// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2016 Pablo Neira Ayuso */ #include #include #include #include #include #include #include #include struct nft_quota { atomic64_t quota; unsigned long flags; atomic64_t consumed; }; static inline bool nft_overquota(struct nft_quota *priv, const struct sk_buff *skb) { return atomic64_add_return(skb->len, &priv->consumed) >= atomic64_read(&priv->quota); } static inline bool nft_quota_invert(struct nft_quota *priv) { return priv->flags & NFT_QUOTA_F_INV; } static inline void nft_quota_do_eval(struct nft_quota *priv, struct nft_regs *regs, const struct nft_pktinfo *pkt) { if (nft_overquota(priv, pkt->skb) ^ nft_quota_invert(priv)) 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 }, [NFTA_QUOTA_CONSUMED] = { .type = NLA_U64 }, }; #define NFT_QUOTA_DEPLETED_BIT 1 /* From NFT_QUOTA_F_DEPLETED. */ static void nft_quota_obj_eval(struct nft_object *obj, struct nft_regs *regs, const struct nft_pktinfo *pkt) { struct nft_quota *priv = nft_obj_data(obj); bool overquota; overquota = nft_overquota(priv, pkt->skb); if (overquota ^ nft_quota_invert(priv)) regs->verdict.code = NFT_BREAK; if (overquota && !test_and_set_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags)) nft_obj_notify(nft_net(pkt), obj->key.table, obj, 0, 0, NFT_MSG_NEWOBJ, 0, nft_pf(pkt), 0, GFP_ATOMIC); } static int nft_quota_do_init(const struct nlattr * const tb[], struct nft_quota *priv) { unsigned long flags = 0; u64 quota, consumed = 0; 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_CONSUMED]) { consumed = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_CONSUMED])); if (consumed > quota) return -EINVAL; } if (tb[NFTA_QUOTA_FLAGS]) { flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS])); if (flags & ~NFT_QUOTA_F_INV) return -EINVAL; if (flags & NFT_QUOTA_F_DEPLETED) return -EOPNOTSUPP; } atomic64_set(&priv->quota, quota); priv->flags = flags; atomic64_set(&priv->consumed, consumed); return 0; } static int nft_quota_obj_init(const struct nft_ctx *ctx, const struct nlattr * const tb[], struct nft_object *obj) { struct nft_quota *priv = nft_obj_data(obj); return nft_quota_do_init(tb, priv); } static void nft_quota_obj_update(struct nft_object *obj, struct nft_object *newobj) { struct nft_quota *newpriv = nft_obj_data(newobj); struct nft_quota *priv = nft_obj_data(obj); u64 newquota; newquota = atomic64_read(&newpriv->quota); atomic64_set(&priv->quota, newquota); priv->flags = newpriv->flags; } static int nft_quota_do_dump(struct sk_buff *skb, struct nft_quota *priv, bool reset) { u64 consumed, consumed_cap, quota; u32 flags = priv->flags; /* Since we inconditionally increment consumed quota for each packet * that we see, don't go over the quota boundary in what we send to * userspace. */ consumed = atomic64_read(&priv->consumed); quota = atomic64_read(&priv->quota); if (consumed >= quota) { consumed_cap = quota; flags |= NFT_QUOTA_F_DEPLETED; } else { consumed_cap = consumed; } if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(quota), NFTA_QUOTA_PAD) || nla_put_be64(skb, NFTA_QUOTA_CONSUMED, cpu_to_be64(consumed_cap), NFTA_QUOTA_PAD) || nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags))) goto nla_put_failure; if (reset) { atomic64_sub(consumed, &priv->consumed); clear_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags); } return 0; nla_put_failure: return -1; } static int nft_quota_obj_dump(struct sk_buff *skb, struct nft_object *obj, bool reset) { struct nft_quota *priv = nft_obj_data(obj); return nft_quota_do_dump(skb, priv, reset); } static struct nft_object_type nft_quota_obj_type; static const struct nft_object_ops nft_quota_obj_ops = { .type = &nft_quota_obj_type, .size = sizeof(struct nft_quota), .init = nft_quota_obj_init, .eval = nft_quota_obj_eval, .dump = nft_quota_obj_dump, .update = nft_quota_obj_update, }; static struct nft_object_type nft_quota_obj_type __read_mostly = { .type = NFT_OBJECT_QUOTA, .ops = &nft_quota_obj_ops, .maxattr = NFTA_QUOTA_MAX, .policy = nft_quota_policy, .owner = THIS_MODULE, }; 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); nft_quota_do_eval(priv, regs, pkt); } 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); return nft_quota_do_init(tb, priv); } static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr) { struct nft_quota *priv = nft_expr_priv(expr); return nft_quota_do_dump(skb, priv, false); } 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) { int err; err = nft_register_obj(&nft_quota_obj_type); if (err < 0) return err; err = nft_register_expr(&nft_quota_type); if (err < 0) goto err1; return 0; err1: nft_unregister_obj(&nft_quota_obj_type); return err; } static void __exit nft_quota_module_exit(void) { nft_unregister_expr(&nft_quota_type); nft_unregister_obj(&nft_quota_obj_type); } module_init(nft_quota_module_init); module_exit(nft_quota_module_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Pablo Neira Ayuso "); MODULE_ALIAS_NFT_EXPR("quota"); MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_QUOTA); MODULE_DESCRIPTION("Netfilter nftables quota module");