Add FastCGI protocol detection. (#1711)

* CQL: fixed byte order conversion (BigEndian not LittleEndian)
 * CQL: increased required successful dissected packets to prevent false-positives

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

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

5 files changed, 140 insertions, 4 deletions

diff --git a/src/include/ndpi_protocol_ids.h b/src/include/ndpi_protocol_ids.h
index 4f63e2a0a..b0ab19ebb 100644
--- a/src/include/ndpi_protocol_ids.h
+++ b/src/include/ndpi_protocol_ids.h
@@ -338,6 +338,7 @@ typedef enum {
   NDPI_PROTOCOL_AVAST                 = 307,
   NDPI_PROTOCOL_TIVOCONNECT           = 308,
   NDPI_PROTOCOL_KISMET                = 309,
+  NDPI_PROTOCOL_FASTCGI               = 310,
 
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_protocol_ids.h"
diff --git a/src/include/ndpi_protocols.h b/src/include/ndpi_protocols.h
index 4224e11cb..6d2696846 100644
--- a/src/include/ndpi_protocols.h
+++ b/src/include/ndpi_protocols.h
@@ -239,6 +239,7 @@ void init_activision_dissector(struct ndpi_detection_module_struct *ndpi_struct,
 void init_discord_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask);
 void init_tivoconnect_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask);
 void init_kismet_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask);
+void init_fastcgi_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask);
 
 /* ndpi_main.c */
 extern u_int32_t ndpi_ip_port_hash_funct(u_int32_t ip, u_int16_t port);
diff --git a/src/lib/ndpi_main.c b/src/lib/ndpi_main.c
index 398eb6edf..e096b8617 100644
--- a/src/lib/ndpi_main.c
+++ b/src/lib/ndpi_main.c
@@ -1970,6 +1970,10 @@ static void ndpi_init_protocol_defaults(struct ndpi_detection_module_struct *ndp
                           "Kismet", NDPI_PROTOCOL_CATEGORY_NETWORK,
                           ndpi_build_default_ports(ports_a, 0, 0, 0, 0, 0) /* TCP */,
                           ndpi_build_default_ports(ports_b, 0, 0, 0, 0, 0) /* UDP */);
+  ndpi_set_proto_defaults(ndpi_str, 1 /* cleartext */, 0 /* nw proto */, NDPI_PROTOCOL_SAFE, NDPI_PROTOCOL_FASTCGI,
+                          "FastCGI", NDPI_PROTOCOL_CATEGORY_NETWORK,
+                          ndpi_build_default_ports(ports_a, 0, 0, 0, 0, 0) /* TCP */,
+                          ndpi_build_default_ports(ports_b, 0, 0, 0, 0, 0) /* UDP */);
 
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_main.c"
@@ -4561,6 +4565,9 @@ static int ndpi_callback_init(struct ndpi_detection_module_struct *ndpi_str) {
   /* Kismet */
   init_kismet_dissector(ndpi_str, &a, detection_bitmask);
 
