1. -- mod_http_upload_external
2. --
3. -- Copyright (C) 2016 Sebastian Luksch
4. --
5. -- This file is MIT/X11 licensed.
6. --
7. -- Implementation of HTTP Upload file transfer mechanism used by Conversations
8. --
9. -- Query external HTTP server to retrieve URLs
10. --
11.  
12. -- configuration
13. local external_url = module:get_option("http_upload_external_url");
14. local xmpp_server_key = module:get_option("http_upload_external_server_key");
15.  
16. -- imports
17. local st = require"util.stanza";
18. local http = require"socket.http";
19. local json = require"util.json";
20.  
21. -- depends
22. module:depends("disco");
23.  
24. -- namespace
25. local xmlns_http_upload = "urn:xmpp:http:upload";
26.  
27. module:add_feature(xmlns_http_upload);
28.  
29. -- hooks
30. module:hook("iq/host/"..xmlns_http_upload..":request", function (event)
31.    local stanza, origin = event.stanza, event.origin;
32.    local orig_from = stanza.attr.from;
33.    local request = stanza.tags[1];
34.    -- local clients only
35.    if origin.type ~= "c2s" then
36.       origin.send(st.error_reply(stanza, "cancel", "not-authorized"));
37.       return true;
38.    end
39.    -- check configuration
40.    if not external_url or not xmpp_server_key then
41.       module:log("debug", "missing configuration options: http_upload_external_url and/or http_upload_external_server_key");
42.       origin.send(st.error_reply(stanza, "cancel", "internal-server-error"));
43.       return true;
44.    end
45.    -- validate
46.    local filename = request:get_child_text("filename");
47.    if not filename then
48.       origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid filename"));
49.       return true;
50.    end
51.    local filesize = tonumber(request:get_child_text("size"));
52.    if not filesize then
53.       origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing or invalid file size"));
54.       return true;
55.    end
56.  
57.    local content_type = request:get_child_text("content-type");
58.    
59.    -- build the body
60.    local reqbody = "xmpp_server_key=" .. xmpp_server_key .. "&size=" .. filesize .. "&filename=" .. filename .. "&user_jid=" .. orig_from;
61.    if content_type then
62.       reqbody = reqbody .. "&content_type=" .. content_type;
63.    end
64.  
65.    -- the request
66.    local respbody, statuscode = http.request(external_url, reqbody);
67.    respbody = string.gsub(respbody, "\\/", "/")
68.  
69.    local get_url = nil;
70.    local put_url = nil;
71.  
72.    -- check the response
73.    if statuscode == 500 then
74.       origin.send(st.error_reply(stanza, "cancel", "service-unavailable", respbody));
75.    elseif statuscode == 406 or statuscode == 400 or statuscode == 403 then
76.       local errobj, pos, err = json.decode(respbody);
77.       if err then
78.          origin.send(st.error_reply(stanza, "wait", "internal-server-error", err));
79.          return true;
80.       else
81.          if errobj["err_code"] ~= nil and errobj["msg"] ~= nil then
82.             if errobj.err_code == 1 then
83.                origin.send(st.error_reply(stanza, "modify", "not-acceptable", errobj.msg));
84.                return true;
85.             elseif errobj.err_code == 2 then
86.                origin.send(st.error_reply(stanza, "modify", "not-acceptable", errobj.msg,
87.                   st.stanza("file-too-large", {xmlns=xmlns_http_upload})
88.                      :tag("max-size"):text(errobj.parameters.max_file_size)));
89.                return true;
90.             elseif errobj.err_code == 3 then
91.                origin.send(st.error_reply(stanza, "modify", "not-acceptable", errobj.msg,
92.                   st.stanza("invalid-character", {xmlns=xmlns_http_upload})
93.                      :text(errobj.parameters.invalid_character)));
94.                return true;
95.             elseif errobj.err_code == 4 then
96.                origin.send(st.error_reply(stanza, "cancel", "internal-server-error", errobj.msg,
97.                   st.stanza("missing-parameter", {xmlns=xmlns_http_upload})
98.                      :text(errobj.parameters.missing_parameter)));
99.                return true;
100.             else
101.                origin.send(st.error_reply(stanza, "cancel", "undefined-condition", "unknown err_code"));
102.                return true;
103.             end
104.          elseif statuscode == 403 and errobj["msg"] ~= nil then
105.             origin.send(st.error_reply(stanza, "cancel", "internal-server-error", errobj.msg));
106.          else
107.             origin.send(st.error_reply(stanza, "cancel", "undefined-condition", "msg or err_code not found"));
108.             return true;
109.          end
110.       end
111.    elseif statuscode == 200 then
112.       local respobj, pos, err = json.decode(respbody);
113.       if err then
114.          origin.send(st.error_reply(stanza, "wait", "internal-server-error", err));
115.          return true;
116.       else
117.          if respobj["get"] ~= nil and respobj["put"] ~= nil then
118.             get_url = respobj.get;
119.             put_url = respobj.put;
120.          else
121.             origin.send(st.error_reply(stanza, "cancel", "undefined-condition", "get or put not found"));
122.             return true;
123.          end
124.       end
125.    else
126.       origin.send(st.error_reply(stanza, "cancel", "undefined-condition", "status code: " .. statuscode .. " response: " ..respbody));
127.       return true;
128.    end
129.  
130.    local reply = st.reply(stanza);
131.    reply:tag("slot", { xmlns = xmlns_http_upload });
132.    reply:tag("get"):text(get_url):up();
133.    reply:tag("put"):text(put_url):up();
134.    origin.send(reply);
135.    return true;
136. end);