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#include <linux/tty_flip.h>
28
29/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
30#define isspace(c)	((c) == ' ')
31
32extern void poke_blanked_console(void);
33
34/* FIXME: all this needs locking */
35/* Variables for selection control. */
36/* Use a dynamic buffer, instead of static (Dec 1994) */
37struct vc_data *sel_cons;		/* must not be deallocated */
38static int use_unicode;
39static volatile int sel_start = -1; 	/* cleared by clear_selection */
40static int sel_end;
41static int sel_buffer_lth;
42static char *sel_buffer;
43
44/* clear_selection, highlight and highlight_pointer can be called
45   from interrupt (via scrollback/front) */
46
47/* set reverse video on characters s-e of console with selection. */
48static inline void highlight(const int s, const int e)
49{
50	invert_screen(sel_cons, s, e-s+2, 1);
51}
52
53/* use complementary color to show the pointer */
54static inline void highlight_pointer(const int where)
55{
56	complement_pos(sel_cons, where);
57}
58
59static u16
60sel_pos(int n)
61{
62	return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
63				use_unicode);
64}
65
66/**
67 *	clear_selection		-	remove current selection
68 *
69 *	Remove the current selection highlight, if any from the console
70 *	holding the selection. The caller must hold the console lock.
71 */
72void clear_selection(void)
73{
74	highlight_pointer(-1); /* hide the pointer */
75	if (sel_start != -1) {
76		highlight(sel_start, sel_end);
77		sel_start = -1;
78	}
79}
80
81/*
82 * User settable table: what characters are to be considered alphabetic?
83 * 256 bits. Locked by the console lock.
84 */
85static u32 inwordLut[8]={
86  0x00000000, /* control chars     */
87  0x03FF0000, /* digits            */
88  0x87FFFFFE, /* uppercase and '_' */
89  0x07FFFFFE, /* lowercase         */
90  0x00000000,
91  0x00000000,
92  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
93  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
94};
95
96static inline int inword(const u16 c) {
97	return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
98}
99
100/**
101 *	set loadlut		-	load the LUT table
102 *	@p: user table
103 *
104 *	Load the LUT table from user space. The caller must hold the console
105 *	lock. Make a temporary copy so a partial update doesn't make a mess.
106 */
107int sel_loadlut(char __user *p)
108{
109	u32 tmplut[8];
110	if (copy_from_user(tmplut, (u32 __user *)(p+4), 32))
111		return -EFAULT;
112	memcpy(inwordLut, tmplut, 32);
113	return 0;
114}
115
116/* does screen address p correspond to character at LH/RH edge of screen? */
117static inline int atedge(const int p, int size_row)
118{
119	return (!(p % size_row)	|| !((p + 2) % size_row));
120}
121
122/* constrain v such that v <= u */
123static inline unsigned short limit(const unsigned short v, const unsigned short u)
124{
125	return (v > u) ? u : v;
126}
127
128/* stores the char in UTF8 and returns the number of bytes used (1-3) */
129static int store_utf8(u16 c, char *p)
130{
131	if (c < 0x80) {
132		/*  0******* */
133		p[0] = c;
134		return 1;
135	} else if (c < 0x800) {
136		/* 110***** 10****** */
137		p[0] = 0xc0 | (c >> 6);
138		p[1] = 0x80 | (c & 0x3f);
139		return 2;
140    	} else {
141		/* 1110**** 10****** 10****** */
142		p[0] = 0xe0 | (c >> 12);
143		p[1] = 0x80 | ((c >> 6) & 0x3f);
144		p[2] = 0x80 | (c & 0x3f);
145		return 3;
146    	}
147}
148
149/**
150 *	set_selection		- 	set the current selection.
151 *	@sel: user selection info
152 *	@tty: the console tty
153 *
154 *	Invoked by the ioctl handle for the vt layer.
155 *
156 *	The entire selection process is managed under the console_lock. It's
157 *	 a lot under the lock but its hardly a performance path
158 */
159int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
160{
161	struct vc_data *vc = vc_cons[fg_console].d;
162	int sel_mode, new_sel_start, new_sel_end, spc;
163	char *bp, *obp;
164	int i, ps, pe, multiplier;
165	u16 c;
166	int mode;
167
168	poke_blanked_console();
169
170	{ unsigned short xs, ys, xe, ye;
171
172	  if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
173		return -EFAULT;
174	  __get_user(xs, &sel->xs);
175	  __get_user(ys, &sel->ys);
176	  __get_user(xe, &sel->xe);
177	  __get_user(ye, &sel->ye);
178	  __get_user(sel_mode, &sel->sel_mode);
179	  xs--; ys--; xe--; ye--;
180	  xs = limit(xs, vc->vc_cols - 1);
181	  ys = limit(ys, vc->vc_rows - 1);
182	  xe = limit(xe, vc->vc_cols - 1);
183	  ye = limit(ye, vc->vc_rows - 1);
184	  ps = ys * vc->vc_size_row + (xs << 1);
185	  pe = ye * vc->vc_size_row + (xe << 1);
186
187	  if (sel_mode == TIOCL_SELCLEAR) {
188	      /* useful for screendump without selection highlights */
189	      clear_selection();
190	      return 0;
191	  }
192
193	  if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
