if_tun.c revision 1.76
1 /* $NetBSD: if_tun.c,v 1.76 2005/01/24 21:25:09 matt 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 1.76 2005/01/24 21:25:09 matt Exp $"); 19 20 #include "opt_inet.h" 21 #include "opt_ns.h" 22 23 #include <sys/param.h> 24 #include <sys/proc.h> 25 #include <sys/systm.h> 26 #include <sys/mbuf.h> 27 #include <sys/buf.h> 28 #include <sys/protosw.h> 29 #include <sys/socket.h> 30 #include <sys/ioctl.h> 31 #include <sys/errno.h> 32 #include <sys/syslog.h> 33 #include <sys/select.h> 34 #include <sys/poll.h> 35 #include <sys/file.h> 36 #include <sys/signalvar.h> 37 #include <sys/conf.h> 38 39 #include <machine/cpu.h> 40 41 #include <net/if.h> 42 #include <net/if_types.h> 43 #include <net/netisr.h> 44 #include <net/route.h> 45 46 47 #ifdef INET 48 #include <netinet/in.h> 49 #include <netinet/in_systm.h> 50 #include <netinet/in_var.h> 51 #include <netinet/ip.h> 52 #include <netinet/if_inarp.h> 53 #endif 54 55 #ifdef NS 56 #include <netns/ns.h> 57 #include <netns/ns_if.h> 58 #endif 59 60 #include "bpfilter.h" 61 #if NBPFILTER > 0 62 #include <sys/time.h> 63 #include <net/bpf.h> 64 #endif 65 66 #include <net/if_tun.h> 67 68 #define TUNDEBUG if (tundebug) printf 69 int tundebug = 0; 70 71 extern int ifqmaxlen; 72 void tunattach __P((int)); 73 LIST_HEAD(, tun_softc) tun_softc_list; 74 LIST_HEAD(, tun_softc) tunz_softc_list; 75 static struct simplelock tun_softc_lock; 76 77 int tun_ioctl __P((struct ifnet *, u_long, caddr_t)); 78 int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 79 struct rtentry *rt)); 80 int tun_clone_create __P((struct if_clone *, int)); 81 int tun_clone_destroy __P((struct ifnet *)); 82 83 struct if_clone tun_cloner = 84 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 85 86 static void tunattach0 __P((struct tun_softc *)); 87 static void tuninit __P((struct tun_softc *)); 88 #ifdef ALTQ 89 static void tunstart __P((struct ifnet *)); 90 #endif 91 static struct tun_softc *tun_find_unit __P((dev_t)); 92 static struct tun_softc *tun_find_zunit __P((int)); 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 LIST_INIT(&tunz_softc_list); 115 if_clone_attach(&tun_cloner); 116 } 117 118 /* 119 * Find driver instance from dev_t. 120 * Call at splnet(). 121 * Returns with tp locked (if found). 122 */ 123 static struct tun_softc * 124 tun_find_unit(dev) 125 dev_t dev; 126 { 127 struct tun_softc *tp; 128 int unit = minor(dev); 129 130 simple_lock(&tun_softc_lock); 131 LIST_FOREACH(tp, &tun_softc_list, tun_list) 132 if (unit == tp->tun_unit) 133 break; 134 if (tp) 135 simple_lock(&tp->tun_lock); 136 simple_unlock(&tun_softc_lock); 137 138 return (tp); 139 } 140 141 /* 142 * Find zombie driver instance by unit number. 143 * Call at splnet(). 144 * Remove tp from list and return it unlocked (if found). 145 */ 146 static struct tun_softc * 147 tun_find_zunit(unit) 148 int unit; 149 { 150 struct tun_softc *tp; 151 152 simple_lock(&tun_softc_lock); 153 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 154 if (unit == tp->tun_unit) 155 break; 156 if (tp) 157 LIST_REMOVE(tp, tun_list); 158 simple_unlock(&tun_softc_lock); 159 #ifdef DIAGNOSTIC 160 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 161 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 162 #endif 163 164 return (tp); 165 } 166 167 int 168 tun_clone_create(ifc, unit) 169 struct if_clone *ifc; 170 int unit; 171 { 172 struct tun_softc *tp; 173 174 if ((tp = tun_find_zunit(unit)) == NULL) { 175 /* Allocate a new instance */ 176 tp = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 177 (void)memset(tp, 0, sizeof(struct tun_softc)); 178 179 tp->tun_unit = unit; 180 simple_lock_init(&tp->tun_lock); 181 } else { 182 /* Revive tunnel instance; clear ifp part */ 183 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 184 } 185 186 (void)snprintf(tp->tun_if.if_xname, sizeof(tp->tun_if.if_xname), 187 "%s%d", ifc->ifc_name, unit); 188 tunattach0(tp); 189 tp->tun_flags |= TUN_INITED; 190 191 simple_lock(&tun_softc_lock); 192 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 193 simple_unlock(&tun_softc_lock); 194 195 return (0); 196 } 197 198 void 199 tunattach0(tp) 200 struct tun_softc *tp; 201 { 202 struct ifnet *ifp; 203 204 ifp = &tp->tun_if; 205 ifp->if_softc = tp; 206 ifp->if_mtu = TUNMTU; 207 ifp->if_ioctl = tun_ioctl; 208 ifp->if_output = tun_output; 209 #ifdef ALTQ 210 ifp->if_start = tunstart; 211 #endif 212 ifp->if_flags = IFF_POINTOPOINT; 213 ifp->if_type = IFT_TUNNEL; 214 ifp->if_snd.ifq_maxlen = ifqmaxlen; 215 ifp->if_collisions = 0; 216 ifp->if_ierrors = 0; 217 ifp->if_oerrors = 0; 218 ifp->if_ipackets = 0; 219 ifp->if_opackets = 0; 220 ifp->if_ibytes = 0; 221 ifp->if_obytes = 0; 222 ifp->if_dlt = DLT_NULL; 223 IFQ_SET_READY(&ifp->if_snd); 224 if_attach(ifp); 225 if_alloc_sadl(ifp); 226 #if NBPFILTER > 0 227 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 228 #endif 229 } 230 231 int 232 tun_clone_destroy(ifp) 233 struct ifnet *ifp; 234 { 235 struct tun_softc *tp = (void *)ifp; 236 int s, zombie = 0; 237 238 s = splnet(); 239 simple_lock(&tun_softc_lock); 240 simple_lock(&tp->tun_lock); 241 LIST_REMOVE(tp, tun_list); 242 if (tp->tun_flags & TUN_OPEN) { 243 /* Hang on to storage until last close */ 244 zombie = 1; 245 tp->tun_flags &= ~TUN_INITED; 246 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 247 } 248 simple_unlock(&tun_softc_lock); 249 250 IF_PURGE(&ifp->if_snd); 251 ifp->if_flags &= ~IFF_RUNNING; 252 253 if (tp->tun_flags & TUN_RWAIT) { 254 tp->tun_flags &= ~TUN_RWAIT; 255 wakeup((caddr_t)tp); 256 } 257 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 258 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 259 260 selwakeup(&tp->tun_rsel); 261 262 simple_unlock(&tp->tun_lock); 263 splx(s); 264 265 #if NBPFILTER > 0 266 bpfdetach(ifp); 267 #endif 268 if_detach(ifp); 269 270 if (!zombie) 271 free(tp, M_DEVBUF); 272 273 return (0); 274 } 275 276 /* 277 * tunnel open - must be superuser & the device must be 278 * configured in 279 */ 280 int 281 tunopen(dev, flag, mode, p) 282 dev_t dev; 283 int flag, mode; 284 struct proc *p; 285 { 286 struct ifnet *ifp; 287 struct tun_softc *tp; 288 int s, error; 289 290 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 291 return (error); 292 293 s = splnet(); 294 tp = tun_find_unit(dev); 295 296 if (tp == NULL) { 297 (void)tun_clone_create(&tun_cloner, minor(dev)); 298 tp = tun_find_unit(dev); 299 if (tp == NULL) { 300 error = ENXIO; 301 goto out_nolock; 302 } 303 } 304 305 if (tp->tun_flags & TUN_OPEN) { 306 error = EBUSY; 307 goto out; 308 } 309 310 ifp = &tp->tun_if; 311 tp->tun_flags |= TUN_OPEN; 312 TUNDEBUG("%s: open\n", ifp->if_xname); 313 out: 314 simple_unlock(&tp->tun_lock); 315 out_nolock: 316 splx(s); 317 return (error); 318 } 319 320 /* 321 * tunclose - close the device - mark i/f down & delete 322 * routing info 323 */ 324 int 325 tunclose(dev, flag, mode, p) 326 dev_t dev; 327 int flag; 328 int mode; 329 struct proc *p; 330 { 331 int s; 332 struct tun_softc *tp; 333 struct ifnet *ifp; 334 335 s = splnet(); 336 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 337 /* interface was "destroyed" before the close */ 338 free(tp, M_DEVBUF); 339 goto out_nolock; 340 } 341 342 if ((tp = tun_find_unit(dev)) == NULL) 343 goto out_nolock; 344 345 ifp = &tp->tun_if; 346 347 tp->tun_flags &= ~TUN_OPEN; 348 349 /* 350 * junk all pending output 351 */ 352 IFQ_PURGE(&ifp->if_snd); 353 354 if (ifp->if_flags & IFF_UP) { 355 if_down(ifp); 356 if (ifp->if_flags & IFF_RUNNING) { 357 /* find internet addresses and delete routes */ 358 struct ifaddr *ifa; 359 IFADDR_FOREACH(ifa, ifp) { 360 #ifdef INET 361 if (ifa->ifa_addr->sa_family == AF_INET) { 362 rtinit(ifa, (int)RTM_DELETE, 363 tp->tun_flags & TUN_DSTADDR 364 ? RTF_HOST 365 : 0); 366 } 367 #endif 368 } 369 } 370 } 371 tp->tun_pgid = 0; 372 selnotify(&tp->tun_rsel, 0); 373 374 TUNDEBUG ("%s: closed\n", ifp->if_xname); 375 simple_unlock(&tp->tun_lock); 376 out_nolock: 377 splx(s); 378 return (0); 379 } 380 381 /* 382 * Call at splnet() with tp locked. 383 */ 384 static void 385 tuninit(tp) 386 struct tun_softc *tp; 387 { 388 struct ifnet *ifp = &tp->tun_if; 389 struct ifaddr *ifa; 390 391 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 392 393 ifp->if_flags |= IFF_UP | IFF_RUNNING; 394 395 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 396 IFADDR_FOREACH(ifa, ifp) { 397 #ifdef INET 398 if (ifa->ifa_addr->sa_family == AF_INET) { 399 struct sockaddr_in *sin; 400 401 sin = satosin(ifa->ifa_addr); 402 if (sin && sin->sin_addr.s_addr) 403 tp->tun_flags |= TUN_IASET; 404 405 if (ifp->if_flags & IFF_POINTOPOINT) { 406 sin = satosin(ifa->ifa_dstaddr); 407 if (sin && sin->sin_addr.s_addr) 408 tp->tun_flags |= TUN_DSTADDR; 409 } 410 } 411 #endif 412 } 413 414 return; 415 } 416 417 /* 418 * Process an ioctl request. 419 */ 420 int 421 tun_ioctl(ifp, cmd, data) 422 struct ifnet *ifp; 423 u_long cmd; 424 caddr_t data; 425 { 426 int error = 0, s; 427 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 428 429 s = splnet(); 430 simple_lock(&tp->tun_lock); 431 432 switch (cmd) { 433 case SIOCSIFADDR: 434 tuninit(tp); 435 TUNDEBUG("%s: address set\n", ifp->if_xname); 436 break; 437 case SIOCSIFDSTADDR: 438 tuninit(tp); 439 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 440 break; 441 case SIOCSIFBRDADDR: 442 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 443 break; 444 case SIOCSIFMTU: { 445 struct ifreq *ifr = (struct ifreq *) data; 446 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 447 error = EINVAL; 448 break; 449 } 450 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 451 ifp->if_mtu = ifr->ifr_mtu; 452 break; 453 } 454 case SIOCADDMULTI: 455 case SIOCDELMULTI: { 456 struct ifreq *ifr = (struct ifreq *) data; 457 if (ifr == 0) { 458 error = EAFNOSUPPORT; /* XXX */ 459 break; 460 } 461 switch (ifr->ifr_addr.sa_family) { 462 #ifdef INET 463 case AF_INET: 464 break; 465 #endif 466 default: 467 error = EAFNOSUPPORT; 468 break; 469 } 470 break; 471 } 472 case SIOCSIFFLAGS: 473 break; 474 default: 475 error = EINVAL; 476 } 477 478 simple_unlock(&tp->tun_lock); 479 splx(s); 480 return (error); 481 } 482 483 /* 484 * tun_output - queue packets from higher level ready to put out. 485 */ 486 int 487 tun_output(ifp, m0, dst, rt) 488 struct ifnet *ifp; 489 struct mbuf *m0; 490 struct sockaddr *dst; 491 struct rtentry *rt; 492 { 493 struct tun_softc *tp = ifp->if_softc; 494 int s; 495 int error; 496 #ifdef INET 497 int mlen; 498 #endif 499 ALTQ_DECL(struct altq_pktattr pktattr;) 500 501 s = splnet(); 502 simple_lock(&tp->tun_lock); 503 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 504 505 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 506 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 507 tp->tun_flags); 508 m_freem (m0); 509 error = EHOSTDOWN; 510 goto out; 511 } 512 513 /* 514 * if the queueing discipline needs packet classification, 515 * do it before prepending link headers. 516 */ 517 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 518 519 #if NBPFILTER > 0 520 if (ifp->if_bpf) 521 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0); 522 #endif 523 524 switch(dst->sa_family) { 525 #ifdef INET 526 case AF_INET: 527 if (tp->tun_flags & TUN_PREPADDR) { 528 /* Simple link-layer header */ 529 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 530 if (m0 == NULL) { 531 IF_DROP(&ifp->if_snd); 532 error = ENOBUFS; 533 goto out; 534 } 535 bcopy(dst, mtod(m0, char *), dst->sa_len); 536 } 537 /* FALLTHROUGH */ 538 case AF_UNSPEC: 539 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 540 if (error) { 541 ifp->if_collisions++; 542 error = EAFNOSUPPORT; 543 goto out; 544 } 545 mlen = m0->m_pkthdr.len; 546 ifp->if_opackets++; 547 ifp->if_obytes += mlen; 548 break; 549 #endif 550 default: 551 m_freem(m0); 552 error = EAFNOSUPPORT; 553 goto out; 554 } 555 556 if (tp->tun_flags & TUN_RWAIT) { 557 tp->tun_flags &= ~TUN_RWAIT; 558 wakeup((caddr_t)tp); 559 } 560 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 561 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 562 NULL); 563 564 selnotify(&tp->tun_rsel, 0); 565 out: 566 simple_unlock(&tp->tun_lock); 567 splx(s); 568 return (0); 569 } 570 571 /* 572 * the cdevsw interface is now pretty minimal. 573 */ 574 int 575 tunioctl(dev, cmd, data, flag, p) 576 dev_t dev; 577 u_long cmd; 578 caddr_t data; 579 int flag; 580 struct proc *p; 581 { 582 struct tun_softc *tp; 583 int s, error = 0; 584 585 s = splnet(); 586 tp = tun_find_unit(dev); 587 588 /* interface was "destroyed" already */ 589 if (tp == NULL) { 590 error = ENXIO; 591 goto out_nolock; 592 } 593 594 switch (cmd) { 595 case TUNSDEBUG: 596 tundebug = *(int *)data; 597 break; 598 599 case TUNGDEBUG: 600 *(int *)data = tundebug; 601 break; 602 603 case TUNSIFMODE: 604 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 605 case IFF_POINTOPOINT: 606 case IFF_BROADCAST: 607 if (tp->tun_if.if_flags & IFF_UP) { 608 error = EBUSY; 609 goto out; 610 } 611 