Commit | Line | Data |
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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 | ||
10870dd8 FW |
27 | void nft_cmp_eval(const struct nft_expr *expr, |
28 | struct nft_regs *regs, | |
29 | const struct nft_pktinfo *pkt) | |
96518518 PM |
30 | { |
31 | const struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
32 | int d; | |
33 | ||
e562d860 | 34 | d = memcmp(®s->data[priv->sreg], &priv->data, priv->len); |
96518518 PM |
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; | |
e8542dce | 47 | /* fall through */ |
96518518 PM |
48 | case NFT_CMP_LTE: |
49 | if (d > 0) | |
50 | goto mismatch; | |
51 | break; | |
52 | case NFT_CMP_GT: | |
53 | if (d == 0) | |
54 | goto mismatch; | |
e8542dce | 55 | /* fall through */ |
96518518 PM |
56 | case NFT_CMP_GTE: |
57 | if (d < 0) | |
58 | goto mismatch; | |
59 | break; | |
60 | } | |
61 | return; | |
62 | ||
63 | mismatch: | |
a55e22e9 | 64 | regs->verdict.code = NFT_BREAK; |
96518518 PM |
65 | } |
66 | ||
67 | static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = { | |
68 | [NFTA_CMP_SREG] = { .type = NLA_U32 }, | |
69 | [NFTA_CMP_OP] = { .type = NLA_U32 }, | |
70 | [NFTA_CMP_DATA] = { .type = NLA_NESTED }, | |
71 | }; | |
72 | ||
73 | static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr, | |
74 | const struct nlattr * const tb[]) | |
75 | { | |
76 | struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
77 | struct nft_data_desc desc; | |
78 | int err; | |
79 | ||
d0a11fc3 PM |
80 | err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc, |
81 | tb[NFTA_CMP_DATA]); | |
fa5950e4 FW |
82 | if (err < 0) |
83 | return err; | |
96518518 | 84 | |
b1c96ed3 | 85 | priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]); |
d07db988 PM |
86 | err = nft_validate_register_load(priv->sreg, desc.len); |
87 | if (err < 0) | |
88 | return err; | |
89 | ||
90 | priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); | |
96518518 PM |
91 | priv->len = desc.len; |
92 | return 0; | |
93 | } | |
94 | ||
95 | static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
96 | { | |
97 | const struct nft_cmp_expr *priv = nft_expr_priv(expr); | |
98 | ||
b1c96ed3 | 99 | if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg)) |
96518518 PM |
100 | goto nla_put_failure; |
101 | if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op))) | |
102 | goto nla_put_failure; | |
103 | ||
104 | if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data, | |
105 | NFT_DATA_VALUE, priv->len) < 0) | |
106 | goto nla_put_failure; | |
107 | return 0; | |
108 | ||
109 | nla_put_failure: | |
110 | return -1; | |
111 | } | |
112 | ||
ef1f7df9 PM |
113 | static const struct nft_expr_ops nft_cmp_ops = { |
114 | .type = &nft_cmp_type, | |
96518518 | 115 | .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)), |
96518518 PM |
116 | .eval = nft_cmp_eval, |
117 | .init = nft_cmp_init, | |
118 | .dump = nft_cmp_dump, | |
ef1f7df9 PM |
119 | }; |
120 | ||
cb7dbfd0 PM |
121 | static int nft_cmp_fast_init(const struct nft_ctx *ctx, |
122 | const struct nft_expr *expr, | |
123 | const struct nlattr * const tb[]) | |
124 | { | |
125 | struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); | |
126 | struct nft_data_desc desc; | |
127 | struct nft_data data; | |
128 | u32 mask; | |
129 | int err; | |
130 | ||
d0a11fc3 PM |
131 | err = nft_data_init(NULL, &data, sizeof(data), &desc, |
132 | tb[NFTA_CMP_DATA]); | |
fa5950e4 FW |
133 | if (err < 0) |
134 | return err; | |
cb7dbfd0 | 135 | |
b1c96ed3 | 136 | priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]); |
d07db988 PM |
137 | err = nft_validate_register_load(priv->sreg, desc.len); |
138 | if (err < 0) | |
139 | return err; | |
140 | ||
141 | desc.len *= BITS_PER_BYTE; | |
b855d416 | 142 | mask = nft_cmp_fast_mask(desc.len); |
d07db988 | 143 | |
cb7dbfd0 PM |
144 | priv->data = data.data[0] & mask; |
145 | priv->len = desc.len; | |
146 | return 0; | |
147 | } | |
148 | ||
149 | static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
150 | { | |
151 | const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); | |
152 | struct nft_data data; | |
153 | ||
b1c96ed3 | 154 | if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg)) |
cb7dbfd0 PM |
155 | goto nla_put_failure; |
156 | if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ))) | |
157 | goto nla_put_failure; | |
158 | ||
159 | data.data[0] = priv->data; | |
160 | if (nft_data_dump(skb, NFTA_CMP_DATA, &data, | |
161 | NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0) | |
162 | goto nla_put_failure; | |
163 | return 0; | |
164 | ||
165 | nla_put_failure: | |
166 | return -1; | |
167 | } | |
168 | ||
169 | const struct nft_expr_ops nft_cmp_fast_ops = { | |
170 | .type = &nft_cmp_type, | |
171 | .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)), | |
172 | .eval = NULL, /* inlined */ | |
173 | .init = nft_cmp_fast_init, | |
174 | .dump = nft_cmp_fast_dump, | |
175 | }; | |
176 | ||
0ca743a5 PNA |
177 | static const struct nft_expr_ops * |
178 | nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) | |
cb7dbfd0 PM |
179 | { |
180 | struct nft_data_desc desc; | |
181 | struct nft_data data; | |
cb7dbfd0 PM |
182 | enum nft_cmp_ops op; |
183 | int err; | |
184 | ||
185 | if (tb[NFTA_CMP_SREG] == NULL || | |
186 | tb[NFTA_CMP_OP] == NULL || | |
187 | tb[NFTA_CMP_DATA] == NULL) | |
188 | return ERR_PTR(-EINVAL); | |
189 | ||
cb7dbfd0 PM |
190 | op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); |
191 | switch (op) { | |
192 | case NFT_CMP_EQ: | |
193 | case NFT_CMP_NEQ: | |
194 | case NFT_CMP_LT: | |
195 | case NFT_CMP_LTE: | |
196 | case NFT_CMP_GT: | |
197 | case NFT_CMP_GTE: | |
198 | break; | |
199 | default: | |
200 | return ERR_PTR(-EINVAL); | |
201 | } | |
202 | ||
d0a11fc3 PM |
203 | err = nft_data_init(NULL, &data, sizeof(data), &desc, |
204 | tb[NFTA_CMP_DATA]); | |
cb7dbfd0 PM |
205 | if (err < 0) |
206 | return ERR_PTR(err); | |
207 | ||
71df14b0 PNA |
208 | if (desc.type != NFT_DATA_VALUE) { |
209 | err = -EINVAL; | |
210 | goto err1; | |
211 | } | |
212 | ||
cb7dbfd0 PM |
213 | if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ) |
214 | return &nft_cmp_fast_ops; | |
71df14b0 PNA |
215 | |
216 | return &nft_cmp_ops; | |
217 | err1: | |
59105446 | 218 | nft_data_release(&data, desc.type); |
71df14b0 | 219 | return ERR_PTR(-EINVAL); |
cb7dbfd0 PM |
220 | } |
221 | ||
4e24877e | 222 | struct nft_expr_type nft_cmp_type __read_mostly = { |
ef1f7df9 | 223 | .name = "cmp", |
cb7dbfd0 | 224 | .select_ops = nft_cmp_select_ops, |
96518518 PM |
225 | .policy = nft_cmp_policy, |
226 | .maxattr = NFTA_CMP_MAX, | |
ef1f7df9 | 227 | .owner = THIS_MODULE, |
96518518 | 228 | }; |