if_tun.c revision 1.57
1 /* $NetBSD: if_tun.c,v 1.57 2002/11/26 18:51:19 christos 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 1.57 2002/11/26 18:51:19 christos 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_dlt = DLT_NULL; 165 IFQ_SET_READY(&ifp->if_snd); 166 if_attach(ifp); 167 if_alloc_sadl(ifp); 168 #if NBPFILTER > 0 169 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 170 #endif 171 } 172 173 void 174 tun_clone_destroy(ifp) 175 struct ifnet *ifp; 176 { 177 struct tun_softc *tp = (void *)ifp; 178 struct proc *p; 179 180 simple_lock(&tun_softc_lock); 181 simple_lock(&tp->tun_lock); 182 LIST_REMOVE(tp, tun_list); 183 simple_unlock(&tp->tun_lock); 184 simple_unlock(&tun_softc_lock); 185 186 if (tp->tun_flags & TUN_RWAIT) { 187 tp->tun_flags &= ~TUN_RWAIT; 188 wakeup((caddr_t)tp); 189 } 190 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 191 if (tp->tun_pgrp > 0) 192 gsignal(tp->tun_pgrp, SIGIO); 193 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 194 psignal(p, SIGIO); 195 } 196 selwakeup(&tp->tun_rsel); 197 198 #if NBPFILTER > 0 199 bpfdetach(ifp); 200 #endif 201 if_detach(ifp); 202 203 free(tp, M_DEVBUF); 204 } 205 206 static struct tun_softc * 207 tun_find_unit(dev) 208 dev_t dev; 209 { 210 struct tun_softc *tp; 211 int unit = minor(dev); 212 213 simple_lock(&tun_softc_lock); 214 LIST_FOREACH(tp, &tun_softc_list, tun_list) 215 if (unit == tp->tun_unit) 216 break; 217 if (tp) 218 simple_lock(&tp->tun_lock); 219 simple_unlock(&tun_softc_lock); 220 221 return (tp); 222 } 223 224 /* 225 * tunnel open - must be superuser & the device must be 226 * configured in 227 */ 228 int 229 tunopen(dev, flag, mode, p) 230 dev_t dev; 231 int flag, mode; 232 struct proc *p; 233 { 234 struct ifnet *ifp; 235 struct tun_softc *tp; 236 int error; 237 238 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 239 return (error); 240 241 if (NTUN < 1) 242 return (ENXIO); 243 244 tp = tun_find_unit(dev); 245 246 if (!tp) { 247 (void)tun_clone_create(&tun_cloner, minor(dev)); 248 tp = tun_find_unit(dev); 249 } 250 251 if (!tp) 252 return (ENXIO); 253 254 if (tp->tun_flags & TUN_OPEN) { 255 simple_unlock(&tp->tun_lock); 256 return (EBUSY); 257 } 258 259 ifp = &tp->tun_if; 260 tp->tun_flags |= TUN_OPEN; 261 TUNDEBUG("%s: open\n", ifp->if_xname); 262 simple_unlock(&tp->tun_lock); 263 return (0); 264 } 265 266 /* 267 * tunclose - close the device - mark i/f down & delete 268 * routing info 269 */ 270 int 271 tunclose(dev, flag, mode, p) 272 dev_t dev; 273 int flag; 274 int mode; 275 struct proc *p; 276 { 277 int s; 278 struct tun_softc *tp; 279 struct ifnet *ifp; 280 281 tp = tun_find_unit(dev); 282 283 /* interface was "destroyed" before the close */ 284 if (tp == NULL) 285 return (0); 286 287 ifp = &tp->tun_if; 288 289 tp->tun_flags &= ~TUN_OPEN; 290 291 /* 292 * junk all pending output 293 */ 294 s = splnet(); 295 IFQ_PURGE(&ifp->if_snd); 296 splx(s); 297 298 if (ifp->if_flags & IFF_UP) { 299 s = splnet(); 300 if_down(ifp); 301 if (ifp->if_flags & IFF_RUNNING) { 302 /* find internet addresses and delete routes */ 303 struct ifaddr *ifa; 304 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 305 #ifdef INET 306 if (ifa->ifa_addr->sa_family == AF_INET) { 307 rtinit(ifa, (int)RTM_DELETE, 308 tp->tun_flags & TUN_DSTADDR 309 ? RTF_HOST 310 : 0); 311 } 312 #endif 313 } 314 } 315 splx(s); 316 } 317 tp->tun_pgrp = 0; 318 selnotify(&tp->tun_rsel, 0); 319 320 TUNDEBUG ("%s: closed\n", ifp->if_xname); 321 simple_unlock(&tp->tun_lock); 322 return (0); 323 } 324 325 static void 326 tuninit(tp) 327 struct tun_softc *tp; 328 { 329 struct ifnet *ifp = &tp->tun_if; 330 struct ifaddr *ifa; 331 332 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 333 334 ifp->if_flags |= IFF_UP | IFF_RUNNING; 335 336 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 337 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 338 #ifdef INET 339 if (ifa->ifa_addr->sa_family == AF_INET) { 340 struct sockaddr_in *sin; 341 342 sin = satosin(ifa->ifa_addr); 343 if (sin && sin->sin_addr.s_addr) 344 tp->tun_flags |= TUN_IASET; 345 346 if (ifp->if_flags & IFF_POINTOPOINT) { 347 sin = satosin(ifa->ifa_dstaddr); 348 if (sin && sin->sin_addr.s_addr) 349 tp->tun_flags |= TUN_DSTADDR; 350 } 351 } 352 #endif 353 } 354 355 return; 356 } 357 358 /* 359 * Process an ioctl request. 360 */ 361 int 362 tun_ioctl(ifp, cmd, data) 363 struct ifnet *ifp; 364 u_long cmd; 365 caddr_t data; 366 { 367 int error = 0, s; 368 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 369 370 simple_lock(&tp->tun_lock); 371 372 s = splnet(); 373 switch(cmd) { 374 case SIOCSIFADDR: 375 tuninit((struct tun_softc *)(ifp->if_softc)); 376 TUNDEBUG("%s: address set\n", ifp->if_xname); 377 break; 378 case SIOCSIFDSTADDR: 379 tuninit((struct tun_softc *)(ifp->if_softc)); 380 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 381 break; 382 case SIOCSIFBRDADDR: 383 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 384 break; 385 case SIOCSIFMTU: { 386 struct ifreq *ifr = (struct ifreq *) data; 387 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 388 error = EINVAL; 389 break; 390 } 391 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 392 ifp->if_mtu = ifr->ifr_mtu; 393 break; 394 } 395 case SIOCADDMULTI: 396 case SIOCDELMULTI: { 397 struct ifreq *ifr = (struct ifreq *) data; 398 if (ifr == 0) { 399 error = EAFNOSUPPORT; /* XXX */ 400 break; 401 } 402 switch (ifr->ifr_addr.sa_family) { 403 404 #ifdef INET 405 case AF_INET: 406 break; 407 #endif 408 409 default: 410 error = EAFNOSUPPORT; 411 break; 412 } 413 break; 414 } 415 case SIOCSIFFLAGS: 416 break; 417 default: 418 error = EINVAL; 419 } 420 splx(s); 421 simple_unlock(&tp->tun_lock); 422 return (error); 423 } 424 425 /* 426 * tun_output - queue packets from higher level ready to put out. 427 */ 428 int 429 tun_output(ifp, m0, dst, rt) 430 struct ifnet *ifp; 431 struct mbuf *m0; 432 struct sockaddr *dst; 433 struct rtentry *rt; 434 { 435 struct tun_softc *tp = ifp->if_softc; 436 struct proc *p; 437 #ifdef INET 438 int s; 439 int error; 440 #endif 441 ALTQ_DECL(struct altq_pktattr pktattr;) 442 443 simple_lock(&tp->tun_lock); 444 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 445 446 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 447 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 448 tp->tun_flags); 449 m_freem (m0); 450 simple_unlock(&tp->tun_lock); 451 return (EHOSTDOWN); 452 } 453 454 /* 455 * if the queueing discipline needs packet classification, 456 * do it before prepending link headers. 