ifp->if_obytes = 0; 260 ifp->if_dlt = DLT_NULL; 261 IFQ_SET_READY(&ifp->if_snd); 262 if_attach(ifp); 263 if_alloc_sadl(ifp); 264 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 265 } 266 267 static int 268 tun_clone_destroy(struct ifnet *ifp) 269 { 270 struct tun_softc *tp = (void *)ifp; 271 bool zombie = false; 272 273 IF_PURGE(&ifp->if_snd); 274 ifp->if_flags &= ~IFF_RUNNING; 275 276 mutex_enter(&tun_softc_lock); 277 mutex_enter(&tp->tun_lock); 278 LIST_REMOVE(tp, tun_list); 279 if (tp->tun_flags & TUN_OPEN) { 280 /* Hang on to storage until last close. */ 281 tp->tun_flags &= ~TUN_INITED; 282 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 283 zombie = true; 284 } 285 mutex_exit(&tun_softc_lock); 286 287 if (tp->tun_flags & TUN_RWAIT) { 288 tp->tun_flags &= ~TUN_RWAIT; 289 cv_broadcast(&tp->tun_cv); 290 } 291 selnotify(&tp->tun_rsel, 0, 0); 292 293 mutex_exit(&tp->tun_lock); 294 295 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 296 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 297 298 bpf_detach(ifp); 299 if_detach(ifp); 300 301 if (!zombie) { 302 seldestroy(&tp->tun_rsel); 303 seldestroy(&tp->tun_wsel); 304 softint_disestablish(tp->tun_osih); 305 softint_disestablish(tp->tun_isih); 306 mutex_destroy(&tp->tun_lock); 307 cv_destroy(&tp->tun_cv); 308 kmem_free(tp, sizeof(*tp)); 309 } 310 311 return 0; 312 } 313 314 /* 315 * tunnel open - must be superuser & the device must be 316 * configured in 317 */ 318 static int 319 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 320 { 321 struct ifnet *ifp; 322 struct tun_softc *tp; 323 int error; 324 325 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 326 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 327 if (error) 328 return error; 329 330 tp = tun_find_unit(dev); 331 332 if (tp == NULL) { 333 (void)tun_clone_create(&tun_cloner, minor(dev)); 334 tp = tun_find_unit(dev); 335 if (tp == NULL) { 336 return ENXIO; 337 } 338 } 339 340 if (tp->tun_flags & TUN_OPEN) { 341 mutex_exit(&tp->tun_lock); 342 return EBUSY; 343 } 344 345 ifp = &tp->tun_if; 346 tp->tun_flags |= TUN_OPEN; 347 TUNDEBUG("%s: open\n", ifp->if_xname); 348 349 mutex_exit(&tp->tun_lock); 350 351 return error; 352 } 353 354 /* 355 * tunclose - close the device - mark i/f down & delete 356 * routing info 357 */ 358 int 359 tunclose(dev_t dev, int flag, int mode, 360 struct lwp *l) 361 { 362 struct tun_softc *tp; 363 struct ifnet *ifp; 364 365 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 366 /* interface was "destroyed" before the close */ 367 seldestroy(&tp->tun_rsel); 368 seldestroy(&tp->tun_wsel); 369 softint_disestablish(tp->tun_osih); 370 softint_disestablish(tp->tun_isih); 371 mutex_destroy(&tp->tun_lock); 372 kmem_free(tp, sizeof(*tp)); 373 return 0; 374 } 375 376 if ((tp = tun_find_unit(dev)) == NULL) 377 goto out_nolock; 378 379 ifp = &tp->tun_if; 380 381 tp->tun_flags &= ~TUN_OPEN; 382 383 tp->tun_pgid = 0; 384 selnotify(&tp->tun_rsel, 0, 0); 385 386 TUNDEBUG ("%s: closed\n", ifp->if_xname); 387 mutex_exit(&tp->tun_lock); 388 389 /* 390 * junk all pending output 391 */ 392 IFQ_PURGE(&ifp->if_snd); 393 394 if (ifp->if_flags & IFF_UP) { 395 if_down(ifp); 396 if (ifp->if_flags & IFF_RUNNING) { 397 /* find internet addresses and delete routes */ 398 struct ifaddr *ifa; 399 IFADDR_READER_FOREACH(ifa, ifp) { 400 #if defined(INET) || defined(INET6) 401 if (ifa->ifa_addr->sa_family == AF_INET || 402 ifa->ifa_addr->sa_family == AF_INET6) { 403 rtinit(ifa, (int)RTM_DELETE, 404 tp->tun_flags & TUN_DSTADDR 405 ? RTF_HOST 406 : 0); 407 } 408 #endif 409 } 410 } 411 } 412 out_nolock: 413 return 0; 414 } 415 416 static void 417 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 418 { 419 struct ifnet *ifp = &tp->tun_if; 420 421 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 422 423 mutex_enter(&tp->tun_lock); 424 ifp->if_flags |= IFF_UP | IFF_RUNNING; 425 426 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 427 428 switch (ifa->ifa_addr->sa_family) { 429 #ifdef INET 430 case AF_INET: { 431 struct sockaddr_in *sin; 432 433 sin = satosin(ifa->ifa_addr); 434 if (sin && sin->sin_addr.s_addr) 435 tp->tun_flags |= TUN_IASET; 436 437 if (ifp->if_flags & IFF_POINTOPOINT) { 438 sin = satosin(ifa->ifa_dstaddr); 439 if (sin && sin->sin_addr.s_addr) 440 tp->tun_flags |= TUN_DSTADDR; 441 } 442 break; 443 } 444 #endif 445 #ifdef INET6 446 case AF_INET6: { 447 struct sockaddr_in6 *sin; 448 449 sin = satosin6(ifa->ifa_addr); 450 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 451 tp->tun_flags |= TUN_IASET; 452 453 if (ifp->if_flags & IFF_POINTOPOINT) { 454 sin = satosin6(ifa->ifa_dstaddr); 455 if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 456 tp->tun_flags |= TUN_DSTADDR; 457 } else 458 tp->tun_flags &= ~TUN_DSTADDR; 459 break; 460 } 461 #endif /* INET6 */ 462 default: 463 break; 464 } 465 mutex_exit(&tp->tun_lock); 466 } 467 468 /* 469 * Process an ioctl request. 470 */ 471 static int 472 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 473 { 474 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 475 struct ifreq *ifr = (struct ifreq *)data; 476 struct ifaddr *ifa = (struct ifaddr *)data; 477 int error = 0; 478 479 switch (cmd) { 480 case SIOCINITIFADDR: 481 tun_enable(tp, ifa); 482 ifa->ifa_rtrequest = p2p_rtrequest; 483 TUNDEBUG("%s: address set\n", ifp->if_xname); 484 break; 485 case SIOCSIFBRDADDR: 486 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 487 break; 488 case SIOCSIFMTU: 489 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 490 error = EINVAL; 491 break; 492 } 493 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 494 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 495 error = 0; 496 break; 497 case SIOCADDMULTI: 498 case SIOCDELMULTI: 499 if (ifr == NULL) { 500 error = EAFNOSUPPORT; /* XXX */ 501 break; 502 } 503 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 504 #ifdef INET 505 case AF_INET: 506 break; 507 #endif 508 #ifdef INET6 509 case AF_INET6: 510 break; 511 #endif 512 default: 513 error = EAFNOSUPPORT; 514 break; 515 } 516 break; 517 default: 518 error = ifioctl_common(ifp, cmd, data); 519 } 520 521 return error; 522 } 523 524 /* 525 * tun_output - queue packets from higher level ready to put out. 526 */ 527 static int 528 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 529 const struct rtentry *rt) 530 { 531 struct tun_softc *tp = ifp->if_softc; 532 int error; 533 #if defined(INET) || defined(INET6) 534 int mlen; 535 uint32_t *af; 536 #endif 537 538 mutex_enter(&tp->tun_lock); 539 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 540 541 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 542 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 543 tp->tun_flags); 544 error = EHOSTDOWN; 545 mutex_exit(&tp->tun_lock); 546 goto out; 547 } 548 // XXXrmind 549 mutex_exit(&tp->tun_lock); 550 551 /* 552 * if the queueing discipline needs packet classification, 553 * do it before prepending link headers. 