RRD server mode fails (chroot)

[human]

Not sure whether this is a packaging problem or a rrdtool bug... I've opened a Debian bug as well ( http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=496847)

After upgrading from rrdtool 1.2.28 to rrdtool 1.3.1 the RRD server mode does not work anymore, it claims that chroot failed with errno=2.

rrdtool 1.2.28:

# rrdtool - /tmp
?
RRDtool 1.2.28  Copyright 1997-2008 by Tobias Oetiker <tobi@oetiker.ch>
[...]

rrdtool 1.3.1:

# rrdtool - /tmp
ERROR: can't change root to '/tmp' errno=2
#

Last calls in strace:

chroot("/tmp")                          = 0
write(2, "ERROR: can\'t change root to \'/tm"..., 43ERROR: can't change root
to '/tmp' errno=2

[human]

The code doesn't appear to be changed between 1.2 and 1.3 (apart of indentation)

chroot(argv[2]); 
if (errno != 0) { 
    fprintf(stderr, 
         "ERROR: can't change root to '%s' errno=%d\n", 
         argv[2], errno); 
[...]

If I understand chroot(2) correctly errno is set only if an error occured (chroot(...) != 0). I guess errno is set from a previous syscall and incorrectly evaluated here. Same is true for the chdir() call a few lines below.

The attached patch fixes the problem for me.

[human]

Proposed patch

[oetiker]

Berni,

thanks ! indeed, that code is just broken. Did some more fixing while I was at it: r1471. cheers tobi

[oetiker]

fixed in 1.2 branche too r1472