fchroot(2) [opensolaris man page]

chroot(2)							   System Calls 							 chroot(2)

NAME

       chroot, fchroot - change root directory

SYNOPSIS

       #include <unistd.h>

       int chroot(const char *path);

       int fchroot(int fildes);

DESCRIPTION

       The  chroot()  and  fchroot() functions cause a directory to become the root directory, the starting point for path searches for path names
       beginning with / (slash). The user's working directory is unaffected by the chroot() and fchroot() functions.

       The path argument points to a path name naming a directory. The fildes argument to fchroot() is the open file descriptor of  the  directory
       which is to become the root.

       The privilege {PRIV_PROC_CHROOT} must be asserted in the effective set of the process to change the root directory. While it is always pos-
       sible to change to the system root using the fchroot() function, it is not guaranteed to succeed in any other case, even if fildes is valid
       in all respects.

       The  ".." entry in the root directory is interpreted to mean the root directory itself. Therefore, ".." cannot be used to access files out-
       side the subtree rooted at the root directory. Instead, fchroot() can be used to reset the root to a directory that was opened  before  the
       root directory was changed.

RETURN VALUES

       Upon  successful  completion,  0 is returned. Otherwise, -1 is returned, the root directory remains unchanged, and errno is set to indicate
       the error.

ERRORS

       The chroot() function will fail if:

       EACCES	       Search permission is denied for a component of the path prefix of dirname, or search permission is denied for the directory
		       referred to by dirname.

       EBADF	       The descriptor is not valid.

       EFAULT	       The path argument points to an illegal address.

       EINVAL	       The  fchroot()  function  attempted  to	change to a directory the is not the system root and external circumstances do not
		       allow this.

       EINTR	       A signal was caught during the execution of the chroot() function.

       EIO	       An I/O error occurred while reading from or writing to the file system.

       ELOOP	       Too many symbolic links were encountered in translating path.

       ENAMETOOLONG    The length of the path argument exceeds PATH_MAX, or the length of a path component exceeds NAME_MAX while  _POSIX_NO_TRUNC
		       is in effect.

       ENOENT	       The named directory does not exist or is a null pathname.

       ENOLINK	       The path argument points to a remote machine and the link to that machine is no longer active.

       ENOTDIR	       Any component of the path name is not a directory.

       EPERM	       The {PRIV_PROC_CHROOT} privilege is not asserted in the effective set of the calling process.

SEE ALSO

       chroot(1M), chdir(2), privileges(5)

WARNINGS

       The only use of fchroot() that is appropriate is to change back to the system root.

SunOS 5.11							    20 Jan 2003 							 chroot(2)

Check Out this Related Man Page

CHROOT(2)						      BSD System Calls Manual							 CHROOT(2)

NAME

     chroot -- change root directory

SYNOPSIS

     #include <unistd.h>

     int
     chroot(const char *dirname);

DESCRIPTION

     Dirname is the address of the pathname of a directory, terminated by an ASCII NUL.  Chroot() causes dirname to become the root directory,
     that is, the starting point for path searches of pathnames beginning with '/'.

     In order for a directory to become the root directory a process must have execute (search) access for that directory.

     If the program is not currently running with an altered root directory, it should be noted that chroot() has no effect on the process's cur-
     rent directory.

     If the program is already running with an altered root directory, the process's current directory is changed to the same new root directory.
     This prevents the current directory from being further up the directory tree than the altered root directory.

     This call is restricted to the super-user.

RETURN VALUES

     Upon successful completion, a value of 0 is returned.  Otherwise, a value of -1 is returned and errno is set to indicate an error.

ERRORS

     Chroot() will fail and the root directory will be unchanged if:

     [ENOTDIR]		A component of the path name is not a directory.

     [ENAMETOOLONG]	A component of a pathname exceeded {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters.

     [ENOENT]		The named directory does not exist.

     [EACCES]		Search permission is denied for any component of the path name.

     [ELOOP]		Too many symbolic links were encountered in translating the pathname.

     [EFAULT]		Path points outside the process's allocated address space.

     [EIO]		An I/O error occurred while reading from or writing to the file system.

SEE ALSO

     chdir(2)

WARNINGS

     There are ways for a root process to escape from the chroot jail.

HISTORY

     The chroot() function call appeared in 4.2BSD.

4.2 Berkeley Distribution					   June 4, 1993 					 4.2 Berkeley Distribution

Linux and UNIX Man Pages

fchroot(2) [opensolaris man page]

Check Out this Related Man Page