+  /* FastCGI */
+  init_fastcgi_dissector(ndpi_str, &a, detection_bitmask);
+
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_main_init.c"
 #endif
diff --git a/src/lib/protocols/cassandra.c b/src/lib/protocols/cassandra.c
index 154882f81..07231ac65 100644
--- a/src/lib/protocols/cassandra.c
+++ b/src/lib/protocols/cassandra.c
@@ -117,12 +117,15 @@ void ndpi_search_cassandra(struct ndpi_detection_module_struct *ndpi_struct,
         ndpi_check_valid_cassandra_version(get_u_int8_t(packet->payload, 0)) &&
         ndpi_check_valid_cassandra_flags(get_u_int8_t(packet->payload, 1)) &&
         ndpi_check_valid_cassandra_opcode(get_u_int8_t(packet->payload, 4)) &&
-        le32toh(get_u_int32_t(packet->payload, 5)) <= CASSANDRA_MAX_BODY_SIZE &&
-        le32toh(get_u_int32_t(packet->payload, 5)) >= (uint32_t) (packet->payload_packet_len - CASSANDRA_HEADER_LEN) &&
+        ntohl(get_u_int32_t(packet->payload, 5)) <= CASSANDRA_MAX_BODY_SIZE &&
+        ntohl(get_u_int32_t(packet->payload, 5)) >= (uint32_t) (packet->payload_packet_len - CASSANDRA_HEADER_LEN) &&
         flow->l4.tcp.h323_valid_packets == 0 /* To avoid clashing with H323 */ &&
         flow->socks4_stage == 0 /* To avoid clashing with SOCKS */) {
-      NDPI_LOG_INFO(ndpi_struct, "found Cassandra\n");
-      ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_CASSANDRA, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
+      if (flow->packet_counter > 3)
+      {
+        NDPI_LOG_INFO(ndpi_struct, "found Cassandra\n");
+        ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_CASSANDRA, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
+      }
       return;
     }
   }
diff --git a/src/lib/protocols/fastcgi.c b/src/lib/protocols/fastcgi.c
new file mode 100644
index 000000000..e49e8e508
--- /dev/null
+++ b/src/lib/protocols/fastcgi.c
@@ -0,0 +1,124 @@
+/*
+ * fastcgi.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_FASTCGI
+
+#include "ndpi_api.h"
+
+/* Reference: http://www.mit.edu/~yandros/doc/specs/fcgi-spec.html */
+
+PACK_ON
+struct FCGI_Header {
+  unsigned char version;
+  unsigned char type;
+  u_int16_t requestId;
+  u_int16_t contentLength;
+  unsigned char paddingLength;
+  unsigned char reserved;
+} PACK_OFF;
+
+enum FCGI_Type {
+  FCGI_MIN                = 1,
+
+  FCGI_BEGIN_REQUEST      = 1,
+  FCGI_ABORT_REQUEST      = 2,
+  FCGI_END_REQUEST        = 3,
+  FCGI_PARAMS             = 4,
+  FCGI_STDIN              = 5,
+  FCGI_STDOUT             = 6,
+  FCGI_STDERR             = 7,
+  FCGI_DATA               = 8,
+  FCGI_GET_VALUES         = 9,
+  FCGI_GET_VALUES_RESULT  = 10,
+  FCGI_UNKNOWN_TYPE       = 11,
+
+  FCGI_MAX                = 11
+};
+
+static void ndpi_int_fastcgi_add_connection(struct ndpi_detection_module_struct * const ndpi_struct,
+                                            struct ndpi_flow_struct * const flow)
+{
+  NDPI_LOG_INFO(ndpi_struct, "found fastcgi\n");
+  ndpi_set_detected_protocol(ndpi_struct, flow,
+                             NDPI_PROTOCOL_FASTCGI,
+                             NDPI_PROTOCOL_UNKNOWN,
+                             NDPI_CONFIDENCE_DPI);
+}
+
+void ndpi_search_fastcgi(struct ndpi_detection_module_struct *ndpi_struct,
+                         struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+  struct FCGI_Header const * fcgi_hdr;
+  enum FCGI_Type fcgi_type;
+  u_int16_t content_len;
+
+  NDPI_LOG_DBG(ndpi_struct, "search fastcgi\n");
+
+  if (packet->payload_packet_len < sizeof(struct FCGI_Header))
+  {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  fcgi_hdr = (struct FCGI_Header const *)&packet->payload[0];
+
+  if (fcgi_hdr->version != 0x01)
+  {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  fcgi_type = (enum FCGI_Type)fcgi_hdr->type;
+  if (fcgi_type < FCGI_MIN || fcgi_type > FCGI_MAX)
+  {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  content_len = ntohs(fcgi_hdr->contentLength);
+  if (packet->payload_packet_len != sizeof(*fcgi_hdr) + content_len + fcgi_hdr->paddingLength)
+  {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  if (flow->packet_counter > 2)
+  {
+    ndpi_int_fastcgi_add_connection(ndpi_struct, flow);
+  }
+}
+
+void init_fastcgi_dissector(struct ndpi_detection_module_struct *ndpi_struct,
+                            u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
+{
+  ndpi_set_bitmask_protocol_detection("FastCGI", ndpi_struct, detection_bitmask, *id,
+    NDPI_PROTOCOL_FASTCGI,
+    ndpi_search_fastcgi,
+    NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
+    SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+    ADD_TO_DETECTION_BITMASK
+  );
+
+  *id += 1;
+}