Re: [PATCH 2/2] Bluetooth: Fix authentication if acl data comes before remote feature evt

[Johan Hedberg <johan.hedberg@gmail.com>]

Hi Jaganath,

On Thu, Jan 03, 2013, Jaganath Kanakkassery wrote:
> If remote device sends l2cap info request before read_remote_ext_feature
> completes then mgmt_connected will be sent in hci_acldata_packet() and
> remote name request wont be sent and eventually authentication wont happen
> 
> Hcidump log of the issue
> 
> < HCI Command: Create Connection (0x01|0x0005) plen 13
>     bdaddr BC:85:1F:74:7F:29 ptype 0xcc18 rswitch 0x01 clkoffset 0x4bf7 (valid)
>     Packet type: DM1 DM3 DM5 DH1 DH3 DH5
> > HCI Event: Command Status (0x0f) plen 4
>     Create Connection (0x01|0x0005) status 0x00 ncmd 1
> > HCI Event: Connect Complete (0x03) plen 11
>     status 0x00 handle 12 bdaddr BC:85:1F:74:7F:29 type ACL encrypt 0x00
> < HCI Command: Read Remote Supported Features (0x01|0x001b) plen 2
>     handle 12
> > HCI Event: Command Status (0x0f) plen 4
>     Read Remote Supported Features (0x01|0x001b) status 0x00 ncmd 1
> > HCI Event: Read Remote Supported Features (0x0b) plen 11
>     status 0x00 handle 12
>     Features: 0xbf 0xfe 0xcf 0xfe 0xdb 0xff 0x7b 0x87
> > HCI Event: Max Slots Change (0x1b) plen 3
>     handle 12 slots 5
> < HCI Command: Read Remote Extended Features (0x01|0x001c) plen 3
>     handle 12 page 1
> > HCI Event: Command Status (0x0f) plen 4
>     Read Remote Extended Features (0x01|0x001c) status 0x00 ncmd 1
> > ACL data: handle 12 flags 0x02 dlen 10
>     L2CAP(s): Info req: type 2
> < ACL data: handle 12 flags 0x00 dlen 16
>     L2CAP(s): Info rsp: type 2 result 0
>       Extended feature mask 0x00b8
>         Enhanced Retransmission mode
>         Streaming mode
>         FCS Option
>         Fixed Channels
> > HCI Event: Read Remote Extended Features (0x23) plen 13
>     status 0x00 handle 12 page 1 max 1
>     Features: 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00
> > ACL data: handle 12 flags 0x02 dlen 10
>     L2CAP(s): Info req: type 3
> < ACL data: handle 12 flags 0x00 dlen 20
>     L2CAP(s): Info rsp: type 3 result 0
>       Fixed channel list 0x00000002
>         L2CAP Signalling Channel
> > HCI Event: Number of Completed Packets (0x13) plen 5
>     handle 12 packets 2
> 
> Signed-off-by: Jaganath Kanakkassery <jaganath.k@samsung.com>
> ---
>  net/bluetooth/hci_core.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 596660d..c14def9 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -2812,6 +2812,7 @@ static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb)
>  
>  		hci_dev_lock(hdev);
>  		if (test_bit(HCI_MGMT, &hdev->dev_flags) &&
> +		    !hci_outgoing_auth_needed(hdev, conn) &&
>  		    !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &conn->flags))
>  			mgmt_device_connected(hdev, &conn->dst, conn->type,
>  					      conn->dst_type, 0, NULL, 0,

I'm not completely sure if this is the right way or even the right place
to fix the issue. The reason why this if-clause is here is so that we
don't get a too late mgmt_connected event in case the remote device is
fast in sending an L2CAP Connect Request. Maybe if-clause needs to be
made L2CAP Connect request specific (and moved to an L2CAP specific
location) or then something added to the code path taken for the info
request?

Johan