xref: /linux/drivers/s390/char/keyboard.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15) 
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/config.h>
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/sysrq.h>
14 
15 #include <linux/kbd_kern.h>
16 #include <linux/kbd_diacr.h>
17 #include <asm/uaccess.h>
18 
19 #include "keyboard.h"
20 
21 /*
22  * Handler Tables.
23  */
24 #define K_HANDLERS\
25 	k_self,		k_fn,		k_spec,		k_ignore,\
26 	k_dead,		k_ignore,	k_ignore,	k_ignore,\
27 	k_ignore,	k_ignore,	k_ignore,	k_ignore,\
28 	k_ignore,	k_ignore,	k_ignore,	k_ignore
29 
30 typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
31 static k_handler_fn K_HANDLERS;
32 static k_handler_fn *k_handler[16] = { K_HANDLERS };
33 
34 /* maximum values each key_handler can handle */
35 static const int kbd_max_vals[] = {
36 	255, ARRAY_SIZE(func_table) - 1, NR_FN_HANDLER - 1, 0,
37 	NR_DEAD - 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
38 };
39 static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);
40 
41 static unsigned char ret_diacr[NR_DEAD] = {
42 	'`', '\'', '^', '~', '"', ','
43 };
44 
45 /*
46  * Alloc/free of kbd_data structures.
47  */
48 struct kbd_data *
49 kbd_alloc(void) {
50 	struct kbd_data *kbd;
51 	int i, len;
52 
53 	kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
54 	if (!kbd)
55 		goto out;
56 	kbd->key_maps = kzalloc(sizeof(key_maps), GFP_KERNEL);
57 	if (!kbd->key_maps)
58 		goto out_kbd;
59 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
60 		if (key_maps[i]) {
61 			kbd->key_maps[i] =
62 				kmalloc(sizeof(u_short)*NR_KEYS, GFP_KERNEL);
63 			if (!kbd->key_maps[i])
64 				goto out_maps;
65 			memcpy(kbd->key_maps[i], key_maps[i],
66 			       sizeof(u_short)*NR_KEYS);
67 		}
68 	}
69 	kbd->func_table = kzalloc(sizeof(func_table), GFP_KERNEL);
70 	if (!kbd->func_table)
71 		goto out_maps;
72 	for (i = 0; i < ARRAY_SIZE(func_table); i++) {
73 		if (func_table[i]) {
74 			len = strlen(func_table[i]) + 1;
75 			kbd->func_table[i] = kmalloc(len, GFP_KERNEL);
76 			if (!kbd->func_table[i])
77 				goto out_func;
78 			memcpy(kbd->func_table[i], func_table[i], len);
79 		}
80 	}
81 	kbd->fn_handler =
82 		kzalloc(sizeof(fn_handler_fn *) * NR_FN_HANDLER, GFP_KERNEL);
83 	if (!kbd->fn_handler)
84 		goto out_func;
85 	kbd->accent_table =
86 		kmalloc(sizeof(struct kbdiacr)*MAX_DIACR, GFP_KERNEL);
87 	if (!kbd->accent_table)
88 		goto out_fn_handler;
89 	memcpy(kbd->accent_table, accent_table,
90 	       sizeof(struct kbdiacr)*MAX_DIACR);
91 	kbd->accent_table_size = accent_table_size;
92 	return kbd;
93 
94 out_fn_handler:
95 	kfree(kbd->fn_handler);
96 out_func:
97 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
98 		kfree(kbd->func_table[i]);
99 	kfree(kbd->func_table);
100 out_maps:
101 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
102 		kfree(kbd->key_maps[i]);
103 	kfree(kbd->key_maps);
104 out_kbd:
105 	kfree(kbd);
106 out:
107 	return 0;
108 }
109 
110 void
111 kbd_free(struct kbd_data *kbd)
112 {
113 	int i;
114 
115 	kfree(kbd->accent_table);
116 	kfree(kbd->fn_handler);
117 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
118 		kfree(kbd->func_table[i]);
119 	kfree(kbd->func_table);
120 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
121 		kfree(kbd->key_maps[i]);
122 	kfree(kbd->key_maps);
123 	kfree(kbd);
124 }
125 
126 /*
127  * Generate ascii -> ebcdic translation table from kbd_data.
128  */
129 void
130 kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
131 {
132 	unsigned short *keymap, keysym;
133 	int i, j, k;
134 
135 	memset(ascebc, 0x40, 256);
136 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
137 		keymap = kbd->key_maps[i];
138 		if (!keymap)
139 			continue;
140 		for (j = 0; j < NR_KEYS; j++) {
141 			k = ((i & 1) << 7) + j;
142 			keysym = keymap[j];
143 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
144 			    KTYP(keysym) == (KT_LETTER | 0xf0))
145 				ascebc[KVAL(keysym)] = k;
146 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
147 				ascebc[ret_diacr[KVAL(keysym)]] = k;
148 		}
149 	}
150 }
151 
152 /*
153  * Generate ebcdic -> ascii translation table from kbd_data.
