Question

I have a port that is bind()’d to INADDR_ANY. I am receiving datagrams successfully. After receipt, I need to read the IP header to get the source IP address.

Answer 1

I don’t believe you can get it if you’re using the standard recv or read function calls. The recvfrom call as follows:

int recvfrom(   __in         SOCKET s,   __out        char *buf,   __in         int len,   __in         int flags,   __out        struct sockaddr *from,   __inout_opt  int *fromlen ); 

includes a structure (the second to last field above) which will receive the source address which you can examine for whatever purposes you desire.