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_atalk.h" 21 #include "opt_inet.h" 22 #include "opt_inet6.h" 23 #include "opt_ipx.h" 24 25 #include <sys/param.h> 26 #include <sys/proc.h> 27 #include <sys/priv.h> 28 #include <sys/systm.h> 29 #include <sys/mbuf.h> 30 #include <sys/socket.h> 31 #include <sys/conf.h> 32 #include <sys/device.h> 33 #include <sys/filio.h> 34 #include <sys/sockio.h> 35 #include <sys/thread2.h> 36 #include <sys/ttycom.h> 37 #include <sys/signalvar.h> 38 #include <sys/filedesc.h> 39 #include <sys/kernel.h> 40 #include <sys/sysctl.h> 41 #include <sys/uio.h> 42 #include <sys/vnode.h> 43 #include <sys/malloc.h> 44 45 #include <sys/mplock2.h> 46 47 #include <net/if.h> 48 #include <net/if_types.h> 49 #include <net/ifq_var.h> 50 #include <net/netisr.h> 51 #include <net/route.h> 52 #include <sys/devfs.h> 53 54 #ifdef INET 55 #include <netinet/in.h> 56 #endif 57 58 #include <net/bpf.h> 59 60 #include "if_tunvar.h" 61 #include "if_tun.h" 62 63 static MALLOC_DEFINE(M_TUN, "tun", "Tunnel Interface"); 64 65 static void tunattach (void *); 66 PSEUDO_SET(tunattach, if_tun); 67 68 static void tuncreate (cdev_t dev); 69 70 #define TUNDEBUG if (tundebug) if_printf 71 static int tundebug = 0; 72 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, ""); 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 *); 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 MALLOC(sc, struct tun_softc *, 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(&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 struct tun_softc *tp = ifp->if_softc; 234 struct ifaddr_container *ifac; 235 int error = 0; 236 237 TUNDEBUG(ifp, "tuninit\n"); 238 239 ifp->if_flags |= IFF_UP | IFF_RUNNING; 240 getmicrotime(&ifp->if_lastchange); 241 242 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 243 struct ifaddr *ifa = ifac->ifa; 244 245 if (ifa->ifa_addr == NULL) { 246 error = EFAULT; 247 /* XXX: Should maybe return straight off? */ 248 } else { 249 #ifdef INET 250 if (ifa->ifa_addr->sa_family == AF_INET) { 251 struct sockaddr_in *si; 252 253 si = (struct sockaddr_in *)ifa->ifa_addr; 254 if (si->sin_addr.s_addr) 255 tp->tun_flags |= TUN_IASET; 256 } 257 #endif 258 } 259 } 260 return (error); 261 } 262 263 /* 264 * Process an ioctl request. 265 * 266 * MPSAFE 267 */ 268 int 269 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 270 { 271 struct ifreq *ifr = (struct ifreq *)data; 272 struct tun_softc *tp = ifp->if_softc; 273 struct ifstat *ifs; 274 int error = 0; 275 276 switch(cmd) { 277 case SIOCGIFSTATUS: 278 ifs = (struct ifstat *)data; 279 if (tp->tun_pid) 280 ksprintf(ifs->ascii + strlen(ifs->ascii), 281 "\tOpened by PID %d\n", tp->tun_pid); 282 break; 283 case SIOCSIFADDR: 284 error = tuninit(ifp); 285 TUNDEBUG(ifp, "address set, error=%d\n", error); 286 break; 287 case SIOCSIFDSTADDR: 288 error = tuninit(ifp); 289 TUNDEBUG(ifp, "destination address set, error=%d\n", error); 290 break; 291 case SIOCSIFMTU: 292 ifp->if_mtu = ifr->ifr_mtu; 293 TUNDEBUG(ifp, "mtu set\n"); 294 break; 295 case SIOCSIFFLAGS: 296 case SIOCADDMULTI: 297 case SIOCDELMULTI: 298 break; 299 default: 300 error = EINVAL; 301 } 302 return (error); 303 } 304 305 /* 306 * tunoutput - queue packets from higher level ready to put out. 307 * 308 * MPSAFE 309 */ 310 static int 311 tunoutput_serialized(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 312 struct rtentry *rt) 313 { 314 struct tun_softc *tp = ifp->if_softc; 315 int error; 316 struct altq_pktattr pktattr; 317 318 TUNDEBUG(ifp, "tunoutput\n"); 319 320 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 321 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags); 322 m_freem (m0); 323 return EHOSTDOWN; 324 } 325 326 /* 327 * if the queueing discipline needs packet classification, 328 * do it before prepending link headers. 329 */ 330 ifq_classify(&ifp->if_snd, m0, dst->sa_family, &pktattr); 331 332 /* BPF write needs to be handled specially */ 333 if (dst->sa_family == AF_UNSPEC) { 334 dst->sa_family = *(mtod(m0, int *)); 335 m0->m_len -= sizeof(int); 336 m0->m_pkthdr.len -= sizeof(int); 337 m0->m_data += sizeof(int); 338 } 339 340 if (ifp->if_bpf) { 341 /* 342 * We need to prepend the address family as 343 * a four byte field. 344 */ 345 uint32_t af = dst->sa_family; 346 347 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af)); 348 } 349 350 /* prepend sockaddr? this may abort if the mbuf allocation fails */ 351 if (tp->tun_flags & TUN_LMODE) { 352 /* allocate space for sockaddr */ 353 M_PREPEND(m0, dst->sa_len, MB_DONTWAIT); 354 355 /* if allocation failed drop packet */ 356 if (m0 == NULL){ 357 IF_DROP(&ifp->if_snd); 358 ifp->if_oerrors++; 359 return (ENOBUFS); 360 } else { 361 bcopy(dst, m0->m_data, dst->sa_len); 362 } 363 } 364 365 if (tp->tun_flags & TUN_IFHEAD) { 366 /* Prepend the address family */ 367 M_PREPEND(m0, 4, MB_DONTWAIT); 368 369 /* if allocation failed drop packet */ 370 if (m0 == NULL){ 371 IF_DROP(&ifp->if_snd); 372 ifp->if_oerrors++; 373 return ENOBUFS; 374 } else 375 *(u_int32_t *)m0->m_data = htonl(dst->sa_family); 376 } else { 377 #ifdef INET 378 if (dst->sa_family != AF_INET) 379 #endif 380 { 381 m_freem(m0); 382 return EAFNOSUPPORT; 383 } 384 } 385 386 error = ifq_handoff(ifp, m0, &pktattr); 387 if (error) { 388 ifp->if_collisions++; 389 } else { 390 ifp->if_opackets++; 391 if (tp->tun_flags & TUN_RWAIT) { 392 tp->tun_flags &= ~TUN_RWAIT; 393 wakeup((caddr_t)tp); 394 } 395 get_mplock(); 396 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) 397 pgsigio(tp->tun_sigio, SIGIO, 0); 398 rel_mplock(); 399 ifnet_deserialize_all(ifp); 400 KNOTE(&tp->tun_rkq.ki_note, 0); 401 ifnet_serialize_all(ifp); 402 } 403 return (error); 404 } 405 406 static int 407 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 408 struct rtentry *rt) 409 { 410 int error; 411 412 ifnet_serialize_all(ifp); 413 error = tunoutput_serialized(ifp, m0, dst, rt); 414 ifnet_deserialize_all(ifp); 415 416 return error; 417 } 418 419 /* 420 * the ops interface is now pretty minimal. 