From 2e7ed75e92fc493ff5484f61aed6489262c78f3e Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:05 +0200
Subject: ieee802154: Internal PAN management

Introduce structures to describe peer devices in a PAN as well as a few
related helpers. We basically care about:
- Our unique parent after associating with a coordinator.
- Peer devices, children, which successfully associated with us.

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/20230927181214.129346-3-miquel.raynal@bootlin.com
---
 include/net/cfg802154.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

(limited to 'include/net')

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index f79ce133e51a..a89f1c9cea3f 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -303,6 +303,22 @@ struct ieee802154_coord_desc {
 	bool gts_permit;
 };
 
+/**
+ * struct ieee802154_pan_device - PAN device information
+ * @pan_id: the PAN ID of this device
+ * @mode: the preferred mode to reach the device
+ * @short_addr: the short address of this device
+ * @extended_addr: the extended address of this device
+ * @node: the list node
+ */
+struct ieee802154_pan_device {
+	__le16 pan_id;
+	u8 mode;
+	__le16 short_addr;
+	__le64 extended_addr;
+	struct list_head node;
+};
+
 /**
  * struct cfg802154_scan_request - Scan request
  *
@@ -478,6 +494,11 @@ struct wpan_dev {
 
 	/* fallback for acknowledgment bit setting */
 	bool ackreq;
+
+	/* Associations */
+	struct mutex association_lock;
+	struct ieee802154_pan_device *parent;
+	struct list_head children;
 };
 
 #define to_phy(_dev)	container_of(_dev, struct wpan_phy, dev)
@@ -529,4 +550,30 @@ static inline const char *wpan_phy_name(struct wpan_phy *phy)
 void ieee802154_configure_durations(struct wpan_phy *phy,
 				    unsigned int page, unsigned int channel);
 
+/**
+ * cfg802154_device_is_associated - Checks whether we are associated to any device
+ * @wpan_dev: the wpan device
+ * @return: true if we are associated
+ */
+bool cfg802154_device_is_associated(struct wpan_dev *wpan_dev);
+
+/**
+ * cfg802154_device_is_parent - Checks if a device is our coordinator
+ * @wpan_dev: the wpan device
+ * @target: the expected parent
+ * @return: true if @target is our coordinator
+ */
+bool cfg802154_device_is_parent(struct wpan_dev *wpan_dev,
+				struct ieee802154_addr *target);
+
+/**
+ * cfg802154_device_is_child - Checks whether a device is associated to us
+ * @wpan_dev: the wpan device
+ * @target: the expected child
+ * @return: the PAN device
+ */
+struct ieee802154_pan_device *
+cfg802154_device_is_child(struct wpan_dev *wpan_dev,
+			  struct ieee802154_addr *target);
+
 #endif /* __NET_CFG802154_H */
-- 
cgit v1.2.3


From 05db59a0619969a47ab87050985344177c662cab Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:06 +0200
Subject: 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         |  4 ++++
 include/net/ieee802154_netdev.h | 38 ++++++++++++++++++++++++++++++++++++
 include/net/nl802154.h          |  1 +
 net/ieee802154/nl802154.c       | 43 +++++++++++++++++++++++++++++++++++++++++
 net/ieee802154/rdev-ops.h       | 15 ++++++++++++++
 net/ieee802154/trace.h          | 19 ++++++++++++++++++
 6 files changed, 120 insertions(+)

(limited to 'include/net')

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index a89f1c9cea3f..d0c033176220 100644
--- a/include/net/cfg802154.h
+++ b/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,
diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h
index 063313df447d..ca8c827d0d7f 100644
--- a/include/net/ieee802154_netdev.h
+++ b/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
diff --git a/include/net/nl802154.h b/include/net/nl802154.h
index 8cd9d141f5af..830e1c51d3df 100644
--- a/include/net/nl802154.h
+++ b/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 */
 
diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 1b6a9f27a6e4..e430dbf66d00 100644
--- a/net/ieee802154/nl802154.c
+++ b/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,
diff --git a/net/ieee802154/rdev-ops.h b/net/ieee802154/rdev-ops.h
index 5eaae15c610e..4843d52f1ee0 100644
--- a/net/ieee802154/rdev-ops.h
+++ b/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
diff --git a/net/ieee802154/trace.h b/net/ieee802154/trace.h
index c16db0b326fa..2e1d4f456316 100644
--- a/net/ieee802154/trace.h
+++ b/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),
-- 
cgit v1.2.3


From fefd19807fe9c65002366c749e809996a1ca4e68 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:07 +0200
Subject: mac802154: Handle associating

Joining a PAN officially goes by associating with a coordinator. This
coordinator may have been discovered thanks to the beacons it sent in
the past. Add support to the MAC layer for these associations, which
require:
- Sending an association request
- Receiving an association response

The association response contains the association status, eventually a
reason if the association was unsuccessful, and finally a short address
that we should use for intra-PAN communication from now on, if we
required one (which is the default, and not yet configurable).

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/20230927181214.129346-5-miquel.raynal@bootlin.com
---
 include/net/ieee802154_netdev.h |   5 ++
 net/ieee802154/core.c           |  12 ++++
 net/mac802154/cfg.c             |  69 ++++++++++++++++++++++
 net/mac802154/ieee802154_i.h    |  19 ++++++
 net/mac802154/main.c            |   2 +
 net/mac802154/rx.c              |   9 +++
 net/mac802154/scan.c            | 127 ++++++++++++++++++++++++++++++++++++++++
 7 files changed, 243 insertions(+)

(limited to 'include/net')

diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h
index ca8c827d0d7f..e26ffd079556 100644
--- a/include/net/ieee802154_netdev.h
+++ b/include/net/ieee802154_netdev.h
@@ -149,6 +149,11 @@ struct ieee802154_assoc_req_pl {
 #endif
 } __packed;
 
+struct ieee802154_assoc_resp_pl {
+	__le16 short_addr;
+	u8 status;
+} __packed;
+
 enum ieee802154_frame_version {
 	IEEE802154_2003_STD,
 	IEEE802154_2006_STD,
diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index cd69bdbfd59f..a08d75dd56ad 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -198,6 +198,16 @@ void wpan_phy_free(struct wpan_phy *phy)
 }
 EXPORT_SYMBOL(wpan_phy_free);
 
+static void cfg802154_free_peer_structures(struct wpan_dev *wpan_dev)
+{
+	mutex_lock(&wpan_dev->association_lock);
+
+	kfree(wpan_dev->parent);
+	wpan_dev->parent = NULL;
+
+	mutex_unlock(&wpan_dev->association_lock);
+}
+
 int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
 			   struct net *net)
 {
@@ -293,6 +303,8 @@ static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
 		rdev->opencount++;
 		break;
 	case NETDEV_UNREGISTER:
+		cfg802154_free_peer_structures(wpan_dev);
+
 		/* It is possible to get NETDEV_UNREGISTER
 		 * multiple times. To detect that, check
 		 * that the interface is still on the list
diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
index 5c3cb019f751..0e8bb1486430 100644
--- a/net/mac802154/cfg.c
+++ b/net/mac802154/cfg.c
@@ -315,6 +315,74 @@ static int mac802154_stop_beacons(struct wpan_phy *wpan_phy,
 	return mac802154_stop_beacons_locked(local, sdata);
 }
 
