The range of valid LE PSMs is 0x0001-0x00ff so the check should be for
"less than or equal to" instead of "less than".
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Since there's a nice convenient helper for calculating the minimum of
two values, let's use that one.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The values in l2cap_chan that are used for actually transmitting data
only need to be initialized right after we've received an L2CAP Connect
Request or just before we send one. The only thing that we need to
initialize though bind() and connect() is the chan->mode value. This way
all other initializations can be done in the l2cap_le_flowctl_init
function (which now becomes private to l2cap_core.c) and the
l2cap_le_flowctl_start function can be completely removed.

Also, since the l2cap_sock_init function initializes the imtu and omtu
to adequate values these do not need to be part of l2cap_le_flowctl_init.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds entries to debugfs to control the values used for the
MPS and Credits for LE Flow Control Mode.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

LE PSM values have different ranges than those for BR/EDR. The valid
ranges for fixed, SIG assigned values is 0x0001-0x007f and for dynamic
PSM values 0x0080-0x00ff. We need to ensure that bind() and connect()
calls conform to these ranges when operating on LE CoC sockets.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

LE CoC used differend CIC ranges than BR/EDR L2CAP. The start of the
range is the same (0x0040) but the range ends at 0x007f (unlike BR/EDR
where it goes all the way to 0xffff).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The outgoing MTU should only be set upon channel creation to the initial
minimum value (23) or from a remote connect req/rsp PDU.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

It doesn't make sense to have an MPS value greater than the configured
MTU value since we will then not be able to fill up the packets to their
full possible size. We need to set the MPS both in flowctl_init()
as well as flowctl_start() since the imtu may change after init() but
start() is only called after we've sent the LE Connection Request PDU
which depends on having a valid MPS value.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If the peer gives us zero credits in its connection request or response
we must call the suspend channel callback so the BT_SK_SUSPEND flag gets
set and user space is blocked from sending data to the socket.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Unlike BR/EDR, for LE when we're in the BT_CONNECT state we may or may
not have already have sent the Connect Request. This means that we need
some extra tracking of the request. This patch adds an extra channel
flag to prevent the request from being sent a second time.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When receiving fragments over an LE Connection oriented Channel they
need to be collected up and eventually merged into a single SDU. This
patch adds the necessary code for collecting up the fragment skbs to the
channel context and passing them to the recv() callback when the entire
SDU has been received.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds segmentation support for outgoing data packets. Packets
are segmented based on the MTU and MPS values. The l2cap_chan struct
already contains many helpful variables from BR/EDR Enhanced L2CAP which
can be used for this.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Since LE CoC support needs to be enabled through a module option for now
we need to reject any related signaling PDUs in addition to rejecting
the creation of LE CoC sockets (which we already do).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds the necessary discipline for reacting to LE L2CAP
Credits packets, sending those packets, and modifying the known credits
accordingly.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We should return credits to the remote side whenever they fall below a
certain level (in our case under half of the initially given amount).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds tracking of L2CAP connection oriented channel local and
remote credits to struct l2cap_chan and ensures that connect requests
and responses contain the right values.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The LE connection oriented channels have their own mode with its own
data transfer rules. In order to implement this properly we need to
distinguish L2CAP channels operating in this mode from other modes.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch makes the error handling and return logic of l2cap_le_sig_cmd
consistent with its BR/EDR counterpart.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The normal L2CAP Disconnect request and response are also used for LE
connection oriented channels. Therefore, we can simply use the existing
handler functions for terminating LE based L2CAP channels.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Sending of the L2CAP Disconnect request should also be performed for LE
based channels. The proper thing to do is therefore to look at whether
there's a PSM specified for the channel instead of looking at the link
type.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds the necessary boiler plate code to handle receiving
L2CAP connect requests over LE and respond to them with a proper connect
response.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We'll need to have a separate code path for LE based connection
rejection so it's cleaner to move out the response construction code
into its own function (and later a second one for LE).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds the necessary code to send an LE L2CAP Connect Request
and handle its response when user space has provided us with an LE
socket with a PSM instead of a fixed CID.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Once connection oriented L2CAP channels over LE are supported they will
need a completely separate handling from BR/EDR channels.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The LE signaling PDU length is already calculated in the
l2cap_le_sig_channel function so we can just pass the value to the
various handler functions to avoid unnecessary recalculations (byte
order conversions). Right now the only user is the connection parameter
update procedure, but as new LE signaling operations become available
(for connection oriented channels) they will also be able to make use of
the value.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

With connection oriented L2CAP channels some code paths will be shared
with BR/EDR links. It is therefore necessary to allow the
l2cap_chan_check_security function to be usable also for LE links in
addition to BR/EDR ones. This means that smp_conn_security() needs to be
called instead of hci_conn_security() in the case of an LE link.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Once connection oriented L2CAP channels become possible for LE we need
to be able to specify the link type we're interested in when looking up
L2CAP channels. Therefore, add a link_type parameter to the
l2cap_global_chan_by_psm() function which gets compared to the address
type associated with each l2cap_chan.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch is just a trivial coding style fix to remove unnecessary
braces from a one-line if-statement.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

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>

Instead of accessing skb->sk in L2CAP core we now compare the channel
a skb belongs to and not send it back if the channel is same. This change
removes another struct socket usage from L2CAP core.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The parent socket is not used inside the L2CAP core anymore. We only lock
it to indirect access through the new_connection() callback. The hold of
the socket lock was moved to the new_connection() callback.

Inside L2CAP core the channel lock is now used in l2cap_le_conn_ready()
and l2cap_conn_ready() to protect the execution of these two functions
during the handling of new incoming connections.

This change remove the socket lock usage from L2CAP core while keeping
the code safe against race conditions.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This simplify and make safer the state change handling inside l2cap_core.c.
we got rid of __l2cap_state_change(). And l2cap_state_change() doesn't lock
the socket anymore, instead the socket is locked inside the ops callback for
state change in l2cap_sock.c.

It makes the code safer because in some we were using a unlocked version,
and now we are calls to l2cap_state_change(), when dealing with sockets, use
the locked version.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In both places that we use the defer callback the socket lock is held for
a indirect sk access inside __l2cap_change_state() and chan->ops->defer(),
all the rest of the code between lock_sock() and release_sock() is
already protected by the channel lock and won't be affected by this
change.

We now use l2cap_change_state(), the locked version of the change state
function, and the defer callback does the locking itself now. This does
not affect other uses of the defer callback.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

It is a leftover from the recent effort of remove sk usage from L2CAP
core.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When the remote LE device is blocked, then do not create a L2CAP
channel for it. Without a channel, all packets for that connection
will be dropped.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

When the HCI connection hcon is already dereferenced, then use hcon
directly instead of conn->hcon.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Make sure to use IS_ERR_OR_NULL for checking the existing of the root
debugfs dentry bt_debugfs.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Now that the only reason code this function can return is
L2CAP_REJ_NOT_UNDERSTOOD we can just do the necessary assignment without
needing a separate function at all.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There is no command handler that would return an EMSGSIZE error, so just
remove this mapping from the l2cap_err_to_reason function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When the reason code in the L2CAP command reject is "invalid CID" there
should be four additional bytes of data in the PDU, namely the source
and destination CIDs (which should be zero if one or both are not
applicable). This patch fixes all occurrences of such errors to return
the right kind of PDU.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>