/**
* @fileChunkSize library/sockets.yap
*/
:- module(yap_sockets,
[ ip_socket/2, % +Domain, -Socket
ip_socket/4, % +Domain, +Type, +Protocol, -Socket
socket_close/1, % +Socket
socket_bind/2, % +Socket, 'AF_INET'(+Host,+Port)
tcp_socket_connect/3, % +Socket, 'AF_INET'(+Host,+Port), -Stream
socket_listen/2, % +Socket, +Length
socket_accept/2, % +Socket, -Stream
socket_accept/3, % +Socket, -Client, -Stream
% socket_select/5, % +TermsSockets, -NewTermsStreams,
% +TimeOut, +Streams, -ReadStreams
current_host/1, % ?HostName
hostname_address/2 % ?HostName, ?HostAddress
]).
:- use_module(library(socket)).
:- use_module(library(error)).
:- use_module(library(apply)).
/** uses SWI code
@aaddtogroup SICStus compatible socket library
@ingroup builtins
YAP includes a SICStus Prolog compatible socket interface. In YAP-6.3
this uses the `clib` package to emulate the old low level interface that
provides direct access to the major socket system calls. These calls
can be used both to open a new connection in the network or connect to
a networked server. Socket connections are described as read/write
streams, and standard Input/Output built-ins can be used to write on or read
from sockets. The following calls are available:
@tbd Our implementation does not support AF_UNIX sockets.
@tbd Implement socket_select/5
@see http://www.sics.se/sicstus/docs/3.7.1/html/sicstus_28.html
*/
/** @pred current_host(? _HOSTNAME_)
Unify _HOSTNAME_ with an atom representing the fully qualified
hostname for the current host. Also succeeds if _HOSTNAME_ is bound
to the unqualified hostname.
*/
/** @pred hostname_address(? _HOSTNAME_,? _IP_ADDRESS_)
_HOSTNAME_ is an host name and _IP_ADDRESS_ its IP
address in number and dots notation.
*/
/** @pred socket_accept(+ _SOCKET_, - _CLIENT_, - _STREAM_)
Interface to system call `accept`, used for servers to wait for
connections at socket _SOCKET_. The stream descriptor _STREAM_
represents the resulting connection. If the socket belongs to the
domain `AF_INET`, _CLIENT_ unifies with an atom containing
the IP address for the client in numbers and dots notation.
*/
/** @pred socket_accept(+ _SOCKET_, - _STREAM_)
Accept a connection but do not return client information.
*/
/** @pred socket_bind(+ _SOCKET_, ? _PORT_)
Interface to system call `bind`, as used for servers: bind socket
to a port. Port information depends on the domain:
+ 'AF_UNIX'(+ _FILENAME_) (unsupported)
+ 'AF_FILE'(+ _FILENAME_)
use file name _FILENAME_ for UNIX or local sockets.
+ 'AF_INET'(? _HOST_,?PORT)
If _HOST_ is bound to an atom, bind to host _HOST_, otherwise
if unbound bind to local host ( _HOST_ remains unbound). If port
_PORT_ is bound to an integer, try to bind to the corresponding
port. If variable _PORT_ is unbound allow operating systems to
choose a port number, which is unified with _PORT_.
*/
/** @pred socket_close(+ _SOCKET_)
Close socket _SOCKET_. Note that sockets used in
`socket_connect` (that is, client sockets) should not be closed with
`socket_close`, as they will be automatically closed when the
corresponding stream is closed with close/1 or `close/2`.
*/
/** @pred socket_listen(+ _SOCKET_, + _LENGTH_)
Interface to system call `listen`, used for servers to indicate
willingness to wait for connections at socket _SOCKET_. The
integer _LENGTH_ gives the queue limit for incoming connections,
and should be limited to `5` for portable applications. The socket
must be of type `SOCK_STREAM` or `SOCK_SEQPACKET`.
