Add detection of Tailscale (#1857)

Extend the example of wireguard traffic

1 files changed, 59 insertions, 0 deletions

diff --git a/src/lib/protocols/tailscale.c b/src/lib/protocols/tailscale.c
new file mode 100644
index 000000000..ac6669ccc
--- /dev/null
+++ b/src/lib/protocols/tailscale.c
@@ -0,0 +1,59 @@
+/*
+ * tailscale.c
+ *
+ * Copyright (C) 2022 - ntop.org
+ *
+ * nDPI is free software: you can zmqtribute 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_TAILSCALE
+
+#include "ndpi_api.h"
+
+/* https://github.com/tailscale/tailscale/blob/main/disco/disco.go
+ * https://tailscale.com/kb/1082/firewall-ports/
+ */
+
+static void ndpi_search_tailscale(struct ndpi_detection_module_struct *ndpi_struct,
+				  struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct *packet = &ndpi_struct->packet;
+  unsigned char magic[6] = { 0x54, 0x53, 0xf0, 0x9f, 0x92, 0xac };
+  unsigned short port = 41641;
+
+  NDPI_LOG_DBG(ndpi_struct, "search Tailscale\n");
+
+  if(packet->payload_packet_len > sizeof(magic) &&
+     (ntohs(flow->c_port) == port || ntohs(flow->s_port) == port) &&
+     memcmp(packet->payload, magic, sizeof(magic)) == 0) {
+    NDPI_LOG_INFO(ndpi_struct, "found Tailscale\n");
+    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_TAILSCALE, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
+    return;
+  }
+
+  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+}
+
+void init_tailscale_dissector(struct ndpi_detection_module_struct *ndpi_struct,
+			      u_int32_t *id) {
+  ndpi_set_bitmask_protocol_detection("Tailscale", ndpi_struct, *id,
+				      NDPI_PROTOCOL_TAILSCALE,
+				      ndpi_search_tailscale,
+				      NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_UDP_WITH_PAYLOAD,
+				      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+				      ADD_TO_DETECTION_BITMASK);
+  *id += 1;
+}