net: move skb->dropcount to skb->cb[]

Browse source

Commit 977750076d ("af_packet: add interframe drop cmsg (v6)")
unionized skb->mark and skb->dropcount in order to allow recording
of the socket drop count while maintaining struct sk_buff size.

skb->dropcount was introduced since there was no available room
in skb->cb[] in packet sockets. However, its introduction led to
the inability to export skb->mark, or any other aliased field to
userspace if so desired.

Moving the dropcount metric to skb->cb[] eliminates this problem
at the expense of 4 bytes less in skb->cb[] for protocol families
using it.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

...

This commit is contained in:

Eyal Birger 2015-03-01 14:58:31 +02:00 • committed by David S. Miller

parent 3bc3b96f3b

commit 744d5a3e9f

3 changed files with 18 additions and 6 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

2

include/linux/skbuff.h

View file

18

include/net/sock.h

View file

4

net/socket.c

View file