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 /* FIXME: all this needs locking */
  34 /* Variables for selection control. */
  35 /* Use a dynamic buffer, instead of static (Dec 1994) */
  36 struct vc_data *sel_cons;               /* must not be deallocated */
  37 static int use_unicode;
  38 static volatile int sel_start = -1;     /* cleared by clear_selection */
  39 static int sel_end;
  40 static int sel_buffer_lth;
  41 static char *sel_buffer;
  42
  43 /* clear_selection, highlight and highlight_pointer can be called
  44    from interrupt (via scrollback/front) */
  45
  46 /* set reverse video on characters s-e of console with selection. */
  47 static inline void 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 static inline void highlight_pointer(const int where)
  54 {
  55         complement_pos(sel_cons, where);
  56 }
  57
  58 static u16
  59 sel_pos(int n)
  60 {
  61         return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
  62                                 use_unicode);
  63 }
  64
  65 /**
  66  *      clear_selection         -       remove current selection
  67  *
  68  *      Remove the current selection highlight, if any from the console
  69  *      holding the selection. The caller must hold the console lock.
  70  */
  71 void clear_selection(void)
  72 {
  73         highlight_pointer(-1); /* hide the pointer */
  74         if (sel_start != -1) {
  75                 highlight(sel_start, sel_end);
  76                 sel_start = -1;
  77         }
  78 }
  79
  80 /*
  81  * User settable table: what characters are to be considered alphabetic?
  82  * 256 bits. Locked by the console lock.
  83  */
  84 static u32 inwordLut[8]={
  85   0x00000000, /* control chars     */
  86   0x03FF0000, /* digits            */
  87   0x87FFFFFE, /* uppercase and '_' */
  88   0x07FFFFFE, /* lowercase         */
  89   0x00000000,
  90   0x00000000,
  91   0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
  92   0xFF7FFFFF  /* latin-1 accented letters, not division sign */
  93 };
  94
  95 static inline int inword(const u16 c) {
  96         return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
  97 }
  98
  99 /**
 100  *      set loadlut             -       load the LUT table
 101  *      @p: user table
 102  *
 103  *      Load the LUT table from user space. The caller must hold the console
 104  *      lock. Make a temporary copy so a partial update doesn't make a mess.
 105  */
 106 int sel_loadlut(char __user *p)
 107 {
 108         u32 tmplut[8];
 109         if (copy_from_user(tmplut, (u32 __user *)(p+4), 32))
 110                 return -EFAULT;
 111         memcpy(inwordLut, tmplut, 32);
 112         return 0;
 113 }
 114
 115 /* does screen address p correspond to character at LH/RH edge of screen? */
 116 static inline int atedge(const int p, int size_row)
 117 {
 118         return (!(p % size_row) || !((p + 2) % size_row));
 119 }
 120
 121 /* constrain v such that v <= u */
 122 static inline unsigned short limit(const unsigned short v, const unsigned short u)
 123 {
 124         return (v > u) ? u : v;
 125 }
 126
 127 /* stores the char in UTF8 and returns the number of bytes used (1-3) */
 128 static int store_utf8(u16 c, char *p)
 129 {
 130         if (c < 0x80) {
 131                 /*  0******* */
 132                 p[0] = c;
 133                 return 1;
 134         } else if (c < 0x800) {
 135                 /* 110***** 10****** */
 136                 p[0] = 0xc0 | (c >> 6);
 137                 p[1] = 0x80 | (c & 0x3f);
 138                 return 2;
 139         } else {
 140                 /* 1110**** 10****** 10****** */
 141                 p[0] = 0xe0 | (c >> 12);
 142                 p[1] = 0x80 | ((c >> 6) & 0x3f);
 143                 p[2] = 0x80 | (c & 0x3f);
 144                 return 3;
 145         }
 146 }
 147
 148 /**
 149  *      set_selection           -       set the current selection.
 150  *      @sel: user selection info
 151  *      @tty: the console tty
 152  *
 153  *      Invoked by the ioctl handle for the vt layer.
 154  *
 155  *      The entire selection process is managed under the console_lock. It's
 156  *       a lot under the lock but its hardly a performance path
 157  */
 158 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 159 {
 160         struct vc_data *vc = vc_cons[fg_console].d;
 161         int sel_mode, new_sel_start, new_sel_end, spc;
 162         char *bp, *obp;
 163         int i, ps, pe, multiplier;
 164         u16 c;
 165         int mode;
 166
 167         poke_blanked_console();
 168
 169         { unsigned short xs, ys, xe, ye;
 170
 171           if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
 172                 return -EFAULT;
 173           __get_user(xs, &sel->xs);
 174           __get_user(ys, &sel->ys);
 175           __get_user(xe, &sel->xe);
 176           __get_user(ye, &sel->ye);
 177           __get_user(sel_mode, &sel->sel_mode);
 178           xs--; ys--; xe--; ye--;
 179           xs = limit(xs, vc->vc_cols - 1);
 180           ys = limit(ys, vc->vc_rows - 1);
 181           xe = limit(xe, vc->vc_cols - 1);
 182           ye = limit(ye, vc->vc_rows - 1);
 183           ps = ys * vc->vc_size_row + (xs << 1);
 184           pe = ye * vc->vc_size_row + (xe << 1);
 185
 186           if (sel_mode == TIOCL_SELCLEAR) {
 187               /* useful for screendump without selection highlights */
 188               clear_selection();
 189               return 0;
 190           }
 191
 192           if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
 193               mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
 194               return 0;
 195           }
 196         }
 197
 198         if (ps > pe)    /* make sel_start <= sel_end */
 199         {
 200                 int tmp = ps;
 201                 ps = pe;
 202                 pe = tmp;
 203         }
 204
 205         if (sel_cons != vc_cons[fg_console].d) {
 206                 clear_selection();
 207                 sel_cons = vc_cons[fg_console].d;
 208         }
 209         mode = vt_do_kdgkbmode(fg_console);
 210         if (mode == K_UNICODE)
 211                 use_unicode = 1;
 212         else
 213                 use_unicode = 0;
 214
 215         switch (sel_mode)
 216         {
 217                 case TIOCL_SELCHAR:     /* character-by-character selection */
 218                         new_sel_start = ps;
 219                         new_sel_end = pe;
 220                         break;
 221                 case TIOCL_SELWORD:     /* word-by-word selection */
 222                         spc = isspace(sel_pos(ps));
 223                         for (new_sel_start = ps; ; ps -= 2)
 224                         {
 225                                 if ((spc && !isspace(sel_pos(ps))) ||
 226                                     (!spc && !inword(sel_pos(ps))))
 227                                         break;
 228                                 new_sel_start = ps;
 229                                 if (!(ps % vc->vc_size_row))
 230                                         break;
 231                         }
 232                         spc = isspace(sel_pos(pe));
 233                         for (new_sel_end = pe; ; pe += 2)
 234                         {
 235                                 if ((spc && !isspace(sel_pos(pe))) ||
 236                                     (!spc && !inword(sel_pos(pe))))
 237                                         break;
 238                                 new_sel_end = pe;
 239                                 if (!((pe + 2) % vc->vc_size_row))
 240                                         break;
 241                         }
 242                         break;
 243                 case TIOCL_SELLINE:     /* line-by-line selection */
 244                         new_sel_start = ps - ps % vc->vc_size_row;
 245                         new_sel_end = pe + vc->vc_size_row
 246                                     - pe % vc->vc_size_row - 2;
 247                         break;
 248                 case TIOCL_SELPOINTER:
 249                         highlight_pointer(pe);
 250                         return 0;
 251                 default:
 252                         return -EINVAL;
 253         }
 254
 255         /* remove the pointer */
 256         highlight_pointer(-1);
 257
 258         /* select to end of line if on trailing space */
 259         if (new_sel_end > new_sel_start &&
 260                 !atedge(new_sel_end, vc->vc_size_row) &&
 261                 isspace(sel_pos(new_sel_end))) {
 262                 for (pe = new_sel_end + 2; ; pe += 2)
