Add IEC62056 (DLMS/COSEM) protocol dissector (#2229)

* Add IEC62056 (DLMS/COSEM) protocol dissector

* Fix detection on big endian architectures

* Update protocols.rst

* Add ndpi_crc16_x25 to fuzz/fuzz_alg_crc32_md5.c

* Update pcap sample

* Remove empty .out file

* iec62056: add some documentation

---------

Co-authored-by: Nardi Ivan <nardi.ivan@gmail.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/src/lib/protocols/iec62056.c b/src/lib/protocols/iec62056.c
new file mode 100644
index 000000000..10542c7ba
--- /dev/null
+++ b/src/lib/protocols/iec62056.c
@@ -0,0 +1,74 @@
+/*
+ * iec62056.c
+ *
+ * IEC 62056-4-7 DLMS/COSEM transport layer for IP networks
+ * 
+ * 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_IEC62056
+
+#include "ndpi_api.h"
+#include "ndpi_private.h"
+
+static void ndpi_int_iec62056_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
+                                             struct ndpi_flow_struct *flow)
+{
+  NDPI_LOG_INFO(ndpi_struct, "found IEC62056\n");
+  ndpi_set_detected_protocol(ndpi_struct, flow,
+                             NDPI_PROTOCOL_IEC62056, NDPI_PROTOCOL_UNKNOWN,
+                             NDPI_CONFIDENCE_DPI);
+}
+
+static void ndpi_search_iec62056(struct ndpi_detection_module_struct *ndpi_struct,
+                                 struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+
+  NDPI_LOG_DBG(ndpi_struct, "search IEC62056\n");
+
+  if (packet->payload_packet_len > 8 && /* Smallest suitable packet (SNRM request) is 9 bytes long */
+      packet->payload[0] == 0x7E && packet->payload[1] == 0xA0 && /* HDLC frame start */
+      packet->payload[packet->payload_packet_len-1] == 0x7E) /* HDLC frame end */
+  {
+    u_int16_t fcs = le16toh(ndpi_crc16_x25(&packet->payload[1], packet->payload_packet_len-4));
+    if (fcs == get_u_int16_t(packet->payload, packet->payload_packet_len-3)) {
+      ndpi_int_iec62056_add_connection(ndpi_struct,  flow);
+      return;
+    }
+  }
+
+  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+}
+
+void init_iec62056_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id)
+{
+  ndpi_set_bitmask_protocol_detection("IEC62056", ndpi_struct, *id,
+                                      NDPI_PROTOCOL_IEC62056,
+                                      ndpi_search_iec62056,
+                                      NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
+                                      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+                                      ADD_TO_DETECTION_BITMASK);
+
+  *id += 1;
+}