A cleanup patch in linux-3.18 moved around some code in the ath9k
driver and left some code to be indented in a misleading way,
made worse by the addition of some new code for p2p mode, as
discovered by a new gcc-6 warning:

drivers/net/wireless/ath/ath9k/init.c: In function 'ath9k_set_hw_capab':
drivers/net/wireless/ath/ath9k/init.c:851:4: warning: statement is indented as if it were guarded by... [-Wmisleading-indentation]
    hw->wiphy->iface_combinations = if_comb;
    ^~
drivers/net/wireless/ath/ath9k/init.c:847:3: note: ...this 'if' clause, but it is not
   if (ath9k_is_chanctx_enabled())
   ^~

The code is in fact correct, but the indentation is not, so I'm
reformatting it as it should have been after the original cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 499afacc ("ath9k: Isolate ath9k_use_chanctx module parameter")
Fixes: eb61f9f6 ("ath9k: advertise p2p dev support when chanctx")
Signed-off-by: David S. Miller <davem@davemloft.net>

Code that was added back in 2.6.38 has an obvious overflow
when accessing a static array, and at the time it was added
only a code comment was put in front of it as a reminder
to have it reviewed properly.

This has not happened, but gcc-6 now points to the specific
overflow:

drivers/net/wireless/ath/ath9k/eeprom.c: In function 'ath9k_hw_get_gain_boundaries_pdadcs':
drivers/net/wireless/ath/ath9k/eeprom.c:483:44: error: array subscript is above array bounds [-Werror=array-bounds]
     maxPwrT4[i] = data_9287[idxL].pwrPdg[i][4];
                   ~~~~~~~~~~~~~~~~~~~~~~~~~^~~

It turns out that the correct array length exists in the local
'intercepts' variable of this function, so we can just use that
instead of hardcoding '4', so this patch changes all three
instances to use that variable. The other two instances were
already correct, but it's more consistent this way.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 940cd2c1 ("ath9k_hw: merge the ar9287 version of ath9k_hw_get_gain_boundaries_pdadcs")
Signed-off-by: David S. Miller <davem@davemloft.net>

gcc-6 finds an out of bounds access in the fst_add_one function
when calculating the end of the mmio area:

drivers/net/wan/farsync.c: In function 'fst_add_one':
drivers/net/wan/farsync.c:418:53: error: index 2 denotes an offset greater than size of 'u8[2][8192] {aka unsigned char[2][8192]}' [-Werror=array-bounds]
 #define BUF_OFFSET(X)   (BFM_BASE + offsetof(struct buf_window, X))
                                                     ^
include/linux/compiler-gcc.h:158:21: note: in definition of macro '__compiler_offsetof'
  __builtin_offsetof(a, b)
                     ^
drivers/net/wan/farsync.c:418:37: note: in expansion of macro 'offsetof'
 #define BUF_OFFSET(X)   (BFM_BASE + offsetof(struct buf_window, X))
                                     ^~~~~~~~
drivers/net/wan/farsync.c:2519:36: note: in expansion of macro 'BUF_OFFSET'
                                  + BUF_OFFSET ( txBuffer[i][NUM_TX_BUFFER][0]);
                                    ^~~~~~~~~~

The warning is correct, but not critical because this appears
to be a write-only variable that is set by each WAN driver but
never accessed afterwards.

I'm taking the minimal fix here, using the correct pointer by
pointing 'mem_end' to the last byte inside of the register area
as all other WAN drivers do, rather than the first byte outside of
it. An alternative would be to just remove the mem_end member
entirely.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The implementation of QP paravirtualization back in linux-3.7 included
some code that looks very dubious, and gcc-6 has grown smart enough
to warn about it:

drivers/net/ethernet/mellanox/mlx4/resource_tracker.c: In function 'verify_qp_parameters':
drivers/net/ethernet/mellanox/mlx4/resource_tracker.c:3154:5: error: statement is indented as if it were guarded by... [-Werror=misleading-indentation]
     if (optpar & MLX4_QP_OPTPAR_ALT_ADDR_PATH) {
     ^~
drivers/net/ethernet/mellanox/mlx4/resource_tracker.c:3144:4: note: ...this 'if' clause, but it is not
    if (slave != mlx4_master_func_num(dev))

>From looking at the context, I'm reasonably sure that the indentation
is correct but that it should have contained curly braces from the
start, as the update_gid() function in the same patch correctly does.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 54679e14 ("mlx4: Implement QP paravirtualization and maintain phys_pkey_cache for smp_snoop")
Signed-off-by: David S. Miller <davem@davemloft.net>

The device_reset() function may fail, so we have to check
its return value, e.g. to make deferred probing work correctly.
gcc warns about it because of the warn_unused_result attribute:

drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function 'mtk_probe':
drivers/net/ethernet/mediatek/mtk_eth_soc.c:1679:2: error: ignoring return value of 'device_reset', declared with attribute warn_unused_result [-Werror=unused-result]

This adds the trivial error check to propagate the return value
to the generic platform device probe code.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Device drivers should not mess with the DMA mask directly,
but instead call dma_set_mask() etc if needed.

In case of the mtk_eth_soc driver, the mask already gets set
correctly when the device is created, and setting it again
is against the documented API.

This removes the incorrect setting.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

dma_alloc_coherent() expects a dma_addr_t pointer as its argument,
not an 'unsigned int', and gcc correctly warns about broken
code in the mtk_init_fq_dma function:

drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function 'mtk_init_fq_dma':
drivers/net/ethernet/mediatek/mtk_eth_soc.c:463:13: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]

This changes the type of the local variable to dma_addr_t.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The syzkaller fuzzer hit the following use-after-free:

  Call Trace:
   [<ffffffff8175ea0e>] __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:295
   [<ffffffff851cc31a>] __sys_recvmmsg+0x6fa/0x7f0 net/socket.c:2261
   [<     inline     >] SYSC_recvmmsg net/socket.c:2281
   [<ffffffff851cc57f>] SyS_recvmmsg+0x16f/0x180 net/socket.c:2270
   [<ffffffff86332bb6>] entry_SYSCALL_64_fastpath+0x16/0x7a
  arch/x86/entry/entry_64.S:185

And, as Dmitry rightly assessed, that is because we can drop the
reference and then touch it when the underlying recvmsg calls return
some packets and then hit an error, which will make recvmmsg to set
sock->sk->sk_err, oops, fix it.
Reported-and-Tested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Fixes: a2e27255 ("net: Introduce recvmmsg socket syscall")
http://lkml.kernel.org/r/20160122211644.GC2470@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sunil Goutham says:

====================
net: thunderx: Performance enhancement changes

Below patches attempts to improve performance by reducing
no of atomic operations while allocating new receive buffers
and reducing cache misses by adjusting nicvf structure elements.

Changes from v1:
 No changes, resubmitting a fresh as per David's suggestion.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Adjusted nicvf structure such that all elements used in hot
path like napi, xmit e.t.c fall into same cache line. This reduced
no of cache misses and resulted in ~2% increase in no of packets
handled on a core.

Also modified elements with :1 notation to boolean, to be
consistent with other element definitions.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of calling get_page() for every receive buffer carved out
of page, set page's usage count at the end, to reduce no of atomic
calls.
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Expand headroom further in order to be able to fit the larger IPv6
header. Prior to this patch this caused a skb under panic for certain
tipc packets when using IPv6 UDP bearer(s).
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Gregory CLEMENT says:

====================
API set for HW Buffer management

This is the sixth version of the API set for HW Buffer management (that was
initially submitted here:
http://thread.gmane.org/gmane.linux.kernel/2125152).

This version is just a rebasing onto the last net-next. I also added
the Tested-by flag from Sebastian Careba : "The patch set applies
successfully and it works well, no more Samba issues any longer".

For the record in the previous versions I made the following changes:
v4 -> v5:
- Add a field with the size of the buffer of the pool was added. It
  then allow to fix some misused size in the mvneta_bm code when using
  the new framework.

- Add a new patch from Marcin for sram allowing to require
  non-bufferable access to the memory. It was needed for the hardware
  buffer management of the mvneta.

- Fix the build issue notified by the 0-day builder when building the
  drivers as module.

v3 -> v4
- Fix build issue when HWBM is not selected

v2 -> v3
- Make a HWBM and a SWBM version of the mvneta_rx() function in order
  to reduce the the conditional code. Kept a condition inside the
  mvneta_poll because specializing this function would have means
  duplicating 95% of the code.

- Put back the register_netdev() call at the end of the mvneta_probe()
  function. In order to have a unique ID for each port, just used a
  global variable in the driver.

- Added a fix from Marcin in the "net: mvneta: bm: add support for
  hardware buffer management" patch: "when dropping packets, only
  buffer pointers passed from BM to descriptors have to be returned to
  the pool. In submitted version after closing the port and
  mvneta_rxq_deinit(), it was very likely that a lot of fake buffers
  are added to the pool, because all descriptors took part in
  iteration."

- Removed the select MVNETA_BM from the Kconfig, it will let the user
  the choice to use not use it if they want.

v1 -> v2
- The hardware buffer management helpers are no more built by default
  and now depend on a hidden config symbol which has to be selected
  by the driver if needed
- The hwbm_pool_refill() and hwbm_pool_add() now receive a gfp_t as
  argument allowing the caller to specify the flag it needs.
- buf_num is now tested to ensure there is no wrapping
- A spinlock has been added to protect the hwbm_pool_add() function in
  SMP or irq context.
- used pr_warn instead of pr_debug in case of errors.
- fixed the mvneta implementation by returning the buffer to the pool
  at various place instead of ignoring it.
- Squashed "bus: mvenus-mbus: Fix size test for
   mvebu_mbus_get_dram_win_info" into bus: mvebu-mbus: provide api for
   obtaining IO and DRAM window information.
- Added my signed-otf-by on all the patches as submitter of the series.
- Renamed the dts patches with the pattern "ARM: dts: platform:"
- Removed the patch "ARM: mvebu: enable SRAM support in
  mvebu_v7_defconfig" of this series and already applied it
- Modified the order of the patches.

In order to ease the test the branch mvneta-BM-framework-v6 is
available at git@github.com:MISL-EBU-System-SW/mainline-public.git.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that the hardware buffer management framework had been introduced,
let's use it.
Tested-by: Sebastian Careba <nitroshift@yahoo.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This basic implementation allows to share code between driver using
hardware buffer management. As the code is hardware agnostic, there is
few helpers, most of the optimization brought by the an HW BM has to be
done at driver level.
Tested-by: Sebastian Careba <nitroshift@yahoo.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Buffer manager (BM) is a dedicated hardware unit that can be used by all
ethernet ports of Armada XP and 38x SoC's. It allows to offload CPU on RX
path by sparing DRAM access on refilling buffer pool, hardware-based
filling of descriptor ring data and better memory utilization due to HW
arbitration for using 'short' pools for small packets.

Tests performed with A388 SoC working as a network bridge between two
packet generators showed increase of maximum processed 64B packets by
~20k (~555k packets with BM enabled vs ~535 packets without BM). Also
when pushing 1500B-packets with a line rate achieved, CPU load decreased
from around 25% without BM to 20% with BM.

BM comprise up to 4 buffer pointers' (BP) rings kept in DRAM, which
are called external BP pools - BPPE. Allocating and releasing buffer
pointers (BP) to/from BPPE is performed indirectly by write/read access
to a dedicated internal SRAM, where internal BP pools (BPPI) are placed.
BM hardware controls status of BPPE automatically, as well as assigning
proper buffers to RX descriptors. For more details please refer to
Functional Specification of Armada XP or 38x SoC.

In order to enable support for a separate hardware block, common for all
ports, a new driver has to be implemented ('mvneta_bm'). It provides
initialization sequence of address space, clocks, registers, SRAM,
empty pools' structures and also obtaining optional configuration
from DT (please refer to device tree binding documentation). mvneta_bm
exposes also a necessary API to mvneta driver, as well as a dedicated
structure with BM information (bm_priv), whose presence is used as a
flag notifying of BM usage by port. It has to be ensured that mvneta_bm
probe is executed prior to the ones in ports' driver. In case BM is not
used or its probe fails, mvneta falls back to use software buffer
management.

A sequence executed in mvneta_probe function is modified in order to have
an access to needed resources before possible port's BM initialization is
done. According to port-pools mapping provided by DT appropriate registers
are configured and the buffer pools are filled. RX path is modified
accordingly. Becaues the hardware allows a wide variety of configuration
options, following assumptions are made:
* using BM mechanisms can be selectively disabled/enabled basing
  on DT configuration among the ports
* 'long' pool's single buffer size is tied to port's MTU
* using 'long' pool by port is obligatory and it cannot be shared
* using 'short' pool for smaller packets is optional
* one 'short' pool can be shared among all ports

This commit enables hardware buffer management operation cooperating with
existing mvneta driver. New device tree binding documentation is added and
the one of mvneta is updated accordingly.

[gregory.clement@free-electrons.com: removed the suspend/resume part]
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This commit enables finding appropriate mbus window and obtaining its
target id and attribute for given physical address in two separate
routines, both for IO and DRAM windows. This functionality
is needed for Armada XP/38x Network Controller's Buffer Manager and
PnC configuration.

[gregory.clement@free-electrons.com: Fix size test for
mvebu_mbus_get_dram_win_info]
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
[DRAM window information reference in LKv3.10]
Signed-off-by: Evan Wang <xswang@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow Openblock AX3 using hardware buffer management with mvneta.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since mvneta driver supports using hardware buffer management (BM), in
order to use it, board files have to be adjusted accordingly. This commit
enables BM on AXP-DB and AXP-GP in same manner - because number of ports
on those boards is the same as number of possible pools, each port is
supposed to use single pool for all kind of packets.

Moreover appropriate entry is added to 'soc' node ranges, as well as "okay"
status for 'bm' and 'bm-bppi' (internal SRAM) nodes.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Armada XP network controller supports hardware buffer management (BM).
Since it is now enabled in mvneta driver, appropriate nodes can be added
to armada-xp.dtsi - for the actual common BM unit (bm@c0000) and its
internal SRAM (bm-bppi), which is used for indirect access to buffer
pointer ring residing in DRAM.

Pools - ports mapping, bm-bppi entry in 'soc' node's ranges and optional
parameters are supposed to be set in board files.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since mvneta driver supports using hardware buffer management (BM), in
order to use it, board files have to be adjusted accordingly. This commit
enables BM on:
* A385-DB-AP - each port has its own pool for long and common pool for
short packets,
* A388-ClearFog - same as above,
* A388-DB - to each port unique 'short' and 'long' pools are mapped,
* A388-GP - same as above.

Moreover appropriate entry is added to 'soc' node ranges, as well as "okay"
status for 'bm' and 'bm-bppi' (internal SRAM) nodes.

[gregory.clement@free-electrons.com: add suppport for the ClearFog board]
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Armada 38x network controller supports hardware buffer management (BM).
Since it is now enabled in mvneta driver, appropriate nodes can be added
to armada-38x.dtsi - for the actual common BM unit (bm@c8000) and its
internal SRAM (bm-bppi), which is used for indirect access to buffer
pointer ring residing in DRAM.

Pools - ports mapping, bm-bppi entry in 'soc' node's ranges and optional
parameters are supposed to be set in board files.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some SRAM users may require non-bufferable access to the memory, which is
impossible, because devm_ioremap_wc() is used for setting sram->virt_base.

This commit adds optional flag 'no-memory-wc', which allow to choose remap
method, using DT property. Documentation is updated accordingly.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'wireless-drivers-next-for-davem-2016-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next

Kalle Valo says:

====================
wireless-drivers patches for 4.6

Major changes:

rtl8xxxu

* add 8723bu support

wl18xx

* add radar_debug_mode debugfs file for DFS testing
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexander Duyck says:

====================
Fix differences between IPv4 and IPv6 TCP/UDP checksum calculation

This patch series is meant to address the differences that exist between
IPv4 and IPv6 in terms of checksum calculation.  Specifically the IPv6
function csum_ipv6_magic treated length as a value that could be greater
than 64K, while csum_tcpudp_magic was truncating the length at 16 bits.
After looking over the code and giving it some thought I decided it would
be best to update the IPv4 function so that it worked the same way the IPv6
one did.  This allows us to get the same results given the same inputs for
both functions.  As a result we can use the same processes to reverse the
calculation in the event we need to do something like remove the length of
the pseudo-header checksum.

I also took the opportunity to standardize things so that the parameters
for these functions all use the correct types.  IPv4 addresses are __be32,
length should always be __u32, and protocol is a __u8.

With this change in place it corrects an issue with UDP tunnels in which we
were getting a checksum that was off by 1 when performing fragmentation on
inner UDP packets.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

It is possible for tunnels to end up generating IP or IPv6 datagrams that
are larger than 64K and expecting to be segmented.  As such we need to deal
with length values greater than 64K.  In order to accommodate this we need
to update the code to work with a 32b length value instead of a 16b one.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch updates csum_ipv6_magic so that it correctly recognizes that
protocol is a unsigned 8 bit value.

This will allow us to better understand what limitations may or may not be
present in how we handle the data.  For example there are a number of
places that call htonl on the protocol value.  This is likely not necessary
and can be replaced with a multiplication by ntohl(1) which will be
converted to a shift by the compiler.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch updates all instances of csum_tcpudp_magic and
csum_tcpudp_nofold to reflect the types that are usually used as the source
inputs.  For example the protocol field is populated based on nexthdr which
is actually an unsigned 8 bit value.  The length is usually populated based
on skb->len which is an unsigned integer.

This addresses an issue in which the IPv6 function csum_ipv6_magic was
generating a checksum using the full 32b of skb->len while
csum_tcpudp_magic was only using the lower 16 bits.  As a result we could
run into issues when attempting to adjust the checksum as there was no
protocol agnostic way to update it.

With this change the value is still truncated as many architectures use
"(len + proto) << 8", however this truncation only occurs for values
greater than 16776960 in length and as such is unlikely to occur as we stop
the inner headers at ~64K in size.

I did have to make a few minor changes in the arm, mn10300, nios2, and
score versions of the function in order to support these changes as they
were either using things such as an OR to combine the protocol and length,
or were using ntohs to convert the length which would have truncated the
value.

I also updated a few spots in terms of whitespace and type differences for
the addresses.  Most of this was just to make sure all of the definitions
were in sync going forward.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When an inetdev is destroyed, every address assigned to the interface
is removed.  And in this scenerio we do two pointless things which can
be very expensive if the number of assigned interfaces is large:

1) Address promotion.  We are deleting all addresses, so there is no
   point in doing this.

2) A full nf conntrack table purge for every address.  We only need to
   do this once, as is already caught by the existing
   masq_dev_notifier so masq_inet_event() can skip this.
Reported-by: Solar Designer <solar@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>

Samuel Ortiz says:

====================
NFC 4.6 pull request

This is a very small one this time, with only 5 patches.
There are a couple of big items that could not be merged/finished
on time.

We have:

- 2 LLCP fixes for a race and a potential OOM.
- 2 cleanups for the pn544 and microread drivers.
- 1 Maintainer addition for the s3fwrn5 driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Sabrina Dubroca says:

====================
MACsec IEEE 802.1AE implementation

MACsec (IEEE 802.1AE [0]) is a protocol that provides security for
wired ethernet LANs.  MACsec offers two protection modes:
authentication only, or authenticated encryption.

MACsec defines "secure channels" that allow transmission from one node
to one or more others.  Communication on a channel is done over a
succession of "secure associations", that each use a specific key.
Secure associations are identified by their "association number" in
the range 0..3.  A secure association is retired when its 32-bit
packet number would wrap, and the same association number can later be
reused with a new key and packet number.

The standard mode of encryption is GCM AES with 128 bits keys,
although an extension allows 256 bits keys [1] (not implemented in
this submission).

When using MACsec, an extra header, called "SecTAG", is added between
the ethernet header and the original payload:

 +---------------------------------+----------------+----------------+
 |        (MACsec ethertype)       |     TCI_AN     |       SL       |
 +---------------------------------+----------------+----------------+
 |                           Packet Number                           |
 +-------------------------------------------------------------------+
 |                     Secure Channel Identifier                     |
 |                            (optional)                             |
 +-------------------------------------------------------------------+

TCI_AN:
 version
 end_station
 sci_present
 scb
 encrypted
 changed_text
 association_number (2 bits)
SL:
 short_length (6 bits)
 unused (2 bits)

The ethertype for the packet is set to 0x88E5, and the original
ethertype becomes part of the secure payload, which may be encrypted.
The ethernet header and the SecTAG are always transmitted in the
clear, but are integrity-protected.

MACsec supports optional replay protection with a configurable replay
window.

MACsec is designed to be used with the MKA extension to 802.1X (MACsec
Key Agreement protocol) [2], which provides channel attribution and
key distribution to the nodes, but can also be used with static keys
getting fed manually by an administrator.

Optional (not supported yet) features:
 - confidentiality offset: in encryption mode, part of the payload may
   be left unencrypted.
 - choice of cipher suite: GCM AES with 256 bits has been standardised
   [1].

Implementation

A netdevice is created on top of a real device for each TX secure
channel, like we do for VLANs.  Multiple TX channels can be created on
top of the same underlying device.

Several other approaches were considered for the RX path:

 - dev_add_pack: doesn't work, because we want to filter out
   unprotected packets
 - transparent mode: MACsec would be enabled directly on the real
   netdevice.  For this, we cannot use a rx_handler directly because
   MACsec must be available for underlying devices enslaved in a
   bridge or in a bond, so we need a hook directly in
   __netif_receive_skb_core.  This approach makes it harder to filter
   non-encrypted packets on RX without forcing the user to setup some
   rules, so the "transparent" mode is not so transparent after all.
   It also makes TX more complex than with a dedicated netdevice.

One issue with the proposed implementation is that the qdisc layer for
the real device operates on already encrypted packets.

Netlink API

This is currently a mix of rtnetlink (to create the device and set up
the TX channel) and genl (for RX channels, secure associations and
their keys).  genl provides clean demultiplexing of the {TX,RX}{SC,SA}
commands.

Use cases

The normal use case is wired LANs, including veth and slave devices
for bonding/teaming or bridges.

MACsec can also be used on any device that makes a full ethernet
header visible, for example VXLAN.
The VXLAN+MACsec setup would be:

         hypervisor        |     virtual machine
    <real_dev>---<VXLAN>---|---<dev>---<macsec_dev>

And the packets would look like this:

| eth | IP | UDP | VXLAN | eth | MACsec | IP | ... | MACsec ICV |

One benefit on this approach to encryption in the cloud is that the
payload is encrypted by the tenant, not by the tunnel provider, thus
the tenant has full control over the keys.

Changes from v1:
 - rework netlink API after discussion with Johannes Berg
   - nest attributes, rename
   - export stats as separate attributes
   - add some comments
 - misc small fixes (rcu, constants, struct organization)

Changes from RFCv2:
 - fix ENCODING_SA param validation
 - add parent link to netlink ifdumps

Changes from RFCv1:
 - addressed comments from Florian and Paolo + kbuild robot
 - also perform post-decrypt handling after crypto callback
 - fixed ->dellink behavior

Future plans:
 - offload to hardware, on nics that support it
 - implement optional features

[0] http://standards.ieee.org/getieee802/download/802.1AE-2006.pdf
[1] http://standards.ieee.org/getieee802/download/802.1AEbn-2011.pdf
[2] http://standards.ieee.org/getieee802/download/802.1X-2010.pdf
[3] RFCv1: http://www.spinics.net/lists/netdev/msg358151.html
[4] RFCv2: http://www.spinics.net/lists/netdev/msg362389.html
[5] v1: http://www.spinics.net/lists/netdev/msg367959.html
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This is an implementation of MACsec/IEEE 802.1AE.  This driver
provides authentication and encryption of traffic in a LAN, typically
with GCM-AES-128, and optional replay protection.

http://standards.ieee.org/getieee802/download/802.1AE-2006.pdfSigned-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is no need to use the static variable here, pr_info_once is more
concise.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When operating the at803x in SGMII mode, resuming the chip
from power down brings up the copper-side link but leaves
the SGMII link in unconnected state (tested with at8031
attached to gianfar). In effect, this caused a permanent
link loss once the related interface was put down.

This patch ensures that power down handling in supspend()
and resume() is also applied to the SGMII link.
Signed-off-by: Zefir Kurtisi <zefir.kurtisi@neratec.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jesper Dangaard Brouer says:

====================
net: bulk free adjustment and two driver use-cases

I've split out the bulk free adjustments, from the bulk alloc patches,
as I want the adjustment to napi_consume_skb be in same kernel cycle
the API was introduced.

Adjustments based on discussion:
 Subj: "mlx4: use napi_consume_skb API to get bulk free operations"
 http://thread.gmane.org/gmane.linux.network/402503/focus=403386

Patchset based on net-next at commit 3ebeac1d

V4: more nitpicks from Sergei
V3: spelling fixes from Sergei
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Bulk free of SKBs happen transparently by the API call napi_consume_skb().
The napi budget parameter is needed by napi_consume_skb() to detect
if called from netpoll.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bulk free of SKBs happen transparently by the API call napi_consume_skb().
The napi budget parameter is usually needed by napi_consume_skb()
to detect if called from netpoll.  In this patch it has an extra meaning.

For mlx4 driver, the mlx4_en_stop_port() call is done outside
NAPI/softirq context, and cleanup the entire TX ring via
mlx4_en_free_tx_buf().  The code mlx4_en_free_tx_desc() for
freeing SKBs are shared with NAPI calls.

To handle this shared use the zero budget indication is reused,
and handled appropriately in napi_consume_skb(). To reflect this,
variable is called napi_mode for the function call that needed
this distinction.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some drivers reuse/share code paths that free SKBs between NAPI
and non-NAPI calls. Adjust napi_consume_skb to handle this
use-case.

Before, calls from netpoll (w/ IRQs disabled) was handled and
indicated with a budget zero indication.  Use the same zero
indication to handle calls not originating from NAPI/softirq.
Simply handled by using dev_consume_skb_any().

This adds an extra branch+call for the netpoll case (checking
in_irq() + irqs_disabled()), but that is okay as this is a slowpath.
Suggested-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>