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