if_tun.c revision 241610
1/* $NetBSD: if_tun.c,v 1.14 1994/06/29 06:36:25 cgd Exp $ */ 2 3/*- 4 * Copyright (c) 1988, Julian Onions <jpo@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 it's 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 * $FreeBSD: head/sys/net/if_tun.c 241610 2012-10-16 13:37:54Z glebius $ 17 */ 18 19#include "opt_atalk.h" 20#include "opt_inet.h" 21#include "opt_inet6.h" 22#include "opt_ipx.h" 23 24#include <sys/param.h> 25#include <sys/priv.h> 26#include <sys/proc.h> 27#include <sys/systm.h> 28#include <sys/jail.h> 29#include <sys/mbuf.h> 30#include <sys/module.h> 31#include <sys/socket.h> 32#include <sys/fcntl.h> 33#include <sys/filio.h> 34#include <sys/sockio.h> 35#include <sys/ttycom.h> 36#include <sys/poll.h> 37#include <sys/selinfo.h> 38#include <sys/signalvar.h> 39#include <sys/filedesc.h> 40#include <sys/kernel.h> 41#include <sys/sysctl.h> 42#include <sys/conf.h> 43#include <sys/uio.h> 44#include <sys/malloc.h> 45#include <sys/random.h> 46 47#include <net/if.h> 48#include <net/if_clone.h> 49#include <net/if_types.h> 50#include <net/netisr.h> 51#include <net/route.h> 52#include <net/vnet.h> 53#ifdef INET 54#include <netinet/in.h> 55#endif 56#include <net/bpf.h> 57#include <net/if_tun.h> 58 59#include <sys/queue.h> 60#include <sys/condvar.h> 61 62#include <security/mac/mac_framework.h> 63 64/* 65 * tun_list is protected by global tunmtx. Other mutable fields are 66 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is 67 * static for the duration of a tunnel interface. 68 */ 69struct tun_softc { 70 TAILQ_ENTRY(tun_softc) tun_list; 71 struct cdev *tun_dev; 72 u_short tun_flags; /* misc flags */ 73#define TUN_OPEN 0x0001 74#define TUN_INITED 0x0002 75#define TUN_RCOLL 0x0004 76#define TUN_IASET 0x0008 77#define TUN_DSTADDR 0x0010 78#define TUN_LMODE 0x0020 79#define TUN_RWAIT 0x0040 80#define TUN_ASYNC 0x0080 81#define TUN_IFHEAD 0x0100 82 83#define TUN_READY (TUN_OPEN | TUN_INITED) 84 85 /* 86 * XXXRW: tun_pid is used to exclusively lock /dev/tun. Is this 87 * actually needed? Can we just return EBUSY if already open? 88 * Problem is that this involved inherent races when a tun device 89 * is handed off from one process to another, as opposed to just 90 * being slightly stale informationally. 91 */ 92 pid_t tun_pid; /* owning pid */ 93 struct ifnet *tun_ifp; /* the interface */ 94 struct sigio *tun_sigio; /* information for async I/O */ 95 struct selinfo tun_rsel; /* read select */ 96 struct mtx tun_mtx; /* protect mutable softc fields */ 97 struct cv tun_cv; /* protect against ref'd dev destroy */ 98}; 99#define TUN2IFP(sc) ((sc)->tun_ifp) 100 101#define TUNDEBUG if (tundebug) if_printf 102 103/* 104 * All mutable global variables in if_tun are locked using tunmtx, with 105 * the exception of tundebug, which is used unlocked, and tunclones, 106 * which is static after setup. 107 */ 108static struct mtx tunmtx; 109static const char tunname[] = "tun"; 110static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface"); 111static int tundebug = 0; 112static int tundclone = 1; 113static struct clonedevs *tunclones; 114static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead); 115SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, ""); 116 117SYSCTL_DECL(_net_link); 118static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0, 119 "IP tunnel software network interface."); 120SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tundclone, 0, 121 "Enable legacy devfs interface creation."); 122 123TUNABLE_INT("net.link.tun.devfs_cloning", &tundclone); 124 125static void tunclone(void *arg, struct ucred *cred, char *name, 126 int namelen, struct cdev **dev); 127static void tuncreate(const char *name, struct cdev *dev); 128static int tunifioctl(struct ifnet *, u_long, caddr_t); 129static void tuninit(struct ifnet *); 130static int tunmodevent(module_t, int, void *); 131static int tunoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 132 struct route *ro); 133static void tunstart(struct ifnet *); 134 135static int tun_clone_create(struct if_clone *, int, caddr_t); 136static void tun_clone_destroy(struct ifnet *); 137static struct if_clone *tun_cloner; 138 139static d_open_t tunopen; 140static d_close_t tunclose; 141static d_read_t tunread; 142static d_write_t tunwrite; 143static d_ioctl_t tunioctl; 144static d_poll_t tunpoll; 145static d_kqfilter_t tunkqfilter; 146 147static int tunkqread(struct knote *, long); 148static int tunkqwrite(struct knote *, long); 149static void tunkqdetach(struct knote *); 150 151static struct filterops tun_read_filterops = { 152 .f_isfd = 1, 153 .f_attach = NULL, 154 .f_detach = tunkqdetach, 155 .f_event = tunkqread, 156}; 157 158static struct filterops tun_write_filterops = { 159 .f_isfd = 1, 160 .f_attach = NULL, 161 .f_detach = tunkqdetach, 162 .f_event = tunkqwrite, 163}; 164 165static struct cdevsw tun_cdevsw = { 166 .d_version = D_VERSION, 167 .d_flags = D_NEEDMINOR, 168 .d_open = tunopen, 169 .d_close = tunclose, 170 .d_read = tunread, 171 .d_write = tunwrite, 172 .d_ioctl = tunioctl, 173 .d_poll = tunpoll, 174 .d_kqfilter = tunkqfilter, 175 .d_name = tunname, 176}; 177 178static int 179tun_clone_create(struct if_clone *ifc, int unit, caddr_t params) 180{ 181 struct cdev *dev; 182 int i; 183 184 /* find any existing device, or allocate new unit number */ 185 i = clone_create(&tunclones, &tun_cdevsw, &unit, &dev, 0); 186 if (i) { 187 /* No preexisting struct cdev *, create one */ 188 dev = make_dev(&tun_cdevsw, unit, 189 UID_UUCP, GID_DIALER, 0600, "%s%d", tunname, unit); 190 } 191 tuncreate(tunname, dev); 192 193 return (0); 194} 195 196static void 197tunclone(void *arg, struct ucred *cred, char *name, int namelen, 198 struct cdev **dev) 199{ 200 char devname[SPECNAMELEN + 1]; 201 int u, i, append_unit; 202 203 if (*dev != NULL) 204 return; 205 206 /* 207 * If tun cloning is enabled, only the superuser can create an 208 * interface. 209 */ 210 if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0) 211 return; 212 213 if (strcmp(name, tunname) == 0) { 214 u = -1; 215 } else if (dev_stdclone(name, NULL, tunname, &u) != 1) 216 return; /* Don't recognise the name */ 217 if (u != -1 && u > IF_MAXUNIT) 218 return; /* Unit number too high */ 219 220 if (u == -1) 221 append_unit = 1; 222 else 223 append_unit = 0; 224 225 CURVNET_SET(CRED_TO_VNET(cred)); 226 /* find any existing device, or allocate new unit number */ 227 i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0); 228 if (i) { 229 if (append_unit) { 230 namelen = snprintf(devname, sizeof(devname), "%s%d", 231 name, u); 232 name = devname; 233 } 234 /* No preexisting struct cdev *, create one */ 235 *dev = make_dev_credf(MAKEDEV_REF, &tun_cdevsw, u, cred, 236 UID_UUCP, GID_DIALER, 0600, "%s", name); 237 } 238 239 if_clone_create(name, namelen, NULL); 240 CURVNET_RESTORE(); 241} 242 243static void 244tun_destroy(struct tun_softc *tp) 245{ 246 struct cdev *dev; 247 248 mtx_lock(&tp->tun_mtx); 249 if ((tp->tun_flags & TUN_OPEN) != 0) 250 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx); 251 else 252 mtx_unlock(&tp->tun_mtx); 253 254 CURVNET_SET(TUN2IFP(tp)->if_vnet); 255 dev = tp->tun_dev; 256 bpfdetach(TUN2IFP(tp)); 257 if_detach(TUN2IFP(tp)); 258 if_free(TUN2IFP(tp)); 259 destroy_dev(dev); 260 seldrain(&tp->tun_rsel); 261 knlist_destroy(&tp->tun_rsel.si_note); 262 mtx_destroy(&tp->tun_mtx); 263 cv_destroy(&tp->tun_cv); 264 free(tp, M_TUN); 265 CURVNET_RESTORE(); 266} 267 268static void 269tun_clone_destroy(struct ifnet *ifp) 270{ 271 struct tun_softc *tp = ifp->if_softc; 272 273 mtx_lock(&tunmtx); 274 TAILQ_REMOVE(&tunhead, tp, tun_list); 275 mtx_unlock(&tunmtx); 276 tun_destroy(tp); 277} 278 279static int 280tunmodevent(module_t mod, int type, void *data) 281{ 282 static eventhandler_tag tag; 283 struct tun_softc *tp; 284 285 switch (type) { 286 case MOD_LOAD: 287 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF); 288 clone_setup(&tunclones); 289 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000); 290 if (tag == NULL) 291 return (ENOMEM); 292 tun_cloner = if_clone_simple(tunname, tun_clone_create, 293 tun_clone_destroy, 0); 294 break; 295 case MOD_UNLOAD: 296 if_clone_detach(tun_cloner); 297 EVENTHANDLER_DEREGISTER(dev_clone, tag); 298 drain_dev_clone_events(); 299 300 mtx_lock(&tunmtx); 301 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) { 302 TAILQ_REMOVE(&tunhead, tp, tun_list); 303 mtx_unlock(&tunmtx); 304 tun_destroy(tp); 305 mtx_lock(&tunmtx); 306 } 307 mtx_unlock(&tunmtx); 308 clone_cleanup(&tunclones); 309 mtx_destroy(&tunmtx); 310 break; 311 default: 312 return EOPNOTSUPP; 313 } 314 return 0; 315} 316 317static moduledata_t tun_mod = { 318 "if_tun", 319 tunmodevent, 320 0 321}; 322 323DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 324 325static void 326tunstart(struct ifnet *ifp) 327{ 328 struct tun_softc *tp = ifp->if_softc; 329 struct mbuf *m; 330 331 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname); 332 if (ALTQ_IS_ENABLED(&ifp->if_snd)) { 333 IFQ_LOCK(&ifp->if_snd); 334 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 335 if (m == NULL) { 336 IFQ_UNLOCK(&ifp->if_snd); 337 return; 338 } 339 IFQ_UNLOCK(&ifp->if_snd); 340 } 341 342 mtx_lock(&tp->tun_mtx); 343 if (tp->tun_flags & TUN_RWAIT) { 344 tp->tun_flags &= ~TUN_RWAIT; 345 wakeup(tp); 346 } 347 selwakeuppri(&tp->tun_rsel, PZERO + 1); 348 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0); 349 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) { 350 mtx_unlock(&tp->tun_mtx); 351 pgsigio(&tp->tun_sigio, SIGIO, 0); 352 } else 353 mtx_unlock(&tp->tun_mtx); 354} 355 356/* XXX: should return an error code so it can fail. */ 357static void 358tuncreate(const char *name, struct cdev *dev) 359{ 360 struct tun_softc *sc; 361 struct ifnet *ifp; 362 363 dev->si_flags &= ~SI_CHEAPCLONE; 364 365 sc = malloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO); 366 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF); 367 cv_init(&sc->tun_cv, "tun_condvar"); 368 sc->tun_flags = TUN_INITED; 369 sc->tun_dev = dev; 370 mtx_lock(&tunmtx); 371 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list); 372 mtx_unlock(&tunmtx); 373 374 ifp = sc->tun_ifp = if_alloc(IFT_PPP); 375 if (ifp == NULL) 376 panic("%s%d: failed to if_alloc() interface.\n", 377 name, dev2unit(dev)); 378 if_initname(ifp, name, dev2unit(dev)); 379 ifp->if_mtu = TUNMTU; 380 ifp->if_ioctl = tunifioctl; 381 ifp->if_output = tunoutput; 382 ifp->if_start = tunstart; 383 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 384 ifp->if_softc = sc; 385 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen); 386 ifp->if_snd.ifq_drv_maxlen = 0; 387 IFQ_SET_READY(&ifp->if_snd); 388 knlist_init_mtx(&sc->tun_rsel.si_note, &sc->tun_mtx); 389 ifp->if_capabilities |= IFCAP_LINKSTATE; 390 ifp->if_capenable |= IFCAP_LINKSTATE; 391 392 if_attach(ifp); 393 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 394 dev->si_drv1 = sc; 395 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n", 396 ifp->if_xname, dev2unit(dev)); 397} 398 399static int 400tunopen(struct cdev *dev, int flag, int mode, struct thread *td) 401{ 402 struct ifnet *ifp; 403 struct tun_softc *tp; 404 405 /* 406 * XXXRW: Non-atomic test and set of dev->si_drv1 requires 407 * synchronization. 408 */ 409 tp = dev->si_drv1; 410 if (!tp) { 411 tuncreate(tunname, dev); 412 tp = dev->si_drv1; 413 } 414 415 /* 416 * XXXRW: This use of tun_pid is subject to error due to the 417 * fact that a reference to the tunnel can live beyond the 418 * death of the process that created it. Can we replace this 419 * with a simple busy flag? 420 */ 421 mtx_lock(&tp->tun_mtx); 422 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) { 423 mtx_unlock(&tp->tun_mtx); 424 return (EBUSY); 425 } 426 tp->tun_pid = td->td_proc->p_pid; 427 428 tp->tun_flags |= TUN_OPEN; 429 ifp = TUN2IFP(tp); 430 if_link_state_change(ifp, LINK_STATE_UP); 431 TUNDEBUG(ifp, "open\n"); 432 mtx_unlock(&tp->tun_mtx); 433 434 return (0); 435} 436 437/* 438 * tunclose - close the device - mark i/f down & delete 439 * routing info 440 */ 441static int 442tunclose(struct cdev *dev, int foo, int bar, struct thread *td) 443{ 444 struct tun_softc *tp; 445 struct ifnet *ifp; 446 447 tp = dev->si_drv1; 448 ifp = TUN2IFP(tp); 449 450 mtx_lock(&tp->tun_mtx); 451 tp->tun_flags &= ~TUN_OPEN; 452 tp->tun_pid = 0; 453 454 /* 455 * junk all pending output 456 */ 457 CURVNET_SET(ifp->if_vnet); 458 IFQ_PURGE(&ifp->if_snd); 459 460 if (ifp->if_flags & IFF_UP) { 461 mtx_unlock(&tp->tun_mtx); 462 if_down(ifp); 463 mtx_lock(&tp->tun_mtx); 464 } 465 466 /* Delete all addresses and routes which reference this interface. */ 467 if (ifp->if_drv_flags & IFF_DRV_RUNNING) { 468 struct ifaddr *ifa; 469 470 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 471 mtx_unlock(&tp->tun_mtx); 472 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 473 /* deal w/IPv4 PtP destination; unlocked read */ 474 if (ifa->ifa_addr->sa_family == AF_INET) { 475 rtinit(ifa, (int)RTM_DELETE, 476 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0); 477 } else { 478 rtinit(ifa, (int)RTM_DELETE, 0); 479 } 480 } 481 if_purgeaddrs(ifp); 482 mtx_lock(&tp->tun_mtx); 483 } 484 if_link_state_change(ifp, LINK_STATE_DOWN); 485 CURVNET_RESTORE(); 486 487 funsetown(&tp->tun_sigio); 488 selwakeuppri(&tp->tun_rsel, PZERO + 1); 489 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0); 490 TUNDEBUG (ifp, "closed\n"); 491 492 cv_broadcast(&tp->tun_cv); 493 mtx_unlock(&tp->tun_mtx); 494 return (0); 495} 496 497static void 498tuninit(struct ifnet *ifp) 499{ 500 struct tun_softc *tp = ifp->if_softc; 501#ifdef INET 502 struct ifaddr *ifa; 503#endif 504 505 TUNDEBUG(ifp, "tuninit\n"); 506 507 mtx_lock(&tp->tun_mtx); 508 ifp->if_flags |= IFF_UP; 509 ifp->if_drv_flags |= IFF_DRV_RUNNING; 510 getmicrotime(&ifp->if_lastchange); 511 512#ifdef INET 513 if_addr_rlock(ifp); 514 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 515 if (ifa->ifa_addr->sa_family == AF_INET) { 516 struct sockaddr_in *si; 517 518 si = (struct sockaddr_in *)ifa->ifa_addr; 519 if (si->sin_addr.s_addr) 520 tp->tun_flags |= TUN_IASET; 521 522 si = (struct sockaddr_in *)ifa->ifa_dstaddr; 523 if (si && si->sin_addr.s_addr) 524 tp->tun_flags |= TUN_DSTADDR; 525 } 526 } 527 if_addr_runlock(ifp); 528#endif 529 mtx_unlock(&tp->tun_mtx); 530} 531 532/* 533 * Process an ioctl request. 534 */ 535static int 536tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 537{ 538 struct ifreq *ifr = (struct ifreq *)data; 539 struct tun_softc *tp = ifp->if_softc; 540 struct ifstat *ifs; 541 int error = 0; 542 543 switch(cmd) { 544 case SIOCGIFSTATUS: 545 ifs = (struct ifstat *)data; 546 mtx_lock(&tp->tun_mtx); 547 if (tp->tun_pid) 548 sprintf(ifs->ascii + strlen(ifs->ascii), 549 "\tOpened by PID %d\n", tp->tun_pid); 550 mtx_unlock(&tp->tun_mtx); 551 break; 552 case SIOCSIFADDR: 553 tuninit(ifp); 554 TUNDEBUG(ifp, "address set\n"); 555 break; 556 case SIOCSIFDSTADDR: 557 tuninit(ifp); 558 TUNDEBUG(ifp, "destination address set\n"); 559 break; 560 case SIOCSIFMTU: 561 ifp->if_mtu = ifr->ifr_mtu; 562 TUNDEBUG(ifp, "mtu set\n"); 563 break; 564 case SIOCSIFFLAGS: 565 case SIOCADDMULTI: 566 case SIOCDELMULTI: 567 break; 568 default: 569 error = EINVAL; 570 } 571 return (error); 572} 573 574/* 575 * tunoutput - queue packets from higher level ready to put out. 576 */ 577static int 578tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 579 struct route *ro) 580{ 581 struct tun_softc *tp = ifp->if_softc; 582 u_short cached_tun_flags; 583 int error; 584 u_int32_t af; 585 586 TUNDEBUG (ifp, "tunoutput\n"); 587 588#ifdef MAC 589 error = mac_ifnet_check_transmit(ifp, m0); 590 if (error) { 591 m_freem(m0); 592 return (error); 593 } 594#endif 595 596 /* Could be unlocked read? */ 597 mtx_lock(&tp->tun_mtx); 598 cached_tun_flags = tp->tun_flags; 599 mtx_unlock(&tp->tun_mtx); 600 if ((cached_tun_flags & TUN_READY) != TUN_READY) { 601 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 602 m_freem (m0); 603 return (EHOSTDOWN); 604 } 605 606 if ((ifp->if_flags & IFF_UP) != IFF_UP) { 607 m_freem (m0); 608 return (EHOSTDOWN); 609 } 610 611 /* BPF writes need to be handled specially. */ 612 if (dst->sa_family == AF_UNSPEC) { 613 bcopy(dst->sa_data, &af, sizeof(af)); 614 dst->sa_family = af; 615 } 616 617 if (bpf_peers_present(ifp->if_bpf)) { 618 af = dst->sa_family; 619 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0); 620 } 621 622 /* prepend sockaddr? this may abort if the mbuf allocation fails */ 623 if (cached_tun_flags & TUN_LMODE) { 624 /* allocate space for sockaddr */ 625 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 626 627 /* if allocation failed drop packet */ 628 if (m0 == NULL) { 629 ifp->if_iqdrops++; 630 ifp->if_oerrors++; 631 return (ENOBUFS); 632 } else { 633 bcopy(dst, m0->m_data, dst->sa_len); 634 } 635 } 636 637 if (cached_tun_flags & TUN_IFHEAD) { 638 /* Prepend the address family */ 639 M_PREPEND(m0, 4, M_DONTWAIT); 640 641 /* if allocation failed drop packet */ 642 if (m0 == NULL) { 643 ifp->if_iqdrops++; 644 ifp->if_oerrors++; 645 return (ENOBUFS); 646 } else 647 *(u_int32_t *)m0->m_data = htonl(dst->sa_family); 648 } else { 649#ifdef INET 650 if (dst->sa_family != AF_INET) 651#endif 652 { 653 m_freem(m0); 654 return (EAFNOSUPPORT); 655 } 656 } 657 658 error = (ifp->if_transmit)(ifp, m0); 659 if (error) 660 return (ENOBUFS); 661 ifp->if_opackets++; 662 return (0); 663} 664 665/* 666 * the cdevsw interface is now pretty minimal. 667 */ 668static int 669tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, 670 struct thread *td) 671{ 672 int error; 673 struct tun_softc *tp = dev->si_drv1; 674 struct tuninfo *tunp; 675 676 switch (cmd) { 677 case TUNSIFINFO: 678 tunp = (struct tuninfo *)data; 679 if (tunp->mtu < IF_MINMTU) 680 return (EINVAL); 681 if (TUN2IFP(tp)->if_mtu != tunp->mtu) { 682 error = priv_check(td, PRIV_NET_SETIFMTU); 683 if (error) 684 return (error); 685 } 686 mtx_lock(&tp->tun_mtx); 687 TUN2IFP(tp)->if_mtu = tunp->mtu; 688 TUN2IFP(tp)->if_type = tunp->type; 689 TUN2IFP(tp)->if_baudrate = tunp->baudrate; 690 mtx_unlock(&tp->tun_mtx); 691 break; 692 case TUNGIFINFO: 693 tunp = (struct tuninfo *)data; 694 mtx_lock(&tp->tun_mtx); 695 tunp->mtu = TUN2IFP(tp)->if_mtu; 696 tunp->type = TUN2IFP(tp)->if_type; 697 tunp->baudrate = TUN2IFP(tp)->if_baudrate; 698 mtx_unlock(&tp->tun_mtx); 699 break; 700 case TUNSDEBUG: 701 tundebug = *(int *)data; 702 break; 703 case TUNGDEBUG: 704 *(int *)data = tundebug; 705 break; 706 case TUNSLMODE: 707 mtx_lock(&tp->tun_mtx); 708 if (*(int *)data) { 709 tp->tun_flags |= TUN_LMODE; 710 tp->tun_flags &= ~TUN_IFHEAD; 711 } else 712 tp->tun_flags &= ~TUN_LMODE; 713 mtx_unlock(&tp->tun_mtx); 714 break; 715 case TUNSIFHEAD: 716 mtx_lock(&tp->tun_mtx); 717 if (*(int *)data) { 718 tp->tun_flags |= TUN_IFHEAD; 719 tp->tun_flags &= ~TUN_LMODE; 720 } else 721 tp->tun_flags &= ~TUN_IFHEAD; 722 mtx_unlock(&tp->tun_mtx); 723 break; 724 case TUNGIFHEAD: 725 mtx_lock(&tp->tun_mtx); 726 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 727 mtx_unlock(&tp->tun_mtx); 728 break; 729 case TUNSIFMODE: 730 /* deny this if UP */ 731 if (TUN2IFP(tp)->if_flags & IFF_UP) 732 return(EBUSY); 733 734 switch (*(int *)data & ~IFF_MULTICAST) { 735 case IFF_POINTOPOINT: 736 case IFF_BROADCAST: 737 mtx_lock(&tp->tun_mtx); 738 TUN2IFP(tp)->if_flags &= 739 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 740 TUN2IFP(tp)->if_flags |= *(int *)data; 741 mtx_unlock(&tp->tun_mtx); 742 break; 743 default: 744 return(EINVAL); 745 } 746 break; 747 case TUNSIFPID: 748 mtx_lock(&tp->tun_mtx); 749 tp->tun_pid = curthread->td_proc->p_pid; 750 mtx_unlock(&tp->tun_mtx); 751 break; 752 case FIONBIO: 753 break; 754 case FIOASYNC: 755 mtx_lock(&tp->tun_mtx); 756 if (*(int *)data) 757 tp->tun_flags |= TUN_ASYNC; 758 else 759 tp->tun_flags &= ~TUN_ASYNC; 760 mtx_unlock(&tp->tun_mtx); 761 break; 762 case FIONREAD: 763 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) { 764 struct mbuf *mb; 765 IFQ_LOCK(&TUN2IFP(tp)->if_snd); 766 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb); 767 for (*(int *)data = 0; mb != NULL; mb = mb->m_next) 768 *(int *)data += mb->m_len; 769 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd); 770 } else 771 *(int *)data = 0; 772 break; 773 case FIOSETOWN: 774 return (fsetown(*(int *)data, &tp->tun_sigio)); 775 776 case FIOGETOWN: 777 *(int *)data = fgetown(&tp->tun_sigio); 778 return (0); 779 780 /* This is deprecated, FIOSETOWN should be used instead. */ 781 case TIOCSPGRP: 782 return (fsetown(-(*(int *)data), &tp->tun_sigio)); 783 784 /* This is deprecated, FIOGETOWN should be used instead. */ 785 case TIOCGPGRP: 786 *(int *)data = -fgetown(&tp->tun_sigio); 787 return (0); 788 789 default: 790 return (ENOTTY); 791 } 792 return (0); 793} 794 795/* 796 * The cdevsw read interface - reads a packet at a time, or at 797 * least as much of a packet as can be read. 798 */ 799static int 800tunread(struct cdev *dev, struct uio *uio, int flag) 801{ 802 struct tun_softc *tp = dev->si_drv1; 803 struct ifnet *ifp = TUN2IFP(tp); 804 struct mbuf *m; 805 int error=0, len; 806 807 TUNDEBUG (ifp, "read\n"); 808 mtx_lock(&tp->tun_mtx); 809 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 810 mtx_unlock(&tp->tun_mtx); 811 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 812 return (EHOSTDOWN); 813 } 814 815 tp->tun_flags &= ~TUN_RWAIT; 816 817 do { 818 IFQ_DEQUEUE(&ifp->if_snd, m); 819 if (m == NULL) { 820 if (flag & O_NONBLOCK) { 821 mtx_unlock(&tp->tun_mtx); 822 return (EWOULDBLOCK); 823 } 824 tp->tun_flags |= TUN_RWAIT; 825 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1), 826 "tunread", 0); 827 if (error != 0) { 828 mtx_unlock(&tp->tun_mtx); 829 return (error); 830 } 831 } 832 } while (m == NULL); 833 mtx_unlock(&tp->tun_mtx); 834 835 while (m && uio->uio_resid > 0 && error == 0) { 836 len = min(uio->uio_resid, m->m_len); 837 if (len != 0) 838 error = uiomove(mtod(m, void *), len, uio); 839 m = m_free(m); 840 } 841 842 if (m) { 843 TUNDEBUG(ifp, "Dropping mbuf\n"); 844 m_freem(m); 845 } 846 return (error); 847} 848 849/* 850 * the cdevsw write interface - an atomic write is a packet - or else! 851 */ 852static int 853tunwrite(struct cdev *dev, struct uio *uio, int flag) 854{ 855 struct tun_softc *tp = dev->si_drv1; 856 struct ifnet *ifp = TUN2IFP(tp); 857 struct mbuf *m; 858 uint32_t family; 859 int isr; 860 861 TUNDEBUG(ifp, "tunwrite\n"); 862 863 if ((ifp->if_flags & IFF_UP) != IFF_UP) 864 /* ignore silently */ 865 return (0); 866 867 if (uio->uio_resid == 0) 868 return (0); 869 870 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) { 871 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid); 872 return (EIO); 873 } 874 875 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) { 876 ifp->if_ierrors++; 877 return (ENOBUFS); 878 } 879 880 m->m_pkthdr.rcvif = ifp; 881#ifdef MAC 882 mac_ifnet_create_mbuf(ifp, m); 883#endif 884 885 /* Could be unlocked read? */ 886 mtx_lock(&tp->tun_mtx); 887 if (tp->tun_flags & TUN_IFHEAD) { 888 mtx_unlock(&tp->tun_mtx); 889 if (m->m_len < sizeof(family) && 890 (m = m_pullup(m, sizeof(family))) == NULL) 891 return (ENOBUFS); 892 family = ntohl(*mtod(m, u_int32_t *)); 893 m_adj(m, sizeof(family)); 894 } else { 895 mtx_unlock(&tp->tun_mtx); 896 family = AF_INET; 897 } 898 899 BPF_MTAP2(ifp, &family, sizeof(family), m); 900 901 switch (family) { 902#ifdef INET 903 case AF_INET: 904 isr = NETISR_IP; 905 break; 906#endif 907#ifdef INET6 908 case AF_INET6: 909 isr = NETISR_IPV6; 910 break; 911#endif 912#ifdef IPX 913 case AF_IPX: 914 isr = NETISR_IPX; 915 break; 916#endif 