if_tun.c revision 1.62
1 /* $NetBSD: if_tun.c,v 1.62 2003/06/28 14:22:07 darrenr 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 1.62 2003/06/28 14:22:07 darrenr 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 struct proc *p; 181 182 simple_lock(&tun_softc_lock); 183 simple_lock(&tp->tun_lock); 184 LIST_REMOVE(tp, tun_list); 185 simple_unlock(&tp->tun_lock); 186 simple_unlock(&tun_softc_lock); 187 188 if (tp->tun_flags & TUN_RWAIT) { 189 tp->tun_flags &= ~TUN_RWAIT; 190 wakeup((caddr_t)tp); 191 } 192 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 193 if (tp->tun_pgrp > 0) 194 gsignal(tp->tun_pgrp, SIGIO); 195 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 196 psignal(p, SIGIO); 197 } 198 selwakeup(&tp->tun_rsel); 199 200 #if NBPFILTER > 0 201 bpfdetach(ifp); 202 #endif 203 if_detach(ifp); 204 205 free(tp, M_DEVBUF); 206 } 207 208 static struct tun_softc * 209 tun_find_unit(dev) 210 dev_t dev; 211 { 212 struct tun_softc *tp; 213 int unit = minor(dev); 214 215 simple_lock(&tun_softc_lock); 216 LIST_FOREACH(tp, &tun_softc_list, tun_list) 217 if (unit == tp->tun_unit) 218 break; 219 if (tp) 220 simple_lock(&tp->tun_lock); 221 simple_unlock(&tun_softc_lock); 222 223 return (tp); 224 } 225 226 /* 227 * tunnel open - must be superuser & the device must be 228 * configured in 229 */ 230 int 231 tunopen(dev, flag, mode, l) 232 dev_t dev; 233 int flag, mode; 234 struct lwp *l; 235 { 236 struct proc *p = l->l_proc; 237 struct ifnet *ifp; 238 struct tun_softc *tp; 239 int error; 240 241 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 242 return (error); 243 244 if (NTUN < 1) 245 return (ENXIO); 246 247 tp = tun_find_unit(dev); 248 249 if (!tp) { 250 (void)tun_clone_create(&tun_cloner, minor(dev)); 251 tp = tun_find_unit(dev); 252 } 253 254 if (!tp) 255 return (ENXIO); 256 257 if (tp->tun_flags & TUN_OPEN) { 258 simple_unlock(&tp->tun_lock); 259 return (EBUSY); 260 } 261 262 ifp = &tp->tun_if; 263 tp->tun_flags |= TUN_OPEN; 264 TUNDEBUG("%s: open\n", ifp->if_xname); 265 simple_unlock(&tp->tun_lock); 266 return (0); 267 } 268 269 /* 270 * tunclose - close the device - mark i/f down & delete 271 * routing info 272 */ 273 int 274 tunclose(dev, flag, mode, l) 275 dev_t dev; 276 int flag; 277 int mode; 278 struct lwp *l; 279 { 280 int s; 281 struct tun_softc *tp; 282 struct ifnet *ifp; 283 284 tp = tun_find_unit(dev); 285 286 /* interface was "destroyed" before the close */ 287 if (tp == NULL) 288 return (0); 289 290 ifp = &tp->tun_if; 291 292 tp->tun_flags &= ~TUN_OPEN; 293 294 /* 295 * junk all pending output 296 */ 297 s = splnet(); 298 IFQ_PURGE(&ifp->if_snd); 299 splx(s); 300 301 if (ifp->if_flags & IFF_UP) { 302 s = splnet(); 303 if_down(ifp); 304 if (ifp->if_flags & IFF_RUNNING) { 305 /* find internet addresses and delete routes */ 306 struct ifaddr *ifa; 307 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 308 #ifdef INET 309 if (ifa->ifa_addr->sa_family == AF_INET) { 310 rtinit(ifa, (int)RTM_DELETE, 311 tp->tun_flags & TUN_DSTADDR 312 ? RTF_HOST 313 : 0); 314 } 315 #endif 316 } 317 } 318 splx(s); 319 } 320 tp->tun_pgrp = 0; 321 selnotify(&tp->tun_rsel, 0); 322 323 TUNDEBUG ("%s: closed\n", ifp->if_xname); 324 simple_unlock(&tp->tun_lock); 325 return (0); 326 } 327 328 static void 329 tuninit(tp) 330 struct tun_softc *tp; 331 { 332 struct ifnet *ifp = &tp->tun_if; 333 struct ifaddr *ifa; 334 335 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 336 337 ifp->if_flags |= IFF_UP | IFF_RUNNING; 338 339 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 340 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 341 #ifdef INET 342 if (ifa->ifa_addr->sa_family == AF_INET) { 343 struct sockaddr_in *sin; 344 345 sin = satosin(ifa->ifa_addr); 346 if (sin && sin->sin_addr.s_addr) 347 tp->tun_flags |= TUN_IASET; 348 349 if (ifp->if_flags & IFF_POINTOPOINT) { 350 sin = satosin(ifa->ifa_dstaddr); 351 if (sin && sin->sin_addr.s_addr) 352 tp->tun_flags |= TUN_DSTADDR; 353 } 354 } 355 #endif 356 } 357 358 return; 359 } 360 361 /* 362 * Process an ioctl request. 363 */ 364 int 365 tun_ioctl(ifp, cmd, data) 366 struct ifnet *ifp; 367 u_long cmd; 368 caddr_t data; 369 { 370 int error = 0, s; 371 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 372 373 simple_lock(&tp->tun_lock); 374 375 s = splnet(); 376 switch (cmd) { 377 case SIOCSIFADDR: 378 tuninit((struct tun_softc *)(ifp->if_softc)); 379 TUNDEBUG("%s: address set\n", ifp->if_xname); 380 break; 381 case SIOCSIFDSTADDR: 382 tuninit((struct tun_softc *)(ifp->if_softc)); 383 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 384 break; 385 case SIOCSIFBRDADDR: 386 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 387 break; 388 case SIOCSIFMTU: { 389 struct ifreq *ifr = (struct ifreq *) data; 390 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 391 error = EINVAL; 392 break; 393 } 394 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 395 ifp->if_mtu = ifr->ifr_mtu; 396 break; 397 } 398 case SIOCADDMULTI: 399 case SIOCDELMULTI: { 400 struct ifreq *ifr = (struct ifreq *) data; 401 if (ifr == 0) { 402 error = EAFNOSUPPORT; /* XXX */ 403 break; 404 } 405 switch (ifr->ifr_addr.sa_family) { 406 407 #ifdef INET 408 case AF_INET: 409 break; 410 #endif 411 412 default: 413 error = EAFNOSUPPORT; 414 break; 415 } 416 break; 417 } 418 case SIOCSIFFLAGS: 419 break; 420 default: 421 error = EINVAL; 422 } 423 splx(s); 424 simple_unlock(&tp->tun_lock); 425 return (error); 426 } 427 428 /* 429 * tun_output - queue packets from higher level ready to put out. 430 */ 431 int 432 tun_output(ifp, m0, dst, rt) 433 struct ifnet *ifp; 434 struct mbuf *m0; 435 struct sockaddr *dst; 436 struct rtentry *rt; 437 { 438 struct tun_softc *tp = ifp->if_softc; 439 struct proc *p; 440 #ifdef INET 441 int s; 442 int error; 443 #endif 444 int mlen; 445 ALTQ_DECL(struct altq_pktattr pktattr;) 446 447 simple_lock(&tp->tun_lock); 448 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 449 450 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 451 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 452 tp->tun_flags); 453 m_freem (m0); 454 simple_unlock(&tp->tun_lock); 455 return (EHOSTDOWN); 456 } 457 458 /* 459 * if the queueing discipline needs packet classification, 460 * do it before prepending link headers. 461 */ 462 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 463 464 #if NBPFILTER > 0 465 if (ifp->if_bpf) { 466 /* 467 * We need to prepend the address family as 468 * a four byte field. Cons up a dummy header 469 * to pacify bpf. This is safe because bpf 470 * will only read from the mbuf (i.e., it won't 471 * try to free it or keep a pointer to it). 472 */ 473 struct mbuf m; 474 u_int32_t af = dst->sa_family; 475 476 m.m_flags = 0; 477 m.m_next = m0; 478 m.m_len = sizeof(af); 479 m.m_data = (char *)⁡ 480 481 bpf_mtap(ifp->if_bpf, &m); 482 } 483 #endif 484 485 switch(dst->sa_family) { 486 #ifdef INET 487 case AF_INET: 488 if (tp->tun_flags & TUN_PREPADDR) { 489 /* Simple link-layer header */ 490 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 491 if (m0 == NULL) { 492 IF_DROP(&ifp->if_snd); 493 simple_unlock(&tp->tun_lock); 494 return (ENOBUFS); 495 } 496 bcopy(dst, mtod(m0, char *), dst->sa_len); 497 } 498 /* FALLTHROUGH */ 499 case AF_UNSPEC: 500 s = splnet(); 501 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 502 if (error) { 503 splx(s); 504 ifp->if_collisions++; 505 return (error); 506 } 507 mlen = m0->m_pkthdr.len; 508 splx(s); 509 ifp->if_opackets++; 510 ifp->if_obytes += mlen; 511 break; 512 #endif 513 default: 514 m_freem(m0); 515 simple_unlock(&tp->tun_lock); 516 return (EAFNOSUPPORT); 517 } 518 519 if (tp->tun_flags & TUN_RWAIT) { 520 tp->tun_flags &= ~TUN_RWAIT; 521 wakeup((caddr_t)tp); 522 } 523 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 524 if (tp->tun_pgrp > 0) 525 gsignal(tp->tun_pgrp, SIGIO); 526 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 527 psignal(p, SIGIO); 528 } 529 selnotify(&tp->tun_rsel, 0); 530 simple_unlock(&tp->tun_lock); 531 return (0); 532 } 533 534 /* 535 * the cdevsw interface is now pretty minimal. 536 */ 537 int 538 tunioctl(dev, cmd, data, flag, l) 539 dev_t dev; 540 u_long cmd; 541 caddr_t data; 542 int flag; 543 struct lwp *l; 544 { 545 int s; 546 struct tun_softc *tp; 547 pid_t pgid; 548 int error; 549 550 tp = tun_find_unit(dev); 551 552 /* interface was "destroyed" already */ 553 if (tp == NULL) 554 return (ENXIO); 555 556 switch (cmd) { 557 case TUNSDEBUG: 558 tundebug = *(int *)data; 559 break; 560 561 case TUNGDEBUG: 562 *(int *)data = tundebug; 563 break; 564 565 case TUNSIFMODE: 566 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 567 case IFF_POINTOPOINT: 568 case IFF_BROADCAST: 569 s = splnet(); 570 if (tp->tun_if.if_flags & IFF_UP) { 571 splx(s); 572 simple_unlock(&tp->tun_lock); 573 return (EBUSY); 574 } 575 tp->tun_if.if_flags &= 576 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 577 tp->tun_if.if_flags |= *(int *)data; 578 splx(s); 579 break; 580 default: 581 simple_unlock(&tp->tun_lock); 582 return (EINVAL); 583 } 584 break; 585 586 case TUNSLMODE: 587 if (*(int *)data) 588 tp->tun_flags |= TUN_PREPADDR; 589 else 590 tp->tun_flags &= ~TUN_PREPADDR; 591 break; 592 593 case FIONBIO: 594 if (*(int *)data) 595 tp->tun_flags |= TUN_NBIO; 596 else 597 tp->tun_flags &= ~TUN_NBIO; 598 break; 599 600 case FIOASYNC: 601 if (*(int *)data) 602 tp->tun_flags |= TUN_ASYNC; 603 else 604 tp->tun_flags &= ~TUN_ASYNC; 605 break; 606 607 case FIONREAD: 608 s = splnet(); 609 if (tp->tun_if.if_snd.ifq_head) 610 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 611 else 612 *(int *)data = 0; 613 splx(s); 614 break; 615 616 case TIOCSPGRP: 617 pgid = *(int *)data; 618 if (pgid != 0) { 619 error = pgid_in_session(l->l_proc, pgid); 620 if (error != 0) 621 return error; 622 } 623 tp->tun_pgrp = pgid; 624 break; 625 626 case TIOCGPGRP: 627 *(int *)data = tp->tun_pgrp; 628 break; 629 630 default: 631 simple_unlock(&tp->tun_lock); 632 return (ENOTTY); 633 } 634 simple_unlock(&tp->tun_lock); 635 return (0); 636 } 637 638 /* 639 * The cdevsw read interface - reads a packet at a time, or at 640 * least as much of a packet as can be read. 641 */ 642 int 643 tunread(dev, uio, ioflag) 644 dev_t dev; 645 struct uio *uio; 646 int ioflag; 647 { 648 struct tun_softc *tp; 649 struct ifnet *ifp; 650 struct mbuf *m, *m0; 651 int error=0, len, s, index; 652 653 tp = tun_find_unit(dev); 654 655 /* interface was "destroyed" already */ 656 if (tp == NULL) 657 return (ENXIO); 658 659 index = tp->tun_if.if_index; 660 ifp = &tp->tun_if; 661 662 TUNDEBUG ("%s: read\n", ifp->if_xname); 663 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 664 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 665 simple_unlock(&tp->tun_lock); 666 return EHOSTDOWN; 667 } 668 669 tp->tun_flags &= ~TUN_RWAIT; 670 671 s = splnet(); 672 do { 673 IFQ_DEQUEUE(&ifp->if_snd, m0); 674 if (m0 == 0) { 675 if (tp->tun_flags & TUN_NBIO) { 676 splx(s); 677 simple_unlock(&tp->tun_lock); 678 return (EWOULDBLOCK); 679 } 680 tp->tun_flags |= TUN_RWAIT; 681 simple_unlock(&tp->tun_lock); 682 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 683 splx(s); 684 return (EINTR); 685 } else { 686 /* 687 * Maybe the interface was destroyed while 688 * we were sleeping, so let's ensure that 689 * we're looking at the same (valid) tun 690 * interface before looping. 691 */ 692 tp = tun_find_unit(dev); 693 if (tp == NULL || 694 tp->tun_if.if_index != index) { 695 splx(s); 696 if (tp) 697 simple_unlock(&tp->tun_lock); 698 return (ENXIO); 699 } 700 } 701 } 702 } while (m0 == 0); 703 splx(s); 704 705 while (m0 && uio->uio_resid > 0 && error == 0) { 706 len = min(uio->uio_resid, m0->m_len); 707 if (len != 0) 708 error = uiomove(mtod(m0, caddr_t), len, uio); 709 MFREE(m0, m); 710 m0 = m; 711 } 712 713 if (m0) { 714 TUNDEBUG("Dropping mbuf\n"); 715 m_freem(m0); 716 } 717 if (error) 718 ifp->if_ierrors++; 719 simple_unlock(&tp->tun_lock); 720 return (error); 721 } 722 723 /* 724 * the cdevsw write interface - an atomic write is a packet - or else! 725 */ 726 int 727 tunwrite(dev, uio, ioflag) 728 dev_t dev; 729 struct uio *uio; 730 int ioflag; 731 { 732 struct tun_softc *tp; 733 struct ifnet *ifp; 734 struct mbuf *top, **mp, *m; 735 struct ifqueue *ifq; 736 struct sockaddr dst; 737 int isr, error=0, s, tlen, mlen; 738 739 tp = tun_find_unit(dev); 740 741 /* interface was "destroyed" already */ 742 if (tp == NULL) 743 return (ENXIO); 744 745 ifp = &tp->tun_if; 746 747 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 748 749 if (tp->tun_flags & TUN_PREPADDR) { 750 if (uio->uio_resid < sizeof(dst)) { 751 simple_unlock(&tp->tun_lock); 752 return (EIO); 753 } 754 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 755 if (dst.sa_len > sizeof(dst)) { 756 /* Duh.. */ 757 char discard; 758 int n = dst.sa_len - sizeof(dst); 759 while (n--) 760 if ((error = uiomove(&discard, 1, uio)) != 0) { 761 simple_unlock(&tp->tun_lock); 762 return (error); 763 } 764 } 765 } else { 766 #ifdef INET 767 dst.sa_family = AF_INET; 768 #endif 769 } 770 771 if (uio->uio_resid > TUNMTU) { 772 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 773 (unsigned long)uio->uio_resid); 774 simple_unlock(&tp->tun_lock); 775 return (EIO); 776 } 777 778 switch (dst.sa_family) { 779 #ifdef INET 780 case AF_INET: 781 ifq = &ipintrq; 782 isr = NETISR_IP; 783 break; 784 #endif 785 default: 786 simple_unlock(&tp->tun_lock); 787 return (EAFNOSUPPORT); 788 } 789 790 tlen = uio->uio_resid; 791 792 /* get a header mbuf */ 793 MGETHDR(m, M_DONTWAIT, MT_DATA); 794 if (m == NULL) { 795 simple_unlock(&tp->tun_lock); 796 return (ENOBUFS); 797 } 798 mlen = MHLEN; 799 800 top = 0; 801 mp = ⊤ 802 while (error == 0 && uio->uio_resid > 0) { 803 m->m_len = min(mlen, uio->uio_resid); 804 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 805 *mp = m; 806 mp = &m->m_next; 807 if (uio->uio_resid > 0) { 808 MGET (m, M_DONTWAIT, MT_DATA); 809 if (m == 0) { 810 error = ENOBUFS; 811 break; 812 } 813 mlen = MLEN; 814 } 815 } 816 if (error) { 817 if (top) 818 m_freem (top); 819 ifp->if_ierrors++; 820 simple_unlock(&tp->tun_lock); 821 return (error); 822 } 823 824 top->m_pkthdr.len = tlen; 825 top->m_pkthdr.rcvif = ifp; 826 827 #if NBPFILTER > 0 828 if (ifp->if_bpf) { 829 /* 830 * We need to prepend the address family as 831 * a four byte field. Cons up a dummy header 832 * to pacify bpf. This is safe because bpf 833 * will only read from the mbuf (i.e., it won't 834 * try to free it or keep a pointer to it). 835 */ 836 struct mbuf m; 837 u_int32_t af = AF_INET; 838 839 m.m_flags = 0; 840 m.m_next = top; 841 m.m_len = sizeof(af); 842 m.m_data = (char *)⁡ 843 844 bpf_mtap(ifp->if_bpf, &m); 845 } 846 #endif 847 848 s = splnet(); 849 if (IF_QFULL(ifq)) { 850 IF_DROP(ifq); 851 splx(s); 852 ifp->if_collisions++; 853 m_freem(top); 854 simple_unlock(&tp->tun_lock); 855 return (ENOBUFS); 856 } 857 IF_ENQUEUE(ifq, top); 858 splx(s); 859 ifp->if_ipackets++; 860 ifp->if_ibytes += tlen; 861 schednetisr(isr); 862 simple_unlock(&tp->tun_lock); 863 return (error); 864 } 865 866 #ifdef ALTQ 867 /* 868 * Start packet transmission on the interface. 869 * when the interface queue is rate-limited by ALTQ or TBR, 870 * if_start is needed to drain packets from the queue in order 871 * to notify readers when outgoing packets become ready. 