From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
This adds auto retry logic to requests when a security error happen,
it will first attempt to elevate the security to match the requirement
and then retry sending the request once again.
---
src/shared/att.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 54 insertions(+), 4 deletions(-)
diff --git a/src/shared/att.c b/src/shared/att.c
index f9a5817..e8be4cc 100644
--- a/src/shared/att.c
+++ b/src/shared/att.c
@@ -576,6 +576,55 @@ static bool disconnect_cb(struct io *io, void *user_data)
return false;
}
+static bool change_security(struct bt_att *att, uint8_t ecode)
+{
+ int security;
+
+ security = bt_att_get_security(att);
+ if (ecode == BT_ATT_ERROR_INSUFFICIENT_ENCRYPTION &&
+ security < BT_ATT_SECURITY_MEDIUM)
+ security = BT_ATT_SECURITY_MEDIUM;
+ else if (ecode == BT_ATT_ERROR_AUTHENTICATION &&
+ security < BT_ATT_SECURITY_HIGH)
+ security = BT_ATT_SECURITY_HIGH;
+ else
+ return false;
+
+ return bt_att_set_security(att, security);
+}
+
+static bool handle_error_rsp(struct bt_att *att, uint8_t *pdu,
+ ssize_t pdu_len, uint8_t *opcode)
+{
+ const struct bt_att_pdu_error_rsp *rsp;
+ struct att_send_op *op = att->pending_req;
+
+ if (pdu_len != sizeof(*rsp)) {
+ *opcode = 0;
+ return false;
+ }
+
+ rsp = (void *) pdu;
+
+ *opcode = rsp->opcode;
+
+ /* Only try to change security on L2CAP */
+ if (!att->io_on_l2cap)
+ return false;
+
+ /* Attempt to change security */
+ if (!change_security(att, rsp->ecode))
+ return false;
+
+ util_debug(att->debug_callback, att->debug_data,
+ "Retrying operation %p", op);
+
+ att->pending_req = NULL;
+
+ /* Push operation back to request queue */
+ return queue_push_head(att->req_queue, op);
+}
+
static void handle_rsp(struct bt_att *att, uint8_t opcode, uint8_t *pdu,
ssize_t pdu_len)
{
@@ -601,10 +650,11 @@ static void handle_rsp(struct bt_att *att, uint8_t opcode, uint8_t *pdu,
* the request is malformed, end the current request with failure.
*/
if (opcode == BT_ATT_OP_ERROR_RSP) {
- if (pdu_len != 4)
- goto fail;
-
- req_opcode = pdu[0];
+ /* Return if error response cause a retry */
+ if (handle_error_rsp(att, pdu, pdu_len, &req_opcode)) {
+ wakeup_writer(att);
+ return;
+ }
} else if (!(req_opcode = get_req_opcode(opcode)))
goto fail;
--
2.1.0
--
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