if_tun.c revision 184205
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 184205 2008-10-23 15:53:51Z des $ 17 */ 18 19#include "opt_atalk.h" 20#include "opt_inet.h" 21#include "opt_inet6.h" 22#include "opt_ipx.h" 23#include "opt_mac.h" 24 25#include <sys/param.h> 26#include <sys/priv.h> 27#include <sys/proc.h> 28#include <sys/systm.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#include <sys/vimage.h> 47 48#include <net/if.h> 49#include <net/if_clone.h> 50#include <net/if_types.h> 51#include <net/netisr.h> 52#include <net/route.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 61#include <security/mac/mac_framework.h> 62 63/* 64 * tun_list is protected by global tunmtx. Other mutable fields are 65 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is 66 * static for the duration of a tunnel interface. 67 */ 68struct tun_softc { 69 TAILQ_ENTRY(tun_softc) tun_list; 70 struct cdev *tun_dev; 71 u_short tun_flags; /* misc flags */ 72#define TUN_OPEN 0x0001 73#define TUN_INITED 0x0002 74#define TUN_RCOLL 0x0004 75#define TUN_IASET 0x0008 76#define TUN_DSTADDR 0x0010 77#define TUN_LMODE 0x0020 78#define TUN_RWAIT 0x0040 79#define TUN_ASYNC 0x0080 80#define TUN_IFHEAD 0x0100 81 82#define TUN_READY (TUN_OPEN | TUN_INITED) 83 84 /* 85 * XXXRW: tun_pid is used to exclusively lock /dev/tun. Is this 86 * actually needed? Can we just return EBUSY if already open? 87 * Problem is that this involved inherent races when a tun device 88 * is handed off from one process to another, as opposed to just 89 * being slightly stale informationally. 90 */ 91 pid_t tun_pid; /* owning pid */ 92 struct ifnet *tun_ifp; /* the interface */ 93 struct sigio *tun_sigio; /* information for async I/O */ 94 struct selinfo tun_rsel; /* read select */ 95 struct mtx tun_mtx; /* protect mutable softc fields */ 96}; 97#define TUN2IFP(sc) ((sc)->tun_ifp) 98 99#define TUNDEBUG if (tundebug) if_printf 100#define TUNNAME "tun" 101 102/* 103 * All mutable global variables in if_tun are locked using tunmtx, with 104 * the exception of tundebug, which is used unlocked, and tunclones, 105 * which is static after setup. 106 */ 107static struct mtx tunmtx; 108static MALLOC_DEFINE(M_TUN, TUNNAME, "Tunnel Interface"); 109static int tundebug = 0; 110static int tundclone = 1; 111static struct clonedevs *tunclones; 112static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead); 113SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, ""); 114 115SYSCTL_DECL(_net_link); 116SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0, 117 "IP tunnel software network interface."); 118SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tundclone, 0, 119 "Enable legacy devfs interface creation."); 120 121TUNABLE_INT("net.link.tun.devfs_cloning", &tundclone); 122 123static void tunclone(void *arg, struct ucred *cred, char *name, 124 int namelen, struct cdev **dev); 125static void tuncreate(const char *name, struct cdev *dev); 126static int tunifioctl(struct ifnet *, u_long, caddr_t); 127static int tuninit(struct ifnet *); 128static int tunmodevent(module_t, int, void *); 129static int tunoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 130 struct rtentry *rt); 131static void tunstart(struct ifnet *); 132 133static int tun_clone_create(struct if_clone *, int, caddr_t); 134static void tun_clone_destroy(struct ifnet *); 135 136IFC_SIMPLE_DECLARE(tun, 0); 137 138static d_open_t tunopen; 139static d_close_t tunclose; 140static d_read_t tunread; 141static d_write_t tunwrite; 142static d_ioctl_t tunioctl; 143static d_poll_t tunpoll; 144static d_kqfilter_t tunkqfilter; 145 146static int tunkqread(struct knote *, long); 147static int tunkqwrite(struct knote *, long); 148static void tunkqdetach(struct knote *); 149 150static struct filterops tun_read_filterops = { 151 .f_isfd = 1, 152 .f_attach = NULL, 153 .f_detach = tunkqdetach, 154 .f_event = tunkqread, 155}; 156 157static struct filterops tun_write_filterops = { 158 .f_isfd = 1, 159 .f_attach = NULL, 160 .f_detach = tunkqdetach, 161 .f_event = tunkqwrite, 162}; 163 164static struct cdevsw tun_cdevsw = { 165 .d_version = D_VERSION, 166 .d_flags = D_PSEUDO | D_NEEDGIANT | D_NEEDMINOR, 167 .d_open = tunopen, 168 .d_close = tunclose, 169 .d_read = tunread, 170 .d_write = tunwrite, 171 .d_ioctl = tunioctl, 172 .d_poll = tunpoll, 173 .d_kqfilter = tunkqfilter, 174 .d_name = TUNNAME, 175}; 176 177static int 178tun_clone_create(struct if_clone *ifc, int unit, caddr_t params) 179{ 180 struct cdev *dev; 181 int i; 182 183 /* find any existing device, or allocate new unit number */ 184 i = clone_create(&tunclones, &tun_cdevsw, &unit, &dev, 0); 185 if (i) { 186 /* No preexisting struct cdev *, create one */ 187 dev = make_dev(&tun_cdevsw, unit, 188 UID_UUCP, GID_DIALER, 0600, "%s%d", ifc->ifc_name, unit); 189 if (dev != NULL) { 190 dev_ref(dev); 191 dev->si_flags |= SI_CHEAPCLONE; 192 } 193 } 194 tuncreate(ifc->ifc_name, dev); 195 196 return (0); 197} 198 199static void 200tunclone(void *arg, struct ucred *cred, char *name, int namelen, 201 struct cdev **dev) 202{ 203 char devname[SPECNAMELEN + 1]; 204 int u, i, append_unit; 205 206 if (*dev != NULL) 207 return; 208 209 /* 210 * If tun cloning is enabled, only the superuser can create an 211 * interface. 212 */ 213 if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0) 214 return; 215 216 if (strcmp(name, TUNNAME) == 0) { 217 u = -1; 218 } else if (dev_stdclone(name, NULL, TUNNAME, &u) != 1) 219 return; /* Don't recognise the name */ 220 if (u != -1 && u > IF_MAXUNIT) 221 return; /* Unit number too high */ 222 223 if (u == -1) 224 append_unit = 1; 225 else 226 append_unit = 0; 227 228 CURVNET_SET(TD_TO_VNET(curthread)); 229 /* find any existing device, or allocate new unit number */ 230 i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0); 231 if (i) { 232 if (append_unit) { 233 namelen = snprintf(devname, sizeof(devname), "%s%d", name, 234 u); 235 name = devname; 236 } 237 /* No preexisting struct cdev *, create one */ 238 *dev = make_dev(&tun_cdevsw, u, 239 UID_UUCP, GID_DIALER, 0600, "%s", name); 240 if (*dev != NULL) { 241 dev_ref(*dev); 242 (*dev)->si_flags |= SI_CHEAPCLONE; 243 } 244 } 245 246 if_clone_create(name, namelen, NULL); 247 CURVNET_RESTORE(); 248} 249 250static void 251tun_destroy(struct tun_softc *tp) 252{ 253 struct cdev *dev; 254 255 /* Unlocked read. */ 256 KASSERT((tp->tun_flags & TUN_OPEN) == 0, 257 ("tununits is out of sync - unit %d", TUN2IFP(tp)->if_dunit)); 258 259 CURVNET_SET(TUN2IFP(tp)->if_vnet); 260 dev = tp->tun_dev; 261 bpfdetach(TUN2IFP(tp)); 262 if_detach(TUN2IFP(tp)); 263 if_free(TUN2IFP(tp)); 264 destroy_dev(dev); 265 knlist_destroy(&tp->tun_rsel.si_note); 266 mtx_destroy(&tp->tun_mtx); 