if_tun.c revision 1.154
1 /* $NetBSD: if_tun.c,v 1.154 2019/03/25 09:07:24 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 1.154 2019/03/25 09:07:24 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_clone_detach(&tun_cloner); 148 #ifdef _MODULE 149 error = devsw_detach(NULL, &tun_cdevsw); 150 if (error != 0) { 151 if_clone_attach(&tun_cloner); 152 return error; 153 } 154 #endif 155 156 if (!LIST_EMPTY(&tun_softc_list) || !LIST_EMPTY(&tunz_softc_list)) { 157 #ifdef _MODULE 158 devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); 159 #endif 160 if_clone_attach(&tun_cloner); 161 return EBUSY; 162 } 163 164 mutex_destroy(&tun_softc_lock); 165 166 return 0; 167 } 168 169 /* 170 * Find driver instance from dev_t. 171 * Returns with tp locked (if found). 172 */ 173 static struct tun_softc * 174 tun_find_unit(dev_t dev) 175 { 176 struct tun_softc *tp; 177 int unit = minor(dev); 178 179 mutex_enter(&tun_softc_lock); 180 LIST_FOREACH(tp, &tun_softc_list, tun_list) 181 if (unit == tp->tun_unit) 182 break; 183 if (tp) 184 mutex_enter(&tp->tun_lock); 185 mutex_exit(&tun_softc_lock); 186 187 return tp; 188 } 189 190 /* 191 * Find zombie driver instance by unit number. 192 * Remove tp from list and return it unlocked (if found). 193 */ 194 static struct tun_softc * 195 tun_find_zunit(int unit) 196 { 197 struct tun_softc *tp; 198 199 mutex_enter(&tun_softc_lock); 200 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 201 if (unit == tp->tun_unit) 202 break; 203 if (tp) 204 LIST_REMOVE(tp, tun_list); 205 mutex_exit(&tun_softc_lock); 206 KASSERTMSG(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) == TUN_OPEN, 207 "tun%d: inconsistent flags: %x", unit, tp->tun_flags); 208 209 return tp; 210 } 211 212 static int 213 tun_clone_create(struct if_clone *ifc, int unit) 214 { 215 struct tun_softc *tp; 216 217 if ((tp = tun_find_zunit(unit)) == NULL) { 218 tp = kmem_zalloc(sizeof(*tp), KM_SLEEP); 219 220 tp->tun_unit = unit; 221 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 222 cv_init(&tp->tun_cv, "tunread"); 223 selinit(&tp->tun_rsel); 224 selinit(&tp->tun_wsel); 225 } else { 226 /* Revive tunnel instance; clear ifp part */ 227 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 228 } 229 230 if_initname(&tp->tun_if, ifc->ifc_name, unit); 231 tunattach0(tp); 232 tp->tun_flags |= TUN_INITED; 233 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 234 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 235 236 mutex_enter(&tun_softc_lock); 237 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 238 mutex_exit(&tun_softc_lock); 239 240 return 0; 241 } 242 243 static void 244 tunattach0(struct tun_softc *tp) 245 { 246 struct ifnet *ifp; 247 248 ifp = &tp->tun_if; 249 ifp->if_softc = tp; 250 ifp->if_mtu = TUNMTU; 251 ifp->if_ioctl = tun_ioctl; 252 ifp->if_output = tun_output; 253 #ifdef ALTQ 254 ifp->if_start = tunstart; 255 #endif 256 ifp->if_flags = IFF_POINTOPOINT; 257 ifp->if_extflags = IFEF_NO_LINK_STATE_CHANGE; 258 ifp->if_type = IFT_TUNNEL; 259 ifp->if_snd.ifq_maxlen = ifqmaxlen; 260 ifp->if_collisions = 0; 261 ifp->if_ierrors = 0; 262 ifp->if_oerrors = 0; 263 ifp->if_ipackets = 0; 264 ifp->if_opackets = 0; 265 ifp->if_ibytes = 0; 266 ifp->if_obytes = 0; 267 ifp->if_dlt = DLT_NULL; 268 IFQ_SET_READY(&ifp->if_snd); 269 if_attach(ifp); 270 