xref: /linux/drivers/s390/char/keyboard.c (revision bc46b7cbc58c4cb562b6a45a1fbc7b8e7b23df58)
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/export.h>
11 #include <linux/module.h>
12 #include <linux/sched/signal.h>
13 #include <linux/slab.h>
14 #include <linux/sysrq.h>
15 
16 #include <linux/consolemap.h>
17 #include <linux/kbd_kern.h>
18 #include <linux/kbd_diacr.h>
19 #include <linux/uaccess.h>
20 
21 #include "keyboard.h"
22 
23 /*
24  * Handler Tables.
25  */
26 #define K_HANDLERS\
27 	k_self,		k_fn,		k_spec,		k_ignore,\
28 	k_dead,		k_ignore,	k_ignore,	k_ignore,\
29 	k_ignore,	k_ignore,	k_ignore,	k_ignore,\
30 	k_ignore,	k_ignore,	k_ignore,	k_ignore
31 
32 typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
33 static k_handler_fn K_HANDLERS;
34 static k_handler_fn *k_handler[16] = { K_HANDLERS };
35 
36 /* maximum values each key_handler can handle */
37 static const int kbd_max_vals[] = {
38 	255, ARRAY_SIZE(func_table) - 1, NR_FN_HANDLER - 1, 0,
39 	NR_DEAD - 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
40 };
41 static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);
42 
43 static const unsigned char ret_diacr[NR_DEAD] = {
44 	'`',	/* dead_grave */
45 	'\'',	/* dead_acute */
46 	'^',	/* dead_circumflex */
47 	'~',	/* dead_tilda */
48 	'"',	/* dead_diaeresis */
49 	',',	/* dead_cedilla */
50 	'_',	/* dead_macron */
51 	'U',	/* dead_breve */
52 	'.',	/* dead_abovedot */
53 	'*',	/* dead_abovering */
54 	'=',	/* dead_doubleacute */
55 	'c',	/* dead_caron */
56 	'k',	/* dead_ogonek */
57 	'i',	/* dead_iota */
58 	'#',	/* dead_voiced_sound */
59 	'o',	/* dead_semivoiced_sound */
60 	'!',	/* dead_belowdot */
61 	'?',	/* dead_hook */
62 	'+',	/* dead_horn */
63 	'-',	/* dead_stroke */
64 	')',	/* dead_abovecomma */
65 	'(',	/* dead_abovereversedcomma */
66 	':',	/* dead_doublegrave */
67 	'n',	/* dead_invertedbreve */
68 	';',	/* dead_belowcomma */
69 	'$',	/* dead_currency */
70 	'@',	/* dead_greek */
71 };
72 
73 /*
74  * Alloc/free of kbd_data structures.
75  */
76 struct kbd_data *
kbd_alloc(void)77 kbd_alloc(void) {
78 	struct kbd_data *kbd;
79 	int i;
80 
81 	kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
82 	if (!kbd)
83 		goto out;
84 	kbd->key_maps = kzalloc(sizeof(ebc_key_maps), GFP_KERNEL);
85 	if (!kbd->key_maps)
86 		goto out_kbd;
87 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++) {
88 		if (ebc_key_maps[i]) {
89 			kbd->key_maps[i] = kmemdup(ebc_key_maps[i],
90 						   sizeof(u_short) * NR_KEYS,
91 						   GFP_KERNEL);
92 			if (!kbd->key_maps[i])
93 				goto out_maps;
94 		}
95 	}
96 	kbd->func_table = kzalloc(sizeof(ebc_func_table), GFP_KERNEL);
97 	if (!kbd->func_table)
98 		goto out_maps;
99 	for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++) {
100 		if (ebc_func_table[i]) {
101 			kbd->func_table[i] = kstrdup(ebc_func_table[i],
102 						     GFP_KERNEL);
103 			if (!kbd->func_table[i])
104 				goto out_func;
105 		}
106 	}
107 	kbd->fn_handler =
108 		kcalloc(NR_FN_HANDLER, sizeof(fn_handler_fn *), GFP_KERNEL);
109 	if (!kbd->fn_handler)
110 		goto out_func;
111 	kbd->accent_table = kmemdup(ebc_accent_table,
112 				    sizeof(struct kbdiacruc) * MAX_DIACR,
113 				    GFP_KERNEL);
114 	if (!kbd->accent_table)
115 		goto out_fn_handler;
116 	kbd->accent_table_size = ebc_accent_table_size;
117 	return kbd;
118 
119 out_fn_handler:
120 	kfree(kbd->fn_handler);
121 out_func:
122 	for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++)
123 		kfree(kbd->func_table[i]);
124 	kfree(kbd->func_table);
125 out_maps:
126 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++)
127 		kfree(kbd->key_maps[i]);
128 	kfree(kbd->key_maps);
129 out_kbd:
130 	kfree(kbd);
131 out:
132 	return NULL;
133 }
134 
135 void
kbd_free(struct kbd_data * kbd)136 kbd_free(struct kbd_data *kbd)
137 {
138 	int i;
139 
140 	kfree(kbd->accent_table);
141 	kfree(kbd->fn_handler);
142 	for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++)
143 		kfree(kbd->func_table[i]);
144 	kfree(kbd->func_table);
145 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++)
146 		kfree(kbd->key_maps[i]);
147 	kfree(kbd->key_maps);
148 	kfree(kbd);
149 }
150 
151 /*
152  * Generate ascii -> ebcdic translation table from kbd_data.
153  */
154 void
kbd_ascebc(struct kbd_data * kbd,unsigned char * ascebc)155 kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
156 {
157 	unsigned short *keymap, keysym;
158 	int i, j, k;
159 
160 	memset(ascebc, 0x40, 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 			k = ((i & 1) << 7) + j;
167 			keysym = keymap[j];
168 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
169 			    KTYP(keysym) == (KT_LETTER | 0xf0))
170 				ascebc[KVAL(keysym)] = k;
171 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
172 				ascebc[ret_diacr[KVAL(keysym)]] = k;
173 		}
174 	}
175 }
176 
177 #if 0
178 /*
179  * Generate ebcdic -> ascii translation table from kbd_data.
180  */
181 void
182 kbd_ebcasc(struct kbd_data *kbd, unsigned char *ebcasc)
183 {
184 	unsigned short *keymap, keysym;
185 	int i, j, k;
186 
187 	memset(ebcasc, ' ', 256);
188 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++) {
189 		keymap = kbd->key_maps[i];
190 		if (!keymap)
191 			continue;
192 		for (j = 0; j < NR_KEYS; j++) {
193 			keysym = keymap[j];
194 			k = ((i & 1) << 7) + j;
195 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
196 			    KTYP(keysym) == (KT_LETTER | 0xf0))
197 				ebcasc[k] = KVAL(keysym);
198 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
199 				ebcasc[k] = ret_diacr[KVAL(keysym)];
200 		}
201 	}
202 }
203 #endif
204 
205 /*
206  * We have a combining character DIACR here, followed by the character CH.
207  * If the combination occurs in the table, return the corresponding value.
208  * Otherwise, if CH is a space or equals DIACR, return DIACR.
209  * Otherwise, conclude that DIACR was not combining after all,
210  * queue it and return CH.
211  */
212 static unsigned int
handle_diacr(struct kbd_data * kbd,unsigned int ch)213 handle_diacr(struct kbd_data *kbd, unsigned int ch)
214 {
215 	int i, d;
216 
217 	d = kbd->diacr;
218 	kbd->diacr = 0;
219 
220 	for (i = 0; i < kbd->accent_table_size; i++) {
221 		if (kbd->accent_table[i].diacr == d &&
222 		    kbd->accent_table[i].base == ch)
223 			return kbd->accent_table[i].result;
224 	}
225 
226 	if (ch == ' ' || ch == d)
227 		return d;
228 
229 	kbd_put_queue(kbd->port, d);
230 	return ch;
231 }
232 
233 /*
234  * Handle dead key.
235  */
236 static void
k_dead(struct kbd_data * kbd,unsigned char value)237 k_dead(struct kbd_data *kbd, unsigned char value)
238 {
239 	value = ret_diacr[value];
240 	kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
241 }
242 
243 /*
244  * Normal character handler.
