Reorganize source tree to use single autotools instance

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

1 files changed, 1328 insertions, 0 deletions

diff --git a/src/vnet/unix/tapcli.c b/src/vnet/unix/tapcli.c
new file mode 100644
index 00000000000..9862a2bda50
--- /dev/null
+++ b/src/vnet/unix/tapcli.c
@@ -0,0 +1,1328 @@
+/*
+ *------------------------------------------------------------------
+ * tapcli.c - dynamic tap interface hookup
+ *
+ * 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  dynamic tap interface hookup
+ */
+
+#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/feature/feature.h>
+#include <vnet/devices/devices.h>
+#include <vnet/unix/tapcli.h>
+
+static vnet_device_class_t tapcli_dev_class;
+static vnet_hw_interface_class_t tapcli_interface_class;
+static vlib_node_registration_t tapcli_rx_node;
+
+static void tapcli_nopunt_frame (vlib_main_t * vm,
+                                 vlib_node_runtime_t * node,
+                                 vlib_frame_t * frame);
+/**
+ * @brief Struct for the tapcli interface
+ */
+typedef struct {
+  u32 unix_fd;
+  u32 unix_file_index;
+  u32 provision_fd;
+  /** For counters */
+  u32 sw_if_index;
+  u32 hw_if_index;
+  u32 is_promisc;
+  struct ifreq ifr;
+  u32 per_interface_next_index;
+  /** for delete */
+  u8 active;
+} tapcli_interface_t;
+
+/**
+ * @brief Struct for RX trace
+ */
+typedef struct {
+  u16 sw_if_index;
+} tapcli_rx_trace_t;
+
+/**
+ * @brief Function to format TAP CLI trace
+ *
+ * @param *s - u8 - formatting string
+ * @param *va - va_list
+ *
+ * @return *s - u8 - formatted string
+ *
+ */
+u8 * format_tapcli_rx_trace (u8 * s, va_list * va)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
+  vnet_main_t * vnm = vnet_get_main();
+  tapcli_rx_trace_t * t = va_arg (*va, tapcli_rx_trace_t *);
+  s = format (s, "%U", format_vnet_sw_if_index_name,
+                vnm, t->sw_if_index);
+  return s;
+}
+
+/**
+ * @brief TAPCLI main state struct
+ */
+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;
+
+  /** 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;
+
+  /** Vector of tap interfaces */
+  tapcli_interface_t * tapcli_interfaces;
+
+  /** Vector of deleted tap interfaces */
+  u32 * tapcli_inactive_interfaces;
+
+  /** Bitmap of tap interfaces with pending reads */
+  uword * pending_read_bitmap;
+
+  /** Hash table to find tapcli interface given hw_if_index */
+  uword * tapcli_interface_index_by_sw_if_index;
+
+  /** Hash table to find tapcli interface given unix fd */
+  uword * tapcli_interface_index_by_unix_fd;
+
+  /** renumbering table */
+  u32 * show_dev_instance_by_real_dev_instance;
+
+  /** 1 => disable CLI */
+  int is_disabled;
+
+  /** convenience - vlib_main_t */
+  vlib_main_t * vlib_main;
+  /** convenience - vnet_main_t */
+  vnet_main_t * vnet_main;
+  /** convenience - unix_main_t */
+  unix_main_t * unix_main;
+} tapcli_main_t;
+
+static tapcli_main_t tapcli_main;
+
+/**
+ * @brief tapcli TX node function
+ * @node tap-cli-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 n_packets - uword
+ *
+ */
+static uword
+tapcli_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;
+  tapcli_main_t * tm = &tapcli_main;
+  tapcli_interface_t * ti;
+  int i;
+
+  for (i = 0; i < n_packets; i++)
+    {
+      struct iovec * iov;
+      vlib_buffer_t * b;
+      uword l;
+      vnet_hw_interface_t * hw;
+      uword * p;
+      u32 tx_sw_if_index;
+
+      b = vlib_get_buffer (vm, buffers[i]);
+
+      tx_sw_if_index = vnet_buffer(b)->sw_if_index[VLIB_TX];
+      if (tx_sw_if_index == (u32)~0)
+        tx_sw_if_index = vnet_buffer(b)->sw_if_index[VLIB_RX];
+        
+      ASSERT(tx_sw_if_index != (u32)~0);
+
+      /* Use the sup intfc to finesse vlan subifs */
+      hw = vnet_get_sup_hw_interface (tm->vnet_main, tx_sw_if_index);
+      tx_sw_if_index = hw->sw_if_index;
+
+      p = hash_get (tm->tapcli_interface_index_by_sw_if_index, 
+                    tx_sw_if_index);
+      if (p == 0)
+        {
+          clib_warning ("sw_if_index %d unknown", tx_sw_if_index);
+          /* $$$ leak, but this should never happen... */
+          continue;
+        }
+      else
