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: src/sys/net/if_tun.c,v 1.74.2.8 2002/02/13 00:43:11 dillon Exp $ 17 * $DragonFly: src/sys/net/tun/if_tun.c,v 1.37 2008/06/05 18:06:32 swildner Exp $ 18 */ 19 20 #include "use_tun.h" 21 #include "opt_atalk.h" 22 #include "opt_inet.h" 23 #include "opt_inet6.h" 24 #include "opt_ipx.h" 25 26 #include <sys/param.h> 27 #include <sys/proc.h> 28 #include <sys/priv.h> 29 #include <sys/systm.h> 30 #include <sys/mbuf.h> 31 #include <sys/socket.h> 32 #include <sys/conf.h> 33 #include <sys/device.h> 34 #include <sys/filio.h> 35 #include <sys/sockio.h> 36 #include <sys/thread2.h> 37 #include <sys/ttycom.h> 38 #include <sys/signalvar.h> 39 #include <sys/filedesc.h> 40 #include <sys/kernel.h> 41 #include <sys/sysctl.h> 42 #include <sys/uio.h> 43 #include <sys/vnode.h> 44 #include <sys/malloc.h> 45 46 #include <sys/mplock2.h> 47 48 #include <net/if.h> 49 #include <net/if_types.h> 50 #include <net/ifq_var.h> 51 #include <net/netisr.h> 52 #include <net/route.h> 53 #include <sys/devfs.h> 54 55 #ifdef INET 56 #include <netinet/in.h> 57 #endif 58 59 #include <net/bpf.h> 60 61 #include "if_tunvar.h" 62 #include "if_tun.h" 63 64 static MALLOC_DEFINE(M_TUN, "tun", "Tunnel Interface"); 65 66 static void tunattach (void *); 67 PSEUDO_SET(tunattach, if_tun); 68 69 static void tuncreate (cdev_t dev); 70 71 #define TUNDEBUG if (tundebug) if_printf 72 static int tundebug = 0; 73 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, ""); 74 75 static int tunoutput (struct ifnet *, struct mbuf *, struct sockaddr *, 76 struct rtentry *rt); 77 static int tunifioctl (struct ifnet *, u_long, caddr_t, struct ucred *); 78 static int tuninit (struct ifnet *); 79 static void tunstart(struct ifnet *); 80 static void tun_filter_detach(struct knote *); 81 static int tun_filter_read(struct knote *, long); 82 static int tun_filter_write(struct knote *, long); 83 84 static d_open_t tunopen; 85 static d_close_t tunclose; 86 static d_read_t tunread; 87 static d_write_t tunwrite; 88 static d_ioctl_t tunioctl; 89 static d_kqfilter_t tunkqfilter; 90 91 static d_clone_t tunclone; 92 DEVFS_DECLARE_CLONE_BITMAP(tun); 93 94 #if NTUN <= 1 95 #define TUN_PREALLOCATED_UNITS 4 96 #else 97 #define TUN_PREALLOCATED_UNITS NTUN 98 #endif 99 100 #define CDEV_MAJOR 52 101 static struct dev_ops tun_ops = { 102 { "tun", CDEV_MAJOR, 0 }, 103 .d_open = tunopen, 104 .d_close = tunclose, 105 .d_read = tunread, 106 .d_write = tunwrite, 107 .d_ioctl = tunioctl, 108 .d_kqfilter = tunkqfilter 109 }; 110 111 static void 112 tunattach(void *dummy) 113 { 114 int i; 115 make_autoclone_dev(&tun_ops, &DEVFS_CLONE_BITMAP(tun), 116 tunclone, UID_UUCP, GID_DIALER, 0600, "tun"); 117 for (i = 0; i < TUN_PREALLOCATED_UNITS; i++) { 118 make_dev(&tun_ops, i, UID_UUCP, GID_DIALER, 0600, "tun%d", i); 119 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(tun), i); 120 } 121 /* Doesn't need uninit because unloading is not possible, see PSEUDO_SET */ 122 } 123 124 static int 125 tunclone(struct dev_clone_args *ap) 126 { 127 int unit; 128 129 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(tun), 0); 130 ap->a_dev = make_only_dev(&tun_ops, unit, UID_UUCP, GID_DIALER, 0600, 131 "tun%d", unit); 132 133 return 0; 134 } 135 136 static void 137 tuncreate(cdev_t dev) 138 { 139 struct tun_softc *sc; 140 struct ifnet *ifp; 141 142 #if 0 143 dev = make_dev(&tun_ops, minor(dev), 144 UID_UUCP, GID_DIALER, 0600, "tun%d", lminor(dev)); 145 #endif 146 147 MALLOC(sc, struct tun_softc *, sizeof(*sc), M_TUN, M_WAITOK | M_ZERO); 148 sc->tun_flags = TUN_INITED; 149 150 ifp = &sc->tun_if; 151 if_initname(ifp, "tun", lminor(dev)); 152 ifp->if_mtu = TUNMTU; 153 ifp->if_ioctl = tunifioctl; 154 ifp->if_output = tunoutput; 155 ifp->if_start = tunstart; 156 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 157 ifp->if_type = IFT_PPP; 158 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen); 159 ifq_set_ready(&ifp->if_snd); 160 ifp->if_softc = sc; 161 if_attach(ifp, NULL); 162 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 163 dev->si_drv1 = sc; 164 } 165 166 /* 167 * tunnel open - must be superuser & the device must be 168 * configured in 169 */ 170 static int 171 tunopen(struct dev_open_args *ap) 172 { 173 cdev_t dev = ap->a_head.a_dev; 174 struct ifnet *ifp; 175 struct tun_softc *tp; 176 int error; 177 178 if ((error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) != 0) 179 return (error); 180 181 tp = dev->si_drv1; 182 if (!tp) { 183 tuncreate(dev); 184 tp = dev->si_drv1; 185 } 186 if (tp->tun_flags & TUN_OPEN) 187 return EBUSY; 188 tp->tun_pid = curproc->p_pid; 189 ifp = &tp->tun_if; 190 tp->tun_flags |= TUN_OPEN; 191 TUNDEBUG(ifp, "open\n"); 192 return (0); 193 } 194 195 /* 196 * tunclose - close the device - mark i/f down & delete 197 * routing info 198 */ 199 static int 200 tunclose(struct dev_close_args *ap) 201 { 202 cdev_t dev = ap->a_head.a_dev; 203 struct tun_softc *tp; 204 struct ifnet *ifp; 205 206 tp = dev->si_drv1; 207 ifp = &tp->tun_if; 208 209 tp->tun_flags &= ~TUN_OPEN; 210 tp->tun_pid = 0; 211 212 /* Junk all pending output. */ 213 ifq_purge(&ifp->if_snd); 214 215 if (ifp->if_flags & IFF_UP) 216 if_down(ifp); 217 ifp->if_flags &= ~IFF_RUNNING; 218 if_purgeaddrs_nolink(ifp); 219 220 funsetown(tp->tun_sigio); 221 KNOTE(&tp->tun_rkq.ki_note, 0); 222 223 TUNDEBUG(ifp, "closed\n"); 224 #if 0 225 if (dev->si_uminor >= TUN_PREALLOCATED_UNITS) { 226 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(tun), dev->si_uminor); 227 } 228 #endif 229 return (0); 230 } 231 232 static int 233 tuninit(struct ifnet *ifp) 234 { 235 struct tun_softc *tp = ifp->if_softc; 236 struct ifaddr_container *ifac; 237 int error = 0; 238 239 TUNDEBUG(ifp, "tuninit\n"); 240 241 ifp->if_flags |= IFF_UP | IFF_RUNNING; 242 getmicrotime(&ifp->if_lastchange); 243 244 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 245 struct ifaddr *ifa = ifac->ifa; 246 247 if (ifa->ifa_addr == NULL) { 248 error = EFAULT; 249 /* XXX: Should maybe return straight off? */ 250 } else { 251 #ifdef INET 252 if (ifa->ifa_addr->sa_family == AF_INET) { 253 struct sockaddr_in *si; 254 255 si = (struct sockaddr_in *)ifa->ifa_addr; 256 if (si->sin_addr.s_addr) 257 tp->tun_flags |= TUN_IASET; 258 } 259 #endif 260 } 261 } 262 return (error); 263 } 264 265 /* 266 * Process an ioctl request. 267 * 268 * MPSAFE 269 */ 270 int 271 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 272 { 273 struct ifreq *ifr = (struct ifreq *)data; 274 struct tun_softc *tp = ifp->if_softc; 275 struct ifstat *ifs; 276 int error = 0; 277 278 switch(cmd) { 279 case SIOCGIFSTATUS: 280 ifs = (struct ifstat *)data; 281 if (tp->tun_pid) 282 ksprintf(ifs->ascii + strlen(ifs->ascii), 283 "\tOpened by PID %d\n", tp->tun_pid); 284 break; 285 case SIOCSIFADDR: 286 error = tuninit(ifp); 287 TUNDEBUG(ifp, "address set, error=%d\n", error); 288 break; 289 case SIOCSIFDSTADDR: 290 error = tuninit(ifp); 291 TUNDEBUG(ifp, "destination address set, error=%d\n", error); 292 break; 293 case SIOCSIFMTU: 294 ifp->if_mtu = ifr->ifr_mtu; 295 TUNDEBUG(ifp, "mtu set\n"); 296 break; 297 case SIOCSIFFLAGS: 298 case SIOCADDMULTI: 299 case SIOCDELMULTI: 300 break; 301 default: 302 error = EINVAL; 303 } 304 return (error); 305 } 306 307 /* 308 * tunoutput - queue packets from higher level ready to put out. 309 * 310 * MPSAFE 311 */ 312 static int 313 tunoutput_serialized(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 314 struct rtentry *rt) 315 { 316 struct tun_softc *tp = ifp->if_softc; 317 int error; 318 struct altq_pktattr pktattr; 319 320 TUNDEBUG(ifp, "tunoutput\n"); 321 322 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 323 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags); 324 m_freem (m0); 325 return EHOSTDOWN; 326 } 327 328 /* 329 * if the queueing discipline needs packet classification, 330 * do it before prepending link headers. 331 */ 332 ifq_classify(&ifp->if_snd, m0, dst->sa_family, &pktattr); 333 334 /* BPF write needs to be handled specially */ 335 if (dst->sa_family == AF_UNSPEC) { 336 dst->sa_family = *(mtod(m0, int *)); 337 m0->m_len -= sizeof(int); 338 m0->m_pkthdr.len -= sizeof(int); 339 m0->m_data += sizeof(int); 340 } 341 342 if (ifp->if_bpf) { 343 /* 344 * We need to prepend the address family as 345 * a four byte field. 346 */ 347 uint32_t af = dst->sa_family; 348 349 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af)); 350 } 351 352 /* prepend sockaddr? this may abort if the mbuf allocation fails */ 353 if (tp->tun_flags & TUN_LMODE) { 354 /* allocate space for sockaddr */ 355 M_PREPEND(m0, dst->sa_len, MB_DONTWAIT); 356 357 /* if allocation failed drop packet */ 358 if (m0 == NULL){ 359 IF_DROP(&ifp->if_snd); 360 ifp->if_oerrors++; 361 return (ENOBUFS); 362 } else { 363 bcopy(dst, m0->m_data, dst->sa_len); 364 } 365 } 366 367 if (tp->tun_flags & TUN_IFHEAD) { 368 /* Prepend the address family */ 369 M_PREPEND(m0, 4, MB_DONTWAIT); 370 371 /* if allocation failed drop packet */ 372 if (m0 == NULL){ 373 IF_DROP(&ifp->if_snd); 374 ifp->if_oerrors++; 375 return ENOBUFS; 376 } else 377 *(u_int32_t *)m0->m_data = htonl(dst->sa_family); 378 } else { 379 #ifdef INET 380 if (dst->sa_family != AF_INET) 381 #endif 382 { 383 m_freem(m0); 384 return EAFNOSUPPORT; 385 } 386 } 387 388 error = ifq_handoff(ifp, m0, &pktattr); 389 if (error) { 390 ifp->if_collisions++; 391 } else { 392 ifp->if_opackets++; 393 if (tp->tun_flags & TUN_RWAIT) { 394 tp->tun_flags &= ~TUN_RWAIT; 395 wakeup((caddr_t)tp); 396 } 397 get_mplock(); 398 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) 399 pgsigio(tp->tun_sigio, SIGIO, 0); 400 rel_mplock(); 401 ifnet_deserialize_all(ifp); 402 KNOTE(&tp->tun_rkq.ki_note, 0); 403 ifnet_serialize_all(ifp); 404 } 405 return (error); 406 } 407 408 static int 409 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 410 struct rtentry *rt) 411 { 412 int error; 413 414 ifnet_serialize_all(ifp); 415 error = tunoutput_serialized(ifp, m0, dst, rt); 416 ifnet_deserialize_all(ifp); 417 418 return error; 419 } 420 421 /* 422 * the ops interface is now pretty minimal. 