+++ /dev/null
-#!/usr/bin/perl
-
-# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
-#
-# SPDX-License-Identifier: MPL-2.0
-#
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, you can obtain one at https://mozilla.org/MPL/2.0/.
-#
-# See the COPYRIGHT file distributed with this work for additional
-# information regarding copyright ownership.
-
-#
-# This is the name server from hell. It provides canned
-# responses based on pattern matching the queries, and
-# can be reprogrammed on-the-fly over a TCP connection.
-#
-# The server listens for control connections on port 5301.
-# A control connection is a TCP stream of lines like
-#
-# /pattern/
-# name ttl type rdata
-# name ttl type rdata
-# ...
-# /pattern/
-# name ttl type rdata
-# name ttl type rdata
-# ...
-#
-# There can be any number of patterns, each associated
-# with any number of response RRs. Each pattern is a
-# Perl regular expression.
-#
-# Each incoming query is converted into a string of the form
-# "qname qtype" (the printable query domain name, space,
-# printable query type) and matched against each pattern.
-#
-# The first pattern matching the query is selected, and
-# the RR following the pattern line are sent in the
-# answer section of the response.
-#
-# Each new control connection causes the current set of
-# patterns and responses to be cleared before adding new
-# ones.
-#
-# The server handles UDP and TCP queries. Zone transfer
-# responses work, but must fit in a single 64 k message.
-#
-# Now you can add TSIG, just specify key/key data with:
-#
-# /pattern <key> <key_data>/
-# name ttl type rdata
-# name ttl type rdata
-#
-# Note that this data will still be sent with any request for
-# pattern, only this data will be signed. Currently, this is only
-# done for TCP.
-
-
-use IO::File;
-use IO::Socket;
-use Data::Dumper;
-use Net::DNS;
-use Net::DNS::Packet;
-use strict;
-
-# Ignore SIGPIPE so we won't fail if peer closes a TCP socket early
-local $SIG{PIPE} = 'IGNORE';
-
-# Flush logged output after every line
-local $| = 1;
-
-my $server_addr = "10.53.0.4";
-
-my $localport = int($ENV{'PORT'});
-if (!$localport) { $localport = 5300; }
-
-my $udpsock = IO::Socket::INET->new(LocalAddr => "$server_addr",
- LocalPort => $localport, Proto => "udp", Reuse => 1) or die "$!";
-
-my $tcpsock = IO::Socket::INET->new(LocalAddr => "$server_addr",
- LocalPort => $localport, Proto => "tcp", Listen => 5, Reuse => 1) or die "$!";
-
-print "listening on $server_addr:$localport.\n";
-
-my $pidf = new IO::File "ans.pid", "w" or die "cannot open pid file: $!";
-print $pidf "$$\n" or die "cannot write pid file: $!";
-$pidf->close or die "cannot close pid file: $!";;
-sub rmpid { unlink "ans.pid"; exit 1; };
-
-$SIG{INT} = \&rmpid;
-$SIG{TERM} = \&rmpid;
-
-#my @answers = ();
-my @rules;
-sub handleUDP {
- my ($buf) = @_;
- my $packet;
-
- if ($Net::DNS::VERSION > 0.68) {
- $packet = new Net::DNS::Packet(\$buf, 0);
- $@ and die $@;
- } else {
- my $err;
- ($packet, $err) = new Net::DNS::Packet(\$buf, 0);
- $err and die $err;
- }
-
- $packet->header->qr(1);
- $packet->header->aa(1);
-
- my @questions = $packet->question;
- my $qname = $questions[0]->qname;
- my $qtype = $questions[0]->qtype;
-
- # get the existing signature if any, and clear the additional section
- my $prev_tsig;
- while (my $rr = $packet->pop("additional")) {
- if ($rr->type eq "TSIG") {
- $prev_tsig = $rr;
- }
- }
-
- my $r;
- foreach $r (@rules) {
- my $pattern = $r->{pattern};
- my($dbtype, $key_name, $key_data) = split(/ /,$pattern);
- print "[handleUDP] $dbtype, $key_name, $key_data \n";
- if ("$qname $qtype" =~ /$dbtype/) {
- my $a;
- foreach $a (@{$r->{answer}}) {
- $packet->push("answer", $a);
- }
- if(defined($key_name) && defined($key_data)) {
- # Sign the packet
- print " Signing the response with " .
