Removing a bond and disconnecting from a specific remote device
can cause l2cap_chan_send() is called after l2cap_chan_del() is
called. This causes following crash.

[ 1384.972086] Unable to handle kernel NULL pointer dereference at virtual address 00000008
[ 1384.972090] pgd = c0004000
[ 1384.972125] [00000008] *pgd=00000000
[ 1384.972137] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[ 1384.972144] Modules linked in:
[ 1384.972156] CPU: 0 PID: 841 Comm: krfcommd Not tainted 3.10.14-gdf22a71-dirty #435
[ 1384.972162] task: df29a100 ti: df178000 task.ti: df178000
[ 1384.972182] PC is at l2cap_create_basic_pdu+0x30/0x1ac
[ 1384.972191] LR is at l2cap_chan_send+0x100/0x1d4
[ 1384.972198] pc : [<c051d250>]    lr : [<c0521c78>]    psr: 40000113
[ 1384.972198] sp : df179d40  ip : c083a010  fp : 00000008
[ 1384.972202] r10: 00000004  r9 : 0000065a  r8 : 000003f5
[ 1384.972206] r7 : 00000000  r6 : 00000000  r5 : df179e84  r4 : da557000
[ 1384.972210] r3 : 00000000  r2 : 00000004  r1 : df179e84  r0 : 00000000
[ 1384.972215] Flags: nZcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[ 1384.972220] Control: 10c53c7d  Table: 5c8b004a  DAC: 00000015
[ 1384.972224] Process krfcommd (pid: 841, stack limit = 0xdf178238)
[ 1384.972229] Stack: (0xdf179d40 to 0xdf17a000)
[ 1384.972238] 9d40: 00000000 da557000 00000004 df179e84 00000004 000003f5 0000065a 00000000
[ 1384.972245] 9d60: 00000008 c0521c78 df179e84 da557000 00000004 da557204 de0c6800 df179e84
[ 1384.972253] 9d80: da557000 00000004 da557204 c0526b7c 00000004 df724000 df179e84 00000004
[ 1384.972260] 9da0: df179db0 df29a100 c083bc48 c045481c 00000001 00000000 00000000 00000000
[ 1384.972267] 9dc0: 00000000 df29a100 00000000 00000000 00000000 00000000 df179e10 00000000
[ 1384.972274] 9de0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 1384.972281] 9e00: 00000000 00000000 00000000 00000000 df179e4c c000ec80 c0b538c0 00000004
[ 1384.972288] 9e20: df724000 df178000 00000000 df179e84 c0b538c0 00000000 df178000 c07f4570
[ 1384.972295] 9e40: dcad9c00 df179e74 c07f4394 df179e60 df178000 00000000 df179e84 de247010
[ 1384.972303] 9e60: 00000043 c0454dec 00000001 00000004 df315c00 c0530598 00000004 df315c0c
[ 1384.972310] 9e80: ffffc32c 00000000 00000000 df179ea0 00000001 00000000 00000000 00000000
[ 1384.972317] 9ea0: df179ebc 00000004 df315c00 c05df838 00000000 c0530810 c07d08c0 d7017303
[ 1384.972325] 9ec0: 6ec245b9 00000000 df315c00 c0531b04 c07f3fe0 c07f4018 da67a300 df315c00
[ 1384.972332] 9ee0: 00000000 c05334e0 df315c00 df315b80 df315c00 de0c6800 da67a300 00000000
[ 1384.972339] 9f00: de0c684c c0533674 df204100 df315c00 df315c00 df204100 df315c00 c082b138
[ 1384.972347] 9f20: c053385c c0533754 a0000113 df178000 00000001 c083bc48 00000000 c053385c
[ 1384.972354] 9f40: 00000000 00000000 00000000 c05338c4 00000000 df9f0000 df9f5ee4 df179f6c
[ 1384.972360] 9f60: df178000 c0049db4 00000000 00000000 c07f3ff8 00000000 00000000 00000000
[ 1384.972368] 9f80: df179f80 df179f80 00000000 00000000 df179f90 df179f90 df9f5ee4 c0049cfc
[ 1384.972374] 9fa0: 00000000 00000000 00000000 c000f168 00000000 00000000 00000000 00000000
[ 1384.972381] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 1384.972388] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00010000 00000600
[ 1384.972411] [<c051d250>] (l2cap_create_basic_pdu+0x30/0x1ac) from [<c0521c78>] (l2cap_chan_send+0x100/0x1d4)
[ 1384.972425] [<c0521c78>] (l2cap_chan_send+0x100/0x1d4) from [<c0526b7c>] (l2cap_sock_sendmsg+0xa8/0x104)
[ 1384.972440] [<c0526b7c>] (l2cap_sock_sendmsg+0xa8/0x104) from [<c045481c>] (sock_sendmsg+0xac/0xcc)
[ 1384.972453] [<c045481c>] (sock_sendmsg+0xac/0xcc) from [<c0454dec>] (kernel_sendmsg+0x2c/0x34)
[ 1384.972469] [<c0454dec>] (kernel_sendmsg+0x2c/0x34) from [<c0530598>] (rfcomm_send_frame+0x58/0x7c)
[ 1384.972481] [<c0530598>] (rfcomm_send_frame+0x58/0x7c) from [<c0530810>] (rfcomm_send_ua+0x98/0xbc)
[ 1384.972494] [<c0530810>] (rfcomm_send_ua+0x98/0xbc) from [<c0531b04>] (rfcomm_recv_disc+0xac/0x100)
[ 1384.972506] [<c0531b04>] (rfcomm_recv_disc+0xac/0x100) from [<c05334e0>] (rfcomm_recv_frame+0x144/0x264)
[ 1384.972519] [<c05334e0>] (rfcomm_recv_frame+0x144/0x264) from [<c0533674>] (rfcomm_process_rx+0x74/0xfc)
[ 1384.972531] [<c0533674>] (rfcomm_process_rx+0x74/0xfc) from [<c0533754>] (rfcomm_process_sessions+0x58/0x160)
[ 1384.972543] [<c0533754>] (rfcomm_process_sessions+0x58/0x160) from [<c05338c4>] (rfcomm_run+0x68/0x110)
[ 1384.972558] [<c05338c4>] (rfcomm_run+0x68/0x110) from [<c0049db4>] (kthread+0xb8/0xbc)
[ 1384.972576] [<c0049db4>] (kthread+0xb8/0xbc) from [<c000f168>] (ret_from_fork+0x14/0x2c)
[ 1384.972586] Code: e3100004 e1a07003 e5946000 1a000057 (e5969008)
[ 1384.972614] ---[ end trace 6170b7ce00144e8c ]---
Signed-off-by: NSeung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

