#!/bin/bash

while read host
do

#verify that the host is up
#/usr/sbin/ping $host -n 1 > /dev/null 2>&1
ping -c 1 $host > /dev/null 2>&1

#if it is up, then extract the banners
if [[ $? -ne 0 ]]
then
	echo "HOST: $host INACCESSIBLE"
else
	unset host_name

	host_name=$(nslookup $host | while read a b
		do
			if [[ "$a" == "Name:" ]]
			then
				echo $b
			fi
		done)

	if [[ -z "$host_name" ]]
	then
		host_name=$host
	fi


	######get the telnet banner

	osbanner=$(
	(
		echo set escape +
		echo open $host
		sleep 5
		echo +
		echo quit
	) | telnet 2>/dev/null |
		egrep -v '(^telnet|^Connected|^Escape|^Local|^login)' |
		tr -d '[:cntrl:]' )

	echo -e "HOST: $host_name\t$osbanner"


	######examine the SMTP banner
	port=25 #most likely sendmail
	unset banner25

	exec 3<>/dev/tcp/$host/$port

	if [[ $? -ne 0 ]]
	then
		echo -e "\tSMTP: NULL"
	else
		while read a b c
		do
			case $a in
			220*)
				#remove "^220 host" and ";date$" from sendmail
				banner25=${c%;*}

				if [[ -z "$banner25" && -n "$a" ]] #not sendmail
				then
					banner25="$a $b $c"
				fi

				echo quit >&3
				break
				;;
			esac
		done <&3

		if [[ -n "$banner25" ]]
		then
			echo -e "\tSMTP: $banner25"
		fi
	fi


	######examine the FTP banner
	port=21
	unset banner21

	exec 3<>/dev/tcp/$host/$port

	if [[ $? -ne 0 ]]
	then
		echo -e "\tFTP: NULL"
	else
		while read a b c
		do
			case $a in
			220*)
				if [[ "$host" = "$b" || "$host_name" = "$b" ||
					${host_name%%.*} = "$b" ]]
				then
					#suppress redundant host display
					banner21=${c}
				else
					if [[ -n "$b" && -n "$c" ]]
					then
						banner21="${b} ${c}"
					fi
				fi

				echo quit >&3
				break
				;;
			esac
		done <&3

		if [[ -n "$banner21" ]]
		then
			echo -e "\tFTP: $banner21"
		fi
	fi


	######examine the SSH banner
	port=22
	unset banner22

	exec 3<>/dev/tcp/$host/$port

	if [[ $? -ne 0 ]]
	then
		echo -e "\tSSH: NULL"
	else
		read banner22 <&3
		echo quit >&3

		if [[ -n "$banner22" ]]
		then
			echo -e "\tSSH: $banner22"
		fi
	fi
fi

done