dsdb: Add a samdb_dns_host_name which avoids searching

This ideally should also be used in rootDSE.

Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/dsdb/common/util.c b/source4/dsdb/common/util.c
index b46a7fc4054078754db21a3e69fbfd1b731e18e2..7a12c71799bef0146c0906785d4e6d7a273146d7 100644 (file)
--- a/source4/dsdb/common/util.c
+++ b/source4/dsdb/common/util.c
@@ -3485,6 +3485,53 @@ int samdb_rodc(struct ldb_context *sam_ctx, bool *am_rodc)
        return LDB_SUCCESS;
 }
 
+int samdb_dns_host_name(struct ldb_context *sam_ctx, const char **host_name)
+{
+       const char *_host_name = NULL;
+       const char *attrs[] = { "dnsHostName", NULL };
+       TALLOC_CTX *tmp_ctx = NULL;
+       int ret;
+       struct ldb_result *res = NULL;
+
+       _host_name = (const char *)ldb_get_opaque(sam_ctx, "cache.dns_host_name");
+       if (_host_name != NULL) {
+               *host_name = _host_name;
+               return LDB_SUCCESS;
+       }
+
+       tmp_ctx = talloc_new(sam_ctx);
+
+       ret = dsdb_search_dn(sam_ctx, tmp_ctx, &res, NULL, attrs, 0);
+
+       if (res->count != 1 || ret != LDB_SUCCESS) {
+               DEBUG(0, ("Failed to get rootDSE for dnsHostName: %s",
+                         ldb_errstring(sam_ctx)));
+               TALLOC_FREE(tmp_ctx);
+               return ret;
+       }
+
+
+       _host_name = ldb_msg_find_attr_as_string(res->msgs[0],
+                                                "dnsHostName",
+                                                NULL);
+       if (_host_name == NULL) {
+               DEBUG(0, ("Failed to get dnsHostName from rootDSE"));
+               TALLOC_FREE(tmp_ctx);
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+       ret = ldb_set_opaque(sam_ctx, "cache.dns_host_name",
+                            discard_const_p(char *, _host_name));
+       if (ret != LDB_SUCCESS) {
+               TALLOC_FREE(tmp_ctx);
+               return ldb_operr(sam_ctx);
+       }
+
+       *host_name = talloc_steal(sam_ctx, _host_name);
+
+       TALLOC_FREE(tmp_ctx);
+       return LDB_SUCCESS;
+}
+
 bool samdb_set_am_rodc(struct ldb_context *ldb, bool am_rodc)
 {
        TALLOC_CTX *tmp_ctx;