tp->tun_if.if_flags &= 612 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 613 tp->tun_if.if_flags |= *(int *)data; 614 break; 615 default: 616 error = EINVAL; 617 goto out; 618 } 619 break; 620 621 case TUNSLMODE: 622 if (*(int *)data) 623 tp->tun_flags |= TUN_PREPADDR; 624 else 625 tp->tun_flags &= ~TUN_PREPADDR; 626 break; 627 628 case FIONBIO: 629 if (*(int *)data) 630 tp->tun_flags |= TUN_NBIO; 631 else 632 tp->tun_flags &= ~TUN_NBIO; 633 break; 634 635 case FIOASYNC: 636 if (*(int *)data) 637 tp->tun_flags |= TUN_ASYNC; 638 else 639 tp->tun_flags &= ~TUN_ASYNC; 640 break; 641 642 case FIONREAD: 643 if (tp->tun_if.if_snd.ifq_head) 644 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 645 else 646 *(int *)data = 0; 647 break; 648 649 case TIOCSPGRP: 650 case FIOSETOWN: 651 error = fsetown(p, &tp->tun_pgid, cmd, data); 652 break; 653 654 case TIOCGPGRP: 655 case FIOGETOWN: 656 error = fgetown(p, tp->tun_pgid, cmd, data); 657 break; 658 659 default: 660 error = ENOTTY; 661 } 662 663 out: 664 simple_unlock(&tp->tun_lock); 665 out_nolock: 666 splx(s); 667 return (error); 668 } 669 670 /* 671 * The cdevsw read interface - reads a packet at a time, or at 672 * least as much of a packet as can be read. 673 */ 674 int 675 tunread(dev, uio, ioflag) 676 dev_t dev; 677 struct uio *uio; 678 int ioflag; 679 { 680 struct tun_softc *tp; 681 struct ifnet *ifp; 682 struct mbuf *m, *m0; 683 int error = 0, len, s, index; 684 685 s = splnet(); 686 tp = tun_find_unit(dev); 687 688 /* interface was "destroyed" already */ 689 if (tp == NULL) { 690 error = ENXIO; 691 goto out_nolock; 692 } 693 694 index = tp->tun_if.if_index; 695 ifp = &tp->tun_if; 696 697 TUNDEBUG ("%s: read\n", ifp->if_xname); 698 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 699 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 700 error = EHOSTDOWN; 701 goto out; 702 } 703 704 tp->tun_flags &= ~TUN_RWAIT; 705 706 do { 707 IFQ_DEQUEUE(&ifp->if_snd, m0); 708 if (m0 == 0) { 709 if (tp->tun_flags & TUN_NBIO) { 710 error = EWOULDBLOCK; 711 goto out; 712 } 713 tp->tun_flags |= TUN_RWAIT; 714 if (ltsleep((caddr_t)tp, PZERO|PCATCH|PNORELOCK, 715 "tunread", 0, &tp->tun_lock) != 0) { 716 error = EINTR; 717 goto out_nolock; 718 } else { 719 /* 720 * Maybe the interface was destroyed while 721 * we were sleeping, so let's ensure that 722 * we're looking at the same (valid) tun 723 * interface before looping. 724 */ 725 tp = tun_find_unit(dev); 726 if (tp == NULL) { 727 error = ENXIO; 728 goto out_nolock; 729 } 730 if (tp->tun_if.if_index != index) { 731 error = ENXIO; 732 goto out; 733 } 734 } 735 } 736 } while (m0 == 0); 737 738 simple_unlock(&tp->tun_lock); 739 splx(s); 740 741 /* Copy the mbuf chain */ 742 while (m0 && uio->uio_resid > 0 && error == 0) { 743 len = min(uio->uio_resid, m0->m_len); 744 if (len != 0) 745 error = uiomove(mtod(m0, caddr_t), len, uio); 746 MFREE(m0, m); 747 m0 = m; 748 } 749 750 if (m0) { 751 TUNDEBUG("Dropping mbuf\n"); 752 m_freem(m0); 753 } 754 if (error) 755 ifp->if_ierrors++; 756 757 return (error); 758 759 out: 760 simple_unlock(&tp->tun_lock); 761 out_nolock: 762 splx(s); 763 return (error); 764 } 765 766 /* 767 * the cdevsw write interface - an atomic write is a packet - or else! 768 */ 769 int 770 tunwrite(dev, uio, ioflag) 771 dev_t dev; 772 struct uio *uio; 773 int ioflag; 774 { 775 struct tun_softc *tp; 776 struct ifnet *ifp; 777 struct mbuf *top, **mp, *m; 778 struct ifqueue *ifq; 779 struct sockaddr dst; 780 int isr, error = 0, s, tlen, mlen; 781 782 s = splnet(); 783 tp = tun_find_unit(dev); 784 785 /* interface was "destroyed" already */ 786 if (tp == NULL) { 787 error = ENXIO; 788 goto out_nolock; 789 } 790 791 /* Unlock until we've got the data */ 792 simple_unlock(&tp->tun_lock); 793 splx(s); 794 795 ifp = &tp->tun_if; 796 797 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 798 799 if (tp->tun_flags & TUN_PREPADDR) { 800 if (uio->uio_resid < sizeof(dst)) { 801 error = EIO; 802 goto out0; 803 } 804 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 805 if (dst.sa_len > sizeof(dst)) { 806 /* Duh.. */ 807 char discard; 808 int n = dst.sa_len - sizeof(dst); 809 while (n--) 810 if ((error = uiomove(&discard, 1, uio)) != 0) { 811 goto out0; 812 } 813 } 814 } else { 815 #ifdef INET 816 dst.sa_family = AF_INET; 817 #endif 818 } 819 820 if (uio->uio_resid > TUNMTU) { 821 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 822 (unsigned long)uio->uio_resid); 823 error = EIO; 824 goto out0; 825 } 826 827 switch (dst.sa_family) { 828 #ifdef INET 829 case AF_INET: 830 ifq = &ipintrq; 831 isr = NETISR_IP; 832 break; 833 #endif 834 default: 835 error = EAFNOSUPPORT; 836 goto out0; 837 } 838 839 tlen = uio->uio_resid; 840 841 /* get a header mbuf */ 842 MGETHDR(m, M_DONTWAIT, MT_DATA); 843 if (m == NULL) { 844 error = ENOBUFS; 845 goto out0; 846 } 847 mlen = MHLEN; 848 849 top = NULL; 850 mp = ⊤ 851 while (error == 0 && uio->uio_resid > 0) { 852 m->m_len = min(mlen, uio->uio_resid); 853 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 854 *mp = m; 855 mp = &m->m_next; 856 if (error == 0 && uio->uio_resid > 0) { 857 MGET(m, M_DONTWAIT, MT_DATA); 858 if (m == NULL) { 859 error = ENOBUFS; 860 break; 861 } 862 mlen = MLEN; 863 } 864 } 865 if (error) { 866 if (top != NULL) 867 m_freem (top); 868 ifp->if_ierrors++; 869 goto out0; 870 } 871 872 top->m_pkthdr.len = tlen; 873 top->m_pkthdr.rcvif = ifp; 874 875 #if NBPFILTER > 0 876 if (ifp->if_bpf) 877 bpf_mtap_af(ifp->if_bpf, AF_INET, top); 878 #endif 879 880 s = splnet(); 881 simple_lock(&tp->tun_lock); 882 if ((tp->tun_flags & TUN_INITED) == 0) { 883 /* Interface was destroyed */ 884 error = ENXIO; 885 goto out; 886 } 887 if (IF_QFULL(ifq)) { 888 IF_DROP(ifq); 889 ifp->if_collisions++; 890 m_freem(top); 891 error = ENOBUFS; 892 goto out; 893 } 894 895 IF_ENQUEUE(ifq, top); 896 ifp->if_ipackets++; 897 ifp->if_ibytes += tlen; 898 schednetisr(isr); 899 out: 900 simple_unlock(&tp->tun_lock); 901 out_nolock: 902 splx(s); 903 out0: 904 return (error); 905 } 906 907 #ifdef ALTQ 908 /* 909 * Start packet transmission on the interface. 910 * when the interface queue is rate-limited by ALTQ or TBR, 911 * if_start is needed to drain packets from the queue in order 912 * to notify readers when outgoing packets become ready. 913 * 914 * Should be called at splnet. 915 */ 916 static void 917 tunstart(ifp) 918 struct ifnet *ifp; 919 { 920 struct tun_softc *tp = ifp->if_softc; 921 922 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 923 return; 924 925 simple_lock(&tp->tun_lock); 926 if (!IF_IS_EMPTY(&ifp->if_snd)) { 927 if (tp->tun_flags & TUN_RWAIT) { 928 tp->tun_flags &= ~TUN_RWAIT; 929 wakeup((caddr_t)tp); 930 } 931 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 932 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 933 POLLOUT|POLLWRNORM, NULL); 934 935 selwakeup(&tp->tun_rsel); 936 } 937 simple_unlock(&tp->tun_lock); 938 } 939 #endif /* ALTQ */ 940 /* 941 * tunpoll - the poll interface, this is only useful on reads 942 * really. The write detect always returns true, write never blocks 943 * anyway, it either accepts the packet or drops it. 944 */ 945 int 946 tunpoll(dev, events, p) 947 dev_t dev; 948 int events; 949 struct proc *p; 950 { 951 struct tun_softc *tp; 952 struct ifnet *ifp; 953 int s, revents = 0; 954 955 s = splnet(); 956 tp = tun_find_unit(dev); 957 958 /* interface was "destroyed" already */ 959 if (tp == NULL) 960 goto out_nolock; 961 962 ifp = &tp->tun_if; 963 964 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 965 966 if (events & (POLLIN | POLLRDNORM)) { 967 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 968 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 969 ifp->if_snd.ifq_len); 970 revents |= events & (POLLIN | POLLRDNORM); 971 } else { 972 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 973 selrecord(p, &tp->tun_rsel); 974 } 975 } 976 977 if (events & (POLLOUT | POLLWRNORM)) 978 revents |= events & (POLLOUT | POLLWRNORM); 979 980 simple_unlock(&tp->tun_lock); 981 out_nolock: 982 splx(s); 983 return (revents); 984 } 985 986 static void 987 filt_tunrdetach(struct knote *kn) 988 { 989 struct tun_softc *tp = kn->kn_hook; 990 int s; 991 992 s = splnet(); 993 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 994 splx(s); 995 } 996 997 static int 998 filt_tunread(struct knote *kn, long hint) 999 { 1000 struct tun_softc *tp = kn->kn_hook; 1001 struct ifnet *ifp = &tp->tun_if; 1002 struct mbuf *m; 1003 int s; 1004 1005 s = splnet(); 1006 IF_POLL(&ifp->if_snd, m); 1007 if (m == NULL) { 1008 splx(s); 1009 return (0); 1010 } 1011 1012 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1013 kn->kn_data += m->m_len; 1014 1015 splx(s); 1016 return (1); 1017 } 1018 1019 static const struct filterops tunread_filtops = 1020 { 1, NULL, filt_tunrdetach, filt_tunread }; 1021 1022 static const struct filterops tun_seltrue_filtops = 1023 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1024 1025 int 1026 tunkqfilter(dev_t dev, struct knote *kn) 1027 { 1028 struct tun_softc *tp; 1029 struct klist *klist; 1030 int rv = 0, s; 1031 1032 s = splnet(); 1033 tp = tun_find_unit(dev); 1034 if (tp == NULL) 1035 goto out_nolock; 1036 1037 switch (kn->kn_filter) { 1038 case EVFILT_READ: 1039 klist = &tp->tun_rsel.sel_klist; 1040 kn->kn_fop = &tunread_filtops; 1041 break; 1042 1043 case EVFILT_WRITE: 1044 klist = &tp->tun_rsel.sel_klist; 1045 kn->kn_fop = &tun_seltrue_filtops; 1046 break; 1047 1048 default: 1049 rv = 1; 1050 goto out; 1051 } 1052 1053 kn->kn_hook = tp; 1054 1055 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1056 1057 out: 1058 simple_unlock(&tp->tun_lock); 1059 out_nolock: 1060 splx(s); 1061 return (rv); 1062 } 1063
Indexes created Tue Sep 23 07:09:52 GMT 2025