path: root/net
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authorFlorian Westphal <fw@strlen.de>2019-09-19 16:56:44 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2019-09-20 10:20:02 +0200
commitacab713177377d9e0889c46bac7ff0cfb9a90c4d (patch)
treeea501691efad62ef9ebdc228c23e56f31909f16c /net
parentff175d0b0eab99f512b9afdb571f0ed18b63f533 (diff)
netfilter: nf_tables: allow lookups in dynamic sets
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>
Diffstat (limited to 'net')
2 files changed, 5 insertions, 5 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4a5d6ef2b706..6dc46f9b5f7b 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3562,8 +3562,11 @@ 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)

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