if_tun.c revision 1.118
1 /* $NetBSD: if_tun.c,v 1.118 2014/06/05 23:48:16 rmind 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 #include <sys/cdefs.h> 18 __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.118 2014/06/05 23:48:16 rmind 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/mutex.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 kmutex_t 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 .d_open = tunopen, 100 .d_close = tunclose, 101 .d_read = tunread, 102 .d_write = tunwrite, 103 .d_ioctl = tunioctl, 104 .d_stop = nostop, 105 .d_tty = notty, 106 .d_poll = tunpoll, 107 .d_mmap = nommap, 108 .d_kqfilter = tunkqfilter, 109 .d_flag = D_OTHER 110 }; 111 112 void 113 tunattach(int unused) 114 { 115 116 mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NET); 117 LIST_INIT(&tun_softc_list); 118 LIST_INIT(&tunz_softc_list); 119 if_clone_attach(&tun_cloner); 120 } 121 122 /* 123 * Find driver instance from dev_t. 124 * Returns with tp locked (if found). 125 */ 126 static struct tun_softc * 127 tun_find_unit(dev_t dev) 128 { 129 struct tun_softc *tp; 130 int unit = minor(dev); 131 132 mutex_enter(&tun_softc_lock); 133 LIST_FOREACH(tp, &tun_softc_list, tun_list) 134 if (unit == tp->tun_unit) 135 break; 136 if (tp) 137 mutex_enter(&tp->tun_lock); 138 mutex_exit(&tun_softc_lock); 139 140 return (tp); 141 } 142 143 /* 144 * Find zombie driver instance by unit number. 145 * Remove tp from list and return it unlocked (if found). 146 */ 147 static struct tun_softc * 148 tun_find_zunit(int unit) 149 { 150 struct tun_softc *tp; 151 152 mutex_enter(&tun_softc_lock); 153 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 154 if (unit == tp->tun_unit) 155 break; 156 if (tp) 157 LIST_REMOVE(tp, tun_list); 158 mutex_exit(&tun_softc_lock); 159 #ifdef DIAGNOSTIC 160 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 161 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 162 #endif 163 164 return (tp); 165 } 166 167 static int 168 tun_clone_create(struct if_clone *ifc, int unit) 169 { 170 struct tun_softc *tp; 171 172 if ((tp = tun_find_zunit(unit)) == NULL) { 173 /* Allocate a new instance */ 174 tp = malloc(sizeof(*tp), M_DEVBUF, M_WAITOK|M_ZERO); 175 176 tp->tun_unit = unit; 177 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 178 selinit(&tp->tun_rsel); 179 selinit(&tp->tun_wsel); 180 } else { 181 /* Revive tunnel instance; clear ifp part */ 182 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 183 } 184 185 if_initname(&tp->tun_if, ifc->ifc_name, unit); 186 tunattach0(tp); 187 tp->tun_flags |= TUN_INITED; 188 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 189 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 190 191 mutex_enter(&tun_softc_lock); 192 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 193 mutex_exit(&tun_softc_lock); 194 195 return (0); 196 } 197 198 static void 199 tunattach0(struct tun_softc *tp) 200 { 201 struct ifnet *ifp; 202 203 ifp = &tp->tun_if; 204 ifp->if_softc = tp; 205 ifp->if_mtu = TUNMTU; 206 ifp->if_ioctl = tun_ioctl; 207 ifp->if_output = tun_output; 208 #ifdef ALTQ 209 ifp->if_start = tunstart; 210 #endif 211 ifp->if_flags = IFF_POINTOPOINT; 212 ifp->if_type = IFT_TUNNEL; 213 ifp->if_snd.ifq_maxlen = ifqmaxlen; 214 ifp->if_collisions = 0; 215 ifp->if_ierrors = 0; 216 ifp->if_oerrors = 0; 217 ifp->if_ipackets = 0; 218 ifp->if_opackets = 0; 219 ifp->if_ibytes = 0; 220 ifp->if_obytes = 0; 221 ifp->if_dlt = DLT_NULL; 222 IFQ_SET_READY(&ifp->if_snd); 223 if_attach(ifp); 224 if_alloc_sadl(ifp); 225 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 226 } 227 228 static int 229 tun_clone_destroy(struct ifnet *ifp) 230 { 231 struct tun_softc *tp = (void *)ifp; 232 int zombie = 0; 233 234 IF_PURGE(&ifp->if_snd); 235 ifp->if_flags &= ~IFF_RUNNING; 236 237 mutex_enter(&tun_softc_lock); 238 mutex_enter(&tp->tun_lock); 239 LIST_REMOVE(tp, tun_list); 240 if (tp->tun_flags & TUN_OPEN) { 241 /* Hang on to storage until last close */ 242 zombie = 1; 243 tp->tun_flags &= ~TUN_INITED; 244 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 245 } 246 mutex_exit(&tun_softc_lock); 247 248 if (tp->tun_flags & TUN_RWAIT) { 249 tp->tun_flags &= ~TUN_RWAIT; 250 wakeup((void *)tp); 251 } 252 selnotify(&tp->tun_rsel, 0, 0); 253 254 mutex_exit(&tp->tun_lock); 255 256 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 257 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 258 259 bpf_detach(ifp); 260 if_detach(ifp); 261 262 if (!zombie) { 263 seldestroy(&tp->tun_rsel); 264 seldestroy(&tp->tun_wsel); 265 softint_disestablish(tp->tun_osih); 266 softint_disestablish(tp->tun_isih); 267 mutex_destroy(&tp->tun_lock); 268 free(tp, M_DEVBUF); 269 } 270 271 return (0); 272 } 273 274 /* 275 * tunnel open - must be superuser & the device must be 276 * configured in 277 */ 278 static int 279 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 280 { 281 struct ifnet *ifp; 282 struct tun_softc *tp; 283 int error; 284 285 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 286 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 287 if (error) 288 return (error); 289 290 tp = tun_find_unit(dev); 291 292 if (tp == NULL) { 293 (void)tun_clone_create(&tun_cloner, minor(dev)); 294 tp = tun_find_unit(dev); 295 if (tp == NULL) { 296 error = ENXIO; 297 goto out_nolock; 298 } 299 } 300 301 if (tp->tun_flags & TUN_OPEN) { 302 error = EBUSY; 303 goto out; 304 } 305 306 ifp = &tp->tun_if; 307 tp->tun_flags |= TUN_OPEN; 308 TUNDEBUG("%s: open\n", ifp->if_xname); 309 out: 310 mutex_exit(&tp->tun_lock); 311 out_nolock: 312 return (error); 313 } 314 315 /* 316 * tunclose - close the device - mark i/f down & delete 317 * routing info 318 */ 319 int 320 tunclose(dev_t dev, int flag, int mode, 321 struct lwp *l) 322 { 323 struct tun_softc *tp; 324 struct ifnet *ifp; 325 326 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 327 /* interface was "destroyed" before the close */ 328 seldestroy(&tp->tun_rsel); 329 seldestroy(&tp->tun_wsel); 330 softint_disestablish(tp->tun_osih); 331 softint_disestablish(tp->tun_isih); 332 mutex_destroy(&tp->tun_lock); 333 free(tp, M_DEVBUF); 334 goto out_nolock; 335 } 336 337 if ((tp = tun_find_unit(dev)) == NULL) 338 goto out_nolock; 339 340 ifp = &tp->tun_if; 341 342 tp->tun_flags &= ~TUN_OPEN; 343 344 tp->tun_pgid = 0; 345 selnotify(&tp->tun_rsel, 0, 0); 346 347 TUNDEBUG ("%s: closed\n", ifp->if_xname); 348 mutex_exit(&tp->tun_lock); 349 350 /* 351 * junk all pending output 352 */ 353 IFQ_PURGE(&ifp->if_snd); 354 355 if (ifp->if_flags & IFF_UP) { 356 if_down(ifp); 357 if (ifp->if_flags & IFF_RUNNING) { 358 /* find internet addresses and delete routes */ 359 struct ifaddr *ifa; 360 IFADDR_FOREACH(ifa, ifp) { 361 #if defined(INET) || defined(INET6) 362 if (ifa->ifa_addr->sa_family == AF_INET || 363 ifa->ifa_addr->sa_family == AF_INET6) { 364 rtinit(ifa, (int)RTM_DELETE, 365 tp->tun_flags & TUN_DSTADDR 366 ? RTF_HOST 367 : 0); 368 } 369 #endif 370 } 371 } 372 } 373 out_nolock: 374 return (0); 375 } 376 377 /* 378 * Call at splnet(). 379 */ 380 static void 381 tuninit(struct tun_softc *tp) 382 { 383 struct ifnet *ifp = &tp->tun_if; 384 struct ifaddr *ifa; 385 386 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 387 388 mutex_enter(&tp->tun_lock); 389 ifp->if_flags |= IFF_UP | IFF_RUNNING; 390 391 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 392 IFADDR_FOREACH(ifa, ifp) { 393 #ifdef INET 394 if (ifa->ifa_addr->sa_family == AF_INET) { 395 struct sockaddr_in *sin; 396 397 sin = satosin(ifa->ifa_addr); 398 if (sin && sin->sin_addr.s_addr) 399 tp->tun_flags |= TUN_IASET; 400 401 if (ifp->if_flags & IFF_POINTOPOINT) { 402 sin = satosin(ifa->ifa_dstaddr); 403 if (sin && sin->sin_addr.s_addr) 404 tp->tun_flags |= TUN_DSTADDR; 405 } 406 } 407 #endif 408 #ifdef INET6 409 if (ifa->ifa_addr->sa_family == AF_INET6) { 410 struct sockaddr_in6 *sin; 411 412 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 413 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 414 tp->tun_flags |= TUN_IASET; 415 416 if (ifp->if_flags & IFF_POINTOPOINT) { 417 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 418 if (sin && 419 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 420 tp->tun_flags |= TUN_DSTADDR; 421 } else 422 tp->tun_flags &= ~TUN_DSTADDR; 423 } 424 #endif /* INET6 */ 425 } 426 mutex_exit(&tp->tun_lock); 427 } 428 429 /* 430 * Process an ioctl request. 431 */ 432 static int 433 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 434 { 435 int error = 0, s; 436 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 437 struct ifreq *ifr = data; 438 439 s = splnet(); 440 441 switch (cmd) { 442 case SIOCINITIFADDR: 443 tuninit(tp); 444 TUNDEBUG("%s: address set\n", ifp->if_xname); 445 break; 446 case SIOCSIFBRDADDR: 447 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 448 break; 449 case SIOCSIFMTU: 450 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 451 error = EINVAL; 452 break; 453 } 454 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 455 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 456 error = 0; 457 break; 458 case SIOCADDMULTI: 459 case SIOCDELMULTI: 460 if (ifr == NULL) { 461 error = EAFNOSUPPORT; /* XXX */ 462 break; 463 } 464 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 465 #ifdef INET 466 case AF_INET: 467 break; 468 #endif 469 #ifdef INET6 470 case AF_INET6: 471 break; 472 #endif 473 default: 474 error = EAFNOSUPPORT; 475 break; 476 } 477 break; 478 default: 479 error = ifioctl_common(ifp, cmd, data); 480 } 481 482 splx(s); 483 return (error); 484 } 485 486 /* 487 * tun_output - queue packets from higher level ready to put out. 488 */ 489 static int 490 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 491 struct rtentry *rt) 492 { 493 struct tun_softc *tp = ifp->if_softc; 494 int s; 495 int error; 496 #if defined(INET) || defined(INET6) 497 int mlen; 498 uint32_t *af; 499 #endif 500 ALTQ_DECL(struct altq_pktattr pktattr;) 501 502 s = splnet(); 503 mutex_enter(&tp->tun_lock); 504 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 505 506 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 507 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 508 tp->tun_flags); 509 error = EHOSTDOWN; 510 goto out; 511 } 512 513 /* 514 * if the queueing discipline needs packet classification, 515 * do it before prepending link headers. 516 */ 517 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 518 519 bpf_mtap_af(ifp, dst->sa_family, m0); 520 521 switch(dst->sa_family) { 522 #ifdef INET6 523 case AF_INET6: 524 #endif 525 #ifdef INET 526 case AF_INET: 527 #endif 528 #if defined(INET) || defined(INET6) 529 if (tp->tun_flags & TUN_PREPADDR) { 530 /* Simple link-layer header */ 531 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 532 if (m0 == NULL) { 533 IF_DROP(&ifp->if_snd); 534 error = ENOBUFS; 535 goto out; 536 } 537 bcopy(dst, mtod(m0, char *), dst->sa_len); 538 } 539 540 if (tp->tun_flags & TUN_IFHEAD) { 541 /* Prepend the address family */ 542 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 543 if (m0 == NULL) { 544 IF_DROP(&ifp->if_snd); 545 error = ENOBUFS; 546 goto out; 547 } 548 af = mtod(m0,uint32_t *); 549 *af = htonl(dst->sa_family); 550 } else { 551 #ifdef INET 552 if (dst->sa_family != AF_INET) 553 #endif 554 { 555 error = EAFNOSUPPORT; 556 goto out; 557 } 558 } 559 /* FALLTHROUGH */ 560 case AF_UNSPEC: 561 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 562 if (error) { 563 ifp->if_collisions++; 564 error = EAFNOSUPPORT; 565 m0 = NULL; 566 goto out; 567 } 568 mlen = m0->m_pkthdr.len; 569 ifp->if_opackets++; 570 ifp->if_obytes += mlen; 571 break; 572 #endif 573 default: 574 error = EAFNOSUPPORT; 575 goto out; 576 } 577 578 if (tp->tun_flags & TUN_RWAIT) { 579 tp->tun_flags &= ~TUN_RWAIT; 580 wakeup((void *)tp); 581 } 582 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 583 softint_schedule(tp->tun_isih); 584 585 selnotify(&tp->tun_rsel, 0, 0); 586 out: 587 mutex_exit(&tp->tun_lock); 588 splx(s); 589 590 if (error && m0) { 591 m_freem(m0); 592 } 593 return 0; 594 } 595 596 static void 597 tun_i_softintr(void *cookie) 598 { 599 struct tun_softc *tp = cookie; 600 601 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 602 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 603 NULL); 604 } 605 606 static void 607 tun_o_softintr(void *cookie) 608 { 609 struct tun_softc *tp = cookie; 610 611 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 612 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 613 NULL); 614 } 615 616 /* 617 * the cdevsw interface is now pretty minimal. 