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
|
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <getopt.h>
#include "../include/ebtables_u.h"
#include <linux/netfilter_bridge/ebt_redirect.h>
extern char *standard_targets[NUM_STANDARD_TARGETS];
#define REDIRECT_TARGET '1'
static struct option opts[] =
{
{ "redirect-target", required_argument, 0, REDIRECT_TARGET },
{ 0 }
};
static void print_help()
{
printf(
"redirect option:\n"
" --redirect-target target : ACCEPT, DROP, RETURN or CONTINUE\n");
}
static void init(struct ebt_entry_target *target)
{
struct ebt_redirect_info *redirectinfo =
(struct ebt_redirect_info *)target->data;
redirectinfo->target = EBT_ACCEPT;
return;
}
#define OPT_REDIRECT_TARGET 0x01
static int parse(int c, char **argv, int argc,
const struct ebt_u_entry *entry, unsigned int *flags,
struct ebt_entry_target **target)
{
int i;
struct ebt_redirect_info *redirectinfo =
(struct ebt_redirect_info *)(*target)->data;
switch (c) {
case REDIRECT_TARGET:
check_option(flags, OPT_REDIRECT_TARGET);
for (i = 0; i < NUM_STANDARD_TARGETS; i++)
if (!strcmp(optarg, standard_targets[i])) {
redirectinfo->target = -i - 1;
break;
}
if (i == NUM_STANDARD_TARGETS)
print_error("Illegal --redirect-target target");
break;
default:
return 0;
}
return 1;
}
static void final_check(const struct ebt_u_entry *entry,
const struct ebt_entry_target *target, const char *name,
unsigned int hook_mask, unsigned int time)
{
struct ebt_redirect_info *redirectinfo =
(struct ebt_redirect_info *)target->data;
if ((hook_mask & (1 << NF_BR_NUMHOOKS)) &&
redirectinfo->target == EBT_RETURN)
print_error("--redirect-target RETURN not allowed on base chain");
hook_mask &= ~(1 << NF_BR_NUMHOOKS);
if ( ((hook_mask & ~(1 << NF_BR_PRE_ROUTING)) || strcmp(name, "nat")) &&
((hook_mask & ~(1 << NF_BR_BROUTING)) || strcmp(name, "broute")) )
print_error("Wrong chain for redirect");
}
static void print(const struct ebt_u_entry *entry,
const struct ebt_entry_target *target)
{
struct ebt_redirect_info *redirectinfo =
(struct ebt_redirect_info *)target->data;
if (redirectinfo->target == EBT_ACCEPT)
return;
printf(" --redirect-target %s",
standard_targets[-redirectinfo->target - 1]);
}
static int compare(const struct ebt_entry_target *t1,
const struct ebt_entry_target *t2)
{
struct ebt_redirect_info *redirectinfo1 =
(struct ebt_redirect_info *)t1->data;
struct ebt_redirect_info *redirectinfo2 =
(struct ebt_redirect_info *)t2->data;
return redirectinfo1->target == redirectinfo2->target;
}
static struct ebt_u_target redirect_target =
{
EBT_REDIRECT_TARGET,
sizeof(struct ebt_redirect_info),
print_help,
init,
parse,
final_check,
print,
compare,
opts,
};
static void _init(void) __attribute__ ((constructor));
static void _init(void)
{
register_target(&redirect_target);
}
|