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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015 Patrick McHardy <[email protected]>
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:1,
23 override_exprs:1;
24 u8 num_exprs;
25 u64 timeout;
26 struct nft_expr *expr_array[NFT_SET_EXPR_MAX];
27 struct nft_set_binding binding;
28};
29
30static int nft_dynset_expr_setup(const struct nft_dynset *priv,
31 const struct nft_set_ext *ext)
32{
33 struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext);
34 struct nft_ctx ctx = {
35 .net = read_pnet(&priv->set->net),
36 .family = priv->set->table->family,
37 };
38 struct nft_expr *expr;
39 int i;
40
41 for (i = 0; i < priv->num_exprs; i++) {
42 expr = nft_setelem_expr_at(elem_expr, elem_expr->size);
43 if (nft_expr_clone(expr, priv->expr_array[i], GFP_ATOMIC) < 0)
44 goto err_out;
45
46 elem_expr->size += priv->expr_array[i]->ops->size;
47 }
48
49 return 0;
50err_out:
51 nft_set_elem_expr_destroy(&ctx, elem_expr);
52
53 return -1;
54}
55
56struct nft_elem_priv *nft_dynset_new(struct nft_set *set,
57 const struct nft_expr *expr,
58 struct nft_regs *regs)
59{
60 const struct nft_dynset *priv = nft_expr_priv(expr);
61 struct nft_set_ext *ext;
62 void *elem_priv;
63 u64 timeout;
64
65 if (!atomic_add_unless(&set->nelems, 1, set->size))
66 return NULL;
67
68 timeout = priv->timeout ? : READ_ONCE(set->timeout);
69 elem_priv = nft_set_elem_init(set, &priv->tmpl,
70 &regs->data[priv->sreg_key], NULL,
71 &regs->data[priv->sreg_data],
72 timeout, 0, GFP_ATOMIC);
73 if (IS_ERR(elem_priv))
74 goto err1;
75
76 ext = nft_set_elem_ext(set, elem_priv);
77 if (priv->num_exprs && nft_dynset_expr_setup(priv, ext) < 0)
78 goto err2;
79
80 return elem_priv;
81
82err2:
83 nft_set_elem_destroy(set, elem_priv, false);
84err1:
85 if (set->size)
86 atomic_dec(&set->nelems);
87 return NULL;
88}
89
90void nft_dynset_eval(const struct nft_expr *expr,
91 struct nft_regs *regs, const struct nft_pktinfo *pkt)
92{
93 const struct nft_dynset *priv = nft_expr_priv(expr);
94 struct nft_set *set = priv->set;
95 const struct nft_set_ext *ext;
96 u64 timeout;
97
98 if (priv->op == NFT_DYNSET_OP_DELETE) {
99 set->ops->delete(set, &regs->data[priv->sreg_key]);
100 return;
101 }
102
103 ext = set->ops->update(set, &regs->data[priv->sreg_key], expr, regs);
104 if (ext) {
105 if (priv->op == NFT_DYNSET_OP_UPDATE &&
106 nft_set_ext_exists(ext, NFT_SET_EXT_TIMEOUT) &&
107 READ_ONCE(nft_set_ext_timeout(ext)->timeout) != 0) {
108 timeout = priv->timeout ? : READ_ONCE(set->timeout);
109 WRITE_ONCE(nft_set_ext_timeout(ext)->expiration, get_jiffies_64() + timeout);
110 }
111
112 nft_set_elem_update_expr(ext, regs, pkt);
113
114 if (priv->invert)
115 regs->verdict.code = NFT_BREAK;
116 return;
117 }
118
119 if (!priv->invert)
120 regs->verdict.code = NFT_BREAK;
121}
122
123static void nft_dynset_ext_add_expr(struct nft_dynset *priv)
124{
125 u8 size = 0;
126 int i;
127
128 for (i = 0; i < priv->num_exprs; i++)
129 size += priv->expr_array[i]->ops->size;
130
131 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPRESSIONS,
132 sizeof(struct nft_set_elem_expr) + size);
133}
134
135static struct nft_expr *
136nft_dynset_expr_alloc(const struct nft_ctx *ctx, const struct nft_set *set,
137 const struct nlattr *attr, int pos)
138{
139 struct nft_expr *expr;
140 int err;
141
142 expr = nft_set_elem_expr_alloc(ctx, set, attr);
143 if (IS_ERR(expr))
144 return expr;
145
146 if (set->exprs[pos] && set->exprs[pos]->ops != expr->ops) {
147 err = -EOPNOTSUPP;
148 goto err_dynset_expr;
149 }
150
151 return expr;
152
153err_dynset_expr:
154 nft_expr_destroy(ctx, expr);
155 return ERR_PTR(err);
156}
157
158static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
159 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
160 .len = NFT_SET_MAXNAMELEN - 1 },
161 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
162 [NFTA_DYNSET_OP] = NLA_POLICY_MAX(NLA_BE32, 255),
