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 if (priv->flags & NFTA_FIB_F_IIF) {
39 hooks |= (1 << NF_INET_LOCAL_IN) |
40 (1 << NF_INET_FORWARD);
41 }
42 break;
43 case NFT_FIB_RESULT_ADDRTYPE:
44 if (priv->flags & NFTA_FIB_F_IIF)
45 hooks = (1 << NF_INET_PRE_ROUTING) |
46 (1 << NF_INET_LOCAL_IN) |
47 (1 << NF_INET_FORWARD);
48 else if (priv->flags & NFTA_FIB_F_OIF)
49 hooks = (1 << NF_INET_LOCAL_OUT) |
50 (1 << NF_INET_POST_ROUTING) |
51 (1 << NF_INET_FORWARD);
52 else
53 hooks = (1 << NF_INET_LOCAL_IN) |
54 (1 << NF_INET_LOCAL_OUT) |
55 (1 << NF_INET_FORWARD) |
56 (1 << NF_INET_PRE_ROUTING) |
57 (1 << NF_INET_POST_ROUTING);
58
59 break;
60 default:
61 return -EINVAL;
62 }
63
64 return nft_chain_validate_hooks(ctx->chain, hooks);
65 }
66 EXPORT_SYMBOL_GPL(nft_fib_validate);
67
nft_fib_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])68 int nft_fib_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
69 const struct nlattr * const tb[])
70 {
71 struct nft_fib *priv = nft_expr_priv(expr);
72 unsigned int len;
73 int err;
74
75 if (!tb[NFTA_FIB_DREG] || !tb[NFTA_FIB_RESULT] || !tb[NFTA_FIB_FLAGS])
76 return -EINVAL;
77
78 priv->flags = ntohl(nla_get_be32(tb[NFTA_FIB_FLAGS]));
79
80 if (priv->flags == 0 || (priv->flags & ~NFTA_FIB_F_ALL))
81 return -EINVAL;
82
83 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) ==
84 (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR))
85 return -EINVAL;
86 if ((priv->flags & (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) ==
87 (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF))
88 return -EINVAL;
89 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 0)
90 return -EINVAL;
91
92 priv->result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
93
94 switch (priv->result) {
95 case NFT_FIB_RESULT_OIF:
96 if (priv->flags & NFTA_FIB_F_OIF)
97 return -EINVAL;
98 len = sizeof(int);
99 break;
100 case NFT_FIB_RESULT_OIFNAME:
101 if (priv->flags & NFTA_FIB_F_OIF)
102 return -EINVAL;
103 len = IFNAMSIZ;
104 break;
105 case NFT_FIB_RESULT_ADDRTYPE:
106 len = sizeof(u32);
107 break;
108 default:
109 return -EINVAL;
110 }
111
112 err = nft_parse_register_store(ctx, tb[NFTA_FIB_DREG], &priv->dreg,
113 NULL, NFT_DATA_VALUE, len);
114 if (err < 0)
115 return err;
116
117 return 0;
118 }
119 EXPORT_SYMBOL_GPL(nft_fib_init);
120
nft_fib_dump(struct sk_buff * skb,const struct nft_expr * expr)121 int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr)
122 {
123 const struct nft_fib *priv = nft_expr_priv(expr);
124
125 if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg))
126 return -1;
127
128 if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result)))
129 return -1;
130
131 if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags)))
132 return -1;
133
134 return 0;
135 }
136 EXPORT_SYMBOL_GPL(nft_fib_dump);
137
nft_fib_store_result(void * reg,const struct nft_fib * priv,const struct net_device * dev)138 void nft_fib_store_result(void *reg, const struct nft_fib *priv,
139 const struct net_device *dev)
140 {
141 u32 *dreg = reg;
142 int index;
143
144 switch (priv->result) {
145 case NFT_FIB_RESULT_OIF:
146 index = dev ? dev->ifindex : 0;
147 *dreg = (priv->flags & NFTA_FIB_F_PRESENT) ? !!index : index;
148 break;
149 case NFT_FIB_RESULT_OIFNAME:
150 if (priv->flags & NFTA_FIB_F_PRESENT)
151 *dreg = !!dev;
152 else
153 strncpy(reg, dev ? dev->name : "", IFNAMSIZ);
154 break;
155 default:
156 WARN_ON_ONCE(1);
157 *dreg = 0;
158 break;
159 }
160 }
161 EXPORT_SYMBOL_GPL(nft_fib_store_result);
162
nft_fib_reduce(struct nft_regs_track * track,const struct nft_expr * expr)163 bool nft_fib_reduce(struct nft_regs_track *track,
164 const struct nft_expr *expr)
165 {
166 const struct nft_fib *priv = nft_expr_priv(expr);
167 unsigned int len = NFT_REG32_SIZE;
168 const struct nft_fib *fib;
169
170 switch (priv->result) {
171 case NFT_FIB_RESULT_OIF:
172 break;
173 case NFT_FIB_RESULT_OIFNAME:
174 if (priv->flags & NFTA_FIB_F_PRESENT)
175 len = NFT_REG32_SIZE;
176 else
177 len = IFNAMSIZ;
178 break;
179 case NFT_FIB_RESULT_ADDRTYPE:
180 break;
181 default:
182 WARN_ON_ONCE(1);
183 break;
184 }
185
186 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
187 nft_reg_track_update(track, expr, priv->dreg, len);
188 return false;
189 }
190
191 fib = nft_expr_priv(track->regs[priv->dreg].selector);
192 if (priv->result != fib->result ||
193 priv->flags != fib->flags) {
194 nft_reg_track_update(track, expr, priv->dreg, len);
195 return false;
196 }
197
198 if (!track->regs[priv->dreg].bitwise)
199 return true;
200
201 return false;
202 }
203 EXPORT_SYMBOL_GPL(nft_fib_reduce);
204
205 MODULE_LICENSE("GPL");
206 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
207