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11#include <asm/unaligned.h>
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/netlink.h>
16#include <linux/netfilter.h>
17#include <linux/netfilter/nf_tables.h>
18#include <net/netfilter/nf_tables_core.h>
19#include <net/netfilter/nf_tables.h>
20
21struct nft_byteorder {
22 enum nft_registers sreg:8;
23 enum nft_registers dreg:8;
24 enum nft_byteorder_ops op:8;
25 u8 len;
26 u8 size;
27};
28
29static void nft_byteorder_eval(const struct nft_expr *expr,
30 struct nft_regs *regs,
31 const struct nft_pktinfo *pkt)
32{
33 const struct nft_byteorder *priv = nft_expr_priv(expr);
34 u32 *src = ®s->data[priv->sreg];
35 u32 *dst = ®s->data[priv->dreg];
36 union { u32 u32; u16 u16; } *s, *d;
37 unsigned int i;
38
39 s = (void *)src;
40 d = (void *)dst;
41
42 switch (priv->size) {
43 case 8: {
44 u64 src64;
45
46 switch (priv->op) {
47 case NFT_BYTEORDER_NTOH:
48 for (i = 0; i < priv->len / 8; i++) {
49 src64 = get_unaligned((u64 *)&src[i]);
50 put_unaligned_be64(src64, &dst[i]);
51 }
52 break;
53 case NFT_BYTEORDER_HTON:
54 for (i = 0; i < priv->len / 8; i++) {
55 src64 = get_unaligned_be64(&src[i]);
56 put_unaligned(src64, (u64 *)&dst[i]);
57 }
58 break;
59 }
60 break;
61 }
62 case 4:
63 switch (priv->op) {
64 case NFT_BYTEORDER_NTOH:
65 for (i = 0; i < priv->len / 4; i++)
66 d[i].u32 = ntohl((__force __be32)s[i].u32);
67 break;
68 case NFT_BYTEORDER_HTON:
69 for (i = 0; i < priv->len / 4; i++)
70 d[i].u32 = (__force __u32)htonl(s[i].u32);
71 break;
72 }
73 break;
74 case 2:
75 switch (priv->op) {
76 case NFT_BYTEORDER_NTOH:
77 for (i = 0; i < priv->len / 2; i++)
78 d[i].u16 = ntohs((__force __be16)s[i].u16);
79 break;
80 case NFT_BYTEORDER_HTON:
81 for (i = 0; i < priv->len / 2; i++)
82 d[i].u16 = (__force __u16)htons(s[i].u16);
83 break;
84 }
85 break;
86 }
87}
88
89static const struct nla_policy nft_byteorder_policy[NFTA_BYTEORDER_MAX + 1] = {
90 [NFTA_BYTEORDER_SREG] = { .type = NLA_U32 },
91 [NFTA_BYTEORDER_DREG] = { .type = NLA_U32 },
92 [NFTA_BYTEORDER_OP] = { .type = NLA_U32 },
93 [NFTA_BYTEORDER_LEN] = { .type = NLA_U32 },
94 [NFTA_BYTEORDER_SIZE] = { .type = NLA_U32 },
95};
96
97static int nft_byteorder_init(const struct nft_ctx *ctx,
98 const struct nft_expr *expr,
99 const struct nlattr * const tb[])
100{
101 struct nft_byteorder *priv = nft_expr_priv(expr);
102 u32 size, len;
103 int err;
104
105 if (tb[NFTA_BYTEORDER_SREG] == NULL ||
106 tb[NFTA_BYTEORDER_DREG] == NULL ||
107 tb[NFTA_BYTEORDER_LEN] == NULL ||
108 tb[NFTA_BYTEORDER_SIZE] == NULL ||
109 tb[NFTA_BYTEORDER_OP] == NULL)
110 return -EINVAL;
111
112 priv->op = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_OP]));
113 switch (priv->op) {
114 case NFT_BYTEORDER_NTOH:
115 case NFT_BYTEORDER_HTON:
116 break;
117 default:
118 return -EINVAL;
119 }
120
121 err = nft_parse_u32_check(tb[NFTA_BYTEORDER_SIZE], U8_MAX, &size);
122 if (err < 0)
123 return err;
124
125 priv->size = size;
126
127 switch (priv->size) {
128 case 2:
129 case 4:
130 case 8:
131 break;
132 default:
133 return -EINVAL;
134 }
135
136 priv->sreg = nft_parse_register(tb[NFTA_BYTEORDER_SREG]);
137 err = nft_parse_u32_check(tb[NFTA_BYTEORDER_LEN], U8_MAX, &len);
138 if (err < 0)
139 return err;
140
141 priv->len = len;
142
143 err = nft_validate_register_load(priv->sreg, priv->len);
144 if (err < 0)
145 return err;
146
147 priv->dreg = nft_parse_register(tb[NFTA_BYTEORDER_DREG]);
148 return nft_validate_register_store(ctx, priv->dreg, NULL,
149 NFT_DATA_VALUE, priv->len);
150}
151
152static int nft_byteorder_dump(struct sk_buff *skb, const struct nft_expr *expr)
153{
154 const struct nft_byteorder *priv = nft_expr_priv(expr);
155
156 if (nft_dump_register(skb, NFTA_BYTEORDER_SREG, priv->sreg))
157 goto nla_put_failure;
158 if (nft_dump_register(skb, NFTA_BYTEORDER_DREG, priv->dreg))
159 goto nla_put_failure;
160 if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op)))
161 goto nla_put_failure;
162 if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len)))
163 goto nla_put_failure;
164 if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size)))
165 goto nla_put_failure;
166 return 0;
167
168nla_put_failure:
169 return -1;
170}
171
172static struct nft_expr_type nft_byteorder_type;
173static const struct nft_expr_ops nft_byteorder_ops = {
174 .type = &nft_byteorder_type,
175 .size = NFT_EXPR_SIZE(sizeof(struct nft_byteorder)),
176 .eval = nft_byteorder_eval,
177 .init = nft_byteorder_init,
178 .dump = nft_byteorder_dump,
179};
180
181static struct nft_expr_type nft_byteorder_type __read_mostly = {
182 .name = "byteorder",
183 .ops = &nft_byteorder_ops,
184 .policy = nft_byteorder_policy,
185 .maxattr = NFTA_BYTEORDER_MAX,
186 .owner = THIS_MODULE,
187};
188
189int __init nft_byteorder_module_init(void)
190{
191 return nft_register_expr(&nft_byteorder_type);
192}
193
194void nft_byteorder_module_exit(void)
195{
196 nft_unregister_expr(&nft_byteorder_type);
197}
198
