DNS Resolver library (libgetdns, -lgetdns)
getdns_general (getdns_context *context,
const char *name,
getdns_general_sync (getdns_context *context,
const char *name,
The getdns_general(3) and getdns_general_sync functions provide public entry points into the getdns API library to retrieve any valid responses to a query from the DNS (note that other namespaces in the context are not used). Most typical use cases for applications are probably satisifed via calls to getdns_address(3) which would replace getaddrinfo(3).
context A pointer to the previsouly created DNS context that is to be used with this DNS request. see getdns_context (3)
name The ASCII-based domain name looked up as a string. This can also be an IPv4 or IPv6 address for request types that take addresses instead of domain names, such as PTR. The values here follow the rules in section 2.1 of RFC 4343 to allow non-ASCII octets and special characters in labels.
request_type Specifies the RRtype for the query; the RRtype numbers are listed in the IANA registry. For example, to get the NS records, request_type would be 2. The API also has defined macros for most of the RRtypes by name; the definition names all start with "GETDNS_RRTYPE_". For example, to get the NS records, you can also set the request_type to GETDNS_RRTYPE_NS.
extensions extensions for this request, NULL if no extensions, see libgetnds (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).
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 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)
This is a list of the most common request types, a full list of request types in more detail is available at http://www.iana.org/assignments/dns-parameters/dns-parameters.xml
Certificate Authority Authorization
Canonical name for an alias
DNSSEC lookaside validation
Mailbox or mail list information
Authoritative name server
Next secure record
Next secure record (hashed)
Domain name pointer
Signature for a record set
Marks the start of a zone of authority
DNSSEC trust authorities
libgetdns(3), getdns_address(3), getdns_context(3), getdns_free_sync_request_memory(3), getdns_hostname(3), getdns_service(3),
getdns_address(3), getdns_cancel_callback(3), getdns_context(3), getdns_context_set_append_name(3), getdns_dict_get(3), getdns_dict_set(3), getdns_hostname(3), getdns_list_get(3), getdns_list_set(3), getdns_service(3), libgetdns(3).
The man page getdns_general_sync(3) is an alias of getdns_general(3).