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wireshark/epan/dissectors/packet-smp.c

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/* packet-smp.c
* Routines for Session Multiplex Protocol (SMP) dissection
* January 2017 Uli Heilmeier with the help of Michael Mann
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* References:
* https://web.archive.org/web/20171009015219/https://msdn.microsoft.com/en-us/library/cc219643.aspx
* https://web.archive.org/web/20171223021159/https://msdn.microsoft.com/en-us/library/dd304523.aspx
* https://web.archive.org/web/20171005092351/https://docs.microsoft.com/en-us/sql/relational-databases/native-client/features/using-multiple-active-result-sets-mars
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SMID | FLAGS | SID |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LENGTH |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SEQNUM |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | WNDW |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* / DATA (variable) /
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
#include <config.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/decode_as.h>
#include "packet-tcp.h"
void proto_reg_handoff_smp(void);
void proto_register_smp(void);
static int proto_smp = -1;
static int hf_smp_smid = -1;
static int hf_smp_flags = -1;
static int hf_smp_flags_syn = -1;
static int hf_smp_flags_ack = -1;
static int hf_smp_flags_fin = -1;
static int hf_smp_flags_data = -1;
static int hf_smp_sid = -1;
static int hf_smp_length = -1;
static int hf_smp_seqnum = -1;
static int hf_smp_wndw = -1;
static int hf_smp_data = -1;
static gint ett_smp = -1;
static gint ett_smp_flags = -1;
#define SMP_FLAGS_SYN 0x01
#define SMP_FLAGS_ACK 0x02
#define SMP_FLAGS_FIN 0x04
#define SMP_FLAGS_DATA 0x08
#define SMP_MIN_LENGTH 16
static dissector_handle_t tds_handle;
static dissector_table_t smp_payload_table;
static gboolean reassemble_smp = TRUE;
static void smp_prompt(packet_info *pinfo _U_, gchar* result)
{
g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Payload as");
}
/* Code to actually dissect the packets */
static int
dissect_smp_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean tds_payload)
{
guint offset = 0;
guint remaining_bytes;
proto_item *ti;
proto_tree *smp_tree;
guint32 flags, sid, smp_length;
tvbuff_t* next_tvb;
int parsed_bytes;
static const int *flag_fields[] = {
&hf_smp_flags_syn,
&hf_smp_flags_ack,
&hf_smp_flags_fin,
&hf_smp_flags_data,
NULL
};
if (tvb_reported_length(tvb) < SMP_MIN_LENGTH)
return 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "SMP");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_smp, tvb, 0, -1, ENC_NA);
smp_tree = proto_item_add_subtree(ti, ett_smp);
proto_tree_add_item(smp_tree, hf_smp_smid, tvb, offset, 1, ENC_NA);
offset+=1;
proto_tree_add_bitmask(smp_tree, tvb, offset, hf_smp_flags, ett_smp_flags, flag_fields, ENC_NA);
flags = tvb_get_guint8(tvb, offset);
offset += 1;
proto_tree_add_item_ret_uint(smp_tree, hf_smp_sid, tvb, offset, 2, ENC_LITTLE_ENDIAN, &sid);
col_append_fstr(pinfo->cinfo, COL_INFO, "SID: %u", sid);
offset += 2;
if (flags & SMP_FLAGS_SYN)
col_append_str(pinfo->cinfo, COL_INFO, ", Syn");
if (flags & SMP_FLAGS_ACK)
col_append_str(pinfo->cinfo, COL_INFO, ", Ack");
if (flags & SMP_FLAGS_FIN)
col_append_str(pinfo->cinfo, COL_INFO, ", Fin");
if (flags & SMP_FLAGS_DATA)
col_append_str(pinfo->cinfo, COL_INFO, ", Data");
proto_tree_add_item_ret_uint(smp_tree, hf_smp_length, tvb, offset, 4, ENC_LITTLE_ENDIAN, &smp_length);
offset += 4;
proto_tree_add_item(smp_tree, hf_smp_seqnum, tvb, offset, 4, ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(smp_tree, hf_smp_wndw, tvb, offset, 4, ENC_LITTLE_ENDIAN);
offset += 4;
if ((flags & SMP_FLAGS_DATA) && (tvb_reported_length(tvb) > SMP_MIN_LENGTH)) {
