4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2017, Lawrence Livermore National Security, LLC.
28 #include <sys/types.h>
30 #include <sys/systeminfo.h>
40 * Allow the hostid to be subverted for testing.
42 env = getenv("ZFS_HOSTID");
44 hostid = strtoull(env, NULL, 0);
45 return (hostid & HOSTID_MASK);
48 f = fopen("/sys/module/spl/parameters/spl_hostid", "r");
52 if (fscanf(f, "%lu", &hostid) != 1)
57 return (hostid & HOSTID_MASK);
61 get_system_hostid(void)
63 unsigned long system_hostid = get_spl_hostid();
65 * We do not use the library call gethostid() because
66 * it generates a hostid value that the kernel is
67 * unaware of, if the spl_hostid module parameter has not
68 * been set and there is no system hostid file (e.g.
69 * /etc/hostid). The kernel and userspace must agree.
70 * See comments above hostid_read() in the SPL.
72 if (system_hostid == 0) {
75 int hostid_size = 4; /* 4 bytes regardless of arch */
77 fd = open("/etc/hostid", O_RDONLY);
79 rc = read(fd, &hostid, hostid_size);
81 system_hostid = (hostid & HOSTID_MASK);
85 return (system_hostid);