618 */ 619 int 620 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 621 { 622 struct tun_softc *tp; 623 int s, error = 0; 624 625 s = splnet(); 626 tp = tun_find_unit(dev); 627 628 /* interface was "destroyed" already */ 629 if (tp == NULL) { 630 error = ENXIO; 631 goto out_nolock; 632 } 633 634 switch (cmd) { 635 case TUNSDEBUG: 636 tundebug = *(int *)data; 637 break; 638 639 case TUNGDEBUG: 640 *(int *)data = tundebug; 641 break; 642 643 case TUNSIFMODE: 644 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 645 case IFF_POINTOPOINT: 646 case IFF_BROADCAST: 647 if (tp->tun_if.if_flags & IFF_UP) { 648 error = EBUSY; 649 goto out; 650 } 651 tp->tun_if.if_flags &= 652 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 653 tp->tun_if.if_flags |= *(int *)data; 654 break; 655 default: 656 error = EINVAL; 657 goto out; 658 } 659 break; 660 661 case TUNSLMODE: 662 if (*(int *)data) { 663 tp->tun_flags |= TUN_PREPADDR; 664 tp->tun_flags &= ~TUN_IFHEAD; 665 } else 666 tp->tun_flags &= ~TUN_PREPADDR; 667 break; 668 669 case TUNSIFHEAD: 670 if (*(int *)data) { 671 tp->tun_flags |= TUN_IFHEAD; 672 tp->tun_flags &= ~TUN_PREPADDR; 673 } else 674 tp->tun_flags &= ~TUN_IFHEAD; 675 break; 676 677 case TUNGIFHEAD: 678 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 679 break; 680 681 case FIONBIO: 682 if (*(int *)data) 683 tp->tun_flags |= TUN_NBIO; 684 else 685 tp->tun_flags &= ~TUN_NBIO; 686 break; 687 688 case FIOASYNC: 689 if (*(int *)data) 690 tp->tun_flags |= TUN_ASYNC; 691 else 692 tp->tun_flags &= ~TUN_ASYNC; 693 break; 694 695 case FIONREAD: 696 if (tp->tun_if.if_snd.ifq_head) 697 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 698 else 699 *(int *)data = 0; 700 break; 701 702 case TIOCSPGRP: 703 case FIOSETOWN: 704 error = fsetown(&tp->tun_pgid, cmd, data); 705 break; 706 707 case TIOCGPGRP: 708 case FIOGETOWN: 709 error = fgetown(tp->tun_pgid, cmd, data); 710 break; 711 712 default: 713 error = ENOTTY; 714 } 715 716 out: 717 mutex_exit(&tp->tun_lock); 718 out_nolock: 719 splx(s); 720 return (error); 721 } 722 723 /* 724 * The cdevsw read interface - reads a packet at a time, or at 725 * least as much of a packet as can be read. 726 */ 727 int 728 tunread(dev_t dev, struct uio *uio, int ioflag) 729 { 730 struct tun_softc *tp; 731 struct ifnet *ifp; 732 struct mbuf *m, *m0; 733 int error = 0, len, s, index; 734 735 s = splnet(); 736 tp = tun_find_unit(dev); 737 738 /* interface was "destroyed" already */ 739 if (tp == NULL) { 740 error = ENXIO; 741 goto out_nolock; 742 } 743 744 index = tp->tun_if.if_index; 745 ifp = &tp->tun_if; 746 747 TUNDEBUG ("%s: read\n", ifp->if_xname); 748 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 749 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 750 error = EHOSTDOWN; 751 goto out; 752 } 753 754 tp->tun_flags &= ~TUN_RWAIT; 755 756 do { 757 IFQ_DEQUEUE(&ifp->if_snd, m0); 758 if (m0 == 0) { 759 if (tp->tun_flags & TUN_NBIO) { 760 error = EWOULDBLOCK; 761 goto out; 762 } 763 tp->tun_flags |= TUN_RWAIT; 764 if (mtsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 765 "tunread", 0, &tp->tun_lock) != 0) { 766 error = EINTR; 767 goto out_nolock; 768 } else { 769 /* 770 * Maybe the interface was destroyed while 771 * we were sleeping, so let's ensure that 772 * we're looking at the same (valid) tun 773 * interface before looping. 