+static int mac802154_associate(struct wpan_phy *wpan_phy,
+			       struct wpan_dev *wpan_dev,
+			       struct ieee802154_addr *coord)
+{
+	struct ieee802154_local *local = wpan_phy_priv(wpan_phy);
+	u64 ceaddr = swab64((__force u64)coord->extended_addr);
+	struct ieee802154_sub_if_data *sdata;
+	struct ieee802154_pan_device *parent;
+	__le16 short_addr;
+	int ret;
+
+	ASSERT_RTNL();
+
+	sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(wpan_dev);
+
+	if (wpan_dev->parent) {
+		dev_err(&sdata->dev->dev,
+			"Device %8phC is already associated\n", &ceaddr);
+		return -EPERM;
+	}
+
+	if (coord->mode == IEEE802154_SHORT_ADDRESSING)
+		return -EINVAL;
+
+	parent = kzalloc(sizeof(*parent), GFP_KERNEL);
+	if (!parent)
+		return -ENOMEM;
+
+	parent->pan_id = coord->pan_id;
+	parent->mode = coord->mode;
+	parent->extended_addr = coord->extended_addr;
+	parent->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST);
+
+	/* Set the PAN ID hardware address filter beforehand to avoid dropping
+	 * the association response with a destination PAN ID field set to the
+	 * "new" PAN ID.
+	 */
+	if (local->hw.flags & IEEE802154_HW_AFILT) {
+		ret = drv_set_pan_id(local, coord->pan_id);
+		if (ret < 0)
+			goto free_parent;
+	}
+
+	ret = mac802154_perform_association(sdata, parent, &short_addr);
+	if (ret)
+		goto reset_panid;
+
+	if (local->hw.flags & IEEE802154_HW_AFILT) {
+		ret = drv_set_short_addr(local, short_addr);
+		if (ret < 0)
+			goto reset_panid;
+	}
+
+	wpan_dev->pan_id = coord->pan_id;
+	wpan_dev->short_addr = short_addr;
+	wpan_dev->parent = parent;
+
+	return 0;
+
+reset_panid:
+	if (local->hw.flags & IEEE802154_HW_AFILT)
+		drv_set_pan_id(local, cpu_to_le16(IEEE802154_PAN_ID_BROADCAST));
+
+free_parent:
+	kfree(parent);
+	return ret;
+}
+
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 static void
 ieee802154_get_llsec_table(struct wpan_phy *wpan_phy,
@@ -526,6 +594,7 @@ const struct cfg802154_ops mac802154_config_ops = {
 	.abort_scan = mac802154_abort_scan,
 	.send_beacons = mac802154_send_beacons,
 	.stop_beacons = mac802154_stop_beacons,
+	.associate = mac802154_associate,
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	.get_llsec_table = ieee802154_get_llsec_table,
 	.lock_llsec_table = ieee802154_lock_llsec_table,
diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h
index c347ec9ff8c9..fff67676b400 100644
--- a/net/mac802154/ieee802154_i.h
+++ b/net/mac802154/ieee802154_i.h
@@ -24,6 +24,7 @@
 enum ieee802154_ongoing {
 	IEEE802154_IS_SCANNING = BIT(0),
 	IEEE802154_IS_BEACONING = BIT(1),
+	IEEE802154_IS_ASSOCIATING = BIT(2),
 };
 
 /* mac802154 device private data */
@@ -74,6 +75,13 @@ struct ieee802154_local {
 	struct list_head rx_mac_cmd_list;
 	struct work_struct rx_mac_cmd_work;
 
+	/* Association */
+	struct ieee802154_pan_device *assoc_dev;
+	struct completion assoc_done;
+	__le16 assoc_addr;
+	u8 assoc_status;
+	struct work_struct assoc_work;
+
 	bool started;
 	bool suspended;
 	unsigned long ongoing;
@@ -296,6 +304,17 @@ static inline bool mac802154_is_beaconing(struct ieee802154_local *local)
 
 void mac802154_rx_mac_cmd_worker(struct work_struct *work);
 
+int mac802154_perform_association(struct ieee802154_sub_if_data *sdata,
+				  struct ieee802154_pan_device *coord,
+				  __le16 *short_addr);
+int mac802154_process_association_resp(struct ieee802154_sub_if_data *sdata,
+				       struct sk_buff *skb);
+
+static inline bool mac802154_is_associating(struct ieee802154_local *local)
+{
+	return test_bit(IEEE802154_IS_ASSOCIATING, &local->ongoing);
+}
+
 /* interface handling */
 int ieee802154_iface_init(void);
 void ieee802154_iface_exit(void);
diff --git a/net/mac802154/main.c b/net/mac802154/main.c
index 357ece67432b..9ab7396668d2 100644
--- a/net/mac802154/main.c
+++ b/net/mac802154/main.c
@@ -103,6 +103,8 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops)
 	INIT_DELAYED_WORK(&local->beacon_work, mac802154_beacon_worker);
 	INIT_WORK(&local->rx_mac_cmd_work, mac802154_rx_mac_cmd_worker);
 
+	init_completion(&local->assoc_done);
+
 	/* init supported flags with 802.15.4 default ranges */
 	phy->supported.max_minbe = 8;
 	phy->supported.min_maxbe = 3;
diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index e2434b4fe514..d0e08613a36b 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -93,6 +93,15 @@ void mac802154_rx_mac_cmd_worker(struct work_struct *work)
 
 		queue_delayed_work(local->mac_wq, &local->beacon_work, 0);
 		break;
+
+	case IEEE802154_CMD_ASSOCIATION_RESP:
+		dev_dbg(&mac_pkt->sdata->dev->dev, "processing ASSOC RESP\n");
+		if (!mac802154_is_associating(local))
+			break;
+
+		mac802154_process_association_resp(mac_pkt->sdata, mac_pkt->skb);
+		break;
+
 	default:
 		break;
 	}
diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c
index d9658f2c4ae6..5dd50e1ce329 100644
--- a/net/mac802154/scan.c
+++ b/net/mac802154/scan.c
@@ -510,3 +510,130 @@ int mac802154_send_beacons_locked(struct ieee802154_sub_if_data *sdata,
 
 	return 0;
 }
+
+int mac802154_perform_association(struct ieee802154_sub_if_data *sdata,
+				  struct ieee802154_pan_device *coord,
+				  __le16 *short_addr)
+{
+	u64 ceaddr = swab64((__force u64)coord->extended_addr);
+	struct ieee802154_association_req_frame frame = {};
+	struct ieee802154_local *local = sdata->local;
+	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
+	struct sk_buff *skb;
+	int ret;
+
+	frame.mhr.fc.type = IEEE802154_FC_TYPE_MAC_CMD;
+	frame.mhr.fc.security_enabled = 0;
+	frame.mhr.fc.frame_pending = 0;
+	frame.mhr.fc.ack_request = 1; /* We always expect an ack here */
+	frame.mhr.fc.intra_pan = 0;
+	frame.mhr.fc.dest_addr_mode = (coord->mode == IEEE802154_ADDR_LONG) ?
+		IEEE802154_EXTENDED_ADDRESSING : IEEE802154_SHORT_ADDRESSING;
+	frame.mhr.fc.version = IEEE802154_2003_STD;
+	frame.mhr.fc.source_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
+	frame.mhr.source.mode = IEEE802154_ADDR_LONG;
+	frame.mhr.source.pan_id = cpu_to_le16(IEEE802154_PANID_BROADCAST);
+	frame.mhr.source.extended_addr = wpan_dev->extended_addr;
+	frame.mhr.dest.mode = coord->mode;
+	frame.mhr.dest.pan_id = coord->pan_id;
+	if (coord->mode == IEEE802154_ADDR_LONG)
+		frame.mhr.dest.extended_addr = coord->extended_addr;
+	else
+		frame.mhr.dest.short_addr = coord->short_addr;
+	frame.mhr.seq = atomic_inc_return(&wpan_dev->dsn) & 0xFF;
+	frame.mac_pl.cmd_id = IEEE802154_CMD_ASSOCIATION_REQ;
+	frame.assoc_req_pl.device_type = 1;
+	frame.assoc_req_pl.power_source = 1;
+	frame.assoc_req_pl.rx_on_when_idle = 1;
+	frame.assoc_req_pl.alloc_addr = 1;
+
+	skb = alloc_skb(IEEE802154_MAC_CMD_SKB_SZ + sizeof(frame.assoc_req_pl),
+			GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	skb->dev = sdata->dev;
+
+	ret = ieee802154_mac_cmd_push(skb, &frame, &frame.assoc_req_pl,
+				      sizeof(frame.assoc_req_pl));
+	if (ret) {
+		kfree_skb(skb);
+		return ret;
+	}
+
+	local->assoc_dev = coord;
+	reinit_completion(&local->assoc_done);
+	set_bit(IEEE802154_IS_ASSOCIATING, &local->ongoing);
+
+	ret = ieee802154_mlme_tx_one_locked(local, sdata, skb);
+	if (ret) {
+		if (ret > 0)
+			ret = (ret == IEEE802154_NO_ACK) ? -EREMOTEIO : -EIO;
+		dev_warn(&sdata->dev->dev,
+			 "No ASSOC REQ ACK received from %8phC\n", &ceaddr);
+		goto clear_assoc;
+	}
+
+	ret = wait_for_completion_killable_timeout(&local->assoc_done, 10 * HZ);
+	if (ret <= 0) {
+		dev_warn(&sdata->dev->dev,
+			 "No ASSOC RESP received from %8phC\n", &ceaddr);
+		ret = -ETIMEDOUT;
+		goto clear_assoc;
+	}
+
+	if (local->assoc_status != IEEE802154_ASSOCIATION_SUCCESSFUL) {
+		if (local->assoc_status == IEEE802154_PAN_AT_CAPACITY)
+			ret = -ERANGE;
+		else
+			ret = -EPERM;
+
+		dev_warn(&sdata->dev->dev,
+			 "Negative ASSOC RESP received from %8phC: %s\n", &ceaddr,
+			 local->assoc_status == IEEE802154_PAN_AT_CAPACITY ?
+			 "PAN at capacity" : "access denied");
+	}
+
+	ret = 0;
+	*short_addr = local->assoc_addr;
+
+clear_assoc:
+	clear_bit(IEEE802154_IS_ASSOCIATING, &local->ongoing);
+	local->assoc_dev = NULL;
+
+	return ret;
+}
+
+int mac802154_process_association_resp(struct ieee802154_sub_if_data *sdata,
+				       struct sk_buff *skb)
+{
+	struct ieee802154_addr *src = &mac_cb(skb)->source;
+	struct ieee802154_addr *dest = &mac_cb(skb)->dest;
+	u64 deaddr = swab64((__force u64)dest->extended_addr);
+	struct ieee802154_local *local = sdata->local;
+	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
+	struct ieee802154_assoc_resp_pl resp_pl = {};
+
+	if (skb->len != sizeof(resp_pl))
+		return -EINVAL;
+
+	if (unlikely(src->mode != IEEE802154_EXTENDED_ADDRESSING ||
+		     dest->mode != IEEE802154_EXTENDED_ADDRESSING))
+		return -EINVAL;
+
+	if (unlikely(dest->extended_addr != wpan_dev->extended_addr ||
+		     src->extended_addr != local->assoc_dev->extended_addr))
+		return -ENODEV;
+
+	memcpy(&resp_pl, skb->data, sizeof(resp_pl));
+	local->assoc_addr = resp_pl.short_addr;
+	local->assoc_status = resp_pl.status;
+
+	dev_dbg(&skb->dev->dev,
+		"ASSOC RESP 0x%x received from %8phC, getting short address %04x\n",
+		local->assoc_status, &deaddr, local->assoc_addr);
+
+	complete(&local->assoc_done);
+
+	return 0;
+}
-- 
cgit v1.2.3


From 7b18313e84eb62c3e4071f9679480159d8da5107 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:08 +0200
Subject: ieee802154: Add support for user disassociation requests

A device may decide at some point to disassociate from a PAN, let's
introduce a netlink command for this purpose.

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/20230927181214.129346-6-miquel.raynal@bootlin.com
---
 include/net/cfg802154.h         |  3 +++
 include/net/ieee802154_netdev.h | 11 +++++++++++
 include/net/nl802154.h          |  1 +
 net/ieee802154/nl802154.c       | 41 +++++++++++++++++++++++++++++++++++++++++
 net/ieee802154/rdev-ops.h       | 15 +++++++++++++++
 net/ieee802154/trace.h          | 19 +++++++++++++++++++
 6 files changed, 90 insertions(+)

(limited to 'include/net')

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index d0c033176220..9b036ab20079 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -81,6 +81,9 @@ struct cfg802154_ops {
 	int	(*associate)(struct wpan_phy *wpan_phy,
 			     struct wpan_dev *wpan_dev,
 			     struct ieee802154_addr *coord);
+	int	(*disassociate)(struct wpan_phy *wpan_phy,
+				struct wpan_dev *wpan_dev,
+				struct ieee802154_addr *target);
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	void	(*get_llsec_table)(struct wpan_phy *wpan_phy,
 				   struct wpan_dev *wpan_dev,
diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h
index e26ffd079556..16194356cfe7 100644
--- a/include/net/ieee802154_netdev.h
+++ b/include/net/ieee802154_netdev.h
@@ -177,6 +177,11 @@ enum ieee802154_association_status {
 	IEEE802154_FAST_ASSOCIATION_SUCCESSFUL = 0x80,
 };
 
+enum ieee802154_disassociation_reason {
+	IEEE802154_COORD_WISHES_DEVICE_TO_LEAVE = 0x1,
+	IEEE802154_DEVICE_WISHES_TO_LEAVE = 0x2,
+};
+
 struct ieee802154_hdr {
 	struct ieee802154_hdr_fc fc;
 	u8 seq;
@@ -206,6 +211,12 @@ struct ieee802154_association_req_frame {
 	struct ieee802154_assoc_req_pl assoc_req_pl;
 };
 
+struct ieee802154_disassociation_notif_frame {
+	struct ieee802154_hdr mhr;
+	struct ieee802154_mac_cmd_pl mac_pl;
+	u8 disassoc_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
diff --git a/include/net/nl802154.h b/include/net/nl802154.h
index 830e1c51d3df..8a47c14c72f0 100644
--- a/include/net/nl802154.h
+++ b/include/net/nl802154.h
@@ -79,6 +79,7 @@ enum nl802154_commands {
 	NL802154_CMD_SEND_BEACONS,
 	NL802154_CMD_STOP_BEACONS,
 	NL802154_CMD_ASSOCIATE,
+	NL802154_CMD_DISASSOCIATE,
 
