From f8d3a6bc76011bb86d2515ebd0b3b300641f2f8c Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 2 Aug 2015 14:16:42 +0200 Subject: [PATCH] netfilter: nft_limit: factor out shared code with per-byte limiting This patch prepares the introduction of per-byte limiting. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_limit.c | 86 ++++++++++++++++++++++++--------------- 1 file changed, 53 insertions(+), 33 deletions(-) diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c index c79703e5baad..c4d1b1b75b8f 100644 --- a/net/netfilter/nft_limit.c +++ b/net/netfilter/nft_limit.c @@ -27,65 +27,54 @@ struct nft_limit { u64 nsecs; }; -static void nft_limit_pkts_eval(const struct nft_expr *expr, - struct nft_regs *regs, - const struct nft_pktinfo *pkt) +static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost) { - struct nft_limit *priv = nft_expr_priv(expr); - u64 now, tokens, cost = div_u64(priv->nsecs, priv->rate); + u64 now, tokens; s64 delta; spin_lock_bh(&limit_lock); now = ktime_get_ns(); - tokens = priv->tokens + now - priv->last; - if (tokens > priv->tokens_max) - tokens = priv->tokens_max; + tokens = limit->tokens + now - limit->last; + if (tokens > limit->tokens_max) + tokens = limit->tokens_max; - priv->last = now; + limit->last = now; delta = tokens - cost; if (delta >= 0) { - priv->tokens = delta; + limit->tokens = delta; spin_unlock_bh(&limit_lock); - return; + return false; } - priv->tokens = tokens; + limit->tokens = tokens; spin_unlock_bh(&limit_lock); - - regs->verdict.code = NFT_BREAK; + return true; } -static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = { - [NFTA_LIMIT_RATE] = { .type = NLA_U64 }, - [NFTA_LIMIT_UNIT] = { .type = NLA_U64 }, -}; - -static int nft_limit_init(const struct nft_ctx *ctx, - const struct nft_expr *expr, +static int nft_limit_init(struct nft_limit *limit, const struct nlattr * const tb[]) { - struct nft_limit *priv = nft_expr_priv(expr); u64 unit; if (tb[NFTA_LIMIT_RATE] == NULL || tb[NFTA_LIMIT_UNIT] == NULL) return -EINVAL; - priv->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE])); + limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE])); unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT])); - priv->nsecs = unit * NSEC_PER_SEC; - if (priv->rate == 0 || priv->nsecs < unit) + limit->nsecs = unit * NSEC_PER_SEC; + if (limit->rate == 0 || limit->nsecs < unit) return -EOVERFLOW; - priv->tokens = priv->tokens_max = priv->nsecs; - priv->last = ktime_get_ns(); + limit->tokens = limit->tokens_max = limit->nsecs; + limit->last = ktime_get_ns(); + return 0; } -static int nft_limit_dump(struct sk_buff *skb, const struct nft_expr *expr) +static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit) { - const struct nft_limit *priv = nft_expr_priv(expr); - u64 secs = div_u64(priv->nsecs, NSEC_PER_SEC); + u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC); - if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(priv->rate)) || + if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(limit->rate)) || nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs))) goto nla_put_failure; return 0; @@ -94,13 +83,44 @@ nla_put_failure: return -1; } +static void nft_limit_pkts_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_limit *priv = nft_expr_priv(expr); + + if (nft_limit_eval(priv, div_u64(priv->nsecs, priv->rate))) + regs->verdict.code = NFT_BREAK; +} + +static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = { + [NFTA_LIMIT_RATE] = { .type = NLA_U64 }, + [NFTA_LIMIT_UNIT] = { .type = NLA_U64 }, +}; + +static int nft_limit_pkts_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_limit *priv = nft_expr_priv(expr); + + return nft_limit_init(priv, tb); +} + +static int nft_limit_pkts_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_limit *priv = nft_expr_priv(expr); + + return nft_limit_dump(skb, priv); +} + static struct nft_expr_type nft_limit_type; static const struct nft_expr_ops nft_limit_pkts_ops = { .type = &nft_limit_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_limit)), .eval = nft_limit_pkts_eval, - .init = nft_limit_init, - .dump = nft_limit_dump, + .init = nft_limit_pkts_init, + .dump = nft_limit_pkts_dump, }; static struct nft_expr_type nft_limit_type __read_mostly = { -- 2.34.1