if_tun.c revision 194990
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 194990 2009-06-25 18:46:30Z kib $ 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#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#include <sys/condvar.h> 61 62#include <security/mac/mac_framework.h> 63 64/* 65 * tun_list is protected by global tunmtx. Other mutable fields are 66 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is 67 * static for the duration of a tunnel interface. 68 */ 69struct tun_softc { 70 TAILQ_ENTRY(tun_softc) tun_list; 71 struct cdev *tun_dev; 72 u_short tun_flags; /* misc flags */ 73#define TUN_OPEN 0x0001 74#define TUN_INITED 0x0002 75#define TUN_RCOLL 0x0004 76#define TUN_IASET 0x0008 77#define TUN_DSTADDR 0x0010 78#define TUN_LMODE 0x0020 79#define TUN_RWAIT 0x0040 80#define TUN_ASYNC 0x0080 81#define TUN_IFHEAD 0x0100 82 83#define TUN_READY (TUN_OPEN | TUN_INITED) 84 85 /* 86 * XXXRW: tun_pid is used to exclusively lock /dev/tun. Is this 87 * actually needed? Can we just return EBUSY if already open? 88 * Problem is that this involved inherent races when a tun device 89 * is handed off from one process to another, as opposed to just 90 * being slightly stale informationally. 91 */ 92 pid_t tun_pid; /* owning pid */ 93 struct ifnet *tun_ifp; /* the interface */ 94 struct sigio *tun_sigio; /* information for async I/O */ 95 struct selinfo tun_rsel; /* read select */ 96 struct mtx tun_mtx; /* protect mutable softc fields */ 97 struct cv tun_cv; /* protect against ref'd dev destroy */ 98}; 99#define TUN2IFP(sc) ((sc)->tun_ifp) 100 101#define TUNDEBUG if (tundebug) if_printf 102#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 */ 109static struct mtx tunmtx; 110static MALLOC_DEFINE(M_TUN, TUNNAME, "Tunnel Interface"); 111static int tundebug = 0; 112static int tundclone = 1; 113static struct clonedevs *tunclones; 114static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead); 115SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, ""); 116 117SYSCTL_DECL(_net_link); 118SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0, 119 "IP tunnel software network interface."); 120SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tundclone, 0, 121 "Enable legacy devfs interface creation."); 122 123TUNABLE_INT("net.link.tun.devfs_cloning", &tundclone); 124 125static void tunclone(void *arg, struct ucred *cred, char *name, 126 int namelen, struct cdev **dev); 127static void tuncreate(const char *name, struct cdev *dev); 128static int tunifioctl(struct ifnet *, u_long, caddr_t); 129static int tuninit(struct ifnet *); 130static int tunmodevent(module_t, int, void *); 131static int tunoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 132 struct route *ro); 133static void tunstart(struct ifnet *); 134 135static int tun_clone_create(struct if_clone *, int, caddr_t); 136static void tun_clone_destroy(struct ifnet *); 137 138IFC_SIMPLE_DECLARE(tun, 0); 139 140static d_open_t tunopen; 141static d_close_t tunclose; 142static d_read_t tunread; 143static d_write_t tunwrite; 144static d_ioctl_t tunioctl; 145static d_poll_t tunpoll; 146static d_kqfilter_t tunkqfilter; 147 148static int tunkqread(struct knote *, long); 149static int tunkqwrite(struct knote *, long); 150static void tunkqdetach(struct knote *); 151 152static struct filterops tun_read_filterops = { 153 .f_isfd = 1, 154 .f_attach = NULL, 155 .f_detach = tunkqdetach, 156 .f_event = tunkqread, 157}; 158 159static struct filterops tun_write_filterops = { 160 .f_isfd = 1, 161 .f_attach = NULL, 162 .f_detach = tunkqdetach, 163 .f_event = tunkqwrite, 164}; 165 166static struct cdevsw tun_cdevsw = { 167 .d_version = D_VERSION, 168 .d_flags = D_PSEUDO | D_NEEDGIANT | 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 179static int 180tun_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 if (dev != NULL) { 192 dev_ref(dev); 193 dev->si_flags |= SI_CHEAPCLONE; 194 } 195 } 196 tuncreate(ifc->ifc_name, dev); 197 198 return (0); 199} 200 201static void 202tunclone(void *arg, struct ucred *cred, char *name, int namelen, 203 struct cdev **dev) 204{ 205 char devname[SPECNAMELEN + 1]; 206 int u, i, append_unit; 207 208 if (*dev != NULL) 209 return; 210 211 /* 212 * If tun cloning is enabled, only the superuser can create an 213 * interface. 214 */ 215 if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0) 216 return; 217 218 if (strcmp(name, TUNNAME) == 0) { 219 u = -1; 220 } else if (dev_stdclone(name, NULL, TUNNAME, &u) != 1) 221 return; /* Don't recognise the name */ 222 if (u != -1 && u > IF_MAXUNIT) 223 return; /* Unit number too high */ 224 225 if (u == -1) 226 append_unit = 1; 227 else 228 append_unit = 0; 229 230 CURVNET_SET(CRED_TO_VNET(cred)); 231 /* find any existing device, or allocate new unit number */ 232 i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0); 233 if (i) { 234 if (append_unit) { 235 namelen = snprintf(devname, sizeof(devname), "%s%d", name, 236 u); 237 name = devname; 238 } 239 /* No preexisting struct cdev *, create one */ 240 *dev = make_dev(&tun_cdevsw, u, 241 UID_UUCP, GID_DIALER, 0600, "%s", name); 242 if (*dev != NULL) { 243 dev_ref(*dev); 244 (*dev)->si_flags |= SI_CHEAPCLONE; 245 } 246 } 247 248 if_clone_create(name, namelen, NULL); 249 CURVNET_RESTORE(); 250} 251 252static void 253tun_destroy(struct tun_softc *tp) 254{ 255 struct cdev *dev; 256 257 /* Unlocked read. */ 258 mtx_lock(&tp->tun_mtx); 259 if ((tp->tun_flags & TUN_OPEN) != 0) 260 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx); 261 else 262 mtx_unlock(&tp->tun_mtx); 263 264 CURVNET_SET(TUN2IFP(tp)->if_vnet); 265 dev = tp->tun_dev; 266 bpfdetach(TUN2IFP(tp)); 267 if_detach(TUN2IFP(tp)); 268 if_free(TUN2IFP(tp)); 269 destroy_dev(dev); 270 knlist_destroy(&tp->tun_rsel.si_note); 271 mtx_destroy(&tp->tun_mtx); 272 cv_destroy(&tp->tun_cv); 273 free(tp, M_TUN); 274 CURVNET_RESTORE(); 275} 276 277static void 278tun_clone_destroy(struct ifnet *ifp) 279{ 280 struct tun_softc *tp = ifp->if_softc; 281 282 mtx_lock(&tunmtx); 283 TAILQ_REMOVE(&tunhead, tp, tun_list); 284 mtx_unlock(&tunmtx); 285 tun_destroy(tp); 286} 287 288static int 289tunmodevent(module_t mod, int type, void *data) 290{ 291 static eventhandler_tag tag; 292 struct tun_softc *tp; 293 294 switch (type) { 295 case MOD_LOAD: 296 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF); 297 clone_setup(&tunclones); 298 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000); 