917#ifdef NETATALK 918 case AF_APPLETALK: 919 isr = NETISR_ATALK2; 920 break; 921#endif 922 default: 923 m_freem(m); 924 return (EAFNOSUPPORT); 925 } 926 /* First chunk of an mbuf contains good junk */ 927 if (harvest.point_to_point) 928 random_harvest(m, 16, 3, 0, RANDOM_NET); 929 ifp->if_ibytes += m->m_pkthdr.len; 930 ifp->if_ipackets++; 931 CURVNET_SET(ifp->if_vnet); 932 M_SETFIB(m, ifp->if_fib); 933 netisr_dispatch(isr, m); 934 CURVNET_RESTORE(); 935 return (0); 936} 937 938/* 939 * tunpoll - the poll interface, this is only useful on reads 940 * really. The write detect always returns true, write never blocks 941 * anyway, it either accepts the packet or drops it. 942 */ 943static int 944tunpoll(struct cdev *dev, int events, struct thread *td) 945{ 946 struct tun_softc *tp = dev->si_drv1; 947 struct ifnet *ifp = TUN2IFP(tp); 948 int revents = 0; 949 struct mbuf *m; 950 951 TUNDEBUG(ifp, "tunpoll\n"); 952 953 if (events & (POLLIN | POLLRDNORM)) { 954 IFQ_LOCK(&ifp->if_snd); 955 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 956 if (m != NULL) { 957 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len); 958 revents |= events & (POLLIN | POLLRDNORM); 959 } else { 960 TUNDEBUG(ifp, "tunpoll waiting\n"); 961 selrecord(td, &tp->tun_rsel); 962 } 963 IFQ_UNLOCK(&ifp->if_snd); 964 } 965 if (events & (POLLOUT | POLLWRNORM)) 966 revents |= events & (POLLOUT | POLLWRNORM); 967 968 return (revents); 969} 970 971/* 972 * tunkqfilter - support for the kevent() system call. 973 */ 974static int 975tunkqfilter(struct cdev *dev, struct knote *kn) 976{ 977 struct tun_softc *tp = dev->si_drv1; 978 struct ifnet *ifp = TUN2IFP(tp); 979 980 switch(kn->kn_filter) { 981 case EVFILT_READ: 982 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n", 983 ifp->if_xname, dev2unit(dev)); 984 kn->kn_fop = &tun_read_filterops; 985 break; 986 987 case EVFILT_WRITE: 988 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n", 989 ifp->if_xname, dev2unit(dev)); 990 kn->kn_fop = &tun_write_filterops; 991 break; 992 993 default: 994 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n", 995 ifp->if_xname, dev2unit(dev)); 996 return(EINVAL); 997 } 998 999 kn->kn_hook = tp; 1000 knlist_add(&tp->tun_rsel.si_note, kn, 0); 1001 1002 return (0); 1003} 1004 1005/* 1006 * Return true of there is data in the interface queue. 1007 */ 1008static int 1009tunkqread(struct knote *kn, long hint) 1010{ 1011 int ret; 1012 struct tun_softc *tp = kn->kn_hook; 1013 struct cdev *dev = tp->tun_dev; 1014 struct ifnet *ifp = TUN2IFP(tp); 1015 1016 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) { 1017 TUNDEBUG(ifp, 1018 "%s have data in the queue. Len = %d, minor = %#x\n", 1019 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev)); 1020 ret = 1; 1021 } else { 1022 TUNDEBUG(ifp, 1023 "%s waiting for data, minor = %#x\n", ifp->if_xname, 1024 dev2unit(dev)); 1025 ret = 0; 1026 } 1027 1028 return (ret); 1029} 1030 1031/* 1032 * Always can write, always return MTU in kn->data. 1033 */ 1034static int 1035tunkqwrite(struct knote *kn, long hint) 1036{ 1037 struct tun_softc *tp = kn->kn_hook; 1038 struct ifnet *ifp = TUN2IFP(tp); 1039 1040 kn->kn_data = ifp->if_mtu; 1041 1042 return (1); 1043} 1044 1045static void 1046tunkqdetach(struct knote *kn) 1047{ 1048 struct tun_softc *tp = kn->kn_hook; 1049 1050 knlist_remove(&tp->tun_rsel.si_note, kn, 0); 1051} 1052