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22fe54d5 PM |
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 | ||
19 | struct 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 | u64 timeout; | |
3e135cd4 | 26 | struct nft_expr *expr; |
22fe54d5 PM |
27 | struct nft_set_binding binding; |
28 | }; | |
29 | ||
30 | static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr, | |
a55e22e9 | 31 | struct nft_regs *regs) |
22fe54d5 PM |
32 | { |
33 | const struct nft_dynset *priv = nft_expr_priv(expr); | |
3e135cd4 | 34 | struct nft_set_ext *ext; |
22fe54d5 PM |
35 | u64 timeout; |
36 | void *elem; | |
37 | ||
38 | if (set->size && !atomic_add_unless(&set->nelems, 1, set->size)) | |
39 | return NULL; | |
40 | ||
41 | timeout = priv->timeout ? : set->timeout; | |
42 | elem = nft_set_elem_init(set, &priv->tmpl, | |
a55e22e9 PM |
43 | ®s->data[priv->sreg_key], |
44 | ®s->data[priv->sreg_data], | |
22fe54d5 PM |
45 | timeout, GFP_ATOMIC); |
46 | if (elem == NULL) { | |
47 | if (set->size) | |
48 | atomic_dec(&set->nelems); | |
3e135cd4 | 49 | return NULL; |
22fe54d5 | 50 | } |
3e135cd4 PM |
51 | |
52 | ext = nft_set_elem_ext(set, elem); | |
53 | if (priv->expr != NULL) | |
54 | nft_expr_clone(nft_set_ext_expr(ext), priv->expr); | |
55 | ||
22fe54d5 PM |
56 | return elem; |
57 | } | |
58 | ||
59 | static void nft_dynset_eval(const struct nft_expr *expr, | |
a55e22e9 | 60 | struct nft_regs *regs, |
22fe54d5 PM |
61 | const struct nft_pktinfo *pkt) |
62 | { | |
63 | const struct nft_dynset *priv = nft_expr_priv(expr); | |
64 | struct nft_set *set = priv->set; | |
65 | const struct nft_set_ext *ext; | |
3e135cd4 | 66 | const struct nft_expr *sexpr; |
22fe54d5 PM |
67 | u64 timeout; |
68 | ||
a55e22e9 PM |
69 | if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new, |
70 | expr, regs, &ext)) { | |
3e135cd4 PM |
71 | sexpr = NULL; |
72 | if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) | |
73 | sexpr = nft_set_ext_expr(ext); | |
74 | ||
22fe54d5 PM |
75 | if (priv->op == NFT_DYNSET_OP_UPDATE && |
76 | nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) { | |
77 | timeout = priv->timeout ? : set->timeout; | |
78 | *nft_set_ext_expiration(ext) = jiffies + timeout; | |
3e135cd4 PM |
79 | } else if (sexpr == NULL) |
80 | goto out; | |
22fe54d5 | 81 | |
3e135cd4 PM |
82 | if (sexpr != NULL) |
83 | sexpr->ops->eval(sexpr, regs, pkt); | |
84 | return; | |
85 | } | |
86 | out: | |
a55e22e9 | 87 | regs->verdict.code = NFT_BREAK; |
22fe54d5 PM |
88 | } |
89 | ||
90 | static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = { | |
91 | [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING }, | |
92 | [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 }, | |
93 | [NFTA_DYNSET_OP] = { .type = NLA_U32 }, | |
94 | [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 }, | |
95 | [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 }, | |
96 | [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 }, | |
3e135cd4 | 97 | [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED }, |
22fe54d5 PM |
98 | }; |
99 | ||
100 | static int nft_dynset_init(const struct nft_ctx *ctx, | |
101 | const struct nft_expr *expr, | |
102 | const struct nlattr * const tb[]) | |
103 | { | |
104 | struct nft_dynset *priv = nft_expr_priv(expr); | |
105 | struct nft_set *set; | |
106 | u64 timeout; | |
107 | int err; | |
108 | ||
109 | if (tb[NFTA_DYNSET_SET_NAME] == NULL || | |
110 | tb[NFTA_DYNSET_OP] == NULL || | |
111 | tb[NFTA_DYNSET_SREG_KEY] == NULL) | |
112 | return -EINVAL; | |
113 | ||
114 | set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME]); | |
115 | if (IS_ERR(set)) { | |
116 | if (tb[NFTA_DYNSET_SET_ID]) | |
117 | set = nf_tables_set_lookup_byid(ctx->net, | |
118 | tb[NFTA_DYNSET_SET_ID]); | |
119 | if (IS_ERR(set)) | |
120 | return PTR_ERR(set); | |
121 | } | |
122 | ||
123 | if (set->flags & NFT_SET_CONSTANT) | |
124 | return -EBUSY; | |
125 | ||
126 | priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP])); | |
127 | switch (priv->op) { | |
128 | case NFT_DYNSET_OP_ADD: | |
129 | break; | |
130 | case NFT_DYNSET_OP_UPDATE: | |
131 | if (!(set->flags & NFT_SET_TIMEOUT)) | |
132 | return -EOPNOTSUPP; | |
133 | break; | |
134 | default: | |
135 | return -EOPNOTSUPP; | |
136 | } | |
137 | ||
138 | timeout = 0; | |
139 | if (tb[NFTA_DYNSET_TIMEOUT] != NULL) { | |
140 | if (!(set->flags & NFT_SET_TIMEOUT)) | |
141 | return -EINVAL; | |
142 | timeout = be64_to_cpu(nla_get_be64(tb[NFTA_DYNSET_TIMEOUT])); | |
143 | } | |
144 | ||
