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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>
10
11struct nft_last_priv {
12 unsigned long last_jiffies;
13 unsigned int last_set;
14};
15
16static const struct nla_policy nft_last_policy[NFTA_LAST_MAX + 1] = {
17 [NFTA_LAST_SET] = { .type = NLA_U32 },
18 [NFTA_LAST_MSECS] = { .type = NLA_U64 },
19};
20
21static int nft_last_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
22 const struct nlattr * const tb[])
23{
24 struct nft_last_priv *priv = nft_expr_priv(expr);
25 u64 last_jiffies;
26 u32 last_set = 0;
27 int err;
28
29 if (tb[NFTA_LAST_SET]) {
30 last_set = ntohl(nla_get_be32(tb[NFTA_LAST_SET]));
31 if (last_set == 1)
32 priv->last_set = 1;
33 }
34
35 if (last_set && tb[NFTA_LAST_MSECS]) {
36 err = nf_msecs_to_jiffies64(tb[NFTA_LAST_MSECS], &last_jiffies);
37 if (err < 0)
38 return err;
39
40 priv->last_jiffies = jiffies - (unsigned long)last_jiffies;
41 }
42
43 return 0;
44}
45
46static void nft_last_eval(const struct nft_expr *expr,
47 struct nft_regs *regs, const struct nft_pktinfo *pkt)
48{
49 struct nft_last_priv *priv = nft_expr_priv(expr);
50
51 if (READ_ONCE(priv->last_jiffies) != jiffies)
52 WRITE_ONCE(priv->last_jiffies, jiffies);
53 if (READ_ONCE(priv->last_set) == 0)
54 WRITE_ONCE(priv->last_set, 1);
55}
56
57static int nft_last_dump(struct sk_buff *skb, const struct nft_expr *expr)
58{
59 struct nft_last_priv *priv = nft_expr_priv(expr);
60 unsigned long last_jiffies = READ_ONCE(priv->last_jiffies);
61 u32 last_set = READ_ONCE(priv->last_set);
62 __be64 msecs;
63
64 if (time_before(jiffies, last_jiffies)) {
65 WRITE_ONCE(priv->last_set, 0);
66 last_set = 0;
67 }
68
69 if (last_set)
70 msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies);
71 else
72 msecs = 0;
73
74 if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) ||
75 nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD))
76 goto nla_put_failure;
77
78 return 0;
79
80nla_put_failure:
81 return -1;
82}
83
84static const struct nft_expr_ops nft_last_ops = {
85 .type = &nft_last_type,
86 .size = NFT_EXPR_SIZE(sizeof(struct nft_last_priv)),
87 .eval = nft_last_eval,
88 .init = nft_last_init,
89 .dump = nft_last_dump,
90};
91
92struct nft_expr_type nft_last_type __read_mostly = {
93 .name = "last",
94 .ops = &nft_last_ops,
95 .policy = nft_last_policy,
96 .maxattr = NFTA_LAST_MAX,
97 .flags = NFT_EXPR_STATEFUL,
98 .owner = THIS_MODULE,
99};
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>
10
11struct nft_last {
12 unsigned long jiffies;
13 unsigned int set;
14};
15
16struct nft_last_priv {
17 struct nft_last *last;
18};
19
20static 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 },
23};
24
25static int nft_last_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
26 const struct nlattr * const tb[])
27{
28 struct nft_last_priv *priv = nft_expr_priv(expr);
29 struct nft_last *last;
30 u64 last_jiffies;
31 int err;
32
33 last = kzalloc(sizeof(*last), GFP_KERNEL_ACCOUNT);
34 if (!last)
35 return -ENOMEM;
36
37 if (tb[NFTA_LAST_SET])
38 last->set = ntohl(nla_get_be32(tb[NFTA_LAST_SET]));
39
40 if (last->set && tb[NFTA_LAST_MSECS]) {
41 err = nf_msecs_to_jiffies64(tb[NFTA_LAST_MSECS], &last_jiffies);
42 if (err < 0)
43 goto err;
44
45 last->jiffies = jiffies - (unsigned long)last_jiffies;
46 }
47 priv->last = last;
48
49 return 0;
50err:
51 kfree(last);
52
53 return err;
54}
55
56static void nft_last_eval(const struct nft_expr *expr,
57 struct nft_regs *regs, const struct nft_pktinfo *pkt)
58{
59 struct nft_last_priv *priv = nft_expr_priv(expr);
60 struct nft_last *last = priv->last;
61
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);
66}
67
68static int nft_last_dump(struct sk_buff *skb,
69 const struct nft_expr *expr, bool reset)
70{
71 struct nft_last_priv *priv = nft_expr_priv(expr);
72 struct nft_last *last = priv->last;
73 unsigned long last_jiffies = READ_ONCE(last->jiffies);
74 u32 last_set = READ_ONCE(last->set);
75 __be64 msecs;
76
77 if (time_before(jiffies, last_jiffies)) {
78 WRITE_ONCE(last->set, 0);
79 last_set = 0;
80 }
81
82 if (last_set)
83 msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies);
84 else
85 msecs = 0;
86
87 if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) ||
88 nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD))
89 goto nla_put_failure;
90
91 return 0;
92
93nla_put_failure:
94 return -1;
95}
96
97static void nft_last_destroy(const struct nft_ctx *ctx,
98 const struct nft_expr *expr)
99{
100 struct nft_last_priv *priv = nft_expr_priv(expr);
101
102 kfree(priv->last);
103}
104
105static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src)
106{
107 struct nft_last_priv *priv_dst = nft_expr_priv(dst);
108 struct nft_last_priv *priv_src = nft_expr_priv(src);
109
110 priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC);
111 if (!priv_dst->last)
112 return -ENOMEM;
113
114 priv_dst->last->set = priv_src->last->set;
115 priv_dst->last->jiffies = priv_src->last->jiffies;
116
117 return 0;
118}
119
120static const struct nft_expr_ops nft_last_ops = {
121 .type = &nft_last_type,
122 .size = NFT_EXPR_SIZE(sizeof(struct nft_last_priv)),
123 .eval = nft_last_eval,
124 .init = nft_last_init,
125 .destroy = nft_last_destroy,
126 .clone = nft_last_clone,
127 .dump = nft_last_dump,
128 .reduce = NFT_REDUCE_READONLY,
129};
130
131struct nft_expr_type nft_last_type __read_mostly = {
132 .name = "last",
133 .ops = &nft_last_ops,
134 .policy = nft_last_policy,
135 .maxattr = NFTA_LAST_MAX,
136 .flags = NFT_EXPR_STATEFUL,
137 .owner = THIS_MODULE,
138};