drivers/s390/char/keyboard.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    ebcdic keycode functions for s390 console drivers
   4  *
   5  *  S390 version
   6  *    Copyright IBM Corp. 2003
   7  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/sched/signal.h>
  12 #include <linux/slab.h>
  13 #include <linux/sysrq.h>
  14
  15 #include <linux/consolemap.h>
  16 #include <linux/kbd_kern.h>
  17 #include <linux/kbd_diacr.h>
  18 #include <linux/uaccess.h>
  19
  20 #include "keyboard.h"
  21
  22 /*
  23  * Handler Tables.
  24  */
  25 #define K_HANDLERS\
  26         k_self,         k_fn,           k_spec,         k_ignore,\
  27         k_dead,         k_ignore,       k_ignore,       k_ignore,\
  28         k_ignore,       k_ignore,       k_ignore,       k_ignore,\
  29         k_ignore,       k_ignore,       k_ignore,       k_ignore
  30
  31 typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
  32 static k_handler_fn K_HANDLERS;
  33 static k_handler_fn *k_handler[16] = { K_HANDLERS };
  34
  35 /* maximum values each key_handler can handle */
  36 static const int kbd_max_vals[] = {
  37         255, ARRAY_SIZE(func_table) - 1, NR_FN_HANDLER - 1, 0,
  38         NR_DEAD - 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
  39 };
  40 static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);
  41
  42 static unsigned char ret_diacr[NR_DEAD] = {
  43         '`', '\'', '^', '~', '"', ','
  44 };
  45
  46 /*
  47  * Alloc/free of kbd_data structures.
  48  */
  49 struct kbd_data *
  50 kbd_alloc(void) {
  51         struct kbd_data *kbd;
  52         int i;
  53
  54         kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
  55         if (!kbd)
  56                 goto out;
  57         kbd->key_maps = kzalloc(sizeof(key_maps), GFP_KERNEL);
  58         if (!kbd->key_maps)
  59                 goto out_kbd;
  60         for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
  61                 if (key_maps[i]) {
  62                         kbd->key_maps[i] = kmemdup(key_maps[i],
  63                                                    sizeof(u_short) * NR_KEYS,
  64                                                    GFP_KERNEL);
  65                         if (!kbd->key_maps[i])
  66                                 goto out_maps;
  67                 }
  68         }
  69         kbd->func_table = kzalloc(sizeof(func_table), GFP_KERNEL);
  70         if (!kbd->func_table)
  71                 goto out_maps;
  72         for (i = 0; i < ARRAY_SIZE(func_table); i++) {
  73                 if (func_table[i]) {
  74                         kbd->func_table[i] = kstrdup(func_table[i],
  75                                                      GFP_KERNEL);
  76                         if (!kbd->func_table[i])
  77                                 goto out_func;
  78                 }
  79         }
  80         kbd->fn_handler =
  81                 kzalloc(sizeof(fn_handler_fn *) * NR_FN_HANDLER, GFP_KERNEL);
  82         if (!kbd->fn_handler)
  83                 goto out_func;
  84         kbd->accent_table = kmemdup(accent_table,
  85                                     sizeof(struct kbdiacruc) * MAX_DIACR,
  86                                     GFP_KERNEL);
  87         if (!kbd->accent_table)
  88                 goto out_fn_handler;
  89         kbd->accent_table_size = accent_table_size;
  90         return kbd;
  91
  92 out_fn_handler:
  93         kfree(kbd->fn_handler);
  94 out_func:
  95         for (i = 0; i < ARRAY_SIZE(func_table); i++)
  96                 kfree(kbd->func_table[i]);
  97         kfree(kbd->func_table);
  98 out_maps:
  99         for (i = 0; i < ARRAY_SIZE(key_maps); i++)
 100                 kfree(kbd->key_maps[i]);
 101         kfree(kbd->key_maps);
 102 out_kbd:
 103         kfree(kbd);
 104 out:
 105         return NULL;
 106 }
 107
 108 void
 109 kbd_free(struct kbd_data *kbd)
 110 {
 111         int i;
 112
 113         kfree(kbd->accent_table);
 114         kfree(kbd->fn_handler);
 115         for (i = 0; i < ARRAY_SIZE(func_table); i++)
 116                 kfree(kbd->func_table[i]);
 117         kfree(kbd->func_table);
 118         for (i = 0; i < ARRAY_SIZE(key_maps); i++)
 119                 kfree(kbd->key_maps[i]);
 120         kfree(kbd->key_maps);
 121         kfree(kbd);
 122 }
 123
 124 /*
 125  * Generate ascii -> ebcdic translation table from kbd_data.
 126  */
 127 void
 128 kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
 129 {
 130         unsigned short *keymap, keysym;
 131         int i, j, k;
 132
 133         memset(ascebc, 0x40, 256);
 134         for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
 135                 keymap = kbd->key_maps[i];
 136                 if (!keymap)
 137                         continue;
 138                 for (j = 0; j < NR_KEYS; j++) {
 139                         k = ((i & 1) << 7) + j;
 140                         keysym = keymap[j];
 141                         if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
 142                             KTYP(keysym) == (KT_LETTER | 0xf0))
 143                                 ascebc[KVAL(keysym)] = k;
 144                         else if (KTYP(keysym) == (KT_DEAD | 0xf0))
 145                                 ascebc[ret_diacr[KVAL(keysym)]] = k;
 146                 }
 147         }
 148 }
 149
 150 #if 0
 151 /*
 152  * Generate ebcdic -> ascii translation table from kbd_data.
 153  */
 154 void
 155 kbd_ebcasc(struct kbd_data *kbd, unsigned char *ebcasc)
 156 {
 157         unsigned short *keymap, keysym;
 158         int i, j, k;
 159
 160         memset(ebcasc, ' ', 256);
 161         for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
 162                 keymap = kbd->key_maps[i];
 163                 if (!keymap)
 164                         continue;
 165                 for (j = 0; j < NR_KEYS; j++) {
 166                         keysym = keymap[j];
 167                         k = ((i & 1) << 7) + j;
 168                         if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
 169                             KTYP(keysym) == (KT_LETTER | 0xf0))
 170                                 ebcasc[k] = KVAL(keysym);
 171                         else if (KTYP(keysym) == (KT_DEAD | 0xf0))
 172                                 ebcasc[k] = ret_diacr[KVAL(keysym)];
 173                 }
 174         }
 175 }
 176 #endif
 177
 178 /*
 179  * We have a combining character DIACR here, followed by the character CH.
 180  * If the combination occurs in the table, return the corresponding value.
 181  * Otherwise, if CH is a space or equals DIACR, return DIACR.
 182  * Otherwise, conclude that DIACR was not combining after all,
 183  * queue it and return CH.
 184  */
 185 static unsigned int
 186 handle_diacr(struct kbd_data *kbd, unsigned int ch)
 187 {
 188         int i, d;
 189
 190         d = kbd->diacr;
 191         kbd->diacr = 0;
 192
 193         for (i = 0; i < kbd->accent_table_size; i++) {
 194                 if (kbd->accent_table[i].diacr == d &&
 195                     kbd->accent_table[i].base == ch)
 196                         return kbd->accent_table[i].result;
 197         }
 198
 199         if (ch == ' ' || ch == d)
 200                 return d;
 201
 202         kbd_put_queue(kbd->port, d);
 203         return ch;
 204 }
 205
 206 /*
 207  * Handle dead key.
 208  */
 209 static void
 210 k_dead(struct kbd_data *kbd, unsigned char value)
 211 {
 212         value = ret_diacr[value];
 213         kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
 214 }
 215
 216 /*
 217  * Normal character handler.
 218  */
 219 static void
 220 k_self(struct kbd_data *kbd, unsigned char value)
 221 {
 222         if (kbd->diacr)
 223                 value = handle_diacr(kbd, value);
 224         kbd_put_queue(kbd->port, value);
 225 }
 226
 227 /*
 228  * Special key handlers
 229  */
 230 static void
 231 k_ignore(struct kbd_data *kbd, unsigned char value)
 232 {
 233 }
 234
 235 /*
 236  * Function key handler.
 237  */
 238 static void
 239 k_fn(struct kbd_data *kbd, unsigned char value)
 240 {
 241         if (kbd->func_table[value])
 242                 kbd_puts_queue(kbd->port, kbd->func_table[value]);
 243 }
 244
 245 static void
 246 k_spec(struct kbd_data *kbd, unsigned char value)
 247 {
 248         if (value >= NR_FN_HANDLER)
 249                 return;
 250         if (kbd->fn_handler[value])
 251                 kbd->fn_handler[value](kbd);
 252 }
 253
 254 /*
 255  * Put utf8 character to tty flip buffer.
 256  * UTF-8 is defined for words of up to 31 bits,
 257  * but we need only 16 bits here
 258  */
 259 static void
 260 to_utf8(struct tty_port *port, ushort c)
 261 {
 262         if (c < 0x80)
 263                 /*  0******* */
 264                 kbd_put_queue(port, c);
 265         else if (c < 0x800) {
 266                 /* 110***** 10****** */
 267                 kbd_put_queue(port, 0xc0 | (c >> 6));
 268                 kbd_put_queue(port, 0x80 | (c & 0x3f));
 269         } else {
 270                 /* 1110**** 10****** 10****** */
 271                 kbd_put_queue(port, 0xe0 | (c >> 12));
 272                 kbd_put_queue(port, 0x80 | ((c >> 6) & 0x3f));
 273                 kbd_put_queue(port, 0x80 | (c & 0x3f));
 274         }
 275 }
 276
 277 /*
 278  * Process keycode.
 279  */
 280 void
 281 kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
 282 {
 283         unsigned short keysym;
 284         unsigned char type, value;
 285
 286         if (!kbd)
 287                 return;
 288
 289         if (keycode >= 384)
 290                 keysym = kbd->key_maps[5][keycode - 384];
 291         else if (keycode >= 256)
 292                 keysym = kbd->key_maps[4][keycode - 256];
 293         else if (keycode >= 128)
 294                 keysym = kbd->key_maps[1][keycode - 128];
 295         else
 296                 keysym = kbd->key_maps[0][keycode];
 297
 298         type = KTYP(keysym);
 299         if (type >= 0xf0) {
 300                 type -= 0xf0;
 301                 if (type == KT_LETTER)
 302                         type = KT_LATIN;
 303                 value = KVAL(keysym);
 304 #ifdef CONFIG_MAGIC_SYSRQ              /* Handle the SysRq Hack */
 305                 if (kbd->sysrq) {
 306                         if (kbd->sysrq == K(KT_LATIN, '-')) {
 307                                 kbd->sysrq = 0;
 308                                 handle_sysrq(value);
 309                                 return;
 310                         }
 311                         if (value == '-') {
 312                                 kbd->sysrq = K(KT_LATIN, '-');
 313                                 return;
 314                         }
 315                         /* Incomplete sysrq sequence. */
 316                         (*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
 317                         kbd->sysrq = 0;
 318                 } else if ((type == KT_LATIN && value == '^') ||
 319                            (type == KT_DEAD && ret_diacr[value] == '^')) {
 320                         kbd->sysrq = K(type, value);
 321                         return;
 322                 }
 323 #endif
 324                 (*k_handler[type])(kbd, value);
 325         } else
 326                 to_utf8(kbd->port, keysym);
 327 }
 328
 329 /*
 330  * Ioctl stuff.
 331  */
 332 static int
 333 do_kdsk_ioctl(struct kbd_data *kbd, struct kbentry __user *user_kbe,
 334               int cmd, int perm)
 335 {
 336         struct kbentry tmp;
 337         ushort *key_map, val, ov;
 338
 339         if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
 340                 return -EFAULT;
 341 #if NR_KEYS < 256
 342         if (tmp.kb_index >= NR_KEYS)
 343                 return -EINVAL;
 344 #endif
 345 #if MAX_NR_KEYMAPS < 256
 346         if (tmp.kb_table >= MAX_NR_KEYMAPS)
 347                 return -EINVAL;
 348 #endif
 349
 350         switch (cmd) {
 351         case KDGKBENT:
 352                 key_map = kbd->key_maps[tmp.kb_table];
 353                 if (key_map) {
 354                     val = U(key_map[tmp.kb_index]);
 355                     if (KTYP(val) >= KBD_NR_TYPES)
 356                         val = K_HOLE;
 357                 } else
 358                     val = (tmp.kb_index ? K_HOLE : K_NOSUCHMAP);
 359                 return put_user(val, &user_kbe->kb_value);
 360         case KDSKBENT:
 361                 if (!perm)
 362                         return -EPERM;
 363                 if (!tmp.kb_index && tmp.kb_value == K_NOSUCHMAP) {
 364                         /* disallocate map */
 365                         key_map = kbd->key_maps[tmp.kb_table];
 366                         if (key_map) {
 367                             kbd->key_maps[tmp.kb_table] = NULL;
 368                             kfree(key_map);
 369                         }
 370                         break;
 371                 }
 372
 373                 if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
 374                         return -EINVAL;
 375                 if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
 376                         return -EINVAL;
 377
 378                 if (!(key_map = kbd->key_maps[tmp.kb_table])) {
 379                         int j;
 380
 381                         key_map = kmalloc(sizeof(plain_map),
 382                                                      GFP_KERNEL);
 383                         if (!key_map)
 384                                 return -ENOMEM;
 385                         kbd->key_maps[tmp.kb_table] = key_map;
 386                         for (j = 0; j < NR_KEYS; j++)
 387                                 key_map[j] = U(K_HOLE);
 388                 }
 389                 ov = U(key_map[tmp.kb_index]);
 390                 if (tmp.kb_value == ov)
 391                         break;  /* nothing to do */
 392                 /*
 393                  * Attention Key.
 394                  */
 395                 if (((ov == K_SAK) || (tmp.kb_value == K_SAK)) &&
 396                     !capable(CAP_SYS_ADMIN))
 397                         return -EPERM;
 398                 key_map[tmp.kb_index] = U(tmp.kb_value);
 399                 break;
 400         }
 401         return 0;
 402 }
 403
 404 static int
 405 do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
 406                int cmd, int perm)
 407 {
 408         unsigned char kb_func;
 409         char *p;
 410         int len;
 411
 412         /* Get u_kbs->kb_func. */
 413         if (get_user(kb_func, &u_kbs->kb_func))
 414                 return -EFAULT;
 415 #if MAX_NR_FUNC < 256
 416         if (kb_func >= MAX_NR_FUNC)
 417                 return -EINVAL;
 418 #endif
 419
 420         switch (cmd) {
 421         case KDGKBSENT:
 422                 p = kbd->func_table[kb_func];
 423                 if (p) {
 424                         len = strlen(p);
 425                         if (len >= sizeof(u_kbs->kb_string))
 426                                 len = sizeof(u_kbs->kb_string) - 1;
 427                         if (copy_to_user(u_kbs->kb_string, p, len))
 428                                 return -EFAULT;
 429                 } else
 430                         len = 0;
 431                 if (put_user('\0', u_kbs->kb_string + len))
 432                         return -EFAULT;
 433                 break;
 434         case KDSKBSENT:
 435                 if (!perm)
 436                         return -EPERM;
 437                 p = strndup_user(u_kbs->kb_string, sizeof(u_kbs->kb_string));
 438                 if (IS_ERR(p))
 439                         return PTR_ERR(p);
