When socks' sk_reuseport is set, the same port and address are allowed
to be bound into these socks who have the same uid.

Note that the difference from sk_reuse is that it allows multiple socks
to listen on the same port and address.
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is a part of sk_reuseport support for sctp. It defines a helper
sctp_bind_addrs_check() to check if the bind_addrs in two socks are
matched. It will add sock_reuseport if they are completely matched,
and return err if they are partly matched, and alloc sock_reuseport
if all socks are not matched at all.

It will work until sk_reuseport support is added in
sctp_get_port_local() in the next patch.

v1->v2:
  - use 'laddr->valid && laddr2->valid' check instead as Marcelo
    pointed in sctp_bind_addrs_check().
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is a part of sk_reuseport support for sctp, and it selects a
sock by the hashkey of lport, paddr and dport by default. It will
work until sk_reuseport support is added in sctp_get_port_local()
in the next patch.

v1->v2:
  - define lport as __be16 instead of __be32 as Marcelo pointed in
    __sctp_rcv_lookup_endpoint().
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/phy/marvell.c: In function 'm88e1510_config_init':
drivers/net/phy/marvell.c:850:7: warning:
 variable 'pause' set but not used [-Wunused-but-set-variable]

It not used any more after commit 3c1bcc86 ("net: ethernet: Convert phydev
advertize and supported from u32 to link mode")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:
 "One last pull request before heading to Vancouver for LPC, here we have:

   1) Don't forget to free VSI contexts during ice driver unload, from
      Victor Raj.

   2) Don't forget napi delete calls during device remove in ice driver,
      from Dave Ertman.

   3) Don't request VLAN tag insertion of ibmvnic device when SKB
      doesn't have VLAN tags at all.

   4) IPV4 frag handling code has to accomodate the situation where two
      threads try to insert the same fragment into the hash table at the
      same time. From Eric Dumazet.

   5) Relatedly, don't flow separate on protocol ports for fragmented
      frames, also from Eric Dumazet.

   6) Memory leaks in qed driver, from Denis Bolotin.

   7) Correct valid MTU range in smsc95xx driver, from Stefan Wahren.

   8) Validate cls_flower nested policies properly, from Jakub Kicinski.

   9) Clearing of stats counters in mc88e6xxx driver doesn't retain
      important bits in the G1_STATS_OP register causing the chip to
      hang. Fix from Andrew Lunn"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (41 commits)
  act_mirred: clear skb->tstamp on redirect
  net: dsa: mv88e6xxx: Fix clearing of stats counters
  tipc: fix link re-establish failure
  net: sched: cls_flower: validate nested enc_opts_policy to avoid warning
  net: mvneta: correct typo
  flow_dissector: do not dissect l4 ports for fragments
  net: qualcomm: rmnet: Fix incorrect assignment of real_dev
  net: aquantia: allow rx checksum offload configuration
  net: aquantia: invalid checksumm offload implementation
  net: aquantia: fixed enable unicast on 32 macvlan
  net: aquantia: fix potential IOMMU fault after driver unbind
  net: aquantia: synchronized flow control between mac/phy
  net: smsc95xx: Fix MTU range
  net: stmmac: Fix RX packet size > 8191
  qed: Fix potential memory corruption
  qed: Fix SPQ entries not returned to pool in error flows
  qed: Fix blocking/unlimited SPQ entries leak
  qed: Fix memory/entry leak in qed_init_sp_request()
  inet: frags: better deal with smp races
  net: hns3: bugfix for not checking return value
  ...

Merge tag 'kbuild-fixes-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - fix build errors in binrpm-pkg and bindeb-pkg targets

 - fix false positive matches in merge_config.sh

 - fix build version mismatch in deb-pkg target

 - fix dtbs_install handling in (bin)deb-pkg target

 - revert a commit that allows setlocalversion to write to source tree

* tag 'kbuild-fixes-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  builddeb: Fix inclusion of dtbs in debian package
  Revert "scripts/setlocalversion: git: Make -dirty check more robust"
  kbuild: deb-pkg: fix too low build version number
  kconfig: merge_config: avoid false positive matches from comment lines
  kbuild: deb-pkg: fix bindeb-pkg breakage when O= is used
  kbuild: rpm-pkg: fix binrpm-pkg breakage when O= is used

Pull btrfs fixes from David Sterba:
 "Several fixes to recent release (4.19, fixes tagged for stable) and
  other fixes"

* tag 'for-4.20-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix missing delayed iputs on unmount
  Btrfs: fix data corruption due to cloning of eof block
  Btrfs: fix infinite loop on inode eviction after deduplication of eof block
  Btrfs: fix deadlock on tree root leaf when finding free extent
  btrfs: avoid link error with CONFIG_NO_AUTO_INLINE
  btrfs: tree-checker: Fix misleading group system information
  Btrfs: fix missing data checksums after a ranged fsync (msync)
  btrfs: fix pinned underflow after transaction aborted
  Btrfs: fix cur_offset in the error case for nocow

Pull ext4 fixes from Ted Ts'o:
 "A large number of ext4 bug fixes, mostly buffer and memory leaks on
  error return cleanup paths"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: missing !bh check in ext4_xattr_inode_write()
  ext4: fix buffer leak in __ext4_read_dirblock() on error path
  ext4: fix buffer leak in ext4_expand_extra_isize_ea() on error path
  ext4: fix buffer leak in ext4_xattr_move_to_block() on error path
  ext4: release bs.bh before re-using in ext4_xattr_block_find()
  ext4: fix buffer leak in ext4_xattr_get_block() on error path
  ext4: fix possible leak of s_journal_flag_rwsem in error path
  ext4: fix possible leak of sbi->s_group_desc_leak in error path
  ext4: remove unneeded brelse call in ext4_xattr_inode_update_ref()
  ext4: avoid possible double brelse() in add_new_gdb() on error path
  ext4: avoid buffer leak in ext4_orphan_add() after prior errors
  ext4: avoid buffer leak on shutdown in ext4_mark_iloc_dirty()
  ext4: fix possible inode leak in the retry loop of ext4_resize_fs()
  ext4: fix missing cleanup if ext4_alloc_flex_bg_array() fails while resizing
  ext4: add missing brelse() update_backups()'s error path
  ext4: add missing brelse() add_new_gdb_meta_bg()'s error path
  ext4: add missing brelse() in set_flexbg_block_bitmap()'s error path
  ext4: avoid potential extra brelse in setup_new_flex_group_blocks()

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes:

   - Cure the LDT remapping to user space on 5 level paging which ended
     up in the KASLR space

   - Remove LDT mapping before freeing the LDT pages

   - Make NFIT MCE handling more robust

   - Unbreak the VSMP build by removing the dependency on paravirt ops

   - Support broken PIT emulation on Microsoft hyperV

   - Don't trace vmware_sched_clock() to avoid tracer recursion

   - Remove -pipe from KBUILD CFLAGS which breaks clang and is also
     slower on GCC

   - Trivial coding style and typo fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/vmware: Do not trace vmware_sched_clock()
  x86/vsmp: Remove dependency on pv_irq_ops
  x86/ldt: Remove unused variable in map_ldt_struct()
  x86/ldt: Unmap PTEs for the slot before freeing LDT pages
  x86/mm: Move LDT remap out of KASLR region on 5-level paging
  acpi/nfit, x86/mce: Validate a MCE's address before using it
  acpi/nfit, x86/mce: Handle only uncorrectable machine checks
  x86/build: Remove -pipe from KBUILD_CFLAGS
  x86/hyper-v: Fix indentation in hv_do_fast_hypercall16()
  Documentation/x86: Fix typo in zero-page.txt
  x86/hyper-v: Enable PIT shutdown quirk
  clockevents/drivers/i8253: Add support for PIT shutdown quirk

Pull perf fixes from Thomas Gleixner:
 "A bunch of perf tooling fixes:

   - Make the Intel PT SQL viewer more robust

   - Make the Intel PT debug log more useful

   - Support weak groups in perf record so it's behaving the same way as
     perf stat

   - Display the LBR stats in callchain entries properly in perf top

   - Handle different PMu names with common prefix properlin in pert
     stat

   - Start syscall augmenting in perf trace. Preparation for
     architecture independent eBPF instrumentation of syscalls.

   - Fix build breakage in JVMTI perf lib

   - Fix arm64 tools build failure wrt smp_load_{acquire,release}"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools: Do not zero sample_id_all for group members
  perf tools: Fix undefined symbol scnprintf in libperf-jvmti.so
  perf beauty: Use SRCARCH, ARCH=x86_64 must map to "x86" to find the headers
  perf intel-pt: Add MTC and CYC timestamps to debug log
  perf intel-pt: Add more event information to debug log
  perf scripts python: exported-sql-viewer.py: Fix table find when table re-ordered
  perf scripts python: exported-sql-viewer.py: Add help window
  perf scripts python: exported-sql-viewer.py: Add Selected branches report
  perf scripts python: exported-sql-viewer.py: Fall back to /usr/local/lib/libxed.so
  perf top: Display the LBR stats in callchain entry
  perf stat: Handle different PMU names with common prefix
  perf record: Support weak groups
  perf evlist: Move perf_evsel__reset_weak_group into evlist
  perf augmented_syscalls: Start collecting pathnames in the BPF program
  perf trace: Fix setting of augmented payload when using eBPF + raw_syscalls
  perf trace: When augmenting raw_syscalls plug raw_syscalls:sys_exit too
  perf examples bpf: Start augmenting raw_syscalls:sys_{start,exit}
  tools headers barrier: Fix arm64 tools build failure wrt smp_load_{acquire,release}

Pull timer fix from Thomas Gleixner:
 "Just the removal of a redundant call into the sched deadline overrun
  check"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-cpu-timers: Remove useless call to check_dl_overrun()

Pull scheduler fixes from Thomas Gleixner:
 "Two small scheduler fixes:

   - Take hotplug lock in sched_init_smp(). Technically not really
     required, but lockdep will complain other.

   - Trivial comment fix in sched/fair"

* 'sched/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix a comment in task_numa_fault()
  sched/core: Take the hotplug lock in sched_init_smp()

Pull locking build fix from Thomas Gleixner:
 "A single fix for a build fail with CONFIG_PROFILE_ALL_BRANCHES=y in
  the qspinlock code"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/qspinlock: Fix compile error

Pull core fixes from Thomas Gleixner:
 "A couple of fixlets for the core:

   - Kernel doc function documentation fixes

   - Missing prototypes for weak watchdog functions"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  resource/docs: Complete kernel-doc style function documentation
  watchdog/core: Add missing prototypes for weak functions
  resource/docs: Fix new kernel-doc warnings

The PCI vendor id of U.S. Robotics isn't defined in pci_ids.h so far,
only ISDN driver w6692 has a private definition. Move the definition
to pci_ids.h and use it in the r8169 driver too.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Similar to 80ba92fa ("codel: add ce_threshold attribute")

After EDT adoption, it became easier to implement DCTCP-like CE marking.

In many cases, queues are not building in the network fabric but on
the hosts themselves.

If packets leaving fq missed their Earliest Departure Time by XXX usec,
we mark them with ECN CE. This gives a feedback (after one RTT) to
the sender to slow down and find better operating mode.

Example :

tc qd replace dev eth0 root fq ce_threshold 2.5ms
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

FQ pacing guarantees that paced packets queued by one flow do not
add head-of-line blocking for other flows.

