Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 1000 insertions, 0 deletions

diff --git a/src/vnet/unix/tuntap.c b/src/vnet/unix/tuntap.c
new file mode 100644
index 00000000000..4a5dd676a68
--- /dev/null
+++ b/src/vnet/unix/tuntap.c
@@ -0,0 +1,1000 @@
+/* 
+ *------------------------------------------------------------------
+ * 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/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/writev calls. */
+  struct iovec * 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 unix_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->iovecs)
+	_vec_len (tm->iovecs) = 0;
+
+      /** VLIB buffer chain -> Unix iovec(s). */
+      vec_add2 (tm->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->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->iovecs, vec_len (tm->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->cpu_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->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->iovecs[i].iov_base = b->data;
+	tm->iovecs[i].iov_len = buffer_size;
+      }
+
+    n_bytes_left = readv (tm->dev_net_tun_fd, tm->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,
+         os_get_cpu_number(),
+         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, 0);
+
+    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 - unix_file_t
+ *
+ * @return error - clib_error_t
+ */
+static clib_error_t * tuntap_read_ready (unix_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);
+    }
+
+  {
+    unix_file_t template = {0};
+    template.read_function = tuntap_read_ready;
+    template.file_descriptor = tm->dev_net_tun_fd;
+    tm->unix_file_index = unix_file_add (&unix_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;
+
+  /** 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;
+
+  /* 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);