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 */ 18 19 #include "use_tun.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/proc.h> 26 #include <sys/priv.h> 27 #include <sys/systm.h> 28 #include <sys/mbuf.h> 29 #include <sys/socket.h> 30 #include <sys/conf.h> 31 #include <sys/device.h> 32 #include <sys/filio.h> 33 #include <sys/sockio.h> 34 #include <sys/thread2.h> 35 #include <sys/ttycom.h> 36 #include <sys/signalvar.h> 37 #include <sys/filedesc.h> 38 #include <sys/kernel.h> 39 #include <sys/sysctl.h> 40 #include <sys/uio.h> 41 #include <sys/vnode.h> 42 #include <sys/malloc.h> 43 44 #include <sys/mplock2.h> 45 46 #include <net/if.h> 47 #include <net/if_types.h> 48 #include <net/ifq_var.h> 49 #include <net/netisr.h> 50 #include <net/route.h> 51 #include <sys/devfs.h> 52 53 #ifdef INET 54 #include <netinet/in.h> 55 #endif 56 57 #include <net/bpf.h> 58 59 #include "if_tunvar.h" 60 #include "if_tun.h" 61 62 static MALLOC_DEFINE(M_TUN, "tun", "Tunnel Interface"); 63 64 static void tunattach (void *); 65 PSEUDO_SET(tunattach, if_tun); 66 67 static void tuncreate (cdev_t dev); 68 69 #define TUNDEBUG if (tundebug) if_printf 70 static int tundebug = 0; 71 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, 72 "Enable debug output"); 73 74 static int tunoutput (struct ifnet *, struct mbuf *, struct sockaddr *, 75 struct rtentry *rt); 76 static int tunifioctl (struct ifnet *, u_long, caddr_t, struct ucred *); 77 static int tuninit (struct ifnet *); 78 static void tunstart(struct ifnet *, struct ifaltq_subque *); 79 static void tun_filter_detach(struct knote *); 80 static int tun_filter_read(struct knote *, long); 81 static int tun_filter_write(struct knote *, long); 82 83 static d_open_t tunopen; 84 static d_close_t tunclose; 85 static d_read_t tunread; 86 static d_write_t tunwrite; 87 static d_ioctl_t tunioctl; 88 static d_kqfilter_t tunkqfilter; 89 90 static d_clone_t tunclone; 91 DEVFS_DECLARE_CLONE_BITMAP(tun); 92 93 #if NTUN <= 1 94 #define TUN_PREALLOCATED_UNITS 4 95 #else 96 #define TUN_PREALLOCATED_UNITS NTUN 97 #endif 98 99 static struct dev_ops tun_ops = { 100 { "tun", 0, 0 }, 101 .d_open = tunopen, 102 .d_close = tunclose, 103 .d_read = tunread, 104 .d_write = tunwrite, 105 .d_ioctl = tunioctl, 106 .d_kqfilter = tunkqfilter 107 }; 108 109 static void 110 tunattach(void *dummy) 111 { 112 int i; 113 make_autoclone_dev(&tun_ops, &DEVFS_CLONE_BITMAP(tun), 114 tunclone, UID_UUCP, GID_DIALER, 0600, "tun"); 115 for (i = 0; i < TUN_PREALLOCATED_UNITS; i++) { 116 make_dev(&tun_ops, i, UID_UUCP, GID_DIALER, 0600, "tun%d", i); 117 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(tun), i); 118 } 119 /* Doesn't need uninit because unloading is not possible, see PSEUDO_SET */ 120 } 121 122 static int 123 tunclone(struct dev_clone_args *ap) 124 { 125 int unit; 126 127 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(tun), 0); 128 ap->a_dev = make_only_dev(&tun_ops, unit, UID_UUCP, GID_DIALER, 0600, 129 "tun%d", unit); 130 131 return 0; 132 } 133 134 static void 135 tuncreate(cdev_t dev) 136 { 137 struct tun_softc *sc; 138 struct ifnet *ifp; 139 140 #if 0 141 dev = make_dev(&tun_ops, minor(dev), 142 UID_UUCP, GID_DIALER, 0600, "tun%d", lminor(dev)); 143 #endif 144 145 sc = kmalloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO); 146 sc->tun_flags = TUN_INITED; 147 148 ifp = &sc->tun_if; 149 