1 /* $NetBSD: if_tun.c,v 1.113 2010/04/05 07:22:24 joerg 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 1.113 2010/04/05 07:22:24 joerg Exp $"); 19 20 #include "opt_inet.h" 21 22 #include <sys/param.h> 23 #include <sys/proc.h> 24 #include <sys/systm.h> 25 #include <sys/mbuf.h> 26 #include <sys/buf.h> 27 #include <sys/protosw.h> 28 #include <sys/socket.h> 29 #include <sys/ioctl.h> 30 #include <sys/errno.h> 31 #include <sys/syslog.h> 32 #include <sys/select.h> 33 #include <sys/poll.h> 34 #include <sys/file.h> 35 #include <sys/signalvar.h> 36 #include <sys/conf.h> 37 #include <sys/kauth.h> 38 #include <sys/simplelock.h> 39 #include <sys/cpu.h> 40 41 #include <net/if.h> 42 #include <net/if_types.h> 43 #include <net/netisr.h> 44 #include <net/route.h> 45 46 47 #ifdef INET 48 #include <netinet/in.h> 49 #include <netinet/in_systm.h> 50 #include <netinet/in_var.h> 51 #include <netinet/ip.h> 52 #include <netinet/if_inarp.h> 53 #endif 54 55 56 #include <sys/time.h> 57 #include <net/bpf.h> 58 59 #include <net/if_tun.h> 60 61 #define TUNDEBUG if (tundebug) printf 62 int tundebug = 0; 63 64 extern int ifqmaxlen; 65 void tunattach(int); 66 67 static LIST_HEAD(, tun_softc) tun_softc_list; 68 static LIST_HEAD(, tun_softc) tunz_softc_list; 69 static struct simplelock tun_softc_lock; 70 71 static int tun_ioctl(struct ifnet *, u_long, void *); 72 static int tun_output(struct ifnet *, struct mbuf *, 73 const struct sockaddr *, struct rtentry *rt); 74 static int tun_clone_create(struct if_clone *, int); 75 static int tun_clone_destroy(struct ifnet *); 76 77 static struct if_clone tun_cloner = 78 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 79 80 static void tunattach0(struct tun_softc *); 81 static void tuninit(struct tun_softc *); 82 static void tun_i_softintr(void *); 83 static void tun_o_softintr(void *); 84 #ifdef ALTQ 85 static void tunstart(struct ifnet *); 86 #endif 87 static struct tun_softc *tun_find_unit(dev_t); 88 static struct tun_softc *tun_find_zunit(int); 89 90 static dev_type_open(tunopen); 91 static dev_type_close(tunclose); 92 static dev_type_read(tunread); 93 static dev_type_write(tunwrite); 94 static dev_type_ioctl(tunioctl); 95 static dev_type_poll(tunpoll); 96 static dev_type_kqfilter(tunkqfilter); 97 98 const struct cdevsw tun_cdevsw = { 99 tunopen, tunclose, tunread, tunwrite, tunioctl, 100 nostop, notty, tunpoll, nommap, tunkqfilter, D_OTHER, 101 }; 102 103 void 104 tunattach(int unused) 105 { 106 107 simple_lock_init(&tun_softc_lock); 108 LIST_INIT(&tun_softc_list); 109 LIST_INIT(&tunz_softc_list); 110 if_clone_attach(&tun_cloner); 111 } 112 113 /* 114 * Find driver instance from dev_t. 115 * Call at splnet(). 116 * Returns with tp locked (if found). 117 */ 118 static struct tun_softc * 119 tun_find_unit(dev_t dev) 120 { 121 struct tun_softc *tp; 122 int unit = minor(dev); 123 124 simple_lock(&tun_softc_lock); 125 LIST_FOREACH(tp, &tun_softc_list, tun_list) 126 if (unit == tp->tun_unit) 127 break; 128 if (tp) 129 simple_lock(&tp->tun_lock); 130 simple_unlock(&tun_softc_lock); 131 132 return (tp); 133 } 134 135 /* 136 * Find zombie driver instance by unit number. 