Re: Nping/gthostbynameCached

["Luis M." <luis.mgarc () gmail com>]

Hi Gisle,

I've been having a look at the problem you reported but I don't see any
problem with the code. In my box it works. Can you please run nping with
the "-d9" flag and email the output it produces? Also, if you can, run
it through valgrind and attach the output.

It's weird because the only thing that gethostbynameCached() does is to
make deep copies of the hostent struct returned by gethostbyname() and
return those copies in case of duplicate calls.

However, valgrind is complaining about the way we are doing this. I'll
have a deeper look into it and let you know.

Luis MartinGarcia.

==28798==  Address 0x5d68f90 is 0 bytes after a block of size 48 alloc'd
==28798==    at 0x4C24477: calloc (vg_replace_malloc.c:418)
==28798==    by 0x426F75: safe_zalloc (in /usr/local/bin/nping)
==28798==    by 0x41C50E: hostentcpy(hostent*) (in /usr/local/bin/nping)
==28798==    by 0x41C65E: gethostbynameCached(char*) (in
/usr/local/bin/nping)
==28798==    by 0x410A09: TargetGroup::parse_expr(char const*, int) (in
/usr/local/bin/nping)
==28798==    by 0x423114:
NpingTargets::getNextTargetAddressAndName(sockaddr_storage*, unsigned
long*, char*, unsigned long) (in /usr/local/bin/nping)
==28798==    by 0x423543: NpingTargets::processSpecs() (in
/usr/local/bin/nping)
==28798==    by 0x415AE1: main (in /usr/local/bin/nping)
==28798==





Gisle Vanem wrote:
> Something is seriously wrong with the function gethostbynameCached().
> When I use nping with an IP-address everything works fine. But it crashes
> on the first hostname. A quick fix for me, is to revert to
> gethostbyname()
> in common_modified.cc / 436.
>
> Just a FYI.
>
> --gv
>
> For every credibility gap, there is a gullibility fill.
> _______________________________________________
> Sent through the nmap-dev mailing list
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