package dns-stub
Library
Module
Module type
Parameter
Class
Class type
The type for TCP errors.
The type for TCP write errors.
type ipaddr = Ipaddr.t
The type for IP address representations.
Disconnect from the TCP layer. While this might take some time to complete, it can never result in an error.
include Mirage_flow.S
with type flow := flow
and type error := error
and type write_error := write_error
val pp_write_error : write_error Fmt.t
pp_write_error
is the pretty-printer for write errors.
read flow
blocks until some data is available and returns a fresh buffer containing it.
The returned buffer will be of a size convenient to the flow implementation, but will always have at least 1 byte.
When read
returns `Eof
or an error, close
(or shutdown
) should be called on the flow
by the client. Once read
returned `Eof
or an error, no subsequent read
call will be successful.
val write : flow -> Cstruct.t -> (unit, write_error) result Lwt.t
write flow buffer
writes a buffer to the flow. There is no indication when the buffer has actually been sent and, therefore, it must not be reused. The contents may be transmitted in separate packets, depending on the underlying transport. The result Ok ()
indicates success, Error `Closed
indicates that the connection is now closed and therefore the data could not be written. Other errors are possible.
The promise is resolved when the buffer has been accepted by the implementation (if a partial write occured, write
will wait until the remainder of the buffer has been accepted by the implementation).
If write
returns an error, close
(or shutdown
) should be called on the flow
by the client. Once write
returned an error, no subsequent write
or writev
call will be successful.
val writev : flow -> Cstruct.t list -> (unit, write_error) result Lwt.t
writev flow buffers
writes a sequence of buffers to the flow. There is no indication when the buffers have actually been sent and, therefore, they must not be reused. The result Ok ()
indicates success, Error `Closed
indicates that the connection is now closed and therefore the data could not be written. Other errors are possible.
The promise is resolved when the buffers have been accepted by the implementation (if a partial write occured, writev
will wait until all buffers have been accepted by the implementation).
If writev
returns an error, close
(or shutdown
) should be called on the flow
by the client. Once writev
returned an error, no subsequent writev
or write
call will be successful.
shutdown flow mode
shuts down the flow
for the specific mode
: A flow which is shutdown `read
(or `read_write
) will never be read
again (subsequent calls will return `Eof
); a flow which is shutdown `write
(or `read_write
) flushes all pending writes and signals the remote endpoint there won't be any future write
or writev
calls (subsequent calls will return `Closed
). E.g. in TCP, the signalling is done by sending a segment with the FIN flag.
If this flow
is layered upon another flow'
(e.g. TLS over TCP), and the internal state after shutdown
is `Closed
, close
on the underlying flow'
is executed.
close flow
terminates the flow
and frees all associated data. Any subsequent read
or write
will return an error. A subsequent close
will not do anything (esp. not raising an exception), but it may log an error.
If this flow
is layered upon another flow'
(e.g. TLS over TCP), close
on the underlying flow'
is executed.
Get the destination IP address and destination port that a flow is currently connected to.
Get the source IP address and source port that a flow is currently connected to.
val write_nodelay : flow -> Cstruct.t -> (unit, write_error) result Lwt.t
write_nodelay flow buffer
writes the contents of buffer
to the flow. The thread blocks until all data has been successfully transmitted to the remote endpoint. Buffering within the layer 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 -> Cstruct.t list -> (unit, write_error) result Lwt.t
writev_nodelay flow buffers
writes the contents of buffers
to the flow. The thread blocks until all data has been successfully transmitted to the remote endpoint. Buffering within the layer 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 create_connection :
?keepalive:Tcpip.Tcp.Keepalive.t ->
t ->
(ipaddr * int) ->
(flow, error) result Lwt.t
create_connection ~keepalive t (addr,port)
opens a TCP connection to the specified endpoint.
If the optional argument ?keepalive
is provided then TCP keep-alive messages will be sent to the server when the connection is idle. If no responses are received then eventually the connection will be disconnected: read
will return Ok `Eof
and write will return Error `Closed
val listen :
t ->
port:int ->
?keepalive:Tcpip.Tcp.Keepalive.t ->
(flow -> unit Lwt.t) ->
unit
listen t ~port ~keepalive callback
listens on port
. The callback
is executed for each flow that was established. If keepalive
is provided, this configuration will be applied before calling callback
.
val unlisten : t -> port:int -> unit
unlisten t ~port
stops any listener on port
.