Impact: Attribute function with __acquires(...) resp. __releases(...).

Fix this sparse warnings:
  net/802/tr.c:492:21: warning: context imbalance in 'rif_seq_start' - wrong count at exit
  net/802/tr.c:519:13: warning: context imbalance in 'rif_seq_stop' - unexpected unlock

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The following commit introduce a regression:

	commit 7d0db0a3
	Author: Marcel Holtmann <marcel@holtmann.org>
	Date:   Mon Jul 14 20:13:51 2008 +0200

		[Bluetooth] Use a more unique bus name for connections

I get panic as following (by netconsole):

[ 2709.344034] usb 5-1: new full speed USB device using uhci_hcd and address 4
[ 2709.505776] usb 5-1: configuration #1 chosen from 1 choice
[ 2709.569207] Bluetooth: Generic Bluetooth USB driver ver 0.4
[ 2709.570169] usbcore: registered new interface driver btusb
[ 2845.742781] BUG: unable to handle kernel paging request at 6b6b6c2f
[ 2845.742958] IP: [<c015515c>] __lock_acquire+0x6c/0xa80
[ 2845.743087] *pde = 00000000
[ 2845.743206] Oops: 0002 [#1] SMP
[ 2845.743377] last sysfs file: /sys/class/bluetooth/hci0/hci0:6/type
[ 2845.743742] Modules linked in: btusb netconsole snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss rfcomm l2cap bluetooth vfat fuse snd_hda_codec_idt snd_hda_intel snd_hda_codec snd_hwdep snd_pcm pl2303 snd_timer psmouse usbserial snd 3c59x e100 serio_raw soundcore i2c_i801 intel_agp mii agpgart snd_page_alloc rtc_cmos rtc_core thermal processor rtc_lib button thermal_sys sg evdev
[ 2845.743742]
[ 2845.743742] Pid: 0, comm: swapper Not tainted (2.6.29-rc5-smp #54) Dell DM051
[ 2845.743742] EIP: 0060:[<c015515c>] EFLAGS: 00010002 CPU: 0
[ 2845.743742] EIP is at __lock_acquire+0x6c/0xa80
[ 2845.743742] EAX: 00000046 EBX: 00000046 ECX: 6b6b6b6b EDX: 00000002
[ 2845.743742] ESI: 6b6b6b6b EDI: 00000000 EBP: c064fd14 ESP: c064fcc8
[ 2845.743742]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 2845.743742] Process swapper (pid: 0, ti=c064e000 task=c05d1400 task.ti=c064e000)
[ 2845.743742] Stack:
[ 2845.743742]  c05d1400 00000002 c05d1400 00000001 00000002 00000000 f65388dc c05d1400
[ 2845.743742]  6b6b6b6b 00000292 c064fd0c c0153732 00000000 00000000 00000001 f700fa50
[ 2845.743742]  00000046 00000000 00000000 c064fd40 c0155be6 00000000 00000002 00000001
[ 2845.743742] Call Trace:
[ 2845.743742]  [<c0153732>] ? trace_hardirqs_on_caller+0x72/0x1c0
[ 2845.743742]  [<c0155be6>] ? lock_acquire+0x76/0xa0
[ 2845.743742]  [<c03e1aad>] ? skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c046c885>] ? _spin_lock_irqsave+0x45/0x80
[ 2845.743742]  [<c03e1aad>] ? skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c03e1aad>] ? skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c03e1f94>] ? skb_queue_purge+0x14/0x20
[ 2845.743742]  [<f8171f5a>] ? hci_conn_del+0x10a/0x1c0 [bluetooth]
[ 2845.743742]  [<f81399c9>] ? l2cap_disconn_ind+0x59/0xb0 [l2cap]
[ 2845.743742]  [<f81795ce>] ? hci_conn_del_sysfs+0x8e/0xd0 [bluetooth]
[ 2845.743742]  [<f8175758>] ? hci_event_packet+0x5f8/0x31c0 [bluetooth]
[ 2845.743742]  [<c03dfe19>] ? sock_def_readable+0x59/0x80
[ 2845.743742]  [<c046c14d>] ? _read_unlock+0x1d/0x20
[ 2845.743742]  [<f8178aa9>] ? hci_send_to_sock+0xe9/0x1d0 [bluetooth]
[ 2845.743742]  [<c015388b>] ? trace_hardirqs_on+0xb/0x10
[ 2845.743742]  [<f816fa6a>] ? hci_rx_task+0x2ba/0x490 [bluetooth]
[ 2845.743742]  [<c0133661>] ? tasklet_action+0x31/0xc0
[ 2845.743742]  [<c013367c>] ? tasklet_action+0x4c/0xc0
[ 2845.743742]  [<c0132eb7>] ? __do_softirq+0xa7/0x170
[ 2845.743742]  [<c0116dec>] ? ack_apic_level+0x5c/0x1c0
[ 2845.743742]  [<c0132fd7>] ? do_softirq+0x57/0x60
[ 2845.743742]  [<c01333dc>] ? irq_exit+0x7c/0x90
[ 2845.743742]  [<c01055bb>] ? do_IRQ+0x4b/0x90
[ 2845.743742]  [<c01333d5>] ? irq_exit+0x75/0x90
[ 2845.743742]  [<c010392c>] ? common_interrupt+0x2c/0x34
[ 2845.743742]  [<c010a14f>] ? mwait_idle+0x4f/0x70
[ 2845.743742]  [<c0101c05>] ? cpu_idle+0x65/0xb0
[ 2845.743742]  [<c045731e>] ? rest_init+0x4e/0x60
[ 2845.743742] Code: 0f 84 69 02 00 00 83 ff 07 0f 87 1e 06 00 00 85 ff 0f 85 08 05 00 00 8b 4d cc 8b 49 04 85 c9 89 4d d4 0f 84 f7 04 00 00 8b 75 d4 <f0> ff 86 c4 00 00 00 89 f0 e8 56 a9 ff ff 85 c0 0f 85 6e 03 00
[ 2845.743742] EIP: [<c015515c>] __lock_acquire+0x6c/0xa80 SS:ESP 0068:c064fcc8
[ 2845.743742] ---[ end trace 4c985b38f022279f ]---
[ 2845.743742] Kernel panic - not syncing: Fatal exception in interrupt
[ 2845.743742] ------------[ cut here ]------------
[ 2845.743742] WARNING: at kernel/smp.c:329 smp_call_function_many+0x151/0x200()
[ 2845.743742] Hardware name: Dell DM051
[ 2845.743742] Modules linked in: btusb netconsole snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss rfcomm l2cap bluetooth vfat fuse snd_hda_codec_idt snd_hda_intel snd_hda_codec snd_hwdep snd_pcm pl2303 snd_timer psmouse usbserial snd 3c59x e100 serio_raw soundcore i2c_i801 intel_agp mii agpgart snd_page_alloc rtc_cmos rtc_core thermal processor rtc_lib button thermal_sys sg evdev
[ 2845.743742] Pid: 0, comm: swapper Tainted: G      D    2.6.29-rc5-smp #54
[ 2845.743742] Call Trace:
[ 2845.743742]  [<c012e076>] warn_slowpath+0x86/0xa0
[ 2845.743742]  [<c015041b>] ? trace_hardirqs_off+0xb/0x10
[ 2845.743742]  [<c0146384>] ? up+0x14/0x40
[ 2845.743742]  [<c012e661>] ? release_console_sem+0x31/0x1e0
[ 2845.743742]  [<c046c8ab>] ? _spin_lock_irqsave+0x6b/0x80
[ 2845.743742]  [<c015041b>] ? trace_hardirqs_off+0xb/0x10
[ 2845.743742]  [<c046c900>] ? _read_lock_irqsave+0x40/0x80
[ 2845.743742]  [<c012e7f2>] ? release_console_sem+0x1c2/0x1e0
[ 2845.743742]  [<c0146384>] ? up+0x14/0x40
[ 2845.743742]  [<c015041b>] ? trace_hardirqs_off+0xb/0x10
[ 2845.743742]  [<c046a3d7>] ? __mutex_unlock_slowpath+0x97/0x160
[ 2845.743742]  [<c046a563>] ? mutex_trylock+0xb3/0x180
[ 2845.743742]  [<c046a4a8>] ? mutex_unlock+0x8/0x10
[ 2845.743742]  [<c015b991>] smp_call_function_many+0x151/0x200
