if_tun.c revision 1.120.4.1
1 /* $NetBSD: if_tun.c,v 1.120.4.1 2015/06/06 14:40:25 skrll 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 1.120.4.1 2015/06/06 14:40:25 skrll Exp $"); 19 20 #include "opt_inet.h" 21 22 #include <sys/param.h> 23 #include <sys/proc.h> 24 #include <sys/systm.h> 25 #include <sys/mbuf.h> 26 #include <sys/buf.h> 27 #include <sys/protosw.h> 28 #include <sys/socket.h> 29 #include <sys/ioctl.h> 30 #include <sys/errno.h> 31 #include <sys/syslog.h> 32 #include <sys/select.h> 33 #include <sys/poll.h> 34 #include <sys/file.h> 35 #include <sys/signalvar.h> 36 #include <sys/conf.h> 37 #include <sys/kauth.h> 38 #include <sys/mutex.h> 39 #include <sys/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 56 #include <sys/time.h> 57 #include <net/bpf.h> 58 59 #include <net/if_tun.h> 60 61 #define TUNDEBUG if (tundebug) printf 62 int tundebug = 0; 63 64 extern int ifqmaxlen; 65 void tunattach(int); 66 67 static LIST_HEAD(, tun_softc) tun_softc_list; 68 static LIST_HEAD(, tun_softc) tunz_softc_list; 69 static kmutex_t tun_softc_lock; 70 71 static int tun_ioctl(struct ifnet *, u_long, void *); 72 static int tun_output(struct ifnet *, struct mbuf *, 73 const struct sockaddr *, struct rtentry *rt); 74 static int tun_clone_create(struct if_clone *, int); 75 static int tun_clone_destroy(struct ifnet *); 76 77 static struct if_clone tun_cloner = 78 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 79 80 static void tunattach0(struct tun_softc *); 81 static void tuninit(struct tun_softc *); 82 static void tun_i_softintr(void *); 83 static void tun_o_softintr(void *); 84 #ifdef ALTQ 85 static void tunstart(struct ifnet *); 86 #endif 87 static struct tun_softc *tun_find_unit(dev_t); 88 static struct tun_softc *tun_find_zunit(int); 89 90 static dev_type_open(tunopen); 91 static dev_type_close(tunclose); 92 static dev_type_read(tunread); 93 static dev_type_write(tunwrite); 94 static dev_type_ioctl(tunioctl); 95 static dev_type_poll(tunpoll); 96 static dev_type_kqfilter(tunkqfilter); 97 98 const struct cdevsw tun_cdevsw = { 99 .d_open = tunopen, 100 .d_close = tunclose, 101 .d_read = tunread, 102 .d_write = tunwrite, 103 .d_ioctl = tunioctl, 104 .d_stop = nostop, 105 .d_tty = notty, 106 .d_poll = tunpoll, 107 .d_mmap = nommap, 108 .d_kqfilter = tunkqfilter, 109 .d_discard = nodiscard, 110 .d_flag = D_OTHER 111 }; 112 113 void 114 tunattach(int unused) 115 { 116 117 mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NET); 118 LIST_INIT(&tun_softc_list); 119 LIST_INIT(&tunz_softc_list); 120 if_clone_attach(&tun_cloner); 121 } 122 123 /* 124 * Find driver instance from dev_t. 125 * Returns with tp locked (if found). 126 */ 127 static struct tun_softc * 128 tun_find_unit(dev_t dev) 129 { 130 struct tun_softc *tp; 131 int unit = minor(dev); 132 133 mutex_enter(&tun_softc_lock); 134 LIST_FOREACH(tp, &tun_softc_list, tun_list) 135 if (unit == tp->tun_unit) 136 break; 137 if (tp) 138 mutex_enter(&tp->tun_lock); 139 mutex_exit(&tun_softc_lock); 140 141 return (tp); 142 } 143 144 /* 145 * Find zombie driver instance by unit number. 146 * Remove tp from list and return it unlocked (if found). 147 */ 148 static struct tun_softc * 149 tun_find_zunit(int unit) 150 { 151 struct tun_softc *tp; 152 153 mutex_enter(&tun_softc_lock); 154 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 155 if (unit == tp->tun_unit) 156 break; 157 if (tp) 158 LIST_REMOVE(tp, tun_list); 159 mutex_exit(&tun_softc_lock); 160 #ifdef DIAGNOSTIC 161 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 162 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 163 #endif 164 165 return (tp); 166 } 167 168 static int 169 tun_clone_create(struct if_clone *ifc, int unit) 170 { 171 struct tun_softc *tp; 172 173 if ((tp = tun_find_zunit(unit)) == NULL) { 174 /* Allocate a new instance */ 175 tp = malloc(sizeof(*tp), M_DEVBUF, M_WAITOK|M_ZERO); 176 177 tp->tun_unit = unit; 178 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 179 selinit(&tp->tun_rsel); 180 selinit(&tp->tun_wsel); 181 } else { 182 /* Revive tunnel instance; clear ifp part */ 183 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 184 } 185 186 if_initname(&tp->tun_if, ifc->ifc_name, unit); 187 tunattach0(tp); 188 tp->tun_flags |= TUN_INITED; 189 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 190 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 191 192 mutex_enter(&tun_softc_lock); 193 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 194 mutex_exit(&tun_softc_lock); 195 196 return (0); 197 } 198 199 static void 200 tunattach0(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 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 227 } 228 229 static int 230 tun_clone_destroy(struct ifnet *ifp) 231 { 232 struct tun_softc *tp = (void *)ifp; 233 int zombie = 0; 234 235 IF_PURGE(&ifp->if_snd); 236 ifp->if_flags &= ~IFF_RUNNING; 237 238 mutex_enter(&tun_softc_lock); 239 mutex_enter(&tp->tun_lock); 240 LIST_REMOVE(tp, tun_list); 241 if (tp->tun_flags & TUN_OPEN) { 242 /* Hang on to storage until last close */ 243 zombie = 1; 244 tp->tun_flags &= ~TUN_INITED; 245 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 246 } 247 mutex_exit(&tun_softc_lock); 248 249 if (tp->tun_flags & TUN_RWAIT) { 250 tp->tun_flags &= ~TUN_RWAIT; 251 wakeup((void *)tp); 252 } 253 selnotify(&tp->tun_rsel, 0, 0); 254 255 mutex_exit(&tp->tun_lock); 256 257 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 258 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 259 260 bpf_detach(ifp); 261 if_detach(ifp); 262 263 if (!zombie) { 264 seldestroy(&tp->tun_rsel); 265 seldestroy(&tp->tun_wsel); 266 softint_disestablish(tp->tun_osih); 267 softint_disestablish(tp->tun_isih); 268 mutex_destroy(&tp->tun_lock); 269 free(tp, M_DEVBUF); 270 } 271 272 return (0); 273 } 274 275 /* 276 * tunnel open - must be superuser & the device must be 277 * configured in 278 */ 279 static int 280 tunopen(dev_t dev, int flag, int mode, struct lwp *l) 281 { 282 struct ifnet *ifp; 283 struct tun_softc *tp; 284 int error; 285 286 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 287 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 288 if (error) 289 return (error); 290 291 tp = tun_find_unit(dev); 292 293 if (tp == NULL) { 294 (void)tun_clone_create(&tun_cloner, minor(dev)); 295 tp = tun_find_unit(dev); 296 if (tp == NULL) { 297 error = ENXIO; 298 goto out_nolock; 299 } 300 } 301 302 if (tp->tun_flags & TUN_OPEN) { 303 error = EBUSY; 304 goto out; 305 } 306 307 ifp = &tp->tun_if; 308 tp->tun_flags |= TUN_OPEN; 309 TUNDEBUG("%s: open\n", ifp->if_xname); 310 out: 311 mutex_exit(&tp->tun_lock); 312 out_nolock: 313 return (error); 314 } 315 316 /* 317 * tunclose - close the device - mark i/f down & delete 318 * routing info 319 */ 320 int 321 tunclose(dev_t dev, int flag, int mode, 322 struct lwp *l) 323 { 324 struct tun_softc *tp; 325 struct ifnet *ifp; 326 327 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 328 /* interface was "destroyed" before the close */ 329 seldestroy(&tp->tun_rsel); 330 seldestroy(&tp->tun_wsel); 331 softint_disestablish(tp->tun_osih); 332 softint_disestablish(tp->tun_isih); 333 mutex_destroy(&tp->tun_lock); 334 free(tp, M_DEVBUF); 335 goto out_nolock; 336 } 337 338 if ((tp = tun_find_unit(dev)) == NULL) 339 goto out_nolock; 340 341 ifp = &tp->tun_if; 342 343 tp->tun_flags &= ~TUN_OPEN; 344 345 tp->tun_pgid = 0; 346 selnotify(&tp->tun_rsel, 0, 0); 347 348 TUNDEBUG ("%s: closed\n", ifp->if_xname); 349 mutex_exit(&tp->tun_lock); 350 351 /* 352 * junk all pending output 353 */ 354 IFQ_PURGE(&ifp->if_snd); 355 356 if (ifp->if_flags & IFF_UP) { 357 if_down(ifp); 358 if (ifp->if_flags & IFF_RUNNING) { 359 /* find internet addresses and delete routes */ 360 struct ifaddr *ifa; 361 IFADDR_FOREACH(ifa, ifp) { 362 #if defined(INET) || defined(INET6) 363 if (ifa->ifa_addr->sa_family == AF_INET || 364 ifa->ifa_addr->sa_family == AF_INET6) { 365 rtinit(ifa, (int)RTM_DELETE, 366 tp->tun_flags & TUN_DSTADDR 367 ? RTF_HOST 368 : 0); 369 } 370 #endif 371 } 372 } 373 } 374 out_nolock: 375 return (0); 376 } 377 378 /* 379 * Call at splnet(). 380 */ 381 static void 382 tuninit(struct tun_softc *tp) 383 { 384 struct ifnet *ifp = &tp->tun_if; 385 struct ifaddr *ifa; 386 387 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 388 389 mutex_enter(&tp->tun_lock); 390 ifp->if_flags |= IFF_UP | IFF_RUNNING; 391 392 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 393 IFADDR_FOREACH(ifa, ifp) { 394 #ifdef INET 395 if (ifa->ifa_addr->sa_family == AF_INET) { 396 struct sockaddr_in *sin; 397 398 sin = satosin(ifa->ifa_addr); 399 if (sin && sin->sin_addr.s_addr) 400 tp->tun_flags |= TUN_IASET; 401 402 if (ifp->if_flags & IFF_POINTOPOINT) { 403 sin = satosin(ifa->ifa_dstaddr); 404 if (sin && sin->sin_addr.s_addr) 405 tp->tun_flags |= TUN_DSTADDR; 406 } 407 } 408 #endif 409 #ifdef INET6 410 if (ifa->ifa_addr->sa_family == AF_INET6) { 411 struct sockaddr_in6 *sin; 412 413 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 414 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 415 tp->tun_flags |= TUN_IASET; 416 417 if (ifp->if_flags & IFF_POINTOPOINT) { 418 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 419 if (sin && 420 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 421 tp->tun_flags |= TUN_DSTADDR; 422 } else 423 tp->tun_flags &= ~TUN_DSTADDR; 424 } 425 #endif /* INET6 */ 426 } 427 mutex_exit(&tp->tun_lock); 428 } 429 430 /* 431 * Process an ioctl request. 432 */ 433 static int 434 tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) 435 { 436 int error = 0, s; 437 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 438 struct ifreq *ifr = (struct ifreq *)data; 439 struct ifaddr *ifa = (struct ifaddr *)data; 440 441 s = splnet(); 442 443 switch (cmd) { 444 case SIOCINITIFADDR: 445 tuninit(tp); 446 ifa->ifa_rtrequest = p2p_rtrequest; 447 TUNDEBUG("%s: address set\n", ifp->if_xname); 448 break; 449 case SIOCSIFBRDADDR: 450 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 451 break; 452 case SIOCSIFMTU: 453 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 454 error = EINVAL; 455 break; 456 } 457 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 458 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 459 error = 0; 460 break; 461 case SIOCADDMULTI: 462 case SIOCDELMULTI: 463 if (ifr == NULL) { 464 error = EAFNOSUPPORT; /* XXX */ 465 break; 466 } 467 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 468 #ifdef INET 469 case AF_INET: 470 break; 471 #endif 472 #ifdef INET6 473 case AF_INET6: 474 break; 475 #endif 476 default: 477 error = EAFNOSUPPORT; 478 break; 479 } 480 break; 481 default: 482 error = ifioctl_common(ifp, cmd, data); 483 } 484 485 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, const 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 mutex_enter(&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 error = EHOSTDOWN; 513 goto out; 514 } 515 516 /* 517 * if the queueing discipline needs packet classification, 518 * do it before prepending link headers. 519 */ 520 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 521 522 bpf_mtap_af(ifp, dst->sa_family, m0); 523 524 switch(dst->sa_family) { 525 #ifdef INET6 526 case AF_INET6: 527 #endif 528 #ifdef INET 529 case AF_INET: 530 #endif 531 #if defined(INET) || defined(INET6) 532 if (tp->tun_flags & TUN_PREPADDR) { 533 /* Simple link-layer header */ 534 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 535 if (m0 == NULL) { 536 IF_DROP(&ifp->if_snd); 537 error = ENOBUFS; 538 goto out; 539 } 540 bcopy(dst, mtod(m0, char *), dst->sa_len); 541 } 542 543 if (tp->tun_flags & TUN_IFHEAD) { 544 /* Prepend the address family */ 545 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 546 if (m0 == NULL) { 547 IF_DROP(&ifp->if_snd); 548 error = ENOBUFS; 549 goto out; 550 } 551 af = mtod(m0,uint32_t *); 552 *af = htonl(dst->sa_family); 553 } else { 554 #ifdef INET 555 if (dst->sa_family != AF_INET) 556 #endif 557 { 558 error = EAFNOSUPPORT; 559 goto out; 560 } 561 } 562 /* FALLTHROUGH */ 563 case AF_UNSPEC: 564 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 565 if (error) { 566 ifp->if_collisions++; 567 error = EAFNOSUPPORT; 568 m0 = NULL; 569 goto out; 570 } 571 mlen = m0->m_pkthdr.len; 572 ifp->if_opackets++; 573 ifp->if_obytes += mlen; 574 break; 575 #endif 576 default: 577 error = EAFNOSUPPORT; 578 goto out; 579 } 580 581 if (tp->tun_flags & TUN_RWAIT) { 582 tp->tun_flags &= ~TUN_RWAIT; 583 wakeup((void *)tp); 584 } 585 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 586 softint_schedule(tp->tun_isih); 587 588 selnotify(&tp->tun_rsel, 0, 0); 589 out: 590 mutex_exit(&tp->tun_lock); 591 splx(s); 592 593 if (error && m0) { 594 m_freem(m0); 595 } 596 return 0; 597 } 598 599 static void 600 tun_i_softintr(void *cookie) 601 { 602 struct tun_softc *tp = cookie; 603 604 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 605 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 606 NULL); 607 } 608 609 static void 610 tun_o_softintr(void *cookie) 611 { 612 struct tun_softc *tp = cookie; 613 614 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 615 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, 616 NULL); 617 } 618 619 /* 620 * the cdevsw interface is now pretty minimal. 