if_tun.c revision 1.107
1 /* $NetBSD: if_tun.c,v 1.107 2008/06/15 16:37:21 christos 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 1.107 2008/06/15 16:37:21 christos 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 "bpfilter.h" 57 #if NBPFILTER > 0 58 #include <sys/time.h> 59 #include <net/bpf.h> 60 #endif 61 62 #include <net/if_tun.h> 63 64 #define TUNDEBUG if (tundebug) printf 65 int tundebug = 0; 66 67 extern int ifqmaxlen; 68 void tunattach(int); 69 70 static LIST_HEAD(, tun_softc) tun_softc_list; 71 static LIST_HEAD(, tun_softc) tunz_softc_list; 72 static struct simplelock 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 tunopen, tunclose, tunread, tunwrite, tunioctl, 103 nostop, notty, tunpoll, nommap, tunkqfilter, D_OTHER, 104 }; 105 106 void 107 tunattach(int unused) 108 { 109 110 simple_lock_init(&tun_softc_lock); 111 LIST_INIT(&tun_softc_list); 112 LIST_INIT(&tunz_softc_list); 113 if_clone_attach(&tun_cloner); 114 } 115 116 /* 117 * Find driver instance from dev_t. 118 * Call at splnet(). 119 * Returns with tp locked (if found). 120 */ 121 static struct tun_softc * 122 tun_find_unit(dev_t dev) 123 { 124 struct tun_softc *tp; 125 int unit = minor(dev); 126 127 simple_lock(&tun_softc_lock); 128 LIST_FOREACH(tp, &tun_softc_list, tun_list) 129 if (unit == tp->tun_unit) 130 break; 131 if (tp) 132 simple_lock(&tp->tun_lock); 133 simple_unlock(&tun_softc_lock); 134 135 return (tp); 136 } 137 138 /* 139 * Find zombie driver instance by unit number. 140 * Call at splnet(). 141 * Remove tp from list and return it unlocked (if found). 142 */ 143 static struct tun_softc * 144 tun_find_zunit(int unit) 145 { 146 struct tun_softc *tp; 147 148 simple_lock(&tun_softc_lock); 149 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 150 if (unit == tp->tun_unit) 151 break; 152 if (tp) 153 LIST_REMOVE(tp, tun_list); 154 simple_unlock(&tun_softc_lock); 155 #ifdef DIAGNOSTIC 156 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 157 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 158 #endif 159 160 return (tp); 161 } 162 163 static int 164 tun_clone_create(struct if_clone *ifc, int unit) 165 { 166 struct tun_softc *tp; 167 168 if ((tp = tun_find_zunit(unit)) == NULL) { 169 /* Allocate a new instance */ 170 tp = malloc(sizeof(*tp), M_DEVBUF, M_WAITOK|M_ZERO); 171 172 tp->tun_unit = unit; 173 simple_lock_init(&tp->tun_lock); 174 selinit(&tp->tun_rsel); 175 selinit(&tp->tun_wsel); 176 } else { 177 /* Revive tunnel instance; clear ifp part */ 178 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 179 } 180 181 if_initname(&tp->tun_if, ifc->ifc_name, unit); 182 tunattach0(tp); 183 tp->tun_flags |= TUN_INITED; 184 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 185 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 186 187 simple_lock(&tun_softc_lock); 188 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 189 simple_unlock(&tun_softc_lock); 190 191 return (0); 192 } 193 194 static void 195 tunattach0(struct tun_softc *tp) 196 { 197 struct ifnet *ifp; 198 199 ifp = &tp->tun_if; 200 ifp->if_softc = tp; 201 ifp->if_mtu = TUNMTU; 202 ifp->if_ioctl = tun_ioctl; 203 ifp->if_output = tun_output; 204 #ifdef ALTQ 205 ifp->if_start = tunstart; 206 #endif 207 ifp->if_flags = IFF_POINTOPOINT; 208 ifp->if_type = IFT_TUNNEL; 209 ifp->if_snd.ifq_maxlen = ifqmaxlen; 210 ifp->if_collisions = 0; 211 