diff mbox series

[wpan-next,09/11] mac802154: Follow the number of associated devices

Message ID 20230601154817.754519-10-miquel.raynal@bootlin.com (mailing list archive)
State Changes Requested
Headers show
Series ieee802154: Associations between devices | expand

Commit Message

Miquel Raynal June 1, 2023, 3:48 p.m. UTC 
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>
---
 include/net/cfg802154.h |  1 +
 net/ieee802154/core.c   |  1 +
 net/mac802154/cfg.c     |  1 +
 net/mac802154/scan.c    | 33 +++++++++++++++++++++++----------
 4 files changed, 26 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index d7583598b290..f18b93f9684f 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -507,6 +507,7 @@  struct wpan_dev {
 	struct list_head children;
 	unsigned int association_generation;
 	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 65bb656db9b4..6f7eecdc4067 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -212,6 +212,7 @@  static void cfg802154_free_peer_structures(struct wpan_dev *wpan_dev)
 		kfree(child);
 	}
 
+	wpan_dev->nchildren = 0;
 	wpan_dev->association_generation++;
 
 	mutex_unlock(&wpan_dev->association_lock);
diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
index c27c05e825ff..65a8806f9ddb 100644
--- a/net/mac802154/cfg.c
+++ b/net/mac802154/cfg.c
@@ -458,6 +458,7 @@  static int mac802154_disassociate_child(struct wpan_phy *wpan_phy,
 		return ret;
 
 	list_del(&child->node);
+	wpan_dev->nchildren--;
 	wpan_dev->association_generation++;
 	kfree(child);
 
diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c
index 9f55b2314fe5..fbbae7586ab1 100644
--- a/net/mac802154/scan.c
+++ b/net/mac802154/scan.c
@@ -801,20 +801,32 @@  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;
 	}
@@ -838,6 +850,7 @@  int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata,
 	}
 
 	list_add(&child->node, &wpan_dev->children);
+	wpan_dev->nchildren++;
 	wpan_dev->association_generation++;
 
 unlock: