GI.Gio.Objects.Resolver

Resolver provides cancellable synchronous and asynchronous DNS resolution, for hostnames (resolverLookupByAddress, resolverLookupByName and their async variants) and SRV (service) records (resolverLookupService).

NetworkAddress and NetworkService provide wrappers around Resolver functionality that also implement SocketConnectable, making it easy to connect to a remote host/service.

Exported types

newtype Resolver

Memory-managed wrapper type.

Constructors

Resolver (ManagedPtr Resolver)

Instances

GObject Resolver

Defined in GI.Gio.Objects.Resolver

Methods

gobjectType :: IO GType

HasParentTypes Resolver

Defined in GI.Gio.Objects.Resolver

type ParentTypes Resolver

Defined in GI.Gio.Objects.Resolver

type ParentTypes Resolver = Object ': ([] :: [Type])

class (GObject o, IsDescendantOf Resolver o) => IsResolver o

Type class for types which can be safely cast to Resolver, for instance with toResolver.

Instances

(GObject o, IsDescendantOf Resolver o) => IsResolver o

Defined in GI.Gio.Objects.Resolver

toResolver :: (MonadIO m, IsResolver o) => o -> m Resolver

Cast to Resolver, for types for which this is known to be safe. For general casts, use castTo.

noResolver :: Maybe Resolver

A convenience alias for Nothing :: Maybe Resolver.

Methods

getDefault

resolverGetDefault

Arguments

:: (HasCallStack, MonadIO m)

=> m Resolver

Returns: the default Resolver.

Gets the default Resolver. You should unref it when you are done with it. Resolver may use its reference count as a hint about how many threads it should allocate for concurrent DNS resolutions.

Since: 2.22

lookupByAddress

resolverLookupByAddress

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsInetAddress b, IsCancellable c)

=> a

resolver: a Resolver

-> b

address: the address to reverse-resolve

-> Maybe c

cancellable: a Cancellable, or Nothing

-> m Text

Returns: a hostname (either ASCII-only, or in ASCII-encoded form), or Nothing on error. (Can throw GError)

Synchronously reverse-resolves address to determine its associated hostname.

If the DNS resolution fails, error (if non-Nothing) will be set to a value from ResolverError.

If cancellable is non-Nothing, it can be used to cancel the operation, in which case error (if non-Nothing) will be set to IOErrorEnumCancelled.

Since: 2.22

lookupByAddressAsync

resolverLookupByAddressAsync

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsInetAddress b, IsCancellable c)

=> a

resolver: a Resolver

-> b

address: the address to reverse-resolve

-> Maybe c

cancellable: a Cancellable, or Nothing

-> Maybe AsyncReadyCallback

callback: callback to call after resolution completes

-> m ()

Begins asynchronously reverse-resolving address to determine its associated hostname, and eventually calls callback, which must call resolverLookupByAddressFinish to get the final result.

Since: 2.22

lookupByAddressFinish

resolverLookupByAddressFinish

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsAsyncResult b)

=> a

resolver: a Resolver

-> b

result: the result passed to your AsyncReadyCallback

-> m Text

Returns: a hostname (either ASCII-only, or in ASCII-encoded form), or Nothing on error. (Can throw GError)

Retrieves the result of a previous call to resolverLookupByAddressAsync.

If the DNS resolution failed, error (if non-Nothing) will be set to a value from ResolverError. If the operation was cancelled, error will be set to IOErrorEnumCancelled.

Since: 2.22

lookupByName

resolverLookupByName

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

hostname: the hostname to look up

-> Maybe b

cancellable: a Cancellable, or Nothing

-> m [InetAddress]

Returns: a non-empty List of InetAddress, or Nothing on error. You must unref each of the addresses and free the list when you are done with it. (You can use g_resolver_free_addresses() to do this.) (Can throw GError)

Synchronously resolves hostname to determine its associated IP address(es). hostname may be an ASCII-only or UTF-8 hostname, or the textual form of an IP address (in which case this just becomes a wrapper around inetAddressNewFromString).

On success, resolverLookupByName will return a non-empty List of InetAddress, sorted in order of preference and guaranteed to not contain duplicates. That is, if using the result to connect to hostname, you should attempt to connect to the first address first, then the second if the first fails, etc. If you are using the result to listen on a socket, it is appropriate to add each result using e.g. socketListenerAddAddress.

If the DNS resolution fails, error (if non-Nothing) will be set to a value from ResolverError and Nothing will be returned.

If cancellable is non-Nothing, it can be used to cancel the operation, in which case error (if non-Nothing) will be set to IOErrorEnumCancelled.

If you are planning to connect to a socket on the resolved IP address, it may be easier to create a NetworkAddress and use its SocketConnectable interface.

