Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / drivers / char / selection.c
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/kbd_kern.h>
24 #include <linux/vt_kern.h>
25 #include <linux/consolemap.h>
26 #include <linux/selection.h>
27 #include <linux/tiocl.h>
28 #include <linux/console.h>
29
30 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
31 #define isspace(c)      ((c) == ' ')
32
33 extern void poke_blanked_console(void);
34
35 /* Variables for selection control. */
36 /* Use a dynamic buffer, instead of static (Dec 1994) */
37 struct vc_data *sel_cons;               /* must not be deallocated */
38 static int use_unicode;
39 static volatile int sel_start = -1;     /* cleared by clear_selection */
40 static int sel_end;
41 static int sel_buffer_lth;
42 static 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. */
48 static 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 */
54 static inline void highlight_pointer(const int where)
55 {
56         complement_pos(sel_cons, where);
57 }
58
59 static u16
60 sel_pos(int n)
61 {
62         return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
63                                 use_unicode);
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 u16 c) {
93         return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
94 }
95
96 /* set inwordLut contents. Invoked by ioctl(). */
97 int sel_loadlut(char __user *p)
98 {
99         return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
100 }
101
102 /* does screen address p correspond to character at LH/RH edge of screen? */
103 static inline int atedge(const int p, int size_row)
104 {
105         return (!(p % size_row) || !((p + 2) % size_row));
106 }
107
108 /* constrain v such that v <= u */
109 static inline unsigned short limit(const unsigned short v, const unsigned short u)
110 {
111         return (v > u) ? u : v;
112 }
113
114 /* stores the char in UTF8 and returns the number of bytes used (1-3) */
115 static int store_utf8(u16 c, char *p)
116 {
117         if (c < 0x80) {
118                 /*  0******* */
119                 p[0] = c;
120                 return 1;
121         } else if (c < 0x800) {
122                 /* 110***** 10****** */
123                 p[0] = 0xc0 | (c >> 6);
124                 p[1] = 0x80 | (c & 0x3f);
125                 return 2;
126         } else {
127                 /* 1110**** 10****** 10****** */
128                 p[0] = 0xe0 | (c >> 12);
129                 p[1] = 0x80 | ((c >> 6) & 0x3f);
130                 p[2] = 0x80 | (c & 0x3f);
131                 return 3;
132         }
133 }
134
135 /* set the current selection. Invoked by ioctl() or by kernel code. */
136 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
137 {
138         struct vc_data *vc = vc_cons[fg_console].d;
139         int sel_mode, new_sel_start, new_sel_end, spc;
140         char *bp, *obp;
141         int i, ps, pe, multiplier;
142         u16 c;
143         struct kbd_struct *kbd = kbd_table + fg_console;
144
145         poke_blanked_console();
146
147         { unsigned short xs, ys, xe, ye;
148
149           if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
150                 return -EFAULT;
151           __get_user(xs, &sel->xs);
152           __get_user(ys, &sel->ys);
153           __get_user(xe, &sel->xe);
154           __get_user(ye, &sel->ye);
155           __get_user(sel_mode, &sel->sel_mode);
156           xs--; ys--; xe--; ye--;
157           xs = limit(xs, vc->vc_cols - 1);
158           ys = limit(ys, vc->vc_rows - 1);
159           xe = limit(xe, vc->vc_cols - 1);
160           ye = limit(ye, vc->vc_rows - 1);
161           ps = ys * vc->vc_size_row + (xs << 1);
162           pe = ye * vc->vc_size_row + (xe << 1);
163
164           if (sel_mode == TIOCL_SELCLEAR) {
165               /* useful for screendump without selection highlights */
166               clear_selection();
167               return 0;
168           }
169
170           if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
171               mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
172               return 0;
173           }
174         }
175
176         if (ps > pe)    /* make sel_start <= sel_end */
177         {
178                 int tmp = ps;
179                 ps = pe;
180                 pe = tmp;
181         }
182
183         if (sel_cons != vc_cons[fg_console].d) {
184                 clear_selection();
185                 sel_cons = vc_cons[fg_console].d;
186         }
187         use_unicode = kbd && kbd->kbdmode == VC_UNICODE;
188
189         switch (sel_mode)
190         {
191                 case TIOCL_SELCHAR:     /* character-by-character selection */
192                         new_sel_start = ps;
193                         new_sel_end = pe;
194                         break;
195                 case TIOCL_SELWORD:     /* word-by-word selection */
196                         spc = isspace(sel_pos(ps));
197                         for (new_sel_start = ps; ; ps -= 2)
198                         {
199                                 if ((spc && !isspace(sel_pos(ps))) ||
200                                     (!spc && !inword(sel_pos(ps))))
201                                         break;
202                                 new_sel_start = ps;
203                                 if (!(ps % vc->vc_size_row))
204                                         break;
205                         }
206                         spc = isspace(sel_pos(pe));
207                         for (new_sel_end = pe; ; pe += 2)
208                         {
209                                 if ((spc && !isspace(sel_pos(pe))) ||
210                                     (!spc && !inword(sel_pos(pe))))
211                                         break;
212                                 new_sel_end = pe;
213                                 if (!((pe + 2) % vc->vc_size_row))
214                                         break;
215                         }
216                         break;
217                 case TIOCL_SELLINE:     /* line-by-line selection */
218                         new_sel_start = ps - ps % vc->vc_size_row;
219                         new_sel_end = pe + vc->vc_size_row
220                                     - pe % vc->vc_size_row - 2;
221                         break;
222                 case TIOCL_SELPOINTER:
223                         highlight_pointer(pe);
224                         return 0;
225                 default:
226                         return -EINVAL;
227         }
228
229         /* remove the pointer */
230         highlight_pointer(-1);
231
232         /* select to end of line if on trailing space */
233         if (new_sel_end > new_sel_start &&
234                 !atedge(new_sel_end, vc->vc_size_row) &&
235                 isspace(sel_pos(new_sel_end))) {
236                 for (pe = new_sel_end + 2; ; pe += 2)
237                         if (!isspace(sel_pos(pe)) ||
238                             atedge(pe, vc->vc_size_row))
239                                 break;
240                 if (isspace(sel_pos(pe)))
241                         new_sel_end = pe;
242         }
243         if (sel_start == -1)    /* no current selection */
244                 highlight(new_sel_start, new_sel_end);
245         else if (new_sel_start == sel_start)
246         {
247                 if (new_sel_end == sel_end)     /* no action required */
248                         return 0;
249                 else if (new_sel_end > sel_end) /* extend to right */
250                         highlight(sel_end + 2, new_sel_end);
251                 else                            /* contract from right */
252                         highlight(new_sel_end + 2, sel_end);
253         }
254         else if (new_sel_end == sel_end)
255         {
256                 if (new_sel_start < sel_start)  /* extend to left */
257                         highlight(new_sel_start, sel_start - 2);
258                 else                            /* contract from left */
259                         highlight(sel_start, new_sel_start - 2);
260         }
261         else    /* some other case; start selection from scratch */
262         {
263                 clear_selection();
264                 highlight(new_sel_start, new_sel_end);
265         }
266         sel_start = new_sel_start;
267         sel_end = new_sel_end;
268
269         /* Allocate a new buffer before freeing the old one ... */
270         multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
271         bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
272         if (!bp) {
273                 printk(KERN_WARNING "selection: kmalloc() failed\n");
274                 clear_selection();
275                 return -ENOMEM;
276         }
277         kfree(sel_buffer);
278         sel_buffer = bp;
279
280         obp = bp;
281         for (i = sel_start; i <= sel_end; i += 2) {
282                 c = sel_pos(i);
283                 if (use_unicode)
284                         bp += store_utf8(c, bp);
285                 else
286                         *bp++ = c;
287                 if (!isspace(c))
288                         obp = bp;
289                 if (! ((i + 2) % vc->vc_size_row)) {
290                         /* strip trailing blanks from line and add newline,
291                            unless non-space at end of line. */
292                         if (obp != bp) {
293                                 bp = obp;
294                                 *bp++ = '\r';
295                         }
296                         obp = bp;
297                 }
298         }
299         sel_buffer_lth = bp - sel_buffer;
300         return 0;
301 }
302
303 /* Insert the contents of the selection buffer into the
304  * queue of the tty associated with the current console.
305  * Invoked by ioctl().
306  */
307 int paste_selection(struct tty_struct *tty)
308 {
309         struct vc_data *vc = tty->driver_data;
310         int     pasted = 0;
311         unsigned int count;
312         struct  tty_ldisc *ld;
313         DECLARE_WAITQUEUE(wait, current);
314
315         acquire_console_sem();
316         poke_blanked_console();
317         release_console_sem();
318
319         ld = tty_ldisc_ref_wait(tty);
320         
321         add_wait_queue(&vc->paste_wait, &wait);
322         while (sel_buffer && sel_buffer_lth > pasted) {
323                 set_current_state(TASK_INTERRUPTIBLE);
324                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
325                         schedule();
326                         continue;
327                 }
328                 count = sel_buffer_lth - pasted;
329                 count = min(count, tty->receive_room);
330                 tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
331                                                                 NULL, count);
332                 pasted += count;
333         }
334         remove_wait_queue(&vc->paste_wait, &wait);
335         __set_current_state(TASK_RUNNING);
336
337         tty_ldisc_deref(ld);
338         return 0;
339 }