Ticket #62994: deepdir.c

#define HAVE_UNISTD_H 11
#define HAVE_SYS_PARAM_H 1
#include <errno.h>
#include <stdlib.h>
#if HAVE_UNISTD_H
# include <unistd.h>
#else
# include <direct.h>
#endif
#include <string.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>


/* Arrange to define PATH_MAX, like "pathmax.h" does. */
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <limits.h>
#if defined HAVE_SYS_PARAM_H && !defined PATH_MAX && !defined MAXPATHLEN
# include <sys/param.h>
#endif
#if !defined PATH_MAX && defined MAXPATHLEN
# define PATH_MAX MAXPATHLEN
#endif
#ifdef __hpux
# undef PATH_MAX
# define PATH_MAX 1024
#endif
#if defined _WIN32 && ! defined __CYGWIN__
# undef PATH_MAX
# define PATH_MAX 260
#endif


#ifndef AT_FDCWD
# define AT_FDCWD 0
#endif
#ifdef ENAMETOOLONG
# define is_ENAMETOOLONG(x) ((x) == ENAMETOOLONG)
#else
# define is_ENAMETOOLONG(x) 0
#endif

/* Use the getcwd function, not any macro.  */
#undef getcwd



#if defined _WIN32 && !defined __CYGWIN__
#define access    _access
#define chdir     _chdir
#define chmod     _chmod
#define close     _close
#define creat     _creat
#define dup       _dup
#define dup2      _dup2
#define ecvt      _ecvt
#define execl     _execl
#define execle    _execle
#define execlp    _execlp
#define execv     _execv
#define execve    _execve
#define execvp    _execvp
#define execvpe   _execvpe
#define fcloseall _fcloseall
#define fcvt      _fcvt
#define fdopen    _fdopen
#define fileno    _fileno
#define gcvt      _gcvt
#define getcwd    _getcwd
#define getpid    _getpid
#define getw      _getw
#define isatty    _isatty
#define j0        _j0
#define j1        _j1
#define jn        _jn
#define lfind     _lfind
#define lsearch   _lsearch
#define lseek     _lseek
#define memccpy   _memccpy
#define mkdir     _mkdir
#define mktemp    _mktemp
#define open      _open
#define putenv    _putenv
#define putw      _putw
#define read      _read
#define rmdir     _rmdir
#define strdup    _strdup
#define swab      _swab
#define tempnam   _tempnam
#define tzset     _tzset
#define umask     _umask
#define unlink    _unlink
#define utime     _utime
#define wcsdup    _wcsdup
#define write     _write
#define y0        _y0
#define y1        _y1
#define yn        _yn
#endif


#ifndef S_IRWXU
# define S_IRWXU 0700
#endif

/* The length of this name must be 8.  */
#define DIR_NAME "confdir3"
#define DIR_NAME_LEN 8
#define DIR_NAME_SIZE (DIR_NAME_LEN + 1)

/* The length of "../".  */
#define DOTDOTSLASH_LEN 3

/* Leftover bytes in the buffer, to work around library or OS bugs.  */
#define BUF_SLOP 20

int
main ()
{
#ifndef PATH_MAX
  /* The Hurd doesn't define this, so getcwd can't exhibit the bug --
     at least not on a local file system.  And if we were to start worrying
     about remote file systems, we'd have to enable the wrapper function
     all of the time, just to be safe.  That's not worth the cost.  */
  exit (0);
#elif ((INT_MAX / (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) \
        - DIR_NAME_SIZE - BUF_SLOP) \
       <= PATH_MAX)
  /* FIXME: Assuming there's a system for which this is true,
     this should be done in a compile test.  */
  exit (0);
#else
  char buf[PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1)
           + DIR_NAME_SIZE + BUF_SLOP];
  char *cwd = getcwd (buf, PATH_MAX);
  size_t initial_cwd_len;
  size_t cwd_len;
  int fail = 0;
  size_t n_chdirs = 0;

  if (cwd == NULL)
    exit (10);

  cwd_len = initial_cwd_len = strlen (cwd);

  while (1)
    {
      size_t dotdot_max = PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN);
      char *c = NULL;

      cwd_len += DIR_NAME_SIZE;
      /* If mkdir or chdir fails, it could be that this system cannot create
         any file with an absolute name longer than PATH_MAX, such as cygwin.
         If so, leave fail as 0, because the current working directory can't
         be too long for getcwd if it can't even be created.  On Linux with
         the 9p file system, mkdir fails with error EINVAL when cwd_len gets
         too long; ignore this failure because the getcwd() system call
         produces good results whereas the gnulib substitute calls getdents64
         which fails with error EPROTO.
         For other errors, be pessimistic and consider that as a failure,
         too.  */
      if (mkdir (DIR_NAME, S_IRWXU) < 0 || chdir (DIR_NAME) < 0)
        {
          if (! (errno == ERANGE || is_ENAMETOOLONG (errno)))
            #ifdef __linux__
            if (! (errno == EINVAL))
            #endif
              fail = 20;
          break;
        }

      if (PATH_MAX <= cwd_len && cwd_len < PATH_MAX + DIR_NAME_SIZE)
        {
          struct stat sb;

          c = getcwd (buf, PATH_MAX);
          if (!c && errno == ENOENT)
            {
              fail = 11;
              break;
            }
          if (c)
            {
              fail = 31;
              break;
            }
          if (! (errno == ERANGE || is_ENAMETOOLONG (errno)))
            {
              fail = 21;
              break;
            }

          /* Our replacement needs to be able to stat() long ../../paths,
             so generate a path larger than PATH_MAX to check,
             avoiding the replacement if we can't stat().  */
          c = getcwd (buf, cwd_len + 1);
          if (c && !AT_FDCWD && stat (c, &sb) != 0 && is_ENAMETOOLONG (errno))
            {
              fail = 32;
              break;
            }
        }

      if (dotdot_max <= cwd_len - initial_cwd_len)
        {
          if (dotdot_max + DIR_NAME_SIZE < cwd_len - initial_cwd_len)
            break;
          c = getcwd (buf, cwd_len + 1);
          if (!c)
            {
              if (! (errno == ERANGE || errno == ENOENT
                     || is_ENAMETOOLONG (errno)))
                {
                  fail = 22;
                  break;
                }
              if (AT_FDCWD || errno == ERANGE || errno == ENOENT)
                {
                  fail = 12;
                  break;
                }
            }
        }

      if (c && strlen (c) != cwd_len)
        {
          fail = 23;
          break;
        }
      ++n_chdirs;
    }

  /* Leaving behind such a deep directory is not polite.
     So clean up here, right away, even though the driving
     shell script would also clean up.  */
  {
    size_t i;

    /* Try rmdir first, in case the chdir failed.  */
    rmdir (DIR_NAME);
    for (i = 0; i <= n_chdirs; i++)
      {
        if (chdir ("..") < 0)
          break;
        if (rmdir (DIR_NAME) != 0)
          break;
      }
  }

  exit (fail);
#endif
}