if_tun.c revision 1.52
1 /* $NetBSD: if_tun.c,v 1.52 2002/07/29 16:53:30 atatat 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 1.52 2002/07/29 16:53:30 atatat 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 void 95 tunattach(unused) 96 int unused; 97 { 98 99 simple_lock_init(&tun_softc_lock); 100 LIST_INIT(&tun_softc_list); 101 if_clone_attach(&tun_cloner); 102 } 103 104 int 105 tun_clone_create(ifc, unit) 106 struct if_clone *ifc; 107 int unit; 108 { 109 struct tun_softc *sc; 110 111 sc = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 112 (void)memset(sc, 0, sizeof(struct tun_softc)); 113 114 (void)snprintf(sc->tun_if.if_xname, sizeof(sc->tun_if.if_xname), 115 "%s%d", ifc->ifc_name, unit); 116 sc->tun_unit = unit; 117 simple_lock_init(&sc->tun_lock); 118 119 tunattach0(sc); 120 121 simple_lock(&tun_softc_lock); 122 LIST_INSERT_HEAD(&tun_softc_list, sc, tun_list); 123 simple_unlock(&tun_softc_lock); 124 125 return (0); 126 } 127 128 void 129 tunattach0(sc) 130 struct tun_softc *sc; 131 { 132 struct ifnet *ifp = (void *)sc; 133 134 sc->tun_flags = TUN_INITED; 135 136 ifp = &sc->tun_if; 137 ifp->if_softc = sc; 138 ifp->if_mtu = TUNMTU; 139 ifp->if_ioctl = tun_ioctl; 140 ifp->if_output = tun_output; 141 #ifdef ALTQ 142 ifp->if_start = tunstart; 143 #endif 144 ifp->if_flags = IFF_POINTOPOINT; 145 ifp->if_snd.ifq_maxlen = ifqmaxlen; 146 ifp->if_collisions = 0; 147 ifp->if_ierrors = 0; 148 ifp->if_oerrors = 0; 149 ifp->if_ipackets = 0; 150 ifp->if_opackets = 0; 151 ifp->if_dlt = DLT_NULL; 152 IFQ_SET_READY(&ifp->if_snd); 153 if_attach(ifp); 154 if_alloc_sadl(ifp); 155 #if NBPFILTER > 0 156 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 157 #endif 158 } 159 160 void 161 tun_clone_destroy(ifp) 162 struct ifnet *ifp; 163 { 164 struct tun_softc *tp = (void *)ifp; 165 struct proc *p; 166 167 simple_lock(&tun_softc_lock); 168 simple_lock(&tp->tun_lock); 169 LIST_REMOVE(tp, tun_list); 170 simple_unlock(&tp->tun_lock); 171 simple_unlock(&tun_softc_lock); 172 173 if (tp->tun_flags & TUN_RWAIT) { 174 tp->tun_flags &= ~TUN_RWAIT; 175 wakeup((caddr_t)tp); 176 } 177 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 178 if (tp->tun_pgrp > 0) 179 gsignal(tp->tun_pgrp, SIGIO); 180 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 181 psignal(p, SIGIO); 182 } 183 selwakeup(&tp->tun_rsel); 184 185 #if NBPFILTER > 0 186 bpfdetach(ifp); 187 #endif 188 if_detach(ifp); 189 190 free(tp, M_DEVBUF); 191 } 192 193 static struct tun_softc * 194 tun_find_unit(dev) 195 dev_t dev; 196 { 197 struct tun_softc *tp; 198 int unit = minor(dev); 199 200 simple_lock(&tun_softc_lock); 201 LIST_FOREACH(tp, &tun_softc_list, tun_list) 202 if (unit == tp->tun_unit) 203 break; 204 if (tp) 205 simple_lock(&tp->tun_lock); 206 simple_unlock(&tun_softc_lock); 207 208 return (tp); 209 } 210 211 /* 212 * tunnel open - must be superuser & the device must be 213 * configured in 214 */ 215 int 216 tunopen(dev, flag, mode, p) 217 dev_t dev; 218 int flag, mode; 219 struct proc *p; 220 { 221 struct ifnet *ifp; 222 struct tun_softc *tp; 223 int