Initial import from SVN

1 files changed, 85 insertions, 0 deletions

diff --git a/src/lib/protocols/gtp.c b/src/lib/protocols/gtp.c
new file mode 100644
index 000000000..b9aee7a97
--- /dev/null
+++ b/src/lib/protocols/gtp.c
@@ -0,0 +1,85 @@
+/*
+ * gtp.c
+ *
+ * Copyright (C) 2011-15 - 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_api.h"
+
+#ifdef NDPI_PROTOCOL_GTP
+
+struct gtp_header_generic {
+  u_int8_t flags, message_type;
+  u_int16_t message_len;
+  u_int32_t teid;
+};
+
+static void ndpi_check_gtp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct *packet = &flow->packet;
+  // const u_int8_t *packet_payload = packet->payload;
+  u_int32_t payload_len = packet->payload_packet_len;
+
+#if 0
+  printf("[len=%u][%02X %02X %02X %02X]\n", payload_len,
+	 packet->payload[0] & 0xFF,
+	 packet->payload[1] & 0xFF,
+	 packet->payload[2] & 0xFF,
+	 packet->payload[3] & 0xFF);
+#endif
+
+  if((packet->udp != NULL) && (payload_len > sizeof(struct gtp_header_generic))) {
+    u_int32_t gtp_u  = ntohs(2152);
+    u_int32_t gtp_c  = ntohs(2123);
+    u_int32_t gtp_v0 = ntohs(3386);
+
+    if((packet->udp->source == gtp_u) || (packet->udp->dest == gtp_u)
+       || (packet->udp->source == gtp_c) || (packet->udp->dest == gtp_c)
+       || (packet->udp->source == gtp_v0) || (packet->udp->dest == gtp_v0)
+       ) {
+      struct gtp_header_generic *gtp = (struct gtp_header_generic*)packet->payload;
+      u_int8_t gtp_version = (gtp->flags & 0xE0) >> 5;
+
+      if((gtp_version == 0) || (gtp_version == 1) || (gtp_version == 2)) {
+	u_int16_t message_len = ntohs(gtp->message_len);
+	
+	if(message_len <= (payload_len-sizeof(struct gtp_header_generic))) {
+	  NDPI_LOG(NDPI_PROTOCOL_GTP, ndpi_struct, NDPI_LOG_DEBUG, "Found gtp.\n");
+	  ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_GTP, NDPI_REAL_PROTOCOL);
+	  return;
+	}
+      }
+    }
+  }
+
+  NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_GTP);
+  return;
+}
+
+void ndpi_search_gtp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct *packet = &flow->packet;
+
+  NDPI_LOG(NDPI_PROTOCOL_GTP, ndpi_struct, NDPI_LOG_DEBUG, "gtp detection...\n");
+
+  /* skip marked packets */
+  if(packet->detected_protocol_stack[0] != NDPI_PROTOCOL_GTP)
+    ndpi_check_gtp(ndpi_struct, flow);
+}
+
+#endif