if_tun.c revision 1.160
1 /* $NetBSD: if_tun.c,v 1.160 2020/08/29 07:14:50 maxv 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 1.160 2020/08/29 07:14:50 maxv 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 #ifdef _MODULE 146 int error; 147 #endif 148 149 if_clone_detach(&tun_cloner); 150 #ifdef _MODULE 151 error = devsw_detach(NULL, &tun_cdevsw); 152 if (error != 0) { 153 if_clone_attach(&tun_cloner); 154 return error; 155 } 156 #endif 157 158 if (!LIST_EMPTY(&tun_softc_list) || !LIST_EMPTY(&tunz_softc_list)) { 159 #ifdef _MODULE 160 devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); 161 #endif 162 if_clone_attach(&tun_cloner); 163 return EBUSY; 164 } 165 166 mutex_destroy(&tun_softc_lock); 167 168 return 0; 169 } 170 171 /* 172 * Find driver instance from dev_t. 173 * Returns with tp locked (if found). 174 */ 175 static struct tun_softc * 176 tun_find_unit(dev_t dev) 177 { 178 struct tun_softc *tp; 179 int unit = minor(dev); 180 181 mutex_enter(&tun_softc_lock); 182 LIST_FOREACH(tp, &tun_softc_list, tun_list) 183 if (unit == tp->tun_unit) 184 break; 185 if (tp) 186 mutex_enter(&tp->tun_lock); 187 mutex_exit(&tun_softc_lock); 188 189 return tp; 190 } 191 192 /* 193 * Find zombie driver instance by unit number. 194 * Remove tp from list and return it unlocked (if found). 195 */ 196 static struct tun_softc * 197 tun_find_zunit(int unit) 198 { 199 struct tun_softc *tp; 200 201 mutex_enter(&tun_softc_lock); 202 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 203 if (unit == tp->tun_unit) 204 break; 205 if (tp) 206 LIST_REMOVE(tp, tun_list); 207 mutex_exit(&tun_softc_lock); 208 KASSERTMSG(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) == TUN_OPEN, 209 "tun%d: inconsistent flags: %x", unit, tp->tun_flags); 210 211 return tp; 212 } 213 214 static int 215 tun_clone_create(struct if_clone *ifc, int unit) 216 { 217 struct tun_softc *tp; 218 219 if ((tp = tun_find_zunit(unit)) == NULL) { 220 tp = kmem_zalloc(sizeof(*tp), KM_SLEEP); 221 222 tp->tun_unit = unit; 223 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 224 cv_init(&tp->tun_cv, "tunread"); 225 selinit(&tp->tun_rsel); 226 selinit(&tp->tun_wsel); 227 } else { 228 /* Revive tunnel instance; clear ifp part */ 229 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 230 } 231 232 if_initname(&tp->tun_if, ifc->ifc_name, unit); 233 tunattach0(tp); 234 tp->tun_flags |= TUN_INITED; 235 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 236 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 237 238 mutex_enter(&tun_softc_lock); 239 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 240 mutex_exit(&tun_softc_lock); 241 242 return 0; 243 } 244 245 static void 246 tunattach0(struct tun_softc *tp) 247 { 248 struct ifnet *ifp; 249 250 ifp = &tp->tun_if; 251 ifp->if_softc = tp; 252 ifp->if_mtu = TUNMTU; 253 ifp->if_ioctl = tun_ioctl; 254 ifp->if_output = tun_output; 255 #ifdef ALTQ 256 ifp->if_start = tunstart; 257 #endif 258 ifp->if_flags = IFF_POINTOPOINT; 259 ifp->if_extflags = IFEF_NO_LINK_STATE_CHANGE; 260 ifp->if_type = IFT_TUNNEL; 261 ifp->if_snd.ifq_maxlen = ifqmaxlen; 262 ifp->if_dlt = DLT_NULL; 263 IFQ_SET_READY(&ifp->if_snd); 264 if_attach(ifp); 265 if_alloc_sadl(ifp); 266 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 267 } 268 269 static int 270 tun_clone_destroy(struct ifnet *ifp) 271 { 272 struct tun_softc *tp = (void *)ifp; 273 bool zombie = false; 274 275 IF_PURGE(&ifp->if_snd); 276 ifp->if_flags &= ~IFF_RUNNING; 277 278 mutex_enter(&tun_softc_lock); 279 mutex_enter(&tp->tun_lock); 280 LIST_REMOVE(tp, tun_list); 