As preparation for moving SMP to use l2cap_chan infrastructure we need
to move the (de)initialization functions to smp.c (where they'll
eventually need access to the local L2CAP channel callbacks).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The code is consistently using the HCI_CONN_LE_SMP_PEND flag check for
the existence of the SMP context, with the exception of this one place
in smp_sig_channel(). This patch converts the place to use the flag just
like all other instances.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In the smp_cmd_sign_info() function the SMP_DIST_SIGN bit is explicitly
cleared early on in the function. This means that there's no need to
check for it again before calling smp_distribute_keys().
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The HCI_PAIRABLE flag isn't actually controlling whether we're pairable
but whether we're bondable. Therefore, rename it accordingly.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The HCI_CONN_LE_SMP_PEND flag is supposed to indicate whether we have an
SMP context or not. If the context creation fails, or some other error
is indicated between setting the flag and creating the context the flag
must be cleared first.

This patch ensures that smp_chan_create() clears the flag in case of
allocation failure as well as reorders code in smp_cmd_security_req()
that could lead to returning an error between setting the flag and
creating the context.

Without the patch the following kind of kernel crash could be observed
(this one because of unacceptable authentication requirements in a
Security Request):

[  +0.000855] kernel BUG at net/bluetooth/smp.c:606!
[  +0.000000] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[  +0.000000] CPU: 0 PID: 58 Comm: kworker/u5:2 Tainted: G        W     3.16.0-rc1+ #785
[  +0.008391] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  +0.000000] Workqueue: hci0 hci_rx_work
[  +0.000000] task: f4dc8f90 ti: f4ef0000 task.ti: f4ef0000
[  +0.000000] EIP: 0060:[<c13432b6>] EFLAGS: 00010246 CPU: 0
[  +0.000000] EIP is at smp_chan_destroy+0x1e/0x145
[  +0.000709] EAX: f46db870 EBX: 00000000 ECX: 00000000 EDX: 00000005
[  +0.000000] ESI: f46db870 EDI: f46db870 EBP: f4ef1dc0 ESP: f4ef1db0
[  +0.000000]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[  +0.000000] CR0: 8005003b CR2: b666b0b0 CR3: 00022000 CR4: 00000690
[  +0.000000] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[  +0.000000] DR6: fffe0ff0 DR7: 00000400
[  +0.000000] Stack:
[  +0.000000]  00000005 f17b7840 f46db870 f4ef1dd4 f4ef1de4 c1343441 c134342e 00000000
[  +0.000000]  c1343441 00000005 00000002 00000000 f17b7840 f4ef1e38 c134452a 00002aae
[  +0.000000]  01ef1e00 00002aae f46bd980 f46db870 00000039 ffffffff 00000007 f4ef1e34
[  +0.000000] Call Trace:
[  +0.000000]  [<c1343441>] smp_failure+0x64/0x6c
[  +0.000000]  [<c134342e>] ? smp_failure+0x51/0x6c
[  +0.000000]  [<c1343441>] ? smp_failure+0x64/0x6c
[  +0.000000]  [<c134452a>] smp_sig_channel+0xad6/0xafc
[  +0.000000]  [<c1053b61>] ? vprintk_emit+0x343/0x366
[  +0.000000]  [<c133f34e>] l2cap_recv_frame+0x1337/0x1ac4
[  +0.000000]  [<c133f34e>] ? l2cap_recv_frame+0x1337/0x1ac4
[  +0.000000]  [<c1172307>] ? __dynamic_pr_debug+0x3e/0x40
[  +0.000000]  [<c11702a1>] ? debug_smp_processor_id+0x12/0x14
[  +0.000000]  [<c1340bc9>] l2cap_recv_acldata+0xe8/0x239
[  +0.000000]  [<c1340bc9>] ? l2cap_recv_acldata+0xe8/0x239
[  +0.000000]  [<c1169931>] ? __const_udelay+0x1a/0x1c
[  +0.000000]  [<c131f120>] hci_rx_work+0x1a1/0x286
[  +0.000000]  [<c137244e>] ? mutex_unlock+0x8/0xa
[  +0.000000]  [<c131f120>] ? hci_rx_work+0x1a1/0x286
[  +0.000000]  [<c1038fe5>] process_one_work+0x128/0x1df
[  +0.000000]  [<c1038fe5>] ? process_one_work+0x128/0x1df
[  +0.000000]  [<c10392df>] worker_thread+0x222/0x2de
[  +0.000000]  [<c10390bd>] ? process_scheduled_works+0x21/0x21
[  +0.000000]  [<c103d34c>] kthread+0x82/0x87
[  +0.000000]  [<c1040000>] ? create_new_namespaces+0x90/0x105
[  +0.000000]  [<c13738e1>] ret_from_kernel_thread+0x21/0x30
[  +0.000000]  [<c103d2ca>] ? __kthread_parkme+0x50/0x50
[  +0.000000] Code: 65 f4 89 f0 5b 5e 5f 5d 8d 67 f8 5f c3 57 8d 7c 24 08 83 e4 f8 ff 77 fc 55 89 e5 57 89 c7 56 53 52 8b 98 e0 00 00 00 85 db 75 02 <0f> 0b 8b b3 80 00 00 00 8b 00 c1 ee 03 83 e6 01 89 f2 e8 ef 09
[  +0.000000] EIP: [<c13432b6>] smp_chan_destroy+0x1e/0x145 SS:ESP 0068:f4ef1db0
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Devices using resolvable private addresses are required to provide
an identity resolving key. These devices can not be found using
the current controller white list support. This means if the kernel
knows about any devices with an identity resolving key, the white
list filtering must be disabled.