ifp->if_ierrors = 0; 212 ifp->if_oerrors = 0; 213 ifp->if_ipackets = 0; 214 ifp->if_opackets = 0; 215 ifp->if_ibytes = 0; 216 ifp->if_obytes = 0; 217 ifp->if_dlt = DLT_NULL; 218 IFQ_SET_READY(&ifp->if_snd); 219 if_attach(ifp); 220 if_alloc_sadl(ifp); 221 #if NBPFILTER > 0 222 bpfattach(ifp, DLT_NULL, sizeof(uint32_t)); 223 #endif 224 } 225 226 static int 227 tun_clone_destroy(struct ifnet *ifp) 228 { 229 struct tun_softc *tp = (void *)ifp; 230 int s, zombie = 0; 231 232 s = splnet(); 233 simple_lock(&tun_softc_lock); 234 simple_lock(&tp->tun_lock); 235 LIST_REMOVE(tp, tun_list); 236 if (tp->tun_flags & TUN_OPEN) { 237 /* Hang on to storage until last close */ 238 zombie = 1; 239 tp->tun_flags &= ~TUN_INITED; 240 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 241 } 242 simple_unlock(&tun_softc_lock); 243 244 IF_PURGE(&ifp->if_snd); 245 ifp->if_flags &= ~IFF_RUNNING; 246 247 if (tp->tun_flags & TUN_RWAIT) { 248 tp->tun_flags &= ~TUN_RWAIT; 249 wakeup((void *)tp); 250 } 251 selnotify(&tp->tun_rsel, 0, 0); 252 253 simple_unlock(&tp->tun_lock); 254 splx(s); 255 256 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 257 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 258 259 #if NBPFILTER > 0 260 bpfdetach(ifp); 261 #endif 262 if_detach(ifp); 263 264 if (!zombie) { 265 seldestroy(&tp->tun_rsel); 266 seldestroy(&tp->tun_wsel); 267 softint_disestablish(tp->tun_osih); 268 softint_disestablish(tp->tun_isih); 269 free(tp, M_DEVBUF); 270 } 271 272 return (0); 273 } 274 275 /* 276 * tunnel open - must be superuser & the device must be 277 * configured in 278 */ 279 static int 280 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 281 { 282 struct ifnet *ifp; 283 struct tun_softc *tp; 284 int s, error; 285 286 if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, 287 NULL)) != 0) 288 return (error); 289 290 s = splnet(); 291 tp = tun_find_unit(dev); 292 293 if (tp == NULL) { 294 (void)tun_clone_create(&tun_cloner, minor(dev)); 295 tp = tun_find_unit(dev); 296 if (tp == NULL) { 297 error = ENXIO; 298 goto out_nolock; 299 } 300 } 301 302 if (tp->tun_flags & TUN_OPEN) { 303 error = EBUSY; 304 goto out; 305 } 306 307 ifp = &tp->tun_if; 308 tp->tun_flags |= TUN_OPEN; 309 TUNDEBUG("%s: open\n", ifp->if_xname); 310 out: 311 simple_unlock(&tp->tun_lock); 312 out_nolock: 313 splx(s); 314 return (error); 315 } 316 317 /* 318 * tunclose - close the device - mark i/f down & delete 319 * routing info 320 */ 321 int 322 tunclose(dev_t dev, int flag, int mode, 323 struct lwp *l) 324 { 325 int s; 326 struct tun_softc *tp; 327 struct ifnet *ifp; 328 329 s = splnet(); 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 free(tp, M_DEVBUF); 337 goto out_nolock; 338 } 339 340 if ((tp = tun_find_unit(dev)) == NULL) 341 goto out_nolock; 342 343 ifp = &tp->tun_if; 344 345 tp->tun_flags &= ~TUN_OPEN; 346 347 /* 348 * junk all pending output 349 */ 350 IFQ_PURGE(&ifp->if_snd); 351 352 if (ifp->if_flags & IFF_UP) { 353 if_down(ifp); 354 if (ifp->if_flags & IFF_RUNNING) { 355 /* find internet addresses and delete routes */ 356 struct ifaddr *ifa; 357 IFADDR_FOREACH(ifa, ifp) { 358 #if defined(INET) || defined(INET6) 359 if (ifa->ifa_addr->sa_family == AF_INET || 360 ifa->ifa_addr->sa_family == AF_INET6) { 361 rtinit(ifa, (int)RTM_DELETE, 362 tp->tun_flags & TUN_DSTADDR 363 ? RTF_HOST 364 : 0); 365 } 366 #endif 367 } 368 } 369 } 370 tp->tun_pgid = 0; 371 selnotify(&tp->tun_rsel, 0, 0); 372 373 TUNDEBUG ("%s: closed\n", ifp->if_xname); 374 simple_unlock(&tp->tun_lock); 375 out_nolock: 376 splx(s); 377 return (0); 378 } 379 380 /* 381 * Call at splnet() with tp locked. 382 */ 383 static void 384 tuninit(struct tun_softc *tp) 385 { 386 struct ifnet *ifp = &tp->tun_if; 387 struct ifaddr *ifa; 388 389 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 390 391 ifp->if_flags |= IFF_UP | IFF_RUNNING; 392 393 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 394 IFADDR_FOREACH(ifa, ifp) { 395 #ifdef INET 396 if (ifa->ifa_addr->sa_family == AF_INET) { 397 struct sockaddr_in *sin; 398 399 sin = satosin(ifa->ifa_addr); 400 if (sin && sin->sin_addr.s_addr) 401 tp->tun_flags |= TUN_IASET; 402 403 if (ifp->if_flags & IFF_POINTOPOINT) { 404 sin = satosin(ifa->ifa_dstaddr); 405 if (sin && sin->sin_addr.s_addr) 406 tp->tun_flags |= TUN_DSTADDR; 407 } 408 } 409 #endif 410 #ifdef INET6 411 if (ifa->ifa_addr->sa_family == AF_INET6) { 412 struct sockaddr_in6 *sin; 413 414 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 415 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 416 tp->tun_flags |= TUN_IASET; 417 418 if (ifp->if_flags & IFF_POINTOPOINT) { 419 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 420 if (sin && 421 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 422 tp->tun_flags |= TUN_DSTADDR; 423 } else 424 tp->tun_flags &= ~TUN_DSTADDR; 425 } 426 #endif /* INET6 */ 427 } 428 429 return; 430 } 431 432 /* 433 * Process an ioctl request. 434 */ 435 static int 436 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 437 { 438 int error = 0, s; 439 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 440 struct ifreq *ifr = data; 441 442 s = splnet(); 443 simple_lock(&tp->tun_lock); 444 445 switch (cmd) { 446 case SIOCSIFADDR: 447 tuninit(tp); 448 TUNDEBUG("%s: address set\n", ifp->if_xname); 449 break; 450 case SIOCSIFDSTADDR: 451 tuninit(tp); 452 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 453 break; 454 case SIOCSIFBRDADDR: 455 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 456 break; 457 case SIOCSIFMTU: 458 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 459 error = EINVAL; 460 break; 461 } 462 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 463 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 464 error = 0; 465 break; 466 case SIOCADDMULTI: 467 case SIOCDELMULTI: 468 if (ifr == NULL) { 469 error = EAFNOSUPPORT; /* XXX */ 470 break; 471 } 472 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 473 #ifdef INET 474 case AF_INET: 475 break; 476 #endif 477 #ifdef INET6 478 case AF_INET6: 479 break; 480 #endif 481 default: 482 error = EAFNOSUPPORT; 483 break; 484 } 485 break; 486 case SIOCSIFFLAGS: 487 break; 488 default: 489 error = EINVAL; 490 } 491 492 simple_unlock(&tp->tun_lock); 493 splx(s); 494 return (error); 495 } 496 497 /* 498 * tun_output - queue packets from higher level ready to put out. 499 */ 500 static int 501 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 502 struct rtentry *rt) 503 { 504 struct tun_softc *tp = ifp->if_softc; 505 int s; 506 int error; 507 #if defined(INET) || defined(INET6) 508 int mlen; 509 uint32_t *af; 510 #endif 511 ALTQ_DECL(struct altq_pktattr pktattr;) 512 513 s = splnet(); 514 simple_lock(&tp->tun_lock); 515 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 516 517 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 518 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 519 tp->tun_flags); 520 m_freem (m0); 521 error = EHOSTDOWN; 522 goto out; 523 } 524 525 /* 526 * if the queueing discipline needs packet classification, 527 * do it before prepending link headers. 