[ 2845.743742]  [<c010a1a0>] ? stop_this_cpu+0x0/0x40
[ 2845.743742]  [<c015ba61>] smp_call_function+0x21/0x30
[ 2845.743742]  [<c01137ae>] native_smp_send_stop+0x1e/0x50
[ 2845.743742]  [<c012e0f5>] panic+0x55/0x110
[ 2845.743742]  [<c01065a8>] oops_end+0xb8/0xc0
[ 2845.743742]  [<c010668f>] die+0x4f/0x70
[ 2845.743742]  [<c011a8c9>] do_page_fault+0x269/0x610
[ 2845.743742]  [<c011a660>] ? do_page_fault+0x0/0x610
[ 2845.743742]  [<c046cbaf>] error_code+0x77/0x7c
[ 2845.743742]  [<c015515c>] ? __lock_acquire+0x6c/0xa80
[ 2845.743742]  [<c0153732>] ? trace_hardirqs_on_caller+0x72/0x1c0
[ 2845.743742]  [<c0155be6>] lock_acquire+0x76/0xa0
[ 2845.743742]  [<c03e1aad>] ? skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c046c885>] _spin_lock_irqsave+0x45/0x80
[ 2845.743742]  [<c03e1aad>] ? skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c03e1aad>] skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c03e1f94>] skb_queue_purge+0x14/0x20
[ 2845.743742]  [<f8171f5a>] hci_conn_del+0x10a/0x1c0 [bluetooth]
[ 2845.743742]  [<f81399c9>] ? l2cap_disconn_ind+0x59/0xb0 [l2cap]
[ 2845.743742]  [<f81795ce>] ? hci_conn_del_sysfs+0x8e/0xd0 [bluetooth]
[ 2845.743742]  [<f8175758>] hci_event_packet+0x5f8/0x31c0 [bluetooth]
[ 2845.743742]  [<c03dfe19>] ? sock_def_readable+0x59/0x80
[ 2845.743742]  [<c046c14d>] ? _read_unlock+0x1d/0x20
[ 2845.743742]  [<f8178aa9>] ? hci_send_to_sock+0xe9/0x1d0 [bluetooth]
[ 2845.743742]  [<c015388b>] ? trace_hardirqs_on+0xb/0x10
[ 2845.743742]  [<f816fa6a>] hci_rx_task+0x2ba/0x490 [bluetooth]
[ 2845.743742]  [<c0133661>] ? tasklet_action+0x31/0xc0
[ 2845.743742]  [<c013367c>] tasklet_action+0x4c/0xc0
[ 2845.743742]  [<c0132eb7>] __do_softirq+0xa7/0x170
[ 2845.743742]  [<c0116dec>] ? ack_apic_level+0x5c/0x1c0
[ 2845.743742]  [<c0132fd7>] do_softirq+0x57/0x60
[ 2845.743742]  [<c01333dc>] irq_exit+0x7c/0x90
[ 2845.743742]  [<c01055bb>] do_IRQ+0x4b/0x90
[ 2845.743742]  [<c01333d5>] ? irq_exit+0x75/0x90
[ 2845.743742]  [<c010392c>] common_interrupt+0x2c/0x34
[ 2845.743742]  [<c010a14f>] ? mwait_idle+0x4f/0x70
[ 2845.743742]  [<c0101c05>] cpu_idle+0x65/0xb0
[ 2845.743742]  [<c045731e>] rest_init+0x4e/0x60
[ 2845.743742] ---[ end trace 4c985b38f02227a0 ]---
[ 2845.743742] ------------[ cut here ]------------
[ 2845.743742] WARNING: at kernel/smp.c:226 smp_call_function_single+0x8e/0x110()
[ 2845.743742] Hardware name: Dell DM051
[ 2845.743742] Modules linked in: btusb netconsole snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss rfcomm l2cap bluetooth vfat fuse snd_hda_codec_idt snd_hda_intel snd_hda_codec snd_hwdep snd_pcm pl2303 snd_timer psmouse usbserial snd 3c59x e100 serio_raw soundcore i2c_i801 intel_agp mii agpgart snd_page_alloc rtc_cmos rtc_core thermal processor rtc_lib button thermal_sys sg evdev
[ 2845.743742] Pid: 0, comm: swapper Tainted: G      D W  2.6.29-rc5-smp #54
[ 2845.743742] Call Trace:
[ 2845.743742]  [<c012e076>] warn_slowpath+0x86/0xa0
[ 2845.743742]  [<c012e000>] ? warn_slowpath+0x10/0xa0
[ 2845.743742]  [<c015041b>] ? trace_hardirqs_off+0xb/0x10
[ 2845.743742]  [<c0146384>] ? up+0x14/0x40
[ 2845.743742]  [<c012e661>] ? release_console_sem+0x31/0x1e0
[ 2845.743742]  [<c046c8ab>] ? _spin_lock_irqsave+0x6b/0x80
[ 2845.743742]  [<c015041b>] ? trace_hardirqs_off+0xb/0x10
[ 2845.743742]  [<c046c900>] ? _read_lock_irqsave+0x40/0x80
[ 2845.743742]  [<c012e7f2>] ? release_console_sem+0x1c2/0x1e0
[ 2845.743742]  [<c0146384>] ? up+0x14/0x40
[ 2845.743742]  [<c015b7be>] smp_call_function_single+0x8e/0x110
[ 2845.743742]  [<c010a1a0>] ? stop_this_cpu+0x0/0x40
[ 2845.743742]  [<c026d23f>] ? cpumask_next_and+0x1f/0x40
[ 2845.743742]  [<c015b95a>] smp_call_function_many+0x11a/0x200
[ 2845.743742]  [<c010a1a0>] ? stop_this_cpu+0x0/0x40
[ 2845.743742]  [<c015ba61>] smp_call_function+0x21/0x30
[ 2845.743742]  [<c01137ae>] native_smp_send_stop+0x1e/0x50
[ 2845.743742]  [<c012e0f5>] panic+0x55/0x110
[ 2845.743742]  [<c01065a8>] oops_end+0xb8/0xc0
[ 2845.743742]  [<c010668f>] die+0x4f/0x70
[ 2845.743742]  [<c011a8c9>] do_page_fault+0x269/0x610
[ 2845.743742]  [<c011a660>] ? do_page_fault+0x0/0x610
[ 2845.743742]  [<c046cbaf>] error_code+0x77/0x7c
[ 2845.743742]  [<c015515c>] ? __lock_acquire+0x6c/0xa80
[ 2845.743742]  [<c0153732>] ? trace_hardirqs_on_caller+0x72/0x1c0
[ 2845.743742]  [<c0155be6>] lock_acquire+0x76/0xa0
[ 2845.743742]  [<c03e1aad>] ? skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c046c885>] _spin_lock_irqsave+0x45/0x80
[ 2845.743742]  [<c03e1aad>] ? skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c03e1aad>] skb_dequeue+0x1d/0x70
[ 2845.743742]  [<c03e1f94>] skb_queue_purge+0x14/0x20
[ 2845.743742]  [<f8171f5a>] hci_conn_del+0x10a/0x1c0 [bluetooth]
[ 2845.743742]  [<f81399c9>] ? l2cap_disconn_ind+0x59/0xb0 [l2cap]
[ 2845.743742]  [<f81795ce>] ? hci_conn_del_sysfs+0x8e/0xd0 [bluetooth]
[ 2845.743742]  [<f8175758>] hci_event_packet+0x5f8/0x31c0 [bluetooth]
[ 2845.743742]  [<c03dfe19>] ? sock_def_readable+0x59/0x80
[ 2845.743742]  [<c046c14d>] ? _read_unlock+0x1d/0x20
[ 2845.743742]  [<f8178aa9>] ? hci_send_to_sock+0xe9/0x1d0 [bluetooth]
[ 2845.743742]  [<c015388b>] ? trace_hardirqs_on+0xb/0x10
[ 2845.743742]  [<f816fa6a>] hci_rx_task+0x2ba/0x490 [bluetooth]
[ 2845.743742]  [<c0133661>] ? tasklet_action+0x31/0xc0
[ 2845.743742]  [<c013367c>] tasklet_action+0x4c/0xc0
[ 2845.743742]  [<c0132eb7>] __do_softirq+0xa7/0x170
[ 2845.743742]  [<c0116dec>] ? ack_apic_level+0x5c/0x1c0
[ 2845.743742]  [<c0132fd7>] do_softirq+0x57/0x60
[ 2845.743742]  [<c01333dc>] irq_exit+0x7c/0x90
[ 2845.743742]  [<c01055bb>] do_IRQ+0x4b/0x90
[ 2845.743742]  [<c01333d5>] ? irq_exit+0x75/0x90
[ 2845.743742]  [<c010392c>] common_interrupt+0x2c/0x34
[ 2845.743742]  [<c010a14f>] ? mwait_idle+0x4f/0x70
[ 2845.743742]  [<c0101c05>] cpu_idle+0x65/0xb0
[ 2845.743742]  [<c045731e>] rest_init+0x4e/0x60
[ 2845.743742] ---[ end trace 4c985b38f02227a1 ]---
[ 2845.743742] Rebooting in 3 seconds..

My logitec bluetooth mouse trying connect to pc, but
pc side reject the connection again and again. then panic happens.

The reason is due to hci_conn_del_sysfs now called in hci_event_packet,
the del work is done in a workqueue, so it's possible done before
skb_queue_purge called.

I move the hci_conn_del_sysfs after skb_queue_purge just as that before
marcel's commit.

Remove the hci_conn_del_sysfs in hci_conn_hash_flush as well due to
hci_conn_del will deal with the work.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Userspace pairing code can be simplified if it doesn't have to fall
back to using L2CAP_LM in the case of L2CAP raw sockets. This patch
allows the BT_SECURITY socket option to be used for these sockets.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The CID value of L2CAP sockets need to be set to zero. All userspace
applications do this via memset() on the sockaddr_l2 structure. The
RFCOMM implementation uses in-kernel L2CAP sockets and so it has to
make sure that l2_cid is set to zero.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

In the future the L2CAP layer will have full support for fixed channels
and right now it already can export the channel assignment, but for the
functions bind() and connect() the usage of only CID 0 is allowed. This
allows an easy detection if the kernel supports fixed channels or not,
because otherwise it would impossible for application to tell.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When BT_DEFER_SETUP is enabled on a RFCOMM socket, then switch its
current state from BT_OPEN to BT_CONNECT2. This gives the Bluetooth
core a unified way to handle L2CAP and RFCOMM sockets. The BT_CONNECT2
state is designated for incoming connections.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When BT_DEFER_SETUP has been enabled on a Bluetooth socket it keeps
signaling POLLIN all the time. This is a wrong behavior. The POLLIN
should only be signaled if the client socket is in BT_CONNECT2 state
and the parent has been BT_DEFER_SETUP enabled.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The authentication requirement got only updated when the security level
increased. This is a wrong behavior. The authentication requirement is
read by the Bluetooth daemon to make proper decisions when handling the
IO capabilities exchange. So set the value that is currently expected by
the higher layers like L2CAP and RFCOMM.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The L2CAP layer can trigger the authentication via an ACL connection or
later on to increase the security level. When increasing the security
level it didn't use the same authentication requirements when triggering
a new ACL connection. Make sure that exactly the same authentication
requirements are used. The only exception here are the L2CAP raw sockets
which are only used for dedicated bonding.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Some of the qualification tests demand that in case of failures in L2CAP
the HCI disconnect should indicate a reason why L2CAP fails. This is a
bluntly layer violation since multiple L2CAP connections could be using
the same ACL and thus forcing a disconnect reason is not a good idea.

