Merge 0.10->trunk

14 files changed, 706 insertions, 108 deletions

diff --git a/CHANGES b/CHANGES
index d9f9d334..102415b7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -30,6 +30,7 @@ New features
 -   mod\_carbons (XEP-0280)
 -   Pluggable connection timeout handling
 -   mod\_websocket (RFC 7395)
+-   mod\_mam (XEP-0313)
 
 Removed
 -------
diff --git a/plugins/mod_mam/fallback_archive.lib.lua b/plugins/mod_mam/fallback_archive.lib.lua
new file mode 100644
index 00000000..71e65274
--- /dev/null
+++ b/plugins/mod_mam/fallback_archive.lib.lua
@@ -0,0 +1,91 @@
+-- Prosody IM
+-- Copyright (C) 2008-2017 Matthew Wild
+-- Copyright (C) 2008-2017 Waqas Hussain
+-- Copyright (C) 2011-2017 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- luacheck: ignore 212/self
+
+local uuid = require "util.uuid".generate;
+local store = module:shared("archive");
+local archive_store = { _provided_by = "mam"; name = "fallback"; };
+
+function archive_store:append(username, key, value, when, with)
+	local archive = store[username];
+	if not archive then
+		archive = { [0] = 0 };
+		store[username] = archive;
+	end
+	local index = (archive[0] or #archive)+1;
+	local item = { key = key, when = when, with = with, value = value };
+	if not key or archive[key] then
+		key = uuid();
+		item.key = key;
+	end
+	archive[index] = item;
+	archive[key] = index;
+	archive[0] = index;
+	return key;
+end
+
+function archive_store:find(username, query)
+	local archive = store[username] or {};
+	local start, stop, step = 1, archive[0] or #archive, 1;
+	local qstart, qend, qwith = -math.huge, math.huge;
+	local limit;
+
+	if query then
+		if query.reverse then
+			start, stop, step = stop, start, -1;
+			if query.before and archive[query.before] then
+				start = archive[query.before] - 1;
+			end
+		elseif query.after and archive[query.after] then
+			start = archive[query.after] + 1;
+		end
+		qwith = query.with;
+		limit = query.limit;
+		qstart = query.start or qstart;
+		qend = query["end"] or qend;
+	end
+
+	return function ()
+		if limit and limit <= 0 then return end
+		for i = start, stop, step do
+			local item = archive[i];
+			if (not qwith or qwith == item.with) and item.when >= qstart and item.when <= qend then
+				if limit then limit = limit - 1; end
+				start = i + step; -- Start on next item
+				return item.key, item.value, item.when, item.with;
+			end
+		end
+	end
+end
+
+function archive_store:delete(username, query)
+	if not query or next(query) == nil then
+		-- no specifics, delete everything
+		store[username] = nil;
+		return true;
+	end
+	local archive = store[username];
+	if not archive then return true; end -- no messages, nothing to delete
+
+	local qstart = query.start or -math.huge;
+	local qend = query["end"] or math.huge;
+	local qwith = query.with;
+		store[username] = nil;
+	for i = 1, #archive do
+		local item = archive[i];
+		local when, with = item.when, item.when;
+		-- Add things that don't match the query
+		if not ((not qwith or qwith == item.with) and item.when >= qstart and item.when <= qend) then
+			self:append(username, item.key, item.value, when, with);
+		end
+	end
+	return true;
+end
+
+return archive_store;
diff --git a/plugins/mod_mam/mamprefs.lib.lua b/plugins/mod_mam/mamprefs.lib.lua
new file mode 100644
index 00000000..054b6861
--- /dev/null
+++ b/plugins/mod_mam/mamprefs.lib.lua
@@ -0,0 +1,49 @@
+-- Prosody IM
+-- Copyright (C) 2008-2017 Matthew Wild
+-- Copyright (C) 2008-2017 Waqas Hussain
+-- Copyright (C) 2011-2017 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- XEP-0313: Message Archive Management for Prosody
+--
+
+local global_default_policy = module:get_option("default_archive_policy", true);
+
+do
+	-- luacheck: ignore 211/prefs_format
+	local prefs_format = {
+		[false] = "roster",
+		-- default ::= true | false | "roster"
+		-- true = always, false = never, nil = global default
+		["romeo@montague.net"] = true, -- always
+		["montague@montague.net"] = false, -- newer
+	};
+end
+
+local sessions = hosts[module.host].sessions;
+local archive_store = module:get_option_string("archive_store", "archive");
+local prefs = module:open_store(archive_store .. "_prefs");
+
+local function get_prefs(user)
+	local user_sessions = sessions[user];
+	local user_prefs = user_sessions and user_sessions.archive_prefs
+	if not user_prefs and user_sessions then
+		user_prefs = prefs:get(user);
+		user_sessions.archive_prefs = user_prefs;
+	end
+	return user_prefs or { [false] = global_default_policy };
+end
+local function set_prefs(user, user_prefs)
+	local user_sessions = sessions[user];
+	if user_sessions then
+		user_sessions.archive_prefs = user_prefs;
+	end
+	return prefs:set(user, user_prefs);
+end
+
+return {
+	get = get_prefs,
+	set = set_prefs,
+}
diff --git a/plugins/mod_mam/mamprefsxml.lib.lua b/plugins/mod_mam/mamprefsxml.lib.lua
new file mode 100644
index 00000000..0598bbcd
--- /dev/null
+++ b/plugins/mod_mam/mamprefsxml.lib.lua
@@ -0,0 +1,64 @@
+-- Prosody IM
+-- Copyright (C) 2008-2017 Matthew Wild
+-- Copyright (C) 2008-2017 Waqas Hussain
+-- Copyright (C) 2011-2017 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- XEP-0313: Message Archive Management for Prosody
+--
+
+local st = require"util.stanza";
+local xmlns_mam = "urn:xmpp:mam:1";
+
+local default_attrs = {
+	always = true, [true] = "always",
+	never = false, [false] = "never",
+	roster = "roster",
+}
+
+local function tostanza(prefs)
+	local default = prefs[false];
+	default = default_attrs[default];
+	local prefstanza = st.stanza("prefs", { xmlns = xmlns_mam, default = default });
+	local always = st.stanza("always");
+	local never = st.stanza("never");
+	for jid, choice in pairs(prefs) do
+		if jid then
+			(choice and always or never):tag("jid"):text(jid):up();
+		end
+	end
+	prefstanza:add_child(always):add_child(never);
+	return prefstanza;
+end
+local function fromstanza(prefstanza)
+	local prefs = {};
+	local default = prefstanza.attr.default;
+	if default then
+		prefs[false] = default_attrs[default];
+	end
+
+	local always = prefstanza:get_child("always");
+	if always then
+		for rule in always:childtags("jid") do
+			local jid = rule:get_text();
+			prefs[jid] = true;
+		end
+	end
+
+	local never = prefstanza:get_child("never");
+	if never then
+		for rule in never:childtags("jid") do
+			local jid = rule:get_text();
+			prefs[jid] = false;
+		end
+	end
+
+	return prefs;
+end
+
+return {
+	tostanza = tostanza;
+	fromstanza = fromstanza;
+}
diff --git a/plugins/mod_mam/mod_mam.lua b/plugins/mod_mam/mod_mam.lua
new file mode 100644
index 00000000..f6ca52c0
--- /dev/null
+++ b/plugins/mod_mam/mod_mam.lua
@@ -0,0 +1,369 @@
+-- Prosody IM
+-- Copyright (C) 2008-2017 Matthew Wild
+-- Copyright (C) 2008-2017 Waqas Hussain
+-- Copyright (C) 2011-2017 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- XEP-0313: Message Archive Management for Prosody
+--
+
+local xmlns_mam     = "urn:xmpp:mam:1";
+local xmlns_delay   = "urn:xmpp:delay";
+local xmlns_forward = "urn:xmpp:forward:0";
+
+local um = require "core.usermanager";
+local st = require "util.stanza";
+local rsm = require "rsm";
+local get_prefs = module:require"mamprefs".get;
+local set_prefs = module:require"mamprefs".set;
+local prefs_to_stanza = module:require"mamprefsxml".tostanza;
+local prefs_from_stanza = module:require"mamprefsxml".fromstanza;
+local jid_bare = require "util.jid".bare;
+local jid_split = require "util.jid".split;
+local jid_prepped_split = require "util.jid".prepped_split;
+local dataform = require "util.dataforms".new;
+local host = module.host;
+
+local rm_load_roster = require "core.rostermanager".load_roster;
+
+local is_stanza = st.is_stanza;
+local tostring = tostring;
+local time_now = os.time;
+local m_min = math.min;
+local timestamp, timestamp_parse = require "util.datetime".datetime, require "util.datetime".parse;
+local default_max_items, max_max_items = 20, module:get_option_number("max_archive_query_results", 50);
+local global_default_policy = module:get_option("default_archive_policy", true);
+if global_default_policy ~= "roster" then
+	global_default_policy = module:get_option_boolean("default_archive_policy", global_default_policy);
+end
+local strip_tags = module:get_option_set("dont_archive_namespaces", { "http://jabber.org/protocol/chatstates" });
+
+local archive_store = module:get_option_string("archive_store", "archive");
+local archive = assert(module:open_store(archive_store, "archive"));
+
+if archive.name == "null" or not archive.find then
+	if not archive.find then
+		module:log("debug", "Attempt to open archive storage returned a valid driver but it does not seem to implement the storage API");
+		module:log("debug", "mod_%s does not support archiving", archive._provided_by or archive.name and "storage_"..archive.name.."(?)" or "<unknown>");
+	else
+		module:log("debug", "Attempt to open archive storage returned null driver");
+	end
+	module:log("debug", "See https://prosody.im/doc/storage and https://prosody.im/doc/archiving for more information");
+	module:log("info", "Using in-memory fallback archive driver");
+	archive = module:require "fallback_archive";
+end
+
+local cleanup;
+
+-- Handle prefs.
+module:hook("iq/self/"..xmlns_mam..":prefs", function(event)
+	local origin, stanza = event.origin, event.stanza;
+	local user = origin.username;
+	if stanza.attr.type == "get" then
+		local prefs = prefs_to_stanza(get_prefs(user));
+		local reply = st.reply(stanza):add_child(prefs);
+		origin.send(reply);
+	else -- type == "set"
+		local new_prefs = stanza:get_child("prefs", xmlns_mam);
+		local prefs = prefs_from_stanza(new_prefs);
+		local ok, err = set_prefs(user, prefs);
+		if not ok then
+			origin.send(st.error_reply(stanza, "cancel", "internal-server-error", "Error storing preferences: "..tostring(err)));
+		else
+			origin.send(st.reply(stanza));
+		end
+	end
+	return true;
+end);
+
+local query_form = dataform {
+	{ name = "FORM_TYPE"; type = "hidden"; value = xmlns_mam; };
+	{ name = "with"; type = "jid-single"; };
+	{ name = "start"; type = "text-single" };
+	{ name = "end"; type = "text-single"; };
+};
+
+-- Serve form
+module:hook("iq-get/self/"..xmlns_mam..":query", function(event)
+	local origin, stanza = event.origin, event.stanza;
+	origin.send(st.reply(stanza):add_child(query_form:form()));
+	return true;
+end);
+
+-- Handle archive queries
+module:hook("iq-set/self/"..xmlns_mam..":query", function(event)
+	local origin, stanza = event.origin, event.stanza;
+	local query = stanza.tags[1];
+	local qid = query.attr.queryid;
+
+	if cleanup then cleanup[origin.username] = true; end
+
+	-- Search query parameters
+	local qwith, qstart, qend;
+	local form = query:get_child("x", "jabber:x:data");
+	if form then
+		local err;
+		form, err = query_form:data(form);
+		if err then
+			origin.send(st.error_reply(stanza, "modify", "bad-request", select(2, next(err))));
+			return true;
+		end
+		qwith, qstart, qend = form["with"], form["start"], form["end"];
+		qwith = qwith and jid_bare(qwith); -- dataforms does jidprep
+	end
+
+	if qstart or qend then -- Validate timestamps
+		local vstart, vend = (qstart and timestamp_parse(qstart)), (qend and timestamp_parse(qend));
+		if (qstart and not vstart) or (qend and not vend) then
+			origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid timestamp"))
+			return true;
+		end
+		qstart, qend = vstart, vend;
+	end
+
+	module:log("debug", "Archive query, id %s with %s from %s until %s)",
+		tostring(qid), qwith or "anyone", qstart or "the dawn of time", qend or "now");
+
+	-- RSM stuff
+	local qset = rsm.get(query);
+	local qmax = m_min(qset and qset.max or default_max_items, max_max_items);
+	local reverse = qset and qset.before or false;
+	local before, after = qset and qset.before, qset and qset.after;
+	if type(before) ~= "string" then before = nil; end
+
+
+	-- Load all the data!
+	local data, err = archive:find(origin.username, {
+		start = qstart; ["end"] = qend; -- Time range
+		with = qwith;
+		limit = qmax + 1;
+		before = before; after = after;
+		reverse = reverse;
+		total = true;
+	});
+
+	if not data then
+		origin.send(st.error_reply(stanza, "cancel", "internal-server-error", err));
+		return true;
+	end
+	local total = tonumber(err);
+
+	local msg_reply_attr = { to = stanza.attr.from, from = stanza.attr.to };
+
+	local results = {};
+
+	-- Wrap it in stuff and deliver
+	local first, last;
+	local count = 0;
+	local complete = "true";
+	for id, item, when in data do
+		count = count + 1;
+		if count > qmax then
+			complete = nil;
+			break;
+		end
+		local fwd_st = st.message(msg_reply_attr)
+			:tag("result", { xmlns = xmlns_mam, queryid = qid, id = id })
+				:tag("forwarded", { xmlns = xmlns_forward })
+					:tag("delay", { xmlns = xmlns_delay, stamp = timestamp(when) }):up();
+
+		if not is_stanza(item) then
+			item = st.deserialize(item);
+		end
+		item.attr.xmlns = "jabber:client";
+		fwd_st:add_child(item);
+
+		if not first then first = id; end
+		last = id;
+
+		if reverse then
+			results[count] = fwd_st;
+		else
+			origin.send(fwd_st);
+		end
+	end
+
+	if reverse then
+		for i = #results, 1, -1 do
+			origin.send(results[i]);
+		end
+		first, last = last, first;
+	end
+
+	-- That's all folks!
+	module:log("debug", "Archive query %s completed", tostring(qid));
+
+	origin.send(st.reply(stanza)
+		:tag("fin", { xmlns = xmlns_mam, queryid = qid, complete = complete })
+			:add_child(rsm.generate {
+				first = first, last = last, count = total }));
+	return true;
+end);
+
+local function has_in_roster(user, who)
+	local roster = rm_load_roster(user, host);
+	module:log("debug", "%s has %s in roster? %s", user, who, roster[who] and "yes" or "no");
+	return roster[who];
+end
+
+local function shall_store(user, who)
+	-- TODO Cache this?
+	if not um.user_exists(user, host) then
+		return false;
+	end
+	local prefs = get_prefs(user);
+	local rule = prefs[who];
+	module:log("debug", "%s's rule for %s is %s", user, who, tostring(rule));
+	if rule ~= nil then
+		return rule;
+	end
+	-- Below could be done by a metatable
+	local default = prefs[false];
+	module:log("debug", "%s's default rule is %s", user, tostring(default));
+	if default == nil then
+		default = global_default_policy;
+		module:log("debug", "Using global default rule, %s", tostring(default));
+	end
+	if default == "roster" then
+		return has_in_roster(user, who);
+	end
+	return default;
+end
+
+-- Handle messages
+local function message_handler(event, c2s)
+	local origin, stanza = event.origin, event.stanza;
+	local log = c2s and origin.log or module._log;
+	local orig_type = stanza.attr.type or "normal";
+	local orig_from = stanza.attr.from;
+	local orig_to = stanza.attr.to or orig_from;
+	-- Stanza without 'to' are treated as if it was to their own bare jid
+
+	-- Whos storage do we put it in?
+	local store_user = c2s and origin.username or jid_split(orig_to);
+	-- And who are they chatting with?
+	local with = jid_bare(c2s and orig_to or orig_from);
+
+	-- Filter out <stanza-id> that claim to be from us
+	stanza:maptags(function (tag)
+		if tag.name == "stanza-id" and tag.attr.xmlns == "urn:xmpp:sid:0" then
+			local by_user, by_host, res = jid_prepped_split(tag.attr.by);
+			if not res and by_host == module.host and by_user == store_user then
+				return nil;
+			end
+		end
+		return tag;
+	end);
+
+	-- We store chat messages or normal messages that have a body
+	if not(orig_type == "chat" or (orig_type == "normal" and stanza:get_child("body")) ) then
+		log("debug", "Not archiving stanza: %s (type)", stanza:top_tag());
+		return;
+	end
+
+	-- or if hints suggest we shouldn't
+	if not stanza:get_child("store", "urn:xmpp:hints") then -- No hint telling us we should store
+		if stanza:get_child("no-permanent-store", "urn:xmpp:hints")
+			or stanza:get_child("no-store", "urn:xmpp:hints") then -- Hint telling us we should NOT store
+			log("debug", "Not archiving stanza: %s (hint)", stanza:top_tag());
+			return;
+		end
+	end
+
+	if not strip_tags:empty() then
+		stanza = st.clone(stanza);
+		stanza:maptags(function (tag)
+			if strip_tags:contains(tag.attr.xmlns) then
+				return nil;
+			else
+				return tag;
+			end
+		end);
+		if #stanza.tags == 0 then
+			return;
+		end
+	end
+
+	-- Check with the users preferences
+	if shall_store(store_user, with) then
+		log("debug", "Archiving stanza: %s", stanza:top_tag());
+
+		-- And stash it
+		local ok, id = archive:append(store_user, nil, stanza, time_now(), with);
+		if ok then
+			stanza:tag("stanza-id", { xmlns = "urn:xmpp:sid:0", by = store_user.."@"..host, id = id }):up();
+			if cleanup then cleanup[store_user] = true; end
+			module:fire_event("archive-message-added", { origin = origin, stanza = stanza, for_user = store_user, id = id });
+		end
+	else
+		log("debug", "Not archiving stanza: %s (prefs)", stanza:top_tag());
+	end
+end
+
+local function c2s_message_handler(event)
+	return message_handler(event, true);
+end
+
+local cleanup_after = module:get_option_string("archive_expires_after", "1w");
+local cleanup_interval = module:get_option_number("archive_cleanup_interval", 4 * 60 * 60);
+if cleanup_after ~= "never" then
+	local day = 86400;
+	local multipliers = { d = day, w = day * 7, m = 31 * day, y = 365.2425 * day };
+	local n, m = cleanup_after:lower():match("(%d+)%s*([dwmy]?)");
+	if not n then
+		module:log("error", "Could not parse archive_expires_after string %q", cleanup_after);
+		return false;
+	end
+
+	cleanup_after = tonumber(n) * ( multipliers[m] or 1 );
+
+	module:log("debug", "archive_expires_after = %d -- in seconds", cleanup_after);
+
+	if not archive.delete then
+		module:log("error", "archive_expires_after set but mod_%s does not support deleting", archive._provided_by);
+		return false;
+	end
+
+	-- Set of known users to do message expiry for
+	-- Populated either below or when new messages are added
+	cleanup = {};
+
+	-- Iterating over users is not supported by all authentication modules
+	-- Catch and ignore error if not supported
+	pcall(function ()
+		-- If this works, then we schedule cleanup for all known known
+		for user in um.users(module.host) do
+			cleanup[user] = true;
+		end
+	end);
+
+	-- At odd intervals, delete old messages for one user
+	module:add_timer(math.random(10, 60), function()
+		local user = next(cleanup);
+		if user then
+			module:log("debug", "Removing old messages for user %q", user);
+			local ok, err = archive:delete(user, { ["end"] = os.time() - cleanup_after; })
+			if not ok then
+				module:log("warn", "Could not expire archives for user %s: %s", user, err);
+			elseif type(ok) == "number" then
+				module:log("debug", "Removed %d messages", ok);
+			end
+			cleanup[user] = nil;
+		end
+		return math.random(cleanup_interval, cleanup_interval * 2);
+	end);
+end
+
+-- Stanzas sent by local clients
+module:hook("pre-message/bare", c2s_message_handler, 0);
+module:hook("pre-message/full", c2s_message_handler, 0);
+-- Stanszas to local clients
+module:hook("message/bare", message_handler, 0);
+module:hook("message/full", message_handler, 0);
+
+module:hook("account-disco-info", function(event)
+	(event.reply or event.stanza):tag("feature", {var=xmlns_mam}):up();
+end);
+
diff --git a/plugins/mod_storage_sql.lua b/plugins/mod_storage_sql.lua
index 50d9cd0f..7bbae40c 100644
--- a/plugins/mod_storage_sql.lua
+++ b/plugins/mod_storage_sql.lua
@@ -287,7 +287,7 @@ end
 function archive_store:delete(username, query)
 	query = query or {};
 	local user,store = username,self.store;
-	return engine:transaction(function()
+	local stmt, err = engine:transaction(function()
 		local sql_query = "DELETE FROM `prosodyarchive` WHERE %s;";
 		local args = { host, user or "", store, };
 		local where = { "`host` = ?", "`user` = ?", "`store` = ?", };
@@ -300,6 +300,7 @@ function archive_store:delete(username, query)
 		sql_query = sql_query:format(t_concat(where, " AND "));
 		return engine:delete(sql_query, unpack(args));
 	end);
+	return stmt and stmt:affected() or nil, err;
 end
 