528 */ 529 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 530 531 #if NBPFILTER > 0 532 if (ifp->if_bpf) 533 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0); 534 #endif 535 536 switch(dst->sa_family) { 537 #ifdef INET6 538 case AF_INET6: 539 #endif 540 #ifdef INET 541 case AF_INET: 542 #endif 543 #if defined(INET) || defined(INET6) 544 if (tp->tun_flags & TUN_PREPADDR) { 545 /* Simple link-layer header */ 546 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 547 if (m0 == NULL) { 548 IF_DROP(&ifp->if_snd); 549 error = ENOBUFS; 550 goto out; 551 } 552 bcopy(dst, mtod(m0, char *), dst->sa_len); 553 } 554 555 if (tp->tun_flags & TUN_IFHEAD) { 556 /* Prepend the address family */ 557 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 558 if (m0 == NULL) { 559 IF_DROP(&ifp->if_snd); 560 error = ENOBUFS; 561 goto out; 562 } 563 af = mtod(m0,uint32_t *); 564 *af = htonl(dst->sa_family); 565 } else { 566 #ifdef INET 567 if (dst->sa_family != AF_INET) 568 #endif 569 { 570 m_freem(m0); 571 error = EAFNOSUPPORT; 572 goto out; 573 } 574 } 575 /* FALLTHROUGH */ 576 case AF_UNSPEC: 577 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 578 if (error) { 579 ifp->if_collisions++; 580 error = EAFNOSUPPORT; 581 goto out; 582 } 583 mlen = m0->m_pkthdr.len; 584 ifp->if_opackets++; 585 ifp->if_obytes += mlen; 586 break; 587 #endif 588 default: 589 m_freem(m0); 590 error = EAFNOSUPPORT; 591 goto out; 592 } 593 594 if (tp->tun_flags & TUN_RWAIT) { 595 tp->tun_flags &= ~TUN_RWAIT; 596 wakeup((void *)tp); 597 } 598 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 599 softint_schedule(tp->tun_isih); 600 601 selnotify(&tp->tun_rsel, 0, 0); 602 out: 603 simple_unlock(&tp->tun_lock); 604 splx(s); 605 return (0); 606 } 607 608 static void 609 tun_i_softintr(void *cookie) 610 { 611 struct tun_softc *tp = cookie; 612 613 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 614 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 615 NULL); 616 } 617 618 static void 619 tun_o_softintr(void *cookie) 620 { 621 struct tun_softc *tp = cookie; 622 623 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 624 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 625 NULL); 626 } 627 628 /* 629 * the cdevsw interface is now pretty minimal. 630 */ 631 int 632 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 633 { 634 struct tun_softc *tp; 635 int s, error = 0; 636 637 s = splnet(); 638 tp = tun_find_unit(dev); 639 640 /* interface was "destroyed" already */ 641 if (tp == NULL) { 642 error = ENXIO; 643 goto out_nolock; 644 } 645 646 switch (cmd) { 647 case TUNSDEBUG: 648 tundebug = *(int *)data; 649 break; 650 651 case TUNGDEBUG: 652 *(int *)data = tundebug; 653 break; 654 655 case TUNSIFMODE: 656 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 657 case IFF_POINTOPOINT: 658 case IFF_BROADCAST: 659 if (tp->tun_if.if_flags & IFF_UP) { 660 error = EBUSY; 661 goto out; 662 } 663 tp->tun_if.if_flags &= 664 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 665 tp->tun_if.if_flags |= *(int *)data; 666 break; 667 default: 668 error = EINVAL; 669 goto out; 670 } 671 break; 672 673 case TUNSLMODE: 674 if (*(int *)data) { 675 tp->tun_flags |= TUN_PREPADDR; 676 tp->tun_flags &= ~TUN_IFHEAD; 677 } else 678 tp->tun_flags &= ~TUN_PREPADDR; 679 break; 680 681 case TUNSIFHEAD: 682 if (*(int *)data) { 683 tp->tun_flags |= TUN_IFHEAD; 684 tp->tun_flags &= ~TUN_PREPADDR; 685 } else 686 tp->tun_flags &= ~TUN_IFHEAD; 687 break; 688 689 case TUNGIFHEAD: 690 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 691 break; 692 693 case FIONBIO: 694 if (*(int *)data) 695 tp->tun_flags |= TUN_NBIO; 696 else 697 tp->tun_flags &= ~TUN_NBIO; 698 break; 699 700 case FIOASYNC: 701 if (*(int *)data) 702 tp->tun_flags |= TUN_ASYNC; 703 else 704 tp->tun_flags &= ~TUN_ASYNC; 705 break; 706 707 case FIONREAD: 708 if (tp->tun_if.if_snd.ifq_head) 709 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 710 else 711 *(int *)data = 0; 712 break; 713 714 case TIOCSPGRP: 715 case FIOSETOWN: 716 error = fsetown(&tp->tun_pgid, cmd, data); 717 break; 718 719 case TIOCGPGRP: 720 case FIOGETOWN: 721 error = fgetown(tp->tun_pgid, cmd, data); 722 break; 723 724 default: 725 error = ENOTTY; 726 } 727 728 out: 729 simple_unlock(&tp->tun_lock); 730 out_nolock: 731 splx(s); 732 return (error); 733 } 734 735 /* 736 * The cdevsw read interface - reads a packet at a time, or at 737 * least as much of a packet as can be read. 738 */ 739 int 740 tunread(dev_t dev, struct uio *uio, int ioflag) 741 { 742 struct tun_softc *tp; 743 struct ifnet *ifp; 744 struct mbuf *m, *m0; 745 int error = 0, len, s, index; 746 747 s = splnet(); 748 tp = tun_find_unit(dev); 749 750 /* interface was "destroyed" already */ 751 if (tp == NULL) { 752 error = ENXIO; 753 goto out_nolock; 754 } 755 756 index = tp->tun_if.if_index; 757 ifp = &tp->tun_if; 758 759 TUNDEBUG ("%s: read\n", ifp->if_xname); 760 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 761 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 762 error = EHOSTDOWN; 763 goto out; 764 } 765 766 tp->tun_flags &= ~TUN_RWAIT; 767 768 do { 769 IFQ_DEQUEUE(&ifp->if_snd, m0); 770 if (m0 == 0) { 771 if (tp->tun_flags & TUN_NBIO) { 772 error = EWOULDBLOCK; 773 goto out; 774 } 775 tp->tun_flags |= TUN_RWAIT; 776 if (ltsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 777 "tunread", 0, &tp->tun_lock) != 0) { 778 error = EINTR; 779 goto out_nolock; 780 } else { 781 /* 782 * Maybe the interface was destroyed while 783 * we were sleeping, so let's ensure that 784 * we're looking at the same (valid) tun 785 * interface before looping. 786 */ 787 tp = tun_find_unit(dev); 788 if (tp == NULL) { 789 error = ENXIO; 790 goto out_nolock; 791 } 792 if (tp->tun_if.if_index != index) { 793 error = ENXIO; 794 goto out; 795 } 796 } 797 } 798 } while (m0 == 0); 799 800 simple_unlock(&tp->tun_lock); 801 splx(s); 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 MFREE(m0, m); 809 m0 = m; 810 } 811 812 if (m0) { 813 TUNDEBUG("Dropping mbuf\n"); 814 m_freem(m0); 815 } 816 if (error) 817 ifp->if_ierrors++; 818 819 return (error); 820 821 out: 822 simple_unlock(&tp->tun_lock); 823 out_nolock: 824 splx(s); 825 return (error); 826 } 827 828 /* 829 * the cdevsw write interface - an atomic write is a packet - or else! 830 */ 831 int 832 tunwrite(dev_t dev, struct uio *uio, int ioflag) 833 { 834 struct tun_softc *tp; 835 struct ifnet *ifp; 836 struct mbuf *top, **mp, *m; 837 struct ifqueue *ifq; 838 struct sockaddr dst; 839 int isr, error = 0, s, tlen, mlen; 840 uint32_t family; 841 842 s = splnet(); 843 tp = tun_find_unit(dev); 844 845 /* interface was "destroyed" already */ 846 if (tp == NULL) { 847 error = ENXIO; 848 goto out_nolock; 849 } 850 851 /* Unlock until we've got the data */ 852 simple_unlock(&tp->tun_lock); 853 splx(s); 854 855 ifp = &tp->tun_if; 856 857 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 858 859 if (tp->tun_flags & TUN_PREPADDR) { 860 if (uio->uio_resid < sizeof(dst)) { 861 error = EIO; 862 goto out0; 863 } 864 error = uiomove((void *)&dst, sizeof(dst), uio); 865 if (dst.sa_len > sizeof(dst)) { 866 /* Duh.. */ 867 char discard; 868 int n = dst.sa_len - sizeof(dst); 869 while (n--) 870 if ((error = uiomove(&discard, 1, uio)) != 0) { 871 goto out0; 872 } 873 } 874 } else if (tp->tun_flags & TUN_IFHEAD) { 875 if (uio->uio_resid < sizeof(family)){ 876 error = EIO; 877 goto out0; 878 } 879 error = uiomove((void *)&family, sizeof(family), uio); 880 dst.sa_family = ntohl(family); 881 } else { 882 #ifdef INET 883 dst.sa_family = AF_INET; 884 #endif 885 } 886 887 if (uio->uio_resid > TUNMTU) { 888 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 889 (unsigned long)uio->uio_resid); 890 error = EIO; 891 goto out0; 892 } 893 894 switch (dst.sa_family) { 895 #ifdef INET 896 case AF_INET: 897 ifq = &ipintrq; 898 isr = NETISR_IP; 899 break; 900 #endif 901 #ifdef INET6 902 case AF_INET6: 903 ifq = &ip6intrq; 904 isr = NETISR_IPV6; 905 break; 906 #endif 907 default: 908 error = EAFNOSUPPORT; 909 goto out0; 910 } 911 912 tlen = uio->uio_resid; 913 914 /* get a header mbuf */ 915 MGETHDR(m, M_DONTWAIT, MT_DATA); 916 if (m == NULL) { 917 error = ENOBUFS; 918 goto out0; 919 } 920 mlen = MHLEN; 921 922 top = NULL; 923 mp = ⊤ 924 while (error == 0 && uio->uio_resid > 0) { 925 m->m_len = min(mlen, uio->uio_resid); 926 error = uiomove(mtod(m, void *), m->m_len, uio); 927 *mp = m; 928 mp = &m->m_next; 929 if (error == 0 && uio->uio_resid > 0) { 930 MGET(m, M_DONTWAIT, MT_DATA); 931 if (m == NULL) { 932 error = ENOBUFS; 933 break; 934 } 935 mlen = MLEN; 936 } 937 } 938 if (error) { 939 if (top != NULL) 940 m_freem (top); 941 ifp->if_ierrors++; 942 goto out0; 943 } 944 945 top->m_pkthdr.len = tlen; 946 top->m_pkthdr.rcvif = ifp; 947 948 #if NBPFILTER > 0 949 if (ifp->if_bpf) 950 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 951 #endif 952 953 s = splnet(); 954 simple_lock(&tp->tun_lock); 955 if ((tp->tun_flags & TUN_INITED) == 0) { 956 /* Interface was destroyed */ 957 error = ENXIO; 958 goto out; 959 } 960 if (IF_QFULL(ifq)) { 961 IF_DROP(ifq); 962 ifp->if_collisions++; 963 m_freem(top); 964 error = ENOBUFS; 965 goto out; 966 } 967 968 IF_ENQUEUE(ifq, top); 969 ifp->if_ipackets++; 970 ifp->if_ibytes += tlen; 971 schednetisr(isr); 972 out: 973 simple_unlock(&tp->tun_lock); 974 out_nolock: 975 splx(s); 976 out0: 977 return (error); 978 } 979 980 #ifdef ALTQ 981 /* 982 * Start packet transmission on the interface. 983 * when the interface queue is rate-limited by ALTQ or TBR, 984 * if_start is needed to drain packets from the queue in order 985 * to notify readers when outgoing packets become ready. 986 * 987 * Should be called at splnet. 