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 1.8 2003/08/26 20:49:49 rob 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 static void tapifinit (void *); 89 90 /* character device */ 91 static d_open_t tapopen; 92 static d_close_t tapclose; 93 static d_read_t tapread; 94 static d_write_t tapwrite; 95 static d_ioctl_t tapioctl; 96 static d_poll_t tappoll; 97 98 static struct cdevsw tap_cdevsw = { 99 /* dev name */ CDEV_NAME, 100 /* dev major */ CDEV_MAJOR, 101 /* flags */ 0, 102 /* port */ NULL, 103 /* autoq */ 0, 104 105 /* open */ tapopen, 106 /* close */ tapclose, 107 /* read */ tapread, 108 /* write */ tapwrite, 109 /* ioctl */ tapioctl, 110 /* poll */ tappoll, 111 /* mmap */ nommap, 112 /* startegy */ nostrategy, 113 /* dump */ nodump, 114 /* psize */ nopsize 115 }; 116 117 static int taprefcnt = 0; /* module ref. counter */ 118 static int taplastunit = -1; /* max. open unit number */ 119 static int tapdebug = 0; /* debug flag */ 120 121 MALLOC_DECLARE(M_TAP); 122 MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface"); 123 SYSCTL_INT(_debug, OID_AUTO, if_tap_debug, CTLFLAG_RW, &tapdebug, 0, ""); 124 DEV_MODULE(if_tap, tapmodevent, NULL); 125 126 /* 127 * tapmodevent 128 * 129 * module event handler 130 */ 131 static int 132 tapmodevent(mod, type, data) 133 module_t mod; 134 int type; 135 void *data; 136 { 137 static int attached = 0; 138 struct ifnet *ifp = NULL; 139 int unit, s; 140 141 switch (type) { 142 case MOD_LOAD: 143 if (attached) 144 return (EEXIST); 145 146 cdevsw_add(&tap_cdevsw); 147 attached = 1; 148 break; 149 150 case MOD_UNLOAD: 151 if (taprefcnt > 0) 152 return (EBUSY); 153 154 cdevsw_remove(&tap_cdevsw); 155 156 unit = 0; 157 while (unit <= taplastunit) { 158 s = splimp(); 159 TAILQ_FOREACH(ifp, &ifnet, if_link) 160 if ((strcmp(ifp->if_name, TAP) == 0) || 161 (strcmp(ifp->if_name, VMNET) == 0)) 162 if (ifp->if_unit == unit) 163 break; 164 splx(s); 165 166 if (ifp != NULL) { 167 struct tap_softc *tp = ifp->if_softc; 168 169 TAPDEBUG("detaching %s%d. minor = %#x, " \ 170 "taplastunit = %d\n", 171 ifp->if_name, unit, minor(tp->tap_dev), 172 taplastunit); 173 174 s = splimp(); 175 ether_ifdetach(ifp, 1); 176 splx(s); 177 destroy_dev(tp->tap_dev); 178 free(tp, M_TAP); 179 } 180 else 181 unit ++; 182 } 183 184 attached = 0; 185 break; 186 187 default: 188 return (EOPNOTSUPP); 189 } 190 191 return (0); 192 } /* tapmodevent */ 193 194 195 /* 196 * tapcreate 197 * 198 * to create interface 199 */ 200 static void 201 tapcreate(dev) 202 dev_t dev; 203 { 204 struct ifnet *ifp = NULL; 205 struct tap_softc *tp = NULL; 206 unsigned short macaddr_hi; 207 int unit, s; 208 char *name = NULL; 209 210 /* allocate driver storage and create device */ 211 MALLOC(tp, struct tap_softc *, sizeof(*tp), M_TAP, M_WAITOK); 212 bzero(tp, sizeof(*tp)); 213 214 /* select device: tap or vmnet */ 215 if (minor(dev) & VMNET_DEV_MASK) { 216 name = VMNET; 217 unit = lminor(dev) & 0xff; 218 tp->tap_flags |= TAP_VMNET; 219 } 220 else { 221 name = TAP; 222 unit = lminor(dev); 223 } 224 225 tp->tap_dev = make_dev(&tap_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 226 0600, "%s%d", name, unit); 227 tp->tap_dev->si_drv1 = dev->si_drv1 = tp; 228 229 /* generate fake MAC address: 00 bd xx xx xx unit_no */ 230 macaddr_hi = htons(0x00bd); 231 bcopy(&macaddr_hi, &tp->arpcom.ac_enaddr[0], sizeof(short)); 232 bcopy(&ticks, &tp->arpcom.ac_enaddr[2], sizeof(long)); 233 tp->arpcom.ac_enaddr[5] = (u_char)unit; 234 235 /* fill the rest and attach interface */ 236 ifp = &tp->tap_if; 237 ifp->if_softc = tp; 238 239 ifp->if_unit = unit; 240 if (unit > taplastunit) 241 taplastunit = unit; 242 243 ifp->if_name = name; 244 ifp->if_init = tapifinit; 245 ifp->if_output = ether_output; 246 ifp->if_start = tapifstart; 247 ifp->if_ioctl = tapifioctl; 248 ifp->if_mtu = ETHERMTU; 249 ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST); 250 ifp->if_snd.ifq_maxlen = ifqmaxlen; 251 252 s = splimp(); 253 ether_ifattach(ifp, 1); 254 splx(s); 255 256 tp->tap_flags |= TAP_INITED; 257 258 TAPDEBUG("interface %s%d created. minor = %#x\n", 259 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 260 } /* tapcreate */ 261 262 263 /* 264 * tapopen 265 * 266 * to open tunnel. must be superuser 267 */ 268 static int 269 tapopen(dev_t dev, int flag, int mode, d_thread_t *td) 270 { 271 struct tap_softc *tp = NULL; 272 int error; 273 274 KKASSERT(p != NULL); 275 276 if ((error = suser(td)) != 0) 277 return (error); 278 279 tp = dev->si_drv1; 280 if (tp == NULL) { 281 tapcreate(dev); 282 tp = dev->si_drv1; 283 } 284 285 if (tp->tap_flags & TAP_OPEN) 286 return (EBUSY); 287 288 bcopy(tp->arpcom.ac_enaddr, tp->ether_addr, sizeof(tp->ether_addr)); 289 290 tp->tap_td = td; 291 tp->tap_flags |= TAP_OPEN; 292 taprefcnt ++; 293 294 TAPDEBUG("%s%d is open. minor = %#x, refcnt = %d, taplastunit = %d\n", 295 tp->tap_if.if_name, tp->tap_if.if_unit, 296 minor(tp->tap_dev), taprefcnt, taplastunit); 297 298 return (0); 299 } /* tapopen */ 300 301 302 /* 303 * tapclose 304 * 305 * close the device - mark i/f down & delete routing info 306 */ 307 static int 308 tapclose(dev_t dev, int foo, int bar, d_thread_t *td) 309 { 310 int s; 311 struct tap_softc *tp = dev->si_drv1; 312 struct ifnet *ifp = &tp->tap_if; 313 struct mbuf *m = NULL; 314 315 /* junk all pending output */ 316 317 s = splimp(); 318 do { 319 IF_DEQUEUE(&ifp->if_snd, m); 320 if (m != NULL) 321 m_freem(m); 322 } while (m != NULL); 323 splx(s); 324 325 /* 326 * do not bring the interface down, and do not anything with 327 * interface, if we are in VMnet mode. just close the device. 