- "$key_name/$key_data\n";
- my $tsig = Net::DNS::RR->
- new("$key_name TSIG $key_data");
-
- # These kluges are necessary because Net::DNS
- # doesn't know how to sign responses. We
- # clear compnames so that the TSIG key and
- # algorithm name won't be compressed, and
- # add one to arcount because the signing
- # function will attempt to decrement it,
- # which is incorrect in a response. Finally
- # we set request_mac to the previous digest.
- $packet->{"compnames"} = {};
- $packet->{"header"}{"arcount"} += 1;
- if (defined($prev_tsig)) {
- my $rmac = pack('n H*',
- $prev_tsig->mac_size,
- $prev_tsig->mac);
- $tsig->{"request_mac"} =
- unpack("H*", $rmac);
- }
-
- $packet->sign_tsig($tsig);
- }
- last;
- }
- }
- #$packet->print;
-
- return $packet->data;
-}
-
-# namelen:
-# given a stream of data, reads a DNS-formatted name and returns its
-# total length, thus making it possible to skip past it.
-sub namelen {
- my ($data) = @_;
- my $len = 0;
- my $label_len = 0;
- do {
- $label_len = unpack("c", $data);
- $data = substr($data, $label_len + 1);
- $len += $label_len + 1;
- } while ($label_len != 0);
- return ($len);
-}
-
-# packetlen:
-# given a stream of data, reads a DNS wire-format packet and returns
-# its total length, making it possible to skip past it.
-sub packetlen {
- my ($data) = @_;
- my $q;
- my $rr;
-
- my ($header, $offset) = Net::DNS::Header->parse(\$data);
- for (1 .. $header->qdcount) {
- ($q, $offset) = Net::DNS::Question->parse(\$data, $offset);
- }
- for (1 .. $header->ancount) {
- ($rr, $offset) = Net::DNS::RR->parse(\$data, $offset);
- }
- for (1 .. $header->nscount) {
- ($rr, $offset) = Net::DNS::RR->parse(\$data, $offset);
- }
- for (1 .. $header->arcount) {
- ($rr, $offset) = Net::DNS::RR->parse(\$data, $offset);
- }
- return $offset;
-}
-
-# sign_tcp_continuation:
-# This is a hack to correct the problem that Net::DNS has no idea how
-# to sign multiple-message TCP responses. Several data that are included
-# in the digest when signing a query or the first message of a response are
-# omitted when signing subsequent messages in a TCP stream.
-#
-# Net::DNS::Packet->sign_tsig() has the ability to use a custom signing
-# function (specified by calling Packet->sign_func()). We use this
-# function as the signing function for TCP continuations, and it removes
-# the unwanted data from the digest before calling the default sign_hmac
-# function.
