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--[[

   

--]]

---
-- read_query() can rewrite packets
--
-- You can use read_query() to replace the packet sent by the client and rewrite
-- query as you like
--
-- @param packet the mysql-packet sent by the client
--
-- @return 
--   * nothing to pass on the packet as is, 
--   * proxy.PROXY_SEND_QUERY to send the queries from the proxy.queries queue
--   * proxy.PROXY_SEND_RESULT to send your own result-set
--
function read_query( packet )
    if string.byte(packet) == proxy.COM_QUERY then
        local query = string.sub(packet, 2)

        print("we got a normal query: " .. query)

        -- try to match the string up to the first non-alphanum
        local f_s, f_e, command = string.find(packet, "^%s*(%w+)", 2)
        local option

        if f_e then
            -- if that match, take the next sub-string as option
            f_s, f_e, option = string.find(packet, "^%s+(%w+)", f_e + 1)
        end
        
        -- support 
        --
        -- ls [db]
        -- cd db
        -- who

        if command == "ls" then
            if option then
                -- FIXME: SQL INJECTION
                proxy.queries:append(1, string.char(proxy.COM_QUERY) .. "SHOW TABLES FROM " .. option )
            else
                proxy.queries:append(1, string.char(proxy.COM_QUERY) .. "SHOW TABLES" )
            end

            return proxy.PROXY_SEND_QUERY
        elseif command == "who" then
            proxy.queries:append(1, string.char(proxy.COM_QUERY) .. "SHOW PROCESSLIST" )

            return proxy.PROXY_SEND_QUERY
        elseif command == "cd" and option then
            proxy.queries:append(1, string.char(proxy.COM_INIT_DB) .. option )

            return proxy.PROXY_SEND_QUERY
        end
    end
end

---
-- read_query_result() is called when we receive a query result 
-- from the server
--
-- we can analyze the response, drop the response and pass it on (default)
-- 
-- @return 
--   * nothing or proxy.PROXY_SEND_RESULT to pass the result-set to the client
--   * proxy.PROXY_IGNORE_RESULT to drop the result-set
-- 
-- @note: the function has to exist in 0.5.0 if proxy.PROXY_SEND_QUERY 
--   got used in read_query()
--
function read_query_result(inj)
     
end

