Add JSON-RPC protocol dissector (#2217)

* Add JSON-RPC protocol dissector

* Small fixes

* Improve detection

4 files changed, 84 insertions, 3 deletions

diff --git a/src/include/ndpi_protocol_ids.h b/src/include/ndpi_protocol_ids.h
index 360daa4e3..d63aae48b 100644
--- a/src/include/ndpi_protocol_ids.h
+++ b/src/include/ndpi_protocol_ids.h
@@ -403,6 +403,7 @@ typedef enum {
   NDPI_PROTOCOL_HISLIP                = 372,
   NDPI_PROTOCOL_UFTP                  = 373,
   NDPI_PROTOCOL_OPENFLOW              = 374,
+  NDPI_PROTOCOL_JSON_RPC              = 375,
 
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_protocol_ids.h"
diff --git a/src/lib/ndpi_main.c b/src/lib/ndpi_main.c
index eba83ea4b..f590f2879 100644
--- a/src/lib/ndpi_main.c
+++ b/src/lib/ndpi_main.c
@@ -1085,6 +1085,7 @@ static void ndpi_init_protocol_defaults(struct ndpi_detection_module_struct *ndp
 			      NDPI_PROTOCOL_MPEGDASH,
 			      NDPI_PROTOCOL_RTSP,
 			      NDPI_PROTOCOL_APACHE_THRIFT,
+			      NDPI_PROTOCOL_JSON_RPC,
 			      NDPI_PROTOCOL_MATCHED_BY_CONTENT,
 			      NDPI_PROTOCOL_NO_MORE_SUBPROTOCOLS); /* NDPI_PROTOCOL_HTTP can have (content-matched) subprotocols */
   ndpi_set_proto_defaults(ndpi_str, 1 /* cleartext */, 0 /* nw proto */, NDPI_PROTOCOL_ACCEPTABLE, NDPI_PROTOCOL_MDNS,
@@ -2195,13 +2196,17 @@ static void ndpi_init_protocol_defaults(struct ndpi_detection_module_struct *ndp
 			  ndpi_build_default_ports(ports_a, 4880, 0, 0, 0, 0) /* TCP */,
 			  ndpi_build_default_ports(ports_b, 0, 0, 0, 0, 0) /* UDP */);
   ndpi_set_proto_defaults(ndpi_str, 0 /* encrypted */, 0 /* nw proto */, NDPI_PROTOCOL_ACCEPTABLE, NDPI_PROTOCOL_UFTP,
-        "UFTP", NDPI_PROTOCOL_CATEGORY_DOWNLOAD_FT,
-        ndpi_build_default_ports(ports_a, 0, 0, 0, 0, 0) /* TCP */,
-        ndpi_build_default_ports(ports_b, 1044, 0, 0, 0, 0) /* UDP */);
+			  "UFTP", NDPI_PROTOCOL_CATEGORY_DOWNLOAD_FT,
+			  ndpi_build_default_ports(ports_a, 0, 0, 0, 0, 0) /* TCP */,
+			  ndpi_build_default_ports(ports_b, 1044, 0, 0, 0, 0) /* UDP */);
   ndpi_set_proto_defaults(ndpi_str, 1 /* cleartext */, 0 /* nw proto */, NDPI_PROTOCOL_ACCEPTABLE, NDPI_PROTOCOL_OPENFLOW,
 			  "OpenFlow", NDPI_PROTOCOL_CATEGORY_NETWORK,
 			  ndpi_build_default_ports(ports_a, 6653, 0, 0, 0, 0) /* TCP */,
 			  ndpi_build_default_ports(ports_b, 0, 0, 0, 0, 0) /* UDP */);
+  ndpi_set_proto_defaults(ndpi_str, 1 /* cleartext */, 0 /* nw proto */, NDPI_PROTOCOL_ACCEPTABLE, NDPI_PROTOCOL_JSON_RPC,
+			  "JSON-RPC", NDPI_PROTOCOL_CATEGORY_RPC,
+			  ndpi_build_default_ports(ports_a, 0, 0, 0, 0, 0) /* TCP */,
+			  ndpi_build_default_ports(ports_b, 0, 0, 0, 0, 0) /* UDP */);
 
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_main.c"
@@ -5702,6 +5707,9 @@ static int ndpi_callback_init(struct ndpi_detection_module_struct *ndpi_str) {
   /* OpenFlow */
   init_openflow_dissector(ndpi_str, &a);
 
+  /* JSON-RPC */
+  init_json_rpc_dissector(ndpi_str, &a);
+
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_main_init.c"
 #endif
diff --git a/src/lib/ndpi_private.h b/src/lib/ndpi_private.h
index 30fa6254e..02af0b698 100644
--- a/src/lib/ndpi_private.h
+++ b/src/lib/ndpi_private.h
@@ -638,6 +638,7 @@ void init_profinet_io_dissector(struct ndpi_detection_module_struct *ndpi_struct
 void init_hislip_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
 void init_uftp_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
 void init_openflow_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
+void init_json_rpc_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
 
 #endif
 
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;
+}