#! /bin/sh
# Script to grab a given kernel version (stolen from Virtual Anton).
# Posted by Rusty Russell.
# Updates by Rusty Russell and Randy.Dunlap.
# Update 2006-10-26:
#	when an -mm 2.6.n-mmX patch is downloaded,
#	it is renamed to patch-2.6.n-mmX,
#	and then that file is applied as a patch.
# 2008-05-15:  add -next kernel patches;

barf()
{
    echo "$@" >&2
    exit 1
}

pr_exists()
{
	echo "$@ already exists" >&2
	exit 0
}

make_exec()
{
	wd=`/bin/pwd`
	###echo "INFO: CWD=$wd"
	dir=$1
	###echo "INFO: make_exec: dir=$dir"
	chmod +x $dir/scripts/*.sh $dir/scripts/*.pl
}

# Takes destination directory, and filename, tries each mirror.
get_file()
{
    get_file_dir=$1
    get_file_name=$2
    cwd=`/bin/pwd`
    ###echo "INFO: get_file: dir=$1; name=$2; CWD=$cwd" >&2

    # Patch there already?
    if [ -f "$get_file_dir"/"$(basename "$get_file_name")" ]; then
	echo " Already have patch: [$get_file_dir/$(basename "$get_file_name")]" >&2
	return 0
    fi

    for get_file_server in $MIRRORS; do
	echo Trying to get file from: $get_file_server...
	case $get_file_server in
	rsync://*) get_file_s=`echo $get_file_server | cut -c9-`;
		rsync $get_file_s/$get_file_name $get_file_dir && return 0
		;;
	http://*) get_file_s="$get_file_server";
		###echo "INFO: cd to: get_file_dir=$get_file_dir"
		cd $get_file_dir
		###echo "INFO: cd back to: $cwd"
		curl -O $get_file_s/$get_file_name && cd $cwd && return 0
		# Leaves a zero-len file on failure 8(
		###echo "INFO: cd back to: $cwd"
		cd $cwd
		rm -f $get_file_dir/`basename $get_file_name`
		;;
	local:*) get_file_s=`echo $get_file_server | cut -c9-`;
		scp -p $get_file_server/$get_file_name $get_file_dir && return 0
		;;
	esac
    done
    return 1
}

# Given vanity kernel name, major version, & previous/base version,
# produce pathname
vanity_source()
{
    ###echo "INFO: vanity_source: series:$1; major:$2; base:$3;" >&2
    case "$1" in
    *-ac*)
	echo people/alan/linux-$2/$3/patch-$1.bz2;;
    *-dj*)
	echo people/davej/patches/$2/$3/patch-$1.bz2;;
    *-mm*)
	echo people/akpm/patches/$2/$3/$1/$1.bz2;;
    *next-*)
	echo people/sfr/linux-next/patch-$3-next-$1.bz2;;
    *)
	barf "Unknown kernel series $1";;
    esac
}

# Given base name, new name and patch, do patch application.
apply_patch()
{
	base=$1
	ver=$2
	pfile=$3

	###echo "INFO: apply_patch: level: $level, base: $base; ver: $ver; pfile: $pfile" >&2
	cwd=`/bin/pwd`
	###echo "INFO: apply_patch: KDIR=$KDIR, CWD=$cwd"
	rm -rf $KDIR/.linux-$ver
	cp -al $KDIR/linux-$base $KDIR/.linux-$ver ||
		barf "Couldn't clone $base dir"
	bunzip2 -t $pfile || barf "Corrupt patch $pfile"
	bzcat $pfile | patch -bs -p1 -d $KDIR/.linux-$ver ||
		barf "Problem patching new kernel $ver"
	mv $KDIR/.linux-$ver $KDIR/linux-$ver
	###echo "INFO: made new $KDIR/linux-$ver" >&2
	if [ $level -eq 0 ]; then
		echo "rename /linux-$VERSION/ as needed....." >&2
	fi
	###echo "INFO: ready to rm $KDIR/linux-$base" >&2
	rm -rf $KDIR/linux-$base
}

# main:
# keep up with recursion level
level=0

if [ -r /etc/crucible.cfg ] && [ "$HOME" == "/root" ]; then
	source /etc/crucible.cfg
	RCFILE="$ETC_DIR/grab-kernel.rc"
else
	RCFILE="$HOME/.grabkernelrc"
fi

# set empty param strings
PATCHDIR=""
MIRRORS=""

DEFPATCHDIR=/usr/src/kernel-archive
DEFMIRRORS="http://www.kernel.org/pub/linux/kernel"

# get base defaults from $RCFILE
# Note:  using '~' instead of $HOME fails;
if [ -r $RCFILE ]; then
	#echo "debug: sourcing RCFILE=$RCFILE"
	source $RCFILE
else
	echo "Warning: no RCFILE=$RCFILE"
fi

if [ "$PATCHDIR" == "" ]; then
	PATCHDIR=$DEFPATCHDIR
fi
#echo "debug: using PATCHDIR=$PATCHDIR"

if [ "$MIRRORS" == "" ]; then
#	MIRRORS="rsync://rsync.kernel.org:/pub/linux/kernel http://www.kernel.org/pub/linux/kernel rsync://master.kernel.org:/pub/linux/kernel"
#	MIRRORS="rsync.planetmirror.com::ftp.kernel.org/pub/linux/kernel master.kernel.org:/pub/linux/kernel"
	MIRRORS=$DEFMIRRORS
fi
#echo "debug: using MIRRORS=$MIRRORS"

if [ $# -eq 3 ]; then
	level=$3
	###echo "INFO: level is: $level" >&2
else
if [ $# -ne 2 ]; then
    echo Usage: $0 version dest_kernel_dir >&2
    echo "  with other parameters in $RCFILE" >&2
    exit 1
fi
fi

VERSION=$1
KDIR=$2

if [ -d $KDIR/linux-$VERSION ]; then pr_exists "$KDIR/linux-$VERSION" ; fi

MAJOR=`echo $VERSION | cut -d. -f1-2`

echo Grabbing $VERSION
case "$VERSION" in
    # Bitkeeper snapshot
    *-bk*)
	if [ -d $KDIR/linux-$VERSION ]; then pr_exists "$KDIR/linux-$VERSION" ; fi

	PREVIOUS=`echo "$VERSION" | sed 's/-bk.*//'`
	$0 "$PREVIOUS" $KDIR $((level + 1)) ||
		barf "Couldn't get $PREVIOUS to build $VERSION"

	# Grab patch
	get_file $PATCHDIR v$MAJOR/snapshots/patch-$VERSION.bz2 ||
		barf "Couldn't get v$MAJOR/snapshots/patch-$VERSION.bz2"
	apply_patch $PREVIOUS $VERSION $PATCHDIR/patch-$VERSION.bz2
	;;

    # git snapshot
    *-git*)
	if [ -d $KDIR/linux-$VERSION ]; then pr_exists "$KDIR/linux-$VERSION" ; fi

	PREVIOUS=`echo "$VERSION" | sed 's/-git.*//'`
	$0 "$PREVIOUS" $KDIR $((level + 1)) ||
		barf "Couldn't get $PREVIOUS to build $VERSION"

	# Grab patch
	get_file $PATCHDIR v$MAJOR/snapshots/patch-$VERSION.bz2 ||
		barf "Couldn't get v$MAJOR/snapshots/patch-$VERSION.bz2"
	apply_patch $PREVIOUS $VERSION $PATCHDIR/patch-$VERSION.bz2
	;;

    # Various vanity patches
    *-mm[0-9]*|*-ac[0-9]*|*-dj[0-9]*)
	# First make sure we have base tree
	BASE_KERNEL=`echo "$VERSION" | sed -e 's/-[a-z][a-z][0-9]*$//'`
	$0 "$BASE_KERNEL" $KDIR	$((level + 1)) ||
		barf "Couldn't get $BASE_KERNEL to build $VERSION"
	VANITY=`vanity_source $VERSION $MAJOR $BASE_KERNEL`
	get_file $PATCHDIR $VANITY || barf "Couldn't fetch $VANITY"

	# rename 2.6.*-mm-* to patch-2.6.*-mm-*
	if [ -e $PATCHDIR/$VERSION.bz2 ]; then
		mv $PATCHDIR/$VERSION.bz2 $PATCHDIR/patch-$VERSION.bz2
	fi
	##apply_patch $BASE_KERNEL $VERSION $PATCHDIR/`basename $VANITY`
	apply_patch $BASE_KERNEL $VERSION $PATCHDIR/patch-$VERSION.bz2
	;;

    *next-*)
	# First make sure we have base tree
	echo "## -next- target VERSION=$VERSION ##"
	BASE_KERNEL=`echo "$VERSION" | sed -e 's/-[a-z][a-z][0-9]*$//'`
	echo "## -next- BASE_KERNEL=$BASE_KERNEL ##"
	##$0 "$BASE_KERNEL" $KDIR	$((level + 1)) ||
		##barf "Couldn't get $BASE_KERNEL to build $VERSION"
	VANITY=`vanity_source $VERSION $MAJOR $BASE_KERNEL`
	echo "## -next- VANITY=$VANITY ##"
	##get_file $PATCHDIR $VANITY || barf "Couldn't fetch $VANITY"

	####apply_patch $BASE_KERNEL $VERSION $PATCHDIR/`basename $VANITY`
	##apply_patch $BASE_KERNEL $VERSION $PATCHDIR/patch-$VERSION.bz2
	;;

    # *-pre* or *-rc*: This refers to the Linus or Marcelo pre-patches.
    *-pre*|*-rc*)
	# Linus or Marcelo pre-patch.
	if [ -d $KDIR/linux-$VERSION ]; then pr_exists "$KDIR/linux-$VERSION" ; fi

	PREVIOUS=`echo "$VERSION" | sed 's/-\(pre\|rc\).*//'`
	LAST_VER=`echo "$PREVIOUS" | cut -d. -f3`
	PREVIOUS=`echo "$PREVIOUS" | cut -d. -f1,2`.`expr $LAST_VER - 1 || true`
	$0 "$PREVIOUS" $KDIR $((level + 1)) ||
		barf "Couldn't get $PREVIOUS to build $VERSION"

	# Grab patch
	get_file $PATCHDIR v$MAJOR/testing/patch-$VERSION.bz2 ||
		get_file $PATCHDIR v$MAJOR/testing/old/patch-$VERSION.bz2 ||
		barf "Couldn't get v$MAJOR/testing/patch-$VERSION.bz2"
	apply_patch $PREVIOUS $VERSION $PATCHDIR/patch-$VERSION.bz2
	;;

    # Linus 2.6.0 test patch.
    2.6.0-test*)
	VER=`echo "$VERSION" | sed 's/.*test//'`
	PREVIOUS=2.6.0-test`expr $VER - 1 || true`

	if [ $PREVIOUS = 2.6.0-test0 ]; then
	    PREVIOUS=2.5.75
	fi

	$0 "$PREVIOUS" $KDIR $((level + 1)) ||
		barf "Couldn't get $PREVIOUS to build $VERSION"

	# Grab patch
	get_file $PATCHDIR v$MAJOR/patch-$VERSION.bz2 ||
		get_file $PATCHDIR v$MAJOR/old/patch-$VERSION.bz2 ||
		barf "Couldn't get v$MAJOR/patch-$VERSION.bz2"
	apply_patch $PREVIOUS $VERSION $PATCHDIR/patch-$VERSION.bz2
	;;

    2.6.0)
	PREVIOUS=2.6.0-test11

	$0 "$PREVIOUS" $KDIR $((level + 1)) ||
		barf "Couldn't get $PREVIOUS to build $VERSION"

	# Grab patch
	get_file $PATCHDIR v$MAJOR/patch-$VERSION.bz2 ||
		get_file $PATCHDIR v$MAJOR/old/patch-$VERSION.bz2 ||
		barf "Couldn't get v$MAJOR/patch-$VERSION.bz2"
	apply_patch $PREVIOUS $VERSION $PATCHDIR/patch-$VERSION.bz2
	;;

    # *.0: This refers to the base of the Linus kernels, fetched whole.
    *.0)
	# Linus' root of all trees.
	get_file $PATCHDIR v$MAJOR/linux-$VERSION.tar.bz2 ||
		barf "Couldn't get  v$MAJOR/linux-$VERSION.tar.bz2"
	bzcat $PATCHDIR/linux-$VERSION.tar.bz2 | (cd $KDIR && tar xf -) ||
		barf "Problem unpacking linux-$VERSION.tar.bz2"
	mv $KDIR/linux $KDIR/linux-$VERSION
	;;

    #   [1-9].*.*: This refers to the any other Linus kernel.
    [1-9].*.*[0-9])
	# Linus standard ?
	if [ -d $KDIR/linux-$VERSION ]; then pr_exists "$KDIR/linux-$VERSION" ; fi

	LAST_VER=`echo "$VERSION" | cut -d. -f3`
	PREVIOUS=`echo "$VERSION" | cut -d. -f1,2`.`expr $LAST_VER - 1 || true`
	###$0 "$PREVIOUS" $KDIR $((level + 1)) ||
	###	barf "Couldn't get $PREVIOUS to build $VERSION"

	# Grab tarball
	get_file $PATCHDIR v$MAJOR/linux-$VERSION.tar.bz2 ||
		barf "Couldn't get v$MAJOR/linux-$VERSION.tar.bz2"
	###trap "rm -rf $KDIR/linux-$VERSION" 0
	###apply_patch $PREVIOUS $VERSION $PATCHDIR/linux-$VERSION.tar.bz2
	###echo "INFO: cd to: KDIR=$KDIR"
	cd $KDIR && echo "untar in $KDIR....."
	tar xjf $PATCHDIR/linux-$VERSION.tar.bz2 ||
		barf "Problem with kernel tarball ($VERSION)"
	###echo "INFO: level: $level" >&2
	if [ $level -eq 0 ]; then
		echo "rename /linux-$VERSION/ as needed....." >&2
	fi
	;;
    *)
	barf "Unknown kernel version $VERSION"
	;;
esac

make_exec linux-$VERSION

# sample ~/.grabkernelrc file (remove '#' to activate a line):
#PATCHDIR=~/kernel-patches
#MIRRORS="http://www.kernel.org/pub/linux/kernel"