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# $FreeBSD$ 28 29# On entry to this script the entire system consists of a read-only root 30# mounted via NFS. The kernel has run BOOTP and configured an interface 31# (otherwise it would not have been able to mount the NFS root!) 32# 33# We use the contents of /conf to create and populate memory filesystems 34# that are mounted on top of this root to implement the writable 35# (and host-specific) parts of the root filesystem, and other volatile 36# filesystems. 37# 38# The hierarchy in /conf has the form /conf/T/M/ where M are directories 39# for which memory filesystems will be created and filled, 40# and T is one of the "template" directories below: 41# 42# base universal base, typically a replica of the original root; 43# default secondary universal base, typically overriding some 44# of the files in the original root; 45# ${ipba} where ${ipba} is the assigned broadcast IP address 46# bcast/${ipba} same as above 47# ${class} where ${class} is a list of directories supplied by 48# bootp/dhcp through the T134 option. 49# ${ipba} and ${class} are typically used to configure features 50# for group of diskless clients, or even individual features; 51# ${ip} where ${ip} is the machine's assigned IP address, typically 52# used to set host-specific features; 53# ip/${ip} same as above 54# 55# Template directories are scanned in the order they are listed above, 56# with each successive directory overriding (merged into) the previous one; 57# non-existing directories are ignored. The subdirectory forms exist to 58# help keep the top level /conf manageable in large installations. 59# 60# The existence of a directory /conf/T/M causes this script to create a 61# memory filesystem mounted as /M on the client. 62# 63# Some files in /conf have special meaning, namely: 64# 65# Filename Action 66# ---------------------------------------------------------------- 67# /conf/T/M/remount 68# The contents of the file is a mount command. E.g. if 69# /conf/1.2.3.4/foo/remount contains "mount -o ro /dev/ad0s3", 70# then /dev/ad0s3 will be be mounted on /conf/1.2.3.4/foo/ 71# 72# /conf/T/M/remount_optional 73# If this file exists, then failure to execute the mount 74# command contained in /conf/T/M/remount is non-fatal. 75# 76# /conf/T/M/remount_subdir 77# If this file exists, then the behaviour of /conf/T/M/remount 78# changes as follows: 79# 1. /conf/T/M/remount is invoked to mount the root of the 80# filesystem where the configuration data exists on a 81# temporary mountpoint. 82# 2. /conf/T/M/remount_subdir is then invoked to mount a 83# *subdirectory* of the filesystem mounted by 84# /conf/T/M/remount on /conf/T/M/. 85# 86# /conf/T/M/diskless_remount 87# The contents of the file points to an NFS filesystem, 88# possibly followed by mount_nfs options. If the server name 89# is omitted, the script will prepend the root path used when 90# booting. E.g. if you booted from foo.com:/path/to/root, 91# an entry for /conf/base/etc/diskless_remount could be any of 92# foo.com:/path/to/root/etc 93# /etc -o ro 94# Because mount_nfs understands ".." in paths, it is 95# possible to mount from locations above the NFS root with 96# paths such as "/../../etc". 97# 98# /conf/T/M/md_size 99# The contents of the file specifies the size of the memory 100# filesystem to be created, in 512 byte blocks. 101# The default size is 10240 blocks (5MB). E.g. if 102# /conf/base/etc/md_size contains "30000" then a 15MB MFS 103# will be created. In case of multiple entries for the same 104# directory M, the last one in the scanning order is used. 105# NOTE: If you only need to create a memory filesystem but not 106# initialize it from a template, it is preferrable to specify 107# it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0" 108# 109# /conf/T/SUBDIR.cpio.gz 110# The file is cpio'd into /SUBDIR (and a memory filesystem is 111# created for /SUBDIR if necessary). The presence of this file 112# prevents the copy from /conf/T/SUBDIR/ 113# 114# /conf/T/SUBDIR.remove 115# The list of paths contained in the file are rm -rf'd 116# relative to /SUBDIR. 117# 118# /conf/diskless_remount 119# Similar to /conf/T/M/diskless_remount above, but allows 120# all of /conf to be remounted. This can be used to allow 121# multiple roots to share the same /conf. 122# 123# 124# You will almost universally want to create the following files under /conf 125# 126# File Content 127# ---------------------------- ---------------------------------- 128# /conf/base/etc/md_size size of /etc filesystem 129# /conf/base/etc/diskless_remount "/etc" 130# /conf/default/etc/rc.conf generic diskless config parameters 131# /conf/default/etc/fstab generic diskless fstab e.g. like this 132# 133# foo:/root_part / nfs ro 0 0 134# foo:/usr_part /usr nfs ro 0 0 135# foo:/home_part /home nfs rw 0 0 136# md /tmp mfs -s=30m,rw 0 0 137# md /var mfs -s=30m,rw 0 0 138# proc /proc procfs rw 0 0 139# 140# plus, possibly, overrides for password files etc. 141# 142# NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g. 143# as entries in the fstab as above. 144# Those filesystems should not be specified in /conf. 145# 146# (end of documentation, now get to the real code) 147 148dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` 149 150# DEBUGGING 151# log something on stdout if verbose. 152o_verbose=0 # set to 1 or 2 if you want more debugging 153log() { 154 [ ${o_verbose} -gt 0 ] && echo "*** $* ***" 155 [ ${o_verbose} -gt 1 ] && read -p "=== Press enter to continue" foo 156} 157 158# chkerr: 159# 160# Routine to check for error 161# 162# checks error code and drops into shell on failure. 163# if shell exits, terminates script as well as /etc/rc. 164# if remount_optional exists under the mountpoint, skip this check. 165# 166chkerr() { 167 lastitem () ( n=$(($# - 1)) ; shift $n ; echo $1 ) 168 mountpoint="$(lastitem $2)" 169 [ -r $mountpoint/remount_optional ] && ( echo "$2 failed: ignoring due to remount_optional" ; return ) 170 case $1 in 171 0) 172 ;; 173 *) 174 echo "$2 failed: dropping into /bin/sh" 175 /bin/sh 176 # RESUME 177 ;; 178 esac 179} 180 181# The list of filesystems to umount after the copy 182to_umount="" 183 184handle_remount() { # $1 = mount point 185 local nfspt mountopts b 186 b=$1 187 log handle_remount $1 188 [ -d $b -a -f $b/diskless_remount ] || return 189 read nfspt mountopts < $b/diskless_remount 190 log "nfspt ${nfspt} mountopts ${mountopts}" 191 # prepend the nfs root if not present 192 [ `expr "$nfspt" : '\(.\)'` = "/" ] && nfspt="${nfsroot}${nfspt}" 193 mount_nfs $mountopts $nfspt $b 194 chkerr $? "mount_nfs $nfspt $b" 195 to_umount="$b ${to_umount}" 196} 197 198# Create a generic memory disk 199# 200mount_md() { 201 /sbin/mdmfs -S -i 4096 -s $1 -M md $2 202} 203 204# Create the memory filesystem if it has not already been created 205# 206create_md() { 207 [ "x`eval echo \\$md_created_$1`" = "x" ] || return # only once 208 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then 209 md_size=10240 210 else 211 md_size=`eval echo \\$md_size_$1` 212 fi 213 log create_md $1 with size $md_size 214 mount_md $md_size /$1 215 /bin/chmod 755 /$1 216 eval md_created_$1=created 217} 218 219# DEBUGGING 220# 221# set -v 222 223# Figure out our interface and IP. 224# 225bootp_ifc="" 226bootp_ipa="" 227bootp_ipbca="" 228class="" 229if [ ${dlv:=0} -ne 0 ] ; then 230 iflist=`ifconfig -l` 231 for i in ${iflist} ; do 232 set -- `ifconfig ${i}` 233 while [ $# -ge 1 ] ; do 234 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then 235 bootp_ifc=${i} ; bootp_ipa=${2} ; shift 236 fi 237 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then 238 bootp_ipbca=$2; shift 239 fi 240 shift 241 done 242 if [ "${bootp_ifc}" != "" ] ; then 243 break 244 fi 245 done 246 # Get the values passed with the T134 bootp cookie. 247 class="`/sbin/sysctl -qn kern.bootp_cookie`" 248 249 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}" 250fi 251 252log Figure out our NFS root path 253# 254set -- `mount -t nfs` 255while [ $# -ge 1 ] ; do 256 if [ "$2" = "on" -a "$3" = "/" ]; then 257 nfsroot="$1" 258 break 259 fi 260 shift 261done 262 263# The list of directories with template files 264templates="base default" 265if [ -n "${bootp_ipbca}" ]; then 266 templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}" 267fi 268if [ -n "${class}" ]; then 269 templates="${templates} ${class}" 270fi 271if [ -n "${bootp_ipa}" ]; then 272 templates="${templates} ${bootp_ipa} ip/${bootp_ipa}" 273fi 274 275# If /conf/diskless_remount exists, remount all of /conf. 276handle_remount /conf 277 278# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca}, 279# and /conf/${bootp_ipa}. For each subdirectory found within these 280# directories: 281# 282# - calculate memory filesystem sizes. If the subdirectory (prior to 283# NFS remounting) contains the file 'md_size', the contents specified 284# in 512 byte sectors will be used to size the memory filesystem. Otherwise 285# 8192 sectors (4MB) is used. 286# 287# - handle NFS remounts. If the subdirectory contains the file 288# diskless_remount, the contents of the file is NFS mounted over 289# the directory. For example /conf/base/etc/diskless_remount 290# might contain 'myserver:/etc'. NFS remounts allow you to avoid 291# having to dup your system directories in /conf. Your server must 292# be sure to export those filesystems -alldirs, however. 293# If the diskless_remount file contains a string beginning with a 294# '/' it is assumed that the local nfsroot should be prepended to 295# it before attemping to the remount. This allows the root to be 296# relocated without needing to change the remount files. 297# 298log "templates are ${templates}" 299for i in ${templates} ; do 300 for j in /conf/$i/* ; do 301 [ -d $j ] || continue 302 303 # memory filesystem size specification 304 subdir=${j##*/} 305 [ -f $j/md_size ] && eval md_size_$subdir=`cat $j/md_size` 306 307 # remount. Beware, the command is in the file itself! 308 if [ -f $j/remount ]; then 309 if [ -f $j/remount_subdir ]; then 310 k="/conf.tmp/$i/$subdir" 311 [ -d $k ] || continue 312 313 # Mount the filesystem root where the config data is 314 # on the temporary mount point. 315 nfspt=`/bin/cat $j/remount` 316 $nfspt $k 317 chkerr $? "$nfspt $k" 318 319 # Now use a nullfs mount to get the data where we 320 # really want to see it. 321 remount_subdir=`/bin/cat $j/remount_subdir` 322 remount_subdir_cmd="mount -t nullfs $k/$remount_subdir" 323 324 $remount_subdir_cmd $j 325 chkerr $? "$remount_subdir_cmd $j" 326 327 # XXX check order -- we must force $k to be unmounted 328 # after j, as j depends on k. 329 to_umount="$j $k ${to_umount}" 330 else 331 nfspt=`/bin/cat $j/remount` 332 $nfspt $j 333 chkerr $? "$nfspt $j" 334 to_umount="$j ${to_umount}" # XXX hope it is really a mount! 335 fi 336 fi 337 338 # NFS remount 339 handle_remount $j 340 done 341done 342 343# - Create all required MFS filesystems and populate them from 344# our templates. Support both a direct template and a dir.cpio.gz 345# archive. Support dir.remove files containing a list of relative 346# paths to remove. 347# 348# The dir.cpio.gz form is there to make the copy process more efficient, 349# so if the cpio archive is present, it prevents the files from dir/ 350# from being copied. 351 352for i in ${templates} ; do 353 for j in /conf/$i/* ; do 354 subdir=${j##*/} 355 if [ -d $j -a ! -f $j.cpio.gz ]; then 356 create_md $subdir 357 cp -Rp $j/ /$subdir 358 fi 359 done 360 for j in /conf/$i/*.cpio.gz ; do 361 subdir=${j%*.cpio.gz} 362 subdir=${subdir##*/} 363 if [ -f $j ]; then 364 create_md $subdir 365 echo "Loading /$subdir from cpio archive $j" 366 (cd / ; /rescue/tar -xpf $j) 367 fi 368 done 369 for j in /conf/$i/*.remove ; do 370 subdir=${j%*.remove} 371 subdir=${subdir##*/} 372 if [ -f $j ]; then 373 # doubly sure it is a memory disk before rm -rf'ing 374 create_md $subdir 375 (cd /$subdir; rm -rf `/bin/cat $j`) 376 fi 377 done 378done 379 380# umount partitions used to fill the memory filesystems 381[ -n "${to_umount}" ] && umount $to_umount 382