tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 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 ? : 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
73err2:
74 nft_set_elem_destroy(set, elem_priv, false);
75err1:
76 if (set->size)
77 atomic_dec(&set->nelems);
78 return NULL;
79}
80
81void 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 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
95 expr, regs, &ext)) {
96 if (priv->op == NFT_DYNSET_OP_UPDATE &&
97 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
98 timeout = priv->timeout ? : set->timeout;
99 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
100 }
101
102 nft_set_elem_update_expr(ext, regs, pkt);
103
104 if (priv->invert)
105 regs->verdict.code = NFT_BREAK;
106 return;
107 }
108
109 if (!priv->invert)
110 regs->verdict.code = NFT_BREAK;
111}
112
113static void nft_dynset_ext_add_expr(struct nft_dynset *priv)
114{
115 u8 size = 0;
116 int i;
117
118 for (i = 0; i < priv->num_exprs; i++)
119 size += priv->expr_array[i]->ops->size;
120
121 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPRESSIONS,
122 sizeof(struct nft_set_elem_expr) + size);
123}
124
125static struct nft_expr *
126nft_dynset_expr_alloc(const struct nft_ctx *ctx, const struct nft_set *set,
127 const struct nlattr *attr, int pos)
128{
129 struct nft_expr *expr;
130 int err;
131
132 expr = nft_set_elem_expr_alloc(ctx, set, attr);
133 if (IS_ERR(expr))
134 return expr;
135
136 if (set->exprs[pos] && set->exprs[pos]->ops != expr->ops) {
137 err = -EOPNOTSUPP;
138 goto err_dynset_expr;
139 }
140
141 return expr;
142
143err_dynset_expr:
144 nft_expr_destroy(ctx, expr);
145 return ERR_PTR(err);
146}
147
148static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
149 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
150 .len = NFT_SET_MAXNAMELEN - 1 },
151 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
152 [NFTA_DYNSET_OP] = NLA_POLICY_MAX(NLA_BE32, 255),
153 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
154 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
155 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
156 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
157 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
158 [NFTA_DYNSET_EXPRESSIONS] = { .type = NLA_NESTED },
159};
160
161static int nft_dynset_init(const struct nft_ctx *ctx,
162 const struct nft_expr *expr,
163 const struct nlattr * const tb[])
164{
165 struct nftables_pernet *nft_net = nft_pernet(ctx->net);
166 struct nft_dynset *priv = nft_expr_priv(expr);
167 u8 genmask = nft_genmask_next(ctx->net);
168 struct nft_set *set;
169 u64 timeout;
170 int err, i;
171
172 lockdep_assert_held(&nft_net->commit_mutex);
173
174 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
175 tb[NFTA_DYNSET_OP] == NULL ||
176 tb[NFTA_DYNSET_SREG_KEY] == NULL)
177 return -EINVAL;
178
179 if (tb[NFTA_DYNSET_FLAGS]) {
180 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
181 if (flags & ~(NFT_DYNSET_F_INV | NFT_DYNSET_F_EXPR))
182 return -EOPNOTSUPP;
183 if (flags & NFT_DYNSET_F_INV)
184 priv->invert = true;
185 if (flags & NFT_DYNSET_F_EXPR)
186 priv->expr = true;
187 }
188
189 set = nft_set_lookup_global(ctx->net, ctx->table,
190 tb[NFTA_DYNSET_SET_NAME],
191 tb[NFTA_DYNSET_SET_ID], genmask);
192 if (IS_ERR(set))
193 return PTR_ERR(set);
194
195 if (set->flags & NFT_SET_OBJECT)
196 return -EOPNOTSUPP;
197
198 if (set->ops->update == NULL)
199 return -EOPNOTSUPP;
200
201 if (set->flags & NFT_SET_CONSTANT)
202 return -EBUSY;
203
204 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
205 if (priv->op > NFT_DYNSET_OP_DELETE)
206 return -EOPNOTSUPP;
207
208 timeout = 0;
209 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
210 if (!(set->flags & NFT_SET_TIMEOUT))
211 return -EOPNOTSUPP;
212
213 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
214 if (err)
215 return err;
216 }
217
218 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
219 set->klen);
220 if (err < 0)
221 return err;
222
223 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
224 if (!(set->flags & NFT_SET_MAP))
225 return -EOPNOTSUPP;
226 if (set->dtype == NFT_DATA_VERDICT)
227 return -EOPNOTSUPP;
228
229 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA],
230 &priv->sreg_data, set->dlen);
231 if (err < 0)
232 return err;
233 } else if (set->flags & NFT_SET_MAP)
234 return -EINVAL;
235
236 if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) &&
237 !(set->flags & NFT_SET_EVAL))
238 return -EINVAL;
239
240 if (tb[NFTA_DYNSET_EXPR]) {
241 struct nft_expr *dynset_expr;
242
243 dynset_expr = nft_dynset_expr_alloc(ctx, set,
244 tb[NFTA_DYNSET_EXPR], 0);
245 if (IS_ERR(dynset_expr))
246 return PTR_ERR(dynset_expr);
247
248 priv->num_exprs++;
249 priv->expr_array[0] = dynset_expr;
250
251 if (set->num_exprs > 1 ||
252 (set->num_exprs == 1 &&
253 dynset_expr->ops != set->exprs[0]->ops)) {
254 err = -EOPNOTSUPP;
255 goto err_expr_free;
256 }
257 } else if (tb[NFTA_DYNSET_EXPRESSIONS]) {
258 struct nft_expr *dynset_expr;
259 struct nlattr *tmp;
260 int left;
261
262 if (!priv->expr)
263 return -EINVAL;
264
265 i = 0;
266 nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) {
267 if (i == NFT_SET_EXPR_MAX) {
268 err = -E2BIG;
269 goto err_expr_free;
270 }
271 if (nla_type(tmp) != NFTA_LIST_ELEM) {
272 err = -EINVAL;
273 goto err_expr_free;
274 }
275 dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i);
276 if (IS_ERR(dynset_expr)) {
277 err = PTR_ERR(dynset_expr);
278 goto err_expr_free;
279 }
280 priv->expr_array[i] = dynset_expr;
281 priv->num_exprs++;
282
283 if (set->num_exprs) {
284 if (i >= set->num_exprs) {
285 err = -EINVAL;
286 goto err_expr_free;
287 }
288 if (dynset_expr->ops != set->exprs[i]->ops) {
289 err = -EOPNOTSUPP;
290 goto err_expr_free;
291 }
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 nf_tables_activate_set(ctx, priv->set);
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,
370 const struct nft_expr *expr, bool reset)
371{
372 const struct nft_dynset *priv = nft_expr_priv(expr);
373 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
374 int i;
375
376 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
377 goto nla_put_failure;
378 if (priv->set->flags & NFT_SET_MAP &&
379 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
380 goto nla_put_failure;
381 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
382 goto nla_put_failure;
383 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
384 goto nla_put_failure;
385 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
386 nf_jiffies64_to_msecs(priv->timeout),
387 NFTA_DYNSET_PAD))
388 goto nla_put_failure;
389 if (priv->set->num_exprs == 0) {
390 if (priv->num_exprs == 1) {
391 if (nft_expr_dump(skb, NFTA_DYNSET_EXPR,
392 priv->expr_array[0], reset))
393 goto nla_put_failure;
394 } else if (priv->num_exprs > 1) {
395 struct nlattr *nest;
396
397 nest = nla_nest_start_noflag(skb, NFTA_DYNSET_EXPRESSIONS);
398 if (!nest)
399 goto nla_put_failure;
400
401 for (i = 0; i < priv->num_exprs; i++) {
402 if (nft_expr_dump(skb, NFTA_LIST_ELEM,
403 priv->expr_array[i], reset))
404 goto nla_put_failure;
405 }
406 nla_nest_end(skb, nest);
407 }
408 }
409 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
410 goto nla_put_failure;
411 return 0;
412
413nla_put_failure:
414 return -1;
415}
416
417static const struct nft_expr_ops nft_dynset_ops = {
418 .type = &nft_dynset_type,
419 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
420 .eval = nft_dynset_eval,
421 .init = nft_dynset_init,
422 .destroy = nft_dynset_destroy,
423 .activate = nft_dynset_activate,
424 .deactivate = nft_dynset_deactivate,
425 .dump = nft_dynset_dump,
426 .reduce = NFT_REDUCE_READONLY,
427};
428
429struct nft_expr_type nft_dynset_type __read_mostly = {
430 .name = "dynset",
431 .ops = &nft_dynset_ops,
432 .policy = nft_dynset_policy,
433 .maxattr = NFTA_DYNSET_MAX,
434 .owner = THIS_MODULE,
435};