if_tun.c revision 1.102
1 /* $NetBSD: if_tun.c,v 1.102 2008/02/07 01:22:02 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 1.102 2008/02/07 01:22:02 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 #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 struct ifreq *ifr = data; 428 429 s = splnet(); 430 simple_lock(&tp->tun_lock); 431 432 switch (cmd) { 433 case SIOCSIFADDR: 434 tuninit(tp); 435 TUNDEBUG("%s: address set\n", ifp->if_xname); 436 break; 437 case SIOCSIFDSTADDR: 438 tuninit(tp); 439 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 440 break; 441 case SIOCSIFBRDADDR: 442 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 443 break; 444 case SIOCSIFMTU: 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 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 451 error = 0; 452 break; 453 case SIOCADDMULTI: 454 case SIOCDELMULTI: 455 if (ifr == NULL) { 456 error = EAFNOSUPPORT; /* XXX */ 457 break; 458 } 459 switch (ifreq_getaddr(cmd, ifr)->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 case SIOCSIFFLAGS: 474 break; 475 default: 476 error = EINVAL; 477 } 478 479 simple_unlock(&tp->tun_lock); 480 splx(s); 481 return (error); 482 } 483 484 /* 485 * tun_output - queue packets from higher level ready to put out. 486 */ 487 static int 488 tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 489 struct rtentry *rt) 490 { 491 struct tun_softc *tp = ifp->if_softc; 492 int s; 493 int error; 494 #if defined(INET) || defined(INET6) 495 int mlen; 496 uint32_t *af; 497 #endif 498 ALTQ_DECL(struct altq_pktattr pktattr;) 499 500 s = splnet(); 501 simple_lock(&tp->tun_lock); 502 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 503 504 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 505 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 506 tp->tun_flags); 507 m_freem (m0); 508 error = EHOSTDOWN; 509 goto out; 510 } 511 512 /* 513 * if the queueing discipline needs packet classification, 514 * do it before prepending link headers. 515 */ 516 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 517 518 #if NBPFILTER > 0 519 if (ifp->if_bpf) 520 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0); 521 #endif 522 523 switch(dst->sa_family) { 524 #ifdef INET6 525 case AF_INET6: 526 #endif 527 #ifdef INET 528 case AF_INET: 529 #endif 530 #if defined(INET) || defined(INET6) 531 if (tp->tun_flags & TUN_PREPADDR) { 532 /* Simple link-layer header */ 533 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 534 if (m0 == NULL) { 535 IF_DROP(&ifp->if_snd); 536 error = ENOBUFS; 537 goto out; 538 } 539 bcopy(dst, mtod(m0, char *), dst->sa_len); 540 } 541 542 if (tp->tun_flags & TUN_IFHEAD) { 543 /* Prepend the address family */ 544 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 545 if (m0 == NULL) { 546 IF_DROP(&ifp->if_snd); 547 error = ENOBUFS; 548 goto out; 549 } 550 af = mtod(m0,uint32_t *); 551 *af = htonl(dst->sa_family); 552 } else { 553 #ifdef INET 554 if (dst->sa_family != AF_INET) 555 #endif 556 { 557 m_freem(m0); 558 error = EAFNOSUPPORT; 559 goto out; 560 } 561 } 562 /* FALLTHROUGH */ 563 case AF_UNSPEC: 564 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 565 if (error) { 566 ifp->if_collisions++; 567 error = EAFNOSUPPORT; 568 goto out; 569 } 570 mlen = m0->m_pkthdr.len; 571 ifp->if_opackets++; 572 ifp->if_obytes += mlen; 573 break; 574 #endif 575 default: 576 m_freem(m0); 577 error = EAFNOSUPPORT; 578 goto out; 579 } 580 581 if (tp->tun_flags & TUN_RWAIT) { 582 tp->tun_flags &= ~TUN_RWAIT; 583 wakeup((void *)tp); 584 } 585 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 586 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 587 NULL); 588 589 selnotify(&tp->tun_rsel, 0); 590 out: 591 simple_unlock(&tp->tun_lock); 592 splx(s); 593 return (0); 594 } 595 596 /* 597 * the cdevsw interface is now pretty minimal. 598 */ 599 int 600 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 601 { 602 struct tun_softc *tp; 603 int s, error = 0; 604 605 s = splnet(); 606 tp = tun_find_unit(dev); 607 608 /* interface was "destroyed" already */ 609 if (tp == NULL) { 610 error = ENXIO; 611 goto out_nolock; 612 } 613 614 switch (cmd) { 615 case TUNSDEBUG: 616 tundebug = *(int *)data; 617 break; 618 619 case TUNGDEBUG: 620 *(int *)data = tundebug; 621 break; 622 623 case TUNSIFMODE: 624 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 625 case IFF_POINTOPOINT: 626 case IFF_BROADCAST: 627 if (tp->tun_if.if_flags & IFF_UP) { 628 error = EBUSY; 629 goto out; 630 } 631 tp->tun_if.if_flags &= 632 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 633 tp->tun_if.if_flags |= *(int *)data; 634 break; 635 default: 636 error = EINVAL; 637 goto out; 638 } 639 break; 640 641 case TUNSLMODE: 642 if (*(int *)data) { 643 tp->tun_flags |= TUN_PREPADDR; 644 tp->tun_flags &= ~TUN_IFHEAD; 645 } else 646 tp->tun_flags &= ~TUN_PREPADDR; 647 break; 648 649 case TUNSIFHEAD: 650 if (*(int *)data) { 651 tp->tun_flags |= TUN_IFHEAD; 652 tp->tun_flags &= ~TUN_PREPADDR; 653 } else 654 tp->tun_flags &= ~TUN_IFHEAD; 655 break; 656 657 case TUNGIFHEAD: 658 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 659 break; 660 661 case FIONBIO: 662 if (*(int *)data) 663 tp->tun_flags |= TUN_NBIO; 664 else 665 tp->tun_flags &= ~TUN_NBIO; 666 break; 667 668 case FIOASYNC: 669 if (*(int *)data) 670 tp->tun_flags |= TUN_ASYNC; 671 else 672 tp->tun_flags &= ~TUN_ASYNC; 673 break; 674 675 case FIONREAD: 676 if (tp->tun_if.if_snd.ifq_head) 677 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 678 else 679 *(int *)data = 0; 680 break; 681 682 case TIOCSPGRP: 683 case FIOSETOWN: 684 error = fsetown(l->l_proc, &tp->tun_pgid, cmd, data); 685 break; 686 687 case TIOCGPGRP: 688 case FIOGETOWN: 689 error = fgetown(l->l_proc, tp->tun_pgid, cmd, data); 690 break; 691 692 default: 693 error = ENOTTY; 694 } 695 696 out: 697 simple_unlock(&tp->tun_lock); 698 out_nolock: 699 splx(s); 700 return (error); 701 } 702 703 /* 704 * The cdevsw read interface - reads a packet at a time, or at 705 * least as much of a packet as can be read. 706 */ 707 int 708 tunread(dev_t dev, struct uio *uio, int ioflag) 709 { 710 struct tun_softc *tp; 711 struct ifnet *ifp; 712 struct mbuf *m, *m0; 713 int error = 0, len, s, index; 714 715 s = splnet(); 716 tp = tun_find_unit(dev); 717 718 /* interface was "destroyed" already */ 719 if (tp == NULL) { 720 error = ENXIO; 721 goto out_nolock; 722 } 723 724 index = tp->tun_if.if_index; 725 ifp = &tp->tun_if; 726 727 TUNDEBUG ("%s: read\n", ifp->if_xname); 728 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 729 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 730 error = EHOSTDOWN; 731 goto out; 732 } 733 734 tp->tun_flags &= ~TUN_RWAIT; 735 736 do { 737 IFQ_DEQUEUE(&ifp->if_snd, m0); 738 if (m0 == 0) { 739 if (tp->tun_flags & TUN_NBIO) { 740 error = EWOULDBLOCK; 741 goto out; 742 } 743 tp->tun_flags |= TUN_RWAIT; 744 if (ltsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 745 "tunread", 0, &tp->tun_lock) != 0) { 746 error = EINTR; 747 goto out_nolock; 748 } else { 749 /* 750 * Maybe the interface was destroyed while 751 * we were sleeping, so let's ensure that 752 * we're looking at the same (valid) tun 753 * interface before looping. 754 */ 755 tp = tun_find_unit(dev); 756 if (tp == NULL) { 757 error = ENXIO; 758 goto out_nolock; 759 } 760 if (tp->tun_if.if_index != index) { 761 error = ENXIO; 762 goto out; 763 } 764 } 765 } 766 } while (m0 == 0); 767 768 simple_unlock(&tp->tun_lock); 769 splx(s); 770 771 /* Copy the mbuf chain */ 772 while (m0 && uio->uio_resid > 0 && error == 0) { 773 len = min(uio->uio_resid, m0->m_len); 774 if (len != 0) 775 error = uiomove(mtod(m0, void *), len, uio); 776 MFREE(m0, m); 777 m0 = m; 778 } 779 780 if (m0) { 781 TUNDEBUG("Dropping mbuf\n"); 782 m_freem(m0); 783 } 784 if (error) 785 ifp->if_ierrors++; 786 787 return (error); 788 789 out: 790 simple_unlock(&tp->tun_lock); 791 out_nolock: 792 splx(s); 793 return (error); 794 } 795 796 /* 797 * the cdevsw write interface - an atomic write is a packet - or else! 798 */ 799 int 800 tunwrite(dev_t dev, struct uio *uio, int ioflag) 801 { 802 struct tun_softc *tp; 803 struct ifnet *ifp; 804 struct mbuf *top, **mp, *m; 805 struct ifqueue *ifq; 806 struct sockaddr dst; 807 int isr, error = 0, s, tlen, mlen; 808 uint32_t family; 809 810 s = splnet(); 811 tp = tun_find_unit(dev); 812 813 /* interface was "destroyed" already */ 814 if (tp == NULL) { 815 error = ENXIO; 816 goto out_nolock; 817 } 818 819 /* Unlock until we've got the data */ 820 simple_unlock(&tp->tun_lock); 821 splx(s); 822 823 ifp = &tp->tun_if; 824 825 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 826 827 if (tp->tun_flags & TUN_PREPADDR) { 828 if (uio->uio_resid < sizeof(dst)) { 829 error = EIO; 830 goto out0; 831 } 832 error = uiomove((void *)&dst, sizeof(dst), uio); 833 if (dst.sa_len > sizeof(dst)) { 834 /* Duh.. */ 835 char discard; 836 int n = dst.sa_len - sizeof(dst); 837 while (n--) 838 if ((error = uiomove(&discard, 1, uio)) != 0) { 839 goto out0; 840 } 841 } 842 } else if (tp->tun_flags & TUN_IFHEAD) { 843 if (uio->uio_resid < sizeof(family)){ 844 error = EIO; 845 goto out0; 846 } 847 error = uiomove((void *)&family, sizeof(family), uio); 848 dst.sa_family = ntohl(family); 849 } else { 850 #ifdef INET 851 dst.sa_family = AF_INET; 852 #endif 853 } 854 855 if (uio->uio_resid > TUNMTU) { 856 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 857 (unsigned long)uio->uio_resid); 858 error = EIO; 859 goto out0; 860 } 861 862 switch (dst.sa_family) { 863 #ifdef INET 864 case AF_INET: 865 ifq = &ipintrq; 866 isr = NETISR_IP; 867 break; 868 #endif 869 #ifdef INET6 870 case AF_INET6: 871 ifq = &ip6intrq; 872 isr = NETISR_IPV6; 873 break; 874 #endif 875 default: 876 error = EAFNOSUPPORT; 877 goto out0; 878 } 879 880 tlen = uio->uio_resid; 881 882 /* get a header mbuf */ 883 MGETHDR(m, M_DONTWAIT, MT_DATA); 884 if (m == NULL) { 885 error = ENOBUFS; 886 goto out0; 887 } 888 mlen = MHLEN; 889 890 top = NULL; 891 mp = ⊤ 892 while (error == 0 && uio->uio_resid > 0) { 893 m->m_len = min(mlen, uio->uio_resid); 894 error = uiomove(mtod(m, void *), m->m_len, uio); 895 *mp = m; 896 mp = &m->m_next; 897 if (error == 0 && uio->uio_resid > 0) { 898 MGET(m, M_DONTWAIT, MT_DATA); 899 if (m == NULL) { 900 error = ENOBUFS; 901 break; 902 } 903 mlen = MLEN; 904 } 905 } 906 if (error) { 907 if (top != NULL) 908 m_freem (top); 909 ifp->if_ierrors++; 910 goto out0; 911 } 912 913 top->m_pkthdr.len = tlen; 914 top->m_pkthdr.rcvif = ifp; 915 916 #if NBPFILTER > 0 917 if (ifp->if_bpf) 918 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 919 #endif 920 921 s = splnet(); 922 simple_lock(&tp->tun_lock); 923 if ((tp->tun_flags & TUN_INITED) == 0) { 924 /* Interface was destroyed */ 925 error = ENXIO; 926 goto out; 927 } 928 if (IF_QFULL(ifq)) { 929 IF_DROP(ifq); 930 ifp->if_collisions++; 931 m_freem(top); 932 error = ENOBUFS; 933 goto out; 934 } 935 936 IF_ENQUEUE(ifq, top); 937 ifp->if_ipackets++; 938 ifp->if_ibytes += tlen; 939 schednetisr(isr); 940 out: 941 simple_unlock(&tp->tun_lock); 942 out_nolock: 943 splx(s); 944 out0: 945 return (error); 946 } 947 948 #ifdef ALTQ 949 /* 950 * Start packet transmission on the interface. 951 * when the interface queue is rate-limited by ALTQ or TBR, 952 * if_start is needed to drain packets from the queue in order 953 * to notify readers when outgoing packets become ready. 954 * 955 * Should be called at splnet. 956 */ 957 static void 958 tunstart(struct ifnet *ifp) 959 { 960 struct tun_softc *tp = ifp->if_softc; 961 962 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 963 return; 964 965 simple_lock(&tp->tun_lock); 966 if (!IF_IS_EMPTY(&ifp->if_snd)) { 967 if (tp->tun_flags & TUN_RWAIT) { 968 tp->tun_flags &= ~TUN_RWAIT; 969 wakeup((void *)tp); 970 } 971 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 972 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 973 POLLOUT|POLLWRNORM, NULL); 974 975 selwakeup(&tp->tun_rsel); 976 } 977 simple_unlock(&tp->tun_lock); 978 } 979 #endif /* ALTQ */ 980 /* 981 * tunpoll - the poll interface, this is only useful on reads 982 * really. The write detect always returns true, write never blocks 983 * anyway, it either accepts the packet or drops it. 984 */ 985 int 986 tunpoll(dev_t dev, int events, struct lwp *l) 987 { 988 struct tun_softc *tp; 989 struct ifnet *ifp; 990 int s, revents = 0; 991 992 s = splnet(); 993 tp = tun_find_unit(dev); 994 995 /* interface was "destroyed" already */ 996 if (tp == NULL) 997 goto out_nolock; 998 999 ifp = &tp->tun_if; 1000 1001 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1002 1003 if (events & (POLLIN | POLLRDNORM)) { 1004 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1005 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1006 ifp->if_snd.ifq_len); 1007 revents |= events & (POLLIN | POLLRDNORM); 1008 } else { 1009 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1010 selrecord(l, &tp->tun_rsel); 1011 } 1012 } 1013 1014 if (events & (POLLOUT | POLLWRNORM)) 1015 revents |= events & (POLLOUT | POLLWRNORM); 1016 1017 simple_unlock(&tp->tun_lock); 1018 out_nolock: 1019 splx(s); 1020 return (revents); 1021 } 1022 1023 static void 1024 filt_tunrdetach(struct knote *kn) 1025 { 1026 struct tun_softc *tp = kn->kn_hook; 1027 int s; 1028 1029 s = splnet(); 1030 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1031 splx(s); 1032 } 1033 1034 static int 1035 filt_tunread(struct knote *kn, long hint) 1036 { 1037 struct tun_softc *tp = kn->kn_hook; 1038 struct ifnet *ifp = &tp->tun_if; 1039 struct mbuf *m; 1040 int s; 1041 1042 s = splnet(); 1043 IF_POLL(&ifp->if_snd, m); 1044 if (m == NULL) { 1045 splx(s); 1046 return (0); 1047 } 1048 1049 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1050 kn->kn_data += m->m_len; 1051 1052 splx(s); 1053 return (1); 1054 } 1055 1056 static const struct filterops tunread_filtops = 1057 { 1, NULL, filt_tunrdetach, filt_tunread }; 1058 1059 static const struct filterops tun_seltrue_filtops = 1060 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1061 1062 int 1063 tunkqfilter(dev_t dev, struct knote *kn) 1064 { 1065 struct tun_softc *tp; 1066 struct klist *klist; 1067 int rv = 0, s; 1068 1069 s = splnet(); 1070 tp = tun_find_unit(dev); 1071 if (tp == NULL) 1072 goto out_nolock; 1073 1074 switch (kn->kn_filter) { 1075 case EVFILT_READ: 1076 klist = &tp->tun_rsel.sel_klist; 1077 kn->kn_fop = &tunread_filtops; 1078 break; 1079 1080 case EVFILT_WRITE: 1081 klist = &tp->tun_rsel.sel_klist; 1082 kn->kn_fop = &tun_seltrue_filtops; 1083 break; 1084 1085 default: 1086 rv = EINVAL; 1087 goto out; 1088 } 1089 1090 kn->kn_hook = tp; 1091 1092 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1093 1094 out: 1095 simple_unlock(&tp->tun_lock); 1096 out_nolock: 1097 splx(s); 1098 return (rv); 1099 } 1100
Indexes created Tue Sep 23 07:09:52 GMT 2025