Add Discord dissector. (#1694)

* fixed RiotGames false positive

Signed-off-by: lns <matzeton@googlemail.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/src/lib/protocols/discord.c b/src/lib/protocols/discord.c
new file mode 100644
index 000000000..59355b00a
--- /dev/null
+++ b/src/lib/protocols/discord.c
@@ -0,0 +1,89 @@
+/*
+ * discord.c
+ *
+ * Copyright (C) 2022 - ntop.org
+ *
+ * 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_DISCORD
+
+#include "ndpi_api.h"
+
+static void ndpi_int_discord_add_connection(struct ndpi_detection_module_struct * const ndpi_struct,
+                                             struct ndpi_flow_struct * const flow)
+{
+  NDPI_LOG_INFO(ndpi_struct, "found discord\n");
+  ndpi_set_detected_protocol(ndpi_struct, flow,
+                             NDPI_PROTOCOL_DISCORD,
+                             NDPI_PROTOCOL_UNKNOWN,
+                             NDPI_CONFIDENCE_DPI);
+}
+
+void ndpi_search_discord(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 discord\n");
+
+  if (packet->payload_packet_len == 8 &&
+      ntohl(get_u_int32_t(packet->payload, 0)) == 0x1337cafe)
+  {
+    ndpi_int_discord_add_connection(ndpi_struct, flow);
+    return;
+  }
+
+  if (packet->payload_packet_len == 74 &&
+      ntohs(get_u_int16_t(packet->payload, 6)) == 0xace3)
+  {
+    if (flow->packet_counter == 1 &&
+        ntohl(get_u_int32_t(packet->payload, 0)) == 0x00010046)
+    {
+      /* Wait for the next packet, hopefully beeing able to dissect the client IP. */
+      return;
+    }
+
+    if (flow->packet_counter == 2 &&
+        ntohl(get_u_int32_t(packet->payload, 0)) == 0x00020046)
+    {
+      /* Dissect client IP. */
+      size_t len = sizeof(flow->protos.discord.client_ip) - 1;
+      strncpy(flow->protos.discord.client_ip, (char const *)&packet->payload[8], len);
+      flow->protos.discord.client_ip[len] = '\0';
+      ndpi_int_discord_add_connection(ndpi_struct, flow);
+      return;
+    }
+  }
+
+  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+}
+
+void init_discord_dissector(struct ndpi_detection_module_struct *ndpi_struct,
+                            u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
+{
+  ndpi_set_bitmask_protocol_detection("Discord", ndpi_struct, detection_bitmask, *id,
+    NDPI_PROTOCOL_DISCORD,
+    ndpi_search_discord,
+    NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_UDP_WITH_PAYLOAD,
+    SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+    ADD_TO_DETECTION_BITMASK
+  );
+
+  *id += 1;
+}