getdns_hostname(3) getdns getdns_hostname(3)NAME
getdns_hostname, getdns_hostname_sync-- get hostname by address
LIBRARY
DNS Resolver library (libgetdns, -lgetdns)
SYNOPSIS
#include <getdns.h>
getdns_return_t
getdns_hostname (getdns_context *context,
getdns_dict *address,
getdns_dict *extensions,
void *userarg,
getdns_transaction_t *transaction_id,
getdns_callback_t callbackfn)
getdns_return_t
getdns_hostname_sync (getdns_context *context,
getdns_dict *address,
getdns_dict *extensions,
getdns_dict **response)
DESCRIPTION
The getdns_hostname(3) and getdns_hostname_sync functions provide pub‐
lic entry points into the getdns API library to retrieve the host name
given an address.
context A pointer to the previously created DNS context that is to be
used with this DNS request. see getdns_context (3)
address a getdns_dict structure containing two names: address_type
(whose value is bindata and is either "IPv4" or "IPv6") and
address_data whose value is bindata
extensions extensions for this request, NULL if no extensions, see
libgetdns (3) for a detailed description of extensions
userarg returned to the callback function untouched, can be NULL
transaction_id populated by the API and used to identify the callback
(for example to getdns_cancel_callback), can be NULL, set to 0 if
the function fails
callbackfn non-NULL pointer to a callback function defined by the
application, typically used to process the response. Only the asyn‐
chronous signature accepts a callback function, the synchronous sig‐
nature does not include a callback. See libgetdns (3) for a more
detailed discussion of callback functions.
response A getdns_dict type is returned in response and always contains
at least three names: replies_full (a list containing the DNS
response as binary data), replies_tree (a list containing the parsed
DNS response data) and status (an int). The storage associated with
this must be freed by a call to getdns_free_sync_request_memory (3).
RETURN VALUES
Upon successful completion the functions return GETDNS_RETURN_GOOD ,
otherwise the following error values are returned:
GETDNS_RETURN_BAD_CONTEXT if the context pointer is invalid or the con‐
text has internal deficiencies
GETDNS_RETURN_BAD_DOMAIN_NAME if the domain name passed to the function
is invalid
GETDNS_RETURN_EXTENSION_MISFORMAT if the data type specified in one or
more of the extensions does not match the specifications
GETDNS_RETURN_GENERIC_ERROR if some problem was encountered in the
function not addressed by one of the more specific return codes
GETDNS_RETURN_INVALID PARAMETER if one or more parameters has an
invalid value
GETDNS_RETURN_MEMORY_ERROR if unable to allocate the memory required
GETDNS_RETURN_NO_SUCH_EXTENSION if one or more of the strings specified
in the extensions are not valid
The values of status included in the response parameter are:
GETDNS_RESPSTATUS_GOOD if at least one response was returned
GETDNS_RESPSTATUS_NO_NAME if queries for the name yielded all negative
responses
GETDNS_RESPSTATUS_ALL_TIMEOUT if all queries for the name timed out
GETDNS_RESPSTATUS_NO_SECURE_ANSWERS if only secure replies accepted
(per context) and at least one response was received but no DNS
responses were secure through DNSSEC
For a more detailed explanation of the response object see libgetdns
(3)
EXAMPLES
TBD
FILES
/etc/hosts
/etc/resolv.conf
SEE ALSOlibgetdns(3), getdns_context(3), getdns_free_sync_request_memory(3),
getdns_general(3), getdns_address(3), getdns_service(3),
getdns 0.9.0 December 2015 getdns_hostname(3)