Since: 2.22

lookupByNameAsync

resolverLookupByNameAsync

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

hostname: the hostname to look up the address of

-> Maybe b

cancellable: a Cancellable, or Nothing

-> Maybe AsyncReadyCallback

callback: callback to call after resolution completes

-> m ()

Begins asynchronously resolving hostname to determine its associated IP address(es), and eventually calls callback, which must call resolverLookupByNameFinish to get the result. See resolverLookupByName for more details.

Since: 2.22

lookupByNameFinish

resolverLookupByNameFinish

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsAsyncResult b)

=> a

resolver: a Resolver

-> b

result: the result passed to your AsyncReadyCallback

-> m [InetAddress]

Returns: a List of InetAddress, or Nothing on error. See resolverLookupByName for more details. (Can throw GError)

Retrieves the result of a call to resolverLookupByNameAsync.

If the DNS resolution failed, error (if non-Nothing) will be set to a value from ResolverError. If the operation was cancelled, error will be set to IOErrorEnumCancelled.

Since: 2.22

lookupByNameWithFlags

resolverLookupByNameWithFlags

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

hostname: the hostname to look up

-> [ResolverNameLookupFlags]

flags: extra ResolverNameLookupFlags for the lookup

-> Maybe b

cancellable: a Cancellable, or Nothing

-> m [InetAddress]

Returns: a non-empty List of InetAddress, or Nothing on error. You must unref each of the addresses and free the list when you are done with it. (You can use g_resolver_free_addresses() to do this.) (Can throw GError)

This differs from resolverLookupByName in that you can modify the lookup behavior with flags. For example this can be used to limit results with G_RESOLVER_NAME_LOOKUP_FLAGS_IPV4_ONLY.

Since: 2.60

lookupByNameWithFlagsAsync

resolverLookupByNameWithFlagsAsync

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

hostname: the hostname to look up the address of

-> [ResolverNameLookupFlags]

flags: extra ResolverNameLookupFlags for the lookup

-> Maybe b

cancellable: a Cancellable, or Nothing

-> Maybe AsyncReadyCallback

callback: callback to call after resolution completes

-> m ()

Begins asynchronously resolving hostname to determine its associated IP address(es), and eventually calls callback, which must call resolverLookupByNameWithFlagsFinish to get the result. See resolverLookupByName for more details.

Since: 2.60

lookupByNameWithFlagsFinish

resolverLookupByNameWithFlagsFinish

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsAsyncResult b)

=> a

resolver: a Resolver

-> b

result: the result passed to your AsyncReadyCallback

-> m [InetAddress]

Returns: a List of InetAddress, or Nothing on error. See resolverLookupByName for more details. (Can throw GError)

Retrieves the result of a call to resolverLookupByNameWithFlagsAsync.

If the DNS resolution failed, error (if non-Nothing) will be set to a value from ResolverError. If the operation was cancelled, error will be set to IOErrorEnumCancelled.

Since: 2.60

lookupRecords

resolverLookupRecords

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

rrname: the DNS name to lookup the record for

-> ResolverRecordType

recordType: the type of DNS record to lookup

-> Maybe b

cancellable: a Cancellable, or Nothing

-> m [GVariant]

Returns: a non-empty List of GVariant, or Nothing on error. You must free each of the records and the list when you are done with it. (You can use g_list_free_full() with variantUnref to do this.) (Can throw GError)

Synchronously performs a DNS record lookup for the given rrname and returns a list of records as GVariant tuples. See ResolverRecordType for information on what the records contain for each recordType.

If the DNS resolution fails, error (if non-Nothing) will be set to a value from ResolverError and Nothing will be returned.

If cancellable is non-Nothing, it can be used to cancel the operation, in which case error (if non-Nothing) will be set to IOErrorEnumCancelled.

Since: 2.34

lookupRecordsAsync

resolverLookupRecordsAsync

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

rrname: the DNS name to lookup the record for

-> ResolverRecordType

recordType: the type of DNS record to lookup

-> Maybe b

cancellable: a Cancellable, or Nothing

-> Maybe AsyncReadyCallback

callback: callback to call after resolution completes

-> m ()

Begins asynchronously performing a DNS lookup for the given rrname, and eventually calls callback, which must call resolverLookupRecordsFinish to get the final result. See resolverLookupRecords for more details.

Since: 2.34

lookupRecordsFinish

resolverLookupRecordsFinish

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsAsyncResult b)

=> a

resolver: a Resolver

-> b

result: the result passed to your AsyncReadyCallback

-> m [GVariant]

Returns: a non-empty List of GVariant, or Nothing on error. You must free each of the records and the list when you are done with it. (You can use g_list_free_full() with variantUnref to do this.) (Can throw GError)

Retrieves the result of a previous call to resolverLookupRecordsAsync. Returns a non-empty list of records as GVariant tuples. See ResolverRecordType for information on what the records contain.

