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
|
/*
* (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 "network.h"
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#ifndef ssizeof
#define ssizeof(x) (int)sizeof(x)
#endif
static void parse_u8(struct nf_conntrack *ct, int attr, void *data);
static void parse_u16(struct nf_conntrack *ct, int attr, void *data);
static void parse_u32(struct nf_conntrack *ct, int attr, void *data);
static void parse_group(struct nf_conntrack *ct, int attr, void *data);
static void parse_nat_seq_adj(struct nf_conntrack *ct, int attr, void *data);
struct parser {
void (*parse)(struct nf_conntrack *ct, int attr, void *data);
int attr;
int size;
};
static struct parser h[NTA_MAX] = {
[NTA_IPV4] = {
.parse = parse_group,
.attr = ATTR_GRP_ORIG_IPV4,
.size = NTA_SIZE(sizeof(struct nfct_attr_grp_ipv4)),
},
[NTA_IPV6] = {
.parse = parse_group,
.attr = ATTR_GRP_ORIG_IPV6,
.size = NTA_SIZE(sizeof(struct nfct_attr_grp_ipv6)),
},
[NTA_PORT] = {
.parse = parse_group,
.attr = ATTR_GRP_ORIG_PORT,
.size = NTA_SIZE(sizeof(struct nfct_attr_grp_port)),
},
[NTA_L4PROTO] = {
.parse = parse_u8,
.attr = ATTR_L4PROTO,
.size = NTA_SIZE(sizeof(uint8_t)),
},
[NTA_STATE] = {
.parse = parse_u8,
.attr = ATTR_TCP_STATE,
.size = NTA_SIZE(sizeof(uint8_t)),
},
[NTA_STATUS] = {
.parse = parse_u32,
.attr = ATTR_STATUS,
.size = NTA_SIZE(sizeof(uint32_t)),
},
[NTA_MARK] = {
.parse = parse_u32,
.attr = ATTR_MARK,
.size = NTA_SIZE(sizeof(uint32_t)),
},
[NTA_TIMEOUT] = {
.parse = parse_u32,
.attr = ATTR_TIMEOUT,
.size = NTA_SIZE(sizeof(uint32_t)),
},
[NTA_MASTER_IPV4] = {
.parse = parse_group,
.attr = ATTR_GRP_MASTER_IPV4,
.size = NTA_SIZE(sizeof(struct nfct_attr_grp_ipv4)),
},
[NTA_MASTER_IPV6] = {
.parse = parse_group,
.attr = ATTR_GRP_MASTER_IPV6,
.size = NTA_SIZE(sizeof(struct nfct_attr_grp_ipv6)),
},
[NTA_MASTER_L4PROTO] = {
.parse = parse_u8,
.attr = ATTR_MASTER_L4PROTO,
.size = NTA_SIZE(sizeof(uint8_t)),
},
[NTA_MASTER_PORT] = {
.parse = parse_group,
.attr = ATTR_GRP_MASTER_PORT,
.size = NTA_SIZE(sizeof(struct nfct_attr_grp_port)),
},
[NTA_SNAT_IPV4] = {
.parse = parse_u32,
.attr = ATTR_SNAT_IPV4,
.size = NTA_SIZE(sizeof(uint32_t)),
},
[NTA_DNAT_IPV4] = {
.parse = parse_u32,
.attr = ATTR_DNAT_IPV4,
.size = NTA_SIZE(sizeof(uint32_t)),
},
[NTA_SPAT_PORT] = {
.parse = parse_u16,
.attr = ATTR_SNAT_PORT,
.size = NTA_SIZE(sizeof(uint16_t)),
},
[NTA_DPAT_PORT] = {
.parse = parse_u16,
.attr = ATTR_SNAT_PORT,
.size = NTA_SIZE(sizeof(uint16_t)),
},
[NTA_NAT_SEQ_ADJ] = {
.parse = parse_nat_seq_adj,
.size = NTA_SIZE(sizeof(struct nta_attr_natseqadj)),
},
};
static void
parse_u8(struct nf_conntrack *ct, int attr, void *data)
{
uint8_t *value = (uint8_t *) data;
nfct_set_attr_u8(ct, h[attr].attr, *value);
}
static void
parse_u16(struct nf_conntrack *ct, int attr, void *data)
{
uint16_t *value = (uint16_t *) data;
nfct_set_attr_u16(ct, h[attr].attr, ntohs(*value));
}
static void
parse_u32(struct nf_conntrack *ct, int attr, void *data)
{
uint32_t *value = (uint32_t *) data;
nfct_set_attr_u32(ct, h[attr].attr, ntohl(*value));
}
static void
parse_group(struct nf_conntrack *ct, int attr, void *data)
{
nfct_set_attr_grp(ct, h[attr].attr, data);
}
static void
parse_nat_seq_adj(struct nf_conntrack *ct, int attr, void *data)
{
struct nta_attr_natseqadj *this = data;
nfct_set_attr_u32(ct, ATTR_ORIG_NAT_SEQ_CORRECTION_POS,
ntohl(this->orig_seq_correction_pos));
nfct_set_attr_u32(ct, ATTR_ORIG_NAT_SEQ_OFFSET_BEFORE,
ntohl(this->orig_seq_correction_pos));
nfct_set_attr_u32(ct, ATTR_ORIG_NAT_SEQ_OFFSET_AFTER,
ntohl(this->orig_seq_correction_pos));
nfct_set_attr_u32(ct, ATTR_REPL_NAT_SEQ_CORRECTION_POS,
ntohl(this->orig_seq_correction_pos));
nfct_set_attr_u32(ct, ATTR_REPL_NAT_SEQ_OFFSET_BEFORE,
ntohl(this->orig_seq_correction_pos));
nfct_set_attr_u32(ct, ATTR_REPL_NAT_SEQ_OFFSET_AFTER,
ntohl(this->orig_seq_correction_pos));
}
int parse_payload(struct nf_conntrack *ct, struct nethdr *net, size_t remain)
{
int len;
struct netattr *attr;
if (remain < net->len)
return -1;
len = net->len - NETHDR_SIZ;
attr = NETHDR_DATA(net);
while (len > ssizeof(struct netattr)) {
ATTR_NETWORK2HOST(attr);
if (attr->nta_len > len)
return -1;
if (attr->nta_len != h[attr->nta_attr].size)
return -1;
if (h[attr->nta_attr].parse == NULL) {
attr = NTA_NEXT(attr, len);
continue;
}
h[attr->nta_attr].parse(ct, attr->nta_attr, NTA_DATA(attr));
attr = NTA_NEXT(attr, len);
}
return 0;
}
|
