if_tun.c revision 1.86
1 /* $NetBSD: if_tun.c,v 1.86 2006/04/04 15:43:23 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 1.86 2006/04/04 15:43:23 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 else 650 tp->tun_flags &= ~TUN_PREPADDR; 651 break; 652 653 case TUNSIFHEAD: 654 if (*(int *)data) 655 tp->tun_flags |= TUN_IFHEAD; 656 else 657 tp->tun_flags &= ~TUN_IFHEAD; 658 break; 659 660 case TUNGIFHEAD: 661 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 662 break; 663 664 case FIONBIO: 665 if (*(int *)data) 666 tp->tun_flags |= TUN_NBIO; 667 else 668 tp->tun_flags &= ~TUN_NBIO; 669 break; 670 671 case FIOASYNC: 672 if (*(int *)data) 673 tp->tun_flags |= TUN_ASYNC; 674 else 675 tp->tun_flags &= ~TUN_ASYNC; 676 break; 677 678 case FIONREAD: 679 if (tp->tun_if.if_snd.ifq_head) 680 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 681 else 682 *(int *)data = 0; 683 break; 684 685 case TIOCSPGRP: 686 case FIOSETOWN: 687 error = fsetown(l->l_proc, &tp->tun_pgid, cmd, data); 688 break; 689 690 case TIOCGPGRP: 691 case FIOGETOWN: 692 error = fgetown(l->l_proc, tp->tun_pgid, cmd, data); 693 break; 694 695 default: 696 error = ENOTTY; 697 } 698 699 out: 700 simple_unlock(&tp->tun_lock); 701 out_nolock: 702 splx(s); 703 return (error); 704 } 705 706 /* 707 * The cdevsw read interface - reads a packet at a time, or at 708 * least as much of a packet as can be read. 709 */ 710 int 711 tunread(dev_t dev, struct uio *uio, int ioflag) 712 { 713 struct tun_softc *tp; 714 struct ifnet *ifp; 715 struct mbuf *m, *m0; 716 int error = 0, len, s, index; 717 718 s = splnet(); 719 tp = tun_find_unit(dev); 720 721 /* interface was "destroyed" already */ 722 if (tp == NULL) { 723 error = ENXIO; 724 goto out_nolock; 725 } 726 727 index = tp->tun_if.if_index; 728 ifp = &tp->tun_if; 729 730 TUNDEBUG ("%s: read\n", ifp->if_xname); 731 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 732 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 733 error = EHOSTDOWN; 734 goto out; 735 } 736 737 tp->tun_flags &= ~TUN_RWAIT; 738 739 do { 740 IFQ_DEQUEUE(&ifp->if_snd, m0); 741 if (m0 == 0) { 742 if (tp->tun_flags & TUN_NBIO) { 743 error = EWOULDBLOCK; 744 goto out; 745 } 746 tp->tun_flags |= TUN_RWAIT; 747 if (ltsleep((caddr_t)tp, PZERO|PCATCH|PNORELOCK, 748 "tunread", 0, &tp->tun_lock) != 0) { 749 error = EINTR; 750 goto out_nolock; 751 } else { 752 /* 753 * Maybe the interface was destroyed while 754 * we were sleeping, so let's ensure that 755 * we're looking at the same (valid) tun 756 * interface before looping. 757 */ 758 tp = tun_find_unit(dev); 759 if (tp == NULL) { 760 error = ENXIO; 761 goto out_nolock; 762 } 763 if (tp->tun_if.if_index != index) { 764 error = ENXIO; 765 goto out; 766 } 767 } 768 } 769 } while (m0 == 0); 770 771 simple_unlock(&tp->tun_lock); 772 splx(s); 773 774 /* Copy the mbuf chain */ 775 while (m0 && uio->uio_resid > 0 && error == 0) { 776 len = min(uio->uio_resid, m0->m_len); 777 if (len != 0) 778 error = uiomove(mtod(m0, caddr_t), len, uio); 779 MFREE(m0, m); 780 m0 = m; 781 } 782 783 if (m0) { 784 TUNDEBUG("Dropping mbuf\n"); 785 m_freem(m0); 786 } 787 if (error) 788 ifp->if_ierrors++; 789 790 return (error); 791 792 out: 793 simple_unlock(&tp->tun_lock); 794 out_nolock: 795 splx(s); 796 return (error); 797 } 798 799 /* 800 * the cdevsw write interface - an atomic write is a packet - or else! 801 */ 802 int 803 tunwrite(dev_t