621 */ 622 int 623 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 624 { 625 struct tun_softc *tp; 626 int s, error = 0; 627 628 s = splnet(); 629 tp = tun_find_unit(dev); 630 631 /* interface was "destroyed" already */ 632 if (tp == NULL) { 633 error = ENXIO; 634 goto out_nolock; 635 } 636 637 switch (cmd) { 638 case TUNSDEBUG: 639 tundebug = *(int *)data; 640 break; 641 642 case TUNGDEBUG: 643 *(int *)data = tundebug; 644 break; 645 646 case TUNSIFMODE: 647 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 648 case IFF_POINTOPOINT: 649 case IFF_BROADCAST: 650 if (tp->tun_if.if_flags & IFF_UP) { 651 error = EBUSY; 652 goto out; 653 } 654 tp->tun_if.if_flags &= 655 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 656 tp->tun_if.if_flags |= *(int *)data; 657 break; 658 default: 659 error = EINVAL; 660 goto out; 661 } 662 break; 663 664 case TUNSLMODE: 665 if (*(int *)data) { 666 tp->tun_flags |= TUN_PREPADDR; 667 tp->tun_flags &= ~TUN_IFHEAD; 668 } else 669 tp->tun_flags &= ~TUN_PREPADDR; 670 break; 671 672 case TUNSIFHEAD: 673 if (*(int *)data) { 674 tp->tun_flags |= TUN_IFHEAD; 675 tp->tun_flags &= ~TUN_PREPADDR; 676 } else 677 tp->tun_flags &= ~TUN_IFHEAD; 678 break; 679 680 case TUNGIFHEAD: 681 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 682 break; 683 684 case FIONBIO: 685 if (*(int *)data) 686 tp->tun_flags |= TUN_NBIO; 687 else 688 tp->tun_flags &= ~TUN_NBIO; 689 break; 690 691 case FIOASYNC: 692 if (*(int *)data) 693 tp->tun_flags |= TUN_ASYNC; 694 else 695 tp->tun_flags &= ~TUN_ASYNC; 696 break; 697 698 case FIONREAD: 699 if (tp->tun_if.if_snd.ifq_head) 700 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 701 else 702 *(int *)data = 0; 703 break; 704 705 case TIOCSPGRP: 706 case FIOSETOWN: 707 error = fsetown(&tp->tun_pgid, cmd, data); 708 break; 709 710 case TIOCGPGRP: 711 case FIOGETOWN: 712 error = fgetown(tp->tun_pgid, cmd, data); 713 break; 714 715 default: 716 error = ENOTTY; 717 } 718 719 out: 720 mutex_exit(&tp->tun_lock); 721 out_nolock: 722 splx(s); 723 return (error); 724 } 725 726 /* 727 * The cdevsw read interface - reads a packet at a time, or at 728 * least as much of a packet as can be read. 729 */ 730 int 731 tunread(dev_t dev, struct uio *uio, int ioflag) 732 { 733 struct tun_softc *tp; 734 struct ifnet *ifp; 735 struct mbuf *m, *m0; 736 int error = 0, len, s, index; 737 738 s = splnet(); 739 tp = tun_find_unit(dev); 740 741 /* interface was "destroyed" already */ 742 if (tp == NULL) { 743 error = ENXIO; 744 goto out_nolock; 745 } 746 747 index = tp->tun_if.if_index; 748 ifp = &tp->tun_if; 749 750 TUNDEBUG ("%s: read\n", ifp->if_xname); 751 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 752 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 753 error = EHOSTDOWN; 754 goto out; 755 } 756 757 tp->tun_flags &= ~TUN_RWAIT; 758 759 do { 760 IFQ_DEQUEUE(&ifp->if_snd, m0); 761 if (m0 == 0) { 762 if (tp->tun_flags & TUN_NBIO) { 763 error = EWOULDBLOCK; 764 goto out; 765 } 766 tp->tun_flags |= TUN_RWAIT; 767 if (mtsleep((void *)tp, PZERO|PCATCH|PNORELOCK, 768 "tunread", 0, &tp->tun_lock) != 0) { 769 error = EINTR; 770 goto out_nolock; 771 } else { 772 /* 773 * Maybe the interface was destroyed while 774 * we were sleeping, so let's ensure that 775 * we're looking at the same (valid) tun 776 * interface before looping. 777 */ 778 tp = tun_find_unit(dev); 779 if (tp == NULL) { 780 error = ENXIO; 781 goto out_nolock; 782 } 783 if (tp->tun_if.if_index != index) { 784 error = ENXIO; 785 goto out; 786 } 787 } 788 } 789 } while (m0 == 0); 790 791 mutex_exit(&tp->tun_lock); 792 splx(s); 793 794 /* Copy the mbuf chain */ 795 while (m0 && uio->uio_resid > 0 && error == 0) { 796 len = min(uio->uio_resid, m0->m_len); 797 if (len != 0) 798 error = uiomove(mtod(m0, void *), len, uio); 799 MFREE(m0, m); 800 m0 = m; 801 } 802 803 if (m0) { 804 TUNDEBUG("Dropping mbuf\n"); 805 m_freem(m0); 806 } 807 if (error) 808 ifp->if_ierrors++; 809 810 return (error); 811 812 out: 813 mutex_exit(&tp->tun_lock); 814 out_nolock: 815 splx(s); 816 return (error); 817 } 818 819 /* 820 * the cdevsw write interface - an atomic write is a packet - or else! 821 */ 822 int 823 tunwrite(dev_t dev, struct uio *uio, int ioflag) 824 { 825 struct tun_softc *tp; 826 struct ifnet *ifp; 827 struct mbuf *top, **mp, *m; 828 pktqueue_t *pktq; 829 struct sockaddr dst; 830 int error = 0, s, tlen, mlen; 831 uint32_t family; 832 833 s = splnet(); 834 tp = tun_find_unit(dev); 835 836 /* interface was "destroyed" already */ 837 if (tp == NULL) { 838 error = ENXIO; 839 goto out_nolock; 840 } 841 842 /* Unlock until we've got the data */ 843 mutex_exit(&tp->tun_lock); 844 splx(s); 845 846 ifp = &tp->tun_if; 847 848 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 849 850 if (tp->tun_flags & TUN_PREPADDR) { 851 if (uio->uio_resid < sizeof(dst)) { 852 error = EIO; 853 goto out0; 854 } 855 error = uiomove((void *)&dst, sizeof(dst), uio); 856 if (dst.sa_len > sizeof(dst)) { 857 /* Duh.. */ 858 char discard; 859 int n = dst.sa_len - sizeof(dst); 860 while (n--) 861 if ((error = uiomove(&discard, 1, uio)) != 0) { 862 goto out0; 863 } 864 } 865 } else if (tp->tun_flags & TUN_IFHEAD) { 866 if (uio->uio_resid < sizeof(family)){ 867 error = EIO; 868 goto out0; 869 } 870 error = uiomove((void *)&family, sizeof(family), uio); 871 dst.sa_family = ntohl(family); 872 } else { 873 #ifdef INET 874 dst.sa_family = AF_INET; 875 #endif 876 } 877 878 if (uio->uio_resid > TUNMTU) { 879 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 880 (unsigned long)uio->uio_resid); 881 error = EIO; 882 goto out0; 883 } 884 885 switch (dst.sa_family) { 886 #ifdef INET 887 case AF_INET: 888 pktq = ip_pktq; 889 break; 890 #endif 891 #ifdef INET6 892 case AF_INET6: 893 pktq = ip6_pktq; 894 break; 895 #endif 896 default: 897 error = EAFNOSUPPORT; 898 goto out0; 899 } 900 901 tlen = uio->uio_resid; 902 903 /* get a header mbuf */ 904 MGETHDR(m, M_DONTWAIT, MT_DATA); 905 if (m == NULL) { 906 error = ENOBUFS; 907 goto out0; 908 } 909 mlen = MHLEN; 910 911 top = NULL; 912 mp = ⊤ 913 while (error == 0 && uio->uio_resid > 0) { 914 m->m_len = min(mlen, uio->uio_resid); 915 error = uiomove(mtod(m, void *), m->m_len, uio); 916 *mp = m; 917 mp = &m->m_next; 918 if (error == 0 && uio->uio_resid > 0) { 919 MGET(m, M_DONTWAIT, MT_DATA); 920 if (m == NULL) { 921 error = ENOBUFS; 922 break; 923 } 924 mlen = MLEN; 925 } 926 } 927 if (error) { 928 if (top != NULL) 929 m_freem (top); 930 ifp->if_ierrors++; 931 goto out0; 932 } 933 934 top->m_pkthdr.len = tlen; 935 top->m_pkthdr.rcvif = ifp; 936 937 bpf_mtap_af(ifp, dst.sa_family, top); 938 939 s = splnet(); 940 mutex_enter(&tp->tun_lock); 941 if ((tp->tun_flags & TUN_INITED) == 0) { 942 /* Interface was destroyed */ 943 error = ENXIO; 944 goto out; 945 } 946 if (__predict_false(!pktq_enqueue(pktq, top, 0))) { 947 ifp->if_collisions++; 948 mutex_exit(&tp->tun_lock); 949 error = ENOBUFS; 950 m_freem(top); 951 goto out_nolock; 952 } 953 ifp->if_ipackets++; 954 ifp->if_ibytes += tlen; 955 out: 956 mutex_exit(&tp->tun_lock); 957 out_nolock: 958 splx(s); 959 out0: 960 return (error); 961 } 962 963 #ifdef ALTQ 964 /* 965 * Start packet transmission on the interface. 966 * when the interface queue is rate-limited by ALTQ or TBR, 967 * if_start is needed to drain packets from the queue in order 968 * to notify readers when outgoing packets become ready. 