*/
%socket(+@var{DOMAIN},+@var{TYPE},+@var{PROTOCOL},-@var{SOCKET})
ip_socket(Domain, 'SOCK_DGRAM', Protocol, SOCKET) :-
must_be(oneof(['AF_INET']), Domain),
must_be(oneof([0]), Protocol),
udp_socket(SOCKET),
assert(yap_socket(udp, SOCKET)).
ip_socket(Domain, 'SOCK_STREAM', Protocol, SOCKET) :-
must_be(oneof(['AF_INET']), Domain),
must_be(oneof([0]), Protocol),
tcp_socket(SOCKET),
assert(yap_socket(tcp, SOCKET)).
ip_socket(Domain, SOCK) :-
socket(Domain, 'SOCK_STREAM', 0, SOCK).
socket_close(Socket) :-
retract(yap_socket(udp, Socket)), !.
socket_close(Socket) :-
retract(yap_socket(tcp, Socket)), !,
tcp_close_socket(Socket).
socket_bind(Socket, 'AF_INET'(Host,Port)) :-
( Address = 'AF_INET'(Host, Port)
-> true
; type_error(socket_address, Address)
),
( var(Host)
-> gethostname(Host)
; true % Warning?
),
tcp_bind(Socket, Port).
tcp_socket_connect(Socket, Address, StreamPair) :-
( Address = 'AF_INET'(Host, Port)
-> true
; type_error(socket_address, Address)
),
tcp_connect(Socket, Host:Port),
tcp_open_socket(Socket, Read, Write),
stream_pair(StreamPair, Read, Write).
socket_listen(SOCKET, BACKLOG) :-
tcp_listen(SOCKET, BACKLOG).
socket_accept(Socket, Client, StreamPair) :-
tcp_accept(Socket, Socket2, Peer),
peer_to_client(Peer, Client),
tcp_open_socket(Socket2, Read, Write),
stream_pair(StreamPair, Read, Write).
/** @pred socket_buffering(+ _SOCKET_, - _MODE_, - _OLD_, + _NEW_)
Set buffering for _SOCKET_ in `read` or `write`
_MODE_. _OLD_ is unified with the previous status, and _NEW_
receives the new status which may be one of `unbuf` or
`fullbuf`.
*/
socket_buffering(STREAM, _, CUR, NEW) :-
stream_property(STREAM, buffer(Prop) ),
translate_buffer(Prop, CUR),
translate_buffer(NProp, NEW),
stream_property(STREAM, buffer(NProp) ).
translate_buffer(false, unbuf).
translate_buffer(full, fullbuf).
current_host(Host) :-
gethostname(Host).
hostname_address(Host, Address) :-
nonvar(Host), !,
tcp_host_to_address(Host, IP),
peer_to_client(IP, Address).
peer_to_client(ip(A,B,C,D), Client) :-
Parts = [A,B,C,D],
ground(Parts), !,
atomic_list_concat(Parts, '.', Client).
peer_to_client(ip(A,B,C,D), Client) :-
atomic_list_concat(Parts, '.', Client),
maplist(atom_number, Parts, Numbers),
Numbers = [A,B,C,D].
/** @pred socket_select(+ _SOCKETS_, - _NEWSTREAMS_, + _TIMEOUT_, + _STREAMS_, - _READSTREAMS_) [unsupported in YAP-6.3]
Interface to system call `select`, used for servers to wait for
connection requests or for data at sockets. The variable
_SOCKETS_ is a list of form _KEY-SOCKET_, where _KEY_ is
an user-defined identifier and _SOCKET_ is a socket descriptor. The
variable _TIMEOUT_ is either `off`, indicating execution will
wait until something is available, or of the form _SEC-USEC_, where
_SEC_ and _USEC_ give the seconds and microseconds before
socket_select/5 returns. The variable _SOCKETS_ is a list of
form _KEY-STREAM_, where _KEY_ is an user-defined identifier
and _STREAM_ is a stream descriptor
Execution of socket_select/5 unifies _READSTREAMS_ from
_STREAMS_ with readable data, and _NEWSTREAMS_ with a list of
the form _KEY-STREAM_, where _KEY_ was the key for a socket
with pending data, and _STREAM_ the stream descriptor resulting
from accepting the connection.
*/
socket_select(_,_,_,_,_) :-
format( user_error, "Unsupported in this version, please use wait_for_input/3~n", []).
/**
@}
*/