if_tun.c revision 1.87
1 /* $NetBSD: if_tun.c,v 1.87 2006/04/08 12:14:42 rpaulo 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 1.87 2006/04/08 12:14:42 rpaulo 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(int); 73 74 static LIST_HEAD(, tun_softc) tun_softc_list; 75 static LIST_HEAD(, tun_softc) tunz_softc_list; 76 static struct simplelock tun_softc_lock; 77 78 static int tun_ioctl(struct ifnet *, u_long, caddr_t); 79 static int tun_output(struct ifnet *, struct mbuf *, struct sockaddr *, 80 struct rtentry *rt); 81 static int tun_clone_create(struct if_clone *, int); 82 static int tun_clone_destroy(struct ifnet *); 83 84 static struct if_clone tun_cloner = 85 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 86 87 static void tunattach0(struct tun_softc *); 88 static void tuninit(struct tun_softc *); 89 #ifdef ALTQ 90 static void tunstart(struct ifnet *); 91 #endif 92 static struct tun_softc *tun_find_unit(dev_t); 93 static struct tun_softc *tun_find_zunit(int); 94 95 static dev_type_open(tunopen); 96 static dev_type_close(tunclose); 97 static dev_type_read(tunread); 98 static dev_type_write(tunwrite); 99 static dev_type_ioctl(tunioctl); 100 static dev_type_poll(tunpoll); 101 static dev_type_kqfilter(tunkqfilter); 102 103 const struct cdevsw tun_cdevsw = { 104 tunopen, tunclose, tunread, tunwrite, tunioctl, 105 nostop, notty, tunpoll, nommap, tunkqfilter, 106 }; 107 108 void 109 tunattach(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_t dev) 125 { 126 struct tun_softc *tp; 127 int unit = minor(dev); 128 129 simple_lock(&tun_softc_lock); 130 LIST_FOREACH(tp, &tun_softc_list, tun_list) 131 if (unit == tp->tun_unit) 132 break; 133 if (tp) 134 simple_lock(&tp->tun_lock); 135 simple_unlock(&tun_softc_lock); 136 137 return (tp); 138 } 139 140 /* 141 * Find zombie driver instance by unit number. 142 * Call at splnet(). 143 * Remove tp from list and return it unlocked (if found). 144 */ 145 static struct tun_softc * 146 tun_find_zunit(int unit) 147 { 148 struct tun_softc *tp; 149 150 simple_lock(&tun_softc_lock); 151 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 152 if (unit == tp->tun_unit) 153 break; 154 if (tp) 155 LIST_REMOVE(tp, tun_list); 156 simple_unlock(&tun_softc_lock); 157 #ifdef DIAGNOSTIC 158 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 159 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 160 #endif 161 162 return (tp); 163 } 164 165 static int 166 tun_clone_create(struct if_clone *ifc, int unit) 167 { 168 struct tun_softc *tp; 169 170 if ((tp = tun_find_zunit(unit)) == NULL) { 171 /* Allocate a new instance */ 172 tp = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 173 (void)memset(tp, 0, sizeof(struct tun_softc)); 174 175 tp->tun_unit = unit; 176 simple_lock_init(&tp->tun_lock); 177 } else { 178 /* Revive tunnel instance; clear ifp part */ 179 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 180 } 181 182 (void)snprintf(tp->tun_if.if_xname, sizeof(tp->tun_if.if_xname), 183 "%s%d", ifc->ifc_name, unit); 184 tunattach0(tp); 185 tp->tun_flags |= TUN_INITED; 186 187 simple_lock(&tun_softc_lock); 188 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 189 simple_unlock(&tun_softc_lock); 190 191 return (0); 192 } 193 194 static void 195 tunattach0(struct tun_softc *tp) 196 { 197 struct ifnet *ifp; 198 199 ifp = &tp->tun_if; 200 ifp->if_softc = tp; 201 ifp->if_mtu = TUNMTU; 202 ifp->if_ioctl = tun_ioctl; 203 ifp->if_output = tun_output; 204 #ifdef ALTQ 205 ifp->if_start = tunstart; 206 #endif 207 ifp->if_flags = IFF_POINTOPOINT; 208 ifp->if_type = IFT_TUNNEL; 209 ifp->if_snd.ifq_maxlen = ifqmaxlen; 210 ifp->if_collisions = 0; 211 ifp->if_ierrors = 0; 212 ifp->if_oerrors = 0; 213 ifp->if_ipackets = 0; 214 ifp->if_opackets = 0; 215 ifp->if_ibytes = 0; 216 ifp->if_obytes = 0; 217 ifp->if_dlt = DLT_NULL; 218 IFQ_SET_READY(&ifp->if_snd); 219 if_attach(ifp); 220 if_alloc_sadl(ifp); 221 #if NBPFILTER > 0 222 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 223 #endif 224 } 225 226 static int 227 tun_clone_destroy(struct ifnet *ifp) 228 { 229 struct tun_softc *tp = (void *)ifp; 230 int s, zombie = 0; 231 232 s = splnet(); 233 simple_lock(&tun_softc_lock); 234 simple_lock(&tp->tun_lock); 235 LIST_REMOVE(tp, tun_list); 236 if (tp->tun_flags & TUN_OPEN) { 237 /* Hang on to storage until last close */ 238 zombie = 1; 239 tp->tun_flags &= ~TUN_INITED; 240 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 241 } 242 simple_unlock(&tun_softc_lock); 243 244 IF_PURGE(&ifp->if_snd); 245 ifp->if_flags &= ~IFF_RUNNING; 246 247 if (tp->tun_flags & TUN_RWAIT) { 248 tp->tun_flags &= ~TUN_RWAIT; 249 wakeup((caddr_t)tp); 250 } 251 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 252 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 253 254 selwakeup(&tp->tun_rsel); 255 256 simple_unlock(&tp->tun_lock); 257 splx(s); 258 259 #if NBPFILTER > 0 260 bpfdetach(ifp); 261 #endif 262 if_detach(ifp); 263 264 if (!zombie) 265 free(tp, M_DEVBUF); 266 267 return (0); 268 } 269 270 /* 271 * tunnel open - must be superuser & the device must be 272 * configured in 273 */ 274 static int 275 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 276 { 277 struct proc *p = l->l_proc; 278 struct ifnet *ifp; 279 struct tun_softc *tp; 280 int s, error; 281 282 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 283 return (error); 284 285 s = splnet(); 286 tp = tun_find_unit(dev); 287 288 if (tp == NULL) { 289 (void)tun_clone_create(&tun_cloner, minor(dev)); 290 tp = tun_find_unit(dev); 291 if (tp == NULL) { 292 error = ENXIO; 293 goto out_nolock; 294 } 295 } 296 297 if (tp->tun_flags & TUN_OPEN) { 298 error = EBUSY; 299 goto out; 300 } 301 302 ifp = &tp->tun_if; 303 tp->tun_flags |= TUN_OPEN; 304 TUNDEBUG("%s: open\n", ifp->if_xname); 305 out: 306 simple_unlock(&tp->tun_lock); 307 out_nolock: 308 splx(s); 309 return (error); 310 } 311 312 /* 313 * tunclose - close the device - mark i/f down & delete 314 * routing info 315 */ 316 int 317 tunclose(dev_t dev, int flag, int mode, struct lwp *l) 318 { 319 int s; 320 struct tun_softc *tp; 321 struct ifnet *ifp; 322 323 s = splnet(); 324 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 325 /* interface was "destroyed" before the close */ 326 free(tp, M_DEVBUF); 327 goto out_nolock; 328 } 329 330 if ((tp = tun_find_unit(dev)) == NULL) 331 goto out_nolock; 332 333 ifp = &tp->tun_if; 334 335 tp->tun_flags &= ~TUN_OPEN; 336 337 /* 338 * junk all pending output 339 */ 340 IFQ_PURGE(&ifp->if_snd); 341 342 if (ifp->if_flags & IFF_UP) { 343 if_down(ifp); 344 if (ifp->if_flags & IFF_RUNNING) { 345 /* find internet addresses and delete routes */ 346 struct ifaddr *ifa; 347 IFADDR_FOREACH(ifa, ifp) { 348 #if defined(INET) || defined(INET6) 349 if (ifa->ifa_addr->sa_family == AF_INET || 350 ifa->ifa_addr->sa_family == AF_INET6) { 351 rtinit(ifa, (int)RTM_DELETE, 352 tp->tun_flags & TUN_DSTADDR 353 ? RTF_HOST 354 : 0); 355 } 356 #endif 357 } 358 } 359 } 360 tp->tun_pgid = 0; 361 selnotify(&tp->tun_rsel, 0); 362 363 TUNDEBUG ("%s: closed\n", ifp->if_xname); 364 simple_unlock(&tp->tun_lock); 365 out_nolock: 366 splx(s); 367 return (0); 368 } 369 370 /* 371 * Call at splnet() with tp locked. 