if_tun.c revision 1.59
1 /* $NetBSD: if_tun.c,v 1.59 2003/03/13 10:24:38 dsl 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 1.59 2003/03/13 10:24:38 dsl 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_ether.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 static struct simplelock tun_softc_lock; 77 78 int tun_ioctl __P((struct ifnet *, u_long, caddr_t)); 79 int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 80 struct rtentry *rt)); 81 int tun_clone_create __P((struct if_clone *, int)); 82 void tun_clone_destroy __P((struct ifnet *)); 83 84 struct if_clone tun_cloner = 85 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 86 87 static void tunattach0 __P((struct tun_softc *)); 88 static void tuninit __P((struct tun_softc *)); 89 #ifdef ALTQ 90 static void tunstart __P((struct ifnet *)); 91 #endif 92 static struct tun_softc *tun_find_unit __P((dev_t)); 93 94 dev_type_open(tunopen); 95 dev_type_close(tunclose); 96 dev_type_read(tunread); 97 dev_type_write(tunwrite); 98 dev_type_ioctl(tunioctl); 99 dev_type_poll(tunpoll); 100 dev_type_kqfilter(tunkqfilter); 101 102 const struct cdevsw tun_cdevsw = { 103 tunopen, tunclose, tunread, tunwrite, tunioctl, 104 nostop, notty, tunpoll, nommap, tunkqfilter, 105 }; 106 107 void 108 tunattach(unused) 109 int unused; 110 { 111 112 simple_lock_init(&tun_softc_lock); 113 LIST_INIT(&tun_softc_list); 114 if_clone_attach(&tun_cloner); 115 } 116 117 int 118 tun_clone_create(ifc, unit) 119 struct if_clone *ifc; 120 int unit; 121 { 122 struct tun_softc *sc; 123 124 sc = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 125 (void)memset(sc, 0, sizeof(struct tun_softc)); 126 127 (void)snprintf(sc->tun_if.if_xname, sizeof(sc->tun_if.if_xname), 128 "%s%d", ifc->ifc_name, unit); 129 sc->tun_unit = unit; 130 simple_lock_init(&sc->tun_lock); 131 132 tunattach0(sc); 133 134 simple_lock(&tun_softc_lock); 135 LIST_INSERT_HEAD(&tun_softc_list, sc, tun_list); 136 simple_unlock(&tun_softc_lock); 137 138 return (0); 139 } 140 141 void 142 tunattach0(sc) 143 struct tun_softc *sc; 144 { 145 struct ifnet *ifp = (void *)sc; 146 147 sc->tun_flags = TUN_INITED; 148 149 ifp = &sc->tun_if; 150 ifp->if_softc = sc; 151 ifp->if_mtu = TUNMTU; 152 ifp->if_ioctl = tun_ioctl; 153 ifp->if_output = tun_output; 154 #ifdef ALTQ 155 ifp->if_start = tunstart; 156 #endif 157 ifp->if_flags = IFF_POINTOPOINT; 158 ifp->if_snd.ifq_maxlen = ifqmaxlen; 159 ifp->if_collisions = 0; 160 ifp->if_ierrors = 0; 161 ifp->if_oerrors = 0; 162 ifp->if_ipackets = 0; 163 ifp->if_opackets = 0; 164 ifp->if_ibytes = 0; 165 ifp->if_obytes = 0; 166 ifp->if_dlt = DLT_NULL; 167 IFQ_SET_READY(&ifp->if_snd); 168 if_attach(ifp); 169 if_alloc_sadl(ifp); 170 #if NBPFILTER > 0 171 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 172 #endif 173 } 174 175 void 176 tun_clone_destroy(ifp) 177 struct ifnet *ifp; 178 { 179 struct tun_softc *tp = (void *)ifp; 180 struct proc *p; 181 182 simple_lock(&tun_softc_lock); 183 simple_lock(&tp->tun_lock); 184 LIST_REMOVE(tp, tun_list); 185 simple_unlock(&tp->tun_lock); 186 simple_unlock(&tun_softc_lock); 187 188 if (tp->tun_flags & TUN_RWAIT) { 189 tp->tun_flags &= ~TUN_RWAIT; 190 wakeup((caddr_t)tp); 191 } 192 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 193 if (tp->tun_pgrp > 0) 194 gsignal(tp->tun_pgrp, SIGIO); 195 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 196 psignal(p, SIGIO); 197 } 198 selwakeup(&tp->tun_rsel); 199 200 #if NBPFILTER > 0 201 bpfdetach(ifp); 202 #endif 203 if_detach(ifp); 204 205 free(tp, M_DEVBUF); 206 } 207 208 static struct tun_softc * 209 tun_find_unit(dev) 210 dev_t dev; 211 { 212 struct tun_softc *tp; 213 int unit = minor(dev); 214 215 simple_lock(&tun_softc_lock); 216 LIST_FOREACH(tp, &tun_softc_list, tun_list) 217 if (unit == tp->tun_unit) 218 break; 219 if (tp) 220 simple_lock(&tp->tun_lock); 221 simple_unlock(&tun_softc_lock); 222 223 return (tp); 224 } 225 226 /* 227 * tunnel open - must be superuser & the device must be 228 * configured in 229 */ 230 int 231 tunopen(dev, flag, mode, p) 232 dev_t dev; 233 int flag, mode; 234 struct proc *p; 235 { 236 struct ifnet *ifp; 237 struct tun_softc *tp; 238 int error; 239 240 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 241 return (error); 242 243 if (NTUN < 1) 244 return (ENXIO); 245 246 tp = tun_find_unit(dev); 247 248 if (!tp) { 249 (void)tun_clone_create(&tun_cloner, minor(dev)); 250 tp = tun_find_unit(dev); 251 } 252 253 if (!tp) 254 return (ENXIO); 255 256 if (tp->tun_flags & TUN_OPEN) { 257 simple_unlock(&tp->tun_lock); 258 return (EBUSY); 259 } 260 261 ifp = &tp->tun_if; 262 tp->tun_flags |= TUN_OPEN; 263 TUNDEBUG("%s: open\n", ifp->if_xname); 264 simple_unlock(&tp->tun_lock); 265 return (0); 266 } 267 268 /* 269 * tunclose - close the device - mark i/f down & delete 270 * routing info 271 */ 272 int 273 tunclose(dev, flag, mode, p) 274 dev_t dev; 275 int flag; 276 int mode; 277 struct proc *p; 278 { 279 int s; 280 struct tun_softc *tp; 281 struct ifnet *ifp; 282 283 tp = tun_find_unit(dev); 284 285 /* interface was "destroyed" before the close */ 286 if (tp == NULL) 287 return (0); 288 289 ifp = &tp->tun_if; 290 291 tp->tun_flags &= ~TUN_OPEN; 292 293 /* 294 * junk all pending output 295 */ 296 s = splnet(); 297 IFQ_PURGE(&ifp->if_snd); 298 splx(s); 299 300 if (ifp->if_flags & IFF_UP) { 301 s = splnet(); 302 if_down(ifp); 303 if (ifp->if_flags & IFF_RUNNING) { 304 /* find internet addresses and delete routes */ 305 struct ifaddr *ifa; 306 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 307 #ifdef INET 308 if (ifa->ifa_addr->sa_family == AF_INET) { 309 rtinit(ifa, (int)RTM_DELETE, 310 tp->tun_flags & TUN_DSTADDR 311 ? RTF_HOST 312 : 0); 313 } 314 #endif 315 } 316 } 317 splx(s); 318 } 319 tp->tun_pgrp = 0; 320 selnotify(&tp->tun_rsel, 0); 321 322 TUNDEBUG ("%s: closed\n", ifp->if_xname); 323 simple_unlock(&tp->tun_lock); 324 return (0); 325 } 326 327 static void 328 tuninit(tp) 329 struct tun_softc *tp; 330 { 331 struct ifnet *ifp = &tp->tun_if; 332 struct ifaddr *ifa; 333 334 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 335 336 ifp->if_flags |= IFF_UP | IFF_RUNNING; 337 338 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 339 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 340 #ifdef INET 341 if (ifa->ifa_addr->sa_family == AF_INET) { 342 struct sockaddr_in *sin; 343 344 sin = satosin(ifa->ifa_addr); 345 if (sin && sin->sin_addr.s_addr) 346 tp->tun_flags |= TUN_IASET; 347 348 if (ifp->if_flags & IFF_POINTOPOINT) { 349 sin = satosin(ifa->ifa_dstaddr); 350 if (sin && sin->sin_addr.s_addr) 351 tp->tun_flags |= TUN_DSTADDR; 352 } 353 } 354 #endif 355 } 356 357 return; 358 } 359 360 /* 361 * Process an ioctl request. 362 */ 363 int 364 tun_ioctl(ifp, cmd, data) 365 struct ifnet *ifp; 366 u_long cmd; 367 caddr_t data; 368 { 369 int error = 0, s; 370 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 371 372 simple_lock(&tp->tun_lock); 373 374 s = splnet(); 375 switch(cmd) { 376 case SIOCSIFADDR: 377 tuninit((struct tun_softc *)(ifp->if_softc)); 378 TUNDEBUG("%s: address set\n", ifp->if_xname); 379 break; 380 case SIOCSIFDSTADDR: 381 tuninit((struct tun_softc *)(ifp->if_softc)); 382 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 383 break; 384 case SIOCSIFBRDADDR: 385 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 386 break; 387 case SIOCSIFMTU: { 388 struct ifreq *ifr = (struct ifreq *) data; 389 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 390 error = EINVAL; 391 break; 392 } 393 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 394 ifp->if_mtu = ifr->ifr_mtu; 395 break; 396 } 397 case SIOCADDMULTI: 398 case SIOCDELMULTI: { 399 struct ifreq *ifr = (struct ifreq *) data; 400 if (ifr == 0) { 401 error = EAFNOSUPPORT; /* XXX */ 402 break; 403 } 404 switch (ifr->ifr_addr.sa_family) { 405 406 #ifdef INET 407 case AF_INET: 408 break; 409 #endif 410 411 default: 412 error = EAFNOSUPPORT; 413 break; 414 } 415 break; 416 } 417 case SIOCSIFFLAGS: 418 break; 419 default: 420 error = EINVAL; 421 } 422 splx(s); 423 simple_unlock(&tp->tun_lock); 424 return (error); 425 } 426 427 /* 428 * tun_output - queue packets from higher level ready to put out. 429 */ 430 int 431 tun_output(ifp, m0, dst, rt) 432 struct ifnet *ifp; 433 struct mbuf *m0; 434 struct sockaddr *dst; 435 struct rtentry *rt; 436 { 437 struct tun_softc *tp = ifp->if_softc; 438 struct proc *p; 439 #ifdef INET 440 int s; 441 int error; 442 #endif 443 int mlen; 444 ALTQ_DECL(struct altq_pktattr pktattr;) 445 446 simple_lock(&tp->tun_lock); 447 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 448 449 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 450 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 451 tp->tun_flags); 452 m_freem (m0); 453 simple_unlock(&tp->tun_lock); 454 return (EHOSTDOWN); 455 } 456 457 /* 458 * if the queueing discipline needs packet classification, 459 * do it before prepending link headers. 460 */ 461 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 462 463 #if NBPFILTER > 0 464 if (ifp->if_bpf) { 465 /* 466 * We need to prepend the address family as 467 * a four byte field. Cons up a dummy header 468 * to pacify bpf. This is safe because bpf 469 * will only read from the mbuf (i.e., it won't 470 * try to free it or keep a pointer to it). 471 */ 472 struct mbuf m; 473 u_int32_t af = dst->sa_family; 474 475 m.m_next = m0; 476 m.m_len = sizeof(af); 477 m.m_data = (char *)⁡ 478 479 bpf_mtap(ifp->if_bpf, &m); 480 } 481 #endif 482 483 switch(dst->sa_family) { 484 #ifdef INET 485 case AF_INET: 486 if (tp->tun_flags & TUN_PREPADDR) { 487 /* Simple link-layer header */ 488 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 489 if (m0 == NULL) { 490 IF_DROP(&ifp->if_snd); 491 simple_unlock(&tp->tun_lock); 492 return (ENOBUFS); 493 } 494 bcopy(dst, mtod(m0, char *), dst->sa_len); 495 } 496 /* FALLTHROUGH */ 497 case AF_UNSPEC: 498 s = splnet(); 499 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 500 if (error) { 501 splx(s); 502 ifp->if_collisions++; 503 return (error); 504 } 505 mlen = m0->m_pkthdr.len; 506 splx(s); 507 ifp->if_opackets++; 508 ifp->if_obytes += mlen; 509 break; 510 #endif 511 default: 512 m_freem(m0); 513 simple_unlock(&tp->tun_lock); 514 return (EAFNOSUPPORT); 515 } 516 517 if (tp->tun_flags & TUN_RWAIT) { 518 tp->tun_flags &= ~TUN_RWAIT; 519 wakeup((caddr_t)tp); 520 } 521 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 522 if (tp->tun_pgrp > 0) 523 gsignal(tp->tun_pgrp, SIGIO); 524 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 525 psignal(p, SIGIO); 526 } 527 selnotify(&tp->tun_rsel, 0); 528 simple_unlock(&tp->tun_lock); 529 return (0); 530 } 531 532 /* 533 * the cdevsw interface is now pretty minimal. 