154  */
155 void
156 kbd_ebcasc(struct kbd_data *kbd, unsigned char *ebcasc)
157 {
158 	unsigned short *keymap, keysym;
159 	int i, j, k;
160 
161 	memset(ebcasc, ' ', 256);
162 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
163 		keymap = kbd->key_maps[i];
164 		if (!keymap)
165 			continue;
166 		for (j = 0; j < NR_KEYS; j++) {
167 			keysym = keymap[j];
168 			k = ((i & 1) << 7) + j;
169 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
170 			    KTYP(keysym) == (KT_LETTER | 0xf0))
171 				ebcasc[k] = KVAL(keysym);
172 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
173 				ebcasc[k] = ret_diacr[KVAL(keysym)];
174 		}
175 	}
176 }
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  */
185 static unsigned char
186 handle_diacr(struct kbd_data *kbd, unsigned char 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->tty, d);
203 	return ch;
204 }
205 
206 /*
207  * Handle dead key.
208  */
209 static void
210 k_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  */
219 static void
220 k_self(struct kbd_data *kbd, unsigned char value)
221 {
222 	if (kbd->diacr)
223 		value = handle_diacr(kbd, value);
224 	kbd_put_queue(kbd->tty, value);
225 }
226 
227 /*
228  * Special key handlers
229  */
230 static void
231 k_ignore(struct kbd_data *kbd, unsigned char value)
232 {
233 }
234 
235 /*
236  * Function key handler.
237  */
238 static void
239 k_fn(struct kbd_data *kbd, unsigned char value)
240 {
241 	if (kbd->func_table[value])
242 		kbd_puts_queue(kbd->tty, kbd->func_table[value]);
243 }
244 
245 static void
246 k_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  */
259 static void
260 to_utf8(struct tty_struct *tty, ushort c)
261 {
262 	if (c < 0x80)
263 		/*  0******* */
264 		kbd_put_queue(tty, c);
265 	else if (c < 0x800) {
266 		/* 110***** 10****** */
267 		kbd_put_queue(tty, 0xc0 | (c >> 6));
268 		kbd_put_queue(tty, 0x80 | (c & 0x3f));
269 	} else {
270 		/* 1110**** 10****** 10****** */
271 		kbd_put_queue(tty, 0xe0 | (c >> 12));
272 		kbd_put_queue(tty, 0x80 | ((c >> 6) & 0x3f));
273 		kbd_put_queue(tty, 0x80 | (c & 0x3f));
274 	}
275 }
276 
277 /*
278  * Process keycode.
279  */
280 void
281 kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
282 {
283 	unsigned short keysym;
284 	unsigned char type, value;
285 
286 	if (!kbd || !kbd->tty)
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, 0, kbd->tty);
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->tty, keysym);
327 }
328 
329 /*
330  * Ioctl stuff.
331  */
332 static int
333 do_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] = 0;
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 = (ushort *) 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 
404 static int
405 do_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 		len = strnlen_user(u_kbs->kb_string,
438 				   sizeof(u_kbs->kb_string) - 1);
439 		if (!len)
440 			return -EFAULT;
441 		if (len > sizeof(u_kbs->kb_string) - 1)
442 			return -EINVAL;
443 		p = kmalloc(len + 1, GFP_KERNEL);
444 		if (!p)
445 			return -ENOMEM;
446 		if (copy_from_user(p, u_kbs->kb_string, len)) {
447 			kfree(p);
448 			return -EFAULT;
449 		}
450 		p[len] = 0;
451 		kfree(kbd->func_table[kb_func]);
452 		kbd->func_table[kb_func] = p;
453 		break;
454 	}
455 	return 0;
456 }
457 
458 int
459 kbd_ioctl(struct kbd_data *kbd, struct file *file,
460 	  unsigned int cmd, unsigned long arg)
461 {
462 	struct kbdiacrs __user *a;
463 	void __user *argp;
464 	int ct, perm;
465 
466 	argp = (void __user *)arg;
467 
468 	/*
469 	 * To have permissions to do most of the vt ioctls, we either have
470 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
471 	 */
472 	perm = current->signal->tty == kbd->tty || capable(CAP_SYS_TTY_CONFIG);
473 	switch (cmd) {
474 	case KDGKBTYPE:
475 		return put_user(KB_101, (char __user *)argp);
476 	case KDGKBENT:
477 	case KDSKBENT:
478 		return do_kdsk_ioctl(kbd, argp, cmd, perm);
479 	case KDGKBSENT:
480 	case KDSKBSENT:
481 		return do_kdgkb_ioctl(kbd, argp, cmd, perm);
482 	case KDGKBDIACR:
483 		a = argp;
484 
485 		if (put_user(kbd->accent_table_size, &a->kb_cnt))
486 			return -EFAULT;
487 		ct = kbd->accent_table_size;
488 		if (copy_to_user(a->kbdiacr, kbd->accent_table,
489 				 ct * sizeof(struct kbdiacr)))
490 			return -EFAULT;
491 		return 0;
492 	case KDSKBDIACR:
493 		a = argp;
494 		if (!perm)
495 			return -EPERM;
496 		if (get_user(ct, &a->kb_cnt))
497 			return -EFAULT;
498 		if (ct >= MAX_DIACR)
499 			return -EINVAL;
500 		kbd->accent_table_size = ct;
501 		if (copy_from_user(kbd->accent_table, a->kbdiacr,
502 				   ct * sizeof(struct kbdiacr)))
503 			return -EFAULT;
504 		return 0;
505 	default:
506 		return -ENOIOCTLCMD;
507 	}
508 }
509 
510 EXPORT_SYMBOL(kbd_ioctl);
511 EXPORT_SYMBOL(kbd_ascebc);
512 EXPORT_SYMBOL(kbd_free);
513 EXPORT_SYMBOL(kbd_alloc);
514 EXPORT_SYMBOL(kbd_keycode);
515