137 * Call at splnet(). 138 * Remove tp from list and return it unlocked (if found). 139 */ 140 static struct tun_softc * 141 tun_find_zunit(int unit) 142 { 143 struct tun_softc *tp; 144 145 simple_lock(&tun_softc_lock); 146 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 147 if (unit == tp->tun_unit) 148 break; 149 if (tp) 150 LIST_REMOVE(tp, tun_list); 151 simple_unlock(&tun_softc_lock); 152 #ifdef DIAGNOSTIC 153 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 154 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 155 #endif 156 157 return (tp); 158 } 159 160 static int 161 tun_clone_create(struct if_clone *ifc, int unit) 162 { 163 struct tun_softc *tp; 164 165 if ((tp = tun_find_zunit(unit)) == NULL) { 166 /* Allocate a new instance */ 167 tp = malloc(sizeof(*tp), M_DEVBUF, M_WAITOK|M_ZERO); 168 169 tp->tun_unit = unit; 170 simple_lock_init(&tp->tun_lock); 171 selinit(&tp->tun_rsel); 172 selinit(&tp->tun_wsel); 173 } else { 174 /* Revive tunnel instance; clear ifp part */ 175 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 176 } 177 178 if_initname(&tp->tun_if, ifc->ifc_name, unit); 179 tunattach0(tp); 180 tp->tun_flags |= TUN_INITED; 181 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 182 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 183 184 simple_lock(&tun_softc_lock); 185 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 186 simple_unlock(&tun_softc_lock); 187 188 return (0); 189 } 190 191 static void 192 tunattach0(struct tun_softc *tp) 193 { 194 struct ifnet *ifp; 195 196 ifp = &tp->tun_if; 197 ifp->if_softc = tp; 198 ifp->if_mtu = TUNMTU; 199 ifp->if_ioctl = tun_ioctl; 200 ifp->if_output = tun_output; 201 #ifdef ALTQ 202 ifp->if_start = tunstart; 203 #endif 204 ifp->if_flags = IFF_POINTOPOINT; 205 ifp->if_type = IFT_TUNNEL; 206 ifp->if_snd.ifq_maxlen = ifqmaxlen; 207 ifp->if_collisions = 0; 208 ifp->if_ierrors = 0; 209 ifp->if_oerrors = 0; 210 ifp->if_ipackets = 0; 211 ifp->if_opackets = 0; 212 ifp->if_ibytes = 0; 213 ifp->if_obytes = 0; 214 ifp->if_dlt = DLT_NULL; 215 IFQ_SET_READY(&ifp->if_snd); 216 if_attach(ifp); 217 if_alloc_sadl(ifp); 218 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 219 } 220 221 static int 222 tun_clone_destroy(struct ifnet *ifp) 223 { 224 struct tun_softc *tp = (void *)ifp; 225 int s, zombie = 0; 226 227 s = splnet(); 228 simple_lock(&tun_softc_lock); 229 simple_lock(&tp->tun_lock); 230 LIST_REMOVE(tp, tun_list); 231 if (tp->tun_flags & TUN_OPEN) { 232 /* Hang on to storage until last close */ 233 zombie = 1; 234 tp->tun_flags &= ~TUN_INITED; 235 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 236 } 237 simple_unlock(&tun_softc_lock); 238 239 IF_PURGE(&ifp->if_snd); 240 ifp->if_flags &= ~IFF_RUNNING; 241 242 if (tp->tun_flags & TUN_RWAIT) { 243 tp->tun_flags &= ~TUN_RWAIT; 244 wakeup((void *)tp); 245 } 246 selnotify(&tp->tun_rsel, 0, 0); 247 248 simple_unlock(&tp->tun_lock); 249 splx(s); 250 251 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 252 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 253 254 bpf_detach(ifp); 255 if_detach(ifp); 256 257 if (!zombie) { 258 seldestroy(&tp->tun_rsel); 259 seldestroy(&tp->tun_wsel); 260 softint_disestablish(tp->tun_osih); 261 softint_disestablish(tp->tun_isih); 262 free(tp, M_DEVBUF); 263 } 264 265 return (0); 266 } 267 268 /* 269 * tunnel open - must be superuser & the device must be 270 * configured in 271 */ 272 static int 273 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 274 { 275 struct ifnet *ifp; 276 struct tun_softc *tp; 277 int s, error; 278 279 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 280 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 281 if (error) 282 return (error); 283 284 s = splnet(); 285 tp = tun_find_unit(dev); 286 287 if (tp == NULL) { 288 (void)tun_clone_create(&tun_cloner, minor(dev)); 289 tp = tun_find_unit(dev); 290 if (tp == NULL) { 291 error = ENXIO; 292 goto out_nolock; 293 } 294 } 295 296 if (tp->tun_flags & TUN_OPEN) { 297 error = EBUSY; 298 goto out; 299 } 300 301 ifp = &tp->tun_if; 302 tp->tun_flags |= TUN_OPEN; 303 TUNDEBUG("%s: open\n", ifp->if_xname); 304 out: 305 simple_unlock(&tp->tun_lock); 306 out_nolock: 307 splx(s); 308 return (error); 309 } 310 311 /* 312 * tunclose - close the device - mark i/f down & delete 313 * routing info 314 */ 315 int 316 tunclose(dev_t dev, int flag, int mode, 317 struct lwp *l) 318 { 319 int s; 320 struct tun_softc *tp; 321 struct ifnet *ifp; 322 323 s = splnet(); 324 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 325 /* interface was "destroyed" before the close */ 326 seldestroy(&tp->tun_rsel); 327 seldestroy(&tp->tun_wsel); 328 softint_disestablish(tp->tun_osih); 329 softint_disestablish(tp->tun_isih); 330 free(tp, M_DEVBUF); 331 goto out_nolock; 332 } 333 334 if ((tp = tun_find_unit(dev)) == NULL) 335 goto out_nolock; 336 337 ifp = &tp->tun_if; 338 339 tp->tun_flags &= ~TUN_OPEN; 340 341 /* 342 * junk all pending output 343 */ 344 IFQ_PURGE(&ifp->if_snd); 345 346 if (ifp->if_flags & IFF_UP) { 347 if_down(ifp); 348 if (ifp->if_flags & IFF_RUNNING) { 349 /* find internet addresses and delete routes */ 350 struct ifaddr *ifa; 351 IFADDR_FOREACH(ifa, ifp) { 352 #if defined(INET) || defined(INET6) 353 if (ifa->ifa_addr->sa_family == AF_INET || 354 ifa->ifa_addr->sa_family == AF_INET6) { 355 rtinit(ifa, (int)RTM_DELETE, 356 tp->tun_flags & TUN_DSTADDR 357 ? RTF_HOST 358 : 0); 359 } 360 #endif 361 } 362 } 363 } 364 tp->tun_pgid = 0; 365 selnotify(&tp->tun_rsel, 0, 0); 366 367 TUNDEBUG ("%s: closed\n", ifp->if_xname); 368 simple_unlock(&tp->tun_lock); 369 out_nolock: 370 splx(s); 371 return (0); 372 } 373 374 /* 375 * Call at splnet(). 376 */ 377 static void 378 tuninit(struct tun_softc *tp) 379 { 380 struct ifnet *ifp = &tp->tun_if; 381 struct ifaddr *ifa; 382 383 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 384 385 simple_lock(&tp->tun_lock); 386 ifp->if_flags |= IFF_UP | IFF_RUNNING; 387 388 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 389 IFADDR_FOREACH(ifa, ifp) { 390 #ifdef INET 391 if (ifa->ifa_addr->sa_family == AF_INET) { 392 struct sockaddr_in *sin; 393 394 sin = satosin(ifa->ifa_addr); 395 if (sin && sin->sin_addr.s_addr) 396 tp->tun_flags |= TUN_IASET; 397 398 if (ifp->if_flags & IFF_POINTOPOINT) { 399 sin = satosin(ifa->ifa_dstaddr); 400 if (sin && sin->sin_addr.s_addr) 401 tp->tun_flags |= TUN_DSTADDR; 402 } 403 } 404 #endif 405 #ifdef INET6 406 if (ifa->ifa_addr->sa_family == AF_INET6) { 407 struct sockaddr_in6 *sin; 408 409 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 410 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 411 tp->tun_flags |= TUN_IASET; 412 413 if (ifp->if_flags & IFF_POINTOPOINT) { 414 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 415 if (sin && 416 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 417 tp->tun_flags |= TUN_DSTADDR; 418 } else 419 tp->tun_flags &= ~TUN_DSTADDR; 420 } 421 #endif /* INET6 */ 422 } 423 424 simple_unlock(&tp->tun_lock); 425 return; 426 } 427 428 /* 429 * Process an ioctl request. 430 */ 431 static int 432 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 433 { 434 int error = 0, s; 435 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 436 struct ifreq *ifr = data; 437 438 s = splnet(); 439 440 switch (cmd) { 441 case SIOCINITIFADDR: 442 tuninit(tp); 443 TUNDEBUG("%s: address set\n", ifp->if_xname); 444 break; 445 case SIOCSIFDSTADDR: 446 tuninit(tp); 447 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 448 break; 449 case SIOCSIFBRDADDR: 450 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 451 break; 452 case SIOCSIFMTU: 453 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 454 error = EINVAL; 455 break; 456 } 457 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 458 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 459 error = 0; 460 break; 461 case SIOCADDMULTI: 462 case SIOCDELMULTI: 463 if (ifr == NULL) { 464 error = EAFNOSUPPORT; /* XXX */ 465 break; 466 } 467 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 468 #ifdef INET 469 case AF_INET: 470 break; 471 #endif 472 #ifdef INET6 473 case AF_INET6: 474 break; 475 #endif 476 default: 477 error = EAFNOSUPPORT; 478 break; 479 } 480 break; 481 default: 482 error = ifioctl_common(ifp, cmd, data); 483 } 484 485 splx(s); 486 return (error); 487 } 488 489 /* 490 * tun_output - queue packets from higher level ready to put out. 491 */ 492 static int 493 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 494 struct rtentry *rt) 495 { 496 struct tun_softc *tp = ifp->if_softc; 497 int s; 498 int error; 499 #if defined(INET) || defined(INET6) 500 int mlen; 501 uint32_t *af; 502 #endif 503 ALTQ_DECL(struct altq_pktattr pktattr;) 504 505 s = splnet(); 506 simple_lock(&tp->tun_lock); 507 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 508 509 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 510 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 511 tp->tun_flags); 512 m_freem (m0); 513 error = EHOSTDOWN; 514 goto out; 515 } 516 517 /* 518 * if the queueing discipline needs packet classification, 519 * do it before prepending link headers. 