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net.server_epoll: Call :shutdown() on TLS sockets when supported Comment from Matthew: This fixes a potential issue where the Prosody process gets blocked on sockets waiting for them to close. Unlike non-TLS sockets, closing a TLS socket sends layer 7 data, and this can cause problems for sockets which are in the process of being cleaned up. This depends on LuaSec changes which are not yet upstream. From Martijn's original email: So first my analysis of luasec. in ssl.c the socket is put into blocking mode right before calling SSL_shutdown() inside meth_destroy(). My best guess to why this is is because meth_destroy is linked to the __close and __gc methods, which can't exactly be called multiple times and luasec does want to make sure that a tls session is shutdown as clean as possible. I can't say I disagree with this reasoning and don't want to change this behaviour. My solution to this without changing the current behaviour is to introduce a shutdown() method. I am aware that this overlaps in a conflicting way with tcp's shutdown method, but it stays close to the OpenSSL name. This method calls SSL_shutdown() in the current (non)blocking mode of the underlying socket and returns a boolean whether or not the shutdown is completed (matching SSL_shutdown()'s 0 or 1 return values), and returns the familiar ssl_ioerror() strings on error with a false for completion. This error can then be used to determine if we have wantread/wantwrite to finalize things. Once meth_shutdown() has been called once a shutdown flag will be set, which indicates to meth_destroy() that the SSL_shutdown() has been handled by the application and it shouldn't be needed to set the socket to blocking mode. I've left the SSL_shutdown() call in the LSEC_STATE_CONNECTED to prevent TOCTOU if the application reaches a timeout for the shutdown code, which might allow SSL_shutdown() to clean up anyway at the last possible moment. Another thing I've changed to luasec is the call to socket_setblocking() right before calling close(2) in socket_destroy() in usocket.c. According to the latest POSIX[0]: Note that the requirement for close() on a socket to block for up to the current linger interval is not conditional on the O_NONBLOCK setting. Which I read to mean that removing O_NONBLOCK on the socket before close doesn't impact the behaviour and only causes noise in system call tracers. I didn't touch the windows bits of this, since I don't do windows. For the prosody side of things I've made the TLS shutdown bits resemble interface:onwritable(), and put it under a combined guard of self._tls and self.conn.shutdown. The self._tls bit is there to prevent getting stuck on this condition, and self.conn.shutdown is there to prevent the code being called by instances where the patched luasec isn't deployed. The destroy() method can be called from various places and is read by me as the "we give up" error path. To accommodate for these unexpected entrypoints I've added a single call to self.conn:shutdown() to prevent the socket being put into blocking mode. I have no expectations that there is any other use here. Same as previous, the self.conn.shutdown check is there to make sure it's not called on unpatched luasec deployments and self._tls is there to make sure we don't call shutdown() on tcp sockets. I wouldn't recommend logging of the conn:shutdown() error inside close(), since a lot of clients simply close the connection before SSL_shutdown() is done.

local function parse(arg, config)
	local short_params = config and config.short_params or {};
	local value_params = config and config.value_params or {};
	local array_params = config and config.array_params or {};

	local parsed_opts = {};

	if #arg == 0 then
		return parsed_opts;
	end
	while true do
		local raw_param = arg[1];
		if not raw_param then
			break;
		end

		local prefix = raw_param:match("^%-%-?");
		if not prefix then
			break;
		elseif prefix == "--" and raw_param == "--" then
			table.remove(arg, 1);
			break;
		end
		local param = table.remove(arg, 1):sub(#prefix+1);
		if #param == 1 and short_params then
			param = short_params[param];
		end

		if not param then
			return nil, "param-not-found", raw_param;
		end

		local param_k, param_v;
		if value_params[param] or array_params[param] then
			param_k, param_v = param, table.remove(arg, 1);
			if not param_v then
				return nil, "missing-value", raw_param;
			end
		else
			param_k, param_v = param:match("^([^=]+)=(.+)$");
			if not param_k then
				if param:match("^no%-") then
					param_k, param_v = param:sub(4), false;
				else
					param_k, param_v = param, true;
				end
			end
			param_k = param_k:gsub("%-", "_");
		end
		if array_params[param] then
			if parsed_opts[param_k] then
				table.insert(parsed_opts[param_k], param_v);
			else
				parsed_opts[param_k] = { param_v };
			end
		else
			parsed_opts[param_k] = param_v;
		end
	end
	for i = 1, #arg do
		parsed_opts[i] = arg[i];
	end
	return parsed_opts;
end

return {
	parse = parse;
}