drivers/tty/vt/selection.c

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