dn_expand()

Expand a compressed Internet domain name

Synopsis:

#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

int dn_expand( const u_char * msg, 
               const u_char * eomorig, 
               const u_char * comp_dn, 
               char * exp_dn, 
               int length );

Arguments:

msg

A pointer to the beginning of the message that contains the compressed name.

eomorig

A pointer to the first location after the message.

comp_dn

The compressed name that you want to expand.

exp_dn

A buffer where the function can store the expanded name.

length

The length of the array specified by exp_dn.

Library:

libsocket

Use the -l socket option to qcc to link against this library.

Description:

The dn_expand() function is a low-level routine used by res_query() to expand the compressed domain name, comp_dn, to a full domain name.

The compressed name is contained in a query or reply message.

Returns:

The size of the compressed domain name (not the expanded name), in bytes, or -1 if an error occurs.

Classification:

Unix

See also:

dn_comp(), gethostbyname(), res_init(), res_mkquery(), res_query(), res_search(), res_send()

/etc/resolv.conf, hostname in the Utilities Reference

Based on RFC 974, RFC 1032, RFC 1033, RFC 1034, RFC 1035