Hi Mat, > Sometimes an ACL link must be raised to a higher security level after > an L2CAP connection is requested, but before a connection response is > sent. In this case, a connection response sent by L2CAP was not > immediately followed by a configuration request. Other code paths do > send this configuration request right away. It was possible for the > connection to stall while L2CAP waited for the remote device (like > PTS) to trigger the configuration process. > > Here is an abbreviated hcidump of the failure case with PTS: > > 1337806446.051982 > ACL data: handle 43 flags 0x02 dlen 10 > L2CAP(s): Info req: type 2 > 1337806446.052050 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Info rsp: type 2 result 0 > Extended feature mask 0x000000b8 > 1337806446.595320 > ACL data: handle 43 flags 0x02 dlen 12 > L2CAP(s): Connect req: psm 4097 scid 0x0041 > 1337806446.595673 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0041 result 1 status 0 > 1337806446.595679 < ACL data: handle 43 flags 0x00 dlen 10 > L2CAP(s): Info req: type 2 > 1337806446.669835 > ACL data: handle 43 flags 0x02 dlen 16 > L2CAP(s): Info rsp: type 2 result 0 > Extended feature mask 0x00000028 > 1337806446.669899 < HCI Command: Authentication Requested (0x01|0x0011) plen 2 > 1337806446.669906 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0041 result 1 status 1 > <security setup here> > 1337806446.769888 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0041 result 0 status 0 > > At this point, the connection stalls and no further messages are sent > on the L2CAP signaling channel. No data is received either. > > If we immediately send a configuration request after a successful connect > response, the connection completes: > > 1337724090.041162 > ACL data: handle 43 flags 0x02 dlen 10 > L2CAP(s): Info req: type 2 > 1337724090.041236 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Info rsp: type 2 result 0 > Extended feature mask 0x000000b8 > 1337724090.597128 > ACL data: handle 43 flags 0x02 dlen 12 > L2CAP(s): Connect req: psm 4097 scid 0x0041 > 1337724090.597236 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0041 result 1 status 0 > 1337724090.597244 < ACL data: handle 43 flags 0x00 dlen 10 > L2CAP(s): Info req: type 2 > 1337724090.660842 > ACL data: handle 43 flags 0x02 dlen 16 > L2CAP(s): Info rsp: type 2 result 0 > Extended feature mask 0x00000028 > 1337724090.660926 < HCI Command: Authentication Requested (0x01|0x0011) plen 2 > 1337724090.660934 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0041 result 1 status 1 > <security setup here> > 1337724090.755162 < ACL data: handle 43 flags 0x00 dlen 16 > L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0041 result 0 status 0 > 1337724090.755171 < ACL data: handle 43 flags 0x00 dlen 23 > L2CAP(s): Config req: dcid 0x0041 flags 0x00 clen 11 > 1337724091.361847 > ACL data: handle 43 flags 0x02 dlen 29 > L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 0 clen 15 > 1337724091.863808 > ACL data: handle 43 flags 0x02 dlen 23 > L2CAP(s): Config req: dcid 0x0040 flags 0x00 clen 11 > 1337724091.863882 < ACL data: handle 43 flags 0x00 dlen 29 > L2CAP(s): Config rsp: scid 0x0041 flags 0x00 result 0 clen 15 > 1337724092.683745 > ACL data: handle 43 flags 0x02 dlen 12 > L2CAP(d): cid 0x0040 len 8 [psm 4097] > 0000: 00 00 11 22 33 44 34 2f ..."3D4/ > > Signed-off-by: Mat Martineau <mathewm@xxxxxxxxxxxxxx> > --- > net/bluetooth/l2cap_core.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) thanks for adding the hcidump data. Patch has been applied to bluetooth-next tree. > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c > index e31b005..c9e6ae4 100644 > --- a/net/bluetooth/l2cap_core.c > +++ b/net/bluetooth/l2cap_core.c > @@ -5500,6 +5500,17 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt) > rsp.status = cpu_to_le16(stat); > l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, > sizeof(rsp), &rsp); > + We do have a coding style issue with the existing l2cap_send_cmd here. Is anybody going to fix that? Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
