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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 u8 sreg_key;
20 u8 sreg_data;
21 bool invert;
22 bool expr;
23 u8 num_exprs;
24 u64 timeout;
25 struct nft_expr *expr_array[NFT_SET_EXPR_MAX];
26 struct nft_set_binding binding;
27};
28
29static int nft_dynset_expr_setup(const struct nft_dynset *priv,
30 const struct nft_set_ext *ext)
31{
32 struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext);
33 struct nft_expr *expr;
34 int i;
35
36 for (i = 0; i < priv->num_exprs; i++) {
37 expr = nft_setelem_expr_at(elem_expr, elem_expr->size);
38 if (nft_expr_clone(expr, priv->expr_array[i]) < 0)
39 return -1;
40
41 elem_expr->size += priv->expr_array[i]->ops->size;
42 }
43
44 return 0;
45}
46
47static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
48 struct nft_regs *regs)
49{
50 const struct nft_dynset *priv = nft_expr_priv(expr);
51 struct nft_set_ext *ext;
52 u64 timeout;
53 void *elem;
54
55 if (!atomic_add_unless(&set->nelems, 1, set->size))
56 return NULL;
57
58 timeout = priv->timeout ? : set->timeout;
59 elem = nft_set_elem_init(set, &priv->tmpl,
60 ®s->data[priv->sreg_key], NULL,
61 ®s->data[priv->sreg_data],
62 timeout, 0, GFP_ATOMIC);
63 if (elem == NULL)
64 goto err1;
65
66 ext = nft_set_elem_ext(set, elem);
67 if (priv->num_exprs && nft_dynset_expr_setup(priv, ext) < 0)
68 goto err2;
69
70 return elem;
71
72err2:
73 nft_set_elem_destroy(set, elem, false);
74err1:
75 if (set->size)
76 atomic_dec(&set->nelems);
77 return NULL;
78}
79
80void nft_dynset_eval(const struct nft_expr *expr,
81 struct nft_regs *regs, const struct nft_pktinfo *pkt)
82{
83 const struct nft_dynset *priv = nft_expr_priv(expr);
84 struct nft_set *set = priv->set;
85 const struct nft_set_ext *ext;
86 u64 timeout;
87
88 if (priv->op == NFT_DYNSET_OP_DELETE) {
89 set->ops->delete(set, ®s->data[priv->sreg_key]);
90 return;
91 }
92
93 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
94 expr, regs, &ext)) {
95 if (priv->op == NFT_DYNSET_OP_UPDATE &&
96 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
97 timeout = priv->timeout ? : set->timeout;
98 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
99 }
100
101 nft_set_elem_update_expr(ext, regs, pkt);
102
103 if (priv->invert)
104 regs->verdict.code = NFT_BREAK;
105 return;
106 }
107
108 if (!priv->invert)
109 regs->verdict.code = NFT_BREAK;
110}
111
112static void nft_dynset_ext_add_expr(struct nft_dynset *priv)
113{
114 u8 size = 0;
115 int i;
116
117 for (i = 0; i < priv->num_exprs; i++)
118 size += priv->expr_array[i]->ops->size;
119
120 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPRESSIONS,
121 sizeof(struct nft_set_elem_expr) + size);
122}
123
124static struct nft_expr *
125nft_dynset_expr_alloc(const struct nft_ctx *ctx, const struct nft_set *set,
126 const struct nlattr *attr, int pos)
127{
128 struct nft_expr *expr;
129 int err;
130
131 expr = nft_set_elem_expr_alloc(ctx, set, attr);
132 if (IS_ERR(expr))
133 return expr;
134
135 if (set->exprs[pos] && set->exprs[pos]->ops != expr->ops) {
136 err = -EOPNOTSUPP;
137 goto err_dynset_expr;
138 }
139
140 return expr;
141
142err_dynset_expr:
143 nft_expr_destroy(ctx, expr);
144 return ERR_PTR(err);
145}
146
147static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
148 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
149 .len = NFT_SET_MAXNAMELEN - 1 },
150 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
151 [NFTA_DYNSET_OP] = { .type = NLA_U32 },
152 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
153 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
154 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
