ftw.c

Axis 221 camera embedded programing interface

/* File tree walker functions.
   Copyright (C) 1996-2001, 2002, 2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <[e-mail]>, 1996.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#define _GNU_SOURCE
#include <features.h>


#if defined (__UCLIBC_HAS_LFS__) && defined L_ftw64
#define L_ftw

/* If Large file support is enabled, transparently remap
 * things to use the 64-bit interfaces */
#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS != 64 
#undef _FILE_OFFSET_BITS
#define	_FILE_OFFSET_BITS   64
#endif
#ifndef __USE_LARGEFILE64
# define __USE_LARGEFILE64  1
#endif
#ifndef __USE_FILE_OFFSET64
# define __USE_FILE_OFFSET64  1
#endif

#define FTW_NAME ftw64
#define NFTW_NAME nftw64
#define INO_T ino64_t
#define STAT stat64
#define LSTAT lstat64
#define XSTAT stat64
#define FTW_FUNC_T __ftw64_func_t
#define NFTW_FUNC_T __nftw64_func_t
#else
#define FTW_NAME ftw
#define NFTW_NAME nftw
#define INO_T ino_t
#define STAT stat
#define LSTAT lstat
#define XSTAT stat
#define FTW_FUNC_T __ftw_func_t
#define NFTW_FUNC_T __nftw_func_t
#endif

#ifdef L_ftw

#include <alloca.h>
#include <errno.h>
#include <ftw.h>
#include <limits.h>
#include <search.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <assert.h>
#include <dirent.h>

/* We define PATH_MAX if the system does not provide a definition.
   This does not artificially limit any operation.  PATH_MAX is simply
   used as a guesstimate for the expected maximal path length.
   Buffers will be enlarged if necessary.  */
#ifndef PATH_MAX
# define PATH_MAX 1024
#endif

struct dir_data
{
    DIR *stream;
    char *content;
};

struct known_object
{
    dev_t dev;
    INO_T ino;
};

struct ftw_data
{
    /* Array with pointers to open directory streams.  */
    struct dir_data **dirstreams;
    size_t actdir;
    size_t maxdir;

    /* Buffer containing name of currently processed object.  */
    char *dirbuf;
    size_t dirbufsize;

    /* Passed as fourth argument to `nftw' callback.  The `base' member
       tracks the content of the `dirbuf'.  */
    struct FTW ftw;

    /* Flags passed to `nftw' function.  0 for `ftw'.  */
    int flags;

    /* Conversion array for flag values.  It is the identity mapping for
       `nftw' calls, otherwise it maps the values to those known by
       `ftw'.  */
    const int *cvt_arr;

    /* Callback function.  We always use the `nftw' form.  */
    NFTW_FUNC_T func;

    /* Device of starting point.  Needed for FTW_MOUNT.  */
    dev_t dev;

    /* Data structure for keeping fingerprints of already processed
       object.  This is needed when not using FTW_PHYS.  */
    void *known_objects;
};


/* Internally we use the FTW_* constants used for `nftw'.  When invoked
   as `ftw', map each flag to the subset of values used by `ftw'.  */
static const int nftw_arr[] =
{
    FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_SL, FTW_DP, FTW_SLN
};

static const int ftw_arr[] =
{
    FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_F, FTW_D, FTW_NS
};

/* Forward declarations of local functions.  */
static int ftw_dir (struct ftw_data *data, struct STAT *st) internal_function;


static int
object_compare (const void *p1, const void *p2)
{
    /* We don't need a sophisticated and useful comparison.  We are only
       interested in equality.  However, we must be careful not to
       accidentally compare `holes' in the structure.  */
    const struct known_object *kp1 = p1, *kp2 = p2;
    int cmp1;
    cmp1 = (kp1->ino > kp2->ino) - (kp1->ino < kp2->ino);
    if (cmp1 != 0)
	return cmp1;
    return (kp1->dev > kp2->dev) - (kp1->dev < kp2->dev);
}


static inline int
add_object (struct ftw_data *data, struct STAT *st)
{
    struct known_object *newp = malloc (sizeof (struct known_object));
    if (newp == NULL)
	return -1;
    newp->dev = st->st_dev;
    newp->ino = st->st_ino;
    return tsearch (newp, &data->known_objects, object_compare) ? 0 : -1;
}


static inline int
find_object (struct ftw_data *data, struct STAT *st)
{
    struct known_object obj;
    obj.dev = st->st_dev;
    obj.ino = st->st_ino;
    return tfind (&obj, &data->known_objects, object_compare) != NULL;
}


static inline int
__attribute ((always_inline))
open_dir_stream (struct ftw_data *data, struct dir_data *dirp)
{
    int result = 0;

    if (data->dirstreams[data->actdir] != NULL)
    {
	/* Oh, oh.  We must close this stream.  Get all remaining
	   entries and store them as a list in the `content' member of
	   the `struct dir_data' variable.  */
	size_t bufsize = 1024;
	char *buf = malloc (bufsize);

	if (buf == NULL)
	    result = -1;
	else
	{
	    DIR *st = data->dirstreams[data->actdir]->stream;
	    struct dirent *d;
	    size_t actsize = 0;

	    while ((d = readdir (st)) != NULL)
	    {
		size_t this_len = _D_EXACT_NAMLEN (d);
		if (actsize + this_len + 2 >= bufsize)
		{
		    char *newp;
		    bufsize += MAX (1024, 2 * this_len);
		    newp = (char *) realloc (buf, bufsize);
		    if (newp == NULL)
		    {
			/* No more memory.  */
			int save_err = errno;
			free (buf);
			__set_errno (save_err);
			result = -1;
			break;
		    }
		    buf = newp;
		}

		*((char *) mempcpy (buf + actsize, d->d_name, this_len))
		    = '\0';
		actsize += this_len + 1;
	    }

	    /* Terminate the list with an additional NUL byte.  */
	    buf[actsize++] = '\0';

	    /* Shrink the buffer to what we actually need.  */
	    data->dirstreams[data->actdir]->content = realloc (buf, actsize);
	    if (data->dirstreams[data->actdir]->content == NULL)
	    {
		int save_err = errno;
		free (buf);
		__set_errno (save_err);
		result = -1;
	    }
	    else
	    {
		closedir (st);
		data->dirstreams[data->actdir]->stream = NULL;
		data->dirstreams[data->actdir] = NULL;
	    }
	}
    }

    /* Open the new stream.  */
    if (result == 0)
    {
	const char *name = ((data->flags & FTW_CHDIR)
		? data->dirbuf + data->ftw.base: data->dirbuf);
	assert (data->dirstreams[data->actdir] == NULL);

	dirp->stream = opendir (name);
	if (dirp->stream == NULL)
	    result = -1;
	else
	{
	    dirp->content = NULL;
	    data->dirstreams[data->actdir] = dirp;

	    if (++data->actdir == data->maxdir)
		data->actdir = 0;
	}
    }

    return result;
}


static int
internal_function
process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, size_t namlen)
{
    struct STAT st;
    int result = 0;
    int flag = 0;
    size_t new_buflen;

    if (name[0] == '.' && (name[1] == '\0'
		|| (name[1] == '.' && name[2] == '\0')))
	/* Don't process the "." and ".." entries.  */
	return 0;

    new_buflen = data->ftw.base + namlen + 2;
    if (data->dirbufsize < new_buflen)
    {
	/* Enlarge the buffer.  */
	char *newp;

	data->dirbufsize = 2 * new_buflen;
	newp = (char *) realloc (data->dirbuf, data->dirbufsize);
	if (newp == NULL)
	    return -1;
	data->dirbuf = newp;
    }

    *((char *) mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0';

    if ((data->flags & FTW_CHDIR) == 0)
	name = data->dirbuf;

    if (((data->flags & FTW_PHYS)
		? LSTAT (name, &st)
		: XSTAT (name, &st)) < 0)
    {
	if (errno != EACCES && errno != ENOENT)
	    result = -1;
	else if (!(data->flags & FTW_PHYS)
		&& LSTAT (name, &st) == 0
		&& S_ISLNK (st.st_mode))
	    flag = FTW_SLN;
	else
	    flag = FTW_NS;
    }
    else
    {
	if (S_ISDIR (st.st_mode))
	    flag = FTW_D;
	else if (S_ISLNK (st.st_mode))
	    flag = FTW_SL;