diff --git a/src/common/ctrl_iface_common.c b/src/common/ctrl_iface_common.c
new file mode 100644
index 000000000..d08b4a5dc
--- /dev/null
+++ b/src/common/ctrl_iface_common.c
@@ -0,0 +1,159 @@
+/*
+ * Common hostapd/wpa_supplicant ctrl iface code.
+ * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2015, Qualcomm Atheros, Inc.
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "utils/includes.h"
+#include <netdb.h>
+#include <sys/un.h>
+
+#include "utils/common.h"
+#include "ctrl_iface_common.h"
+
+static int sockaddr_compare(struct sockaddr_storage *a, socklen_t a_len,
+			    struct sockaddr_storage *b, socklen_t b_len)
+{
+	struct sockaddr_in *in_a, *in_b;
+	struct sockaddr_in6 *in6_a, *in6_b;
+	struct sockaddr_un *u_a, *u_b;
+
+	if (a->ss_family != b->ss_family)
+		return 1;
+
+	switch (a->ss_family) {
+	case AF_INET:
+		in_a = (struct sockaddr_in *) a;
+		in_b = (struct sockaddr_in *) b;
+
+		if (in_a->sin_port != in_b->sin_port)
+			return 1;
+		if (in_a->sin_addr.s_addr != in_b->sin_addr.s_addr)
+			return 1;
+		break;
+	case AF_INET6:
+		in6_a = (struct sockaddr_in6 *) a;
+		in6_b = (struct sockaddr_in6 *) b;
+
+		if (in6_a->sin6_port != in6_b->sin6_port)
+			return 1;
+		if (os_memcmp(&in6_a->sin6_addr, &in6_b->sin6_addr,
+			      sizeof(in6_a->sin6_addr)) != 0)
+			return 1;
+		break;
+	case AF_UNIX:
+		u_a = (struct sockaddr_un *) a;
+		u_b = (struct sockaddr_un *) b;
+
+		if (a_len != b_len ||
+		    os_memcmp(u_a->sun_path, u_b->sun_path,
+			      a_len - offsetof(struct sockaddr_un, sun_path))
+		    != 0)
+			return 1;
+		break;
+	default:
+		return 1;
+	}
+
+	return 0;
+}
+
+
+void sockaddr_print(int level, const char *msg, struct sockaddr_storage *sock,
+		    socklen_t socklen)
+{
+	char host[NI_MAXHOST] = { 0 };
+	char service[NI_MAXSERV] = { 0 };
+	char addr_txt[200];
+
+	switch (sock->ss_family) {
+	case AF_INET:
+	case AF_INET6:
+		getnameinfo((struct sockaddr *) sock, socklen,
+			    host, sizeof(host),
+			    service, sizeof(service),
+			    NI_NUMERICHOST);
+
+		wpa_printf(level, "%s %s:%s", msg, host, service);
+		break;
+	case AF_UNIX:
+		printf_encode(addr_txt, sizeof(addr_txt),
+			      (u8 *) ((struct sockaddr_un *) sock)->sun_path,
+			      socklen - offsetof(struct sockaddr_un, sun_path));
+		wpa_printf(level, "%s %s", msg, addr_txt);
+		break;
+	default:
+		wpa_printf(level, "%s", msg);
+		break;
+	}
+}
+
+
+int ctrl_iface_attach(struct dl_list *ctrl_dst, struct sockaddr_un *from,
+		      socklen_t fromlen)
+{
+	struct wpa_ctrl_dst *dst;
+
+	dst = os_zalloc(sizeof(*dst));
+	if (dst == NULL)
+		return -1;
+	os_memcpy(&dst->addr, from, fromlen);
+	dst->addrlen = fromlen;
+	dst->debug_level = MSG_INFO;
+	dl_list_add(ctrl_dst, &dst->list);
+
+	sockaddr_print(MSG_DEBUG, "CTRL_IFACE monitor attached",
+		       (struct sockaddr_storage *) from, fromlen);
+	return 0;
+}
+
+
+int ctrl_iface_detach(struct dl_list *ctrl_dst, struct sockaddr_un *from,
+		      socklen_t fromlen)
+{
+	struct wpa_ctrl_dst *dst;
+
+	dl_list_for_each(dst, ctrl_dst, struct wpa_ctrl_dst, list) {
+		if (!sockaddr_compare((struct sockaddr_storage *) from,
+				      fromlen,
+				      (struct sockaddr_storage *) &dst->addr,
+				      dst->addrlen)) {
+			sockaddr_print(MSG_DEBUG, "CTRL_IFACE monitor detached",
+				       (struct sockaddr_storage *) from,
+				       fromlen);
+			dl_list_del(&dst->list);
+			os_free(dst);
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+
+int ctrl_iface_level(struct dl_list *ctrl_dst, struct sockaddr_un *from,
+		     socklen_t fromlen, const char *level)
+{
+	struct wpa_ctrl_dst *dst;
+
+	wpa_printf(MSG_DEBUG, "CTRL_IFACE LEVEL %s", level);
+
+	dl_list_for_each(dst, ctrl_dst, struct wpa_ctrl_dst, list) {
+		if (!sockaddr_compare((struct sockaddr_storage *) from,
+				      fromlen,
+				      (struct sockaddr_storage *) &dst->addr,
+				      dst->addrlen)) {
+			sockaddr_print(MSG_DEBUG,
+				       "CTRL_IFACE changed monitor level",
+				       (struct sockaddr_storage *) from,
+				       fromlen);
+			dst->debug_level = atoi(level);
+			return 0;
+		}
+	}
+
+	return -1;
+}
diff --git a/src/common/ctrl_iface_common.h b/src/common/ctrl_iface_common.h
new file mode 100644
index 000000000..684409396
--- /dev/null
+++ b/src/common/ctrl_iface_common.h
@@ -0,0 +1,38 @@
+/*
+ * Common hostapd/wpa_supplicant ctrl iface code.
+ * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2015, Qualcomm Atheros, Inc.
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+#ifndef CONTROL_IFACE_COMMON_H
+#define CONTROL_IFACE_COMMON_H
+
+#include "utils/list.h"
+
+/**
+ * struct wpa_ctrl_dst - Data structure of control interface monitors
+ *
+ * This structure is used to store information about registered control
+ * interface monitors into struct wpa_supplicant.
+ */
+struct wpa_ctrl_dst {
+	struct dl_list list;
+	struct sockaddr_un addr;
+	socklen_t addrlen;
+	int debug_level;
+	int errors;
+};
+
+void sockaddr_print(int level, const char *msg, struct sockaddr_storage *sock,
+		    socklen_t socklen);
+
+int ctrl_iface_attach(struct dl_list *ctrl_dst, struct sockaddr_un *from,
+		       socklen_t fromlen);
+int ctrl_iface_detach(struct dl_list *ctrl_dst, struct sockaddr_un *from,
+		      socklen_t fromlen);
+int ctrl_iface_level(struct dl_list *ctrl_dst, struct sockaddr_un *from,
+		     socklen_t fromlen, const char *level);
+
+#endif /* CONTROL_IFACE_COMMON_H */