s4-python: import a copy of the python dns library

This library is not installed on enough systems for us to rely
on it being available. We use the system copy if possible, and
fallback to this local copy

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/source4/scripting/python/samba_external/dnspython/examples/reverse.py b/source4/scripting/python/samba_external/dnspython/examples/reverse.py
new file mode 100755
index 0000000000..8657baed44
--- /dev/null
+++ b/source4/scripting/python/samba_external/dnspython/examples/reverse.py
@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+
+# Usage: reverse.py <zone_filename>...
+#
+# This demo script will load in all of the zones specified by the
+# filenames on the command line, find all the A RRs in them, and
+# construct a reverse mapping table that maps each IP address used to
+# the list of names mapping to that address.  The table is then sorted
+# nicely and printed.
+#
+# Note!  The zone name is taken from the basename of the filename, so
+# you must use filenames like "/wherever/you/like/dnspython.org" and
+# not something like "/wherever/you/like/foo.db" (unless you're
+# working with the ".db" GTLD, of course :)).
+#
+# If this weren't a demo script, there'd be a way of specifying the
+# origin for each zone instead of constructing it from the filename.
+
+import dns.zone
+import dns.ipv4
+import os.path
+import sys
+
+reverse_map = {}
+
+for filename in sys.argv[1:]:
+    zone = dns.zone.from_file(filename, os.path.basename(filename),
+                              relativize=False)
+    for (name, ttl, rdata) in zone.iterate_rdatas('A'):
+        try:
+	    reverse_map[rdata.address].append(name.to_text())
+	except KeyError:
+	    reverse_map[rdata.address] = [name.to_text()]
+
+keys = reverse_map.keys()
+keys.sort(lambda a1, a2: cmp(dns.ipv4.inet_aton(a1), dns.ipv4.inet_aton(a2)))
+for k in keys:
+    v = reverse_map[k]
+    v.sort()
+    print k, v