r12606: - fix multihomed registrations

  always remove the addresses which are no longer valid
- use the wins_challenge_send/recv calls which are also used by the replication
  challenge

metze
(This used to be commit 037b5d9f3661fd7a121d1db0a50dc7743d62a5e1)

1 files changed, 224 insertions, 2 deletions

diff --git a/source4/nbt_server/wins/winsserver.c b/source4/nbt_server/wins/winsserver.c
index 02b2048f73..a456ed06d5 100644
--- a/source4/nbt_server/wins/winsserver.c
+++ b/source4/nbt_server/wins/winsserver.c
@@ -24,7 +24,9 @@
 #include "includes.h"
 #include "nbt_server/nbt_server.h"
 #include "nbt_server/wins/winsdb.h"
+#include "nbt_server/wins/winswack.h"
 #include "system/time.h"
+#include "libcli/composite/composite.h"
 #include "smbd/service_task.h"
 
 /*
@@ -163,6 +165,226 @@ static uint8_t wins_sgroup_merge(struct nbt_name_socket *nbtsock,
 	return winsdb_modify(winssrv->wins_db, rec, WINSDB_FLAG_ALLOC_VERSION | WINSDB_FLAG_TAKE_OWNERSHIP);
 }
 
+struct wack_state {
+	struct wins_server *winssrv;
+	struct nbt_name_socket *nbtsock;
+	struct nbt_name_packet *request_packet;
+	struct winsdb_record *rec;
+	struct nbt_peer_socket src;
+	const char *reg_address;
+	enum wrepl_name_type new_type;
+	struct wins_challenge_io io;
+	NTSTATUS status;
+};
+
+/*
+  deny a registration request
+*/
+static void wins_wack_deny(struct wack_state *s)
+{
+	nbtd_name_registration_reply(s->nbtsock, s->request_packet, 
+				     &s->src, NBT_RCODE_ACT);
+	DEBUG(4,("WINS: denied name registration request for %s from %s:%d\n",
+		 nbt_name_string(s, s->rec->name), s->src.addr, s->src.port));
+	talloc_free(s);
+}
+
+/*
+  allow a registration request
+*/
+static void wins_wack_allow(struct wack_state *s)
+{
+	NTSTATUS status;
+	uint32_t ttl = wins_server_ttl(s->winssrv, s->request_packet->additional[0].ttl);
+	struct winsdb_record *rec = s->rec, *rec2;
+	uint32_t i,j;
+
+	status = winsdb_lookup(s->winssrv->wins_db, rec->name, s, &rec2);
+	if (!NT_STATUS_IS_OK(status) ||
+	    rec2->version != rec->version ||
+	    strcmp(rec2->wins_owner, rec->wins_owner) != 0) {
+		DEBUG(1,("WINS: record %s changed during WACK - failing registration\n",
+			 nbt_name_string(s, rec->name)));
+		wins_wack_deny(s);
+		return;
+	}
+
+	/*
+	 * if the old name owner doesn't hold the name anymore
+	 * handle the request as new registration for the new name owner
+	 */
+	if (!NT_STATUS_IS_OK(s->status)) {
+		uint8_t rcode;
+
+		winsdb_delete(s->winssrv->wins_db, rec);
+		rcode = wins_register_new(s->nbtsock, s->request_packet, &s->src, s->new_type);
+		if (rcode != NBT_RCODE_OK) {
+			DEBUG(1,("WINS: record %s failed to register as new during WACK\n",
+				 nbt_name_string(s, rec->name)));
+			wins_wack_deny(s);
+			return;
+		}
+		goto done;
+	}
+
+	rec->expire_time = time(NULL) + ttl;
+	rec->registered_by = s->src.addr;
+
+	/*
+	 * now remove all addresses that're the client doesn't hold anymore
+	 * and update the time stamp and owner for the ownes that are still there
+	 */
+	for (i=0; rec->addresses[i]; i++) {
+		BOOL found = False;
+		for (j=0; j < s->io.out.num_addresses; j++) {
+			if (strcmp(rec->addresses[i]->address, s->io.out.addresses[j]) != 0) continue;
+
+			found = True;
+			break;
+		}
+		if (found) {
+			rec->addresses[i]->wins_owner = WINSDB_OWNER_LOCAL;
+			rec->addresses[i]->expire_time = rec->expire_time;
+			continue;
+		}
+
+		winsdb_addr_list_remove(rec->addresses, rec->addresses[i]->address);
+	}
+
+	rec->addresses = winsdb_addr_list_add(rec->addresses,
+					      s->reg_address,
+					      WINSDB_OWNER_LOCAL,
+					      rec->expire_time);
+	if (rec->addresses == NULL) goto failed;
+
+	/* if we have more than one address, this becomes implicit a MHOMED record */
+	if (winsdb_addr_list_length(rec->addresses) > 1) {
+		rec->type = WREPL_TYPE_MHOMED;
+	}
+
+	winsdb_modify(s->winssrv->wins_db, rec, WINSDB_FLAG_ALLOC_VERSION | WINSDB_FLAG_TAKE_OWNERSHIP);
+
+	DEBUG(4,("WINS: accepted registration of %s with address %s\n",
+		 nbt_name_string(s, rec->name), s->reg_address));
+
+done:
