if_tun.c revision 1.108
1 /* $NetBSD: if_tun.c,v 1.108 2008/11/07 00:20:13 dyoung 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 1.108 2008/11/07 00:20:13 dyoung 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 SIOCINITIFADDR: 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 default: 487 error = ifioctl_common(ifp, cmd, data); 488 } 489 490 simple_unlock(&tp->tun_lock); 491 splx(s); 492 return (error); 493 } 494 495 /* 496 * tun_output - queue packets from higher level ready to put out. 497 */ 498 static int 499 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 500 struct rtentry *rt) 501 { 502 struct tun_softc *tp = ifp->if_softc; 503 int s; 504 int error; 505 #if defined(INET) || defined(INET6) 506 int mlen; 507 uint32_t *af; 508 #endif 509 ALTQ_DECL(struct altq_pktattr pktattr;) 510 511 s = splnet(); 512 simple_lock(&tp->tun_lock); 513 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 514 515 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 516 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 517 tp->tun_flags); 518 m_freem (m0); 519 error = EHOSTDOWN; 520 goto out; 521 } 522 523 /* 524 * if the queueing discipline needs packet classification, 525 * do it before prepending link headers. 526 */ 527 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 528 529 #if NBPFILTER > 0 530 if (ifp->if_bpf) 531 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0); 532 #endif 533 534 switch(dst->sa_family) { 535 #ifdef INET6 536 case AF_INET6: 537 #endif 538 #ifdef INET 539 case AF_INET: 540 #endif 541 #if defined(INET) || defined(INET6) 542 if (tp->tun_flags & TUN_PREPADDR) { 543 /* Simple link-layer header */ 544 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 545 if (m0 == NULL) { 546 IF_DROP(&ifp->if_snd); 547 error = ENOBUFS; 548 goto out; 549 } 550 bcopy(dst, mtod(m0, char *), dst->sa_len); 551 } 552 553 if (tp->tun_flags & TUN_IFHEAD) { 554 /* Prepend the address family */ 555 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 556 if (m0 == NULL) { 557 IF_DROP(&ifp->if_snd); 558 error = ENOBUFS; 559 goto out; 560 } 561 af = mtod(m0,uint32_t *); 562 *af = htonl(dst->sa_family); 563 } else { 564 #ifdef INET 565 if (dst->sa_family != AF_INET) 566 #endif 567 { 568 m_freem(m0); 569 error = EAFNOSUPPORT; 570 goto out; 571 } 572 } 573 /* FALLTHROUGH */ 574 case AF_UNSPEC: 575 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 576 if (error) { 577 ifp->if_collisions++; 578 error = EAFNOSUPPORT; 579 goto out; 580 } 581 mlen = m0->m_pkthdr.len; 582 ifp->if_opackets++; 583 ifp->if_obytes += mlen; 584 break; 585 #endif 586 default: 587 m_freem(m0); 588 error = EAFNOSUPPORT; 589 goto out; 590 } 591 592 if (tp->tun_flags & TUN_RWAIT) { 593 tp->tun_flags &= ~TUN_RWAIT; 594 wakeup((void *)tp); 595 } 596 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 597 softint_schedule(tp->tun_isih); 598 599 selnotify(&tp->tun_rsel, 0, 0); 600 out: 601 simple_unlock(&tp->tun_lock); 602 splx(s); 603 return (0); 604 } 605 606 static void 607 tun_i_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_IN, POLLIN|POLLRDNORM, 613 NULL); 614 } 615 616 static void 617 tun_o_softintr(void *cookie) 618 { 619 struct tun_softc *tp = cookie; 620 621 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 622 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 623 NULL); 624 } 625 626 /* 627 * the cdevsw interface is now pretty minimal. 628 */ 629 int 630 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 631 { 632 struct tun_softc *tp; 633 int s, error = 0; 634 635 s = splnet(); 636 tp = tun_find_unit(dev); 637 638 /* interface was "destroyed" already */ 639 if (tp == NULL) { 640 error = ENXIO; 641 goto out_nolock; 642 } 643 644 switch (cmd) { 645 case TUNSDEBUG: 646 tundebug = *(int *)data; 647 break; 648 649 case TUNGDEBUG: 650 *(int *)data = tundebug; 651 break; 652 653 case TUNSIFMODE: 654 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 655 case IFF_POINTOPOINT: 656 case IFF_BROADCAST: 657 if (tp->tun_if.if_flags & IFF_UP) { 658 error = EBUSY; 659 goto out; 660 } 661 tp->tun_if.if_flags &= 662 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 663 tp->tun_if.if_flags |= *(int *)data; 664 break; 665 default: 666 error = EINVAL; 667 goto out; 668 } 669 break; 670 671 case TUNSLMODE: 672 if (*(int *)data) { 673 tp->tun_flags |= TUN_PREPADDR; 674 tp->tun_flags &= ~TUN_IFHEAD; 675 } else 676 tp->tun_flags &= ~TUN_PREPADDR; 677 break; 678 679 case TUNSIFHEAD: 680 if (*(int *)data) { 681 tp->tun_flags |= TUN_IFHEAD; 682 tp->tun_flags &= ~TUN_PREPADDR; 683 } else 684 tp->tun_flags &= ~TUN_IFHEAD; 685 break; 686 687 case TUNGIFHEAD: 688 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 689 break; 690 691 case FIONBIO: 692 if (*(int *)data) 693 tp->tun_flags |= TUN_NBIO; 694 else 695 tp->tun_flags &= ~TUN_NBIO; 696 break; 697 698 case FIOASYNC: 699 if (*(int *)data) 700 tp->tun_flags |= TUN_ASYNC; 701 else 702 tp->tun_flags &= ~TUN_ASYNC; 703 break; 704 705 case FIONREAD: 706 if (tp->tun_if.if_snd.ifq_head) 707 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 708 else 709 *(int *)data = 0; 710 break; 711 712 case TIOCSPGRP: 713 case FIOSETOWN: 714 error = fsetown(&tp->tun_pgid, cmd, data); 715 break; 716 717 case TIOCGPGRP: 718 case FIOGETOWN: 719 error = fgetown(tp->tun_pgid, cmd, data); 720 break; 721 722 default: 723 error = ENOTTY; 724 } 725 726 out: 727 simple_unlock(&tp->tun_lock); 728 out_nolock: 729 splx(s); 730 return (error); 731 } 732 733 /* 734 * The cdevsw read interface - reads a packet at a time, or at 735 * least as much of a packet as can be read. 736 */ 737 int 738 tunread(dev_t dev, struct uio *uio, int ioflag) 739 { 740 struct tun_softc *tp; 741 struct ifnet *ifp; 742 struct mbuf *m, *m0; 743 int error = 0, len, s, index; 744 745 s = splnet(); 746 tp = tun_find_unit(dev); 747 748 /* interface was "destroyed" already */ 749 if (tp == NULL) { 750 error = ENXIO; 751 goto out_nolock; 752 } 753 754 index = tp->tun_if.if_index; 755 ifp = &tp->tun_if; 756 757 TUNDEBUG ("%s: read\n", ifp->if_xname); 758 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 759 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 760 error = EHOSTDOWN; 761 goto out; 762 } 763 764 tp->tun_flags &= ~TUN_RWAIT; 765 766 do { 767 IFQ_DEQUEUE(&ifp->if_snd, m0); 768 if (m0 == 0) { 769 if (tp->tun_flags & TUN_NBIO) { 770 error = EWOULDBLOCK; 771 goto out; 772 } 773 tp->tun_flags |= TUN_RWAIT; 774 if (ltsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 775 "tunread", 0, &tp->tun_lock) != 0) { 776 error = EINTR; 777 goto out_nolock; 778 } else { 779 /* 780 * Maybe the interface was destroyed while 781 * we were sleeping, so let's ensure that 782 * we're looking at the same (valid) tun 783 * interface before looping. 784 */ 785 tp = tun_find_unit(dev); 786 if (tp == NULL) { 787 error = ENXIO; 788 goto out_nolock; 789 } 790 if (tp->tun_if.if_index != index) { 791 error = ENXIO; 792 goto out; 793 } 794 } 795 } 796 } while (m0 == 0); 797 798 simple_unlock(&tp->tun_lock); 799 splx(s); 800 801 /* Copy the mbuf chain */ 802 while (m0 && uio->uio_resid > 0 && error == 0) { 803 len = min(uio->uio_resid, m0->m_len); 804 if (len != 0) 805 error = uiomove(mtod(m0, void *), len, uio); 806 MFREE(m0, m); 807 m0 = m; 808 } 809 810 if (m0) { 811 TUNDEBUG("Dropping mbuf\n"); 812 m_freem(m0); 813 } 814 if (error) 815 ifp->if_ierrors++; 816 817 return (error); 818 819 out: 820 simple_unlock(&tp->tun_lock); 821 out_nolock: 822 splx(s); 823 return (error); 824 } 825 826 /* 827 * the cdevsw write interface - an atomic write is a packet - or else! 828 */ 829 int 830 tunwrite(dev_t dev, struct uio *uio, int ioflag) 831 { 832 struct tun_softc *tp; 833 struct ifnet *ifp; 834 struct mbuf *top, **mp, *m; 835 struct ifqueue *ifq; 836 struct sockaddr dst; 837 int isr, error = 0, s, tlen, mlen; 838 uint32_t family; 839 840 s = splnet(); 841 tp = tun_find_unit(dev); 842 843 /* interface was "destroyed" already */ 844 if (tp == NULL) { 845 error = ENXIO; 846 goto out_nolock; 847 } 848 849 /* Unlock until we've got the data */ 850 simple_unlock(&tp->tun_lock); 851 splx(s); 852 853 ifp = &tp->tun_if; 854 855 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 856 857 if (tp->tun_flags & TUN_PREPADDR) { 858 if (uio->uio_resid < sizeof(dst)) { 859 error = EIO; 860 goto out0; 861 } 862 error = uiomove((void *)&dst, sizeof(dst), uio); 863 if (dst.sa_len > sizeof(dst)) { 864 /* Duh.. */ 865 char discard; 866 int n = dst.sa_len - sizeof(dst); 867 while (n--) 868 if ((error = uiomove(&discard, 1, uio)) != 0) { 869 goto out0; 870 } 871 } 872 } else if (tp->tun_flags & TUN_IFHEAD) { 873 if (uio->uio_resid < sizeof(family)){ 874 error = EIO; 875 goto out0; 876 } 877 error = uiomove((void *)&family, sizeof(family), uio); 878 dst.sa_family = ntohl(family); 879 } else { 880 #ifdef INET 881 dst.sa_family = AF_INET; 882 #endif 883 } 884 885 if (uio->uio_resid > TUNMTU) { 886 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 887 (unsigned long)uio->uio_resid); 888 error = EIO; 889 goto out0; 890 } 891 892 switch (dst.sa_family) { 893 #ifdef INET 894 case AF_INET: 895 ifq = &ipintrq; 896 isr = NETISR_IP; 897 break; 898 #endif 899 #ifdef INET6 900 case AF_INET6: 901 ifq = &ip6intrq; 902 isr = NETISR_IPV6; 903 break; 904 #endif 905 default: 906 error = EAFNOSUPPORT; 907 goto out0; 908 } 909 910 tlen = uio->uio_resid; 911 912 /* get a header mbuf */ 913 MGETHDR(m, M_DONTWAIT, MT_DATA); 914 if (m == NULL) { 915 error = ENOBUFS; 916 goto out0; 917 } 918 mlen = MHLEN; 919 920 top = NULL; 921 mp = ⊤ 922 while (error == 0 && uio->uio_resid > 0) { 923 m->m_len = min(mlen, uio->uio_resid); 924 error = uiomove(mtod(m, void *), m->m_len, uio); 925 *mp = m; 926 mp = &m->m_next; 927 if (error == 0 && uio->uio_resid > 0) { 928 MGET(m, M_DONTWAIT, MT_DATA); 929 if (m == NULL) { 930 error = ENOBUFS; 931 break; 932 } 933 mlen = MLEN; 934 } 935 } 936 if (error) { 937 if (top != NULL) 938 m_freem (top); 939 ifp->if_ierrors++; 940 goto out0; 941 } 942 943 top->m_pkthdr.len = tlen; 944 top->m_pkthdr.rcvif = ifp; 945 946 #if NBPFILTER > 0 947 if (ifp->if_bpf) 948 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 949 #endif 950 951 s = splnet(); 952 simple_lock(&tp->tun_lock); 953 if ((tp->tun_flags & TUN_INITED) == 0) { 954 /* Interface was destroyed */ 955 error = ENXIO; 956 goto out; 957 } 958 if (IF_QFULL(ifq)) { 959 IF_DROP(ifq); 960 ifp->if_collisions++; 961 m_freem(top); 962 error = ENOBUFS; 963 goto out; 964 } 965 966 IF_ENQUEUE(ifq, top); 967 ifp->if_ipackets++; 968 ifp->if_ibytes += tlen; 969 schednetisr(isr); 970 out: 971 simple_unlock(&tp->tun_lock); 972 out_nolock: 973 splx(s); 974 out0: 975 return (error); 976 } 977 978 #ifdef ALTQ 979 /* 980 * Start packet transmission on the interface. 981 * when the interface queue is rate-limited by ALTQ or TBR, 982 * if_start is needed to drain packets from the queue in order 983 * to notify readers when outgoing packets become ready. 984 * 985 * Should be called at splnet. 986 */ 987 static void 988 tunstart(struct ifnet *ifp) 989 { 990 struct tun_softc *tp = ifp->if_softc; 991 992 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 993 return; 994 995 simple_lock(&tp->tun_lock); 996 if (!IF_IS_EMPTY(&ifp->if_snd)) { 997 if (tp->tun_flags & TUN_RWAIT) { 998 tp->tun_flags &= ~TUN_RWAIT; 999 wakeup((void *)tp); 1000 } 1001 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 1002 softint_schedule(tp->tun_osih); 1003 1004 selnotify(&tp->tun_rsel, 0, 0); 1005 } 1006 simple_unlock(&tp->tun_lock); 1007 } 1008 #endif /* ALTQ */ 1009 /* 1010 * tunpoll - the poll interface, this is only useful on reads 1011 * really. The write detect always returns true, write never blocks 1012 * anyway, it either accepts the packet or drops it. 1013 */ 1014 int 1015 tunpoll(dev_t dev, int events, struct lwp *l) 1016 { 1017 struct tun_softc *tp; 1018 struct ifnet *ifp; 1019 int s, revents = 0; 1020 1021 s = splnet(); 1022 tp = tun_find_unit(dev); 1023 1024 /* interface was "destroyed" already */ 1025 if (tp == NULL) 1026 goto out_nolock; 1027 1028 ifp = &tp->tun_if; 1029 1030 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1031 1032 if (events & (POLLIN | POLLRDNORM)) { 1033 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1034 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1035 ifp->if_snd.ifq_len); 1036 revents |= events & (POLLIN | POLLRDNORM); 1037 } else { 1038 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1039 selrecord(l, &tp->tun_rsel); 1040 } 1041 } 1042 1043 if (events & (POLLOUT | POLLWRNORM)) 1044 revents |= events & (POLLOUT | POLLWRNORM); 1045 1046 simple_unlock(&tp->tun_lock); 1047 out_nolock: 1048 splx(s); 1049 return (revents); 1050 } 1051 1052 static void 1053 filt_tunrdetach(struct knote *kn) 1054 { 1055 struct tun_softc *tp = kn->kn_hook; 1056 int s; 1057 1058 s = splnet(); 1059 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1060 splx(s); 1061 } 1062 1063 static int 1064 filt_tunread(struct knote *kn, long hint) 1065 { 1066 struct tun_softc *tp = kn->kn_hook; 1067 struct ifnet *ifp = &tp->tun_if; 1068 struct mbuf *m; 1069 int s; 1070 1071 s = splnet(); 1072 IF_POLL(&ifp->if_snd, m); 1073 if (m == NULL) { 1074 splx(s); 1075 return (0); 1076 } 1077 1078 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1079 kn->kn_data += m->m_len; 1080 1081 splx(s); 1082 return (1); 1083 } 1084 1085 static const struct filterops tunread_filtops = 1086 { 1, NULL, filt_tunrdetach, filt_tunread }; 1087 1088 static const struct filterops tun_seltrue_filtops = 1089 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1090 1091 int 1092 tunkqfilter(dev_t dev, struct knote *kn) 1093 { 1094 struct tun_softc *tp; 1095 struct klist *klist; 1096 int rv = 0, s; 1097 1098 s = splnet(); 1099 tp = tun_find_unit(dev); 1100 if (tp == NULL) 1101 goto out_nolock; 1102 1103 switch (kn->kn_filter) { 1104 case EVFILT_READ: 1105 klist = &tp->tun_rsel.sel_klist; 1106 kn->kn_fop = &tunread_filtops; 1107 break; 1108 1109 case EVFILT_WRITE: 1110 klist = &tp->tun_rsel.sel_klist; 1111 kn->kn_fop = &tun_seltrue_filtops; 1112 break; 1113 1114 default: 1115 rv = EINVAL; 1116 goto out; 1117 } 1118 1119 kn->kn_hook = tp; 1120 1121 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1122 1123 out: 1124 simple_unlock(&tp->tun_lock); 1125 out_nolock: 1126 splx(s); 1127 return (rv); 1128 } 1129
Indexes created Wed Sep 24 02:09:48 GMT 2025