Add HL7 protocol dissector (#2240)

* Add HL7 protocol dissector

* Small fixes

* Small fixes

1 files changed, 82 insertions, 0 deletions

diff --git a/src/lib/protocols/hl7.c b/src/lib/protocols/hl7.c
new file mode 100644
index 000000000..193db55f4
--- /dev/null
+++ b/src/lib/protocols/hl7.c
@@ -0,0 +1,82 @@
+/*
+ * hl7.c
+ *
+ * Health Level Seven (HL7)
+ * 
+ * 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_HL7
+
+#include "ndpi_api.h"
+#include "ndpi_private.h"
+
+static void ndpi_search_hl7(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 HL7\n");
+
+  if (flow->detected_protocol_stack[0] == NDPI_PROTOCOL_HTTP ||
+      flow->detected_protocol_stack[1] == NDPI_PROTOCOL_HTTP)
+  {
+    if (packet->content_line.ptr != NULL) {
+      if ((LINE_ENDS(packet->content_line, "x-application/hl7-v2+er7") != 0) ||
+          (LINE_ENDS(packet->content_line, "x-application/hl7-v2+xml") != 0) ||
+          (LINE_ENDS(packet->content_line, "x-application/hl7-v3+xml") != 0) ||
+          (LINE_ENDS(packet->content_line, "x-application/fhir+xml") != 0)   ||
+          (LINE_ENDS(packet->content_line, "x-application/fhir+json") != 0)  ||
+          (LINE_ENDS(packet->content_line, "x-application/xml+cda") != 0))
+      {
+        NDPI_LOG_INFO(ndpi_struct, "found HL7 over HTTP\n");
+        ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_HL7, NDPI_PROTOCOL_HTTP, 
+                                   NDPI_CONFIDENCE_DPI);
+      }
+    }
+    return;
+  }
+
+  if (packet->payload_packet_len > 100 &&
+      memcmp(&packet->payload[1], "MSH|^~\\&|", NDPI_STATICSTRING_LEN("MSH|^~\\&|")) == 0)
+  {
+    NDPI_LOG_INFO(ndpi_struct, "found HL7\n");
+    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_HL7, NDPI_PROTOCOL_UNKNOWN, 
+                               NDPI_CONFIDENCE_DPI);
+    return;
+  }
+
+  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+}
+
+void init_hl7_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id)
+{
+  ndpi_set_bitmask_protocol_detection("HL7", ndpi_struct, *id,
+              NDPI_PROTOCOL_HL7,
+              ndpi_search_hl7,
+              NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
+              SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+              ADD_TO_DETECTION_BITMASK);
+
+  *id += 1;
+}