if_tun.c revision 1.92
1 /* $NetBSD: if_tun.c,v 1.92 2006/09/07 02:40:33 dogcow 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 1.92 2006/09/07 02:40:33 dogcow 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 <machine/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, caddr_t); 75 static int tun_output(struct ifnet *, struct mbuf *, struct sockaddr *, 76 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((caddr_t)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 &l->l_acflag)) != 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, struct lwp *l) 314 { 315 int s; 316 struct tun_softc *tp; 317 struct ifnet *ifp; 318 319 s = splnet(); 320 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 321 /* interface was "destroyed" before the close */ 322 free(tp, M_DEVBUF); 323 goto out_nolock; 324 } 325 326 if ((tp = tun_find_unit(dev)) == NULL) 327 goto out_nolock; 328 329 ifp = &tp->tun_if; 330 331 tp->tun_flags &= ~TUN_OPEN; 332 333 /* 334 * junk all pending output 335 */ 336 IFQ_PURGE(&ifp->if_snd); 337 338 if (ifp->if_flags & IFF_UP) { 339 if_down(ifp); 340 if (ifp->if_flags & IFF_RUNNING) { 341 /* find internet addresses and delete routes */ 342 struct ifaddr *ifa; 343 IFADDR_FOREACH(ifa, ifp) { 344 #if defined(INET) || defined(INET6) 345 if (ifa->ifa_addr->sa_family == AF_INET || 346 ifa->ifa_addr->sa_family == AF_INET6) { 347 rtinit(ifa, (int)RTM_DELETE, 348 tp->tun_flags & TUN_DSTADDR 349 ? RTF_HOST 350 : 0); 351 } 352 #endif 353 } 354 } 355 } 356 tp->tun_pgid = 0; 357 selnotify(&tp->tun_rsel, 0); 358 359 TUNDEBUG ("%s: closed\n", ifp->if_xname); 360 simple_unlock(&tp->tun_lock); 361 out_nolock: 362 splx(s); 363 return (0); 364 } 365 366 /* 367 * Call at splnet() with tp locked. 368 */ 369 static void 370 tuninit(struct tun_softc *tp) 371 { 372 struct ifnet *ifp = &tp->tun_if; 373 struct ifaddr *ifa; 374 375 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 376 377 ifp->if_flags |= IFF_UP | IFF_RUNNING; 378 379 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 380 IFADDR_FOREACH(ifa, ifp) { 381 #ifdef INET 382 if (ifa->ifa_addr->sa_family == AF_INET) { 383 struct sockaddr_in *sin; 384 385 sin = satosin(ifa->ifa_addr); 386 if (sin && sin->sin_addr.s_addr) 387 tp->tun_flags |= TUN_IASET; 388 389 if (ifp->if_flags & IFF_POINTOPOINT) { 390 sin = satosin(ifa->ifa_dstaddr); 391 if (sin && sin->sin_addr.s_addr) 392 tp->tun_flags |= TUN_DSTADDR; 393 } 394 } 395 #endif 396 #ifdef INET6 397 if (ifa->ifa_addr->sa_family == AF_INET6) { 398 struct sockaddr_in6 *sin; 399 400 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 401 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 402 tp->tun_flags |= TUN_IASET; 403 404 if (ifp->if_flags & IFF_POINTOPOINT) { 405 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 406 if (sin && 407 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 408 tp->tun_flags |= TUN_DSTADDR; 409 } else 410 tp->tun_flags &= ~TUN_DSTADDR; 411 } 412 #endif /* INET6 */ 413 } 414 415 return; 416 } 417 418 /* 419 * Process an ioctl request. 420 */ 421 static int 422 tun_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 423 { 424 int error = 0, s; 425 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 426 427 s = splnet(); 428 simple_lock(&tp->tun_lock); 429 430 switch (cmd) { 431 case SIOCSIFADDR: 432 tuninit(tp); 433 TUNDEBUG("%s: address set\n", ifp->if_xname); 434 break; 435 case SIOCSIFDSTADDR: 436 tuninit(tp); 437 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 438 break; 439 case SIOCSIFBRDADDR: 440 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 441 break; 442 case SIOCSIFMTU: { 443 struct ifreq *ifr = (struct ifreq *) data; 444 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 445 error = EINVAL; 446 break; 447 } 448 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 449 ifp->if_mtu = ifr->ifr_mtu; 450 break; 451 } 452 case SIOCADDMULTI: 453 case SIOCDELMULTI: { 454 struct ifreq *ifr = (struct ifreq *) data; 455 if (ifr == 0) { 456 error = EAFNOSUPPORT; /* XXX */ 457 break; 458 } 459 switch (ifr->ifr_addr.sa_family) { 460 #ifdef INET 461 case AF_INET: 462 break; 463 #endif 464 #ifdef INET6 465 case AF_INET6: 466 break; 467 #endif 468 default: 469 error = EAFNOSUPPORT; 470 break; 471 } 472 break; 473 } 474 case SIOCSIFFLAGS: 475 break; 476 default: 477 error = EINVAL; 478 } 479 480 simple_unlock(&tp->tun_lock); 481 splx(s); 482 return (error); 483 } 484 485 /* 486 * tun_output - queue packets from higher level ready to put out. 487 */ 488 static int 489 tun_output(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 490 struct rtentry *rt) 491 { 492 struct tun_softc *tp = ifp->if_softc; 493 int s; 494 int error; 495 #if defined(INET) || defined(INET6) 496 int mlen; 497 uint32_t *af; 498 #endif 499 ALTQ_DECL(struct altq_pktattr pktattr;) 500 501 s = splnet(); 502 simple_lock(&tp->tun_lock); 503 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 504 505 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 506 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 507 tp->tun_flags); 508 m_freem (m0); 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 #if NBPFILTER > 0 520 if (ifp->if_bpf) 521 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0); 522 #endif 523 524 switch(dst->sa_family) { 525 #ifdef INET6 526 case AF_INET6: 527 #endif 528 #ifdef INET 529 case AF_INET: 530 #endif 531 #if defined(INET) || defined(INET6) 532 if (tp->tun_flags & TUN_PREPADDR) { 533 /* Simple link-layer header */ 534 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 535 if (m0 == NULL) { 536 IF_DROP(&ifp->if_snd); 537 error = ENOBUFS; 538 goto out; 539 } 540 bcopy(dst, mtod(m0, char *), dst->sa_len); 541 } 542 543 if (tp->tun_flags & TUN_IFHEAD) { 544 /* Prepend the address family */ 545 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 546 if (m0 == NULL) { 547 IF_DROP(&ifp->if_snd); 548 error = ENOBUFS; 549 goto out; 550 } 551 af = mtod(m0,uint32_t *); 552 *af = htonl(dst->sa_family); 553 } else { 554 #ifdef INET 555 if (dst->sa_family != AF_INET) 556 #endif 557 { 558 m_freem(m0); 559 error = EAFNOSUPPORT; 560 goto out; 561 } 562 } 563 /* FALLTHROUGH */ 564 case AF_UNSPEC: 565 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 566 if (error) { 567 ifp->if_collisions++; 568 error = EAFNOSUPPORT; 569 goto out; 570 } 571 mlen = m0->m_pkthdr.len; 572 ifp->if_opackets++; 573 ifp->if_obytes += mlen; 574 break; 575 #endif 576 default: 577 m_freem(m0); 578 error = EAFNOSUPPORT; 579 goto out; 580 } 581 582 if (tp->tun_flags & TUN_RWAIT) { 583 tp->tun_flags &= ~TUN_RWAIT; 584 wakeup((caddr_t)tp); 585 } 586 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 587 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 588 NULL); 589 590 selnotify(&tp->tun_rsel, 0); 591 out: 592 simple_unlock(&tp->tun_lock); 593 splx(s); 594 return (0); 595 } 596 597 /* 598 * the cdevsw interface is now pretty minimal. 599 */ 600 int 601 tunioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l) 602 { 603 struct tun_softc *tp; 604 int s, error = 0; 605 606 s = splnet(); 607 tp = tun_find_unit(dev); 608 609 /* interface was "destroyed" already */ 610 if (tp == NULL) { 611 error = ENXIO; 612 goto out_nolock; 613 } 614 615 switch (cmd) { 616 case TUNSDEBUG: 617 tundebug = *(int *)data; 618 break; 619 620 case TUNGDEBUG: 621 *(int *)data = tundebug; 622 break; 623 624 case TUNSIFMODE: 625 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 626 case IFF_POINTOPOINT: 627 case IFF_BROADCAST: 628 if (tp->tun_if.if_flags & IFF_UP) { 629 error = EBUSY; 630 goto out; 631 } 632 tp->tun_if.if_flags &= 633 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 634 tp->tun_if.if_flags |= *(int *)data; 635 break; 636 default: 637 error = EINVAL; 638 goto out; 639 } 640 break; 641 642 case TUNSLMODE: 643 if (*(int *)data) { 644 tp->tun_flags |= TUN_PREPADDR; 645 tp->tun_flags &= ~TUN_IFHEAD; 646 } else 647 tp->tun_flags &= ~TUN_PREPADDR; 648 break; 649 650 case TUNSIFHEAD: 651 if (*(int *)data) { 652 tp->tun_flags |= TUN_IFHEAD; 653 tp->tun_flags &= ~TUN_PREPADDR; 654 } else 655 tp->tun_flags &= ~TUN_IFHEAD; 656 break; 657 658 case TUNGIFHEAD: 659 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 660 break; 661 662 case FIONBIO: 663 if (*(int *)data) 664 tp->tun_flags |= TUN_NBIO; 665 else 666 tp->tun_flags &= ~TUN_NBIO; 667 break; 668 669 case FIOASYNC: 670 if (*(int *)data) 671 tp->tun_flags |= TUN_ASYNC; 672 else 673 tp->tun_flags &= ~TUN_ASYNC; 674 break; 675 676 case FIONREAD: 677 if (tp->tun_if.if_snd.ifq_head) 678 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 679 else 680 *(int *)data = 0; 681 break; 682 683 case TIOCSPGRP: 684 case FIOSETOWN: 685 error = fsetown(l->l_proc, &tp->tun_pgid, cmd, data); 686 break; 687 688 case TIOCGPGRP: 689 case FIOGETOWN: 690 error = fgetown(l->l_proc, tp->tun_pgid, cmd, data); 691 break; 692 693 default: 694 error = ENOTTY; 695 } 696 697 out: 698 simple_unlock(&tp->tun_lock); 699 out_nolock: 700 splx(s); 701 return (error); 702 } 703 704 /* 705 * The cdevsw read interface - reads a packet at a time, or at 706 * least as much of a packet as can be read. 707 */ 708 int 709 tunread(dev_t dev, struct uio *uio, int ioflag) 710 { 711 struct tun_softc *tp; 712 struct ifnet *ifp; 713 struct mbuf *m, *m0; 714 int error = 0, len, s, index; 715 716 s = splnet(); 717 tp = tun_find_unit(dev); 718 719 /* interface was "destroyed" already */ 720 if (tp == NULL) { 721 error = ENXIO; 722 goto out_nolock; 723 } 724 725 index = tp->tun_if.if_index; 726 ifp = &tp->tun_if; 727 728 TUNDEBUG ("%s: read\n", ifp->if_xname); 729 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 730 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 731 error = EHOSTDOWN; 732 goto out; 733 } 734 735 tp->tun_flags &= ~TUN_RWAIT; 736 737 do { 738 IFQ_DEQUEUE(&ifp->if_snd, m0); 739 if (m0 == 0) { 740 if (tp->tun_flags & TUN_NBIO) { 741 error = EWOULDBLOCK; 742 goto out; 743 } 744 tp->tun_flags |= TUN_RWAIT; 745 if (ltsleep((caddr_t)tp, PZERO|PCATCH|PNORELOCK, 746 "tunread", 0, &tp->tun_lock) != 0) { 747 error = EINTR; 748 goto out_nolock; 749 } else { 750 /* 751 * Maybe the interface was destroyed while 752 * we were sleeping, so let's ensure that 753 * we're looking at the same (valid) tun 754 * interface before looping. 755 */ 756 tp = tun_find_unit(dev); 757 if (tp == NULL) { 758 error = ENXIO; 759 goto out_nolock; 760 } 761 if (tp->tun_if.if_index != index) { 762 error = ENXIO; 763 goto out; 764 } 765 } 766 } 767 } while (m0 == 0); 768 769 simple_unlock(&tp->tun_lock); 770 splx(s); 771 772 /* Copy the mbuf chain */ 773 while (m0 && uio->uio_resid > 0 && error == 0) { 774 len = min(uio->uio_resid, m0->m_len); 775 if (len != 0) 776 error = uiomove(mtod(m0, caddr_t), len, uio); 777 MFREE(m0, m); 778 m0 = m; 779 } 780 781 if (m0) { 782 TUNDEBUG("Dropping mbuf\n"); 783 m_freem(m0); 784 } 785 if (error) 786 ifp->if_ierrors++; 787 788 return (error); 789 790 out: 791 simple_unlock(&tp->tun_lock); 792 out_nolock: 793 splx(s); 794 return (error); 795 } 796 797 /* 798 * the cdevsw write interface - an atomic write is a packet - or else! 799 */ 800 int 801 tunwrite(dev_t dev, struct uio *uio, int ioflag) 802 { 803 struct tun_softc *tp; 804 struct ifnet *ifp; 805 struct mbuf *top, **mp, *m; 806 struct ifqueue *ifq; 807 struct sockaddr dst; 808 int isr, error = 0, s, tlen, mlen; 809 uint32_t family; 810 811 s = splnet(); 812 tp = tun_find_unit(dev); 813 814 /* interface was "destroyed" already */ 815 if (tp == NULL) { 816 error = ENXIO; 817 goto out_nolock; 818 } 819 820 /* Unlock until we've got the data */ 821 simple_unlock(&tp->tun_lock); 822 splx(s); 823 824 ifp = &tp->tun_if; 825 826 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 827 828 if (tp->tun_flags & TUN_PREPADDR) { 829 if (uio->uio_resid < sizeof(dst)) { 830 error = EIO; 831 goto out0; 832 } 833 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 834 if (dst.sa_len > sizeof(dst)) { 835 /* Duh.. */ 836 char discard; 837 int n = dst.sa_len - sizeof(dst); 838 while (n--) 839 if ((error = uiomove(&discard, 1, uio)) != 0) { 840 goto out0; 841 } 842 } 843 } else if (tp->tun_flags & TUN_IFHEAD) { 844 if (uio->uio_resid < sizeof(family)){ 845 error = EIO; 846 goto out0; 847 } 848 error = uiomove((caddr_t)&family, sizeof(family), uio); 849 dst.sa_family = ntohl(family); 850 } else { 851 #ifdef INET 852 dst.sa_family = AF_INET; 853 #endif 854 } 855 856 if (uio->uio_resid > TUNMTU) { 857 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 858 (unsigned long)uio->uio_resid); 859 error = EIO; 860 goto out0; 861 } 862 863 switch (dst.sa_family) { 864 #ifdef INET 865 case AF_INET: 866 ifq = &ipintrq; 867 isr = NETISR_IP; 868 break; 869 #endif 870 #ifdef INET6 871 case AF_INET6: 872 ifq = &ip6intrq; 873 isr = NETISR_IPV6; 874 break; 875 #endif 876 default: 877 error = EAFNOSUPPORT; 878 goto out0; 879 } 880 881 tlen = uio->uio_resid; 882 883 /* get a header mbuf */ 884 MGETHDR(m, M_DONTWAIT, MT_DATA); 885 if (m == NULL) { 886 error = ENOBUFS; 887 goto out0; 888 } 889 mlen = MHLEN; 890 891 top = NULL; 892 mp = ⊤ 893 while (error == 0 && uio->uio_resid > 0) { 894 m->m_len = min(mlen, uio->uio_resid); 895 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 896 *mp = m; 897 mp = &m->m_next; 898 if (error == 0 && uio->uio_resid > 0) { 899 MGET(m, M_DONTWAIT, MT_DATA); 900 if (m == NULL) { 901 error = ENOBUFS; 902 break; 903 } 904 mlen = MLEN; 905 } 906 } 907 if (error) { 908 if (top != NULL) 909 m_freem (top); 910 ifp->if_ierrors++; 911 goto out0; 912 } 913 914 top->m_pkthdr.len = tlen; 915 top->m_pkthdr.rcvif = ifp; 916 917 #if NBPFILTER > 0 918 if (ifp->if_bpf) 919 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 920 #endif 921 922 s = splnet(); 923 simple_lock(&tp->tun_lock); 924 if ((tp->tun_flags & TUN_INITED) == 0) { 925 /* Interface was destroyed */ 926 error = ENXIO; 927 goto out; 928 } 929 if (IF_QFULL(ifq)) { 930 IF_DROP(ifq); 931 ifp->if_collisions++; 932 m_freem(top); 933 error = ENOBUFS; 934 goto out; 935 } 936 937 IF_ENQUEUE(ifq, top); 938 ifp->if_ipackets++; 939 ifp->if_ibytes += tlen; 940 schednetisr(isr); 941 out: 942 simple_unlock(&tp->tun_lock); 943 out_nolock: 944 splx(s); 945 out0: 946 return (error); 947 } 948 949 #ifdef ALTQ 950 /* 951 * Start packet transmission on the interface. 952 * when the interface queue is rate-limited by ALTQ or TBR, 953 * if_start is needed to drain packets from the queue in order 954 * to notify readers when outgoing packets become ready. 955 * 956 * Should be called at splnet. 957 */ 958 static void 959 tunstart(struct ifnet *ifp) 960 { 961 struct tun_softc *tp = ifp->if_softc; 962 963 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 964 return; 965 966 simple_lock(&tp->tun_lock); 967 if (!IF_IS_EMPTY(&ifp->if_snd)) { 968 if (tp->tun_flags & TUN_RWAIT) { 969 tp->tun_flags &= ~TUN_RWAIT; 970 wakeup((caddr_t)tp); 971 } 972 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 973 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 974 POLLOUT|POLLWRNORM, NULL); 975 976 selwakeup(&tp->tun_rsel); 977 } 978 simple_unlock(&tp->tun_lock); 979 } 980 #endif /* ALTQ */ 981 /* 982 * tunpoll - the poll interface, this is only useful on reads 983 * really. The write detect always returns true, write never blocks 984 * anyway, it either accepts the packet or drops it. 985 */ 986 int 987 tunpoll(dev_t dev, int events, struct lwp *l) 988 { 989 struct tun_softc *tp; 990 struct ifnet *ifp; 991 int s, revents = 0; 992 993 s = splnet(); 994 tp = tun_find_unit(dev); 995 996 /* interface was "destroyed" already */ 997 if (tp == NULL) 998 goto out_nolock; 999 1000 ifp = &tp->tun_if; 1001 1002 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1003 1004 if (events & (POLLIN | POLLRDNORM)) { 1005 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1006 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1007 ifp->if_snd.ifq_len); 1008 revents |= events & (POLLIN | POLLRDNORM); 1009 } else { 1010 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1011 selrecord(l, &tp->tun_rsel); 1012 } 1013 } 1014 1015 if (events & (POLLOUT | POLLWRNORM)) 1016 revents |= events & (POLLOUT | POLLWRNORM); 1017 1018 simple_unlock(&tp->tun_lock); 1019 out_nolock: 1020 splx(s); 1021 return (revents); 1022 } 1023 1024 static void 1025 filt_tunrdetach(struct knote *kn) 1026 { 1027 struct tun_softc *tp = kn->kn_hook; 1028 int s; 1029 1030 s = splnet(); 1031 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1032 splx(s); 1033 } 1034 1035 static int 1036 filt_tunread(struct knote *kn, long hint) 1037 { 1038 struct tun_softc *tp = kn->kn_hook; 1039 struct ifnet *ifp = &tp->tun_if; 1040 struct mbuf *m; 1041 int s; 1042 1043 s = splnet(); 1044 IF_POLL(&ifp->if_snd, m); 1045 if (m == NULL) { 1046 splx(s); 1047 return (0); 1048 } 1049 1050 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1051 kn->kn_data += m->m_len; 1052 1053 splx(s); 1054 return (1); 1055 } 1056 1057 static const struct filterops tunread_filtops = 1058 { 1, NULL, filt_tunrdetach, filt_tunread }; 1059 1060 static const struct filterops tun_seltrue_filtops = 1061 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1062 1063 int 1064 tunkqfilter(dev_t dev, struct knote *kn) 1065 { 1066 struct tun_softc *tp; 1067 struct klist *klist; 1068 int rv = 0, s; 1069 1070 s = splnet(); 1071 tp = tun_find_unit(dev); 1072 if (tp == NULL) 1073 goto out_nolock; 1074 1075 switch (kn->kn_filter) { 1076 case EVFILT_READ: 1077 klist = &tp->tun_rsel.sel_klist; 1078 kn->kn_fop = &tunread_filtops; 1079 break; 1080 1081 case EVFILT_WRITE: 1082 klist = &tp->tun_rsel.sel_klist; 1083 kn->kn_fop = &tun_seltrue_filtops; 1084 break; 1085 1086 default: 1087 rv = 1; 1088 goto out; 1089 } 1090 1091 kn->kn_hook = tp; 1092 1093 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1094 1095 out: 1096 simple_unlock(&tp->tun_lock); 1097 out_nolock: 1098 splx(s); 1099 return (rv); 1100 } 1101
Indexes created Mon Oct 13 21:09:55 GMT 2025