noipupdater.sh

#!/bin/bash

# Copyright (C) 2013 Matthew D. Mower
# Copyright (C) 2012 AntonioCS
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

set -eo pipefail

# Functions

function usage() {
    console_error "$0 [-c /path/to/config] [-i 123.123.123.123]"
    exit 1
}

function cmd_exists() {
    command -v "$1" > /dev/null 2>&1
}

# Adapted from one of the more readable answers by Gilles at
# https://unix.stackexchange.com/questions/60653/urlencode-function/60698#60698
function urlencode() {
    local string="$1"
    while [ -n "$string" ]; do
        local tail="${string#?}"
        local head="${string%"$tail"}"
        case "$head" in
            [-._~0-9A-Za-z])
                printf "%c" "$head";;
            *)
                printf "%%%02x" "'$head"
        esac
        string="$tail"
    done
}

function http_get() {
    if cmd_exists curl; then
        curl -s --user-agent "$USERAGENT" "$1"
    elif cmd_exists wget; then
        wget -q -O - --user-agent="$USERAGENT" "$1"
    else
        console_error "No http tool found. Install curl or wget."
        exit 1
    fi
}

function parse_date() {
    local string="$1"
    PARSED_DATE=$(date -d "$string" +'%s' 2>/dev/null || true)
    if [ -z "$PARSED_DATE" ] && cmd_exists gdate; then
        PARSED_DATE=$(gdate -d "$string" +'%s' 2>/dev/null || true)
    fi
    if [ -z "$PARSED_DATE" ]; then
        PARSED_DATE=$(date -jf "%Y-%m-%d %H:%M:%S" "$string" +'%s' 2>/dev/null || true)
    fi
    if [ -z "$PARSED_DATE" ]; then
        console_error "Could not parse date."
        exit 1
    fi
    return 0
}

# IP Validator
# http://www.linuxjournal.com/content/validating-ip-address-bash-script
function valid_ip() {
    local ip=$1
    local stat=1

    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
        OIFS=$IFS
        IFS='.'
        ip=($ip)
        IFS=$OIFS
        [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 \
            && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]
        stat=$?
    fi

    return $stat
}

function get_logline() {
    local host
    local response
    local response_a
    local response_b

    host="$1"
    response=$(echo "$2" | tr -cd "[:print:]")
    response_a=$(echo "$response" | awk '{ print $1 }')

    case $response_a in
        "good")
            response_b=$(echo "$response" | awk '{ print $2 }')
            LOGLINE="(good) [$host] DNS hostname successfully updated to $response_b."
            ;;
        "nochg")
            response_b=$(echo "$response" | awk '{ print $2 }')
            LOGLINE="(nochg) [$host] IP address is current: $response_b; no update performed."
            ;;
        "nohost")
            LOGLINE="(nohost) [$host] Hostname supplied does not exist under specified account. Revise config file."
            ;;
        "badauth")
            LOGLINE="(badauth) [$host] Invalid username password combination."
            ;;
        "badagent")
            LOGLINE="(badagent) [$host] Client disabled - No-IP is no longer allowing requests from this update script."
            ;;
        '!donator')
            LOGLINE='(!donator)'" [$host] An update request was sent including a feature that is not available."
            ;;
        "abuse")
            LOGLINE="(abuse) [$host] Username is blocked due to abuse."
            ;;
        "911")
            LOGLINE="(911) [$host] A fatal error on our side such as a database outage. Retry the update in no sooner than 30 minutes."
            ;;
        "")
            LOGLINE="(empty) [$host] No response received from No-IP. This may be due to rate limiting or a server-side problem."
            ;;
        *)
            LOGLINE="(error) [$host] Could not understand the response from No-IP. The DNS update server may be down."
            ;;
    esac

    return 0
}

function console_info() {
    local msg="$1"
    local lvl="$CONSOLE_OUTPUT_LEVEL"

    if [ -z "$lvl" ] || (( lvl < 3 )); then
        echo "$msg"
    fi
}

function console_error() {
    local msg="$1"
    local lvl="$CONSOLE_OUTPUT_LEVEL"

    if [ -z "$lvl" ] || (( lvl < 5 )); then
        echo "$msg" >&2
    fi
}

# Defines

CONFIGFILE=""
NEWIP=""
while getopts 'c:i:' flag; do
    case "${flag}" in
        c) CONFIGFILE="${OPTARG}" ;;
        i) NEWIP="${OPTARG}" ;;
        *) usage ;;
    esac
done

if [ -z "$CONFIGFILE" ]; then
    CONFIGFILE="$( cd "$( dirname "$0" )" && pwd )/config"
fi

