if_tun.c revision 1.58
1 /* $NetBSD: if_tun.c,v 1.58 2002/12/25 08:40:20 jdolecek 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 1.58 2002/12/25 08:40:20 jdolecek 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_next = m0; 476 m.m_len = sizeof(af); 477 m.m_data = (char *)⁡ 478 479 bpf_mtap(ifp->if_bpf, &m); 480 } 481 #endif 482 483 switch(dst->sa_family) { 484 #ifdef INET 485 case AF_INET: 486 if (tp->tun_flags & TUN_PREPADDR) { 487 /* Simple link-layer header */ 488 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 489 if (m0 == NULL) { 490 IF_DROP(&ifp->if_snd); 491 simple_unlock(&tp->tun_lock); 492 return (ENOBUFS); 493 } 494 bcopy(dst, mtod(m0, char *), dst->sa_len); 495 } 496 /* FALLTHROUGH */ 497 case AF_UNSPEC: 498 s = splnet(); 499 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 500 if (error) { 501 splx(s); 502 ifp->if_collisions++; 503 return (error); 504 } 505 mlen = m0->m_pkthdr.len; 506 splx(s); 507 ifp->if_opackets++; 508 ifp->if_obytes += mlen; 509 break; 510 #endif 511 default: 512 m_freem(m0); 513 simple_unlock(&tp->tun_lock); 514 return (EAFNOSUPPORT); 515 } 516 517 if (tp->tun_flags & TUN_RWAIT) { 518 tp->tun_flags &= ~TUN_RWAIT; 519 wakeup((caddr_t)tp); 520 } 521 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 522 if (tp->tun_pgrp > 0) 523 gsignal(tp->tun_pgrp, SIGIO); 524 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 525 psignal(p, SIGIO); 526 } 527 selnotify(&tp->tun_rsel, 0); 528 simple_unlock(&tp->tun_lock); 529 return (0); 530 } 531 532 /* 533 * the cdevsw interface is now pretty minimal. 534 */ 535 int 536 tunioctl(dev, cmd, data, flag, p) 537 dev_t dev; 538 u_long cmd; 539 caddr_t data; 540 int flag; 541 struct proc *p; 542 { 543 int s; 544 struct tun_softc *tp; 545 546 tp = tun_find_unit(dev); 547 548 /* interface was "destroyed" already */ 549 if (tp == NULL) 550 return (ENXIO); 551 552 switch (cmd) { 553 case TUNSDEBUG: 554 tundebug = *(int *)data; 555 break; 556 557 case TUNGDEBUG: 558 *(int *)data = tundebug; 559 break; 560 561 case TUNSIFMODE: 562 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 563 case IFF_POINTOPOINT: 564 case IFF_BROADCAST: 565 s = splnet(); 566 if (tp->tun_if.if_flags & IFF_UP) { 567 splx(s); 568 simple_unlock(&tp->tun_lock); 569 return (EBUSY); 570 } 571 tp->tun_if.if_flags &= 572 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 573 tp->tun_if.if_flags |= *(int *)data; 574 splx(s); 575 break; 576 default: 577 simple_unlock(&tp->tun_lock); 578 return (EINVAL); 579 } 580 break; 581 582 case TUNSLMODE: 583 if (*(int *)data) 584 tp->tun_flags |= TUN_PREPADDR; 585 else 586 tp->tun_flags &= ~TUN_PREPADDR; 587 break; 588 589 case FIONBIO: 590 if (*(int *)data) 591 tp->tun_flags |= TUN_NBIO; 592 else 593 tp->tun_flags &= ~TUN_NBIO; 594 break; 595 596 case FIOASYNC: 597 if (*(int *)data) 598 tp->tun_flags |= TUN_ASYNC; 599 else 600 tp->tun_flags &= ~TUN_ASYNC; 601 break; 602 603 case FIONREAD: 604 s = splnet(); 605 if (tp->tun_if.if_snd.ifq_head) 606 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 607 else 608 *(int *)data = 0; 609 splx(s); 610 break; 611 612 case TIOCSPGRP: 613 tp->tun_pgrp = *(int *)data; 614 break; 615 616 case TIOCGPGRP: 617 *(int *)data = tp->tun_pgrp; 618 break; 619 620 default: 621 simple_unlock(&tp->tun_lock); 622 return (ENOTTY); 623 } 624 simple_unlock(&tp->tun_lock); 625 return (0); 626 } 627 628 /* 629 * The cdevsw read interface - reads a packet at a time, or at 630 * least as much of a packet as can be read. 631 */ 632 int 633 tunread(dev, uio, ioflag) 634 dev_t dev; 635 struct uio *uio; 636 int ioflag; 637 { 638 struct tun_softc *tp; 639 struct ifnet *ifp; 640 struct mbuf *m, *m0; 641 int error=0, len, s, index; 642 643 tp = tun_find_unit(dev); 644 645 /* interface was "destroyed" already */ 646 if (tp == NULL) 647 return (ENXIO); 648 649 index = tp->tun_if.if_index; 650 ifp = &tp->tun_if; 651 652 TUNDEBUG ("%s: read\n", ifp->if_xname); 653 