getdns/doc/getdns_service.3.in

.\" The "BSD-New" License
.\" 
.\" Copyright (c) 2013, NLNet Labs, Versign, Inc.
.\" All rights reserved.
.\" 
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions are met:
.\" * Redistributions of source code must retain the above copyright
.\"   notice, this list of conditions and the following disclaimer.
.\" * Redistributions in binary form must reproduce the above copyright
.\"   notice, this list of conditions and the following disclaimer in the
.\"   documentation and/or other materials provided with the distribution.
.\" * Neither the name of the <organization> nor the
.\"   names of its contributors may be used to endorse or promote products
.\"   derived from this software without specific prior written permission.
.\" 
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
.\" DISCLAIMED. IN NO EVENT SHALL Verisign, Inc. BE LIABLE FOR ANY
.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
.\" SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\" 

.TH getdns_service 3 "@date@" "getdns @version@" getdns
.SH NAME
.B getdns_service, 
.B getdns_service_sync

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

.SH SYNOPSIS
#include <getdns.h>

getdns_return_t 
.br
.B getdns_service
(getdns_context_t context,
.RS 3
const char *name,
.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_service_sync
(getdns_context_t context,
.RS 3
const char *name,
.br
struct getdns_dict *extensions,
.br
uint32_t *response_length,
.br
struct getdns_dict **response)
.RE

.SH DESCRIPTION

.LP
The getdns_service (3) and getdns_service_sync functions provide public entry points into the getdns API library to retrieve the SRV information given a name.

.HP 3
.I context

see getdns_context (3)

.HP 3
.I name

the service name to resolve

.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_hostname (3),
.BR getdns_hostname_sync (3),
.BR getdns_address (3),
.BR getdns_address_sync (3).