if_tun.c revision 1.138
1 /* $NetBSD: if_tun.c,v 1.138 2017/01/29 18:30:33 maya 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 1.138 2017/01/29 18:30:33 maya Exp $"); 23 24 #ifdef _KERNEL_OPT 25 #include "opt_inet.h" 26 #endif 27 28 #include <sys/param.h> 29 30 #include <sys/buf.h> 31 #include <sys/conf.h> 32 #include <sys/cpu.h> 33 #include <sys/device.h> 34 #include <sys/file.h> 35 #include <sys/ioctl.h> 36 #include <sys/kauth.h> 37 #include <sys/kmem.h> 38 #include <sys/lwp.h> 39 #include <sys/mbuf.h> 40 #include <sys/module.h> 41 #include <sys/mutex.h> 42 #include <sys/poll.h> 43 #include <sys/select.h> 44 #include <sys/signalvar.h> 45 #include <sys/socket.h> 46 47 #include <net/bpf.h> 48 #include <net/if.h> 49 #include <net/if_types.h> 50 #include <net/route.h> 51 52 #ifdef INET 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/in_var.h> 56 #include <netinet/ip.h> 57 #include <netinet/if_inarp.h> 58 #endif 59 60 #include <net/if_tun.h> 61 62 #include "ioconf.h" 63 64 #define TUNDEBUG if (tundebug) printf 65 int tundebug = 0; 66 67 extern int ifqmaxlen; 68 69 static LIST_HEAD(, tun_softc) tun_softc_list; 70 static LIST_HEAD(, tun_softc) tunz_softc_list; 71 static kmutex_t tun_softc_lock; 72 73 static int tun_ioctl(struct ifnet *, u_long, void *); 74 static int tun_output(struct ifnet *, struct mbuf *, 75 const struct sockaddr *, const struct rtentry *rt); 76 static int tun_clone_create(struct if_clone *, int); 77 static int tun_clone_destroy(struct ifnet *); 78 79 static struct if_clone tun_cloner = 80 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 81 82 static void tunattach0(struct tun_softc *); 83 static void tun_enable(struct tun_softc *, const struct ifaddr *); 84 static void tun_i_softintr(void *); 85 static void tun_o_softintr(void *); 86 #ifdef ALTQ 87 static void tunstart(struct ifnet *); 88 #endif 89 static struct tun_softc *tun_find_unit(dev_t); 90 static struct tun_softc *tun_find_zunit(int); 91 92 static dev_type_open(tunopen); 93 static dev_type_close(tunclose); 94 static dev_type_read(tunread); 95 static dev_type_write(tunwrite); 96 static dev_type_ioctl(tunioctl); 97 static dev_type_poll(tunpoll); 98 static dev_type_kqfilter(tunkqfilter); 99 100 const struct cdevsw tun_cdevsw = { 101 .d_open = tunopen, 102 .d_close = tunclose, 103 .d_read = tunread, 104 .d_write = tunwrite, 105 .d_ioctl = tunioctl, 106 .d_stop = nostop, 107 .d_tty = notty, 108 .d_poll = tunpoll, 109 .d_mmap = nommap, 110 .d_kqfilter = tunkqfilter, 111 .d_discard = nodiscard, 112 .d_flag = D_OTHER | D_MPSAFE 113 }; 114 115 #ifdef _MODULE 116 devmajor_t tun_bmajor = -1, tun_cmajor = -1; 117 #endif 118 119 void 120 tunattach(int unused) 121 { 122 123 /* 124 * Nothing to do here, initialization is handled by the 125 * module initialization code in tuninit() below). 