The nfsuuid program will either create a new UUID from a random source or
derive it from /etc/machine-id, else it returns a UUID that has already
been written to /etc/nfsuuid or the file specified. This small,
lightweight tool is suitable for execution by systemd-udev in rules to
populate the nfs4 client uniquifier.
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
---
.gitignore | 1 +
aclocal/libuuid.m4 | 17 ++++
configure.ac | 4 +
tools/Makefile.am | 1 +
tools/nfsuuid/Makefile.am | 8 ++
tools/nfsuuid/nfsuuid.c | 203 ++++++++++++++++++++++++++++++++++++++
tools/nfsuuid/nfsuuid.man | 33 +++++++
7 files changed, 267 insertions(+)
create mode 100644 aclocal/libuuid.m4
create mode 100644 tools/nfsuuid/Makefile.am
create mode 100644 tools/nfsuuid/nfsuuid.c
create mode 100644 tools/nfsuuid/nfsuuid.man
diff --git a/.gitignore b/.gitignore
index c89d1cd2583d..4d63ee93b2dc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -61,6 +61,7 @@ utils/statd/statd
tools/locktest/testlk
tools/getiversion/getiversion
tools/nfsconf/nfsconf
+tools/nfsuuid/nfsuuid
support/export/mount.h
support/export/mount_clnt.c
support/export/mount_xdr.c
diff --git a/aclocal/libuuid.m4 b/aclocal/libuuid.m4
new file mode 100644
index 000000000000..f64085010d1d
--- /dev/null
+++ b/aclocal/libuuid.m4
@@ -0,0 +1,17 @@
+AC_DEFUN([AC_LIBUUID], [
+ LIBUUID=
+
+ AC_CHECK_LIB([uuid], [uuid_generate_random], [], [AC_MSG_FAILURE(
+ [Missing libuuid uuid_generate_random, needed to build nfs4id])])
+
+ AC_CHECK_LIB([uuid], [uuid_generate_sha1], [], [AC_MSG_FAILURE(
+ [Missing libuuid uuid_generate_sha1, needed to build nfs4id])])
+
+ AC_CHECK_LIB([uuid], [uuid_unparse], [], [AC_MSG_FAILURE(
+ [Missing libuuid uuid_unparse, needed to build nfs4id])])
+
+ AC_CHECK_HEADER([uuid/uuid.h], [], [AC_MSG_FAILURE(
+ [Missing uuid/uuid.h, needed to build nfs4id])])
+
+ AC_SUBST([LIBUUID], ["-luuid"])
+])
diff --git a/configure.ac b/configure.ac
index 50e9b321dcf3..1342c471f142 100644
--- a/configure.ac
+++ b/configure.ac
@@ -355,6 +355,9 @@ if test "$enable_nfsv4" = yes; then
dnl check for the keyutils libraries and headers
AC_KEYUTILS
+ dnl check for the libuuid library and headers
+ AC_LIBUUID
+
dnl Check for sqlite3
AC_SQLITE3_VERS
@@ -740,6 +743,7 @@ AC_CONFIG_FILES([
tools/nfsdclnts/Makefile
tools/nfsconf/Makefile
tools/nfsdclddb/Makefile
+ tools/nfsuuid/Makefile
utils/Makefile
utils/blkmapd/Makefile
utils/nfsdcld/Makefile
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 9b4b0803db39..a12b0f34f4e7 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -7,6 +7,7 @@ OPTDIRS += rpcgen
endif
OPTDIRS += nfsconf
+OPTDIRS += nfsuuid
if CONFIG_NFSDCLD
OPTDIRS += nfsdclddb
diff --git a/tools/nfsuuid/Makefile.am b/tools/nfsuuid/Makefile.am
new file mode 100644
index 000000000000..7b3a54c30d50
--- /dev/null
+++ b/tools/nfsuuid/Makefile.am
@@ -0,0 +1,8 @@
+## Process this file with automake to produce Makefile.in
+
+man8_MANS = nfsuuid.man
+
+bin_PROGRAMS = nfsuuid
+
+nfsuuid_SOURCES = nfsuuid.c
+nfsuuid_LDADD = $(LIBUUID)
diff --git a/tools/nfsuuid/nfsuuid.c b/tools/nfsuuid/nfsuuid.c
new file mode 100644
index 000000000000..bbdec59f1afe
--- /dev/null
+++ b/tools/nfsuuid/nfsuuid.c
@@ -0,0 +1,203 @@
+/*
+ * nfsuuid.c -- create and persist uniquifiers for nfs4 clients
+ *
+ * Copyright (C) 2022 Red Hat, Benjamin Coddington <bcodding@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <getopt.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <uuid/uuid.h>
+
+#define DEFAULT_ID_FILE "/etc/nfsuuid"
+
+UUID_DEFINE(nfs4_clientid_uuid_template,
+ 0xa2, 0x25, 0x68, 0xb2, 0x7a, 0x5f, 0x49, 0x90,
+ 0x8f, 0x98, 0xc5, 0xf0, 0x67, 0x78, 0xcc, 0xf1);
+
+static char *prog;
+static char *source = NULL;
+static char *id_file = DEFAULT_ID_FILE;
+static char nfs_unique_id[64];
+static int replace = 0;
+
+static void usage(void)
+{
+ fprintf(stderr, "usage: %s [-r|--replace] [-f <file> |--file <file> ] [machine]\n", prog);
+}
+
+static void fatal(const char *fmt, ...)
+{
+ int err = errno;
+ va_list args;
+ char fatal_msg[256] = "fatal: ";
+
+ va_start(args, fmt);
+ vsnprintf(&fatal_msg[7], 255, fmt, args);
+ if (err)
+ fprintf(stderr, "%s: %s\n", fatal_msg, strerror(err));
+ else
+ fprintf(stderr, "%s\n", fatal_msg);
+ exit(-1);
+}
+
+static int read_nfs_unique_id(void)
+{
+ int fd;
+ ssize_t len;
+
+ if (replace) {
+ errno = ENOENT;
+ return -1;
+ }
+
+ fd = open(id_file, O_RDONLY);
+ if (fd < 0)
+ return fd;
+ len = read(fd, nfs_unique_id, 64);
+ close(fd);
+ return len;
+}
+
+static void write_nfs_unique_id(void)
+{
+ int fd;
+
+ fd = open(id_file, O_RDWR|O_TRUNC|O_CREAT, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
+ if (fd < 0)
+ fatal("could not write id to %s", id_file);
+ write(fd, nfs_unique_id, 37);
+}
+
+static void print_nfs_unique_id(void)
+{
+ fprintf(stdout, "%s", nfs_unique_id);
+}
+
+static void check_or_make_id(void)
+{
+ int ret;
+ uuid_t uuid;
+
+ ret = read_nfs_unique_id();
+ if (ret < 1) {
+ if (errno != ENOENT )
+ fatal("reading file %s", id_file);
+ uuid_generate_random(uuid);
+ uuid_unparse(uuid, nfs_unique_id);
+ nfs_unique_id[36] = '\n';
+ nfs_unique_id[37] = '\0';
+ write_nfs_unique_id();
+ }
+ print_nfs_unique_id();
+}
+
+static void check_or_make_id_from_machine(void)
+{
+ int fd, ret;
+ char machineid[32];
+ uuid_t uuid;
+
+ ret = read_nfs_unique_id();
+ if (ret < 1) {
+ if (errno != ENOENT )
+ fatal("reading file %s", id_file);
+
+ fd = open("/etc/machine-id", O_RDONLY);
+ if (fd < 0)
+ fatal("unable to read /etc/machine-id");
+
+ read(fd, machineid, 32);
+ close(fd);
+
+ uuid_generate_sha1(uuid, nfs4_clientid_uuid_template, machineid, 32);
+ uuid_unparse(uuid, nfs_unique_id);
+ nfs_unique_id[36] = '\n';
+ nfs_unique_id[37] = '\0';
+ write_nfs_unique_id();
+ }
+ print_nfs_unique_id();
+}
+
+int main(int argc, char **argv)
+{
+ prog = argv[0];
+
+ while (1) {
+ int opt, prev_ind;
+ int option_index = 0;
+ static struct option long_options[] = {
+ {"replace", no_argument, 0, 'r' },
+ {"file", required_argument, 0, 'f' },
+ { 0, 0, 0, 0 }
+ };
+
+ errno = 0;
+ prev_ind = optind;
+ opt = getopt_long(argc, argv, ":rf:", long_options, &option_index);
+ if (opt == -1)
+ break;
+
+ /* Let's detect missing options in the middle of an option list */
+ if (optind == prev_ind + 2 && *optarg == '-') {
+ opt = ':';
+ --optind;
+ }
+
+ switch (opt) {
+ case 'r':
+ replace = 1;
+ break;
+ case 'f':
+ id_file = optarg;
+ break;
+ case ':':
+ usage();
+ fatal("option \"%s\" requires an argument", argv[prev_ind]);
+ break;
+ case '?':
+ usage();
+ fatal("unexpected arg \"%s\"", argv[optind - 1]);
+ break;
+ }
+ }
+
+ argc -= optind;
+
+ if (argc > 1) {
+ usage();
+ fatal("Too many arguments");
+ }
+
+ if (argc)
+ source = argv[optind++];
+
+ if (!source)
+ check_or_make_id();
+ else if (strcmp(source, "machine") == 0)
+ check_or_make_id_from_machine();
+ else {
+ usage();
+ fatal("unrecognized source %s\n", source);
+ }
+}
diff --git a/tools/nfsuuid/nfsuuid.man b/tools/nfsuuid/nfsuuid.man
new file mode 100644
index 000000000000..856d2f383e0f
--- /dev/null
+++ b/tools/nfsuuid/nfsuuid.man
@@ -0,0 +1,33 @@
+.\"
+.\" nfsuuid(8)
+.\"
+.TH nfsuuid 8 "10 Feb 2022"
+.SH NAME
+nfsuuid \- Generate or return nfs client id uniquifiers
+.SH SYNOPSIS
+.B nfsuuid [ -r | --replace ] [ -f | --file <file> ] [<source>]
+
+.SH DESCRIPTION
+The
+.B nfsuuid
+command provides a simple utility to help NFS Version 4 clients use unique
+and persistent client id values. The command checks for the existence of a
+file /etc/nfsuuid and returns the first 64 chars read from that file. If
+the file is not found, a UUID is generated from the specified source and
+written to the file and returned.
+.SH OPTIONS
+.TP
+.BR \-r,\ \-\-replace
+Overwrite the <file> with a UUID generated from <source>.
+.TP
+.BR \-f,\ \-\-file
+Use the specified file to lookup or store any generated UUID. If <file> is
+not specified, the default file used is /etc/nfsuuid.
+.SH Sources
+If <source> is not specified, nfsuuid will generate a new random UUID.
+
+If <source> is "machine", nfsuuid will generate a deterministic UUID value
+derived from a sha1 hash of the contents of /etc/machine-id and a static
+key.
+.SH SEE ALSO
+.BR machine-id (5)
--
2.31.1