194	      mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
195	      return 0;
196	  }
197        }
198
199	if (ps > pe)	/* make sel_start <= sel_end */
200	{
201		int tmp = ps;
202		ps = pe;
203		pe = tmp;
204	}
205
206	if (sel_cons != vc_cons[fg_console].d) {
207		clear_selection();
208		sel_cons = vc_cons[fg_console].d;
209	}
210	mode = vt_do_kdgkbmode(fg_console);
211	if (mode == K_UNICODE)
212		use_unicode = 1;
213	else
214		use_unicode = 0;
215
216	switch (sel_mode)
217	{
218		case TIOCL_SELCHAR:	/* character-by-character selection */
219			new_sel_start = ps;
220			new_sel_end = pe;
221			break;
222		case TIOCL_SELWORD:	/* word-by-word selection */
223			spc = isspace(sel_pos(ps));
224			for (new_sel_start = ps; ; ps -= 2)
225			{
226				if ((spc && !isspace(sel_pos(ps))) ||
227				    (!spc && !inword(sel_pos(ps))))
228					break;
229				new_sel_start = ps;
230				if (!(ps % vc->vc_size_row))
231					break;
232			}
233			spc = isspace(sel_pos(pe));
234			for (new_sel_end = pe; ; pe += 2)
235			{
236				if ((spc && !isspace(sel_pos(pe))) ||
237				    (!spc && !inword(sel_pos(pe))))
238					break;
239				new_sel_end = pe;
240				if (!((pe + 2) % vc->vc_size_row))
241					break;
242			}
243			break;
244		case TIOCL_SELLINE:	/* line-by-line selection */
245			new_sel_start = ps - ps % vc->vc_size_row;
246			new_sel_end = pe + vc->vc_size_row
247				    - pe % vc->vc_size_row - 2;
248			break;
249		case TIOCL_SELPOINTER:
250			highlight_pointer(pe);
251			return 0;
252		default:
253			return -EINVAL;
254	}
255
256	/* remove the pointer */
257	highlight_pointer(-1);
258
259	/* select to end of line if on trailing space */
260	if (new_sel_end > new_sel_start &&
261		!atedge(new_sel_end, vc->vc_size_row) &&
262		isspace(sel_pos(new_sel_end))) {
263		for (pe = new_sel_end + 2; ; pe += 2)
264			if (!isspace(sel_pos(pe)) ||
265			    atedge(pe, vc->vc_size_row))
266				break;
267		if (isspace(sel_pos(pe)))
268			new_sel_end = pe;
269	}
270	if (sel_start == -1)	/* no current selection */
271		highlight(new_sel_start, new_sel_end);
272	else if (new_sel_start == sel_start)
273	{
274		if (new_sel_end == sel_end)	/* no action required */
275			return 0;
276		else if (new_sel_end > sel_end)	/* extend to right */
277			highlight(sel_end + 2, new_sel_end);
278		else				/* contract from right */
279			highlight(new_sel_end + 2, sel_end);
280	}
281	else if (new_sel_end == sel_end)
282	{
283		if (new_sel_start < sel_start)	/* extend to left */
284			highlight(new_sel_start, sel_start - 2);
285		else				/* contract from left */
286			highlight(sel_start, new_sel_start - 2);
287	}
288	else	/* some other case; start selection from scratch */
289	{
290		clear_selection();
291		highlight(new_sel_start, new_sel_end);
292	}
293	sel_start = new_sel_start;
294	sel_end = new_sel_end;
295
296	/* Allocate a new buffer before freeing the old one ... */
297	multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
298	bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
299	if (!bp) {
300		printk(KERN_WARNING "selection: kmalloc() failed\n");
301		clear_selection();
302		return -ENOMEM;
303	}
304	kfree(sel_buffer);
305	sel_buffer = bp;
306
307	obp = bp;
308	for (i = sel_start; i <= sel_end; i += 2) {
309		c = sel_pos(i);
310		if (use_unicode)
311			bp += store_utf8(c, bp);
312		else
313			*bp++ = c;
314		if (!isspace(c))
315			obp = bp;
316		if (! ((i + 2) % vc->vc_size_row)) {
317			/* strip trailing blanks from line and add newline,
318			   unless non-space at end of line. */
319			if (obp != bp) {
320				bp = obp;
321				*bp++ = '\r';
322			}
323			obp = bp;
324		}
325	}
326	sel_buffer_lth = bp - sel_buffer;
327	return 0;
328}
329
330/* Insert the contents of the selection buffer into the
331 * queue of the tty associated with the current console.
332 * Invoked by ioctl().
333 *
334 * Locking: called without locks. Calls the ldisc wrongly with
335 * unsafe methods,
336 */
337int paste_selection(struct tty_struct *tty)
338{
339	struct vc_data *vc = tty->driver_data;
340	int	pasted = 0;
341	unsigned int count;
342	struct  tty_ldisc *ld;
343	DECLARE_WAITQUEUE(wait, current);
344
345	console_lock();
346	poke_blanked_console();
347	console_unlock();
348
349	ld = tty_ldisc_ref_wait(tty);
350	tty_buffer_lock_exclusive(&vc->port);
351
352	add_wait_queue(&vc->paste_wait, &wait);
353	while (sel_buffer && sel_buffer_lth > pasted) {
354		set_current_state(TASK_INTERRUPTIBLE);
355		if (test_bit(TTY_THROTTLED, &tty->flags)) {
356			schedule();
357			continue;
358		}
359		count = sel_buffer_lth - pasted;
360		count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
361					      count);
362		pasted += count;
363	}
364	remove_wait_queue(&vc->paste_wait, &wait);
365	__set_current_state(TASK_RUNNING);
366
367	tty_buffer_unlock_exclusive(&vc->port);
368	tty_ldisc_deref(ld);
369	return 0;
370}
371