After TCP GSO conversion, increasing limit_output_bytes to 1 MB is safe,
since this maps to 16 skbs at most in qdisc or device queues.
(or slightly more if some drivers lower {gso_max_segs|size})

We still can queue at most 1 ms worth of traffic (this can be scaled
by wifi drivers if they need to)

Tested:

# ethtool -c eth0 | egrep "tx-usecs:|tx-frames:" # 40 Gbit mlx4 NIC
tx-usecs: 16
tx-frames: 16
# tc qdisc replace dev eth0 root fq
# for f in {1..10};do netperf -P0 -H lpaa24,6 -o THROUGHPUT;done

Before patch:
27711
26118
27107
27377
27712
27388
27340
27117
27278
27509

After patch:
37434
36949
36658
36998
37711
37291
37605
36659
36544
37349
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: tso defer improvements

This series makes tcp_tso_should_defer() a bit smarter :

1) MSG_EOR gives a hint to TCP to not defer some skbs

2) Second patch takes into account that head tstamp
   can be in the future.

3) Third patch uses existing high resolution state variables
   to have a more precise heuristic.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

tcp_tso_should_defer() first heuristic is to not defer
if last send is "old enough".

Its current implementation uses jiffies and its low granularity.

TSO autodefer performance should not rely on kernel HZ :/

After EDT conversion, we have state variables in nanoseconds that
can allow us to properly implement the heuristic.

This patch increases TSO chunk sizes on medium rate flows,
especially when receivers do not use GRO or similar aggregation.

It also reduces bursts for HZ=100 or HZ=250 kernels, making TCP
behavior more uniform.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tcp_tso_should_defer() last step tries to check if the probable
next ACK packet is coming in less than half rtt.

Problem is that the head->tstamp might be in the future,
so we need to use signed arithmetics to avoid overflows.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Applications using MSG_EOR are giving a strong hint to TCP stack :

Subsequent sendmsg() can not append more bytes to skbs having
the EOR mark.

Do not try to TSO defer suchs skbs, there is really no hope.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bitwise operation is a little faster.
So I replace after() with using the flag FLAG_SND_UNA_ADVANCED as it is
already set before.

In addtion, there's another similar improvement in tcp_cwnd_reduction().

Cc: Joe Perches <joe@perches.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If sch_fq is used at ingress, skbs that might have been
timestamped by net_timestamp_set() if a packet capture
is requesting timestamps could be delayed by arbitrary
amount of time, since sch_fq time base is MONOTONIC.

Fix this problem by moving code from sch_netem.c to act_mirred.c.

Fixes: fb420d5d ("tcp/fq: move back to CLOCK_MONOTONIC")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mv88e6161 would sometime fail to probe with a timeout waiting for
the switch to complete an operation. This operation is supposed to
clear the statistics counters. However, due to a read/modify/write,
without the needed mask, the operation actually carried out was more
random, with invalid parameters, resulting in the switch not
responding. We need to preserve the histogram mode bits, so apply a
mask to keep them.
Reported-by: Chris Healy <Chris.Healy@zii.aero>
Fixes: 40cff8fc ("net: dsa: mv88e6xxx: Fix stats histogram mode")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrew Lunn says:

====================
net: dsa: mv88e6xxx: Support more SERDES interfacxes

Currently the SERDES interfaces for ports 9 and 10 on the mv88e6390x
are supported, allowing upto 10G. However, when unused, these SERDES
interfaces can be used by some of the lower ports for 1000Base-X.

The tricky bit here is ordering. The SERDES have to become free from
ports 9 or 10 before they can be used with lower ports. Normally, this
would happen only when these ports would be configured up, which is
too late. So at probe time, defaulting ports 9 and 10 to 1000BaseX
frees them for use with lower ports. If they are actually needed, they
will be taken back when port 9 and 10 goes up.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The 6390X family has 8 SERDES interfaces. When ports 9 and 10 are not
using all their SERDES interfaces, the unused ones can be assigned to
ports 2-8. Add support for interrupts from SERDES interfaces connected
to these lower ports.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 6390X family has 8 SERDES interfaces. This allows ports 9 and 10
to support up to 10Gbps using 4 SERDES interfaces. However, when lower
speeds are used, which need fewer SERDES interfaces, the unused SERDES
interfaces can be used by ports 2-8.

