File

util/sql.lua @ 11749:83d6d6a70edf

net.http: fail open if surrounding code does not configure TLS Previously, if surrounding code was not configuring the TLS context used default in net.http, it would not validate certificates at all. This is not a security issue with prosody, because prosody updates the context with `verify = "peer"` as well as paths to CA certificates in util.startup.init_http_client. Nevertheless... Let's not leave this pitfall out there in the open.
author Jonas Schäfer <jonas@wielicki.name>
date Sun, 29 Aug 2021 15:04:47 +0200
parent 10534:8a42fd6702e6
child 12872:a20923f7d5fd
line wrap: on
line source


local setmetatable, getmetatable = setmetatable, getmetatable;
local ipairs = ipairs;
local tostring = tostring;
local type = type;
local assert, pcall, debug_traceback = assert, pcall, debug.traceback;
local xpcall = require "util.xpcall".xpcall;
local t_concat = table.concat;
local log = require "util.logger".init("sql");

local DBI = require "DBI";
-- This loads all available drivers while globals are unlocked
-- LuaDBI should be fixed to not set globals.
DBI.Drivers();
local build_url = require "socket.url".build;

local _ENV = nil;
-- luacheck: std none

local column_mt = {};
local table_mt = {};
local query_mt = {};
--local op_mt = {};
local index_mt = {};

local function is_column(x) return getmetatable(x)==column_mt; end
local function is_index(x) return getmetatable(x)==index_mt; end
local function is_table(x) return getmetatable(x)==table_mt; end
local function is_query(x) return getmetatable(x)==query_mt; end
local function Integer() return "Integer()" end
local function String() return "String()" end

local function Column(definition)
	return setmetatable(definition, column_mt);
end
local function Table(definition)
	local c = {}
	for i,col in ipairs(definition) do
		if is_column(col) then
			c[i], c[col.name] = col, col;
		elseif is_index(col) then
			col.table = definition.name;
		end
	end
	return setmetatable({ __table__ = definition, c = c, name = definition.name }, table_mt);
end
local function Index(definition)
	return setmetatable(definition, index_mt);
end

function table_mt:__tostring()
	local s = { 'name="'..self.__table__.name..'"' }
	for _, col in ipairs(self.__table__) do
		s[#s+1] = tostring(col);
	end
	return 'Table{ '..t_concat(s, ", ")..' }'
end
table_mt.__index = {};
function table_mt.__index:create(engine)
	return engine:_create_table(self);
end
function column_mt:__tostring()
	return 'Column{ name="'..self.name..'", type="'..self.type..'" }'
end
function index_mt:__tostring()
	local s = 'Index{ name="'..self.name..'"';
	for i=1,#self do s = s..', "'..self[i]:gsub("[\\\"]", "\\%1")..'"'; end
	return s..' }';
--	return 'Index{ name="'..self.name..'", type="'..self.type..'" }'
end

local engine = {};
function engine:connect()
	if self.conn then return true; end

	local params = self.params;
	assert(params.driver, "no driver")
	log("debug", "Connecting to [%s] %s...", params.driver, params.database);
	local ok, dbh, err = pcall(DBI.Connect,
		params.driver, params.database,
		params.username, params.password,
		params.host, params.port
	);
	if not ok then return ok, dbh; end
	if not dbh then return nil, err; end
	dbh:autocommit(false); -- don't commit automatically
	self.conn = dbh;
	self.prepared = {};
	local ok, err = self:set_encoding();
	if not ok then
		return ok, err;
	end
	local ok, err = self:onconnect();
	if ok == false then
		return ok, err;
	end
	return true;
end
function engine:onconnect() -- luacheck: ignore 212/self
	-- Override from create_engine()
end

function engine:prepquery(sql)
	if self.params.driver == "MySQL" then
		sql = sql:gsub("\"", "`");
	end
	return sql;
end

function engine:execute(sql, ...)
	local success, err = self:connect();
	if not success then return success, err; end
	local prepared = self.prepared;

	sql = self:prepquery(sql);
	local stmt = prepared[sql];
	if not stmt then
		local err;
		stmt, err = self.conn:prepare(sql);
		if not stmt then return stmt, err; end
		prepared[sql] = stmt;
	end

	-- luacheck: ignore 411/success
	local success, err = stmt:execute(...);
	if not success then return success, err; end
	return stmt;
end

local result_mt = { __index = {
	affected = function(self) return self.__stmt:affected(); end;
	rowcount = function(self) return self.__stmt:rowcount(); end;
} };

local function debugquery(where, sql, ...)
	local i = 0; local a = {...}
	sql = sql:gsub("\n?\t+", " ");
	log("debug", "[%s] %s", where, (sql:gsub("%?", function ()
		i = i + 1;
		local v = a[i];
		if type(v) == "string" then
			v = ("'%s'"):format(v:gsub("'", "''"));
		end
		return tostring(v);
	end)));
end

function engine:execute_query(sql, ...)
	sql = self:prepquery(sql);
	local stmt = assert(self.conn:prepare(sql));
	assert(stmt:execute(...));
	local result = {};
	for row in stmt:rows() do result[#result + 1] = row; end
	stmt:close();
	local i = 0;
	return function() i=i+1; return result[i]; end;
end
function engine:execute_update(sql, ...)
	sql = self:prepquery(sql);
	local prepared = self.prepared;
	local stmt = prepared[sql];
	if not stmt then
		stmt = assert(self.conn:prepare(sql));
		prepared[sql] = stmt;
	end
	assert(stmt:execute(...));
	return setmetatable({ __stmt = stmt }, result_mt);
end
engine.insert = engine.execute_update;
engine.select = engine.execute_query;
engine.delete = engine.execute_update;
engine.update = engine.execute_update;
local function debugwrap(name, f)
	return function (self, sql, ...)
		debugquery(name, sql, ...)
		return f(self, sql, ...)
	end
end
function engine:debug(enable)
	self._debug = enable;
	if enable then
		engine.insert = debugwrap("insert", engine.execute_update);
		engine.select = debugwrap("select", engine.execute_query);
		engine.delete = debugwrap("delete", engine.execute_update);
		engine.update = debugwrap("update", engine.execute_update);
	else
		engine.insert = engine.execute_update;
		engine.select = engine.execute_query;
		engine.delete = engine.execute_update;
		engine.update = engine.execute_update;
	end
end
local function handleerr(err)
	local trace = debug_traceback(err, 3);
	log("debug", "Error in SQL transaction: %s", trace);
	return { err = err, traceback = trace };
end
function engine:_transaction(func, ...)
	if not self.conn then
		local ok, err = self:connect();
		if not ok then return ok, err; end
	end
	--assert(not self.__transaction, "Recursive transactions not allowed");
	log("debug", "SQL transaction begin [%s]", func);
	self.__transaction = true;
	local success, a, b, c = xpcall(func, handleerr, ...);
	self.__transaction = nil;
	if success then
		log("debug", "SQL transaction success [%s]", func);
		local ok, err = self.conn:commit();
		-- LuaDBI doesn't actually return an error message here, just a boolean
		if not ok then return ok, err or "commit failed"; end
		return success, a, b, c;
	else
		log("debug", "SQL transaction failure [%s]: %s", func, a.err);
		if self.conn then self.conn:rollback(); end
		return success, a.err;
	end
end
function engine:transaction(...)
	local ok, ret, b, c = self:_transaction(...);
	if not ok then
		local conn = self.conn;
		if not conn or not conn:ping() then
			log("debug", "Database connection was closed. Will reconnect and retry.");
			self.conn = nil;
			log("debug", "Retrying SQL transaction [%s]", (...));
			ok, ret, b, c = self:_transaction(...);
			log("debug", "SQL transaction retry %s", ok and "succeeded" or "failed");
		else
			log("debug", "SQL connection is up, so not retrying");
		end
		if not ok then
			log("error", "Error in SQL transaction: %s", ret);
		end
	end
	return ok, ret, b, c;
end
function engine:_create_index(index)
	local sql = "CREATE INDEX \""..index.name.."\" ON \""..index.table.."\" (";
	if self.params.driver ~= "MySQL" then
		sql = sql:gsub("^CREATE INDEX", "%1 IF NOT EXISTS");
	end
	for i=1,#index do
		sql = sql.."\""..index[i].."\"";