if_initname(ifp, "tun", lminor(dev)); 150 ifp->if_mtu = TUNMTU; 151 ifp->if_ioctl = tunifioctl; 152 ifp->if_output = tunoutput; 153 ifp->if_start = tunstart; 154 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST; 155 ifp->if_type = IFT_PPP; 156 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen); 157 ifq_set_ready(&ifp->if_snd); 158 ifp->if_softc = sc; 159 if_attach(ifp, NULL); 160 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 161 dev->si_drv1 = sc; 162 } 163 164 /* 165 * tunnel open - must be superuser & the device must be 166 * configured in 167 */ 168 static int 169 tunopen(struct dev_open_args *ap) 170 { 171 cdev_t dev = ap->a_head.a_dev; 172 struct ifnet *ifp; 173 struct tun_softc *tp; 174 int error; 175 176 if ((error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) != 0) 177 return (error); 178 179 tp = dev->si_drv1; 180 if (!tp) { 181 tuncreate(dev); 182 tp = dev->si_drv1; 183 } 184 if (tp->tun_flags & TUN_OPEN) 185 return EBUSY; 186 tp->tun_pid = curproc->p_pid; 187 ifp = &tp->tun_if; 188 tp->tun_flags |= TUN_OPEN; 189 TUNDEBUG(ifp, "open\n"); 190 return (0); 191 } 192 193 /* 194 * tunclose - close the device - mark i/f down & delete 195 * routing info 196 */ 197 static int 198 tunclose(struct dev_close_args *ap) 199 { 200 cdev_t dev = ap->a_head.a_dev; 201 struct tun_softc *tp; 202 struct ifnet *ifp; 203 204 tp = dev->si_drv1; 205 ifp = &tp->tun_if; 206 207 tp->tun_flags &= ~TUN_OPEN; 208 tp->tun_pid = 0; 209 210 /* Junk all pending output. */ 211 ifq_purge_all(&ifp->if_snd); 212 213 if (ifp->if_flags & IFF_UP) 214 if_down(ifp); 215 ifp->if_flags &= ~IFF_RUNNING; 216 if_purgeaddrs_nolink(ifp); 217 218 funsetown(&tp->tun_sigio); 219 KNOTE(&tp->tun_rkq.ki_note, 0); 220 221 TUNDEBUG(ifp, "closed\n"); 222 #if 0 223 if (dev->si_uminor >= TUN_PREALLOCATED_UNITS) { 224 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(tun), dev->si_uminor); 225 } 226 #endif 227 return (0); 228 } 229 230 static int 231 tuninit(struct ifnet *ifp) 232 { 233 #ifdef INET 234 struct tun_softc *tp = ifp->if_softc; 235 #endif 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 bpf_gettoken(); 344 if (ifp->if_bpf) { 345 /* 346 * We need to prepend the address family as 347 * a four byte field. 348 */ 349 uint32_t af = dst->sa_family; 350 351 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af)); 352 } 353 bpf_reltoken(); 354 } 355 356 /* prepend sockaddr? this may abort if the mbuf allocation fails */ 357 if (tp->tun_flags & TUN_LMODE) { 358 /* allocate space for sockaddr */ 359 M_PREPEND(m0, dst->sa_len, MB_DONTWAIT); 360 361 /* if allocation failed drop packet */ 362 if (m0 == NULL){ 363 IFNET_STAT_INC(ifp, oerrors, 1); 364 return (ENOBUFS); 365 } else { 366 bcopy(dst, m0->m_data, dst->sa_len); 367 } 368 } 369 370 if (tp->tun_flags & TUN_IFHEAD) { 371 /* Prepend the address family */ 372 M_PREPEND(m0, 4, MB_DONTWAIT); 373 374 /* if allocation failed drop packet */ 375 if (m0 == NULL){ 376 IFNET_STAT_INC(ifp, oerrors, 1); 377 return ENOBUFS; 378 } else 379 *(u_int32_t *)m0->m_data = htonl(dst->sa_family); 380 } else { 381 #ifdef INET 382 if (dst->sa_family != AF_INET) 383 #endif 384 { 385 m_freem(m0); 386 return EAFNOSUPPORT; 387 } 388 } 389 390 error = ifq_handoff(ifp, m0, &pktattr); 391 if (error) { 392 IFNET_STAT_INC(ifp, collisions, 1); 393 } else { 394 IFNET_STAT_INC(ifp, opackets, 1); 395 