nl80211/cfg80211: add ap channel switch command

Add NL80211_CMD_AP_CH_SWITCH command which
triggers an AP channel switch process.

Usermode notified about channel switch complete
event with NL80211_CMD_CH_SWITCH_NOTIFY.

Usermode (hostapd) is responsible to update the
channel switch announcement IE in the beacon
prior and after the channel switch operation.

Signed-off-by: Victor Goldenshtein <victorg@ti.com>

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index cede7609e7e34edb0d3a776e67e81b6301a0dfb3..fa07bc03a7ef14e5a0ba5406cb974e59737d13a6 100644 (file)
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -565,6 +565,14 @@
  *     %NL80211_ATTR_IFINDEX is now on %NL80211_ATTR_WIPHY_FREQ with
  *     %NL80211_ATTR_WIPHY_CHANNEL_TYPE.
  *
+* @NL80211_CMD_AP_CH_SWITCH: Perform a channel switch in the driver (for
+ *     AP/GO).
+ *     %NL80211_ATTR_WIPHY_FREQ: new channel frequency.
+ *     %NL80211_ATTR_CH_SWITCH_BLOCK_TX: block tx on the current channel.
+ *     %NL80211_ATTR_CH_SWITCH_POST_BLOCK_TX: block tx on the target channel.
+ *     %NL80211_FREQ_ATTR_CH_SWITCH_COUNT: number of TBTT's until the channel
+ *     switch event.
+ *
  * @NL80211_CMD_SCAN_CANCEL: Stop currently running scan (both sw and hw).
  *     This operation will eventually invoke %NL80211_CMD_SCAN_ABORTED
  *     event, partial scan results will be available. Returns -ENOENT
@@ -728,6 +736,8 @@ enum nl80211_commands {
 
        NL80211_CMD_CH_SWITCH_NOTIFY,
 
+       NL80211_CMD_AP_CH_SWITCH,
+
        /* leave some room for adding nl80211 commands for old kernels */
        NL80211_CMD_SCAN_CANCEL = NL80211_CMD_CH_SWITCH_NOTIFY + 10,
 
@@ -1315,6 +1325,14 @@ enum nl80211_commands {
  * @NL80211_ATTR_ROAMING_DISABLED: indicates that the driver can't do roaming
  *      currently.
  *
+ * @NL80211_ATTR_CH_SWITCH_COUNT: the number of TBTT's until the channel
+ *     switch event
+ * @NL80211_ATTR_CH_SWITCH_BLOCK_TX: block tx on the current channel before the
+ *     channel switch operation.
+ * @NL80211_ATTR_CH_SWITCH_POST_BLOCK_TX: block tx on the target channel after
+ *     the channel switch operation, should be set if the target channel is
+ *     DFS channel.
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -1582,6 +1600,9 @@ enum nl80211_attrs {
        NL80211_ATTR_SCHED_SCAN_NUM_SHORT_INTERVALS,
 
        NL80211_ATTR_ROAMING_DISABLED,
+       NL80211_ATTR_CH_SWITCH_COUNT,
+       NL80211_ATTR_CH_SWITCH_BLOCK_TX,
+       NL80211_ATTR_CH_SWITCH_POST_BLOCK_TX,
 
        /* add attributes here, update the policy in nl80211.c */
 
@@ -3100,12 +3121,14 @@ enum nl80211_ap_sme_features {
  * @NL80211_FEATURE_SCHED_SCAN_INTERVALS: This driver supports using
  *     short interval for sched scan and then switching to a longer
  *     interval.
+ * @NL80211_FEATURE_AP_CH_SWITCH: This driver supports AP channel switch.
  */
 enum nl80211_feature_flags {
        NL80211_FEATURE_SK_TX_STATUS    = 1 << 0,
        NL80211_FEATURE_HT_IBSS         = 1 << 1,
        NL80211_FEATURE_INACTIVITY_TIMER = 1 << 2,
        NL80211_FEATURE_CELL_BASE_REG_HINTS = 1 << 3,
+       NL80211_FEATURE_AP_CH_SWITCH    = 1 << 4,
 
        /* leave room for new feature flags */
        NL80211_FEATURE_SCHED_SCAN_INTERVALS  = 1 << 20,

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index ff28f02eedd91dc1f1a026564210b26bf8dcc841..871cf227fdd255ad289e75888c64f895f7fb5936 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -138,6 +138,34 @@ struct ieee80211_channel {
        int orig_mag, orig_mpwr;
 };
 
