diff options
Diffstat (limited to 'net/netfilter/nft_quota.c')
-rw-r--r-- | net/netfilter/nft_quota.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/net/netfilter/nft_quota.c b/net/netfilter/nft_quota.c new file mode 100644 index 000000000000..c00104c07095 --- /dev/null +++ b/net/netfilter/nft_quota.c @@ -0,0 +1,121 @@ +/* + * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/atomic.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> + +struct nft_quota { + u64 quota; + bool invert; + atomic64_t remain; +}; + +static inline bool nft_overquota(struct nft_quota *priv, + const struct nft_pktinfo *pkt) +{ + return atomic64_sub_return(pkt->skb->len, &priv->remain) < 0; +} + +static void nft_quota_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_quota *priv = nft_expr_priv(expr); + + if (nft_overquota(priv, pkt) ^ priv->invert) + regs->verdict.code = NFT_BREAK; +} + +static const struct nla_policy nft_quota_policy[NFTA_QUOTA_MAX + 1] = { + [NFTA_QUOTA_BYTES] = { .type = NLA_U64 }, + [NFTA_QUOTA_FLAGS] = { .type = NLA_U32 }, +}; + +static int nft_quota_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_quota *priv = nft_expr_priv(expr); + u32 flags = 0; + u64 quota; + + if (!tb[NFTA_QUOTA_BYTES]) + return -EINVAL; + + quota = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_BYTES])); + if (quota > S64_MAX) + return -EOVERFLOW; + + if (tb[NFTA_QUOTA_FLAGS]) { + flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS])); + if (flags & ~NFT_QUOTA_F_INV) + return -EINVAL; + } + + priv->quota = quota; + priv->invert = (flags & NFT_QUOTA_F_INV) ? true : false; + atomic64_set(&priv->remain, quota); + + return 0; +} + +static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_quota *priv = nft_expr_priv(expr); + u32 flags = priv->invert ? NFT_QUOTA_F_INV : 0; + + if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(priv->quota), + NFTA_QUOTA_PAD) || + nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags))) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_quota_type; +static const struct nft_expr_ops nft_quota_ops = { + .type = &nft_quota_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_quota)), + .eval = nft_quota_eval, + .init = nft_quota_init, + .dump = nft_quota_dump, +}; + +static struct nft_expr_type nft_quota_type __read_mostly = { + .name = "quota", + .ops = &nft_quota_ops, + .policy = nft_quota_policy, + .maxattr = NFTA_QUOTA_MAX, + .flags = NFT_EXPR_STATEFUL, + .owner = THIS_MODULE, +}; + +static int __init nft_quota_module_init(void) +{ + return nft_register_expr(&nft_quota_type); +} + +static void __exit nft_quota_module_exit(void) +{ + nft_unregister_expr(&nft_quota_type); +} + +module_init(nft_quota_module_init); +module_exit(nft_quota_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_ALIAS_NFT_EXPR("quota"); |