@Override
public void setAcl(List<AclEntry> acl) throws IOException {
// permission check
checkAccess(file, false, true);
// open file (will fail if file is a link and not following links)
int fd = file.openForAttributeAccess(followLinks);
try {
// SECURITY: need to copy list as can change during processing
acl = new ArrayList<AclEntry>(acl);
int n = acl.size();
long address = unsafe.allocateMemory(SIZEOF_ACE_T * n);
try {
encode(acl, address);
facl(fd, ACE_SETACL, n, address);
} catch (UnixException x) {
if ((x.errno() == ENOSYS) || !isAclsEnabled(fd)) {
throw new FileSystemException(
file.getPathForExceptionMessage(),
null,
x.getMessage() + " (file system does not support NFSv4 ACLs)");
}
if (x.errno() == EINVAL && (n < 3))
throw new IOException("ACL must contain at least 3 entries");
x.rethrowAsIOException(file);
} finally {
unsafe.freeMemory(address);
}
} finally {
close(fd);
}
}
@Override
public List<AclEntry> getAcl() throws IOException {
// permission check
checkAccess(file, true, false);
// open file (will fail if file is a link and not following links)
int fd = file.openForAttributeAccess(followLinks);
try {
long address = unsafe.allocateMemory(SIZEOF_ACE_T * MAX_ACL_ENTRIES);
try {
// read ACL and decode it
int n = facl(fd, ACE_GETACL, MAX_ACL_ENTRIES, address);
assert n >= 0;
return decode(address, n);
} catch (UnixException x) {
if ((x.errno() == ENOSYS) || !isAclsEnabled(fd)) {
throw new FileSystemException(
file.getPathForExceptionMessage(),
null,
x.getMessage() + " (file system does not support NFSv4 ACLs)");
}
x.rethrowAsIOException(file);
return null; // keep compiler happy
} finally {
unsafe.freeMemory(address);
}
} finally {
close(fd);
}
}
/** Permission checks to access file */
private void checkAccess(UnixPath file, boolean checkRead, boolean checkWrite) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
if (checkRead) file.checkRead();
if (checkWrite) file.checkWrite();
sm.checkPermission(new RuntimePermission("accessUserInformation"));
}
}