if_tun.c revision 1.139
1 /* $NetBSD: if_tun.c,v 1.139 2017/05/24 06:52:14 pgoyette 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 1.139 2017/05/24 06:52:14 pgoyette 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_type = IFT_TUNNEL; 251 ifp->if_snd.ifq_maxlen = ifqmaxlen; 252 ifp->if_collisions = 0; 253 ifp->if_ierrors = 0; 254 ifp->if_oerrors = 0; 255 ifp->if_ipackets = 0; 256 ifp->if_opackets = 0; 257 ifp->if_ibytes = 0; 258 ifp->if_obytes = 0; 259 ifp->if_dlt = DLT_NULL; 260 IFQ_SET_READY(&ifp->if_snd); 261 if_attach(ifp); 262 if_alloc_sadl(ifp); 263 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 264 } 265 266 static int 267 tun_clone_destroy(struct ifnet *ifp) 268 { 269 struct tun_softc *tp = (void *)ifp; 270 bool zombie = false; 271 272 IF_PURGE(&ifp->if_snd); 273 ifp->if_flags &= ~IFF_RUNNING; 274 275 mutex_enter(&tun_softc_lock); 276 mutex_enter(&tp->tun_lock); 277 LIST_REMOVE(tp, tun_list); 278 if (tp->tun_flags & TUN_OPEN) { 279 /* Hang on to storage until last close. */ 280 tp->tun_flags &= ~TUN_INITED; 281 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 282 zombie = true; 283 } 284 mutex_exit(&tun_softc_lock); 285 286 if (tp->tun_flags & TUN_RWAIT) { 287 tp->tun_flags &= ~TUN_RWAIT; 288 cv_broadcast(&tp->tun_cv); 289 } 290 selnotify(&tp->tun_rsel, 0, 0); 291 292 mutex_exit(&tp->tun_lock); 293 294 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 295 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 296 297 bpf_detach(ifp); 298 if_detach(ifp); 299 300 if (!zombie) { 301 seldestroy(&tp->tun_rsel); 302 seldestroy(&tp->tun_wsel); 303 softint_disestablish(tp->tun_osih); 304 softint_disestablish(tp->tun_isih); 305 mutex_destroy(&tp->tun_lock); 306 cv_destroy(&tp->tun_cv); 307 kmem_free(tp, sizeof(*tp)); 308 } 309 310 return 0; 311 } 312 313 /* 314 * tunnel open - must be superuser & the device must be 315 * configured in 316 */ 317 static int 318 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 319 { 320 struct ifnet *ifp; 321 struct tun_softc *tp; 322 int error; 323 324 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 325 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 326 if (error) 327 return error; 328 329 tp = tun_find_unit(dev); 330 331 if (tp == NULL) { 332 (void)tun_clone_create(&tun_cloner, minor(dev)); 333 tp = tun_find_unit(dev); 334 if (tp == NULL) { 335 return ENXIO; 336 } 337 } 338 339 if (tp->tun_flags & TUN_OPEN) { 340 mutex_exit(&tp->tun_lock); 341 return EBUSY; 342 } 343 344 ifp = &tp->tun_if; 345 tp->tun_flags |= TUN_OPEN; 346 TUNDEBUG("%s: open\n", ifp->if_xname); 347 348 mutex_exit(&tp->tun_lock); 349 350 return error; 351 } 352 353 /* 354 * tunclose - close the device - mark i/f down & delete 355 * routing info 356 */ 357 int 358 tunclose(dev_t dev, int flag, int mode, 359 struct lwp *l) 360 { 361 struct tun_softc *tp; 362 struct ifnet *ifp; 363 364 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 365 /* interface was "destroyed" before the close */ 366 seldestroy(&tp->tun_rsel); 367 seldestroy(&tp->tun_wsel); 368 softint_disestablish(tp->tun_osih); 369 softint_disestablish(tp->tun_isih); 370 mutex_destroy(&tp->tun_lock); 371 kmem_free(tp, sizeof(*tp)); 372 return 0; 373 } 374 375 if ((tp = tun_find_unit(dev)) == NULL) 376 goto out_nolock; 377 378 ifp = &tp->tun_if; 379 380 tp->tun_flags &= ~TUN_OPEN; 381 382 tp->tun_pgid = 0; 383 selnotify(&tp->tun_rsel, 0, 0); 384 385 TUNDEBUG ("%s: closed\n", ifp->if_xname); 386 mutex_exit(&tp->tun_lock); 387 388 /* 389 * junk all pending output 390 */ 391 IFQ_PURGE(&ifp->if_snd); 392 393 if (ifp->if_flags & IFF_UP) { 394 if_down(ifp); 395 if (ifp->if_flags & IFF_RUNNING) { 396 /* find internet addresses and delete routes */ 397 struct ifaddr *ifa; 398 IFADDR_READER_FOREACH(ifa, ifp) { 399 #if defined(INET) || defined(INET6) 400 if (ifa->ifa_addr->sa_family == AF_INET || 401 ifa->ifa_addr->sa_family == AF_INET6) { 402 rtinit(ifa, (int)RTM_DELETE, 403 tp->tun_flags & TUN_DSTADDR 404 ? RTF_HOST 405 : 0); 406 } 407 #endif 408 } 409 } 410 } 411 out_nolock: 412 return 0; 413 } 414 415 static void 416 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 417 { 418 struct ifnet *ifp = &tp->tun_if; 419 420 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 421 422 mutex_enter(&tp->tun_lock); 423 ifp->if_flags |= IFF_UP | IFF_RUNNING; 424 425 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 426 427 switch (ifa->ifa_addr->sa_family) { 428 #ifdef INET 429 case AF_INET: { 430 struct sockaddr_in *sin; 431 432 sin = satosin(ifa->ifa_addr); 433 if (sin && sin->sin_addr.s_addr) 434 tp->tun_flags |= TUN_IASET; 435 436 if (ifp->if_flags & IFF_POINTOPOINT) { 437 sin = satosin(ifa->ifa_dstaddr); 438 if (sin && sin->sin_addr.s_addr) 439 tp->tun_flags |= TUN_DSTADDR; 440 } 441 break; 442 } 443 #endif 444 #ifdef INET6 445 case AF_INET6: { 446 struct sockaddr_in6 *sin; 447 448 sin = satosin6(ifa->ifa_addr); 449 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 450 tp->tun_flags |= TUN_IASET; 451 452 if (ifp->if_flags & IFF_POINTOPOINT) { 453 sin = satosin6(ifa->ifa_dstaddr); 454 if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 455 tp->tun_flags |= TUN_DSTADDR; 456 } else 457 tp->tun_flags &= ~TUN_DSTADDR; 458 break; 459 } 460 #endif /* INET6 */ 461 default: 462 break; 463 } 464 mutex_exit(&tp->tun_lock); 465 } 466 467 /* 468 * Process an ioctl request. 469 */ 470 static int 471 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 472 { 473 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 474 struct ifreq *ifr = (struct ifreq *)data; 475 struct ifaddr *ifa = (struct ifaddr *)data; 476 int error = 0; 477 478 switch (cmd) { 479 case SIOCINITIFADDR: 480 tun_enable(tp, ifa); 481 ifa->ifa_rtrequest = p2p_rtrequest; 482 TUNDEBUG("%s: address set\n", ifp->if_xname); 483 break; 484 case SIOCSIFBRDADDR: 485 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 486 break; 487 case SIOCSIFMTU: 488 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 489 error = EINVAL; 490 break; 491 } 492 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 493 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 494 error = 0; 495 break; 496 case SIOCADDMULTI: 497 case SIOCDELMULTI: 498 if (ifr == NULL) { 499 error = EAFNOSUPPORT; /* XXX */ 500 break; 501 } 502 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 503 #ifdef INET 504 case AF_INET: 505 break; 506 #endif 507 #ifdef INET6 508 case AF_INET6: 509 break; 510 #endif 511 default: 512 error = EAFNOSUPPORT; 513 break; 514 } 515 break; 516 default: 517 error = ifioctl_common(ifp, cmd, data); 518 } 519 520 return error; 521 } 522 523 /* 524 * tun_output - queue packets from higher level ready to put out. 525 */ 526 static int 527 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 528 const struct rtentry *rt) 529 { 530 struct tun_softc *tp = ifp->if_softc; 531 int error; 532 #if defined(INET) || defined(INET6) 533 int mlen; 534 uint32_t *af; 535 #endif 536 537 mutex_enter(&tp->tun_lock); 538 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 539 540 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 541 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 542 tp->tun_flags); 543 error = EHOSTDOWN; 544 mutex_exit(&tp->tun_lock); 545 goto out; 546 } 547 // XXXrmind 548 mutex_exit(&tp->tun_lock); 549 550 /* 551 * if the queueing discipline needs packet classification, 552 * do it before prepending link headers. 553 */ 554 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 555 556 bpf_mtap_af(ifp, dst->sa_family, m0); 557 558 switch(dst->sa_family) { 559 #ifdef INET6 560 case AF_INET6: 561 #endif 562 #ifdef INET 563 case AF_INET: 564 #endif 565 #if defined(INET) || defined(INET6) 566 if (tp->tun_flags & TUN_PREPADDR) { 567 /* Simple link-layer header */ 568 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 569 if (m0 == NULL) { 570 IF_DROP(&ifp->if_snd); 571 error = ENOBUFS; 572 goto out; 573 } 574 memcpy(mtod(m0, char *), dst, dst->sa_len); 575 } 576 577 if (tp->tun_flags & TUN_IFHEAD) { 578 /* Prepend the address family */ 579 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 580 if (m0 == NULL) { 581 IF_DROP(&ifp->if_snd); 582 error = ENOBUFS; 583 goto out; 584 } 585 af = mtod(m0,uint32_t *); 586 *af = htonl(dst->sa_family); 587 } else { 588 #ifdef INET 589 if (dst->sa_family != AF_INET) 590 #endif 591 { 592 error = EAFNOSUPPORT; 593 goto out; 594 } 595 } 596 /* FALLTHROUGH */ 597 case AF_UNSPEC: 598 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 599 if (error) { 600 ifp->if_collisions++; 601 error = EAFNOSUPPORT; 602 m0 = NULL; 603 goto out; 604 } 605 mlen = m0->m_pkthdr.len; 606 ifp->if_opackets++; 607 ifp->if_obytes += mlen; 608 break; 609 #endif 610 default: 611 error = EAFNOSUPPORT; 612 goto out; 613 } 614 615 mutex_enter(&tp->tun_lock); 616 if (tp->tun_flags & TUN_RWAIT) { 617 tp->tun_flags &= ~TUN_RWAIT; 618 cv_broadcast(&tp->tun_cv); 619 } 620 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 621 softint_schedule(tp->tun_isih); 622 623 selnotify(&tp->tun_rsel, 0, 0); 624 625 mutex_exit(&tp->tun_lock); 626 out: 627 if (error && m0) { 628 m_freem(m0); 629 } 630 return 0; 631 } 632 633 static void 634 tun_i_softintr(void *cookie) 635 { 636 struct tun_softc *tp = cookie; 637 638 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 639 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 640 NULL); 641 } 642 643 static void 644 tun_o_softintr(void *cookie) 645 { 646 struct tun_softc *tp = cookie; 647 648 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 649 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 650 NULL); 651 } 652 653 /* 654 * the cdevsw interface is now pretty minimal. 