error; 224 225 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 226 return (error); 227 228 if (NTUN < 1) 229 return (ENXIO); 230 231 tp = tun_find_unit(dev); 232 233 if (!tp) { 234 (void)tun_clone_create(&tun_cloner, minor(dev)); 235 tp = tun_find_unit(dev); 236 } 237 238 if (!tp) 239 return (ENXIO); 240 241 if (tp->tun_flags & TUN_OPEN) { 242 simple_unlock(&tp->tun_lock); 243 return (EBUSY); 244 } 245 246 ifp = &tp->tun_if; 247 tp->tun_flags |= TUN_OPEN; 248 TUNDEBUG("%s: open\n", ifp->if_xname); 249 simple_unlock(&tp->tun_lock); 250 return (0); 251 } 252 253 /* 254 * tunclose - close the device - mark i/f down & delete 255 * routing info 256 */ 257 int 258 tunclose(dev, flag, mode, p) 259 dev_t dev; 260 int flag; 261 int mode; 262 struct proc *p; 263 { 264 int s; 265 struct tun_softc *tp; 266 struct ifnet *ifp; 267 268 tp = tun_find_unit(dev); 269 270 /* interface was "destroyed" before the close */ 271 if (tp == NULL) 272 return (0); 273 274 ifp = &tp->tun_if; 275 276 tp->tun_flags &= ~TUN_OPEN; 277 278 /* 279 * junk all pending output 280 */ 281 s = splnet(); 282 IFQ_PURGE(&ifp->if_snd); 283 splx(s); 284 285 if (ifp->if_flags & IFF_UP) { 286 s = splnet(); 287 if_down(ifp); 288 if (ifp->if_flags & IFF_RUNNING) { 289 /* find internet addresses and delete routes */ 290 struct ifaddr *ifa; 291 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 292 #ifdef INET 293 if (ifa->ifa_addr->sa_family == AF_INET) { 294 rtinit(ifa, (int)RTM_DELETE, 295 tp->tun_flags & TUN_DSTADDR 296 ? RTF_HOST 297 : 0); 298 } 299 #endif 300 } 301 } 302 splx(s); 303 } 304 tp->tun_pgrp = 0; 305 selwakeup(&tp->tun_rsel); 306 307 TUNDEBUG ("%s: closed\n", ifp->if_xname); 308 simple_unlock(&tp->tun_lock); 309 return (0); 310 } 311 312 static void 313 tuninit(tp) 314 struct tun_softc *tp; 315 { 316 struct ifnet *ifp = &tp->tun_if; 317 struct ifaddr *ifa; 318 319 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 320 321 ifp->if_flags |= IFF_UP | IFF_RUNNING; 322 323 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 324 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 325 #ifdef INET 326 if (ifa->ifa_addr->sa_family == AF_INET) { 327 struct sockaddr_in *sin; 328 329 sin = satosin(ifa->ifa_addr); 330 if (sin && sin->sin_addr.s_addr) 331 tp->tun_flags |= TUN_IASET; 332 333 if (ifp->if_flags & IFF_POINTOPOINT) { 334 sin = satosin(ifa->ifa_dstaddr); 335 if (sin && sin->sin_addr.s_addr) 336 tp->tun_flags |= TUN_DSTADDR; 337 } 338 } 339 #endif 340 } 341 342 return; 343 } 344 345 /* 346 * Process an ioctl request. 347 */ 348 int 349 tun_ioctl(ifp, cmd, data) 350 struct ifnet *ifp; 351 u_long cmd; 352 caddr_t data; 353 { 354 int error = 0, s; 355 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 356 357 simple_lock(&tp->tun_lock); 358 359 s = splnet(); 360 switch(cmd) { 361 case SIOCSIFADDR: 362 tuninit((struct tun_softc *)(ifp->if_softc)); 363 TUNDEBUG("%s: address set\n", ifp->if_xname); 364 break; 365 case SIOCSIFDSTADDR: 366 tuninit((struct tun_softc *)(ifp->if_softc)); 367 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 368 break; 369 case SIOCSIFBRDADDR: 370 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 371 break; 372 case SIOCSIFMTU: { 373 struct ifreq *ifr = (struct ifreq *) data; 374 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 375 error = EINVAL; 376 break; 377 } 378 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 379 ifp->if_mtu = ifr->ifr_mtu; 380 break; 381 } 382 case SIOCADDMULTI: 383 case SIOCDELMULTI: { 384 struct ifreq *ifr = (struct ifreq *) data; 385 if (ifr == 0) { 386 error = EAFNOSUPPORT; /* XXX */ 387 break; 388 } 389 switch (ifr->ifr_addr.sa_family) { 390 391 #ifdef INET 392 case AF_INET: 393 break; 394 #endif 395 396 default: 397 error = EAFNOSUPPORT; 398 break; 399 } 400 break; 401 } 402 case SIOCSIFFLAGS: 403 break; 404 default: 405 error = EINVAL; 406 } 407 splx(s); 408 simple_unlock(&tp->tun_lock); 409 return (error); 410 } 411 412 /* 413 * tun_output - queue packets from higher level ready to put out. 414 */ 415 int 416 tun_output(ifp, m0, dst, rt) 417 struct ifnet *ifp; 418 struct mbuf *m0; 419 struct sockaddr *dst; 420 struct rtentry *rt; 421 { 422 struct tun_softc *tp = ifp->if_softc; 423 struct proc *p; 424 #ifdef INET 425 int s; 426 int error; 427 #endif 428 ALTQ_DECL(struct altq_pktattr pktattr;) 429 430 simple_lock(&tp->tun_lock); 431 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 432 433 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 434 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 435 tp->tun_flags); 436 m_freem (m0); 437 simple_unlock(&tp->tun_lock); 438 return (EHOSTDOWN); 439 } 440 441 /* 442 * if the queueing discipline needs packet classification, 443 * do it before prepending link headers. 444 */ 445 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 446 447 #if NBPFILTER > 0 448 if (ifp->if_bpf) { 449 /* 450 * We need to prepend the address family as 451 * a four byte field. Cons up a dummy header 452 * to pacify bpf. This is safe because bpf 453 * will only read from the mbuf (i.e., it won't 454 * try to free it or keep a pointer to it). 455 */ 456 struct mbuf m; 457 u_int32_t af = dst->sa_family; 458 459 m.m_next = m0; 460 m.m_len = sizeof(af); 461 m.m_data = (char *)⁡ 462 463 bpf_mtap(ifp->if_bpf, &m); 464 } 465 #endif 466 467 switch(dst->sa_family) { 468 #ifdef INET 469 case AF_INET: 470 if (tp->tun_flags & TUN_PREPADDR) { 471 /* Simple link-layer header */ 472 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 473 if (m0 == NULL) { 474 IF_DROP(&ifp->if_snd); 475 simple_unlock(&tp->tun_lock); 476 return (ENOBUFS); 477 } 478 bcopy(dst, mtod(m0, char *), dst->sa_len); 479 } 480 /* FALLTHROUGH */ 481 case AF_UNSPEC: 482 s = splnet(); 483 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 484 if (error) { 485 splx(s); 486 ifp->if_collisions++; 487 return (error); 488 } 489 splx(s); 490 ifp->if_opackets++; 491 break; 492 #endif 493 default: 494 m_freem(m0); 495 simple_unlock(&tp->tun_lock); 496 return (EAFNOSUPPORT); 497 } 498 499 if (tp->tun_flags & TUN_RWAIT) { 500 tp->tun_flags &= ~TUN_RWAIT; 501 wakeup((caddr_t)tp); 502 } 503 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 504 if (tp->tun_pgrp > 0) 505 gsignal(tp->tun_pgrp, SIGIO); 506 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 507 psignal(p, SIGIO); 508 } 509 selwakeup(&tp->tun_rsel); 510 simple_unlock(&tp->tun_lock); 511 return (0); 512 } 513 514 /* 515 * the cdevsw interface is now pretty minimal. 516 */ 517 int 518 tunioctl(dev, cmd, data, flag, p) 519 dev_t dev; 520 u_long cmd; 521 caddr_t data; 522 int flag; 523 struct proc *p; 524 { 525 int s; 526 struct tun_softc *tp; 527 528 tp = tun_find_unit(dev); 529 530 /* interface was "destroyed" already */ 531 if (tp == NULL) 532 return (ENXIO); 533 534 switch (cmd) { 535 case TUNSDEBUG: 536 tundebug = *(int *)data; 537 break; 538 539 case TUNGDEBUG: 540 *(int *)data = tundebug; 541 break; 542 543 case TUNSIFMODE: 544 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 545 case IFF_POINTOPOINT: 546 case IFF_BROADCAST: 547 s = splnet(); 548 if (tp->tun_if.if_flags & IFF_UP) { 549 splx(s); 550 simple_unlock(&tp->tun_lock); 551 return (EBUSY); 552 } 553 tp->tun_if.if_flags &= 554 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 555 tp->tun_if.if_flags |= *(int *)data; 556 splx(s); 557 break; 558 default: 559 simple_unlock(&tp->tun_lock); 560 return (EINVAL); 561 break; 562 } 563 break; 564 565 case TUNSLMODE: 566 if (*(int *)data) 567 tp->tun_flags |= TUN_PREPADDR; 568 else 569 tp->tun_flags &= ~TUN_PREPADDR; 570 break; 571 572 case FIONBIO: 573 if (*(int *)data) 574 tp->tun_flags |= TUN_NBIO; 575 else 576 tp->tun_flags &= ~TUN_NBIO; 577 break; 578 579 case FIOASYNC: 580 if (*(int *)data) 581 tp->tun_flags |= TUN_ASYNC; 582 else 583 tp->tun_flags &= ~TUN_ASYNC; 584 break; 585 586 case FIONREAD: 587 s = splnet(); 588 if (tp->tun_if.if_snd.ifq_head) 589 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 590 else 591 *(int *)data = 0; 592 splx(s); 593 break; 594 595 case TIOCSPGRP: 596 tp->tun_pgrp = *(int *)data; 597 break; 598 599 case TIOCGPGRP: 600 *(int *)data = tp->tun_pgrp; 601 break; 602 603 default: 604 simple_unlock(&tp->tun_lock); 605 return (ENOTTY); 606 } 607 simple_unlock(&tp->tun_lock); 608 return (0); 609 } 610 611 /* 612 * The cdevsw read interface - reads a packet at a time, or at 613 * least as much of a packet as can be read. 614 */ 615 int 616 tunread(dev, uio, ioflag) 617 dev_t dev; 618 struct uio *uio; 619 int ioflag; 620 { 621 struct tun_softc *tp; 622 struct ifnet *ifp; 623 struct mbuf *m, *m0; 624 int error=0, len, s, index; 625 626 tp = tun_find_unit(dev); 627 628 /* interface was "destroyed" already */ 629 if (tp == NULL) 630 return (ENXIO); 631 632 index = tp->tun_if.if_index; 633 ifp = &tp->tun_if; 634 635 TUNDEBUG ("%s: read\n", ifp->if_xname); 636 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 637 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 638 simple_unlock(&tp->tun_lock); 639 return EHOSTDOWN; 640 } 641 642 tp->tun_flags &= ~TUN_RWAIT; 643 644 s = splnet(); 645 do { 646 IFQ_DEQUEUE(&ifp->if_snd, m0); 647 if (m0 == 0) { 648 if (tp->tun_flags & TUN_NBIO) { 649 splx(s); 650 simple_unlock(&tp->tun_lock); 651 return (EWOULDBLOCK); 652 } 653 tp->tun_flags |= TUN_RWAIT; 654 simple_unlock(&tp->tun_lock); 655 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 656 splx(s); 657 return (EINTR); 658 } else { 659 /* 660 * Maybe the interface was destroyed while 661 * we were sleeping, so let's ensure that 662 * we're looking at the same (valid) tun 663 * interface before looping. 