1 files changed, 267 insertions, 0 deletions
diff --git a/lib/greet/client.vala b/lib/greet/client.vala
new file mode 100644
index 0000000..ee220b5
--- /dev/null
+++ b/lib/greet/client.vala
@@ -0,0 +1,267 @@
+namespace AstalGreet {
+/**
+ * Shorthand for creating a session, posting the password,
+ * and starting the session with the given `cmd`
+ * which is parsed with [[email protected]_parse_argv].
+ *
+ * @param username User to login to
+ * @param password Password of the user
+ * @param cmd Command to start the session with
+ */
+public async void login(
+    string username,
+    string password,
+    string cmd
+) throws GLib.Error {
+    yield login_with_env(username, password, cmd, {});
+}
+
+/**
+ * Same as [[email protected]] but allow for setting additonal env
+ * in the form of `name=value` pairs.
+ *
+ * @param username User to login to
+ * @param password Password of the user
+ * @param cmd Command to start the session with
+ * @param env Additonal env vars to set for the session
+ */
+public async void login_with_env(
+    string username,
+    string password,
+    string cmd,
+    string[] env
+) throws GLib.Error {
+    string[] argv;
+    Shell.parse_argv(cmd, out argv);
+    try {
+        yield new CreateSession(username).send();
+        yield new PostAuthMesssage(password).send();
+        yield new StartSession(argv, env).send();
+    } catch (GLib.Error err) {
+        yield new CancelSession().send();
+        throw err;
+    }
+}
+
+/**
+ * Base Request type.
+ */
+public abstract class Request : Object {
+    protected abstract string type_name { get; }
+
+    private string serialize() {
+        var node = Json.gobject_serialize(this);
+        var obj = node.get_object();
+        obj.set_string_member("type", obj.get_string_member("type-name"));
+        obj.remove_member("type-name");
+
+        return Json.to_string(node, false);
+    }
+
+    private int bytes_to_int(Bytes bytes) {
+        uint8[] data = (uint8[]) bytes.get_data();
+        int value = 0;
+
+        for (int i = 0; i < data.length; i++) {
+            value = (value << 8) | data[i];
+        }
+
+        return value;
+    }
+
+    /**
+     * Send this request to greetd.
+     */
+    public async Response send() throws GLib.Error {
+        var sock = Environment.get_variable("GREETD_SOCK");
+        if (sock == null) {
+            throw new IOError.NOT_FOUND("greetd socket not found");
+        }
+
+        var addr = new UnixSocketAddress(sock);
+        var socket = new SocketClient();
+        var conn = socket.connect(addr);
+        var payload = serialize();
+        var ostream = new DataOutputStream(conn.get_output_stream()) {
+            byte_order = DataStreamByteOrder.HOST_ENDIAN,
+        };
+
+        ostream.put_int32(payload.length, null);
+        ostream.put_string(payload, null);
+        ostream.close(null);
+
+        var istream = conn.get_input_stream();
+
+        var response_head = yield istream.read_bytes_async(4, Priority.DEFAULT, null);
+        var response_length = bytes_to_int(response_head);
+        var response_body = yield istream.read_bytes_async(response_length, Priority.DEFAULT, null);
+
+        var response = (string)response_body.get_data();
+        conn.close(null);
+
+        var parser = new Json.Parser();
+        parser.load_from_data(response);
+        var obj = parser.get_root().get_object();
+        var type = obj.get_string_member("type");
+
+        print(@"$type: $response\n");
+
+        switch (type) {
+            case Success.TYPE: return new Success(obj);
+            case Error.TYPE: return new Error(obj);
+            case AuthMessage.TYPE: return new AuthMessage(obj);
+            default: throw new IOError.NOT_FOUND("unknown response type");
+        }
+    }
+}
+
+/**
+ * Creates a session and initiates a login attempted for the given user.
+ * The session is ready to be started if a success is returned.
+ */
+public class CreateSession : Request {
+    protected override string type_name { get { return "create_session"; } }
+    public string username { get; set; }
+
+    public CreateSession(string username) {
+        Object(username: username);
+    }
+}
+
+/**
+ * Answers an authentication message.
+ * If the message was informative (info, error),
+ * then a response does not need to be set in this message.
+ * The session is ready to be started if a success is returned.
+ */
+public class PostAuthMesssage : Request {
+    protected override string type_name { get { return "post_auth_message_response"; } }
+    public string response { get; set; }
+
+    public PostAuthMesssage(string response) {
+        Object(response: response);
+    }
+}
+
+/**
+ * Requests for the session to be started using the provided command line,
+ * adding the supplied environment to that created by PAM.
+ * The session will start after the greeter process terminates
+ */
+public class StartSession : Request {
+    protected override string type_name { get { return "start_session"; } }
+    public string[] cmd { get; set; }
+    public string[] env { get; set; }
+
+    public StartSession(string[] cmd, string[] env = {}) {
+        Object(cmd: cmd, env: env);
+    }
+}
+
+/**
+ * Cancels the session that is currently under configuration.
+ */
+public class CancelSession : Request {
+    internal override string type_name { get { return "cancel_session"; } }
+}
+
+/**
+ * Base Response type.
+ */
+public abstract class Response : Object {
+    // nothing to do
+}
+
+/**
+ * Indicates that the request succeeded.
+ */
+public class Success : Response {
+    internal const string TYPE = "success";
+
+    internal Success(Json.Object obj) {
+        // nothing to do
+    }
+}
+
+/**
+ * Indicates that the request succeeded.
+ */
+public class Error : Response {
+    internal const string TYPE = "error";
+
+    public enum Type {
+        /**
+         * Indicates that authentication failed.
+         * This is not a fatal error, and is likely caused by incorrect credentials.
+         */
+        AUTH_ERROR,
+        /**
+         * A general error.
+         * See the error description for more information.
+         */
+        ERROR;
+
+        internal static Type from_string(string str) throws IOError {
+            switch (str) {
+                case "auth_error": return Type.AUTH_ERROR;
+                case "error": return Type.ERROR;
+                default: throw new IOError.FAILED(@"unknown error_type: $str");
+            }
+        }
+    }
+
+    public Type error_type { get; private set; }
+    public string description { get; private set; }
+
+    internal Error(Json.Object obj) throws IOError {
+        error_type = Type.from_string(obj.get_string_member("error_type"));
+        description = obj.get_string_member("description");
+    }
+}
+
+/**
+ * Indicates that the request succeeded.
+ */
+public class AuthMessage : Response {
+    internal const string TYPE = "auth_message";
+
+    public enum Type {
+        /**
+         * Indicates that input from the user should be
+         * visible when they answer this question.
+         */
+        VISIBLE,
+        /**
+         * Indicates that input from the user should be
+         * considered secret when they answer this question.
+         */
+        SECRET,
+        /**
+         * Indicates that this message is informative, not a question.
+         */
+        INFO,
+        /**
+         * Indicates that this message is an error, not a question.
+         */
+        ERROR;
+
+        internal static Type from_string(string str) throws IOError {
+            switch (str) {
+                case "visible": return VISIBLE;
+                case "secret": return Type.SECRET;
+                case "info": return Type.INFO;
+                case "error": return Type.ERROR;
+                default: throw new IOError.FAILED(@"unknown message_type: $str");
+            }
+        }
+    }
+
+    public Type message_type { get; private set; }
+    public string message { get; private set; }
+
+    internal AuthMessage(Json.Object obj) throws IOError {
+        message_type = Type.from_string(obj.get_string_member("auth_message_type"));
+        message = obj.get_string_member("auth_message");
+    }
+}
+}