/* $Id$ Part of SWI-Prolog Author: Jan Wielemaker E-mail: wielemak@science.uva.nl WWW: http://www.swi-prolog.org Copyright (C): 1985-2005, University of Amsterdam This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA As a special exception, if you link this library with other files, compiled with a Free Software compiler, to produce an executable, this library does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ :- module(xpce_httpd, [ http_current_server/2, % ?:Goal, ?Port http_server/2 % :Goal, :Options ]). :- use_module(library(pce)). :- use_module(http_header). :- use_module(library(debug)). :- use_module(http_wrapper). :- use_module(library(lists)). :- meta_predicate http_server(:, ?), http_server(:, ?, +). % @http_servers: keep track of them and avoid the servers being % garbage collected. :- pce_global(@http_servers, new(chain)). %:- debug(connection). http_current_server(Goal, Port) :- object(@open_sockets), chain_list(@open_sockets, Sockets), member(Socket, Sockets), send(Socket, instance_of, interactive_httpd), get(Socket, goal, Goal), get(Socket, address, Port). %% http_server(:Goal, +Options) is det. % % Start server at given or arbitrary port. http_server(Goal, Options) :- select(port(Port), Options, Options1), !, http_server(Goal, Port, Options1). http_server(_Goal, _Options) :- throw(error(existence_error(option, port), _)). http_server(Goal, Port, _Options) :- strip_module(Goal, M, PlainGoal), ( var(Port) -> new(X, interactive_httpd(M:PlainGoal)), get(X, address, Port) ; new(X, interactive_httpd(M:PlainGoal, Port)) ). /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - XPCE based socket handling for generic HTTP interface infra-structure. This module acts as a replacement for inetd_httpd, which allows a Prolog process to acts as an inet-driven HTTP server. Using this module the user can easily debug HTTP connections or provide services while running the XPCE GUI. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ :- pce_begin_class(interactive_httpd, socket, "Prolog HTTP debugger"). variable(allowed_hosts, chain*, both, "Chain of regex with acceptable peers"). variable(goal, prolog, get, "Goal to use for processing"). variable(out_stream, prolog, get, "Stream for output"). variable(peer, name, get, "Peer connection (host only)"). variable(request, string*, get, "Data for first line"). variable(data, string*, get, "Data for POST request"). variable(chunk_data, string*, get, "Collect chunked input"). variable(mode, {request,header,post_content_length,chunked} := request, get, "Mode of operation"). :- pce_global(@http_end_header_regex, new(regex('\n\r?\n\r?'))). :- pce_global(@http_end_line_regex, new(regex('\n\r?'))). :- pce_global(@http_has_header_regex, new(regex('[^\n]*HTTP/'))). initialise(S, Goal:prolog, Port:[int]) :-> default(Port, 0, ThePort), % anonymous send_super(S, initialise, ThePort), send(S, slot, goal, Goal), send(S, record_separator, @http_end_line_regex), send(S, input_message, message(@receiver, input, @arg1)), send(S, accept_message, message(@arg1, accepted)), send(S, listen, reuse := @on), send(@http_servers, append, S). unlink(S) :-> send(@http_servers, delete_all, S), send_super(S, unlink). :- pce_group(connection). accepted(S) :-> "A new connection is established on this socket":: ( pce_catch_error(_, get(S, peer_name, tuple(Peer, _Port))) -> send(S, slot, peer, Peer), send(S, authorise), debug(connection, 'New connection from ~w', [Peer]), pce_open(S, append, Fd), send(S, slot, out_stream, Fd) ; debug(connection, 'Cannot get peer: closing.', []), free(S) ). authorise(S) :-> "See whether we will proceeed with this connection":: get(S, allowed_hosts, Allowed), ( Allowed == @nil -> true ; get(S, peer, Peer), get(Allowed, find, message(@arg1, match, Peer), _) -> true ; debug(connection, 'Refused connection from ~w', [Peer]), free(S), fail ). unlink(S) :-> ( debugging(connection) -> get(S, peer, Peer), debug(connection, 'Closed connection from ~w', [Peer]) ; true ), ( get(S, slot, out_stream, Fd), Fd \== @nil -> catch(close(Fd), _, true) ; true ), send_super(S, unlink). :- pce_group(request). /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ->input collects input from the stream until an entire request is complete. A request consists of one of the following: ::= \n | HTTP/\n
? - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ input(S, Input:string) :-> "Process input. The argument is the header":: get(S, mode, Mode), ( debugging(input) -> send(@pce, format, 'GOT (mode %s): "%s"\n', Mode, Input) ; true ), ( Mode == request % got first line -> ( send(@http_has_header_regex, match, Input) -> send(S, slot, request, Input), send(S, slot, mode, header), send(S, record_separator, @http_end_header_regex) ; send(S, dispatch, Input) ) ; Mode == header -> send(Input, prepend, S?request), send(S, slot, request, @nil), ( send(S, collect_post_data, Input) -> true ; send(S, dispatch, Input) ) ; Mode == post_content_length -> send(S, slot, mode, request), send(S, record_separator, @http_end_line_regex), get(S, data, Header), send(Header, append, Input), send(Header, lock_object, @on), send(S, slot, data, @nil), send(S, dispatch, Header), send(Header, lock_object, @off) ; Mode == chunked -> get(S, chunk_data, ChunkData), ( get(S, record_separator, Bytes), integer(Bytes) -> send(ChunkData, append, Input), send(S, record_separator, '\n') ; send(Input, prepend, '0x'), get(Input, value, HexAtom), term_to_atom(Bytes, HexAtom), ( Bytes == 0 -> get(S, data, Header), get(ChunkData, size, ContentLength), send(@http_chunked_regex, search, Header), send(@http_chunked_regex, register_value, 0, Header, string('Content-Length: %d', ContentLength)), send(Header, append, ChunkData), send(S, slot, chunk_data, @nil), send(S, slot, mode, request), send(S, record_separator, @http_end_line_regex), send(S, dispatch, Header) ; send(S, record_separator, Bytes) ) ) ). dispatch(S, Input:string) :-> "Hand complete input for dispatching":: ( debugging(dispatch) -> send(@pce, write_ln, Input) ; true ), pce_open(Input, read, In), get(S, goal, Goal), get(S, out_stream, Out), ( catch(http_wrapper(Goal, In, Out, Close, []), E, wrapper_error(E)) -> close(In), ( downcase_atom(Close, 'keep-alive') -> send(S, slot, mode, request), % prepare for next send(S, record_separator, @http_end_line_regex), send(S, slot, data, @nil) ; free(S) ) ; close(In), % exception or failure free(S) ). wrapper_error(Error) :- ( debugging(connection) -> print_message(error, Error) ; true ), fail. :- pce_group(post). :- pce_global(@http_content_length_regex, new(regex('^Content-Length:[[:blank:]]*([0-9]+)', @off))). :- pce_global(@http_chunked_regex, new(regex('^Transfer-encoding:[[:blank:]]*chunked', @off))). collect_post_data(S, Header:string) :-> ( send(@http_content_length_regex, search, Header) -> get(@http_content_length_regex, register_value, Header, 1, int, Len), debug(dispatch, '[POST] Content-length: ~w~n', [Len]), send(S, slot, mode, post_content_length), send(S, slot, data, Header), send(S, record_separator, Len) ; send(@http_chunked_regex, search, Header) -> send(S, slot, mode, chunked), send(S, slot, chunk_data, new(string)), send(S, record_separator, '\n') ). :- pce_end_class(interactive_httpd).