> -----Original Message----- > From: Jouni Malinen [mailto:j@xxxxx] > Sent: Sunday, February 21, 2016 12:37 > To: Peer, Ilan > Cc: hostap@xxxxxxxxxxxxxxxxxxx; Stern, Avraham > Subject: Re: [PATCH 24/25] MBO: Always accept BTM request with > disassociation imminent bit set > > On Sun, Feb 21, 2016 at 09:19:01AM +0000, Peer, Ilan wrote: > > > From: Jouni Malinen [mailto:j@xxxxx] On Mon, Feb 15, 2016 at > > > 04:53:59PM +0200, Ilan Peer wrote: > > > > According to Multiband Operation specification (r17, section > > > > 3.5.2), a BSS Transition Management Request with the > > > > disassociation imminent bit set should always be accepted. > > > > > > The spec includes an exception for this: "another AP, if one [is] available". > > > Could not find this in the version that I have (v17). What I have states that: > > > > "On receipt of an unsolicited BTM Request frame with a Disassociation > Imminent bit set to one, the MBO STA shall be capable of responding with a > BTM Response frame that shall contain the Status Code field (§ 8.6.14.10 in > [3]) indicating accept. The MBO STA may also include the Target BSSID field (§ > 8.6.14.10 in [3]). When the Disassociation Imminent bit is set to one, the STA > shall not reject the Transition Management Request" > > I'm reviewing this based on the latest draft (r19). Anyway, that "shall not > reject" is there.. Interesting. IMHO, this looks pretty bad requirement and as > such, if it is needed, it will need to be made conditional on CONFIG_MBO (if > not even something stronger; I'm willing to ignore pointless requirements in > the spec in the default behavior). > I'd say the spec should really be modified to not say that, though, since there > is no such requirement in the IEEE 802.11 standard and it does not make any > sense to be forced to accept something that cannot be done. > I've asked our representatives to handle this the WFA, so we can wait for their clarifications/changes on this. > > We were also confused about this :) Maybe the reason for this is that > > as Disassociation Imminent is set the station does not have much choice and > eventually would be disassociated so whether it initiated a transition to one of > the candidates or not does not really matter. > > Sure, but it should be valid behavior for a non-AP STA to wait for the AP to > disconnect it if there are no other options for the non-AP STA to find > alternative connection. Misusing BSS Transition Management frames to cause > disconnection is not really the best approach for something like this since the > AP can already use the standard Deauthentication frame as notification. > Indeed. Looking at this again, this is also actually not compatible with the spec that requires the station to disconnect after accepting the BTM. Thanks, Ilan. _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap
