if_tun.c revision 1.157
1 /* $NetBSD: if_tun.c,v 1.157 2019/12/13 14:13:55 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 1.157 2019/12/13 14:13:55 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_collisions = 0; 263 ifp->if_ierrors = 0; 264 ifp->if_oerrors = 0; 265 ifp->if_ipackets = 0; 266 ifp->if_opackets = 0; 267 ifp->if_ibytes = 0; 268 ifp->if_obytes = 0; 269 ifp->if_dlt = DLT_NULL; 270 IFQ_SET_READY(&ifp->if_snd); 271 if_attach(ifp); 272 if_alloc_sadl(ifp); 273 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 274 } 275 276 static int 277 tun_clone_destroy(struct ifnet *ifp) 278 { 279 struct tun_softc *tp = (void *)ifp; 280 bool zombie = false; 281 282 IF_PURGE(&ifp->if_snd); 283 ifp->if_flags &= ~IFF_RUNNING; 284 285 mutex_enter(&tun_softc_lock); 286 mutex_enter(&tp->tun_lock); 287 LIST_REMOVE(tp, tun_list); 288 if (tp->tun_flags & TUN_OPEN) { 289 /* Hang on to storage until last close. */ 290 tp->tun_flags &= ~TUN_INITED; 291 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 292 zombie = true; 293 } 294 mutex_exit(&tun_softc_lock); 295 296 if (tp->tun_flags & TUN_RWAIT) { 297 tp->tun_flags &= ~TUN_RWAIT; 298 cv_broadcast(&tp->tun_cv); 299 } 300 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 301 302 mutex_exit(&tp->tun_lock); 303 304 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 305 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 306 307 bpf_detach(ifp); 308 if_detach(ifp); 309 310 if (!zombie) { 311 seldestroy(&tp->tun_rsel); 312 seldestroy(&tp->tun_wsel); 313 softint_disestablish(tp->tun_osih); 314 softint_disestablish(tp->tun_isih); 315 mutex_destroy(&tp->tun_lock); 316 cv_destroy(&tp->tun_cv); 317 kmem_free(tp, sizeof(*tp)); 318 } 319 320 return 0; 321 } 322 323 /* 324 * tunnel open - must be superuser & the device must be 325 * configured in 326 */ 327 static int 328 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 329 { 330 struct ifnet *ifp; 331 struct tun_softc *tp; 332 int error; 333 334 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 335 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 336 if (error) 337 return error; 338 339 tp = tun_find_unit(dev); 340 341 if (tp == NULL) { 342 (void)tun_clone_create(&tun_cloner, minor(dev)); 343 tp = tun_find_unit(dev); 344 if (tp == NULL) { 345 return ENXIO; 346 } 347 } 348 349 if (tp->tun_flags & TUN_OPEN) { 350 mutex_exit(&tp->tun_lock); 351 return EBUSY; 352 } 353 354 ifp = &tp->tun_if; 355 tp->tun_flags |= TUN_OPEN; 356 TUNDEBUG("%s: open\n", ifp->if_xname); 357 358 mutex_exit(&tp->tun_lock); 359 360 return error; 361 } 362 363 /* 364 * tunclose - close the device - mark i/f down & delete 365 * routing info 366 */ 367 int 368 tunclose(dev_t dev, int flag, int mode, 369 struct lwp *l) 370 { 371 struct tun_softc *tp; 372 struct ifnet *ifp; 373 374 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 375 /* interface was "destroyed" before the close */ 376 seldestroy(&tp->tun_rsel); 377 seldestroy(&tp->tun_wsel); 378 softint_disestablish(tp->tun_osih); 379 softint_disestablish(tp->tun_isih); 380 mutex_destroy(&tp->tun_lock); 381 kmem_free(tp, sizeof(*tp)); 382 return 0; 383 } 384 385 if ((tp = tun_find_unit(dev)) == NULL) 386 goto out_nolock; 387 388 ifp = &tp->tun_if; 389 390 tp->tun_flags &= ~TUN_OPEN; 391 392 tp->tun_pgid = 0; 393 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 394 395 TUNDEBUG ("%s: closed\n", ifp->if_xname); 396 mutex_exit(&tp->tun_lock); 397 398 /* 399 * junk all pending output 400 */ 401 IFQ_PURGE(&ifp->if_snd); 402 403 if (ifp->if_flags & IFF_UP) { 404 if_down(ifp); 405 if (ifp->if_flags & IFF_RUNNING) { 406 /* find internet addresses and delete routes */ 407 struct ifaddr *ifa; 408 IFADDR_READER_FOREACH(ifa, ifp) { 409 #if defined(INET) || defined(INET6) 410 if (ifa->ifa_addr->sa_family == AF_INET || 411 ifa->ifa_addr->sa_family == AF_INET6) { 412 rtinit(ifa, (int)RTM_DELETE, 413 tp->tun_flags & TUN_DSTADDR 414 ? RTF_HOST 415 : 0); 416 } 417 #endif 418 } 419 } 420 } 421 out_nolock: 422 return 0; 423 } 424 425 static void 426 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 427 { 428 struct ifnet *ifp = &tp->tun_if; 429 430 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 431 432 mutex_enter(&tp->tun_lock); 433 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 434 435 switch (ifa->ifa_addr->sa_family) { 436 #ifdef INET 437 case 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 break; 450 } 451 #endif 452 #ifdef INET6 453 case AF_INET6: { 454 struct sockaddr_in6 *sin; 455 456 sin = satosin6(ifa->ifa_addr); 457 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 458 tp->tun_flags |= TUN_IASET; 459 460 if (ifp->if_flags & IFF_POINTOPOINT) { 461 sin = satosin6(ifa->ifa_dstaddr); 462 if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 463 tp->tun_flags |= TUN_DSTADDR; 464 } else 465 tp->tun_flags &= ~TUN_DSTADDR; 466 break; 467 } 468 #endif /* INET6 */ 469 default: 470 break; 471 } 472 ifp->if_flags |= IFF_UP | IFF_RUNNING; 473 mutex_exit(&tp->tun_lock); 474 } 475 476 /* 477 * Process an ioctl request. 478 */ 479 static int 480 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 481 { 482 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 483 struct ifreq *ifr = (struct ifreq *)data; 484 struct ifaddr *ifa = (struct ifaddr *)data; 485 int error = 0; 486 487 switch (cmd) { 488 case SIOCINITIFADDR: 489 tun_enable(tp, ifa); 490 ifa->ifa_rtrequest = p2p_rtrequest; 491 TUNDEBUG("%s: address set\n", ifp->if_xname); 492 break; 493 case SIOCSIFBRDADDR: 494 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 495 break; 496 case SIOCSIFMTU: 497 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 498 error = EINVAL; 499 break; 500 } 501 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 502 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 503 error = 0; 504 break; 505 case SIOCADDMULTI: 506 case SIOCDELMULTI: 507 if (ifr == NULL) { 508 error = EAFNOSUPPORT; /* XXX */ 509 break; 510 } 511 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 512 #ifdef INET 513 case AF_INET: 514 break; 515 #endif 516 #ifdef INET6 517 case AF_INET6: 518 break; 519 #endif 520 default: 521 error = EAFNOSUPPORT; 522 break; 523 } 524 break; 525 default: 526 error = ifioctl_common(ifp, cmd, data); 527 } 528 529 return error; 530 } 531 532 /* 533 * tun_output - queue packets from higher level ready to put out. 534 */ 535 static int 536 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 537 const struct rtentry *rt) 538 { 539 struct tun_softc *tp = ifp->if_softc; 540 int error; 541 #if defined(INET) || defined(INET6) 542 int mlen; 543 uint32_t *af; 544 #endif 545 546 mutex_enter(&tp->tun_lock); 547 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 548 549 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 550 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 551 tp->tun_flags); 552 error = EHOSTDOWN; 553 mutex_exit(&tp->tun_lock); 554 goto out; 555 } 556 // XXXrmind 557 mutex_exit(&tp->tun_lock); 558 559 /* 560 * if the queueing discipline needs packet classification, 561 * do it before prepending link headers. 