Support performing captures without filtering.

These are useful when calibrating Wavedroplet, and when determining how
much airtime was used by test transmissions.

Change-Id: Id76f92b7567145a2e77f1d30ddb8de678c6c309d
diff --git a/wifitables/ b/wifitables/
index 2e2f550..83b4e7c 100755
--- a/wifitables/
+++ b/wifitables/
@@ -29,6 +29,7 @@
 j,journal=      append to journal tracking a series of test runs
 i,interface=    wireless interface to use for outgoing connections
 m,monitor=      wireless monitor interface to use
+no-filter       don't attempt to filter packets seen on monitor interface
 r,remote=       remote host to run tests on
 t,time=         length of time in seconds to run isostream test for [50]
@@ -142,7 +143,8 @@
     addr = addr[:mask]
   if opt.monitor:
-    tcpdump_proc, tcpdump_stderr = tcpdump.tcpdump(bssid, opt.monitor, dest_dir)
+    tcpdump_proc, tcpdump_stderr = tcpdump.tcpdump(bssid, opt.monitor, dest_dir,
+                                                   opt.filter)
     print 'Gathering tcpdump in background as',
   if opt.bind and not addr: