How to convert SOCK_DGRAM to SOCK_RAW?

Question

I'm working on an open source where SOCK_DGRAM is used to send RTP packets.

Like this:

 int sock = socket(af, SOCK_DGRAM, 0);

But i'm supposed to use the same socket as SOCK_RAW to send the UDP packets that i prepare.

Is this possible to convert the UDP socket to RAW socket?

if it is possible how it can be done?

Thanks in advance

Answer 1

I don't know why you said need to use same socket, otherwise, you can follow the below steps to transfer packet over RAW socket.

1. create the socket using SOCK_RAW.
2. define and populate the IP header [struct ipheader]
3. define and populate the UDP header [struct udphdr]
4. set the socket for not to use a system (kernel) provied header [setsockopt() for IP_HDRINCLas 1]
5. send the buffer [sendto()]

You can find some nice tutorials (and maybe some sample codes, too) here.