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/8.3/sys/net/if_tun.c 231380 2012-02-10 13:15:11Z bz $ 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 */ 69 struct 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 #define TUNNAME "tun" 103 104 /* 105 * All mutable global variables in if_tun are locked using tunmtx, with 106 * the exception of tundebug, which is used unlocked, and tunclones, 107 * which is static after setup. 108 */ 109 static struct mtx tunmtx; 110 static MALLOC_DEFINE(M_TUN, TUNNAME, "Tunnel Interface"); 111 static int tundebug = 0; 112 static int tundclone = 1; 113 static struct clonedevs *tunclones; 114 static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead); 115 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, ""); 116 117 SYSCTL_DECL(_net_link); 118 SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0, 119 "IP tunnel software network interface."); 120 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tundclone, 0, 121 "Enable legacy devfs interface creation."); 122 123 TUNABLE_INT("net.link.tun.devfs_cloning", &tundclone); 124 125 static void tunclone(void *arg, struct ucred *cred, char *name, 126 int namelen, struct cdev **dev); 127 static void tuncreate(const char *name, struct cdev *dev); 128 static int tunifioctl(struct ifnet *, u_long, caddr_t); 129 static void tuninit(struct ifnet *); 130 static int tunmodevent(module_t, int, void *); 131 static int tunoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 132 struct route *ro); 133 static void tunstart(struct ifnet *); 134 135 static int tun_clone_create(struct if_clone *, int, caddr_t); 136 static void tun_clone_destroy(struct ifnet *); 137 138 IFC_SIMPLE_DECLARE(tun, 0); 139 140 static d_open_t tunopen; 141 static d_close_t tunclose; 142 static d_read_t tunread; 143 static d_write_t tunwrite; 144 static d_ioctl_t tunioctl; 145 static d_poll_t tunpoll; 146 static d_kqfilter_t tunkqfilter; 147 148 static int tunkqread(struct knote *, long); 149 static int tunkqwrite(struct knote *, long); 150 static void tunkqdetach(struct knote *); 151 152 static struct filterops tun_read_filterops = { 153 .f_isfd = 1, 154 .f_attach = NULL, 155 .f_detach = tunkqdetach, 156 .f_event = tunkqread, 157 }; 158 159 static struct filterops tun_write_filterops = { 160 .f_isfd = 1, 161 .f_attach = NULL, 162 .f_detach = tunkqdetach, 163 .f_event = tunkqwrite, 164 }; 165 166 static struct cdevsw tun_cdevsw = { 167 .d_version = D_VERSION, 168 .d_flags = D_PSEUDO | D_NEEDMINOR, 169 .d_open = tunopen, 170 .d_close = tunclose, 171 .d_read = tunread, 172 .d_write = tunwrite, 173 .d_ioctl = tunioctl, 174 .d_poll = tunpoll, 175 .d_kqfilter = tunkqfilter, 176 .d_name = TUNNAME, 177 }; 178 179 static int 180 tun_clone_create(struct if_clone *ifc, int unit, caddr_t params) 181 { 182 struct cdev *dev; 183 int i; 184 185 /* find any existing device, or allocate new unit number */ 186 i = clone_create(&tunclones, &tun_cdevsw, &unit, &dev, 0); 187 if (i) { 188 /* No preexisting struct cdev *, create one */ 189 dev = make_dev(&tun_cdevsw, unit, 190 UID_UUCP, GID_DIALER, 0600, "%s%d", ifc->ifc_name, unit); 191 } 192 tuncreate(ifc->ifc_name, dev); 193 194 return (0); 195 } 196 197 static void 198 tunclone(void *arg, struct ucred *cred, char *name, int namelen, 199 struct cdev **dev) 200 { 201 char devname[SPECNAMELEN + 1]; 202 int u, i, append_unit; 203 204 if (*dev != NULL) 205 return; 206 207 /* 208 * If tun cloning is enabled, only the superuser can create an 209 * interface. 210 */ 211 if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0) 212 return; 213 214 if (strcmp(name, TUNNAME) == 0) { 215 u = -1; 216 } else if (dev_stdclone(name, NULL, TUNNAME, &u) != 1) 217 return; /* Don't recognise the name */ 218 if (u != -1 && u > IF_MAXUNIT) 219 return; /* Unit number too high */ 220 221 if (u == -1) 222 append_unit = 1; 223 else 224 append_unit = 0; 225 226 CURVNET_SET(CRED_TO_VNET(cred)); 227 /* find any existing device, or allocate new unit number */ 228 i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0); 229 if (i) { 230 if (append_unit) { 231 namelen = snprintf(devname, sizeof(devname), "%s%d", 232 name, u); 233 name = devname; 234 } 235 /* No preexisting struct cdev *, create one */ 236 *dev = make_dev_credf(MAKEDEV_REF, &tun_cdevsw, u, cred, 237 UID_UUCP, GID_DIALER, 0600, "%s", name); 238 } 239 240 if_clone_create(name, namelen, NULL); 241 CURVNET_RESTORE(); 242 } 243 244 static void 245 tun_destroy(struct tun_softc *tp) 246 { 247 struct cdev *dev; 248 249 /* Unlocked read. */ 250 mtx_lock(&tp->tun_mtx); 251 if ((tp->tun_flags & TUN_OPEN) != 0) 252 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx); 253 else 254 mtx_unlock(&tp->tun_mtx); 255 256 CURVNET_SET(TUN2IFP(tp)->if_vnet); 257 dev = tp->tun_dev; 258 bpfdetach(TUN2IFP(tp)); 259 if_detach(TUN2IFP(tp)); 260 if_free(TUN2IFP(tp)); 261 destroy_dev(dev); 262 seldrain(&tp->tun_rsel); 263 knlist_destroy(&tp->tun_rsel.si_note); 264 mtx_destroy(&tp->tun_mtx); 265 cv_destroy(&tp->tun_cv); 266 free(tp, M_TUN); 267 CURVNET_RESTORE(); 268 } 269 270 static void 271 tun_clone_destroy(struct ifnet *ifp) 272 { 273 struct tun_softc *tp = ifp->if_softc; 274 275 mtx_lock(&tunmtx); 276 TAILQ_REMOVE(&tunhead, tp, tun_list); 277 mtx_unlock(&tunmtx); 278 tun_destroy(tp); 279 } 280 281 static int 282 tunmodevent(module_t mod, int type, void *data) 283 { 284 static eventhandler_tag tag; 285 struct tun_softc *tp; 286 287 switch (type) { 288 case MOD_LOAD: 289 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF); 290 clone_setup(&tunclones); 291 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000); 292 if (tag == NULL) 293 return (ENOMEM); 294 if_clone_attach(&tun_cloner); 295 break; 296 case MOD_UNLOAD: 297 if_clone_detach(&tun_cloner); 298 EVENTHANDLER_DEREGISTER(dev_clone, tag); 299 drain_dev_clone_events(); 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 } 317 318 static moduledata_t tun_mod = { 319 "if_tun", 320 tunmodevent, 321 0 322 }; 323 324 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 325 326 static void 327 tunstart(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 selwakeuppri(&tp->tun_rsel, PZERO + 1); 349 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0); 350 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) { 351 mtx_unlock(&tp->tun_mtx); 352 pgsigio(&tp->tun_sigio, SIGIO, 0); 353 } else 354 mtx_unlock(&tp->tun_mtx); 355 } 356 357 /* XXX: should return an error code so it can fail. */ 358 static void 359 tuncreate(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 cv_init(&sc->tun_cv, "tun_condvar"); 369 sc->tun_flags = TUN_INITED; 370 sc->tun_dev = dev; 371 mtx_lock(&tunmtx); 372 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list); 373 mtx_unlock(&tunmtx); 374 375 ifp = sc->tun_ifp = if_alloc(IFT_PPP); 376 if (ifp == NULL) 377 panic("%s%d: failed to if_alloc() interface.