Revamp the way rc.diskless1 creates and populates memory filesystems. Make

the whole thing generic.  That is, /conf/base, /conf/default,
/conf/${ipba}, and /conf/${ip} are all handled the same way.

Introduce an NFS remounting feature via the /conf/base/<dir>/diskless_remount
so you can avoid dup'ing system directories in /conf (described in rc file).

Introduce a memory filesystem sizing feature via the /conf/base/<dir>/md_size
file that allows you to override the default memory filesystem size.

Introduce a file containing relative paths to remove for each memory filesystem
directory as /conf/base/<dirname>.remove.

Make the cpio feature more generic (applies to any filesystem) (aka
/conf/base/<dirname>.cpio.gz).

Allow any root directories to be created as a memory filesystem via the
/conf/*/* mechanism.

Replace the copyright notice with a reference to the COPYRIGHT file and
do other cleanups.

(documentation and man page updates to follow).

MFC after:	3 days

1 files changed, 152 insertions, 72 deletions

diff --git a/etc/rc.diskless1 b/etc/rc.diskless1
index bdda6d8..fad8f86 100644
--- a/etc/rc.diskless1
+++ b/etc/rc.diskless1
@@ -1,43 +1,58 @@
-# Copyright (c) 1999  Matt Dillion
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-# 1. Redistributions of source code must retain the above copyright
-#    notice, this list of conditions and the following disclaimer.
-# 2. Redistributions in binary form must reproduce the above copyright
-#    notice, this list of conditions and the following disclaimer in the
-#    documentation and/or other materials provided with the distribution.
-#
-# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
-# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
-# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-# SUCH DAMAGE.
+# Copyright (c) 1999-2002  Matt Dillion.  Terms and conditions based on
+# the FreeBSD copyright as found at the base of the source distribution.
 #
 # $FreeBSD$
 #
-
-#
 # /etc/rc.diskless1 - general BOOTP startup
 #
-# BOOTP has mounted / for us.  Assume a read-only mount.  We must then
-# - figure out our IP by querying the interface
-# - mount /etc as an MFS
-# - populate /etc from /conf/default version
-# - override files in /etc with files from /conf/*/etc where
-#   '*' is default, netmask of client, ip-address of client
-#
-# The operator is in charge of setting /conf/*/etc/* things as appropriate.
-# Typically rc.conf and fstab need to be changed, but possibly also other
-# files such as inetd.conf etc.
+# On entry to this script the entire system consists of a read-only root
+# mounted via NFS.  We use the contents of /conf to create and populate
+# memory filesystems.  The kernel has run BOOTP and configured an interface
+# (otherwise it would not have been able to mount the NFS root!)
+#
+# The following directories are scanned.  Each sucessive directory overrides
+# (is merged into) the previous one.
+#
+#	/conf/base		universal base
+#	/conf/default		modified by a secondary universal base
+#	/conf/${ipba}		modified based on the assigned broadcast IP
+#	/conf/${ip}		modified based on the machine's assigned IP
+#
+# Each of these directories may contain any number of subdirectories which
+# represent directories in / on the diskless machine.  The existance of
+# these subdirectories causes this script to create a MEMORY FILESYSTEM for
+# /<sub_directory_name>.  For example, if /conf/base/etc exists then a
+# memory filesystem will be created for /etc.
+#
+# If a subdirectory contains the file 'diskless_remount' the contents of
+# the file is used to remount the subdirectory prior to it being copied to
+# the memory filesystem.  For example, if /conf/base/etc/diskless_remount
+# contains the string 'my.server.com:/etc' then my.server.com:/etc will be
+# mounted in place of the subdirectory.  This allows you to avoid making
+# duplicates of system directories in /conf.
+#
+# If a subdirectory contains the file 'md_size', the contents of the
+# file is used to determine the size of the memory filesystem, in 512
+# byte sectors.  The default is 8192 (4MB).  You only have to specify an
+# md_size if the default doesn't work for you (i.e. if it is too big or
+# too small).  Note that in -current the default is 4096 (2MB).  For
+# example, /conf/base/etc/md_size might contain '16384'.
+#
+# If /conf/<special_dir>/SUBDIR.cpio.gz exists, the file is cpio'd into
+# the specified /SUBDIR (and a memory filesystem is created for /SUBDIR
+# if necessary).
+#
+# If /conf/<special_dir>/SUBDIR.remove exists, the file contains a list
+# of paths which are rm -rf'd relative to /SUBDIR.
+#
+# You will almost universally want to create a /conf/base/etc containing
+# a diskless_remount and possibly an md_size file.  You will then almost
+# universally want to override rc.conf, rc.local, and fstab by creating
+# /conf/default/etc/{rc.conf,rc.local,fstab}.  Your fstab should be sure
+# to mount a /usr... typically an NFS readonly /usr.
+#
+# NOTE!  rc.diskless2 will create /var, /tmp, and /dev.  Those filesystems
+# should not be specified in /conf.  At least not yet.
 
 # chkerr:
 #
@@ -47,22 +62,39 @@
 #	if shell exits, terminates script as well as /etc/rc.
 #
 chkerr() {
-	case $1 in
-	0)
-		;;
-	*)
-		echo "$2 failed: dropping into /bin/sh"
-		/bin/sh
-		# RESUME
-		;;
-	esac
+    case $1 in
+    0)
+	;;
+    *)
+	echo "$2 failed: dropping into /bin/sh"
+	/bin/sh
+	# RESUME
+	;;
+    esac
 }
 
+# Create a generic memory disk
+#
 mount_md() {
-	/sbin/mdconfig -a -t malloc -s $1 -u $3
-	/sbin/disklabel -r -w md$3 auto
-	/sbin/newfs -i 4096 /dev/md$3c
-	/sbin/mount /dev/md$3c $2
+    /sbin/mdconfig -a -t malloc -s $1 -u $3
+    /sbin/disklabel -r -w md$3 auto
+    /sbin/newfs -i 4096 /dev/md$3c
+    /sbin/mount /dev/md$3c $2
+}
+
+# Create the memory filesystem if it has not already been created
+#
+create_md() {
+    if [ "x`eval echo \\$md_created_$1`" = "x" ]; then
+	if [ "x`eval echo \$md_size_$1`" = "x" ]; then
+	    md_size=4096
+	else
+	    md_size=`eval echo \\$md_size_$1`
+	fi
+	mount_md $md_size /$1 0
+	/bin/chmod 755 /$1
+	eval md_created_$1=created
+    fi
 }
 
 # DEBUGGING
@@ -92,36 +124,83 @@ for i in ${iflist} ; do
 done
 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}"
 
-if [ -z "`hostname -s`" ]; then
-        hostname=`kenv dhcp.host-name`
-        hostname $hostname
-	echo "Hostname is $hostname"
-fi
-
-if [ -d /conf/default/etc ]; then
-	mount_md 4096 /etc 0
-	chkerr $? "MFS mount on /etc"
-	/bin/chmod 755 /etc
+# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
+# and /conf/${bootp_ipa}.  For each subdirectory found within these 
+# directories:
+#
+# - calculate memory filesystem sizes.  If the subdirectory (prior to
+#   NFS remounting) contains the file 'md_size', the contents specified
+#   in 512 byte sectors will be used to size the memory filesystem.  Otherwise
+#   8192 sectors (4MB) is used.
+#
+# - handle NFS remounts.  If the subdirectory contains the file
+#   diskless_remount, the contents of the file is NFS mounted over
+#   the directory.  For example /conf/base/etc/diskless_remount
+#   might contain 'myserver:/etc'.  NFS remounts allow you to avoid
+#   having to dup your system directories in /conf.  Your server must
+#   be sure to export those filesystems -alldirs, however.
+#
+for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
+    for j in /conf/$i/* ; do
+	# memory filesystem size specification
+	#
+	subdir=${j##*/}
+	if [ -d $j -a -f $j/md_size ]; then
+	    eval md_size_$subdir=`cat $j/md_size`
+	fi
 
-	/bin/cp -Rp /conf/default/etc/* /etc
-	chkerr $? "cp /conf/default/etc to /etc MFS"
-fi
+	# NFS remount
+	#
+	if [ -d $j -a -f $j/diskless_remount ]; then
+	    mount_nfs `/bin/cat $j/diskless_remount` $j
+	    chkerr $? "mount_nfs `/bin/cat $j/diskless_remount` $j"
+	fi
+    done
+done
 
-# Allow for override files to replace files in /etc.  Use /conf/*/etc to find
-# the override files.  First choice is default files that # always override,
-# then files that from the directory that matches the client's broadcast
-# address, finally followed by overrides that match the client's IP address.
-#
-# This way we have some flexibility to handle clusters of machines on
-# separate subnets.
+# - Create all required MFS filesystems and populate them from
+#   our templates.  Support both a direct template and a dir.cpio.gz
+#   archive.  Support dir.remove files containing a list of relative
+#   paths to remove.
+#
+# TODO:
+#   + find a way to assign a 'group' identifier to a machine
+#	so we can use group-specific configurations;
 
-for i in ${bootp_ipbca} ${bootp_ipa} ${hostname} ; do
-	if [ -d /conf/${i}/etc ]; then
-		cp -Rp /conf/${i}/etc/* /etc
+for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
+    for j in /conf/$i/* ; do
+	subdir=${j##*/}
+	if [ -d $j ]; then
+	    create_md $subdir
+	    cp -Rp $j/* /$subdir
+	fi
+    done
+    for j in /conf/$i/*.cpio.gz ; do
+	subdir=${j%*.cpio.gz}
+	subdir=${subdir##*/}
+	if [ -f $j ]; then
+	    create_md $subdir
+	    echo "Loading /$subdir from cpio archive $j"
+	    (cd / ; /stand/gzip -d < $j | /stand/cpio --extract -d )
+	fi
+    done
+    for j in /conf/$i/*.remove ; do
+	subdir=${j%*.remove}
+	subdir=${subdir##*/}
+	if [ -f $j ]; then
+	    # doubly sure it is a memory disk before rm -rf'ing
+	    create_md $subdir
+	    (cd /$subdir; rm -rf `/bin/cat $j`)
 	fi
+    done
 done
 
-#
+if [ -z "`hostname -s`" ]; then
+        hostname=`kenv dhcp.host-name`
+        hostname $hostname
+	echo "Hostname is $hostname"
+fi
+
 # if the info is available via dhcp/kenv
 # build the resolv.conf
 #
@@ -142,3 +221,4 @@ fi
 # want to run the standard system /etc/rc.diskless2
 
 diskless_mount="/etc/rc.diskless2"
+