Re: ipv6 connection hash function wanted ...

2006-11-16 Thread JINMEI Tatuya / 神明達哉
On Tue, 14 Nov 2006 20:20:47 +0100, Max Laier [EMAIL PROTECTED] said: Any ideas? Any papers that deal with this problem? Assuming you don't want to use one of the standard cryptographic ones (which I can imagine being a bit slow for something done per-packet), then one option might be

Re: ipv6 connection hash function wanted ...

2006-11-16 Thread Garrett Cooper
JINMEI Tatuya / wrote: On Tue, 14 Nov 2006 20:20:47 +0100, Max Laier [EMAIL PROTECTED] said: Any ideas? Any papers that deal with this problem? Assuming you don't want to use one of the standard cryptographic ones (which I can imagine being a bit slow for

Re: ipv6 connection hash function wanted ...

2006-11-16 Thread David Malone
On Thu, Nov 16, 2006 at 05:52:32PM +0900, JINMEI Tatuya / [EMAIL PROTECTED]@C#:H wrote: If you want something whose behavior is mathematically guaranteed, I'd recommend universal hashing as already suggested in this thread. Yep - I agree. I'll try and sort something out for Max - it may need

Re: ipv6 connection hash function wanted ...

2006-11-15 Thread Oliver Fromme
Max Laier wrote: David Malone wrote: Assuming you don't want to use one of the standard cryptographic ones (which I can imagine being a bit slow for something done per-packet), then one option might be to use a simpler hash that is keyed. Choose the key at boot/module load time and

Re: ipv6 connection hash function wanted ...

2006-11-15 Thread Oliver Fromme
Oliver Fromme wrote: Max Laier wrote: David Malone wrote: Assuming you don't want to use one of the standard cryptographic ones (which I can imagine being a bit slow for something done per-packet), then one option might be to use a simpler hash that is keyed. Choose the key at

Re: ipv6 connection hash function wanted ...

2006-11-15 Thread Max Laier
On Wednesday 15 November 2006 12:26, Oliver Fromme wrote: Max Laier wrote: David Malone wrote: Assuming you don't want to use one of the standard cryptographic ones (which I can imagine being a bit slow for something done per-packet), then one option might be to use a simpler hash

Re: ipv6 connection hash function wanted ...

2006-11-15 Thread Joerg Sonnenberger
On Wed, Nov 15, 2006 at 01:53:12PM +0100, Max Laier wrote: AFAICT, the attached has this property, but I have no idea if it adds sufficient entropy to the result - it looks like it, though. You should do at least some bit shifting on the arguments as typical ipv6 addresses are by default MAC

Re: ipv6 connection hash function wanted ...

2006-11-15 Thread Oliver Fromme
Max Laier wrote: Oops, I missed one requirement: /* * IMPORTANT: the hash function for dynamic rules must be commutative * in source and destination (ip,port), because rules are bidirectional * and we want to find both in the same bucket. */ OK, then you have to perform a

ipv6 connection hash function wanted ...

2006-11-14 Thread Max Laier
Hello, this one is something for people who know their math. Input: 2x128bit of address (lower ~80bit selectable by user) and 2x16bit of ports (more or less selectable by user). Note that the flow_id is not useable as several broken stack implementations do not set it consistently - and it

Re: ipv6 connection hash function wanted ...

2006-11-14 Thread Paul Twohey
On Tue, 14 Nov 2006, Max Laier wrote: this one is something for people who know their math. Input: 2x128bit of address (lower ~80bit selectable by user) and 2x16bit of ports (more or less selectable by user). Note that the flow_id is not useable as several broken stack implementations do

Re: ipv6 connection hash function wanted ...

2006-11-14 Thread David Malone
On Tue, Nov 14, 2006 at 05:09:20PM +0100, Max Laier wrote: Any ideas? Any papers that deal with this problem? Assuming you don't want to use one of the standard cryptographic ones (which I can imagine being a bit slow for something done per-packet), then one option might be to use a simpler

Re: ipv6 connection hash function wanted ...

2006-11-14 Thread Max Laier
On Tuesday 14 November 2006 20:09, David Malone wrote: On Tue, Nov 14, 2006 at 05:09:20PM +0100, Max Laier wrote: Any ideas? Any papers that deal with this problem? Assuming you don't want to use one of the standard cryptographic ones (which I can imagine being a bit slow for something done