libsysutils: add some rudimentary tests

Test: atest libsysutils_tests
Change-Id: I3aa44c5af821c3161cf598b86216480d2424d336

libsysutils/Android.bp

@@ -27,3 +27,16 @@ cc_library_shared {
 
     export_include_dirs: ["include"],
 }
+
+cc_test {
+    name: "libsysutils_tests",
+    test_suites: ["device-tests"],
+    srcs: [
+        "src/SocketListener_test.cpp",
+    ],
+    shared_libs: [
+        "libbase",
+        "libcutils",
+        "libsysutils",
+    ],
+}

libsysutils/include/sysutils/FrameworkListener.h

@@ -38,13 +38,13 @@ public:
     FrameworkListener(const char *socketName);
     FrameworkListener(const char *socketName, bool withSeq);
     FrameworkListener(int sock);
-    virtual ~FrameworkListener() {}
+    ~FrameworkListener() override {}
 
-protected:
+  protected:
     void registerCmd(FrameworkCommand *cmd);
-    virtual bool onDataAvailable(SocketClient *c);
+    bool onDataAvailable(SocketClient* c) override;
 
-private:
+  private:
     void dispatchCommand(SocketClient *c, char *data);
     void init(const char *socketName, bool withSeq);
 };

libsysutils/src/SocketListener.cpp

@@ -52,7 +52,6 @@ void SocketListener::init(const char *socketName, int socketFd, bool listen, boo
     mSock = socketFd;
     mUseCmdNum = useCmdNum;
     pthread_mutex_init(&mClientsLock, nullptr);
-    mClients = new SocketClientCollection();
 }
 
 SocketListener::~SocketListener() {

libsysutils/src/SocketListener_test.cpp

@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2018 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 <sysutils/FrameworkListener.h>
+
+#include <poll.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <algorithm>
+#include <memory>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+#include <gtest/gtest.h>
+
+using android::base::unique_fd;
+
+namespace {
+
+std::string testSocketPath() {
+    const testing::TestInfo* const test_info =
+            testing::UnitTest::GetInstance()->current_test_info();
+    return std::string(ANDROID_SOCKET_DIR "/") + std::string(test_info->test_case_name()) +
+           std::string(".") + std::string(test_info->name());
+}
+
+unique_fd serverSocket(const std::string& path) {
+    unlink(path.c_str());
+
+    unique_fd fd(socket(PF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0));
+    EXPECT_GE(fd.get(), 0);
+
+    struct sockaddr_un addr = {.sun_family = AF_UNIX};
+    strlcpy(addr.sun_path, path.c_str(), sizeof(addr.sun_path));
+
+    EXPECT_EQ(bind(fd.get(), reinterpret_cast<sockaddr*>(&addr), sizeof(addr)), 0)
+            << "bind() to " << path << " failed: " << strerror(errno);
+    EXPECT_EQ(android_get_control_socket(path.c_str()), -1);
+
+    return fd;
+}
+
+unique_fd clientSocket(const std::string& path) {
+    unique_fd fd(socket(PF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0));
+    EXPECT_GE(fd.get(), 0);
+
+    struct sockaddr_un addr = {.sun_family = AF_UNIX};
+    strlcpy(addr.sun_path, path.c_str(), sizeof(addr.sun_path));
+
+    EXPECT_EQ(0, connect(fd.get(), reinterpret_cast<sockaddr*>(&addr), sizeof(addr)))
+            << "connect() to " << path << " failed: " << strerror(errno);
+
+    return fd;
+}
+
+void sendCmd(int fd, const char* cmd) {
+    EXPECT_TRUE(android::base::WriteFully(fd, cmd, strlen(cmd) + 1))
+            << "write() to socket failed: " << strerror(errno);
+}
+
+std::string recvReply(int fd) {
+    pollfd fds = {.fd = fd, .events = POLLIN};
+    int poll_events = poll(&fds, 1, -1);
+    EXPECT_EQ(1, poll_events);
+
+    // Technically, this one-shot read() is incorrect: we should keep on
+    // reading the socket until we get a \0. But this is also how
+    // FrameworkListener::onDataAvailable() reads, and it works because
+    // replies are always send with a single write() call, and clients
+    // always read replies before queueing the next command.
+    char buf[1024];
+    ssize_t len = read(fd, buf, sizeof(buf));
+    EXPECT_GE(len, 0) << "read() from socket failed: " << strerror(errno);
+    return len > 0 ? std::string(buf, buf + len) : "";
+}
+
+// Test command which echoes back all its arguments as a comma-separated list.
+// Always returns error code 42
+//
+// TODO: enable testing replies with addErrno=true and useCmdNum=true
+class TestCommand : public FrameworkCommand {
+  public:
+    TestCommand() : FrameworkCommand("test") {}
+    ~TestCommand() override {}
+
+    int runCommand(SocketClient* cli, int argc, char** argv) {
+        std::vector<std::string> args(argv, argv + argc);
+        std::string reply = android::base::Join(args, ',');
+        cli->sendMsg(42, reply.c_str(), /*addErrno=*/false, /*useCmdNum=*/false);
+        return 0;
+    }
+};
+
+// A test listener with a single command.
+class TestListener : public FrameworkListener {
+  public:
+    TestListener(int fd) : FrameworkListener(fd) {
+        registerCmd(new TestCommand);  // Leaked :-(
+    }
+};
+
+}  // unnamed namespace
+
+class FrameworkListenerTest : public testing::Test {
+  public:
+    FrameworkListenerTest() {
+        mSocketPath = testSocketPath();
+        mSserverFd = serverSocket(mSocketPath);
+        mListener = std::make_unique<TestListener>(mSserverFd.get());
+        EXPECT_EQ(0, mListener->startListener());
+    }
+
+    ~FrameworkListenerTest() override {
+        EXPECT_EQ(0, mListener->stopListener());
+
+        // Wouldn't it be cool if unique_fd had an option for taking care of this?
+        unlink(mSocketPath.c_str());
+    }
+
+    void testCommand(const char* command, const char* expected) {
+        unique_fd client_fd = clientSocket(mSocketPath);
+        sendCmd(client_fd.get(), command);
+
+        std::string reply = recvReply(client_fd.get());
+        EXPECT_EQ(std::string(expected) + '\0', reply);
+    }
+
+  protected:
+    std::string mSocketPath;
+    unique_fd mSserverFd;
+    std::unique_ptr<TestListener> mListener;
+};
+
+TEST_F(FrameworkListenerTest, DoesNothing) {
+    // Let the test harness start and stop a FrameworkListener
+    // without sending any commands through it.
+}
+
+TEST_F(FrameworkListenerTest, DispatchesValidCommands) {
+    testCommand("test", "42 test");
+    testCommand("test arg1 arg2", "42 test,arg1,arg2");
+    testCommand("test \"arg1 still_arg1\" arg2", "42 test,arg1 still_arg1,arg2");
+    testCommand("test \"escaped quote: '\\\"'\"", "42 test,escaped quote: '\"'");
+
+    // Perhaps this behavior was unintended, but would be good to detect any
+    // changes, in case anyone depends on it.
+    testCommand("test   ", "42 test,,,");
+}
+
+TEST_F(FrameworkListenerTest, RejectsInvalidCommands) {
+    testCommand("unknown arg1 arg2", "500 Command not recognized");
+    testCommand("test \"arg1 arg2", "500 Unclosed quotes error");
+    testCommand("test \\a", "500 Unsupported escape sequence");
+}