During an audit for sk_filter(), we found that rx_busy_skb handling
in l2cap_sock_recv_cb() and l2cap_sock_recvmsg() looks not quite as
intended.
The assumption from commit e328140fda ("Bluetooth: Use event-driven
approach for handling ERTM receive buffer") is that errors returned
from sock_queue_rcv_skb() are due to receive buffer shortage. However,
nothing should prevent doing a setsockopt() with SO_ATTACH_FILTER on
the socket, that could drop some of the incoming skbs when handled in
sock_queue_rcv_skb().
In that case sock_queue_rcv_skb() will return with -EPERM, propagated
from sk_filter() and if in L2CAP_MODE_ERTM mode, wrong assumption was
that we failed due to receive buffer being full. From that point onwards,
due to the to-be-dropped skb being held in rx_busy_skb, we cannot make
any forward progress as rx_busy_skb is never cleared from l2cap_sock_recvmsg(),
due to the filter drop verdict over and over coming from sk_filter().
Meanwhile, in l2cap_sock_recv_cb() all new incoming skbs are being
dropped due to rx_busy_skb being occupied.
Instead, just use __sock_queue_rcv_skb() where an error really tells that
there's a receive buffer issue. Split the sk_filter() and enable it for
non-segmented modes at queuing time since at this point in time the skb has
already been through the ERTM state machine and it has been acked, so dropping
is not allowed. Instead, for ERTM and streaming mode, call sk_filter() in
l2cap_data_rcv() so the packet can be dropped before the state machine sees it.
Fixes: e328140fda ("Bluetooth: Use event-driven approach for handling ERTM receive buffer")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The HCI_BREDR naming is confusing since it actually stands for Primary
Bluetooth Controller. Which is a term that has been used in the latest
standard. However from a legacy point of view there only really have
been Basic Rate (BR) and Enhanced Data Rate (EDR). Recent versions of
Bluetooth introduced Low Energy (LE) and made this terminology a little
bit confused since Dual Mode Controllers include BR/EDR and LE. To
simplify this the name HCI_PRIMARY stands for the Primary Controller
which can be a single mode or dual mode controller.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The LE dynamic PSM range is different from BR/EDR (0x0080 - 0x00ff)
and doesn't have requirements relating to parity, so separate checks
are needed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Remove unneeded variable used to store return value.
Error reported by coccicheck.
Signed-off-by: Prasanna Karthik <mkarthi3@visteon.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The hci_connect_le_scan() is (as the name implies) a master/central
role API, so it makes no sense in passing a role parameter to it. At
the same time this patch also fixes the direct advertising support for
LE L2CAP sockets where we now call the more appropriate hci_le_connect()
API if slave/peripheral role is desired.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When receiving a connect response we should make sure that the DCID is
within the valid range and that we don't already have another channel
allocated for the same DCID.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The 'dyn_end' value is also a valid CID so it should be included in
the range of values checked.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The core spec defines specific response codes for situations when the
received CID is incorrect. Add the defines for these and return them
as appropriate from the LE Connect Request handler function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Currently, when trying to connect to already paired device that just
rotated its RPA MAC address, old address would be used and connection
would fail. In order to fix that, kernel must scan and receive
advertisement with fresh RPA before connecting.
This patch enables new connection establishment procedure. Instead of just
sending HCI_OP_LE_CREATE_CONN to controller, "connect" will add device to
kernel whitelist and start scan. If advertisement is received, it'll be
compared against whitelist and then trigger connection if it matches.
That fixes mentioned reconnect issue for already paired devices. It also
make whole connection procedure more robust. We can try to connect to
multiple devices at same time now, even though controller allow only one.
Signed-off-by: Jakub Pawlowski <jpawlowski@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If the user->list is deleted with list_del(), it doesn't initialize the
entry which can cause the issue with list_empty(). According to the
comment from the list.h, list_empty() returns false even if the list is
empty and put the entry in an undefined state.
/**
* list_del - deletes entry from list.
* @entry: the element to delete from the list.
* Note: list_empty() on entry does not return true after this, the entry is
* in an undefined state.
*/
Because of this behavior, list_empty() returns false even if list is empty
when the device is reconnected.
So, user->list needs to be re-initialized after list_del(). list.h already
have a macro list_del_init() which deletes the entry and initailze it again.
Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
list_del() poisons pointers with special values, no need to overwrite them.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The return value of l2cap_recv_acldata() and sco_recv_scodata()
are not used, then change it to return void
Signed-off-by: Arron Wang <arron.wang@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We're getting very close to the maximum possible size of bt_skb_cb. To
prepare to shrink the struct with the help of a union this patch moves
all L2CAP related variables into the l2cap_ctrl struct. To later add
other 'ctrl' structs the L2CAP one is renamed simple 'l2cap' instead
of 'control'.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
With the extension of hdev->dev_flags utilizing a bitmap now, the space
is no longer restricted. Merge the hdev->dbg_flags into hdev->dev_flags
to save space on 64-bit architectures. On 32-bit architectures no size
reduction happens.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Instead of manually coding test_bit on hdev->dev_flags all the time,
use hci_dev_test_flag helper macro.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This patch moves all the disconn_cfm callbacks to be based on the hci_cb
list. This means making l2cap_disconn_cfm private to l2cap_core.c and
sco_conn_cb private to sco.c respectively. Since the hci_conn type
filtering isn't done any more on the wrapper level the callbacks
themselves need to check that they were passed a relevant type of
connection.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch moves all the connect_cfm callbacks to be based on the hci_cb
list. This means making l2cap_connect_cfm private to l2cap_core.c and
sco_connect_cb private to sco.c respectively. Since the hci_conn type
filtering isn't done any more on the wrapper level the callbacks
themselves need to check that they were passed a relevant type of
connection.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no reason to have the custom hci_proto_auth/encrypt_cfm helpers
when the hci_cb list works equally well. This patch adds L2CAP to the
hci_cb list and makes l2cap_security_cfm a private function of
l2cap_core.c.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
On BR/EDR the L2CAP channel instances for fixed channels have so far
been marked as ready only once the L2CAP information req/rsp procedure
is complete and we have the fixed channel mask. This could however lead
to data being dropped if we receive it on the channel before knowing the
remote mask.
Since it is valid for a remote to send data this early, simply assume
that the channel is supported when we receive data on it. So far this
hasn't been noticed much because of limited use of fixed channels on
BR/EDR, but e.g. with SMP over BR/EDR this is already now visible with
automated tests failing randomly.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The comparing of chan->src should always be done against the local
identity address, represented by hcon->src and hcon->src_type. This
patch modifies l2cap_global_fixed_chan() to take the full hci_conn so
that we can easily compare against hcon->src and hcon->src_type.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The current bdaddr_type() usage in l2cap_core.c is a bit funny in that
it's always passed a hci_conn + a hci_conn member. Because of this only
the hci_conn is really needed. Since the second parameter is always
either hcon->src_type or hcon->dst type this patch adds two helper
functions for each purpose: bdaddr_src_type() and bdaddr_dst_type().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The devices address types are BR/EDR Public, LE Public and LE Random and
any of these three is valid for L2CAP connections. So show the correct
type in the debugfs list.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Testing cross-transport pairing that starts on BR/EDR is only valid when
using a controller with BR/EDR Secure Connections. Devices will indicate
this by providing BR/EDR SMP fixed channel over L2CAP. To allow testing
of this feature on Bluetooth 4.0 controller or controllers without the
BR/EDR Secure Connections features, introduce a force_bredr_smp debugfs
option that allows faking the required AES connection.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Just use copy_from_iter(). That's what this method is trying to do
in all cases, in a very convoluted fashion.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
it'll die soon enough - now that kvec-backed iov_iter works regardless
of set_fs(), both instances will become copy_from_iter() as soon as
we introduce ->msg_iter...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The SMP over BR/EDR support for cross-transport pairing should also be
enabled when the debugfs setting force_lesc_support has been enabled.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
When doing SMP over BR/EDR some of the routines can be shared with the
LE functionality whereas others needs to be split into their own BR/EDR
specific branches. This patch implements the split of BR/EDR specific
SMP code from the LE-only code, making sure SMP over BR/EDR works as
specified.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To pave the way for future fixed channels to be added easily we should
track both the local and remote mask on a per-L2CAP connection (struct
l2cap_conn) basis. So far the code has used a global variable in a racy
way which anyway needs fixing.
