From 7cc8b40f8852be685b634d101e7c4e7feeb10654 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= <sebastien.deronne@gmail.com>
Date: Sat, 7 Nov 2015 23:37:44 +0100
Subject: [PATCH] Bug 2176 - Building IPv4 address from char* doesn't look
 reliable

---
 RELEASE_NOTES                     |  1 +
 src/network/utils/ipv4-address.cc | 18 +++++++++++++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 0346d71dd..94f5108ab 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -45,6 +45,7 @@ Bugs fixed
 - Bug 2041 - TCP RTO needs unit tests
 - Bug 2150 - The TCP sender keeps retransmitting and does not terminate the connection after some retries.
 - Bug 2159 - TCP advertises wrong receive window
+- Bug 2176 - Building IPv4 address from char* doesn't look reliable
 - Bug 2183 - LiIonEnergySourceHelper is not in the energy wscript
 - Bug 2185 - WiFi MacLow may respond to errored frames that it should ignore
 - Bug 2195 - Udp[*]Client can't send packets to broadcast address
diff --git a/src/network/utils/ipv4-address.cc b/src/network/utils/ipv4-address.cc
index 1b45324a0..3731aca39 100644
--- a/src/network/utils/ipv4-address.cc
+++ b/src/network/utils/ipv4-address.cc
@@ -41,23 +41,31 @@ AsciiToIpv4Host (char const *address)
 {
   NS_LOG_FUNCTION (&address);
   uint32_t host = 0;
+  uint8_t numberOfDots = 0;
+  char const *ptr = address;
+
+  NS_ASSERT_MSG (*ptr != ASCII_DOT, "Error, can not build an IPv4 address from an invalid string: " << address);
   while (true) 
     {
       uint8_t byte = 0;
-      while (*address != ASCII_DOT && *address != 0) 
+      while (*ptr != ASCII_DOT && *ptr != 0)
         {
           byte *= 10;
-          byte += *address - ASCII_ZERO;
-          address++;
+          byte += *ptr - ASCII_ZERO;
+          ptr++;
         }
       host <<= 8;
       host |= byte;
-      if (*address == 0) 
+      if (*ptr == 0)
         {
           break;
         }
-      address++;
+      ptr++;
+      numberOfDots ++;
     }
+  NS_ASSERT_MSG (*(ptr-1) != ASCII_DOT, "Error, can not build an IPv4 address from an invalid string: " << address);
+  NS_ASSERT_MSG (numberOfDots == 3, "Error, can not build an IPv4 address from an invalid string: " << address);
+
   return host;
 }