3 # Copyright (c) 1999 Matt Dillon
6 # Redistribution and use in source and binary forms, with or without
7 # modification, are permitted provided that the following conditions
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.
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
28 # On entry to this script the entire system consists of a read-only root
29 # mounted via NFS. The kernel has run BOOTP and configured an interface
30 # (otherwise it would not have been able to mount the NFS root!)
32 # We use the contents of /conf to create and populate memory filesystems
33 # that are mounted on top of this root to implement the writable
34 # (and host-specific) parts of the root filesystem, and other volatile
37 # The hierarchy in /conf has the form /conf/T/M/ where M are directories
38 # for which memory filesystems will be created and filled,
39 # and T is one of the "template" directories below:
41 # base universal base, typically a replica of the original root;
42 # default secondary universal base, typically overriding some
43 # of the files in the original root;
44 # ${ipba} where ${ipba} is the assigned broadcast IP address
45 # bcast/${ipba} same as above
46 # ${class} where ${class} is a list of directories supplied by
47 # bootp/dhcp through the T134 option.
48 # ${ipba} and ${class} are typically used to configure features
49 # for group of diskless clients, or even individual features;
50 # ${ip} where ${ip} is the machine's assigned IP address, typically
51 # used to set host-specific features;
52 # ip/${ip} same as above
54 # Template directories are scanned in the order they are listed above,
55 # with each successive directory overriding (merged into) the previous one;
56 # non-existing directories are ignored. The subdirectory forms exist to
57 # help keep the top level /conf manageable in large installations.
59 # The existence of a directory /conf/T/M causes this script to create a
60 # memory filesystem mounted as /M on the client.
62 # Some files in /conf have special meaning, namely:
65 # ----------------------------------------------------------------
67 # The contents of the file is a mount command. E.g. if
68 # /conf/1.2.3.4/foo/remount contains "mount -o ro /dev/ad0s3",
69 # then /dev/ad0s3 will be mounted on /conf/1.2.3.4/foo/
71 # /conf/T/M/remount_optional
72 # If this file exists, then failure to execute the mount
73 # command contained in /conf/T/M/remount is non-fatal.
75 # /conf/T/M/remount_subdir
76 # If this file exists, then the behaviour of /conf/T/M/remount
78 # 1. /conf/T/M/remount is invoked to mount the root of the
79 # filesystem where the configuration data exists on a
80 # temporary mountpoint.
81 # 2. /conf/T/M/remount_subdir is then invoked to mount a
82 # *subdirectory* of the filesystem mounted by
83 # /conf/T/M/remount on /conf/T/M/.
85 # /conf/T/M/diskless_remount
86 # The contents of the file points to an NFS filesystem,
87 # possibly followed by mount_nfs options. If the server name
88 # is omitted, the script will prepend the root path used when
89 # booting. E.g. if you booted from foo.com:/path/to/root,
90 # an entry for /conf/base/etc/diskless_remount could be any of
91 # foo.com:/path/to/root/etc
93 # Because mount_nfs understands ".." in paths, it is
94 # possible to mount from locations above the NFS root with
95 # paths such as "/../../etc".
98 # The contents of the file specifies the size of the memory
99 # filesystem to be created, in 512 byte blocks.
100 # The default size is 10240 blocks (5MB). E.g. if
101 # /conf/base/etc/md_size contains "30000" then a 15MB MFS
102 # will be created. In case of multiple entries for the same
103 # directory M, the last one in the scanning order is used.
104 # NOTE: If you only need to create a memory filesystem but not
105 # initialize it from a template, it is preferable to specify
106 # it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0"
108 # /conf/T/SUBDIR.cpio.gz
109 # The file is cpio'd into /SUBDIR (and a memory filesystem is
110 # created for /SUBDIR if necessary). The presence of this file
111 # prevents the copy from /conf/T/SUBDIR/
114 # This is alternative to SUBDIR.cpio.gz and remount.
115 # Similar to remount case, a memory filesystem is created
116 # for /M and initialized from a template but no mounting
117 # performed. Instead, this file is run passing /M as single
118 # argument. It is expected to extract template override to /M
119 # using auxiliary storage found in some embedded systems
120 # having NVRAM too small to hold mountable file system.
