GetAllMatchRules: provide an example how it could be used

[use dist_examples_SCRIPTS instead of EXTRA_DIST -smcv]

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=84598
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>

tools/GetAllMatchRules.py

@@ -0,0 +1,112 @@
+#!/usr/bin/env python
+
+import sys
+import argparse
+import dbus
+import time
+
+def get_cmdline(pid):
+  cmdline = ''
+  if pid > 0:
+    try:
+      procpath = '/proc/' + str(pid) + '/cmdline'
+      with open(procpath, 'r') as f:
+        cmdline = " ".join(f.readline().split('\0'))
+    except:
+      pass
+  return cmdline
+
+# Parsing parameters
+
+parser = argparse.ArgumentParser(description='Testing D-Bus match rules')
+parser.add_argument('--session', help='session bus', action="store_true")
+parser.add_argument('--system', help='system bus', action="store_true")
+parser.add_argument('--all', help='print all match rules', action="store_true")
+args = parser.parse_args()
+
+if args.system and args.session:
+  parser.print_help()
+  sys.exit(1)
+
+# Fetch data from the bus driver
+
+if args.system:
+  bus = dbus.SystemBus()
+else:
+  bus = dbus.SessionBus()
+
+remote_object = bus.get_object("org.freedesktop.DBus",
+                               "/org/freedesktop/DBus")
+bus_iface = dbus.Interface(remote_object, "org.freedesktop.DBus")
+stats_iface = dbus.Interface(remote_object, "org.freedesktop.DBus.Debug.Stats")
+
+try:
+  match_rules = stats_iface.GetAllMatchRules()
+except:
+  print("GetConnectionMatchRules failed: did you enable the Stats interface?")
+  sys.exit(1)
+
+names = bus_iface.ListNames()
+unique_names = [ a for a in names if a.startswith(":") ]
+pids = dict((name, bus_iface.GetConnectionUnixProcessID(name)) for name in unique_names)
+cmds = dict((name, get_cmdline(pids[name])) for name in unique_names)
+well_known_names = [ a for a in names if a not in unique_names ]
+owners = dict((wkn, bus_iface.GetNameOwner(wkn)) for wkn in well_known_names)
+
+rules = dict((k_rules,
+              dict({
+                'wkn': [k for k, v in owners.items() if v == k_rules],
+                'pid': pids[k_rules],
+                'cmd': cmds[k_rules] or "",
+                'rules': v_rules,
+                'warnings': dict({
+                  'not_signal': [a for a in v_rules if "type='signal'" not in a],
+                  'no_sender': [a for a in v_rules if "sender=" not in a],
+                  'local': [a for a in v_rules if "org.freedesktop.DBus.Local" in a],
+                  'NameOwnerChanged_arg0': [a for a in v_rules if "member='NameOwnerChanged'" in a and "arg0" not in a]
+                })
+              })
+             ) for k_rules, v_rules in match_rules.items())
+
+warnings = dict({
+             'not_signal': 'Match rule without selecting signals',
+             'no_sender': 'Match rule without a sender criteria',
+             'local': 'Match rule on the org.freedesktop.DBus.Local interface',
+             'NameOwnerChanged_arg0': 'Match rule on NameOwnerChanged without a arg0* criteria'
+           })
+
+# Print the match rules
+
+# print all match rules without analysing them
+if args.all:
+  for name in rules:
+    print("Connection %s with pid %d '%s' (%s): %d match rules, %d warnings"
+          % (name, rules[name]['pid'], rules[name]['cmd'],
+             ' '.join(rules[name]['wkn']), len(rules[name]['rules']),
+             len(sum(rules[name]['warnings'].values(), []))))
+    for rule in rules[name]['rules']:
+      print("\t%s" % (rule))
+    print("")
+  sys.exit(0)
+
+# analyse match rules and print only the suspicious ones
+for conn,data in rules.items():
+  warnings_count = len(sum(data['warnings'].values(), []))
+  if warnings_count == 0:
+    continue
+
+  print("Connection %s with pid %d '%s' (%s): %d match rules, %d warnings"
+        % (conn, data['pid'], data['cmd'], ' '.join(data['wkn']),
+           len(data['rules']), warnings_count))
+
+  for warn_code,rule_list in [(warn_code,rule_list) \
+                              for warn_code, rule_list \
+                              in data['warnings'].items() \
+                              if len(rule_list) > 0]:
+    print("   - %s:" % (warnings[warn_code]))
+    for rule in rule_list:
+      print("         - %s" % (rule))
+
+  print("")
+
+sys.exit(0)

tools/Makefile.am

@@ -76,6 +76,11 @@ dbus_launch_LDADD = \
 	$(DBUS_X_LIBS) \
 	$(NULL)
 
+examplesdir = ${docdir}/examples
+dist_examples_SCRIPTS = \
+	GetAllMatchRules.py \
+	$(NULL)
+
 EXTRA_DIST = run-with-tmp-session-bus.sh strtoll.c strtoull.c
 CLEANFILES = 				\
 	run-with-tmp-session-bus.conf