\n", 378 name, dev2unit(dev)); 379 if_initname(ifp, name, dev2unit(dev)); 380 ifp->if_mtu = TUNMTU; 381 ifp->if_ioctl = tunifioctl; 382 ifp->if_output = tunoutput; 383 ifp->if_start = tunstart; 384 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 385 ifp->if_softc = sc; 386 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen); 387 ifp->if_snd.ifq_drv_maxlen = 0; 388 IFQ_SET_READY(&ifp->if_snd); 389 knlist_init_mtx(&sc->tun_rsel.si_note, &sc->tun_mtx); 390 ifp->if_capabilities |= IFCAP_LINKSTATE; 391 ifp->if_capenable |= IFCAP_LINKSTATE; 392 393 if_attach(ifp); 394 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 395 dev->si_drv1 = sc; 396 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n", 397 ifp->if_xname, dev2unit(dev)); 398 } 399 400 static int 401 tunopen(struct cdev *dev, int flag, int mode, struct thread *td) 402 { 403 struct ifnet *ifp; 404 struct tun_softc *tp; 405 406 /* 407 * XXXRW: Non-atomic test and set of dev->si_drv1 requires 408 * synchronization. 409 */ 410 tp = dev->si_drv1; 411 if (!tp) { 412 tuncreate(TUNNAME, dev); 413 tp = dev->si_drv1; 414 } 415 416 /* 417 * XXXRW: This use of tun_pid is subject to error due to the 418 * fact that a reference to the tunnel can live beyond the 419 * death of the process that created it. Can we replace this 420 * with a simple busy flag? 421 */ 422 mtx_lock(&tp->tun_mtx); 423 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) { 424 mtx_unlock(&tp->tun_mtx); 425 return (EBUSY); 426 } 427 tp->tun_pid = td->td_proc->p_pid; 428 429 tp->tun_flags |= TUN_OPEN; 430 ifp = TUN2IFP(tp); 431 if_link_state_change(ifp, LINK_STATE_UP); 432 TUNDEBUG(ifp, "open\n"); 433 mtx_unlock(&tp->tun_mtx); 434 435 return (0); 436 } 437 438 /* 439 * tunclose - close the device - mark i/f down & delete 440 * routing info 441 */ 442 static int 443 tunclose(struct cdev *dev, int foo, int bar, struct thread *td) 444 { 445 struct tun_softc *tp; 446 struct ifnet *ifp; 447 448 tp = dev->si_drv1; 449 ifp = TUN2IFP(tp); 450 451 mtx_lock(&tp->tun_mtx); 452 tp->tun_flags &= ~TUN_OPEN; 453 tp->tun_pid = 0; 454 455 /* 456 * junk all pending output 457 */ 458 CURVNET_SET(ifp->if_vnet); 459 IFQ_PURGE(&ifp->if_snd); 460 461 if (ifp->if_flags & IFF_UP) { 462 mtx_unlock(&tp->tun_mtx); 463 if_down(ifp); 464 mtx_lock(&tp->tun_mtx); 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 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 472 mtx_unlock(&tp->tun_mtx); 473 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 474 /* deal w/IPv4 PtP destination; unlocked read */ 475 if (ifa->ifa_addr->sa_family == AF_INET) { 476 rtinit(ifa, (int)RTM_DELETE, 477 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0); 478 } else { 479 rtinit(ifa, (int)RTM_DELETE, 0); 480 } 481 } 482 if_purgeaddrs(ifp); 483 mtx_lock(&tp->tun_mtx); 484 } 485 if_link_state_change(ifp, LINK_STATE_DOWN); 486 CURVNET_RESTORE(); 487 488 funsetown(&tp->tun_sigio); 489 selwakeuppri(&tp->tun_rsel, PZERO + 1); 490 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0); 491 TUNDEBUG (ifp, "closed\n"); 492 493 cv_broadcast(&tp->tun_cv); 494 mtx_unlock(&tp->tun_mtx); 495 return (0); 496 } 497 498 static void 499 tuninit(struct ifnet *ifp) 500 { 501 struct tun_softc *tp = ifp->if_softc; 502 #ifdef INET 503 struct