For certain devices (ex: HID mouse), support for authentication,
pairing and bonding is optional. For such devices, the ACL alive
for too long after the L2CAP disconnection.

To avoid the ACL alive for too long after L2CAP disconnection, reset the
ACL disconnect timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.

While merging the commit id:a9ea3ed9
this issue might have introduced.

Hcidump info:
sh-4.1# /opt/hcidump -Xt
2013-08-05 16:49:00.894129 < ACL data: handle 12 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x004a scid 0x0041
2013-08-05 16:49:00.894195 < HCI Command: Exit Sniff Mode (0x02|0x0004)
    plen 2
    handle 12
2013-08-05 16:49:00.894269 < ACL data: handle 12 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x0049 scid 0x0040
2013-08-05 16:49:00.895645 > HCI Event: Command Status (0x0f) plen 4
    Exit Sniff Mode (0x02|0x0004) status 0x00 ncmd 1
2013-08-05 16:49:00.934391 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:49:00.936592 > HCI Event: Number of Completed Packets
    (0x13) plen 5
    handle 12 packets 2
2013-08-05 16:49:00.951577 > ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x004a scid 0x0041
2013-08-05 16:49:00.952820 > ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x0049 scid 0x0040
2013-08-05 16:49:00.969165 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x02 interval 50
    Mode: Sniff

