1 /* $NetBSD: if_tun.c,v 1.173 2022/03/28 12:33:22 riastradh Exp $ */ 2 3 /* 4 * Copyright (c) 1988, Julian Onions <jpo@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 1.173 2022/03/28 12:33:22 riastradh 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_NONE); 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 { 145 146 if_clone_detach(&tun_cloner); 147 #ifdef _MODULE 148 devsw_detach(NULL, &tun_cdevsw); 149 #endif 150 151 if (!LIST_EMPTY(&tun_softc_list) || !LIST_EMPTY(&tunz_softc_list)) { 152 #ifdef _MODULE 153 devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); 154 #endif 155 if_clone_attach(&tun_cloner); 156 return EBUSY; 157 } 158 159 mutex_destroy(&tun_softc_lock); 160 161 return 0; 162 } 163 164 /* 165 * Find driver instance from dev_t. 166 * Returns with tp locked (if found). 167 */ 168 static struct tun_softc * 169 tun_find_unit(dev_t dev) 170 { 171 struct tun_softc *tp; 172 int unit = minor(dev); 173 174 mutex_enter(&tun_softc_lock); 175 LIST_FOREACH(tp, &tun_softc_list, tun_list) 176 if (unit == tp->tun_unit) 177 break; 178 if (tp) 179 mutex_enter(&tp->tun_lock); 180 mutex_exit(&tun_softc_lock); 181 182 return tp; 183 } 184 185 /* 186 * Find zombie driver instance by unit number. 187 * Remove tp from list and return it unlocked (if found). 188 */ 189 static struct tun_softc * 190 tun_find_zunit(int unit) 191 { 192 struct tun_softc *tp; 193 194 mutex_enter(&tun_softc_lock); 195 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 196 if (unit == tp->tun_unit) 197 break; 198 if (tp) 199 LIST_REMOVE(tp, tun_list); 200 mutex_exit(&tun_softc_lock); 201 KASSERTMSG(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) == TUN_OPEN, 202 "tun%d: inconsistent flags: %x", unit, tp->tun_flags); 203 204 return tp; 205 } 206 207 static void 208 tun_init(struct tun_softc *tp, int unit) 209 { 210 211 tp->tun_unit = unit; 212 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_SOFTNET); 213 cv_init(&tp->tun_cv, "tunread"); 214 selinit(&tp->tun_rsel); 215 selinit(&tp->tun_wsel); 216 217 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 218 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 219 } 220 221 static void 222 tun_fini(struct tun_softc *tp) 223 { 224 225 softint_disestablish(tp->tun_isih); 226 softint_disestablish(tp->tun_osih); 227 228 seldestroy(&tp->tun_wsel); 229 seldestroy(&tp->tun_rsel); 230 mutex_destroy(&tp->tun_lock); 231 cv_destroy(&tp->tun_cv); 232 } 233 234 static struct tun_softc * 235 tun_alloc(int unit) 236 { 237 struct tun_softc *tp; 238 239 tp = kmem_zalloc(sizeof(*tp), KM_SLEEP); 240 tun_init(tp, unit); 241 242 return tp; 243 } 244 245 static void 246 tun_recycle(struct tun_softc *tp) 247 { 248 249 memset(&tp->tun_if, 0, sizeof(struct ifnet)); /* XXX ??? */ 250 } 251 252 static void 253 tun_free(struct tun_softc *tp) 254 { 255 256 tun_fini(tp); 257 kmem_free(tp, sizeof(*tp)); 258 } 259 260 static int 261 tun_clone_create(struct if_clone *ifc, int unit) 262 { 263 struct tun_softc *tp; 264 265 if ((tp = tun_find_zunit(unit)) == NULL) { 266 tp = tun_alloc(unit); 267 } else { 268 tun_recycle(tp); 269 } 270 271 if_initname(&tp->tun_if, ifc->ifc_name, unit); 272 tunattach0(tp); 273 tp->tun_flags |= TUN_INITED; 274 275 mutex_enter(&tun_softc_lock); 276 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 