299 if (tag == NULL) 300 return (ENOMEM); 301 if_clone_attach(&tun_cloner); 302 break; 303 case MOD_UNLOAD: 304 if_clone_detach(&tun_cloner); 305 EVENTHANDLER_DEREGISTER(dev_clone, tag); 306 307 mtx_lock(&tunmtx); 308 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) { 309 TAILQ_REMOVE(&tunhead, tp, tun_list); 310 mtx_unlock(&tunmtx); 311 tun_destroy(tp); 312 mtx_lock(&tunmtx); 313 } 314 mtx_unlock(&tunmtx); 315 clone_cleanup(&tunclones); 316 mtx_destroy(&tunmtx); 317 break; 318 default: 319 return EOPNOTSUPP; 320 } 321 return 0; 322} 323 324static moduledata_t tun_mod = { 325 "if_tun", 326 tunmodevent, 327 0 328}; 329 330DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 331 332static void 333tunstart(struct ifnet *ifp) 334{ 335 struct tun_softc *tp = ifp->if_softc; 336 struct mbuf *m; 337 338 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname); 339 if (ALTQ_IS_ENABLED(&ifp->if_snd)) { 340 IFQ_LOCK(&ifp->if_snd); 341 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 342 if (m == NULL) { 343 IFQ_UNLOCK(&ifp->if_snd); 344 return; 345 } 346 IFQ_UNLOCK(&ifp->if_snd); 347 } 348 349 mtx_lock(&tp->tun_mtx); 350 if (tp->tun_flags & TUN_RWAIT) { 351 tp->tun_flags &= ~TUN_RWAIT; 352 wakeup(tp); 353 } 354 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) { 355 mtx_unlock(&tp->tun_mtx); 356 pgsigio(&tp->tun_sigio, SIGIO, 0); 357 } else 358 mtx_unlock(&tp->tun_mtx); 359 selwakeuppri(&tp->tun_rsel, PZERO + 1); 360 KNOTE_UNLOCKED(&tp->tun_rsel.si_note, 0); 361} 362 363/* XXX: should return an error code so it can fail. */ 364static void 365tuncreate(const char *name, struct cdev *dev) 366{ 367 struct tun_softc *sc; 368 struct ifnet *ifp; 369 370 dev->si_flags &= ~SI_CHEAPCLONE; 371 372 sc = malloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO); 373 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF); 374 cv_init(&sc->tun_cv, "tun_condvar"); 375 sc->tun_flags = TUN_INITED; 376 sc->tun_dev = dev; 377 mtx_lock(&tunmtx); 378 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list); 379 mtx_unlock(&tunmtx); 380 381 ifp = sc->tun_ifp = if_alloc(IFT_PPP); 382 if (ifp == NULL) 383 panic("%s%d: failed to if_alloc() interface.\n", 384 name, dev2unit(dev)); 385 if_initname(ifp, name, dev2unit(dev)); 386 ifp->if_mtu = TUNMTU; 387 ifp->if_ioctl = tunifioctl; 388 ifp->if_output = tunoutput; 389 ifp->if_start = tunstart; 390 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 391 ifp->if_softc = sc; 392 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen); 393 ifp->if_snd.ifq_drv_maxlen = 0; 394 IFQ_SET_READY(&ifp->if_snd); 395 knlist_init_mtx(&sc->tun_rsel.si_note, NULL); 396 397 if_attach(ifp); 398 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 399 dev->si_drv1 = sc; 400 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n", 401 ifp->if_xname, dev2unit(dev)); 402} 403 404static int 405tunopen(struct cdev *dev, int flag, int mode, struct thread *td) 406{ 407 struct ifnet *ifp; 408 struct tun_softc *tp; 409 410 /* 411 * XXXRW: Non-atomic test and set of dev->si_drv1 requires 412 * synchronization. 