/**
* mds — A micro-display server
* Copyright © 2014, 2015, 2016 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "mds-libinput.h"
/* TODO: This server should wait for `Command: get-vt` to be available,
query the active VT and connect to that TTY instead of stdin. */
#include <libmdsserver/macros.h>
#include <libmdsserver/util.h>
#include <libmdsserver/mds-message.h>
#include <inttypes.h>
#define reconnect_to_display() -1
#define MDS_LIBINPUT_VARS_VERSION 0
/**
* This variable should declared by the actual server implementation.
* It must be configured before `main` is invoked.
*
* This tells the server-base how to behave
*/
server_characteristics_t server_characteristics =
{
.require_privileges = 1,
.require_display = 1,
.require_respawn_info = 0,
.sanity_check_argc = 1,
.fork_for_safety = 0,
.danger_is_deadly = 0
};
/**
* Value of the ‘Message ID’ header for the next message
*/
static uint32_t message_id = 1;
/**
* Buffer for received messages
*/
static mds_message_t received;
/**
* Whether the server is connected to the display
*/
static int connected = 1;
/**
* Send a full message even if interrupted
*
* @param message:const char* The message to send
* @param length:size_t The length of the message
* @return :int Zero on success, -1 on error
*/
#define full_send(message, length) \
((full_send)(socket_fd, message, length))
/**
* This function will be invoked before `initialise_server` (if not re-exec:ing)
* or before `unmarshal_server` (if re-exec:ing)
*
* @return Non-zero on error
*/
int __attribute__((const)) preinitialise_server(void)
{
return 0;
}
/**
* This function should initialise the server,
* and it not invoked after a re-exec.
*
* @return Non-zero on error
*/
int initialise_server(void)
{
int stage = 0;
fail_if (server_initialised()); stage++;
fail_if (mds_message_initialise(&received));
return 0;
fail:
xperror(*argv);
if (stage >= 1) mds_message_destroy(&received);
return 1;
}
/**
* This function will be invoked after `initialise_server` (if not re-exec:ing)
* or after `unmarshal_server` (if re-exec:ing)
*
* @return Non-zero on error
*/
int postinitialise_server(void)
{
if (connected)
return 0;
fail_if (reconnect_to_display());
connected = 1;
return 0;
fail:
mds_message_destroy(&received);
return 1;
}
/**
* Calculate the number of bytes that will be stored by `marshal_server`
*
* On failure the program should `abort()` or exit by other means.
* However it should not be possible for this function to fail.
*
* @return The number of bytes that will be stored by `marshal_server`
*/
size_t marshal_server_size(void)
{
size_t rc = 2 * sizeof(int) + sizeof(uint32_t);
rc += mds_message_marshal_size(&received);
return rc;
}
/**
* Marshal server implementation specific data into a buffer
*
* @param state_buf The buffer for the marshalled data
* @return Non-zero on error
*/
int marshal_server(char* state_buf)
{
buf_set_next(state_buf, int, MDS_LIBINPUT_VARS_VERSION);
buf_set_next(state_buf, int, connected);
buf_set_next(state_buf, uint32_t, message_id);
mds_message_marshal(&received, state_buf);
mds_message_destroy(&received);
return 0;
}
/**
* Unmarshal server implementation specific data and update the servers state accordingly
*
* On critical failure the program should `abort()` or exit by other means.
* That is, do not let `reexec_failure_recover` run successfully, if it unrecoverable
* error has occurred or one severe enough that it is better to simply respawn.
*
* @param state_buf The marshalled data that as not been read already
* @return Non-zero on error
*/
int unmarshal_server(char* state_buf)
{
/* buf_get_next(state_buf, int, MDS_LIBINPUT_VARS_VERSION); */
buf_next(state_buf, int, 1);
buf_get_next(state_buf, int, connected);
buf_get_next(state_buf, uint32_t, message_id);
fail_if (mds_message_unmarshal(&received, state_buf));
return 0;
fail:
xperror(*argv);
mds_message_destroy(&received);
return -1;
}
/**
* Attempt to recover from a re-exec failure that has been
* detected after the server successfully updated it execution image
*
* @return Non-zero on error
*/
int __attribute__((const)) reexec_failure_recover(void)
{
return -1;
}
/**
* This function is called when a signal that
* signals that the system to dump state information
* and statistics has been received
*
* @param signo The signal that has been received
*/
void received_info(int signo)
{
SIGHANDLER_START;
(void) signo;
iprintf("next message ID: %" PRIu32, message_id);
iprintf("connected: %s", connected ? "yes" : "no");
SIGHANDLER_END;
}
