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