xref: /linux/drivers/s390/char/keyboard.c (revision 6e8331ac6973435b1e7604c30f2ad394035b46e1) 
1 /*
2  *  drivers/s390/char/keyboard.c
3  *    ebcdic keycode functions for s390 console drivers
4  *
5  *  S390 version
6  *    Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
7  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
8  */
9 
10 #include <linux/module.h>
11 #include <linux/sched.h>
12 #include <linux/sysrq.h>
13 
14 #include <linux/kbd_kern.h>
15 #include <linux/kbd_diacr.h>
16 #include <asm/uaccess.h>
17 
18 #include "keyboard.h"
19 
20 /*
21  * Handler Tables.
22  */
23 #define K_HANDLERS\
24 	k_self,		k_fn,		k_spec,		k_ignore,\
25 	k_dead,		k_ignore,	k_ignore,	k_ignore,\
26 	k_ignore,	k_ignore,	k_ignore,	k_ignore,\
27 	k_ignore,	k_ignore,	k_ignore,	k_ignore
28 
29 typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
30 static k_handler_fn K_HANDLERS;
31 static k_handler_fn *k_handler[16] = { K_HANDLERS };
32 
33 /* maximum values each key_handler can handle */
34 static const int kbd_max_vals[] = {
35 	255, ARRAY_SIZE(func_table) - 1, NR_FN_HANDLER - 1, 0,
36 	NR_DEAD - 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
37 };
38 static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);
39 
40 static unsigned char ret_diacr[NR_DEAD] = {
41 	'`', '\'', '^', '~', '"', ','
42 };
43 
44 /*
45  * Alloc/free of kbd_data structures.
46  */
47 struct kbd_data *
48 kbd_alloc(void) {
49 	struct kbd_data *kbd;
50 	int i, len;
51 
52 	kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
53 	if (!kbd)
54 		goto out;
55 	kbd->key_maps = kzalloc(sizeof(key_maps), GFP_KERNEL);
56 	if (!kbd->key_maps)
57 		goto out_kbd;
58 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
59 		if (key_maps[i]) {
60 			kbd->key_maps[i] =
61 				kmalloc(sizeof(u_short)*NR_KEYS, GFP_KERNEL);
62 			if (!kbd->key_maps[i])
63 				goto out_maps;
64 			memcpy(kbd->key_maps[i], key_maps[i],
65 			       sizeof(u_short)*NR_KEYS);
66 		}
67 	}
68 	kbd->func_table = kzalloc(sizeof(func_table), GFP_KERNEL);
69 	if (!kbd->func_table)
70 		goto out_maps;
71 	for (i = 0; i < ARRAY_SIZE(func_table); i++) {
72 		if (func_table[i]) {
73 			len = strlen(func_table[i]) + 1;
74 			kbd->func_table[i] = kmalloc(len, GFP_KERNEL);
75 			if (!kbd->func_table[i])
76 				goto out_func;
77 			memcpy(kbd->func_table[i], func_table[i], len);
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 =
85 		kmalloc(sizeof(struct kbdiacr)*MAX_DIACR, GFP_KERNEL);
86 	if (!kbd->accent_table)
87 		goto out_fn_handler;
88 	memcpy(kbd->accent_table, accent_table,
89 	       sizeof(struct kbdiacr)*MAX_DIACR);
90 	kbd->accent_table_size = accent_table_size;
91 	return kbd;
92 
93 out_fn_handler:
94 	kfree(kbd->fn_handler);
95 out_func:
96 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
97 		kfree(kbd->func_table[i]);
98 	kfree(kbd->func_table);
99 out_maps:
100 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
101 		kfree(kbd->key_maps[i]);
102 	kfree(kbd->key_maps);
103 out_kbd:
104 	kfree(kbd);
105 out:
106 	return NULL;
107 }
108 
109 void
110 kbd_free(struct kbd_data *kbd)
111 {
112 	int i;
113 
114 	kfree(kbd->accent_table);
115 	kfree(kbd->fn_handler);
116 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
117 		kfree(kbd->func_table[i]);
118 	kfree(kbd->func_table);
119 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
120 		kfree(kbd->key_maps[i]);
121 	kfree(kbd->key_maps);
122 	kfree(kbd);
123 }
124 
125 /*
126  * Generate ascii -> ebcdic translation table from kbd_data.
127  */
128 void
129 kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
130 {
131 	unsigned short *keymap, keysym;
132 	int i, j, k;
133 
134 	memset(ascebc, 0x40, 256);
135 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
136 		keymap = kbd->key_maps[i];
137 		if (!keymap)
138 			continue;
139 		for (j = 0; j < NR_KEYS; j++) {
140 			k = ((i & 1) << 7) + j;
141 			keysym = keymap[j];
142 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
143 			    KTYP(keysym) == (KT_LETTER | 0xf0))
144 				ascebc[KVAL(keysym)] = k;
145 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
146 				ascebc[ret_diacr[KVAL(keysym)]] = k;
147 		}
148 	}
149 }
150 
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 
177 /*
178  * We have a combining character DIACR here, followed by the character CH.
179  * If the combination occurs in the table, return the corresponding value.
180  * Otherwise, if CH is a space or equals DIACR, return DIACR.
181  * Otherwise, conclude that DIACR was not combining after all,
182  * queue it and return CH.
183  */
184 static unsigned char
185 handle_diacr(struct kbd_data *kbd, unsigned char ch)
186 {
187 	int i, d;
188 
189 	d = kbd->diacr;
190 	kbd->diacr = 0;
191 
192 	for (i = 0; i < kbd->accent_table_size; i++) {
193 		if (kbd->accent_table[i].diacr == d &&
194 		    kbd->accent_table[i].base == ch)
195 			return kbd->accent_table[i].result;
196 	}
197 
198 	if (ch == ' ' || ch == d)
199 		return d;
200 
201 	kbd_put_queue(kbd->tty, d);
202 	return ch;
203 }
204 
205 /*
206  * Handle dead key.
207  */
208 static void
209 k_dead(struct kbd_data *kbd, unsigned char value)
210 {
211 	value = ret_diacr[value];
212 	kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
213 }
214 
215 /*
216  * Normal character handler.
217  */
218 static void
219 k_self(struct kbd_data *kbd, unsigned char value)
220 {
221 	if (kbd->diacr)
222 		value = handle_diacr(kbd, value);
223 	kbd_put_queue(kbd->tty, value);
224 }
225 
226 /*
227  * Special key handlers
228  */
229 static void
230 k_ignore(struct kbd_data *kbd, unsigned char value)
231 {
232 }
233 
234 /*
235  * Function key handler.
236  */
237 static void
238 k_fn(struct kbd_data *kbd, unsigned char value)
239 {
240 	if (kbd->func_table[value])
241 		kbd_puts_queue(kbd->tty, kbd->func_table[value]);
242 }
243 
244 static void
245 k_spec(struct kbd_data *kbd, unsigned char value)
246 {
247 	if (value >= NR_FN_HANDLER)
248 		return;
249 	if (kbd->fn_handler[value])
250 		kbd->fn_handler[value](kbd);
251 }
252 
253 /*
254  * Put utf8 character to tty flip buffer.
255  * UTF-8 is defined for words of up to 31 bits,
256  * but we need only 16 bits here
257  */
258 static void
259 to_utf8(struct tty_struct *tty, ushort c)
260 {
261 	if (c < 0x80)
262 		/*  0******* */
263 		kbd_put_queue(tty, c);
264 	else if (c < 0x800) {
265 		/* 110***** 10****** */
266 		kbd_put_queue(tty, 0xc0 | (c >> 6));
267 		kbd_put_queue(tty, 0x80 | (c & 0x3f));
268 	} else {
269 		/* 1110**** 10****** 10****** */
270 		kbd_put_queue(tty, 0xe0 | (c >> 12));
271 		kbd_put_queue(tty, 0x80 | ((c >> 6) & 0x3f));
272 		kbd_put_queue(tty, 0x80 | (c & 0x3f));
273 	}
274 }
275 
276 /*
277  * Process keycode.
278  */
279 void
280 kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
281 {
282 	unsigned short keysym;
283 	unsigned char type, value;
284 
285 	if (!kbd || !kbd->tty)
286 		return;
287 
288 	if (keycode >= 384)
289 		keysym = kbd->key_maps[5][keycode - 384];
290 	else if (keycode >= 256)
291 		keysym = kbd->key_maps[4][keycode - 256];
292 	else if (keycode >= 128)
293 		keysym = kbd->key_maps[1][keycode - 128];
294 	else
295 		keysym = kbd->key_maps[0][keycode];
296 
297 	type = KTYP(keysym);
298 	if (type >= 0xf0) {
299 		type -= 0xf0;
300 		if (type == KT_LETTER)
301 			type = KT_LATIN;
302 		value = KVAL(keysym);
303 #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
304 		if (kbd->sysrq) {
305 			if (kbd->sysrq == K(KT_LATIN, '-')) {
306 				kbd->sysrq = 0;
307 				handle_sysrq(value, NULL, kbd->tty);
308 				return;
309 			}
310 			if (value == '-') {
311 				kbd->sysrq = K(KT_LATIN, '-');
312 				return;
313 			}
314 			/* Incomplete sysrq sequence. */
315 			(*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
316 			kbd->sysrq = 0;
317 		} else if ((type == KT_LATIN && value == '^') ||
318 			   (type == KT_DEAD && ret_diacr[value] == '^')) {
319 			kbd->sysrq = K(type, value);
320 			return;
321 		}
322 #endif
323 		(*k_handler[type])(kbd, value);
324 	} else
325 		to_utf8(kbd->tty, keysym);
326 }
327 
328 /*
329  * Ioctl stuff.
330  */
331 static int
332 do_kdsk_ioctl(struct kbd_data *kbd, struct kbentry __user *user_kbe,
333 	      int cmd, int perm)
334 {
335 	struct kbentry tmp;
336 	ushort *key_map, val, ov;
337 
338 	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
339 		return -EFAULT;
340 #if NR_KEYS < 256
341 	if (tmp.kb_index >= NR_KEYS)
342 		return -EINVAL;
343 #endif
344 #if MAX_NR_KEYMAPS < 256
345 	if (tmp.kb_table >= MAX_NR_KEYMAPS)
346 		return -EINVAL;
347 #endif
348 
349 	switch (cmd) {
350 	case KDGKBENT:
351 		key_map = kbd->key_maps[tmp.kb_table];
352 		if (key_map) {
353 		    val = U(key_map[tmp.kb_index]);
354 		    if (KTYP(val) >= KBD_NR_TYPES)
355 			val = K_HOLE;
356 		} else
357 		    val = (tmp.kb_index ? K_HOLE : K_NOSUCHMAP);
358 		return put_user(val, &user_kbe->kb_value);
359 	case KDSKBENT:
360 		if (!perm)
361 			return -EPERM;
362 		if (!tmp.kb_index && tmp.kb_value == K_NOSUCHMAP) {
363 			/* disallocate map */
364 			key_map = kbd->key_maps[tmp.kb_table];
365 			if (key_map) {
366 			    kbd->key_maps[tmp.kb_table] = NULL;
367 			    kfree(key_map);
368 			}
369 			break;
370 		}
371 
372 		if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
373 			return -EINVAL;
374 		if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
375 			return -EINVAL;
376 
377 		if (!(key_map = kbd->key_maps[tmp.kb_table])) {
378 			int j;
379 
380 			key_map = (ushort *) kmalloc(sizeof(plain_map),
381 						     GFP_KERNEL);
382 			if (!key_map)
383 				return -ENOMEM;
384 			kbd->key_maps[tmp.kb_table] = key_map;
385 			for (j = 0; j < NR_KEYS; j++)
386 				key_map[j] = U(K_HOLE);
387 		}
388 		ov = U(key_map[tmp.kb_index]);
389 		if (tmp.kb_value == ov)
390 			break;	/* nothing to do */
391 		/*
392 		 * Attention Key.
393 		 */
394 		if (((ov == K_SAK) || (tmp.kb_value == K_SAK)) &&
395 		    !capable(CAP_SYS_ADMIN))
396 			return -EPERM;
397 		key_map[tmp.kb_index] = U(tmp.kb_value);
398 		break;
399 	}
400 	return 0;
401 }
402 
403 static int
404 do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
405 	       int cmd, int perm)
406 {
407 	unsigned char kb_func;
408 	char *p;
409 	int len;
410 
411 	/* Get u_kbs->kb_func. */
412 	if (get_user(kb_func, &u_kbs->kb_func))
413 		return -EFAULT;
414 #if MAX_NR_FUNC < 256
415 	if (kb_func >= MAX_NR_FUNC)
416 		return -EINVAL;
417 #endif
418 
419 	switch (cmd) {
420 	case KDGKBSENT:
421 		p = kbd->func_table[kb_func];
422 		if (p) {
423 			len = strlen(p);
424 			if (len >= sizeof(u_kbs->kb_string))
425 				len = sizeof(u_kbs->kb_string) - 1;
426 			if (copy_to_user(u_kbs->kb_string, p, len))
427 				return -EFAULT;
428 		} else
429 			len = 0;
430 		if (put_user('\0', u_kbs->kb_string + len))
431 			return -EFAULT;
432 		break;
433 	case KDSKBSENT:
434 		if (!perm)
435 			return -EPERM;
436 		len = strnlen_user(u_kbs->kb_string,
437 				   sizeof(u_kbs->kb_string) - 1);
438 		if (!len)
439 			return -EFAULT;
440 		if (len > sizeof(u_kbs->kb_string) - 1)
441 			return -EINVAL;
442 		p = kmalloc(len + 1, GFP_KERNEL);
443 		if (!p)
444 			return -ENOMEM;
445 		if (copy_from_user(p, u_kbs->kb_string, len)) {
446 			kfree(p);
447 			return -EFAULT;
448 		}
449 		p[len] = 0;
450 		kfree(kbd->func_table[kb_func]);
451 		kbd->func_table[kb_func] = p;
452 		break;
453 	}
454 	return 0;
455 }
456 
457 int
458 kbd_ioctl(struct kbd_data *kbd, struct file *file,
459 	  unsigned int cmd, unsigned long arg)
460 {
461 	struct kbdiacrs __user *a;
462 	void __user *argp;
463 	int ct, perm;
464 
465 	argp = (void __user *)arg;
466 
467 	/*
468 	 * To have permissions to do most of the vt ioctls, we either have
469 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
470 	 */
471 	perm = current->signal->tty == kbd->tty || capable(CAP_SYS_TTY_CONFIG);
472 	switch (cmd) {
473 	case KDGKBTYPE:
474 		return put_user(KB_101, (char __user *)argp);
475 	case KDGKBENT:
476 	case KDSKBENT:
477 		return do_kdsk_ioctl(kbd, argp, cmd, perm);
478 	case KDGKBSENT:
479 	case KDSKBSENT:
480 		return do_kdgkb_ioctl(kbd, argp, cmd, perm);
481 	case KDGKBDIACR:
482 		a = argp;
483 
484 		if (put_user(kbd->accent_table_size, &a->kb_cnt))
485 			return -EFAULT;
486 		ct = kbd->accent_table_size;
487 		if (copy_to_user(a->kbdiacr, kbd->accent_table,
488 				 ct * sizeof(struct kbdiacr)))
489 			return -EFAULT;
490 		return 0;
491 	case KDSKBDIACR:
492 		a = argp;
493 		if (!perm)
494 			return -EPERM;
495 		if (get_user(ct, &a->kb_cnt))
496 			return -EFAULT;
497 		if (ct >= MAX_DIACR)
498 			return -EINVAL;
499 		kbd->accent_table_size = ct;
500 		if (copy_from_user(kbd->accent_table, a->kbdiacr,
501 				   ct * sizeof(struct kbdiacr)))
502 			return -EFAULT;
503 		return 0;
504 	default:
505 		return -ENOIOCTLCMD;
506 	}
507 }
508 
509 EXPORT_SYMBOL(kbd_ioctl);
510 EXPORT_SYMBOL(kbd_ascebc);
511 EXPORT_SYMBOL(kbd_free);
512 EXPORT_SYMBOL(kbd_alloc);
513 EXPORT_SYMBOL(kbd_keycode);
514