rc.initdiskless revision 126868
1#!/bin/sh
2#
3# Copyright (c) 1999  Matt Dillon
4# All rights reserved.
5#
6# Redistribution and use in source and binary forms, with or without
7# modification, are permitted provided that the following conditions
8# are met:
9# 1. Redistributions of source code must retain the above copyright
10#    notice, this list of conditions and the following disclaimer.
11# 2. Redistributions in binary form must reproduce the above copyright
12#    notice, this list of conditions and the following disclaimer in the
13#    documentation and/or other materials provided with the distribution.
14#
15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25# SUCH DAMAGE.
26#
27# $FreeBSD: head/etc/rc.initdiskless 126868 2004-03-12 04:40:16Z brooks $
28#
29# PROVIDE: initdiskless
30# KEYWORD: FreeBSD nojail
31
32
33# On entry to this script the entire system consists of a read-only root
34# mounted via NFS.  We use the contents of /conf to create and populate
35# memory filesystems.  The kernel has run BOOTP and configured an interface
36# (otherwise it would not have been able to mount the NFS root!)
37#
38# The following directories are scanned.  Each sucessive directory overrides
39# (is merged into) the previous one.
40#
41#	/conf/base		universal base
42#	/conf/default		modified by a secondary universal base
43#	/conf/${ipba}		modified based on the assigned broadcast IP
44#	/conf/${ip}		modified based on the machine's assigned IP
45#
46# Each of these directories may contain any number of subdirectories which
47# represent directories in / on the diskless machine.  The existance of
48# these subdirectories causes this script to create a MEMORY FILESYSTEM for
49# /<sub_directory_name>.  For example, if /conf/base/etc exists then a
50# memory filesystem will be created for /etc.
51#
52# If a subdirectory contains the file 'remount' the contents of the file
53# is a mount command used to remount the subdirectory prior to it being
54# copied.  An example contents could be: "mount -o ro /dev/ad0s3".  Note
55# that the directory to be mounted on is supplied by this script.
56#
57# If a subdirectory contains the file 'diskless_remount' the contents of
58# the file is used to remount the subdirectory prior to it being copied to
59# the memory filesystem.  For example, if /conf/base/etc/diskless_remount
60# contains the string 'my.server.com:/etc' then my.server.com:/etc will be
61# mounted in place of the subdirectory.  This allows you to avoid making
62# duplicates of system directories in /conf.  Special processing is done
63# to allow specifications relative to the root filesystem.
64#
65# If a subdirectory contains the file 'md_size', the contents of the
66# file is used to determine the size of the memory filesystem, in 512
67# byte sectors.  The default is 10240 (5MB).  You only have to specify an
68# md_size if the default doesn't work for you (i.e. if it is too big or
69# too small).  For example, /conf/base/etc/md_size might contain '16384'.
70#
71# If /conf/<special_dir>/SUBDIR.cpio.gz exists, the file is cpio'd into
72# the specified /SUBDIR (and a memory filesystem is created for /SUBDIR
73# if necessary).
74#
75# If /conf/<special_dir>/SUBDIR.remove exists, the file contains a list
76# of paths which are rm -rf'd relative to /SUBDIR.
77#
78# You will almost universally want to create a /conf/base/etc containing
79# a diskless_remount and possibly an md_size file.  You will then almost
80# universally want to override rc.conf, rc.local, and fstab by creating
81# /conf/default/etc/{rc.conf,rc.local,fstab}.  Your fstab should be sure
82# to mount a /usr... typically an NFS readonly /usr.
83#
84# NOTE!  /var, /tmp, and /dev will be created elsewhere.
85# Those filesystems should not be specified in /conf.
86
87dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null`
88[ ${dlv:=0} -eq 0 ] && [ ! -f /etc/diskless ] && exit 0
89
90# chkerr:
91#
92# Routine to check for error
93#
94#	checks error code and drops into shell on failure.
95#	if shell exits, terminates script as well as /etc/rc.
96#
97chkerr() {
98    case $1 in
99    0)
100	;;
101    *)
102	echo "$2 failed: dropping into /bin/sh"
103	/bin/sh
104	# RESUME
105	;;
106    esac
107}
108
109# Create a generic memory disk
110#
111mount_md() {
112    /sbin/mdmfs -i 4096 -s $1 -M md $2
113}
114
115# Create the memory filesystem if it has not already been created
116#
117create_md() {
118    if [ "x`eval echo \\$md_created_$1`" = "x" ]; then
119	if [ "x`eval echo \\$md_size_$1`" = "x" ]; then
120	    md_size=10240
121	else
122	    md_size=`eval echo \\$md_size_$1`
123	fi
124	mount_md $md_size /$1
125	/bin/chmod 755 /$1
126	eval md_created_$1=created
127    fi
128}
129
130# DEBUGGING
131#
132# set -v
133
134# Figure out our interface and IP.
135#
136bootp_ifc=""
137bootp_ipa=""
138bootp_ipbca=""
139if [ ${dlv:=0} -ne 0 ] ; then
140	iflist=`ifconfig -l`
141	for i in ${iflist} ; do
142	    set `ifconfig ${i}`
143	    while [ $# -ge 1 ] ; do
144		if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then
145		    bootp_ifc=${i} ; bootp_ipa=${2} ; shift
146		fi
147		if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then
148		    bootp_ipbca=$2; shift
149		fi
150		shift
151	    done
152	    if [ "${bootp_ifc}" != "" ] ; then
153		break
154	    fi
155	done
156	echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}"
157fi
158
159# Figure out our NFS root path
160#
161set `mount -t nfs`
162while [ $# -ge 1 ] ; do
163    if [ "$2" = "on" -a "$3" = "/" ]; then
164	nfsroot="$1"
165	break
166    fi
167    shift
168done
169
170# If /conf/diskless_remount exists, remount all of /conf.  This allows
171# multiple roots to share the same conf files.
172if [ -d /conf -a -f /conf/diskless_remount ]; then
173    nfspt=`/bin/cat /conf/diskless_remount`
174    if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then
175	nfspt="${nfsroot}${nfspt}"
176    fi
177    mount_nfs $nfspt /conf
178    chkerr $? "mount_nfs $nfspt /conf"
179fi
180
181# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
182# and /conf/${bootp_ipa}.  For each subdirectory found within these
183# directories:
184#
185# - calculate memory filesystem sizes.  If the subdirectory (prior to
186#   NFS remounting) contains the file 'md_size', the contents specified
187#   in 512 byte sectors will be used to size the memory filesystem.  Otherwise
188#   8192 sectors (4MB) is used.
189#
190# - handle NFS remounts.  If the subdirectory contains the file
191#   diskless_remount, the contents of the file is NFS mounted over
192#   the directory.  For example /conf/base/etc/diskless_remount
193#   might contain 'myserver:/etc'.  NFS remounts allow you to avoid
194#   having to dup your system directories in /conf.  Your server must
195#   be sure to export those filesystems -alldirs, however.
196#   If the diskless_remount file contains a string beginning with a
197#   '/' it is assumed that the local nfsroot should be prepended to
198#   it before attemping to the remount.  This allows the root to be
199#   relocated without needing to change the remount files.
200#
201for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
202    for j in /conf/$i/* ; do
203	# memory filesystem size specification
204	#
205	subdir=${j##*/}
206	if [ -d $j -a -f $j/md_size ]; then
207	    eval md_size_$subdir=`cat $j/md_size`
208	fi
209
210	# remount
211	#
212	if [ -d $j -a -f $j/remount ]; then
213	    nfspt=`/bin/cat $j/remount`
214	    $nfspt $j
215	    chkerr $? "$nfspt $j"
216	fi
217
218	# NFS remount
219	#
220	if [ -d $j -a -f $j/diskless_remount ]; then
221	    nfspt=`/bin/cat $j/diskless_remount`
222	    if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then
223		nfspt="${nfsroot}${nfspt}"
224	    fi
225	    mount_nfs $nfspt $j
226	    chkerr $? "mount_nfs $nfspt $j"
227	fi
228    done
229done
230
231# - Create all required MFS filesystems and populate them from
232#   our templates.  Support both a direct template and a dir.cpio.gz
233#   archive.  Support dir.remove files containing a list of relative
234#   paths to remove.
235#
236# TODO:
237#   + find a way to assign a 'group' identifier to a machine
238#	so we can use group-specific configurations;
239
240for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
241    for j in /conf/$i/* ; do
242	subdir=${j##*/}
243	if [ -d $j ]; then
244	    create_md $subdir
245	    cp -Rp $j/* /$subdir
246	fi
247    done
248    for j in /conf/$i/*.cpio.gz ; do
249	subdir=${j%*.cpio.gz}
250	subdir=${subdir##*/}
251	if [ -f $j ]; then
252	    create_md $subdir
253	    echo "Loading /$subdir from cpio archive $j"
254	    (cd / ; /stand/gzip -d < $j | /stand/cpio --extract -d )
255	fi
256    done
257    for j in /conf/$i/*.remove ; do
258	subdir=${j%*.remove}
259	subdir=${subdir##*/}
260	if [ -f $j ]; then
261	    # doubly sure it is a memory disk before rm -rf'ing
262	    create_md $subdir
263	    (cd /$subdir; rm -rf `/bin/cat $j`)
264	fi
265    done
266done
267
268