if_tun.c revision 1.131
1 /* $NetBSD: if_tun.c,v 1.131 2016/09/07 10:24:57 ozaki-r 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 #include <sys/cdefs.h> 18 __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.131 2016/09/07 10:24:57 ozaki-r Exp $"); 19 20 #ifdef _KERNEL_OPT 21 #include "opt_inet.h" 22 #endif 23 24 #include <sys/param.h> 25 #include <sys/proc.h> 26 #include <sys/systm.h> 27 #include <sys/mbuf.h> 28 #include <sys/buf.h> 29 #include <sys/protosw.h> 30 #include <sys/socket.h> 31 #include <sys/ioctl.h> 32 #include <sys/errno.h> 33 #include <sys/syslog.h> 34 #include <sys/select.h> 35 #include <sys/poll.h> 36 #include <sys/file.h> 37 #include <sys/signalvar.h> 38 #include <sys/conf.h> 39 #include <sys/kauth.h> 40 #include <sys/mutex.h> 41 #include <sys/cpu.h> 42 #include <sys/device.h> 43 #include <sys/module.h> 44 45 #include <net/if.h> 46 #include <net/if_types.h> 47 #include <net/netisr.h> 48 #include <net/route.h> 49 50 51 #ifdef INET 52 #include <netinet/in.h> 53 #include <netinet/in_systm.h> 54 #include <netinet/in_var.h> 55 #include <netinet/ip.h> 56 #include <netinet/if_inarp.h> 57 #endif 58 59 60 #include <sys/time.h> 61 #include <net/bpf.h> 62 63 #include <net/if_tun.h> 64 65 #include "ioconf.h" 66 67 #define TUNDEBUG if (tundebug) printf 68 int tundebug = 0; 69 70 extern int ifqmaxlen; 71 72 static LIST_HEAD(, tun_softc) tun_softc_list; 73 static LIST_HEAD(, tun_softc) tunz_softc_list; 74 static kmutex_t tun_softc_lock; 75 76 static int tun_ioctl(struct ifnet *, u_long, void *); 77 static int tun_output(struct ifnet *, struct mbuf *, 78 const struct sockaddr *, const struct rtentry *rt); 79 static int tun_clone_create(struct if_clone *, int); 80 static int tun_clone_destroy(struct ifnet *); 81 82 static struct if_clone tun_cloner = 83 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 84 85 static void tunattach0(struct tun_softc *); 86 static void tun_enable(struct tun_softc *); 87 static void tun_i_softintr(void *); 88 static void tun_o_softintr(void *); 89 #ifdef ALTQ 90 static void tunstart(struct ifnet *); 91 #endif 92 static struct tun_softc *tun_find_unit(dev_t); 93 static struct tun_softc *tun_find_zunit(int); 94 95 static dev_type_open(tunopen); 96 static dev_type_close(tunclose); 97 static dev_type_read(tunread); 98 static dev_type_write(tunwrite); 99 static dev_type_ioctl(tunioctl); 100 static dev_type_poll(tunpoll); 101 static dev_type_kqfilter(tunkqfilter); 102 103 const struct cdevsw tun_cdevsw = { 104 .d_open = tunopen, 105 .d_close = tunclose, 106 .d_read = tunread, 107 .d_write = tunwrite, 108 .d_ioctl = tunioctl, 109 .d_stop = nostop, 110 .d_tty = notty, 111 .d_poll = tunpoll, 112 .d_mmap = nommap, 113 .d_kqfilter = tunkqfilter, 114 .d_discard = nodiscard, 115 .d_flag = D_OTHER 116 }; 117 118 #ifdef _MODULE 119 devmajor_t tun_bmajor = -1, tun_cmajor = -1; 120 #endif 121 122 void 123 tunattach(int unused) 124 { 125 126 /* 127 * Nothing to do here, initialization is handled by the 128 * module initialization code in tuninit() below). 129 */ 130 } 131 132 static void 133 tuninit(void) 134 { 135 136 mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NET); 137 LIST_INIT(&tun_softc_list); 138 LIST_INIT(&tunz_softc_list); 139 if_clone_attach(&tun_cloner); 140 #ifdef _MODULE 141 devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); 142 #endif 143 } 144 145 static int 146 tundetach(void) 147 { 148 int error = 0; 149 150 if (!LIST_EMPTY(&tun_softc_list) || !LIST_EMPTY(&tunz_softc_list)) 151 error = EBUSY; 152 153 #ifdef _MODULE 154 if (error == 0) 155 error = devsw_detach(NULL, &tun_cdevsw); 156 #endif 157 if (error == 0) { 158 if_clone_detach(&tun_cloner); 159 mutex_destroy(&tun_softc_lock); 160 } 161 162 return error; 163 } 164 165 /* 166 * Find driver instance from dev_t. 167 * Returns with tp locked (if found). 168 */ 169 static struct tun_softc * 170 tun_find_unit(dev_t dev) 171 { 172 struct tun_softc *tp; 173 int unit = minor(dev); 174 175 mutex_enter(&tun_softc_lock); 176 LIST_FOREACH(tp, &tun_softc_list, tun_list) 177 if (unit == tp->tun_unit) 178 break; 179 if (tp) 180 mutex_enter(&tp->tun_lock); 181 mutex_exit(&tun_softc_lock); 182 183 return (tp); 184 } 185 186 /* 187 * Find zombie driver instance by unit number. 188 * Remove tp from list and return it unlocked (if found). 189 */ 190 static struct tun_softc * 191 tun_find_zunit(int unit) 192 { 193 struct tun_softc *tp; 194 195 mutex_enter(&tun_softc_lock); 196 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 197 if (unit == tp->tun_unit) 198 break; 199 if (tp) 200 LIST_REMOVE(tp, tun_list); 201 mutex_exit(&tun_softc_lock); 202 #ifdef DIAGNOSTIC 203 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 204 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 205 #endif 206 207 return (tp); 208 } 209 210 static int 211 tun_clone_create(struct if_clone *ifc, int unit) 212 { 213 struct tun_softc *tp; 214 215 if ((tp = tun_find_zunit(unit)) == NULL) { 216 /* Allocate a new instance */ 217 tp = malloc(sizeof(*tp), M_DEVBUF, M_WAITOK|M_ZERO); 218 219 tp->tun_unit = unit; 220 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 221 selinit(&tp->tun_rsel); 222 selinit(&tp->tun_wsel); 223 } else { 224 /* Revive tunnel instance; clear ifp part */ 225 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 226 } 227 228 if_initname(&tp->tun_if, ifc->ifc_name, unit); 229 tunattach0(tp); 230 tp->tun_flags |= TUN_INITED; 231 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 232 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 233 234 mutex_enter(&tun_softc_lock); 235 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 236 mutex_exit(&tun_softc_lock); 237 238 return (0); 239 } 240 241 static void 242 tunattach0(struct tun_softc *tp) 243 { 244 struct ifnet *ifp; 245 246 ifp = &tp->tun_if; 247 ifp->if_softc = tp; 248 ifp->if_mtu = TUNMTU; 249 ifp->if_ioctl = tun_ioctl; 250 ifp->if_output = tun_output; 251 #ifdef ALTQ 252 ifp->if_start = tunstart; 253 #endif 254 ifp->if_flags = IFF_POINTOPOINT; 255 ifp->if_type = IFT_TUNNEL; 256 ifp->if_snd.ifq_maxlen = ifqmaxlen; 257 ifp->if_collisions = 0; 258 ifp->if_ierrors = 0; 259 ifp->if_oerrors = 0; 260 ifp->if_ipackets = 0; 261 ifp->if_opackets = 0; 262 ifp->if_ibytes = 0; 263 ifp->if_obytes = 0; 264 ifp->if_dlt = DLT_NULL; 265 IFQ_SET_READY(&ifp->if_snd); 266 if_attach(ifp); 267 if_alloc_sadl(ifp); 268 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 269 } 270 271 static int 272 tun_clone_destroy(struct ifnet *ifp) 273 { 274 struct tun_softc *tp = (void *)ifp; 275 int zombie = 0; 276 277 IF_PURGE(&ifp->if_snd); 278 ifp->if_flags &= ~IFF_RUNNING; 