The poll() changes were not well thought out, and completely
unexplained. They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.
Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead. That gets rid of one of the new indirections.
But that doesn't fix the new complexity that is completely unwarranted
for the regular case. The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.
[ This revert is a revert of about 30 different commits, not reverted
individually because that would just be unnecessarily messy - Linus ]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Changes since v1:
Added changes in these files:
drivers/infiniband/hw/usnic/usnic_transport.c
drivers/staging/lustre/lnet/lnet/lib-socket.c
drivers/target/iscsi/iscsi_target_login.c
drivers/vhost/net.c
fs/dlm/lowcomms.c
fs/ocfs2/cluster/tcp.c
security/tomoyo/network.c
Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.
"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.
None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.
This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.
Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.
rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.
Userspace API is not changed.
text data bss dec hex filename
30108430 2633624 873672 33615726 200ef6e vmlinux.before.o
30108109 2633612 873672 33615393 200ee21 vmlinux.o
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Verify that the caller-provided sockaddr structure is large enough to
contain the sa_family field, before accessing it in bind() and connect()
handlers of the Bluetooth sockets. Since neither syscall enforces a minimum
size of the corresponding memory region, very short sockaddrs (zero or one
byte long) result in operating on uninitialized memory while referencing
sa_family.
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.
The theory lockdep comes up with is as follows:
(1) If the pagefault handler decides it needs to read pages from AFS, it
calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
creating a call requires the socket lock:
mmap_sem must be taken before sk_lock-AF_RXRPC
(2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind()
binds the underlying UDP socket whilst holding its socket lock.
inet_bind() takes its own socket lock:
sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET
(3) Reading from a TCP socket into a userspace buffer might cause a fault
and thus cause the kernel to take the mmap_sem, but the TCP socket is
locked whilst doing this:
sk_lock-AF_INET must be taken before mmap_sem
However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks. The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace. This is
a limitation in the design of lockdep.
Fix the general case by:
(1) Double up all the locking keys used in sockets so that one set are
used if the socket is created by userspace and the other set is used
if the socket is created by the kernel.
(2) Store the kern parameter passed to sk_alloc() in a variable in the
sock struct (sk_kern_sock). This informs sock_lock_init(),
sock_init_data() and sk_clone_lock() as to the lock keys to be used.
Note that the child created by sk_clone_lock() inherits the parent's
kern setting.
(3) Add a 'kern' parameter to ->accept() that is analogous to the one
passed in to ->create() that distinguishes whether kernel_accept() or
sys_accept4() was the caller and can be passed to sk_alloc().
Note that a lot of accept functions merely dequeue an already
allocated socket. I haven't touched these as the new socket already
exists before we get the parameter.
Note also that there are a couple of places where I've made the accepted
socket unconditionally kernel-based:
irda_accept()
rds_rcp_accept_one()
tcp_accept_from_sock()
because they follow a sock_create_kern() and accept off of that.
Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal. I wonder if these should do that so
that they use the new set of lock keys.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix up affected files that include this signal functionality via sched.h.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The hci_get_route() API is used to look up local HCI devices, however
so far it has been incapable of dealing with anything else than the
public address of HCI devices. This completely breaks with LE-only HCI
devices that do not come with a public address, but use a static
random address instead.
This patch exteds the hci_get_route() API with a src_type parameter
that's used for comparing with the right address of each HCI device.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Lets fix this obvious coding style issues in the SCO module and bring it
in line with the rest of the Bluetooth subsystem.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This makes the function sco_conn_del have a return type of void now
due to this function always running successfully and thus never
needing to signal its caller when a non recoverable internal failure
occurs by returning a error code to its respective caller.
Signed-off-by: Nicholas Krause <xerofoify@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>
In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While compiling the following warning occurs:
WARNING: net/built-in.o(.init.text+0x602c): Section mismatch in
reference from the function bt_init() to the function
.exit.text:sco_exit()
The function __init bt_init() references
a function __exit sco_exit().
This is often seen when error handling in the init function
uses functionality in the exit path.
The fix is often to remove the __exit annotation of
sco_exit() so it may be used outside an exit section.
Since commit 6d785aa345 ("Bluetooth:
Convert mgmt to use HCI chan registration API") the function "sco_exit"
is used inside of function "bt_init". The suggested solution by remove
the __exit annotation solved this issue.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Johan Hedberg says:
====================
pull request: bluetooth-next 2015-03-02
Here's the first bluetooth-next pull request targeting the 4.1 kernel:
- ieee802154/6lowpan cleanups
- SCO routing to host interface support for the btmrvl driver
- AMP code cleanups
- Fixes to AMP HCI init sequence
- Refactoring of the HCI callback mechanism
- Added shutdown routine for Intel controllers in the btusb driver
- New config option to enable/disable Bluetooth debugfs information
- Fix for early data reception on L2CAP fixed channels
Please let me know if there are any issues pulling. Thanks.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.
Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
l2cap/rfcomm/sco_sock_accept() are wait loops which may acquire
sleeping locks. Since both wait loops and sleeping locks use
task_struct.state to sleep and wake, the nested sleeping locks
destroy the wait loop state.
Use the newly-minted wait_woken() and DEFINE_WAIT_FUNC() for the
wait loop. DEFINE_WAIT_FUNC() allows an alternate wake function
to be specified; in this case, the predefined scheduler function,
woken_wake_function(). This wait construct ensures wakeups will
not be missed without requiring the wait loop to set the
task state before condition evaluation. How this works:
CPU 0 | CPU 1
|
| is <condition> set?
| no
set <condition> |
|
wake_up_interruptible |
woken_wake_function |
set WQ_FLAG_WOKEN |
try_to_wake_up |
| wait_woken
| set TASK_INTERRUPTIBLE
| WQ_FLAG_WOKEN? yes
| set TASK_RUNNING
|
| - loop -
|
| is <condition> set?
| yes - exit wait loop
Fixes "do not call blocking ops when !TASK_RUNNING" warnings
in l2cap_sock_accept(), rfcomm_sock_accept() and sco_sock_accept().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This adds an extra check for ensuring that the size of sockaddr_sco
does not grow larger than sockaddr.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
If the current process is exiting, lingering on socket close will make
it unkillable, so we should avoid it.
Reproducer:
#include <sys/types.h>
#include <sys/socket.h>
#define BTPROTO_L2CAP 0
#define BTPROTO_SCO 2
#define BTPROTO_RFCOMM 3
int main()
{
int fd;
struct linger ling;
fd = socket(PF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM);
//or: fd = socket(PF_BLUETOOTH, SOCK_DGRAM, BTPROTO_L2CAP);
//or: fd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_SCO);
ling.l_onoff = 1;
ling.l_linger = 1000000000;
setsockopt(fd, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling));
return 0;
}
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
The sco_chan_get helper function is only used in two places and really
only protects conn->sk with a lock. So instead of hiding that fact,
just put the actual code in place where it is used.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The forward declaration of sco_chan_del is not needed and thus just
remove it. Move sco_chan_del into the proper location.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The forward declaration of __sco_chan_add is not needed and thus just
remove it. Move __sco_chan_add into the proper location.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
There is no external user of the SCO timeout constants and thus
move them into net/bluetooth/sco.c where they are actuallu used.
In addition just remove SCO_CONN_IDLE_TIMEOUT since it is unused.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
There exists no external user of struct sco_conn and thus move
it into the one place that is actually using it.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
There exists no external user of struct sco_pinfo and sco_pi and
thus move it into the one place that is actually using it.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Several spots in the kernel perform a sequence like:
skb_queue_tail(&sk->s_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);
But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up. So this skb->len access is potentially
to freed up memory.
Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.