126 */ 127 } 128 129 static void 130 tuninit(void) 131 { 132 133 mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NET); 134 LIST_INIT(&tun_softc_list); 135 LIST_INIT(&tunz_softc_list); 136 if_clone_attach(&tun_cloner); 137 #ifdef _MODULE 138 devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); 139 #endif 140 } 141 142 static int 143 tundetach(void) 144 { 145 int error = 0; 146 147 if (!LIST_EMPTY(&tun_softc_list) || !LIST_EMPTY(&tunz_softc_list)) 148 error = EBUSY; 149 150 #ifdef _MODULE 151 if (error == 0) 152 error = devsw_detach(NULL, &tun_cdevsw); 153 #endif 154 if (error == 0) { 155 if_clone_detach(&tun_cloner); 156 mutex_destroy(&tun_softc_lock); 157 } 158 159 return error; 160 } 161 162 /* 163 * Find driver instance from dev_t. 164 * Returns with tp locked (if found). 165 */ 166 static struct tun_softc * 167 tun_find_unit(dev_t dev) 168 { 169 struct tun_softc *tp; 170 int unit = minor(dev); 171 172 mutex_enter(&tun_softc_lock); 173 LIST_FOREACH(tp, &tun_softc_list, tun_list) 174 if (unit == tp->tun_unit) 175 break; 176 if (tp) 177 mutex_enter(&tp->tun_lock); 178 mutex_exit(&tun_softc_lock); 179 180 return tp; 181 } 182 183 /* 184 * Find zombie driver instance by unit number. 185 * Remove tp from list and return it unlocked (if found). 186 */ 187 static struct tun_softc * 188 tun_find_zunit(int unit) 189 { 190 struct tun_softc *tp; 191 192 mutex_enter(&tun_softc_lock); 193 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 194 if (unit == tp->tun_unit) 195 break; 196 if (tp) 197 LIST_REMOVE(tp, tun_list); 198 mutex_exit(&tun_softc_lock); 199 KASSERTMSG(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) == TUN_OPEN, 200 "tun%d: inconsistent flags: %x", unit, tp->tun_flags); 201 202 return tp; 203 } 204 205 static int 206 tun_clone_create(struct if_clone *ifc, int unit) 207 { 208 struct tun_softc *tp; 209 210 if ((tp = tun_find_zunit(unit)) == NULL) { 211 tp = kmem_zalloc(sizeof(*tp), KM_SLEEP); 212 213 tp->tun_unit = unit; 214 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 215 cv_init(&tp->tun_cv, "tunread"); 216 selinit(&tp->tun_rsel); 217 selinit(&tp->tun_wsel); 218 } else { 219 /* Revive tunnel instance; clear ifp part */ 220 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 221 } 222 223 if_initname(&tp->tun_if, ifc->ifc_name, unit); 224 tunattach0(tp); 225 tp->tun_flags |= TUN_INITED; 226 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 227 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 228 229 mutex_enter(&tun_softc_lock); 230 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 231 mutex_exit(&tun_softc_lock); 232 233 return 0; 234 } 235 236 static void 237 tunattach0(struct tun_softc *tp) 238 { 239 struct ifnet *ifp; 240 241 ifp = &tp->tun_if; 242 ifp->if_softc = tp; 243 ifp->if_mtu = TUNMTU; 244 ifp->if_ioctl = tun_ioctl; 245 ifp->if_output = tun_output; 246 #ifdef ALTQ 247 ifp->if_start = tunstart; 248 #endif 249 ifp->if_flags = IFF_POINTOPOINT; 250 ifp->if_type = IFT_TUNNEL; 251 ifp->if_snd.ifq_maxlen = ifqmaxlen; 252 ifp->if_collisions = 0; 253 ifp->if_ierrors = 0; 254 ifp->if_oerrors = 0; 255 ifp->if_ipackets = 0; 256 ifp->if_opackets = 0; 257 ifp->if_ibytes = 0; 258 ifp->if_obytes = 0; 259 ifp->if_dlt = DLT_NULL; 260 IFQ_SET_READY(&ifp->if_snd); 261 if_attach(ifp); 262 if_alloc_sadl(ifp); 263 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 264 } 265 266 static int 267 tun_clone_destroy(struct ifnet *ifp) 268 { 269 struct tun_softc *tp = (void *)ifp; 270 bool zombie = false; 271 272 