schemelib/examples/udp_server.scm
2020-07-09 17:51:13 +02:00

88 lines
2.6 KiB
Scheme

(load "../bindings/libc.scm")
(load "../bindings/utils.scm")
(define (udpsock-create fx)
(fx
(check-err
(socket 'AF_INET 'SOCK_DGRAM 'IPPROTO_IP)
"Unable to init UDP socket")))
(define (udpsock-reuseaddr sock)
(alloc
(ftype-sizeof int)
(lambda (activation)
(foreign-set! 'int activation 0 1)
(check-err
(setsockopt
sock
'SOL_SOCKET
'SO_REUSEADDR
activation
(ftype-sizeof int))
"Unable to set REUSE ADDRESS"))))
(define (udpsock-bind sock host port)
(alloc
(ftype-sizeof sockaddr_in)
(lambda (raw-addr)
(let ([addr (make-ftype-pointer sockaddr_in raw-addr)])
(ftype-set! sockaddr_in (common family) addr (domain->int 'AF_INET))
(ftype-set! sockaddr_in (port) addr (htons port))
(check-err
(inet_pton
'AF_INET
host
(ftype-pointer-address
(ftype-&ref sockaddr_in (addr) addr)))
"Unable to convert your IP address to binary")
(bind
sock
(ftype-pointer-address addr)
(ftype-sizeof sockaddr_in))))))
(define (udpsock-readblock sock fx)
(letrec*
([bufsize 1500] [straddrsize 255]
[buf (foreign-alloc bufsize)]
[straddr (make-ftype-pointer char
(foreign-alloc straddrsize))]
[addrlen (make-ftype-pointer socklen_t
(foreign-alloc (ftype-sizeof socklen_t)))]
[_ (ftype-set! socklen_t () addrlen (ftype-sizeof sockaddr_in))]
[addr (make-ftype-pointer
sockaddr_in
(foreign-alloc (ftype-sizeof sockaddr_in)))]
[loop (lambda (ifx) (cond ((ifx) (loop ifx)) (#t #t)))])
(loop
(lambda ()
(let ([nread (recvfrom sock buf bufsize 'MSG_DEFAULT addr addrlen)])
(printf "~a~%" (ftype-pointer->sexpr addr))
(fx
(inet_ntop
'AF_INET
(ftype-pointer-address
(ftype-&ref sockaddr_in (addr) addr))
straddr
straddrsize)
(ntohs (ftype-ref sockaddr_in (port) addr))
buf nread))))
(foreign-free (ftype-pointer-address straddr))
(foreign-free (ftype-pointer-address addrlen))
(foreign-free (ftype-pointer-address addr))
(foreign-free buf)))
(udpsock-create
(lambda (sock)
(udpsock-reuseaddr sock)
(udpsock-bind sock "127.0.0.8" 1337)
(udpsock-readblock
sock
(lambda (host port buf size)
(printf
"host: ~a, port: ~a, size: ~a, buf: ~a~%"
host port size
(char*->string
(make-ftype-pointer char buf)))
))))