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|
#!@GUILE@ \
-e main
!#
;;; client.scm -- An example of an RPC call over a SSH tunnel.
;; Copyright (C) 2015 Artyom V. Poptsov <poptsov.artyom@gmail.com>
;;
;; This program is free software: you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation, either version 3 of the
;; License, or (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see
;; <http://www.gnu.org/licenses/>.
;;; Commentary:
;; A demo program that makes an RPC call over a SSH tunnel. For simplicity
;; the program uses ssh-agent for authentication.
;;
;; The basic code for the RPC call is taken from Guile-RPC documentation.
;;; Code:
(use-modules (ice-9 getopt-long)
;; RPC
(rpc rpc)
(rpc xdr)
(rpc xdr types)
;; Guile-SSH
(ssh session)
(ssh auth)
(ssh tunnel))
(define result-type
(make-xdr-struct-type (list xdr-integer ;; `integer_part'
xdr-unsigned-integer))) ;; `decimal_part'
(define invoke-split-number
(make-synchronous-rpc-call 80000 0 ;; program and version
1 ;; procedure number
xdr-double ;; argument type
result-type))
(define (print-help-and-exit)
"Print information about program usage."
(display "\
Usage: rrepl.scm [options] <host>
Connect to a remote REPL (RREPL) using an ssh-agent for authentication.
Options:
--user, -u <user> User name.
--port, -p <port> SSH port number (default: 22)
--help, -h Print this message and exit.
")
(exit))
(define (main args)
"Entry point of the program."
(let* ((options-spec '((user (single-char #\u) (value #t))
(port (single-char #\p) (value #t))
(local-port (single-char #\l) (value #t))
(help (single-char #\h) (value #f))))
(options (getopt-long args options-spec))
(user (option-ref options 'user (getenv "USER")))
(port (option-ref options 'port "22"))
(local-port (option-ref options 'local-port "12345"))
(help-needed? (option-ref options 'help #f))
(args (option-ref options '() #f)))
(and (or help-needed?
(not args)
(null? args))
(print-help-and-exit))
(let ((pid (primitive-fork)))
(if (zero? pid)
;; Make a new SSH session, connect it and authenticate the user.
(let* ((host (car args))
(session (make-session #:user user
#:host host
#:port (string->number port)
#:log-verbosity 'nolog)))
(connect! session)
(userauth-agent! session)
;; Make a new SSH tunnel.
(let ((tunnel (make-tunnel session
#:port (string->number local-port)
;; Guile-RPC server listens on localhost.
#:host "127.0.0.1"
;; Guile-RPC server port.
#:host-port 6666)))
(start-forward tunnel)))
(let ((sock (socket PF_INET SOCK_STREAM 0)))
(dynamic-wind
(const #t)
(lambda ()
(sleep 1)
(connect sock AF_INET (inet-pton AF_INET "127.0.0.1")
(string->number local-port))
;; Make an RPC call using the SSH tunnel.
(display (invoke-split-number 3.14 #x7777 sock))
(newline))
(lambda ()
(close sock)
(kill pid SIGTERM)
(waitpid pid))))))))
;;; client.scm ends here.
|