if_alloc_sadl(ifp); 271 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 272 } 273 274 static int 275 tun_clone_destroy(struct ifnet *ifp) 276 { 277 struct tun_softc *tp = (void *)ifp; 278 bool zombie = false; 279 280 IF_PURGE(&ifp->if_snd); 281 ifp->if_flags &= ~IFF_RUNNING; 282 283 mutex_enter(&tun_softc_lock); 284 mutex_enter(&tp->tun_lock); 285 LIST_REMOVE(tp, tun_list); 286 if (tp->tun_flags & TUN_OPEN) { 287 /* Hang on to storage until last close. */ 288 tp->tun_flags &= ~TUN_INITED; 289 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 290 zombie = true; 291 } 292 mutex_exit(&tun_softc_lock); 293 294 if (tp->tun_flags & TUN_RWAIT) { 295 tp->tun_flags &= ~TUN_RWAIT; 296 cv_broadcast(&tp->tun_cv); 297 } 298 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 299 300 mutex_exit(&tp->tun_lock); 301 302 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 303 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 304 305 bpf_detach(ifp); 306 if_detach(ifp); 307 308 if (!zombie) { 309 seldestroy(&tp->tun_rsel); 310 seldestroy(&tp->tun_wsel); 311 softint_disestablish(tp->tun_osih); 312 softint_disestablish(tp->tun_isih); 313 mutex_destroy(&tp->tun_lock); 314 cv_destroy(&tp->tun_cv); 315 kmem_free(tp, sizeof(*tp)); 316 } 317 318 return 0; 319 } 320 321 /* 322 * tunnel open - must be superuser & the device must be 323 * configured in 324 */ 325 static int 326 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 327 { 328 struct ifnet *ifp; 329 struct tun_softc *tp; 330 int error; 331 332 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 333 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 334 if (error) 335 return error; 336 337 tp = tun_find_unit(dev); 338 339 if (tp == NULL) { 340 (void)tun_clone_create(&tun_cloner, minor(dev)); 341 tp = tun_find_unit(dev); 342 if (tp == NULL) { 343 return ENXIO; 344 } 345 } 346 347 if (tp->tun_flags & TUN_OPEN) { 348 mutex_exit(&tp->tun_lock); 349 return EBUSY; 350 } 351 352 ifp = &tp->tun_if; 353 tp->tun_flags |= TUN_OPEN; 354 TUNDEBUG("%s: open\n", ifp->if_xname); 355 356 mutex_exit(&tp->tun_lock); 357 358 return error; 359 } 360 361 /* 362 * tunclose - close the device - mark i/f down & delete 363 * routing info 364 */ 365 int 366 tunclose(dev_t dev, int flag, int mode, 367 struct lwp *l) 368 { 369 struct tun_softc *tp; 370 struct ifnet *ifp; 371 372 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 373 /* interface was "destroyed" before the close */ 374 seldestroy(&tp->tun_rsel); 375 seldestroy(&tp->tun_wsel); 376 softint_disestablish(tp->tun_osih); 377 softint_disestablish(tp->tun_isih); 378 mutex_destroy(&tp->tun_lock); 379 kmem_free(tp, sizeof(*tp)); 380 return 0; 381 } 382 383 if ((tp = tun_find_unit(dev)) == NULL) 384 goto out_nolock; 385 386 ifp = &tp->tun_if; 387 388 tp->tun_flags &= ~TUN_OPEN; 389 390 tp->tun_pgid = 0; 391 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 392 393 TUNDEBUG ("%s: closed\n", ifp->if_xname); 394 mutex_exit(&tp->tun_lock); 395 396 /* 397 * junk all pending output 398 */ 399 IFQ_PURGE(&ifp->if_snd); 400 401 if (ifp->if_flags & IFF_UP) { 402 if_down(ifp); 403 if (ifp->if_flags & IFF_RUNNING) { 404 /* find internet addresses and delete routes */ 405 struct ifaddr *ifa; 406 IFADDR_READER_FOREACH(ifa, ifp) { 407 #if defined(INET) || defined(INET6) 408 if (ifa->ifa_addr->sa_family == AF_INET || 409 ifa->ifa_addr->sa_family == AF_INET6) { 410 rtinit(ifa, (int)RTM_DELETE, 411 tp->tun_flags & TUN_DSTADDR 412 ? RTF_HOST 413 : 0); 414 } 415 #endif 416 } 417 } 418 } 419 out_nolock: 420 return 0; 421 } 422 423 static void 424 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 425 { 426 struct ifnet *ifp = &tp->tun_if; 427 428 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 429 430 mutex_enter(&tp->tun_lock); 431 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 432 433 switch (ifa->ifa_addr->sa_family) { 434 #ifdef INET 435 case AF_INET: { 436 struct sockaddr_in *sin; 437 438 sin = satosin(ifa->ifa_addr); 439 if (sin && sin->sin_addr.s_addr) 440 tp->tun_flags |= TUN_IASET; 441 442 if (ifp->if_flags & IFF_POINTOPOINT) { 443 sin = satosin(ifa->ifa_dstaddr); 444 if (sin && sin->sin_addr.s_addr) 445 tp->tun_flags |= TUN_DSTADDR; 446 } 447 break; 448 } 449 #endif 450 #ifdef INET6 451 case AF_INET6: { 452 struct sockaddr_in6 *sin; 453 454 sin = satosin6(ifa->ifa_addr); 455 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 456 tp->tun_flags |= TUN_IASET; 457 458 if (ifp->if_flags & IFF_POINTOPOINT) { 459 sin = satosin6(ifa->ifa_dstaddr); 460 if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 461 tp->tun_flags |= TUN_DSTADDR; 462 } else 463 tp->tun_flags &= ~TUN_DSTADDR; 464 break; 465 } 466 #endif /* INET6 */ 467 default: 468 break; 469 } 470 ifp->if_flags |= IFF_UP | IFF_RUNNING; 471 mutex_exit(&tp->tun_lock); 472 } 473 474 /* 475 * Process an ioctl request. 476 */ 477 static int 478 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 479 { 480 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 481 struct ifreq *ifr = (struct ifreq *)data; 482 struct ifaddr *ifa = (struct ifaddr *)data; 483 int error = 0; 484 485 switch (cmd) { 486 case SIOCINITIFADDR: 487 tun_enable(tp, ifa); 488 ifa->ifa_rtrequest = p2p_rtrequest; 489 TUNDEBUG("%s: address set\n", ifp->if_xname); 490 break; 491 case SIOCSIFBRDADDR: 492 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 493 break; 494 case SIOCSIFMTU: 495 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 496 error = EINVAL; 497 break; 498 } 499 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 500 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 501 error = 0; 502 break; 503 case SIOCADDMULTI: 504 case SIOCDELMULTI: 505 if (ifr == NULL) { 506 error = EAFNOSUPPORT; /* XXX */ 507 break; 508 } 509 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 510 #ifdef INET 511 case AF_INET: 512 break; 513 #endif 514 #ifdef INET6 515 case AF_INET6: 516 break; 517 #endif 518 default: 519 error = EAFNOSUPPORT; 520 break; 521 } 522 break; 523 default: 524 error = ifioctl_common(ifp, cmd, data); 525 } 526 527 return error; 528 } 529 530 /* 531 * tun_output - queue packets from higher level ready to put out. 532 */ 533 static int 534 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 535 const struct rtentry *rt) 536 { 537 struct tun_softc *tp = ifp->if_softc; 538 int error; 539 #if defined(INET) || defined(INET6) 540 int mlen; 541 uint32_t *af; 542 #endif 543 544 mutex_enter(&tp->tun_lock); 545 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 546 547 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 548 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 549 tp->tun_flags); 550 error = EHOSTDOWN; 551 mutex_exit(&tp->tun_lock); 552 goto out; 553 } 554 // XXXrmind 555 mutex_exit(&tp->tun_lock); 556 557 /* 558 * if the queueing discipline needs packet classification, 559 * do it before prepending link headers. 560 */ 561 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 562 563 bpf_mtap_af(ifp, dst->sa_family, m0, BPF_D_OUT); 564 565 if ((error = pfil_run_hooks(ifp->if_pfil, &m0, ifp, PFIL_OUT)) != 0) 566 goto out; 567 if (m0 == NULL) 568 goto out; 569 570 switch(dst->sa_family) { 571 #ifdef INET6 572 case AF_INET6: 573 #endif 574 #ifdef INET 575 case AF_INET: 576 #endif 577 #if defined(INET) || defined(INET6) 578 if (tp->tun_flags & TUN_PREPADDR) { 579 /* Simple link-layer header */ 580 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 581 if (m0 == NULL) { 582 IF_DROP(&ifp->if_snd); 583 error = ENOBUFS; 584 goto out; 585 } 586 memcpy(mtod(m0, char *), dst, dst->sa_len); 587 } 588 589 if (tp->tun_flags & TUN_IFHEAD) { 590 /* Prepend the address family */ 591 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 592 if (m0 == NULL) { 593 IF_DROP(&ifp->if_snd); 594 error = ENOBUFS; 595 goto out; 596 } 597 af = mtod(m0,uint32_t *); 598 *af = htonl(dst->sa_family); 599 } else { 600 #ifdef INET 601 if (dst->sa_family != AF_INET) 602 #endif 603 { 604 error = EAFNOSUPPORT; 605 goto out; 606 } 607 } 608 /* FALLTHROUGH */ 609 case AF_UNSPEC: 610 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 611 if (error) { 612 ifp->if_collisions++; 613 error = EAFNOSUPPORT; 614 m0 = NULL; 615 goto out; 616 } 617 mlen = m0->m_pkthdr.len; 618 ifp->if_opackets++; 619 ifp->if_obytes += mlen; 620 break; 621 #endif 622 default: 623 error = EAFNOSUPPORT; 624 goto out; 625 } 626 627 mutex_enter(&tp->tun_lock); 628 if (tp->tun_flags & TUN_RWAIT) { 629 tp->tun_flags &= ~TUN_RWAIT; 630 cv_broadcast(&tp->tun_cv); 631 } 632 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 633 softint_schedule(tp->tun_isih); 634 635 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 636 637 mutex_exit(&tp->tun_lock); 638 out: 639 if (error && m0) 640 m_freem(m0); 641 642 return error; 643 } 644 645 static void 646 tun_i_softintr(void *cookie) 647 { 648 struct tun_softc *tp = cookie; 649 650 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 651 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 652 NULL); 653 } 654 655 static void 656 tun_o_softintr(void *cookie) 657 { 658 struct tun_softc *tp = cookie; 659 660 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 661 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 662 NULL); 663 } 664 665 /* 666 * the cdevsw interface is now pretty minimal. 667 */ 668 int 669 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 670 { 671 struct tun_softc *tp; 672 int error = 0; 673 674 tp = tun_find_unit(dev); 675 676 /* interface was "destroyed" already */ 677 if (tp == NULL) { 678 return ENXIO; 679 } 680 681 switch (cmd) { 682 case TUNSDEBUG: 683 tundebug = *(int *)data; 684 break; 685 686 case TUNGDEBUG: 687 *(int *)data = tundebug; 688 break; 689 690 case TUNSIFMODE: 691 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 692 case IFF_POINTOPOINT: 693 case IFF_BROADCAST: 694 if (tp->tun_if.if_flags & IFF_UP) { 695 error = EBUSY; 696 goto out; 697 } 698 tp->tun_if.if_flags &= 699 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 700 tp->tun_if.if_flags |= *(int *)data; 701 break; 702 default: 703 error = EINVAL; 704 goto out; 705 } 706 break; 707 708 case TUNSLMODE: 709 if (*(int *)data) { 710 tp->tun_flags |= TUN_PREPADDR; 711 tp->tun_flags &= ~TUN_IFHEAD; 712 } else 713 tp->tun_flags &= ~TUN_PREPADDR; 714 break; 715 716 case TUNSIFHEAD: 717 if (*(int *)data) { 718 tp->tun_flags |= TUN_IFHEAD; 719 tp->tun_flags &= ~TUN_PREPADDR; 720 } else 721 tp->tun_flags &= ~TUN_IFHEAD; 722 break; 723 724 case TUNGIFHEAD: 725 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 726 break; 727 728 case FIONBIO: 729 if (*(int *)data) 730 tp->tun_flags |= TUN_NBIO; 731 else 732 tp->tun_flags &= ~TUN_NBIO; 733 break; 734 735 case FIOASYNC: 736 if (*(int *)data) 737 tp->tun_flags |= TUN_ASYNC; 738 else 739 tp->tun_flags &= ~TUN_ASYNC; 740 break; 741 742 case FIONREAD: 743 if (tp->tun_if.if_snd.ifq_head) 744 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 745 else 746 *(int *)data = 0; 747 break; 748 749 case TIOCSPGRP: 750 case FIOSETOWN: 751 error = fsetown(&tp->tun_pgid, cmd, data); 752 break; 753 754 case TIOCGPGRP: 755 case FIOGETOWN: 756 error = fgetown(tp->tun_pgid, cmd, data); 757 break; 758 759 default: 760 error = ENOTTY; 761 } 762 763 out: 764 mutex_exit(&tp->tun_lock); 765 766 return error; 767 } 768 769 /* 770 * The cdevsw read interface - reads a packet at a time, or at 771 * least as much of a packet as can be read. 772 */ 773 int 774 tunread(dev_t dev, struct uio *uio, int ioflag) 775 { 776 struct tun_softc *tp; 777 struct ifnet *ifp; 778 struct mbuf *m, *m0; 779 int error = 0, len; 780 781 tp = tun_find_unit(dev); 782 783 /* interface was "destroyed" already */ 784 if (tp == NULL) { 785 return ENXIO; 786 } 787 788 ifp = &tp->tun_if; 789 790 TUNDEBUG ("%s: read\n", ifp->if_xname); 791 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 792 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 793 error = EHOSTDOWN; 794 goto out; 795 } 796 797 tp->tun_flags &= ~TUN_RWAIT; 798 799 do { 800 IFQ_DEQUEUE(&ifp->if_snd, m0); 801 if (m0 == 0) { 802 if (tp->tun_flags & TUN_NBIO) { 803 error = EWOULDBLOCK; 804 goto out; 805 } 806 tp->tun_flags |= TUN_RWAIT; 807 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 808 error = EINTR; 809 goto out; 810 } 811 } 812 } while (m0 == 0); 813 814 mutex_exit(&tp->tun_lock); 815 816 /* Copy the mbuf chain */ 817 while (m0 && uio->uio_resid > 0 && error == 0) { 818 len = uimin(uio->uio_resid, m0->m_len); 819 if (len != 0) 820 error = uiomove(mtod(m0, void *), len, uio); 821 m0 = m = m_free(m0); 822 } 823 824 if (m0) { 825 TUNDEBUG("Dropping mbuf\n"); 826 m_freem(m0); 827 } 828 if (error) 829 ifp->if_ierrors++; 830 831 return error; 832 833 out: 834 mutex_exit(&tp->tun_lock); 835 836 return error; 837 } 838 839 /* 840 * the cdevsw write interface - an atomic write is a packet - or else! 841 */ 842 int 843 tunwrite(dev_t dev, struct uio *uio, int ioflag) 844 { 845 struct tun_softc *tp; 846 struct ifnet *ifp; 847 struct mbuf *top, **mp, *m; 848 pktqueue_t *pktq; 849 struct sockaddr dst; 850 int error = 0, tlen, mlen; 851 uint32_t family; 852 853 tp = tun_find_unit(dev); 854 if (tp == NULL) { 855 /* Interface was "destroyed" already. */ 856 return ENXIO; 857 } 858 859 /* Unlock until we've got the data */ 860 mutex_exit(&tp->tun_lock); 861 862 ifp = &tp->tun_if; 863 864 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 865 866 if (tp->tun_flags & TUN_PREPADDR) { 867 if (uio->uio_resid < sizeof(dst)) { 868 error = EIO; 869 goto out0; 870 } 871 error = uiomove((void *)&dst, sizeof(dst), uio); 872 if (dst.sa_len > sizeof(dst)) { 873 /* Duh.. */ 874 int n = dst.sa_len - sizeof(dst); 875 while (n--) { 876 char discard; 877 error = uiomove(&discard, 1, uio); 878 if (error) { 879 goto out0; 880 } 881 } 882 } 883 } else if (tp->tun_flags & TUN_IFHEAD) { 884 if (uio->uio_resid < sizeof(family)){ 885 error = EIO; 886 goto out0; 887 } 888 error = uiomove((void *)&family, sizeof(family), uio); 889 dst.sa_family = ntohl(family); 890 } else { 891 #ifdef INET 892 dst.sa_family = AF_INET; 893 #endif 894 } 895 896 if (uio->uio_resid > TUNMTU) { 897 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 898 (unsigned long)uio->uio_resid); 899 error = EIO; 900 goto out0; 901 } 902 903 switch (dst.sa_family) { 904 #ifdef INET 905 case AF_INET: 906 pktq = ip_pktq; 907 break; 908 #endif 909 #ifdef INET6 910 case AF_INET6: 911 pktq = ip6_pktq; 912 break; 913 #endif 914 default: 915 error = EAFNOSUPPORT; 916 goto out0; 917 } 918 919 tlen = uio->uio_resid; 920 921 /* get a header mbuf */ 922 MGETHDR(m, M_DONTWAIT, MT_DATA); 923 if (m == NULL) { 924 return ENOBUFS; 925 } 926 mlen = MHLEN; 927 928 top = NULL; 929 mp = ⊤ 930 while (error == 0 && uio->uio_resid > 0) { 931 m->m_len = uimin(mlen, uio->uio_resid); 932 error = uiomove(mtod(m, void *), m->m_len, uio); 933 *mp = m; 934 mp = &m->m_next; 935 if (error == 0 && uio->uio_resid > 0) { 936 MGET(m, M_DONTWAIT, MT_DATA); 937 if (m == NULL) { 938 error = ENOBUFS; 939 break; 940 } 941 mlen = MLEN; 942 } 943 } 944 if (error) { 945 if (top != NULL) 946 m_freem(top); 947 ifp->if_ierrors++; 948 goto out0; 949 } 950 951 top->m_pkthdr.len = tlen; 952 m_set_rcvif(top, ifp); 953 954 bpf_mtap_af(ifp, dst.sa_family, top, BPF_D_IN); 955 956 if ((error = pfil_run_hooks(ifp->if_pfil, &top, ifp, PFIL_IN)) != 0) 957 goto out0; 958 if (top == NULL) 959 goto out0; 960 961 mutex_enter(&tp->tun_lock); 962 if ((tp->tun_flags & TUN_INITED) == 0) { 963 /* Interface was destroyed */ 964 error = ENXIO; 965 goto out; 966 } 967 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 968 ifp->if_collisions++; 969 mutex_exit(&tp->tun_lock); 970 error = ENOBUFS; 971 m_freem(top); 972 goto out0; 973 } 974 ifp->if_ipackets++; 975 ifp->if_ibytes += tlen; 976 out: 977 mutex_exit(&tp->tun_lock); 978 out0: 979 return error; 980 } 981 982 #ifdef ALTQ 983 /* 984 * Start packet transmission on the interface. 985 * when the interface queue is rate-limited by ALTQ or TBR, 986 * if_start is needed to drain packets from the queue in order 987 * to notify readers when outgoing packets become ready. 988 */ 989 static void 990 tunstart(struct ifnet *ifp) 991 { 992 struct tun_softc *tp = ifp->if_softc; 993 994 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 995 return; 996 997 mutex_enter(&tp->tun_lock); 998 if (!IF_IS_EMPTY(&ifp->if_snd)) { 999 if (tp->tun_flags & TUN_RWAIT) { 1000 tp->tun_flags &= ~TUN_RWAIT; 1001 cv_broadcast(&tp->tun_cv); 1002 } 1003 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 1004 softint_schedule(tp->tun_osih); 1005 1006 selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); 1007 } 1008 mutex_exit(&tp->tun_lock); 1009 } 1010 #endif /* ALTQ */ 1011 /* 1012 * tunpoll - the poll interface, this is only useful on reads 1013 * really. The write detect always returns true, write never blocks 1014 * anyway, it either accepts the packet or drops it. 1015 */ 1016 int 1017 tunpoll(dev_t dev, int events, struct lwp *l) 1018 { 1019 struct tun_softc *tp; 1020 struct ifnet *ifp; 1021 int revents = 0; 1022 1023 tp = tun_find_unit(dev); 1024 if (tp == NULL) { 1025 /* Interface was "destroyed" already. */ 1026 return 0; 1027 } 1028 ifp = &tp->tun_if; 1029 1030 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1031 1032 if (events & (POLLIN | POLLRDNORM)) { 1033 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1034 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1035 ifp->if_snd.ifq_len); 1036 revents |= events & (POLLIN | POLLRDNORM); 1037 } else { 1038 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1039 selrecord(l, &tp->tun_rsel); 1040 } 1041 } 1042 1043 if (events & (POLLOUT | POLLWRNORM)) 1044 revents |= events & (POLLOUT | POLLWRNORM); 1045 1046 mutex_exit(&tp->tun_lock); 1047 1048 return revents; 1049 } 1050 1051 static void 1052 filt_tunrdetach(struct knote *kn) 1053 { 1054 struct tun_softc *tp = kn->kn_hook; 1055 1056 mutex_enter(&tp->tun_lock); 1057 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1058 mutex_exit(&tp->tun_lock); 1059 } 1060 1061 static int 1062 filt_tunread(struct knote *kn, long hint) 1063 { 1064 struct tun_softc *tp = kn->kn_hook; 1065 struct ifnet *ifp = &tp->tun_if; 1066 struct mbuf *m; 1067 int ready; 1068 1069 if (hint & NOTE_SUBMIT) 1070 KASSERT(mutex_owned(&tp->tun_lock)); 1071 else 1072 mutex_enter(&tp->tun_lock); 1073 1074 IF_POLL(&ifp->if_snd, m); 1075 ready = (m != NULL); 1076 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1077 kn->kn_data += m->m_len; 1078 1079 if (hint & NOTE_SUBMIT) 1080 KASSERT(mutex_owned(&tp->tun_lock)); 1081 else 1082 mutex_exit(&tp->tun_lock); 1083 1084 return ready; 1085 } 1086 1087 static const struct filterops tunread_filtops = { 1088 .f_isfd = 1, 1089 .f_attach = NULL, 1090 .f_detach = filt_tunrdetach, 1091 .f_event = filt_tunread, 1092 }; 1093 1094 static const struct filterops tun_seltrue_filtops = { 1095 .f_isfd = 1, 1096 .f_attach = NULL, 1097 .f_detach = filt_tunrdetach, 1098 .f_event = filt_seltrue, 1099 }; 1100 1101 int 1102 tunkqfilter(dev_t dev, struct knote *kn) 1103 { 1104 struct tun_softc *tp; 1105 struct klist *klist; 1106 int rv = 0; 1107 1108 tp = tun_find_unit(dev); 1109 if (tp == NULL) 1110 goto out_nolock; 1111 1112 switch (kn->kn_filter) { 1113 case EVFILT_READ: 1114 klist = &tp->tun_rsel.sel_klist; 1115 kn->kn_fop = &tunread_filtops; 1116 break; 1117 1118 case EVFILT_WRITE: 1119 klist = &tp->tun_rsel.sel_klist; 1120 kn->kn_fop = &tun_seltrue_filtops; 1121 break; 1122 1123 default: 1124 rv = EINVAL; 1125 goto out; 1126 } 1127 1128 kn->kn_hook = tp; 1129 1130 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1131 1132 out: 1133 mutex_exit(&tp->tun_lock); 1134 out_nolock: 1135 return rv; 1136 } 1137 1138 /* 1139 * Module infrastructure 1140 */ 1141 #include "if_module.h" 1142 1143 IF_MODULE(MODULE_CLASS_DRIVER, tun, "") 1144
Indexes created Fri Sep 26 08:10:20 GMT 2025