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  * 128 bits. Locked by the console lock.
  84  */
  85 static u32 inwordLut[]={
  86   0x00000000, /* control chars     */
  87   0x03FFE000, /* digits and "-./"  */
  88   0x87FFFFFE, /* uppercase and '_' */
  89   0x07FFFFFE, /* lowercase         */
  90 };
  91
  92 static inline int inword(const u16 c) {
  93         return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
  94 }
  95
  96 /**
  97  *      set loadlut             -       load the LUT table
  98  *      @p: user table
  99  *
 100  *      Load the LUT table from user space. The caller must hold the console
 101  *      lock. Make a temporary copy so a partial update doesn't make a mess.
 102  */
 103 int sel_loadlut(char __user *p)
 104 {
 105         u32 tmplut[ARRAY_SIZE(inwordLut)];
 106         if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
 107                 return -EFAULT;
 108         memcpy(inwordLut, tmplut, sizeof(inwordLut));
 109         return 0;
 110 }
 111
 112 /* does screen address p correspond to character at LH/RH edge of screen? */
 113 static inline int atedge(const int p, int size_row)
 114 {
 115         return (!(p % size_row) || !((p + 2) % size_row));
 116 }
 117
 118 /* constrain v such that v <= u */
 119 static inline unsigned short limit(const unsigned short v, const unsigned short u)
 120 {
 121         return (v > u) ? u : v;
 122 }
 123
 124 /* stores the char in UTF8 and returns the number of bytes used (1-3) */
 125 static int store_utf8(u16 c, char *p)
 126 {
 127         if (c < 0x80) {
 128                 /*  0******* */
 129                 p[0] = c;
 130                 return 1;
 131         } else if (c < 0x800) {
 132                 /* 110***** 10****** */
 133                 p[0] = 0xc0 | (c >> 6);
 134                 p[1] = 0x80 | (c & 0x3f);
 135                 return 2;
 136         } else {
 137                 /* 1110**** 10****** 10****** */
 138                 p[0] = 0xe0 | (c >> 12);
 139                 p[1] = 0x80 | ((c >> 6) & 0x3f);
 140                 p[2] = 0x80 | (c & 0x3f);
 141                 return 3;
 142         }
 143 }
 144
 145 /**
 146  *      set_selection           -       set the current selection.
 147  *      @sel: user selection info
 148  *      @tty: the console tty
 149  *
 150  *      Invoked by the ioctl handle for the vt layer.
 151  *
 152  *      The entire selection process is managed under the console_lock. It's
 153  *       a lot under the lock but its hardly a performance path
 154  */
 155 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 156 {
 157         struct vc_data *vc = vc_cons[fg_console].d;
 158         int sel_mode, new_sel_start, new_sel_end, spc;
 159         char *bp, *obp;
 160         int i, ps, pe, multiplier;
 161         u16 c;
 162         int mode;
 163
 164         poke_blanked_console();
 165
 166         { unsigned short xs, ys, xe, ye;
 167
 168           if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
 169                 return -EFAULT;
 170           __get_user(xs, &sel->xs);
 171           __get_user(ys, &sel->ys);
 172           __get_user(xe, &sel->xe);
 173           __get_user(ye, &sel->ye);
 174           __get_user(sel_mode, &sel->sel_mode);
 175           xs--; ys--; xe--; ye--;
 176           xs = limit(xs, vc->vc_cols - 1);
 177           ys = limit(ys, vc->vc_rows - 1);
 178           xe = limit(xe, vc->vc_cols - 1);
 179           ye = limit(ye, vc->vc_rows - 1);
 180           ps = ys * vc->vc_size_row + (xs << 1);
 181           pe = ye * vc->vc_size_row + (xe << 1);
 182
 183           if (sel_mode == TIOCL_SELCLEAR) {
 184               /* useful for screendump without selection highlights */
 185               clear_selection();
 186               return 0;
 187           }
 188
 189           if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
 190               mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
 191               return 0;
 192           }
 193         }
 194
 195         if (ps > pe)    /* make sel_start <= sel_end */
 196         {
 197                 int tmp = ps;
 198                 ps = pe;
 199                 pe = tmp;
 200         }
 201
 202         if (sel_cons != vc_cons[fg_console].d) {
 203                 clear_selection();
 204                 sel_cons = vc_cons[fg_console].d;
 205         }
 206         mode = vt_do_kdgkbmode(fg_console);
 207         if (mode == K_UNICODE)
 208                 use_unicode = 1;
 209         else
 210                 use_unicode = 0;
 211
 212         switch (sel_mode)
 213         {
 214                 case TIOCL_SELCHAR:     /* character-by-character selection */
 215                         new_sel_start = ps;
 216                         new_sel_end = pe;
 217                         break;
 218                 case TIOCL_SELWORD:     /* word-by-word selection */
 219                         spc = isspace(sel_pos(ps));
 220                         for (new_sel_start = ps; ; ps -= 2)
 221                         {
 222                                 if ((spc && !isspace(sel_pos(ps))) ||
 223                                     (!spc && !inword(sel_pos(ps))))
 224                                         break;
 225                                 new_sel_start = ps;
 226                                 if (!(ps % vc->vc_size_row))
 227                                         break;
 228                         }
 229                         spc = isspace(sel_pos(pe));
 230                         for (new_sel_end = pe; ; pe += 2)
 231                         {
 232                                 if ((spc && !isspace(sel_pos(pe))) ||
 233                                     (!spc && !inword(sel_pos(pe))))
 234                                         break;
 235                                 new_sel_end = pe;
 236                                 if (!((pe + 2) % vc->vc_size_row))
 237                                         break;
 238                         }
 239                         break;
 240                 case TIOCL_SELLINE:     /* line-by-line selection */
 241                         new_sel_start = ps - ps % vc->vc_size_row;
 242                         new_sel_end = pe + vc->vc_size_row
 243                                     - pe % vc->vc_size_row - 2;
 244                         break;
 245                 case TIOCL_SELPOINTER:
 246                         highlight_pointer(pe);
 247                         return 0;
 248                 default:
 249                         return -EINVAL;
 250         }
 251
 252         /* remove the pointer */
 253         highlight_pointer(-1);
 254
 255         /* select to end of line if on trailing space */
 256         if (new_sel_end > new_sel_start &&
 257                 !atedge(new_sel_end, vc->vc_size_row) &&
 258                 isspace(sel_pos(new_sel_end))) {
 259                 for (pe = new_sel_end + 2; ; pe += 2)
 260                         if (!isspace(sel_pos(pe)) ||
 261                             atedge(pe, vc->vc_size_row))
 262                                 break;
 263                 if (isspace(sel_pos(pe)))
 264                         new_sel_end = pe;
 265         }
 266         if (sel_start == -1)    /* no current selection */
 267                 highlight(new_sel_start, new_sel_end);
 268         else if (new_sel_start == sel_start)
 269         {
 270                 if (new_sel_end == sel_end)     /* no action required */
 271                         return 0;
 272                 else if (new_sel_end > sel_end) /* extend to right */
 273                         highlight(sel_end + 2, new_sel_end);
 274                 else                            /* contract from right */
 275                         highlight(new_sel_end + 2, sel_end);
 276         }
 277         else if (new_sel_end == sel_end)
 278         {
 279                 if (new_sel_start < sel_start)  /* extend to left */
 280                         highlight(new_sel_start, sel_start - 2);
 281                 else                            /* contract from left */
 282                         highlight(sel_start, new_sel_start - 2);
 283         }
 284         else    /* some other case; start selection from scratch */
 285         {
 286                 clear_selection();
 287                 highlight(new_sel_start, new_sel_end);
 288         }
 289         sel_start = new_sel_start;
 290         sel_end = new_sel_end;
 291
 292         /* Allocate a new buffer before freeing the old one ... */
 293         multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
 294         bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
 295         if (!bp) {
 296                 printk(KERN_WARNING "selection: kmalloc() failed\n");
 297                 clear_selection();
 298                 return -ENOMEM;
 299         }
 300         kfree(sel_buffer);
 301         sel_buffer = bp;
 302
 303         obp = bp;
 304         for (i = sel_start; i <= sel_end; i += 2) {
 305                 c = sel_pos(i);
 306                 if (use_unicode)
 307                         bp += store_utf8(c, bp);
 308                 else
 309                         *bp++ = c;
 310                 if (!isspace(c))
 311                         obp = bp;
 312                 if (! ((i + 2) % vc->vc_size_row)) {
 313                         /* strip trailing blanks from line and add newline,
 314                            unless non-space at end of line. */
 315                         if (obp != bp) {
 316                                 bp = obp;
 317                                 *bp++ = '\r';
 318                         }
 319                         obp = bp;
 320                 }
 321         }
 322         sel_buffer_lth = bp - sel_buffer;
 323         return 0;
 324 }
 325
 326 /* Insert the contents of the selection buffer into the
 327  * queue of the tty associated with the current console.
 328  * Invoked by ioctl().
 329  *
 330  * Locking: called without locks. Calls the ldisc wrongly with
 331  * unsafe methods,
 332  */
 333 int paste_selection(struct tty_struct *tty)
 334 {
 335         struct vc_data *vc = tty->driver_data;
 336         int     pasted = 0;
 337         unsigned int count;
 338         struct  tty_ldisc *ld;
 339         DECLARE_WAITQUEUE(wait, current);
 340
 341         console_lock();
 342         poke_blanked_console();
 343         console_unlock();
 344
 345         ld = tty_ldisc_ref_wait(tty);
 346         if (!ld)
 347                 return -EIO;    /* ldisc was hung up */
 348         tty_buffer_lock_exclusive(&vc->port);
 349
 350         add_wait_queue(&vc->paste_wait, &wait);
 351         while (sel_buffer && sel_buffer_lth > pasted) {
 352                 set_current_state(TASK_INTERRUPTIBLE);
 353                 if (tty_throttled(tty)) {
 354                         schedule();
 355                         continue;
 356                 }
 357                 __set_current_state(TASK_RUNNING);
 358                 count = sel_buffer_lth - pasted;
 359                 count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
 360                                               count);
 361                 pasted += count;
 362         }
 363         remove_wait_queue(&vc->paste_wait, &wait);
 364         __set_current_state(TASK_RUNNING);
 365
 366         tty_buffer_unlock_exclusive(&vc->port);
 367         tty_ldisc_deref(ld);
 368         return 0;
 369 }