package mirage-qubes

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QubesOS qrexec agent protocol. See: https://www.qubes-os.org/doc/qrexec3/

type t
module Flow : S.FLOW
module Client_flow : sig ... end
type handler = user:string -> string -> Flow.t -> int Lwt.t

A handler gets a command-line and a two-way connection to the requesting client each time the remote client sends a MSG_EXEC_CMDLINE request. The "exit code" from the handler is returned to the client.

type client = [ `Ok of Client_flow.t | `Closed | `Permission_denied | `Error of string ] -> unit Lwt.t

client is a callback for unikernel-initiated qrexec calls. The callback is called exactly once, and is given either a flow if successful, `Closed if the control channel has been closed, `Permission_denied if dom0 says so, or an error.

val connect : domid:int -> unit -> t Lwt.t

connect ~domid () is a qrexec agent to which a client in domid has connected. Internally, it creates a server endpoint and places the endpoint information in XenStore, then waits for a client to connect.

val listen : t -> handler -> unit Lwt.t

listen t handler is a thread that reads incoming requests from t and handles each one asynchronously with handler. The loop ends if the client disconnects.

val qrexec : t -> vm:string -> service:string -> client -> [ `Ok | `Closed ] Lwt.t

qrexec t ~vm ~service ~client initiates a qrexec call to vm's service service, and calls client with the result. If the control channel to dom0 is closed the result is `Closed. Otherwise `Ok is returned. Argument vm must have length less than 32 while service must have length less than 64. Otherwise Invalid_argument is raised.

val disconnect : t -> unit Lwt.t

Close the underlying vchan. This will cause any listening thread to finish.