linux/drivers/s390/char/keyboard.c
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   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
  31typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
  32static k_handler_fn K_HANDLERS;
  33static k_handler_fn *k_handler[16] = { K_HANDLERS };
  34
  35/* maximum values each key_handler can handle */
  36static 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};
  40static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);
  41
  42static unsigned char ret_diacr[NR_DEAD] = {
  43        '`', '\'', '^', '~', '"', ','
  44};
  45
  46/*
  47 * Alloc/free of kbd_data structures.
  48 */
  49struct kbd_data *
  50kbd_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(ebc_key_maps), GFP_KERNEL);
  58        if (!kbd->key_maps)
  59                goto out_kbd;
  60        for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++) {
  61                if (ebc_key_maps[i]) {
  62                        kbd->key_maps[i] = kmemdup(ebc_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(ebc_func_table), GFP_KERNEL);
  70        if (!kbd->func_table)
  71                goto out_maps;
  72        for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++) {
  73                if (ebc_func_table[i]) {
  74                        kbd->func_table[i] = kstrdup(ebc_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(ebc_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 = ebc_accent_table_size;
  90        return kbd;
  91
  92out_fn_handler:
  93        kfree(kbd->fn_handler);
  94out_func:
  95        for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++)
  96                kfree(kbd->func_table[i]);
  97        kfree(kbd->func_table);
  98out_maps:
  99        for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++)
 100                kfree(kbd->key_maps[i]);
 101        kfree(kbd->key_maps);
 102out_kbd:
 103        kfree(kbd);
 104out:
 105        return NULL;
 106}
 107
 108void
 109kbd_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(ebc_func_table); i++)
 116                kfree(kbd->func_table[i]);
 117        kfree(kbd->func_table);
 118        for (i = 0; i < ARRAY_SIZE(ebc_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 */
 127void
 128kbd_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(ebc_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 */
 154void
 155kbd_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(ebc_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 */
 185static unsigned int
 186handle_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 */
 209static void
 210k_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 */
 219static void
 220k_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 */
 230static void
 231k_ignore(struct kbd_data *kbd, unsigned char value)
 232{
 233}
 234
 235/*
 236 * Function key handler.
 237 */
 238static void
 239k_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
 245static void
 246k_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 */
 259static void
 260to_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 */
 280void
 281kbd_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 */
 332static int
 333do_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
 404static int
 405do_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
 447int 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
 545EXPORT_SYMBOL(kbd_ioctl);
 546EXPORT_SYMBOL(kbd_ascebc);
 547EXPORT_SYMBOL(kbd_free);
 548EXPORT_SYMBOL(kbd_alloc);
 549EXPORT_SYMBOL(kbd_keycode);
 550