[PATCH wpan-next 02/11] ieee802154: Internal PAN management

Miquel Raynal
2023-06-01T15:49:31Z

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>
---
include/net/cfg802154.h | 46 ++++++++++++++++++++++++++++
net/ieee802154/Makefile | 2 +-
net/ieee802154/core.c | 2 ++
net/ieee802154/pan.c | 66 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 115 insertions(+), 1 deletion(-)
create mode 100644 net/ieee802154/pan.c

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index e00057984489..c67adf584672 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -302,6 +302,22 @@ 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
*
@@ -477,6 +493,11 @@ 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)
@@ -528,4 +549,29 @@ 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
+ */
+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 */
diff --git a/net/ieee802154/Makefile b/net/ieee802154/Makefile
index f05b7bdae2aa..7bce67673e83 100644
--- a/net/ieee802154/Makefile
+++ b/net/ieee802154/Makefile
@@ -4,7 +4,7 @@ obj-$(CONFIG_IEEE802154_SOCKET) += ieee802154_socket.o
obj-y += 6lowpan/

ieee802154-y := netlink.o nl-mac.o nl-phy.o nl_policy.o core.o \
- header_ops.o sysfs.o nl802154.o trace.o
+ header_ops.o sysfs.o nl802154.o trace.o pan.o
ieee802154_socket-y := socket.o

CFLAGS_trace.o := -I$(src)
diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index 57546e07e06a..cd69bdbfd59f 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -276,6 +276,8 @@ static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
wpan_dev->identifier = ++rdev->wpan_dev_id;
list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
rdev->devlist_generation++;
+ mutex_init(&wpan_dev->association_lock);
+ INIT_LIST_HEAD(&wpan_dev->children);

wpan_dev->netdev = dev;
break;
diff --git a/net/ieee802154/pan.c b/net/ieee802154/pan.c
new file mode 100644
index 000000000000..e2a12a42ba2b
--- /dev/null
+++ b/net/ieee802154/pan.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IEEE 802.15.4 PAN management
+ *
+ * Copyright (C) 2021 Qorvo US, Inc
+ * Authors:
+ * - David Girault <david.girault@qorvo.com>
+ * - Miquel Raynal <miquel.raynal@bootlin.com>
+ */
+
+#include <linux/kernel.h>
+#include <net/cfg802154.h>
+#include <net/af_ieee802154.h>
+
+static bool cfg802154_same_addr(struct ieee802154_pan_device *a,
+ struct ieee802154_addr *b)
+{
+ if (!a || !b)
+ return false;
+
+ switch (b->mode) {
+ case IEEE802154_ADDR_SHORT:
+ return a->short_addr == b->short_addr;
+ case IEEE802154_ADDR_LONG:
+ return a->extended_addr == b->extended_addr;
+ default:
+ return false;
+ }
+}
+
+bool cfg802154_device_is_associated(struct wpan_dev *wpan_dev)
+{
+ bool is_assoc;
+
+ mutex_lock(&wpan_dev->association_lock);
+ is_assoc = !list_empty(&wpan_dev->children) || wpan_dev->parent;
+ mutex_unlock(&wpan_dev->association_lock);
+
+ return is_assoc;
+}
+
+bool cfg802154_device_is_parent(struct wpan_dev *wpan_dev,
+ struct ieee802154_addr *target)
+{
+ lockdep_assert_held(&wpan_dev->association_lock);
+
+ if (cfg802154_same_addr(wpan_dev->parent, target))
+ return true;
+
+ return false;
+}
+
+struct ieee802154_pan_device *
+cfg802154_device_is_child(struct wpan_dev *wpan_dev,
+ struct ieee802154_addr *target)
+{
+ struct ieee802154_pan_device *child;
+
+ lockdep_assert_held(&wpan_dev->association_lock);
+
+ list_for_each_entry(child, &wpan_dev->children, node)
+ if (cfg802154_same_addr(child, target))
+ return child;
+
+ return NULL;
+}
--
2.34.1