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