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]) < 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 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 (IS_ERR(elem))
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
72 err2:
73 nft_set_elem_destroy(set, elem, false);
74 err1:
75 if (set->size)
76 atomic_dec(&set->nelems);
77 return NULL;
78 }
79
nft_dynset_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)80 void 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
nft_dynset_ext_add_expr(struct nft_dynset * priv)112 static 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
124 static struct nft_expr *
nft_dynset_expr_alloc(const struct nft_ctx * ctx,const struct nft_set * set,const struct nlattr * attr,int pos)125 nft_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
142 err_dynset_expr:
143 nft_expr_destroy(ctx, expr);
144 return ERR_PTR(err);
145 }
146
147 static 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] = NLA_POLICY_MAX(NLA_BE32, 255),
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
nft_dynset_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])160 static 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->flags & NFT_SET_OBJECT)
195 return -EOPNOTSUPP;
196
197 if (set->ops->update == NULL)
198 return -EOPNOTSUPP;
199
200 if (set->flags & NFT_SET_CONSTANT)
201 return -EBUSY;
202
203 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
204 if (priv->op > NFT_DYNSET_OP_DELETE)
205 return -EOPNOTSUPP;
206
207 timeout = 0;
208 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
209 if (!(set->flags & NFT_SET_TIMEOUT))
210 return -EOPNOTSUPP;
211
212 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
213 if (err)
214 return err;
215 }
216
217 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
218 set->klen);
219 if (err < 0)
220 return err;
221
222 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
223 if (!(set->flags & NFT_SET_MAP))
224 return -EOPNOTSUPP;
225 if (set->dtype == NFT_DATA_VERDICT)
226 return -EOPNOTSUPP;
227
228 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA],
229 &priv->sreg_data, set->dlen);
230 if (err < 0)
231 return err;
232 } else if (set->flags & NFT_SET_MAP)
233 return -EINVAL;
234
235 if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) &&
236 !(set->flags & NFT_SET_EVAL))
237 return -EINVAL;
238
239 if (tb[NFTA_DYNSET_EXPR]) {
240 struct nft_expr *dynset_expr;
241
242 dynset_expr = nft_dynset_expr_alloc(ctx, set,
243 tb[NFTA_DYNSET_EXPR], 0);
244 if (IS_ERR(dynset_expr))
245 return PTR_ERR(dynset_expr);
246
247 priv->num_exprs++;
248 priv->expr_array[0] = dynset_expr;
249
250 if (set->num_exprs > 1 ||
251 (set->num_exprs == 1 &&
252 dynset_expr->ops != set->exprs[0]->ops)) {
253 err = -EOPNOTSUPP;
254 goto err_expr_free;
255 }
256 } else if (tb[NFTA_DYNSET_EXPRESSIONS]) {
257 struct nft_expr *dynset_expr;
258 struct nlattr *tmp;
259 int left;
260
261 if (!priv->expr)
262 return -EINVAL;
263
264 i = 0;
265 nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) {
266 if (i == NFT_SET_EXPR_MAX) {
267 err = -E2BIG;
268 goto err_expr_free;
269 }
270 if (nla_type(tmp) != NFTA_LIST_ELEM) {
271 err = -EINVAL;
272 goto err_expr_free;
273 }
274 dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i);
275 if (IS_ERR(dynset_expr)) {
276 err = PTR_ERR(dynset_expr);
277 goto err_expr_free;
278 }
279 priv->expr_array[i] = dynset_expr;
280 priv->num_exprs++;
281
282 if (set->num_exprs) {
283 if (i >= set->num_exprs) {
284 err = -EINVAL;
285 goto err_expr_free;
286 }
287 if (dynset_expr->ops != set->exprs[i]->ops) {
288 err = -EOPNOTSUPP;
289 goto err_expr_free;
290 }
291 }
292 i++;
293 }
294 if (set->num_exprs && set->num_exprs != i) {
295 err = -EOPNOTSUPP;
296 goto err_expr_free;
297 }
298 } else if (set->num_exprs > 0) {
299 err = nft_set_elem_expr_clone(ctx, set, priv->expr_array);
300 if (err < 0)
301 return err;
302
303 priv->num_exprs = set->num_exprs;
304 }
305
306 nft_set_ext_prepare(&priv->tmpl);
307 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
308 if (set->flags & NFT_SET_MAP)
309 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
310
311 if (priv->num_exprs)
312 nft_dynset_ext_add_expr(priv);
313
314 if (set->flags & NFT_SET_TIMEOUT) {
315 if (timeout || set->timeout) {
316 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
317 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
318 }
319 }
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