dracut/dracut-functions

#!/bin/bash
#
# functions used by dracut and other tools.
#
# Copyright 2005-2009 Red Hat, Inc.  All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

IF_RTLD=""
IF_dynamic=""

# Generic substring function.  If $2 is in $1, return 0.
strstr() { [[ $1 =~ $2 ]]; }

# Create all subdirectories for given path without creating the last element.
# $1 = path
mksubdirs() { mkdir -p ${1%/*}; }

# Version comparision function.  Assumes Linux style version scheme.
# $1 = version a
# $2 = comparision op (gt, ge, eq, le, lt, ne)
# $3 = version b
vercmp() {
    local n1=(${1//./ }) op=$2 n2=(${3//./ }) i res

    for ((i=0; ; i++))
    do
        if [[ ! ${n1[i]}${n2[i]} ]]; then res=0
        elif ((${n1[i]:-0} > ${n2[i]:-0})); then res=1
        elif ((${n1[i]:-0} < ${n2[i]:-0})); then res=2
        else continue
        fi
        break
    done

    case $op in
        gt) ((res == 1));;
        ge) ((res != 2));;
        eq) ((res == 0));;
        le) ((res != 1));;
        lt) ((res == 2));;
        ne) ((res != 0));;
    esac
}

# Log initrd creation.
if ! [[ $dracutlogfile ]]; then
    [[ $dracutbasedir = /usr/share/dracut ]] && \
	dracutlogfile=/var/log/dracut.log || \
	dracutlogfile=/tmp/dracut.log
#    [[ -w $dracutlogfile ]] || dracutlogfile=/tmp/dracut.log
    if [[ -w $dracutlogfile ]]; then
        >"$dracutlogfile"
    fi
fi

dwarning() {
    echo "W: $@" >&2
    [[ -w $dracutlogfile ]] && echo "W: $@" >>"$dracutlogfile"
}

dinfo() {
    [[ $beverbose ]] && echo "I: $@" >&2
    [[ -w $dracutlogfile ]] && echo "I: $@" >>"$dracutlogfile"
}

derror() {
    echo "E: $@" >&2
    [[ -w $dracutlogfile ]] && echo "E: $@" >>"$dracutlogfile"
}

# Function prints global variables in format name=value line by line.
# $@ = list of global variables' name
print_vars() {
    local var value

    for var in $@
    do
        value=$(eval echo \$$var)
        [[ ${value} ]] && echo "${var}=\"${value}\""
    done
}

get_fs_env() {
    [[ $1 ]] || return
    eval $(udevadm info --query=env --name=$1|egrep 'ID_FS_(TYPE|UUID)=')
    [[ $ID_FS_TYPE ]] && return

    if [[ -x /lib/udev/vol_id ]]; then
	eval $(/lib/udev/vol_id --export $1)
    elif find_binary blkid >/dev/null; then
	eval $(blkid -o udev $1)
    else
	return 1
    fi
}

get_fs_type() (
    [[ $1 ]] || return
    if [[ $1 != ${1#/dev/block/nfs:} ]] \
	|| [[ $1 != ${1#/dev/block/nfs3:} ]] \
	|| [[ $1 != ${1#/dev/block/nfs4:} ]]; then
	echo "nfs"
	return
    fi
    get_fs_env $1 || return
    echo $ID_FS_TYPE
)

get_fs_uuid() (
    get_fs_env $1 || return
    echo $ID_FS_UUID
)

