Add JSON-RPC protocol dissector (#2217)

* Add JSON-RPC protocol dissector

* Small fixes

* Improve detection

1 files changed, 71 insertions, 0 deletions

diff --git a/src/lib/protocols/json-rpc.c b/src/lib/protocols/json-rpc.c
new file mode 100644
index 000000000..c989fbea4
--- /dev/null
+++ b/src/lib/protocols/json-rpc.c
@@ -0,0 +1,71 @@
+/*
+ * json-rpc.c
+ *
+ * Copyright (C) 2023 - ntop.org
+ * Copyright (C) 2023 - V.G <jacendi@protonmail.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_JSON_RPC
+
+#include "ndpi_api.h"
+#include "ndpi_private.h"
+
+static void ndpi_search_json_rpc(struct ndpi_detection_module_struct *ndpi_struct,
+                                 struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+
+  if (flow->detected_protocol_stack[0] == NDPI_PROTOCOL_HTTP ||
+      flow->detected_protocol_stack[1] == NDPI_PROTOCOL_HTTP)
+  {
+    if ((packet->content_line.ptr != NULL) &&
+        (LINE_ENDS(packet->content_line, "application/json-rpc") != 0))
+    {
+      NDPI_LOG_INFO(ndpi_struct, "found JSON-RPC over HTTP\n");
+      ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_JSON_RPC, 
+                                 NDPI_PROTOCOL_HTTP, NDPI_CONFIDENCE_DPI);
+    }
+    return;
+  }
+
+  if ((packet->payload_packet_len > 30) && (packet->payload[0] == '{') &&
+      (ndpi_strnstr((const char *)packet->payload, "\"jsonrpc\":", packet->payload_packet_len)))
+  {
+    NDPI_LOG_INFO(ndpi_struct, "found JSON-RPC over TCP\n");
+    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_JSON_RPC,
+                               NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
+    return;
+  }
+
+  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+}
+
+void init_json_rpc_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id)
+{
+  ndpi_set_bitmask_protocol_detection("JSON-RPC", ndpi_struct, *id,
+				      NDPI_PROTOCOL_JSON_RPC,
+				      ndpi_search_json_rpc,
+				      NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
+				      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+				      ADD_TO_DETECTION_BITMASK);
+  *id += 1;
+}