aboutsummaryrefslogtreecommitdiffstats
path: root/core/xmlhandlers.lua
blob: 9e8fd7f6704a00bf4fc4c0ad84440fa1b259dfd2 (plain)
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
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
-- 
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--



require "util.stanza"

local st = stanza;
local tostring = tostring;
local pairs = pairs;
local ipairs = ipairs;
local t_insert = table.insert;
local t_concat = table.concat;

local default_log = require "util.logger".init("xmlhandlers");

-- COMPAT: w/LuaExpat 1.1.0
local lxp_supports_doctype = pcall(lxp.new, { StartDoctypeDecl = false });

if not lxp_supports_doctype then
	default_log("warn", "The version of LuaExpat on your system leaves Prosody "
		.."vulnerable to denial-of-service attacks. You should upgrade to "
		.."LuaExpat 1.1.1 or higher as soon as possible. See "
		.."http://prosody.im/doc/depends#luaexpat for more information.");
end

local error = error;

module "xmlhandlers"

local ns_prefixes = {
						["http://www.w3.org/XML/1998/namespace"] = "xml";
				}

function init_xmlhandlers(session, stream_callbacks)
		local ns_stack = { "" };
		local curr_tag;
		local chardata = {};
		local xml_handlers = {};
		local log = session.log or default_log;
		
		local cb_streamopened = stream_callbacks.streamopened;
		local cb_streamclosed = stream_callbacks.streamclosed;
		local cb_error = stream_callbacks.error or function (session, e) error("XML stream error: "..tostring(e)); end;
		local cb_handlestanza = stream_callbacks.handlestanza;
		
		local stream_tag = stream_callbacks.stream_tag;
		local stream_default_ns = stream_callbacks.default_ns;
		
		local stanza
		function xml_handlers:StartElement(tagname, attr)
			if stanza and #chardata > 0 then
				-- We have some character data in the buffer
				stanza:text(t_concat(chardata));
				chardata = {};
			end
			local curr_ns,name = tagname:match("^([^\1]*)\1?(.*)$");
			if name == "" then
				curr_ns, name = "", curr_ns;
			end

			if curr_ns ~= stream_default_ns then
				attr.xmlns = curr_ns;
			end
			
			-- FIXME !!!!!
			for i=1,#attr do
				local k = attr[i];
				attr[i] = nil;
				local ns, nm = k:match("^([^\1]*)\1?(.*)$");
				if nm ~= "" then
					ns = ns_prefixes[ns]; 
					if ns then 
						attr[ns..":"..nm] = attr[k];
						attr[k] = nil;
					end
				end
			end
			
			if not stanza then --if we are not currently inside a stanza
				if session.notopen then
					if tagname == stream_tag then
						if cb_streamopened then
							cb_streamopened(session, attr);
						end
					else
						-- Garbage before stream?
						cb_error(session, "no-stream");
					end
					return;
				end
				if curr_ns == "jabber:client" and name ~= "iq" and name ~= "presence" and name ~= "message" then
					cb_error(session, "invalid-top-level-element");
				end
				
				stanza = st.stanza(name, attr);
				curr_tag = stanza;
			else -- we are inside a stanza, so add a tag
				attr.xmlns = nil;
				if curr_ns ~= stream_default_ns then
					attr.xmlns = curr_ns;
				end
				stanza:tag(name, attr);
			end
		end
		function xml_handlers:CharacterData(data)
			if stanza then
				t_insert(chardata, data);
			end
		end
		function xml_handlers:EndElement(tagname)
			local curr_ns,name = tagname:match("^([^\1]*)\1?(.*)$");
			if name == "" then
				curr_ns, name = "", curr_ns;
			end
			if (not stanza) or (#stanza.last_add > 0 and name ~= stanza.last_add[#stanza.last_add].name) then 
				if tagname == stream_tag then
					if cb_streamclosed then
						cb_streamclosed(session);
					end
				elseif name == "error" then
					cb_error(session, "stream-error", stanza);
				else
					cb_error(session, "parse-error", "unexpected-element-close", name);
				end
				stanza, chardata = nil, {};
				return;
			end
			if #chardata > 0 then
				-- We have some character data in the buffer
				stanza:text(t_concat(chardata));
				chardata = {};
			end
			-- Complete stanza
			if #stanza.last_add == 0 then
				cb_handlestanza(session, stanza);
				stanza = nil;
			else
				stanza:up();
			end
		end

		local function restricted_handler()
			cb_error(session, "parse-error", "restricted-xml", "Restricted XML, see RFC 6120 section 11.1.");
		end
		
		if lxp_supports_doctype then
			xml_handlers.StartDoctypeDecl = restricted_handler;
		end
		xml_handlers.Comment = restricted_handler;
		xml_handlers.ProcessingInstruction = restricted_handler;
	
	return xml_handlers;
end

return init_xmlhandlers;