linux/net/wireless
Johannes Berg f444de05d2 cfg80211/mac80211: better channel handling
Currently (all tested with hwsim) you can do stupid
things like setting up an AP on a certain channel,
then adding another virtual interface and making
that associate on another channel -- this will make
the beaconing to move channel but obviously without
the necessary IEs data update.

In order to improve this situation, first make the
configuration APIs (cfg80211 and nl80211) aware of
multi-channel operation -- we'll eventually need
that in the future anyway. There's one userland API
change and one API addition. The API change is that
now SET_WIPHY must be called with virtual interface
index rather than only wiphy index in order to take
effect for that interface -- luckily all current
users (hostapd) do that. For monitor interfaces, the
old setting is preserved, but monitors are always
slaved to other devices anyway so no guarantees.

The second userland API change is the introduction
of a per virtual interface SET_CHANNEL command, that
hostapd should use going forward to make it easier
to understand what's going on (it can automatically
detect a kernel with this command).

Other than mac80211, no existing cfg80211 drivers
are affected by this change because they only allow
a single virtual interface.

mac80211, however, now needs to be aware that the
channel settings are per interface now, and needs
to disallow (for now) real multi-channel operation,
which is another important part of this patch.

One of the immediate benefits is that you can now
start hostapd to operate on a hardware that already
has a connection on another virtual interface, as
long as you specify the same channel.

Note that two things are left unhandled (this is an
improvement -- not a complete fix):

 * different HT/no-HT modes

   currently you could start an HT AP and then
   connect to a non-HT network on the same channel
   which would configure the hardware for no HT;
   that can be fixed fairly easily

 * CSA

   An AP we're connected to on a virtual interface
   might indicate switching channels, and in that
   case we would follow it, regardless of how many
   other interfaces are operating; this requires
   more effort to fix but is pretty rare after all

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-05-07 14:55:50 -04:00
..
.gitignore wireless: support internal statically compiled regulatory database 2009-12-21 18:56:10 -05:00
Kconfig wireless: remove CONFIG_WIRELESS_OLD_REGULATORY 2009-12-28 16:31:37 -05:00
Makefile wireless: support internal statically compiled regulatory database 2009-12-21 18:56:10 -05:00
chan.c cfg80211/mac80211: better channel handling 2010-05-07 14:55:50 -04:00
core.c cfg80211: Remove default dynamic PS timeout value 2010-04-27 16:09:22 -04:00
core.h cfg80211/mac80211: better channel handling 2010-05-07 14:55:50 -04:00
db.txt wireless: support internal statically compiled regulatory database 2009-12-21 18:56:10 -05:00
debugfs.c cfg80211/mac80211: use debugfs_remove_recursive 2009-10-30 16:49:18 -04:00
debugfs.h cfg80211/mac80211: use debugfs_remove_recursive 2009-10-30 16:49:18 -04:00
ethtool.c cfg80211: add firmware and hardware version to wiphy 2009-10-07 16:39:46 -04:00
ethtool.h net/wireless/ethtool.h: drop unnecessary include of linux/ethtool.h 2009-10-07 16:39:49 -04:00
genregdb.awk wireless: fix comments in genregdb.awk 2009-12-25 16:35:43 -08:00
ibss.c cfg80211/mac80211: better channel handling 2010-05-07 14:55:50 -04:00
lib80211.c lib80211: consolidate crypt init routines 2008-11-21 11:08:17 -05:00
lib80211_crypt_ccmp.c lib80211: Cosmetics - make room for MIC/CRC near the actual calculation 2010-02-02 16:03:38 -05:00
lib80211_crypt_tkip.c lib80211: Introduce TKIP_HDR_LEN define for code clarity 2010-02-02 16:03:38 -05:00
lib80211_crypt_wep.c lib80211: absorb crypto bits from net/ieee80211 2008-11-21 11:08:17 -05:00
mlme.c cfg80211: Add local-state-change-only auth/deauth/disassoc 2010-04-07 14:37:56 -04:00
nl80211.c cfg80211/mac80211: better channel handling 2010-05-07 14:55:50 -04:00
nl80211.h cfg80211: Add connection quality monitoring support to nl80211 2010-03-24 16:02:37 -04:00
radiotap.c wireless: update radiotap parser 2010-02-08 16:50:53 -05:00
reg.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 into merge 2010-04-08 13:34:54 -04:00
reg.h cfg80211: add regulatory hint disconnect support 2010-02-01 15:40:06 -05:00
regdb.h wireless: support internal statically compiled regulatory database 2009-12-21 18:56:10 -05:00
scan.c cfg80211: export cfg80211_find_ie 2010-01-26 11:53:20 -05:00
sme.c cfg80211/mac80211: better channel handling 2010-05-07 14:55:50 -04:00
sysfs.c cfg80211: export multiple MAC addresses in sysfs 2010-01-22 16:11:16 -05:00
sysfs.h [WIRELESS] cfg80211: New wireless config infrastructure. 2007-04-25 22:29:41 -07:00
util.c mac80211: support paged rx SKBs 2010-03-31 14:39:34 -04:00
wext-compat.c cfg80211/mac80211: better channel handling 2010-05-07 14:55:50 -04:00
wext-compat.h cfg80211: validate channel settings across interfaces 2009-08-14 09:13:42 -04:00
wext-core.c net/wireless/wext-core.c: Use IW_EVENT_IDX macro 2010-03-23 16:50:27 -04:00
wext-priv.c wext: refactor 2009-10-07 16:39:43 -04:00
wext-proc.c net: spread __net_init, __net_exit 2010-01-17 19:16:02 -08:00
wext-sme.c cfg80211/mac80211: better channel handling 2010-05-07 14:55:50 -04:00
wext-spy.c wext: refactor 2009-10-07 16:39:43 -04:00