r26192: Handle, test and implement the style of extended_dn requiest that MMC uses.

It appears that the control value is optional, implying type 0 responses.

Failing to parse this was causing LDAP disconnects with 'unavailable
critical extension'.

Andrew Bartlett
(This used to be commit 833dfc2f2af84c45f954e428c9ea6babf100ba92)

4 files changed, 45 insertions, 3 deletions

diff --git a/source4/libcli/ldap/ldap.c b/source4/libcli/ldap/ldap.c
index 11689fbd79..34d715e3e5 100644
--- a/source4/libcli/ldap/ldap.c
+++ b/source4/libcli/ldap/ldap.c
@@ -1325,10 +1325,12 @@ NTSTATUS ldap_decode(struct asn1_data *data, struct ldap_message *msg)
 	}
 
 	msg->controls = NULL;
+	msg->controls_decoded = NULL;
 
 	if (asn1_peek_tag(data, ASN1_CONTEXT(0))) {
 		int i = 0;
 		struct ldb_control **ctrl = NULL;
+		bool *decoded = NULL;
 
 		asn1_start_tag(data, ASN1_CONTEXT(0));
 
@@ -1341,6 +1343,11 @@ NTSTATUS ldap_decode(struct asn1_data *data, struct ldap_message *msg)
 				return NT_STATUS_LDAP(LDAP_OPERATIONS_ERROR);
 			}
 
+			decoded = talloc_realloc(msg, decoded, bool, i+1);
+			if (!decoded) {
+				return NT_STATUS_LDAP(LDAP_OPERATIONS_ERROR);
+			}
+
 			ctrl[i] = talloc(ctrl, struct ldb_control);
 			if (!ctrl[i]) {
 				return NT_STATUS_LDAP(LDAP_OPERATIONS_ERROR);
@@ -1352,12 +1359,15 @@ NTSTATUS ldap_decode(struct asn1_data *data, struct ldap_message *msg)
 			
 			if (!ldap_decode_control_value(ctrl, value, ctrl[i])) {
 				if (ctrl[i]->critical) {
-					return NT_STATUS_LDAP(LDAP_UNAVAILABLE_CRITICAL_EXTENSION);
+					ctrl[i]->data = NULL;
+					decoded[i] = false;
+					i++;
 				} else {
 					talloc_free(ctrl[i]);
 					ctrl[i] = NULL;
 				}
 			} else {
+				decoded[i] = true;
 				i++;
 			}
 		}
@@ -1367,6 +1377,7 @@ NTSTATUS ldap_decode(struct asn1_data *data, struct ldap_message *msg)
 		}
 
 		msg->controls = ctrl;
+		msg->controls_decoded = decoded;
 
 		asn1_end_tag(data);
 	}
diff --git a/source4/libcli/ldap/ldap.h b/source4/libcli/ldap/ldap.h
index e89322213a..6f5e86744e 100644
--- a/source4/libcli/ldap/ldap.h
+++ b/source4/libcli/ldap/ldap.h
@@ -240,11 +240,13 @@ union ldap_Request {
 	struct ldap_ExtendedResponse 	ExtendedResponse;
 };
 
+
 struct ldap_message {
 	int                     messageid;
 	enum ldap_request_tag   type;
 	union ldap_Request      r;
 	struct ldb_control    **controls;
+	bool                   *controls_decoded;
 };
 
 struct event_context;
diff --git a/source4/libcli/ldap/ldap_client.c b/source4/libcli/ldap/ldap_client.c
index fcb2d92214..41e9c37196 100644
--- a/source4/libcli/ldap/ldap_client.c
+++ b/source4/libcli/ldap/ldap_client.c
@@ -116,6 +116,7 @@ static void ldap_error_handler(void *private_data, NTSTATUS status)
 static void ldap_match_message(struct ldap_connection *conn, struct ldap_message *msg)
 {
 	struct ldap_request *req;
+	int i;
 
 	for (req=conn->pending; req; req=req->next) {
 		if (req->messageid == msg->messageid) break;
@@ -132,6 +133,20 @@ static void ldap_match_message(struct ldap_connection *conn, struct ldap_message
 		return;
 	}
 
+	/* Check for undecoded critical extensions */
+	for (i=0; msg->controls && msg->controls[i]; i++) {
+		if (!msg->controls_decoded[i] && 
+		    msg->controls[i]->critical) {
+			req->status = NT_STATUS_LDAP(LDAP_UNAVAILABLE_CRITICAL_EXTENSION);
+			req->state = LDAP_REQUEST_DONE;
+			DLIST_REMOVE(conn->pending, req);
+			if (req->async.fn) {
+				req->async.fn(req);
+			}
+			return;
+		}
+	}
+
 	/* add to the list of replies received */
 	talloc_steal(req, msg);
 	req->replies = talloc_realloc(req, req->replies, 
diff --git a/source4/libcli/ldap/ldap_controls.c b/source4/libcli/ldap/ldap_controls.c
index b7fd1ce178..34e5cccf75 100644
--- a/source4/libcli/ldap/ldap_controls.c
+++ b/source4/libcli/ldap/ldap_controls.c
@@ -156,9 +156,16 @@ static bool decode_server_sort_request(void *mem_ctx, DATA_BLOB in, void **out)
 
 static bool decode_extended_dn_request(void *mem_ctx, DATA_BLOB in, void **out)
 {
-	struct asn1_data *data = asn1_init(mem_ctx);
+	struct asn1_data *data;
 	struct ldb_extended_dn_control *ledc;
 
+	/* The content of this control is optional */
+	if (in.length == 0) {
+		*out = NULL;
+		return true;
+	}
+
+	data = asn1_init(mem_ctx);
 	if (!data) return false;
 
 	if (!asn1_load(data, in)) {
@@ -717,7 +724,14 @@ static bool encode_server_sort_request(void *mem_ctx, void *in, DATA_BLOB *out)
 static bool encode_extended_dn_request(void *mem_ctx, void *in, DATA_BLOB *out)
 {
 	struct ldb_extended_dn_control *ledc = talloc_get_type(in, struct ldb_extended_dn_control);
-	struct asn1_data *data = asn1_init(mem_ctx);
+	struct asn1_data *data;
+
+	if (!in) {
+		*out = data_blob(NULL, 0);
+		return true;
+	}
+
+	data = asn1_init(mem_ctx);
 
 	if (!data) return false;