ieee802154: add netlink APIs for smartMAC configuration

Introduce new netlink attributes for SET_PHY_ATTRS:
 * CSMA minimal backoff exponent
 * CSMA maximal backoff exponent
 * CSMA retry limit
 * frame retransmission limit

The CSMA attributes shall correspond to minBE, maxBE and maxCSMABackoffs of
802.15.4, respectively. The frame retransmission shall correspond to
maxFrameRetries of 802.15.4, unless given as -1: then the old behaviour
of the stack shall apply. For RF2xy, the old behaviour is to not do
channel sensing at all and simply send *right now*, which is not
intended behaviour for most applications and actually prohibited for
some channel/page combinations.

For all values except frame retransmission limit, the defaults of
802.15.4 apply. Frame retransmission limits are set to -1 to indicate
backward-compatible behaviour.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/nl802154.h

@@ -74,6 +74,11 @@ enum {
 	IEEE802154_ATTR_LBT_ENABLED,
 	IEEE802154_ATTR_CCA_MODE,
 	IEEE802154_ATTR_CCA_ED_LEVEL,
+	IEEE802154_ATTR_CSMA_RETRIES,
+	IEEE802154_ATTR_CSMA_MIN_BE,
+	IEEE802154_ATTR_CSMA_MAX_BE,
+
+	IEEE802154_ATTR_FRAME_RETRIES,
 
 	__IEEE802154_ATTR_MAX,
 };

include/net/mac802154.h

@@ -131,6 +131,14 @@ struct ieee802154_dev {
  *	  Sets the CCA energy detection threshold in dBm. Called with pib_lock
  *	  held.
  *	  Returns either zero, or negative errno.
+ *
+ * set_csma_params
+ *	  Sets the CSMA parameter set for the PHY. Called with pib_lock held.
+ *	  Returns either zero, or negative errno.
+ *
+ * set_frame_retries
+ *	  Sets the retransmission attempt limit. Called with pib_lock held.
+ *	  Returns either zero, or negative errno.
  */
 struct ieee802154_ops {
 	struct module	*owner;
@@ -152,6 +160,10 @@ struct ieee802154_ops {
 	int		(*set_cca_mode)(struct ieee802154_dev *dev, u8 mode);
 	int		(*set_cca_ed_level)(struct ieee802154_dev *dev,
 					    s32 level);
+	int		(*set_csma_params)(struct ieee802154_dev *dev,
+					   u8 min_be, u8 max_be, u8 retries);
+	int		(*set_frame_retries)(struct ieee802154_dev *dev,
+					     s8 retries);
 };
 
 /* Basic interface to register ieee802154 device */

include/net/wpan-phy.h

@@ -46,6 +46,10 @@ struct wpan_phy {
 	u32 channels_supported[32];
 	s8 transmit_power;
 	u8 cca_mode;
+	u8 min_be;
+	u8 max_be;
+	u8 csma_retries;
+	s8 frame_retries;
 
 	bool lbt;
 	s32 cca_ed_level;
@@ -61,6 +65,9 @@ struct wpan_phy {
 	int (*set_lbt)(struct wpan_phy *phy, bool on);
 	int (*set_cca_mode)(struct wpan_phy *phy, u8 cca_mode);
 	int (*set_cca_ed_level)(struct wpan_phy *phy, int level);
+	int (*set_csma_params)(struct wpan_phy *phy, u8 min_be, u8 max_be,
+			       u8 retries);
+	int (*set_frame_retries)(struct wpan_phy *phy, s8 retries);
 
 	char priv[0] __attribute__((__aligned__(NETDEV_ALIGN)));
 };

net/ieee802154/nl-phy.c

@@ -59,7 +59,11 @@ static int ieee802154_nl_fill_phy(struct sk_buff *msg, u32 portid,
 	    nla_put_s8(msg, IEEE802154_ATTR_TXPOWER, phy->transmit_power) ||
 	    nla_put_u8(msg, IEEE802154_ATTR_LBT_ENABLED, phy->lbt) ||
 	    nla_put_u8(msg, IEEE802154_ATTR_CCA_MODE, phy->cca_mode) ||
-	    nla_put_s32(msg, IEEE802154_ATTR_CCA_ED_LEVEL, phy->cca_ed_level))
+	    nla_put_s32(msg, IEEE802154_ATTR_CCA_ED_LEVEL, phy->cca_ed_level) ||
+	    nla_put_u8(msg, IEEE802154_ATTR_CSMA_RETRIES, phy->csma_retries) ||
+	    nla_put_u8(msg, IEEE802154_ATTR_CSMA_MIN_BE, phy->min_be) ||
+	    nla_put_u8(msg, IEEE802154_ATTR_CSMA_MAX_BE, phy->max_be) ||
+	    nla_put_s8(msg, IEEE802154_ATTR_FRAME_RETRIES, phy->frame_retries))
 		goto nla_put_failure;
 	for (i = 0; i < 32; i++) {
 		if (phy->channels_supported[i])
@@ -418,6 +422,49 @@ static int phy_set_cca_ed_level(struct wpan_phy *phy, struct genl_info *info)
 	return 0;
 }
 
+static int phy_set_csma_params(struct wpan_phy *phy, struct genl_info *info)
+{
+	int rc;
+	u8 min_be = phy->min_be;
+	u8 max_be = phy->max_be;
+	u8 retries = phy->csma_retries;
+
+	if (info->attrs[IEEE802154_ATTR_CSMA_RETRIES])
+		retries = nla_get_u8(info->attrs[IEEE802154_ATTR_CSMA_RETRIES]);
+	if (info->attrs[IEEE802154_ATTR_CSMA_MIN_BE])
+		min_be = nla_get_u8(info->attrs[IEEE802154_ATTR_CSMA_MIN_BE]);
+	if (info->attrs[IEEE802154_ATTR_CSMA_MAX_BE])
+		max_be = nla_get_u8(info->attrs[IEEE802154_ATTR_CSMA_MAX_BE]);
+
+	if (retries > 5 || max_be > 8 || min_be > max_be ||
+	    retries < -1 || retries > 7)
+		return -EINVAL;
+
+	rc = phy->set_csma_params(phy, min_be, max_be, retries);
+	if (rc < 0)
+		return rc;
+
+	phy->min_be = min_be;
+	phy->max_be = max_be;
+	phy->csma_retries = retries;
+
+	return 0;
+}
+
+static int phy_set_frame_retries(struct wpan_phy *phy, struct genl_info *info)
+{
+	s8 retries = nla_get_s8(info->attrs[IEEE802154_ATTR_FRAME_RETRIES]);
+	int rc;
+
+	rc = phy->set_frame_retries(phy, retries);
+	if (rc < 0)
+		return rc;
+
+	phy->frame_retries = retries;
+
+	return 0;
+}
+
 int ieee802154_set_phyparams(struct sk_buff *skb, struct genl_info *info)
 {
 	struct wpan_phy *phy;
@@ -429,7 +476,11 @@ int ieee802154_set_phyparams(struct sk_buff *skb, struct genl_info *info)
 	if (!info->attrs[IEEE802154_ATTR_PHY_NAME] &&
 	    !info->attrs[IEEE802154_ATTR_LBT_ENABLED] &&
 	    !info->attrs[IEEE802154_ATTR_CCA_MODE] &&
-	    !info->attrs[IEEE802154_ATTR_CCA_ED_LEVEL])
+	    !info->attrs[IEEE802154_ATTR_CCA_ED_LEVEL] &&
+	    !info->attrs[IEEE802154_ATTR_CSMA_RETRIES] &&
+	    !info->attrs[IEEE802154_ATTR_CSMA_MIN_BE] &&
+	    !info->attrs[IEEE802154_ATTR_CSMA_MAX_BE] &&
+	    !info->attrs[IEEE802154_ATTR_FRAME_RETRIES])
 		return -EINVAL;
 
 	name = nla_data(info->attrs[IEEE802154_ATTR_PHY_NAME]);
@@ -473,6 +524,20 @@ int ieee802154_set_phyparams(struct sk_buff *skb, struct genl_info *info)
 			goto error;
 	}
 
+	if (info->attrs[IEEE802154_ATTR_CSMA_RETRIES] ||
+	    info->attrs[IEEE802154_ATTR_CSMA_MIN_BE] ||
+	    info->attrs[IEEE802154_ATTR_CSMA_MAX_BE]) {
+		rc = phy_set_csma_params(phy, info);
+		if (rc < 0)
+			goto error;
+	}
+
+	if (info->attrs[IEEE802154_ATTR_FRAME_RETRIES]) {
+		rc = phy_set_frame_retries(phy, info);
+		if (rc < 0)
+			goto error;
+	}
+
 	mutex_unlock(&phy->pib_lock);
 
 	wpan_phy_put(phy);

net/ieee802154/nl_policy.c

@@ -57,5 +57,10 @@ const struct nla_policy ieee802154_policy[IEEE802154_ATTR_MAX + 1] = {
 	[IEEE802154_ATTR_LBT_ENABLED] = { .type = NLA_U8, },
 	[IEEE802154_ATTR_CCA_MODE] = { .type = NLA_U8, },
 	[IEEE802154_ATTR_CCA_ED_LEVEL] = { .type = NLA_S32, },
+	[IEEE802154_ATTR_CSMA_RETRIES] = { .type = NLA_U8, },
+	[IEEE802154_ATTR_CSMA_MIN_BE] = { .type = NLA_U8, },
+	[IEEE802154_ATTR_CSMA_MAX_BE] = { .type = NLA_U8, },
+
+	[IEEE802154_ATTR_FRAME_RETRIES] = { .type = NLA_S8, },
 };
 

net/ieee802154/wpan-class.c

@@ -169,6 +169,12 @@ struct wpan_phy *wpan_phy_alloc(size_t priv_size)
 	phy->current_channel = -1; /* not initialised */
 	phy->current_page = 0; /* for compatibility */
 
+	/* defaults per 802.15.4-2011 */
+	phy->min_be = 3;
+	phy->max_be = 5;
+	phy->csma_retries = 4;
+	phy->frame_retries = -1; /* for compatibility, actual default is 3 */
+
 	return phy;
 
 out:

net/mac802154/ieee802154_dev.c

@@ -205,6 +205,27 @@ static int mac802154_set_cca_ed_level(struct wpan_phy *phy, s32 level)
 	return priv->ops->set_cca_ed_level(&priv->hw, level);
 }
 
+static int mac802154_set_csma_params(struct wpan_phy *phy, u8 min_be,
+				     u8 max_be, u8 retries)
+{
+	struct mac802154_priv *priv = wpan_phy_priv(phy);
+
+	if (!priv->ops->set_csma_params)
+		return -ENOTSUPP;
+
+	return priv->ops->set_csma_params(&priv->hw, min_be, max_be, retries);
+}
+
+static int mac802154_set_frame_retries(struct wpan_phy *phy, s8 retries)
+{
+	struct mac802154_priv *priv = wpan_phy_priv(phy);
+
+	if (!priv->ops->set_frame_retries)
+		return -ENOTSUPP;
+
+	return priv->ops->set_frame_retries(&priv->hw, retries);
+}
+
 struct ieee802154_dev *
 ieee802154_alloc_device(size_t priv_data_len, struct ieee802154_ops *ops)
 {
@@ -286,6 +307,8 @@ int ieee802154_register_device(struct ieee802154_dev *dev)
 	priv->phy->set_lbt = mac802154_set_lbt;
 	priv->phy->set_cca_mode = mac802154_set_cca_mode;
 	priv->phy->set_cca_ed_level = mac802154_set_cca_ed_level;
+	priv->phy->set_csma_params = mac802154_set_csma_params;
+	priv->phy->set_frame_retries = mac802154_set_frame_retries;
 
 	rc = wpan_phy_register(priv->phy);
 	if (rc < 0)