Modification of Nick Pelly <npelly@google.com> patch.

With Bluetooth 2.1 ACL packets can be flushable or non-flushable. This commit
makes ACL data packets non-flushable by default on compatible chipsets, and
adds the BT_FLUSHABLE socket option to explicitly request flushable ACL
data packets for a given L2CAP socket. This is useful for A2DP data which can
be safely discarded if it can not be delivered within a short time (while
other ACL data should not be discarded).

Note that making ACL data flushable has no effect unless the automatic flush
timeout for that ACL link is changed from its default of 0 (infinite).

Default packet types (for compatible chipsets):
Frame 34: 13 bytes on wire (104 bits), 13 bytes captured (104 bits)
Bluetooth HCI H4
Bluetooth HCI ACL Packet
    .... 0000 0000 0010 = Connection Handle: 0x0002
    ..00 .... .... .... = PB Flag: First Non-automatically Flushable Packet (0)
    00.. .... .... .... = BC Flag: Point-To-Point (0)
    Data Total Length: 8
Bluetooth L2CAP Packet

After setting BT_FLUSHABLE
(sock.setsockopt(274 /*SOL_BLUETOOTH*/, 8 /* BT_FLUSHABLE */, 1 /* flush */))
Frame 34: 13 bytes on wire (104 bits), 13 bytes captured (104 bits)
Bluetooth HCI H4
Bluetooth HCI ACL Packet
    .... 0000 0000 0010 = Connection Handle: 0x0002
    ..10 .... .... .... = PB Flag: First Automatically Flushable Packet (2)
    00.. .... .... .... = BC Flag: Point-To-Point (0)
    Data Total Length: 8
Bluetooth L2CAP Packet
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

This patch fixes a minor issue that two connection responses will be sent
for one L2CAP connection request. If the L2CAP connection request is first
blocked due to security reason and responded with reason "security block",
the state of the connection remains BT_CONNECT2. If a pairing procedure
completes successfully before the ACL connection is down, local host will
send another connection complete response. See the following packets
captured by hcidump.

2010-12-07 22:21:24.928096 < ACL data: handle 12 flags 0x00 dlen 16
    0000: 0c 00 01 00 03 19 08 00  41 00 53 00 03 00 00 00  ........A.S.....
... ...

2010-12-07 22:21:35.791747 > HCI Event: Auth Complete (0x06) plen 3
    status 0x00 handle 12
... ...

2010-12-07 22:21:35.872372 > ACL data: handle 12 flags 0x02 dlen 16
    L2CAP(s): Connect rsp: dcid 0x0054 scid 0x0040 result 0 status 0
      Connection successful
Signed-off-by: NLiang Bao <tim.bao@gmail.com>
Acked-by: NVille Tervo <ville.tervo@nokia.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

When there is an existing connection l2cap_check_security needs to be
called to ensure that the security level of the new socket is fulfilled.
Normally l2cap_do_start takes care of this, but that function doesn't
get called for SOCK_RAW type sockets. This patch adds the necessary
l2cap_check_security call to the appropriate branch in l2cap_do_connect.
Signed-off-by: NJohan Hedberg <johan.hedberg@nokia.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

The logic for determining the needed auth_type for an L2CAP socket is
rather complicated and has so far been duplicated in
l2cap_check_security as well as l2cap_do_connect. Additionally the
l2cap_check_security code was completely missing the handling of
SOCK_RAW type sockets. This patch creates a unified function for the
evaluation and makes l2cap_do_connect and l2cap_check_security use that
function.
Signed-off-by: NJohan Hedberg <johan.hedberg@nokia.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

CC: Marcel Holtmann <marcel@holtmann.org>
CC: "Gustavo F. Padovan" <padovan@profusion.mobi>
CC: João Paulo Rechi Vita <jprvita@profusion.mobi>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

If such event happens we shall reply with a Command Reject, because we are
not expecting any configure request.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Do not initialize static vars to zero, macros with complex values
shall be enclosed with (), remove unneeded braces.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

create_singlethread_workqueue() may fail with errors such as -ENOMEM. If
this happens, the return value is not set to a negative value and the
module load will succeed. It will then crash on module unload because of
a destroy_workqueue() call on a NULL pointer.

Additionally, the _busy_wq workqueue is not being destroyed if any
errors happen on l2cap_init().
Signed-off-by: NAnderson Lizardo <anderson.lizardo@openbossa.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

l2cap_get_sock_by_psm() was the only user of this function, so I merged
both into l2cap_get_sock_by_psm(). The socket lock now should be hold
outside of l2cap_get_sock_by_psm() once we hold and release it inside the
same function now.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

In timer context we might delete l2cap channel used by krfcommd.
The check makes sure that sk is not owned. If sk is owned we
restart timer for HZ/5.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Check that socket sk is not locked in user process before removing
l2cap connection handler.

lock_sock and release_sock do not hold a normal spinlock directly but
instead hold the owner field. This means bh_lock_sock can still execute
even if the socket is "locked". More info can be found here:
http://www.linuxfoundation.org/collaborate/workgroups/networking/socketlocks

krfcommd kernel thread may be preempted with l2cap tasklet which remove
l2cap_conn structure. If krfcommd is in process of sending of RFCOMM reply
(like "RFCOMM UA" reply to "RFCOMM DISC") then kernel crash happens.

...
[  694.175933] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[  694.184936] pgd = c0004000
[  694.187683] [00000000] *pgd=00000000
[  694.191711] Internal error: Oops: 5 [#1] PREEMPT
[  694.196350] last sysfs file: /sys/devices/platform/hci_h4p/firmware/hci_h4p/loading
[  694.260375] CPU: 0    Not tainted  (2.6.32.10 #1)
[  694.265106] PC is at l2cap_sock_sendmsg+0x43c/0x73c [l2cap]
[  694.270721] LR is at 0xd7017303
...
[  694.525085] Backtrace:
[  694.527587] [<bf266be0>] (l2cap_sock_sendmsg+0x0/0x73c [l2cap]) from [<c02f2cc8>] (sock_sendmsg+0xb8/0xd8)
[  694.537292] [<c02f2c10>] (sock_sendmsg+0x0/0xd8) from [<c02f3044>] (kernel_sendmsg+0x48/0x80)
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Last commit added a wrong endianness conversion. Fixing that.
Reported-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

In function l2cap_get_conf_opt() and l2cap_add_conf_opt() the address of
opt->val sometimes is not at the edge of 2-bytes/4-bytes, so 2-bytes/4 bytes
access will cause data misalignment exeception.  Use get_unaligned_le16/32
and put_unaligned_le16/32 function to avoid data misalignment execption.
Signed-off-by: Nsteven miao <realmz6@gmail.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

In error cases when the ACL is insecure or we fail to allocate a new
struct sock, we jump to the "response" label.  If so, "sk" will be
null and the kernel crashes.
Signed-off-by: NNathan Holstein <nathan.holstein@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Update conf_state with L2CAP_CONF_REQ_SENT before send config_req out in
l2cap_config_req().
Signed-off-by: NHaijun Liu <haijun.liu@atheros.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

&err points to the proper error set by bt_skb_send_alloc() when it
fails.
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

BLUETOOTH SPECIFICATION Version 4.0 [Vol 3] page 36 mentioned
"Note: Start Fragments always begin with the Basic L2CAP header
of a PDU."
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Current Bluetooth code assembles fragments of big L2CAP packets
in l2cap_recv_acldata and then checks allowed L2CAP size in
assemled L2CAP packet (pi->imtu < skb->len).

The patch moves allowed L2CAP size check to the early stage when
we receive the first fragment of L2CAP packet. We do not need to
reserve and keep L2CAP fragments for bad packets.

Updated version after comments from Mat Martineau <mathewm@codeaurora.org>
and Gustavo Padovan <padovan@profusion.mobi>.

Trace below is received when using stress tools sending big
fragmented L2CAP packets.
...
[ 1712.798492] swapper: page allocation failure. order:4, mode:0x4020
[ 1712.804809] [<c0031870>] (unwind_backtrace+0x0/0xdc) from [<c00a1f70>]
(__alloc_pages_nodemask+0x4)
[ 1712.814666] [<c00a1f70>] (__alloc_pages_nodemask+0x47c/0x4d4) from
[<c00a1fd8>] (__get_free_pages+)
[ 1712.824645] [<c00a1fd8>] (__get_free_pages+0x10/0x3c) from [<c026eb5c>]
(__alloc_skb+0x4c/0xfc)
[ 1712.833465] [<c026eb5c>] (__alloc_skb+0x4c/0xfc) from [<bf28c738>]
(l2cap_recv_acldata+0xf0/0x1f8 )
[ 1712.843322] [<bf28c738>] (l2cap_recv_acldata+0xf0/0x1f8 [l2cap]) from
[<bf0094ac>] (hci_rx_task+0x)
...
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

L2CAP ERTM sockets can be opened with the SOCK_STREAM socket type,
which is a mandatory request for ERTM mode.

However, these sockets still have SOCK_SEQPACKET read semantics when
bt_sock_recvmsg() is used to pull data from the receive queue.  If the
application is only reading part of a frame, then the unread portion
of the frame is discarded.  If the application requests more bytes
than are in the current frame, only the current frame's data is
returned.

This patch utilizes common code derived from RFCOMM's recvmsg()
function to make L2CAP SOCK_STREAM reads behave like RFCOMM reads (and
other SOCK_STREAM sockets in general).  The application may read one
byte at a time from the input stream and not lose any data, and may
also read across L2CAP frame boundaries.
Signed-off-by: NMat Martineau <mathewm@codeaurora.org>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Valid L2CAP PSMs are odd numbers, and the least significant bit of the
most significant byte must be 0.
Signed-off-by: NMat Martineau <mathewm@codeaurora.org>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

L2CAP doesn't permit change like MTU, FCS, TxWindow values while the
connection is alive, we can only set that before the
connection/configuration process. That can lead to bugs in the L2CAP
operation.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

This reverts commit 8cb8e6f1.

That commit introduced a regression with the Bluetooth Profile Tuning
Suite(PTS), Reverting this make sure that L2CAP is in a qualificable
state.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

As we don't have any error control on the Streaming mode, i.e., we don't
need to keep a copy of the skb for later resending we don't need to
call skb_clone() on it.
Then we can go one further here, and dequeue the skb before sending it,
that also means we don't need to look to sk->sk_send_head anymore.

The patch saves memory and time when sending Streaming mode data, so
it is good to mainline.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

When receiving L2CAP negative configuration response with respect
to MTU parameter we modify wrong field. MTU here means proposed
value of MTU that the remote device intends to transmit. So for local
L2CAP socket it is pi->imtu.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: NVille Tervo <ville.tervo@nokia.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

This fixes a bug which caused the FCS setting to show L2CAP_FCS_CRC16
with L2CAP modes other than ERTM or streaming.  At present, this only
affects the FCS value shown with getsockopt() for basic mode.
Signed-off-by: NMat Martineau <mathewm@codeaurora.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

remote_tx_win is intended to be set on receipt of an L2CAP
configuration request.  The value is used to determine the size of the
transmit window on the remote side of an ERTM connection, so L2CAP
can stop sending frames when that remote window is full.

An incorrect remote_tx_win value will cause the stack to not fully
utilize the tx window (performance impact), or to overfill the remote
tx window (causing dropped frames or a disconnect).

This patch removes an extra setting of remote_tx_win when a
configuration response is received.  The transmit window has a
different meaning in a response - it is an informational value
less than or equal to the local tx_win.
Signed-off-by: NMat Martineau <mathewm@codeaurora.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Incoming configuration values must be converted to native CPU order
before use.  This fixes a bug where a little-endian MPS value is
compared to a native CPU value.  On big-endian processors, this
can cause ERTM and streaming mode segmentation to produce PDUs
that are larger than the remote stack is expecting, or that would
produce fragmented skbs that the current FCS code cannot handle.
Signed-off-by: NMat Martineau <mathewm@codeaurora.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Check result code of L2CAP information response. Otherwise
it would read invalid feature mask and access invalid memory.
Signed-off-by: NVille Tervo <ville.tervo@nokia.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If the remote side doesn't support Enhanced Retransmission Mode neither
Streaming Mode, we shall not send the RFC option.

Some devices that only supports Basic Mode do not understanding the RFC
option. This patch fixes the regression found with these devices.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Change the enable_ertm param to disable_ertm and default value to 0. That
means that L2CAP Extended features are enabled by default now.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

We did some changes on the L2CAP configuration process and its behaviour
is bit different now. That justifies a updated on the L2CAP version.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Copyright for the time I worked on L2CAP during the Google Summer of Code
program.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Purely a cosmetic change, it doesn't change the code flow.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Probably a typo error. We were using the wrong struct to get size.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The extended L2CAP features requires that one should initiate a
ConfigReq after send the ConnectionRsp. This patch changes the behaviour
of the configuration process of our stack.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

L2CAP only deals with ACL links. EINVAL should be returned otherwise.
Signed-off-by: NJoão Paulo Rechi Vita <jprvita@profusion.mobi>
Acked-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Signed-off-by: NJoão Paulo Rechi Vita <jprvita@profusion.mobi>
Acked-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Signed-off-by: NJoão Paulo Rechi Vita <jprvita@profusion.mobi>
Acked-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When the socket is in a bad state EBADFD is more appropriate then EINVAL.
Signed-off-by: NJoão Paulo Rechi Vita <jprvita@profusion.mobi>
Acked-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>