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6#include <linux/kernel.h>
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/atomic.h>
10#include <linux/netlink.h>
11#include <linux/netfilter.h>
12#include <linux/netfilter/nf_tables.h>
13#include <net/netfilter/nf_tables.h>
14
15struct nft_quota {
16 atomic64_t quota;
17 unsigned long flags;
18 atomic64_t consumed;
19};
20
21static inline bool nft_overquota(struct nft_quota *priv,
22 const struct sk_buff *skb)
23{
24 return atomic64_add_return(skb->len, &priv->consumed) >=
25 atomic64_read(&priv->quota);
26}
27
28static inline bool nft_quota_invert(struct nft_quota *priv)
29{
30 return priv->flags & NFT_QUOTA_F_INV;
31}
32
33static inline void nft_quota_do_eval(struct nft_quota *priv,
34 struct nft_regs *regs,
35 const struct nft_pktinfo *pkt)
36{
37 if (nft_overquota(priv, pkt->skb) ^ nft_quota_invert(priv))
38 regs->verdict.code = NFT_BREAK;
39}
40
41static const struct nla_policy nft_quota_policy[NFTA_QUOTA_MAX + 1] = {
42 [NFTA_QUOTA_BYTES] = { .type = NLA_U64 },
43 [NFTA_QUOTA_FLAGS] = { .type = NLA_U32 },
44 [NFTA_QUOTA_CONSUMED] = { .type = NLA_U64 },
45};
46
47#define NFT_QUOTA_DEPLETED_BIT 1
48
49static void nft_quota_obj_eval(struct nft_object *obj,
50 struct nft_regs *regs,
51 const struct nft_pktinfo *pkt)
52{
53 struct nft_quota *priv = nft_obj_data(obj);
54 bool overquota;
55
56 overquota = nft_overquota(priv, pkt->skb);
57 if (overquota ^ nft_quota_invert(priv))
58 regs->verdict.code = NFT_BREAK;
59
60 if (overquota &&
61 !test_and_set_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags))
62 nft_obj_notify(nft_net(pkt), obj->key.table, obj, 0, 0,
63 NFT_MSG_NEWOBJ, nft_pf(pkt), 0, GFP_ATOMIC);
64}
65
66static int nft_quota_do_init(const struct nlattr * const tb[],
67 struct nft_quota *priv)
68{
69 unsigned long flags = 0;
70 u64 quota, consumed = 0;
71
72 if (!tb[NFTA_QUOTA_BYTES])
73 return -EINVAL;
74
75 quota = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_BYTES]));
76 if (quota > S64_MAX)
77 return -EOVERFLOW;
78
79 if (tb[NFTA_QUOTA_CONSUMED]) {
80 consumed = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_CONSUMED]));
81 if (consumed > quota)
82 return -EINVAL;
83 }
84
85 if (tb[NFTA_QUOTA_FLAGS]) {
86 flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS]));
87 if (flags & ~NFT_QUOTA_F_INV)
88 return -EINVAL;
89 if (flags & NFT_QUOTA_F_DEPLETED)
90 return -EOPNOTSUPP;
91 }
92
93 atomic64_set(&priv->quota, quota);
94 priv->flags = flags;
95 atomic64_set(&priv->consumed, consumed);
96
97 return 0;
98}
99
100static int nft_quota_obj_init(const struct nft_ctx *ctx,
101 const struct nlattr * const tb[],
102 struct nft_object *obj)
103{
104 struct nft_quota *priv = nft_obj_data(obj);
105
106 return nft_quota_do_init(tb, priv);
107}
108
109static void nft_quota_obj_update(struct nft_object *obj,
110 struct nft_object *newobj)
111{
112 struct nft_quota *newpriv = nft_obj_data(newobj);
113 struct nft_quota *priv = nft_obj_data(obj);
114 u64 newquota;
115
116 newquota = atomic64_read(&newpriv->quota);
117 atomic64_set(&priv->quota, newquota);
118 priv->flags = newpriv->flags;
119}
120
121static int nft_quota_do_dump(struct sk_buff *skb, struct nft_quota *priv,
122 bool reset)
123{
124 u64 consumed, consumed_cap, quota;
125 u32 flags = priv->flags;
126
127
128
129
130
131 consumed = atomic64_read(&priv->consumed);
