wifi: nl80211: validate and configure puncturing bitmap

- New feature flag, NL80211_EXT_FEATURE_PUNCT, to advertise
  driver support for preamble puncturing in AP mode.
- New attribute, NL80211_ATTR_PUNCT_BITMAP, to receive a puncturing
  bitmap from the userspace during AP bring up (NL80211_CMD_START_AP)
  and channel switch (NL80211_CMD_CHANNEL_SWITCH) operations. Each bit
  corresponds to a 20 MHz channel in the operating bandwidth, lowest
  bit for the lowest channel. Bit set to 1 indicates that the channel
  is punctured. Higher 16 bits are reserved.
- New members added to structures cfg80211_ap_settings and
  cfg80211_csa_settings to propagate the bitmap to the driver after
  validation.

Signed-off-by: Aloka Dixit <quic_alokad@quicinc.com>
Signed-off-by: Muna Sinada <quic_msinada@quicinc.com>
Link: https://lore.kernel.org/r/20230131001227.25014-3-quic_alokad@quicinc.com
[move validation against 0xffff into policy]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c82c66c32faa..683adeb3c9e3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -805,6 +805,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_MLD_ADDR] = NLA_POLICY_EXACT_LEN(ETH_ALEN),
 	[NL80211_ATTR_MLO_SUPPORT] = { .type = NLA_FLAG },
 	[NL80211_ATTR_MAX_NUM_AKM_SUITES] = { .type = NLA_REJECT },
+	[NL80211_ATTR_PUNCT_BITMAP] = NLA_POLICY_RANGE(NLA_U8, 0, 0xffff),
 };
 
 /* policy for the key attributes */
@@ -3173,6 +3174,21 @@ static bool nl80211_can_set_dev_channel(struct wireless_dev *wdev)
 		wdev->iftype == NL80211_IFTYPE_P2P_GO;
 }
 
+static int nl80211_parse_punct_bitmap(struct cfg80211_registered_device *rdev,
+				      struct genl_info *info,
+				      const struct cfg80211_chan_def *chandef,
+				      u16 *punct_bitmap)
+{
+	if (!wiphy_ext_feature_isset(&rdev->wiphy, NL80211_EXT_FEATURE_PUNCT))
+		return -EINVAL;
+
+	*punct_bitmap = nla_get_u32(info->attrs[NL80211_ATTR_PUNCT_BITMAP]);
+	if (!cfg80211_valid_disable_subchannel_bitmap(punct_bitmap, chandef))
+		return -EINVAL;
+
+	return 0;
+}
+
 int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
 			  struct genl_info *info,
 			  struct cfg80211_chan_def *chandef)
@@ -5957,6 +5973,14 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 		goto out;
 	}
 
+	if (info->attrs[NL80211_ATTR_PUNCT_BITMAP]) {
+		err = nl80211_parse_punct_bitmap(rdev, info,
+						 &params->chandef,
+						 &params->punct_bitmap);
+		if (err)
+			goto out;
+	}
+
 	if (!cfg80211_reg_can_beacon_relax(&rdev->wiphy, &params->chandef,
 					   wdev->iftype)) {
 		err = -EINVAL;
@@ -10114,6 +10138,14 @@ skip_beacons:
 	if (info->attrs[NL80211_ATTR_CH_SWITCH_BLOCK_TX])
 		params.block_tx = true;
 
+	if (info->attrs[NL80211_ATTR_PUNCT_BITMAP]) {
+		err = nl80211_parse_punct_bitmap(rdev, info,
+						 &params.chandef,
+						 &params.punct_bitmap);
+		if (err)
+			goto free;
+	}
+
 	wdev_lock(wdev);
 	err = rdev_channel_switch(rdev, dev, &params);
 	wdev_unlock(wdev);