Restrict IMCs and IMVs to call SendMessage()

4 files changed, 47 insertions, 6 deletions

diff --git a/src/libcharon/plugins/tnccs_11/tnccs_11.c b/src/libcharon/plugins/tnccs_11/tnccs_11.c
index 033b73253..cd8cd3a43 100644
--- a/src/libcharon/plugins/tnccs_11/tnccs_11.c
+++ b/src/libcharon/plugins/tnccs_11/tnccs_11.c
@@ -77,6 +77,11 @@ struct private_tnccs_11_t {
 	bool delete_state;
 
 	/**
+	 * SendMessage() by IMC/IMV only allowed if flag is set
+	 */
+	bool send_msg;
+
+	/**
 	 * Flag set by IMC/IMV RequestHandshakeRetry() function
 	 */
 	bool request_handshake_retry;
@@ -87,7 +92,7 @@ struct private_tnccs_11_t {
 	recommendations_t *recs;
 };
 
-METHOD(tnccs_t, send_msg, void,
+METHOD(tnccs_t, send_msg, TNC_Result,
 	private_tnccs_11_t* this, TNC_IMCID imc_id, TNC_IMVID imv_id,
 							  TNC_BufferReference msg,
 							  TNC_UInt32 msg_len,
@@ -95,6 +100,13 @@ METHOD(tnccs_t, send_msg, void,
 {
 	tnccs_msg_t *tnccs_msg;
 
+	if (!this->send_msg)
+	{
+		DBG1(DBG_TNC, "%s %u not allowed to call SendMessage()",
+			this->is_server ? "IMV" : "IMC",
+			this->is_server ? imv_id : imc_id);
+		return TNC_RESULT_ILLEGAL_OPERATION;
+	}
 	tnccs_msg = imc_imv_msg_create(msg_type, chunk_create(msg, msg_len));
 
 	/* adding an IMC-IMV Message to TNCCS batch */
@@ -105,6 +117,7 @@ METHOD(tnccs_t, send_msg, void,
 	}
 	this->batch->add_msg(this->batch, tnccs_msg);
 	this->mutex->unlock(this->mutex);
+	return TNC_RESULT_SUCCESS;
 }
 
 /**
@@ -126,6 +139,7 @@ static void handle_message(private_tnccs_11_t *this, tnccs_msg_t *msg)
 
 			DBG2(DBG_TNC, "handling IMC_IMV message type 0x%08x", msg_type);
 
+			this->send_msg = TRUE;
 			if (this->is_server)
 			{
 				charon->imvs->receive_message(charon->imvs,
@@ -136,6 +150,7 @@ static void handle_message(private_tnccs_11_t *this, tnccs_msg_t *msg)
 				charon->imcs->receive_message(charon->imcs,
 				this->connection_id, msg_body.ptr, msg_body.len,msg_type);
 			}
+			this->send_msg = FALSE;
 			break;
 		}
 		case TNCCS_MSG_RECOMMENDATION:
@@ -286,6 +301,7 @@ METHOD(tls_t, process, status_t,
 			return FAILED;
 		}
 
+		this->send_msg = TRUE;
 		if (this->is_server)
 		{
 			charon->imvs->batch_ending(charon->imvs, this->connection_id);
@@ -294,6 +310,7 @@ METHOD(tls_t, process, status_t,
 		{
 			charon->imcs->batch_ending(charon->imcs, this->connection_id);
 		}
+		this->send_msg = FALSE;
 	}
 	batch->destroy(batch);
 
@@ -371,7 +388,9 @@ METHOD(tls_t, build, status_t,
 							this->connection_id, TNC_CONNECTION_STATE_CREATE);
 		charon->imcs->notify_connection_change(charon->imcs,
 							this->connection_id, TNC_CONNECTION_STATE_HANDSHAKE);
+		this->send_msg = TRUE;
 		charon->imcs->begin_handshake(charon->imcs, this->connection_id);
+		this->send_msg = FALSE;
 	}
 
 	/* Do not allow any asynchronous IMCs or IMVs to add additional messages */
diff --git a/src/libcharon/plugins/tnccs_20/tnccs_20.c b/src/libcharon/plugins/tnccs_20/tnccs_20.c
index 636f52569..9e2081d46 100644
--- a/src/libcharon/plugins/tnccs_20/tnccs_20.c
+++ b/src/libcharon/plugins/tnccs_20/tnccs_20.c
@@ -81,12 +81,17 @@ struct private_tnccs_20_t {
 	bool request_handshake_retry;
 
 	/**
+	  * SendMessage() by IMC/IMV only allowed if flag is set
+	  */
+	bool send_msg;
+
+	/**
 	 * Set of IMV recommendations  (TNC Server only)
 	 */
 	recommendations_t *recs;
 };
 
-METHOD(tnccs_t, send_msg, void,
+METHOD(tnccs_t, send_msg, TNC_Result,
 	private_tnccs_20_t* this, TNC_IMCID imc_id, TNC_IMVID imv_id,
 							  TNC_BufferReference msg,
 							  TNC_UInt32 msg_len,
@@ -97,6 +102,14 @@ METHOD(tnccs_t, send_msg, void,
 	pb_tnc_msg_t *pb_tnc_msg;
 	pb_tnc_batch_type_t batch_type;
 
