rc.initdiskless revision 127663
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 127663 2004-03-31 08:43:20Z luigi $ 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. The kernel has run BOOTP and configured an interface 35# (otherwise it would not have been able to mount the NFS root!) 36# 37# We use the contents of /conf to create and populate memory filesystems 38# that are mounted on top of this root to implement the writable 39# (and host-specific) parts of the root filesystem, and other volatile 40# filesystems. 41# 42# The hierarchy in /conf has the form /conf/T/M/ where M are directories 43# for which memory filesystems will be created and filled, 44# and T is one of the "template" directories below: 45# 46# base universal base, typically a replica of the original root; 47# default secondary universal base, typically overriding some 48# of the files in the original root; 49# ${ipba} where ${ipba} is the assigned broadcast IP address 50# ${class} where ${class} is a list of directories supplied by 51# bootp/dhcp through the T134 option. 52# ${ipba} and ${class} are typicall used to configure features 53# for group of diskless clients, or even individual features; 54# ${ip} where ${ip} is the machine's assigned IP address, typically 55# used to set host-specific features; 56# 57# Template directories are scanned in the order they are listed above, 58# with each sucessive directory overriding (merged into) the previous one; 59# non-existing directories are ignored. 60# 61# The existence of a directory /conf/T/M causes this script to create a 62# memory filesystem mounted as /M on the client. 63# 64# Some files in /conf have special meaning, namely: 65# 66# Filename Action 67# ---------------------------------------------------------------- 68# /conf/T/M/remount 69# The contents of the file is a mount command. E.g. if 70# /conf/1.2.3.4/foo/remount contains "mount -o ro /dev/ad0s3", 71# then /dev/ad0s3 will be be mounted on /conf/1.2.3.4/foo/ 72# 73# /conf/T/M/diskless_remount 74# The contents of the file points to an NFS filesystem. E.g. if 75# /conf/base/etc/diskless_remount contains "foo.com:/etc", 76# then foo.com:/etc will be be mounted on /conf/base/etc/ 77# If the file contains a pathname starting with "/", then 78# the root path is prepended to it; this allows relocation of 79# the root filesystem withouth changing configuration files. 80# 81# /conf/T/M/md_size 82# The contents of the file specifies the size of the memory 83# filesystem to be created, in 512 byte blocks. 84# The default size is 10240 blocks (5MB). E.g. if 85# /conf/base/etc/md_size contains "30000" then a 15MB MFS 86# will be created. In case of multiple entries for the same 87# directory M, the last one in the scanning order is used. 88# NOTE: If you only need to create a memory filesystem but not 89# initialize it from a template, it is preferrable to specify 90# it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0" 91# 92# /conf/T/SUBDIR.cpio.gz 93# The file is cpio'd into /SUBDIR (and a memory filesystem is 94# created for /SUBDIR if necessary). The presence of this file 95# prevents the copy from /conf/T/SUBDIR/ 96# 97# /conf/T/SUBDIR.remove 98# The list of paths contained in the file are rm -rf'd 99# relative to /SUBDIR. 100# 101# You will almost universally want to create the following files under /conf 102# 103# File Content 104# ---------------------------- ------------------------------------------ 105# /conf/base/etc/md_size size of /etc filesystem 106# /conf/base/diskless_remount "/etc" 107# /conf/default/etc/rc.conf generic diskless config parameters 108# /conf/default/etc/fstab generic diskless fstab e.g. like this 109# 110# foo:/root_part / nfs ro 0 0 111# foo:/usr_part /usr nfs ro 0 0 112# foo:/home_part /home nfs rw 0 0 113# md /tmp mfs -s=30m,rw 0 0 114# md /var mfs -s=30m,rw 0 0 115# proc /proc procfs rw 0 0 116# 117# plus, possibly, overrides for password files etc. 118# 119# NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g. 120# as entries in the fstab as above. 121# Those filesystems should not be specified in /conf. 122# 123# (end of documentation, now get to the real code) 124 125dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` 126[ ${dlv:=0} -eq 0 ] && [ ! -f /etc/diskless ] && exit 0 127 128# chkerr: 129# 130# Routine to check for error 131# 132# checks error code and drops into shell on failure. 133# if shell exits, terminates script as well as /etc/rc. 134# 135chkerr() { 136 case $1 in 137 0) 138 ;; 139 *) 140 echo "$2 failed: dropping into /bin/sh" 141 /bin/sh 142 # RESUME 143 ;; 144 esac 145} 146 147# Create a generic memory disk 148# 149mount_md() { 150 /sbin/mdmfs -i 4096 -s $1 -M md $2 151} 152 153# Create the memory filesystem if it has not already been created 154# 155create_md() { 156 if [ "x`eval echo \\$md_created_$1`" = "x" ]; then 157 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then 158 md_size=10240 159 else 160 md_size=`eval echo \\$md_size_$1` 161 fi 162 mount_md $md_size /$1 163 /bin/chmod 755 /$1 164 eval md_created_$1=created 165 fi 166} 167 168# DEBUGGING 169# 170# set -v 171 172# Figure out our interface and IP. 173# 174bootp_ifc="" 175bootp_ipa="" 176bootp_ipbca="" 177if [ ${dlv:=0} -ne 0 ] ; then 178 iflist=`ifconfig -l` 179 for i in ${iflist} ; do 180 set `ifconfig ${i}` 181 while [ $# -ge 1 ] ; do 182 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then 183 bootp_ifc=${i} ; bootp_ipa=${2} ; shift 184 fi 185 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then 186 bootp_ipbca=$2; shift 187 fi 188 shift 189 done 190 if [ "${bootp_ifc}" != "" ] ; then 191 break 192 fi 193 done 194 # Insert the directories passed with the T134 bootp cookie 195 # in the list of paths used for templates. 196 i="`/sbin/sysctl -n kern.bootp_cookie`" 197 [ "${i}" != "" ] && bootp_ipbca="${bootp_ipbca} ${i}" 198 199 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}" 200fi 201 202# Figure out our NFS root path 203# 204set `mount -t nfs` 205while [ $# -ge 1 ] ; do 206 if [ "$2" = "on" -a "$3" = "/" ]; then 207 nfsroot="$1" 208 break 209 fi 210 shift 211done 212 213# The list of directories with template files 214templates="base default ${bootp_ipbca} ${bootp_ipa}" 215 216# The list of filesystems to umount after the copy 217to_umount="" 218 219# If /conf/diskless_remount exists, remount all of /conf. This allows 220# multiple roots to share the same conf files. 221if [ -d /conf -a -f /conf/diskless_remount ]; then 222 nfspt=`/bin/cat /conf/diskless_remount` 223 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 224 nfspt="${nfsroot}${nfspt}" 225 fi 226 mount_nfs $nfspt /conf 227 chkerr $? "mount_nfs $nfspt /conf" 228 to_umount="/conf" 229fi 230 231# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca}, 232# and /conf/${bootp_ipa}. For each subdirectory found within these 233# directories: 234# 235# - calculate memory filesystem sizes. If the subdirectory (prior to 236# NFS remounting) contains the file 'md_size', the contents specified 237# in 512 byte sectors will be used to size the memory filesystem. Otherwise 238# 8192 sectors (4MB) is used. 239# 240# - handle NFS remounts. If the subdirectory contains the file 241# diskless_remount, the contents of the file is NFS mounted over 242# the directory. For example /conf/base/etc/diskless_remount 243# might contain 'myserver:/etc'. NFS remounts allow you to avoid 244# having to dup your system directories in /conf. Your server must 245# be sure to export those filesystems -alldirs, however. 246# If the diskless_remount file contains a string beginning with a 247# '/' it is assumed that the local nfsroot should be prepended to 248# it before attemping to the remount. This allows the root to be 249# relocated without needing to change the remount files. 250# 251for i in ${templates} ; do 252 for j in /conf/$i/* ; do 253 # memory filesystem size specification 254 # 255 subdir=${j##*/} 256 if [ -d $j -a -f $j/md_size ]; then 257 eval md_size_$subdir=`cat $j/md_size` 258 fi 259 260 # remount 261 # 262 if [ -d $j -a -f $j/remount ]; then 263 nfspt=`/bin/cat $j/remount` 264 $nfspt $j 265 chkerr $? "$nfspt $j" 266 to_umount="${to_umount} $j" # XXX hope it is really a mount! 267 fi 268 269 # NFS remount 270 # 271 if [ -d $j -a -f $j/diskless_remount ]; then 272 nfspt=`/bin/cat $j/diskless_remount` 273 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 274 nfspt="${nfsroot}${nfspt}" 275 fi 276 mount_nfs $nfspt $j 277 chkerr $? "mount_nfs $nfspt $j" 278 to_umount="${to_umount} $j" 279 fi 280 done 281done 282 283# - Create all required MFS filesystems and populate them from 284# our templates. Support both a direct template and a dir.cpio.gz 285# archive. Support dir.remove files containing a list of relative 286# paths to remove. 287# 288# The dir.cpio.gz form is there to make the copy process more efficient, 289# so if the cpio archive is present, it prevents the files from dir/ 290# from being copied. 291 292for i in ${templates} ; do 293 for j in /conf/$i/* ; do 294 subdir=${j##*/} 295 if [ -d $j -a ! -f $j.cpio.gz ]; then 296 create_md $subdir 297 cp -Rp $j/* /$subdir 298 fi 299 done 300 for j in /conf/$i/*.cpio.gz ; do 301 subdir=${j%*.cpio.gz} 302 subdir=${subdir##*/} 303 if [ -f $j ]; then 304 create_md $subdir 305 echo "Loading /$subdir from cpio archive $j" 306 (cd / ; /stand/gzip -d < $j | /stand/cpio --extract -d ) 307 fi 308 done 309 for j in /conf/$i/*.remove ; do 310 subdir=${j%*.remove} 311 subdir=${subdir##*/} 312 if [ -f $j ]; then 313 # doubly sure it is a memory disk before rm -rf'ing 314 create_md $subdir 315 (cd /$subdir; rm -rf `/bin/cat $j`) 316 fi 317 done 318done 319 320# umount partitions used to fill the memory filesystems 321[ -n "${to_umount}" ] && umount $to_umount 322