2 files changed, 22 insertions, 1 deletions

diff --git a/lib/Smokeping/Master.pm b/lib/Smokeping/Master.pm
index 7024c1a..c2f91ba 100644
--- a/lib/Smokeping/Master.pm
+++ b/lib/Smokeping/Master.pm
@@ -6,6 +6,9 @@ use strict;
 use warnings;
 use Fcntl qw(:flock);
 use Digest::HMAC_MD5 qw(hmac_md5_hex);
+# keep this in sync with the Slave.pm part
+# only update if you have to force a parallel upgrade
+my $PROTOCOL = "2";
 
 =head1 NAME
 
@@ -216,6 +219,13 @@ sub answer_slave {
         print "WARNING: No secret found for slave ${slave}\n";       
         return;
     }
+    my $protcol = $q->param('protocol') || '?';
+    if (not $protocol eq $PROTOCOL){
+        print "Content-Type: text/plain\n\n";
+        print "WARNING: I expected protocol $PROTOCOL and got $protocol from slave ${slave}. I will skip this.\n";
+        return;
+    }
+        
     my $key = $q->param('key');
     my $data = $q->param('data');
     my $config_time = $q->param('config_time');
@@ -237,6 +247,7 @@ sub answer_slave {
         my $config = extract_config $cfg, $slave;    
         if ($config){
             print "Content-Type: application/smokeping-config\n";
+            print "Protocol: $PROTOCOL\n";
             print "Key: ".hmac_md5_hex($config,$secret)."\n\n";
             print $config;
         } else {
diff --git a/lib/Smokeping/Slave.pm b/lib/Smokeping/Slave.pm
index e0e6127..7cc3b7e 100644
--- a/lib/Smokeping/Slave.pm
+++ b/lib/Smokeping/Slave.pm
@@ -8,7 +8,9 @@ use Digest::HMAC_MD5 qw(hmac_md5_hex);
 use LWP::UserAgent;
 use Safe;
 use Smokeping;
-
+# keep this in sync with the Slave.pm part
+# only update if you have to force a parallel upgrade
+my $PROTOCOL = "2";
 
 =head1 NAME
 
@@ -81,6 +83,7 @@ sub submit_results {
         Content => [
             slave => $slave_cfg->{slave_name},
             key  => hmac_md5_hex($data_dump,$slave_cfg->{shared_secret}),
+            protocol => $PROTOCOL,
             data => $data_dump,
             config_time => $cfg->{__last} || 0,
         ],
@@ -88,6 +91,13 @@ sub submit_results {
     if ($response->is_success){
         my $data = $response->content;
         my $key = $response->header('Key');
+        my $protocol = $response->header('Protocol') || '?';
+
+        if ($protocol ne $PROTOCOL){
+            warn "WARNING $slave_cfg->{master_url} sent data with protocol $protocol. Expected $PROTOCOL.";
+            return undef;
+        }
+
         if ($response->header('Content-Type') ne 'application/smokeping-config'){
             warn "$data\n" unless $data =~ /OK/;
             Smokeping::do_debuglog("Sent data to Server. Server said $data");