net: sockets: Bootstrap Sockets API implementation

This adds Kconfig and build infrastructure and implements
zsock_socket() and zsock_close() functions.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>

include/net/socket.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __NET_SOCKET_H
+#define __NET_SOCKET_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int zsock_socket(int family, int type, int proto);
+int zsock_close(int sock);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __NET_SOCKET_H */

subsys/net/lib/Kbuild

@@ -1,3 +1,4 @@
+obj-$(CONFIG_NET_SOCKETS) += sockets/
 obj-$(CONFIG_ZOAP) += zoap/
 obj-$(CONFIG_DNS_RESOLVER) += dns/
 obj-$(CONFIG_MQTT_LIB) += mqtt/

subsys/net/lib/Kconfig

@@ -6,6 +6,8 @@
 
 menu "Network Protocols"
 
+source "subsys/net/lib/sockets/Kconfig"
+
 source "subsys/net/lib/zoap/Kconfig"
 
 source "subsys/net/lib/dns/Kconfig"

subsys/net/lib/Makefile

@@ -1,3 +1,7 @@
+ifdef CONFIG_NET_SOCKETS
+include $(srctree)/subsys/net/lib/sockets/Makefile
+endif
+
 ifdef CONFIG_ZOAP
 include $(srctree)/subsys/net/lib/zoap/Makefile
 endif

subsys/net/lib/sockets/Kconfig

@@ -0,0 +1,24 @@
+# Kconfig - BSD Sockets like API
+
+#
+# Copyright (c) 2017 Linaro Limited.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig NET_SOCKETS
+	bool "BSD Sockets like API"
+	default n
+	help
+	Provide BSD Sockets like API on top of native Zephyr networking API.
+
+if NET_SOCKETS
+
+config NET_DEBUG_SOCKETS
+	bool "Debug BSD Sockets like API calls"
+	default n
+	help
+	Enables logging for sockets code. (Logging level is defined by
+	SYS_LOG_NET_LEVEL setting).
+
+endif # NET_SOCKETS

subsys/net/lib/sockets/Makefile

@@ -0,0 +1,3 @@
+ccflags-y += -I$(srctree)/subsys/net/lib/sockets
+
+obj-$(CONFIG_NET_SOCKETS) += sockets.o

subsys/net/lib/sockets/sockets.c

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#if defined(CONFIG_NET_DEBUG_SOCKETS)
+#define SYS_LOG_DOMAIN "net/sock"
+#define NET_LOG_ENABLED 1
+#endif
+
+#include <net/net_context.h>
+#include <net/net_pkt.h>
+#include <net/socket.h>
+
+#define SET_ERRNO(x) \
+	{ int _err = x; if (_err < 0) { errno = -_err; return -1; } }
+
+int zsock_socket(int family, int type, int proto)
+{
+	struct net_context *ctx;
+
+	SET_ERRNO(net_context_get(family, type, proto, &ctx));
+	/* recv_q and accept_q are in union */
+	k_fifo_init(&ctx->recv_q);
+
+	/* TODO: Ensure non-negative */
+	return POINTER_TO_INT(ctx);
+}
+
+int zsock_close(int sock)
+{
+	struct net_context *ctx = INT_TO_POINTER(sock);
+
+	SET_ERRNO(net_context_put(ctx));
+	return 0;
+}