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/kbd_kern.h>
  24 #include <linux/vt_kern.h>
  25 #include <linux/consolemap.h>
  26 #include <linux/selection.h>
  27 #include <linux/tiocl.h>
  28 #include <linux/console.h>
  29 #include <linux/smp_lock.h>
  30
  31 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
  32 #define isspace(c)      ((c) == ' ')
  33
  34 extern void poke_blanked_console(void);
  35
  36 /* Variables for selection control. */
  37 /* Use a dynamic buffer, instead of static (Dec 1994) */
  38 struct vc_data *sel_cons;               /* must not be deallocated */
  39 static int use_unicode;
  40 static volatile int sel_start = -1;     /* cleared by clear_selection */
  41 static int sel_end;
  42 static int sel_buffer_lth;
  43 static char *sel_buffer;
  44
  45 /* clear_selection, highlight and highlight_pointer can be called
  46    from interrupt (via scrollback/front) */
  47
  48 /* set reverse video on characters s-e of console with selection. */
  49 static inline void highlight(const int s, const int e)
  50 {
  51         invert_screen(sel_cons, s, e-s+2, 1);
  52 }
  53
  54 /* use complementary color to show the pointer */
  55 static inline void highlight_pointer(const int where)
  56 {
  57         complement_pos(sel_cons, where);
  58 }
  59
  60 static u16
  61 sel_pos(int n)
  62 {
  63         return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
  64                                 use_unicode);
  65 }
  66
  67 /* remove the current selection highlight, if any,
  68    from the console holding the selection. */
  69 void
  70 clear_selection(void) {
  71         highlight_pointer(-1); /* hide the pointer */
  72         if (sel_start != -1) {
  73                 highlight(sel_start, sel_end);
  74                 sel_start = -1;
  75         }
  76 }
  77
  78 /*
  79  * User settable table: what characters are to be considered alphabetic?
  80  * 256 bits
  81  */
  82 static u32 inwordLut[8]={
  83   0x00000000, /* control chars     */
  84   0x03FF0000, /* digits            */
  85   0x87FFFFFE, /* uppercase and '_' */
  86   0x07FFFFFE, /* lowercase         */
  87   0x00000000,
  88   0x00000000,
  89   0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
  90   0xFF7FFFFF  /* latin-1 accented letters, not division sign */
  91 };
  92
  93 static inline int inword(const u16 c) {
  94         return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
  95 }
  96
  97 /* set inwordLut contents. Invoked by ioctl(). */
  98 int sel_loadlut(char __user *p)
  99 {
 100         return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
 101 }
 102
 103 /* does screen address p correspond to character at LH/RH edge of screen? */
 104 static inline int atedge(const int p, int size_row)
 105 {
 106         return (!(p % size_row) || !((p + 2) % size_row));
 107 }
 108
 109 /* constrain v such that v <= u */
 110 static inline unsigned short limit(const unsigned short v, const unsigned short u)
 111 {
 112         return (v > u) ? u : v;
 113 }
 114
 115 /* stores the char in UTF8 and returns the number of bytes used (1-3) */
 116 static int store_utf8(u16 c, char *p)
 117 {
 118         if (c < 0x80) {
 119                 /*  0******* */
 120                 p[0] = c;
 121                 return 1;
 122         } else if (c < 0x800) {
 123                 /* 110***** 10****** */
 124                 p[0] = 0xc0 | (c >> 6);
 125                 p[1] = 0x80 | (c & 0x3f);
 126                 return 2;
 127         } else {
 128                 /* 1110**** 10****** 10****** */
 129                 p[0] = 0xe0 | (c >> 12);
 130                 p[1] = 0x80 | ((c >> 6) & 0x3f);
 131                 p[2] = 0x80 | (c & 0x3f);
 132                 return 3;
 133         }
 134 }
 135
 136 /* set the current selection. Invoked by ioctl() or by kernel code. */
 137 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 138 {
 139         struct vc_data *vc = vc_cons[fg_console].d;
 140         int sel_mode, new_sel_start, new_sel_end, spc;
 141         char *bp, *obp;
 142         int i, ps, pe, multiplier;
 143         u16 c;
 144         struct kbd_struct *kbd = kbd_table + fg_console;
 145
 146         poke_blanked_console();
 147
