Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/net/if_tun.c
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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: releng/7.4/sys/net/if_tun.c 213895 2010-10-15 15:06:32Z bz $ 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 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 #ifdef INET 53 #include <netinet/in.h> 54 #endif 55 #include <net/bpf.h> 56 #include <net/if_tun.h> 57 58 #include <sys/queue.h> 59 #include <sys/condvar.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 */ 68 struct 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 struct cv tun_cv; /* protect against ref'd dev destroy */ 97 }; 98 #define TUN2IFP(sc) ((sc)->tun_ifp) 99 100 #define TUNDEBUG if (tundebug) if_printf 101 #define TUNNAME "tun" 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 */ 108 static struct mtx tunmtx; 109 static MALLOC_DEFINE(M_TUN, TUNNAME, "Tunnel Interface"); 110 static int tundebug = 0; 111 static int tundclone = 1; 112 static struct clonedevs *tunclones; 113 static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead); 114 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, ""); 115 116 SYSCTL_DECL(_net_link); 117 SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0, 118 "IP tunnel software network interface."); 119 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tundclone, 0, 120 "Enable legacy devfs interface creation."); 121 122 TUNABLE_INT("net.link.tun.devfs_cloning", &tundclone); 123 124 static void tunclone(void *arg, struct ucred *cred, char *name, 125 int namelen, struct cdev **dev); 126 static void tuncreate(const char *name, struct cdev *dev); 127 static int tunifioctl(struct ifnet *, u_long, caddr_t); 128 static int tuninit(struct ifnet *); 129 static int tunmodevent(module_t, int, void *); 130 static int tunoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 131 struct rtentry *rt); 132 static void tunstart(struct ifnet *); 133 134 static int tun_clone_create(struct if_clone *, int, caddr_t); 135 static void tun_clone_destroy(struct ifnet *); 136 137 IFC_SIMPLE_DECLARE(tun, 0); 138 139 static d_open_t tunopen; 140 static d_close_t tunclose; 141 static d_read_t tunread; 142 static d_write_t tunwrite; 143 static d_ioctl_t tunioctl; 144 static d_poll_t tunpoll; 145 static d_kqfilter_t tunkqfilter; 146 147 static int tunkqread(struct knote *, long); 148 static int tunkqwrite(struct knote *, long); 149 static void tunkqdetach(struct knote *); 150 151 static struct filterops tun_read_filterops = { 152 .f_isfd = 1, 153 .f_attach = NULL, 154 .f_detach = tunkqdetach, 155 .f_event = tunkqread, 156 }; 157 158 static struct filterops tun_write_filterops = { 159 .f_isfd = 1, 160 .f_attach = NULL, 161 .f_detach = tunkqdetach, 162 .f_event = tunkqwrite, 163 }; 164 165 static struct cdevsw tun_cdevsw = { 166 .d_version = D_VERSION, 167 .d_flags = D_PSEUDO, 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 }; 177 178 static int 179 tun_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, unit2minor(unit), 189 UID_UUCP, GID_DIALER, 0600, "%s%d", ifc->ifc_name, unit); 190 } 191 tuncreate(ifc->ifc_name, dev); 192 193 return (0); 194 } 195 196 static void 197 tunclone(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 /* find any existing device, or allocate new unit number */ 226 i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0); 227 if (i) { 228 if (append_unit) { 229 namelen = snprintf(devname, sizeof(devname), "%s%d", name, 230 u); 231 name = devname; 232 } 233 /* No preexisting struct cdev *, create one */ 234 *dev = make_dev_credf(MAKEDEV_REF, &tun_cdevsw, unit2minor(u), 235 cred, UID_UUCP, GID_DIALER, 0600, "%s", name); 236 } 237 238 if_clone_create(name, namelen, NULL); 239 } 240 241 static void 242 tun_destroy(struct tun_softc *tp) 243 { 244 struct cdev *dev; 245 246 /* Unlocked read. */ 247 mtx_lock(&tp->tun_mtx); 248 if ((tp->tun_flags & TUN_OPEN) != 0) 249 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx); 250 else 251 mtx_unlock(&tp->tun_mtx); 252 253 dev = tp->tun_dev; 254 bpfdetach(TUN2IFP(tp)); 255 if_detach(TUN2IFP(tp)); 256 if_free(TUN2IFP(tp)); 257 destroy_dev(dev); 258 knlist_destroy(&tp->tun_rsel.si_note); 259 mtx_destroy(&tp->tun_mtx); 260 cv_destroy(&tp->tun_cv); 261 free(tp, M_TUN); 262 } 263 264 static void 265 tun_clone_destroy(struct ifnet *ifp) 266 { 267 struct tun_softc *tp = ifp->if_softc; 268 269 mtx_lock(&tunmtx); 270 TAILQ_REMOVE(&tunhead, tp, tun_list); 271 mtx_unlock(&tunmtx); 272 tun_destroy(tp); 273 } 274 275 static int 276 tunmodevent(module_t mod, int type, void *data) 277 { 278 static eventhandler_tag tag; 279 struct tun_softc *tp; 280 281 switch (type) { 282 case MOD_LOAD: 283 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF); 284 clone_setup(&tunclones); 285 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000); 286 if (tag == NULL) 287 return (ENOMEM); 288 if_clone_attach(&tun_cloner); 289 break; 290 case MOD_UNLOAD: 291 if_clone_detach(&tun_cloner); 292 EVENTHANDLER_DEREGISTER(dev_clone, tag); 293 drain_dev_clone_events(); 294 295 mtx_lock(&tunmtx); 296 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) { 297 TAILQ_REMOVE(&tunhead, tp, tun_list); 298 mtx_unlock(&tunmtx); 299 tun_destroy(tp); 300 mtx_lock(&tunmtx); 301 } 302 mtx_unlock(&tunmtx); 303 clone_cleanup(&tunclones); 304 mtx_destroy(&tunmtx); 305 break; 306 default: 307 return EOPNOTSUPP; 308 } 309 return 0; 310 } 311 312 static moduledata_t tun_mod = { 313 "if_tun", 314 tunmodevent, 315 0 316 }; 317 318 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 319 320 static void 321 tunstart(struct ifnet *ifp) 322 { 323 struct tun_softc *tp = ifp->if_softc; 324 struct mbuf *m; 325 326 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname); 327 if (ALTQ_IS_ENABLED(&ifp->if_snd)) { 328 IFQ_LOCK(&ifp->if_snd); 329 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 330 if (m == NULL) { 331 IFQ_UNLOCK(&ifp->if_snd); 332 return; 333 } 334 IFQ_UNLOCK(&ifp->if_snd); 335 } 336 337 mtx_lock(&tp->tun_mtx); 338 if (tp->tun_flags & TUN_RWAIT) { 339 tp->tun_flags &= ~TUN_RWAIT; 340 wakeup(tp); 341 } 342 selwakeuppri(&tp->tun_rsel, PZERO + 1); 343 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0); 344 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) { 345 mtx_unlock(&tp->tun_mtx); 346 pgsigio(&tp->tun_sigio, SIGIO, 0); 347 } else 348 mtx_unlock(&tp->tun_mtx); 349 } 350 351 /* XXX: should return an error code so it can fail. */ 352 static void 353 tuncreate(const char *name, struct cdev *dev) 354 { 355 struct tun_softc *sc; 356 struct ifnet *ifp; 357 358 dev->si_flags &= ~SI_CHEAPCLONE; 359 360 MALLOC(sc, struct tun_softc *, sizeof(*sc), M_TUN, M_WAITOK | M_ZERO); 361 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF); 362 cv_init(&sc->tun_cv, "tun_condvar"); 363 sc->tun_flags = TUN_INITED; 364 sc->tun_dev = dev; 365 mtx_lock(&tunmtx); 366 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list); 367 mtx_unlock(&tunmtx); 368 369 ifp = sc->tun_ifp = if_alloc(IFT_PPP); 370 if (ifp == NULL) 371 panic("%s%d: failed to if_alloc() interface.\n", 372 name, dev2unit(dev)); 373 if_initname(ifp, name, dev2unit(dev)); 374 ifp->if_mtu = TUNMTU; 375 ifp->if_ioctl = tunifioctl; 376 ifp->if_output = tunoutput; 377 ifp->if_start = tunstart; 378 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 379 ifp->if_softc = sc; 380 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen); 381 ifp->if_snd.ifq_drv_maxlen = 0; 382 IFQ_SET_READY(&ifp->if_snd); 383 knlist_init_mtx(&sc->tun_rsel.si_note, &sc->tun_mtx); 384 385 if_attach(ifp); 386 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 387 dev->si_drv1 = sc; 388 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n", 389 ifp->if_xname, minor(dev)); 390 } 391 392 static int 393 tunopen(struct cdev *dev, int flag, int mode, struct thread *td) 394 { 395 struct ifnet *ifp; 396 struct tun_softc *tp; 397 398 /* 399 * XXXRW: Non-atomic test and set of dev->si_drv1 requires 400 * synchronization. 401 */ 402 tp = dev->si_drv1; 403 if (!tp) { 404 tuncreate(TUNNAME, dev); 405 tp = dev->si_drv1; 406 } 407 408 /* 409 * XXXRW: This use of tun_pid is subject to error due to the 410 * fact that a reference to the tunnel can live beyond the 411 * death of the process that created it. Can we replace this 412 * with a simple busy flag? 413 */ 414 mtx_lock(&tp->tun_mtx); 415 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) { 416 mtx_unlock(&tp->tun_mtx); 417 return (EBUSY); 418 } 419 tp->tun_pid = td->td_proc->p_pid; 420 421 tp->tun_flags |= TUN_OPEN; 422 ifp = TUN2IFP(tp); 423 if_link_state_change(ifp, LINK_STATE_UP); 424 TUNDEBUG(ifp, "open\n"); 425 mtx_unlock(&tp->tun_mtx); 426 427 return (0); 428 } 429 430 /* 431 * tunclose - close the device - mark i/f down & delete 432 * routing info 433 */ 434 static int 435 tunclose(struct cdev *dev, int foo, int bar, struct thread *td) 436 { 437 struct tun_softc *tp; 438 struct ifnet *ifp; 439 440 tp = dev->si_drv1; 441 ifp = TUN2IFP(tp); 442 443 mtx_lock(&tp->tun_mtx); 444 tp->tun_flags &= ~TUN_OPEN; 445 tp->tun_pid = 0; 446 447 /* 448 * junk all pending output 449 */ 450 IFQ_PURGE(&ifp->if_snd); 451 452 if (ifp->if_flags & IFF_UP) { 453 mtx_unlock(&tp->tun_mtx); 454 if_down(ifp); 455 mtx_lock(&tp->tun_mtx); 456 } 457 458 /* Delete all addresses and routes which reference this interface. */ 459 if (ifp->if_drv_flags & IFF_DRV_RUNNING) { 460 struct ifaddr *ifa; 461 462 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 463 mtx_unlock(&tp->tun_mtx); 464 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 465 /* deal w/IPv4 PtP destination; unlocked read */ 466 if (ifa->ifa_addr->sa_family == AF_INET) { 467 rtinit(ifa, (int)RTM_DELETE, 468 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0); 469 } else { 470 rtinit(ifa, (int)RTM_DELETE, 0); 471 } 472 } 473 if_purgeaddrs(ifp); 474 mtx_lock(&tp->tun_mtx); 475 } 476 if_link_state_change(ifp, LINK_STATE_DOWN); 477 478 funsetown(&tp->tun_sigio); 479 selwakeuppri(&tp->tun_rsel, PZERO + 1); 480 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0); 481 TUNDEBUG (ifp, "closed\n"); 482 483 cv_broadcast(&tp->tun_cv); 484 mtx_unlock(&tp->tun_mtx); 485 return (0); 486 } 487 488 static int 489 tuninit(struct ifnet *ifp) 490 { 491 struct tun_softc *tp = ifp->if_softc; 492 #ifdef INET 493 struct ifaddr *ifa; 494 #endif 495 int error = 0; 496 497 TUNDEBUG(ifp, "tuninit\n"); 498 499 mtx_lock(&tp->tun_mtx); 500 ifp->if_flags |= IFF_UP; 501 ifp->if_drv_flags |= IFF_DRV_RUNNING; 502 getmicrotime(&ifp->if_lastchange); 503 504 #ifdef INET 505 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 506 if (ifa->ifa_addr->sa_family == AF_INET) { 507 struct sockaddr_in *si; 508 509 si = (struct sockaddr_in *)ifa->ifa_addr; 510 if (si->sin_addr.s_addr) 511 tp->tun_flags |= TUN_IASET; 512 513 si = (struct sockaddr_in *)ifa->ifa_dstaddr; 514 if (si && si->sin_addr.s_addr) 515 tp->tun_flags |= TUN_DSTADDR; 516 } 517 } 518 #endif 519 mtx_unlock(&tp->tun_mtx); 520 return (error); 521 } 522 523 /* 524 * Process an ioctl request. 525 */ 526 static int 527 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 528 { 529 struct ifreq *ifr = (struct ifreq *)data; 530 struct tun_softc *tp = ifp->if_softc; 531 struct ifstat *ifs; 532 int error = 0; 533 534 switch(cmd) { 535 case SIOCGIFSTATUS: 536 ifs = (struct ifstat *)data; 537 mtx_lock(&tp->tun_mtx); 538 if (tp->tun_pid) 539 sprintf(ifs->ascii + strlen(ifs->ascii), 540 "\tOpened by PID %d\n", tp->tun_pid); 541 mtx_unlock(&tp->tun_mtx); 542 break; 543 case SIOCSIFADDR: 544 error = tuninit(ifp); 545 TUNDEBUG(ifp, "address set, error=%d\n", error); 546 break; 547 case SIOCSIFDSTADDR: 548 error = tuninit(ifp); 549 TUNDEBUG(ifp, "destination address set, error=%d\n", error); 550 break; 551 case SIOCSIFMTU: 552 ifp->if_mtu = ifr->ifr_mtu; 553 TUNDEBUG(ifp, "mtu set\n"); 554 break; 555 case SIOCSIFFLAGS: 556 case SIOCADDMULTI: 557 case SIOCDELMULTI: 558 break; 559 default: 560 error = EINVAL; 561 } 562 return (error); 563 } 564 565 /* 566 * tunoutput - queue packets from higher level ready to put out. 567 */ 568 static int 569 tunoutput( 570 struct ifnet *ifp, 571 struct mbuf *m0, 572 struct sockaddr *dst, 573 struct rtentry *rt) 574 { 575 struct tun_softc *tp = ifp->if_softc; 576 u_short cached_tun_flags; 577 int error; 578 u_int32_t af; 579 580 TUNDEBUG (ifp, "tunoutput\n"); 581 582 #ifdef MAC 583 error = mac_check_ifnet_transmit(ifp, m0); 584 if (error) { 585 m_freem(m0); 586 return (error); 587 } 588 #endif 589 590 /* Could be unlocked read? */ 591 mtx_lock(&tp->tun_mtx); 592 cached_tun_flags = tp->tun_flags; 593 mtx_unlock(&tp->tun_mtx); 594 if ((cached_tun_flags & TUN_READY) != TUN_READY) { 595 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 596 m_freem (m0); 597 return (EHOSTDOWN); 598 } 599 600 if ((ifp->if_flags & IFF_UP) != IFF_UP) { 601 m_freem (m0); 602 return (EHOSTDOWN); 603 } 604 605 /* BPF writes need to be handled specially. */ 606 if (dst->sa_family == AF_UNSPEC) { 607 bcopy(dst->sa_data, &af, sizeof(af)); 608 dst->sa_family = af; 609 } 610 611 if (bpf_peers_present(ifp->if_bpf)) { 612 af = dst->sa_family; 613 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0); 614 } 615 616 /* prepend sockaddr? this may abort if the mbuf allocation fails */ 617 if (cached_tun_flags & TUN_LMODE) { 618 /* allocate space for sockaddr */ 619 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 620 621 /* if allocation failed drop packet */ 622 if (m0 == NULL) { 623 ifp->if_iqdrops++; 624 ifp->if_oerrors++; 625 return (ENOBUFS); 626 } else { 627 bcopy(dst, m0->m_data, dst->sa_len); 628 } 629 } 630 631 if (cached_tun_flags & TUN_IFHEAD) { 632 /* Prepend the address family */ 633 M_PREPEND(m0, 4, M_DONTWAIT); 634 635 /* if allocation failed drop packet */ 636 if (m0 == NULL) { 637 ifp->if_iqdrops++; 638 ifp->if_oerrors++; 639 return (ENOBUFS); 640 } else 641 *(u_int32_t *)m0->m_data = htonl(dst->sa_family); 642 } else { 643 #ifdef INET 644 if (dst->sa_family != AF_INET) 645 #endif 646 { 647 m_freem(m0); 648 return (EAFNOSUPPORT); 649 } 650 } 651 652 IFQ_HANDOFF(ifp, m0, error); 653 if (error) { 654 ifp->if_collisions++; 655 return (ENOBUFS); 656 } 657 ifp->if_opackets++; 658 return (0); 659 } 660 661 /* 662 * the cdevsw interface is now pretty minimal. 663 */ 664 static int 665 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) 666 { 667 int error; 668 struct tun_softc *tp = dev->si_drv1; 669 struct tuninfo *tunp; 670 671 switch (cmd) { 672 case TUNSIFINFO: 673 tunp = (struct tuninfo *)data; 674 if (tunp->mtu < IF_MINMTU) 675 return (EINVAL); 676 if (TUN2IFP(tp)->if_mtu != tunp->mtu) { 677 error = priv_check(td, PRIV_NET_SETIFMTU); 678 if (error) 679 return (error); 680 } 681 mtx_lock(&tp->tun_mtx); 682 TUN2IFP(tp)->if_mtu = tunp->mtu; 683 TUN2IFP(tp)->if_type = tunp->type; 684 TUN2IFP(tp)->if_baudrate = tunp->baudrate; 685 mtx_unlock(&tp->tun_mtx); 686 break; 687 case TUNGIFINFO: 688 tunp = (struct tuninfo *)data; 689 mtx_lock(&tp->tun_mtx); 690 tunp->mtu = TUN2IFP(tp)->if_mtu; 691 tunp->type = TUN2IFP(tp)->if_type; 692 tunp->baudrate = TUN2IFP(tp)->if_baudrate; 693 mtx_unlock(&tp->tun_mtx); 694 break; 695 case TUNSDEBUG: 696 tundebug = *(int *)data; 697 break; 698 case TUNGDEBUG: 699 *(int *)data = tundebug; 700 break; 701 case TUNSLMODE: 702 mtx_lock(&tp->tun_mtx); 703 if (*(int *)data) { 704 tp->tun_flags |= TUN_LMODE; 705 tp->tun_flags &= ~TUN_IFHEAD; 706 } else 707 tp->tun_flags &= ~TUN_LMODE; 708 mtx_unlock(&tp->tun_mtx); 709 break; 710 case TUNSIFHEAD: 711 mtx_lock(&tp->tun_mtx); 712 if (*(int *)data) { 713 tp->tun_flags |= TUN_IFHEAD; 714 tp->tun_flags &= ~TUN_LMODE; 715 } else 716 tp->tun_flags &= ~TUN_IFHEAD; 717 mtx_unlock(&tp->tun_mtx); 718 break; 719 case TUNGIFHEAD: 720 mtx_lock(&tp->tun_mtx); 721 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 722 mtx_unlock(&tp->tun_mtx); 723 break; 724 case TUNSIFMODE: 725 /* deny this if UP */ 726 if (TUN2IFP(tp)->if_flags & IFF_UP) 727 return(EBUSY); 728 729 switch (*(int *)data & ~IFF_MULTICAST) { 730 case IFF_POINTOPOINT: 731 case IFF_BROADCAST: 732 mtx_lock(&tp->tun_mtx); 733 TUN2IFP(tp)->if_flags &= 734 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 735 TUN2IFP(tp)->if_flags |= *(int *)data; 736 mtx_unlock(&tp->tun_mtx); 737 break; 738 default: 739 return(EINVAL); 740 } 741 break; 742 case TUNSIFPID: 743 mtx_lock(&tp->tun_mtx); 744 tp->tun_pid = curthread->td_proc->p_pid; 745 mtx_unlock(&tp->tun_mtx); 746 break; 747 case FIONBIO: 748 break; 749 case FIOASYNC: 750 mtx_lock(&tp->tun_mtx); 751 if (*(int *)data) 752 tp->tun_flags |= TUN_ASYNC; 753 else 754 tp->tun_flags &= ~TUN_ASYNC; 755 mtx_unlock(&tp->tun_mtx); 756 break; 757 case FIONREAD: 758 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) { 759 struct mbuf *mb; 760 IFQ_LOCK(&TUN2IFP(tp)->if_snd); 761 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb); 762 for (*(int *)data = 0; mb != NULL; mb = mb->m_next) 763 *(int *)data += mb->m_len; 764 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd); 765 } else 766 *(int *)data = 0; 767 break; 768 case FIOSETOWN: 769 return (fsetown(*(int *)data, &tp->tun_sigio)); 770 771 case FIOGETOWN: 772 *(int *)data = fgetown(&tp->tun_sigio); 773 return (0); 774 775 /* This is deprecated, FIOSETOWN should be used instead. */ 776 case TIOCSPGRP: 777 return (fsetown(-(*(int *)data), &tp->tun_sigio)); 778 779 /* This is deprecated, FIOGETOWN should be used instead. */ 780 case TIOCGPGRP: 781 *(int *)data = -fgetown(&tp->tun_sigio); 782 return (0); 783 784 default: 785 return (ENOTTY); 786 } 787 return (0); 788 } 789 790 /* 791 * The cdevsw read interface - reads a packet at a time, or at 792 * least as much of a packet as can be read. 793 */ 794 static int 795 tunread(struct cdev *dev, struct uio *uio, int flag) 796 { 797 struct tun_softc *tp = dev->si_drv1; 798 struct ifnet *ifp = TUN2IFP(tp); 799 struct mbuf *m; 800 int error=0, len; 801 802 TUNDEBUG (ifp, "read\n"); 803 mtx_lock(&tp->tun_mtx); 804 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 805 mtx_unlock(&tp->tun_mtx); 806 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 807 return (EHOSTDOWN); 808 } 809 810 tp->tun_flags &= ~TUN_RWAIT; 811 812 do { 813 IFQ_DEQUEUE(&ifp->if_snd, m); 814 if (m == NULL) { 815 if (flag & O_NONBLOCK) { 816 mtx_unlock(&tp->tun_mtx); 817 return (EWOULDBLOCK); 818 } 819 tp->tun_flags |= TUN_RWAIT; 820 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1), 821 "tunread", 0); 822 if (error != 0) { 823 mtx_unlock(&tp->tun_mtx); 824 return (error); 825 } 826 } 827 } while (m == NULL); 828 mtx_unlock(&tp->tun_mtx); 829 830 while (m && uio->uio_resid > 0 && error == 0) { 831 len = min(uio->uio_resid, m->m_len); 832 if (len != 0) 833 error = uiomove(mtod(m, void *), len, uio); 834 m = m_free(m); 835 } 836 837 if (m) { 838 TUNDEBUG(ifp, "Dropping mbuf\n"); 839 m_freem(m); 840 } 841 return (error); 842 } 843 844 /* 845 * the cdevsw write interface - an atomic write is a packet - or else! 846 */ 847 static int 848 tunwrite(struct cdev *dev, struct uio *uio, int flag) 849 { 850 struct tun_softc *tp = dev->si_drv1; 851 struct ifnet *ifp = TUN2IFP(tp); 852 struct mbuf *m; 853 int error = 0; 854 uint32_t family; 855 int isr; 856 857 TUNDEBUG(ifp, "tunwrite\n"); 858 859 if ((ifp->if_flags & IFF_UP) != IFF_UP) 860 /* ignore silently */ 861 return (0); 862 863 if (uio->uio_resid == 0) 864 return (0); 865 866 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) { 867 TUNDEBUG(ifp, "len=%d!\n", uio->uio_resid); 868 return (EIO); 869 } 870 871 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) { 872 ifp->if_ierrors++; 873 return (error); 874 } 875 876 m->m_pkthdr.rcvif = ifp; 877 #ifdef MAC 878 mac_create_mbuf_from_ifnet(ifp, m); 879 #endif 880 881 /* Could be unlocked read? */ 882 mtx_lock(&tp->tun_mtx); 883 if (tp->tun_flags & TUN_IFHEAD) { 884 mtx_unlock(&tp->tun_mtx); 885 if (m->m_len < sizeof(family) && 886 (m = m_pullup(m, sizeof(family))) == NULL) 887 return (ENOBUFS); 888 family = ntohl(*mtod(m, u_int32_t *)); 889 m_adj(m, sizeof(family)); 890 } else { 891 mtx_unlock(&tp->tun_mtx); 892 family = AF_INET; 893 } 894 895 BPF_MTAP2(ifp, &family, sizeof(family), m); 896 897 switch (family) { 898 #ifdef INET 899 case AF_INET: 900 isr = NETISR_IP; 901 break; 902 #endif 903 #ifdef INET6 904 case AF_INET6: 905 isr = NETISR_IPV6; 906 break; 907 #endif 908 #ifdef IPX 909 case AF_IPX: 910 isr = NETISR_IPX; 911 