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