Initial import from SVN

1 files changed, 107 insertions, 0 deletions

diff --git a/src/lib/protocols/telnet.c b/src/lib/protocols/telnet.c
new file mode 100644
index 000000000..0954be111
--- /dev/null
+++ b/src/lib/protocols/telnet.c
@@ -0,0 +1,107 @@
+/*
+ * telnet.c
+ *
+ * Copyright (C) 2009-2011 by ipoque GmbH
+ * Copyright (C) 2011-15 - ntop.org
+ *
+ * This file is part of nDPI, an open source deep packet inspection
+ * library based on the OpenDPI and PACE technology by ipoque GmbH
+ *
+ * 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_protocols.h"
+#ifdef NDPI_PROTOCOL_TELNET
+
+
+
+static void ndpi_int_telnet_add_connection(struct ndpi_detection_module_struct
+											 *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+	ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_TELNET, NDPI_REAL_PROTOCOL);
+}
+
+	
+#if !defined(WIN32)
+ static inline
+#else
+__forceinline static
+#endif
+	 u_int8_t search_iac(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+	struct ndpi_packet_struct *packet = &flow->packet;
+
+	u_int16_t a;
+
+	if (packet->payload_packet_len < 3) {
+		return 0;
+	}
+
+	if (!(packet->payload[0] == 0xff
+		  && packet->payload[1] > 0xf9 && packet->payload[1] != 0xff && packet->payload[2] < 0x28)) {
+		return 0;
+	}
+
+	a = 3;
+
+	while (a < packet->payload_packet_len - 2) {
+		// commands start with a 0xff byte followed by a command byte >= 0xf0 and < 0xff
+		// command bytes 0xfb to 0xfe are followed by an option byte <= 0x28
+		if (!(packet->payload[a] != 0xff ||
+			  (packet->payload[a] == 0xff && (packet->payload[a + 1] >= 0xf0) && (packet->payload[a + 1] <= 0xfa)) ||
+			  (packet->payload[a] == 0xff && (packet->payload[a + 1] >= 0xfb) && (packet->payload[a + 1] != 0xff)
+			   && (packet->payload[a + 2] <= 0x28)))) {
+			return 0;
+		}
+		a++;
+	}
+
+	return 1;
+}
+
+/* this detection also works asymmetrically */
+void ndpi_search_telnet_tcp(struct ndpi_detection_module_struct
+							  *ndpi_struct, struct ndpi_flow_struct *flow)
+{
+//  struct ndpi_packet_struct *packet = &flow->packet;
+	
+//      struct ndpi_id_struct         *src=ndpi_struct->src;
+//      struct ndpi_id_struct         *dst=ndpi_struct->dst;
+
+	NDPI_LOG(NDPI_PROTOCOL_TELNET, ndpi_struct, NDPI_LOG_DEBUG, "search telnet.\n");
+
+	if (search_iac(ndpi_struct, flow) == 1) {
+
+		if (flow->l4.tcp.telnet_stage == 2) {
+			NDPI_LOG(NDPI_PROTOCOL_TELNET, ndpi_struct, NDPI_LOG_DEBUG, "telnet identified.\n");
+			ndpi_int_telnet_add_connection(ndpi_struct, flow);
+			return;
+		}
+		flow->l4.tcp.telnet_stage++;
+		NDPI_LOG(NDPI_PROTOCOL_TELNET, ndpi_struct, NDPI_LOG_DEBUG, "telnet stage %u.\n", flow->l4.tcp.telnet_stage);
+		return;
+	}
+
+	if ((flow->packet_counter < 12 && flow->l4.tcp.telnet_stage > 0) || flow->packet_counter < 6) {
+		return;
+	} else {
+		NDPI_LOG(NDPI_PROTOCOL_TELNET, ndpi_struct, NDPI_LOG_DEBUG, "telnet excluded.\n");
+		NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_TELNET);
+	}
+	return;
+}
+
+#endif