autopatch

#!/bin/bash

# This script checks to see if there is a newer patch version of the Linux
# kernel you're already tracking, and eases the toil of these minor updates.
# It is intended for use with an LTS series such as 3.2, 3.4, or 3.18

# CURRENTLY UPDATING -RT PATCH IS POORLY TESTED! -----------------
# If you have already applied the -rt patch, this script will also
# update it.  It does not support both at the same time.
# ----------------------------------------------------------------

# Copyright (C) 2011-2017  Nicholas D Steeves <nsteeves@gmail.com>
# Distributed under the terms of the GPLv2 license.
#
# Requires coretools, curl, grep, patch, bzip2, and xzutils

# TODO --cron
# "autopatch --cron" does not patch anything, but it will check for a new
# version, and silently exit if you are up to date.  If you are not up to
# date, it will notify you of the new version.
#

mirror="https://www.kernel.org/pub/linux/kernel"

if [ -x "$(command -v pager)" ]; then
    pager=pager
else
    pager=less
fi

autopatch=`basename $0`

get_local_version() {
    for i in VERSION PATCHLEVEL SUBLEVEL NAME CKVERSION; do
	i_scratch=`grep ^$i Makefile | sed 's/^.*=\ //'`
	export $i="$i_scratch"
    done
    if [ -n "$CKVERSION" ]; then
        #	ck="-ck"
        echo "-ck patch is unsupported"
        echo "exiting"
        exit 1
    fi    
    if [ -e localversion-rt ]; then
	rt="-rt"
	rtversion=`sed 's/[^0-9]*//g' < localversion-rt`
    fi
    if [ -n $CKVERSION ] && [ -e localversion-rt ]; then
	echo "You have patched $PWD with both -ck and -rt"
	echo "$autopatch will probably fail..."
	sleep 3
	echo "Aborting.  Please choose -ck or -rt before trying again"
	exit 1
    fi
}

get_latest_versions() {
    target=`curl -s $mirror/v$VERSION.x/ | \
            grep patch-$VERSION\.$PATCHLEVEL.*xz | \
            grep -o -E 'href="([^\"#]+)"' | \
            sed -e 's/.*-//' -e 's/\.[^\.]*$//' | \
            sort -V | sed '$!d'`
    newsublevel=`echo $target | cut -d. -f3`
    if [ -n "$rt" ]; then
	newrtversion=`curl -s $mirror/projects/rt/$VERSION.$PATCHLEVEL | \
            sed -e /tar/d -n -e 's/^.*patch-//' -e 's/\.patch\.xz.*$//p' \
            | tail -1`
	maxsublevel=`echo $newrtversion | sed -e "s/$VERSION\.$PATCHLEVEL\.//" \
            -e "s/-rt.*//"`
        if [ $newsublevel -gt $maxsublevel ]; then
	    # If not --cron, execute these echo commands
	    # otherwise, stay silent!
	    echo "The most recent -rt patch is for linux-$VERSION.$maxsublevel"
	    echo "Updating to $newrtversion instead of $target-rt*"
	    target=`echo $target | sed s/$newsublevel/$maxsublevel/`
	    newsublevel=$maxsublevel
	fi
    fi
    if [ -z "$newsublevel" ]; then
        echo "No patches have been released for $VERSION.$PATCHLEVEL.$SUBLEVEL"
        echo "You are already up to date!"
        exit 0
    fi
    echo "The latest available patch is linux-$target"
    if [ $VERSION.$PATCHLEVEL.$SUBLEVEL = $target ]; then
        echo "You are already up to date!"
        exit 0
    fi
    levelsdiff=$[$newsublevel-$SUBLEVEL]
}

get_changelogs () {
    #
    # Regrettably, I have been unable to find changelogs for
    # -ck or -rt
    #
    progress=$((SUBLEVEL+1))
    echo -n "View all $levelsdiff changelogs (y/n)? "
    read choice
    case "$choice" in
	yes | y | Yes | YES )
	    if [ $progress -ne $newsublevel ]; then
		echo "curl -s $mirror/v$VERSION.x/ChangeLog-$VERSION.$PATCHLEVEL.[$progress-$newsublevel]"
		curl -s "$mirror/v$VERSION.x/ChangeLog-$VERSION.$PATCHLEVEL.[$progress-$newsublevel]" 2> /dev/null | $pager
	    else
		echo "curl -s $mirror/v$VERSION.x/ChangeLog-$VERSION.$PATCHLEVEL.$newsublevel"
		curl -s "$mirror/v$VERSION.x/ChangeLog-$VERSION.$PATCHLEVEL.$newsublevel" 2> /dev/null | $pager
	    fi
	    ;;
	* )
	    false
	    ;;
    esac
}

clean_the_tree () {
    if [ -e .config ]; then
	lastconfig=`ls -l --time-style long-iso .config | cut -d\  -f6`
	echo "Backing up .config to dot_config_$lastconfig"
	sleep 2
	cp -a .config dot_config_$lastconfig
    fi
    echo "Cleaning up the tree . . ."
    sleep 1
    if [ -x "$(command -v make-kpkg)" ]; then
	make-kpkg clean
    else
	make distclean
    fi
}

remove_patches() {
    if [ -n "$CKVERSION" ]; then
	curl -C http://ck.kolivas.org/patches/$VERSION.0/$VERSION.$PATCHLEVEL/$VERSION.$PATCHLEVEL-ck1/patch-$VERSION.$PATCHLEVEL-ck1.bz2 > /tmp/patch-$VERSION.$PATCHLEVEL-ck1.bz2
	bzcat /tmp/patch-$VERSION.$PATCHLEVEL-ck1.bz2 | patch -p1 -R
    fi
    if [ -n "$rtversion" ]; then
	curl $mirror/projects/rt/$VERSION.$PATCHLEVEL/older/patches-$VERSION.$PATCHLEVEL.$SUBLEVEL-rt$rtversion.tar.xz | xzcat | patch -p1 -R
    fi
}


apply_patches() {
    # needs to be able to accept mainline, -rt, -ck as an argument
    # in the absence of an argument, it must default to mainline
    echo -en "\nApply all available $levelsdiff patches now? "
    while true; do
	read choice
	case "$choice" in
	    yes | y | Yes | YES )
	        break
		;;
	    no | n | No | NO )
	        echo "If you say so . . . "
		sleep 1
		echo "Goodbye!"
		exit 1
		;;
	    * )
		printf "Please answer yes or no\n\n"
		;;
	esac
    done

    clean_the_tree
    
    # At this point, $progress is $((SUBLEVEL + 1))
    tmplevel=$SUBLEVEL
    while [ $progress -le $newsublevel ]; do
	## Consider redoing this in a nicer way,
	## since $progress of $levelsdiff gives me options
	echo -en "Fetching sublevel $progress . . .\t"
	if [ $progress -eq 1 ];then
	    echo "curl -s $mirror/v$VERSION.x/patch-$VERSION.$PATCHLEVEL.$progress.xz"
	    curl -s $mirror/v$VERSION.x/patch-$VERSION.$PATCHLEVEL.$progress.xz | xzcat | patch -p1
	else
	    echo "curl -s $mirror/v$VERSION.x/incr/patch-$VERSION.$PATCHLEVEL.$tmplevel-$progress.xz"
	    curl -s  $mirror/v$VERSION.x/incr/patch-$VERSION.$PATCHLEVEL.$tmplevel-$progress.xz | xzcat | patch -p1
	fi
	if [ $? -ne 0 ]; then
	    echo "Patch failed!  Unsafe to continue."
	    echo "Aborting"
	    exit 1
	fi
	tmplevel=$((tmplevel+1))
	progress=$((progress+1))
    done
}

get_local_version
echo "Starting with linux-$VERSION.$PATCHLEVEL.$SUBLEVEL"
echo "Codename: $NAME"
get_latest_versions
get_changelogs
apply_patches
get_local_version
if [ "${PWD##*/}" != "linux-$VERSION.$PATCHLEVEL.$SUBLEVEL$ck$rt" ]; then
    if [ -d "../linux-$VERSION.$PATCHLEVEL.$SUBLEVEL" ]; then
	echo "Moving existing linux-$VERSION.$PATCHLEVEL.$SUBLEVEL$ck$rt out of the way"
	mv ../linux-$VERSION.$PATCHLEVEL.$SUBLEVEL$ck$rt \
	   ../../linux-$VERSION.$PATCHLEVEL.$SUBLEVEL$ck${rt}.old
    fi
    mv "$PWD" ../linux-$VERSION.$PATCHLEVEL.$SUBLEVEL$ck$rt
fi
echo -e "\nSuccess!  You now have linux-$VERSION.$PATCHLEVEL.$SUBLEVEL$ck$rt"
echo "Do not forgot to: cd ../linux-$VERSION.$PATCHLEVEL.$newsublevel$ck$rt"