1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include <linux/netlink.h>
6 #include <linux/netfilter.h>
7 #include <linux/netfilter/nf_tables.h>
8 #include <net/netfilter/nf_tables_core.h>
9 #include <net/netfilter/nf_tables.h>
12 unsigned long jiffies;
16 struct nft_last_priv {
17 struct nft_last *last;
20 static const struct nla_policy nft_last_policy[NFTA_LAST_MAX + 1] = {
21 [NFTA_LAST_SET] = { .type = NLA_U32 },
22 [NFTA_LAST_MSECS] = { .type = NLA_U64 },
25 static int nft_last_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
26 const struct nlattr * const tb[])
28 struct nft_last_priv *priv = nft_expr_priv(expr);
29 struct nft_last *last;
33 last = kzalloc(sizeof(*last), GFP_KERNEL_ACCOUNT);
37 if (tb[NFTA_LAST_SET])
38 last->set = ntohl(nla_get_be32(tb[NFTA_LAST_SET]));
40 if (last->set && tb[NFTA_LAST_MSECS]) {
41 err = nf_msecs_to_jiffies64(tb[NFTA_LAST_MSECS], &last_jiffies);
45 last->jiffies = jiffies - (unsigned long)last_jiffies;
56 static void nft_last_eval(const struct nft_expr *expr,
57 struct nft_regs *regs, const struct nft_pktinfo *pkt)
59 struct nft_last_priv *priv = nft_expr_priv(expr);
60 struct nft_last *last = priv->last;
62 if (READ_ONCE(last->jiffies) != jiffies)
63 WRITE_ONCE(last->jiffies, jiffies);
64 if (READ_ONCE(last->set) == 0)
65 WRITE_ONCE(last->set, 1);
68 static int nft_last_dump(struct sk_buff *skb, const struct nft_expr *expr)
70 struct nft_last_priv *priv = nft_expr_priv(expr);
71 struct nft_last *last = priv->last;
72 unsigned long last_jiffies = READ_ONCE(last->jiffies);
73 u32 last_set = READ_ONCE(last->set);
76 if (time_before(jiffies, last_jiffies)) {
77 WRITE_ONCE(last->set, 0);
82 msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies);
86 if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) ||
87 nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD))
96 static void nft_last_destroy(const struct nft_ctx *ctx,
97 const struct nft_expr *expr)
99 struct nft_last_priv *priv = nft_expr_priv(expr);
104 static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src)
106 struct nft_last_priv *priv_dst = nft_expr_priv(dst);
108 priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC);
115 static const struct nft_expr_ops nft_last_ops = {
116 .type = &nft_last_type,
117 .size = NFT_EXPR_SIZE(sizeof(struct nft_last_priv)),
118 .eval = nft_last_eval,
119 .init = nft_last_init,
120 .destroy = nft_last_destroy,
121 .clone = nft_last_clone,
122 .dump = nft_last_dump,
123 .reduce = NFT_REDUCE_READONLY,
126 struct nft_expr_type nft_last_type __read_mostly = {
128 .ops = &nft_last_ops,
129 .policy = nft_last_policy,
130 .maxattr = NFTA_LAST_MAX,
131 .flags = NFT_EXPR_STATEFUL,
132 .owner = THIS_MODULE,