+/**
+ * struct ieee80211_ap_ch_switch - holds the ap channel switch data
+ *
+ * The information provided in this structure is required for the ap channel
+ * switch operation.
+ *
+ * @timestamp: value in microseconds of the 64-bit Time Synchronization
+ *     Function (TSF) timer when the frame containing the channel switch
+ *     announcement was received. This is simply the rx.mactime parameter
+ *     the driver passed into mac80211.
+ * @block_tx: Indicates whether transmission must be blocked before the
+ *     scheduled channel switch, as indicated by the AP.
+ * @post_switch_block_tx: Indicates whether transmission must be blocked after
+ *     the scheduled channel switch, this should be set if the target channel
+ *     is DFS channel.
+ * @channel: the new channel to switch to
+ * @channel_type: the type of the new channel
+ * @count: the number of TBTT's until the channel switch event
+ */
+struct ieee80211_ap_ch_switch {
+       u64 timestamp;
+       bool block_tx;
+       bool post_switch_block_tx;
+       struct ieee80211_channel *channel;
+       enum nl80211_channel_type channel_type;
+       u8 count;
+};
+
 /**
  * enum ieee80211_rate_flags - rate flags
  *
@@ -1497,6 +1525,8 @@ struct cfg80211_gtk_rekey_data {
  *     later passes to cfg80211_probe_status().
  *
  * @set_noack_map: Set the NoAck Map for the TIDs.
+ *
+ * @ap_channel_switch: Perform AP channel switch.
  */
 struct cfg80211_ops {
        int     (*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -1699,6 +1729,10 @@ struct cfg80211_ops {
                                  struct cfg80211_wowlan *wowlan);
 
        struct ieee80211_channel *(*get_channel)(struct wiphy *wiphy);
+
+       int     (*ap_channel_switch)(struct wiphy *wiphy,
+                                    struct net_device *dev,
+                                    struct ieee80211_ap_ch_switch *ap_ch_sw);
 };
 
 /*

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 03075590b1d3ce54bf265922809897b05c6c391c..bf3e7194d26b7d8281e810f94fff26dfa17f63cc 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -211,6 +211,9 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
        [NL80211_ATTR_SCHED_SCAN_SHORT_INTERVAL] = { .type = NLA_U32 },
        [NL80211_ATTR_SCHED_SCAN_NUM_SHORT_INTERVALS] = { .type = NLA_U8 },
        [NL80211_ATTR_ROAMING_DISABLED] = { .type = NLA_FLAG },
+       [NL80211_ATTR_CH_SWITCH_COUNT] = { .type = NLA_U32 },
+       [NL80211_ATTR_CH_SWITCH_BLOCK_TX] = { .type = NLA_FLAG },
+       [NL80211_ATTR_CH_SWITCH_POST_BLOCK_TX] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -4099,6 +4102,50 @@ static int nl80211_stop_sched_scan(struct sk_buff *skb,
        return err;
 }
 
+static int nl80211_ap_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];
+       u32 freq = 0;
+       struct ieee80211_ap_ch_switch ap_ch_sw;
+
+       if (!rdev->ops->ap_channel_switch)
+               return -EOPNOTSUPP;
+
+       if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
+           dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
+               return -EOPNOTSUPP;
+
+       if (!info->attrs[NL80211_ATTR_CH_SWITCH_COUNT] ||
+           !info->attrs[NL80211_ATTR_WIPHY_FREQ] ||
+           !info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE])
+               return -EINVAL;
+
+       memset(&ap_ch_sw, 0, sizeof(ap_ch_sw));
+
+       ap_ch_sw.channel_type =
+               nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]);
+       if (ap_ch_sw.channel_type != NL80211_CHAN_HT20)
+               return -EOPNOTSUPP;
+
+       ap_ch_sw.count = nla_get_u32(info->attrs[NL80211_ATTR_CH_SWITCH_COUNT]);
+       freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+
+       ap_ch_sw.channel = ieee80211_get_channel(&rdev->wiphy, freq);
+       if (!ap_ch_sw.channel ||
+           ap_ch_sw.channel->flags & IEEE80211_CHAN_DISABLED)
+               return -EINVAL;
+
+       if (info->attrs[NL80211_ATTR_CH_SWITCH_BLOCK_TX])
+               ap_ch_sw.block_tx = true;
+
+       if (info->attrs[NL80211_ATTR_CH_SWITCH_POST_BLOCK_TX])
+               ap_ch_sw.post_switch_block_tx = true;
+
+       return rdev->ops->ap_channel_switch(&rdev->wiphy, dev, &ap_ch_sw);
+}
+
 static int nl80211_scan_cancel(struct sk_buff *skb, struct genl_info *info)
 {
        return cfg80211_scan_cancel(info->user_ptr[0]);
@@ -6798,6 +6845,14 @@ static struct genl_ops nl80211_ops[] = {
                .internal_flags = NL80211_FLAG_NEED_NETDEV |
                                  NL80211_FLAG_NEED_RTNL,
        },
+       {
+               .cmd = NL80211_CMD_AP_CH_SWITCH,
+               .doit = nl80211_ap_channel_switch,
+               .policy = nl80211_policy,
+               .flags = GENL_ADMIN_PERM,
+               .internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
+                                 NL80211_FLAG_NEED_RTNL,
+       },
 
 };