extract packet's header

[Sara]

Dear All,

I made some modification in the UdpHeader.h , that if I have packet P then I can say p.data = "xx.." .

and my question is how can I read this data at the received packet, because the header is part of the packet and this inserted data is part of the header, so to read the data in the header should be possible 

thanks a lot

Regards

[phuchong kheawchaoom]

I think that the packet can be read by this method but i am not sure.   

uint8_t *buffer = new uint8_t[packet->GetSize()]; 

          pk->CopyData (buffer, packetk->GetSize()); 

                         string data = string((char*)buffer);

Good luck

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[Sara]

Dear  kheawchaoom,

thanks a lot, but it is not exactly what I need but it could help and I have question please

what do you mean by pk do you mean that I should create new packet called pk or do you mean the same previous packet

another question : can I use your way to enter a string data like name to the source node to the packet

and then at the receiver I make a copy for this data

thank you again

Regards

On Saturday, June 2, 2012 3:52:12 PM UTC+2, phuchong kheawchaoom wrote:

I think that the packet can be read by this method but i am not sure.   

uint8_t *buffer = new uint8_t[packet->GetSize()]; 

          pk->CopyData (buffer, packetk->GetSize()); 

                         string data = string((char*)buffer);

Good luck

[phuchong kheawchaoom]

sorry for my error.

At sender, you can create a packet by this way. 

 stringstream msgx;

                msgx << " abcdefg or your data " ;

                uint16_t packetSize = 800;

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

At receiver, you can read the data by this way

  uint8_t *buffer = new uint8_t[packet->GetSize()]; 

        packet->CopyData (buffer, packet->GetSize());

                        string data = string((char*)buffer);

 

I hope it works.

Regards

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[Sara]

thank you very much, it works perfectly 

it was really helpful for me 

Best Regards

Sara

On Saturday, June 2, 2012 5:54:43 PM UTC+2, phuchong kheawchaoom wrote:

sorry for my error.

At sender, you can create a packet by this way. 

 stringstream msgx;

                msgx << " abcdefg or your data " ;

                uint16_t packetSize = 800;

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

At receiver, you can read the data by this way

  uint8_t *buffer = new uint8_t[packet->GetSize()]; 

        packet->CopyData (buffer, packet->GetSize());

                        string data = string((char*)buffer);

 

I hope it works.

Regards

[Sara]

Hello  kheawchaoom,

it is me again, your answer last time helped me and I hope you can help me now again

actually I am at the same subject, it took a lot of time

I would like to ask you how can I read the packet from the receiver node

for transmitter i am using Send(packet)

and at the receiver I am using Recv();

as the following code

  TypeId tid = TypeId::LookupByName ("ns3::UdpSocketFactory");

  Ptr<Socket> destination = Socket::CreateSocket (c.Get (sinkNode), tid);// where sinkNode is node number 0;

  InetSocketAddress local = InetSocketAddress (Ipv4Address::GetAny (), 8);

  destination->Bind (local);

  Ptr<Socket> source = Socket::CreateSocket (c.Get (sourceNode), tid);

  InetSocketAddress remote = InetSocketAddress (i.GetAddress (sinkNode, 0), 8);

  source->Connect (remote);

   Ptr<Packet> recPacket = Create<Packet> ();

   Ptr<Packet> Packet1 = Create<Packet> (10);

   source->Send(Packet1);

    recPacket = destination->Recv();

   recPacket->GetSize(); // here is the error 

and at last line it always give an error, because it give a zero received packet 

so can you please tell me what is the wrong, and how can I read the packet from the socket at the node, and then to read the data

I really appreciate your help

Sara

[phuchong kheawchaoom]

http://www.nsnam.org/doxygen-release/classns3_1_1_socket.html#a97f08aaf37b8fd7d4b5cad4dfdd4022a

Detailed Description

A low-level Socket API based loosely on the BSD Socket API.

A few things to keep in mind about this type of socket:

• it uses ns-3 API constructs such as class ns3::Address instead of C-style structs
• in contrast to the original BSD socket API, this API is asynchronous: it does not contain blocking calls. Sending and receiving operations must make use of the callbacks provided.
• It also uses class ns3::Packet as a fancy byte buffer, allowing data to be passed across the API using an ns-3 Packet instead of a raw data pointer.
• Not all of the full POSIX sockets API is supported

Other than that, it tries to stick to the BSD API to make it easier for those who know the BSD API to use this API. More details are provided in the ns-3 tutorial.

I do not know it too but I guess that you do not make call a call back in your simulation.

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[Poonam Mishra]

can u give the full program of this???????????please

i want to stream a rtmp url.............

[R.C Duan]

Hi Stephanie，

It looks like I'm facing the same problem. I'm going to modify IP header of packets through a router, but don't know how routers/nodes receive a packet then forward it. So I viewed some source code, only find where TTL minus one is. 

So about your problem, did you figure it out? Maybe your solution would be helpful to me.

thanks a lot.

Regards

在 2012年6月16日星期六 UTC+8上午7:30:04，Stephan写道：

[Tommaso Pecorella]

Please read the posting guidelines AND the thread's date.

T.