ieee802154: Add support for user association requests

Users may decide to associate with a peer, which becomes our parent
coordinator. Let's add the necessary netlink support for this.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/linux-wpan/20230927181214.129346-4-miquel.raynal@bootlin.com

include/net/cfg802154.h

@@ -20,6 +20,7 @@ struct wpan_phy;
 struct wpan_phy_cca;
 struct cfg802154_scan_request;
 struct cfg802154_beacon_request;
+struct ieee802154_addr;
 
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 struct ieee802154_llsec_device_key;
@@ -77,6 +78,9 @@ struct cfg802154_ops {
 				struct cfg802154_beacon_request *request);
 	int	(*stop_beacons)(struct wpan_phy *wpan_phy,
 				struct wpan_dev *wpan_dev);
+	int	(*associate)(struct wpan_phy *wpan_phy,
+			     struct wpan_dev *wpan_dev,
+			     struct ieee802154_addr *coord);
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	void	(*get_llsec_table)(struct wpan_phy *wpan_phy,
 				   struct wpan_dev *wpan_dev,

include/net/ieee802154_netdev.h

@@ -125,6 +125,30 @@ struct ieee802154_hdr_fc {
 #endif
 };
 
+struct ieee802154_assoc_req_pl {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	u8 reserved1:1,
+	   device_type:1,
+	   power_source:1,
+	   rx_on_when_idle:1,
+	   assoc_type:1,
+	   reserved2:1,
+	   security_cap:1,
+	   alloc_addr:1;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	u8 alloc_addr:1,
+	   security_cap:1,
+	   reserved2:1,
+	   assoc_type:1,
+	   rx_on_when_idle:1,
+	   power_source:1,
+	   device_type:1,
+	   reserved1:1;
+#else
+#error	"Please fix <asm/byteorder.h>"
+#endif
+} __packed;
+
 enum ieee802154_frame_version {
 	IEEE802154_2003_STD,
 	IEEE802154_2006_STD,
@@ -140,6 +164,14 @@ enum ieee802154_addressing_mode {
 	IEEE802154_EXTENDED_ADDRESSING,
 };
 
+enum ieee802154_association_status {
+	IEEE802154_ASSOCIATION_SUCCESSFUL = 0x00,
+	IEEE802154_PAN_AT_CAPACITY = 0x01,
+	IEEE802154_PAN_ACCESS_DENIED = 0x02,
+	IEEE802154_HOPPING_SEQUENCE_OFFSET_DUP = 0x03,
+	IEEE802154_FAST_ASSOCIATION_SUCCESSFUL = 0x80,
+};
+
 struct ieee802154_hdr {
 	struct ieee802154_hdr_fc fc;
 	u8 seq;
@@ -163,6 +195,12 @@ struct ieee802154_beacon_req_frame {
 	struct ieee802154_mac_cmd_pl mac_pl;
 };
 
+struct ieee802154_association_req_frame {
+	struct ieee802154_hdr mhr;
+	struct ieee802154_mac_cmd_pl mac_pl;
+	struct ieee802154_assoc_req_pl assoc_req_pl;
+};
+
 /* pushes hdr onto the skb. fields of hdr->fc that can be calculated from
  * the contents of hdr will be, and the actual value of those bits in
  * hdr->fc will be ignored. this includes the INTRA_PAN bit and the frame

include/net/nl802154.h

@@ -78,6 +78,7 @@ enum nl802154_commands {
 	NL802154_CMD_SCAN_DONE,
 	NL802154_CMD_SEND_BEACONS,
 	NL802154_CMD_STOP_BEACONS,
+	NL802154_CMD_ASSOCIATE,
 
 	/* add new commands above here */
 

net/ieee802154/nl802154.c

@@ -1628,6 +1628,41 @@ nl802154_stop_beacons(struct sk_buff *skb, struct genl_info *info)
 	return rdev_stop_beacons(rdev, wpan_dev);
 }
 
