if_tun.c revision 1.63.2.2
1 /* $NetBSD: if_tun.c,v 1.63.2.2 2004/08/03 10:54:18 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 1.63.2.2 2004/08/03 10:54:18 skrll Exp $"); 19 20 #include "tun.h" 21 22 #include "opt_inet.h" 23 #include "opt_ns.h" 24 25 #include <sys/param.h> 26 #include <sys/proc.h> 27 #include <sys/systm.h> 28 #include <sys/mbuf.h> 29 #include <sys/buf.h> 30 #include <sys/protosw.h> 31 #include <sys/socket.h> 32 #include <sys/ioctl.h> 33 #include <sys/errno.h> 34 #include <sys/syslog.h> 35 #include <sys/select.h> 36 #include <sys/poll.h> 37 #include <sys/file.h> 38 #include <sys/signalvar.h> 39 #include <sys/conf.h> 40 41 #include <machine/cpu.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 49 #ifdef INET 50 #include <netinet/in.h> 51 #include <netinet/in_systm.h> 52 #include <netinet/in_var.h> 53 #include <netinet/ip.h> 54 #include <netinet/if_inarp.h> 55 #endif 56 57 #ifdef NS 58 #include <netns/ns.h> 59 #include <netns/ns_if.h> 60 #endif 61 62 #include "bpfilter.h" 63 #if NBPFILTER > 0 64 #include <sys/time.h> 65 #include <net/bpf.h> 66 #endif 67 68 #include <net/if_tun.h> 69 70 #define TUNDEBUG if (tundebug) printf 71 int tundebug = 0; 72 73 extern int ifqmaxlen; 74 void tunattach __P((int)); 75 LIST_HEAD(, tun_softc) tun_softc_list; 76 LIST_HEAD(, tun_softc) tunz_softc_list; 77 static struct simplelock tun_softc_lock; 78 79 int tun_ioctl __P((struct ifnet *, u_long, caddr_t)); 80 int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 81 struct rtentry *rt)); 82 int tun_clone_create __P((struct if_clone *, int)); 83 void tun_clone_destroy __P((struct ifnet *)); 84 85 struct if_clone tun_cloner = 86 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 87 88 static void tunattach0 __P((struct tun_softc *)); 89 static void tuninit __P((struct tun_softc *)); 90 #ifdef ALTQ 91 static void tunstart __P((struct ifnet *)); 92 #endif 93 static struct tun_softc *tun_find_unit __P((dev_t)); 94 static struct tun_softc *tun_find_zunit __P((int)); 95 96 dev_type_open(tunopen); 97 dev_type_close(tunclose); 98 dev_type_read(tunread); 99 dev_type_write(tunwrite); 100 dev_type_ioctl(tunioctl); 101 dev_type_poll(tunpoll); 102 dev_type_kqfilter(tunkqfilter); 103 104 const struct cdevsw tun_cdevsw = { 105 tunopen, tunclose, tunread, tunwrite, tunioctl, 106 nostop, notty, tunpoll, nommap, tunkqfilter, 107 }; 108 109 void 110 tunattach(unused) 111 int unused; 112 { 113 114 simple_lock_init(&tun_softc_lock); 115 LIST_INIT(&tun_softc_list); 116 LIST_INIT(&tunz_softc_list); 117 if_clone_attach(&tun_cloner); 118 } 119 120 /* 121 * Find driver instance from dev_t. 122 * Call at splnet(). 123 * Returns with tp locked (if found). 124 */ 125 static struct tun_softc * 126 tun_find_unit(dev) 127 dev_t dev; 128 { 129 struct tun_softc *tp; 130 int unit = minor(dev); 131 132 simple_lock(&tun_softc_lock); 133 LIST_FOREACH(tp, &tun_softc_list, tun_list) 134 if (unit == tp->tun_unit) 135 break; 136 if (tp) 137 simple_lock(&tp->tun_lock); 138 simple_unlock(&tun_softc_lock); 139 140 return (tp); 141 } 142 143 /* 144 * Find zombie driver instance by unit number. 145 * Call at splnet(). 146 * Remove tp from list and return it unlocked (if found). 147 */ 148 static struct tun_softc * 149 tun_find_zunit(unit) 150 int unit; 151 { 152 struct tun_softc *tp; 153 154 simple_lock(&tun_softc_lock); 155 LIST_FOREACH(tp, &tunz_softc_list, tun_list) 156 if (unit == tp->tun_unit) 157 break; 158 if (tp) 159 LIST_REMOVE(tp, tun_list); 160 simple_unlock(&tun_softc_lock); 161 #ifdef DIAGNOSTIC 162 if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN) 163 printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags); 164 #endif 165 166 return (tp); 167 } 168 169 int 170 tun_clone_create(ifc, unit) 171 struct if_clone *ifc; 172 int unit; 173 { 174 struct tun_softc *tp; 175 176 if ((tp = tun_find_zunit(unit)) == NULL) { 177 /* Allocate a new instance */ 178 tp = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 179 (void)memset(tp, 0, sizeof(struct tun_softc)); 180 181 tp->tun_unit = unit; 182 simple_lock_init(&tp->tun_lock); 183 } else { 184 /* Revive tunnel instance; clear ifp part */ 185 (void)memset(&tp->tun_if, 0, sizeof(struct ifnet)); 186 } 187 188 (void)snprintf(tp->tun_if.if_xname, sizeof(tp->tun_if.if_xname), 189 "%s%d", ifc->ifc_name, unit); 190 tunattach0(tp); 191 tp->tun_flags |= TUN_INITED; 192 193 simple_lock(&tun_softc_lock); 194 LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); 195 simple_unlock(&tun_softc_lock); 196 197 return (0); 198 } 199 200 void 201 tunattach0(tp) 202 struct tun_softc *tp; 203 { 204 struct ifnet *ifp; 205 206 ifp = &tp->tun_if; 207 ifp->if_softc = tp; 208 ifp->if_mtu = TUNMTU; 209 ifp->if_ioctl = tun_ioctl; 210 ifp->if_output = tun_output; 211 #ifdef ALTQ 212 ifp->if_start = tunstart; 213 #endif 214 ifp->if_flags = IFF_POINTOPOINT; 215 ifp->if_type = IFT_TUNNEL; 216 ifp->if_snd.ifq_maxlen = ifqmaxlen; 217 ifp->if_collisions = 0; 218 ifp->if_ierrors = 0; 219 ifp->if_oerrors = 0; 220 ifp->if_ipackets = 0; 221 ifp->if_opackets = 0; 222 ifp->if_ibytes = 0; 223 ifp->if_obytes = 0; 224 ifp->if_dlt = DLT_NULL; 225 IFQ_SET_READY(&ifp->if_snd); 226 if_attach(ifp); 227 if_alloc_sadl(ifp); 228 #if NBPFILTER > 0 229 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 230 #endif 231 } 232 233 void 234 tun_clone_destroy(ifp) 235 struct ifnet *ifp; 236 { 237 struct tun_softc *tp = (void *)ifp; 238 int s, zombie = 0; 239 240 s = splnet(); 241 simple_lock(&tun_softc_lock); 242 simple_lock(&tp->tun_lock); 243 LIST_REMOVE(tp, tun_list); 244 if (tp->tun_flags & TUN_OPEN) { 245 /* Hang on to storage until last close */ 246 zombie = 1; 247 tp->tun_flags &= ~TUN_INITED; 248 LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); 249 } 250 simple_unlock(&tun_softc_lock); 251 252 IF_PURGE(&ifp->if_snd); 253 ifp->if_flags &= ~IFF_RUNNING; 254 255 if (tp->tun_flags & TUN_RWAIT) { 256 tp->tun_flags &= ~TUN_RWAIT; 257 wakeup((caddr_t)tp); 258 } 259 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 260 fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); 261 262 selwakeup(&tp->tun_rsel); 263 264 simple_unlock(&tp->tun_lock); 265 splx(s); 266 267 #if NBPFILTER > 0 268 bpfdetach(ifp); 269 #endif 270 if_detach(ifp); 271 272 if (!zombie) 273 free(tp, M_DEVBUF); 274 } 275 276 /* 277 * tunnel open - must be superuser & the device must be 278 * configured in 279 */ 280 int 281 tunopen(dev, flag, mode, l) 282 dev_t dev; 283 int flag, mode; 284 