if_tun.c revision 1.63
1 /* $NetBSD: if_tun.c,v 1.63 2003/06/29 22:31:51 fvdl 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 1.63 2003/06/29 22:31:51 fvdl 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, p) 232 dev_t dev; 233 int flag, mode; 234 struct proc *p; 235 { 236 struct ifnet *ifp; 237 struct tun_softc *tp; 238 int error; 239 240 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 241 return (error); 242 243 if (NTUN < 1) 244 return (ENXIO); 245 246 tp = tun_find_unit(dev); 247 248 if (!tp) { 249 (void)tun_clone_create(&tun_cloner, minor(dev)); 250 tp = tun_find_unit(dev); 251 } 252 253 if (!tp) 254 return (ENXIO); 255 256 if (tp->tun_flags & TUN_OPEN) { 257 simple_unlock(&tp->tun_lock); 258 return (EBUSY); 259 } 260 261 ifp = &tp->tun_if; 262 tp->tun_flags |= TUN_OPEN; 263 TUNDEBUG("%s: open\n", ifp->if_xname); 264 simple_unlock(&tp->tun_lock); 265 return (0); 266 } 267 268 /* 269 * tunclose - close the device - mark i/f down & delete 270 * routing info 271 */ 272 int 273 tunclose(dev, flag, mode, p) 274 dev_t dev; 275 int flag; 276 int mode; 277 struct proc *p; 278 { 279 int s; 280 struct tun_softc *tp; 281 struct ifnet *ifp; 282 283 tp = tun_find_unit(dev); 284 285 /* interface was "destroyed" before the close */ 286 if (tp == NULL) 287 return (0); 288 289 ifp = &tp->tun_if; 290 291 tp->tun_flags &= ~TUN_OPEN; 292 293 /* 294 * junk all pending output 295 */ 296 s = splnet(); 297 IFQ_PURGE(&ifp->if_snd); 298 splx(s); 299 300 if (ifp->if_flags & IFF_UP) { 301 s = splnet(); 302 if_down(ifp); 303 if (ifp->if_flags & IFF_RUNNING) { 304 /* find internet addresses and delete routes */ 305 struct ifaddr *ifa; 306 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 307 #ifdef INET 308 if (ifa->ifa_addr->sa_family == AF_INET) { 309 rtinit(ifa, (int)RTM_DELETE, 310 tp->tun_flags & TUN_DSTADDR 311 ? RTF_HOST 312 : 0); 313 } 314 #endif 315 } 316 } 317 splx(s); 318 } 319 tp->tun_pgrp = 0; 320 selnotify(&tp->tun_rsel, 0); 321 322 TUNDEBUG ("%s: closed\n", ifp->if_xname); 323 simple_unlock(&tp->tun_lock); 324 return (0); 325 } 326 327 static void 328 tuninit(tp) 329 struct tun_softc *tp; 330 { 331 struct ifnet *ifp = &tp->tun_if; 332 struct ifaddr *ifa; 333 334 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 335 336 ifp->if_flags |= IFF_UP | IFF_RUNNING; 337 338 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 339 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 340 #ifdef INET 341 if (ifa->ifa_addr->sa_family == AF_INET) { 342 struct sockaddr_in *sin; 343 344 sin = satosin(ifa->ifa_addr); 345 if (sin && sin->sin_addr.s_addr) 346 tp->tun_flags |= TUN_IASET; 347 348 if (ifp->if_flags & IFF_POINTOPOINT) { 349 sin = satosin(ifa->ifa_dstaddr); 350 if (sin && sin->sin_addr.s_addr) 351 tp->tun_flags |= TUN_DSTADDR; 352 } 353 } 354 #endif 355 } 356 357 return; 358 } 359 360 /* 361 * Process an ioctl request. 362 */ 363 int 364 tun_ioctl(ifp, cmd, data) 365 struct ifnet *ifp; 366 u_long cmd; 367 caddr_t data; 368 { 369 int error = 0, s; 370 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 371 372 simple_lock(&tp->tun_lock); 373 374 s = splnet(); 375 switch (cmd) { 376 case SIOCSIFADDR: 377 tuninit((struct tun_softc *)(ifp->if_softc)); 378 TUNDEBUG("%s: address set\n", ifp->if_xname); 379 break; 380 case SIOCSIFDSTADDR: 381 tuninit((struct tun_softc *)(ifp->if_softc)); 382 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 383 break; 384 case SIOCSIFBRDADDR: 385 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 386 break; 387 case SIOCSIFMTU: { 388 struct ifreq *ifr = (struct ifreq *) data; 389 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 390 error = EINVAL; 391 break; 392 } 393 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 394 ifp->if_mtu = ifr->ifr_mtu; 395 break; 396 } 397 case SIOCADDMULTI: 398 case SIOCDELMULTI: { 399 struct ifreq *ifr = (struct ifreq *) data; 400 if (ifr == 0) { 401 error = EAFNOSUPPORT; /* XXX */ 402 break; 403 } 404 switch (ifr->ifr_addr.sa_family) { 405 406 #ifdef INET 407 case AF_INET: 408 break; 409 #endif 410 411 default: 412 error = EAFNOSUPPORT; 413 break; 414 } 415 break; 416 } 417 case SIOCSIFFLAGS: 418 break; 419 default: 420 error = EINVAL; 421 } 422 splx(s); 423 simple_unlock(&tp->tun_lock); 424 return (error); 425 } 426 427 /* 428 * tun_output - queue packets from higher level ready to put out. 429 */ 430 int 431 tun_output(ifp, m0, dst, rt) 432 struct ifnet *ifp; 433 struct mbuf *m0; 434 struct sockaddr *dst; 435 struct rtentry *rt; 436 { 437 struct tun_softc *tp = ifp->if_softc; 438 struct proc *p; 439 #ifdef INET 440 int s; 441 int error; 442 #endif 443 int mlen; 444 ALTQ_DECL(struct altq_pktattr pktattr;) 445 446 simple_lock(&tp->tun_lock); 447 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 448 449 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 450 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 451 tp->tun_flags); 452 m_freem (m0); 453 simple_unlock(&tp->tun_lock); 454 return (EHOSTDOWN); 455 } 456 457 /* 458 * if the queueing discipline needs packet classification, 459 * do it before prepending link headers. 460 */ 461 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 462 463 #if NBPFILTER > 0 464 if (ifp->if_bpf) { 465 /* 466 * We need to prepend the address family as 467 * a four byte field. Cons up a dummy header 468 * to pacify bpf. This is safe because bpf 469 * will only read from the mbuf (i.e., it won't 470 * try to free it or keep a pointer to it). 471 */ 472 struct mbuf m; 473 u_int32_t af = dst->sa_family; 474 475 m.m_flags = 0; 476 m.m_next = m0; 477 m.m_len = sizeof(af); 478 m.m_data = (char *)⁡ 479 480 bpf_mtap(ifp->if_bpf, &m); 481 } 482 #endif 483 484 switch(dst->sa_family) { 485 #ifdef INET 486 case AF_INET: 487 if (tp->tun_flags & TUN_PREPADDR) { 488 /* Simple link-layer header */ 489 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 490 if (m0 == NULL) { 491 IF_DROP(&ifp->if_snd); 492 simple_unlock(&tp->tun_lock); 493 return (ENOBUFS); 494 } 495 bcopy(dst, mtod(m0, char *), dst->sa_len); 496 } 497 /* FALLTHROUGH */ 498 case AF_UNSPEC: 499 s = splnet(); 500 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 501 if (error) { 502 splx(s); 503 ifp->if_collisions++; 504 return (error); 505 } 506 mlen = m0->m_pkthdr.len; 507 splx(s); 508 ifp->if_opackets++; 509 ifp->if_obytes += mlen; 510 break; 511 #endif 512 default: 513 m_freem(m0); 514 simple_unlock(&tp->tun_lock); 515 return (EAFNOSUPPORT); 516 } 517 518 if (tp->tun_flags & TUN_RWAIT) { 519 tp->tun_flags &= ~TUN_RWAIT; 520 wakeup((caddr_t)tp); 521 } 522 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 523 if (tp->tun_pgrp > 0) 524 gsignal(tp->tun_pgrp, SIGIO); 525 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 526 psignal(p, SIGIO); 527 } 528 selnotify(&tp->tun_rsel, 0); 529 simple_unlock(&tp->tun_lock); 530 return (0); 531 } 532 533 /* 534 * the cdevsw interface is now pretty minimal. 