Bug report 1079 and fix both from Bert Driehuis.

This is an odd corner case having to do with <1C> group names (DC names).
<1C> group names are called (by MS) "Internet Special Groups", which means
that Microsoft's WINS servers will attempt to handle these names in
something approximating an RFC1001/1002 compliant manner.

The problem being reported here is this:  If an initial registration sent
by one of the group members is lost (network error, whatever) then
subsequent refreshes from that particular machine will also fail.  This
only happens if the name is already active (because of other group
members).

In most cases, we (and MS) handle refreshes as registrations if the name
is not in the database.  In this situation, we missed the corner case.

Bert's fix adds an 'else if' that catches the situation in which a refresh
for an unlisted IP of an active <1C> group name is received.  The refresh
is simply handled as a registration when this happens.

[Note: Committing in HEAD.  I am writing some tools to do registrations
       and refreshes so that I can test this.  I don't have an NT Domain
       for testing so I'm going to have to fudge.  This fix is small (I
       cleaned up some Debug messages and comments in addition to the fix)
       and if you want to test it with 3.0.x you can just copy the HEAD
       version into your 3.0.x tree and recompile.]
(This used to be commit 8e52439f4ae9de84107e2d0e9f33f0d4e3c5945a)

1 files changed, 78 insertions, 38 deletions

diff --git a/source3/nmbd/nmbd_winsserver.c b/source3/nmbd/nmbd_winsserver.c
index 3694072420..aae1cf633f 100644
--- a/source3/nmbd/nmbd_winsserver.c
+++ b/source3/nmbd/nmbd_winsserver.c
@@ -440,8 +440,8 @@ static void send_wins_name_registration_response(int rcode, int ttl, struct pack
  Deal with a name refresh request to a WINS server.
 ************************************************************************/
 
-void wins_process_name_refresh_request(struct subnet_record *subrec,
-                                            struct packet_struct *p)
+void wins_process_name_refresh_request( struct subnet_record *subrec,
+                                        struct packet_struct *p )
 {
 	struct nmb_packet *nmb = &p->packet.nmb;
 	struct nmb_name *question = &nmb->question.question_name;
@@ -453,28 +453,36 @@ void wins_process_name_refresh_request(struct subnet_record *subrec,
 	struct in_addr from_ip;
 	struct in_addr our_fake_ip = *interpret_addr2("0.0.0.0");
 
-	putip((char *)&from_ip,&nmb->additional->rdata[2]);
+	putip( (char *)&from_ip, &nmb->additional->rdata[2] );
 
 	if(bcast) {
 		/*
 		 * We should only get unicast name refresh packets here.
-		 * Anyone trying to refresh broadcast should not be going to a WINS
-		 * server. Log an error here.
+		 * Anyone trying to refresh broadcast should not be going
+		 * to a WINS server.  Log an error here.
 		 */
-
-		DEBUG(0,("wins_process_name_refresh_request: broadcast name refresh request \
-received for name %s from IP %s on subnet %s. Error - should not be sent to WINS server\n",
-			nmb_namestr(question), inet_ntoa(from_ip), subrec->subnet_name));
+		if( DEBUGLVL( 0 ) ) {
+			dbgtext( "wins_process_name_refresh_request: " );
+			dbgtext( "Broadcast name refresh request received " );
+			dbgtext( "for name %s ", nmb_namestr(question) );
+			dbgtext( "from IP %s ", inet_ntoa(from_ip) );
+			dbgtext( "on subnet %s.  ", subrec->subnet_name );
+			dbgtext( "Error - Broadcasts should not be sent " );
+			dbgtext( "to a WINS server\n" );
+		}
 		return;
 	}
 
-	DEBUG(3,("wins_process_name_refresh_request: Name refresh for name %s \
-IP %s\n", nmb_namestr(question), inet_ntoa(from_ip) ));
+	if( DEBUGLVL( 3 ) ) {
+		dbgtext( "wins_process_name_refresh_request: " );
+		dbgtext( "Name refresh for name %s IP %s\n",
+			 nmb_namestr(question), inet_ntoa(from_ip) );
+	}
 
 	/* 
 	 * See if the name already exists.
+	 * If not, handle it as a name registration and return.
 	 */
-
 	namerec = find_name_on_subnet(subrec, question, FIND_ANY_NAME);
 
 	/*
@@ -482,48 +490,62 @@ IP %s\n", nmb_namestr(question), inet_ntoa(from_ip) ));
 	 * treat it like a registration request. This allows us to recover 
 	 * from errors (tridge)
 	 */
-
 	if(namerec == NULL) {
-		DEBUG(3,("wins_process_name_refresh_request: Name refresh for name %s and \
-the name does not exist. Treating as registration.\n", nmb_namestr(question) ));
+		if( DEBUGLVL( 3 ) ) {
+			dbgtext( "wins_process_name_refresh_request: " );
+			dbgtext( "Name refresh for name %s ",
+				 nmb_namestr( question ) );
+			dbgtext( "and the name does not exist.  Treating " );
+			dbgtext( "as registration.\n" );
+		}
 		wins_process_name_registration_request(subrec,p);
 		return;
 	}
 
 	/*
-	 * if the name is present but not active,
-	 * simply remove it and treat the request
-	 * as a registration
+	 * if the name is present but not active, simply remove it
+	 * and treat the refresh request as a registration & return.
 	 */
 	if (namerec != NULL && !WINS_STATE_ACTIVE(namerec)) {
-		DEBUG(5,("wins_process_name_refresh_request: Name (%s) in WINS was \
-not active - removing it.\n", nmb_namestr(question) ));
+		if( DEBUGLVL( 5 ) ) {
+			dbgtext( "wins_process_name_refresh_request: " );
+			dbgtext( "Name (%s) in WINS ", nmb_namestr(question) );
+			dbgtext( "was not active - removing it.\n" );
+		}
 		remove_name_from_namelist( subrec, namerec );
 		namerec = NULL;
-		wins_process_name_registration_request(subrec,p);
+		wins_process_name_registration_request( subrec, p );
 		return;
 	}
 
 	/*
 	 * Check that the group bits for the refreshing name and the
-	 * name in our database match.
+	 * name in our database match.  If not, refuse the refresh.
+	 * [crh:  Why RFS_ERR instead of ACT_ERR? Is this what MS does?]
 	 */
-
-	if((namerec != NULL) && ((group && !NAME_GROUP(namerec)) || (!group && NAME_GROUP(namerec))) ) {
-		DEBUG(3,("wins_process_name_refresh_request: Name %s group bit = %s \
-does not match group bit in WINS for this name.\n", nmb_namestr(question), group ? "True" : "False" ));
+	if( (namerec != NULL) &&
+	    ( (group && !NAME_GROUP(namerec))
+	   || (!group && NAME_GROUP(namerec)) ) ) {
+		if( DEBUGLVL( 3 ) ) {
+			dbgtext( "wins_process_name_refresh_request: " );
+			dbgtext( "Name %s ", nmb_namestr(question) );
+			dbgtext( "group bit = %s does not match ",
+				 group ? "True" : "False" );
+			dbgtext( "group bit in WINS for this name.\n" );
+		}
 		send_wins_name_registration_response(RFS_ERR, 0, p);
 		return;
 	}
 
 	/*
-	 * For a unique name check that the person refreshing the name is one of the registered IP
-	 * addresses. If not - fail the refresh. Do the same for group names with a type of 0x1c.
-	 * Just return success for unique 0x1d refreshes. For normal group names update the ttl
-	 * and return success.
+	 * For a unique name check that the person refreshing the name is
+	 * one of the registered IP addresses. If not - fail the refresh.
+	 * Do the same for group names with a type of 0x1c.
+	 * Just return success for unique 0x1d refreshes. For normal group
+	 * names update the ttl and return success.
 	 */
-
-	if((!group || (group && (question->name_type == 0x1c))) && find_ip_in_name_record(namerec, from_ip )) {
+	if( (!group || (group && (question->name_type == 0x1c)))
+	 && find_ip_in_name_record(namerec, from_ip) ) {
 		/*
 		 * Update the ttl.
 		 */
@@ -541,11 +563,26 @@ does not match group bit in WINS for this name.\n", nmb_namestr(question), group
 		send_wins_name_registration_response(0, ttl, p);
 		wins_hook("refresh", namerec, ttl);
 		return;
+	} else if((group && (question->name_type == 0x1c))) {
+		/*
+		 * Added by crh for bug #1079.
+		 * Fix from Bert Driehuis
+		 */
+		if( DEBUGLVL( 3 ) ) {
+			dbgtext( "wins_process_name_refresh_request: " );
+			dbgtext( "Name refresh for name %s, ",
+				 nmb_namestr(question) );
+			dbgtext( "but IP address %s ", inet_ntoa(from_ip) );
+			dbgtext( "is not yet associated with " );
+			dbgtext( "that name. Treating as registration.\n" );
+		}
+		wins_process_name_registration_request(subrec,p);
+		return;
 	} else if(group) {
 		/* 
-		 * Normal groups are all registered with an IP address of 255.255.255.255 
-		 * so we can't search for the IP address.
-	 	 */
+		 * Normal groups are all registered with an IP address of
+		 * 255.255.255.255  so we can't search for the IP address.
+		 */
 		update_name_ttl(namerec, ttl);
 		send_wins_name_registration_response(0, ttl, p);
 		return;
@@ -559,9 +596,12 @@ does not match group bit in WINS for this name.\n", nmb_namestr(question), group
 		/*
 		 * Fail the refresh.
 		 */
-
-		DEBUG(3,("wins_process_name_refresh_request: Name refresh for name %s with IP %s and \
-is IP is not known to the name.\n", nmb_namestr(question), inet_ntoa(from_ip) ));
+		if( DEBUGLVL( 3 ) ) {
+			dbgtext( "wins_process_name_refresh_request: " );
+			dbgtext( "Name refresh for name %s with IP %s ",
+				 nmb_namestr(question), inet_ntoa(from_ip) );
+			dbgtext( "and is IP is not known to the name.\n" );
+		}
 		send_wins_name_registration_response(RFS_ERR, 0, p);
 		return;
 	}