LXR busybox/console-tools/dumpkmap.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Mini dumpkmap implementation for busybox
   4 *
   5 * Copyright (C) Arne Bernin <arne@matrix.loopback.org>
   6 *
   7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8 */
   9//config:config DUMPKMAP
  10//config:       bool "dumpkmap (1.6 kb)"
  11//config:       default y
  12//config:       help
  13//config:       This program dumps the kernel's keyboard translation table to
  14//config:       stdout, in binary format. You can then use loadkmap to load it.
  15
  16//applet:IF_DUMPKMAP(APPLET_NOEXEC(dumpkmap, dumpkmap, BB_DIR_BIN, BB_SUID_DROP, dumpkmap))
  17/* bb_common_bufsiz1 usage here is safe wrt NOEXEC: not expecting it to be zeroed. */
  18
  19//kbuild:lib-$(CONFIG_DUMPKMAP) += dumpkmap.o
  20
  21//usage:#define dumpkmap_trivial_usage
  22//usage:       "> keymap"
  23//usage:#define dumpkmap_full_usage "\n\n"
  24//usage:       "Print a binary keyboard translation table to stdout"
  25//usage:
  26//usage:#define dumpkmap_example_usage
  27//usage:       "$ dumpkmap > keymap\n"
  28
  29#include "libbb.h"
  30#include "common_bufsiz.h"
  31
  32/* From <linux/kd.h> */
  33struct kbentry {
  34        unsigned char kb_table;
  35        unsigned char kb_index;
  36        unsigned short kb_value;
  37};
  38#define KDGKBENT 0x4B46  /* gets one entry in translation table */
  39
  40/* From <linux/keyboard.h> */
  41#define NR_KEYS 128
  42#define MAX_NR_KEYMAPS 256
  43
  44int dumpkmap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  45int dumpkmap_main(int argc UNUSED_PARAM, char **argv)
  46{
  47        struct kbentry ke;
  48        int i, j, fd;
  49
  50        /* When user accidentally runs "dumpkmap FILE"
  51         * instead of "dumpkmap >FILE", we'd dump binary stuff to tty.
  52         * Let's prevent it:
  53         */
  54        if (argv[1])
  55                bb_show_usage();
  56/*      bb_warn_ignoring_args(argv[1]);*/
  57
  58        fd = get_console_fd_or_die();
  59
  60#define flags bb_common_bufsiz1
  61        setup_common_bufsiz();
  62        /*                     0 1 2 3 4 5 6 7 8 9 a b c=12 */
  63        memcpy(flags, "bkeymap\1\1\1\0\1\1\1\0\1\1\1\0\1",
  64        /* Can use sizeof, or sizeof-1. sizeof is even, using that */
  65        /****/ sizeof("bkeymap\1\1\1\0\1\1\1\0\1\1\1\0\1")
  66        );
  67        write(STDOUT_FILENO, flags, 7 + MAX_NR_KEYMAPS);
  68#define flags7 (flags + 7)
  69
  70        for (i = 0; i < 13; i++) {
  71                if (flags7[i]) {
  72                        for (j = 0; j < NR_KEYS; j++) {
  73                                ke.kb_index = j;
  74                                ke.kb_table = i;
  75                                if (!ioctl_or_perror(fd, KDGKBENT, &ke,
  76                                                "ioctl(KDGKBENT{%d,%d}) failed",
  77                                                j, i)
  78                                ) {
  79                                        write(STDOUT_FILENO, &ke.kb_value, 2);
  80                                }
  81                        }
  82                }
  83        }
  84        if (ENABLE_FEATURE_CLEAN_UP) {
  85                close(fd);
  86        }
  87        return EXIT_SUCCESS;
  88}
  89