Assert failed (buffer.h) when I add trail to the packet

[Peng Wang]

Hi, all,

I need to add data to existing packet, and I find a tutorial about it. I choose to use trailer to carry data, and then add it to the packet. Then, I create mytrailer.cc and mytrailer.h file totally according to the tutorial.

http://www.nsnam.org/support/faq/miscellaneous/

However, it seems that there are something wrong with it. 

assert failed. cond="Check (m_current)", msg="You have attempted to write after the end of the available buffer space. This usually indicates that Header::GetSerializedSize returned a size which is too small compared to what Header::Serialize is actually using."

Does anyone have any solutions? Thanks in advance!

Best,

Peng

[Konstantinos]

You need to be careful on the Serialize and Deserialize methods and also the GetSerializedSize which gives the number of bytes you have written.

[Peng Wang]

Hi Konstantinos,

Thanks for your help! I only add a data (m_data) which is of type uint32_t. I returned the GetSerializedSize() as 4. 

The Serialize and Deserialize methods are simple here. 

void::MyTrailer::Serialize (Buffer::Iterator start) const

{

      start.WriteU32(m_data);

}

uint32_t MyTrailer::Deserialize (Buffer::Iterator start)

{
       m_data = start.ReadU32();

       return GetSerializedSize();