自己建立一个ddns server

Initialize variables

binddir="/var/cache/bind"
etcdir="/etc/bind"

host=myhost; zone=dyn.example.com

Create key

ddns-confgen -r /dev/urandom -s $host.$zone.

ddns-confgen -r /dev/urandom -q -a hmac-md5 -k $host.$zone -s $host.$zone. | tee -a $etcdir/$zone.keys

chown root:bind   $etcdir/$zone.keys
chmod u=rw,g=r,o= $etcdir/$zone.keys

ddns-confgen -r /dev/urandom -q -a hmac-md5 -k $host.$zone -s $host.$zone. | tee -a $etcdir/$zone.keys > $etcdir/key.$host.$zone

chown root:bind   $etcdir/$zone.keys $etcdir/key.*
chmod u=rw,g=r,o= $etcdir/$zone.keys $etcdir/key.*

Configure bind

Create zone file

$ORIGIN .
$TTL  3600 ; 1 hour

dyn.example.com IN SOA  dns-server.example.com. hostmaster.example.com. (
         1 ; serial (start at 1 for a dynamic zone instead of the usual date-based serial)
      3600 ; refresh by secondaries (but they get NOTIFY-ed anyway)
       600 ; retry (every 10 minutes if refresh fails)
    604800 ; expire (slaves remove the record after 1 week if they could not refresh it)
       300 ; minimum ttl for negative answers (5 minutes)
)

$ORIGIN dyn.example.com.
NS      dns-server.example.com.

Edit /etc/bind/named.conf.local

// DDNS keys
include "/etc/bind/dyn.example.com.keys";

// Dynamic zone
zone "dyn.example.com" {
    type master;
    file "/var/cache/bind/dyn.example.com";
    update-policy {
        // allow host to update themselves with a key having their own name
        grant *.dyn.example.com self dyn.example.com.;
    };
};

Reload server config

rndc reload && sleep 3 && grep named /var/log/daemon.log | tail -20

Test

host=myhost; ip=10.11.12.13; zone=dyn.example.com; server=dns-server.example.com; keyfile=$etcdir/key.$host.$zone

echo -e "server $server\n zone $zone.\n update delete $host.$zone.\n update add $host.$zone. 600 A $ip\n send" | nsupdate -k "$keyfile"

cat <<EOF | nsupdate -k $keyfile
server $server
zone $zone.
update delete $host.$zone.
update add $host.$zone. 600 A $ip
update add $host.$zone. 600 TXT "Updated on $(date)"
send
EOF

host -t ANY $host.$zone

myhost.dyn.example.com descriptive text "Update on Tue Jan 1 17:16:03 CET 2013"myhost.dyn.example.com has address 10.11.12.13

… ‘key’ redefined near ‘key’
could not read key from FILENAME.keys.{private,key}: already exists

Usage

#!/bin/sh

server=dns-server.example.com
host=myhost
secret="xBa2pz6ZCGQJ5obmvmp26w==" # copy the right key from $etcdir/$zone.keys

wget -O /dev/null --no-check-certificate "https://$server/ddns/update.cgi?host=$host;secret=$secret"

#!/bin/sh

server=dns-server.example.com
zone=dyn.example.com
host=myhost
secret="xBa2pz6ZCGQJ5obmvmp26w==" # copy the right key from $etcdir/$zone.keys

ip=$(wget -q -O - http://example.com/myip.cgi)

cat <<EOF | nsupdate
server $server
zone $zone.
key $host.$zone $secret
update delete $host.$zone.
update add $host.$zone. 600 A $ip
update add $host.$zone. 600 TXT "Updated on $(date)"
send
EOF

#!/bin/sh
echo "Content-type: text/plain"
echo ""
echo $REMOTE_ADDR

#!/bin/sh

zone=dyn.example.com
host=myname
secret="nBlw18hxipEyMEVUmwluQx=="
router=192.168.81.3

server=$(dig +short -t SOA $zone | awk '{print $1}')

ip=$( snmpwalk -v1 -m RFC1213-MIB -c public $router ipAdEntAddr | awk '!'"/$router/ {print \$4}" )

if [ -z "$ip" ]; then
 echo "Error getting wan ip from $router" 1>&2
 exit 1
fi

oldip=$(dig +short $host.$zone)

if [ "$ip" == "$oldip" ]; then
 logger -t `basename $0` "No IP change for $host.$zone ($ip)"
 exit
fi

cat <<EOF | nsupdate
server $server
zone $zone.
key $host.$zone $secret
update delete $host.$zone.
update add $host.$zone. 600 A $ip
update add $host.$zone. 600 TXT "Updated on $(date)"
send
EOF

logger -t `basename $0` "IP for $host.$zone changed from $oldip to $ip"

Web server update.cgi

#!/usr/bin/perl

## Use nsupdate to update a DDNS zone.

## (This could be done with the Net::DNS module. It
##  would be more portable (Windows, etc.), but also
##  more complicated. So I chose the nsupdate utility
##  that comes with Bind instead.)

# "mi\x40alma.ch", 2013

use strict;

my $VERSION = 0.2;
my $debug = 1;

my $title = "DDNS update";

my $zone     = "dyn.example.com";
my $server   = "localhost";
my $nsupdate = "/usr/bin/nsupdate";

use CGI qw(:standard);

my $q = new CGI;

my $CR = "\r\n";

print $q->header(),
      $q->start_html(-title => $title),
      $q->h1($title);

if (param("debug")) {
    $debug = 1;
};

my $host   = param("host");
my $secret = param("secret");
my $ip     = param("ip") || $ENV{"REMOTE_ADDR"};
my $time   = localtime(time);

foreach ($host, $secret, $ip) {
    s/[^A-Za-z0-9\.\/\+=]//g; # sanitize, just in case...
    unless (length($_)) {
        die "Missing or bad parameters. host='$host', secret='$secret', ip='$ip'\n";
    }
}

my $commands = qq{
server $server
zone $zone.
key $host.$zone $secret
update delete $host.$zone.
update add $host.$zone. 600 A $ip
update add $host.$zone. 600 TXT "Updated by $0 v. $VERSION, $time"
send
};

print $q->p("sending update commands to $nsupdate:"), $CR,
      $q->pre($commands), $CR;

open( NSUPDATE, "| $nsupdate" ) or die "Cannot open pipe to $nsupdate : $!\n";
print NSUPDATE $commands        or die "Error writing to $nsupdate : $!\n";
close NSUPDATE                  or die "Error closing $nsupdate : $!\n";

print $q->p("Done:"), $CR;

my @result = `host -t ANY $host.$zone`;

foreach (@result) {
    print $q->pre($_), $CR;
}

if ($debug) {
# also log received parameters
    my @lines;
    for my $key (param) {
        my @values = param($key);
        push @lines, "$key=" . join(", ", @values);
    }
    warn join("; ", @lines), "\n";
}

print $q->end_html, $CR;

__END__