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 void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
32 struct nft_regs *regs)
33{
34 const struct nft_dynset *priv = nft_expr_priv(expr);
35 struct nft_set_ext *ext;
36 u64 timeout;
37 void *elem;
38
39 if (set->size && !atomic_add_unless(&set->nelems, 1, set->size))
40 return NULL;
41
42 timeout = priv->timeout ? : set->timeout;
43 elem = nft_set_elem_init(set, &priv->tmpl,
44 ®s->data[priv->sreg_key],
45 ®s->data[priv->sreg_data],
46 timeout, GFP_ATOMIC);
47 if (elem == NULL)
48 goto err1;
49
50 ext = nft_set_elem_ext(set, elem);
51 if (priv->expr != NULL &&
52 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
53 goto err2;
54
55 return elem;
56
57err2:
58 nft_set_elem_destroy(set, elem, false);
59err1:
60 if (set->size)
61 atomic_dec(&set->nelems);
62 return NULL;
63}
64
65static void nft_dynset_eval(const struct nft_expr *expr,
66 struct nft_regs *regs,
67 const struct nft_pktinfo *pkt)
68{
69 const struct nft_dynset *priv = nft_expr_priv(expr);
70 struct nft_set *set = priv->set;
71 const struct nft_set_ext *ext;
72 const struct nft_expr *sexpr;
73 u64 timeout;
74
75 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
76 expr, regs, &ext)) {
77 sexpr = NULL;
78 if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
79 sexpr = nft_set_ext_expr(ext);
80
81 if (priv->op == NFT_DYNSET_OP_UPDATE &&
82 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
83 timeout = priv->timeout ? : set->timeout;
84 *nft_set_ext_expiration(ext) = jiffies + timeout;
85 } else if (sexpr == NULL)
86 goto out;
87
88 if (sexpr != NULL)
89 sexpr->ops->eval(sexpr, regs, pkt);
90
91 if (priv->invert)
92 regs->verdict.code = NFT_BREAK;
93 return;
94 }
95out:
96 if (!priv->invert)
97 regs->verdict.code = NFT_BREAK;
98}
99
100static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
101 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING,
102 .len = NFT_SET_MAXNAMELEN - 1 },
103 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
104 [NFTA_DYNSET_OP] = { .type = NLA_U32 },
105 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
106 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
107 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
108 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
109 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
110};
111
112static int nft_dynset_init(const struct nft_ctx *ctx,
113 const struct nft_expr *expr,
114 const struct nlattr * const tb[])
115{
116 struct nft_dynset *priv = nft_expr_priv(expr);
117 u8 genmask = nft_genmask_next(ctx->net);
118 struct nft_set *set;
119 u64 timeout;
120 int err;
121
122 if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
123 tb[NFTA_DYNSET_OP] == NULL ||
124 tb[NFTA_DYNSET_SREG_KEY] == NULL)
125 return -EINVAL;
126
127 if (tb[NFTA_DYNSET_FLAGS]) {
128 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
129
130 if (flags & ~NFT_DYNSET_F_INV)
131 return -EINVAL;
132 if (flags & NFT_DYNSET_F_INV)
133 priv->invert = true;
134 }
135
136 set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME],
137 genmask);
138 if (IS_ERR(set)) {
139 if (tb[NFTA_DYNSET_SET_ID])
140 set = nf_tables_set_lookup_byid(ctx->net,
141 tb[NFTA_DYNSET_SET_ID],
142 genmask);
143 if (IS_ERR(set))
144 return PTR_ERR(set);
145 }
146
147 if (set->ops->update == NULL)
148 return -EOPNOTSUPP;
149
150 if (set->flags & NFT_SET_CONSTANT)
151 return -EBUSY;
152
153 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
154 switch (priv->op) {
155 case NFT_DYNSET_OP_ADD:
156 break;
157 case NFT_DYNSET_OP_UPDATE:
158 if (!(set->flags & NFT_SET_TIMEOUT))
159 return -EOPNOTSUPP;
160 break;
161 default:
162 return -EOPNOTSUPP;
163 }
164
165 timeout = 0;
166 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
167 if (!(set->flags & NFT_SET_TIMEOUT))
168 return -EINVAL;
169 timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64(
170 tb[NFTA_DYNSET_TIMEOUT])));
171 }
172
173 priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
174 err = nft_validate_register_load(priv->sreg_key, set->klen);;
175 if (err < 0)
176 return err;
177
178 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
179 if (!(set->flags & NFT_SET_MAP))
180 return -EINVAL;
181 if (set->dtype == NFT_DATA_VERDICT)
182 return -EOPNOTSUPP;
183
184 priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
185 err = nft_validate_register_load(priv->sreg_data, set->dlen);
186 if (err < 0)
187 return err;
188 } else if (set->flags & NFT_SET_MAP)
189 return -EINVAL;
190
191 if (tb[NFTA_DYNSET_EXPR] != NULL) {
192 if (!(set->flags & NFT_SET_EVAL))
193 return -EINVAL;
194 if (!(set->flags & NFT_SET_ANONYMOUS))
195 return -EOPNOTSUPP;
196
197 priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
198 if (IS_ERR(priv->expr))
199 return PTR_ERR(priv->expr);
200
201 err = -EOPNOTSUPP;
202 if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
203 goto err1;
204 } else if (set->flags & NFT_SET_EVAL)
205 return -EINVAL;
206
207 nft_set_ext_prepare(&priv->tmpl);
208 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
209 if (set->flags & NFT_SET_MAP)
210 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
211 if (priv->expr != NULL)
212 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
213 priv->expr->ops->size);
214 if (set->flags & NFT_SET_TIMEOUT) {
215 if (timeout || set->timeout)
216 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
217 }
218
219 priv->timeout = timeout;
220
221 err = nf_tables_bind_set(ctx, set, &priv->binding);
222 if (err < 0)
223 goto err1;
224
225 priv->set = set;
226 return 0;
227
228err1:
229 if (priv->expr != NULL)
230 nft_expr_destroy(ctx, priv->expr);
231 return err;
232}
233
234static void nft_dynset_destroy(const struct nft_ctx *ctx,
235 const struct nft_expr *expr)
236{
237 struct nft_dynset *priv = nft_expr_priv(expr);
238
239 nf_tables_unbind_set(ctx, priv->set, &priv->binding);
240 if (priv->expr != NULL)
241 nft_expr_destroy(ctx, priv->expr);
242}
243
244static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
245{
246 const struct nft_dynset *priv = nft_expr_priv(expr);
247 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
248
249 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
250 goto nla_put_failure;
251 if (priv->set->flags & NFT_SET_MAP &&
252 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
253 goto nla_put_failure;
254 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
255 goto nla_put_failure;
256 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
257 goto nla_put_failure;
258 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT,
259 cpu_to_be64(jiffies_to_msecs(priv->timeout)),
260 NFTA_DYNSET_PAD))
261 goto nla_put_failure;
262 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
263 goto nla_put_failure;
264 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
265 goto nla_put_failure;
266 return 0;
267
268nla_put_failure:
269 return -1;
270}
271
272static const struct nft_expr_ops nft_dynset_ops = {
273 .type = &nft_dynset_type,
274 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
275 .eval = nft_dynset_eval,
276 .init = nft_dynset_init,
277 .destroy = nft_dynset_destroy,
278 .dump = nft_dynset_dump,
279};
280
281struct nft_expr_type nft_dynset_type __read_mostly = {
282 .name = "dynset",
283 .ops = &nft_dynset_ops,
284 .policy = nft_dynset_policy,
285 .maxattr = NFTA_DYNSET_MAX,
286 .owner = THIS_MODULE,
287};