//
// Copyright (c) 2009-2011, Konrad-Zuse-Zentrum fuer Informationstechnik Berlin
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
// Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// Neither the name of the Konrad-Zuse-Zentrum fuer Informationstechnik Berlin
// nor the names of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// AUTHORS: Bjoern Kolbeck (ZIB)
//

// Header for RPC protocol.

option java_package="org.xtreemfs.foundation.pbrpc.generatedinterfaces";
package xtreemfs.pbrpc;

// Encodes the type of the RPC message sent.
enum MessageType {
    // RPC request to execute method.
    RPC_REQUEST = 0;
    // RPC response after successful execution of method.
    RPC_RESPONSE_SUCCESS = 1;
    // RPC response when execution of a method failed, including POSIX errors.
    RPC_RESPONSE_ERROR = 2;
}

// Authentication type provided for request.
enum AuthType {
    // No authentication.
    AUTH_NONE = 0;
    // Plain text admin password authentication.
    AUTH_PASSWORD = 1;
}

// File system user credentials for executing an operation.
// Might be ignored by some operations.
message UserCredentials {
    // Globally unique user ID (GUID).
    required string username = 1;
    // List of one or more globally unique group IDs (GGID).
    repeated string groups = 2;
}

// Admin password if AuthType AUTH_PASSWORD.
message AuthPassword {
    required string password = 1;
}

// RPC Authentication information.
message Auth {
    // Selected authentication type.
    required AuthType auth_type = 1;
    // Optional data, depends on auth_type selected.
    optional AuthPassword auth_passwd = 3;
    optional bytes auth_data = 2;
}

// Error types.
enum ErrorType {
    // Requested interface_id not implemented by server.
    INVALID_INTERFACE_ID = 1;
    // Requested procedure_id not implemented by serevr.
    INVALID_PROC_ID = 2;
    // Server cannot parse the RPC request.
    GARBAGE_ARGS = 3;
    // Authentication failed, access denied.
    AUTH_FAILED = 4;
    // Unspecific internal server error that caused the RPC to fail.
    INTERNAL_SERVER_ERROR = 5;
    // POSIX errno error (not necessarily a failure), e.g. ENOENT.
    // POSIXErrno contains details that can be passed to an application.
    ERRNO = 6;
    // Server redirects to another server implementing the same interface.
    REDIRECT = 7;
    // Request failed, due to an invalid view (i.e. an outdated xlocset).
    INVALID_VIEW = 8;
    // Generic IO_ERROR to be used by the RPC implementation.
    IO_ERROR = 100;
}

// Additional error code which can be passed to applications.
// See errno.h for details. Values are equivalent to Linux
// values, but are different for other unix platforms such as
// Mac OS X and Solaris!
enum POSIXErrno {
  POSIX_ERROR_NONE = 9999;
  POSIX_ERROR_EPERM = 1;
  POSIX_ERROR_ENOENT = 2;
  POSIX_ERROR_EINTR = 4;
  POSIX_ERROR_EIO = 5;
  POSIX_ERROR_EAGAIN = 11;
  POSIX_ERROR_EACCES = 13;
  POSIX_ERROR_EEXIST = 17;
  POSIX_ERROR_EXDEV = 18;
  POSIX_ERROR_ENODEV = 19;
  POSIX_ERROR_ENOTDIR = 20;
  POSIX_ERROR_EISDIR = 21;
  POSIX_ERROR_EINVAL = 22;
  POSIX_ERROR_ENOSPC = 28;
  POSIX_ERROR_ENOTEMPTY = 39;
  POSIX_ERROR_ENODATA = 61;
} 

// RPC header message sent in the first request fragment.
message RPCHeader {

  // Header data for requests, i.e. message_type is RPC_REQUEST.
  message RequestHeader {
    // Interface id of the requested method.
    required fixed32 interface_id = 1;
    // Procedure id of the requested method.
    required fixed32 proc_id = 2;
    // File system user credentials for the operation.
    required UserCredentials user_creds = 3;
    // Authentication details.
    required Auth auth_data = 4;
  }

  // Header data for error responses, i.e. message_type is RPC_ERROR_RESPONSE.
  message ErrorResponse {
    // Error type details.
    required ErrorType error_type = 1;
    // Optional POSIX errno.
    optional POSIXErrno posix_errno = 2 [default = POSIX_ERROR_NONE];
    // Optional human readable error message in English (not localized!).
    optional string error_message = 3;
    // Optional debug information that only makes sense to developers such
    // as stack traces.
    optional string debug_info = 4;
    // Optional UUID of the server to use instead. Required when error_type is REDIRECT.
    optional string redirect_to_server_uuid = 5;
  }

  // A unique id to identify the request. The response sent back by the server will have
  // the same call_id.
  // The call_id must be unqiue per TCP connection. In addition, clients should start
  // with a value based e.g. on time to avoid problems after a client restart.
  required fixed32       call_id = 1;
  // Type of this RPC message (Request, Response).
  required MessageType   message_type = 2;

  // Optional request_header, required if message_type is RPC_REQUEST.
  optional RequestHeader request_header = 3;
  // Optional error_response, required if message_type is RPC_ERROR_RESPONSE.
  optional ErrorResponse error_response = 4;
}