xref: /linux/drivers/s390/char/keyboard.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641) 
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 = kmalloc(sizeof(struct kbd_data), GFP_KERNEL);
54 	if (!kbd)
55 		goto out;
56 	memset(kbd, 0, sizeof(struct kbd_data));
57 	kbd->key_maps = kmalloc(sizeof(key_maps), GFP_KERNEL);
58 	if (!key_maps)
59 		goto out_kbd;
60 	memset(kbd->key_maps, 0, sizeof(key_maps));
61 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
62 		if (key_maps[i]) {
63 			kbd->key_maps[i] =
64 				kmalloc(sizeof(u_short)*NR_KEYS, GFP_KERNEL);
65 			if (!kbd->key_maps[i])
66 				goto out_maps;
67 			memcpy(kbd->key_maps[i], key_maps[i],
68 			       sizeof(u_short)*NR_KEYS);
69 		}
70 	}
71 	kbd->func_table = kmalloc(sizeof(func_table), GFP_KERNEL);
72 	if (!kbd->func_table)
73 		goto out_maps;
74 	memset(kbd->func_table, 0, sizeof(func_table));
75 	for (i = 0; i < ARRAY_SIZE(func_table); i++) {
76 		if (func_table[i]) {
77 			len = strlen(func_table[i]) + 1;
78 			kbd->func_table[i] = kmalloc(len, GFP_KERNEL);
79 			if (!kbd->func_table[i])
80 				goto out_func;
81 			memcpy(kbd->func_table[i], func_table[i], len);
82 		}
83 	}
84 	kbd->fn_handler =
85 		kmalloc(sizeof(fn_handler_fn *) * NR_FN_HANDLER, GFP_KERNEL);
86 	if (!kbd->fn_handler)
87 		goto out_func;
88 	memset(kbd->fn_handler, 0, sizeof(fn_handler_fn *) * NR_FN_HANDLER);
89 	kbd->accent_table =
90 		kmalloc(sizeof(struct kbdiacr)*MAX_DIACR, GFP_KERNEL);
91 	if (!kbd->accent_table)
92 		goto out_fn_handler;
93 	memcpy(kbd->accent_table, accent_table,
94 	       sizeof(struct kbdiacr)*MAX_DIACR);
95 	kbd->accent_table_size = accent_table_size;
96 	return kbd;
97 
98 out_fn_handler:
99 	kfree(kbd->fn_handler);
100 out_func:
101 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
102 		kfree(kbd->func_table[i]);
103 	kfree(kbd->func_table);
104 out_maps:
105 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
106 		kfree(kbd->key_maps[i]);
107 	kfree(kbd->key_maps);
108 out_kbd:
109 	kfree(kbd);
110 out:
111 	return 0;
112 }
113 
114 void
115 kbd_free(struct kbd_data *kbd)
116 {
117 	int i;
118 
119 	kfree(kbd->accent_table);
120 	kfree(kbd->fn_handler);
121 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
122 		kfree(kbd->func_table[i]);
123 	kfree(kbd->func_table);
124 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
125 		kfree(kbd->key_maps[i]);
126 	kfree(kbd->key_maps);
127 	kfree(kbd);
128 }
129 
130 /*
131  * Generate ascii -> ebcdic translation table from kbd_data.
132  */
133 void
134 kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
135 {
136 	unsigned short *keymap, keysym;
137 	int i, j, k;
138 
139 	memset(ascebc, 0x40, 256);
140 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
141 		keymap = kbd->key_maps[i];
142 		if (!keymap)
143 			continue;
144 		for (j = 0; j < NR_KEYS; j++) {
145 			k = ((i & 1) << 7) + j;
146 			keysym = keymap[j];
147 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
148 			    KTYP(keysym) == (KT_LETTER | 0xf0))
149 				ascebc[KVAL(keysym)] = k;
150 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
151 				ascebc[ret_diacr[KVAL(keysym)]] = k;
152 		}
153 	}
154 }
155 
156 /*
157  * Generate ebcdic -> ascii translation table from kbd_data.
158  */
159 void
160 kbd_ebcasc(struct kbd_data *kbd, unsigned char *ebcasc)
161 {
162 	unsigned short *keymap, keysym;
163 	int i, j, k;
164 
165 	memset(ebcasc, ' ', 256);
166 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
167 		keymap = kbd->key_maps[i];
168 		if (!keymap)
169 			continue;
170 		for (j = 0; j < NR_KEYS; j++) {
171 			keysym = keymap[j];
172 			k = ((i & 1) << 7) + j;
173 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
174 			    KTYP(keysym) == (KT_LETTER | 0xf0))
175 				ebcasc[k] = KVAL(keysym);
176 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
177 				ebcasc[k] = ret_diacr[KVAL(keysym)];
178 		}
179 	}
180 }
181 
182 /*
183  * We have a combining character DIACR here, followed by the character CH.
184  * If the combination occurs in the table, return the corresponding value.
185  * Otherwise, if CH is a space or equals DIACR, return DIACR.
186  * Otherwise, conclude that DIACR was not combining after all,
187  * queue it and return CH.
188  */
189 static unsigned char
190 handle_diacr(struct kbd_data *kbd, unsigned char ch)
191 {
192 	int i, d;
193 
194 	d = kbd->diacr;
195 	kbd->diacr = 0;
196 
197 	for (i = 0; i < kbd->accent_table_size; i++) {
198 		if (kbd->accent_table[i].diacr == d &&
199 		    kbd->accent_table[i].base == ch)
200 			return kbd->accent_table[i].result;
201 	}
202 
203 	if (ch == ' ' || ch == d)
204 		return d;
205 
206 	kbd_put_queue(kbd->tty, d);
207 	return ch;
208 }
209 
210 /*
211  * Handle dead key.
212  */
213 static void
214 k_dead(struct kbd_data *kbd, unsigned char value)
215 {
216 	value = ret_diacr[value];
217 	kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
218 }
219 
220 /*
221  * Normal character handler.
222  */
223 static void
224 k_self(struct kbd_data *kbd, unsigned char value)
225 {
226 	if (kbd->diacr)
227 		value = handle_diacr(kbd, value);
228 	kbd_put_queue(kbd->tty, value);
229 }
230 
231 /*
232  * Special key handlers
233  */
234 static void
235 k_ignore(struct kbd_data *kbd, unsigned char value)
236 {
237 }
238 
239 /*
240  * Function key handler.
241  */
242 static void
243 k_fn(struct kbd_data *kbd, unsigned char value)
244 {
245 	if (kbd->func_table[value])
246 		kbd_puts_queue(kbd->tty, kbd->func_table[value]);
247 }
248 
249 static void
250 k_spec(struct kbd_data *kbd, unsigned char value)
251 {
252 	if (value >= NR_FN_HANDLER)
253 		return;
254 	if (kbd->fn_handler[value])
255 		kbd->fn_handler[value](kbd);
256 }
257 
258 /*
259  * Put utf8 character to tty flip buffer.
260  * UTF-8 is defined for words of up to 31 bits,
261  * but we need only 16 bits here
262  */
263 static void
264 to_utf8(struct tty_struct *tty, ushort c)
265 {
266 	if (c < 0x80)
267 		/*  0******* */
268 		kbd_put_queue(tty, c);
269 	else if (c < 0x800) {
270 		/* 110***** 10****** */
271 		kbd_put_queue(tty, 0xc0 | (c >> 6));
272 		kbd_put_queue(tty, 0x80 | (c & 0x3f));
273 	} else {
274 		/* 1110**** 10****** 10****** */
275 		kbd_put_queue(tty, 0xe0 | (c >> 12));
276 		kbd_put_queue(tty, 0x80 | ((c >> 6) & 0x3f));
277 		kbd_put_queue(tty, 0x80 | (c & 0x3f));
278 	}
279 }
280 
281 /*
282  * Process keycode.
283  */
284 void
285 kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
286 {
287 	unsigned short keysym;
288 	unsigned char type, value;
289 
290 	if (!kbd || !kbd->tty)
291 		return;
292 
293 	if (keycode >= 384)
294 		keysym = kbd->key_maps[5][keycode - 384];
295 	else if (keycode >= 256)
296 		keysym = kbd->key_maps[4][keycode - 256];
297 	else if (keycode >= 128)
298 		keysym = kbd->key_maps[1][keycode - 128];
299 	else
300 		keysym = kbd->key_maps[0][keycode];
301 
302 	type = KTYP(keysym);
303 	if (type >= 0xf0) {
304 		type -= 0xf0;
305 		if (type == KT_LETTER)
306 			type = KT_LATIN;
307 		value = KVAL(keysym);
308 #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
309 		if (kbd->sysrq) {
310 			if (kbd->sysrq == K(KT_LATIN, '-')) {
311 				kbd->sysrq = 0;
312 				handle_sysrq(value, 0, kbd->tty);
313 				return;
314 			}
315 			if (value == '-') {
316 				kbd->sysrq = K(KT_LATIN, '-');
317 				return;
318 			}
319 			/* Incomplete sysrq sequence. */
320 			(*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
321 			kbd->sysrq = 0;
322 		} else if ((type == KT_LATIN && value == '^') ||
323 			   (type == KT_DEAD && ret_diacr[value] == '^')) {
324 			kbd->sysrq = K(type, value);
325 			return;
326 		}
327 #endif
328 		(*k_handler[type])(kbd, value);
329 	} else
330 		to_utf8(kbd->tty, keysym);
331 }
332 
333 /*
334  * Ioctl stuff.
