Add user-space networking stack API (usrsock)

User-space networking stack API allows user-space daemon to
provide TCP/IP stack implementation for NuttX network.

Main use for this is to allow use and seamless integration of
HW-provided TCP/IP stacks to NuttX.

For example, user-space daemon can translate /dev/usrsock
API requests to HW TCP/IP API requests while rest of the
user-space can access standard socket API, with socket
descriptors that can be used with NuttX system calls.

include/nuttx/net/netconfig.h

@@ -97,7 +97,7 @@
  *
  *   - Maximum Transfer Unit (MTU)
  *   - TCP Receive Window size (See TCP configuration options below)
- * 
+ *
  * A better solution would be to support device-by-device MTU and receive
  * window sizes.  This minimum support is require to support the optimal
  * SLIP MTU of 296 bytes and the standard Ethernet MTU of 1500
@@ -547,6 +547,18 @@
 #  define CONFIG_NET_ARP_MAXAGE 120
 #endif
 
+/* Usrsock configuration options */
+
+/* The maximum amount of concurrent usrsock connections, Default: 6 */
+
+#ifndef CONFIG_NET_USRSOCK_CONNS
+#  ifdef CONFIG_NET_USRSOCK
+#    define CONFIG_NET_USRSOCK_CONNS 6
+#  else
+#    define CONFIG_NET_USRSOCK_CONNS 0
+#  endif
+#endif
+
 /* General configuration options */
 
 /* Delay after receive to catch a following packet.  No delay should be

include/nuttx/net/usrsock.h

@@ -0,0 +1,233 @@
+/****************************************************************************
+ * include/nuttx/net/usrsock.h
+ *
+ *  Copyright (C) 2015, 2017 Haltian Ltd. All rights reserved.
+ *  Author: Jussi Kivilinna <jussi.kivilinna@haltian.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_NET_USRSOCK_H
+#define __INCLUDE_NUTTX_NET_USRSOCK_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <nuttx/net/netconfig.h>
+#include <nuttx/compiler.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Event message flags */
+
+#define USRSOCK_EVENT_ABORT          (1 << 0)
+#define USRSOCK_EVENT_SENDTO_READY   (1 << 1)
+#define USRSOCK_EVENT_RECVFROM_AVAIL (1 << 2)
+#define USRSOCK_EVENT_REMOTE_CLOSED  (1 << 3)
+
+/* Response message flags */
+
+#define USRSOCK_MESSAGE_FLAG_REQ_IN_PROGRESS (1 << 0)
+#define USRSOCK_MESSAGE_FLAG_EVENT           (1 << 1)
+
+#define USRSOCK_MESSAGE_IS_EVENT(flags) \
+                          (!!((flags) & USRSOCK_MESSAGE_FLAG_EVENT))
+#define USRSOCK_MESSAGE_IS_REQ_RESPONSE(flags) \
+                          (!USRSOCK_MESSAGE_IS_EVENT(flags))
+
+#define USRSOCK_MESSAGE_REQ_IN_PROGRESS(flags) \
+                          (!!((flags) & USRSOCK_MESSAGE_FLAG_REQ_IN_PROGRESS))
+#define USRSOCK_MESSAGE_REQ_COMPLETED(flags) \
+                          (!USRSOCK_MESSAGE_REQ_IN_PROGRESS(flags))
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* Request types */
+
+enum usrsock_request_types_e
+{
+  USRSOCK_REQUEST_SOCKET = 0,
+  USRSOCK_REQUEST_CLOSE,
+  USRSOCK_REQUEST_CONNECT,
+  USRSOCK_REQUEST_SENDTO,
+  USRSOCK_REQUEST_RECVFROM,
+  USRSOCK_REQUEST_SETSOCKOPT,
+  USRSOCK_REQUEST_GETSOCKOPT,
+  USRSOCK_REQUEST_GETSOCKNAME,
+  USRSOCK_REQUEST_BIND,
+  USRSOCK_REQUEST__MAX
+};
+
+/* Response/event message types */
+
+enum usrsock_message_types_e
+{
+  USRSOCK_MESSAGE_RESPONSE_ACK = 0,
+  USRSOCK_MESSAGE_RESPONSE_DATA_ACK,
+  USRSOCK_MESSAGE_SOCKET_EVENT,
+};
+
+/* Request structures (kernel => /dev/usrsock => daemon) */
+
+begin_packed_struct struct usrsock_request_common_s
+{
+  int8_t reqid;
+  uint8_t xid;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_socket_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t domain;
+  int16_t type;
+  int16_t protocol;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_close_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_bind_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+  uint16_t addrlen;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_connect_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+  uint16_t addrlen;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_sendto_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+  uint16_t addrlen;
+  uint16_t buflen;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_recvfrom_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+  uint16_t max_buflen;
+  uint16_t max_addrlen;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_setsockopt_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+  int16_t level;
+  int16_t option;
+  uint16_t valuelen;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_getsockopt_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+  int16_t level;
+  int16_t option;
+  uint16_t max_valuelen;
+} end_packed_struct;
+
+begin_packed_struct struct usrsock_request_getsockname_s
+{
+  struct usrsock_request_common_s head;
+
+  int16_t usockid;
+  uint16_t max_addrlen;
+} end_packed_struct;
+
+/* Response/event message structures (kernel <= /dev/usrsock <= daemon) */
+
+begin_packed_struct struct usrsock_message_common_s
+{
+  int8_t msgid;
+  int8_t flags;
+} end_packed_struct;
+
+/* Request acknowledgment/completion message */
+
+begin_packed_struct struct usrsock_message_req_ack_s
+{
+  struct usrsock_message_common_s head;
+
+  uint8_t xid;
+  int32_t result;
+} end_packed_struct;
+
+/* Request acknowledgment/completion message */
+
+begin_packed_struct struct usrsock_message_datareq_ack_s
+{
+  struct usrsock_message_req_ack_s reqack;
+
+  /* head.result => positive buflen, negative error-code. */
+
+  uint16_t valuelen;          /* length of value returned after buffer */
+  uint16_t valuelen_nontrunc; /* actual non-truncated length of value at
+                               * daemon-sïde. */
+} end_packed_struct;
+
+/* Socket event message */
+
+begin_packed_struct struct usrsock_message_socket_event_s
+{
+  struct usrsock_message_common_s head;
+
+  int16_t usockid;
+  uint16_t events;
+} end_packed_struct;
+
+#endif /* __INCLUDE_NUTTX_NET_USRSOCK_H */

