From 0cfae8f77ee8efcf7fc0ff6086699ef09540ee81 Mon Sep 17 00:00:00 2001
From: garnier-quentin <garnier.quentin@gmail.com>
Date: Sun, 30 Dec 2018 12:36:40 +0100
Subject: [PATCH] + WIP snmp-autoreduce option

---
 centreon/plugins/snmp.pm | 83 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 74 insertions(+), 9 deletions(-)

diff --git a/centreon/plugins/snmp.pm b/centreon/plugins/snmp.pm
index 27683b76c..a95cddff3 100644
--- a/centreon/plugins/snmp.pm
+++ b/centreon/plugins/snmp.pm
@@ -53,6 +53,7 @@ sub new {
                   "maxrepetitions:s"          => { name => 'maxrepetitions', default => 50 },
                   "subsetleef:s"              => { name => 'subsetleef', default => 50 },
                   "subsettable:s"             => { name => 'subsettable', default => 100 },
+                  "snmp-autoreduce"           => { name => 'snmp_autoreduce' },
                   "snmp-force-getnext"        => { name => 'snmp_force_getnext' },
                   "snmp-username:s"           => { name => 'snmp_security_name' },
                   "authpassphrase:s"          => { name => 'snmp_auth_passphrase' },
@@ -138,6 +139,54 @@ sub load {
     push @{$self->{oids_loaded}}, @{$options{oids}};
 }
 
+sub autoreduce_table {
+    my ($self, %options) = @_;
+    
+    return 1 if (defined($self->{snmp_force_getnext}) || $self->is_snmpv1());
+    if ($self->{snmp_params}->{Retries} > 1) {
+        $self->{snmp_params}->{Retries} = 1;
+        $self->connect();
+    }
+    return 1 if (${$options{repeat_count}} == 1);
+    ${$options{repeat_count}} = int(${$options{repeat_count}} / 2);
+    
+    return 0;
+}
+
+sub autoreduce_leef {
+    my ($self, %options) = @_;
+    
+    if ($self->{snmp_params}->{Retries} > 1) {
+        $self->{snmp_params}->{Retries} = 1;
+        $self->connect();
+    }
+    
+    return 1 if ($self->{subsetleef} == 1);
+    $self->{subsetleef} = int($self->{subsetleef} / 2);
+    
+    my $array_ref = [];
+    my $subset_current = 0;
+    my $subset_construct = [];
+    foreach ([@{$options{current}}, @{$self->{array_ref_ar}}]) {
+        foreach my $entry (@$_) {
+            push @$subset_construct, [$entry->[0], $entry->[1]];
+            $subset_current++;
+            if ($subset_current == $self->{subsetleef}) {
+                push @$array_ref, \@$subset_construct;
+                $subset_construct = [];
+                $subset_current = 0;
+            }
+        }
+    }
+    
+    if ($subset_current) {
+        push @$array_ref, \@$subset_construct;
+    }
+
+    $self->{array_ref_ar} = $array_ref;
+    return 0;
+}
+
 sub get_leef {
     my ($self, %options) = @_;
     # $options{dont_quit} = integer
@@ -165,7 +214,7 @@ sub get_leef {
     }
     
     my $results = {};
-    my @array_ref_ar = ();
+    $self->{array_ref_ar} = [];
     my $subset_current = 0;
     my $subset_construct = [];
     foreach my $oid (@{$options{oids}}) {
@@ -177,13 +226,13 @@ sub get_leef {
         push @$subset_construct, [$oid, $instance];
         $subset_current++;
         if ($subset_current == $self->{subsetleef}) {
-            push @array_ref_ar, \@$subset_construct;
+            push @{$self->{array_ref_ar}}, \@$subset_construct;
             $subset_construct = [];
             $subset_current = 0;
         }
     }
     if ($subset_current) {
-        push @array_ref_ar, \@$subset_construct;
+        push @{$self->{array_ref_ar}}, \@$subset_construct;
     }
     
