selection.c revision 55db4c64eddf37e31279ec15fe90314713bc9cfa 
1/*
2 * This module exports the functions:
3 *
4 *     'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
5 *     'void clear_selection(void)'
6 *     'int paste_selection(struct tty_struct *)'
7 *     'int sel_loadlut(char __user *)'
8 *
9 * Now that /dev/vcs exists, most of this can disappear again.
10 */
11
12#include <linux/module.h>
13#include <linux/tty.h>
14#include <linux/sched.h>
15#include <linux/mm.h>
16#include <linux/slab.h>
17#include <linux/types.h>
18
19#include <asm/uaccess.h>
20
21#include <linux/kbd_kern.h>
22#include <linux/vt_kern.h>
23#include <linux/consolemap.h>
24#include <linux/selection.h>
25#include <linux/tiocl.h>
26#include <linux/console.h>
27
28/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
29#define isspace(c)	((c) == ' ')
30
31extern void poke_blanked_console(void);
32
33/* Variables for selection control. */
34/* Use a dynamic buffer, instead of static (Dec 1994) */
35struct vc_data *sel_cons;		/* must not be deallocated */
36static int use_unicode;
37static volatile int sel_start = -1; 	/* cleared by clear_selection */
38static int sel_end;
39static int sel_buffer_lth;
40static char *sel_buffer;
41
42/* clear_selection, highlight and highlight_pointer can be called
43   from interrupt (via scrollback/front) */
44
45/* set reverse video on characters s-e of console with selection. */
46static inline void highlight(const int s, const int e)
47{
48	invert_screen(sel_cons, s, e-s+2, 1);
49}
50
51/* use complementary color to show the pointer */
52static inline void highlight_pointer(const int where)
53{
54	complement_pos(sel_cons, where);
55}
56
57static u16
58sel_pos(int n)
59{
60	return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
61				use_unicode);
62}
63
64/* remove the current selection highlight, if any,
65   from the console holding the selection. */
66void
67clear_selection(void) {
68	highlight_pointer(-1); /* hide the pointer */
69	if (sel_start != -1) {
70		highlight(sel_start, sel_end);
71		sel_start = -1;
72	}
73}
74
75/*
76 * User settable table: what characters are to be considered alphabetic?
77 * 256 bits
78 */
79static u32 inwordLut[8]={
80  0x00000000, /* control chars     */
81  0x03FF0000, /* digits            */
82  0x87FFFFFE, /* uppercase and '_' */
83  0x07FFFFFE, /* lowercase         */
84  0x00000000,
85  0x00000000,
86  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
87  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
88};
89
90static inline int inword(const u16 c) {
91	return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
92}
93
94/* set inwordLut contents. Invoked by ioctl(). */
95int sel_loadlut(char __user *p)
96{
97	return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
98}
99
100/* does screen address p correspond to character at LH/RH edge of screen? */
101static inline int atedge(const int p, int size_row)
102{
103	return (!(p % size_row)	|| !((p + 2) % size_row));
104}
105
106/* constrain v such that v <= u */
107static inline unsigned short limit(const unsigned short v, const unsigned short u)
108{
109	return (v > u) ? u : v;
110}
111
112/* stores the char in UTF8 and returns the number of bytes used (1-3) */
113static int store_utf8(u16 c, char *p)
114{
115	if (c < 0x80) {
116		/*  0******* */
117		p[0] = c;
118		return 1;
119	} else if (c < 0x800) {
120		/* 110***** 10****** */
121		p[0] = 0xc0 | (c >> 6);
122		p[1] = 0x80 | (c & 0x3f);
123		return 2;
124    	} else {
125		/* 1110**** 10****** 10****** */
126		p[0] = 0xe0 | (c >> 12);
127		p[1] = 0x80 | ((c >> 6) & 0x3f);
128		p[2] = 0x80 | (c & 0x3f);
129		return 3;
130    	}
131}
132
133/* set the current selection. Invoked by ioctl() or by kernel code. */
134int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
135{
136	struct vc_data *vc = vc_cons[fg_console].d;
137	int sel_mode, new_sel_start, new_sel_end, spc;
138	char *bp, *obp;
139	int i, ps, pe, multiplier;
140	u16 c;
141	struct kbd_struct *kbd = kbd_table + fg_console;
142
143	poke_blanked_console();
144
145	{ unsigned short xs, ys, xe, ye;
146
147	  if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
148		return -EFAULT;
149	  __get_user(xs, &sel->xs);
150	  __get_user(ys, &sel->ys);
151	  __get_user(xe, &sel->xe);
152	  __get_user(ye, &sel->ye);
153	  __get_user(sel_mode, &sel->sel_mode);
154	  xs--; ys--; xe--; ye--;
155	  xs = limit(xs, vc->vc_cols - 1);
156	  ys = limit(ys, vc->vc_rows - 1);
157	  xe = limit(xe, vc->vc_cols - 1);
158	  ye = limit(ye, vc->vc_rows - 1);
159	  ps = ys * vc->vc_size_row + (xs << 1);
160	  pe = ye * vc->vc_size_row + (xe << 1);
161
162	  if (sel_mode == TIOCL_SELCLEAR) {
163	      /* useful for screendump without selection highlights */
164	      clear_selection();
165	      return 0;
166	  }
167
168	  if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
169	      mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
170	      return 0;
171	  }
172        }
173
174	if (ps > pe)	/* make sel_start <= sel_end */
175	{
176		int tmp = ps;
177		ps = pe;
178		pe = tmp;
179	}
180
181	if (sel_cons != vc_cons[fg_console].d) {
182		clear_selection();
183		sel_cons = vc_cons[fg_console].d;
184	}
185	use_unicode = kbd && kbd->kbdmode == VC_UNICODE;
186
187	switch (sel_mode)
188	{
189		case TIOCL_SELCHAR:	/* character-by-character selection */
190			new_sel_start = ps;
191			new_sel_end = pe;
192			break;
193		case TIOCL_SELWORD:	/* word-by-word selection */
194			spc = isspace(sel_pos(ps));
195			for (new_sel_start = ps; ; ps -= 2)
196			{
197				if ((spc && !isspace(sel_pos(ps))) ||
198				    (!spc && !inword(sel_pos(ps))))
199					break;
200				new_sel_start = ps;
201				if (!(ps % vc->vc_size_row))
202					break;
203			}
204			spc = isspace(sel_pos(pe));
205			for (new_sel_end = pe; ; pe += 2)
206			{
207				if ((spc && !isspace(sel_pos(pe))) ||
208				    (!spc && !inword(sel_pos(pe))))
209					break;
210				new_sel_end = pe;
211				if (!((pe + 2) % vc->vc_size_row))
212					break;
213			}
214			break;
215		case TIOCL_SELLINE:	/* line-by-line selection */
216			new_sel_start = ps - ps % vc->vc_size_row;
217			new_sel_end = pe + vc->vc_size_row
218				    - pe % vc->vc_size_row - 2;
219			break;
220		case TIOCL_SELPOINTER:
221			highlight_pointer(pe);
222			return 0;
223		default:
224			return -EINVAL;
225	}
226
227	/* remove the pointer */
228	highlight_pointer(-1);
229
230	/* select to end of line if on trailing space */
231	if (new_sel_end > new_sel_start &&
232		!atedge(new_sel_end, vc->vc_size_row) &&
233		isspace(sel_pos(new_sel_end))) {
234		for (pe = new_sel_end + 2; ; pe += 2)
235			if (!isspace(sel_pos(pe)) ||
236			    atedge(pe, vc->vc_size_row))
237				break;
238		if (isspace(sel_pos(pe)))
239			new_sel_end = pe;
240	}
241	if (sel_start == -1)	/* no current selection */
242		highlight(new_sel_start, new_sel_end);
243	else if (new_sel_start == sel_start)
244	{
245		if (new_sel_end == sel_end)	/* no action required */
246			return 0;
247		else if (new_sel_end > sel_end)	/* extend to right */
248			highlight(sel_end + 2, new_sel_end);
249		else				/* contract from right */
250			highlight(new_sel_end + 2, sel_end);
251	}
252	else if (new_sel_end == sel_end)
253	{
254		if (new_sel_start < sel_start)	/* extend to left */
255			highlight(new_sel_start, sel_start - 2);
256		else				/* contract from left */
257			highlight(sel_start, new_sel_start - 2);
258	}
259	else	/* some other case; start selection from scratch */
260	{
261		clear_selection();
262		highlight(new_sel_start, new_sel_end);
263	}
264	sel_start = new_sel_start;
265	sel_end = new_sel_end;
266
267	/* Allocate a new buffer before freeing the old one ... */
268	multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
269	bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
270	if (!bp) {
271		printk(KERN_WARNING "selection: kmalloc() failed\n");
272		clear_selection();
273		return -ENOMEM;
274	}
275	kfree(sel_buffer);
276	sel_buffer = bp;
277
278	obp = bp;
279	for (i = sel_start; i <= sel_end; i += 2) {
280		c = sel_pos(i);
281		if (use_unicode)
282			bp += store_utf8(c, bp);
283		else
284			*bp++ = c;
285		if (!isspace(c))
286			obp = bp;
287		if (! ((i + 2) % vc->vc_size_row)) {
288			/* strip trailing blanks from line and add newline,
289			   unless non-space at end of line. */
290			if (obp != bp) {
291				bp = obp;
292				*bp++ = '\r';
293			}
294			obp = bp;
295		}
296	}
297	sel_buffer_lth = bp - sel_buffer;
298	return 0;
299}
300
301/* Insert the contents of the selection buffer into the
302 * queue of the tty associated with the current console.
303 * Invoked by ioctl().
304 */
305int paste_selection(struct tty_struct *tty)
306{
307	struct vc_data *vc = tty->driver_data;
308	int	pasted = 0;
309	unsigned int count;
310	struct  tty_ldisc *ld;
311	DECLARE_WAITQUEUE(wait, current);
312
313	/* always called with BTM from vt_ioctl */
314	WARN_ON(!tty_locked());
315
316	console_lock();
317	poke_blanked_console();
318	console_unlock();
319
320	ld = tty_ldisc_ref(tty);
321	if (!ld) {
322		tty_unlock();
323		ld = tty_ldisc_ref_wait(tty);
324		tty_lock();
325	}
326
327	add_wait_queue(&vc->paste_wait, &wait);
328	while (sel_buffer && sel_buffer_lth > pasted) {
329		set_current_state(TASK_INTERRUPTIBLE);
330		if (test_bit(TTY_THROTTLED, &tty->flags)) {
331			schedule();
332			continue;
333		}
334		count = sel_buffer_lth - pasted;
335		count = min(count, tty->receive_room);
336		tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
337								NULL, count);
338		pasted += count;
339	}
340	remove_wait_queue(&vc->paste_wait, &wait);
341	__set_current_state(TASK_RUNNING);
342
343	tty_ldisc_deref(ld);
344	return 0;
345}
346