562 */ 563 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 564 565 bpf_mtap_af(ifp, dst->sa_family, m0, BPF_D_OUT); 566 567 if ((error = pfil_run_hooks(ifp->if_pfil, &m0, ifp, PFIL_OUT)) != 0) 568 goto out; 569 if (m0 == NULL) 570 goto out; 571 572 switch(dst->sa_family) { 573 #ifdef INET6 574 case AF_INET6: 575 #endif 576 #ifdef INET 577 case AF_INET: 578 #endif 579 #if defined(INET) || defined(INET6) 580 if (tp->tun_flags & TUN_PREPADDR) { 581 /* Simple link-layer header */ 582 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 583 if (m0 == NULL) { 584 IF_DROP(&ifp->if_snd); 585 error = ENOBUFS; 586 goto out; 587 } 588 memcpy(mtod(m0, char *), dst, dst->sa_len); 589 } 590 591 if (tp->tun_flags & TUN_IFHEAD) { 592 /* Prepend the address family */ 593 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 594 if (m0 == NULL) { 595 IF_DROP(&ifp->if_snd); 596 error = ENOBUFS; 597 goto out; 598 } 599 af = mtod(m0,uint32_t *); 600 *af = htonl(dst->sa_family); 601 } else { 602 #ifdef INET 603 if (dst->sa_family != AF_INET) 604 #endif 605 { 606 error = EAFNOSUPPORT; 607 goto out; 608 } 609 } 610 /* FALLTHROUGH */ 611 case AF_UNSPEC: 612 mlen = m0->m_pkthdr.len; 613 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 614 if (error) { 615 ifp->if_collisions++; 616 error = EAFNOSUPPORT; 617 m0 = NULL; 618 goto out; 619 } 620 ifp->if_opackets++; 621 ifp->if_obytes += mlen; 622 break; 623 #endif 624 default: 625 error = EAFNOSUPPORT; 626 goto out; 627 } 628 629 mutex_enter(&tp->tun_lock); 630 if (tp->tun_flags & TUN_RWAIT) { 631 tp->tun_flags &= ~TUN_RWAIT; 632 cv_broadcast(&tp->tun_cv); 633 } 634 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 635 softint_schedule(tp->tun_isih); 636 637 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 638 639 mutex_exit(&tp->tun_lock); 640 out: 641 if (error && m0) 642 m_freem(m0); 643 644 return error; 645 } 646 647 static void 648 tun_i_softintr(void *cookie) 649 { 650 struct tun_softc *tp = cookie; 651 652 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 653 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 654 NULL); 655 } 656 657 static void 658 tun_o_softintr(void *cookie) 659 { 660 struct tun_softc *tp = cookie; 661 662 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 663 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 664 NULL); 665 } 666 667 /* 668 * the cdevsw interface is now pretty minimal. 669 */ 670 int 671 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 672 { 673 struct tun_softc *tp; 674 int error = 0; 675 676 tp = tun_find_unit(dev); 677 678 /* interface was "destroyed" already */ 679 if (tp == NULL) { 680 return ENXIO; 681 } 682 683 switch (cmd) { 684 case TUNSDEBUG: 685 tundebug = *(int *)data; 686 break; 687 688 case TUNGDEBUG: 689 *(int *)data = tundebug; 690 break; 691 692 case TUNSIFMODE: 693 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 694 case IFF_POINTOPOINT: 695 case IFF_BROADCAST: 