1eda14cbcSMatt Macy /*
2eda14cbcSMatt Macy * CDDL HEADER START
3eda14cbcSMatt Macy *
4eda14cbcSMatt Macy * The contents of this file are subject to the terms of the
5eda14cbcSMatt Macy * Common Development and Distribution License (the "License").
6eda14cbcSMatt Macy * You may not use this file except in compliance with the License.
7eda14cbcSMatt Macy *
8eda14cbcSMatt Macy * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9271171e0SMartin Matuska * or https://opensource.org/licenses/CDDL-1.0.
10eda14cbcSMatt Macy * See the License for the specific language governing permissions
11eda14cbcSMatt Macy * and limitations under the License.
12eda14cbcSMatt Macy *
13eda14cbcSMatt Macy * When distributing Covered Code, include this CDDL HEADER in each
14eda14cbcSMatt Macy * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15eda14cbcSMatt Macy * If applicable, add the following below this CDDL HEADER, with the
16eda14cbcSMatt Macy * fields enclosed by brackets "[]" replaced with your own identifying
17eda14cbcSMatt Macy * information: Portions Copyright [yyyy] [name of copyright owner]
18eda14cbcSMatt Macy *
19eda14cbcSMatt Macy * CDDL HEADER END
20eda14cbcSMatt Macy */
21eda14cbcSMatt Macy /*
22eda14cbcSMatt Macy * Copyright (c) 2017, Lawrence Livermore National Security, LLC.
23eda14cbcSMatt Macy */
24eda14cbcSMatt Macy
25eda14cbcSMatt Macy #include <fcntl.h>
26eda14cbcSMatt Macy #include <stdlib.h>
27eda14cbcSMatt Macy #include <stdio.h>
28eda14cbcSMatt Macy #include <sys/types.h>
29eda14cbcSMatt Macy #include <sys/stat.h>
30eda14cbcSMatt Macy #include <sys/systeminfo.h>
31eda14cbcSMatt Macy
32eda14cbcSMatt Macy static unsigned long
get_spl_hostid(void)33eda14cbcSMatt Macy get_spl_hostid(void)
34eda14cbcSMatt Macy {
35eda14cbcSMatt Macy FILE *f;
36eda14cbcSMatt Macy unsigned long hostid;
37eda14cbcSMatt Macy char *env;
38eda14cbcSMatt Macy
39eda14cbcSMatt Macy /*
40eda14cbcSMatt Macy * Allow the hostid to be subverted for testing.
41eda14cbcSMatt Macy */
42eda14cbcSMatt Macy env = getenv("ZFS_HOSTID");
4316038816SMartin Matuska if (env)
4416038816SMartin Matuska return (strtoull(env, NULL, 0));
45eda14cbcSMatt Macy
4616038816SMartin Matuska f = fopen("/proc/sys/kernel/spl/hostid", "re");
47eda14cbcSMatt Macy if (!f)
48eda14cbcSMatt Macy return (0);
49eda14cbcSMatt Macy
5016038816SMartin Matuska if (fscanf(f, "%lx", &hostid) != 1)
51eda14cbcSMatt Macy hostid = 0;
52eda14cbcSMatt Macy
53eda14cbcSMatt Macy fclose(f);
54eda14cbcSMatt Macy
5516038816SMartin Matuska return (hostid);
56eda14cbcSMatt Macy }
57eda14cbcSMatt Macy
58eda14cbcSMatt Macy unsigned long
get_system_hostid(void)59eda14cbcSMatt Macy get_system_hostid(void)
60eda14cbcSMatt Macy {
6116038816SMartin Matuska unsigned long hostid = get_spl_hostid();
62*dbd5678dSMartin Matuska uint32_t system_hostid;
6316038816SMartin Matuska
64eda14cbcSMatt Macy /*
6516038816SMartin Matuska * We do not use gethostid(3) because it can return a bogus ID,
6616038816SMartin Matuska * depending on the libc and /etc/hostid presence,
6716038816SMartin Matuska * and the kernel and userspace must agree.
68eda14cbcSMatt Macy * See comments above hostid_read() in the SPL.
69eda14cbcSMatt Macy */
7016038816SMartin Matuska if (hostid == 0) {
7116038816SMartin Matuska int fd = open("/etc/hostid", O_RDONLY | O_CLOEXEC);
72eda14cbcSMatt Macy if (fd >= 0) {
73*dbd5678dSMartin Matuska if (read(fd, &system_hostid, sizeof (system_hostid))
74*dbd5678dSMartin Matuska != sizeof (system_hostid))
7516038816SMartin Matuska hostid = 0;
76*dbd5678dSMartin Matuska else
77*dbd5678dSMartin Matuska hostid = system_hostid;
7816038816SMartin Matuska (void) close(fd);
79eda14cbcSMatt Macy }
80eda14cbcSMatt Macy }
8116038816SMartin Matuska
8216038816SMartin Matuska return (hostid & HOSTID_MASK);
83eda14cbcSMatt Macy }
84