1 /* 2 * Copyright (C) 1999-2000 by Maksim Yevmenkin <m_evmenkin@yahoo.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * BASED ON: 27 * ------------------------------------------------------------------------- 28 * 29 * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk> 30 * Nottingham University 1987. 31 */ 32 33 /* 34 * $FreeBSD: src/sys/net/if_tap.c,v 1.3.2.3 2002/04/14 21:41:48 luigi Exp $ 35 * $DragonFly: src/sys/net/tap/if_tap.c,v 1.14 2004/06/02 14:42:59 eirikn Exp $ 36 * $Id: if_tap.c,v 0.21 2000/07/23 21:46:02 max Exp $ 37 */ 38 39 #include "opt_inet.h" 40 41 #include <sys/param.h> 42 #include <sys/conf.h> 43 #include <sys/filedesc.h> 44 #include <sys/filio.h> 45 #include <sys/kernel.h> 46 #include <sys/malloc.h> 47 #include <sys/mbuf.h> 48 #include <sys/poll.h> 49 #include <sys/proc.h> 50 #include <sys/signalvar.h> 51 #include <sys/socket.h> 52 #include <sys/sockio.h> 53 #include <sys/sysctl.h> 54 #include <sys/systm.h> 55 #include <sys/ttycom.h> 56 #include <sys/uio.h> 57 #include <sys/vnode.h> 58 59 #include <net/bpf.h> 60 #include <net/ethernet.h> 61 #include <net/if.h> 62 #include <net/if_arp.h> 63 #include <net/route.h> 64 65 #include <netinet/in.h> 66 67 #include "if_tapvar.h" 68 #include "if_tap.h" 69 70 71 #define CDEV_NAME "tap" 72 #define CDEV_MAJOR 149 73 #define TAPDEBUG if (tapdebug) printf 74 75 #define TAP "tap" 76 #define VMNET "vmnet" 77 #define VMNET_DEV_MASK 0x00010000 78 79 /* module */ 80 static int tapmodevent (module_t, int, void *); 81 82 /* device */ 83 static void tapcreate (dev_t); 84 85 /* network interface */ 86 static void tapifstart (struct ifnet *); 87 static int tapifioctl (struct ifnet *, u_long, caddr_t, 88 struct ucred *); 89 static void tapifinit (void *); 90 91 /* character device */ 92 static d_open_t tapopen; 93 static d_close_t tapclose; 94 static d_read_t tapread; 95 static d_write_t tapwrite; 96 static d_ioctl_t tapioctl; 97 static d_poll_t tappoll; 98 99 static struct cdevsw tap_cdevsw = { 100 /* dev name */ CDEV_NAME, 101 /* dev major */ CDEV_MAJOR, 102 /* flags */ 0, 103 /* port */ NULL, 104 /* clone */ NULL, 105 106 /* open */ tapopen, 107 /* close */ tapclose, 108 /* read */ tapread, 109 /* write */ tapwrite, 110 /* ioctl */ tapioctl, 111 /* poll */ tappoll, 112 /* mmap */ nommap, 113 /* startegy */ nostrategy, 114 /* dump */ nodump, 115 /* psize */ nopsize 116 }; 117 118 static int taprefcnt = 0; /* module ref. counter */ 119 static int taplastunit = -1; /* max. open unit number */ 120 static int tapdebug = 0; /* debug flag */ 121 122 MALLOC_DECLARE(M_TAP); 123 MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface"); 124 SYSCTL_INT(_debug, OID_AUTO, if_tap_debug, CTLFLAG_RW, &tapdebug, 0, ""); 125 DEV_MODULE(if_tap, tapmodevent, NULL); 126 127 /* 128 * tapmodevent 129 * 130 * module event handler 131 */ 132 static int 133 tapmodevent(mod, type, data) 134 module_t mod; 135 int type; 136 void *data; 137 { 138 static int attached = 0; 139 struct ifnet *ifp = NULL; 140 int unit, s; 141 142 switch (type) { 143 case MOD_LOAD: 144 if (attached) 