added code that checks whether the DOMAIN<1b> name is claimed on the

local subnet _before_ going and registering it.  the reason for this
is that i don't want to cause chaos by registering the name twice.

it's ok to register DOMAIN<1b> with the WINS server, because the WINS
server's job is to check a) _if_ there's a current owner of the name
b) if the current owner exists c) if the current owner still wants the
name.  if they don't, the WINS server responds by saying, 'yes, you can
have it'.

lkcl
(This used to be commit 0d51899b59204b99d5aeb9542c8adfff42167fec)

3 files changed, 68 insertions, 7 deletions

diff --git a/source3/include/nameserv.h b/source3/include/nameserv.h
index 75461ce5e6..027931f9e6 100644
--- a/source3/include/nameserv.h
+++ b/source3/include/nameserv.h
@@ -123,7 +123,8 @@ enum state_type
 	NAME_QUERY_DOM_SRV_CHK,
 	NAME_QUERY_SRV_CHK,
 	NAME_QUERY_FIND_MST,
-	NAME_QUERY_MST_CHK
+	NAME_QUERY_MST_CHK,
+	NAME_QUERY_DOMAIN,
 };
 
 /* a netbios name structure */
diff --git a/source3/nameresp.c b/source3/nameresp.c
index 949bb366bb..77addc2985 100644
--- a/source3/nameresp.c
+++ b/source3/nameresp.c
@@ -160,6 +160,34 @@ static void dead_netbios_entry(struct subnet_record *d,
 	  break;
 	}
 
+	case NAME_QUERY_DOMAIN:
+	{
+	  /* if no response received, there is no domain controller on
+         this local subnet.  it's ok for us to register
+       */
+
+	  if (!n->bcast)
+	  {
+		 DEBUG(0,("NAME_QUERY_DOMAIN incorrectly used - contact samba-bugs!\n"));
+         /* XXXX whoops. someone's using this to unicast a packet.  this state
+            should only be used for broadcast checks
+          */
+         break;
+	  }
+	  if (n->num_msgs == 0)
+	  {
+	    if (ismyip(n->send_ip))
+	    {
+          struct work_record *work = find_workgroupstruct(d,n->name.name,False);
+          if (work && d)
+          {
+		    become_domain_master(d,work);
+          }
+        }
+	  }
+	  break;
+	}
+
 	default:
 	{
 	  /* nothing to do but delete the dead expected-response structure */
diff --git a/source3/nameserv.c b/source3/nameserv.c
index 7f1c0fadee..77c3906242 100644
--- a/source3/nameserv.c
+++ b/source3/nameserv.c
@@ -80,14 +80,18 @@ void remove_name_entry(struct subnet_record *d, char *name,int type)
      don't really own */  
   remove_netbios_name(d,name,type,SELF,n2->ip_flgs[0].ip);
 
-  if (ip_equal(d->bcast_ip, ipgrp)) {
-    if (!lp_wins_support()) {
+  if (ip_equal(d->bcast_ip, ipgrp))
+  {
+    if (!lp_wins_support())
+    {
       /* not a WINS server: we have to release them on the network */
       queue_netbios_pkt_wins(d,ClientNMB,NMB_REL,NAME_RELEASE,
 			     name, type, 0, 0,0,NULL,NULL,
 			     False, True, ipzero, ipzero);
     }
-  } else {
+  }
+  else
+  {
     /* local interface: release them on the network */
     queue_netbios_packet(d,ClientNMB,NMB_REL,NAME_RELEASE,
 			 name, type, 0, 0,0,NULL,NULL,
@@ -181,19 +185,47 @@ void add_domain_names(time_t t)
       make_nmb_name(&n,lp_workgroup(),0x1c,scope);
       if (!find_name(d->namelist, &n, FIND_SELF))
       {
+        /* logon servers are group names - we don't expect this to fail. */
         DEBUG(0,("%s attempting to become logon server for %s %s\n",
              timestring(), lp_workgroup(), inet_ntoa(d->bcast_ip)));
         become_logon_server(d, work);
       }
     }
+
     if (lp_domain_master() && work && work->dom_state == DOMAIN_NONE)
     {
       make_nmb_name(&n,lp_workgroup(),0x1b,scope);
       if (!find_name(d->namelist, &n, FIND_SELF))
       {
-        DEBUG(1,("%s attempting to become logon server for %s %s\n",
-             timestring(), lp_workgroup(), inet_ntoa(d->bcast_ip)));
-        become_domain_master(d, work);
+        if (ip_equal(d->bcast_ip,ipgrp))
+        {
+          if (lp_wins_support())
+          {
+            /* use the wins server's capabilities (indirectly).  if
+               someone has already register the domain<1b> name with 
+               the WINS server, then the WINS server's job is to _check_
+               that the owner still wants it, before giving it away.
+             */
+               
+            DEBUG(1,("%s initiating becoming logon server for %s %s\n",
+            		timestring(), lp_workgroup(), inet_ntoa(d->bcast_ip)));
+            become_domain_master(d, work);
+          }
+        }
+        else
+        {
+          /* send out a query to establish whether there's a 
+             domain controller on the local subnet.  if not,
+             we can become a domain controller on that subnet.
+             it's only polite that we check, before claiming the
+             NetBIOS name 0x1b.
+           */
+
+          queue_netbios_packet(d,ClientNMB,NMB_QUERY,NAME_QUERY_DOMAIN,
+          			lp_workgroup(), 0x1b,
+          			0, 0,0,NULL,NULL,
+          			True, True, d->bcast_ip, d->bcast_ip);
+        }
       }
     }
   }