chibi-scheme/lib/chibi/net.scm

105 lines
4.3 KiB
Scheme

;; Copyright (c) 2010-2012 Alex Shinn. All rights reserved.
;; BSD-style license: http://synthcode.com/license.txt
;;> @subsubsubsection{@scheme{(get-address-info host service [addrinfo])}}
;;> Create and return a new addrinfo structure for the given host
;;> and service. @var{host} should be a string and @var{service} a
;;> string or integer. The optional @var{addrinfo} defaults to
;;> a TCP/IP stream setting.
(define (get-address-info host service . o)
(%get-address-info host
(if (integer? service) (number->string service) service)
(if (and (pair? o) (car o))
(car o)
(make-address-info address-family/inet
socket-type/stream
ip-proto/tcp))))
;;> Opens a client net connection to @var{host}, a string,
;;> on port @var{service}, which can be a string such as
;;> @scheme{"http"} or an integer. Returns a list of two
;;> values on success - an input port and output port -
;;> or @scheme{#f} on failure.
(define (open-net-io host service)
(let lp ((addr (get-address-info host service)))
(if (not addr)
(error "couldn't find address" host service)
(let ((sock (socket (address-info-family addr)
(address-info-socket-type addr)
(address-info-protocol addr))))
(if (negative? sock)
(lp (address-info-next addr))
(cond
((negative?
(connect sock
(address-info-address addr)
(address-info-address-length addr)))
(lp (address-info-next addr)))
(else
(cond-expand
(threads (set-file-descriptor-flags! sock open/non-block))
(else #f))
(cond-expand
(bidir-ports
(let ((port (open-input-output-file-descriptor sock)))
(list port port)))
(else
(list (open-input-file-descriptor sock)
(open-output-file-descriptor sock)))))))))))
;;> Convenience wrapper around @scheme{open-net-io}, opens
;;> the connection then calls @var{proc} with two arguments,
;;> the input port and the output port connected to the
;;> service, then closes the connection. Returns the result
;;> of @var{proc}. Raises an error if a connection can't
;;> be made.
(define (with-net-io host service proc)
(let ((io (open-net-io host service)))
(if (not (pair? io))
(error "couldn't find address" host service)
(let ((res (proc (car io) (cadr io))))
(close-input-port (car io))
(close-output-port (cadr io))
res))))
;;> @subsubsubsection{@scheme{(make-listener-socket addrinfo [max-conn])}}
;;> Convenience wrapper to call socket, bind and listen to return
;;> a socket suitable for accepting connections on the given
;;> @var{addrinfo}. @var{max-conn} is the maximum number of pending
;;> connections, and defaults to 128. Automatically specifies
;;> @scheme{socket-opt/reuseaddr}.
(define (make-listener-socket addrinfo . o)
(let* ((max-connections (if (pair? o) (car o) 128))
(sock (socket (address-info-family addrinfo)
(address-info-socket-type addrinfo)
(address-info-protocol addrinfo))))
(cond
((negative? sock)
(error "couldn't create socket for: " addrinfo))
((not (set-socket-option! sock level/socket socket-opt/reuseaddr 1))
(error "couldn't set the socket to be reusable" addrinfo))
((not (bind sock
(address-info-address addrinfo)
(address-info-address-length addrinfo)))
(close-file-descriptor sock)
(error "couldn't bind socket for: " addrinfo))
((not (listen sock max-connections))
(close-file-descriptor sock)
(error "couldn't listen on socket for: " addrinfo))
(else
sock))))
;;> Returns the socket option of the given @var{name} for @var{socket}.
;;> @var{socket} should be a file descriptor, level the constant
;;> @scheme{level/socket}, and name one of the constants beginning with
;;> "socket-opt/".
(define (get-socket-option socket level name)
(let ((res (getsockopt socket level name)))
(and (pair? res) (car res))))