To comply with the Bluetooth test specification, the disconnect reason
is now stored in the L2CAP connection structure and every time a new
L2CAP channel is added it will set back to its default. So only in the
case where the L2CAP channel with the disconnect reason is really the
last one, it will propagated to the HCI layer.

The HCI layer has been extended with a disconnect indication that allows
it to ask upper layers for a disconnect reason. The upper layer must not
support this callback and in that case it will nicely default to the
existing behavior. If an upper layer like L2CAP can provide a disconnect
reason that one will be used to disconnect the ACL or SCO link.

No modification to the ACL disconnect timeout have been made. So in case
of Linux to Linux connection the initiator will disconnect the ACL link
before the acceptor side can signal the specific disconnect reason. That
is perfectly fine since Linux doesn't make use of this value anyway. The
L2CAP layer has a perfect valid error code for rejecting connection due
to a security violation. It is unclear why the Bluetooth specification
insists on having specific HCI disconnect reason.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

In preparation for L2CAP fixed channel support, the CID value of a
L2CAP connection needs to be accessible via the socket interface. The
CID is the connection identifier and exists as source and destination
value. So extend the L2CAP socket address structure with this field and
change getsockname() and getpeername() to fill it in.

The bind() and connect() functions have been modified to handle L2CAP
socket address structures of variable sizes. This makes them future
proof if additional fields need to be added.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If the extended features mask indicates support for fixed channels,
request the list of available fixed channels. This also enables the
fixed channel features bit so remote implementations can request
information about it. Currently only the signal channel will be
listed.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The recommendation for the L2CAP PSM 1 (SDP) is to not use any kind
of authentication or encryption. So don't trigger authentication
for incoming and outgoing SDP connections.

For L2CAP PSM 3 (RFCOMM) there is no clear requirement, but with
Bluetooth 2.1 the initiator is required to enable authentication
and encryption first and this gets enforced. So there is no need
to trigger an additional authentication step. The RFCOMM service
security will make sure that a secure enough link key is present.

When the encryption gets enabled after the SDP connection setup,
then switch the security level from SDP to low security.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

If the remote L2CAP server uses authentication pending stage and
encryption is enabled it can happen that a L2CAP connection request is
sent twice due to a race condition in the connection state machine.

When the remote side indicates any kind of connection pending, then
track this state and skip sending of L2CAP commands for this period.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When two L2CAP connections are requested quickly after the ACL link has
been established there exists a window for a race condition where a
connection request is sent before the information response has been
received. Any connection request should only be sent after an exchange
of the extended features mask has been finished.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When no authentication requirements are selected, but an outgoing or
incoming connection has requested any kind of security enforcement,
then set these authentication requirements.

This ensures that the userspace always gets informed about the
authentication requirements (if available). Only when no security
enforcement has happened, the kernel will signal invalid requirements.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When receiving incoming connection to specific services, always use
general bonding. This ensures that the link key gets stored and can be
used for further authentications.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When attempting to setup eSCO connections it can happen that some link
manager implementations fail to properly negotiate the eSCO parameters
and thus fail the eSCO setup. Normally the link manager is responsible
for the negotiation of the parameters and actually fallback to SCO if
no agreement can be reached. In cases where the link manager is just too
stupid, then at least try to establish a SCO link if eSCO fails.

For the Bluetooth devices with EDR support this includes handling packet
types of EDR basebands. This is particular tricky since for the EDR the
logic of enabling/disabling one specific packet type is turned around.
This fix contains an extra bitmask to disable eSCO EDR packet when
trying to fallback to a SCO connection.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

For L2CAP sockets with medium and high security requirement a missing
encryption will enforce the closing of the link. For the L2CAP raw
sockets this is not needed, so skip that check.

