FreeTDS Development Group

[Jason Goemaat <jasong AT netins.net>]

Client: JDK 1.1 and 1.2 on Windows NT and Solaris
Server: Sybase Adaptive Server Enterprise 11.5.1 on Solaris

I have been getting two errors occasionally, not together.  The first one 
occurs very rarely, the second occurs more often (about 1 in 10 connects) 
from FreeTDS-JDBC.  This is the first error:

---------- begin error message ----------
java.sql.SQLException: Unknown packet type 0x0
Packet header is
0000  00 00 00 fa 00 00 00 00                           |........|

        at com.internetcds.jdbc.tds.Driver.connect(Driver.java:280)
        at java.sql.DriverManager.getConnection(Compiled Code)
        at TestFreeTDS.FreeConnect(Compiled Code)
        at TestFreeTDS.main(TestFreeTDS.java:61)
---------- end error message ----------

This is the other error message:
---------- begin error message ----------
java.sql.SQLException: Logon failed.  Msg 5703, Lvl 0, State 1,
Changed language setting to 'us_english'.
, Server , Procedure , Line 1
0 connection are in use by this program
        at 
com.internetcds.jdbc.tds.Connection.allocateTds(Connection.java:341)
        at com.internetcds.jdbc.tds.Connection.<init>(Connection.java:169)
        at com.internetcds.jdbc.tds.Driver.connect(Driver.java:257)
        at java.sql.DriverManager.getConnection(Compiled Code)
        at TestFreeTDS.FreeConnect(Compiled Code)
        at TestFreeTDS.main(TestFreeTDS.java:61)
---------- end error message ----------

First to help diagnose the error I modified Tds.logon() to output the 
message if it gets a PacketErrorResult from the command.

//---------- begin code snippet ----------
         if (result instanceof PacketErrorResult)
         {
            System.err.println("Tds.logon() - PacketErrorResult!");
            System.err.println("  PacketType - " + result.getPacketType());
            System.err.println("  Message - '" + 
((PacketErrorResult)result).getMsg() + "'");
            isOkay = false;
         }
//---------- end code snippet ----------

This showed me a message saying something to the effect that the language 
"*&#~~" could not be found (random garbage characters).  On the server 
there was a stack error in the log files.

I used a proxy program I wrote to store the data going through in the 
packets to the server from JDBC and from a test program.  There were 
several discrepancies in the login packet.  Most notably, the packet from 
FreeTDS was 0x024C long and the reference packet was 0x0248 long.  After a 
lot of tinkering and examining the code, I found the problem.

The remote password section is not sent correctly according to the comments 
at the top of the Tds.logon() method.  I changed the part to the following:

//---------- begin code snippet ----------
      // remote passwords - JLG - commented two lines and added five
//      comm.appendString(password, 255, (byte)0);
//      comm.appendByte((byte)password.length());
      comm.appendByte((byte)0); // magic3
      comm.appendByte((byte)password.length());
      comm.appendString(password, 30, (byte)0);
      comm.appendString("", 223, (byte)0);
      comm.appendByte((byte)(password.length() + 2));
//---------- end code snippet ----------

This is the commented declaration for this section:
    * -- 202 -- DBCHAR magic3; -- 0, dont know this one either --
    * -- 203 -- DBTINYINT password2_length;
    * -- 204 -- DBCHAR password2[30];
    * -- 234 -- DBCHAR magic4[223];
    * -- 457 -- DBTINYINT password2_length_plus2;

After making this change, I haven't had a connection problem yet.

Jason Goemaat
jasong AT netins.net