gatt client clones break indication/confirmation

When bt_gatt_client receives 'indication' it sends 'confirmation'. 'confirmation' sending was broken after adding support for 'clones' of bt_gatt_client. In addition to first bt_gatt_client each clone also sends 'confirmation'.

# > ACL Data RX: Handle 69 flags 0x02 dlen 27
# ATT: Handle Value Indication (0x1d) len 22
# Handle: 0x001f
# Data: 68656c6c6f2027302e302e302e303a3532353332
# < ACL Data TX: Handle 69 flags 0x00 dlen 5
# ATT: Handle Value Confirmation (0x1e) len 0
# < ACL Data TX: Handle 69 flags 0x00 dlen 5
# ATT: Handle Value Confirmation (0x1e) len 0

Extra confirmation sent by clone confuses remote side. When bluetooth daemon receives extra confirmation it breaks connection.

Attached patch fixes the issue limiting confirmation sending to single bt_gatt_client.

From: "Mikhail I. Krivtsov" <[email protected]>
Date: Sat, 14 May 2016 11:37:30 +0300
Subject: [PATCH] shared/gatt-client: Fix sending confirmation

Confirmation shall be sent from topmost parent only. Extra confirmation sent by clone confuses remote side.

      ATT: Handle Value Indication (0x1d) len 22
        Handle: 0x001f
          Data: 68656c6c6f2027302e302e302e303a3532353332
< ACL Data TX: Handle 69 flags 0x00 dlen 5
      ATT: Handle Value Confirmation (0x1e) len 0
< ACL Data TX: Handle 69 flags 0x00 dlen 5
      ATT: Handle Value Confirmation (0x1e) len 0
---
 src/shared/gatt-client.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 84689f6..adabfe3 100644
@@ -1745,7 +1745,7 @@ static void notify_cb(uint8_t opcode, const void *pdu, uint16_t length,
 
 	queue_foreach(client->notify_list, notify_handler, &pdu_data);
 
-	if (opcode == BT_ATT_OP_HANDLE_VAL_IND)
+	if (opcode == BT_ATT_OP_HANDLE_VAL_IND && !client->parent)
 		bt_att_send(client->att, BT_ATT_OP_HANDLE_VAL_CONF, NULL, 0,
 							NULL, NULL, NULL);
 

2.7.3

Hi Mikhail,

I went ahead and applied this fix, thanks for the contribution.

*Next time please do follow the instruction under HACKING and send as a proper patch.

Luiz Augusto von Dentz