Default implementation for CAN bus HAL
This implementation supports SocketCAN interfaces.
Bug: 135918744
Test: VTS (separate new change)
Change-Id: I12b93e37fa64e341bee2c64eaf130b39977fcef5
diff --git a/automotive/can/1.0/default/libnetdevice/NetlinkSocket.h b/automotive/can/1.0/default/libnetdevice/NetlinkSocket.h
new file mode 100644
index 0000000..81d6224
--- /dev/null
+++ b/automotive/can/1.0/default/libnetdevice/NetlinkSocket.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "NetlinkRequest.h"
+
+#include <android-base/macros.h>
+#include <android-base/unique_fd.h>
+
+#include <linux/netlink.h>
+
+namespace android {
+namespace netdevice {
+
+/**
+ * A wrapper around AF_NETLINK sockets.
+ *
+ * This class is not thread safe to use a single instance between multiple threads, but it's fine to
+ * use multiple instances over multiple threads.
+ */
+struct NetlinkSocket {
+ NetlinkSocket(int protocol);
+
+ /**
+ * Send Netlink message to Kernel.
+ *
+ * @param msg Message to send, nlmsg_seq will be set to next sequence number
+ * @return true, if succeeded
+ */
+ template <class T, unsigned int BUFSIZE>
+ bool send(NetlinkRequest<T, BUFSIZE>& req) {
+ if (!req.isGood()) return false;
+ return send(req.header());
+ }
+
+ /**
+ * Receive Netlink ACK message from Kernel.
+ *
+ * @return true if received ACK message, false in case of error
+ */
+ bool receiveAck();
+
+ private:
+ uint32_t mSeq = 0;
+ base::unique_fd mFd;
+ bool mFailed = false;
+
+ bool send(struct nlmsghdr* msg);
+
+ DISALLOW_COPY_AND_ASSIGN(NetlinkSocket);
+};
+
+} // namespace netdevice
+} // namespace android