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
  28/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
  29#define isspace(c)      ((c) == ' ')
  30
  31extern 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) */
  36struct vc_data *sel_cons;               /* must not be deallocated */
  37static int use_unicode;
  38static volatile int sel_start = -1;     /* cleared by clear_selection */
  39static int sel_end;
  40static int sel_buffer_lth;
  41static 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. */
  47static 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 */
  53static inline void highlight_pointer(const int where)
  54{
  55        complement_pos(sel_cons, where);
  56}
  57
  58static u16
  59sel_pos(int n)
  60{
  61        return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
  62                                use_unicode);
  63}
  64
  65/**
  66 *      clear_selection         -       remove current selection
  67 *
  68 *      Remove the current selection highlight, if any from the console
  69 *      holding the selection. The caller must hold the console lock.
  70 */
  71void clear_selection(void)
  72{
  73        highlight_pointer(-1); /* hide the pointer */
  74        if (sel_start != -1) {
  75                highlight(sel_start, sel_end);
  76                sel_start = -1;
  77        }
  78}
  79
  80/*
  81 * User settable table: what characters are to be considered alphabetic?
  82 * 256 bits. Locked by the console lock.
  83 */
  84static u32 inwordLut[8]={
  85  0x00000000, /* control chars     */
  86  0x03FF0000, /* digits            */
  87  0x87FFFFFE, /* uppercase and '_' */
  88  0x07FFFFFE, /* lowercase         */
  89  0x00000000,
  90  0x00000000,
  91  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
  92  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
  93};
  94
  95static inline int inword(const u16 c) {
  96        return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
  97}
  98
  99/**
 100 *      set loadlut             -       load the LUT table
 101 *      @p: user table
 102 *
 103 *      Load the LUT table from user space. The caller must hold the console
 104 *      lock. Make a temporary copy so a partial update doesn't make a mess.
 105 */
 106int sel_loadlut(char __user *p)
 107{
 108        u32 tmplut[8];
 109        if (copy_from_user(tmplut, (u32 __user *)(p+4), 32))
 110                return -EFAULT;
 111        memcpy(inwordLut, tmplut, 32);
 112        return 0;
 113}
 114
 115/* does screen address p correspond to character at LH/RH edge of screen? */
 116static inline int atedge(const int p, int size_row)
 117{
 118        return (!(p % size_row) || !((p + 2) % size_row));
 119}
 120
 121/* constrain v such that v <= u */
 122static inline unsigned short limit(const unsigned short v, const unsigned short u)
 123{
 124        return (v > u) ? u : v;
 125}
 126
 127/* stores the char in UTF8 and returns the number of bytes used (1-3) */
 128static int store_utf8(u16 c, char *p)
 129{
 130        if (c < 0x80) {
 131                /*  0******* */
 132                p[0] = c;
 133                return 1;
 134        } else if (c < 0x800) {
 135                /* 110***** 10****** */
 136                p[0] = 0xc0 | (c >> 6);
 137                p[1] = 0x80 | (c & 0x3f);
 138                return 2;
 139        } else {
 140                /* 1110**** 10****** 10****** */
 141                p[0] = 0xe0 | (c >> 12);
 142                p[1] = 0x80 | ((c >> 6) & 0x3f);
 143                p[2] = 0x80 | (c & 0x3f);
 144                return 3;
 145        }
 146}
 147
 148/**
 149 *      set_selection           -       set the current selection.
 150 *      @sel: user selection info
 151 *      @tty: the console tty
 152 *
 153 *      Invoked by the ioctl handle for the vt layer.
 154 *
 155 *      The entire selection process is managed under the console_lock. It's
 156 *       a lot under the lock but its hardly a performance path
 157 */
 158int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 159{
 160        struct vc_data *vc = vc_cons[fg_console].d;
 161        int sel_mode, new_sel_start, new_sel_end, spc;
 162        char *bp, *obp;
 163        int i, ps, pe, multiplier;
 164        u16 c;
 165        int mode;
 166
 167        poke_blanked_console();
 168
 169        { unsigned short xs, ys, xe, ye;
 170
 171          if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
 172                return -EFAULT;
 173          __get_user(xs, &sel->xs);
 174          __get_user(ys, &sel->ys);
 175          __get_user(xe, &sel->xe);
 176          __get_user(ye, &sel->ye);
 177          __get_user(sel_mode, &sel->sel_mode);
 178          xs--; ys--; xe--; ye--;
 179          xs = limit(xs, vc->vc_cols - 1);
 180          ys = limit(ys, vc->vc_rows - 1);
 181          xe = limit(xe, vc->vc_cols - 1);
 182          ye = limit(ye, vc->vc_rows - 1);
 183          ps = ys * vc->vc_size_row + (xs << 1);
 184          pe = ye * vc->vc_size_row + (xe << 1);
 185
 186          if (sel_mode == TIOCL_SELCLEAR) {
 187              /* useful for screendump without selection highlights */
 188              clear_selection();
 189              return 0;
 190          }
 191
 192          if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
 193              mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
 194              return 0;
 195          }
 196        }
 197
 198        if (ps > pe)    /* make sel_start <= sel_end */
 199        {
 200                int tmp = ps;
 201                ps = pe;
 202                pe = tmp;
 203        }
 204
 205        if (sel_cons != vc_cons[fg_console].d) {
 206                clear_selection();
 207                sel_cons = vc_cons[fg_console].d;
 208        }
 209        mode = vt_do_kdgkbmode(fg_console);
 210        if (mode == K_UNICODE)
 211                use_unicode = 1;
 212        else
 213                use_unicode = 0;
 214
 215        switch (sel_mode)
 216        {
 217                case TIOCL_SELCHAR:     /* character-by-character selection */
 218                        new_sel_start = ps;
 219                        new_sel_end = pe;
 220                        break;
 221                case TIOCL_SELWORD:     /* word-by-word selection */
 222                        spc = isspace(sel_pos(ps));
 223                        for (new_sel_start = ps; ; ps -= 2)
 224                        {
 225                                if ((spc && !isspace(sel_pos(ps))) ||
 226                                    (!spc && !inword(sel_pos(ps))))
 227                                        break;
 228                                new_sel_start = ps;
 229                                if (!(ps % vc->vc_size_row))
 230                                        break;
 231                        }
 232                        spc = isspace(sel_pos(pe));
 233                        for (new_sel_end = pe; ; pe += 2)
 234                        {
 235                                if ((spc && !isspace(sel_pos(pe))) ||
 236                                    (!spc && !inword(sel_pos(pe))))
 237                                        break;
 238                                new_sel_end = pe;
 239                                if (!((pe + 2) % vc->vc_size_row))
 240                                        break;
 241                        }
 242                        break;
 243                case TIOCL_SELLINE:     /* line-by-line selection */
 244                        new_sel_start = ps - ps % vc->vc_size_row;
 245                        new_sel_end = pe + vc->vc_size_row
 246                                    - pe % vc->vc_size_row - 2;
 247                        break;
 248                case TIOCL_SELPOINTER:
 249                        highlight_pointer(pe);
 250                        return 0;
 251                default:
 252                        return -EINVAL;
 253        }
 254
 255        /* remove the pointer */
 256        highlight_pointer(-1);
 257
 258        /* select to end of line if on trailing space */
 259        if (new_sel_end > new_sel_start &&
 260                !atedge(new_sel_end, vc->vc_size_row) &&
 261                isspace(sel_pos(new_sel_end))) {
 262                for (pe = new_sel_end + 2; ; pe += 2)
 263                        if (!isspace(sel_pos(pe)) ||
 264                            atedge(pe, vc->vc_size_row))
 265                                break;
 266                if (isspace(sel_pos(pe)))
 267                        new_sel_end = pe;
 268        }
 269        if (sel_start == -1)    /* no current selection */
 270                highlight(new_sel_start, new_sel_end);
 271        else if (new_sel_start == sel_start)
 272        {
 273                if (new_sel_end == sel_end)     /* no action required */
 274                        return 0;
 275                else if (new_sel_end > sel_end) /* extend to right */
 276                        highlight(sel_end + 2, new_sel_end);
 277                else                            /* contract from right */
 278                        highlight(new_sel_end + 2, sel_end);
 279        }
 280        else if (new_sel_end == sel_end)
 281        {
 282                if (new_sel_start < sel_start)  /* extend to left */
 283                        highlight(new_sel_start, sel_start - 2);
 284                else                            /* contract from left */
 285                        highlight(sel_start, new_sel_start - 2);
 286        }
 287        else    /* some other case; start selection from scratch */
 288        {
 289                clear_selection();
 290                highlight(new_sel_start, new_sel_end);
 291        }
 292        sel_start = new_sel_start;
 293        sel_end = new_sel_end;
 294
 295        /* Allocate a new buffer before freeing the old one ... */
 296        multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
 297        bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
 298        if (!bp) {
 299                printk(KERN_WARNING "selection: kmalloc() failed\n");
 300                clear_selection();
 301                return -ENOMEM;
 302        }
 303        kfree(sel_buffer);
 304        sel_buffer = bp;
 305
 306        obp = bp;
 307        for (i = sel_start; i <= sel_end; i += 2) {
 308                c = sel_pos(i);
 309                if (use_unicode)
 310                        bp += store_utf8(c, bp);
 311                else
 312                        *bp++ = c;
 313                if (!isspace(c))
 314                        obp = bp;
 315                if (! ((i + 2) % vc->vc_size_row)) {
 316                        /* strip trailing blanks from line and add newline,
 317                           unless non-space at end of line. */
 318                        if (obp != bp) {
 319                                bp = obp;
 320                                *bp++ = '\r';
 321                        }
 322                        obp = bp;
 323                }
 324        }
 325        sel_buffer_lth = bp - sel_buffer;
 326        return 0;
 327}
 328
 329/* Insert the contents of the selection buffer into the
 330 * queue of the tty associated with the current console.
 331 * Invoked by ioctl().
 332 *
 333 * Locking: called without locks. Calls the ldisc wrongly with
 334 * unsafe methods,
 335 */
 336int paste_selection(struct tty_struct *tty)
 337{
 338        struct vc_data *vc = tty->driver_data;
 339        int     pasted = 0;
 340        unsigned int count;
 341        struct  tty_ldisc *ld;
 342        DECLARE_WAITQUEUE(wait, current);
 343
 344
 345        console_lock();
 346        poke_blanked_console();
 347        console_unlock();
 348
 349        /* FIXME: wtf is this supposed to achieve ? */
 350        ld = tty_ldisc_ref(tty);
 351        if (!ld)
 352                ld = tty_ldisc_ref_wait(tty);
 353
 354        /* FIXME: this is completely unsafe */
 355        add_wait_queue(&vc->paste_wait, &wait);
 356        while (sel_buffer && sel_buffer_lth > pasted) {
 357                set_current_state(TASK_INTERRUPTIBLE);
 358                if (test_bit(TTY_THROTTLED, &tty->flags)) {
 359                        schedule();
 360                        continue;
 361                }
 362                count = sel_buffer_lth - pasted;
 363                count = min(count, tty->receive_room);
 364                tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
 365                                                                NULL, count);
 366                pasted += count;
 367        }
 368        remove_wait_queue(&vc->paste_wait, &wait);
 369        __set_current_state(TASK_RUNNING);
 370
 371        tty_ldisc_deref(ld);
 372        return 0;
 373}
 374