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/* packet-spp.c
* Routines for XNS SPP
* Based on the Netware SPX dissector by Gilbert Ramirez <gram@alumni.rice.edu>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include "packet-idp.h"
void proto_register_spp(void);
void proto_reg_handoff_spp(void);
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_table_t spp_socket_dissector_table;
/*
* 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)
{
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 }
};
return val_to_str_const((ctrl & 0xf0), conn_vals, "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 int
dissect_spp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_tree *spp_tree;
proto_item *ti;
tvbuff_t *next_tvb;
guint8 conn_ctrl;
guint8 datastream_type;
const char *datastream_type_string;
guint16 spp_seq;
const char *spp_msg_string;
guint16 low_socket, high_socket;
static const int * ctrl[] = {
&hf_spp_connection_control_sys,
&hf_spp_connection_control_send_ack,
&hf_spp_connection_control_attn,
&hf_spp_connection_control_eom,
NULL
};
col_set_str(pinfo->cinfo, COL_PROTOCOL, "SPP");
col_set_str(pinfo->cinfo, COL_INFO, "SPP");
ti = proto_tree_add_item(tree, proto_spp, tvb, 0, SPP_HEADER_LEN, ENC_NA);
spp_tree = proto_item_add_subtree(ti, ett_spp);
conn_ctrl = tvb_get_guint8(tvb, 0);
spp_msg_string = spp_conn_ctrl(conn_ctrl);
col_append_fstr(pinfo->cinfo, COL_INFO, " %s", spp_msg_string);
proto_tree_add_bitmask_with_flags(spp_tree, tvb, 0, hf_spp_connection_control, ett_spp_connctrl,
ctrl, ENC_NA, BMT_NO_FALSE);
datastream_type = tvb_get_guint8(tvb, 1);
datastream_type_string = spp_datastream(datastream_type);
if (datastream_type_string != NULL) {
col_append_fstr(pinfo->cinfo, COL_INFO, " (%s)", datastream_type_string);
}
if (tree) {
if (datastream_type_string != NULL) {
proto_tree_add_uint_format_value(spp_tree, hf_spp_datastream_type, tvb,
1, 1, datastream_type,
"%s (0x%02X)",
datastream_type_string,
datastream_type);
} else {
proto_tree_add_uint(spp_tree, hf_spp_datastream_type, tvb,
1, 1, datastream_type);
}
proto_tree_add_item(spp_tree, hf_spp_src_id, tvb, 2, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(spp_tree, hf_spp_dst_id, tvb, 4, 2, ENC_BIG_ENDIAN);
}
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, ENC_BIG_ENDIAN);
proto_tree_add_item(spp_tree, hf_spp_all_nr, tvb, 10, 2, ENC_BIG_ENDIAN);
}
if (tvb_reported_length_remaining(tvb, SPP_HEADER_LEN) > 0) {
if (pinfo->srcport > pinfo->destport) {
low_socket = pinfo->destport;
high_socket = pinfo->srcport;
} else {
low_socket = pinfo->srcport;
high_socket = pinfo->destport;
}
next_tvb = tvb_new_subset_remaining(tvb, SPP_HEADER_LEN);
if (dissector_try_uint(spp_socket_dissector_table, low_socket,
next_tvb, pinfo, tree))
return tvb_captured_length(tvb);
if (dissector_try_uint(spp_socket_dissector_table, high_socket,
next_tvb, pinfo, tree))
return tvb_captured_length(tvb);
call_data_dissector(next_tvb, pinfo, tree);
}
return tvb_captured_length(tvb);
}
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,
NULL, HFILL }},
{ &hf_spp_connection_control_sys,
{ "System Packet", "spp.ctl.sys",
FT_BOOLEAN, 8, NULL, SPP_SYS_PACKET,
NULL, HFILL }},
{ &hf_spp_connection_control_send_ack,
{ "Send Ack", "spp.ctl.send_ack",
FT_BOOLEAN, 8, NULL, SPP_SEND_ACK,
NULL, HFILL }},
{ &hf_spp_connection_control_attn,
{ "Attention", "spp.ctl.attn",
FT_BOOLEAN, 8, NULL, SPP_ATTN,
NULL, HFILL }},
{ &hf_spp_connection_control_eom,
{ "End of Message", "spp.ctl.eom",
FT_BOOLEAN, 8, NULL, SPP_EOM,
NULL, HFILL }},
{ &hf_spp_datastream_type,
{ "Datastream Type", "spp.type",
FT_UINT8, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_spp_src_id,
{ "Source Connection ID", "spp.src",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_spp_dst_id,
{ "Destination Connection ID", "spp.dst",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_spp_seq_nr,
{ "Sequence Number", "spp.seq",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_spp_ack_nr,
{ "Acknowledgment Number", "spp.ack",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_spp_all_nr,
{ "Allocation Number", "spp.alloc",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
#if 0
{ &hf_spp_rexmt_frame,
{ "Retransmitted Frame Number", "spp.rexmt_frame",
FT_FRAMENUM, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
#endif
};
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));
spp_socket_dissector_table = register_dissector_table("spp.socket",
"SPP socket", proto_spp, FT_UINT16, BASE_HEX);
}
void
proto_reg_handoff_spp(void)
{
dissector_handle_t spp_handle;
spp_handle = create_dissector_handle(dissect_spp, proto_spp);
dissector_add_uint("idp.packet_type", IDP_PACKET_TYPE_SPP, spp_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
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