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/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
 32typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
 33static k_handler_fn K_HANDLERS;
 34static k_handler_fn *k_handler[16] = { K_HANDLERS };
 35
 36/* maximum values each key_handler can handle */
 37static 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};
 41static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);
 42
 43static 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 */
 76struct kbd_data *
 77kbd_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
119out_fn_handler:
120	kfree(kbd->fn_handler);
121out_func:
122	for (i = 0; i < ARRAY_SIZE(ebc_func_table); i++)
123		kfree(kbd->func_table[i]);
124	kfree(kbd->func_table);
125out_maps:
126	for (i = 0; i < ARRAY_SIZE(ebc_key_maps); i++)
127		kfree(kbd->key_maps[i]);
128	kfree(kbd->key_maps);
129out_kbd:
130	kfree(kbd);
131out:
132	return NULL;
133}
134
135void
136kbd_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 */
154void
155kbd_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 */
181void
182kbd_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 */
212static unsigned int
213handle_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 */
236static void
237k_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 */
246static void
247k_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 */
257static void
258k_ignore(struct kbd_data *kbd, unsigned char value)
259{
260}
261
262/*
263 * Function key handler.
264 */
265static void
266k_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
272static void
273k_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 */
286static void
287to_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 */
307void
308kbd_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 */
359static int
360do_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
435static int
436do_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
478int 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
576EXPORT_SYMBOL(kbd_ioctl);
577EXPORT_SYMBOL(kbd_ascebc);
578EXPORT_SYMBOL(kbd_free);
579EXPORT_SYMBOL(kbd_alloc);
580EXPORT_SYMBOL(kbd_keycode);