535 */ 536 int 537 tunioctl(dev, cmd, data, flag, p) 538 dev_t dev; 539 u_long cmd; 540 caddr_t data; 541 int flag; 542 struct proc *p; 543 { 544 int s; 545 struct tun_softc *tp; 546 pid_t pgid; 547 int error; 548 549 tp = tun_find_unit(dev); 550 551 /* interface was "destroyed" already */ 552 if (tp == NULL) 553 return (ENXIO); 554 555 switch (cmd) { 556 case TUNSDEBUG: 557 tundebug = *(int *)data; 558 break; 559 560 case TUNGDEBUG: 561 *(int *)data = tundebug; 562 break; 563 564 case TUNSIFMODE: 565 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 566 case IFF_POINTOPOINT: 567 case IFF_BROADCAST: 568 s = splnet(); 569 if (tp->tun_if.if_flags & IFF_UP) { 570 splx(s); 571 simple_unlock(&tp->tun_lock); 572 return (EBUSY); 573 } 574 tp->tun_if.if_flags &= 575 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 576 tp->tun_if.if_flags |= *(int *)data; 577 splx(s); 578 break; 579 default: 580 simple_unlock(&tp->tun_lock); 581 return (EINVAL); 582 } 583 break; 584 585 case TUNSLMODE: 586 if (*(int *)data) 587 tp->tun_flags |= TUN_PREPADDR; 588 else 589 tp->tun_flags &= ~TUN_PREPADDR; 590 break; 591 592 case FIONBIO: 593 if (*(int *)data) 594 tp->tun_flags |= TUN_NBIO; 595 else 596 tp->tun_flags &= ~TUN_NBIO; 597 break; 598 599 case FIOASYNC: 600 if (*(int *)data) 601 tp->tun_flags |= TUN_ASYNC; 602 else 603 tp->tun_flags &= ~TUN_ASYNC; 604 break; 605 606 case FIONREAD: 607 s = splnet(); 608 if (tp->tun_if.if_snd.ifq_head) 609 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 610 else 611 *(int *)data = 0; 612 splx(s); 613 break; 614 615 case TIOCSPGRP: 616 pgid = *(int *)data; 617 if (pgid != 0) { 618 error = pgid_in_session(p, pgid); 619 if (error != 0) 620 return error; 621 } 622 tp->tun_pgrp = pgid; 623 break; 624 625 case TIOCGPGRP: 626 *(int *)data = tp->tun_pgrp; 627 break; 628 629 default: 630 simple_unlock(&tp->tun_lock); 631 return (ENOTTY); 632 } 633 simple_unlock(&tp->tun_lock); 634 return (0); 635 } 636 637 /* 638 * The cdevsw read interface - reads a packet at a time, or at 639 * least as much of a packet as can be read. 640 */ 641 int 642 tunread(dev, uio, ioflag) 643 dev_t dev; 644 struct uio *uio; 645 int ioflag; 646 { 647 struct tun_softc *tp; 648 struct ifnet *ifp; 649 struct mbuf *m, *m0; 650 int error=0, len, s, index; 651 652 tp = tun_find_unit(dev); 653 654 /* interface was "destroyed" already */ 655 if (tp == NULL) 656 return (ENXIO); 657 658 index = tp->tun_if.if_index; 659 ifp = &tp->tun_if; 660 661 TUNDEBUG ("%s: read\n", ifp->if_xname); 662 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 663 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 664 simple_unlock(&tp->tun_lock); 665 return EHOSTDOWN; 666 } 667 668 tp->tun_flags &= ~TUN_RWAIT; 669 670 s = splnet(); 671 do { 672 IFQ_DEQUEUE(&ifp->if_snd, m0); 673 if (m0 == 0) { 674 if (tp->tun_flags & TUN_NBIO) { 675 splx(s); 676 simple_unlock(&tp->tun_lock); 677 return (EWOULDBLOCK); 678 } 679 tp->tun_flags |= TUN_RWAIT; 680 simple_unlock(&tp->tun_lock); 681 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 682 splx(s); 683 return (EINTR); 684 } else { 685 /* 686 * Maybe the interface was destroyed while 687 * we were sleeping, so let's ensure that 688 * we're looking at the same (valid) tun 689 * interface before looping. 690 */ 691 tp = tun_find_unit(dev); 692 if (tp == NULL || 693 tp->tun_if.if_index != index) { 694 splx(s); 695 if (tp) 696 simple_unlock(&tp->tun_lock); 697 return (ENXIO); 698 } 699 } 700 } 701 } while (m0 == 0); 702 splx(s); 703 704 while (m0 && uio->uio_resid > 0 && error == 0) { 705 len = min(uio->uio_resid, m0->m_len); 706 if (len != 0) 707 error = uiomove(mtod(m0, caddr_t), len, uio); 708 MFREE(m0, m); 709 m0 = m; 710 } 711 712 if (m0) { 713 TUNDEBUG("Dropping mbuf\n"); 714 m_freem(m0); 715 } 716 if (error) 717 ifp->if_ierrors++; 718 simple_unlock(&tp->tun_lock); 719 return (error); 720 } 721 722 /* 723 * the cdevsw write interface - an atomic write is a packet - or else! 724 */ 725 int 726 tunwrite(dev, uio, ioflag) 727 dev_t dev; 728 struct uio *uio; 729 int ioflag; 730 { 731 struct tun_softc *tp; 732 struct ifnet *ifp; 733 struct mbuf *top, **mp, *m; 734 struct ifqueue *ifq; 735 struct sockaddr dst; 736 int isr, error=0, s, tlen, mlen; 737 738 tp = tun_find_unit(dev); 739 740 /* interface was "destroyed" already */ 741 if (tp == NULL) 742 return (ENXIO); 743 744 ifp = &tp->tun_if; 745 746 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 747 748 if (tp->tun_flags & TUN_PREPADDR) { 749 if (uio->uio_resid < sizeof(dst)) { 750 simple_unlock(&tp->tun_lock); 751 return (EIO); 752 } 753 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 754 if (dst.sa_len > sizeof(dst)) { 755 /* Duh.. */ 756 char discard; 757 int n = dst.sa_len - sizeof(dst); 758 while (n--) 759 if ((error = uiomove(&discard, 1, uio)) != 0) { 760 simple_unlock(&tp->tun_lock); 761 return (error); 762 } 763 } 764 } else { 765 #ifdef INET 766 dst.sa_family = AF_INET; 767 #endif 768 } 769 770 if (uio->uio_resid > TUNMTU) { 771 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 772 (unsigned long)uio->uio_resid); 773 simple_unlock(&tp->tun_lock); 774 return (EIO); 775 } 776 777 switch (dst.sa_family) { 778 #ifdef INET 779 case AF_INET: 780 ifq = &ipintrq; 781 isr = NETISR_IP; 782 break; 783 #endif 784 default: 785 simple_unlock(&tp->tun_lock); 786 return (EAFNOSUPPORT); 787 } 788 789 tlen = uio->uio_resid; 790 791 /* get a header mbuf */ 792 MGETHDR(m, M_DONTWAIT, MT_DATA); 793 if (m == NULL) { 794 simple_unlock(&tp->tun_lock); 795 return (ENOBUFS); 796 } 797 mlen = MHLEN; 798 799 top = 0; 800 mp = ⊤ 801 while (error == 0 && uio->uio_resid > 0) { 802 m->m_len = min(mlen, uio->uio_resid); 803 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 804 *mp = m; 805 mp = &m->m_next; 806 if (uio->uio_resid > 0) { 807 MGET (m, M_DONTWAIT, MT_DATA); 808 if (m == 0) { 809 error = ENOBUFS; 810 break; 811 } 812 mlen = MLEN; 813 } 814 } 815 if (error) { 816 if (top) 817 m_freem (top); 818 ifp->if_ierrors++; 819 simple_unlock(&tp->tun_lock); 820 return (error); 821 } 822 823 top->m_pkthdr.len = tlen; 824 top->m_pkthdr.rcvif = ifp; 825 826 #if NBPFILTER > 0 827 if (ifp->if_bpf) { 828 /* 829 * We need to prepend the address family as 830 * a four byte field. Cons up a dummy header 831 * to pacify bpf. This is safe because bpf 832 * will only read from the mbuf (i.e., it won't 833 * try to free it or keep a pointer to it). 834 */ 835 struct mbuf m; 836 u_int32_t af = AF_INET; 837 838 m.m_flags = 0; 839 m.m_next = top; 840 m.m_len = sizeof(af); 841 m.m_data = (char *)⁡ 842 843 bpf_mtap(ifp->if_bpf, &m); 844 } 845 #endif 846 847 s = splnet(); 848 if (IF_QFULL(ifq)) { 849 IF_DROP(ifq); 850 splx(s); 851 ifp->if_collisions++; 852 m_freem(top); 853 simple_unlock(&tp->tun_lock); 854 return (ENOBUFS); 855 } 856 IF_ENQUEUE(ifq, top); 857 splx(s); 858 ifp->if_ipackets++; 859 ifp->if_ibytes += tlen; 860 schednetisr(isr); 861 simple_unlock(&tp->tun_lock); 862 return (error); 863 } 864 865 #ifdef ALTQ 866 /* 867 * Start packet transmission on the interface. 868 * when the interface queue is rate-limited by ALTQ or TBR, 869 * if_start is needed to drain packets from the queue in order 870 * to notify readers when outgoing packets become ready. 871 */ 872 static void 873 tunstart(ifp) 874 struct ifnet *ifp; 875 { 876 struct tun_softc *tp = ifp->if_softc; 877 struct mbuf *m; 878 struct proc *p; 879 880 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 881 return; 882 883 IFQ_POLL(&ifp->if_snd, m); 884 if (m != NULL) { 885 if (tp->tun_flags & TUN_RWAIT) { 886 tp->tun_flags &= ~TUN_RWAIT; 887 wakeup((caddr_t)tp); 888 } 889 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 890 if (tp->tun_pgrp > 0) 891 gsignal(tp->tun_pgrp, SIGIO); 892 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 893 psignal(p, SIGIO); 894 } 895 selwakeup(&tp->tun_rsel); 896 } 897 } 898 #endif /* ALTQ */ 899 /* 900 * tunpoll - the poll interface, this is only useful on reads 901 * really. The write detect always returns true, write never blocks 902 * anyway, it either accepts the packet or drops it. 903 */ 904 int 905 tunpoll(dev, events, p) 906 dev_t dev; 907 int events; 908 struct proc *p; 909 { 910 struct tun_softc *tp; 911 struct ifnet *ifp; 912 int s, revents = 0; 913 914 tp = tun_find_unit(dev); 915 916 /* interface was "destroyed" already */ 917 if (tp == NULL) 918 return (0); 919 920 ifp = &tp->tun_if; 921 922 s = splnet(); 923 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 924 925 if (events & (POLLIN | POLLRDNORM)) { 926 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 927 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 928 ifp->if_snd.ifq_len); 929 revents |= events & (POLLIN | POLLRDNORM); 930 } else { 931 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 932 selrecord(p, &tp->tun_rsel); 933 } 934 } 935 936 if (events & (POLLOUT | POLLWRNORM)) 937 revents |= events & (POLLOUT | POLLWRNORM); 938 939 splx(s); 940 simple_unlock(&tp->tun_lock); 941 return (revents); 942 } 943 944 static void 945 filt_tunrdetach(struct knote *kn) 946 { 947 struct tun_softc *tp = kn->kn_hook; 948 int s; 949 950 s = splnet(); 951 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 952 splx(s); 953 } 954 955 static int 956 filt_tunread(struct knote *kn, long hint) 957 { 958 struct tun_softc *tp = kn->kn_hook; 959 struct ifnet *ifp = &tp->tun_if; 960 struct mbuf *m; 961 int s; 962 963 s = splnet(); 964 IF_POLL(&ifp->if_snd, m); 965 if (m == NULL) { 966 splx(s); 967 return (0); 968 } 969 970 for (kn->kn_data = 0; m != NULL; m = m->m_next) 971 kn->kn_data += m->m_len; 972 973 splx(s); 974 return (1); 975 } 976 977 static const struct filterops tunread_filtops = 978 { 1, NULL, filt_tunrdetach, filt_tunread }; 979 980 static const struct filterops tun_seltrue_filtops = 981 { 1, NULL, filt_tunrdetach, filt_seltrue }; 982 983 int 984 tunkqfilter(dev_t dev, struct knote *kn) 985 { 986 struct tun_softc *tp = tun_find_unit(dev); 987 struct klist *klist; 988 int s; 989 990 switch (kn->kn_filter) { 991 case EVFILT_READ: 992 klist = &tp->tun_rsel.sel_klist; 993 kn->kn_fop = &tunread_filtops; 994 break; 995 996 case EVFILT_WRITE: 997 klist = &tp->tun_rsel.sel_klist; 998 kn->kn_fop = &tun_seltrue_filtops; 999 break; 1000 1001 default: 1002 return (1); 1003 } 1004 1005 kn->kn_hook = tp; 1006 1007 s = splnet(); 1008 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1009 splx(s); 1010 1011 return (0); 1012 } 1013
Indexes created Wed Sep 24 05:09:52 GMT 2025