linux-stable.git/include/net/checksum.h, branch linux-4.5.y Linux kernel stable tree rco: Clean up casting errors 2015-12-14T04:57:45+00:00 Tom Herbert tom@herbertland.com 2015-12-10T20:37:44+00:00 369620a09bc5ab867342d51f1820c66b00d78a2c Fixe a couple of cast errors found by sparse. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Fixe a couple of cast errors found by sparse.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Add inet_proto_csum_replace_by_diff utility function 2015-08-18T04:33:06+00:00 Tom Herbert tom@herbertland.com 2015-08-17T20:42:26+00:00 abc5d1ff3e8f9b4a9d274818459b123e31981dc9 This function updates a checksum field value and skb->csum based on a value which is the difference between the old and new checksum. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This function updates a checksum field value and skb->csum based on
a value which is the difference between the old and new checksum.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-18T04:33:06+00:00 Tom Herbert tom@herbertland.com 2015-08-17T20:42:25+00:00 4b048d6d9d0b0b90e1e94f2393796bbf1fa8df4e inet_proto_csum_replace4,2,16 take a pseudohdr argument which indicates the checksum field carries a pseudo header. This argument should be a boolean instead of an int. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
inet_proto_csum_replace4,2,16 take a pseudohdr argument which indicates
the checksum field carries a pseudo header. This argument should be a
boolean instead of an int.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fix sparse error in csum_replace4() 2015-05-17T17:08:29+00:00 Eric Dumazet edumazet@google.com 2015-05-15T15:52:19+00:00 d53a2aa3a116609c7db8799da31541c4ba5999eb make C=2 CF=-D__CHECK_ENDIAN__ net/ipv4/netfilter/nf_nat_l3proto_ipv4.o CHECK net/ipv4/netfilter/nf_nat_l3proto_ipv4.c include/net/checksum.h:125:64: warning: incorrect type in argument 2 (different base types) include/net/checksum.h:125:64: expected restricted __wsum [usertype] addend include/net/checksum.h:125:64: got restricted __be32 [usertype] from include/net/checksum.h:125:71: warning: incorrect type in argument 2 (different base types) include/net/checksum.h:125:71: expected restricted __wsum [usertype] addend include/net/checksum.h:125:71: got restricted __be32 [usertype] to include/net/checksum.h:125:64: warning: incorrect type in argument 2 (different base types) include/net/checksum.h:125:64: expected restricted __wsum [usertype] addend include/net/checksum.h:125:64: got restricted __be32 [usertype] from include/net/checksum.h:125:71: warning: incorrect type in argument 2 (different base types) include/net/checksum.h:125:71: expected restricted __wsum [usertype] addend include/net/checksum.h:125:71: got restricted __be32 [usertype] to Fixes: 4565af0d406b ("net: optimise csum_replace4()") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
make C=2 CF=-D__CHECK_ENDIAN__ net/ipv4/netfilter/nf_nat_l3proto_ipv4.o
  CHECK   net/ipv4/netfilter/nf_nat_l3proto_ipv4.c
include/net/checksum.h:125:64: warning: incorrect type in argument 2 (different base types)
include/net/checksum.h:125:64:    expected restricted __wsum [usertype] addend
include/net/checksum.h:125:64:    got restricted __be32 [usertype] from
include/net/checksum.h:125:71: warning: incorrect type in argument 2 (different base types)
include/net/checksum.h:125:71:    expected restricted __wsum [usertype] addend
include/net/checksum.h:125:71:    got restricted __be32 [usertype] to
include/net/checksum.h:125:64: warning: incorrect type in argument 2 (different base types)
include/net/checksum.h:125:64:    expected restricted __wsum [usertype] addend
include/net/checksum.h:125:64:    got restricted __be32 [usertype] from
include/net/checksum.h:125:71: warning: incorrect type in argument 2 (different base types)
include/net/checksum.h:125:71:    expected restricted __wsum [usertype] addend
include/net/checksum.h:125:71:    got restricted __be32 [usertype] to

Fixes: 4565af0d406b ("net: optimise csum_replace4()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Fix remcsum in GRO path to not change packet 2015-02-11T23:12:09+00:00 Tom Herbert therbert@google.com 2015-02-11T00:30:27+00:00 26c4f7da3e413da697a7beb22ad496390eda7da0 Remote checksum offload processing is currently the same for both the GRO and non-GRO path. When the remote checksum offload option is encountered, the checksum field referred to is modified in the packet. So in the GRO case, the packet is modified in the GRO path and then the operation is skipped when the packet goes through the normal path based on skb->remcsum_offload. There is a problem in that the packet may be modified in the GRO path, but then forwarded off host still containing the remote checksum option. A remote host will again perform RCO but now the checksum verification will fail since GRO RCO already modified the checksum. To fix this, we ensure that GRO restores a packet to it's original state before returning. In this model, when GRO processes a remote checksum option it still changes the checksum per the algorithm but on return from lower layer processing the checksum is restored to its original value. In this patch we add define gro_remcsum structure which is passed to skb_gro_remcsum_process to save offset and delta for the checksum being changed. After lower layer processing, skb_gro_remcsum_cleanup is called to restore the checksum before returning from GRO. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Remote checksum offload processing is currently the same for both
the GRO and non-GRO path. When the remote checksum offload option
is encountered, the checksum field referred to is modified in
the packet. So in the GRO case, the packet is modified in the
GRO path and then the operation is skipped when the packet goes
through the normal path based on skb->remcsum_offload. There is
a problem in that the packet may be modified in the GRO path, but
then forwarded off host still containing the remote checksum option.
A remote host will again perform RCO but now the checksum verification
will fail since GRO RCO already modified the checksum.

