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/* File tree walker functions.

   Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@cygnus.com>, 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.  */

/* Modified for newlib by Jeff Johnston, July 26, 2002 */

#define _GNU_SOURCE 1

#include <dirent.h>

#include <errno.h>

#include <ftw.h>

#include <search.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/param.h>

#include <sys/stat.h>

extern struct dirent64 *__readdir64 (DIR *);

/* #define NDEBUG 1 */

#include <assert.h>

/* Support for the LFS API version.  */

#ifndef FTW_NAME

# define FTW_NAME ftw

# define NFTW_NAME nftw

# define INO_T ino_t

# define STAT stat

# define LXSTAT lstat

# define XSTAT stat

# define FTW_FUNC_T __ftw_func_t

# define NFTW_FUNC_T __nftw_func_t

#endif

#define dirfd(x) ((x)->dd_fd)

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 know 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 the

   process called `ftw' we must reduce the flag to the known flags

   for `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);

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->dev > kp2->dev) - (kp1->dev < kp2->dev);

  if (cmp1 != 0)

    return cmp1;

  return (kp1->ino > kp2->ino) - (kp1->ino < kp2->ino);

}

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 = { dev: st->st_dev, ino: st->st_ino };

  return tfind (&obj, &data->known_objects, object_compare) != NULL;

}

static inline int

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 dirent64 *d;

          size_t actsize = 0;

          while ((d = __readdir64 (st)) != NULL)

            {

              size_t this_len = strlen (d->d_name);

              if (actsize + this_len + 2 >= bufsize)

                {

                  char *newp;

                  bufsize += MAX (1024, 2 * this_len);

                  newp = 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)

    {

      assert (data->dirstreams[data->actdir] == NULL);

      dirp->stream = opendir (data->dirbuf);

      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 inline int

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;

  if (name[0] == '.' && (name[1] == '\0'

                         || (name[1] == '.' && name[2] == '\0')))

    /* Don't process the "." and ".." entries.  */

    return 0;

  if (data->dirbufsize < data->ftw.base + namlen + 2)

    {

      /* Enlarge the buffer.  */

      char *newp;

      data->dirbufsize *= 2;

      newp = 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_PHYS)

       ? LXSTAT (data->dirbuf, &st)

       : XSTAT (data->dirbuf, &st)) < 0)

    {

      if (errno != EACCES && errno != ENOENT)

        result = -1;

      else if (!(data->flags & FTW_PHYS)

               && LXSTAT (data->dirbuf, &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;

      else

        flag = FTW_F;

    }

  if (result == 0

      && (flag == FTW_NS

          || !(data->flags & FTW_MOUNT) || st.st_dev == data->dev))

    {

      if (flag == FTW_D)

        {

          if ((data->flags & FTW_PHYS)

              || (!find_object (data, &st)

                  /* Remember the object.  */

                  && (result = add_object (data, &st)) == 0))

            {

              result = ftw_dir (data, &st);

              if (result == 0 && (data->flags & FTW_CHDIR))

                {

                  /* Change back to current directory.  */

                  int done = 0;

                  if (dir->stream != NULL)

                    if (fchdir (dirfd (dir->stream)) == 0)

                      done = 1;

                  if (!done)

                    {

                      if (data->ftw.base == 1)

                        {

                          if (chdir ("/") < 0)

                            result = -1;

                        }

                      else

                        {

                          /* Please note that we overwrite a slash.  */

                          data->dirbuf[data->ftw.base - 1] = '\0';

                          if (chdir (data->dirbuf) < 0)

                            result = -1;

                          data->dirbuf[data->ftw.base - 1] = '/';

                        }

                    }

                }

            }

        }

      else

        result = (*data->func) (data->dirbuf, &st, data->cvt_arr[flag],

                                &data->ftw);

    }

  return result;

}

static int

ftw_dir (struct ftw_data *data, struct STAT *st)

{

  struct dir_data dir;

  struct dirent64 *d;

  int previous_base = data->ftw.base;

  int result;

  char *startp;

  /* Open the stream for this directory.  This might require that

     another stream has to be closed.  */

  result = open_dir_stream (data, &dir);

  if (result != 0)

    {

      if (errno == EACCES)

        /* We cannot read the directory.  Signal this with a special flag.  */

        result = (*data->func) (data->dirbuf, st, FTW_DNR, &data->ftw);

      return result;

    }

  /* First, report the directory (if not depth-first).  */

  if (!(data->flags & FTW_DEPTH))

    {

      result = (*data->func) (data->dirbuf, st, FTW_D, &data->ftw);

      if (result != 0)

        return result;

    }

  /* If necessary, change to this directory.  */

  if (data->flags & FTW_CHDIR)

    {

      if (fchdir (dirfd (dir.stream)) < 0)

        {

          if (errno == ENOSYS)

            {

              if (chdir (data->dirbuf) < 0)

                result = -1;

            }

          else

            result = -1;

        }

      if (result != 0)

        {

          int save_err = errno;

          closedir (dir.stream);

          __set_errno (save_err);

          if (data->actdir-- == 0)

            data->actdir = data->maxdir - 1;

          data->dirstreams[data->actdir] = NULL;

          return result;

        }

    }

  /* Next, update the `struct FTW' information.  */

  ++data->ftw.level;

  startp = strchr (data->dirbuf, '\0');

  /* There always must be a directory name.  */

  assert (startp != data->dirbuf);

  if (startp[-1] != '/')

    *startp++ = '/';

  data->ftw.base = startp - data->dirbuf;

  while (dir.stream != NULL && (d = __readdir64 (dir.stream)) != NULL)

    {

      result = process_entry (data, &dir, d->d_name, strlen (d->d_name));

      if (result != 0)

        break;

    }

  if (dir.stream != NULL)

    {

      /* The stream is still open.  I.e., we did not need more

         descriptors.  Simply close the stream now.  */

      int save_err = errno;

      assert (dir.content == NULL);

      closedir (dir.stream);

      __set_errno (save_err);

      if (data->actdir-- == 0)

        data->actdir = data->maxdir - 1;

      data->dirstreams[data->actdir] = NULL;

    }

  else

    {

      int save_err;

      char *runp = dir.content;

      while (result == 0 && *runp != '\0')

        {

          char *endp = strchr (runp, '\0');

          result = process_entry (data, &dir, runp, endp - runp);

          runp = endp + 1;

        }

      save_err = errno;

      free (dir.content);

      __set_errno (save_err);

    }

  /* Prepare the return, revert the `struct FTW' information.  */

  data->dirbuf[data->ftw.base - 1] = '\0';

  --data->ftw.level;

  data->ftw.base = previous_base;

  /* Finally, if we process depth-first report the directory.  */

  if (result == 0 && (data->flags & FTW_DEPTH))

    result = (*data->func) (data->dirbuf, st, FTW_DP, &data->ftw);

  return result;

}

static int

ftw_startup (const char *dir, int is_nftw, void *func, int descriptors,

             int flags)

{

  struct ftw_data data;

  struct STAT st;

  int result = 0;

  int save_err;

  int len;

  char *cwd = NULL;

  char *cp;

  /* First make sure the parameters are reasonable.  */

  if (dir[0] == '\0')

    {

      __set_errno (ENOENT);

      return -1;

    }

  if (access (dir, R_OK) != 0)

    return -1;

  data.maxdir = descriptors < 1 ? 1 : descriptors;

  data.actdir = 0;

  data.dirstreams = (struct dir_data **) alloca (data.maxdir

                                                 * sizeof (struct dir_data *));

  memset (data.dirstreams, '\0', data.maxdir * sizeof (struct dir_data *));

#ifdef PATH_MAX

  data.dirbufsize = MAX (2 * strlen (dir), PATH_MAX);

#else

  data.dirbufsize = 2 * strlen (dir);

#endif

  data.dirbuf = (char *) malloc (data.dirbufsize);

  if (data.dirbuf == NULL)

    return -1;

  len = strlen (dir);

  cp = mempcpy (data.dirbuf, dir, len);

  /* Strip trailing slashes.  */

  while (cp > data.dirbuf + 1 && cp[-1] == '/')

    --cp;

  *cp = '\0';

  data.ftw.level = 0;

  /* Find basename.  */

  while (cp > data.dirbuf && cp[-1] != '/')

    --cp;

  data.ftw.base = cp - data.dirbuf;

  data.flags = flags;

  /* This assignment might seem to be strange but it is what we want.

