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Diffstat (limited to 'sys/contrib/openzfs/lib/libspl/os/linux/gethostid.c')
-rw-r--r--sys/contrib/openzfs/lib/libspl/os/linux/gethostid.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/lib/libspl/os/linux/gethostid.c b/sys/contrib/openzfs/lib/libspl/os/linux/gethostid.c
new file mode 100644
index 000000000000..1eb93f441142
--- /dev/null
+++ b/sys/contrib/openzfs/lib/libspl/os/linux/gethostid.c
@@ -0,0 +1,86 @@
+/*
+ * 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) {
+ hostid = strtoull(env, NULL, 0);
+ return (hostid & HOSTID_MASK);
+ }
+
+ f = fopen("/sys/module/spl/parameters/spl_hostid", "r");
+ if (!f)
+ return (0);
+
+ if (fscanf(f, "%lu", &hostid) != 1)
+ hostid = 0;
+
+ fclose(f);
+
+ return (hostid & HOSTID_MASK);
+}
+
+unsigned long
+get_system_hostid(void)
+{
+ unsigned long system_hostid = get_spl_hostid();
+ /*
+ * We do not use the library call gethostid() because
+ * it generates a hostid value that the kernel is
+ * unaware of, if the spl_hostid module parameter has not
+ * been set and there is no system hostid file (e.g.
+ * /etc/hostid). The kernel and userspace must agree.
+ * See comments above hostid_read() in the SPL.
+ */
+ if (system_hostid == 0) {
+ int fd, rc;
+ unsigned long hostid;
+ int hostid_size = 4; /* 4 bytes regardless of arch */
+
+ fd = open("/etc/hostid", O_RDONLY);
+ if (fd >= 0) {
+ rc = read(fd, &hostid, hostid_size);
+ if (rc > 0)
+ system_hostid = (hostid & HOSTID_MASK);
+ close(fd);
+ }
+ }
+ return (system_hostid);
+}