IF_PURGE(&ifp->if_snd); 273 ifp->if_flags &= ~IFF_RUNNING; 274 275 mutex_enter(&tun_softc_lock); 276 mutex_enter(&tp->tun_lock); 277 LIST_REMOVE(tp, tun_list); 278 if (tp->tun_flags & TUN_OPEN) { 279 /* Hang on to storage until last close. */ 280 tp->tun_flags &= ~TUN_INITED; 281 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 282 zombie = true; 283 } 284 mutex_exit(&tun_softc_lock); 285 286 if (tp->tun_flags & TUN_RWAIT) { 287 tp->tun_flags &= ~TUN_RWAIT; 288 cv_broadcast(&tp->tun_cv); 289 } 290 selnotify(&tp->tun_rsel, 0, 0); 291 292 mutex_exit(&tp->tun_lock); 293 294 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 295 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 296 297 bpf_detach(ifp); 298 if_detach(ifp); 299 300 if (!zombie) { 301 seldestroy(&tp->tun_rsel); 302 seldestroy(&tp->tun_wsel); 303 softint_disestablish(tp->tun_osih); 304 softint_disestablish(tp->tun_isih); 305 mutex_destroy(&tp->tun_lock); 306 kmem_free(tp, sizeof(*tp)); 307 } 308 309 return 0; 310 } 311 312 /* 313 * tunnel open - must be superuser & the device must be 314 * configured in 315 */ 316 static int 317 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 318 { 319 struct ifnet *ifp; 320 struct tun_softc *tp; 321 int error; 322 323 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 324 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 325 if (error) 326 return error; 327 328 tp = tun_find_unit(dev); 329 330 if (tp == NULL) { 331 (void)tun_clone_create(&tun_cloner, minor(dev)); 332 tp = tun_find_unit(dev); 333 if (tp == NULL) { 334 return ENXIO; 335 } 336 } 337 338 if (tp->tun_flags & TUN_OPEN) { 339 mutex_exit(&tp->tun_lock); 340 return EBUSY; 341 } 342 343 ifp = &tp->tun_if; 344 tp->tun_flags |= TUN_OPEN; 345 TUNDEBUG("%s: open\n", ifp->if_xname); 346 347 mutex_exit(&tp->tun_lock); 348 349 return error; 350 } 351 352 /* 353 * tunclose - close the device - mark i/f down & delete 354 * routing info 355 */ 356 int 357 tunclose(dev_t dev, int flag, int mode, 358 struct lwp *l) 359 { 360 struct tun_softc *tp; 361 struct ifnet *ifp; 362 363 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 364 /* interface was "destroyed" before the close */ 365 seldestroy(&tp->tun_rsel); 366 seldestroy(&tp->tun_wsel); 367 softint_disestablish(tp->tun_osih); 368 softint_disestablish(tp->tun_isih); 369 mutex_destroy(&tp->tun_lock); 370 kmem_free(tp, sizeof(*tp)); 371 return 0; 372 } 373 374 if ((tp = tun_find_unit(dev)) == NULL) 375 goto out_nolock; 376 377 ifp = &tp->tun_if; 378 379 tp->tun_flags &= ~TUN_OPEN; 380 381 tp->tun_pgid = 0; 382 selnotify(&tp->tun_rsel, 0, 0); 383 384 TUNDEBUG ("%s: closed\n", ifp->if_xname); 385 mutex_exit(&tp->tun_lock); 386 387 /* 388 * junk all pending output 389 */ 390 IFQ_PURGE(&ifp->if_snd); 391 392 if (ifp->if_flags & IFF_UP) { 393 if_down(ifp); 394 if (ifp->if_flags & IFF_RUNNING) { 395 /* find internet addresses and delete routes */ 396 struct ifaddr *ifa; 397 IFADDR_READER_FOREACH(ifa, ifp) { 398 #if defined(INET) || defined(INET6) 399 if (ifa->ifa_addr->sa_family == AF_INET || 400 ifa->ifa_addr->sa_family == AF_INET6) { 401 rtinit(ifa, (int)RTM_DELETE, 402 tp->tun_flags & TUN_DSTADDR 