Move dnsclient into ipa-python so that I will be able to use it in ipaconfig

1 files changed, 445 insertions, 0 deletions

diff --git a/ipa-python/dnsclient.py b/ipa-python/dnsclient.py
new file mode 100644
index 000000000..bc8a229cd
--- /dev/null
+++ b/ipa-python/dnsclient.py
@@ -0,0 +1,445 @@
+#
+# Copyright 2001, 2005 Red Hat, Inc.
+#
+# This is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program 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
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+#
+
+import struct
+import socket
+import sys
+
+import acutil
+
+DNS_C_IN = 1
+DNS_C_CS = 2
+DNS_C_CHAOS = 3
+DNS_C_HS = 4
+DNS_C_ANY = 255
+
+DNS_T_A = 1
+DNS_T_NS = 2
+DNS_T_CNAME = 5
+DNS_T_SOA = 6
+DNS_T_NULL = 10
+DNS_T_WKS = 11
+DNS_T_PTR = 12
+DNS_T_HINFO = 13
+DNS_T_MX = 15
+DNS_T_TXT = 16
+DNS_T_SRV = 33
+DNS_T_ANY = 255
+
+DEBUG_DNSCLIENT = False
+
+class DNSQueryHeader:
+	FORMAT = "!HBBHHHH"
+	def __init__(self):
+		self.dns_id = 0
+		self.dns_rd = 0
+		self.dns_tc = 0
+		self.dns_aa = 0
+		self.dns_opcode = 0
+		self.dns_qr = 0
+		self.dns_rcode = 0
+		self.dns_z = 0
+		self.dns_ra = 0
+		self.dns_qdcount = 0
+		self.dns_ancount = 0
+		self.dns_nscount = 0
+		self.dns_arcount = 0
+
+	def pack(self):
+		return struct.pack(DNSQueryHeader.FORMAT,
+			self.dns_id,
+			(self.dns_rd & 1) |
+			(self.dns_tc & 1) << 1 |
+			(self.dns_aa & 1) << 2 |
+			(self.dns_opcode & 15) << 3 |
+			(self.dns_qr & 1) << 7,
+			(self.dns_rcode & 15) |
+			(self.dns_z & 7) << 4 |
+			(self.dns_ra & 1) << 7,
+			self.dns_qdcount,
+			self.dns_ancount,
+			self.dns_nscount,
+			self.dns_arcount)
+
+	def unpack(self, data):
+		(self.dns_id, byte1, byte2, self.dns_qdcount, self.dns_ancount,
+			self.dns_nscount, self.dns_arcount) = struct.unpack(DNSQueryHeader.FORMAT, data[0:self.size()])
+		self.dns_rd = byte1 & 1
+		self.dns_tc = (byte1 >> 1) & 1
+		self.dns_aa = (byte1 >> 2) & 1
+		self.dns_opcode = (byte1 >> 3) & 15
+		self.dns_qr = (byte1 >> 7) & 1
+		self.dns_rcode = byte2 & 15
+		self.dns_z = (byte2 >> 4) & 7
+		self.dns_ra = (byte1 >> 7) & 1
+	
+	def size(self):
+		return struct.calcsize(DNSQueryHeader.FORMAT)
+
+def unpackQueryHeader(data):
+	header = DNSQueryHeader()
+	header.unpack(data)
+	return header
+
+class DNSResult:
+	FORMAT = "!HHIH"
+	QFORMAT = "!HH"
+	def __init__(self):
+		self.dns_name = ""
+		self.dns_type = 0
+		self.dns_class = 0
+		self.dns_ttl = 0
+		self.dns_rlength = 0
+		self.rdata = None
+
+	def unpack(self, data):
+		(self.dns_type, self.dns_class, self.dns_ttl,
+			self.dns_rlength) = struct.unpack(DNSResult.FORMAT, data[0:self.size()])
+			
+	def qunpack(self, data):
+		(self.dns_type, self.dns_class) = struct.unpack(DNSResult.QFORMAT, data[0:self.qsize()])
+
+	def size(self):
+		return struct.calcsize(DNSResult.FORMAT)
+
+	def qsize(self):
+		return struct.calcsize(DNSResult.QFORMAT)
+
+class DNSRData:
+	def __init__(self):
+		pass	
+
+#typedef struct dns_rr_a {
+#	u_int32_t address;
+#} dns_rr_a_t;
+#
+#typedef struct dns_rr_cname {
+#	const char *cname;
+#} dns_rr_cname_t;
+#
+#typedef struct dns_rr_hinfo {
+#	const char *cpu, *os;
+#} dns_rr_hinfo_t;
+#
+#typedef struct dns_rr_mx {
+#	u_int16_t preference;
+#	const char *exchange;
+#} dns_rr_mx_t;
+#
+#typedef struct dns_rr_null {
+#	unsigned const char *data;
+#} dns_rr_null_t;
+#
+#typedef struct dns_rr_ns {
+#	const char *nsdname;
+#} dns_rr_ns_t;
+#
+#typedef struct dns_rr_ptr {
+#	const char *ptrdname;
+#} dns_rr_ptr_t;
+#
+#typedef struct dns_rr_soa {
+#	const char *mname;
+#	const char *rname;
+#	u_int32_t serial;
+#	int32_t refresh;
+#	int32_t retry;
+#	int32_t expire;
+#	int32_t minimum;
+#} dns_rr_soa_t;
+#
+#typedef struct dns_rr_txt {
+#	const char *data;
+#} dns_rr_txt_t;
+#
+#typedef struct dns_rr_srv {
+#	const char *server;
+#	u_int16_t priority;
+#	u_int16_t weight;
+#	u_int16_t port;
+#} dns_rr_srv_t;
+
+def dnsNameToLabel(name):
+	out = ""
+	name = name.split(".")
+	for part in name:
+		out += chr(len(part)) + part
+	return out
+
+def dnsFormatQuery(query, qclass, qtype):
+	header = DNSQueryHeader()
+
+	header.dns_id = 0 # FIXME: id = 0
+	header.dns_rd = 1 # don't know why the original code didn't request recursion for non SOA requests
+	header.dns_qr = 0 # query
+	header.dns_opcode = 0 # standard query
+	header.dns_qdcount = 1 # single query
+
+	qlabel = dnsNameToLabel(query)
+	if not qlabel:
+		return ""
+
+	out = header.pack() + qlabel
+	out += chr(qtype >> 8)
+	out += chr(qtype & 0xff)
+	out += chr(qclass >> 8)
+	out += chr(qclass & 0xff)
+
+	return out
+
+def dnsParseLabel(label, base):
+	# returns (output, rest)
+	if not label:
+		return ("", None)
+
+	update = 1
+	rest = label
+	output = ""
+	skip = 0
+	
+	try:
+		while ord(rest[0]):
+			if ord(rest[0]) & 0xc0:
+				rest = base[((ord(rest[0]) & 0x3f) << 8) + ord(rest[1]):]
+				if update:
+					skip += 2
+				update = 0
+				continue
+			output += rest[1:ord(rest[0]) + 1] + "."
+			if update:
+				skip += ord(rest[0]) + 1
+			rest = rest[ord(rest[0]) + 1:]
+	except IndexError:
+		return ("", None)
+	return (label[skip+update:], output)
+
+def dnsParseA(data, base):
+	rdata = DNSRData()
+	if len(data) < 4:
+		rdata.address = 0
+		return None
+		
+	rdata.address = (ord(data[0])<<24) | (ord(data[1])<<16) | (ord(data[2])<<8) | (ord(data[3])<<0)
+		
+	if DEBUG_DNSCLIENT:
+		print "A = %d.%d.%d.%d." % (ord(data[0]), ord(data[1]), ord(data[2]), ord(data[3]))
+	return rdata
+
+def dnsParseText(data):	
+	if len(data) < 1:
+		return ("", None)
+	tlen = ord(data[0])
+	if len(data) < tlen + 1:
+		return ("", None)
+	return (data[tlen+1:], data[1:tlen+1])
+
+def dnsParseNS(data, base):
+	rdata = DNSRData()
+	(rest, rdata.nsdname) = dnsParseLabel(data, base)
+	if DEBUG_DNSCLIENT:
+		print "NS DNAME = \"%s\"." % (rdata.nsdname)
+	return rdata
+
+def dnsParseCNAME(data, base):
+	rdata = DNSRData()
+	(rest, rdata.cname) = dnsParseLabel(data, base)
+	if DEBUG_DNSCLIENT:
+		print "CNAME = \"%s\"." % (rdata.cname)
+	return rdata
+
+def dnsParseSOA(data, base):
+	rdata = DNSRData()
+	format = "!IIIII"
+	
+	(rest, rdata.mname) = dnsParseLabel(data, base)
+	if rdata.mname is None:
+		return None
+	(rest, rdata.rname) = dnsParseLabel(rest, base)
+	if rdata.rname is None:
+		return None
+	if len(rest) < struct.calcsize(format):
+		return None
+
+	(rdata.serial, rdata.refresh, rdata.retry, rdata.expire,
+		rdata.minimum) = struct.unpack(format, rest[:struct.calcsize(format)])
+	
+	if DEBUG_DNSCLIENT:
+		print "SOA(mname) = \"%s\"." % rdata.mname
+		print "SOA(rname) = \"%s\"." % rdata.rname
+		print "SOA(serial) = %d." % rdata.serial
+		print "SOA(refresh) = %d." % rdata.refresh
+		print "SOA(retry) = %d." % rdata.retry
+		print "SOA(expire) = %d." % rdata.expire
+		print "SOA(minimum) = %d." % rdata.minimum
+	return rdata
+
+def dnsParseNULL(data, base):
+	# um, yeah
+	return None
+
+def dnsParseWKS(data, base):
+	return None
+
+def dnsParseHINFO(data, base):
+	rdata = DNSRData()
+	(rest, rdata.cpu) = dnsParseText(data)
+	if rest:
+		(rest, rdata.os) = dnsParseText(rest)
+	if DEBUG_DNSCLIENT:
+		print "HINFO(cpu) = \"%s\"." % rdata.cpu
+		print "HINFO(os) = \"%s\"." % rdata.os
+	return rdata
+
+def dnsParseMX(data, base):
+	rdata = DNSRData()
+	if len(data) < 2:
+		return None
+	rdata.preference = (ord(data[0]) << 8) | ord(data[1])
+	(rest, rdata.exchange) = dnsParseLabel(data[2:], base)
+	if DEBUG_DNSCLIENT:
+		print "MX(exchanger) = \"%s\"." % rdata.exchange
+		print "MX(preference) = %d." % rdata.preference
+	return rdata
+
+def dnsParseTXT(data, base):
+	rdata = DNSRData()
+	(rest, rdata.data) = dnsParseText(data)
+	if DEBUG_DNSCLIENT:
+		print "TXT = \"%s\"." % rdata.data
+	return rdata
+
+def dnsParsePTR(data, base):
+	rdata = DNSRData()
+	(rest, rdata.ptrdname) = dnsParseLabel(data, base)
+	if DEBUG_DNSCLIENT:
+		print "PTR = \"%s\"." % rdata.ptrdname
+
+def dnsParseSRV(data, base):
+	rdata = DNSRData()
+	format = "!HHH"
+	flen = struct.calcsize(format)
+	if len(data) < flen:
+		return None
+		
+	(rdata.priority, rdata.weight, rdata.port) = struct.unpack(format, data[:flen])
+	(rest, rdata.server) = dnsParseLabel(data[flen:], base)
+	if DEBUG_DNSCLIENT:
+		print "SRV(server) = \"%s\"." % rdata.server
+		print "SRV(weight) = %d." % rdata.weight
+		print "SRV(priority) = %d." % rdata.priority
+		print "SRV(port) = %d." % rdata.port
+	return rdata
+
+def dnsParseResults(results):
+	try:
+		header = unpackQueryHeader(results)
+	except struct.error:
+		return []
+	
+	if header.dns_qr != 1: # should be a response
+		return []
+
+	if header.dns_rcode != 0: # should be no error
+		return []
+
+	rest = results[header.size():]
+	
+	rrlist = []
+
+	for i in xrange(header.dns_qdcount):
+		if not rest:
+			return []
+		
+		rr = DNSResult()
+
+		(rest, label) = dnsParseLabel(rest, results)
+		if label is None:
+			return []
+
+		if len(rest) < rr.qsize():
+			return []
+		
+		rr.qunpack(rest)
+		
+		rest = rest[rr.qsize():]
+
+		if DEBUG_DNSCLIENT:
+			print "Queried for '%s', class = %d, type = %d." % (label,
+				rr.dns_class, rr.dns_type)
+
+	for i in xrange(header.dns_ancount + header.dns_nscount + header.dns_arcount):
+		(rest, label) = dnsParseLabel(rest, results)
+		if label is None:
+			return []
+
+		rr = DNSResult()
+
+		rr.dns_name = label
+
+		if len(rest) < rr.size():
+			return []
+
+		rr.unpack(rest)
+		
+		rest = rest[rr.size():]
+
+		if DEBUG_DNSCLIENT:
+			print "Answer %d for '%s', class = %d, type = %d, ttl = %d." % (i,
+				rr.dns_name, rr.dns_class, rr.dns_type,
+				rr.dns_ttl)
+
+		if len(rest) < rr.dns_rlength:
+			if DEBUG_DNSCLIENT:
+				print "Answer too short."
+			return []
+		
+		fmap = { DNS_T_A: dnsParseA, DNS_T_NS: dnsParseNS,
+			DNS_T_CNAME: dnsParseCNAME, DNS_T_SOA: dnsParseSOA,
+			DNS_T_NULL: dnsParseNULL, DNS_T_WKS: dnsParseWKS,
+			DNS_T_PTR: dnsParsePTR, DNS_T_HINFO: dnsParseHINFO,
+			DNS_T_MX: dnsParseMX, DNS_T_TXT: dnsParseTXT,
+			DNS_T_SRV: dnsParseSRV}
+
+		if not rr.dns_type in fmap:
+			if DEBUG_DNSCLIENT:
+				print "Don't know how to parse RR type %d!" %	rr.dns_type
+		else:
+			rr.rdata = fmap[rr.dns_type](rest[:rr.dns_rlength], results)
+
+		rest = rest[rr.dns_rlength:]
+		rrlist += [rr]
+
+	if not rrlist:
+		rrlist = [rr]
+	return rrlist
+
+def query(query, qclass, qtype):
+	qdata = dnsFormatQuery(query, qclass, qtype)
+	if not qdata:
+		return []
+	answer = acutil.res_send(qdata)
+	if not answer:
+		return []
+	return dnsParseResults(answer)
+
+if __name__ == '__main__':
+	DEBUG_DNSCLIENT = True
+	print "Sending query."
+	rr = query(len(sys.argv) > 1 and sys.argv[1] or "devserv.devel.redhat.com.",
+		DNS_C_IN, DNS_T_ANY)
+	sys.exit(0)