520 */ 521 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 522 523 bpf_mtap_af(ifp, dst->sa_family, m0); 524 525 switch(dst->sa_family) { 526 #ifdef INET6 527 case AF_INET6: 528 #endif 529 #ifdef INET 530 case AF_INET: 531 #endif 532 #if defined(INET) || defined(INET6) 533 if (tp->tun_flags & TUN_PREPADDR) { 534 /* Simple link-layer header */ 535 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 536 if (m0 == NULL) { 537 IF_DROP(&ifp->if_snd); 538 error = ENOBUFS; 539 goto out; 540 } 541 bcopy(dst, mtod(m0, char *), dst->sa_len); 542 } 543 544 if (tp->tun_flags & TUN_IFHEAD) { 545 /* Prepend the address family */ 546 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 547 if (m0 == NULL) { 548 IF_DROP(&ifp->if_snd); 549 error = ENOBUFS; 550 goto out; 551 } 552 af = mtod(m0,uint32_t *); 553 *af = htonl(dst->sa_family); 554 } else { 555 #ifdef INET 556 if (dst->sa_family != AF_INET) 557 #endif 558 { 559 m_freem(m0); 560 error = EAFNOSUPPORT; 561 goto out; 562 } 563 } 564 /* FALLTHROUGH */ 565 case AF_UNSPEC: 566 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 567 if (error) { 568 ifp->if_collisions++; 569 error = EAFNOSUPPORT; 570 goto out; 571 } 572 mlen = m0->m_pkthdr.len; 573 ifp->if_opackets++; 574 ifp->if_obytes += mlen; 575 break; 576 #endif 577 default: 578 m_freem(m0); 579 error = EAFNOSUPPORT; 580 goto out; 581 } 582 583 if (tp->tun_flags & TUN_RWAIT) { 584 tp->tun_flags &= ~TUN_RWAIT; 585 wakeup((void *)tp); 586 } 587 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 588 softint_schedule(tp->tun_isih); 589 590 selnotify(&tp->tun_rsel, 0, 0); 591 out: 592 simple_unlock(&tp->tun_lock); 593 splx(s); 594 return (0); 595 } 596 597 static void 598 tun_i_softintr(void *cookie) 599 { 600 struct tun_softc *tp = cookie; 601 602 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 603 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 604 NULL); 605 } 606 607 static void 608 tun_o_softintr(void *cookie) 609 { 610 struct tun_softc *tp = cookie; 611 612 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 613 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 614 NULL); 615 } 616 617 /* 618 * the cdevsw interface is now pretty minimal. 619 */ 620 int 621 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 622 { 623 struct tun_softc *tp; 624 int s, error = 0; 625 626 s = splnet(); 627 tp = tun_find_unit(dev); 628 629 /* interface was "destroyed" already */ 630 if (tp == NULL) { 631 error = ENXIO; 632 goto out_nolock; 633 } 634 635 switch (cmd) { 636 case TUNSDEBUG: 637 tundebug = *(int *)data; 638 break; 639 640 case TUNGDEBUG: 641 *(int *)data = tundebug; 642 break; 643 644 case TUNSIFMODE: 645 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 646 case IFF_POINTOPOINT: 647 case IFF_BROADCAST: 648 if (tp->tun_if.if_flags & IFF_UP) { 649 error = EBUSY; 650 goto out; 651 } 652 tp->tun_if.if_flags &= 653 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 654 tp->tun_if.if_flags |= *(int *)data; 655 break; 656 default: 657 error = EINVAL; 658 goto out; 659 } 660 break; 661 662 case TUNSLMODE: 663 if (*(int *)data) { 664 tp->tun_flags |= TUN_PREPADDR; 665 tp->tun_flags &= ~TUN_IFHEAD; 666 } else 667 tp->tun_flags &= ~TUN_PREPADDR; 668 break; 669 670 case TUNSIFHEAD: 671 if (*(int *)data) { 672 tp->tun_flags |= TUN_IFHEAD; 673 tp->tun_flags &= ~TUN_PREPADDR; 674 } else 675 tp->tun_flags &= ~TUN_IFHEAD; 676 break; 