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