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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015 Patrick McHardy <kaber@trash.net>
4 */
5
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 switch (priv->op) {
202 case NFT_DYNSET_OP_ADD:
203 case NFT_DYNSET_OP_DELETE:
204 break;
205 case NFT_DYNSET_OP_UPDATE:
206 if (!(set->flags & NFT_SET_TIMEOUT))
207 return -EOPNOTSUPP;
208 break;
209 default:
210 return -EOPNOTSUPP;
211 }
212
213 timeout = 0;
214 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
215 if (!(set->flags & NFT_SET_TIMEOUT))
216 return -EOPNOTSUPP;
217
218 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
219 if (err)
220 return err;
221 }
222
223 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
224 set->klen);
225 if (err < 0)
226 return err;
227
228 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
229 if (!(set->flags & NFT_SET_MAP))
230 return -EOPNOTSUPP;
231 if (set->dtype == NFT_DATA_VERDICT)
232 return -EOPNOTSUPP;
233
234 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA],
235 &priv->sreg_data, set->dlen);
236 if (err < 0)
237 return err;
238 } else if (set->flags & NFT_SET_MAP)
239 return -EINVAL;
240
241 if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) &&
242 !(set->flags & NFT_SET_EVAL))
243 return -EINVAL;
244
245 if (tb[NFTA_DYNSET_EXPR]) {
246 struct nft_expr *dynset_expr;
247
248 dynset_expr = nft_dynset_expr_alloc(ctx, set,
249 tb[NFTA_DYNSET_EXPR], 0);
250 if (IS_ERR(dynset_expr))
251 return PTR_ERR(dynset_expr);
252
253 priv->num_exprs++;
254 priv->expr_array[0] = dynset_expr;
255
256 if (set->num_exprs > 1 ||
257 (set->num_exprs == 1 &&
258 dynset_expr->ops != set->exprs[0]->ops)) {
259 err = -EOPNOTSUPP;
260 goto err_expr_free;
261 }
262 } else if (tb[NFTA_DYNSET_EXPRESSIONS]) {
263 struct nft_expr *dynset_expr;
264 struct nlattr *tmp;
265 int left;
266
267 if (!priv->expr)
268 return -EINVAL;
269
270 i = 0;
271 nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) {
272 if (i == NFT_SET_EXPR_MAX) {
273 err = -E2BIG;
274 goto err_expr_free;
275 }
276 if (nla_type(tmp) != NFTA_LIST_ELEM) {
277 err = -EINVAL;
278 goto err_expr_free;
279 }
280 dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i);
281 if (IS_ERR(dynset_expr)) {
282 err = PTR_ERR(dynset_expr);
283 goto err_expr_free;
284 }
285 priv->expr_array[i] = dynset_expr;
286 priv->num_exprs++;
287
288 if (set->num_exprs &&
289 dynset_expr->ops != set->exprs[i]->ops) {
290 err = -EOPNOTSUPP;
291 goto err_expr_free;
292 }
293 i++;
294 }
295 if (set->num_exprs && set->num_exprs != i) {
296 err = -EOPNOTSUPP;
297 goto err_expr_free;
298 }
299 } else if (set->num_exprs > 0) {
300 err = nft_set_elem_expr_clone(ctx, set, priv->expr_array);
301 if (err < 0)
302 return err;
303
304 priv->num_exprs = set->num_exprs;
305 }
306
307 nft_set_ext_prepare(&priv->tmpl);
308 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
309 if (set->flags & NFT_SET_MAP)
310 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
311
312 if (priv->num_exprs)
313 nft_dynset_ext_add_expr(priv);
314
315 if (set->flags & NFT_SET_TIMEOUT) {
316 if (timeout || set->timeout) {
317 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
318 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
319 }
320 }
321
322 priv->timeout = timeout;
323
324 err = nf_tables_bind_set(ctx, set, &priv->binding);
325 if (err < 0)
326 goto err_expr_free;
327
328 if (set->size == 0)
329 set->size = 0xffff;
330
331 priv->set = set;
332 return 0;
333
334err_expr_free:
335 for (i = 0; i < priv->num_exprs; i++)
336 nft_expr_destroy(ctx, priv->expr_array[i]);
337 return err;
338}
339
340static void nft_dynset_deactivate(const struct nft_ctx *ctx,
341 const struct nft_expr *expr,
342 enum nft_trans_phase phase)
343{
344 struct nft_dynset *priv = nft_expr_priv(expr);
345
346 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
347}
348
349static void nft_dynset_activate(const struct nft_ctx *ctx,
350 const struct nft_expr *expr)
351{
352 struct nft_dynset *priv = nft_expr_priv(expr);
353
354 priv->set->use++;
355}
356
357static void nft_dynset_destroy(const struct nft_ctx *ctx,
358 const struct nft_expr *expr)
359{
360 struct nft_dynset *priv = nft_expr_priv(expr);
361 int i;
362
363 for (i = 0; i < priv->num_exprs; i++)
364 nft_expr_destroy(ctx, priv->expr_array[i]);
365
366 nf_tables_destroy_set(ctx, priv->set);
367}
368
369static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
370{
371 const struct nft_dynset *priv = nft_expr_priv(expr);
372 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
373 int i;
374
375 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
376 goto nla_put_failure;
377 if (priv->set->flags & NFT_SET_MAP &&
378 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
379 goto nla_put_failure;
380 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
381 goto nla_put_failure;
382 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
383 goto nla_put_failure;
384 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
385 nf_jiffies64_to_msecs(priv->timeout),
386 NFTA_DYNSET_PAD))
387 goto nla_put_failure;
388 if (priv->set->num_exprs == 0) {
389 if (priv->num_exprs == 1) {
390 if (nft_expr_dump(skb, NFTA_DYNSET_EXPR,
391 priv->expr_array[0]))
392 goto nla_put_failure;
393 } else if (priv->num_exprs > 1) {
394 struct nlattr *nest;
395
396 nest = nla_nest_start_noflag(skb, NFTA_DYNSET_EXPRESSIONS);
397 if (!nest)
398 goto nla_put_failure;
399
400 for (i = 0; i < priv->num_exprs; i++) {
401 if (nft_expr_dump(skb, NFTA_LIST_ELEM,
402 priv->expr_array[i]))
403 goto nla_put_failure;
404 }
405 nla_nest_end(skb, nest);
406 }
407 }
408 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
409 goto nla_put_failure;
410 return 0;
411
412nla_put_failure:
413 return -1;
414}
415
416static const struct nft_expr_ops nft_dynset_ops = {
417 .type = &nft_dynset_type,
418 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
419 .eval = nft_dynset_eval,
420 .init = nft_dynset_init,
421 .destroy = nft_dynset_destroy,
422 .activate = nft_dynset_activate,
423 .deactivate = nft_dynset_deactivate,
424 .dump = nft_dynset_dump,
425};
426
427struct nft_expr_type nft_dynset_type __read_mostly = {
428 .name = "dynset",
429 .ops = &nft_dynset_ops,
430 .policy = nft_dynset_policy,
431 .maxattr = NFTA_DYNSET_MAX,
432 .owner = THIS_MODULE,
433};