diff options
Diffstat (limited to 'sys/contrib/openzfs/lib/libspl/os/linux/gethostid.c')
-rw-r--r-- | sys/contrib/openzfs/lib/libspl/os/linux/gethostid.c | 86 |
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); +} |