132 quota = atomic64_read(&priv->quota);
133 if (consumed >= quota) {
134 consumed_cap = quota;
135 flags |= NFT_QUOTA_F_DEPLETED;
136 } else {
137 consumed_cap = consumed;
138 }
139
140 if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(quota),
141 NFTA_QUOTA_PAD) ||
142 nla_put_be64(skb, NFTA_QUOTA_CONSUMED, cpu_to_be64(consumed_cap),
143 NFTA_QUOTA_PAD) ||
144 nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags)))
145 goto nla_put_failure;
146
147 if (reset) {
148 atomic64_sub(consumed, &priv->consumed);
149 clear_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags);
150 }
151 return 0;
152
153nla_put_failure:
154 return -1;
155}
156
157static int nft_quota_obj_dump(struct sk_buff *skb, struct nft_object *obj,
158 bool reset)
159{
160 struct nft_quota *priv = nft_obj_data(obj);
161
162 return nft_quota_do_dump(skb, priv, reset);
163}
164
165static struct nft_object_type nft_quota_obj_type;
166static const struct nft_object_ops nft_quota_obj_ops = {
167 .type = &nft_quota_obj_type,
168 .size = sizeof(struct nft_quota),
169 .init = nft_quota_obj_init,
170 .eval = nft_quota_obj_eval,
171 .dump = nft_quota_obj_dump,
172 .update = nft_quota_obj_update,
173};
174
175static struct nft_object_type nft_quota_obj_type __read_mostly = {
176 .type = NFT_OBJECT_QUOTA,
177 .ops = &nft_quota_obj_ops,
178 .maxattr = NFTA_QUOTA_MAX,
179 .policy = nft_quota_policy,
180 .owner = THIS_MODULE,
181};
182
183static void nft_quota_eval(const struct nft_expr *expr,
184 struct nft_regs *regs,
185 const struct nft_pktinfo *pkt)
186{
187 struct nft_quota *priv = nft_expr_priv(expr);
188
189 nft_quota_do_eval(priv, regs, pkt);
190}
191
192static int nft_quota_init(const struct nft_ctx *ctx,
193 const struct nft_expr *expr,
194 const struct nlattr * const tb[])
195{
196 struct nft_quota *priv = nft_expr_priv(expr);
197
198 return nft_quota_do_init(tb, priv);
199}
200
201static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr)
202{
203 struct nft_quota *priv = nft_expr_priv(expr);
204
205 return nft_quota_do_dump(skb, priv, false);
206}
207
208static struct nft_expr_type nft_quota_type;
209static const struct nft_expr_ops nft_quota_ops = {
210 .type = &nft_quota_type,
211 .size = NFT_EXPR_SIZE(sizeof(struct nft_quota)),
212 .eval = nft_quota_eval,
213 .init = nft_quota_init,
214 .dump = nft_quota_dump,
215};
216
217static struct nft_expr_type nft_quota_type __read_mostly = {
218 .name = "quota",
219 .ops = &nft_quota_ops,
220 .policy = nft_quota_policy,
221 .maxattr = NFTA_QUOTA_MAX,
222 .flags = NFT_EXPR_STATEFUL,
223 .owner = THIS_MODULE,
224};
225
226static int __init nft_quota_module_init(void)
227{
228 int err;
229
230 err = nft_register_obj(&nft_quota_obj_type);
231 if (err < 0)
232 return err;
233
234 err = nft_register_expr(&nft_quota_type);
235 if (err < 0)
236 goto err1;
237
238 return 0;
239err1:
240 nft_unregister_obj(&nft_quota_obj_type);
241 return err;
242}
243
244static void __exit nft_quota_module_exit(void)
245{
246 nft_unregister_expr(&nft_quota_type);
247 nft_unregister_obj(&nft_quota_obj_type);
248}
249
250module_init(nft_quota_module_init);
251module_exit(nft_quota_module_exit);
252
253MODULE_LICENSE("GPL");
254MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
255MODULE_ALIAS_NFT_EXPR("quota");
256MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_QUOTA);
257MODULE_DESCRIPTION("Netfilter nftables quota module");
258