dev, struct uio *uio, int ioflag) 804 { 805 struct tun_softc *tp; 806 struct ifnet *ifp; 807 struct mbuf *top, **mp, *m; 808 struct ifqueue *ifq; 809 struct sockaddr dst; 810 int isr, error = 0, s, tlen, mlen; 811 uint32_t family; 812 813 s = splnet(); 814 tp = tun_find_unit(dev); 815 816 /* interface was "destroyed" already */ 817 if (tp == NULL) { 818 error = ENXIO; 819 goto out_nolock; 820 } 821 822 /* Unlock until we've got the data */ 823 simple_unlock(&tp->tun_lock); 824 splx(s); 825 826 ifp = &tp->tun_if; 827 828 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 829 830 if (tp->tun_flags & TUN_PREPADDR) { 831 if (uio->uio_resid < sizeof(dst)) { 832 error = EIO; 833 goto out0; 834 } 835 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 836 if (dst.sa_len > sizeof(dst)) { 837 /* Duh.. */ 838 char discard; 839 int n = dst.sa_len - sizeof(dst); 840 while (n--) 841 if ((error = uiomove(&discard, 1, uio)) != 0) { 842 goto out0; 843 } 844 } 845 } else if (tp->tun_flags & TUN_IFHEAD) { 846 if (uio->uio_resid < sizeof(family)){ 847 error = EIO; 848 goto out0; 849 } 850 error = uiomove((caddr_t)&family, sizeof(family), uio); 851 dst.sa_family = ntohl(family); 852 } else { 853 #ifdef INET 854 dst.sa_family = AF_INET; 855 #endif 856 } 857 858 if (uio->uio_resid > TUNMTU) { 859 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 860 (unsigned long)uio->uio_resid); 861 error = EIO; 862 goto out0; 863 } 864 865 switch (dst.sa_family) { 866 #ifdef INET 867 case AF_INET: 868 ifq = &ipintrq; 869 isr = NETISR_IP; 870 break; 871 #endif 872 #ifdef INET6 873 case AF_INET6: 874 ifq = &ip6intrq; 875 isr = NETISR_IPV6; 876 break; 877 #endif 878 default: 879 error = EAFNOSUPPORT; 880 goto out0; 881 } 882 883 tlen = uio->uio_resid; 884 885 /* get a header mbuf */ 886 MGETHDR(m, M_DONTWAIT, MT_DATA); 887 if (m == NULL) { 888 error = ENOBUFS; 889 goto out0; 890 } 891 mlen = MHLEN; 892 893 top = NULL; 894 mp = ⊤ 895 while (error == 0 && uio->uio_resid > 0) { 896 m->m_len = min(mlen, uio->uio_resid); 897 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 898 *mp = m; 899 mp = &m->m_next; 900 if (error == 0 && uio->uio_resid > 0) { 901 MGET(m, M_DONTWAIT, MT_DATA); 902 if (m == NULL) { 903 error = ENOBUFS; 904 break; 905 } 906 mlen = MLEN; 907 } 908 } 909 if (error) { 910 if (top != NULL) 911 m_freem (top); 912 ifp->if_ierrors++; 913 goto out0; 914 } 915 916 top->m_pkthdr.len = tlen; 917 top->m_pkthdr.rcvif = ifp; 918 919 #if NBPFILTER > 0 920 if (ifp->if_bpf) 921 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 922 #endif 923 924 s = splnet(); 925 simple_lock(&tp->tun_lock); 926 if ((tp->tun_flags & TUN_INITED) == 0) { 927 /* Interface was destroyed */ 928 error = ENXIO; 929 goto out; 930 } 931 if (IF_QFULL(ifq)) { 932 IF_DROP(ifq); 933 ifp->if_collisions++; 934 m_freem(top); 935 error = ENOBUFS; 936 goto out; 937 } 938 939 IF_ENQUEUE(ifq, top); 940 ifp->if_ipackets++; 941 ifp->if_ibytes += tlen; 942 schednetisr(isr); 943 out: 944 simple_unlock(&tp->tun_lock); 945 out_nolock: 946 splx(s); 947 out0: 948 return (error); 949 } 950 951 #ifdef ALTQ 952 /* 953 * Start packet transmission on the interface. 954 * when the interface queue is rate-limited by ALTQ or TBR, 955 * if_start is needed to drain packets from the queue in order 956 * to notify readers when outgoing packets become ready. 957 * 958 * Should be called at splnet. 959 */ 960 static void 961 tunstart(struct ifnet *ifp) 962 { 963 struct tun_softc *tp = ifp->if_softc; 964 965 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 966 return; 967 968 simple_lock(&tp->tun_lock); 969 if (!IF_IS_EMPTY(&ifp->if_snd)) { 970 if (tp->tun_flags & TUN_RWAIT) { 971 tp->tun_flags &= ~TUN_RWAIT; 972 wakeup((caddr_t)tp); 973 } 974 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 975 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 976 POLLOUT|POLLWRNORM, NULL); 977 978 selwakeup(&tp->tun_rsel); 979 } 980 simple_unlock(&tp->tun_lock); 981 } 982 #endif /* ALTQ */ 983 /* 984 * tunpoll - the poll interface, this is only useful on reads 985 * really. The write detect always returns true, write never blocks 986 * anyway, it either accepts the packet or drops it. 987 */ 988 int 989 tunpoll(dev_t dev, int events, struct lwp *l) 990 { 991 struct tun_softc *tp; 992 struct ifnet *ifp; 993 int s, revents = 0; 994 995 s = splnet(); 996 tp = tun_find_unit(dev); 997 998 /* interface was "destroyed" already */ 999 if (tp == NULL) 1000 goto out_nolock; 1001 1002 ifp = &tp->tun_if; 1003 1004 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 1005 1006 if (events & (POLLIN | POLLRDNORM)) { 1007 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 1008 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1009 ifp->if_snd.ifq_len); 1010 revents |= events & (POLLIN | POLLRDNORM); 1011 } else { 1012 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1013 selrecord(l, &tp->tun_rsel); 1014 } 1015 } 1016 1017 if (events & (POLLOUT | POLLWRNORM)) 1018 revents |= events & (POLLOUT | POLLWRNORM); 1019 1020 simple_unlock(&tp->tun_lock); 1021 out_nolock: 1022 splx(s); 1023 return (revents); 1024 } 1025 1026 static void 1027 filt_tunrdetach(struct knote *kn) 1028 { 1029 struct tun_softc *tp = kn->kn_hook; 1030 int s; 1031 1032 s = splnet(); 1033 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1034 splx(s); 1035 } 1036 1037 static int 1038 filt_tunread(struct knote *kn, long hint) 1039 { 1040 struct tun_softc *tp = kn->kn_hook; 1041 struct ifnet *ifp = &tp->tun_if; 1042 struct mbuf *m; 1043 int s; 1044 1045 s = splnet(); 1046 IF_POLL(&ifp->if_snd, m); 1047 if (m == NULL) { 1048 splx(s); 1049 return (0); 1050 } 1051 1052 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1053 kn->kn_data += m->m_len; 1054 1055 splx(s); 1056 return (1); 1057 } 1058 1059 static const struct filterops tunread_filtops = 1060 { 1, NULL, filt_tunrdetach, filt_tunread }; 1061 1062 static const struct filterops tun_seltrue_filtops = 1063 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1064 1065 int 1066 tunkqfilter(dev_t dev, struct knote *kn) 1067 { 1068 struct tun_softc *tp; 1069 struct klist *klist; 1070 int rv = 0, s; 1071 1072 s = splnet(); 1073 tp = tun_find_unit(dev); 1074 if (tp == NULL) 1075 goto out_nolock; 1076 1077 switch (kn->kn_filter) { 1078 case EVFILT_READ: 1079 klist = &tp->tun_rsel.sel_klist; 1080 kn->kn_fop = &tunread_filtops; 1081 break; 1082 1083 case EVFILT_WRITE: 1084 klist = &tp->tun_rsel.sel_klist; 1085 kn->kn_fop = &tun_seltrue_filtops; 1086 break; 1087 1088 default: 1089 rv = 1; 1090 goto out; 1091 } 1092 1093 kn->kn_hook = tp; 1094 1095 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1096 1097 out: 1098 simple_unlock(&tp->tun_lock); 1099 out_nolock: 1100 splx(s); 1101 return (rv); 1102 } 1103
Indexes created Fri Sep 26 08:10:20 GMT 2025