163 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
164 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
165 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
166 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
167 [NFTA_DYNSET_FLAGS] = NLA_POLICY_MASK(NLA_BE32, NFT_DYNSET_F_INV |
168 NFT_DYNSET_F_EXPR),
169 [NFTA_DYNSET_EXPRESSIONS] = { .type = NLA_NESTED },
170};
171
172static int nft_dynset_init(const struct nft_ctx *ctx,
173 const struct nft_expr *expr,
174 const struct nlattr * const tb[])
175{
176 struct nftables_pernet *nft_net = nft_pernet(ctx->net);
177 struct nft_dynset *priv = nft_expr_priv(expr);
178 u8 genmask = nft_genmask_next(ctx->net);
179 struct nft_set *set;
180 u64 timeout;
181 int err, i;
182
183 lockdep_assert_held(&nft_net->commit_mutex);
184
185 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
186 tb[NFTA_DYNSET_OP] == NULL ||
187 tb[NFTA_DYNSET_SREG_KEY] == NULL)
188 return -EINVAL;
189
190 if (tb[NFTA_DYNSET_FLAGS]) {
191 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
192 if (flags & ~(NFT_DYNSET_F_INV | NFT_DYNSET_F_EXPR))
193 return -EOPNOTSUPP;
194 if (flags & NFT_DYNSET_F_INV)
195 priv->invert = true;
196 if (flags & NFT_DYNSET_F_EXPR)
197 priv->expr = true;
198 }
199
200 set = nft_set_lookup_global(ctx->net, ctx->table,
201 tb[NFTA_DYNSET_SET_NAME],
202 tb[NFTA_DYNSET_SET_ID], genmask);
203 if (IS_ERR(set))
204 return PTR_ERR(set);
205
206 if (set->flags & NFT_SET_OBJECT)
207 return -EOPNOTSUPP;
208
209 if (set->ops->update == NULL)
210 return -EOPNOTSUPP;
211
212 if (set->flags & NFT_SET_CONSTANT)
213 return -EBUSY;
214
215 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
216 if (priv->op > NFT_DYNSET_OP_DELETE)
217 return -EOPNOTSUPP;
218
219 timeout = 0;
220 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
221 if (!(set->flags & NFT_SET_TIMEOUT))
222 return -EOPNOTSUPP;
223
224 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
225 if (err)
226 return err;
227 }
228
229 err = nft_parse_register_load(ctx, tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
230 set->klen);
231 if (err < 0)
232 return err;
233
234 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
235 if (!(set->flags & NFT_SET_MAP))
236 return -EOPNOTSUPP;
237 if (set->dtype == NFT_DATA_VERDICT)
238 return -EOPNOTSUPP;
239
240 err = nft_parse_register_load(ctx, tb[NFTA_DYNSET_SREG_DATA],
241 &priv->sreg_data, set->dlen);
242 if (err < 0)
243 return err;
244 } else if (set->flags & NFT_SET_MAP)
245 return -EINVAL;
246
247 if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) &&
248 !(set->flags & NFT_SET_EVAL))
249 return -EINVAL;
250
251 if (tb[NFTA_DYNSET_EXPR]) {
252 struct nft_expr *dynset_expr;
253
254 dynset_expr = nft_dynset_expr_alloc(ctx, set,
255 tb[NFTA_DYNSET_EXPR], 0);
256 if (IS_ERR(dynset_expr))
257 return PTR_ERR(dynset_expr);
258
259 priv->num_exprs++;
260 priv->expr_array[0] = dynset_expr;
261 priv->override_exprs = true;
262
263 if (set->num_exprs > 1 ||
264 (set->num_exprs == 1 &&
265 dynset_expr->ops != set->exprs[0]->ops)) {
266 err = -EOPNOTSUPP;
267 goto err_expr_free;
268 }
269 } else if (tb[NFTA_DYNSET_EXPRESSIONS]) {
270 struct nft_expr *dynset_expr;
271 struct nlattr *tmp;
272 int left;
273
274 if (!priv->expr)
275 return -EINVAL;
276
277 i = 0;
278 nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) {
279 if (i == NFT_SET_EXPR_MAX) {
280 err = -E2BIG;
281 goto err_expr_free;
282 }
283 if (nla_type(tmp) != NFTA_LIST_ELEM) {
284 err = -EINVAL;
285 goto err_expr_free;
286 }
287 dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i);
288 if (IS_ERR(dynset_expr)) {
289 err = PTR_ERR(dynset_expr);
290 goto err_expr_free;
291 }
292 priv->expr_array[i] = dynset_expr;
293 priv->num_exprs++;
294 priv->override_exprs = true;
295
296 if (set->num_exprs) {
297 if (i >= set->num_exprs) {
298 err = -EINVAL;
299 goto err_expr_free;
300 }
301 if (dynset_expr->ops != set->exprs[i]->ops) {
302 err = -EOPNOTSUPP;