279 280 mutex_enter(&tun_softc_lock); 281 mutex_enter(&tp->tun_lock); 282 LIST_REMOVE(tp, tun_list); 283 if (tp->tun_flags & TUN_OPEN) { 284 /* Hang on to storage until last close */ 285 zombie = 1; 286 tp->tun_flags &= ~TUN_INITED; 287 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 288 } 289 mutex_exit(&tun_softc_lock); 290 291 if (tp->tun_flags & TUN_RWAIT) { 292 tp->tun_flags &= ~TUN_RWAIT; 293 wakeup((void *)tp); 294 } 295 selnotify(&tp->tun_rsel, 0, 0); 296 297 mutex_exit(&tp->tun_lock); 298 299 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 300 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 301 302 bpf_detach(ifp); 303 if_detach(ifp); 304 305 if (!zombie) { 306 seldestroy(&tp->tun_rsel); 307 seldestroy(&tp->tun_wsel); 308 softint_disestablish(tp->tun_osih); 309 softint_disestablish(tp->tun_isih); 310 mutex_destroy(&tp->tun_lock); 311 free(tp, M_DEVBUF); 312 } 313 314 return (0); 315 } 316 317 /* 318 * tunnel open - must be superuser & the device must be 319 * configured in 320 */ 321 static int 322 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 323 { 324 struct ifnet *ifp; 325 struct tun_softc *tp; 326 int error; 327 328 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 329 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 330 if (error) 331 return (error); 332 333 tp = tun_find_unit(dev); 334 335 if (tp == NULL) { 336 (void)tun_clone_create(&tun_cloner, minor(dev)); 337 tp = tun_find_unit(dev); 338 if (tp == NULL) { 339 error = ENXIO; 340 goto out_nolock; 341 } 342 } 343 344 if (tp->tun_flags & TUN_OPEN) { 345 error = EBUSY; 346 goto out; 347 } 348 349 ifp = &tp->tun_if; 350 tp->tun_flags |= TUN_OPEN; 351 TUNDEBUG("%s: open\n", ifp->if_xname); 352 out: 353 mutex_exit(&tp->tun_lock); 354 out_nolock: 355 return (error); 356 } 357 358 /* 359 * tunclose - close the device - mark i/f down & delete 360 * routing info 361 */ 362 int 363 tunclose(dev_t dev, int flag, int mode, 364 struct lwp *l) 365 { 366 struct tun_softc *tp; 367 struct ifnet *ifp; 368 369 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 370 /* interface was "destroyed" before the close */ 371 seldestroy(&tp->tun_rsel); 372 seldestroy(&tp->tun_wsel); 373 softint_disestablish(tp->tun_osih); 374 softint_disestablish(tp->tun_isih); 375 mutex_destroy(&tp->tun_lock); 376 free(tp, M_DEVBUF); 377 goto out_nolock; 378 } 379 380 if ((tp = tun_find_unit(dev)) == NULL) 381 goto out_nolock; 382 383 ifp = &tp->tun_if; 384 385 tp->tun_flags &= ~TUN_OPEN; 386 387 tp->tun_pgid = 0; 388 selnotify(&tp->tun_rsel, 0, 0); 389 390 TUNDEBUG ("%s: closed\n", ifp->if_xname); 391 mutex_exit(&tp->tun_lock); 392 393 /* 394 * junk all pending output 395 */ 396 IFQ_PURGE(&ifp->if_snd); 397 398 if (ifp->if_flags & IFF_UP) { 399 if_down(ifp); 400 if (ifp->if_flags & IFF_RUNNING) { 401 /* find internet addresses and delete routes */ 402 struct ifaddr *ifa; 403 IFADDR_READER_FOREACH(ifa, ifp) { 404 #if defined(INET) || defined(INET6) 405 if (ifa->ifa_addr->sa_family == AF_INET || 406 ifa->ifa_addr->sa_family == AF_INET6) { 407 rtinit(ifa, (int)RTM_DELETE, 408 tp->tun_flags & TUN_DSTADDR 409 ? RTF_HOST 410 : 0); 411 } 412 #endif 413 } 414 } 415 } 416 out_nolock: 417 return (0); 418 } 419 420 /* 421 * Call at splnet(). 422 */ 423 static void 424 tun_enable(struct tun_softc *tp) 425 { 426 struct ifnet *ifp = &tp->tun_if; 427 struct ifaddr *ifa; 428 429 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 430 431 mutex_enter(&tp->tun_lock); 432 ifp->if_flags |= IFF_UP | IFF_RUNNING; 433 434 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 435 IFADDR_READER_FOREACH(ifa, ifp) { 436 #ifdef INET 437 if (ifa->ifa_addr->sa_family == AF_INET) { 438 struct sockaddr_in *sin; 439 440 sin = satosin(ifa->ifa_addr); 441 if (sin && sin->sin_addr.s_addr) 442 tp->tun_flags |= TUN_IASET; 443 444 if (ifp->if_flags & IFF_POINTOPOINT) { 445 sin = satosin(ifa->ifa_dstaddr); 446 if (sin && sin->sin_addr.s_addr) 447 tp->tun_flags |= TUN_DSTADDR; 448 } 449 } 450 #endif 451 #ifdef INET6 452 if (ifa->ifa_addr->sa_family == AF_INET6) { 453 struct sockaddr_in6 *sin; 454 455 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 456 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 457 tp->tun_flags |= TUN_IASET; 458 459 if (ifp->if_flags & IFF_POINTOPOINT) { 460 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 461 if (sin && 462 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 463 tp->tun_flags |= TUN_DSTADDR; 464 } else 465 tp->tun_flags &= ~TUN_DSTADDR; 466 } 467 #endif /* INET6 */ 468 } 469 mutex_exit(&tp->tun_lock); 470 } 471 472 /* 473 * Process an ioctl request. 474 */ 475 static int 476 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 477 { 478 int error = 0, s; 479 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 480 struct ifreq *ifr = (struct ifreq *)data; 481 struct ifaddr *ifa = (struct ifaddr *)data; 482 483 s = splnet(); 484 485 switch (cmd) { 486 case SIOCINITIFADDR: 487 tun_enable(tp); 488 ifa->ifa_rtrequest = p2p_rtrequest; 489 TUNDEBUG("%s: address set\n", ifp->if_xname); 490 break; 491 case SIOCSIFBRDADDR: 492 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 493 break; 494 case SIOCSIFMTU: 495 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 496 error = EINVAL; 497 break; 498 } 499 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 500 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 501 error = 0; 502 break; 503 case SIOCADDMULTI: 504 case SIOCDELMULTI: 505 if (ifr == NULL) { 506 error = EAFNOSUPPORT; /* XXX */ 507 break; 508 } 509 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 510 #ifdef INET 511 case AF_INET: 512 break; 513 #endif 514 #ifdef INET6 515 case AF_INET6: 516 break; 517 #endif 518 default: 519 error = EAFNOSUPPORT; 520 break; 521 } 522 break; 523 default: 524 error = ifioctl_common(ifp, cmd, data); 525 } 526 527 splx(s); 528 return (error); 529 } 530 531 /* 532 * tun_output - queue packets from higher level ready to put out. 533 */ 534 static int 535 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 536 const struct rtentry *rt) 537 { 538 struct tun_softc *tp = ifp->if_softc; 539 int s; 540 int error; 541 #if defined(INET) || defined(INET6) 542 int mlen; 543 uint32_t *af; 544 #endif 545 546 s = splnet(); 547 mutex_enter(&tp->tun_lock); 548 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 549 550 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 551 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 552 tp->tun_flags); 553 error = EHOSTDOWN; 554 goto out; 555 } 556 557 /* 558 * if the queueing discipline needs packet classification, 559 * do it before prepending link headers. 560 */ 561 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 562 563 bpf_mtap_af(ifp, dst->sa_family, m0); 564 565 switch(dst->sa_family) { 566 #ifdef INET6 567 case AF_INET6: 568 #endif 569 #ifdef INET 570 case AF_INET: 571 #endif 572 #if defined(INET) || defined(INET6) 573 if (tp->tun_flags & TUN_PREPADDR) { 574 /* Simple link-layer header */ 575 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 576 if (m0 == NULL) { 577 IF_DROP(&ifp->if_snd); 578 error = ENOBUFS; 579 goto out; 580 } 581 bcopy(dst, mtod(m0, char *), dst->sa_len); 582 } 583 584 if (tp->tun_flags & TUN_IFHEAD) { 585 /* Prepend the address family */ 586 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 587 if (m0 == NULL) { 588 IF_DROP(&ifp->if_snd); 589 error = ENOBUFS; 590 goto out; 591 } 592 af = mtod(m0,uint32_t *); 593 *af = htonl(dst->sa_family); 594 } else { 595 #ifdef INET 596 if (dst->sa_family != AF_INET) 597 #endif 598 { 599 error = EAFNOSUPPORT; 600 goto out; 601 } 602 } 603 /* FALLTHROUGH */ 604 case AF_UNSPEC: 605 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 606 if (error) { 607 ifp->if_collisions++; 608 error = EAFNOSUPPORT; 609 m0 = NULL; 610 goto out; 611 } 612 mlen = m0->m_pkthdr.len; 613 ifp->if_opackets++; 614 ifp->if_obytes += mlen; 615 break; 616 #endif 617 default: 618 error = EAFNOSUPPORT; 619 goto out; 620 } 621 622 if (tp->tun_flags & TUN_RWAIT) { 623 tp->tun_flags &= ~TUN_RWAIT; 624 wakeup((void *)tp); 625 } 626 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 627 softint_schedule(tp->tun_isih); 628 629 selnotify(&tp->tun_rsel, 0, 0); 630 out: 631 mutex_exit(&tp->tun_lock); 632 splx(s); 633 634 if (error && m0) { 635 m_freem(m0); 636 } 637 return 0; 638 } 639 640 static void 641 tun_i_softintr(void *cookie) 642 { 643 struct tun_softc *tp = cookie; 644 645 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 646 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 647 NULL); 648 } 649 650 static void 651 tun_o_softintr(void *cookie) 652 { 653 struct tun_softc *tp = cookie; 654 655 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 656 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 657 NULL); 658 } 659 660 /* 661 * the cdevsw interface is now pretty minimal. 662 */ 663 int 664 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 665 { 666 struct tun_softc *tp; 667 int s, error = 0; 668 669 s = splnet(); 670 tp = tun_find_unit(dev); 671 672 /* interface was "destroyed" already */ 673 if (tp == NULL) { 674 error = ENXIO; 675 goto out_nolock; 676 } 677 678 switch (cmd) { 679 case TUNSDEBUG: 680 tundebug = *(int *)data; 681 break; 682 683 case TUNGDEBUG: 684 *(int *)data = tundebug; 685 break; 686 687 case TUNSIFMODE: 688 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 689 case IFF_POINTOPOINT: 690 case IFF_BROADCAST: 691 if (tp->tun_if.if_flags & IFF_UP) { 692 error = EBUSY; 693 goto out; 694 } 695 tp->tun_if.if_flags &= 696 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 697 tp->tun_if.if_flags |= *(int *)data; 698 break; 699 default: 700 error = EINVAL; 701 goto out; 702 } 703 break; 704 705 case TUNSLMODE: 706 if (*(int *)data) { 707 tp->tun_flags |= TUN_PREPADDR; 708 tp->tun_flags &= ~TUN_IFHEAD; 709 } else 710 tp->tun_flags &= ~TUN_PREPADDR; 711 break; 712 713 case TUNSIFHEAD: 714 if (*(int *)data) { 715 tp->tun_flags |= TUN_IFHEAD; 716 tp->tun_flags &= ~TUN_PREPADDR; 717 } else 718 tp->tun_flags &= ~TUN_IFHEAD; 719 break; 720 721 case TUNGIFHEAD: 722 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 723 break; 724 725 case FIONBIO: 726 if (*(int *)data) 727 tp->tun_flags |= TUN_NBIO; 728 else 729 tp->tun_flags &= ~TUN_NBIO; 730 break; 731 732 case FIOASYNC: 733 if (*(int *)data) 734 tp->tun_flags |= TUN_ASYNC; 735 else 736 tp->tun_flags &= ~TUN_ASYNC; 737 break; 738 739 case FIONREAD: 740 if (tp->tun_if.if_snd.ifq_head) 741 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 742 else 743 *(int *)data = 0; 744 break; 745 746 case TIOCSPGRP: 747 case FIOSETOWN: 748 error = fsetown(&tp->tun_pgid, cmd, data); 749 break; 750 751 case TIOCGPGRP: 752 case FIOGETOWN: 753 error = fgetown(tp->tun_pgid, cmd, data); 754 break; 755 756 default: 757 error = ENOTTY; 758 } 759 760 out: 761 mutex_exit(&tp->tun_lock); 762 out_nolock: 763 splx(s); 764 return (error); 765 } 766 767 /* 768 * The cdevsw read interface - reads a packet at a time, or at 769 * least as much of a packet as can be read. 770 */ 771 int 772 tunread(dev_t dev, struct uio *uio, int ioflag) 773 { 774 struct tun_softc *tp; 775 struct ifnet *ifp; 776 struct mbuf *m, *m0; 777 int error = 0, len, s, index; 778 779 s = splnet(); 780 tp = tun_find_unit(dev); 781 782 /* interface was "destroyed" already */ 783 if (tp == NULL) { 784 error = ENXIO; 785 goto out_nolock; 786 } 787 788 index = tp->tun_if.if_index; 789 ifp = &tp->tun_if; 790 791 TUNDEBUG ("%s: read\n", ifp->if_xname); 792 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 793 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 794 error = EHOSTDOWN; 795 goto out; 796 } 797 798 tp->tun_flags &= ~TUN_RWAIT; 799 800 do { 801 IFQ_DEQUEUE(&ifp->if_snd, m0); 802 if (m0 == 0) { 803 if (tp->tun_flags & TUN_NBIO) { 804 error = EWOULDBLOCK; 805 goto out; 806 } 807 tp->tun_flags |= TUN_RWAIT; 808 if (mtsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 809 "tunread", 0, &tp->tun_lock) != 0) { 810 error = EINTR; 811 goto out_nolock; 812 } else { 813 /* 814 * Maybe the interface was destroyed while 815 * we were sleeping, so let's ensure that 816 * we're looking at the same (valid) tun 817 * interface before looping. 818 */ 819 tp = tun_find_unit(dev); 820 if (tp == NULL) { 821 error = ENXIO; 822 goto out_nolock; 823 } 824 if (tp->tun_if.if_index != index) { 825 error = ENXIO; 826 goto out; 827 } 828 } 829 } 830 } while (m0 == 0); 831 832 mutex_exit(&tp->tun_lock); 833 splx(s); 834 835 /* Copy the mbuf chain */ 836 while (m0 && uio->uio_resid > 0 && error == 0) { 837 len = min(uio->uio_resid, m0->m_len); 838 if (len != 0) 839 error = uiomove(mtod(m0, void *), len, uio); 840 MFREE(m0, m); 841 m0 = m; 842 } 843 844 if (m0) { 845 TUNDEBUG("Dropping mbuf\n"); 846 m_freem(m0); 847 } 848 if (error) 849 ifp->if_ierrors++; 850 851 return (error); 852 853 out: 854 mutex_exit(&tp->tun_lock); 855 out_nolock: 856 splx(s); 857 return (error); 858 } 859 860 /* 861 * the cdevsw write interface - an atomic write is a packet - or else! 862 */ 863 int 864 tunwrite(dev_t dev, struct uio *uio, int ioflag) 865 { 866 struct tun_softc *tp; 867 struct ifnet *ifp; 868 struct mbuf *top, **mp, *m; 869 pktqueue_t *pktq; 870 struct sockaddr dst; 871 int error = 0, s, tlen, mlen; 872 uint32_t family; 873 874 s = splnet(); 875 tp = tun_find_unit(dev); 876 877 /* interface was "destroyed" already */ 878 if (tp == NULL) { 879 error = ENXIO; 880 goto out_nolock; 881 } 882 883 /* Unlock until we've got the data */ 884 mutex_exit(&tp->tun_lock); 885 splx(s); 886 887 ifp = &tp->tun_if; 888 889 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 890 891 if (tp->tun_flags & TUN_PREPADDR) { 892 if (uio->uio_resid < sizeof(dst)) { 893 error = EIO; 894 goto out0; 895 } 896 error = uiomove((void *)&dst, sizeof(dst), uio); 897 if (dst.sa_len > sizeof(dst)) { 898 /* Duh.. */ 899 char discard; 900 int n = dst.sa_len - sizeof(dst); 901 while (n--) 902 if ((error = uiomove(&discard, 1, uio)) != 0) { 903 goto out0; 904 } 905 } 906 } else if (tp->tun_flags & TUN_IFHEAD) { 907 if (uio->uio_resid < sizeof(family)){ 908 error = EIO; 909 goto out0; 910 } 911 error = uiomove((void *)&family, sizeof(family), uio); 912 dst.sa_family = ntohl(family); 913 } else { 914 #ifdef INET 915 dst.sa_family = AF_INET; 916 #endif 917 } 918 919 if (uio->uio_resid > TUNMTU) { 920 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 921 (unsigned long)uio->uio_resid); 922 error = EIO; 923 goto out0; 924 } 925 926 switch (dst.sa_family) { 927 #ifdef INET 928 case AF_INET: 929 pktq = ip_pktq; 930 break; 931 #endif 932 #ifdef INET6 933 case AF_INET6: 934 pktq = ip6_pktq; 935 break; 936 #endif 937 default: 938 error = EAFNOSUPPORT; 939 goto out0; 940 } 941 942 tlen = uio->uio_resid; 943 944 /* get a header mbuf */ 945 MGETHDR(m, M_DONTWAIT, MT_DATA); 946 if (m == NULL) { 947 error = ENOBUFS; 948 goto out0; 949 } 950 mlen = MHLEN; 951 952 top = NULL; 953 mp = ⊤ 954 while (error == 0 && uio->uio_resid > 0) { 955 m->m_len = min(mlen, uio->uio_resid); 956 error = uiomove(mtod(m, void *), m->m_len, uio); 957 *mp = m; 958 mp = &m->m_next; 959 if (error == 0 && uio->uio_resid > 0) { 960 MGET(m, M_DONTWAIT, MT_DATA); 961 if (m == NULL) { 962 error = ENOBUFS; 963 break; 964 } 965 mlen = MLEN; 966 } 967 } 968 if (error) { 969 if (top != NULL) 970 m_freem (top); 971 ifp->if_ierrors++; 972 goto out0; 973 } 974 975 top->m_pkthdr.len = tlen; 976 m_set_rcvif(top, ifp); 977 978 bpf_mtap_af(ifp, dst.sa_family, top); 979 980 s = splnet(); 981 mutex_enter(&tp->tun_lock); 982 if ((tp->tun_flags & TUN_INITED) == 0) { 983 /* Interface was destroyed */ 984 error = ENXIO; 985 goto out; 986 } 987 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 988 ifp->if_collisions++; 989 mutex_exit(&tp->tun_lock); 990 error = ENOBUFS; 991 m_freem(top); 992 goto out_nolock; 993 } 994 ifp->if_ipackets++; 995 ifp->if_ibytes += tlen; 996 out: 997 mutex_exit(&tp->tun_lock); 998 out_nolock: 999 splx(s); 1000 out0: 1001 return (error); 1002 } 1003 1004 #ifdef ALTQ 1005 /* 1006 * Start packet transmission on the interface. 1007 * when the interface queue is rate-limited by ALTQ or TBR, 1008 * if_start is needed to drain packets from the queue in order 1009 * to notify readers when outgoing packets become ready. 1010 * 1011 * Should be called at splnet. 1012 */ 1013 static void 1014 tunstart(struct ifnet *ifp) 1015 { 1016 struct tun_softc *tp = ifp->if_softc; 1017 1018 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 1019 return; 1020 1021 mutex_enter(&tp->tun_lock); 1022 if (!IF_IS_EMPTY(&ifp->if_snd)) { 1023 if (tp->tun_flags & TUN_RWAIT) { 1024 tp->tun_flags &= ~TUN_RWAIT; 1025 wakeup((void *)tp); 1026 } 1027 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 1028 softint_schedule(tp->tun_osih); 1029 1030 selnotify(&tp->tun_rsel, 0, 0); 1031 } 1032 mutex_exit(&tp->tun_lock); 1033 } 1034 #endif /* ALTQ */ 1035 /* 1036 * tunpoll - the poll interface, this is only useful on reads 1037 * really. The write detect always returns true, write never blocks 1038 * anyway, it either accepts the packet or drops it. 1039 */ 1040 int 1041 tunpoll(dev_t dev, int events, struct lwp *l) 1042 { 1043 struct tun_softc *tp; 1044 struct ifnet *ifp; 1045 int s, revents = 0; 1046 1047 s = splnet(); 1048 tp = tun_find_unit(dev); 1049 1050 /* interface was "destroyed" already */ 1051 if (tp == NULL) 1052 goto out_nolock; 1053 1054 ifp = &tp->tun_if; 1055 1056 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1057 1058 if (events & (POLLIN | POLLRDNORM)) { 1059 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1060 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1061 ifp->if_snd.ifq_len); 1062 revents |= events & (POLLIN | POLLRDNORM); 1063 } else { 1064 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1065 selrecord(l, &tp->tun_rsel); 1066 } 1067 } 1068 1069 if (events & (POLLOUT | POLLWRNORM)) 1070 revents |= events & (POLLOUT | POLLWRNORM); 1071 1072 mutex_exit(&tp->tun_lock); 1073 out_nolock: 1074 splx(s); 1075 return (revents); 1076 } 1077 1078 static void 1079 filt_tunrdetach(struct knote *kn) 1080 { 1081 struct tun_softc *tp = kn->kn_hook; 1082 int s; 1083 1084 s = splnet(); 1085 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1086 splx(s); 1087 } 1088 1089 static int 1090 filt_tunread(struct knote *kn, long hint) 1091 { 1092 struct tun_softc *tp = kn->kn_hook; 1093 struct ifnet *ifp = &tp->tun_if; 1094 struct mbuf *m; 1095 int s; 1096 1097 s = splnet(); 1098 IF_POLL(&ifp->if_snd, m); 1099 if (m == NULL) { 1100 splx(s); 1101 return (0); 1102 } 1103 1104 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1105 kn->kn_data += m->m_len; 1106 1107 splx(s); 1108 return (1); 1109 } 1110 1111 static const struct filterops tunread_filtops = 1112 { 1, NULL, filt_tunrdetach, filt_tunread }; 1113 1114 static const struct filterops tun_seltrue_filtops = 1115 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1116 1117 int 1118 tunkqfilter(dev_t dev, struct knote *kn) 1119 { 1120 struct tun_softc *tp; 1121 struct klist *klist; 1122 int rv = 0, s; 1123 1124 s = splnet(); 1125 tp = tun_find_unit(dev); 1126 if (tp == NULL) 1127 goto out_nolock; 1128 1129 switch (kn->kn_filter) { 1130 case EVFILT_READ: 1131 klist = &tp->tun_rsel.sel_klist; 1132 kn->kn_fop = &tunread_filtops; 1133 break; 1134 1135 case EVFILT_WRITE: 1136 klist = &tp->tun_rsel.sel_klist; 1137 kn->kn_fop = &tun_seltrue_filtops; 1138 break; 1139 1140 default: 1141 rv = EINVAL; 1142 goto out; 1143 } 1144 1145 kn->kn_hook = tp; 1146 1147 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1148 1149 out: 1150 mutex_exit(&tp->tun_lock); 1151 out_nolock: 1152 splx(s); 1153 return (rv); 1154 } 1155 1156 /* 1157 * Module infrastructure 1158 */ 1159 #include "if_module.h" 1160 1161 IF_MODULE(MODULE_CLASS_DRIVER, tun, "") 1162
Indexes created Tue Oct 14 11:09:46 GMT 2025