Re: [nfs-utils PATCH] nfs4id: a tool to create and persist nfs4 client uniquifiers

[Steve Dickson <steved@redhat.com>]

On 2/8/22 11:21 AM, Chuck Lever III wrote:
> 
> 
>> On Feb 8, 2022, at 11:04 AM, Steve Dickson <steved@redhat.com> wrote:
>>
>> Hello,
>>
>> On 2/4/22 7:56 AM, Benjamin Coddington wrote:
>>> The nfs4id 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/nfs4-id.  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@redhat.com>
>>> ---
>>>   .gitignore               |   1 +
>>>   configure.ac             |   4 +
>>>   tools/Makefile.am        |   1 +
>>>   tools/nfs4id/Makefile.am |   8 ++
>>>   tools/nfs4id/nfs4id.c    | 184 +++++++++++++++++++++++++++++++++++++++
>>>   tools/nfs4id/nfs4id.man  |  29 ++++++
>>>   6 files changed, 227 insertions(+)
>>>   create mode 100644 tools/nfs4id/Makefile.am
>>>   create mode 100644 tools/nfs4id/nfs4id.c
>>>   create mode 100644 tools/nfs4id/nfs4id.man
>> Just a nit... naming convention... In the past
>> we never put the protocol version in the name.
>> Do a ls tools and utils directory and you
>> see what I mean....
>>
>> Would it be a problem to change the name from
>> nfs4id to nfsid?
> 
> nfs4id is pretty generic, too.
> 
> Can we go with nfs-client-id ?
I'm never been big with putting '-'
in command names... nfscltid would
be better IMHO... if we actually
need the 'clt' in the name.

steved.

> 
> 
>> steved.
>>
>>> diff --git a/.gitignore b/.gitignore
>>> index c89d1cd2583d..a37964148dd8 100644
>>> --- a/.gitignore
>>> +++ b/.gitignore
>>> @@ -61,6 +61,7 @@ utils/statd/statd
>>>   tools/locktest/testlk
>>>   tools/getiversion/getiversion
>>>   tools/nfsconf/nfsconf
>>> +tools/nfs4id/nfs4id
>>>   support/export/mount.h
>>>   support/export/mount_clnt.c
>>>   support/export/mount_xdr.c
>>> diff --git a/configure.ac b/configure.ac
>>> index 50e9b321dcf3..93d0a902cfd8 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/nfs4id/Makefile
>>>   	utils/Makefile
>>>   	utils/blkmapd/Makefile
>>>   	utils/nfsdcld/Makefile
>>> diff --git a/tools/Makefile.am b/tools/Makefile.am
>>> index 9b4b0803db39..cc658f69bb32 100644
>>> --- a/tools/Makefile.am
>>> +++ b/tools/Makefile.am
>>> @@ -7,6 +7,7 @@ OPTDIRS += rpcgen
>>>   endif
>>>     OPTDIRS += nfsconf
>>> +OPTDIRS += nfs4id
>>>     if CONFIG_NFSDCLD
>>>   OPTDIRS += nfsdclddb
>>> diff --git a/tools/nfs4id/Makefile.am b/tools/nfs4id/Makefile.am
>>> new file mode 100644
>>> index 000000000000..d1e60a35a510
>>> --- /dev/null
>>> +++ b/tools/nfs4id/Makefile.am
>>> @@ -0,0 +1,8 @@
>>> +## Process this file with automake to produce Makefile.in
>>> +
>>> +man8_MANS	= nfs4id.man
>>> +
>>> +bin_PROGRAMS = nfs4id
>>> +
>>> +nfs4id_SOURCES = nfs4id.c
>>> +nfs4id_LDADD = $(LIBUUID)
>>> diff --git a/tools/nfs4id/nfs4id.c b/tools/nfs4id/nfs4id.c
>>> new file mode 100644
>>> index 000000000000..dbb807ae21f3
>>> --- /dev/null
>>> +++ b/tools/nfs4id/nfs4id.c
>>> @@ -0,0 +1,184 @@
>>> +/*
>>> + * nfs4id.c -- create and persist uniquifiers for nfs4 clients
>>> + *
>>> + * Copyright (C) 2022  Red Hat, Benjamin Coddington <bcodding@redhat.com>
>>> + *
>>> + * 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 NFS4IDFILE "/etc/nfs4-id"
>>> +
>>> +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 nfs4_id[64];
>>> +static int force = 0;
>>> +
>>> +static void usage(void)
>>> +{
>>> +	fprintf(stderr, "usage: %s [-f|--force] [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_nfs4_id(void)
>>> +{
>>> +	int fd;
>>> +
>>> +	fd = open(NFS4IDFILE, O_RDONLY);
>>> +	if (fd < 0)
>>> +		return fd;
>>> +	read(fd, nfs4_id, 64);
>>> +	close(fd);
>>> +	return 0;
>>> +}
>>> +
>>> +static void write_nfs4_id(void)
>>> +{
>>> +	int fd;
>>> +
>>> +	fd = open(NFS4IDFILE, O_RDWR|O_TRUNC|O_CREAT, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
>>> +	if (fd < 0)
>>> +		fatal("could not write id to " NFS4IDFILE);
>>> +	write(fd, nfs4_id, 37);
>>> +}
>>> +
>>> +static void print_nfs4_id(void)
>>> +{
>>> +	fprintf(stdout, "%s", nfs4_id);
>>> +}
>>> +	
>>> +static void check_or_make_id(void)
>>> +{
>>> +	int ret;
>>> +	uuid_t nfs4id_uuid;
>>> +
>>> +	ret = read_nfs4_id();
>>> +	if (ret != 0) {
>>> +		if (errno != ENOENT )
>>> +			fatal("reading file " NFS4IDFILE);
>>> +		uuid_generate_random(nfs4id_uuid);
>>> +		uuid_unparse(nfs4id_uuid, nfs4_id);
>>> +		nfs4_id[36] = '\n';
>>> +		nfs4_id[37] = '\0';
>>> +		write_nfs4_id();
>>> +	}
>>> +	print_nfs4_id();	
>>> +}
>>> +
>>> +static void check_or_make_id_from_machine(void)
>>> +{
>>> +	int fd, ret;
>>> +	char machineid[32];
>>> +	uuid_t nfs4id_uuid;
>>> +
>>> +	ret = read_nfs4_id();
>>> +	if (ret != 0) {
>>> +		if (errno != ENOENT )
>>> +			fatal("reading file " NFS4IDFILE);
>>> +
>>> +		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(nfs4id_uuid, nfs4_clientid_uuid_template, machineid, 32);
>>> +		uuid_unparse(nfs4id_uuid, nfs4_id);
>>> +		nfs4_id[36] = '\n';
>>> +		nfs4_id[37] = '\0';
>>> +		write_nfs4_id();
>>> +	}
>>> +	print_nfs4_id();
>>> +}
>>> +
>>> +int main(int argc, char **argv)
>>> +{
>>> +	prog = argv[0];
>>> +
>>> +	while (1) {
>>> +		int opt;
>>> +		int option_index = 0;
>>> +		static struct option long_options[] = {
>>> +			{"force",	no_argument,	0, 'f' },
>>> +			{0,			0,				0, 0 }
>>> +		};
>>> +
>>> +		errno = 0;
>>> +		opt = getopt_long(argc, argv, ":f", long_options, &option_index);
>>> +		if (opt == -1)
>>> +			break;
>>> +
>>> +		switch (opt) {
>>> +		case 'f':
>>> +			force = 1;
>>> +			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 (force)
>>> +		unlink(NFS4IDFILE);
>>> +
>>> +	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/nfs4id/nfs4id.man b/tools/nfs4id/nfs4id.man
>>> new file mode 100644
>>> index 000000000000..358f836468a2
>>> --- /dev/null
>>> +++ b/tools/nfs4id/nfs4id.man
>>> @@ -0,0 +1,29 @@
>>> +.\"
>>> +.\" nfs4id(8)
>>> +.\"
>>> +.TH nfs4id 8 "3 Feb 2022"
>>> +.SH NAME
>>> +nfs4id \- Generate or return nfs4 client id uniqueifiers
>>> +.SH SYNOPSIS
>>> +.B nfs4id [ -f | --force ] [<source>]
>>> +
>>> +.SH DESCRIPTION
>>> +The
>>> +.B nfs4id
>>> +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/nfs4-id 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 \-f, \-\-force
>>> +Overwrite the existing /etc/nfs4-id with a UUID generated from <source>.
>>> +.SH Sources
>>> +If <source> is not specified, nfs4id will generate a new random UUID.
>>> +
>>> +If <source> is "machine", nfs4id 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)
> 
> --
> Chuck Lever
> 
> 
>