277 mutex_exit(&tun_softc_lock); 278 279 return 0; 280 } 281 282 static void 283 tunattach0(struct tun_softc *tp) 284 { 285 struct ifnet *ifp; 286 287 ifp = &tp->tun_if; 288 ifp->if_softc = tp; 289 ifp->if_mtu = TUNMTU; 290 ifp->if_ioctl = tun_ioctl; 291 ifp->if_output = tun_output; 292 #ifdef ALTQ 293 ifp->if_start = tunstart; 294 #endif 295 ifp->if_flags = IFF_POINTOPOINT; 296 ifp->if_type = IFT_TUNNEL; 297 ifp->if_snd.ifq_maxlen = ifqmaxlen; 298 ifp->if_dlt = DLT_NULL; 299 IFQ_SET_READY(&ifp->if_snd); 300 if_attach(ifp); 301 ifp->if_link_state = LINK_STATE_DOWN; 302 if_alloc_sadl(ifp); 303 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 304 } 305 306 static int 307 tun_clone_destroy(struct ifnet *ifp) 308 { 309 struct tun_softc *tp = (void *)ifp; 310 bool zombie = false; 311 312 IF_PURGE(&ifp->if_snd); 313 ifp->if_flags &= ~IFF_RUNNING; 314 315 mutex_enter(&tun_softc_lock); 316 mutex_enter(&tp->tun_lock); 317 LIST_REMOVE(tp, tun_list); 318 if (tp->tun_flags & TUN_OPEN) { 319 /* Hang on to storage until last close. */ 320 tp->tun_flags &= ~TUN_INITED; 321 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 322 zombie = true; 323 } 324 mutex_exit(&tun_softc_lock); 325 326 cv_broadcast(&tp->tun_cv); 327 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 328 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 329 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 330 mutex_exit(&tp->tun_lock); 331 332 bpf_detach(ifp); 333 if_detach(ifp); 334 335 if (!zombie) { 336 tun_free(tp); 337 } 338 339 return 0; 340 } 341 342 /* 343 * tunnel open - must be superuser & the device must be 344 * configured in 345 */ 346 static int 347 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 348 { 349 struct ifnet *ifp; 350 struct tun_softc *tp; 351 int error; 352 353 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 354 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 355 if (error) 356 return error; 357 358 tp = tun_find_unit(dev); 359 360 if (tp == NULL) { 361 (void)tun_clone_create(&tun_cloner, minor(dev)); 362 tp = tun_find_unit(dev); 363 if (tp == NULL) { 364 return ENXIO; 365 } 366 } 367 368 if (tp->tun_flags & TUN_OPEN) { 369 mutex_exit(&tp->tun_lock); 370 return EBUSY; 371 } 372 373 ifp = &tp->tun_if; 374 tp->tun_flags |= TUN_OPEN; 375 TUNDEBUG("%s: open\n", ifp->if_xname); 376 if_link_state_change(ifp, LINK_STATE_UP); 377 378 mutex_exit(&tp->tun_lock); 379 380 return error; 381 } 382 383 /* 384 * tunclose - close the device - mark i/f down & delete 385 * routing info 386 */ 387 int 388 tunclose(dev_t dev, int flag, int mode, 389 struct lwp *l) 390 { 391 struct tun_softc *tp; 392 struct ifnet *ifp; 393 394 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 395 /* interface was "destroyed" before the close */ 396 tun_free(tp); 397 return 0; 398 } 399 400 if ((tp = tun_find_unit(dev)) == NULL) 401 goto out_nolock; 402 403 ifp = &tp->tun_if; 404 405 tp->tun_flags &= ~TUN_OPEN; 406 407 tp->tun_pgid = 0; 408 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 409 410 TUNDEBUG ("%s: closed\n", ifp->if_xname); 411 mutex_exit(&tp->tun_lock); 412 413 /* 414 * junk all pending output 415 */ 416 IFQ_PURGE(&ifp->if_snd); 417 418 if (ifp->if_flags & IFF_UP) { 419 if_down(ifp); 420 if (ifp->if_flags & IFF_RUNNING) { 421 /* find internet addresses and delete routes */ 422 struct ifaddr *ifa; 423 IFADDR_READER_FOREACH(ifa, ifp) { 424 #if defined(INET) || defined(INET6) 425 if (ifa->ifa_addr->sa_family == AF_INET || 426 ifa->ifa_addr->sa_family == AF_INET6) { 427 rtinit(ifa, (int)RTM_DELETE, 428 tp->tun_flags & TUN_DSTADDR 429 ? RTF_HOST 430 : 0); 431 } 432 #endif 433 } 434 } 435 } 436 437 if_link_state_change(ifp, LINK_STATE_DOWN); 438 439 out_nolock: 440 return 0; 441 } 442 443 static void 444 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 445 { 446 struct ifnet *ifp = &tp->tun_if; 447 448 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 449 450 mutex_enter(&tp->tun_lock); 451 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 452 453 switch (ifa->ifa_addr->sa_family) { 454 #ifdef INET 455 case AF_INET: { 456 struct sockaddr_in *sin; 457 458 sin = satosin(ifa->ifa_addr); 459 if (sin && sin->sin_addr.s_addr) 460 tp->tun_flags |= TUN_IASET; 461 462 if (ifp->if_flags & IFF_POINTOPOINT) { 463 sin = satosin(ifa->ifa_dstaddr); 464 if (sin && sin->sin_addr.s_addr) 465 tp->tun_flags |= TUN_DSTADDR; 466 } 467 break; 468 } 469 #endif 470 #ifdef INET6 471 case AF_INET6: { 472 struct sockaddr_in6 *sin; 473 474 sin = satosin6(ifa->ifa_addr); 475 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 476 tp->tun_flags |= TUN_IASET; 477 478 if (ifp->if_flags & IFF_POINTOPOINT) { 479 sin = satosin6(ifa->ifa_dstaddr); 480 if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 481 tp->tun_flags |= TUN_DSTADDR; 482 } else 483 tp->tun_flags &= ~TUN_DSTADDR; 484 break; 485 } 486 #endif /* INET6 */ 487 default: 488 break; 489 } 490 ifp->if_flags |= IFF_UP | IFF_RUNNING; 491 mutex_exit(&tp->tun_lock); 492 } 493 494 /* 495 * Process an ioctl request. 496 */ 497 static int 498 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 499 { 500 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 501 struct ifreq *ifr = (struct ifreq *)data; 502 struct ifaddr *ifa = (struct ifaddr *)data; 503 int error = 0; 504 505 switch (cmd) { 506 case SIOCINITIFADDR: 507 tun_enable(tp, ifa); 508 ifa->ifa_rtrequest = p2p_rtrequest; 509 TUNDEBUG("%s: address set\n", ifp->if_xname); 510 break; 511 case SIOCSIFBRDADDR: 512 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 513 break; 514 case SIOCSIFMTU: 515 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 516 error = EINVAL; 517 break; 518 } 519 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 520 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 521 error = 0; 522 break; 523 case SIOCADDMULTI: 524 case SIOCDELMULTI: 525 if (ifr == NULL) { 526 error = EAFNOSUPPORT; /* XXX */ 527 break; 528 } 529 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 530 #ifdef INET 531 case AF_INET: 532 break; 533 #endif 534 #ifdef INET6 535 case AF_INET6: 536 break; 537 #endif 538 default: 539 error = EAFNOSUPPORT; 540 break; 541 } 542 break; 543 default: 544 error = ifioctl_common(ifp, cmd, data); 545 } 546 547 return error; 548 } 549 550 /* 551 * tun_output - queue packets from higher level ready to put out. 552 */ 553 static int 554 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 555 const struct rtentry *rt) 556 { 557 struct tun_softc *tp = ifp->if_softc; 558 int error; 559 #if