NAME

     cap_fcntls_limit, cap_fcntls_get — manage allowed fcntl commands

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/capsicum.h>

     int
     cap_fcntls_limit(int fd, uint32_t fcntlrights);

     int
     cap_fcntls_get(int fd, uint32_t *fcntlrightsp);

DESCRIPTION

     If a file descriptor is granted the CAP_FCNTL capability right, the list of allowed fcntl(2)
     commands can be selectively reduced (but never expanded) with the cap_fcntls_limit() system
     call.

     A bitmask of allowed fcntls commands for a given file descriptor can be obtained with the
     cap_fcntls_get() system call.

FLAGS

     The following flags may be specified in the fcntlrights argument or returned in the
     fcntlrightsp argument:

     CAP_FCNTL_GETFL   Permit F_GETFL command.

     CAP_FCNTL_SETFL   Permit F_SETFL command.

     CAP_FCNTL_GETOWN  Permit F_GETOWN command.

     CAP_FCNTL_SETOWN  Permit F_SETOWN command.

RETURN VALUES

     Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and
     the global variable errno is set to indicate the error.

ERRORS

     cap_fcntls_limit() succeeds unless:

     [EBADF]            The fd argument is not a valid descriptor.

     [EINVAL]           An invalid flag has been passed in fcntlrights.

     [ENOTCAPABLE]      fcntlrights would expand the list of allowed fcntl(2) commands.

     cap_fcntls_get() succeeds unless:

     [EBADF]            The fd argument is not a valid descriptor.

     [EFAULT]           The fcntlrightsp argument points at an invalid address.

SEE ALSO

     cap_ioctls_limit(2), cap_rights_limit(2), fcntl(2)

HISTORY

     The cap_fcntls_get() and cap_fcntls_limit() system calls first appeared in FreeBSD 8.3.
     Support for capabilities and capabilities mode was developed as part of the TrustedBSD
     Project.

AUTHORS

     This function was created by Pawel Jakub Dawidek <pawel@dawidek.net> under sponsorship of
     the FreeBSD Foundation.