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6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/init.h>
9#include <linux/netlink.h>
10#include <linux/netfilter.h>
11#include <linux/netfilter/nf_tables.h>
12#include <net/netfilter/nf_tables.h>
13#include <net/netfilter/nf_tables_core.h>
14
15struct nft_dynset {
16 struct nft_set *set;
17 struct nft_set_ext_tmpl tmpl;
18 enum nft_dynset_ops op:8;
19 enum nft_registers sreg_key:8;
20 enum nft_registers sreg_data:8;
21 bool invert;
22 u64 timeout;
23 struct nft_expr *expr;
24 struct nft_set_binding binding;
25};
26
27static int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
28{
29 int err;
30
31 if (src->ops->clone) {
32 dst->ops = src->ops;
33 err = src->ops->clone(dst, src);
34 if (err < 0)
35 return err;
36 } else {
37 memcpy(dst, src, src->ops->size);
38 }
39
40 __module_get(src->ops->type->owner);
41 return 0;
42}
43
44static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
45 struct nft_regs *regs)
46{
47 const struct nft_dynset *priv = nft_expr_priv(expr);
48 struct nft_set_ext *ext;
49 u64 timeout;
50 void *elem;
51
52 if (!atomic_add_unless(&set->nelems, 1, set->size))
53 return NULL;
54
55 timeout = priv->timeout ? : set->timeout;
56 elem = nft_set_elem_init(set, &priv->tmpl,
57 ®s->data[priv->sreg_key],
58 ®s->data[priv->sreg_data],
59 timeout, 0, GFP_ATOMIC);
60 if (elem == NULL)
61 goto err1;
62
63 ext = nft_set_elem_ext(set, elem);
64 if (priv->expr != NULL &&
65 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
66 goto err2;
67
68 return elem;
69
70err2:
71 nft_set_elem_destroy(set, elem, false);
72err1:
73 if (set->size)
74 atomic_dec(&set->nelems);
75 return NULL;
76}
77
78void nft_dynset_eval(const struct nft_expr *expr,
79 struct nft_regs *regs, const struct nft_pktinfo *pkt)
80{
81 const struct nft_dynset *priv = nft_expr_priv(expr);
82 struct nft_set *set = priv->set;
83 const struct nft_set_ext *ext;
84 const struct nft_expr *sexpr;
85 u64 timeout;
86
87 if (priv->op == NFT_DYNSET_OP_DELETE) {
88 set->ops->delete(set, ®s->data[priv->sreg_key]);
89 return;
90 }
91
92 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
93 expr, regs, &ext)) {
94 sexpr = NULL;
95 if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
96 sexpr = nft_set_ext_expr(ext);
97
98 if (priv->op == NFT_DYNSET_OP_UPDATE &&
99 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
100 timeout = priv->timeout ? : set->timeout;
101 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
102 }
103
104 if (sexpr != NULL)
105 sexpr->ops->eval(sexpr, regs, pkt);
106
107 if (priv->invert)
108 regs->verdict.code = NFT_BREAK;
109 return;
110 }
111
112 if (!priv->invert)
113 regs->verdict.code = NFT_BREAK;
114}
115
116static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
117 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
118 .len = NFT_SET_MAXNAMELEN - 1 },
119 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
120 [NFTA_DYNSET_OP] = { .type = NLA_U32 },
121 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
122 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
123 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
124 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
125 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
126};
127
128static int nft_dynset_init(const struct nft_ctx *ctx,
129 const struct nft_expr *expr,
130 const struct nlattr * const tb[])
131{
132 struct nft_dynset *priv = nft_expr_priv(expr);
133 u8 genmask = nft_genmask_next(ctx->net);
134 struct nft_set *set;
135 u64 timeout;
136 int err;
137
138 lockdep_assert_held(&ctx->net->nft.commit_mutex);
139
140 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
141 tb[NFTA_DYNSET_OP] == NULL ||
142 tb[NFTA_DYNSET_SREG_KEY] == NULL)
143 return -EINVAL;
144
145 if (tb[NFTA_DYNSET_FLAGS]) {
146 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
147
148 if (flags & ~NFT_DYNSET_F_INV)
149 return -EINVAL;
150 if (flags & NFT_DYNSET_F_INV)
151 priv->invert = true;
152 }
153
154 set = nft_set_lookup_global(ctx->net, ctx->table,
155 tb[NFTA_DYNSET_SET_NAME],
156 tb[NFTA_DYNSET_SET_ID], genmask);
157 if (IS_ERR(set))
158 return PTR_ERR(set);
159
160 if (set->ops->update == NULL)
161 return -EOPNOTSUPP;
162
163 if (set->flags & NFT_SET_CONSTANT)
164 return -EBUSY;
165
166 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
167 switch (priv->op) {
168 case NFT_DYNSET_OP_ADD:
169 case NFT_DYNSET_OP_DELETE:
170 break;
171 case NFT_DYNSET_OP_UPDATE:
172 if (!(set->flags & NFT_SET_TIMEOUT))
173 return -EOPNOTSUPP;
174 break;
175 default:
176 return -EOPNOTSUPP;
177 }
178
179 timeout = 0;
180 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
181 if (!(set->flags & NFT_SET_TIMEOUT))
182 return -EINVAL;
183 timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64(
184 tb[NFTA_DYNSET_TIMEOUT])));
185 }
186
187 priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
188 err = nft_validate_register_load(priv->sreg_key, set->klen);
189 if (err < 0)
190 return err;
191
192 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
193 if (!(set->flags & NFT_SET_MAP))
194 return -EINVAL;
195 if (set->dtype == NFT_DATA_VERDICT)
196 return -EOPNOTSUPP;
197
198 priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
199 err = nft_validate_register_load(priv->sreg_data, set->dlen);
200 if (err < 0)
201 return err;
202 } else if (set->flags & NFT_SET_MAP)
203 return -EINVAL;
204
205 if (tb[NFTA_DYNSET_EXPR] != NULL) {
206 if (!(set->flags & NFT_SET_EVAL))
207 return -EINVAL;
208
209 priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
210 if (IS_ERR(priv->expr))
211 return PTR_ERR(priv->expr);
212
213 err = -EOPNOTSUPP;
214 if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
215 goto err1;
216
217 if (priv->expr->ops->type->flags & NFT_EXPR_GC) {
218 if (set->flags & NFT_SET_TIMEOUT)
219 goto err1;
220 if (!set->ops->gc_init)
221 goto err1;
222 set->ops->gc_init(set);
223 }
224 }
225
226 nft_set_ext_prepare(&priv->tmpl);
227 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
228 if (set->flags & NFT_SET_MAP)
229 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
230 if (priv->expr != NULL)
231 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
232 priv->expr->ops->size);
233 if (set->flags & NFT_SET_TIMEOUT) {
234 if (timeout || set->timeout)
235 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
236 }
237
238 priv->timeout = timeout;
239
240 err = nf_tables_bind_set(ctx, set, &priv->binding);
241 if (err < 0)
242 goto err1;
243
244 if (set->size == 0)
245 set->size = 0xffff;
246
247 priv->set = set;
248 return 0;
249
250err1:
251 if (priv->expr != NULL)
252 nft_expr_destroy(ctx, priv->expr);
253 return err;
254}
255
256static void nft_dynset_deactivate(const struct nft_ctx *ctx,
257 const struct nft_expr *expr,
258 enum nft_trans_phase phase)
259{
260 struct nft_dynset *priv = nft_expr_priv(expr);
261
262 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
263}
264
265static void nft_dynset_activate(const struct nft_ctx *ctx,
266 const struct nft_expr *expr)
267{
268 struct nft_dynset *priv = nft_expr_priv(expr);
269
270 priv->set->use++;
271}
272
273static void nft_dynset_destroy(const struct nft_ctx *ctx,
274 const struct nft_expr *expr)
275{
276 struct nft_dynset *priv = nft_expr_priv(expr);
277
278 if (priv->expr != NULL)
279 nft_expr_destroy(ctx, priv->expr);
280
281 nf_tables_destroy_set(ctx, priv->set);
282}
283
284static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
285{
286 const struct nft_dynset *priv = nft_expr_priv(expr);
287 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
288
289 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
290 goto nla_put_failure;
291 if (priv->set->flags & NFT_SET_MAP &&
292 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
293 goto nla_put_failure;
294 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
295 goto nla_put_failure;
296 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
297 goto nla_put_failure;
298 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
299 cpu_to_be64(jiffies_to_msecs(priv->timeout)),
300 NFTA_DYNSET_PAD))
301 goto nla_put_failure;
302 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
303 goto nla_put_failure;
304 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
305 goto nla_put_failure;
306 return 0;
307
308nla_put_failure:
309 return -1;
310}
311
312static const struct nft_expr_ops nft_dynset_ops = {
313 .type = &nft_dynset_type,
314 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
315 .eval = nft_dynset_eval,
316 .init = nft_dynset_init,
317 .destroy = nft_dynset_destroy,
318 .activate = nft_dynset_activate,
319 .deactivate = nft_dynset_deactivate,
320 .dump = nft_dynset_dump,
321};
322
323struct nft_expr_type nft_dynset_type __read_mostly = {
324 .name = "dynset",
325 .ops = &nft_dynset_ops,
326 .policy = nft_dynset_policy,
327 .maxattr = NFTA_DYNSET_MAX,
328 .owner = THIS_MODULE,
329};
330