696 if (tp->tun_if.if_flags & IFF_UP) { 697 error = EBUSY; 698 goto out; 699 } 700 tp->tun_if.if_flags &= 701 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 702 tp->tun_if.if_flags |= *(int *)data; 703 break; 704 default: 705 error = EINVAL; 706 goto out; 707 } 708 break; 709 710 case TUNSLMODE: 711 if (*(int *)data) { 712 tp->tun_flags |= TUN_PREPADDR; 713 tp->tun_flags &= ~TUN_IFHEAD; 714 } else 715 tp->tun_flags &= ~TUN_PREPADDR; 716 break; 717 718 case TUNSIFHEAD: 719 if (*(int *)data) { 720 tp->tun_flags |= TUN_IFHEAD; 721 tp->tun_flags &= ~TUN_PREPADDR; 722 } else 723 tp->tun_flags &= ~TUN_IFHEAD; 724 break; 725 726 case TUNGIFHEAD: 727 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 728 break; 729 730 case FIONBIO: 731 if (*(int *)data) 732 tp->tun_flags |= TUN_NBIO; 733 else 734 tp->tun_flags &= ~TUN_NBIO; 735 break; 736 737 case FIOASYNC: 738 if (*(int *)data) 739 tp->tun_flags |= TUN_ASYNC; 740 else 741 tp->tun_flags &= ~TUN_ASYNC; 742 break; 743 744 case FIONREAD: 745 if (tp->tun_if.if_snd.ifq_head) 746 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 747 else 748 *(int *)data = 0; 749 break; 750 751 case TIOCSPGRP: 752 case FIOSETOWN: 753 error = fsetown(&tp->tun_pgid, cmd, data); 754 break; 755 756 case TIOCGPGRP: 757 case FIOGETOWN: 758 error = fgetown(tp->tun_pgid, cmd, data); 759 break; 760 761 default: 762 error = ENOTTY; 763 } 764 765 out: 766 mutex_exit(&tp->tun_lock); 767 768 return error; 769 } 770 771 /* 772 * The cdevsw read interface - reads a packet at a time, or at 773 * least as much of a packet as can be read. 774 */ 775 int 776 tunread(dev_t dev, struct uio *uio, int ioflag) 777 { 778 struct tun_softc *tp; 779 struct ifnet *ifp; 780 struct mbuf *m, *m0; 781 int error = 0, len; 782 783 tp = tun_find_unit(dev); 784 785 /* interface was "destroyed" already */ 786 if (tp == NULL) { 787 return ENXIO; 788 } 789 790 ifp = &tp->tun_if; 791 792 TUNDEBUG ("%s: read\n", ifp->if_xname); 793 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 794 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 795 error = EHOSTDOWN; 796 goto out; 797 } 798 799 tp->tun_flags &= ~TUN_RWAIT; 800 801 do { 802 IFQ_DEQUEUE(&ifp->if_snd, m0); 803 if (m0 == 0) { 804 if (tp->tun_flags & TUN_NBIO) { 805 error = EWOULDBLOCK; 806 goto out; 807 } 808 tp->tun_flags |= TUN_RWAIT; 809 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 810 error = EINTR; 811 goto out; 812 } 813 } 814 } while (m0 == 0); 815 816 mutex_exit(&tp->tun_lock); 817 818 /* Copy the mbuf chain */ 819 while (m0 && uio->uio_resid > 0 && error == 0) { 820 len = uimin(uio->uio_resid, m0->m_len); 821 if (len != 0) 822 error = uiomove(mtod(m0, void *), len, uio); 823 m0 = m = m_free(m0); 824 } 825 826 if (m0) { 827 TUNDEBUG("Dropping mbuf\n"); 828 m_freem(m0); 829 } 830 if (error) 831 ifp->if_ierrors++; 832 833 return error; 834 835 out: 836 mutex_exit(&tp->tun_lock); 837 838 return error; 839 } 840 841 /* 842 * the cdevsw write interface - an atomic write is a packet - or else! 843 */ 844 int 845 tunwrite(dev_t dev, struct uio *uio, int ioflag) 846 { 847 struct tun_softc *tp; 848 struct ifnet *ifp; 849 struct mbuf *top, **mp, *m; 850 pktqueue_t *pktq; 851 struct sockaddr dst; 852 int error = 0, tlen, mlen; 853 uint32_t family; 854 855 tp = tun_find_unit(dev); 856 if (tp == NULL) { 857 /* Interface was "destroyed" already. */ 858 return ENXIO; 859 } 860 861 /* Unlock until we've got the data */ 862 mutex_exit(&tp->tun_lock); 863 864 ifp = &tp->tun_if; 865 866 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 867 868 if (tp->tun_flags & TUN_PREPADDR) { 869 if (uio->uio_resid < sizeof(dst)) { 870 error = EIO; 871 goto out0; 872 } 873 error = uiomove((void *)&dst, sizeof(dst), uio); 874 if (dst.sa_len > sizeof(dst)) { 875 /* Duh.. */ 876 int n = dst.sa_len - sizeof(dst); 877 while (n--) { 878 char discard; 879 error = uiomove(&discard, 1, uio); 880 if (error) { 881 goto out0; 882 } 883 } 884 } 885 } else if (tp->tun_flags & TUN_IFHEAD) { 886 if (uio->uio_resid < sizeof(family)){ 887 error = EIO; 888 goto out0; 889 } 890 error = uiomove((void *)&family, sizeof(family), uio); 891 dst.sa_family = ntohl(family); 892 } else { 893 #ifdef INET 894 dst.sa_family = AF_INET; 895 #endif 896 } 897 898 if (uio->uio_resid > TUNMTU) { 899 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 900 (unsigned long)uio->uio_resid); 901 error = EIO; 902 goto out0; 903 } 904 905 switch (dst.sa_family) { 906 #ifdef INET 907 case AF_INET: 908 pktq = ip_pktq; 909 break; 910 #endif 911 #ifdef INET6 912 case AF_INET6: 913 pktq = ip6_pktq; 914 break; 915 #endif 916 default: 917 error = EAFNOSUPPORT; 918 goto out0; 919 } 920 921 tlen = uio->uio_resid; 922 923 /* get a header mbuf */ 924 MGETHDR(m, M_DONTWAIT, MT_DATA); 925 if (m == NULL) { 926 return ENOBUFS; 927 } 928 mlen = MHLEN; 929 930 top = NULL; 931 mp = ⊤ 932 while (error == 0 && uio->uio_resid > 0) { 933 m->m_len = uimin(mlen, uio->uio_resid); 934 error = uiomove(mtod(m, void *), m->m_len, uio); 935 *mp = m; 936 mp = &m->m_next; 937 if (error == 0 && uio->uio_resid > 0) { 938 MGET(m, M_DONTWAIT, MT_DATA); 939 if (m == NULL) { 940 error = ENOBUFS; 941 break; 942 } 943 mlen = MLEN; 944 } 945 } 946 if (error) { 947 if (top != NULL) 948 m_freem(top); 949 ifp->if_ierrors++; 950 goto out0; 951 } 952 953 top->m_pkthdr.len = tlen; 954 m_set_rcvif(top, ifp); 955 956 bpf_mtap_af(ifp, dst.sa_family, top, BPF_D_IN); 957 958 if ((error = pfil_run_hooks(ifp->if_pfil, &top, ifp, PFIL_IN)) != 0) 959 goto out0; 960 if (top == NULL) 961 goto out0; 962 963 mutex_enter(&tp->tun_lock); 964 if ((tp->tun_flags & TUN_INITED) == 0) { 965 /* Interface was destroyed */ 966 error = ENXIO; 967 goto out; 968 } 969 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 970 ifp->if_collisions++; 971 mutex_exit(&tp->tun_lock); 972 error = ENOBUFS; 973 m_freem(top); 974 goto out0; 975 } 976 ifp->if_ipackets++; 977 ifp->if_ibytes += tlen; 978 out: 979 mutex_exit(&tp->tun_lock); 980 out0: 981 return error; 982 } 983 984 #ifdef ALTQ 985 /* 986 * Start packet transmission on the interface. 987 * when the interface queue is rate-limited by ALTQ or TBR, 988 * if_start is needed to drain packets from the queue in order 989 * to notify readers when outgoing packets become ready. 