How to use the RTM_IFINFO message of a Routing Socket

[Juan Rodriguez Hervella]

Hello,

I dont understand, looking at "man 4 route", how to use the RTM_IFINFO
message of a Routing Socket.

I mean, do I have to make a "write" on the socket with a 
"struct if_msghdr" of type = RTM_IFINFO and later on a "read" with
the same data structure ?

Or can I just open the PF_ROUTE socket and then make a "read" with 
a "struct if_msghdr" data structure, w/out doing a "write" ?

I'm really lost, and I haven't found documentation about this topic, so 
please if somebody can give me an example or pointing me to
somewhere to learn to use this, I'd be delighted. Looking at 
"usr/src/bin/route.c" is simple another big mess for me.

I'm looking forward to your answers, net-people !

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JFRH
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