cfg80211: enable dynack through nl80211

Enable ACK timeout estimation algorithm (dynack) using mac80211
set_coverage_class API. Dynack is activated passing coverage class equals to -1
to lower drivers and it is automatically disabled setting valid value for
coverage class.
Define NL80211_ATTR_WIPHY_DYN_ACK flag attribute to enable dynack from
userspace. In order to activate dynack NL80211_FEATURE_ACKTO_ESTIMATION feature
flag must be set by lower drivers to indicate dynack capability.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 459dc2769d0e..cf178d2b621d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -226,6 +226,7 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
         [NL80211_ATTR_WIPHY_FRAG_THRESHOLD] = { .type = NLA_U32 },
         [NL80211_ATTR_WIPHY_RTS_THRESHOLD] = { .type = NLA_U32 },
         [NL80211_ATTR_WIPHY_COVERAGE_CLASS] = { .type = NLA_U8 },
+        [NL80211_ATTR_WIPHY_DYN_ACK] = { .type = NLA_FLAG },
 
         [NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },
         [NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },
@@ -2239,11 +2240,21 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
         }
 
         if (info->attrs[NL80211_ATTR_WIPHY_COVERAGE_CLASS]) {
+                if (info->attrs[NL80211_ATTR_WIPHY_DYN_ACK])
+                        return -EINVAL;
+
                 coverage_class = nla_get_u8(
                         info->attrs[NL80211_ATTR_WIPHY_COVERAGE_CLASS]);
                 changed |= WIPHY_PARAM_COVERAGE_CLASS;
         }
 
+        if (info->attrs[NL80211_ATTR_WIPHY_DYN_ACK]) {
+                if (!(rdev->wiphy.features & NL80211_FEATURE_ACKTO_ESTIMATION))
+                        return -EOPNOTSUPP;
+
+                changed |= WIPHY_PARAM_DYN_ACK;
+        }
+
         if (changed) {
                 u8 old_retry_short, old_retry_long;
                 u32 old_frag_threshold, old_rts_threshold;