413 */ 414 tp = dev->si_drv1; 415 if (!tp) { 416 tuncreate(TUNNAME, dev); 417 tp = dev->si_drv1; 418 } 419 420 /* 421 * XXXRW: This use of tun_pid is subject to error due to the 422 * fact that a reference to the tunnel can live beyond the 423 * death of the process that created it. Can we replace this 424 * with a simple busy flag? 425 */ 426 mtx_lock(&tp->tun_mtx); 427 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) { 428 mtx_unlock(&tp->tun_mtx); 429 return (EBUSY); 430 } 431 tp->tun_pid = td->td_proc->p_pid; 432 433 tp->tun_flags |= TUN_OPEN; 434 mtx_unlock(&tp->tun_mtx); 435 ifp = TUN2IFP(tp); 436 if_link_state_change(ifp, LINK_STATE_UP); 437 TUNDEBUG(ifp, "open\n"); 438 439 return (0); 440} 441 442/* 443 * tunclose - close the device - mark i/f down & delete 444 * routing info 445 */ 446static int 447tunclose(struct cdev *dev, int foo, int bar, struct thread *td) 448{ 449 struct tun_softc *tp; 450 struct ifnet *ifp; 451 int s; 452 453 tp = dev->si_drv1; 454 ifp = TUN2IFP(tp); 455 456 mtx_lock(&tp->tun_mtx); 457 tp->tun_flags &= ~TUN_OPEN; 458 tp->tun_pid = 0; 459 mtx_unlock(&tp->tun_mtx); 460 461 /* 462 * junk all pending output 463 */ 464 CURVNET_SET(ifp->if_vnet); 465 s = splimp(); 466 IFQ_PURGE(&ifp->if_snd); 467 splx(s); 468 469 if (ifp->if_flags & IFF_UP) { 470 s = splimp(); 471 if_down(ifp); 472 splx(s); 473 } 474 475 /* Delete all addresses and routes which reference this interface. */ 476 if (ifp->if_drv_flags & IFF_DRV_RUNNING) { 477 struct ifaddr *ifa; 478 479 s = splimp(); 480 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 481 /* deal w/IPv4 PtP destination; unlocked read */ 482 if (ifa->ifa_addr->sa_family == AF_INET) { 483 rtinit(ifa, (int)RTM_DELETE, 484 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0); 485 } else { 486 rtinit(ifa, (int)RTM_DELETE, 0); 487 } 488 } 489 if_purgeaddrs(ifp); 490 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 491 splx(s); 492 } 493 if_link_state_change(ifp, LINK_STATE_DOWN); 494 CURVNET_RESTORE(); 495 496 mtx_lock(&tp->tun_mtx); 497 funsetown(&tp->tun_sigio); 498 selwakeuppri(&tp->tun_rsel, PZERO + 1); 499 KNOTE_UNLOCKED(&tp->tun_rsel.si_note, 0); 500 TUNDEBUG (ifp, "closed\n"); 501 502 cv_broadcast(&tp->tun_cv); 503 mtx_unlock(&tp->tun_mtx); 504 return (0); 505} 506 507static int 508tuninit(struct ifnet *ifp) 509{ 510#ifdef INET 511 struct tun_softc *tp = ifp->if_softc; 512 struct ifaddr *ifa; 513#endif 514 int error = 0; 515 516 TUNDEBUG(ifp, "tuninit\n"); 517 518 ifp->if_flags |= IFF_UP; 519 ifp->if_drv_flags |= IFF_DRV_RUNNING; 520 getmicrotime(&ifp->if_lastchange); 521 522#ifdef INET 523 IF_ADDR_LOCK(ifp); 524 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 525 if (ifa->ifa_addr->sa_family == AF_INET) { 526 struct sockaddr_in *si; 527 528 si = (struct sockaddr_in *)ifa->ifa_addr; 529 mtx_lock(&tp->tun_mtx); 530 if (si->sin_addr.s_addr) 531 tp->tun_flags |= TUN_IASET; 532 533 si = (struct sockaddr_in *)ifa->ifa_dstaddr; 534 if (si && si->sin_addr.s_addr) 535 tp->tun_flags |= TUN_DSTADDR; 536 mtx_unlock(&tp->tun_mtx); 537 } 538 } 539 IF_ADDR_UNLOCK(ifp); 540#endif 541 return (error); 542} 543 544/* 545 * Process an ioctl request. 546 */ 547static int 548tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 549{ 550 struct ifreq *ifr = (struct ifreq *)data; 551 struct tun_softc *tp = ifp->if_softc; 552 struct ifstat *ifs; 553 int error = 0, s; 554 555 s = splimp(); 556 switch(cmd) { 557 case SIOCGIFSTATUS: 558 ifs = (struct ifstat *)data; 559 mtx_lock(&tp->tun_mtx); 560 if (tp->tun_pid) 561 sprintf(ifs->ascii + strlen(ifs->ascii), 562 "\tOpened by PID %d\n", tp->tun_pid); 563 mtx_unlock(&tp->tun_mtx); 564 break; 565 case SIOCSIFADDR: 566 error = tuninit(ifp); 567 TUNDEBUG(ifp, "address set, error=%d\n", error); 568 break; 569 case SIOCSIFDSTADDR: 570 error = tuninit(ifp); 571 TUNDEBUG(ifp, "destination address set, error=%d\n", error); 572 break; 573 case SIOCSIFMTU: 574 ifp->if_mtu = ifr->ifr_mtu; 575 TUNDEBUG(ifp, "mtu set\n"); 576 break; 577 case SIOCSIFFLAGS: 578 case SIOCADDMULTI: 579 case SIOCDELMULTI: 580 break; 581 default: 582 error = EINVAL; 583 } 584 splx(s); 585 return (error); 586} 587 588/* 589 * tunoutput - queue packets from higher level ready to put out. 590 */ 591static int 592tunoutput( 593 struct ifnet *ifp, 594 struct mbuf *m0, 595 struct sockaddr *dst, 596 struct route *ro) 597{ 598 struct tun_softc *tp = ifp->if_softc; 599 u_short cached_tun_flags; 600 int error; 601 u_int32_t af; 602 603 TUNDEBUG (ifp, "tunoutput\n"); 604 605#ifdef MAC 606 error = mac_ifnet_check_transmit(ifp, m0); 607 if (error) { 608 m_freem(m0); 609 return (error); 610 } 611#endif 612 613 /* Could be unlocked read? */ 614 mtx_lock(&tp->tun_mtx); 615 cached_tun_flags = tp->tun_flags; 616 mtx_unlock(&tp->tun_mtx); 617 if ((cached_tun_flags & TUN_READY) != TUN_READY) { 618 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 619 m_freem (m0); 620 return (EHOSTDOWN); 621 } 622 623 if ((ifp->if_flags & IFF_UP) != IFF_UP) { 624 m_freem (m0); 625 return (EHOSTDOWN); 626 } 627 628 /* BPF writes need to be handled specially. */ 629 if (dst->sa_family == AF_UNSPEC) { 630 bcopy(dst->sa_data, &af, sizeof(af)); 631 dst->sa_family = af; 632 } 633 634 if (bpf_peers_present(ifp->if_bpf)) { 635 af = dst->sa_family; 636 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0); 637 } 638 639 /* prepend sockaddr? this may abort if the mbuf allocation fails */ 640 if (cached_tun_flags & TUN_LMODE) { 641 /* allocate space for sockaddr */ 642 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 643 644 /* if allocation failed drop packet */ 645 if (m0 == NULL) { 646 ifp->if_iqdrops++; 647 ifp->if_oerrors++; 648 return (ENOBUFS); 649 } else { 650 bcopy(dst, m0->m_data, dst->sa_len); 651 } 652 } 653 654 if (cached_tun_flags & TUN_IFHEAD) { 655 /* Prepend the address family */ 656 M_PREPEND(m0, 4, M_DONTWAIT); 657 658 /* if allocation failed drop packet */ 659 if (m0 == NULL) { 660 ifp->if_iqdrops++; 661 ifp->if_oerrors++; 662 return (ENOBUFS); 663 } else 664 *(u_int32_t *)m0->m_data = htonl(dst->sa_family); 665 } else { 666#ifdef INET 667 if (dst->sa_family != AF_INET) 668#endif 669 { 670 m_freem(m0); 671 return (EAFNOSUPPORT); 672 } 673 } 674 675 error = (ifp->if_transmit)(ifp, m0); 676 if (error) { 677 ifp->if_collisions++; 678 return (ENOBUFS); 679 } 680 ifp->if_opackets++; 681 return (0); 682} 683 684/* 685 * the cdevsw interface is now pretty minimal. 