IPv6: Separate function that converts prefix lengths to a netmask

include/nuttx/net/ip.h

@@ -365,28 +365,37 @@ EXTERN const net_ipv6addr_t g_ipv6_llnetmask;   /* Netmask for local link addres
    net_ipv6addr_cmp(addr1, addr2)
 #endif
 
-/* Compare two IP addresses under a netmask.  The mask is used to mask
+/****************************************************************************
- * out the bits that are to be compared:  Buts within the mask much
+ * Function: net_ipv4addr_maskcmp and net_ipv6addr_maskcmp
- * match exactly; bits outside if the mask are ignored.
  *
- * Example:
+ * Description:
+ *   Compare two IP addresses under a netmask.  The mask is used to mask
+ *   out the bits that are to be compared:  Buts within the mask much
+ *   match exactly; bits outside if the mask are ignored.
  *
- *   in_addr_t ipaddr1;
+ * IPv4 Example:
- *   in_addr_t ipaddr2;
- *   in_addr_t mask;
  *
- *   net_ipaddr(&mask, 255,255,255,0);
+ *   net_ipv6addr_t ipaddr1;
- *   net_ipaddr(&ipaddr1, 192,16,1,2);
+ *   net_ipv6addr_t ipaddr2;
- *   net_ipaddr(&ipaddr2, 192,16,1,3);
+ *   net_ipv6addr_t mask;
- *   if (net_ipv4addr_maskcmp(ipaddr1, ipaddr2, &mask))
+ *
+ *   net_ipv6addr(&mask, 255,255,255,0);
+ *   net_ipv6addr(&ipaddr1, 192,16,1,2);
+ *   net_iv6paddr(&ipaddr2, 192,16,1,3);
+ *   if (net_ipv6addr_maskcmp(ipaddr1, ipaddr2, &mask))
  *     {
  *       printf("They are the same");
  *     }
  *
- * addr1 The first IP address.
+ * Parameters:
- * addr2 The second IP address.
+ *   addr1 - The first IP address.
- * mask The netmask.
+ *   addr2 - The second IP address.
- */
+ *   mask  - The netmask.
+ *
+ * Returned Value:
+ *   True if the address under the mask are equal
+ *
+ ****************************************************************************/
 
 #ifdef CONFIG_NET_IPv4
 #  define net_ipv4addr_maskcmp(addr1, addr2, mask) \

net/icmpv6/icmpv6_autoconfig.c

@@ -515,6 +515,10 @@ int icmpv6_autoconfig(FAR struct net_driver_s *dev)
           netdev_ifdown(dev);
         }
 
+      /* No off-link communications; No router address. */
+
+      net_ipv6addr_copy(dev->d_ipv6draddr, g_ipv6_allzeroaddr);
+
       /* Set a netmask for the local link address */
 
       net_ipv6addr_copy(dev->d_ipv6netmask, g_ipv6_llnetmask);

net/icmpv6/icmpv6_ping.c

@@ -322,9 +322,9 @@ static uint16_t ping_interrupt(FAR struct net_driver_s *dev, FAR void *conn,
           if (!net_ipv6addr_maskcmp(pstate->png_addr, dev->d_ipv6addr,
                                     dev->d_ipv6netmask))
             {
-              /* Destination address was not on the local network served by this
+              /* Destination address was not on the local network served by
-               * device.  If a timeout occurs, then the most likely reason is
+               * this device.  If a timeout occurs, then the most likely
-               * that the destination address is not reachable.
+               * reason is that the destination address is not reachable.
                */
 
               nlldbg("Not reachable\n");

net/icmpv6/icmpv6_rnotify.c

@@ -51,6 +51,7 @@
 #include <arch/irq.h>
 
 #include "netdev/netdev.h"
+#include "utils/utils.h"
 #include "icmpv6/icmpv6.h"
 
 #ifdef CONFIG_NET_ICMPv6_AUTOCONF
@@ -89,64 +90,25 @@ static void icmpv6_setaddresses(FAR struct net_driver_s *dev,
                                 const net_ipv6addr_t prefix,
                                 unsigned int preflen)
 {
-  unsigned int bit;
   unsigned int i;
 
   /* Make sure that the network is down before changing any addresses */
 
   netdev_ifdown(dev);
 
-  /* Set the network mask.  preflen is the number of MS bits under the mask.
+  /* Create an address mask from the prefix */
-   *
-   * Eg. preflen = 38
-   *     NETMASK: ffff ffff fc00 0000  0000 0000 0000 0000
-   *     bit:                                       1 1..1
-   *                 1 1..3 3..4 4..6  6..7 8..9 9..1 1..2  
-   *              0..5 6..1 2..7 8..3  4..9 0..5 6..1 2..7
-   *     preflen:                                   1 1..1
-   *                 1 1..3 3..4 4..6  6..8 8..9 9..1 1..2
-   *              1..6 7..2 3..8 9..4  5..0 1..6 7..2 3..8
-   */
 
-  for (i = 0; i < 7; i++)
+  if (preflen > 128)
     {
-      /* bit = {0, 16, 32, 48, 64, 80, 96, 112} */
+      preflen = 128;
-
-      bit = i << 4;
-
-      if (preflen > bit)
-        {
-          /* Eg. preflen = 38, bit = {0, 16, 32} */
-
-          if (preflen > (bit + 16))
-            {
-              /* Eg. preflen = 38, bit = {0, 16} */
-
-              dev->d_ipv6netmask[i] = 0xffff;
-            }
-          else
-            {
-              /* Eg. preflen = 38, bit = {32}
-               *     bit - preflen = 6
-               *     make = 0xffff << (16-6)
-               *          = 0xfc00
-               */
-
-              dev->d_ipv6netmask[i]  = 0xffff << (16 - (bit - preflen));
-            }
-        }
-      else
-        {
-          /* Eg. preflen=38, bit= {48, 64, 80, 112} */
-
-          dev->d_ipv6netmask[i] = 0x0000;
-        }
     }
 
+  net_ipv6_pref2mask(preflen, dev->d_ipv6netmask);
+
   nvdbg("preflen=%d netmask=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
         preflen, dev->d_ipv6netmask[0], dev->d_ipv6netmask[1],
         dev->d_ipv6netmask[2], dev->d_ipv6netmask[3], dev->d_ipv6netmask[4],
-        dev->d_ipv6netmask[6], dev->d_ipv6netmask[6], dev->d_ipv6netmask[7]);
+        dev->d_ipv6netmask[5], dev->d_ipv6netmask[6], dev->d_ipv6netmask[7]);
 
   /* Copy prefix to the current IPv6 address, applying the mask */
 

net/utils/Make.defs

@@ -41,7 +41,7 @@ NET_CSRCS += net_chksum.c
 # IPv6 utilities
 
 ifeq ($(CONFIG_NET_IPv6),y)
-NET_CSRCS += net_ipv6_maskcmp.c
+NET_CSRCS += net_ipv6_maskcmp.c net_ipv6_pref2mask.c
 endif
 
 # Non-interrupt level support required?

net/utils/net_ipv6_maskcmp.c

@@ -51,27 +51,13 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Function: net_timeval2dsec
+ * Function: net_ipv6addr_maskcmp
  *
  * Description:
- *   Compare two IP addresses under a netmask.  The mask is used to mask
+ *   Compare two IPv6 addresses under a netmask.  The mask is used to mask
  *   out the bits that are to be compared:  Buts within the mask much
  *   match exactly; bits outside if the mask are ignored.
  *
- * Example:
- *
- *   net_ipv6addr_t ipaddr1;
- *   net_ipv6addr_t ipaddr2;
- *   net_ipv6addr_t mask;
- *
- *   net_ipv6addr(&mask, 255,255,255,0);
- *   net_ipv6addr(&ipaddr1, 192,16,1,2);
- *   net_iv6paddr(&ipaddr2, 192,16,1,3);
- *   if (net_ipv6addr_maskcmp(ipaddr1, ipaddr2, &mask))
- *     {
- *       printf("They are the same");
- *     }
- *
  * Parameters:
  *   addr1 - The first IP address.
  *   addr2 - The second IP address.

