I actually would like to see this publicly available for other layers. The rationale is that I would use such a function in RPL, where I need to add an ipv6 address to the interface (prefix given during runtime). Maybe with some more abstractions so that I do not have to deal with hardware addresses in RPL (:

The problem is that it is not really specified anywhere that this is the general way to do it... This function basically assumes that the address is either an EUI-64, a MAC-48, one of the short address representations of IEEE 802.15.4 (with PAN or without), or the 1-bit format we used with the cc1100 in the old stack. This is however by no means generally applicable.

Just out of curiosity: what do you need the link-layer addresses in RPL for?

RPL has an option to spread a prefix via control packets (very similar to the PIO of ND). Nodes receiving this prefix should use it to configure an ipv6 address on their interface.

I thought I can use the interface id to create a unique ipv6 address out of that prefix. Do you have any other suggestions how I can achieve this?

Regardless of this issue (which is pretty complex, because it also includes how to auto-initialize addresses in general) we should really talk about this option, especially with regard to substitutable features in 6LoWPAN ND which I'm currently working on. Are you at the Institute or the Hack'n'ACK today?

I am not at the institute right now, but I'll join the Hack'n'ACK later

Can we order the cases?

That would mean more code.

If I'm not mistaken

case 8:
...
break;
case 6:
...
break;
case 4:
...
case 2:
...
case 1:
...
break;
default:
...

should result in the same code.