686 */ 687static int 688tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) 689{ 690 int s; 691 int error; 692 struct tun_softc *tp = dev->si_drv1; 693 struct tuninfo *tunp; 694 695 switch (cmd) { 696 case TUNSIFINFO: 697 tunp = (struct tuninfo *)data; 698 if (tunp->mtu < IF_MINMTU) 699 return (EINVAL); 700 if (TUN2IFP(tp)->if_mtu != tunp->mtu) { 701 error = priv_check(td, PRIV_NET_SETIFMTU); 702 if (error) 703 return (error); 704 } 705 TUN2IFP(tp)->if_mtu = tunp->mtu; 706 TUN2IFP(tp)->if_type = tunp->type; 707 TUN2IFP(tp)->if_baudrate = tunp->baudrate; 708 break; 709 case TUNGIFINFO: 710 tunp = (struct tuninfo *)data; 711 tunp->mtu = TUN2IFP(tp)->if_mtu; 712 tunp->type = TUN2IFP(tp)->if_type; 713 tunp->baudrate = TUN2IFP(tp)->if_baudrate; 714 break; 715 case TUNSDEBUG: 716 tundebug = *(int *)data; 717 break; 718 case TUNGDEBUG: 719 *(int *)data = tundebug; 720 break; 721 case TUNSLMODE: 722 mtx_lock(&tp->tun_mtx); 723 if (*(int *)data) { 724 tp->tun_flags |= TUN_LMODE; 725 tp->tun_flags &= ~TUN_IFHEAD; 726 } else 727 tp->tun_flags &= ~TUN_LMODE; 728 mtx_unlock(&tp->tun_mtx); 729 break; 730 case TUNSIFHEAD: 731 mtx_lock(&tp->tun_mtx); 732 if (*(int *)data) { 733 tp->tun_flags |= TUN_IFHEAD; 734 tp->tun_flags &= ~TUN_LMODE; 735 } else 736 tp->tun_flags &= ~TUN_IFHEAD; 737 mtx_unlock(&tp->tun_mtx); 738 break; 739 case TUNGIFHEAD: 740 /* Could be unlocked read? */ 741 mtx_lock(&tp->tun_mtx); 742 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 743 mtx_unlock(&tp->tun_mtx); 744 break; 745 case TUNSIFMODE: 746 /* deny this if UP */ 747 if (TUN2IFP(tp)->if_flags & IFF_UP) 748 return(EBUSY); 749 750 switch (*(int *)data & ~IFF_MULTICAST) { 751 case IFF_POINTOPOINT: 752 case IFF_BROADCAST: 753 TUN2IFP(tp)->if_flags &= 754 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 755 TUN2IFP(tp)->if_flags |= *(int *)data; 756 break; 757 default: 758 return(EINVAL); 759 } 760 break; 761 case TUNSIFPID: 762 mtx_lock(&tp->tun_mtx); 763 tp->tun_pid = curthread->td_proc->p_pid; 764 mtx_unlock(&tp->tun_mtx); 765 break; 766 case FIONBIO: 767 break; 768 case FIOASYNC: 769 mtx_lock(&tp->tun_mtx); 770 if (*(int *)data) 771 tp->tun_flags |= TUN_ASYNC; 772 else 773 tp->tun_flags &= ~TUN_ASYNC; 774 mtx_unlock(&tp->tun_mtx); 775 break; 776 case FIONREAD: 777 s = splimp(); 778 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) { 779 struct mbuf *mb; 780 IFQ_LOCK(&TUN2IFP(tp)->if_snd); 781 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb); 782 for( *(int *)data = 0; mb != 0; mb = mb->m_next) 783 *(int *)data += mb->m_len; 784 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd); 785 } else 786 *(int *)data = 0; 787 splx(s); 788 break; 789 case FIOSETOWN: 790 return (fsetown(*(int *)data, &tp->tun_sigio)); 791 792 case FIOGETOWN: 793 *(int *)data = fgetown(&tp->tun_sigio); 794 return (0); 795 796 /* This is deprecated, FIOSETOWN should be used instead. */ 797 case TIOCSPGRP: 798 return (fsetown(-(*(int *)data), &tp->tun_sigio)); 799 800 /* This is deprecated, FIOGETOWN should be used instead. */ 801 case TIOCGPGRP: 802 *(int *)data = -fgetown(&tp->tun_sigio); 803 return (0); 804 805 default: 806 return (ENOTTY); 807 } 808 return (0); 809} 810 811/* 812 * The cdevsw read interface - reads a packet at a time, or at 813 * least