Class: SNMP::MIB

Inherits:
Object
  • Object
show all
Defined in:
lib/snmp/mib.rb

Defined Under Namespace

Classes: ModuleNotLoadedError

Constant Summary collapse

DEFAULT_MIB_PATH = 
nil
MODULE_EXT =

:startdoc:

'yaml'

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ MIB

class methods



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# File 'lib/snmp/mib.rb', line 146

def initialize
    @by_name = {}
    @by_module_by_name = {}
end

Class Method Details

.import_module(module_file, mib_dir = DEFAULT_MIB_PATH) ⇒ Object

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



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# File 'lib/snmp/mib.rb', line 69

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 = `smidump -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

.import_supported? ⇒ Boolean

The MIB.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.

Returns:

  • (Boolean) 


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# File 'lib/snmp/mib.rb', line 111

def import_supported?
    `smidump --version` =~ /^smidump 0.4/  && $? == 0 
end

.list_imported(regex = //, mib_dir = DEFAULT_MIB_PATH) ⇒ Object

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.



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# File 'lib/snmp/mib.rb', line 123

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

.module_file_name(module_name, mib_dir = DEFAULT_MIB_PATH) ⇒ Object

Returns the full filename of the imported MIB file for the given module name.



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# File 'lib/snmp/mib.rb', line 102

def module_file_name(module_name, mib_dir=DEFAULT_MIB_PATH)
    File.join(mib_dir, module_name + "." + MODULE_EXT)
end

Instance Method Details

#load_module(module_name, mib_dir = DEFAULT_MIB_PATH) ⇒ Object

Loads a module into this MIB. The module must be imported before it can be loaded. See MIB.import_module .



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# File 'lib/snmp/mib.rb', line 155

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)
end

#oid(name) ⇒ Object

Returns an ObjectId for the given name. Names are in the format <ModuleName>::<NodeName>.<Index> with ModuleName and Index being optional.



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# File 'lib/snmp/mib.rb', line 229

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

#varbind(name, value = Null) ⇒ Object

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.



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# File 'lib/snmp/mib.rb', line 214

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

#varbind_list(object_list, option = :KeepValue) ⇒ Object

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



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# File 'lib/snmp/mib.rb', line 178

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