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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <xtables.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_RATEEST.h>
struct rateest_tg_udata {
unsigned int interval;
unsigned int ewma_log;
};
static void
RATEEST_help(void)
{
printf(
"RATEEST target options:\n"
" --rateest-name name Rate estimator name\n"
" --rateest-interval sec Rate measurement interval in seconds\n"
" --rateest-ewmalog value Rate measurement averaging time constant\n");
}
enum {
O_NAME = 0,
O_INTERVAL,
O_EWMALOG,
};
#define s struct xt_rateest_target_info
static const struct xt_option_entry RATEEST_opts[] = {
{.name = "rateest-name", .id = O_NAME, .type = XTTYPE_STRING,
.flags = XTOPT_MAND | XTOPT_PUT, XTOPT_POINTER(s, name)},
{.name = "rateest-interval", .id = O_INTERVAL, .type = XTTYPE_STRING,
.flags = XTOPT_MAND},
{.name = "rateest-ewmalog", .id = O_EWMALOG, .type = XTTYPE_STRING,
.flags = XTOPT_MAND},
XTOPT_TABLEEND,
};
#undef s
/* Copied from iproute */
#define TIME_UNITS_PER_SEC 1000000
static int
RATEEST_get_time(unsigned int *time, const char *str)
{
double t;
char *p;
t = strtod(str, &p);
if (p == str)
return -1;
if (*p) {
if (strcasecmp(p, "s") == 0 || strcasecmp(p, "sec")==0 ||
strcasecmp(p, "secs")==0)
t *= TIME_UNITS_PER_SEC;
else if (strcasecmp(p, "ms") == 0 || strcasecmp(p, "msec")==0 ||
strcasecmp(p, "msecs") == 0)
t *= TIME_UNITS_PER_SEC/1000;
else if (strcasecmp(p, "us") == 0 || strcasecmp(p, "usec")==0 ||
strcasecmp(p, "usecs") == 0)
t *= TIME_UNITS_PER_SEC/1000000;
else
return -1;
}
*time = t;
return 0;
}
static void
RATEEST_print_time(unsigned int time)
{
double tmp = time;
if (tmp >= TIME_UNITS_PER_SEC)
printf(" %.1fs", tmp / TIME_UNITS_PER_SEC);
else if (tmp >= TIME_UNITS_PER_SEC/1000)
printf(" %.1fms", tmp / (TIME_UNITS_PER_SEC / 1000));
else
printf(" %uus", time);
}
static void RATEEST_parse(struct xt_option_call *cb)
{
struct rateest_tg_udata *udata = cb->udata;
xtables_option_parse(cb);
switch (cb->entry->id) {
case O_INTERVAL:
if (RATEEST_get_time(&udata->interval, cb->arg) < 0)
xtables_error(PARAMETER_PROBLEM,
"RATEEST: bad interval value \"%s\"",
cb->arg);
break;
case O_EWMALOG:
if (RATEEST_get_time(&udata->ewma_log, cb->arg) < 0)
xtables_error(PARAMETER_PROBLEM,
"RATEEST: bad ewmalog value \"%s\"",
cb->arg);
break;
}
}
static void RATEEST_final_check(struct xt_fcheck_call *cb)
{
struct xt_rateest_target_info *info = cb->data;
struct rateest_tg_udata *udata = cb->udata;
for (info->interval = 0; info->interval <= 5; info->interval++) {
if (udata->interval <= (1 << info->interval) * (TIME_UNITS_PER_SEC / 4))
break;
}
if (info->interval > 5)
xtables_error(PARAMETER_PROBLEM,
"RATEEST: interval value is too large");
info->interval -= 2;
for (info->ewma_log = 1; info->ewma_log < 32; info->ewma_log++) {
double w = 1.0 - 1.0 / (1 << info->ewma_log);
if (udata->interval / (-log(w)) > udata->ewma_log)
break;
}
info->ewma_log--;
if (info->ewma_log == 0 || info->ewma_log >= 31)
xtables_error(PARAMETER_PROBLEM,
"RATEEST: ewmalog value is out of range");
}
static void
__RATEEST_print(const struct xt_entry_target *target, const char *prefix)
{
const struct xt_rateest_target_info *info = (const void *)target->data;
unsigned int local_interval;
unsigned int local_ewma_log;
local_interval = (TIME_UNITS_PER_SEC << (info->interval + 2)) / 4;
local_ewma_log = local_interval * (1 << (info->ewma_log));
printf(" %sname %s", prefix, info->name);
printf(" %sinterval", prefix);
RATEEST_print_time(local_interval);
printf(" %sewmalog", prefix);
RATEEST_print_time(local_ewma_log);
}
static void
RATEEST_print(const void *ip, const struct xt_entry_target *target,
int numeric)
{
__RATEEST_print(target, "");
}
static void
RATEEST_save(const void *ip, const struct xt_entry_target *target)
{
__RATEEST_print(target, "--rateest-");
}
static struct xtables_target rateest_tg_reg = {
.family = NFPROTO_UNSPEC,
.name = "RATEEST",
.version = XTABLES_VERSION,
.size = XT_ALIGN(sizeof(struct xt_rateest_target_info)),
.userspacesize = offsetof(struct xt_rateest_target_info, est),
.help = RATEEST_help,
.x6_parse = RATEEST_parse,
.x6_fcheck = RATEEST_final_check,
.print = RATEEST_print,
.save = RATEEST_save,
.x6_options = RATEEST_opts,
.udata_size = sizeof(struct rateest_tg_udata),
};
void _init(void)
{
xtables_register_target(&rateest_tg_reg);
}
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