defined(INET) || defined(INET6) 560 int mlen; 561 uint32_t *af; 562 #endif 563 564 mutex_enter(&tp->tun_lock); 565 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 566 567 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 568 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 569 tp->tun_flags); 570 error = EHOSTDOWN; 571 mutex_exit(&tp->tun_lock); 572 goto out; 573 } 574 // XXXrmind 575 mutex_exit(&tp->tun_lock); 576 577 /* 578 * if the queueing discipline needs packet classification, 579 * do it before prepending link headers. 580 */ 581 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 582 583 bpf_mtap_af(ifp, dst->sa_family, m0, BPF_D_OUT); 584 585 if ((error = pfil_run_hooks(ifp->if_pfil, &m0, ifp, PFIL_OUT)) != 0) 586 goto out; 587 if (m0 == NULL) 588 goto out; 589 590 switch(dst->sa_family) { 591 #ifdef INET6 592 case AF_INET6: 593 #endif 594 #ifdef INET 595 case AF_INET: 596 #endif 597 #if defined(INET) || defined(INET6) 598 if (tp->tun_flags & TUN_PREPADDR) { 599 /* Simple link-layer header */ 600 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 601 if (m0 == NULL) { 602 IF_DROP(&ifp->if_snd); 603 error = ENOBUFS; 604 goto out; 605 } 606 memcpy(mtod(m0, char *), dst, dst->sa_len); 607 } 608 609 if (tp->tun_flags & TUN_IFHEAD) { 610 /* Prepend the address family */ 611 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 612 if (m0 == NULL) { 613 IF_DROP(&ifp->if_snd); 614 error = ENOBUFS; 615 goto out; 616 } 617 af = mtod(m0,uint32_t *); 618 *af = htonl(dst->sa_family); 619 } else { 620 #ifdef INET 621 if (dst->sa_family != AF_INET) 622 #endif 623 { 624 error = EAFNOSUPPORT; 625 goto out; 626 } 627 } 628 /* FALLTHROUGH */ 629 case AF_UNSPEC: 630 mlen = m0->m_pkthdr.len; 631 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 632 if (error) { 633 if_statinc(ifp, if_collisions); 634 error = EAFNOSUPPORT; 635 m0 = NULL; 636 goto out; 637 } 638 if_statadd2(ifp, if_opackets, 1, if_obytes, mlen); 639 break; 640 #endif 641 default: 642 error = EAFNOSUPPORT; 643 goto out; 644 } 645 646 mutex_enter(&tp->tun_lock); 647 cv_broadcast(&tp->tun_cv); 648 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 649 softint_schedule(tp->tun_isih); 650 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 651 mutex_exit(&tp->tun_lock); 652 out: 653 if (error && m0) 654 m_freem(m0); 655 656 return error; 657 } 658 659 static void 660 tun_i_softintr(void *cookie) 661 { 662 struct tun_softc *tp = cookie; 663 664 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 665 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 666 NULL); 667 } 668 669 static void 670 tun_o_softintr(void *cookie) 671 { 672 struct tun_softc *tp = cookie; 673 674 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 675 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 676 NULL); 677 } 678 679 /* 680 * the cdevsw interface is now pretty minimal. 