Supplicant Can't Make a Connection to a WPA Secured Access Point.

[Dan Williams]

On Wed, 2012-10-17 at 13:42 -0500, Jemiah Aitch wrote:
> I have an issue using wpa_supplicant but I can't say for sure if it?s
> a configuration issue or a problem with the kernel it?s running on.
> I?m hoping someone on this might recognize the issue. I?m running
> version wpa_supplicant version 0.7.3 on linux 2.6.37 on the AM3517
> processor (TI SDK 05.05). The published SDK didn't include wireless
> support and I've been adding it for the WL1271L radio. So far I have
> it working well enough that I can connect to an unsecured access point
> using wpa_supplicant but when I try to connect to a WPA secured access
> point there seems to be an error accessing something the supplicant
> needs to complete the connection. I added the -dd option to the
> arguments and ran it in the foreground to catch the following error:
> 
> State: 4WAY_HANDSHAKE -> 4WAY_HANDSHAKE
> WPA: RX message 3 of 4-Way Handshake from 98:fc:11:8c:8b:60 (ver=2)
> WPA: IE KeyData - hexdump(len=72): 30 18 01 00 00 0f ac 02 02 00 00 0f
> ac 04 00 0f ac 02 01 00 00 0f ac 02 0c 00 dd 26 00 0f ac 01 01 00 9b
> 77 dc 4d c7 96 80
> WPA: RSN IE in EAPOL-Key - hexdump(len=26): 30 18 01 00 00 0f ac 02 02
> 00 00 0f ac 04 00 0f ac 02 01 00 00 0f ac 02 0c 00
> WPA: GTK in EAPOL-Key - hexdump(len=40): [REMOVED]
> WPA: Sending EAPOL-Key 4/4
> WPA: TX EAPOL-Key - hexdump(len=99): ?....... (I just chopped this
> off)
> WPA: Installing PTK to the driver.
> wpa_driver_nl80211_set_key: ifindex=5 alg=3 addr=0x65888 key_idx=0
> set_tx=1 seq_len=6 key_len=16
>   addr=98:fc:11:8c:8b:60
> nl80211: set_key failed; err=-2 No such file or directory)
> WPA: Failed to set PTK to the driver (alg=3 keylen=16
> bssid=98:fc:11:8c:8b:60)
> wpa_driver_nl80211_deauthenticate
> [  144.573486] cfg80211: Calling CRDA to update world regulatory
> domain
> 
> Has anyone ever seen an error like this? It looks like something in
> Netlink (set_key) can?t find a file or resource of some kind. If
> anyone has any advice I'd love to hear it.

-2 == ENOENT; which is just a generic POSIX error code.  Most of the
kernel uses these types of error codes; see /usr/include/errno.h or with
glibc, /usr/include/asm-generic/errno-base.h.  ENOENT just means "the
thing you wanted can't be found or doesn't exist".  It actually doesn't
have much to do with files or directories.

What you need to do is jump into cfg80211 and find out why set_key is
failing.  See the kernel sources in net/wireless/nl80211.c where you'll
find:

	{
		.cmd = NL80211_CMD_SET_KEY,
		.doit = nl80211_set_key,
		.policy = nl80211_policy,
		.flags = GENL_ADMIN_PERM,
		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
				  NL80211_FLAG_NEED_RTNL,
	},

so that means the set_key() call from the supplicant ends up in
nl80211_set_key() in the kernel.  What you want to do is figure out what
piece of that function returns ENOENT, and then trace that down and find
out where the error is getting returned.  It might be returned from
stuff in net/mac80211/ or even stuff in the TI driver.

Dan