wireless: Require HANDLE_DFS flag to switch channel for non-AP mode (8d9de16f) · Commits · 戴 / test

In the case the channel should be switched to one requiring DFS we need to make sure that userspace will handle radar events when they happen. For AP mode this is assumed to be the case, as a manager like hostapd is required. However IBSS and MESH modes can work without further userspace assistance, so refuse to use DFS channels unless userspace vouches that it handles DFS. NOTE: Userspace should have already flagged support earlier during mesh or IBSS setup. However, this information is not readily accessible currently. Signed-off-by:

Benjamin Berg <benjamin@sipsolutions.net> [sw: style cleanups] Signed-off-by:

Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by:

Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

+13 −1

Original line number	Diff line number	Diff line
		@@ -7501,6 +7501,7 @@ static int nl80211_channel_switch(struct sk_buff skb, struct genl_info info)
		static struct nlattr *csa_attrs[NL80211_ATTR_MAX+1];
		int err;
		bool need_new_beacon = false;
		bool need_handle_dfs_flag = true;
		int len, i;
		u32 cs_count;

		@@ -7512,6 +7513,12 @@ static int nl80211_channel_switch(struct sk_buff skb, struct genl_info info)
		case NL80211_IFTYPE_AP:
		case NL80211_IFTYPE_P2P_GO:
		need_new_beacon = true;
		/* For all modes except AP the handle_dfs flag needs to be
		* supplied to tell the kernel that userspace will handle radar
		* events when they happen. Otherwise a switch to a channel
		* requiring DFS will be rejected.
		*/
		need_handle_dfs_flag = false;

		/* useless if AP is not running */
		if (!wdev->beacon_interval)
		@@ -7634,8 +7641,13 @@ skip_beacons:
		if (err < 0)
		return err;

		if (err > 0)
		if (err > 0) {
		params.radar_required = true;
		if (need_handle_dfs_flag &&
		!nla_get_flag(info->attrs[NL80211_ATTR_HANDLE_DFS])) {
		return -EINVAL;
		}
		}

		if (info->attrs[NL80211_ATTR_CH_SWITCH_BLOCK_TX])
		params.block_tx = true;

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