423 */ 424 static int 425 tunioctl(struct dev_ioctl_args *ap) 426 { 427 cdev_t dev = ap->a_head.a_dev; 428 struct tun_softc *tp = dev->si_drv1; 429 struct tuninfo *tunp; 430 431 switch (ap->a_cmd) { 432 case TUNSIFINFO: 433 tunp = (struct tuninfo *)ap->a_data; 434 if (tunp->mtu < IF_MINMTU) 435 return (EINVAL); 436 tp->tun_if.if_mtu = tunp->mtu; 437 tp->tun_if.if_type = tunp->type; 438 tp->tun_if.if_baudrate = tunp->baudrate; 439 break; 440 case TUNGIFINFO: 441 tunp = (struct tuninfo *)ap->a_data; 442 tunp->mtu = tp->tun_if.if_mtu; 443 tunp->type = tp->tun_if.if_type; 444 tunp->baudrate = tp->tun_if.if_baudrate; 445 break; 446 case TUNSDEBUG: 447 tundebug = *(int *)ap->a_data; 448 break; 449 case TUNGDEBUG: 450 *(int *)ap->a_data = tundebug; 451 break; 452 case TUNSLMODE: 453 if (*(int *)ap->a_data) { 454 tp->tun_flags |= TUN_LMODE; 455 tp->tun_flags &= ~TUN_IFHEAD; 456 } else 457 tp->tun_flags &= ~TUN_LMODE; 458 break; 459 case TUNSIFHEAD: 460 if (*(int *)ap->a_data) { 461 tp->tun_flags |= TUN_IFHEAD; 462 tp->tun_flags &= ~TUN_LMODE; 463 } else 464 tp->tun_flags &= ~TUN_IFHEAD; 465 break; 466 case TUNGIFHEAD: 467 *(int *)ap->a_data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 468 break; 469 case TUNSIFMODE: 470 /* deny this if UP */ 471 if (tp->tun_if.if_flags & IFF_UP) 472 return(EBUSY); 473 474 switch (*(int *)ap->a_data & ~IFF_MULTICAST) { 475 case IFF_POINTOPOINT: 476 case IFF_BROADCAST: 477 tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT); 478 tp->tun_if.if_flags |= *(int *)ap->a_data; 479 break; 480 default: 481 return(EINVAL); 482 } 483 break; 484 case TUNSIFPID: 485 tp->tun_pid = curproc->p_pid; 486 break; 487 case FIOASYNC: 488 if (*(int *)ap->a_data) 489 tp->tun_flags |= TUN_ASYNC; 490 else 491 tp->tun_flags &= ~TUN_ASYNC; 492 break; 493 case FIONREAD: 494 if (!ifq_is_empty(&tp->tun_if.if_snd)) { 495 struct mbuf *mb; 496 497 mb = ifq_poll(&tp->tun_if.if_snd); 498 for( *(int *)ap->a_data = 0; mb != 0; mb = mb->m_next) 499 *(int *)ap->a_data += mb->m_len; 500 } else { 501 *(int *)ap->a_data = 0; 502 } 503 break; 504 case FIOSETOWN: 505 return (fsetown(*(int *)ap->a_data, &tp->tun_sigio)); 506 507 case FIOGETOWN: 508 *(int *)ap->a_data = fgetown(tp->tun_sigio); 509 return (0); 510 511 /* This is deprecated, FIOSETOWN should be used instead. */ 512 case TIOCSPGRP: 513 return (fsetown(-(*(int *)ap->a_data), &tp->tun_sigio)); 514 515 /* This is deprecated, FIOGETOWN should be used instead. */ 516 case TIOCGPGRP: 517 *(int *)ap->a_data = -fgetown(tp->tun_sigio); 518 return (0); 519 520 default: 521 return (ENOTTY); 522 } 523 return (0); 524 } 525 526 /* 527 * The ops read interface - reads a packet at a time, or at 528 * least as much of a packet as can be read. 529 */ 530 static int 531 tunread(struct dev_read_args *ap) 532 { 533 cdev_t dev = ap->a_head.a_dev; 534 struct uio *uio = ap->a_uio; 535 struct tun_softc *tp = dev->si_drv1; 536 struct ifnet *ifp = &tp->tun_if; 537 struct mbuf *m0; 538 int error=0, len; 539 540 TUNDEBUG(ifp, "read\n"); 541 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 542 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags); 543 return EHOSTDOWN; 544 } 545 546 tp->tun_flags &= ~TUN_RWAIT; 547 548 ifnet_serialize_all(ifp); 549 550 while ((m0 = ifq_dequeue(&ifp->if_snd, NULL)) == NULL) { 551 if (ap->a_ioflag & IO_NDELAY) { 552 ifnet_deserialize_all(ifp); 553 return EWOULDBLOCK; 554 } 555 tp->tun_flags |= TUN_RWAIT; 556 ifnet_deserialize_all(ifp); 557 if ((error = tsleep(tp, PCATCH, "tunread", 0)) != 0) 558 return error; 559 ifnet_serialize_all(ifp); 560 } 561 562 ifnet_deserialize_all(ifp); 563 564 while (m0 && uio->uio_resid > 0 && error == 0) { 565 len = (int)szmin(uio->uio_resid, m0->m_len); 566 if (len != 0) 567 error = uiomove(mtod(m0, caddr_t), (size_t)len, uio); 568 m0 = m_free(m0); 569 } 570 571 if (m0) { 572 TUNDEBUG(ifp, "Dropping mbuf\n"); 573 m_freem(m0); 574 } 575 return error; 576 } 577 578 /* 579 * the ops write interface - an atomic write is a packet - or else! 580 */ 581 static int 582 tunwrite(struct dev_write_args *ap) 583 { 584 cdev_t dev = ap->a_head.a_dev; 585 struct uio *uio = ap->a_uio; 586 struct tun_softc *tp = dev->si_drv1; 587 struct ifnet *ifp = &tp->tun_if; 588 struct mbuf *top, **mp, *m; 589 int error=0; 590 size_t tlen, mlen; 591 uint32_t family; 592 int isr; 593 594 TUNDEBUG(ifp, "tunwrite\n"); 595 596 if (uio->uio_resid == 0) 597 return 0; 598 599 if (uio->uio_resid > TUNMRU) { 600 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid); 601 return EIO; 602 } 603 tlen = uio->uio_resid; 604 605 /* get a header mbuf */ 606 MGETHDR(m, MB_DONTWAIT, MT_DATA); 607 if (m == NULL) 608 return ENOBUFS; 609 mlen = MHLEN; 610 611 top = 0; 612 mp = ⊤ 613 while (error == 0 && uio->uio_resid > 0) { 614 m->m_len = (int)szmin(mlen, uio->uio_resid); 615 error = uiomove(mtod (m, caddr_t), (size_t)m->m_len, uio); 616 *mp = m; 617 mp = &m->m_next; 618 if (uio->uio_resid > 0) { 619 MGET (m, MB_DONTWAIT, MT_DATA); 620 if (m == 0) { 621 error = ENOBUFS; 622 break; 623 } 624 mlen = MLEN; 625 } 626 } 627 if (error) { 628 if (top) 629 m_freem (top); 630 ifp->if_ierrors++; 631 return error; 632 } 633 634 top->m_pkthdr.len = (int)tlen; 635 top->m_pkthdr.rcvif = ifp; 636 637 if (ifp->if_bpf) { 638 if (tp->tun_flags & TUN_IFHEAD) { 639 /* 640 * Conveniently, we already have a 4-byte address 641 * family prepended to our packet ! 642 * Inconveniently, it's in the wrong byte order ! 643 */ 644 if ((top = m_pullup(top, sizeof(family))) == NULL) 645 return ENOBUFS; 646 *mtod(top, u_int32_t *) = 647 ntohl(*mtod(top, u_int32_t *)); 648 bpf_mtap(ifp->if_bpf, top); 649 *mtod(top, u_int32_t *) = 650 htonl(*mtod(top, u_int32_t *)); 651 } else { 652 /* 653 * We need to prepend the address family as 654 * a four byte field. 655 */ 656 static const uint32_t af = AF_INET; 657 658 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af)); 659 } 660 } 661 662 if (tp->tun_flags & TUN_IFHEAD) { 663 if (top->m_len < sizeof(family) && 664 (top = m_pullup(top, sizeof(family))) == NULL) 665 return ENOBUFS; 666 family = ntohl(*mtod(top, u_int32_t *)); 667 m_adj(top, sizeof(family)); 668 } else 669 family = AF_INET; 670 671 ifp->if_ibytes += top->m_pkthdr.len; 672 ifp->if_ipackets++; 673 674 switch (family) { 675 #ifdef INET 676 case AF_INET: 677 isr = NETISR_IP; 678 break; 679 #endif 680 #ifdef INET6 681 case AF_INET6: 682 isr = NETISR_IPV6; 683 break; 684 #endif 685 #ifdef IPX 686 case AF_IPX: 687 isr = NETISR_IPX; 688 break; 689 #endif 690 #ifdef NETATALK 691 case AF_APPLETALK: 692 isr = NETISR_ATALK2; 693 break; 694 #endif 695 default: 696 m_freem(m); 697 return (EAFNOSUPPORT); 698 } 699 700 netisr_dispatch(isr, top); 701 return (0); 702 } 703 704 static struct filterops tun_read_filtops = 705 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_read }; 706 static struct filterops tun_write_filtops = 707 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_write }; 708 709 static int 710 tunkqfilter(struct dev_kqfilter_args *ap) 711 { 712 cdev_t dev = ap->a_head.a_dev; 713 struct tun_softc *tp = dev->si_drv1; 714 struct knote *kn = ap->a_kn; 715 struct klist *klist; 716 717 ap->a_result = 0; 718 ifnet_serialize_all(&tp->tun_if); 719 720 switch (kn->kn_filter) { 721 case EVFILT_READ: 722 kn->kn_fop = &tun_read_filtops; 723 kn->kn_hook = (caddr_t)tp; 724 break; 725 case EVFILT_WRITE: 726 kn->kn_fop = &tun_write_filtops; 727 kn->kn_hook = (caddr_t)tp; 728 break; 729 default: 730 ifnet_deserialize_all(&tp->tun_if); 731 ap->a_result = EOPNOTSUPP; 732 return (0); 733 } 734 735 klist = &tp->tun_rkq.ki_note; 736 knote_insert(klist, kn); 737 ifnet_deserialize_all(&tp->tun_if); 738 739 return (0); 740 } 741 742 static void 743 tun_filter_detach(struct knote *kn) 744 { 745 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook; 746 struct klist *klist = &tp->tun_rkq.ki_note; 747 748 knote_remove(klist, kn); 749 } 750 751 static int 752 tun_filter_write(struct knote *kn, long hint) 753 { 754 /* Always ready for a write */ 755 return (1); 756 } 757 758 static int 759 tun_filter_read(struct knote *kn, long hint) 760 { 761 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook; 762 int ready = 0; 763 764 ifnet_serialize_all(&tp->tun_if); 765 if (!ifq_is_empty(&tp->tun_if.if_snd)) 766 ready = 1; 767 ifnet_deserialize_all(&tp->tun_if); 768 769 return (ready); 770 } 771 772 /* 773 * Start packet transmission on the interface. 774 * when the interface queue is rate-limited by ALTQ, 775 * if_start is needed to drain packets from the queue in order 776 * to notify readers when outgoing packets become ready. 777 */ 778 static void 779 tunstart(struct ifnet *ifp) 780 { 781 struct tun_softc *tp = ifp->if_softc; 782 struct mbuf *m; 783 784 if (!ifq_is_enabled(&ifp->if_snd)) 785 return; 786 787 m = ifq_poll(&ifp->if_snd); 788 if (m != NULL) { 789 if (tp->tun_flags & TUN_RWAIT) { 790 tp->tun_flags &= ~TUN_RWAIT; 791 wakeup((caddr_t)tp); 792 } 793 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) 794 pgsigio(tp->tun_sigio, SIGIO, 0); 795 ifnet_deserialize_tx(ifp); 796 KNOTE(&tp->tun_rkq.ki_note, 0); 797 ifnet_serialize_tx(ifp); 798 } 799 } 800