Reading Route-Metric

Hello,

I've been trying for some time now to find a solution to my problem.  
Since I a new to the kernel I was hoping that someone with more  
experience could help me by giving me a hint on how to solve my problem.
I am writing a Kernel Module and I need to read out the Route-Metric- 
Value of a socket. I want to do this from within TCP, so I can access  
the structs "socket" and "sock" of the socket. As of now, I haven't  
found a way to find out the wanted value with the data I have given. I  
would be grateful, if somebody could give me a hint on how to  
accomplish that task.

Thank you for you Help

Tim Schneider