s4-samba-tool: Provide a samba-tool domain dcpromo that upgrades a member to a DC

This command is like dcpromo in that it upgrades the existing workstation account
to be a domain controller.

The SID (and therefore any file ownerships) is preserved.

Andrew Bartlett

source4/scripting/python/samba/join.py

@@ -47,8 +47,9 @@ class dc_join(object):
     '''perform a DC join'''
 
     def __init__(ctx, server=None, creds=None, lp=None, site=None,
-            netbios_name=None, targetdir=None, domain=None,
+                 netbios_name=None, targetdir=None, domain=None,
-            machinepass=None, use_ntvfs=False, dns_backend=None):
+                 machinepass=None, use_ntvfs=False, dns_backend=None,
+                 promote_existing=False):
         ctx.creds = creds
         ctx.lp = lp
         ctx.site = site
@@ -60,6 +61,9 @@ class dc_join(object):
         else:
             ctx.dns_backend = dns_backend
 
+        ctx.promote_existing = promote_existing
+        ctx.promote_from_dn = None
+
         ctx.nc_list = []
         ctx.full_nc_list = []
 
@@ -203,6 +207,25 @@ class dc_join(object):
         except Exception:
             pass
 
+    def promote_possible(ctx):
+        '''confirm that the account is just a bare NT4 BDC or a member server, so can be safely promoted'''
+        if ctx.subdomain:
+            # This shouldn't happen
+            raise Exception("Can not promote into a subdomain")
+
+        res = ctx.samdb.search(base=ctx.samdb.get_default_basedn(),
+                               expression='sAMAccountName=%s' % ldb.binary_encode(ctx.samname),
+                               attrs=["msDS-krbTgtLink", "userAccountControl", "serverReferenceBL", "rIDSetReferences"])
+        if len(res) == 0:
+            raise Exception("Could not find domain member account '%s' to promote to a DC, use 'samba-tool domain join' instead'" % ctx.samname)
+        if "msDS-krbTgtLink" in res[0] or "serverReferenceBL" in res[0] or "rIDSetReferences" in res[0]:
+            raise Exception("Account '%s' appears to be an active DC, use 'samba-tool domain join' if you must re-create this account" % ctx.samname)
+        if (int(res[0]["userAccountControl"][0]) & (samba.dsdb.UF_WORKSTATION_TRUST_ACCOUNT|samba.dsdb.UF_SERVER_TRUST_ACCOUNT) == 0):
+            raise Exception("Account %s is not a domain member or a bare NT4 BDC, use 'samba-tool domain join' instead'" % ctx.samname)
+        
+        ctx.promote_from_dn = res[0].dn
+
+
     def find_dc(ctx, domain):
         '''find a writeable DC for the given domain'''
         try:
@@ -439,13 +462,29 @@ class dc_join(object):
                 "dnshostname" : ctx.dnshostname}
             if ctx.behavior_version >= samba.dsdb.DS_DOMAIN_FUNCTION_2008:
                 rec['msDS-SupportedEncryptionTypes'] = str(samba.dsdb.ENC_ALL_TYPES)
+            elif ctx.promote_existing:
+                rec['msDS-SupportedEncryptionTypes'] = []
             if ctx.managedby:
                 rec["managedby"] = ctx.managedby
+            elif ctx.promote_existing:
+                rec["managedby"] = []
+
             if ctx.never_reveal_sid:
                 rec["msDS-NeverRevealGroup"] = ctx.never_reveal_sid
+            elif ctx.promote_existing:
+                rec["msDS-NeverRevealGroup"] = []
+                
             if ctx.reveal_sid:
                 rec["msDS-RevealOnDemandGroup"] = ctx.reveal_sid
-            ctx.samdb.add(rec)
+            elif ctx.promote_existing:
+                rec["msDS-RevealOnDemandGroup"] = []
+
+            if ctx.promote_existing:
+                if ctx.promote_from_dn != ctx.acct_dn:
+                    ctx.samdb.rename(ctx.promote_from_dn, ctx.acct_dn)
+                ctx.samdb.modify(ldb.Message.from_dict(ctx.samdb, rec, ldb.FLAG_MOD_REPLACE))
+            else:
+                ctx.samdb.add(rec)
 
         if ctx.krbtgt_dn:
             ctx.add_krbtgt_account()
@@ -490,7 +529,7 @@ class dc_join(object):
             for i in range(len(ctx.SPNs)):
                 ctx.SPNs[i] = ctx.SPNs[i].replace("$NTDSGUID", str(ctx.ntds_guid))
             m["servicePrincipalName"] = ldb.MessageElement(ctx.SPNs,
-                                                           ldb.FLAG_MOD_ADD,
+                                                           ldb.FLAG_MOD_REPLACE,
                                                            "servicePrincipalName")
             ctx.samdb.modify(m)
 
@@ -908,8 +947,11 @@ class dc_join(object):
             ctx.full_nc_list += ['DC=ForestDnsZones,%s' % ctx.root_dn]
             ctx.nc_list += ['DC=ForestDnsZones,%s' % ctx.root_dn]
 
