FreeTDS Development Group

[Michael Peppler <mpeppler AT peppler.org>]

Mark Schaal writes:
 > > 
 > > I think so. And it's similar to the dbsetuserdata() call in the DBlib
 > > side. I think the explanation of the dbsetuserdata() functionality
 > > (and teh deadlock example code that is included there) explains this
 > > functionality well.
 > > 
 > > In DBD::Sybase I definitely expect the buffer returned by the
 > > CS_USERDATA property to be the same buffer that I passed in earlier -
 > > its elements can change and the action I take in the server or client
 > > callbacks depend on those values (typically whether to call a perl
 > > callback from the C error handler or not).
 > > 
 > > Michael
 > 
 > Time to be more precise.  The buffer in this case is a **imp_dbh_st.
 > Do you really want to store the **imp_dbh_st, or just the *imp_dbh_st?
 > By storing the contents of the buffer (*imp_dbh_st) you still get the
 > changes to the actual imp_dbh_st, which I believe is what is desired,
 > but you can't change that around to be some other $dbh.
 > 
 > Clear?  (as mud?)

Yeah. I got confused by the double indirection (as usual :-0)

Anyway - on linux I still core dump on the ct_connect(). The stack
trace gives me:

(gdb) bt
#0  strncpy (s1=0x8192929 "", s2=0x0, n=30) at ../sysdeps/generic/strncpy.c:37
#1  0x2abd9a21 in tds_set_server (tds_login=0x81928b0, server=0x0)
    at login.c:68
#2  0x2abd5e27 in ct_connect (con=0x8127378, servername=0x81aabf8 "", 
    snamelen=0) at ct.c:167
#3  0x2abcbf1a in syb_db_connect ()
#4  0x2abcb75f in syb_db_login ()
#5  0x2abc89a9 in XS_DBD__Sybase__db__login ()
#6  0x8087b7e in Perl_pp_entersub ()
#7  0x80b162e in Perl_runops_standard ()
#8  0x8058e01 in perl_call_sv ()
#9  0x2abbea3c in XS_DBI_dispatch ()
#10 0x8087b7e in Perl_pp_entersub ()
#11 0x80b162e in Perl_runops_standard ()
#12 0x8058791 in perl_run ()
#13 0x8056bdb in main ()

So there seems to be an invalid strcpy going on here - note that I'm
not setting the server to anything, and expect the library to use the
contents of $DSQUERY or, if that is empty, 'SYBASE'.

I'll make a patch in a minute.

Michael
-- 
Michael Peppler         -||-  Data Migrations Inc.
mpeppler AT peppler.org    -||-  http://www.mbay.net/~mpeppler
Int. Sybase User Group  -||-  http://www.isug.com
Sybase on Linux mailing list: ase-linux-list AT isug.com