[PATCH nf-next 0/4] netfilter: conntrack: avoid eache extension allocation

[Florian Westphal <fw@strlen.de>]

This patch series changes ecache infra to no longer allocate the
extension by default.

After this series, the default behaviour is to allocate the
extension if either a conntrack template has been set to configure event
masks via nft/iptables ruleset, the syctl 'nf_conntrack_events' is set
to 1, or if a userspace program has subscribed to one of the ctnetlink
event groups.

This has advantages in case the events are not used:
1. Conntrack allocation/free avoids extra kmalloc/kfree call.
2. nf_confirm hook doesn't perform an indirect call into ctnetlink
   only to discover that there is nothing to do.

Florian Westphal (4):
  netfilter: nfnetlink: allow to detect if ctnetlink listeners exist
  netfilter: conntrack: un-inline nf_ct_ecache_ext_add
  netfilter: conntrack: add nf_conntrack_events autodetect mode
  netfilter: prefer extension check to pointer check

 .../networking/nf_conntrack-sysctl.rst        |  5 +-
 include/net/netfilter/nf_conntrack_core.h     |  2 +-
 include/net/netfilter/nf_conntrack_ecache.h   | 49 ++++++-------------
 include/net/netns/conntrack.h                 |  1 +
 net/netfilter/nf_conntrack_core.c             | 15 ++++--
 net/netfilter/nf_conntrack_ecache.c           | 39 ++++++++++++++-
 net/netfilter/nf_conntrack_standalone.c       |  2 +-
 net/netfilter/nfnetlink.c                     | 40 +++++++++++++--
 8 files changed, 108 insertions(+), 45 deletions(-)

-- 
2.35.1