ieee820154: add short_addr setting support

This patch adds support for setting short address via nl802154 framework.
Also added a comment because a 0xffff seems to be valid address that we
don't have a short address. This is a valid setting but we need
more checks in upper layers to don't allow this address as source address.
Also the current netlink interface doesn't allow to set the short_addr
to 0xffff. Same for the 0xfffe short address which describes a not
allocated short address.

Signed-off-by: Alexander Aring <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>
diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 88cd1293..2978c1a 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -593,6 +593,29 @@
 	return rdev_set_pan_id(rdev, wpan_dev, pan_id);
 }
 
+static int nl802154_set_short_addr(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;
+	u16 short_addr;
+
+	/* conflict here while tx/rx calls */
+	if (netif_running(dev))
+		return -EBUSY;
+
+	/* don't change address fields on monitor */
+	if (wpan_dev->iftype == NL802154_IFTYPE_MONITOR)
+		return -EINVAL;
+
+	if (!info->attrs[NL802154_ATTR_SHORT_ADDR])
+		return -EINVAL;
+
+	short_addr = nla_get_u16(info->attrs[NL802154_ATTR_SHORT_ADDR]);
+
+	return rdev_set_short_addr(rdev, wpan_dev, short_addr);
+}
+
 #define NL802154_FLAG_NEED_WPAN_PHY	0x01
 #define NL802154_FLAG_NEED_NETDEV	0x02
 #define NL802154_FLAG_NEED_RTNL		0x04
@@ -719,6 +742,14 @@
 		.internal_flags = NL802154_FLAG_NEED_NETDEV |
 				  NL802154_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL802154_CMD_SET_SHORT_ADDR,
+		.doit = nl802154_set_short_addr,
+		.policy = nl802154_policy,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = NL802154_FLAG_NEED_NETDEV |
+				  NL802154_FLAG_NEED_RTNL,
+	},
 };
 
 /* initialisation/exit functions */