664 */ 665 tp = tun_find_unit(dev); 666 if (tp == NULL || 667 tp->tun_if.if_index != index) { 668 splx(s); 669 if (tp) 670 simple_unlock(&tp->tun_lock); 671 return (ENXIO); 672 } 673 } 674 } 675 } while (m0 == 0); 676 splx(s); 677 678 while (m0 && uio->uio_resid > 0 && error == 0) { 679 len = min(uio->uio_resid, m0->m_len); 680 if (len != 0) 681 error = uiomove(mtod(m0, caddr_t), len, uio); 682 MFREE(m0, m); 683 m0 = m; 684 } 685 686 if (m0) { 687 TUNDEBUG("Dropping mbuf\n"); 688 m_freem(m0); 689 } 690 if (error) 691 ifp->if_ierrors++; 692 simple_unlock(&tp->tun_lock); 693 return (error); 694 } 695 696 /* 697 * the cdevsw write interface - an atomic write is a packet - or else! 698 */ 699 int 700 tunwrite(dev, uio, ioflag) 701 dev_t dev; 702 struct uio *uio; 703 int ioflag; 704 { 705 struct tun_softc *tp; 706 struct ifnet *ifp; 707 struct mbuf *top, **mp, *m; 708 struct ifqueue *ifq; 709 struct sockaddr dst; 710 int isr, error=0, s, tlen, mlen; 711 712 tp = tun_find_unit(dev); 713 714 /* interface was "destroyed" already */ 715 if (tp == NULL) 716 return (ENXIO); 717 718 ifp = &tp->tun_if; 719 720 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 721 722 if (tp->tun_flags & TUN_PREPADDR) { 723 if (uio->uio_resid < sizeof(dst)) { 724 simple_unlock(&tp->tun_lock); 725 return (EIO); 726 } 727 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 728 if (dst.sa_len > sizeof(dst)) { 729 /* Duh.. */ 730 char discard; 731 int n = dst.sa_len - sizeof(dst); 732 while (n--) 733 if ((error = uiomove(&discard, 1, uio)) != 0) { 734 simple_unlock(&tp->tun_lock); 735 return (error); 736 } 737 } 738 } else { 739 #ifdef INET 740 dst.sa_family = AF_INET; 741 #endif 742 } 743 744 if (uio->uio_resid < 0 || uio->uio_resid > TUNMTU) { 745 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 746 (unsigned long)uio->uio_resid); 747 simple_unlock(&tp->tun_lock); 748 return (EIO); 749 } 750 751 switch (dst.sa_family) { 752 #ifdef INET 753 case AF_INET: 754 ifq = &ipintrq; 755 isr = NETISR_IP; 756 break; 757 #endif 758 default: 759 simple_unlock(&tp->tun_lock); 760 return (EAFNOSUPPORT); 761 } 762 763 tlen = uio->uio_resid; 764 765 /* get a header mbuf */ 766 MGETHDR(m, M_DONTWAIT, MT_DATA); 767 if (m == NULL) { 768 simple_unlock(&tp->tun_lock); 769 return (ENOBUFS); 770 } 771 mlen = MHLEN; 772 773 top = 0; 774 mp = ⊤ 775 while (error == 0 && uio->uio_resid > 0) { 776 m->m_len = min(mlen, uio->uio_resid); 777 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 778 *mp = m; 779 mp = &m->m_next; 780 if (uio->uio_resid > 0) { 781 MGET (m, M_DONTWAIT, MT_DATA); 782 if (m == 0) { 783 error = ENOBUFS; 784 break; 785 } 786 mlen = MLEN; 787 } 788 } 789 if (error) { 