328 */ 329 330 if (((tp->tap_flags & TAP_VMNET) == 0) && (ifp->if_flags & IFF_UP)) { 331 s = splimp(); 332 if_down(ifp); 333 if (ifp->if_flags & IFF_RUNNING) { 334 /* find internet addresses and delete routes */ 335 struct ifaddr *ifa = NULL; 336 337 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 338 if (ifa->ifa_addr->sa_family == AF_INET) { 339 rtinit(ifa, (int)RTM_DELETE, 0); 340 341 /* remove address from interface */ 342 bzero(ifa->ifa_addr, 343 sizeof(*(ifa->ifa_addr))); 344 bzero(ifa->ifa_dstaddr, 345 sizeof(*(ifa->ifa_dstaddr))); 346 bzero(ifa->ifa_netmask, 347 sizeof(*(ifa->ifa_netmask))); 348 } 349 } 350 351 ifp->if_flags &= ~IFF_RUNNING; 352 } 353 splx(s); 354 } 355 356 funsetown(tp->tap_sigio); 357 selwakeup(&tp->tap_rsel); 358 359 tp->tap_flags &= ~TAP_OPEN; 360 tp->tap_td = NULL; 361 362 taprefcnt --; 363 if (taprefcnt < 0) { 364 taprefcnt = 0; 365 printf("%s%d minor = %#x, refcnt = %d is out of sync. " \ 366 "set refcnt to 0\n", ifp->if_name, ifp->if_unit, 367 minor(tp->tap_dev), taprefcnt); 368 } 369 370 TAPDEBUG("%s%d is closed. minor = %#x, refcnt = %d, taplastunit = %d\n", 371 ifp->if_name, ifp->if_unit, minor(tp->tap_dev), 372 taprefcnt, taplastunit); 373 374 return (0); 375 } /* tapclose */ 376 377 378 /* 379 * tapifinit 380 * 381 * network interface initialization function 382 */ 383 static void 384 tapifinit(xtp) 385 void *xtp; 386 { 387 struct tap_softc *tp = (struct tap_softc *)xtp; 388 struct ifnet *ifp = &tp->tap_if; 389 390 TAPDEBUG("initializing %s%d, minor = %#x\n", 391 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 392 393 ifp->if_flags |= IFF_RUNNING; 394 ifp->if_flags &= ~IFF_OACTIVE; 395 396 /* attempt to start output */ 397 tapifstart(ifp); 398 } /* tapifinit */ 399 400 401 /* 402 * tapifioctl 403 * 404 * Process an ioctl request on network interface 405 */ 406 int 407 tapifioctl(ifp, cmd, data) 408 struct ifnet *ifp; 409 u_long cmd; 410 caddr_t data; 411 { 412 struct tap_softc *tp = (struct tap_softc *)(ifp->if_softc); 413 struct ifstat *ifs = NULL; 414 int s, dummy; 415 416 switch (cmd) { 417 case SIOCSIFADDR: 418 case SIOCGIFADDR: 419 case SIOCSIFMTU: 420 s = splimp(); 421 dummy = ether_ioctl(ifp, cmd, data); 422 splx(s); 423 return (dummy); 424 425 case SIOCSIFFLAGS: /* XXX -- just like vmnet does */ 426 case SIOCADDMULTI: 427 case SIOCDELMULTI: 428 break; 429 430 case SIOCGIFSTATUS: 431 s = splimp(); 432 ifs = (struct ifstat *)data; 433 dummy = strlen(ifs->ascii); 434 if (tp->tap_td != NULL && dummy < sizeof(ifs->ascii)) { 435 if (tp->tap_td->td_proc) { 436 snprintf(ifs->ascii + dummy, 437 sizeof(ifs->ascii) - dummy, 438 "\tOpened by pid %d\n", 439 (int)tp->tap_td->td_proc->p_pid); 440 } else { 441 snprintf(ifs->ascii + dummy, 442 sizeof(ifs->ascii) - dummy, 443 "\tOpened by td %p\n", tp->tap_td); 444 } 445 } 446 splx(s); 447 break; 448 449 default: 450 return (EINVAL); 451 } 452 453 return (0); 454 } /* tapifioctl */ 455 456 457 /* 458 * tapifstart 459 * 460 * queue packets from higher level ready to put out 461 */ 462 static void 463 tapifstart(ifp) 464 struct ifnet *ifp; 465 { 466 struct tap_softc *tp = ifp->if_softc; 467 int s; 468 469 TAPDEBUG("%s%d starting, minor = %#x\n", 470 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 471 472 /* 473 * do not junk pending output if we are in VMnet mode. 474 * XXX: can this do any harm because of queue overflow? 475 */ 476 477 if (((tp->tap_flags & TAP_VMNET) == 0) && 478 ((tp->tap_flags & TAP_READY) != TAP_READY)) { 479 struct mbuf *m = NULL; 480 481 TAPDEBUG("%s%d not ready. minor = %#x, tap_flags = 0x%x\n", 482 ifp->if_name, ifp->if_unit, 483 minor(tp->tap_dev), tp->tap_flags); 484 485 s = splimp(); 486 do { 487 IF_DEQUEUE(&ifp->if_snd, m); 488 if (m != NULL) 489 m_freem(m); 490 ifp->if_oerrors ++; 491 } while (m != NULL); 492 splx(s); 493 494 return; 495 } 496 497 s = splimp(); 498 ifp->if_flags |= IFF_OACTIVE; 499 500 if (ifp->if_snd.ifq_len != 0) { 501 if (tp->tap_flags & TAP_RWAIT) { 502 tp->tap_flags &= ~TAP_RWAIT; 503 wakeup((caddr_t)tp); 504 } 505 506 if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL)) 507 pgsigio(tp->tap_sigio, SIGIO, 0); 508 509 selwakeup(&tp->tap_rsel); 510 ifp->if_opackets ++; /* obytes are counted in ether_output */ 511 } 512 513 ifp->if_flags &= ~IFF_OACTIVE; 514 splx(s); 515 } /* tapifstart */ 516 517 518 /* 519 * tapioctl 520 * 521 * the cdevsw interface is now pretty minimal 522 */ 523 static int 524 tapioctl(dev_t dev, u_long cmd, caddr_t data, int flag, d_thread_t *td) 525 { 526 struct tap_softc *tp = dev->si_drv1; 527 struct ifnet *ifp = &tp->tap_if; 528 struct tapinfo *tapp = NULL; 529 int s; 530 531 switch (cmd) { 532 case TAPSIFINFO: 533 s = splimp(); 534 tapp = (struct tapinfo *)data; 535 ifp->if_mtu = tapp->mtu; 536 ifp->if_type = tapp->type; 537 ifp->if_baudrate = tapp->baudrate; 538 splx(s); 539 break; 540 541 case TAPGIFINFO: 542 tapp = (struct tapinfo *)data; 543 tapp->mtu = ifp->if_mtu; 544 tapp->type = ifp->if_type; 545 tapp->baudrate = ifp->if_baudrate; 546 break; 547 548 case TAPSDEBUG: 549 tapdebug = *(int *)data; 550 break; 551 552 case TAPGDEBUG: 553 *(int *)data = tapdebug; 554 break; 555 556 case FIONBIO: 557 break; 558 559 case FIOASYNC: 560 s = splimp(); 561 if (*(int *)data) 562 tp->tap_flags |= TAP_ASYNC; 563 else 564 tp->tap_flags &= ~TAP_ASYNC; 565 splx(s); 566 break; 567 568 case FIONREAD: 569 s = splimp(); 570 if (ifp->if_snd.ifq_head) { 571 struct mbuf *mb = ifp->if_snd.ifq_head; 572 573 for(*(int *)data = 0;mb != NULL;mb = mb->m_next) 574 *(int *)data += mb->m_len; 575 } 576 else 577 *(int *)data = 0; 578 splx(s); 579 break; 580 581 case FIOSETOWN: 582 return (fsetown(*(int *)data, &tp->tap_sigio)); 583 584 case FIOGETOWN: 585 *(int *)data = fgetown(tp->tap_sigio); 586 return (0); 587 588 /* this is