[知识整理] Mysql Driver & 协议解析

曾经在负责Mysql时，那会觉得IO就应该是异步的，但是C# 版本Mysql Driver竟然只支持同步调用方式，简直不可接受哇。

然后就研究Mysql Driver，并改了一版异步的实现，并且做了一次小组分享： PPT，抓包分析 (2011/11/3)。

 

接下来为应对故障排查，也做了一版将Mysql 的Pcap抓包解析成为明文文本的工具，就是下文了。想想那会儿真是比较闲了，还能折腾点儿事，最近两年陷入业务不可自拔，荒废了。。。

 

Mysql的客户服服务器协议还是比较简单的，官方有详细的协议说明：http://dev.mysql.com/doc/internals/en/client-server-protocol.html

曾经想写协议解析工具，是为了mysql相关的问题排查和mysql请求统计分析，后来觉得重要性不高，没时间做、只完成request部分解析。

代码写了一部分，不过也能正常工作了，记录一下：

   1:  class MysqlQueryParser : MysqlParser

   2:      {

   3:          private enum ParsingState { PacketHead, Body }

   4:          private StreamBuffer _buffer;

   5:          private ParsingState _state;

   6:          private MysqlQueryPacket _packet;

   7:          public MysqlQueryParser()

   8:          {

   9:              SipcStack.Initialize();

  10:              _buffer = new StreamBuffer();

  11:              _state = ParsingState.PacketHead;

  12:              _packet = new MysqlQueryPacket();

  13:          }

  14:   

  15:          public override void Parse(byte[] data)

  16:          {

  17:              _buffer.Write(data);

  18:              TryParse();

  19:          }

  20:   

  21:          private void TryParse()

  22:          {

  23:              if (_state == ParsingState.PacketHead)

  24:              {

  25:                  if (_buffer.Size >= 4)

  26:                  {

  27:                      byte[] head = new byte[4];

  28:                      _buffer.Read(head, 0, 4);

  29:                      ReadPacketHeader(head, out _packet.PacketLength, out _packet.PacketNum);

  30:                      _state = ParsingState.Body;

  31:                  }

  32:                  else

  33:                      return;

  34:              }

  35:   

  36:              if (_state == ParsingState.Body)

  37:              {

  38:                  if (_buffer.Size >= _packet.PacketLength)

  39:                  {

  40:                      byte[] body = new byte[_packet.PacketLength];

  41:                      _buffer.Read(body, 0, _packet.PacketLength);

  42:                      _packet.Body = body;

  43:                      _packet.Command = (DBCmd)body[0];

  44:                      HandleParseOk();

  45:                  }

  46:              }

  47:          }

  48:   

  49:          private void HandleParseError(string msg)

  50:          {

  51:              _buffer.Close();

  52:              _state = ParsingState.PacketHead;

  53:              _packet = new MysqlQueryPacket();

  54:   

  55:              if (OnParsedError != null)

  56:                  OnParsedError();

  57:          }

  58:   

  59:          private void HandleParseOk()

  60:          {

  61:              if (OnParsedPacket != null)

  62:              {

  63:                  _packet.Time = LastTime;

  64:                  _packet.SrcEP = LastSrcEP;

  65:                  _packet.DstEP = LastDstEP;

  66:                  OnParsedPacket(_packet);

  67:              }

  68:              _state = ParsingState.PacketHead;

  69:              _packet = new MysqlQueryPacket();

  70:          }

  71:      }

   1:    enum ResultSetType

   2:      {

   3:          OK,

   4:          Error,

   5:          ResultSet,

   6:      }

   7:   

   8:      class MysqlResultSetPacket : MysqlPacket

   9:      {

  10:          public MysqlResultSetPacket()

  11:          {

  12:              PacketType = PacketType.ResultSet;

  13:          }

  14:   

  15:          public ResultSetType ResultSetType { get; set; }

  16:      }

  17:   

  18:      class MysqlOKResultSet : MysqlResultSetPacket

  19:      {

  20:          public MysqlOKResultSet()

  21:          {

  22:              ResultSetType = ResultSetType.OK;

  23:          }

  24:          public int PacketLength;

  25:          public int PacketNum;

  26:          public int AffectRow;

  27:          public int ServerState;

  28:          public string Message;

  29:      }

  30:   

  31:      class MysqlOKResultSet : MysqlResultSetPacket

  32:      {

  33:          public MysqlOKResultSet()

  34:          {

  35:              ResultSetType = ResultSetType.Error;

  36:          }

  37:          public int PacketLength;

  38:          public int PacketNum;

  39:          public int ErrorNum;

  40:          public int SqlState;

  41:          public string Message;

  42:      }

  43:   

  44:      class MysqlDataResultSet : MysqlResultSetPacket

  45:      {

  46:          public ResultSetHeadPacket HeadPacket;

  47:          public List<ResultSetFieldPacket> FieldPacket;

  48:          public List<ResultSetRowPacket> RowPacket;

  49:   

  50:          public MysqlDataResultSet()

  51:          {

  52:              ResultSetType = ResultSetType.ResultSet;

  53:          }

  54:      }

  55:   

  56:      public class ResultSetHeadPacket

  57:      {

  58:          public int PacketLength;

  59:          public int PacketNum;

  60:          public int FieldNum;

  61:      }

  62:   

  63:      public class ResultSetFieldPacket

  64:      {

  65:          public int PacketLength;

  66:          public int PacketNum;

  67:      }

  68:   

  69:      public class ResultSetRowPacket

  70:      {

  71:          public int PacketLength;

  72:          public int PacketNum;

  73:      }

   1:  abstract class MysqlParser

   2:      {

   3:          public Action<MysqlPacket> OnParsedPacket;

   4:          public  Action OnParsedError;

   5:   

   6:          public DateTime LastTime { get; set; }

   7:          public IPEndPoint LastSrcEP { get; set; }

   8:          public IPEndPoint LastDstEP { get; set; }

   9:   

  10:          public abstract void Parse(byte[] data);

  11:   

  12:          //The Packet Header

  13:          //Bytes                 Name

  14:          // -----                 ----

  15:          // 3                     Packet Length

  16:          // 1                     Packet Number

  17:   

  18:          // Packet Length: The length, in bytes, of the packet

  19:          //                that follows the Packet Header. There

  20:          //                may be some special values in the most

  21:          //                significant byte. The maximum packet 

  22:          //                length is (2**24 -1),about 16MB.

  23:   

  24:          // Packet Number: A serial number which can be used to

  25:          //                ensure that all packets are present

  26:          //                and in order. The first packet of a

  27:          //                client query will have Packet Number = 0

  28:          //                Thus, when a new SQL statement starts, 

  29:          //                the packet number is re-initialised.

  30:   

  31:          protected void ReadPacketHeader(byte[] header,out int packetLength,out int packetNum)

  32:          {

  33:              if (header == null || header.Length != 4)

  34:                  throw new ArgumentException();

  35:   

  36:              packetLength = (int)header[0] + (((int)header[1]) << 8) + (((int)header[3]) << 16);

  37:              packetNum = header[3];

  38:          }

  39:      }

   1:  class MysqlQueryPacket : MysqlPacket

   2:      {

   3:          public MysqlQueryPacket()

   4:          {

   5:              this.PacketType = PacketType.Query;

   6:          }

   7:          public int PacketLength;

   8:          public int PacketNum;

   9:          public byte[] Body;

  10:          public DBCmd Command;

  11:   

  12:          private string _commandArgs;

  13:          public string CommandArgs

  14:          {

  15:              get

  16:              {

  17:                  if (Command == DBCmd.QUERY && Body != null && Body.Length > 0)

  18:                  {

  19:                      if (_commandArgs == null)

  20:                          _commandArgs = Encoding.UTF8.GetString(Body,1,Body.Length-1);

  21:                  }

  22:   

  23:                  return _commandArgs;

  24:              }

  25:          }

  26:   

  27:          public MysqlCommandArgs ResolveCommand()

  28:          {

  29:              MysqlCommandArgs args = new MysqlCommandArgs();

  30:              args.CmdType = CommandType.Text;

  31:              if (CommandArgs != null)

  32:              {

  33:                  if (CommandArgs.Substring(0, 4) == "CALL")

  34:                  {

  35:                      args.CmdType = CommandType.StoredProcedure;

  36:   

  37:                      int start = CommandArgs.IndexOf("(");

  38:                      if (start > 3)

  39:                          args.ResolveQuery = CommandArgs.Substring(3, start - 3);

  40:                  }

  41:                  else

  42:                  {

  43:                      //todo replace ='xx' to ={}

  44:                  }

  45:              }

  46:   

  47:              return args;

  48:          }

  49:      }

  50:   

  51:      class MysqlCommandArgs

  52:      {

  53:          public CommandType CmdType { get; set; }

  54:          public string ResolveQuery { get; set; }

  55:      }

   1:   enum PacketType

   2:      {

   3:          Query,

   4:          ResultSet,

   5:      }

   6:      class MysqlPacket

   7:      {

   8:          public DateTime Time { get; set; }

   9:          public IPEndPoint SrcEP { get; set; }

  10:          public IPEndPoint DstEP { get; set; }

  11:   

  12:          public PacketType PacketType { get; set; }

  13:      }

   1:  enum DBCmd : byte

   2:      {

   3:          SLEEP = 0,

   4:          QUIT = 1,

   5:          INIT_DB = 2,

   6:          QUERY = 3,

   7:          FIELD_LIST = 4,

   8:          CREATE_DB = 5,

   9:          DROP_DB = 6,

  10:          RELOAD = 7,

  11:          SHUTDOWN = 8,

  12:          STATISTICS = 9,

  13:          PROCESS_INFO = 10,

  14:          CONNECT = 11,

  15:          PROCESS_KILL = 12,

  16:          DEBUG = 13,

  17:          PING = 14,

  18:          TIME = 15,

  19:          DELAYED_INSERT = 16,

  20:          CHANGE_USER = 17,

  21:          BINLOG_DUMP = 18,

  22:          TABLE_DUMP = 19,

  23:          CONNECT_OUT = 20,

  24:          REGISTER_SLAVE = 21,

  25:          PREPARE = 22,

  26:          EXECUTE = 23,

  27:          LONG_DATA = 24,

  28:          CLOSE_STMT = 25,

  29:          RESET_STMT = 26,

  30:          SET_OPTION = 27,

  31:          FETCH = 28

  32:      }