if_tun.c revision 1.115.10.2
1 /* $NetBSD: if_tun.c,v 1.115.10.2 2014/05/18 17:46:12 rmind 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 /* 18 * tun - tunnel software network interface. 19 */ 20 21 #include <sys/cdefs.h> 22 __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.115.10.2 2014/05/18 17:46:12 rmind Exp $"); 23 24 #include "opt_inet.h" 25 26 #include <sys/param.h> 27 28 #include <sys/systm.h> 29 #include <sys/mbuf.h> 30 #include <sys/protosw.h> 31 #include <sys/socket.h> 32 #include <sys/ioctl.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 #include <sys/kauth.h> 39 #include <sys/lwp.h> 40 #include <sys/kmem.h> 41 #include <sys/mutex.h> 42 43 #include <net/if.h> 44 #include <net/if_types.h> 45 #include <net/netisr.h> 46 #include <net/route.h> 47 48 #ifdef INET 49 #include <netinet/in.h> 50 #include <netinet/in_systm.h> 51 #include <netinet/in_var.h> 52 #include <netinet/ip.h> 53 #include <netinet/if_inarp.h> 54 #endif 55 56 #include <net/bpf.h> 57 58 #include <net/if_tun.h> 59 60 /* Tunnel structure. */ 61 typedef struct tun_softc { 62 LIST_ENTRY(tun_softc) tun_list; /* list of all tuns */ 63 kmutex_t tun_lock; /* lock for this tunnel */ 64 kcondvar_t tun_cv; /* condition variable for tunnel */ 65 ifnet_t tun_if; /* the interface */ 66 u_short tun_flags; /* misc flags */ 67 pid_t tun_pgid; /* PID or process group ID */ 68 struct selinfo tun_rsel; /* read select */ 69 struct selinfo tun_wsel; /* write select (not used) */ 70 int tun_unit; /* the tunnel unit number */ 71 void * tun_osih; /* soft interrupt handle */ 72 void * tun_isih; /* soft interrupt handle */ 73 } tun_softc_t; 74 75 /* Flags. */ 76 #define TUN_OPEN 0x0001 77 #define TUN_INITED 0x0002 78 #define TUN_RCOLL 0x0004 79 #define TUN_IASET 0x0008 80 #define TUN_DSTADDR 0x0010 81 #define TUN_RWAIT 0x0040 82 #define TUN_ASYNC 0x0080 83 #define TUN_NBIO 0x0100 84 #define TUN_PREPADDR 0x0200 85 #define TUN_IFHEAD 0x0400 86 #define TUN_READY (TUN_OPEN | TUN_INITED | TUN_IASET) 87 88 static LIST_HEAD(, tun_softc) tun_softc_list; 89 static LIST_HEAD(, tun_softc) tunz_softc_list; 90 static kmutex_t tun_softc_lock; 91 92 #define TUNDEBUG if (tundebug) printf 93 int tundebug = 0; 94 95 extern int ifqmaxlen; 96 97 static LIST_HEAD(, tun_softc) tun_softc_list; 98 static LIST_HEAD(, tun_softc) tunz_softc_list; 99 static kmutex_t tun_softc_lock; 100 101 static int tun_ioctl(struct ifnet *, u_long, void *); 102 static int tun_output(struct ifnet *, struct mbuf *, 103 const struct sockaddr *, struct rtentry *rt); 104 static int tun_clone_create(struct if_clone *, int); 105 static int tun_clone_destroy(ifnet_t *); 106 107 static void tunattach0(tun_softc_t *); 108 static void tuninit(tun_softc_t *); 109 static void tun_i_softintr(void *); 110 static void tun_o_softintr(void *); 111 #ifdef ALTQ 112 static void tunstart(ifnet_t *); 113 #endif 114 static tun_softc_t *tun_find_unit(dev_t); 115 static tun_softc_t *tun_find_zunit(int); 116 117 static dev_type_open(tunopen); 118 static dev_type_close(tunclose); 119 static dev_type_read(tunread); 120 static dev_type_write(tunwrite); 121 static dev_type_ioctl(tunioctl); 122 static dev_type_poll(tunpoll); 123 static dev_type_kqfilter(tunkqfilter); 124 125 static struct if_clone tun_cloner = 126 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 127 128 const struct cdevsw tun_cdevsw = { 129 .d_open = tunopen, 130 .d_close = tunclose, 131 .d_read = tunread, 132 .d_write = tunwrite, 133 .d_ioctl = tunioctl, 134 .d_stop = nostop, 135 .d_tty = notty, 136 .d_poll = tunpoll, 137 .d_mmap = nommap, 138 .d_kqfilter = tunkqfilter, 139 .d_flag = D_OTHER | D_MPSAFE 140 }; 141 142 void 143 tunattach(int unused) 144 { 145 mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NET); 146 LIST_INIT(&tun_softc_list); 147 LIST_INIT(&tunz_softc_list); 148 if_clone_attach(&tun_cloner); 149 } 150 151 /* 152 * tun_find_unit: find driver instance from dev_t. 153 * 154 * => Returns tun locked, if found. 155 */ 156 static struct tun_softc * 157 tun_find_unit(dev_t dev) 158 { 159 tun_softc_t *tp; 160 int unit = minor(dev); 161 162 mutex_enter(&tun_softc_lock); 163 LIST_FOREACH(tp, &tun_softc_list, tun_list) { 164 if (unit == tp->tun_unit) { 165 mutex_enter(&tp->tun_lock); 166 break; 167 } 168 } 169 mutex_exit(&tun_softc_lock); 170 return tp; 171 } 172 173 /* 174 * tun_find_zunit: find zombie driver instance by unit number. 175 */ 176 static struct tun_softc * 177 tun_find_zunit(int unit) 178 { 179 tun_softc_t *tp; 180 181 mutex_enter(&tun_softc_lock); 182 LIST_FOREACH(tp, &tunz_softc_list, tun_list) { 183 if (unit == tp->tun_unit) { 184 LIST_REMOVE(tp, tun_list); 185 break; 186 } 187 } 188 mutex_exit(&tun_softc_lock); 189 190 KASSERT(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN); 191 return tp; 192 } 193 194 static int 195 tun_clone_create(struct if_clone *ifc, int unit) 196 { 197 tun_softc_t *tp; 198 199 if ((tp = tun_find_zunit(unit)) == NULL) { 200 tp = kmem_zalloc(sizeof(*tp), KM_SLEEP); 201 202 tp->tun_unit = unit; 203 mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_NET); 204 cv_init(&tp->tun_cv, "tunread"); 205 selinit(&tp->tun_rsel); 206 selinit(&tp->tun_wsel); 207 } else { 208 /* Revive tunnel instance; clear ifp part. */ 209 memset(&tp->tun_if, 0, sizeof(ifnet_t)); 210 } 211 212 if_initname(&tp->tun_if, ifc->ifc_name, unit); 213 tunattach0(tp); 214 tp->tun_flags |= TUN_INITED; 215 tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); 216 tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); 217 218 mutex_enter(&tun_softc_lock); 219 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 220 mutex_exit(&tun_softc_lock); 221 222 return 0; 223 } 224 225 static void 226 tunattach0(tun_softc_t *tp) 227 { 228 ifnet_t *ifp; 229 230 ifp = &tp->tun_if; 231 ifp->if_softc = tp; 232 ifp->if_mtu = TUNMTU; 233 ifp->if_ioctl = tun_ioctl; 234 ifp->if_output = tun_output; 235 #ifdef ALTQ 236 ifp->if_start = tunstart; 237 #endif 238 ifp->if_flags = IFF_POINTOPOINT; 239 ifp->if_type = IFT_TUNNEL; 240 ifp->if_snd.ifq_maxlen = ifqmaxlen; 241 ifp->if_collisions = 0; 242 ifp->if_ierrors = 0; 243 ifp->if_oerrors = 0; 244 ifp->if_ipackets = 0; 245 ifp->if_opackets = 0; 246 ifp->if_ibytes = 0; 247 ifp->if_obytes = 0; 248 ifp->if_dlt = DLT_NULL; 249 IFQ_SET_READY(&ifp->if_snd); 250 if_attach(ifp); 251 if_alloc_sadl(ifp); 252 bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); 253 } 254 255 static int 256 tun_clone_destroy(ifnet_t *ifp) 257 { 258 tun_softc_t *tp = (void *)ifp; 259 bool zombie = false; 260 261 IF_PURGE(&ifp->if_snd); 262 ifp->if_flags &= ~IFF_RUNNING; 263 264 mutex_enter(&tun_softc_lock); 265 mutex_enter(&tp->tun_lock); 266 LIST_REMOVE(tp, tun_list); 267 if (tp->tun_flags & TUN_OPEN) { 268 /* Hang on to storage until last close. */ 269 tp->tun_flags &= ~TUN_INITED; 270 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 271 zombie = true; 272 } 273 mutex_exit(&tun_softc_lock); 274 275 if (tp->tun_flags & TUN_RWAIT) { 276 tp->tun_flags &= ~TUN_RWAIT; 277 cv_broadcast(&tp->tun_cv); 278 } 279 selnotify(&tp->tun_rsel, 0, 0); 280 mutex_exit(&tp->tun_lock); 281 282 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) { 283 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 284 } 285 286 bpf_detach(ifp); 287 if_detach(ifp); 288 289 if (!zombie) { 290 seldestroy(&tp->tun_rsel); 291 seldestroy(&tp->tun_wsel); 292 softint_disestablish(tp->tun_osih); 293 softint_disestablish(tp->tun_isih); 294 mutex_destroy(&tp->tun_lock); 295 kmem_free(tp, sizeof(*tp)); 296 } 297 return 0; 298 } 299 300 /* 301 * tunopen: tunnel open (must be superuser & the device must be configured). 302 */ 303 static int 304 tunopen(dev_t dev, int flag, int mode, lwp_t *l) 305 { 306 ifnet_t *ifp; 307 tun_softc_t *tp; 308 int error; 309 310 error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, 311 KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); 312 if (error) 313 return error; 314 315 if ((tp = tun_find_unit(dev)) == NULL) { 316 (void)tun_clone_create(&tun_cloner, minor(dev)); 317 tp = tun_find_unit(dev); 318 if (tp == NULL) { 319 return ENXIO; 320 } 321 } 322 if (tp->tun_flags & TUN_OPEN) { 323 mutex_exit(&tp->tun_lock); 324 return EBUSY; 325 } 326 ifp = &tp->tun_if; 327 tp->tun_flags |= TUN_OPEN; 328 mutex_exit(&tp->tun_lock); 329 330 return error; 331 } 332 333 /* 334 * tunclose: close the device - mark i/f down & delete routing info. 335 */ 336 int 337 tunclose(dev_t dev, int flag, int mode, lwp_t *l) 338 { 339 tun_softc_t *tp; 340 ifnet_t *ifp; 341 342 tp = tun_find_zunit(minor(dev)); 343 if (tp) { 344 /* Interface was "destroyed" before the close. */ 345 seldestroy(&tp->tun_rsel); 346 seldestroy(&tp->tun_wsel); 347 softint_disestablish(tp->tun_osih); 348 softint_disestablish(tp->tun_isih); 349 mutex_destroy(&tp->tun_lock); 350 kmem_free(tp, sizeof(*tp)); 