2013-02-11 14:46:26

by Johannes Berg

[permalink] [raw]
Subject: [RFC 1/2] cfg80211: advertise extended capabilities to userspace

From: Johannes Berg <[email protected]>

In many cases, userspace may need to know which of the
extended capabilities are implemented in the driver or
device, to include them e.g. in beacons, association
request/response or other frames. Add a new nl80211
attribute that holds the extended capabilities bitmap
supported by the driver/device for this.

Signed-off-by: Johannes Berg <[email protected]>
---
include/net/cfg80211.h | 7 +++++++
include/uapi/linux/nl80211.h | 5 +++++
net/wireless/nl80211.c | 6 ++++++
3 files changed, 18 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index bc670b2..04801f4 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2463,6 +2463,10 @@ struct wiphy_wowlan_support {
*
* @max_acl_mac_addrs: Maximum number of MAC addresses that the device
* supports for ACL.
+ *
+ * @extended_capabilities: extended capabilities supported by the driver,
+ * additional capabilities might be supported by userspace
+ * @extended_capabilities_len: length of the extended capabilities
*/
struct wiphy {
/* assign these fields before you register the wiphy */
@@ -2529,6 +2533,9 @@ struct wiphy {
*/
u32 probe_resp_offload;

+ const u8 *extended_capabilities;
+ u8 extended_capabilities_len;
+
/* If multiple wiphys are registered and you're handed e.g.
* a regular netdev with assigned ieee80211_ptr, you won't
* know whether it points to a wiphy your driver has registered
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 1ed7e1c..e0b6424 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1342,6 +1342,9 @@ enum nl80211_commands {
* number of MAC addresses that a device can support for MAC
* ACL.
*
+ * @NL80211_ATTR_EXT_CAPA: Extended capabilities that the kernel driver
+ * has and handles. The format is the same as the IE contents.
+ *
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
@@ -1620,6 +1623,8 @@ enum nl80211_attrs {

NL80211_ATTR_MAC_ACL_MAX,

+ NL80211_ATTR_EXT_CAPA,
+
/* add attributes here, update the policy in nl80211.c */

__NL80211_ATTR_AFTER_LAST,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b19c822..86a982b 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1354,6 +1354,12 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 portid, u32 seq, int flag
dev->wiphy.max_acl_mac_addrs))
goto nla_put_failure;

+ if (dev->wiphy.extended_capabilities &&
+ nla_put(msg, NL80211_ATTR_EXT_CAPA,
+ dev->wiphy.extended_capabilities_len,
+ dev->wiphy.extended_capabilities))
+ goto nla_put_failure;
+
return genlmsg_end(msg, hdr);

nla_put_failure:
--
1.8.0



2013-02-12 13:58:07

by Johannes Berg

[permalink] [raw]
Subject: Re: [RFC 1/2] cfg80211: advertise extended capabilities to userspace

On Tue, 2013-02-12 at 15:57 +0200, Kalle Valo wrote:
> Johannes Berg <[email protected]> writes:
>
> > From: Johannes Berg <[email protected]>
> >
> > In many cases, userspace may need to know which of the
> > extended capabilities are implemented in the driver or
> > device, to include them e.g. in beacons, association
> > request/response or other frames. Add a new nl80211
> > attribute that holds the extended capabilities bitmap
> > supported by the driver/device for this.
>
> [...]
>
> > + * @extended_capabilities: extended capabilities supported by the driver,
> > + * additional capabilities might be supported by userspace
> > + * @extended_capabilities_len: length of the extended capabilities
>
> FWIW, when I first looked at the patch I wasn't sure if you were
> referring to 802.11 or nl80211 capabilities. I assumed the former. But
> clarifying that in the documentation would be good.

Makes sense, will do that.

johannes


2013-02-12 13:57:20

by Kalle Valo

[permalink] [raw]
Subject: Re: [RFC 1/2] cfg80211: advertise extended capabilities to userspace

Johannes Berg <[email protected]> writes:

> From: Johannes Berg <[email protected]>
>
> In many cases, userspace may need to know which of the
> extended capabilities are implemented in the driver or
> device, to include them e.g. in beacons, association
> request/response or other frames. Add a new nl80211
> attribute that holds the extended capabilities bitmap
> supported by the driver/device for this.

[...]

> + * @extended_capabilities: extended capabilities supported by the driver,
> + * additional capabilities might be supported by userspace
> + * @extended_capabilities_len: length of the extended capabilities

FWIW, when I first looked at the patch I wasn't sure if you were
referring to 802.11 or nl80211 capabilities. I assumed the former. But
clarifying that in the documentation would be good.

--
Kalle Valo

2013-02-11 15:26:01

by Johannes Berg

[permalink] [raw]
Subject: Re: [RFC 1/2] cfg80211: advertise extended capabilities to userspace

On Mon, 2013-02-11 at 15:46 +0100, Johannes Berg wrote:

> + * @NL80211_ATTR_EXT_CAPA: Extended capabilities that the kernel driver
> + * has and handles. The format is the same as the IE contents.

Jouni pointed out that it'd be safer to also have a mask (for those
multi-bit fields that are coming into this ...) so I've made that
change.

johannes


2013-02-11 14:46:27

by Johannes Berg

[permalink] [raw]
Subject: [RFC 2/2] mac80211: advertise operating mode notification capability

From: Johannes Berg <[email protected]>

Use the new extended capabilities advertising to advertise
the fact that operating mode notification is supported.

Signed-off-by: Johannes Berg <[email protected]>
---
include/linux/ieee80211.h | 2 ++
net/mac80211/main.c | 8 ++++++++
2 files changed, 10 insertions(+)

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 4aed928..9164c45 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1788,6 +1788,8 @@ enum ieee80211_tdls_actioncode {
#define WLAN_EXT_CAPA5_TDLS_ENABLED BIT(5)
#define WLAN_EXT_CAPA5_TDLS_PROHIBITED BIT(6)

+#define WLAN_EXT_CAPA8_OPMODE_NOTIF BIT(6)
+
/* TDLS specific payload type in the LLC/SNAP header */
#define WLAN_TDLS_SNAP_RFTYPE 0x2

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 38b3468..453865f 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -501,6 +501,11 @@ static const struct ieee80211_ht_cap mac80211_ht_capa_mod_mask = {
},
};

+static const u8 extended_capabilities[] = {
+ 0, 0, 0, 0, 0, 0, 0,
+ WLAN_EXT_CAPA8_OPMODE_NOTIF,
+};
+
struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
const struct ieee80211_ops *ops)
{
@@ -557,6 +562,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
WIPHY_FLAG_REPORTS_OBSS |
WIPHY_FLAG_OFFCHAN_TX;

+ wiphy->extended_capabilities = extended_capabilities;
+ wiphy->extended_capabilities_len = ARRAY_SIZE(extended_capabilities);
+
if (ops->remain_on_channel)
wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;

--
1.8.0