Added capwap support

1 files changed, 123 insertions, 0 deletions

diff --git a/src/lib/protocols/capwap.c b/src/lib/protocols/capwap.c
new file mode 100644
index 000000000..bfad1a593
--- /dev/null
+++ b/src/lib/protocols/capwap.c
@@ -0,0 +1,123 @@
+/*
+ * capwap.c
+ *
+ * Copyright (C) 2019 - 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_CAPWAP
+
+#include "ndpi_api.h"
+
+#define NDPI_CAPWAP_CONTROL_PORT 5246
+#define NDPI_CAPWAP_DATA_PORT    5247
+
+
+static void ndpi_int_capwap_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
+					   struct ndpi_flow_struct *flow) {
+  ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_CAPWAP, NDPI_PROTOCOL_UNKNOWN);
+}
+
+/* ************************************************** */
+
+static void ndpi_search_setup_capwap(struct ndpi_detection_module_struct *ndpi_struct,
+				     struct ndpi_flow_struct *flow) {
+  struct ndpi_packet_struct *packet = &flow->packet;
+  u_int16_t sport, dport;
+   
+  if(!packet->iph) {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  sport = ntohs(packet->udp->source), dport = ntohs(packet->udp->dest);
+  
+  if((dport == NDPI_CAPWAP_CONTROL_PORT)
+     && (packet->iph->daddr == 0xFFFFFFFF)
+     && (packet->payload_packet_len >= 16)
+     && (packet->payload[0] == 0x0)
+     && (packet->payload[8] == 6 /* Mac len */)
+     )
+    goto capwap_found;
+  
+  if(((sport == NDPI_CAPWAP_CONTROL_PORT) || (dport == NDPI_CAPWAP_CONTROL_PORT))
+     && ((packet->payload[0] == 0x0) || (packet->payload[0] == 0x1))
+     ) {
+    u_int16_t msg_len, offset, to_add;
+
+    if(packet->payload[0] == 0x0)
+      offset = 13, to_add = 13;
+    else
+      offset = 15, to_add = 17;
+
+    msg_len = ntohs(*(u_int16_t*)&packet->payload[offset]);
+
+    if((msg_len+to_add) == packet->payload_packet_len)
+      goto capwap_found;
+  }
+  
+  if(
+     (((dport == NDPI_CAPWAP_DATA_PORT) && (packet->iph->daddr != 0xFFFFFFFF)) || (sport == NDPI_CAPWAP_DATA_PORT))
+     && (packet->payload_packet_len >= 16)
+     && (packet->payload[0] == 0x0)
+     ) {
+    u_int8_t is_80211_data = (packet->payload[9] & 0x0C) >> 2;
+
+      
+    if((sport == NDPI_CAPWAP_DATA_PORT) && (is_80211_data == 2 /* IEEE 802.11 Data */))
+      goto capwap_found;
+    else if(dport == NDPI_CAPWAP_DATA_PORT) {
+      u_int16_t msg_len = ntohs(*(u_int16_t*)&packet->payload[13]);
+      
+      if((packet->payload[8] == 1 /* Mac len */)
+	 || (packet->payload[8] == 6 /* Mac len */)
+	 || (packet->payload[8] == 4 /* Wireless len */)
+	 || ((msg_len+15) == packet->payload_packet_len))
+	goto capwap_found;	 
+    }
+  }
+  
+  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+  return;
+
+ capwap_found:
+  ndpi_int_capwap_add_connection(ndpi_struct, flow);
+}
+
+void ndpi_search_capwap(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct *packet = &flow->packet;
+
+  if(packet->udp && (packet->detected_protocol_stack[0] == NDPI_PROTOCOL_UNKNOWN))
+    ndpi_search_setup_capwap(ndpi_struct, flow);
+}
+
+
+void init_capwap_dissector(struct ndpi_detection_module_struct *ndpi_struct,
+			   u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
+{
+  ndpi_set_bitmask_protocol_detection("CAPWAP", ndpi_struct, detection_bitmask, *id,
+				      NDPI_PROTOCOL_CAPWAP,
+				      ndpi_search_capwap,
+				      NDPI_SELECTION_BITMASK_PROTOCOL_UDP_WITH_PAYLOAD,
+				      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+				      ADD_TO_DETECTION_BITMASK);
+
+  *id += 1;
+}