2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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.
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
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>
22 enum nft_registers sreg:8;
24 enum nft_cmp_ops op:8;
27 static void nft_cmp_eval(const struct nft_expr *expr,
28 struct nft_regs *regs,
29 const struct nft_pktinfo *pkt)
31 const struct nft_cmp_expr *priv = nft_expr_priv(expr);
34 d = memcmp(®s->data[priv->sreg], &priv->data, priv->len);
62 regs->verdict.code = NFT_BREAK;
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 },
71 static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
72 const struct nlattr * const tb[])
74 struct nft_cmp_expr *priv = nft_expr_priv(expr);
75 struct nft_data_desc desc;
78 err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
82 priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
83 err = nft_validate_register_load(priv->sreg, desc.len);
87 if (desc.len > U8_MAX)
90 priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
95 static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr)
97 const struct nft_cmp_expr *priv = nft_expr_priv(expr);
99 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
100 goto nla_put_failure;
101 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
102 goto nla_put_failure;
104 if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
105 NFT_DATA_VALUE, priv->len) < 0)
106 goto nla_put_failure;
113 static struct nft_expr_type nft_cmp_type;
114 static const struct nft_expr_ops nft_cmp_ops = {
115 .type = &nft_cmp_type,
116 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
117 .eval = nft_cmp_eval,
118 .init = nft_cmp_init,
119 .dump = nft_cmp_dump,
122 static int nft_cmp_fast_init(const struct nft_ctx *ctx,
123 const struct nft_expr *expr,
124 const struct nlattr * const tb[])
126 struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
127 struct nft_data_desc desc;
128 struct nft_data data;
132 err = nft_data_init(NULL, &data, sizeof(data), &desc,
136 priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
137 err = nft_validate_register_load(priv->sreg, desc.len);
141 desc.len *= BITS_PER_BYTE;
142 mask = nft_cmp_fast_mask(desc.len);
144 priv->data = data.data[0] & mask;
145 priv->len = desc.len;
149 static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
151 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
152 struct nft_data data;
154 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
155 goto nla_put_failure;
156 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
157 goto nla_put_failure;
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;
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,
177 static const struct nft_expr_ops *
178 nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
180 struct nft_data_desc desc;
181 struct nft_data data;
185 if (tb[NFTA_CMP_SREG] == NULL ||
186 tb[NFTA_CMP_OP] == NULL ||
187 tb[NFTA_CMP_DATA] == NULL)
188 return ERR_PTR(-EINVAL);
190 op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
200 return ERR_PTR(-EINVAL);
203 err = nft_data_init(NULL, &data, sizeof(data), &desc,
208 if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
209 return &nft_cmp_fast_ops;
214 static struct nft_expr_type nft_cmp_type __read_mostly = {
216 .select_ops = nft_cmp_select_ops,
217 .policy = nft_cmp_policy,
218 .maxattr = NFTA_CMP_MAX,
219 .owner = THIS_MODULE,
222 int __init nft_cmp_module_init(void)
224 return nft_register_expr(&nft_cmp_type);
227 void nft_cmp_module_exit(void)
229 nft_unregister_expr(&nft_cmp_type);