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 u64 timeout;
23 struct nft_expr *expr;
24 struct nft_set_binding binding;
25 };
26
nft_dynset_new(struct nft_set * set,const struct nft_expr * expr,struct nft_regs * regs)27 static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
28 struct nft_regs *regs)
29 {
30 const struct nft_dynset *priv = nft_expr_priv(expr);
31 struct nft_set_ext *ext;
32 u64 timeout;
33 void *elem;
34
35 if (!atomic_add_unless(&set->nelems, 1, set->size))
36 return NULL;
37
38 timeout = priv->timeout ? : set->timeout;
39 elem = nft_set_elem_init(set, &priv->tmpl,
40 ®s->data[priv->sreg_key], NULL,
41 ®s->data[priv->sreg_data],
42 timeout, 0, GFP_ATOMIC);
43 if (elem == NULL)
44 goto err1;
45
46 ext = nft_set_elem_ext(set, elem);
47 if (priv->expr != NULL &&
48 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
49 goto err2;
50
51 return elem;
52
53 err2:
54 nft_set_elem_destroy(set, elem, false);
55 err1:
56 if (set->size)
57 atomic_dec(&set->nelems);
58 return NULL;
59 }
60
nft_dynset_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)61 void nft_dynset_eval(const struct nft_expr *expr,
62 struct nft_regs *regs, const struct nft_pktinfo *pkt)
63 {
64 const struct nft_dynset *priv = nft_expr_priv(expr);
65 struct nft_set *set = priv->set;
66 const struct nft_set_ext *ext;
67 u64 timeout;
68
69 if (priv->op == NFT_DYNSET_OP_DELETE) {
70 set->ops->delete(set, ®s->data[priv->sreg_key]);
71 return;
72 }
73
74 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
75 expr, regs, &ext)) {
76 if (priv->op == NFT_DYNSET_OP_UPDATE &&
77 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
78 timeout = priv->timeout ? : set->timeout;
79 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
80 }
81
82 nft_set_elem_update_expr(ext, regs, pkt);
83
84 if (priv->invert)
85 regs->verdict.code = NFT_BREAK;
86 return;
87 }
88
89 if (!priv->invert)
90 regs->verdict.code = NFT_BREAK;
91 }
92
93 static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
94 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
95 .len = NFT_SET_MAXNAMELEN - 1 },
96 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
97 [NFTA_DYNSET_OP] = { .type = NLA_U32 },
98 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
99 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
100 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
101 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
102 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
103 };
104
nft_dynset_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])105 static int nft_dynset_init(const struct nft_ctx *ctx,
106 const struct nft_expr *expr,
107 const struct nlattr * const tb[])
108 {
109 struct nft_dynset *priv = nft_expr_priv(expr);
110 u8 genmask = nft_genmask_next(ctx->net);
111 struct nft_set *set;
112 u64 timeout;
113 int err;
114
115 lockdep_assert_held(&ctx->net->nft.commit_mutex);
116
117 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
118 tb[NFTA_DYNSET_OP] == NULL ||
119 tb[NFTA_DYNSET_SREG_KEY] == NULL)
120 return -EINVAL;
121
122 if (tb[NFTA_DYNSET_FLAGS]) {
123 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
124
125 if (flags & ~NFT_DYNSET_F_INV)
126 return -EOPNOTSUPP;
127 if (flags & NFT_DYNSET_F_INV)
128 priv->invert = true;
129 }
130
131 set = nft_set_lookup_global(ctx->net, ctx->table,
132 tb[NFTA_DYNSET_SET_NAME],
133 tb[NFTA_DYNSET_SET_ID], genmask);
134 if (IS_ERR(set))
135 return PTR_ERR(set);
136
137 if (set->ops->update == NULL)
138 return -EOPNOTSUPP;
139
140 if (set->flags & NFT_SET_CONSTANT)
141 return -EBUSY;
142
143 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
144 if (priv->op > NFT_DYNSET_OP_DELETE)
145 return -EOPNOTSUPP;
146
147 timeout = 0;
148 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
149 if (!(set->flags & NFT_SET_TIMEOUT))
150 return -EOPNOTSUPP;
151
152 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout);
153 if (err)
154 return err;
155 }
156
157 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key,
158 set->klen);
159 if (err < 0)
160 return err;
161
162 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