790 if (top) 791 m_freem (top); 792 ifp->if_ierrors++; 793 simple_unlock(&tp->tun_lock); 794 return (error); 795 } 796 797 top->m_pkthdr.len = tlen; 798 top->m_pkthdr.rcvif = ifp; 799 800 #if NBPFILTER > 0 801 if (ifp->if_bpf) { 802 /* 803 * We need to prepend the address family as 804 * a four byte field. Cons up a dummy header 805 * to pacify bpf. This is safe because bpf 806 * will only read from the mbuf (i.e., it won't 807 * try to free it or keep a pointer to it). 808 */ 809 struct mbuf m; 810 u_int32_t af = AF_INET; 811 812 m.m_next = top; 813 m.m_len = sizeof(af); 814 m.m_data = (char *)⁡ 815 816 bpf_mtap(ifp->if_bpf, &m); 817 } 818 #endif 819 820 s = splnet(); 821 if (IF_QFULL(ifq)) { 822 IF_DROP(ifq); 823 splx(s); 824 ifp->if_collisions++; 825 m_freem(top); 826 simple_unlock(&tp->tun_lock); 827 return (ENOBUFS); 828 } 829 IF_ENQUEUE(ifq, top); 830 splx(s); 831 ifp->if_ipackets++; 832 schednetisr(isr); 833 simple_unlock(&tp->tun_lock); 834 return (error); 835 } 836 837 #ifdef ALTQ 838 /* 839 * Start packet transmission on the interface. 840 * when the interface queue is rate-limited by ALTQ or TBR, 841 * if_start is needed to drain packets from the queue in order 842 * to notify readers when outgoing packets become ready. 843 */ 844 static void 845 tunstart(ifp) 846 struct ifnet *ifp; 847 { 848 struct tun_softc *tp = ifp->if_softc; 849 struct mbuf *m; 850 struct proc *p; 851 852 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 853 return; 854 855 IFQ_POLL(&ifp->if_snd, m); 856 if (m != NULL) { 857 if (tp->tun_flags & TUN_RWAIT) { 858 tp->tun_flags &= ~TUN_RWAIT; 859 wakeup((caddr_t)tp); 860 } 861 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 862 if (tp->tun_pgrp > 0) 863 gsignal(tp->tun_pgrp, SIGIO); 864 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 865 psignal(p, SIGIO); 866 } 867 selwakeup(&tp->tun_rsel); 868 } 869 } 870 #endif /* ALTQ */ 871 /* 872 * tunpoll - the poll interface, this is only useful on reads 873 * really. The write detect always returns true, write never blocks 874 * anyway, it either accepts the packet or drops it. 875 */ 876 int 877 tunpoll(dev, events, p) 878 dev_t dev; 879 int events; 880 struct proc *p; 881 { 882 struct tun_softc *tp; 883 struct ifnet *ifp; 884 int s, revents = 0; 885 886 tp = tun_find_unit(dev); 887 888 /* interface was "destroyed" already */ 889 if (tp == NULL) 890 return (0); 891 892 ifp = &tp->tun_if; 893 894 s = splnet(); 895 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 896 897 if (events & (POLLIN | POLLRDNORM)) { 898 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 899 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 900 ifp->if_snd.ifq_len); 901 revents |= events & (POLLIN | POLLRDNORM); 902 } else { 903 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 904 selrecord(p, &tp->tun_rsel); 905 } 906 } 907 908 if (events & (POLLOUT | POLLWRNORM)) 909 revents |= events & (POLLOUT | POLLWRNORM); 910 911 splx(s); 912 simple_unlock(&tp->tun_lock); 913 return (revents); 914 } 915
Indexes created Wed Sep 24 15:09:51 GMT 2025