;; Copyright (c) 2010-2012 Alex Shinn. All rights reserved.
;; BSD-style license: http://synthcode.com/license.txt
;;> \procedure{(make-address-info family socktype proto [hints])}
(define (make-address-info family socktype proto . o)
(%make-address-info family socktype proto (if (pair? o) (car o) 0)))
;;> \procedure{(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/unspecified
socket-type/stream
ip-proto/ip
ai/passive))))
;;> 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 three
;;> values on success - the socket, an input port, and an
;;> output port - or \scheme{#f} on failure.
(define (open-net-io host service . o)
(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 (not (fileno? 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
(if (not (and (pair? o) (car o)))
(let ((st (bitwise-ior (get-file-descriptor-status sock)
open/non-block)))
(set-file-descriptor-status! sock st))))
(else #f))
(list sock
(open-input-file-descriptor sock #t)
(open-output-file-descriptor sock #t)))))))))
;;> 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 (cadr io) (car (cddr io)))))
(close-input-port (cadr io))
(close-output-port (car (cddr io)))
(close-file-descriptor (car io))
res))))
;;> \procedure{(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
((not sock)
(error "couldn't create socket for: " addrinfo))
((not (set-socket-option! sock level/socket socket-opt/reuseaddr 1))
(close-file-descriptor sock)
(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" sock addrinfo))
((not (listen sock max-connections))
(close-file-descriptor sock)
(error "couldn't listen on socket" sock 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))))
;;> Sends the bytevector \var{bv} to \var{socket} with sendto and
;;> returns the number of bytes sent, or a negative value on error.
;;> If \var{addrinfo} is unspecified, \var{socket} must previously
;;> have had a default address specified with \scheme{connect}.
(define (send socket bv . o)
(apply send/non-blocking socket bv #f o))
;;> Equivalent to \scheme{send} but gives up and returns false if the
;;> packet can't be sent within \var{timeout} seconds.
(define (send/non-blocking socket bv timeout . o)
(let* ((flags (if (pair? o) (car o) 0))
(addrinfo (and (pair? o) (pair? (cdr o)) (cadr o)))
(sockaddr (and addrinfo (address-info-address addrinfo)))
(sockaddr-len (if addrinfo (address-info-address-length addrinfo) 0)))
(%send socket bv flags sockaddr sockaddr-len timeout)))
;;> Recieves data from \var{socket} to fill the bytevector \var{bv} by
;;> calling recvfrom. Returns the number of bytes read, or a negative
;;> value on error. If \var{addrinfo} is unspecified, \var{socket}
;;> must previously have had a default address specified with
;;> \scheme{connect}.
(define (receive! socket bv . o)
(apply receive!/non-blocking socket bv #f o))
;;> Equivalent to \scheme{receive!} but gives up and returns false if
;;> no packets are received within \var{timeout} seconds.
(define (receive!/non-blocking socket bv timeout . o)
(let* ((flags (if (pair? o) (car o) 0))
(addrinfo (and (pair? o) (pair? (cdr o)) (cadr o)))
(sockaddr (and addrinfo (address-info-address addrinfo)))
(sockaddr-len (if addrinfo (address-info-address-length addrinfo) 0)))
(%receive! socket bv flags sockaddr sockaddr-len timeout)))
;;> Shortcut for \scheme{receive}, returning a newly created
;;> bytevector of length \var{n} on success and \scheme{#f} on
;;> failure.
(define (receive socket n . o)
(let* ((bv (make-bytevector n))
(m (apply receive! socket bv o)))
(and (>= m 0)
(subbytes bv 0 m))))
;;> Equivalent to \scheme{receive} but gives up and returns false if
;;> no packets are received within \var{timeout} seconds.
(define (receive/non-blocking socket n timeout . o)
(let* ((bv (make-bytevector n))
(m (apply receive!/non-blocking socket bv timeout o)))
(and (>= m 0)
(subbytes bv 0 m))))