/**
* mds — A micro-display server
* Copyright © 2014 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-kkbd.h"
#include <libmdsserver/macros.h>
#include <libmdsserver/util.h>
#include <libmdsserver/mds-message.h>
#include <inttypes.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/kd.h>
#include <pthread.h>
#define reconnect_to_display() -1 /* TODO */
#ifdef __sparc__
# define GET_LED KIOCGLED
# define SET_LED KIOCSLED
#else
# define GET_LED KDGETLED
# define SET_LED KDSETLED
#endif
#ifdef __sparc__
# define LED_NUM_LOCK 1
# define LED_CAPS_LOCK 8
# define LED_SCRL_LOCK 4
# define LED_COMPOSE 2
#else
# define LED_NUM_LOCK LED_NUM
# define LED_CAPS_LOCK LED_CAP
# define LED_SCRL_LOCK LED_SCR
#endif
#define MDS_KKBD_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 = 0,
.require_display = 1,
.require_respawn_info = 0,
.sanity_check_argc = 1,
.fork_for_safety = 1
};
/**
* Value of the ‘Message ID’ header for the next message
*/
static int32_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;
/**
* File descriptor for accessing the keyboard LED:s
*/
static int ledfd = 0;
/**
* Saved LED states
*/
static int saved_leds;
/**
* Saved TTY settings
*/
static struct termios saved_stty;
/**
* Save keyboard mode
*/
static int saved_kbd_mode;
/**
* Keycode remapping table
*/
static int* restrict mapping = NULL;
/**
* The size of `mapping`
*/
static size_t mapping_size = 0;
/**
* Scancode buffer
*/
static int scancode_buf[3] = { 0, 0, 0 };
/**
* The number of elements stored in `scancode_buf`
*/
static int scancode_ptr = 0;
/**
* Message buffer for `send_key`
*/
static char* key_send_buffer = NULL;
/**
* The keyboard listener thread
*/
static pthread_t kbd_thread;
/**
* Whether `kbd_thread` has started
*/
static int kbd_thread_started = 0;
/**
* 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;
const char* const message =
"Command: intercept\n"
"Message ID: 0\n"
"Length: 18\n"
"\n"
"Command: keyboard\n";
if (full_send(message, strlen(message)))
return 1;
open_leds();
stage = 1;
open_input();
stage = 2;
fail_if (server_initialised());
stage = 0;
fail_if (mds_message_initialise(&received));
fail_if (xmalloc(key_send_buffer, 111, char));
return 0;
pfail:
xperror(*argv);
if (stage >= 2) close_input();
if (stage >= 1) close_leds();
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;
if (reconnect_to_display())
{
mds_message_destroy(&received);
return 1;
}
connected = 1;
return 0;
}
/**
* This function is called by the parent server process when the
* child server process exits, if the server has completed its
* initialisation
*
* @param status The status the child died with
*/
void fork_cleanup(int status)
{
(void) status;
close_input();
close_leds();
}
/**
* 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 = 9 * sizeof(int) + sizeof(int32_t) + sizeof(struct termios);
rc += sizeof(size_t) + mapping_size * sizeof(int);
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_KKBD_VARS_VERSION);
buf_set_next(state_buf, int, connected);
buf_set_next(state_buf, int32_t, message_id);
buf_set_next(state_buf, int, ledfd);
buf_set_next(state_buf, int, saved_leds);
buf_set_next(state_buf, struct termios, saved_stty);
buf_set_next(state_buf, int, saved_kbd_mode);
buf_set_next(state_buf, int, scancode_ptr);
buf_set_next(state_buf, int, scancode_buf[0]);
buf_set_next(state_buf, int, scancode_buf[1]);
buf_set_next(state_buf, int, scancode_buf[2]);
buf_set_next(state_buf, size_t, mapping_size);
if (mapping_size > 0)
{
memcpy(state_buf, mapping, mapping_size * sizeof(int));
state_buf += mapping_size * sizeof(int) / sizeof(char);
