ddwrt-installer.sh

#!/bin/sh
#set -x # uncomment/comment to enable/disable debug mode

#     name: ddwrt-installer.sh
#  version: 3.0.1, 15-aug-2022, by eibgrad
#  purpose: install pastebin script into dd-wrt router

# function usage()
usage() {
    echo 'Usage: ddwrt-installer.sh [options] pastebin-id [ext=sh]'
    echo
    echo '  Install pastebin script into dd-wrt router.'
    echo
    echo '  Installation directory hierarchy:'
    echo '    </path> (from --dir option)'
    echo '    /jffs/etc/config'
    echo '    /tmp'
    echo
    echo '  Options:'
    echo '    --dir PATH  installation directory (created as necessary)'
    echo "    --pre NUM   add prefix to filename (e.g., '01')"
    echo '    --nocom     remove blank lines and non-functional comments'
    echo '    --comp      same as --nocom, plus remove leading whitespace'
    echo '    --noprompt  silently overwrite files and accept defaults'
    echo '    --debug     install script w/ debugging mode enabled'
    echo '    -h,--help   this usage information'
    echo
    echo '  # e.g., install script w/o comments and w/ bash (sh) extension'
    echo '  ddwrt-installer.sh --nocom MxA19W1M'
    echo
}

# function query( message [default-reply] )
query() {
    local reply

    read -p "$1 " reply < /dev/tty
    [ "$reply" ] && echo "$reply" || echo "$2"
}

# function is_mounted( mounting-point )
is_mounted() { df | grep -Eq "[[:space:]]+${1}$"; }

# function customize()
customize() {
    # function _ddwrt_ovpn_split()
    _ddwrt_ovpn_split() {
        local route_up
        local route_down
        local default_vpn

        # function __add_directives()
        __add_directives() {
            local CONFIG='openvpncl_config'
            local TEMPF="/tmp/ddwrt-installer.$$.tmp"

            # retrieve current openvpn client config
            nvram get $CONFIG | tr -d '\r' > $TEMPF

            # delete any matching/competing directives (active or inactive)
            sed -r \
                -e '/^([[:space:]]|#|;)*(|--)route-up/d' \
                -e '/^([[:space:]]|#|;)*(|--)route-pre-down/d' \
                -e '/^([[:space:]]|#|;)*(|--)pull-filter.*redirect-gateway/d' \
                -e '/^([[:space:]]|#|;)*(|--)redirect-gateway/d' \
                -e '/^([[:space:]]|#|;)*(|--)redirect-private/d' \
                -i $TEMPF

            # delete old banner header and footer
            sed -i '/ added by ddwrt-installer /d' $TEMPF

            # configure default gateway (wan or vpn)
            local com="$([ ${default_vpn+x} ] && echo '#')"

            # add our directives
            {
            echo '# --- begin directives added by ddwrt-installer --- #'
            echo "route-up ${route_up}"
            echo "route-pre-down ${route_down}"
            echo "${com}pull-filter ignore redirect-gateway"
            echo "${com}redirect-private def1"
            echo '# ---- end directives added by ddwrt-installer ---- #'
            } >> $TEMPF

            # delete blank lines
            sed -i '/^[[:space:]]*$/d' $TEMPF

            # update openvpn client config
            nvram set $CONFIG="$(cat $TEMPF | tr -d '\r')"
            nvram commit &>/dev/null

            rm -f $TEMPF
        }

        if [ ! ${noprompt+x} ]; then
            # obtain openvpn default routing preference (default=lan->wan)
            while :; do
                case "$(query 'Default routing ([1]=lan->wan 2=lan->vpn)?' '1')" in
                    '1') break;;
                    '2') default_vpn=; break;;
                esac
            done
        fi

        route_up="$file_dir/route-up"
        route_down="$file_dir/route-down"

        # add symbolic links
        ln -sf "$file" "$route_up"
        ln -sf "$file" "$route_down"

        __add_directives
    }

    # script-specific customization (optional)
    case "$pbid" in
        'nC27ETsp') _ddwrt_ovpn_split;;
        'W2P3TDZT') _ddwrt_ovpn_split;;
        *) ;;
    esac
}

