if_tun.c revision 1.68
1 /* $NetBSD: if_tun.c,v 1.68 2004/03/01 13:54:02 tron Exp $ */ 2 3 /* 4 * Copyright (c) 1988, Julian Onions <jpo (at) 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 its 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 17 #include <sys/cdefs.h> 18 __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.68 2004/03/01 13:54:02 tron Exp $"); 19 20 #include "tun.h" 21 22 #include "opt_inet.h" 23 #include "opt_ns.h" 24 25 #include <sys/param.h> 26 #include <sys/proc.h> 27 #include <sys/systm.h> 28 #include <sys/mbuf.h> 29 #include <sys/buf.h> 30 #include <sys/protosw.h> 31 #include <sys/socket.h> 32 #include <sys/ioctl.h> 33 #include <sys/errno.h> 34 #include <sys/syslog.h> 35 #include <sys/select.h> 36 #include <sys/poll.h> 37 #include <sys/file.h> 38 #include <sys/signalvar.h> 39 #include <sys/conf.h> 40 41 #include <machine/cpu.h> 42 43 #include <net/if.h> 44 #include <net/if_ether.h> 45 #include <net/netisr.h> 46 #include <net/route.h> 47 48 49 #ifdef INET 50 #include <netinet/in.h> 51 #include <netinet/in_systm.h> 52 #include <netinet/in_var.h> 53 #include <netinet/ip.h> 54 #include <netinet/if_inarp.h> 55 #endif 56 57 #ifdef NS 58 #include <netns/ns.h> 59 #include <netns/ns_if.h> 60 #endif 61 62 #include "bpfilter.h" 63 #if NBPFILTER > 0 64 #include <sys/time.h> 65 #include <net/bpf.h> 66 #endif 67 68 #include <net/if_tun.h> 69 70 #define TUNDEBUG if (tundebug) printf 71 int tundebug = 0; 72 73 extern int ifqmaxlen; 74 void tunattach __P((int)); 75 LIST_HEAD(, tun_softc) tun_softc_list; 76 static struct simplelock tun_softc_lock; 77 78 int tun_ioctl __P((struct ifnet *, u_long, caddr_t)); 79 int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 80 struct rtentry *rt)); 81 int tun_clone_create __P((struct if_clone *, int)); 82 void tun_clone_destroy __P((struct ifnet *)); 83 84 struct if_clone tun_cloner = 85 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 86 87 static void tunattach0 __P((struct tun_softc *)); 88 static void tuninit __P((struct tun_softc *)); 89 #ifdef ALTQ 90 static void tunstart __P((struct ifnet *)); 91 #endif 92 static struct tun_softc *tun_find_unit __P((dev_t)); 93 94 dev_type_open(tunopen); 95 dev_type_close(tunclose); 96 dev_type_read(tunread); 97 dev_type_write(tunwrite); 98 dev_type_ioctl(tunioctl); 99 dev_type_poll(tunpoll); 100 dev_type_kqfilter(tunkqfilter); 101 102 const struct cdevsw tun_cdevsw = { 103 tunopen, tunclose, tunread, tunwrite, tunioctl, 104 nostop, notty, tunpoll, nommap, tunkqfilter, 105 }; 106 107 void 108 tunattach(unused) 109 int unused; 110 { 111 112 simple_lock_init(&tun_softc_lock); 113 LIST_INIT(&tun_softc_list); 114 if_clone_attach(&tun_cloner); 115 } 116 117 int 118 tun_clone_create(ifc, unit) 119 struct if_clone *ifc; 120 int unit; 121 { 122 struct tun_softc *sc; 123 124 sc = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 125 (void)memset(sc, 0, sizeof(struct tun_softc)); 126 127 (void)snprintf(sc->tun_if.if_xname, sizeof(sc->tun_if.if_xname), 128 "%s%d", ifc->ifc_name, unit); 129 sc->tun_unit = unit; 130 simple_lock_init(&sc->tun_lock); 131 132 tunattach0(sc); 133 134 simple_lock(&tun_softc_lock); 135 LIST_INSERT_HEAD(&tun_softc_list, sc, tun_list); 136 simple_unlock(&tun_softc_lock); 137 138 return (0); 139 } 140 141 void 142 tunattach0(sc) 143 struct tun_softc *sc; 144 { 145 struct ifnet *ifp = (void *)sc; 146 147 sc->tun_flags = TUN_INITED; 148 149 ifp = &sc->tun_if; 150 ifp->if_softc = sc; 151 ifp->if_mtu = TUNMTU; 152 ifp->if_ioctl = tun_ioctl; 153 ifp->if_output = tun_output; 154 #ifdef ALTQ 155 ifp->if_start = tunstart; 156 #endif 157 ifp->if_flags = IFF_POINTOPOINT; 158 ifp->if_snd.ifq_maxlen = ifqmaxlen; 159 ifp->if_collisions = 0; 160 ifp->if_ierrors = 0; 161 ifp->if_oerrors = 0; 162 ifp->if_ipackets = 0; 163 ifp->if_opackets = 0; 164 ifp->if_ibytes = 0; 165 ifp->if_obytes = 0; 166 ifp->if_dlt = DLT_NULL; 167 IFQ_SET_READY(&ifp->if_snd); 168 if_attach(ifp); 169 if_alloc_sadl(ifp); 170 #if NBPFILTER > 0 171 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 172 #endif 173 } 174 175 void 176 tun_clone_destroy(ifp) 177 struct ifnet *ifp; 178 { 179 struct tun_softc *tp = (void *)ifp; 180 181 simple_lock(&tun_softc_lock); 182 simple_lock(&tp->tun_lock); 183 LIST_REMOVE(tp, tun_list); 184 simple_unlock(&tp->tun_lock); 185 simple_unlock(&tun_softc_lock); 186 187 if (tp->tun_flags & TUN_RWAIT) { 188 tp->tun_flags &= ~TUN_RWAIT; 189 wakeup((caddr_t)tp); 190 } 191 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 192 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 193 194 selwakeup(&tp->tun_rsel); 195 196 #if NBPFILTER > 0 197 bpfdetach(ifp); 198 #endif 199 if_detach(ifp); 200 201 free(tp, M_DEVBUF); 202 } 203 204 static struct tun_softc * 205 tun_find_unit(dev) 206 dev_t dev; 207 { 208 struct tun_softc *tp; 209 int unit = minor(dev); 210 211 simple_lock(&tun_softc_lock); 212 LIST_FOREACH(tp, &tun_softc_list, tun_list) 213 if (unit == tp->tun_unit) 214 break; 215 if (tp) 216 simple_lock(&tp->tun_lock); 217 simple_unlock(&tun_softc_lock); 218 219 return (tp); 220 } 221 222 /* 223 * tunnel open - must be superuser & the device must be 224 * configured in 225 */ 226 int 227 tunopen(dev, flag, mode, p) 228 dev_t dev; 229 int flag, mode; 230 struct proc *p; 231 { 232 struct ifnet *ifp; 233 struct tun_softc *tp; 234 int error; 235 236 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 237 return (error); 238 239 if (NTUN < 1) 240 return (ENXIO); 241 242 tp = tun_find_unit(dev); 243 244 if (!tp) { 245 (void)tun_clone_create(&tun_cloner, minor(dev)); 246 tp = tun_find_unit(dev); 247 } 248 249 if (!tp) 250 return (ENXIO); 251 252 if (tp->tun_flags & TUN_OPEN) { 253 simple_unlock(&tp->tun_lock); 254 return (EBUSY); 255 } 256 257 ifp = &tp->tun_if; 258 tp->tun_flags |= TUN_OPEN; 259 TUNDEBUG("%s: open\n", ifp->if_xname); 260 simple_unlock(&tp->tun_lock); 261 return (0); 262 } 263 264 /* 265 * tunclose - close the device - mark i/f down & delete 266 * routing info 267 */ 268 int 269 tunclose(dev, flag, mode, p) 270 dev_t dev; 271 int flag; 272 int mode; 273 struct proc *p; 274 { 275 int s; 276 struct tun_softc *tp; 277 struct ifnet *ifp; 278 279 tp = tun_find_unit(dev); 280 281 /* interface was "destroyed" before the close */ 282 if (tp == NULL) 283 return (0); 284 285 ifp = &tp->tun_if; 286 287 tp->tun_flags &= ~TUN_OPEN; 288 289 /* 290 * junk all pending output 291 */ 292 s = splnet(); 293 IFQ_PURGE(&ifp->if_snd); 294 splx(s); 295 296 if (ifp->if_flags & IFF_UP) { 297 s = splnet(); 298 if_down(ifp); 299 if (ifp->if_flags & IFF_RUNNING) { 300 /* find internet addresses and delete routes */ 301 struct ifaddr *ifa; 302 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 303 #ifdef INET 304 if (ifa->ifa_addr->sa_family == AF_INET) { 305 rtinit(ifa, (int)RTM_DELETE, 306 tp->tun_flags & TUN_DSTADDR 307 ? RTF_HOST 308 : 0); 309 } 310 #endif 311 } 312 } 313 splx(s); 314 } 315 tp->tun_pgid = 0; 316 selnotify(&tp->tun_rsel, 0); 317 318 TUNDEBUG ("%s: closed\n", ifp->if_xname); 319 simple_unlock(&tp->tun_lock); 320 return (0); 321 } 322 323 static void 324 tuninit(tp) 325 struct tun_softc *tp; 326 { 327 struct ifnet *ifp = &tp->tun_if; 328 struct ifaddr *ifa; 329 330 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 331 332 ifp->if_flags |= IFF_UP | IFF_RUNNING; 333 334 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 335 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 336 #ifdef INET 337 if (ifa->ifa_addr->sa_family == AF_INET) { 338 struct sockaddr_in *sin; 339 340 sin = satosin(ifa->ifa_addr); 341 if (sin && sin->sin_addr.s_addr) 342 tp->tun_flags |= TUN_IASET; 343 344 if (ifp->if_flags & IFF_POINTOPOINT) { 345 sin = satosin(ifa->ifa_dstaddr); 346 if (sin && sin->sin_addr.s_addr) 347 tp->tun_flags |= TUN_DSTADDR; 348 } 349 } 350 #endif 351 } 352 353 return; 354 } 355 356 /* 357 * Process an ioctl request. 358 */ 359 int 360 tun_ioctl(ifp, cmd, data) 361 struct ifnet *ifp; 362 u_long cmd; 363 caddr_t data; 364 { 365 int error = 0, s; 366 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 367 368 simple_lock(&tp->tun_lock); 369 370 s = splnet(); 371 switch (cmd) { 372 case SIOCSIFADDR: 373 tuninit((struct tun_softc *)(ifp->if_softc)); 374 TUNDEBUG("%s: address set\n", ifp->if_xname); 375 break; 376 case SIOCSIFDSTADDR: 377 tuninit((struct tun_softc *)(ifp->if_softc)); 378 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 379 break; 380 case SIOCSIFBRDADDR: 381 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 382 break; 383 case SIOCSIFMTU: { 384 struct ifreq *ifr = (struct ifreq *) data; 385 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 386 error = EINVAL; 387 break; 388 } 389 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 390 ifp->if_mtu = ifr->ifr_mtu; 391 break; 392 } 393 case SIOCADDMULTI: 394 case SIOCDELMULTI: { 395 struct ifreq *ifr = (struct ifreq *) data; 396 if (ifr == 0) { 397 error = EAFNOSUPPORT; /* XXX */ 398 break; 399 } 400 switch (ifr->ifr_addr.sa_family) { 401 402 #ifdef INET 403 case AF_INET: 404 break; 405 #endif 406 407 default: 408 error = EAFNOSUPPORT; 409 break; 410 } 411 break; 412 } 413 case SIOCSIFFLAGS: 414 break; 415 default: 416 error = EINVAL; 417 } 418 splx(s); 419 simple_unlock(&tp->tun_lock); 420 return (error); 421 } 422 423 /* 424 * tun_output - queue packets from higher level ready to put out. 425 */ 426 int 427 tun_output(ifp, m0, dst, rt) 428 struct ifnet *ifp; 429 struct mbuf *m0; 430 struct sockaddr *dst; 431 struct rtentry *rt; 432 { 433 