getdns/doc/getdns_hostname.3.in

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.TH getdns_hostname 3 "@date@" "getdns @version@" getdns
.SH NAME
.B getdns_hostname, 
.B getdns_hostname_sync

.SH LIBRARY
DNS Resolver library (libgetdns, -lgetdns)

.SH SYNOPSIS
#include <getdns.h>

getdns_return_t 
.br
.B getdns_hostname
(getdns_context_t context,
.RS 3
struct getdns_dict *address,
.br
struct getdns_dict *extensions,
.br
void *userarg,
.br
getdns_transaction_t *transaction_id,
.br
getdns_callback_t callbackfn)
.RE

getdns_return_t 
.br
.B getdns_hostname_sync
(getdns_context_t context,
.RS 3
struct getdns_dict *address,
.br
struct getdns_dict *extensions,
.br
uint32_t *response_length,
.br
struct getdns_dict **response)
.RE

.SH DESCRIPTION

.LP
The getdns_hostname(3) and getdns_hostname_sync functions provide public entry points into the getdns API library to retrieve the host name given an address.

.HP 3
.I context

see getdns_context (3)

.HP 3
.I 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

.HP 3
.I extensions

extensions for this request, NULL if no extensions, see libgetdns (3) for a detailed description of extensions

.HP 3
.I userarg

returned to the callback function untouched, can be NULL

.HP 3
.I 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

.HP 3
.I callbackfn

pointer to a callback function defined by the application, typically used to process the response, may not be NULL. Only the asynchronous signature accepts a callback function, the synchronous signature does not include a callback.

.HP 3
.I response_length

The synchronous entry point includes this argument, the response length is placed at the address pointed to by response_length.

.HP 3
.I 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).

.HP
.SH "RETURN VALUES"

Upon successful completion the functions return
.B GETDNS_RETURN_GOOD
, otherwise the following error values are returned:

.LP
.B GETDNS_RETURN_BAD_CONTEXT 
if the context pointer is invalid
.LP
.B GETDNS_RETURN_BAD_DOMAIN_NAME
if the domain name passed to the function is invalid
.LP
.B GETDNS_RETURN_EXTENSION_MISFORMAT
if the data type specified in one or more of the extensions does not match the specifications
.LP
.B GETDNS_RETURN_NO_SUCH_EXTENSION
if one or more of the strings specified in the extensions are not valid

The values of status in the response include:

.LP
.B GETDNS_RESPSTATUS_GOOD
At least one response was returned
.LP
.B GETDNS_RESPSTATUS_NO_NAME
Queries for the name yielded all negative responses
.LP
.B GETDNS_RESPSTATUS_ALL_TIMEOUT
All queries for the name timed out
.LP
.B GETDNS_RESPSTATUS_NO_SECURE_ANSWERS
only secure replies accepted (per context), at least one response was received but no DNS responses were secure through DNSSEC

.LP
For a more detailed explanation of the response object see
.I libgetdns
(3)

.SH EXAMPLES

TBD

.SH FILES
.br
/etc/hosts
.br
/etc/resolv.conf

.SH SEE ALSO
.BR libgetdns (3),
.BR getdns_general (3),
.BR getdns_general_sync (3),
.BR getdns_address (3),
.BR getdns_address_sync (3),
.BR getdns_service (3),
.BR getdns_service_sync (3).