ieee802154: Add support for user beaconing requests

Parse user requests for sending beacons, start sending beacons at a
regular pace. If needed, the pace can be updated with a new request. The
process can also be interrupted at any moment.

The page and channel must be changed beforehands if needed. Interval
orders above 14 are reserved to tell a device it must answer BEACON_REQ
coming from another device as part of an active scan procedure and this
is not yet supported.

A netlink "beacon request" structure is created to list the
requirements.

Mac layers may now implement the ->send_beacons() and
->stop_beacons() hooks.

Co-developed-by: David Girault <david.girault@qorvo.com>
Signed-off-by: David Girault <david.girault@qorvo.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20230125102923.135465-2-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

1 files changed, 93 insertions, 0 deletions

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 0b7a9f16b3b6..8661907599e1 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -227,6 +227,7 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = {
 	[NL802154_ATTR_SCAN_MEAN_PRF] = { .type = NLA_U8 },
 	[NL802154_ATTR_SCAN_DURATION] = { .type = NLA_U8 },
 	[NL802154_ATTR_SCAN_DONE_REASON] = { .type = NLA_U8 },
+	[NL802154_ATTR_BEACON_INTERVAL] = { .type = NLA_U8 },
 
 #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
 	[NL802154_ATTR_SEC_ENABLED] = { .type = NLA_U8, },
@@ -1587,6 +1588,82 @@ static int nl802154_abort_scan(struct sk_buff *skb, struct genl_info *info)
 	return rdev_abort_scan(rdev, wpan_dev);
 }
 
+static int
+nl802154_send_beacons(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 cfg802154_beacon_request *request;
+	int err;
+
+	/* Only coordinators can send beacons */
+	if (wpan_dev->iftype != NL802154_IFTYPE_COORD)
+		return -EOPNOTSUPP;
+
+	if (wpan_dev->pan_id == cpu_to_le16(IEEE802154_PANID_BROADCAST)) {
+		pr_err("Device is not part of any PAN\n");
+		return -EPERM;
+	}
+
+	request = kzalloc(sizeof(*request), GFP_KERNEL);
+	if (!request)
+		return -ENOMEM;
+
+	request->wpan_dev = wpan_dev;
+	request->wpan_phy = wpan_phy;
+
+	if (info->attrs[NL802154_ATTR_BEACON_INTERVAL]) {
+		request->interval = nla_get_u8(info->attrs[NL802154_ATTR_BEACON_INTERVAL]);
+		if (request->interval > IEEE802154_MAX_SCAN_DURATION) {
+			pr_err("Interval is out of range\n");
+			err = -EINVAL;
+			goto free_request;
+		}
+	} else {
+		/* Use maximum duration order by default */
+		request->interval = IEEE802154_MAX_SCAN_DURATION;
+	}
+
+	if (wpan_dev->netdev)
+		dev_hold(wpan_dev->netdev);
+
+	err = rdev_send_beacons(rdev, request);
+	if (err) {
+		pr_err("Failure starting sending beacons (%d)\n", err);
+		goto free_device;
+	}
+
+	return 0;
+
+free_device:
+	if (wpan_dev->netdev)
+		dev_put(wpan_dev->netdev);
+free_request:
+	kfree(request);
+
+	return err;
+}
+
+void nl802154_beaconing_done(struct wpan_dev *wpan_dev)
+{
+	if (wpan_dev->netdev)
+		dev_put(wpan_dev->netdev);
+}
+EXPORT_SYMBOL_GPL(nl802154_beaconing_done);
+
+static int
+nl802154_stop_beacons(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;
+
+	/* Resources are released in the notification helper above */
+	return rdev_stop_beacons(rdev, wpan_dev);
+}
+
 #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 },
@@ -2693,6 +2770,22 @@ static const struct genl_ops nl802154_ops[] = {
 				  NL802154_FLAG_CHECK_NETDEV_UP |
 				  NL802154_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL802154_CMD_SEND_BEACONS,
+		.doit = nl802154_send_beacons,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = NL802154_FLAG_NEED_NETDEV |
+				  NL802154_FLAG_CHECK_NETDEV_UP |
+				  NL802154_FLAG_NEED_RTNL,
+	},
+	{
+		.cmd = NL802154_CMD_STOP_BEACONS,
+		.doit = nl802154_stop_beacons,
+		.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,