feat: ✨ validate ip address respons from ip check web service

Dockerfile

@@ -1,4 +1,5 @@
 FROM alpine:latest
+
 RUN \
 apk update \
 && \
@@ -7,6 +8,13 @@ bash \
 curl \
 jq \
 bind-tools
+
 WORKDIR /usr/src/app
+
 COPY . .
-ENTRYPOINT ["/bin/bash", "/usr/src/app/dynb.sh"]
+
+ENTRYPOINT ["/bin/bash", "/usr/src/app/dynb.sh"]
+
+LABEL org.opencontainers.image.source="https://github.com/EV21/dynb"
+LABEL org.opencontainers.image.description="DynB - dynamic DNS update client."
+LABEL org.opencontainers.image.licenses="MIT"

dynb.sh

@@ -51,6 +51,7 @@ _network_interface=
 ######################################################
 ## You don't need to change the following variables ##
 _INWX_JSON_API_URL=https://api.domrobot.com/jsonrpc/
+_internet_connectivity_test_server=https://www.google.de
 _new_IPv4=
 _new_IPv6=
 _dns_records=
@@ -65,7 +66,7 @@ _response=
 _statusHostname=
 _statusUsername=
 _statusPassword=
-_version=0.1.2
+_version=0.3.0
 _userAgent="DynB/$_version github.com/EV21/dynb"
 _configFile=$HOME/.local/share/dynb/.env
 _statusFile=/tmp/dynb.status
@@ -73,6 +74,31 @@ _debug=0
 _minimum_looptime=60
 _loopMode=0
 
+# Ansi color code variables
+yellow_color="\e[0;33m"
+green_color="\e[0;92m"
+expand_bg="\e[K"
+red_color_bg="\e[0;101m${expand_bg}"
+bold="\e[1m"
+reset_color_modification="\e[0m"
+
+REGEX_IPv4="^(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])$"
+REGEX_IPv6="^(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))$"
+
+function is_IPv4_address() {
+  if [[ $1 =~ $REGEX_IPv4 ]]
+  then return 0
+  else return 1
+  fi
+}
+
+function is_IPv6_address() {
+  if [[ $1 =~ $REGEX_IPv6 ]]
+  then return 0
+  else return 1
+  fi
+}
+
 function loopMode() {
   if [[ $_loopMode -eq 1 ]]; then
     return 0
@@ -90,16 +116,18 @@ function debugMode() {
 }
 
 function infoMessage() {
-  echo "$(logtime) INFO: $*"
+  echo -e "${green_color}$(logtime) INFO: $*${reset_color_modification}"
 }
 
 function debugMessage() {
   if debugMode; then
-    echo "$(logtime) DEBUG: $*"
+    echo -e "${yellow_color}$(logtime) DEBUG: ${*}${reset_color_modification}"
   fi
 }
 
-function errorMessage() { printf "$(logtime) ERROR: %s\n" "$*" >&2; }
+function errorMessage() {
+  echo -e "${red_color_bg}${bold}$(logtime) ERROR: $*${reset_color_modification}" >&2
+}
 
 function logtime() {
   LOGTIME=$(date "+%Y-%m-%d %H:%M:%S")
@@ -209,7 +237,7 @@ function updateRecord() {
         --request POST $_INWX_JSON_API_URL \
         --data "$request"
     )
-    echo -e "$(echo "$_response" | jq --raw-output '.msg')\n Domain: $DYNB_DYN_DOMAIN\n new IPv${1}: $IP"
+    infoMessage "$(echo "$_response" | jq --raw-output '.msg')\n Domain: $DYNB_DYN_DOMAIN\n New IPv${1}: $IP"
   fi
 }
 