To fix this, we ensure that GRO restores a packet to it's original
state before returning. In this model, when GRO processes a remote
checksum option it still changes the checksum per the algorithm
but on return from lower layer processing the checksum is restored
to its original value.

In this patch we add define gro_remcsum structure which is passed
to skb_gro_remcsum_process to save offset and delta for the checksum
being changed. After lower layer processing, skb_gro_remcsum_cleanup
is called to restore the checksum before returning from GRO.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Add remcsum_adjust as common function for remote checksum offload 2014-11-26T17:25:43+00:00 Tom Herbert therbert@google.com 2014-11-25T19:21:19+00:00 7c967b224a9a7061009ccbc47e1a0b605f1b6d81 This function does the work to update a checksum field as part of remote checksum offload. remcsum_adjust does the following: 1) Subtract out the calculated checksum from the beginning of the packet (ptr arg) to the start offset. 2) Adjust the checksum field indicated by offset based on the modified checksum value from above step. 3) Return the difference in the old checksum field value and the new one. The caller will use this to update skb->csum and NAPI csum. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This function does the work to update a checksum field as part of
remote checksum offload.

remcsum_adjust does the following:

1) Subtract out the calculated checksum from the beginning of the
   packet (ptr arg) to the start offset.
2) Adjust the checksum field indicated by offset based on the modified
   checksum value from above step.
3) Return the difference in the old checksum field value and the
   new one. The caller will use this to update skb->csum and NAPI csum.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: optimise csum_replace4() 2014-09-26T20:14:16+00:00 LEROY Christophe christophe.leroy@c-s.fr 2014-09-23T08:54:32+00:00 4565af0d406bed44bc8756230eae8f7caa5e0334 csum_partial() is a generic function which is not optimised for small fixed length calculations, and its use requires to store "from" and "to" values in memory while we already have them available in registers. This also has impact, especially on RISC processors. In the same spirit as the change done by Eric Dumazet on csum_replace2(), this patch rewrites inet_proto_csum_replace4() taking into account RFC1624. I spotted during a NATted tcp transfert that csum_partial() is one of top 5 consuming functions (around 8%), and the second user of csum_partial() is inet_proto_csum_replace4(). I have proposed the same modification to inet_proto_csum_replace4() in another patch. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
csum_partial() is a generic function which is not optimised for small fixed
length calculations, and its use requires to store "from" and "to" values in
memory while we already have them available in registers. This also has impact,
especially on RISC processors. In the same spirit as the change done by
Eric Dumazet on csum_replace2(), this patch rewrites inet_proto_csum_replace4()
taking into account RFC1624.

I spotted during a NATted tcp transfert that csum_partial() is one of top 5
consuming functions (around 8%), and the second user of csum_partial() is
inet_proto_csum_replace4().

I have proposed the same modification to inet_proto_csum_replace4() in another
patch.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Allow csum_add to be provided in arch 2014-05-05T19:26:29+00:00 Tom Herbert therbert@google.com 2014-05-02T23:28:03+00:00 07064c6e022ba8dc0c86ce12f7851a1de24e04fc csum_add is really nothing more then add-with-carry which can be implemented efficiently in some architectures. Allow architecture to define this protected by HAVE_ARCH_CSUM_ADD. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
csum_add is really nothing more then add-with-carry which
can be implemented efficiently in some architectures.
Allow architecture to define this protected by HAVE_ARCH_CSUM_ADD.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: optimize csum_replace2() 2014-03-24T04:18:44+00:00 Eric Dumazet edumazet@google.com 2014-03-24T02:51:36+00:00 99f0b958b194f7d88973f1c2190d207e0a2c7e79 When changing one 16bit value by another in IP header, we can adjust the IP checksum by doing a simple operation described in RFC 1624, as reminded by David. csum_partial() is a complex function on x86_64, not really suited for small number of checksummed bytes. I spotted csum_partial() being in the top 20 most consuming functions (more than 1 %) in a GRO workload, which was rather unexpected. The caller was inet_gro_complete() doing a csum_replace2() when building the new IP header for the GRO packet. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When changing one 16bit value by another in IP header, we can adjust
the IP checksum by doing a simple operation described in RFC 1624, as
reminded by David.

csum_partial() is a complex function on x86_64, not really suited for
small number of checksummed bytes.

I spotted csum_partial() being in the top 20 most consuming functions
(more than 1 %) in a GRO workload, which was rather unexpected.

The caller was inet_gro_complete() doing a csum_replace2() when
building the new IP header for the GRO packet.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: checksum: fix warning in skb_checksum 2013-11-04T20:27:08+00:00 Daniel Borkmann dborkman@redhat.com 2013-11-04T16:10:25+00:00 cea80ea8d2a4c646f240a8fd6ece5c8e7bc969d3 This patch fixes a build warning in skb_checksum() by wrapping the csum_partial() usage in skb_checksum(). The problem is that on a few architectures, csum_partial is used with prefix asmlinkage whereas on most architectures it's not. So fix this up generically as we did with csum_block_add_ext() to match the signature. Introduced by 2817a336d4d ("net: skb_checksum: allow custom update/combine for walking skb"). Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This patch fixes a build warning in skb_checksum() by wrapping the
csum_partial() usage in skb_checksum(). The problem is that on a few
architectures, csum_partial is used with prefix asmlinkage whereas
on most architectures it's not. So fix this up generically as we did
with csum_block_add_ext() to match the signature. Introduced by
2817a336d4d ("net: skb_checksum: allow custom update/combine for
walking skb").

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>