534 */ 535 int 536 tunioctl(dev, cmd, data, flag, p) 537 dev_t dev; 538 u_long cmd; 539 caddr_t data; 540 int flag; 541 struct proc *p; 542 { 543 int s; 544 struct tun_softc *tp; 545 pid_t pgid; 546 int error; 547 548 tp = tun_find_unit(dev); 549 550 /* interface was "destroyed" already */ 551 if (tp == NULL) 552 return (ENXIO); 553 554 switch (cmd) { 555 case TUNSDEBUG: 556 tundebug = *(int *)data; 557 break; 558 559 case TUNGDEBUG: 560 *(int *)data = tundebug; 561 break; 562 563 case TUNSIFMODE: 564 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 565 case IFF_POINTOPOINT: 566 case IFF_BROADCAST: 567 s = splnet(); 568 if (tp->tun_if.if_flags & IFF_UP) { 569 splx(s); 570 simple_unlock(&tp->tun_lock); 571 return (EBUSY); 572 } 573 tp->tun_if.if_flags &= 574 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 575 tp->tun_if.if_flags |= *(int *)data; 576 splx(s); 577 break; 578 default: 579 simple_unlock(&tp->tun_lock); 580 return (EINVAL); 581 } 582 break; 583 584 case TUNSLMODE: 585 if (*(int *)data) 586 tp->tun_flags |= TUN_PREPADDR; 587 else 588 tp->tun_flags &= ~TUN_PREPADDR; 589 break; 590 591 case FIONBIO: 592 if (*(int *)data) 593 tp->tun_flags |= TUN_NBIO; 594 else 595 tp->tun_flags &= ~TUN_NBIO; 596 break; 597 598 case FIOASYNC: 599 if (*(int *)data) 600 tp->tun_flags |= TUN_ASYNC; 601 else 602 tp->tun_flags &= ~TUN_ASYNC; 603 break; 604 605 case FIONREAD: 606 s = splnet(); 607 if (tp->tun_if.if_snd.ifq_head) 608 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 609 else 610 *(int *)data = 0; 611 splx(s); 612 break; 613 614 case TIOCSPGRP: 615 pgid = *(int *)data; 616 if (pgid != 0) { 617 error = pgid_in_session(p, pgid); 618 if (error != 0) 619 return error; 620 } 621 tp->tun_pgrp = pgid; 622 break; 623 624 case TIOCGPGRP: 625 *(int *)data = tp->tun_pgrp; 626 break; 627 628 default: 629 simple_unlock(&tp->tun_lock); 630 return (ENOTTY); 631 } 632 simple_unlock(&tp->tun_lock); 633 return (0); 634 } 635 636 /* 637 * The cdevsw read interface - reads a packet at a time, or at 638 * least as much of a packet as can be read. 639 */ 640 int 641 tunread(dev, uio, ioflag) 642 dev_t dev; 643 struct uio *uio; 644 int ioflag; 645 { 646 struct tun_softc *tp; 647 struct ifnet *ifp; 648 struct mbuf *m, *m0; 649 int error=0, len, s, index; 650 651 tp = tun_find_unit(dev); 652 653 /* interface was "destroyed" already */ 654 if (tp == NULL) 655 return (ENXIO); 656 657 index = tp->tun_if.if_index; 658 ifp = &tp->tun_if; 659 660 TUNDEBUG ("%s: read\n", ifp->if_xname); 661 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 662 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 663 simple_unlock(&tp->tun_lock); 664 return EHOSTDOWN; 665 } 666 667 tp->tun_flags &= ~TUN_RWAIT; 668 669 s = splnet(); 670 do { 671 IFQ_DEQUEUE(&ifp->if_snd, m0); 672 if (m0 == 0) { 673 if (tp->tun_flags & TUN_NBIO) { 674 splx(s); 675 simple_unlock(&tp->tun_lock); 676 return (EWOULDBLOCK); 677 } 678 tp->tun_flags |= TUN_RWAIT; 679 simple_unlock(&tp->tun_lock); 680 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 681 splx(s); 682 return (EINTR); 683 } else { 684 /* 685 * Maybe the interface was destroyed while 686 * we were sleeping, so let's ensure that 687 * we're looking at the same (valid) tun 688 * interface before looping. 689 */ 690 tp = tun_find_unit(dev); 691 if (tp == NULL || 692 tp->tun_if.if_index != index) { 693 splx(s); 694 if (tp) 695 simple_unlock(&tp->tun_lock); 696 return (ENXIO); 697 } 698 } 699 } 700 } while (m0 == 0); 701 splx(s); 702 703 while (m0 && uio->uio_resid > 0 && error == 0) { 704 len = min(uio->uio_resid, m0->m_len); 705 if (len != 0) 706 error = uiomove(mtod(m0, caddr_t), len, uio); 707 MFREE(m0, m); 708 m0 = m; 709 } 710 711 if (m0) { 712 TUNDEBUG("Dropping mbuf\n"); 713 m_freem(m0); 714 } 715 if (error) 716 ifp->if_ierrors++; 717 simple_unlock(&tp->tun_lock); 718 return (error); 719 } 720 721 /* 722 * the cdevsw write interface - an atomic write is a packet - or else! 723 */ 724 int 725 tunwrite(dev, uio, ioflag) 726 dev_t dev; 727 struct uio *uio; 728 int ioflag; 729 { 730 struct tun_softc *tp; 731 struct ifnet *ifp; 732 struct mbuf *top, **mp, *m; 733 struct ifqueue *ifq; 734 struct sockaddr dst; 735 int isr, error=0, s, tlen, mlen; 736 737 tp = tun_find_unit(dev); 738 739 /* interface was "destroyed" already */ 740 if (tp == NULL) 741 return (ENXIO); 742 743 ifp = &tp->tun_if; 744 745 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 746 747 if (tp->tun_flags & TUN_PREPADDR) { 748 if (uio->uio_resid < sizeof(dst)) { 749 simple_unlock(&tp->tun_lock); 750 return (EIO); 751 } 752 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 753 if (dst.sa_len > sizeof(dst)) { 754 /* Duh.. */ 755 char discard; 756 int n = dst.sa_len - sizeof(dst); 757 while (n--) 758 if ((error = uiomove(&discard, 1, uio)) != 0) { 759 simple_unlock(&tp->tun_lock); 760 return (error); 761 } 762 } 763 } else { 764 #ifdef INET 765 dst.sa_family = AF_INET; 766 #endif 767 } 768 769 if (uio->uio_resid > TUNMTU) { 770 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 771 (unsigned long)uio->uio_resid); 772 simple_unlock(&tp->tun_lock); 773 return (EIO); 774 } 775 776 switch (dst.sa_family) { 777 #ifdef INET 778 case AF_INET: 779 ifq = &ipintrq; 780 isr = NETISR_IP; 781 break; 782 #endif 783 default: 784 simple_unlock(&tp->tun_lock); 785 return (EAFNOSUPPORT); 786 } 787 788 tlen = uio->uio_resid; 789 790 /* get a header mbuf */ 791 MGETHDR(m, M_DONTWAIT, MT_DATA); 792 if (m == NULL) { 793 simple_unlock(&tp->tun_lock); 794 return (ENOBUFS); 795 } 796 mlen = MHLEN; 797 798 top = 0; 799 mp = ⊤ 800 while (error == 0 && uio->uio_resid > 0) { 801 m->m_len = min(mlen, uio->uio_resid); 802 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 803 *mp = m; 804 mp = &m->m_next; 805 if (uio->uio_resid > 0) { 806 MGET (m, M_DONTWAIT, MT_DATA); 807 if (m == 0) { 808 error = ENOBUFS; 809 break; 810 } 811 mlen = MLEN; 812 } 813 } 814 if (error) { 815 if (top) 816 m_freem (top); 817 ifp->if_ierrors++; 818 simple_unlock(&tp->tun_lock); 819 return (error); 820 } 821 822 top->m_pkthdr.len = tlen; 823 top->m_pkthdr.rcvif = ifp; 824 825 #if NBPFILTER > 0 826 if (ifp->if_bpf) { 827 /* 828 * We need to prepend the address family as 829 * a four byte field. Cons up a dummy header 830 * to pacify bpf. This is safe because bpf 831 * will only read from the mbuf (i.e., it won't 832 * try to free it or keep a pointer to it). 833 */ 834 struct mbuf m; 835 u_int32_t af = AF_INET; 836 837 m.m_next = top; 838 m.m_len = sizeof(af); 839 m.m_data = (char *)⁡ 840 841 bpf_mtap(ifp->if_bpf, &m); 842 } 843 #endif 844 845 s = splnet(); 846 if (IF_QFULL(ifq)) { 847 IF_DROP(ifq); 848 splx(s); 849 ifp->if_collisions++; 850 m_freem(top); 851 simple_unlock(&tp->tun_lock); 852 return (ENOBUFS); 853 } 854 IF_ENQUEUE(ifq, top); 855 splx(s); 856 ifp->if_ipackets++; 857 ifp->if_ibytes += tlen; 858 schednetisr(isr); 859 simple_unlock(&tp->tun_lock); 860 return (error); 861 } 862 863 #ifdef ALTQ 864 /* 865 * Start packet transmission on the interface. 866 * when the interface queue is rate-limited by ALTQ or TBR, 867 * if_start is needed to drain packets from the queue in order 868 * to notify readers when outgoing packets become ready. 869 */ 870 static void 871 tunstart(ifp) 872 struct ifnet *ifp; 873 { 874 struct tun_softc *tp = ifp->if_softc; 875 struct mbuf *m; 876 struct proc *p; 877 878 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 879 return; 880 881 IFQ_POLL(&ifp->if_snd, m); 882 if (m != NULL) { 883 if (tp->tun_flags & TUN_RWAIT) { 884 tp->tun_flags &= ~TUN_RWAIT; 885 wakeup((caddr_t)tp); 886 } 887 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 888 if (tp->tun_pgrp > 0) 889 gsignal(tp->tun_pgrp, SIGIO); 890 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 891 psignal(p, SIGIO); 892 } 893 selwakeup(&tp->tun_rsel); 894 } 895 } 896 #endif /* ALTQ */ 897 /* 898 * tunpoll - the poll interface, this is only useful on reads 899 * really. The write detect always returns true, write never blocks 900 * anyway, it either accepts the packet or drops it. 901 */ 902 int 903 tunpoll(dev, events, p) 904 dev_t dev; 905 int events; 906 struct proc *p; 907 { 908 struct tun_softc *tp; 909 struct ifnet *ifp; 910 int s, revents = 0; 911 912 tp = tun_find_unit(dev); 913 914 /* interface was "destroyed" already */ 915 if (tp == NULL) 916 return (0); 917 918 ifp = &tp->tun_if; 919 920 s = splnet(); 921 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 922 923 if (events & (POLLIN | POLLRDNORM)) { 924 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 925 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 926 ifp->if_snd.ifq_len); 927 revents |= events & (POLLIN | POLLRDNORM); 928 } else { 929 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 930 selrecord(p, &tp->tun_rsel); 931 } 932 } 933 934 if (events & (POLLOUT | POLLWRNORM)) 935 revents |= events & (POLLOUT | POLLWRNORM); 936 937 splx(s); 938 simple_unlock(&tp->tun_lock); 939 return (revents); 940 } 941 942 static void 943 filt_tunrdetach(struct knote *kn) 944 { 945 struct tun_softc *tp = kn->kn_hook; 946 int s; 947 948 s = splnet(); 949 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 950 splx(s); 951 } 952 953 static int 954 filt_tunread(struct knote *kn, long hint) 955 { 956 struct tun_softc *tp = kn->kn_hook; 957 struct ifnet *ifp = &tp->tun_if; 958 struct mbuf *m; 959 int s; 960 961 s = splnet(); 962 IF_POLL(&ifp->if_snd, m); 963 if (m == NULL) { 964 splx(s); 965 return (0); 966 } 967 968 for (kn->kn_data = 0; m != NULL; m = m->m_next) 969 kn->kn_data += m->m_len; 970 971 splx(s); 972 return (1); 973 } 974 975 static const struct filterops tunread_filtops = 976 { 1, NULL, filt_tunrdetach, filt_tunread }; 977 978 static const struct filterops tun_seltrue_filtops = 979 { 1, NULL, filt_tunrdetach, filt_seltrue }; 980 981 int 982 tunkqfilter(dev_t dev, struct knote *kn) 983 { 984 struct tun_softc *tp = tun_find_unit(dev); 985 struct klist *klist; 986 int s; 987 988 switch (kn->kn_filter) { 989 case EVFILT_READ: 990 klist = &tp->tun_rsel.sel_klist; 991 kn->kn_fop = &tunread_filtops; 992 break; 993 994 case EVFILT_WRITE: 995 klist = &tp->tun_rsel.sel_klist; 996 kn->kn_fop = &tun_seltrue_filtops; 997 break; 998 999 default: 1000 return (1); 1001 } 1002 1003 kn->kn_hook = tp; 1004 1005 s = splnet(); 1006 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 1007 splx(s); 1008 1009 return (0); 1010 } 1011
Indexes created Fri Sep 26 20:09:58 GMT 2025