		if i ~= #index then sql = sql..", "; end
	end
	sql = sql..");"
	if self.params.driver == "MySQL" then
		sql = sql:gsub("\"([,)])", "\"(20)%1");
	end
	if index.unique then
		sql = sql:gsub("^CREATE", "CREATE UNIQUE");
	end
	if self._debug then
		debugquery("create", sql);
	end
	return self:execute(sql);
end
function engine:_create_table(table)
	local sql = "CREATE TABLE \""..table.name.."\" (";
	do
		sql = sql:gsub("^CREATE TABLE", "%1 IF NOT EXISTS");
	end
	for i,col in ipairs(table.c) do
		local col_type = col.type;
		if col_type == "MEDIUMTEXT" and self.params.driver ~= "MySQL" then
			col_type = "TEXT"; -- MEDIUMTEXT is MySQL-specific
		end
		if col.auto_increment == true and self.params.driver == "PostgreSQL" then
			col_type = "BIGSERIAL";
		end
		sql = sql.."\""..col.name.."\" "..col_type;
		if col.nullable == false then sql = sql.." NOT NULL"; end
		if col.primary_key == true then sql = sql.." PRIMARY KEY"; end
		if col.auto_increment == true then
			if self.params.driver == "MySQL" then
				sql = sql.." AUTO_INCREMENT";
			elseif self.params.driver == "SQLite3" then
				sql = sql.." AUTOINCREMENT";
			end
		end
		if i ~= #table.c then sql = sql..", "; end
	end
	sql = sql.. ");"
	if self.params.driver == "MySQL" then
		sql = sql:gsub(";$", (" CHARACTER SET '%s' COLLATE '%s_bin';"):format(self.charset, self.charset));
	end
	if self._debug then
		debugquery("create", sql);
	end
	local success,err = self:execute(sql);
	if not success then return success,err; end
	for _, v in ipairs(table.__table__) do
		if is_index(v) then
			self:_create_index(v);
		end
	end
	return success;
end
function engine:set_encoding() -- to UTF-8
	local driver = self.params.driver;
	if driver == "SQLite3" then
		return self:transaction(function()
			for encoding in self:select"PRAGMA encoding;" do
				if encoding[1] == "UTF-8" then
					self.charset = "utf8";
				end
			end
		end);
	end
	local set_names_query = "SET NAMES '%s';"
	local charset = "utf8";
	if driver == "MySQL" then
		self:transaction(function()
			for row in self:select[[
				SELECT "CHARACTER_SET_NAME"
				FROM "information_schema"."CHARACTER_SETS"
				WHERE "CHARACTER_SET_NAME" LIKE 'utf8%'
				ORDER BY MAXLEN DESC LIMIT 1;
				]] do
				charset = row and row[1] or charset;
			end
		end);
		set_names_query = set_names_query:gsub(";$", (" COLLATE '%s';"):format(charset.."_bin"));
	end
	self.charset = charset;
	log("debug", "Using encoding '%s' for database connection", charset);
	local ok, err = self:transaction(function() return self:execute(set_names_query:format(charset)); end);
	if not ok then
		return ok, err;
	end

	if driver == "MySQL" then
		local ok, actual_charset = self:transaction(function ()
			return self:select"SHOW SESSION VARIABLES LIKE 'character_set_client'";
		end);
		if not ok then
			return false, "Failed to detect connection encoding";
		end
		local charset_ok = true;
		for row in actual_charset do
			if row[2] ~= charset then
				log("error", "MySQL %s is actually %q (expected %q)", row[1], row[2], charset);
				charset_ok = false;
			end
		end
		if not charset_ok then
			return false, "Failed to set connection encoding";
		end
	end

	return true;
end
local engine_mt = { __index = engine };

local function db2uri(params)
	return build_url{
		scheme = params.driver,
		user = params.username,
		password = params.password,
		host = params.host,
		port = params.port,
		path = params.database,
	};
end

local function create_engine(_, params, onconnect)
	return setmetatable({ url = db2uri(params), params = params, onconnect = onconnect }, engine_mt);
end

return {
	is_column = is_column;
	is_index = is_index;
	is_table = is_table;
	is_query = is_query;
	Integer = Integer;
	String = String;
	Column = Column;
	Table = Table;
	Index = Index;
	create_engine = create_engine;
	db2uri = db2uri;
};