 440                 kfree(kbd->func_table[kb_func]);
 441                 kbd->func_table[kb_func] = p;
 442                 break;
 443         }
 444         return 0;
 445 }
 446
 447 int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
 448 {
 449         struct tty_struct *tty;
 450         void __user *argp;
 451         unsigned int ct;
 452         int perm;
 453
 454         argp = (void __user *)arg;
 455
 456         /*
 457          * To have permissions to do most of the vt ioctls, we either have
 458          * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 459          */
 460         tty = tty_port_tty_get(kbd->port);
 461         /* FIXME this test is pretty racy */
 462         perm = current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG);
 463         tty_kref_put(tty);
 464         switch (cmd) {
 465         case KDGKBTYPE:
 466                 return put_user(KB_101, (char __user *)argp);
 467         case KDGKBENT:
 468         case KDSKBENT:
 469                 return do_kdsk_ioctl(kbd, argp, cmd, perm);
 470         case KDGKBSENT:
 471         case KDSKBSENT:
 472                 return do_kdgkb_ioctl(kbd, argp, cmd, perm);
 473         case KDGKBDIACR:
 474         {
 475                 struct kbdiacrs __user *a = argp;
 476                 struct kbdiacr diacr;
 477                 int i;
 478
 479                 if (put_user(kbd->accent_table_size, &a->kb_cnt))
 480                         return -EFAULT;
 481                 for (i = 0; i < kbd->accent_table_size; i++) {
 482                         diacr.diacr = kbd->accent_table[i].diacr;
 483                         diacr.base = kbd->accent_table[i].base;
 484                         diacr.result = kbd->accent_table[i].result;
 485                         if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
 486                         return -EFAULT;
 487                 }
 488                 return 0;
 489         }
 490         case KDGKBDIACRUC:
 491         {
 492                 struct kbdiacrsuc __user *a = argp;
 493
 494                 ct = kbd->accent_table_size;
 495                 if (put_user(ct, &a->kb_cnt))
 496                         return -EFAULT;
 497                 if (copy_to_user(a->kbdiacruc, kbd->accent_table,
 498                                  ct * sizeof(struct kbdiacruc)))
 499                         return -EFAULT;
 500                 return 0;
 501         }
 502         case KDSKBDIACR:
 503         {
 504                 struct kbdiacrs __user *a = argp;
 505                 struct kbdiacr diacr;
 506                 int i;
 507
 508                 if (!perm)
 509                         return -EPERM;
 510                 if (get_user(ct, &a->kb_cnt))
 511                         return -EFAULT;
 512                 if (ct >= MAX_DIACR)
 513                         return -EINVAL;
 514                 kbd->accent_table_size = ct;
 515                 for (i = 0; i < ct; i++) {
 516                         if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
 517                                 return -EFAULT;
 518                         kbd->accent_table[i].diacr = diacr.diacr;
 519                         kbd->accent_table[i].base = diacr.base;
 520                         kbd->accent_table[i].result = diacr.result;
 521                 }
 522                 return 0;
 523         }
 524         case KDSKBDIACRUC:
 525         {
 526                 struct kbdiacrsuc __user *a = argp;
 527
 528                 if (!perm)
 529                         return -EPERM;
 530                 if (get_user(ct, &a->kb_cnt))
 531                         return -EFAULT;
 532                 if (ct >= MAX_DIACR)
 533                         return -EINVAL;
 534                 kbd->accent_table_size = ct;
 535                 if (copy_from_user(kbd->accent_table, a->kbdiacruc,
 536                                    ct * sizeof(struct kbdiacruc)))
 537                         return -EFAULT;
 538                 return 0;
 539         }
 540         default:
 541                 return -ENOIOCTLCMD;
 542         }
 543 }
 544
 545 EXPORT_SYMBOL(kbd_ioctl);
 546 EXPORT_SYMBOL(kbd_ascebc);
 547 EXPORT_SYMBOL(kbd_free);
 548 EXPORT_SYMBOL(kbd_alloc);
 549 EXPORT_SYMBOL(kbd_keycode);