b1c96ed3 | 145 | priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]); |
d07db988 | 146 | err = nft_validate_register_load(priv->sreg_key, set->klen);; |
22fe54d5 PM |
147 | if (err < 0) |
148 | return err; | |
149 | ||
150 | if (tb[NFTA_DYNSET_SREG_DATA] != NULL) { | |
151 | if (!(set->flags & NFT_SET_MAP)) | |
152 | return -EINVAL; | |
153 | if (set->dtype == NFT_DATA_VERDICT) | |
154 | return -EOPNOTSUPP; | |
155 | ||
b1c96ed3 | 156 | priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]); |
d07db988 | 157 | err = nft_validate_register_load(priv->sreg_data, set->dlen); |
22fe54d5 PM |
158 | if (err < 0) |
159 | return err; | |
160 | } else if (set->flags & NFT_SET_MAP) | |
161 | return -EINVAL; | |
162 | ||
3e135cd4 PM |
163 | if (tb[NFTA_DYNSET_EXPR] != NULL) { |
164 | if (!(set->flags & NFT_SET_EVAL)) | |
165 | return -EINVAL; | |
166 | if (!(set->flags & NFT_SET_ANONYMOUS)) | |
167 | return -EOPNOTSUPP; | |
168 | ||
169 | priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]); | |
170 | if (IS_ERR(priv->expr)) | |
171 | return PTR_ERR(priv->expr); | |
172 | ||
173 | err = -EOPNOTSUPP; | |
174 | if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL)) | |
175 | goto err1; | |
176 | } else if (set->flags & NFT_SET_EVAL) | |
177 | return -EINVAL; | |
178 | ||
22fe54d5 PM |
179 | nft_set_ext_prepare(&priv->tmpl); |
180 | nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen); | |
181 | if (set->flags & NFT_SET_MAP) | |
182 | nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen); | |
3e135cd4 PM |
183 | if (priv->expr != NULL) |
184 | nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR, | |
185 | priv->expr->ops->size); | |
22fe54d5 PM |
186 | if (set->flags & NFT_SET_TIMEOUT) { |
187 | if (timeout || set->timeout) | |
188 | nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION); | |
189 | } | |
190 | ||
191 | priv->timeout = timeout; | |
192 | ||
193 | err = nf_tables_bind_set(ctx, set, &priv->binding); | |
194 | if (err < 0) | |
3e135cd4 | 195 | goto err1; |
22fe54d5 PM |
196 | |
197 | priv->set = set; | |
198 | return 0; | |
3e135cd4 PM |
199 | |
200 | err1: | |
201 | if (priv->expr != NULL) | |
202 | nft_expr_destroy(ctx, priv->expr); | |
203 | return err; | |
22fe54d5 PM |
204 | } |
205 | ||
206 | static void nft_dynset_destroy(const struct nft_ctx *ctx, | |
207 | const struct nft_expr *expr) | |
208 | { | |
209 | struct nft_dynset *priv = nft_expr_priv(expr); | |
210 | ||
211 | nf_tables_unbind_set(ctx, priv->set, &priv->binding); | |
3e135cd4 PM |
212 | if (priv->expr != NULL) |
213 | nft_expr_destroy(ctx, priv->expr); | |
22fe54d5 PM |
214 | } |
215 | ||
216 | static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
217 | { | |
218 | const struct nft_dynset *priv = nft_expr_priv(expr); | |
219 | ||
b1c96ed3 | 220 | if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key)) |
22fe54d5 PM |
221 | goto nla_put_failure; |
222 | if (priv->set->flags & NFT_SET_MAP && | |
b1c96ed3 | 223 | nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data)) |
22fe54d5 PM |
224 | goto nla_put_failure; |
225 | if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op))) | |
226 | goto nla_put_failure; | |
227 | if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name)) | |
228 | goto nla_put_failure; | |
229 | if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, cpu_to_be64(priv->timeout))) | |
230 | goto nla_put_failure; | |
3e135cd4 PM |
231 | if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr)) |
232 | goto nla_put_failure; | |
22fe54d5 PM |
233 | return 0; |
234 | ||
235 | nla_put_failure: | |
236 | return -1; | |
237 | } | |
238 | ||
239 | static struct nft_expr_type nft_dynset_type; | |
240 | static const struct nft_expr_ops nft_dynset_ops = { | |
241 | .type = &nft_dynset_type, | |
242 | .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)), | |
243 | .eval = nft_dynset_eval, | |
244 | .init = nft_dynset_init, | |
245 | .destroy = nft_dynset_destroy, | |
246 | .dump = nft_dynset_dump, | |
247 | }; | |
248 | ||
249 | static struct nft_expr_type nft_dynset_type __read_mostly = { | |
250 | .name = "dynset", | |
251 | .ops = &nft_dynset_ops, | |
252 | .policy = nft_dynset_policy, | |
253 | .maxattr = NFTA_DYNSET_MAX, | |
254 | .owner = THIS_MODULE, | |
255 | }; | |
256 | ||
257 | int __init nft_dynset_module_init(void) | |
258 | { | |
259 | return nft_register_expr(&nft_dynset_type); | |
260 | } | |
261 | ||
262 | void nft_dynset_module_exit(void) | |
263 | { | |
264 | nft_unregister_expr(&nft_dynset_type); | |
265 | } |