initial import

Original author: Bob Halley <halley@dnspython.org>
Date: 2004-03-23 21:57:40

1 files changed, 121 insertions, 0 deletions

diff --git a/dns/rcode.py b/dns/rcode.py
new file mode 100644
index 0000000..62c1cad
--- /dev/null
+++ b/dns/rcode.py
@@ -0,0 +1,121 @@
+# Copyright (C) 2001-2004 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# $Id: rcode.py,v 1.11 2004/03/19 00:17:27 halley Exp $
+
+"""DNS Result Codes."""
+
+import dns.exception
+
+NOERROR = 0
+FORMERR = 1
+SERVFAIL = 2
+NXDOMAIN = 3
+NOTIMP = 4
+REFUSED = 5
+YXDOMAIN = 6
+YXRRSET = 7
+NXRRSET = 8
+NOTAUTH = 9
+NOTZONE = 10
+BADVERS = 16
+
+_by_text = {
+    'NOERROR' : NOERROR,
+    'FORMERR' : FORMERR,
+    'SERVFAIL' : SERVFAIL,
+    'NXDOMAIN' : NXDOMAIN,
+    'NOTIMP' : NOTIMP,
+    'REFUSED' : REFUSED,
+    'YXDOMAIN' : YXDOMAIN,
+    'YXRRSET' : YXRRSET,
+    'NXRRSET' : NXRRSET,
+    'NOTAUTH' : NOTAUTH,
+    'NOTZONE' : NOTZONE,
+    'BADVERS' : BADVERS
+}
+
+# We construct the inverse mapping programmatically to ensure that we
+# cannot make any mistakes (e.g. omissions, cut-and-paste errors) that
+# would cause the mapping not to be a true inverse.
+
+_by_value = dict([(y, x) for x, y in _by_text.iteritems()])
+
+
+class UnknownRcode(dns.exception.DNSException):
+    """Raised if an rcode is unknown."""
+    pass
+
+def from_text(text):
+    """Convert text into an rcode.
+    
+    @param text: the texual rcode
+    @type text: string
+    @raises UnknownRcode: the rcode is unknown
+    @rtype: int
+    """
+
+    if text.isdigit():
+        v = int(text)
+        if v >= 0 and v <= 4095:
+            return v
+    v = _by_text.get(text.upper())
+    if v is None:
+        raise UnknownRcode
+    return v
+
+def from_flags(flags, ednsflags):
+    """Return the rcode value encoded by flags and ednsflags.
+
+    @param flags: the DNS flags
+    @type flags: int
+    @param ednsflags: the EDNS flags
+    @type ednsflags: int
+    @raises ValueError: rcode is < 0 or > 4095
+    @rtype: int
+    """
+
+    value = (flags & 0x000f) | ((ednsflags >> 20) & 0xff0)
+    if value < 0 or value > 4095:
+        raise ValueError, 'rcode must be >= 0 and <= 4095'
+    return value
+
+def to_flags(value):
+    """Return a (flags, ednsflags) tuple which encodes the rcode.
+
+    @param value: the rcode
+    @type value: int
+    @raises ValueError: rcode is < 0 or > 4095
+    @rtype: (int, int) tuple
+    """
+
+    if value < 0 or value > 4095:
+        raise ValueError, 'rcode must be >= 0 and <= 4095'
+    v = value & 0xf
+    ev = long(value & 0xff0) << 20
+    return (v, ev)
+
+def to_text(value):
+    """Convert rcode into text.
+
+    @param value: the rcode
+    @type value: int
+    @rtype: string
+    """
+    
+    text = _by_value.get(value)
+    if text is None:
+        text = str(value)
+    return text