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
218
219
220
221
222
223
224
225
226
227
|
/* Shared library add-on to ip6tables to add AH support. */
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <errno.h>
#include <ip6tables.h>
#include <linux/netfilter_ipv6/ip6t_ah.h>
/* Function which prints out usage message. */
static void
help(void)
{
printf(
"AH v%s options:\n"
" --ahspi [!] spi[:spi] match spi (range)\n"
" --ahlen [!] length total length of this header\n"
" --ahres check the reserved filed, too\n",
IPTABLES_VERSION);
}
static struct option opts[] = {
{ .name = "ahspi", .has_arg = 1, .flag = 0, .val = '1' },
{ .name = "ahlen", .has_arg = 1, .flag = 0, .val = '2' },
{ .name = "ahres", .has_arg = 0, .flag = 0, .val = '3' },
{ .name = 0 }
};
static u_int32_t
parse_ah_spi(const char *spistr, const char *typestr)
{
unsigned long int spi;
char* ep;
spi = strtoul(spistr, &ep, 0);
if ( spistr == ep )
exit_error(PARAMETER_PROBLEM,
"AH no valid digits in %s `%s'", typestr, spistr);
if ( spi == ULONG_MAX && errno == ERANGE )
exit_error(PARAMETER_PROBLEM,
"%s `%s' specified too big: would overflow",
typestr, spistr);
if ( *spistr != '\0' && *ep != '\0' )
exit_error(PARAMETER_PROBLEM,
"AH error parsing %s `%s'", typestr, 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, "spi");
else {
*cp = '\0';
cp++;
spis[0] = buffer[0] ? parse_ah_spi(buffer, "spi") : 0;
spis[1] = cp[0] ? parse_ah_spi(cp, "spi") : 0xFFFFFFFF;
}
free(buffer);
}
/* Initialize the match. */
static void
init(struct ip6t_entry_match *m, unsigned int *nfcache)
{
struct ip6t_ah *ahinfo = (struct ip6t_ah *)m->data;
ahinfo->spis[1] = 0xFFFFFFFF;
ahinfo->hdrlen = 0;
ahinfo->hdrres = 0;
}
/* 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 struct ip6t_entry *entry,
unsigned int *nfcache,
struct ip6t_entry_match **match)
{
struct ip6t_ah *ahinfo = (struct ip6t_ah *)(*match)->data;
switch (c) {
case '1':
if (*flags & IP6T_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 |= IP6T_AH_INV_SPI;
*flags |= IP6T_AH_SPI;
break;
case '2':
if (*flags & IP6T_AH_LEN)
exit_error(PARAMETER_PROBLEM,
"Only one `--ahlen' allowed");
check_inverse(optarg, &invert, &optind, 0);
ahinfo->hdrlen = parse_ah_spi(argv[optind-1], "length");
if (invert)
ahinfo->invflags |= IP6T_AH_INV_LEN;
*flags |= IP6T_AH_LEN;
break;
case '3':
if (*flags & IP6T_AH_RES)
exit_error(PARAMETER_PROBLEM,
"Only one `--ahres' allowed");
ahinfo->hdrres = 1;
*flags |= IP6T_AH_RES;
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) {
if (min == max)
printf("%s:%s%u ", name, inv, min);
else
printf("%ss:%s%u:%u ", name, inv, min, max);
}
}
static void
print_len(const char *name, u_int32_t len, int invert)
{
const char *inv = invert ? "!" : "";
if (len != 0 || invert)
printf("%s:%s%u ", name, inv, len);
}
/* Prints out the union ip6t_matchinfo. */
static void
print(const struct ip6t_ip6 *ip,
const struct ip6t_entry_match *match, int numeric)
{
const struct ip6t_ah *ah = (struct ip6t_ah *)match->data;
printf("ah ");
print_spis("spi", ah->spis[0], ah->spis[1],
ah->invflags & IP6T_AH_INV_SPI);
print_len("length", ah->hdrlen,
ah->invflags & IP6T_AH_INV_LEN);
if (ah->hdrres)
printf("reserved ");
if (ah->invflags & ~IP6T_AH_INV_MASK)
printf("Unknown invflags: 0x%X ",
ah->invflags & ~IP6T_AH_INV_MASK);
}
/* Saves the union ip6t_matchinfo in parsable form to stdout. */
static void save(const struct ip6t_ip6 *ip, const struct ip6t_entry_match *match)
{
const struct ip6t_ah *ahinfo = (struct ip6t_ah *)match->data;
if (!(ahinfo->spis[0] == 0
&& ahinfo->spis[1] == 0xFFFFFFFF)) {
printf("--ahspi %s",
(ahinfo->invflags & IP6T_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]);
}
if (ahinfo->hdrlen != 0 || (ahinfo->invflags & IP6T_AH_INV_LEN) ) {
printf("--ahlen %s%u ",
(ahinfo->invflags & IP6T_AH_INV_LEN) ? "! " : "",
ahinfo->hdrlen);
}
if (ahinfo->hdrres != 0 )
printf("--ahres ");
}
static
struct ip6tables_match ah = {
.name = "ah",
.version = IPTABLES_VERSION,
.size = IP6T_ALIGN(sizeof(struct ip6t_ah)),
.userspacesize = IP6T_ALIGN(sizeof(struct ip6t_ah)),
.help = &help,
.init = &init,
.parse = &parse,
.final_check = &final_check,
.print = &print,
.save = &save,
.extra_opts = opts
};
void
_init(void)
{
register_match6(&ah);
}
|