# function exit_1( [message] )
exit_1() { [ "$1" ] && echo "$1"; exit 1; }

# function exit_0( [message] )
exit_0() { [ "$1" ] && echo "$1"; exit 0; }

# handle help/usage requests
for opt; do case $opt in -h|--help) usage; exit 0;; esac; done

# try curl, fallback to wget
which curl &>/dev/null && GET_URL='curl -sLk' || GET_URL='wget -qO -'

# process command line options/arguments
while [ $# -gt 0 ]; do
    case $1 in
             '--dir') shift; file_dir="${1//[[:space:]]/}";;
             '--pre') shift; file_pre="${1//[[:space:]]/}";;
           '--nocom') nocom=; unset comp;;
            '--comp') comp=; unset nocom;;
        '--noprompt') noprompt=;;
           '--debug') debug=;;
                   *) break 2;;
    esac
    shift
done

# set pastebin-id
[ "$1" ] && pbid="$1" || exit_0 'info: nothing to do'

# set and verify extension
ext="$([ "$2" ] && echo "${2//[[:space:]]/}" || echo sh)"
echo $ext | grep -q '\.' && exit_1 "error: extension cannot contain '.'"

# construct pastebin url for retrieving raw file (obscure from hosting site)
url="$(echo wastebin | sed s/w/p/).com/raw/$pbid"

if [ ! "$file_dir" ]; then
    # locate storage
    if is_mounted '/jffs'; then
        file_dir='/jffs/etc/config'
    else
        file_dir='/tmp'
        echo 'warning: /jffs not mounted; using /tmp'
    fi
fi

# convert cryptic pastebin id to common name
case "$pbid" in
    'aySi7RhY') file='ddwrt-blacklist-domains';;
    'MxA19W1M') file='ddwrt-dhcp-lease-persist';;
    'VDZ32r2D') file='ddwrt-mount-usb-drives';;
    'TKdKUmY1') file='ddwrt-ovpn-client-killswitch';;
    'iNC273ER') file='ddwrt-ovpn-client-watchdog';;
    'gnxtZuqg') file='ddwrt-ovpn-remote-access';;
    'nC27ETsp') file='ddwrt-ovpn-split-advanced';;
    'W2P3TDZT') file='ddwrt-ovpn-split-basic';;
    '9DUMFJgN') file='ddwrt-pptp-policy-based-routing';;
    'NkKUUjsn') file='ddwrt-ultimate-dns-leak-test';;
    'NUb73JqK') file='ddwrt-wol-port-forward';;
    '2gg5ZdRY') file='importvpncl';;
             *) file="pastebin-$pbid";;
esac

# check for existing files
efiles="$(echo $file_dir/*$file*)"

if [ ! ${noprompt+x} ] && [ "$efiles" != "$file_dir/*$file*" ]; then
    efile_count=0

    for efile in $efiles; do
        echo "warning: existing file: $efile"
        let efile_count++
    done

    if [ $efile_count -gt 0 ]; then
        # obtain permission to overwrite existing file(s)
        while :; do
            case "$(query 'Overwrite existing file(s) (yes/[no])?' 'no')" in
                'yes') break;;
                 'no') exit_0 'info: installation aborted';;
            esac
        done

        # delete existing files
        for efile in $efiles; do rm -f $efile; done
    fi
fi

# option pre: add prefix to filename
[ "$file_pre" ] && file="${file_pre}-$file"

# create directory
if ! mkdir -p "$file_dir" 2>/dev/null; then
    exit_1 "error: cannot create directory: $file_dir"
fi

# construct full path + filename + extension
file="$file_dir/$file.$ext"

# confirm file can be created through initialization
if ! (> "$file") 2>/dev/null; then
    exit_1 "error: cannot create file: $file"
fi

# retrieve raw file from pastebin
$GET_URL $url | tr -d '\r' > "$file"; echo >> "$file"

# verify file is bash script by locating shebang
if ! head -n1 "$file" | grep -Eq '^#!/bin/sh($|[[:space:]]+)'; then
    rm -f "$file"
    exit_1 "error: file not found: $pbid"
fi

# option nocom: remove blank lines and non-functional comments
[ ${nocom+x} ] && sed -ri '/^[[:space:]]*($|#([[:space:]]|#|$))/d' "$file"

# option comp: same as --nocom, plus remove leading whitespace
[ ${comp+x}  ] && sed -ri 's/^[[:space:]]*//;/^($|#([[:space:]]|#|$))/d' "$file"

# option debug: install script w/ debugging mode enabled
[ ${debug+x} ] && sed -ri '2 s/^#(DEBUG=; )/\1/' "$file"

# mark file executable
chmod +x "$file"

# check for any script-specific customization
customize

exit_0 "installed: $file"