tcpip 1.1.6 · OCaml Package

A TCPv4 stack that can send and receive reliable streams using the TCP protocol.

type buffer = Cstruct.t

Abstract type for a memory buffer that may not be page aligned.

type ipv4

Abstract type for an IPv4 stack for this stack to connect to.

type ipv4addr = Ipaddr.V4.t

Abstract type for an IPv4 address representation.

type ipv4input

An input function continuation to pass onto the underlying ipv4 stack. This will normally be a NOOP for a conventional kernel, but a direct implementation will parse the buffer.

type flow

A flow represents the state of a single TCPv4 stream that is connected to an endpoint.

type error = [

| `Unknown of string
(*
an undiagnosed error.
*)
| `Timeout
(*
connection attempt did not get a valid response.
*)
| `Refused
(*
connection attempt was actively refused via an RST.
*)

]

IO operation errors

include V1.DEVICE
  with type error := error
   and type id := ipv4
  with type 'a io = 'a Lwt.t

type 'a io = 'a Lwt.t

A potentially blocking I/O operation

type t

The type representing the internal state of the device

val id : t -> ipv4

Return the identifier that was used to construct this device

val connect : ipv4 -> [ `Error of error | `Ok of t ] io

Connect to the device identified by id

val disconnect : t -> unit io

Disconnect from the device. While this might take some time to complete, it can never result in an error.

type callback = flow -> unit io

Application callback that receives a flow that it can read/write to.

val get_dest : flow -> ipv4addr * int

Get the destination IPv4 address and destination port that a flow is currently connected to.

val read : flow -> [ `Ok of buffer | `Eof | `Error of error ] io

read flow will block until it either successfully reads a segment of data from the current flow, receives an Eof signifying that the connection is now closed, or an Error.

val write : flow -> buffer -> unit io

write flow buffer will block until the contents of buffer are transmitted to the remote endpoint. The contents may be transmitted in separate packets, depending on the underlying transport.

val writev : flow -> buffer list -> unit io

writev flow buffers will block until the contents of buffer list are all successfully transmitted to the remote endpoint.

val write_nodelay : flow -> buffer -> unit io

write_nodelay flow will block until the contents of buffer list are all successfully transmitted to the remote endpoint. Buffering within the stack is minimized in this mode. Note that this API will change in a future revision to be a per-flow attribute instead of a separately exposed function.

val writev_nodelay : flow -> buffer list -> unit io

writev_nodelay flow will block until the contents of buffer list are all successfully transmitted to the remote endpoint. Buffering within the stack is minimized in this mode. Note that this API will change in a future revision to be a per-flow attribute instead of a separately exposed function.

val close : flow -> unit io

close flow will signal to the remote endpoint that the flow is now shutdown. The caller should not perform any writes after this call.

val create_connection : 
  t ->
  (ipv4addr * int) ->
  [ `Ok of flow | `Error of error ] io

create_connection t (addr,port) will open a TCPv4 connection to the specified endpoint.

val input : t -> listeners:(int -> callback option) -> ipv4input

input t listeners defines a mapping of threads that are willing to accept new flows on a given port. If the callback returns None, the input function will return an RST to refuse connections on a port.

package tcpip