Support for snmpforce_v1, snmpforce_v2, snmpforce_v3

Netdisco/lib/App/Netdisco/Manual/Configuration.pod

@@ -388,7 +388,7 @@ of the device. The regex must match the complete value.
 
 =head3 C<bulkwalk_repeaters>
 
-Value: Numnber. Default: 20.
+Value: Number. Default: 20.
 
 Sets the Net-SNMP C<MaxRepeaters> value, which is used on C<BULKWALK>
 operations. See L<SNMP> for more info.
@@ -409,6 +409,24 @@ Value: C<1|2|3>. Default: 3.
 Highest version of the SNMP protocol used when connecting to devices. Use this
 setting to disable SNMP v3 globally. Usually you don't need to configure this.
 
+=head3 C<snmpforce_v1>
+
+Value: List of Network Identifiers or Device Properties. Default: Empty List.
+
+Forces matching devices to use SNMPv1.
+
+=head3 C<snmpforce_v2>
+
+Value: List of Network Identifiers or Device Properties. Default: Empty List.
+
+Forces matching devices to use SNMPv2c.
+
+=head3 C<snmpforce_v3>
+
+Value: List of Network Identifiers or Device Properties. Default: Empty List.
+
+Forces matching devices to use SNMPv3.
+
 =head3 C<snmptimeout>
 
 Value: Number. Default: 1000000.
@@ -874,18 +892,6 @@ C<portctl_timeout>
 
 =item *
 
-C<snmpforce_v1>
-
-=item *
-
-C<snmpforce_v2>
-
-=item *
-
-C<snmpforce_v3>
-
-=item *
-
 C<timeout>
 
 =back

Netdisco/lib/App/Netdisco/Util/Device.pm

@@ -101,7 +101,8 @@ sub check_acl {
 =head2 check_no( $ip, $setting_name )
 
 Given the IP address of a device, returns true if the configuration setting
-C<$setting_name> matches that device, else returns false.
+C<$setting_name> matches that device, else returns false. If the setting
+is undefined or empty, then C<check_no> also returns false.
 
  print "rejected!" if check_no($ip, 'discover_no');
 
@@ -133,15 +134,16 @@ sub check_no {
   my ($ip, $setting_name) = @_;
 
   my $config = setting($setting_name) || [];
-  return 0 unless scalar @$config;
+  return 0 if not scalar @$config;
 
   return check_acl($ip, $config);
 }
 
 =head2 check_only( $ip, $setting_name )
 
-Given the IP address of a device, returns false if the configuration setting
-C<$setting_name> matches that device, else returns true.
+Given the IP address of a device, returns true if the configuration setting
+C<$setting_name> matches that device, else returns false. If the setting
+is undefined or empty, then C<check_only> also returns true.
 
  print "rejected!" unless check_only($ip, 'discover_only');
 
@@ -173,7 +175,7 @@ sub check_only {
   my ($ip, $setting_name) = @_;
 
   my $config = setting($setting_name) || [];
-  return 1 unless scalar @$config;
+  return 1 if not scalar @$config;
 
   return check_acl($ip, $config);
 }

Netdisco/lib/App/Netdisco/Util/SNMP.pm

@@ -96,9 +96,12 @@ sub _snmp_connect_generic {
       $snmp_args{AutoSpecity} = 1;
   }
 
-  # TODO: add version force support
-  # use existing SNMP version or try 3, 2, 1
-  my @versions = reverse (1 .. (setting('snmpver') || 3));
+  # which SNMP versions to try and in what order
+  my @versions =
+    ( check_no($device->ip, 'snmpforce_v3') ? (3)
+    : check_no($device->ip, 'snmpforce_v2') ? (2)
+    : check_no($device->ip, 'snmpforce_v1') ? (1)
+    : (reverse (1 .. (setting('snmpver') || 3))) );
 
   # get the community string(s)
   my @communities = _build_communities($device, $mode);