Implement socket/tcp for daemon command

src/main/java/org/asamk/signal/util/IOUtils.java

@@ -1,13 +1,41 @@
 package org.asamk.signal.util;
 
+import org.asamk.signal.commands.exceptions.IOErrorException;
+import org.asamk.signal.commands.exceptions.UserErrorException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.Reader;
 import java.io.StringWriter;
+import java.net.InetSocketAddress;
+import java.net.SocketAddress;
+import java.net.StandardProtocolFamily;
+import java.net.UnixDomainSocketAddress;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
 import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.attribute.PosixFilePermission;
+import java.nio.file.attribute.PosixFilePermissions;
+import java.util.EnumSet;
+import java.util.Set;
+import java.util.function.Supplier;
+
+import jdk.net.ExtendedSocketOptions;
+import jdk.net.UnixDomainPrincipal;
+
+import static java.nio.file.attribute.PosixFilePermission.OWNER_EXECUTE;
+import static java.nio.file.attribute.PosixFilePermission.OWNER_READ;
+import static java.nio.file.attribute.PosixFilePermission.OWNER_WRITE;
 
 public class IOUtils {
 
+    private final static Logger logger = LoggerFactory.getLogger(IOUtils.class);
+
     private IOUtils() {
     }
 
@@ -21,12 +49,101 @@ public class IOUtils {
         return output.toString();
     }
 
+    public static void createPrivateDirectories(File file) throws IOException {
+        if (file.exists()) {
+            return;
+        }
+
+        final var path = file.toPath();
+        try {
+            Set<PosixFilePermission> perms = EnumSet.of(OWNER_READ, OWNER_WRITE, OWNER_EXECUTE);
+            Files.createDirectories(path, PosixFilePermissions.asFileAttribute(perms));
+        } catch (UnsupportedOperationException e) {
+            Files.createDirectories(path);
+        }
+    }
+
     public static File getDataHomeDir() {
         var dataHome = System.getenv("XDG_DATA_HOME");
         if (dataHome != null) {
             return new File(dataHome);
         }
 
+        logger.debug("XDG_DATA_HOME not set, falling back to home dir");
         return new File(new File(System.getProperty("user.home"), ".local"), "share");
     }
+
+    public static File getRuntimeDir() {
+        var runtimeDir = System.getenv("XDG_RUNTIME_DIR");
+        if (runtimeDir != null) {
+            return new File(runtimeDir);
+        }
+
+        logger.debug("XDG_RUNTIME_DIR not set, falling back to temp dir");
+        return new File(System.getProperty("java.io.tmpdir"));
+    }
+
+    public static Supplier<String> getLineSupplier(final Reader reader) {
+        final var bufferedReader = new BufferedReader(reader);
+        return () -> {
+            try {
+                return bufferedReader.readLine();
+            } catch (IOException e) {
+                logger.error("Error occurred while reading line", e);
+                return null;
+            }
+        };
+    }
+
+    public static InetSocketAddress parseInetSocketAddress(final String tcpAddress) throws UserErrorException {
+        final var colonIndex = tcpAddress.lastIndexOf(':');
+        if (colonIndex < 0) {
+            throw new UserErrorException("Invalid tcp bind address: " + tcpAddress);
+        }
+        final String host = tcpAddress.substring(0, colonIndex);
+        final int port;
+        try {
+            port = Integer.parseInt(tcpAddress.substring(colonIndex + 1));
+        } catch (NumberFormatException e) {
+            throw new UserErrorException("Invalid tcp bind address: " + tcpAddress, e);
+        }
+        return new InetSocketAddress(host, port);
+    }
+
+    public static UnixDomainPrincipal getUnixDomainPrincipal(final SocketChannel channel) throws IOException {
+        UnixDomainPrincipal principal = null;
+        try {
+            principal = channel.getOption(ExtendedSocketOptions.SO_PEERCRED);
+        } catch (UnsupportedOperationException ignored) {
+        }
+        return principal;
+    }
+
+    public static ServerSocketChannel bindSocket(final SocketAddress address) throws IOErrorException {
+        final ServerSocketChannel serverChannel;
+        try {
+            preBind(address);
+            serverChannel = address instanceof UnixDomainSocketAddress
+                    ? ServerSocketChannel.open(StandardProtocolFamily.UNIX)
+                    : ServerSocketChannel.open();
+            serverChannel.bind(address);
+            logger.info("Listening on socket: " + address);
+            postBind(address);
+        } catch (IOException e) {
+            throw new IOErrorException("Failed to bind socket: " + e.getMessage(), e);
+        }
+        return serverChannel;
+    }
+
+    private static void preBind(SocketAddress address) throws IOException {
+        if (address instanceof UnixDomainSocketAddress usa) {
+            createPrivateDirectories(usa.getPath().toFile().getParentFile());
+        }
+    }
+
+    private static void postBind(SocketAddress address) {
+        if (address instanceof UnixDomainSocketAddress usa) {
+            usa.getPath().toFile().deleteOnExit();
+        }
+    }
 }