From 0c8bc9f0555fa19d56bb686a2233772ae408f77b Mon Sep 17 00:00:00 2001
From: Toni <matzeton@googlemail.com>
Date: Wed, 24 Aug 2022 13:22:46 +0200
Subject: 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>
---
src/lib/protocols/fastcgi.c | 124 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 124 insertions(+)
create mode 100644 src/lib/protocols/fastcgi.c
(limited to 'src/lib/protocols/fastcgi.c')
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;
+}
--
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