1 /* $NetBSD: if_tun.c,v 1.123 2015/08/24 22:21:26 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 1988, Julian Onions <jpo@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 #include <sys/cdefs.h> 18 __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.123 2015/08/24 22:21:26 pooka Exp $"); 19 20 #ifdef _KERNEL_OPT 21 #include "opt_inet.h" 22 #endif 23 24 #include <sys/param.h> 25 #include <sys/proc.h> 26 #include <sys/systm.h> 27 #include <sys/mbuf.h> 28 #include <sys/buf.h> 29 #include <sys/protosw.h> 30 #include <sys/socket.h> 31 #include <sys/ioctl.h> 32 #include <sys/errno.h> 33 #include <sys/syslog.h> 34 #include <sys/select.h> 35 #include <sys/poll.h> 36 #include <sys/file.h> 37 #include <sys/signalvar.h> 38 #include <sys/conf.h> 39 #include <sys/kauth.h> 40 #include <sys/mutex.h> 41 #include <sys/cpu.h> 42 43 #include <net/if.h> 44 #include <net/if_types.h> 45 #include <net/netisr.h> 46 #include <net/route.h> 47 48 49 #ifdef INET 50 #include <netinet/in.h> 51 #include <netinet/in_systm.h> 52 #include <netinet/in_var.h> 53 #include <netinet/ip.h> 54 #include <netinet/if_inarp.h> 55 #endif 56 57 58 #include <sys/time.h> 59 #include <net/bpf.h> 60 61 #include <net/if_tun.h> 62 63 #include "ioconf.h" 64 65 #define TUNDEBUG if (tundebug) printf 66 int tundebug = 0; 67 68 extern int ifqmaxlen; 69 70 static LIST_HEAD(, tun_softc) tun_softc_list; 71 static LIST_HEAD(, tun_softc) tunz_softc_list; 72 static kmutex_t tun_softc_lock; 73 74 static int tun_ioctl(struct ifnet *, u_long, void *); 75 static int tun_output(struct ifnet *, struct mbuf *, 76 const struct sockaddr *, struct rtentry *rt); 77 static int tun_clone_create(struct if_clone *, int); 78 static int tun_clone_destroy(struct ifnet *); 79 80 static struct if_clone tun_cloner = 81 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 82 83 static void tunattach0(struct tun_softc *); 84 static void tuninit(struct tun_softc *); 85 static void tun_i_softintr(void *); 86 static void tun_o_softintr(void *); 87 #ifdef ALTQ 88 static void tunstart(struct ifnet *); 89 #endif 90 static struct tun_softc *tun_find_unit(dev_t); 91 static struct tun_softc *tun_find_zunit(int); 92 93 static dev_type_open(tunopen); 94 static dev_type_close(tunclose); 95 static dev_type_read(tunread); 96 static dev_type_write(tunwrite); 97 static dev_type_ioctl(tunioctl); 98 static dev_type_poll(tunpoll); 99 static dev_type_kqfilter(tunkqfilter); 100 101 const struct cdevsw tun_cdevsw = { 102 .d_open = tunopen, 103 .d_close = tunclose, 104 .d_read = tunread, 105 .d_write = tunwrite, 106 .d_ioctl = tunioctl, 107 .d_stop = nostop, 108 .d_tty = notty, 109 .d_poll = tunpoll, 110 .d_mmap = nommap, 111 .d_kqfilter = tunkqfilter, 112 .d_discard = nodiscard, 113 .d_flag = D_OTHER 114 }; 115 116 void 117 tunattach(int unused) 118 { 119 120 mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NET); 121 LIST_INIT(&tun_softc_list); 122 LIST_INIT(&tunz_softc_list); 123 if_clone_attach(&tun_cloner); 124 } 125 126 /* 127 * Find driver instance from dev_t. 128 * Returns with tp locked (if found). 129 */ 130 static struct tun_softc * 131 tun_find_unit(dev_t dev) 132 { 133 struct tun_softc *tp; 134 int unit = minor(dev); 135 136 mutex_enter(&tun_softc_lock); 137 LIST_FOREACH(tp, &tun_softc_list, tun_list) 138 if (unit == tp->tun_unit) 139 break; 140 if (tp) 141 mutex_enter(&tp->tun_lock); 142 mutex_exit(&tun_softc_lock); 143 144 return (tp); 145 } 146 147 /* 148 * Find zombie driver instance by unit number. 149 * Remove tp from list and return it unlocked (if found). 