 148         { unsigned short xs, ys, xe, ye;
 149
 150           if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
 151                 return -EFAULT;
 152           __get_user(xs, &sel->xs);
 153           __get_user(ys, &sel->ys);
 154           __get_user(xe, &sel->xe);
 155           __get_user(ye, &sel->ye);
 156           __get_user(sel_mode, &sel->sel_mode);
 157           xs--; ys--; xe--; ye--;
 158           xs = limit(xs, vc->vc_cols - 1);
 159           ys = limit(ys, vc->vc_rows - 1);
 160           xe = limit(xe, vc->vc_cols - 1);
 161           ye = limit(ye, vc->vc_rows - 1);
 162           ps = ys * vc->vc_size_row + (xs << 1);
 163           pe = ye * vc->vc_size_row + (xe << 1);
 164
 165           if (sel_mode == TIOCL_SELCLEAR) {
 166               /* useful for screendump without selection highlights */
 167               clear_selection();
 168               return 0;
 169           }
 170
 171           if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
 172               mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
 173               return 0;
 174           }
 175         }
 176
 177         if (ps > pe)    /* make sel_start <= sel_end */
 178         {
 179                 int tmp = ps;
 180                 ps = pe;
 181                 pe = tmp;
 182         }
 183
 184         if (sel_cons != vc_cons[fg_console].d) {
 185                 clear_selection();
 186                 sel_cons = vc_cons[fg_console].d;
 187         }
 188         use_unicode = kbd && kbd->kbdmode == VC_UNICODE;
 189
 190         switch (sel_mode)
 191         {
 192                 case TIOCL_SELCHAR:     /* character-by-character selection */
 193                         new_sel_start = ps;
 194                         new_sel_end = pe;
 195                         break;
 196                 case TIOCL_SELWORD:     /* word-by-word selection */
 197                         spc = isspace(sel_pos(ps));
 198                         for (new_sel_start = ps; ; ps -= 2)
 199                         {
 200                                 if ((spc && !isspace(sel_pos(ps))) ||
 201                                     (!spc && !inword(sel_pos(ps))))
 202                                         break;
 203                                 new_sel_start = ps;
 204                                 if (!(ps % vc->vc_size_row))
 205                                         break;
 206                         }
 207                         spc = isspace(sel_pos(pe));
 208                         for (new_sel_end = pe; ; pe += 2)
 209                         {
 210                                 if ((spc && !isspace(sel_pos(pe))) ||
 211                                     (!spc && !inword(sel_pos(pe))))
 212                                         break;
 213                                 new_sel_end = pe;
 214                                 if (!((pe + 2) % vc->vc_size_row))
 215                                         break;
 216                         }
 217                         break;
 218                 case TIOCL_SELLINE:     /* line-by-line selection */
 219                         new_sel_start = ps - ps % vc->vc_size_row;
 220                         new_sel_end = pe + vc->vc_size_row
 221                                     - pe % vc->vc_size_row - 2;
 222                         break;
 223                 case TIOCL_SELPOINTER:
 224                         highlight_pointer(pe);
 225                         return 0;
 226                 default:
 227                         return -EINVAL;
 228         }
 229
 230         /* remove the pointer */
 231         highlight_pointer(-1);
 232
 233         /* select to end of line if on trailing space */
 234         if (new_sel_end > new_sel_start &&
 235                 !atedge(new_sel_end, vc->vc_size_row) &&
 236                 isspace(sel_pos(new_sel_end))) {
 237                 for (pe = new_sel_end + 2; ; pe += 2)
 238                         if (!isspace(sel_pos(pe)) ||
 239                             atedge(pe, vc->vc_size_row))
 240                                 break;
 241                 if (isspace(sel_pos(pe)))
 242                         new_sel_end = pe;
 243         }
 244         if (sel_start == -1)    /* no current selection */
 245                 highlight(new_sel_start, new_sel_end);
 246         else if (new_sel_start == sel_start)
 247         {
 248                 if (new_sel_end == sel_end)     /* no action required */
 249                         return 0;
 250                 else if (new_sel_end > sel_end) /* extend to right */
 251                         highlight(sel_end + 2, new_sel_end);
 252                 else                            /* contract from right */
 253                         highlight(new_sel_end + 2, sel_end);
 254         }
 255         else if (new_sel_end == sel_end)
 256         {
 257                 if (new_sel_start < sel_start)  /* extend to left */
 258                         highlight(new_sel_start, sel_start - 2);
 259                 else                            /* contract from left */
 260                         highlight(sel_start, new_sel_start - 2);
 261         }
 262         else    /* some other case; start selection from scratch */
 263         {
 264                 clear_selection();
 265                 highlight(new_sel_start, new_sel_end);
 266         }
 267         sel_start = new_sel_start;
 268         sel_end = new_sel_end;
 269
 270         /* Allocate a new buffer before freeing the old one ... */
 271         multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
 272         bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
 273         if (!bp) {
 274                 printk(KERN_WARNING "selection: kmalloc() failed\n");
 275                 clear_selection();
 276                 return -ENOMEM;
 277         }
 278         kfree(sel_buffer);
 279         sel_buffer = bp;
 280
 281         obp = bp;
 282         for (i = sel_start; i <= sel_end; i += 2) {
 283                 c = sel_pos(i);
 284                 if (use_unicode)
 285                         bp += store_utf8(c, bp);
 286                 else
 287                         *bp++ = c;
 288                 if (!isspace(c))
 289                         obp = bp;
 290                 if (! ((i + 2) % vc->vc_size_row)) {
 291                         /* strip trailing blanks from line and add newline,
 292                            unless non-space at end of line. */
 293                         if (obp != bp) {
 294                                 bp = obp;
 295                                 *bp++ = '\r';
 296                         }
 297                         obp = bp;
 298                 }
 299         }
 300         sel_buffer_lth = bp - sel_buffer;
 301         return 0;
 302 }
 303
 304 /* Insert the contents of the selection buffer into the
 305  * queue of the tty associated with the current console.
 306  * Invoked by ioctl().
 307  */
 308 int paste_selection(struct tty_struct *tty)
 309 {
 310         struct vc_data *vc = tty->driver_data;
 311         int     pasted = 0;
 312         unsigned int count;
 313         struct  tty_ldisc *ld;
 314         DECLARE_WAITQUEUE(wait, current);
 315
 316         /* always called with BTM from vt_ioctl */
 317         WARN_ON(!tty_locked());
 318
 319         acquire_console_sem();
 320         poke_blanked_console();
 321         release_console_sem();
 322
 323         ld = tty_ldisc_ref(tty);
 324         if (!ld) {
 325                 tty_unlock();
 326                 ld = tty_ldisc_ref_wait(tty);
 327                 tty_lock();
 328         }
 329
 330         add_wait_queue(&vc->paste_wait, &wait);
 331         while (sel_buffer && sel_buffer_lth > pasted) {
 332                 set_current_state(TASK_INTERRUPTIBLE);
 333                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 334                         schedule();
 335                         continue;
 336                 }
 337                 count = sel_buffer_lth - pasted;
 338                 count = min(count, tty->receive_room);
 339                 tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
 340                                                                 NULL, count);
 341                 pasted += count;
 342         }
 343         remove_wait_queue(&vc->paste_wait, &wait);
 344         __set_current_state(TASK_RUNNING);
 345
 346         tty_ldisc_deref(ld);
 347         return 0;
 348 }