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/vt_kern.h>
  24 #include <linux/consolemap.h>
  25 #include <linux/selection.h>
  26 #include <linux/tiocl.h>
  27 #include <linux/console.h>
  28
  29 #ifndef MIN
  30 #define MIN(a,b)        ((a) < (b) ? (a) : (b))
  31 #endif
  32
  33 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
  34 #define isspace(c)      ((c) == ' ')
  35
  36 extern void poke_blanked_console(void);
  37
  38 /* Variables for selection control. */
  39 /* Use a dynamic buffer, instead of static (Dec 1994) */
  40        int sel_cons;            /* must not be disallocated */
  41 static volatile int sel_start = -1;     /* cleared by clear_selection */
  42 static int sel_end;
  43 static int sel_buffer_lth;
  44 static char *sel_buffer;
  45
  46 /* clear_selection, highlight and highlight_pointer can be called
  47    from interrupt (via scrollback/front) */
  48
  49 /* set reverse video on characters s-e of console with selection. */
  50 inline static void
  51 highlight(const int s, const int e) {
  52         invert_screen(sel_cons, s, e-s+2, 1);
  53 }
  54
  55 /* use complementary color to show the pointer */
  56 inline static void
  57 highlight_pointer(const int where) {
  58         complement_pos(sel_cons, where);
  59 }
  60
  61 static unsigned char
  62 sel_pos(int n)
  63 {
  64         return inverse_translate(vc_cons[sel_cons].d, screen_glyph(sel_cons, n));
  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 unsigned char c) {
  94         return ( 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 /* set the current selection. Invoked by ioctl() or by kernel code. */
 116 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 117 {
 118         int sel_mode, new_sel_start, new_sel_end, spc;
 119         char *bp, *obp;
 120         int i, ps, pe;
 121         unsigned int currcons = fg_console;
 122
 123         poke_blanked_console();
 124
 125         { unsigned short xs, ys, xe, ye;
 126
 127           if (verify_area(VERIFY_READ, sel, sizeof(*sel)))
 128                 return -EFAULT;
 129           __get_user(xs, &sel->xs);
 130           __get_user(ys, &sel->ys);
 131           __get_user(xe, &sel->xe);
 132           __get_user(ye, &sel->ye);
 133           __get_user(sel_mode, &sel->sel_mode);
 134           xs--; ys--; xe--; ye--;
 135           xs = limit(xs, video_num_columns - 1);
 136           ys = limit(ys, video_num_lines - 1);
 137           xe = limit(xe, video_num_columns - 1);
 138           ye = limit(ye, video_num_lines - 1);
 139           ps = ys * video_size_row + (xs << 1);
 140           pe = ye * video_size_row + (xe << 1);
 141
 142           if (sel_mode == TIOCL_SELCLEAR) {
 143               /* useful for screendump without selection highlights */
 144               clear_selection();
 145               return 0;
 146           }
 147
 148           if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
 149               mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
 150               return 0;
 151           }
 152         }
 153
 154         if (ps > pe)    /* make sel_start <= sel_end */
 155         {
 156                 int tmp = ps;
 157                 ps = pe;
 158                 pe = tmp;
 159         }
 160
 161         if (sel_cons != fg_console) {
 162                 clear_selection();
 163                 sel_cons = fg_console;
 164         }
 165
 166         switch (sel_mode)
 167         {
 168                 case TIOCL_SELCHAR:     /* character-by-character selection */
 169                         new_sel_start = ps;
 170                         new_sel_end = pe;
 171                         break;
 172                 case TIOCL_SELWORD:     /* word-by-word selection */
 173                         spc = isspace(sel_pos(ps));
 174                         for (new_sel_start = ps; ; ps -= 2)
 175                         {
 176                                 if ((spc && !isspace(sel_pos(ps))) ||
 177                                     (!spc && !inword(sel_pos(ps))))
 178                                         break;
 179                                 new_sel_start = ps;
 180                                 if (!(ps % video_size_row))
 181                                         break;
 182                         }
 183                         spc = isspace(sel_pos(pe));
 184                         for (new_sel_end = pe; ; pe += 2)
 185                         {
 186                                 if ((spc && !isspace(sel_pos(pe))) ||
 187                                     (!spc && !inword(sel_pos(pe))))
 188                                         break;
 189                                 new_sel_end = pe;
 190                                 if (!((pe + 2) % video_size_row))
 191                                         break;
 192                         }
 193                         break;
 194                 case TIOCL_SELLINE:     /* line-by-line selection */
 195                         new_sel_start = ps - ps % video_size_row;
 196                         new_sel_end = pe + video_size_row
 197                                     - pe % video_size_row - 2;
 198                         break;
 199                 case TIOCL_SELPOINTER:
 200                         highlight_pointer(pe);
 201                         return 0;
 202                 default:
 203                         return -EINVAL;
 204         }
 205
 206         /* remove the pointer */
 207         highlight_pointer(-1);
 208
 209         /* select to end of line if on trailing space */
 210         if (new_sel_end > new_sel_start &&
 211                 !atedge(new_sel_end, video_size_row) &&
 212                 isspace(sel_pos(new_sel_end))) {
 213                 for (pe = new_sel_end + 2; ; pe += 2)
 214                         if (!isspace(sel_pos(pe)) ||
 215                             atedge(pe, video_size_row))
 216                                 break;
 217                 if (isspace(sel_pos(pe)))
 218                         new_sel_end = pe;
 219         }
 220         if (sel_start == -1)    /* no current selection */
 221                 highlight(new_sel_start, new_sel_end);
 222         else if (new_sel_start == sel_start)
 223         {
 224                 if (new_sel_end == sel_end)     /* no action required */
 225                         return 0;
 226                 else if (new_sel_end > sel_end) /* extend to right */
 227                         highlight(sel_end + 2, new_sel_end);
 228                 else                            /* contract from right */
 229                         highlight(new_sel_end + 2, sel_end);
 230         }
 231         else if (new_sel_end == sel_end)
 232         {
 233                 if (new_sel_start < sel_start)  /* extend to left */
 234                         highlight(new_sel_start, sel_start - 2);
 235                 else                            /* contract from left */
 236                         highlight(sel_start, new_sel_start - 2);
 237         }
 238         else    /* some other case; start selection from scratch */
 239         {
 240                 clear_selection();
 241                 highlight(new_sel_start, new_sel_end);
 242         }
 243         sel_start = new_sel_start;
 244         sel_end = new_sel_end;
 245
 246         /* Allocate a new buffer before freeing the old one ... */
 247         bp = kmalloc((sel_end-sel_start)/2+1, GFP_KERNEL);
 248         if (!bp) {
 249                 printk(KERN_WARNING "selection: kmalloc() failed\n");
 250                 clear_selection();
 251                 return -ENOMEM;
 252         }
 253         if (sel_buffer)
 254                 kfree(sel_buffer);
 255         sel_buffer = bp;
 256
 257         obp = bp;
 258         for (i = sel_start; i <= sel_end; i += 2) {
 259                 *bp = sel_pos(i);
 260                 if (!isspace(*bp++))
 261                         obp = bp;
 262                 if (! ((i + 2) % video_size_row)) {
 263                         /* strip trailing blanks from line and add newline,
 264                            unless non-space at end of line. */
 265                         if (obp != bp) {
 266                                 bp = obp;
 267                                 *bp++ = '\r';
 268                         }
 269                         obp = bp;
 270                 }
 271         }
 272         sel_buffer_lth = bp - sel_buffer;
 273         return 0;
 274 }
 275
 276 /* Insert the contents of the selection buffer into the
 277  * queue of the tty associated with the current console.
 278  * Invoked by ioctl().
 279  */
 280 int paste_selection(struct tty_struct *tty)
 281 {
 282         struct vt_struct *vt = (struct vt_struct *) tty->driver_data;
 283         int     pasted = 0, count;
 284         DECLARE_WAITQUEUE(wait, current);
 285
 286         acquire_console_sem();
 287         poke_blanked_console();
 288         release_console_sem();
 289
 290         add_wait_queue(&vt->paste_wait, &wait);
 291         while (sel_buffer && sel_buffer_lth > pasted) {
 292                 set_current_state(TASK_INTERRUPTIBLE);
 293                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 294                         schedule();
 295                         continue;
 296                 }
 297                 count = sel_buffer_lth - pasted;
 298                 count = MIN(count, tty->ldisc.receive_room(tty));
 299                 tty->ldisc.receive_buf(tty, sel_buffer + pasted, 0, count);
 300                 pasted += count;
 301         }
 302         remove_wait_queue(&vt->paste_wait, &wait);
 303         current->state = TASK_RUNNING;
 304         return 0;
 305 }
 306
 307 EXPORT_SYMBOL(set_selection);
 308 EXPORT_SYMBOL(paste_selection);