deprecated, FIOSETOWN should be used instead */ 589 case TIOCSPGRP: 590 return (fsetown(-(*(int *)data), &tp->tap_sigio)); 591 592 /* this is deprecated, FIOGETOWN should be used instead */ 593 case TIOCGPGRP: 594 *(int *)data = -fgetown(tp->tap_sigio); 595 return (0); 596 597 /* VMware/VMnet port ioctl's */ 598 599 case SIOCGIFFLAGS: /* get ifnet flags */ 600 bcopy(&ifp->if_flags, data, sizeof(ifp->if_flags)); 601 break; 602 603 case VMIO_SIOCSIFFLAGS: { /* VMware/VMnet SIOCSIFFLAGS */ 604 short f = *(short *)data; 605 606 f &= 0x0fff; 607 f &= ~IFF_CANTCHANGE; 608 f |= IFF_UP; 609 610 s = splimp(); 611 ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE); 612 splx(s); 613 } break; 614 615 case OSIOCGIFADDR: /* get MAC address of the remote side */ 616 case SIOCGIFADDR: 617 bcopy(tp->ether_addr, data, sizeof(tp->ether_addr)); 618 break; 619 620 case SIOCSIFADDR: /* set MAC address of the remote side */ 621 bcopy(data, tp->ether_addr, sizeof(tp->ether_addr)); 622 break; 623 624 default: 625 return (ENOTTY); 626 } 627 return (0); 628 } /* tapioctl */ 629 630 631 /* 632 * tapread 633 * 634 * the cdevsw read interface - reads a packet at a time, or at 635 * least as much of a packet as can be read 636 */ 637 static int 638 tapread(dev, uio, flag) 639 dev_t dev; 640 struct uio *uio; 641 int flag; 642 { 643 struct tap_softc *tp = dev->si_drv1; 644 struct ifnet *ifp = &tp->tap_if; 645 struct mbuf *m0 = NULL; 646 int error = 0, len, s; 647 648 TAPDEBUG("%s%d reading, minor = %#x\n", 649 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 650 651 if ((tp->tap_flags & TAP_READY) != TAP_READY) { 652 TAPDEBUG("%s%d not ready. minor = %#x, tap_flags = 0x%x\n", 653 ifp->if_name, ifp->if_unit, 654 minor(tp->tap_dev), tp->tap_flags); 655 656 return (EHOSTDOWN); 657 } 658 659 tp->tap_flags &= ~TAP_RWAIT; 660 661 /* sleep until we get a packet */ 662 do { 663 s = splimp(); 664 IF_DEQUEUE(&ifp->if_snd, m0); 665 splx(s); 666 667 if (m0 == NULL) { 668 if (flag & IO_NDELAY) 669 return (EWOULDBLOCK); 670 671 tp->tap_flags |= TAP_RWAIT; 672 error = tsleep((caddr_t)tp, PCATCH, "taprd", 0); 673 if (error) 674 return (error); 675 } 676 } while (m0 == NULL); 677 678 /* feed packet to bpf */ 679 if (ifp->if_bpf != NULL) 680 bpf_mtap(ifp, m0); 681 682 /* xfer packet to user space */ 683 while ((m0 != NULL) && (uio->uio_resid > 0) && (error == 0)) { 684 len = min(uio->uio_resid, m0->m_len); 685 if (len == 0) 686 break; 687 688 error = uiomove(mtod(m0, caddr_t), len, uio); 689 m0 = m_free(m0); 690 } 691 692 if (m0 != NULL) { 693 TAPDEBUG("%s%d dropping mbuf, minor = %#x\n", 694 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 695 m_freem(m0); 696 } 697 698 return (error); 699 } /* tapread */ 700 701 702 /* 703 * tapwrite 704 * 705 * the cdevsw write interface - an atomic write is a packet - or else! 706 */ 707 static int 708 tapwrite(dev, uio, flag) 709 dev_t dev; 710 struct uio *uio; 711 int flag; 712 { 713 struct tap_softc *tp = dev->si_drv1; 714 struct ifnet *ifp = &tp->tap_if; 715 struct mbuf *top = NULL, **mp = NULL, *m = NULL; 716 struct ether_header *eh = NULL; 717 int error = 0, tlen, mlen; 718 719 TAPDEBUG("%s%d writting, minor = %#x\n", 720 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 721 722 if (uio->uio_resid == 0) 723 return (0); 724 725 if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) { 726 TAPDEBUG("%s%d invalid packet len = %d, minor = %#x\n", 727 ifp->if_name, ifp->if_unit, 728 uio->uio_resid, minor(tp->tap_dev)); 729 730 return (EIO); 731 } 732 tlen = uio->uio_resid; 733 734 /* get a header mbuf */ 735 MGETHDR(m, M_DONTWAIT, MT_DATA); 736 if (m == NULL) 737 return (ENOBUFS); 738 mlen = MHLEN; 739 740 top = 0; 741 mp = ⊤ 742 while ((error == 0) && (uio->uio_resid > 0)) { 743 m->m_len = min(mlen, uio->uio_resid); 744 error = uiomove(mtod(m, caddr_t), m->m_len, uio); 745 *mp = m; 746 mp = &m->m_next; 747 if (uio->uio_resid > 0) { 748 MGET(m, M_DONTWAIT, MT_DATA); 749 if (m == NULL) { 750 error = ENOBUFS; 751 break; 752 } 753 mlen = MLEN; 754 } 755 } 756 if (error) { 757 ifp->if_ierrors ++; 758 if (top) 759 m_freem(top); 760 return (error); 761 } 762 763 top->m_pkthdr.len = tlen; 764 top->m_pkthdr.rcvif = ifp; 765 766 /* 767 * Ethernet bridge and bpf are handled in ether_input 768 * 769 * adjust mbuf and give packet to the ether_input 770 */ 771 772 eh = mtod(top, struct ether_header *); 773 m_adj(top, sizeof(struct ether_header)); 774 ether_input(ifp, eh, top); 775 ifp->if_ipackets ++; /* ibytes are counted in ether_input */ 776 777 return (0); 778 } /* tapwrite */ 779 780 781 /* 782 * tappoll 783 * 784 * the poll interface, this is only useful on reads 785 * really. the write detect always returns true, write never blocks 786 * anyway, it either accepts the packet or drops it 787 */ 788 static int 789 tappoll(dev_t dev, int events, d_thread_t *td) 790 { 791 struct tap_softc *tp = dev->si_drv1; 792 struct ifnet *ifp = &tp->tap_if; 793 int s, revents = 0; 794 795 TAPDEBUG("%s%d polling, minor = %#x\n", 796 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 797 798 s = splimp(); 799 if (events & (POLLIN | POLLRDNORM)) { 800 if (ifp->if_snd.ifq_len > 0) { 801 TAPDEBUG("%s%d have data in queue. len = %d, " \ 802 "minor = %#x\n", ifp->if_name, ifp->if_unit, 803 ifp->if_snd.ifq_len, minor(tp->tap_dev)); 804 805 revents |= (events & (POLLIN | POLLRDNORM)); 806 } 807 else { 808 TAPDEBUG("%s%d waiting for data, minor = %#x\n", 809 ifp->if_name, ifp->if_unit, minor(tp->tap_dev)); 810 811 selrecord(td, &tp->tap_rsel); 812 } 813 } 814 815 if (events & (POLLOUT | POLLWRNORM)) 816 revents |= (events & (POLLOUT | POLLWRNORM)); 817 818 splx(s); 819 return (revents); 820 } /* tappoll */ 821