From e1b0399ee018d217cd50267cef03c28dfdb32fbf Mon Sep 17 00:00:00 2001
From: Arthur de Jong <arthur@arthurdejong.org>
Date: Fri, 26 Jul 2013 14:59:43 +0200
Subject: Rename nscd_invalidate option to reconnect_invalidate

This also renames the internal nscd module to invalidator for both nslcd
and pynslcd. The new invalidator module is now no longer nscd-specific.
---
 pynslcd/invalidator.py | 112 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 pynslcd/invalidator.py

(limited to 'pynslcd/invalidator.py')

diff --git a/pynslcd/invalidator.py b/pynslcd/invalidator.py
new file mode 100644
index 0000000..98c0783
--- /dev/null
+++ b/pynslcd/invalidator.py
@@ -0,0 +1,112 @@
+
+# invalidator.py - functions for invalidating external caches
+#
+# Copyright (C) 2013 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+import fcntl
+import logging
+import os
+import subprocess
+
+import cfg
+
+
+# the file descriptor used for sending messages to the child process
+signalfd = None
+
+
+# mapping between map name and signal character
+_db_to_char = dict(
+        aliases='A', ethers='E', group='G', hosts='H', netgroup='U',
+        networks='N', passwd='P', protocols='L', rpc='R', services='V',
+        shadow='S', nfsidmap='F',
+    )
+_char_to_db = dict((reversed(item) for item in _db_to_char.items()))
+
+
+def exec_invalidate(*args):
+    cmd = ' '.join(args)
+    logging.debug('invalidator: %s', cmd)
+    try:
+        p = subprocess.Popen(args, bufsize=4096, close_fds=True,
+                             stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+        output, ignored = p.communicate()
+        if output:
+            output = ': %s' % output[:1024].strip()
+        if p.returncode == 0:
+            logging.debug('invalidator: %s (pid %d) success%s',
+                          cmd, p.pid, output)
+        elif p.returncode > 0:
+            logging.debug('invalidator: %s (pid %d) failed (%d)%s',
+                          cmd, p.pid, p.returncode, output)
+        else:  # p.returncode < 0
+            logging.error('invalidator: %s (pid %d) killed by signal %d%s',
+                          cmd, p.pid, -p.returncode, output)
+    except:
+        logging.warn('invalidator: %s failed', cmd, exc_info=True)
+
+
+def loop(fd):
+    # set process title
+    try:
+        import setproctitle
+        setproctitle.setproctitle('(invalidator)')
+    except ImportError:
+        pass
+    # set up clean environment
+    os.chdir('/')
+    os.environ['PATH'] = '/usr/sbin:/usr/bin:/sbin:/bin'
+    while True:
+        db = os.read(fd, 1)
+        if db == '':
+            break  # close process down
+        db = _char_to_db.get(db, None)
+        if db == 'nfsidmap':
+            exec_invalidate('nfsidmap', '-c')
+        else if db:
+            exec_invalidate('nscd', '-i', db)
+
+
+def start_invalidator():
+    r, w = os.pipe()
+    # mark write end as non-blocking
+    flags = fcntl.fcntl(w, fcntl.F_GETFL)
+    fcntl.fcntl(w, fcntl.F_SETFL, flags | os.O_NONBLOCK)
+    cpid = os.fork()
+    if cpid == 0:
+        # we are the child
+        os.close(w)
+        loop(r)
+        os._exit(1)
+    # we are the parent
+    global signalfd
+    signalfd = w
+    os.close(r)
+
+
+def invalidate(db=None):
+    if signalfd is None:
+        return  # nothing to do
+    if db:
+        db = _db_to_char.get(db, '')
+    else:
+        db = ''.join(_db_to_char[x] for x in cfg.reconnect_invalidate)
+    try:
+        os.write(signalfd, db)
+    except:
+        logging.warn('requesting invalidation (%s) failed', db, exc_info=True)
-- 
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