mirage-protocols 7.0.0 · OCaml Package

IPv4 layer

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 ipaddr = Ipaddr.V4.t

The type for IP addresses.

val pp_ipaddr : ipaddr Fmt.t

pp_ipaddr is the pretty-printer for IP addresses.

type t

The type representing the internal state of the IP layer.

val disconnect : t -> unit Lwt.t

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

type callback = src:ipaddr -> dst:ipaddr -> Cstruct.t -> unit Lwt.t

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) ->
  Cstruct.t ->
  unit Lwt.t

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 ->
  (Cstruct.t -> int) ->
  Cstruct.t list ->
  (unit, error) Stdlib.result Lwt.t

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 -> Cstruct.t

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 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).

val mtu : t -> dst:ipaddr -> int

mtu ~dst 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