summaryrefslogtreecommitdiffstats
path: root/src/expr/rt.c
blob: 695a6589b5c84c3cbbc7d5fe6789605be2b2fa0b (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
/*
 * Copyright (c) 2016 Anders K. Pedersen <akp@cohaesio.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <linux/netfilter/nf_tables.h>

#include "internal.h"
#include <libmnl/libmnl.h>
#include <libnftnl/expr.h>
#include <libnftnl/rule.h>

struct nftnl_expr_rt {
	enum nft_rt_keys	key;
	enum nft_registers	dreg;
};

static int
nftnl_expr_rt_set(struct nftnl_expr *e, uint16_t type,
		       const void *data, uint32_t data_len)
{
	struct nftnl_expr_rt *rt = nftnl_expr_data(e);

	switch (type) {
	case NFTNL_EXPR_RT_KEY:
		memcpy(&rt->key, data, sizeof(rt->key));
		break;
	case NFTNL_EXPR_RT_DREG:
		memcpy(&rt->dreg, data, sizeof(rt->dreg));
		break;
	default:
		return -1;
	}
	return 0;
}

static const void *
nftnl_expr_rt_get(const struct nftnl_expr *e, uint16_t type,
		       uint32_t *data_len)
{
	struct nftnl_expr_rt *rt = nftnl_expr_data(e);

	switch (type) {
	case NFTNL_EXPR_RT_KEY:
		*data_len = sizeof(rt->key);
		return &rt->key;
	case NFTNL_EXPR_RT_DREG:
		*data_len = sizeof(rt->dreg);
		return &rt->dreg;
	}
	return NULL;
}

static int nftnl_expr_rt_cb(const struct nlattr *attr, void *data)
{
	const struct nlattr **tb = data;
	int type = mnl_attr_get_type(attr);

	if (mnl_attr_type_valid(attr, NFTA_RT_MAX) < 0)
		return MNL_CB_OK;

	switch (type) {
	case NFTA_RT_KEY:
	case NFTA_RT_DREG:
		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
			abi_breakage();
		break;
	}

	tb[type] = attr;
	return MNL_CB_OK;
}

static void
nftnl_expr_rt_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
	struct nftnl_expr_rt *rt = nftnl_expr_data(e);

	if (e->flags & (1 << NFTNL_EXPR_RT_KEY))
		mnl_attr_put_u32(nlh, NFTA_RT_KEY, htonl(rt->key));
	if (e->flags & (1 << NFTNL_EXPR_RT_DREG))
		mnl_attr_put_u32(nlh, NFTA_RT_DREG, htonl(rt->dreg));
}

static int
nftnl_expr_rt_parse(struct nftnl_expr *e, struct nlattr *attr)
{
	struct nftnl_expr_rt *rt = nftnl_expr_data(e);
	struct nlattr *tb[NFTA_RT_MAX+1] = {};

	if (mnl_attr_parse_nested(attr, nftnl_expr_rt_cb, tb) < 0)
		return -1;

	if (tb[NFTA_RT_KEY]) {
		rt->key = ntohl(mnl_attr_get_u32(tb[NFTA_RT_KEY]));
		e->flags |= (1 << NFTNL_EXPR_RT_KEY);
	}
	if (tb[NFTA_RT_DREG]) {
		rt->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_RT_DREG]));
		e->flags |= (1 << NFTNL_EXPR_RT_DREG);
	}

	return 0;
}

static const char *rt_key2str_array[NFT_RT_MAX + 1] = {
	[NFT_RT_CLASSID]	= "classid",
	[NFT_RT_NEXTHOP4]	= "nexthop4",
	[NFT_RT_NEXTHOP6]	= "nexthop6",
	[NFT_RT_TCPMSS]		= "tcpmss",
	[NFT_RT_XFRM]		= "ipsec",
};

static const char *rt_key2str(uint8_t key)
{
	if (key <= NFT_RT_MAX)
		return rt_key2str_array[key];

	return "unknown";
}

static inline int str2rt_key(const char *str)
{
	int i;

	for (i = 0; i < NFT_RT_MAX; i++) {
		if (strcmp(str, rt_key2str_array[i]) == 0)
			return i;
	}

	errno = EINVAL;
	return -1;
}

static int
nftnl_expr_rt_snprintf(char *buf, size_t len,
		       uint32_t flags, const struct nftnl_expr *e)
{
	struct nftnl_expr_rt *rt = nftnl_expr_data(e);

	if (e->flags & (1 << NFTNL_EXPR_RT_DREG)) {
		return snprintf(buf, len, "load %s => reg %u ",
				rt_key2str(rt->key), rt->dreg);
	}
	return 0;
}

struct expr_ops expr_ops_rt = {
	.name		= "rt",
	.alloc_len	= sizeof(struct nftnl_expr_rt),
	.max_attr	= NFTA_RT_MAX,
	.set		= nftnl_expr_rt_set,
	.get		= nftnl_expr_rt_get,
	.parse		= nftnl_expr_rt_parse,
	.build		= nftnl_expr_rt_build,
	.output		= nftnl_expr_rt_snprintf,
};