David Ahern says:

====================
net: Add extack for route add/delete failures

Use the extack feature to improve error messages to user on route
add and delete failures.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add messages for non-obvious errors (e.g, no need to add text for malloc
failures or ENODEV failures). This mostly covers the annoying EINVAL errors
Some message strings violate the 80-columns but searchable strings need to
trump that rule.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Plumb extack argument down to route add functions.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add messages for non-obvious errors (e.g, no need to add text for malloc
failures or ENODEV failures). This mostly covers the annoying EINVAL errors
Some message strings violate the 80-columns but searchable strings need to
trump that rule.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Plumb extack argument down to route add functions.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The macsec implementation shouldn't account for rx/tx packets that are
dropped in the netdev framework. The netdev framework itself accounts
for such packets by atomically updating struct net_device`rx_dropped and
struct net_device`tx_dropped fields. Later on when the stats for macsec
link is retrieved, the packets dropped in netdev framework will be
included in dev_get_stats() after calling macsec.c`macsec_get_stats64()
Signed-off-by: NGirish Moodalbail <girish.moodalbail@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Needs to follow the existing sequence.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A definition was only provided for asm-generic/socket.h
using platforms, define it for the others as well
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TCP_USER_TIMEOUT is still converted to jiffies value in
icsk_user_timeout

So we need to make a conversion for the cases HZ != 1000

Fixes: 9a568de4 ("tcp: switch TCP TS option (RFC 7323) to 1ms clock")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

THe seg6_pernet_data variable was set but never used.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The build header functions are not used by any other code.

net/ipv6/fou6.c:36:5: warning: no previous prototype for ‘fou6_build_header’ [-Wmissing-prototypes]
net/ipv6/fou6.c:54:5: warning: no previous prototype for ‘gue6_build_header’ [-Wmissing-prototypes]

Need to do some code rearranging to satisfy different Kconfig possiblities.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The TCP New Vegas congestion control was exporting an internal
function tcpnv_get_info which is not used by any other in tree
kernel code. Make it static.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The prototype for inet_rcv_saddr_equal was not being included.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This warning:
net/ipv6/ila/ila_lwt.c: In function ‘ila_output’:
net/ipv6/ila/ila_lwt.c:42:6: warning: variable ‘err’ set but not used [-Wunused-but-set-variable]

It looks like the code attempts to set propagate different error
values, but always returned -EINVAL.

Compile tested only. Needs review by original author.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Found by reviewing the warning about unused policy table.
The code implies that it meant to check for size, but since
it unrolled the loop for attribute validation that is never used.
Instead do explicit check for attribute.

Compile tested only. Needs review by original author.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Miroslav Lichvar says:

====================
Extend socket timestamping API

Changes v5->v6:
- fixed skb_is_swtx_tstamp() when OPT_TX_SWHW is disabled and improved
  its description
- improved OPT_PKTINFO documentation
- improved scm_timestamping documentation

Changes v4->v5:
- fixed initialization of reserved fields in struct scm_ts_pktinfo

Changes v3->v4:
- added reserved fields to struct scm_ts_pktinfo
- replaced patch fixing false SW timestamps with a documentation fix
- updated OPT_TX_SWHW patch to handle false SW timestamps

Changes v2->v3:
- modified struct scm_ts_pktinfo to use fixed-width integer types
- added WARN_ON_ONCE for missing RCU lock in dev_get_by_napi_id()
- modified dev_get_by_napi_id() to not return dev in unexpected branch
- modified recv to return SCM_TIMESTAMPING_PKTINFO even if the interface
  index is unknown

Changes v1->v2:
- added separate patch for new NAPI functions
- split code from __sock_recv_timestamp() for better readability
- fixed RCU locking
- fixed compiler warning (missing case in switch in first patch)
- inline sw_tx_timestamp() in its only user

Changes RFC->v1:
- reworked SOF_TIMESTAMPING_OPT_PKTINFO patch to not add new fields to
  skb shared info (net device is now looked up by napi_id), not require
  any changes in drivers, and restrict the cmsg to incoming packets
- renamed SOF_TIMESTAMPING_OPT_MULTIMSG to SOF_TIMESTAMPING_OPT_TX_SWHW
  and fixed its description
- moved struct scm_ts_pktinfo from errqueue.h to net_tstamp.h as it
  can't be received from the error queue anymore
- improved commit descriptions and removed incorrect comment

This patchset adds new options to the timestamping API that will be
useful for NTP implementations and possibly other applications.

The first patch specifies a timestamp filter for NTP packets. The second
patch updates drivers that can timestamp all packets, or need to list
the filter as unsupported. There is no attempt to add the support to the
phyter driver.

The third patch adds two helper functions working with NAPI ID, which is
needed by the next patch. The fourth patch adds a new option to get a
new control message with the L2 length and interface index for incoming
packets with hardware timestamps.

The fifth patch fixes documentation on number of non-zero fields in
scm_timestamping and warns about false software timestamps when
SO_TIMESTAMP(NS) is combined with SCM_TIMESTAMPING.

The sixth patch adds a new option to request both software and hardware
timestamps for outgoing packets. The seventh patch updates drivers that
assumed software timestamping cannot be used together with hardware
timestamping.

The patches have been tested on x86_64 machines with igb and e1000e
drivers.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some drivers were calling the skb_tx_timestamp() function only when
a hardware timestamp was not requested. Now that applications can use
the SOF_TIMESTAMPING_OPT_TX_SWHW option to request both software and
hardware timestamps, the drivers need to be modified to unconditionally
call skb_tx_timestamp().

CC: Richard Cochran <richardcochran@gmail.com>
CC: Willem de Bruijn <willemb@google.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add SOF_TIMESTAMPING_OPT_TX_SWHW option to allow an outgoing packet to
be looped to the socket's error queue with a software timestamp even
when a hardware transmit timestamp is expected to be provided by the
driver.

Applications using this option will receive two separate messages from
the error queue, one with a software timestamp and the other with a
hardware timestamp. As the hardware timestamp is saved to the shared skb
info, which may happen before the first message with software timestamp
is received by the application, the hardware timestamp is copied to the
SCM_TIMESTAMPING control message only when the skb has no software
timestamp or it is an incoming packet.

While changing sw_tx_timestamp(), inline it in skb_tx_timestamp() as
there are no other users.

CC: Richard Cochran <richardcochran@gmail.com>
CC: Willem de Bruijn <willemb@google.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The scm_timestamping struct may return multiple non-zero fields, e.g.
when both software and hardware RX timestamping is enabled, or when the
SO_TIMESTAMP(NS) option is combined with SCM_TIMESTAMPING and a false
software timestamp is generated in the recvmsg() call in order to always
return a SCM_TIMESTAMP(NS) message.

CC: Richard Cochran <richardcochran@gmail.com>
CC: Willem de Bruijn <willemb@google.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add SOF_TIMESTAMPING_OPT_PKTINFO option to request a new control message
for incoming packets with hardware timestamps. It contains the index of
the real interface which received the packet and the length of the
packet at layer 2.

The index is useful with bonding, bridges and other interfaces, where
IP_PKTINFO doesn't allow applications to determine which PHC made the
timestamp. With the L2 length (and link speed) it is possible to
transpose preamble timestamps to trailer timestamps, which are used in
the NTP protocol.

While this information could be provided by two new socket options
independently from timestamping, it doesn't look like they would be very
useful. With this option any performance impact is limited to hardware
timestamping.

Use dev_get_by_napi_id() to get the device and its index. On kernels
with disabled CONFIG_NET_RX_BUSY_POLL or drivers not using NAPI, a zero
index will be returned in the control message.

CC: Richard Cochran <richardcochran@gmail.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit b6858177 ("net: Make skb->skb_iif always track
skb->dev") skbs don't have the original index of the interface which
received the packet. This information is now needed for a new control
message related to hardware timestamping.

Instead of adding a new field to skb, we can find the device by the NAPI
ID if it is available, i.e. CONFIG_NET_RX_BUSY_POLL is enabled and the
driver is using NAPI. Add dev_get_by_napi_id() and also skb_napi_id() to
hide the CONFIG_NET_RX_BUSY_POLL ifdef.

