Use spin_lock and spin_unlock in interrupt context.

The ndo_start_xmit would not be called in interrupt context, so
replace the relative spin_lock_irqsave and spin_unlock_irqrestore
with spin_lock_bh and spin_unlock_bh.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates

This series contains updates to i40e and i40evf.

Most notable are:
Joseph completes the implementation of the ethtool ntuple rule
management interface by adding the get, update and delete interface
reset.

Akeem provides a fix to prevent a possible overflow due to multiplication
of number and size by using kzalloc, so use kcalloc.

Jesse provides an implementation for skb_set_hash() and adds the L4 type
return when we know it is an L4 hash.  He also adds a counter to
statistics for Tx timeouts to help users.  Lastly he provides a change
to stay away from the cache line where the done bit may be getting
written back for the transmit ring since the hardware may be writing the
whole cache line for a partial update.

Shannon cleans up code comments.

Anjali removes a firmware workaround for newer firmware since the number
of MSIx vectors are being reported correctly.

v2:
 -  dropped patch 01 of the series based on feedback from the author
    Joe Perches and Shannon Nelson.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

David Howells says:

====================
net-next: AF_RXRPC fixes and development

Here are some AF_RXRPC fixes:

 (1) Fix to remove incorrect checksum calculation made during recvmsg().  It's
     unnecessary to try to do this there since we check the checksum before
     reading the RxRPC header from the packet.

 (2) Fix to prevent the sending of an ABORT packet in response to another
     ABORT packet and inducing a storm.

 (3) Fix UDP MTU calculation from parsing ICMP_FRAG_NEEDED packets where we
     don't handle the ICMP packet not specifying an MTU size.

And development patches:

 (4) Add sysctls for configuring RxRPC parameters, specifically various delays
     pertaining to ACK generation, the time before we resend a packet for
     which we don't receive an ACK, the maximum time a call is permitted to
     live and the amount of time transport, connection and dead call
     information is cached.

 (5) Improve ACK packet production by adjusting the handling of ACK_REQUESTED
     packets, ignoring the MORE_PACKETS flag, delaying the production of
     otherwise immediate ACK_IDLE packets and delaying all ACK_IDLE production
     (barring the call termination) to half a second.

 (6) Add more sysctl parameters to expose the Rx window size, the maximum
     packet size that we're willing to receive and the number of jumbo rxrpc
     packets we're willing to handle in a single UDP packet.

 (7) Request ACKs on alternate DATA packets so that the other side doesn't
     wait till we fill up the Tx window.

 (8) Use a RCU hash table to look up the rxrpc_call for an incoming packet
     rather than stepping through a hierarchy involving several spinlocks.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Zoltan Kiss says:

====================
xen-netback: TX grant mapping with SKBTX_DEV_ZEROCOPY instead of copy

A long known problem of the upstream netback implementation that on the TX
path (from guest to Dom0) it copies the whole packet from guest memory into
Dom0. That simply became a bottleneck with 10Gb NICs, and generally it's a
huge perfomance penalty. The classic kernel version of netback used grant
mapping, and to get notified when the page can be unmapped, it used page
destructors. Unfortunately that destructor is not an upstreamable solution.
Ian Campbell's skb fragment destructor patch series [1] tried to solve this
problem, however it seems to be very invasive on the network stack's code,
and therefore haven't progressed very well.
This patch series use SKBTX_DEV_ZEROCOPY flags to tell the stack it needs to
know when the skb is freed up. That is the way KVM solved the same problem,
and based on my initial tests it can do the same for us. Avoiding the extra
copy boosted up TX throughput from 6.8 Gbps to 7.9 (I used a slower AMD
Interlagos box, both Dom0 and guest on upstream kernel, on the same NUMA node,
running iperf 2.0.5, and the remote end was a bare metal box on the same 10Gb
switch)
Based on my investigations the packet get only copied if it is delivered to
Dom0 IP stack through deliver_skb, which is due to this [2] patch. This affects
DomU->Dom0 IP traffic and when Dom0 does routing/NAT for the guest. That's a bit
unfortunate, but luckily it doesn't cause a major regression for this usecase.
In the future we should try to eliminate that copy somehow.
There are a few spinoff tasks which will be addressed in separate patches:
- grant copy the header directly instead of map and memcpy. This should help
  us avoiding TLB flushing
- use something else than ballooned pages
- fix grant map to use page->index properly
I've tried to broke it down to smaller patches, with mixed results, so I
welcome suggestions on that part as well:
1: Use skb->cb to store pending_idx
2: Some refactoring
3: Change RX path for mapped SKB fragments (moved here to keep bisectability,
review it after #4)
4: Introduce TX grant mapping
5: Remove old TX grant copy definitons and fix indentations
6: Add stat counters for zerocopy
7: Handle guests with too many frags
8: Timeout packets in RX path
9: Aggregate TX unmap operations

v2: I've fixed some smaller things, see the individual patches. I've added a
few new stat counters, and handling the important use case when an older guest
sends lots of slots. Instead of delayed copy now we timeout packets on the RX
path, based on the assumption that otherwise packets should get stucked
anywhere else. Finally some unmap batching to avoid too much TLB flush

v3: Apart from fixing a few things mentioned in responses the important change
is the use the hypercall directly for grant [un]mapping, therefore we can
avoid m2p override.

v4: Now we are using a new grant mapping API to avoid m2p_override. The RX queue
timeout logic changed also.

v5: Only minor fixes based on Wei's comments

v6: Important bugfixes for xenvif_poll exit path and zerocopy callback, see
first 2 patches. Also rework of handling packets with too many slots, and
reorder the series a bit.

v7: Small fixes in comments/log messages/error paths, and merging the frag
overflow stats patch into its parent.

[1] http://lwn.net/Articles/491522/
[2] https://lkml.org/lkml/2012/7/20/363
====================
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Unmapping causes TLB flushing, therefore we should make it in the largest
possible batches. However we shouldn't starve the guest for too long. So if
the guest has space for at least two big packets and we don't have at least a
quarter ring to unmap, delay it for at most 1 milisec.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A malicious or buggy guest can leave its queue filled indefinitely, in which
case qdisc start to queue packets for that VIF. If those packets came from an
another guest, it can block its slots and prevent shutdown. To avoid that, we
make sure the queue is drained in every 10 seconds.
The QDisc queue in worst case takes 3 round to flush usually.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Xen network protocol had implicit dependency on MAX_SKB_FRAGS. Netback has to
handle guests sending up to XEN_NETBK_LEGACY_SLOTS_MAX slots. To achieve that:
- create a new skb
- map the leftover slots to its frags (no linear buffer here!)
- chain it to the previous through skb_shinfo(skb)->frag_list
- map them
- copy and coalesce the frags into a brand new one and send it to the stack
- unmap the 2 old skb's pages

It's also introduces new stat counters, which help determine how often the guest
sends a packet with more than MAX_SKB_FRAGS frags.

NOTE: if bisect brought you here, you should apply the series up until
"xen-netback: Timeout packets in RX path", otherwise malicious guests can block
other guests by not releasing their sent packets.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

These counters help determine how often the buffers had to be copied. Also
they help find out if packets are leaked, as if "sent != success + fail",
there are probably packets never freed up properly.

NOTE: if bisect brought you here, you should apply the series up until
"xen-netback: Timeout packets in RX path", otherwise Windows guests can't work
properly and malicious guests can block other guests by not releasing their sent
packets.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

These became obsolete with grant mapping. I've left intentionally the
indentations in this way, to improve readability of previous patches.

NOTE: if bisect brought you here, you should apply the series up until
"xen-netback: Timeout packets in RX path", otherwise Windows guests can't work
properly and malicious guests can block other guests by not releasing their sent
packets.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch introduces grant mapping on netback TX path. It replaces grant copy
operations, ditching grant copy coalescing along the way. Another solution for
copy coalescing is introduced in "xen-netback: Handle guests with too many
frags", older guests and Windows can broke before that patch applies.
There is a callback (xenvif_zerocopy_callback) from core stack to release the
slots back to the guests when kfree_skb or skb_orphan_frags called. It feeds a
separate dealloc thread, as scheduling NAPI instance from there is inefficient,
therefore we can't do dealloc from the instance.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RX path need to know if the SKB fragments are stored on pages from another
domain.
Logically this patch should be after introducing the grant mapping itself, as
it makes sense only after that. But to keep bisectability, I moved it here. It
shouldn't change any functionality here. xenvif_zerocopy_callback and
ubuf_to_vif are just stubs here, they will be introduced properly later on.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch contains a few bits of refactoring before introducing the grant
mapping changes:
- introducing xenvif_tx_pending_slots_available(), as this is used several
  times, and will be used more often
- rename the thread to vifX.Y-guest-rx, to signify it does RX work from the
  guest point of view
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Storing the pending_idx at the first byte of the linear buffer never looked
good, skb->cb is a more proper place for this. It also prevents the header to
be directly grant copied there, and we don't have the pending_idx after we
copied the header here, so it's time to change it.
It also introduces helpers for the RX side
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is no reason to orphan skb in l2tp.

This breaks things like per socket memory limits, TCP Small queues...

Fix this before more people copy/paste it.

This is very similar to commit 8f646c92
("vxlan: keep original skb ownership")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Usage of skb->tstamp should remain private to TCP stack
(only set on packets on write queue, not on cloned ones)

Otherwise, packets given to loopback interface with a non null tstamp
can confuse netif_rx() / net_timestamp_check()

Other possibility would be to clear tstamp in loopback_xmit(),
as done in skb_scrub_packet()

Fixes: 740b0f18 ("tcp: switch rtt estimations to usec resolution")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bump i40e to 0.3.34 and i40evf to 0.9.14.

Change-ID: I6b3fb8ccf55b128d2baa4bdc20d3911ec81d4a5b
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

We need to make sure that we stay away from the cache line
where the DD bit (done) may be getting written back for
the transmit ring since the hardware may be writing the
whole cache line for a partial update.

Change-ID: Id0b6dfc01f654def6a2a021af185803be1915d7e
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The driver needs to use the format that the current NVM
uses when printing the version of the NVM.  It should remain
this way from now on forward.

The driver was reporting when firmware was less than
an expected version number, but this is not a requirement
for the product and we print the firmware number at
init and in ethtool -i output.  Just remove the print.

Change-ID: Ide0b856cd454ebf867610ef9a0d639bb358a4a60
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch fixes the following static checker warning:

  drivers/net/ethernet/intel/i40e/i40e_dcb.c:342
  i40e_lldp_to_dcb_config() warn: 'tlv' can't be NULL.

Exit criteria from the while loop is encountering LLDP END
LV or if the TLV length goes beyond the buffer length.

Change-ID: I7548b16db90230ec2ba0fa791b0343ca8b7dd5bb
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Neerav Parikh <Neerav.Parikh@intel.com>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Kevin Scott <kevin.c.scott@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Tested-By: Jack Morgan<jack.morgan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Remove a redundant filter addition to stop FW complaints about a redundant
filter removal.

Change-ID: I22bef6b682bd8d43432557e6e2b3e73ffb27b985
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The ethtool -S statistics should have a counter for
tx timeouts in order to better help inform the masses.

Change-ID: Ice4b20ed4a151509f366719ab105be49c9e7b2b4
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The Number of MSIX vectors being reported is correct and hence
we need a check to do the right thing for FWs before and after.

Change-ID: I50902d1c848adcb960ea49ac73f7865ca871a1c3
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Lots of trivial changes to remove double spaces in function headers,
unnecessary periods in short comments, and adjust the English usage here
and there.

No actual code was harmed in the making of this patch.

Change-ID: I6e756c500756945e81a61ffb10221753eb7923ea
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Kevin Scott <kevin.c.scott@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Original comment from Tom Herbert <therbert@google.com>

   Drivers should call skb_set_hash to set the hash and its type
   in an skbuff.

This patch builds upon Tom's original implementation and adds
the L4 type return when we know it is an L4 hash.
This requires use of the ptype decoder ring, so enable it.

Change-ID: I2f9fa86d1a6add58cff13386f7f4238b1abcc468
CC: Tom Herbert <therbert@google.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

To prevent the possibility of overflow due multiplication of number and size
use kcalloc instead of kzalloc.

Change-ID: Ibe4d81ed7d9738d3bbe66ee4844ff9be817e8080
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch completes implementation of the ethtool ntuple
rule management interface.  It adds the get, update and delete
interface reset.