303 goto err_expr_free;
304 }
305 }
306 i++;
307 }
308 if (set->num_exprs && set->num_exprs != i) {
309 err = -EOPNOTSUPP;
310 goto err_expr_free;
311 }
312 } else if (set->num_exprs > 0) {
313 for (i = 0; i < set->num_exprs; i++)
314 priv->expr_array[i] = set->exprs[i];
315
316 priv->num_exprs = set->num_exprs;
317 }
318
319 nft_set_ext_prepare(&priv->tmpl);
320 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
321 if (set->flags & NFT_SET_MAP)
322 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
323
324 if (priv->num_exprs)
325 nft_dynset_ext_add_expr(priv);
326
327 if (set->flags & NFT_SET_TIMEOUT &&
328 (timeout || READ_ONCE(set->timeout)))
329 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
330
331 priv->timeout = timeout;
332
333 err = nf_tables_bind_set(ctx, set, &priv->binding);
334 if (err < 0)
335 goto err_expr_free;
336
337 if (set->size == 0)
338 set->size = 0xffff;
339
340 priv->set = set;
341 return 0;
342
343err_expr_free:
344 if (priv->override_exprs) {
345 for (i = 0; i < priv->num_exprs; i++)
346 nft_expr_destroy(ctx, priv->expr_array[i]);
347 }
348 return err;
349}
350
351static void nft_dynset_deactivate(const struct nft_ctx *ctx,
352 const struct nft_expr *expr,
353 enum nft_trans_phase phase)
354{
355 struct nft_dynset *priv = nft_expr_priv(expr);
356
357 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
358}
359
360static void nft_dynset_activate(const struct nft_ctx *ctx,
361 const struct nft_expr *expr)
362{
363 struct nft_dynset *priv = nft_expr_priv(expr);
364
365 nf_tables_activate_set(ctx, priv->set);
366}
367
368static void nft_dynset_destroy(const struct nft_ctx *ctx,
369 const struct nft_expr *expr)
370{
371 struct nft_dynset *priv = nft_expr_priv(expr);
372 int i;
373
374 if (priv->override_exprs) {
375 for (i = 0; i < priv->num_exprs; i++)
376 nft_expr_destroy(ctx, priv->expr_array[i]);
377 }
378 nf_tables_destroy_set(ctx, priv->set);
379}
380
381static int nft_dynset_dump(struct sk_buff *skb,
382 const struct nft_expr *expr, bool reset)
383{
384 const struct nft_dynset *priv = nft_expr_priv(expr);
385 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
386 int i;
387
388 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
389 goto nla_put_failure;
390 if (priv->set->flags & NFT_SET_MAP &&
391 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
392 goto nla_put_failure;
393 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
394 goto nla_put_failure;
395 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
396 goto nla_put_failure;
397 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
398 nf_jiffies64_to_msecs(priv->timeout),
399 NFTA_DYNSET_PAD))
400 goto nla_put_failure;
401 if (priv->set->num_exprs == 0 || priv->override_exprs) {
402 if (priv->num_exprs == 1) {
403 if (nft_expr_dump(skb, NFTA_DYNSET_EXPR,
404 priv->expr_array[0], reset))
405 goto nla_put_failure;
406 } else if (priv->num_exprs > 1) {
407 struct nlattr *nest;
408
409 nest = nla_nest_start_noflag(skb, NFTA_DYNSET_EXPRESSIONS);
410 if (!nest)
411 goto nla_put_failure;
412
413 for (i = 0; i < priv->num_exprs; i++) {
414 if (nft_expr_dump(skb, NFTA_LIST_ELEM,
415 priv->expr_array[i], reset))
416 goto nla_put_failure;
417 }
418 nla_nest_end(skb, nest);
419 }
420 }
421 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
422 goto nla_put_failure;
423 return 0;
424
425nla_put_failure:
426 return -1;
427}
428
429static const struct nft_expr_ops nft_dynset_ops = {
430 .type = &nft_dynset_type,
431 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
432 .eval = nft_dynset_eval,
433 .init = nft_dynset_init,
434 .destroy = nft_dynset_destroy,
435 .activate = nft_dynset_activate,
436 .deactivate = nft_dynset_deactivate,
437 .dump = nft_dynset_dump,
438};
439
440struct nft_expr_type nft_dynset_type __read_mostly = {
441 .name = "dynset",
442 .ops = &nft_dynset_ops,
443 .policy = nft_dynset_policy,
444 .maxattr = NFTA_DYNSET_MAX,
445 .owner = THIS_MODULE,
446};