There's IBSS / Adhoc support in net80211 and a variety of drivers.
TBD
TBD
WPA-NONE encryption works at the moment:
ap_scan=2
network={
ssid="CACHEBOY_IBSS_ENCRYPT"
psk="xxxxxxxxxxxxxxxx"
# set ibss
mode=1
proto=WPA
key_mgmt=WPA-NONE
pairwise=NONE
group=CCMP
}
WPA-RSN encryption is not yet implemented.
One of the pesky corner cases in 802.11 IBSS is negotiating capabilities between IBSS nodes. Traditionally it wasn't done - you just expected that the remote node supported mostly the same capabilities as you. This is a problem when things like 802.11b versus 802.11bg support - the 802.11bg node may just default / expect that 802.11bg rates are available for all nodes, even the 802.11b node.
How this is supposed to happen is:
FreeBSD doesn't do all of this (it only learns through beacons, broadcast traffic, and receiving probe requests.) This makes various kinds of negotiation difficult.
There's also interoperability with other devices - for example, it looks like the broadcom firmware only treats an IBSS node as 11n enabled if the probe request received by it contains 802.11n IEs.