421 */ 422 static int 423 tunioctl(struct dev_ioctl_args *ap) 424 { 425 cdev_t dev = ap->a_head.a_dev; 426 struct tun_softc *tp = dev->si_drv1; 427 struct tuninfo *tunp; 428 429 switch (ap->a_cmd) { 430 case TUNSIFINFO: 431 tunp = (struct tuninfo *)ap->a_data; 432 if (tunp->mtu < IF_MINMTU) 433 return (EINVAL); 434 tp->tun_if.if_mtu = tunp->mtu; 435 tp->tun_if.if_type = tunp->type; 436 tp->tun_if.if_baudrate = tunp->baudrate; 437 break; 438 case TUNGIFINFO: 439 tunp = (struct tuninfo *)ap->a_data; 440 tunp->mtu = tp->tun_if.if_mtu; 441 tunp->type = tp->tun_if.if_type; 442 tunp->baudrate = tp->tun_if.if_baudrate; 443 break; 444 case TUNSDEBUG: 445 tundebug = *(int *)ap->a_data; 446 break; 447 case TUNGDEBUG: 448 *(int *)ap->a_data = tundebug; 449 break; 450 case TUNSLMODE: 451 if (*(int *)ap->a_data) { 452 tp->tun_flags |= TUN_LMODE; 453 tp->tun_flags &= ~TUN_IFHEAD; 454 } else 455 tp->tun_flags &= ~TUN_LMODE; 456 break; 457 case TUNSIFHEAD: 458 if (*(int *)ap->a_data) { 459 tp->tun_flags |= TUN_IFHEAD; 460 tp->tun_flags &= ~TUN_LMODE; 461 } else 462 tp->tun_flags &= ~TUN_IFHEAD; 463 break; 464 case TUNGIFHEAD: 465 *(int *)ap->a_data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0; 466 break; 467 case TUNSIFMODE: 468 /* deny this if UP */ 469 if (tp->tun_if.if_flags & IFF_UP) 470 return(EBUSY); 471 472 switch (*(int *)ap->a_data & ~IFF_MULTICAST) { 473 case IFF_POINTOPOINT: 474 case IFF_BROADCAST: 475 tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT); 476 tp->tun_if.if_flags |= *(int *)ap->a_data; 477 break; 478 default: 479 return(EINVAL); 480 } 481 break; 482 case TUNSIFPID: 483 tp->tun_pid = curproc->p_pid; 484 break; 485 case FIOASYNC: 486 if (*(int *)ap->a_data) 487 tp->tun_flags |= TUN_ASYNC; 488 else 489 tp->tun_flags &= ~TUN_ASYNC; 490 break; 491 case FIONREAD: 492 if (!ifq_is_empty(&tp->tun_if.if_snd)) { 493 struct mbuf *mb; 494 495 mb = ifq_poll(&tp->tun_if.if_snd); 496 for( *(int *)ap->a_data = 0; mb != 0; mb = mb->m_next) 497 *(int *)ap->a_data += mb->m_len; 498 } else { 499 *(int *)ap->a_data = 0; 500 } 501 break; 502 case FIOSETOWN: 503 return (fsetown(*(int *)ap->a_data, &tp->tun_sigio)); 504 505 case FIOGETOWN: 506 *(int *)ap->a_data = fgetown(tp->tun_sigio); 507 return (0); 508 509 /* This is deprecated, FIOSETOWN should be used instead. */ 510 case TIOCSPGRP: 511 return (fsetown(-(*(int *)ap->a_data), &tp->tun_sigio)); 512 513 /* This is deprecated, FIOGETOWN should be used instead. */ 514 case TIOCGPGRP: 515 *(int *)ap->a_data = -fgetown(tp->tun_sigio); 516 return (0); 517 518 default: 519 return (ENOTTY); 520 } 521 return (0); 522 } 523 524 /* 525 * The ops read interface - reads a packet at a time, or at 526 * least as much of a packet as can be read. 527 */ 528 static int 529 tunread(struct dev_read_args *ap) 530 { 531 cdev_t dev = ap->a_head.a_dev; 532 struct uio *uio = ap->a_uio; 533 struct tun_softc *tp = dev->si_drv1; 534 struct ifnet *ifp = &tp->tun_if; 535 struct mbuf *m0; 536 int error=0, len; 537 538 TUNDEBUG(ifp, "read\n"); 539 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 540 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags); 541 return EHOSTDOWN; 542 } 543 544 tp->tun_flags &= ~TUN_RWAIT; 545 546 ifnet_serialize_all(ifp); 547 548 while ((m0 = ifq_dequeue(&ifp->if_snd, NULL)) == NULL) { 549 if (ap->a_ioflag & IO_NDELAY) { 550 ifnet_deserialize_all(ifp); 551 return EWOULDBLOCK; 552 } 553 tp->tun_flags |= TUN_RWAIT; 554 ifnet_deserialize_all(ifp); 555 if ((error = tsleep(tp, PCATCH, "tunread", 0)) != 0) 556 return error; 557 ifnet_serialize_all(ifp); 558 } 559 560 ifnet_deserialize_all(ifp); 561 562 while (m0 && uio->uio_resid > 0 && error == 0) { 563 len = (int)szmin(uio->uio_resid, m0->m_len); 564 if (len != 0) 565 error = uiomove(mtod(m0, caddr_t), (size_t)len, uio); 566 m0 = m_free(m0); 567 } 568 569 if (m0) { 570 TUNDEBUG(ifp, "Dropping mbuf\n"); 571 m_freem(m0); 572 } 573 return error; 574 } 575 576 /* 577 * the ops write interface - an atomic write is a packet - or else! 578 */ 579 static int 580 tunwrite(struct dev_write_args *ap) 581 { 582 cdev_t dev = ap->a_head.a_dev; 583 struct uio *uio = ap->a_uio; 584 struct tun_softc *tp = dev->si_drv1; 585 struct ifnet *ifp = &tp->tun_if; 586 struct mbuf *top, **mp, *m; 587 int error=0; 588 size_t tlen, mlen; 589 uint32_t family; 590 int isr; 591 592 TUNDEBUG(ifp, "tunwrite\n"); 593 594 if (uio->uio_resid == 0) 595 return 0; 596 597 if (uio->uio_resid > TUNMRU) { 598 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid); 599 return EIO; 600 } 601 tlen = uio->uio_resid; 602 603 /* get a header mbuf */ 604 MGETHDR(m, MB_DONTWAIT, MT_DATA); 605 if (m == NULL) 606 return ENOBUFS; 607 mlen = MHLEN; 608 609 top = 0; 610 mp = ⊤ 611 while (error == 0 && uio->uio_resid > 0) { 612 m->m_len = (int)szmin(mlen, uio->uio_resid); 613 error = uiomove(mtod (m, caddr_t), (size_t)m->m_len, uio); 614 *mp = m; 615 mp = &m->m_next; 616 if (uio->uio_resid > 0) { 617 MGET (m, MB_DONTWAIT, MT_DATA); 618 if (m == 0) { 619 error = ENOBUFS; 620 break; 621 } 622 mlen = MLEN; 623 } 624 } 625 if (error) { 626 if (top) 627 m_freem (top); 628 ifp->if_ierrors++; 629 return error; 630 } 631 632 top->m_pkthdr.len = (int)tlen; 633 top->m_pkthdr.rcvif = ifp; 634 635 if (ifp->if_bpf) { 636 if (tp->tun_flags & TUN_IFHEAD) { 637 /* 638 * Conveniently, we already have a 4-byte address 639 * family prepended to our packet ! 640 * Inconveniently, it's in the wrong byte order ! 641 */ 642 if ((top = m_pullup(top, sizeof(family))) == NULL) 643 return ENOBUFS; 644 *mtod(top, u_int32_t *) = 645 ntohl(*mtod(top, u_int32_t *)); 646 bpf_mtap(ifp->if_bpf, top); 647 *mtod(top, u_int32_t *) = 648 htonl(*mtod(top, u_int32_t *)); 649 } else { 650 /* 651 * We need to prepend the address family as 652 * a four byte field. 653 */ 654 static const uint32_t af = AF_INET; 655 656 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af)); 657 } 658 } 659 660 if (tp->tun_flags & TUN_IFHEAD) { 661 if (top->m_len < sizeof(family) && 662 (top = m_pullup(top, sizeof(family))) == NULL) 663 return ENOBUFS; 664 family = ntohl(*mtod(top, u_int32_t *)); 665 m_adj(top, sizeof(family)); 666 } else 667 family = AF_INET; 668 669 ifp->if_ibytes += top->m_pkthdr.len; 670 ifp->if_ipackets++; 671 672 switch (family) { 673 #ifdef INET 674 case AF_INET: 675 isr = NETISR_IP; 676 break; 677 #endif 678 #ifdef INET6 679 case AF_INET6: 680 isr = NETISR_IPV6; 681 break; 682 #endif 683 #ifdef IPX 684 case AF_IPX: 685 isr = NETISR_IPX; 686 break; 687 #endif 688 #ifdef NETATALK 689 case AF_APPLETALK: 690 isr = NETISR_ATALK2; 691 break; 692 #endif 693 default: 694 m_freem(m); 695 return (EAFNOSUPPORT); 696 } 697 698 netisr_queue(isr, top); 699 return (0); 700 } 701 702 static struct filterops tun_read_filtops = 703 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_read }; 704 static struct filterops tun_write_filtops = 705 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_write }; 706 707 static int 708 tunkqfilter(struct dev_kqfilter_args *ap) 709 { 710 cdev_t dev = ap->a_head.a_dev; 711 struct tun_softc *tp = dev->si_drv1; 712 struct knote *kn = ap->a_kn; 713 struct klist *klist; 714 715 ap->a_result = 0; 716 ifnet_serialize_all(&tp->tun_if); 717 718 switch (kn->kn_filter) { 719 case EVFILT_READ: 720 kn->kn_fop = &tun_read_filtops; 721 kn->kn_hook = (caddr_t)tp; 722 break; 723 case EVFILT_WRITE: 724 kn->kn_fop = &tun_write_filtops; 725 kn->kn_hook = (caddr_t)tp; 726 break; 727 default: 728 ifnet_deserialize_all(&tp->tun_if); 729 ap->a_result = EOPNOTSUPP; 730 return (0); 731 } 732 733 klist = &tp->tun_rkq.ki_note; 734 knote_insert(klist, kn); 735 ifnet_deserialize_all(&tp->tun_if); 736 737 return (0); 738 } 739 740 static void 741 tun_filter_detach(struct knote *kn) 742 { 743 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook; 744 struct klist *klist = &tp->tun_rkq.ki_note; 745 746 knote_remove(klist, kn); 747 } 748 749 static int 750 tun_filter_write(struct knote *kn, long hint) 751 { 752 /* Always ready for a write */ 753 return (1); 754 } 755 756 static int 757 tun_filter_read(struct knote *kn, long hint) 758 { 759 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook; 760 int ready = 0; 761 762 ifnet_serialize_all(&tp->tun_if); 763 if (!ifq_is_empty(&tp->tun_if.if_snd)) 764 ready = 1; 765 ifnet_deserialize_all(&tp->tun_if); 766 767 return (ready); 768 } 769 770 /* 771 * Start packet transmission on the interface. 772 * when the interface queue is rate-limited by ALTQ, 773 * if_start is needed to drain packets from the queue in order 774 * to notify readers when outgoing packets become ready. 775 */ 776 static void 777 tunstart(struct ifnet *ifp) 778 { 779 struct tun_softc *tp = ifp->if_softc; 780 struct mbuf *m; 781 782 if (!ifq_is_enabled(&ifp->if_snd)) 783 return; 784 785 m = ifq_poll(&ifp->if_snd); 786 if (m != NULL) { 787 if (tp->tun_flags & TUN_RWAIT) { 788 tp->tun_flags &= ~TUN_RWAIT; 789 wakeup((caddr_t)tp); 790 } 791 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) 792 pgsigio(tp->tun_sigio, SIGIO, 0); 793 ifnet_deserialize_tx(ifp); 794 KNOTE(&tp->tun_rkq.ki_note, 0); 795 ifnet_serialize_tx(ifp); 796 } 797 } 798