150 */ 151 static struct tun_softc * 152 tun_find_zunit(int unit) 153 { 154 struct tun_softc *tp; 155 156 mutex_enter(&tun_softc_lock); 157 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 158 if (unit == tp->tun_unit) 159 break; 160 if (tp) 161 LIST_REMOVE(tp, tun_list); 162 mutex_exit(&tun_softc_lock); 163 #ifdef DIAGNOSTIC 164 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 165 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 166 #endif 167 168 return (tp); 169 } 170 171 static int 172 tun_clone_create(struct if_clone *ifc, int unit) 173 { 174 struct tun_softc *tp; 175 176 if ((tp = tun_find_zunit(unit)) == NULL) { 177 /* Allocate a new instance */ 178 tp = malloc(sizeof(*tp), M_DEVBUF, M_WAITOK|M_ZERO); 179 180 tp->tun_unit = unit; 181 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 182 selinit(&tp->tun_rsel); 183 selinit(&tp->tun_wsel); 184 } else { 185 /* Revive tunnel instance; clear ifp part */ 186 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 187 } 188 189 if_initname(&tp->tun_if, ifc->ifc_name, unit); 190 tunattach0(tp); 191 tp->tun_flags |= TUN_INITED; 192 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 193 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 194 195 mutex_enter(&tun_softc_lock); 196 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 197 mutex_exit(&tun_softc_lock); 198 199 return (0); 200 } 201 202 static void 203 tunattach0(struct tun_softc *tp) 204 { 205 struct ifnet *ifp; 206 207 ifp = &tp->tun_if; 208 ifp->if_softc = tp; 209 ifp->if_mtu = TUNMTU; 210 ifp->if_ioctl = tun_ioctl; 211 ifp->if_output = tun_output; 212 #ifdef ALTQ 213 ifp->if_start = tunstart; 214 #endif 215 ifp->if_flags = IFF_POINTOPOINT; 216 ifp->if_type = IFT_TUNNEL; 217 ifp->if_snd.ifq_maxlen = ifqmaxlen; 218 ifp->if_collisions = 0; 219 ifp->if_ierrors = 0; 220 ifp->if_oerrors = 0; 221 ifp->if_ipackets = 0; 222 ifp->if_opackets = 0; 223 ifp->if_ibytes = 0; 224 ifp->if_obytes = 0; 225 ifp->if_dlt = DLT_NULL; 226 IFQ_SET_READY(&ifp->if_snd); 227 if_attach(ifp); 228 if_alloc_sadl(ifp); 229 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 230 } 231 232 static int 233 tun_clone_destroy(struct ifnet *ifp) 234 { 235 struct tun_softc *tp = (void *)ifp; 236 int zombie = 0; 237 238 IF_PURGE(&ifp->if_snd); 239 ifp->if_flags &= ~IFF_RUNNING; 240 241 mutex_enter(&tun_softc_lock); 242 mutex_enter(&tp->tun_lock); 243 LIST_REMOVE(tp, tun_list); 244 if (tp->tun_flags & TUN_OPEN) { 245 /* Hang on to storage until last close */ 246 zombie = 1; 247 tp->tun_flags &= ~TUN_INITED; 248 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 249 } 250 mutex_exit(&tun_softc_lock); 251 252 if (tp->tun_flags & TUN_RWAIT) { 253 tp->tun_flags &= ~TUN_RWAIT; 254 wakeup((void *)tp); 255 } 256 selnotify(&tp->tun_rsel, 0, 0); 257 258 mutex_exit(&tp->tun_lock); 259 260 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 261 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 262 263 bpf_detach(ifp); 264 if_detach(ifp); 265 266 if (!zombie) { 267 seldestroy(&tp->tun_rsel); 268 seldestroy(&tp->tun_wsel); 269 softint_disestablish(tp->tun_osih); 270 softint_disestablish(tp->tun_isih); 271 mutex_destroy(&tp->tun_lock); 272 free(tp, M_DEVBUF); 273 } 274 275 return (0); 276 } 277 278 /* 279 * tunnel open - must be superuser & the device must be 280 * configured in 281 */ 282 static int 283 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 284 { 285 struct ifnet *ifp; 286 struct tun_softc *tp; 287 int error; 288 289 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 290 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 291 if (error) 292 return (error); 293 294 tp = tun_find_unit(dev); 295 296 if (tp == NULL) { 297 (void)tun_clone_create(&tun_cloner, minor(dev)); 298 tp = tun_find_unit(dev); 299 if (tp == NULL) { 300 error = ENXIO; 301 goto out_nolock; 302 } 303 } 304 305 if (tp->tun_flags & TUN_OPEN) { 306 error = EBUSY; 307 goto out; 308 } 309 310 ifp = &tp->tun_if; 311 tp->tun_flags |= TUN_OPEN; 312 TUNDEBUG("%s: open\n", ifp->if_xname); 313 out: 314 mutex_exit(&tp->tun_lock); 315 out_nolock: 316 return (error); 317 } 318 319 /* 320 * tunclose - close the device - mark i/f down & delete 321 * routing info 322 */ 323 int 324 tunclose(dev_t dev, int flag, int mode, 325 struct lwp *l) 326 { 327 struct tun_softc *tp; 328 struct ifnet *ifp; 329 330 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 331 /* interface was "destroyed" before the close */ 332 seldestroy(&tp->tun_rsel); 333 seldestroy(&tp->tun_wsel); 334 softint_disestablish(tp->tun_osih); 335 softint_disestablish(tp->tun_isih); 336 mutex_destroy(&tp->tun_lock); 337 free(tp, M_DEVBUF); 338 goto out_nolock; 339 } 340 341 if ((tp = tun_find_unit(dev)) == NULL) 342 goto out_nolock; 343 344 ifp = &tp->tun_if; 345 346 tp->tun_flags &= ~TUN_OPEN; 347 348 tp->tun_pgid = 0; 349 selnotify(&tp->tun_rsel, 0, 0); 350 351 TUNDEBUG ("%s: closed\n", ifp->if_xname); 352 mutex_exit(&tp->tun_lock); 353 354 /* 355 * junk all pending output 356 */ 357 IFQ_PURGE(&ifp->if_snd); 358 359 if (ifp->if_flags & IFF_UP) { 360 if_down(ifp); 361 if (ifp->if_flags & IFF_RUNNING) { 362 /* find internet addresses and delete routes */ 363 struct ifaddr *ifa; 364 IFADDR_FOREACH(ifa, ifp) { 365 #if defined(INET) || defined(INET6) 366 if (ifa->ifa_addr->sa_family == AF_INET || 367 ifa->ifa_addr->sa_family == AF_INET6) { 368 rtinit(ifa, (int)RTM_DELETE, 369 tp->tun_flags & TUN_DSTADDR 370 ? RTF_HOST 371 : 0); 372 } 373 #endif 374 } 375 } 376 } 377 out_nolock: 378 return (0); 379 } 380 381 /* 382 * Call at splnet(). 383 */ 384 static void 385 tuninit(struct tun_softc *tp) 386 { 387 struct ifnet *ifp = &tp->tun_if; 388 struct ifaddr *ifa; 389 390 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 391 392 mutex_enter(&tp->tun_lock); 393 ifp->if_flags |= IFF_UP | IFF_RUNNING; 394 395 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 396 IFADDR_FOREACH(ifa, ifp) { 397 #ifdef INET 398 if (ifa->ifa_addr->sa_family == AF_INET) { 399 struct sockaddr_in *sin; 400 401 sin = satosin(ifa->ifa_addr); 402 if (sin && sin->sin_addr.s_addr) 403 tp->tun_flags |= TUN_IASET; 404 405 if (ifp->if_flags & IFF_POINTOPOINT) { 406 sin = satosin(ifa->ifa_dstaddr); 407 if (sin && sin->sin_addr.s_addr) 408 tp->tun_flags |= TUN_DSTADDR; 409 } 410 } 411 #endif 412 #ifdef INET6 413 if (ifa->ifa_addr->sa_family == AF_INET6) { 414 struct sockaddr_in6 *sin; 415 416 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 417 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 418 tp->tun_flags |= TUN_IASET; 419 420 if (ifp->if_flags & IFF_POINTOPOINT) { 421 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 422 if (sin && 423 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 424 tp->tun_flags |= TUN_DSTADDR; 425 } else 426 tp->tun_flags &= ~TUN_DSTADDR; 427 } 428 #endif /* INET6 */ 429 } 430 mutex_exit(&tp->tun_lock); 431 } 432 433 /* 434 * Process an ioctl request. 435 */ 436 static int 437 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 438 { 439 int error = 0, s; 440 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 441 struct ifreq *ifr = (struct ifreq *)data; 442 struct ifaddr *ifa = (struct ifaddr *)data; 443 444 s = splnet(); 445 446 switch (cmd) { 447 case SIOCINITIFADDR: 448 tuninit(tp); 449 ifa->ifa_rtrequest = p2p_rtrequest; 450 TUNDEBUG("%s: address set\n", ifp->if_xname); 451 break; 452 case SIOCSIFBRDADDR: 453 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 454 break; 455 case SIOCSIFMTU: 456 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 457 error = EINVAL; 458 break; 459 } 460 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 461 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 462 error = 0; 463 break; 464 case SIOCADDMULTI: 465 case SIOCDELMULTI: 466 if (ifr == NULL) { 467 error = EAFNOSUPPORT; /* XXX */ 468 break; 469 } 470 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 471 #ifdef INET 472 case AF_INET: 473 break; 474 #endif 475 #ifdef INET6 476 case AF_INET6: 477 break; 478 #endif 479 default: 480 error = EAFNOSUPPORT; 481 break; 482 } 483 break; 484 default: 485 error = ifioctl_common(ifp, cmd, data); 486 } 487 488 splx(s); 489 return (error); 490 } 491 492 /* 493 * tun_output - queue packets from higher level ready to put out. 494 */ 495 static int 496 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 497 struct rtentry *rt) 498 { 499 struct tun_softc *tp = ifp->if_softc; 500 int s; 501 int error; 502 #if defined(INET) || defined(INET6) 503 int mlen; 504 uint32_t *af; 505 #endif 506 ALTQ_DECL(struct altq_pktattr pktattr;) 507 508 s = splnet(); 509 mutex_enter(&tp->tun_lock); 510 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 511 512 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 513 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 514 tp->tun_flags); 515 error = EHOSTDOWN; 516 goto out; 517 } 518 519 /* 520 * if the queueing discipline needs packet classification, 521 * do it before prepending link headers. 522 */ 523 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 524 525 bpf_mtap_af(ifp, dst->sa_family, m0); 526 527 switch(dst->sa_family) { 528 #ifdef INET6 529 case AF_INET6: 530 #endif 531 #ifdef INET 532 case AF_INET: 533 #endif 534 #if defined(INET) || defined(INET6) 535 if (tp->tun_flags & TUN_PREPADDR) { 536 /* Simple link-layer header */ 537 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 538 if (m0 == NULL) { 539 IF_DROP(&ifp->if_snd); 540 error = ENOBUFS; 541 goto out; 542 } 543 bcopy(dst, mtod(m0, char *), dst->sa_len); 544 } 545 546 if (tp->tun_flags & TUN_IFHEAD) { 547 /* Prepend the address family */ 548 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 549 if (m0 == NULL) { 550 IF_DROP(&ifp->if_snd); 551 error = ENOBUFS; 552 goto out; 553 } 554 af = mtod(m0,uint32_t *); 555 *af = htonl(dst->sa_family); 556 } else { 557 #ifdef INET 558 if (dst->sa_family != AF_INET) 559 #endif 560 { 561 error = EAFNOSUPPORT; 562 goto out; 563 } 564 } 565 /* FALLTHROUGH */ 566 case AF_UNSPEC: 567 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 568 if (error) { 569 ifp->if_collisions++; 570 error = EAFNOSUPPORT; 571 m0 = NULL; 572 goto out; 573 } 574 mlen = m0->m_pkthdr.len; 575 ifp->if_opackets++; 576 ifp->if_obytes += mlen; 577 break; 578 #endif 579 default: 580 error = EAFNOSUPPORT; 581 goto out; 582 } 583 584 if (tp->tun_flags & TUN_RWAIT) { 585 tp->tun_flags &= ~TUN_RWAIT; 586 wakeup((void *)tp); 587 } 588 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 589 softint_schedule(tp->tun_isih); 590 591 selnotify(&tp->tun_rsel, 0, 0); 592 out: 593 mutex_exit(&tp->tun_lock); 594 splx(s); 595 596 if (error && m0) { 597 m_freem(m0); 598 } 599 return 0; 600 } 601 602 static void 603 tun_i_softintr(void *cookie) 604 { 605 struct tun_softc *tp = cookie; 606 607 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 608 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 609 NULL); 610 } 611 612 static void 613 tun_o_softintr(void *cookie) 614 { 615 struct tun_softc *tp = cookie; 616 617 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 618 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 619 NULL); 620 } 621 622 /* 623 * the cdevsw interface is now pretty minimal. 