break; 912 #endif 913 #ifdef NETATALK 914 case AF_APPLETALK: 915 isr = NETISR_ATALK2; 916 break; 917 #endif 918 default: 919 m_freem(m); 920 return (EAFNOSUPPORT); 921 } 922 /* First chunk of an mbuf contains good junk */ 923 if (harvest.point_to_point) 924 random_harvest(m, 16, 3, 0, RANDOM_NET); 925 ifp->if_ibytes += m->m_pkthdr.len; 926 ifp->if_ipackets++; 927 netisr_dispatch(isr, m); 928 return (0); 929 } 930 931 /* 932 * tunpoll - the poll interface, this is only useful on reads 933 * really. The write detect always returns true, write never blocks 934 * anyway, it either accepts the packet or drops it. 935 */ 936 static int 937 tunpoll(struct cdev *dev, int events, struct thread *td) 938 { 939 struct tun_softc *tp = dev->si_drv1; 940 struct ifnet *ifp = TUN2IFP(tp); 941 int revents = 0; 942 struct mbuf *m; 943 944 TUNDEBUG(ifp, "tunpoll\n"); 945 946 if (events & (POLLIN | POLLRDNORM)) { 947 IFQ_LOCK(&ifp->if_snd); 948 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 949 if (m != NULL) { 950 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len); 951 revents |= events & (POLLIN | POLLRDNORM); 952 } else { 953 TUNDEBUG(ifp, "tunpoll waiting\n"); 954 selrecord(td, &tp->tun_rsel); 955 } 956 IFQ_UNLOCK(&ifp->if_snd); 957 } 958 if (events & (POLLOUT | POLLWRNORM)) 959 revents |= events & (POLLOUT | POLLWRNORM); 960 961 return (revents); 962 } 963 964 /* 965 * tunkqfilter - support for the kevent() system call. 966 */ 967 static int 968 tunkqfilter(struct cdev *dev, struct knote *kn) 969 { 970 struct tun_softc *tp = dev->si_drv1; 971 struct ifnet *ifp = TUN2IFP(tp); 972 973 switch(kn->kn_filter) { 974 case EVFILT_READ: 975 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n", 976 ifp->if_xname, minor(dev)); 977 kn->kn_fop = &tun_read_filterops; 978 break; 979 980 case EVFILT_WRITE: 981 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n", 982 ifp->if_xname, minor(dev)); 983 kn->kn_fop = &tun_write_filterops; 984 break; 985 986 default: 987 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n", 988 ifp->if_xname, minor(dev)); 989 return(EINVAL); 990 } 991 992 kn->kn_hook = tp; 993 knlist_add(&tp->tun_rsel.si_note, kn, 0); 994 995 return (0); 996 } 997 998 /* 999 * Return true of there is data in the interface queue. 1000 */ 1001 static int 1002 tunkqread(struct knote *kn, long hint) 1003 { 1004 int ret; 1005 struct tun_softc *tp = kn->kn_hook; 1006 struct cdev *dev = tp->tun_dev; 1007 struct ifnet *ifp = TUN2IFP(tp); 1008 1009 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) { 1010 TUNDEBUG(ifp, 1011 "%s have data in the queue. Len = %d, minor = %#x\n", 1012 ifp->if_xname, ifp->if_snd.ifq_len, minor(dev)); 1013 ret = 1; 1014 } else { 1015 TUNDEBUG(ifp, 1016 "%s waiting for data, minor = %#x\n", ifp->if_xname, 1017 minor(dev)); 1018 ret = 0; 1019 } 1020 1021 return (ret); 1022 } 1023 1024 /* 1025 * Always can write, always return MTU in kn->data. 1026 */ 1027 static int 1028 tunkqwrite(struct knote *kn, long hint) 1029 { 1030 struct tun_softc *tp = kn->kn_hook; 1031 struct ifnet *ifp = TUN2IFP(tp); 1032 1033 kn->kn_data = ifp->if_mtu; 1034 1035 return (1); 1036 } 1037 1038 static void 1039 tunkqdetach(struct knote *kn) 1040 { 1041 struct tun_softc *tp = kn->kn_hook; 1042 1043 knlist_remove(&tp->tun_rsel.si_note, kn, 0); 1044 }
Cache object: 6ba32e133d10107ea296b4946372f676
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