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
|
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <xtables.h>
#include <linux/netfilter/xt_recent.h>
enum {
O_SET = 0,
O_RCHECK,
O_UPDATE,
O_REMOVE,
O_SECONDS,
O_REAP,
O_HITCOUNT,
O_RTTL,
O_NAME,
O_RSOURCE,
O_RDEST,
F_SET = 1 << O_SET,
F_RCHECK = 1 << O_RCHECK,
F_UPDATE = 1 << O_UPDATE,
F_REMOVE = 1 << O_REMOVE,
F_SECONDS = 1 << O_SECONDS,
F_ANY_OP = F_SET | F_RCHECK | F_UPDATE | F_REMOVE,
};
#define s struct xt_recent_mtinfo
static const struct xt_option_entry recent_opts[] = {
{.name = "set", .id = O_SET, .type = XTTYPE_NONE,
.excl = F_ANY_OP, .flags = XTOPT_INVERT},
{.name = "rcheck", .id = O_RCHECK, .type = XTTYPE_NONE,
.excl = F_ANY_OP, .flags = XTOPT_INVERT},
{.name = "update", .id = O_UPDATE, .type = XTTYPE_NONE,
.excl = F_ANY_OP, .flags = XTOPT_INVERT},
{.name = "remove", .id = O_REMOVE, .type = XTTYPE_NONE,
.excl = F_ANY_OP, .flags = XTOPT_INVERT},
{.name = "seconds", .id = O_SECONDS, .type = XTTYPE_UINT32,
.flags = XTOPT_PUT, XTOPT_POINTER(s, seconds), .min = 1},
{.name = "reap", .id = O_REAP, .type = XTTYPE_NONE,
.also = F_SECONDS },
{.name = "hitcount", .id = O_HITCOUNT, .type = XTTYPE_UINT32,
.flags = XTOPT_PUT, XTOPT_POINTER(s, hit_count)},
{.name = "rttl", .id = O_RTTL, .type = XTTYPE_NONE,
.excl = F_SET | F_REMOVE},
{.name = "name", .id = O_NAME, .type = XTTYPE_STRING,
.flags = XTOPT_PUT, XTOPT_POINTER(s, name)},
{.name = "rsource", .id = O_RSOURCE, .type = XTTYPE_NONE},
{.name = "rdest", .id = O_RDEST, .type = XTTYPE_NONE},
XTOPT_TABLEEND,
};
#undef s
static void recent_help(void)
{
printf(
"recent match options:\n"
"[!] --set Add source address to list, always matches.\n"
"[!] --rcheck Match if source address in list.\n"
"[!] --update Match if source address in list, also update last-seen time.\n"
"[!] --remove Match if source address in list, also removes that address from list.\n"
" --seconds seconds For check and update commands above.\n"
" Specifies that the match will only occur if source address last seen within\n"
" the last 'seconds' seconds.\n"
" --reap Purge entries older then 'seconds'.\n"
" Can only be used in conjunction with the seconds option.\n"
" --hitcount hits For check and update commands above.\n"
" Specifies that the match will only occur if source address seen hits times.\n"
" May be used in conjunction with the seconds option.\n"
" --rttl For check and update commands above.\n"
" Specifies that the match will only occur if the source address and the TTL\n"
" match between this packet and the one which was set.\n"
" Useful if you have problems with people spoofing their source address in order\n"
" to DoS you via this module.\n"
" --name name Name of the recent list to be used. DEFAULT used if none given.\n"
" --rsource Match/Save the source address of each packet in the recent list table (default).\n"
" --rdest Match/Save the destination address of each packet in the recent list table.\n"
"xt_recent by: Stephen Frost <sfrost@snowman.net>. http://snowman.net/projects/ipt_recent/\n");
}
static void recent_init(struct xt_entry_match *match)
{
struct xt_recent_mtinfo *info = (void *)(match)->data;
strncpy(info->name,"DEFAULT", XT_RECENT_NAME_LEN);