 local stores = {
diff --git a/plugins/mod_tls.lua b/plugins/mod_tls.lua
index 7eedb083..5869b2a5 100644
--- a/plugins/mod_tls.lua
+++ b/plugins/mod_tls.lua
@@ -124,9 +124,11 @@ module:hook_stanza("http://etherx.jabber.org/streams", "features", function (ses
 end, 500);
 
 module:hook_stanza(xmlns_starttls, "proceed", function (session, stanza) -- luacheck: ignore 212/stanza
-	module:log("debug", "Proceeding with TLS on s2sout...");
-	session:reset_stream();
-	session.conn:starttls(session.ssl_ctx);
-	session.secure = false;
-	return true;
+	if session.type == "s2sout_unauthed" and can_do_tls(session) then
+		module:log("debug", "Proceeding with TLS on s2sout...");
+		session:reset_stream();
+		session.conn:starttls(session.ssl_ctx);
+		session.secure = false;
+		return true;
+	end
 end);
diff --git a/util-src/crand.c b/util-src/crand.c
index 177511ce..cc2047eb 100644
--- a/util-src/crand.c
+++ b/util-src/crand.c
@@ -1,7 +1,7 @@
 /* Prosody IM
--- Copyright (C) 2008-2016 Matthew Wild
--- Copyright (C) 2008-2016 Waqas Hussain
--- Copyright (C) 2016 Kim Alvefur
+-- Copyright (C) 2008-2017 Matthew Wild
+-- Copyright (C) 2008-2017 Waqas Hussain
+-- Copyright (C) 2016-2017 Kim Alvefur
 --
 -- This project is MIT/X11 licensed. Please see the
 -- COPYING file in the source package for more information.
@@ -11,6 +11,12 @@
 /*
 * crand.c
 * C PRNG interface
+*
+* The purpose of this module is to provide access to a PRNG in
+* environments without /dev/urandom
+*
+* Caution! This has not been extensively tested.
+*
 */
 
 #include "lualib.h"
@@ -19,15 +25,6 @@
 #include <string.h>
 #include <errno.h>
 
-/*
- * TODO: Decide on fixed size or dynamically allocated buffer
- */
-#if 1
-#include <stdlib.h>
-#else
-#define BUFLEN 256
-#endif
-
 #if defined(WITH_GETRANDOM)
 #include <unistd.h>
 #include <sys/syscall.h>
@@ -37,8 +34,11 @@
 #error getrandom() requires Linux 3.17 or later
 #endif
 
-/* Was this not supposed to be a function? */
-int getrandom(char *buf, size_t len, int flags) {
+/*
+ * This acts like a read from /dev/urandom with the exception that it
+ * *does* block if the entropy pool is not yet initialized.
+ */
+int getrandom(void *buf, size_t len, int flags) {
 	return syscall(SYS_getrandom, buf, len, flags);
 }
 
@@ -51,39 +51,16 @@ int getrandom(char *buf, size_t len, int flags) {
 #endif
 
 int Lrandom(lua_State *L) {
-#ifdef BUFLEN
-	unsigned char buf[BUFLEN];
-#else
-	unsigned char *buf;
-#endif
 	int ret = 0;
-	size_t len = (size_t)luaL_checkint(L, 1);
-#ifdef BUFLEN
-	len = len > BUFLEN ? BUFLEN : len;
-#else
-	buf = malloc(len);
-
-	if(buf == NULL) {
-		lua_pushnil(L);
-		lua_pushstring(L, "out of memory");
-		/* or it migth be better to
-		 * return lua_error(L);
-		 */
-		return 2;
-	}
-#endif
+	size_t len = (size_t)luaL_checkinteger(L, 1);
+	void *buf = lua_newuserdata(L, len);
 
 #if defined(WITH_GETRANDOM)
 	ret = getrandom(buf, len, 0);
 
 	if(ret < 0) {
-#ifndef BUFLEN
-		free(buf);
-#endif
-		lua_pushnil(L);
 		lua_pushstring(L, strerror(errno));
-		lua_pushinteger(L, errno);
-		return 3;
+		return lua_error(L);
 	}
 
 #elif defined(WITH_ARC4RANDOM)
@@ -95,40 +72,17 @@ int Lrandom(lua_State *L) {
 	if(ret == 1) {
 		ret = len;
 	} else {
-#ifndef BUFLEN
-		free(buf);
-#endif
-		lua_pushnil(L);
-		lua_pushstring(L, "failed");
-		/* lua_pushinteger(L, ERR_get_error()); */
-		return 2;
+		/* TODO ERR_get_error() */
+		lua_pushstring(L, "RAND_bytes() failed");
+		return lua_error(L);
 	}
 
 #endif
 
-	lua_pushlstring(L, (const char *)buf, ret);
-#ifndef BUFLEN
-	free(buf);
-#endif
+	lua_pushlstring(L, buf, ret);
 	return 1;
 }
 
-#ifdef ENABLE_SEEDING
-int Lseed(lua_State *L) {
-	size_t len;
-	const char *seed = lua_tolstring(L, 1, &len);
-
-#if defined(WITH_OPENSSL)
-	RAND_add(seed, len, len);
-	return 0;
-#else
-	lua_pushnil(L);
-	lua_pushliteral(L, "not-supported");
-	return 2;
-#endif
-}
-#endif
-
 int luaopen_util_crand(lua_State *L) {
 #if (LUA_VERSION_NUM > 501)
 	luaL_checkversion(L);
@@ -136,10 +90,6 @@ int luaopen_util_crand(lua_State *L) {
 	lua_newtable(L);
 	lua_pushcfunction(L, Lrandom);
 	lua_setfield(L, -2, "bytes");
-#ifdef ENABLE_SEEDING
-	lua_pushcfunction(L, Lseed);
-	lua_setfield(L, -2, "seed");
-#endif
 
 #if defined(WITH_GETRANDOM)
 	lua_pushstring(L, "Linux");
@@ -151,7 +101,7 @@ int luaopen_util_crand(lua_State *L) {
 	lua_setfield(L, -2, "_source");
 
 #if defined(WITH_OPENSSL) && defined(_WIN32)
-	/* Do we need to seed this on Windows? */
+	/* TODO Do we need to seed this on Windows? */
 #endif
 
 	return 1;
diff --git a/util-src/encodings.c b/util-src/encodings.c
index 6389b2be..4d6ac437 100644
--- a/util-src/encodings.c
+++ b/util-src/encodings.c
@@ -251,7 +251,6 @@ static const luaL_Reg Reg_utf8[] = {
 	{ NULL,		NULL	}
 };
 
-
 /***************** STRINGPREP *****************/
 #ifdef USE_STRINGPREP_ICU
 
diff --git a/util-src/hashes.c b/util-src/hashes.c
index d6f848c7..697c632f 100644
--- a/util-src/hashes.c
+++ b/util-src/hashes.c
@@ -7,7 +7,6 @@
 --
 */
 
-
 /*
 * hashes.c
 * Lua library for sha1, sha256 and md5 hashes
diff --git a/util-src/pposix.c b/util-src/pposix.c
index 39d8742b..b6874318 100644
--- a/util-src/pposix.c
+++ b/util-src/pposix.c
@@ -595,8 +595,6 @@ int lc_getrlimit(lua_State* L) {
 		return 2;
 	}
 
-
-
 	resource = luaL_checkstring(L, 1);
 	rid = string2resource(resource);
 
diff --git a/util-src/ringbuffer.c b/util-src/ringbuffer.c
index d60a43d9..73a8616b 100644
--- a/util-src/ringbuffer.c
+++ b/util-src/ringbuffer.c
@@ -1,5 +1,4 @@
 
-
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
@@ -8,15 +7,12 @@
 #include <lua.h>
 #include <lauxlib.h>
 
-#define MIN(a, b) ((a)>(b)?(b):(a))
-#define MAX(a, b) ((a)>(b)?(a):(b))
-
 typedef struct {
 	size_t rpos; /* read position */
 	size_t wpos; /* write position */
 	size_t alen; /* allocated size */
 	size_t blen; /* current content size */
-	char* buffer;
+	char buffer[];
 } ringbuffer;
 
 char readchar(ringbuffer* b) {
@@ -76,7 +72,6 @@ int rb_find(lua_State* L) {
 	return 0;
 }
 
-
 int rb_read(lua_State* L) {
 	ringbuffer* b = luaL_checkudata(L, 1, "ringbuffer_mt");
 	int r = luaL_checkinteger(L, 2);
@@ -104,7 +99,6 @@ int rb_read(lua_State* L) {
 	return 1;
 }
 
