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 inline static void
  47 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 inline static void
  54 highlight_pointer(const int where)
  55 {
  56         complement_pos(sel_cons, where);
  57 }
  58
  59 static unsigned char
  60 sel_pos(int n)
  61 {
  62         return inverse_translate(sel_cons, screen_glyph(sel_cons, n));
  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 unsigned char c) {
  92         return ( 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 /* set the current selection. Invoked by ioctl() or by kernel code. */
 114 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 115 {
 116         struct vc_data *vc = vc_cons[fg_console].d;
 117         int sel_mode, new_sel_start, new_sel_end, spc;
 118         char *bp, *obp;
 119         int i, ps, pe;
 120
 121         poke_blanked_console();
 122
 123         { unsigned short xs, ys, xe, ye;
 124
 125           if (verify_area(VERIFY_READ, sel, sizeof(*sel)))
 126                 return -EFAULT;
 127           __get_user(xs, &sel->xs);
 128           __get_user(ys, &sel->ys);
 129           __get_user(xe, &sel->xe);
 130           __get_user(ye, &sel->ye);
 131           __get_user(sel_mode, &sel->sel_mode);
 132           xs--; ys--; xe--; ye--;
 133           xs = limit(xs, vc->vc_cols - 1);
 134           ys = limit(ys, vc->vc_rows - 1);
 135           xe = limit(xe, vc->vc_cols - 1);
 136           ye = limit(ye, vc->vc_rows - 1);
 137           ps = ys * vc->vc_size_row + (xs << 1);
 138           pe = ye * vc->vc_size_row + (xe << 1);
 139
 140           if (sel_mode == TIOCL_SELCLEAR) {
 141               /* useful for screendump without selection highlights */
 142               clear_selection();
 143               return 0;
 144           }
 145
 146           if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
 147               mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
 148               return 0;
 149           }
 150         }
 151
 152         if (ps > pe)    /* make sel_start <= sel_end */
 153         {
 154                 int tmp = ps;
 155                 ps = pe;
 156                 pe = tmp;
 157         }
 158
 159         if (sel_cons != vc_cons[fg_console].d) {
 160                 clear_selection();
 161                 sel_cons = vc_cons[fg_console].d;
 162         }
 163
 164         switch (sel_mode)
 165         {
 166                 case TIOCL_SELCHAR:     /* character-by-character selection */
 167                         new_sel_start = ps;
 168                         new_sel_end = pe;
 169                         break;
 170                 case TIOCL_SELWORD:     /* word-by-word selection */
 171                         spc = isspace(sel_pos(ps));
 172                         for (new_sel_start = ps; ; ps -= 2)
 173                         {
 174                                 if ((spc && !isspace(sel_pos(ps))) ||
 175                                     (!spc && !inword(sel_pos(ps))))
 176                                         break;
 177                                 new_sel_start = ps;
 178                                 if (!(ps % vc->vc_size_row))
 179                                         break;
 180                         }
 181                         spc = isspace(sel_pos(pe));
 182                         for (new_sel_end = pe; ; pe += 2)
 183                         {
 184                                 if ((spc && !isspace(sel_pos(pe))) ||
 185                                     (!spc && !inword(sel_pos(pe))))
 186                                         break;
 187                                 new_sel_end = pe;
 188                                 if (!((pe + 2) % vc->vc_size_row))
 189                                         break;
 190                         }
 191                         break;
 192                 case TIOCL_SELLINE:     /* line-by-line selection */
 193                         new_sel_start = ps - ps % vc->vc_size_row;
 194                         new_sel_end = pe + vc->vc_size_row
 195                                     - pe % vc->vc_size_row - 2;
 196                         break;
 197                 case TIOCL_SELPOINTER:
 198                         highlight_pointer(pe);
 199                         return 0;
 200                 default:
 201                         return -EINVAL;
 202         }
 203
 204         /* remove the pointer */
 205         highlight_pointer(-1);
 206
 207         /* select to end of line if on trailing space */
 208         if (new_sel_end > new_sel_start &&
 209                 !atedge(new_sel_end, vc->vc_size_row) &&
 210                 isspace(sel_pos(new_sel_end))) {
 211                 for (pe = new_sel_end + 2; ; pe += 2)
 212                         if (!isspace(sel_pos(pe)) ||
 213                             atedge(pe, vc->vc_size_row))
 214                                 break;
 215                 if (isspace(sel_pos(pe)))
 216                         new_sel_end = pe;
 217         }
 218         if (sel_start == -1)    /* no current selection */
 219                 highlight(new_sel_start, new_sel_end);
 220         else if (new_sel_start == sel_start)
 221         {
 222                 if (new_sel_end == sel_end)     /* no action required */
 223                         return 0;
 224                 else if (new_sel_end > sel_end) /* extend to right */
 225                         highlight(sel_end + 2, new_sel_end);
 226                 else                            /* contract from right */
 227                         highlight(new_sel_end + 2, sel_end);
 228         }
 229         else if (new_sel_end == sel_end)
 230         {
 231                 if (new_sel_start < sel_start)  /* extend to left */
 232                         highlight(new_sel_start, sel_start - 2);
 233                 else                            /* contract from left */
 234                         highlight(sel_start, new_sel_start - 2);
 235         }
 236         else    /* some other case; start selection from scratch */
 237         {
 238                 clear_selection();
 239                 highlight(new_sel_start, new_sel_end);
 240         }
 241         sel_start = new_sel_start;
 242         sel_end = new_sel_end;
 243
 244         /* Allocate a new buffer before freeing the old one ... */
 245         bp = kmalloc((sel_end-sel_start)/2+1, GFP_KERNEL);
 246         if (!bp) {
 247                 printk(KERN_WARNING "selection: kmalloc() failed\n");
 248                 clear_selection();
 249                 return -ENOMEM;
 250         }
 251         if (sel_buffer)
 252                 kfree(sel_buffer);
 253         sel_buffer = bp;
 254
 255         obp = bp;
 256         for (i = sel_start; i <= sel_end; i += 2) {
 257                 *bp = sel_pos(i);
 258                 if (!isspace(*bp++))
 259                         obp = bp;
 260                 if (! ((i + 2) % vc->vc_size_row)) {
 261                         /* strip trailing blanks from line and add newline,
 262                            unless non-space at end of line. */
 263                         if (obp != bp) {
 264                                 bp = obp;
 265                                 *bp++ = '\r';
 266                         }
 267                         obp = bp;
 268                 }
 269         }
 270         sel_buffer_lth = bp - sel_buffer;
 271         return 0;
 272 }
 273
 274 /* Insert the contents of the selection buffer into the
 275  * queue of the tty associated with the current console.
 276  * Invoked by ioctl().
 277  */
 278 int paste_selection(struct tty_struct *tty)
 279 {
 280         struct vt_struct *vt = (struct vt_struct *) tty->driver_data;
 281         int     pasted = 0, count;
 282         struct  tty_ldisc *ld;
 283         DECLARE_WAITQUEUE(wait, current);
 284
 285         acquire_console_sem();
 286         poke_blanked_console();
 287         release_console_sem();
 288
 289         ld = tty_ldisc_ref_wait(tty);
 290
 291         add_wait_queue(&vt->paste_wait, &wait);
 292         while (sel_buffer && sel_buffer_lth > pasted) {
 293                 set_current_state(TASK_INTERRUPTIBLE);
 294                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 295                         schedule();
 296                         continue;
 297                 }
 298                 count = sel_buffer_lth - pasted;
 299                 count = min(count, tty->ldisc.receive_room(tty));
 300                 tty->ldisc.receive_buf(tty, sel_buffer + pasted, NULL, count);
 301                 pasted += count;
 302         }
 303         remove_wait_queue(&vt->paste_wait, &wait);
 304         current->state = TASK_RUNNING;
 305
 306         tty_ldisc_deref(ld);
 307         return 0;
 308 }