988 */ 989 static void 990 tunstart(struct ifnet *ifp) 991 { 992 struct tun_softc *tp = ifp->if_softc; 993 994 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 995 return; 996 997 simple_lock(&tp->tun_lock); 998 if (!IF_IS_EMPTY(&ifp->if_snd)) { 999 if (tp->tun_flags & TUN_RWAIT) { 1000 tp->tun_flags &= ~TUN_RWAIT; 1001 wakeup((void *)tp); 1002 } 1003 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 1004 softint_schedule(tp->tun_osih); 1005 1006 selnotify(&tp->tun_rsel, 0, 0); 1007 } 1008 simple_unlock(&tp->tun_lock); 1009 } 1010 #endif /* ALTQ */ 1011 /* 1012 * tunpoll - the poll interface, this is only useful on reads 1013 * really. The write detect always returns true, write never blocks 1014 * anyway, it either accepts the packet or drops it. 1015 */ 1016 int 1017 tunpoll(dev_t dev, int events, struct lwp *l) 1018 { 1019 struct tun_softc *tp; 1020 struct ifnet *ifp; 1021 int s, revents = 0; 1022 1023 s = splnet(); 1024 tp = tun_find_unit(dev); 1025 1026 /* interface was "destroyed" already */ 1027 if (tp == NULL) 1028 goto out_nolock; 1029 1030 ifp = &tp->tun_if; 1031 1032 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1033 1034 if (events & (POLLIN | POLLRDNORM)) { 1035 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1036 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1037 ifp->if_snd.ifq_len); 1038 revents |= events & (POLLIN | POLLRDNORM); 1039 } else { 1040 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1041 selrecord(l, &tp->tun_rsel); 1042 } 1043 } 1044 1045 if (events & (POLLOUT | POLLWRNORM)) 1046 revents |= events & (POLLOUT | POLLWRNORM); 1047 1048 simple_unlock(&tp->tun_lock); 1049 out_nolock: 1050 splx(s); 1051 return (revents); 1052 } 1053 1054 static void 1055 filt_tunrdetach(struct knote *kn) 1056 { 1057 struct tun_softc *tp = kn->kn_hook; 1058 int s; 1059 1060 s = splnet(); 1061 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1062 splx(s); 1063 } 1064 1065 static int 1066 filt_tunread(struct knote *kn, long hint) 1067 { 1068 struct tun_softc *tp = kn->kn_hook; 1069 struct ifnet *ifp = &tp->tun_if; 1070 struct mbuf *m; 1071 int s; 1072 1073 s = splnet(); 1074 IF_POLL(&ifp->if_snd, m); 1075 if (m == NULL) { 1076 splx(s); 1077 return (0); 1078 } 1079 1080 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1081 kn->kn_data += m->m_len; 1082 1083 splx(s); 1084 return (1); 1085 } 1086 1087 static const struct filterops tunread_filtops = 1088 { 1, NULL, filt_tunrdetach, filt_tunread }; 1089 1090 static const struct filterops tun_seltrue_filtops = 1091 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1092 1093 int 1094 tunkqfilter(dev_t dev, struct knote *kn) 1095 { 1096 struct tun_softc *tp; 1097 struct klist *klist; 1098 int rv = 0, s; 1099 1100 s = splnet(); 1101 tp = tun_find_unit(dev); 1102 if (tp == NULL) 1103 goto out_nolock; 1104 1105 switch (kn->kn_filter) { 1106 case EVFILT_READ: 1107 klist = &tp->tun_rsel.sel_klist; 1108 kn->kn_fop = &tunread_filtops; 1109 break; 1110 1111 case EVFILT_WRITE: 1112 klist = &tp->tun_rsel.sel_klist; 1113 kn->kn_fop = &tun_seltrue_filtops; 1114 break; 1115 1116 default: 1117 rv = EINVAL; 1118 goto out; 1119 } 1120 1121 kn->kn_hook = tp; 1122 1123 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1124 1125 out: 1126 simple_unlock(&tp->tun_lock); 1127 out_nolock: 1128 splx(s); 1129 return (rv); 1130 } 1131
Indexes created Tue Sep 23 02:09:52 GMT 2025