351 return 0; 352 } 353 354 tp = tun_find_unit(dev); 355 if (tp == NULL) { 356 return 0; 357 } 358 ifp = &tp->tun_if; 359 tp->tun_flags &= ~TUN_OPEN; 360 tp->tun_pgid = 0; 361 selnotify(&tp->tun_rsel, 0, 0); 362 mutex_exit(&tp->tun_lock); 363 364 /* Junk all pending output. */ 365 IFQ_PURGE(&ifp->if_snd); 366 367 if (ifp->if_flags & IFF_UP) { 368 if_down(ifp); 369 if (ifp->if_flags & IFF_RUNNING) { 370 /* Find internet addresses and delete routes. */ 371 struct ifaddr *ifa; 372 IFADDR_FOREACH(ifa, ifp) { 373 #if defined(INET) || defined(INET6) 374 if (ifa->ifa_addr->sa_family != AF_INET && 375 ifa->ifa_addr->sa_family != AF_INET6) { 376 continue; 377 } 378 rtinit(ifa, (int)RTM_DELETE, 379 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0); 380 #endif 381 } 382 } 383 } 384 return 0; 385 } 386 387 static void 388 tuninit(tun_softc_t *tp) 389 { 390 ifnet_t *ifp = &tp->tun_if; 391 struct ifaddr *ifa; 392 393 mutex_enter(&tp->tun_lock); 394 ifp->if_flags |= IFF_UP | IFF_RUNNING; 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 #ifdef INET6 413 if (ifa->ifa_addr->sa_family == AF_INET6) { 414 struct sockaddr_in6 *sin; 415 416 sin = (struct sockaddr_in6 *)ifa->ifa_addr; 417 if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 418 tp->tun_flags |= TUN_IASET; 419 420 if (ifp->if_flags & IFF_POINTOPOINT) { 421 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr; 422 if (sin && 423 !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) 424 tp->tun_flags |= TUN_DSTADDR; 425 } else 426 tp->tun_flags &= ~TUN_DSTADDR; 427 } 428 #endif /* INET6 */ 429 } 430 mutex_exit(&tp->tun_lock); 431 } 432 433 /* 434 * Process an ioctl request. 435 */ 436 static int 437 tun_ioctl(ifnet_t *ifp, u_long cmd, void *data) 438 { 439 tun_softc_t *tp = ifp->if_softc; 440 struct ifreq *ifr = data; 441 int error = 0; 442 443 switch (cmd) { 444 case SIOCINITIFADDR: 445 tuninit(tp); 446 break; 447 case SIOCSIFBRDADDR: 448 break; 449 case SIOCSIFMTU: 450 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 451 error = EINVAL; 452 break; 453 } 454 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 455 error = 0; 456 break; 457 case SIOCADDMULTI: 458 case SIOCDELMULTI: 459 if (ifr == NULL) { 460 error = EAFNOSUPPORT; /* XXX */ 461 break; 462 } 463 switch (ifreq_getaddr(cmd, ifr)->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 default: 478 error = ifioctl_common(ifp, cmd, data); 479 } 480 return error; 481 } 482 483 /* 484 * tun_output - queue packets from higher level ready to put out. 485 */ 486 static int 487 tun_output(ifnet_t *ifp, struct mbuf *m0, const struct sockaddr *dst, 488 struct rtentry *rt) 489 { 490 tun_softc_t *tp = ifp->if_softc; 491 int error = 0; 492 493 ALTQ_DECL(struct altq_pktattr pktattr;) 494 495 mutex_enter(&tp->tun_lock); 496 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 497 error = EHOSTDOWN; 498 goto out; 499 } 500 // XXXrmind 501 mutex_exit(&tp->tun_lock); 502 503 /* 504 * If the queueing discipline needs packet classification, 505 * do it before prepending link headers. 