summaryrefslogtreecommitdiffstats
path: root/test/test_ip4.py
AgeCommit message (Expand)AuthorFilesLines
2017-09-11FIB table add/delete APINeale Ranns1-3/+8
2017-08-01Tests for recursive load-balancing with no choices.Neale Ranns1-5/+35
2017-06-06Packets recieved on VLAN-0 map to the main interfaceNeale Ranns1-0/+46
2017-05-25MPLS hash function improvementsNeale Ranns1-18/+43
2017-04-26IP Flow Hash Config fixesNeale Ranns1-0/+137
2017-03-29Sub-net broadcast addresses for IPv4Neale Ranns1-1/+124
2017-03-17Fix IP feature ordering.Neale Ranns1-1/+98
2017-03-09Tests to target holes in adjacency and DPO test coverageNeale Ranns1-1/+82
2017-01-11make test: improve documentation and PEP8 complianceKlement Sekera1-7/+10
2016-12-23make test: improve handling of packet capturesKlement Sekera1-11/+8
2016-12-09make test: FIB add/update/delete - ip4 routesMatej Klotton1-2/+266
2016-12-05make test: fix missing log/packet messagesKlement Sekera1-7/+5
2016-11-15Update test documentation.Matej Klotton1-18/+60
2016-11-09Disable non-working checks in load-balancer test and rename ip->ip4Klement Sekera1-0/+165
293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
/* 
 *------------------------------------------------------------------
 * tuntap.c - kernel stack (reverse) punt/inject path
 *
 * Copyright (c) 2009 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *------------------------------------------------------------------
 */
/**
 * @file
 * @brief  TunTap Kernel stack (reverse) punt/inject path.
 *
 * This driver runs in one of two distinct modes:
 * - "punt/inject" mode, where we send pkts not otherwise processed
 * by the forwarding to the Linux kernel stack, and
 *
 * - "normal interface" mode, where we treat the Linux kernel stack
 * as a peer.
 *
 * By default, we select punt/inject mode.
 */

#include <fcntl.h>		/* for open */
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/uio.h>		/* for iovec */
#include <netinet/in.h>

#include <linux/if_arp.h>
#include <linux/if_tun.h>

#include <vlib/vlib.h>
#include <vlib/unix/unix.h>

#include <vnet/ip/ip.h>
#include <vnet/fib/fib_table.h>

#include <vnet/ethernet/ethernet.h>
#include <vnet/devices/devices.h>
#include <vnet/feature/feature.h>

static vnet_device_class_t tuntap_dev_class;
static vnet_hw_interface_class_t tuntap_interface_class;

static void tuntap_punt_frame (vlib_main_t * vm,
                               vlib_node_runtime_t * node,
                               vlib_frame_t * frame);
static void tuntap_nopunt_frame (vlib_main_t * vm,
                                 vlib_node_runtime_t * node,
                                 vlib_frame_t * frame);

typedef struct {
  u32 sw_if_index;
  u8 is_v6;
  u8 addr[16];
} subif_address_t;

/**
 * @brief TUNTAP node main state
 */
typedef struct {
  /** Vector of iovecs for readv calls. */
  struct iovec * rd_iovecs;

  /** Vector of iovecs for writev calls. */
  struct iovec * wr_iovecs;

  /** Vector of VLIB rx buffers to use.  We allocate them in blocks
     of VLIB_FRAME_SIZE (256). */
  u32 * rx_buffers;

  /** File descriptors for /dev/net/tun and provisioning socket. */
  int dev_net_tun_fd, dev_tap_fd;

  /** Create a "tap" [ethernet] encaps device */
  int is_ether;

  /** 1 if a "normal" routed intfc, 0 if a punt/inject interface */

  int have_normal_interface;

  /** tap device destination MAC address. Required, or Linux drops pkts */
  u8 ether_dst_mac[6];

  /** Interface MTU in bytes and # of default sized buffers. */
  u32 mtu_bytes, mtu_buffers;

  /** Linux interface name for tun device. */
  char * tun_name;

  /** Pool of subinterface addresses */
  subif_address_t *subifs;

  /** Hash for subif addresses */
  mhash_t subif_mhash;

  /** Unix file index */
  u32 clib_file_index;

  /** For the "normal" interface, if configured */
  u32 hw_if_index, sw_if_index;

} tuntap_main_t;

static tuntap_main_t tuntap_main = {
  .tun_name = "vnet",

  /** Suitable defaults for an Ethernet-like tun/tap device */
  .mtu_bytes = 4096 + 256,
};

/**
 * @brief tuntap_tx
 * @node tuntap-tx
 *
 * Output node, writes the buffers comprising the incoming frame
 * to the tun/tap device, aka hands them to the Linux kernel stack.
 *
 * @param *vm - vlib_main_t
 * @param *node - vlib_node_runtime_t
 * @param *frame - vlib_frame_t
 *
 * @return rc - uword
 *
 */
static uword
tuntap_tx (vlib_main_t * vm,
	   vlib_node_runtime_t * node,
	   vlib_frame_t * frame)
{
  u32 * buffers = vlib_frame_args (frame);
  uword n_packets = frame->n_vectors;
  tuntap_main_t * tm = &tuntap_main;
  vnet_main_t *vnm = vnet_get_main ();
  vnet_interface_main_t *im = &vnm->interface_main;
  u32 n_bytes = 0;
  int i;

  for (i = 0; i < n_packets; i++)
    {
      struct iovec * iov;
      vlib_buffer_t * b;
      uword l;

      b = vlib_get_buffer (vm, buffers[i]);

      if (tm->is_ether && (!tm->have_normal_interface))
        {
          vlib_buffer_reset(b);
          clib_memcpy (vlib_buffer_get_current (b), tm->ether_dst_mac, 6);
        }

      /* Re-set iovecs if present. */
      if (tm->wr_iovecs)
	_vec_len (tm->wr_iovecs) = 0;

      /** VLIB buffer chain -> Unix iovec(s). */
      vec_add2 (tm->wr_iovecs, iov, 1);
      iov->iov_base = b->data + b->current_data;
      iov->iov_len = l = b->current_length;

      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
	{
	  do {
	    b = vlib_get_buffer (vm, b->next_buffer);

	    vec_add2 (tm->wr_iovecs, iov, 1);

	    iov->iov_base = b->data + b->current_data;
	    iov->iov_len = b->current_length;
	    l += b->current_length;
	  } while (b->flags & VLIB_BUFFER_NEXT_PRESENT);
	}

      if (writev (tm->dev_net_tun_fd, tm->wr_iovecs,
		  vec_len (tm->wr_iovecs)) < l)
	clib_unix_warning ("writev");

      n_bytes += l;
    }

  /* Update tuntap interface output stats. */
  vlib_increment_combined_counter (im->combined_sw_if_counters
				   + VNET_INTERFACE_COUNTER_TX,
				   vm->thread_index,
				   tm->sw_if_index, n_packets, n_bytes);


  /** The normal interface path flattens the buffer chain */
  if (tm->have_normal_interface)
    vlib_buffer_free_no_next (vm, buffers, n_packets);
  else
    vlib_buffer_free (vm, buffers, n_packets);

  return n_packets;
}

VLIB_REGISTER_NODE (tuntap_tx_node,static) = {
  .function = tuntap_tx,
  .name = "tuntap-tx",
  .type = VLIB_NODE_TYPE_INTERNAL,
  .vector_size = 4,
};

/**
 * @brief TUNTAP receive node
 * @node tuntap-rx
 *
 * @param *vm - vlib_main_t
 * @param *node - vlib_node_runtime_t
 * @param *frame - vlib_frame_t
 *
 * @return rc - uword
 *
 */
static uword
tuntap_rx (vlib_main_t * vm,
	   vlib_node_runtime_t * node,
	   vlib_frame_t * frame)
{
  tuntap_main_t * tm = &tuntap_main;
  vlib_buffer_t * b;
  u32 bi;
  const uword buffer_size = VLIB_BUFFER_DATA_SIZE;

  /** Make sure we have some RX buffers. */
  {
    uword n_left = vec_len (tm->rx_buffers);
    uword n_alloc;

    if (n_left < VLIB_FRAME_SIZE / 2)
      {
	if (! tm->rx_buffers)
	  vec_alloc (tm->rx_buffers, VLIB_FRAME_SIZE);

	n_alloc = vlib_buffer_alloc (vm, tm->rx_buffers + n_left, VLIB_FRAME_SIZE - n_left);
	_vec_len (tm->rx_buffers) = n_left + n_alloc;
      }
  }

  /** Allocate RX buffers from end of rx_buffers.
     Turn them into iovecs to pass to readv. */
  {
    uword i_rx = vec_len (tm->rx_buffers) - 1;
    vlib_buffer_t * b;
    word i, n_bytes_left, n_bytes_in_packet;

    /** We should have enough buffers left for an MTU sized packet. */
    ASSERT (vec_len (tm->rx_buffers) >= tm->mtu_buffers);

    vec_validate (tm->rd_iovecs, tm->mtu_buffers - 1);
    for (i = 0; i < tm->mtu_buffers; i++)
      {
	b = vlib_get_buffer (vm, tm->rx_buffers[i_rx - i]);
	tm->rd_iovecs[i].iov_base = b->data;
	tm->rd_iovecs[i].iov_len = buffer_size;
      }

    n_bytes_left = readv (tm->dev_net_tun_fd, tm->rd_iovecs, tm->mtu_buffers);
    n_bytes_in_packet = n_bytes_left;
    if (n_bytes_left <= 0)
      {
        if (errno != EAGAIN)
          clib_unix_warning ("readv %d", n_bytes_left);
	return 0;
      }

    bi = tm->rx_buffers[i_rx];

    while (1)
      {
	b = vlib_get_buffer (vm, tm->rx_buffers[i_rx]);
	b->flags = 0;
	b->current_data = 0;
	b->current_length = n_bytes_left < buffer_size ? n_bytes_left : buffer_size;

	n_bytes_left -= buffer_size;

	if (n_bytes_left <= 0)
          {
            break;
          }

	i_rx--;
	b->flags |= VLIB_BUFFER_NEXT_PRESENT;
	b->next_buffer = tm->rx_buffers[i_rx];
      }

    /** Interface counters for tuntap interface. */
    vlib_increment_combined_counter
        (vnet_main.interface_main.combined_sw_if_counters
         + VNET_INTERFACE_COUNTER_RX,
         vlib_get_thread_index(),
         tm->sw_if_index,
         1, n_bytes_in_packet);

    _vec_len (tm->rx_buffers) = i_rx;
  }

  b = vlib_get_buffer (vm, bi);

  {
    u32 next_index;
    uword n_trace = vlib_get_trace_count (vm, node);

    vnet_buffer (b)->sw_if_index[VLIB_RX] = tm->sw_if_index;
    vnet_buffer (b)->sw_if_index[VLIB_TX] = (u32)~0;

    /*
     * Turn this on if you run into
     * "bad monkey" contexts, and you want to know exactly
     * which nodes they've visited...
     */
    if (VLIB_BUFFER_TRACE_TRAJECTORY)
        b->pre_data[0] = 0;

    b->error = node->errors[0];

    if (tm->is_ether)
      {
	next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
      }
    else
      switch (b->data[0] & 0xf0)
        {
        case 0x40:
          next_index = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
          break;
        case 0x60:
          next_index = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
          break;
        default:
          next_index = VNET_DEVICE_INPUT_NEXT_DROP;
          break;
        }

    /* The linux kernel couldn't care less if our interface is up */
    if (tm->have_normal_interface)
      {
        vnet_main_t *vnm = vnet_get_main();
        vnet_sw_interface_t * si;
        si = vnet_get_sw_interface (vnm, tm->sw_if_index);
        if (!(si->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP))
          next_index = VNET_DEVICE_INPUT_NEXT_DROP;
      }

    vnet_feature_start_device_input_x1 (tm->sw_if_index, &next_index, b);

    vlib_set_next_frame_buffer (vm, node, next_index, bi);

    if (n_trace > 0)
      {
        vlib_trace_buffer (vm, node, next_index,
                           b, /* follow_chain */ 1);
        vlib_set_trace_count (vm, node, n_trace - 1);
      }
  }

  return 1;
}

/**
 * @brief TUNTAP_RX error strings
 */
static char * tuntap_rx_error_strings[] = {
  "unknown packet type",
};

VLIB_REGISTER_NODE (tuntap_rx_node,static) = {
  .function = tuntap_rx,
  .name = "tuntap-rx",
  .sibling_of = "device-input",
  .type = VLIB_NODE_TYPE_INPUT,
  .state = VLIB_NODE_STATE_INTERRUPT,
  .vector_size = 4,
  .n_errors = 1,
  .error_strings = tuntap_rx_error_strings,
};

/**
 * @brief Gets called when file descriptor is ready from epoll.
 *
 * @param *uf - clib_file_t
 *
 * @return error - clib_error_t
 */
static clib_error_t * tuntap_read_ready (clib_file_t * uf)
{
  vlib_main_t * vm = vlib_get_main();
  vlib_node_set_interrupt_pending (vm, tuntap_rx_node.index);
  return 0;
}

/**
 * @brief Clean up the tun/tap device
 *
 * @param *vm - vlib_main_t
 *
 * @return error - clib_error_t
 *
 */
static clib_error_t *
tuntap_exit (vlib_main_t * vm)
{
  tuntap_main_t *tm = &tuntap_main;
  struct ifreq ifr;
  int sfd;

  /* Not present. */
  if (! tm->dev_net_tun_fd || tm->dev_net_tun_fd < 0)
    return 0;

  sfd = socket (AF_INET, SOCK_STREAM, 0);
  if (sfd < 0)
    clib_unix_warning("provisioning socket");

  memset(&ifr, 0, sizeof (ifr));
  strncpy (ifr.ifr_name, tm->tun_name, sizeof (ifr.ifr_name)-1);

  /* get flags, modify to bring down interface... */
  if (ioctl (sfd, SIOCGIFFLAGS, &ifr) < 0)
    clib_unix_warning ("SIOCGIFFLAGS");

  ifr.ifr_flags &= ~(IFF_UP | IFF_RUNNING);

  if (ioctl (sfd, SIOCSIFFLAGS, &ifr) < 0)
    clib_unix_warning ("SIOCSIFFLAGS");

  /* Turn off persistence */
  if (ioctl (tm->dev_net_tun_fd, TUNSETPERSIST, 0) < 0)
    clib_unix_warning ("TUNSETPERSIST");
  close(tm->dev_tap_fd);
  if (tm->dev_net_tun_fd >= 0)
    close(tm->dev_net_tun_fd);
  if (sfd >= 0)
    close (sfd);

  return 0;
}

VLIB_MAIN_LOOP_EXIT_FUNCTION (tuntap_exit);

/**
 * @brief CLI function for tun/tap config
 *
 * @param *vm - vlib_main_t
 * @param *input - unformat_input_t
 *
 * @return error - clib_error_t
 *
 */
static clib_error_t *
tuntap_config (vlib_main_t * vm, unformat_input_t * input)
{
  tuntap_main_t *tm = &tuntap_main;
  clib_error_t * error = 0;
  struct ifreq ifr;
  u8 * name;
  int flags = IFF_TUN | IFF_NO_PI;
  int is_enabled = 0, is_ether = 0, have_normal_interface = 0;
  const uword buffer_size = VLIB_BUFFER_DATA_SIZE;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "mtu %d", &tm->mtu_bytes))
	;
      else if (unformat (input, "enable"))
        is_enabled = 1;
      else if (unformat (input, "disable"))
        is_enabled = 0;
      else if (unformat (input, "ethernet") ||
               unformat (input, "ether"))
        is_ether = 1;
      else if (unformat (input, "have-normal-interface") ||
               unformat (input, "have-normal"))
        have_normal_interface = 1;
      else if (unformat (input, "name %s", &name))
	tm->tun_name = (char *) name;
      else
	return clib_error_return (0, "unknown input `%U'",
				  format_unformat_error, input);
    }

  tm->dev_net_tun_fd = -1;
  tm->dev_tap_fd = -1;

  if (is_enabled == 0)
    return 0;

  if (geteuid()) 
    {
      clib_warning ("tuntap disabled: must be superuser");
      return 0;
    }    

  tm->is_ether = is_ether;
  tm->have_normal_interface = have_normal_interface;

  if (is_ether)
    flags = IFF_TAP | IFF_NO_PI;

  if ((tm->dev_net_tun_fd = open ("/dev/net/tun", O_RDWR)) < 0)
    {
      error = clib_error_return_unix (0, "open /dev/net/tun");
      goto done;
    }

  memset (&ifr, 0, sizeof (ifr));
  strncpy(ifr.ifr_name, tm->tun_name, sizeof(ifr.ifr_name)-1);
  ifr.ifr_flags = flags;
  if (ioctl (tm->dev_net_tun_fd, TUNSETIFF, (void *)&ifr) < 0)
    {
      error = clib_error_return_unix (0, "ioctl TUNSETIFF");
      goto done;
    }
    
  /* Make it persistent, at least until we split. */
  if (ioctl (tm->dev_net_tun_fd, TUNSETPERSIST, 1) < 0)
    {
      error = clib_error_return_unix (0, "TUNSETPERSIST");
      goto done;
    }

  /* Open a provisioning socket */
  if ((tm->dev_tap_fd = socket(PF_PACKET, SOCK_RAW,
			       htons(ETH_P_ALL))) < 0 )
    {
      error = clib_error_return_unix (0, "socket");
      goto done;
    }

  /* Find the interface index. */
  {
    struct ifreq ifr;
    struct sockaddr_ll sll;

    memset (&ifr, 0, sizeof(ifr));
    strncpy (ifr.ifr_name, tm->tun_name, sizeof(ifr.ifr_name)-1);
    if (ioctl (tm->dev_tap_fd, SIOCGIFINDEX, &ifr) < 0 )
      {
	error = clib_error_return_unix (0, "ioctl SIOCGIFINDEX");
	goto done;
      }

    /* Bind the provisioning socket to the interface. */
    memset(&sll, 0, sizeof(sll));
    sll.sll_family   = AF_PACKET;
    sll.sll_ifindex  = ifr.ifr_ifindex;
    sll.sll_protocol = htons(ETH_P_ALL);

    if (bind(tm->dev_tap_fd, (struct sockaddr*) &sll, sizeof(sll)) < 0)
      {
	error = clib_error_return_unix (0, "bind");
	goto done;
      }
  }

  /* non-blocking I/O on /dev/tapX */
  {
    int one = 1;
    if (ioctl (tm->dev_net_tun_fd, FIONBIO, &one) < 0)
      {
	error = clib_error_return_unix (0, "ioctl FIONBIO");
	goto done;
      }
  }

  tm->mtu_buffers = (tm->mtu_bytes + (buffer_size - 1)) / buffer_size;

  ifr.ifr_mtu = tm->mtu_bytes;
  if (ioctl (tm->dev_tap_fd, SIOCSIFMTU, &ifr) < 0)
    {
      error = clib_error_return_unix (0, "ioctl SIOCSIFMTU");
      goto done;
    }

  /* get flags, modify to bring up interface... */
  if (ioctl (tm->dev_tap_fd, SIOCGIFFLAGS, &ifr) < 0)
    {
      error = clib_error_return_unix (0, "ioctl SIOCGIFFLAGS");
      goto done;
    }

  ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);

  if (ioctl (tm->dev_tap_fd, SIOCSIFFLAGS, &ifr) < 0)
    {
      error = clib_error_return_unix (0, "ioctl SIOCSIFFLAGS");
      goto done;
    }

  if (is_ether)
    {
      if (ioctl (tm->dev_tap_fd, SIOCGIFHWADDR, &ifr) < 0)
        {
          error = clib_error_return_unix (0, "ioctl SIOCGIFHWADDR");
          goto done;
        }
      else
        clib_memcpy (tm->ether_dst_mac, ifr.ifr_hwaddr.sa_data, 6);
    }

  if (have_normal_interface)
    {
      vnet_main_t *vnm = vnet_get_main();
      error = ethernet_register_interface
        (vnm,
         tuntap_dev_class.index,
         0 /* device instance */,
         tm->ether_dst_mac /* ethernet address */,
         &tm->hw_if_index, 
         0 /* flag change */);
      if (error)
        clib_error_report (error);
      tm->sw_if_index = tm->hw_if_index;
      vm->os_punt_frame = tuntap_nopunt_frame;
    }
  else
    {
      vnet_main_t *vnm = vnet_get_main();
      vnet_hw_interface_t * hi;
      
      vm->os_punt_frame = tuntap_punt_frame;
      
      tm->hw_if_index = vnet_register_interface
        (vnm,
         tuntap_dev_class.index, 0 /* device instance */,
         tuntap_interface_class.index, 0);
      hi = vnet_get_hw_interface (vnm, tm->hw_if_index);
      tm->sw_if_index = hi->sw_if_index;
      
      /* Interface is always up. */
      vnet_hw_interface_set_flags (vnm, tm->hw_if_index, 
                                   VNET_HW_INTERFACE_FLAG_LINK_UP);
      vnet_sw_interface_set_flags (vnm, tm->sw_if_index, 
                                   VNET_SW_INTERFACE_FLAG_ADMIN_UP);
    }

  {
    clib_file_t template = {0};
    template.read_function = tuntap_read_ready;
    template.file_descriptor = tm->dev_net_tun_fd;
    tm->clib_file_index = clib_file_add (&file_main, &template);
  }

 done:
  if (error)
    {
      if (tm->dev_net_tun_fd >= 0)
	close (tm->dev_net_tun_fd);
      if (tm->dev_tap_fd >= 0)
	close (tm->dev_tap_fd);
    }

  return error;
}

VLIB_CONFIG_FUNCTION (tuntap_config, "tuntap");

/**
 * @brief Add or Del IP4 address to tun/tap interface
 *
 * @param *im - ip4_main_t
 * @param opaque - uword
 * @param sw_if_index - u32
 * @param *address - ip4_address_t
 * @param is_delete - u32
 *
 */
void
tuntap_ip4_add_del_interface_address (ip4_main_t * im,
				      uword opaque,
				      u32 sw_if_index,
				      ip4_address_t * address,
				      u32 address_length,
				      u32 if_address_index,
				      u32 is_delete)
{
  tuntap_main_t * tm = &tuntap_main;
  struct ifreq ifr;
  subif_address_t subif_addr, * ap;
  uword * p;

  /** Tuntap disabled, or using a "normal" interface. */
  if (tm->have_normal_interface ||  tm->dev_tap_fd < 0)
    return;

  /* if the address is being applied to an interface that is not in
   * the same table/VRF as this tap, then ignore it.
   * If we don't do this overlapping address spaces in the diferent tables
   * breaks the linux host's routing tables */
  if (fib_table_get_index_for_sw_if_index(FIB_PROTOCOL_IP4,
                                          sw_if_index) !=
      fib_table_get_index_for_sw_if_index(FIB_PROTOCOL_IP4,
                                          tm->sw_if_index))
      return;

  /** See if we already know about this subif */
  memset (&subif_addr, 0, sizeof (subif_addr));
  subif_addr.sw_if_index = sw_if_index;
  clib_memcpy (&subif_addr.addr, address, sizeof (*address));

  p = mhash_get (&tm->subif_mhash, &subif_addr);

  if (p)
    ap = pool_elt_at_index (tm->subifs, p[0]);
  else
    {
      pool_get (tm->subifs, ap);
      *ap = subif_addr;
      mhash_set (&tm->subif_mhash, ap, ap - tm->subifs, 0);
    }

  /* Use subif pool index to select alias device. */
  memset (&ifr, 0, sizeof (ifr));
  snprintf (ifr.ifr_name, sizeof(ifr.ifr_name), 
            "%s:%d", tm->tun_name, (int)(ap - tm->subifs));

  /* the tuntap punt/inject is enabled for IPv4 RX so long as
   * any vpp interface has an IPv4 address.
   * this is also ref counted.
   */
  ip4_sw_interface_enable_disable (tm->sw_if_index, !is_delete);

  if (! is_delete)
    {
      struct sockaddr_in * sin;

      sin = (struct sockaddr_in *)&ifr.ifr_addr;

      /* Set ipv4 address, netmask. */
      sin->sin_family = AF_INET;
      clib_memcpy (&sin->sin_addr.s_addr, address, 4);
      if (ioctl (tm->dev_tap_fd, SIOCSIFADDR, &ifr) < 0)
	clib_unix_warning ("ioctl SIOCSIFADDR");
    
      sin->sin_addr.s_addr = im->fib_masks[address_length];
      if (ioctl (tm->dev_tap_fd, SIOCSIFNETMASK, &ifr) < 0)
	clib_unix_warning ("ioctl SIOCSIFNETMASK");
    }
  else
    {
      mhash_unset (&tm->subif_mhash, &subif_addr, 0 /* old value ptr */);
      pool_put (tm->subifs, ap);
    }

  /* get flags, modify to bring up interface... */
  if (ioctl (tm->dev_tap_fd, SIOCGIFFLAGS, &ifr) < 0)
    clib_unix_warning ("ioctl SIOCGIFFLAGS");

  if (is_delete)
    ifr.ifr_flags &= ~(IFF_UP | IFF_RUNNING);
  else
    ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);

  if (ioctl (tm->dev_tap_fd, SIOCSIFFLAGS, &ifr) < 0)
    clib_unix_warning ("ioctl SIOCSIFFLAGS");
}

/**
 * @brief workaround for a known include file bug.
 * including @c <linux/ipv6.h> causes multiple definitions if
 * @c <netinet/in.h is also included.
 */
struct in6_ifreq {
	struct in6_addr	ifr6_addr;
        u32		ifr6_prefixlen;
        int		ifr6_ifindex;
};

/**
 * @brief Add or Del tun/tap interface address.
 *
 * Both the v6 interface address API and the way ifconfig
 * displays subinterfaces differ from their v4 couterparts.
 * The code given here seems to work but YMMV.
 *
 * @param *im - ip6_main_t
 * @param opaque - uword
 * @param sw_if_index - u32
 * @param *address - ip6_address_t
 * @param address_length - u32
 * @param if_address_index - u32
 * @param is_delete - u32
 */
void
tuntap_ip6_add_del_interface_address (ip6_main_t * im,
				      uword opaque,
				      u32 sw_if_index,
				      ip6_address_t * address,
				      u32 address_length,
				      u32 if_address_index,
				      u32 is_delete)
{
  tuntap_main_t * tm = &tuntap_main;
  struct ifreq ifr;
  struct in6_ifreq ifr6;
  subif_address_t subif_addr, * ap;
  uword * p;

  /* Tuntap disabled, or using a "normal" interface. */
  if (tm->have_normal_interface ||  tm->dev_tap_fd < 0)
    return;

  /* if the address is being applied to an interface that is not in
   * the same table/VRF as this tap, then ignore it.
   * If we don't do this overlapping address spaces in the diferent tables
   * breaks the linux host's routing tables */
  if (fib_table_get_index_for_sw_if_index(FIB_PROTOCOL_IP6,
                                          sw_if_index) !=
      fib_table_get_index_for_sw_if_index(FIB_PROTOCOL_IP6,
                                          tm->sw_if_index))
      return;

  /* See if we already know about this subif */
  memset (&subif_addr, 0, sizeof (subif_addr));
  subif_addr.sw_if_index = sw_if_index;
  subif_addr.is_v6 = 1;
  clib_memcpy (&subif_addr.addr, address, sizeof (*address));

  p = mhash_get (&tm->subif_mhash, &subif_addr);

  if (p)
    ap = pool_elt_at_index (tm->subifs, p[0]);
  else
    {
      pool_get (tm->subifs, ap);
      *ap = subif_addr;
      mhash_set (&tm->subif_mhash, ap, ap - tm->subifs, 0);
    }

  /* Use subif pool index to select alias device. */
  memset (&ifr, 0, sizeof (ifr));
  memset (&ifr6, 0, sizeof (ifr6));
  snprintf (ifr.ifr_name, sizeof(ifr.ifr_name), 
            "%s:%d", tm->tun_name, (int)(ap - tm->subifs));

  /* the tuntap punt/inject is enabled for IPv6 RX so long as
   * any vpp interface has an IPv6 address.
   * this is also ref counted.
   */
  ip6_sw_interface_enable_disable (tm->sw_if_index, !is_delete);

  if (! is_delete)
    {
      int sockfd = socket (AF_INET6, SOCK_STREAM, 0);
      if (sockfd < 0)
        clib_unix_warning ("get ifindex socket");

      if (ioctl (sockfd, SIOGIFINDEX, &ifr) < 0)
        clib_unix_warning ("get ifindex");

      ifr6.ifr6_ifindex = ifr.ifr_ifindex;
      ifr6.ifr6_prefixlen = address_length;
      clib_memcpy (&ifr6.ifr6_addr, address, 16);

      if (ioctl (sockfd, SIOCSIFADDR, &ifr6) < 0)
        clib_unix_warning ("set address");

      if (sockfd >= 0)
        close (sockfd);
    }
  else
    {
      int sockfd = socket (AF_INET6, SOCK_STREAM, 0);
      if (sockfd < 0)
        clib_unix_warning ("get ifindex socket");

      if (ioctl (sockfd, SIOGIFINDEX, &ifr) < 0)
        clib_unix_warning ("get ifindex");

      ifr6.ifr6_ifindex = ifr.ifr_ifindex;
      ifr6.ifr6_prefixlen = address_length;
      clib_memcpy (&ifr6.ifr6_addr, address, 16);

      if (ioctl (sockfd, SIOCDIFADDR, &ifr6) < 0)
        clib_unix_warning ("del address");

      if (sockfd >= 0)
        close (sockfd);

      mhash_unset (&tm->subif_mhash, &subif_addr, 0 /* old value ptr */);
      pool_put (tm->subifs, ap);
    }
}

/**
 * @brief TX the tun/tap frame
 *
 * @param *vm - vlib_main_t
 * @param *node - vlib_node_runtime_t
 * @param *frame - vlib_frame_t
 *
 */
static void
tuntap_punt_frame (vlib_main_t * vm,
                   vlib_node_runtime_t * node,
                   vlib_frame_t * frame)
{
  tuntap_tx (vm, node, frame);
  vlib_frame_free (vm, node, frame);
}

/**
 * @brief Free the tun/tap frame
 *
 * @param *vm - vlib_main_t
 * @param *node - vlib_node_runtime_t
 * @param *frame - vlib_frame_t
 *
 */
static void
tuntap_nopunt_frame (vlib_main_t * vm,
                   vlib_node_runtime_t * node,
                   vlib_frame_t * frame)
{
  u32 * buffers = vlib_frame_args (frame);
  uword n_packets = frame->n_vectors;
  vlib_buffer_free (vm, buffers, n_packets);
  vlib_frame_free (vm, node, frame);
}

VNET_HW_INTERFACE_CLASS (tuntap_interface_class,static) = {
  .name = "tuntap",
  .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
};

/**
 * @brief Format tun/tap interface name
 *
 * @param *s - u8 - formatter string
 * @param *args - va_list
 *
 * @return *s - u8 - formatted string
 *
 */
static u8 * format_tuntap_interface_name (u8 * s, va_list * args)
{
  u32 i = va_arg (*args, u32);

  s = format (s, "tuntap-%d", i);
  return s;
}

/**
 * @brief TX packet out tun/tap
 *
 * @param *vm - vlib_main_t
 * @param *node - vlib_node_runtime_t
 * @param *frame - vlib_frame_t
 *
 * @return n_buffers - uword - Packets transmitted
 *
 */
static uword
tuntap_intfc_tx (vlib_main_t * vm,
		 vlib_node_runtime_t * node,
		 vlib_frame_t * frame)
{
  tuntap_main_t * tm = &tuntap_main;
  u32 * buffers = vlib_frame_args (frame);
  uword n_buffers = frame->n_vectors;

  /* Normal interface transmit happens only on the normal interface... */
  if (tm->have_normal_interface)
    return tuntap_tx (vm, node, frame);

  vlib_buffer_free (vm, buffers, n_buffers);
  return n_buffers;
}

VNET_DEVICE_CLASS (tuntap_dev_class,static) = {
  .name = "tuntap",
  .tx_function = tuntap_intfc_tx,
  .format_device_name = format_tuntap_interface_name,
};

/**
 * @brief tun/tap node init
 *
 * @param *vm - vlib_main_t
 *
 * @return error - clib_error_t
 *
 */
static clib_error_t *
tuntap_init (vlib_main_t * vm)
{
  clib_error_t * error;
  ip4_main_t * im4 = &ip4_main;
  ip6_main_t * im6 = &ip6_main;
  ip4_add_del_interface_address_callback_t cb4;
  ip6_add_del_interface_address_callback_t cb6;
  tuntap_main_t * tm = &tuntap_main;

  error = vlib_call_init_function (vm, ip4_init);
  if (error)
    return error;

  mhash_init (&tm->subif_mhash, sizeof (u32), sizeof(subif_address_t));

  cb4.function = tuntap_ip4_add_del_interface_address;
  cb4.function_opaque = 0;
  vec_add1 (im4->add_del_interface_address_callbacks, cb4);

  cb6.function = tuntap_ip6_add_del_interface_address;
  cb6.function_opaque = 0;
  vec_add1 (im6->add_del_interface_address_callbacks, cb6);

  return 0;
}

VLIB_INIT_FUNCTION (tuntap_init);