624 */ 625 int 626 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 627 { 628 struct tun_softc *tp; 629 int s, error = 0; 630 631 s = splnet(); 632 tp = tun_find_unit(dev); 633 634 /* interface was "destroyed" already */ 635 if (tp == NULL) { 636 error = ENXIO; 637 goto out_nolock; 638 } 639 640 switch (cmd) { 641 case TUNSDEBUG: 642 tundebug = *(int *)data; 643 break; 644 645 case TUNGDEBUG: 646 *(int *)data = tundebug; 647 break; 648 649 case TUNSIFMODE: 650 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 651 case IFF_POINTOPOINT: 652 case IFF_BROADCAST: 653 if (tp->tun_if.if_flags & IFF_UP) { 654 error = EBUSY; 655 goto out; 656 } 657 tp->tun_if.if_flags &= 658 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 659 tp->tun_if.if_flags |= *(int *)data; 660 break; 661 default: 662 error = EINVAL; 663 goto out; 664 } 665 break; 666 667 case TUNSLMODE: 668 if (*(int *)data) { 669 tp->tun_flags |= TUN_PREPADDR; 670 tp->tun_flags &= ~TUN_IFHEAD; 671 } else 672 tp->tun_flags &= ~TUN_PREPADDR; 673 break; 674 675 case TUNSIFHEAD: 676 if (*(int *)data) { 677 tp->tun_flags |= TUN_IFHEAD; 678 tp->tun_flags &= ~TUN_PREPADDR; 679 } else 680 tp->tun_flags &= ~TUN_IFHEAD; 681 break; 682 683 case TUNGIFHEAD: 684 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 685 break; 686 687 case FIONBIO: 688 if (*(int *)data) 689 tp->tun_flags |= TUN_NBIO; 690 else 691 tp->tun_flags &= ~TUN_NBIO; 692 break; 693 694 case FIOASYNC: 695 if (*(int *)data) 696 tp->tun_flags |= TUN_ASYNC; 697 else 698 tp->tun_flags &= ~TUN_ASYNC; 699 break; 700 701 case FIONREAD: 702 if (tp->tun_if.if_snd.ifq_head) 703 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 704 else 705 *(int *)data = 0; 706 break; 707 708 case TIOCSPGRP: 709 case FIOSETOWN: 710 error = fsetown(&tp->tun_pgid, cmd, data); 711 break; 712 713 case TIOCGPGRP: 714 case FIOGETOWN: 715 error = fgetown(tp->tun_pgid, cmd, data); 716 break; 717 718 default: 719 error = ENOTTY; 720 } 721 722 out: 723 mutex_exit(&tp->tun_lock); 724 out_nolock: 725 splx(s); 726 return (error); 727 } 728 729 /* 730 * The cdevsw read interface - reads a packet at a time, or at 731 * least as much of a packet as can be read. 732 */ 733 int 734 tunread(dev_t dev, struct uio *uio, int ioflag) 735 { 736 struct tun_softc *tp; 737 struct ifnet *ifp; 738 struct mbuf *m, *m0; 739 int error = 0, len, s, index; 740 741 s = splnet(); 742 tp = tun_find_unit(dev); 743 744 /* interface was "destroyed" already */ 745 if (tp == NULL) { 746 error = ENXIO; 747 goto out_nolock; 748 } 749 750 index = tp->tun_if.if_index; 751 ifp = &tp->tun_if; 752 753 TUNDEBUG ("%s: read\n", ifp->if_xname); 754 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 755 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 756 error = EHOSTDOWN; 757 goto out; 758 } 759 760 tp->tun_flags &= ~TUN_RWAIT; 761 762 do { 763 IFQ_DEQUEUE(&ifp->if_snd, m0); 764 if (m0 == 0) { 765 if (tp->tun_flags & TUN_NBIO) { 766 error = EWOULDBLOCK; 767 goto out; 768 } 769 tp->tun_flags |= TUN_RWAIT; 770 if (mtsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 771 "tunread", 0, &tp->tun_lock) != 0) { 772 error = EINTR; 773 goto out_nolock; 774 } else { 775 /* 776 * Maybe the interface was destroyed while 777 * we were sleeping, so let's ensure that 778 * we're looking at the same (valid) tun 779 * interface before looping. 780 */ 781 tp = tun_find_unit(dev); 782 if (tp == NULL) { 783 error = ENXIO; 784 goto out_nolock; 785 } 786 if (tp->tun_if.if_index != index) { 787 error = ENXIO; 788 goto out; 789 } 790 } 791 } 792 } while (m0 == 0); 793 794 mutex_exit(&tp->tun_lock); 795 splx(s); 796 797 /* Copy the mbuf chain */ 798 while (m0 && uio->uio_resid > 0 && error == 0) { 799 len = min(uio->uio_resid, m0->m_len); 800 if (len != 0) 801 error = uiomove(mtod(m0, void *), len, uio); 802 MFREE(m0, m); 803 m0 = m; 804 } 805 806 if (m0) { 807 TUNDEBUG("Dropping mbuf\n"); 808 m_freem(m0); 809 } 810 if (error) 811 ifp->if_ierrors++; 812 813 return (error); 814 815 out: 816 mutex_exit(&tp->tun_lock); 817 out_nolock: 818 splx(s); 819 return (error); 820 } 821 822 /* 823 * the cdevsw write interface - an atomic write is a packet - or else! 824 */ 825 int 826 tunwrite(dev_t dev, struct uio *uio, int ioflag) 827 { 828 struct tun_softc *tp; 829 struct ifnet *ifp; 830 struct mbuf *top, **mp, *m; 831 pktqueue_t *pktq; 832 struct sockaddr dst; 833 int error = 0, s, tlen, mlen; 834 uint32_t family; 835 836 s = splnet(); 837 tp = tun_find_unit(dev); 838 839 /* interface was "destroyed" already */ 840 if (tp == NULL) { 841 error = ENXIO; 842 goto out_nolock; 843 } 844 845 /* Unlock until we've got the data */ 846 mutex_exit(&tp->tun_lock); 847 splx(s); 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 char discard; 862 int n = dst.sa_len - sizeof(dst); 863 while (n--) 864 if ((error = uiomove(&discard, 1, uio)) != 0) { 865 goto out0; 866 } 867 } 868 } else if (tp->tun_flags & TUN_IFHEAD) { 869 if (uio->uio_resid < sizeof(family)){ 870 error = EIO; 871 goto out0; 872 } 873 error = uiomove((void *)&family, sizeof(family), uio); 874 dst.sa_family = ntohl(family); 875 } else { 876 #ifdef INET 877 dst.sa_family = AF_INET; 878 #endif 879 } 880 881 if (uio->uio_resid > TUNMTU) { 882 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 883 (unsigned long)uio->uio_resid); 884 error = EIO; 885 goto out0; 886 } 887 888 switch (dst.sa_family) { 889 #ifdef INET 890 case AF_INET: 891 pktq = ip_pktq; 892 break; 893 #endif 894 #ifdef INET6 895 case AF_INET6: 896 pktq = ip6_pktq; 897 break; 898 #endif 899 default: 900 error = EAFNOSUPPORT; 901 goto out0; 902 } 903 904 tlen = uio->uio_resid; 905 906 /* get a header mbuf */ 907 MGETHDR(m, M_DONTWAIT, MT_DATA); 908 if (m == NULL) { 909 error = ENOBUFS; 910 goto out0; 911 } 912 mlen = MHLEN; 913 914 top = NULL; 915 mp = ⊤ 916 while (error == 0 && uio->uio_resid > 0) { 917 m->m_len = min(mlen, uio->uio_resid); 918 error = uiomove(mtod(m, void *), m->m_len, uio); 919 *mp = m; 920 mp = &m->m_next; 921 if (error == 0 && uio->uio_resid > 0) { 922 MGET(m, M_DONTWAIT, MT_DATA); 923 if (m == NULL) { 924 error = ENOBUFS; 925 break; 926 } 927 mlen = MLEN; 928 } 929 } 930 if (error) { 931 if (top != NULL) 932 m_freem (top); 933 ifp->if_ierrors++; 934 goto out0; 935 } 936 937 top->m_pkthdr.len = tlen; 938 top->m_pkthdr.rcvif = ifp; 939 940 bpf_mtap_af(ifp, dst.sa_family, top); 941 942 s = splnet(); 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 out_nolock; 955 } 956 ifp->if_ipackets++; 957 ifp->if_ibytes += tlen; 958 out: 959 mutex_exit(&tp->tun_lock); 960 out_nolock: 961 splx(s); 962 out0: 963 return (error); 964 } 965 966 #ifdef ALTQ 967 /* 968 * Start packet transmission on the interface. 