#!/usr/bin/env python
+# vim: expandtab
#
# update our DNS names using TSIG-GSS
#
# ensure we get messages out immediately, so they get in the samba logs,
# and don't get swallowed by a timeout
-os.putenv('PYTHONUNBUFFERED', '1')
+os.environ['PYTHONUNBUFFERED'] = '1'
# forcing GMT avoids a problem in some timezones with kerberos. Both MIT
# heimdal can get mutual authentication errors due to the 24 second difference
# between UTC and GMT when using some zone files (eg. the PDT zone from
# the US)
-os.putenv("TZ", "GMT")
+os.environ["TZ"] = "GMT"
# Find right directory when running from source tree
sys.path.insert(0, "bin/python")
from samba.dcerpc import netlogon, winbind
samba.ensure_external_module("dns", "dnspython")
-import dns.resolver as resolver
+import dns.resolver
+import dns.exception
default_ttl = 900
am_rodc = False
parser.add_option("--all-interfaces", action="store_true")
parser.add_option("--use-file", type="string", help="Use a file, rather than real DNS calls")
parser.add_option("--update-list", type="string", help="Add DNS names from the given file")
+parser.add_option("--update-cache", type="string", help="Cache database of already registered records")
parser.add_option("--fail-immediately", action='store_true', help="Exit on first failure")
+parser.add_option("--no-credentials", dest='nocreds', action='store_true', help="don't try and get credentials")
+parser.add_option("--no-substiutions", dest='nosubs', action='store_true', help="don't try and expands variables in file specified by --update-list")
creds = None
ccachename = None
print "No IP interfaces - skipping DNS updates"
sys.exit(0)
+IP6s = []
+IP4s = []
+for i in IPs:
+ if i.find(':') != -1:
+ IP6s.append(i)
+ else:
+ IP4s.append(i)
+
+
if opts.verbose:
print "IPs: %s" % IPs
-########################################################
-# get credentials if we haven't got them already
+
def get_credentials(lp):
+ """# get credentials if we haven't got them already."""
from samba import credentials
global ccachename, creds
if creds is not None:
creds.set_machine_account(lp)
creds.set_krb_forwardable(credentials.NO_KRB_FORWARDABLE)
(tmp_fd, ccachename) = tempfile.mkstemp()
- creds.get_named_ccache(lp, ccachename)
+ try:
+ creds.get_named_ccache(lp, ccachename)
+ except RuntimeError as e:
+ os.unlink(ccachename)
+ raise e
-#############################################
-# an object to hold a parsed DNS line
class dnsobj(object):
+ """an object to hold a parsed DNS line"""
+
def __init__(self, string_form):
list = string_form.split()
+ if len(list) < 3:
+ raise Exception("Invalid DNS entry %r" % string_form)
self.dest = None
self.port = None
self.ip = None
self.existing_port = None
self.existing_weight = None
self.type = list[0]
- self.name = list[1].lower()
+ self.name = list[1]
if self.type == 'SRV':
- self.dest = list[2].lower()
+ if len(list) < 4:
+ raise Exception("Invalid DNS entry %r" % string_form)
+ self.dest = list[2]
self.port = list[3]
- elif self.type == 'A':
+ elif self.type in ['A', 'AAAA']:
self.ip = list[2] # usually $IP, which gets replaced
elif self.type == 'CNAME':
- self.dest = list[2].lower()
+ self.dest = list[2]
+ elif self.type == 'NS':
+ self.dest = list[2]
else:
- print "Received unexpected DNS reply of type %s" % self.type
- raise
+ raise Exception("Received unexpected DNS reply of type %s: %s" % (self.type, string_form))
def __str__(self):
- if d.type == "A": return "%s %s %s" % (self.type, self.name, self.ip)
- if d.type == "SRV": return "%s %s %s %s" % (self.type, self.name, self.dest, self.port)
- if d.type == "CNAME": return "%s %s %s" % (self.type, self.name, self.dest)
+ if self.type == "A":
+ return "%s %s %s" % (self.type, self.name, self.ip)
+ if self.type == "AAAA":
+ return "%s %s %s" % (self.type, self.name, self.ip)
+ if self.type == "SRV":
+ return "%s %s %s %s" % (self.type, self.name, self.dest, self.port)
+ if self.type == "CNAME":
+ return "%s %s %s" % (self.type, self.name, self.dest)
+ if self.type == "NS":
+ return "%s %s %s" % (self.type, self.name, self.dest)
-################################################
-# parse a DNS line from
def parse_dns_line(line, sub_vars):
+ """parse a DNS line from."""
+ if line.startswith("SRV _ldap._tcp.pdc._msdcs.") and not samdb.am_pdc():
+ if opts.verbose:
+ print "Skipping PDC entry (%s) as we are not a PDC" % line
+ return None
subline = samba.substitute_var(line, sub_vars)
- d = dnsobj(subline)
- return d
+ return dnsobj(subline)
+
-############################################
-# see if two hostnames match
def hostname_match(h1, h2):
+ """see if two hostnames match."""
h1 = str(h1)
h2 = str(h2)
return h1.lower().rstrip('.') == h2.lower().rstrip('.')
-############################################
-# check that a DNS entry exists
def check_dns_name(d):
+ """check that a DNS entry exists."""
normalised_name = d.name.rstrip('.') + '.'
if opts.verbose:
print "Looking for DNS entry %s as %s" % (d, normalised_name)
-
+
if opts.use_file is not None:
try:
dns_file = open(opts.use_file, "r")
except IOError:
return False
-
+
for line in dns_file:
line = line.strip()
if line == '' or line[0] == "#":
return True
return False
+ resolver = dns.resolver.Resolver()
+ if d.type == "NS":
+ # we need to lookup the nameserver for the parent domain,
+ # and use that to check the NS record
+ parent_domain = '.'.join(normalised_name.split('.')[1:])
+ try:
+ ans = resolver.query(parent_domain, 'NS')
+ except dns.exception.DNSException:
+ if opts.verbose:
+ print "Failed to find parent NS for %s" % d
+ return False
+ nameservers = set()
+ for i in range(len(ans)):
+ try:
+ ns = resolver.query(str(ans[i]), 'A')
+ except dns.exception.DNSException:
+ continue
+ for j in range(len(ns)):
+ nameservers.add(str(ns[j]))
+ d.nameservers = list(nameservers)
+
try:
+ if getattr(d, 'nameservers', None):
+ resolver.nameservers = list(d.nameservers)
ans = resolver.query(normalised_name, d.type)
- except resolver.NXDOMAIN:
+ except dns.exception.DNSException:
+ if opts.verbose:
+ print "Failed to find DNS entry %s" % d
return False
- if d.type == 'A':
+ if d.type in ['A', 'AAAA']:
# we need to be sure that our IP is there
for rdata in ans:
if str(rdata) == str(d.ip):
return True
- if d.type == 'CNAME':
+ elif d.type == 'CNAME':
+ for i in range(len(ans)):
+ if hostname_match(ans[i].target, d.dest):
+ return True
+ elif d.type == 'NS':
for i in range(len(ans)):
if hostname_match(ans[i].target, d.dest):
return True
- if d.type == 'SRV':
+ elif d.type == 'SRV':
for rdata in ans:
if opts.verbose:
print "Checking %s against %s" % (rdata, d)
else:
d.existing_port = str(rdata.port)
d.existing_weight = str(rdata.weight)
+
if opts.verbose:
- print "Failed to find DNS entry %s" % d
+ print "Failed to find matching DNS entry %s" % d
return False
-###########################################
-# get the list of substitution vars
-def get_subst_vars():
+def get_subst_vars(samdb):
+ """get the list of substitution vars."""
global lp, am_rodc
vars = {}
- samdb = SamDB(url=lp.get("sam database"), session_info=system_session(),
- lp=lp)
-
- vars['DNSDOMAIN'] = lp.get('realm').lower()
- vars['DNSFOREST'] = lp.get('realm').lower()
- vars['HOSTNAME'] = lp.get('netbios name').lower() + "." + vars['DNSDOMAIN']
+ vars['DNSDOMAIN'] = samdb.domain_dns_name()
+ vars['DNSFOREST'] = samdb.forest_dns_name()
+ vars['HOSTNAME'] = samdb.host_dns_name()
vars['NTDSGUID'] = samdb.get_ntds_GUID()
vars['SITE'] = samdb.server_site_name()
- res = samdb.search(base=None, scope=SCOPE_BASE, attrs=["objectGUID"])
+ res = samdb.search(base=samdb.get_default_basedn(), scope=SCOPE_BASE, attrs=["objectGUID"])
guid = samdb.schema_format_value("objectGUID", res[0]['objectGUID'][0])
vars['DOMAINGUID'] = guid
am_rodc = samdb.am_rodc()
return vars
-############################################
-# call nsupdate for an entry
-def call_nsupdate(d):
- global ccachename, nsupdate_cmd
+def call_nsupdate(d, op="add"):
+ """call nsupdate for an entry."""
+ global ccachename, nsupdate_cmd, krb5conf
+
+ assert(op in ["add", "delete"])
if opts.verbose:
- print "Calling nsupdate for %s" % d
+ print "Calling nsupdate for %s (%s)" % (d, op)
if opts.use_file is not None:
- wfile = open(opts.use_file, 'a')
- fcntl.lockf(wfile, fcntl.LOCK_EX)
- wfile.write(str(d)+"\n")
- fcntl.lockf(wfile, fcntl.LOCK_UN)
+ try:
+ rfile = open(opts.use_file, 'r+')
+ except IOError:
+ # Perhaps create it
+ rfile = open(opts.use_file, 'w+')
+ # Open it for reading again, in case someone else got to it first
+ rfile = open(opts.use_file, 'r+')
+ fcntl.lockf(rfile, fcntl.LOCK_EX)
+ (file_dir, file_name) = os.path.split(opts.use_file)
+ (tmp_fd, tmpfile) = tempfile.mkstemp(dir=file_dir, prefix=file_name, suffix="XXXXXX")
+ wfile = os.fdopen(tmp_fd, 'a')
+ rfile.seek(0)
+ for line in rfile:
+ if op == "delete":
+ l = parse_dns_line(line, {})
+ if str(l).lower() == str(d).lower():
+ continue
+ wfile.write(line)
+ if op == "add":
+ wfile.write(str(d)+"\n")
+ os.rename(tmpfile, opts.use_file)
+ fcntl.lockf(rfile, fcntl.LOCK_UN)
return
normalised_name = d.name.rstrip('.') + '.'
(tmp_fd, tmpfile) = tempfile.mkstemp()
f = os.fdopen(tmp_fd, 'w')
+ if getattr(d, 'nameservers', None):
+ f.write('server %s\n' % d.nameservers[0])
if d.type == "A":
- f.write("update add %s %u A %s\n" % (normalised_name, default_ttl, d.ip))
+ f.write("update %s %s %u A %s\n" % (op, normalised_name, default_ttl, d.ip))
+ if d.type == "AAAA":
+ f.write("update %s %s %u AAAA %s\n" % (op, normalised_name, default_ttl, d.ip))
if d.type == "SRV":
- if d.existing_port is not None:
+ if op == "add" and d.existing_port is not None:
f.write("update delete %s SRV 0 %s %s %s\n" % (normalised_name, d.existing_weight,
d.existing_port, d.dest))
- f.write("update add %s %u SRV 0 100 %s %s\n" % (normalised_name, default_ttl, d.port, d.dest))
+ f.write("update %s %s %u SRV 0 100 %s %s\n" % (op, normalised_name, default_ttl, d.port, d.dest))
if d.type == "CNAME":
- f.write("update add %s %u CNAME %s\n" % (normalised_name, default_ttl, d.dest))
+ f.write("update %s %s %u CNAME %s\n" % (op, normalised_name, default_ttl, d.dest))
+ if d.type == "NS":
+ f.write("update %s %s %u NS %s\n" % (op, normalised_name, default_ttl, d.dest))
if opts.verbose:
f.write("show\n")
f.write("send\n")
f.close()
- os.putenv("KRB5CCNAME", ccachename)
+ global error_count
+ if ccachename:
+ os.environ["KRB5CCNAME"] = ccachename
try:
- cmd = "%s %s" % (nsupdate_cmd, tmpfile)
- subprocess.check_call(cmd, shell=True)
- except subprocess.CalledProcessError:
- global error_count
+ cmd = nsupdate_cmd[:]
+ cmd.append(tmpfile)
+ env = {}
+ if krb5conf:
+ env["KRB5_CONFIG"] = krb5conf
+ if ccachename:
+ env["KRB5CCNAME"] = ccachename
+ ret = subprocess.call(cmd, shell=False, env=env)
+ if ret != 0:
+ if opts.fail_immediately:
+ if opts.verbose:
+ print("Failed update with %s" % tmpfile)
+ sys.exit(1)
+ error_count = error_count + 1
+ if opts.verbose:
+ print("Failed nsupdate: %d" % ret)
+ except Exception, estr:
if opts.fail_immediately:
sys.exit(1)
error_count = error_count + 1
+ if opts.verbose:
+ print("Failed nsupdate: %s : %s" % (str(d), estr))
os.unlink(tmpfile)
-def rodc_dns_update(d, t):
+def rodc_dns_update(d, t, op):
'''a single DNS update via the RODC netlogon call'''
global sub_vars
+ assert(op in ["add", "delete"])
+
if opts.verbose:
print "Calling netlogon RODC update for %s" % d
name.weight = 0
if d.port is not None:
name.port = int(d.port)
- name.dns_register = True
+ if op == "add":
+ name.dns_register = True
+ else:
+ name.dns_register = False
dns_names.names = [ name ]
site_name = sub_vars['SITE'].decode('utf-8')
+ global error_count
+
try:
ret_names = w.DsrUpdateReadOnlyServerDnsRecords(site_name, default_ttl, dns_names)
if ret_names.names[0].status != 0:
print("Failed to set DNS entry: %s (status %u)" % (d, ret_names.names[0].status))
+ error_count = error_count + 1
except RuntimeError, reason:
print("Error setting DNS entry of type %u: %s: %s" % (t, d, reason))
+ error_count = error_count + 1
+
+ if error_count != 0 and opts.fail_immediately:
+ sys.exit(1)
-def call_rodc_update(d):
+def call_rodc_update(d, op="add"):
'''RODCs need to use the netlogon API for nsupdate'''
global lp, sub_vars
+ assert(op in ["add", "delete"])
+
# we expect failure for 3268 if we aren't a GC
if d.port is not None and int(d.port) == 3268:
return
subname = samba.substitute_var(map[t], sub_vars)
if subname.lower() == d.name.lower():
# found a match - do the update
- rodc_dns_update(d, t)
+ rodc_dns_update(d, t, op)
return
if opts.verbose:
print("Unable to map to netlogon DNS update: %s" % d)
else:
dns_update_list = lp.private_path('dns_update_list')
+if opts.update_cache:
+ dns_update_cache = opts.update_cache
+else:
+ dns_update_cache = lp.private_path('dns_update_cache')
+
# use our private krb5.conf to avoid problems with the wrong domain
# bind9 nsupdate wants the default domain set
krb5conf = lp.private_path('krb5.conf')
-os.putenv('KRB5_CONFIG', krb5conf)
+os.environ['KRB5_CONFIG'] = krb5conf
file = open(dns_update_list, "r")
-# get the substitution dictionary
-sub_vars = get_subst_vars()
+if opts.nosubs:
+ sub_vars = {}
+else:
+ samdb = SamDB(url=lp.samdb_url(), session_info=system_session(), lp=lp)
+
+ # get the substitution dictionary
+ sub_vars = get_subst_vars(samdb)
# build up a list of update commands to pass to nsupdate
update_list = []
dns_list = []
+cache_list = []
+delete_list = []
+
+dup_set = set()
+cache_set = set()
+
+rebuild_cache = False
+try:
+ cfile = open(dns_update_cache, 'r+')
+except IOError:
+ # Perhaps create it
+ cfile = open(dns_update_cache, 'w+')
+ # Open it for reading again, in case someone else got to it first
+ cfile = open(dns_update_cache, 'r+')
+fcntl.lockf(cfile, fcntl.LOCK_EX)
+for line in cfile:
+ line = line.strip()
+ if line == '' or line[0] == "#":
+ continue
+ c = parse_dns_line(line, {})
+ if c is None:
+ continue
+ if str(c) not in cache_set:
+ cache_list.append(c)
+ cache_set.add(str(c))
# read each line, and check that the DNS name exists
for line in file:
if line == '' or line[0] == "#":
continue
d = parse_dns_line(line, sub_vars)
- dns_list.append(d)
+ if d is None:
+ continue
+ if d.type == 'A' and len(IP4s) == 0:
+ continue
+ if d.type == 'AAAA' and len(IP6s) == 0:
+ continue
+ if str(d) not in dup_set:
+ dns_list.append(d)
+ dup_set.add(str(d))
# now expand the entries, if any are A record with ip set to $IP
# then replace with multiple entries, one for each interface IP
for d in dns_list:
- if d.type == 'A' and d.ip == "$IP":
- d.ip = IPs[0]
- for i in range(len(IPs)-1):
+ if d.ip != "$IP":
+ continue
+ if d.type == 'A':
+ d.ip = IP4s[0]
+ for i in range(len(IP4s)-1):
+ d2 = dnsobj(str(d))
+ d2.ip = IP4s[i+1]
+ dns_list.append(d2)
+ if d.type == 'AAAA':
+ d.ip = IP6s[0]
+ for i in range(len(IP6s)-1):
d2 = dnsobj(str(d))
- d2.ip = IPs[i+1]
+ d2.ip = IP6s[i+1]
dns_list.append(d2)
# now check if the entries already exist on the DNS server
for d in dns_list:
+ found = False
+ for c in cache_list:
+ if str(c).lower() == str(d).lower():
+ found = True
+ break
+ if not found:
+ rebuild_cache = True
if opts.all_names or not check_dns_name(d):
update_list.append(d)
-if len(update_list) == 0:
+for c in cache_list:
+ found = False
+ for d in dns_list:
+ if str(c).lower() == str(d).lower():
+ found = True
+ break
+ if found:
+ continue
+ rebuild_cache = True
+ if not opts.all_names and not check_dns_name(c):
+ continue
+ delete_list.append(c)
+
+if len(delete_list) == 0 and len(update_list) == 0 and not rebuild_cache:
if opts.verbose:
print "No DNS updates needed"
sys.exit(0)
# get our krb5 creds
-get_credentials(lp)
+if len(delete_list) != 0 or len(update_list) != 0:
+ if not opts.nocreds:
+ get_credentials(lp)
+
+# ask nsupdate to delete entries as needed
+for d in delete_list:
+ if am_rodc:
+ if d.name.lower() == domain.lower():
+ continue
+ if not d.type in [ 'A', 'AAAA' ]:
+ call_rodc_update(d, op="delete")
+ else:
+ call_nsupdate(d, op="delete")
+ else:
+ call_nsupdate(d, op="delete")
# ask nsupdate to add entries as needed
for d in update_list:
if am_rodc:
if d.name.lower() == domain.lower():
continue
- if d.type != 'A':
+ if not d.type in [ 'A', 'AAAA' ]:
call_rodc_update(d)
else:
call_nsupdate(d)
else:
call_nsupdate(d)
+if rebuild_cache:
+ (file_dir, file_name) = os.path.split(dns_update_cache)
+ (tmp_fd, tmpfile) = tempfile.mkstemp(dir=file_dir, prefix=file_name, suffix="XXXXXX")
+ wfile = os.fdopen(tmp_fd, 'a')
+ for d in dns_list:
+ wfile.write(str(d)+"\n")
+ os.rename(tmpfile, dns_update_cache)
+fcntl.lockf(cfile, fcntl.LOCK_UN)
+
# delete the ccache if we created it
if ccachename is not None:
os.unlink(ccachename)
+if error_count != 0:
+ print("Failed update of %u entries" % error_count)
sys.exit(error_count)
git.samba.org / samba.git / blobdiff