2013-08-05 16:49:48.175533 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:49:48.219045 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x02 interval 108
    Mode: Sniff

2013-08-05 16:51:00.968209 < HCI Command: Disconnect (0x01|0x0006) plen 3
    handle 12 reason 0x13
    Reason: Remote User Terminated Connection
2013-08-05 16:51:00.969056 > HCI Event: Command Status (0x0f) plen 4
    Disconnect (0x01|0x0006) status 0x00 ncmd 1
2013-08-05 16:51:01.013495 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 12 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:51:01.073777 > HCI Event: Disconn Complete (0x05) plen 4
    status 0x00 handle 12 reason 0x16
    Reason: Connection Terminated by Local Host

============================ After  fix ================================

2013-08-05 16:57:35.986648 < ACL data: handle 11 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x004c scid 0x0041
2013-08-05 16:57:35.986713 < HCI Command: Exit Sniff Mode (0x02|0x0004)
    plen 2
    handle 11
2013-08-05 16:57:35.986785 < ACL data: handle 11 flags 0x00 dlen 12
    L2CAP(s): Disconn req: dcid 0x004b scid 0x0040
2013-08-05 16:57:35.988110 > HCI Event: Command Status (0x0f) plen 4
    Exit Sniff Mode (0x02|0x0004) status 0x00 ncmd 1
2013-08-05 16:57:36.030714 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 11 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:57:36.032950 > HCI Event: Number of Completed Packets
    (0x13) plen 5
    handle 11 packets 2
2013-08-05 16:57:36.047926 > ACL data: handle 11 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x004c scid 0x0041
2013-08-05 16:57:36.049200 > ACL data: handle 11 flags 0x02 dlen 12
    L2CAP(s): Disconn rsp: dcid 0x004b scid 0x0040
2013-08-05 16:57:36.065509 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 11 mode 0x02 interval 50
    Mode: Sniff

2013-08-05 16:57:40.052006 < HCI Command: Disconnect (0x01|0x0006) plen 3
    handle 11 reason 0x13
    Reason: Remote User Terminated Connection
2013-08-05 16:57:40.052869 > HCI Event: Command Status (0x0f) plen 4
    Disconnect (0x01|0x0006) status 0x00 ncmd 1
2013-08-05 16:57:40.104731 > HCI Event: Mode Change (0x14) plen 6
    status 0x00 handle 11 mode 0x00 interval 0
    Mode: Active
2013-08-05 16:57:40.146935 > HCI Event: Disconn Complete (0x05) plen 4
    status 0x00 handle 11 reason 0x16
    Reason: Connection Terminated by Local Host
Signed-off-by: NSang-Ki Park <sangki79.park@samsung.com>
Signed-off-by: NChan-yeol Park <chanyeol.park@samsung.com>
Signed-off-by: NJaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: NSzymon Janc <szymon.janc@tieto.com>
Signed-off-by: NSyam Sidhardhan <s.syam@samsung.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The length check is invalid since the length varies with type of
info response.

This was introduced by the commit cb3b3152

Because of this, l2cap info rsp is not handled and command reject is sent.

> ACL data: handle 11 flags 0x02 dlen 16
        L2CAP(s): Info rsp: type 2 result 0
          Extended feature mask 0x00b8
            Enhanced Retransmission mode
            Streaming mode
            FCS Option
            Fixed Channels
< ACL data: handle 11 flags 0x00 dlen 10
        L2CAP(s): Command rej: reason 0
          Command not understood

Cc: stable@vger.kernel.org
Signed-off-by: NJaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: NChan-Yeol Park <chanyeol.park@samsung.com>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Trivial change in the coding style.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The length check is invalid since the length varies with type of
info response.

This was introduced by the commit cb3b3152

Because of this, l2cap info rsp is not handled and command reject is sent.