ifaddr *ifa; 504 #endif 505 506 TUNDEBUG(ifp, "tuninit\n"); 507 508 mtx_lock(&tp->tun_mtx); 509 ifp->if_flags |= IFF_UP; 510 ifp->if_drv_flags |= IFF_DRV_RUNNING; 511 getmicrotime(&ifp->if_lastchange); 512 513 #ifdef INET 514 if_addr_rlock(ifp); 515 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 516 if (ifa->ifa_addr->sa_family == AF_INET) { 517 struct sockaddr_in *si; 518 519 si = (struct sockaddr_in *)ifa->ifa_addr; 520 if (si->sin_addr.s_addr) 521 tp->tun_flags |= TUN_IASET; 522 523 si = (struct sockaddr_in *)ifa->ifa_dstaddr; 524 if (si && si->sin_addr.s_addr) 525 tp->tun_flags |= TUN_DSTADDR; 526 } 527 } 528 if_addr_runlock(ifp); 529 #endif 530 mtx_unlock(&tp->tun_mtx); 531 } 532 533 /* 534 * Process an ioctl request. 535 */ 536 static int 537 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 538 { 539 struct ifreq *ifr = (struct ifreq *)data; 540 struct tun_softc *tp = ifp->if_softc; 541 struct ifstat *ifs; 542 int error = 0; 543 544 switch(cmd) { 545 case SIOCGIFSTATUS: 546 ifs = (struct ifstat *)data; 547 mtx_lock(&tp->tun_mtx); 548 if (tp->tun_pid) 549 sprintf(ifs->ascii + strlen(ifs->ascii), 550 "\tOpened by PID %d\n", tp->tun_pid); 551 mtx_unlock(&tp->tun_mtx); 552 break; 553 case SIOCSIFADDR: 554 tuninit(ifp); 555 TUNDEBUG(ifp, "address set\n"); 556 break; 557 case SIOCSIFDSTADDR: 558 tuninit(ifp); 559 TUNDEBUG(ifp, "destination address set\n"); 560 break; 561 case SIOCSIFMTU: 562 ifp->if_mtu = ifr->ifr_mtu; 563 TUNDEBUG(ifp, "mtu set\n"); 564 break; 565 case SIOCSIFFLAGS: 566 case SIOCADDMULTI: 567 case SIOCDELMULTI: 568 break; 569 default: 570 error = EINVAL; 571 } 572 return (error); 573 } 574 575 /* 576 * tunoutput - queue packets from higher level ready to put out. 577 */ 578 static int 579 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 580 struct route *ro) 581 { 582 struct tun_softc *tp = ifp->if_softc; 583 u_short cached_tun_flags; 584 int error; 585 u_int32_t af; 586 587 TUNDEBUG (ifp, "tunoutput\n"); 588 589 #ifdef MAC 590 error = mac_ifnet_check_transmit(ifp, m0); 591 if (error) { 592 m_freem(m0); 593 return (error); 594 } 595 #endif 596 597 /* Could be unlocked read? */ 598 mtx_lock(&tp->tun_mtx); 599 cached_tun_flags = tp->tun_flags; 600 mtx_unlock(&tp->tun_mtx); 601 if ((cached_tun_flags & TUN_READY) != TUN_READY) { 602 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 603 m_freem (m0); 604 return (EHOSTDOWN); 605 } 606 607 if ((ifp->if_flags & IFF_UP) != IFF_UP) { 608 m_freem (m0); 609 return (EHOSTDOWN); 610 } 611 612 /* BPF writes need to be handled specially. */ 613 if (dst->sa_family == AF_UNSPEC) { 614 bcopy(dst->sa_data, &af, sizeof(af)); 615 dst->sa_family = af; 616 } 617 618 if (bpf_peers_present(ifp->if_bpf)) { 619 af = dst->sa_family; 620 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0); 621 } 622 623 /* prepend sockaddr? this may abort if the mbuf allocation fails */ 624 if (cached_tun_flags & TUN_LMODE) { 625 /* allocate space for sockaddr */ 626 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 627 628 /* if allocation failed drop packet */ 629 if (m0 == NULL) { 630 ifp->if_iqdrops++; 631 ifp->if_oerrors++; 632 return (ENOBUFS); 633 } else { 634 bcopy(dst, m0->m_data, dst->sa_len); 635 } 636 } 637 638 if (cached_tun_flags & TUN_IFHEAD) { 639 /* Prepend the address family */ 640 M_PREPEND(m0, 4, M_DONTWAIT); 641 642 /* if allocation failed drop packet */ 643 if (m0 == NULL) { 644 ifp->if_iqdrops++; 645 ifp->if_oerrors++; 646 return (ENOBUFS); 647 } else 648 *(u_int32_t *)m0->m_data = htonl(dst->sa_family); 649 } else { 650 #ifdef INET 651 if (dst->sa_family != AF_INET) 652 #endif 653 { 654 m_freem(m0); 655 return (EAFNOSUPPORT); 656 } 657 } 658 659 error = (ifp->if_transmit)(ifp, m0); 660 if (error) 661 return (ENOBUFS); 662 ifp->if_opackets++; 663 return (0); 664 } 665 666 /* 667 * the cdevsw interface is now pretty minimal. 668 */ 669 static int 670 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, 671 struct thread *td) 672 { 673 int error; 674 struct tun_softc *tp = dev->si_drv1; 675 struct tuninfo *tunp; 676 677 switch (cmd) { 678 case TUNSIFINFO: 679 tunp = (struct tuninfo *)data; 680 if (tunp->mtu < IF_MINMTU) 681 return (EINVAL); 682 if (TUN2IFP(tp)->if_mtu != tunp->mtu) { 683 error = priv_check(td, PRIV_NET_SETIFMTU); 684 if (error) 685 return (error); 686 } 687 mtx_lock(&tp->tun_mtx); 688 TUN2IFP(tp)->if_mtu = tunp->mtu; 689 TUN2IFP(tp)->if_type = tunp->type; 690 TUN2IFP(tp)->if_baudrate = tunp->baudrate; 691 mtx_unlock(&tp->tun_mtx); 692 break; 693 case TUNGIFINFO: 694 tunp = (struct tuninfo *)data; 695 mtx_lock(&tp->tun_mtx); 696 tunp->mtu = TUN2IFP(tp)->if_mtu; 697 tunp->type = TUN2IFP(tp)->if_type; 698 tunp->baudrate = TUN2IFP(tp)->if_baudrate; 699 mtx_unlock(&tp->tun_mtx); 700 break; 701 case TUNSDEBUG: 702 tundebug = *(int *)data; 703 break; 704 case TUNGDEBUG: 705 *(int *)data = tundebug; 706 break; 707 case TUNSLMODE: 708 mtx_lock(&tp->tun_mtx); 709 if (*(int *)data) { 710 tp->tun_flags |= TUN_LMODE; 711 tp->tun_flags &= ~TUN_IFHEAD; 712 } else 713 tp->tun_flags &= ~TUN_LMODE; 714 mtx_unlock(&tp->tun_mtx); 715 break; 716 case TUNSIFHEAD: 717 mtx_lock(&tp->tun_mtx); 718 if (*(int *)data) { 719 tp->tun_flags |= TUN_IFHEAD; 720 tp->tun_flags &= ~TUN_LMODE; 721 } else 722 tp->tun_flags &= ~TUN_IFHEAD; 723 mtx_unlock(&tp->tun_mtx); 724 break; 725 case TUNGIFHEAD: 726 mtx_lock(&tp->tun_mtx); 727 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 728 mtx_unlock(&tp->tun_mtx); 729 break; 730 case TUNSIFMODE: 731 /* deny this if UP */ 732 if (TUN2IFP(tp)->if_flags & IFF_UP) 733 return(EBUSY); 734 735 switch (*(int *)data & ~IFF_MULTICAST) { 736 case IFF_POINTOPOINT: 737 case IFF_BROADCAST: 738 mtx_lock(&tp->tun_mtx); 739 TUN2IFP(tp)->if_flags &= 740 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 741 TUN2IFP(tp)->if_flags |= *(int *)data; 742 mtx_unlock(&tp->tun_mtx); 743 break; 744 default: 745 return(EINVAL); 746 } 747 break; 748 case TUNSIFPID: 749 mtx_lock(&tp->tun_mtx); 750 tp->tun_pid = curthread->td_proc->p_pid; 751 mtx_unlock(&tp->tun_mtx); 752 break; 753 case FIONBIO: 754 break; 755 case FIOASYNC: 756 mtx_lock(&tp->tun_mtx); 757 if (*(int *)data) 758 tp->tun_flags |= TUN_ASYNC; 759 else 760 tp->tun_flags &= ~TUN_ASYNC; 761 mtx_unlock(&tp->tun_mtx); 762 break; 763 case FIONREAD: 764 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) { 765 struct mbuf *mb; 766 IFQ_LOCK(&TUN2IFP(tp)->if_snd); 767 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb); 768 for (*(int *)data = 0; mb != NULL; mb = mb->m_next) 769 *(int *)data += mb->m_len; 770 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd); 771 } else 772 *(int *)data = 0; 773 break; 774 case FIOSETOWN: 775 return (fsetown(*(int *)data, &tp->tun_sigio)); 776 777 case FIOGETOWN: 778 *(int *)data = fgetown(&tp->tun_sigio); 779 return (0); 780 781 /* This is deprecated, FIOSETOWN should be used instead. */ 782 case TIOCSPGRP: 783 return (fsetown(-(*(int *)data), &tp->tun_sigio)); 784 785 /* This is deprecated, FIOGETOWN should be used instead. */ 786 case TIOCGPGRP: 787 *(int *)data = -fgetown(&tp->tun_sigio); 788 return (0); 789 790 default: 791 return (ENOTTY); 792 } 793 return (0); 794 } 795 796 /* 797 * The cdevsw read interface - reads a packet at a time, or at 798 * least as much of a packet as can be read. 799 */ 800 static int 801 tunread(struct cdev *dev, struct uio *uio, int flag) 802 { 803 struct tun_softc *tp = dev->si_drv1; 804 struct ifnet *ifp = TUN2IFP(tp); 805 struct mbuf *m; 806 int error=0, len; 807 808 TUNDEBUG (ifp, "read\n"); 809 mtx_lock(&tp->tun_mtx); 810 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 811 mtx_unlock(&tp->tun_mtx); 812 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 813 return (EHOSTDOWN); 814 } 815 816 tp->tun_flags &= ~TUN_RWAIT; 817 818 do { 819 IFQ_DEQUEUE(&ifp->if_snd, m); 820 if (m == NULL) { 821 if (flag & O_NONBLOCK) { 822 mtx_unlock(&tp->tun_mtx); 823 return (EWOULDBLOCK); 824 } 825 tp->tun_flags |= TUN_RWAIT; 826 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1), 827 "tunread", 0); 828 if (error != 0) { 829 mtx_unlock(&tp->tun_mtx); 830 return (error); 831 } 832 } 833 } while (m == NULL); 834 mtx_unlock(&tp->tun_mtx); 835 836 while (m && uio->uio_resid > 0 && error == 0) { 837 len = min(uio->uio_resid, m->m_len); 838 if (len != 0) 839 error = uiomove(mtod(m, void *), len, uio); 840 m = m_free(m); 841 } 842 843 if (m) { 844 TUNDEBUG(ifp, "Dropping mbuf\n"); 845 m_freem(m); 846 } 847 return (error); 848 } 849 850 /* 851 * the cdevsw write interface - an atomic write is a packet - or else! 852 */ 853 static int 854 tunwrite(struct cdev *dev, struct uio *uio, int flag) 855 { 856 struct tun_softc *tp = dev->si_drv1; 857 struct ifnet *ifp = TUN2IFP(tp); 858 struct mbuf *m; 859 uint32_t family; 860 int isr; 861 862 TUNDEBUG(ifp, "tunwrite\n"); 863 864 if ((ifp->if_flags & IFF_UP) != IFF_UP) 865 /* ignore silently */ 866 return (0); 867 868 if (uio->uio_resid == 0) 869 return (0); 870 871 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) { 872 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid); 873 return (EIO); 874 } 875 876 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) { 877 ifp->if_ierrors++; 878 return (ENOBUFS); 879 } 880 881 m->m_pkthdr.rcvif = ifp; 882 #ifdef MAC 883 mac_ifnet_create_mbuf(ifp, m); 884 #endif 885 886 /* Could be unlocked read? */ 887 mtx_lock(&tp->tun_mtx); 888 if (tp->tun_flags & TUN_IFHEAD) { 889 mtx_unlock(&tp->tun_mtx); 890 if (m->m_len < sizeof(family) && 891 (m = m_pullup(m, sizeof(family))) == NULL) 892 return (ENOBUFS); 893 family = ntohl(*mtod(m, u_int32_t *)); 894 m_adj(m, sizeof(family)); 895 } else { 896 mtx_unlock(&tp->tun_mtx); 897 family = AF_INET; 898 } 899 900 BPF_MTAP2(ifp, &family, sizeof(family), m); 901 902 switch (family) { 903 #ifdef INET 904 case AF_INET: 905 isr = NETISR_IP; 906 break; 907 #endif 908 #ifdef INET6 909 case AF_INET6: 910 isr = NETISR_IPV6; 911 break; 912 #endif 913 #ifdef IPX 914 case AF_IPX: 915 isr = NETISR_IPX; 916 break; 917 #endif 918 #ifdef NETATALK 919 case AF_APPLETALK: 920 isr = NETISR_ATALK2; 921 break; 922 #endif 923 default: 924 m_freem(m); 925 return (EAFNOSUPPORT); 926 } 927 /* First chunk of an mbuf contains good junk */ 928 if (harvest.point_to_point) 929 random_harvest(m, 16, 3, 0, RANDOM_NET); 930 ifp->if_ibytes += m->m_pkthdr.len; 931 ifp->if_ipackets++; 932 CURVNET_SET(ifp->if_vnet); 933 M_SETFIB(m, ifp->if_fib); 934 netisr_dispatch(isr, m); 935 CURVNET_RESTORE(); 936 return (0); 937 } 938 939 /* 940 * tunpoll - the poll interface, this is only useful on reads 941 * really. The write detect always returns true, write never blocks 942 * anyway, it either accepts the packet or drops it. 943 */ 944 static int 945 tunpoll(struct cdev *dev, int events, struct thread *td) 946 { 947 struct tun_softc *tp = dev->si_drv1; 948 struct ifnet *ifp = TUN2IFP(tp); 949 int revents = 0; 950 struct mbuf *m; 951 952 TUNDEBUG(ifp, "tunpoll\n"); 953 954 if (events & (POLLIN | POLLRDNORM)) { 955 IFQ_LOCK(&ifp->if_snd); 956 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 957 if (m != NULL) { 958 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len); 959 revents |= events & (POLLIN | POLLRDNORM); 960 } else { 961 TUNDEBUG(ifp, "tunpoll waiting\n"); 962 selrecord(td, &tp->tun_rsel); 963 } 964 IFQ_UNLOCK(&ifp->if_snd); 965 } 966 if (events & (POLLOUT | POLLWRNORM)) 967 revents |= events & (POLLOUT | POLLWRNORM); 968 969 return (revents); 970 } 971 972 /* 973 * tunkqfilter - support for the kevent() system call. 974 */ 975 static int 976 tunkqfilter(struct cdev *dev, struct knote *kn) 977 { 978 struct tun_softc *tp = dev->si_drv1; 979 struct ifnet *ifp = TUN2IFP(tp); 980 981 switch(kn->kn_filter) { 982 case EVFILT_READ: 983 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n", 984 ifp->if_xname, dev2unit(dev)); 985 kn->kn_fop = &tun_read_filterops; 986 break; 987 988 case EVFILT_WRITE: 989 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n", 990 ifp->if_xname, dev2unit(dev)); 991 kn->kn_fop = &tun_write_filterops; 992 break; 993 994 default: 995 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n", 996 ifp->if_xname, dev2unit(dev)); 997 return(EINVAL); 998 } 999 1000 kn->kn_hook = tp; 1001 knlist_add(&tp->tun_rsel.si_note, kn, 0); 1002 1003 return (0); 1004 } 1005 1006 /* 1007 * Return true of there is data in the interface queue. 1008 */ 1009 static int 1010 tunkqread(struct knote *kn, long hint) 1011 { 1012 int ret; 1013 struct tun_softc *tp = kn->kn_hook; 1014 struct cdev *dev = tp->tun_dev; 1015 struct ifnet *ifp = TUN2IFP(tp); 1016 1017 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) { 1018 TUNDEBUG(ifp, 1019 "%s have data in the queue. Len = %d, minor = %#x\n", 1020 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev)); 1021 ret = 1; 1022 } else { 1023 TUNDEBUG(ifp, 1024 "%s waiting for data, minor = %#x\n", ifp->if_xname, 1025 dev2unit(dev)); 1026 ret = 0; 1027 } 1028 1029 return (ret); 1030 } 1031 1032 /* 1033 * Always can write, always return MTU in kn->data. 1034 */ 1035 static int 1036 tunkqwrite(struct knote *kn, long hint) 1037 { 1038 struct tun_softc *tp = kn->kn_hook; 1039 struct ifnet *ifp = TUN2IFP(tp); 1040 1041 kn->kn_data = ifp->if_mtu; 1042 1043 return (1); 1044 } 1045 1046 static void 1047 tunkqdetach(struct knote *kn) 1048 { 1049 struct tun_softc *tp = kn->kn_hook; 1050 1051 knlist_remove(&tp->tun_rsel.si_note, kn, 0); 1052 }
Cache object: 4e82c687cfb3cb02d70a65b5405129b8
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