@@ -427,6 +455,11 @@ function ipHasChanged() {
   case ${1} in
     4)
       remote_ip=$(getRemoteIP 4 $_ipv4_checker)
+      if ! is_IPv4_address "$remote_ip"
+      then
+        errorMessage "The response from the IP check server is not an IPv4 address: $remote_ip"
+        return 0
+      fi
       if [[ $DYNB_UPDATE_METHOD == domrobot ]]; then
         dns_ip=$(getDNSIP A)
       else
@@ -439,13 +472,20 @@ function ipHasChanged() {
           errorMessage "DNS request failed $dig_response"
           return 0
         fi
-        dns_ip=$dig_response
+        # If the dns resolver lists multiple records in the answer section we filter the first line
+        # using short option "-n" and not "--lines" because of alpines limited BusyBox head command
+        dns_ip=$(echo "$dig_response" | head -n 1)
       fi
       _new_IPv4=$remote_ip
-      debugMessage "New IPv4: $_new_IPv4 old was: $dns_ip"
+      debugMessage "IPv4 from remote IP check server: $_new_IPv4, IPv4 from DNS: $dns_ip"
       ;;
     6)
       remote_ip=$(getRemoteIP 6 $_ipv6_checker)
+      if ! is_IPv6_address "$remote_ip"
+      then
+        errorMessage "The response from the IP check server is not an IPv6 address: $remote_ip"
+        return 0
+      fi
       if [[ $DYNB_UPDATE_METHOD == domrobot ]]; then
         dns_ip=$(getDNSIP AAAA)
       else
@@ -458,18 +498,22 @@ function ipHasChanged() {
           errorMessage "DNS request failed $dig_response"
           return 0
         fi
-        dns_ip=$dig_response
+        # If the dns server lists multiple records in the answer section we filter the first line
+        dns_ip=$(echo "$dig_response" | head -n 1)
       fi
       _new_IPv6=$remote_ip
-      debugMessage "New IPv6: $_new_IPv6 old was: $dns_ip"
+      debugMessage "IPv6 from remote IP check server: $_new_IPv6, IPv4 from DNS: $dns_ip"
       ;;
     *) ;;
-
   esac
 
   if [[ "$remote_ip" == "$dns_ip" ]]; then
     return 0
   else
+    case ${1} in
+    4) infoMessage "New IPv4: $_new_IPv4 old was: $dns_ip";;
+    6) infoMessage "New IPv6: $_new_IPv6 old was: $dns_ip";;
+    esac
     return 1
   fi
 }
@@ -680,6 +724,43 @@ function doUpdates() {
   fi
 }
 
+function ipv6_is_not_working() {
+  curl --ipv6 --head --silent --max-time 1 "$_internet_connectivity_test_server" > /dev/null
+  status_code=$?
+  if [[ $status_code -gt 0 ]]
+  then return 0
+  else return 1
+  fi
+}
+
+function ipv4_is_not_working() {
+  curl --ipv4 --head --silent --max-time 1 "$_internet_connectivity_test_server" > /dev/null
+  status_code=$?
+  if [[ $status_code -gt 0 ]]
+  then return 0
+  else return 1
+  fi
+}
+
+function check_internet_connection() {
+  if [[ $_is_IPv4_enabled == true ]]
+  then
+    if ipv4_is_not_working
+    then
+      _is_IPv4_enabled="false"
+      errorMessage "Your IPv4 internet connection does not work."
+    fi
+  fi
+  if [[ $_is_IPv6_enabled == true ]]
+  then
+    if ipv6_is_not_working
+    then
+      _is_IPv6_enabled="false"
+      errorMessage "Your IPv6 internet connection does not work."
+    fi
+  fi
+}
+
 #################
 ## MAIN method ##
 #################
@@ -707,6 +788,7 @@ function dynb() {
   ## parameters and checks
   handleParameters
   checkDependencies
+  check_internet_connection
 
   if loopMode; then
     while :; do
@@ -726,5 +808,3 @@ function dynb() {
 
 dynb "${@}"
 exit $?
-
-# ] <-- needed because of Argbash