lookup_option

[Ted Lemon]

> what does this function lookup_option do?
> where can i find the definition of this function?

Given an option state structure (which is used to record incoming 
options and also to store outgoing options), and given an option space 
and option code, lookup_option returns the option cache structure, if 
any, corresponding to the specified option.   If you just want to know 
that the option is there, you're done.   If you want the value of the 
option, and it's an incoming option, the value is always in the data 
element of the option cache structure.   If the option has been 
generated from the config file, you should call evaluate_option_cache() 
to evaluate the tree element of the option cache structure.   The 
result is stored in the data element.   You can see examples of this 
usage all over dhcp.c.

This sort of question is really more appropriate for the 
dhcp-hackers at isc.org mailing list.   :')