Implement DHCPv6 IA NA client (VPP-1094)

Change-Id: I682a47d6cf9975aca6136188d28ee93eaadf4fe3
Signed-off-by: Juraj Sloboda <jsloboda@cisco.com>

1 files changed, 831 insertions, 0 deletions

diff --git a/src/vnet/dhcp/dhcp6_ia_na_client_cp.c b/src/vnet/dhcp/dhcp6_ia_na_client_cp.c
new file mode 100644
index 00000000000..e83eecc17c3
--- /dev/null
+++ b/src/vnet/dhcp/dhcp6_ia_na_client_cp.c
@@ -0,0 +1,831 @@
+/*
+ * Copyright (c) 2018 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.
+ */
+
+#include <vnet/vnet.h>
+#include <vlibmemory/api.h>
+#include <vnet/vnet_msg_enum.h>
+#include <vnet/dhcp/dhcp6_packet.h>
+#include <vnet/dhcp/dhcp6_ia_na_client_dp.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ip/ip6.h>
+#include <float.h>
+#include <math.h>
+
+#define vl_typedefs		/* define message structures */
+#include <vnet/vnet_all_api_h.h>
+#undef vl_typedefs
+
+#define vl_endianfun		/* define message structures */
+#include <vnet/vnet_all_api_h.h>
+#undef vl_endianfun
+
+#include <vlibapi/api_helper_macros.h>
+
+#define foreach_dhcp6_client_cp_msg                                           \
+_(DHCP6_CLIENT_ENABLE_DISABLE, dhcp6_client_enable_disable)
+
+#define vl_api_dhcp6_client_enable_disable_t_print vl_noop_handler
+
+typedef struct
+{
+  u32 sw_if_index;
+  ip6_address_t address;
+  u32 preferred_lt;
+  u32 valid_lt;
+  f64 due_time;
+} address_info_t;
+
+typedef struct
+{
+  u8 enabled;
+  u32 server_index;
+  u32 T1;
+  u32 T2;
+  f64 T1_due_time;
+  f64 T2_due_time;
+  u32 address_count;
+  u8 rebinding;
+} client_state_t;
+
+typedef struct
+{
+  address_info_t *address_pool;
+  client_state_t *client_state_by_sw_if_index;
+  u32 n_clients;
+  f64 max_valid_due_time;
+
+  /* convenience */
+  vlib_main_t *vlib_main;
+  vnet_main_t *vnet_main;
+  api_main_t *api_main;
+  u32 node_index;
+} dhcp6_client_cp_main_t;
+
+static dhcp6_client_cp_main_t dhcp6_client_cp_main;
+
+enum
+{
+  RD_CP_EVENT_INTERRUPT,
+  RD_CP_EVENT_DISABLE,
+};
+
+static void
+send_client_message_start_stop (u32 sw_if_index, u32 server_index,
+				u8 msg_type, address_info_t * address_list,
+				u8 start)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  dhcp6_send_client_message_params_t params = { 0, };
+  dhcp6_send_client_message_params_address_t *addresses = 0, *addr;
+  u32 i;
+
+  ASSERT (sw_if_index < vec_len (rm->client_state_by_sw_if_index) &&
+	  rm->client_state_by_sw_if_index[sw_if_index].enabled);
+  client_state_t *client_state =
+    &rm->client_state_by_sw_if_index[sw_if_index];
+
+  params.sw_if_index = sw_if_index;
+  params.server_index = server_index;
+  params.msg_type = msg_type;
+  if (start)
+    {
+      if (msg_type == DHCPV6_MSG_SOLICIT)
+	{
+	  params.irt = 1;
+	  params.mrt = 120;
+	}
+      else if (msg_type == DHCPV6_MSG_REQUEST)
+	{
+	  params.irt = 1;
+	  params.mrt = 30;
+	  params.mrc = 10;
+	}
+      else if (msg_type == DHCPV6_MSG_RENEW)
+	{
+	  params.irt = 10;
+	  params.mrt = 600;
+	  f64 current_time = vlib_time_now (rm->vlib_main);
+	  i32 diff_time = client_state->T2 - current_time;
+	  if (diff_time < 0)
+	    diff_time = 0;
+	  params.mrd = diff_time;
+	}
+      else if (msg_type == DHCPV6_MSG_REBIND)
+	{
+	  params.irt = 10;
+	  params.mrt = 600;
+	  f64 current_time = vlib_time_now (rm->vlib_main);
+	  i32 diff_time = rm->max_valid_due_time - current_time;
+	  if (diff_time < 0)
+	    diff_time = 0;
+	  params.mrd = diff_time;
+	}
+      else if (msg_type == DHCPV6_MSG_RELEASE)
+	{
+	  params.mrc = 1;
+	}
+    }
+
+  params.T1 = 0;
+  params.T2 = 0;
+  if (vec_len (address_list) != 0)
+    vec_validate (addresses, vec_len (address_list) - 1);
+  for (i = 0; i < vec_len (address_list); i++)
+    {
+      address_info_t *address = &address_list[i];
+      addr = &addresses[i];
+      addr->valid_lt = address->valid_lt;
