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