dn_expand(3)dn_expand(3)NAMEdn_expand - Expand a compressed domain name
SYNOPSIS
#include <sys/types.h> #include <netinet/in.h> #include
<arpa/nameser.h> #include <resolv.h>
int dn_expand(
const u_char *message_ptr,
const u_char *end_of_message,
const u_char *compressed_name,
char *expanded_name,
int length );
LIBRARY
Standard C Library (libc)
PARAMETERS
Specifies a pointer to the beginning of a message. Points to the end
of the original message that contains the compressed domain name.
Specifies a pointer to a compressed domain name. Specifies a pointer
to a buffer that holds the resulting expanded domain name. Specifies
the size of the buffer pointed to by the expanded_name parameter.
DESCRIPTION
The dn_expand() function expands a compressed domain name to a full
domain name, converting the expanded names to uppercase.
The dn_expand() function is one of a set of subroutines that form the
resolver, a set of functions that resolves domain names. Global infor‐
mation that is used by the resolver functions is kept in the _res data
structure. The /include/resolv.h file contains the _res structure defi‐
nition.
RETURN VALUES
Upon successful completion, the dn_expand() function returns the size
of the compressed domain name. Otherwise, a value of -1 is returned.
ERRORS
If an error occurs during a resolver operation, the h_errno external
variable is set. Error code values and reasons are defined in
<netdb.h>.
FILES
Defines name server and domain name constants, structures, and values.
SEE ALSO
Functions: dn_comp(3), dn_find(3), dn_skipname(3), putshort(3), put‐
long(3), res_init(3), res_mkquery(3), res_query(3), res_search(3),
res_send(3), _getshort(3), _getlong(3).
dn_expand(3)