[PATCH 06/17] netfilter: nft_limit: allow to invert matching criteria
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2016-01-08 14:03:12
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This patch allows you to invert the ratelimit matching criteria, so you can match packets over the ratelimit. This is required to support what hashlimit does. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- include/uapi/linux/netfilter/nf_tables.h | 6 ++++++ net/netfilter/nft_limit.c | 16 +++++++++++++--- 2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index b48a3ab..22043ce 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h@@ -780,6 +780,10 @@ enum nft_limit_type { NFT_LIMIT_PKT_BYTES }; +enum nft_limit_flags { + NFT_LIMIT_F_INV = (1 << 0), +}; + /** * enum nft_limit_attributes - nf_tables limit expression netlink attributes *
@@ -787,6 +791,7 @@ enum nft_limit_type { * @NFTA_LIMIT_UNIT: refill unit (NLA_U64) * @NFTA_LIMIT_BURST: burst (NLA_U32) * @NFTA_LIMIT_TYPE: type of limit (NLA_U32: enum nft_limit_type) + * @NFTA_LIMIT_FLAGS: flags (NLA_U32: enum nft_limit_flags) */ enum nft_limit_attributes { NFTA_LIMIT_UNSPEC,
@@ -794,6 +799,7 @@ enum nft_limit_attributes { NFTA_LIMIT_UNIT, NFTA_LIMIT_BURST, NFTA_LIMIT_TYPE, + NFTA_LIMIT_FLAGS, __NFTA_LIMIT_MAX }; #define NFTA_LIMIT_MAX (__NFTA_LIMIT_MAX - 1)
diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c
index 5d67938..99d1857 100644
--- a/net/netfilter/nft_limit.c
+++ b/net/netfilter/nft_limit.c@@ -26,6 +26,7 @@ struct nft_limit { u64 rate; u64 nsecs; u32 burst; + bool invert; }; static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost)
@@ -44,11 +45,11 @@ static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost) if (delta >= 0) { limit->tokens = delta; spin_unlock_bh(&limit_lock); - return false; + return limit->invert; } limit->tokens = tokens; spin_unlock_bh(&limit_lock); - return true; + return !limit->invert; } static int nft_limit_init(struct nft_limit *limit,
@@ -78,6 +79,12 @@ static int nft_limit_init(struct nft_limit *limit, limit->rate = rate; } + if (tb[NFTA_LIMIT_FLAGS]) { + u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS])); + + if (flags & NFT_LIMIT_F_INV) + limit->invert = true; + } limit->last = ktime_get_ns(); return 0;
@@ -86,13 +93,15 @@ static int nft_limit_init(struct nft_limit *limit, static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit, enum nft_limit_type type) { + u32 flags = limit->invert ? NFT_LIMIT_F_INV : 0; u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC); u64 rate = limit->rate - limit->burst; if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(rate)) || nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs)) || nla_put_be32(skb, NFTA_LIMIT_BURST, htonl(limit->burst)) || - nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type))) + nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type)) || + nla_put_be32(skb, NFTA_LIMIT_FLAGS, htonl(flags))) goto nla_put_failure; return 0;
@@ -120,6 +129,7 @@ static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = { [NFTA_LIMIT_UNIT] = { .type = NLA_U64 }, [NFTA_LIMIT_BURST] = { .type = NLA_U32 }, [NFTA_LIMIT_TYPE] = { .type = NLA_U32 }, + [NFTA_LIMIT_FLAGS] = { .type = NLA_U32 }, }; static int nft_limit_pkts_init(const struct nft_ctx *ctx,
--
2.1.4