misc.cxx

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//==========================================================================
//
//      misc.cxx
//
//      Fileio miscellaneous functions
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
// Copyright (C) 2003 Gary Thomas
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):           nickg
// Contributors:        nickg
// Date:                2000-05-25
// Purpose:             Fileio miscellaneous functions
// Description:         This file contains various miscellaneous functions
//                      for use with the fileio system. These include startup,
//                      table management, and other service routines.
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <pkgconf/system.h>
#include <pkgconf/hal.h>
#include <pkgconf/io_fileio.h>
#ifdef CYGPKG_LIBC_TIME
#include <pkgconf/libc_time.h>
#endif


#include <cyg/infra/cyg_trac.h>        // tracing macros
#include <cyg/infra/cyg_ass.h>         // assertion macros
#include <string.h>                    // strcmp()
#include <time.h>                      // time()

#ifdef CYGPKG_IO_WALLCLOCK
# include <cyg/io/wallclock.hxx>       // Wallclock class
#endif

#ifdef CYGPKG_KERNEL
#include <pkgconf/kernel.h>
#include <cyg/kernel/ktypes.h>         // base kernel types
#include <cyg/kernel/clock.inl>         // Clock inlines
#endif

#include "fio.h"                       // Private header

//==========================================================================
// forward definitions

static void cyg_mtab_init();

__externC int chdir( const char *path );

//==========================================================================
// Filesystem tables

// -------------------------------------------------------------------------
// Filesystem table.

// This array contains entries for all filesystem that are installed in
// the system.
__externC cyg_fstab_entry cyg_fstab[];
CYG_HAL_TABLE_BEGIN( cyg_fstab, fstab );

// end of filesystem table, set in linker script.
__externC cyg_fstab_entry cyg_fstab_end;
CYG_HAL_TABLE_END( cyg_fstab_end, fstab );

#ifdef CYGPKG_KERNEL
// Array of mutexes for locking the fstab entries
static Cyg_Mutex fstab_lock[CYGNUM_FILEIO_FSTAB_MAX] CYGBLD_ATTRIB_INIT_PRI(CYG_INIT_IO_FS);
#endif

// -------------------------------------------------------------------------
// Mount table.

// This array contains entries for all valid running filesystems.
__externC cyg_mtab_entry cyg_mtab[];
CYG_HAL_TABLE_BEGIN( cyg_mtab, mtab );

// Extra entries at end of mtab for dynamic mount points.
#if CYGNUM_FILEIO_MTAB_EXTRA > 0
cyg_mtab_entry cyg_mtab_extra[CYGNUM_FILEIO_MTAB_EXTRA] CYG_HAL_TABLE_EXTRA(mtab) = { { NULL } };
#endif
// End of mount table, set in the linker script.
__externC cyg_mtab_entry cyg_mtab_end;
CYG_HAL_TABLE_END( cyg_mtab_end, mtab );

#ifdef CYGPKG_KERNEL
// Array of mutexes for locking the mtab entries
static Cyg_Mutex mtab_lock[CYGNUM_FILEIO_MTAB_MAX] CYGBLD_ATTRIB_INIT_PRI(CYG_INIT_IO_FS);
#endif

//==========================================================================
// Current directory

cyg_mtab_entry *cyg_cdir_mtab_entry = NULL;
cyg_dir cyg_cdir_dir = CYG_DIR_NULL;

//==========================================================================
// Initialization object

class Cyg_Fileio_Init_Class
{
public:    
    Cyg_Fileio_Init_Class();
};

static Cyg_Fileio_Init_Class fileio_initializer CYGBLD_ATTRIB_INIT_PRI(CYG_INIT_IO_FS);

Cyg_Fileio_Init_Class::Cyg_Fileio_Init_Class()
{
    cyg_fd_init();

    cyg_mtab_init();

    chdir("/");
}

//==========================================================================
// Mount table initializer

static void cyg_mtab_init()
{
    cyg_mtab_entry *m;
    
    for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )
    {
        const char *fsname = m->fsname;
        cyg_fstab_entry *f;

        // Ignore empty entries
        if( m->name == NULL )
            continue;
        
        // stop if there are more than the configured maximum
        if( m-&cyg_mtab[0] >= CYGNUM_FILEIO_MTAB_MAX )
            break;
        
        for( f = &cyg_fstab[0]; f != &cyg_fstab_end; f++ )
        {
            // stop if there are more than the configured maximum
            if( f-&cyg_fstab[0] >= CYGNUM_FILEIO_FSTAB_MAX )
                break;
            
            if( strcmp( fsname, f->name) == 0 )
            {
                // We have a match.

                if( f->mount( f, m ) == 0 )
                {
                    m->valid    = true;
                    m->fs       = f;
                    // m->root installed by fs.
                }
                else
                {
                    m->valid = false;
                }
                
                break;
            }
        }
    }
}

//==========================================================================
// Mount table matching

// -------------------------------------------------------------------------
// matchlen() compares two strings and returns the number of bytes by which
// they match.

static int matchlen( const char *s1, const char *s2 )
{
    int len = 0;
    while( s1[len] == s2[len] && s1[len] && s2[len] ) len++;

    // Return length only if s2 is an initial substring of s1,
    // and it terminates in s1 at end-of-string or a '/'.

    // Special case for s2 == "/"
    if( len == 1 && s2[0] == '/' && s2[1] == 0 )
        return len;
    
    if( (s2[len] == 0) && (s1[len] == 0 || s1[len] == '/'))
         return len;
    else return 0;
}

// -------------------------------------------------------------------------
// Simple strlen implementation

static int my_strlen(const char *c)
{
    int l = 0;
    while (*c++) l++;
    return l;
}

// -------------------------------------------------------------------------
// Search the mtab for the entry that matches the longest substring of
// **name. 

__externC int cyg_mtab_lookup( cyg_dir *dir, const char **name, cyg_mtab_entry **mte)
{
    cyg_mtab_entry *m, *best = NULL;
    int best_len = 0;

    // Unrooted file names start from current dir
    if( **name != '/' ) {
        int cwd_len;
        if (*mte == (cyg_mtab_entry *)NULL) {
            // No known current directory
            return -1;
        }

        best = *mte;
	cwd_len = my_strlen((*mte)->name);

        // current dir is not the correct mte if the relative path crosses
        // mount points -  search for best matching mount point
        for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )
	{
            if( m->name != NULL && m->valid )
            {
                int len = matchlen(m->name, (*mte)->name);
                // mount point under cwd?
                if (len == cwd_len)
                {
                    if (m->name[len] == '/')
                        len++;

                    len = matchlen(*name, &m->name[len]);