#!/usr/local/bin/perl -w
#
# Sleuth -- A Simple DNS Checking Tool
#
# (c) 1999--2007 Martin Mares <mj@ucw.cz>
#
# Load configuration file and all modules we need
BEGIN {
if (-f "/usr/local/etc/sleuth.conf") {
require "/usr/local/etc/sleuth.conf";
} else {
require __FILE__ . ".conf";
}
}
use Getopt::Std;
use Net::DNS::Resolver;
# Parse arguments
getopts('vmhp', \%opts) && (@ARGV >= 1 && @ARGV <= 3 || @ARGV == 5) || do {
print <<EOF
Usage: sleuth [-hmpv] <domain> [<server> [<server-IP> [<secondary> <secondary-ip>]]]
-h Produce HTML output
-m Produce machine-readable output
-p Private network mode (avoid public accessibility checks)
-v Be verbose
EOF
;
exit 1;
};
$domain = norm_name($ARGV[0]);
$mode_submit = @ARGV == 5;
$check_ns = defined($ARGV[1]) ? norm_name($ARGV[1]) : "";
$check_ns_ip = defined($ARGV[2]) ? $ARGV[2] : "";
$our_name = defined($ARGV[3]) ? norm_name($ARGV[3]) : "";
$our_ip = defined($ARGV[4]) ? $ARGV[4] : "";
$verbose = $opts{"v"};
$private = $opts{"p"};
if ($opts{"m"}) { $output = \&plain_output; }
elsif ($opts{"h"}) { $output = \&html_output; }
else { $output = \&fancy_output; }
# Initialize reliable resolver using our local nameserver.
$rres = new Net::DNS::Resolver;
$rres->defnames(0);
$rres->dnsrch(0);
$rres->debug(0);
# FIXME: Net::DNS doesn't implement persistent vc's yet
#$rres->usevc(1);
#$rres->stayopen(1);
# And do the checks...
info("Starting zone checks for $domain");
$err_cnt = 0;
$warn_cnt = 0;
if ($mode_submit) {
check_zone_name();
check_submit();
check_ns_sanity();
check_zone() || msg("noserv", "No zone data available, giving up");
} else {
check_zone_name();
check_zone_basics();
$global_okay = 0;
foreach my $nsvr (@check_servers) {
$nsvr =~ /(.*) = (.*)/;
$check_ns = $1;
$check_ns_ip = $2;
info("Decided to use $check_ns ($check_ns_ip) for zone check");
init_resolver($check_ns_ip);
check_ns_sanity();
if (check_zone()) {
$global_okay = 1;
last;
}
}
$global_okay || msg("noserv", "No name server available for checking");
}
info("Summary: $err_cnt errors, $warn_cnt warnings");
exit ($err_cnt > 0);
# Output of messages
sub plain_output {
my $type = shift @_;
my $msg = shift @_;
my $ref = shift @_;
$ref = (defined $ref) ? " [RFC$ref]" : "";
print "$type $msg$ref\n";
}
sub fancy_output {
my $type = shift @_;
my $msg = shift @_;
my $ref = shift @_;
my $mmsg;
my %msg_types = %{{ 'W' => '### Warning: ',
'E' => '### Error: ',
'F' => '### Fatal error: ',
'>' => ' ',
'*' => ' -> ',
'.' => ''
}};
$mmsg = $msg_types{$type};
$ref = (defined $ref) ? " [RFC$ref]" : "";
print "$mmsg$msg$ref\n";
}
sub html_output {
my $type = shift @_;
my $msg = shift @_;
my $ref = shift @_;
if ($type =~ /[>*]/) {
if (!$is_pre) { print "<PRE>"; $is_pre=1; }
print " ", ($type eq ">") ? "" : "-> ", $msg;
} else {
if (!defined $is_pre) { print "<P>"; $is_pre=0; }
elsif ($is_pre) { print "</PRE>"; $is_pre=0; }
else { print "<BR>"; }
if ($type =~ /[WEF]/) {
my $map = {'W'=>'Warning', 'E'=>'Error', 'F'=>'Fatal error'};
print "<em class=msg$type>### ", ${$map}{$type}, ": $msg", "</em>";
} elsif ($type eq "." && $msg =~ /^Summary: /) {
if ($msg !~ / 0 errors,/) { $msg =~ s/ (\d+) errors,/ <em class=msgE>$1 errors,<\/em>/; }
if ($msg !~ / 0 warnings/) { $msg =~ s/ (\d+) warnings/ <em class=msgW>$1 warnings<\/em>/; }
print $msg;
} else { print $msg; }
if (defined $ref) {
my $comma = 0;
print " [see";
foreach my $z (split(/,\s*/, $ref)) {
my ($rfc, $url);
$comma++ && print ",";
if ($z =~ /(\d+)\/(.*)/) {
$rfc = "$1:$2";
$url = eval $rfc_sec_url;
} elsif ($z =~ /(\d+)/) {
$rfc = "$1";
$url = eval $rfc_url;
} else { die "Bad RFC reference"; }
print " <A HREF=\"$url\">RFC$rfc</A>";
}
print " for details]";
}
}
print "\n";
}
sub msg {
my ($id, $msg, $ref) = @_;
defined $sev{$id} or die "Internal error: unknown message code <$id>";
my $type = $sev{$id};
return if $type eq "" || $type eq "0";
if (!$verbose) {
if ($type =~ /[.>]/) { @msg_buffer = (); }
elsif ($type =~ /[EWF]/ && @msg_buffer) {
foreach my $m (@msg_buffer) { &{$output}('*', $m); }
@msg_buffer = ();
} elsif ($type eq '*') { push @msg_buffer, $msg; return; }
}
&{$output}($type, $msg, $ref);
if ($type eq "E") { $err_cnt++; }
elsif ($type eq "W") { $warn_cnt++; }
elsif ($type eq "F") { exit 1; }
}
sub info { msg('.', shift @_); }
sub rr_echo { my $rr=shift @_; msg('*', $rr->string); }
# Our interface to the resolver
sub try_resolve {
my $rver = shift @_;
my $name = shift @_;
my $type = shift @_;
my $need_aa = shift @_;
my $q = $rver->send($name, $type, "IN") or do {
msg("reserr", $res->errorstring);
return undef;
};
my $hdr = $q->header;
$hdr->tc && msg("dnserr", "Truncated response received");
my $rc = $hdr->rcode;
$rc eq "NXDOMAIN" and return undef;
$rc eq "NOERROR" or do { msg("reserr", "Unable to resolve $name: $rc"); return undef; };
$hdr->ancount || return undef;
!$need_aa || $hdr->aa || msg("needaa", "Answer is not authoritative");
return $q;
}
sub resolve {
my $name = shift @_;
my $type = shift @_;
my $allow_cnames = shift @_;
my $check_rev = shift @_;
my $need_aa = shift @_;
my @answer;
check_name($name) || return ();
if ($cache{$name}{$type}) {
@answer = @{$cache{$name}{$type}};
} else {
my $q = try_resolve($res, $name, $type, $need_aa);
$q || return ();
@answer = $q->answer;
$cache{$name}{$type} = \@answer;
}
my @result = ();
my $cname_cnt = 0;
foreach my $r (@answer) {
rr_echo($r);
$r->class ne "IN" and next;
if ($r->type eq "A") {
# If it's an A record, automatically check it maps back.
$check_rev && check_reverse($r->name, $r->address, "");
}
if ($r->type eq "CNAME") {
if (!$allow_cnames) { msg("pcname", "DNS records must not point to CNAMEs", "1034/3.6, 1912/2.4, 2181/10.2-3"); }
if ($cname_cnt) { msg("rcname", "CNAMEs must not point to CNAMEs", "1034/3.6, 1912/2.4, 2181/10.2-3"); }
$cname_cnt++;
}
if ($r->type eq $type || $type eq "ANY") {
# We shouldn't check minimum TTL here as we might have got a cached value
($r->ttl > 4*7*86400) && msg("suspttl", "Suspicious TTL value");
push @result, $r;
} elsif ($r->type ne "CNAME") {
msg("unxtype", "Expected $type, got " . $r->type);
}
}
return @result;
}
# Normalization and comparison of host names and IP addresses
sub same_ipa {
my $x = shift @_;
my $y = shift @_;
return $x eq $y;
}
sub norm_name {
my $n = shift @_;
$n =~ s/\.$//;
$n =~ tr[A-Z][a-z];
return $n;
}
sub same_name {
my $x = shift @_;
my $y = shift @_;
return norm_name($x) eq norm_name($y);
}
# Checks of reverse mapping
sub reverse_name {
my $addr = shift @_;
$addr =~ /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/ or fatal("Unable to parse IP address $addr");
return "$4.$3.$2.$1.in-addr.arpa.";
}
sub check_reverse {
my $name = shift @_;
my $addr = shift @_;
my $allow_domain = shift @_;
my $rn = reverse_name($addr);
my $maps_back = "";
my $found_exact = 0;
my $warned = 0;
$did_reverse_check{$addr} && return;
$did_reverse_check{$addr} = 1;
($addr =~ /^(192\.168|10|172\.(1[6-9]|2\d|3[01]))\./) && !$private &&
msg("privadr", "Private addresses shouldn't occur in public zones", "1918");
foreach my $q (resolve("$rn", "PTR", 1, 0)) {
my $dname = $q->ptrdname;
if (same_name($dname, $name)) { $found_exact++; }
else {
my $matched = 0;
foreach my $a (resolve("$dname", "A", 1, 0)) {
same_ipa($a->address, $addr) && ($matched = 1);
}
if (!$matched) {
$warned = 1;
msg("badrev", "$name maps to $dname which doesn't point back", "1912/2.1");
}
$maps_back = $dname;
}
}
if (!$found_exact) {
if ($maps_back eq "") { msg("norev", "$name ($addr) has no reverse record", "1912/2.1"); }
elsif ($name ne $allow_domain && !$warned) {
msg("inexrev", "$addr for $name points back to $maps_back", "1912/2.1");
}
}
}
# Check of e-mail address
sub check_email {
my $e = shift @_;
$e =~ /@/ && do { msg("soamail", "'\@' in e-mail addresses should be encoded as '.'", "1912/2.2"); return; };
$e =~ /^(([^.\\]|\\.)+)\.(.*)$/ || do { msg("soamail", "Invalid e-mail address syntax"); return; };
my $user = $1;
my $host = norm_name($3);
$user =~ s/\\(.)/$1/g;
$e = "$user\@$host";
info("Hostmaster e-mail address is $e");
if (my @mx = resolve($host, "MX", 1, 0)) {
foreach my $r (@mx) {
resolve($r->exchange, "A", 0, 1) or msg("soammxa", "No A record for MX " . $r->exchange);
}
} elsif (resolve($host, "A", 1, 0)) {
msg("soaamx", "MX records should be used for mail routing");
} else {
msg("soammx", "No MX record for $host");
}
}
# Check of name syntax
sub check_name {
my $n = shift @_;
$n =~ s/\.$//;
if ($n !~ /[^0-9.]/) {
if ($n =~ /^(\d+\.){3}\d+$/) { msg("ipaname", "IP address found instead of name", "1912/2.1"); }
else { msg("alldig", "All-digit names are not allowed", "1912/2.1"); }
return 0;
}
if ($n =~ /^(.*)\.in-addr\.arpa$/i) {
my $m = $1;
if ($m !~ /^(\d+-\d+|\d+)(\/\d+)?(\.(\d+-\d+|\d+)(\/\d+)?)*$/) {
msg("badrn", "Invalid name of reverse domain $n", "1035/3.5"); return 0;
} elsif ($m =~ /(^|\.|-|\/)0[0-9]/) {
msg("badrn", "Reverse names should not contain leading zeros", "1035/3.5"); return 0;
}
}
$n =~ s/^\*\.//;
foreach my $q (split(/\./, $n)) {
if ($q eq "") {
msg("badname", "Name $n has empty components", "1912/2.1"); return 0;
} elsif ($reverse ? ($q !~ /^[0-9a-zA-Z_\/-]*$/) : ($q !~ /^[0-9a-zA-Z_-]*$/)) {
msg("badname", "Name $n contains invalid characters", "1912/2.1"); return 0;
}
}
return 1;
}
# Generic checks of nameserver configuration
sub check_ns_sanity {
# Check whether the nameserver is able to resolve its own address forth and back.
info("Checking whether $check_ns knows an A record for its own name");
my $ns_a = 0;
foreach $r (resolve($check_ns, "A", 0, 0)) {
if (same_ipa($check_ns_ip, $r->address)) { $ns_a++; }
}
$ns_a || msg("selfa", "no matching A record found");
info("Checking whether $check_ns is able to reverse-map its own IP address");
check_reverse($check_ns, $check_ns_ip, "");
# General nameserver functionality checks
if (!$private) {
info("Checking connectivity with other nameservers");
foreach $name (@test_hosts) {
resolve($name, "A", 1, 0) or
msg("recchk", "$check_ns is unable to resolve $name (maybe it's non-recursive)");
}
}
info("Checking mapping of localhost");
$res->recurse(0);
if (@lh = resolve("localhost", "A", 1, 0, 1)) {
(@lh != 1 || !same_ipa($lh[0]->address, "127.0.0.1")) &&
msg("badloc", "Invalid resource records for localhost at $check_ns", "1912/4.1");
} else { msg("nolocal", "$check_ns is unable to resolve localhost", "1912/4.1"); }
resolve("1.0.0.127.in-addr.arpa", "PTR", 1, 0, 1) or msg("revloc", "Reverse mapping of 127.0.0.1 at $check_ns doesn't work", "1912/4.1");
$res->recurse(1);
}
# Zone name checks
sub check_zone_name {
if ($domain =~ /^(.*)\.in-addr\.arpa$/) {
info("Switched to reverse zone check mode");
$reverse = 1;
}
info("Checking zone name");
check_name($domain);
}
# Checks done for zone submission
sub check_submit {
# Test for bogus and forbidden names
($domain =~ /(^|\.)([^.]+)\.([^.]+)$/) || msg("rtoplev", "Registration of top-level domains not supported");
$l2 = $2;
$l1 = $3;
try_resolve($rres, $l1, "SOA") || msg("utoplev", "Top level domain $l1 doesn't exist");
if (length($l2) <= 4 && ($q = try_resolve($rres, $l2, "SOA"))) {
rr_echo($q->answer);
msg("xtoplev", "Second-level domains must not use names of top-level domains");
}
# Test whether our NS is not already authoritative.
info("Checking for zone duplicity for $domain");
init_resolver($our_ip);
$res->recurse(0);
$q = try_resolve($res, $domain, "SOA");
($q && $q->header->aa) && msg("alknown", "$domain already known at $our_name");
# Test whether the NS is authoritative for the zone.
init_resolver($check_ns_ip);
info("Checking for authoritative data for $domain");
$res->recurse(0);
$q = try_resolve($res, $domain, "SOA");
$q || msg("snauth", "SOA record for $domain not found");
$q->header->aa || msg("snauth", "$check_ns is not authoritative for $domain");
$res->recurse(1);
