LXR linux/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#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
  32extern 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) */
  37struct vc_data *sel_cons;               /* must not be deallocated */
  38static int use_unicode;
  39static volatile int sel_start = -1;     /* cleared by clear_selection */
  40static int sel_end;
  41static int sel_buffer_lth;
  42static 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. */
  48static 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 */
  54static inline void highlight_pointer(const int where)
  55{
  56        complement_pos(sel_cons, where);
  57}
  58
  59static u16
  60sel_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 */
  72void 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 * 256 bits. Locked by the console lock.
  84 */
  85static u32 inwordLut[8]={
  86  0x00000000, /* control chars     */
  87  0x03FF0000, /* digits            */
  88  0x87FFFFFE, /* uppercase and '_' */
  89  0x07FFFFFE, /* lowercase         */
  90  0x00000000,
  91  0x00000000,
  92  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
  93  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
  94};
  95
  96static inline int inword(const u16 c) {
  97        return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
  98}
  99
 100/**
 101 *      set loadlut             -       load the LUT table
 102 *      @p: user table
 103 *
 104 *      Load the LUT table from user space. The caller must hold the console
 105 *      lock. Make a temporary copy so a partial update doesn't make a mess.
 106 */
 107int sel_loadlut(char __user *p)
 108{
 109        u32 tmplut[8];
 110        if (copy_from_user(tmplut, (u32 __user *)(p+4), 32))
 111                return -EFAULT;
 112        memcpy(inwordLut, tmplut, 32);
 113        return 0;
 114}
 115
 116/* does screen address p correspond to character at LH/RH edge of screen? */
 117static inline int atedge(const int p, int size_row)
 118{
 119        return (!(p % size_row) || !((p + 2) % size_row));
 120}
 121
 122/* constrain v such that v <= u */
 123static inline unsigned short limit(const unsigned short v, const unsigned short u)
 124{
 125        return (v > u) ? u : v;
 126}
 127
 128/* stores the char in UTF8 and returns the number of bytes used (1-3) */
 129static int store_utf8(u16 c, char *p)
 130{
 131        if (c < 0x80) {
 132                /*  0******* */
 133                p[0] = c;
 134                return 1;
 135        } else if (c < 0x800) {
 136                /* 110***** 10****** */
 137                p[0] = 0xc0 | (c >> 6);
 138                p[1] = 0x80 | (c & 0x3f);
 139                return 2;
 140        } else {
 141                /* 1110**** 10****** 10****** */
 142                p[0] = 0xe0 | (c >> 12);
 143                p[1] = 0x80 | ((c >> 6) & 0x3f);
 144                p[2] = 0x80 | (c & 0x3f);
 145                return 3;
 146        }
 147}
 148
 149/**
 150 *      set_selection           -       set the current selection.
 151 *      @sel: user selection info
 152 *      @tty: the console tty
 153 *
 154 *      Invoked by the ioctl handle for the vt layer.
 155 *
 156 *      The entire selection process is managed under the console_lock. It's
 157 *       a lot under the lock but its hardly a performance path
 158 */
 159int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 160{
 161        struct vc_data *vc = vc_cons[fg_console].d;
 162        int sel_mode, new_sel_start, new_sel_end, spc;
 163        char *bp, *obp;
 164        int i, ps, pe, multiplier;
 165        u16 c;
 166        int mode;
 167
 168        poke_blanked_console();
 169
 170        { unsigned short xs, ys, xe, ye;
 171
 172          if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
 173                return -EFAULT;
 174          __get_user(xs, &sel->xs);
 175          __get_user(ys, &sel->ys);
 176          __get_user(xe, &sel->xe);
 177          __get_user(ye, &sel->ye);
 178          __get_user(sel_mode, &sel->sel_mode);
 179          xs--; ys--; xe--; ye--;
 180          xs = limit(xs, vc->vc_cols - 1);
 181          ys = limit(ys, vc->vc_rows - 1);
 182          xe = limit(xe, vc->vc_cols - 1);
 183          ye = limit(ye, vc->vc_rows - 1);
 184          ps = ys * vc->vc_size_row + (xs << 1);
 185          pe = ye * vc->vc_size_row + (xe << 1);
 186
 187          if (sel_mode == TIOCL_SELCLEAR) {
 188              /* useful for screendump without selection highlights */
 189              clear_selection();
 190              return 0;
 191          }
 192
 193          if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
 194              mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
 195              return 0;
 196          }
 197        }
 198
 199        if (ps > pe)    /* make sel_start <= sel_end */
 200        {
 201                int tmp = ps;
 202                ps = pe;
 203                pe = tmp;
 204        }
 205
 206        if (sel_cons != vc_cons[fg_console].d) {
 207                clear_selection();
 208                sel_cons = vc_cons[fg_console].d;
 209        }
 210        mode = vt_do_kdgkbmode(fg_console);
 211        if (mode == K_UNICODE)
 212                use_unicode = 1;
 213        else
 214                use_unicode = 0;
 215
 216        switch (sel_mode)
 217        {
 218                case TIOCL_SELCHAR:     /* character-by-character selection */
 219                        new_sel_start = ps;
 220                        new_sel_end = pe;
 221                        break;
 222                case TIOCL_SELWORD:     /* word-by-word selection */
 223                        spc = isspace(sel_pos(ps));
 224                        for (new_sel_start = ps; ; ps -= 2)
 225                        {
 226                                if ((spc && !isspace(sel_pos(ps))) ||
 227                                    (!spc && !inword(sel_pos(ps))))
 228                                        break;