267 free(tp, M_TUN); 268 CURVNET_RESTORE(); 269} 270 271static void 272tun_clone_destroy(struct ifnet *ifp) 273{ 274 struct tun_softc *tp = ifp->if_softc; 275 276 mtx_lock(&tunmtx); 277 TAILQ_REMOVE(&tunhead, tp, tun_list); 278 mtx_unlock(&tunmtx); 279 tun_destroy(tp); 280} 281 282static int 283tunmodevent(module_t mod, int type, void *data) 284{ 285 static eventhandler_tag tag; 286 struct tun_softc *tp; 287 288 switch (type) { 289 case MOD_LOAD: 290 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF); 291 clone_setup(&tunclones); 292 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000); 293 if (tag == NULL) 294 return (ENOMEM); 295 if_clone_attach(&tun_cloner); 296 break; 297 case MOD_UNLOAD: 298 if_clone_detach(&tun_cloner); 299 EVENTHANDLER_DEREGISTER(dev_clone, tag); 300 301 mtx_lock(&tunmtx); 302 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) { 303 TAILQ_REMOVE(&tunhead, tp, tun_list); 304 mtx_unlock(&tunmtx); 305 tun_destroy(tp); 306 mtx_lock(&tunmtx); 307 } 308 mtx_unlock(&tunmtx); 309 clone_cleanup(&tunclones); 310 mtx_destroy(&tunmtx); 311 break; 312 default: 313 return EOPNOTSUPP; 314 } 315 return 0; 316} 317 318static moduledata_t tun_mod = { 319 "if_tun", 320 tunmodevent, 321 0 322}; 323 324DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 325 326static void 327tunstart(struct ifnet *ifp) 328{ 329 struct tun_softc *tp = ifp->if_softc; 330 struct mbuf *m; 331 332 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname); 333 if (ALTQ_IS_ENABLED(&ifp->if_snd)) { 334 IFQ_LOCK(&ifp->if_snd); 335 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 336 if (m == NULL) { 337 IFQ_UNLOCK(&ifp->if_snd); 338 return; 339 } 340 IFQ_UNLOCK(&ifp->if_snd); 341 } 342 343 mtx_lock(&tp->tun_mtx); 344 if (tp->tun_flags & TUN_RWAIT) { 345 tp->tun_flags &= ~TUN_RWAIT; 346 wakeup(tp); 347 } 348 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) { 349 mtx_unlock(&tp->tun_mtx); 350 pgsigio(&tp->tun_sigio, SIGIO, 0); 351 } else 352 mtx_unlock(&tp->tun_mtx); 353 selwakeuppri(&tp->tun_rsel, PZERO + 1); 354 KNOTE_UNLOCKED(&tp->tun_rsel.si_note, 0); 355} 356 357/* XXX: should return an error code so it can fail. */ 358static void 359tuncreate(const char *name, struct cdev *dev) 360{ 361 struct tun_softc *sc; 362 struct ifnet *ifp; 363 364 dev->si_flags &= ~SI_CHEAPCLONE; 365 366 sc = malloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO); 367 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF); 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(&sc->tun_rsel.si_note, NULL, NULL, NULL, NULL); 389 390 if_attach(ifp); 391 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 392 dev->si_drv1 = sc; 393 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n", 394 ifp->if_xname, dev2unit(dev)); 395} 396 397static int 398tunopen(struct cdev *dev, int flag, int mode, struct thread *td) 399{ 400 struct ifnet *ifp; 401 struct tun_softc *tp; 402 403 /* 404 * XXXRW: Non-atomic test and set of dev->si_drv1 requires 405 * synchronization. 406 */ 407 tp = dev->si_drv1; 408 if (!tp) { 409 tuncreate(TUNNAME, dev); 410 tp = dev->si_drv1; 411 } 412 413 /* 414 * XXXRW: This use of tun_pid is subject to error due to the 415 * fact that a reference to the tunnel can live beyond the 416 * death of the process that created it. Can we replace this 417 * with a simple busy flag? 418 */ 419 mtx_lock(&tp->tun_mtx); 420 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) { 421 mtx_unlock(&tp->tun_mtx); 422 return (EBUSY); 423 } 424 tp->tun_pid = td->td_proc->p_pid; 425 426 tp->tun_flags |= TUN_OPEN; 427 mtx_unlock(&tp->tun_mtx); 428 ifp = TUN2IFP(tp); 429 TUNDEBUG(ifp, "open\n"); 430 431 return (0); 432} 433 434/* 435 * tunclose - close the device - mark i/f down & delete 436 * routing info 437 */ 438static int 439tunclose(struct cdev *dev, int foo, int bar, struct thread *td) 440{ 441 struct tun_softc *tp; 442 struct ifnet *ifp; 443 int s; 444 445 tp = dev->si_drv1; 446 ifp = TUN2IFP(tp); 447 448 mtx_lock(&tp->tun_mtx); 449 tp->tun_flags &= ~TUN_OPEN; 450 tp->tun_pid = 0; 451 452 /* 453 * junk all pending output 454 */ 455 CURVNET_SET(ifp->if_vnet); 456 s = splimp(); 457 IFQ_PURGE(&ifp->if_snd); 458 splx(s); 459 mtx_unlock(&tp->tun_mtx); 460 461 if (ifp->if_flags & IFF_UP) { 462 s = splimp(); 463 if_down(ifp); 464 splx(s); 465 } 466 467 /* Delete all addresses and routes which reference this interface. */ 468 if (ifp->if_drv_flags & IFF_DRV_RUNNING) { 469 struct ifaddr *ifa; 470 471 s = splimp(); 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 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 483 splx(s); 484 } 485 CURVNET_RESTORE(); 486 487 funsetown(&tp->tun_sigio); 488 selwakeuppri(&tp->tun_rsel, PZERO + 1); 489 KNOTE_UNLOCKED(&tp->tun_rsel.si_note, 0); 490 TUNDEBUG (ifp, "closed\n"); 491 return (0); 492} 493 494static int 495tuninit(struct ifnet *ifp) 496{ 497 struct tun_softc *tp = ifp->if_softc; 498 struct ifaddr *ifa; 499 int error = 0; 500 501 TUNDEBUG(ifp, "tuninit\n"); 502 503 ifp->if_flags |= IFF_UP; 504 ifp->if_drv_flags |= IFF_DRV_RUNNING; 505 getmicrotime(&ifp->if_lastchange); 506 507#ifdef INET 508 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 509 if (ifa->ifa_addr->sa_family == AF_INET) { 510 struct sockaddr_in *si; 511 512 si = (struct sockaddr_in *)ifa->ifa_addr; 513 mtx_lock(&tp->tun_mtx); 514 if (si->sin_addr.s_addr) 515 tp->tun_flags |= TUN_IASET; 516 517 si = (struct sockaddr_in *)ifa->ifa_dstaddr; 518 if (si && si->sin_addr.s_addr) 519 tp->tun_flags |= TUN_DSTADDR; 520 mtx_unlock(&tp->tun_mtx); 521 } 522 } 523#endif 524 return (error); 525} 526 527/* 528 * Process an ioctl request. 529 */ 530static int 531tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 532{ 533 struct ifreq *ifr = (struct ifreq *)data; 534 struct tun_softc *tp = ifp->if_softc; 535 struct ifstat *ifs; 536 int error = 0, s; 537 538 s = splimp(); 539 switch(cmd) { 540 case SIOCGIFSTATUS: 541 ifs = (struct ifstat *)data; 542 mtx_lock(&tp->tun_mtx); 543 if (tp->tun_pid) 544 sprintf(ifs->ascii + strlen(ifs->ascii), 545 "\tOpened by PID %d\n", tp->tun_pid); 546 mtx_unlock(&tp->tun_mtx); 547 break; 548 case SIOCSIFADDR: 549 error = tuninit(ifp); 550 TUNDEBUG(ifp, "address set, error=%d\n", error); 551 break; 552 case SIOCSIFDSTADDR: 553 error = tuninit(ifp); 554 TUNDEBUG(ifp, "destination address set, error=%d\n", error); 555 break; 556 case SIOCSIFMTU: 557 ifp->if_mtu = ifr->ifr_mtu; 558 TUNDEBUG(ifp, "mtu set\n"); 559 break; 560 case SIOCSIFFLAGS: 561 case SIOCADDMULTI: 562 case SIOCDELMULTI: 563 break; 564 default: 565 error = EINVAL; 566 } 567 splx(s); 568 return (error); 569} 570 571/* 572 * tunoutput - queue packets from higher level ready to put out. 573 */ 574static int 575tunoutput( 576 struct ifnet *ifp, 577 struct mbuf *m0, 578 struct sockaddr *dst, 579 struct rtentry *rt) 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 IFQ_HANDOFF(ifp, m0, error); 659 if (error) { 660 ifp->if_collisions++; 661 return (ENOBUFS); 662 } 663 ifp->if_opackets++; 664 return (0); 665} 666 667/* 668 * the cdevsw interface is now pretty minimal. 669 */ 670static int 671tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) 672{ 673 int s; 674 int error; 675 struct tun_softc *tp = dev->si_drv1; 676 struct tuninfo *tunp; 677 678 switch (cmd) { 679 case TUNSIFINFO: 680 tunp = (struct tuninfo *)data; 681 if (tunp->mtu < IF_MINMTU) 682 return (EINVAL); 683 if (TUN2IFP(tp)->if_mtu != tunp->mtu) { 684 error = priv_check(td, PRIV_NET_SETIFMTU); 685 if (error) 686 return (error); 687 } 688 TUN2IFP(tp)->if_mtu = tunp->mtu; 689 TUN2IFP(tp)->if_type = tunp->type; 690 TUN2IFP(tp)->if_baudrate = tunp->baudrate; 691 break; 692 case TUNGIFINFO: 693 tunp = (struct tuninfo *)data; 694 tunp->mtu = TUN2IFP(tp)->if_mtu; 695 tunp->type = TUN2IFP(tp)->if_type; 696 tunp->baudrate = TUN2IFP(tp)->if_baudrate; 697 break; 698 case TUNSDEBUG: 699 tundebug = *(int *)data; 700 break; 701 case TUNGDEBUG: 702 *(int *)data = tundebug; 703 break; 704 case TUNSLMODE: 705 mtx_lock(&tp->tun_mtx); 706 if (*(int *)data) { 707 tp->tun_flags |= TUN_LMODE; 708 tp->tun_flags &= ~TUN_IFHEAD; 709 } else 710 tp->tun_flags &= ~TUN_LMODE; 711 mtx_unlock(&tp->tun_mtx); 712 break; 713 case TUNSIFHEAD: 714 mtx_lock(&tp->tun_mtx); 715 if (*(int *)data) { 716 tp->tun_flags |= TUN_IFHEAD; 717 tp->tun_flags &= ~TUN_LMODE; 718 } else 719 tp->tun_flags &= ~TUN_IFHEAD; 720 mtx_unlock(&tp->tun_mtx); 721 break; 722 case TUNGIFHEAD: 723 /* Could be unlocked read? */ 724 mtx_lock(&tp->tun_mtx); 725 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 726 mtx_unlock(&tp->tun_mtx); 727 break; 728 case TUNSIFMODE: 729 /* deny this if UP */ 730 if (TUN2IFP(tp)->if_flags & IFF_UP) 731 return(EBUSY); 732 733 switch (*(int *)data & ~IFF_MULTICAST) { 734 case IFF_POINTOPOINT: 735 case IFF_BROADCAST: 736 TUN2IFP(tp)->if_flags &= 737 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 738 TUN2IFP(tp)->if_flags |= *(int *)data; 739 break; 740 default: 741 return(EINVAL); 742 } 743 break; 744 case TUNSIFPID: 745 mtx_lock(&tp->tun_mtx); 746 tp->tun_pid = curthread->td_proc->p_pid; 747 mtx_unlock(&tp->tun_mtx); 748 break; 749 case FIONBIO: 750 break; 751 case FIOASYNC: 752 mtx_lock(&tp->tun_mtx); 753 if (*(int *)data) 754 tp->tun_flags |= TUN_ASYNC; 755 else 756 tp->tun_flags &= ~TUN_ASYNC; 757 mtx_unlock(&tp->tun_mtx); 758 break; 759 case FIONREAD: 760 s = splimp(); 761 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) { 762 struct mbuf *mb; 763 IFQ_LOCK(&TUN2IFP(tp)->if_snd); 764 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb); 765 for( *(int *)data = 0; mb != 0; mb = mb->m_next) 766 *(int *)data += mb->m_len; 767 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd); 768 } else 769 *(int *)data = 0; 770 splx(s); 771 break; 772 case FIOSETOWN: 773 return (fsetown(*(int *)data, &tp->tun_sigio)); 774 775 case FIOGETOWN: 776 *(int *)data = fgetown(&tp->tun_sigio); 777 return (0); 778 779 /* This is deprecated, FIOSETOWN should be used instead. */ 780 case TIOCSPGRP: 781 return (fsetown(-(*(int *)data), &tp->tun_sigio)); 782 783 /* This is deprecated, FIOGETOWN should be used instead. */ 784 case TIOCGPGRP: 785 *(int *)data = -fgetown(&tp->tun_sigio); 786 return (0); 787 788 default: 789 return (ENOTTY); 790 } 791 return (0); 792} 793 794/* 795 * The cdevsw read interface - reads a packet at a time, or at 796 * least as much of a packet as can be read. 797 */ 798static int 799tunread(struct cdev *dev, struct uio *uio, int flag) 800{ 801 struct tun_softc *tp = dev->si_drv1; 802 struct ifnet *ifp = TUN2IFP(tp); 803 struct mbuf *m; 804 int error=0, len, s; 805 806 TUNDEBUG (ifp, "read\n"); 807 mtx_lock(&tp->tun_mtx); 808 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 809 mtx_unlock(&tp->tun_mtx); 810 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 811 return (EHOSTDOWN); 812 } 813 814 tp->tun_flags &= ~TUN_RWAIT; 815 mtx_unlock(&tp->tun_mtx); 816 817 s = splimp(); 818 do { 819 IFQ_DEQUEUE(&ifp->if_snd, m); 820 if (m == NULL) { 821 if (flag & O_NONBLOCK) { 822 splx(s); 823 return (EWOULDBLOCK); 824 } 825 mtx_lock(&tp->tun_mtx); 826 tp->tun_flags |= TUN_RWAIT; 827 mtx_unlock(&tp->tun_mtx); 828 if ((error = tsleep(tp, PCATCH | (PZERO + 1), 829 "tunread", 0)) != 0) { 830 splx(s); 831 return (error); 832 } 833 } 834 } while (m == NULL); 835 splx(s); 836 837 while (m && uio->uio_resid > 0 && error == 0) { 838 len = min(uio->uio_resid, m->m_len); 839 if (len != 0) 840 error = uiomove(mtod(m, void *), len, uio); 841 m = m_free(m); 842 } 843 844 if (m) { 845 TUNDEBUG(ifp, "Dropping mbuf\n"); 846 m_freem(m); 847 } 848 return (error); 849} 850 851/* 852 * the cdevsw write interface - an atomic write is a packet - or else! 853 */ 854static int 855tunwrite(struct cdev *dev, struct uio *uio, int flag) 856{ 857 struct tun_softc *tp = dev->si_drv1; 858 struct ifnet *ifp = TUN2IFP(tp); 859 struct mbuf *m; 860 int error = 0; 861 uint32_t family; 862 int isr; 863 864 TUNDEBUG(ifp, "tunwrite\n"); 865 866 if ((ifp->if_flags & IFF_UP) != IFF_UP) 867 /* ignore silently */ 868 return (0); 869 870 if (uio->uio_resid == 0) 871 return (0); 872 873 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) { 874 TUNDEBUG(ifp, "len=%d!\n", uio->uio_resid); 875 return (EIO); 876 } 877 878 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) { 879 ifp->if_ierrors++; 880 return (error); 881 } 882 883 m->m_pkthdr.rcvif = ifp; 884#ifdef MAC 885 mac_ifnet_create_mbuf(ifp, m); 886#endif 887 888 /* Could be unlocked read? */ 889 mtx_lock(&tp->tun_mtx); 890 if (tp->tun_flags & TUN_IFHEAD) { 891 mtx_unlock(&tp->tun_mtx); 892 if (m->m_len < sizeof(family) && 893 (m = m_pullup(m, sizeof(family))) == NULL) 894 return (ENOBUFS); 895 family = ntohl(*mtod(m, u_int32_t *)); 896 m_adj(m, sizeof(family)); 897 } else { 898 mtx_unlock(&tp->tun_mtx); 899 family = AF_INET; 900 } 901 902 BPF_MTAP2(ifp, &family, sizeof(family), m); 903 904 switch (family) { 905#ifdef INET 906 case AF_INET: 907 isr = NETISR_IP; 908 break; 909#endif 910#ifdef INET6 911 case AF_INET6: 912 isr = NETISR_IPV6; 913 break; 914#endif 915#ifdef IPX 916 case AF_IPX: 917 isr = NETISR_IPX; 918 break; 919#endif 920#ifdef NETATALK 921 case AF_APPLETALK: 922 isr = NETISR_ATALK2; 923 break; 924#endif 925 default: 926 m_freem(m); 927 return (EAFNOSUPPORT); 928 } 929 /* First chunk of an mbuf contains good junk */ 930 if (harvest.point_to_point) 931 random_harvest(m, 16, 3, 