However so far the kernel kept identity resolving keys around even
for devices that are not using resolvable private addresses. The
notification to userspace clearly hints to not store the key and
so it is best to just remove the key from the kernel as well at
that point.

With this it easy now to detect when using the white list is
possible or when kernel side resolving of addresses is required.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The EOPNOTSUPP and ENOTSUPP errors are very similar in meaning, but
ENOTSUPP is a fairly new addition to POSIX. Not all libc versions know
about the value the kernel uses for ENOTSUPP so it's better to use
EOPNOTSUPP to ensure understandable error messages.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If user space has a NoInputNoOutput IO capability it makes no sense to
bother it with confirmation requests. This patch updates both SSP and
SMP to check for the local IO capability before sending a user
confirmation request to user space.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

To make the code more understandable it makes sense to use the new HCI
defines for connection role instead of a "bool master" parameter. This
makes it immediately clear when looking at the function calls what the
last parameter is describing.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Having a dedicated u8 role variable in the hci_conn struct greatly
simplifies tracking of the role, since this is the native way that it's
represented on the HCI level.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In the case that the key distribution bits cause us not to generate a
local LTK we should not try to re-encrypt if we're currently encrypted
with an STK. This patch fixes the check for this in the
smp_sufficient_security function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If the remote device tries to initiate bonding with us and we don't have
HCI_PAIRABLE set we should just flat out reject the request. This brings
SMP in line with how the flag is used for BR/EDR SSP.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When the SMP context is created all flags default to zero. To determine
that we are the initiators it's therefore best to simply change the flag
value when we know we're sending the first SMP PDU. Clearing the flag
when receiving a Pairing Request is not correct since the request may be
a response to a previous Security Request from us (for which we would
already have correctly set the flag). Same goes for receiving a Security
Request which may be coming after us already starting pairing by sending
a Pairing Request.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Whether we bond or not should not have any impact on the user
interaction model. This patch removes an incorrect fall-back from
JUST_CFM to JUST_WORKS in case we're not bonding.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

For incoming requests we want to let the user know that pairing is
happening since otherwise there could be access to MEDIUM security
services without any user interaction at all. Therefore, set the
selected method to JUST_CFM instead of JUST_WORKS and let it be
converted back to JUST_WORKS later if we are the initators.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If we're encrypted with the STK we should allow re-encryption with an
LTK even though the achieved security level is the same. This patch adds
the necessary logic to the smp_sufficient_security function which is
used to determine whether to proceed with encryption or not.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There are certain subtle differences in behavior when we're encrypted
with the STK, such as allowing re-encryption even though the security
level stays the same. Because of this, add a flag to track whether we're
encrypted with an STK or not.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If we're already encrypted with a good enough LTK we should just ignore
an incoming SMP Security Request. The code was already taking care of
this in the smp_conn_security function before calling smp_ltk_encrypt
but failed to do the same in smp_cmd_security_req. This patch fixes the
issue by moving up the smp_sufficient_security function and using it in
the Security Request handler before trying to request encryption.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The return value of smp_ltk_encrypt is simple boolean, so just use
bool and make the code a bit more readable.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

The smp_conn member of struct hci_conn was simply a pointer to the
l2cap_conn object. Since we already have hcon->l2cap_data that points to
the same thing there's no need to have this second variable. This patch
removes it and changes the single place that was using it to use
hcon->l2cap_data instead.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The smp_user_confirm_reply() function is called whenever user space
sends a user confirmation reply mgmt command. In case of a misbehaving
user space, or if the SMP session was removed by the time the command
comes it is important that we return an appropriate error and do not try
to access the non-existent SMP context. This patch adds the appropriate
check for the HCI_CONN_LE_SMP_PEND flag before proceeding further.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Passing the full SMP context instead of just the crypto context lets us
use the crypto handle from the context which in turn removes the need to
lock the hci_dev. Passing the SMP context instead of just the crypto
handle allows a bit more detailed logging which is helpful in
multi-adapter scenarios.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Many places have to be extra careful to not hold the hdev lock when
calling into the SMP code. This is because the SMP crypto functions use
the crypto handle that's part of the hci_dev struct. Giving the SMP
context its own handle helps simplifying the locking logic and removes
the risk for deadlocks.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The hdev lock must be held before calling into smp_distribute_keys. Also
things such as hci_add_irk() require the lock. This patch fixes the
issue by adding the necessary locking into the smp_cmd_ident_addr_info
function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Since the link_mode member of the hci_conn struct is a bit field and we
already have a flags member as well it makes sense to merge these two
together. This patch moves all used link_mode bits into corresponding
flags. To keep backwards compatibility with user space we still need to
provide a get_link_mode() helper function for the ioctl's that expect a
link_mode style value.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Since the SMP code needs to swap ordering of variable length buffers add
a convenience function that can be used for any length buffer.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There's no reason to have explicit values for these flags. Convert them
to an enum to be consistent with other similar flags.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The LTK type has really nothing to do with HCI so it makes more sense to
have these in smp.h than hci.h. This patch moves the defines to smp.h
and removes the HCI_ prefix in the same go.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We never store the "master" type of STKs since we request encryption
directly with them so we only need one STK type (the one that's
looked-up on the slave side). Simply remove the unnecessary define and
rename the _SLAVE one to the shorter form.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The smp_chan_create function may return NULL, e.g. in the case of memory
allocation failure, so we always need to check for this.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If we need an MITM protected connection but the local and remote IO
capabilities cannot provide it we should reject the pairing attempt in
the appropriate way. This patch adds the missing checks for such a
situation to the smp_cmd_pairing_req() and smp_cmd_pairing_rsp()
functions.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We'll need to do authentication method lookups from more than one place,
so refactor the lookup into its own function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When we receive a pairing request or an internal request to start
pairing we shouldn't blindly overwrite the existing pending_sec_level
value as that may actually be higher than the new one. This patch fixes
the SMP code to only overwrite the value in case the new one is higher
than the old.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When we store the STK in slave role we should set the correct
authentication information for it. If the pairing is producing a HIGH
security level the STK is considered authenticated, and otherwise it's
considered unauthenticated. This patch fixes the value passed to the
hci_add_ltk() function when adding the STK on the slave side.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Tested-by: NMarcin Kraglak <marcin.kraglak@tieto.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

Due to recent changes to the way that the MITM requirement is set for
outgoing pairing attempts we can no longer rely on the hcon->auth_type
variable (which is actually good since it was formed from BR/EDR
concepts that don't really exist for SMP).

To match the logic that BR/EDR now uses simply rely on the local IO
capability and/or needed security level to set the MITM requirement for
outgoing pairing requests.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

Now that smp_confirm() is called "inline" we can have it return a
response code and have the sending of it be done in the shared place for
command handlers. One exception is when we're entering smp.c from mgmt.c
when user space responds to authentication, in which case we still need
our own code to call smp_failure().
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Since we're now calling smp_random() "inline" we can have it directly
return a response code and have the shared command handler send the
response.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There's no reason to have "smp" in this variable name since it is
already part of the SMP struct which provides sufficient context.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When the SMP code was initially created (mid-2011) parts of the
Bluetooth subsystem were still not converted to use workqueues. This
meant that the crypto calls, which could sleep, couldn't be called
directly. Because of this the "confirm" and "random" work structs were
introduced.

These days the entire Bluetooth subsystem runs through workqueues which
makes these structs unnecessary. This patch removes them and converts
the calls to queue them to use direct function calls instead.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There is no reason to have the initial local value conditional to
whether the remote value has bonding set or not. We can either way start
off with the value we received.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>