net/neighbor: Simplify the neighbor table aging process

net/devif/devif_poll.c

@@ -50,7 +50,6 @@
 
 #include "devif/devif.h"
 #include "arp/arp.h"
-#include "neighbor/neighbor.h"
 #include "tcp/tcp.h"
 #include "udp/udp.h"
 #include "pkt/pkt.h"
@@ -787,12 +786,6 @@ int devif_timer(FAR struct net_driver_s *dev, devif_poll_callback_t callback)
         }
 #endif
 
-#ifdef CONFIG_NET_IPv6
-      /* Perform aging on the entries in the Neighbor Table */
-
-       neighbor_periodic(hsec);
-#endif
-
 #ifdef NET_TCP_HAVE_STACK
       /* Traverse all of the active TCP connections and perform the
        * timer action.

net/neighbor/Make.defs

@@ -37,8 +37,8 @@
 
 ifeq ($(CONFIG_NET_IPv6),y)
 
-NET_CSRCS += neighbor_initialize.c neighbor_add.c neighbor_lookup.c
+NET_CSRCS += neighbor_globals.c neighbor_add.c neighbor_lookup.c
-NET_CSRCS += neighbor_update.c neighbor_periodic.c neighbor_findentry.c
+NET_CSRCS += neighbor_update.c neighbor_findentry.c
 
 # Link layer specific support
 

net/neighbor/neighbor.h

@@ -64,8 +64,6 @@
 #  define CONFIG_NET_IPv6_NCONF_ENTRIES 8
 #endif
 
-#define NEIGHBOR_MAXTIME 128
-
 /****************************************************************************
  * Public Types
  ****************************************************************************/
@@ -96,7 +94,7 @@ 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 */
+  clock_t                ne_time;    /* For aging, units of tick */
 };
 
 /****************************************************************************
@@ -115,25 +113,6 @@ extern struct neighbor_entry g_neighbors[CONFIG_NET_IPv6_NCONF_ENTRIES];
 
 struct net_driver_s; /* Forward reference */
 
-/****************************************************************************
- * Name: neighbor_initialize
- *
- * Description:
- *   Initialize Neighbor table data structures.  This function is called
- *   prior to platform-specific driver initialization so that the networking
- *   subsystem is prepared to deal with network driver initialization
- *   actions.
- *
- * Input Parameters:
- *   None
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-void neighbor_initialize(void);
-
 /****************************************************************************
  * Name: neighbor_findentry
  *
@@ -208,23 +187,6 @@ FAR const struct neighbor_addr_s *neighbor_lookup(const net_ipv6addr_t ipaddr);
 
 void neighbor_update(const 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:
- *   hsec - Elapsed time in half seconds since the last check
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-void neighbor_periodic(int hsec);
-
 /****************************************************************************
  * Name: neighbor_dumpentry
  *

net/neighbor/neighbor_add.c

@@ -81,7 +81,7 @@ void neighbor_add(FAR struct net_driver_s *dev, FAR net_ipv6addr_t ipaddr,
                   FAR uint8_t *addr)
 {
   uint8_t lltype;
-  uint8_t oldest_time;
+  clock_t oldest_time;
   int     oldest_ndx;
   int     i;
 
@@ -89,18 +89,12 @@ void neighbor_add(FAR struct net_driver_s *dev, FAR net_ipv6addr_t ipaddr,
 
   /* Find the first unused entry or the oldest used entry. */
 
-  oldest_time = 0;
+  oldest_time = g_neighbors[0].ne_time;
   oldest_ndx  = 0;
   lltype      = dev->d_lltype;
 
   for (i = 0; i < CONFIG_NET_IPv6_NCONF_ENTRIES; ++i)
     {
-      if (g_neighbors[i].ne_time == NEIGHBOR_MAXTIME)
-        {
-          oldest_ndx = i;
-          break;
-        }
-
       if (g_neighbors[i].ne_addr.na_lltype == lltype &&
           net_ipv6addr_cmp(g_neighbors[i].ne_ipaddr, ipaddr))
         {
@@ -108,7 +102,7 @@ void neighbor_add(FAR struct net_driver_s *dev, FAR net_ipv6addr_t ipaddr,
           break;
         }
 
-      if (g_neighbors[i].ne_time > oldest_time)
+      if ((int)(g_neighbors[i].ne_time - oldest_time) < 0)
         {
           oldest_ndx = i;
           oldest_time = g_neighbors[i].ne_time;
@@ -119,7 +113,7 @@ void neighbor_add(FAR struct net_driver_s *dev, FAR net_ipv6addr_t ipaddr,
    * "oldest_ndx" variable).
    */
 
-  g_neighbors[oldest_ndx].ne_time = 0;
+  g_neighbors[oldest_ndx].ne_time = clock_systimer();
   net_ipv6addr_copy(g_neighbors[oldest_ndx].ne_ipaddr, ipaddr);
 
   g_neighbors[oldest_ndx].ne_addr.na_lltype = lltype;

net/neighbor/neighbor_initialize.c

@@ -1,88 +0,0 @@
-/****************************************************************************
- * 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];
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
-/****************************************************************************
- * Name: neighbor_initialize
- *
- * Description:
- *   Initialize Neighbor table data structures.  This function is called
- *   prior to platform-specific driver initialization so that the networking
- *   subsystem is prepared to deal with network driver initialization
- *   actions.
- *
- * 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;
-    }
-}

net/neighbor/neighbor_periodic.c

@@ -1,90 +0,0 @@
-/****************************************************************************
- * net/neighbor/neighbor_periodic.c
- *
- *   Copyright (C) 2007-2009, 2015-2016 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_periodic
- *
- * Description:
- *   Called from the timer poll logic in order to perform agin operations on
- *   entries in the Neighbor Table
- *
- * Input Parameters:
- *   hsec - Elapsed time in half seconds since the last check
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-void neighbor_periodic(int hsec)
-{
-  int i;
-
-  /* Only perform the aging when more than a half second has elapsed */
-
-  if (hsec > 0)
-    {
-      /* 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 + hsec;
-          if (newtime > NEIGHBOR_MAXTIME)
-            {
-              newtime = NEIGHBOR_MAXTIME;
-            }
-
-          g_neighbors[i].ne_time = newtime;
-        }
-    }
-}

net/neighbor/neighbor_update.c

@@ -72,6 +72,6 @@ void neighbor_update(const net_ipv6addr_t ipaddr)
   neighbor = neighbor_findentry(ipaddr);
   if (neighbor != NULL)
     {
-      neighbor->ne_time = 0;
+      neighbor->ne_time = clock_systimer();
     }
 }

net/net_initialize.c

@@ -50,7 +50,6 @@
 #include "netdev/netdev.h"
 #include "ipforward/ipforward.h"
 #include "sixlowpan/sixlowpan.h"
-#include "neighbor/neighbor.h"
 #include "icmp/icmp.h"
 #include "icmpv6/icmpv6.h"
 #include "mld/mld.h"
@@ -100,10 +99,6 @@ void net_initialize(void)
   net_lockinitialize();
 
 #ifdef CONFIG_NET_IPv6
-  /* Initialize the Neighbor Table data structures */
-
-  neighbor_initialize();
-
 #ifdef CONFIG_NET_MLD
   /* Initialize ICMPv6 Multicast Listener Discovery (MLD) logic */