r5418: - added version numbers to WINS database records in preparation for adding...

  replication support

- on a WACK registration success, check that the database record
  hasn't changed during the WACK processing. If it has, then fail
  the registration

diff --git a/source/nbt_server/winsdb.c b/source/nbt_server/winsdb.c
index 4eff12901fd026257934f36e4d20be0e8e0755f0..66e84c668b9182bd64d8f324ba7b1b1a8d2373ee 100644 (file)
--- a/source/nbt_server/winsdb.c
+++ b/source/nbt_server/winsdb.c
@@ -27,6 +27,62 @@
 #include "db_wrap.h"
 #include "system/time.h"
 
+/*
+  save the min/max version IDs for the database
+*/
+static BOOL winsdb_save_version(struct wins_server *winssrv)
+{
+       int i, ret = 0;
+       struct ldb_context *ldb = winssrv->wins_db->ldb;
+       struct ldb_message *msg = ldb_msg_new(winssrv);
+       if (msg == NULL) goto failed;
+
+       msg->dn = talloc_strdup(msg, "CN=VERSION");
+       if (msg->dn == NULL) goto failed;
+
+       ret |= ldb_msg_add_fmt(ldb, msg, "minVersion", "%llu", winssrv->min_version);
+       ret |= ldb_msg_add_fmt(ldb, msg, "maxVersion", "%llu", winssrv->max_version);
+       if (ret != 0) goto failed;
+
+       for (i=0;i<msg->num_elements;i++) {
+               msg->elements[i].flags = LDB_FLAG_MOD_REPLACE;
+       }
+
+       ret = ldb_modify(ldb, msg);
+       if (ret != 0) ret = ldb_add(ldb, msg);
+       if (ret != 0) goto failed;
+
+       talloc_free(msg);
+       return True;
+
+failed:
+       talloc_free(msg);
+       return False;
+}
+
+/*
+  allocate a new version id for a record
+*/
+static uint64_t winsdb_allocate_version(struct wins_server *winssrv)
+{
+       winssrv->max_version++;
+       if (!winsdb_save_version(winssrv)) {
+               return 0;
+       }
+       return winssrv->max_version;
+}
+
+/*
+  allocate a new version id for a record
+*/
+static void winsdb_remove_version(struct wins_server *winssrv, uint64_t version)
+{
+       if (version == winssrv->min_version) {
+               winssrv->min_version++;
+               winsdb_save_version(winssrv);
+       }
+}
+
 /*
   load a WINS entry from the database
 */
@@ -60,6 +116,7 @@ struct winsdb_record *winsdb_load(struct wins_server *winssrv,
        rec->nb_flags       = ldb_msg_find_int(res[0], "nbFlags", 0);
        rec->expire_time    = ldap_string_to_time(ldb_msg_find_string(res[0], "expires", NULL));
        rec->registered_by  = ldb_msg_find_string(res[0], "registeredBy", NULL);
+       rec->version        = ldb_msg_find_uint64(res[0], "version", 0);
        talloc_steal(rec, rec->registered_by);
 
        el = ldb_msg_find_element(res[0], "address");
@@ -109,6 +166,7 @@ static struct ldb_message *winsdb_message(struct wins_server *winssrv,
        ret |= ldb_msg_add_string(ldb, msg, "registeredBy", rec->registered_by);
        ret |= ldb_msg_add_string(ldb, msg, "expires", 
                                  ldap_timestring(msg, rec->expire_time));
+       ret |= ldb_msg_add_fmt(ldb, msg, "version", "%llu", rec->version);
        for (i=0;rec->addresses[i];i++) {
                ret |= ldb_msg_add_string(ldb, msg, "address", rec->addresses[i]);
        }
@@ -130,6 +188,9 @@ uint8_t winsdb_add(struct wins_server *winssrv, struct winsdb_record *rec)
        TALLOC_CTX *tmp_ctx = talloc_new(winssrv);
        int ret;
 
