Add support for what appears to be 3Com's scheme for encapsulating XNS

over Token Ring (and presumably other link layers using 802.2 LLC), and
for the XNS IDP and SPP protocols.

svn path=/trunk/; revision=13577

1 files changed, 279 insertions, 0 deletions

diff --git a/epan/dissectors/packet-spp.c b/epan/dissectors/packet-spp.c
new file mode 100644
index 0000000000..0c77fca963
--- /dev/null
+++ b/epan/dissectors/packet-spp.c
@@ -0,0 +1,279 @@
+/* packet-spp.c
+ * Routines for XNS SPP
+ * Based on the Netware SPP dissector by Gilbert Ramirez <gram@alumni.rice.edu>
+ *
+ * $Id$
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include <epan/packet.h>
+#include "packet-idp.h"
+
+static int proto_spp = -1;
+static int hf_spp_connection_control = -1;
+static int hf_spp_connection_control_sys = -1;
+static int hf_spp_connection_control_send_ack = -1;
+static int hf_spp_connection_control_attn = -1;
+static int hf_spp_connection_control_eom = -1;
+static int hf_spp_datastream_type = -1;
+static int hf_spp_src_id = -1;
+static int hf_spp_dst_id = -1;
+static int hf_spp_seq_nr = -1;
+static int hf_spp_ack_nr = -1;
+static int hf_spp_all_nr = -1;
+static int hf_spp_rexmt_frame = -1;
+
+static gint ett_spp = -1;
+static gint ett_spp_connctrl = -1;
+
+static dissector_handle_t data_handle;
+
+/*
+ * See
+ *
+ *	"Internet Transport Protocols", XSIS 028112, December 1981
+ *
+ * if you can find it; this is based on the headers in the BSD XNS
+ * implementation.
+ */
+
+#define SPP_SYS_PACKET	0x80
+#define SPP_SEND_ACK	0x40
+#define SPP_ATTN	0x20
+#define SPP_EOM		0x10
+
+static const char*
+spp_conn_ctrl(guint8 ctrl)
+{
+	const char *p;
+
+	static const value_string conn_vals[] = {
+		{ 0x00,                        "Data, No Ack Required" },
+		{ SPP_EOM,                     "End-of-Message" },
+		{ SPP_ATTN,                    "Attention" },
+		{ SPP_SEND_ACK,                "Acknowledgment Required"},
+		{ SPP_SEND_ACK|SPP_EOM,        "Send Ack: End Message"},
+		{ SPP_SYS_PACKET,              "System Packet"},
+		{ SPP_SYS_PACKET|SPP_SEND_ACK, "System Packet: Send Ack"},
+		{ 0x00,                        NULL }
+	};
+
+	p = match_strval((ctrl & 0xf0), conn_vals );
+
+	if (p) {
+		return p;
+	}
+	else {
+		return "Unknown";
+	}
+}
+
+static const char*
+spp_datastream(guint8 type)
+{
+	switch (type) {
+		case 0xfe:
+			return "End-of-Connection";
+		case 0xff:
+			return "End-of-Connection Acknowledgment";
+		default:
+			return NULL;
+	}
+}
+
+#define SPP_HEADER_LEN	12
+
+/*
+ * XXX - do reassembly, using the EOM flag.  (Then do that in the Netware
+ * SPX implementation, too.)
+ *
+ * XXX - hand off to subdissectors based on the socket number.
+ */
+static void
+dissect_spp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_tree	*spp_tree = NULL;
+	proto_item	*ti;
+	tvbuff_t	*next_tvb;
+	guint8		conn_ctrl;
+	proto_tree	*cc_tree;
+	guint8		datastream_type;
+	const char	*datastream_type_string;
+	guint16         spp_seq;
+	const char	*spp_msg_string;
+
+	if (check_col(pinfo->cinfo, COL_PROTOCOL))
+		col_set_str(pinfo->cinfo, COL_PROTOCOL, "SPP");
+	if (check_col(pinfo->cinfo, COL_INFO))
+		col_set_str(pinfo->cinfo, COL_INFO, "SPP");
+
+	if (tree) {
+		ti = proto_tree_add_item(tree, proto_spp, tvb, 0, SPP_HEADER_LEN, FALSE);
+		spp_tree = proto_item_add_subtree(ti, ett_spp);
+	}
+
+	conn_ctrl = tvb_get_guint8(tvb, 0);
+	spp_msg_string = spp_conn_ctrl(conn_ctrl);
+	if (check_col(pinfo->cinfo, COL_INFO))
+		col_append_fstr(pinfo->cinfo, COL_INFO, " %s", spp_msg_string);
+	if (tree) {
+		ti = proto_tree_add_uint_format(spp_tree, hf_spp_connection_control, tvb,
+						0, 1, conn_ctrl,
+						"Connection Control: %s (0x%02X)",
+						spp_msg_string, conn_ctrl);
+		cc_tree = proto_item_add_subtree(ti, ett_spp_connctrl);
+		proto_tree_add_boolean(cc_tree, hf_spp_connection_control_sys, tvb,
+				       0, 1, conn_ctrl);
+		proto_tree_add_boolean(cc_tree, hf_spp_connection_control_send_ack, tvb,
+				       0, 1, conn_ctrl);
+		proto_tree_add_boolean(cc_tree, hf_spp_connection_control_attn, tvb,
+				       0, 1, conn_ctrl);
+		proto_tree_add_boolean(cc_tree, hf_spp_connection_control_eom, tvb,
+				       0, 1, conn_ctrl);
+	}
+
+	datastream_type = tvb_get_guint8(tvb, 1);
+	datastream_type_string = spp_datastream(datastream_type);
+	if (datastream_type_string != NULL) {
+		if (check_col(pinfo->cinfo, COL_INFO))
+			col_append_fstr(pinfo->cinfo, COL_INFO, " (%s)",
+			    datastream_type_string);
+	}
+	if (tree) {
+		if (datastream_type_string != NULL) {
+			proto_tree_add_uint_format(spp_tree, hf_spp_datastream_type, tvb,
+						   1, 1, datastream_type,
+						   "Datastream Type: %s (0x%02X)",
+						   datastream_type_string,
+						   datastream_type);
+		} else {
+			proto_tree_add_uint_format(spp_tree, hf_spp_datastream_type, tvb,
+						   1, 1, datastream_type,
+						   "Datastream Type: 0x%02X",
+						   datastream_type);
+		}
+		proto_tree_add_item(spp_tree, hf_spp_src_id, tvb,  2, 2, FALSE);
+		proto_tree_add_item(spp_tree, hf_spp_dst_id, tvb,  4, 2, FALSE);
+	}
+	spp_seq = tvb_get_ntohs(tvb, 6);
+	if (tree) {
+		proto_tree_add_uint(spp_tree, hf_spp_seq_nr, tvb,  6, 2, spp_seq);
+		proto_tree_add_item(spp_tree, hf_spp_ack_nr, tvb,  8, 2, FALSE);
+		proto_tree_add_item(spp_tree, hf_spp_all_nr, tvb, 10, 2, FALSE);
+	}
+
+	if (tvb_reported_length_remaining(tvb, SPP_HEADER_LEN) > 0) {
+		next_tvb = tvb_new_subset(tvb, SPP_HEADER_LEN, -1, -1);
+		call_dissector(data_handle, next_tvb, pinfo, tree);
+	}
+}
+
+
+void
+proto_register_spp(void)
+{
+	static hf_register_info hf_spp[] = {
+		{ &hf_spp_connection_control,
+		{ "Connection Control",		"spp.ctl",
+		  FT_UINT8,	BASE_HEX,	NULL,	0x0,
+		  "", HFILL }},
+
+		{ &hf_spp_connection_control_sys,
+		{ "System Packet",		"spp.ctl.sys",
+		  FT_BOOLEAN,	8,	NULL,	SPP_SYS_PACKET,
+		  "", HFILL }},
+
+		{ &hf_spp_connection_control_send_ack,
+		{ "Send Ack",		"spp.ctl.send_ack",
+		  FT_BOOLEAN,	8,	NULL,	SPP_SEND_ACK,
+		  "", HFILL }},
+
+		{ &hf_spp_connection_control_attn,
+		{ "Attention",		"spp.ctl.attn",
+		  FT_BOOLEAN,	8,	NULL,	SPP_ATTN,
+		  "", HFILL }},
+
+		{ &hf_spp_connection_control_eom,
+		{ "End of Message",	"spp.ctl.eom",
+		  FT_BOOLEAN,	8,	NULL,	SPP_EOM,
+		  "", HFILL }},
+
+		{ &hf_spp_datastream_type,
+		{ "Datastream type",	       	"spp.type",
+		  FT_UINT8,	BASE_HEX,	NULL,	0x0,
+		  "", HFILL }},
+
+		{ &hf_spp_src_id,
+		{ "Source Connection ID",	"spp.src",
+		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
+		  "", HFILL }},
+
+		{ &hf_spp_dst_id,
+		{ "Destination Connection ID",	"spp.dst",
+		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
+		  "", HFILL }},
+
+		{ &hf_spp_seq_nr,
+		{ "Sequence Number",		"spp.seq",
+		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
+		  "", HFILL }},
+
+		{ &hf_spp_ack_nr,
+		{ "Acknowledgment Number",	"spp.ack",
+		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
+		  "", HFILL }},
+
+		{ &hf_spp_all_nr,
+		{ "Allocation Number",		"spp.alloc",
+		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
+		  "", HFILL }},
+
+		{ &hf_spp_rexmt_frame,
+		{ "Retransmitted Frame Number",	"spp.rexmt_frame",
+		  FT_FRAMENUM,	BASE_NONE,	NULL,	0x0,
+		  "", HFILL }},
+	};
+
+	static gint *ett[] = {
+		&ett_spp,
+		&ett_spp_connctrl,
+	};
+
+	proto_spp = proto_register_protocol("Sequenced Packet Protocol",
+	    "SPP", "spp");
+	proto_register_field_array(proto_spp, hf_spp, array_length(hf_spp));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_spp(void)
+{
+	dissector_handle_t spp_handle;
+
+	spp_handle = create_dissector_handle(dissect_spp, proto_spp);
+	dissector_add("idp.packet_type", IDP_PACKET_TYPE_SPP, spp_handle);
+
+	data_handle = find_dissector("data");
+}