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 * $FreeBSD$ 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 102 103 /* 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 const char tunname[] = "tun"; 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 static 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 *, 132 const struct sockaddr *, 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 static struct if_clone *tun_cloner; 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_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 }; 177 178 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, unit, 189 UID_UUCP, GID_DIALER, 0600, "%s%d", tunname, unit); 190 } 191 tuncreate(tunname, 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 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 } 242 243 static void 244 tun_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_clear(&tp->tun_rsel.si_note, 0); 262 knlist_destroy(&tp->tun_rsel.si_note); 263 mtx_destroy(&tp->tun_mtx); 264 cv_destroy(&tp->tun_cv); 265 free(tp, M_TUN); 266 CURVNET_RESTORE(); 267 } 268 269 static void 270 tun_clone_destroy(struct ifnet *ifp) 271 { 272 struct tun_softc *tp = ifp->if_softc; 273 274 mtx_lock(&tunmtx); 275 TAILQ_REMOVE(&tunhead, tp, tun_list); 276 mtx_unlock(&tunmtx); 277 tun_destroy(tp); 278 } 279 280 static int 281 tunmodevent(module_t mod, int type, void *data) 282 { 283 static eventhandler_tag tag; 284 struct tun_softc *tp; 285 286 switch (type) { 287 case MOD_LOAD: 288 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF); 289 clone_setup(&tunclones); 290 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000); 291 if (tag == NULL) 292 return (ENOMEM); 293 tun_cloner = if_clone_simple(tunname, tun_clone_create, 294 tun_clone_destroy, 0); 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 MODULE_VERSION(if_tun, 1); 326 327 static void 328 tunstart(struct ifnet *ifp) 329 { 330 struct tun_softc *tp = ifp->if_softc; 331 struct mbuf *m; 332 333 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname); 334 if (ALTQ_IS_ENABLED(&ifp->if_snd)) { 335 IFQ_LOCK(&ifp->if_snd); 336 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 337 if (m == NULL) { 338 IFQ_UNLOCK(&ifp->if_snd); 339 return; 340 } 341 IFQ_UNLOCK(&ifp->if_snd); 342 } 343 344 mtx_lock(&tp->tun_mtx); 345 if (tp->tun_flags & TUN_RWAIT) { 346 tp->tun_flags &= ~TUN_RWAIT; 347 wakeup(tp); 348 } 349 selwakeuppri(&tp->tun_rsel, PZERO + 1); 350 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0); 351 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) { 352 mtx_unlock(&tp->tun_mtx); 353 pgsigio(&tp->tun_sigio, SIGIO, 0); 354 } else 355 mtx_unlock(&tp->tun_mtx); 356 } 357 358 /* XXX: should return an error code so it can fail. */ 359 static void 360 tuncreate(const char *name, struct cdev *dev) 361 { 362 struct tun_softc *sc; 363 struct ifnet *ifp; 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 } 398 399 static int 400 tunopen(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 */ 441 static int 442 tunclose(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 } 496 497 static void 498 tuninit(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 */ 535 static int 536 tunifioctl(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 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 return (error); 568 } 569 570 /* 571 * tunoutput - queue packets from higher level ready to put out. 572 */ 573 static int 574 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, 575 struct route *ro) 576 { 577 struct tun_softc *tp = ifp->if_softc; 578 u_short cached_tun_flags; 579 int error; 580 u_int32_t af; 581 582 TUNDEBUG (ifp, "tunoutput\n"); 583 584 #ifdef MAC 585 error = mac_ifnet_check_transmit(ifp, m0); 586 if (error) { 587 m_freem(m0); 588 return (error); 589 } 590 #endif 591 592 /* Could be unlocked read? */ 593 mtx_lock(&tp->tun_mtx); 594 cached_tun_flags = tp->tun_flags; 595 mtx_unlock(&tp->tun_mtx); 596 if ((cached_tun_flags & TUN_READY) != TUN_READY) { 597 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 598 m_freem (m0); 599 return (EHOSTDOWN); 600 } 601 602 if ((ifp->if_flags & IFF_UP) != IFF_UP) { 603 m_freem (m0); 604 return (EHOSTDOWN); 605 } 606 607 /* BPF writes need to be handled specially. */ 608 if (dst->sa_family == AF_UNSPEC) 609 bcopy(dst->sa_data, &af, sizeof(af)); 610 else 611 af = dst->sa_family; 612 613 if (bpf_peers_present(ifp->if_bpf)) 614 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0); 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_NOWAIT); 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_NOWAIT); 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(af); 642 } else { 643 #ifdef INET 644 if (af != AF_INET) 645 #endif 646 { 647 m_freem(m0); 648 return (EAFNOSUPPORT); 649 } 650 } 651 652 error = (ifp->if_transmit)(ifp, m0); 653 if (error) 654 return (ENOBUFS); 655 ifp->if_opackets++; 656 return (0); 657 } 658 659 /* 660 * the cdevsw interface is now pretty minimal. 661 */ 662 static int 663 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, 664 struct thread *td) 665 { 666 int error; 667 struct tun_softc *tp = dev->si_drv1; 668 struct tuninfo *tunp; 669 670 switch (cmd) { 671 case TUNSIFINFO: 672 tunp = (struct tuninfo *)data; 673 if (tunp->mtu < IF_MINMTU) 674 return (EINVAL); 675 if (TUN2IFP(tp)->if_mtu != tunp->mtu) { 676 error = priv_check(td, PRIV_NET_SETIFMTU); 677 if (error) 678 return (error); 679 } 680 if (TUN2IFP(tp)->if_type != tunp->type) 681 return (EPROTOTYPE); 682 mtx_lock(&tp->tun_mtx); 683 TUN2IFP(tp)->if_mtu = tunp->mtu; 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 uint32_t family; 854 int isr; 855 856 TUNDEBUG(ifp, "tunwrite\n"); 857 858 if ((ifp->if_flags & IFF_UP) != IFF_UP) 859 /* ignore silently */ 860 return (0); 861 862 if (uio->uio_resid == 0) 863 return (0); 864 865 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) { 866 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid); 867 return (EIO); 868 } 869 870 if ((m = m_uiotombuf(uio, M_NOWAIT, 0, 0, M_PKTHDR)) == NULL) { 871 ifp->if_ierrors++; 872 return (ENOBUFS); 873 } 874 875 m->m_pkthdr.rcvif = ifp; 876 #ifdef MAC 877 mac_ifnet_create_mbuf(ifp, m); 878 #endif 879 880 /* Could be unlocked read? */ 881 mtx_lock(&tp->tun_mtx); 882 if (tp->tun_flags & TUN_IFHEAD) { 883 mtx_unlock(&tp->tun_mtx); 884 if (m->m_len < sizeof(family) && 885 (m = m_pullup(m, sizeof(family))) == NULL) 886 return (ENOBUFS); 887 family = ntohl(*mtod(m, u_int32_t *)); 888 m_adj(m, sizeof(family)); 889 } else { 890 mtx_unlock(&tp->tun_mtx); 891 family = AF_INET; 892 } 893 894 BPF_MTAP2(ifp, &family, sizeof(family), m); 895 896 switch (family) { 897 #ifdef INET 898 case AF_INET: 899 isr = NETISR_IP; 900 break; 901 #endif 902 #ifdef INET6 903 case AF_INET6: 904 isr = NETISR_IPV6; 905 break; 906 #endif 907 #ifdef IPX 908 case AF_IPX: 909 isr = NETISR_IPX; 910 break; 911 #endif 912 #ifdef NETATALK 913 case AF_APPLETALK: 914 isr = NETISR_ATALK2; 915 break; 916 #endif 917 default: 918 m_freem(m); 919 return (EAFNOSUPPORT); 920 } 921 if (harvest.point_to_point) 922 random_harvest(&(m->m_data), 12, 2, RANDOM_NET_TUN); 923 ifp->if_ibytes += m->m_pkthdr.len; 924 ifp->if_ipackets++; 925 CURVNET_SET(ifp->if_vnet); 926 M_SETFIB(m, ifp->if_fib); 927 netisr_dispatch(isr, m); 928 CURVNET_RESTORE(); 929 return (0); 930 } 931 932 /* 933 * tunpoll - the poll interface, this is only useful on reads 934 * really. The write detect always returns true, write never blocks 935 * anyway, it either accepts the packet or drops it. 936 */ 937 static int 938 tunpoll(struct cdev *dev, int events, struct thread *td) 939 { 940 struct tun_softc *tp = dev->si_drv1; 941 struct ifnet *ifp = TUN2IFP(tp); 942 int revents = 0; 943 struct mbuf *m; 944 945 TUNDEBUG(ifp, "tunpoll\n"); 946 947 if (events & (POLLIN | POLLRDNORM)) { 948 IFQ_LOCK(&ifp->if_snd); 949 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 950 if (m != NULL) { 951 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len); 952 revents |= events & (POLLIN | POLLRDNORM); 953 } else { 954 TUNDEBUG(ifp, "tunpoll waiting\n"); 955 selrecord(td, &tp->tun_rsel); 956 } 957 IFQ_UNLOCK(&ifp->if_snd); 958 } 959 if (events & (POLLOUT | POLLWRNORM)) 960 revents |= events & (POLLOUT | POLLWRNORM); 961 962 return (revents); 963 } 964 965 /* 966 * tunkqfilter - support for the kevent() system call. 967 */ 968 static int 969 tunkqfilter(struct cdev *dev, struct knote *kn) 970 { 971 struct tun_softc *tp = dev->si_drv1; 972 struct ifnet *ifp = TUN2IFP(tp); 973 974 switch(kn->kn_filter) { 975 case EVFILT_READ: 976 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n", 977 ifp->if_xname, dev2unit(dev)); 978 kn->kn_fop = &tun_read_filterops; 979 break; 980 981 case EVFILT_WRITE: 982 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n", 983 ifp->if_xname, dev2unit(dev)); 984 kn->kn_fop = &tun_write_filterops; 985 break; 986 987 default: 988 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n", 989 ifp->if_xname, dev2unit(dev)); 990 return(EINVAL); 991 } 992 993 kn->kn_hook = tp; 994 knlist_add(&tp->tun_rsel.si_note, kn, 0); 995 996 return (0); 997 } 998 999 /* 1000 * Return true of there is data in the interface queue. 1001 */ 1002 static int 1003 tunkqread(struct knote *kn, long hint) 1004 { 1005 int ret; 1006 struct tun_softc *tp = kn->kn_hook; 1007 struct cdev *dev = tp->tun_dev; 1008 struct ifnet *ifp = TUN2IFP(tp); 1009 1010 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) { 1011 TUNDEBUG(ifp, 1012 "%s have data in the queue. Len = %d, minor = %#x\n", 1013 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev)); 1014 ret = 1; 1015 } else { 1016 TUNDEBUG(ifp, 1017 "%s waiting for data, minor = %#x\n", ifp->if_xname, 1018 dev2unit(dev)); 1019 ret = 0; 1020 } 1021 1022 return (ret); 1023 } 1024 1025 /* 1026 * Always can write, always return MTU in kn->data. 1027 */ 1028 static int 1029 tunkqwrite(struct knote *kn, long hint) 1030 { 1031 struct tun_softc *tp = kn->kn_hook; 1032 struct ifnet *ifp = TUN2IFP(tp); 1033 1034 kn->kn_data = ifp->if_mtu; 1035 1036 return (1); 1037 } 1038 1039 static void 1040 tunkqdetach(struct knote *kn) 1041 { 1042 struct tun_softc *tp = kn->kn_hook; 1043 1044 knlist_remove(&tp->tun_rsel.si_note, kn, 0); 1045 }
Cache object: d9bb80102b383529867ae0083df70aef
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