CC: Richard Cochran <richardcochran@gmail.com>
Suggested-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Include HWTSTAMP_FILTER_NTP_ALL in net_hwtstamp_validate() as a valid
filter and update drivers which can timestamp all packets, or which
explicitly list unsupported filters instead of using a default case, to
handle the filter.

CC: Richard Cochran <richardcochran@gmail.com>
CC: Willem de Bruijn <willemb@google.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add HWTSTAMP_FILTER_NTP_ALL to the hwtstamp_rx_filters enum for
timestamping of NTP packets. There is currently only one driver
(phyter) that could support it directly.

CC: Richard Cochran <richardcochran@gmail.com>
CC: Willem de Bruijn <willemb@google.com>
Signed-off-by: NMiroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

issue get port information command to firmware to retrieve port
information and update if it is different from what was last
recorded and also add indication for supported link modes for
firmware port types FW_PORT_TYPE_SFP28, FW_PORT_TYPE_KR_SFP28,
FW_PORT_TYPE_CR4_QSFP.

Based on the original work by Casey Leedom <leedom@chelsio.com>
Signed-off-by: NCasey Leedom <leedom@chelsio.com>
Signed-off-by: NGanesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current largesend and checksum offload feature in ibmveth driver,
 - Source VM sends the TCP packets with ip_summed field set as
   CHECKSUM_PARTIAL and TCP pseudo header checksum is placed in
   checksum field
 - CHECKSUM_PARTIAL flag in SKB will enable ibmveth driver to mark
   "no checksum" and "checksum good" bits in transmit buffer descriptor
   before the packet is delivered to pseries PowerVM Hypervisor
 - If ibmveth has largesend capability enabled, transmit buffer descriptors
   are market accordingly before packet is delivered to Hypervisor
   (along with mss value for packets with length > MSS)
 - Destination VM's ibmveth driver receives the packet with "checksum good"
   bit set and so, SKB's ip_summed field is set with CHECKSUM_UNNECESSARY
 - If "largesend" bit was on, mss value is copied from receive descriptor
   into SKB's gso_size and other flags are appropriately set for
   packets > MSS size
 - The packet is now successfully delivered up the stack in destination VM

The offloads described above works fine for TCP communication among VMs in
the same pseries server ( VM A <=> PowerVM Hypervisor <=> VM B )

We are now enabling support for OVS in pseries PowerVM environment. One of
our requirements is to have ibmveth driver configured in "Trunk" mode, when
they are used with OVS. This is because, PowerVM Hypervisor will no more
bridge the packets between VMs, instead the packets are delivered to
IO Server which hosts OVS to bridge them between VMs or to external
networks (flow shown below),
  VM A <=> PowerVM Hypervisor <=> IO Server(OVS) <=> PowerVM Hypervisor
                                                                   <=> VM B
In "IO server" the packet is received by inbound Trunk ibmveth and then
delivered to OVS, which is then bridged to outbound Trunk ibmveth (shown
below),
        Inbound Trunk ibmveth <=> OVS <=> Outbound Trunk ibmveth

In this model, we hit the following issues which impacted the VM
communication performance,

 - Issue 1: ibmveth doesn't support largesend and checksum offload features
   when configured as "Trunk". Driver has explicit checks to prevent
   enabling these offloads.

 - Issue 2: SYN packet drops seen at destination VM. When the packet
   originates, it has CHECKSUM_PARTIAL flag set and as it gets delivered to
   IO server's inbound Trunk ibmveth, on validating "checksum good" bits
   in ibmveth receive routine, SKB's ip_summed field is set with
   CHECKSUM_UNNECESSARY flag. This packet is then bridged by OVS (or Linux
   Bridge) and delivered to outbound Trunk ibmveth. At this point the
   outbound ibmveth transmit routine will not set "no checksum" and
   "checksum good" bits in transmit buffer descriptor, as it does so only
   when the ip_summed field is CHECKSUM_PARTIAL. When this packet gets
   delivered to destination VM, TCP layer receives the packet with checksum
   value of 0 and with no checksum related flags in ip_summed field. This
   leads to packet drops. So, TCP connections never goes through fine.

 - Issue 3: First packet of a TCP connection will be dropped, if there is
   no OVS flow cached in datapath. OVS while trying to identify the flow,
   computes the checksum. The computed checksum will be invalid at the
   receiving end, as ibmveth transmit routine zeroes out the pseudo
   checksum value in the packet. This leads to packet drop.

 - Issue 4: ibmveth driver doesn't have support for SKB's with frag_list.
   When Physical NIC has GRO enabled and when OVS bridges these packets,
   OVS vport send code will end up calling dev_queue_xmit, which in turn
   calls validate_xmit_skb.
   In validate_xmit_skb routine, the larger packets will get segmented into
   MSS sized segments, if SKB has a frag_list and if the driver to which
   they are delivered to doesn't support NETIF_F_FRAGLIST feature.

This patch addresses the above four issues, thereby enabling end to end
largesend and checksum offload support for better performance.

 - Fix for Issue 1 : Remove checks which prevent enabling TCP largesend and
   checksum offloads.
 - Fix for Issue 2 : When ibmveth receives a packet with "checksum good"
   bit set and if its configured in Trunk mode, set appropriate SKB fields
   using skb_partial_csum_set (ip_summed field is set with
   CHECKSUM_PARTIAL)
 - Fix for Issue 3: Recompute the pseudo header checksum before sending the
   SKB up the stack.
 - Fix for Issue 4: Linearize the SKBs with frag_list. Though we end up
   allocating buffers and copying data, this fix gives
   upto 4X throughput increase.

Note: All these fixes need to be dropped together as fixing just one of
them will lead to other issues immediately (especially for Issues 1,2 & 3).
Signed-off-by: NSivakumar Krishnasamy <ksiva@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Yuval Mintz says:

====================
qed/qede updates

This series contains some general minor fixes and enhancements:

 - #1, #2 and #9 correct small missing ethtool functionality.
 - #3, #6  and #8 correct minor issues in driver, but those are either
   print-related or unexposed in existing code.
 - #4 adds proper support to TLB mode bonding.
 - #10 is meant to improve performance on varying cache-line sizes.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some variants of adapters support the 1G speed capability. Need to
allow the configuration of 1G speed if adapter supports it.
Signed-off-by: NSudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The management firmware HSI contains masks which are already
shifted to their right place, so QED_MFW_SET_FIELD() is clearing
incorrect fields by shifting the mask by the offset.

Luckily, today we set the fields in an incrementing order [so we're
not erasing any previously set fields], but this still needs fixing.
Signed-off-by: NTomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is benign, but it makes more sense to start the close sequence
only after changing the internal state [in case it would once care].
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If too many CQs are requested, qed would print the available
number as if it's a resource and not a feature leading to the
wrong print.

Fixes: 08737a3f ("qed: Inform qedi the number of possible CQs")
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Re-organize the logic that allocates and frees memory of various
sub-components of the hw-function -

 a. No need to pass pointers to said structure as parameters;
    The internal logic knows exactly where to find/set the data.

 b. Nullify pointers after cleanup to prevent possible errors to
    re-entrant code.
Signed-off-by: NTomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Driver maintains its primary MAC in a private field which
gets updated when ndo_dev_set_mac() gets called.

However, there are flows where the primary MAC of the device can change
without said NDO being called [bond device in TLB mode configuring
slaves' addresses], resulting in a configuration where there's a mismatch
between what's apparent to user [the netdevice's value] and what's
configured in the HW [the private value].

As we don't have any real motivation of maintaining this
private field, simply remove it and start using the netdevice's
field instead.
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When destroying the datapath channels, qede doesn't notify qed of the
released status blocks which were acquired during the initialization.
Signed-off-by: NSudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Driver always allocates the maximal number of tx-buffers irrespective of
actual Tx ring config.
Signed-off-by: NSudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When management firmware declares that the device is WoL-capable,
the default driver behavior would be to allow the management firmware
to take the decision of whether it's actually needed or not.

