On May 31, 2010, at 6:10 PM, Ondrej Moriš wrote:

> there are some issues when running self-tests on ppc64, it seems to be 
> related to little / big endian - packet checksums are "twisted":
> 
> Example (ikev2fourv.out.diff):
> 
> <     192.168.1.2.500 > 192.168.1.1.500: [bad udp cksum ee7a!] isakmp 2.0 
> msgid 00000000 cookie a88875a8198992a6->0000000000000000: parent_sa 
> ikev2_init[I]:
> ---
> >     192.168.1.2.500 > 192.168.1.1.500: [bad udp cksum 7aee!] isakmp 2.0 
> > msgid 00000000 cookie a88875a8198992a6->0000000000000000: parent_sa 
> > ikev2_init[I]:
> 
> This issue appears on ppc64 only (i.e. i386, x86_64 work fine).

"This issue appears on ppc64 only" and "i386, x86_64 work fine" mean different 
things; not only is there also ppc32, but there are other 32-bit and 64-bit 
architectures on which modern UN*Xes run and on which tcpdump should be able to 
work.

Is this a problem on ppc32?

If so, it's probably a byte-order issue - do you have any other big-endian 
architectures on which to test this (ARM, System/390, 32-bit MIPS, SPARCv7/v8, 
etc. - 32-bit big-endian; z/Architecture, 64-bit MIPS, SPARCv9 - 64-bit 
big-endian)?

If not, it might be a combination of byte-order *and* width; what happens on 
other 64-bit big-endian architectures?

> Could this, possibly, lead to any problems? Is ppc64 architecture supported?

We don't really have an official list of supported architectures.  In any case, 
there's almost certainly nothing PowerPC-specific about this; it's either a 
big-endian vs. little-endian issue (as noted above, there are other big-endian 
architectures supported by, for example, Linux), a combination of that plus a 
64-bit issue (as noted, there are other big-endian 64-bit architectures), a 
compiler issue (which isn't a case of *us* supporting the architecture), or a 
case of incorrect C code that happens to compile to machine code that does the 
right thing with some compilers on some architectures but not on others (again, 
not a case of us supporting or not supporting particular architectures, just a 
bug).


-
This is the tcpdump-workers list.
Visit https://cod.sandelman.ca/ to unsubscribe.

Reply via email to