support tcp transport protocol

add host info in exception

Author: colinsurprenant

lib/logstash/inputs/snmp.rb

@@ -74,18 +74,23 @@ def register
       retries = host["retries"] || 2
       timeout = host["timeout"] || 1000
 
+      # TODO: move these validations in a custom validator so it happens before the register method is called.
       host_details = host_name.match(HOST_REGEX)
       raise(LogStash::ConfigurationError, "invalid format for host option '#{host_name}'") unless host_details
-      raise(LogStash::ConfigurationError, "only the udp protocol is supported for now") unless host_details[:host_protocol].to_s =~ /udp/i
+      raise(LogStash::ConfigurationError, "only udp & tcp protocols are supported for host option '#{host_name}'") unless host_details[:host_protocol].to_s =~ /^(?:udp|tcp)$/i
+
+      protocol = host_details[:host_protocol]
+      address = host_details[:host_address]
+      port = host_details[:host_port]
 
       definition = {
-        :client => LogStash::SnmpClient.new(host_name, community, version, retries, timeout, mib),
+        :client => LogStash::SnmpClient.new(protocol, address, port, community, version, retries, timeout, mib),
         :get => Array(get),
         :walk => Array(walk),
 
-        :host_protocol => host_details[:host_protocol],
-        :host_address => host_details[:host_address],
-        :host_port => host_details[:host_port],
+        :host_protocol => protocol,
+        :host_address => address,
+        :host_port => port,
         :host_community => community,
       }
       @client_definitions << definition

lib/logstash/inputs/snmp/client.rb

@@ -14,6 +14,7 @@
 java_import "org.snmp4j.smi.OctetString"
 java_import "org.snmp4j.smi.VariableBinding"
 java_import "org.snmp4j.transport.DefaultUdpTransportMapping"
+java_import "org.snmp4j.transport.DefaultTcpTransportMapping"
 java_import "org.snmp4j.util.TreeUtils"
 java_import "org.snmp4j.util.DefaultPDUFactory"
 java_import "org.snmp4j.asn1.BER"
@@ -24,12 +25,19 @@ class SnmpClientError < StandardError
 
   class SnmpClient
 
-    def initialize(address, community, version, retries, timeout, mib)
-      @target = build_target(address, community, version, retries, timeout)
+    def initialize(protocol, address, port, community, version, retries, timeout, mib)
+      transport = case protocol.to_s
+        when "udp"
+          DefaultUdpTransportMapping.new
+        when "tcp"
+          DefaultTcpTransportMapping.new
+        else
+          raise(SnmpClientError, "invalid transport protocol specified '#{protocol.to_s}', expecting 'udp' or 'tcp'")
+        end
+
+      @target = build_target("#{protocol}:#{address}/#{port}", community, version, retries, timeout)
       @mib = mib
 
-      # for now hardwired udp transport
-      transport = DefaultUdpTransportMapping.new
       @snmp = Snmp.new(transport)
       transport.listen()
     end

spec/inputs/snmp_spec.rb

@@ -54,13 +54,15 @@
           {"get" => ["1.0"], "hosts" => [{"host" => "udp:localhost/161"}]},
           {"get" => ["1.0"], "hosts" => [{"host" => "udp:127.0.0.1/112345"}]},
           {"get" => ["1.0"], "hosts" => [{"host" => "udp:127.0.0.1/161", "community" => "public"}]},
+          {"get" => ["1.0"], "hosts" => [{"host" => "tcp:127.0.0.1/112345"}]},
+          {"get" => ["1.0"], "hosts" => [{"host" => "tcp:127.0.0.1/161", "community" => "public"}]},
       ]
     }
 
     let(:invalid_configs) {
       [
           {"get" => ["1.0"], "hosts" => [{"host" => "aaa:127.0.0.1/161"}]},
-          {"get" => ["1.0"], "hosts" => [{"host" => "tcp:127.0.0.1/161"}]},
+          {"get" => ["1.0"], "hosts" => [{"host" => "tcp.127.0.0.1/161"}]},
           {"get" => ["1.0"], "hosts" => [{"host" => "localhost"}]},
           {"get" => ["1.0"], "hosts" => [{"host" => "localhost/161"}]},
           {"get" => ["1.0"], "hosts" => [{"host" => "udp:127.0.0.1"}]},

test/sample.conf

@@ -2,7 +2,7 @@ input {
   snmp {
     get => ["1.3.6.1.2.1.1.1.0", "1.3.6.1.2.1.1.3.0", "1.3.6.1.2.1.1.5.0"]
     mib_paths => ["/Users/colin/dev/src/elasticsearch/logstash-plugins/logstash-input-snmp/test/RFC1213-MIB.dic"]
-    hosts => [{host => "udp:127.0.0.1/161" community => "public"}]
+    hosts => [{host => "tcp:127.0.0.1/1161" community => "public"}]
   }
   snmp {
     walk => ["1.3.6.1.2.1.1"]

test/test_client.rb

@@ -7,7 +7,8 @@
 
 mib = LogStash::SnmpMib.new
 mib.add_mib_path(File.expand_path(File.join("..", "..", "spec", "fixtures", "RFC1213-MIB.dic"), __FILE__))
-client = LogStash::SnmpClient.new("udp:127.0.0.1/161", "public", "2c", 2, 1000, mib)
+#client = LogStash::SnmpClient.new("tcp", "127.0.0.1", "1161", "public", "2c", 2, 1000, mib)
+client = LogStash::SnmpClient.new("udp", "127.0.0.1", "161", "public", "2c", 2, 1000, mib)
 
 pp client.get("1.3.6.1.2.1.1.1.0")