s4-dsdb: added samdb_ntds_msdcs_dns_name()

this gets the DNS name for a NTDS GUID, based on the forest DNS name

Pair-Programmed-With: Amitay Isaacs <amitay@gmail.com>

diff --git a/source4/dsdb/common/util.c b/source4/dsdb/common/util.c
index cf2e766f010b779fad334e1316bf6e2ea6962456..f64e624dfda515f94fffb034e8c151be0d58b209 100644 (file)
--- a/source4/dsdb/common/util.c
+++ b/source4/dsdb/common/util.c
@@ -2367,13 +2367,14 @@ char *samdb_dn_to_dns_domain(TALLOC_CTX *mem_ctx, struct ldb_dn *dn)
        }
 
        for (i=0; i<num_components; i++) {
-               struct ldb_val *v = ldb_dn_get_component_val(dn, i);
+               const struct ldb_val *v = ldb_dn_get_component_val(dn, i);
                char *s;
                if (v == NULL) {
                        talloc_free(dns_name);
                        return NULL;
                }
-               s = talloc_asprintf_append_buffer(dns_name, "%*.*s.", v->length, v->length, (char *)v->data);
+               s = talloc_asprintf_append_buffer(dns_name, "%*.*s.",
+                                                 (int)v->length, (int)v->length, (char *)v->data);
                if (s == NULL) {
                        talloc_free(dns_name);
                        return NULL;
@@ -2389,6 +2390,40 @@ char *samdb_dn_to_dns_domain(TALLOC_CTX *mem_ctx, struct ldb_dn *dn)
        return dns_name;
 }
 
+/*
+  Find the DNS _msdcs name for a given NTDS GUID. The resulting DNS
+  name is based on the forest DNS name
+*/
+char *samdb_ntds_msdcs_dns_name(struct ldb_context *samdb,
+                               TALLOC_CTX *mem_ctx,
+                               const struct GUID *ntds_guid)
+{
+       TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+       const char *guid_str;
+       struct ldb_dn *forest_dn;
+       const char *dnsforest;
+       char *ret;
+
+       guid_str = GUID_string(tmp_ctx, ntds_guid);
+       if (guid_str == NULL) {
+               talloc_free(tmp_ctx);
+               return NULL;
+       }
+       forest_dn = ldb_get_root_basedn(samdb);
+       if (forest_dn == NULL) {
+               talloc_free(tmp_ctx);
+               return NULL;
+       }
+       dnsforest = samdb_dn_to_dns_domain(tmp_ctx, forest_dn);
+       if (dnsforest == NULL) {
+               talloc_free(tmp_ctx);
+               return NULL;
+       }
+       ret = talloc_asprintf(mem_ctx, "%s._msdcs.%s", guid_str, dnsforest);
+       talloc_free(tmp_ctx);
+       return ret;
+}
+
 
 /*
   Find the DN of a domain, be it the netbios or DNS name