 	/* add new commands above here */
 
diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index e430dbf66d00..dd86ecd7b193 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1663,6 +1663,39 @@ static int nl802154_associate(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+static int nl802154_disassociate(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;
+	struct wpan_phy *wpan_phy = &rdev->wpan_phy;
+	struct ieee802154_addr target;
+
+	if (wpan_phy->flags & WPAN_PHY_FLAG_DATAGRAMS_ONLY) {
+		NL_SET_ERR_MSG(info->extack, "PHY only supports datagrams");
+		return -EOPNOTSUPP;
+	}
+
+	target.pan_id = wpan_dev->pan_id;
+
+	if (info->attrs[NL802154_ATTR_EXTENDED_ADDR]) {
+		target.mode = IEEE802154_ADDR_LONG;
+		target.extended_addr = nla_get_le64(info->attrs[NL802154_ATTR_EXTENDED_ADDR]);
+	} else if (info->attrs[NL802154_ATTR_SHORT_ADDR]) {
+		target.mode = IEEE802154_ADDR_SHORT;
+		target.short_addr = nla_get_le16(info->attrs[NL802154_ATTR_SHORT_ADDR]);
+	} else {
+		NL_SET_ERR_MSG(info->extack, "Device address is missing");
+		return -EINVAL;
+	}
+
+	mutex_lock(&wpan_dev->association_lock);
+	rdev_disassociate(rdev, wpan_dev, &target);
+	mutex_unlock(&wpan_dev->association_lock);
+
+	return 0;
+}
+
 #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 },
@@ -2792,6 +2825,14 @@ static const struct genl_ops nl802154_ops[] = {
 				  NL802154_FLAG_CHECK_NETDEV_UP |
 				  NL802154_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL802154_CMD_DISASSOCIATE,
+		.doit = nl802154_disassociate,
+		.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,
diff --git a/net/ieee802154/rdev-ops.h b/net/ieee802154/rdev-ops.h
index 4843d52f1ee0..64071ef6f57b 100644
--- a/net/ieee802154/rdev-ops.h
+++ b/net/ieee802154/rdev-ops.h
@@ -280,6 +280,21 @@ static inline int rdev_associate(struct cfg802154_registered_device *rdev,
 	return ret;
 }
 
+static inline int rdev_disassociate(struct cfg802154_registered_device *rdev,
+				    struct wpan_dev *wpan_dev,
+				    struct ieee802154_addr *target)
+{
+	int ret;
+
+	if (!rdev->ops->disassociate)
+		return -EOPNOTSUPP;
+
+	trace_802154_rdev_disassociate(&rdev->wpan_phy, wpan_dev, target);
+	ret = rdev->ops->disassociate(&rdev->wpan_phy, wpan_dev, target);
+	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
diff --git a/net/ieee802154/trace.h b/net/ieee802154/trace.h
index 2e1d4f456316..62aa6465253a 100644
--- a/net/ieee802154/trace.h
+++ b/net/ieee802154/trace.h
@@ -375,6 +375,25 @@ TRACE_EVENT(802154_rdev_associate,
 		  WPAN_PHY_PR_ARG, WPAN_DEV_PR_ARG, __entry->addr)
 );
 
+TRACE_EVENT(802154_rdev_disassociate,
+	TP_PROTO(struct wpan_phy *wpan_phy,
+		 struct wpan_dev *wpan_dev,
+		 struct ieee802154_addr *target),
+	TP_ARGS(wpan_phy, wpan_dev, target),
+	TP_STRUCT__entry(
+		WPAN_PHY_ENTRY
+		WPAN_DEV_ENTRY
+		__field(__le64, addr)
+	),
+	TP_fast_assign(
+		WPAN_PHY_ASSIGN;
+		WPAN_DEV_ASSIGN;
+		__entry->addr = target->extended_addr;
+	),
+	TP_printk(WPAN_PHY_PR_FMT ", " WPAN_DEV_PR_FMT ", disassociating 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),
-- 
cgit v1.2.3


From 601f160b61b2152ef84a663f856350d5dd9e752a Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:10 +0200
Subject: mac802154: Handle association requests from peers

Coordinators may have to handle association requests from peers which
want to join the PAN. The logic involves:
- Acknowledging the request (done by hardware)
- If requested, a random short address that is free on this PAN should
  be chosen for the device.
- Sending an association response with the short address allocated for
  the peer and expecting it to be ack'ed.

If anything fails during this procedure, the peer is considered not
associated.

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/20230927181214.129346-8-miquel.raynal@bootlin.com
---
 include/net/cfg802154.h         |   7 ++
 include/net/ieee802154_netdev.h |   6 ++
 net/ieee802154/core.c           |   7 ++
 net/ieee802154/pan.c            |  30 +++++++++
 net/mac802154/ieee802154_i.h    |   2 +
 net/mac802154/rx.c              |   8 +++
 net/mac802154/scan.c            | 142 ++++++++++++++++++++++++++++++++++++++++
 7 files changed, 202 insertions(+)

(limited to 'include/net')

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index 9b036ab20079..c844ae63bc04 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -583,4 +583,11 @@ struct ieee802154_pan_device *
 cfg802154_device_is_child(struct wpan_dev *wpan_dev,
 			  struct ieee802154_addr *target);
 
+/**
+ * cfg802154_get_free_short_addr - Get a free address among the known devices
+ * @wpan_dev: the wpan device
+ * @return: a random short address expectedly unused on our PAN
+ */
+__le16 cfg802154_get_free_short_addr(struct wpan_dev *wpan_dev);
+
 #endif /* __NET_CFG802154_H */
diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h
index 16194356cfe7..4de858f9929e 100644
--- a/include/net/ieee802154_netdev.h
+++ b/include/net/ieee802154_netdev.h
@@ -211,6 +211,12 @@ struct ieee802154_association_req_frame {
 	struct ieee802154_assoc_req_pl assoc_req_pl;
 };
 
+struct ieee802154_association_resp_frame {
+	struct ieee802154_hdr mhr;
+	struct ieee802154_mac_cmd_pl mac_pl;
+	struct ieee802154_assoc_resp_pl assoc_resp_pl;
+};
+
 struct ieee802154_disassociation_notif_frame {
 	struct ieee802154_hdr mhr;
 	struct ieee802154_mac_cmd_pl mac_pl;
diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index a08d75dd56ad..1670a71327a7 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -200,11 +200,18 @@ EXPORT_SYMBOL(wpan_phy_free);
 
 static void cfg802154_free_peer_structures(struct wpan_dev *wpan_dev)
 {
+	struct ieee802154_pan_device *child, *tmp;
+
 	mutex_lock(&wpan_dev->association_lock);
 
 	kfree(wpan_dev->parent);
 	wpan_dev->parent = NULL;
 
+	list_for_each_entry_safe(child, tmp, &wpan_dev->children, node) {
+		list_del(&child->node);
+		kfree(child);
+	}
+
 	mutex_unlock(&wpan_dev->association_lock);
 }
 
diff --git a/net/ieee802154/pan.c b/net/ieee802154/pan.c
index 43b8d2df2186..545461069197 100644
--- a/net/ieee802154/pan.c
+++ b/net/ieee802154/pan.c
@@ -63,3 +63,33 @@ cfg802154_device_is_child(struct wpan_dev *wpan_dev,
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(cfg802154_device_is_child);
+
+__le16 cfg802154_get_free_short_addr(struct wpan_dev *wpan_dev)
+{
+	struct ieee802154_pan_device *child;
+	__le16 addr;
+
+	lockdep_assert_held(&wpan_dev->association_lock);
+
+	do {
+		get_random_bytes(&addr, 2);
+		if (addr == cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST) ||
+		    addr == cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC))
+			continue;
+
+		if (wpan_dev->short_addr == addr)
+			continue;
+
+		if (wpan_dev->parent && wpan_dev->parent->short_addr == addr)
+			continue;
+
+		list_for_each_entry(child, &wpan_dev->children, node)
+			if (child->short_addr == addr)
+				continue;
+
+		break;
+	} while (1);
+
+	return addr;
+}
+EXPORT_SYMBOL_GPL(cfg802154_get_free_short_addr);
diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h
index 92252f86c69c..432bfa87249e 100644
--- a/net/mac802154/ieee802154_i.h
+++ b/net/mac802154/ieee802154_i.h
@@ -318,6 +318,8 @@ static inline bool mac802154_is_associating(struct ieee802154_local *local)
 int mac802154_send_disassociation_notif(struct ieee802154_sub_if_data *sdata,
 					struct ieee802154_pan_device *target,
 					u8 reason);
+int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata,
+				      struct sk_buff *skb);
 
 /* interface handling */
 int ieee802154_iface_init(void);
diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index d0e08613a36b..96040b63a4fc 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -102,6 +102,14 @@ void mac802154_rx_mac_cmd_worker(struct work_struct *work)
 		mac802154_process_association_resp(mac_pkt->sdata, mac_pkt->skb);
 		break;
 
+	case IEEE802154_CMD_ASSOCIATION_REQ:
+		dev_dbg(&mac_pkt->sdata->dev->dev, "processing ASSOC REQ\n");
+		if (mac_pkt->sdata->wpan_dev.iftype != NL802154_IFTYPE_COORD)
+			break;
+
+		mac802154_process_association_req(mac_pkt->sdata, mac_pkt->skb);
+		break;
+
 	default:
 		break;
 	}
diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c
index e2f2e1235ec6..d5f66c204bc5 100644
--- a/net/mac802154/scan.c
+++ b/net/mac802154/scan.c
@@ -697,3 +697,145 @@ int mac802154_send_disassociation_notif(struct ieee802154_sub_if_data *sdata,
 	dev_dbg(&sdata->dev->dev, "DISASSOC ACK received from %8phC\n", &teaddr);
 	return 0;
 }
+
+static int
+mac802154_send_association_resp_locked(struct ieee802154_sub_if_data *sdata,
+				       struct ieee802154_pan_device *target,
+				       struct ieee802154_assoc_resp_pl *assoc_resp_pl)
+{
+	u64 teaddr = swab64((__force u64)target->extended_addr);
+	struct ieee802154_association_resp_frame frame = {};
+	struct ieee802154_local *local = sdata->local;
+	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
+	struct sk_buff *skb;
+	int ret;
+
+	frame.mhr.fc.type = IEEE802154_FC_TYPE_MAC_CMD;
+	frame.mhr.fc.security_enabled = 0;
+	frame.mhr.fc.frame_pending = 0;
+	frame.mhr.fc.ack_request = 1; /* We always expect an ack here */
+	frame.mhr.fc.intra_pan = 1;
+	frame.mhr.fc.dest_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
+	frame.mhr.fc.version = IEEE802154_2003_STD;
+	frame.mhr.fc.source_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
+	frame.mhr.source.mode = IEEE802154_ADDR_LONG;
+	frame.mhr.source.extended_addr = wpan_dev->extended_addr;
+	frame.mhr.dest.mode = IEEE802154_ADDR_LONG;
+	frame.mhr.dest.pan_id = wpan_dev->pan_id;
+	frame.mhr.dest.extended_addr = target->extended_addr;
+	frame.mhr.seq = atomic_inc_return(&wpan_dev->dsn) & 0xFF;
+	frame.mac_pl.cmd_id = IEEE802154_CMD_ASSOCIATION_RESP;
+
+	skb = alloc_skb(IEEE802154_MAC_CMD_SKB_SZ + sizeof(*assoc_resp_pl),
+			GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	skb->dev = sdata->dev;
+
+	ret = ieee802154_mac_cmd_push(skb, &frame, assoc_resp_pl,
+				      sizeof(*assoc_resp_pl));
+	if (ret) {
+		kfree_skb(skb);
+		return ret;
+	}
+
+	ret = ieee802154_mlme_tx_locked(local, sdata, skb);
+	if (ret) {
+		dev_warn(&sdata->dev->dev,
+			 "No ASSOC RESP ACK received from %8phC\n", &teaddr);
+		if (ret > 0)
+			ret = (ret == IEEE802154_NO_ACK) ? -EREMOTEIO : -EIO;
+		return ret;
+	}
+
+	return 0;
+}
+
+int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata,
+				      struct sk_buff *skb)
+{
+	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
+	struct ieee802154_addr *src = &mac_cb(skb)->source;
+	struct ieee802154_addr *dest = &mac_cb(skb)->dest;
+	struct ieee802154_assoc_resp_pl assoc_resp_pl = {};
+	struct ieee802154_assoc_req_pl assoc_req_pl;
+	struct ieee802154_pan_device *child, *exchild;
+	struct ieee802154_addr tmp = {};
+	u64 ceaddr;
+	int ret;
+
+	if (skb->len != sizeof(assoc_req_pl))
+		return -EINVAL;
+
+	if (unlikely(src->mode != IEEE802154_EXTENDED_ADDRESSING))
+		return -EINVAL;
+
+	if (unlikely(dest->pan_id != wpan_dev->pan_id))
+		return -ENODEV;
+
+	if (dest->mode == IEEE802154_EXTENDED_ADDRESSING &&
+	    unlikely(dest->extended_addr != wpan_dev->extended_addr))
+		return -ENODEV;
+	else if (dest->mode == IEEE802154_SHORT_ADDRESSING &&
+		 unlikely(dest->short_addr != wpan_dev->short_addr))
+		return -ENODEV;
+
+	mutex_lock(&wpan_dev->association_lock);
+
+	memcpy(&assoc_req_pl, skb->data, sizeof(assoc_req_pl));
+	if (assoc_req_pl.assoc_type) {
+		dev_err(&skb->dev->dev, "Fast associations not supported yet\n");
+		ret = -EOPNOTSUPP;
+		goto unlock;
+	}
+
+	child = kzalloc(sizeof(*child), GFP_KERNEL);
+	if (!child) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	child->extended_addr = src->extended_addr;
+	child->mode = IEEE802154_EXTENDED_ADDRESSING;
+	ceaddr = swab64((__force u64)child->extended_addr);
+
+	assoc_resp_pl.status = IEEE802154_ASSOCIATION_SUCCESSFUL;
+	if (assoc_req_pl.alloc_addr) {
+		assoc_resp_pl.short_addr = cfg802154_get_free_short_addr(wpan_dev);
+		child->mode = IEEE802154_SHORT_ADDRESSING;
+	} else {
+		assoc_resp_pl.short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+	}
+	child->short_addr = assoc_resp_pl.short_addr;
+	dev_dbg(&sdata->dev->dev,
+		"Accepting ASSOC REQ from child %8phC, providing short address 0x%04x\n",
+		&ceaddr, le16_to_cpu(child->short_addr));
+
+	ret = mac802154_send_association_resp_locked(sdata, child, &assoc_resp_pl);
+	if (ret) {
+		kfree(child);
+		goto unlock;
+	}
+
+	dev_dbg(&sdata->dev->dev,
+		"Successful association with new child %8phC\n", &ceaddr);
+
+	/* Ensure this child is not already associated (might happen due to
+	 * retransmissions), in this case drop the ex structure.
+	 */
+	tmp.mode = child->mode;
+	tmp.extended_addr = child->extended_addr;
+	exchild = cfg802154_device_is_child(wpan_dev, &tmp);
+	if (exchild) {
+		dev_dbg(&sdata->dev->dev,
+			"Child %8phC was already known\n", &ceaddr);
+		list_del(&exchild->node);
+	}
+
+	list_add(&child->node, &wpan_dev->children);
+
+unlock:
+	mutex_unlock(&wpan_dev->association_lock);
+	return ret;
+}
-- 
cgit v1.2.3


From ce93b9378c306e6bcc4e0bd817acf4195b4a0288 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:11 +0200
Subject: ieee802154: Add support for limiting the number of associated devices

Coordinators may refuse associations. We need a user input for
that. Let's add a new netlink command which can provide a maximum number
of devices we accept to associate with as a first step. Later, we could
also forward the request to userspace and check whether the association
should be accepted or not.

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/20230927181214.129346-9-miquel.raynal@bootlin.com
---
 include/net/cfg802154.h   |  8 ++++++++
 include/net/nl802154.h    |  2 ++
 net/ieee802154/core.c     |  1 +
 net/ieee802154/nl802154.c | 28 ++++++++++++++++++++++++++++
 net/ieee802154/pan.c      |  8 ++++++++
 5 files changed, 47 insertions(+)

(limited to 'include/net')

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index c844ae63bc04..0d3e9af00198 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -506,6 +506,7 @@ struct wpan_dev {
 	struct mutex association_lock;
 	struct ieee802154_pan_device *parent;
 	struct list_head children;
+	unsigned int max_associations;
 };
 
 #define to_phy(_dev)	container_of(_dev, struct wpan_phy, dev)
@@ -583,6 +584,13 @@ struct ieee802154_pan_device *
 cfg802154_device_is_child(struct wpan_dev *wpan_dev,
 			  struct ieee802154_addr *target);
 
+/**
+ * cfg802154_set_max_associations - Limit the number of future associations
+ * @wpan_dev: the wpan device
+ * @max: the maximum number of devices we accept to associate
+ */
+void cfg802154_set_max_associations(struct wpan_dev *wpan_dev, unsigned int max);
+
 /**
  * cfg802154_get_free_short_addr - Get a free address among the known devices
  * @wpan_dev: the wpan device
diff --git a/include/net/nl802154.h b/include/net/nl802154.h
index 8a47c14c72f0..8b26faae49e8 100644
--- a/include/net/nl802154.h
+++ b/include/net/nl802154.h
@@ -80,6 +80,7 @@ enum nl802154_commands {
 	NL802154_CMD_STOP_BEACONS,
 	NL802154_CMD_ASSOCIATE,
 	NL802154_CMD_DISASSOCIATE,
+	NL802154_CMD_SET_MAX_ASSOCIATIONS,
 
 	/* add new commands above here */
 
@@ -149,6 +150,7 @@ enum nl802154_attrs {
 	NL802154_ATTR_SCAN_DURATION,
 	NL802154_ATTR_SCAN_DONE_REASON,
 	NL802154_ATTR_BEACON_INTERVAL,
+	NL802154_ATTR_MAX_ASSOCIATIONS,
 
 	/* add attributes here, update the policy in nl802154.c */
 
diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index 1670a71327a7..2d6fe45efa05 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -295,6 +295,7 @@ static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
 		rdev->devlist_generation++;
 		mutex_init(&wpan_dev->association_lock);
 		INIT_LIST_HEAD(&wpan_dev->children);
+		wpan_dev->max_associations = SZ_16K;
 
 		wpan_dev->netdev = dev;
 		break;
diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index dd86ecd7b193..06e0bd6ffcca 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -234,6 +234,7 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = {
 				 NL802154_SCAN_DONE_REASON_ABORTED),
 	[NL802154_ATTR_BEACON_INTERVAL] =
 		NLA_POLICY_MAX(NLA_U8, IEEE802154_ACTIVE_SCAN_DURATION),
+	[NL802154_ATTR_MAX_ASSOCIATIONS] = { .type = NLA_U32 },
 
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	[NL802154_ATTR_SEC_ENABLED] = { .type = NLA_U8, },
@@ -1696,6 +1697,26 @@ static int nl802154_disassociate(struct sk_buff *skb, struct genl_info *info)
 	return 0;
 }
 
+static int nl802154_set_max_associations(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net_device *dev = info->user_ptr[1];
+	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
+	unsigned int max_assoc;
+
+	if (!info->attrs[NL802154_ATTR_MAX_ASSOCIATIONS]) {
+		NL_SET_ERR_MSG(info->extack, "No maximum number of association given");
+		return -EINVAL;
+	}
+
+	max_assoc = nla_get_u32(info->attrs[NL802154_ATTR_MAX_ASSOCIATIONS]);
+
+	mutex_lock(&wpan_dev->association_lock);
+	cfg802154_set_max_associations(wpan_dev, max_assoc);
+	mutex_unlock(&wpan_dev->association_lock);
+
+	return 0;
+}
+
 #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 },
@@ -2833,6 +2854,13 @@ static const struct genl_ops nl802154_ops[] = {
 				  NL802154_FLAG_CHECK_NETDEV_UP |
 				  NL802154_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL802154_CMD_SET_MAX_ASSOCIATIONS,
+		.doit = nl802154_set_max_associations,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = NL802154_FLAG_NEED_NETDEV |
+				  NL802154_FLAG_NEED_RTNL,
+	},
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	{
 		.cmd = NL802154_CMD_SET_SEC_PARAMS,
diff --git a/net/ieee802154/pan.c b/net/ieee802154/pan.c
index 545461069197..fb5b0af2ef68 100644
--- a/net/ieee802154/pan.c
+++ b/net/ieee802154/pan.c
@@ -93,3 +93,11 @@ __le16 cfg802154_get_free_short_addr(struct wpan_dev *wpan_dev)
 	return addr;
 }
 EXPORT_SYMBOL_GPL(cfg802154_get_free_short_addr);
+
+void cfg802154_set_max_associations(struct wpan_dev *wpan_dev, unsigned int max)
+{
+	lockdep_assert_held(&wpan_dev->association_lock);
+
+	wpan_dev->max_associations = max;
+}
+EXPORT_SYMBOL_GPL(cfg802154_set_max_associations);
-- 
cgit v1.2.3


From 80f8bf9a2a7f603662e08f7663643a58087a2cd4 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:12 +0200
Subject: mac802154: Follow the number of associated devices

Track the count of associated devices. Limit the number of associations
using the value provided by the user if any. If we reach the maximum
number of associations, we tell the device we are at capacity. If the
user do not want to accept any more associations, it may specify the
value 0 to the maximum number of associations, which will lead to an
access denied error status returned to the peers trying to associate.

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/20230927181214.129346-10-miquel.raynal@bootlin.com
---
 include/net/cfg802154.h |  1 +
 net/ieee802154/core.c   |  2 ++
 net/mac802154/cfg.c     |  1 +
 net/mac802154/scan.c    | 33 +++++++++++++++++++++++----------
 4 files changed, 27 insertions(+), 10 deletions(-)

(limited to 'include/net')

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index 0d3e9af00198..a64bbcd71f10 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -507,6 +507,7 @@ struct wpan_dev {
 	struct ieee802154_pan_device *parent;
 	struct list_head children;
 	unsigned int max_associations;
+	unsigned int nchildren;
 };
 
 #define to_phy(_dev)	container_of(_dev, struct wpan_phy, dev)
diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index 2d6fe45efa05..60e8fff1347e 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -212,6 +212,8 @@ static void cfg802154_free_peer_structures(struct wpan_dev *wpan_dev)
 		kfree(child);
 	}
 
+	wpan_dev->nchildren = 0;
+
 	mutex_unlock(&wpan_dev->association_lock);
 }
 
diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
index 083de2d3fe37..17e2032fac24 100644
--- a/net/mac802154/cfg.c
+++ b/net/mac802154/cfg.c
@@ -454,6 +454,7 @@ static int mac802154_disassociate_child(struct wpan_phy *wpan_phy,
 		return ret;
 
 	list_del(&child->node);
+	wpan_dev->nchildren--;
 	kfree(child);
 
 	return 0;
diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c
index d5f66c204bc5..81d2c2bb1f09 100644
--- a/net/mac802154/scan.c
+++ b/net/mac802154/scan.c
@@ -800,20 +800,32 @@ int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata,
 	child->mode = IEEE802154_EXTENDED_ADDRESSING;
 	ceaddr = swab64((__force u64)child->extended_addr);
 
-	assoc_resp_pl.status = IEEE802154_ASSOCIATION_SUCCESSFUL;
-	if (assoc_req_pl.alloc_addr) {
-		assoc_resp_pl.short_addr = cfg802154_get_free_short_addr(wpan_dev);
-		child->mode = IEEE802154_SHORT_ADDRESSING;
+	if (wpan_dev->nchildren >= wpan_dev->max_associations) {
+		if (!wpan_dev->max_associations)
+			assoc_resp_pl.status = IEEE802154_PAN_ACCESS_DENIED;
+		else
+			assoc_resp_pl.status = IEEE802154_PAN_AT_CAPACITY;
+		assoc_resp_pl.short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST);
+		dev_dbg(&sdata->dev->dev,
+			"Refusing ASSOC REQ from child %8phC, %s\n", &ceaddr,
+			assoc_resp_pl.status == IEEE802154_PAN_ACCESS_DENIED ?
+			"access denied" : "too many children");
 	} else {
-		assoc_resp_pl.short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+		assoc_resp_pl.status = IEEE802154_ASSOCIATION_SUCCESSFUL;
+		if (assoc_req_pl.alloc_addr) {
+			assoc_resp_pl.short_addr = cfg802154_get_free_short_addr(wpan_dev);
+			child->mode = IEEE802154_SHORT_ADDRESSING;
+		} else {
+			assoc_resp_pl.short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+		}
+		child->short_addr = assoc_resp_pl.short_addr;
+		dev_dbg(&sdata->dev->dev,
+			"Accepting ASSOC REQ from child %8phC, providing short address 0x%04x\n",
+			&ceaddr, le16_to_cpu(child->short_addr));
 	}
-	child->short_addr = assoc_resp_pl.short_addr;
-	dev_dbg(&sdata->dev->dev,
-		"Accepting ASSOC REQ from child %8phC, providing short address 0x%04x\n",
-		&ceaddr, le16_to_cpu(child->short_addr));
 
 	ret = mac802154_send_association_resp_locked(sdata, child, &assoc_resp_pl);
-	if (ret) {
+	if (ret || assoc_resp_pl.status != IEEE802154_ASSOCIATION_SUCCESSFUL) {
 		kfree(child);
 		goto unlock;
 	}
@@ -834,6 +846,7 @@ int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata,
 	}
 
 	list_add(&child->node, &wpan_dev->children);
+	wpan_dev->nchildren++;
 
 unlock:
 	mutex_unlock(&wpan_dev->association_lock);
-- 
cgit v1.2.3


From 83fcf26b00d77e4a0ec920524fe85350a27e9c05 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 27 Sep 2023 20:12:14 +0200
Subject: ieee802154: Give the user the association list

Upon request, we must be able to provide to the user the list of
associations currently in place. Let's add a new netlink command and
attribute for this purpose.

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/20230927181214.129346-12-miquel.raynal@bootlin.com
---
 include/net/nl802154.h    |  18 +++++++-
 net/ieee802154/nl802154.c | 103 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 117 insertions(+), 4 deletions(-)

(limited to 'include/net')

diff --git a/include/net/nl802154.h b/include/net/nl802154.h
index 8b26faae49e8..4c752f799957 100644
--- a/include/net/nl802154.h
+++ b/include/net/nl802154.h
@@ -81,6 +81,7 @@ enum nl802154_commands {
 	NL802154_CMD_ASSOCIATE,
 	NL802154_CMD_DISASSOCIATE,
 	NL802154_CMD_SET_MAX_ASSOCIATIONS,
+	NL802154_CMD_LIST_ASSOCIATIONS,
 
 	/* add new commands above here */
 
@@ -151,6 +152,7 @@ enum nl802154_attrs {
 	NL802154_ATTR_SCAN_DONE_REASON,
 	NL802154_ATTR_BEACON_INTERVAL,
 	NL802154_ATTR_MAX_ASSOCIATIONS,
+	NL802154_ATTR_PEER,
 
 	/* add attributes here, update the policy in nl802154.c */
 
@@ -389,8 +391,6 @@ enum nl802154_supported_bool_states {
 	NL802154_SUPPORTED_BOOL_MAX = __NL802154_SUPPORTED_BOOL_AFTER_LAST - 1
 };
 
-#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
-
 enum nl802154_dev_addr_modes {
 	NL802154_DEV_ADDR_NONE,
 	__NL802154_DEV_ADDR_INVALID,
@@ -410,12 +410,26 @@ enum nl802154_dev_addr_attrs {
 	NL802154_DEV_ADDR_ATTR_SHORT,
 	NL802154_DEV_ADDR_ATTR_EXTENDED,
 	NL802154_DEV_ADDR_ATTR_PAD,
+	NL802154_DEV_ADDR_ATTR_PEER_TYPE,
 
 	/* keep last */
 	__NL802154_DEV_ADDR_ATTR_AFTER_LAST,
 	NL802154_DEV_ADDR_ATTR_MAX = __NL802154_DEV_ADDR_ATTR_AFTER_LAST - 1
 };
 
+enum nl802154_peer_type {
+	NL802154_PEER_TYPE_UNSPEC,
+
+	NL802154_PEER_TYPE_PARENT,
+	NL802154_PEER_TYPE_CHILD,
+
+	/* keep last */
+	__NL802154_PEER_TYPE_AFTER_LAST,
+	NL802154_PEER_TYPE_MAX = __NL802154_PEER_TYPE_AFTER_LAST - 1
+};
+
+#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
+
 enum nl802154_key_id_modes {
 	NL802154_KEY_ID_MODE_IMPLICIT,
 	NL802154_KEY_ID_MODE_INDEX,
diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 06e0bd6ffcca..822cf025120a 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -235,6 +235,7 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = {
 	[NL802154_ATTR_BEACON_INTERVAL] =
 		NLA_POLICY_MAX(NLA_U8, IEEE802154_ACTIVE_SCAN_DURATION),
 	[NL802154_ATTR_MAX_ASSOCIATIONS] = { .type = NLA_U32 },
+	[NL802154_ATTR_PEER] = { .type = NLA_NESTED },
 
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	[NL802154_ATTR_SEC_ENABLED] = { .type = NLA_U8, },
@@ -249,7 +250,6 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = {
 #endif /* CONFIG_IEEE802154_NL802154_EXPERIMENTAL */
 };
 
-#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 static int
 nl802154_prepare_wpan_dev_dump(struct sk_buff *skb,
 			       struct netlink_callback *cb,
@@ -308,7 +308,6 @@ nl802154_finish_wpan_dev_dump(struct cfg802154_registered_device *rdev)
 {
 	rtnl_unlock();
 }
-#endif /* CONFIG_IEEE802154_NL802154_EXPERIMENTAL */
 
 /* message building helper */
 static inline void *nl802154hdr_put(struct sk_buff *skb, u32 portid, u32 seq,
@@ -1717,6 +1716,101 @@ static int nl802154_set_max_associations(struct sk_buff *skb, struct genl_info *
 	return 0;
 }
 
+static int nl802154_send_peer_info(struct sk_buff *msg,
+				   struct netlink_callback *cb,
+				   u32 seq, int flags,
+				   struct cfg802154_registered_device *rdev,
+				   struct wpan_dev *wpan_dev,
+				   struct ieee802154_pan_device *peer,
+				   enum nl802154_peer_type type)
+{
+	struct nlattr *nla;
+	void *hdr;
+
+	ASSERT_RTNL();
+
+	hdr = nl802154hdr_put(msg, NETLINK_CB(cb->skb).portid, seq, flags,
+			      NL802154_CMD_LIST_ASSOCIATIONS);
+	if (!hdr)
+		return -ENOBUFS;
+
+	genl_dump_check_consistent(cb, hdr);
+
+	nla = nla_nest_start_noflag(msg, NL802154_ATTR_PEER);
+	if (!nla)
+		goto nla_put_failure;
+
+	if (nla_put_u8(msg, NL802154_DEV_ADDR_ATTR_PEER_TYPE, type))
+		goto nla_put_failure;
+
+	if (nla_put_u8(msg, NL802154_DEV_ADDR_ATTR_MODE, peer->mode))
+		goto nla_put_failure;
+
+	if (nla_put(msg, NL802154_DEV_ADDR_ATTR_SHORT,
+		    IEEE802154_SHORT_ADDR_LEN, &peer->short_addr))
+		goto nla_put_failure;
+
+	if (nla_put(msg, NL802154_DEV_ADDR_ATTR_EXTENDED,
+		    IEEE802154_EXTENDED_ADDR_LEN, &peer->extended_addr))
+		goto nla_put_failure;
+
+	nla_nest_end(msg, nla);
+
+	genlmsg_end(msg, hdr);
+
+	return 0;
+
+ nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+static int nl802154_list_associations(struct sk_buff *skb,
+				      struct netlink_callback *cb)
+{
+	struct cfg802154_registered_device *rdev;
+	struct ieee802154_pan_device *child;
+	struct wpan_dev *wpan_dev;
+	int err;
+
+	err = nl802154_prepare_wpan_dev_dump(skb, cb, &rdev, &wpan_dev);
+	if (err)
+		return err;
+
+	mutex_lock(&wpan_dev->association_lock);
+
+	if (cb->args[2])
+		goto out;
+
+	if (wpan_dev->parent) {
+		err = nl802154_send_peer_info(skb, cb, cb->nlh->nlmsg_seq,
+					      NLM_F_MULTI, rdev, wpan_dev,
+					      wpan_dev->parent,
+					      NL802154_PEER_TYPE_PARENT);
+		if (err < 0)
+			goto out_err;
+	}
+
+	list_for_each_entry(child, &wpan_dev->children, node) {
+		err = nl802154_send_peer_info(skb, cb, cb->nlh->nlmsg_seq,
+					      NLM_F_MULTI, rdev, wpan_dev,
+					      child,
+					      NL802154_PEER_TYPE_CHILD);
+		if (err < 0)
+			goto out_err;
+	}
+
+	cb->args[2] = 1;
+out:
+	err = skb->len;
+out_err:
+	mutex_unlock(&wpan_dev->association_lock);
+
+	nl802154_finish_wpan_dev_dump(rdev);
+
+	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 },
@@ -2861,6 +2955,11 @@ static const struct genl_ops nl802154_ops[] = {
 		.internal_flags = NL802154_FLAG_NEED_NETDEV |
 				  NL802154_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL802154_CMD_LIST_ASSOCIATIONS,
+		.dumpit = nl802154_list_associations,
+		/* can be retrieved by unprivileged users */
+	},
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	{
 		.cmd = NL802154_CMD_SET_SEC_PARAMS,
-- 
cgit v1.2.3


From 2373699560a754079579b7722b50d1d38de1960e Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Tue, 28 Nov 2023 12:16:55 +0100
Subject: mac802154: Avoid new associations while disassociating

While disassociating from a PAN ourselves, let's set the maximum number
of associations temporarily to zero to be sure no new device tries to
associate with us.

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/20231128111655.507479-6-miquel.raynal@bootlin.com
---
 include/net/cfg802154.h |  4 +++-
 net/ieee802154/pan.c    |  8 +++++++-
 net/mac802154/cfg.c     | 11 ++++++++---
 3 files changed, 18 insertions(+), 5 deletions(-)

(limited to 'include/net')

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index a64bbcd71f10..cd95711b12b8 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -589,8 +589,10 @@ cfg802154_device_is_child(struct wpan_dev *wpan_dev,
  * cfg802154_set_max_associations - Limit the number of future associations
  * @wpan_dev: the wpan device
  * @max: the maximum number of devices we accept to associate
+ * @return: the old maximum value
  */
-void cfg802154_set_max_associations(struct wpan_dev *wpan_dev, unsigned int max);
+unsigned int cfg802154_set_max_associations(struct wpan_dev *wpan_dev,
+					    unsigned int max);
 
 /**
  * cfg802154_get_free_short_addr - Get a free address among the known devices
diff --git a/net/ieee802154/pan.c b/net/ieee802154/pan.c
index fb5b0af2ef68..249df7364b3e 100644
--- a/net/ieee802154/pan.c
+++ b/net/ieee802154/pan.c
@@ -94,10 +94,16 @@ __le16 cfg802154_get_free_short_addr(struct wpan_dev *wpan_dev)
 }
 EXPORT_SYMBOL_GPL(cfg802154_get_free_short_addr);
 
-void cfg802154_set_max_associations(struct wpan_dev *wpan_dev, unsigned int max)
+unsigned int cfg802154_set_max_associations(struct wpan_dev *wpan_dev,
+					    unsigned int max)
 {
+	unsigned int old_max;
+
 	lockdep_assert_held(&wpan_dev->association_lock);
 
+	old_max = wpan_dev->max_associations;
 	wpan_dev->max_associations = max;
+
+	return old_max;
 }
 EXPORT_SYMBOL_GPL(cfg802154_set_max_associations);
diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
index 17e2032fac24..ef7f23af043f 100644
--- a/net/mac802154/cfg.c
+++ b/net/mac802154/cfg.c
@@ -389,6 +389,7 @@ static int mac802154_disassociate_from_parent(struct wpan_phy *wpan_phy,
 	struct ieee802154_local *local = wpan_phy_priv(wpan_phy);
 	struct ieee802154_pan_device *child, *tmp;
 	struct ieee802154_sub_if_data *sdata;
+	unsigned int max_assoc;
 	u64 eaddr;
 	int ret;
 
@@ -397,6 +398,7 @@ static int mac802154_disassociate_from_parent(struct wpan_phy *wpan_phy,
 	/* Start by disassociating all the children and preventing new ones to
 	 * attempt associations.
 	 */
+	max_assoc = cfg802154_set_max_associations(wpan_dev, 0);
 	list_for_each_entry_safe(child, tmp, &wpan_dev->children, node) {
 		ret = mac802154_send_disassociation_notif(sdata, child,
 							  IEEE802154_COORD_WISHES_DEVICE_TO_LEAVE);
@@ -429,14 +431,17 @@ static int mac802154_disassociate_from_parent(struct wpan_phy *wpan_phy,
 	if (local->hw.flags & IEEE802154_HW_AFILT) {
 		ret = drv_set_pan_id(local, wpan_dev->pan_id);
 		if (ret < 0)
-			return ret;
+			goto reset_mac_assoc;
 
 		ret = drv_set_short_addr(local, wpan_dev->short_addr);
 		if (ret < 0)
-			return ret;
+			goto reset_mac_assoc;
 	}
 
-	return 0;
+reset_mac_assoc:
+	cfg802154_set_max_associations(wpan_dev, max_assoc);
+
+	return ret;
 }
 
 static int mac802154_disassociate_child(struct wpan_phy *wpan_phy,
-- 
cgit v1.2.3