403 ? RTF_HOST 404 : 0); 405 } 406 #endif 407 } 408 } 409 } 410 out_nolock: 411 return 0; 412 } 413 414 static void 415 tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) 416 { 417 struct ifnet *ifp = &tp->tun_if; 418 419 TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); 420 421 mutex_enter(&tp->tun_lock); 422 ifp->if_flags |= IFF_UP | IFF_RUNNING; 423 424 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 425 426 switch (ifa->ifa_addr->sa_family) { 427 #ifdef INET 428 case AF_INET: { 429 struct sockaddr_in *sin; 430 431 sin = satosin(ifa->ifa_addr); 432 if (sin && sin->sin_addr.s_addr) 433 tp->tun_flags |= TUN_IASET; 434 435 if (ifp->if_flags & IFF_POINTOPOINT) { 436 sin = satosin(ifa->ifa_dstaddr); 437 if (sin && sin->sin_addr.s_addr) 438 tp->tun_flags |= TUN_DSTADDR; 439 } 440 break; 441 } 442 #endif 443 #ifdef INET6 444 case AF_INET6: { 445 struct sockaddr_in6 *sin; 446 447 sin = satosin6(ifa->ifa_addr); 448 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 449 tp->tun_flags |= TUN_IASET; 450 451 if (ifp->if_flags & IFF_POINTOPOINT) { 452 sin = satosin6(ifa->ifa_dstaddr); 453 if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 454 tp->tun_flags |= TUN_DSTADDR; 455 } else 456 tp->tun_flags &= ~TUN_DSTADDR; 457 break; 458 } 459 #endif /* INET6 */ 460 default: 461 break; 462 } 463 mutex_exit(&tp->tun_lock); 464 } 465 466 /* 467 * Process an ioctl request. 468 */ 469 static int 470 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 471 { 472 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 473 struct ifreq *ifr = (struct ifreq *)data; 474 struct ifaddr *ifa = (struct ifaddr *)data; 475 int error = 0; 476 477 switch (cmd) { 478 case SIOCINITIFADDR: 479 tun_enable(tp, ifa); 480 ifa->ifa_rtrequest = p2p_rtrequest; 481 TUNDEBUG("%s: address set\n", ifp->if_xname); 482 break; 483 case SIOCSIFBRDADDR: 484 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 485 break; 486 case SIOCSIFMTU: 487 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 488 error = EINVAL; 489 break; 490 } 491 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 492 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 493 error = 0; 494 break; 495 case SIOCADDMULTI: 496 case SIOCDELMULTI: 497 if (ifr == NULL) { 498 error = EAFNOSUPPORT; /* XXX */ 499 break; 500 } 501 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 502 #ifdef INET 503 case AF_INET: 504 break; 505 #endif 506 #ifdef INET6 507 case AF_INET6: 508 break; 509 #endif 510 default: 511 error = EAFNOSUPPORT; 512 break; 513 } 514 break; 515 default: 516 error = ifioctl_common(ifp, cmd, data); 517 } 518 519 return error; 520 } 521 522 /* 523 * tun_output - queue packets from higher level ready to put out. 524 */ 525 static int 526 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 527 const struct rtentry *rt) 528 { 529 struct tun_softc *tp = ifp->if_softc; 530 int error; 531 #if defined(INET) || defined(INET6) 532 int mlen; 533 uint32_t *af; 534 #endif 535 536 mutex_enter(&tp->tun_lock); 537 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 538 539 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 540 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 541 tp->tun_flags); 542 error = EHOSTDOWN; 543 mutex_exit(&tp->tun_lock); 544 goto out; 545 } 546 // XXXrmind 547 mutex_exit(&tp->tun_lock); 548 549 /* 550 * if the queueing discipline needs packet classification, 551 * do it before prepending link headers. 552 */ 553 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); 554 555 bpf_mtap_af(ifp, dst->sa_family, m0); 556 557 switch(dst->sa_family) { 558 #ifdef INET6 559 case AF_INET6: 560 #endif 561 #ifdef INET 562 case AF_INET: 563 #endif 564 #if defined(INET) || defined(INET6) 565 if (tp->tun_flags & TUN_PREPADDR) { 566 /* Simple link-layer header */ 567 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 568 if (m0 == NULL) { 569 IF_DROP(&ifp->if_snd); 570 error = ENOBUFS; 571 goto out; 572 } 573 memcpy(mtod(m0, char *), dst, dst->sa_len); 574 } 575 576 if (tp->tun_flags & TUN_IFHEAD) { 577 /* Prepend the address family */ 578 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 579 if (m0 == NULL) { 580 IF_DROP(&ifp->if_snd); 581 error = ENOBUFS; 582 goto out; 583 } 584 af = mtod(m0,uint32_t *); 585 *af = htonl(dst->sa_family); 586 } else { 587 #ifdef INET 588 if (dst->sa_family != AF_INET) 589 #endif 590 { 591 error = EAFNOSUPPORT; 592 goto out; 593 } 594 } 595 /* FALLTHROUGH */ 596 case AF_UNSPEC: 597 IFQ_ENQUEUE(&ifp->if_snd, m0, error); 598 if (error) { 599 ifp->if_collisions++; 600 error = EAFNOSUPPORT; 601 m0 = NULL; 602 goto out; 603 } 604 mlen = m0->m_pkthdr.len; 605 ifp->if_opackets++; 606 ifp->if_obytes += mlen; 607 break; 608 #endif 609 default: 610 error = EAFNOSUPPORT; 611 goto out; 612 } 613 614 mutex_enter(&tp->tun_lock); 615 if (tp->tun_flags & TUN_RWAIT) { 616 tp->tun_flags &= ~TUN_RWAIT; 617 cv_broadcast(&tp->tun_cv); 618 } 619 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 620 softint_schedule(tp->tun_isih); 621 622 selnotify(&tp->tun_rsel, 0, 0); 623 624 mutex_exit(&tp->tun_lock); 625 out: 626 if (error && m0) { 627 m_freem(m0); 628 } 629 return 0; 630 } 631 632 static void 633 tun_i_softintr(void *cookie) 634 { 635 struct tun_softc *tp = cookie; 636 637 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 638 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 639 NULL); 640 } 641 642 static void 643 tun_o_softintr(void *cookie) 644 { 645 struct tun_softc *tp = cookie; 646 647 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 648 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 649 NULL); 650 } 651 652 /* 653 * the cdevsw interface is now pretty minimal. 654 */ 655 int 656 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 657 { 658 struct tun_softc *tp; 659 int error = 0; 660 661 tp = tun_find_unit(dev); 662 663 /* interface was "destroyed" already */ 664 if (tp == NULL) { 665 return ENXIO; 666 } 667 668 switch (cmd) { 669 case TUNSDEBUG: 670 tundebug = *(int *)data; 671 break; 672 673 case TUNGDEBUG: 674 *(int *)data = tundebug; 675 break; 676 677 case TUNSIFMODE: 678 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 679 case IFF_POINTOPOINT: 680 case IFF_BROADCAST: 681 if (tp->tun_if.if_flags & IFF_UP) { 682 error = EBUSY; 683 goto out; 684 } 685 tp->tun_if.if_flags &= 686 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 687 tp->tun_if.if_flags |= *(int *)data; 688 break; 689 default: 690 error = EINVAL; 691 goto out; 692 } 693 break; 694 695 case TUNSLMODE: 696 if (*(int *)data) { 697 tp->tun_flags |= TUN_PREPADDR; 698 tp->tun_flags &= ~TUN_IFHEAD; 699 } else 700 tp->tun_flags &= ~TUN_PREPADDR; 701 break; 702 703 case TUNSIFHEAD: 704 if (*(int *)data) { 705 tp->tun_flags |= TUN_IFHEAD; 706 tp->tun_flags &= ~TUN_PREPADDR; 707 } else 708 tp->tun_flags &= ~TUN_IFHEAD; 709 break; 710 711 case TUNGIFHEAD: 712 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 713 break; 714 715 case FIONBIO: 716 if (*(int *)data) 717 tp->tun_flags |= TUN_NBIO; 718 else 719 tp->tun_flags &= ~TUN_NBIO; 720 break; 721 722 case FIOASYNC: 723 if (*(int *)data) 724 tp->tun_flags |= TUN_ASYNC; 725 else 726 tp->tun_flags &= ~TUN_ASYNC; 727 break; 728 729 case FIONREAD: 730 if (tp->tun_if.if_snd.ifq_head) 731 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 732 else 733 *(int *)data = 0; 734 break; 735 736 case TIOCSPGRP: 737 case FIOSETOWN: 738 error = fsetown(&tp->tun_pgid, cmd, data); 739 break; 740 741 case TIOCGPGRP: 742 case FIOGETOWN: 743 error = fgetown(tp->tun_pgid, cmd, data); 744 break; 745 746 default: 747 error = ENOTTY; 748 } 749 750 out: 751 mutex_exit(&tp->tun_lock); 752 753 return error; 754 } 755 756 /* 757 * The cdevsw read interface - reads a packet at a time, or at 758 * least as much of a packet as can be read. 759 */ 760 int 761 tunread(dev_t dev, struct uio *uio, int ioflag) 762 { 763 struct tun_softc *tp; 764 struct ifnet *ifp; 765 struct mbuf *m, *m0; 766 int error = 0, len; 767 768 tp = tun_find_unit(dev); 769 770 /* interface was "destroyed" already */ 771 if (tp == NULL) { 772 return ENXIO; 773 } 774 775 ifp = &tp->tun_if; 776 777 TUNDEBUG ("%s: read\n", ifp->if_xname); 778 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 779 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 780 error = EHOSTDOWN; 781 goto out; 782 } 783 784 tp->tun_flags &= ~TUN_RWAIT; 785 786 do { 787 IFQ_DEQUEUE(&ifp->if_snd, m0); 788 if (m0 == 0) { 789 if (tp->tun_flags & TUN_NBIO) { 790 error = EWOULDBLOCK; 791 goto out; 792 } 793 tp->tun_flags |= TUN_RWAIT; 794 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 795 error = EINTR; 796 goto out; 797 } 798 } 799 } while (m0 == 0); 800 801 mutex_exit(&tp->tun_lock); 802 803 /* Copy the mbuf chain */ 804 while (m0 && uio->uio_resid > 0 && error == 0) { 805 len = min(uio->uio_resid, m0->m_len); 806 if (len != 0) 807 error = uiomove(mtod(m0, void *), len, uio); 808 m0 = m = m_free(m0); 809 } 810 811 if (m0) { 812 TUNDEBUG("Dropping mbuf\n"); 813 m_freem(m0); 814 } 815 if (error) 816 ifp->if_ierrors++; 817 818 return error; 819 820 out: 821 mutex_exit(&tp->tun_lock); 822 823 return error; 824 } 825 826 /* 827 * the cdevsw write interface - an atomic write is a packet - or else! 828 */ 829 int 830 tunwrite(dev_t dev, struct uio *uio, int ioflag) 831 { 832 struct tun_softc *tp; 833 struct ifnet *ifp; 834 struct mbuf *top, **mp, *m; 835 pktqueue_t *pktq; 836 struct sockaddr dst; 837 int error = 0, tlen, mlen; 838 uint32_t family; 839 840 tp = tun_find_unit(dev); 841 if (tp == NULL) { 842 /* Interface was "destroyed" already. */ 843 return ENXIO; 844 } 845 846 /* Unlock until we've got the data */ 847 mutex_exit(&tp->tun_lock); 848 849 ifp = &tp->tun_if; 850 851 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 852 853 if (tp->tun_flags & TUN_PREPADDR) { 854 if (uio->uio_resid < sizeof(dst)) { 855 error = EIO; 856 goto out0; 857 } 858 error = uiomove((void *)&dst, sizeof(dst), uio); 859 if (dst.sa_len > sizeof(dst)) { 860 /* Duh.. */ 861 int n = dst.sa_len - sizeof(dst); 862 while (n--) { 863 char discard; 864 error = uiomove(&discard, 1, uio); 865 if (error) { 866 goto out0; 867 } 868 } 869 } 870 } else if (tp->tun_flags & TUN_IFHEAD) { 871 if (uio->uio_resid < sizeof(family)){ 872 error = EIO; 873 goto out0; 874 } 875 error = uiomove((void *)&family, sizeof(family), uio); 876 dst.sa_family = ntohl(family); 877 } else { 878 #ifdef INET 879 dst.sa_family = AF_INET; 880 #endif 881 } 882 883 if (uio->uio_resid > TUNMTU) { 884 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 885 (unsigned long)uio->uio_resid); 886 error = EIO; 887 goto out0; 888 } 889 890 switch (dst.sa_family) { 891 #ifdef INET 892 case AF_INET: 893 pktq = ip_pktq; 894 break; 895 #endif 896 #ifdef INET6 897 case AF_INET6: 898 pktq = ip6_pktq; 899 break; 900 #endif 901 default: 902 error = EAFNOSUPPORT; 903 goto out0; 904 } 905 906 tlen = uio->uio_resid; 907 908 /* get a header mbuf */ 909 MGETHDR(m, M_DONTWAIT, MT_DATA); 910 if (m == NULL) { 911 return ENOBUFS; 912 } 913 mlen = MHLEN; 914 915 top = NULL; 916 mp = ⊤ 917 while (error == 0 && uio->uio_resid > 0) { 918 m->m_len = min(mlen, uio->uio_resid); 919 error = uiomove(mtod(m, void *), m->m_len, uio); 920 *mp = m; 921 mp = &m->m_next; 922 if (error == 0 && uio->uio_resid > 0) { 923 MGET(m, M_DONTWAIT, MT_DATA); 924 if (m == NULL) { 925 error = ENOBUFS; 926 break; 927 } 928 mlen = MLEN; 929 } 930 } 931 if (error) { 932 if (top != NULL) 933 m_freem(top); 934 ifp->if_ierrors++; 935 goto out0; 936 } 937 938 top->m_pkthdr.len = tlen; 939 m_set_rcvif(top, ifp); 940 941 bpf_mtap_af(ifp, dst.sa_family, top); 942 943 mutex_enter(&tp->tun_lock); 944 if ((tp->tun_flags & TUN_INITED) == 0) { 945 /* Interface was destroyed */ 946 error = ENXIO; 947 goto out; 948 } 949 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 950 ifp->if_collisions++; 951 mutex_exit(&tp->tun_lock); 952 error = ENOBUFS; 953 m_freem(top); 954 goto out0; 955 } 956 ifp->if_ipackets++; 957 ifp->if_ibytes += tlen; 958 out: 959 mutex_exit(&tp->tun_lock); 960 out0: 961 return error; 962 } 963 964 #ifdef ALTQ 965 /* 966 * Start packet transmission on the interface. 967 * when the interface queue is rate-limited by ALTQ or TBR, 968 * if_start is needed to drain packets from the queue in order 969 * to notify readers when outgoing packets become ready. 