xref: /openbmc/linux/drivers/s390/char/keyboard.c (revision be709d48)
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 const unsigned char ret_diacr[NR_DEAD] = {
43 	'`',	/* dead_grave */
44 	'\'',	/* dead_acute */
45 	'^',	/* dead_circumflex */
46 	'~',	/* dead_tilda */
47 	'"',	/* dead_diaeresis */
48 	',',	/* dead_cedilla */
49 	'_',	/* dead_macron */
50 	'U',	/* dead_breve */
51 	'.',	/* dead_abovedot */
52 	'*',	/* dead_abovering */
53 	'=',	/* dead_doubleacute */
54 	'c',	/* dead_caron */
55 	'k',	/* dead_ogonek */
56 	'i',	/* dead_iota */
57 	'#',	/* dead_voiced_sound */
58 	'o',	/* dead_semivoiced_sound */
59 	'!',	/* dead_belowdot */
60 	'?',	/* dead_hook */
61 	'+',	/* dead_horn */
62 	'-',	/* dead_stroke */
63 	')',	/* dead_abovecomma */
64 	'(',	/* dead_abovereversedcomma */
65 	':',	/* dead_doublegrave */
66 	'n',	/* dead_invertedbreve */
67 	';',	/* dead_belowcomma */
68 	'$',	/* dead_currency */
69 	'@',	/* dead_greek */
70 };
71 
72 /*
73  * Alloc/free of kbd_data structures.
74  */
75 struct kbd_data *
76 kbd_alloc(void) {
77 	struct kbd_data *kbd;
78 	int i;
79 
80 	kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
81 	if (!kbd)
82 		goto out;
83 	kbd->key_maps = kzalloc(sizeof(ebc_key_maps), GFP_KERNEL);
84 	if (!kbd->key_maps)
85 		goto out_kbd;
86 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++) {
87 		if (ebc_key_maps[i]) {
88 			kbd->key_maps[i] = kmemdup(ebc_key_maps[i],
89 						   sizeof(u_short) * NR_KEYS,
90 						   GFP_KERNEL);
91 			if (!kbd->key_maps[i])
92 				goto out_maps;
93 		}
94 	}
95 	kbd->func_table = kzalloc(sizeof(ebc_func_table), GFP_KERNEL);
96 	if (!kbd->func_table)
97 		goto out_maps;
98 	for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++) {
99 		if (ebc_func_table[i]) {
100 			kbd->func_table[i] = kstrdup(ebc_func_table[i],
101 						     GFP_KERNEL);
102 			if (!kbd->func_table[i])
103 				goto out_func;
104 		}
105 	}
106 	kbd->fn_handler =
107 		kcalloc(NR_FN_HANDLER, sizeof(fn_handler_fn *), GFP_KERNEL);
108 	if (!kbd->fn_handler)
109 		goto out_func;
110 	kbd->accent_table = kmemdup(ebc_accent_table,
111 				    sizeof(struct kbdiacruc) * MAX_DIACR,
112 				    GFP_KERNEL);
113 	if (!kbd->accent_table)
114 		goto out_fn_handler;
115 	kbd->accent_table_size = ebc_accent_table_size;
116 	return kbd;
117 
118 out_fn_handler:
119 	kfree(kbd->fn_handler);
120 out_func:
121 	for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++)
122 		kfree(kbd->func_table[i]);
123 	kfree(kbd->func_table);
124 out_maps:
125 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++)
126 		kfree(kbd->key_maps[i]);
127 	kfree(kbd->key_maps);
128 out_kbd:
129 	kfree(kbd);
130 out:
131 	return NULL;
132 }
133 
134 void
135 kbd_free(struct kbd_data *kbd)
136 {
137 	int i;
138 
139 	kfree(kbd->accent_table);
140 	kfree(kbd->fn_handler);
141 	for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++)
142 		kfree(kbd->func_table[i]);
143 	kfree(kbd->func_table);
144 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++)
145 		kfree(kbd->key_maps[i]);
146 	kfree(kbd->key_maps);
147 	kfree(kbd);
148 }
149 
150 /*
151  * Generate ascii -> ebcdic translation table from kbd_data.
152  */
153 void
154 kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
155 {
156 	unsigned short *keymap, keysym;
157 	int i, j, k;
158 
159 	memset(ascebc, 0x40, 256);
160 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++) {
161 		keymap = kbd->key_maps[i];
162 		if (!keymap)
163 			continue;
164 		for (j = 0; j < NR_KEYS; j++) {
165 			k = ((i & 1) << 7) + j;
166 			keysym = keymap[j];
167 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
168 			    KTYP(keysym) == (KT_LETTER | 0xf0))
169 				ascebc[KVAL(keysym)] = k;
170 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
171 				ascebc[ret_diacr[KVAL(keysym)]] = k;
172 		}
173 	}
174 }
175 
176 #if 0
177 /*
178  * Generate ebcdic -> ascii translation table from kbd_data.