struct tun_softc *tp = ifp->if_softc; 434 #ifdef INET 435 int s; 436 int error; 437 #endif 438 int mlen; 439 ALTQ_DECL(struct altq_pktattr pktattr;) 440 441 simple_lock(&tp->tun_lock); 442 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 443 444 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 445 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 446 tp->tun_flags); 447 m_freem (m0); 448 simple_unlock(&tp->tun_lock); 449 return (EHOSTDOWN); 450 } 451 452 /* 453 * if the queueing discipline needs packet classification, 454 * do it before prepending link headers. 455 */ 456 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 457 458 #if NBPFILTER > 0 459 if (ifp->if_bpf) { 460 /* 461 * We need to prepend the address family as 462 * a four byte field. Cons up a dummy header 463 * to pacify bpf. This is safe because bpf 464 * will only read from the mbuf (i.e., it won't 465 * try to free it or keep a pointer to it). 466 */ 467 struct mbuf m; 468 u_int32_t af = dst->sa_family; 469 470 m.m_flags = 0; 471 m.m_next = m0; 472 m.m_len = sizeof(af); 473 m.m_data = (char *)⁡ 474 475 bpf_mtap(ifp->if_bpf, &m); 476 } 477 #endif 478 479 switch(dst->sa_family) { 480 #ifdef INET 481 case AF_INET: 482 if (tp->tun_flags & TUN_PREPADDR) { 483 /* Simple link-layer header */ 484 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 485 if (m0 == NULL) { 486 IF_DROP(&ifp->if_snd); 487 simple_unlock(&tp->tun_lock); 488 return (ENOBUFS); 489 } 490 bcopy(dst, mtod(m0, char *), dst->sa_len); 491 } 492 /* FALLTHROUGH */ 493 case AF_UNSPEC: 494 s = splnet(); 495 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 496 if (error) { 497 splx(s); 498 ifp->if_collisions++; 499 return (error); 500 } 501 mlen = m0->m_pkthdr.len; 502 splx(s); 503 ifp->if_opackets++; 504 ifp->if_obytes += mlen; 505 break; 506 #endif 507 default: 508 m_freem(m0); 509 simple_unlock(&tp->tun_lock); 510 return (EAFNOSUPPORT); 511 } 512 513 if (tp->tun_flags & TUN_RWAIT) { 514 tp->tun_flags &= ~TUN_RWAIT; 515 wakeup((caddr_t)tp); 516 } 517 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 518 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 519 NULL); 520 521 selnotify(&tp->tun_rsel, 0); 522 simple_unlock(&tp->tun_lock); 523 return (0); 524 } 525 526 /* 527 * the cdevsw interface is now pretty minimal. 528 */ 529 int 530 tunioctl(dev, cmd, data, flag, p) 531 dev_t dev; 532 u_long cmd; 533 caddr_t data; 534 int flag; 535 struct proc *p; 536 { 537 int s; 538 struct tun_softc *tp; 539 int error=0; 540 541 tp = tun_find_unit(dev); 542 543 /* interface was "destroyed" already */ 544 if (tp == NULL) 545 return (ENXIO); 546 547 switch (cmd) { 548 case TUNSDEBUG: 549 tundebug = *(int *)data; 550 break; 551 552 case TUNGDEBUG: 553 *(int *)data = tundebug; 554 break; 555 556 case TUNSIFMODE: 557 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 558 case IFF_POINTOPOINT: 559 case IFF_BROADCAST: 560 s = splnet(); 561 if (tp->tun_if.if_flags & IFF_UP) { 562 splx(s); 563 simple_unlock(&tp->tun_lock); 564 return (EBUSY); 565 } 566 tp->tun_if.if_flags &= 567 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 568 tp->tun_if.if_flags |= *(int *)data; 569 splx(s); 570 break; 571 default: 572 simple_unlock(&tp->tun_lock); 573 return (EINVAL); 574 } 575 break; 576 577 case TUNSLMODE: 578 if (*(int *)data) 579 tp->tun_flags |= TUN_PREPADDR; 580 else 581 tp->tun_flags &= ~TUN_PREPADDR; 582 break; 583 584 case FIONBIO: 585 if (*(int *)data) 586 tp->tun_flags |= TUN_NBIO; 587 else 588 tp->tun_flags &= ~TUN_NBIO; 589 break; 590 591 case FIOASYNC: 592 if (*(int *)data) 593 tp->tun_flags |= TUN_ASYNC; 594 else 595 tp->tun_flags &= ~TUN_ASYNC; 596 break; 597 598 case FIONREAD: 599 s = splnet(); 600 if (tp->tun_if.if_snd.ifq_head) 601 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 602 else 603 *(int *)data = 0; 604 splx(s); 605 break; 606 607 case TIOCSPGRP: 608 case FIOSETOWN: 609 error = fsetown(p, &tp->tun_pgid, cmd, data); 610 break; 611 612 case TIOCGPGRP: 613 case FIOGETOWN: 614 error = fgetown(p, tp->tun_pgid, cmd, data); 615 break; 616 617 default: 618 simple_unlock(&tp->tun_lock); 619 return (ENOTTY); 620 } 621 simple_unlock(&tp->tun_lock); 622 return (error); 623 } 624 625 /* 626 * The cdevsw read interface - reads a packet at a time, or at 627 * least as much of a packet as can be read. 628 */ 629 int 630 tunread(dev, uio, ioflag) 631 dev_t dev; 632 struct uio *uio; 633 int ioflag; 634 { 635 struct tun_softc *tp; 636 struct ifnet *ifp; 637 struct mbuf *m, *m0; 638 int error=0, len, s, index; 639 640 tp = tun_find_unit(dev); 641 642 /* interface was "destroyed" already */ 643 if (tp == NULL) 644 return (ENXIO); 645 646 index = tp->tun_if.if_index; 647 ifp = &tp->tun_if; 648 649 TUNDEBUG ("%s: read\n", ifp->if_xname); 650 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 651 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 652 simple_unlock(&tp->tun_lock); 653 return EHOSTDOWN; 654 } 655 656 tp->tun_flags &= ~TUN_RWAIT; 657 658 s = splnet(); 659 do { 660 IFQ_DEQUEUE(&ifp->if_snd, m0); 661 if (m0 == 0) { 662 if (tp->tun_flags & TUN_NBIO) { 663 splx(s); 664 simple_unlock(&tp->tun_lock); 665 return (EWOULDBLOCK); 666 } 667 tp->tun_flags |= TUN_RWAIT; 668 simple_unlock(&tp->tun_lock); 669 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 670 splx(s); 671 return (EINTR); 672 } else { 673 /* 674 * Maybe the interface was destroyed while 675 * we were sleeping, so let's ensure that 676 * we're looking at the same (valid) tun 677 * interface before looping. 678 */ 679 tp = tun_find_unit(dev); 680 if (tp == NULL || 681 tp->tun_if.if_index != index) { 682 splx(s); 683 if (tp) 684 simple_unlock(&tp->tun_lock); 685 return (ENXIO); 686 } 687 } 688 } 689 } while (m0 == 0); 690 splx(s); 691 692 while (m0 && uio->uio_resid > 0 && error == 0) { 693 len = min(uio->uio_resid, m0->m_len); 694 if (len != 0) 695 error = uiomove(mtod(m0, caddr_t), len, uio); 696 MFREE(m0, m); 697 m0 = m; 698 } 699 700 if (m0) { 701 TUNDEBUG("Dropping mbuf\n"); 702 m_freem(m0); 703 } 704 if (error) 705 ifp->if_ierrors++; 706 simple_unlock(&tp->tun_lock); 707 return (error); 708 } 709 710 /* 711 * the cdevsw write interface - an atomic write is a packet - or else! 712 */ 713 int 714 tunwrite(dev, uio, ioflag) 715 dev_t dev; 716 struct uio *uio; 717 int ioflag; 718 { 719 struct tun_softc *tp; 720 struct ifnet *ifp; 721 struct mbuf *top, **mp, *m; 722 struct ifqueue *ifq; 723 struct sockaddr dst; 724 int isr, error=0, s, tlen, mlen; 725 726 tp = tun_find_unit(dev); 727 728 /* interface was "destroyed" already */ 729 if (tp == NULL) 730 return (ENXIO); 731 732 ifp = &tp->tun_if; 733 734 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 735 736 if (tp->tun_flags & TUN_PREPADDR) { 737 if (uio->uio_resid < sizeof(dst)) { 738 simple_unlock(&tp->tun_lock); 739 return (EIO); 740 } 741 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 742 if (dst.sa_len > sizeof(dst)) { 743 /* Duh.. */ 744 char discard; 745 int n = dst.sa_len - sizeof(dst); 746 while (n--) 747 if ((error = uiomove(&discard, 1, uio)) != 0) { 748 simple_unlock(&tp->tun_lock); 749 return (error); 750 } 751 } 752 } else { 753 #ifdef INET 754 dst.sa_family = AF_INET; 755 #endif 756 } 757 758 if (uio->uio_resid > TUNMTU) { 759 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 760 (unsigned long)uio->uio_resid); 761 simple_unlock(&tp->tun_lock); 762 return (EIO); 763 } 764 765 switch (dst.sa_family) { 766 #ifdef INET 767 case AF_INET: 768 ifq = &ipintrq; 769 isr = NETISR_IP; 770 break; 771 #endif 772 default: 773 simple_unlock(&tp->tun_lock); 774 return (EAFNOSUPPORT); 775 } 776 777 tlen = uio->uio_resid; 778 779 /* get a header mbuf */ 780 MGETHDR(m, M_DONTWAIT, MT_DATA); 781 if (m == NULL) { 782 simple_unlock(&tp->tun_lock); 783 return (ENOBUFS); 784 } 785 mlen = MHLEN; 786 787 top = NULL; 788 mp = ⊤ 789 while (error == 0 && uio->uio_resid > 0) { 790 m->m_len = min(mlen, uio->uio_resid); 791 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 792 *mp = m; 793 mp = &m->m_next; 794 if (error == 0 && uio->uio_resid > 0) { 795 MGET(m, M_DONTWAIT, MT_DATA); 796 if (m == NULL) { 797 error = ENOBUFS; 798 break; 799 } 800 mlen = MLEN; 801 } 802 } 803 if (error) { 804 if (top != NULL) 805 m_freem (top); 806 ifp->if_ierrors++; 807 simple_unlock(&tp->tun_lock); 808 return (error); 809 } 810 811 top->m_pkthdr.len = tlen; 812 top->m_pkthdr.rcvif = ifp; 813 814 #if NBPFILTER > 0 815 if (ifp->if_bpf) { 816 /* 817 * We need to prepend the address family as 818 * a four byte field. Cons up a dummy header 819 * to pacify bpf. This is safe because bpf 820 * will only read from the mbuf (i.e., it won't 821 * try to free it or keep a pointer to it). 822 */ 823 struct mbuf m; 824 u_int32_t af = AF_INET; 825 826 m.m_flags = 0; 827 m.m_next = top; 828 m.m_len = sizeof(af); 829 m.m_data = (char *)⁡ 830 831 bpf_mtap(ifp->if_bpf, &m); 832 } 833 #endif 834 835 s = splnet(); 836 if (IF_QFULL(ifq)) { 837 IF_DROP(ifq); 838 splx(s); 839 ifp->if_collisions++; 840 m_freem(top); 841 simple_unlock(&tp->tun_lock); 842 return (ENOBUFS); 843 } 844 IF_ENQUEUE(ifq, top); 845 splx(s); 846 ifp->if_ipackets++; 847 ifp->if_ibytes += tlen; 848 schednetisr(isr); 849 simple_unlock(&tp->tun_lock); 850 return (error); 851 } 852 853 #ifdef ALTQ 854 /* 855 * Start packet transmission on the interface. 856 * when the interface queue is rate-limited by ALTQ or TBR, 857 * if_start is needed to drain packets from the queue in order 858 * to notify readers when outgoing packets become ready. 859 */ 860 static void 861 tunstart(ifp) 862 struct ifnet *ifp; 863 { 864 struct tun_softc *tp = ifp->if_softc; 865 struct mbuf *m; 866 867 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 868 return; 869 870 IFQ_POLL(&ifp->if_snd, m); 871 if (m != NULL) { 872 if (tp->tun_flags & TUN_RWAIT) { 873 tp->tun_flags &= ~TUN_RWAIT; 874 wakeup((caddr_t)tp); 875 } 876 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 877 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 878 POLLOUT|POLLWRNORM, NULL); 879 880 selwakeup(&tp->tun_rsel); 881 } 882 } 883 #endif /* ALTQ */ 884 /* 885 * tunpoll - the poll interface, this is only useful on reads 886 * really. The write detect always returns true, write never blocks 887 * anyway, it either accepts the packet or drops it. 888 */ 889 int 890 tunpoll(dev, events, p) 891 dev_t dev; 892 int events; 893 struct proc *p; 894 { 895 struct tun_softc *tp; 896 struct ifnet *ifp; 897 int s, revents = 0; 898 899 tp = tun_find_unit(dev); 900 901 /* interface was "destroyed" already */ 902 if (tp == NULL) 903 return (0); 904 905 ifp = &tp->tun_if; 906 907 s = splnet(); 908 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 909 910 if (events & (POLLIN | POLLRDNORM)) { 911 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 912 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 913 ifp->if_snd.ifq_len); 914 revents |= events & (POLLIN | POLLRDNORM); 915 } else { 916 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 917 selrecord(p, &tp->tun_rsel); 918 } 919 } 920 921 if (events & (POLLOUT | POLLWRNORM)) 922 revents |= events & (POLLOUT | POLLWRNORM); 923 924 splx(s); 925 simple_unlock(&tp->tun_lock); 926 return (revents); 927 } 928 929 static void 930 filt_tunrdetach(struct knote *kn) 931 { 932 struct tun_softc *tp = kn->kn_hook; 933 int s; 934 935 s = splnet(); 936 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 937 splx(s); 938 } 939 940 static int 941 filt_tunread(struct knote *kn, long hint) 942 { 943 struct tun_softc *tp = kn->kn_hook; 944 struct ifnet *ifp = &tp->tun_if; 945 struct mbuf *m; 946 int s; 947 948 s = splnet(); 949 IF_POLL(&ifp->if_snd, m); 950 if (m == NULL) { 951 splx(s); 952 return (0); 953 } 954 955 for (kn->kn_data = 0; m != NULL; m = m->m_next) 956 kn->kn_data += m->m_len; 957 958 splx(s); 959 return (1); 960 } 961 962 static const struct filterops tunread_filtops = 963 { 1, NULL, filt_tunrdetach, filt_tunread }; 964 965 static const struct filterops tun_seltrue_filtops = 966 { 1, NULL, filt_tunrdetach, filt_seltrue }; 967 968 int 969 tunkqfilter(dev_t dev, struct knote *kn) 970 { 971 struct tun_softc *tp = tun_find_unit(dev); 972 struct klist *klist; 973 int s; 974 975 switch (kn->kn_filter) { 976 case EVFILT_READ: 977 klist = &tp->tun_rsel.sel_klist; 978 kn->kn_fop = &tunread_filtops; 979 break; 980 981 case EVFILT_WRITE: 982 klist = &tp->tun_rsel.sel_klist; 983 kn->kn_fop = &tun_seltrue_filtops; 984 break; 985 986 default: 987 return (1); 988 } 989 990 kn->kn_hook = tp; 991 992 s = splnet(); 993 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 994 splx(s); 995 996 return (0); 997 } 998
Indexes created Tue Sep 23 23:09:58 GMT 2025