And finally, no actual implementation of this callback actually uses
the length argument. And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.
So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.
Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.
Signed-off-by: David S. Miller <davem@davemloft.net>
The use of __constant_<foo> has been unnecessary for quite awhile now.
Make these uses consistent with the rest of the kernel.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.
This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.
Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.
Also document these changes in include/linux/net.h as suggested by David
Miller.
Changes since RFC:
Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.
With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
msg->msg_name = NULL
".
This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.
Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.
Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sure to use IS_ERR_OR_NULL for checking the existing of the root
debugfs dentry bt_debugfs.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The address information of SCO sockets should be stored in its own
socket structure. Trying to generalize them is not helpful since
different transports have different address types.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Instead of storing a pointer to the addresses for the HCI device
and HCI connection, use them directly. With the recent changes
to address tracking of HCI connections, this becomes simple.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Older Bluetooth devices may not support Setup Synchronous Connection or
SCO transparent data. This is indicated by the corresponding LMP feature
bits. It is not possible to know if the adapter support these features
before setting BT_VOICE option since the socket is not bound to an
adapter. An adapter can also be added after the socket is created. The
socket can be bound to an address before adapter is plugged in.
Thus, on a such adapters, if user request BT_VOICE_TRANSPARENT, outgoing
connections fail on connect() and returns -EOPNOTSUPP. Incoming
connections do not fail. However, they should only be allowed depending
on what was specified in Write_Voice_Settings command.
EOPNOTSUPP is choosen because connect() system call is failing after
selecting route but before any connection attempt.
Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
In order to establish a transparent SCO connection, the correct settings
must be specified in the Setup Synchronous Connection request. For that,
a setting field is added to ACL connection data to set up the desired
parameters. The patch also removes usage of hdev->voice_setting in CVSD
connection and makes use of T2 parameters for transparent data.
Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When an incoming eSCO connection is requested, check the selected voice
setting and reply appropriately. Voice setting should have been
negotiated previously. For example, in case of HFP, the codec is
negotiated using AT commands on the RFCOMM channel. This patch only
changes replies for socket with deferred setup enabled.
Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch extends the current Bluetooth socket options with BT_VOICE.
This is intended to choose voice data type at runtime. It only applies
to SCO sockets. Incoming connections shall be setup during deferred
setup. Outgoing connections shall be setup before connect(). The desired
setting is stored in the SCO socket info. This patch declares needed
members, modifies getsockopt() and setsockopt().
Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
From Bluetooth Core v4.0 specification, 7.1.8 Accept Connection Request
Command "When accepting synchronous connection request, the Role
parameter is not used and will be ignored by the BR/EDR Controller."
Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
hci_connect is a super function for connecting hci protocols. But the
voice_setting parameter (introduced in subsequent patches) is only
needed by SCO and security requirements are not needed for SCO channels.
Thus, it makes sense to have a separate function for SCO.
Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When a socket is in deferred state there does actually exist an
underlying connection even though the connection state is not yet
BT_CONNECTED. In the deferred state it should therefore be allowed to
get socket options that usually depend on a connection, such as
SCO_OPTIONS and SCO_CONNINFO.
This patch fixes the behavior of some user space code that behaves as
follows without it:
$ sudo tools/btiotest -i 00:1B:DC:xx:xx:xx -d -s
accept=2 reject=-1 discon=-1 defer=1 sec=0 update_sec=0 prio=0 voice=0x0000
Listening for SCO connections
bt_io_get(OPT_DEST): getsockopt(SCO_OPTIONS): Transport endpoint is not connected (107)
Accepting connection
Successfully connected to 60:D8:19:xx:xx:xx. handle=43, class=000000
The conditions that the patch updates the if-statements to is taken from
similar code in l2cap_sock.c which correctly handles the deferred state.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).
7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
Since this function is only used by sco, move it from hci_event.c to
sco.c and rename to sco_conn_defer_accept. Make it static.
Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>