net: move gso declarations and functions to their own files

Move declarations into include/net/gso.h and code into net/core/gso.c

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stanislav Fom

net: move gso declarations and functions to their own files

Move declarations into include/net/gso.h and code into net/core/gso.c

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: gro: skb_gro_header helper function

Introduce a simple helper function to replace a common pattern.
When accessing the GRO header, we fetch the pointer from frag0,
then test its validity and fe

net: gro: skb_gro_header helper function

Introduce a simple helper function to replace a common pattern.
When accessing the GRO header, we fetch the pointer from frag0,
then test its validity and fetch it from the skb when necessary.

This leads to the pattern
skb_gro_header_fast -> skb_gro_header_hard -> skb_gro_header_slow
recurring many times throughout GRO code.

This patch replaces these patterns with a single inlined function
call, improving code readability.

Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220823071034.GA56142@debian
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers

All gro_complete() handlers are called from napi_gro_complete()
while rcu_read_lock() has been called.

There is no point stackin

gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers

All gro_complete() handlers are called from napi_gro_complete()
while rcu_read_lock() has been called.

There is no point stacking more rcu_read_lock()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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gro: remove rcu_read_lock/rcu_read_unlock from gro_receive handlers

All gro_receive() handlers are called from dev_gro_receive()
while rcu_read_lock() has been called.

There is no point stacking mo

gro: remove rcu_read_lock/rcu_read_unlock from gro_receive handlers

All gro_receive() handlers are called from dev_gro_receive()
while rcu_read_lock() has been called.

There is no point stacking more rcu_read_lock()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: move gro definitions to include/net/gro.h

include/linux/netdevice.h became too big, move gro stuff
into include/net/gro.h

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David

net: move gro definitions to include/net/gro.h

include/linux/netdevice.h became too big, move gro stuff
into include/net/gro.h

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ip_gre: add csum offload support for gre header

This patch is to add csum offload support for gre header:

On the TX path in gre_build_header(), when CHECKSUM_PARTIAL's set
for inner proto, it will

ip_gre: add csum offload support for gre header

This patch is to add csum offload support for gre header:

On the TX path in gre_build_header(), when CHECKSUM_PARTIAL's set
for inner proto, it will calculate the csum for outer proto, and
inner csum will be offloaded later. Otherwise, CHECKSUM_PARTIAL
and csum_start/offset will be set for outer proto, and the outer
csum will be offloaded later.

On the GSO path in gre_gso_segment(), when CHECKSUM_PARTIAL is
not set for inner proto and the hardware supports csum offload,
CHECKSUM_PARTIAL and csum_start/offset will be set for outer
proto, and outer csum will be offloaded later. Otherwise, it
will do csum for outer proto by calling gso_make_checksum().

Note that SCTP has to do the csum by itself for non GSO path in
sctp_packet_pack(), as gre_build_header() can't handle the csum
with CHECKSUM_PARTIAL set for SCTP CRC csum offload.

v1->v2:
- remove the SCTP part, as GRE dev doesn't support SCTP CRC CSUM
and it will always do checksum for SCTP in sctp_packet_pack()
when it's not a GSO packet.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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ip_gre: remove CRC flag from dev features in gre_gso_segment

This patch is to let it always do CRC checksum in sctp_gso_segment()
by removing CRC flag from the dev features in gre_gso_segment() for

ip_gre: remove CRC flag from dev features in gre_gso_segment

This patch is to let it always do CRC checksum in sctp_gso_segment()
by removing CRC flag from the dev features in gre_gso_segment() for
SCTP over GRE, just as it does in Commit 527beb8ef9c0 ("udp: support
sctp over udp in skb_udp_tunnel_segment") for SCTP over UDP.

It could set csum/csum_start in GSO CB properly in sctp_gso_segment()
after that commit, so it would do checksum with gso_make_checksum()
in gre_gso_segment(), and Commit 622e32b7d4a6 ("net: gre: recompute
gre csum for sctp over gre tunnels") can be reverted now.

Note that when need_csum is false, we can still leave CRC checksum
of SCTP to HW by not clearing this CRC flag if it's supported, as
Jakub and Alex noticed.

v1->v2:
- improve the changelog.
- fix "rev xmas tree" in varibles declaration.
v2->v3:
- remove CRC flag from dev features only when need_csum is true.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/00439f24d5f69e2c6fa2beadc681d056c15c258f.1610772251.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: gre: recompute gre csum for sctp over gre tunnels

The GRE tunnel can be used to transport traffic that does not rely on a
Internet checksum (e.g. SCTP). The issue can be triggered creating a GR

net: gre: recompute gre csum for sctp over gre tunnels

The GRE tunnel can be used to transport traffic that does not rely on a
Internet checksum (e.g. SCTP). The issue can be triggered creating a GRE
or GRETAP tunnel and transmitting SCTP traffic ontop of it where CRC
offload has been disabled. In order to fix the issue we need to
recompute the GRE csum in gre_gso_segment() not relying on the inner
checksum.
The issue is still present when we have the CRC offload enabled.
In this case we need to disable the CRC offload if we require GRE
checksum since otherwise skb_checksum() will report a wrong value.

Fixes: 90017accff61 ("sctp: Add GSO support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: remove the check argument from __skb_gro_checksum_convert

The argument is always ignored, so remove it.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Simon Horman <simon.horma

net: remove the check argument from __skb_gro_checksum_convert

The argument is always ignored, so remove it.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of th

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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net: fix use-after-free in GRO with ESP

Since the addition of GRO for ESP, gro_receive can consume the skb and
return -EINPROGRESS. In that case, the lower layer GRO handler cannot
touch the skb any

net: fix use-after-free in GRO with ESP

Since the addition of GRO for ESP, gro_receive can consume the skb and
return -EINPROGRESS. In that case, the lower layer GRO handler cannot
touch the skb anymore.

Commit 5f114163f2f5 ("net: Add a skb_gro_flush_final helper.") converted
some of the gro_receive handlers that can lead to ESP's gro_receive so
that they wouldn't access the skb when -EINPROGRESS is returned, but
missed other spots, mainly in tunneling protocols.

This patch finishes the conversion to using skb_gro_flush_final(), and
adds a new helper, skb_gro_flush_final_remcsum(), used in VXLAN and
GUE.

Fixes: 5f114163f2f5 ("net: Add a skb_gro_flush_final helper.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: Convert GRO SKB handling to list_head.

Manage pending per-NAPI GRO packets via list_head.

Return an SKB pointer from the GRO receive handlers. When GRO receive
handlers return non-NULL, it me

net: Convert GRO SKB handling to list_head.

Manage pending per-NAPI GRO packets via list_head.

Return an SKB pointer from the GRO receive handlers. When GRO receive
handlers return non-NULL, it means that this SKB needs to be completed
at this time and removed from the NAPI queue.

Several operations are greatly simplified by this transformation,
especially timing out the oldest SKB in the list when gro_count
exceeds MAX_GRO_SKBS, and napi_gro_flush() which walks the queue
in reverse order.

Signed-off-by: David S. Miller <davem@davemloft.net>

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gso: fix payload length when gso_size is zero

When gso_size reset to zero for the tail segment in skb_segment(), later
in ipv6_gso_segment(), __skb_udp_tunnel_segment() and gre_gso_segment()
we will

gso: fix payload length when gso_size is zero

When gso_size reset to zero for the tail segment in skb_segment(), later
in ipv6_gso_segment(), __skb_udp_tunnel_segment() and gre_gso_segment()
we will get incorrect results (payload length, pcsum) for that segment.
inet_gso_segment() already has a check for gso_size before calculating
payload.

The issue was found with LTP vxlan & gre tests over ixgbe NIC.

Fixes: 07b26c9454a2 ("gso: Support partial splitting at the frag_list pointer")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: Remove all references to SKB_GSO_UDP.

Such packets are no longer possible.

Signed-off-by: David S. Miller <davem@davemloft.net>

net: add recursion limit to GRO

Currently, GRO can do unlimited recursion through the gro_receive
handlers. This was fixed for tunneling protocols by limiting tunnel GRO
to one level with encap_mar

net: add recursion limit to GRO

Currently, GRO can do unlimited recursion through the gro_receive
handlers. This was fixed for tunneling protocols by limiting tunnel GRO
to one level with encap_mark, but both VLAN and TEB still have this
problem. Thus, the kernel is vulnerable to a stack overflow, if we
receive a packet composed entirely of VLAN headers.

This patch adds a recursion counter to the GRO layer to prevent stack
overflow. When a gro_receive function hits the recursion limit, GRO is
aborted for this skb and it is processed normally. This recursion
counter is put in the GRO CB, but could be turned into a percpu counter
if we run out of space in the CB.

Thanks to Vladimír Beneš <vbenes@redhat.com> for the initial bug report.

Fixes: CVE-2016-7039
Fixes: 9b174d88c257 ("net: Add Transparent Ethernet Bridging GRO support.")
Fixes: 66e5133f19e9 ("vlan: Add GRO support for non hardware accelerated vlan")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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gso: Support partial splitting at the frag_list pointer

Since commit 8a29111c7 ("net: gro: allow to build full sized skb")
gro may build buffers with a frag_list. This can hurt forwarding
because mo

gso: Support partial splitting at the frag_list pointer

Since commit 8a29111c7 ("net: gro: allow to build full sized skb")
gro may build buffers with a frag_list. This can hurt forwarding
because most NICs can't offload such packets, they need to be
segmented in software. This patch splits buffers with a frag_list
at the frag_list pointer into buffers that can be TSO offloaded.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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gso: Remove arbitrary checks for unsupported GSO

In several gso_segment functions there are checks of gso_type against
a seemingly arbitrary list of SKB_GSO_* flags. This seems like an
attempt to id

gso: Remove arbitrary checks for unsupported GSO

In several gso_segment functions there are checks of gso_type against
a seemingly arbitrary list of SKB_GSO_* flags. This seems like an
attempt to identify unsupported GSO types, but since the stack is
the one that set these GSO types in the first place this seems
unnecessary to do. If a combination isn't valid in the first
place that stack should not allow setting it.

This is a code simplication especially for add new GSO types.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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GRE: Add support for GRO/GSO of IPv6 GRE traffic

Since GRE doesn't really care about L3 protocol we can support IPv4 and
IPv6 using the same offloads. With that being the case we can add a call
to

GRE: Add support for GRO/GSO of IPv6 GRE traffic

Since GRE doesn't really care about L3 protocol we can support IPv4 and
IPv6 using the same offloads. With that being the case we can add a call
to register the offloads for IPv6 as a part of our GRE offload
initialization.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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GSO: Support partial segmentation offload

This patch adds support for something I am referring to as GSO partial.
The basic idea is that we can support a broader range of devices for
segmentation if

GSO: Support partial segmentation offload

This patch adds support for something I am referring to as GSO partial.
The basic idea is that we can support a broader range of devices for
segmentation if we use fixed outer headers and have the hardware only
really deal with segmenting the inner header. The idea behind the naming
is due to the fact that everything before csum_start will be fixed headers,
and everything after will be the region that is handled by hardware.

With the current implementation it allows us to add support for the
following GSO types with an inner TSO_MANGLEID or TSO6 offload:
NETIF_F_GSO_GRE
NETIF_F_GSO_GRE_CSUM
NETIF_F_GSO_IPIP
NETIF_F_GSO_SIT
NETIF_F_UDP_TUNNEL
NETIF_F_UDP_TUNNEL_CSUM

In the case of hardware that already supports tunneling we may be able to
extend this further to support TSO_TCPV4 without TSO_MANGLEID if the
hardware can support updating inner IPv4 headers.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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GSO: Add GSO type for fixed IPv4 ID

This patch adds support for TSO using IPv4 headers with a fixed IP ID
field. This is meant to allow us to do a lossless GRO in the case of TCP
flows that use a f

GSO: Add GSO type for fixed IPv4 ID

This patch adds support for TSO using IPv4 headers with a fixed IP ID
field. This is meant to allow us to do a lossless GRO in the case of TCP
flows that use a fixed IP ID such as those that convert IPv6 header to IPv4
headers.

In addition I am adding a feature that for now I am referring to TSO with
IP ID mangling. Basically when this flag is enabled the device has the
option to either output the flow with incrementing IP IDs or with a fixed
IP ID regardless of what the original IP ID ordering was. This is useful
in cases where the DF bit is set and we do not care if the original IP ID
value is maintained.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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GRE: Disable segmentation offloads w/ CSUM and we are encapsulated via FOU

This patch fixes an issue I found in which we were dropping frames if we
had enabled checksums on GRE headers that were enc

GRE: Disable segmentation offloads w/ CSUM and we are encapsulated via FOU

This patch fixes an issue I found in which we were dropping frames if we
had enabled checksums on GRE headers that were encapsulated by either FOU
or GUE. Without this patch I was barely able to get 1 Gb/s of throughput.
With this patch applied I am now at least getting around 6 Gb/s.

The issue is due to the fact that with FOU or GUE applied we do not provide
a transport offset pointing to the GRE header, nor do we offload it in
software as the GRE header is completely skipped by GSO and treated like a
VXLAN or GENEVE type header. As such we need to prevent the stack from
generating it and also prevent GRE from generating it via any interface we
create.

Fixes: c3483384ee511 ("gro: Allow tunnel stacking in the case of FOU/GUE")
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: Reset encap_level to avoid resetting features on inner IP headers

This patch corrects an oversight in which we were allowing the encap_level
value to pass from the outer headers to the inner he

net: Reset encap_level to avoid resetting features on inner IP headers

This patch corrects an oversight in which we were allowing the encap_level
value to pass from the outer headers to the inner headers. As a result we
were incorrectly identifying UDP or GRE tunnels as also making use of ipip
or sit when the second header actually represented a tunnel encapsulated in
either a UDP or GRE tunnel which already had the features masked.

Fixes: 76443456227097179c1482 ("net: Move GSO csum into SKB_GSO_CB")
Reported-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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tunnels: Don't apply GRO to multiple layers of encapsulation.

When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Support

tunnels: Don't apply GRO to multiple layers of encapsulation.

When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Supporting additional levels would mean updating, at a minimum,
more IP length fields and they are unaware of this.

No encapsulation device expresses support for handling offloaded
encapsulated packets, so we won't generate these types of frames
in the transmit path. However, GRO doesn't have a check for
multiple levels of encapsulation and will attempt to build them.

UDP tunnel GRO actually does prevent this situation but it only
handles multiple UDP tunnels stacked on top of each other. This
generalizes that solution to prevent any kind of tunnel stacking
that would cause problems.

Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack")
Signed-off-by: Jesse Gross <jesse@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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gro: Defer clearing of flush bit in tunnel paths

This patch updates the GRO handlers for GRE, VXLAN, GENEVE, and FOU so that
we do not clear the flush bit until after we have called the next level G

gro: Defer clearing of flush bit in tunnel paths

This patch updates the GRO handlers for GRE, VXLAN, GENEVE, and FOU so that
we do not clear the flush bit until after we have called the next level GRO
handler. Previously this was being cleared before parsing through the list
of frames, however this resulted in several paths where either the bit
needed to be reset but wasn't as in the case of FOU, or cases where it was
being set as in GENEVE. By just deferring the clearing of the bit until
after the next level protocol has been parsed we can avoid any unnecessary
bit twiddling and avoid bugs.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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GSO: Provide software checksum of tunneled UDP fragmentation offload

On reviewing the code I realized that GRE and UDP tunnels could cause a
kernel panic if we used GSO to segment a large UDP frame

GSO: Provide software checksum of tunneled UDP fragmentation offload

On reviewing the code I realized that GRE and UDP tunnels could cause a
kernel panic if we used GSO to segment a large UDP frame that was sent
through the tunnel with an outer checksum and hardware offloads were not
available.

In order to correct this we need to update the feature flags that are
passed to the skb_segment function so that in the event of UDP
fragmentation being requested for the inner header the segmentation
function will correctly generate the checksum for the payload if we cannot
segment the outer header.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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