ns3数据包有效负载打印

Question

I am using ns3 for a simulation where I create a packet as follows;

std::ostringstream msg; msg << "Hello World!" << '\0';
Ptr<Packet> packet = Create<Packet> ((uint8_t*) msg.str().c_str(), msg.str().length());
packet->Print (cout);
std::cout << std::endl;

In receiver side, I am using following code to retrieve the packet payload;

uint8_t *buffer = new uint8_t[p->GetSize ()];
size = p->CopyData(buffer, p->GetSize ());
string s = string(buffer, buffer+p->GetSize());
cout<<"Received:"<<s<<endl;

However, the packet payload is some weird characters. Moreover, when I run the same code on my other computer with the different message (not hello world), I can see the message with weird characters at the beginning and end of the message. Any suggestion and advice are appreciated.

Regards.

Answer 1

I solve the problem with the help of ns-3 google groups. I am posting the answer, in case others may need.

In sender side, I need to set the message length as follows;

 uint16_t packetSize = msgx.str().length()+1;
 Ptr<Packet> packet = Create<Packet>((uint8_t*) msgx.str().c_str(), packetSize);

I need to add 1 to the message length, or I skip the null string termination. So this one is a minor bug. The major one is; I trigger a function when I receive the packet on MAC layer. To properly read the packet content, I should remove the MAC headers and trailers.

Regards.