122 # /conf/T/SUBDIR.remove
123 # The list of paths contained in the file are rm -rf'd
124 # relative to /SUBDIR.
126 # /conf/diskless_remount
127 # Similar to /conf/T/M/diskless_remount above, but allows
128 # all of /conf to be remounted. This can be used to allow
129 # multiple roots to share the same /conf.
132 # You will almost universally want to create the following files under /conf
135 # ---------------------------- ----------------------------------
136 # /conf/base/etc/md_size size of /etc filesystem
137 # /conf/base/etc/diskless_remount "/etc"
138 # /conf/default/etc/rc.conf generic diskless config parameters
139 # /conf/default/etc/fstab generic diskless fstab e.g. like this
141 # foo:/root_part / nfs ro 0 0
142 # foo:/usr_part /usr nfs ro 0 0
143 # foo:/home_part /home nfs rw 0 0
144 # md /tmp mfs -s=30m,rw 0 0
145 # md /var mfs -s=30m,rw 0 0
146 # proc /proc procfs rw 0 0
148 # plus, possibly, overrides for password files etc.
150 # NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g.
151 # as entries in the fstab as above.
152 # Those filesystems should not be specified in /conf.
154 # (end of documentation, now get to the real code)
156 dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null`
159 # log something on stdout if verbose.
160 o_verbose=0 # set to 1 or 2 if you want more debugging
162 [ ${o_verbose} -gt 0 ] && echo "*** $* ***"
163 [ ${o_verbose} -gt 1 ] && read -p "=== Press enter to continue" foo
168 # Routine to check for error
170 # checks error code and drops into shell on failure.
171 # if shell exits, terminates script as well as /etc/rc.
172 # if remount_optional exists under the mountpoint, skip this check.
175 lastitem () ( n=$(($# - 1)) ; shift $n ; echo $1 )
176 mountpoint="$(lastitem $2)"
177 [ -r $mountpoint/remount_optional ] && ( echo "$2 failed: ignoring due to remount_optional" ; return )
182 echo "$2 failed: dropping into /bin/sh"
189 # The list of filesystems to umount after the copy
192 handle_remount() { # $1 = mount point
193 local nfspt mountopts b
195 log handle_remount $1
196 [ -d $b -a -f $b/diskless_remount ] || return
197 read nfspt mountopts < $b/diskless_remount
198 log "nfspt ${nfspt} mountopts ${mountopts}"
199 # prepend the nfs root if not present
200 [ `expr "$nfspt" : '\(.\)'` = "/" ] && nfspt="${nfsroot}${nfspt}"
201 mount_nfs $mountopts $nfspt $b
202 chkerr $? "mount_nfs $nfspt $b"
203 to_umount="$b ${to_umount}"
206 # Create a generic memory disk.
207 # The 'auto' parameter will attempt to use tmpfs(5), falls back to md(4).
208 # $1 is size in 512-byte sectors, $2 is the mount point.
210 if [ ${o_verbose} -gt 0 ] ; then
211 /sbin/mdmfs -XL -s $1 auto $2
213 /sbin/mdmfs -s $1 auto $2
217 # Create the memory filesystem if it has not already been created
220 [ "x`eval echo \\$md_created_$1`" = "x" ] || return # only once
221 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then
224 md_size=`eval echo \\$md_size_$1`
226 log create_md $1 with size $md_size
227 mount_md $md_size /$1
229 eval md_created_$1=created
236 # Figure out our interface and IP.
242 if [ ${dlv:=0} -ne 0 ] ; then
244 for i in ${iflist} ; do
245 set -- `ifconfig ${i}`
246 while [ $# -ge 1 ] ; do
247 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then
248 bootp_ifc=${i} ; bootp_ipa=${2} ; shift
250 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then
251 bootp_ipbca=$2; shift
255 if [ "${bootp_ifc}" != "" ] ; then
259 # Get the values passed with the T134 bootp cookie.
260 class="`/sbin/sysctl -qn kern.bootp_cookie`"
262 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca} ${class}"
265 log Figure out our NFS root path
267 set -- `mount -t nfs`
268 while [ $# -ge 1 ] ; do
269 if [ "$2" = "on" -a "$3" = "/" ]; then
276 # The list of directories with template files
277 templates="base default"
278 if [ -n "${bootp_ipbca}" ]; then
279 templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}"
281 if [ -n "${class}" ]; then
282 templates="${templates} ${class}"
284 if [ -n "${bootp_ipa}" ]; then
285 templates="${templates} ${bootp_ipa} ip/${bootp_ipa}"
288 # If /conf/diskless_remount exists, remount all of /conf.
291 # Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
292 # and /conf/${bootp_ipa}. For each subdirectory found within these
295 # - calculate memory filesystem sizes. If the subdirectory (prior to
296 # NFS remounting) contains the file 'md_size', the contents specified
297 # in 512 byte sectors will be used to size the memory filesystem. Otherwise
298 # 8192 sectors (4MB) is used.
300 # - handle NFS remounts. If the subdirectory contains the file
301 # diskless_remount, the contents of the file is NFS mounted over
302 # the directory. For example /conf/base/etc/diskless_remount
303 # might contain 'myserver:/etc'. NFS remounts allow you to avoid
304 # having to dup your system directories in /conf. Your server must
305 # be sure to export those filesystems -alldirs, however.
306 # If the diskless_remount file contains a string beginning with a
307 # '/' it is assumed that the local nfsroot should be prepended to
308 # it before attempting to the remount. This allows the root to be
309 # relocated without needing to change the remount files.
311 log "templates are ${templates}"
312 for i in ${templates} ; do
313 for j in /conf/$i/* ; do
314 [ -d $j ] || continue
316 # memory filesystem size specification
318 [ -f $j/md_size ] && eval md_size_$subdir=`cat $j/md_size`
320 # remount. Beware, the command is in the file itself!
321 if [ -f $j/remount ]; then
322 if [ -f $j/remount_subdir ]; then
323 k="/conf.tmp/$i/$subdir"
324 [ -d $k ] || continue
326 # Mount the filesystem root where the config data is
327 # on the temporary mount point.
328 nfspt=`/bin/cat $j/remount`
330 chkerr $? "$nfspt $k"
332 # Now use a nullfs mount to get the data where we
333 # really want to see it.
334 remount_subdir=`/bin/cat $j/remount_subdir`
335 remount_subdir_cmd="mount -t nullfs $k/$remount_subdir"
337 $remount_subdir_cmd $j
338 chkerr $? "$remount_subdir_cmd $j"
340 # XXX check order -- we must force $k to be unmounted
341 # after j, as j depends on k.
342 to_umount="$j $k ${to_umount}"
344 nfspt=`/bin/cat $j/remount`
346 chkerr $? "$nfspt $j"
347 to_umount="$j ${to_umount}" # XXX hope it is really a mount!
356 # - Create all required MFS filesystems and populate them from
357 # our templates. Support both a direct template and a dir.cpio.gz
358 # archive. Support for auxiliary NVRAM. Support dir.remove files containing
359 # a list of relative paths to remove.
361 # The dir.cpio.gz form is there to make the copy process more efficient,
362 # so if the cpio archive is present, it prevents the files from dir/
367 for i in ${templates} ; do
368 for j in /conf/$i/* ; do
370 if [ -d $j -a ! -f $j.cpio.gz ]; then
375 for j in /conf/$i/*.cpio.gz ; do
376 subdir=${j%*.cpio.gz}
380 echo "Loading /$subdir from cpio archive $j"
384 for j in /conf/$i/*/extract ; do
386 subdir=${j%*/extract}
389 echo "Loading /$subdir using auxiliary command $j"
393 for j in /conf/$i/*.remove ; do
397 # doubly sure it is a memory disk before rm -rf'ing
399 (cd /$subdir; rm -rf `/bin/cat $j`)
404 # umount partitions used to fill the memory filesystems
405 [ -n "${to_umount}" ] && umount $to_umount