diff --git a/extensions/.condition-test b/extensions/.condition-test
new file mode 100755
index 0000000..20f3bc7
--- /dev/null
+++ b/extensions/.condition-test
@@ -0,0 +1,3 @@
+#!/bin/sh
+# True if condition is applied.
+[ -f $KERNEL_DIR/include/linux/netfilter_ipv4/ipt_condition.h ] && echo condition
diff --git a/extensions/libipt_condition.c b/extensions/libipt_condition.c
new file mode 100644
index 0000000..351c1aa
--- /dev/null
+++ b/extensions/libipt_condition.c
@@ -0,0 +1,96 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <iptables.h>
+
+#include<linux/netfilter_ipv4/ip_tables.h>
+#include<linux/netfilter_ipv4/ipt_condition.h>
+
+
+static void help(void)
+{
+  printf("condition match v%s options:\n"
+  "--condition [!] filename       Match on boolean value stored in /proc file"
+  "\n", IPTABLES_VERSION);
+}
+
+static struct option opts[] = { { "condition", 1, 0, 'X' }, { 0 } };
+
+static void init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+  *nfcache |= NFC_UNKNOWN;
+}
+
+static int parse(int c, char **argv, int invert, unsigned int *flags,
+		const struct ipt_entry *entry, unsigned int *nfcache,
+		struct ipt_entry_match **match)
+{
+  struct condition_info *info = (struct condition_info*)(*match)->data;
+
+  check_inverse(optarg, &invert, &optind, 0);
+
+  if(*flags)
+    exit_error(PARAMETER_PROBLEM, "Can't specify multiple conditions");
+
+  if(c == 'X')
+  {
+    if(strlen(argv[optind-1]) < VARIABLE_NAME_LEN)
+      strcpy(info->name, argv[optind-1]);
+    else
+      exit_error(PARAMETER_PROBLEM, "File name too long");
+
+    info->invert = invert;
+    *flags = 1;
+    return 1;
+  }
+
+  return 0;
+}
+
+
+static void final_check(unsigned int flags)
+{
+  if(!flags)
+    exit_error(PARAMETER_PROBLEM, "Condition match: must specify --condition");
+}
+
+
+static void print(const struct ipt_ip *ip,
+		const struct ipt_entry_match *match, int numeric)
+{
+  const struct condition_info *info = (const struct condition_info*)match->data;
+
+  printf("condition %s%s ", (info->invert) ? "!" : "", info->name);
+}
+
+
+static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+  const struct condition_info *info = (const struct condition_info*)match->data;
+
+  printf("--condition %s%s ", (info->invert) ? "! " : "", info->name);
+}
+
+
+static struct iptables_match condition = {
+  NULL,
+  "condition",
+  IPTABLES_VERSION,
+  IPT_ALIGN(sizeof(struct condition_info)),
+  IPT_ALIGN(sizeof(struct condition_info)),
+  &help,
+  &init,
+  &parse,
+  &final_check,
+  &print,
+  &save,
+  opts
+};
+
+
+void _init(void)
+{
+  register_match(&condition);
+}
+