155 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
156 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
157 [NFTA_DYNSET_EXPRESSIONS] = { .type = NLA_NESTED },
158};
159
160static int nft_dynset_init(const struct nft_ctx *ctx,
161 const struct nft_expr *expr,
162 const struct nlattr * const tb[])
163{
164 struct nftables_pernet *nft_net = nft_pernet(ctx->net);
165 struct nft_dynset *priv = nft_expr_priv(expr);
166 u8 genmask = nft_genmask_next(ctx->net);
167 struct nft_set *set;
168 u64 timeout;
169 int err, i;
170
171 lockdep_assert_held(&nft_net->commit_mutex);
172
173 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
174 tb[NFTA_DYNSET_OP] == NULL ||
175 tb[NFTA_DYNSET_SREG_KEY] == NULL)
176 return -EINVAL;
177
178 if (tb[NFTA_DYNSET_FLAGS]) {
179 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
180 if (flags & ~(NFT_DYNSET_F_INV | NFT_DYNSET_F_EXPR))
181 return -EOPNOTSUPP;
182 if (flags & NFT_DYNSET_F_INV)
183 priv->invert = true;
184 if (flags & NFT_DYNSET_F_EXPR)
185 priv->expr = true;
186 }
187
188 set = nft_set_lookup_global(ctx->net, ctx->table,
189 tb[NFTA_DYNSET_SET_NAME],
190 tb[NFTA_DYNSET_SET_ID], genmask);
191 if (IS_ERR(set))
192 return PTR_ERR(set);
193
194 if (set->ops->update == NULL)
195 return -EOPNOTSUPP;
196
197 if (set->flags & NFT_SET_CONSTANT)
198 return -EBUSY;
199
200 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
201 if (priv->op > NFT_DYNSET_OP_DELETE)
202 return -EOPNOTSUPP;
203
204 timeout = 0;
205 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
206 if (!(set->flags & NFT_SET_TIMEOUT))
207 return -EOPNOTSUPP;
208
209 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
210 if (err)
211 return err;
212 }
213
214 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
215 set->klen);
216 if (err < 0)
217 return err;
218
219 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
220 if (!(set->flags & NFT_SET_MAP))
221 return -EOPNOTSUPP;
222 if (set->dtype == NFT_DATA_VERDICT)
223 return -EOPNOTSUPP;
224
225 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA],
226 &priv->sreg_data, set->dlen);
227 if (err < 0)
228 return err;
229 } else if (set->flags & NFT_SET_MAP)
230 return -EINVAL;
231
232 if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) &&
233 !(set->flags & NFT_SET_EVAL))
234 return -EINVAL;
235
236 if (tb[NFTA_DYNSET_EXPR]) {
237 struct nft_expr *dynset_expr;
238
239 dynset_expr = nft_dynset_expr_alloc(ctx, set,
240 tb[NFTA_DYNSET_EXPR], 0);
241 if (IS_ERR(dynset_expr))
242 return PTR_ERR(dynset_expr);
243
244 priv->num_exprs++;
245 priv->expr_array[0] = dynset_expr;
246
247 if (set->num_exprs > 1 ||
248 (set->num_exprs == 1 &&
249 dynset_expr->ops != set->exprs[0]->ops)) {
250 err = -EOPNOTSUPP;
251 goto err_expr_free;
252 }
253 } else if (tb[NFTA_DYNSET_EXPRESSIONS]) {
254 struct nft_expr *dynset_expr;
255 struct nlattr *tmp;
256 int left;
257
258 if (!priv->expr)
259 return -EINVAL;
260
261 i = 0;
262 nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) {
263 if (i == NFT_SET_EXPR_MAX) {
264 err = -E2BIG;
265 goto err_expr_free;
266 }
267 if (nla_type(tmp) != NFTA_LIST_ELEM) {
268 err = -EINVAL;
269 goto err_expr_free;
270 }
271 dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i);
272 if (IS_ERR(dynset_expr)) {
273 err = PTR_ERR(dynset_expr);
274 goto err_expr_free;
275 }
276 priv->expr_array[i] = dynset_expr;
277 priv->num_exprs++;
278
279 if (set->num_exprs &&
280 dynset_expr->ops != set->exprs[i]->ops) {
281 err = -EOPNOTSUPP;
282 goto err_expr_free;
283 }
284 i++;
285 }
286 if (set->num_exprs && set->num_exprs != i) {
287 err = -EOPNOTSUPP;
288 goto err_expr_free;
289 }
290 } else if (set->num_exprs > 0) {
291 err = nft_set_elem_expr_clone(ctx, set, priv->expr_array);
292 if (err < 0)
293 return err;
294
295 priv->num_exprs = set->num_exprs;
296 }
297
298 nft_set_ext_prepare(&priv->tmpl);
299 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
300 if (set->flags & NFT_SET_MAP)
301 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
302
303 if (priv->num_exprs)
304 nft_dynset_ext_add_expr(priv);
305
306 if (set->flags & NFT_SET_TIMEOUT) {
307 if (timeout || set->timeout) {
308 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
309 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
310 }
311 }
312
313 priv->timeout = timeout;
314
315 err = nf_tables_bind_set(ctx, set, &priv->binding);
316 if (err < 0)
317 goto err_expr_free;
318
319 if (set->size == 0)
320 set->size = 0xffff;
321
322 priv->set = set;
323 return 0;
324
325err_expr_free:
326 for (i = 0; i < priv->num_exprs; i++)
327 nft_expr_destroy(ctx, priv->expr_array[i]);
328 return err;
329}
330
331static void nft_dynset_deactivate(const struct nft_ctx *ctx,
332 const struct nft_expr *expr,
333 enum nft_trans_phase phase)
334{
335 struct nft_dynset *priv = nft_expr_priv(expr);
336
337 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
338}
339
340static void nft_dynset_activate(const struct nft_ctx *ctx,
341 const struct nft_expr *expr)
342{
343 struct nft_dynset *priv = nft_expr_priv(expr);
344
345 priv->set->use++;
346}
347
348static void nft_dynset_destroy(const struct nft_ctx *ctx,
349 const struct nft_expr *expr)
350{
351 struct nft_dynset *priv = nft_expr_priv(expr);
352 int i;
353
354 for (i = 0; i < priv->num_exprs; i++)
355 nft_expr_destroy(ctx, priv->expr_array[i]);
356
357 nf_tables_destroy_set(ctx, priv->set);
358}
359
360static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
361{
362 const struct nft_dynset *priv = nft_expr_priv(expr);
363 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
364 int i;
365
366 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
367 goto nla_put_failure;
368 if (priv->set->flags & NFT_SET_MAP &&
369 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
370 goto nla_put_failure;
371 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
372 goto nla_put_failure;
373 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
374 goto nla_put_failure;
375 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
376 nf_jiffies64_to_msecs(priv->timeout),
377 NFTA_DYNSET_PAD))
378 goto nla_put_failure;
379 if (priv->set->num_exprs == 0) {
380 if (priv->num_exprs == 1) {
381 if (nft_expr_dump(skb, NFTA_DYNSET_EXPR,
382 priv->expr_array[0]))
383 goto nla_put_failure;
384 } else if (priv->num_exprs > 1) {
385 struct nlattr *nest;
386
387 nest = nla_nest_start_noflag(skb, NFTA_DYNSET_EXPRESSIONS);
388 if (!nest)
389 goto nla_put_failure;
390
391 for (i = 0; i < priv->num_exprs; i++) {
392 if (nft_expr_dump(skb, NFTA_LIST_ELEM,
393 priv->expr_array[i]))
394 goto nla_put_failure;
395 }
396 nla_nest_end(skb, nest);
397 }
398 }
399 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
400 goto nla_put_failure;
401 return 0;
402
403nla_put_failure:
404 return -1;
405}
406
407static const struct nft_expr_ops nft_dynset_ops = {
408 .type = &nft_dynset_type,
409 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
410 .eval = nft_dynset_eval,
411 .init = nft_dynset_init,
412 .destroy = nft_dynset_destroy,
413 .activate = nft_dynset_activate,
414 .deactivate = nft_dynset_deactivate,
415 .dump = nft_dynset_dump,
416 .reduce = NFT_REDUCE_READONLY,
417};
418
419struct nft_expr_type nft_dynset_type __read_mostly = {
420 .name = "dynset",
421 .ops = &nft_dynset_ops,
422 .policy = nft_dynset_policy,
423 .maxattr = NFTA_DYNSET_MAX,
424 .owner = THIS_MODULE,
425};
426
