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>

3 files changed, 78 insertions, 2 deletions

diff --git a/net/ieee802154/nl-phy.c b/net/ieee802154/nl-phy.c
index 0af0d424dee0..c9dfd6f59e34 100644
--- a/net/ieee802154/nl-phy.c
+++ b/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);
diff --git a/net/ieee802154/nl_policy.c b/net/ieee802154/nl_policy.c
index 55b5616295ff..fd7be5e45cef 100644
--- a/net/ieee802154/nl_policy.c
+++ b/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, },
 };
 
diff --git a/net/ieee802154/wpan-class.c b/net/ieee802154/wpan-class.c
index 8d6f6704da84..edd0962d55f9 100644
--- a/net/ieee802154/wpan-class.c
+++ b/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: