zfs/lib/libspl/os/linux/zone.c

63 lines
1.6 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Ricardo Correia. All rights reserved.
* Use is subject to license terms.
*/
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <zone.h>
zoneid_t
getzoneid(void)
{
char path[PATH_MAX];
char buf[128] = { '\0' };
char *cp;
int c = snprintf(path, sizeof (path), "/proc/self/ns/user");
/* This API doesn't have any error checking... */
if (c < 0 || c >= sizeof (path))
return (0);
ssize_t r = readlink(path, buf, sizeof (buf) - 1);
if (r < 0)
return (0);
cp = strchr(buf, '[');
if (cp == NULL)
return (0);
cp++;
unsigned long n = strtoul(cp, NULL, 10);
if (n == ULONG_MAX && errno == ERANGE)
return (0);
zoneid_t z = (zoneid_t)n;
return (z);
}