netfilter: nf_tables: add nft_set_elem_update_expr() helper function
[linux-block.git] / net / netfilter / nft_dynset.c
CommitLineData
d2912cb1 1// SPDX-License-Identifier: GPL-2.0-only
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2/*
3 * Copyright (c) 2015 Patrick McHardy <kaber@trash.net>
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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 enum nft_registers sreg_key:8;
20 enum nft_registers sreg_data:8;
dbd2be06 21 bool invert;
22fe54d5 22 u64 timeout;
3e135cd4 23 struct nft_expr *expr;
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24 struct nft_set_binding binding;
25};
26
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27static int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
28{
29 int err;
30
31 if (src->ops->clone) {
32 dst->ops = src->ops;
33 err = src->ops->clone(dst, src);
34 if (err < 0)
35 return err;
36 } else {
37 memcpy(dst, src, src->ops->size);
38 }
39
40 __module_get(src->ops->type->owner);
41 return 0;
42}
43
22fe54d5 44static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
a55e22e9 45 struct nft_regs *regs)
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46{
47 const struct nft_dynset *priv = nft_expr_priv(expr);
3e135cd4 48 struct nft_set_ext *ext;
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49 u64 timeout;
50 void *elem;
51
99a0efbe 52 if (!atomic_add_unless(&set->nelems, 1, set->size))
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53 return NULL;
54
55 timeout = priv->timeout ? : set->timeout;
56 elem = nft_set_elem_init(set, &priv->tmpl,
7b225d0b 57 &regs->data[priv->sreg_key], NULL,
a55e22e9 58 &regs->data[priv->sreg_data],
79ebb5bb 59 timeout, 0, GFP_ATOMIC);
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60 if (elem == NULL)
61 goto err1;
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62
63 ext = nft_set_elem_ext(set, elem);
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64 if (priv->expr != NULL &&
65 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
61f9e292 66 goto err2;
3e135cd4 67
22fe54d5 68 return elem;
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69
70err2:
71 nft_set_elem_destroy(set, elem, false);
72err1:
73 if (set->size)
74 atomic_dec(&set->nelems);
75 return NULL;
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76}
77
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78void nft_dynset_eval(const struct nft_expr *expr,
79 struct nft_regs *regs, const struct nft_pktinfo *pkt)
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80{
81 const struct nft_dynset *priv = nft_expr_priv(expr);
82 struct nft_set *set = priv->set;
83 const struct nft_set_ext *ext;
84 u64 timeout;
85
d0a8d877
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86 if (priv->op == NFT_DYNSET_OP_DELETE) {
87 set->ops->delete(set, &regs->data[priv->sreg_key]);
88 return;
89 }
90
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91 if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
92 expr, regs, &ext)) {
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93 if (priv->op == NFT_DYNSET_OP_UPDATE &&
94 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
95 timeout = priv->timeout ? : set->timeout;
b13468dc 96 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
277a2928 97 }
22fe54d5 98
76adfafe 99 nft_set_elem_update_expr(ext, regs, pkt);
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100
101 if (priv->invert)
102 regs->verdict.code = NFT_BREAK;
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103 return;
104 }
277a2928 105
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106 if (!priv->invert)
107 regs->verdict.code = NFT_BREAK;
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108}
109
110static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
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111 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
112 .len = NFT_SET_MAXNAMELEN - 1 },
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113 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
114 [NFTA_DYNSET_OP] = { .type = NLA_U32 },
115 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
116 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
117 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
3e135cd4 118 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
dbd2be06 119 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
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120};
121
122static int nft_dynset_init(const struct nft_ctx *ctx,
123 const struct nft_expr *expr,
124 const struct nlattr * const tb[])
125{
126 struct nft_dynset *priv = nft_expr_priv(expr);
37a9cc52 127 u8 genmask = nft_genmask_next(ctx->net);
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128 struct nft_set *set;
129 u64 timeout;
130 int err;
131
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132 lockdep_assert_held(&ctx->net->nft.commit_mutex);
133
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134 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
135 tb[NFTA_DYNSET_OP] == NULL ||
136 tb[NFTA_DYNSET_SREG_KEY] == NULL)
137 return -EINVAL;
138
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139 if (tb[NFTA_DYNSET_FLAGS]) {
140 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
141
142 if (flags & ~NFT_DYNSET_F_INV)
143 return -EINVAL;
144 if (flags & NFT_DYNSET_F_INV)
145 priv->invert = true;
146 }
147
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148 set = nft_set_lookup_global(ctx->net, ctx->table,
149 tb[NFTA_DYNSET_SET_NAME],
150 tb[NFTA_DYNSET_SET_ID], genmask);
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151 if (IS_ERR(set))
152 return PTR_ERR(set);
22fe54d5 153
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154 if (set->ops->update == NULL)
155 return -EOPNOTSUPP;
156
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157 if (set->flags & NFT_SET_CONSTANT)
158 return -EBUSY;
159
160 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
161 switch (priv->op) {
162 case NFT_DYNSET_OP_ADD:
d0a8d877 163 case NFT_DYNSET_OP_DELETE:
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164 break;
165 case NFT_DYNSET_OP_UPDATE:
166 if (!(set->flags & NFT_SET_TIMEOUT))
167 return -EOPNOTSUPP;
168 break;
169 default:
170 return -EOPNOTSUPP;
171 }
172
173 timeout = 0;
174 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
175 if (!(set->flags & NFT_SET_TIMEOUT))
176 return -EINVAL;
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177 timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64(
178 tb[NFTA_DYNSET_TIMEOUT])));
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179 }
180
b1c96ed3 181 priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
b0c3dc65 182 err = nft_validate_register_load(priv->sreg_key, set->klen);
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183 if (err < 0)
184 return err;
185
186 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
187 if (!(set->flags & NFT_SET_MAP))
188 return -EINVAL;
189 if (set->dtype == NFT_DATA_VERDICT)
190 return -EOPNOTSUPP;
191
b1c96ed3 192 priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
d07db988 193 err = nft_validate_register_load(priv->sreg_data, set->dlen);
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194 if (err < 0)
195 return err;
196 } else if (set->flags & NFT_SET_MAP)
197 return -EINVAL;
198
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199 if (tb[NFTA_DYNSET_EXPR] != NULL) {
200 if (!(set->flags & NFT_SET_EVAL))
201 return -EINVAL;
3e135cd4 202
a7fc9368
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203 priv->expr = nft_set_elem_expr_alloc(ctx, set,
204 tb[NFTA_DYNSET_EXPR]);
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205 if (IS_ERR(priv->expr))
206 return PTR_ERR(priv->expr);
215a31f1 207 }
3e135cd4 208
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209 nft_set_ext_prepare(&priv->tmpl);
210 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
211 if (set->flags & NFT_SET_MAP)
212 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
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213 if (priv->expr != NULL)
214 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
215 priv->expr->ops->size);
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216 if (set->flags & NFT_SET_TIMEOUT) {
217 if (timeout || set->timeout)
218 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
219 }
220
221 priv->timeout = timeout;
222
223 err = nf_tables_bind_set(ctx, set, &priv->binding);
224 if (err < 0)
3e135cd4 225 goto err1;
22fe54d5 226
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227 if (set->size == 0)
228 set->size = 0xffff;
229
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230 priv->set = set;
231 return 0;
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232
233err1:
234 if (priv->expr != NULL)
235 nft_expr_destroy(ctx, priv->expr);
236 return err;
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237}
238
cd5125d8 239static void nft_dynset_deactivate(const struct nft_ctx *ctx,
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240 const struct nft_expr *expr,
241 enum nft_trans_phase phase)
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242{
243 struct nft_dynset *priv = nft_expr_priv(expr);
244
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245 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
246}
247
248static void nft_dynset_activate(const struct nft_ctx *ctx,
249 const struct nft_expr *expr)
250{
251 struct nft_dynset *priv = nft_expr_priv(expr);
f6ac8585 252
273fe3f1 253 priv->set->use++;
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254}
255
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256static void nft_dynset_destroy(const struct nft_ctx *ctx,
257 const struct nft_expr *expr)
258{
259 struct nft_dynset *priv = nft_expr_priv(expr);
260
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261 if (priv->expr != NULL)
262 nft_expr_destroy(ctx, priv->expr);
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263
264 nf_tables_destroy_set(ctx, priv->set);
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265}
266
267static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
268{
269 const struct nft_dynset *priv = nft_expr_priv(expr);
dbd2be06 270 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
22fe54d5 271
b1c96ed3 272 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
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273 goto nla_put_failure;
274 if (priv->set->flags & NFT_SET_MAP &&
b1c96ed3 275 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
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276 goto nla_put_failure;
277 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
278 goto nla_put_failure;
279 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
280 goto nla_put_failure;
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281 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
282 cpu_to_be64(jiffies_to_msecs(priv->timeout)),
b46f6ded 283 NFTA_DYNSET_PAD))
22fe54d5 284 goto nla_put_failure;
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285 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
286 goto nla_put_failure;
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287 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
288 goto nla_put_failure;
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289 return 0;
290
291nla_put_failure:
292 return -1;
293}
294
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295static const struct nft_expr_ops nft_dynset_ops = {
296 .type = &nft_dynset_type,
297 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
298 .eval = nft_dynset_eval,
299 .init = nft_dynset_init,
300 .destroy = nft_dynset_destroy,
273fe3f1 301 .activate = nft_dynset_activate,
cd5125d8 302 .deactivate = nft_dynset_deactivate,
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303 .dump = nft_dynset_dump,
304};
305
4e24877e 306struct nft_expr_type nft_dynset_type __read_mostly = {
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307 .name = "dynset",
308 .ops = &nft_dynset_ops,
309 .policy = nft_dynset_policy,
310 .maxattr = NFTA_DYNSET_MAX,
311 .owner = THIS_MODULE,
312};