179  */
180 void
181 kbd_ebcasc(struct kbd_data *kbd, unsigned char *ebcasc)
182 {
183 	unsigned short *keymap, keysym;
184 	int i, j, k;
185 
186 	memset(ebcasc, ' ', 256);
187 	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++) {
188 		keymap = kbd->key_maps[i];
189 		if (!keymap)
190 			continue;
191 		for (j = 0; j < NR_KEYS; j++) {
192 			keysym = keymap[j];
193 			k = ((i & 1) << 7) + j;
194 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
195 			    KTYP(keysym) == (KT_LETTER | 0xf0))
196 				ebcasc[k] = KVAL(keysym);
197 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
198 				ebcasc[k] = ret_diacr[KVAL(keysym)];
199 		}
200 	}
201 }
202 #endif
203 
204 /*
205  * We have a combining character DIACR here, followed by the character CH.
206  * If the combination occurs in the table, return the corresponding value.
207  * Otherwise, if CH is a space or equals DIACR, return DIACR.
208  * Otherwise, conclude that DIACR was not combining after all,
209  * queue it and return CH.
210  */
211 static unsigned int
212 handle_diacr(struct kbd_data *kbd, unsigned int ch)
213 {
214 	int i, d;
215 
216 	d = kbd->diacr;
217 	kbd->diacr = 0;
218 
219 	for (i = 0; i < kbd->accent_table_size; i++) {
220 		if (kbd->accent_table[i].diacr == d &&
221 		    kbd->accent_table[i].base == ch)
222 			return kbd->accent_table[i].result;
223 	}
224 
225 	if (ch == ' ' || ch == d)
226 		return d;
227 
228 	kbd_put_queue(kbd->port, d);
229 	return ch;
230 }
231 
232 /*
233  * Handle dead key.
234  */
235 static void
236 k_dead(struct kbd_data *kbd, unsigned char value)
237 {
238 	value = ret_diacr[value];
239 	kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
240 }
241 
242 /*
243  * Normal character handler.
244  */
245 static void
246 k_self(struct kbd_data *kbd, unsigned char value)
247 {
248 	if (kbd->diacr)
249 		value = handle_diacr(kbd, value);
250 	kbd_put_queue(kbd->port, value);
251 }
252 
253 /*
254  * Special key handlers
255  */
256 static void
257 k_ignore(struct kbd_data *kbd, unsigned char value)
258 {
259 }
260 
261 /*
262  * Function key handler.
263  */
264 static void
265 k_fn(struct kbd_data *kbd, unsigned char value)
266 {
267 	if (kbd->func_table[value])
268 		kbd_puts_queue(kbd->port, kbd->func_table[value]);
269 }
270 
271 static void
272 k_spec(struct kbd_data *kbd, unsigned char value)
273 {
274 	if (value >= NR_FN_HANDLER)
275 		return;
276 	if (kbd->fn_handler[value])
277 		kbd->fn_handler[value](kbd);
278 }
279 
280 /*
281  * Put utf8 character to tty flip buffer.
282  * UTF-8 is defined for words of up to 31 bits,
283  * but we need only 16 bits here
284  */
285 static void
286 to_utf8(struct tty_port *port, ushort c)
287 {
288 	if (c < 0x80)
289 		/*  0******* */
290 		kbd_put_queue(port, c);
291 	else if (c < 0x800) {
292 		/* 110***** 10****** */
293 		kbd_put_queue(port, 0xc0 | (c >> 6));
294 		kbd_put_queue(port, 0x80 | (c & 0x3f));
295 	} else {
296 		/* 1110**** 10****** 10****** */
297 		kbd_put_queue(port, 0xe0 | (c >> 12));
298 		kbd_put_queue(port, 0x80 | ((c >> 6) & 0x3f));
299 		kbd_put_queue(port, 0x80 | (c & 0x3f));
300 	}
301 }
302 
303 /*
304  * Process keycode.
305  */
306 void
307 kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
308 {
309 	unsigned short keysym;
310 	unsigned char type, value;
311 
312 	if (!kbd)
313 		return;
314 
315 	if (keycode >= 384)
316 		keysym = kbd->key_maps[5][keycode - 384];
317 	else if (keycode >= 256)
318 		keysym = kbd->key_maps[4][keycode - 256];
319 	else if (keycode >= 128)
320 		keysym = kbd->key_maps[1][keycode - 128];
321 	else
322 		keysym = kbd->key_maps[0][keycode];
323 
324 	type = KTYP(keysym);
325 	if (type >= 0xf0) {
326 		type -= 0xf0;
327 		if (type == KT_LETTER)
328 			type = KT_LATIN;
329 		value = KVAL(keysym);
330 #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
331 		if (kbd->sysrq) {
332 			if (kbd->sysrq == K(KT_LATIN, '-')) {
333 				kbd->sysrq = 0;
334 				handle_sysrq(value);
335 				return;
336 			}
337 			if (value == '-') {
338 				kbd->sysrq = K(KT_LATIN, '-');
339 				return;
340 			}
341 			/* Incomplete sysrq sequence. */
342 			(*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
343 			kbd->sysrq = 0;
344 		} else if ((type == KT_LATIN && value == '^') ||
345 			   (type == KT_DEAD && ret_diacr[value] == '^')) {
346 			kbd->sysrq = K(type, value);
347 			return;
348 		}
349 #endif
350 		(*k_handler[type])(kbd, value);
351 	} else
352 		to_utf8(kbd->port, keysym);
353 }
354 
355 /*
356  * Ioctl stuff.
357  */
358 static int
359 do_kdsk_ioctl(struct kbd_data *kbd, struct kbentry __user *user_kbe,
360 	      int cmd, int perm)
361 {
362 	struct kbentry tmp;
363 	unsigned long kb_index, kb_table;
364 	ushort *key_map, val, ov;
365 
366 	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
367 		return -EFAULT;
368 	kb_index = (unsigned long) tmp.kb_index;
369 #if NR_KEYS < 256
370 	if (kb_index >= NR_KEYS)
371 		return -EINVAL;
372 #endif
373 	kb_table = (unsigned long) tmp.kb_table;
374 #if MAX_NR_KEYMAPS < 256
375 	if (kb_table >= MAX_NR_KEYMAPS)
376 		return -EINVAL;
377 	kb_table = array_index_nospec(kb_table , MAX_NR_KEYMAPS);
378 #endif
379 
380 	switch (cmd) {
381 	case KDGKBENT:
382 		key_map = kbd->key_maps[kb_table];
383 		if (key_map) {
384 		    val = U(key_map[kb_index]);
385 		    if (KTYP(val) >= KBD_NR_TYPES)
386 			val = K_HOLE;
387 		} else
388 		    val = (kb_index ? K_HOLE : K_NOSUCHMAP);
389 		return put_user(val, &user_kbe->kb_value);
390 	case KDSKBENT:
391 		if (!perm)
392 			return -EPERM;
393 		if (!kb_index && tmp.kb_value == K_NOSUCHMAP) {
394 			/* disallocate map */
395 			key_map = kbd->key_maps[kb_table];
396 			if (key_map) {
397 			    kbd->key_maps[kb_table] = NULL;
398 			    kfree(key_map);
399 			}
400 			break;
401 		}
402 
403 		if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
404 			return -EINVAL;
405 		if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
406 			return -EINVAL;
407 
408 		if (!(key_map = kbd->key_maps[kb_table])) {
409 			int j;
410 
411 			key_map = kmalloc(sizeof(plain_map),
412 						     GFP_KERNEL);
413 			if (!key_map)
414 				return -ENOMEM;
415 			kbd->key_maps[kb_table] = key_map;
416 			for (j = 0; j < NR_KEYS; j++)
417 				key_map[j] = U(K_HOLE);
418 		}
419 		ov = U(key_map[kb_index]);
420 		if (tmp.kb_value == ov)
421 			break;	/* nothing to do */
422 		/*
423 		 * Attention Key.