145 return (EEXIST); 146 147 cdevsw_add(&tap_cdevsw, 0, 0); 148 attached = 1; 149 break; 150 151 case MOD_UNLOAD: 152 if (taprefcnt > 0) 153 return (EBUSY); 154 155 cdevsw_remove(&tap_cdevsw, 0, 0); 156 157 /* XXX: maintain tap ifs in a local list */ 158 unit = 0; 159 while (unit <= taplastunit) { 160 s = splimp(); 161 TAILQ_FOREACH(ifp, &ifnet, if_link) 162 if ((strcmp(ifp->if_dname, TAP) == 0) || 163 (strcmp(ifp->if_dname, VMNET) == 0)) 164 if (ifp->if_dunit == unit) 165 break; 166 splx(s); 167 168 if (ifp != NULL) { 169 struct tap_softc *tp = ifp->if_softc; 170 171 TAPDEBUG("detaching %s. minor = %#x, " \ 172 "taplastunit = %d\n", 173 ifp->if_xname, minor(tp->tap_dev), 174 taplastunit); 175 176 s = splimp(); 177 ether_ifdetach(ifp); 178 splx(s); 179 destroy_dev(tp->tap_dev); 180 free(tp, M_TAP); 181 } 182 else 183 unit ++; 184 } 185 186 attached = 0; 187 break; 188 189 default: 190 return (EOPNOTSUPP); 191 } 192 193 return (0); 194 } /* tapmodevent */ 195 196 197 /* 198 * tapcreate 199 * 200 * to create interface 201 */ 202 static void 203 tapcreate(dev) 204 dev_t dev; 205 { 206 struct ifnet *ifp = NULL; 207 struct tap_softc *tp = NULL; 208 uint8_t ether_addr[ETHER_ADDR_LEN]; 209 int unit, s; 210 char *name = NULL; 211 212 /* allocate driver storage and create device */ 213 MALLOC(tp, struct tap_softc *, sizeof(*tp), M_TAP, M_WAITOK); 214 bzero(tp, sizeof(*tp)); 215 216 /* select device: tap or vmnet */ 217 if (minor(dev) & VMNET_DEV_MASK) { 218 name = VMNET; 219 unit = lminor(dev) & 0xff; 220 tp->tap_flags |= TAP_VMNET; 221 } 222 else { 223 name = TAP; 224 unit = lminor(dev); 225 } 226 227 tp->tap_dev = make_dev(&tap_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 228 0600, "%s%d", name, unit); 229 tp->tap_dev->si_drv1 = dev->si_drv1 = tp; 230 reference_dev(tp->tap_dev); /* so we can destroy it later */ 231 232 /* generate fake MAC address: 00 bd xx xx xx unit_no */ 233 ether_addr[0] = 0x00; 234 ether_addr[1] = 0xbd; 235 bcopy(&ticks, ether_addr, 4); 236 ether_addr[5] = (u_char)unit; 237 238 /* fill the rest and attach interface */ 239 ifp = &tp->tap_if; 240 ifp->if_softc = tp; 241 242 if_initname(ifp, name, unit); 243 if (unit > taplastunit) 244 taplastunit = unit; 245 246 ifp->if_init = tapifinit; 247 ifp->if_output = ether_output; 248 ifp->if_start = tapifstart; 249 ifp->if_ioctl = tapifioctl; 250 ifp->if_mtu = ETHERMTU; 251 ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST); 252 ifp->if_snd.ifq_maxlen = ifqmaxlen; 253 254 s = splimp(); 255 ether_ifattach(ifp, ether_addr); 256 splx(s); 257 258 tp->tap_flags |= TAP_INITED; 259 260 TAPDEBUG("interface %s created. minor = %#x\n", 261 ifp->if_xname, minor(tp->tap_dev)); 262 } /* tapcreate */ 263 264 265 /* 266 * tapopen 267 * 268 * to open tunnel. must be superuser 269 */ 270 static int 271 tapopen(dev_t dev, int flag, int mode, d_thread_t *td) 272 { 273 struct tap_softc *tp = NULL; 274 int error; 275 276 KKASSERT(p != NULL); 277 278 if ((error = suser(td)) != 0) 279 return (error); 280 281 tp = dev->si_drv1; 282 if (tp == NULL) { 283 tapcreate(dev); 284 tp = dev->si_drv1; 285 } 286 287 if (tp->tap_flags & TAP_OPEN) 288 return (EBUSY); 289 290 bcopy(tp->arpcom.ac_enaddr, tp->ether_addr, sizeof(tp->ether_addr)); 291 292 tp->tap_td = td; 293 tp->tap_flags |= TAP_OPEN; 294 taprefcnt ++; 295 296 TAPDEBUG("%s is open. minor = %#x, refcnt = %d, taplastunit = %d\n", 297 tp->tap_if.if_xname, 298 minor(tp->tap_dev), taprefcnt, taplastunit); 299 300 return (0); 301 } /* tapopen */ 302 303 304 /* 305 * tapclose 306 * 307 * close the device - mark i/f down & delete routing info 308 */ 309 static int 310 tapclose(dev_t dev, int foo, int bar, d_thread_t *td) 311 { 312 int s; 313 struct tap_softc *tp = dev->si_drv1; 314 struct ifnet *ifp = &tp->tap_if; 315 struct mbuf *m = NULL; 316 317 /* junk all pending output */ 318 319 s = splimp(); 320 do { 321 IF_DEQUEUE(&ifp->if_snd, m); 322 if (m != NULL) 323 m_freem(m); 324 } while (m != NULL); 325 splx(s); 326 327 /* 328 * do not bring the interface down, and do not anything with 329 * interface, if we are in VMnet mode. just close the device. 330 */ 331 332 if (((tp->tap_flags & TAP_VMNET) == 0) && (ifp->if_flags & IFF_UP)) { 333 s = splimp(); 334 if_down(ifp); 335 if (ifp->if_flags & IFF_RUNNING) { 336 /* find internet addresses and delete routes */ 337 struct ifaddr *ifa = NULL; 338 339 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 340 if (ifa->ifa_addr->sa_family == AF_INET) { 341 rtinit(ifa, (int)RTM_DELETE, 0); 342 343 /* remove address from interface */ 344 bzero(ifa->ifa_addr, 345 sizeof(*(ifa->ifa_addr))); 346 bzero(ifa->ifa_dstaddr, 347 sizeof(*(ifa->ifa_dstaddr))); 348 bzero(ifa->ifa_netmask, 349 sizeof(*(ifa->ifa_netmask))); 350 } 351 } 352 353 ifp->if_flags &= ~IFF_RUNNING; 354 } 355 splx(s); 356 } 357 358 funsetown(tp->tap_sigio); 359 selwakeup(&tp->tap_rsel); 360 361 tp->tap_flags &= ~TAP_OPEN; 362 tp->tap_td = NULL; 363 364 taprefcnt --; 365 if (taprefcnt < 0) { 366 taprefcnt = 0; 367 printf("%s minor = %#x, refcnt = %d is out of sync. " \ 368 "set refcnt to 0\n", ifp->if_xname, 369 minor(tp->tap_dev), taprefcnt); 370 } 371 372 TAPDEBUG("%s is closed. minor = %#x, refcnt = %d, taplastunit = %d\n", 373 ifp->if_xname, minor(tp->tap_dev), 374 taprefcnt, taplastunit); 375 376 return (0); 377 } /* tapclose */ 378 379 380 /* 381 * tapifinit 382 * 383 * network interface initialization function 384 */ 385 static void 386 tapifinit(xtp) 387 void *xtp; 388 { 389 struct tap_softc *tp = (struct tap_softc *)xtp; 390 struct ifnet *ifp = &tp->tap_if; 391 392 TAPDEBUG("initializing %s, minor = %#x\n", 393 ifp->if_xname, minor(tp->tap_dev)); 394 395 ifp->if_flags |= IFF_RUNNING; 396 ifp->if_flags &= ~IFF_OACTIVE; 397 398 /* attempt to start output */ 399 tapifstart(ifp); 400 } /* tapifinit */ 401 402 403 /* 404 * tapifioctl 405 * 406 * Process an ioctl request on network interface 407 */ 408 int 409 tapifioctl(ifp, cmd, data, cr) 410 struct ifnet *ifp; 411 u_long cmd; 412 caddr_t data; 413 struct ucred *cr; 414 { 415 struct tap_softc *tp = (struct tap_softc *)(ifp->if_softc); 416 struct ifstat *ifs = NULL; 417 int s, dummy; 418 419 switch (cmd) { 420 case SIOCSIFADDR: 421 case SIOCGIFADDR: 422 case SIOCSIFMTU: 423 s = splimp(); 424 dummy = ether_ioctl(ifp, cmd, data); 425 splx(s); 426 return (dummy); 427 428 case SIOCSIFFLAGS: /* XXX -- just like vmnet does */ 429 case SIOCADDMULTI: 430 case SIOCDELMULTI: 431 break; 432 433 case SIOCGIFSTATUS: 434 s = splimp(); 435 ifs = (struct ifstat *)data; 436 dummy = strlen(ifs->ascii); 437 if (tp->tap_td != NULL && dummy < sizeof(ifs->ascii)) { 438 if (tp->tap_td->td_proc) { 439 snprintf(ifs->ascii + dummy, 440 sizeof(ifs->ascii) - dummy, 441 "\tOpened by pid %d\n", 442 (int)tp->tap_td->td_proc->p_pid); 443 } else { 444 snprintf(ifs->ascii + dummy, 445 sizeof(ifs->ascii) - dummy, 446 "\tOpened by td %p\n", tp->tap_td); 447 } 448 } 449 splx(s); 450 break; 451 452 default: 453 return (EINVAL); 454 } 455 456 return (0); 457 } /* tapifioctl */ 458 459 460 /* 461 * tapifstart 462 * 463 * queue packets from higher level ready to put out 464 */ 465 static void 466 tapifstart(ifp) 467 struct ifnet *ifp; 468 { 469 struct tap_softc *tp = ifp->if_softc; 470 int s; 471 472 TAPDEBUG("%s starting, minor = %#x\n", 473 ifp->if_xname, minor(tp->tap_dev)); 474 475 /* 476 * do not junk pending output if we are in VMnet mode. 477 * XXX: can this do any harm because of queue overflow? 478 */ 479 480 if (((tp->tap_flags & TAP_VMNET) == 0) && 481 ((tp->tap_flags & TAP_READY) != TAP_READY)) { 482 struct mbuf *m = NULL; 483 484 TAPDEBUG("%s not ready. minor = %#x, tap_flags = 0x%x\n", 485 ifp->if_xname, 486 minor(tp->tap_dev), tp->tap_flags); 487 488 s = splimp(); 489 do { 490 IF_DEQUEUE(&ifp->if_snd, m); 491 if (m != NULL) 492 m_freem(m); 493 ifp->if_oerrors ++; 494 } while (m != NULL); 495 splx(s); 496 497 return; 498 } 499 500 s = splimp(); 501 ifp->if_flags |= IFF_OACTIVE; 502 503 if (ifp->if_snd.ifq_len != 0) { 504 if (tp->tap_flags & TAP_RWAIT) { 505 tp->tap_flags &= ~TAP_RWAIT; 506 wakeup((caddr_t)tp); 507 } 508 509 if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL)) 510 pgsigio(tp->tap_sigio, SIGIO, 0); 511 512 selwakeup(&tp->tap_rsel); 513 ifp->if_opackets ++; /* obytes are counted in ether_output */ 514 } 515 516 ifp->if_flags &= ~IFF_OACTIVE; 517 splx(s); 518 } /* tapifstart */ 519 520 521 /* 522 * tapioctl 523 * 524 * the cdevsw interface is now pretty minimal 525 */ 526 static int 527 tapioctl(dev_t dev, u_long cmd, caddr_t data, int flag, d_thread_t *td) 528 { 529 struct tap_softc *tp = dev->si_drv1; 530 struct ifnet *ifp = &tp->tap_if; 531 struct tapinfo *tapp = NULL; 532 int s; 533 534 switch (cmd) { 535 case TAPSIFINFO: 536 s = splimp(); 537 tapp = (struct tapinfo *)data; 538 ifp->if_mtu = tapp->mtu; 539 ifp->if_type = tapp->type; 540 ifp->if_baudrate = tapp->baudrate; 541 splx(s); 542 break; 543 544 case TAPGIFINFO: 545 tapp = (struct tapinfo *)data; 546 tapp->mtu = ifp->if_mtu; 547 tapp->type = ifp->if_type; 548 tapp->baudrate = ifp->if_baudrate; 549 break; 550 551 case TAPSDEBUG: 552 tapdebug = *(int *)data; 553 break; 554 555 case TAPGDEBUG: 556 *(int *)data = tapdebug; 557 break; 558 559 case FIONBIO: 560 break; 561 562 case FIOASYNC: 563 s = splimp(); 564 if (*(int *)data) 565 tp->tap_flags |= TAP_ASYNC; 566 else 567 tp->tap_flags &= ~TAP_ASYNC; 568 splx(s); 569 break; 570 571 case FIONREAD: 572 s = splimp(); 573 if (ifp->if_snd.ifq_head) { 574 struct mbuf *mb = ifp->if_snd.ifq_head; 575 576 for(*(int *)data = 0;mb != NULL;mb = mb->m_next) 577 *(int *)data += mb->m_len; 578 } 579 else 580 *(int *)data = 0; 581 splx(s); 582 break; 583 584 case FIOSETOWN: 585 return (fsetown(*(int *)data, &tp->tap_sigio)); 586 587 case FIOGETOWN: 588 *(int *)data = fgetown(tp->tap_sigio); 589 return (0); 590 591 /* this is deprecated, FIOSETOWN should be used instead */ 592 case TIOCSPGRP: 593 return (fsetown(-(*(int *)data), &tp->tap_sigio)); 594 595 /* this is deprecated, FIOGETOWN should be used instead */ 596 case TIOCGPGRP: 597 *(int *)data = -fgetown(tp->tap_sigio); 598 return (0); 599 600 /* VMware/VMnet port ioctl's */ 601 602 case SIOCGIFFLAGS: /* get ifnet flags */ 603 bcopy(&ifp->if_flags, data, sizeof(ifp->if_flags)); 604 break; 605 606 case VMIO_SIOCSIFFLAGS: { /* VMware/VMnet SIOCSIFFLAGS */ 607 short f = *(short *)data; 608 609 f &= 0x0fff; 610 f &= ~IFF_CANTCHANGE; 611 f |= IFF_UP; 612 613 s = splimp(); 614 ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE); 615 splx(s); 616 } break; 617 618 case OSIOCGIFADDR: /* get MAC address of the remote side */ 619 case SIOCGIFADDR: 620 bcopy(tp->ether_addr, data, sizeof(tp->ether_addr)); 621 break; 622 623 case SIOCSIFADDR: /* set MAC address of the remote side */ 624 bcopy(data, tp->ether_addr, sizeof(tp->ether_addr)); 625 break; 626 627 default: 628 return (ENOTTY); 629 } 630 return (0); 631 } /* tapioctl */ 632 633 634 /* 635 * tapread 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 static int 641 tapread(dev, uio, flag) 642 dev_t dev; 643 struct uio *uio; 644 int flag; 645 { 646 struct tap_softc *tp = dev->si_drv1; 647 struct ifnet *ifp = &tp->tap_if; 648 struct mbuf *m0 = NULL; 649 int error = 0, len, s; 650 651 TAPDEBUG("%s reading, minor = %#x\n", 652 ifp->if_xname, minor(tp->tap_dev)); 653 654 if ((tp->tap_flags & TAP_READY) != TAP_READY) { 655 TAPDEBUG("%s not ready. minor = %#x, tap_flags = 0x%x\n", 656 ifp->if_xname, 657 minor(tp->tap_dev), tp->tap_flags); 658 659 return (EHOSTDOWN); 660 } 661 662 tp->tap_flags &= ~TAP_RWAIT; 663 664 /* sleep until we get a packet */ 665 do { 666 s = splimp(); 667 IF_DEQUEUE(&ifp->if_snd, m0); 668 splx(s); 669 670 if (m0 == NULL) { 671 if (flag & IO_NDELAY) 672 return (EWOULDBLOCK); 673 674 tp->tap_flags |= TAP_RWAIT; 675 error = tsleep((caddr_t)tp, PCATCH, "taprd", 0); 676 if (error) 677 return (error); 678 } 679 } while (m0 == NULL); 680 681 /* feed packet to bpf */ 682 if (ifp->if_bpf != NULL) 683 bpf_mtap(ifp, m0); 684 685 /* xfer packet to user space */ 686 while ((m0 != NULL) && (uio->uio_resid > 0) && (error == 0)) { 687 len = min(uio->uio_resid, m0->m_len); 688 if (len == 0) 689 break; 690 691 error = uiomove(mtod(m0, caddr_t), len, uio); 692 m0 = m_free(m0); 693 } 694 695 if (m0 != NULL) { 696 TAPDEBUG("%s dropping mbuf, minor = %#x\n", 697 ifp->if_xname, minor(tp->tap_dev)); 698 m_freem(m0); 699 } 700 701 return (error); 702 } /* tapread */ 703 704 705 /* 706 * tapwrite 707 * 708 * the cdevsw write interface - an atomic write is a packet - or else! 709 */ 710 static int 711 tapwrite(dev, uio, flag) 712 dev_t dev; 713 struct uio *uio; 714 int flag; 715 { 716 struct tap_softc *tp = dev->si_drv1; 717 struct ifnet *ifp = &tp->tap_if; 718 struct mbuf *top = NULL, **mp = NULL, *m = NULL; 719 struct ether_header *eh = NULL; 720 int error = 0, tlen, mlen; 721 722 TAPDEBUG("%s writting, minor = %#x\n", 723 ifp->if_xname, minor(tp->tap_dev)); 724 725 if (uio->uio_resid == 0) 726 return (0); 727 728 if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) { 729 TAPDEBUG("%s invalid packet len = %d, minor = %#x\n", 730 ifp->if_xname, 731 uio->uio_resid, minor(tp->tap_dev)); 732 733 return (EIO); 734 } 735 tlen = uio->uio_resid; 736 737 /* get a header mbuf */ 738 MGETHDR(m, MB_DONTWAIT, MT_DATA); 739 if (m == NULL) 740 return (ENOBUFS); 741 mlen = MHLEN; 742 743 top = 0; 744 mp = ⊤ 745 while ((error == 0) && (uio->uio_resid > 0)) { 746 m->m_len = min(mlen, uio->uio_resid); 747 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 748 *mp = m; 749 mp = &m->m_next; 750 if (uio->uio_resid > 0) { 751 MGET(m, MB_DONTWAIT, MT_DATA); 752 if (m == NULL) { 753 error = ENOBUFS; 754 break; 755 } 756 mlen = MLEN; 757 } 758 } 759 if (error) { 760 ifp->if_ierrors ++; 761 if (top) 762 m_freem(top); 763 return (error); 764 } 765 766 top->m_pkthdr.len = tlen; 767 top->m_pkthdr.rcvif = ifp; 768 769 /* 770 * Ethernet bridge and bpf are handled in ether_input 771 * 772 * adjust mbuf and give packet to the ether_input 773 */ 774 775 eh = mtod(top, struct ether_header *); 776 m_adj(top, sizeof(struct ether_header)); 777 ether_input(ifp, eh, top); 778 ifp->if_ipackets ++; /* ibytes are counted in ether_input */ 779 780 return (0); 781 } /* tapwrite */ 782 783 784 /* 785 * tappoll 786 * 787 * the poll interface, this is only useful on reads 788 * really. the write detect always returns true, write never blocks 789 * anyway, it either accepts the packet or drops it 790 */ 791 static int 792 tappoll(dev_t dev, int events, d_thread_t *td) 793 { 794 struct tap_softc *tp = dev->si_drv1; 795 struct ifnet *ifp = &tp->tap_if; 796 int s, revents = 0; 797 798 TAPDEBUG("%s polling, minor = %#x\n", 799 ifp->if_xname, minor(tp->tap_dev)); 800 801 s = splimp(); 802 if (events & (POLLIN | POLLRDNORM)) { 803 if (ifp->if_snd.ifq_len > 0) { 804 TAPDEBUG("%s have data in queue. len = %d, " \ 805 "minor = %#x\n", ifp->if_xname, 806 ifp->if_snd.ifq_len, minor(tp->tap_dev)); 807 808 revents |= (events & (POLLIN | POLLRDNORM)); 809 } 810 else { 811 TAPDEBUG("%s waiting for data, minor = %#x\n", 812 ifp->if_xname, minor(tp->tap_dev)); 813 814 selrecord(td, &tp->tap_rsel); 815 } 816 } 817 818 if (events & (POLLOUT | POLLWRNORM)) 819 revents |= (events & (POLLOUT | POLLWRNORM)); 820 821 splx(s); 822 return (revents); 823 } /* tappoll */ 824