1 files changed, 131 insertions, 0 deletions
diff --git a/src/lib/protocols/websocket.c b/src/lib/protocols/websocket.c
new file mode 100644
index 000000000..fe4603aa0
--- /dev/null
+++ b/src/lib/protocols/websocket.c
@@ -0,0 +1,131 @@
+/*
+ * websocket.c
+ *
+ * Copyright (C) 2018 by Leonn Paiva <leonn.paiva@gmail.com>
+ *
+ * This file is part of nDPI, an open source deep packet inspection
+ * library based on the OpenDPI and PACE technology by ipoque GmbH
+ *
+ * nDPI is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * nDPI is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with nDPI.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ndpi_protocol_ids.h"
+
+#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_WEBSOCKET
+
+#include "ndpi_api.h"
+
+enum websocket_opcode
+{
+    /*
+    * CONTINUATION_FRAME is not relevant for the detection and leads to many false positives  
+    CONTINUATION_FRAME = 0x00,
+    FIN_CONTINUATION_FRAME = 0x80,
+     */
+    TEXT_FRAME = 0x01,
+    FIN_TEXT_FRAME = 0x81,
+    BINARY_FRAME = 0x02,
+    FIN_BINARY_FRAME = 0x82,
+    CONNECTION_CLOSE_FRAME = 0x08,
+    FIN_CONNECTION_CLOSE_FRAME = 0x88,
+    PING_FRAME = 0x09,
+    FIN_PING_FRAME = 0x89,
+    PONG_FRAME = 0x0A,
+    FIN_PONG_FRAME = 0x8A
+};
+
+static void set_websocket_detected(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+    /* If no custom protocol has been detected */
+    if (flow->detected_protocol_stack[0] == NDPI_PROTOCOL_UNKNOWN)
+    {
+        ndpi_search_tcp_or_udp(ndpi_struct, flow);
+
+        ndpi_int_reset_protocol(flow);
+        ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_WEBSOCKET, flow->guessed_host_protocol_id);
+    }
+}
+
+/*************************************************************************************************/
+
+static void ndpi_check_websocket(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+    struct ndpi_packet_struct *packet = &flow->packet;
+
+    if (packet->payload_packet_len < sizeof(u_int16_t))
+    {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return;
+    }
+
+    u_int8_t websocket_payload_length = packet->payload[1] & 0x7F;
+    u_int8_t websocket_masked = packet->payload[1] & 0x80;
+
+    uint8_t hdr_size = (websocket_masked == 1) ? 6 : 2;
+
+    if (packet->payload_packet_len != hdr_size + websocket_payload_length)
+    {
+        NDPI_LOG_DBG(ndpi_struct, "Invalid WEBSOCKET payload");
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return;
+    }
+
+    if (packet->payload[0] == TEXT_FRAME ||  packet->payload[0] == FIN_TEXT_FRAME || 
+        packet->payload[0] == BINARY_FRAME || packet->payload[0] == FIN_BINARY_FRAME || 
+        packet->payload[0] == CONNECTION_CLOSE_FRAME || packet->payload[0] == FIN_CONNECTION_CLOSE_FRAME || 
+        packet->payload[0] == PING_FRAME || packet->payload[0] == FIN_PING_FRAME || 
+        packet->payload[0] == PONG_FRAME || packet->payload[0] == FIN_PONG_FRAME) {
+
+        set_websocket_detected(ndpi_struct, flow);
+
+    } else {
+        NDPI_LOG_DBG(ndpi_struct, "Invalid WEBSOCKET payload");
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return;
+    }
+}
+
+void ndpi_search_websocket(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+    struct ndpi_packet_struct *packet = &flow->packet;
+
+    // Break after 6 packets.
+    if (flow->packet_counter > 10)
+    {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return;
+    }
+
+    if (packet->detected_protocol_stack[0] != NDPI_PROTOCOL_UNKNOWN)
+    {
+        return;
+    }
+
+    NDPI_LOG_DBG(ndpi_struct, "search WEBSOCKET\n");
+    ndpi_check_websocket(ndpi_struct, flow);
+
+    return;
+}
+
+/* ********************************* */
+
+void init_websocket_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id,
+                              NDPI_PROTOCOL_BITMASK *detection_bitmask)
+{
+    ndpi_set_bitmask_protocol_detection("WEBSOCKET", ndpi_struct, detection_bitmask, *id, NDPI_PROTOCOL_WEBSOCKET,
+                                        ndpi_search_websocket, NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD,
+                                        SAVE_DETECTION_BITMASK_AS_UNKNOWN, ADD_TO_DETECTION_BITMASK);
+
+    *id += 1;
+}