lua script for redirecting mysql access via mysqlproxy

gistfile1.lua

local tok = require("proxy.tokenizer")

function read_query(packet)
   if (string.byte(packet) == proxy.COM_QUERY) then
      local replacement_tokens = {}
      local tokens = tok.tokenize(packet:sub(2))
      local modified_p = false
      print("-----")
      print(packet:sub(2))
      print(tok.normalize(tokens))
      for i = 1, #tokens do
         local token = tokens[i]
         print(token.token_name .. " => " .. token.text)
         if (token.token_name == "TK_LITERAL" and token.text == "bonds") then
            table.insert(replacement_tokens, {token_name = "TK_LITERAL", text = "cds_curves"})
            modified_p = true
         else
            table.insert(replacement_tokens, {token_name = token.token_name, text = token.text})
         end
      end
      local replacement_query = tok.tokens_to_query(replacement_tokens)
      print(replacement_query)

      if (modified_p) then
         proxy.queries:append(1, string.char(proxy.COM_QUERY) .. replacement_query )
         return proxy.PROXY_SEND_QUERY
      end
   end
end

-- function read_query( packet )
--    if string.byte(packet) == proxy.COM_QUERY then
--       local query = string.sub(packet, 2)
--       print ("received " .. query)
--       local replacing = false
--       -- matches "CRATE" as first word of the query
--       if string.match(string.upper(query), '^%s*CRATE') then
--          query = string.gsub(query,'^%s*%w+', 'CREATE')
--          replacing = true
--          -- matches "SLECT" as first word of the query
--       elseif string.match(string.upper(query), '^%s*SLECT') then
--          query = string.gsub(query,'^%s*%w+', 'SELECT')
--          replacing = true
--       end
--       if (replacing) then
--          print("replaced with " .. query )
--          proxy.queries:append(1, string.char(proxy.COM_QUERY) .. query )
--          return proxy.PROXY_SEND_QUERY
--       end
--    end
-- end

-- 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