/usr/share/Yap/http/http_host.pl is in yap 6.2.2-6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 | /* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@cs.vu.nl
WWW: http://www.swi-prolog.org
Copyright (C): 2007-2010, University of Amsterdam,
VU University 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 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(http_host,
[ http_current_host/4 % +Request, -Host, -Port, +Options
]).
:- use_module(library('http/thread_httpd')).
:- use_module(library(socket)).
:- use_module(library(option)).
:- use_module(library(settings)).
:- setting(http:public_host, atom, '',
'Name the outside world can use to contact me').
:- setting(http:public_port, integer, 80,
'Port on the public server').
/** <module> Obtain public server location
This library finds the public address of the running server. This can be
used to construct URLs that are visible from anywhere on the internet.
This module was introduced to deal with OpenID, where a reques is
redirected to the OpenID server, which in turn redirects to our server
(see http_openid.pl).
The address is established from the settings http:public_host and
http:public_port if provided. Otherwise it is deduced from the request.
*/
%% http_current_host(+Request, -Hostname, -Port, Options) is det.
%
% Current global host and port of the HTTP server. This is the
% basis to form absolute address, which we need for redirection
% based interaction such as the OpenID protocol. Options are:
%
% * global(+Bool)
% If =true= (default =false=), try to replace a local hostname
% by a world-wide accessible name.
http_current_host(_, Host, Port, _) :-
setting(http:public_host, PublicHost), PublicHost \== '', !,
Host = PublicHost,
setting(http:public_port, Port).
http_current_host(Request, Host, Port, Options) :-
( memberchk(x_forwarded_host(Forwarded), Request)
-> Port = 80,
primary_forwarded_host(Forwarded, Host)
; memberchk(host(Host0), Request),
( option(global(true), Options, false)
-> global_host(Host0, Host)
; Host = Host0
),
option(port(Port), Request, 80)
-> true
; gethostname(Host),
http_current_server(_Pred, Port) % TBD: May be more
).
%% primary_forwarded_host(+Spec, -Host) is det.
%
% x_forwarded host contains multiple hosts seperated by ', ' if
% there are multiple proxy servers in between. The first one is
% the one the user's browser knows about.
primary_forwarded_host(Spec, Host) :-
sub_atom(Spec, B, _, _, ','), !,
sub_atom(Spec, 0, B, _, Host).
primary_forwarded_host(Host, Host).
%% global_host(+HostIn, -Host)
%
% Globalize a hostname. Used if we need to pass our hostname to a
% client and expect the client to be able to contact us. In this
% case we cannot use a name such as `localhost' or the plain
% hostname of the machine. We assume (possibly wrongly) that if
% the host contains a '.', it is globally accessible.
%
% If the heuristics used by this predicate do not suffice, the
% setting http:public_host can be used to override.
global_host(_, Host) :-
setting(http:public_host, PublicHost), PublicHost \== '', !,
Host = PublicHost.
global_host(localhost, Host) :- !,
gethostname(Host).
global_host(Local, Host) :-
sub_atom(Local, _, _, _, '.'), !,
Host = Local.
global_host(Local, Host) :-
tcp_host_to_address(Local, IP),
tcp_host_to_address(Host, IP).
|