 229                                new_sel_start = ps;
 230                                if (!(ps % vc->vc_size_row))
 231                                        break;
 232                        }
 233                        spc = isspace(sel_pos(pe));
 234                        for (new_sel_end = pe; ; pe += 2)
 235                        {
 236                                if ((spc && !isspace(sel_pos(pe))) ||
 237                                    (!spc && !inword(sel_pos(pe))))
 238                                        break;
 239                                new_sel_end = pe;
 240                                if (!((pe + 2) % vc->vc_size_row))
 241                                        break;
 242                        }
 243                        break;
 244                case TIOCL_SELLINE:     /* line-by-line selection */
 245                        new_sel_start = ps - ps % vc->vc_size_row;
 246                        new_sel_end = pe + vc->vc_size_row
 247                                    - pe % vc->vc_size_row - 2;
 248                        break;
 249                case TIOCL_SELPOINTER:
 250                        highlight_pointer(pe);
 251                        return 0;
 252                default:
 253                        return -EINVAL;
 254        }
 255
 256        /* remove the pointer */
 257        highlight_pointer(-1);
 258
 259        /* select to end of line if on trailing space */
 260        if (new_sel_end > new_sel_start &&
 261                !atedge(new_sel_end, vc->vc_size_row) &&
 262                isspace(sel_pos(new_sel_end))) {
 263                for (pe = new_sel_end + 2; ; pe += 2)
 264                        if (!isspace(sel_pos(pe)) ||
 265                            atedge(pe, vc->vc_size_row))
 266                                break;
 267                if (isspace(sel_pos(pe)))
 268                        new_sel_end = pe;
 269        }
 270        if (sel_start == -1)    /* no current selection */
 271                highlight(new_sel_start, new_sel_end);
 272        else if (new_sel_start == sel_start)
 273        {
 274                if (new_sel_end == sel_end)     /* no action required */
 275                        return 0;
 276                else if (new_sel_end > sel_end) /* extend to right */
 277                        highlight(sel_end + 2, new_sel_end);
 278                else                            /* contract from right */
 279                        highlight(new_sel_end + 2, sel_end);
 280        }
 281        else if (new_sel_end == sel_end)
 282        {
 283                if (new_sel_start < sel_start)  /* extend to left */
 284                        highlight(new_sel_start, sel_start - 2);
 285                else                            /* contract from left */
 286                        highlight(sel_start, new_sel_start - 2);
 287        }
 288        else    /* some other case; start selection from scratch */
 289        {
 290                clear_selection();
 291                highlight(new_sel_start, new_sel_end);
 292        }
 293        sel_start = new_sel_start;
 294        sel_end = new_sel_end;
 295
 296        /* Allocate a new buffer before freeing the old one ... */
 297        multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
 298        bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
 299        if (!bp) {
 300                printk(KERN_WARNING "selection: kmalloc() failed\n");
 301                clear_selection();
 302                return -ENOMEM;
 303        }
 304        kfree(sel_buffer);
 305        sel_buffer = bp;
 306
 307        obp = bp;
 308        for (i = sel_start; i <= sel_end; i += 2) {
 309                c = sel_pos(i);
 310                if (use_unicode)
 311                        bp += store_utf8(c, bp);
 312                else
 313                        *bp++ = c;
 314                if (!isspace(c))
 315                        obp = bp;
 316                if (! ((i + 2) % vc->vc_size_row)) {
 317                        /* strip trailing blanks from line and add newline,
 318                           unless non-space at end of line. */
 319                        if (obp != bp) {
 320                                bp = obp;
 321                                *bp++ = '\r';
 322                        }
 323                        obp = bp;
 324                }
 325        }
 326        sel_buffer_lth = bp - sel_buffer;
 327        return 0;
 328}
 329
 330/* Insert the contents of the selection buffer into the
 331 * queue of the tty associated with the current console.
 332 * Invoked by ioctl().
 333 *
 334 * Locking: called without locks. Calls the ldisc wrongly with
 335 * unsafe methods,
 336 */
 337int paste_selection(struct tty_struct *tty)
 338{
 339        struct vc_data *vc = tty->driver_data;
 340        int     pasted = 0;
 341        unsigned int count;
 342        struct  tty_ldisc *ld;
 343        DECLARE_WAITQUEUE(wait, current);
 344
 345        console_lock();
 346        poke_blanked_console();
 347        console_unlock();
 348
 349        ld = tty_ldisc_ref_wait(tty);
 350        tty_buffer_lock_exclusive(&vc->port);
 351
 352        add_wait_queue(&vc->paste_wait, &wait);
 353        while (sel_buffer && sel_buffer_lth > pasted) {
 354                set_current_state(TASK_INTERRUPTIBLE);
 355                if (test_bit(TTY_THROTTLED, &tty->flags)) {
 356                        schedule();
 357                        continue;
 358                }
 359                count = sel_buffer_lth - pasted;
 360                count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
 361                                              count);
 362                pasted += count;
 363        }
 364        remove_wait_queue(&vc->paste_wait, &wait);
 365        __set_current_state(TASK_RUNNING);
 366
 367        tty_buffer_unlock_exclusive(&vc->port);
 368        tty_ldisc_deref(ld);
 369        return 0;
 370}
 371