#!/bin/bash
#
# Author: Georg Voell - georg.voell@standby.cloud
# Version: @(#)check-port 3.2.1 13.10.2024 (c)2024 Standby.cloud
# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
#
# This script can be used free of charge. Use it as is or customize as needed. It is not guaranteed to be
# error free and you will not be reimbursed for any damage it may cause.
#
#@  Checks if port can be reached over the internet (ingres)
#@
#@Usage: check-port [options] port
#@  Options:
#@    -h, --help           : Displays helptext.
#@    -v, --version        : Displays the version of the script.
#@    -o, --output <string>: Output format: <string> can be "line", "json", "tsv" or "table" (default).
#@  Port: Can be a specific port or a port range e.g. '22-25,80,443' e.g.
#@    80: Test if http port can be reached from outside.
#
# Exit codes:
#  01: Unknown or wrong parameter.
#  02: **curl** not found. This script needs **curl** to perform.
#  03: No internet connection.
#  99: User interrupt.
#
# See also:
#  **check-ip**(1), **convert-number**(1), **install-scripts**(1)
#
# ToDo:
#   Listener check - selinux check - other Firewalls e.g. Mac
#   Getting a list of portnames e.g. http, ssh from Internet (JSON file?)
#   Getting a list of Apps that usese special Ports e.g. Oracle DB Port 1521
#
# Update history:
#
# V 3.0.0 02.05.2020 New version
# V 3.0.1 03.06.2020 Using transfer instead of curl
# V 3.0.2 11.06.2020 Using library
# V 3.0.3 21.05.2023 Using HTTPS instead of HTTP
# V 3.1.0 05.06.2023 New copyright
# V 3.2.0 11.09.2024 New minor version
# V 3.2.1 13.10.2024 Don't use convert-json and jq
#

# Find executable bash library and source it
lib=`which lib.bash 2>/dev/null | sed 's|^no 'lib.bash' in .*||'`
if [ "$lib" != "" ]; then
	source "$lib"
else
	progdir=`dirname "$0"`
	if [ -r "${progdir}/lib.bash" ]; then
		source "${progdir}/lib.bash"
	else
		echo "Unexpected error: Unable to locate bash library 'lib.bash'."
		exit 1
	fi
fi

# Set the Base URL
url="https://ifconfig.co/port"

# Preset
param=""
maxchecks=25		# Maximal number of port checks
formatstr=""		# Print result in table format

# Check parameters: Loop until all parameters are used up
while [ $# -gt 0 ]; do
	pname=${1}
	case "$1" in
		-o | --output)
			shift
			if [ "$1" != "" ]; then
				if [ "$formatstr" = "" ]; then
					formatstr=`echo "$1" | tolower`
					if [ "$formatstr" != "tsv" -a "$formatstr" != "line" -a "$formatstr" != "table" -a "$formatstr" != "json" ]; then
						errstr="Unknown format '$formatstr' after parameter '$pname'. Please choose from 'tsv', 'line', 'table' or 'json'."
					fi
				else
					errstr="Option '$pname' used more then once."
				fi
				shift
			else
				errstr="Please specify a format ('tsv', 'line', 'table' or 'json') after parameter '$pname'."
			fi
			;;
		-v | --version)
			shift
			showversion=true
			;;
		-h | --help)
			shift
			showhelp=true
			;;
		*)
			shift
			paramck=`echo "$pname" | grep '^-'` # Keys don't begin with '-'
			if [ "$paramck" != "" ]; then
				errstr="Unknown option '$pname'."
			else
				if [ "$errstr" = "" ]; then
					if [ "$param" = "" ]; then
						param=`echo "$pname" | tolower`
					else
						errstr="Port was already specified '$param'. Unknown additional parameter: '$pname'."
					fi
				fi
			fi
	esac
done

# Plausibility checks
if [ "$errstr" = "" -a "$param" = "" ]; then
	errstr="No port number given."
else
	if [ "$formatstr" = "" ]; then
		formatstr="table"
	fi
fi

# Display help or error message
DisplayHelp

# Check if he have curl and jq in path
curl=`filecheck -x curl`

if [ "$curl" = "" ]; then
	exitcode=2
	errormsg $exitcode "($progstr) No 'curl' in '$PATH'. Please install first e.g. 'sudo yum -y install curl'."
	exit $exitcode
else
	myip=`get-ip ip`
	if [ "$myip" = "" ]; then
		exitcode=3
		errormsg $exitcode "($progstr) No connection to the Internet. Can't check ports."
		exit $exitcode
	else
		# Convert port range
		convert-number "$param" --max 65535 --padding 5 > $scratchfile
		ports="`head -n $maxchecks $scratchfile | tr '\n' ' '`"

		printf "%s\t%s\t%s\n" "ip" "port" "reachable" > ${scratchfile}.out
		for port in $ports; do
			result=""
			while [ "$result" = "" ]; do
				# Get result from server via curl
				# $curl $curlparam "${url}/$port" -o $scratchfile
				transfer --quiet "${url}/$port" --export $scratchfile
				stat=$?
				
				if [ $stat -eq 0 ]; then
					result=`head -n 1 $scratchfile | grep '^{'`
					if [ "$result" != "" ]; then
						# ip=`grep '"ip":' $scratchfile | cut -d':' -f2- | tr -d '"' | tr -d ' ' | tr -d ','`
						port=`grep '"port":' $scratchfile | cut -d':' -f2 | tr -d '"' | tr -d ' ' | tr -d ','`
						reachable=`grep '"reachable":' $scratchfile | cut -d':' -f2 | tr -d '"' | tr -d ' ' | tr -d ','`
						printf "%s\t%s\t%s\n" "$myip" "/$port/" "/$reachable/" >> ${scratchfile}.out
					fi
				fi
			done
		done
		
		# ToDo: listener check - selinux check - other Firewalls e.g. Mac
		# ToDo: Getting a list of portnames e.g. http, ssh from Internet (JSON file?)
		# ToDo: Getting a list of Apps that usese special Ports e.g. Oracle DB Port 1521
		# ToDo: Check from other ip then public ip
		
		result=`filecheck -sl ${scratchfile}.out`
		if [ "$result" = "${scratchfile}.out" ]; then
			if [ "$formatstr" = "json" ]; then
				print-table --import ${scratchfile}.out --output $formatstr | sed 's|\("contentItems":.*\)|\1,\n  "creator": "'$progstr'"|'
			else
				print-table --import ${scratchfile}.out --output $formatstr
			fi
		fi
	fi
fi

# Cleanup and exit
Cleanup
exit $exitcode