net: sockets: mgmt: Add AF_NET_MGMT address family support

Allow application to listen network management events using
BSD socket API. Application needs to create the socket using
AF_NET_MGMT address family. At this point we only support
receiving network management events that the network subsystem
is sending.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

include/net/net_ip.h

@@ -44,13 +44,15 @@ extern "C" {
 #define PF_INET6        2          /**< IP protocol family version 6. */
 #define PF_PACKET       3          /**< Packet family.                */
 #define PF_CAN          4          /**< Controller Area Network.      */
+#define PF_NET_MGMT     5          /**< Network management info.      */
 
 /* Address families. */
-#define AF_UNSPEC       PF_UNSPEC  /**< Unspecified address family.   */
-#define AF_INET         PF_INET    /**< IP protocol family version 4. */
-#define AF_INET6        PF_INET6   /**< IP protocol family version 6. */
-#define AF_PACKET       PF_PACKET  /**< Packet family.                */
-#define AF_CAN          PF_CAN     /**< Controller Area Network.      */
+#define AF_UNSPEC      PF_UNSPEC   /**< Unspecified address family.   */
+#define AF_INET        PF_INET     /**< IP protocol family version 4. */
+#define AF_INET6       PF_INET6    /**< IP protocol family version 6. */
+#define AF_PACKET      PF_PACKET   /**< Packet family.                */
+#define AF_CAN         PF_CAN      /**< Controller Area Network.      */
+#define AF_NET_MGMT    PF_NET_MGMT /**< Network management info.      */
 
 /** Protocol numbers from IANA/BSD */
 enum net_ip_protocol {

include/net/socket_net_mgmt.h

@@ -0,0 +1,107 @@
+/** @file
+ * @brief NET_MGMT socket definitions.
+ *
+ * Definitions for NET_MGMT socket support.
+ */
+
+/*
+ * Copyright (c) 2019 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_NET_SOCKET_NET_MGMT_H_
+#define ZEPHYR_INCLUDE_NET_SOCKET_NET_MGMT_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <zephyr/types.h>
+#include <net/net_ip.h>
+#include <net/net_if.h>
+#include <net/net_mgmt.h>
+
+/**
+ * @brief Socket NET_MGMT library
+ * @defgroup socket_net_mgmt Network Core Library
+ * @ingroup networking
+ * @{
+ */
+
+/* Protocols of the protocol family PF_NET_MGMT */
+#define NET_MGMT_EVENT_PROTO 0x01
+
+/* Socket NET_MGMT options */
+#define SOL_NET_MGMT_BASE 100
+#define SOL_NET_MGMT_RAW (SOL_NET_MGMT_BASE + NET_MGMT_RAW)
+
+/**
+ * struct sockaddr_nm - The sockaddr structure for NET_MGMT sockets
+ *
+ * Similar concepts are used as in Linux AF_NETLINK. The NETLINK name is not
+ * used in order to avoid confusion between Zephyr and Linux as the
+ * implementations are different.
+ *
+ * The socket domain (address family) is AF_NET_MGMT, and the type of socket
+ * is either SOCK_RAW or SOCK_DGRAM, because this is a datagram-oriented
+ * service.
+ *
+ * The protocol (protocol type) selects for which feature the socket is used.
+ *
+ * When used with bind(), the nm_pid field of the sockaddr_nm can be
+ * filled with the calling thread' own id. The nm_pid serves here as the local
+ * address of this net_mgmt socket. The application is responsible for picking
+ * a unique 32-bit integer to fill in nm_pid.
+ */
+struct sockaddr_nm {
+	/** AF_NET_MGMT address family. */
+	sa_family_t nm_family;
+
+	/** Network interface related to this address */
+	int nm_ifindex;
+
+	/** Thread id or similar that is used to separate the different
+	 * sockets. Application can decide how the pid is constructed.
+	 */
+	u32_t nm_pid;
+
+	/** net_mgmt mask */
+	u32_t nm_mask;
+};
+
+
+/**
+ * Each network management message is prefixed with this header.
+ */
+struct net_mgmt_msghdr {
+	/** Network management version */
+	u32_t nm_msg_version;
+
+	/** Length of the data */
+	u32_t nm_msg_len;
+
+	/** The actual message data follows */
+	u8_t nm_msg[];
+};
+
+/**
+ * Version of the message is placed to the header. Currently we have
+ * following versions.
+ *
+ * Network management message versions:
+ *
+ *  0x0001 : The net_mgmt event info message follows directly
+ *           after the header.
+ */
+#define NET_MGMT_SOCKET_VERSION_1 0x0001
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZEPHYR_INCLUDE_NET_SOCKET_NET_MGMT_H_ */

subsys/net/lib/sockets/CMakeLists.txt

@@ -16,4 +16,9 @@ zephyr_sources_ifdef(CONFIG_NET_SOCKETS_CAN sockets_can.c)
 endif()
 zephyr_sources_ifdef(CONFIG_NET_SOCKETS_OFFLOAD     socket_offload.c)
 
+if(CONFIG_NET_SOCKETS_NET_MGMT)
+  zephyr_sources(sockets_net_mgmt.c)
+  zephyr_include_directories(${ZEPHYR_BASE}/subsys/net/ip)
+endif()
+
 zephyr_link_libraries_ifdef(CONFIG_MBEDTLS mbedTLS)

subsys/net/lib/sockets/Kconfig

@@ -141,6 +141,24 @@ config NET_SOCKETS_CAN_RECEIVERS
 	  The value tells how many sockets can receive data from same
 	  Socket-CAN interface.
 
+config NET_SOCKETS_NET_MGMT
+	bool "Enable network mangement socket support [EXPERIMENTAL]"
+	depends on NET_MGMT_EVENT
+	select NET_MGMT_EVENT_INFO
+	help
+	  Select this if you want to use socket API to get network
+	  managements events to your application.
+
+config NET_SOCKETS_NET_MGMT_MAX_LISTENERS
+	int "Max number of sockets to listen"
+	default 1
+	depends on NET_SOCKETS_NET_MGMT
+	help
+	  This sets the maximum number of net_mgmt sockets that can
+	  be set by the socket interface. So if you have two separate
+	  sockets that are used for listening events, you need to set
+	  this to two.
+
 module = NET_SOCKETS
 module-dep = NET_LOG
 module-str = Log level for BSD sockets compatible API calls