On Monday 14 April 2008, Tomas Winkler wrote: > On Mon, Apr 14, 2008 at 7:27 PM, Ivo van Doorn <ivdoorn@xxxxxxxxx> wrote: > > Hi, > > > > I've implemented the steps for hardware encryption > > including the part where the IV/EIV is being moved around. > > > > I now have a different problem, the hw_key_idx is u8, > > so is very limited to what can be stored in it. I am trying > > to find a solution for the following problem without increasing > > the size of hw_key_idx since it is also used in the ieee80211_tx_control > > structure which should remain as small as possible to fix in skb->cb. > > > > The problem is as follows: > > rt61pci, rt73usb, rt2800pci and rt2800usb support both shared keys > > as well as pairwise keys. When the "address" argument of set_key() > > is a valid MAC address, then the key is considered to be pairwise, > > otherwise it is a shared key. > > > > rt61pci and rt73usb supports: > > shared keys: 16 (4 per allowed virtual interface) > > pairwise keys: 64 (16 per allowed virtual interface) > > > > rt2800pci and rt2800usb supports: > > shared keys: 32 (4 per allowed virtual interface) > > pairwise keys: 256 (32 per allowed virtual interface) > > > > This means that the hw_key_idx with rt2800 hardware is already > > full when all keys are being supported. I am thinking of adding a flag > > to the key structure and ieee80211_tx_control structure to indicate > > if the key is shared or pairwise. This will safe 1 bit that otherwise has > > to be reserved from the hw_key_idx. > > Do you agree with such a flag addition, or should the driver not care > > about pairwise vs. shared. > > > > But now the fun part begins, the hardware needs the ieee80211_key_alg value > > for encryption (don't ask why, the algorithm is also stored in the register > > so it should be easy for the hardware to look it up directly). > > What should be the best way to obtain this algorithm, should a callback > > function be added, or should the driver keep a list in memory for all > > added keys (which would be memory duplication since mac80211 also > > has it in memory). > > > > Thanks, > > > > > Not sure what was intention for hw_key_idx but currently there are assignment > from key->conf.keyidx to hw_key_idx and visa versa. keyidx is used > for 802.11 key index [1..4] > So it's quit risky to use it for something else That souds like a bug in mac80211 then. hw_key_idx is for internal use for the driver, and mac80211 should never expect the driver to set it to a particular value. Otherwise drivers won't be able to differentiate between keys for particular interfaces, or pairwise keys, which should be supported since mac80211 passes the address argument for a reason ;) Ivo -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
