Merge branch 'ent-11770-revisar-plugin-dns' into 'develop'

Error Handling,Validation of IP Input,getopts is used to parse command line...

See merge request artica/pandorafms!6299

pandora_server/util/plugin/dns_plugin.sh

@@ -1,83 +1,115 @@
 #!/bin/bash
 # DNS Plugin Pandora FMS Server plugin
-# (c) Antonio Delgado, Sancho Lerena 2010
 
-# Hint: Use this DNS servers as reference:
+# Default variables
-# Google: 8.8.8.8
+TIMEOUT_DURATION=15
-# Telefonica: 194.179.1.101
-
-function help {
-        echo -e "DNS Plugin for Pandora FMS Plugin server. http://pandorafms.com" 
-        echo " "
-        echo "This plugin is used to check if a specific domain return a specific IP "
-        echo -e "address, and to check how time (milisecs) takes the DNS to answer. \n"
-        echo -e "Syntax:" 
-        echo -e "\t\t-d domain to check"
-        echo -e "\t\t-i IP address to check with domain"
-        echo -e "\t\t-s DNS Server to check"
-        echo -e "\t\t-t Do a DNS time response check instead DNS resolve test"
-        echo -e "Samples:"
-        echo "   ./dns_plugin.sh -d artica.es -i 69.163.176.17 -s 8.8.8.8"
-        echo "   ./dns_plugin.sh -d artica.es -t -s 8.8.8.8"
-        echo ""
-        exit
-}
-
-if [ $# -eq 0 ]
-then
-        help
-fi
-
-TIMEOUT_CHECK=0
-DOMAIN_CHECK=""
 IP_CHECK=""
 DNS_CHECK=""
+DOMAIN_CHECK=""
+TIME_CHECK=0
 
-# Main parsing code
+# Regular expression to validate IP address
-while getopts ":htd:i:s:" optname
+IP_REGEX="^(25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)$"
-  do
+
-    case "$optname" in
+# Function to display help with command-line options
-      "h")
+function show_help {
-                help
+    echo "DNS Plugin for Pandora FMS Plugin server. http://pandorafms.com"
-        ;;
+    echo " "
-      "d")
+    echo "This plugin is used to check if a specific domain returns a specific IP address,"
+    echo "and to check how much time (in milliseconds) it takes the DNS to answer."
+    echo " "
+    echo "Syntax:"
+    echo "    -d domain to check"
+    echo "    -i IP address to check with the domain"
+    echo "    -s DNS Server to check"
+    echo "    -t Do a DNS time response check instead of a DNS resolve test"
+    echo " "
+    echo "Samples:"
+    echo "    ./dns_plugin.sh -d example.com -i 192.168.1.1 -s 8.8.8.8"
+    echo "    ./dns_plugin.sh -d example.com -t -s 8.8.8.8"
+    exit 1
+}
+
+# Function to perform DNS query and get IP addresses
+function do_dns_query {
+    results=$(timeout "${TIMEOUT_DURATION}s" dig "@$DNS_CHECK" +nocmd "$DOMAIN_CHECK" +multiline +answer A)
+    echo "$results"
+}
+
+# Command-line argument processing with getopts
+while getopts ":htd:i:s:" opt; do
+    case "$opt" in
+        d)
             DOMAIN_CHECK=$OPTARG
             ;;
-      "t")
+        i)
-                TIMEOUT_CHECK=1
+            # Validate the provided IP address
-        ;;
+            if [[ $OPTARG =~ $IP_REGEX ]]; then
-      "i")
                 IP_CHECK=$OPTARG
+            else
+                echo "The provided IP address is incorrect: $OPTARG" >&2
+                echo "-1"
+                exit 1
+            fi
             ;;
-      "s")
+        s)
+            # Validate the DNS server IP address
+            if [[ $OPTARG =~ $IP_REGEX ]]; then
                 DNS_CHECK=$OPTARG
+            else
+                echo "The provided DNS server IP address is incorrect: $OPTARG" >&2
+                echo "-1"
+                exit 1
+            fi
+            ;;
+        t)
+            TIME_CHECK=1
             ;;
-
         ?)
-                help
+            show_help
             ;;
-      default)
-                help
-        ;;
-
     esac
 done
 
-if [ -z "$DNS_CHECK" ]
+# Check if all necessary values are provided
-then
+if [ -z "$DOMAIN_CHECK" ] || ([ -z "$IP_CHECK" ] && [ $TIME_CHECK -eq 0 ]) || [ -z "$DNS_CHECK" ]; then
-        help
+    echo "Missing or incomplete arguments." >&2
+    echo "-1"
+    show_help
 fi
 
+# Check if time response check should be performed
+if [ $TIME_CHECK -eq 1 ]; then
+    results=$(do_dns_query)
+    RETURN_TIME=$(echo "$results" | awk '/Query time:/ {print $4}')
+    echo "$RETURN_TIME"
+    exit 0
+fi
 
-results=`dig @$DNS_CHECK +nocmd $DOMAIN_CHECK +multiline +noall +answer A`
+# Check if IP address check should be performed
-targets=`echo "$results"| awk '{print $5}'`
+if [ -n "$IP_CHECK" ]; then
+    results=$(do_dns_query)
+    targets=$(echo "$results" | awk '{print $5}')
 
+    found=0
     for x in $targets; do
         if [ "$x" == "$IP_CHECK" ]; then
-                echo 1
+            found=1
-                exit 0
+            break
         fi
     done
 
-echo 0
+    if [ "$found" -eq 0 ]; then
+        echo "0"
+    else
+        echo "1"
+    fi
+else
+    # Show error if IP to check is not specified
+    echo "No IP to check was specified for the domain: $DOMAIN_CHECK" >&2
+    echo "-1"
+    exit 1
+fi
+
 exit 0
+