xref: /linux/drivers/tty/vt/selection.c (revision 079c9534a96da9a85a2a2f9715851050fbfbf749)
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 
31 extern void poke_blanked_console(void);
32 
33 /* FIXME: all this needs locking */
34 /* Variables for selection control. */
35 /* Use a dynamic buffer, instead of static (Dec 1994) */
36 struct vc_data *sel_cons;		/* must not be deallocated */
37 static int use_unicode;
38 static volatile int sel_start = -1; 	/* cleared by clear_selection */
39 static int sel_end;
40 static int sel_buffer_lth;
41 static char *sel_buffer;
42 
43 /* clear_selection, highlight and highlight_pointer can be called
44    from interrupt (via scrollback/front) */
45 
46 /* set reverse video on characters s-e of console with selection. */
47 static inline void highlight(const int s, const int e)
48 {
49 	invert_screen(sel_cons, s, e-s+2, 1);
50 }
51 
52 /* use complementary color to show the pointer */
53 static inline void highlight_pointer(const int where)
54 {
55 	complement_pos(sel_cons, where);
56 }
57 
58 static u16
59 sel_pos(int n)
60 {
61 	return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
62 				use_unicode);
63 }
64 
65 /* remove the current selection highlight, if any,
66    from the console holding the selection. */
67 void
68 clear_selection(void) {
69 	highlight_pointer(-1); /* hide the pointer */
70 	if (sel_start != -1) {
71 		highlight(sel_start, sel_end);
72 		sel_start = -1;
73 	}
74 }
75 
76 /*
77  * User settable table: what characters are to be considered alphabetic?
78  * 256 bits
79  */
80 static u32 inwordLut[8]={
81   0x00000000, /* control chars     */
82   0x03FF0000, /* digits            */
83   0x87FFFFFE, /* uppercase and '_' */
84   0x07FFFFFE, /* lowercase         */
85   0x00000000,
86   0x00000000,
87   0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
88   0xFF7FFFFF  /* latin-1 accented letters, not division sign */
89 };
90 
91 static inline int inword(const u16 c) {
92 	return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
93 }
94 
95 /* set inwordLut contents. Invoked by ioctl(). */
96 int sel_loadlut(char __user *p)
97 {
98 	return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
99 }
100 
101 /* does screen address p correspond to character at LH/RH edge of screen? */
102 static inline int atedge(const int p, int size_row)
103 {
104 	return (!(p % size_row)	|| !((p + 2) % size_row));
105 }
106 
107 /* constrain v such that v <= u */
108 static inline unsigned short limit(const unsigned short v, const unsigned short u)
109 {
110 	return (v > u) ? u : v;
111 }
112 
113 /* stores the char in UTF8 and returns the number of bytes used (1-3) */
114 static int store_utf8(u16 c, char *p)
115 {
116 	if (c < 0x80) {
117 		/*  0******* */
118 		p[0] = c;
119 		return 1;
120 	} else if (c < 0x800) {
121 		/* 110***** 10****** */
122 		p[0] = 0xc0 | (c >> 6);
123 		p[1] = 0x80 | (c & 0x3f);
124 		return 2;
125     	} else {
126 		/* 1110**** 10****** 10****** */
127 		p[0] = 0xe0 | (c >> 12);
128 		p[1] = 0x80 | ((c >> 6) & 0x3f);
129 		p[2] = 0x80 | (c & 0x3f);
130 		return 3;
131     	}
132 }
133 
134 /* set the current selection. Invoked by ioctl() or by kernel code. */
135 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
136 {
137 	struct vc_data *vc = vc_cons[fg_console].d;
138 	int sel_mode, new_sel_start, new_sel_end, spc;
139 	char *bp, *obp;
140 	int i, ps, pe, multiplier;
141 	u16 c;
142 	int mode;
143 
144 	poke_blanked_console();
145 
146 	{ unsigned short xs, ys, xe, ye;
147 
148 	  if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
149 		return -EFAULT;
150 	  __get_user(xs, &sel->xs);
151 	  __get_user(ys, &sel->ys);
152 	  __get_user(xe, &sel->xe);
153 	  __get_user(ye, &sel->ye);
154 	  __get_user(sel_mode, &sel->sel_mode);
155 	  xs--; ys--; xe--; ye--;
156 	  xs = limit(xs, vc->vc_cols - 1);
157 	  ys = limit(ys, vc->vc_rows - 1);
158 	  xe = limit(xe, vc->vc_cols - 1);
159 	  ye = limit(ye, vc->vc_rows - 1);
160 	  ps = ys * vc->vc_size_row + (xs << 1);
161 	  pe = ye * vc->vc_size_row + (xe << 1);
162 
163 	  if (sel_mode == TIOCL_SELCLEAR) {
164 	      /* useful for screendump without selection highlights */
165 	      clear_selection();
166 	      return 0;
167 	  }
168 
169 	  if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
170 	      mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
171 	      return 0;
172 	  }
173         }
174 
175 	if (ps > pe)	/* make sel_start <= sel_end */
176 	{
177 		int tmp = ps;
178 		ps = pe;
179 		pe = tmp;
180 	}
181 
182 	if (sel_cons != vc_cons[fg_console].d) {
183 		clear_selection();
184 		sel_cons = vc_cons[fg_console].d;
185 	}
186 	mode = vt_do_kdgkbmode(fg_console);
187 	if (mode == K_UNICODE)
188 		use_unicode = 1;
189 	else
190 		use_unicode = 0;
191 
192 	switch (sel_mode)
193 	{
194 		case TIOCL_SELCHAR:	/* character-by-character selection */
195 			new_sel_start = ps;
196 			new_sel_end = pe;
197 			break;
198 		case TIOCL_SELWORD:	/* word-by-word selection */
199 			spc = isspace(sel_pos(ps));
200 			for (new_sel_start = ps; ; ps -= 2)
201 			{
202 				if ((spc && !isspace(sel_pos(ps))) ||
203 				    (!spc && !inword(sel_pos(ps))))
204 					break;
205 				new_sel_start = ps;
206 				if (!(ps % vc->vc_size_row))
207 					break;
208 			}
209 			spc = isspace(sel_pos(pe));
210 			for (new_sel_end = pe; ; pe += 2)
211 			{
212 				if ((spc && !isspace(sel_pos(pe))) ||
213 				    (!spc && !inword(sel_pos(pe))))
214 					break;
215 				new_sel_end = pe;
216 				if (!((pe + 2) % vc->vc_size_row))
217 					break;
218 			}
219 			break;
220 		case TIOCL_SELLINE:	/* line-by-line selection */
221 			new_sel_start = ps - ps % vc->vc_size_row;
222 			new_sel_end = pe + vc->vc_size_row
223 				    - pe % vc->vc_size_row - 2;
224 			break;
225 		case TIOCL_SELPOINTER:
226 			highlight_pointer(pe);
227 			return 0;
228 		default:
229 			return -EINVAL;
230 	}
231 
232 	/* remove the pointer */
233 	highlight_pointer(-1);
234 
235 	/* select to end of line if on trailing space */
236 	if (new_sel_end > new_sel_start &&
237 		!atedge(new_sel_end, vc->vc_size_row) &&
238 		isspace(sel_pos(new_sel_end))) {
239 		for (pe = new_sel_end + 2; ; pe += 2)
240 			if (!isspace(sel_pos(pe)) ||
241 			    atedge(pe, vc->vc_size_row))
242 				break;
243 		if (isspace(sel_pos(pe)))
244 			new_sel_end = pe;
245 	}
246 	if (sel_start == -1)	/* no current selection */
247 		highlight(new_sel_start, new_sel_end);
248 	else if (new_sel_start == sel_start)
249 	{
250 		if (new_sel_end == sel_end)	/* no action required */
251 			return 0;
252 		else if (new_sel_end > sel_end)	/* extend to right */
253 			highlight(sel_end + 2, new_sel_end);
254 		else				/* contract from right */
255 			highlight(new_sel_end + 2, sel_end);
256 	}
257 	else if (new_sel_end == sel_end)
258 	{
259 		if (new_sel_start < sel_start)	/* extend to left */
260 			highlight(new_sel_start, sel_start - 2);
261 		else				/* contract from left */
262 			highlight(sel_start, new_sel_start - 2);
263 	}
264 	else	/* some other case; start selection from scratch */
265 	{
266 		clear_selection();
267 		highlight(new_sel_start, new_sel_end);
268 	}
269 	sel_start = new_sel_start;
270 	sel_end = new_sel_end;
271 
272 	/* Allocate a new buffer before freeing the old one ... */
273 	multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
274 	bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
275 	if (!bp) {
276 		printk(KERN_WARNING "selection: kmalloc() failed\n");
277 		clear_selection();
278 		return -ENOMEM;
279 	}
280 	kfree(sel_buffer);
281 	sel_buffer = bp;
282 
283 	obp = bp;
284 	for (i = sel_start; i <= sel_end; i += 2) {
285 		c = sel_pos(i);
286 		if (use_unicode)
287 			bp += store_utf8(c, bp);
288 		else
289 			*bp++ = c;
290 		if (!isspace(c))
291 			obp = bp;
292 		if (! ((i + 2) % vc->vc_size_row)) {
293 			/* strip trailing blanks from line and add newline,
294 			   unless non-space at end of line. */
295 			if (obp != bp) {
296 				bp = obp;
297 				*bp++ = '\r';
298 			}
299 			obp = bp;
300 		}
301 	}
302 	sel_buffer_lth = bp - sel_buffer;
303 	return 0;
304 }
305 
306 /* Insert the contents of the selection buffer into the
307  * queue of the tty associated with the current console.
308  * Invoked by ioctl().
309  *
310  * Locking: always called with BTM from vt_ioctl
311  */
312 int paste_selection(struct tty_struct *tty)
313 {
314 	struct vc_data *vc = tty->driver_data;
315 	int	pasted = 0;
316 	unsigned int count;
317 	struct  tty_ldisc *ld;
318 	DECLARE_WAITQUEUE(wait, current);
319 
320 
321 	console_lock();
322 	poke_blanked_console();
323 	console_unlock();
324 
325 	ld = tty_ldisc_ref(tty);
326 	if (!ld) {
327 		tty_unlock();
328 		ld = tty_ldisc_ref_wait(tty);
329 		tty_lock();
330 	}
331 
332 	add_wait_queue(&vc->paste_wait, &wait);
333 	while (sel_buffer && sel_buffer_lth > pasted) {
334 		set_current_state(TASK_INTERRUPTIBLE);
335 		if (test_bit(TTY_THROTTLED, &tty->flags)) {
336 			schedule();
337 			continue;
338 		}
339 		count = sel_buffer_lth - pasted;
340 		count = min(count, tty->receive_room);
341 		tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
342 								NULL, count);
343 		pasted += count;
344 	}
345 	remove_wait_queue(&vc->paste_wait, &wait);
346 	__set_current_state(TASK_RUNNING);
347 
348 	tty_ldisc_deref(ld);
349 	return 0;
350 }
351