if (tp->tun_flags & TUN_RWAIT) { 396 tp->tun_flags &= ~TUN_RWAIT; 397 wakeup((caddr_t)tp); 398 } 399 get_mplock(); 400 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) 401 pgsigio(tp->tun_sigio, SIGIO, 0); 402 rel_mplock(); 403 ifnet_deserialize_all(ifp); 404 KNOTE(&tp->tun_rkq.ki_note, 0); 405 ifnet_serialize_all(ifp); 406 } 407 return (error); 408 } 409 410 static int 411 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 412 struct rtentry *rt) 413 { 414 int error; 415 416 ifnet_serialize_all(ifp); 417 error = tunoutput_serialized(ifp, m0, dst, rt); 418 ifnet_deserialize_all(ifp); 419 420 return error; 421 } 422 423 /* 424 * the ops interface is now pretty minimal. 425 */ 426 static int 427 tunioctl(struct dev_ioctl_args *ap) 428 { 429 cdev_t dev = ap->a_head.a_dev; 430 struct tun_softc *tp = dev->si_drv1; 431 struct tuninfo *tunp; 432 433 switch (ap->a_cmd) { 434 case TUNSIFINFO: 435 tunp = (struct tuninfo *)ap->a_data; 436 if (tunp->mtu < IF_MINMTU) 437 return (EINVAL); 438 tp->tun_if.if_mtu = tunp->mtu; 439 tp->tun_if.if_type = tunp->type; 440 tp->tun_if.if_baudrate = tunp->baudrate; 441 break; 442 case TUNGIFINFO: 443 tunp = (struct tuninfo *)ap->a_data; 444 tunp->mtu = tp->tun_if.if_mtu; 445 tunp->type = tp->tun_if.if_type; 446 tunp->baudrate = tp->tun_if.if_baudrate; 447 break; 448 case TUNSDEBUG: 449 tundebug = *(int *)ap->a_data; 450 break; 451 case TUNGDEBUG: 452 *(int *)ap->a_data = tundebug; 453 break; 454 case TUNSLMODE: 455 if (*(int *)ap->a_data) { 456 tp->tun_flags |= TUN_LMODE; 457 tp->tun_flags &= ~TUN_IFHEAD; 458 } else 459 tp->tun_flags &= ~TUN_LMODE; 460 break; 461 case TUNSIFHEAD: 462 if (*(int *)ap->a_data) { 463 tp->tun_flags |= TUN_IFHEAD; 464 tp->tun_flags &= ~TUN_LMODE; 465 } else 466 tp->tun_flags &= ~TUN_IFHEAD; 467 break; 468 case TUNGIFHEAD: 469 *(int *)ap->a_data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 470 break; 471 case TUNSIFMODE: 472 /* deny this if UP */ 473 if (tp->tun_if.if_flags & IFF_UP) 474 return(EBUSY); 475 476 switch (*(int *)ap->a_data & ~IFF_MULTICAST) { 477 case IFF_POINTOPOINT: 478 case IFF_BROADCAST: 479 tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT); 480 tp->tun_if.if_flags |= *(int *)ap->a_data; 481 break; 482 default: 483 return(EINVAL); 484 } 485 break; 486 case TUNSIFPID: 487 tp->tun_pid = curproc->p_pid; 488 break; 489 case FIOASYNC: 490 if (*(int *)ap->a_data) 491 tp->tun_flags |= TUN_ASYNC; 492 else 493 tp->tun_flags &= ~TUN_ASYNC; 494 break; 495 case FIONREAD: 496 if (!ifsq_is_empty(ifq_get_subq_default(&tp->tun_if.if_snd))) { 497 struct mbuf *mb; 498 499 mb = ifsq_poll( 500 ifq_get_subq_default(&tp->tun_if.if_snd)); 501 for( *(int *)ap->a_data = 0; mb != NULL; mb = mb->m_next) 502 *(int *)ap->a_data += mb->m_len; 503 } else { 504 *(int *)ap->a_data = 0; 505 } 506 break; 507 case FIOSETOWN: 508 return (fsetown(*(int *)ap->a_data, &tp->tun_sigio)); 509 510 case FIOGETOWN: 511 *(int *)ap->a_data = fgetown(&tp->tun_sigio); 512 return (0); 513 514 /* This is deprecated, FIOSETOWN should be used instead. */ 515 case TIOCSPGRP: 516 return (fsetown(-(*(int *)ap->a_data), &tp->tun_sigio)); 517 518 /* This is deprecated, FIOGETOWN should be used instead. */ 519 case TIOCGPGRP: 520 *(int *)ap->a_data = -fgetown(&tp->tun_sigio); 521 return (0); 522 523 default: 524 return (ENOTTY); 525 } 526 return (0); 527 } 528 529 /* 530 * The ops read interface - reads a packet at a time, or at 531 * least as much of a packet as can be read. 532 */ 533 static int 534 tunread(struct dev_read_args *ap) 535 { 536 cdev_t dev = ap->a_head.a_dev; 537 struct uio *uio = ap->a_uio; 538 struct tun_softc *tp = dev->si_drv1; 539 struct ifnet *ifp = &tp->tun_if; 540 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd); 541 struct mbuf *m0; 542 int error=0, len; 543 544 TUNDEBUG(ifp, "read\n"); 545 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 546 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags); 547 return EHOSTDOWN; 548 } 549 550 tp->tun_flags &= ~TUN_RWAIT; 551 552 ifnet_serialize_all(ifp); 553 554 while ((m0 = ifsq_dequeue(ifsq, NULL)) == NULL) { 555 if (ap->a_ioflag & IO_NDELAY) { 556 ifnet_deserialize_all(ifp); 557 return EWOULDBLOCK; 558 } 559 tp->tun_flags |= TUN_RWAIT; 560 ifnet_deserialize_all(ifp); 561 if ((error = tsleep(tp, PCATCH, "tunread", 0)) != 0) 562 return error; 563 ifnet_serialize_all(ifp); 564 } 565 566 ifnet_deserialize_all(ifp); 567 568 while (m0 && uio->uio_resid > 0 && error == 0) { 569 len = (int)szmin(uio->uio_resid, m0->m_len); 570 if (len != 0) 571 error = uiomove(mtod(m0, caddr_t), (size_t)len, uio); 572 m0 = m_free(m0); 573 } 574 575 if (m0) { 576 TUNDEBUG(ifp, "Dropping mbuf\n"); 577 m_freem(m0); 578 } 579 return error; 580 } 581 582 /* 583 * the ops write interface - an atomic write is a packet - or else! 584 */ 585 static int 586 tunwrite(struct dev_write_args *ap) 587 { 588 cdev_t dev = ap->a_head.a_dev; 589 struct uio *uio = ap->a_uio; 590 struct tun_softc *tp = dev->si_drv1; 591 struct ifnet *ifp = &tp->tun_if; 592 struct mbuf *top, **mp, *m; 593 int error=0; 594 size_t tlen, mlen; 595 uint32_t family; 596 int isr; 597 598 TUNDEBUG(ifp, "tunwrite\n"); 599 600 if (uio->uio_resid == 0) 601 return 0; 602 603 if (uio->uio_resid > TUNMRU) { 604 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid); 605 return EIO; 606 } 607 tlen = uio->uio_resid; 608 609 /* get a header mbuf */ 610 MGETHDR(m, MB_WAIT, MT_DATA); 611 if (m == NULL) 612 return ENOBUFS; 613 mlen = MHLEN; 614 615 top = NULL; 616 mp = ⊤ 617 while (error == 0 && uio->uio_resid > 0) { 618 m->m_len = (int)szmin(mlen, uio->uio_resid); 619 error = uiomove(mtod (m, caddr_t), (size_t)m->m_len, uio); 620 *mp = m; 621 mp = &m->m_next; 622 if (uio->uio_resid > 0) { 623 MGET (m, MB_WAIT, MT_DATA); 624 if (m == NULL) { 625 error = ENOBUFS; 626 break; 627 } 628 mlen = MLEN; 629 } 630 } 631 if (error) { 632 if (top) 633 m_freem (top); 634 IFNET_STAT_INC(ifp, ierrors, 1); 635 return error; 636 } 637 638 top->m_pkthdr.len = (int)tlen; 639 top->m_pkthdr.rcvif = ifp; 640 641 if (ifp->if_bpf) { 642 bpf_gettoken(); 643 644 if (ifp->if_bpf) { 645 if (tp->tun_flags & TUN_IFHEAD) { 646 /* 647 * Conveniently, we already have a 4-byte 648 * address family prepended to our packet ! 649 * Inconveniently, it's in the wrong byte 650 * order ! 651 */ 652 if ((top = m_pullup(top, sizeof(family))) 653 == NULL) { 654 bpf_reltoken(); 655 return ENOBUFS; 656 } 657 *mtod(top, u_int32_t *) = 658 ntohl(*mtod(top, u_int32_t *)); 659 bpf_mtap(ifp->if_bpf, top); 660 *mtod(top, u_int32_t *) = 661 htonl(*mtod(top, u_int32_t *)); 662 } else { 663 /* 664 * We need to prepend the address family as 665 * a four byte field. 666 */ 667 static const uint32_t af = AF_INET; 668 669 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af)); 670 } 671 } 672 673 bpf_reltoken(); 674 } 675 676 if (tp->tun_flags & TUN_IFHEAD) { 677 if (top->m_len < sizeof(family) && 678 (top = m_pullup(top, sizeof(family))) == NULL) 679 return ENOBUFS; 680 family = ntohl(*mtod(top, u_int32_t *)); 681 m_adj(top, sizeof(family)); 682 } else 683 family = AF_INET; 684 685 IFNET_STAT_INC(ifp, ibytes, top->m_pkthdr.len); 686 IFNET_STAT_INC(ifp, ipackets, 1); 687 688 switch (family) { 689 #ifdef INET 690 case AF_INET: 691 isr = NETISR_IP; 692 break; 693 #endif 694 #ifdef INET6 695 case AF_INET6: 696 isr = NETISR_IPV6; 697 break; 698 #endif 699 #ifdef IPX 700 case AF_IPX: 701 isr = NETISR_IPX; 702 break; 703 #endif 704 default: 705 m_freem(m); 706 return (EAFNOSUPPORT); 707 } 708 709 netisr_queue(isr, top); 710 return (0); 711 } 712 713 static struct filterops tun_read_filtops = 714 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_read }; 715 static struct filterops tun_write_filtops = 716 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_write }; 717 718 static int 719 tunkqfilter(struct dev_kqfilter_args *ap) 720 { 721 cdev_t dev = ap->a_head.a_dev; 722 struct tun_softc *tp = dev->si_drv1; 723 struct knote *kn = ap->a_kn; 724 struct klist *klist; 725 726 ap->a_result = 0; 727 ifnet_serialize_all(&tp->tun_if); 728 729 switch (kn->kn_filter) { 730 case EVFILT_READ: 731 kn->kn_fop = &tun_read_filtops; 732 kn->kn_hook = (caddr_t)tp; 733 break; 734 case EVFILT_WRITE: 735 kn->kn_fop = &tun_write_filtops; 736 kn->kn_hook = (caddr_t)tp; 737 break; 738 default: 739 ifnet_deserialize_all(&tp->tun_if); 740 ap->a_result = EOPNOTSUPP; 741 return (0); 742 } 743 744 klist = &tp->tun_rkq.ki_note; 745 knote_insert(klist, kn); 746 ifnet_deserialize_all(&tp->tun_if); 747 748 return (0); 749 } 750 751 static void 752 tun_filter_detach(struct knote *kn) 753 { 754 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook; 755 struct klist *klist = &tp->tun_rkq.ki_note; 756 757 knote_remove(klist, kn); 758 } 759 760 static int 761 tun_filter_write(struct knote *kn, long hint) 762 { 763 /* Always ready for a write */ 764 return (1); 765 } 766 767 static int 768 tun_filter_read(struct knote *kn, long hint) 769 { 770 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook; 771 int ready = 0; 772 773 ifnet_serialize_all(&tp->tun_if); 774 if (!ifsq_is_empty(ifq_get_subq_default(&tp->tun_if.if_snd))) 775 ready = 1; 776 ifnet_deserialize_all(&tp->tun_if); 777 778 return (ready); 779 } 780 781 /* 782 * Start packet transmission on the interface. 783 * when the interface queue is rate-limited by ALTQ, 784 * if_start is needed to drain packets from the queue in order 785 * to notify readers when outgoing packets become ready. 786 */ 787 static void 788 tunstart(struct ifnet *ifp, struct ifaltq_subque *ifsq) 789 { 790 struct tun_softc *tp = ifp->if_softc; 791 struct mbuf *m; 792 793 ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq); 794 795 if (!ifq_is_enabled(&ifp->if_snd)) 796 return; 797 798 m = ifsq_poll(ifsq); 799 if (m != NULL) { 800 if (tp->tun_flags & TUN_RWAIT) { 801 tp->tun_flags &= ~TUN_RWAIT; 802 wakeup((caddr_t)tp); 803 } 804 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) 805 pgsigio(tp->tun_sigio, SIGIO, 0); 806 ifsq_deserialize_hw(ifsq); 807 KNOTE(&tp->tun_rkq.ki_note, 0); 808 ifsq_serialize_hw(ifsq); 809 } 810 } 811