774 */ 775 tp = tun_find_unit(dev); 776 if (tp == NULL) { 777 error = ENXIO; 778 goto out_nolock; 779 } 780 if (tp->tun_if.if_index != index) { 781 error = ENXIO; 782 goto out; 783 } 784 } 785 } 786 } while (m0 == 0); 787 788 mutex_exit(&tp->tun_lock); 789 splx(s); 790 791 /* Copy the mbuf chain */ 792 while (m0 && uio->uio_resid > 0 && error == 0) { 793 len = min(uio->uio_resid, m0->m_len); 794 if (len != 0) 795 error = uiomove(mtod(m0, void *), len, uio); 796 MFREE(m0, m); 797 m0 = m; 798 } 799 800 if (m0) { 801 TUNDEBUG("Dropping mbuf\n"); 802 m_freem(m0); 803 } 804 if (error) 805 ifp->if_ierrors++; 806 807 return (error); 808 809 out: 810 mutex_exit(&tp->tun_lock); 811 out_nolock: 812 splx(s); 813 return (error); 814 } 815 816 /* 817 * the cdevsw write interface - an atomic write is a packet - or else! 818 */ 819 int 820 tunwrite(dev_t dev, struct uio *uio, int ioflag) 821 { 822 struct tun_softc *tp; 823 struct ifnet *ifp; 824 struct mbuf *top, **mp, *m; 825 pktqueue_t *pktq; 826 struct sockaddr dst; 827 int error = 0, s, tlen, mlen; 828 uint32_t family; 829 830 s = splnet(); 831 tp = tun_find_unit(dev); 832 833 /* interface was "destroyed" already */ 834 if (tp == NULL) { 835 error = ENXIO; 836 goto out_nolock; 837 } 838 839 /* Unlock until we've got the data */ 840 mutex_exit(&tp->tun_lock); 841 splx(s); 842 843 ifp = &tp->tun_if; 844 845 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 846 847 if (tp->tun_flags & TUN_PREPADDR) { 848 if (uio->uio_resid < sizeof(dst)) { 849 error = EIO; 850 goto out0; 851 } 852 error = uiomove((void *)&dst, sizeof(dst), uio); 853 if (dst.sa_len > sizeof(dst)) { 854 /* Duh.. */ 855 char discard; 856 int n = dst.sa_len - sizeof(dst); 857 while (n--) 858 if ((error = uiomove(&discard, 1, uio)) != 0) { 859 goto out0; 860 } 861 } 862 } else if (tp->tun_flags & TUN_IFHEAD) { 863 if (uio->uio_resid < sizeof(family)){ 864 error = EIO; 865 goto out0; 866 } 867 error = uiomove((void *)&family, sizeof(family), uio); 868 dst.sa_family = ntohl(family); 869 } else { 870 #ifdef INET 871 dst.sa_family = AF_INET; 872 #endif 873 } 874 875 if (uio->uio_resid > TUNMTU) { 876 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 877 (unsigned long)uio->uio_resid); 878 error = EIO; 879 goto out0; 880 } 881 882 switch (dst.sa_family) { 883 #ifdef INET 884 case AF_INET: 885 pktq = ip_pktq; 886 break; 887 #endif 888 #ifdef INET6 889 case AF_INET6: 890 pktq = ip6_pktq; 891 break; 892 #endif 893 default: 894 error = EAFNOSUPPORT; 895 goto out0; 896 } 897 898 tlen = uio->uio_resid; 899 900 /* get a header mbuf */ 901 MGETHDR(m, M_DONTWAIT, MT_DATA); 902 if (m == NULL) { 903 error = ENOBUFS; 904 goto out0; 905 } 906 mlen = MHLEN; 907 908 top = NULL; 909 mp = ⊤ 910 while (error == 0 && uio->uio_resid > 0) { 911 m->m_len = min(mlen, uio->uio_resid); 912 error = uiomove(mtod(m, void *), m->m_len, uio); 913 *mp = m; 914 mp = &m->m_next; 915 if (error == 0 && uio->uio_resid > 0) { 916 MGET(m, M_DONTWAIT, MT_DATA); 917 if (m == NULL) { 918 error = ENOBUFS; 919 break; 920 } 921 mlen = MLEN; 922 } 923 } 924 if (error) { 925 if (top != NULL) 926 m_freem (top); 927 ifp->if_ierrors++; 928 goto out0; 929 } 930 931 top->m_pkthdr.len = tlen; 932 top->m_pkthdr.rcvif = ifp; 933 934 bpf_mtap_af(ifp, dst.sa_family, top); 935 936 s = splnet(); 937 mutex_enter(&tp->tun_lock); 938 if ((tp->tun_flags & TUN_INITED) == 0) { 939 /* Interface was destroyed */ 940 error = ENXIO; 941 goto out; 942 } 943 if (__predict_false(!pktq_enqueue(pktq, m, 0))) { 944 ifp->if_collisions++; 945 mutex_exit(&tp->tun_lock); 946 error = ENOBUFS; 947 m_freem(m); 948 goto out_nolock; 949 } 950 ifp->if_ipackets++; 951 ifp->if_ibytes += tlen; 952 out: 953 mutex_exit(&tp->tun_lock); 954 out_nolock: 955 splx(s); 956 out0: 957 return (error); 958 } 959 960 #ifdef ALTQ 961 /* 962 * Start packet transmission on the interface. 