diff options
author | Florian Westphal <fw@strlen.de> | 2019-09-19 16:56:44 +0200 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-09-20 10:20:02 +0200 |
commit | acab713177377d9e0889c46bac7ff0cfb9a90c4d (patch) | |
tree | ea501691efad62ef9ebdc228c23e56f31909f16c /net | |
parent | ff175d0b0eab99f512b9afdb571f0ed18b63f533 (diff) | |
download | linux-acab713177377d9e0889c46bac7ff0cfb9a90c4d.tar.bz2 |
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')
-rw-r--r-- | net/netfilter/nf_tables_api.c | 7 | ||||
-rw-r--r-- | 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 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, 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 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) |