+      addr->preferred_lt = address->preferred_lt;
+      addr->address = address->address;
+    }
+  params.addresses = addresses;
+
+  dhcp6_send_client_message (rm->vlib_main, sw_if_index, !start, &params);
+
+  vec_free (params.addresses);
+}
+
+static void interrupt_process (void);
+
+static u32
+ip6_enable (u32 sw_if_index)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  clib_error_t *rv;
+
+  rv = enable_ip6_interface (rm->vlib_main, sw_if_index);
+
+  return rv != 0;
+}
+
+static u8
+ip6_addresses_equal (ip6_address_t * address1, ip6_address_t * address2)
+{
+  if (address1->as_u64[0] != address2->as_u64[0])
+    return 0;
+  return address1->as_u64[1] == address2->as_u64[1];
+}
+
+static clib_error_t *
+dhcp6_reply_event_handler (vl_api_dhcp6_reply_event_t * mp)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  vlib_main_t *vm = rm->vlib_main;
+  client_state_t *client_state;
+  ip6_address_t *address;
+  u32 sw_if_index;
+  u32 n_addresses;
+  vl_api_dhcp6_address_info_t *api_address;
+  u32 inner_status_code;
+  u32 status_code;
+  u32 server_index;
+  f64 current_time;
+  clib_error_t *error = 0;
+  u32 i;
+
+  current_time = vlib_time_now (vm);
+
+  sw_if_index = ntohl (mp->sw_if_index);
+
+  if (sw_if_index >= vec_len (rm->client_state_by_sw_if_index))
+    return 0;
+
+  client_state = &rm->client_state_by_sw_if_index[sw_if_index];
+
+  if (!client_state->enabled)
+    return 0;
+
+  server_index = ntohl (mp->server_index);
+
+  n_addresses = ntohl (mp->n_addresses);
+
+  inner_status_code = ntohs (mp->inner_status_code);
+  status_code = ntohs (mp->status_code);
+
+  if (mp->msg_type == DHCPV6_MSG_ADVERTISE
+      && client_state->server_index == ~0)
+    {
+      address_info_t *address_list = 0, *address_info;
+
+      if (inner_status_code == DHCPV6_STATUS_NOADDRS_AVAIL)
+	{
+	  clib_warning
+	    ("Advertise message arrived with NoAddrsAvail status code");
+	  return 0;
+	}
+
+      if (n_addresses > 0)
+	vec_validate (address_list, n_addresses - 1);
+      for (i = 0; i < n_addresses; i++)
+	{
+	  api_address = &mp->addresses[i];
+	  address = (ip6_address_t *) api_address->address;
+
+	  address_info = &address_list[i];
+	  address_info->address = *address;
+	  address_info->preferred_lt = 0;
+	  address_info->valid_lt = 0;
+	}
+
+      client_state->server_index = server_index;
+
+      send_client_message_start_stop (sw_if_index, server_index,
+				      DHCPV6_MSG_REQUEST, address_list, 1);
+      vec_free (address_list);
+    }
+
+  if (mp->msg_type != DHCPV6_MSG_REPLY)
+    return 0;
+
+  if (!client_state->rebinding && client_state->server_index != server_index)
+    {
+      clib_warning ("Reply message arrived with Server ID different "
+		    "from that in Request or Renew message");
+      return 0;
+    }
+
+  if (inner_status_code == DHCPV6_STATUS_NOADDRS_AVAIL)
+    {
+      clib_warning ("Reply message arrived with NoAddrsAvail status code");
+      if (n_addresses > 0)
+	{
+	  clib_warning
+	    ("Invalid Reply message arrived: It contains NoAddrsAvail "
+	     "status code but also contains addresses");
+	  return 0;
+	}
+    }
+
+  if (status_code == DHCPV6_STATUS_UNSPEC_FAIL)
+    {
+      clib_warning ("Reply message arrived with UnspecFail status code");
+      return 0;
+    }
+
+  send_client_message_start_stop (sw_if_index, server_index,
+				  mp->msg_type, 0, 0);
+
+  for (i = 0; i < n_addresses; i++)
+    {
+      address_info_t *address_info = 0;
+      u32 valid_time;
+      u32 preferred_time;
+
+      api_address = &mp->addresses[i];
+
+      address = (ip6_address_t *) api_address->address;
+
+      if (ip6_address_is_link_local_unicast (address))
+	continue;
+
+      valid_time = ntohl (api_address->valid_time);
+      preferred_time = ntohl (api_address->preferred_time);
+
+      if (preferred_time > valid_time)
+	continue;
+
+      u8 address_already_present = 0;
+      /* *INDENT-OFF* */
+      pool_foreach (address_info, rm->address_pool,
+      ({
+        if (address_info->sw_if_index != sw_if_index)
+          ;
+        else if (!ip6_addresses_equal (&address_info->address, address))
+          ;
+        else
+          {
+            address_already_present = 1;
+            goto address_pool_foreach_out;
+          }
+      }));
+      /* *INDENT-ON* */
+    address_pool_foreach_out:
+
+      if (address_already_present)
+	{
+	  address_info->preferred_lt = preferred_time;
+	  address_info->valid_lt = valid_time;
+	  address_info->due_time = current_time + valid_time;
+	  if (address_info->due_time > rm->max_valid_due_time)
+	    rm->max_valid_due_time = address_info->due_time;
+	  continue;
+	}
+
+      if (valid_time == 0)
+	continue;
+
+      pool_get (rm->address_pool, address_info);
+      address_info->sw_if_index = sw_if_index;
+      address_info->address = *address;
+      address_info->preferred_lt = preferred_time;
+      address_info->valid_lt = valid_time;
+      address_info->due_time = current_time + valid_time;
+      if (address_info->due_time > rm->max_valid_due_time)
+	rm->max_valid_due_time = address_info->due_time;
+      rm->client_state_by_sw_if_index[sw_if_index].address_count++;
+
+      error = ip6_add_del_interface_address (vm, sw_if_index,
+					     &address_info->address, 64, 0);
+      if (error)
+	clib_warning ("Failed to add interface address");
+    }
+
+  client_state->server_index = server_index;
+  client_state->T1 = ntohl (mp->T1);
+  client_state->T2 = ntohl (mp->T2);
+  if (client_state->T1 != 0)
+    client_state->T1_due_time = current_time + client_state->T1;
+  if (client_state->T2 != 0)
+    client_state->T2_due_time = current_time + client_state->T2;
+  client_state->rebinding = 0;
+
+  interrupt_process ();
+
+  return error;
+}
+
+static address_info_t *
+create_address_list (u32 sw_if_index)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  address_info_t *address_info, *address_list = 0;;
+
+  /* *INDENT-OFF* */
+  pool_foreach (address_info, rm->address_pool,
+  ({
+    if (address_info->sw_if_index == sw_if_index)
+      {
+        u32 pos = vec_len (address_list);
+        vec_validate (address_list, pos);
+        clib_memcpy (&address_list[pos], address_info, sizeof (*address_info));
+      }
+  }));
+  /* *INDENT-ON* */
+
+  return address_list;
+}
+
+VNET_DHCP6_REPLY_EVENT_FUNCTION (dhcp6_reply_event_handler);
+
+static uword
+dhcp6_client_cp_process (vlib_main_t * vm, vlib_node_runtime_t * rt,
+			 vlib_frame_t * f)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  address_info_t *address_info;
+  client_state_t *client_state;
+  f64 sleep_time = 1e9;
+  clib_error_t *error;
+  f64 current_time;
+  f64 due_time;
+  uword event_type;
+  uword *event_data = 0;
+  int i;
+
+  while (1)
+    {
+      vlib_process_wait_for_event_or_clock (vm, sleep_time);
+      event_type = vlib_process_get_events (vm, &event_data);
+      vec_reset_length (event_data);
+
+      if (event_type == RD_CP_EVENT_DISABLE)
+	{
+	  vlib_node_set_state (vm, rm->node_index, VLIB_NODE_STATE_DISABLED);
+	  sleep_time = 1e9;
+	  continue;
+	}
+
+      current_time = vlib_time_now (vm);
+      do
+	{
+	  due_time = current_time + 1e9;
+          /* *INDENT-OFF* */
+          pool_foreach (address_info, rm->address_pool,
+          ({
+            if (address_info->due_time > current_time)
+              {
+                if (address_info->due_time < due_time)
+                  due_time = address_info->due_time;
+              }
+            else
+              {
+                u32 sw_if_index = address_info->sw_if_index;
+                error = ip6_add_del_interface_address (vm, sw_if_index,
+                                                       &address_info->address,
+                                                       64, 1);
+                if (error)
+                    clib_warning ("Failed to delete interface address");
+                pool_put (rm->address_pool, address_info);
+                /* make sure ip6 stays enabled */
+                ip6_enable (sw_if_index);
+                client_state = &rm->client_state_by_sw_if_index[sw_if_index];
+                if (--client_state->address_count == 0)
+                  {
+                    client_state->rebinding = 0;
+                    client_state->server_index = ~0;
+                    send_client_message_start_stop (sw_if_index, ~0,
+                                                    DHCPV6_MSG_SOLICIT,
+                                                    0, 1);
+                  }
+              }
+          }));
+          /* *INDENT-ON* */
+	  for (i = 0; i < vec_len (rm->client_state_by_sw_if_index); i++)
+	    {
+	      client_state_t *cs = &rm->client_state_by_sw_if_index[i];
+	      if (cs->enabled && cs->server_index != ~0)
+		{
+		  if (cs->T2_due_time > current_time)
+		    {
+		      if (cs->T2_due_time < due_time)
+			due_time = cs->T2_due_time;
+		      if (cs->T1_due_time > current_time)
+			{
+			  if (cs->T1_due_time < due_time)
+			    due_time = cs->T1_due_time;
+			}
+		      else
+			{
+			  cs->T1_due_time = DBL_MAX;
+			  address_info_t *address_list;
+			  address_list = create_address_list (i);
+			  cs->rebinding = 1;
+			  send_client_message_start_stop (i, cs->server_index,
+							  DHCPV6_MSG_RENEW,
+							  address_list, 1);
+			  vec_free (address_list);
+			}
+		    }
+		  else
+		    {
+		      cs->T2_due_time = DBL_MAX;
+		      address_info_t *address_list;
+		      address_list = create_address_list (i);
+		      cs->rebinding = 1;
+		      send_client_message_start_stop (i, ~0,
+						      DHCPV6_MSG_REBIND,
+						      address_list, 1);
+		      vec_free (address_list);
+		    }
+		}
+	    }
+	  current_time = vlib_time_now (vm);
+	}
+      while (due_time < current_time);
+
+      sleep_time = due_time - current_time;
+    }
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (dhcp6_client_cp_process_node) = {
+    .function = dhcp6_client_cp_process,
+    .type = VLIB_NODE_TYPE_PROCESS,
+    .name = "dhcp6-client-cp-process",
+};
+/* *INDENT-ON* */
+
+static void
+interrupt_process (void)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  vlib_main_t *vm = rm->vlib_main;
+
+  vlib_process_signal_event (vm, dhcp6_client_cp_process_node.index,
+			     RD_CP_EVENT_INTERRUPT, 0);
+}
+
+static void
+disable_process (void)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  vlib_main_t *vm = rm->vlib_main;
+
+  vlib_process_signal_event (vm, dhcp6_client_cp_process_node.index,
+			     RD_CP_EVENT_DISABLE, 0);
+}
+
+static void
+enable_process (void)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  vlib_main_t *vm = rm->vlib_main;
+  vlib_node_t *node;
+
+  node = vec_elt (vm->node_main.nodes, rm->node_index);
+
+  vlib_node_set_state (vm, rm->node_index, VLIB_NODE_STATE_POLLING);
+  vlib_start_process (vm, node->runtime_index);
+}
+
+static clib_error_t *
+dhcp6_addresses_show_command_function (vlib_main_t * vm,
+				       unformat_input_t * input,
+				       vlib_cli_command_t * cmd)
+{
+  dhcp6_client_cp_main_t *dm = &dhcp6_client_cp_main;
+  clib_error_t *error = 0;
+  address_info_t *address_info;
+  f64 current_time = vlib_time_now (vm);
+
+  /* *INDENT-OFF* */
+  pool_foreach (address_info, dm->address_pool,
+  ({
+    vlib_cli_output (vm, "address: %U, "
+                     "preferred lifetime: %u, valid lifetime: %u "
+                     "(%f remaining)",
+                     format_ip6_address, &address_info->address,
+                     address_info->preferred_lt, address_info->valid_lt,