335  */
336 static int
337 do_kdsk_ioctl(struct kbd_data *kbd, struct kbentry __user *user_kbe,
338 	      int cmd, int perm)
339 {
340 	struct kbentry tmp;
341 	ushort *key_map, val, ov;
342 
343 	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
344 		return -EFAULT;
345 #if NR_KEYS < 256
346 	if (tmp.kb_index >= NR_KEYS)
347 		return -EINVAL;
348 #endif
349 #if MAX_NR_KEYMAPS < 256
350 	if (tmp.kb_table >= MAX_NR_KEYMAPS)
351 		return -EINVAL;
352 #endif
353 
354 	switch (cmd) {
355 	case KDGKBENT:
356 		key_map = kbd->key_maps[tmp.kb_table];
357 		if (key_map) {
358 		    val = U(key_map[tmp.kb_index]);
359 		    if (KTYP(val) >= KBD_NR_TYPES)
360 			val = K_HOLE;
361 		} else
362 		    val = (tmp.kb_index ? K_HOLE : K_NOSUCHMAP);
363 		return put_user(val, &user_kbe->kb_value);
364 	case KDSKBENT:
365 		if (!perm)
366 			return -EPERM;
367 		if (!tmp.kb_index && tmp.kb_value == K_NOSUCHMAP) {
368 			/* disallocate map */
369 			key_map = kbd->key_maps[tmp.kb_table];
370 			if (key_map) {
371 			    kbd->key_maps[tmp.kb_table] = 0;
372 			    kfree(key_map);
373 			}
374 			break;
375 		}
376 
377 		if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
378 			return -EINVAL;
379 		if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
380 			return -EINVAL;
381 
382 		if (!(key_map = kbd->key_maps[tmp.kb_table])) {
383 			int j;
384 
385 			key_map = (ushort *) kmalloc(sizeof(plain_map),
386 						     GFP_KERNEL);
387 			if (!key_map)
388 				return -ENOMEM;
389 			kbd->key_maps[tmp.kb_table] = key_map;
390 			for (j = 0; j < NR_KEYS; j++)
391 				key_map[j] = U(K_HOLE);
392 		}
393 		ov = U(key_map[tmp.kb_index]);
394 		if (tmp.kb_value == ov)
395 			break;	/* nothing to do */
396 		/*
397 		 * Attention Key.
398 		 */
399 		if (((ov == K_SAK) || (tmp.kb_value == K_SAK)) &&
400 		    !capable(CAP_SYS_ADMIN))
401 			return -EPERM;
402 		key_map[tmp.kb_index] = U(tmp.kb_value);
403 		break;
404 	}
405 	return 0;
406 }
407 
408 static int
409 do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
410 	       int cmd, int perm)
411 {
412 	unsigned char kb_func;
413 	char *p;
414 	int len;
415 
416 	/* Get u_kbs->kb_func. */
417 	if (get_user(kb_func, &u_kbs->kb_func))
418 		return -EFAULT;
419 #if MAX_NR_FUNC < 256
420 	if (kb_func >= MAX_NR_FUNC)
421 		return -EINVAL;
422 #endif
423 
424 	switch (cmd) {
425 	case KDGKBSENT:
426 		p = kbd->func_table[kb_func];
427 		if (p) {
428 			len = strlen(p);
429 			if (len >= sizeof(u_kbs->kb_string))
430 				len = sizeof(u_kbs->kb_string) - 1;
431 			if (copy_to_user(u_kbs->kb_string, p, len))
432 				return -EFAULT;
433 		} else
434 			len = 0;
435 		if (put_user('\0', u_kbs->kb_string + len))
436 			return -EFAULT;
437 		break;
438 	case KDSKBSENT:
439 		if (!perm)
440 			return -EPERM;
441 		len = strnlen_user(u_kbs->kb_string,
442 				   sizeof(u_kbs->kb_string) - 1);
443 		p = kmalloc(len, 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