diff options
Diffstat (limited to 'net/netfilter/nft_limit.c')
-rw-r--r-- | net/netfilter/nft_limit.c | 188 |
1 files changed, 150 insertions, 38 deletions
diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c index 435c1cc..5d67938 100644 --- a/net/netfilter/nft_limit.c +++ b/net/netfilter/nft_limit.c @@ -20,63 +20,79 @@ static DEFINE_SPINLOCK(limit_lock); struct nft_limit { + u64 last; u64 tokens; + u64 tokens_max; u64 rate; - u64 unit; - unsigned long stamp; + u64 nsecs; + u32 burst; }; -static void nft_limit_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; + s64 delta; spin_lock_bh(&limit_lock); - if (time_after_eq(jiffies, priv->stamp)) { - priv->tokens = priv->rate; - priv->stamp = jiffies + priv->unit * HZ; - } - - if (priv->tokens >= 1) { - priv->tokens--; + now = ktime_get_ns(); + tokens = limit->tokens + now - limit->last; + if (tokens > limit->tokens_max) + tokens = limit->tokens_max; + + limit->last = now; + delta = tokens - cost; + if (delta >= 0) { + limit->tokens = delta; spin_unlock_bh(&limit_lock); - return; + return false; } + 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])); - priv->unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT])); - priv->stamp = jiffies + priv->unit * HZ; - priv->tokens = priv->rate; + limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE])); + unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT])); + limit->nsecs = unit * NSEC_PER_SEC; + if (limit->rate == 0 || limit->nsecs < unit) + return -EOVERFLOW; + limit->tokens = limit->tokens_max = limit->nsecs; + + if (tb[NFTA_LIMIT_BURST]) { + u64 rate; + + limit->burst = ntohl(nla_get_be32(tb[NFTA_LIMIT_BURST])); + + rate = limit->rate + limit->burst; + if (rate < limit->rate) + return -EOVERFLOW; + + limit->rate = rate; + } + 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, + enum nft_limit_type type) { - const struct nft_limit *priv = nft_expr_priv(expr); + 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(priv->rate))) - goto nla_put_failure; - if (nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(priv->unit))) + 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))) goto nla_put_failure; return 0; @@ -84,18 +100,114 @@ nla_put_failure: return -1; } +struct nft_limit_pkts { + struct nft_limit limit; + u64 cost; +}; + +static void nft_limit_pkts_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_limit_pkts *priv = nft_expr_priv(expr); + + if (nft_limit_eval(&priv->limit, priv->cost)) + 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 }, + [NFTA_LIMIT_BURST] = { .type = NLA_U32 }, + [NFTA_LIMIT_TYPE] = { .type = NLA_U32 }, +}; + +static int nft_limit_pkts_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_limit_pkts *priv = nft_expr_priv(expr); + int err; + + err = nft_limit_init(&priv->limit, tb); + if (err < 0) + return err; + + priv->cost = div_u64(priv->limit.nsecs, priv->limit.rate); + return 0; +} + +static int nft_limit_pkts_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_limit_pkts *priv = nft_expr_priv(expr); + + return nft_limit_dump(skb, &priv->limit, NFT_LIMIT_PKTS); +} + static struct nft_expr_type nft_limit_type; -static const struct nft_expr_ops nft_limit_ops = { +static const struct nft_expr_ops nft_limit_pkts_ops = { + .type = &nft_limit_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_limit_pkts)), + .eval = nft_limit_pkts_eval, + .init = nft_limit_pkts_init, + .dump = nft_limit_pkts_dump, +}; + +static void nft_limit_pkt_bytes_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_limit *priv = nft_expr_priv(expr); + u64 cost = div_u64(priv->nsecs * pkt->skb->len, priv->rate); + + if (nft_limit_eval(priv, cost)) + regs->verdict.code = NFT_BREAK; +} + +static int nft_limit_pkt_bytes_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_pkt_bytes_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, NFT_LIMIT_PKT_BYTES); +} + +static const struct nft_expr_ops nft_limit_pkt_bytes_ops = { .type = &nft_limit_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_limit)), - .eval = nft_limit_eval, - .init = nft_limit_init, - .dump = nft_limit_dump, + .eval = nft_limit_pkt_bytes_eval, + .init = nft_limit_pkt_bytes_init, + .dump = nft_limit_pkt_bytes_dump, }; +static const struct nft_expr_ops * +nft_limit_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + if (tb[NFTA_LIMIT_TYPE] == NULL) + return &nft_limit_pkts_ops; + + switch (ntohl(nla_get_be32(tb[NFTA_LIMIT_TYPE]))) { + case NFT_LIMIT_PKTS: + return &nft_limit_pkts_ops; + case NFT_LIMIT_PKT_BYTES: + return &nft_limit_pkt_bytes_ops; + } + return ERR_PTR(-EOPNOTSUPP); +} + static struct nft_expr_type nft_limit_type __read_mostly = { .name = "limit", - .ops = &nft_limit_ops, + .select_ops = nft_limit_select_ops, .policy = nft_limit_policy, .maxattr = NFTA_LIMIT_MAX, .flags = NFT_EXPR_STATEFUL, |