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/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
  32 extern void poke_blanked_console(void);
  33
  34 /* Variables for selection control. */
  35 /* Use a dynamic buffer, instead of static (Dec 1994) */
  36 struct vc_data *sel_cons;               /* must not be disallocated */
  37 static volatile int sel_start = -1;     /* cleared by clear_selection */
  38 static int sel_end;
  39 static int sel_buffer_lth;
  40 static 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. */
  46 static 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 */
  52 static inline void highlight_pointer(const int where)
  53 {
  54         complement_pos(sel_cons, where);
  55 }
  56
  57 static unsigned char
  58 sel_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. */
  65 void
  66 clear_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  */
  78 static 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
  89 static inline int inword(const unsigned char c) {
  90         return ( inwordLut[c>>5] >> (c & 0x1F) ) & 1;
  91 }
  92
  93 /* set inwordLut contents. Invoked by ioctl(). */
  94 int 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? */
 100 static 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 */
 106 static 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. */
 112 int 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  */
 276 int 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 }