424 		 */
425 		if (((ov == K_SAK) || (tmp.kb_value == K_SAK)) &&
426 		    !capable(CAP_SYS_ADMIN))
427 			return -EPERM;
428 		key_map[kb_index] = U(tmp.kb_value);
429 		break;
430 	}
431 	return 0;
432 }
433 
434 static int
435 do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
436 	       int cmd, int perm)
437 {
438 	unsigned char kb_func;
439 	char *p;
440 	int len;
441 
442 	/* Get u_kbs->kb_func. */
443 	if (get_user(kb_func, &u_kbs->kb_func))
444 		return -EFAULT;
445 #if MAX_NR_FUNC < 256
446 	if (kb_func >= MAX_NR_FUNC)
447 		return -EINVAL;
448 #endif
449 
450 	switch (cmd) {
451 	case KDGKBSENT:
452 		p = kbd->func_table[kb_func];
453 		if (p) {
454 			len = strlen(p);
455 			if (len >= sizeof(u_kbs->kb_string))
456 				len = sizeof(u_kbs->kb_string) - 1;
457 			if (copy_to_user(u_kbs->kb_string, p, len))
458 				return -EFAULT;
459 		} else
460 			len = 0;
461 		if (put_user('\0', u_kbs->kb_string + len))
462 			return -EFAULT;
463 		break;
464 	case KDSKBSENT:
465 		if (!perm)
466 			return -EPERM;
467 		p = strndup_user(u_kbs->kb_string, sizeof(u_kbs->kb_string));
468 		if (IS_ERR(p))
469 			return PTR_ERR(p);
470 		kfree(kbd->func_table[kb_func]);
471 		kbd->func_table[kb_func] = p;
472 		break;
473 	}
474 	return 0;
475 }
476 
477 int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
478 {
479 	struct tty_struct *tty;
480 	void __user *argp;
481 	unsigned int ct;
482 	int perm;
483 
484 	argp = (void __user *)arg;
485 
486 	/*
487 	 * To have permissions to do most of the vt ioctls, we either have
488 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
489 	 */
490 	tty = tty_port_tty_get(kbd->port);
491 	/* FIXME this test is pretty racy */
492 	perm = current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG);
493 	tty_kref_put(tty);
494 	switch (cmd) {
495 	case KDGKBTYPE:
496 		return put_user(KB_101, (char __user *)argp);
497 	case KDGKBENT:
498 	case KDSKBENT:
499 		return do_kdsk_ioctl(kbd, argp, cmd, perm);
500 	case KDGKBSENT:
501 	case KDSKBSENT:
502 		return do_kdgkb_ioctl(kbd, argp, cmd, perm);
503 	case KDGKBDIACR:
504 	{
505 		struct kbdiacrs __user *a = argp;
506 		struct kbdiacr diacr;
507 		int i;
508 
509 		if (put_user(kbd->accent_table_size, &a->kb_cnt))
510 			return -EFAULT;
511 		for (i = 0; i < kbd->accent_table_size; i++) {
512 			diacr.diacr = kbd->accent_table[i].diacr;
513 			diacr.base = kbd->accent_table[i].base;
514 			diacr.result = kbd->accent_table[i].result;
515 			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
516 			return -EFAULT;
517 		}
518 		return 0;
519 	}
520 	case KDGKBDIACRUC:
521 	{
522 		struct kbdiacrsuc __user *a = argp;
523 
524 		ct = kbd->accent_table_size;
525 		if (put_user(ct, &a->kb_cnt))
526 			return -EFAULT;
527 		if (copy_to_user(a->kbdiacruc, kbd->accent_table,
528 				 ct * sizeof(struct kbdiacruc)))
529 			return -EFAULT;
530 		return 0;
531 	}
532 	case KDSKBDIACR:
533 	{
534 		struct kbdiacrs __user *a = argp;
535 		struct kbdiacr diacr;
536 		int i;
537 
538 		if (!perm)
539 			return -EPERM;
540 		if (get_user(ct, &a->kb_cnt))
541 			return -EFAULT;
542 		if (ct >= MAX_DIACR)
543 			return -EINVAL;
544 		kbd->accent_table_size = ct;
545 		for (i = 0; i < ct; i++) {
546 			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
547 				return -EFAULT;
548 			kbd->accent_table[i].diacr = diacr.diacr;
549 			kbd->accent_table[i].base = diacr.base;
550 			kbd->accent_table[i].result = diacr.result;
551 		}
552 		return 0;
553 	}
554 	case KDSKBDIACRUC:
555 	{
556 		struct kbdiacrsuc __user *a = argp;
557 
558 		if (!perm)
559 			return -EPERM;
560 		if (get_user(ct, &a->kb_cnt))
561 			return -EFAULT;
562 		if (ct >= MAX_DIACR)
563 			return -EINVAL;
564 		kbd->accent_table_size = ct;
565 		if (copy_from_user(kbd->accent_table, a->kbdiacruc,
566 				   ct * sizeof(struct kbdiacruc)))
567 			return -EFAULT;
568 		return 0;
569 	}
570 	default:
571 		return -ENOIOCTLCMD;
572 	}
573 }
574 
575 EXPORT_SYMBOL(kbd_ioctl);
576 EXPORT_SYMBOL(kbd_ascebc);
577 EXPORT_SYMBOL(kbd_free);
578 EXPORT_SYMBOL(kbd_alloc);
579 EXPORT_SYMBOL(kbd_keycode);
580