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:
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
90 switch (priv->result) {
91 case NFT_FIB_RESULT_OIF:
92 if (priv->flags & NFTA_FIB_F_OIF)
93 return -EINVAL;
94 len = sizeof(int);
95 break;
96 case NFT_FIB_RESULT_OIFNAME:
97 if (priv->flags & NFTA_FIB_F_OIF)
98 return -EINVAL;
99 len = IFNAMSIZ;
100 break;
101 case NFT_FIB_RESULT_ADDRTYPE:
102 len = sizeof(u32);
103 break;
104 default:
105 return -EINVAL;
106 }
107
108 err = nft_parse_register_store(ctx, tb[NFTA_FIB_DREG], &priv->dreg,
109 NULL, NFT_DATA_VALUE, len);
110 if (err < 0)
111 return err;
112
113 return 0;
114 }
115 EXPORT_SYMBOL_GPL(nft_fib_init);
116
nft_fib_dump(struct sk_buff * skb,const struct nft_expr * expr)117 int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr)
118 {
119 const struct nft_fib *priv = nft_expr_priv(expr);
120
121 if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg))
122 return -1;
123
124 if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result)))
125 return -1;
126
127 if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags)))
128 return -1;
129
130 return 0;
131 }
132 EXPORT_SYMBOL_GPL(nft_fib_dump);
133
nft_fib_store_result(void * reg,const struct nft_fib * priv,const struct net_device * dev)134 void nft_fib_store_result(void *reg, const struct nft_fib *priv,
135 const struct net_device *dev)
136 {
137 u32 *dreg = reg;
138 int index;
139
140 switch (priv->result) {
141 case NFT_FIB_RESULT_OIF:
142 index = dev ? dev->ifindex : 0;
143 *dreg = (priv->flags & NFTA_FIB_F_PRESENT) ? !!index : index;
144 break;
145 case NFT_FIB_RESULT_OIFNAME:
146 if (priv->flags & NFTA_FIB_F_PRESENT)
147 *dreg = !!dev;
148 else
149 strncpy(reg, dev ? dev->name : "", IFNAMSIZ);
150 break;
151 default:
152 WARN_ON_ONCE(1);
153 *dreg = 0;
154 break;
155 }
156 }
157 EXPORT_SYMBOL_GPL(nft_fib_store_result);
158
159 MODULE_LICENSE("GPL");
160 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
161