# $Id: loc2earth.fcgi 1811 2020-10-05 08:24:23Z willem $
use strict;
use warnings;
# if you don't have FastCGI support, comment out this line and the two lines
# later in the script with "NO FCGI" comments
use CGI::Fast qw(:standard);
# and uncomment the following instead.
#use CGI qw(:standard);
use Net::DNS '0.08'; # LOC support in 0.08 and later
$res = Net::DNS::Resolver->new();
@samplehosts= ('www.kei.com',
'www.ndg.com.au',
'gw.alink.net',
'quasar.inexo.com.br',
'hubert.fukt.hk-r.se',
'sargent.cms.dmu.ac.uk',
'thales.mathematik.uni-ulm.de');
while ( CGI::Fast->new ) { # NO FCGI -- comment out this line
print header(-Title => "RFC 1876 Resources: Earth Viewer Demo");
# reinitialize these since FastCGI would keep them around otherwise
@addrs = @netnames = ();
$foundloc = 0;
print '
RFC 1876 Resources: Earth Viewer Demo
';
print p("This is a quick & dirty demonstration of the use of the",
a({-href => 'http://www.dimensional.com/~mfuhr/perldns/'},
'Net::DNS module'),"and the",
a({-href =>
'http://www-genome.wi.mit.edu/ftp/pub/software/WWW/cgi_docs.html'},
'CGI.pm library'), "to write LOC-aware Web applications.");
print startform("GET");
print p(strong("Hostname"),textfield(-name => host, -size => 50));
print p(submit, reset), endform;
if (param('host')) {
($host = param('host')) =~ s/\s//g; # strip out spaces
# check for numeric IPs and do reverse lookup to get name
if ($host =~ m/^\d+\.\d+\.\d+\.\d+$/) {
$query = $res->query($host);
if (defined ($query)) {
foreach my $ans ($query->answer) {
if ($ans->type eq "PTR") {
$host = $ans->ptrdname;
}
}
}
}
$query = $res->query($host,"LOC");
if (defined ($query)) { # then we got an answer of some sort
foreach my $ans ($query->answer) {
if ($ans->type eq "LOC") {
&print_loc($ans->rdatastr);
$foundloc++;
} elsif ($ans->type eq "CNAME") {
# XXX should follow CNAME chains here
}
}
}
if (!$foundloc) { # try the RFC 1101 search bit
$query = $res->query($host,"A");
if (defined ($query)) {
foreach my $ans ($query->answer) {
if ($ans->type eq "A") {
push(@addrs,$ans->address);
}
}
}
if (@addrs) {
checkaddrs:
foreach my $ipstr (@addrs) {
$ipnum = unpack("N",pack("CCCC",split(/\./,$ipstr,4)));
($ip1) = split(/\./,$ipstr);
if ($ip1 >= 224) { # class D/E, treat as host addr
$mask = 0xFFFFFFFF;
} elsif ($ip1 >= 192) { # "class C"
$mask = 0xFFFFFF00;
} elsif ($ip1 >= 128) { # "class B"
$mask = 0xFFFF0000;
} else { # class A
$mask = 0xFF000000;
}
$oldmask = 0;
while ($oldmask != $mask) {
$oldmask = $mask;
$querystr =
join(".", reverse (unpack("CCCC",pack("N",$ipnum & $mask))))
. ".in-addr.arpa";
$query = $res->query($querystr,"PTR");
if (defined ($query)) {
foreach my $ans ($query->answer) {
if ($ans->type eq "PTR") {
# we want the list in LIFO order
unshift(@netnames,$ans->ptrdname);
}
}
$query = $res->query($querystr,"A");
if (defined ($query)) {
foreach my $ans ($query->answer) {
if ($ans->type eq "A") {
$mask = unpack("L",pack("CCCC",
split(/\./,$ans->address,4)));
}
}
}
}
}
if (@netnames) {
foreach my $network (@netnames) {
$query = $res->query($network,"LOC");
if (defined ($query)) {
foreach my $ans ($query->answer) {
if ($ans->type eq "LOC") {
&print_loc($ans->rdatastr);
$foundloc++;
last checkaddrs;
} elsif ($ans->type eq "CNAME") {
# XXX should follow CNAME chains here
}
}
}
}
}
}
}
}
if (!$foundloc) {
print hr,p("Sorry, there appear to be no LOC records for the",
"host $host in the DNS.");
}
}
print hr,p("Some hosts with LOC records you may want to try:"),
"\n- ",join("\n
- ",@samplehosts),"
";
print '
Christopher Davis
<ckd@kei.com>
';
} # NO FCGI -- comment out this line
sub print_loc {
local($rdata) = @_;
($latdeg,$latmin,$latsec,$lathem,
$londeg,$lonmin,$lonsec,$lonhem) = split (/ /,$rdata);
print hr,p("The host $host appears to be at",
"${latdeg}°${latmin}'${latsec}\" ${lathem}",
"latitude and ${londeg}°${lonmin}'${lonsec}\"",
"${lonhem} longitude according to the DNS.");
$evurl = ("http://www.fourmilab.ch/cgi-bin/uncgi/Earth?" .
"lat=${latdeg}d${latmin}m${latsec}s&ns=" .
(($lathem eq "S")?"lSouth":"lNorth") .
"&lon=${londeg}d${lonmin}m${lonsec}s&ew=" .
(($lonhem eq "W")?"West":"East") .
"&alt=");
print "Generate an Earth Viewer image from ";
foreach my $alt (49, 204, 958, 35875) {
print ('',
$alt,'km ');
}
return print " above this point
";
}