net/Kconfig

@@ -236,6 +236,23 @@ config TUN_LPWORK
 endchoice # Work queue
 endif # NET_TUN
 
+config NET_USRSOCK
+	bool "User-space networking stack API"
+	default n
+	---help---
+		Enable or disable user-space networking stack support.
+
+		User-space networking stack API allows user-space daemon to
+		provide TCP/IP stack implementation for NuttX network.
+
+		Main use for this is to allow use and integration of
+		HW-provided TCP/IP stacks for NuttX.
+
+		For example, user-space daemon can translate /dev/usrsock API
+		requests to HW TCP/IP API requests while rest of the user-space
+		can access standard socket API, with socket descriptors that
+		can be used with NuttX system calls.
+
 endmenu # Data link support
 
 source "net/netdev/Kconfig"
@@ -271,6 +288,7 @@ source "net/arp/Kconfig"
 source "net/loopback/Kconfig"
 source "net/iob/Kconfig"
 source "net/procfs/Kconfig"
+source "net/usrsock/Kconfig"
 source "net/utils/Kconfig"
 
 config NET_STATISTICS

net/Makefile

@@ -72,6 +72,7 @@ include devif/Make.defs
 include loopback/Make.defs
 include route/Make.defs
 include procfs/Make.defs
+include usrsock/Make.defs
 include utils/Make.defs
 endif
 

net/README.txt

@@ -22,21 +22,25 @@ Directory Structure
        +- route    - Routing table support
        +- tcp      - Transmission Control Protocol
        +- udp      - User Datagram Protocol
+       +- usrsock  - User socket API for user-space networking stack
        `- utils    - Miscellaneous utility functions
 
 
-    +----------------------------------------------------------------+
-    |                     Application layer                          |
-    +----------------------------------------------------------------+
-    +----------------------------------------------------------------+
-    |                   Socket layer (socket/)                       |
-    +----------------------------------------------------------------+
-    +------------++--------------------------------------------------+
-    |  Network   || Protocol stacks (arp, ipv6, icmp, pkt, tcp, udp) |
-    |   Device   |+--------------------------------------------------+
-    | Interface  |+------------------------------------++------------+
-    | (netdev/)  ||  Network Device Interface (devif/) || Utilities  |
-    +------------++------------------------------------++------------+
-    +----------------------------------------------------------------+
-    |                    Network Device Drivers                      |
-    +----------------------------------------------------------------+
+    +-------------------------------------------------------------------++------------------------+
+    |                     Application layer                             || usrsock daemon         |
+    +-------------------------------------------------------------------++------------------------+
+    +-------------------------------------------------------------------++----------------+ +-----+
+    |                   Socket layer (socket/)                          || /dev/usrsock   | |     |
+    +-------------------------------------------------------------------++----------------+ |     |
+    +------------++--------------------------------------------------++-------------------+ |     |
+    |  Network   || Protocol stacks (arp, ipv6, icmp, pkt, tcp, udp) || usrsock/          | |     |
+    |   Device   |+--------------------------------------------------++-------------------+ |     |
+    | Interface  |+------------------------------------++---------------------------------+ |     |
+    | (netdev/)  ||  Network Device Interface (devif/) || Utilities                       | |     |
+    +------------++------------------------------------++---------------------------------+ |     |
+    +----------------------------------------------------------------+                      |     |
+    |                    Network Device Drivers                      |                      | HAL |
+    +----------------------------------------------------------------+                      +-----+
+    +----------------------------------------------------------------+ +--------------------------+
+    |                    Networking Hardware                         | |  Hardware TCP/IP Stack   |
+    +----------------------------------------------------------------+ +--------------------------+

net/devif/devif.h

@@ -234,12 +234,17 @@
  */
 
 struct net_driver_s;       /* Forward reference */
+
+typedef CODE uint16_t (*devif_callback_event_t)(FAR struct net_driver_s *dev,
+                                                FAR void *pvconn,
+                                                FAR void *pvpriv,
+                                                uint16_t flags);
+
 struct devif_callback_s
 {
   FAR struct devif_callback_s *nxtconn;
   FAR struct devif_callback_s *nxtdev;
-  uint16_t (*event)(FAR struct net_driver_s *dev, FAR void *pvconn,
-                    FAR void *pvpriv, uint16_t flags);
+  FAR devif_callback_event_t event;
   FAR void *priv;
   uint16_t flags;
 };