281 if (tp->tun_flags & TUN_OPEN) { 282 /* Hang on to storage until last close. */ 283 tp->tun_flags &= ~TUN_INITED; 284 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 285 zombie = true; 286 } 287 mutex_exit(&tun_softc_lock); 288 289 if (tp->tun_flags & TUN_RWAIT) { 290 tp->tun_flags &= ~TUN_RWAIT; 291 cv_broadcast(&tp->tun_cv); 292 } 293 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 294 295 mutex_exit(&tp->tun_lock); 296 297 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 298 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 299 300 bpf_detach(ifp); 301 if_detach(ifp); 302 303 if (!zombie) { 304 seldestroy(&tp->tun_rsel); 305 seldestroy(&tp->tun_wsel); 306 softint_disestablish(tp->tun_osih); 307 softint_disestablish(tp->tun_isih); 308 mutex_destroy(&tp->tun_lock); 309 cv_destroy(&tp->tun_cv); 310 kmem_free(tp, sizeof(*tp)); 311 } 312 313 return 0; 314 } 315 316 /* 317 * tunnel open - must be superuser & the device must be 318 * configured in 319 */ 320 static int 321 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 322 { 323 struct ifnet *ifp; 324 struct tun_softc *tp; 325 int error; 326 327 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 328 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 329 if (error) 330 return error; 331 332 tp = tun_find_unit(dev); 333 334 if (tp == NULL) { 335 (void)tun_clone_create(&tun_cloner, minor(dev)); 336 tp = tun_find_unit(dev); 337 if (tp == NULL) { 338 return ENXIO; 339 } 340 } 341 342 if (tp->tun_flags & TUN_OPEN) { 343 mutex_exit(&tp->tun_lock); 344 return EBUSY; 345 } 346 347 ifp = &tp->tun_if; 348 tp->tun_flags |= TUN_OPEN; 349 TUNDEBUG("%s: open\n", ifp->if_xname); 350 351 mutex_exit(&tp->tun_lock); 352 353 return error; 354 } 355 356 /* 357 * tunclose - close the device - mark i/f down & delete 358 * routing info 359 */ 360 int 361 tunclose(dev_t dev, int flag, int mode, 362 struct lwp *l) 363 { 364 struct tun_softc *tp; 365 struct ifnet *ifp; 366 367 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 368 /* interface was "destroyed" before the close */ 369 seldestroy(&tp->tun_rsel); 370 seldestroy(&tp->tun_wsel); 371 softint_disestablish(tp->tun_osih); 372 softint_disestablish(tp->tun_isih); 373 mutex_destroy(&tp->tun_lock); 374 kmem_free(tp, sizeof(*tp)); 375 return 0; 376 } 377 378 if ((tp = tun_find_unit(dev)) == NULL) 379 goto out_nolock; 380 381 ifp = &tp->tun_if; 382 383 tp->tun_flags &= ~TUN_OPEN; 384 385 tp->tun_pgid = 0; 386 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 387 388 TUNDEBUG ("%s: closed\n", ifp->if_xname); 389 mutex_exit(&tp->tun_lock); 390 391 /* 392 * junk all pending output 393 */ 394 IFQ_PURGE(&ifp->if_snd); 395 396 if (ifp->if_flags & IFF_UP) { 397 if_down(ifp); 398 if (ifp->if_flags & IFF_RUNNING) { 399 /* find internet addresses and delete routes */ 400 struct ifaddr *ifa; 401 IFADDR_READER_FOREACH(ifa, ifp) { 402 #if defined(INET) || defined(INET6) 403 if (ifa->ifa_addr->sa_family == AF_INET || 404 ifa->ifa_addr->sa_family == AF_INET6) { 405 rtinit(ifa, (int)RTM_DELETE, 406 tp->tun_flags & TUN_DSTADDR 407 ? RTF_HOST 408 : 0); 409 } 410 #endif 411 } 412 } 413 } 414 out_nolock: 415 return 0; 416 } 417 418 static void 419 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 420 { 421 struct ifnet *ifp = &tp->tun_if; 422 423 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 424 425 mutex_enter(&tp->tun_lock); 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 ifp->if_flags |= IFF_UP | IFF_RUNNING; 466 mutex_exit(&tp->tun_lock); 467 } 468 469 /* 470 * Process an ioctl request. 471 */ 472 static int 473 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 474 { 475 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 476 struct ifreq *ifr = (struct ifreq *)data; 477 struct ifaddr *ifa = (struct ifaddr *)data; 478 int error = 0; 479 480 switch (cmd) { 481 case SIOCINITIFADDR: 482 tun_enable(tp, ifa); 483 ifa->ifa_rtrequest = p2p_rtrequest; 484 TUNDEBUG("%s: address set\n", ifp->if_xname); 485 break; 486 case SIOCSIFBRDADDR: 487 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 488 break; 489 case SIOCSIFMTU: 490 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 491 error = EINVAL; 492 break; 493 } 494 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 495 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 496 error = 0; 497 break; 498 case SIOCADDMULTI: 499 case SIOCDELMULTI: 500 if (ifr == NULL) { 501 error = EAFNOSUPPORT; /* XXX */ 502 break; 503 } 504 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 505 #ifdef INET 506 case AF_INET: 507 break; 508 #endif 509 #ifdef INET6 510 case AF_INET6: 511 break; 512 #endif 513 default: 514 error = EAFNOSUPPORT; 515 break; 516 } 517 break; 518 default: 519 error = ifioctl_common(ifp, cmd, data); 520 } 521 522 return error; 523 } 524 525 /* 526 * tun_output - queue packets from higher level ready to put out. 527 */ 528 static int 529 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 530 const struct rtentry *rt) 531 { 532 struct tun_softc *tp = ifp->if_softc; 533 int error; 534 #if defined(INET) || defined(INET6) 535 int mlen; 536 uint32_t *af; 537 #endif 538 539 mutex_enter(&tp->tun_lock); 540 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 541 542 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 543 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 544 tp->tun_flags); 545 error = EHOSTDOWN; 546 mutex_exit(&tp->tun_lock); 547 goto out; 548 } 549 // XXXrmind 550 mutex_exit(&tp->tun_lock); 551 552 /* 553 * if the queueing discipline needs packet classification, 554 * do it before prepending link headers. 555 */ 556 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 557 558 bpf_mtap_af(ifp, dst->sa_family, m0, BPF_D_OUT); 559 560 if ((error = pfil_run_hooks(ifp->if_pfil, &m0, ifp, PFIL_OUT)) != 0) 561 goto out; 562 if (m0 == NULL) 563 goto out; 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 memcpy(mtod(m0, char *), dst, 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 mlen = m0->m_pkthdr.len; 606 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 607 if (error) { 608 if_statinc(ifp, if_collisions); 609 error = EAFNOSUPPORT; 610 m0 = NULL; 611 goto out; 612 } 613 if_statadd2(ifp, if_opackets, 1, if_obytes, mlen); 614 break; 615 #endif 616 default: 617 error = EAFNOSUPPORT; 618 goto out; 619 } 620 621 mutex_enter(&tp->tun_lock); 622 if (tp->tun_flags & TUN_RWAIT) { 623 tp->tun_flags &= ~TUN_RWAIT; 624 cv_broadcast(&tp->tun_cv); 625 } 626 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 627 softint_schedule(tp->tun_isih); 628 629 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 630 631 mutex_exit(&tp->tun_lock); 632 out: 633 if (error && m0) 634 m_freem(m0); 635 636 return error; 637 } 638 639 static void 640 tun_i_softintr(void *cookie) 641 { 642 struct tun_softc *tp = cookie; 643 644 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 645 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 646 NULL); 647 } 648 649 static void 650 tun_o_softintr(void *cookie) 651 { 652 struct tun_softc *tp = cookie; 653 654 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 655 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 656 NULL); 657 } 658 659 /* 660 * the cdevsw interface is now pretty minimal. 661 */ 662 int 663 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 664 { 665 struct tun_softc *tp; 666 int error = 0; 667 668 tp = tun_find_unit(dev); 669 670 /* interface was "destroyed" already */ 671 if (tp == NULL) { 672 return ENXIO; 673 } 674 675 switch (cmd) { 676 case TUNSDEBUG: 677 tundebug = *(int *)data; 678 break; 679 680 case TUNGDEBUG: 681 *(int *)data = tundebug; 682 break; 683 684 case TUNSIFMODE: 685 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 686 case IFF_POINTOPOINT: 687 case IFF_BROADCAST: 688 if (tp->tun_if.if_flags & IFF_UP) { 689 error = EBUSY; 690 goto out; 691 } 692 tp->tun_if.if_flags &= 693 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 694 tp->tun_if.if_flags |= *(int *)data; 695 break; 696 default: 697 error = EINVAL; 698 goto out; 699 } 700 break; 701 702 case TUNSLMODE: 703 if (*(int *)data) { 704 tp->tun_flags |= TUN_PREPADDR; 705 tp->tun_flags &= ~TUN_IFHEAD; 706 } else 707 tp->tun_flags &= ~TUN_PREPADDR; 708 break; 709 710 case TUNSIFHEAD: 711 if (*(int *)data) { 712 tp->tun_flags |= TUN_IFHEAD; 713 tp->tun_flags &= ~TUN_PREPADDR; 714 } else 715 tp->tun_flags &= ~TUN_IFHEAD; 716 break; 717 718 case TUNGIFHEAD: 719 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 720 break; 721 722 case FIONBIO: 723 if (*(int *)data) 724 tp->tun_flags |= TUN_NBIO; 725 else 726 tp->tun_flags &= ~TUN_NBIO; 727 break; 728 729 case FIOASYNC: 730 if (*(int *)data) 731 tp->tun_flags |= TUN_ASYNC; 732 else 733 tp->tun_flags &= ~TUN_ASYNC; 734 break; 735 736 case FIONREAD: 737 if (tp->tun_if.if_snd.ifq_head) 738 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 739 else 740 *(int *)data = 0; 741 break; 742 743 case TIOCSPGRP: 744 case FIOSETOWN: 745 error = fsetown(&tp->tun_pgid, cmd, data); 746 break; 747 748 case TIOCGPGRP: 749 case FIOGETOWN: 750 error = fgetown(tp->tun_pgid, cmd, data); 751 break; 752 753 default: 754 error = ENOTTY; 755 } 756 757 out: 758 mutex_exit(&tp->tun_lock); 759 760 return error; 761 } 762 763 /* 764 * The cdevsw read interface - reads a packet at a time, or at 765 * least as much of a packet as can be read. 766 */ 767 int 768 tunread(dev_t dev, struct uio *uio, int ioflag) 769 { 770 struct tun_softc *tp; 771 struct ifnet *ifp; 772 struct mbuf *m, *m0; 773 int error = 0, len; 774 775 tp = tun_find_unit(dev); 776 777 /* interface was "destroyed" already */ 778 if (tp == NULL) { 779 return ENXIO; 780 } 781 782 ifp = &tp->tun_if; 783 784 TUNDEBUG ("%s: read\n", ifp->if_xname); 785 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 786 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 787 error = EHOSTDOWN; 788 goto out; 789 } 790 791 tp->tun_flags &= ~TUN_RWAIT; 792 793 do { 794 IFQ_DEQUEUE(&ifp->if_snd, m0); 795 if (m0 == 0) { 796 if (tp->tun_flags & TUN_NBIO) { 797 error = EWOULDBLOCK; 798 goto out; 799 } 800 tp->tun_flags |= TUN_RWAIT; 801 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 802 error = EINTR; 803 goto out; 804 } 805 } 806 } while (m0 == 0); 807 808 mutex_exit(&tp->tun_lock); 809 810 /* Copy the mbuf chain */ 811 while (m0 && uio->uio_resid > 0 && error == 0) { 812 len = uimin(uio->uio_resid, m0->m_len); 813 if (len != 0) 814 error = uiomove(mtod(m0, void *), len, uio); 815 m0 = m = m_free(m0); 816 } 817 818 if (m0) { 819 TUNDEBUG("Dropping mbuf\n"); 820 m_freem(m0); 821 } 822 if (error) 823 if_statinc(ifp, if_ierrors); 824 825 return error; 826 827 out: 828 mutex_exit(&tp->tun_lock); 829 830 return error; 831 } 832 833 /* 834 * the cdevsw write interface - an atomic write is a packet - or else! 835 */ 836 int 837 tunwrite(dev_t dev, struct uio *uio, int ioflag) 838 { 839 struct tun_softc *tp; 840 struct ifnet *ifp; 841 struct mbuf *top, **mp, *m; 842 pktqueue_t *pktq; 843 struct sockaddr dst; 844 int error = 0, tlen, mlen; 845 uint32_t family; 846 847 tp = tun_find_unit(dev); 848 if (tp == NULL) { 849 /* Interface was "destroyed" already. */ 850 return ENXIO; 851 } 852 853 /* Unlock until we've got the data */ 854 mutex_exit(&tp->tun_lock); 855 856 ifp = &tp->tun_if; 857 858 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 859 860 if (tp->tun_flags & TUN_PREPADDR) { 861 if (uio->uio_resid < sizeof(dst)) { 862 error = EIO; 863 goto out0; 864 } 865 error = uiomove((void *)&dst, sizeof(dst), uio); 866 if (dst.sa_len > sizeof(dst)) { 867 /* Duh.. */ 868 int n = dst.sa_len - sizeof(dst); 869 while (n--) { 870 char discard; 871 error = uiomove(&discard, 1, uio); 872 if (error) { 873 goto out0; 874 } 875 } 876 } 877 } else if (tp->tun_flags & TUN_IFHEAD) { 878 if (uio->uio_resid < sizeof(family)){ 879 error = EIO; 880 goto out0; 881 } 882 error = uiomove((void *)&family, sizeof(family), uio); 883 dst.sa_family = ntohl(family); 884 } else { 885 #ifdef INET 886 dst.sa_family = AF_INET; 887 #endif 888 } 889 890 if (uio->uio_resid == 0 || uio->uio_resid > TUNMTU) { 891 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 892 (unsigned long)uio->uio_resid); 893 error = EIO; 894 goto out0; 895 } 896 897 switch (dst.sa_family) { 898 #ifdef INET 899 case AF_INET: 900 pktq = ip_pktq; 901 break; 902 #endif 903 #ifdef INET6 904 case AF_INET6: 905 pktq = ip6_pktq; 906 break; 907 #endif 908 default: 909 error = EAFNOSUPPORT; 910 goto out0; 911 } 912 913 tlen = uio->uio_resid; 914 915 /* get a header mbuf */ 916 MGETHDR(m, M_DONTWAIT, MT_DATA); 917 if (m == NULL) { 918 return ENOBUFS; 919 } 920 mlen = MHLEN; 921 922 top = NULL; 923 mp = ⊤ 924 while (error == 0 && uio->uio_resid > 0) { 925 m->m_len = uimin(mlen, uio->uio_resid); 926 error = uiomove(mtod(m, void *), m->m_len, uio); 927 *mp = m; 928 mp = &m->m_next; 929 if (error == 0 && uio->uio_resid > 0) { 930 MGET(m, M_DONTWAIT, MT_DATA); 931 if (m == NULL) { 932 error = ENOBUFS; 933 break; 934 } 935 mlen = MLEN; 936 } 937 } 938 if (error) { 939 if (top != NULL) 940 m_freem(top); 941 if_statinc(ifp, if_ierrors); 942 goto out0; 943 } 944 945 top->m_pkthdr.len = tlen; 946 m_set_rcvif(top, ifp); 947 948 bpf_mtap_af(ifp, dst.sa_family, top, BPF_D_IN); 949 950 if ((error = pfil_run_hooks(ifp->if_pfil, &top, ifp, PFIL_IN)) != 0) 951 goto out0; 952 if (top == NULL) 953 goto out0; 954 955 mutex_enter(&tp->tun_lock); 956 if ((tp->tun_flags & TUN_INITED) == 0) { 957 /* Interface was destroyed */ 958 error = ENXIO; 959 goto out; 960 } 961 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 962 if_statinc(ifp, if_collisions); 963 mutex_exit(&tp->tun_lock); 964 error = ENOBUFS; 965 m_freem(top); 966 goto out0; 967 } 968 if_statadd2(ifp, if_ipackets, 1, if_ibytes, tlen); 969 out: 970 mutex_exit(&tp->tun_lock); 971 out0: 972 return error; 973 } 974 975 #ifdef ALTQ 976 /* 977 * Start packet transmission on the interface. 978 * when the interface queue is rate-limited by ALTQ or TBR, 979 * if_start is needed to drain packets from the queue in order 980 * to notify readers when outgoing packets become ready. 981 */ 982 static void 983 tunstart(struct ifnet *ifp) 984 { 985 struct tun_softc *tp = ifp->if_softc; 986 987 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 988 return; 989 990 mutex_enter(&tp->tun_lock); 991 if (!IF_IS_EMPTY(&ifp->if_snd)) { 992 if (tp->tun_flags & TUN_RWAIT) { 993 tp->tun_flags &= ~TUN_RWAIT; 994 cv_broadcast(&tp->tun_cv); 995 } 996 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 997 softint_schedule(tp->tun_osih); 998 999 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 1000 } 1001 mutex_exit(&tp->tun_lock); 1002 } 1003 #endif /* ALTQ */ 1004 /* 1005 * tunpoll - the poll interface, this is only useful on reads 1006 * really. The write detect always returns true, write never blocks 1007 * anyway, it either accepts the packet or drops it. 1008 */ 1009 int 1010 tunpoll(dev_t dev, int events, struct lwp *l) 1011 { 1012 struct tun_softc *tp; 1013 struct ifnet *ifp; 1014 int revents = 0; 1015 1016 tp = tun_find_unit(dev); 1017 if (tp == NULL) { 1018 /* Interface was "destroyed" already. */ 1019 return 0; 1020 } 1021 ifp = &tp->tun_if; 1022 1023 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1024 1025 if (events & (POLLIN | POLLRDNORM)) { 1026 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1027 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1028 ifp->if_snd.ifq_len); 1029 revents |= events & (POLLIN | POLLRDNORM); 1030 } else { 1031 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1032 selrecord(l, &tp->tun_rsel); 1033 } 1034 } 1035 1036 if (events & (POLLOUT | POLLWRNORM)) 1037 revents |= events & (POLLOUT | POLLWRNORM); 1038 1039 mutex_exit(&tp->tun_lock); 1040 1041 return revents; 1042 } 1043 1044 static void 1045 filt_tunrdetach(struct knote *kn) 1046 { 1047 struct tun_softc *tp = kn->kn_hook; 1048 1049 mutex_enter(&tp->tun_lock); 1050 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1051 mutex_exit(&tp->tun_lock); 1052 } 1053 1054 static int 1055 filt_tunread(struct knote *kn, long hint) 1056 { 1057 struct tun_softc *tp = kn->kn_hook; 1058 struct ifnet *ifp = &tp->tun_if; 1059 struct mbuf *m; 1060 int ready; 1061 1062 if (hint & NOTE_SUBMIT) 1063 KASSERT(mutex_owned(&tp->tun_lock)); 1064 else 1065 mutex_enter(&tp->tun_lock); 1066 1067 IF_POLL(&ifp->if_snd, m); 1068 ready = (m != NULL); 1069 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1070 kn->kn_data += m->m_len; 1071 1072 if (hint & NOTE_SUBMIT) 1073 KASSERT(mutex_owned(&tp->tun_lock)); 1074 else 1075 mutex_exit(&tp->tun_lock); 1076 1077 return ready; 1078 } 1079 1080 static const struct filterops tunread_filtops = { 1081 .f_isfd = 1, 1082 .f_attach = NULL, 1083 .f_detach = filt_tunrdetach, 1084 .f_event = filt_tunread, 1085 }; 1086 1087 static const struct filterops tun_seltrue_filtops = { 1088 .f_isfd = 1, 1089 .f_attach = NULL, 1090 .f_detach = filt_tunrdetach, 1091 .f_event = filt_seltrue, 1092 }; 1093 1094 int 1095 tunkqfilter(dev_t dev, struct knote *kn) 1096 { 1097 struct tun_softc *tp; 1098 struct klist *klist; 1099 int rv = 0; 1100 1101 tp = tun_find_unit(dev); 1102 if (tp == NULL) 1103 goto out_nolock; 1104 1105 switch (kn->kn_filter) { 1106 case EVFILT_READ: 1107 klist = &tp->tun_rsel.sel_klist; 1108 kn->kn_fop = &tunread_filtops; 1109 break; 1110 1111 case EVFILT_WRITE: 1112 klist = &tp->tun_rsel.sel_klist; 1113 kn->kn_fop = &tun_seltrue_filtops; 1114 break; 1115 1116 default: 1117 rv = EINVAL; 1118 goto out; 1119 } 1120 1121 kn->kn_hook = tp; 1122 1123 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1124 1125 out: 1126 mutex_exit(&tp->tun_lock); 1127 out_nolock: 1128 return rv; 1129 } 1130 1131 /* 1132 * Module infrastructure 1133 */ 1134 #include "if_module.h" 1135 1136 IF_MODULE(MODULE_CLASS_DRIVER, tun, NULL) 1137
Indexes created Tue Sep 23 14:10:03 GMT 2025