[posix-app] platform UDP (#3070)

This commit defines a set of platform APIs to integrate UDP layer of
OpenThread with that of the platform.

With this commit, services and applications developed upon OpenThread can
also be accessed through platform's own network interface, e.g. socket() on
POSIX.

include/openthread/platform/Makefile.am

@@ -40,6 +40,7 @@ ot_platform_headers                     = \
     random.h                              \
     time.h                                \
     uart.h                                \
+    udp.h                                 \
     spi-slave.h                           \
     settings.h                            \
     messagepool.h                         \

include/openthread/platform/udp.h

@@ -0,0 +1,103 @@
+/*
+ *  Copyright (c) 2018, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  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 of the copyright holder 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 HOLDER 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.
+ */
+
+/**
+ * @file
+ * @brief
+ *   This file includes the abstraction for the platform UDP service.
+ */
+
+#ifndef OPENTHREAD_PLATFORM_UDP_H_
+#define OPENTHREAD_PLATFORM_UDP_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * This function initializes the UDP socket by platform.
+ *
+ * @param[in]   aUdpSocket  A pointer to the UDP socket.
+ *
+ * @retval  OT_ERROR_NONE   Successfully initialized UDP socket by platform.
+ * @retval  OT_ERROR_FAILED Failed to initialize UDP Socket.
+ *
+ */
+otError otPlatUdpSocket(otUdpSocket *aUdpSocket);
+
+/**
+ * This function closes the UDP socket by platform.
+ *
+ * @param[in]   aUdpSocket  A pointer to the UDP socket.
+ *
+ * @retval  OT_ERROR_NONE   Successfully closed UDP socket by platform.
+ * @retval  OT_ERROR_FAILED Failed to close UDP Socket.
+ *
+ */
+otError otPlatUdpClose(otUdpSocket *aUdpSocket);
+
+/**
+ * This function binds the UDP socket by platform.
+ *
+ * @param[in]   aUdpSocket  A pointer to the UDP socket.
+ *
+ * @retval  OT_ERROR_NONE   Successfully binded UDP socket by platform.
+ * @retval  OT_ERROR_FAILED Failed to bind UDP socket.
+ *
+ */
+otError otPlatUdpBind(otUdpSocket *aUdpSocket);
+
+/**
+ * This function connects UDP socket by platform.
+ *
+ * @param[in]   aUdpSocket  A pointer to the UDP socket.
+ *
+ * @retval  OT_ERROR_NONE   Successfully connected by platform.
+ * @retval  OT_ERROR_FAILED Failed to connect UDP socket.
+ *
+ */
+otError otPlatUdpConnect(otUdpSocket *aUdpSocket);
+
+/**
+ * This function sends UDP payload by platform.
+ *
+ * @param[in]   aUdpSocket      A pointer to the UDP socket.
+ * @param[in]   aMessage        A pointer to the message to send.
+ * @param[in]   aMessageInfo    A pointer to the message info associated with @p aMessage.
+ *
+ * @retval  OT_ERROR_NONE   Successfully sent by platform, and @p aMessage is freed.
+ * @retval  OT_ERROR_FAILED Failed to binded UDP socket.
+ *
+ */
+otError otPlatUdpSend(otUdpSocket *aUdpSocket, otMessage *aMessage, const otMessageInfo *aMessageInfo);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // OPENTHREAD_PLATFORM_UDP_H_

include/openthread/udp.h

@@ -89,6 +89,7 @@ typedef struct otUdpSocket
     otSockAddr          mPeerName; ///< The peer IPv6 socket address.
     otUdpReceive        mHandler;  ///< A function pointer to the application callback.
     void *              mContext;  ///< A pointer to application-specific context.
+    void *              mHandle;   ///< A handle to platform's UDP
     struct otUdpSocket *mNext;     ///< A pointer to the next UDP socket (internal use only).
 } otUdpSocket;
 
@@ -253,6 +254,16 @@ void otUdpProxyReceive(otInstance *        aInstance,
                        const otIp6Address *aPeerAddr,
                        uint16_t            aSockPort);
 
+/**
+ * This function gets the existing UDP Sockets.
+ *
+ * @param[in]  aInstance            A pointer to an OpenThread instance.
+ *
+ * @returns A pointer to the first UDP Socket.
+ *
+ */
+otUdpSocket *otUdpGetSockets(otInstance *aInstance);
+
 /**
  * @}
  *