diff mbox series

[RFC,v1,03/10] net: qrtr: support identical node ids

Message ID 20241018181842.1368394-4-denkenz@gmail.com
State New
Headers show
Series [RFC,v1,01/10] net: qrtr: ns: validate msglen before ctrl_pkt use | expand

Commit Message

Denis Kenzior Oct. 18, 2024, 6:18 p.m. UTC 
Add support for tracking multiple endpoints that may have conflicting
node identifiers. This is achieved by using both the node and endpoint
identifiers as the key inside the radix_tree data structure.

For backward compatibility with existing clients, the previous key
schema (node identifier only) is preserved. However, this schema will
only support the first endpoint/node combination.  This is acceptable
for legacy clients as support for multiple endpoints with conflicting
node identifiers was not previously possible.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Andy Gross <agross@kernel.org>
---
 net/qrtr/af_qrtr.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

Comments

Denis Kenzior Oct. 22, 2024, 2:24 p.m. UTC | #1 
Hi Simon,

> 
> On systems with 32-bit longs, such as ARM, this will overflow.

Indeed.  I mentioned this in the cover letter.

Regards,
-Denis
diff mbox series

Patch

diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c
index be275871fb2a..e83d491a8da9 100644
--- a/net/qrtr/af_qrtr.c
+++ b/net/qrtr/af_qrtr.c
@@ -418,12 +418,20 @@  static struct qrtr_node *qrtr_node_lookup(unsigned int nid)
 static void qrtr_node_assign(struct qrtr_node *node, unsigned int nid)
 {
 	unsigned long flags;
+	unsigned long key;
 
 	if (nid == QRTR_EP_NID_AUTO)
 		return;
 
 	spin_lock_irqsave(&qrtr_nodes_lock, flags);
-	radix_tree_insert(&qrtr_nodes, nid, node);
+
+	/* Always insert with the endpoint_id + node_id */
+	key = (unsigned long)node->ep->id << 32 | nid;
+	radix_tree_insert(&qrtr_nodes, key, node);
+
+	if (!radix_tree_lookup(&qrtr_nodes, nid))
+		radix_tree_insert(&qrtr_nodes, nid, node);
+
 	if (node->nid == QRTR_EP_NID_AUTO)
 		node->nid = nid;
 	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);