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96518518 | 1 | /* |
ef1f7df9 | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
96518518 PM |
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 | * Development of this code funded by Astaro AG (http://www.astaro.com/) | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/netlink.h> | |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/netfilter/nf_tables.h> | |
17 | #include <net/netfilter/nf_tables_core.h> | |
18 | #include <net/netfilter/nf_tables.h> | |
19 | ||
20 | struct nft_cmp_expr { | |
21 | struct nft_data data; | |
22 | enum nft_registers sreg:8; | |
23 | u8 len; | |
24 | enum nft_cmp_ops op:8; | |
25 | }; | |
26 | ||
27 | static void nft_cmp_eval(const struct nft_expr *expr, | |
28 | struct nft_data data[NFT_REG_MAX + 1], | |
29 | const struct nft_pktinfo *pkt) | |
30 | { | |
31 | const struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
32 | int d; | |
33 | ||
34 | d = nft_data_cmp(&data[priv->sreg], &priv->data, priv->len); | |
35 | switch (priv->op) { | |
36 | case NFT_CMP_EQ: | |
37 | if (d != 0) | |
38 | goto mismatch; | |
39 | break; | |
40 | case NFT_CMP_NEQ: | |
41 | if (d == 0) | |
42 | goto mismatch; | |
43 | break; | |
44 | case NFT_CMP_LT: | |
45 | if (d == 0) | |
46 | goto mismatch; | |
47 | case NFT_CMP_LTE: | |
48 | if (d > 0) | |
49 | goto mismatch; | |
50 | break; | |
51 | case NFT_CMP_GT: | |
52 | if (d == 0) | |
53 | goto mismatch; | |
54 | case NFT_CMP_GTE: | |
55 | if (d < 0) | |
56 | goto mismatch; | |
57 | break; | |
58 | } | |
59 | return; | |
60 | ||
61 | mismatch: | |
62 | data[NFT_REG_VERDICT].verdict = NFT_BREAK; | |
63 | } | |
64 | ||
65 | static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = { | |
66 | [NFTA_CMP_SREG] = { .type = NLA_U32 }, | |
67 | [NFTA_CMP_OP] = { .type = NLA_U32 }, | |
68 | [NFTA_CMP_DATA] = { .type = NLA_NESTED }, | |
69 | }; | |
70 | ||
71 | static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr, | |
72 | const struct nlattr * const tb[]) | |
73 | { | |
74 | struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
75 | struct nft_data_desc desc; | |
76 | int err; | |
77 | ||
96518518 | 78 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); |
96518518 | 79 | priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); |
96518518 PM |
80 | |
81 | err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]); | |
cb7dbfd0 | 82 | BUG_ON(err < 0); |
96518518 PM |
83 | |
84 | priv->len = desc.len; | |
85 | return 0; | |
86 | } | |
87 | ||
88 | static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
89 | { | |
90 | const struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
91 | ||
92 | if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg))) | |
93 | goto nla_put_failure; | |
94 | if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op))) | |
95 | goto nla_put_failure; | |
96 | ||
97 | if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data, | |
98 | NFT_DATA_VALUE, priv->len) < 0) | |
99 | goto nla_put_failure; | |
100 | return 0; | |
101 | ||
102 | nla_put_failure: | |
103 | return -1; | |
104 | } | |
105 | ||
ef1f7df9 PM |
106 | static struct nft_expr_type nft_cmp_type; |
107 | static const struct nft_expr_ops nft_cmp_ops = { | |
108 | .type = &nft_cmp_type, | |
96518518 | 109 | .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)), |
96518518 PM |
110 | .eval = nft_cmp_eval, |
111 | .init = nft_cmp_init, | |
112 | .dump = nft_cmp_dump, | |
ef1f7df9 PM |
113 | }; |
114 | ||
cb7dbfd0 PM |
115 | static int nft_cmp_fast_init(const struct nft_ctx *ctx, |
116 | const struct nft_expr *expr, | |
117 | const struct nlattr * const tb[]) | |
118 | { | |
119 | struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); | |
120 | struct nft_data_desc desc; | |
121 | struct nft_data data; | |
122 | u32 mask; | |
123 | int err; | |
124 | ||
125 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); | |
126 | ||
127 | err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]); | |
128 | BUG_ON(err < 0); | |
129 | desc.len *= BITS_PER_BYTE; | |
130 | ||
b855d416 | 131 | mask = nft_cmp_fast_mask(desc.len); |
cb7dbfd0 PM |
132 | priv->data = data.data[0] & mask; |
133 | priv->len = desc.len; | |
134 | return 0; | |
135 | } | |
136 | ||
137 | static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
138 | { | |
139 | const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); | |
140 | struct nft_data data; | |
141 | ||
142 | if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg))) | |
143 | goto nla_put_failure; | |
144 | if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ))) | |
145 | goto nla_put_failure; | |
146 | ||
147 | data.data[0] = priv->data; | |
148 | if (nft_data_dump(skb, NFTA_CMP_DATA, &data, | |
149 | NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0) | |
150 | goto nla_put_failure; | |
151 | return 0; | |
152 | ||
153 | nla_put_failure: | |
154 | return -1; | |
155 | } | |
156 | ||
157 | const struct nft_expr_ops nft_cmp_fast_ops = { | |
158 | .type = &nft_cmp_type, | |
159 | .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)), | |
160 | .eval = NULL, /* inlined */ | |
161 | .init = nft_cmp_fast_init, | |
162 | .dump = nft_cmp_fast_dump, | |
163 | }; | |
164 | ||
0ca743a5 PNA |
165 | static const struct nft_expr_ops * |
166 | nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) | |
cb7dbfd0 PM |
167 | { |
168 | struct nft_data_desc desc; | |
169 | struct nft_data data; | |
170 | enum nft_registers sreg; | |
171 | enum nft_cmp_ops op; | |
172 | int err; | |
173 | ||
174 | if (tb[NFTA_CMP_SREG] == NULL || | |
175 | tb[NFTA_CMP_OP] == NULL || | |
176 | tb[NFTA_CMP_DATA] == NULL) | |
177 | return ERR_PTR(-EINVAL); | |
178 | ||
179 | sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); | |
180 | err = nft_validate_input_register(sreg); | |
181 | if (err < 0) | |
182 | return ERR_PTR(err); | |
183 | ||
184 | op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); | |
185 | switch (op) { | |
186 | case NFT_CMP_EQ: | |
187 | case NFT_CMP_NEQ: | |
188 | case NFT_CMP_LT: | |
189 | case NFT_CMP_LTE: | |
190 | case NFT_CMP_GT: | |
191 | case NFT_CMP_GTE: | |
192 | break; | |
193 | default: | |
194 | return ERR_PTR(-EINVAL); | |
195 | } | |
196 | ||
197 | err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]); | |
198 | if (err < 0) | |
199 | return ERR_PTR(err); | |
200 | ||
201 | if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ) | |
202 | return &nft_cmp_fast_ops; | |
203 | else | |
204 | return &nft_cmp_ops; | |
205 | } | |
206 | ||
ef1f7df9 PM |
207 | static struct nft_expr_type nft_cmp_type __read_mostly = { |
208 | .name = "cmp", | |
cb7dbfd0 | 209 | .select_ops = nft_cmp_select_ops, |
96518518 PM |
210 | .policy = nft_cmp_policy, |
211 | .maxattr = NFTA_CMP_MAX, | |
ef1f7df9 | 212 | .owner = THIS_MODULE, |
96518518 PM |
213 | }; |
214 | ||
215 | int __init nft_cmp_module_init(void) | |
216 | { | |
ef1f7df9 | 217 | return nft_register_expr(&nft_cmp_type); |
96518518 PM |
218 | } |
219 | ||
220 | void nft_cmp_module_exit(void) | |
221 | { | |
ef1f7df9 | 222 | nft_unregister_expr(&nft_cmp_type); |
96518518 | 223 | } |