This fixes a crash when pairing Bluetooth 2.0 (and earlier) devices
since the L2CAP state machine got confused and then locked up the whole
system.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

During a role change with pre-Bluetooth 2.1 devices, the remote side drops
the encryption of the RFCOMM connection. We allow a grace period for the
encryption to be re-established, before dropping the connection. During
this grace period, the RFCOMM_SEC_PENDING flag is set. Check this flag
before sending RFCOMM packets.

Signed-off-by: Jaikumar Ganesh <jaikumar@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Due to lockdep changes, the CONFIG_DEBUG_LOCK_ALLOC ifdef is not needed
now. So just remove it here.

The following commit fixed the !lockdep build warnings:

commit e8f6fbf6
Author: Ingo Molnar <mingo@elte.hu>
Date:   Wed Nov 12 01:38:36 2008 +0000

    lockdep: include/linux/lockdep.h - fix warning in net/bluetooth/af_bluetooth.c

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

With the support for the enhanced security model and the support for
deferring connection setup, it is a good idea to increase various
version numbers.

This is purely cosmetic and has no effect on the behavior, but can
be really helpful when debugging problems in different kernel versions.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The new socket options should only be evaluated for SOL_BLUETOOTH level
and not for every other level. Previously this causes some minor issues
when detecting if a kernel with certain features is available.

Also restrict BT_SECURITY to SOCK_SEQPACKET for L2CAP and SOCK_STREAM for
the RFCOMM protocol.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

For L2CAP connections with high security setting, the link will be
immediately dropped when the encryption gets disabled. For L2CAP
connections with medium security there will be grace period where
the remote device has the chance to re-enable encryption. If it
doesn't happen then the link will also be disconnected.

The requirement for the grace period with medium security comes from
Bluetooth 2.0 and earlier devices that require role switching.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

A role switch with devices following the Bluetooth pre-2.1 standards
or without Encryption Pause and Resume support is not possible if
encryption is enabled. Most newer headsets require the role switch,
but also require that the connection is encrypted.

For connections with a high security mode setting, the link will be
immediately dropped. When the connection uses medium security mode
setting, then a grace period is introduced where the TX is halted and
the remote device gets a change to re-enable encryption after the
role switch. If not re-enabled the link will be dropped.

Based on initial work by Ville Tervo <ville.tervo@nokia.com>

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Change the RFCOMM internals to use the new security levels and remove
the link mode details.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Change the L2CAP internals to use the new security levels and remove
the link mode details.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The current security model is based around the flags AUTH, ENCRYPT and
SECURE. Starting with support for the Bluetooth 2.1 specification this is
no longer sufficient. The different security levels are now defined as
SDP, LOW, MEDIUM and SECURE.

Previously it was possible to set each security independently, but this
actually doesn't make a lot of sense. For Bluetooth the encryption depends
on a previous successful authentication. Also you can only update your
existing link key if you successfully created at least one before. And of
course the update of link keys without having proper encryption in place
is a security issue.

The new security levels from the Bluetooth 2.1 specification are now
used internally. All old settings are mapped to the new values and this
way it ensures that old applications still work. The only limitation
is that it is no longer possible to set authentication without also
enabling encryption. No application should have done this anyway since
this is actually a security issue. Without encryption the integrity of
the authentication can't be guaranteed.

As default for a new L2CAP or RFCOMM connection, the LOW security level
is used. The only exception here are the service discovery sessions on
PSM 1 where SDP level is used. To have similar security strength as with
a Bluetooth 2.0 and before combination key, the MEDIUM level should be
used. This is according to the Bluetooth specification. The MEDIUM level
will not require any kind of man-in-the-middle (MITM) protection. Only
the HIGH security level will require this.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

When the remote device supports only SCO connections, on receipt of
the HCI_EV_CONN_COMPLETE event packet, the connect state is changed to
BT_CONNECTED, but the socket state is not updated. Hence, the connect()
call times out even though the SCO connection has been successfully
established.

Based on a report by Jaikumar Ganesh <jaikumar@google.com>

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>