blob: 9cfb5a7aaeb8d235de91ce19ba8305a2f2515057 [file] [log] [blame]
From 687fa64cea6afbbe5856f08ddcc7242be2262d1f Mon Sep 17 00:00:00 2001
From: Florian Westphal <>
Date: Thu, 19 Sep 2019 16:56:44 +0200
Subject: [PATCH] netfilter: nf_tables: allow lookups in dynamic sets
commit acab713177377d9e0889c46bac7ff0cfb9a90c4d upstream.
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 }
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 <>
Signed-off-by: Pablo Neira Ayuso <>
Signed-off-by: Paul Gortmaker <>
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 8e4cdae2c4f1..4d8714d78192 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,
return -EINVAL;
/* Only one of these operations is supported */
- if ((flags & (NFT_SET_MAP | NFT_SET_EVAL | NFT_SET_OBJECT)) ==
+ if ((flags & (NFT_SET_MAP | NFT_SET_OBJECT)) ==
+ return -EOPNOTSUPP;
+ if ((flags & (NFT_SET_EVAL | NFT_SET_OBJECT)) ==
diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c
index c0560bf3c31b..660bad688e2b 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)