To allow channel switch announcements within beacons, add
the channel switch command to nl80211/cfg80211. This is
implementation is intended for AP and (later) IBSS mode.
Signed-off-by: Simon Wunderlich <siwu@xxxxxxxxxxxxxxxxxx>
---
include/net/cfg80211.h | 4 +++
include/uapi/linux/nl80211.h | 20 +++++++++++
net/wireless/nl80211.c | 76 +++++++++++++++++++++++++++++++++++++++++-
3 files changed, 99 insertions(+), 1 deletion(-)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index f46ac71..d7afb1f 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2257,6 +2257,10 @@ struct cfg80211_ops {
u16 duration);
void (*crit_proto_stop)(struct wiphy *wiphy,
struct wireless_dev *wdev);
+ int (*channel_switch)(struct wiphy *wiphy,
+ struct net_device *dev,
+ struct cfg80211_chan_def *chandef,
+ bool block_tx, u32 count);
};
/*
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index b484307..f9b168b 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -648,6 +648,16 @@
* @NL80211_CMD_CRIT_PROTOCOL_STOP: Indicates the connection reliability can
* return back to normal.
*
+ * @NL80211_CMD_CHANNEL_SWITCH: Perform a channel switch by announcing the
+ * the new channel information (Channel Switch Announcement - CSA)
+ * in the beacon for some time (as defined in the
+ * %NL80211_ATTR_CH_SWITCH_COUNT parameter) and then change to the
+ * new channel. Userspace provides the new channel information (using
+ * %NL80211_ATTR_WIPHY_FREQ and the attributes determining channel
+ * width). %NL80211_ATTR_CH_SWITCH_BLOCK_TX may be supplied to inform
+ * other station that transmission must be blocked until the channel
+ * switch is complete.
+ *
* @NL80211_CMD_MAX: highest used command number
* @__NL80211_CMD_AFTER_LAST: internal use
*/
@@ -810,6 +820,7 @@ enum nl80211_commands {
NL80211_CMD_CRIT_PROTOCOL_START,
NL80211_CMD_CRIT_PROTOCOL_STOP,
+ NL80211_CMD_CHANNEL_SWITCH,
/* add new commands above here */
/* used to define NL80211_CMD_MAX below */
@@ -1431,6 +1442,12 @@ enum nl80211_commands {
* @NL80211_ATTR_MAX_CRIT_PROT_DURATION: duration in milliseconds in which
* the connection should have increased reliability (u16).
*
+ * @NL80211_ATTR_CH_SWITCH_COUNT: u32 attribute specifying the number of TBTT's
+ * until the channel switch event.
+ * @NL80211_ATTR_CH_SWITCH_BLOCK_TX: flag attribute specifying that transmission
+ * must be blocked on the current channel (before the channel switch
+ * operation).
+ *
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
@@ -1729,6 +1746,9 @@ enum nl80211_attrs {
NL80211_ATTR_CRIT_PROT_ID,
NL80211_ATTR_MAX_CRIT_PROT_DURATION,
+ NL80211_ATTR_CH_SWITCH_COUNT,
+ NL80211_ATTR_CH_SWITCH_BLOCK_TX,
+
/* 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 9cdcd9e..63920db 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -378,6 +378,8 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
[NL80211_ATTR_MDID] = { .type = NLA_U16 },
[NL80211_ATTR_IE_RIC] = { .type = NLA_BINARY,
.len = IEEE80211_MAX_DATA_LEN },
+ [NL80211_ATTR_CH_SWITCH_COUNT] = { .type = NLA_U32 },
+ [NL80211_ATTR_CH_SWITCH_BLOCK_TX] = { .type = NLA_FLAG },
};
/* policy for the key attributes */
@@ -5598,6 +5600,70 @@ err_locked:
return err;
}
+static int nl80211_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;
+ bool block_tx = false;
+ u8 radar_detect_width = 0;
+ u32 count;
+ int err;
+
+ if (!rdev->ops->channel_switch)
+ return -EOPNOTSUPP;
+
+ /* may add IBSS support later */
+ if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
+ dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
+ return -EOPNOTSUPP;
+
+ if (!info->attrs[NL80211_ATTR_WIPHY_FREQ] ||
+ !info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE] ||
+ !info->attrs[NL80211_ATTR_CH_SWITCH_COUNT])
+ return -EINVAL;
+
+ /* useless if AP is not running */
+ if (!wdev->beacon_interval)
+ return -EINVAL;
+
+ err = nl80211_parse_chandef(rdev, info, &chandef);
+ if (err)
+ return err;
+
+ if (!cfg80211_reg_can_beacon(&rdev->wiphy, &chandef))
+ return -EINVAL;
+
+ err = cfg80211_chandef_dfs_required(wdev->wiphy, &chandef);
+ if (err < 0)
+ return err;
+
+ if (err)
+ radar_detect_width = BIT(chandef.width);
+ else
+ radar_detect_width = 0;
+
+ mutex_lock(&rdev->devlist_mtx);
+ err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
+ chandef.chan,
+ CHAN_MODE_SHARED,
+ radar_detect_width);
+ mutex_unlock(&rdev->devlist_mtx);
+ if (err)
+ return err;
+
+ count = nla_get_u32(info->attrs[NL80211_ATTR_CH_SWITCH_COUNT]);
+ if (info->attrs[NL80211_ATTR_CH_SWITCH_BLOCK_TX])
+ block_tx = true;
+
+ err = rdev->ops->channel_switch(&rdev->wiphy, dev, &chandef,
+ block_tx, count);
+
+ return err;
+}
+
static int nl80211_send_bss(struct sk_buff *msg, struct netlink_callback *cb,
u32 seq, int flags,
struct cfg80211_registered_device *rdev,
@@ -9020,7 +9086,15 @@ static struct genl_ops nl80211_ops[] = {
.flags = GENL_ADMIN_PERM,
.internal_flags = NL80211_FLAG_NEED_WDEV_UP |
NL80211_FLAG_NEED_RTNL,
- }
+ },
+ {
+ .cmd = NL80211_CMD_CHANNEL_SWITCH,
+ .doit = nl80211_channel_switch,
+ .policy = nl80211_policy,
+ .flags = GENL_ADMIN_PERM,
+ .internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
+ NL80211_FLAG_NEED_RTNL,
+ },
};
static struct genl_multicast_group nl80211_mlme_mcgrp = {
--
1.7.10.4
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