mirror of
https://github.com/pi-hole/dnsmasq.git
synced 2025-12-19 10:18:25 +00:00
New version of contrib/reverse-dns
This commit is contained in:
Simon Kelley
@@ -1,18 +1,18 @@
|
||||
Hi.
|
||||
The script reads stdin and replaces all IP addresses with names before
|
||||
outputting it again. IPs from private networks are reverse looked up
|
||||
via dns. Other IP adresses are searched for in the dnsmasq query log.
|
||||
This gives names (CNAMEs if I understand DNS correctly) that are closer
|
||||
to the name the client originally asked for then the names obtained by
|
||||
reverse lookup. Just run
|
||||
|
||||
To translate my routers netstat-nat output into names that actually talk
|
||||
to me I have started writing to simple shell scripts. They require
|
||||
netstat -n -4 | ./reverse_replace.sh
|
||||
|
||||
to see what it does. It needs
|
||||
|
||||
log-queries
|
||||
log-facility=/var/log/dnsmasq.log
|
||||
|
||||
to be set. With
|
||||
|
||||
netstat-nat -n -4 | reverse_replace.sh
|
||||
|
||||
I get retranslated output.
|
||||
|
||||
Sincerely,
|
||||
Joachim
|
||||
in the dnsmasq configuration.
|
||||
|
||||
The script runs on debian (with ash installed) and on busybox.
|
||||
|
||||
|
||||
@@ -1,29 +0,0 @@
|
||||
#!/bin/bash
|
||||
# $Id: reverse_dns.sh 4 2015-02-17 20:14:59Z jo $
|
||||
#
|
||||
# Usage: reverse_dns.sh IP
|
||||
# Uses the dnsmasq query log to lookup the name
|
||||
# that was last queried to return the given IP.
|
||||
#
|
||||
|
||||
IP=$1
|
||||
qmIP=`echo $IP | sed 's#\.#\\.#g'`
|
||||
LOG=/var/log/dnsmasq.log
|
||||
|
||||
IP_regex='^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'
|
||||
|
||||
if ! [[ $IP =~ $IP_regex ]]; then
|
||||
echo -n $IP
|
||||
exit
|
||||
fi
|
||||
|
||||
NAME=`tac $LOG | \
|
||||
grep " is $IP" | head -1 | \
|
||||
sed "s#.* \([^ ]*\) is $qmIP.*#\1#" `
|
||||
|
||||
if [ -z "$NAME" ]; then
|
||||
echo -n $IP
|
||||
else
|
||||
echo -n $NAME
|
||||
fi
|
||||
|
||||
@@ -1,28 +1,125 @@
|
||||
#!/bin/bash
|
||||
# $Id: reverse_replace.sh 4 2015-02-17 20:14:59Z jo $
|
||||
#!/bin/ash
|
||||
# $Id: reverse_replace.sh 18 2015-03-01 16:12:35Z jo $
|
||||
#
|
||||
# Usage e.g.: netstat -n -4 | reverse_replace.sh
|
||||
# Parses stdin for IP4 addresses and replaces them
|
||||
# with names retrieved by reverse_dns.sh
|
||||
# with names retrieved by parsing the dnsmasq log.
|
||||
# This currently only gives CNAMEs. But these
|
||||
# usually tell ou more than the mones from reverse
|
||||
# lookups.
|
||||
#
|
||||
# This has been tested on debian and asuswrt. Plese
|
||||
# report successful tests on other platforms.
|
||||
#
|
||||
# Author: Joachim Zobel <jz-2014@heute-morgen.de>
|
||||
# License: Consider this MIT style licensed. You can
|
||||
# do as you ike, but you must not remove my name.
|
||||
#
|
||||
|
||||
DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
|
||||
DNS=$DIR/reverse_dns.sh
|
||||
LOG=/var/log/dnsmasq.log
|
||||
MAX_LINES=15000
|
||||
|
||||
# sed regex
|
||||
# sed regex do match IPs
|
||||
IP_regex='[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}'
|
||||
# private IP ranges
|
||||
IP_private='\(^127\.\)\|\(^192\.168\.\)\|\(^10\.\)\|\(^172\.1[6-9]\.\)\|\(^172\.2[0-9]\.\)\|\(^172\.3[0-1]\.\)'
|
||||
|
||||
#######################################################################
|
||||
# Find Commands
|
||||
|
||||
HOST=nslookup
|
||||
if type host > /dev/null 2>&1; then
|
||||
# echo "No need for nslookup, host is there"
|
||||
HOST=host
|
||||
fi
|
||||
|
||||
#######################################################################
|
||||
# Functions
|
||||
|
||||
# Use shell variables for an (IP) lookup table
|
||||
create_lookup_table()
|
||||
{
|
||||
# Parse log into lookup table
|
||||
local CMDS="$( tail -"$MAX_LINES" "$LOG" | \
|
||||
grep " is $IP_regex" | \
|
||||
sed "s#.* \([^ ]*\) is \($IP_regex\).*#set_val \2 \1;#" )"
|
||||
|
||||
local IFS='
|
||||
'
|
||||
for CMD in $CMDS
|
||||
do
|
||||
eval $CMD
|
||||
done
|
||||
}
|
||||
|
||||
set_val()
|
||||
{
|
||||
local _IP=$(echo $1 | tr . _)
|
||||
local KEY="__IP__$_IP"
|
||||
eval "$KEY"=$2
|
||||
}
|
||||
|
||||
get_val()
|
||||
{
|
||||
local _IP=$(echo $1 | tr . _)
|
||||
local KEY="__IP__$_IP"
|
||||
eval echo -n '${'"$KEY"'}'
|
||||
}
|
||||
|
||||
dns_lookup()
|
||||
{
|
||||
local IP=$1
|
||||
|
||||
local RTN="$($HOST $IP | \
|
||||
sed 's#\s\+#\n#g' | \
|
||||
grep -v '^$' | \
|
||||
tail -1 | tr -d '\n' | \
|
||||
sed 's#\.$##')"
|
||||
if echo $RTN | grep -q NXDOMAIN; then
|
||||
echo -n $IP
|
||||
else
|
||||
echo -n "$RTN"
|
||||
fi
|
||||
}
|
||||
|
||||
reverse_dns()
|
||||
{
|
||||
local IP=$1
|
||||
|
||||
# Skip if it is not an IP
|
||||
if ! echo $IP | grep -q "^$IP_regex$"; then
|
||||
echo -n $IP
|
||||
return
|
||||
fi
|
||||
|
||||
# Do a dns lookup, if it is a local IP
|
||||
if echo $IP | grep -q $IP_private; then
|
||||
dns_lookup $IP
|
||||
return
|
||||
fi
|
||||
|
||||
local NAME="$(get_val $IP)"
|
||||
|
||||
if [ -z "$NAME" ]; then
|
||||
echo -n $IP
|
||||
else
|
||||
echo -n $NAME
|
||||
fi
|
||||
}
|
||||
|
||||
#######################################################################
|
||||
# Main
|
||||
create_lookup_table
|
||||
|
||||
while read LINE; do
|
||||
if grep --quiet $IP_regex <<< "$LINE"; then
|
||||
IPs=`sed "s#.*\b\($IP_regex\)\b.*#\1 #g" <<< "$LINE"`
|
||||
IPs=($IPs)
|
||||
for IP in "${IPs[@]}"
|
||||
for IP in $(echo "$LINE" | \
|
||||
sed "s#\b\($IP_regex\)\b#\n\1\n#g" | \
|
||||
grep $IP_regex)
|
||||
do
|
||||
NAME=`$DNS $IP`
|
||||
# echo "$NAME is $IP";
|
||||
LINE="${LINE/$IP/$NAME}"
|
||||
NAME=`reverse_dns $IP `
|
||||
# echo "$NAME $IP"
|
||||
LINE=`echo "$LINE" | sed "s#$IP#$NAME#" `
|
||||
done
|
||||
fi
|
||||
echo $LINE
|
||||
done < /dev/stdin
|
||||
done
|
||||
|
||||
|
||||
Reference in New Issue
Block a user