970 */ 971 static void 972 tunstart(struct ifnet *ifp) 973 { 974 struct tun_softc *tp = ifp->if_softc; 975 976 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 977 return; 978 979 mutex_enter(&tp->tun_lock); 980 if (!IF_IS_EMPTY(&ifp->if_snd)) { 981 if (tp->tun_flags & TUN_RWAIT) { 982 tp->tun_flags &= ~TUN_RWAIT; 983 cv_broadcast(&tp->tun_cv); 984 } 985 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 986 softint_schedule(tp->tun_osih); 987 988 selnotify(&tp->tun_rsel, 0, 0); 989 } 990 mutex_exit(&tp->tun_lock); 991 } 992 #endif /* ALTQ */ 993 /* 994 * tunpoll - the poll interface, this is only useful on reads 995 * really. The write detect always returns true, write never blocks 996 * anyway, it either accepts the packet or drops it. 997 */ 998 int 999 tunpoll(dev_t dev, int events, struct lwp *l) 1000 { 1001 struct tun_softc *tp; 1002 struct ifnet *ifp; 1003 int revents = 0; 1004 1005 tp = tun_find_unit(dev); 1006 if (tp == NULL) { 1007 /* Interface was "destroyed" already. */ 1008 return 0; 1009 } 1010 ifp = &tp->tun_if; 1011 1012 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1013 1014 if (events & (POLLIN | POLLRDNORM)) { 1015 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1016 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1017 ifp->if_snd.ifq_len); 1018 revents |= events & (POLLIN | POLLRDNORM); 1019 } else { 1020 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1021 selrecord(l, &tp->tun_rsel); 1022 } 1023 } 1024 1025 if (events & (POLLOUT | POLLWRNORM)) 1026 revents |= events & (POLLOUT | POLLWRNORM); 1027 1028 mutex_exit(&tp->tun_lock); 1029 1030 return revents; 1031 } 1032 1033 static void 1034 filt_tunrdetach(struct knote *kn) 1035 { 1036 struct tun_softc *tp = kn->kn_hook; 1037 1038 mutex_enter(&tp->tun_lock); 1039 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1040 mutex_exit(&tp->tun_lock); 1041 } 1042 1043 static int 1044 filt_tunread(struct knote *kn, long hint) 1045 { 1046 struct tun_softc *tp = kn->kn_hook; 1047 struct ifnet *ifp = &tp->tun_if; 1048 struct mbuf *m; 1049 1050 mutex_enter(&tp->tun_lock); 1051 IF_POLL(&ifp->if_snd, m); 1052 if (m == NULL) { 1053 mutex_exit(&tp->tun_lock); 1054 return 0; 1055 } 1056 1057 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1058 kn->kn_data += m->m_len; 1059 1060 mutex_exit(&tp->tun_lock); 1061 1062 return 1; 1063 } 1064 1065 static const struct filterops tunread_filtops = 1066 { 1, NULL, filt_tunrdetach, filt_tunread }; 1067 1068 static const struct filterops tun_seltrue_filtops = 1069 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1070 1071 int 1072 tunkqfilter(dev_t dev, struct knote *kn) 1073 { 1074 struct tun_softc *tp; 1075 struct klist *klist; 1076 int rv = 0; 1077 1078 tp = tun_find_unit(dev); 1079 if (tp == NULL) 1080 goto out_nolock; 1081 1082 switch (kn->kn_filter) { 1083 case EVFILT_READ: 1084 klist = &tp->tun_rsel.sel_klist; 1085 kn->kn_fop = &tunread_filtops; 1086 break; 1087 1088 case EVFILT_WRITE: 1089 klist = &tp->tun_rsel.sel_klist; 1090 kn->kn_fop = &tun_seltrue_filtops; 1091 break; 1092 1093 default: 1094 rv = EINVAL; 1095 goto out; 1096 } 1097 1098 kn->kn_hook = tp; 1099 1100 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1101 1102 out: 1103 mutex_exit(&tp->tun_lock); 1104 out_nolock: 1105 return rv; 1106 } 1107 1108 /* 1109 * Module infrastructure 1110 */ 1111 #include "if_module.h" 1112 1113 IF_MODULE(MODULE_CLASS_DRIVER, tun, "") 1114
Indexes created Tue Sep 23 14:10:03 GMT 2025