969 * when the interface queue is rate-limited by ALTQ or TBR, 970 * if_start is needed to drain packets from the queue in order 971 * to notify readers when outgoing packets become ready. 972 * 973 * Should be called at splnet. 974 */ 975 static void 976 tunstart(struct ifnet *ifp) 977 { 978 struct tun_softc *tp = ifp->if_softc; 979 980 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 981 return; 982 983 mutex_enter(&tp->tun_lock); 984 if (!IF_IS_EMPTY(&ifp->if_snd)) { 985 if (tp->tun_flags & TUN_RWAIT) { 986 tp->tun_flags &= ~TUN_RWAIT; 987 wakeup((void *)tp); 988 } 989 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 990 softint_schedule(tp->tun_osih); 991 992 selnotify(&tp->tun_rsel, 0, 0); 993 } 994 mutex_exit(&tp->tun_lock); 995 } 996 #endif /* ALTQ */ 997 /* 998 * tunpoll - the poll interface, this is only useful on reads 999 * really. The write detect always returns true, write never blocks 1000 * anyway, it either accepts the packet or drops it. 1001 */ 1002 int 1003 tunpoll(dev_t dev, int events, struct lwp *l) 1004 { 1005 struct tun_softc *tp; 1006 struct ifnet *ifp; 1007 int s, revents = 0; 1008 1009 s = splnet(); 1010 tp = tun_find_unit(dev); 1011 1012 /* interface was "destroyed" already */ 1013 if (tp == NULL) 1014 goto out_nolock; 1015 1016 ifp = &tp->tun_if; 1017 1018 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1019 1020 if (events & (POLLIN | POLLRDNORM)) { 1021 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1022 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1023 ifp->if_snd.ifq_len); 1024 revents |= events & (POLLIN | POLLRDNORM); 1025 } else { 1026 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1027 selrecord(l, &tp->tun_rsel); 1028 } 1029 } 1030 1031 if (events & (POLLOUT | POLLWRNORM)) 1032 revents |= events & (POLLOUT | POLLWRNORM); 1033 1034 mutex_exit(&tp->tun_lock); 1035 out_nolock: 1036 splx(s); 1037 return (revents); 1038 } 1039 1040 static void 1041 filt_tunrdetach(struct knote *kn) 1042 { 1043 struct tun_softc *tp = kn->kn_hook; 1044 int s; 1045 1046 s = splnet(); 1047 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1048 splx(s); 1049 } 1050 1051 static int 1052 filt_tunread(struct knote *kn, long hint) 1053 { 1054 struct tun_softc *tp = kn->kn_hook; 1055 struct ifnet *ifp = &tp->tun_if; 1056 struct mbuf *m; 1057 int s; 1058 1059 s = splnet(); 1060 IF_POLL(&ifp->if_snd, m); 1061 if (m == NULL) { 1062 splx(s); 1063 return (0); 1064 } 1065 1066 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1067 kn->kn_data += m->m_len; 1068 1069 splx(s); 1070 return (1); 1071 } 1072 1073 static const struct filterops tunread_filtops = 1074 { 1, NULL, filt_tunrdetach, filt_tunread }; 1075 1076 static const struct filterops tun_seltrue_filtops = 1077 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1078 1079 int 1080 tunkqfilter(dev_t dev, struct knote *kn) 1081 { 1082 struct tun_softc *tp; 1083 struct klist *klist; 1084 int rv = 0, s; 1085 1086 s = splnet(); 1087 tp = tun_find_unit(dev); 1088 if (tp == NULL) 1089 goto out_nolock; 1090 1091 switch (kn->kn_filter) { 1092 case EVFILT_READ: 1093 klist = &tp->tun_rsel.sel_klist; 1094 kn->kn_fop = &tunread_filtops; 1095 break; 1096 1097 case EVFILT_WRITE: 1098 klist = &tp->tun_rsel.sel_klist; 1099 kn->kn_fop = &tun_seltrue_filtops; 1100 break; 1101 1102 default: 1103 rv = EINVAL; 1104 goto out; 1105 } 1106 1107 kn->kn_hook = tp; 1108 1109 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1110 1111 out: 1112 mutex_exit(&tp->tun_lock); 1113 out_nolock: 1114 splx(s); 1115 return (rv); 1116 } 1117