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Date: Tue, 30 Jan 2024 18:24:59 +0800
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Message-ID: <20240130182459.Bluez.v2.1.If74ccbca4d541c5f576765a3a78cb8923b5f85b1@changeid>
Subject: [Bluez PATCH v2 1/2] Monitor: Remove handle before assigning
From: Archie Pusaka <apusaka@google.com>
To: linux-bluetooth <linux-bluetooth@vger.kernel.org>, 
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>, Johan Hedberg <johan.hedberg@gmail.com>, 
	Marcel Holtmann <marcel@holtmann.org>
Cc: CrosBT Upstreaming <chromeos-bluetooth-upstreaming@chromium.org>, 
	Archie Pusaka <apusaka@chromium.org>, Zhengping Jiang <jiangzp@google.com>
Content-Type: text/plain; charset="UTF-8"

From: Archie Pusaka <apusaka@chromium.org>

It is possible to have some handles not removed, for example the host
may decide not to wait for disconnection complete event when it is
suspending. In this case, when the peer device reconnected, we might
have two of the some handle assigned and create problem down the road.

This patch solves the issue by always removing any previous handles
when assigning a new handle if they are the same.

Reviewed-by: Zhengping Jiang <jiangzp@google.com>

---

Changes in v2:
* Return connection pointer when removing handle

 monitor/packet.c | 79 ++++++++++++++++++++++++++----------------------
 1 file changed, 43 insertions(+), 36 deletions(-)

diff --git a/monitor/packet.c b/monitor/packet.c
index 42e711cafa..164cc82bb2 100644
--- a/monitor/packet.c
+++ b/monitor/packet.c
@@ -189,59 +189,66 @@ static struct packet_conn_data *lookup_parent(uint16_t handle)
 	return NULL;
 }
 
-static void assign_handle(uint16_t index, uint16_t handle, uint8_t type,
-					uint8_t *dst, uint8_t dst_type)
+static struct packet_conn_data *release_handle(uint16_t handle)
 {
 	int i;
 
 	for (i = 0; i < MAX_CONN; i++) {
-		if (conn_list[i].handle == 0xffff) {
-			hci_devba(index, (bdaddr_t *)conn_list[i].src);
+		struct packet_conn_data *conn = &conn_list[i];
+
+		if (conn->handle == handle) {
+			if (conn->destroy)
+				conn->destroy(conn->data);
 
-			conn_list[i].index = index;
-			conn_list[i].handle = handle;
-			conn_list[i].type = type;
+			queue_destroy(conn->tx_q, free);
+			queue_destroy(conn->chan_q, free);
+			memset(conn, 0, sizeof(*conn));
+			conn->handle = 0xffff;
+			return conn;
+		}
+	}
 
-			if (!dst) {
-				struct packet_conn_data *p;
+	return NULL;
+}
 
-				/* If destination is not set attempt to use the
-				 * parent one if that exists.
-				 */
-				p = lookup_parent(handle);
-				if (p) {
-					memcpy(conn_list[i].dst, p->dst,
-						sizeof(conn_list[i].dst));
-					conn_list[i].dst_type = p->dst_type;
-				}
+static void assign_handle(uint16_t index, uint16_t handle, uint8_t type,
+					uint8_t *dst, uint8_t dst_type)
+{
+	struct packet_conn_data *conn = release_handle(handle);
+	int i;
 
+	if (!conn) {
+		for (i = 0; i < MAX_CONN; i++) {
+			if (conn_list[i].handle == 0xffff) {
+				conn = &conn_list[i];
 				break;
 			}
-
-			memcpy(conn_list[i].dst, dst, sizeof(conn_list[i].dst));
-			conn_list[i].dst_type = dst_type;
-			break;
 		}
 	}
-}
 
-static void release_handle(uint16_t handle)
-{
-	int i;
+	if (!conn)
+		return;
 
-	for (i = 0; i < MAX_CONN; i++) {
-		struct packet_conn_data *conn = &conn_list[i];
+	hci_devba(index, (bdaddr_t *)conn->src);
 
-		if (conn->handle == handle) {
-			if (conn->destroy)
-				conn->destroy(conn->data);
+	conn->index = index;
+	conn->handle = handle;
+	conn->type = type;
 
-			queue_destroy(conn->tx_q, free);
-			queue_destroy(conn->chan_q, free);
-			memset(conn, 0, sizeof(*conn));
-			conn->handle = 0xffff;
-			break;
+	if (!dst) {
+		struct packet_conn_data *p;
+
+		/* If destination is not set attempt to use the parent one if
+		 * that exists.
+		 */
+		p = lookup_parent(handle);
+		if (p) {
+			memcpy(conn->dst, p->dst, sizeof(conn->dst));
+			conn->dst_type = p->dst_type;
 		}
+	} else {
+		memcpy(conn->dst, dst, sizeof(conn->dst));
+		conn->dst_type = dst_type;
 	}
 }
 
-- 
2.43.0.429.g432eaa2c6b-goog