summaryrefslogtreecommitdiff
path: root/net/netfilter/nft_fib.c
blob: b58f62195ff3ee04aebcf62a166349ff3a1f1285 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Generic part shared by ipv4 and ipv6 backends.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_fib.h>

#define NFTA_FIB_F_ALL (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR | \
			NFTA_FIB_F_MARK | NFTA_FIB_F_IIF | NFTA_FIB_F_OIF | \
			NFTA_FIB_F_PRESENT)

const struct nla_policy nft_fib_policy[NFTA_FIB_MAX + 1] = {
	[NFTA_FIB_DREG]		= { .type = NLA_U32 },
	[NFTA_FIB_RESULT]	= { .type = NLA_U32 },
	[NFTA_FIB_FLAGS]	=
		NLA_POLICY_MASK(NLA_BE32, NFTA_FIB_F_ALL),
};
EXPORT_SYMBOL(nft_fib_policy);

int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
		     const struct nft_data **data)
{
	const struct nft_fib *priv = nft_expr_priv(expr);
	unsigned int hooks;

	switch (priv->result) {
	case NFT_FIB_RESULT_OIF:
	case NFT_FIB_RESULT_OIFNAME:
		hooks = (1 << NF_INET_PRE_ROUTING) |
			(1 << NF_INET_LOCAL_IN) |
			(1 << NF_INET_FORWARD);
		break;
	case NFT_FIB_RESULT_ADDRTYPE:
		if (priv->flags & NFTA_FIB_F_IIF)
			hooks = (1 << NF_INET_PRE_ROUTING) |
				(1 << NF_INET_LOCAL_IN) |
				(1 << NF_INET_FORWARD);
		else if (priv->flags & NFTA_FIB_F_OIF)
			hooks = (1 << NF_INET_LOCAL_OUT) |
				(1 << NF_INET_POST_ROUTING) |
				(1 << NF_INET_FORWARD);
		else
			hooks = (1 << NF_INET_LOCAL_IN) |
				(1 << NF_INET_LOCAL_OUT) |
				(1 << NF_INET_FORWARD) |
				(1 << NF_INET_PRE_ROUTING) |
				(1 << NF_INET_POST_ROUTING);

		break;
	default:
		return -EINVAL;
	}

	return nft_chain_validate_hooks(ctx->chain, hooks);
}
EXPORT_SYMBOL_GPL(nft_fib_validate);

int nft_fib_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
		 const struct nlattr * const tb[])
{
	struct nft_fib *priv = nft_expr_priv(expr);
	unsigned int len;
	int err;

	if (!tb[NFTA_FIB_DREG] || !tb[NFTA_FIB_RESULT] || !tb[NFTA_FIB_FLAGS])
		return -EINVAL;

	priv->flags = ntohl(nla_get_be32(tb[NFTA_FIB_FLAGS]));

	if (priv->flags == 0)
		return -EINVAL;

	if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) ==
			   (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR))
		return -EINVAL;
	if ((priv->flags & (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) ==
			   (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF))
		return -EINVAL;
	if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 0)
		return -EINVAL;

	priv->result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));

	switch (priv->result) {
	case NFT_FIB_RESULT_OIF:
		if (priv->flags & NFTA_FIB_F_OIF)
			return -EINVAL;
		len = sizeof(int);
		break;
	case NFT_FIB_RESULT_OIFNAME:
		if (priv->flags & NFTA_FIB_F_OIF)
			return -EINVAL;
		len = IFNAMSIZ;
		break;
	case NFT_FIB_RESULT_ADDRTYPE:
		len = sizeof(u32);
		break;
	default:
		return -EINVAL;
	}

	err = nft_parse_register_store(ctx, tb[NFTA_FIB_DREG], &priv->dreg,
				       NULL, NFT_DATA_VALUE, len);
	if (err < 0)
		return err;

	return 0;
}
EXPORT_SYMBOL_GPL(nft_fib_init);

int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr, bool reset)
{
	const struct nft_fib *priv = nft_expr_priv(expr);

	if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg))
		return -1;

	if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result)))
		return -1;

	if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags)))
		return -1;

	return 0;
}
EXPORT_SYMBOL_GPL(nft_fib_dump);

void nft_fib_store_result(void *reg, const struct nft_fib *priv,
			  const struct net_device *dev)
{
	u32 *dreg = reg;
	int index;

	switch (priv->result) {
	case NFT_FIB_RESULT_OIF:
		index = dev ? dev->ifindex : 0;
		if (priv->flags & NFTA_FIB_F_PRESENT)
			nft_reg_store8(dreg, !!index);
		else
			*dreg = index;

		break;
	case NFT_FIB_RESULT_OIFNAME:
		if (priv->flags & NFTA_FIB_F_PRESENT)
			nft_reg_store8(dreg, !!dev);
		else
			strscpy_pad(reg, dev ? dev->name : "", IFNAMSIZ);
		break;
	default:
		WARN_ON_ONCE(1);
		*dreg = 0;
		break;
	}
}
EXPORT_SYMBOL_GPL(nft_fib_store_result);

bool nft_fib_reduce(struct nft_regs_track *track,
		    const struct nft_expr *expr)
{
	const struct nft_fib *priv = nft_expr_priv(expr);
	unsigned int len = NFT_REG32_SIZE;
	const struct nft_fib *fib;

	switch (priv->result) {
	case NFT_FIB_RESULT_OIF:
		break;
	case NFT_FIB_RESULT_OIFNAME:
		if (priv->flags & NFTA_FIB_F_PRESENT)
			len = NFT_REG32_SIZE;
		else
			len = IFNAMSIZ;
		break;
	case NFT_FIB_RESULT_ADDRTYPE:
	     break;
	default:
		WARN_ON_ONCE(1);
		break;
	}

	if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
		nft_reg_track_update(track, expr, priv->dreg, len);
		return false;
	}

	fib = nft_expr_priv(track->regs[priv->dreg].selector);
	if (priv->result != fib->result ||
	    priv->flags != fib->flags) {
		nft_reg_track_update(track, expr, priv->dreg, len);
		return false;
	}

	if (!track->regs[priv->dreg].bitwise)
		return true;

	return false;
}
EXPORT_SYMBOL_GPL(nft_fib_reduce);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Query routing table from nftables");
MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");