CAP_RIGHTS_GET(3)      FreeBSD Library Functions Manual      CAP_RIGHTS_GET(3)

NAME
     cap_rights_get - obtain capability rights

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/capsicum.h>

     int
     cap_rights_get(int fd, cap_rights_t *rights);

DESCRIPTION
     The cap_rights_get function allows to obtain current capability rights
     for the given descriptor.  The function will fill the rights argument
     with all capability rights if they were not limited or capability rights
     configured during the last successful call of cap_rights_limit(2) on the
     given descriptor.

     The rights argument can be inspected using cap_rights_init(3) family of
     functions.

     The complete list of the capability rights can be found in the rights(4)
     manual page.

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.

EXAMPLES
     The following example demonstrates how to limit file descriptor
     capability rights and how to obtain them.

     cap_rights_t setrights, getrights;
     int fd;

     memset(&setrights, 0, sizeof(setrights));
     memset(&getrights, 0, sizeof(getrights));

     fd = open("/tmp/foo", O_RDONLY);
     if (fd < 0)
             err(1, "open() failed");

     cap_rights_init(&setrights, CAP_FSTAT, CAP_READ);
     if (cap_rights_limit(fd, &setrights) < 0 && errno != ENOSYS)
             err(1, "cap_rights_limit() failed");

     if (cap_rights_get(fd, &getrights) < 0 && errno != ENOSYS)
             err(1, "cap_rights_get() failed");

     assert(memcmp(&setrights, &getrights, sizeof(setrights)) == 0);

ERRORS
     cap_rights_get() succeeds unless:

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

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

SEE ALSO
     cap_rights_limit(2), errno(2), open(2), assert(3), cap_rights_init(3),
     err(3), memcmp(3), memset(3), capsicum(4), rights(4)

HISTORY
     The cap_rights_get() function first appeared in FreeBSD 9.2.  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.

FreeBSD 13.1-RELEASE-p6           May 5, 2020          FreeBSD 13.1-RELEASE-p6