Re: [PATCH 11/16] cfg80211: introduce TDLS channel switch commands

[Arend van Spriel <arend@broadcom.com>]

On 11/09/14 17:50, Arik Nemtsov wrote:
> Introduce commands to initiate and cancel TDLS channel-switching. Once
> TDLS channel-switching is started, the lower level driver is responsible
> for continually initiating channel-switch operations and returning to
> the base (AP) channel to listen for beacons from time to time.
>
> Upon cancellation of the channel-switch all communication between the
> relevant TDLS peers will continue on the base channel.
>
> Signed-off-by: Arik Nemtsov<arikx.nemtsov@intel.com>
> Reviewed-by: Johannes Berg<johannes.berg@intel.com>
> Signed-off-by: Arik Nemtsov<arik@wizery.com>
> ---
>   include/net/cfg80211.h       |   8 ++++
>   include/net/cfg80211.h.rej   |  15 ++++++

Seems something went haywire here or do you really want to add a .rej 
file in this patch?

Regards,
Arend

>   include/uapi/linux/nl80211.h |  17 +++++++
>   net/wireless/core.c          |   4 ++
>   net/wireless/nl80211.c       | 108 +++++++++++++++++++++++++++++++++++++++++++
>   net/wireless/rdev-ops.h      |  24 ++++++++++
>   net/wireless/trace.h         |  42 +++++++++++++++++
>   7 files changed, 218 insertions(+)
>   create mode 100644 include/net/cfg80211.h.rej
>
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index 5c3acd0..62cdac0 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -2622,6 +2622,14 @@ struct cfg80211_ops {
>   			     u16 admitted_time);
>   	int	(*del_tx_ts)(struct wiphy *wiphy, struct net_device *dev,
>   			     u8 tsid, const u8 *peer);
> +
> +	int	(*tdls_channel_switch)(struct wiphy *wiphy,
> +				       struct net_device *dev,
> +				       const u8 *addr, u8 oper_class,
> +				       struct cfg80211_chan_def *chandef);
> +	void	(*tdls_cancel_channel_switch)(struct wiphy *wiphy,
> +					      struct net_device *dev,
> +					      const u8 *addr);
>   };
>
>   /*
> diff --git a/include/net/cfg80211.h.rej b/include/net/cfg80211.h.rej
> new file mode 100644
> index 0000000..44fd4a9c
> --- /dev/null
> +++ b/include/net/cfg80211.h.rej
> @@ -0,0 +1,15 @@
> +--- include/net/cfg80211.h
> ++++ include/net/cfg80211.h
> +@@ -2331,6 +2331,12 @@
> +  *	with the peer followed by immediate teardown when the addition is later
> +  *	rejected)
> +  * @del_tx_ts: remove an existing TX TS
> ++ *
> ++ * @tdls_channel_switch: Start channel-switching with a TDLS peer. The driver
> ++ *	is responsible for continually initiating channel-switching operations
> ++ *	and returning to the base channel for communication with the AP.
> ++ * @tdls_cancel_channel_switch: Stop channel-switching with a TDLS peer. Both
> ++ *	peers must be on the base channel when the call completes.
> +  */
> + struct cfg80211_ops {
> + 	int	(*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
> diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
> index e7f01d6..c2df1e0 100644
> --- a/include/uapi/linux/nl80211.h
> +++ b/include/uapi/linux/nl80211.h
> @@ -751,6 +751,18 @@
>    * @NL80211_CMD_LEAVE_OCB: Leave the OCB network -- no special arguments, the
>    *	network is determined by the network interface.
>    *
> + * @NL80211_CMD_TDLS_CHANNEL_SWITCH: Start channel-switching with a TDLS peer,
> + *	identified by the %NL80211_ATTR_MAC parameter. A target channel is
> + *	provided via %NL80211_ATTR_WIPHY_FREQ and other attributes determining
> + *	channel width/type. The target operating class is given via
> + *	%NL80211_ATTR_OPER_CLASS.
> + *	The driver is responsible for continually initiating channel-switching
> + *	operations and returning to the base channel for communication with the
> + *	AP.
> + * @NL80211_CMD_TDLS_CANCEL_CHANNEL_SWITCH: Stop channel-switching with a TDLS
> + *	peer given by %NL80211_ATTR_MAC. Both peers must be on the base channel
> + *	when this command completes.
> + *
>    * @NL80211_CMD_MAX: highest used command number
>    * @__NL80211_CMD_AFTER_LAST: internal use
>    */
> @@ -930,6 +942,9 @@ enum nl80211_commands {
>   	NL80211_CMD_JOIN_OCB,
>   	NL80211_CMD_LEAVE_OCB,
>
> +	NL80211_CMD_TDLS_CHANNEL_SWITCH,
> +	NL80211_CMD_TDLS_CANCEL_CHANNEL_SWITCH,
> +
>   	/* add new commands above here */
>
>   	/* used to define NL80211_CMD_MAX below */
> @@ -2008,6 +2023,8 @@ enum nl80211_attrs {
>
>   	NL80211_ATTR_SMPS_MODE,
>
> +	NL80211_ATTR_OPER_CLASS,
> +
>   	/* add attributes here, update the policy in nl80211.c */
>
>   	__NL80211_ATTR_AFTER_LAST,
> diff --git a/net/wireless/core.c b/net/wireless/core.c
> index a4d2792..4c2e501 100644
> --- a/net/wireless/core.c
> +++ b/net/wireless/core.c
> @@ -541,6 +541,10 @@ int wiphy_register(struct wiphy *wiphy)
>   		    !wiphy->wowlan->tcp))
>   		return -EINVAL;
>   #endif
> +	if (WARN_ON((wiphy->features&  NL80211_FEATURE_TDLS_CHANNEL_SWITCH)&&
> +		    (!rdev->ops->tdls_channel_switch ||
> +		     !rdev->ops->tdls_cancel_channel_switch)))
> +		return -EINVAL;
>
>   	if (WARN_ON(wiphy->coalesce&&
>   		(!wiphy->coalesce->n_rules ||
> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
> index 24549cb..328c45b 100644
> --- a/net/wireless/nl80211.c
> +++ b/net/wireless/nl80211.c
> @@ -9658,6 +9658,98 @@ static int nl80211_del_tx_ts(struct sk_buff *skb, struct genl_info *info)
>   	return err;
>   }
>
> +static int nl80211_tdls_channel_switch(struct sk_buff *skb,
> +				       struct genl_info *info)
> +{
> +	struct cfg80211_registered_device *rdev = info->user_ptr[0];
> +	struct net_device *dev = info->user_ptr[1];
> +	struct wireless_dev *wdev = dev->ieee80211_ptr;
> +	struct cfg80211_chan_def chandef = {};
> +	const u8 *addr;
> +	u8 oper_class;
> +	int err;
> +
> +	if (!rdev->ops->tdls_channel_switch ||
> +	    !(rdev->wiphy.features&  NL80211_FEATURE_TDLS_CHANNEL_SWITCH))
> +		return -EOPNOTSUPP;
> +
> +	switch (dev->ieee80211_ptr->iftype) {
> +	case NL80211_IFTYPE_STATION:
> +	case NL80211_IFTYPE_P2P_CLIENT:
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (!info->attrs[NL80211_ATTR_MAC] ||
> +	    !info->attrs[NL80211_ATTR_OPER_CLASS])
> +		return -EINVAL;
> +
> +	err = nl80211_parse_chandef(rdev, info,&chandef);
> +	if (err)
> +		return err;
> +
> +	/*
> +	 * Don't allow wide channels on the 2.4Ghz band, as per IEEE802.11-2012
> +	 * section 10.22.6.2.1. Disallow 5/10Mhz channels as well for now, the
> +	 * specification is not defined for them.
> +	 */
> +	if (chandef.chan->band == IEEE80211_BAND_2GHZ&&
> +	    chandef.width != NL80211_CHAN_WIDTH_20_NOHT&&
> +	    chandef.width != NL80211_CHAN_WIDTH_20)
> +		return -EINVAL;
> +
> +	/* we will be active on the TDLS link */
> +	if (!cfg80211_reg_can_beacon(&rdev->wiphy,&chandef, wdev->iftype))
> +		return -EINVAL;
> +
> +	/* don't allow switching to DFS channels */
> +	if (cfg80211_chandef_dfs_required(wdev->wiphy,&chandef, wdev->iftype))
> +		return -EINVAL;
> +
> +	addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
> +	oper_class = nla_get_u8(info->attrs[NL80211_ATTR_OPER_CLASS]);
> +
> +	wdev_lock(wdev);
> +	err = rdev_tdls_channel_switch(rdev, dev, addr, oper_class,&chandef);
> +	wdev_unlock(wdev);
> +
> +	return err;
> +}
> +
> +static int nl80211_tdls_cancel_channel_switch(struct sk_buff *skb,
> +					      struct genl_info *info)
> +{
> +	struct cfg80211_registered_device *rdev = info->user_ptr[0];
> +	struct net_device *dev = info->user_ptr[1];
> +	struct wireless_dev *wdev = dev->ieee80211_ptr;
> +	const u8 *addr;
> +
> +	if (!rdev->ops->tdls_channel_switch ||
> +	    !rdev->ops->tdls_cancel_channel_switch ||
> +	    !(rdev->wiphy.features&  NL80211_FEATURE_TDLS_CHANNEL_SWITCH))
> +		return -EOPNOTSUPP;
> +
> +	switch (dev->ieee80211_ptr->iftype) {
> +	case NL80211_IFTYPE_STATION:
> +	case NL80211_IFTYPE_P2P_CLIENT:
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (!info->attrs[NL80211_ATTR_MAC])
