#!/bin/sh
# Copyright (C) 2022 iopsys Software Solutions AB
# Author: AMIN Ben Ramdhane <amin.benramdhane@pivasoftware.com>

. /usr/share/bbfdm/bbf_api

LOG_FILE="/tmp/nslookup.log"

nslookup_launch() {
	address=""
	hostname=$(uci_get_bbf_dmmap dmmap_diagnostics.nslookup.HostName)
	dnsserver=$(uci_get_bbf_dmmap dmmap_diagnostics.nslookup.DNSServer)
	cnt=$(uci_get_bbf_dmmap dmmap_diagnostics.nslookup.NumberOfRepetitions 1)
	[ "$hostname" = "" ] && return
	i=0
	j=0
	success_count=0
	[ -e "${LOG_FILE}" ] && rm ${LOG_FILE}
	while [ $i -lt "$cnt" ]; do
		i=$((i+1))
		nslookup -debug $hostname $dnsserver >>${LOG_FILE} 2>&1
		error_code="$?"
		nxd=$(cat ${LOG_FILE} | grep "NXDOMAIN")
		[ -n "$nxd" ] && { $UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState=Error_DNSServerNotResolved; $UCI_COMMIT_BBF_DMMAP; return; }
		[ "$error_code" != "0" ] && { $UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState=Error_Other; $UCI_COMMIT_BBF_DMMAP; return; }
		echo "++++++++++++++++++++++++++++++" >>${LOG_FILE}
	done

	AnswerType="Authoritative"
	while IFS= read line; do
		[ -z "$line" ] && continue;
		server=$(echo "$line" | tr -d '\t' | tr -d ' ' | grep "Server:" | awk -F':' '{print $2}')
	
		if [ -n "$server" ] && [ "$server" = "0.0.0.0" ]; then
		        status="Error_DNSServerNotAvailable"
		        continue
		elif [ -n "$server" ]; then
		        dns_server_ip=$server
		        continue
		fi

		var=$(echo "$line" | tr -d '\t' | tr -d ' ' | grep "Name:" | awk -F':' '{print $2}')
		[ -n "$var" ] && { HostNameReturned=$var; status="Success"; success_count=$((success_count+1)); continue; }

		var=$(echo "$line" | tr -d '\t' | tr -d ' ' | grep "name=" | awk -F'=' '{print $2}')
		[ -n "$var" ] && { HostNameReturned=$var; status="Success"; address="$hostname"; success_count=$((success_count+1)); continue; }

		var=$(echo "$line" | grep "Address: " | awk -F':' '{print substr($0, index($0,$2))}' | tr -d '\t' | tr -d ' ')
		[ -n "$var" ] && { [ -z "$address" ] && address="$var" || address="$address,$var"; continue; }

		var=$(echo "$line" | grep "completed" | awk -F'in' '{print $2}' | tr -d 'ms:\t ')
		[ -n "$var" ] && { ResponseTime=$var; continue; }

		echo "$line" | grep 'connection timed out' >/dev/null 2>&1 && { AnswerType="None"; status="Error_Timeout"; continue; }
		echo "$line" | grep 'Non-authoritative' >/dev/null 2>&1 && { AnswerType="NonAuthoritative"; continue; }
	
		if echo "$line" | grep '++++++++++++++++++++++' >/dev/null 2>&1; then
			$UCI_ADD_BBF_DMMAP dmmap_diagnostics NSLookupResult
			$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].Status="$status"
			$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].AnswerType="$AnswerType"
			$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].HostNameReturned="$HostNameReturned"
			$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].IPAddresses="$address"
			$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].DNSServerIP="$dns_server_ip"
			$UCI_SET_BBF_DMMAP dmmap_diagnostics.@NSLookupResult[$j].ResponseTime="$ResponseTime"
			j=$((j+1))
			address=""
			AnswerType="Authoritative"
		fi
	done <${LOG_FILE}
	rm -f ${LOG_FILE}
	$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.SuccessCount=$success_count
	$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState=Complete
	$UCI_COMMIT_BBF_DMMAP
}

nslookup_stop_diagnostic() {
	pids=$(pgrep -f nslookup_launch)
	if [ -n "$pids" ]; then
		kill -9 "$pids" >/dev/null 2>&1
		$UCI_SET_BBF_DMMAP dmmap_diagnostics.nslookup.DiagnosticState=None
		$UCI_COMMIT_BBF_DMMAP
	fi
}

if [ "$1" = "run" ]; then
	nslookup_launch
elif [ "$1" = "stop" ]; then
	nslookup_stop_diagnostic
else
	return
fi