reading http packets in C

I am trying to access the HTTP environment variables, particularly
REMOTE_ADDR
HTTP_VIA
HTTP_X_FORWARDED_FOR

i have written a small program that dumps the contents of a http packet to the screen, but i cant see the full set of variables i want. Does anyone know how i can access the full set of http variables.
(Linux, gcc)

This is the output of my program:

HTTP-Dump is starting on port 80
HTTP-Dump is listening on port 80


Waiting for a connection
Connection :
packet recieved :
packet size: 8500
GET http://www.google.com/ HTTP/1.1
Host: www.google.com
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7) Gecko/20040618
Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Proxy-Connection: keep-alive
Cookie: PREF=ID=730cd87420aa9d66:CR=1:TM=1108661555:LM=110 8755738:GM=1:S=o86Whlr8YN1seXdf

HTTP_VIA and HTTP_X_FORWARDED_FOR are optionally added by proxy servers and will not be present for a direct connection. REMOTE_ADDR is a cgi variable that is set to the remote address of the client (as returned by accept). It is not part of the request packet. You should not rely on any variable being present.