if [ -e "$CONFIGFILE" ]; then
    source "$CONFIGFILE"
else
    console_error "Config file not found."
    exit 1
fi

if ! (( CONSOLE_OUTPUT_LEVEL >= 0 && CONSOLE_OUTPUT_LEVEL <= 6 )); then
    CONSOLE_OUTPUT_LEVEL=0
fi

if [ -n "$NEWIP" ] && ! valid_ip "$NEWIP"; then
    console_error "Invalid IP address specified."
    exit 1
fi

if [ -z "$USERNAME" ] || [ -z "$PASSWORD" ]; then
   console_error "USERNAME or PASSWORD has not been set in the config file."
   exit 1
fi

USERAGENT="Bash No-IP Updater/1.3 $USERNAME"

if [ ! -d "$LOGDIR" ]; then
    if ! mkdir -p "$LOGDIR"; then
        console_error "Log directory could not be created or accessed."
        exit 1
    fi
fi

LOGFILE=${LOGDIR%/}/noip.log
if [ ! -e "$LOGFILE" ]; then
    if ! touch "$LOGFILE"; then
        console_error "Log files could not be created. Is the log directory writable?"
        exit 1
    fi
fi
if [ ! -w "$LOGFILE" ]; then
    console_error "Log file not writable."
    exit 1
fi

NOW=$(date +'%s')
LOGDATE="[$(date +'%Y-%m-%d %H:%M:%S')]"

# Program

if [ -e "$LOGFILE" ] && tail -n1 "$LOGFILE" | grep -q -m1 '(abuse)'; then
    # set -e aborts after this read command unless `|| true` is appended
    read -r -d '' CONSOLE_MSG << EOL || true
This account has been flagged for abuse. You need to contact noip.com to resolve
the issue. Once you have confirmed your account is in good standing, remove the
log line containing (abuse) from:
  $LOGFILE
Then, re-run this script.
EOL
    console_error "$CONSOLE_MSG"
    exit 1
fi

if [ -e "$LOGFILE" ]; then
    if NINELINE=$(grep '(911)' "$LOGFILE" | tail -n 1); then
        LASTNL=$([[ "$NINELINE" =~ \[([^\]]+)\] ]] && echo "${BASH_REMATCH[1]}")
        parse_date "$LASTNL"
        if [ $((NOW - PARSED_DATE)) -lt 1800 ]; then
            LOGLINE="Response code 911 received less than 30 minutes ago; canceling request."
            console_error "$LOGLINE"
            echo "$LOGDATE $LOGLINE" >> "$LOGFILE"
            exit 1
        fi
    fi
fi

if [ "$ROTATE_LOGS" = true ]; then
    LOGLENGTH=$(wc -l "$LOGFILE" | awk '{ print $1 }')
    if [ $((LOGLENGTH)) -ge 10010 ]; then
        BACKUPDATE=$(date +'%Y-%m-%d_%H%M%S')
        BACKUPFILE="$LOGFILE-$BACKUPDATE.log"
        if touch "$BACKUPFILE"; then
            head -10000 "$LOGFILE" > "$BACKUPFILE"
            if cmd_exists gzip; then
                gzip "$BACKUPFILE"
            fi
            LASTLINES=$(tail -n +10001 "$LOGFILE")
            echo "$LASTLINES" > "$LOGFILE"
            console_info "Log file rotated"
        else
            console_error "Log file could not be rotated"
        fi
    fi
fi

USERNAME=$(urlencode "$USERNAME")
PASSWORD=$(urlencode "$PASSWORD")
ENCODED_HOST=$(urlencode "$HOST")

REQUEST_URL="https://$USERNAME:$PASSWORD@dynupdate.no-ip.com/nic/update?hostname=$ENCODED_HOST"
if [ -n "$NEWIP" ]; then
    NEWIP=$(urlencode "$NEWIP")
    REQUEST_URL="$REQUEST_URL&myip=$NEWIP"
fi

RESPONSE=$(http_get "$REQUEST_URL")
OIFS=$IFS
IFS=$'\n'
SPLIT_RESPONSE=( $(echo "$RESPONSE" | grep -o '[0-9a-z!]\+\( [0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\)\?') )
IFS=','
SPLIT_HOST=( $HOST )
IFS=$OIFS

for index in "${!SPLIT_HOST[@]}"; do
    get_logline "${SPLIT_HOST[index]}" "${SPLIT_RESPONSE[index]}"
    console_info "$LOGLINE"
    echo "$LOGDATE $LOGLINE" >> "$LOGFILE"
done

exit 0