> +		return -EINVAL;
> +
> +	addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
> +
> +	wdev_lock(wdev);
> +	rdev_tdls_cancel_channel_switch(rdev, dev, addr);
> +	wdev_unlock(wdev);
> +
> +	return 0;
> +}
> +
>   #define NL80211_FLAG_NEED_WIPHY		0x01
>   #define NL80211_FLAG_NEED_NETDEV	0x02
>   #define NL80211_FLAG_NEED_RTNL		0x04
> @@ -10456,6 +10548,22 @@ static const struct genl_ops nl80211_ops[] = {
>   		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
>   				  NL80211_FLAG_NEED_RTNL,
>   	},
> +	{
> +		.cmd = NL80211_CMD_TDLS_CHANNEL_SWITCH,
> +		.doit = nl80211_tdls_channel_switch,
> +		.policy = nl80211_policy,
> +		.flags = GENL_ADMIN_PERM,
> +		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
> +				  NL80211_FLAG_NEED_RTNL,
> +	},
> +	{
> +		.cmd = NL80211_CMD_TDLS_CANCEL_CHANNEL_SWITCH,
> +		.doit = nl80211_tdls_cancel_channel_switch,
> +		.policy = nl80211_policy,
> +		.flags = GENL_ADMIN_PERM,
> +		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
> +				  NL80211_FLAG_NEED_RTNL,
> +	},
>   };
>
>   /* notification functions */
> diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
> index 1b3864c..35cfb71 100644
> --- a/net/wireless/rdev-ops.h
> +++ b/net/wireless/rdev-ops.h
> @@ -993,4 +993,28 @@ rdev_del_tx_ts(struct cfg80211_registered_device *rdev,
>   	return ret;
>   }
>
> +static inline int
> +rdev_tdls_channel_switch(struct cfg80211_registered_device *rdev,
> +			 struct net_device *dev, const u8 *addr,
> +			 u8 oper_class, struct cfg80211_chan_def *chandef)
> +{
> +	int ret;
> +
> +	trace_rdev_tdls_channel_switch(&rdev->wiphy, dev, addr, oper_class,
> +				       chandef);
> +	ret = rdev->ops->tdls_channel_switch(&rdev->wiphy, dev, addr,
> +					     oper_class, chandef);
> +	trace_rdev_return_int(&rdev->wiphy, ret);
> +	return ret;
> +}
> +
> +static inline void
> +rdev_tdls_cancel_channel_switch(struct cfg80211_registered_device *rdev,
> +				struct net_device *dev, const u8 *addr)
> +{
> +	trace_rdev_tdls_cancel_channel_switch(&rdev->wiphy, dev, addr);
> +	rdev->ops->tdls_cancel_channel_switch(&rdev->wiphy, dev, addr);
> +	trace_rdev_return_void(&rdev->wiphy);
> +}
> +
>   #endif /* __CFG80211_RDEV_OPS */
> diff --git a/net/wireless/trace.h b/net/wireless/trace.h
> index 277a85d..f0545e1 100644
> --- a/net/wireless/trace.h
> +++ b/net/wireless/trace.h
> @@ -2032,6 +2032,48 @@ TRACE_EVENT(rdev_del_tx_ts,
>   		  WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(peer), __entry->tsid)
>   );
>
> +TRACE_EVENT(rdev_tdls_channel_switch,
> +	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
> +		 const u8 *addr, u8 oper_class,
> +		 struct cfg80211_chan_def *chandef),
> +	TP_ARGS(wiphy, netdev, addr, oper_class, chandef),
> +	TP_STRUCT__entry(
> +		WIPHY_ENTRY
> +		NETDEV_ENTRY
> +		MAC_ENTRY(addr)
> +		__field(u8, oper_class)
> +		CHAN_DEF_ENTRY
> +	),
> +	TP_fast_assign(
> +		WIPHY_ASSIGN;
> +		NETDEV_ASSIGN;
> +		MAC_ASSIGN(addr, addr);
> +		CHAN_DEF_ASSIGN(chandef);
> +	),
> +	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " MAC_PR_FMT
> +		  " oper class %d, " CHAN_DEF_PR_FMT,
> +		  WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(addr),
> +		  __entry->oper_class, CHAN_DEF_PR_ARG)
> +);
> +
> +TRACE_EVENT(rdev_tdls_cancel_channel_switch,
> +	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
> +		 const u8 *addr),
> +	TP_ARGS(wiphy, netdev, addr),
> +	TP_STRUCT__entry(
> +		WIPHY_ENTRY
> +		NETDEV_ENTRY
> +		MAC_ENTRY(addr)
> +	),
> +	TP_fast_assign(
> +		WIPHY_ASSIGN;
> +		NETDEV_ASSIGN;
> +		MAC_ASSIGN(addr, addr);
> +	),
> +	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " MAC_PR_FMT,
> +		  WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(addr))
> +);
> +
>   /*************************************************************
>    *	     cfg80211 exported functions traces		     *
>    *************************************************************/