cap_rights_get3

Usage

Library

Standard C Library (libc, -lc)

Overview

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

The cap_rights_get() function returns the value 0 if successful; 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.