/* even though XT_RECENT_NAME_LEN is currently defined as 200,
* better be safe, than sorry */
info->name[XT_RECENT_NAME_LEN-1] = '\0';
info->side = XT_RECENT_SOURCE;
}
static void recent_parse(struct xt_option_call *cb)
{
struct xt_recent_mtinfo *info = cb->data;
xtables_option_parse(cb);
switch (cb->entry->id) {
case O_SET:
info->check_set |= XT_RECENT_SET;
if (cb->invert)
info->invert = true;
break;
case O_RCHECK:
info->check_set |= XT_RECENT_CHECK;
if (cb->invert)
info->invert = true;
break;
case O_UPDATE:
info->check_set |= XT_RECENT_UPDATE;
if (cb->invert)
info->invert = true;
break;
case O_REMOVE:
info->check_set |= XT_RECENT_REMOVE;
if (cb->invert)
info->invert = true;
break;
case O_RTTL:
info->check_set |= XT_RECENT_TTL;
break;
case O_RSOURCE:
info->side = XT_RECENT_SOURCE;
break;
case O_RDEST:
info->side = XT_RECENT_DEST;
break;
case O_REAP:
info->check_set |= XT_RECENT_REAP;
break;
}
}
static void recent_check(struct xt_fcheck_call *cb)
{
if (!(cb->xflags & F_ANY_OP))
xtables_error(PARAMETER_PROBLEM,
"recent: you must specify one of `--set', `--rcheck' "
"`--update' or `--remove'");
}
static void recent_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct xt_recent_mtinfo *info = (const void *)match->data;
if (info->invert)
printf(" !");
printf(" recent:");
if (info->check_set & XT_RECENT_SET)
printf(" SET");
if (info->check_set & XT_RECENT_CHECK)
printf(" CHECK");
if (info->check_set & XT_RECENT_UPDATE)
printf(" UPDATE");
if (info->check_set & XT_RECENT_REMOVE)
printf(" REMOVE");
if(info->seconds) printf(" seconds: %d", info->seconds);
if (info->check_set & XT_RECENT_REAP)
printf(" reap");
if(info->hit_count) printf(" hit_count: %d", info->hit_count);
if (info->check_set & XT_RECENT_TTL)
printf(" TTL-Match");
if(info->name) printf(" name: %s", info->name);
if (info->side == XT_RECENT_SOURCE)
printf(" side: source");
if (info->side == XT_RECENT_DEST)
printf(" side: dest");
}
static void recent_save(const void *ip, const struct xt_entry_match *match)
{
const struct xt_recent_mtinfo *info = (const void *)match->data;
if (info->invert)
printf(" !");
if (info->check_set & XT_RECENT_SET)
printf(" --set");
if (info->check_set & XT_RECENT_CHECK)
printf(" --rcheck");
if (info->check_set & XT_RECENT_UPDATE)
printf(" --update");
if (info->check_set & XT_RECENT_REMOVE)
printf(" --remove");
if(info->seconds) printf(" --seconds %d", info->seconds);
if (info->check_set & XT_RECENT_REAP)
printf(" --reap");
if(info->hit_count) printf(" --hitcount %d", info->hit_count);
if (info->check_set & XT_RECENT_TTL)
printf(" --rttl");
if(info->name) printf(" --name %s",info->name);
if (info->side == XT_RECENT_SOURCE)
printf(" --rsource");
if (info->side == XT_RECENT_DEST)
printf(" --rdest");
}
static struct xtables_match recent_mt_reg = {
.name = "recent",
.version = XTABLES_VERSION,
.family = NFPROTO_UNSPEC,
.size = XT_ALIGN(sizeof(struct xt_recent_mtinfo)),
.userspacesize = XT_ALIGN(sizeof(struct xt_recent_mtinfo)),
.help = recent_help,
.init = recent_init,
.x6_parse = recent_parse,
.x6_fcheck = recent_check,
.print = recent_print,
.save = recent_save,
.x6_options = recent_opts,
};
void _init(void)
{
xtables_register_match(&recent_mt_reg);
}
|