> ACL data: handle 11 flags 0x02 dlen 16
        L2CAP(s): Info rsp: type 2 result 0
          Extended feature mask 0x00b8
            Enhanced Retransmission mode
            Streaming mode
            FCS Option
            Fixed Channels
< ACL data: handle 11 flags 0x00 dlen 10
        L2CAP(s): Command rej: reason 0
          Command not understood

Cc: stable@vger.kernel.org
Signed-off-by: NJaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: NChan-Yeol Park <chanyeol.park@samsung.com>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The LE ATT server socket needs to be superseded by any ATT client
sockets. Previously this was done by looking at the hcon->out variable
(indicating whether the connection is outgoing or incoming) which is a
too crude way of determining whether the server socket needs to be
picked or not (an outgoing connection doesn't necessarily mean that an
ATT client socket has triggered it).

This patch extends the ATT server socket lookup function
(l2cap_le_conn_ready) to be used for all LE connections (regardless of
the hcon->out value) and adds an internal check into the function for
the existence of any ATT client sockets (in which case the server socket
should be skipped). For this to work reliably all lookups must be done
while the l2cap_conn->chan_lock is held, meaning also that the call to
l2cap_chan_add needs to be changed to its lockless __l2cap_chan_add
counterpart.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

There's no need to reset disc_timeout in l2cap_le_conn_ready since
HCI_DISCONN_TIMEOUT is the default when the hci_conn is created and
there should be no way for it to get changed between creation and
l2cap_le_conn_ready being called.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The L2CAP code has been incrementing the hci_conn reference for each
l2cap_chan instance in the l2cap_conn list. Likewise, the reference is
dropped each time an l2cap_chan is removed from the list. The reference
counting policy with respect to removal has been clear and explicit in
the l2cap_chan_del function, however for addition the function
calling 2cap_chan_add has always had to do a separate hci_conn_hold
call.

What made the counting even more hard to follow is that the
hci_connect() procedure increments the reference and the L2CAP layer
making this call took advantage of it to use it as its own reference.

This patch aims to clarify things by having the call to hci_conn_hold
inside __l2cap_chan_add, thereby removing the need to do it in the
functions calling __l2cap_chan_add. The reference count for hci_connect
is still kept as it's necessary for users such as mgmt_pair_device,
however for the L2CAP layer it means that an extra call to hci_conn_drop
must be performed once l2cap_chan_add has been done.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

In l2cap_att_channel() we're only interested in the BT_CONNECTED state
so this state can directly be passed to l2cap_global_chan_by_scid().
This way there's no need to do any additional state check later.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The sk variable is of quite little use since it's only used to simplify
access in the two bt_sk() calls.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

In l2cap_le_conn_ready() after doing l2cap_chann_add() the LE channel is
part of the list which is subsequently iterated in l2cap_conn_ready() in
this loop each channel will get l2cap_chan_ready() called which would
result in trying to set the channel two times into BT_CONNECTED state.
Instead it makes sense to just add the channel but not call chan_ready
in l2cap_le_conn_ready, which is what this patch does.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

There is an extra call to smp_conn_security() for outgoing LE
connections from l2cap_conn_ready() but the reason for this call is far
from clear. After a bit of commit history research and using git blame I
found out that this extra call is for socket-less pairing processes
added by commit 160dc6ac. This patch adds a clarifying comment to the
code for this.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Since in the future more than the ATT CID may be permissible we should
not be hardcoding it for all LE connections in __l2cap_chan_add().
Instead, the source ATT CID should only be set if the destination is
also ATT, and in other cases we should just use the existing dynamic CID
allocation function.

Assigning scid based on dcid means that whenever __l2cap_chan_add() is
called that chan->dcid is properly initialized. l2cap_le_conn_ready()
wasn't initializing is properly so this is also taken care of in this
patch.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The current test in l2cap_chan_connect is intended to protect against
multiple conflicting connect attempts. However, it assumes that there
will ever only be a single CID that is connected to, which is not true.
We do need to check for conflicts with connect attempts to the same
destination CID but this check is not in anyway specific to LE but can
be applied to BR/EDR as well.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The choice between LE and BR/EDR should be made on the destination
address type instead of the destination CID. This is particularly
important when in the future more than one CID will be allowed for LE.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

In future Core Specification versions the ATT CID will be just one of
many possible CIDs that can be used for data transfer. Therefore, it
makes sense to rename the define for the ATT CID to something less
ambigous.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The LE L2CAP signalling channel follows its own rules and will continue
to evolve independently from the BR/EDR signalling channel. Therefore,
it makes sense to have a clear split from BR/EDR by having a dedicated
function for handling LE signalling commands.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

If a too small MTU value is set with ioctl(HCISETACLMTU) or by a bogus
controller, memory corruption happens due to a memcpy() call with
negative length.

