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/drivers/char/selection.c

https://bitbucket.org/evzijst/gittest
C | 306 lines | 233 code | 34 blank | 39 comment | 50 complexity | a939cda0b1aac1ede0884b2acb7aed3c MD5 | raw file
  1/*
  2 * linux/drivers/char/selection.c
  3 *
  4 * This module exports the functions:
  5 *
  6 *     'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
  7 *     'void clear_selection(void)'
  8 *     'int paste_selection(struct tty_struct *)'
  9 *     'int sel_loadlut(char __user *)'
 10 *
 11 * Now that /dev/vcs exists, most of this can disappear again.
 12 */
 13
 14#include <linux/module.h>
 15#include <linux/tty.h>
 16#include <linux/sched.h>
 17#include <linux/mm.h>
 18#include <linux/slab.h>
 19#include <linux/types.h>
 20
 21#include <asm/uaccess.h>
 22
 23#include <linux/vt_kern.h>
 24#include <linux/consolemap.h>
 25#include <linux/selection.h>
 26#include <linux/tiocl.h>
 27#include <linux/console.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/* Variables for selection control. */
 35/* Use a dynamic buffer, instead of static (Dec 1994) */
 36struct vc_data *sel_cons;		/* must not be disallocated */
 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 unsigned char
 58sel_pos(int n)
 59{
 60	return inverse_translate(sel_cons, screen_glyph(sel_cons, n));
 61}
 62
 63/* remove the current selection highlight, if any,
 64   from the console holding the selection. */
 65void
 66clear_selection(void) {
 67	highlight_pointer(-1); /* hide the pointer */
 68	if (sel_start != -1) {
 69		highlight(sel_start, sel_end);
 70		sel_start = -1;
 71	}
 72}
 73
 74/*
 75 * User settable table: what characters are to be considered alphabetic?
 76 * 256 bits
 77 */
 78static u32 inwordLut[8]={
 79  0x00000000, /* control chars     */
 80  0x03FF0000, /* digits            */
 81  0x87FFFFFE, /* uppercase and '_' */
 82  0x07FFFFFE, /* lowercase         */
 83  0x00000000,
 84  0x00000000,
 85  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
 86  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
 87};
 88
 89static inline int inword(const unsigned char c) {
 90	return ( inwordLut[c>>5] >> (c & 0x1F) ) & 1;
 91}
 92
 93/* set inwordLut contents. Invoked by ioctl(). */
 94int sel_loadlut(char __user *p)
 95{
 96	return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
 97}
 98
 99/* does screen address p correspond to character at LH/RH edge of screen? */
100static inline int atedge(const int p, int size_row)
101{
102	return (!(p % size_row)	|| !((p + 2) % size_row));
103}
104
105/* constrain v such that v <= u */
106static inline unsigned short limit(const unsigned short v, const unsigned short u)
107{
108	return (v > u) ? u : v;
109}
110
111/* set the current selection. Invoked by ioctl() or by kernel code. */
112int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
113{
114	struct vc_data *vc = vc_cons[fg_console].d;
115	int sel_mode, new_sel_start, new_sel_end, spc;
116	char *bp, *obp;
117	int i, ps, pe;
118
119	poke_blanked_console();
120
121	{ unsigned short xs, ys, xe, ye;
122
123	  if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
124		return -EFAULT;
125	  __get_user(xs, &sel->xs);
126	  __get_user(ys, &sel->ys);
127	  __get_user(xe, &sel->xe);
128	  __get_user(ye, &sel->ye);
129	  __get_user(sel_mode, &sel->sel_mode);
130	  xs--; ys--; xe--; ye--;
131	  xs = limit(xs, vc->vc_cols - 1);
132	  ys = limit(ys, vc->vc_rows - 1);
133	  xe = limit(xe, vc->vc_cols - 1);
134	  ye = limit(ye, vc->vc_rows - 1);
135	  ps = ys * vc->vc_size_row + (xs << 1);
136	  pe = ye * vc->vc_size_row + (xe << 1);
137
138	  if (sel_mode == TIOCL_SELCLEAR) {
139	      /* useful for screendump without selection highlights */
140	      clear_selection();
141	      return 0;
142	  }
143
144	  if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
145	      mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
146	      return 0;
147	  }
148        }
149
150	if (ps > pe)	/* make sel_start <= sel_end */
151	{
152		int tmp = ps;
153		ps = pe;
154		pe = tmp;
155	}
156
157	if (sel_cons != vc_cons[fg_console].d) {
158		clear_selection();
159		sel_cons = vc_cons[fg_console].d;
