[Thread] Implement read on socket interface

Bug: 313425570
Test: build pass & manual test
Change-Id: I4e6dfdfa73f7145e8f36d05abf1531d7796b4b9e
diff --git a/threadnetwork/aidl/default/socket_interface.cpp b/threadnetwork/aidl/default/socket_interface.cpp
index 6b9b80e..f874209 100644
--- a/threadnetwork/aidl/default/socket_interface.cpp
+++ b/threadnetwork/aidl/default/socket_interface.cpp
@@ -89,6 +89,41 @@
     return OT_ERROR_NONE;
 }
 
+otError SocketInterface::WaitForFrame(uint64_t aTimeoutUs) {
+    otError error = OT_ERROR_NONE;
+    struct timeval timeout;
+    timeout.tv_sec = static_cast<time_t>(aTimeoutUs / US_PER_S);
+    timeout.tv_usec = static_cast<suseconds_t>(aTimeoutUs % US_PER_S);
+
+    fd_set readFds;
+    fd_set errorFds;
+    int rval;
+
+    FD_ZERO(&readFds);
+    FD_ZERO(&errorFds);
+    FD_SET(mSockFd, &readFds);
+    FD_SET(mSockFd, &errorFds);
+
+    rval = TEMP_FAILURE_RETRY(select(mSockFd + 1, &readFds, nullptr, &errorFds, &timeout));
+
+    if (rval > 0) {
+        if (FD_ISSET(mSockFd, &readFds)) {
+            Read();
+        } else if (FD_ISSET(mSockFd, &errorFds)) {
+            DieNowWithMessage("RCP error", OT_EXIT_FAILURE);
+        } else {
+            DieNow(OT_EXIT_FAILURE);
+        }
+    } else if (rval == 0) {
+        ExitNow(error = OT_ERROR_RESPONSE_TIMEOUT);
+    } else {
+        DieNowWithMessage("wait response", OT_EXIT_FAILURE);
+    }
+
+exit:
+    return error;
+}
+
 void SocketInterface::UpdateFdSet(void* aMainloopContext) {
     otSysMainloopContext* context = reinterpret_cast<otSysMainloopContext*>(aMainloopContext);
 
@@ -101,12 +136,69 @@
     }
 }
 
+void SocketInterface::Process(const void* aMainloopContext) {
+    const otSysMainloopContext* context =
+            reinterpret_cast<const otSysMainloopContext*>(aMainloopContext);
+
+    assert(context != nullptr);
+
+    if (FD_ISSET(mSockFd, &context->mReadFdSet)) {
+        Read();
+    }
+}
+
+void SocketInterface::Read(void) {
+    uint8_t buffer[kMaxFrameSize];
+
+    ssize_t rval = TEMP_FAILURE_RETRY(read(mSockFd, buffer, sizeof(buffer)));
+
+    if (rval > 0) {
+        ProcessReceivedData(buffer, static_cast<uint16_t>(rval));
+    } else if (rval < 0) {
+        DieNow(OT_EXIT_ERROR_ERRNO);
+    } else {
+        otLogCritPlat("Socket connection is closed by remote.");
+        exit(OT_EXIT_FAILURE);
+    }
+}
+
 void SocketInterface::Write(const uint8_t* aFrame, uint16_t aLength) {
     ssize_t rval = TEMP_FAILURE_RETRY(write(mSockFd, aFrame, aLength));
     VerifyOrDie(rval >= 0, OT_EXIT_ERROR_ERRNO);
     VerifyOrDie(rval > 0, OT_EXIT_FAILURE);
 }
 