# Check number of name servers and whether we are one of them.
info("Checking list of nameservers");
@q = resolve($domain, "NS", 0, 1) or msg("missns", "No NS records for $domain found");
@q >= 2 || msg("twons", "Each domain should have at least 2 nameservers", "1912/2.8");
if (defined($our_name)) {
$found_us = 0;
foreach $r (@q) {
same_name($r->nsdname, $our_name) && ($found_us = 1);
}
$found_us || msg("nosecns", "$our_name is not listed in NS records of $domain");
}
}
# Zone transfer and check
sub check_zone {
info("Fetching zone data for $domain");
if (!(@zone = $res->axfr($domain))) {
msg("axfer", "Zone transfer failed");
return 0;
}
info("Parsing zone data");
$rcnt=0;
foreach $r (@zone) {
$records{norm_name($r->name)}{$rcnt++} = $r;
}
info("Checking consistency of zone records");
$seen_localhost = 0;
foreach $name (sort { ($a eq $domain) ? -1 : ($b eq $domain) ? 1 : ($a cmp $b) } keys %records) {
$seen_cname = 0;
$seen_other = 0;
foreach $z (keys %{$records{$name}}) {
$r = $records{$name}{$z};
my $txt = $r->string;
msg(">", $txt);
defined $seen{$txt} && msg("duprec", "Duplicate record");
$seen{$txt} = 1;
check_name($name);
($r->ttl < 3600 || $r->ttl > 4*7*86400) && msg("suspttl", "Suspicious TTL value");
$t = $r->type;
$name =~ /(^|\.)$domain$/ || msg("outzone", "Out-of-zone record");
if ($name =~ /\*/) {
if ($t eq "SRV") {
# Wildcard SRV's are a useful thing
} elsif ($t eq "A" || $t eq "CNAME") {
msg("wildac", "Wildcard A and CNAME records are likely to be very confusing", "1912/2.7");
} else {
msg("wild", "Wildcard names are generally considered bad practice", "1912/2.7");
}
}
if ($reverse) {
my $byte = '(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])';
my $n = $name;
$n =~ s/\.in-addr\.arpa$//;
$rev_ip = "";
if ($n =~ /^($byte(\.$byte){3})$/) {
# Standard reversed IP address names
$rev_ip = join('.', reverse split (/\./, $1));
} elsif ($n =~ /^$byte\.$byte((\.$byte){3})$/ && $1 >= $2) {
# d.net.c.b.a type classless delegation
$rev_ip = join('.', reverse split (/\./, "$1$3"));
} elsif ($n =~ /^$byte\.$byte-$byte((\.$byte){3})$/ && $2 < $3 && $1 >= $2 && $1 <= $3) {
# d.dlow-dhigh.c.b.a type
$rev_ip = join('.', reverse split (/\./, "$1$4"));
} elsif ($n =~ /^$byte\.$byte\/([1-9]\d*)((\.$byte){3})$/ &&
$3 >= 25 && $3 <= 30 && !($2 & ((1 << (32-$3))-1)) && $1 >= $2 && $1 < $2 + (1 << (32-$3))) {
# d.dlow/pxlen.c.b.a type
$rev_ip = join('.', reverse split (/\./, "$1$4"));
} elsif ($n =~ /^($byte-$byte|$byte\/\d+)(\.$byte)+$/ && ($t ne "PTR")) {
# These are the common classless delegation subzones
} elsif ($name eq $domain && $t ne "CNAME" && $t ne "PTR") {
# Additional records for the zone itself
} else {
msg("badrevn", "Reverse zones should contain only reverse names, not $name");
}
if ($t =~ /^(MX|WKS)$/) {
msg("badrevr", "Illegal record in reverse zone");
} elsif ($t eq "A") {
msg("arev", "A records in reverse zones are valid, but considered bad practice", "1912/2.3");
}
} else {
if ($t eq "PTR") {
msg("ptrfwd", "PTR records in forward zones are valid, but considered bad practice");
}
}
if ($t eq "CNAME") {
$seen_cname++;
$d = norm_name($r->cname);