}
mds_message_marshal(&received, state_buf);
mds_message_destroy(&received);
free(mapping);
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_KKBDOARD_VARS_VERSION); */
buf_next(state_buf, int, 1);
buf_get_next(state_buf, int, connected);
buf_get_next(state_buf, int32_t, message_id);
buf_get_next(state_buf, int, ledfd);
buf_get_next(state_buf, int, saved_leds);
buf_get_next(state_buf, struct termios, saved_stty);
buf_get_next(state_buf, int, saved_kbd_mode);
buf_get_next(state_buf, int, scancode_ptr);
buf_get_next(state_buf, int, scancode_buf[0]);
buf_get_next(state_buf, int, scancode_buf[1]);
buf_get_next(state_buf, int, scancode_buf[2]);
buf_get_next(state_buf, size_t, mapping_size);
if (mapping_size > 0)
{
fail_if (xmalloc(mapping, mapping_size, int));
memcpy(mapping, state_buf, mapping_size * sizeof(int));
state_buf += mapping_size * sizeof(int) / sizeof(char);
}
fail_if (mds_message_unmarshal(&received, state_buf));
return 0;
pfail:
xperror(*argv);
mds_message_destroy(&received);
free(mapping);
abort(); /* We must abort on failure to not risk the keyboard
getting stuck and freeze up the computer until
someone ssh:es into it and kill the server. */
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;
}
/**
* Perform the server's mission
*
* @return Non-zero on error
*/
int master_loop(void)
{
int rc = 1, joined = 0;
void* kbd_ret;
fail_if ((errno = pthread_create(&kbd_thread, NULL, keyboard_loop, NULL)));
while (!reexecing && !terminating)
{
int r = mds_message_read(&received, socket_fd);
if (r == 0)
{
if (r = 0, r == 0) /* TODO handle_message() */
continue;
}
if (r == -2)
{
eprint("corrupt message received, aborting.");
goto fail;
}
else if (errno == EINTR)
continue;
else if (errno != ECONNRESET)
goto pfail;
eprint("lost connection to server.");
mds_message_destroy(&received);
mds_message_initialise(&received);
connected = 0;
if (reconnect_to_display())
goto fail;
connected = 1;
}
joined = 1;
fail_if ((errno = pthread_join(kbd_thread, &kbd_ret)));
rc = kbd_ret == NULL ? 0 : 1;
goto fail;
pfail:
xperror(*argv);
fail:
if (!rc && reexecing)
return 0;
if ((!joined) && (errno = pthread_join(kbd_thread, NULL)))
xperror(*argv);
mds_message_destroy(&received);
return rc;
}
/**
* The keyboard listener thread's main function
*
* @param data Input data
* @return Output data
*/
void* keyboard_loop(void* data)
{
(void) data;
kbd_thread_started = 1;
while (!reexecing && !terminating)
if (fetch_keys() < 0)
if (errno != EINTR)
goto pfail;
free(mapping);
return NULL;
pfail:
xperror(*argv);
free(mapping);
raise(SIGTERM);
return (void*)1024;
}
/**
* Send a singal to all threads except the current thread
*
* @param signo The signal
*/
void signal_all(int signo)
{
pthread_t current_thread = pthread_self();
if (pthread_equal(current_thread, master_thread) == 0)
pthread_kill(master_thread, signo);
if (kbd_thread_started)
if (pthread_equal(current_thread, kbd_thread) == 0)
pthread_kill(kbd_thread, signo);
}
/**
* Send a full message even if interrupted
*
* @param message The message to send
* @param length The length of the message
* @return Non-zero on success
*/
int full_send(const char* message, size_t length)
{
size_t sent;
while (length > 0)
{
sent = send_message(socket_fd, message, length);
if (sent > length)
{
eprint("Sent more of a message than exists in the message, aborting.");
return -1;
}
else if ((sent < length) && (errno != EINTR))
{
xperror(*argv);
return -1;
}
message += sent;
length -= sent;
}
return 0;
}
/**
* Acquire access of the keyboard's LED:s
*
* @return Zero on success, -1 on error
*/
