--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_http_upload/mod_http_upload.lua	Sat Jul 18 23:05:09 2015 +0200
@@ -0,0 +1,110 @@
+-- mod_http_upload
+--
+-- Copyright (C) 2015 Kim Alvefur
+--
+-- This file is MIT/X11 licensed.
+-- 
+-- Implementation of HTTP Upload file transfer mechanism used by Conversations
+--
+
+-- imports
+local st = require"util.stanza";
+local lfs = require"lfs";
+local join_path = require"util.paths".join;
+local uuid = require"util.uuid".generate;
+
+-- depends
+module:depends("http");
+
+-- namespace
+local xmlns_http_upload = "eu:siacs:conversations:http:upload";
+
+module:add_feature(xmlns_http_upload);
+
+-- state
+local pending_slots = module:shared("upload_slots");
+
+local storage_path = join_path(prosody.paths.data, module.name);
+lfs.mkdir(storage_path);
+
+-- hooks
+module:hook("iq/host/"..xmlns_http_upload..":request", function (event)
+	local stanza, origin = event.stanza, event.origin;
+	-- local clients only
+	if origin.type ~= "c2s" then
+		origin.send(st.error_reply(stanza, "cancel", "not-authorized"));
+		return true;
+	end
+	-- validate
+	local filename = stanza.tags[1]:get_child_text("filename");
+	if not filename or filename:find("/") then
+		origin.send(st.error_reply(stanza, "modify", "bad-request"));
+		return true;
+	end
+	local reply = st.reply(stanza);
+	reply:tag("slot", { xmlns = xmlns_http_upload });
+	local random = uuid();
+	pending_slots[random.."/"..filename] = origin.full_jid;
+	local url = module:http_url() .. "/" .. random .. "/" .. filename;
+	reply:tag("get"):text(url):up();
+	reply:tag("put"):text(url):up();
+	origin.send(reply);
+	return true;
+end);
+
+-- http service
+local function upload_data(event, path)
+	if not pending_slots[path] then
+		return 401;
+	end
+	local random, filename = path:match("^([^/]+)/([^/]+)$");
+	if not random then
+		return 400;
+	end
+	local dirname = join_path(storage_path, random);
+	if not lfs.mkdir(dirname) then
+		module:log("error", "Could not create directory %s for upload", dirname);
+		return 500;
+	end
+	local full_filename = join_path(dirname, filename);
+	local fh, ferr = io.open(full_filename, "w");
+	if not fh then
+		module:log("error", "Could not open file %s for upload: %s", full_filename, ferr);
+		return 500;
+	end
+	local ok, err = fh:write(event.request.body);
+	if not ok then
+		module:log("error", "Could not write to file %s for upload: %s", full_filename, err);
+		os.remove(full_filename);
+		return 500;
+	end
+	ok, err = fh:close();
+	if not ok then
+		module:log("error", "Could not write to file %s for upload: %s", full_filename, err);
+		os.remove(full_filename);
+		return 500;
+	end
+	module:log("info", "File uploaded by %s to slot %s", pending_slots[path], random);
+	pending_slots[path] = nil;
+	return 200;
+end
+
+local serve_uploaded_files = module:depends("http_files").serve(storage_path);
+
+local function size_only(request, data)
+	request.headers.content_size = #data;
+	return 200;
+end
+
+local function serve_head(event, path)
+	event.send = size_only;
+	return serve_uploaded_files(event, path);
+end
+
+module:provides("http", {
+	route = {
+		["GET /*"] = serve_uploaded_files;
+		["HEAD /*"] = serve_head;
+		["PUT /*"] = upload_data;
+	};
+});