net/utils/net_ipv6_pref2mask.c

@@ -0,0 +1,122 @@
+/****************************************************************************
+ * net/utils/net_ipv6_pref2mask.c
+ *
+ *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 NuttX 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 COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <nuttx/net/ip.h>
+
+#include "utils/utils.h"
+
+#ifdef CONFIG_NET_IPv6
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: net_ipv6_pref2mask
+ *
+ * Description:
+ *   Convert a IPv6 prefix length to a network mask.  The prefix length
+ *   specifies the number of MS bits under mask (0-128)
+ *
+ * Parameters:
+ *   preflen  - Determines the width of the netmask (in bits).  Range 0-128
+ *   mask  - The location to return the netmask.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void net_ipv6_pref2mask(uint8_t preflen, net_ipv6addr_t mask)
+{
+  unsigned int bit;
+  unsigned int i;
+
+  /* Set the network mask.  preflen is the number of MS bits under the mask.
+   *
+   * Eg. preflen = 38
+   *     NETMASK: ffff ffff fc00 0000  0000 0000 0000 0000
+   *     bit:                                       1 1..1
+   *                 1 1..3 3..4 4..6  6..7 8..9 9..1 1..2  
+   *              0..5 6..1 2..7 8..3  4..9 0..5 6..1 2..7
+   *     preflen:                                   1 1..1
+   *                 1 1..3 3..4 4..6  6..8 8..9 9..1 1..2
+   *              1..6 7..2 3..8 9..4  5..0 1..6 7..2 3..8
+   */
+
+  for (i = 0; i < 7; i++)
+    {
+      /* bit = {0, 16, 32, 48, 64, 80, 96, 112} */
+
+      bit = i << 4;
+
+      if (preflen > bit)
+        {
+          /* Eg. preflen = 38, bit = {0, 16, 32} */
+
+          if (preflen > (bit + 16))
+            {
+              /* Eg. preflen = 38, bit = {0, 16} */
+
+              mask[i] = 0xffff;
+            }
+          else
+            {
+              /* Eg. preflen = 38, bit = {32}
+               *     bit - preflen = 6
+               *     make = 0xffff << (16-6)
+               *          = 0xfc00
+               */
+
+              mask[i]  = 0xffff << (16 - (bit - preflen));
+            }
+        }
+      else
+        {
+          /* Eg. preflen=38, bit= {48, 64, 80, 112} */
+
+          mask[i] = 0x0000;
+        }
+    }
+}
+
+#endif /* CONFIG_NET_IPv6 */

net/utils/utils.h

@@ -41,6 +41,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <nuttx/net/ip.h>
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -138,6 +139,26 @@ unsigned int net_dsec2tick(int dsec);
 
 unsigned int net_timeval2dsec(FAR struct timeval *tv);
 
+/****************************************************************************
+ * Function: net_ipv6_pref2mask
+ *
+ * Description:
+ *   Convert a IPv6 prefix length to a network mask.  The prefix length
+ *   specifies the number of MS bits under mask (0-128)
+ *
+ * Parameters:
+ *   preflen  - Determines the width of the netmask (in bits).  Range 0-128
+ *   mask  - The location to return the netmask.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NET_IPv6
+void net_ipv6_pref2mask(uint8_t preflen, net_ipv6addr_t mask);
+#endif
+
 /****************************************************************************
  * Name: tcp_chksum, tcp_ipv4_chksum, and tcp_ipv6_chksum
  *
@@ -174,7 +195,6 @@ uint16_t tcp_chksum(FAR struct net_driver_s *dev);
 #  define tcp_chksum(d) tcp_ipv6_chksum(d)
 #endif
 
-
 /****************************************************************************
  * Name: udp_ipv4_chksum
  *