s4:netlogon/LogonGetDomainInfo - handle a NULL "dns_hostname"

- Performs the short computer name check against the sam account name.
- Enhances the LogonGetDomainInfo testsuite which checks the NULL
  "dns_hostname" behaviour

Autobuild-User: Matthias Dieter Wallnöfer <mdw@samba.org>
Autobuild-Date: Fri Nov 19 12:50:33 CET 2010 on sn-devel-104

2 files changed, 57 insertions, 27 deletions

diff --git a/source4/rpc_server/netlogon/dcerpc_netlogon.c b/source4/rpc_server/netlogon/dcerpc_netlogon.c
index 79d2cbc151..ea4ea23a50 100644
--- a/source4/rpc_server/netlogon/dcerpc_netlogon.c
+++ b/source4/rpc_server/netlogon/dcerpc_netlogon.c
@@ -5,7 +5,7 @@
 
    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2008
    Copyright (C) Stefan Metzmacher <metze@samba.org>  2005
-   Copyright (C) Matthias Dieter Wallnöfer            2009
+   Copyright (C) Matthias Dieter Wallnöfer            2009-2010
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1296,10 +1296,9 @@ static NTSTATUS dcesrv_netr_LogonGetDomainInfo(struct dcesrv_call_state *dce_cal
 	struct netlogon_creds_CredentialState *creds;
 	const char * const attrs[] = { "objectSid", "objectGUID", "flatName",
 		"securityIdentifier", "trustPartner", NULL };
-	const char * const attrs2[] = { "dNSHostName",
+	const char * const attrs2[] = { "sAMAccountName", "dNSHostName",
 		"msDS-SupportedEncryptionTypes", NULL };
-	const char *temp_str, *temp_str2;
-	const char *old_dns_hostname;
+	const char *sam_account_name, *old_dns_hostname, *prefix1, *prefix2;
 	struct ldb_context *sam_ctx;
 	struct ldb_message **res1, **res2, **res3, *new_msg;
 	struct ldb_dn *workstation_dn;
@@ -1336,35 +1335,48 @@ static NTSTATUS dcesrv_netr_LogonGetDomainInfo(struct dcesrv_call_state *dce_cal
 			return NT_STATUS_INVALID_PARAMETER;
 		}
 
-		/*
-		 * Checks that the computer name parameter without possible "$"
-		 * matches as prefix with the DNS hostname in the workstation
-		 * info structure.
-		 */
-		temp_str = talloc_strndup(mem_ctx,
-					  r->in.computer_name,
-					  strcspn(r->in.computer_name, "$"));
-		NT_STATUS_HAVE_NO_MEMORY(temp_str);
-		temp_str2 = talloc_strndup(mem_ctx,
-					   r->in.query->workstation_info->dns_hostname,
-					   strcspn(r->in.query->workstation_info->dns_hostname, "."));
-		NT_STATUS_HAVE_NO_MEMORY(temp_str2);
-		if (strcasecmp(temp_str, temp_str2) != 0) {
-			update_dns_hostname = false;
-		}
-
-		/* Prepare the workstation DN */
+		/* Prepares the workstation DN */
 		workstation_dn = ldb_dn_new_fmt(mem_ctx, sam_ctx, "<SID=%s>",
-			dom_sid_string(mem_ctx, creds->sid));
+						dom_sid_string(mem_ctx, creds->sid));
 		NT_STATUS_HAVE_NO_MEMORY(workstation_dn);
 
 		/* Lookup for attributes in workstation object */
-		ret = gendb_search_dn(sam_ctx, mem_ctx, workstation_dn,
-			&res1, attrs2);
+		ret = gendb_search_dn(sam_ctx, mem_ctx, workstation_dn, &res1,
+				      attrs2);
 		if (ret != 1) {
 			return NT_STATUS_INTERNAL_DB_CORRUPTION;
 		}
 
+		/* Gets the sam account name which is checked against the DNS
+		 * hostname parameter. */
+		sam_account_name = ldb_msg_find_attr_as_string(res1[0],
+							       "sAMAccountName",
+							       NULL);
+		if (sam_account_name == NULL) {
+			return NT_STATUS_INTERNAL_DB_CORRUPTION;
+		}
+
+		/*
+		 * Checks that the sam account name without a possible "$"
+		 * matches as prefix with the DNS hostname in the workstation
+		 * info structure.
+		 */
+		prefix1 = talloc_strndup(mem_ctx, sam_account_name,
+					 strcspn(sam_account_name, "$"));
+		NT_STATUS_HAVE_NO_MEMORY(prefix1);
+		if (r->in.query->workstation_info->dns_hostname != NULL) {
+			prefix2 = talloc_strndup(mem_ctx,
+						 r->in.query->workstation_info->dns_hostname,
+						 strcspn(r->in.query->workstation_info->dns_hostname, "."));
+			NT_STATUS_HAVE_NO_MEMORY(prefix2);
+
+			if (strcasecmp(prefix1, prefix2) != 0) {
+				update_dns_hostname = false;
+			}
+		} else {
+			update_dns_hostname = false;
+		}
+
 		/* Gets the old DNS hostname */
 		old_dns_hostname = ldb_msg_find_attr_as_string(res1[0],
 							       "dNSHostName",
diff --git a/source4/torture/rpc/netlogon.c b/source4/torture/rpc/netlogon.c
index 9758185046..b1739a015c 100644
--- a/source4/torture/rpc/netlogon.c
+++ b/source4/torture/rpc/netlogon.c
@@ -3203,6 +3203,7 @@ static bool test_GetDomainInfo(struct torture_context *tctx,
 		info.domain_info->dns_hostname.string,
 		query.workstation_info->dns_hostname,
 		"In/Out 'DNS hostnames' don't match!");
+	old_dnsname = info.domain_info->dns_hostname.string;
 
 	/* Checks "workstation flags" */
 	torture_assert(tctx,
@@ -3246,12 +3247,29 @@ static bool test_GetDomainInfo(struct torture_context *tctx,
 		"Trusted domains have been requested!");
 
 
+	torture_comment(tctx, "Testing netr_LogonGetDomainInfo 6th call (no DNS hostname)\n");
+	netlogon_creds_client_authenticator(creds, &a);
+
+	query.workstation_info->dns_hostname = NULL;
+
+	torture_assert_ntstatus_ok(tctx, dcerpc_netr_LogonGetDomainInfo_r(b, tctx, &r),
+		"LogonGetDomainInfo failed");
+	torture_assert_ntstatus_ok(tctx, r.out.result, "LogonGetDomainInfo failed");
+	torture_assert(tctx, netlogon_creds_client_check(creds, &a.cred), "Credential chaining failed");
+
+	/* The old DNS hostname should stick */
+	torture_assert_str_equal(tctx,
+		info.domain_info->dns_hostname.string,
+		old_dnsname,
+		"'DNS hostname' changed!");
+
+
 	if (!torture_setting_bool(tctx, "dangerous", false)) {
-		torture_comment(tctx, "Not testing netr_LogonGetDomainInfo 6th call (no workstation info) - enable dangerous tests in order to do so\n");
+		torture_comment(tctx, "Not testing netr_LogonGetDomainInfo 7th call (no workstation info) - enable dangerous tests in order to do so\n");
 	} else {
 		/* Try a call without the workstation information structure */
 
-		torture_comment(tctx, "Testing netr_LogonGetDomainInfo 6th call (no workstation info)\n");
+		torture_comment(tctx, "Testing netr_LogonGetDomainInfo 7th call (no workstation info)\n");
 		netlogon_creds_client_authenticator(creds, &a);
 
 		query.workstation_info = NULL;