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/*
* 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 http://www.opensolaris.org/os/licensing.
* 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 (c) 2017, Lawrence Livermore National Security, LLC.
*/
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/systeminfo.h>
static unsigned long
get_spl_hostid(void)
{
FILE *f;
unsigned long hostid;
char *env;
/*
* Allow the hostid to be subverted for testing.
*/
env = getenv("ZFS_HOSTID");
if (env)
return (strtoull(env, NULL, 0));
f = fopen("/proc/sys/kernel/spl/hostid", "re");
if (!f)
return (0);
if (fscanf(f, "%lx", &hostid) != 1)
hostid = 0;
fclose(f);
return (hostid);
}
unsigned long
get_system_hostid(void)
{
unsigned long hostid = get_spl_hostid();
/*
* We do not use gethostid(3) because it can return a bogus ID,
* depending on the libc and /etc/hostid presence,
* and the kernel and userspace must agree.
* See comments above hostid_read() in the SPL.
*/
if (hostid == 0) {
int fd = open("/etc/hostid", O_RDONLY | O_CLOEXEC);
if (fd >= 0) {
if (read(fd, &hostid, 4) < 0)
hostid = 0;
(void) close(fd);
}
}
return (hostid & HOSTID_MASK);
}
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