int open_leds(void)
{
#ifdef __sparc__
if ((ledfd = open(SPARC_KBD, O_RDONLY)) < 0)
return -1;
if (ioctl(ledfd, GET_LED, &saved_leds) < 0)
{
close(ledfd);
return -1;
}
return 0;
#else
return ioctl(ledfd, GET_LED, &saved_leds);
#endif
}
/**
* Release access of the keyboard's LED:s
*/
void close_leds(void)
{
if (ioctl(ledfd, SET_LED, saved_leds) < 0)
xperror(*argv);
#ifdef __sparc__
close(ledfd);
#endif
}
/**
* Get active LED:s on the keyboard
*
* @return Active LED:s, -1 on error
*/
int get_leds(void)
{
int leds;
if (ioctl(ledfd, GET_LED, &leds) < 0)
return -1;
#ifdef __sparc__
leds &= 15;
#endif
return leds;
}
/**
* Set active LED:s on the keyboard
*
* @param leds Active LED:s
* @return Zero on success, -1 on error
*/
int set_leds(int leds)
{
return ioctl(ledfd, SET_LED, leds);
}
/**
* Acquire access of keyboard input
*
* @return Zero on success, -1 on error
*/
int open_input(void)
{
struct termios stty;
if (tcgetattr(STDIN_FILENO, &saved_stty) < 0)
return -1;
stty = saved_stty;
stty.c_lflag &= (tcflag_t)~(ECHO | ICANON | ISIG);
stty.c_iflag = 0;
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty) < 0)
return -1;
/* K_MEDIUMRAW: utilise keyboard drivers, but not layout */
if ((ioctl(STDIN_FILENO, KDGKBMODE, &saved_kbd_mode) < 0) ||
(ioctl(STDIN_FILENO, KDSKBMODE, K_MEDIUMRAW) < 0))
{
xperror(*argv);
return tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty);
}
return 0;
}
/**
* Release access of keyboard input
*/
void close_input(void)
{
if (ioctl(STDIN_FILENO, KDSKBMODE, saved_kbd_mode) < 0)
xperror(*argv);
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty) < 0)
xperror(*argv);
}
/**
* Broadcast a keyboard input event
*
* @param scancode The scancode
* @param trio Whether the scancode has three integers rather than one
* @return Zero on success, -1 on error
*/
int send_key(int* restrict scancode, int trio)
{
int keycode, released = (scancode[0] & 0x80) == 0x80;
scancode[0] &= 0x7F;
if (trio)
{
keycode = (scancode[1] &= 0x7F) << 7;
keycode |= (scancode[2] &= 0x7F);
}
else
keycode = scancode[0];
if ((size_t)keycode < mapping_size)
keycode = mapping[keycode];
if (trio)
sprintf(key_send_buffer,
"Command: key-sent\n"
"Scancode: %i %i %i\n"
"Keycode: %i\n"
"Released: %s\n"
"Keyboard: kernel\n"
"Message ID: " PRIi32 "\n"
"\n",
scancode[0], scancode[1], scancode[2], keycode,
released ? "yes" : "no", message_id);
else
sprintf(key_send_buffer,
"Command: key-sent\n"
"Scancode: %i\n"
"Keycode: %i\n"
"Released: %s\n"
"Keyboard: kernel\n"
"Message ID: " PRIi32 "\n"
"\n",
scancode[0], keycode,
released ? "yes" : "no", message_id);
message_id = message_id == INT32_MAX ? 0 : (message_id + 1);
return full_send(key_send_buffer, strlen(key_send_buffer));
}
/**
* Fetch and broadcast keys until interrupted
*
* @return Zero on success, -1 on error
*/
int fetch_keys(void)
{
#ifdef DEBUG
int consecutive_escapes = 0;
#endif
int c;
ssize_t r;
for (;;)
{
r = read(STDIN_FILENO, &c, sizeof(int));
if (r <= 0)
{
if (r == 0)
{
raise(SIGTERM);
errno = 0;
}
break;
}
#ifdef DEBUG
if ((c & 0x7F) == 1) /* Exit with ESCAPE, ESCAPE, ESCAPE */
{
if (++consecutive_escapes >= 2 * 3)
{
raise(SIGTERM);
errno = 0;
break;
}
}
else
consecutive_escapes = 0;
#endif
redo:
scancode_buf[scancode_ptr] = c;
if (scancode_ptr == 0)
{
if ((c & 0x7F) == 0)
scancode_ptr++;
else
send_key(scancode_buf, 0);
}
else if (scancode_ptr == 1)
{
if ((c & 0x80) == 0)
{
scancode_ptr = 0;
goto redo;
}
scancode_ptr++;
}
else
{
scancode_ptr = 0;
if ((c & 0x80) == 0)
{
send_key(scancode_buf + 1, 0);
goto redo;
}
send_key(scancode_buf, 1);
}
}
return errno == 0 ? 0 : -1;
}
