linux-stable.git/include/linux/skbuff.h, branch v4.6.6

net_sched: fix mirrored packets checksum

2016-07-27T15:42:13+00:00

[ Upstream commit 82a31b9231f02d9c1b7b290a46999d517b0d312a ]

Similar to commit 9b368814b336 ("net: fix bridge multicast packet checksum validation")
we need to fixup the checksum for CHECKSUM_COMPLETE when
pushing skb on RX path. Otherwise we get similar splats.

Cc: Jamal Hadi Salim 
Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Acked-by: Jamal Hadi Salim 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

packet: Use symmetric hash for PACKET_FANOUT_HASH.

2016-07-27T15:42:13+00:00

[ Upstream commit eb70db8756717b90c01ccc765fdefc4dd969fc74 ]

People who use PACKET_FANOUT_HASH want a symmetric hash, meaning that
they want packets going in both directions on a flow to hash to the
same bucket.

The core kernel SKB hash became non-symmetric when the ipv6 flow label
and other entities were incorporated into the standard flow hash order
to increase entropy.

But there are no users of PACKET_FANOUT_HASH who want an assymetric
hash, they all want a symmetric one.

Therefore, use the flow dissector to compute a flat symmetric hash
over only the protocol, addresses and ports.  This hash does not get
installed into and override the normal skb hash, so this change has
no effect whatsoever on the rest of the stack.

Reported-by: Eric Leblond 
Tested-by: Eric Leblond 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-03-08T17:34:12+00:00

Several cases of overlapping changes, as well as one instance
(vxlan) of a bug fix in 'net' overlapping with code movement
in 'net-next'.

Signed-off-by: David S. Miller

mld, igmp: Fix reserved tailroom calculation

2016-03-03T20:41:07+00:00

The current reserved_tailroom calculation fails to take hlen and tlen into
account.

skb:
[__hlen__|__data____________|__tlen___|__extra__]
^                                               ^
head                                            skb_end_offset

In this representation, hlen + data + tlen is the size passed to alloc_skb.
"extra" is the extra space made available in __alloc_skb because of
rounding up by kmalloc. We can reorder the representation like so:

[__hlen__|__data____________|__extra__|__tlen___]
^                                               ^
head                                            skb_end_offset

The maximum space available for ip headers and payload without
fragmentation is min(mtu, data + extra). Therefore,
reserved_tailroom
= data + extra + tlen - min(mtu, data + extra)
= skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen)
= skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen)

Compare the second line to the current expression:
reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset)
and we can see that hlen and tlen are not taken into account.

The min() in the third line can be expanded into:
if mtu < skb_tailroom - tlen:
	reserved_tailroom = skb_tailroom - mtu
else:
	reserved_tailroom = tlen

Depending on hlen, tlen, mtu and the number of multicast address records,
the current code may output skbs that have less tailroom than
dev->needed_tailroom or it may output more skbs than needed because not all
space available is used.

Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs")
Signed-off-by: Benjamin Poirier 
Acked-by: Hannes Frederic Sowa 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: remove skb_sender_cpu_clear()

2016-03-01T22:36:47+00:00

After commit 52bd2d62ce67 ("net: better skb->sender_cpu and skb->napi_id cohabitation")
skb_sender_cpu_clear() becomes empty and can be removed.

Cc: Eric Dumazet 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-02-23T05:09:14+00:00

Conflicts:
	drivers/net/phy/bcm7xxx.c
	drivers/net/phy/marvell.c
	drivers/net/vxlan.c

All three conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller

bpf: try harder on clones when writing into skb

2016-02-22T03:07:10+00:00

When we're dealing with clones and the area is not writeable, try
harder and get a copy via pskb_expand_head(). Replace also other
occurences in tc actions with the new skb_try_make_writable().

Reported-by: Ashhad Sheikh 
Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

net: Optimize local checksum offload

2016-02-18T20:29:25+00:00

This patch takes advantage of several assumptions we can make about the
headers of the frame in order to reduce overall processing overhead for
computing the outer header checksum.

First we can assume the entire header is in the region pointed to by
skb->head as this is what csum_start is based on.

Second, as a result of our first assumption, we can just call csum_partial
instead of making a call to skb_checksum which would end up having to
configure things so that we could walk through the frags list.

Signed-off-by: Alexander Duyck 
Signed-off-by: David S. Miller

Documentation/networking: add checksum-offloads.txt to explain LCO

2016-02-12T10:52:16+00:00

Signed-off-by: Edward Cree 
Signed-off-by: David S. Miller

net: local checksum offload for encapsulation

2016-02-12T10:52:15+00:00

The arithmetic properties of the ones-complement checksum mean that a
 correctly checksummed inner packet, including its checksum, has a ones
 complement sum depending only on whatever value was used to initialise
 the checksum field before checksumming (in the case of TCP and UDP,
 this is the ones complement sum of the pseudo header, complemented).
Consequently, if we are going to offload the inner checksum with
 CHECKSUM_PARTIAL, we can compute the outer checksum based only on the
 packed data not covered by the inner checksum, and the initial value of
 the inner checksum field.

Signed-off-by: Edward Cree 
Signed-off-by: David S. Miller