677 678 case TUNGIFHEAD: 679 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 680 break; 681 682 case FIONBIO: 683 if (*(int *)data) 684 tp->tun_flags |= TUN_NBIO; 685 else 686 tp->tun_flags &= ~TUN_NBIO; 687 break; 688 689 case FIOASYNC: 690 if (*(int *)data) 691 tp->tun_flags |= TUN_ASYNC; 692 else 693 tp->tun_flags &= ~TUN_ASYNC; 694 break; 695 696 case FIONREAD: 697 if (tp->tun_if.if_snd.ifq_head) 698 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 699 else 700 *(int *)data = 0; 701 break; 702 703 case TIOCSPGRP: 704 case FIOSETOWN: 705 error = fsetown(&tp->tun_pgid, cmd, data); 706 break; 707 708 case TIOCGPGRP: 709 case FIOGETOWN: 710 error = fgetown(tp->tun_pgid, cmd, data); 711 break; 712 713 default: 714 error = ENOTTY; 715 } 716 717 out: 718 simple_unlock(&tp->tun_lock); 719 out_nolock: 720 splx(s); 721 return (error); 722 } 723 724 /* 725 * The cdevsw read interface - reads a packet at a time, or at 726 * least as much of a packet as can be read. 727 */ 728 int 729 tunread(dev_t dev, struct uio *uio, int ioflag) 730 { 731 struct tun_softc *tp; 732 struct ifnet *ifp; 733 struct mbuf *m, *m0; 734 int error = 0, len, s, index; 735 736 s = splnet(); 737 tp = tun_find_unit(dev); 738 739 /* interface was "destroyed" already */ 740 if (tp == NULL) { 741 error = ENXIO; 742 goto out_nolock; 743 } 744 745 index = tp->tun_if.if_index; 746 ifp = &tp->tun_if; 747 748 TUNDEBUG ("%s: read\n", ifp->if_xname); 749 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 750 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 751 error = EHOSTDOWN; 752 goto out; 753 } 754 755 tp->tun_flags &= ~TUN_RWAIT; 756 757 do { 758 IFQ_DEQUEUE(&ifp->if_snd, m0); 759 if (m0 == 0) { 760 if (tp->tun_flags & TUN_NBIO) { 761 error = EWOULDBLOCK; 762 goto out; 763 } 764 tp->tun_flags |= TUN_RWAIT; 765 if (ltsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 766 "tunread", 0, &tp->tun_lock) != 0) { 767 error = EINTR; 768 goto out_nolock; 769 } else { 770 /* 771 * Maybe the interface was destroyed while 772 * we were sleeping, so let's ensure that 773 * we're looking at the same (valid) tun 774 * interface before looping. 775 */ 776 tp = tun_find_unit(dev); 777 if (tp == NULL) { 778 error = ENXIO; 779 goto out_nolock; 780 } 781 if (tp->tun_if.if_index != index) { 782 error = ENXIO; 783 goto out; 784 } 785 } 786 } 787 } while (m0 == 0); 788 789 simple_unlock(&tp->tun_lock); 790 splx(s); 791 792 /* Copy the mbuf chain */ 793 while (m0 && uio->uio_resid > 0 && error == 0) { 794 len = min(uio->uio_resid, m0->m_len); 795 if (len != 0) 796 error = uiomove(mtod(m0, void *), len, uio); 797 MFREE(m0, m); 798 m0 = m; 799 } 800 801 if (m0) { 802 TUNDEBUG("Dropping mbuf\n"); 803 m_freem(m0); 804 } 805 if (error) 806 ifp->if_ierrors++; 807 808 return (error); 809 810 out: 811 simple_unlock(&tp->tun_lock); 812 out_nolock: 813 splx(s); 814 return (error); 815 } 816 817 /* 818 * the cdevsw write interface - an atomic write is a packet - or else! 819 */ 820 int 821 tunwrite(dev_t dev, struct uio *uio, int ioflag) 822 { 823 struct tun_softc *tp; 824 struct ifnet *ifp; 825 struct mbuf *top, **mp, *m; 826 