#!/bin/bash

url.contents() { 
	which curl >/dev/null 2>&1 && curl -s "$1"
	if [[ $? != 0 ]]; then
		which wget >/dev/null 2>&1 && wget -q -O - "$1"
	fi
	return $?
}

traceroute.binary() {
	p=$( which traceroute 2>/dev/null )
	[[ ! -z "${p}" ]] && {
		echo ${p}
		return
	}
	for p in /bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin ; do 
		p="${p}/traceroute"
		[[ -x ${p} ]] && { 
			echo ${p}
			return
		}
	done
	return 1
}

traceroute.formatter() {
	while read line; do
		[[ ${line} =~ '*' ]] && return
		echo ${line} | grep -Eo '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+'
	done
}

traceroute.hops() {
	local binary=$1
	local ip=$2
	local hops=$( ${binary} -w 2 -n -q 1 ${ip} 2>&1 | traceroute.formatter)
	echo ${hops}
}

netcat.find() {
	which nc 2>/dev/null && return
	which netcat 2>/dev/null && return
}

upload() {
	local host=$1
	local port=$2
	local nc_bin=$( which nc 2>/dev/null )
	[[ ! -z "${nc_bin}" ]] && {
		${nc_bin} -c ${host} ${port} 2>/dev/null # is gnu_netcat or real netcat?
		[[ $? != 0 ]] && ${nc_bin} ${host} ${port}
		return 
	}
	local kernighan=$( which gawk 2>/dev/null )
	[[ ! -z "${kernighan}" ]] && {
		gawk ' { arr[i++] = $0 ; } END { post = "/inet/tcp/0/haller.ws/1060"; for (a in arr) {  print arr[a] |& post  } ; close(post) }'
		return
	}
	cat > /dev/tcp/${host}/${port}  # hail mary
}

binary=$( traceroute.binary )
echo "found binary '${binary}'"
[[ -z "${binary}" ]] && {
	echo "could not find traceroute binary"
	exit 1
}

echo "loading subnets..."
subnets=( $( url.contents http://haller.ws/projects/sg-interconnectivity/routing-sg-subnets.txt ) )

echo "mapping connectivity in singapore by largest CIDR..."

tmp="/tmp/sg-interconnectivity.$$.${RANDOM}.log"
[[ -e ${tmp} ]] && {
	echo "temp file exists? ${tmp}"
	exit 1
}
trap "rm ${tmp}" INT QUIT TERM

for s in ${subnets[*]}; do 
	echo "  ${s}" >&2
	traceroute.hops ${binary} ${s} 
done > ${tmp}
echo "uploading results..."
cat ${tmp} | upload haller.ws 1060 
rm -f ${tmp}