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 654 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 655 simple_unlock(&tp->tun_lock); 656 return EHOSTDOWN; 657 } 658 659 tp->tun_flags &= ~TUN_RWAIT; 660 661 s = splnet(); 662 do { 663 IFQ_DEQUEUE(&ifp->if_snd, m0); 664 if (m0 == 0) { 665 if (tp->tun_flags & TUN_NBIO) { 666 splx(s); 667 simple_unlock(&tp->tun_lock); 668 return (EWOULDBLOCK); 669 } 670 tp->tun_flags |= TUN_RWAIT; 671 simple_unlock(&tp->tun_lock); 672 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 673 splx(s); 674 return (EINTR); 675 } else { 676 /* 677 * Maybe the interface was destroyed while 678 * we were sleeping, so let's ensure that 679 * we're looking at the same (valid) tun 680 * interface before looping. 681 */ 682 tp = tun_find_unit(dev); 683 if (tp == NULL || 684 tp->tun_if.if_index != index) { 685 splx(s); 686 if (tp) 687 simple_unlock(&tp->tun_lock); 688 return (ENXIO); 689 } 690 } 691 } 692 } while (m0 == 0); 693 splx(s); 694 695 while (m0 && uio->uio_resid > 0 && error == 0) { 696 len = min(uio->uio_resid, m0->m_len); 697 if (len != 0) 698 error = uiomove(mtod(m0, caddr_t), len, uio); 699 MFREE(m0, m); 700 m0 = m; 701 } 702 703 if (m0) { 704 TUNDEBUG("Dropping mbuf\n"); 705 m_freem(m0); 706 } 707 if (error) 708 ifp->if_ierrors++; 709 simple_unlock(&tp->tun_lock); 710 return (error); 711 } 712 713 /* 714 * the cdevsw write interface - an atomic write is a packet - or else! 715 */ 716 int 717 tunwrite(dev, uio, ioflag) 718 dev_t dev; 719 struct uio *uio; 720 int ioflag; 721 { 722 struct tun_softc *tp; 723 struct ifnet *ifp; 724 struct mbuf *top, **mp, *m; 725 struct ifqueue *ifq; 726 struct sockaddr dst; 727 int isr, error=0, s, tlen, mlen; 728 729 tp = tun_find_unit(dev); 730 731 /* interface was "destroyed" already */ 732 if (tp == NULL) 733 return (ENXIO); 734 735 ifp = &tp->tun_if; 736 737 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 738 739 if (tp->tun_flags & TUN_PREPADDR) { 740 if (uio->uio_resid < sizeof(dst)) { 741 simple_unlock(&tp->tun_lock); 742 return (EIO); 743 } 744 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 745 if (dst.sa_len > sizeof(dst)) { 746 /* Duh.. */ 747 char discard; 748 int n = dst.sa_len - sizeof(dst); 749 while (n--) 750 if ((error = uiomove(&discard, 1, uio)) != 0) { 751 simple_unlock(&tp->tun_lock); 752 return (error); 753 } 754 } 755 } else { 756 #ifdef INET 757 dst.sa_family = AF_INET; 758 #endif 759 } 760 761 if (uio->uio_resid > TUNMTU) { 762 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 763 (unsigned long)uio->uio_resid); 764 simple_unlock(&tp->tun_lock); 765 return (EIO); 766 } 767 768 switch (dst.sa_family) { 769 #ifdef INET 770 case AF_INET: 771 ifq = &ipintrq; 772 isr = NETISR_IP; 773 break; 774 #endif 775 default: 776 simple_unlock(&tp->tun_lock); 777 return (EAFNOSUPPORT); 778 } 779 780 tlen = uio->uio_resid; 781 782 /* get a header mbuf */ 783 MGETHDR(m, M_DONTWAIT, MT_DATA); 784 if (m == NULL) { 785 simple_unlock(&tp->tun_lock); 786 return (ENOBUFS); 787 } 788 mlen = MHLEN; 789 790 top = 0; 791 mp = ⊤ 792 while (error == 0 && uio->uio_resid > 0) { 793 m->m_len = min(mlen, uio->uio_resid); 794 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 795 *mp = m; 796 mp = &m->m_next; 797 if (uio->uio_resid > 0) { 798 MGET (m, M_DONTWAIT, MT_DATA); 799 if (m == 0) { 800 error = ENOBUFS; 801 break; 802 } 803 mlen = MLEN; 804 } 805 } 806 if (error) { 807 if (top) 808 m_freem (top); 809 ifp->if_ierrors++; 810 simple_unlock(&tp->tun_lock); 811 return (error); 812 } 813 814 top->m_pkthdr.len = tlen; 815 top->m_pkthdr.rcvif = ifp; 816 817 #if NBPFILTER > 0 818 if (ifp->if_bpf) { 819 /* 820 * We need to prepend the address family as 821 * a four byte field. Cons up a dummy header 822 * to pacify bpf. This is safe because bpf 823 * will only read from the mbuf (i.e., it won't 824 * try to free it or keep a pointer to it). 825 */ 826 struct mbuf m; 827 u_int32_t af = AF_INET; 828 829 m.m_next = top; 830 m.m_len = sizeof(af); 831 m.m_data = (char *)⁡ 832 833 bpf_mtap(ifp->if_bpf, &m); 834 } 835 #endif 836 837 s = splnet(); 838 if (IF_QFULL(ifq)) { 839 IF_DROP(ifq); 840 splx(s); 841 ifp->if_collisions++; 842 m_freem(top); 843 simple_unlock(&tp->tun_lock); 844 return (ENOBUFS); 845 } 846 IF_ENQUEUE(ifq, top); 847 splx(s); 848 ifp->if_ipackets++; 849 ifp->if_ibytes += tlen; 850 schednetisr(isr); 851 simple_unlock(&tp->tun_lock); 852 return (error); 853 } 854 855 #ifdef ALTQ 856 /* 857 * Start packet transmission on the interface. 858 * when the interface queue is rate-limited by ALTQ or TBR, 859 * if_start is needed to drain packets from the queue in order 860 * to notify readers when outgoing packets become ready. 861 */ 862 static void 863 tunstart(ifp) 864 struct ifnet *ifp; 865 { 866 struct tun_softc *tp = ifp->if_softc; 867 struct mbuf *m; 868 struct proc *p; 869 870 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 871 return; 872 873 IFQ_POLL(&ifp->if_snd, m); 874 if (m != NULL) { 875 if (tp->tun_flags & TUN_RWAIT) { 876 tp->tun_flags &= ~TUN_RWAIT; 877 wakeup((caddr_t)tp); 878 } 879 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 880 if (tp->tun_pgrp > 0) 881 gsignal(tp->tun_pgrp, SIGIO); 882 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 883 psignal(p, SIGIO); 884 } 885 selwakeup(&tp->tun_rsel); 886 } 887 } 888 #endif /* ALTQ */ 889 /* 890 * tunpoll - the poll interface, this is only useful on reads 891 * really. The write detect always returns true, write never blocks 892 * anyway, it either accepts the packet or drops it. 893 */ 894 int 895 tunpoll(dev, events, p) 896 dev_t dev; 897 int events; 898 struct proc *p; 899 { 900 struct tun_softc *tp; 901 struct ifnet *ifp; 902 int s, revents = 0; 903 904 tp = tun_find_unit(dev); 905 906 /* interface was "destroyed" already */ 907 if (tp == NULL) 908 return (0); 909 910 ifp = &tp->tun_if; 911 912 s = splnet(); 913 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 914 915 if (events & (POLLIN | POLLRDNORM)) { 916 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 917 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 918 ifp->if_snd.ifq_len); 919 revents |= events & (POLLIN | POLLRDNORM); 920 } else { 921 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 922 selrecord(p, &tp->tun_rsel); 923 } 924 } 925 926 if (events & (POLLOUT | POLLWRNORM)) 927 revents |= events & (POLLOUT | POLLWRNORM); 928 929 splx(s); 930 simple_unlock(&tp->tun_lock); 931 return (revents); 932 } 933 934 static void 935 filt_tunrdetach(struct knote *kn) 936 { 937 struct tun_softc *tp = kn->kn_hook; 938 int s; 939 940 s = splnet(); 941 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 942 splx(s); 943 } 944 945 static int 946 filt_tunread(struct knote *kn, long hint) 947 { 948 struct tun_softc *tp = kn->kn_hook; 949 struct ifnet *ifp = &tp->tun_if; 950 struct mbuf *m; 951 int s; 952 953 s = splnet(); 954 IF_POLL(&ifp->if_snd, m); 955 if (m == NULL) { 956 splx(s); 957 return (0); 958 } 959 960 for (kn->kn_data = 0; m != NULL; m = m->m_next) 961 kn->kn_data += m->m_len; 962 963 splx(s); 964 return (1); 965 } 966 967 static const struct filterops tunread_filtops = 968 { 1, NULL, filt_tunrdetach, filt_tunread }; 969 970 static const struct filterops tun_seltrue_filtops = 971 { 1, NULL, filt_tunrdetach, filt_seltrue }; 972 973 int 974 tunkqfilter(dev_t dev, struct knote *kn) 975 { 976 struct tun_softc *tp = tun_find_unit(dev); 977 struct klist *klist; 978 int s; 979 980 switch (kn->kn_filter) { 981 case EVFILT_READ: 982 klist = &tp->tun_rsel.sel_klist; 983 kn->kn_fop = &tunread_filtops; 984 break; 985 986 case EVFILT_WRITE: 987 klist = &tp->tun_rsel.sel_klist; 988 kn->kn_fop = &tun_seltrue_filtops; 989 break; 990 991 default: 992 return (1); 993 } 994 995 kn->kn_hook = tp; 996 997 s = splnet(); 998 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 999 splx(s); 1000 1001 return (0); 1002 } 1003
Indexes created Wed Sep 24 05:09:52 GMT 2025