Networking: Clean up IPv6 Neighbor Table logic

10 files changed, 714 insertions, 210 deletions

diff --git a/nuttx/net/neighbor/Kconfig b/nuttx/net/neighbor/Kconfig
index 148438fbe..88cea4a1a 100644
--- a/nuttx/net/neighbor/Kconfig
+++ b/nuttx/net/neighbor/Kconfig
@@ -5,10 +5,10 @@
 
 if NET_IPv6
 
-config NET_IPV6_NCONF_ENTRIES
+config NET_IPv6_NCONF_ENTRIES
 	int "Number of IPv6 neighbors"
 	default 8
 
-#config NET_IPV6_NEIGHBOR_ADDRTYPE
+#config NET_IPv6_NEIGHBOR_ADDRTYPE
 
 endif # NET_IPv6
diff --git a/nuttx/net/neighbor/Make.defs b/nuttx/net/neighbor/Make.defs
index ee77ad29d..19cbb13e1 100644
--- a/nuttx/net/neighbor/Make.defs
+++ b/nuttx/net/neighbor/Make.defs
@@ -37,7 +37,8 @@
 
 ifeq ($(CONFIG_NET_IPv6),y)
 
-NET_CSRCS += neighbor.c
+NET_CSRCS += neighbor_initialize.c neighbor_add.c neighbor_lookup.c
+NET_CSRCS += neighbor_update.c neighbor_periodic.c neighbor_findentry.c
 
 # Include utility build support
 
diff --git a/nuttx/net/neighbor/neighbor.c b/nuttx/net/neighbor/neighbor.c
deleted file mode 100644
index 37a2460a1..000000000
--- a/nuttx/net/neighbor/neighbor.c
+++ /dev/null
@@ -1,196 +0,0 @@
-/****************************************************************************
- * net/neighbor/neighbor.c
- * Database of link-local neighbors, used by IPv6 code and to be used by
- * a future ARP code rewrite.
- *
- *   Copyright (c) 2006, Swedish Institute of Computer Science.  All rights
- *     reserved.
- *   Author: Adam Dunkels <adam@sics.se>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the Institute nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- ****************************************************************************/
-
-/****************************************************************************
- * Included Files
- ****************************************************************************/
-
-#include <nuttx/config.h>
-
-#include <string.h>
-#include <debug.h>
-
-#include <nuttx/net/ip.h>
-
-#include "neighbor/neighbor.h"
-
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-
-#define MAX_TIME 128
-
-#ifdef CONFIG_NET_IPV6_NCONF_ENTRIES
-#  define ENTRIES CONFIG_NET_IPV6_NCONF_ENTRIES
-#else /* CONFIG_NET_IPV6_NCONF_ENTRIES */
-#  define ENTRIES 8
-#endif /* CONFIG_NET_IPV6_NCONF_ENTRIES */
-
-/****************************************************************************
- * Private Types
- ****************************************************************************/
-
-struct neighbor_entry
-{
-  net_ipv6addr_t ipaddr;
-  struct net_neighbor_addr_s addr;
-  uint8_t time;
-};
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
-static struct neighbor_entry entries[ENTRIES];
-
-/****************************************************************************
- * Private Functions
- ****************************************************************************/
-
-static struct neighbor_entry *find_entry(net_ipv6addr_t ipaddr)
-{
-  int i;
-
-  for (i = 0; i < ENTRIES; ++i)
-    {
-      if (net_ipv6addr_cmp(entries[i].ipaddr, ipaddr))
-        {
-          return &entries[i];
-        }
-    }
-
-  return NULL;
-}
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
-void net_neighbor_init(void)
-{
-  int i;
-
-  for (i = 0; i < ENTRIES; ++i)
-    {
-      entries[i].time = MAX_TIME;
-    }
-}
-
-void net_neighbor_periodic(void)
-{
-  int i;
-
-  for (i = 0; i < ENTRIES; ++i)
-    {
-      if (entries[i].time < MAX_TIME)
-        {
-        entries[i].time++;
-        }
-    }
-}
-
-void net_neighbor_add(net_ipv6addr_t ipaddr, struct net_neighbor_addr_s *addr)
-{
-  uint8_t oldest_time;
-  int     oldest;
-  int     i;
-
-  nlldbg("Add neighbor: %02x:%02x:%02x:%02x:%02x:%02x\n",
-         addr->addr.ether_addr_octet[0], addr->addr.ether_addr_octet[1],
-         addr->addr.ether_addr_octet[2], addr->addr.ether_addr_octet[3],
-         addr->addr.ether_addr_octet[4], addr->addr.ether_addr_octet[5]);
-
-  /* Find the first unused entry or the oldest used entry. */
-
-  oldest_time = 0;
-  oldest = 0;
-
-  for (i = 0; i < ENTRIES; ++i)
-    {
-      if (entries[i].time == MAX_TIME)
-        {
-          oldest = i;
-          break;
-        }
-      if (net_ipv6addr_cmp(entries[i].ipaddr, addr))
-        {
-          oldest = i;
-          break;
-        }
-      if (entries[i].time > oldest_time)
-        {
-          oldest = i;
-          oldest_time = entries[i].time;
-        }
-    }
-
-  /* Use the oldest or first free entry (either pointed to by the
-   * "oldest" variable).
-   */
-
-  entries[oldest].time = 0;
-  net_ipv6addr_copy(entries[oldest].ipaddr, ipaddr);
-  memcpy(&entries[oldest].addr, addr, sizeof(struct net_neighbor_addr_s));
-}
-
-void net_neighbor_update(net_ipv6addr_t ipaddr)
-{
-  struct neighbor_entry *e;
-
-  e = find_entry(ipaddr);
-  if (e != NULL)
-    {
-      e->time = 0;
-    }
-}
-
-struct net_neighbor_addr_s *net_neighbor_lookup(net_ipv6addr_t ipaddr)
-{
-  struct neighbor_entry *e;
-
-  e = find_entry(ipaddr);
-  if (e != NULL)
-    {
-      nlldbg("Lookup neighbor: %02x:%02x:%02x:%02x:%02x:%02x\n",
-             e->addr.addr.ether_addr_octet[0], e->addr.addr.ether_addr_octet[1],
-             e->addr.addr.ether_addr_octet[2], e->addr.addr.ether_addr_octet[3],
-             e->addr.addr.ether_addr_octet[4], e->addr.addr.ether_addr_octet[5]);
-
-      return &e->addr;
-    }
-
-  return NULL;
-}
diff --git a/nuttx/net/neighbor/neighbor.h b/nuttx/net/neighbor/neighbor.h
index db43fecfa..ffc003827 100644
--- a/nuttx/net/neighbor/neighbor.h
+++ b/nuttx/net/neighbor/neighbor.h
@@ -3,10 +3,10 @@
  * Header file for database of link-local neighbors, used by IPv6 code and
  * to be used by future ARP code.
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
- * A direct leverage of logic from uIP which also has b BSD style license
+ * A leverage of logic from uIP which also has a BSD style license
  *
  *   Author: Adam Dunkels <adam@sics.se>
  *   Copyright (c) 2006, Swedish Institute of Computer Science.
@@ -54,31 +54,162 @@
 #ifdef CONFIG_NET_IPv6
 
 /****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef CONFIG_NET_IPv6_NCONF_ENTRIES
+#  define CONFIG_NET_IPv6_NCONF_ENTRIES 8
+#endif
+
+#define NEIGHBOR_MAXTIME 128
+
+/****************************************************************************
  * Public Types
  ****************************************************************************/
+/* Describes the link layer address */
 
-struct net_neighbor_addr_s
+struct neighbor_addr_s
 {
-#if CONFIG_NET_IPV6_NEIGHBOR_ADDRTYPE
-  CONFIG_NET_IPV6_NEIGHBOR_ADDRTYPE addr;
+#if CONFIG_NET_IPv6_NEIGHBOR_ADDRTYPE
+  CONFIG_NET_IPv6_NEIGHBOR_ADDRTYPE na_addr;
 #else
-  struct ether_addr addr;
+  struct ether_addr na_addr;
 #endif
 };
 
+/* This structure describes on entry in the neighbor table.  This is intended
+ * for internal use within the Neighbor implementation.
+ */
+
+struct neighbor_entry
+{
+  net_ipv6addr_t         ne_ipaddr;  /* IPv6 address of the Neighbor */
+  struct neighbor_addr_s ne_addr;    /* Link layer address of the Neighbor */
+  uint8_t                ne_time;    /* For aging, units of half seconds */
+};
+
 /****************************************************************************
  * Public Data
  ****************************************************************************/
 
+/* This is the Neighbor table.  The network should be locked when accessing
+ * this table.
+ */
+
+extern struct neighbor_entry g_neighbors[CONFIG_NET_IPv6_NCONF_ENTRIES];
+
+/* This is the time, in clock ticks, of the last poll */
+
+extern uint32_t g_neighbor_polltime;
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
 
-void net_neighbor_init(void);
-void net_neighbor_add(net_ipv6addr_t ipaddr, struct net_neighbor_addr_s *addr);
-void net_neighbor_update(net_ipv6addr_t ipaddr);
-struct net_neighbor_addr_s *net_neighbor_lookup(net_ipv6addr_t ipaddr);
-void net_neighbor_periodic(void);
+/****************************************************************************
+ * Name: neighbor_initialize
+ *
+ * Description:
+ *  Initialize Neighbor table support
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_initialize(void);
+
+/****************************************************************************
+ * Name: neighbor_findentry
+ *
+ * Description:
+ *   Find an entry in the Neighbor Table.  This interface is internal to
+ *   the neighbor implementation; Consider using neighbor_lookup() instead;
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address to use in the lookup;
+ *
+ * Returned Value:
+ *   The Neighbor Table entry corresponding to the IPv6 address;  NULL is
+ *   returned if there is no matching entry in the Neighbor Table.
+ *
+ ****************************************************************************/
+
+FAR struct neighbor_entry *neighbor_findentry(net_ipv6addr_t ipaddr);
+
+/****************************************************************************
+ * Name: neighbor_add
+ *
+ * Description:
+ *   Add the new address association to the Neighbor Table (if it is not
+ *   already there).
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address of the mapping.
+ *   addr   - The link layer address of the mapping
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_add(FAR net_ipv6addr_t ipaddr, FAR struct neighbor_addr_s *addr);
+
+/****************************************************************************
+ * Name:  neighbor_lookup
+ *
+ * Description:
+ *   Find an entry in the Neighbor Table and return its link layer address.
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address to use in the lookup;
+ *
+ * Returned Value:
+ *   A read-only reference to the link layer address in the Neighbor Table is
+ *   returned on success.  NULL is returned if there is no matching entry in
+ *   the Neighbor Table.
+ *
+ ****************************************************************************/
+
+FAR const struct neighbor_addr_s *neighbor_lookup(net_ipv6addr_t ipaddr);
+
+/****************************************************************************
+ * Name: neighbor_update
+ *
+ * Description:
+ *   Reset time on the Neighbor Table entry associated with the IPv6 address.
+ *   This makes the associated entry the most recently used and not a
+ *   candidate for removal.
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address of the entry to be updated
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_update(net_ipv6addr_t ipaddr);
+
+/****************************************************************************
+ * Name: neighbor_periodic
+ *
+ * Description:
+ *   Called from the timer poll logic in order to perform agin operations on
+ *   entries in the Neighbor Table
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_periodic(void);
 
