if_tun.c revision 1.85
1 /* $NetBSD: if_tun.c,v 1.85 2006/04/04 11:33:15 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 1.85 2006/04/04 11:33:15 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 } 558 /* FALLTHROUGH */ 559 case AF_UNSPEC: 560 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 561 if (error) { 562 ifp->if_collisions++; 563 error = EAFNOSUPPORT; 564 goto out; 565 } 566 mlen = m0->m_pkthdr.len; 567 ifp->if_opackets++; 568 ifp->if_obytes += mlen; 569 break; 570 #endif 571 default: 572 m_freem(m0); 573 error = EAFNOSUPPORT; 574 goto out; 575 } 576 577 if (tp->tun_flags & TUN_RWAIT) { 578 tp->tun_flags &= ~TUN_RWAIT; 579 wakeup((caddr_t)tp); 580 } 581 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 582 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 583 NULL); 584 585 selnotify(&tp->tun_rsel, 0); 586 out: 587 simple_unlock(&tp->tun_lock); 588 splx(s); 589 return (0); 590 } 591 592 /* 593 * the cdevsw interface is now pretty minimal. 594 */ 595 int 596 tunioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l) 597 { 598 struct tun_softc *tp; 599 int s, error = 0; 600 601 s = splnet(); 602 tp = tun_find_unit(dev); 603 604 /* interface was "destroyed" already */ 605 if (tp == NULL) { 606 error = ENXIO; 607 goto out_nolock; 608 } 609 610 switch (cmd) { 611 case TUNSDEBUG: 612 tundebug = *(int *)data; 613 break; 614 615 case TUNGDEBUG: 616 *(int *)data = tundebug; 617 break; 618 619 case TUNSIFMODE: 620 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 621 case IFF_POINTOPOINT: 622 case IFF_BROADCAST: 623 if (tp->tun_if.if_flags & IFF_UP) { 624 error = EBUSY; 625 goto out; 626 } 627 tp->tun_if.if_flags &= 628 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 629 tp->tun_if.if_flags |= *(int *)data; 630 break; 631 default: 632 error = EINVAL; 633 goto out; 634 } 635 break; 636 637 case TUNSLMODE: 638 if (*(int *)data) 639 tp->tun_flags |= TUN_PREPADDR; 640 else 641 tp->tun_flags &= ~TUN_PREPADDR; 642 break; 643 644 case TUNSIFHEAD: 645 if (*(int *)data) 646 tp->tun_flags |= TUN_IFHEAD; 647 else 648 tp->tun_flags &= ~TUN_IFHEAD; 649 break; 650 651 case TUNGIFHEAD: 652 *(int *)data = (tp->tun_flags & TUN_IFHEAD); 653 break; 654 655 case FIONBIO: 656 if (*(int *)data) 657 tp->tun_flags |= TUN_NBIO; 658 else 659 tp->tun_flags &= ~TUN_NBIO; 660 break; 661 662 case FIOASYNC: 663 if (*(int *)data) 664 tp->tun_flags |= TUN_ASYNC; 665 else 666 tp->tun_flags &= ~TUN_ASYNC; 667 break; 668 669 case FIONREAD: 670 if (tp->tun_if.if_snd.ifq_head) 671 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 672 else 673 *(int *)data = 0; 674 break; 675 676 case TIOCSPGRP: 677 case FIOSETOWN: 678 error = fsetown(l->l_proc, &tp->tun_pgid, cmd, data); 679 break; 680 681 case TIOCGPGRP: 682 case FIOGETOWN: 683 error = fgetown(l->l_proc, tp->tun_pgid, cmd, data); 684 break; 685 686 default: 687 error = ENOTTY; 688 } 689 690 out: 691 simple_unlock(&tp->tun_lock); 692 out_nolock: 693 splx(s); 694 return (error); 695 } 696 697 /* 698 * The cdevsw read interface - reads a packet at a time, or at 699 * least as much of a packet as can be read. 700 */ 701 int 702 tunread(dev_t dev, struct uio *uio, int ioflag) 703 { 704 struct tun_softc *tp; 705 struct ifnet *ifp; 706 struct mbuf *m, *m0; 707 int error = 0, len, s, index; 708 709 s = splnet(); 710 tp = tun_find_unit(dev); 711 712 /* interface was "destroyed" already */ 713 if (tp == NULL) { 714 error = ENXIO; 715 goto out_nolock; 716 } 717 718 index = tp->tun_if.if_index; 719 ifp = &tp->tun_if; 720 721 TUNDEBUG ("%s: read\n", ifp->if_xname); 722 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 723 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 724 error = EHOSTDOWN; 725 goto out; 726 } 727 728 tp->tun_flags &= ~TUN_RWAIT; 729 730 do { 731 IFQ_DEQUEUE(&ifp->if_snd, m0); 732 if (m0 == 0) { 733 if (tp->tun_flags & TUN_NBIO) { 734 error = EWOULDBLOCK; 735 goto out; 736 } 737 tp->tun_flags |= TUN_RWAIT; 738 if (ltsleep((caddr_t)tp, PZERO|PCATCH|PNORELOCK, 739 "tunread", 0, &tp->tun_lock) != 0) { 740 error = EINTR; 741 goto out_nolock; 742 } else { 743 /* 744 * Maybe the interface was destroyed while 745 * we were sleeping, so let's ensure that 746 * we're looking at the same (valid) tun 747 * interface before looping. 748 */ 749 tp = tun_find_unit(dev); 750 if (tp == NULL) { 751 error = ENXIO; 752 goto out_nolock; 753 } 754 if (tp->tun_if.if_index != index) { 755 error = ENXIO; 756 goto out; 757 } 758 } 759 } 760 } while (m0 == 0); 761 762 simple_unlock(&tp->tun_lock); 763 splx(s); 764 765 /* Copy the mbuf chain */ 766 while (m0 && uio->uio_resid > 0 && error == 0) { 767 len = min(uio->uio_resid, m0->m_len); 768 if (len != 0) 769 error = uiomove(mtod(m0, caddr_t), len, uio); 770 MFREE(m0, m); 771 m0 = m; 772 } 773 774 if (m0) { 775 TUNDEBUG("Dropping mbuf\n"); 776 m_freem(m0); 777 } 778 if (error) 779 ifp->if_ierrors++; 780 781 return (error); 782 783 out: 784 simple_unlock(&tp->tun_lock); 785 out_nolock: 786 splx(s); 787 return (error); 788 } 789 790 /* 791 * the cdevsw write interface - an atomic write is a packet - or else! 792 */ 793 int 794 tunwrite(dev_t dev, struct uio *uio, int ioflag) 795 { 796 struct tun_softc *tp; 797 struct ifnet *ifp; 798 struct mbuf *top, **mp, *m; 799 struct ifqueue *ifq; 800 struct sockaddr dst; 801 int isr, error = 0, s, tlen, mlen; 802 uint32_t family; 803 804 s = splnet(); 805 tp = tun_find_unit(dev); 806 807 /* interface was "destroyed" already */ 808 if (tp == NULL) { 809 error = ENXIO; 810 goto out_nolock; 811 } 812 813 /* Unlock until we've got the data */ 814 simple_unlock(&tp->tun_lock); 815 splx(s); 816 817 ifp = &tp->tun_if; 818 819 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 820 821 if (tp->tun_flags & TUN_PREPADDR) { 822 if (uio->uio_resid < sizeof(dst)) { 823 error = EIO; 824 goto out0; 825 } 826 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 827 if (dst.sa_len > sizeof(dst)) { 828 /* Duh.. */ 829 char discard; 830 int n = dst.sa_len - sizeof(dst); 831 while (n--) 832 if ((error = uiomove(&discard, 1, uio)) != 0) { 833 goto out0; 834 } 835 } 836 } else if (tp->tun_flags & TUN_IFHEAD) { 837 if (uio->uio_resid < sizeof(family)){ 838 error = EIO; 839 goto out0; 840 } 841 error = uiomove((caddr_t)&family, sizeof(family), uio); 842 dst.sa_family = ntohl(family); 843 } else { 844 #ifdef INET 845 dst.sa_family = AF_INET; 846 #endif 847 } 848 849 if (uio->uio_resid > TUNMTU) { 850 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 851 (unsigned long)uio->uio_resid); 852 error = EIO; 853 goto out0; 854 } 855 856 switch (dst.sa_family) { 857 #ifdef INET 858 case AF_INET: 859 ifq = &ipintrq; 860 isr = NETISR_IP; 861 break; 862 #endif 863 #ifdef INET6 864 case AF_INET6: 865 ifq = &ip6intrq; 866 isr = NETISR_IPV6; 867 break; 868 #endif 869 default: 870 error = EAFNOSUPPORT; 871 goto out0; 872 } 873 874 tlen = uio->uio_resid; 875 876 /* get a header mbuf */ 877 MGETHDR(m, M_DONTWAIT, MT_DATA); 878 if (m == NULL) { 879 error = ENOBUFS; 880 goto out0; 881 } 882 mlen = MHLEN; 883 884 top = NULL; 885 mp = ⊤ 886 while (error == 0 && uio->uio_resid > 0) { 887 m->m_len = min(mlen, uio->uio_resid); 888 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 889 *mp = m; 890 mp = &m->m_next; 891 if (error == 0 && uio->uio_resid > 0) { 892 MGET(m, M_DONTWAIT, MT_DATA); 893 if (m == NULL) { 894 error = ENOBUFS; 895 break; 896 } 897 mlen = MLEN; 898 } 899 } 900 if (error) { 901 if (top != NULL) 902 m_freem (top); 903 ifp->if_ierrors++; 904 goto out0; 905 } 906 907 top->m_pkthdr.len = tlen; 908 top->m_pkthdr.rcvif = ifp; 909 910 #if NBPFILTER > 0 911 if (ifp->if_bpf) 912 bpf_mtap_af(ifp->if_bpf, dst.sa_family, top); 913 #endif 914 915 s = splnet(); 916 simple_lock(&tp->tun_lock); 917 if ((tp->tun_flags & TUN_INITED) == 0) { 918 /* Interface was destroyed */ 919 error = ENXIO; 920 goto out; 921 } 922 if (IF_QFULL(ifq)) { 923 IF_DROP(ifq); 924 ifp->if_collisions++; 925 m_freem(top); 926 error = ENOBUFS; 927 goto out; 928 } 929 930 IF_ENQUEUE(ifq, top); 931 ifp->if_ipackets++; 932 ifp->if_ibytes += tlen; 933 schednetisr(isr); 934 out: 935 simple_unlock(&tp->tun_lock); 936 out_nolock: 937 splx(s); 938 out0: 939 return (error); 940 } 941 942 #ifdef ALTQ 943 /* 944 * Start packet transmission on the interface. 945 * when the interface queue is rate-limited by ALTQ or TBR, 946 * if_start is needed to drain packets from the queue in order 947 * to notify readers when outgoing packets become ready. 948 * 949 * Should be called at splnet. 950 */ 951 static void 952 tunstart(struct ifnet *ifp) 953 { 954 struct tun_softc *tp = ifp->if_softc; 955 956 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 957 return; 958 959 simple_lock(&tp->tun_lock); 960 if (!IF_IS_EMPTY(&ifp->if_snd)) { 961 if (tp->tun_flags & TUN_RWAIT) { 962 tp->tun_flags &= ~TUN_RWAIT; 963 wakeup((caddr_t)tp); 964 } 965 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 966 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 967 POLLOUT|POLLWRNORM, NULL); 968 969 selwakeup(&tp->tun_rsel); 970 } 971 simple_unlock(&tp->tun_lock); 972 } 973 #endif /* ALTQ */ 974 /* 975 * tunpoll - the poll interface, this is only useful on reads 976 * really. The write detect always returns true, write never blocks 977 * anyway, it either accepts the packet or drops it. 978 */ 979 int 980 tunpoll(dev_t dev, int events, struct lwp *l) 981 { 982 struct tun_softc *tp; 983 struct ifnet *ifp; 984 int s, revents = 0; 985 986 s = splnet(); 987 tp = tun_find_unit(dev); 988 989 /* interface was "destroyed" already */ 990 if (tp == NULL) 991 goto out_nolock; 992 993 ifp = &tp->tun_if; 994 995 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 996 997 if (events & (POLLIN | POLLRDNORM)) { 998 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 999 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 1000 ifp->if_snd.ifq_len); 1001 revents |= events & (POLLIN | POLLRDNORM); 1002 } else { 1003 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1004 selrecord(l, &tp->tun_rsel); 1005 } 1006 } 1007 1008 if (events & (POLLOUT | POLLWRNORM)) 1009 revents |= events & (POLLOUT | POLLWRNORM); 1010 1011 simple_unlock(&tp->tun_lock); 1012 out_nolock: 1013 splx(s); 1014 return (revents); 1015 } 1016 1017 static void 1018 filt_tunrdetach(struct knote *kn) 1019 { 1020 struct tun_softc *tp = kn->kn_hook; 1021 int s; 1022 1023 s = splnet(); 1024 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1025 splx(s); 1026 } 1027 1028 static int 1029 filt_tunread(struct knote *kn, long hint) 1030 { 1031 struct tun_softc *tp = kn->kn_hook; 1032 struct ifnet *ifp = &tp->tun_if; 1033 struct mbuf *m; 1034 int s; 1035 1036 s = splnet(); 1037 IF_POLL(&ifp->if_snd, m); 1038 if (m == NULL) { 1039 splx(s); 1040 return (0); 1041 } 1042 1043 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1044 kn->kn_data += m->m_len; 1045 1046 splx(s); 1047 return (1); 1048 } 1049 1050 static const struct filterops tunread_filtops = 1051 { 1, NULL, filt_tunrdetach, filt_tunread }; 1052 1053 static const struct filterops tun_seltrue_filtops = 1054 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1055 1056 int 1057 tunkqfilter(dev_t dev, struct knote *kn) 1058 { 1059 struct tun_softc *tp; 1060 struct klist *klist; 1061 int rv = 0, s; 1062 1063 s = splnet(); 1064 tp = tun_find_unit(dev); 1065 if (tp == NULL) 1066 goto out_nolock; 1067 1068 switch (kn->kn_filter) { 1069 case EVFILT_READ: 1070 klist = &tp->tun_rsel.sel_klist; 1071 kn->kn_fop = &tunread_filtops; 1072 break; 1073 1074 case EVFILT_WRITE: 1075 klist = &tp->tun_rsel.sel_klist; 1076 kn->kn_fop = &tun_seltrue_filtops; 1077 break; 1078 1079 default: 1080 rv = 1; 1081 goto out; 1082 } 1083 1084 kn->kn_hook = tp; 1085 1086 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1087 1088 out: 1089 simple_unlock(&tp->tun_lock); 1090 out_nolock: 1091 splx(s); 1092 return (rv); 1093 } 1094
Indexes created Wed Sep 24 02:09:48 GMT 2025