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Diffstat (limited to 'libexec/rc/rc.initdiskless')
| -rw-r--r-- | libexec/rc/rc.initdiskless | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/libexec/rc/rc.initdiskless b/libexec/rc/rc.initdiskless new file mode 100644 index 000000000000..3b66a3c4928a --- /dev/null +++ b/libexec/rc/rc.initdiskless @@ -0,0 +1,408 @@ +#!/bin/sh +# +# Copyright (c) 1999 Matt Dillon +# 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. +# + +# On entry to this script the entire system consists of a read-only root +# mounted via NFS. The kernel has run BOOTP and configured an interface +# (otherwise it would not have been able to mount the NFS root!) +# +# We use the contents of /conf to create and populate memory filesystems +# that are mounted on top of this root to implement the writable +# (and host-specific) parts of the root filesystem, and other volatile +# filesystems. +# +# The hierarchy in /conf has the form /conf/T/M/ where M are directories +# for which memory filesystems will be created and filled, +# and T is one of the "template" directories below: +# +# base universal base, typically a replica of the original root; +# default secondary universal base, typically overriding some +# of the files in the original root; +# ${ipba} where ${ipba} is the assigned broadcast IP address +# bcast/${ipba} same as above +# ${class} where ${class} is a list of directories supplied by +# bootp/dhcp through the T134 option. +# ${ipba} and ${class} are typically used to configure features +# for group of diskless clients, or even individual features; +# ${ip} where ${ip} is the machine's assigned IP address, typically +# used to set host-specific features; +# ip/${ip} same as above +# +# Template directories are scanned in the order they are listed above, +# with each successive directory overriding (merged into) the previous one; +# non-existing directories are ignored. The subdirectory forms exist to +# help keep the top level /conf manageable in large installations. +# +# The existence of a directory /conf/T/M causes this script to create a +# memory filesystem mounted as /M on the client. +# +# Some files in /conf have special meaning, namely: +# +# Filename Action +# ---------------------------------------------------------------- +# /conf/T/M/remount +# The contents of the file is a mount command. E.g. if +# /conf/1.2.3.4/foo/remount contains "mount -o ro /dev/ad0s3", +# then /dev/ad0s3 will be mounted on /conf/1.2.3.4/foo/ +# +# /conf/T/M/remount_optional +# If this file exists, then failure to execute the mount +# command contained in /conf/T/M/remount is non-fatal. +# +# /conf/T/M/remount_subdir +# If this file exists, then the behaviour of /conf/T/M/remount +# changes as follows: +# 1. /conf/T/M/remount is invoked to mount the root of the +# filesystem where the configuration data exists on a +# temporary mountpoint. +# 2. /conf/T/M/remount_subdir is then invoked to mount a +# *subdirectory* of the filesystem mounted by +# /conf/T/M/remount on /conf/T/M/. +# +# /conf/T/M/diskless_remount +# The contents of the file points to an NFS filesystem, +# possibly followed by mount_nfs options. If the server name +# is omitted, the script will prepend the root path used when +# booting. E.g. if you booted from foo.com:/path/to/root, +# an entry for /conf/base/etc/diskless_remount could be any of +# foo.com:/path/to/root/etc +# /etc -o ro +# Because mount_nfs understands ".." in paths, it is +# possible to mount from locations above the NFS root with +# paths such as "/../../etc". +# +# /conf/T/M/md_size +# The contents of the file specifies the size of the memory +# filesystem to be created, in 512 byte blocks. +# The default size is 10240 blocks (5MB). E.g. if +# /conf/base/etc/md_size contains "30000" then a 15MB MFS +# will be created. In case of multiple entries for the same +# directory M, the last one in the scanning order is used. +# NOTE: If you only need to create a memory filesystem but not +# initialize it from a template, it is preferable to specify +# it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0" +# +# /conf/T/SUBDIR.cpio.gz +# The file is cpio'd into /SUBDIR (and a memory filesystem is +# created for /SUBDIR if necessary). The presence of this file +# prevents the copy from /conf/T/SUBDIR/ +# +# /conf/T/M/extract +# This is alternative to SUBDIR.cpio.gz and remount. +# Similar to remount case, a memory filesystem is created +# for /M and initialized from a template but no mounting +# performed. Instead, this file is run passing /M as single +# argument. It is expected to extract template override to /M +# using auxiliary storage found in some embedded systems +# having NVRAM too small to hold mountable file system. +# +# /conf/T/SUBDIR.remove +# The list of paths contained in the file are rm -rf'd +# relative to /SUBDIR. +# +# /conf/diskless_remount +# Similar to /conf/T/M/diskless_remount above, but allows +# all of /conf to be remounted. This can be used to allow +# multiple roots to share the same /conf. +# +# +# You will almost universally want to create the following files under /conf +# +# File Content +# ---------------------------- ---------------------------------- +# /conf/base/etc/md_size size of /etc filesystem +# /conf/base/etc/diskless_remount "/etc" +# /conf/default/etc/rc.conf generic diskless config parameters +# /conf/default/etc/fstab generic diskless fstab e.g. like this +# +# foo:/root_part / nfs ro 0 0 +# foo:/usr_part /usr nfs ro 0 0 +# foo:/home_part /home nfs rw 0 0 +# md /tmp mfs -s=30m,rw 0 0 +# md /var mfs -s=30m,rw 0 0 +# proc /proc procfs rw 0 0 +# +# plus, possibly, overrides for password files etc. +# +# NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g. +# as entries in the fstab as above. +# Those filesystems should not be specified in /conf. +# +# (end of documentation, now get to the real code) + +dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` + +# DEBUGGING +# log something on stdout if verbose. +o_verbose=0 # set to 1 or 2 if you want more debugging +log() { + [ ${o_verbose} -gt 0 ] && echo "*** $* ***" + [ ${o_verbose} -gt 1 ] && read -p "=== Press enter to continue" foo +} + +# chkerr: +# +# Routine to check for error +# +# checks error code and drops into shell on failure. +# if shell exits, terminates script as well as /etc/rc. +# if remount_optional exists under the mountpoint, skip this check. +# +chkerr() { + lastitem () ( n=$(($# - 1)) ; shift $n ; echo $1 ) + mountpoint="$(lastitem $2)" + if [ -r $mountpoint/remount_optional ]; then + echo "$2 failed: ignoring due to remount_optional" + return + fi + case $1 in + 0) + ;; + *) + echo "$2 failed: dropping into /bin/sh" + /bin/sh + # RESUME + ;; + esac +} + +# The list of filesystems to umount after the copy +to_umount="" + +handle_remount() { # $1 = mount point + local nfspt mountopts b + b=$1 + log handle_remount $1 + [ -d $b -a -f $b/diskless_remount ] || return + read nfspt mountopts < $b/diskless_remount + log "nfspt ${nfspt} mountopts ${mountopts}" + # prepend the nfs root if not present + [ `expr "$nfspt" : '\(.\)'` = "/" ] && nfspt="${nfsroot}${nfspt}" + mount_nfs $mountopts $nfspt $b + chkerr $? "mount_nfs $nfspt $b" + to_umount="$b ${to_umount}" +} + +# Create a generic memory disk. +# The 'auto' parameter will attempt to use tmpfs(4), falls back to md(4). +# $1 is size in 512-byte sectors, $2 is the mount point. +mount_md() { + if [ ${o_verbose} -gt 0 ] ; then + /sbin/mdmfs -XL -S -s $1 auto $2 + else + /sbin/mdmfs -S -s $1 auto $2 + fi +} + +# Create the memory filesystem if it has not already been created +# +create_md() { + [ "x`eval echo \\$md_created_$1`" = "x" ] || return # only once + if [ "x`eval echo \\$md_size_$1`" = "x" ]; then + md_size=10240 + else + md_size=`eval echo \\$md_size_$1` + fi + log create_md $1 with size $md_size + mount_md $md_size /$1 + /bin/chmod 755 /$1 + eval md_created_$1=created +} + +# DEBUGGING +# +# set -v + +# Figure out our interface and IP. +# +bootp_ifc="" +bootp_ipa="" +bootp_ipbca="" +class="" +if [ ${dlv:=0} -ne 0 ] ; then + iflist=`ifconfig -l` + for i in ${iflist} ; do + set -- `ifconfig ${i}` + while [ $# -ge 1 ] ; do + if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then + bootp_ifc=${i} ; bootp_ipa=${2} ; shift + fi + if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then + bootp_ipbca=$2; shift + fi + shift + done + if [ "${bootp_ifc}" != "" ] ; then + break + fi + done + # Get the values passed with the T134 bootp cookie. + class="`/sbin/sysctl -qn kern.bootp_cookie`" + + echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}" +fi + +log Figure out our NFS root path +# +set -- `mount -t nfs` +while [ $# -ge 1 ] ; do + if [ "$2" = "on" -a "$3" = "/" ]; then + nfsroot="$1" + break + fi + shift +done + +# The list of directories with template files +templates="base default" +if [ -n "${bootp_ipbca}" ]; then + templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}" +fi +if [ -n "${class}" ]; then + templates="${templates} ${class}" +fi +if [ -n "${bootp_ipa}" ]; then + templates="${templates} ${bootp_ipa} ip/${bootp_ipa}" +fi + +# If /conf/diskless_remount exists, remount all of /conf. +handle_remount /conf + +# 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. +# If the diskless_remount file contains a string beginning with a +# '/' it is assumed that the local nfsroot should be prepended to +# it before attempting to the remount. This allows the root to be +# relocated without needing to change the remount files. +# +log "templates are ${templates}" +for i in ${templates} ; do + for j in /conf/$i/* ; do + [ -d $j ] || continue + + # memory filesystem size specification + subdir=${j##*/} + [ -f $j/md_size ] && eval md_size_$subdir=`cat $j/md_size` + + # remount. Beware, the command is in the file itself! + if [ -f $j/remount ]; then + if [ -f $j/remount_subdir ]; then + k="/conf.tmp/$i/$subdir" + [ -d $k ] || continue + + # Mount the filesystem root where the config data is + # on the temporary mount point. + nfspt=`/bin/cat $j/remount` + $nfspt $k + chkerr $? "$nfspt $k" + + # Now use a nullfs mount to get the data where we + # really want to see it. + remount_subdir=`/bin/cat $j/remount_subdir` + remount_subdir_cmd="mount -t nullfs $k/$remount_subdir" + + $remount_subdir_cmd $j + chkerr $? "$remount_subdir_cmd $j" + + # XXX check order -- we must force $k to be unmounted + # after j, as j depends on k. + to_umount="$j $k ${to_umount}" + else + nfspt=`/bin/cat $j/remount` + $nfspt $j + chkerr $? "$nfspt $j" + to_umount="$j ${to_umount}" # XXX hope it is really a mount! + fi + fi + + # NFS remount + handle_remount $j + done +done + +# - Create all required MFS filesystems and populate them from +# our templates. Support both a direct template and a dir.cpio.gz +# archive. Support for auxiliary NVRAM. Support dir.remove files containing +# a list of relative paths to remove. +# +# The dir.cpio.gz form is there to make the copy process more efficient, +# so if the cpio archive is present, it prevents the files from dir/ +# from being copied. + +PATH=${PATH}:/rescue + +for i in ${templates} ; do + for j in /conf/$i/* ; do + subdir=${j##*/} + if [ -d $j -a ! -f $j.cpio.gz ]; 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 / ; tar -xpf $j) + fi + done + for j in /conf/$i/*/extract ; do + if [ -x $j ]; then + subdir=${j%*/extract} + subdir=${subdir##*/} + create_md $subdir + echo "Loading /$subdir using auxiliary command $j" + $j /$subdir + 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 $j`) + fi + done +done + +# umount partitions used to fill the memory filesystems +[ -n "${to_umount}" ] && umount $to_umount |