 #endif /* CONFIG_NET_IPv6 */
 #endif /* __NET_NEIGHBOR_NEIGHBOR_H */
diff --git a/nuttx/net/neighbor/neighbor_add.c b/nuttx/net/neighbor/neighbor_add.c
new file mode 100644
index 000000000..02cf8f6f9
--- /dev/null
+++ b/nuttx/net/neighbor/neighbor_add.c
@@ -0,0 +1,117 @@
+/****************************************************************************
+ * net/neighbor/neighbor_add.c
+ *
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * A leverage of logic from uIP which also has a BSD style license
+ *
+ *   Copyright (c) 2006, Swedish Institute of Computer Science.  All rights
+ *     reserved.
+ *   Author: Adam Dunkels <adam@sics.se>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+#include <debug.h>
+
+#include <nuttx/net/ip.h>
+
+#include "neighbor/neighbor.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: neighbor_add
+ *
+ * Description:
+ *   Add the new address association to the Neighbor Table (if it is not
+ *   already there).
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address of the mapping.
+ *   addr   - The link layer address of the mapping
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_add(FAR net_ipv6addr_t ipaddr, FAR struct neighbor_addr_s *addr)
+{
+  uint8_t oldest_time;
+  int     oldest_ndx;
+  int     i;
+
+  nlldbg("Add neighbor: %02x:%02x:%02x:%02x:%02x:%02x\n",
+         addr->na_addr.ether_addr_octet[0], addr->na_addr.ether_addr_octet[1],
+         addr->na_addr.ether_addr_octet[2], addr->na_addr.ether_addr_octet[3],
+         addr->na_addr.ether_addr_octet[4], addr->na_addr.ether_addr_octet[5]);
+
+  /* Find the first unused entry or the oldest used entry. */
+
+  oldest_time = 0;
+  oldest_ndx  = 0;
+
+  for (i = 0; i < CONFIG_NET_IPv6_NCONF_ENTRIES; ++i)
+    {
+      if (g_neighbors[i].ne_time == NEIGHBOR_MAXTIME)
+        {
+          oldest_ndx = i;
+          break;
+        }
+
+      if (net_ipv6addr_cmp(g_neighbors[i].ne_ipaddr, addr))
+        {
+          oldest_ndx = i;
+          break;
+        }
+
+      if (g_neighbors[i].ne_time > oldest_time)
+        {
+          oldest_ndx = i;
+          oldest_time = g_neighbors[i].ne_time;
+        }
+    }
+
+  /* Use the oldest or first free entry (either pointed to by the
+   * "oldest_ndx" variable).
+   */
+
+  g_neighbors[oldest_ndx].ne_time = 0;
+  net_ipv6addr_copy(g_neighbors[oldest_ndx].ne_ipaddr, ipaddr);
+  memcpy(&g_neighbors[oldest_ndx].ne_addr, addr, sizeof(struct neighbor_addr_s));
+}
diff --git a/nuttx/net/neighbor/neighbor_findentry.c b/nuttx/net/neighbor/neighbor_findentry.c
new file mode 100644
index 000000000..30b13038c
--- /dev/null
+++ b/nuttx/net/neighbor/neighbor_findentry.c
@@ -0,0 +1,83 @@
+/****************************************************************************
+ * net/neighbor/neighbor_findentry.c
+ *
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * A leverage of logic from uIP which also has a BSD style license
+ *
+ *   Copyright (c) 2006, Swedish Institute of Computer Science.  All rights
+ *     reserved.
+ *   Author: Adam Dunkels <adam@sics.se>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+
+#include "neighbor/neighbor.h"
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: neighbor_findentry
+ *
+ * Description:
+ *   Find an entry in the Neighbor Table.  This interface is internal to
+ *   the neighbor implementation; Consider using neighbor_lookup() instead;
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address to use in the lookup;
+ *
+ * Returned Value:
+ *   The Neighbor Table entry corresponding to the IPv6 address;  NULL is
+ *   returned if there is no matching entry in the Neighbor Table.
+ *
+ ****************************************************************************/
+
+FAR struct neighbor_entry *neighbor_findentry(net_ipv6addr_t ipaddr)
+{
+  int i;
+
+  for (i = 0; i < CONFIG_NET_IPv6_NCONF_ENTRIES; ++i)
+    {
+      if (net_ipv6addr_cmp(g_neighbors[i].ne_ipaddr, ipaddr))
+        {
+          return &g_neighbors[i];
+        }
+    }
+
+  return NULL;
+}
diff --git a/nuttx/net/neighbor/neighbor_initialize.c b/nuttx/net/neighbor/neighbor_initialize.c
new file mode 100644
index 000000000..fd8b36d36
--- /dev/null
+++ b/nuttx/net/neighbor/neighbor_initialize.c
@@ -0,0 +1,93 @@
+/****************************************************************************
+ * net/neighbor/neighbor_initialize.c
+ *
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * A leverage of logic from uIP which also has a BSD style license
+ *
+ *   Copyright (c) 2006, Swedish Institute of Computer Science.  All rights
+ *     reserved.
+ *   Author: Adam Dunkels <adam@sics.se>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/clock.h>
+
+#include "neighbor/neighbor.h"
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* This is the Neighbor table.  The network should be locked when accessing
+ * this table.
+ */
+
+struct neighbor_entry g_neighbors[CONFIG_NET_IPv6_NCONF_ENTRIES];
+
+/* This is the time, in clock ticks, of the last poll */
+
+uint32_t g_neighbor_polltime;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: neighbor_initialize
+ *
+ * Description:
+ *  Initialize Neighbor table support
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_initialize(void)
+{
+  int i;
+
+  for (i = 0; i < CONFIG_NET_IPv6_NCONF_ENTRIES; ++i)
+    {
+      g_neighbors[i].ne_time = NEIGHBOR_MAXTIME;
+    }
+
+  /* Initialize the time of the last poll */
+
+   g_neighbor_polltime = clock_systimer();
+}
diff --git a/nuttx/net/neighbor/neighbor_lookup.c b/nuttx/net/neighbor/neighbor_lookup.c
new file mode 100644
index 000000000..4c7d9b04a
--- /dev/null
+++ b/nuttx/net/neighbor/neighbor_lookup.c
@@ -0,0 +1,91 @@
+/****************************************************************************
+ * net/neighbor/neighbor.c
+ *
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * A leverage of logic from uIP which also has a BSD style license
+ *
+ *   Copyright (c) 2006, Swedish Institute of Computer Science.  All rights
+ *     reserved.
+ *   Author: Adam Dunkels <adam@sics.se>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+
+#include <nuttx/net/ip.h>
+
+#include "neighbor/neighbor.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name:  neighbor_lookup
+ *
+ * Description:
+ *   Find an entry in the Neighbor Table and return its link layer address.
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address to use in the lookup;
+ *
+ * Returned Value:
+ *   A read-only reference to the link layer address in the Neighbor Table is
+ *   returned on success.  NULL is returned if there is no matching entry in
+ *   the Neighbor Table.
+ *
+ ****************************************************************************/
+
+FAR const struct neighbor_addr_s *neighbor_lookup(net_ipv6addr_t ipaddr)
+{
+  FAR struct neighbor_entry *neighbor;
+
+  neighbor = neighbor_findentry(ipaddr);
+  if (neighbor != NULL)
+    {
+      nlldbg("Lookup neighbor: %02x:%02x:%02x:%02x:%02x:%02x\n",
+             neighbor->ne_addr.na_addr.ether_addr_octet[0],
+             neighbor->ne_addr.na_addr.ether_addr_octet[1],
+             neighbor->ne_addr.na_addr.ether_addr_octet[2],
+             neighbor->ne_addr.na_addr.ether_addr_octet[3],
+             neighbor->ne_addr.na_addr.ether_addr_octet[4],
+             neighbor->ne_addr.na_addr.ether_addr_octet[5]);
+
+      return &neighbor->ne_addr;
+    }
+
+  return NULL;
+}
diff --git a/nuttx/net/neighbor/neighbor_periodic.c b/nuttx/net/neighbor/neighbor_periodic.c
new file mode 100644
index 000000000..2a9f0d99f
--- /dev/null
+++ b/nuttx/net/neighbor/neighbor_periodic.c
@@ -0,0 +1,107 @@
+/****************************************************************************
+ * net/neighbor/neighbor_periodic.c
+ *
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * A leverage of logic from uIP which also has a BSD style license
+ *
+ *   Copyright (c) 2006, Swedish Institute of Computer Science.  All rights
+ *     reserved.
+ *   Author: Adam Dunkels <adam@sics.se>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/clock.h>
+
+#include "neighbor/neighbor.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+#define USEC_PER_HSEC    500000
+#define TICK_PER_HSEC    (USEC_PER_HSEC / USEC_PER_TICK)   /* Truncates! */
+#define TICK2HSEC(tick)  (((tick)+(TICK_PER_HSEC/2))/TICK_PER_HSEC) /* Rounds */
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: neighbor_periodic
+ *
+ * Description:
+ *   Called from the timer poll logic in order to perform agin operations on
+ *   entries in the Neighbor Table
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_periodic(void)
+{
+  uint32_t now;
+  uint32_t ticks;
+  uint32_t hsecs;
+  int i;
+
+  /* Get the elapsed time in units of half seconds */
+
+  now   = clock_systimer();
+  ticks = now - g_neighbor_polltime;
+  hsecs = TICK2HSEC(ticks);
+
+  /* Reset the time of the last poll */
+
+  g_neighbor_polltime = now;
+
+  /* Add the elapsed half seconds from each activate entry in the
+   * Neighbor table.
+   */
+
+  for (i = 0; i < CONFIG_NET_IPv6_NCONF_ENTRIES; ++i)
+    {
+      uint32_t newtime = g_neighbors[i].ne_time + hsecs;
+      if (newtime > NEIGHBOR_MAXTIME)
+        {
+          newtime = NEIGHBOR_MAXTIME;
+        }
+
+      g_neighbors[i].ne_time = newtime;
+    }
+}
diff --git a/nuttx/net/neighbor/neighbor_update.c b/nuttx/net/neighbor/neighbor_update.c
new file mode 100644
index 000000000..e0d44e253
--- /dev/null
+++ b/nuttx/net/neighbor/neighbor_update.c
@@ -0,0 +1,77 @@
+/****************************************************************************
+ * net/neighbor/neighbor_update.c
+ *
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * A leverage of logic from uIP which also has a BSD style license
+ *
+ *   Copyright (c) 2006, Swedish Institute of Computer Science.  All rights
+ *     reserved.
+ *   Author: Adam Dunkels <adam@sics.se>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "neighbor/neighbor.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: neighbor_update
+ *
+ * Description:
+ *   Reset time on the Neighbor Table entry associated with the IPv6 address.
+ *   This makes the associated entry the most recently used and not a
+ *   candidate for removal.
+ *
+ * Input Parameters:
+ *   ipaddr - The IPv6 address of the entry to be updated
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void neighbor_update(net_ipv6addr_t ipaddr)
+{
+  struct neighbor_entry *neighbor;
+
+  neighbor = neighbor_findentry(ipaddr);
+  if (neighbor != NULL)
+    {
+      neighbor->ne_time = 0;
+    }
+}