Network.Connection

connection-0.2.8: Simple and easy network connections API

License | BSD-style
Maintainer | Vincent Hanquez <vincent@snarc.org>
Stability | experimental
Portability | portable
Safe Haskell | None
Language | Haskell98

Network.Connection

Contents

- Type for a connection
- Exceptions
- Library initialization
- Connection operation
- Sending and receiving data
- TLS related operation

Description

Simple connection abstraction

Synopsis

- data Connection
- connectionID :: Connection -> ConnectionID
- data ConnectionParams = ConnectionParams {
  - connectionHostname :: HostName
  - connectionPort :: PortNumber
  - connectionUseSecure :: Maybe TLSSettings
  - connectionUseSocks :: Maybe ProxySettings
  }
- data TLSSettings
  - = TLSSettingsSimple {
    - settingDisableCertificateValidation :: Bool
    - settingDisableSession :: Bool
    - settingUseServerName :: Bool
    }
  - | TLSSettings ClientParams
- data ProxySettings
  - = SockSettingsSimple HostName PortNumber
  - | SockSettingsEnvironment (Maybe String)
  - | OtherProxy HostName PortNumber
- type SockSettings = ProxySettings
- data LineTooLong = LineTooLong
- data HostNotResolved = HostNotResolved String
- data HostCannotConnect = HostCannotConnect String [IOException]
- initConnectionContext :: IO ConnectionContext
- data ConnectionContext
- connectFromHandle :: ConnectionContext -> Handle -> ConnectionParams -> IO Connection
- connectFromSocket :: ConnectionContext -> Socket -> ConnectionParams -> IO Connection
- connectTo :: ConnectionContext -> ConnectionParams -> IO Connection
- connectionClose :: Connection -> IO ()
- connectionGet :: Connection -> Int -> IO ByteString
- connectionGetExact :: Connection -> Int -> IO ByteString
- connectionGetChunk :: Connection -> IO ByteString
- connectionGetChunk' :: Connection -> (ByteString -> (a, ByteString)) -> IO a
- connectionGetLine :: Int -> Connection -> IO ByteString
- connectionWaitForInput :: Connection -> Int -> IO Bool
- connectionPut :: Connection -> ByteString -> IO ()
- connectionSetSecure :: ConnectionContext -> Connection -> TLSSettings -> IO ()
- connectionIsSecure :: Connection -> IO Bool

# Type for a connection

data Connection #

This opaque type represent a connection to a destination.

connectionID :: Connection -> ConnectionID #

return a simple tuple of the port and hostname that we're connected to.

data ConnectionParams #

Connection Parameters to establish a Connection.

The strict minimum is an hostname and the port.

If you need to establish a TLS connection, you should make sure connectionUseSecure is correctly set.

If you need to connect through a SOCKS, you should make sure connectionUseSocks is correctly set.

Constructors

ConnectionParams |
Fields connectionHostname :: HostName host name to connect to. connectionPort :: PortNumber port number to connect to. connectionUseSecure :: Maybe TLSSettings optional TLS parameters. connectionUseSocks :: Maybe ProxySettings optional Proxy/Socks configuration.

data TLSSettings #

TLS Settings that can be either expressed as simple settings, or as full blown TLS.Params settings.

Unless you need access to parameters that are not accessible through the simple settings, you should use TLSSettingsSimple.

Constructors

TLSSettingsSimple | Simple TLS settings. recommended to use.
Fields settingDisableCertificateValidation :: Bool Disable certificate verification completely, this make TLS/SSL vulnerable to a MITM attack. not recommended to use, but for testing. settingDisableSession :: Bool Disable session management. TLS/SSL connections will always re-established their context. Not Implemented Yet. settingUseServerName :: Bool Use server name extension. Not Implemented Yet.
TLSSettings ClientParams | full blown TLS Settings directly using TLS.Params. for power users.

Instances

Show TLSSettings # |
Methods showsPrec :: Int -> TLSSettings -> ShowS # show :: TLSSettings -> String # showList :: [TLSSettings] -> ShowS #
Default TLSSettings # |
Methods def :: TLSSettings #

data ProxySettings #

Proxy settings for the connection.

OtherProxy handles specific application-level proxies like HTTP proxies.

The simple SOCKS settings is just the hostname and portnumber of the SOCKS proxy server.

That's for now the only settings in the SOCKS package, socks password, or any sort of other authentications is not yet implemented.

Constructors

SockSettingsSimple HostName PortNumber |
SockSettingsEnvironment (Maybe String) |
OtherProxy HostName PortNumber |

type SockSettings = ProxySettings #

# Exceptions

data LineTooLong #

This is the exception raised if we reached the user specified limit for the line in ConnectionGetLine.

Constructors

LineTooLong |

Instances

Show LineTooLong # |
Methods showsPrec :: Int -> LineTooLong -> ShowS # show :: LineTooLong -> String # showList :: [LineTooLong] -> ShowS #
Exception LineTooLong # |
Methods toException :: LineTooLong -> SomeException # fromException :: SomeException -> Maybe LineTooLong # displayException :: LineTooLong -> String #

data HostNotResolved #

Exception raised when there's no resolution for a specific host

Constructors

HostNotResolved String |

Instances

Show HostNotResolved # |
Methods showsPrec :: Int -> HostNotResolved -> ShowS # show :: HostNotResolved -> String # showList :: [HostNotResolved] -> ShowS #
Exception HostNotResolved # |
Methods toException :: HostNotResolved -> SomeException # fromException :: SomeException -> Maybe HostNotResolved # displayException :: HostNotResolved -> String #

data HostCannotConnect #

Exception raised when the connect failed

Constructors

HostCannotConnect String [IOException] |

Instances

Show HostCannotConnect # |
Methods showsPrec :: Int -> HostCannotConnect -> ShowS # show :: HostCannotConnect -> String # showList :: [HostCannotConnect] -> ShowS #
Exception HostCannotConnect # |
Methods toException :: HostCannotConnect -> SomeException # fromException :: SomeException -> Maybe HostCannotConnect # displayException :: HostCannotConnect -> String #

# Library initialization

initConnectionContext :: IO ConnectionContext #

Initialize the library with shared parameters between connection.

data ConnectionContext #

Shared values (certificate store, sessions, ..) between connections

At the moment, this is only strictly needed to shared sessions and certificates when using a TLS enabled connection.

# Connection operation

connectFromHandle :: ConnectionContext -> Handle -> ConnectionParams -> IO Connection #

Use an already established handle to create a connection object.

if the TLS Settings is set, it will do the handshake with the server. The SOCKS settings have no impact here, as the handle is already established

connectFromSocket :: ConnectionContext -> Socket -> ConnectionParams -> IO Connection #

Use an already established handle to create a connection object.

if the TLS Settings is set, it will do the handshake with the server. The SOCKS settings have no impact here, as the handle is already established

connectTo #

Arguments

:: ConnectionContext | The global context of this connection.
-> ConnectionParams | The parameters for this connection (where to connect, and such).
-> IO Connection | The new established connection on success.

connect to a destination using the parameter

connectionClose :: Connection -> IO () #

Close a connection.

# Sending and receiving data

connectionGet :: Connection -> Int -> IO ByteString #

Get some bytes from a connection.

The size argument is just the maximum that could be returned to the user. The call will return as soon as there's data, even if there's less than requested. Hence, it behaves like `hGetSome`.

On end of input, `connectionGet` returns 0, but subsequent calls will throw an `isEOFError` exception.

connectionGetExact :: Connection -> Int -> IO ByteString #

Get exact count of bytes from a connection.

The size argument is the exact amount that must be returned to the user. The call will wait until all data is available. Hence, it behaves like `hGet`.

On end of input, `connectionGetExact` will throw an `isEOFError` exception.

connectionGetChunk :: Connection -> IO ByteString #

Get the next block of data from the connection.

connectionGetChunk' :: Connection -> (ByteString -> (a, ByteString)) -> IO a #

Like `connectionGetChunk`, but return the unused portion to the buffer, where it will be the next chunk read.

connectionGetLine #

Arguments

:: Int | Maximum number of bytes before raising a LineTooLong exception
-> Connection | Connection
-> IO ByteString | The received line with the LF trimmed

Get the next line, using ASCII LF as the line terminator.

This throws an `isEOFError` exception on end of input, and LineTooLong when the number of bytes gathered is over the limit without a line terminator.

The actual line returned can be bigger than the limit specified, provided that the last chunk returned by the underlaying backend contains a LF. In another world only when we need more input and limit is reached that the LineTooLong exception will be raised.

An end of file will be considered as a line terminator too, if line is not empty.

connectionWaitForInput :: Connection -> Int -> IO Bool #

Wait for input to become available on a connection.

As with `hWaitForInput`, the timeout value is given in milliseconds. If the timeout value is less than zero, then `connectionWaitForInput` waits indefinitely.

Unlike `hWaitForInput`, this function does not do any decoding, so it returns true when there is any available input, not just full characters.

connectionPut :: Connection -> ByteString -> IO () #

Put a block of data in the connection.

# TLS related operation

connectionSetSecure :: ConnectionContext -> Connection -> TLSSettings -> IO () #

Activate secure layer using the parameters specified.

This is typically used to negociate a TLS channel on an already establish channel, e.g. supporting a STARTTLS command. it also flush the received buffer to prevent application confusing received data before and after the setSecure call.

If the connection is already using TLS, nothing else happens.

connectionIsSecure :: Connection -> IO Bool #

Returns if the connection is establish securely or not.