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port scanner for bash
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#!/bin/bash | |
## helpers | |
dec2ip() { | |
local delim ip dec=$@ | |
for e in {3..0} | |
do ip+=${delim}$(((dec>>(8*e))&0xFF)) && delim=. | |
done | |
printf '%s\n' "$ip" | |
} | |
usage() { | |
echo "${0} ip[/mask]:port[-port]" | |
echo "use cidr notation" | |
exit $@ | |
} | |
## checks and init | |
# check: exactly one parameter | |
[ $# == 1 ] || usage 1 | |
# check: parameter format | |
echo "$1" | egrep -q '^(\d+\.){3}\d+(\/\d+)?:\d+(-\d+)?$' || usage 2 | |
# init: proceed to split | |
tgt="$1" | |
cidr=$(echo "${tgt}" | cut -d':' -f1) | |
port=$(echo "${tgt}:" | cut -d':' -f2) | |
plo=$(echo "${port}" | cut -d'-' -f1) | |
phi=$(echo "${port}" | cut -d'-' -f2) | |
mask=$(echo "${cidr}/" | cut -d'/' -f2) | |
ip=$(echo "${cidr}/" | cut -d'/' -f1) | |
eval dip=$(echo "\$(((((((($ip))" | sed 's/\./)<<8\)\+/g') | |
lower=${dip} | |
upper=${dip} | |
if [ ! -z "$mask" ] | |
then | |
bmask=$((2**32-2**(32-mask))) | |
lower=$((dip&bmask)) | |
upper=$(((((1<<32)-1)^bmask)+lower)) | |
fi | |
for hst in $(seq -f %.0f ${lower} ${upper}) | |
do hip=$(dec2ip ${hst}) | |
for ps in $(seq -f %.0f ${plo} ${phi}) | |
do timeout 1 bash -c "echo >/dev/tcp/${hip}/${ps} && echo \"ip ${hip}:${ps} is open\" || echo \"ip ${hip}:${ps} is closed\"" | |
done | |
done |
skip calculation when mask empty
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default cidr mask to /32