as much of a packet as can be read. 814 */ 815static int 816tunread(struct cdev *dev, struct uio *uio, int flag) 817{ 818 struct tun_softc *tp = dev->si_drv1; 819 struct ifnet *ifp = TUN2IFP(tp); 820 struct mbuf *m; 821 int error=0, len, s; 822 823 TUNDEBUG (ifp, "read\n"); 824 mtx_lock(&tp->tun_mtx); 825 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 826 mtx_unlock(&tp->tun_mtx); 827 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags); 828 return (EHOSTDOWN); 829 } 830 831 tp->tun_flags &= ~TUN_RWAIT; 832 mtx_unlock(&tp->tun_mtx); 833 834 s = splimp(); 835 do { 836 IFQ_DEQUEUE(&ifp->if_snd, m); 837 if (m == NULL) { 838 if (flag & O_NONBLOCK) { 839 splx(s); 840 return (EWOULDBLOCK); 841 } 842 mtx_lock(&tp->tun_mtx); 843 tp->tun_flags |= TUN_RWAIT; 844 mtx_unlock(&tp->tun_mtx); 845 if ((error = tsleep(tp, PCATCH | (PZERO + 1), 846 "tunread", 0)) != 0) { 847 splx(s); 848 return (error); 849 } 850 } 851 } while (m == NULL); 852 splx(s); 853 854 while (m && uio->uio_resid > 0 && error == 0) { 855 len = min(uio->uio_resid, m->m_len); 856 if (len != 0) 857 error = uiomove(mtod(m, void *), len, uio); 858 m = m_free(m); 859 } 860 861 if (m) { 862 TUNDEBUG(ifp, "Dropping mbuf\n"); 863 m_freem(m); 864 } 865 return (error); 866} 867 868/* 869 * the cdevsw write interface - an atomic write is a packet - or else! 870 */ 871static int 872tunwrite(struct cdev *dev, struct uio *uio, int flag) 873{ 874 struct tun_softc *tp = dev->si_drv1; 875 struct ifnet *ifp = TUN2IFP(tp); 876 struct mbuf *m; 877 int error = 0; 878 uint32_t family; 879 int isr; 880 881 TUNDEBUG(ifp, "tunwrite\n"); 882 883 if ((ifp->if_flags & IFF_UP) != IFF_UP) 884 /* ignore silently */ 885 return (0); 886 887 if (uio->uio_resid == 0) 888 return (0); 889 890 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) { 891 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid); 892 return (EIO); 893 } 894 895 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) { 896 ifp->if_ierrors++; 897 return (error); 898 } 899 900 m->m_pkthdr.rcvif = ifp; 901#ifdef MAC 902 mac_ifnet_create_mbuf(ifp, m); 903#endif 904 905 /* Could be unlocked read? */ 906 mtx_lock(&tp->tun_mtx); 907 if (tp->tun_flags & TUN_IFHEAD) { 908 mtx_unlock(&tp->tun_mtx); 909 if (m->m_len < sizeof(family) && 910 (m = m_pullup(m, sizeof(family))) == NULL) 911 return (ENOBUFS); 912 family = ntohl(*mtod(m, u_int32_t *)); 913 m_adj(m, sizeof(family)); 914 } else { 915 mtx_unlock(&tp->tun_mtx); 916 family = AF_INET; 917 } 918 919 BPF_MTAP2(ifp, &family, sizeof(family), m); 920 921 switch (family) { 922#ifdef INET 923 case AF_INET: 924 isr = NETISR_IP; 925 break; 926#endif 927#ifdef INET6 928 case AF_INET6: 929 isr = NETISR_IPV6; 930 break; 931#endif 932#ifdef IPX 933 case AF_IPX: 934 isr = NETISR_IPX; 935 break; 936#endif 937#ifdef NETATALK 938 case AF_APPLETALK: 939 isr = NETISR_ATALK2; 940 break; 941#endif 942 default: 943 m_freem(m); 944 return (EAFNOSUPPORT); 945 } 946 /* First chunk of an mbuf contains good junk */ 947 if (harvest.point_to_point) 948 random_harvest(m, 16, 3, 0, RANDOM_NET); 949 ifp->if_ibytes += m->m_pkthdr.len; 950 ifp->if_ipackets++; 951 CURVNET_SET(ifp->if_vnet); 952 netisr_dispatch(isr, m); 953 