next_tvb = tvb_new_subset_remaining(tvb, offset);
if (tds_payload) {
parsed_bytes = call_dissector(tds_handle, next_tvb, pinfo, tree);
} else {
parsed_bytes = dissector_try_payload(smp_payload_table, next_tvb, pinfo, tree);
}
if (parsed_bytes <= 0)
{
remaining_bytes = tvb_reported_length_remaining(tvb, offset);
if ( remaining_bytes < (smp_length - SMP_MIN_LENGTH)) {
// Fragmented
proto_tree_add_item(smp_tree, hf_smp_data, tvb, offset, remaining_bytes, ENC_NA);
offset += remaining_bytes;
}
else {
proto_tree_add_item(smp_tree, hf_smp_data, tvb, offset, smp_length - SMP_MIN_LENGTH, ENC_NA);
offset += (smp_length - SMP_MIN_LENGTH);
}
}
else {
offset += parsed_bytes;
}
}
return offset;
}
static guint get_smp_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
{
return tvb_get_letohl(tvb, offset + 4);
}
static int
dissect_smp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
return dissect_smp_common(tvb, pinfo, tree, FALSE);
}
static int dissect_smp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
{
if ((tvb_reported_length(tvb) > 0) && (tvb_get_guint8(tvb, 0) == 0x53)) {
tcp_dissect_pdus(tvb, pinfo, tree, reassemble_smp, SMP_MIN_LENGTH,
get_smp_pdu_len, dissect_smp_pdu, data);
return tvb_captured_length(tvb);
}
return 0;
}
static int
dissect_smp_tds(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
return dissect_smp_common(tvb, pinfo, tree, TRUE);
}
void
proto_register_smp(void)
{
static hf_register_info hf[] = {
{ &hf_smp_smid,
{ "Smid", "smp.smid", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }},
{ &hf_smp_flags,
{ "Flags", "smp.flags", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL } },
{ &hf_smp_flags_syn,
{ "Syn", "smp.flags.syn", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_SYN, NULL, HFILL }},
{ &hf_smp_flags_ack,
{ "Ack", "smp.flags.ack", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_ACK, NULL, HFILL }},
{ &hf_smp_flags_fin,
{ "Fin", "smp.flags.fin", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_FIN, NULL, HFILL }},
{ &hf_smp_flags_data,
{ "Data", "smp.flags.data", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_DATA, NULL, HFILL }},
{ &hf_smp_sid,
{ "SID", "smp.sid", FT_UINT16, BASE_DEC, NULL, 0, "Session ID", HFILL }},
{ &hf_smp_length,
{ "Length", "smp.length", FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }},
{ &hf_smp_seqnum,
{ "SeqNum", "smp.seqnum", FT_UINT32, BASE_HEX, NULL, 0, "Sequence Number", HFILL }},
{ &hf_smp_wndw,
{ "Wndw", "smp.wndw", FT_UINT32, BASE_HEX, NULL, 0, "Window Size", HFILL }},
{ &hf_smp_data,
{ "Data", "smp.data", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},
};
static gint *ett[] = {
&ett_smp,
&ett_smp_flags,
};
module_t *smp_module;
proto_smp = proto_register_protocol("Session Multiplex Protocol", "SMP", "smp");
proto_register_field_array(proto_smp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
register_dissector("smp_tds", dissect_smp_tds, proto_smp);
smp_payload_table = register_decode_as_next_proto(proto_smp, "SMP Payload", "smp.payload", "SMP Payload", (build_label_func*)&smp_prompt);
smp_module = prefs_register_protocol(proto_smp, NULL);
prefs_register_bool_preference(smp_module, "desegment",
"Reassemble SMP messages spanning multiple TCP segments",
"Whether the SMP dissector should reassemble messages spanning multiple TCP segments."
" To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
&reassemble_smp);
}
void
proto_reg_handoff_smp(void)
{
dissector_handle_t smp_handle;
smp_handle = create_dissector_handle(dissect_smp, proto_smp);
dissector_add_for_decode_as_with_preference("tcp.port", smp_handle);
tds_handle = find_dissector_add_dependency("tds", proto_smp);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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