+        ti = vec_elt_at_index (tm->tapcli_interfaces, p[0]);
+
+      /* 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 (ti->unix_fd, tm->iovecs, vec_len (tm->iovecs)) < l)
+	clib_unix_warning ("writev");
+    }
+
+  vlib_buffer_free(vm, vlib_frame_vector_args(frame), frame->n_vectors);
+
+  return n_packets;
+}
+
+VLIB_REGISTER_NODE (tapcli_tx_node,static) = {
+  .function = tapcli_tx,
+  .name = "tapcli-tx",
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .vector_size = 4,
+};
+
+/**
+ * @brief Dispatch tapcli RX node function for node tap_cli_rx
+ *
+ *
+ * @param *vm - vlib_main_t
+ * @param *node - vlib_node_runtime_t
+ * @param *ti - tapcli_interface_t
+ *
+ * @return n_packets - uword
+ *
+ */
+static uword tapcli_rx_iface(vlib_main_t * vm,
+                            vlib_node_runtime_t * node,
+                            tapcli_interface_t * ti)
+{
+  tapcli_main_t * tm = &tapcli_main;
+  const uword buffer_size = VLIB_BUFFER_DATA_SIZE;
+  u32 n_trace = vlib_get_trace_count (vm, node);
+  u8 set_trace = 0;
+
+  vnet_main_t *vnm;
+  vnet_sw_interface_t * si;
+  u8 admin_down;
+  u32 next = node->cached_next_index;
+  u32 n_left_to_next, next_index;
+  u32 *to_next;
+
+  vnm = vnet_get_main();
+  si = vnet_get_sw_interface (vnm, ti->sw_if_index);
+  admin_down = !(si->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP);
+
+  vlib_get_next_frame(vm, node, next, to_next, n_left_to_next);
+
+  while (n_left_to_next) { // Fill at most one vector
+    vlib_buffer_t *b_first, *b, *prev;
+    u32 bi_first, bi;
+    word n_bytes_in_packet;
+    int j, n_bytes_left;
+
+    if (PREDICT_FALSE(vec_len(tm->rx_buffers) < tm->mtu_buffers)) {
+      uword len = vec_len(tm->rx_buffers);
+      _vec_len(tm->rx_buffers) +=
+          vlib_buffer_alloc_from_free_list(vm, &tm->rx_buffers[len],
+                            VLIB_FRAME_SIZE - len, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+      if (PREDICT_FALSE(vec_len(tm->rx_buffers) < tm->mtu_buffers)) {
+          vlib_node_increment_counter(vm, tapcli_rx_node.index,
+                                      TAPCLI_ERROR_BUFFER_ALLOC,
+                                      tm->mtu_buffers - vec_len(tm->rx_buffers));
+        break;
+      }
+    }
+
+    uword i_rx = vec_len (tm->rx_buffers) - 1;
+
+    /* Allocate RX buffers from end of rx_buffers.
+           Turn them into iovecs to pass to readv. */
+    vec_validate (tm->iovecs, tm->mtu_buffers - 1);
+    for (j = 0; j < tm->mtu_buffers; j++) {
+      b = vlib_get_buffer (vm, tm->rx_buffers[i_rx - j]);
+      tm->iovecs[j].iov_base = b->data;
+      tm->iovecs[j].iov_len = buffer_size;
+    }
+
+    n_bytes_left = readv (ti->unix_fd, tm->iovecs, tm->mtu_buffers);
+    n_bytes_in_packet = n_bytes_left;
+    if (n_bytes_left <= 0) {
+      if (errno != EAGAIN) {
+        vlib_node_increment_counter(vm, tapcli_rx_node.index,
+                                    TAPCLI_ERROR_READ, 1);
+      }
+      break;
+    }
+
+    bi_first = tm->rx_buffers[i_rx];
+    b = b_first = vlib_get_buffer (vm, tm->rx_buffers[i_rx]);
+    prev = NULL;
+
+    while (1) {
+      b->current_length = n_bytes_left < buffer_size ? n_bytes_left : buffer_size;
+      n_bytes_left -= buffer_size;
+
+      if (prev) {
+        prev->next_buffer = bi;
+        prev->flags |= VLIB_BUFFER_NEXT_PRESENT;
+      }
+      prev = b;
+
+      /* last segment */
+      if (n_bytes_left <= 0)
+        break;
+
+      i_rx--;
+      bi = tm->rx_buffers[i_rx];
+      b = vlib_get_buffer (vm, bi);
+    }
+
+    _vec_len (tm->rx_buffers) = i_rx;
+
+    b_first->total_length_not_including_first_buffer =
+        (n_bytes_in_packet > buffer_size) ? n_bytes_in_packet - buffer_size : 0;
+    b_first->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
+
+    VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b_first);
+
+    vnet_buffer (b_first)->sw_if_index[VLIB_RX] = ti->sw_if_index;
+    vnet_buffer (b_first)->sw_if_index[VLIB_TX] = (u32)~0;
+
+    b_first->error = node->errors[TAPCLI_ERROR_NONE];
+    next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+    next_index = (ti->per_interface_next_index != ~0) ?
+        ti->per_interface_next_index : next_index;
+    next_index = admin_down ? VNET_DEVICE_INPUT_NEXT_DROP : next_index;
+
+    to_next[0] = bi_first;
+    to_next++;
+    n_left_to_next--;
+
+    vnet_feature_start_device_input_x1 (ti->sw_if_index, &next_index, 
+                                        b_first, 0);
+
+    vlib_validate_buffer_enqueue_x1 (vm, node, next,
+                                     to_next, n_left_to_next,
+                                     bi_first, next_index);
+
+    /* Interface counters for tapcli interface. */
+    if (PREDICT_TRUE(!admin_down)) {
+      vlib_increment_combined_counter (
+          vnet_main.interface_main.combined_sw_if_counters
+          + VNET_INTERFACE_COUNTER_RX,
+          os_get_cpu_number(), ti->sw_if_index,
+          1, n_bytes_in_packet);
+
+      if (PREDICT_FALSE(n_trace > 0)) {
+        vlib_trace_buffer (vm, node, next_index,
+                           b_first, /* follow_chain */ 1);
+        n_trace--;
+        set_trace = 1;
+        tapcli_rx_trace_t *t0 = vlib_add_trace (vm, node, b_first, sizeof (*t0));
+        t0->sw_if_index = si->sw_if_index;
+      }
+    }
+  }
+  vlib_put_next_frame (vm, node, next, n_left_to_next);
+  if (set_trace)
+    vlib_set_trace_count (vm, node, n_trace);
+  return VLIB_FRAME_SIZE - n_left_to_next;
+}
+
+/**
+ * @brief tapcli RX node function
+ * @node tap-cli-rx
+ *
+ * Input node from the Kernel tun/tap device
+ *
+ * @param *vm - vlib_main_t
+ * @param *node - vlib_node_runtime_t
+ * @param *frame - vlib_frame_t
+ *
+ * @return n_packets - uword
+ *
+ */
+static uword
+tapcli_rx (vlib_main_t * vm,
+	   vlib_node_runtime_t * node,
+	   vlib_frame_t * frame)
+{
+  tapcli_main_t * tm = &tapcli_main;
+  static u32 * ready_interface_indices;
+  tapcli_interface_t * ti;
+  int i;
+  u32 total_count = 0;
+
+  vec_reset_length (ready_interface_indices);
+  clib_bitmap_foreach (i, tm->pending_read_bitmap,
+  ({
+    vec_add1 (ready_interface_indices, i);
+  }));
+
+  if (vec_len (ready_interface_indices) == 0)
+    return 0;
+
+  for (i = 0; i < vec_len(ready_interface_indices); i++)
+  {
+    tm->pending_read_bitmap =
+        clib_bitmap_set (tm->pending_read_bitmap,
+                         ready_interface_indices[i], 0);
+
+    ti = vec_elt_at_index (tm->tapcli_interfaces, ready_interface_indices[i]);
+    total_count += tapcli_rx_iface(vm, node, ti);
+  }
+  return total_count; //This might return more than 256.
+}
+
+/** TAPCLI error strings */
+static char * tapcli_rx_error_strings[] = {
+#define _(sym,string) string,
+  foreach_tapcli_error
+#undef _
+};
+
+VLIB_REGISTER_NODE (tapcli_rx_node, static) = {
+  .function = tapcli_rx,
+  .name = "tapcli-rx",
+  .sibling_of = "device-input",
+  .type = VLIB_NODE_TYPE_INPUT,
+  .state = VLIB_NODE_STATE_INTERRUPT,
+  .vector_size = 4,
+  .n_errors = TAPCLI_N_ERROR,
+  .error_strings = tapcli_rx_error_strings,
+  .format_trace = format_tapcli_rx_trace,
+};
+
+
+/**
+ * @brief Gets called when file descriptor is ready from epoll.
+ *
+ * @param *uf - unix_file_t
+ *
+ * @return error - clib_error_t
+ *
+ */
+static clib_error_t * tapcli_read_ready (unix_file_t * uf)
+{
+  vlib_main_t * vm = vlib_get_main();
+  tapcli_main_t * tm = &tapcli_main;
+  uword * p;
+
+  /** Schedule the rx node */
+  vlib_node_set_interrupt_pending (vm, tapcli_rx_node.index);
+
+  p = hash_get (tm->tapcli_interface_index_by_unix_fd, uf->file_descriptor);
+
+  /** Mark the specific tap interface ready-to-read */
+  if (p)
+    tm->pending_read_bitmap = clib_bitmap_set (tm->pending_read_bitmap,
+                                               p[0], 1);
+  else
+    clib_warning ("fd %d not in hash table", uf->file_descriptor);
+
+  return 0;
+}
+
+/**
+ * @brief CLI function for TAPCLI configuration
+ *
+ * @param *vm - vlib_main_t
+ * @param *input - unformat_input_t
+ *
+ * @return error - clib_error_t
+ *
+ */
+static clib_error_t *
+tapcli_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  tapcli_main_t *tm = &tapcli_main;
+  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, "disable"))
+        tm->is_disabled = 1;
+      else
+          return clib_error_return (0, "unknown input `%U'",
+                                    format_unformat_error, input);
+    }
+
+  if (tm->is_disabled)
+    return 0;
+
+  if (geteuid())
+    {
+      clib_warning ("tapcli disabled: must be superuser");
+      tm->is_disabled = 1;
+      return 0;
+    }
+
+  tm->mtu_buffers = (tm->mtu_bytes + (buffer_size - 1)) / buffer_size;
+
+  return 0;
+}
+
+/**
+ * @brief Renumber TAPCLI interface
+ *
+ * @param *hi - vnet_hw_interface_t
+ * @param new_dev_instance - u32
+ *
+ * @return rc - int
+ *
+ */
+static int tap_name_renumber (vnet_hw_interface_t * hi,
+                              u32 new_dev_instance)
+{
+  tapcli_main_t *tm = &tapcli_main;
+
+  vec_validate_init_empty (tm->show_dev_instance_by_real_dev_instance,
+                           hi->dev_instance, ~0);
+
+  tm->show_dev_instance_by_real_dev_instance [hi->dev_instance] =
+    new_dev_instance;
+
+  return 0;
+}
+
+VLIB_CONFIG_FUNCTION (tapcli_config, "tapcli");
+
+/**
+ * @brief Free "no punt" frame
+ *
+ * @param *vm - vlib_main_t
+ * @param *node - vlib_node_runtime_t
+ * @param *frame - vlib_frame_t
+ *
+ */
+static void
+tapcli_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 (tapcli_interface_class,static) = {
+  .name = "tapcli",
+  .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
+};
+
+/**
+ * @brief Formatter for TAPCLI interface name
+ *
+ * @param *s - formatter string
+ * @param *args - va_list
+ *
+ * @return *s - formatted string
+ *
+ */
+static u8 * format_tapcli_interface_name (u8 * s, va_list * args)
+{
+  u32 i = va_arg (*args, u32);
+  u32 show_dev_instance = ~0;
+  tapcli_main_t * tm = &tapcli_main;
+
+  if (i < vec_len (tm->show_dev_instance_by_real_dev_instance))
+    show_dev_instance = tm->show_dev_instance_by_real_dev_instance[i];
+
+  if (show_dev_instance != ~0)
+    i = show_dev_instance;
+
+  s = format (s, "tap-%d", i);
+  return s;
+}
+
+/**
+ * @brief Modify interface flags for TAPCLI interface
+ *
+ * @param *vnm - vnet_main_t
+ * @param *hw - vnet_hw_interface_t
+ * @param flags - u32
+ *
+ * @return rc - u32
+ *
+ */
+static u32 tapcli_flag_change (vnet_main_t * vnm,
+                               vnet_hw_interface_t * hw,
+                               u32 flags)
+{
+  tapcli_main_t *tm = &tapcli_main;
+  tapcli_interface_t *ti;
+
+   ti = vec_elt_at_index (tm->tapcli_interfaces, hw->dev_instance);
+
+  if (flags & ETHERNET_INTERFACE_FLAG_MTU)
+    {
+      const uword buffer_size = VLIB_BUFFER_DATA_SIZE;
+      tm->mtu_bytes = hw->max_packet_bytes;
+      tm->mtu_buffers = (tm->mtu_bytes + (buffer_size - 1)) / buffer_size;
+    }
+   else
+    {
+      struct ifreq ifr;
+      u32 want_promisc;
+
+      memcpy (&ifr, &ti->ifr, sizeof (ifr));
+
+      /* get flags, modify to bring up interface... */
+      if (ioctl (ti->provision_fd, SIOCGIFFLAGS, &ifr) < 0)
+        {
+          clib_unix_warning ("Couldn't get interface flags for %s", hw->name);
+          return 0;
+        }
+
+      want_promisc = (flags & ETHERNET_INTERFACE_FLAG_ACCEPT_ALL) != 0;
+
+      if (want_promisc == ti->is_promisc)
+        return 0;
+
+      if (flags & ETHERNET_INTERFACE_FLAG_ACCEPT_ALL)
+        ifr.ifr_flags |= IFF_PROMISC;
+      else
+        ifr.ifr_flags &= ~(IFF_PROMISC);
+
+      /* get flags, modify to bring up interface... */
+      if (ioctl (ti->provision_fd, SIOCSIFFLAGS, &ifr) < 0)
+        {
+          clib_unix_warning ("Couldn't set interface flags for %s", hw->name);
+          return 0;
+        }
+
+      ti->is_promisc = want_promisc;
+    }
+
+  return 0;
+}
+
+/**
+ * @brief Setting the TAP interface's next processing node
+ *
+ * @param *vnm - vnet_main_t
+ * @param hw_if_index - u32
+ * @param node_index - u32
+ *
+ */
+static void tapcli_set_interface_next_node (vnet_main_t *vnm,
+                                            u32 hw_if_index,
+                                            u32 node_index)
+{
+  tapcli_main_t *tm = &tapcli_main;
+  tapcli_interface_t *ti;
+  vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
+
+  ti = vec_elt_at_index (tm->tapcli_interfaces, hw->dev_instance);
+
+  /** Shut off redirection */
+  if (node_index == ~0)
+    {
+      ti->per_interface_next_index = node_index;
+      return;
+    }
+
+  ti->per_interface_next_index =
+    vlib_node_add_next (tm->vlib_main, tapcli_rx_node.index, node_index);
+}
+
+/**
+ * @brief Set link_state == admin_state otherwise things like ip6 neighbor discovery breaks
+ *
+ * @param *vnm - vnet_main_t
+ * @param hw_if_index - u32
+ * @param flags - u32
+ *
+ * @return error - clib_error_t
+ */
+static clib_error_t *
+tapcli_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  uword is_admin_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
+  u32 hw_flags;
+  u32 speed_duplex = VNET_HW_INTERFACE_FLAG_FULL_DUPLEX
+    | VNET_HW_INTERFACE_FLAG_SPEED_1G;
+
+  if (is_admin_up)
+    hw_flags = VNET_HW_INTERFACE_FLAG_LINK_UP | speed_duplex;
+  else
+    hw_flags = speed_duplex;
+
+  vnet_hw_interface_set_flags (vnm, hw_if_index, hw_flags);
+  return 0;
+}
+
+VNET_DEVICE_CLASS (tapcli_dev_class,static) = {
+  .name = "tapcli",
+  .tx_function = tapcli_tx,
+  .format_device_name = format_tapcli_interface_name,
+  .rx_redirect_to_node = tapcli_set_interface_next_node,
+  .name_renumber = tap_name_renumber,
+  .admin_up_down_function = tapcli_interface_admin_up_down,
+};
+
+/**
+ * @brief Dump TAP interfaces
+ *
+ * @param **out_tapids - tapcli_interface_details_t
+ *
+ * @return rc - int
+ *
+ */
+int vnet_tap_dump_ifs (tapcli_interface_details_t **out_tapids)
+{
+  tapcli_main_t * tm = &tapcli_main;
+  tapcli_interface_t * ti;
+
+  tapcli_interface_details_t * r_tapids = NULL;
+  tapcli_interface_details_t * tapid = NULL;
+
+  vec_foreach (ti, tm->tapcli_interfaces) {
+    if (!ti->active)
+        continue;
+    vec_add2(r_tapids, tapid, 1);
+    tapid->sw_if_index = ti->sw_if_index;
+    strncpy((char *)tapid->dev_name, ti->ifr.ifr_name, sizeof (ti->ifr.ifr_name)-1);
+  }
+
+  *out_tapids = r_tapids;
+
+  return 0;
+}
+
+/**
+ * @brief Get tap interface from inactive interfaces or create new
+ *
+ * @return interface - tapcli_interface_t
+ *
+ */
+static tapcli_interface_t *tapcli_get_new_tapif()
+{
+  tapcli_main_t * tm = &tapcli_main;
+  tapcli_interface_t *ti = NULL;
+
+  int inactive_cnt = vec_len(tm->tapcli_inactive_interfaces);
+  // if there are any inactive ifaces
+  if (inactive_cnt > 0) {
+    // take last
+    u32 ti_idx = tm->tapcli_inactive_interfaces[inactive_cnt - 1];
+    if (vec_len(tm->tapcli_interfaces) > ti_idx) {
+      ti = vec_elt_at_index (tm->tapcli_interfaces, ti_idx);
+      clib_warning("reusing tap interface");
+    }
+    // "remove" from inactive list
+    _vec_len(tm->tapcli_inactive_interfaces) -= 1;
+  }
+
+  // ti was not retrieved from inactive ifaces - create new
+  if (!ti)
+    vec_add2 (tm->tapcli_interfaces, ti, 1);
+
+  return ti;
+}
+
+/**
+ * @brief Connect a TAP interface
+ *
+ * @param vm - vlib_main_t
+ * @param intfc_name - u8
+ * @param hwaddr_arg - u8
+ * @param sw_if_indexp - u32
+ *
+ * @return rc - int
+ *
+ */
+int vnet_tap_connect (vlib_main_t * vm, u8 * intfc_name, u8 *hwaddr_arg,
+                      u32 * sw_if_indexp)
+{
+  tapcli_main_t * tm = &tapcli_main;
+  tapcli_interface_t * ti = NULL;
+  struct ifreq ifr;
+  int flags;
+  int dev_net_tun_fd;
+  int dev_tap_fd = -1;
+  clib_error_t * error;
+  u8 hwaddr [6];
+  int rv = 0;
+
+  if (tm->is_disabled)
+    {
+      return VNET_API_ERROR_FEATURE_DISABLED;
+    }
+
+  flags = IFF_TAP | IFF_NO_PI;
+
+  if ((dev_net_tun_fd = open ("/dev/net/tun", O_RDWR)) < 0)
+    return VNET_API_ERROR_SYSCALL_ERROR_1;
+
+  memset (&ifr, 0, sizeof (ifr));
+  strncpy(ifr.ifr_name, (char *) intfc_name, sizeof (ifr.ifr_name)-1);
+  ifr.ifr_flags = flags;
+  if (ioctl (dev_net_tun_fd, TUNSETIFF, (void *)&ifr) < 0)
+    {
+      rv = VNET_API_ERROR_SYSCALL_ERROR_2;
+      goto error;
+    }
+    
+  /* Open a provisioning socket */
+  if ((dev_tap_fd = socket(PF_PACKET, SOCK_RAW,
+                           htons(ETH_P_ALL))) < 0 )
+    {
+      rv = VNET_API_ERROR_SYSCALL_ERROR_3;
+      goto error;
+    }
+
+  /* Find the interface index. */
+  {
+    struct ifreq ifr;
+    struct sockaddr_ll sll;
+
+    memset (&ifr, 0, sizeof(ifr));
+    strncpy (ifr.ifr_name, (char *) intfc_name, sizeof (ifr.ifr_name)-1);