 263                         if (!isspace(sel_pos(pe)) ||
 264                             atedge(pe, vc->vc_size_row))
 265                                 break;
 266                 if (isspace(sel_pos(pe)))
 267                         new_sel_end = pe;
 268         }
 269         if (sel_start == -1)    /* no current selection */
 270                 highlight(new_sel_start, new_sel_end);
 271         else if (new_sel_start == sel_start)
 272         {
 273                 if (new_sel_end == sel_end)     /* no action required */
 274                         return 0;
 275                 else if (new_sel_end > sel_end) /* extend to right */
 276                         highlight(sel_end + 2, new_sel_end);
 277                 else                            /* contract from right */
 278                         highlight(new_sel_end + 2, sel_end);
 279         }
 280         else if (new_sel_end == sel_end)
 281         {
 282                 if (new_sel_start < sel_start)  /* extend to left */
 283                         highlight(new_sel_start, sel_start - 2);
 284                 else                            /* contract from left */
 285                         highlight(sel_start, new_sel_start - 2);
 286         }
 287         else    /* some other case; start selection from scratch */
 288         {
 289                 clear_selection();
 290                 highlight(new_sel_start, new_sel_end);
 291         }
 292         sel_start = new_sel_start;
 293         sel_end = new_sel_end;
 294
 295         /* Allocate a new buffer before freeing the old one ... */
 296         multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
 297         bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
 298         if (!bp) {
 299                 printk(KERN_WARNING "selection: kmalloc() failed\n");
 300                 clear_selection();
 301                 return -ENOMEM;
 302         }
 303         kfree(sel_buffer);
 304         sel_buffer = bp;
 305
 306         obp = bp;
 307         for (i = sel_start; i <= sel_end; i += 2) {
 308                 c = sel_pos(i);
 309                 if (use_unicode)
 310                         bp += store_utf8(c, bp);
 311                 else
 312                         *bp++ = c;
 313                 if (!isspace(c))
 314                         obp = bp;
 315                 if (! ((i + 2) % vc->vc_size_row)) {
 316                         /* strip trailing blanks from line and add newline,
 317                            unless non-space at end of line. */
 318                         if (obp != bp) {
 319                                 bp = obp;
 320                                 *bp++ = '\r';
 321                         }
 322                         obp = bp;
 323                 }
 324         }
 325         sel_buffer_lth = bp - sel_buffer;
 326         return 0;
 327 }
 328
 329 /* Insert the contents of the selection buffer into the
 330  * queue of the tty associated with the current console.
 331  * Invoked by ioctl().
 332  *
 333  * Locking: called without locks. Calls the ldisc wrongly with
 334  * unsafe methods,
 335  */
 336 int paste_selection(struct tty_struct *tty)
 337 {
 338         struct vc_data *vc = tty->driver_data;
 339         int     pasted = 0;
 340         unsigned int count;
 341         struct  tty_ldisc *ld;
 342         DECLARE_WAITQUEUE(wait, current);
 343
 344
 345         console_lock();
 346         poke_blanked_console();
 347         console_unlock();
 348
 349         /* FIXME: wtf is this supposed to achieve ? */
 350         ld = tty_ldisc_ref(tty);
 351         if (!ld)
 352                 ld = tty_ldisc_ref_wait(tty);
 353
 354         /* FIXME: this is completely unsafe */
 355         add_wait_queue(&vc->paste_wait, &wait);
 356         while (sel_buffer && sel_buffer_lth > pasted) {
 357                 set_current_state(TASK_INTERRUPTIBLE);
 358                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 359                         schedule();
 360                         continue;
 361                 }
 362                 count = sel_buffer_lth - pasted;
 363                 count = min(count, tty->receive_room);
 364                 tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
 365                                                                 NULL, count);
 366                 pasted += count;
 367         }
 368         remove_wait_queue(&vc->paste_wait, &wait);
 369         __set_current_state(TASK_RUNNING);
 370
 371         tty_ldisc_deref(ld);
 372         return 0;
 373 }