[PATCH 1/7] netfilter: nf_tables: meter: pick a set backend that supports updates
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2018-03-24 20:34:31
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Florian Westphal <fw@strlen.de>
in nftables, 'meter' can be used to instantiate a hash-table at run
time:
rule add filter forward iif "internal" meter hostacct { ip saddr counter}
nft list meter ip filter hostacct
table ip filter {
meter hostacct {
type ipv4_addr
elements = { 192.168.0.1 : counter packets 8 bytes 2672, ..
because elemets get added on the fly, the kernel must chose a set
backend type that implements the ->update() function, otherwise
rule insertion fails with EOPNOTSUPP.
Therefore, skip set types that lack ->update, and also
make sure we do not discard a (bad) candidate when we did yet
find any candidate at all. This could happen when userspace prefers
low memory footprint -- the set implementation currently checked might
not be a fit at all. Make sure we pick it anyway (!bops). In
case next candidate is a better fix, it will be chosen instead.
But in case nothing else is found we at least have a non-ideal
match rather than no match at all.
Fixes: 6c03ae210ce3 ("netfilter: nft_set_hash: add non-resizable hashtable implementation")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_tables_api.c | 5 ++++-
net/netfilter/nft_set_hash.c | 2 +-
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index c4acc7340eb1..36f69acaf51f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c@@ -2446,6 +2446,9 @@ EXPORT_SYMBOL_GPL(nft_unregister_set); static bool nft_set_ops_candidate(const struct nft_set_ops *ops, u32 flags) { + if ((flags & NFT_SET_EVAL) && !ops->update) + return false; + return (flags & ops->features) == (flags & NFT_SET_FEATURES); }
@@ -2510,7 +2513,7 @@ nft_select_set_ops(const struct nft_ctx *ctx, if (est.space == best.space && est.lookup < best.lookup) break; - } else if (est.size < best.size) { + } else if (est.size < best.size || !bops) { break; } continue;
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index d40591fe1b2f..fc9c6d5d64cd 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c@@ -674,7 +674,7 @@ static const struct nft_set_ops * nft_hash_select_ops(const struct nft_ctx *ctx, const struct nft_set_desc *desc, u32 flags) { - if (desc->size && !(flags & NFT_SET_TIMEOUT)) { + if (desc->size && !(flags & (NFT_SET_EVAL | NFT_SET_TIMEOUT))) { switch (desc->klen) { case 4: return &nft_hash_fast_ops;
--
2.11.0