(plugin) apps::protocols::snmp - add snmp cache system (#4443)

src/apps/protocols/snmp/mode/cache.pm

@@ -0,0 +1,115 @@
+#
+# Copyright 2023 Centreon (http://www.centreon.com/)
+#
+# Centreon is a full-fledged industry-strength solution that meets
+# the needs in IT infrastructure and application monitoring for
+# service performance.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+package apps::protocols::snmp::mode::cache;
+
+use base qw(centreon::plugins::mode);
+
+use strict;
+use warnings;
+use JSON::XS;
+
+sub new {
+    my ($class, %options) = @_;
+    my $self = $class->SUPER::new(package => __PACKAGE__, %options);
+    bless $self, $class;
+
+    $options{options}->add_options(arguments => {
+        'file:s'      => { name => 'file' },
+        'snmpwalk:s@' => { name => 'snmpwalk' },
+        'snmpget:s@'  => { name => 'snmpget' }
+    });
+
+    return $self;
+}
+
+sub check_options {
+    my ($self, %options) = @_;
+    $self->SUPER::init(%options);
+
+    if (!defined($self->{option_results}->{file}) || $self->{option_results}->{file} eq '') {
+        $self->{output}->add_option_msg(short_msg => "Missing parameter --file");
+        $self->{output}->option_exit();
+    }
+}
+
+sub run {
+    my ($self, %options) = @_;
+
+    my $snmp_datas = {};
+    if (defined($self->{option_results}->{snmpwalk})) {
+        foreach my $oid (@{$self->{option_results}->{snmpwalk}}) {
+            my $result = $options{snmp}->get_table(oid => $oid);
+            $snmp_datas = { %$snmp_datas, %$result };
+        }
+    }
+
+    if (defined($self->{option_results}->{snmpget})) {
+        my $result = $options{snmp}->get_leef(oids => $self->{option_results}->{snmpget});
+        $snmp_datas = { %$snmp_datas, %$result };
+    }
+
+    my $json;
+    eval {
+        $json = JSON::XS->new->encode($snmp_datas);
+    };
+
+    my $fh;
+    if (!open($fh, '>', $self->{option_results}->{file})) {
+        $self->{output}->add_option_msg(short_msg => "Can't open file '$self->{option_results}->{file}': $!");
+        $self->{output}->option_exit();
+    }
+    print $fh $json;
+    close($fh);
+
+    $self->{output}->output_add(
+        severity => 'OK',
+        short_msg => 'SNMP cache file created'
+    );
+
+    $self->{output}->display(force_ignore_perfdata => 1);
+    $self->{output}->exit();
+}
+    
+1;
+
+__END__
+
+=head1 MODE
+
+Cache SNMP datas in a JSON cache file.
+
+=over 8
+
+=item B<--file>
+
+JSON cache file path.
+
+=item B<--snmpget>
+
+Retrieve a management value.
+
+=item B<--snmpwalk>
+
+Retrieve a subtree of management values.
+
+=back
+
+=cut

src/apps/protocols/snmp/plugin.pm

@@ -30,6 +30,7 @@ sub new {
     bless $self, $class;
 
     $self->{modes} = {
+        'cache'           => 'apps::protocols::snmp::mode::cache',
         'collection'      => 'apps::protocols::snmp::mode::collection',
         'discovery'       => 'snmp_standard::mode::discovery',
         'dynamic-command' => 'snmp_standard::mode::dynamiccommand',

src/centreon/plugins/snmp.pm

@@ -22,6 +22,7 @@ package centreon::plugins::snmp;
 
 use strict;
 use warnings;
+use centreon::plugins::misc;
 use SNMP;
 use Socket;
 use POSIX;
@@ -54,6 +55,7 @@ sub new {
             'maxrepetitions:s'   => { name => 'maxrepetitions', default => 50 },
             'subsetleef:s'       => { name => 'subsetleef', default => 50 },
             'subsettable:s'      => { name => 'subsettable', default => 100 },
+            'snmp-cache-file:s'  => { name => 'snmp_cache_file' },
             'snmp-autoreduce:s'  => { name => 'snmp_autoreduce' },
             'snmp-force-getnext' => { name => 'snmp_force_getnext' },
             'snmp-username:s'    => { name => 'snmp_security_name' },
@@ -221,6 +223,24 @@ sub autoreduce_leef {
     return 0;
 }
 
+sub get_leef_cache {
+    my ($self, %options) = @_;
+
+    my $results = {};
+    foreach my $oid (@{$options{oids}}) {
+        if (defined($self->{snmp_cache}->{$oid})) {
+            $results->{$oid} = $self->{snmp_cache}->{$oid};
+        }
+    }
+
+    if ($options{nothing_quit} == 1 && scalar(keys %$results) <= 0) {
+        $self->{output}->add_option_msg(short_msg => 'SNMP GET Request: Cant get a single value.');
+        $self->{output}->option_exit(exit_litteral => $self->{snmp_errors_exit});
+    }
+
+    return $results;
+}
+
 sub get_leef {
     my ($self, %options) = @_;
     # $options{dont_quit} = integer
@@ -247,6 +267,10 @@ sub get_leef {
         @{$self->{oids_loaded}} = ();
     }
 
+    if ($self->{use_snmp_cache} == 1) {
+        return $self->get_leef_cache(oids => $options{oids}, nothing_quit => $nothing_quit);
+    }
+
     my $results = {};
     $self->{array_ref_ar} = [];
     my $subset_current = 0;
@@ -396,6 +420,43 @@ sub multiple_find_bigger {
     return $getting->{pop(@values)};
 }
 
+sub get_multiple_table_cache {
+    my ($self, %options) = @_;
+
+    my $results = {};
+    foreach my $entry (@{$options{oids}}) {
+        my $result = $self->get_table_cache(
+            oid => $entry->{oid},
+            start => $entry->{start},
+            end => $entry->{end},
+            nothing_quit => 0
+        );
+        if ($options{return_type} == 0) {
+            $results->{ $entry->{oid} } = $result;
+        } else {
+            $results = { %$results, %$result };
+        }
+    }
+
+    my $total = 0;
+    if ($options{nothing_quit} == 1) {
+        if ($options{return_type} == 1) {
+            $total = scalar(keys %$results);
+        } else {
+            foreach (keys %$results) {
+                $total += scalar(keys %{$results->{$_}});
+            }
+        }
+
+        if ($total == 0) {
+            $self->{output}->add_option_msg(short_msg => 'SNMP Table Request: Cant get a single value.');
+            $self->{output}->option_exit(exit_litteral => $self->{snmp_errors_exit});
+        }
+    }
+
+    return $results;
+}
+
 sub get_multiple_table {
     my ($self, %options) = @_;
     # $options{dont_quit} = integer
@@ -408,6 +469,14 @@ sub get_multiple_table {
     my ($nothing_quit) = (defined($options{nothing_quit}) && $options{nothing_quit} == 1) ? 1 : 0;
     $self->set_error();
 
+    if ($self->{use_snmp_cache} == 1) {
+        return $self->get_multiple_table_cache(
+            oids => $options{oids},
+            return_type => $return_type,
+            nothing_quit => $nothing_quit
+        );
+    }
+
     my $working_oids = {};
     my $results = {};
     # Check overlap
@@ -560,6 +629,29 @@ sub get_multiple_table {
     return $results;
 }
 
+sub get_table_cache {
+    my ($self, %options) = @_;
+
+    my $branch = defined($options{start}) ? $options{start} : $options{oid};
+
+    my $results = {};
+    foreach my $oid ($self->oid_lex_sort(keys %{$self->{snmp_cache}})) {
+        if ($oid =~ /^$branch\./) {
+            $results->{$oid} = $self->{snmp_cache}->{$oid};
+            if (defined($options{end}) && $self->check_oid_up(current => $oid, end => $options{end})) {
+                last;
+            } 
+        }
+    }
+
+    if ($options{nothing_quit} == 1 && scalar(keys %$results) <= 0) {
+        $self->{output}->add_option_msg(short_msg => 'SNMP Table Request: Cant get a single value.');
+        $self->{output}->option_exit(exit_litteral => $self->{snmp_errors_exit});
+    }
+
+    return $results;
+}
+
 sub get_table {
     my ($self, %options) = @_;
     # $options{dont_quit} = integer
@@ -578,6 +670,15 @@ sub get_table {
         $options{end} = $self->clean_oid($options{end});
     }
 
+    if ($self->{use_snmp_cache} == 1) {
+        return $self->get_table_cache(
+            oid => $options{oid},
+            start => $options{start},
+            end => $options{end},
+            nothing_quit => $nothing_quit
+        );
+    }
+
     # we use a medium (UDP have a PDU limit. SNMP protcol cant send multiples for one request)
     # So we need to manage
     # It's for "bulk". We ask 50 next values. If you set 1, it's like a getnext (snmp v1)
@@ -597,7 +698,7 @@ sub get_table {
         $self->{output}->option_exit(exit_litteral => $self->{snmp_errors_exit});
     }
 
-    my $main_indice = $1 . "." . $2;
+    my $main_indice = $1 . '.' . $2;
     my $results = {};
 
     # Quit if base not the same or 'ENDOFMIBVIEW' value
@@ -751,7 +852,28 @@ sub check_oid_up {
 
 sub check_options {
     my ($self, %options) = @_;
-    # $options{option_results} = ref to options result
+
+    $self->{snmp_errors_exit} = $options{option_results}->{snmp_errors_exit};
+
+    $self->{use_snmp_cache} = 0;
+    if (defined($options{option_results}->{snmp_cache_file}) && $options{option_results}->{snmp_cache_file} ne '') {
+        centreon::plugins::misc::mymodule_load(
+            output => $self->{output},
+            module => 'JSON::XS',
+            error_msg => "Cannot load module 'JSON::XS'."
+        );
+        my $content = centreon::plugins::misc::slurp_file(output => $self->{output}, file => $options{option_results}->{snmp_cache_file});
+        eval {
+            $self->{snmp_cache} = JSON::XS->new->decode($content);
+        };
+        if ($@) {
+            $self->{output}->add_option_msg(short_msg => "Cannot decode json cache file: $@");
+            $self->{output}->option_exit();
+        }
+
+        $self->{use_snmp_cache} = 1;
+        return ;
+    }
 
     if (!defined($options{option_results}->{host})) {
         $self->{output}->add_option_msg(short_msg => 'Missing parameter --hostname.');
@@ -768,7 +890,6 @@ sub check_options {
     $self->{maxrepetitions} = $options{option_results}->{maxrepetitions};
     $self->{subsetleef} = (defined($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} = 0;
     $self->{snmp_autoreduce_divisor} = 2;
     if (defined($options{option_results}->{snmp_autoreduce})) {
@@ -1023,6 +1144,10 @@ Auto reduce SNMP request size in case of SNMP errors (By default, the divisor is
 
 Use snmp getnext function (even in snmp v2c and v3).
 
+=item B<--snmp-cache-file>
+
+Use SNMP cache file.
+
 =item B<--snmp-username>
 
 Security name (only for SNMP v3).