0, RANDOM_NET); 932 ifp->if_ibytes += m->m_pkthdr.len; 933 ifp->if_ipackets++; 934 CURVNET_SET(ifp->if_vnet); 935 netisr_dispatch(isr, m); 936 CURVNET_RESTORE(); 937 return (0); 938} 939 940/* 941 * tunpoll - the poll interface, this is only useful on reads 942 * really. The write detect always returns true, write never blocks 943 * anyway, it either accepts the packet or drops it. 944 */ 945static int 946tunpoll(struct cdev *dev, int events, struct thread *td) 947{ 948 int s; 949 struct tun_softc *tp = dev->si_drv1; 950 struct ifnet *ifp = TUN2IFP(tp); 951 int revents = 0; 952 struct mbuf *m; 953 954 s = splimp(); 955 TUNDEBUG(ifp, "tunpoll\n"); 956 957 if (events & (POLLIN | POLLRDNORM)) { 958 IFQ_LOCK(&ifp->if_snd); 959 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 960 if (m != NULL) { 961 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len); 962 revents |= events & (POLLIN | POLLRDNORM); 963 } else { 964 TUNDEBUG(ifp, "tunpoll waiting\n"); 965 selrecord(td, &tp->tun_rsel); 966 } 967 IFQ_UNLOCK(&ifp->if_snd); 968 } 969 if (events & (POLLOUT | POLLWRNORM)) 970 revents |= events & (POLLOUT | POLLWRNORM); 971 972 splx(s); 973 return (revents); 974} 975 976/* 977 * tunkqfilter - support for the kevent() system call. 978 */ 979static int 980tunkqfilter(struct cdev *dev, struct knote *kn) 981{ 982 int s; 983 struct tun_softc *tp = dev->si_drv1; 984 struct ifnet *ifp = TUN2IFP(tp); 985 986 s = splimp(); 987 switch(kn->kn_filter) { 988 case EVFILT_READ: 989 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n", 990 ifp->if_xname, dev2unit(dev)); 991 kn->kn_fop = &tun_read_filterops; 992 break; 993 994 case EVFILT_WRITE: 995 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n", 996 ifp->if_xname, dev2unit(dev)); 997 kn->kn_fop = &tun_write_filterops; 998 break; 999 1000 default: 1001 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n", 1002 ifp->if_xname, dev2unit(dev)); 1003 splx(s); 1004 return(EINVAL); 1005 } 1006 splx(s); 1007 1008 kn->kn_hook = (caddr_t) dev; 1009 knlist_add(&tp->tun_rsel.si_note, kn, 0); 1010 1011 return (0); 1012} 1013 1014/* 1015 * Return true of there is data in the interface queue. 1016 */ 1017static int 1018tunkqread(struct knote *kn, long hint) 1019{ 1020 int ret, s; 1021 struct cdev *dev = (struct cdev *)(kn->kn_hook); 1022 struct tun_softc *tp = dev->si_drv1; 1023 struct ifnet *ifp = TUN2IFP(tp); 1024 1025 s = splimp(); 1026 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) { 1027 TUNDEBUG(ifp, 1028 "%s have data in the queue. Len = %d, minor = %#x\n", 1029 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev)); 1030 ret = 1; 1031 } else { 1032 TUNDEBUG(ifp, 1033 "%s waiting for data, minor = %#x\n", ifp->if_xname, 1034 dev2unit(dev)); 1035 ret = 0; 1036 } 1037 splx(s); 1038 1039 return (ret); 1040} 1041 1042/* 1043 * Always can write, always return MTU in kn->data. 1044 */ 1045static int 1046tunkqwrite(struct knote *kn, long hint) 1047{ 1048 int s; 1049 struct tun_softc *tp = ((struct cdev *)kn->kn_hook)->si_drv1; 1050 struct ifnet *ifp = TUN2IFP(tp); 1051 1052 s = splimp(); 1053 kn->kn_data = ifp->if_mtu; 1054 splx(s); 1055 1056 return (1); 1057} 1058 1059static void 1060tunkqdetach(struct knote *kn) 1061{ 1062 struct tun_softc *tp = ((struct cdev *)kn->kn_hook)->si_drv1; 1063 1064 knlist_remove(&tp->tun_rsel.si_note, kn, 0); 1065} 1066