506 */ 507 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 508 bpf_mtap_af(ifp, dst->sa_family, m0); 509 510 switch(dst->sa_family) { 511 #ifdef INET6 512 case AF_INET6: 513 #endif 514 #ifdef INET 515 case AF_INET: 516 #endif 517 #if defined(INET) || defined(INET6) 518 if (tp->tun_flags & TUN_PREPADDR) { 519 /* Simple link-layer header */ 520 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 521 if (m0 == NULL) { 522 IF_DROP(&ifp->if_snd); 523 error = ENOBUFS; 524 goto out; 525 } 526 memcpy(mtod(m0, char *), dst, dst->sa_len); 527 } 528 529 if (tp->tun_flags & TUN_IFHEAD) { 530 uint32_t *af; 531 532 /* Prepend the address family */ 533 M_PREPEND(m0, sizeof(*af), M_DONTWAIT); 534 if (m0 == NULL) { 535 IF_DROP(&ifp->if_snd); 536 error = ENOBUFS; 537 goto out; 538 } 539 af = mtod(m0,uint32_t *); 540 *af = htonl(dst->sa_family); 541 } else { 542 #ifdef INET 543 if (dst->sa_family != AF_INET) 544 #endif 545 { 546 error = EAFNOSUPPORT; 547 goto out; 548 } 549 } 550 /* FALLTHROUGH */ 551 case AF_UNSPEC: 552 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 553 if (error) { 554 ifp->if_collisions++; 555 error = EAFNOSUPPORT; 556 m0 = NULL; 557 goto out; 558 } 559 ifp->if_obytes += m0->m_pkthdr.len; 560 ifp->if_opackets++; 561 break; 562 #endif 563 default: 564 error = EAFNOSUPPORT; 565 goto out; 566 } 567 568 mutex_enter(&tp->tun_lock); 569 if (tp->tun_flags & TUN_RWAIT) { 570 tp->tun_flags &= ~TUN_RWAIT; 571 cv_broadcast(&tp->tun_cv); 572 } 573 if ((tp->tun_flags & TUN_ASYNC) != 0 && tp->tun_pgid) { 574 softint_schedule(tp->tun_isih); 575 } 576 selnotify(&tp->tun_rsel, 0, 0); 577 mutex_exit(&tp->tun_lock); 578 out: 579 if (error && m0) { 580 m_freem(m0); 581 } 582 return 0; 583 } 584 585 static void 586 tun_i_softintr(void *cookie) 587 { 588 tun_softc_t *tp = cookie; 589 590 if ((tp->tun_flags & TUN_ASYNC) == 0 || tp->tun_pgid == 0) { 591 return; 592 } 593 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN | POLLRDNORM, NULL); 594 } 595 596 static void 597 tun_o_softintr(void *cookie) 598 { 599 tun_softc_t *tp = cookie; 600 601 if ((tp->tun_flags & TUN_ASYNC) == 0 || tp->tun_pgid == 0) { 602 return; 603 } 604 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT | POLLWRNORM, NULL); 605 } 606 607 /* 608 * the cdevsw interface is now pretty minimal. 609 */ 610 int 611 tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 612 { 613 struct tun_softc *tp; 614 int error = 0; 615 616 tp = tun_find_unit(dev); 617 if (tp == NULL) { 618 /* Interface was "destroyed" already. */ 619 return ENXIO; 620 } 621 switch (cmd) { 622 case TUNSDEBUG: 623 tundebug = *(int *)data; 624 break; 625 626 case TUNGDEBUG: 627 *(int *)data = tundebug; 628 break; 629 630 case TUNSIFMODE: 631 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 632 case IFF_POINTOPOINT: 633 case IFF_BROADCAST: 634 if (tp->tun_if.if_flags & IFF_UP) { 635 error = EBUSY; 636 goto out; 637 } 638 tp->tun_if.if_flags &= 639 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 640 tp->tun_if.if_flags |= *(int *)data; 641 break; 642 default: 643 error = EINVAL; 644 goto out; 645 } 646 break; 647 648 case TUNSLMODE: 649 if (*(int *)data) { 650 tp->tun_flags |= TUN_PREPADDR; 651 tp->tun_flags &= ~TUN_IFHEAD; 652 } else 653 tp->tun_flags &= ~TUN_PREPADDR; 654 break; 655 656 case TUNSIFHEAD: 657 if (*(int *)data) { 658 tp->tun_flags |= TUN_IFHEAD; 659 tp->tun_flags &= ~TUN_PREPADDR; 660 } else 661 tp->tun_flags &= ~TUN_IFHEAD; 662 break; 663 664 case TUNGIFHEAD: 665 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 666 break; 667 668 case FIONBIO: 669 if (*(int *)data) 670 tp->tun_flags |= TUN_NBIO; 671 else 672 tp->tun_flags &= ~TUN_NBIO; 673 break; 674 675 case FIOASYNC: 676 if (*(int *)data) 677 tp->tun_flags |= TUN_ASYNC; 678 else 679 tp->tun_flags &= ~TUN_ASYNC; 680 break; 681 682 case FIONREAD: 683 if (tp->tun_if.if_snd.ifq_head) 684 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 685 else 686 *(int *)data = 0; 687 break; 688 689 case TIOCSPGRP: 690 case FIOSETOWN: 691 error = fsetown(&tp->tun_pgid, cmd, data); 692 break; 693 694 case TIOCGPGRP: 695 case FIOGETOWN: 696 error = fgetown(tp->tun_pgid, cmd, data); 697 break; 698 699 default: 700 error = ENOTTY; 701 } 702 703 out: 704 mutex_exit(&tp->tun_lock); 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 tun_softc_t *tp; 716 ifnet_t *ifp; 717 struct mbuf *m; 718 int error = 0, index; 719 720 tp = tun_find_unit(dev); 721 if (tp == NULL) { 722 /* Interface was "destroyed" already. */ 723 return ENXIO; 724 } 725 index = tp->tun_if.if_index; 726 ifp = &tp->tun_if; 727 728 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 729 error = EHOSTDOWN; 730 goto out; 731 } 732 tp->tun_flags &= ~TUN_RWAIT; 733 734 do { 735 IFQ_DEQUEUE(&ifp->if_snd, m); 736 if (m != NULL) { 737 break; 738 } 739 if (tp->tun_flags & TUN_NBIO) { 740 error = EWOULDBLOCK; 741 goto out; 742 } 743 tp->tun_flags |= TUN_RWAIT; 744 if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { 745 mutex_exit(&tp->tun_lock); 746 error = EINTR; 747 goto out; 748 } 749 } while (m == NULL); 750 751 mutex_exit(&tp->tun_lock); 752 753 /* Copy the mbuf chain. */ 754 while (m && uio->uio_resid > 0 && error == 0) { 755 size_t len = MIN(uio->uio_resid, m->m_len); 756 if (len) { 757 error = uiomove(mtod(m, void *), len, uio); 758 } 759 m = m_free(m); 760 } 761 if (m) { 762 m_freem(m); 763 } 764 if (error) { 765 ifp->if_ierrors++; 766 } 767 return error; 768 769 out: 770 mutex_exit(&tp->tun_lock); 771 return error; 772 } 773 774 /* 775 * the cdevsw write interface - an atomic write is a packet - or else! 776 */ 777 int 778 tunwrite(dev_t dev, struct uio *uio, int ioflag) 779 { 780 tun_softc_t *tp; 781 ifnet_t *ifp; 782 struct mbuf *top, **mp, *m; 783 struct ifqueue *ifq; 784 struct sockaddr dst; 785 int isr, error = 0, tlen, mlen; 786 uint32_t family; 787 788 tp = tun_find_unit(dev); 789 if (tp == NULL) { 790 /* Interface was "destroyed" already. */ 791 return ENXIO; 792 } 793 /* Unlock until we've got the data. */ 794 mutex_exit(&tp->tun_lock); 795 796 ifp = &tp->tun_if; 797 798 if (tp->tun_flags & TUN_PREPADDR) { 799 if (uio->uio_resid < sizeof(dst)) { 800 error = EIO; 801 goto out0; 802 } 803 error = uiomove((void *)&dst, sizeof(dst), uio); 804 if (dst.sa_len > sizeof(dst)) { 805 /* Duh.. */ 806 int n = dst.sa_len - sizeof(dst); 807 while (n--) { 808 char discard; 809 error = uiomove(&discard, 1, uio); 810 if (error) { 811 goto out0; 812 } 813 } 814 } 815 } else if (tp->tun_flags & TUN_IFHEAD) { 816 if (uio->uio_resid < sizeof(family)){ 817 error = EIO; 818 goto out0; 819 } 820 error = uiomove((void *)&family, sizeof(family), uio); 821 dst.sa_family = ntohl(family); 822 } else { 823 #ifdef INET 824 dst.sa_family = AF_INET; 825 #endif 826 } 827 828 if (uio->uio_resid > TUNMTU) { 829 error = EIO; 830 goto out0; 831 } 832 833 switch (dst.sa_family) { 834 #ifdef INET 835 case AF_INET: 836 ifq = &ipintrq; 837 isr = NETISR_IP; 838 break; 839 #endif 840 #ifdef INET6 841 case AF_INET6: 842 ifq = &ip6intrq; 843 isr = NETISR_IPV6; 844 break; 845 #endif 846 default: 847 error = EAFNOSUPPORT; 848 goto out0; 849 } 850 851 tlen = uio->uio_resid; 852 853 /* get a header mbuf */ 854 MGETHDR(m, M_DONTWAIT, MT_DATA); 855 if (m == NULL) { 856 error = ENOBUFS; 857 goto out0; 858 } 859 mlen = MHLEN; 860 861 top = NULL; 862 mp = ⊤ 863 while (error == 0 && uio->uio_resid > 0) { 864 m->m_len = MIN(mlen, uio->uio_resid); 865 error = uiomove(mtod(m, void *), m->m_len, uio); 866 *mp = m; 867 mp = &m->m_next; 868 if (error == 0 && uio->uio_resid > 0) { 869 MGET(m, M_DONTWAIT, MT_DATA); 870 if (m == NULL) { 871 error = ENOBUFS; 872 break; 873 } 874 mlen = MLEN; 875 } 876 } 877 if (error) { 878 if (top != NULL) 879 m_freem (top); 880 ifp->if_ierrors++; 881 goto out0; 882 } 883 884 top->m_pkthdr.len = tlen; 885 top->m_pkthdr.rcvif = ifp; 886 887 bpf_mtap_af(ifp, dst.sa_family, top); 888 889 mutex_enter(&tp->tun_lock); 890 if ((tp->tun_flags & TUN_INITED) == 0) { 891 /* Interface was destroyed. */ 892 error = ENXIO; 893 goto out; 894 } 895 if (IF_QFULL(ifq)) { 896 IF_DROP(ifq); 897 ifp->if_collisions++; 898 mutex_exit(&tp->tun_lock); 899 m_freem(top); 900 error = ENOBUFS; 901 goto out0; 902 } 903 IF_ENQUEUE(ifq, top); 904 ifp->if_ipackets++; 905 ifp->if_ibytes += tlen; 906 schednetisr(isr); 907 out: 908 mutex_exit(&tp->tun_lock); 909 out0: 910 return error; 911 } 912 913 #ifdef ALTQ 914 /* 915 * Start packet transmission on the interface. 916 * when the interface queue is rate-limited by ALTQ or TBR, 917 * if_start is needed to drain packets from the queue in order 918 * to notify readers when outgoing packets become ready. 919 */ 920 static void 921 tunstart(ifnet_t *ifp) 922 { 923 tun_softc_t *tp = ifp->if_softc; 924 925 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 926 return; 927 928 mutex_enter(&tp->tun_lock); 929 if (!IF_IS_EMPTY(&ifp->if_snd)) { 930 if (tp->tun_flags & TUN_RWAIT) { 931 tp->tun_flags &= ~TUN_RWAIT; 932 cv_broadcast(&tp->tun_cv); 933 } 934 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) { 935 softint_schedule(tp->tun_osih); 936 } 937 selnotify(&tp->tun_rsel, 0, 0); 938 } 939 mutex_exit(&tp->tun_lock); 940 } 941 #endif /* ALTQ */ 942 943 /* 944 * tunpoll - the poll interface, this is only useful on reads 945 * really. The write detect always returns true, write never blocks 946 * anyway, it either accepts the packet or drops it. 947 */ 948 int 949 tunpoll(dev_t dev, int events, struct lwp *l) 950 { 951 tun_softc_t *tp; 952 ifnet_t *ifp; 953 int revents = 0; 954 955 tp = tun_find_unit(dev); 956 if (tp == NULL) { 957 /* Interface was "destroyed" already. */ 958 return 0; 959 } 960 ifp = &tp->tun_if; 961 962 if (events & (POLLIN | POLLRDNORM)) { 963 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 964 revents |= events & (POLLIN | POLLRDNORM); 965 } else { 966 selrecord(l, &tp->tun_rsel); 967 } 968 } 969 if (events & (POLLOUT | POLLWRNORM)) { 970 revents |= events & (POLLOUT | POLLWRNORM); 971 } 972 mutex_exit(&tp->tun_lock); 973 974 return revents; 975 } 976 977 static void 978 filt_tunrdetach(struct knote *kn) 979 { 980 tun_softc_t *tp = kn->kn_hook; 981 982 mutex_enter(&tp->tun_lock); 983 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 984 mutex_exit(&tp->tun_lock); 985 } 986 987 static int 988 filt_tunread(struct knote *kn, long hint) 989 { 990 tun_softc_t *tp = kn->kn_hook; 991 ifnet_t *ifp = &tp->tun_if; 992 struct mbuf *m; 993 994 mutex_enter(&tp->tun_lock); 995 IF_POLL(&ifp->if_snd, m); 996 if (m == NULL) { 997 mutex_exit(&tp->tun_lock); 998 return (0); 999 } 1000 for (kn->kn_data = 0; m != NULL; m = m->m_next) { 1001 kn->kn_data += m->m_len; 1002 } 1003 mutex_exit(&tp->tun_lock); 1004 1005 return 1; 1006 } 1007 1008 static const struct filterops tunread_filtops = 1009 { 1, NULL, filt_tunrdetach, filt_tunread }; 1010 1011 static const struct filterops tun_seltrue_filtops = 1012 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1013 1014 int 1015 tunkqfilter(dev_t dev, struct knote *kn) 1016 { 1017 tun_softc_t *tp; 1018 struct klist *klist; 1019 int rv = 0; 1020 1021 tp = tun_find_unit(dev); 1022 if (tp == NULL) { 1023 return 0; 1024 } 1025 1026 switch (kn->kn_filter) { 1027 case EVFILT_READ: 1028 klist = &tp->tun_rsel.sel_klist; 1029 kn->kn_fop = &tunread_filtops; 1030 break; 1031 case EVFILT_WRITE: 1032 klist = &tp->tun_rsel.sel_klist; 1033 kn->kn_fop = &tun_seltrue_filtops; 1034 break; 1035 default: 1036 rv = EINVAL; 1037 goto out; 1038 } 1039 1040 kn->kn_hook = tp; 1041 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1042 out: 1043 mutex_exit(&tp->tun_lock); 1044 return rv; 1045 } 1046
Indexes created Wed Oct 15 16:09:53 GMT 2025