554 */ 555 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 556 557 bpf_mtap_af(ifp, dst->sa_family, m0); 558 559 switch(dst->sa_family) { 560 #ifdef INET6 561 case AF_INET6: 562 #endif 563 #ifdef INET 564 case AF_INET: 565 #endif 566 #if defined(INET) || defined(INET6) 567 if (tp->tun_flags & TUN_PREPADDR) { 568 /* Simple link-layer header */ 569 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 570 if (m0 == NULL) { 571 IF_DROP(&ifp->if_snd); 572 error = ENOBUFS; 573 goto out; 574 } 575 memcpy(mtod(m0, char *), dst, dst->sa_len); 576 } 577 578 if (tp->tun_flags & TUN_IFHEAD) { 579 /* Prepend the address family */ 580 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 581 if (m0 == NULL) { 582 IF_DROP(&ifp->if_snd); 583 error = ENOBUFS; 584 goto out; 585 } 586 af = mtod(m0,uint32_t *); 587 *af = htonl(dst->sa_family); 588 } else { 589 #ifdef INET 590 if (dst->sa_family != AF_INET) 591 #endif 592 { 593 error = EAFNOSUPPORT; 594 goto out; 595 } 596 } 597 /* FALLTHROUGH */ 598 case AF_UNSPEC: 599 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 600 if (error) { 601 ifp->if_collisions++; 602 error = EAFNOSUPPORT; 603 m0 = NULL; 604 goto out; 605 } 606 mlen = m0->m_pkthdr.len; 607 ifp->if_opackets++; 608 ifp->if_obytes += mlen; 609 break; 610 #endif 611 default: 612 error = EAFNOSUPPORT; 613 goto out; 614 } 615 616 mutex_enter(&tp->tun_lock); 617 if (tp->tun_flags & TUN_RWAIT) { 618 tp->tun_flags &= ~TUN_RWAIT; 619 cv_broadcast(&tp->tun_cv); 620 } 621 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 622 softint_schedule(tp->tun_isih); 623 624 selnotify(&tp->tun_rsel, 0, 0); 625 626 mutex_exit(&tp->tun_lock); 627 out: 628 if (error && m0) { 629 m_freem(m0); 630 } 631 return 0; 632 } 633 634 static void 635 tun_i_softintr(void *cookie) 636 { 637 struct tun_softc *tp = cookie; 638 639 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 640 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 641 NULL); 642 } 643 644 static void 645 tun_o_softintr(void *cookie) 646 { 647 struct tun_softc *tp = cookie; 648 649 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 650 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 651 NULL); 652 } 653 654 /* 655 * the cdevsw interface is now pretty minimal. 656 */ 657 int 658 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 659 { 660 struct tun_softc *tp; 661 int error = 0; 662 663 tp = tun_find_unit(dev); 664 665 /* interface was "destroyed" already */ 666 if (tp == NULL) { 667 return ENXIO; 668 } 669 670 switch (cmd) { 671 case TUNSDEBUG: 672 tundebug = *(int *)data; 673 break; 674 675 case TUNGDEBUG: 676 *(int *)data = tundebug; 677 break; 678 679 case TUNSIFMODE: 680 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 681 case IFF_POINTOPOINT: 682 case IFF_BROADCAST: 683 if (tp->tun_if.if_flags & IFF_UP) { 684 error = EBUSY; 685 goto out; 686 } 687 tp->tun_if.if_flags &= 688 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 689 tp->tun_if.if_flags |= *(int *)data; 690 break; 691 default: 692 error = EINVAL; 693 goto out; 694 } 695 break; 696 697 case TUNSLMODE: 698 if (*(int *)data) { 699 tp->tun_flags |= TUN_PREPADDR; 700 tp->tun_flags &= ~TUN_IFHEAD; 701 } else 702 tp->tun_flags &= ~TUN_PREPADDR; 703 break; 704 705 case TUNSIFHEAD: 706 if (*(int *)data) { 707 tp->tun_flags |= TUN_IFHEAD; 708 tp->tun_flags &= ~TUN_PREPADDR; 709 } else 710 tp->tun_flags &= ~TUN_IFHEAD; 711 break; 712 713 case TUNGIFHEAD: 714 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 715 break; 716 717 case FIONBIO: 718 if (*(int *)data) 719 tp->tun_flags |= TUN_NBIO; 720 else 721 tp->tun_flags &= ~TUN_NBIO; 722 break; 723 724 case FIOASYNC: 725 if (*(int *)data) 726 tp->tun_flags |= TUN_ASYNC; 727 else 728 tp->tun_flags &= ~TUN_ASYNC; 729 break; 730 731 case FIONREAD: 732 if (tp->tun_if.if_snd.ifq_head) 733 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 734 else 735 *(int *)data = 0; 736 break; 737 738 case TIOCSPGRP: 739 case FIOSETOWN: 740 error = fsetown(&tp->tun_pgid, cmd, data); 741 break; 742 743 case TIOCGPGRP: 744 case FIOGETOWN: 745 error = fgetown(tp->tun_pgid, cmd, data); 746 break; 747 748 default: 749 error = ENOTTY; 750 } 751 752 out: 753 mutex_exit(&tp->tun_lock); 754 755 return error; 756 } 757 758 /* 759 * The cdevsw read interface - reads a packet at a time, or at 760 * least as much of a packet as can be read. 761 */ 762 int 763 tunread(dev_t dev, struct uio *uio, int ioflag) 764 { 765 struct tun_softc *tp; 766 struct ifnet *ifp; 767 struct mbuf *m, *m0; 768 int error = 0, len; 769 770 tp = tun_find_unit(dev); 771 772 /* interface was "destroyed" already */ 773 if (tp == NULL) { 774 return ENXIO; 775 } 776 777 ifp = &tp->tun_if; 778 779 TUNDEBUG ("%s: read\n", ifp->if_xname); 780 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 781 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 782 error = EHOSTDOWN; 783 goto out; 784 } 785 786 tp->tun_flags &= ~TUN_RWAIT; 787 788 do { 789 IFQ_DEQUEUE(&ifp->if_snd, m0); 790 if (m0 == 0) { 791 if (tp->tun_flags & TUN_NBIO) { 792 error = EWOULDBLOCK; 793 goto out; 794 } 795 tp->tun_flags |= TUN_RWAIT; 796 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 797 error = EINTR; 798 goto out; 799 } 800 } 801 } while (m0 == 0); 802 803 mutex_exit(&tp->tun_lock); 804 805 /* Copy the mbuf chain */ 806 while (m0 && uio->uio_resid > 0 && error == 0) { 807 len = min(uio->uio_resid, m0->m_len); 808 if (len != 0) 809 error = uiomove(mtod(m0, void *), len, uio); 810 m0 = m = m_free(m0); 811 } 812 813 if (m0) { 814 TUNDEBUG("Dropping mbuf\n"); 815 m_freem(m0); 816 } 817 if (error) 818 ifp->if_ierrors++; 819 820 return error; 821 822 out: 823 mutex_exit(&tp->tun_lock); 824 825 return error; 826 } 827 828 /* 829 * the cdevsw write interface - an atomic write is a packet - or else! 830 */ 831 int 832 tunwrite(dev_t dev, struct uio *uio, int ioflag) 833 { 834 struct tun_softc *tp; 835 struct ifnet *ifp; 836 struct mbuf *top, **mp, *m; 837 pktqueue_t *pktq; 838 struct sockaddr dst; 839 int error = 0, tlen, mlen; 840 uint32_t family; 841 842 tp = tun_find_unit(dev); 843 if (tp == NULL) { 844 /* Interface was "destroyed" already. */ 845 return ENXIO; 846 } 847 848 /* Unlock until we've got the data */ 849 mutex_exit(&tp->tun_lock); 850 851 ifp = &tp->tun_if; 852 853 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 854 855 if (tp->tun_flags & TUN_PREPADDR) { 856 if (uio->uio_resid < sizeof(dst)) { 857 error = EIO; 858 goto out0; 859 } 860 error = uiomove((void *)&dst, sizeof(dst), uio); 861 if (dst.sa_len > sizeof(dst)) { 862 /* Duh.. */ 863 int n = dst.sa_len - sizeof(dst); 864 while (n--) { 865 char discard; 866 error = uiomove(&discard, 1, uio); 867 if (error) { 868 goto out0; 869 } 870 } 871 } 872 } else if (tp->tun_flags & TUN_IFHEAD) { 873 if (uio->uio_resid < sizeof(family)){ 874 error = EIO; 875 goto out0; 876 } 877 error = uiomove((void *)&family, sizeof(family), uio); 878 dst.sa_family = ntohl(family); 879 } else { 880 #ifdef INET 881 dst.sa_family = AF_INET; 882 #endif 883 } 884 885 if (uio->uio_resid > TUNMTU) { 886 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 887 (unsigned long)uio->uio_resid); 888 error = EIO; 889 goto out0; 890 } 891 892 switch (dst.sa_family) { 893 #ifdef INET 894 case AF_INET: 895 pktq = ip_pktq; 896 break; 897 #endif 898 #ifdef INET6 899 case AF_INET6: 900 pktq = ip6_pktq; 901 break; 902 #endif 903 default: 904 error = EAFNOSUPPORT; 905 goto out0; 906 } 907 908 tlen = uio->uio_resid; 909 910 /* get a header mbuf */ 911 MGETHDR(m, M_DONTWAIT, MT_DATA); 912 if (m == NULL) { 913 return ENOBUFS; 914 } 915 mlen = MHLEN; 916 917 top = NULL; 918 mp = ⊤ 919 while (error == 0 && uio->uio_resid > 0) { 920 m->m_len = min(mlen, uio->uio_resid); 921 error = uiomove(mtod(m, void *), m->m_len, uio); 922 *mp = m; 923 mp = &m->m_next; 924 if (error == 0 && uio->uio_resid > 0) { 925 MGET(m, M_DONTWAIT, MT_DATA); 926 if (m == NULL) { 927 error = ENOBUFS; 928 break; 929 } 930 mlen = MLEN; 931 } 932 } 933 if (error) { 934 if (top != NULL) 935 m_freem(top); 936 ifp->if_ierrors++; 937 goto out0; 938 } 939 940 top->m_pkthdr.len = tlen; 941 m_set_rcvif(top, ifp); 942 943 bpf_mtap_af(ifp, dst.sa_family, top); 944 945 mutex_enter(&tp->tun_lock); 946 if ((tp->tun_flags & TUN_INITED) == 0) { 947 /* Interface was destroyed */ 948 error = ENXIO; 949 goto out; 950 } 951 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 952 ifp->if_collisions++; 953 mutex_exit(&tp->tun_lock); 954 error = ENOBUFS; 955 m_freem(top); 956 goto out0; 957 } 958 ifp->if_ipackets++; 959 ifp->if_ibytes += tlen; 960 out: 961 mutex_exit(&tp->tun_lock); 962 out0: 963 return error; 964 } 965 966 #ifdef ALTQ 967 /* 968 * Start packet transmission on the interface. 969 * when the interface queue is rate-limited by ALTQ or TBR, 970 * if_start is needed to drain packets from the queue in order 971 * to notify readers when outgoing packets become ready. 972 */ 973 static void 974 tunstart(struct ifnet *ifp) 975 { 976 struct tun_softc *tp = ifp->if_softc; 977 978 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 979 return; 980 981 mutex_enter(&tp->tun_lock); 982 if (!IF_IS_EMPTY(&ifp->if_snd)) { 983 if (tp->tun_flags & TUN_RWAIT) { 984 tp->tun_flags &= ~TUN_RWAIT; 985 cv_broadcast(&tp->tun_cv); 986 } 987 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 988 softint_schedule(tp->tun_osih); 989 990 selnotify(&tp->tun_rsel, 0, 0); 991 } 992 mutex_exit(&tp->tun_lock); 993 } 994 #endif /* ALTQ */ 995 /* 996 * tunpoll - the poll interface, this is only useful on reads 997 * really. The write detect always returns true, write never blocks 998 * anyway, it either accepts the packet or drops it. 999 */ 1000 int 1001 tunpoll(dev_t dev, int events, struct lwp *l) 1002 { 1003 struct tun_softc *tp; 1004 struct ifnet *ifp; 1005 int revents = 0; 1006 1007 tp = tun_find_unit(dev); 1008 if (tp == NULL) { 1009 /* Interface was "destroyed" already. */ 1010 return 0; 1011 } 1012 ifp = &tp->tun_if; 1013 1014 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1015 1016 if (events & (POLLIN | POLLRDNORM)) { 1017 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1018 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1019 ifp->if_snd.ifq_len); 1020 revents |= events & (POLLIN | POLLRDNORM); 1021 } else { 1022 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1023 selrecord(l, &tp->tun_rsel); 1024 } 1025 } 1026 1027 if (events & (POLLOUT | POLLWRNORM)) 1028 revents |= events & (POLLOUT | POLLWRNORM); 1029 1030 mutex_exit(&tp->tun_lock); 1031 1032 return revents; 1033 } 1034 1035 static void 1036 filt_tunrdetach(struct knote *kn) 1037 { 1038 struct tun_softc *tp = kn->kn_hook; 1039 1040 mutex_enter(&tp->tun_lock); 1041 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1042 mutex_exit(&tp->tun_lock); 1043 } 1044 1045 static int 1046 filt_tunread(struct knote *kn, long hint) 1047 { 1048 struct tun_softc *tp = kn->kn_hook; 1049 struct ifnet *ifp = &tp->tun_if; 1050 struct mbuf *m; 1051 1052 mutex_enter(&tp->tun_lock); 1053 IF_POLL(&ifp->if_snd, m); 1054 if (m == NULL) { 1055 mutex_exit(&tp->tun_lock); 1056 return 0; 1057 } 1058 1059 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1060 kn->kn_data += m->m_len; 1061 1062 mutex_exit(&tp->tun_lock); 1063 1064 return 1; 1065 } 1066 1067 static const struct filterops tunread_filtops = { 1068 .f_isfd = 1, 1069 .f_attach = NULL, 1070 .f_detach = filt_tunrdetach, 1071 .f_event = filt_tunread, 1072 }; 1073 1074 static const struct filterops tun_seltrue_filtops = { 1075 .f_isfd = 1, 1076 .f_attach = NULL, 1077 .f_detach = filt_tunrdetach, 1078 .f_event = filt_seltrue, 1079 }; 1080 1081 int 1082 tunkqfilter(dev_t dev, struct knote *kn) 1083 { 1084 struct tun_softc *tp; 1085 struct klist *klist; 1086 int rv = 0; 1087 1088 tp = tun_find_unit(dev); 1089 if (tp == NULL) 1090 goto out_nolock; 1091 1092 switch (kn->kn_filter) { 1093 case EVFILT_READ: 1094 klist = &tp->tun_rsel.sel_klist; 1095 kn->kn_fop = &tunread_filtops; 1096 break; 1097 1098 case EVFILT_WRITE: 1099 klist = &tp->tun_rsel.sel_klist; 1100 kn->kn_fop = &tun_seltrue_filtops; 1101 break; 1102 1103 default: 1104 rv = EINVAL; 1105 goto out; 1106 } 1107 1108 kn->kn_hook = tp; 1109 1110 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1111 1112 out: 1113 mutex_exit(&tp->tun_lock); 1114 out_nolock: 1115 return rv; 1116 } 1117 1118 /* 1119 * Module infrastructure 1120 */ 1121 #include "if_module.h" 1122 1123 IF_MODULE(MODULE_CLASS_DRIVER, tun, "") 1124
Indexes created Fri Oct 17 03:10:13 GMT 2025