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
|
/* Shared library add-on to iptables to add AH support. */
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <errno.h>
#include <iptables.h>
#include <linux/netfilter_ipv4/ipt_ah.h>
/* Function which prints out usage message. */
static void
help(void)
{
printf(
"AH v%s options:\n"
" --ahspi [!] spi[:spi]\n"
" match spi (range)\n",
IPTABLES_VERSION);
}
static const struct option opts[] = {
{ "ahspi", 1, 0, '1' },
{0}
};
static u_int32_t
parse_ah_spi(const char *spistr)
{
unsigned long int spi;
char* ep;
spi = strtoul(spistr,&ep,0) ;
if ( spistr == ep ) {
exit_error(PARAMETER_PROBLEM,
"AH no valid digits in spi `%s'", spistr);
}
if ( spi == ULONG_MAX && errno == ERANGE ) {
exit_error(PARAMETER_PROBLEM,
"spi `%s' specified too big: would overflow", spistr);
}
if ( *spistr != '\0' && *ep != '\0' ) {
exit_error(PARAMETER_PROBLEM,
"AH error parsing spi `%s'", spistr);
}
return (u_int32_t) spi;
}
static void
parse_ah_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_ah_spi(buffer);
else {
*cp = '\0';
cp++;
spis[0] = buffer[0] ? parse_ah_spi(buffer) : 0;
spis[1] = cp[0] ? parse_ah_spi(cp) : 0xFFFFFFFF;
}
free(buffer);
}
/* Initialize the match. */
static void
init(struct xt_entry_match *m)
{
struct ipt_ah *ahinfo = (struct ipt_ah *)m->data;
ahinfo->spis[1] = 0xFFFFFFFF;
}
#define AH_SPI 0x01
/* Function which parses command options; returns true if it
ate an option */
static int
parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry,
struct xt_entry_match **match)
{
struct ipt_ah *ahinfo = (struct ipt_ah *)(*match)->data;
switch (c) {
case '1':
if (*flags & AH_SPI)
exit_error(PARAMETER_PROBLEM,
"Only one `--ahspi' allowed");
check_inverse(optarg, &invert, &optind, 0);
parse_ah_spis(argv[optind-1], ahinfo->spis);
if (invert)
ahinfo->invflags |= IPT_AH_INV_SPI;
*flags |= AH_SPI;
break;
default:
return 0;
}
return 1;
}
/* Final check; we don't care. */
static void
final_check(unsigned int flags)
{
}
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) {
printf("%s", name);
if (min == max) {
printf(":%s", inv);
printf("%u", min);
} else {
printf("s:%s", inv);
printf("%u",min);
printf(":");
printf("%u",max);
}
printf(" ");
}
}
/* Prints out the union ipt_matchinfo. */
static void
print(const void *ip,
const struct xt_entry_match *match, int numeric)
{
const struct ipt_ah *ah = (struct ipt_ah *)match->data;
printf("ah ");
print_spis("spi", ah->spis[0], ah->spis[1],
ah->invflags & IPT_AH_INV_SPI);
if (ah->invflags & ~IPT_AH_INV_MASK)
printf("Unknown invflags: 0x%X ",
ah->invflags & ~IPT_AH_INV_MASK);
}
/* Saves the union ipt_matchinfo in parsable form to stdout. */
static void save(const void *ip, const struct xt_entry_match *match)
{
const struct ipt_ah *ahinfo = (struct ipt_ah *)match->data;
if (!(ahinfo->spis[0] == 0
&& ahinfo->spis[1] == 0xFFFFFFFF)) {
printf("--ahspi %s",
(ahinfo->invflags & IPT_AH_INV_SPI) ? "! " : "");
if (ahinfo->spis[0]
!= ahinfo->spis[1])
printf("%u:%u ",
ahinfo->spis[0],
ahinfo->spis[1]);
else
printf("%u ",
ahinfo->spis[0]);
}
}
static struct iptables_match ah = {
.name = "ah",
.version = IPTABLES_VERSION,
.size = IPT_ALIGN(sizeof(struct ipt_ah)),
.userspacesize = IPT_ALIGN(sizeof(struct ipt_ah)),
.help = &help,
.init = &init,
.parse = &parse,
.final_check = &final_check,
.print = &print,
.save = &save,
.extra_opts = opts
};
void
_init(void)
{
register_match(&ah);
}
|