-sub sign_tcp_continuation {
- my ($key, $data) = @_;
-
- # copy out first two bytes: size of the previous MAC
- my $rmacsize = unpack("n", $data);
- $data = substr($data, 2);
-
- # copy out previous MAC
- my $rmac = substr($data, 0, $rmacsize);
- $data = substr($data, $rmacsize);
-
- # try parsing out the packet information
- my $plen = packetlen($data);
- my $pdata = substr($data, 0, $plen);
- $data = substr($data, $plen);
-
- # remove the keyname, ttl, class, and algorithm name
- $data = substr($data, namelen($data));
- $data = substr($data, 6);
- $data = substr($data, namelen($data));
-
- # preserve the TSIG data
- my $tdata = substr($data, 0, 8);
-
- # prepare a new digest and sign with it
- $data = pack("n", $rmacsize) . $rmac . $pdata . $tdata;
- return Net::DNS::RR::TSIG::sign_hmac($key, $data);
-}
-
-sub handleTCP {
- my ($buf) = @_;
- my $packet;
-
- if ($Net::DNS::VERSION > 0.68) {
- $packet = new Net::DNS::Packet(\$buf, 0);
- $@ and die $@;
- } else {
- my $err;
- ($packet, $err) = new Net::DNS::Packet(\$buf, 0);
- $err and die $err;
- }
-
- $packet->header->qr(1);
- $packet->header->aa(1);
-
- my @questions = $packet->question;
- my $qname = $questions[0]->qname;
- my $qtype = $questions[0]->qtype;
-
- # get the existing signature if any, and clear the additional section
- my $prev_tsig;
- my $signer;
- while (my $rr = $packet->pop("additional")) {
- if ($rr->type eq "TSIG") {
- $prev_tsig = $rr;
- }
- }
-
- my @results = ();
- my $count_these = 0;
-
- my $r;
- foreach $r (@rules) {
- my $pattern = $r->{pattern};
- my($dbtype, $key_name, $key_data) = split(/ /,$pattern);
- print "[handleTCP] $dbtype, $key_name, $key_data \n";
- if ("$qname $qtype" =~ /$dbtype/) {
- $count_these++;
- my $a;
- foreach $a (@{$r->{answer}}) {
- $packet->push("answer", $a);
- }
- if(defined($key_name) && defined($key_data)) {
- # sign the packet
- print " Signing the data with " .
- "$key_name/$key_data\n";
-
- my $tsig = Net::DNS::RR->
- new("$key_name TSIG $key_data");
-
- # These kluges are necessary because Net::DNS
- # doesn't know how to sign responses. We
- # clear compnames so that the TSIG key and
- # algorithm name won't be compressed, and
- # add one to arcount because the signing
- # function will attempt to decrement it,
- # which is incorrect in a response. Finally
- # we set request_mac to the previous digest.
- $packet->{"compnames"} = {};
- $packet->{"header"}{"arcount"} += 1;
- if (defined($prev_tsig)) {
- my $rmac = pack('n H*',
- $prev_tsig->mac_size,
- $prev_tsig->mac);
- $tsig->{"request_mac"} =
- unpack("H*", $rmac);
- }
-
- $tsig->sign_func($signer) if defined($signer);
- $packet->sign_tsig($tsig);
- $signer = \&sign_tcp_continuation;
-
- my $copy =
- Net::DNS::Packet->new(\($packet->data));
- $prev_tsig = $copy->pop("additional");
- }
- #$packet->print;
- push(@results,$packet->data);
- $packet = new Net::DNS::Packet(\$buf, 0);
- $packet->header->qr(1);
- $packet->header->aa(1);
- }
- }
- print " A total of $count_these patterns matched\n";
- return \@results;
-}
-
-# Main
-my $rin;
-my $rout;
-for (;;) {
- $rin = '';
- vec($rin, fileno($tcpsock), 1) = 1;
- vec($rin, fileno($udpsock), 1) = 1;
-
- select($rout = $rin, undef, undef, undef);
-
- if (vec($rout, fileno($udpsock), 1)) {
- printf "UDP request\n";
- my $buf;
- $udpsock->recv($buf, 512);
- } elsif (vec($rout, fileno($tcpsock), 1)) {
- my $conn = $tcpsock->accept;
- my $buf;
- for (;;) {
- my $lenbuf;
- my $n = $conn->sysread($lenbuf, 2);
- last unless $n == 2;
- my $len = unpack("n", $lenbuf);
- $n = $conn->sysread($buf, $len);
- last unless $n == $len;
- }
- sleep(1);
- $conn->close;
- }
-}
projects / thirdparty / bind9.git / commitdiff