681 */ 682 int 683 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 684 { 685 struct tun_softc *tp; 686 int error = 0; 687 688 tp = tun_find_unit(dev); 689 690 /* interface was "destroyed" already */ 691 if (tp == NULL) { 692 return ENXIO; 693 } 694 695 switch (cmd) { 696 case TUNSDEBUG: 697 tundebug = *(int *)data; 698 break; 699 700 case TUNGDEBUG: 701 *(int *)data = tundebug; 702 break; 703 704 case TUNSIFMODE: 705 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 706 case IFF_POINTOPOINT: 707 case IFF_BROADCAST: 708 if (tp->tun_if.if_flags & IFF_UP) { 709 error = EBUSY; 710 goto out; 711 } 712 tp->tun_if.if_flags &= 713 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 714 tp->tun_if.if_flags |= *(int *)data; 715 break; 716 default: 717 error = EINVAL; 718 goto out; 719 } 720 break; 721 722 case TUNSLMODE: 723 if (*(int *)data) { 724 tp->tun_flags |= TUN_PREPADDR; 725 tp->tun_flags &= ~TUN_IFHEAD; 726 } else 727 tp->tun_flags &= ~TUN_PREPADDR; 728 break; 729 730 case TUNSIFHEAD: 731 if (*(int *)data) { 732 tp->tun_flags |= TUN_IFHEAD; 733 tp->tun_flags &= ~TUN_PREPADDR; 734 } else 735 tp->tun_flags &= ~TUN_IFHEAD; 736 break; 737 738 case TUNGIFHEAD: 739 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 740 break; 741 742 case FIONBIO: 743 if (*(int *)data) 744 tp->tun_flags |= TUN_NBIO; 745 else 746 tp->tun_flags &= ~TUN_NBIO; 747 break; 748 749 case FIOASYNC: 750 if (*(int *)data) 751 tp->tun_flags |= TUN_ASYNC; 752 else 753 tp->tun_flags &= ~TUN_ASYNC; 754 break; 755 756 case FIONREAD: 757 if (tp->tun_if.if_snd.ifq_head) 758 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 759 else 760 *(int *)data = 0; 761 break; 762 763 case TIOCSPGRP: 764 case FIOSETOWN: 765 error = fsetown(&tp->tun_pgid, cmd, data); 766 break; 767 768 case TIOCGPGRP: 769 case FIOGETOWN: 770 error = fgetown(tp->tun_pgid, cmd, data); 771 break; 772 773 default: 774 error = ENOTTY; 775 } 776 777 out: 778 mutex_exit(&tp->tun_lock); 779 780 return error; 781 } 782 783 /* 784 * The cdevsw read interface - reads a packet at a time, or at 785 * least as much of a packet as can be read. 786 */ 787 int 788 tunread(dev_t dev, struct uio *uio, int ioflag) 789 { 790 struct tun_softc *tp; 791 struct ifnet *ifp; 792 struct mbuf *m, *m0; 793 int error = 0, len; 794 795 tp = tun_find_unit(dev); 796 797 /* interface was "destroyed" already */ 798 if (tp == NULL) { 799 return ENXIO; 800 } 801 802 ifp = &tp->tun_if; 803 804 TUNDEBUG ("%s: read\n", ifp->if_xname); 805 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 806 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 807 error = EHOSTDOWN; 808 goto out; 809 } 810 811 do { 812 IFQ_DEQUEUE(&ifp->if_snd, m0); 813 if (m0 == 0) { 814 if (tp->tun_flags & TUN_NBIO) { 815 error = EWOULDBLOCK; 816 goto out; 817 } 818 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 819 error = EINTR; 820 goto out; 821 } 822 } 823 } while (m0 == 0); 824 825 mutex_exit(&tp->tun_lock); 826 827 /* Copy the mbuf chain */ 828 while (m0 && uio->uio_resid > 0 && error == 0) { 829 len = uimin(uio->uio_resid, m0->m_len); 830 if (len != 0) 831 error = uiomove(mtod(m0, void *), len, uio); 832 m0 = m = m_free(m0); 833 } 834 835 if (m0) { 836 TUNDEBUG("Dropping mbuf\n"); 837 m_freem(m0); 838 } 839 if (error) 840 if_statinc(ifp, if_ierrors); 841 842 return error; 843 844 out: 845 mutex_exit(&tp->tun_lock); 846 847 return error; 848 } 849 850 /* 851 * the cdevsw write interface - an atomic write is a packet - or else! 852 */ 853 int 854 tunwrite(dev_t dev, struct uio *uio, int ioflag) 855 { 856 struct tun_softc *tp; 857 struct ifnet *ifp; 858 struct mbuf *top, **mp, *m; 859 pktqueue_t *pktq; 860 struct sockaddr dst; 861 int error = 0, tlen, mlen; 862 uint32_t family; 863 864 tp = tun_find_unit(dev); 865 if (tp == NULL) { 866 /* Interface was "destroyed" already. */ 867 return ENXIO; 868 } 869 870 /* Unlock until we've got the data */ 871 mutex_exit(&tp->tun_lock); 872 873 ifp = &tp->tun_if; 874 875 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 876 877 if (tp->tun_flags & TUN_PREPADDR) { 878 if (uio->uio_resid < sizeof(dst)) { 879 error = EIO; 880 goto out0; 881 } 882 error = uiomove((void *)&dst, sizeof(dst), uio); 883 if (error) 884 goto out0; 885 if (dst.sa_len > sizeof(dst)) { 886 /* Duh.. */ 887 int n = dst.sa_len - sizeof(dst); 888 while (n--) { 889 char discard; 890 error = uiomove(&discard, 1, uio); 891 if (error) { 892 goto out0; 893 } 894 } 895 } 896 } else if (tp->tun_flags & TUN_IFHEAD) { 897 if (uio->uio_resid < sizeof(family)){ 898 error = EIO; 899 goto out0; 900 } 901 error = uiomove((void *)&family, sizeof(family), uio); 902 if (error) 903 goto out0; 904 dst.sa_family = ntohl(family); 905 } else { 906 #ifdef INET 907 dst.sa_family = AF_INET; 908 #endif 909 } 910 911 if (uio->uio_resid == 0 || uio->uio_resid > TUNMTU) { 912 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 913 (unsigned long)uio->uio_resid); 914 error = EIO; 915 goto out0; 916 } 917 918 switch (dst.sa_family) { 919 #ifdef INET 920 case AF_INET: 921 pktq = ip_pktq; 922 break; 923 #endif 924 #ifdef INET6 925 case AF_INET6: 926 pktq = ip6_pktq; 927 break; 928 #endif 929 default: 930 error = EAFNOSUPPORT; 931 goto out0; 932 } 933 934 tlen = uio->uio_resid; 935 936 /* get a header mbuf */ 937 MGETHDR(m, M_DONTWAIT, MT_DATA); 938 if (m == NULL) { 939 error = ENOBUFS; 940 goto out0; 941 } 942 mlen = MHLEN; 943 944 top = NULL; 945 mp = ⊤ 946 while (error == 0 && uio->uio_resid > 0) { 947 m->m_len = uimin(mlen, uio->uio_resid); 948 error = uiomove(mtod(m, void *), m->m_len, uio); 949 *mp = m; 950 mp = &m->m_next; 951 if (error == 0 && uio->uio_resid > 0) { 952 MGET(m, M_DONTWAIT, MT_DATA); 953 if (m == NULL) { 954 error = ENOBUFS; 955 break; 956 } 957 mlen = MLEN; 958 } 959 } 960 if (error) { 961 if (top != NULL) 962 m_freem(top); 963 if_statinc(ifp, if_ierrors); 964 goto out0; 965 } 966 967 top->m_pkthdr.len = tlen; 968 m_set_rcvif(top, ifp); 969 970 bpf_mtap_af(ifp, dst.sa_family, top, BPF_D_IN); 971 972 if ((error = pfil_run_hooks(ifp->if_pfil, &top, ifp, PFIL_IN)) != 0) 973 goto out0; 974 if (top == NULL) 975 goto out0; 976 977 mutex_enter(&tp->tun_lock); 978 if ((tp->tun_flags & TUN_INITED) == 0) { 979 /* Interface was destroyed */ 980 error = ENXIO; 981 goto out; 982 } 983 kpreempt_disable(); 984 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 985 if_statinc(ifp, if_collisions); 986 mutex_exit(&tp->tun_lock); 987 error = ENOBUFS; 988 m_freem(top); 989 goto out0; 990 } 991 kpreempt_enable(); 992 if_statadd2(ifp, if_ipackets, 1, if_ibytes, tlen); 993 out: 994 mutex_exit(&tp->tun_lock); 995 out0: 996 return error; 997 } 998 999 #ifdef ALTQ 1000 /* 1001 * Start packet transmission on the interface. 1002 * when the interface queue is rate-limited by ALTQ or TBR, 1003 * if_start is needed to drain packets from the queue in order 1004 * to notify readers when outgoing packets become ready. 