+    if (ioctl (dev_tap_fd, SIOCGIFINDEX, &ifr) < 0 )
+      {
+        rv = VNET_API_ERROR_SYSCALL_ERROR_4;
+        goto error;
+      }
+
+    /* 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(dev_tap_fd, (struct sockaddr*) &sll, sizeof(sll)) < 0)
+      {
+        rv = VNET_API_ERROR_SYSCALL_ERROR_5;
+        goto error;
+      }
+  }
+
+  /* non-blocking I/O on /dev/tapX */
+  {
+    int one = 1;
+    if (ioctl (dev_net_tun_fd, FIONBIO, &one) < 0)
+      {
+        rv = VNET_API_ERROR_SYSCALL_ERROR_6;
+	goto error;
+      }
+  }
+  ifr.ifr_mtu = tm->mtu_bytes;
+  if (ioctl (dev_tap_fd, SIOCSIFMTU, &ifr) < 0)
+    {
+      rv = VNET_API_ERROR_SYSCALL_ERROR_7;
+      goto error;
+    }
+
+  /* get flags, modify to bring up interface... */
+  if (ioctl (dev_tap_fd, SIOCGIFFLAGS, &ifr) < 0)
+    {
+      rv = VNET_API_ERROR_SYSCALL_ERROR_8;
+      goto error;
+    }
+
+  ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);
+
+  if (ioctl (dev_tap_fd, SIOCSIFFLAGS, &ifr) < 0)
+    {
+      rv = VNET_API_ERROR_SYSCALL_ERROR_9;
+      goto error;
+    }
+
+  ti = tapcli_get_new_tapif();
+  ti->per_interface_next_index = ~0;
+
+  if (hwaddr_arg != 0)
+    clib_memcpy(hwaddr, hwaddr_arg, 6);
+  else
+    {
+      f64 now = vlib_time_now(vm);
+      u32 rnd;
+      rnd = (u32) (now * 1e6);
+      rnd = random_u32 (&rnd);
+
+      memcpy (hwaddr+2, &rnd, sizeof(rnd));
+      hwaddr[0] = 2;
+      hwaddr[1] = 0xfe;
+    }
+
+  error = ethernet_register_interface
+        (tm->vnet_main,
+         tapcli_dev_class.index,
+         ti - tm->tapcli_interfaces /* device instance */,
+         hwaddr /* ethernet address */,
+         &ti->hw_if_index, 
+         tapcli_flag_change);
+
+  if (error)
+    {
+      clib_error_report (error);
+      rv = VNET_API_ERROR_INVALID_REGISTRATION;
+      goto error;
+    }
+
+  {
+    unix_file_t template = {0};
+    template.read_function = tapcli_read_ready;
+    template.file_descriptor = dev_net_tun_fd;
+    ti->unix_file_index = unix_file_add (&unix_main, &template);
+    ti->unix_fd = dev_net_tun_fd;
+    ti->provision_fd = dev_tap_fd;
+    clib_memcpy (&ti->ifr, &ifr, sizeof (ifr));
+  }
+  
+  {
+    vnet_hw_interface_t * hw;
+    hw = vnet_get_hw_interface (tm->vnet_main, ti->hw_if_index);
+    hw->min_supported_packet_bytes = TAP_MTU_MIN;
+    hw->max_supported_packet_bytes = TAP_MTU_MAX;
+    hw->max_l3_packet_bytes[VLIB_RX] = hw->max_l3_packet_bytes[VLIB_TX] = hw->max_supported_packet_bytes - sizeof(ethernet_header_t);
+    ti->sw_if_index = hw->sw_if_index;
+    if (sw_if_indexp)
+      *sw_if_indexp = hw->sw_if_index;
+  }
+
+  ti->active = 1;
+  
+  hash_set (tm->tapcli_interface_index_by_sw_if_index, ti->sw_if_index,
+            ti - tm->tapcli_interfaces);
+  
+  hash_set (tm->tapcli_interface_index_by_unix_fd, ti->unix_fd,
+            ti - tm->tapcli_interfaces);
+  
+  return rv;
+
+ error:
+  close (dev_net_tun_fd);
+  if (dev_tap_fd >= 0)
+      close (dev_tap_fd);
+
+  return rv;
+}
+
+/**
+ * @brief Renumber a TAP interface
+ *
+ * @param *vm - vlib_main_t
+ * @param *intfc_name - u8
+ * @param *hwaddr_arg - u8
+ * @param *sw_if_indexp - u32
+ * @param renumber - u8
+ * @param custom_dev_instance - u32
+ *
+ * @return rc - int
+ *
+ */
+int vnet_tap_connect_renumber (vlib_main_t * vm, u8 * intfc_name,
+                               u8 *hwaddr_arg, u32 * sw_if_indexp,
+                               u8 renumber, u32 custom_dev_instance)
+{
+    int rv = vnet_tap_connect(vm, intfc_name, hwaddr_arg, sw_if_indexp);
+
+    if (!rv && renumber)
+        vnet_interface_name_renumber (*sw_if_indexp, custom_dev_instance);
+
+    return rv;
+}
+
+/**
+ * @brief Disconnect TAP CLI interface
+ *
+ * @param *ti - tapcli_interface_t
+ *
+ * @return rc - int
+ *
+ */
+static int tapcli_tap_disconnect (tapcli_interface_t *ti)
+{
+  int rv = 0;
+  vnet_main_t * vnm = vnet_get_main();
+  tapcli_main_t * tm = &tapcli_main;
+  u32 sw_if_index = ti->sw_if_index;
+
+  // bring interface down
+  vnet_sw_interface_set_flags (vnm, sw_if_index, 0);
+
+  if (ti->unix_file_index != ~0) {
+    unix_file_del (&unix_main, unix_main.file_pool + ti->unix_file_index);
+    ti->unix_file_index = ~0;
+  }
+  else
+    close(ti->unix_fd);
+
+  hash_unset (tm->tapcli_interface_index_by_unix_fd, ti->unix_fd);
+  hash_unset (tm->tapcli_interface_index_by_sw_if_index, ti->sw_if_index);
+  close(ti->provision_fd);
+  ti->unix_fd = -1;
+  ti->provision_fd = -1;
+
+  return rv;
+}
+
+/**
+ * @brief Delete TAP interface
+ *
+ * @param *vm - vlib_main_t
+ * @param sw_if_index - u32
+ *
+ * @return rc - int
+ *
+ */
+int vnet_tap_delete(vlib_main_t *vm, u32 sw_if_index)
+{
+  int rv = 0;
+  tapcli_main_t * tm = &tapcli_main;
+  tapcli_interface_t *ti;
+  uword *p = NULL;
+
+  p = hash_get (tm->tapcli_interface_index_by_sw_if_index,
+                sw_if_index);
+  if (p == 0) {
+    clib_warning ("sw_if_index %d unknown", sw_if_index);
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+  }
+  ti = vec_elt_at_index (tm->tapcli_interfaces, p[0]);
+
+  // inactive
+  ti->active = 0;
+  tapcli_tap_disconnect(ti);
+  // add to inactive list
+  vec_add1(tm->tapcli_inactive_interfaces, ti - tm->tapcli_interfaces);
+
+  // reset renumbered iface
+  if (p[0] < vec_len (tm->show_dev_instance_by_real_dev_instance))
+    tm->show_dev_instance_by_real_dev_instance[p[0]] = ~0;
+
+  ethernet_delete_interface (tm->vnet_main, ti->hw_if_index);
+  return rv;
+}
+
+/**
+ * @brief CLI function to delete TAP interface
+ *
+ * @param *vm - vlib_main_t
+ * @param *input - unformat_input_t
+ * @param *cmd - vlib_cli_command_t
+ *
+ * @return error - clib_error_t
+ *
+ */
+static clib_error_t *
+tap_delete_command_fn (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+  tapcli_main_t * tm = &tapcli_main;
+  u32 sw_if_index = ~0;
+
+  if (tm->is_disabled)
+    {
+      return clib_error_return (0, "device disabled...");
+    }
+
+  if (unformat (input, "%U", unformat_vnet_sw_interface, tm->vnet_main,
+                &sw_if_index))
+      ;
+  else
+    return clib_error_return (0, "unknown input `%U'",
+                              format_unformat_error, input);
+
+
+  int rc = vnet_tap_delete (vm, sw_if_index);
+
+  if (!rc) {
+    vlib_cli_output (vm, "Deleted.");
+  } else {
+    vlib_cli_output (vm, "Error during deletion of tap interface. (rc: %d)", rc);
+  }
+
+  return 0;
+}
+
+VLIB_CLI_COMMAND (tap_delete_command, static) = {
+    .path = "tap delete",
+    .short_help = "tap delete <vpp-tap-intfc-name>",
+    .function = tap_delete_command_fn,
+};
+
+/**
+ * @brief Modifies tap interface - can result in new interface being created
+ *
+ * @param *vm - vlib_main_t
+ * @param orig_sw_if_index - u32
+ * @param *intfc_name - u8
+ * @param *hwaddr_arg - u8
+ * @param *sw_if_indexp - u32
+ * @param renumber - u8
+ * @param custom_dev_instance - u32
+ *
+ * @return rc - int
+ *
+ */
+int vnet_tap_modify (vlib_main_t * vm, u32 orig_sw_if_index,
+                     u8 * intfc_name, u8 *hwaddr_arg, 
+                     u32 * sw_if_indexp,
+                     u8 renumber, u32 custom_dev_instance)
+{
+    int rv = vnet_tap_delete (vm, orig_sw_if_index);
+
+    if (rv)
+        return rv;
+
+    rv = vnet_tap_connect_renumber(vm, intfc_name, hwaddr_arg, sw_if_indexp,
+            renumber, custom_dev_instance);
+
+    return rv;
+}
+
+/**
+ * @brief CLI function to modify TAP interface
+ *
+ * @param *vm - vlib_main_t
+ * @param *input - unformat_input_t
+ * @param *cmd - vlib_cli_command_t
+ *
+ * @return error - clib_error_t
+ *
+ */
+static clib_error_t *
+tap_modify_command_fn (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+  u8 * intfc_name;
+  tapcli_main_t * tm = &tapcli_main;
+  u32 sw_if_index = ~0;
+  u32 new_sw_if_index = ~0;
+  int user_hwaddr = 0;
+  u8 hwaddr[6];
+
+  if (tm->is_disabled)
+    {
+      return clib_error_return (0, "device disabled...");
+    }
+
+  if (unformat (input, "%U", unformat_vnet_sw_interface, tm->vnet_main,
+                &sw_if_index))
+      ;
+  else
+    return clib_error_return (0, "unknown input `%U'",
+                              format_unformat_error, input);
+
+  if (unformat (input, "%s", &intfc_name))
+    ;
+  else
+    return clib_error_return (0, "unknown input `%U'",
+                              format_unformat_error, input);
+
+  if (unformat(input, "hwaddr %U", unformat_ethernet_address,
+               &hwaddr))
+    user_hwaddr = 1;
+
+
+  int rc = vnet_tap_modify (vm, sw_if_index, intfc_name,
+                            (user_hwaddr == 1 ? hwaddr : 0),
+                            &new_sw_if_index, 0, 0);
+
+  if (!rc) {
+    vlib_cli_output (vm, "Modified %U for Linux tap '%s'",
+                   format_vnet_sw_if_index_name, tm->vnet_main, 
+                   new_sw_if_index, intfc_name);
+  } else {
+    vlib_cli_output (vm, "Error during modification of tap interface. (rc: %d)", rc);
+  }
+
+  return 0;
+}
+
+VLIB_CLI_COMMAND (tap_modify_command, static) = {
+    .path = "tap modify",
+    .short_help = "tap modify <vpp-tap-intfc-name> <linux-intfc-name> [hwaddr <addr>]",
+    .function = tap_modify_command_fn,
+};
+
+/**
+ * @brief CLI function to connect TAP interface
+ *
+ * @param *vm - vlib_main_t
+ * @param *input - unformat_input_t
+ * @param *cmd - vlib_cli_command_t
+ *
+ * @return error - clib_error_t
+ *
+ */
+static clib_error_t *
+tap_connect_command_fn (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+  u8 * intfc_name;
+  tapcli_main_t * tm = &tapcli_main;
+  u8 hwaddr[6];
+  u8 *hwaddr_arg = 0;
+  u32 sw_if_index;
+
+  if (tm->is_disabled)
+    {
+      return clib_error_return (0, "device disabled...");
+    }
+
+  if (unformat (input, "%s", &intfc_name))
+    ;
+  else
+    return clib_error_return (0, "unknown input `%U'",
+                              format_unformat_error, input);
+  
+  if (unformat(input, "hwaddr %U", unformat_ethernet_address,
+               &hwaddr))
+    hwaddr_arg = hwaddr;
+
+  /* It is here for backward compatibility */
+  if (unformat(input, "hwaddr random"))
+    ;
+
+  int rv = vnet_tap_connect(vm, intfc_name, hwaddr_arg, &sw_if_index);
+  if (rv) {
+    switch (rv) {
+    case VNET_API_ERROR_SYSCALL_ERROR_1:
+      vlib_cli_output (vm, "Couldn't open /dev/net/tun");
+      break;
+
+    case VNET_API_ERROR_SYSCALL_ERROR_2:
+      vlib_cli_output (vm, "Error setting flags on '%s'", intfc_name);
+      break;
+  
+    case VNET_API_ERROR_SYSCALL_ERROR_3:
+      vlib_cli_output (vm, "Couldn't open provisioning socket");
+      break;
+
+    case VNET_API_ERROR_SYSCALL_ERROR_4:
+      vlib_cli_output (vm, "Couldn't get if_index");
+      break;
+    
+    case VNET_API_ERROR_SYSCALL_ERROR_5:
+      vlib_cli_output (vm, "Couldn't bind provisioning socket");
+      break;
+
+    case VNET_API_ERROR_SYSCALL_ERROR_6:
+      vlib_cli_output (0, "Couldn't set device non-blocking flag");
+      break;
+
+    case VNET_API_ERROR_SYSCALL_ERROR_7:
+      vlib_cli_output (0, "Couldn't set device MTU");
+      break;
+
+    case VNET_API_ERROR_SYSCALL_ERROR_8:
+      vlib_cli_output (0, "Couldn't get interface flags");
+      break;
+
+    case VNET_API_ERROR_SYSCALL_ERROR_9:
+      vlib_cli_output (0, "Couldn't set intfc admin state up");
+      break;
+
+    case VNET_API_ERROR_INVALID_REGISTRATION:
+      vlib_cli_output (0, "Invalid registration");
+      break;
+    default:
+      vlib_cli_output (0, "Unknown error: %d", rv);
+      break;
+    }
+    return 0;
+  }
+
+  vlib_cli_output(vm, "%U\n", format_vnet_sw_if_index_name, vnet_get_main(), sw_if_index);
+  return 0;
+  }
+
+VLIB_CLI_COMMAND (tap_connect_command, static) = {
+    .path = "tap connect",
+    .short_help = "tap connect <intfc-name> [hwaddr <addr>]",
+    .function = tap_connect_command_fn,
+};
+
+/**
+ * @brief TAPCLI main init
+ *
+ * @param *vm - vlib_main_t
+ *
+ * @return error - clib_error_t
+ *
+ */
+clib_error_t *
+tapcli_init (vlib_main_t * vm)
+{
+  tapcli_main_t * tm = &tapcli_main;
+
+  tm->vlib_main = vm;
+  tm->vnet_main = vnet_get_main();
+  tm->unix_main = &unix_main;
+  tm->mtu_bytes = TAP_MTU_DEFAULT;
+  tm->tapcli_interface_index_by_sw_if_index = hash_create (0, sizeof(uword));
+  tm->tapcli_interface_index_by_unix_fd = hash_create (0, sizeof (uword));
+  tm->rx_buffers = 0;
+  vec_alloc(tm->rx_buffers, VLIB_FRAME_SIZE);
+  vec_reset_length(tm->rx_buffers);
+  vm->os_punt_frame = tapcli_nopunt_frame;
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (tapcli_init);