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 #define NFTA_FIB_F_ALL (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR | \
18 NFTA_FIB_F_MARK | NFTA_FIB_F_IIF | NFTA_FIB_F_OIF | \
19 NFTA_FIB_F_PRESENT)
20
21 const struct nla_policy nft_fib_policy[NFTA_FIB_MAX + 1] = {
22 [NFTA_FIB_DREG] = { .type = NLA_U32 },
23 [NFTA_FIB_RESULT] = { .type = NLA_U32 },
24 [NFTA_FIB_FLAGS] =
25 NLA_POLICY_MASK(NLA_BE32, NFTA_FIB_F_ALL),
26 };
27 EXPORT_SYMBOL(nft_fib_policy);
28
nft_fib_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** data)29 int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
30 const struct nft_data **data)
31 {
32 const struct nft_fib *priv = nft_expr_priv(expr);
33 unsigned int hooks;
34
35 switch (priv->result) {
36 case NFT_FIB_RESULT_OIF:
37 case NFT_FIB_RESULT_OIFNAME:
38 hooks = (1 << NF_INET_PRE_ROUTING);
39 if (priv->flags & NFTA_FIB_F_IIF) {
40 hooks |= (1 << NF_INET_LOCAL_IN) |
41 (1 << NF_INET_FORWARD);
42 }
43 break;
44 case NFT_FIB_RESULT_ADDRTYPE:
45 if (priv->flags & NFTA_FIB_F_IIF)
46 hooks = (1 << NF_INET_PRE_ROUTING) |
47 (1 << NF_INET_LOCAL_IN) |
48 (1 << NF_INET_FORWARD);
49 else if (priv->flags & NFTA_FIB_F_OIF)
50 hooks = (1 << NF_INET_LOCAL_OUT) |
51 (1 << NF_INET_POST_ROUTING) |
52 (1 << NF_INET_FORWARD);
53 else
54 hooks = (1 << NF_INET_LOCAL_IN) |
55 (1 << NF_INET_LOCAL_OUT) |
56 (1 << NF_INET_FORWARD) |
57 (1 << NF_INET_PRE_ROUTING) |
58 (1 << NF_INET_POST_ROUTING);
59
60 break;
61 default:
62 return -EINVAL;
63 }
64
65 return nft_chain_validate_hooks(ctx->chain, hooks);
66 }
67 EXPORT_SYMBOL_GPL(nft_fib_validate);
68
nft_fib_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])69 int nft_fib_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
70 const struct nlattr * const tb[])
71 {
72 struct nft_fib *priv = nft_expr_priv(expr);
73 unsigned int len;
74 int err;
75
76 if (!tb[NFTA_FIB_DREG] || !tb[NFTA_FIB_RESULT] || !tb[NFTA_FIB_FLAGS])
77 return -EINVAL;
78
79 priv->flags = ntohl(nla_get_be32(tb[NFTA_FIB_FLAGS]));
80
81 if (priv->flags == 0)
82 return -EINVAL;
83
84 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) ==
85 (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR))
86 return -EINVAL;
87 if ((priv->flags & (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) ==
88 (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF))
89 return -EINVAL;
90 if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 0)
91 return -EINVAL;
92
93 priv->result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
94
95 switch (priv->result) {
96 case NFT_FIB_RESULT_OIF:
97 if (priv->flags & NFTA_FIB_F_OIF)
98 return -EINVAL;
99 len = sizeof(int);
100 break;
101 case NFT_FIB_RESULT_OIFNAME:
102 if (priv->flags & NFTA_FIB_F_OIF)
103 return -EINVAL;
104 len = IFNAMSIZ;
105 break;
106 case NFT_FIB_RESULT_ADDRTYPE:
107 len = sizeof(u32);
108 break;
109 default:
110 return -EINVAL;
111 }
112
113 err = nft_parse_register_store(ctx, tb[NFTA_FIB_DREG], &priv->dreg,
114 NULL, NFT_DATA_VALUE, len);
115 if (err < 0)
116 return err;
117
118 return 0;
119 }
120 EXPORT_SYMBOL_GPL(nft_fib_init);
121
nft_fib_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)122 int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr, bool reset)
123 {
124 const struct nft_fib *priv = nft_expr_priv(expr);
125
126 if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg))
127 return -1;
128
129 if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result)))
130 return -1;
131
132 if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags)))
133 return -1;
134
135 return 0;
136 }
137 EXPORT_SYMBOL_GPL(nft_fib_dump);
138
nft_fib_store_result(void * reg,const struct nft_fib * priv,const struct net_device * dev)139 void nft_fib_store_result(void *reg, const struct nft_fib *priv,
140 const struct net_device *dev)
141 {
142 u32 *dreg = reg;
143 int index;
144
145 switch (priv->result) {
146 case NFT_FIB_RESULT_OIF:
147 index = dev ? dev->ifindex : 0;
148 *dreg = (priv->flags & NFTA_FIB_F_PRESENT) ? !!index : index;
149 break;
150 case NFT_FIB_RESULT_OIFNAME:
151 if (priv->flags & NFTA_FIB_F_PRESENT)
152 *dreg = !!dev;
153 else
154 strscpy_pad(reg, dev ? dev->name : "", IFNAMSIZ);
155 break;
156 default:
157 WARN_ON_ONCE(1);
158 *dreg = 0;
159 break;
160 }
161 }
162 EXPORT_SYMBOL_GPL(nft_fib_store_result);
163
nft_fib_reduce(struct nft_regs_track * track,const struct nft_expr * expr)164 bool nft_fib_reduce(struct nft_regs_track *track,
165 const struct nft_expr *expr)
166 {
167 const struct nft_fib *priv = nft_expr_priv(expr);
168 unsigned int len = NFT_REG32_SIZE;
169 const struct nft_fib *fib;
170
171 switch (priv->result) {
172 case NFT_FIB_RESULT_OIF:
173 break;
174 case NFT_FIB_RESULT_OIFNAME:
175 if (priv->flags & NFTA_FIB_F_PRESENT)
176 len = NFT_REG32_SIZE;
177 else
178 len = IFNAMSIZ;
179 break;
180 case NFT_FIB_RESULT_ADDRTYPE:
181 break;
182 default:
183 WARN_ON_ONCE(1);
184 break;
185 }
186
187 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
188 nft_reg_track_update(track, expr, priv->dreg, len);
189 return false;
190 }
191
192 fib = nft_expr_priv(track->regs[priv->dreg].selector);
193 if (priv->result != fib->result ||
194 priv->flags != fib->flags) {
195 nft_reg_track_update(track, expr, priv->dreg, len);
196 return false;
197 }
198
199 if (!track->regs[priv->dreg].bitwise)
200 return true;
201
202 return false;
203 }
204 EXPORT_SYMBOL_GPL(nft_fib_reduce);
205
206 MODULE_LICENSE("GPL");
207 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
208