Problem is ethtool interface doesn't have a 'default' kind
of option, and user would see the interface WoL as disabled,
which doesn't accurately reflect the actual configuration.
More-so, if the user actually wants to explicitly disable WoL he'd have
to first enable it [otherwise ethtool would block the command].

Instead of allowing management to make the decision, enable WoL by
default on all devices capable of it.
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Iyappan Subramanian says:

====================
Check all RGMII phy mode variants

This patch set,
     - adds phy_interface_mode_is_rgmii() helper function
     - addresses review comment from previous patch set, by calling
       phy_interface_mode_is_rgmii() to address all RGMII variants

v2: Address review comments from v1
     - adds phy_interface_mode_is_rgmii() helper function
     - addresses review comment from previous patch set, by calling
       phy_interface_mode_is_rgmii() to address all RGMII variants
v1:
     - Initial version
====================
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch addresses the review comment from the previous patch set,
by using phy_interface_mode_is_rgmii() helper function to address
all RGMII phy mode variants.
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NQuan Nguyen <qnguyen@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added helper function that checks phy_mode is RGMII (all variants)
'bool phy_interface_mode_is_rgmii(phy_interface_t mode)'

Changed the following function, to use the above.
'bool phy_interface_is_rgmii(struct phy_device *phydev)'
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Suggested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Suggested-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Davide Caratti says:

====================
net: fix CRC32c in the forwarding path

Current kernel allows offloading CRC32c computation when SCTP packets
are generated, setting skb->ip_summed to CHECKSUM_PARTIAL, if the
underlying device features have NETIF_F_SCTP_CRC set. However, after these
packets are forwarded, they may land on a device where CRC32c offloading is
not available: as a consequence, transmission is done with wrong CRC32c.
It's not possible to use sctp_compte_cksum() in the forwarding path
and in most drivers, because it needs symbols exported by libcrc32c module.

Patch 1 and 2 of this series try to solve this problem, introducing a new
helper function, namely skb_crc32c_csum_help(), that can be used to resolve
CHECKSUM_PARTIAL when crc32c is needed instead of Internet Checksum.

Currently, we need to parse the packet headers to understand what algorithm
is needed to resolve CHECKSUM_PARTIAL. We can speedup things by storing
this information in the skb metadata, and use it to call an appropriate
helper (skb_checksum_help or skb_crc32c_csum_help), or leave the packet
unmodified when the NIC is able to offload the checksum computation.

Patch 3 deprecates skb->csum_bad to free one bit in skb metadata; patch 4
introduces skb->csum_not_inet, providing skb with an indication on the
algorithm needed to resolve CHECKSUM_PARTIAL.
Patch 5 and 6 fix the kernel forwarding path and openvswitch datapath,
where skb_checksum_help was unconditionally called to resolve CHECKSUM_PARTIAL,
thus generating wrong CRC32c in forwarded SCTP packets.
Finally, patch 7 updates documentation to provide a better description of
possible values of skb->ip_summed.

Some further work is still possible:
* drivers that parse the packet header to correctly resolve CHECKSUM_PARTIAL
(e.g. ixgbe_tx_csum()) can benefit from testing skb->csum_not_inet to avoid
calling ip_hdr(skb)->protocol or ixgbe_ipv6_csum_is_sctp(skb).

* drivers that call skb_checksum_help() to resolve CHECKSUM_PARTIAL can
call skb_csum_hwoffload_help to avoid corrupting SCTP packets.

Changes v2->v3:
- patch 1/7: more standard declaration of stub variables

Changes v1->v2:
- none

Changes RFCv4->v1:
- patch 2/7: use WARN_ON_ONCE() instead of BUG_ON(), and avoid computing
CRC32c on the error path.
- patch 3/7: don't invert tests on the values of same_flow and
NAPI_GRO_CB(skb)->flush in dev_gro_receive(), it's useless and it breaks
GRO functionality as reported by kernel test robot.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add FCoE to the list of protocols that can set CHECKSUM_UNNECESSARY; add a
note to CHECKSUM_COMPLETE section to specify that it does not apply to SCTP
and FCoE protocols.
Suggested-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Acked-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>