If the DNS resolution failed, error (if non-Nothing) will be set to a value from ResolverError. If the operation was cancelled, error will be set to IOErrorEnumCancelled.

Since: 2.34

lookupService

resolverLookupService

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

service: the service type to look up (eg, "ldap")

-> Text

protocol: the networking protocol to use for service (eg, "tcp")

-> Text

domain: the DNS domain to look up the service in

-> Maybe b

cancellable: a Cancellable, or Nothing

-> m [SrvTarget]

Returns: a non-empty List of SrvTarget, or Nothing on error. You must free each of the targets and the list when you are done with it. (You can use g_resolver_free_targets() to do this.) (Can throw GError)

Synchronously performs a DNS SRV lookup for the given service and protocol in the given domain and returns an array of SrvTarget. domain may be an ASCII-only or UTF-8 hostname. Note also that the service and protocol arguments do not include the leading underscore that appears in the actual DNS entry.

On success, resolverLookupService will return a non-empty List of SrvTarget, sorted in order of preference. (That is, you should attempt to connect to the first target first, then the second if the first fails, etc.)

If the DNS resolution fails, error (if non-Nothing) will be set to a value from ResolverError and Nothing will be returned.

If cancellable is non-Nothing, it can be used to cancel the operation, in which case error (if non-Nothing) will be set to IOErrorEnumCancelled.

If you are planning to connect to the service, it is usually easier to create a NetworkService and use its SocketConnectable interface.

Since: 2.22

lookupServiceAsync

resolverLookupServiceAsync

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsCancellable b)

=> a

resolver: a Resolver

-> Text

service: the service type to look up (eg, "ldap")

-> Text

protocol: the networking protocol to use for service (eg, "tcp")

-> Text

domain: the DNS domain to look up the service in

-> Maybe b

cancellable: a Cancellable, or Nothing

-> Maybe AsyncReadyCallback

callback: callback to call after resolution completes

-> m ()

Begins asynchronously performing a DNS SRV lookup for the given service and protocol in the given domain, and eventually calls callback, which must call resolverLookupServiceFinish to get the final result. See resolverLookupService for more details.

Since: 2.22

lookupServiceFinish

resolverLookupServiceFinish

Arguments

:: (HasCallStack, MonadIO m, IsResolver a, IsAsyncResult b)

=> a

resolver: a Resolver

-> b

result: the result passed to your AsyncReadyCallback

-> m [SrvTarget]

Returns: a non-empty List of SrvTarget, or Nothing on error. See resolverLookupService for more details. (Can throw GError)

Retrieves the result of a previous call to resolverLookupServiceAsync.

If the DNS resolution failed, error (if non-Nothing) will be set to a value from ResolverError. If the operation was cancelled, error will be set to IOErrorEnumCancelled.

Since: 2.22

setDefault

resolverSetDefault

Arguments

:: (HasCallStack, MonadIO m, IsResolver a)

=> a

resolver: the new default Resolver

-> m ()

Sets resolver to be the application's default resolver (reffing resolver, and unreffing the previous default resolver, if any). Future calls to resolverGetDefault will return this resolver.

This can be used if an application wants to perform any sort of DNS caching or "pinning"; it can implement its own Resolver that calls the original default resolver for DNS operations, and implements its own cache policies on top of that, and then set itself as the default resolver for all later code to use.

Since: 2.22

Signals

reload

type C_ResolverReloadCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type ResolverReloadCallback = IO ()

Emitted when the resolver notices that the system resolver configuration has changed.

afterResolverReload :: (IsResolver a, MonadIO m) => a -> ResolverReloadCallback -> m SignalHandlerId

Connect a signal handler for the “reload” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after resolver #reload callback

genClosure_ResolverReload :: MonadIO m => ResolverReloadCallback -> m (GClosure C_ResolverReloadCallback)

Wrap the callback into a GClosure.

mk_ResolverReloadCallback :: C_ResolverReloadCallback -> IO (FunPtr C_ResolverReloadCallback)

Generate a function pointer callable from C code, from a C_ResolverReloadCallback.

noResolverReloadCallback :: Maybe ResolverReloadCallback

A convenience synonym for Nothing :: Maybe ResolverReloadCallback.

onResolverReload :: (IsResolver a, MonadIO m) => a -> ResolverReloadCallback -> m SignalHandlerId

Connect a signal handler for the “reload” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on resolver #reload callback

wrap_ResolverReloadCallback :: ResolverReloadCallback -> C_ResolverReloadCallback

Wrap a ResolverReloadCallback into a C_ResolverReloadCallback.