-
 int rb_readuntil(lua_State* L) {
 	size_t l, m;
 	ringbuffer* b = luaL_checkudata(L, 1, "ringbuffer_mt");
@@ -169,16 +163,12 @@ int rb_free(lua_State* L) {
 
 int rb_new(lua_State* L) {
 	size_t size = luaL_optinteger(L, 1, sysconf(_SC_PAGESIZE));
-	ringbuffer* b = lua_newuserdata(L, sizeof(ringbuffer));
+	ringbuffer *b = lua_newuserdata(L, sizeof(ringbuffer) + size);
+
 	b->rpos = 0;
 	b->wpos = 0;
 	b->alen = size;
 	b->blen = 0;
-	b->buffer = malloc(size);
-
-	if(b->buffer == NULL) {
-		return 0;
-	}
 
 	luaL_getmetatable(L, "ringbuffer_mt");
 	lua_setmetatable(L, -2);
@@ -186,16 +176,6 @@ int rb_new(lua_State* L) {
 	return 1;
 }
 
-int rb_gc(lua_State* L) {
-	ringbuffer* b = luaL_checkudata(L, 1, "ringbuffer_mt");
-
-	if(b->buffer != NULL) {
-		free(b->buffer);
-	}
-
-	return 0;
-}
-
 int luaopen_util_ringbuffer(lua_State* L) {
 #if (LUA_VERSION_NUM > 501)
 	luaL_checkversion(L);
@@ -205,8 +185,6 @@ int luaopen_util_ringbuffer(lua_State* L) {
 		lua_setfield(L, -2, "__tostring");
 		lua_pushcfunction(L, rb_length);
 		lua_setfield(L, -2, "__len");
-		lua_pushcfunction(L, rb_gc);
-		lua_setfield(L, -2, "__gc");
 
 		lua_newtable(L); /* __index */
 		{
diff --git a/util-src/table.c b/util-src/table.c
index 93acae65..c9c09170 100644
--- a/util-src/table.c
+++ b/util-src/table.c
@@ -19,7 +19,6 @@ static int Lpack(lua_State* L) {
 	return 1;
 }
 
-
 int luaopen_util_table(lua_State* L) {
 #if (LUA_VERSION_NUM > 501)
 	luaL_checkversion(L);
diff --git a/util/rsm.lua b/util/rsm.lua
new file mode 100644
index 00000000..40a78fb5
--- /dev/null
+++ b/util/rsm.lua
@@ -0,0 +1,98 @@
+-- Prosody IM
+-- Copyright (C) 2008-2017 Matthew Wild
+-- Copyright (C) 2008-2017 Waqas Hussain
+-- Copyright (C) 2011-2017 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- XEP-0313: Message Archive Management for Prosody
+--
+
+local stanza = require"util.stanza".stanza;
+local tostring, tonumber = tostring, tonumber;
+local type = type;
+local pairs = pairs;
+
+local xmlns_rsm = 'http://jabber.org/protocol/rsm';
+
+local element_parsers = {};
+
+do
+	local parsers = element_parsers;
+	local function xs_int(st)
+		return tonumber((st:get_text()));
+	end
+	local function xs_string(st)
+		return st:get_text();
+	end
+
+	parsers.after = xs_string;
+	parsers.before = function(st)
+			local text = st:get_text();
+			return text == "" or text;
+		end;
+	parsers.max = xs_int;
+	parsers.index = xs_int;
+
+	parsers.first = function(st)
+			return { index = tonumber(st.attr.index); st:get_text() };
+		end;
+	parsers.last = xs_string;
+	parsers.count = xs_int;
+end
+
+local element_generators = setmetatable({
+	first = function(st, data)
+		if type(data) == "table" then
+			st:tag("first", { index = data.index }):text(data[1]):up();
+		else
+			st:tag("first"):text(tostring(data)):up();
+		end
+	end;
+	before = function(st, data)
+		if data == true then
+			st:tag("before"):up();
+		else
+			st:tag("before"):text(tostring(data)):up();
+		end
+	end
+}, {
+	__index = function(_, name)
+		return function(st, data)
+			st:tag(name):text(tostring(data)):up();
+		end
+	end;
+});
+
+
+local function parse(set)
+	local rs = {};
+	for tag in set:childtags() do
+		local name = tag.name;
+		local parser = name and element_parsers[name];
+		if parser then
+			rs[name] = parser(tag);
+		end
+	end
+	return rs;
+end
+
+local function generate(t)
+	local st = stanza("set", { xmlns = xmlns_rsm });
+	for k,v in pairs(t) do
+		if element_parsers[k] then
+			element_generators[k](st, v);
+		end
+	end
+	return st;
+end
+
+local function get(st)
+	local set = st:get_child("set", xmlns_rsm);
+	if set and #set.tags > 0 then
+		return parse(set);
+	end
+end
+
+return { parse = parse, generate = generate, get = get };