3 files changed, 47 insertions, 0 deletions
diff --git a/core/modules/rdns/module.build b/core/modules/rdns/module.build
new file mode 100644
index 00000000..1469a09f
--- /dev/null
+++ b/core/modules/rdns/module.build
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+fetch_source() {
+	:
+}
+
+build() {
+	mkdir -p "$MODULE_BUILD_DIR/opt/openslx/bin"
+	gcc -o "$MODULE_BUILD_DIR/opt/openslx/bin/rdns" "$MODULE_DIR/rdns.c" || perror "Compiling rdns failed."
+}
+
+post_copy() {
+	:
+}
+
diff --git a/core/modules/rdns/module.conf b/core/modules/rdns/module.conf
new file mode 100644
index 00000000..049b374f
--- /dev/null
+++ b/core/modules/rdns/module.conf
@@ -0,0 +1,4 @@
+#!/bin/bash
+REQUIRED_BINARIES="
+	rdns
+"
diff --git a/core/modules/rdns/rdns.c b/core/modules/rdns/rdns.c
new file mode 100644
index 00000000..218f7400
--- /dev/null
+++ b/core/modules/rdns/rdns.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <errno.h>
+#include <netdb.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+int main(int argc, char *argv[])
+{
+	if (argc != 2) {
+		fprintf(stderr,"usage: %s <IPADDRESS>\n", argv[0]);
+		return 1;
+	}
+
+	struct hostent *he;
+	struct in_addr ipv4addr;
+	struct in6_addr ipv6addr;
+
+	inet_pton(AF_INET, argv[1], &ipv4addr);
+	he = gethostbyaddr(&ipv4addr, sizeof ipv4addr, AF_INET);
+	if (he == NULL) return 2;
+	if (he->h_name == NULL) return 3;
+	printf("%s\n", he->h_name);
+
+	return 0;
+}
+