+static int nl802154_associate(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;
+	struct wpan_phy *wpan_phy;
+	struct ieee802154_addr coord;
+	int err;
+
+	wpan_dev = dev->ieee802154_ptr;
+	wpan_phy = &rdev->wpan_phy;
+
+	if (wpan_phy->flags & WPAN_PHY_FLAG_DATAGRAMS_ONLY) {
+		NL_SET_ERR_MSG(info->extack, "PHY only supports datagrams");
+		return -EOPNOTSUPP;
+	}
+
+	if (!info->attrs[NL802154_ATTR_PAN_ID] ||
+	    !info->attrs[NL802154_ATTR_EXTENDED_ADDR])
+		return -EINVAL;
+
+	coord.pan_id = nla_get_le16(info->attrs[NL802154_ATTR_PAN_ID]);
+	coord.mode = IEEE802154_ADDR_LONG;
+	coord.extended_addr = nla_get_le64(info->attrs[NL802154_ATTR_EXTENDED_ADDR]);
+
+	mutex_lock(&wpan_dev->association_lock);
+	err = rdev_associate(rdev, wpan_dev, &coord);
+	mutex_unlock(&wpan_dev->association_lock);
+	if (err)
+		pr_err("Association with PAN ID 0x%x failed (%d)\n",
+		       le16_to_cpu(coord.pan_id), err);
+
+	return err;
+}
+
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 static const struct nla_policy nl802154_dev_addr_policy[NL802154_DEV_ADDR_ATTR_MAX + 1] = {
 	[NL802154_DEV_ADDR_ATTR_PAN_ID] = { .type = NLA_U16 },
@@ -2749,6 +2784,14 @@ static const struct genl_ops nl802154_ops[] = {
 				  NL802154_FLAG_CHECK_NETDEV_UP |
 				  NL802154_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL802154_CMD_ASSOCIATE,
+		.doit = nl802154_associate,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = NL802154_FLAG_NEED_NETDEV |
+				  NL802154_FLAG_CHECK_NETDEV_UP |
+				  NL802154_FLAG_NEED_RTNL,
+	},
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	{
 		.cmd = NL802154_CMD_SET_SEC_PARAMS,

net/ieee802154/rdev-ops.h

@@ -265,6 +265,21 @@ static inline int rdev_stop_beacons(struct cfg802154_registered_device *rdev,
 	return ret;
 }
 
+static inline int rdev_associate(struct cfg802154_registered_device *rdev,
+				 struct wpan_dev *wpan_dev,
+				 struct ieee802154_addr *coord)
+{
+	int ret;
+
+	if (!rdev->ops->associate)
+		return -EOPNOTSUPP;
+
+	trace_802154_rdev_associate(&rdev->wpan_phy, wpan_dev, coord);
+	ret = rdev->ops->associate(&rdev->wpan_phy, wpan_dev, coord);
+	trace_802154_rdev_return_int(&rdev->wpan_phy, ret);
+	return ret;
+}
+
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 /* TODO this is already a nl802154, so move into ieee802154 */
 static inline void

net/ieee802154/trace.h

@@ -356,6 +356,25 @@ DEFINE_EVENT(802154_wdev_template, 802154_rdev_stop_beacons,
 	TP_ARGS(wpan_phy, wpan_dev)
 );
 
+TRACE_EVENT(802154_rdev_associate,
+	TP_PROTO(struct wpan_phy *wpan_phy,
+		 struct wpan_dev *wpan_dev,
+		 struct ieee802154_addr *coord),
+	TP_ARGS(wpan_phy, wpan_dev, coord),
+	TP_STRUCT__entry(
+		WPAN_PHY_ENTRY
+		WPAN_DEV_ENTRY
+		__field(__le64, addr)
+	),
+	TP_fast_assign(
+		WPAN_PHY_ASSIGN;
+		WPAN_DEV_ASSIGN;
+		__entry->addr = coord->extended_addr;
+	),
+	TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", associating with: 0x%llx",
+		  WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, __entry->addr)
+);
+
 TRACE_EVENT(802154_rdev_return_int,
 	TP_PROTO(struct wpan_phy *wpan_phy, int ret),
 	TP_ARGS(wpan_phy, ret),