[petitboot] / utils / pb-plugin

#!/bin/sh

__dest=/
__pb_mount_dir=/var/petitboot/mnt/dev/
plugin_abi=1
plugin_ext=pb-plugin
plugin_meta=pb-plugin.conf
plugin_meta_dir=etc/preboot-plugins/
plugin_meta_path=$plugin_meta_dir$plugin_meta
plugin_wrapper_dir=/var/lib/pb-plugins/bin

usage()
{
        cat <<EOF
Usage: $0 <command>

Where <command> is one of:
  install <FILE|URL> - install plugin from FILE/URL
  scan               - look for available plugins on attached devices
  create <DIR>       - create a new plugin archive from DIR
EOF
}

is_url()
{
        local url tmp
        url=$1
        tmp=${url#*://}
        [ "$url" != "$tmp" ]
}

download()
{
        local url file proto
        url=$1
        file=$2
        proto=${url%://*}

        case "$proto" in
        http)
                wget -O - "$url" > $file
                ;;
        ftp)
                ncftpget -c "$url" > $file
                ;;
        *)
                echo "error: Unsuported protocol $proto" >&2
                false
        esac
}

plugin_info()
{
        local title
        if [ "$PLUGIN_VENDOR" ]
        then
                title="$PLUGIN_VENDOR: $PLUGIN_NAME"
        else
                title="$PLUGIN_NAME"
        fi

        echo "$title"
        echo "  (version $PLUGIN_VERSION)"
}

# How the ABI versioning works:
#
#  - This script has an ABI defined ($plugin_abi)
#
#  - Plugins have a current ABI number ($PLUGIN_ABI), and a minimum supported
#    ABI number ($PLUGIN_ABI_MIN).
#
#  - A plugin is OK to run if:
#    - the plugin's ABI matches the script ABI, or
#    - the plugin's minimum ABI is lower than or equal to the script ABI
plugin_abi_check()
{
        [ -n "$PLUGIN_ABI" ] &&
                ( [ $PLUGIN_ABI -eq $plugin_abi ] ||
                  [ $PLUGIN_ABI_MIN -le $plugin_abi ] )
}

do_wrap()
{
        local base binary dir

        base=$1
        binary=$2
        shift 2

        for dir in etc dev sys proc var
        do
                [ -e "$base/$dir" ] || mkdir -p "$base/$dir"
        done

        cp /etc/resolv.conf $base/etc
        mount -o bind /dev $base/dev
        mount -o bind /sys $base/sys
        mount -o bind /proc $base/proc
        mount -o bind /var $base/var

        chroot "$base" "$binary" "$@"

        umount $base/dev
        umount $base/sys
        umount $base/proc
        umount $base/var
}

__create_wrapper()
{
        local base binary wrapper

        base=$1
        binary=$2
        wrapper=$plugin_wrapper_dir/$(basename $binary)

        mkdir -p $plugin_wrapper_dir

        cat <<EOF > $wrapper
#!/bin/sh

exec $(realpath $0) __wrap '$base' '$binary' "\$@"
EOF

        chmod a+x $wrapper
}

do_install()
{
        local url name file __dest

        url=$1

        if [ -z "$url" ]
        then
                echo "error: install requires a file/URL argument." >&2
                exit 1
        fi

        name=${url##*/}

        if is_url "$url"
        then
                file=$(mktemp)
                trap "rm '$file'" EXIT
                download "$url" "$file"
                if [ $? -ne 0 ]
                then
                        echo "error: failed to download $url" >&2
                        exit 1
                fi
        else
                file=$url
                if [ ! -r "$file" ]
                then
                        echo "error: $file doesn't exist or is not readable" >&2
                        exit 1
                fi
        fi

        echo "File '$name' has the following sha256 checksum:"
        echo
        sha256sum "$file" | cut -f1 -d' '
        echo

        echo "Do you want to install this plugin? (y/N)"
        read resp

        case $resp in
        [yY]|[yY][eE][sS])
                ;;
        *)
                echo "Cancelled"
                exit 0
                ;;
        esac

        __dest=$(mktemp -d)
        gunzip -c "$file" | ( cd $__dest && cpio -i -d)

        if [ $? -ne 0 ]
        then
                echo "error: Failed to extract archive $url, exiting"
                rm -rf $__dest
                exit 1
        fi

        . $__dest/$plugin_meta_path

        if ! plugin_abi_check
        then
                echo "Plugin at $url is incompatible with this firmware," \
                        "exiting."
                rm -rf $__dest
                exit 1
        fi

        for binary in ${PLUGIN_EXECUTABLES}
        do
                __create_wrapper "$__dest" "$binary"
        done

        echo "Plugin installed"
        plugin_info
}

do_scan_mount()
{
        local mnt dev plugin_path __meta_tmp
        mnt=$1
        dev=$(basename $mnt)

        for plugin_path in $mnt/*.$plugin_ext
        do
                [ -e "$plugin_path" ] || continue

                # extract plugin metadata to a temporary directory
                __meta_tmp=$(mktemp -d)
                [ -d $__meta_tmp ] || continue
                gunzip -c "$plugin_path" 2>/dev/null |
                        (cd $__meta_tmp &&
                                cpio -i -d $plugin_meta_path 2>/dev/null)
                if ! [ $? = 0 -a -e "$plugin_path" ]
                then
                        rm -rf $__meta_tmp
                        continue
                fi

                (
                        . $__meta_tmp/$plugin_meta_path

                        plugin_abi_check || exit 1

                        printf "Plugin found on %s:\n" $dev
                        plugin_info
                        printf "\n"
                        printf "To run this plugin:\n"
                        printf "  $0 run $plugin_path\n"
                        printf "\n"
                )
                if [ $? = 0 ]
                then
                        found=1
                fi
                rm -rf $__meta_tmp
        done
}

do_scan()
{
        local found mnt
        found=0
        for mnt in $__pb_mount_dir/*
        do
                do_scan_mount $mnt
        done

        if [ "$found" = 0 ]
        then
                echo "No plugins found"
        fi
}

guided_meta()
{
        local vendorname vendorshortname
        local pluginname pluginnhortname
        local version date executable
        local file

        file=$1

cat <<EOF

Enter the vendor company / author name. This can contain spaces.
(eg. 'Example Corporation')
EOF
        read vendorname
cat <<EOF

Enter the vendor shortname. This should be a single-word abbreviation, in all
lower-case. This is only used in internal filenames.

Typically, a stock-ticker name is used for this (eg 'exco')
EOF
        read vendorshortname

cat <<EOF

Enter the descriptive plugin name. This can contain spaces, but should only be
a few words in length (eg 'RAID configuration utility')
EOF
        read pluginname

cat <<EOF

Enter the plugin shortname. This should not contain spaces, but hyphens are
fine (eg 'raid-config'). This is only used in internal filnames.
EOF
        read pluginshortname


cat <<EOF

Enter the plugin version. This should not contain spaces (eg 1.2):
EOF
        read version

cat <<EOF

Enter the full path (within the plugin root) to the plugin executable file(s).
These will be exposed as wrapper scripts, to be run from the standard petitboot
shell environment (eg, /usr/bin/my-raid-config).

If multiple executables are provided, separate with a space.
EOF
        read executables

        date=$(date +%Y-%m-%d)

        mkdir -p $(dirname $file)

        cat <<EOF > $file
PLUGIN_ABI='$plugin_abi'
PLUGIN_ABI_MIN='1'
PLUGIN_VENDOR='$vendorname'
PLUGIN_VENDOR_ID='$vendorshortname'
PLUGIN_NAME='$pluginname'
PLUGIN_ID='$pluginshortname'
PLUGIN_VERSION='$version'
PLUGIN_DATE='$date'
PLUGIN_EXECUTABLES='$executables'
EOF

}

do_create()
{
        local src meta_dir_abs meta_file
        src=$1

        if [ -z "$src" ]
        then
                echo "error: missing source directory" >&2
                usage
                exit 1
        fi

        if [ ! -d "$src" ]
        then
                echo "error: source directory missing" >&2
                exit 1
        fi

        meta_file=$src/$plugin_meta_path

        if [ ! -e $meta_file ]
        then
                echo "No plugin metadata file found. " \
                        "Would you like to create one? (Y/n)"
                read resp
                case "$resp" in
                [nN]|[nN][oO])
                        echo "Cancelled, exiting"
                        exit 1
                        ;;
                esac
                guided_meta $meta_file || exit
        fi

        # Sanity check metadata file
        . $meta_file
        if [ ! -n "$PLUGIN_ABI" ]
        then
                echo "error: no PLUGIN_ABI defined in metadata" &>2
                exit 1
        fi
        if [ "$PLUGIN_ABI" != "$plugin_abi" ]
        then
                echo "warning: PLUGIN_ABI (=$PLUGIN_ABI) is not $plugin_abi" &>2
        fi
        if [ ! -n "$PLUGIN_VENDOR" ]
        then
                echo "error: no PLUGIN_VENDOR defined in metadata" &>2
                exit 1
        fi
        if [ ! -n "$PLUGIN_VENDOR_ID" ]
        then
                echo "error: no PLUGIN_VENDOR_ID defined in metadata" &>2
                exit 1
        fi
        if [ ! -n "$PLUGIN_NAME" ]
        then
                echo "error: no PLUGIN_NAME defined in metadata" &>2
                exit 1
        fi
        if [ ! -n "$PLUGIN_ID" ]
        then
                echo "error: no PLUGIN_ID defined in metadata" &>2
                exit 1
        fi
        if [ ! -n "$PLUGIN_VERSION" ]
        then
                echo "error: no PLUGIN_VERSION defined in metadata" &>2
                exit 1
        fi
        if [ ! -n "$PLUGIN_DATE" ]
        then
                echo "error: no PLUGIN_DATE defined in metadata" &>2
                exit 1
        fi
        if [ ! -n "$PLUGIN_EXECUTABLES" ]
        then
                echo "error: no PLUGIN_EXECUTABLES defined in metadata" &>2
                exit 1
        fi

        outfile=${PLUGIN_ID}-${PLUGIN_VERSION}.${plugin_ext}

        (
                cd $src
                find -mindepth 1 | cpio -o -Hnewc -v
        ) | gzip -c > $outfile

        echo
        echo "Plugin metadata:"
        sed -e 's/^/  /' $meta_file
        echo

        echo "User-visible metadata:"
        plugin_info | sed -e 's/^/  /'

        echo

cat <<EOF
Plugin created in:
  $outfile

Ship this file in the top-level-directory of a USB device or CD to have it
automatically discoverable by 'pb-plugin scan'. This file can be re-named,
but must retain the .$plugin_ext extension to be discoverable.
EOF
}

test_http_download()
{
        local tmp ref

        tmp=$(mktemp -p $test_tmpdir)
        ref=$(mktemp -p $test_tmpdir)

        echo $RANDOM > $ref

        wget()
        {
                cat $ref
        }

        download http://example.com/test $tmp
        cmp -s "$ref" "$tmp"
}

test_ftp_download()
{
        local tmp ref

        tmp=$(mktemp -p $test_tmpdir)
        ref=$(mktemp -p $test_tmpdir)

        echo $RANDOM > $ref

        ncftpget()
        {
                cat $ref
        }

        download ftp://example.com/test $tmp
        cmp -s "$ref" "$tmp"
}

test_abi_check()
{
        (
                plugin_abi=$1
                PLUGIN_ABI=$2
                PLUGIN_ABI_MIN=$3
                plugin_abi_check
        )
}

test_scan()
{
        __pb_mount_dir="$test_tmpdir/mnt"
        mnt_dir="$__pb_mount_dir/sda"
        mkdir -p $mnt_dir/$plugin_meta_dir
        (
                echo "PLUGIN_ABI=$plugin_abi"
                echo "PLUGIN_NAME=test"
                echo "PLUGIN_VERSION=1"
                echo "PLUGIN_EXECUTABLES=/bin/sh"
        ) > $mnt_dir/$plugin_meta_path
        (
                cd $mnt_dir;
                find -mindepth 1 | cpio -o -Hnewc 2>/dev/null
        ) | gzip -c > $mnt_dir/test.$plugin_ext

        do_scan | grep -q 'test'
}

test_scan_nogzip()
{
        __pb_mount_dir="$test_tmpdir/mnt"
        mnt_dir="$__pb_mount_dir/sda"
        stderr_file="$test_tmpdir/stderr"

        mkdir -p $mnt_dir
        echo "invalid" > $mnt_dir/nogzip.$plugin_ext

        do_scan 2>$stderr_file | grep -q 'No plugins'

        [ $? = 0 ] || return 1

        if [ -s "$stderr_file" ]
        then
                echo "Scan with invalid (non-gzip) file produced error output" \
                        >&2
                cat "$stderr_file"
                return 1
        fi
        true
}

test_scan_nocpio()
{
        __pb_mount_dir="$test_tmpdir/mnt"
        mnt_dir="$__pb_mount_dir/sda"
        stderr_file="$test_tmpdir/stderr"

        mkdir -p $mnt_dir
        echo "invalid" | gzip -c > $mnt_dir/nogzip.$plugin_ext

        do_scan 2>$stderr_file | grep -q 'No plugins'

        [ $? = 0 ] || return 1

        if [ -s "$stderr_file" ]
        then
                echo "Scan with invalid (non-cpio) file produced error output" \
                        >&2
                cat "$stderr_file"
                return 1
        fi
        true
}

test_scan_multiple()
{
        __pb_mount_dir="$test_tmpdir/mnt"
        mnt_dir="$__pb_mount_dir/sda"
        outfile=$test_tmpdir/scan.out

        for i in 1 2
        do
                mkdir -p $mnt_dir/$plugin_meta_dir
                (
                        echo "PLUGIN_ABI=$plugin_abi"
                        echo "PLUGIN_NAME=test-$i"
                        echo "PLUGIN_VERSION=1"
                        echo "PLUGIN_EXECUTABLES=/bin/sh"
                ) > $mnt_dir/$plugin_meta_path
                (
                        cd $mnt_dir;
                        find -mindepth 1 | cpio -o -Hnewc 2>/dev/null
                ) | gzip -c > $mnt_dir/test-${i}.$plugin_ext
                rm -rf $mnt_dir/$plugin_meta_dir
        done

        do_scan >$outfile

        grep -q 'test-1' $outfile && grep -q 'test-2' $outfile
}

test_scan_wrongabi()
{
        __pb_mount_dir="$test_tmpdir/mnt"
        mnt_dir="$__pb_mount_dir/sda"
        mkdir -p $mnt_dir/$plugin_meta_dir
        (
                echo "PLUGIN_ABI=$(($plugin_abi + 1))"
                echo "PLUGIN_ABI_MIN=$(($plugin_abi + 1))"
                echo "PLUGIN_NAME=test"
                echo "PLUGIN_VERSION=1"
                echo "PLUGIN_EXECUTABLES=/bin/sh"
        ) > $mnt_dir/$plugin_meta_path
        (
                cd $mnt_dir;
                find -mindepth 1 | cpio -o -Hnewc 2>/dev/null
        ) | gzip -c > $mnt_dir/test.$plugin_ext

        do_scan | grep -q 'No plugins'
}

test_empty_scan()
{
        __pb_mount_dir="$test_tmpdir/mnt"
        mkdir -p $__pb_mount_dir
        do_scan | grep -q "No plugins"
}

test_setup()
{
        n=$(($n+1))

        test_tmpdir="$tests_tmpdir/$n"
        mkdir "$test_tmpdir"
}

test_teardown()
{
        true
}

test_failed=0
do_test()
{
        local tstr op

        tstr="$@"
        op=-eq

        if [ "x$1" = "x!" ]
        then
                op=-ne
                shift
        fi

        test_setup
        ( $@ )
        local rc=$?
        test_teardown

        if [ $rc $op 0 ]
        then
                echo PASS: "$tstr"
        else
                echo FAIL: "$tstr"
                test_failed=1
                false
        fi
}

do_tests()
{
        local tests_tmpdir n

        tests_tmpdir=$(mktemp -d)
        n=0

        do_test ! is_url "/test"
        do_test ! is_url "./test"
        do_test ! is_url "../test"
        do_test ! is_url "test"
        do_test is_url "http://example.com/path"
        do_test is_url "git+ssh://example.com/path"
        do_test test_http_download
        do_test test_ftp_download
        do_test ! test_abi_check
        do_test ! test_abi_check 1
        do_test test_abi_check 1 1
        do_test test_abi_check 1 1 1
        do_test test_abi_check 1 2 0
        do_test test_abi_check 1 2 1
        do_test ! test_abi_check 1 2 2
        do_test test_scan
        do_test test_scan_nogzip
        do_test test_scan_nocpio
        do_test test_scan_multiple
        do_test test_scan_wrongabi
        do_test test_empty_scan

        if [ $test_failed = 0 ]
        then
                echo "$n tests passed"
        else
                echo "Tests failed"
        fi
        rm -rf "$tests_tmpdir"

        [ $test_failed = 0 ]
}

case "$1" in
install)
        shift
        do_install $@
        ;;
scan)
        shift
        do_scan $@
        ;;
create)
        shift
        do_create $@
        ;;
__wrap)
        shift
        do_wrap $@
        ;;
__test)
        shift
        do_tests $@
        ;;
"")
        echo "error: Missing command" >&2
        usage
        exit 1
        ;;
*)
        echo "Invalid command: $s" >&2
        usage
        exit 1
esac