372 */ 373 static void 374 tuninit(struct tun_softc *tp) 375 { 376 struct ifnet *ifp = &tp->tun_if; 377 struct ifaddr *ifa; 378 379 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 380 381 ifp->if_flags |= IFF_UP | IFF_RUNNING; 382 383 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 384 IFADDR_FOREACH(ifa, ifp) { 385 #ifdef INET 386 if (ifa->ifa_addr->sa_family == AF_INET) { 387 struct sockaddr_in *sin; 388 389 sin = satosin(ifa->ifa_addr); 390 if (sin && sin->sin_addr.s_addr) 391 tp->tun_flags |= TUN_IASET; 392 393 if (ifp->if_flags & IFF_POINTOPOINT) { 394 sin = satosin(ifa->ifa_dstaddr); 395 if (sin && sin->sin_addr.s_addr) 396 tp->tun_flags |= TUN_DSTADDR; 397 } 398 } 399 #endif 400 #ifdef INET6 401 if (ifa->ifa_addr->sa_family == AF_INET6) { 402 struct sockaddr_in6 *sin; 403 404 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 405 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 406 tp->tun_flags |= TUN_IASET; 407 408 if (ifp->if_flags & IFF_POINTOPOINT) { 409 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 410 if (sin && 411 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 412 tp->tun_flags |= TUN_DSTADDR; 413 } else 414 tp->tun_flags &= ~TUN_DSTADDR; 415 } 416 #endif /* INET6 */ 417 } 418 419 return; 420 } 421 422 /* 423 * Process an ioctl request. 424 */ 425 static int 426 tun_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 427 { 428 int error = 0, s; 429 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 430 431 s = splnet(); 432 simple_lock(&tp->tun_lock); 433 434 switch (cmd) { 435 case SIOCSIFADDR: 436 tuninit(tp); 437 TUNDEBUG("%s: address set\n", ifp->if_xname); 438 break; 439 case SIOCSIFDSTADDR: 440 tuninit(tp); 441 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 442 break; 443 case SIOCSIFBRDADDR: 444 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 445 break; 446 case SIOCSIFMTU: { 447 struct ifreq *ifr = (struct ifreq *) data; 448 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 449 error = EINVAL; 450 break; 451 } 452 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 453 ifp->if_mtu = ifr->ifr_mtu; 454 break; 455 } 456 case SIOCADDMULTI: 457 case SIOCDELMULTI: { 458 struct ifreq *ifr = (struct ifreq *) data; 459 if (ifr == 0) { 460 error = EAFNOSUPPORT; /* XXX */ 461 break; 462 } 463 switch (ifr->ifr_addr.sa_family) { 464 #ifdef INET 465 case AF_INET: 466 break; 467 #endif 468 #ifdef INET6 469 case AF_INET6: 470 break; 471 #endif 472 default: 473 error = EAFNOSUPPORT; 474 break; 475 } 476 break; 477 } 478 case SIOCSIFFLAGS: 479 break; 480 default: 481 error = EINVAL; 482 } 483 484 simple_unlock(&tp->tun_lock); 485 splx(s); 486 return (error); 487 } 488 489 /* 490 * tun_output - queue packets from higher level ready to put out. 491 */ 492 static int 493 tun_output(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst, 494 struct rtentry *rt) 495 { 496 struct tun_softc *tp = ifp->if_softc; 497 int s; 498 int error; 499 #if defined(INET) || defined(INET6) 500 int mlen; 501 uint32_t *af; 502 #endif 503 ALTQ_DECL(struct altq_pktattr pktattr;) 504 505 s = splnet(); 506 simple_lock(&tp->tun_lock); 507 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 508 509 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 510 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 511 tp->tun_flags); 512 m_freem (m0); 513 error = EHOSTDOWN; 514 goto out; 515 } 516 517 /* 518 * if the queueing discipline needs packet classification, 519 * do it before prepending link headers. 520 */ 521 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 522 523 #if NBPFILTER > 0 524 if (ifp->if_bpf) 525 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0); 526 #endif 527 528 switch(dst->sa_family) { 529 #ifdef INET6 530 case AF_INET6: 531 #endif 532 #ifdef INET 533 case AF_INET: 534 #endif 535 #if defined(INET) || defined(INET6) 536 if (tp->tun_flags & TUN_PREPADDR) { 537 /* Simple link-layer header */ 538 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 539 if (m0 == NULL) { 540 IF_DROP(&ifp->if_snd); 541 error = ENOBUFS; 542 goto out; 543 } 544 bcopy(dst, mtod(m0, char *), dst->sa_len); 545 } 546 547 if (tp->tun_flags & TUN_IFHEAD) { 548 /* Prepend the address family */ 549 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 550 if (m0 == NULL) { 551 IF_DROP(&ifp->if_snd); 552 error = ENOBUFS; 553 goto out; 554 } 555 af = mtod(m0,uint32_t *); 556 *af = htonl(dst->sa_family); 557 } else { 558 #ifdef INET 559 if (dst->sa_family != AF_INET) 560 #endif 561 { 562 m_freem(m0); 563 error = EAFNOSUPPORT; 564 goto out; 565 } 566 } 567 /* FALLTHROUGH */ 568 case AF_UNSPEC: 569 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 570 if (error) { 571 ifp->if_collisions++; 572 error = EAFNOSUPPORT; 573 goto out; 574 } 575 mlen = m0->m_pkthdr.len; 576 ifp->if_opackets++; 577 ifp->if_obytes += mlen; 578 break; 579 #endif 580 default: 581 m_freem(m0); 582 error = EAFNOSUPPORT; 583 goto out; 584 } 585 586 if (tp->tun_flags & TUN_RWAIT) { 587 tp->tun_flags &= ~TUN_RWAIT; 588 wakeup((caddr_t)tp); 589 } 590 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 591 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 592 NULL); 593 594 selnotify(&tp->tun_rsel, 0); 595 out: 596 simple_unlock(&tp->tun_lock); 597 splx(s); 598 return (0); 599 } 600 601 /* 602 * the cdevsw interface is now pretty minimal. 603 */ 604 int 605 tunioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l) 606 { 607 struct tun_softc *tp; 608 int s, error = 0; 609 610 s = splnet(); 611 tp = tun_find_unit(dev); 612 613 /* interface was "destroyed" already */ 614 if (tp == NULL) { 615 error = ENXIO; 616 goto out_nolock; 617 } 618 619 switch (cmd) { 620 case TUNSDEBUG: 621 tundebug = *(int *)data; 622 break; 623 624 case TUNGDEBUG: 625 *(int *)data = tundebug; 626 break; 627 628 case TUNSIFMODE: 629 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 630 case IFF_POINTOPOINT: 631 case IFF_BROADCAST: 632 if (tp->tun_if.if_flags & IFF_UP) { 633 error = EBUSY; 634 goto out; 635 } 636 tp->tun_if.if_flags &= 637 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 638 tp->tun_if.if_flags |= *(int *)data; 639 break; 640 default: 641 error = EINVAL; 642 goto out; 643 } 644 break; 645 646 case TUNSLMODE: 647 if (*(int *)data) { 648 tp->tun_flags |= TUN_PREPADDR; 649 tp->tun_flags &= ~TUN_IFHEAD; 650 } else 651 tp->tun_flags &= ~TUN_PREPADDR; 652 break; 653 654 case TUNSIFHEAD: 655 if (*(int *)data) { 656 tp->tun_flags |= TUN_IFHEAD; 657 tp->tun_flags &= TUN_PREPADDR; 658 } else 659 tp->tun_flags &= ~TUN_IFHEAD; 660 break; 661 662 case TUNGIFHEAD: 663 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 664 break; 665 666 case FIONBIO: 667 if (*(int *)data) 668 tp->tun_flags |= TUN_NBIO; 669 else 670 tp->tun_flags &= ~TUN_NBIO; 671 break; 672 673 case FIOASYNC: 674 if (*(int *)data) 675 tp->tun_flags |= TUN_ASYNC; 676 else 677 tp->tun_flags &= ~TUN_ASYNC; 678 break; 679 680 case FIONREAD: 681 if (tp->tun_if.if_snd.ifq_head) 682 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 683 else 684 *(int *)data = 0; 685 break; 686 687 case TIOCSPGRP: 688 case FIOSETOWN: 689 error = fsetown(l->l_proc, &tp->tun_pgid, cmd, data); 690 break; 691 692 case TIOCGPGRP: 693 case FIOGETOWN: 694 error = fgetown(l->l_proc, tp->tun_pgid, cmd, data); 695 break; 696 697 default: 698 error = ENOTTY; 699 } 700 701 out: 702 simple_unlock(&tp->tun_lock); 703 out_nolock: 704 splx(s); 705 return (error); 706 } 707 708 /* 709 * The cdevsw read interface - reads a packet at a time, or at 710 * least as much of a packet as can be read. 711 */ 712 int 713 tunread(dev_t dev, struct uio *uio, int ioflag) 714 { 715 struct tun_softc *tp; 716 struct ifnet *ifp; 717 struct mbuf *m, *m0; 718 int error = 0, len, s, index; 719 720 s = splnet(); 721 tp = tun_find_unit(dev); 722 723 /* interface was "destroyed" already */ 724 if (tp == NULL) { 725 error = ENXIO; 726 goto out_nolock; 727 } 728 729 index = tp->tun_if.if_index; 730 ifp = &tp->tun_if; 731 732 TUNDEBUG ("%s: read\n", ifp->if_xname); 733 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 734 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 735 error = EHOSTDOWN; 736 goto out; 737 } 738 739 tp->tun_flags &= ~TUN_RWAIT; 740 741 do { 742 IFQ_DEQUEUE(&ifp->if_snd, m0); 743 if (m0 == 0) { 744 if (tp->tun_flags & TUN_NBIO) { 745 error = EWOULDBLOCK; 746 goto out; 747 } 748 tp->tun_flags |= TUN_RWAIT; 749 if (ltsleep((caddr_t)tp, PZERO|PCATCH|PNORELOCK, 750 "tunread", 0, &tp->tun_lock) != 0) { 751 error = EINTR; 752 goto out_nolock; 753 } else { 754 /* 755 * Maybe the interface was destroyed while 756 * we were sleeping, so let's ensure that 757 * we're looking at the same (valid) tun 758 * interface before looping. 759 */ 760 tp = tun_find_unit(dev); 761 if (tp == NULL) { 762 error = ENXIO; 763 goto out_nolock; 764 } 765 if (tp->tun_if.if_index != index) { 766 error = ENXIO; 767 goto out; 768 } 769 } 770 } 771 } while (m0 == 0); 772 773 simple_unlock(&tp->tun_lock); 774 splx(s); 775 776 /* Copy the mbuf chain */ 777 while (m0 && uio->uio_resid > 0 && error == 0) { 778 len = min(uio->uio_resid, m0->m_len); 779 if (len != 0) 780 error = uiomove(mtod(m0, caddr_t), len, uio); 781 MFREE(m0, m); 782 m0 = m; 783 } 784 785 if (m0) { 786 TUNDEBUG("Dropping mbuf\n"); 787 m_freem(m0); 788 } 789 if (error) 790 ifp->if_ierrors++; 791 792 return (error); 793 794 out: 795 simple_unlock(&tp->tun_lock); 796 out_nolock: 797 splx(s); 798 return (error); 799 } 800 801 /* 802 * the cdevsw write interface - an atomic write is a packet - or else! 803 */ 804 int 805 tunwrite(dev_t dev, struct uio *uio, int ioflag) 806 { 807 struct tun_softc *tp; 808 struct ifnet *ifp; 809 struct mbuf *top, **mp, *m; 810 struct ifqueue *ifq; 811 struct sockaddr dst; 812 int isr, error = 0, s, tlen, mlen; 813 uint32_t family; 814 815 s = splnet(); 816 tp = tun_find_unit(dev); 817 818 /* interface was "destroyed" already */ 819 if (tp == NULL) { 820 error = ENXIO; 821 goto out_nolock; 822 } 823 824 /* Unlock until we've got the data */ 825 simple_unlock(&tp->tun_lock); 826 splx(s); 827 828 ifp = &tp->tun_if; 829 830 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 831 832 if (tp->tun_flags & TUN_PREPADDR) { 833 if (uio->uio_resid < sizeof(dst)) { 834 error = EIO; 835 goto out0; 836 } 837 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 838 if (dst.sa_len > sizeof(dst)) { 839 /* Duh.. */ 840 char discard; 841 int n = dst.sa_len - sizeof(dst); 842 while (n--) 843 if ((error = uiomove(&discard, 1, uio)) != 0) { 844 goto out0; 845 } 846 } 847 } else if (tp->tun_flags & TUN_IFHEAD) { 848 if (uio->uio_resid < sizeof(family)){ 849 error = EIO; 850 goto out0; 851 } 852 error = uiomove((caddr_t)&family, sizeof(family), uio); 853 dst.sa_family = ntohl(family); 854 } else { 855 #ifdef INET 856 dst.sa_family = AF_INET; 857 #endif 858 } 859 860 if (uio->uio_resid > TUNMTU) { 861 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 862 (unsigned long)uio->uio_resid); 863 error = EIO; 864 goto out0; 865 } 866 867 switch (dst.sa_family) { 868 #ifdef INET 869 case AF_INET: 870 ifq = &ipintrq; 871 isr = NETISR_IP; 872 break; 873 #endif 874 #ifdef INET6 875 case AF_INET6: 876 ifq = &ip6intrq; 877 isr = NETISR_IPV6; 878 break; 879 #endif 880 default: 881 error = EAFNOSUPPORT; 882 goto out0; 883 } 884 885 tlen = uio->uio_resid; 886 887 /* get a header mbuf */ 888 MGETHDR(m, M_DONTWAIT, MT_DATA); 889 if (m == NULL) { 890 error = ENOBUFS; 891 goto out0; 892 } 893 mlen = MHLEN; 894 895 top = NULL; 896 mp = ⊤ 897 while (error == 0 && uio->uio_resid > 0) { 898 m->m_len = min(mlen, uio->uio_resid); 899 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 900 *mp = m; 901 mp = &m->m_next; 902 if (error == 0 && uio->uio_resid > 0) { 903 MGET(m, M_DONTWAIT, MT_DATA); 904 if (m == NULL) { 905 error = ENOBUFS; 906 break; 907 } 908 mlen = MLEN; 909 } 910 } 911 if (error) { 912 if (top != NULL) 913 m_freem (top); 914 ifp->if_ierrors++; 915 goto out0; 916 } 917 918 top->m_pkthdr.len = tlen; 919 top->m_pkthdr.rcvif = ifp; 920 921 #if NBPFILTER > 0 922 if (ifp->if_bpf) 923 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 924 #endif 925 926 s = splnet(); 927 simple_lock(&tp->tun_lock); 928 if ((tp->tun_flags & TUN_INITED) == 0) { 929 /* Interface was destroyed */ 930 error = ENXIO; 931 goto out; 932 } 933 if (IF_QFULL(ifq)) { 934 IF_DROP(ifq); 935 ifp->if_collisions++; 936 m_freem(top); 937 error = ENOBUFS; 938 goto out; 939 } 940 941 IF_ENQUEUE(ifq, top); 942 ifp->if_ipackets++; 943 ifp->if_ibytes += tlen; 944 schednetisr(isr); 945 out: 946 simple_unlock(&tp->tun_lock); 947 out_nolock: 948 splx(s); 949 out0: 950 return (error); 951 } 952 953 #ifdef ALTQ 954 /* 955 * Start packet transmission on the interface. 956 * when the interface queue is rate-limited by ALTQ or TBR, 957 * if_start is needed to drain packets from the queue in order 958 * to notify readers when outgoing packets become ready. 959 * 960 * Should be called at splnet. 961 */ 962 static void 963 tunstart(struct ifnet *ifp) 964 { 965 struct tun_softc *tp = ifp->if_softc; 966 967 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 968 return; 969 970 simple_lock(&tp->tun_lock); 971 if (!IF_IS_EMPTY(&ifp->if_snd)) { 972 if (tp->tun_flags & TUN_RWAIT) { 973 tp->tun_flags &= ~TUN_RWAIT; 974 wakeup((caddr_t)tp); 975 } 976 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 977 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 978 POLLOUT|POLLWRNORM, NULL); 979 980 selwakeup(&tp->tun_rsel); 981 } 982 simple_unlock(&tp->tun_lock); 983 } 984 #endif /* ALTQ */ 985 /* 986 * tunpoll - the poll interface, this is only useful on reads 987 * really. The write detect always returns true, write never blocks 988 * anyway, it either accepts the packet or drops it. 989 */ 990 int 991 tunpoll(dev_t dev, int events, struct lwp *l) 992 { 993 struct tun_softc *tp; 994 struct ifnet *ifp; 995 int s, revents = 0; 996 997 s = splnet(); 998 tp = tun_find_unit(dev); 999 1000 /* interface was "destroyed" already */ 1001 if (tp == NULL) 1002 goto out_nolock; 1003 1004 ifp = &tp->tun_if; 1005 1006 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1007 1008 if (events & (POLLIN | POLLRDNORM)) { 1009 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1010 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1011 ifp->if_snd.ifq_len); 1012 revents |= events & (POLLIN | POLLRDNORM); 1013 } else { 1014 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1015 selrecord(l, &tp->tun_rsel); 1016 } 1017 } 1018 1019 if (events & (POLLOUT | POLLWRNORM)) 1020 revents |= events & (POLLOUT | POLLWRNORM); 1021 1022 simple_unlock(&tp->tun_lock); 1023 out_nolock: 1024 splx(s); 1025 return (revents); 1026 } 1027 1028 static void 1029 filt_tunrdetach(struct knote *kn) 1030 { 1031 struct tun_softc *tp = kn->kn_hook; 1032 int s; 1033 1034 s = splnet(); 1035 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1036 splx(s); 1037 } 1038 1039 static int 1040 filt_tunread(struct knote *kn, long hint) 1041 { 1042 struct tun_softc *tp = kn->kn_hook; 1043 struct ifnet *ifp = &tp->tun_if; 1044 struct mbuf *m; 1045 int s; 1046 1047 s = splnet(); 1048 IF_POLL(&ifp->if_snd, m); 1049 if (m == NULL) { 1050 splx(s); 1051 return (0); 1052 } 1053 1054 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1055 kn->kn_data += m->m_len; 1056 1057 splx(s); 1058 return (1); 1059 } 1060 1061 static const struct filterops tunread_filtops = 1062 { 1, NULL, filt_tunrdetach, filt_tunread }; 1063 1064 static const struct filterops tun_seltrue_filtops = 1065 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1066 1067 int 1068 tunkqfilter(dev_t dev, struct knote *kn) 1069 { 1070 struct tun_softc *tp; 1071 struct klist *klist; 1072 int rv = 0, s; 1073 1074 s = splnet(); 1075 tp = tun_find_unit(dev); 1076 if (tp == NULL) 1077 goto out_nolock; 1078 1079 switch (kn->kn_filter) { 1080 case EVFILT_READ: 1081 klist = &tp->tun_rsel.sel_klist; 1082 kn->kn_fop = &tunread_filtops; 1083 break; 1084 1085 case EVFILT_WRITE: 1086 klist = &tp->tun_rsel.sel_klist; 1087 kn->kn_fop = &tun_seltrue_filtops; 1088 break; 1089 1090 default: 1091 rv = 1; 1092 goto out; 1093 } 1094 1095 kn->kn_hook = tp; 1096 1097 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1098 1099 out: 1100 simple_unlock(&tp->tun_lock); 1101 out_nolock: 1102 splx(s); 1103 return (rv); 1104 } 1105
Indexes created Tue Sep 23 21:09:50 GMT 2025