245  */
246 static void
k_self(struct kbd_data * kbd,unsigned char value)247 k_self(struct kbd_data *kbd, unsigned char value)
248 {
249 	if (kbd->diacr)
250 		value = handle_diacr(kbd, value);
251 	kbd_put_queue(kbd->port, value);
252 }
253 
254 /*
255  * Special key handlers
256  */
257 static void
k_ignore(struct kbd_data * kbd,unsigned char value)258 k_ignore(struct kbd_data *kbd, unsigned char value)
259 {
260 }
261 
262 /*
263  * Function key handler.
264  */
265 static void
k_fn(struct kbd_data * kbd,unsigned char value)266 k_fn(struct kbd_data *kbd, unsigned char value)
267 {
268 	if (kbd->func_table[value])
269 		kbd_puts_queue(kbd->port, kbd->func_table[value]);
270 }
271 
272 static void
k_spec(struct kbd_data * kbd,unsigned char value)273 k_spec(struct kbd_data *kbd, unsigned char value)
274 {
275 	if (value >= NR_FN_HANDLER)
276 		return;
277 	if (kbd->fn_handler[value])
278 		kbd->fn_handler[value](kbd);
279 }
280 
281 /*
282  * Put utf8 character to tty flip buffer.
283  * UTF-8 is defined for words of up to 31 bits,
284  * but we need only 16 bits here
285  */
286 static void
to_utf8(struct tty_port * port,ushort c)287 to_utf8(struct tty_port *port, ushort c)
288 {
289 	if (c < 0x80)
290 		/*  0******* */
291 		kbd_put_queue(port, c);
292 	else if (c < 0x800) {
293 		/* 110***** 10****** */
294 		kbd_put_queue(port, 0xc0 | (c >> 6));
295 		kbd_put_queue(port, 0x80 | (c & 0x3f));
296 	} else {
297 		/* 1110**** 10****** 10****** */
298 		kbd_put_queue(port, 0xe0 | (c >> 12));
299 		kbd_put_queue(port, 0x80 | ((c >> 6) & 0x3f));
300 		kbd_put_queue(port, 0x80 | (c & 0x3f));
301 	}
302 }
303 
304 /*
305  * Process keycode.
306  */
307 void
kbd_keycode(struct kbd_data * kbd,unsigned int keycode)308 kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
309 {
310 	unsigned short keysym;
311 	unsigned char type, value;
312 
313 	if (!kbd)
314 		return;
315 
316 	if (keycode >= 384)
317 		keysym = kbd->key_maps[5][keycode - 384];
318 	else if (keycode >= 256)
319 		keysym = kbd->key_maps[4][keycode - 256];
320 	else if (keycode >= 128)
321 		keysym = kbd->key_maps[1][keycode - 128];
322 	else
323 		keysym = kbd->key_maps[0][keycode];
324 
325 	type = KTYP(keysym);
326 	if (type >= 0xf0) {
327 		type -= 0xf0;
328 		if (type == KT_LETTER)
329 			type = KT_LATIN;
330 		value = KVAL(keysym);
331 #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
332 		if (kbd->sysrq) {
333 			if (kbd->sysrq == K(KT_LATIN, '-')) {
334 				kbd->sysrq = 0;
335 				handle_sysrq(value);
336 				return;
337 			}
338 			if (value == '-') {
339 				kbd->sysrq = K(KT_LATIN, '-');
340 				return;
341 			}
342 			/* Incomplete sysrq sequence. */
343 			(*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
344 			kbd->sysrq = 0;
345 		} else if ((type == KT_LATIN && value == '^') ||
346 			   (type == KT_DEAD && ret_diacr[value] == '^')) {
347 			kbd->sysrq = K(type, value);
348 			return;
349 		}
350 #endif
351 		(*k_handler[type])(kbd, value);
352 	} else
353 		to_utf8(kbd->port, keysym);
354 }
355 
356 /*
357  * Ioctl stuff.
358  */
359 static int
do_kdsk_ioctl(struct kbd_data * kbd,struct kbentry __user * user_kbe,int cmd,int perm)360 do_kdsk_ioctl(struct kbd_data *kbd, struct kbentry __user *user_kbe,
361 	      int cmd, int perm)
362 {
363 	struct kbentry tmp;
364 	unsigned long kb_index, kb_table;
365 	ushort *key_map, val, ov;
366 
367 	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
368 		return -EFAULT;
369 	kb_index = (unsigned long) tmp.kb_index;
370 #if NR_KEYS < 256
371 	if (kb_index >= NR_KEYS)
372 		return -EINVAL;
373 #endif
374 	kb_table = (unsigned long) tmp.kb_table;
375 #if MAX_NR_KEYMAPS < 256
376 	if (kb_table >= MAX_NR_KEYMAPS)
377 		return -EINVAL;
378 	kb_table = array_index_nospec(kb_table , MAX_NR_KEYMAPS);
379 #endif
380 
381 	switch (cmd) {
382 	case KDGKBENT:
383 		key_map = kbd->key_maps[kb_table];
384 		if (key_map) {
385 		    val = U(key_map[kb_index]);
386 		    if (KTYP(val) >= KBD_NR_TYPES)
387 			val = K_HOLE;
388 		} else
389 		    val = (kb_index ? K_HOLE : K_NOSUCHMAP);
390 		return put_user(val, &user_kbe->kb_value);
391 	case KDSKBENT:
392 		if (!perm)
393 			return -EPERM;
394 		if (!kb_index && tmp.kb_value == K_NOSUCHMAP) {
395 			/* disallocate map */
396 			key_map = kbd->key_maps[kb_table];
397 			if (key_map) {
398 			    kbd->key_maps[kb_table] = NULL;
399 			    kfree(key_map);
400 			}
401 			break;
402 		}
403 
404 		if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
405 			return -EINVAL;
406 		if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
407 			return -EINVAL;
408 
409 		if (!(key_map = kbd->key_maps[kb_table])) {
410 			int j;
411 
412 			key_map = kmalloc(sizeof(plain_map),
413 						     GFP_KERNEL);
414 			if (!key_map)
415 				return -ENOMEM;
416 			kbd->key_maps[kb_table] = key_map;
417 			for (j = 0; j < NR_KEYS; j++)
418 				key_map[j] = U(K_HOLE);
419 		}
420 		ov = U(key_map[kb_index]);
421 		if (tmp.kb_value == ov)
422 			break;	/* nothing to do */
423 		/*
424 		 * Attention Key.
425 		 */
426 		if (((ov == K_SAK) || (tmp.kb_value == K_SAK)) &&
427 		    !capable(CAP_SYS_ADMIN))
428 			return -EPERM;
429 		key_map[kb_index] = U(tmp.kb_value);
430 		break;
431 	}
432 	return 0;
433 }
434 
435 static int
do_kdgkb_ioctl(struct kbd_data * kbd,struct kbsentry __user * u_kbs,int cmd,int perm)436 do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
437 	       int cmd, int perm)
438 {
439 	unsigned char kb_func;
440 	char *p;
441 	int len;
442 
443 	/* Get u_kbs->kb_func. */
444 	if (get_user(kb_func, &u_kbs->kb_func))
445 		return -EFAULT;
446 #if MAX_NR_FUNC < 256
447 	if (kb_func >= MAX_NR_FUNC)
448 		return -EINVAL;
449 #endif
450 
451 	switch (cmd) {
452 	case KDGKBSENT:
453 		p = kbd->func_table[kb_func];
454 		if (p) {
455 			len = strlen(p);
456 			if (len >= sizeof(u_kbs->kb_string))
457 				len = sizeof(u_kbs->kb_string) - 1;
458 			if (copy_to_user(u_kbs->kb_string, p, len))
459 				return -EFAULT;
460 		} else
461 			len = 0;
462 		if (put_user('\0', u_kbs->kb_string + len))
463 			return -EFAULT;
464 		break;
465 	case KDSKBSENT:
466 		if (!perm)
467 			return -EPERM;
468 		p = strndup_user(u_kbs->kb_string, sizeof(u_kbs->kb_string));
469 		if (IS_ERR(p))
470 			return PTR_ERR(p);
471 		kfree(kbd->func_table[kb_func]);
472 		kbd->func_table[kb_func] = p;
473 		break;
474 	}
475 	return 0;
476 }
477 
kbd_ioctl(struct kbd_data * kbd,unsigned int cmd,unsigned long arg)478 int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
479 {
480 	struct tty_struct *tty;
481 	void __user *argp;
482 	unsigned int ct;
483 	int perm;
484 
485 	argp = (void __user *)arg;
486 
487 	/*
488 	 * To have permissions to do most of the vt ioctls, we either have
489 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
490 	 */
491 	tty = tty_port_tty_get(kbd->port);
492 	/* FIXME this test is pretty racy */
493 	perm = current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG);
494 	tty_kref_put(tty);
495 	switch (cmd) {
496 	case KDGKBTYPE:
497 		return put_user(KB_101, (char __user *)argp);
498 	case KDGKBENT:
499 	case KDSKBENT:
500 		return do_kdsk_ioctl(kbd, argp, cmd, perm);
501 	case KDGKBSENT:
502 	case KDSKBSENT:
503 		return do_kdgkb_ioctl(kbd, argp, cmd, perm);
504 	case KDGKBDIACR:
505 	{
506 		struct kbdiacrs __user *a = argp;
507 		struct kbdiacr diacr;
508 		int i;
509 
510 		if (put_user(kbd->accent_table_size, &a->kb_cnt))
511 			return -EFAULT;
512 		for (i = 0; i < kbd->accent_table_size; i++) {
513 			diacr.diacr = kbd->accent_table[i].diacr;
514 			diacr.base = kbd->accent_table[i].base;
515 			diacr.result = kbd->accent_table[i].result;
516 			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
517 			return -EFAULT;
518 		}
519 		return 0;
520 	}
521 	case KDGKBDIACRUC:
522 	{
523 		struct kbdiacrsuc __user *a = argp;
524 
525 		ct = kbd->accent_table_size;
526 		if (put_user(ct, &a->kb_cnt))
527 			return -EFAULT;
528 		if (copy_to_user(a->kbdiacruc, kbd->accent_table,
529 				 ct * sizeof(struct kbdiacruc)))
530 			return -EFAULT;
531 		return 0;
532 	}
533 	case KDSKBDIACR:
534 	{
535 		struct kbdiacrs __user *a = argp;
536 		struct kbdiacr diacr;
537 		int i;
538 
539 		if (!perm)
540 			return -EPERM;
541 		if (get_user(ct, &a->kb_cnt))
542 			return -EFAULT;
543 		if (ct >= MAX_DIACR)
544 			return -EINVAL;
545 		kbd->accent_table_size = ct;
546 		for (i = 0; i < ct; i++) {
547 			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
548 				return -EFAULT;
549 			kbd->accent_table[i].diacr = diacr.diacr;
550 			kbd->accent_table[i].base = diacr.base;
551 			kbd->accent_table[i].result = diacr.result;
552 		}
553 		return 0;
554 	}
555 	case KDSKBDIACRUC:
556 	{
557 		struct kbdiacrsuc __user *a = argp;
558 
559 		if (!perm)
560 			return -EPERM;
561 		if (get_user(ct, &a->kb_cnt))
562 			return -EFAULT;
563 		if (ct >= MAX_DIACR)
564 			return -EINVAL;
565 		kbd->accent_table_size = ct;
566 		if (copy_from_user(kbd->accent_table, a->kbdiacruc,
567 				   ct * sizeof(struct kbdiacruc)))
568 			return -EFAULT;
569 		return 0;
570 	}
571 	default:
572 		return -ENOIOCTLCMD;
573 	}
574 }
575 
576 EXPORT_SYMBOL(kbd_ioctl);
577 EXPORT_SYMBOL(kbd_ascebc);
578 EXPORT_SYMBOL(kbd_free);
579 EXPORT_SYMBOL(kbd_alloc);
580 EXPORT_SYMBOL(kbd_keycode);
581