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
211
212
213
214
215
216
217
|
/* Shared library add-on to iptables to add simple non load-balancing SNAT support. */
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <xtables.h>
#include <net/netfilter/nf_nat.h>
/* For 64bit kernel / 32bit userspace */
#include <linux/netfilter_ipv4/ipt_SAME.h>
static void SAME_help(void)
{
printf(
"SAME target options:\n"
" --to <ipaddr>-<ipaddr>\n"
" Addresses to map source to.\n"
" May be specified more than\n"
" once for multiple ranges.\n"
" --nodst\n"
" Don't use destination-ip in\n"
" source selection\n"
" --random\n"
" Randomize source port\n");
}
static const struct option SAME_opts[] = {
{ "to", 1, NULL, '1' },
{ "nodst", 0, NULL, '2'},
{ "random", 0, NULL, '3' },
{ .name = NULL }
};
static void SAME_init(struct xt_entry_target *t)
{
struct ipt_same_info *mr = (struct ipt_same_info *)t->data;
/* Set default to 0 */
mr->rangesize = 0;
mr->info = 0;
mr->ipnum = 0;
}
/* Parses range of IPs */
static void
parse_to(char *arg, struct nf_nat_range *range)
{
char *dash;
const struct in_addr *ip;
range->flags |= IP_NAT_RANGE_MAP_IPS;
dash = strchr(arg, '-');
if (dash)
*dash = '\0';
ip = xtables_numeric_to_ipaddr(arg);
if (!ip)
xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n",
arg);
range->min_ip = ip->s_addr;
if (dash) {
ip = xtables_numeric_to_ipaddr(dash+1);
if (!ip)
xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n",
dash+1);
}
range->max_ip = ip->s_addr;
if (dash)
if (range->min_ip > range->max_ip)
xtables_error(PARAMETER_PROBLEM, "Bad IP range \"%s-%s\"\n",
arg, dash+1);
}
#define IPT_SAME_OPT_TO 0x01
#define IPT_SAME_OPT_NODST 0x02
#define IPT_SAME_OPT_RANDOM 0x04
static int SAME_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_target **target)
{
struct ipt_same_info *mr
= (struct ipt_same_info *)(*target)->data;
unsigned int count;
switch (c) {
case '1':
if (mr->rangesize == IPT_SAME_MAX_RANGE)
xtables_error(PARAMETER_PROBLEM,
"Too many ranges specified, maximum "
"is %i ranges.\n",
IPT_SAME_MAX_RANGE);
if (xtables_check_inverse(optarg, &invert, NULL, 0, argv))
xtables_error(PARAMETER_PROBLEM,
"Unexpected `!' after --to");
parse_to(optarg, &mr->range[mr->rangesize]);
/* WTF do we need this for? */
if (*flags & IPT_SAME_OPT_RANDOM)
mr->range[mr->rangesize].flags
|= IP_NAT_RANGE_PROTO_RANDOM;
mr->rangesize++;
*flags |= IPT_SAME_OPT_TO;
break;
case '2':
if (*flags & IPT_SAME_OPT_NODST)
xtables_error(PARAMETER_PROBLEM,
"Can't specify --nodst twice");
mr->info |= IPT_SAME_NODST;
*flags |= IPT_SAME_OPT_NODST;
break;
case '3':
*flags |= IPT_SAME_OPT_RANDOM;
for (count=0; count < mr->rangesize; count++)
mr->range[count].flags |= IP_NAT_RANGE_PROTO_RANDOM;
break;
default:
return 0;
}
return 1;
}
static void SAME_check(unsigned int flags)
{
if (!(flags & IPT_SAME_OPT_TO))
xtables_error(PARAMETER_PROBLEM,
"SAME needs --to");
}
static void SAME_print(const void *ip, const struct xt_entry_target *target,
int numeric)
{
unsigned int count;
const struct ipt_same_info *mr = (const void *)target->data;
int random_selection = 0;
printf("same:");
for (count = 0; count < mr->rangesize; count++) {
const struct nf_nat_range *r = &mr->range[count];
struct in_addr a;
a.s_addr = r->min_ip;
printf("%s", xtables_ipaddr_to_numeric(&a));
a.s_addr = r->max_ip;
if (r->min_ip == r->max_ip)
printf(" ");
else
printf("-%s ", xtables_ipaddr_to_numeric(&a));
if (r->flags & IP_NAT_RANGE_PROTO_RANDOM)
random_selection = 1;
}
if (mr->info & IPT_SAME_NODST)
printf("nodst ");
if (random_selection)
printf("random ");
}
static void SAME_save(const void *ip, const struct xt_entry_target *target)
{
unsigned int count;
const struct ipt_same_info *mr = (const void *)target->data;
int random_selection = 0;
for (count = 0; count < mr->rangesize; count++) {
const struct nf_nat_range *r = &mr->range[count];
struct in_addr a;
a.s_addr = r->min_ip;
printf("--to %s", xtables_ipaddr_to_numeric(&a));
a.s_addr = r->max_ip;
if (r->min_ip == r->max_ip)
printf(" ");
else
printf("-%s ", xtables_ipaddr_to_numeric(&a));
if (r->flags & IP_NAT_RANGE_PROTO_RANDOM)
random_selection = 1;
}
if (mr->info & IPT_SAME_NODST)
printf("--nodst ");
if (random_selection)
printf("--random ");
}
static struct xtables_target same_tg_reg = {
.name = "SAME",
.version = XTABLES_VERSION,
.family = NFPROTO_IPV4,
.size = XT_ALIGN(sizeof(struct ipt_same_info)),
.userspacesize = XT_ALIGN(sizeof(struct ipt_same_info)),
.help = SAME_help,
.init = SAME_init,
.parse = SAME_parse,
.final_check = SAME_check,
.print = SAME_print,
.save = SAME_save,
.extra_opts = SAME_opts,
};
void _init(void)
{
xtables_register_target(&same_tg_reg);
}
|