1005 */ 1006 static void 1007 tunstart(struct ifnet *ifp) 1008 { 1009 struct tun_softc *tp = ifp->if_softc; 1010 1011 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 1012 return; 1013 1014 mutex_enter(&tp->tun_lock); 1015 if (!IF_IS_EMPTY(&ifp->if_snd)) { 1016 cv_broadcast(&tp->tun_cv); 1017 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 1018 softint_schedule(tp->tun_osih); 1019 1020 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 1021 } 1022 mutex_exit(&tp->tun_lock); 1023 } 1024 #endif /* ALTQ */ 1025 /* 1026 * tunpoll - the poll interface, this is only useful on reads 1027 * really. The write detect always returns true, write never blocks 1028 * anyway, it either accepts the packet or drops it. 1029 */ 1030 int 1031 tunpoll(dev_t dev, int events, struct lwp *l) 1032 { 1033 struct tun_softc *tp; 1034 struct ifnet *ifp; 1035 int revents = 0; 1036 1037 tp = tun_find_unit(dev); 1038 if (tp == NULL) { 1039 /* Interface was "destroyed" already. */ 1040 return 0; 1041 } 1042 ifp = &tp->tun_if; 1043 1044 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1045 1046 if (events & (POLLIN | POLLRDNORM)) { 1047 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1048 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1049 ifp->if_snd.ifq_len); 1050 revents |= events & (POLLIN | POLLRDNORM); 1051 } else { 1052 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1053 selrecord(l, &tp->tun_rsel); 1054 } 1055 } 1056 1057 if (events & (POLLOUT | POLLWRNORM)) 1058 revents |= events & (POLLOUT | POLLWRNORM); 1059 1060 mutex_exit(&tp->tun_lock); 1061 1062 return revents; 1063 } 1064 1065 static void 1066 filt_tunrdetach(struct knote *kn) 1067 { 1068 struct tun_softc *tp = kn->kn_hook; 1069 1070 mutex_enter(&tp->tun_lock); 1071 selremove_knote(&tp->tun_rsel, kn); 1072 mutex_exit(&tp->tun_lock); 1073 } 1074 1075 static int 1076 filt_tunread(struct knote *kn, long hint) 1077 { 1078 struct tun_softc *tp = kn->kn_hook; 1079 struct ifnet *ifp = &tp->tun_if; 1080 struct mbuf *m; 1081 int ready; 1082 1083 if (hint & NOTE_SUBMIT) 1084 KASSERT(mutex_owned(&tp->tun_lock)); 1085 else 1086 mutex_enter(&tp->tun_lock); 1087 1088 IF_POLL(&ifp->if_snd, m); 1089 ready = (m != NULL); 1090 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1091 kn->kn_data += m->m_len; 1092 1093 if (hint & NOTE_SUBMIT) 1094 KASSERT(mutex_owned(&tp->tun_lock)); 1095 else 1096 mutex_exit(&tp->tun_lock); 1097 1098 return ready; 1099 } 1100 1101 static const struct filterops tunread_filtops = { 1102 .f_flags = FILTEROP_ISFD, 1103 .f_attach = NULL, 1104 .f_detach = filt_tunrdetach, 1105 .f_event = filt_tunread, 1106 }; 1107 1108 int 1109 tunkqfilter(dev_t dev, struct knote *kn) 1110 { 1111 struct tun_softc *tp; 1112 int rv = 0; 1113 1114 tp = tun_find_unit(dev); 1115 if (tp == NULL) 1116 goto out_nolock; 1117 1118 switch (kn->kn_filter) { 1119 case EVFILT_READ: 1120 kn->kn_fop = &tunread_filtops; 1121 kn->kn_hook = tp; 1122 selrecord_knote(&tp->tun_rsel, kn); 1123 break; 1124 1125 case EVFILT_WRITE: 1126 kn->kn_fop = &seltrue_filtops; 1127 break; 1128 1129 default: 1130 rv = EINVAL; 1131 goto out; 1132 } 1133 1134 out: 1135 mutex_exit(&tp->tun_lock); 1136 out_nolock: 1137 return rv; 1138 } 1139 1140 /* 1141 * Module infrastructure 1142 */ 1143 #include "if_module.h" 1144 1145 IF_MODULE(MODULE_CLASS_DRIVER, tun, NULL) 1146