ieee820154: add backoff exponent setting support

This patch adds support for setting backoff exponents via nl802154
framework.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

3 files changed, 61 insertions, 0 deletions

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 2978c1a78017..d1cf3021ff36 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -616,6 +616,32 @@ static int nl802154_set_short_addr(struct sk_buff *skb, struct genl_info *info)
         return rdev_set_short_addr(rdev, wpan_dev, short_addr);
 }
 
+static int
+nl802154_set_backoff_exponent(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg802154_registered_device *rdev = info->user_ptr[0];
+        struct net_device *dev = info->user_ptr[1];
+        struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
+        u8 min_be, max_be;
+
+        /* should be set on netif open inside phy settings */
+        if (netif_running(dev))
+                return -EBUSY;
+
+        if (!info->attrs[NL802154_ATTR_MIN_BE] ||
+            !info->attrs[NL802154_ATTR_MAX_BE])
+                return -EINVAL;
+
+        min_be = nla_get_u8(info->attrs[NL802154_ATTR_MIN_BE]);
+        max_be = nla_get_u8(info->attrs[NL802154_ATTR_MAX_BE]);
+
+        /* check 802.15.4 constraints */
+        if (max_be < 3 || max_be > 8 || min_be > max_be)
+                return -EINVAL;
+
+        return rdev_set_backoff_exponent(rdev, wpan_dev, min_be, max_be);
+}
+
 #define NL802154_FLAG_NEED_WPAN_PHY     0x01
 #define NL802154_FLAG_NEED_NETDEV       0x02
 #define NL802154_FLAG_NEED_RTNL         0x04
@@ -750,6 +776,14 @@ static const struct genl_ops nl802154_ops[] = {
                 .internal_flags = NL802154_FLAG_NEED_NETDEV |
                                   NL802154_FLAG_NEED_RTNL,
         },
+        {
+                .cmd = NL802154_CMD_SET_BACKOFF_EXPONENT,
+                .doit = nl802154_set_backoff_exponent,
+                .policy = nl802154_policy,
+                .flags = GENL_ADMIN_PERM,
+                .internal_flags = NL802154_FLAG_NEED_NETDEV |
+                                  NL802154_FLAG_NEED_RTNL,
+        },
 };
 
 /* initialisation/exit functions */
diff --git a/net/ieee802154/rdev-ops.h b/net/ieee802154/rdev-ops.h
index 16b0de06c3af..dbccfa9383fd 100644
--- a/net/ieee802154/rdev-ops.h
+++ b/net/ieee802154/rdev-ops.h
@@ -41,4 +41,13 @@ rdev_set_short_addr(struct cfg802154_registered_device *rdev,
         return rdev->ops->set_short_addr(&rdev->wpan_phy, wpan_dev, short_addr);
 }
 
+static inline int
+rdev_set_backoff_exponent(struct cfg802154_registered_device *rdev,
+                          struct wpan_dev *wpan_dev, const u8 min_be,
+                          const u8 max_be)
+{
+        return rdev->ops->set_backoff_exponent(&rdev->wpan_phy, wpan_dev,
+                                               min_be, max_be);
+}
+
 #endif /* __CFG802154_RDEV_OPS */
diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
index df29976d1321..67c96f981693 100644
--- a/net/mac802154/cfg.c
+++ b/net/mac802154/cfg.c
@@ -84,6 +84,23 @@ static int ieee802154_set_pan_id(struct wpan_phy *wpan_phy,
 }
 
 static int
+ieee802154_set_backoff_exponent(struct wpan_phy *wpan_phy,
+                                struct wpan_dev *wpan_dev,
+                                const u8 min_be, const u8 max_be)
+{
+        struct ieee802154_local *local = wpan_phy_priv(wpan_phy);
+
+        ASSERT_RTNL();
+
+        if (!(local->hw.flags & IEEE802154_HW_CSMA_PARAMS))
+                return -EOPNOTSUPP;
+
+        wpan_dev->min_be = min_be;
+        wpan_dev->max_be = max_be;
+        return 0;
+}
+
+static int
 ieee802154_set_short_addr(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev,
                           const u16 short_addr)
 {
@@ -114,4 +131,5 @@ const struct cfg802154_ops mac802154_config_ops = {
         .set_channel = ieee802154_set_channel,
         .set_pan_id = ieee802154_set_pan_id,
         .set_short_addr = ieee802154_set_short_addr,
+        .set_backoff_exponent = ieee802154_set_backoff_exponent,
 };