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
|
/* Shared library add-on to iptables to add ESP support. */
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <errno.h>
#include <limits.h>
#include <xtables.h>
#include <linux/netfilter/xt_esp.h>
static void esp_help(void)
{
printf(
"esp match options:\n"
"[!] --espspi spi[:spi]\n"
" match spi (range)\n");
}
static const struct option esp_opts[] = {
{ "espspi", 1, NULL, '1' },
{ .name = NULL }
};
static u_int32_t
parse_esp_spi(const char *spistr)
{
unsigned long int spi;
char* ep;
spi = strtoul(spistr,&ep,0) ;
if ( spistr == ep ) {
xtables_error(PARAMETER_PROBLEM,
"ESP no valid digits in spi `%s'", spistr);
}
if ( spi == ULONG_MAX && errno == ERANGE ) {
xtables_error(PARAMETER_PROBLEM,
"spi `%s' specified too big: would overflow", spistr);
}
if ( *spistr != '\0' && *ep != '\0' ) {
xtables_error(PARAMETER_PROBLEM,
"ESP error parsing spi `%s'", spistr);
}
return spi;
}
static void
parse_esp_spis(const char *spistring, u_int32_t *spis)
{
char *buffer;
char *cp;
buffer = strdup(spistring);
if ((cp = strchr(buffer, ':')) == NULL)
spis[0] = spis[1] = parse_esp_spi(buffer);
else {
*cp = '\0';
cp++;
spis[0] = buffer[0] ? parse_esp_spi(buffer) : 0;
spis[1] = cp[0] ? parse_esp_spi(cp) : 0xFFFFFFFF;
if (spis[0] > spis[1])
xtables_error(PARAMETER_PROBLEM,
"Invalid ESP spi range: %s", spistring);
}
free(buffer);
}
static void esp_init(struct xt_entry_match *m)
{
struct xt_esp *espinfo = (struct xt_esp *)m->data;
espinfo->spis[1] = 0xFFFFFFFF;
}
#define ESP_SPI 0x01
static int
esp_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_match **match)
{
struct xt_esp *espinfo = (struct xt_esp *)(*match)->data;
switch (c) {
case '1':
if (*flags & ESP_SPI)
xtables_error(PARAMETER_PROBLEM,
"Only one `--espspi' allowed");
xtables_check_inverse(optarg, &invert, &optind, 0, argv);
parse_esp_spis(optarg, espinfo->spis);
if (invert)
espinfo->invflags |= XT_ESP_INV_SPI;
*flags |= ESP_SPI;
break;
default:
return 0;
}
return 1;
}
static void
print_spis(const char *name, u_int32_t min, u_int32_t max,
int invert)
{
const char *inv = invert ? "!" : "";
if (min != 0 || max != 0xFFFFFFFF || invert) {
if (min == max)
printf("%s:%s%u ", name, inv, min);
else
printf("%ss:%s%u:%u ", name, inv, min, max);
}
}
static void
esp_print(const void *ip, const struct xt_entry_match *match, int numeric)
{
const struct xt_esp *esp = (struct xt_esp *)match->data;
printf("esp ");
print_spis("spi", esp->spis[0], esp->spis[1],
esp->invflags & XT_ESP_INV_SPI);
if (esp->invflags & ~XT_ESP_INV_MASK)
printf("Unknown invflags: 0x%X ",
esp->invflags & ~XT_ESP_INV_MASK);
}
static void esp_save(const void *ip, const struct xt_entry_match *match)
{
const struct xt_esp *espinfo = (struct xt_esp *)match->data;
if (!(espinfo->spis[0] == 0
&& espinfo->spis[1] == 0xFFFFFFFF)) {
printf("%s--espspi ",
(espinfo->invflags & XT_ESP_INV_SPI) ? "! " : "");
if (espinfo->spis[0]
!= espinfo->spis[1])
printf("%u:%u ",
espinfo->spis[0],
espinfo->spis[1]);
else
printf("%u ",
espinfo->spis[0]);
}
}
static struct xtables_match esp_match = {
.family = NFPROTO_UNSPEC,
.name = "esp",
.version = XTABLES_VERSION,
.size = XT_ALIGN(sizeof(struct xt_esp)),
.userspacesize = XT_ALIGN(sizeof(struct xt_esp)),
.help = esp_help,
.init = esp_init,
.parse = esp_parse,
.print = esp_print,
.save = esp_save,
.extra_opts = esp_opts,
};
void
_init(void)
{
xtables_register_match(&esp_match);
}
|
