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/**
* mds — A micro-display server
* Copyright © 2014, 2015 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/>.
*/
#ifndef MDS_MDS_VT_H
#define MDS_MDS_VT_H
#include "mds-base.h"
#include <sys/stat.h>
#include <linux/vt.h>
/**
* Wait for confirmation that we may switch virtual terminal
*
* @param data Thread input parameter, will always be `NULL`
* @return Thread return value, will always be `NULL`
*/
void* secondary_loop(void* data);
/**
* Perform a VT switch requested by the OS kernel
*
* @param leave_foreground Whether the display is leaving the foreground
* @return Zero on success, -1 on error
*/
int switch_vt(int leave_foreground);
/**
* Handle the received message
*
* @return Zero on success, -1 on error
*/
int handle_message(void);
/**
* Handle a received `Command: get-vt` message
*
* @param client The value of the header `Client ID` in the received message
* @param message The value of the header `Message ID` in the received message
* @return Zero on success, -1 on error
*/
int handle_get_vt(const char* client, const char* message);
/**
* Handle a received `Command: configure-vt` message
*
* @param client The value of the header `Client ID` in the received message
* @param message The value of the header `Message ID` in the received message
* @param graphical The value of the header `Graphical` in the received message
* @param exclusive The value of the header `Exclusive` in the received message
* @return Zero on success, -1 on error
*/
int handle_configure_vt(const char* client, const char* message, const char* graphical, const char* exclusive);
/**
* This function is called when the kernel wants
* to switch foreground virtual terminal
*
* @param signo The received signal number
*/
void received_switch_vt(int signo);
/**
* Send a full message even if interrupted
*
* @param socket The file descriptor for the socket to use
* @param message The message to send
* @param length The length of the message
* @return Zero on success, -1 on error
*/
int full_send(int socket, const char* message, size_t length);
/**
* Get the index of the virtual terminal on which the display should be opened
*
* @return The index of the virtual terminal on which the display should be opened, -1 on error
*/
int select_vt(void);
/**
* Get the index of the next available virtual terminal
*
* @return -1 on error, 0 if the terminals are exhausted, otherwise the next terminal
*/
int vt_get_next_available(void);
/**
* Get the currently active virtual terminal
*
* @return -1 on error, otherwise the current terminal
*/
int vt_get_active(void);
/**
* Change currently active virtual terminal and wait for it to complete the switch
*
* @param vt The index of the terminal
* @return Zero on success, -1 on error
*/
int vt_set_active(int vt);
/**
* Open a virtual terminal
*
* @param vt The index of the terminal
* @param old_stat Output parameter for the old file stat for the terminal
* @return The file descriptor for the terminal, -1 on error
*/
int vt_open(int vt, struct stat* restrict old_stat);
/**
* Close a virtual terminal
*
* @param vt The index of the terminal
* @param old_stat The old file stat for the terminal
*/
void vt_close(int fd, struct stat* restrict old_stat);
/**
* Block or stop blocking other programs to open the a terminal
*
* @param fd:int File descriptor for the terminal
* @param exclusive:int Whether to block other programs for using the terminal
* @return :int Zero on success, -1 on error
*/
#define vt_set_exclusive(fd, exclusive) \
(ioctl(fd, (exclusive) ? TIOCEXCL : TIOCNXCL))
/**
* Configure a terminal to be set to either graphical mode or text mode
*
* @param fd:int File descriptor for the terminal
* @param graphical:int Whether to use graphical mode
* @return :int Zero on success, -1 on error
*/
#define vt_set_graphical(fd, graphical) \
(ioctl(fd, KDSETMODE, (graphical) ? KD_GRAPHICS : KD_TEXT))
/**
* Construct a virtual terminal mode that can be used in `vt_get_set_mode`
*
* @param vt_switch_control Whether we want to be able to block and delay VT switches
* @param vt_leave_signal The signal that should be send to us we a process is trying
* to switch terminal to another terminal
* @param vt_enter_signal The signal that should be send to us we a process is trying
* to switch terminal to our terminal
* @param mode Output parameter
*/
void vt_construct_mode(int vt_switch_control, int vt_leave_signal,
int vt_enter_signal, struct vt_mode* restrict mode);
/**
* Set or get the mode for a virtual terminal
*
* @param fd:int File descriptor for the terminal
* @param set:int Whether to set the mode
* @param mode:struct vt_mode* Input or outpur parameter for the mode
* @return :int Zero on success, -1 on error
*/
#define vt_get_set_mode(fd, set, mode) \
(ioctl(fd, set ? VT_SETMODE : VT_GETMODE, mode))
/**
* Block or temporarily block virtual terminal switch
*
* @param fd:int File descriptor for our terminal
* @return :int Zero on success, -1 on error
*/
#define vt_stop_switch(fd) \
(ioctl(fd, VT_RELDISP, 0))
/**
* Allow a temporarily block virtual terminal switch to continue
*
* @param fd:int File descriptor for our terminal
* @return :int Zero on success, -1 on error
*/
#define vt_continue_switch(fd) \
(ioctl(fd, VT_RELDISP, 1))
/**
* Accept a virtual terminal switch
*
* @param fd:int File descriptor for our terminal
* @return :int Zero on success, -1 on error
*/
#define vt_accept_switch(fd) \
(ioctl(fd, VT_RELDISP, VT_ACKACQ))
#endif
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