From: Florian Westphal fw@strlen.de
[ Upstream commit acab713177377d9e0889c46bac7ff0cfb9a90c4d ]
This un-breaks lookups in sets that have the 'dynamic' flag set. Given this active example configuration:
table filter { set set1 { type ipv4_addr size 64 flags dynamic,timeout timeout 1m }
chain input { type filter hook input priority 0; policy accept; } }
... this works: nft add rule ip filter input add @set1 { ip saddr }
-> whenever rule is triggered, the source ip address is inserted into the set (if it did not exist).
This won't work: nft add rule ip filter input ip saddr @set1 counter Error: Could not process rule: Operation not supported
In other words, we can add entries to the set, but then can't make matching decision based on that set.
That is just wrong -- all set backends support lookups (else they would not be very useful). The failure comes from an explicit rejection in nft_lookup.c.
Looking at the history, it seems like NFT_SET_EVAL used to mean 'set contains expressions' (aka. "is a meter"), for instance something like
nft add rule ip filter input meter example { ip saddr limit rate 10/second } or nft add rule ip filter input meter example { ip saddr counter }
The actual meaning of NFT_SET_EVAL however, is 'set can be updated from the packet path'.
'meters' and packet-path insertions into sets, such as 'add @set { ip saddr }' use exactly the same kernel code (nft_dynset.c) and thus require a set backend that provides the ->update() function.
The only set that provides this also is the only one that has the NFT_SET_EVAL feature flag.
Removing the wrong check makes the above example work. While at it, also fix the flag check during set instantiation to allow supported combinations only.
Fixes: 8aeff920dcc9b3f ("netfilter: nf_tables: add stateful object reference to set elements") Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_tables_api.c | 7 +++++-- net/netfilter/nft_lookup.c | 3 --- 2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 8e4cdae2c4f14..4d8714d78192c 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3521,8 +3521,11 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk, NFT_SET_OBJECT)) return -EINVAL; /* Only one of these operations is supported */ - if ((flags & (NFT_SET_MAP | NFT_SET_EVAL | NFT_SET_OBJECT)) == - (NFT_SET_MAP | NFT_SET_EVAL | NFT_SET_OBJECT)) + if ((flags & (NFT_SET_MAP | NFT_SET_OBJECT)) == + (NFT_SET_MAP | NFT_SET_OBJECT)) + return -EOPNOTSUPP; + if ((flags & (NFT_SET_EVAL | NFT_SET_OBJECT)) == + (NFT_SET_EVAL | NFT_SET_OBJECT)) return -EOPNOTSUPP; }
diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c index c0560bf3c31bd..660bad688e2bc 100644 --- a/net/netfilter/nft_lookup.c +++ b/net/netfilter/nft_lookup.c @@ -73,9 +73,6 @@ static int nft_lookup_init(const struct nft_ctx *ctx, if (IS_ERR(set)) return PTR_ERR(set);
- if (set->flags & NFT_SET_EVAL) - return -EOPNOTSUPP; - priv->sreg = nft_parse_register(tb[NFTA_LOOKUP_SREG]); err = nft_validate_register_load(priv->sreg, set->klen); if (err < 0)