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#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)
{
struct xt_recent_mtinfo *info = cb->data;
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);
}
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