From 787430613efcdf499330ca89d7d7ece0ccb6311f Mon Sep 17 00:00:00 2001
From: Tommaso Pecorella <tommaso.pecorella@unifi.it>
Date: Wed, 28 Sep 2016 02:13:32 +0200
Subject: [PATCH] network: (workaround for #2505) Printing a packet can raise
 an assert

---
 src/internet/model/icmpv4.cc        | 16 +++++++++-------
 src/internet/model/icmpv6-header.cc |  8 ++++----
 src/internet/model/rip-header.cc    |  2 +-
 src/internet/model/ripng-header.cc  |  2 +-
 src/network/model/buffer.cc         |  7 +++++++
 src/network/model/buffer.h          |  5 +++++
 6 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/src/internet/model/icmpv4.cc b/src/internet/model/icmpv4.cc
index 565723975..9e8e1eeaa 100644
--- a/src/internet/model/icmpv4.cc
+++ b/src/internet/model/icmpv4.cc
@@ -247,24 +247,26 @@ uint32_t
 Icmpv4Echo::Deserialize (Buffer::Iterator start)
 {
   NS_LOG_FUNCTION (this << &start);
+
+  uint32_t optionalPayloadSize = start.GetRemainingSize () -4;
+  NS_ASSERT (start.GetRemainingSize () >= 4);
+
   m_identifier = start.ReadNtohU16 ();
   m_sequence = start.ReadNtohU16 ();
-  NS_ASSERT (start.GetSize () >= 4);
-  uint32_t size = start.GetSize () - 4;
-  if (size != m_dataSize)
+  if (optionalPayloadSize != m_dataSize)
     {
       delete [] m_data;
-      m_data = new uint8_t[size];
-      m_dataSize = size;
+      m_dataSize = optionalPayloadSize;
+      m_data = new uint8_t[m_dataSize];
     }
   start.Read (m_data, m_dataSize);
-  return m_dataSize;
+  return m_dataSize+4;
 }
 void 
 Icmpv4Echo::Print (std::ostream &os) const
 {
   NS_LOG_FUNCTION (this << &os);
-  os << "identifier=" << m_identifier << ", sequence="  << m_sequence;
+  os << "identifier=" << m_identifier << ", sequence="  << m_sequence << ", data size=" << m_dataSize;
 }
 
 
diff --git a/src/internet/model/icmpv6-header.cc b/src/internet/model/icmpv6-header.cc
index ba7ad7f74..84e2d8d4f 100644
--- a/src/internet/model/icmpv6-header.cc
+++ b/src/internet/model/icmpv6-header.cc
@@ -1123,7 +1123,7 @@ void Icmpv6DestinationUnreachable::Serialize (Buffer::Iterator start) const
 uint32_t Icmpv6DestinationUnreachable::Deserialize (Buffer::Iterator start)
 {
   NS_LOG_FUNCTION (this << &start);
-  uint16_t length = start.GetSize () - 8;
+  uint16_t length = start.GetRemainingSize () - 8;
   uint8_t* data = new uint8_t[length];
   Buffer::Iterator i = start;
 
@@ -1234,7 +1234,7 @@ void Icmpv6TooBig::Serialize (Buffer::Iterator start) const
 uint32_t Icmpv6TooBig::Deserialize (Buffer::Iterator start) 
 {
   NS_LOG_FUNCTION (this << &start);
-  uint16_t length = start.GetSize () - 8;
+  uint16_t length = start.GetRemainingSize () - 8;
   uint8_t* data = new uint8_t[length];
   Buffer::Iterator i = start;
 
@@ -1334,7 +1334,7 @@ uint32_t Icmpv6TimeExceeded::Deserialize (Buffer::Iterator start)
 {
   NS_LOG_FUNCTION (this << &start);
   
-  uint16_t length = start.GetSize () - 8;
+  uint16_t length = start.GetRemainingSize () - 8;
   uint8_t* data = new uint8_t[length];
   Buffer::Iterator i = start;
 
@@ -1445,7 +1445,7 @@ void Icmpv6ParameterError::Serialize (Buffer::Iterator start) const
 uint32_t Icmpv6ParameterError::Deserialize (Buffer::Iterator start) 
 {
   NS_LOG_FUNCTION (this << &start);
-  uint16_t length = start.GetSize () - 8;
+  uint16_t length = start.GetRemainingSize () - 8;
   uint8_t* data = new uint8_t[length];
   Buffer::Iterator i = start;
 
diff --git a/src/internet/model/rip-header.cc b/src/internet/model/rip-header.cc
index 5631f0b68..763029717 100644
--- a/src/internet/model/rip-header.cc
+++ b/src/internet/model/rip-header.cc
@@ -225,7 +225,7 @@ uint32_t RipHeader::Deserialize (Buffer::Iterator start)
   uint16_t temp16 = i.ReadU16 ();
   NS_ASSERT_MSG (temp16 == 0, "RIP received a message with invalid filled flags, aborting.");
 
-  uint8_t rteNumber = (i.GetSize () - 4)/20;
+  uint8_t rteNumber = i.GetRemainingSize ()/20;
   for (uint8_t n=0; n<rteNumber; n++)
     {
       RipRte rte;
diff --git a/src/internet/model/ripng-header.cc b/src/internet/model/ripng-header.cc
index 7ca341818..f5092913a 100644
--- a/src/internet/model/ripng-header.cc
+++ b/src/internet/model/ripng-header.cc
@@ -208,7 +208,7 @@ uint32_t RipNgHeader::Deserialize (Buffer::Iterator start)
   uint16_t temp16 = i.ReadU16 ();
   NS_ASSERT_MSG (temp16 == 0, "RipNG received a message with invalid filled flags, aborting.");
 
-  uint8_t rteNumber = (i.GetSize () - 4)/20;
+  uint8_t rteNumber = i.GetRemainingSize ()/20;
   for (uint8_t n=0; n<rteNumber; n++)
     {
       RipNgRte rte;
diff --git a/src/network/model/buffer.cc b/src/network/model/buffer.cc
index 86b38b291..ed467ec48 100644
--- a/src/network/model/buffer.cc
+++ b/src/network/model/buffer.cc
@@ -1161,6 +1161,13 @@ Buffer::Iterator::GetSize (void) const
   return m_dataEnd - m_dataStart;
 }
 
+uint32_t
+Buffer::Iterator::GetRemainingSize (void) const
+{
+  NS_LOG_FUNCTION (this);
+  return m_dataEnd - m_current;
+}
+
 
 std::string 
 Buffer::Iterator::GetReadErrorMessage (void) const
diff --git a/src/network/model/buffer.h b/src/network/model/buffer.h
index 3074e0bf0..373d2e4f0 100644
--- a/src/network/model/buffer.h
+++ b/src/network/model/buffer.h
@@ -376,6 +376,11 @@ public:
      */
     uint32_t GetSize (void) const;
 
+    /**
+     * \returns the size left to read of the underlying buffer we are iterating
+     */
+    uint32_t GetRemainingSize (void) const;
+
 private:
     friend class Buffer;
     /**