+                     address_info->due_time - current_time);
+  }));
+  /* *INDENT-ON* */
+
+  return error;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (dhcp6_addresses_show_command, static) = {
+  .path = "show dhcp6 addresses",
+  .short_help = "show dhcp6 addresses",
+  .function = dhcp6_addresses_show_command_function,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+dhcp6_clients_show_command_function (vlib_main_t * vm,
+				     unformat_input_t * input,
+				     vlib_cli_command_t * cmd)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  clib_error_t *error = 0;
+  client_state_t *cs;
+  f64 current_time = vlib_time_now (vm);
+  char buf1[256];
+  char buf2[256];
+  const char *rebinding;
+  u32 i;
+
+  for (i = 0; i < vec_len (rm->client_state_by_sw_if_index); i++)
+    {
+      cs = &rm->client_state_by_sw_if_index[i];
+      if (cs->enabled)
+	{
+	  if (cs->T1_due_time != DBL_MAX && cs->T1_due_time > current_time)
+	    {
+	      sprintf (buf1, "%u remaining",
+		       (u32) round (cs->T1_due_time - current_time));
+	    }
+	  else
+	    sprintf (buf1, "timeout");
+	  if (cs->T2_due_time != DBL_MAX && cs->T2_due_time > current_time)
+	    sprintf (buf2, "%u remaining",
+		     (u32) round (cs->T2_due_time - current_time));
+	  else
+	    sprintf (buf2, "timeout");
+	  if (cs->rebinding)
+	    rebinding = ", REBINDING";
+	  else
+	    rebinding = "";
+	  if (cs->T1)
+	    vlib_cli_output (vm,
+			     "sw_if_index: %u, T1: %u (%s), "
+			     "T2: %u (%s), server index: %d%s", i,
+			     cs->T1, buf1, cs->T2, buf2,
+			     cs->server_index, rebinding);
+	  else
+	    vlib_cli_output (vm, "sw_if_index: %u%s", i, rebinding);
+	}
+    }
+
+  return error;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (dhcp6_clients_show_command, static) = {
+  .path = "show dhcp6 clients",
+  .short_help = "show dhcp6 clients",
+  .function = dhcp6_clients_show_command_function,
+};
+/* *INDENT-ON* */
+
+static int
+dhcp6_client_enable_disable (u32 sw_if_index, u8 enable)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  vnet_main_t *vnm = rm->vnet_main;
+  vlib_main_t *vm = rm->vlib_main;
+  client_state_t *client_state;
+  client_state_t empty_config = { 0 };
+  address_info_t *address_info;
+  clib_error_t *error;
+
+  if (!vnet_sw_interface_is_api_valid (vnm, sw_if_index))
+    {
+      clib_warning ("Invalid sw_if_index");
+      return 1;
+    }
+
+  vec_validate_init_empty (rm->client_state_by_sw_if_index, sw_if_index,
+			   empty_config);
+  client_state = &rm->client_state_by_sw_if_index[sw_if_index];
+
+  u8 old_enabled = client_state->enabled;
+  if (enable)
+    client_state->enabled = 1;
+  client_state->server_index = ~0;
+
+  if (!old_enabled && enable)
+    {
+      rm->n_clients++;
+      if (rm->n_clients == 1)
+	{
+	  enable_process ();
+	  dhcp6_clients_enable_disable (1);
+	}
+
+      ip6_enable (sw_if_index);
+      send_client_message_start_stop (sw_if_index, ~0, DHCPV6_MSG_SOLICIT,
+				      0, 1);
+    }
+  else if (old_enabled && !enable)
+    {
+      send_client_message_start_stop (sw_if_index, ~0, ~0, 0, 0);
+
+      rm->n_clients--;
+      if (rm->n_clients == 0)
+	{
+	  dhcp6_clients_enable_disable (0);
+	  disable_process ();
+	}
+
+      /* *INDENT-OFF* */
+      pool_foreach (address_info, rm->address_pool,
+      ({
+        if (address_info->sw_if_index == sw_if_index)
+          {
+            ASSERT (sw_if_index < vec_len (rm->client_state_by_sw_if_index) &&
+                    rm->client_state_by_sw_if_index[sw_if_index].enabled);
+            client_state_t *client_state =
+              &rm->client_state_by_sw_if_index[sw_if_index];
+            send_client_message_start_stop (sw_if_index,
+                                            client_state->server_index,
+                                            DHCPV6_MSG_RELEASE, address_info,
+                                            1);
+            error = ip6_add_del_interface_address (vm, sw_if_index,
+                                                   &address_info->address,
+                                                   64, 1);
+            if (error)
+                clib_warning ("Failed to delete interface address");
+            pool_put (rm->address_pool, address_info);
+          }
+      }));
+      /* *INDENT-ON* */
+    }
+
+  if (!enable)
+    client_state->enabled = 0;
+
+  return 0;
+}
+
+static clib_error_t *
+dhcp6_client_enable_disable_command_fn (vlib_main_t * vm,
+					unformat_input_t * input,
+					vlib_cli_command_t * cmd)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  vnet_main_t *vnm = rm->vnet_main;
+  clib_error_t *error = 0;
+  u32 sw_if_index = ~0;
+  u8 enable = 1;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat
+	  (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
+	;
+      else if (unformat (input, "disable"))
+	enable = 0;
+      else
+	{
+	  error = clib_error_return (0, "unexpected input `%U'",
+				     format_unformat_error, input);
+	  goto done;
+	}
+    }
+
+  if (sw_if_index != ~0)
+    {
+      if (dhcp6_client_enable_disable (sw_if_index, enable) != 0)
+	error = clib_error_return (0, "Invalid sw_if_index");
+    }
+  else
+    error = clib_error_return (0, "Missing sw_if_index");
+
+done:
+  return error;
+}
+
+/*?
+ * This command is used to enable/disable DHCPv6 client
+ * on particular interface.
+ *
+ * @cliexpar
+ * @parblock
+ * Example of how to enable DHCPv6 client:
+ * @cliexcmd{dhcp6 client GigabitEthernet2/0/0}
+ * Example of how to disable DHCPv6 client:
+ * @cliexcmd{dhcp6 client GigabitEthernet2/0/0 disable}
+ * @endparblock
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (dhcp6_client_enable_disable_command, static) = {
+  .path = "dhcp6 client",
+  .short_help = "dhcp6 client <interface> [disable]",
+  .function = dhcp6_client_enable_disable_command_fn,
+};
+/* *INDENT-ON* */
+
+static void
+  vl_api_dhcp6_client_enable_disable_t_handler
+  (vl_api_dhcp6_client_enable_disable_t * mp)
+{
+  vl_api_dhcp6_client_enable_disable_reply_t *rmp;
+  u32 sw_if_index;
+  int rv = 0;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  sw_if_index = ntohl (mp->sw_if_index);
+
+  rv = dhcp6_client_enable_disable (sw_if_index, mp->enable);
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_SW_INTERFACE_SET_TABLE_REPLY);
+}
+
+#define vl_msg_name_crc_list
+#include <vnet/dhcp/dhcp6_ia_na_client_cp.api.h>
+#undef vl_msg_name_crc_list
+
+static void
+setup_message_id_table (api_main_t * am)
+{
+#define _(id,n,crc) vl_msg_api_add_msg_name_crc (am, #n "_" #crc, id);
+  foreach_vl_msg_name_crc_dhcp6_ia_na_client_cp;
+#undef _
+}
+
+static clib_error_t *
+dhcp_client_cp_init (vlib_main_t * vm)
+{
+  dhcp6_client_cp_main_t *rm = &dhcp6_client_cp_main;
+  api_main_t *am = &api_main;
+
+  rm->vlib_main = vm;
+  rm->vnet_main = vnet_get_main ();
+  rm->api_main = am;
+  rm->node_index = dhcp6_client_cp_process_node.index;
+
+#define _(N,n)                                                  \
+    vl_msg_api_set_handlers(VL_API_##N, #n,                     \
+                           vl_api_##n##_t_handler,              \
+                           vl_noop_handler,                     \
+                           vl_api_##n##_t_endian,               \
+                           vl_api_##n##_t_print,                \
+                           sizeof(vl_api_##n##_t), 0/* do NOT trace! */);
+  foreach_dhcp6_client_cp_msg;
+#undef _
+
+  /*
+   * Set up the (msg_name, crc, message-id) table
+   */
+  setup_message_id_table (am);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (dhcp_client_cp_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */