class SNMP::MIB
Constants
- MODULE_EXT
Public Class Methods
Import an SMIv2 MIB file for later loading. A module only needs to be installed once.
module_file - the filename of the module to be imported mib_dir - the output directory for the serialized MIB data
NOTE: This implementation requires that the 'smidump' tool is available in the PATH. This tool can be obtained from the libsmi website at http://www.ibr.cs.tu-bs.de/projects/libsmi/ .
ALSO NOTE: The file format in future releases is subject to change. For now, it is a simple YAML hash with the MIB symbol as the key and the OID as the value. These files could be generated manually if 'smidump' is not available.
Here is an example of the contents of an output file:
--- ipDefaultTTL: 1.3.6.1.2.1.4.2 ipForwDatagrams: 1.3.6.1.2.1.4.6 ipOutRequests: 1.3.6.1.2.1.4.10 ipOutNoRoutes: 1.3.6.1.2.1.4.12 ipReasmTimeout: 1.3.6.1.2.1.4.13 icmpInDestUnreachs: 1.3.6.1.2.1.5.3
# File lib/snmp/mib.rb, line 59 def import_module(module_file, mib_dir=DEFAULT_MIB_PATH) raise "smidump tool must be installed" unless import_supported? FileUtils.makedirs mib_dir mib_hash = %x`smidump -k -f python #{module_file}` mib = eval_mib_data(mib_hash) if mib module_name = mib["moduleName"] raise "#{module_file}: invalid file format; no module name" unless module_name if mib["nodes"] oid_hash = {} mib["nodes"].each { |key, value| oid_hash[key] = value["oid"] } if mib["notifications"] mib["notifications"].each { |key, value| oid_hash[key] = value["oid"] } end File.open(module_file_name(module_name, mib_dir), 'w') do |file| YAML.dump(oid_hash, file) file.puts end module_name else warn "*** No nodes defined in: #{module_file} ***" nil end else warn "*** Import failed for: #{module_file} ***" nil end end
The ::import_module method is only supported if the external 'smidump' tool is available. This method returns true if a known version of the tool is available.
# File lib/snmp/mib.rb, line 101 def import_supported? %x`smidump --version` =~ /^smidump 0.4/ && $? == 0 end
Returns a list of MIB modules that have been imported. All of the current IETF MIBs should be available from the default MIB directory.
If a regex is provided, then the module names are matched against that pattern.
# File lib/snmp/mib.rb, line 113 def list_imported(regex=//, mib_dir=DEFAULT_MIB_PATH) list = [] Dir["#{mib_dir}/*.#{MODULE_EXT}"].each do |name| module_name = File.basename(name, ".*") list << module_name if module_name =~ regex end list end
Returns the full filename of the imported MIB file for the given module name.
# File lib/snmp/mib.rb, line 92 def module_file_name(module_name, mib_dir=DEFAULT_MIB_PATH) File.join(mib_dir, module_name + "." + MODULE_EXT) end
# File lib/snmp/mib.rb, line 136 def initialize @by_name = {} @by_module_by_name = {} @by_oid = {} end
Private Class Methods
# File lib/snmp/mib.rb, line 124 def eval_mib_data(mib_hash) ruby_hash = mib_hash. gsub(':', '=>'). # fix hash syntax gsub('(', '[').gsub(')', ']'). # fix tuple syntax sub('FILENAME =', 'filename ='). # get rid of constants sub('MIB =', 'mib =') mib = nil eval(ruby_hash) mib end
Public Instance Methods
Loads a module into this MIB. The module must be imported before it can be loaded. See ::import_module .
# File lib/snmp/mib.rb, line 146 def load_module(module_name, mib_dir=DEFAULT_MIB_PATH) oid_hash = nil File.open(MIB.module_file_name(module_name, mib_dir)) do |file| oid_hash = YAML.load(file.read) end @by_name.merge!(oid_hash) do |key, old, value| warn "warning: overwriting old MIB name '#{key}'" end @by_module_by_name[module_name] = {} @by_module_by_name[module_name].merge!(oid_hash) name_hash = Hash[ oid_hash.invert.to_a.collect { |oid, name| [oid, "#{module_name}::#{name}"] } ] @by_oid.merge!(name_hash) end
Returns the symbolic name of the given OID.
e.g. OID “1.3.6.1.2.1.1.0” returns symbol “SNMPv2-MIB::system.0”
# File lib/snmp/mib.rb, line 246 def name(oid) current_oid = ObjectId.new(oid) index = [] while current_oid.size > 1 name = @by_oid[current_oid.to_s] if name return index.empty? ? name : "#{name}.#{index.join('.')}" end index.unshift current_oid.slice!(-1) end ObjectId.new(oid).to_s end
Returns an ObjectId for the given name. Names are in the format <ModuleName>::<NodeName>.<Index> with ModuleName and Index being optional.
# File lib/snmp/mib.rb, line 223 def oid(name) module_parts = name.to_str.split("::") if module_parts.length == 1 parse_oid(@by_name, name.to_str) elsif module_parts.length == 2 module_name = module_parts[0] oid = module_parts[1] module_hash = @by_module_by_name[module_name] if module_hash parse_oid(module_hash, oid) else raise ModuleNotLoadedError, "module '#{module_name}' not loaded" end else raise ArgumentError, "invalid format: #{name.to_str}" end end
Returns a VarBind object for the given name and value. The name can be a String, ObjectId, or anything that responds to :to_varbind.
String names are in the format <ModuleName>::<NodeName>.<Index> with ModuleName and Index being optional.
# File lib/snmp/mib.rb, line 208 def varbind(name, value=Null) if name.respond_to? :to_str vb = VarBind.new(oid(name), value) else vb = name.to_varbind vb.value = value end vb end
Returns a VarBindList for the provided list of objects. If a string is provided it is interpretted as a symbolic OID.
This method accepts many different kinds of objects:
-
single string object IDs e.g. “1.3.6.1” or “IF-MIB::ifTable.1.1”
-
single ObjectId
-
list of string object IDs
-
list of ObjectIds
-
list of VarBinds
# File lib/snmp/mib.rb, line 172 def varbind_list(object_list, option=:KeepValue) vb_list = VarBindList.new if object_list.respond_to? :to_str vb_list << oid(object_list).to_varbind elsif object_list.respond_to? :to_varbind vb_list << apply_option(object_list.to_varbind, option) else object_list.each do |item| if item.respond_to? :to_str varbind = oid(item).to_varbind else varbind = item.to_varbind end vb_list << apply_option(varbind, option) end end vb_list end
Private Instance Methods
# File lib/snmp/mib.rb, line 191 def apply_option(varbind, option) if option == :NullValue varbind.value = Null elsif option != :KeepValue raise ArgumentError, "invalid option: #{option.to_s}", caller end varbind end
# File lib/snmp/mib.rb, line 259 def parse_oid(node_hash, name) oid_parts = name.split(".") first_part = oid_parts.shift oid_string = node_hash[first_part] if oid_string oid_array = oid_string.split(".") else oid_array = [first_part] end oid_array.concat(oid_parts) ObjectId.new(oid_array) end