rc.d: Generate machine-id from hostid_save

rc.d/hostid_save saves a UUID generated by rc.d/hostid in /etc/hostid.
Store the same UUID, without hyphens, in /etc/machine-id.  The hypĥens
are removed with a shell function because hostid_save runs before file
systems are mounted so other tools may not be available yet.

This eliminates some duplication between hostid and machine-id and for
virtual machines machine-id now contains the UUID configured in the
hypervisor like it does on Linux.

Reviewed by:	delphij
Discussed with:	bapt
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D38811

7 files changed, 25 insertions, 49 deletions

diff --git a/ObsoleteFiles.inc b/ObsoleteFiles.inc
index 23bdd366f40b..7bbd91525cd5 100644
--- a/ObsoleteFiles.inc
+++ b/ObsoleteFiles.inc
@@ -52,6 +52,9 @@
 #   xargs -n1 | sort | uniq -d;
 # done
 
+# 20230308: machine-id merged into hostid_save
+OLD_FILES+=etc/rc.d/machine-id
+
 # 20230306: remove tzsetwall(3)
 OLD_FILES+=usr/share/man/man3/tzsetwall.3.gz
 
diff --git a/etc/Makefile b/etc/Makefile
index 88f890b91604..4e28739268e6 100644
--- a/etc/Makefile
+++ b/etc/Makefile
@@ -59,8 +59,6 @@ distribution:
 	${_+_}cd ${SRCTOP}/usr.sbin/rmt; ${MAKE} etc-rmt
 	${INSTALL_SYMLINK} -T "package=runtime" ../var/run/os-release \
 		${DESTDIR}/etc/os-release
-	${INSTALL_SYMLINK} -T "package=runtime" ../var/db/machine-id \
-		${DESTDIR}/etc/machine-id
 .if ${MK_UNBOUND} != "no"
 	if [ ! -e ${DESTDIR}/etc/unbound ]; then \
 		${INSTALL_SYMLINK} -T "package=unbound" \
diff --git a/libexec/rc/rc.conf b/libexec/rc/rc.conf
index 8a5f69dbef12..932fd2ace778 100644
--- a/libexec/rc/rc.conf
+++ b/libexec/rc/rc.conf
@@ -138,6 +138,7 @@ hostname=""			# Set this!
 hostid_enable="YES"		# Set host UUID.
 hostid_file="/etc/hostid"	# File with hostuuid.
 hostid_uuidgen_flags="-r"	# Flags to uuidgen.
+machine_id_file="/etc/machine-id"	# File with machine-id.
 nisdomainname="NO"		# Set to NIS domain if using NIS (or NO).
 dhclient_program="/sbin/dhclient"	# Path to dhcp client program.
 dhclient_flags=""		# Extra flags to pass to dhcp client.
@@ -696,9 +697,6 @@ harvest_mask="511"	# Entropy device harvests all but the very invasive sources.
 osrelease_enable="YES"	# Update /var/run/os-release on boot (or NO).
 osrelease_file="/var/run/os-release" # File to update for os-release.
 osrelease_perms="444"	# Default permission for os-release file.
-machine_id_enable="YES"	# Create /var/db/machine-id on boot if missing (or NO).
-machine_id_file="/var/db/machine-id"	# File to update for machine-id.
-machine_id_perms="444"	# Default permissions for machine-id file.
 dmesg_enable="YES"	# Save dmesg(8) to /var/run/dmesg.boot
 watchdogd_enable="NO"	# Start the software watchdog daemon
 watchdogd_flags=""	# Flags to watchdogd (if enabled)
diff --git a/libexec/rc/rc.d/Makefile b/libexec/rc/rc.d/Makefile
index e2019c60f196..9be66195e774 100644
--- a/libexec/rc/rc.d/Makefile
+++ b/libexec/rc/rc.d/Makefile
@@ -49,7 +49,6 @@ CONFS=	DAEMON \
 	local \
 	localpkg \
 	lockd \
-	machine_id \
 	mixer \
 	motd \
 	mountcritlocal \
diff --git a/libexec/rc/rc.d/hostid_save b/libexec/rc/rc.d/hostid_save
index f535ea2596f2..f737ed7f74cf 100755
--- a/libexec/rc/rc.d/hostid_save
+++ b/libexec/rc/rc.d/hostid_save
@@ -15,20 +15,32 @@ start_cmd="hostid_save"
 stop_cmd=":"
 rcvar="hostid_enable"
 
+hostid_machine_id()
+{
+	local IFS
+
+	IFS=-
+	set -- ${current_hostid}
+	IFS=
+	current_machine_id=$*
+}
+
 hostid_save()
 {
 	current_hostid=`$SYSCTL_N kern.hostuuid`
 
-	if [ -r ${hostid_file} ]; then
-		read saved_hostid < ${hostid_file}
-		if [ ${saved_hostid} = ${current_hostid} ]; then
-			exit 0
-		fi
+	read saved_hostid 2>/dev/null < ${hostid_file}
+	if [ "${saved_hostid}" != "${current_hostid}" ]; then
+		echo "${current_hostid}" > ${hostid_file} ||
+			warn "could not store hostuuid in ${hostid_file}."
 	fi
 
-	echo ${current_hostid} > ${hostid_file}
-	if [ $? -ne 0 ]; then
-		warn "could not store hostuuid in ${hostid_file}."
+	hostid_machine_id
+
+	read saved_machine_id 2>/dev/null < ${machine_id_file}
+	if [ "${saved_machine_id}" != "${current_machine_id}" ]; then
+		echo "${current_machine_id}" > ${machine_id_file} ||
+			warn "could not store hostuuid in ${machine_id_file}."
 	fi
 }
 
diff --git a/libexec/rc/rc.d/machine_id b/libexec/rc/rc.d/machine_id
deleted file mode 100644
index 8bf3e41d0603..000000000000
--- a/libexec/rc/rc.d/machine_id
+++ /dev/null
@@ -1,34 +0,0 @@
-#!/bin/sh
-#
-# $FreeBSD$
-#
-
-# PROVIDE: machine_id
-# REQUIRE: mountcritremote FILESYSTEMS
-# BEFORE:  LOGIN
-
-. /etc/rc.subr
-
-: ${machine_id_file:=/var/db/machine-id}
-: ${machine_id_perms:=444}
-name="machine_id"
-desc="Update ${machine_id_file}"
-rcvar="machine_id_enable"
-start_cmd="machine_id_start"
-stop_cmd=":"
-
-
-machine_id_start()
-{
-	if [ ! -f ${machine_id_file} ] ; then
-		startmsg -n "Creating ${machine_id_file} "
-		t=$(mktemp -t machine-id)
-		/bin/uuidgen -r -c -o $t
-		install -C -o root -g wheel -m ${machine_id_perms} "$t" "${machine_id_file}"
-		rm -f "$t"
-		startmsg 'done.'
-	fi
-}
-
-load_rc_config $name
-run_rc_command "$1"
diff --git a/sys/sys/param.h b/sys/sys/param.h
index bdc73475b8e9..353c0243b6d5 100644
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -76,7 +76,7 @@
  * cannot include sys/param.h and should only be updated here.
  */
 #undef __FreeBSD_version
-#define __FreeBSD_version 1400081
+#define __FreeBSD_version 1400082
 
 /*
  * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,