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