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9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/atomic.h>
13#include <linux/netlink.h>
14#include <linux/netfilter.h>
15#include <linux/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables.h>
17
18struct nft_quota {
19 u64 quota;
20 unsigned long flags;
21 atomic64_t consumed;
22};
23
24static inline bool nft_overquota(struct nft_quota *priv,
25 const struct sk_buff *skb)
26{
27 return atomic64_add_return(skb->len, &priv->consumed) >= priv->quota;
28}
29
30static inline bool nft_quota_invert(struct nft_quota *priv)
31{
32 return priv->flags & NFT_QUOTA_F_INV;
33}
34
35static inline void nft_quota_do_eval(struct nft_quota *priv,
36 struct nft_regs *regs,
37 const struct nft_pktinfo *pkt)
38{
39 if (nft_overquota(priv, pkt->skb) ^ nft_quota_invert(priv))
40 regs->verdict.code = NFT_BREAK;
41}
42
43static const struct nla_policy nft_quota_policy[NFTA_QUOTA_MAX + 1] = {
44 [NFTA_QUOTA_BYTES] = { .type = NLA_U64 },
45 [NFTA_QUOTA_FLAGS] = { .type = NLA_U32 },
46 [NFTA_QUOTA_CONSUMED] = { .type = NLA_U64 },
47};
48
49#define NFT_QUOTA_DEPLETED_BIT 1
50
51static void nft_quota_obj_eval(struct nft_object *obj,
52 struct nft_regs *regs,
53 const struct nft_pktinfo *pkt)
54{
55 struct nft_quota *priv = nft_obj_data(obj);
56 bool overquota;
57
58 overquota = nft_overquota(priv, pkt->skb);
59 if (overquota ^ nft_quota_invert(priv))
60 regs->verdict.code = NFT_BREAK;
61
62 if (overquota &&
63 !test_and_set_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags))
64 nft_obj_notify(nft_net(pkt), obj->table, obj, 0, 0,
65 NFT_MSG_NEWOBJ, nft_pf(pkt), 0, GFP_ATOMIC);
66}
67
68static int nft_quota_do_init(const struct nlattr * const tb[],
69 struct nft_quota *priv)
70{
71 unsigned long flags = 0;
72 u64 quota, consumed = 0;
73
74 if (!tb[NFTA_QUOTA_BYTES])
75 return -EINVAL;
76
77 quota = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_BYTES]));
78 if (quota > S64_MAX)
79 return -EOVERFLOW;
80
81 if (tb[NFTA_QUOTA_CONSUMED]) {
82 consumed = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_CONSUMED]));
83 if (consumed > quota)
84 return -EINVAL;
85 }
86
87 if (tb[NFTA_QUOTA_FLAGS]) {
88 flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS]));
89 if (flags & ~NFT_QUOTA_F_INV)
90 return -EINVAL;
91 if (flags & NFT_QUOTA_F_DEPLETED)
92 return -EOPNOTSUPP;
93 }
94
95 priv->quota = quota;
96 priv->flags = flags;
97 atomic64_set(&priv->consumed, consumed);
98
99 return 0;
100}
101
102static int nft_quota_obj_init(const struct nft_ctx *ctx,
103 const struct nlattr * const tb[],
104 struct nft_object *obj)
105{
106 struct nft_quota *priv = nft_obj_data(obj);
107
108 return nft_quota_do_init(tb, priv);
109}
110
111static int nft_quota_do_dump(struct sk_buff *skb, struct nft_quota *priv,
112 bool reset)
113{
114 u64 consumed, consumed_cap;
115 u32 flags = priv->flags;
116
117
118
119
120
121 consumed = atomic64_read(&priv->consumed);
122 if (consumed >= priv->quota) {
123 consumed_cap = priv->quota;
124 flags |= NFT_QUOTA_F_DEPLETED;
125 } else {
126 consumed_cap = consumed;
127 }
128
129 if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(priv->quota),
130 NFTA_QUOTA_PAD) ||
131 nla_put_be64(skb, NFTA_QUOTA_CONSUMED, cpu_to_be64(consumed_cap),
132 NFTA_QUOTA_PAD) ||
133 nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags)))
134 goto nla_put_failure;
135
136 if (reset) {
137 atomic64_sub(consumed, &priv->consumed);
138 clear_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags);
139 }
140 return 0;
141
142nla_put_failure:
143 return -1;
144}
145
146static int nft_quota_obj_dump(struct sk_buff *skb, struct nft_object *obj,
147 bool reset)
148{
149 struct nft_quota *priv = nft_obj_data(obj);
150
151 return nft_quota_do_dump(skb, priv, reset);
152}
153
154static struct nft_object_type nft_quota_obj_type;
155static const struct nft_object_ops nft_quota_obj_ops = {
156 .type = &nft_quota_obj_type,
157 .size = sizeof(struct nft_quota),
158 .init = nft_quota_obj_init,
159 .eval = nft_quota_obj_eval,
160 .dump = nft_quota_obj_dump,
161};
162
163static struct nft_object_type nft_quota_obj_type __read_mostly = {
164 .type = NFT_OBJECT_QUOTA,
165 .ops = &nft_quota_obj_ops,
166 .maxattr = NFTA_QUOTA_MAX,
167 .policy = nft_quota_policy,
168 .owner = THIS_MODULE,
169};
170
171static void nft_quota_eval(const struct nft_expr *expr,
172 struct nft_regs *regs,
173 const struct nft_pktinfo *pkt)
174{
175 struct nft_quota *priv = nft_expr_priv(expr);
176
177 nft_quota_do_eval(priv, regs, pkt);
178}
179
180static int nft_quota_init(const struct nft_ctx *ctx,
181 const struct nft_expr *expr,
182 const struct nlattr * const tb[])
183{
184 struct nft_quota *priv = nft_expr_priv(expr);
185
186 return nft_quota_do_init(tb, priv);
187}
188
189static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr)
190{
191 struct nft_quota *priv = nft_expr_priv(expr);
192
193 return nft_quota_do_dump(skb, priv, false);
194}
195
196static struct nft_expr_type nft_quota_type;
197static const struct nft_expr_ops nft_quota_ops = {
198 .type = &nft_quota_type,
199 .size = NFT_EXPR_SIZE(sizeof(struct nft_quota)),
200 .eval = nft_quota_eval,
201 .init = nft_quota_init,
202 .dump = nft_quota_dump,
203};
204
205static struct nft_expr_type nft_quota_type __read_mostly = {
206 .name = "quota",
207 .ops = &nft_quota_ops,
208 .policy = nft_quota_policy,
209 .maxattr = NFTA_QUOTA_MAX,
210 .flags = NFT_EXPR_STATEFUL,
211 .owner = THIS_MODULE,
212};
213
214static int __init nft_quota_module_init(void)
215{
216 int err;
217
218 err = nft_register_obj(&nft_quota_obj_type);
219 if (err < 0)
220 return err;
221
222 err = nft_register_expr(&nft_quota_type);
223 if (err < 0)
224 goto err1;
225
226 return 0;
227err1:
228 nft_unregister_obj(&nft_quota_obj_type);
229 return err;
230}
231
232static void __exit nft_quota_module_exit(void)
233{
234 nft_unregister_expr(&nft_quota_type);
235 nft_unregister_obj(&nft_quota_obj_type);
236}
237
238module_init(nft_quota_module_init);
239module_exit(nft_quota_module_exit);
240
241MODULE_LICENSE("GPL");
242MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
243MODULE_ALIAS_NFT_EXPR("quota");
244MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_QUOTA);
245