The hardware defaults to ports 9 and 10 having all 4 SERDES interfaces
assigned to them. This only gets changed when the interface is
configured after what the SFP supports has been determined, or the 10G
PHY completes auto-neg.

For hardware designs which limit ports 9 and 10 to one or two SERDES
interfaces, and place SFPs on the lower interfaces, this is too
late. Those ports with SFP should not wait until ports 9/10 are up in
order to get access to the SERDES interface. So change the default
configuration when the driver is initialised. Configure ports 9 and 10
to 1000BaseX, so they use a single SERDES interface, freeing up the
others. They can steal them back if they need them.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The X family variants support additional ports modes, for 10G
operation, which the non-X variants don't have. Add a port_set_cmode()
for non-X variants to enforce this.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move .port_set_cmode next to .port_get_cmode.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrew Lunn says:

====================
net: phy: convert advertise and supported to linkmode

This is the last part in converting phylib to make use of a linux
bitmap, not a u32, to represent links modes. This will allow support
for PHYs > 1Gbps, which need to use link modes represented by a bit >
32.

A number of MAC and PHY drivers need changes to support this. However
the previous two patchesets reduced the number somewhat, the helpers
which were introduced have been modified instead of the actual
drivers.

The follow on patches then make use of the extra bits, adding support
for more link modes.

Given how invasive this change is, i expect the build is broken for
some architectures i did not test. I will fixup the breakage as fast
as i can.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that 2.5G and 5G can be represented in phydev->advertising and
phydev->lp_advertising, add these two links modes as possible
resolutions to auto negotiation.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that PHYs and MAC can support more than 32 bit masks, add link
modes which are > 31 to the PHY settings table.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add missing markup for function parameters
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Convert phy drivers to report the link partner advertised modes using
a linkmode bitmap. This allows them to report the higher speeds which
don't fit in a u32.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are a few MAC/PHYs combinations which now support > 1Gbps. These
may need to make use of link modes with bits > 31. Thus their
supported PHY features or advertised features cannot be implemented
using the current bitmap in a u32. Convert to using a linkmode bitmap,
which can support all the currently devices link modes, and is future
proof as more modes are added.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Both states aren't used. Most likely they result from an idea that
never materialized. So remove them.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a link failure is detected locally, the link is reset, the flag
link->in_session is set to false, and a RESET_MSG with the 'stopping'
bit set is sent to the peer.

The purpose of this bit is to inform the peer that this endpoint just
is going down, and that the peer should handle the reception of this
particular RESET message as a local failure. This forces the peer to
accept another RESET or ACTIVATE message from this endpoint before it
can re-establish the link. This again is necessary to ensure that
link session numbers are properly exchanged before the link comes up
again.

If a failure is detected locally at the same time at the peer endpoint
this will do the same, which is also a correct behavior.

However, when receiving such messages, the endpoints will not
distinguish between 'stopping' RESETs and ordinary ones when it comes
to updating session numbers. Both endpoints will copy the received
session number and set their 'in_session' flags to true at the
reception, while they are still expecting another RESET from the
peer before they can go ahead and re-establish. This is contradictory,
since, after applying the validation check referred to below, the
'in_session' flag will cause rejection of all such messages, and the
link will never come up again.

We now fix this by not only handling received RESET/STOPPING messages
as a local failure, but also by omitting to set a new session number
and the 'in_session' flag in such cases.

Fixes: 7ea817f4 ("tipc: check session number before accepting link protocol messages")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The snmp_counter.rst explains the meanings of snmp counters. It also
provides a set of experiments (only 1 for this initial patch),
combines the experiments' resutls and the snmp counters'
meanings. This is an initial path, only explains a part of IP/ICMP
counters and provide a simple ping test.
Signed-off-by: yupeng <yupeng0921@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>