Fix this crash on either incoming or outgoing connections with a MTU
smaller than L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE:

[   46.885433] BUG: unable to handle kernel paging request at f56ad000
[   46.888037] IP: [<c03d94cd>] memcpy+0x1d/0x40
[   46.888037] *pdpt = 0000000000ac3001 *pde = 00000000373f8067 *pte = 80000000356ad060
[   46.888037] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
[   46.888037] Modules linked in: hci_vhci bluetooth virtio_balloon i2c_piix4 uhci_hcd usbcore usb_common
[   46.888037] CPU: 0 PID: 1044 Comm: kworker/u3:0 Not tainted 3.10.0-rc1+ #12
[   46.888037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   46.888037] Workqueue: hci0 hci_rx_work [bluetooth]
[   46.888037] task: f59b15b0 ti: f55c4000 task.ti: f55c4000
[   46.888037] EIP: 0060:[<c03d94cd>] EFLAGS: 00010212 CPU: 0
[   46.888037] EIP is at memcpy+0x1d/0x40
[   46.888037] EAX: f56ac1c0 EBX: fffffff8 ECX: 3ffffc6e EDX: f55c5cf2
[   46.888037] ESI: f55c6b32 EDI: f56ad000 EBP: f55c5c68 ESP: f55c5c5c
[   46.888037]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[   46.888037] CR0: 8005003b CR2: f56ad000 CR3: 3557d000 CR4: 000006f0
[   46.888037] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[   46.888037] DR6: ffff0ff0 DR7: 00000400
[   46.888037] Stack:
[   46.888037]  fffffff8 00000010 00000003 f55c5cac f8c6a54c ffffffff f8c69eb2 00000000
[   46.888037]  f4783cdc f57f0070 f759c590 1001c580 00000003 0200000a 00000000 f5a88560
[   46.888037]  f5ba2600 f5a88560 00000041 00000000 f55c5d90 f8c6f4c7 00000008 f55c5cf2
[   46.888037] Call Trace:
[   46.888037]  [<f8c6a54c>] l2cap_send_cmd+0x1cc/0x230 [bluetooth]
[   46.888037]  [<f8c69eb2>] ? l2cap_global_chan_by_psm+0x152/0x1a0 [bluetooth]
[   46.888037]  [<f8c6f4c7>] l2cap_connect+0x3f7/0x540 [bluetooth]
[   46.888037]  [<c019b37b>] ? trace_hardirqs_off+0xb/0x10
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064ad20>] ? mutex_lock_nested+0x280/0x360
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<c064ad08>] ? mutex_lock_nested+0x268/0x360
[   46.888037]  [<c01a125b>] ? trace_hardirqs_on+0xb/0x10
[   46.888037]  [<f8c72f8d>] l2cap_recv_frame+0xb2d/0x1d30 [bluetooth]
[   46.888037]  [<c01a0ff8>] ? mark_held_locks+0x68/0x110
[   46.888037]  [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150
[   46.888037]  [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0
[   46.888037]  [<f8c754f1>] l2cap_recv_acldata+0x2a1/0x320 [bluetooth]
[   46.888037]  [<f8c491d8>] hci_rx_work+0x518/0x810 [bluetooth]
[   46.888037]  [<f8c48df2>] ? hci_rx_work+0x132/0x810 [bluetooth]
[   46.888037]  [<c0158979>] process_one_work+0x1a9/0x600
[   46.888037]  [<c01588fb>] ? process_one_work+0x12b/0x600
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c015922e>] ? worker_thread+0x19e/0x320
[   46.888037]  [<c0159187>] worker_thread+0xf7/0x320
[   46.888037]  [<c0159090>] ? rescuer_thread+0x290/0x290
[   46.888037]  [<c01602f8>] kthread+0xa8/0xb0
[   46.888037]  [<c0656777>] ret_from_kernel_thread+0x1b/0x28
[   46.888037]  [<c0160250>] ? flush_kthread_worker+0x120/0x120
[   46.888037] Code: c3 90 8d 74 26 00 e8 63 fc ff ff eb e8 90 55 89 e5 83 ec 0c 89 5d f4 89 75 f8 89 7d fc 3e 8d 74 26 00 89 cb 89 c7 c1 e9 02 89 d6 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 5d f4 8b 75 f8 8b 7d fc 89
[   46.888037] EIP: [<c03d94cd>] memcpy+0x1d/0x40 SS:ESP 0068:f55c5c5c
[   46.888037] CR2: 00000000f56ad000
[   46.888037] ---[ end trace 0217c1f4d78714a9 ]---
Signed-off-by: NAnderson Lizardo <anderson.lizardo@openbossa.org>
Cc: stable@vger.kernel.org
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There has been code in place to check that the L2CAP length header
matches the amount of data received, but many PDU handlers have not been
checking that the data received actually matches that expected by the
specific PDU. This patch adds passing the length header to the specific
handler functions and ensures that those functions fail cleanly in the
case of an incorrect amount of data.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The CID is fixed to L2CAP ATT channel and so there is no need to hand it
down to the handling function. Just use a constant instead.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Several sub-modules like HIDP, rfcomm, ... need to track l2cap
connections. The l2cap_conn->hcon->dev object is used as parent for sysfs
devices so the sub-modules need to be notified when the hci_conn object is
removed from sysfs.

As submodules normally use the l2cap layer, the l2cap_user objects are
registered there instead of on the underlying hci_conn object. This avoids
any direct dependency on the HCI layer and lets the l2cap core handle any
specifics.

This patch introduces l2cap_user objects which contain a "probe" and
"remove" callback. You can register them on any l2cap_conn object and if
it is active, the "probe" callback will get called. Otherwise, an error is
returned.

The l2cap_conn object will call your "remove" callback directly before it
is removed from user-space. This allows you to remove your submodules
_before_ the parent l2cap_conn and hci_conn object is removed.

At any time you can asynchronously unregister your l2cap_user object if
your submodule vanishes before the l2cap_conn object does.

There is no way around l2cap_user. If we want wire-protocols in the
kernel, we always want the hci_conn object as parent in the sysfs tree. We
cannot use a channel here since we might need multiple channels for a
single protocol.
But the problem is, we _must_ get notified when an l2cap_conn object is
removed. We cannot use reference-counting for object-removal! This is not
how it works. If a hardware is removed, we should immediately remove the
object from sysfs. Any other behavior would be inconsistent with the rest
of the system. Also note that device_del() might sleep, but it doesn't
wait for user-space or block very long. It only _unlinks_ the object from
sysfs and the whole device-tree. Everything else is handled by ref-counts!
This is exactly what the other sub-modules must do: unlink their devices
when the "remove" l2cap_user callback is called. They should not do any
cleanup or synchronous shutdowns.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

If we want to use l2cap_conn outside of l2cap_core.c, we need refcounting
for these objects. Otherwise, we cannot synchronize l2cap locks with
outside locks and end up with deadlocks.

Hence, introduce ref-counting for l2cap_conn objects. This doesn't affect
l2cap internals at all, as they use a direct synchronization.
We also keep a reference to the parent hci_conn for locking purposes as
l2cap_conn depends on this. This doesn't affect the connection itself but
only the lifetime of the (dead) object.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

This patch removes the status parameter of the l2cap_conn_add function.
The parameter 'status' is always 0.
Signed-off-by: NClaudio Takahasi <claudio.takahasi@openbossa.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

We use _get() and _put() for device ref-counting in the kernel. However,
hci_conn_put() is _not_ used for ref-counting, hence, rename it to
hci_conn_drop() so we can later fix ref-counting and introduce
hci_conn_put().

hci_conn_hold() and hci_conn_put() are currently used to manage how long a
connection should be held alive. When the last user drops the connection,
we spawn a delayed work that performs the disconnect. Obviously, this has
nothing to do with ref-counting for the _object_ but rather for the
keep-alive of the connection.

But we really _need_ proper ref-counting for the _object_ to allow
connection-users like rfcomm-tty, HIDP or others.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

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

This patch moves sending mgmt_connected from hci_acldata_packet() to
l2cap_connect_req() since this code is to handle the scenario remote
device sends l2cap connect req too fast
Signed-off-by: NJaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Remove code which cannot execute. l2cap_conn_add for AMP_LINK
might only be invoked when receiving data in l2cap_recv_acldata.
But this case is checked in the first statement there.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Make code more readable by changing CONF_NO_FCS_RECV which is read
as "No L2CAP FCS option received" to CONF_RECV_NO_FCS which means
"Received L2CAP option NO_FCS". This flag really means that we have
received L2CAP FRAME CHECK SEQUENCE (FCS) OPTION with value "No FCS".
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Process L2CAP Config rsp Pending with FCS Option 0x00 (No FCS)
which is sent by Motorola Windows 7 Bluetooth stack. The trace
is shown below (all other options are skipped).

...
< ACL data: handle 1 flags 0x00 dlen 48
    L2CAP(s): Config req: dcid 0x0043 flags 0x00 clen 36
      ...
      FCS Option 0x00 (No FCS)
> ACL data: handle 1 flags 0x02 dlen 48
    L2CAP(s): Config req: dcid 0x0041 flags 0x00 clen 36
      ...
      FCS Option 0x01 (CRC16 Check)
< ACL data: handle 1 flags 0x00 dlen 47
    L2CAP(s): Config rsp: scid 0x0043 flags 0x00 result 4 clen 33
      Pending
      ...
> ACL data: handle 1 flags 0x02 dlen 50
    L2CAP(s): Config rsp: scid 0x0041 flags 0x00 result 4 clen 36
      Pending
      ...
      FCS Option 0x00 (No FCS)
< ACL data: handle 1 flags 0x00 dlen 14
    L2CAP(s): Config rsp: scid 0x0043 flags 0x00 result 0 clen 0
      Success
> ACL data: handle 1 flags 0x02 dlen 14
    L2CAP(s): Config rsp: scid 0x0041 flags 0x00 result 0 clen 0
      Success
...
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

If L2CAP_FEAT_FCS is not supported we sould miss EWS option
configuration because of break. Make code more readable by
combining FCS configuration in the single block.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Before starting quering remote AMP controllers make sure
that there is local active AMP controller.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

l2cap_send_disconn_req takes 3 parameters of which conn might be
derived from chan. Make this conversion inside l2cap_send_disconn_req.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When receiving L2CAP Create Channel Request set the channel as
L2CAP_FCS_NONE. Then in "L2CAP Config req" following field will
be set: "FCS Option 0x00 (No FCS)". So by default High Speed
channels have no FCS.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Instead of printing:
"[ 7763.082007] Bluetooth: 2"
print something like:
"[ 7763.082007] Bluetooth: Trailing bytes: 2 in sframe"
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

When receiving Physical Link Completed event we need to create L2CAP
channel with L2CAP Create Chan Request. Current code was sending
this command only if connection was pending (which is probably
needed in channel move case). If channel is not moved but created
Create Chan should be sent for outgoing channel which is checked
with BT_CONNECT flag.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Set chan->fcs to L2CAP_FCS_NONE only for new L2CAP channels
(not moved). Other side can still request to use FCS.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Remove locking from l2cap_physical_cfm and lock chan inside
amp_physical_cfm.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

local_amp_id is already set in l2cap_connect() which is called several
lines above.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Use helper instead of test_bit. This is the only place left using
test CONF_CONNECT_PEND flag.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Since we have started to use local_amp_id for local AMP
Controller Id it makes sense to rename ctrl_id to remote_amp_id
since it represents remote AMP controller Id.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>