CURVNET_RESTORE(); 954 return (0); 955} 956 957/* 958 * tunpoll - the poll interface, this is only useful on reads 959 * really. The write detect always returns true, write never blocks 960 * anyway, it either accepts the packet or drops it. 961 */ 962static int 963tunpoll(struct cdev *dev, int events, struct thread *td) 964{ 965 int s; 966 struct tun_softc *tp = dev->si_drv1; 967 struct ifnet *ifp = TUN2IFP(tp); 968 int revents = 0; 969 struct mbuf *m; 970 971 s = splimp(); 972 TUNDEBUG(ifp, "tunpoll\n"); 973 974 if (events & (POLLIN | POLLRDNORM)) { 975 IFQ_LOCK(&ifp->if_snd); 976 IFQ_POLL_NOLOCK(&ifp->if_snd, m); 977 if (m != NULL) { 978 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len); 979 revents |= events & (POLLIN | POLLRDNORM); 980 } else { 981 TUNDEBUG(ifp, "tunpoll waiting\n"); 982 selrecord(td, &tp->tun_rsel); 983 } 984 IFQ_UNLOCK(&ifp->if_snd); 985 } 986 if (events & (POLLOUT | POLLWRNORM)) 987 revents |= events & (POLLOUT | POLLWRNORM); 988 989 splx(s); 990 return (revents); 991} 992 993/* 994 * tunkqfilter - support for the kevent() system call. 995 */ 996static int 997tunkqfilter(struct cdev *dev, struct knote *kn) 998{ 999 int s; 1000 struct tun_softc *tp = dev->si_drv1; 1001 struct ifnet *ifp = TUN2IFP(tp); 1002 1003 s = splimp(); 1004 switch(kn->kn_filter) { 1005 case EVFILT_READ: 1006 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n", 1007 ifp->if_xname, dev2unit(dev)); 1008 kn->kn_fop = &tun_read_filterops; 1009 break; 1010 1011 case EVFILT_WRITE: 1012 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n", 1013 ifp->if_xname, dev2unit(dev)); 1014 kn->kn_fop = &tun_write_filterops; 1015 break; 1016 1017 default: 1018 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n", 1019 ifp->if_xname, dev2unit(dev)); 1020 splx(s); 1021 return(EINVAL); 1022 } 1023 splx(s); 1024 1025 kn->kn_hook = (caddr_t) dev; 1026 knlist_add(&tp->tun_rsel.si_note, kn, 0); 1027 1028 return (0); 1029} 1030 1031/* 1032 * Return true of there is data in the interface queue. 1033 */ 1034static int 1035tunkqread(struct knote *kn, long hint) 1036{ 1037 int ret, s; 1038 struct cdev *dev = (struct cdev *)(kn->kn_hook); 1039 struct tun_softc *tp = dev->si_drv1; 1040 struct ifnet *ifp = TUN2IFP(tp); 1041 1042 s = splimp(); 1043 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) { 1044 TUNDEBUG(ifp, 1045 "%s have data in the queue. Len = %d, minor = %#x\n", 1046 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev)); 1047 ret = 1; 1048 } else { 1049 TUNDEBUG(ifp, 1050 "%s waiting for data, minor = %#x\n", ifp->if_xname, 1051 dev2unit(dev)); 1052 ret = 0; 1053 } 1054 splx(s); 1055 1056 return (ret); 1057} 1058 1059/* 1060 * Always can write, always return MTU in kn->data. 1061 */ 1062static int 1063tunkqwrite(struct knote *kn, long hint) 1064{ 1065 int s; 1066 struct tun_softc *tp = ((struct cdev *)kn->kn_hook)->si_drv1; 1067 struct ifnet *ifp = TUN2IFP(tp); 1068 1069 s = splimp(); 1070 kn->kn_data = ifp->if_mtu; 1071 splx(s); 1072 1073 return (1); 1074} 1075 1076static void 1077tunkqdetach(struct knote *kn) 1078{ 1079 struct tun_softc *tp = ((struct cdev *)kn->kn_hook)->si_drv1; 1080 1081 knlist_remove(&tp->tun_rsel.si_note, kn, 0); 1082} 1083