aboutsummaryrefslogtreecommitdiff
path: root/drivers/tty/vt/selection.c
blob: 7a0a12ae54588ce7df5f0bcfcd5f48ac3b7d92ba (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
/*
 * This module exports the functions:
 *
 *     'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
 *     'void clear_selection(void)'
 *     'int paste_selection(struct tty_struct *)'
 *     'int sel_loadlut(char __user *)'
 *
 * Now that /dev/vcs exists, most of this can disappear again.
 */

#include <linux/module.h>
#include <linux/tty.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <asm/uaccess.h>

#include <linux/kbd_kern.h>
#include <linux/vt_kern.h>
#include <linux/consolemap.h>
#include <linux/selection.h>
#include <linux/tiocl.h>
#include <linux/console.h>

/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
#define isspace(c)	((c) == ' ')

extern void poke_blanked_console(void);

/* Variables for selection control. */
/* Use a dynamic buffer, instead of static (Dec 1994) */
struct vc_data *sel_cons;		/* must not be deallocated */
static int use_unicode;
static volatile int sel_start = -1; 	/* cleared by clear_selection */
static int sel_end;
static int sel_buffer_lth;
static char *sel_buffer;

/* clear_selection, highlight and highlight_pointer can be called
   from interrupt (via scrollback/front) */

/* set reverse video on characters s-e of console with selection. */
static inline void highlight(const int s, const int e)
{
	invert_screen(sel_cons, s, e-s+2, 1);
}

/* use complementary color to show the pointer */
static inline void highlight_pointer(const int where)
{
	complement_pos(sel_cons, where);
}

static u16
sel_pos(int n)
{
	return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
				use_unicode);
}

/* remove the current selection highlight, if any,
   from the console holding the selection. */
void
clear_selection(void) {
	highlight_pointer(-1); /* hide the pointer */
	if (sel_start != -1) {
		highlight(sel_start, sel_end);
		sel_start = -1;
	}
}

/*
 * User settable table: what characters are to be considered alphabetic?
 * 256 bits
 */
static u32 inwordLut[8]={
  0x00000000, /* control chars     */
  0x03FF0000, /* digits            */
  0x87FFFFFE, /* uppercase and '_' */
  0x07FFFFFE, /* lowercase         */
  0x00000000,
  0x00000000,
  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
};

static inline int inword(const u16 c) {
	return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
}

/* set inwordLut contents. Invoked by ioctl(). */
int sel_loadlut(char __user *p)
{
	return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
}

/* does screen address p correspond to character at LH/RH edge of screen? */
static inline int atedge(const int p, int size_row)
{
	return (!(p % size_row)	|| !((p + 2) % size_row));
}

/* constrain v such that v <= u */
static inline unsigned short limit(const unsigned short v, const unsigned short u)
{
	return (v > u) ? u : v;
}

/* stores the char in UTF8 and returns the number of bytes used (1-3) */
static int store_utf8(u16 c, char *p)
{
	if (c < 0x80) {
		/*  0******* */
		p[0] = c;
		return 1;
	} else if (c < 0x800) {
		/* 110***** 10****** */
		p[0] = 0xc0 | (c >> 6);
		p[1] = 0x80 | (c & 0x3f);
		return 2;
    	} else {
		/* 1110**** 10****** 10****** */
		p[0] = 0xe0 | (c >> 12);
		p[1] = 0x80 | ((c >> 6) & 0x3f);
		p[2] = 0x80 | (c & 0x3f);
		return 3;
    	}
}

/* set the current selection. Invoked by ioctl() or by kernel code. */
int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
{
	struct vc_data *vc = vc_cons[fg_console].d;
	int sel_mode, new_sel_start, new_sel_end, spc;
	char *bp, *obp;
	int i, ps, pe, multiplier;
	u16 c;
	struct kbd_struct *kbd = kbd_table + fg_console;

	poke_blanked_console();

	{ unsigned short xs, ys, xe, ye;

	  if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
		return -EFAULT;
	  __get_user(xs, &sel->xs);
	  __get_user(ys, &sel->ys);
	  __get_user(xe, &sel->xe);
	  __get_user(ye, &sel->ye);
	  __get_user(sel_mode, &sel->sel_mode);
	  xs--; ys--; xe--; ye--;
	  xs = limit(xs, vc->vc_cols - 1);
	  ys = limit(ys, vc->vc_rows - 1);
	  xe = limit(xe, vc->vc_cols - 1);
	  ye = limit(ye, vc->vc_rows - 1);
	  ps = ys * vc->vc_size_row + (xs << 1);
	  pe = ye * vc->vc_size_row + (xe << 1);

	  if (sel_mode == TIOCL_SELCLEAR) {
	      /* useful for screendump without selection highlights */
	      clear_selection();
	      return 0;
	  }

	  if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
	      mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
	      return 0;
	  }
        }

	if (ps > pe)	/* make sel_start <= sel_end */
	{
		int tmp = ps;
		ps = pe;
		pe = tmp;
	}

	if (sel_cons != vc_cons[fg_console].d) {
		clear_selection();
		sel_cons = vc_cons[fg_console].d;
	}
	use_unicode = kbd && kbd->kbdmode == VC_UNICODE;

	switch (sel_mode)
	{
		case TIOCL_SELCHAR:	/* character-by-character selection */
			new_sel_start = ps;
			new_sel_end = pe;
			break;
		case TIOCL_SELWORD:	/* word-by-word selection */
			spc = isspace(sel_pos(ps));
			for (new_sel_start = ps; ; ps -= 2)
			{
				if ((spc && !isspace(sel_pos(ps))) ||
				    (!spc && !inword(sel_pos(ps))))
					break;
				new_sel_start = ps;
				if (!(ps % vc->vc_size_row))
					break;
			}
			spc = isspace(sel_pos(pe));
			for (new_sel_end = pe; ; pe += 2)
			{
				if ((spc && !isspace(sel_pos(pe))) ||
				    (!spc && !inword(sel_pos(pe))))
					break;
				new_sel_end = pe;
				if (!((pe + 2) % vc->vc_size_row))
					break;
			}
			break;
		case TIOCL_SELLINE:	/* line-by-line selection */
			new_sel_start = ps - ps % vc->vc_size_row;
			new_sel_end = pe + vc->vc_size_row
				    - pe % vc->vc_size_row - 2;
			break;
		case TIOCL_SELPOINTER:
			highlight_pointer(pe);
			return 0;
		default:
			return -EINVAL;
	}

	/* remove the pointer */
	highlight_pointer(-1);

	/* select to end of line if on trailing space */
	if (new_sel_end > new_sel_start &&
		!atedge(new_sel_end, vc->vc_size_row) &&
		isspace(sel_pos(new_sel_end))) {
		for (pe = new_sel_end + 2; ; pe += 2)
			if (!isspace(sel_pos(pe)) ||
			    atedge(pe, vc->vc_size_row))
				break;
		if (isspace(sel_pos(pe)))
			new_sel_end = pe;
	}
	if (sel_start == -1)	/* no current selection */
		highlight(new_sel_start, new_sel_end);
	else if (new_sel_start == sel_start)
	{
		if (new_sel_end == sel_end)	/* no action required */
			return 0;
		else if (new_sel_end > sel_end)	/* extend to right */
			highlight(sel_end + 2, new_sel_end);
		else				/* contract from right */
			highlight(new_sel_end + 2, sel_end);
	}
	else if (new_sel_end == sel_end)
	{
		if (new_sel_start < sel_start)	/* extend to left */
			highlight(new_sel_start, sel_start - 2);
		else				/* contract from left */
			highlight(sel_start, new_sel_start - 2);
	}
	else	/* some other case; start selection from scratch */
	{
		clear_selection();
		highlight(new_sel_start, new_sel_end);
	}
	sel_start = new_sel_start;
	sel_end = new_sel_end;

	/* Allocate a new buffer before freeing the old one ... */
	multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
	bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
	if (!bp) {
		printk(KERN_WARNING "selection: kmalloc() failed\n");
		clear_selection();
		return -ENOMEM;
	}
	kfree(sel_buffer);
	sel_buffer = bp;

	obp = bp;
	for (i = sel_start; i <= sel_end; i += 2) {
		c = sel_pos(i);
		if (use_unicode)
			bp += store_utf8(c, bp);
		else
			*bp++ = c;
		if (!isspace(c))
			obp = bp;
		if (! ((i + 2) % vc->vc_size_row)) {
			/* strip trailing blanks from line and add newline,
			   unless non-space at end of line. */
			if (obp != bp) {
				bp = obp;
				*bp++ = '\r';
			}
			obp = bp;
		}
	}
	sel_buffer_lth = bp - sel_buffer;
	return 0;
}

/* Insert the contents of the selection buffer into the
 * queue of the tty associated with the current console.
 * Invoked by ioctl().
 *
 * Locking: always called with BTM from vt_ioctl
 */
int paste_selection(struct tty_struct *tty)
{
	struct vc_data *vc = tty->driver_data;
	int	pasted = 0;
	unsigned int count;
	struct  tty_ldisc *ld;
	DECLARE_WAITQUEUE(wait, current);


	console_lock();
	poke_blanked_console();
	console_unlock();

	ld = tty_ldisc_ref(tty);
	if (!ld) {
		tty_unlock();
		ld = tty_ldisc_ref_wait(tty);
		tty_lock();
	}

	add_wait_queue(&vc->paste_wait, &wait);
	while (sel_buffer && sel_buffer_lth > pasted) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (test_bit(TTY_THROTTLED, &tty->flags)) {
			schedule();
			continue;
		}
		count = sel_buffer_lth - pasted;
		count = min(count, tty->receive_room);
		tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
								NULL, count);
		pasted += count;
	}
	remove_wait_queue(&vc->paste_wait, &wait);
	__set_current_state(TASK_RUNNING);

	tty_ldisc_deref(ld);
	return 0;
}