This patch renames the existing conn->fixed_chan_mask that tracked
the remote mask to conn->remote_fixed_chan and adds a new variable
conn->local_fixed_chan to track the local mask. Since the HS support
info is now available in the local mask we can remove the
conn->hs_enabled variable.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The Bluetooth spec states that automatically flushable packets may not
be sent over a LE-U link.
Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This patch adds some extra debug logs to L2CAP related code. These are
mainly to help track locking issues but will probably be useful for
debugging other types of issues as well.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The insufficient authentication/encryption errors indicate to the L2CAP
client that it should try to elevate the security level. Since there
really isn't any exception to this rule it makes sense to fully handle
it on the kernel side instead of pushing the responsibility to user
space.
This patch adds special handling of these two error codes and calls
smp_conn_security() with the elevated security level if necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
So far smp_sufficient_security() has returned false if we're encrypted
with an STK but do have an LTK available. However, for the sake of LE
CoC servers we do want to let the incoming connection through even
though we're only encrypted with the STK.
This patch adds a key preference parameter to smp_sufficient_security()
with two possible values (enum used instead of bool for readability).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For LE CoC L2CAP servers we don't do security level elevation during the
BT_CONNECT2 state (instead LE CoC simply sends an immediate error
response if the security level isn't high enough). Therefore if we get a
security level change while an LE CoC channel is in the BT_CONNECT2
state we should simply do nothing.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no reason why all users of L2CAP would need to worry about
initializing chan->nesting to L2CAP_NESTING_NORMAL (which is important
since 0 is the same as NESTING_SMP). This patch moves the initialization
to the common place that's used to create all new channels, i.e. the
l2cap_chan_create() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the error case where credits is greater than max_credits there
is a missing l2cap_chan_unlock before returning.
Signed-off-by: Martin Townsend <mtownsend1973@gmail.com>
Tested-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The values of a lot of the mgmt_device_connected() parameters come
straight from a hci_conn object. We can simplify the function by passing
the full hci_conn pointer to it.
Signed-off-by: Alfonso Acosta <fons@spotify.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The L2CAP connection's channel list lock (conn->chan_lock) must never be
taken while already holding a channel lock (chan->lock) in order to
avoid lock-inversion and lockdep warnings. So far the l2cap_chan_connect
function has acquired the chan->lock early in the function and then
later called l2cap_chan_add(conn, chan) which will try to take the
conn->chan_lock. This violates the correct order of taking the locks and
may lead to the following type of lockdep warnings:
-> #1 (&conn->chan_lock){+.+...}:
[<c109324d>] lock_acquire+0x9d/0x140
[<c188459c>] mutex_lock_nested+0x6c/0x420
[<d0aab48e>] l2cap_chan_add+0x1e/0x40 [bluetooth]
[<d0aac618>] l2cap_chan_connect+0x348/0x8f0 [bluetooth]
[<d0cc9a91>] lowpan_control_write+0x221/0x2d0 [bluetooth_6lowpan]
-> #0 (&chan->lock){+.+.+.}:
[<c10928d8>] __lock_acquire+0x1a18/0x1d20
[<c109324d>] lock_acquire+0x9d/0x140
[<c188459c>] mutex_lock_nested+0x6c/0x420
[<d0ab05fd>] l2cap_connect_cfm+0x1dd/0x3f0 [bluetooth]
[<d0a909c4>] hci_le_meta_evt+0x11a4/0x1260 [bluetooth]
[<d0a910eb>] hci_event_packet+0x3ab/0x3120 [bluetooth]
[<d0a7cb08>] hci_rx_work+0x208/0x4a0 [bluetooth]
CPU0 CPU1
---- ----
lock(&conn->chan_lock);
lock(&chan->lock);
lock(&conn->chan_lock);
lock(&chan->lock);
Before calling l2cap_chan_add() the channel is not part of the
conn->chan_l list, and can therefore only be accessed by the L2CAP user
(such as l2cap_sock.c). We can therefore assume that it is the
responsibility of the user to handle mutual exclusion until this point
(which we can see is already true in l2cap_sock.c by it in many places
touching chan members without holding chan->lock).
Since the hci_conn and by exctension l2cap_conn creation in the
l2cap_chan_connect() function depend on chan details we cannot simply
add a mutex_lock(&conn->chan_lock) in the beginning of the function
(since the conn object doesn't yet exist there). What we can do however
is move the chan->lock taking later into the function where we already
have the conn object and can that way take conn->chan_lock first.
This patch implements the above strategy and does some other necessary
changes such as using __l2cap_chan_add() which assumes conn->chan_lock
is held, as well as adding a second needed label so the unlocking
happens as it should.
Reported-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Tested-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Even if we have no connection-oriented channels we should perform the
L2CAP Information Request procedures before notifying L2CAP channels of
the connection. This is so that the L2CAP channel implementations can
perform checks on what the remote side supports (e.g. does it support
the fixed channel in question).
So far the code has relied on the l2cap_do_start() function to initiate
the Information Request, however l2cap_do_start() is used on a
per-channel basis and only for connection-oriented channels. This means
that if there are no connection-oriented channels on the system we would
never start the Information Request procedure.
This patch creates a new l2cap_request_info() helper function to
initiate the Information Request procedure, and ensures that it is
called whenever a BR/EDR connection has been established. The patch also
updates fixed channels to be notified of connection readiness only once
the Information Request procedure has completed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The identity address update of all channels for an l2cap_conn needs to
take the lock for each channel, i.e. it's safest to do this by a
separate workqueue callback.
Previously this was partially solved by moving the entire SMP key
distribution behind a workqueue. However, if we want SMP context locking
to be correct and safe we should always use the l2cap_chan lock when
accessing it, meaning even smp_distribute_keys needs to take that lock
which would once again create a dead lock when updating the identity
address.
The simplest way to solve this is to have l2cap_conn manage the deferred
work which is what this patch does. A subsequent patch will remove the
now unnecessary SMP key distribution work struct.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The "pending" L2CAP response value is not defined for LE CoC. This patch
adds a clarifying comment to the code so that the reader will not think
there is a bug in trying to use this value for LE CoC.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that there are no more users of the l2cap_conn_shutdown API (since
smp.c switched to using hci_disconnect) we can simply remove it along
with all of it's l2cap_conn variables.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the l2cap_conn_del() function is used we do not want to wait around
"in case something happens" before disconnecting. This patch sets the
disconnection timeout to 0 so that the disconnection routines get
immediately scheduled.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
It's natural to have *_get() functions that increment the reference
count of an object to return the object type itself. This way it's
simple to make a copy of the object pointer and increase the reference
count in a single step. This patch updates two such get() functions,
namely hci_conn_get() and l2cap_conn_get(), and updates the users to
take advantage of the new API.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that SMP has been converted to use fixed channels we've got a bit of
a problem with the hci_conn reference counting. So far the L2CAP code
has kept a reference for each L2CAP channel that was notified of the
connection. With SMP however this would mean that the connection is
never dropped even though there are no other users of it. Furthermore,
SMP already does its own hci_conn reference counting internally,
starting from a security or pairing request and ending with the key
distribution.
This patch makes L2CAP fixed channels default to the L2CAP core not
keeping a hci_conn reference for them. A new FLAG_HOLD_HCI_CONN flag is
added so that L2CAP users can declare an exception to this rule and hold
a reference even for their fixed channels. One such exception is the
L2CAP socket layer which does want a reference for each socket (e.g. an
ATT socket which uses a fixed channel).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The l2cap_chan_add() function doesn't require the channel to be
unlocked. It only requires the l2cap_conn to be unlocked. Therefore,
it's unnecessary to unlock a channel before calling l2cap_chan_add().
This patch removes such unnecessary unlocking from the
l2cap_chan_connect() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The l2cap_create_le_flowctl_pdu() function that l2cap_segment_le_sdu()
calls is perfectly capable of doing packet fragmentation if given bigger
PDUs than the HCI buffers allow. Forcing the PDU length based on the HCI
MTU (conn->mtu) would therefore needlessly strict operation on hardware
with limited LE buffers (e.g. both Intel and Broadcom seem to have this
set to just 27 bytes).
This patch removes the restriction and makes it possible to send PDUs of
the full length that the remote MPS value allows.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
I-Frame which is going to be resend already has FCS field added and set
(if it was required). Adding additional FCS field calculated from data +
old FCS in resend function is incorrect. This patch fix that.
Issue has been found during PTS testing.
Signed-off-by: Lukasz Rymanowski <lukasz.rymanowski@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
