# Copyright (c) 2016 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.

"""QEMU utilities library."""

from time import time, sleep
import json
import re

from robot.api import logger

from resources.libraries.python.ssh import SSH
from resources.libraries.python.constants import Constants
from resources.libraries.python.topology import NodeType


class QemuUtils(object):
    """QEMU utilities."""

    __QEMU_BIN = '/opt/qemu/bin/qemu-system-x86_64'
    # QEMU Machine Protocol socket
    __QMP_SOCK = '/tmp/qmp.sock'
    # QEMU Guest Agent socket
    __QGA_SOCK = '/tmp/qga.sock'

    def __init__(self):
        self._qemu_opt = {}
        # Default 1 CPU.
        self._qemu_opt['smp'] = '-smp 1,sockets=1,cores=1,threads=1'
        # Daemonize the QEMU process after initialization. Default one
        # management interface.
        self._qemu_opt['options'] = '-daemonize -enable-kvm ' \
            '-machine pc-1.0,accel=kvm,usb=off,mem-merge=off ' \
            '-net nic,macaddr=52:54:00:00:02:01'
        self._qemu_opt['ssh_fwd_port'] = 10022
        # Default serial console port
        self._qemu_opt['serial_port'] = 4556
        # Default 512MB virtual RAM
        self._qemu_opt['mem_size'] = 512
        # Default huge page mount point, required for Vhost-user interfaces.
        self._qemu_opt['huge_mnt'] = '/mnt/huge'
        # Default im
/*
 *------------------------------------------------------------------
 * 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 per thread struct
 */
typedef struct
{
  /** Vector of VLIB rx buffers to use.  We allocate them in blocks
     of VLIB_FRAME_SIZE (256). */
  u32 *rx_buffers;

  /** Vector of iovecs for readv/writev calls. */
  struct iovec *iovecs;
} tuntap_per_thread_t;

/**
 * @brief TUNTAP node main state
 */
typedef struct
{
  /** per thread variables */
  tuntap_per_thread_t *threads;

  /** 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_vector_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;
  u16 thread_index = vm->thread_index;

  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_fast (vlib_buffer_get_current (b), tm->ether_dst_mac,
			    6);
	}

      /* Re-set iovecs if present. */
      if (tm->threads[thread_index].iovecs)
	_vec_len (tm->threads[thread_index].iovecs) = 0;

      /** VLIB buffer chain -> Unix iovec(s). */
      vec_add2 (tm->threads[thread_index].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->threads[thread_index].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->threads[thread_index].iovecs,
		  vec_len (tm->threads[thread_index].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;
}

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

/**
 * @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_get_default_data_size (vm);
  u16 thread_index = vm->thread_index;

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

    if (n_left < VLIB_FRAME_SIZE / 2)
      {
	if (!tm->threads[thread_index].rx_buffers)
	  vec_alloc (tm->threads[thread_index].rx_buffers, VLIB_FRAME_SIZE);

	n_alloc =
	  vlib_buffer_alloc (vm,
			     tm->threads[thread_index].rx_buffers + n_left,
			     VLIB_FRAME_SIZE - n_left);
	_vec_len (tm->threads[thread_index].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->threads[thread_index].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->threads[thread_index].rx_buffers) >=
	    tm->mtu_buffers);

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

    n_bytes_left =
      readv (tm->dev_net_tun_fd, tm->threads[thread_index].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->threads[thread_index].rx_buffers[i_rx];

    while (1)
      {
	b = vlib_get_buffer (vm, tm->threads[thread_index].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->threads[thread_index].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,
       thread_index, tm->sw_if_index, 1, n_bytes_in_packet);

    _vec_len (tm->threads[thread_index].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",
};

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (tuntap_rx_node,static) = {
  .function = tuntap_rx,
  .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
  .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,
};
/* *INDENT-ON* */

/**
 * @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");

  clib_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_get_default_data_size (vm);

  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;
    }

  clib_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;

    clib_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. */
    clib_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_fast (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 different 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 */
  clib_memset (&subif_addr, 0, sizeof (subif_addr));
  subif_addr.sw_if_index = sw_if_index;
  clib_memcpy_fast (&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. */
  clib_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_fast (&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 counterparts.
 * 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 different 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 */
  clib_memset (&subif_addr, 0, sizeof (subif_addr));
  subif_addr.sw_if_index = sw_if_index;
  subif_addr.is_v6 = 1;
  clib_memcpy_fast (&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. */
  clib_memset (&ifr, 0, sizeof (ifr));
  clib_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_fast (&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_fast (&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_vector_args (frame);
  uword n_packets = frame->n_vectors;
  vlib_buffer_free (vm, buffers, n_packets);
  vlib_frame_free (vm, node, frame);
}

/* *INDENT-OFF* */
VNET_HW_INTERFACE_CLASS (tuntap_interface_class,static) = {
  .name = "tuntap",
  .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
};
/* *INDENT-ON* */

/**
 * @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_vector_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;
}

/* *INDENT-OFF* */
VNET_DEVICE_CLASS (tuntap_dev_class,static) = {
  .name = "tuntap",
  .tx_function = tuntap_intfc_tx,
  .format_device_name = format_tuntap_interface_name,
};
/* *INDENT-ON* */

/**
 * @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)
{
  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;
  vlib_thread_main_t *m = vlib_get_thread_main ();

  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);
  vec_validate_aligned (tm->threads, m->n_vlib_mains - 1,
			CLIB_CACHE_LINE_BYTES);

  return 0;
}

/* *INDENT-OFF* */
VLIB_INIT_FUNCTION (tuntap_init) =
{
  .runs_after = VLIB_INITS("ip4_init"),
};
/* *INDENT-ON* */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */