FreeTDS Development Group

["Michael Horowitz" <michael.horowitz AT storagenetworks.com>]

I was using TDS version 4.2 in my tests.

--Mike

> I just ran a test.  Maybe we need a check against the
> protocol level.  I'm using TDS version 4.6 protocol
> from AIX with FreeTDS to Solaris with Sybase.
> 
> Does anyone have an eclectic set of servers and a big
> endian client?
> 
> Maybe we need the change to depend on wether you
> enable the mssql stuff or another config flag?  for
> TDSVER set to 4.2, 4.6, and 5.0 however with the
> servers I have to chat to I don't get any messages
> unless I use the if I have.  But, both machines in any
> of my configurations are big endian. 
> 
> --- Michael Horowitz
> <michael.horowitz AT storagenetworks.com> wrote:
> > Hey Chris,
> > 
> > There was a thread about the big endian issue 2-3
> > weeks ago(I am
> > connecting from a Solaris box).  I came across the
> > same problem.  I
> > initially just erased the second swap, but I was
> > informed that would cause
> > problems when "emulate little endian" wasn't on. 
> > So, I conditioned the
> > second swap on "if (!tds->emul_little_endian)".  I
> > noticed you did "if
> > (tds->emul_little_endian)" in your patch, are you
> > sure you didn't mean the
> > other way?  tds_get_int does the swap if
> > emul_little_endian is true, so
> > you only want to swap it if tds_get_int didn't swap
> > it already, which is
> > if emul_little_endian is false.
> > 
> > In my experience with MS SQL Server 7.0, I MUST use
> > emul_little_endian,
> > otherwise the datetime fields have their bytes
> > backwards and the "swap
> > broken dates" seems to do nothing for me.
> > 
> > I tested this fix on MS SQL Server 7.0 and 2000 with
> > mixed results.
> > This is what I wrote in a previous email about it:
> > "Actually, I tried SQL Server 2000 without
> > "emulate-little-endian" and
> > with
> > that swap removed and the datetime fields are fine
> > and so are the error
> > messages.
> > With SQL Server 7.0 with the same setup, the
> > datetime fields are wrong,
> > and the error messages are messed up.
> > 
> > I tried using the following instead of completely
> > removing the swap:
> > if (!tds->emul_little_endian) {
> >        tds_swap_bytes(&rc, 4);
> > }
> > That fixed the error messages on SQL Server 7.0, but
> > then they were
> > screwed up on SQL Server 2000."
> > 
> > Anyway, it seems that you have had a similar problem
> > with the big endian
> > issue as me, so I wanted to chyme in with my
> > experience with it.  While
> > either of the fixes seems to work under specific
> > configurations, I am not
> > sure what the final fix should be to make it work
> > under all platforms and
> > with all types of SQL Servers both MS and Sybase.
> > 
> > Do you have any other info that might help with
> > this?
> > 
> > Thanks,
> > 
> > Mike
> > 
> > 
> > > below is a patch that includes what I did for the
> > > strange serve on my network.  More importantly
> > however
> > > are the changes for big endian platforms towards
> > the
> > > end with messages.  The symptom I was seeing was
> > that
> > > errors and messages were not being handled. 
> > trackign
> > > through the code this appeared to be happenning
> > > because of a double endian swap.  I have also had
> > to
> > > make some changes to the dblib call to the message
> > > handler as it did not pass the final argument of
> > the
> > > line number.  I will send that patch as it is
> > rather
> > > simple if anyone needs it.
> > > 
> > > 
> > > *** freetds-0.53-orig/src/tds/token.c   Sun Nov 25
> > > 19:04:17 2001
> > > --- freetds-0.53/src/tds/token.c        Fri Jan 18
> > > 14:54:07 2002
> > > ***************
> > > *** 185,192 ****
> > >                                 ack =
> > > tds_get_byte(tds);
> > >                                 major_ver =
> > > tds_get_byte(tds);
> > >                                 minor_ver =
> > > tds_get_byte(tds);
> > > !                               tds_get_n(tds,
> > NULL,
> > > len-4);
> > > !                               tds_get_byte(tds);
> > >   #ifdef WORDS_BIGENDIAN
> > >   /*
> > >                                 if (major_ver==7)
> > {
> > > --- 185,219 ----
> > >                                 ack =
> > > tds_get_byte(tds);
> > >                                 major_ver =
> > > tds_get_byte(tds);
> > >                                 minor_ver =
> > > tds_get_byte(tds);
> > > !                               if ((major_ver ==
> > 4)
> > > && (minor_ver == 6)) {
> > > !                                   int tlen;
> > > !                                   char
> > > servname[1024];
> > > !
> > > !                                  
> > tds_get_byte(tds);
> > > /* teeny version */
> > > !                                  
> > tds_get_byte(tds);
> > > /* tiny version */
> > > !                                   tlen =
> > > tds_get_byte(tds); /* servname len */
> > > !                                   if (tlen >=
> > > sizeof(servname))
> > > !                                       tlen =
> > > sizeof(servname) - 1;
> > > !                                   tds_get_n(tds,
> > > servname, tlen);
> > > !                                   servname[tlen]
> > =
> > > '\000';
> > > !                                   if
> > > (!strcmp(servname, "OpenServer")) {
> > > !                                       if (ack ==
> > 0)
> > > succeed=TDS_SUCCEED;
> > > !                                   }
> > > !                                   /* eat the
> > rest of
> > > the data as below */
> > > !                                   tds_get_n(tds,
> > > NULL, len -
> > > !                                              
> > > 1/*ack*/ -
> > > !                                              
> > > 4/*major.minor.teeny.tiny*/ -
> > > !                                              
> > > 1/*servnamelen*/ -
> > > !                                              
> > > tlen/*servname*/);
> > > !                               } else {
> > > !                                   /*
> > > !                                    * shouldn't
> > these
> > > 2 just be len - 3?
> > > !                                    * after all
> > we
> > > haev read 3 bytes of the
> > > !                                    * total
> > length.
> > > !                                    */
> > > !                                   tds_get_n(tds,
> > > NULL, len-4);
> > > !                                  
> > tds_get_byte(tds);
> > > !                               }
> > >   #ifdef WORDS_BIGENDIAN
> > >   /*
> > >                                 if (major_ver==7)
> > {
> > > ***************
> > > *** 1134,1143 ****
> > > 
> > >         /* message number */
> > >                 /* swap bytes on bigendian systems
> > > (mlilback, 11/7/01) */
> > >         rc = tds_get_int(tds);
> > >   #ifdef WORDS_BIGENDIAN
> > > !       tds_swap_bytes(&rc, 4);
> > > ! #endif
> > >         tds->msg_info->msg_number = rc;
> > > 
> > >         /* msg state */
> > > --- 1161,1176 ----
> > > 
> > >         /* message number */
> > >                 /* swap bytes on bigendian systems
> > > (mlilback, 11/7/01) */
> > > +               /*
> > > +                * we have to be careful not to
> > double
> > > swap here.
> > > +                * tds_get_int will swap out bytes
> > for
> > > us if emul_little_endian
> > 
> === message truncated ===
> 
> 
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