mss: Adds a TCP MSS plugin

pathspider/plugins/mss.py

@@ -0,0 +1,41 @@
+import pathspider
+from pathspider.base import PluggableSpider
+from pathspider.single import SingleSpider
+from pathspider.helpers.http import connect_http
+from pathspider.helpers.http import connect_https
+from pathspider.helpers.tcp import connect_tcp
+from pathspider.chains.basic import BasicChain
+from pathspider.chains.mss import MSSChain
+from pathspider.chains.tcp import TCPChain
+
+class MSS(SingleSpider, PluggableSpider):
+
+    name = "mss"
+    description = "TCP Maximum Segment Size"
+    version = pathspider.base.__version__
+    chains = [BasicChain, TCPChain, MSSChain]
+    connect_supported = ["tcp", "http", "https", "dnstcp"]
+
+    def combine_flows(self, flows):
+        conditions = []
+
+        if not flows[0]['observed']:
+            return ['pathspider.not_observed']
+
+        if flows[0]['tcp_connected']:
+            conditions.append('mss.connectivity.online')
+            conditions.append('mss.option.local.value:' + str(flows[0]['mss_value_fwd']))
+            if flows[0]['mss_len_rev'] is not None:
+                conditions.append('mss.option.received.value:' + str(flows[0]['mss_value_rev']))
+                if (flows[0]['mss_value_rev'] < flows[0]['mss_value_fwd']):
+                    conditions.append('mss.option.received.deflated')
+                elif (flows[0]['mss_value_rev'] == flows[0]['mss_value_fwd']):
+                    conditions.append('mss.option.received.unchanged')
+                else:
+                    conditions.append('mss.option.received.inflated')
+            else:
+                conditions.append('mss.option.received.absent')
+        else:
+            conditions.append('mss.connectivity.offline')
+
+        return conditions