160	}
161
162	switch (sel_mode)
163	{
164		case TIOCL_SELCHAR:	/* character-by-character selection */
165			new_sel_start = ps;
166			new_sel_end = pe;
167			break;
168		case TIOCL_SELWORD:	/* word-by-word selection */
169			spc = isspace(sel_pos(ps));
170			for (new_sel_start = ps; ; ps -= 2)
171			{
172				if ((spc && !isspace(sel_pos(ps))) ||
173				    (!spc && !inword(sel_pos(ps))))
174					break;
175				new_sel_start = ps;
176				if (!(ps % vc->vc_size_row))
177					break;
178			}
179			spc = isspace(sel_pos(pe));
180			for (new_sel_end = pe; ; pe += 2)
181			{
182				if ((spc && !isspace(sel_pos(pe))) ||
183				    (!spc && !inword(sel_pos(pe))))
184					break;
185				new_sel_end = pe;
186				if (!((pe + 2) % vc->vc_size_row))
187					break;
188			}
189			break;
190		case TIOCL_SELLINE:	/* line-by-line selection */
191			new_sel_start = ps - ps % vc->vc_size_row;
192			new_sel_end = pe + vc->vc_size_row
193				    - pe % vc->vc_size_row - 2;
194			break;
195		case TIOCL_SELPOINTER:
196			highlight_pointer(pe);
197			return 0;
198		default:
199			return -EINVAL;
200	}
201
202	/* remove the pointer */
203	highlight_pointer(-1);
204
205	/* select to end of line if on trailing space */
206	if (new_sel_end > new_sel_start &&
207		!atedge(new_sel_end, vc->vc_size_row) &&
208		isspace(sel_pos(new_sel_end))) {
209		for (pe = new_sel_end + 2; ; pe += 2)
210			if (!isspace(sel_pos(pe)) ||
211			    atedge(pe, vc->vc_size_row))
212				break;
213		if (isspace(sel_pos(pe)))
214			new_sel_end = pe;
215	}
216	if (sel_start == -1)	/* no current selection */
217		highlight(new_sel_start, new_sel_end);
218	else if (new_sel_start == sel_start)
219	{
220		if (new_sel_end == sel_end)	/* no action required */
221			return 0;
222		else if (new_sel_end > sel_end)	/* extend to right */
223			highlight(sel_end + 2, new_sel_end);
224		else				/* contract from right */
225			highlight(new_sel_end + 2, sel_end);
226	}
227	else if (new_sel_end == sel_end)
228	{
229		if (new_sel_start < sel_start)	/* extend to left */
230			highlight(new_sel_start, sel_start - 2);
231		else				/* contract from left */
232			highlight(sel_start, new_sel_start - 2);
233	}
234	else	/* some other case; start selection from scratch */
235	{
236		clear_selection();
237		highlight(new_sel_start, new_sel_end);
238	}
239	sel_start = new_sel_start;
240	sel_end = new_sel_end;
241
242	/* Allocate a new buffer before freeing the old one ... */
243	bp = kmalloc((sel_end-sel_start)/2+1, GFP_KERNEL);
244	if (!bp) {
245		printk(KERN_WARNING "selection: kmalloc() failed\n");
246		clear_selection();
247		return -ENOMEM;
248	}
249	if (sel_buffer)
250		kfree(sel_buffer);
251	sel_buffer = bp;
252
253	obp = bp;
254	for (i = sel_start; i <= sel_end; i += 2) {
255		*bp = sel_pos(i);
256		if (!isspace(*bp++))
257			obp = bp;
258		if (! ((i + 2) % vc->vc_size_row)) {
259			/* strip trailing blanks from line and add newline,
260			   unless non-space at end of line. */
261			if (obp != bp) {
262				bp = obp;
263				*bp++ = '\r';
264			}
265			obp = bp;
266		}
267	}
268	sel_buffer_lth = bp - sel_buffer;
269	return 0;
270}
271
272/* Insert the contents of the selection buffer into the
273 * queue of the tty associated with the current console.
274 * Invoked by ioctl().
275 */
276int paste_selection(struct tty_struct *tty)
277{
278	struct vc_data *vc = (struct vc_data *)tty->driver_data;
279	int	pasted = 0, count;
280	struct  tty_ldisc *ld;
281	DECLARE_WAITQUEUE(wait, current);
282
283	acquire_console_sem();
284	poke_blanked_console();
285	release_console_sem();
286
287	ld = tty_ldisc_ref_wait(tty);
288	
289	add_wait_queue(&vc->paste_wait, &wait);
290	while (sel_buffer && sel_buffer_lth > pasted) {
291		set_current_state(TASK_INTERRUPTIBLE);
292		if (test_bit(TTY_THROTTLED, &tty->flags)) {
293			schedule();
294			continue;
295		}
296		count = sel_buffer_lth - pasted;
297		count = min(count, tty->ldisc.receive_room(tty));
298		tty->ldisc.receive_buf(tty, sel_buffer + pasted, NULL, count);
299		pasted += count;
300	}
301	remove_wait_queue(&vc->paste_wait, &wait);
302	current->state = TASK_RUNNING;
303
304	tty_ldisc_deref(ld);
305	return 0;
306}