cfg80211: Allow cfg80211_connect_result() errors to be distinguished

Previously, the status parameter to cfg80211_connect_result() was
documented as using WLAN_STATUS_UNSPECIFIED_FAILURE (1) when the real
status code for the failure is not known. This value can be used by an
AP (and often is) and as such, user space cannot distinguish between
explicitly rejected authentication/association and not being able to
even try to associate or not receiving a response from the AP.

Add a new inline function, cfg80211_connect_timeout(), to be used when
the driver knows that the connection attempt failed due to a reason
where connection could not be attempt or no response was received from
the AP. The internal functions now allow a negative status value (-1) to
be used as an indication of this special case. This results in the
NL80211_ATTR_TIMED_OUT to be added to the NL80211_CMD_CONNECT event to
allow user space to determine this case was hit. For backwards
compatibility, NL80211_STATUS_CODE with the value
WLAN_STATUS_UNSPECIFIED_FAILURE is still indicated in the event in such
a case.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
[johannes: fix cfg80211_connect_bss() prototype to use int for status,
 add cfg80211_connect_timeout() to docbook, fix docbook]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index e23d786..8d99531 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -493,7 +493,12 @@
  *	This attribute is ignored if driver does not support roam scan.
  *	It is also sent as an event, with the BSSID and response IEs when the
  *	connection is established or failed to be established. This can be
- *	determined by the STATUS_CODE attribute.
+ *	determined by the %NL80211_ATTR_STATUS_CODE attribute (0 = success,
+ *	non-zero = failure). If %NL80211_ATTR_TIMED_OUT is included in the
+ *	event, the connection attempt failed due to not being able to initiate
+ *	authentication/association or not receiving a response from the AP.
+ *	Non-zero %NL80211_ATTR_STATUS_CODE value is indicated in that case as
+ *	well to remain backwards compatible.
  * @NL80211_CMD_ROAM: request that the card roam (currently not implemented),
  *	sent as an event when the card/driver roamed by itself.
  * @NL80211_CMD_DISCONNECT: drop a given connection; also used to notify