     The trick is that the first three arguments to the `ftw' and

     `nftw' callback functions are equal.  Therefore we can call in

     every case the callback using the format of the `nftw' version

     and get the correct result since the stack layout for a function

     call in C allows this.  */

  data.func = (NFTW_FUNC_T) func;

  /* Since we internally use the complete set of FTW_* values we need

     to reduce the value range before calling a `ftw' callback.  */

  data.cvt_arr = is_nftw ? nftw_arr : ftw_arr;

  /* No object known so far.  */

  data.known_objects = NULL;

  /* Now go to the directory containing the initial file/directory.  */

  if ((flags & FTW_CHDIR) && data.ftw.base > 0)

    {

      /* GNU extension ahead.  */

      cwd =  getcwd (NULL, 0);

      if (cwd == NULL)

        result = -1;

      else

        {

          /* Change to the directory the file is in.  In data.dirbuf

             we have a writable copy of the file name.  Just NUL

             terminate it for now and change the directory.  */

          if (data.ftw.base == 1)

            /* I.e., the file is in the root directory.  */

            result = chdir ("/");

          else

            {

              char ch = data.dirbuf[data.ftw.base - 1];

              data.dirbuf[data.ftw.base - 1] = '\0';

              result = chdir (data.dirbuf);

              data.dirbuf[data.ftw.base - 1] = ch;

            }

        }

    }

  /* Get stat info for start directory.  */

  if (result == 0)

    {

      if (((flags & FTW_PHYS)

           ? LXSTAT (data.dirbuf, &st)

           : XSTAT (data.dirbuf, &st)) < 0)

        {

          if (errno == EACCES)

            result = (*data.func) (data.dirbuf, &st, FTW_NS, &data.ftw);

          else if (!(flags & FTW_PHYS)

                   && errno == ENOENT

                   && LXSTAT (dir, &st) == 0

                   && S_ISLNK (st.st_mode))

            result = (*data.func) (data.dirbuf, &st, data.cvt_arr[FTW_SLN],

                                   &data.ftw);

          else

            /* No need to call the callback since we cannot say anything

               about the object.  */

            result = -1;

        }

      else

        {

          if (S_ISDIR (st.st_mode))

            {

              /* Remember the device of the initial directory in case

                 FTW_MOUNT is given.  */

              data.dev = st.st_dev;

              /* We know this directory now.  */

              if (!(flags & FTW_PHYS))

                result = add_object (&data, &st);

              if (result == 0)

                result = ftw_dir (&data, &st);

            }

          else

            {

              int flag = S_ISLNK (st.st_mode) ? FTW_SL : FTW_F;

              result = (*data.func) (data.dirbuf, &st, data.cvt_arr[flag],

                                     &data.ftw);

            }

        }

    }

  /* Return to the start directory (if necessary).  */

  if (cwd != NULL)

    {

      int save_err = errno;

      chdir (cwd);

      free (cwd);

      __set_errno (save_err);

    }

  /* Free all memory.  */

  save_err = errno;

  tdestroy (data.known_objects, free);

  free (data.dirbuf);

  __set_errno (save_err);

  return result;

}

/* Entry points.  */

int

FTW_NAME (path, func, descriptors)

     const char *path;

     FTW_FUNC_T func;

     int descriptors;

{

  return ftw_startup (path, 0, func, descriptors, 0);

}

int

NFTW_NAME (path, func, descriptors, flags)

     const char *path;

     NFTW_FUNC_T func;

     int descriptors;

     int flags;

{

  return ftw_startup (path, 1, func, descriptors, flags);

}