457 */ 458 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 459 460 #if NBPFILTER > 0 461 if (ifp->if_bpf) { 462 /* 463 * We need to prepend the address family as 464 * a four byte field. Cons up a dummy header 465 * to pacify bpf. This is safe because bpf 466 * will only read from the mbuf (i.e., it won't 467 * try to free it or keep a pointer to it). 468 */ 469 struct mbuf m; 470 u_int32_t af = dst->sa_family; 471 472 m.m_next = m0; 473 m.m_len = sizeof(af); 474 m.m_data = (char *)⁡ 475 476 bpf_mtap(ifp->if_bpf, &m); 477 } 478 #endif 479 480 switch(dst->sa_family) { 481 #ifdef INET 482 case AF_INET: 483 if (tp->tun_flags & TUN_PREPADDR) { 484 /* Simple link-layer header */ 485 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 486 if (m0 == NULL) { 487 IF_DROP(&ifp->if_snd); 488 simple_unlock(&tp->tun_lock); 489 return (ENOBUFS); 490 } 491 bcopy(dst, mtod(m0, char *), dst->sa_len); 492 } 493 /* FALLTHROUGH */ 494 case AF_UNSPEC: 495 s = splnet(); 496 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 497 if (error) { 498 splx(s); 499 ifp->if_collisions++; 500 return (error); 501 } 502 splx(s); 503 ifp->if_opackets++; 504 break; 505 #endif 506 default: 507 m_freem(m0); 508 simple_unlock(&tp->tun_lock); 509 return (EAFNOSUPPORT); 510 } 511 512 if (tp->tun_flags & TUN_RWAIT) { 513 tp->tun_flags &= ~TUN_RWAIT; 514 wakeup((caddr_t)tp); 515 } 516 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 517 if (tp->tun_pgrp > 0) 518 gsignal(tp->tun_pgrp, SIGIO); 519 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 520 psignal(p, SIGIO); 521 } 522 selnotify(&tp->tun_rsel, 0); 523 simple_unlock(&tp->tun_lock); 524 return (0); 525 } 526 527 /* 528 * the cdevsw interface is now pretty minimal. 529 */ 530 int 531 tunioctl(dev, cmd, data, flag, p) 532 dev_t dev; 533 u_long cmd; 534 caddr_t data; 535 int flag; 536 struct proc *p; 537 { 538 int s; 539 struct tun_softc *tp; 540 541 tp = tun_find_unit(dev); 542 543 /* interface was "destroyed" already */ 544 if (tp == NULL) 545 return (ENXIO); 546 547 switch (cmd) { 548 case TUNSDEBUG: 549 tundebug = *(int *)data; 550 break; 551 552 case TUNGDEBUG: 553 *(int *)data = tundebug; 554 break; 555 556 case TUNSIFMODE: 557 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 558 case IFF_POINTOPOINT: 559 case IFF_BROADCAST: 560 s = splnet(); 561 if (tp->tun_if.if_flags & IFF_UP) { 562 splx(s); 563 simple_unlock(&tp->tun_lock); 564 return (EBUSY); 565 } 566 tp->tun_if.if_flags &= 567 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 568 tp->tun_if.if_flags |= *(int *)data; 569 splx(s); 570 break; 571 default: 572 simple_unlock(&tp->tun_lock); 573 return (EINVAL); 574 } 575 break; 576 577 case TUNSLMODE: 578 if (*(int *)data) 579 tp->tun_flags |= TUN_PREPADDR; 580 else 581 tp->tun_flags &= ~TUN_PREPADDR; 582 break; 583 584 case FIONBIO: 585 if (*(int *)data) 586 tp->tun_flags |= TUN_NBIO; 587 else 588 tp->tun_flags &= ~TUN_NBIO; 589 break; 590 591 case FIOASYNC: 592 if (*(int *)data) 593 tp->tun_flags |= TUN_ASYNC; 594 else 595 tp->tun_flags &= ~TUN_ASYNC; 596 break; 597 598 case FIONREAD: 599 s = splnet(); 600 if (tp->tun_if.if_snd.ifq_head) 601 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 602 else 603 *(int *)data = 0; 604 splx(s); 605 break; 606 607 case TIOCSPGRP: 608 tp->tun_pgrp = *(int *)data; 609 break; 610 611 case TIOCGPGRP: 612 *(int *)data = tp->tun_pgrp; 613 break; 614 615 default: 616 simple_unlock(&tp->tun_lock); 617 return (ENOTTY); 618 } 619 simple_unlock(&tp->tun_lock); 620 return (0); 621 } 622 623 /* 624 * The cdevsw read interface - reads a packet at a time, or at 625 * least as much of a packet as can be read. 626 */ 627 int 628 tunread(dev, uio, ioflag) 629 dev_t dev; 630 struct uio *uio; 631 int ioflag; 632 { 633 struct tun_softc *tp; 634 struct ifnet *ifp; 635 struct mbuf *m, *m0; 636 int error=0, len, s, index; 637 638 tp = tun_find_unit(dev); 639 640 /* interface was "destroyed" already */ 641 if (tp == NULL) 642 return (ENXIO); 643 644 index = tp->tun_if.if_index; 645 ifp = &tp->tun_if; 646 647 TUNDEBUG ("%s: read\n", ifp->if_xname); 648 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 649 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 650 simple_unlock(&tp->tun_lock); 651 return EHOSTDOWN; 652 } 653 654 tp->tun_flags &= ~TUN_RWAIT; 655 656 s = splnet(); 657 do { 658 IFQ_DEQUEUE(&ifp->if_snd, m0); 659 if (m0 == 0) { 660 if (tp->tun_flags & TUN_NBIO) { 661 splx(s); 662 simple_unlock(&tp->tun_lock); 663 return (EWOULDBLOCK); 664 } 665 tp->tun_flags |= TUN_RWAIT; 666 simple_unlock(&tp->tun_lock); 667 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 668 splx(s); 669 return (EINTR); 670 } else { 671 /* 672 * Maybe the interface was destroyed while 673 * we were sleeping, so let's ensure that 674 * we're looking at the same (valid) tun 675 * interface before looping. 676 */ 677 tp = tun_find_unit(dev); 678 if (tp == NULL || 679 tp->tun_if.if_index != index) { 680 splx(s); 681 if (tp) 682 simple_unlock(&tp->tun_lock); 683 return (ENXIO); 684 } 685 } 686 } 687 } while (m0 == 0); 688 splx(s); 689 690 while (m0 && uio->uio_resid > 0 && error == 0) { 691 len = min(uio->uio_resid, m0->m_len); 692 if (len != 0) 693 error = uiomove(mtod(m0, caddr_t), len, uio); 694 MFREE(m0, m); 695 m0 = m; 696 } 697 698 if (m0) { 699 TUNDEBUG("Dropping mbuf\n"); 700 m_freem(m0); 701 } 702 if (error) 703 ifp->if_ierrors++; 704 simple_unlock(&tp->tun_lock); 705 return (error); 706 } 707 708 /* 709 * the cdevsw write interface - an atomic write is a packet - or else! 710 */ 711 int 712 tunwrite(dev, uio, ioflag) 713 dev_t dev; 714 struct uio *uio; 715 int ioflag; 716 { 717 struct tun_softc *tp; 718 struct ifnet *ifp; 719 struct mbuf *top, **mp, *m; 720 struct ifqueue *ifq; 721 struct sockaddr dst; 722 int isr, error=0, s, tlen, mlen; 723 724 tp = tun_find_unit(dev); 725 726 /* interface was "destroyed" already */ 727 if (tp == NULL) 728 return (ENXIO); 729 730 ifp = &tp->tun_if; 731 732 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 733 734 if (tp->tun_flags & TUN_PREPADDR) { 735 if (uio->uio_resid < sizeof(dst)) { 736 simple_unlock(&tp->tun_lock); 737 return (EIO); 738 } 739 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 740 if (dst.sa_len > sizeof(dst)) { 741 /* Duh.. */ 742 char discard; 743 int n = dst.sa_len - sizeof(dst); 744 while (n--) 745 if ((error = uiomove(&discard, 1, uio)) != 0) { 746 simple_unlock(&tp->tun_lock); 747 return (error); 748 } 749 } 750 } else { 751 #ifdef INET 752 dst.sa_family = AF_INET; 753 #endif 754 } 755 756 if (uio->uio_resid > TUNMTU) { 757 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 758 (unsigned long)uio->uio_resid); 759 simple_unlock(&tp->tun_lock); 760 return (EIO); 761 } 762 763 switch (dst.sa_family) { 764 #ifdef INET 765 case AF_INET: 766 ifq = &ipintrq; 767 isr = NETISR_IP; 768 break; 769 #endif 770 default: 771 simple_unlock(&tp->tun_lock); 772 return (EAFNOSUPPORT); 773 } 774 775 tlen = uio->uio_resid; 776 777 /* get a header mbuf */ 778 MGETHDR(m, M_DONTWAIT, MT_DATA); 779 if (m == NULL) { 780 simple_unlock(&tp->tun_lock); 781 return (ENOBUFS); 782 } 783 mlen = MHLEN; 784 785 top = 0; 786 mp = ⊤ 787 while (error == 0 && uio->uio_resid > 0) { 788 m->m_len = min(mlen, uio->uio_resid); 789 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 790 *mp = m; 791 mp = &m->m_next; 792 if (uio->uio_resid > 0) { 793 MGET (m, M_DONTWAIT, MT_DATA); 794 if (m == 0) { 795 error = ENOBUFS; 796 break; 797 } 798 mlen = MLEN; 799 } 800 } 801 if (error) { 802 if (top) 803 m_freem (top); 804 ifp->if_ierrors++; 805 simple_unlock(&tp->tun_lock); 806 return (error); 807 } 808 809 top->m_pkthdr.len = tlen; 810 top->m_pkthdr.rcvif = ifp; 811 812 #if NBPFILTER > 0 813 if (ifp->if_bpf) { 814 /* 815 * We need to prepend the address family as 816 * a four byte field. Cons up a dummy header 817 * to pacify bpf. This is safe because bpf 818 * will only read from the mbuf (i.e., it won't 819 * try to free it or keep a pointer to it). 820 */ 821 struct mbuf m; 822 u_int32_t af = AF_INET; 823 824 m.m_next = top; 825 m.m_len = sizeof(af); 826 m.m_data = (char *)⁡ 827 828 bpf_mtap(ifp->if_bpf, &m); 829 } 830 #endif 831 832 s = splnet(); 833 if (IF_QFULL(ifq)) { 834 IF_DROP(ifq); 835 splx(s); 836 ifp->if_collisions++; 837 m_freem(top); 838 simple_unlock(&tp->tun_lock); 839 return (ENOBUFS); 840 } 841 IF_ENQUEUE(ifq, top); 842 splx(s); 843 ifp->if_ipackets++; 844 schednetisr(isr); 845 simple_unlock(&tp->tun_lock); 846 return (error); 847 } 848 849 #ifdef ALTQ 850 /* 851 * Start packet transmission on the interface. 852 * when the interface queue is rate-limited by ALTQ or TBR, 853 * if_start is needed to drain packets from the queue in order 854 * to notify readers when outgoing packets become ready. 855 */ 856 static void 857 tunstart(ifp) 858 struct ifnet *ifp; 859 { 860 struct tun_softc *tp = ifp->if_softc; 861 struct mbuf *m; 862 struct proc *p; 863 864 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 865 return; 866 867 IFQ_POLL(&ifp->if_snd, m); 868 if (m != NULL) { 869 if (tp->tun_flags & TUN_RWAIT) { 870 tp->tun_flags &= ~TUN_RWAIT; 871 wakeup((caddr_t)tp); 872 } 873 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 874 if (tp->tun_pgrp > 0) 875 gsignal(tp->tun_pgrp, SIGIO); 876 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 877 psignal(p, SIGIO); 878 } 879 selwakeup(&tp->tun_rsel); 880 } 881 } 882 #endif /* ALTQ */ 883 /* 884 * tunpoll - the poll interface, this is only useful on reads 885 * really. The write detect always returns true, write never blocks 886 * anyway, it either accepts the packet or drops it. 887 */ 888 int 889 tunpoll(dev, events, p) 890 dev_t dev; 891 int events; 892 struct proc *p; 893 { 894 struct tun_softc *tp; 895 struct ifnet *ifp; 896 int s, revents = 0; 897 898 tp = tun_find_unit(dev); 899 900 /* interface was "destroyed" already */ 901 if (tp == NULL) 902 return (0); 903 904 ifp = &tp->tun_if; 905 906 s = splnet(); 907 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 908 909 if (events & (POLLIN | POLLRDNORM)) { 910 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 911 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 912 ifp->if_snd.ifq_len); 913 revents |= events & (POLLIN | POLLRDNORM); 914 } else { 915 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 916 selrecord(p, &tp->tun_rsel); 917 } 918 } 919 920 if (events & (POLLOUT | POLLWRNORM)) 921 revents |= events & (POLLOUT | POLLWRNORM); 922 923 splx(s); 924 simple_unlock(&tp->tun_lock); 925 return (revents); 926 } 927 928 static void 929 filt_tunrdetach(struct knote *kn) 930 { 931 struct tun_softc *tp = kn->kn_hook; 932 int s; 933 934 s = splnet(); 935 SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext); 936 splx(s); 937 } 938 939 static int 940 filt_tunread(struct knote *kn, long hint) 941 { 942 struct tun_softc *tp = kn->kn_hook; 943 struct ifnet *ifp = &tp->tun_if; 944 struct mbuf *m; 945 int s; 946 947 s = splnet(); 948 IF_POLL(&ifp->if_snd, m); 949 if (m == NULL) { 950 splx(s); 951 return (0); 952 } 953 954 for (kn->kn_data = 0; m != NULL; m = m->m_next) 955 kn->kn_data += m->m_len; 956 957 splx(s); 958 return (1); 959 } 960 961 static const struct filterops tunread_filtops = 962 { 1, NULL, filt_tunrdetach, filt_tunread }; 963 964 static const struct filterops tun_seltrue_filtops = 965 { 1, NULL, filt_tunrdetach, filt_seltrue }; 966 967 int 968 tunkqfilter(dev_t dev, struct knote *kn) 969 { 970 struct tun_softc *tp = tun_find_unit(dev); 971 struct klist *klist; 972 int s; 973 974 switch (kn->kn_filter) { 975 case EVFILT_READ: 976 klist = &tp->tun_rsel.sel_klist; 977 kn->kn_fop = &tunread_filtops; 978 break; 979 980 case EVFILT_WRITE: 981 klist = &tp->tun_rsel.sel_klist; 982 kn->kn_fop = &tun_seltrue_filtops; 983 break; 984 985 default: 986 return (1); 987 } 988 989 kn->kn_hook = tp; 990 991 s = splnet(); 992 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 993 splx(s); 994 995 return (0); 996 } 997
Indexes created Tue Sep 23 07:09:52 GMT 2025