if_tun.c revision 1.164
1 /* $NetBSD: if_tun.c,v 1.164 2021/09/26 15:58:33 thorpej 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 1.164 2021/09/26 15:58:33 thorpej 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_type = IFT_TUNNEL; 260 ifp->if_snd.ifq_maxlen = ifqmaxlen; 261 ifp->if_dlt = DLT_NULL; 262 IFQ_SET_READY(&ifp->if_snd); 263 if_attach(ifp); 264 ifp->if_link_state = LINK_STATE_DOWN; 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 if_link_state_change(ifp, LINK_STATE_UP); 351 352 mutex_exit(&tp->tun_lock); 353 354 return error; 355 } 356 357 /* 358 * tunclose - close the device - mark i/f down & delete 359 * routing info 360 */ 361 int 362 tunclose(dev_t dev, int flag, int mode, 363 struct lwp *l) 364 { 365 struct tun_softc *tp; 366 struct ifnet *ifp; 367 368 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 369 /* interface was "destroyed" before the close */ 370 seldestroy(&tp->tun_rsel); 371 seldestroy(&tp->tun_wsel); 372 softint_disestablish(tp->tun_osih); 373 softint_disestablish(tp->tun_isih); 374 mutex_destroy(&tp->tun_lock); 375 kmem_free(tp, sizeof(*tp)); 376 return 0; 377 } 378 379 if ((tp = tun_find_unit(dev)) == NULL) 380 goto out_nolock; 381 382 ifp = &tp->tun_if; 383 384 tp->tun_flags &= ~TUN_OPEN; 385 386 tp->tun_pgid = 0; 387 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 388 389 TUNDEBUG ("%s: closed\n", ifp->if_xname); 390 mutex_exit(&tp->tun_lock); 391 392 /* 393 * junk all pending output 394 */ 395 IFQ_PURGE(&ifp->if_snd); 396 397 if (ifp->if_flags & IFF_UP) { 398 if_down(ifp); 399 if (ifp->if_flags & IFF_RUNNING) { 400 /* find internet addresses and delete routes */ 401 struct ifaddr *ifa; 402 IFADDR_READER_FOREACH(ifa, ifp) { 403 #if defined(INET) || defined(INET6) 404 if (ifa->ifa_addr->sa_family == AF_INET || 405 ifa->ifa_addr->sa_family == AF_INET6) { 406 rtinit(ifa, (int)RTM_DELETE, 407 tp->tun_flags & TUN_DSTADDR 408 ? RTF_HOST 409 : 0); 410 } 411 #endif 412 } 413 } 414 } 415 416 if_link_state_change(ifp, LINK_STATE_DOWN); 417 418 out_nolock: 419 return 0; 420 } 421 422 static void 423 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 424 { 425 struct ifnet *ifp = &tp->tun_if; 426 427 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 428 429 mutex_enter(&tp->tun_lock); 430 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 431 432 switch (ifa->ifa_addr->sa_family) { 433 #ifdef INET 434 case AF_INET: { 435 struct sockaddr_in *sin; 436 437 sin = satosin(ifa->ifa_addr); 438 if (sin && sin->sin_addr.s_addr) 439 tp->tun_flags |= TUN_IASET; 440 441 if (ifp->if_flags & IFF_POINTOPOINT) { 442 sin = satosin(ifa->ifa_dstaddr); 443 if (sin && sin->sin_addr.s_addr) 444 tp->tun_flags |= TUN_DSTADDR; 445 } 446 break; 447 } 448 #endif 449 #ifdef INET6 450 case AF_INET6: { 451 struct sockaddr_in6 *sin; 452 453 sin = satosin6(ifa->ifa_addr); 454 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 455 tp->tun_flags |= TUN_IASET; 456 457 if (ifp->if_flags & IFF_POINTOPOINT) { 458 sin = satosin6(ifa->ifa_dstaddr); 459 if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 460 tp->tun_flags |= TUN_DSTADDR; 461 } else 462 tp->tun_flags &= ~TUN_DSTADDR; 463 break; 464 } 465 #endif /* INET6 */ 466 default: 467 break; 468 } 469 ifp->if_flags |= IFF_UP | IFF_RUNNING; 470 mutex_exit(&tp->tun_lock); 471 } 472 473 /* 474 * Process an ioctl request. 475 */ 476 static int 477 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 478 { 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 int error = 0; 483 484 switch (cmd) { 485 case SIOCINITIFADDR: 486 tun_enable(tp, ifa); 487 ifa->ifa_rtrequest = p2p_rtrequest; 488 TUNDEBUG("%s: address set\n", ifp->if_xname); 489 break; 490 case SIOCSIFBRDADDR: 491 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 492 break; 493 case SIOCSIFMTU: 494 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 495 error = EINVAL; 496 break; 497 } 498 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 499 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 500 error = 0; 501 break; 502 case SIOCADDMULTI: 503 case SIOCDELMULTI: 504 if (ifr == NULL) { 505 error = EAFNOSUPPORT; /* XXX */ 506 break; 507 } 508 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 509 #ifdef INET 510 case AF_INET: 511 break; 512 #endif 513 #ifdef INET6 514 case AF_INET6: 515 break; 516 #endif 517 default: 518 error = EAFNOSUPPORT; 519 break; 520 } 521 break; 522 default: 523 error = ifioctl_common(ifp, cmd, data); 524 } 525 526 return error; 527 } 528 529 /* 530 * tun_output - queue packets from higher level ready to put out. 531 */ 532 static int 533 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 534 const struct rtentry *rt) 535 { 536 struct tun_softc *tp = ifp->if_softc; 537 int error; 538 #if defined(INET) || defined(INET6) 539 int mlen; 540 uint32_t *af; 541 #endif 542 543 mutex_enter(&tp->tun_lock); 544 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 545 546 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 547 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 548 tp->tun_flags); 549 error = EHOSTDOWN; 550 mutex_exit(&tp->tun_lock); 551 goto out; 552 } 553 // XXXrmind 554 mutex_exit(&tp->tun_lock); 555 556 /* 557 * if the queueing discipline needs packet classification, 558 * do it before prepending link headers. 559 */ 560 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 561 562 bpf_mtap_af(ifp, dst->sa_family, m0, BPF_D_OUT); 563 564 if ((error = pfil_run_hooks(ifp->if_pfil, &m0, ifp, PFIL_OUT)) != 0) 565 goto out; 566 if (m0 == NULL) 567 goto out; 568 569 switch(dst->sa_family) { 570 #ifdef INET6 571 case AF_INET6: 572 #endif 573 #ifdef INET 574 case AF_INET: 575 #endif 576 #if defined(INET) || defined(INET6) 577 if (tp->tun_flags & TUN_PREPADDR) { 578 /* Simple link-layer header */ 579 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 580 if (m0 == NULL) { 581 IF_DROP(&ifp->if_snd); 582 error = ENOBUFS; 583 goto out; 584 } 585 memcpy(mtod(m0, char *), dst, dst->sa_len); 586 } 587 588 if (tp->tun_flags & TUN_IFHEAD) { 589 /* Prepend the address family */ 590 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 591 if (m0 == NULL) { 592 IF_DROP(&ifp->if_snd); 593 error = ENOBUFS; 594 goto out; 595 } 596 af = mtod(m0,uint32_t *); 597 *af = htonl(dst->sa_family); 598 } else { 599 #ifdef INET 600 if (dst->sa_family != AF_INET) 601 #endif 602 { 603 error = EAFNOSUPPORT; 604 goto out; 605 } 606 } 607 /* FALLTHROUGH */ 608 case AF_UNSPEC: 609 mlen = m0->m_pkthdr.len; 610 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 611 if (error) { 612 if_statinc(ifp, if_collisions); 613 error = EAFNOSUPPORT; 614 m0 = NULL; 615 goto out; 616 } 617 if_statadd2(ifp, if_opackets, 1, if_obytes, mlen); 618 break; 619 #endif 620 default: 621 error = EAFNOSUPPORT; 622 goto out; 623 } 624 625 mutex_enter(&tp->tun_lock); 626 if (tp->tun_flags & TUN_RWAIT) { 627 tp->tun_flags &= ~TUN_RWAIT; 628 cv_broadcast(&tp->tun_cv); 629 } 630 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 631 softint_schedule(tp->tun_isih); 632 633 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 634 635 mutex_exit(&tp->tun_lock); 636 out: 637 if (error && m0) 638 m_freem(m0); 639 640 return error; 641 } 642 643 static void 644 tun_i_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_IN, POLLIN|POLLRDNORM, 650 NULL); 651 } 652 653 static void 654 tun_o_softintr(void *cookie) 655 { 656 struct tun_softc *tp = cookie; 657 658 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 659 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 660 NULL); 661 } 662 663 /* 664 * the cdevsw interface is now pretty minimal. 665 */ 666 int 667 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 668 { 669 struct tun_softc *tp; 670 int error = 0; 671 672 tp = tun_find_unit(dev); 673 674 /* interface was "destroyed" already */ 675 if (tp == NULL) { 676 return ENXIO; 677 } 678 679 switch (cmd) { 680 case TUNSDEBUG: 681 tundebug = *(int *)data; 682 break; 683 684 case TUNGDEBUG: 685 *(int *)data = tundebug; 686 break; 687 688 case TUNSIFMODE: 689 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 690 case IFF_POINTOPOINT: 691 case IFF_BROADCAST: 692 if (tp->tun_if.if_flags & IFF_UP) { 693 error = EBUSY; 694 goto out; 695 } 696 tp->tun_if.if_flags &= 697 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 698 tp->tun_if.if_flags |= *(int *)data; 699 break; 700 default: 701 error = EINVAL; 702 goto out; 703 } 704 break; 705 706 case TUNSLMODE: 707 if (*(int *)data) { 708 tp->tun_flags |= TUN_PREPADDR; 709 tp->tun_flags &= ~TUN_IFHEAD; 710 } else 711 tp->tun_flags &= ~TUN_PREPADDR; 712 break; 713 714 case TUNSIFHEAD: 715 if (*(int *)data) { 716 tp->tun_flags |= TUN_IFHEAD; 717 tp->tun_flags &= ~TUN_PREPADDR; 718 } else 719 tp->tun_flags &= ~TUN_IFHEAD; 720 break; 721 722 case TUNGIFHEAD: 723 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 724 break; 725 726 case FIONBIO: 727 if (*(int *)data) 728 tp->tun_flags |= TUN_NBIO; 729 else 730 tp->tun_flags &= ~TUN_NBIO; 731 break; 732 733 case FIOASYNC: 734 if (*(int *)data) 735 tp->tun_flags |= TUN_ASYNC; 736 else 737 tp->tun_flags &= ~TUN_ASYNC; 738 break; 739 740 case FIONREAD: 741 if (tp->tun_if.if_snd.ifq_head) 742 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 743 else 744 *(int *)data = 0; 745 break; 746 747 case TIOCSPGRP: 748 case FIOSETOWN: 749 error = fsetown(&tp->tun_pgid, cmd, data); 750 break; 751 752 case TIOCGPGRP: 753 case FIOGETOWN: 754 error = fgetown(tp->tun_pgid, cmd, data); 755 break; 756 757 default: 758 error = ENOTTY; 759 } 760 761 out: 762 mutex_exit(&tp->tun_lock); 763 764 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; 778 779 tp = tun_find_unit(dev); 780 781 /* interface was "destroyed" already */ 782 if (tp == NULL) { 783 return ENXIO; 784 } 785 786 ifp = &tp->tun_if; 787 788 TUNDEBUG ("%s: read\n", ifp->if_xname); 789 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 790 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 791 error = EHOSTDOWN; 792 goto out; 793 } 794 795 tp->tun_flags &= ~TUN_RWAIT; 796 797 do { 798 IFQ_DEQUEUE(&ifp->if_snd, m0); 799 if (m0 == 0) { 800 if (tp->tun_flags & TUN_NBIO) { 801 error = EWOULDBLOCK; 802 goto out; 803 } 804 tp->tun_flags |= TUN_RWAIT; 805 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 806 error = EINTR; 807 goto out; 808 } 809 } 810 } while (m0 == 0); 811 812 mutex_exit(&tp->tun_lock); 813 814 /* Copy the mbuf chain */ 815 while (m0 && uio->uio_resid > 0 && error == 0) { 816 len = uimin(uio->uio_resid, m0->m_len); 817 if (len != 0) 818 error = uiomove(mtod(m0, void *), len, uio); 819 m0 = m = m_free(m0); 820 } 821 822 if (m0) { 823 TUNDEBUG("Dropping mbuf\n"); 824 m_freem(m0); 825 } 826 if (error) 827 if_statinc(ifp, if_ierrors); 828 829 return error; 830 831 out: 832 mutex_exit(&tp->tun_lock); 833 834 return error; 835 } 836 837 /* 838 * the cdevsw write interface - an atomic write is a packet - or else! 839 */ 840 int 841 tunwrite(dev_t dev, struct uio *uio, int ioflag) 842 { 843 struct tun_softc *tp; 844 struct ifnet *ifp; 845 struct mbuf *top, **mp, *m; 846 pktqueue_t *pktq; 847 struct sockaddr dst; 848 int error = 0, tlen, mlen; 849 uint32_t family; 850 851 tp = tun_find_unit(dev); 852 if (tp == NULL) { 853 /* Interface was "destroyed" already. */ 854 return ENXIO; 855 } 856 857 /* Unlock until we've got the data */ 858 mutex_exit(&tp->tun_lock); 859 860 ifp = &tp->tun_if; 861 862 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 863 864 if (tp->tun_flags & TUN_PREPADDR) { 865 if (uio->uio_resid < sizeof(dst)) { 866 error = EIO; 867 goto out0; 868 } 869 error = uiomove((void *)&dst, sizeof(dst), uio); 870 if (dst.sa_len > sizeof(dst)) { 871 /* Duh.. */ 872 int n = dst.sa_len - sizeof(dst); 873 while (n--) { 874 char discard; 875 error = uiomove(&discard, 1, uio); 876 if (error) { 877 goto out0; 878 } 879 } 880 } 881 } else if (tp->tun_flags & TUN_IFHEAD) { 882 if (uio->uio_resid < sizeof(family)){ 883 error = EIO; 884 goto out0; 885 } 886 error = uiomove((void *)&family, sizeof(family), uio); 887 dst.sa_family = ntohl(family); 888 } else { 889 #ifdef INET 890 dst.sa_family = AF_INET; 891 #endif 892 } 893 894 if (uio->uio_resid == 0 || uio->uio_resid > TUNMTU) { 895 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 896 (unsigned long)uio->uio_resid); 897 error = EIO; 898 goto out0; 899 } 900 901 switch (dst.sa_family) { 902 #ifdef INET 903 case AF_INET: 904 pktq = ip_pktq; 905 break; 906 #endif 907 #ifdef INET6 908 case AF_INET6: 909 pktq = ip6_pktq; 910 break; 911 #endif 912 default: 913 error = EAFNOSUPPORT; 914 goto out0; 915 } 916 917 tlen = uio->uio_resid; 918 919 /* get a header mbuf */ 920 MGETHDR(m, M_DONTWAIT, MT_DATA); 921 if (m == NULL) { 922 return ENOBUFS; 923 } 924 mlen = MHLEN; 925 926 top = NULL; 927 mp = ⊤ 928 while (error == 0 && uio->uio_resid > 0) { 929 m->m_len = uimin(mlen, uio->uio_resid); 930 error = uiomove(mtod(m, void *), m->m_len, uio); 931 *mp = m; 932 mp = &m->m_next; 933 if (error == 0 && uio->uio_resid > 0) { 934 MGET(m, M_DONTWAIT, MT_DATA); 935 if (m == NULL) { 936 error = ENOBUFS; 937 break; 938 } 939 mlen = MLEN; 940 } 941 } 942 if (error) { 943 if (top != NULL) 944 m_freem(top); 945 if_statinc(ifp, if_ierrors); 946 goto out0; 947 } 948 949 top->m_pkthdr.len = tlen; 950 m_set_rcvif(top, ifp); 951 952 bpf_mtap_af(ifp, dst.sa_family, top, BPF_D_IN); 953 954 if ((error = pfil_run_hooks(ifp->if_pfil, &top, ifp, PFIL_IN)) != 0) 955 goto out0; 956 if (top == NULL) 957 goto out0; 958 959 mutex_enter(&tp->tun_lock); 960 if ((tp->tun_flags & TUN_INITED) == 0) { 961 /* Interface was destroyed */ 962 error = ENXIO; 963 goto out; 964 } 965 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 966 if_statinc(ifp, if_collisions); 967 mutex_exit(&tp->tun_lock); 968 error = ENOBUFS; 969 m_freem(top); 970 goto out0; 971 } 972 if_statadd2(ifp, if_ipackets, 1, if_ibytes, tlen); 973 out: 974 mutex_exit(&tp->tun_lock); 975 out0: 976 return error; 977 } 978 979 #ifdef ALTQ 980 /* 981 * Start packet transmission on the interface. 982 * when the interface queue is rate-limited by ALTQ or TBR, 983 * if_start is needed to drain packets from the queue in order 984 * to notify readers when outgoing packets become ready. 985 */ 986 static void 987 tunstart(struct ifnet *ifp) 988 { 989 struct tun_softc *tp = ifp->if_softc; 990 991 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 992 return; 993 994 mutex_enter(&tp->tun_lock); 995 if (!IF_IS_EMPTY(&ifp->if_snd)) { 996 if (tp->tun_flags & TUN_RWAIT) { 997 tp->tun_flags &= ~TUN_RWAIT; 998 cv_broadcast(&tp->tun_cv); 999 } 1000 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 1001 softint_schedule(tp->tun_osih); 1002 1003 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 1004 } 1005 mutex_exit(&tp->tun_lock); 1006 } 1007 #endif /* ALTQ */ 1008 /* 1009 * tunpoll - the poll interface, this is only useful on reads 1010 * really. The write detect always returns true, write never blocks 1011 * anyway, it either accepts the packet or drops it. 1012 */ 1013 int 1014 tunpoll(dev_t dev, int events, struct lwp *l) 1015 { 1016 struct tun_softc *tp; 1017 struct ifnet *ifp; 1018 int revents = 0; 1019 1020 tp = tun_find_unit(dev); 1021 if (tp == NULL) { 1022 /* Interface was "destroyed" already. */ 1023 return 0; 1024 } 1025 ifp = &tp->tun_if; 1026 1027 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1028 1029 if (events & (POLLIN | POLLRDNORM)) { 1030 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1031 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1032 ifp->if_snd.ifq_len); 1033 revents |= events & (POLLIN | POLLRDNORM); 1034 } else { 1035 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1036 selrecord(l, &tp->tun_rsel); 1037 } 1038 } 1039 1040 if (events & (POLLOUT | POLLWRNORM)) 1041 revents |= events & (POLLOUT | POLLWRNORM); 1042 1043 mutex_exit(&tp->tun_lock); 1044 1045 return revents; 1046 } 1047 1048 static void 1049 filt_tunrdetach(struct knote *kn) 1050 { 1051 struct tun_softc *tp = kn->kn_hook; 1052 1053 mutex_enter(&tp->tun_lock); 1054 selremove_knote(&tp->tun_rsel, kn); 1055 mutex_exit(&tp->tun_lock); 1056 } 1057 1058 static int 1059 filt_tunread(struct knote *kn, long hint) 1060 { 1061 struct tun_softc *tp = kn->kn_hook; 1062 struct ifnet *ifp = &tp->tun_if; 1063 struct mbuf *m; 1064 int ready; 1065 1066 if (hint & NOTE_SUBMIT) 1067 KASSERT(mutex_owned(&tp->tun_lock)); 1068 else 1069 mutex_enter(&tp->tun_lock); 1070 1071 IF_POLL(&ifp->if_snd, m); 1072 ready = (m != NULL); 1073 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1074 kn->kn_data += m->m_len; 1075 1076 if (hint & NOTE_SUBMIT) 1077 KASSERT(mutex_owned(&tp->tun_lock)); 1078 else 1079 mutex_exit(&tp->tun_lock); 1080 1081 return ready; 1082 } 1083 1084 static const struct filterops tunread_filtops = { 1085 .f_flags = FILTEROP_ISFD, 1086 .f_attach = NULL, 1087 .f_detach = filt_tunrdetach, 1088 .f_event = filt_tunread, 1089 }; 1090 1091 int 1092 tunkqfilter(dev_t dev, struct knote *kn) 1093 { 1094 struct tun_softc *tp; 1095 int rv = 0; 1096 1097 tp = tun_find_unit(dev); 1098 if (tp == NULL) 1099 goto out_nolock; 1100 1101 switch (kn->kn_filter) { 1102 case EVFILT_READ: 1103 kn->kn_fop = &tunread_filtops; 1104 kn->kn_hook = tp; 1105 selrecord_knote(&tp->tun_rsel, kn); 1106 break; 1107 1108 case EVFILT_WRITE: 1109 kn->kn_fop = &seltrue_filtops; 1110 break; 1111 1112 default: 1113 rv = EINVAL; 1114 goto out; 1115 } 1116 1117 out: 1118 mutex_exit(&tp->tun_lock); 1119 out_nolock: 1120 return rv; 1121 } 1122 1123 /* 1124 * Module infrastructure 1125 */ 1126 #include "if_module.h" 1127 1128 IF_MODULE(MODULE_CLASS_DRIVER, tun, NULL) 1129
Indexes created Tue Sep 23 07:09:52 GMT 2025