+       rec->version = winsdb_allocate_version(winssrv);
+       if (rec->version == 0) goto failed;
+
        msg = winsdb_message(winssrv, rec, tmp_ctx);
        if (msg == NULL) goto failed;
        ret = ldb_add(ldb, msg);
@@ -155,6 +216,9 @@ uint8_t winsdb_modify(struct wins_server *winssrv, struct winsdb_record *rec)
        int ret;
        int i;
 
+       rec->version = winsdb_allocate_version(winssrv);
+       if (rec->version == 0) goto failed;
+
        msg = winsdb_message(winssrv, rec, tmp_ctx);
        if (msg == NULL) goto failed;
 
@@ -177,14 +241,16 @@ failed:
 /*
   delete a WINS record from the database
 */
-uint8_t winsdb_delete(struct wins_server *winssrv, struct nbt_name *name)
+uint8_t winsdb_delete(struct wins_server *winssrv, struct winsdb_record *rec)
 {
        struct ldb_context *ldb = winssrv->wins_db->ldb;
        TALLOC_CTX *tmp_ctx = talloc_new(winssrv);
        int ret;
        const char *dn;
 
-       dn = talloc_asprintf(tmp_ctx, "NAME=%s", nbt_name_string(tmp_ctx, name));
+       winsdb_remove_version(winssrv, rec->version);
+
+       dn = talloc_asprintf(tmp_ctx, "NAME=%s", nbt_name_string(tmp_ctx, rec->name));
        if (dn == NULL) goto failed;
 
        ret = ldb_delete(ldb, dn);

diff --git a/source/nbt_server/winsdb.h b/source/nbt_server/winsdb.h
index 0774757ef99fbc03f911c469b52222bdf6356817..6d395461c6e44aa762231e8b1b17cba8049ae5b6 100644 (file)
--- a/source/nbt_server/winsdb.h
+++ b/source/nbt_server/winsdb.h
@@ -35,6 +35,7 @@ struct winsdb_record {
        time_t expire_time;
        const char *registered_by;
        const char **addresses;
+       uint64_t version;
 };
 
 struct wins_server {
@@ -43,4 +44,9 @@ struct wins_server {
 
        uint32_t min_ttl;
        uint32_t max_ttl;
+
+       /* these are the minimum and maximum record version IDs in the
+          database. They are needed for replication */
+       uint64_t min_version;
+       uint64_t max_version;
 };

diff --git a/source/nbt_server/winsserver.c b/source/nbt_server/winsserver.c
index c1eed0b1fa2cb596114e1fd1fd45078e0ac049d8..6d8770431ea0e36917d9b91c4d8faf3a8b7eac83 100644 (file)
--- a/source/nbt_server/winsserver.c
+++ b/source/nbt_server/winsserver.c
@@ -123,7 +123,7 @@ static void nbtd_winsserver_register(struct nbt_name_socket *nbtsock,
                rcode = wins_register_new(nbtsock, packet, src_address, src_port);
                goto done;
        } else if (rec->state != WINS_REC_ACTIVE) {
-               winsdb_delete(winssrv, rec->name);
+               winsdb_delete(winssrv, rec);
                rcode = wins_register_new(nbtsock, packet, src_address, src_port);
                goto done;
        }

diff --git a/source/nbt_server/winswack.c b/source/nbt_server/winswack.c
index 190b1cdec7ddca4f7a9e0bd1dd281c2ef86d09ae..da8efff8d943a77a00a7aa30e62bdc27c9a49918 100644 (file)
--- a/source/nbt_server/winswack.c
+++ b/source/nbt_server/winswack.c
@@ -57,7 +57,15 @@ static void wins_wack_allow(struct wack_state *state)
 {
        uint32_t ttl;
        time_t now = time(NULL);
-       struct winsdb_record *rec = state->rec;
+       struct winsdb_record *rec = state->rec, *rec2;
+
+       rec2 = winsdb_load(state->winssrv, rec->name, state);
+       if (rec2 == NULL || rec2->version != rec->version) {
+               DEBUG(1,("WINS: record %s changed during WACK - failing registration\n",
+                        nbt_name_string(state, rec->name)));
+               wins_wack_deny(state);
+               return;
+       }
 
        nbtd_name_registration_reply(state->nbtsock, state->request_packet, 
                                     state->src_address, state->src_port, NBT_RCODE_OK);