Recently the LE passive scanning and auto-connections feature was
introduced. It uses the hci_connect_le() API which returns a hci_conn
along with a reference count to that object. All previous users would
tie this returned reference to some existing object, such as an L2CAP
channel, and there'd be no leaked references this way. For
auto-connections however the reference was returned but not stored
anywhere, leaving established connections with one higher reference
count than they should have.
Instead of playing special tricks with hci_conn_hold/drop this patch
associates the returned reference from hci_connect_le() with the object
that in practice does own this reference, i.e. the hci_conn_params
struct that caused us to initiate a connection in the first place. Once
the connection is established or fails to establish this reference is
removed appropriately.
One extra thing needed is to call hci_pend_le_actions_clear() before
calling hci_conn_hash_flush() so that the reference is cleared before
the hci_conn objects are fully removed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.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>
There is no need to decrease pdu size with L2CAP SDU lenght in Start
L2CAP SDU frame. Start packtet is just 2 bytes longer as specified and
we can keep payload as long as possible.
When testing SAR L2CAP against PTS, L2CAP channel is usually configured
in that way, that SDU = MPS * 3. PTS expets then 3 I-Frames from IUT: Start,
Continuation and End frame.
Without this fix, we sent 4 I-Frames. We could pass a test by using -b
option in l2test and send just two bytes less than SDU length. With this
patch no need to use -b option.
Signed-off-by: Lukasz Rymanowski <lukasz.rymanowski@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There are no external users of smp_chan_destroy() so make it private to
smp.c. The patch also moves the function higher up in the c-file in
order to avoid forward declarations.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The smp_distribute_keys() function calls smp_notify_keys() which in turn
calls l2cap_conn_update_id_addr(). The l2cap_conn_update_id_addr()
function will iterate through all L2CAP channels for the respective
connection: lock the channel, update the address information and unlock
the channel.
Since SMP is now using l2cap_chan callbacks each callback is called with
the channel lock held. Therefore, calling l2cap_conn_update_id_addr()
would cause a deadlock calling l2cap_chan_lock() on the SMP channel.
This patch moves calling smp_distribute_keys() through a workqueue so
that it is never called from an L2CAP channel callback.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
All places needing to cancel the security timer also call
smp_chan_destroy() in the same go. To eliminate the need to do these two
calls in multiple places simply move the timer cancellation into
smp_chan_destroy().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that there are no-longer any users for l2cap_conn->security_timer we
can go ahead and simply remove it. The patch makes initialization of the
conn->info_timer unconditional since it's better not to leave any
l2cap_conn data structures uninitialized no matter what the underlying
transport.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds an SMP-internal timeout callback to remove the depenency
on (the soon to be removed) l2cap_conn->security_timer. The behavior is
the same as with l2cap_conn->security_timer except that the new
l2cap_conn_shutdown() public function is used instead of the L2CAP core
internal l2cap_conn_del().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the case that the SMP recv callback returns error the calling code in
l2cap_core.c expects that it still owns the skb and will try to free it.
The SMP code should therefore not try to free the skb if it return an
error. This patch fixes such behavior in the SMP command handler
function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To restore pre-l2cap_chan functionality we should be trying to
disconnect the connection when receviving garbage SMP data (i.e. when
the SMP command handler fails). This patch renames the command handler
back to smp_sig_channel() and adds a smp_recv_cb() wrapper function for
calling it. If smp_sig_channel() fails the code calls
l2cap_conn_shutdown().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since we no-longer do special handling of SMP within l2cap_core.c we
don't have any code for calling l2cap_conn_del() when smp.c doesn't like
the data it gets. At the same time we cannot simply export
l2cap_conn_del() since it will try to lock the channels it calls into
whereas we already hold the lock in the smp.c l2cap_chan callbacks (i.e.
it'd lead to a deadlock).
This patch adds a new l2cap_conn_shutdown() API which is very similar to
l2cap_conn_del() except that it defers the call to l2cap_conn_del()
through a workqueue, thereby making it safe to use it from an L2CAP
channel callback.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no need to export the smp_distribute_keys() function since the
resume callback is called in the same scenario. This patch makes the
smp_notify_keys function private (at the same time moving it higher up
in smp.c to avoid forward declarations) and adds a resume callback for
SMP to call it from there instead.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that we have all the necessary pieces in place we can fully convert
SMP to use the L2CAP channel infrastructure. This patch adds the
necessary callbacks and removes the now unneeded conn->smp_chan pointer.
One notable behavioral change in this patch comes from the following
code snippet:
- case L2CAP_CID_SMP:
- if (smp_sig_channel(conn, skb))
- l2cap_conn_del(conn->hcon, EACCES);
This piece of code was essentially forcing a disconnection if garbage
SMP data was received. The l2cap_conn_del() function is private to
l2cap_conn.c so we don't have access to it anymore when using the L2CAP
channel callbacks. Therefore, the behavior of the new code is simply to
return errors in the recv() callback (which is simply the old
smp_sig_channel()), but no disconnection will occur.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that we have per-adapter SMP data thanks to the root SMP L2CAP
channel we can take advantage of it and attach the AES crypto context
(only used for SMP) to it. This means that the smp_irk_matches() and
smp_generate_rpa() function can be converted to internally handle the
AES context.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch creates the initial SMP L2CAP channels and a skeleton for
their callbacks. There is one per-adapter channel created upon adapter
registration, and then one channel per-connection created through the
new_connection callback. The channels are registered with the reserved
CID 0x1f for now in order to not conflict with existing SMP
functionality. Once everything is in place the value can be changed to
what it should be, i.e. L2CAP_CID_SMP.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
First of all, it's wasteful to initialize SMP if it's never going to be
used (e.g. on non-LE controllers). Second of all, when we move to use
l2cap_chan we need to know the real local address, meaning we must have
completed at least part of the HCI init. This patch moves the SMP
initialization to after the HCI init procedure and makes it depend on
whether the controller actually supports LE.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
As preparation for converting SMP to use the l2cap_chan infrastructure
refactor the (de)initialization into separate functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If the AES crypto has not been initialized properly we should cleanly
return from the hci_find_irk_by_rpa() function. Right now this will not
happen in practice, but once (in subsequent patches) SMP init is moved
to after the HCI init procedure it is possible that the pointer is NULL.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If the AES crypto context is not available we cannot generate new RPAs.
We should therefore cleanly return an error from the function
responsible for updating the random address.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For most cases it makes no difference whether l2cap_le_conn_ready() is
called before or after calling the channel ready() callbacks, however
for upcoming SMP code we need this as the ready() callback initializes
certain structures that a call to smp_conn_security() from
l2cap_le_conn_ready() depends on. Therefore, move the call to
l2cap_le_conn_ready() after iterating through and notifying channels.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
L2CAP channel implementations may want to still access the chan->conn
pointer. This will particularly be the case for SMP that will want to
clear a reference to the SMP channel in the l2cap_conn structure. The
only user of the teardown callback so far is l2cap_sock.c and for the
code there it makes no difference whether the callback is called before
or after clearing the chan->conn pointer.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The l2cap_add_scid function is used for registering a fixed L2CAP
channel. Instead of having separate initialization of the channel type
and outgoing MTU in l2cap_sock.c it's more intuitive to do these things
in the l2cap_add_scid function itself (and thereby make the
functionality available to other users besides l2cap_sock.c).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that we've got the fixed channel infrastructure cleaned up in a
generic way there's no longer a need to have a dedicated function for
handling data on the ATT channel. Instead the generic
l2cap_data_channel() handler will be able to do the exact same thing.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When notifying global fixed channels of new connections it doesn't make
sense to consider channels meant for a different link type than the one
available. This patch adds an extra parameter to the
l2cap_global_fixed_chan() lookup function and ensures that only channels
matching the current hci_conn type are looked up.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In order to remove special handling of fixed L2CAP channels we need to
start creating them in a single place instead of having per-channel
exceptions. The most natural place is the l2cap_conn_cfm() function
which is called whenever there is a new baseband link.
The only really special case so far has been the ATT socket, so in order
not to break the code in between this patch removes the ATT special
handling at the same time as it adds the generic fixed channel handling
from l2cap_le_conn_ready() into the hci_conn_cfm() function. As a
related change the channel locking in l2cap_conn_ready() becomes simpler
and we can thereby move the smp_conn_security() call into the
l2cap_le_conn_ready() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch is a simple refactoring of l2cap_connect_cfm to allow easier
extension of the function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
With the update to sk->resume() and __l2cap_no_conn_pending() we
no-longer need to have special handling of ATT channels in the
l2cap_security_cfm() function. The chan->sec_level update when
encryption has been enabled is safe to do for any kind of channel, and
the loop takes later care of calling chan->ready() or chan->resume() if
necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The LE ATT socket uses a special trick where it temporarily sets
BT_CONFIG state for the duration of a security level elevation. In order
to not require special hacks for going back to BT_CONNECTED state in the
l2cap_core.c code the most reasonable place to resume the state is the
resume callback. This patch adds a new flag to track the pending
security level change and ensures that the state is set back to
BT_CONNECTED in the resume callback in case the flag is set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The __l2cap_no_conn_pending() function would previously only return a
meaningful value for connection oriented channels and was therefore not
useful for anything else. As preparation of making the L2CAP code more
generic allow the function to be called for other channel types as well
by returning a meaningful value for them.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When looking up entries from the global L2CAP channel list there needs
to be a guarantee that other code doesn't go and remove the entry after
a channel has been returned by the lookup function. This patch makes
sure that the channel reference is incremented before the read lock is
released in the global channel lookup functions. The patch also adds the
corresponding l2cap_chan_put() calls once the channels pointers are
no-longer needed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The new_connection L2CAP channel callback creates a new channel based on
the provided parent channel. The 6lowpan code was confusingly naming the
child channel "pchan" and the parent channel "chan". This patch swaps
the names.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When we're not connectable and all whitelisted (BR/EDR) devices are
connected it doesn't make sense to keep page scan enabled. This patch
adds code to check for any disconnected whitelist devices and if there
are none take the appropriate action in the hci_update_page_scan()
function to disable page scan.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Similar to our hci_update_background_scan() function we can simplify a
lot of code by creating a unified helper function for doing page scan
updates. This patch adds such a function to hci_core.c and updates all
the relevant places to use it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There are several situations where we're interested in knowing whether
we're currently in the process of powering off an adapter. This patch
adds a convenience function for the purpose and makes it public since
we'll soon need to access it from hci_event.c as well.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Pull networking updates from David Miller:
"Highlights:
1) Steady transitioning of the BPF instructure to a generic spot so
all kernel subsystems can make use of it, from Alexei Starovoitov.
2) SFC driver supports busy polling, from Alexandre Rames.
3) Take advantage of hash table in UDP multicast delivery, from David
Held.
4) Lighten locking, in particular by getting rid of the LRU lists, in
inet frag handling. From Florian Westphal.
5) Add support for various RFC6458 control messages in SCTP, from
Geir Ola Vaagland.
6) Allow to filter bridge forwarding database dumps by device, from
Jamal Hadi Salim.
7) virtio-net also now supports busy polling, from Jason Wang.
8) Some low level optimization tweaks in pktgen from Jesper Dangaard
Brouer.
9) Add support for ipv6 address generation modes, so that userland
can have some input into the process. From Jiri Pirko.
10) Consolidate common TCP connection request code in ipv4 and ipv6,
from Octavian Purdila.
11) New ARP packet logger in netfilter, from Pablo Neira Ayuso.
12) Generic resizable RCU hash table, with intial users in netlink and
nftables. From Thomas Graf.
13) Maintain a name assignment type so that userspace can see where a
network device name came from (enumerated by kernel, assigned
explicitly by userspace, etc.) From Tom Gundersen.
14) Automatic flow label generation on transmit in ipv6, from Tom
Herbert.
15) New packet timestamping facilities from Willem de Bruijn, meant to
assist in measuring latencies going into/out-of the packet
scheduler, latency from TCP data transmission to ACK, etc"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1536 commits)
cxgb4 : Disable recursive mailbox commands when enabling vi
net: reduce USB network driver config options.
tg3: Modify tg3_tso_bug() to handle multiple TX rings
amd-xgbe: Perform phy connect/disconnect at dev open/stop
amd-xgbe: Use dma_set_mask_and_coherent to set DMA mask
net: sun4i-emac: fix memory leak on bad packet
sctp: fix possible seqlock seadlock in sctp_packet_transmit()
Revert "net: phy: Set the driver when registering an MDIO bus device"
cxgb4vf: Turn off SGE RX/TX Callback Timers and interrupts in PCI shutdown routine
team: Simplify return path of team_newlink
bridge: Update outdated comment on promiscuous mode
net-timestamp: ACK timestamp for bytestreams
net-timestamp: TCP timestamping
net-timestamp: SCHED timestamp on entering packet scheduler
net-timestamp: add key to disambiguate concurrent datagrams
net-timestamp: move timestamp flags out of sk_flags
net-timestamp: extend SCM_TIMESTAMPING ancillary data struct
cxgb4i : Move stray CPL definitions to cxgb4 driver
tcp: reduce spurious retransmits due to transient SACK reneging
qlcnic: Initialize dcbnl_ops before register_netdev
...
Conflicts:
net/6lowpan/iphc.c
Minor conflicts in iphc.c were changes overlapping with some
style cleanups.
John W. Linville says:
====================
Please pull this last(?) batch of wireless change intended for the
3.17 stream...
For the NFC bits, Samuel says:
"This is a rather quiet one, we have:
- A new driver from ST Microelectronics for their NCI ST21NFCB,
including device tree support.
- p2p support for the ST21NFCA driver
- A few fixes an enhancements for the NFC digital laye"
For the Atheros bits, Kalle says:
"Michal and Janusz did some important RX aggregation fixes, basically we
were missing RX reordering altogether. The 10.1 firmware doesn't support
Ad-Hoc mode and Michal fixed ath10k so that it doesn't advertise Ad-Hoc
support with that firmware. Also he implemented a workaround for a KVM
issue."
For the Bluetooth bits, Gustavo and Johan say:
"To quote Gustavo from his previous request:
'Some last minute fixes for -next. We have a fix for a use after free in
RFCOMM, another fix to an issue with ADV_DIRECT_IND and one for ADV_IND with
auto-connection handling. Last, we added support for reading the codec and
MWS setting for controllers that support these features.'
Additionally there are fixes to LE scanning, an update to conform to the 4.1
core specification as well as fixes for tracking the page scan state. All
of these fixes are important for 3.17."
And,
"We've got:
- 6lowpan fixes/cleanups
- A couple crash fixes, one for the Marvell HCI driver and another in LE SMP.
- Fix for an incorrect connected state check
- Fix for the bondable requirement during pairing (an issue which had
crept in because of using "pairable" when in fact the actual meaning
was "bondable" (these have different meanings in Bluetooth)"
Along with those are some late-breaking hardware support patches in
brcmfmac and b43 as well as a stray ath9k patch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When we're not bondable we should never send any other SSP
authentication requirement besides one of the non-bonding ones.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This setting maps to the HCI_BONDABLE flag which tracks whether we're
bondable or not. Therefore, rename the mgmt setting and respective
command accordingly.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The new leds bit handling produces this spares warning.
CHECK net/bluetooth/hidp/core.c
net/bluetooth/hidp/core.c:156:60: warning: dubious: x | !y
Just fix it by doing an explicit x << 0 shift operation.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Both BT_CONNECTED and BT_CONFIG state mean that we have a baseband link
available. We should therefore check for either of these when pairing
and deciding whether to call hci_conn_security() directly.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
John W. Linville says:
====================
pull request: wireless-next 2014-07-25
Please pull this batch of updates intended for the 3.17 stream!
For the mac80211 bits, Johannes says:
"We have a lot of TDLS patches, among them a fix that should make hwsim
tests happy again. The rest, this time, is mostly small fixes."
For the Bluetooth bits, Gustavo says:
"Some more patches for 3.17. The most important change here is the move of
the 6lowpan code to net/6lowpan. It has been agreed with Davem that this
change will go through the bluetooth tree. The rest are mostly clean up and
fixes."
and,
"Here follows some more patches for 3.17. These are mostly fixes to what
we've sent to you before for next merge window."
For the iwlwifi bits, Emmanuel says:
"I have the usual amount of BT Coex stuff. Arik continues to work
on TDLS and Ariej contributes a few things for HS2.0. I added a few
more things to the firmware debugging infrastructure. Eran fixes a
small bug - pretty normal content."
And for the Atheros bits, Kalle says:
"For ath6kl me and Jessica added support for ar6004 hw3.0, our latest
version of ar6004.
For ath10k Janusz added a printout so that it's easier to check what
ath10k kconfig options are enabled. He also added a debugfs file to
configure maximum amsdu and ampdu values. Also we had few fixes as
usual."
On top of that is the usual large batch of various driver updates --
brcmfmac, mwifiex, the TI drivers, and wil6210 all get some action.
Rafał has also been very busy with b43 and related updates.
Also, I pulled the wireless tree into this in order to resolve a
merge conflict...
P.S. The change to fs/compat_ioctl.c reflects a name change in a
Bluetooth header file...
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
If we have entries in the whitelist we shouldn't disable page scanning
when disabling connectable mode. This patch adds the necessary check to
the Set Connectable command handler.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch fixes a typo in the hci_cc_write_scan_enable() function where
we want to clear the HCI_PSCAN flag if the SCAN_PAGE bit of the HCI
command parameter was not set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