# a.b.c -> a.b.c is wrong
if (same_name($d, $name)) { msg("reccn", "Recursive CNAME", "1034/3.6"); }
else {
# a.b.c -> x.a.b.c and a.b.c -> b.c are probably wrong as well, but not forbidden
if ($name =~ /(^|\.)$d/i || $d =~ /(^|\.)$name/) {
msg("suspcn", "Possibly incorrect overlapping CNAME");
}
if (!resolve($d, "ANY", 0, 1)) {
if ($reverse) {
msg("dangcnr", "Unable to resolve CNAME destination (probably due to classless delegation)");
} else { msg("dangcn", "Unable to resolve CNAME destination"); }
}
}
} else { $seen_other++; }
if (same_name($name, "localhost.$domain")) {
if ($t eq "A" && same_ipa($r->address, "127.0.0.1")) { $seen_localhost++; next; }
else { msg("badloc", "Invalid localhost record"); }
}
if ($t eq "A") {
check_reverse($name, $r->address, $domain);
} elsif ($t eq "NS") {
$dest = $r->nsdname;
resolve($dest, "A", 0, 1) || msg("missa", "Nameserver $dest doesn't have any valid A records");
} elsif ($t =~ /^(MD|MF|MB|MG|MR)$/) {
msg("obsrec", "MD/MF/MB/MG/MR records are obsolete and should not be used");
} elsif ($t eq "SOA") {
(same_name($name, $domain)) || do {
msg("supsoa", "Superfluous SOA record");
next;
};
resolve($r->mname, "A", 0, 1) || msg("soaorg", "No A record for zone origin");
check_email($r->rname);
($r->expire < 2*7*86400 || $r->expire > 4*7*86400) &&
msg("suspexp", "Expire time should be between 2 and 4 weeks", "1912/2.2");
($r->minimum < 3600) && msg("suspmtl", "Suspicious minimum TTL", "2308/4");
} elsif ($t eq "WKS") {
msg("wks", "WKS record is obsolete and should not be used", "1912/2.6.1");
} elsif ($t eq "PTR") {
if (@dd = resolve($r->ptrdname, "A", 0, 0)) {
if ($reverse && $rev_ip ne "") {
$found = 0;
foreach $rr (@dd) {
(same_ipa($rr->address, $rev_ip)) && ($found=1);
}
$found || msg("ptrbada", "No corresponding A record found", "1912/2.4");
}
} else { msg("ptrnoa", "PTR doesn't point to an A record", "1912/2.4"); }
} elsif ($t eq "MX") {
($r->preference >= 0 && $r->preference < 65536) || msg("mxpref", "Invalid MX preference", "1035/3.3.9");
$dest = $r->exchange;
resolve($dest, "A", 0, 1) || msg("missa", "Mail exchanger $dest doesn't have any valid A records", "1035/3.3.9");
} elsif ($t eq "SRV") {
($name =~ /^(\*|_[0-9a-zA-Z]+)\.(\*|_[a-zA-Z]+)\./) || msg("srvnam", "Invalid service name", "2782");
($r->priority >= 0 && $r->priority < 65536) || msg("srvpar", "Invalid SRV preference", "2782");
($r->weight >= 0 && $r->weight < 65536) || msg("srvpar", "Invalid SRV weight", "2872");
($r->port >= 0 && $r->port < 65536) || msg("srvpar", "Invalid SRV port number", "2872");
$r->target eq "" || $r->target eq "." || resolve($r->target, "A", 0, 1) ||
msg("srvdest", "Service provider has no valid A record");
}
}
if ($seen_cname > 1) {
msg("cnclash", "Multiple CNAMEs for one name", "1912/2.4");
} elsif ($seen_cname && $seen_other) {
msg("cnclash", "CNAME is not allowed to coexist with any other data", "1912/2.4");
}
}
return 1;
}
# Initialize resolver library, but point it to the nameserver given
sub init_resolver {
my $name = shift @_;
$res = new Net::DNS::Resolver;
$res->nameservers($name);
$res->recurse(1);
$res->defnames(0);
$res->dnsrch(0);
$res->debug(0);
# FIXME: Net::DNS doesn't implement persistent vc's yet
#$res->usevc(1);