872 */ 873 static void 874 tunstart(ifp) 875 struct ifnet *ifp; 876 { 877 struct tun_softc *tp = ifp->if_softc; 878 struct mbuf *m; 879 struct proc *p; 880 881 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 882 return; 883 884 IFQ_POLL(&ifp->if_snd, m); 885 if (m != NULL) { 886 if (tp->tun_flags & TUN_RWAIT) { 887 tp->tun_flags &= ~TUN_RWAIT; 888 wakeup((caddr_t)tp); 889 } 890 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 891 if (tp->tun_pgrp > 0) 892 gsignal(tp->tun_pgrp, SIGIO); 893 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 894 psignal(p, SIGIO); 895 } 896 selwakeup(&tp->tun_rsel); 897 } 898 } 899 #endif /* ALTQ */ 900 /* 901 * tunpoll - the poll interface, this is only useful on reads 902 * really. The write detect always returns true, write never blocks 903 * anyway, it either accepts the packet or drops it. 904 */ 905 int 906 tunpoll(dev, events, l) 907 dev_t dev; 908 int events; 909 struct lwp *l; 910 { 911 struct tun_softc *tp; 912 struct ifnet *ifp; 913 int s, revents = 0; 914 915 tp = tun_find_unit(dev); 916 917 /* interface was "destroyed" already */ 918 if (tp == NULL) 919 return (0); 920 921 ifp = &tp->tun_if; 922 923 s = splnet(); 924 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 925 926 if (events & (POLLIN | POLLRDNORM)) { 927 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 928 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 929 ifp->if_snd.ifq_len); 930 revents |= events & (POLLIN | POLLRDNORM); 931 } else { 932 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 933 selrecord(l, &tp->tun_rsel); 934 } 935 } 936 937 if (events & (POLLOUT | POLLWRNORM)) 938 revents |= events & (POLLOUT | POLLWRNORM); 939 940 splx(s); 941 simple_unlock(&tp->tun_lock); 942 return (revents); 943 } 944 945 static void 946 filt_tunrdetach(struct knote *kn) 947 { 948 struct tun_softc *tp = kn->kn_hook; 949 int s; 950 951 s = splnet(); 952 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 953 splx(s); 954 } 955 956 static int 957 filt_tunread(struct knote *kn, long hint) 958 { 959 struct tun_softc *tp = kn->kn_hook; 960 struct ifnet *ifp = &tp->tun_if; 961 struct mbuf *m; 962 int s; 963 964 s = splnet(); 965 IF_POLL(&ifp->if_snd, m); 966 if (m == NULL) { 967 splx(s); 968 return (0); 969 } 970 971 for (kn->kn_data = 0; m != NULL; m = m->m_next) 972 kn->kn_data += m->m_len; 973 974 splx(s); 975 return (1); 976 } 977 978 static const struct filterops tunread_filtops = 979 { 1, NULL, filt_tunrdetach, filt_tunread }; 980 981 static const struct filterops tun_seltrue_filtops = 982 { 1, NULL, filt_tunrdetach, filt_seltrue }; 983 984 int 985 tunkqfilter(dev_t dev, struct knote *kn) 986 { 987 struct tun_softc *tp = tun_find_unit(dev); 988 struct klist *klist; 989 int s; 990 991 switch (kn->kn_filter) { 992 case EVFILT_READ: 993 klist = &tp->tun_rsel.sel_klist; 994 kn->kn_fop = &tunread_filtops; 995 break; 996 997 case EVFILT_WRITE: 998 klist = &tp->tun_rsel.sel_klist; 999 kn->kn_fop = &tun_seltrue_filtops; 1000 break; 1001 1002 default: 1003 return (1); 1004 } 1005 1006 kn->kn_hook = tp; 1007 1008 s = splnet(); 1009 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1010 splx(s); 1011 1012 return (0); 1013 } 1014
Indexes created Thu Sep 25 16:09:42 GMT 2025