+	nbtd_name_registration_reply(s->nbtsock, s->request_packet, 
+				     &s->src, NBT_RCODE_OK);
+failed:
+	talloc_free(s);
+}
+
+/*
+  called when a name query to a current owner completes
+*/
+static void wack_wins_challenge_handler(struct composite_context *c_req)
+{
+	struct wack_state *s = talloc_get_type(c_req->async.private_data,
+					       struct wack_state);
+	BOOL found;
+	uint32_t i;
+
+	s->status = wins_challenge_recv(c_req, s, &s->io);
+
+	/*
+	 * if the owner denies it holds the name, then allow
+	 * the registration
+	 */
+	if (!NT_STATUS_IS_OK(s->status)) {
+		wins_wack_allow(s);
+		return;
+	}
+
+	if (s->new_type == WREPL_TYPE_GROUP || s->new_type == WREPL_TYPE_SGROUP) {
+		DEBUG(1,("WINS: record %s failed to register as group type(%u) during WACK, it's still type(%u)\n",
+			 nbt_name_string(s, s->rec->name), s->new_type, s->rec->type));
+		wins_wack_deny(s);
+		return;
+	}
+
+	/*
+	 * if the owner still wants the name and doesn't reply
+	 * with the address trying to be registered, then deny
+	 * the registration
+	 */
+	found = False;
+	for (i=0; i < s->io.out.num_addresses; i++) {
+		if (strcmp(s->reg_address, s->io.out.addresses[i]) != 0) continue;
+
+		found = True;
+		break;
+	}
+	if (!found) {
+		wins_wack_deny(s);
+		return;
+	}
+
+	wins_wack_allow(s);
+	return;
+}
+
+
+/*
+  a client has asked to register a unique name that someone else owns. We
+  need to ask each of the current owners if they still want it. If they do
+  then reject the registration, otherwise allow it
+*/
+static void wins_register_wack(struct nbt_name_socket *nbtsock, 
+			       struct nbt_name_packet *packet, 
+			       struct winsdb_record *rec,
+			       const struct nbt_peer_socket *src,
+			       enum wrepl_name_type new_type)
+{
+	struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, 
+						       struct nbtd_interface);
+	struct wins_server *winssrv = iface->nbtsrv->winssrv;
+	struct wack_state *s;
+	struct composite_context *c_req;
+	uint32_t ttl;
+
+	s = talloc_zero(nbtsock, struct wack_state);
+	if (s == NULL) goto failed;
+
+	/* package up the state variables for this wack request */
+	s->winssrv		= winssrv;
+	s->nbtsock		= nbtsock;
+	s->request_packet	= talloc_steal(s, packet);
+	s->rec			= talloc_steal(s, rec);
+	s->reg_address		= packet->additional[0].rdata.netbios.addresses[0].ipaddr;
+	s->new_type		= new_type;
+	s->src.port		= src->port;
+	s->src.addr		= talloc_strdup(s, src->addr);
+	if (s->src.addr == NULL) goto failed;
+
+	s->io.in.nbtd_server	= iface->nbtsrv;
+	s->io.in.event_ctx	= iface->nbtsrv->task->event_ctx;
+	s->io.in.name		= rec->name;
+	s->io.in.num_addresses	= winsdb_addr_list_length(rec->addresses);
+	s->io.in.addresses	= winsdb_addr_string_list(s, rec->addresses);
+	if (s->io.in.addresses == NULL) goto failed;
+
+	/*
+	 * send a WACK to the client, specifying the maximum time it could
+         * take to check with the owner, plus some slack
+	 */
+	ttl = 5 + 4 * winsdb_addr_list_length(rec->addresses);
+	nbtd_wack_reply(nbtsock, packet, src, ttl);
+
+	/*
+	 * send the challenge to the old addresses
+	 */
+	c_req = wins_challenge_send(s, &s->io);
+	if (c_req == NULL) goto failed;
+
+	c_req->async.fn			= wack_wins_challenge_handler;
+	c_req->async.private_data	= s;
+	return;
+
+failed:
+	talloc_free(s);
+	nbtd_name_registration_reply(nbtsock, packet, src, NBT_RCODE_SVR);
+}
+
 /*
   register a name
 */
@@ -263,7 +485,7 @@ static void nbtd_winsserver_register(struct nbt_name_socket *nbtsock,
 		 * TODO: is this correct?
 		 */
 		if (new_type == WREPL_TYPE_GROUP || new_type == WREPL_TYPE_GROUP) {
-			wins_register_wack(nbtsock, packet, rec, src);
+			wins_register_wack(nbtsock, packet, rec, src, new_type);
 			return;
 		}
 
@@ -282,7 +504,7 @@ static void nbtd_winsserver_register(struct nbt_name_socket *nbtsock,
 		 * we have to do a WACK to see if the current owner is willing
 		 * to give up its claim
 		 */
-		wins_register_wack(nbtsock, packet, rec, src);
+		wins_register_wack(nbtsock, packet, rec, src, new_type);
 		return;
 
 	case WREPL_TYPE_GROUP: