schemelib/examples/udp_server.scm

93 lines
2.4 KiB
Scheme

(load "../bindings/libc.scm")
(define (check-err ret msg)
(cond
((< ret 0)
(perror msg)
(raise msg))
(#t ret)))
(define (alloc size fx)
(let ([v (foreign-alloc size)])
(fx v)
(foreign-free v)))
(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 (sin_family) addr (domain->int 'AF_INET))
(ftype-set! sockaddr_in (sin_port) addr (htons port))
(check-err
(inet_pton
'AF_INET
host
(ftype-pointer-address
(ftype-&ref sockaddr_in (sin_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)
(let*
([bufsize 1500] [straddrsize 255]
[buf (foreign-alloc bufsize)]
[straddr (make-ftype-pointer
char
(foreign-alloc straddrsize))]
[addrlen (make-ftype-pointer
int
(foreign-alloc (ftype-sizeof int)))]
[addr (make-ftype-pointer
sockaddr_in
(foreign-alloc (ftype-sizeof sockaddr_in)))]
[nread (recvfrom sock buf bufsize 'MSG_DEFAULT addr addrlen)])
; FIXME add a loop and check fx output to know if we continue
(fx
(inet_ntop
'AF_INET
(ftype-pointer-address
(ftype-&ref sockaddr_in (sin_addr) addr))
straddr
straddrsize)
(ntohs (ftype-ref sockaddr_in (sin_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 "0.0.0.0" 1337)
(udpsock-readblock
sock
(lambda (host port buf size)
))))