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