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
|
/*
* (C) 2006-2007 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <string.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include "network.h"
static void addattr(struct netpld *pld, int attr, const void *data, size_t len)
{
struct netattr *nta;
int tlen = NTA_LENGTH(len);
nta = PLD_TAIL(pld);
nta->nta_attr = htons(attr);
nta->nta_len = htons(len);
memcpy(NTA_DATA(nta), data, len);
pld->len += NTA_ALIGN(tlen);
}
static void __build_u8(const struct nf_conntrack *ct,
struct netpld *pld,
int attr)
{
uint8_t data = nfct_get_attr_u8(ct, attr);
addattr(pld, attr, &data, sizeof(uint8_t));
}
static void __build_u16(const struct nf_conntrack *ct,
struct netpld *pld,
int attr)
{
uint16_t data = nfct_get_attr_u16(ct, attr);
data = htons(data);
addattr(pld, attr, &data, sizeof(uint16_t));
}
static void __build_u32(const struct nf_conntrack *ct,
struct netpld *pld,
int attr)
{
uint32_t data = nfct_get_attr_u32(ct, attr);
data = htonl(data);
addattr(pld, attr, &data, sizeof(uint32_t));
}
static void __build_pointer_be(const struct nf_conntrack *ct,
struct netpld *pld,
int attr,
size_t size)
{
addattr(pld, attr, nfct_get_attr(ct, attr), size);
}
static void __nat_build_u32(uint32_t data, struct netpld *pld, int attr)
{
data = htonl(data);
addattr(pld, attr, &data, sizeof(uint32_t));
}
static void __nat_build_u16(uint16_t data, struct netpld *pld, int attr)
{
data = htons(data);
addattr(pld, attr, &data, sizeof(uint16_t));
}
/* XXX: ICMP not supported */
void build_netpld(struct nf_conntrack *ct, struct netpld *pld, int query)
{
if (nfct_attr_is_set(ct, ATTR_IPV4_SRC))
__build_pointer_be(ct, pld, ATTR_IPV4_SRC, sizeof(uint32_t));
if (nfct_attr_is_set(ct, ATTR_IPV4_DST))
__build_pointer_be(ct, pld, ATTR_IPV4_DST, sizeof(uint32_t));
if (nfct_attr_is_set(ct, ATTR_IPV6_SRC))
__build_pointer_be(ct, pld, ATTR_IPV6_SRC, sizeof(uint32_t)*4);
if (nfct_attr_is_set(ct, ATTR_IPV6_DST))
__build_pointer_be(ct, pld, ATTR_IPV6_DST, sizeof(uint32_t)*4);
if (nfct_attr_is_set(ct, ATTR_L3PROTO))
__build_u8(ct, pld, ATTR_L3PROTO);
if (nfct_attr_is_set(ct, ATTR_PORT_SRC))
__build_u16(ct, pld, ATTR_PORT_SRC);
if (nfct_attr_is_set(ct, ATTR_PORT_DST))
__build_u16(ct, pld, ATTR_PORT_DST);
if (nfct_attr_is_set(ct, ATTR_L4PROTO)) {
uint8_t proto;
__build_u8(ct, pld, ATTR_L4PROTO);
proto = nfct_get_attr_u8(ct, ATTR_L4PROTO);
if (proto == IPPROTO_TCP) {
if (nfct_attr_is_set(ct, ATTR_TCP_STATE))
__build_u8(ct, pld, ATTR_TCP_STATE);
}
}
if (nfct_attr_is_set(ct, ATTR_TIMEOUT))
__build_u32(ct, pld, ATTR_TIMEOUT);
if (nfct_attr_is_set(ct, ATTR_MARK))
__build_u32(ct, pld, ATTR_MARK);
if (nfct_attr_is_set(ct, ATTR_SECMARK))
__build_u32(ct, pld, ATTR_SECMARK);
if (nfct_attr_is_set(ct, ATTR_STATUS))
__build_u32(ct, pld, ATTR_STATUS);
/* setup the master conntrack */
if (nfct_attr_is_set(ct, ATTR_MASTER_IPV4_SRC))
__build_u32(ct, pld, ATTR_MASTER_IPV4_SRC);
if (nfct_attr_is_set(ct, ATTR_MASTER_IPV4_DST))
__build_u32(ct, pld, ATTR_MASTER_IPV4_DST);
if (nfct_attr_is_set(ct, ATTR_MASTER_L3PROTO))
__build_u8(ct, pld, ATTR_MASTER_L3PROTO);
if (nfct_attr_is_set(ct, ATTR_MASTER_PORT_SRC))
__build_u16(ct, pld, ATTR_MASTER_PORT_SRC);
if (nfct_attr_is_set(ct, ATTR_MASTER_PORT_DST))
__build_u16(ct, pld, ATTR_MASTER_PORT_DST);
if (nfct_attr_is_set(ct, ATTR_MASTER_L4PROTO))
__build_u8(ct, pld, ATTR_MASTER_L4PROTO);
/* NAT */
if (nfct_getobjopt(ct, NFCT_GOPT_IS_SNAT)) {
uint32_t data = nfct_get_attr_u32(ct, ATTR_REPL_IPV4_DST);
__nat_build_u32(data, pld, ATTR_SNAT_IPV4);
}
if (nfct_getobjopt(ct, NFCT_GOPT_IS_DNAT)) {
uint32_t data = nfct_get_attr_u32(ct, ATTR_REPL_IPV4_SRC);
__nat_build_u32(data, pld, ATTR_DNAT_IPV4);
}
if (nfct_getobjopt(ct, NFCT_GOPT_IS_SPAT)) {
uint16_t data = nfct_get_attr_u16(ct, ATTR_REPL_PORT_DST);
__nat_build_u16(data, pld, ATTR_SNAT_PORT);
}
if (nfct_getobjopt(ct, NFCT_GOPT_IS_DPAT)) {
uint16_t data = nfct_get_attr_u16(ct, ATTR_REPL_PORT_SRC);
__nat_build_u16(data, pld, ATTR_DNAT_PORT);
}
/* NAT sequence adjustment */
if (nfct_attr_is_set(ct, ATTR_ORIG_NAT_SEQ_CORRECTION_POS))
__build_u32(ct, pld, ATTR_ORIG_NAT_SEQ_CORRECTION_POS);
if (nfct_attr_is_set(ct, ATTR_ORIG_NAT_SEQ_OFFSET_BEFORE))
__build_u32(ct, pld, ATTR_ORIG_NAT_SEQ_OFFSET_BEFORE);
if (nfct_attr_is_set(ct, ATTR_ORIG_NAT_SEQ_OFFSET_AFTER))
__build_u32(ct, pld, ATTR_ORIG_NAT_SEQ_OFFSET_AFTER);
if (nfct_attr_is_set(ct, ATTR_REPL_NAT_SEQ_CORRECTION_POS))
__build_u32(ct, pld, ATTR_REPL_NAT_SEQ_CORRECTION_POS);
if (nfct_attr_is_set(ct, ATTR_REPL_NAT_SEQ_OFFSET_BEFORE))
__build_u32(ct, pld, ATTR_REPL_NAT_SEQ_OFFSET_BEFORE);
if (nfct_attr_is_set(ct, ATTR_REPL_NAT_SEQ_OFFSET_AFTER))
__build_u32(ct, pld, ATTR_REPL_NAT_SEQ_OFFSET_AFTER);
pld->query = query;
PLD_HOST2NETWORK(pld);
}
|