-
+        if ctx.promote_existing:
-        ctx.cleanup_old_join()
+            ctx.promote_possible()
+        else:
+            ctx.cleanup_old_join()
+            
         try:
             ctx.join_add_objects()
             ctx.join_provision()
@@ -927,11 +969,12 @@ class dc_join(object):
 
 def join_RODC(server=None, creds=None, lp=None, site=None, netbios_name=None,
               targetdir=None, domain=None, domain_critical_only=False,
-              machinepass=None, use_ntvfs=False, dns_backend=None):
+              machinepass=None, use_ntvfs=False, dns_backend=None,
+              promote_existing=False):
     """join as a RODC"""
 
     ctx = dc_join(server, creds, lp, site, netbios_name, targetdir, domain,
-                  machinepass, use_ntvfs, dns_backend)
+                  machinepass, use_ntvfs, dns_backend, promote_existing)
 
     lp.set("workgroup", ctx.domain_name)
     print("workgroup is %s" % ctx.domain_name)
@@ -981,10 +1024,11 @@ def join_RODC(server=None, creds=None, lp=None, site=None, netbios_name=None,
 
 def join_DC(server=None, creds=None, lp=None, site=None, netbios_name=None,
             targetdir=None, domain=None, domain_critical_only=False,
-            machinepass=None, use_ntvfs=False, dns_backend=None):
+            machinepass=None, use_ntvfs=False, dns_backend=None,
+            promote_existing=False):
     """join as a DC"""
     ctx = dc_join(server, creds, lp, site, netbios_name, targetdir, domain,
-                  machinepass, use_ntvfs, dns_backend)
+                  machinepass, use_ntvfs, dns_backend, promote_existing)
 
     lp.set("workgroup", ctx.domain_name)
     print("workgroup is %s" % ctx.domain_name)

source4/scripting/python/samba/netcmd/domain.py

@@ -126,6 +126,72 @@ class cmd_domain_info(Command):
             raise CommandError("Invalid IP address '" + address + "'!")
 
 
+class cmd_domain_dcpromo(Command):
+    """Promotes an existing domain member or NT4 PDC to an AD DC"""
+
+    synopsis = "%prog <dnsdomain> [DC|RODC] [options]"
+
+    takes_optiongroups = {
+        "sambaopts": options.SambaOptions,
+        "versionopts": options.VersionOptions,
+        "credopts": options.CredentialsOptions,
+    }
+
+    takes_options = [
+        Option("--server", help="DC to join", type=str),
+        Option("--site", help="site to join", type=str),
+        Option("--targetdir", help="where to store provision", type=str),
+        Option("--domain-critical-only",
+               help="only replicate critical domain objects",
+               action="store_true"),
+        Option("--machinepass", type=str, metavar="PASSWORD",
+               help="choose machine password (otherwise random)"),
+        Option("--use-ntvfs", help="Use NTVFS for the fileserver (default = no)",
+               action="store_true"),
+        Option("--dns-backend", type="choice", metavar="NAMESERVER-BACKEND",
+               choices=["SAMBA_INTERNAL", "BIND9_DLZ", "NONE"],
+               help="The DNS server backend. SAMBA_INTERNAL is the builtin name server, " \
+                   "BIND9_DLZ uses samba4 AD to store zone information (default), " \
+                   "NONE skips the DNS setup entirely (this DC will not be a DNS server)",
+               default="BIND9_DLZ")
+       ]
+
+    takes_args = ["domain", "role?"]
+
+    def run(self, domain, role=None, sambaopts=None, credopts=None,
+            versionopts=None, server=None, site=None, targetdir=None,
+            domain_critical_only=False, parent_domain=None, machinepass=None,
+            use_ntvfs=False, dns_backend=None):
+        lp = sambaopts.get_loadparm()
+        creds = credopts.get_credentials(lp)
+        net = Net(creds, lp, server=credopts.ipaddress)
+
+        if site is None:
+            site = "Default-First-Site-Name"
+
+        netbios_name = lp.get("netbios name")
+
+        if not role is None:
+            role = role.upper()
+
+        if role == "DC":
+            join_DC(server=server, creds=creds, lp=lp, domain=domain,
+                    site=site, netbios_name=netbios_name, targetdir=targetdir,
+                    domain_critical_only=domain_critical_only,
+                    machinepass=machinepass, use_ntvfs=use_ntvfs, dns_backend=dns_backend, 
+                    promote_existing=True)
+            return
+        elif role == "RODC":
+            join_RODC(server=server, creds=creds, lp=lp, domain=domain,
+                      site=site, netbios_name=netbios_name, targetdir=targetdir,
+                      domain_critical_only=domain_critical_only,
+                      machinepass=machinepass, use_ntvfs=use_ntvfs, dns_backend=dns_backend,
+                      promote_existing=True)
+            return
+        else:
+            raise CommandError("Invalid role '%s' (possible values: DC, RODC)" % role)
+
+
 class cmd_domain_join(Command):
     """Joins domain as either member or backup domain controller"""
 
@@ -953,6 +1019,7 @@ class cmd_domain(SuperCommand):
         subcommands["exportkeytab"] = cmd_domain_export_keytab()
     subcommands["info"] = cmd_domain_info()
     subcommands["join"] = cmd_domain_join()
+    subcommands["dcpromo"] = cmd_domain_dcpromo()
     subcommands["level"] = cmd_domain_level()
     subcommands["passwordsettings"] = cmd_domain_passwordsettings()
     subcommands["classicupgrade"] = cmd_domain_classicupgrade()