655 */ 656 int 657 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 658 { 659 struct tun_softc *tp; 660 int error = 0; 661 662 tp = tun_find_unit(dev); 663 664 /* interface was "destroyed" already */ 665 if (tp == NULL) { 666 return ENXIO; 667 } 668 669 switch (cmd) { 670 case TUNSDEBUG: 671 tundebug = *(int *)data; 672 break; 673 674 case TUNGDEBUG: 675 *(int *)data = tundebug; 676 break; 677 678 case TUNSIFMODE: 679 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 680 case IFF_POINTOPOINT: 681 case IFF_BROADCAST: 682 if (tp->tun_if.if_flags & IFF_UP) { 683 error = EBUSY; 684 goto out; 685 } 686 tp->tun_if.if_flags &= 687 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 688 tp->tun_if.if_flags |= *(int *)data; 689 break; 690 default: 691 error = EINVAL; 692 goto out; 693 } 694 break; 695 696 case TUNSLMODE: 697 if (*(int *)data) { 698 tp->tun_flags |= TUN_PREPADDR; 699 tp->tun_flags &= ~TUN_IFHEAD; 700 } else 701 tp->tun_flags &= ~TUN_PREPADDR; 702 break; 703 704 case TUNSIFHEAD: 705 if (*(int *)data) { 706 tp->tun_flags |= TUN_IFHEAD; 707 tp->tun_flags &= ~TUN_PREPADDR; 708 } else 709 tp->tun_flags &= ~TUN_IFHEAD; 710 break; 711 712 case TUNGIFHEAD: 713 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 714 break; 715 716 case FIONBIO: 717 if (*(int *)data) 718 tp->tun_flags |= TUN_NBIO; 719 else 720 tp->tun_flags &= ~TUN_NBIO; 721 break; 722 723 case FIOASYNC: 724 if (*(int *)data) 725 tp->tun_flags |= TUN_ASYNC; 726 else 727 tp->tun_flags &= ~TUN_ASYNC; 728 break; 729 730 case FIONREAD: 731 if (tp->tun_if.if_snd.ifq_head) 732 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 733 else 734 *(int *)data = 0; 735 break; 736 737 case TIOCSPGRP: 738 case FIOSETOWN: 739 error = fsetown(&tp->tun_pgid, cmd, data); 740 break; 741 742 case TIOCGPGRP: 743 case FIOGETOWN: 744 error = fgetown(tp->tun_pgid, cmd, data); 745 break; 746 747 default: 748 error = ENOTTY; 749 } 750 751 out: 752 mutex_exit(&tp->tun_lock); 753 754 return error; 755 } 756 757 /* 758 * The cdevsw read interface - reads a packet at a time, or at 759 * least as much of a packet as can be read. 760 */ 761 int 762 tunread(dev_t dev, struct uio *uio, int ioflag) 763 { 764 struct tun_softc *tp; 765 struct ifnet *ifp; 766 struct mbuf *m, *m0; 767 int error = 0, len; 768 769 tp = tun_find_unit(dev); 770 771 /* interface was "destroyed" already */ 772 if (tp == NULL) { 773 return ENXIO; 774 } 775 776 ifp = &tp->tun_if; 777 778 TUNDEBUG ("%s: read\n", ifp->if_xname); 779 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 780 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 781 error = EHOSTDOWN; 782 goto out; 783 } 784 785 tp->tun_flags &= ~TUN_RWAIT; 786 787 do { 788 IFQ_DEQUEUE(&ifp->if_snd, m0); 789 if (m0 == 0) { 790 if (tp->tun_flags & TUN_NBIO) { 791 error = EWOULDBLOCK; 792 goto out; 793 } 794 tp->tun_flags |= TUN_RWAIT; 795 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 796 error = EINTR; 797 goto out; 798 } 799 } 800 } while (m0 == 0); 801 802 mutex_exit(&tp->tun_lock); 803 804 /* Copy the mbuf chain */ 805 while (m0 && uio->uio_resid > 0 && error == 0) { 806 len = min(uio->uio_resid, m0->m_len); 807 if (len != 0) 808 error = uiomove(mtod(m0, void *), len, uio); 809 m0 = m = m_free(m0); 810 } 811 812 if (m0) { 813 TUNDEBUG("Dropping mbuf\n"); 814 m_freem(m0); 815 } 816 if (error) 817 ifp->if_ierrors++; 818 819 return error; 820 821 out: 822 mutex_exit(&tp->tun_lock); 823 824 return error; 825 } 826 827 /* 828 * the cdevsw write interface - an atomic write is a packet - or else! 829 */ 830 int 831 tunwrite(dev_t dev, struct uio *uio, int ioflag) 832 { 833 struct tun_softc *tp; 834 struct ifnet *ifp; 835 struct mbuf *top, **mp, *m; 836 pktqueue_t *pktq; 837 struct sockaddr dst; 838 int error = 0, tlen, mlen; 839 uint32_t family; 840 841 tp = tun_find_unit(dev); 842 if (tp == NULL) { 843 /* Interface was "destroyed" already. */ 844 return ENXIO; 845 } 846 847 /* Unlock until we've got the data */ 848 mutex_exit(&tp->tun_lock); 849 850 ifp = &tp->tun_if; 851 852 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 853 854 if (tp->tun_flags & TUN_PREPADDR) { 855 if (uio->uio_resid < sizeof(dst)) { 856 error = EIO; 857 goto out0; 858 } 859 error = uiomove((void *)&dst, sizeof(dst), uio); 860 if (dst.sa_len > sizeof(dst)) { 861 /* Duh.. */ 862 int n = dst.sa_len - sizeof(dst); 863 while (n--) { 864 char discard; 865 error = uiomove(&discard, 1, uio); 866 if (error) { 867 goto out0; 868 } 869 } 870 } 871 } else if (tp->tun_flags & TUN_IFHEAD) { 872 if (uio->uio_resid < sizeof(family)){ 873 error = EIO; 874 goto out0; 875 } 876 error = uiomove((void *)&family, sizeof(family), uio); 877 dst.sa_family = ntohl(family); 878 } else { 879 #ifdef INET 880 dst.sa_family = AF_INET; 881 #endif 882 } 883 884 if (uio->uio_resid > TUNMTU) { 885 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 886 (unsigned long)uio->uio_resid); 887 error = EIO; 888 goto out0; 889 } 890 891 switch (dst.sa_family) { 892 #ifdef INET 893 case AF_INET: 894 pktq = ip_pktq; 895 break; 896 #endif 897 #ifdef INET6 898 case AF_INET6: 899 pktq = ip6_pktq; 900 break; 901 #endif 902 default: 903 error = EAFNOSUPPORT; 904 goto out0; 905 } 906 907 tlen = uio->uio_resid; 908 909 /* get a header mbuf */ 910 MGETHDR(m, M_DONTWAIT, MT_DATA); 911 if (m == NULL) { 912 return ENOBUFS; 913 } 914 mlen = MHLEN; 915 916 top = NULL; 917 mp = ⊤ 918 while (error == 0 && uio->uio_resid > 0) { 919 m->m_len = min(mlen, uio->uio_resid); 920 error = uiomove(mtod(m, void *), m->m_len, uio); 921 *mp = m; 922 mp = &m->m_next; 923 if (error == 0 && uio->uio_resid > 0) { 924 MGET(m, M_DONTWAIT, MT_DATA); 925 if (m == NULL) { 926 error = ENOBUFS; 927 break; 928 } 929 mlen = MLEN; 930 } 931 } 932 if (error) { 933 if (top != NULL) 934 m_freem(top); 935 ifp->if_ierrors++; 936 goto out0; 937 } 938 939 top->m_pkthdr.len = tlen; 940 m_set_rcvif(top, ifp); 941 942 bpf_mtap_af(ifp, dst.sa_family, top); 943 944 mutex_enter(&tp->tun_lock); 945 if ((tp->tun_flags & TUN_INITED) == 0) { 946 /* Interface was destroyed */ 947 error = ENXIO; 948 goto out; 949 } 950 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 951 ifp->if_collisions++; 952 mutex_exit(&tp->tun_lock); 953 error = ENOBUFS; 954 m_freem(top); 955 goto out0; 956 } 957 ifp->if_ipackets++; 958 ifp->if_ibytes += tlen; 959 out: 960 mutex_exit(&tp->tun_lock); 961 out0: 962 return error; 963 } 964 965 #ifdef ALTQ 966 /* 967 * Start packet transmission on the interface. 968 * when the interface queue is rate-limited by ALTQ or TBR, 969 * if_start is needed to drain packets from the queue in order 970 * to notify readers when outgoing packets become ready. 971 */ 972 static void 973 tunstart(struct ifnet *ifp) 974 { 975 struct tun_softc *tp = ifp->if_softc; 976 977 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 978 return; 979 980 mutex_enter(&tp->tun_lock); 981 if (!IF_IS_EMPTY(&ifp->if_snd)) { 982 if (tp->tun_flags & TUN_RWAIT) { 983 tp->tun_flags &= ~TUN_RWAIT; 984 cv_broadcast(&tp->tun_cv); 985 } 986 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 987 softint_schedule(tp->tun_osih); 988 989 selnotify(&tp->tun_rsel, 0, 0); 990 } 991 mutex_exit(&tp->tun_lock); 992 } 993 #endif /* ALTQ */ 994 /* 995 * tunpoll - the poll interface, this is only useful on reads 996 * really. The write detect always returns true, write never blocks 997 * anyway, it either accepts the packet or drops it. 998 */ 999 int 1000 tunpoll(dev_t dev, int events, struct lwp *l) 1001 { 1002 struct tun_softc *tp; 1003 struct ifnet *ifp; 1004 int revents = 0; 1005 1006 tp = tun_find_unit(dev); 1007 if (tp == NULL) { 1008 /* Interface was "destroyed" already. */ 1009 return 0; 1010 } 1011 ifp = &tp->tun_if; 1012 1013 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1014 1015 if (events & (POLLIN | POLLRDNORM)) { 1016 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1017 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1018 ifp->if_snd.ifq_len); 1019 revents |= events & (POLLIN | POLLRDNORM); 1020 } else { 1021 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1022 selrecord(l, &tp->tun_rsel); 1023 } 1024 } 1025 1026 if (events & (POLLOUT | POLLWRNORM)) 1027 revents |= events & (POLLOUT | POLLWRNORM); 1028 1029 mutex_exit(&tp->tun_lock); 1030 1031 return revents; 1032 } 1033 1034 static void 1035 filt_tunrdetach(struct knote *kn) 1036 { 1037 struct tun_softc *tp = kn->kn_hook; 1038 1039 mutex_enter(&tp->tun_lock); 1040 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1041 mutex_exit(&tp->tun_lock); 1042 } 1043 1044 static int 1045 filt_tunread(struct knote *kn, long hint) 1046 { 1047 struct tun_softc *tp = kn->kn_hook; 1048 struct ifnet *ifp = &tp->tun_if; 1049 struct mbuf *m; 1050 1051 mutex_enter(&tp->tun_lock); 1052 IF_POLL(&ifp->if_snd, m); 1053 if (m == NULL) { 1054 mutex_exit(&tp->tun_lock); 1055 return 0; 1056 } 1057 1058 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1059 kn->kn_data += m->m_len; 1060 1061 mutex_exit(&tp->tun_lock); 1062 1063 return 1; 1064 } 1065 1066 static const struct filterops tunread_filtops = 1067 { 1, NULL, filt_tunrdetach, filt_tunread }; 1068 1069 static const struct filterops tun_seltrue_filtops = 1070 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1071 1072 int 1073 tunkqfilter(dev_t dev, struct knote *kn) 1074 { 1075 struct tun_softc *tp; 1076 struct klist *klist; 1077 int rv = 0; 1078 1079 tp = tun_find_unit(dev); 1080 if (tp == NULL) 1081 goto out_nolock; 1082 1083 switch (kn->kn_filter) { 1084 case EVFILT_READ: 1085 klist = &tp->tun_rsel.sel_klist; 1086 kn->kn_fop = &tunread_filtops; 1087 break; 1088 1089 case EVFILT_WRITE: 1090 klist = &tp->tun_rsel.sel_klist; 1091 kn->kn_fop = &tun_seltrue_filtops; 1092 break; 1093 1094 default: 1095 rv = EINVAL; 1096 goto out; 1097 } 1098 1099 kn->kn_hook = tp; 1100 1101 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1102 1103 out: 1104 mutex_exit(&tp->tun_lock); 1105 out_nolock: 1106 return rv; 1107 } 1108 1109 /* 1110 * Module infrastructure 1111 */ 1112 #include "if_module.h" 1113 1114 IF_MODULE(MODULE_CLASS_DRIVER, tun, "") 1115
Indexes created Thu Sep 25 15:09:46 GMT 2025