1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Generic part shared by ipv4 and ipv6 backends.
5 */
6
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/netlink.h>
11 #include <linux/netfilter.h>
12 #include <linux/netfilter/nf_tables.h>
13 #include <net/netfilter/nf_tables_core.h>
14 #include <net/netfilter/nf_tables.h>
15 #include <net/netfilter/nft_fib.h>
16
17 const struct nla_policy nft_fib_policy[NFTA_FIB_MAX + 1] = {
18 [NFTA_FIB_DREG] = { .type = NLA_U32 },
19 [NFTA_FIB_RESULT] = { .type = NLA_U32 },
20 [NFTA_FIB_FLAGS] = { .type = NLA_U32 },
21 };
22 EXPORT_SYMBOL(nft_fib_policy);
23
24 #define NFTA_FIB_F_ALL (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR | \
25 NFTA_FIB_F_MARK | NFTA_FIB_F_IIF | NFTA_FIB_F_OIF | \
26 NFTA_FIB_F_PRESENT)
27
nft_fib_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** data)28 int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
29 const struct nft_data **data)
30 {
31 const struct nft_fib *priv = nft_expr_priv(expr);
32 unsigned int hooks;
33
34 switch (priv->result) {
35 case NFT_FIB_RESULT_OIF: /* fallthrough */
36 case NFT_FIB_RESULT_OIFNAME:
37 hooks = (1 << NF_INET_PRE_ROUTING);
38 break;
39 case NFT_FIB_RESULT_ADDRTYPE:
40 if (priv->flags & NFTA_FIB_F_IIF)
41 hooks = (1 << NF_INET_PRE_ROUTING) |
42 (1 << NF_INET_LOCAL_IN) |
43 (1 << NF_INET_FORWARD);
44 else if (priv->flags & NFTA_FIB_F_OIF)
45 hooks = (1 << NF_INET_LOCAL_OUT) |
46 (1 << NF_INET_POST_ROUTING) |
47 (1 << NF_INET_FORWARD);
48 else
49 hooks = (1 << NF_INET_LOCAL_IN) |
50 (1 << NF_INET_LOCAL_OUT) |
51 (1 << NF_INET_FORWARD) |
52 (1 << NF_INET_PRE_ROUTING) |
53 (1 << NF_INET_POST_ROUTING);
54
55 break;
56 default:
57 return -EINVAL;
58 }
59
60 return nft_chain_validate_hooks(ctx->chain, hooks);
61 }
62 EXPORT_SYMBOL_GPL(nft_fib_validate);
63
nft_fib_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])64 int nft_fib_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
65 const struct nlattr * const tb[])
66 {
67 struct nft_fib *priv = nft_expr_priv(expr);
68 unsigned int len;
69 int err;
70
71 if (!tb[NFTA_FIB_DREG] || !tb[NFTA_FIB_RESULT] || !tb[NFTA_FIB_FLAGS])
72 return -EINVAL;
73
74 priv->flags = ntohl(nla_get_be32(tb[NFTA_FIB_FLAGS]));
75
76 if (priv->flags == 0 || (priv->flags & ~NFTA_FIB_F_ALL))
77 return -EINVAL;
78
79 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) ==
80 (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR))
81 return -EINVAL;
82 if ((priv->flags & (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) ==
83 (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF))
84 return -EINVAL;
85 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 0)
86 return -EINVAL;
87
88 priv->result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
89 priv->dreg = nft_parse_register(tb[NFTA_FIB_DREG]);
90
91 switch (priv->result) {
92 case NFT_FIB_RESULT_OIF:
93 if (priv->flags & NFTA_FIB_F_OIF)
94 return -EINVAL;
95 len = sizeof(int);
96 break;
97 case NFT_FIB_RESULT_OIFNAME:
98 if (priv->flags & NFTA_FIB_F_OIF)
99 return -EINVAL;
100 len = IFNAMSIZ;
101 break;
102 case NFT_FIB_RESULT_ADDRTYPE:
103 len = sizeof(u32);
104 break;
105 default:
106 return -EINVAL;
107 }
108
109 err = nft_validate_register_store(ctx, priv->dreg, NULL,
110 NFT_DATA_VALUE, len);
111 if (err < 0)
112 return err;
113
114 return 0;
115 }
116 EXPORT_SYMBOL_GPL(nft_fib_init);
117
nft_fib_dump(struct sk_buff * skb,const struct nft_expr * expr)118 int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr)
119 {
120 const struct nft_fib *priv = nft_expr_priv(expr);
121
122 if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg))
123 return -1;
124
125 if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result)))
126 return -1;
127
128 if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags)))
129 return -1;
130
131 return 0;
132 }
133 EXPORT_SYMBOL_GPL(nft_fib_dump);
134
nft_fib_store_result(void * reg,const struct nft_fib * priv,const struct net_device * dev)135 void nft_fib_store_result(void *reg, const struct nft_fib *priv,
136 const struct net_device *dev)
137 {
138 u32 *dreg = reg;
139 int index;
140
141 switch (priv->result) {
142 case NFT_FIB_RESULT_OIF:
143 index = dev ? dev->ifindex : 0;
144 *dreg = (priv->flags & NFTA_FIB_F_PRESENT) ? !!index : index;
145 break;
146 case NFT_FIB_RESULT_OIFNAME:
147 if (priv->flags & NFTA_FIB_F_PRESENT)
148 *dreg = !!dev;
149 else
150 strncpy(reg, dev ? dev->name : "", IFNAMSIZ);
151 break;
152 default:
153 WARN_ON_ONCE(1);
154 *dreg = 0;
155 break;
156 }
157 }
158 EXPORT_SYMBOL_GPL(nft_fib_store_result);
159
160 MODULE_LICENSE("GPL");
161 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
162