Implement CAN bus HAL tools

These tools are for manual interaction with CAN bus HAL instances.
Meant primarily for testing/debugging, not useful in user builds.

Bug: 135918744
Test: adb shell <tool name>
Change-Id: I1dfbe94c0006f69954806c395cd888f3bf2a4249
diff --git a/automotive/can/1.0/tools/canhalctrl.cpp b/automotive/can/1.0/tools/canhalctrl.cpp
new file mode 100644
index 0000000..fa1048d
--- /dev/null
+++ b/automotive/can/1.0/tools/canhalctrl.cpp
@@ -0,0 +1,181 @@
+/*
+ * 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.
+ */
+
+#include <android-base/logging.h>
+#include <android/hardware/automotive/can/1.0/ICanController.h>
+#include <android/hidl/manager/1.2/IServiceManager.h>
+#include <hidl-utils/hidl-utils.h>
+
+#include <iostream>
+#include <string>
+
+namespace android {
+namespace hardware {
+namespace automotive {
+namespace can {
+
+using ICanController = V1_0::ICanController;
+
+static void usage() {
+    std::cerr << "CAN bus HAL Control tool" << std::endl;
+    std::cerr << std::endl << "usage:" << std::endl << std::endl;
+    std::cerr << "canhalctrl up <bus name> <type> <interface> [baudrate]" << std::endl;
+    std::cerr << "where:" << std::endl;
+    std::cerr << " bus name - name under which ICanBus will be published" << std::endl;
+    std::cerr << " type - one of: virtual, socketcan, slcan, indexed" << std::endl;
+    std::cerr << " interface - hardware identifier (like can0, vcan0, /dev/ttyUSB0)" << std::endl;
+    std::cerr << " baudrate - such as 100000, 125000, 250000, 500000" << std::endl;
+    std::cerr << std::endl;
+    std::cerr << "canhalctrl down <bus name>" << std::endl;
+    std::cerr << "where:" << std::endl;
+    std::cerr << " bus name - name under which ICanBus will be published" << std::endl;
+}
+
+static hidl_vec<hidl_string> getControlServices() {
+    auto manager = hidl::manager::V1_2::IServiceManager::getService();
+    hidl_vec<hidl_string> services;
+    manager->listManifestByInterface(ICanController::descriptor, hidl_utils::fill(&services));
+    if (services.size() == 0) {
+        std::cerr << "No ICanController services registered (missing privileges?)" << std::endl;
+        exit(-1);
+    }
+    return services;
+}
+
+static bool isSupported(sp<ICanController> ctrl, ICanController::InterfaceType iftype) {
+    hidl_vec<ICanController::InterfaceType> supported;
+    if (!ctrl->getSupportedInterfaceTypes(hidl_utils::fill(&supported)).isOk()) return false;
+    return supported.contains(iftype);
+}
+
+static int up(const std::string& busName, ICanController::InterfaceType type,
+              const std::string& interface, uint32_t baudrate) {
+    bool anySupported = false;
+    for (auto&& service : getControlServices()) {
+        auto ctrl = ICanController::getService(service);
+        if (ctrl == nullptr) {
+            std::cerr << "Couldn't open ICanController/" << service;
+            continue;
+        }
+
+        if (!isSupported(ctrl, type)) continue;
+        anySupported = true;
+
+        ICanController::BusConfiguration config = {};
+        config.name = busName;
+        config.iftype = type;
+        config.baudrate = baudrate;
+
+        if (type == ICanController::InterfaceType::INDEXED) {
+            config.interfaceId.index(std::stol(interface));
+        } else {
+            config.interfaceId.address(interface);
+        }
+
+        const auto upresult = ctrl->upInterface(config);
+        if (upresult == ICanController::Result::OK) return 0;
+        std::cerr << "Failed to bring interface up: " << toString(upresult) << std::endl;
+        // Let's continue the loop to try other controllers.
+    }
+
+    if (!anySupported) {
+        std::cerr << "No controller supports " << toString(type) << std::endl;
+    }
+    return -1;
+}
+
+static int down(const std::string& busName) {
+    for (auto&& service : getControlServices()) {
+        auto ctrl = ICanController::getService(service);
+        if (ctrl == nullptr) continue;
+
+        if (ctrl->downInterface(busName)) return 0;
+    }
+
+    std::cerr << "Failed to bring interface " << busName << " down (maybe it's down already?)"
+              << std::endl;
+    return -1;
+}
+
+static std::optional<ICanController::InterfaceType> parseInterfaceType(const std::string& str) {
+    if (str == "virtual") return ICanController::InterfaceType::VIRTUAL;
+    if (str == "socketcan") return ICanController::InterfaceType::SOCKETCAN;
+    if (str == "slcan") return ICanController::InterfaceType::SLCAN;
+    if (str == "indexed") return ICanController::InterfaceType::INDEXED;
+    return std::nullopt;
+}
+
+static int main(int argc, char* argv[]) {
+    base::SetDefaultTag("CanHalControl");
+    base::SetMinimumLogSeverity(android::base::VERBOSE);
+
+    if (argc == 0) {
+        usage();
+        return 0;
+    }
+
+    std::string cmd(argv[0]);
+    argv++;
+    argc--;
+
+    if (cmd == "up") {
+        if (argc < 3 || argc > 4) {
+            std::cerr << "Invalid number of arguments to up command: " << argc << std::endl;
+            usage();
+            return -1;
+        }
+
+        const std::string busName(argv[0]);
+        const std::string typeStr(argv[1]);
+        const std::string interface(argv[2]);
+
+        const auto type = parseInterfaceType(typeStr);
+        if (!type) {
+            std::cerr << "Invalid interface type: " << typeStr << std::endl;
+            usage();
+            return -1;
+        }
+
+        long long baudrate = 0;
+        if (argc == 4) {
+            baudrate = std::stoll(argv[3]);
+        }
+
+        return up(busName, *type, interface, baudrate);
+    } else if (cmd == "down") {
+        if (argc != 1) {
+            std::cerr << "Invalid number of arguments to down command: " << argc << std::endl;
+            usage();
+            return -1;
+        }
+
+        return down(argv[0]);
+    } else {
+        std::cerr << "Invalid command: " << cmd << std::endl;
+        usage();
+        return -1;
+    }
+}
+
+}  // namespace can
+}  // namespace automotive
+}  // namespace hardware
+}  // namespace android
+
+int main(int argc, char* argv[]) {
+    if (argc < 1) return -1;
+    return ::android::hardware::automotive::can::main(--argc, ++argv);
+}