tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (c) 2015 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/netlink.h>
14#include <linux/netfilter.h>
15#include <linux/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables.h>
17#include <net/netfilter/nf_tables_core.h>
18
19struct nft_dynset {
20 struct nft_set *set;
21 struct nft_set_ext_tmpl tmpl;
22 enum nft_dynset_ops op:8;
23 enum nft_registers sreg_key:8;
24 enum nft_registers sreg_data:8;
25 bool invert;
26 u64 timeout;
27 struct nft_expr *expr;
28 struct nft_set_binding binding;
29};
30
31static int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
32{
33 int err;
34
35 if (src->ops->clone) {
36 dst->ops = src->ops;
37 err = src->ops->clone(dst, src);
38 if (err < 0)
39 return err;
40 } else {
41 memcpy(dst, src, src->ops->size);
42 }
43
44 __module_get(src->ops->type->owner);
45 return 0;
46}
47
48static void *nft_dynset_new(struct nft_set *set, 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 u64 timeout;
54 void *elem;
55
56 if (!atomic_add_unless(&set->nelems, 1, set->size))
57 return NULL;
58
59 timeout = priv->timeout ? : set->timeout;
60 elem = nft_set_elem_init(set, &priv->tmpl,
61 ®s->data[priv->sreg_key],
62 ®s->data[priv->sreg_data],
63 timeout, GFP_ATOMIC);
64 if (elem == NULL)
65 goto err1;
66
67 ext = nft_set_elem_ext(set, elem);
68 if (priv->expr != NULL &&
69 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
70 goto err2;
71
72 return elem;
73
74err2:
75 nft_set_elem_destroy(set, elem, false);
76err1:
77 if (set->size)
78 atomic_dec(&set->nelems);
79 return NULL;
80}
81
82void nft_dynset_eval(const struct nft_expr *expr,
83 struct nft_regs *regs, const struct nft_pktinfo *pkt)
84{
85 const struct nft_dynset *priv = nft_expr_priv(expr);
86 struct nft_set *set = priv->set;
87 const struct nft_set_ext *ext;
88 const struct nft_expr *sexpr;
89 u64 timeout;
90
91 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
92 expr, regs, &ext)) {
93 sexpr = NULL;
94 if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
95 sexpr = nft_set_ext_expr(ext);
96
97 if (priv->op == NFT_DYNSET_OP_UPDATE &&
98 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
99 timeout = priv->timeout ? : set->timeout;
100 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout;
101 }
102
103 if (sexpr != NULL)
104 sexpr->ops->eval(sexpr, regs, pkt);
105
106 if (priv->invert)
107 regs->verdict.code = NFT_BREAK;
108 return;
109 }
110
111 if (!priv->invert)
112 regs->verdict.code = NFT_BREAK;
113}
114
115static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
116 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
117 .len = NFT_SET_MAXNAMELEN - 1 },
118 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
119 [NFTA_DYNSET_OP] = { .type = NLA_U32 },
120 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
121 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
122 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
123 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
124 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
125};
126
127static int nft_dynset_init(const struct nft_ctx *ctx,
128 const struct nft_expr *expr,
129 const struct nlattr * const tb[])
130{
131 struct nft_dynset *priv = nft_expr_priv(expr);
132 u8 genmask = nft_genmask_next(ctx->net);
133 struct nft_set *set;
134 u64 timeout;
135 int err;
136
137 lockdep_assert_held(&ctx->net->nft.commit_mutex);
138
139 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
140 tb[NFTA_DYNSET_OP] == NULL ||
141 tb[NFTA_DYNSET_SREG_KEY] == NULL)
142 return -EINVAL;
143
144 if (tb[NFTA_DYNSET_FLAGS]) {
145 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
146
147 if (flags & ~NFT_DYNSET_F_INV)
148 return -EINVAL;
149 if (flags & NFT_DYNSET_F_INV)
150 priv->invert = true;
151 }
152
153 set = nft_set_lookup_global(ctx->net, ctx->table,
154 tb[NFTA_DYNSET_SET_NAME],
155 tb[NFTA_DYNSET_SET_ID], genmask);
156 if (IS_ERR(set))
157 return PTR_ERR(set);
158
159 if (set->ops->update == NULL)
160 return -EOPNOTSUPP;
161
162 if (set->flags & NFT_SET_CONSTANT)
163 return -EBUSY;
164
165 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
166 switch (priv->op) {
167 case NFT_DYNSET_OP_ADD:
168 break;
169 case NFT_DYNSET_OP_UPDATE:
170 if (!(set->flags & NFT_SET_TIMEOUT))
171 return -EOPNOTSUPP;
172 break;
173 default:
174 return -EOPNOTSUPP;
175 }
176
177 timeout = 0;
178 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
179 if (!(set->flags & NFT_SET_TIMEOUT))
180 return -EINVAL;
181 timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64(
182 tb[NFTA_DYNSET_TIMEOUT])));
183 }
184
185 priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
186 err = nft_validate_register_load(priv->sreg_key, set->klen);
187 if (err < 0)
188 return err;
189
190 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
191 if (!(set->flags & NFT_SET_MAP))
192 return -EINVAL;
193 if (set->dtype == NFT_DATA_VERDICT)
194 return -EOPNOTSUPP;
195
196 priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
197 err = nft_validate_register_load(priv->sreg_data, set->dlen);
198 if (err < 0)
199 return err;
200 } else if (set->flags & NFT_SET_MAP)
201 return -EINVAL;
202
203 if (tb[NFTA_DYNSET_EXPR] != NULL) {
204 if (!(set->flags & NFT_SET_EVAL))
205 return -EINVAL;
206
207 priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
208 if (IS_ERR(priv->expr))
209 return PTR_ERR(priv->expr);
210
211 err = -EOPNOTSUPP;
212 if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
213 goto err1;
214
215 if (priv->expr->ops->type->flags & NFT_EXPR_GC) {
216 if (set->flags & NFT_SET_TIMEOUT)
217 goto err1;
218 if (!set->ops->gc_init)
219 goto err1;
220 set->ops->gc_init(set);
221 }
222 }
223
224 nft_set_ext_prepare(&priv->tmpl);
225 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
226 if (set->flags & NFT_SET_MAP)
227 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
228 if (priv->expr != NULL)
229 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
230 priv->expr->ops->size);
231 if (set->flags & NFT_SET_TIMEOUT) {
232 if (timeout || set->timeout)
233 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
234 }
235
236 priv->timeout = timeout;
237
238 err = nf_tables_bind_set(ctx, set, &priv->binding);
239 if (err < 0)
240 goto err1;
241
242 if (set->size == 0)
243 set->size = 0xffff;
244
245 priv->set = set;
246 return 0;
247
248err1:
249 if (priv->expr != NULL)
250 nft_expr_destroy(ctx, priv->expr);
251 return err;
252}
253
254static void nft_dynset_deactivate(const struct nft_ctx *ctx,
255 const struct nft_expr *expr,
256 enum nft_trans_phase phase)
257{
258 struct nft_dynset *priv = nft_expr_priv(expr);
259
260 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
261}
262
263static void nft_dynset_activate(const struct nft_ctx *ctx,
264 const struct nft_expr *expr)
265{
266 struct nft_dynset *priv = nft_expr_priv(expr);
267
268 priv->set->use++;
269}
270
271static void nft_dynset_destroy(const struct nft_ctx *ctx,
272 const struct nft_expr *expr)
273{
274 struct nft_dynset *priv = nft_expr_priv(expr);
275
276 if (priv->expr != NULL)
277 nft_expr_destroy(ctx, priv->expr);
278
279 nf_tables_destroy_set(ctx, priv->set);
280}
281
282static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
283{
284 const struct nft_dynset *priv = nft_expr_priv(expr);
285 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
286
287 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
288 goto nla_put_failure;
289 if (priv->set->flags & NFT_SET_MAP &&
290 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
291 goto nla_put_failure;
292 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
293 goto nla_put_failure;
294 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
295 goto nla_put_failure;
296 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
297 cpu_to_be64(jiffies_to_msecs(priv->timeout)),
298 NFTA_DYNSET_PAD))
299 goto nla_put_failure;
300 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
301 goto nla_put_failure;
302 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
303 goto nla_put_failure;
304 return 0;
305
306nla_put_failure:
307 return -1;
308}
309
310static const struct nft_expr_ops nft_dynset_ops = {
311 .type = &nft_dynset_type,
312 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
313 .eval = nft_dynset_eval,
314 .init = nft_dynset_init,
315 .destroy = nft_dynset_destroy,
316 .activate = nft_dynset_activate,
317 .deactivate = nft_dynset_deactivate,
318 .dump = nft_dynset_dump,
319};
320
321struct nft_expr_type nft_dynset_type __read_mostly = {
322 .name = "dynset",
323 .ops = &nft_dynset_ops,
324 .policy = nft_dynset_policy,
325 .maxattr = NFTA_DYNSET_MAX,
326 .owner = THIS_MODULE,
327};