mirage-protocols 2.0.0 · OCaml Package

An Internet Protocol (IP) stack reassembles IP fragments into packets, removes the IP header, and on the sending side fragments overlong payload and inserts IP headers.

type error = private [>

| Ip.error

]

The type for IP errors.

val pp_error : error Fmt.t

pp_error is the pretty-printer for errors.

type buffer

The type for memory buffers.

type ipaddr

The type for IP addresses.

include Mirage_device.S

type +'a io

The type for potentially blocking I/O operation

type t

The type representing the internal state of the device

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 = src:ipaddr -> dst:ipaddr -> buffer -> unit io

An input continuation used by the parsing functions to pass on an input packet down the stack.

callback ~src ~dst buf will be called with src and dst containing the source and destination IP address respectively, and buf will be a buffer pointing at the start of the IP payload.

val input : 
  t ->
  tcp:callback ->
  udp:callback ->
  default:(proto:int -> callback) ->
  buffer ->
  unit io

input ~tcp ~udp ~default ip buf demultiplexes an incoming buffer that contains an IP frame. It examines the protocol header and passes the result onto either the tcp or udp function, or the default function for unknown IP protocols.

val write : 
  t ->
  ?fragment:bool ->
  ?ttl:int ->
  ?src:ipaddr ->
  ipaddr ->
  Ip.proto ->
  ?size:int ->
  (buffer -> int) ->
  buffer list ->
  (unit, error) result io

write t ~fragment ~ttl ~src dst proto ~size headerf payload allocates a buffer, writes the IP header, and calls the headerf function. This may write to the provided buffer of size (default 0). If size + ip header exceeds the maximum transfer unit, an error is returned. The payload is appended. The optional fragment argument defaults to true, in which case multiple IP-fragmented frames are sent if the payload is too big for a single frame. When it is false, the don't fragment bit is set and if the payload and header would exceed the maximum transfer unit, an error is returned.

val pseudoheader : t -> ?src:ipaddr -> ipaddr -> Ip.proto -> int -> buffer

pseudoheader t ~src dst proto len gives a pseudoheader suitable for use in TCP or UDP checksum calculation based on t.

val src : t -> dst:ipaddr -> ipaddr

src ip ~dst is the source address to be used to send a packet to dst. In the case of IPv4, this will always return the same IP, which is the only one set.

val set_ip : t -> ipaddr -> unit io

Set the IP address associated with this interface. For IPv4, currently only supports a single IPv4 address, and aliases will be added in a future revision.

val get_ip : t -> ipaddr list

Get the IP addresses associated with this interface. For IPv4, only * one IP address can be set at a time, so the list will always be of * length 1 (and may be the default value, 0.0.0.0).

type uipaddr

The type for universal IP addresses. It supports all the possible versions.

val to_uipaddr : ipaddr -> uipaddr

Convert an IP address with a specific version (eg. V4) into a universal IP address.

val of_uipaddr : uipaddr -> ipaddr option

Project a universal IP address into the version supported by the current implementation. Return None if there is a version mismatch.

val mtu : t -> int

mtu ip is the Maximum Transmission Unit of the ip i.e. the maximum size of the payload, not including the IP header.

package mirage-protocols