969 * 970 * Should be called at splnet. 971 */ 972 static void 973 tunstart(struct ifnet *ifp) 974 { 975 struct tun_softc *tp = ifp->if_softc; 976 977 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 978 return; 979 980 mutex_enter(&tp->tun_lock); 981 if (!IF_IS_EMPTY(&ifp->if_snd)) { 982 if (tp->tun_flags & TUN_RWAIT) { 983 tp->tun_flags &= ~TUN_RWAIT; 984 wakeup((void *)tp); 985 } 986 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 987 softint_schedule(tp->tun_osih); 988 989 selnotify(&tp->tun_rsel, 0, 0); 990 } 991 mutex_exit(&tp->tun_lock); 992 } 993 #endif /* ALTQ */ 994 /* 995 * tunpoll - the poll interface, this is only useful on reads 996 * really. The write detect always returns true, write never blocks 997 * anyway, it either accepts the packet or drops it. 998 */ 999 int 1000 tunpoll(dev_t dev, int events, struct lwp *l) 1001 { 1002 struct tun_softc *tp; 1003 struct ifnet *ifp; 1004 int s, revents = 0; 1005 1006 s = splnet(); 1007 tp = tun_find_unit(dev); 1008 1009 /* interface was "destroyed" already */ 1010 if (tp == NULL) 1011 goto out_nolock; 1012 1013 ifp = &tp->tun_if; 1014 1015 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1016 1017 if (events & (POLLIN | POLLRDNORM)) { 1018 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1019 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1020 ifp->if_snd.ifq_len); 1021 revents |= events & (POLLIN | POLLRDNORM); 1022 } else { 1023 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1024 selrecord(l, &tp->tun_rsel); 1025 } 1026 } 1027 1028 if (events & (POLLOUT | POLLWRNORM)) 1029 revents |= events & (POLLOUT | POLLWRNORM); 1030 1031 mutex_exit(&tp->tun_lock); 1032 out_nolock: 1033 splx(s); 1034 return (revents); 1035 } 1036 1037 static void 1038 filt_tunrdetach(struct knote *kn) 1039 { 1040 struct tun_softc *tp = kn->kn_hook; 1041 int s; 1042 1043 s = splnet(); 1044 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1045 splx(s); 1046 } 1047 1048 static int 1049 filt_tunread(struct knote *kn, long hint) 1050 { 1051 struct tun_softc *tp = kn->kn_hook; 1052 struct ifnet *ifp = &tp->tun_if; 1053 struct mbuf *m; 1054 int s; 1055 1056 s = splnet(); 1057 IF_POLL(&ifp->if_snd, m); 1058 if (m == NULL) { 1059 splx(s); 1060 return (0); 1061 } 1062 1063 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1064 kn->kn_data += m->m_len; 1065 1066 splx(s); 1067 return (1); 1068 } 1069 1070 static const struct filterops tunread_filtops = 1071 { 1, NULL, filt_tunrdetach, filt_tunread }; 1072 1073 static const struct filterops tun_seltrue_filtops = 1074 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1075 1076 int 1077 tunkqfilter(dev_t dev, struct knote *kn) 1078 { 1079 struct tun_softc *tp; 1080 struct klist *klist; 1081 int rv = 0, s; 1082 1083 s = splnet(); 1084 tp = tun_find_unit(dev); 1085 if (tp == NULL) 1086 goto out_nolock; 1087 1088 switch (kn->kn_filter) { 1089 case EVFILT_READ: 1090 klist = &tp->tun_rsel.sel_klist; 1091 kn->kn_fop = &tunread_filtops; 1092 break; 1093 1094 case EVFILT_WRITE: 1095 klist = &tp->tun_rsel.sel_klist; 1096 kn->kn_fop = &tun_seltrue_filtops; 1097 break; 1098 1099 default: 1100 rv = EINVAL; 1101 goto out; 1102 } 1103 1104 kn->kn_hook = tp; 1105 1106 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1107 1108 out: 1109 mutex_exit(&tp->tun_lock); 1110 out_nolock: 1111 splx(s); 1112 return (rv); 1113 } 1114
Indexes created Thu Oct 16 14:10:15 GMT 2025