+void SocketInterface::ProcessReceivedData(const uint8_t* aBuffer, uint16_t aLength) {
+    while (aLength--) {
+        uint8_t byte = *aBuffer++;
+        if (mReceiveFrameBuffer->CanWrite(sizeof(uint8_t))) {
+            IgnoreError(mReceiveFrameBuffer->WriteByte(byte));
+        } else {
+            HandleSocketFrame(this, OT_ERROR_NO_BUFS);
+            return;
+        }
+    }
+    HandleSocketFrame(this, OT_ERROR_NONE);
+}
+
+void SocketInterface::HandleSocketFrame(void* aContext, otError aError) {
+    static_cast<SocketInterface*>(aContext)->HandleSocketFrame(aError);
+}
+
+void SocketInterface::HandleSocketFrame(otError aError) {
+    VerifyOrExit((mReceiveFrameCallback != nullptr) && (mReceiveFrameBuffer != nullptr));
+
+    if (aError == OT_ERROR_NONE) {
+        mReceiveFrameCallback(mReceiveFrameContext);
+    } else {
+        mReceiveFrameBuffer->DiscardFrame();
+        otLogWarnPlat("Process socket frame failed: %s", otThreadErrorToString(aError));
+    }
+
+exit:
+    return;
+}
+
 int SocketInterface::OpenFile(const ot::Url::Url& aRadioUrl) {
     int fd = -1;
     sockaddr_un serverAddress;
diff --git a/threadnetwork/aidl/default/socket_interface.hpp b/threadnetwork/aidl/default/socket_interface.hpp
index 2dd315d..f88e926 100644
--- a/threadnetwork/aidl/default/socket_interface.hpp
+++ b/threadnetwork/aidl/default/socket_interface.hpp
@@ -87,6 +87,21 @@
     otError SendFrame(const uint8_t* aFrame, uint16_t aLength);
 
     /**
+     * Waits for receiving part or all of Spinel frame within specified
+     * interval.
+     *
+     * @param[in]  aTimeout  The timeout value in microseconds.
+     *
+     * @retval OT_ERROR_NONE             Part or all of Spinel frame is
+     * received.
+     * @retval OT_ERROR_RESPONSE_TIMEOUT No Spinel frame is received within @p
+     * aTimeout.
+     * @retval OT_EXIT_FAILURE           RCP error
+     *
+     */
+    otError WaitForFrame(uint64_t aTimeoutUs);
+
+    /**
      * Updates the file descriptor sets with file descriptors used by the radio
      * driver.
      *
@@ -97,6 +112,15 @@
     void UpdateFdSet(void* aMainloopContext);
 
     /**
+     * Performs radio driver processing.
+     *
+     * @param[in]   aMainloopContext  A pointer to the mainloop context
+     * containing fd_sets.
+     *
+     */
+    void Process(const void* aMainloopContext);
+
+    /**
      * Returns the bus speed between the host and the radio.
      *
      * @return   Bus speed in bits/second.
@@ -137,6 +161,17 @@
 
   private:
     /**
+     * Instructs `SocketInterface` to read data from radio over the
+     * socket.
+     *
+     * If a full Spinel frame is received, this method invokes the
+     * `HandleSocketFrame()` (on the `aCallback` object from constructor) to
+     * pass the received frame to be processed.
+     *
+     */
+    void Read(void);
+
+    /**
      * Writes a given frame to the socket.
      *
      * @param[in] aFrame  A pointer to buffer containing the frame to write.
@@ -146,6 +181,22 @@
     void Write(const uint8_t* aFrame, uint16_t aLength);
 
     /**
+     * Process received data.
+     *
+     * If a full frame is finished processing and we obtain the raw Spinel
+     * frame, this method invokes the `HandleSocketFrame()` (on the `aCallback`
+     * object from constructor) to pass the received frame to be processed.
+     *
+     * @param[in] aBuffer  A pointer to buffer containing data.
+     * @param[in] aLength  The length (number of bytes) in the buffer.
+     *
+     */
+    void ProcessReceivedData(const uint8_t* aBuffer, uint16_t aLength);
+
+    static void HandleSocketFrame(void* aContext, otError aError);
+    void HandleSocketFrame(otError aError);
+
+    /**
      * Opens file specified by aRadioUrl.
      *
      * @param[in] aRadioUrl  A reference to object containing path to file and