963 * when the interface queue is rate-limited by ALTQ or TBR, 964 * if_start is needed to drain packets from the queue in order 965 * to notify readers when outgoing packets become ready. 966 * 967 * Should be called at splnet. 968 */ 969 static void 970 tunstart(struct ifnet *ifp) 971 { 972 struct tun_softc *tp = ifp->if_softc; 973 974 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 975 return; 976 977 mutex_enter(&tp->tun_lock); 978 if (!IF_IS_EMPTY(&ifp->if_snd)) { 979 if (tp->tun_flags & TUN_RWAIT) { 980 tp->tun_flags &= ~TUN_RWAIT; 981 wakeup((void *)tp); 982 } 983 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 984 softint_schedule(tp->tun_osih); 985 986 selnotify(&tp->tun_rsel, 0, 0); 987 } 988 mutex_exit(&tp->tun_lock); 989 } 990 #endif /* ALTQ */ 991 /* 992 * tunpoll - the poll interface, this is only useful on reads 993 * really. The write detect always returns true, write never blocks 994 * anyway, it either accepts the packet or drops it. 995 */ 996 int 997 tunpoll(dev_t dev, int events, struct lwp *l) 998 { 999 struct tun_softc *tp; 1000 struct ifnet *ifp; 1001 int s, revents = 0; 1002 1003 s = splnet(); 1004 tp = tun_find_unit(dev); 1005 1006 /* interface was "destroyed" already */ 1007 if (tp == NULL) 1008 goto out_nolock; 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 out_nolock: 1030 splx(s); 1031 return (revents); 1032 } 1033 1034 static void 1035 filt_tunrdetach(struct knote *kn) 1036 { 1037 struct tun_softc *tp = kn->kn_hook; 1038 int s; 1039 1040 s = splnet(); 1041 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1042 splx(s); 1043 } 1044 1045 static int 1046 filt_tunread(struct knote *kn, long hint) 1047 { 1048 struct tun_softc *tp = kn->kn_hook; 1049 struct ifnet *ifp = &tp->tun_if; 1050 struct mbuf *m; 1051 int s; 1052 1053 s = splnet(); 1054 IF_POLL(&ifp->if_snd, m); 1055 if (m == NULL) { 1056 splx(s); 1057 return (0); 1058 } 1059 1060 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1061 kn->kn_data += m->m_len; 1062 1063 splx(s); 1064 return (1); 1065 } 1066 1067 static const struct filterops tunread_filtops = 1068 { 1, NULL, filt_tunrdetach, filt_tunread }; 1069 1070 static const struct filterops tun_seltrue_filtops = 1071 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1072 1073 int 1074 tunkqfilter(dev_t dev, struct knote *kn) 1075 { 1076 struct tun_softc *tp; 1077 struct klist *klist; 1078 int rv = 0, s; 1079 1080 s = splnet(); 1081 tp = tun_find_unit(dev); 1082 if (tp == NULL) 1083 goto out_nolock; 1084 1085 switch (kn->kn_filter) { 1086 case EVFILT_READ: 1087 klist = &tp->tun_rsel.sel_klist; 1088 kn->kn_fop = &tunread_filtops; 1089 break; 1090 1091 case EVFILT_WRITE: 1092 klist = &tp->tun_rsel.sel_klist; 1093 kn->kn_fop = &tun_seltrue_filtops; 1094 break; 1095 1096 default: 1097 rv = EINVAL; 1098 goto out; 1099 } 1100 1101 kn->kn_hook = tp; 1102 1103 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1104 1105 out: 1106 mutex_exit(&tp->tun_lock); 1107 out_nolock: 1108 splx(s); 1109 return (rv); 1110 } 1111
Indexes created Tue Sep 23 14:10:03 GMT 2025