storyboard: Add capturing of traffic

This adds the functionality to capture traffic on certain interfaces
so that it can be inspected with tools like wireshark. A user needs to
pass a start and end time and a node and DIF. Rumba will then
determine the correct interface to capture on.

Implements #41

1 files changed, 34 insertions, 0 deletions

diff --git a/rumba/storyboard.py b/rumba/storyboard.py
index ea0c51e..61dd8cc 100644
--- a/rumba/storyboard.py
+++ b/rumba/storyboard.py
@@ -34,6 +34,7 @@ import math
 import os
 import random
 import time
+import uuid
 
 import rumba.model as model
 import rumba.ssh_support as ssh_support
@@ -821,6 +822,39 @@ class StoryBoard(SBEntity):
         buffer = StringIO(string)
         self.parse_script(buffer, clean)
 
+    def capture_traffic(self, start, end, node, dif):
+        """
+        Captures the traffic of an interface on a certain node.
+
+        :param start: The time to start capturing.
+        :param end: The time to stop capturing.
+        :param node: The node to capture on.
+        :param dif: The Shim Ethernet DIF of the node, Rumba
+                    automatically resolves the correct interface.
+        """
+        for ipcp in dif.ipcps:
+            if ipcp.node is not node:
+                continue
+            # In case tcpdump is not present, this assumes a testbed
+            # with Ubuntu/Debian just like the rest of installation
+            if not node.has_tcpdump:
+                ssh_support.aptitude_install(self.experiment.testbed,
+                                             node, ["tcpdump"])
+                node.has_tcpdump = True
+
+            # Create random string
+            pcap_file = node.name + '_' + dif.name + '_' + \
+                        str(uuid.uuid4())[0:4] + ".pcap"
+
+            tcpd_client = Client(ap="tcpdump", options="-i %s -w %s" \
+                                 % (ipcp.ifname, pcap_file))
+            duration = end - start
+            cb = functools.partial(node.fetch_file, pcap_file,
+                                   self.experiment.log_dir, sudo=True)
+            action = functools.partial(self.run_client, tcpd_client,
+                                       duration=duration, node=node,
+                                       callback = cb)
+            self._script.add_event(Event(action, ev_time=start))
 
 class Event(object):