System.Linux.Netlink

This is the base module for the netlink package. It contains functions and datatype used by every netlink module. All definitions are (supposed to be) generic enough to be used by implementations of more specific netlink interfaces.

Documentation

data Header

Data type for the netlink header

Constructors

Header

Fields

• messageType :: MessageType

  The message type

• messageFlags :: Word16

  The message flags

• messageSeqNum :: Word32

  The sequence message number

• messagePID :: Word32

  The pid of the sending process (0 is from kernel for receiving or "let the kernel set it" for sending)

Instances

Eq Header

Methods

(==) :: Header -> Header -> Bool

(/=) :: Header -> Header -> Bool

Show Header

Methods

showsPrec :: Int -> Header -> ShowS

show :: Header -> String

showList :: [Header] -> ShowS

type Attributes = Map Int ByteString

Type used for netlink attributes

data Packet a

The generic netlink message type

Constructors

Packet

Fields

• packetHeader :: Header

  The netlink message header

• packetCustom :: a

  The datatype for additional static data for the interface

• packetAttributes :: Attributes

  The netlink attributes

ErrorMsg

Fields

• packetHeader :: Header

  The netlink message header

• packetError :: CInt

  The error ID for this error message

• errorPacket :: Packet a

  The offending message

DoneMsg

Fields

• packetHeader :: Header

  The netlink message header

Instances

Show NL80211Packet

Methods

showsPrec :: Int -> NL80211Packet -> ShowS

show :: NL80211Packet -> String

showList :: [NL80211Packet] -> ShowS

Show RoutePacket

Methods

showsPrec :: Int -> RoutePacket -> ShowS

show :: RoutePacket -> String

showList :: [RoutePacket] -> ShowS

Eq a => Eq (Packet a)

Methods

(==) :: Packet a -> Packet a -> Bool

(/=) :: Packet a -> Packet a -> Bool

Show a => Show (Packet a)

Methods

showsPrec :: Int -> Packet a -> ShowS

show :: Packet a -> String

showList :: [Packet a] -> ShowS

Show a => Show (GenlPacket a)

Show Instance for GenlPacket

Methods

showsPrec :: Int -> GenlPacket a -> ShowS

show :: GenlPacket a -> String

showList :: [GenlPacket a] -> ShowS

class Convertable a where

Typeclase used by the system. Basically Storable for Get and Put

getGet Returns a Get function for the convertable.

The MessageType is passed so that the function can parse different data structures based on the message type.

Minimal complete definition

getGet, getPut

Methods

getGet

Arguments

:: MessageType

-> Get a

get a Get function for the static data

getPut

Arguments

:: a

-> Put

get a Put function for the static data

Instances

Convertable NoData

Methods

getGet :: MessageType -> Get NoData

getPut :: NoData -> Put

Convertable GenlHeader

The Convertable instance for GenlHeader

Methods

getGet :: MessageType -> Get GenlHeader

getPut :: GenlHeader -> Put

Convertable Message

Methods

getGet :: MessageType -> Get Message

getPut :: Message -> Put

Convertable a => Convertable (GenlData a)

The Convertable instance for GenlData

Methods

getGet :: MessageType -> Get (GenlData a)

getPut :: GenlData a -> Put

data NoData

Datatype to be used when there is no additional static header

Constructors

NoData

Instances

Eq NoData

Methods

(==) :: NoData -> NoData -> Bool

(/=) :: NoData -> NoData -> Bool

Show NoData

Methods

showsPrec :: Int -> NoData -> ShowS

show :: NoData -> String

showList :: [NoData] -> ShowS

Convertable NoData

Methods

getGet :: MessageType -> Get NoData

getPut :: NoData -> Put

Show (GenlData NoData)

Show instance of GenlData for NoData

Methods

showsPrec :: Int -> GenlData NoData -> ShowS

show :: GenlData NoData -> String

showList :: [GenlData NoData] -> ShowS

data NetlinkSocket

Typesafe wrapper around a CInt (fd)

getPacket

Arguments

:: ByteString

The buffer to read from

-> Get a

The function to read a single message

-> Either String [a]

Either an error message or a list of messages read

Read packets from the buffer

getAttributes :: Get Attributes

Get Attributes

getHeader :: Get (Int, Header)

Get the netlink Header

putHeader

Arguments

:: Int

The length of the message

-> Header

The header itself

-> Put

Put the netlink Header

putAttributes :: Attributes -> Put

Put a Map of Attributes

putPacket :: (Convertable a, Eq a, Show a) => Packet a -> [ByteString]

Put a Packet so it can e sent

getPackets :: (Convertable a, Eq a, Show a) => ByteString -> Either String [Packet a]

Read all Packets from a buffer

The packets may have additional static data defined by the protocol.

makeSocket :: IO NetlinkSocket

Open and return a NetlinkSocket, for legacy reasons this opens a route socket

makeSocketGeneric

Arguments

:: Int

The netlink family to use

-> IO NetlinkSocket

Open a NetlinkSocket. This is the generic function

getNetlinkFd :: NetlinkSocket -> Fd

Get the raw Fd used for netlink communcation (this can be plugged into eventing)

closeSocket :: NetlinkSocket -> IO ()

Close a NetlinkSocket when it is no longer used

joinMulticastGroup

Arguments

:: NetlinkSocket

The socket to join with

-> Word32

The id of the group to join, values of System.Linux.Netlink.Constants.eRTNLGRP_*

-> IO ()

Join a netlink multicast group

leaveMulticastGroup

Arguments

:: NetlinkSocket

The socket to leave

-> Word32

The id of the group to leave, values of System.Linux.Netlink.Constants.eRTNLGRP_*

-> IO ()

Leave a netlink multicast group

query :: (Convertable a, Eq a, Show a) => NetlinkSocket -> Packet a -> IO [Packet a]

Query data over netlink.

This sends a Packet over netlink and returns the answer. This blocks in a safe foregin function until the other side replies.

queryOne :: (Convertable a, Eq a, Show a) => NetlinkSocket -> Packet a -> IO (Packet a)

The same as query but requires the answer to be a single message

recvOne :: (Convertable a, Eq a, Show a) => NetlinkSocket -> IO [Packet a]

Calls recvmsg once and returns all received messages

This should only be used outside of the package when reading multicast messages.

The prototype of this function is unintuitive, but this cannot be avoided without buffering in userspace with the netlink api.

showNLAttrs :: Attributes -> String

Convert generic NLAttrs into a string (# and hexdump)

showAttrs

Arguments

:: (Int -> String)

A function from element id to its name

-> Attributes

The attributes

-> String

A string with Element name and hexdump of element

Helper function to convert attributes into a string

showAttr :: (Int -> String) -> (Int, ByteString) -> String

Helper function to generically show a single attribute

showPacket :: Show a => Packet a -> String

Helperfunction for show instance of Packet and further specializations