LIBRARY
DNS Resolver library (libgetdns, -lgetdns)
SYNOPSIS
#include <getdns.h>
getdns_return_t
getdns_address
(getdns_context *context,
-
const char *name,
getdns_dict *extensions,
void *userarg,
getdns_transaction_t *transaction_id,
getdns_callback_t callbackfn)
getdns_return_t
getdns_address_sync
(getdns_context *context,
-
const char *name,
getdns_dict *extensions,
getdns_dict **response)
DESCRIPTION
The getdns_address(3) and getdns_address_sync functions provide public entry points into the getdns API library to retrieve the address given a host name. They always returns both IPv4 and IPv6 addresses. This function will use all of the namespaces from the context (to better emulate getaddrinfo (3)).
- context
- A pointer to the previously created DNS context that is to be used with this DNS request. see getdns_context (3)
- name
- the host name to resolve to an address (note that an IP address is considered invalid)
- 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 asynchronous signature accepts a
callback function, the synchronous signature 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
GETDNS_RETURN_BAD_CONTEXT if the context pointer is invalid or the context 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