     ############################
@@ -232,20 +281,23 @@ sub get_leef {
     ############################
     
     my $total = 0;
-    foreach (@array_ref_ar) {
-        my $vb = new SNMP::VarList(@{$_});
+    while (my $entry = shift(@{$self->{array_ref_ar}})) {
+        my $vb = new SNMP::VarList(@{$entry});
         $self->{session}->get($vb);
         if ($self->{session}->{ErrorNum}) {
             # 0    noError       Pas d'erreurs.
             # 1    tooBig        Reponse de taille trop grande.
             # 2    noSuchName    Variable inexistante.
+            # -24  Timeout
             if ($self->{session}->{ErrorNum} == 2) {
                 # We are at the end with snmpv1. We next.
                 next;
             }
-        
-            my $msg = 'SNMP GET Request : ' . $self->{session}->{ErrorStr};
-            
+
+            if ($self->{snmp_autoreduce} == 1 && ($self->{session}->{ErrorNum} == 1 || $self->{session}->{ErrorNum} == -24)) {
+                next if ($self->autoreduce_leef(current => $entry) == 0);
+            }
+            my $msg = 'SNMP GET Request : ' . $self->{session}->{ErrorStr};    
             if ($dont_quit == 0) {
                 $self->{output}->add_option_msg(short_msg => $msg);
                 $self->{output}->option_exit(exit_litteral => $self->{snmp_errors_exit});
@@ -503,6 +555,7 @@ sub get_table {
         $last_oid =~ /(.*)\.(\d+)([\.\s]*)$/;
         my $vb = new SNMP::VarList([$1, $2]);
     
+        print "===" . $repeat_count . "===\n";
         if ($self->is_snmpv1() || defined($self->{snmp_force_getnext})) {
             $self->{session}->getnext($vb);
         } else {
@@ -514,10 +567,15 @@ sub get_table {
             # 0    noError       Pas d'erreurs.
             # 1    tooBig        Reponse de taille trop grande.
             # 2    noSuchName    Variable inexistante.
+            # -24  Timeout
             if ($self->{session}->{ErrorNum} == 2) {
                 # We are at the end with snmpv1. We quit.
                 last;
             }
+            if ($self->{snmp_autoreduce} == 1 && ($self->{session}->{ErrorNum} == 1 || $self->{session}->{ErrorNum} == -24)) {
+                next if ($self->autoreduce_table(repeat_count => \$repeat_count) == 0);
+            }
+            
             my $msg = 'SNMP Table Request : ' . $self->{session}->{ErrorStr};
         
             if ($dont_quit == 0) {
@@ -650,15 +708,18 @@ sub check_options {
     $self->{subsetleef} = (defined($options{option_results}->{subsetleef}) && $options{option_results}->{subsetleef} =~ /^[0-9]+$/) ? $options{option_results}->{subsetleef} : 50;
     $self->{subsettable} = (defined($options{option_results}->{subsettable}) && $options{option_results}->{subsettable} =~ /^[0-9]+$/) ? $options{option_results}->{subsettable} : 100;
     $self->{snmp_errors_exit} = $options{option_results}->{snmp_errors_exit};
+    $self->{snmp_autoreduce} = defined($options{option_results}->{snmp_autoreduce}) ? 1 : 0;
 
     %{$self->{snmp_params}} = (DestHost => $options{option_results}->{host},
                                Community => $options{option_results}->{snmp_community},
                                Version => $options{option_results}->{snmp_version},
-                               RemotePort => $options{option_results}->{snmp_port});
+                               RemotePort => $options{option_results}->{snmp_port},
+                               Retries => 5);
     
     if (defined($options{option_results}->{snmp_timeout}) && $options{option_results}->{snmp_timeout} =~ /^[0-9]+$/) {
         $self->{snmp_params}->{Timeout} = $options{option_results}->{snmp_timeout} * (10**6);
     }
+    
     if (defined($options{option_results}->{snmp_retries}) && $options{option_results}->{snmp_retries} =~ /^[0-9]+$/) {
         $self->{snmp_params}->{Retries} = $options{option_results}->{snmp_retries};
     }
@@ -855,6 +916,10 @@ Max repetitions value (default: 50) (only for SNMP v2 and v3).
 
 How many oid values per SNMP request (default: 50) (for get_leef method. Be cautious whe you set it. Prefer to let the default value).
 
+=item B<--snmp-autoreduce>
+ 
+Auto reduce SNMP request size in case of SNMP errors.
+
 =item B<--snmp-force-getnext>
 
 Use snmp getnext function (even in snmp v2c and v3).