#$res->stayopen(1);
}
# Basic zone checks -- existence, matching SOA versions and lame delegations
# returns @check_servers
sub check_zone_basics {
my $prefer_origin;
# In case check_ns is given, use it for initial checks, else use our local nameserver
if ($check_ns ne "") {
if ($check_ns_ip eq "") {
info("Resolving name-server address");
$res = $rres;
my @ips = resolve($check_ns, "A", 0, 0) or msg("nonsa", "$check_ns has no A record");
$check_ns_ip = $ips[0]->address;
}
$prefer_origin = $check_ns;
@check_servers = ( "$check_ns = $check_ns_ip" );
init_resolver($check_ns_ip);
$rres = $res; # This one will be the reference
} else {
$res = $rres;
@check_servers = ();
}
info("Checking existence of zone");
resolve($domain, "CNAME", 1, 0) && msg("zcname", "$domain is a CNAME");
my @soa = resolve($domain, "SOA", 0, 0) or msg("znexist", "$domain doesn't exist");
my $real_origin = norm_name($soa[0]->mname);
defined $prefer_origin || ($prefer_origin = $real_origin);
info("Checking NS records");
my @ns = resolve($domain, "NS", 0, 0) or msg("missns", "$domain has no NS records");
(@ns >= 2) || msg("twons", "Each domain should have at least 2 nameservers", "1912/2.8");
@ns = map { norm_name($_->nsdname) } @ns;
my $nsnames = join(':', sort { $a cmp $b } @ns);
my %nshash;
foreach $r (@ns) { $nshash{$r} = 1; }
if (!defined $nshash{$real_origin}) { msg("ornotns", "Origin server $real_origin not listed in NS records"); }
delete $nshash{$prefer_origin};
@ns = keys %nshash;
unshift @ns, $prefer_origin;
info("Checking nameserver authority and synchronization");
my $psoa;
foreach $n (@ns) {
my @nips;
$res = $rres;
if (!(@nips = resolve($n, "A", 0, 1))) {
msg("missa", "Nameserver $n doesn't have any valid A records");
next;
}
my $nip = $nips[0]->address;
info("Probing name server $n ($nip)");
init_resolver($nip);
$res->recurse(0);
my $q = try_resolve($res, $domain, "SOA");
$res->recurse(1);
$q && $q->header->aa || do { msg("lamer", "Lame delegation of $domain to $n", "1912/2.8"); next; };
my @ss = resolve($domain, "SOA", 0, 0);
if (!@ss) { msg("lamer", "Lame delegation of $domain to $n", "1912/2.8"); next; }
my $ss = $ss[0];
if ($check_ns eq "") { push @check_servers, "$n = $nip"; }
if (defined $psoa) {
my $delta = $psoa->serial - $ss->serial;
($delta >= 0x80000000) && ($delta -= 0x80000000);
($delta <= -0x80000000) && ($delta += 0x80000000);
if ($delta > 0) { msg("oodsec", "$n has out of date data for $domain"); }
elsif ($delta < 0) { msg("oodsec", "$n has newer data for $domain than zone origin"); }
if ($psoa->mname ne $ss->mname ||
$psoa->rname ne $ss->rname ||
$psoa->refresh != $ss->refresh ||
$psoa->retry != $ss->retry ||
$psoa->expire != $ss->expire ||
$psoa->minimum != $ss->minimum) {
msg("oodsoa", "$n lists different SOA parameters than zone origin");
}
} else { $psoa = $ss; }
my $nsb = join(':', sort { $a cmp $b } map { $_->nsdname } resolve($domain, "NS", 0, 0));
same_name($nsnames,$nsb) || msg("diffns", "Different set of NS records reported ($nsb)");
}
# info("Continuing zone checks on " . join("/", @check_servers));
}
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