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 #include <net/netns/generic.h>
15
16 extern unsigned int nf_tables_net_id;
17
18 struct nft_dynset {
19 struct nft_set *set;
20 struct nft_set_ext_tmpl tmpl;
21 enum nft_dynset_ops op:8;
22 u8 sreg_key;
23 u8 sreg_data;
24 bool invert;
25 u64 timeout;
26 struct nft_expr *expr;
27 struct nft_set_binding binding;
28 };
29
nft_expr_clone(struct nft_expr * dst,struct nft_expr * src)30 static int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
31 {
32 int err;
33
34 if (src->ops->clone) {
35 dst->ops = src->ops;
36 err = src->ops->clone(dst, src);
37 if (err < 0)
38 return err;
39 } else {
40 memcpy(dst, src, src->ops->size);
41 }
42
43 __module_get(src->ops->type->owner);
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],
61 ®s->data[priv->sreg_data],
62 timeout, 0, GFP_ATOMIC);
63 if (elem == NULL)
64 goto err1;
65
66 ext = nft_set_elem_ext(set, elem);
67 if (priv->expr != NULL &&
68 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
69 goto err2;
70
71 return elem;
72
73 err2:
74 nft_set_elem_destroy(set, elem, 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 const struct nft_expr *sexpr;
88 u64 timeout;
89
90 if (priv->op == NFT_DYNSET_OP_DELETE) {
91 set->ops->delete(set, ®s->data[priv->sreg_key]);
92 return;
93 }
94
95 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
96 expr, regs, &ext)) {
97 sexpr = NULL;
98 if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
99 sexpr = nft_set_ext_expr(ext);
100
101 if (priv->op == NFT_DYNSET_OP_UPDATE &&
102 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
103 timeout = priv->timeout ? : set->timeout;
104 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
105 }
106
107 if (sexpr != NULL)
108 sexpr->ops->eval(sexpr, regs, pkt);
109
110 if (priv->invert)
111 regs->verdict.code = NFT_BREAK;
112 return;
113 }
114
115 if (!priv->invert)
116 regs->verdict.code = NFT_BREAK;
117 }
118
119 static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
120 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
121 .len = NFT_SET_MAXNAMELEN - 1 },
122 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
123 [NFTA_DYNSET_OP] = { .type = NLA_U32 },
124 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
125 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
126 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
127 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
128 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
129 };
130
nft_dynset_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])131 static int nft_dynset_init(const struct nft_ctx *ctx,
132 const struct nft_expr *expr,
133 const struct nlattr * const tb[])
134 {
135 struct nftables_pernet *nft_net = net_generic(ctx->net, nf_tables_net_id);
136 struct nft_dynset *priv = nft_expr_priv(expr);
137 u8 genmask = nft_genmask_next(ctx->net);
138 struct nft_set *set;
139 u64 timeout;
140 int err;
141
142 lockdep_assert_held(&nft_net->commit_mutex);
143
144 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
145 tb[NFTA_DYNSET_OP] == NULL ||
146 tb[NFTA_DYNSET_SREG_KEY] == NULL)
147 return -EINVAL;
148
149 if (tb[NFTA_DYNSET_FLAGS]) {
150 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
151
152 if (flags & ~NFT_DYNSET_F_INV)
153 return -EOPNOTSUPP;
154 if (flags & NFT_DYNSET_F_INV)
155 priv->invert = true;
156 }
157
158 set = nft_set_lookup_global(ctx->net, ctx->table,
159 tb[NFTA_DYNSET_SET_NAME],
160 tb[NFTA_DYNSET_SET_ID], genmask);
161 if (IS_ERR(set))
162 return PTR_ERR(set);
163
164 if (set->flags & NFT_SET_OBJECT)
165 return -EOPNOTSUPP;
166
167 if (set->ops->update == NULL)
168 return -EOPNOTSUPP;
169
170 if (set->flags & NFT_SET_CONSTANT)
171 return -EBUSY;
172
173 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
174 if (priv->op > NFT_DYNSET_OP_DELETE)
175 return -EOPNOTSUPP;
176
177 timeout = 0;
178 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
179 if (!(set->flags & NFT_SET_TIMEOUT))
180 return -EOPNOTSUPP;
181
182 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
183 if (err)
184 return err;
185 }
186
187 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
188 set->klen);
189 if (err < 0)
190 return err;
191
192 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
193 if (!(set->flags & NFT_SET_MAP))
194 return -EOPNOTSUPP;
195 if (set->dtype == NFT_DATA_VERDICT)
196 return -EOPNOTSUPP;
197
198 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA],
199 &priv->sreg_data, set->dlen);
200 if (err < 0)
201 return err;
202 } else if (set->flags & NFT_SET_MAP)
203 return -EINVAL;
204
205 if (tb[NFTA_DYNSET_EXPR] != NULL) {
206 if (!(set->flags & NFT_SET_EVAL))
207 return -EINVAL;
208
209 priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
210 if (IS_ERR(priv->expr))
211 return PTR_ERR(priv->expr);
212
213 err = -EOPNOTSUPP;
214 if (priv->expr->ops->type->flags & NFT_EXPR_GC) {
215 if (set->flags & NFT_SET_TIMEOUT)
216 goto err1;
217 if (!set->ops->gc_init)
218 goto err1;
219 set->ops->gc_init(set);
220 }
221 }
222
223 nft_set_ext_prepare(&priv->tmpl);
224 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
225 if (set->flags & NFT_SET_MAP)
226 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
227 if (priv->expr != NULL)
228 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
229 priv->expr->ops->size);
230 if (set->flags & NFT_SET_TIMEOUT) {
231 if (timeout || set->timeout) {
232 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
233 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
234 }
235 }
236
237 priv->timeout = timeout;
238
239 err = nf_tables_bind_set(ctx, set, &priv->binding);
240 if (err < 0)
241 goto err1;
242
243 if (set->size == 0)
244 set->size = 0xffff;
245
246 priv->set = set;
247 return 0;
248
249 err1:
250 if (priv->expr != NULL)
251 nft_expr_destroy(ctx, priv->expr);
252 return err;
253 }
254
nft_dynset_deactivate(const struct nft_ctx * ctx,const struct nft_expr * expr,enum nft_trans_phase phase)255 static void nft_dynset_deactivate(const struct nft_ctx *ctx,
256 const struct nft_expr *expr,
257 enum nft_trans_phase phase)
258 {
259 struct nft_dynset *priv = nft_expr_priv(expr);
260
261 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
262 }
263
nft_dynset_activate(const struct nft_ctx * ctx,const struct nft_expr * expr)264 static void nft_dynset_activate(const struct nft_ctx *ctx,
265 const struct nft_expr *expr)
266 {
267 struct nft_dynset *priv = nft_expr_priv(expr);
268
269 nf_tables_activate_set(ctx, priv->set);
270 }
271
nft_dynset_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)272 static void nft_dynset_destroy(const struct nft_ctx *ctx,
273 const struct nft_expr *expr)
274 {
275 struct nft_dynset *priv = nft_expr_priv(expr);
276
277 if (priv->expr != NULL)
278 nft_expr_destroy(ctx, priv->expr);
279
280 nf_tables_destroy_set(ctx, priv->set);
281 }
282
nft_dynset_dump(struct sk_buff * skb,const struct nft_expr * expr)283 static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
284 {
285 const struct nft_dynset *priv = nft_expr_priv(expr);
286 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
287
288 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
289 goto nla_put_failure;
290 if (priv->set->flags & NFT_SET_MAP &&
291 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
292 goto nla_put_failure;
293 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
294 goto nla_put_failure;
295 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
296 goto nla_put_failure;
297 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
298 nf_jiffies64_to_msecs(priv->timeout),
299 NFTA_DYNSET_PAD))
300 goto nla_put_failure;
301 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
302 goto nla_put_failure;
303 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
304 goto nla_put_failure;
305 return 0;
306
307 nla_put_failure:
308 return -1;
309 }
310
311 static const struct nft_expr_ops nft_dynset_ops = {
312 .type = &nft_dynset_type,
313 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
314 .eval = nft_dynset_eval,
315 .init = nft_dynset_init,
316 .destroy = nft_dynset_destroy,
317 .activate = nft_dynset_activate,
318 .deactivate = nft_dynset_deactivate,
319 .dump = nft_dynset_dump,
320 };
321
322 struct nft_expr_type nft_dynset_type __read_mostly = {
323 .name = "dynset",
324 .ops = &nft_dynset_ops,
325 .policy = nft_dynset_policy,
326 .maxattr = NFTA_DYNSET_MAX,
327 .owner = THIS_MODULE,
328 };
329