+	if (!this->send_msg)
+	{
+		DBG1(DBG_TNC, "%s %u not allowed to call SendMessage()",
+			this->is_server ? "IMV" : "IMC",
+			this->is_server ? imv_id : imc_id);
+		return TNC_RESULT_ILLEGAL_OPERATION;
+	}
+
 	msg_sub_type =   msg_type       & TNC_SUBTYPE_ANY;
 	msg_vendor_id = (msg_type >> 8) & TNC_VENDORID_ANY;
 
@@ -119,6 +132,7 @@ METHOD(tnccs_t, send_msg, void,
 		pb_tnc_msg->destroy(pb_tnc_msg);
 	}
 	this->mutex->unlock(this->mutex);
+	return TNC_RESULT_SUCCESS;
 }
 
 /**
@@ -145,6 +159,7 @@ static void handle_message(private_tnccs_20_t *this, pb_tnc_msg_t *msg)
 
 			DBG2(DBG_TNC, "handling PB-PA message type 0x%08x", msg_type);
 
+			this->send_msg = TRUE;
 			if (this->is_server)
 			{
 				charon->imvs->receive_message(charon->imvs,
@@ -155,6 +170,7 @@ static void handle_message(private_tnccs_20_t *this, pb_tnc_msg_t *msg)
 				charon->imcs->receive_message(charon->imcs,
 				this->connection_id, msg_body.ptr, msg_body.len,msg_type);
 			}
+			this->send_msg = FALSE;
 			break;
 		}
 		case PB_MSG_ASSESSMENT_RESULT:
@@ -358,7 +374,9 @@ METHOD(tls_t, process, status_t,
 			/* Restart the measurements */
 			charon->imcs->notify_connection_change(charon->imcs,
 			this->connection_id, TNC_CONNECTION_STATE_HANDSHAKE);
+			this->send_msg = TRUE;
 			charon->imcs->begin_handshake(charon->imcs, this->connection_id);
+			this->send_msg = FALSE;
 		}
 
 		enumerator = batch->create_msg_enumerator(batch);
@@ -385,6 +403,7 @@ METHOD(tls_t, process, status_t,
 			}
 		}
 
+		this->send_msg = TRUE;
 		if (this->is_server)
 		{
 			charon->imvs->batch_ending(charon->imvs, this->connection_id);
@@ -393,6 +412,7 @@ METHOD(tls_t, process, status_t,
 		{
 			charon->imcs->batch_ending(charon->imcs, this->connection_id);
 		}
+		this->send_msg = FALSE;
 	}
 
 	switch (status)
@@ -501,7 +521,9 @@ METHOD(tls_t, build, status_t,
 							this->connection_id, TNC_CONNECTION_STATE_CREATE);
 		charon->imcs->notify_connection_change(charon->imcs,
 							this->connection_id, TNC_CONNECTION_STATE_HANDSHAKE);
+		this->send_msg = TRUE;
 		charon->imcs->begin_handshake(charon->imcs, this->connection_id);
+		this->send_msg = FALSE;
 	}
 
 	state = this->state_machine->get_state(this->state_machine);
diff --git a/src/libcharon/tnc/tnccs/tnccs.h b/src/libcharon/tnc/tnccs/tnccs.h
index c5d6f5ef0..32f065f67 100644
--- a/src/libcharon/tnc/tnccs/tnccs.h
+++ b/src/libcharon/tnc/tnccs/tnccs.h
@@ -72,8 +72,9 @@ typedef tnccs_t* (*tnccs_constructor_t)(bool is_server);
  * @param msg			message to be added
  * @param msg_len		message length
  * @param msg_type		message type
+ * @return			result code
  */
-typedef void (*tnccs_send_message_t)(tnccs_t* tncss, TNC_IMCID imc_id,
+typedef TNC_Result (*tnccs_send_message_t)(tnccs_t* tncss, TNC_IMCID imc_id,
 													 TNC_IMVID imv_id,
 									 				 TNC_BufferReference msg,
 													 TNC_UInt32 msg_len,
diff --git a/src/libcharon/tnc/tnccs/tnccs_manager.c b/src/libcharon/tnc/tnccs/tnccs_manager.c
index 2e3852b12..609742dc8 100644
--- a/src/libcharon/tnc/tnccs/tnccs_manager.c
+++ b/src/libcharon/tnc/tnccs/tnccs_manager.c
@@ -330,9 +330,8 @@ METHOD(tnccs_manager_t, send_message, TNC_Result,
 
 	if (tnccs && send_message)
 	{
-		send_message(tnccs, imc_id, imv_id, msg, msg_len, msg_type);
-		return TNC_RESULT_SUCCESS;
-	 }
+		return send_message(tnccs, imc_id, imv_id, msg, msg_len, msg_type);
+	}
 	return TNC_RESULT_FATAL;
 }