# finds the major:minor of the block device backing the root filesystem.
find_block_device() {
    local x mpt majmin dev fs misc maj min
    if [[ $use_fstab != yes ]]; then	
	while read x x majmin x mpt x x fs misc; do
            [[ $fs = nfs ]] && { echo $dev; return 0;}
            [[ $fs = nfs3 ]] && { echo $dev; return 0;}
            [[ $fs = nfs4 ]] && { echo $dev; return 0;}
	    if [[ $mpt = $1 ]] && [[ ${majmin#0:} = $majmin ]]; then
		echo $majmin; 
		return 0 # we have a winner!
	    fi
	done < /proc/self/mountinfo       
    fi
    # fall back to /etc/fstab    
    while read dev mpt fs misc; do
	if [[ $mpt = $1 ]]; then
            [[ $fs = nfs ]] && { echo $dev; return 0;}
            [[ $fs = nfs3 ]] && { echo $dev; return 0;}
            [[ $fs = nfs4 ]] && { echo $dev; return 0;}
            [[ $dev != ${dev#UUID=} ]] && dev=/dev/disk/by-uuid/${dev#UUID=}
            [[ $dev != ${dev#LABEL=} ]] && dev=/dev/disk/by-label/${dev#LABEL=}
	    [[ -b $dev ]] || return 1 # oops, not a block device.
	    ls -nLl "$dev" | { 
		read x x x x maj min x;
		maj=${maj//,/}; 
		echo $maj:$min; 
	    } && return 0
	fi
    done < /etc/fstab
    return 1;
}

find_root_block_device() { find_block_device /; }

# Walk all the slave relationships for a given block device.
# Stop when our helper function returns success
# $1 = function to call on every found block device
# $2 = block device in major:minor format
check_block_and_slaves() {    
    local x 
    [[ -b /dev/block/$2 ]] || return 1 # Not a block device? So sorry.
    "$1" $2 && return
    check_vol_slaves "$@" && return 0
    if [[ -f /sys/dev/block/$2/../dev ]]; then
	check_block_and_slaves $1 $(cat "/sys/dev/block/$2/../dev") &&  return 0
    fi
    [[ -d /sys/dev/block/$2/slaves ]] || return 1
    for x in /sys/dev/block/$2/slaves/*/dev; do
        [[ -f $x ]] || continue
	check_block_and_slaves $1 $(cat "$x") &&  return 0
    done
    return 1
}

get_numeric_dev() {
    ls -lH "$1" | { read a b c d maj min rest; printf "%d:%d" ${maj%%,} $min;}
}

# ugly workaround for the lvm design
# There is no volume group device,
# so, there are no slave devices for volume groups.
# Logical volumes only have the slave devices they really live on,
# but you cannot create the logical volume without the volume group.
# And the volume group might be bigger than the devices the LV needs.
check_vol_slaves() {
    for i in /dev/mapper/*; do 
	lv=$(get_numeric_dev $i)
	if [[ $lv = $2 ]]; then
	    vg=$(lvm lvs --noheadings -o vg_name $i 2>/dev/null)
	    # strip space
	    vg=$(echo $vg)
	    if [[ $vg ]]; then
		for pv in $(lvm vgs --noheadings -o pv_name "$vg" 2>/dev/null); \
		    do
 		    check_block_and_slaves $1 $(get_numeric_dev $pv) \
			&&  return 0
		done
	    fi
	fi
    done
    return 1
}

# Install a directory, keeping symlinks as on the original system.
# Example: if /lib64 points to /lib on the host, "inst_dir /lib/file"
# will create ${initdir}/lib64, ${initdir}/lib64/file,
# and a symlink ${initdir}/lib -> lib64.
inst_dir() {
    local dir="$1"
    [[ -e ${initdir}$dir ]] && return 0

    # iterate over parent directories
    local file=""
    local IFS="/"
    for part in $dir; do
        [[ $part ]] || continue
        file="$file/$part"
        [[ -e ${initdir}$file ]] && continue

        if [[ -L $file ]]; then
            # create link as the original
            local target=$(readlink "$file")
            ln -sfn "$target" "${initdir}$file" || return 1
            # resolve relative path and recursively install destionation
            [[ $target = ${target##*/} ]] && target="${file%/*}/$target"
            inst_dir "$target"
        else
            # create directory
            mkdir -p "${initdir}$file" || return 1
        fi
    done
}

# $1 = file to copy to ramdisk
# $2 (optional) Name for the file on the ramdisk
# Location of the image dir is assumed to be $initdir
# We never overwrite the target if it exists.
inst_simple() {
    local src target
    [[ -f $1 ]] || return 1
    src=$1 target="${2:-$1}"
    if ! [[ -d ${initdir}$target ]]; then
        [[ -e ${initdir}$target ]] && return 0
        inst_dir "${target%/*}"
    fi
    dinfo "Installing $src" 
    cp -pfL "$src" "${initdir}$target"
}

# find symlinks linked to given library file
# $1 = library file
# Function searches for symlinks by stripping version numbers appended to
# library filename, checks if it points to the same target and finally
# prints the list of symlinks to stdout.
#
# Example:
# rev_lib_symlinks libfoo.so.8.1
# output: libfoo.so.8 libfoo.so
# (Only if libfoo.so.8 and libfoo.so exists on host system.)
rev_lib_symlinks() {
    [[ ! $1 ]] && return 0

    local fn="$1" orig="$(readlink -f "$1")" links=''

    [[ ${fn} =~ .*\.so\..* ]] || return 1

    until [[ ${fn##*.} == so ]]; do
        fn="${fn%.*}"
        [[ -L ${fn} && $(readlink -f "${fn}") == ${orig} ]] && links+=" ${fn}"
    done

    echo ${links}
}

# Same as above, but specialized to handle dynamic libraries.
# It handles making symlinks according to how the original library
# is referenced.
inst_library() {
    local src=$1 dest=${2:-$1} lib reallib symlink
    [[ -e $initdir$dest ]] && return 0
    if [[ -L $src ]]; then
	reallib=$(readlink -f "$src")
	lib=${src##*/}
	inst_simple "$reallib" "$reallib"
	inst_dir "${dest%/*}"
	(cd "${initdir}${dest%/*}" && ln -s "$reallib" "$lib")
    else
	inst_simple "$src" "$dest"
    fi

    # Create additional symlinks.  See rev_symlinks description.
    for symlink in $(rev_lib_symlinks $src) $(rev_lib_symlinks $reallib); do
        [[ ! -e $initdir$symlink ]] && {
            dinfo "Creating extra symlink: $symlink"
            inst_symlink $symlink
        }
    done
}

# find a binary.  If we were not passed the full path directly,
# search in the usual places to find the binary.
find_binary() {
    local binpath="/bin /sbin /usr/bin /usr/sbin" p
    [[ -z ${1##/*} && -x $1 ]] && { echo $1; return 0; } 
    for p in $binpath; do
	[[ -x $p/$1 ]] && { echo "$p/$1"; return 0; }
    done
    return 1
}

# Same as above, but specialized to install binary executables.
# Install binary executable, and all shared library dependencies, if any.
inst_binary() {
    local bin target
    bin=$(find_binary "$1") || return 1
    target=${2:-$bin}
    inst_symlink $bin $target && return 0
    local LDSO NAME IO FILE ADDR I1 n f TLIBDIR
    [[ -e $initdir$target ]] && return 0
    # I love bash!
    LC_ALL=C ldd $bin 2>/dev/null | while read line; do
	[[ $line = 'not a dynamic executable' ]] && return 1
	if [[ $line =~ not\ found ]]; then
	    derror "Missing a shared library required by $bin."
	    derror "Run \"ldd $bin\" to find out what it is."
	    derror "dracut cannot create an initrd."
	    exit 1
	fi
	so_regex='([^ ]*/lib[^/]*/[^ ]*\.so[^ ]*)'
	[[ $line =~ $so_regex ]] || continue
	FILE=${BASH_REMATCH[1]}
	[[ -e ${initdir}$FILE ]] && continue
	# see if we are loading an optimized version of a shared lib.
	lib_regex='^(/lib[^/]*).*'
	if [[ $FILE =~ $lib_regex ]]; then
            TLIBDIR=${BASH_REMATCH[1]}
            BASE=${FILE##*/}
	    # prefer nosegneg libs, then unoptimized ones.
	    for f in "$TLIBDIR/i686/nosegneg" "$TLIBDIR"; do
		[[ -e $f/$BASE ]] || continue
		FILE=$f/$BASE
		break
	    done
	    inst_library "$FILE" "$TLIBDIR/$BASE"
            IF_dynamic=yes
	    continue
	fi
        inst_library "$FILE" 
    done
    inst_simple "$bin" "$target"
}

# same as above, except for shell scripts.
# If your shell script does not start with shebang, it is not a shell script.
inst_script() {
    [[ -f $1 ]] || return 1
    local line
    read -r -n 80 line <"$1"
    # If debug is set, clean unprintable chars to prevent messing up the term
    [[ $debug ]] && line=$(echo -n "$line" | tr -c -d '[:print:][:space:]')
    shebang_regex='(#! *)(/[^ ]+).*'
    [[ $line =~ $shebang_regex ]] || return 1
    inst "${BASH_REMATCH[2]}" && inst_simple "$@"
}

# same as above, but specialized for symlinks
inst_symlink() {
    local src=$1 target=$initdir${2:-$1} realsrc
    [[ -L $1 ]] || return 1
    [[ -L $target ]] && return 0
    realsrc=$(readlink -f "$src")
    [[ $realsrc = ${realsrc##*/} ]] && realsrc=${src%/*}/$realsrc
    inst "$realsrc" && ln -s "$realsrc" "$target"
}

# find a udev rule in the usual places.
find_rule() {
    [[ -f $1 ]] && { echo "$1"; return 0; }
    for r in . /lib/udev/rules.d /etc/udev/rules.d $dracutbasedir/rules.d; do
	[[ -f $r/$1 ]] && { echo "$r/$1"; return 0; }
    done
    return 1
}

# udev rules always get installed in the same place, so
# create a function to install them to make life simpler.
inst_rules() { 
    local target=/etc/udev/rules.d rule found

    inst_dir "/lib/udev/rules.d"
    inst_dir "$target"
    for rule in "$@"; do 
        found=$(find_rule "$rule") && \
            inst_simple "$found" "$target/${found##*/}" \
            || dinfo "Skipping udev rule: $rule"
    done
}

# general purpose installation function
# Same args as above.
inst() {
    case $# in
        1) ;;
        2) [[ ! $initdir && -d $2 ]] && export initdir=$2
           [[ $initdir = $2 ]] && set $1;;
        3) [[ -z $initdir ]] && export initdir=$2 
           set $1 $3;;
        *) derror "inst only takes 1 or 2 or 3 arguments"
           exit 1;;
    esac
    for x in inst_symlink inst_script inst_binary inst_simple; do
       $x "$@" && return 0
    done
    return 1
}

# install function specialized for hooks
# $1 = type of hook, $2 = hook priority (lower runs first), $3 = hook
# All hooks should be POSIX/SuS compliant, they will be sourced by init.
inst_hook() {
    if ! [[ -f $3 ]]; then
	derror "Cannot install a hook ($3) that does not exist."
	derror "Aborting initrd creation."
	exit 1
    elif ! strstr "$hookdirs" "$1"; then
	derror "No such hook type $1. Aborting initrd creation." 
	exit 1
    fi
    inst_simple "$3" "/${1}/${2}${3##*/}"
}

dracut_install() {
    if [[ $1 = '-o' ]]; then 
	local optional=yes
	shift
    fi
    while (($# > 0)); do
	if ! inst "$1" ; then
	    if [[ $optional = yes ]]; then
		dwarning "Skipping program $1 as it cannot be found and is flagged to be optional"
	    else
		derror "Failed to install $1"
		exit 1
            fi
	fi
	shift
    done
}

# install function decompressing the target and handling symlinks
# $@ = list of compressed (gz or bz2) files or symlinks pointing to such files
#
# Function install targets in the same paths inside overlay but decompressed
# and without extensions (.gz, .bz2).
inst_decompress() {
    local src dst realsrc realdst cmd

    for src in $@
    do
        case ${src} in
            *.gz) cmd='gzip -d' ;;
            *.bz2) cmd='bzip2 -d' ;;
            *) return 1 ;;
        esac

        if [[ -L ${src} ]]
        then
            realsrc="$(readlink -f ${src})" # symlink target with extension
            dst="${src%.*}" # symlink without extension
            realdst="${realsrc%.*}" # symlink target without extension
            mksubdirs "${initdir}/${src}"
            # Create symlink without extension to target without extension.
            ln -s "${realdst}" "${initdir}/${dst}"
        fi

        # If the source is symlink we operate on its target.
        [[ ${realsrc} ]] && src=${realsrc}
        inst ${src}
        # Decompress with chosen tool.  We assume that tool changes name e.g.
        # from 'name.gz' to 'name'.
        ${cmd} "${initdir}${src}"
    done
}

# It's similar to above, but if file is not compressed, performs standard
# install.
# $@ = list of files
inst_opt_decompress() {
    local src

    for src in $@
    do
        inst_decompress "${src}" || inst "${src}"
    done
}

check_module_deps() {
    local moddir dep ret
    # if we are already set to be loaded, we do not have to be checked again.
    strstr " $mods_to_load " " $1 " && return
    strstr " $omit_dracutmodules " " $1 " && return 1
    # turn a module name into a directory, if we can.
    moddir=$(echo ${dracutbasedir}/modules.d/??${1})
    [[ -d $moddir && -x $moddir/install ]] || return 1
    # if we do not have a check script, we are unconditionally included
    if [[ -x $moddir/check ]]; then
	"$moddir/check"
        ret=$?
	# a return value of 255 = load module only as a dependency.
	((ret==0||ret==255)) || return 1
	for dep in $("$moddir/check" -d); do
	    check_module_deps "$dep" && continue
	    dwarning "Dependency $mod failed."
	    return 1
	done
    fi
    mods_to_load+=" $1 "
}

should_source_module() {
    local dep
    local ret
    if [[ $kernel_only = yes ]]; then
        [[ -x $1/installkernel ]] && return 0
        return 1
    fi
    [[ -x $1/install || -x $1/installkernel ]] || return 1
    [[ -x $1/check ]] || return 0
    "$1/check" $hostonly || continue
    for dep in $("$1/check" -d); do
	check_module_deps "$dep" && continue
	dwarning "Cannot load dracut module \"$mod\", dependencies failed."
	return 1
    done
}

check_modules() {
    local modcheck;
    local mod;
    for moddir in "$dracutbasedir/modules.d"/[0-9][0-9]*; do
	local mod=${moddir##*/}; mod=${mod#[0-9][0-9]}
	# If we are already scheduled to be loaded, no need to check again.
	strstr " $mods_to_load " " $mod " && continue
	# This should never happen, but...
	[[ -d $moddir ]] || continue
        strstr " $omit_dracutmodules " " $mod " && continue

        if ! strstr " $dracutmodules $add_dracutmodules " " $mod "; then
            # module not in our list
	    if [[ $dracutmodules = all ]]; then
                # check, if we can install this module
	        should_source_module "$moddir" || continue
            else
                # skip this module
                continue
            fi
	else
	    if [ -x "$moddir/check" ] \
                && "$moddir/check" -d > /dev/null 2>&1; then
		check_module_deps "$mod" || {
		    dwarning "Cannot load dracut module \"$mod\", dependencies failed."
                    continue
                }
            fi
        fi

	mods_to_load+=" $mod "
    done

    modcheck=$add_dracutmodules
    [[ $dracutmodules != all ]] && modcheck="$m $dracutmodules"
    for mod in $modcheck; do
        strstr " $mods_to_load " " $mod " && continue
        strstr " $omit_dracutmodules " " $mod " && continue
        dwarning "Dracut module \"$mod\" cannot be found."
    done
}

# Install a single kernel module along with any firmware it may require.
# $1 = full path to kernel module to install
install_kmod_with_fw() {
    local modname=${1##*/} fwdir found
    modname=${modname%.ko*}
    inst_simple "$1" "/lib/modules/$kernel/${1##*/lib/modules/$kernel/}" || \
	return 0 # no need to go further if the module is already installed
    for fw in $(modinfo -k $kernel -F firmware $1 2>/dev/null); do
	found=''
	for fwdir in $fw_dir; do
	    if [[ -d $fwdir && -f $fwdir/$fw ]]; then
		inst_simple "$fwdir/$fw" "/lib/firmware/$fw"
		found=yes
	    fi
	done
	if [[ $found != yes ]]; then
	    dinfo "Possible missing firmware \"${fw}\" for kernel module \"${mod}.ko\""
	fi
    done
}

# Do something with all the dependencies of a kernel module.
# Note that kernel modules depend on themselves using the technique we use
# $1 = function to call for each dependency we find 
#      It will be passed the full path to the found kernel module 
# $2 = module to get dependencies for
# rest of args = arguments to modprobe
for_each_kmod_dep() {
    local func=$1 kmod=$2 cmd modpapth options
    shift 2
    modprobe "$@" --ignore-install --show-depends $kmod 2>/dev/null | \
	while read cmd modpath options; do
	    [[ $cmd = insmod ]] || continue
	    $func $modpath
    done
}

# filter kernel modules to install certain modules that meet specific
# requirements.
# $1 = function to call with module name to filter.
#      This function will be passed the full path to the module to test.
# The behaviour of this function can vary depending on whether $hostonly is set.
# If it is, we will only look at modules that are already in memory.
# If it is not, we will look at all kernel modules
# This function returns the full filenames of modules that match $1
filter_kernel_modules () (
    if ! [[ $hostonly ]]; then
	filtercmd='find "$srcmods/kernel/drivers" -name "*.ko" -o -name "*.ko.gz"'
    else
	filtercmd='cut -d " " -f 1 </proc/modules|xargs modinfo -F filename -k $kernel'
    fi
    for modname in $(eval $filtercmd); do
        case $modname in
            *.ko) "$1" "$modname" && echo "$modname";;
            *.ko.gz) gzip -dc "$modname" > $initdir/$$.ko
                     $1 $initdir/$$.ko && echo "$modname"
                     rm -f $initdir/$$.ko;;
        esac
    done
)

# install kernel modules along with all their dependencies.
instmods() {
    [[ $no_kernel = yes ]] && return
    local mod mpargs modpath modname cmd moddirname
    while (($# > 0)); do
	mod=${1%.ko*}
	case $mod in
	    =*) # This introduces 2 incompatible meanings for =* arguments
                # to instmods.  We need to decide which one to keep.
		if [[ $mod = =ata && -f $srcmods/modules.block ]] ; then 
		    instmods $mpargs $(egrep 'ata|ahci' "${srcmods}/modules.block")
		elif [ -f $srcmods/modules.${mod#=} ]; then
		    instmods $mpargs $(cat ${srcmods}/modules.${mod#=} )
		else
		    instmods $mpargs $(find "$srcmods" -path "*/${mod#=}/*")
		fi
		;;
	    --*) mod=${mod##*/}
                 mpargs+=" $mod";;
            i2o_scsi) shift; continue;; # Do not load this diagnostic-only module
	    *)  mod=${mod##*/}
                # if we are already installed, skip this module and go on
	        # to the next one.
	        [[ -f $initdir/$1 ]] && { shift; continue; }
		# If we are building a host-specific initramfs and this
		# module is not already loaded, move on to the next one.
		[[ $hostonly ]] && ! grep -qe "\<${mod//-/_}\>" /proc/modules && \
	        ! echo $add_drivers | grep -qe "\<${mod}\>" &&	{
		    shift; continue; 
		}

		# We use '-d' option in modprobe only if modules prefix path
		# differs from default '/'.  This allows us to use Dracut with
		# old version of modprobe which doesn't have '-d' option.
		moddirname=${srcmods%%/lib/modules/*}
		[[ -n ${moddirname} ]] && moddirname="-d ${moddirname}/"

		# ok, load the module, all its dependencies, and any firmware
		# it may require
		for_each_kmod_dep install_kmod_with_fw $mod \
		    --set-version $kernel ${moddirname}
		;;
	esac      
	shift
    done
} 

# vim:ts=8:sw=4:sts=4:et