struct ifqueue *ifq; 827 struct sockaddr dst; 828 int isr, error = 0, s, tlen, mlen; 829 uint32_t family; 830 831 s = splnet(); 832 tp = tun_find_unit(dev); 833 834 /* interface was "destroyed" already */ 835 if (tp == NULL) { 836 error = ENXIO; 837 goto out_nolock; 838 } 839 840 /* Unlock until we've got the data */ 841 simple_unlock(&tp->tun_lock); 842 splx(s); 843 844 ifp = &tp->tun_if; 845 846 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 847 848 if (tp->tun_flags & TUN_PREPADDR) { 849 if (uio->uio_resid < sizeof(dst)) { 850 error = EIO; 851 goto out0; 852 } 853 error = uiomove((void *)&dst, sizeof(dst), uio); 854 if (dst.sa_len > sizeof(dst)) { 855 /* Duh.. */ 856 char discard; 857 int n = dst.sa_len - sizeof(dst); 858 while (n--) 859 if ((error = uiomove(&discard, 1, uio)) != 0) { 860 goto out0; 861 } 862 } 863 } else if (tp->tun_flags & TUN_IFHEAD) { 864 if (uio->uio_resid < sizeof(family)){ 865 error = EIO; 866 goto out0; 867 } 868 error = uiomove((void *)&family, sizeof(family), uio); 869 dst.sa_family = ntohl(family); 870 } else { 871 #ifdef INET 872 dst.sa_family = AF_INET; 873 #endif 874 } 875 876 if (uio->uio_resid > TUNMTU) { 877 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 878 (unsigned long)uio->uio_resid); 879 error = EIO; 880 goto out0; 881 } 882 883 switch (dst.sa_family) { 884 #ifdef INET 885 case AF_INET: 886 ifq = &ipintrq; 887 isr = NETISR_IP; 888 break; 889 #endif 890 #ifdef INET6 891 case AF_INET6: 892 ifq = &ip6intrq; 893 isr = NETISR_IPV6; 894 break; 895 #endif 896 default: 897 error = EAFNOSUPPORT; 898 goto out0; 899 } 900 901 tlen = uio->uio_resid; 902 903 /* get a header mbuf */ 904 MGETHDR(m, M_DONTWAIT, MT_DATA); 905 if (m == NULL) { 906 error = ENOBUFS; 907 goto out0; 908 } 909 mlen = MHLEN; 910 911 top = NULL; 912 mp = ⊤ 913 while (error == 0 && uio->uio_resid > 0) { 914 m->m_len = min(mlen, uio->uio_resid); 915 error = uiomove(mtod(m, void *), m->m_len, uio); 916 *mp = m; 917 mp = &m->m_next; 918 if (error == 0 && uio->uio_resid > 0) { 919 MGET(m, M_DONTWAIT, MT_DATA); 920 if (m == NULL) { 921 error = ENOBUFS; 922 break; 923 } 924 mlen = MLEN; 925 } 926 } 927 if (error) { 928 if (top != NULL) 929 m_freem (top); 930 ifp->if_ierrors++; 931 goto out0; 932 } 933 934 top->m_pkthdr.len = tlen; 935 top->m_pkthdr.rcvif = ifp; 936 937 bpf_mtap_af(ifp, dst.sa_family, top); 938 939 s = splnet(); 940 simple_lock(&tp->tun_lock); 941 if ((tp->tun_flags & TUN_INITED) == 0) { 942 /* Interface was destroyed */ 943 error = ENXIO; 944 goto out; 945 } 946 if (IF_QFULL(ifq)) { 947 IF_DROP(ifq); 948 ifp->if_collisions++; 949 m_freem(top); 950 error = ENOBUFS; 951 goto out; 952 } 953 954 IF_ENQUEUE(ifq, top); 955 ifp->if_ipackets++; 956 ifp->if_ibytes += tlen; 957 schednetisr(isr); 958 out: 959 simple_unlock(&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 simple_lock(&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 simple_unlock(&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 simple_unlock(&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 simple_unlock(&tp->tun_lock); 1113 out_nolock: 1114 splx(s); 1115 return (rv); 1116 } 1117