if_tun.c revision 1.100
1 /* $NetBSD: if_tun.c,v 1.100 2007/12/05 17:20:01 pooka 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 1.100 2007/12/05 17:20:01 pooka 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 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 #ifdef ALTQ 86 static void tunstart(struct ifnet *); 87 #endif 88 static struct tun_softc *tun_find_unit(dev_t); 89 static struct tun_softc *tun_find_zunit(int); 90 91 static dev_type_open(tunopen); 92 static dev_type_close(tunclose); 93 static dev_type_read(tunread); 94 static dev_type_write(tunwrite); 95 static dev_type_ioctl(tunioctl); 96 static dev_type_poll(tunpoll); 97 static dev_type_kqfilter(tunkqfilter); 98 99 const struct cdevsw tun_cdevsw = { 100 tunopen, tunclose, tunread, tunwrite, tunioctl, 101 nostop, notty, tunpoll, nommap, tunkqfilter, D_OTHER, 102 }; 103 104 void 105 tunattach(int unused) 106 { 107 108 simple_lock_init(&tun_softc_lock); 109 LIST_INIT(&tun_softc_list); 110 LIST_INIT(&tunz_softc_list); 111 if_clone_attach(&tun_cloner); 112 } 113 114 /* 115 * Find driver instance from dev_t. 116 * Call at splnet(). 117 * Returns with tp locked (if found). 118 */ 119 static struct tun_softc * 120 tun_find_unit(dev_t dev) 121 { 122 struct tun_softc *tp; 123 int unit = minor(dev); 124 125 simple_lock(&tun_softc_lock); 126 LIST_FOREACH(tp, &tun_softc_list, tun_list) 127 if (unit == tp->tun_unit) 128 break; 129 if (tp) 130 simple_lock(&tp->tun_lock); 131 simple_unlock(&tun_softc_lock); 132 133 return (tp); 134 } 135 136 /* 137 * Find zombie driver instance by unit number. 138 * Call at splnet(). 139 * Remove tp from list and return it unlocked (if found). 140 */ 141 static struct tun_softc * 142 tun_find_zunit(int unit) 143 { 144 struct tun_softc *tp; 145 146 simple_lock(&tun_softc_lock); 147 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 148 if (unit == tp->tun_unit) 149 break; 150 if (tp) 151 LIST_REMOVE(tp, tun_list); 152 simple_unlock(&tun_softc_lock); 153 #ifdef DIAGNOSTIC 154 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 155 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 156 #endif 157 158 return (tp); 159 } 160 161 static int 162 tun_clone_create(struct if_clone *ifc, int unit) 163 { 164 struct tun_softc *tp; 165 166 if ((tp = tun_find_zunit(unit)) == NULL) { 167 /* Allocate a new instance */ 168 tp = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 169 (void)memset(tp, 0, sizeof(struct tun_softc)); 170 171 tp->tun_unit = unit; 172 simple_lock_init(&tp->tun_lock); 173 } else { 174 /* Revive tunnel instance; clear ifp part */ 175 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 176 } 177 178 (void)snprintf(tp->tun_if.if_xname, sizeof(tp->tun_if.if_xname), 179 "%s%d", ifc->ifc_name, unit); 180 tunattach0(tp); 181 tp->tun_flags |= TUN_INITED; 182 183 simple_lock(&tun_softc_lock); 184 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 185 simple_unlock(&tun_softc_lock); 186 187 return (0); 188 } 189 190 static void 191 tunattach0(struct tun_softc *tp) 192 { 193 struct ifnet *ifp; 194 195 ifp = &tp->tun_if; 196 ifp->if_softc = tp; 197 ifp->if_mtu = TUNMTU; 198 ifp->if_ioctl = tun_ioctl; 199 ifp->if_output = tun_output; 200 #ifdef ALTQ 201 ifp->if_start = tunstart; 202 #endif 203 ifp->if_flags = IFF_POINTOPOINT; 204 ifp->if_type = IFT_TUNNEL; 205 ifp->if_snd.ifq_maxlen = ifqmaxlen; 206 ifp->if_collisions = 0; 207 ifp->if_ierrors = 0; 208 ifp->if_oerrors = 0; 209 ifp->if_ipackets = 0; 210 ifp->if_opackets = 0; 211 ifp->if_ibytes = 0; 212 ifp->if_obytes = 0; 213 ifp->if_dlt = DLT_NULL; 214 IFQ_SET_READY(&ifp->if_snd); 215 if_attach(ifp); 216 if_alloc_sadl(ifp); 217 #if NBPFILTER > 0 218 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 219 #endif 220 } 221 222 static int 223 tun_clone_destroy(struct ifnet *ifp) 224 { 225 struct tun_softc *tp = (void *)ifp; 226 int s, zombie = 0; 227 228 s = splnet(); 229 simple_lock(&tun_softc_lock); 230 simple_lock(&tp->tun_lock); 231 LIST_REMOVE(tp, tun_list); 232 if (tp->tun_flags & TUN_OPEN) { 233 /* Hang on to storage until last close */ 234 zombie = 1; 235 tp->tun_flags &= ~TUN_INITED; 236 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 237 } 238 simple_unlock(&tun_softc_lock); 239 240 IF_PURGE(&ifp->if_snd); 241 ifp->if_flags &= ~IFF_RUNNING; 242 243 if (tp->tun_flags & TUN_RWAIT) { 244 tp->tun_flags &= ~TUN_RWAIT; 245 wakeup((void *)tp); 246 } 247 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 248 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 249 250 selwakeup(&tp->tun_rsel); 251 252 simple_unlock(&tp->tun_lock); 253 splx(s); 254 255 #if NBPFILTER > 0 256 bpfdetach(ifp); 257 #endif 258 if_detach(ifp); 259 260 if (!zombie) 261 free(tp, M_DEVBUF); 262 263 return (0); 264 } 265 266 /* 267 * tunnel open - must be superuser & the device must be 268 * configured in 269 */ 270 static int 271 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 272 { 273 struct ifnet *ifp; 274 struct tun_softc *tp; 275 int s, error; 276 277 if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, 278 NULL)) != 0) 279 return (error); 280 281 s = splnet(); 282 tp = tun_find_unit(dev); 283 284 if (tp == NULL) { 285 (void)tun_clone_create(&tun_cloner, minor(dev)); 286 tp = tun_find_unit(dev); 287 if (tp == NULL) { 288 error = ENXIO; 289 goto out_nolock; 290 } 291 } 292 293 if (tp->tun_flags & TUN_OPEN) { 294 error = EBUSY; 295 goto out; 296 } 297 298 ifp = &tp->tun_if; 299 tp->tun_flags |= TUN_OPEN; 300 TUNDEBUG("%s: open\n", ifp->if_xname); 301 out: 302 simple_unlock(&tp->tun_lock); 303 out_nolock: 304 splx(s); 305 return (error); 306 } 307 308 /* 309 * tunclose - close the device - mark i/f down & delete 310 * routing info 311 */ 312 int 313 tunclose(dev_t dev, int flag, int mode, 314 struct lwp *l) 315 { 316 int s; 317 struct tun_softc *tp; 318 struct ifnet *ifp; 319 320 s = splnet(); 321 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 322 /* interface was "destroyed" before the close */ 323 free(tp, M_DEVBUF); 324 goto out_nolock; 325 } 326 327 if ((tp = tun_find_unit(dev)) == NULL) 328 goto out_nolock; 329 330 ifp = &tp->tun_if; 331 332 tp->tun_flags &= ~TUN_OPEN; 333 334 /* 335 * junk all pending output 336 */ 337 IFQ_PURGE(&ifp->if_snd); 338 339 if (ifp->if_flags & IFF_UP) { 340 if_down(ifp); 341 if (ifp->if_flags & IFF_RUNNING) { 342 /* find internet addresses and delete routes */ 343 struct ifaddr *ifa; 344 IFADDR_FOREACH(ifa, ifp) { 345 #if defined(INET) || defined(INET6) 346 if (ifa->ifa_addr->sa_family == AF_INET || 347 ifa->ifa_addr->sa_family == AF_INET6) { 348 rtinit(ifa, (int)RTM_DELETE, 349 tp->tun_flags & TUN_DSTADDR 350 ? RTF_HOST 351 : 0); 352 } 353 #endif 354 } 355 } 356 } 357 tp->tun_pgid = 0; 358 selnotify(&tp->tun_rsel, 0); 359 360 TUNDEBUG ("%s: closed\n", ifp->if_xname); 361 simple_unlock(&tp->tun_lock); 362 out_nolock: 363 splx(s); 364 return (0); 365 } 366 367 /* 368 * Call at splnet() with tp locked. 369 */ 370 static void 371 tuninit(struct tun_softc *tp) 372 { 373 struct ifnet *ifp = &tp->tun_if; 374 struct ifaddr *ifa; 375 376 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 377 378 ifp->if_flags |= IFF_UP | IFF_RUNNING; 379 380 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 381 IFADDR_FOREACH(ifa, ifp) { 382 #ifdef INET 383 if (ifa->ifa_addr->sa_family == AF_INET) { 384 struct sockaddr_in *sin; 385 386 sin = satosin(ifa->ifa_addr); 387 if (sin && sin->sin_addr.s_addr) 388 tp->tun_flags |= TUN_IASET; 389 390 if (ifp->if_flags & IFF_POINTOPOINT) { 391 sin = satosin(ifa->ifa_dstaddr); 392 if (sin && sin->sin_addr.s_addr) 393 tp->tun_flags |= TUN_DSTADDR; 394 } 395 } 396 #endif 397 #ifdef INET6 398 if (ifa->ifa_addr->sa_family == AF_INET6) { 399 struct sockaddr_in6 *sin; 400 401 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 402 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 403 tp->tun_flags |= TUN_IASET; 404 405 if (ifp->if_flags & IFF_POINTOPOINT) { 406 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 407 if (sin && 408 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 409 tp->tun_flags |= TUN_DSTADDR; 410 } else 411 tp->tun_flags &= ~TUN_DSTADDR; 412 } 413 #endif /* INET6 */ 414 } 415 416 return; 417 } 418 419 /* 420 * Process an ioctl request. 421 */ 422 static int 423 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 424 { 425 int error = 0, s; 426 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 427 428 s = splnet(); 429 simple_lock(&tp->tun_lock); 430 431 switch (cmd) { 432 case SIOCSIFADDR: 433 tuninit(tp); 434 TUNDEBUG("%s: address set\n", ifp->if_xname); 435 break; 436 case SIOCSIFDSTADDR: 437 tuninit(tp); 438 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 439 break; 440 case SIOCSIFBRDADDR: 441 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 442 break; 443 case SIOCSIFMTU: { 444 struct ifreq *ifr = (struct ifreq *) data; 445 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 446 error = EINVAL; 447 break; 448 } 449 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 450 ifp->if_mtu = ifr->ifr_mtu; 451 break; 452 } 453 case SIOCADDMULTI: 454 case SIOCDELMULTI: { 455 struct ifreq *ifr = (struct ifreq *) data; 456 if (ifr == 0) { 457 error = EAFNOSUPPORT; /* XXX */ 458 break; 459 } 460 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 461 #ifdef INET 462 case AF_INET: 463 break; 464 #endif 465 #ifdef INET6 466 case AF_INET6: 467 break; 468 #endif 469 default: 470 error = EAFNOSUPPORT; 471 break; 472 } 473 break; 474 } 475 case SIOCSIFFLAGS: 476 break; 477 default: 478 error = EINVAL; 479 } 480 481 simple_unlock(&tp->tun_lock); 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 simple_lock(&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 m_freem (m0); 510 error = EHOSTDOWN; 511 goto out; 512 } 513 514 /* 515 * if the queueing discipline needs packet classification, 516 * do it before prepending link headers. 517 */ 518 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 519 520 #if NBPFILTER > 0 521 if (ifp->if_bpf) 522 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0); 523 #endif 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 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 589 NULL); 590 591 selnotify(&tp->tun_rsel, 0); 592 out: 593 simple_unlock(&tp->tun_lock); 594 splx(s); 595 return (0); 596 } 597 598 /* 599 * the cdevsw interface is now pretty minimal. 600 */ 601 int 602 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 603 { 604 struct tun_softc *tp; 605 int s, error = 0; 606 607 s = splnet(); 608 tp = tun_find_unit(dev); 609 610 /* interface was "destroyed" already */ 611 if (tp == NULL) { 612 error = ENXIO; 613 goto out_nolock; 614 } 615 616 switch (cmd) { 617 case TUNSDEBUG: 618 tundebug = *(int *)data; 619 break; 620 621 case TUNGDEBUG: 622 *(int *)data = tundebug; 623 break; 624 625 case TUNSIFMODE: 626 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 627 case IFF_POINTOPOINT: 628 case IFF_BROADCAST: 629 if (tp->tun_if.if_flags & IFF_UP) { 630 error = EBUSY; 631 goto out; 632 } 633 tp->tun_if.if_flags &= 634 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 635 tp->tun_if.if_flags |= *(int *)data; 636 break; 637 default: 638 error = EINVAL; 639 goto out; 640 } 641 break; 642 643 case TUNSLMODE: 644 if (*(int *)data) { 645 tp->tun_flags |= TUN_PREPADDR; 646 tp->tun_flags &= ~TUN_IFHEAD; 647 } else 648 tp->tun_flags &= ~TUN_PREPADDR; 649 break; 650 651 case TUNSIFHEAD: 652 if (*(int *)data) { 653 tp->tun_flags |= TUN_IFHEAD; 654 tp->tun_flags &= ~TUN_PREPADDR; 655 } else 656 tp->tun_flags &= ~TUN_IFHEAD; 657 break; 658 659 case TUNGIFHEAD: 660 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 661 break; 662 663 case FIONBIO: 664 if (*(int *)data) 665 tp->tun_flags |= TUN_NBIO; 666 else 667 tp->tun_flags &= ~TUN_NBIO; 668 break; 669 670 case FIOASYNC: 671 if (*(int *)data) 672 tp->tun_flags |= TUN_ASYNC; 673 else 674 tp->tun_flags &= ~TUN_ASYNC; 675 break; 676 677 case FIONREAD: 678 if (tp->tun_if.if_snd.ifq_head) 679 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 680 else 681 *(int *)data = 0; 682 break; 683 684 case TIOCSPGRP: 685 case FIOSETOWN: 686 error = fsetown(l->l_proc, &tp->tun_pgid, cmd, data); 687 break; 688 689 case TIOCGPGRP: 690 case FIOGETOWN: 691 error = fgetown(l->l_proc, tp->tun_pgid, cmd, data); 692 break; 693 694 default: 695 error = ENOTTY; 696 } 697 698 out: 699 simple_unlock(&tp->tun_lock); 700 out_nolock: 701 splx(s); 702 return (error); 703 } 704 705 /* 706 * The cdevsw read interface - reads a packet at a time, or at 707 * least as much of a packet as can be read. 708 */ 709 int 710 tunread(dev_t dev, struct uio *uio, int ioflag) 711 { 712 struct tun_softc *tp; 713 struct ifnet *ifp; 714 struct mbuf *m, *m0; 715 int error = 0, len, s, index; 716 717 s = splnet(); 718 tp = tun_find_unit(dev); 719 720 /* interface was "destroyed" already */ 721 if (tp == NULL) { 722 error = ENXIO; 723 goto out_nolock; 724 } 725 726 index = tp->tun_if.if_index; 727 ifp = &tp->tun_if; 728 729 TUNDEBUG ("%s: read\n", ifp->if_xname); 730 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 731 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 732 error = EHOSTDOWN; 733 goto out; 734 } 735 736 tp->tun_flags &= ~TUN_RWAIT; 737 738 do { 739 IFQ_DEQUEUE(&ifp->if_snd, m0); 740 if (m0 == 0) { 741 if (tp->tun_flags & TUN_NBIO) { 742 error = EWOULDBLOCK; 743 goto out; 744 } 745 tp->tun_flags |= TUN_RWAIT; 746 if (ltsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 747 "tunread", 0, &tp->tun_lock) != 0) { 748 error = EINTR; 749 goto out_nolock; 750 } else { 751 /* 752 * Maybe the interface was destroyed while 753 * we were sleeping, so let's ensure that 754 * we're looking at the same (valid) tun 755 * interface before looping. 756 */ 757 tp = tun_find_unit(dev); 758 if (tp == NULL) { 759 error = ENXIO; 760 goto out_nolock; 761 } 762 if (tp->tun_if.if_index != index) { 763 error = ENXIO; 764 goto out; 765 } 766 } 767 } 768 } while (m0 == 0); 769 770 simple_unlock(&tp->tun_lock); 771 splx(s); 772 773 /* Copy the mbuf chain */ 774 while (m0 && uio->uio_resid > 0 && error == 0) { 775 len = min(uio->uio_resid, m0->m_len); 776 if (len != 0) 777 error = uiomove(mtod(m0, void *), len, uio); 778 MFREE(m0, m); 779 m0 = m; 780 } 781 782 if (m0) { 783 TUNDEBUG("Dropping mbuf\n"); 784 m_freem(m0); 785 } 786 if (error) 787 ifp->if_ierrors++; 788 789 return (error); 790 791 out: 792 simple_unlock(&tp->tun_lock); 793 out_nolock: 794 splx(s); 795 return (error); 796 } 797 798 /* 799 * the cdevsw write interface - an atomic write is a packet - or else! 800 */ 801 int 802 tunwrite(dev_t dev, struct uio *uio, int ioflag) 803 { 804 struct tun_softc *tp; 805 struct ifnet *ifp; 806 struct mbuf *top, **mp, *m; 807 struct ifqueue *ifq; 808 struct sockaddr dst; 809 int isr, error = 0, s, tlen, mlen; 810 uint32_t family; 811 812 s = splnet(); 813 tp = tun_find_unit(dev); 814 815 /* interface was "destroyed" already */ 816 if (tp == NULL) { 817 error = ENXIO; 818 goto out_nolock; 819 } 820 821 /* Unlock until we've got the data */ 822 simple_unlock(&tp->tun_lock); 823 splx(s); 824 825 ifp = &tp->tun_if; 826 827 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 828 829 if (tp->tun_flags & TUN_PREPADDR) { 830 if (uio->uio_resid < sizeof(dst)) { 831 error = EIO; 832 goto out0; 833 } 834 error = uiomove((void *)&dst, sizeof(dst), uio); 835 if (dst.sa_len > sizeof(dst)) { 836 /* Duh.. */ 837 char discard; 838 int n = dst.sa_len - sizeof(dst); 839 while (n--) 840 if ((error = uiomove(&discard, 1, uio)) != 0) { 841 goto out0; 842 } 843 } 844 } else if (tp->tun_flags & TUN_IFHEAD) { 845 if (uio->uio_resid < sizeof(family)){ 846 error = EIO; 847 goto out0; 848 } 849 error = uiomove((void *)&family, sizeof(family), uio); 850 dst.sa_family = ntohl(family); 851 } else { 852 #ifdef INET 853 dst.sa_family = AF_INET; 854 #endif 855 } 856 857 if (uio->uio_resid > TUNMTU) { 858 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 859 (unsigned long)uio->uio_resid); 860 error = EIO; 861 goto out0; 862 } 863 864 switch (dst.sa_family) { 865 #ifdef INET 866 case AF_INET: 867 ifq = &ipintrq; 868 isr = NETISR_IP; 869 break; 870 #endif 871 #ifdef INET6 872 case AF_INET6: 873 ifq = &ip6intrq; 874 isr = NETISR_IPV6; 875 break; 876 #endif 877 default: 878 error = EAFNOSUPPORT; 879 goto out0; 880 } 881 882 tlen = uio->uio_resid; 883 884 /* get a header mbuf */ 885 MGETHDR(m, M_DONTWAIT, MT_DATA); 886 if (m == NULL) { 887 error = ENOBUFS; 888 goto out0; 889 } 890 mlen = MHLEN; 891 892 top = NULL; 893 mp = ⊤ 894 while (error == 0 && uio->uio_resid > 0) { 895 m->m_len = min(mlen, uio->uio_resid); 896 error = uiomove(mtod(m, void *), m->m_len, uio); 897 *mp = m; 898 mp = &m->m_next; 899 if (error == 0 && uio->uio_resid > 0) { 900 MGET(m, M_DONTWAIT, MT_DATA); 901 if (m == NULL) { 902 error = ENOBUFS; 903 break; 904 } 905 mlen = MLEN; 906 } 907 } 908 if (error) { 909 if (top != NULL) 910 m_freem (top); 911 ifp->if_ierrors++; 912 goto out0; 913 } 914 915 top->m_pkthdr.len = tlen; 916 top->m_pkthdr.rcvif = ifp; 917 918 #if NBPFILTER > 0 919 if (ifp->if_bpf) 920 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 921 #endif 922 923 s = splnet(); 924 simple_lock(&tp->tun_lock); 925 if ((tp->tun_flags & TUN_INITED) == 0) { 926 /* Interface was destroyed */ 927 error = ENXIO; 928 goto out; 929 } 930 if (IF_QFULL(ifq)) { 931 IF_DROP(ifq); 932 ifp->if_collisions++; 933 m_freem(top); 934 error = ENOBUFS; 935 goto out; 936 } 937 938 IF_ENQUEUE(ifq, top); 939 ifp->if_ipackets++; 940 ifp->if_ibytes += tlen; 941 schednetisr(isr); 942 out: 943 simple_unlock(&tp->tun_lock); 944 out_nolock: 945 splx(s); 946 out0: 947 return (error); 948 } 949 950 #ifdef ALTQ 951 /* 952 * Start packet transmission on the interface. 953 * when the interface queue is rate-limited by ALTQ or TBR, 954 * if_start is needed to drain packets from the queue in order 955 * to notify readers when outgoing packets become ready. 956 * 957 * Should be called at splnet. 958 */ 959 static void 960 tunstart(struct ifnet *ifp) 961 { 962 struct tun_softc *tp = ifp->if_softc; 963 964 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 965 return; 966 967 simple_lock(&tp->tun_lock); 968 if (!IF_IS_EMPTY(&ifp->if_snd)) { 969 if (tp->tun_flags & TUN_RWAIT) { 970 tp->tun_flags &= ~TUN_RWAIT; 971 wakeup((void *)tp); 972 } 973 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 974 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 975 POLLOUT|POLLWRNORM, NULL); 976 977 selwakeup(&tp->tun_rsel); 978 } 979 simple_unlock(&tp->tun_lock); 980 } 981 #endif /* ALTQ */ 982 /* 983 * tunpoll - the poll interface, this is only useful on reads 984 * really. The write detect always returns true, write never blocks 985 * anyway, it either accepts the packet or drops it. 986 */ 987 int 988 tunpoll(dev_t dev, int events, struct lwp *l) 989 { 990 struct tun_softc *tp; 991 struct ifnet *ifp; 992 int s, revents = 0; 993 994 s = splnet(); 995 tp = tun_find_unit(dev); 996 997 /* interface was "destroyed" already */ 998 if (tp == NULL) 999 goto out_nolock; 1000 1001 ifp = &tp->tun_if; 1002 1003 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1004 1005 if (events & (POLLIN | POLLRDNORM)) { 1006 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1007 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1008 ifp->if_snd.ifq_len); 1009 revents |= events & (POLLIN | POLLRDNORM); 1010 } else { 1011 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1012 selrecord(l, &tp->tun_rsel); 1013 } 1014 } 1015 1016 if (events & (POLLOUT | POLLWRNORM)) 1017 revents |= events & (POLLOUT | POLLWRNORM); 1018 1019 simple_unlock(&tp->tun_lock); 1020 out_nolock: 1021 splx(s); 1022 return (revents); 1023 } 1024 1025 static void 1026 filt_tunrdetach(struct knote *kn) 1027 { 1028 struct tun_softc *tp = kn->kn_hook; 1029 int s; 1030 1031 s = splnet(); 1032 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1033 splx(s); 1034 } 1035 1036 static int 1037 filt_tunread(struct knote *kn, long hint) 1038 { 1039 struct tun_softc *tp = kn->kn_hook; 1040 struct ifnet *ifp = &tp->tun_if; 1041 struct mbuf *m; 1042 int s; 1043 1044 s = splnet(); 1045 IF_POLL(&ifp->if_snd, m); 1046 if (m == NULL) { 1047 splx(s); 1048 return (0); 1049 } 1050 1051 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1052 kn->kn_data += m->m_len; 1053 1054 splx(s); 1055 return (1); 1056 } 1057 1058 static const struct filterops tunread_filtops = 1059 { 1, NULL, filt_tunrdetach, filt_tunread }; 1060 1061 static const struct filterops tun_seltrue_filtops = 1062 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1063 1064 int 1065 tunkqfilter(dev_t dev, struct knote *kn) 1066 { 1067 struct tun_softc *tp; 1068 struct klist *klist; 1069 int rv = 0, s; 1070 1071 s = splnet(); 1072 tp = tun_find_unit(dev); 1073 if (tp == NULL) 1074 goto out_nolock; 1075 1076 switch (kn->kn_filter) { 1077 case EVFILT_READ: 1078 klist = &tp->tun_rsel.sel_klist; 1079 kn->kn_fop = &tunread_filtops; 1080 break; 1081 1082 case EVFILT_WRITE: 1083 klist = &tp->tun_rsel.sel_klist; 1084 kn->kn_fop = &tun_seltrue_filtops; 1085 break; 1086 1087 default: 1088 rv = EINVAL; 1089 goto out; 1090 } 1091 1092 kn->kn_hook = tp; 1093 1094 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1095 1096 out: 1097 simple_unlock(&tp->tun_lock); 1098 out_nolock: 1099 splx(s); 1100 return (rv); 1101 } 1102
Indexes created Tue Sep 23 07:09:52 GMT 2025