163 if (!(set->flags & NFT_SET_MAP))
164 return -EOPNOTSUPP;
165 if (set->dtype == NFT_DATA_VERDICT)
166 return -EOPNOTSUPP;
167
168 err = nft_parse_register_load(tb[NFTA_DYNSET_SREG_DATA],
169 &priv->sreg_data, set->dlen);
170 if (err < 0)
171 return err;
172 } else if (set->flags & NFT_SET_MAP)
173 return -EINVAL;
174
175 if (tb[NFTA_DYNSET_EXPR] != NULL) {
176 if (!(set->flags & NFT_SET_EVAL))
177 return -EINVAL;
178
179 priv->expr = nft_set_elem_expr_alloc(ctx, set,
180 tb[NFTA_DYNSET_EXPR]);
181 if (IS_ERR(priv->expr))
182 return PTR_ERR(priv->expr);
183
184 if (set->expr && set->expr->ops != priv->expr->ops) {
185 err = -EOPNOTSUPP;
186 goto err_expr_free;
187 }
188 }
189
190 nft_set_ext_prepare(&priv->tmpl);
191 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
192 if (set->flags & NFT_SET_MAP)
193 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
194 if (priv->expr != NULL)
195 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
196 priv->expr->ops->size);
197 if (set->flags & NFT_SET_TIMEOUT) {
198 if (timeout || set->timeout) {
199 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT);
200 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
201 }
202 }
203
204 priv->timeout = timeout;
205
206 err = nf_tables_bind_set(ctx, set, &priv->binding);
207 if (err < 0)
208 goto err_expr_free;
209
210 if (set->size == 0)
211 set->size = 0xffff;
212
213 priv->set = set;
214 return 0;
215
216 err_expr_free:
217 if (priv->expr != NULL)
218 nft_expr_destroy(ctx, priv->expr);
219 return err;
220 }
221
nft_dynset_deactivate(const struct nft_ctx * ctx,const struct nft_expr * expr,enum nft_trans_phase phase)222 static void nft_dynset_deactivate(const struct nft_ctx *ctx,
223 const struct nft_expr *expr,
224 enum nft_trans_phase phase)
225 {
226 struct nft_dynset *priv = nft_expr_priv(expr);
227
228 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
229 }
230
nft_dynset_activate(const struct nft_ctx * ctx,const struct nft_expr * expr)231 static void nft_dynset_activate(const struct nft_ctx *ctx,
232 const struct nft_expr *expr)
233 {
234 struct nft_dynset *priv = nft_expr_priv(expr);
235
236 priv->set->use++;
237 }
238
nft_dynset_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)239 static void nft_dynset_destroy(const struct nft_ctx *ctx,
240 const struct nft_expr *expr)
241 {
242 struct nft_dynset *priv = nft_expr_priv(expr);
243
244 if (priv->expr != NULL)
245 nft_expr_destroy(ctx, priv->expr);
246
247 nf_tables_destroy_set(ctx, priv->set);
248 }
249
nft_dynset_dump(struct sk_buff * skb,const struct nft_expr * expr)250 static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
251 {
252 const struct nft_dynset *priv = nft_expr_priv(expr);
253 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
254
255 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
256 goto nla_put_failure;
257 if (priv->set->flags & NFT_SET_MAP &&
258 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
259 goto nla_put_failure;
260 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
261 goto nla_put_failure;
262 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
263 goto nla_put_failure;
264 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
265 nf_jiffies64_to_msecs(priv->timeout),
266 NFTA_DYNSET_PAD))
267 goto nla_put_failure;
268 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
269 goto nla_put_failure;
270 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
271 goto nla_put_failure;
272 return 0;
273
274 nla_put_failure:
275 return -1;
276 }
277
278 static const struct nft_expr_ops nft_dynset_ops = {
279 .type = &nft_dynset_type,
280 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
281 .eval = nft_dynset_eval,
282 .init = nft_dynset_init,
283 .destroy = nft_dynset_destroy,
284 .activate = nft_dynset_activate,
285 .deactivate = nft_dynset_deactivate,
286 .dump = nft_dynset_dump,
287 };
288
289 struct nft_expr_type nft_dynset_type __read_mostly = {
290 .name = "dynset",
291 .ops = &nft_dynset_ops,
292 .policy = nft_dynset_policy,
293 .maxattr = NFTA_DYNSET_MAX,
294 .owner = THIS_MODULE,
295 };
296