From 7f5c91142bfc46c9b890e8e82e1f3214407c987b Mon Sep 17 00:00:00 2001
From: Steven Schubiger <stsc@refcnt.org>
Date: Sat, 6 Apr 2013 19:20:25 +0200
Subject: Initial commit.

---
 server.cgi | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100755 server.cgi

(limited to 'server.cgi')

diff --git a/server.cgi b/server.cgi
new file mode 100755
index 0000000..f52f3d9
--- /dev/null
+++ b/server.cgi
@@ -0,0 +1,128 @@
+#!/usr/bin/perl
+#
+# Copyright (c) 2013 Michel Ketterle, Steven Schubiger
+#
+# This file is part of distdns.
+#
+# distdns is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# distdns is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with distdns.  If not, see <http://www.gnu.org/licenses/>.
+
+use strict;
+use warnings;
+
+use CGI ();
+use Fcntl ':flock';
+use JSON qw(decode_json encode_json);
+
+my $VERSION = '0.04';
+
+#-----------------------
+# Start of configuration
+#-----------------------
+
+my $json_file    = 'data.json';
+my $session_file = 'session.dat';
+
+#---------------------
+# End of configuration
+#---------------------
+
+my $query = CGI->new;
+
+my @params = qw(netz pc name debug init session);
+my %params;
+
+foreach my $param (@params) {
+    $params{$param} = $query->param($param);
+}
+$params{ip} = $query->remote_addr;
+
+if ($params{debug}) {
+    $SIG{__DIE__} = sub
+    {
+        print $query->header('application/json');
+        print encode_json({ entries => [], error => $_[0] });
+        exit;
+    };
+}
+
+if ($params{init}) {
+    die "Delete server-side $session_file first\n" if -e $session_file;
+
+    open(my $fh, '>', $session_file) or die "Cannot open server-side $session_file for writing: $!\n";
+    print {$fh} "$params{session}\n";
+    close($fh);
+}
+else {
+    open(my $fh, '<', $session_file) or die "Cannot open server-side $session_file for reading: $!\nPerhaps try running --init\n";
+    my $session = do { local $/; <$fh> };
+    chomp $session;
+    close($fh);
+
+    die "Session ID mismatch\n" unless $params{session} eq $session;
+}
+
+my @missing_params = grep { not defined $params{$_} && length $params{$_} } @params;
+if (@missing_params) {
+    my $missing_params = join ', ', map "'$_'", @missing_params;
+    die "Incomplete query: param(s) $missing_params missing or not defined\n";
+}
+
+my %access;
+my $access_file = "$params{netz}.conf";
+
+if (-e $access_file) {
+    open(my $fh, '<', $access_file) or die "Cannot open $access_file for reading: $!\n";
+    while (my $line = <$fh>) {
+        chomp $line;
+        my ($name, $pc) = split /\s*,\s*/, $line;
+        push @{$access{$name}}, $pc;
+    }
+    close($fh);
+}
+else {
+    die "Access file $access_file does not exist\n";
+}
+
+if (exists $access{$params{name}} && grep /^$params{pc}$/i, @{$access{$params{name}}}) {
+    open(my $fh, '+<', $json_file) or die "Cannot open $json_file for read/write: $!\n";
+    flock($fh, LOCK_EX)            or die "Cannot lock $json_file: $!\n";
+
+    my $json = do { local $/; <$fh> };
+
+    my $data = defined $json && length $json ? decode_json($json) : [];
+
+    for (my $i = 0; $i < @$data; $i++) {
+        if ($params{netz} eq $data->[$i]->{netz}
+         && $params{pc}   eq $data->[$i]->{pc}
+         && $params{name} eq $data->[$i]->{name}) {
+            splice @$data, $i--, 1;
+        }
+    }
+    push @$data, { map { $_ => $params{$_} } qw(netz pc name ip) };
+
+    seek($fh, 0, 0)  or die "Cannot seek to start of $json_file: $!\n";
+    truncate($fh, 0) or die "Cannot truncate $json_file: $!\n";
+
+    print {$fh} encode_json($data);
+
+    close($fh);
+
+    my @data = grep $_->{netz} eq $params{netz}, @$data;
+
+    print $query->header('application/json');
+    print encode_json({ entries => \@data, error => undef });
+}
+else {
+    die "Access not permitted\n";
+}
-- 
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