summaryrefslogtreecommitdiffstats
path: root/src/expr/masq.c
blob: b39a43a3c238c84e7df7edd35fa814419266501c (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
/*
 * (C) 2014 by Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.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 <arpa/inet.h>
#include <errno.h>
#include <inttypes.h>

#include <linux/netfilter/nf_tables.h>

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

struct nft_expr_masq {
	uint32_t	flags;
};

static int
nft_rule_expr_masq_set(struct nft_rule_expr *e, uint16_t type,
		       const void *data, uint32_t data_len)
{
	struct nft_expr_masq *masq = nft_expr_data(e);

	switch (type) {
	case NFT_EXPR_MASQ_FLAGS:
		masq->flags = *((uint32_t *)data);
		break;
	default:
		return -1;
	}
	return 0;
}

static const void *
nft_rule_expr_masq_get(const struct nft_rule_expr *e, uint16_t type,
		       uint32_t *data_len)
{
	struct nft_expr_masq *masq = nft_expr_data(e);

	switch (type) {
	case NFT_EXPR_MASQ_FLAGS:
		*data_len = sizeof(masq->flags);
		return &masq->flags;
	}
	return NULL;
}

static int nft_rule_expr_masq_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_MASQ_MAX) < 0)
		return MNL_CB_OK;

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

	tb[type] = attr;
	return MNL_CB_OK;
}

static void
nft_rule_expr_masq_build(struct nlmsghdr *nlh, struct nft_rule_expr *e)
{
	struct nft_expr_masq *masq = nft_expr_data(e);

	if (e->flags & (1 << NFT_EXPR_MASQ_FLAGS))
		mnl_attr_put_u32(nlh, NFTA_MASQ_FLAGS, htobe32(masq->flags));
}

static int
nft_rule_expr_masq_parse(struct nft_rule_expr *e, struct nlattr *attr)
{
	struct nft_expr_masq *masq = nft_expr_data(e);
	struct nlattr *tb[NFTA_MASQ_MAX+1] = {};

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

	if (tb[NFTA_MASQ_FLAGS]) {
		masq->flags = be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_FLAGS]));
		e->flags |= (1 << NFT_EXPR_MASQ_FLAGS);
	}

	return 0;
}

static int
nft_rule_expr_masq_json_parse(struct nft_rule_expr *e, json_t *root,
			      struct nft_parse_err *err)
{
#ifdef JSON_PARSING
	uint32_t flags;

	if (nft_jansson_parse_val(root, "flags", NFT_TYPE_U32, &flags,
				  err) == 0)
		nft_rule_expr_set_u32(e, NFT_EXPR_MASQ_FLAGS, flags);

	return 0;
#else
	errno = EOPNOTSUPP;
	return -1;
#endif
}

static int
nft_rule_expr_masq_xml_parse(struct nft_rule_expr *e, mxml_node_t *tree,
			     struct nft_parse_err *err)
{
#ifdef XML_PARSING
	uint32_t flags;

	if (nft_mxml_num_parse(tree, "flags", MXML_DESCEND_FIRST, BASE_DEC,
			       &flags, NFT_TYPE_U32, NFT_XML_MAND, err) == 0)
		nft_rule_expr_set_u32(e, NFT_EXPR_MASQ_FLAGS, flags);

	return 0;
#else
	errno = EOPNOTSUPP;
	return -1;
#endif
}
static int nft_rule_expr_masq_snprintf_json(char *buf, size_t len,
					    struct nft_rule_expr *e)
{
	int ret, size = len, offset = 0;
	struct nft_expr_masq *masq = nft_expr_data(e);

	if (e->flags & (1 << NFT_EXPR_MASQ_FLAGS)) {
		ret = snprintf(buf + offset, len, "\"flags\":%u", masq->flags);
		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
	}

	return offset;
}

static int nft_rule_expr_masq_snprintf_xml(char *buf, size_t len,
					   struct nft_rule_expr *e)
{
	int ret, size = len, offset = 0;
	struct nft_expr_masq *masq = nft_expr_data(e);

	if (e->flags & (1 << NFT_EXPR_MASQ_FLAGS)) {
		ret = snprintf(buf + offset, len, "<flags>%u</flags>",
			       masq->flags);
		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
	}

	return offset;
}

static int nft_rule_expr_masq_snprintf_default(char *buf, size_t len,
					       struct nft_rule_expr *e)
{
	struct nft_expr_masq *masq = nft_expr_data(e);

	if (e->flags & (1 << NFT_EXPR_MASQ_FLAGS))
		return snprintf(buf, len, "flags 0x%x ", masq->flags);

	return 0;
}

static int nft_rule_expr_masq_snprintf(char *buf, size_t len, uint32_t type,
				       uint32_t flags, struct nft_rule_expr *e)
{
	switch (type) {
	case NFT_OUTPUT_DEFAULT:
		return nft_rule_expr_masq_snprintf_default(buf, len, e);
	case NFT_OUTPUT_XML:
		return nft_rule_expr_masq_snprintf_xml(buf, len, e);
	case NFT_OUTPUT_JSON:
		return nft_rule_expr_masq_snprintf_json(buf, len, e);
	default:
		break;
	}
	return -1;
}

struct expr_ops expr_ops_masq = {
	.name		= "masq",
	.alloc_len	= sizeof(struct nft_expr_masq),
	.max_attr	= NFTA_MASQ_MAX,
	.set		= nft_rule_expr_masq_set,
	.get		= nft_rule_expr_masq_get,
	.parse		= nft_rule_expr_masq_parse,
	.build		= nft_rule_expr_masq_build,
	.snprintf	= nft_rule_expr_masq_snprintf,
	.xml_parse	= nft_rule_expr_masq_xml_parse,
	.json_parse	= nft_rule_expr_masq_json_parse,
};

static void __init expr_masq_init(void)
{
	nft_expr_ops_register(&expr_ops_masq);
}