990 */ 991 static void 992 tunstart(struct ifnet *ifp) 993 { 994 struct tun_softc *tp = ifp->if_softc; 995 996 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 997 return; 998 999 mutex_enter(&tp->tun_lock); 1000 if (!IF_IS_EMPTY(&ifp->if_snd)) { 1001 if (tp->tun_flags & TUN_RWAIT) { 1002 tp->tun_flags &= ~TUN_RWAIT; 1003 cv_broadcast(&tp->tun_cv); 1004 } 1005 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 1006 softint_schedule(tp->tun_osih); 1007 1008 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 1009 } 1010 mutex_exit(&tp->tun_lock); 1011 } 1012 #endif /* ALTQ */ 1013 /* 1014 * tunpoll - the poll interface, this is only useful on reads 1015 * really. The write detect always returns true, write never blocks 1016 * anyway, it either accepts the packet or drops it. 1017 */ 1018 int 1019 tunpoll(dev_t dev, int events, struct lwp *l) 1020 { 1021 struct tun_softc *tp; 1022 struct ifnet *ifp; 1023 int revents = 0; 1024 1025 tp = tun_find_unit(dev); 1026 if (tp == NULL) { 1027 /* Interface was "destroyed" already. */ 1028 return 0; 1029 } 1030 ifp = &tp->tun_if; 1031 1032 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1033 1034 if (events & (POLLIN | POLLRDNORM)) { 1035 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1036 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1037 ifp->if_snd.ifq_len); 1038 revents |= events & (POLLIN | POLLRDNORM); 1039 } else { 1040 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1041 selrecord(l, &tp->tun_rsel); 1042 } 1043 } 1044 1045 if (events & (POLLOUT | POLLWRNORM)) 1046 revents |= events & (POLLOUT | POLLWRNORM); 1047 1048 mutex_exit(&tp->tun_lock); 1049 1050 return revents; 1051 } 1052 1053 static void 1054 filt_tunrdetach(struct knote *kn) 1055 { 1056 struct tun_softc *tp = kn->kn_hook; 1057 1058 mutex_enter(&tp->tun_lock); 1059 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1060 mutex_exit(&tp->tun_lock); 1061 } 1062 1063 static int 1064 filt_tunread(struct knote *kn, long hint) 1065 { 1066 struct tun_softc *tp = kn->kn_hook; 1067 struct ifnet *ifp = &tp->tun_if; 1068 struct mbuf *m; 1069 int ready; 1070 1071 if (hint & NOTE_SUBMIT) 1072 KASSERT(mutex_owned(&tp->tun_lock)); 1073 else 1074 mutex_enter(&tp->tun_lock); 1075 1076 IF_POLL(&ifp->if_snd, m); 1077 ready = (m != NULL); 1078 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1079 kn->kn_data += m->m_len; 1080 1081 if (hint & NOTE_SUBMIT) 1082 KASSERT(mutex_owned(&tp->tun_lock)); 1083 else 1084 mutex_exit(&tp->tun_lock); 1085 1086 return ready; 1087 } 1088 1089 static const struct filterops tunread_filtops = { 1090 .f_isfd = 1, 1091 .f_attach = NULL, 1092 .f_detach = filt_tunrdetach, 1093 .f_event = filt_tunread, 1094 }; 1095 1096 static const struct filterops tun_seltrue_filtops = { 1097 .f_isfd = 1, 1098 .f_attach = NULL, 1099 .f_detach = filt_tunrdetach, 1100 .f_event = filt_seltrue, 1101 }; 1102 1103 int 1104 tunkqfilter(dev_t dev, struct knote *kn) 1105 { 1106 struct tun_softc *tp; 1107 struct klist *klist; 1108 int rv = 0; 1109 1110 tp = tun_find_unit(dev); 1111 if (tp == NULL) 1112 goto out_nolock; 1113 1114 switch (kn->kn_filter) { 1115 case EVFILT_READ: 1116 klist = &tp->tun_rsel.sel_klist; 1117 kn->kn_fop = &tunread_filtops; 1118 break; 1119 1120 case EVFILT_WRITE: 1121 klist = &tp->tun_rsel.sel_klist; 1122 kn->kn_fop = &tun_seltrue_filtops; 1123 break; 1124 1125 default: 1126 rv = EINVAL; 1127 goto out; 1128 } 1129 1130 kn->kn_hook = tp; 1131 1132 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1133 1134 out: 1135 mutex_exit(&tp->tun_lock); 1136 out_nolock: 1137 return rv; 1138 } 1139 1140 /* 1141 * Module infrastructure 1142 */ 1143 #include "if_module.h" 1144 1145 IF_MODULE(MODULE_CLASS_DRIVER, tun, NULL) 1146
Indexes created Tue Sep 23 02:09:52 GMT 2025