struct lwp *l; 285 { 286 struct proc *p = l->l_proc; 287 struct ifnet *ifp; 288 struct tun_softc *tp; 289 int s, error; 290 291 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 292 return (error); 293 294 if (NTUN < 1) 295 return (ENXIO); 296 297 s = splnet(); 298 tp = tun_find_unit(dev); 299 300 if (tp == NULL) { 301 (void)tun_clone_create(&tun_cloner, minor(dev)); 302 tp = tun_find_unit(dev); 303 if (tp == NULL) { 304 error = ENXIO; 305 goto out_nolock; 306 } 307 } 308 309 if (tp->tun_flags & TUN_OPEN) { 310 error = EBUSY; 311 goto out; 312 } 313 314 ifp = &tp->tun_if; 315 tp->tun_flags |= TUN_OPEN; 316 TUNDEBUG("%s: open\n", ifp->if_xname); 317 out: 318 simple_unlock(&tp->tun_lock); 319 out_nolock: 320 splx(s); 321 return (error); 322 } 323 324 /* 325 * tunclose - close the device - mark i/f down & delete 326 * routing info 327 */ 328 int 329 tunclose(dev, flag, mode, l) 330 dev_t dev; 331 int flag; 332 int mode; 333 struct lwp *l; 334 { 335 int s; 336 struct tun_softc *tp; 337 struct ifnet *ifp; 338 339 s = splnet(); 340 if ((tp = tun_find_zunit(minor(dev))) != NULL) { 341 /* interface was "destroyed" before the close */ 342 free(tp, M_DEVBUF); 343 goto out_nolock; 344 } 345 346 if ((tp = tun_find_unit(dev)) == NULL) 347 goto out_nolock; 348 349 ifp = &tp->tun_if; 350 351 tp->tun_flags &= ~TUN_OPEN; 352 353 /* 354 * junk all pending output 355 */ 356 IFQ_PURGE(&ifp->if_snd); 357 358 if (ifp->if_flags & IFF_UP) { 359 if_down(ifp); 360 if (ifp->if_flags & IFF_RUNNING) { 361 /* find internet addresses and delete routes */ 362 struct ifaddr *ifa; 363 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 364 #ifdef INET 365 if (ifa->ifa_addr->sa_family == AF_INET) { 366 rtinit(ifa, (int)RTM_DELETE, 367 tp->tun_flags & TUN_DSTADDR 368 ? RTF_HOST 369 : 0); 370 } 371 #endif 372 } 373 } 374 } 375 tp->tun_pgid = 0; 376 selnotify(&tp->tun_rsel, 0); 377 378 TUNDEBUG ("%s: closed\n", ifp->if_xname); 379 simple_unlock(&tp->tun_lock); 380 out_nolock: 381 splx(s); 382 return (0); 383 } 384 385 /* 386 * Call at splnet() with tp locked. 387 */ 388 static void 389 tuninit(tp) 390 struct tun_softc *tp; 391 { 392 struct ifnet *ifp = &tp->tun_if; 393 struct ifaddr *ifa; 394 395 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 396 397 ifp->if_flags |= IFF_UP | IFF_RUNNING; 398 399 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 400 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 401 #ifdef INET 402 if (ifa->ifa_addr->sa_family == AF_INET) { 403 struct sockaddr_in *sin; 404 405 sin = satosin(ifa->ifa_addr); 406 if (sin && sin->sin_addr.s_addr) 407 tp->tun_flags |= TUN_IASET; 408 409 if (ifp->if_flags & IFF_POINTOPOINT) { 410 sin = satosin(ifa->ifa_dstaddr); 411 if (sin && sin->sin_addr.s_addr) 412 tp->tun_flags |= TUN_DSTADDR; 413 } 414 } 415 #endif 416 } 417 418 return; 419 } 420 421 /* 422 * Process an ioctl request. 423 */ 424 int 425 tun_ioctl(ifp, cmd, data) 426 struct ifnet *ifp; 427 u_long cmd; 428 caddr_t data; 429 { 430 int error = 0, s; 431 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 432 433 s = splnet(); 434 simple_lock(&tp->tun_lock); 435 436 switch (cmd) { 437 case SIOCSIFADDR: 438 tuninit(tp); 439 TUNDEBUG("%s: address set\n", ifp->if_xname); 440 break; 441 case SIOCSIFDSTADDR: 442 tuninit(tp); 443 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 444 break; 445 case SIOCSIFBRDADDR: 446 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 447 break; 448 case SIOCSIFMTU: { 449 struct ifreq *ifr = (struct ifreq *) data; 450 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 451 error = EINVAL; 452 break; 453 } 454 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 455 ifp->if_mtu = ifr->ifr_mtu; 456 break; 457 } 458 case SIOCADDMULTI: 459 case SIOCDELMULTI: { 460 struct ifreq *ifr = (struct ifreq *) data; 461 if (ifr == 0) { 462 error = EAFNOSUPPORT; /* XXX */ 463 break; 464 } 465 switch (ifr->ifr_addr.sa_family) { 466 #ifdef INET 467 case AF_INET: 468 break; 469 #endif 470 default: 471 error = EAFNOSUPPORT; 472 break; 473 } 474 break; 475 } 476 case SIOCSIFFLAGS: 477 break; 478 default: 479 error = EINVAL; 480 } 481 482 simple_unlock(&tp->tun_lock); 483 splx(s); 484 return (error); 485 } 486 487 /* 488 * tun_output - queue packets from higher level ready to put out. 489 */ 490 int 491 tun_output(ifp, m0, dst, rt) 492 struct ifnet *ifp; 493 struct mbuf *m0; 494 struct sockaddr *dst; 495 struct rtentry *rt; 496 { 497 struct tun_softc *tp = ifp->if_softc; 498 #ifdef INET 499 int s; 500 int error; 501 #endif 502 int mlen; 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 /* 526 * We need to prepend the address family as 527 * a four-byte field. Note that dst->sa_family 528 * is not always a four-byte field. 529 */ 530 u_int32_t af = dst->sa_family; 531 532 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0); 533 } 534 #endif 535 536 switch(dst->sa_family) { 537 #ifdef INET 538 case AF_INET: 539 if (tp->tun_flags & TUN_PREPADDR) { 540 /* Simple link-layer header */ 541 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 542 if (m0 == NULL) { 543 IF_DROP(&ifp->if_snd); 544 error = ENOBUFS; 545 goto out; 546 } 547 bcopy(dst, mtod(m0, char *), dst->sa_len); 548 } 549 /* FALLTHROUGH */ 550 case AF_UNSPEC: 551 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 552 if (error) { 553 ifp->if_collisions++; 554 error = EAFNOSUPPORT; 555 goto out; 556 } 557 mlen = m0->m_pkthdr.len; 558 ifp->if_opackets++; 559 ifp->if_obytes += mlen; 560 break; 561 #endif 562 default: 563 m_freem(m0); 564 error = EAFNOSUPPORT; 565 goto out; 566 } 567 568 if (tp->tun_flags & TUN_RWAIT) { 569 tp->tun_flags &= ~TUN_RWAIT; 570 wakeup((caddr_t)tp); 571 } 572 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 573 fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, 574 NULL); 575 576 selnotify(&tp->tun_rsel, 0); 577 out: 578 simple_unlock(&tp->tun_lock); 579 splx(s); 580 return (0); 581 } 582 583 /* 584 * the cdevsw interface is now pretty minimal. 585 */ 586 int 587 tunioctl(dev, cmd, data, flag, l) 588 dev_t dev; 589 u_long cmd; 590 caddr_t data; 591 int flag; 592 struct lwp *l; 593 { 594 struct tun_softc *tp; 595 int s, error = 0; 596 597 s = splnet(); 598 tp = tun_find_unit(dev); 599 600 /* interface was "destroyed" already */ 601 if (tp == NULL) { 602 error = ENXIO; 603 goto out_nolock; 604 } 605 606 switch (cmd) { 607 case TUNSDEBUG: 608 tundebug = *(int *)data; 609 break; 610 611 case TUNGDEBUG: 612 *(int *)data = tundebug; 613 break; 614 615 case TUNSIFMODE: 616 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 617 case IFF_POINTOPOINT: 618 case IFF_BROADCAST: 619 if (tp->tun_if.if_flags & IFF_UP) { 620 error = EBUSY; 621 goto out; 622 } 623 tp->tun_if.if_flags &= 624 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 625 tp->tun_if.if_flags |= *(int *)data; 626 break; 627 default: 628 error = EINVAL; 629 goto out; 630 } 631 break; 632 633 case TUNSLMODE: 634 if (*(int *)data) 635 tp->tun_flags |= TUN_PREPADDR; 636 else 637 tp->tun_flags &= ~TUN_PREPADDR; 638 break; 639 640 case FIONBIO: 641 if (*(int *)data) 642 tp->tun_flags |= TUN_NBIO; 643 else 644 tp->tun_flags &= ~TUN_NBIO; 645 break; 646 647 case FIOASYNC: 648 if (*(int *)data) 649 tp->tun_flags |= TUN_ASYNC; 650 else 651 tp->tun_flags &= ~TUN_ASYNC; 652 break; 653 654 case FIONREAD: 655 if (tp->tun_if.if_snd.ifq_head) 656 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 657 else 658 *(int *)data = 0; 659 break; 660 661 case TIOCSPGRP: 662 case FIOSETOWN: 663 error = fsetown(l->l_proc, &tp->tun_pgid, cmd, data); 664 break; 665 666 case TIOCGPGRP: 667 case FIOGETOWN: 668 error = fgetown(l->l_proc, tp->tun_pgid, cmd, data); 669 break; 670 671 default: 672 error = ENOTTY; 673 } 674 675 out: 676 simple_unlock(&tp->tun_lock); 677 out_nolock: 678 splx(s); 679 return (error); 680 } 681 682 /* 683 * The cdevsw read interface - reads a packet at a time, or at 684 * least as much of a packet as can be read. 685 */ 686 int 687 tunread(dev, uio, ioflag) 688 dev_t dev; 689 struct uio *uio; 690 int ioflag; 691 { 692 struct tun_softc *tp; 693 struct ifnet *ifp; 694 struct mbuf *m, *m0; 695 int error = 0, len, s, index; 696 697 s = splnet(); 698 tp = tun_find_unit(dev); 699 700 /* interface was "destroyed" already */ 701 if (tp == NULL) { 702 error = ENXIO; 703 goto out_nolock; 704 } 705 706 index = tp->tun_if.if_index; 707 ifp = &tp->tun_if; 708 709 TUNDEBUG ("%s: read\n", ifp->if_xname); 710 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 711 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 712 error = EHOSTDOWN; 713 goto out; 714 } 715 716 tp->tun_flags &= ~TUN_RWAIT; 717 718 do { 719 IFQ_DEQUEUE(&ifp->if_snd, m0); 720 if (m0 == 0) { 721 if (tp->tun_flags & TUN_NBIO) { 722 error = EWOULDBLOCK; 723 goto out; 724 } 725 tp->tun_flags |= TUN_RWAIT; 726 if (ltsleep((caddr_t)tp, PZERO|PCATCH|PNORELOCK, 727 "tunread", 0, &tp->tun_lock) != 0) { 728 error = EINTR; 729 goto out_nolock; 730 } else { 731 /* 732 * Maybe the interface was destroyed while 733 * we were sleeping, so let's ensure that 734 * we're looking at the same (valid) tun 735 * interface before looping. 736 */ 737 tp = tun_find_unit(dev); 738 if (tp == NULL) { 739 error = ENXIO; 740 goto out_nolock; 741 } 742 if (tp->tun_if.if_index != index) { 743 error = ENXIO; 744 goto out; 745 } 746 } 747 } 748 } while (m0 == 0); 749 750 simple_unlock(&tp->tun_lock); 751 splx(s); 752 753 /* Copy the mbuf chain */ 754 while (m0 && uio->uio_resid > 0 && error == 0) { 755 len = min(uio->uio_resid, m0->m_len); 756 if (len != 0) 757 error = uiomove(mtod(m0, caddr_t), len, uio); 758 MFREE(m0, m); 759 m0 = m; 760 } 761 762 if (m0) { 763 TUNDEBUG("Dropping mbuf\n"); 764 m_freem(m0); 765 } 766 if (error) 767 ifp->if_ierrors++; 768 769 return (error); 770 771 out: 772 simple_unlock(&tp->tun_lock); 773 out_nolock: 774 splx(s); 775 return (error); 776 } 777 778 /* 779 * the cdevsw write interface - an atomic write is a packet - or else! 780 */ 781 int 782 tunwrite(dev, uio, ioflag) 783 dev_t dev; 784 struct uio *uio; 785 int ioflag; 786 { 787 struct tun_softc *tp; 788 struct ifnet *ifp; 789 struct mbuf *top, **mp, *m; 790 struct ifqueue *ifq; 791 struct sockaddr dst; 792 int isr, error = 0, s, tlen, mlen; 793 794 s = splnet(); 795 tp = tun_find_unit(dev); 796 797 /* interface was "destroyed" already */ 798 if (tp == NULL) { 799 error = ENXIO; 800 goto out_nolock; 801 } 802 803 /* Unlock until we've got the data */ 804 simple_unlock(&tp->tun_lock); 805 splx(s); 806 807 ifp = &tp->tun_if; 808 809 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 810 811 if (tp->tun_flags & TUN_PREPADDR) { 812 if (uio->uio_resid < sizeof(dst)) { 813 error = EIO; 814 goto out0; 815 } 816 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 817 if (dst.sa_len > sizeof(dst)) { 818 /* Duh.. */ 819 char discard; 820 int n = dst.sa_len - sizeof(dst); 821 while (n--) 822 if ((error = uiomove(&discard, 1, uio)) != 0) { 823 goto out0; 824 } 825 } 826 } else { 827 #ifdef INET 828 dst.sa_family = AF_INET; 829 #endif 830 } 831 832 if (uio->uio_resid > TUNMTU) { 833 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 834 (unsigned long)uio->uio_resid); 835 error = EIO; 836 goto out0; 837 } 838 839 switch (dst.sa_family) { 840 #ifdef INET 841 case AF_INET: 842 ifq = &ipintrq; 843 isr = NETISR_IP; 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, caddr_t), 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 #if NBPFILTER > 0 888 if (ifp->if_bpf) { 889 /* 890 * We need to prepend the address family as 891 * a four byte field. Cons up a dummy header 892 * to pacify bpf. This is safe because bpf 893 * will only read from the mbuf (i.e., it won't 894 * try to free it or keep a pointer to it). 895 */ 896 struct mbuf m; 897 u_int32_t af = AF_INET; 898 899 m.m_flags = 0; 900 m.m_next = top; 901 m.m_len = sizeof(af); 902 m.m_data = (char *)⁡ 903 904 bpf_mtap(ifp->if_bpf, &m); 905 } 906 #endif 907 908 s = splnet(); 909 simple_lock(&tp->tun_lock); 910 if ((tp->tun_flags & TUN_INITED) == 0) { 911 /* Interface was destroyed */ 912 error = ENXIO; 913 goto out; 914 } 915 if (IF_QFULL(ifq)) { 916 IF_DROP(ifq); 917 ifp->if_collisions++; 918 m_freem(top); 919 error = ENOBUFS; 920 goto out; 921 } 922 923 IF_ENQUEUE(ifq, top); 924 ifp->if_ipackets++; 925 ifp->if_ibytes += tlen; 926 schednetisr(isr); 927 out: 928 simple_unlock(&tp->tun_lock); 929 out_nolock: 930 splx(s); 931 out0: 932 return (error); 933 } 934 935 #ifdef ALTQ 936 /* 937 * Start packet transmission on the interface. 938 * when the interface queue is rate-limited by ALTQ or TBR, 939 * if_start is needed to drain packets from the queue in order 940 * to notify readers when outgoing packets become ready. 941 * 942 * Should be called at splnet. 943 */ 944 static void 945 tunstart(ifp) 946 struct ifnet *ifp; 947 { 948 struct tun_softc *tp = ifp->if_softc; 949 950 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 951 return; 952 953 simple_lock(&tp->tun_lock); 954 if (!IF_IS_EMPTY(&ifp->if_snd)) { 955 if (tp->tun_flags & TUN_RWAIT) { 956 tp->tun_flags &= ~TUN_RWAIT; 957 wakeup((caddr_t)tp); 958 } 959 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) 960 fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, 961 POLLOUT|POLLWRNORM, NULL); 962 963 selwakeup(&tp->tun_rsel); 964 } 965 simple_unlock(&tp->tun_lock); 966 } 967 #endif /* ALTQ */ 968 /* 969 * tunpoll - the poll interface, this is only useful on reads 970 * really. The write detect always returns true, write never blocks 971 * anyway, it either accepts the packet or drops it. 972 */ 973 int 974 tunpoll(dev, events, l) 975 dev_t dev; 976 int events; 977 struct lwp *l; 978 { 979 struct tun_softc *tp; 980 struct ifnet *ifp; 981 int s, revents = 0; 982 983 s = splnet(); 984 tp = tun_find_unit(dev); 985 986 /* interface was "destroyed" already */ 987 if (tp == NULL) 988 goto out_nolock; 989 990 ifp = &tp->tun_if; 991 992 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 993 994 if (events & (POLLIN | POLLRDNORM)) { 995 if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 996 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 997 ifp->if_snd.ifq_len); 998 revents |= events & (POLLIN | POLLRDNORM); 999 } else { 1000 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 1001 selrecord(l, &tp->tun_rsel); 1002 } 1003 } 1004 1005 if (events & (POLLOUT | POLLWRNORM)) 1006 revents |= events & (POLLOUT | POLLWRNORM); 1007 1008 simple_unlock(&tp->tun_lock); 1009 out_nolock: 1010 splx(s); 1011 return (revents); 1012 } 1013 1014 static void 1015 filt_tunrdetach(struct knote *kn) 1016 { 1017 struct tun_softc *tp = kn->kn_hook; 1018 int s; 1019 1020 s = splnet(); 1021 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 1022 splx(s); 1023 } 1024 1025 static int 1026 filt_tunread(struct knote *kn, long hint) 1027 { 1028 struct tun_softc *tp = kn->kn_hook; 1029 struct ifnet *ifp = &tp->tun_if; 1030 struct mbuf *m; 1031 int s; 1032 1033 s = splnet(); 1034 IF_POLL(&ifp->if_snd, m); 1035 if (m == NULL) { 1036 splx(s); 1037 return (0); 1038 } 1039 1040 for (kn->kn_data = 0; m != NULL; m = m->m_next) 1041 kn->kn_data += m->m_len; 1042 1043 splx(s); 1044 return (1); 1045 } 1046 1047 static const struct filterops tunread_filtops = 1048 { 1, NULL, filt_tunrdetach, filt_tunread }; 1049 1050 static const struct filterops tun_seltrue_filtops = 1051 { 1, NULL, filt_tunrdetach, filt_seltrue }; 1052 1053 int 1054 tunkqfilter(dev_t dev, struct knote *kn) 1055 { 1056 struct tun_softc *tp; 1057 struct klist *klist; 1058 int rv = 0, s; 1059 1060 s = splnet(); 1061 tp = tun_find_unit(dev); 1062 if (tp == NULL) 1063 goto out_nolock; 1064 1065 switch (kn->kn_filter) { 1066 case EVFILT_READ: 1067 klist = &tp->tun_rsel.sel_klist; 1068 kn->kn_fop = &tunread_filtops; 1069 break; 1070 1071 case EVFILT_WRITE: 1072 klist = &tp->tun_rsel.sel_klist; 1073 kn->kn_fop = &tun_seltrue_filtops; 1074 break; 1075 1076 default: 1077 rv = 1; 1078 goto out; 1079 } 1080 1081 kn->kn_hook = tp; 1082 1083 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1084 1085 out: 1086 simple_unlock(&tp->tun_lock); 1087 out_nolock: 1088 splx(s); 1089 return (rv); 1090 } 1091
Indexes created Mon Oct 20 16:09:52 GMT 2025