On Sunday 07 July 2002 07.46, Joakim Axelsson wrote:
> res = ((key->sip & 0xF0F0F0F0) >> 4) | ((key->sip & 0x0F0F0F0F) <<
> 4); res *= 0x47441DFB;
> res ^= key->dip ^ key->proto;
> res ^= ((key->dport << 16) | key->sport);
> res ^= 0x57655A7D;
> res ^= (res >> 24);
> res ^= (res >> 8);
>
>
> Now s
2002-07-07 06:23:41+0200, Joakim Axelsson <[EMAIL PROTECTED]> ->
>
> res = ((key->sip & 0xF0F0F0F0) >> 4) | ((key->sip & 0x0F0F0F0F) << 4);
> res *= 0x47441DFB;
> res ^= key->dip ^ key->proto;
> res ^= (key->dport << 16) ^ key->sport;
> res *= 0x57655A7D;
> res ^= (res >> 24);
> res ^= (res >> 8)
2002-07-07 04:30:00+0200, Svenning Sorensen <[EMAIL PROTECTED]> ->
> At 01:16 07-07-2002, Joakim Axelsson wrote:
> >I guess you all are begining to get a little tired of my mails :-). Anyhow
> >on our little misstake what ^ really does in C (should have known better
> >:-). I guess I seldom use xo
At 01:16 07-07-2002, Joakim Axelsson wrote:
>I guess you all are begining to get a little tired of my mails :-). Anyhow
>on our little misstake what ^ really does in C (should have known better
>:-). I guess I seldom use xor in my c-code.) res ^= 0x47441DFB ^ 0x57655A7D
>is kinda of useless then.
2002-07-07 00:41:09+0200, Joakim Axelsson <[EMAIL PROTECTED]> ->
>
> Now to make it even more impossible to attack I added a A,B factor to it:
> "res ^= A ^ B;" Same A and B as in abcd*
>
> static u32 hash_rt_ab(struct ct_key *key)
> {
> u32 res;
>
> PER_HASH_TIMER_1(
>
2002-07-06 23:14:51+0200, Joakim Axelsson <[EMAIL PROTECTED]> ->
>
> Also with this idea of using power of (^), we tested the abcd hash using
> power of instead of just adding the values up:
>
> static u32 hash_abcd_power(struct ct_key *key)
> {
> u32 res;
>
> PER_HASH_TIMER_1(
>
2002-07-06 23:14:51+0200, Joakim Axelsson <[EMAIL PROTECTED]> ->
>
> Me and Martin Josefsson has tested the new cttest-0.2. Martin also took the
> idea of using the hash-function that the routingcache uses in Linux:
>
Some more on this issue. Martin discovered that changing "res ^= (res >>
16);"
2002-07-06 17:23:42+0200, Patrick Schaaf <[EMAIL PROTECTED]> ->
> Hi all,
>
> I have released http://bei.bof.de/cttest-0.2.tar.gz. It is now easier
> to modify the list of sizes and hashes that should be plotted, and
> there's timing code for the hash functions, together with average
> used list
Hi all,
I have released http://bei.bof.de/cttest-0.2.tar.gz. It is now easier
to modify the list of sizes and hashes that should be plotted, and
there's timing code for the hash functions, together with average
used list length analysis.
> Actually, I now have this nice <128-byte-icache snippet
> > if (hashsize%2 == 0)
> > hashsize--;
>
> Just so you don't underestimate a requirement ... :-)
Underestimating is desirable here. User gives upper bound - observe it!
> (assume we are checking positive numbers ;-)
We are, the variable in question, is unsigned.
Actually, I now have thi
> 2002-07-05 18:54:15+0200, Patrick Schaaf <[EMAIL PROTECTED]> ->
>>
>> - make the hash bucket count at least individible by 2. This should go
>> as a strong suggestion into the documentation, and should be
>> implemented in the default initialization code. Anybody volunteering
>> for one o
2002-07-05 18:54:15+0200, Patrick Schaaf <[EMAIL PROTECTED]> ->
>
> - make the hash bucket count at least individible by 2. This should go
> as a strong suggestion into the documentation, and should be implemented
> in the default initialization code. Anybody volunteering for one or
> the o
Martin, Joakim,
thank you for your cttest runs. They both provide new data points,
coming from a router instead of a server. They confirm that we should
at least strongly avoid even hash bucket counts. In all examples we have
now, both the original hash, and Don's abcd hash detoriate badly.
The
2002-07-03 06:15:02+0200, Joakim Axelsson <[EMAIL PROTECTED]> ->
>
> I collected this data 5am during absolut low time. I'll try again later
> at primetime :-)
>
Here is a new stat with about 85K entries:
http://aaricia.hemmet.chalmers.se/~gozem/cttest-2002-07-05_1739/
Look at the 131072 origi
Hi,
I've also done some plotting.
about 400 student-machines behind router, it's summer now so there's not
as much traffic as the rest of the year, only ~28k entries.
hashsize is 16384 with default ip_conntrack_max of 131072.
http://gandalf.hjorten.nu/kna-gw/
I added 16384 as size in ctreport
2002-07-02 23:52:06+0200, Patrick Schaaf <[EMAIL PROTECTED]> ->
> Hi all,
>
> I have put a tarball at http://bei.bof.de/cttest-0.1.tar.gz
> Unpack, look at README, and reproduce the gnuplot pictures I have
> mentioned earlier today (at http://bei.bof.de/ex1/)
>
&g
Hi all,
I have put a tarball at http://bei.bof.de/cttest-0.1.tar.gz
Unpack, look at README, and reproduce the gnuplot pictures I have
mentioned earlier today (at http://bei.bof.de/ex1/)
I would love to see results from other kinds of workloads.
thanks in advance
Patrick
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