Change-ID: Ida7f481d9ee4e405ed91340b858eabb18a52fdb5
Signed-off-by: Joseph Gasparakis <joseph.gasparakis@intel.com>
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Set netdev->hw_features to enable the ndo_set_features netdev op.

Change-Id: I5a086fbfa5a089de5adba2800c4d0b3a73747b11
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This is a fixup patch to resolve issues with const from my earlier patch.
Make all the setter functions use const on input parameter.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

htb_dump() and htb_dump_class() do not strictly need to acquire
qdisc lock to fetch qdisc and/or class parameters.

We hold RTNL and no changes can occur.

This reduces by 50% qdisc lock pressure while doing tc qdisc|class dump
operations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexander Aring says:

====================
6lowpan: header cleanup

this patch series fix a missing include of 6LoWPAN header and move it
into the include/net directory. Since we did some code sharing with
bluetooth 6LoWPAN the header turns into a generic header for 6LoWPAN.
Instead to use a relative path in bluetooth 6LoWPAN we can now use
include <net/6lowpan.h>.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This header is used by bluetooth and ieee802154 branch. This patch
move this header to the include/net directory to avoid a use of a
relative path in include.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 6lowpan.h file contains some static inline function which use
internal ipv6 api structs. Add a include of ipv6.h to be sure that it's
known before.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

v2: remove unnecessary braces from all 'loopback' if-blocks (thx Sergei)

Cc: sathya.perla@emulex.com
Cc: subbu.seetharaman@emulex.com
Cc: ajit.khaparde@emulex.com
Cc: sergei.shtylyov@cogentembedded.com
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Ajit Khaparde <ajit.khaparde@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix static error introduced by commit:
b97b33a3 [645/653] net/mlx4_en: Verify
mlx4_en module parameters

sparse warnings:
drivers/net/ethernet/mellanox/mlx4/en_main.c:335:6: sparse: symbol
'mlx4_en_verify_params' was not declared. Should it be static?

CC: netdev@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make local functions static (ie. only used in bond_options.c)
Make bond options parsing tables constant.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

These functions are defined but no longer used.
Compile tested only.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Can be invoked from non-BH context.

Based upon a patch by Eric Dumazet.

Fixes: f19c29e3 ("tcp: snmp stats for Fast Open, SYN rtx, and data pkts")
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently we're using GFP_KERNEL, however there are some path(s) where we
can hold some spinlocks, specifically bond->curr_slave_lock:

[    4.722916] BUG: sleeping function called from invalid context at mm/slub.c:965
[    4.724438] in_atomic(): 1, irqs_disabled(): 0, pid: 940, name: ifup-eth
[    4.726034] 5 locks held by ifup-eth/940:
...snip...
[    4.734646]  #4:  (&bond->curr_slave_lock){+...+.}, at: [<ffffffffa00badc6>] bond_enslave+0xda6/0xdd0 [bonding]
...snip...
[    4.759081]  [<ffffffffa00b6f11>] bond_change_active_slave+0x191/0x3b0 [bonding]
[    4.760917]  [<ffffffffa00b7227>] bond_select_active_slave+0xf7/0x1d0 [bonding]
[    4.762751]  [<ffffffffa00badce>] bond_enslave+0xdae/0xdd0 [bonding]
...snip...

As it's out of hot path and is a really rare event - change the gfp_t flags
to GFP_ATOMIC to avoid sleeping under spinlock.

v2: convert new notify calls to GFP_ATOMIC.

CC: Thomas Glanzmann <thomas@glanzmann.de>
CC: Ding Tianhong <dingtianhong@huawei.com>
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit e688a604 ("net: introduce DST_NOPEER dst flag") introduced
DST_NOPEER because because of crashes in ipv6_select_ident called from
udp6_ufo_fragment.

Since commit 916e4cf4 ("ipv6: reuse ip6_frag_id from
ip6_ufo_append_data") we don't call ipv6_select_ident any more from
ip6_ufo_append_data, thus this flag lost its purpose and can be removed.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hayes Wang says:

====================
r8152: cleanups

Deal with some empty lines and spaces, replace some tp->netdev with netdev,
and remove the unnecessary function.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>