Add RATEEST target extension

Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 240 insertions, 0 deletions

diff --git a/extensions/libxt_RATEEST.c b/extensions/libxt_RATEEST.c
new file mode 100644
index 00000000..8445cdf2
--- /dev/null
+++ b/extensions/libxt_RATEEST.c
@@ -0,0 +1,240 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <getopt.h>
+#include <math.h>
+
+#include <xtables.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_RATEEST.h>
+
+/* hack to pass raw values to final_check */
+static struct xt_rateest_target_info *RATEEST_info;
+static unsigned int interval;
+static unsigned int ewma_log;
+
+static void
+RATEEST_help(void)
+{
+	printf(
+"RATEST target v%s 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"
+"\n",
+	       IPTABLES_VERSION);
+}
+
+enum RATEEST_options {
+	RATEEST_OPT_NAME,
+	RATEEST_OPT_INTERVAL,
+	RATEEST_OPT_EWMALOG,
+};
+
+static const struct option RATEEST_opts[] = {
+	{ "rateest-name",	1, NULL, RATEEST_OPT_NAME },
+	{ "rateest-interval",	1, NULL, RATEEST_OPT_INTERVAL },
+	{ "rateest-ewmalog",	1, NULL, RATEEST_OPT_EWMALOG },
+	{ },
+};
+
+/* 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_init(struct xt_entry_target *target)
+{
+	interval = 0;
+	ewma_log = 0;
+}
+
+static int
+RATEEST_parse(int c, char **argv, int invert, unsigned int *flags,
+	      const void *entry, struct xt_entry_target **target)
+{
+	struct xt_rateest_target_info *info = (void *)(*target)->data;
+
+	RATEEST_info = info;
+
+	switch (c) {
+	case RATEEST_OPT_NAME:
+		if (*flags & (1 << c))
+			exit_error(PARAMETER_PROBLEM,
+				   "RATEEST: can't specify --rateest-name twice");
+		*flags |= 1 << c;
+
+		strncpy(info->name, optarg, sizeof(info->name) - 1);
+		break;
+
+	case RATEEST_OPT_INTERVAL:
+		if (*flags & (1 << c))
+			exit_error(PARAMETER_PROBLEM,
+				   "RATEEST: can't specify --rateest-interval twice");
+		*flags |= 1 << c;
+
+		if (RATEEST_get_time(&interval, optarg) < 0)
+			exit_error(PARAMETER_PROBLEM,
+				   "RATEEST: bad interval value `%s'", optarg);
+
+		break;
+
+	case RATEEST_OPT_EWMALOG:
+		if (*flags & (1 << c))
+			exit_error(PARAMETER_PROBLEM,
+				   "RATEEST: can't specify --rateest-ewmalog twice");
+		*flags |= 1 << c;
+
+		if (RATEEST_get_time(&ewma_log, optarg) < 0)
+			exit_error(PARAMETER_PROBLEM,
+				   "RATEEST: bad ewmalog value `%s'", optarg);
+
+		break;
+
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static void
+RATEEST_final_check(unsigned int flags)
+{
+	struct xt_rateest_target_info *info = RATEEST_info;
+
+	if (!(flags & (1 << RATEEST_OPT_NAME)))
+		exit_error(PARAMETER_PROBLEM, "RATEEST: no name specified");
+	if (!(flags & (1 << RATEEST_OPT_INTERVAL)))
+		exit_error(PARAMETER_PROBLEM, "RATEEST: no interval specified");
+	if (!(flags & (1 << RATEEST_OPT_EWMALOG)))
+		exit_error(PARAMETER_PROBLEM, "RATEEST: no ewmalog specified");
+
+	for (info->interval = 0; info->interval <= 5; info->interval++) {
+		if (interval <= (1 << info->interval) * (TIME_UNITS_PER_SEC / 4))
+			break;
+	}
+
+	if (info->interval > 5)
+		exit_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 (interval / (-log(w)) > ewma_log)
+			break;
+	}
+	info->ewma_log--;
+
+	if (info->ewma_log == 0 || info->ewma_log >= 31)
+		exit_error(PARAMETER_PROBLEM,
+			   "RATEEST: ewmalog value is out of range");
+}
+
+static void
+__RATEEST_print(const struct xt_entry_target *target, const char *prefix)
+{
+	struct xt_rateest_target_info *info = (void *)target->data;
+	unsigned int interval;
+	unsigned int ewma_log;
+
+	interval = (TIME_UNITS_PER_SEC << (info->interval + 2)) / 4;
+	ewma_log = interval * (1 << (info->ewma_log));
+
+	printf("%sname %s ", prefix, info->name);
+	printf("%sinterval ", prefix);
+	RATEEST_print_time(interval);
+	printf("%sewmalog ", prefix);
+	RATEEST_print_time(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_target4 = {
+	.family		= AF_INET,
+	.name		= "RATEEST",
+	.version	= IPTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_rateest_target_info)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_rateest_target_info)),
+	.help		= RATEEST_help,
+	.init		= RATEEST_init,
+	.parse		= RATEEST_parse,
+	.final_check	= RATEEST_final_check,
+	.print		= RATEEST_print,
+	.save		= RATEEST_save,
+	.extra_opts	= RATEEST_opts,
+};
+
+static struct xtables_target rateest_target6 = {
+	.family		= AF_INET6,
+	.name		= "RATEEST",
+	.version	= IPTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_rateest_target_info)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_rateest_target_info)),
+	.help		= RATEEST_help,
+	.init		= RATEEST_init,
+	.parse		= RATEEST_parse,
+	.final_check	= RATEEST_final_check,
+	.print		= RATEEST_print,
+	.save		= RATEEST_save,
+	.extra_opts	= RATEEST_opts,
+};
+
+void _init(void)
+{
+	xtables_register_target(&rateest_target4);
+	xtables_register_target(&rateest_target6);
+}