[RFC libnftnl/nft 0/5] nftables: indicate presence of unsupported netlink attributes

[Florian Westphal <fw@strlen.de>]

This extends linftnl/nftables to indicate incomplete expressions/sets.

When using old nft binary that cannot list a new expression, nft already
prints an error with the name of the unknown expression.

Extend libnftnl to also make an annotation when a known expression has
an unknown attribute included in the dump, then extend nftables to also
display this to the user.

Debug out out will include the [incomplete] tag for each affected
expression.

Nftables will append '"# Unknown features used (old nft version?)"'
comment to the rule resp. the set defintion.

I added new APIs because existing nftnl_expr_get() can't be re-used,
inserting a new common attribute like NFTNL_EXPR_COMPLETE will break ABI.

It would make sense to also add
nftnl_XXX_complete functions for table, chains, objects and flowtables so we
have coverage for all supported types in one go, but I think its better
to first check for feedback before doing this.

libnftnl:
Florian Westphal (3):
  expr: add and use incomplete tag
  sets: add and use incomplete tag
  libnftnl: add api to query dissection state

 include/data_reg.h      |  1 +
 include/expr.h          |  1 +
 include/libnftnl/expr.h |  2 ++
 include/libnftnl/set.h  |  1 +
 include/set.h           |  1 +
 src/expr.c              |  6 ++++++
 src/expr/bitwise.c      |  8 +++++---
 src/expr/byteorder.c    |  9 ++++++---
 src/expr/cmp.c          |  9 ++++++---
 src/expr/connlimit.c    |  9 ++++++---
 src/expr/counter.c      |  9 ++++++---
 src/expr/ct.c           |  9 ++++++---
 src/expr/data_reg.c     | 19 +++++++++++++------
 src/expr/dup.c          |  9 ++++++---
 src/expr/dynset.c       |  9 ++++++---
 src/expr/exthdr.c       |  8 +++++---
 src/expr/fib.c          |  9 ++++++---
 src/expr/flow_offload.c |  9 ++++++---
 src/expr/fwd.c          |  8 +++++---
 src/expr/hash.c         |  8 +++++---
 src/expr/immediate.c    |  8 +++++---
 src/expr/inner.c        |  8 +++++---
 src/expr/last.c         |  8 +++++---
 src/expr/limit.c        |  8 +++++---
 src/expr/log.c          |  8 +++++---
 src/expr/lookup.c       |  8 +++++---
 src/expr/masq.c         |  8 +++++---
 src/expr/match.c        |  8 +++++---
 src/expr/meta.c         |  6 ++++++
 src/expr/nat.c          |  8 +++++---
 src/expr/numgen.c       |  8 +++++---
 src/expr/objref.c       |  8 +++++---
 src/expr/osf.c          |  9 +++++----
 src/expr/payload.c      |  8 +++++---
 src/expr/queue.c        |  9 ++++++---
 src/expr/quota.c        |  8 +++++---
 src/expr/range.c        |  8 +++++---
 src/expr/redir.c        |  8 +++++---
 src/expr/reject.c       |  9 ++++++---
 src/expr/rt.c           |  9 ++++++---
 src/expr/socket.c       |  9 ++++++---
 src/expr/synproxy.c     | 16 ++++++++--------
 src/expr/target.c       |  9 ++++++---
 src/expr/tproxy.c       |  8 +++++---
 src/expr/tunnel.c       |  8 +++++---
 src/expr/xfrm.c         |  8 +++++---
 src/libnftnl.map        |  5 +++++
 src/rule.c              |  5 +++++
 src/set.c               |  6 ++++++
 src/set_elem.c          |  5 +++++
 50 files changed, 259 insertions(+), 126 deletions(-)

nft:
Florian Westphal (2):
      netlink: tell user if libnftnl detected unknown attributes/features
      sets: inform user when set definition contains unknown attributes

 include/netlink.h         |    1 +
 include/rule.h            |    2 ++
 src/netlink.c             |    3 +++
 src/netlink_delinearize.c |   24 ++++++++++++++++++++++++
 src/rule.c                |    5 +++++
 5 files changed, 35 insertions(+)
-- 
2.45.2