forked from osmocom/wireshark
333 lines
9.5 KiB
C
333 lines
9.5 KiB
C
/* packet-sscop.c
|
|
* Routines for SSCOP (Q.2110, Q.SAAL) frame disassembly
|
|
* Guy Harris <guy@alum.mit.edu>
|
|
*
|
|
* $Id: packet-sscop.c,v 1.20 2002/08/28 21:00:35 jmayer Exp $
|
|
*
|
|
* Ethereal - Network traffic analyzer
|
|
* By Gerald Combs <gerald@ethereal.com>
|
|
* Copyright 1998
|
|
*
|
|
*
|
|
* 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 <stdio.h>
|
|
#include <glib.h>
|
|
#include <string.h>
|
|
#include <epan/packet.h>
|
|
|
|
static int proto_sscop = -1;
|
|
|
|
static gint ett_sscop = -1;
|
|
|
|
static dissector_handle_t q2931_handle;
|
|
static dissector_handle_t data_handle;
|
|
|
|
/*
|
|
* See
|
|
*
|
|
* http://www.protocols.com/pbook/atmsig.htm
|
|
*
|
|
* for some information on SSCOP, although, alas, not the actual PDU
|
|
* type values - those I got from the FreeBSD 3.2 ATM code.
|
|
*/
|
|
|
|
/*
|
|
* SSCOP PDU types.
|
|
*/
|
|
#define SSCOP_TYPE_MASK 0x0f
|
|
|
|
#define SSCOP_BGN 0x01 /* Begin */
|
|
#define SSCOP_BGAK 0x02 /* Begin Acknowledge */
|
|
#define SSCOP_BGREJ 0x07 /* Begin Reject */
|
|
#define SSCOP_END 0x03 /* End */
|
|
#define SSCOP_ENDAK 0x04 /* End Acknowledge */
|
|
#define SSCOP_RS 0x05 /* Resynchronization */
|
|
#define SSCOP_RSAK 0x06 /* Resynchronization Acknowledge */
|
|
#define SSCOP_SD 0x08 /* Sequenced Data */
|
|
#define SSCOP_SDP 0x09 /* Sequenced Data with Poll */
|
|
#define SSCOP_POLL 0x0a /* Status Request */
|
|
#define SSCOP_STAT 0x0b /* Solicited Status Response */
|
|
#define SSCOP_USTAT 0x0c /* Unsolicited Status Response */
|
|
#define SSCOP_UD 0x0d /* Unnumbered Data */
|
|
#define SSCOP_MD 0x0e /* Management Data */
|
|
#define SSCOP_ER 0x09 /* Error Recovery */
|
|
#define SSCOP_ERAK 0x0f /* Error Acknowledge */
|
|
|
|
#define SSCOP_S 0x10 /* Source bit in End PDU */
|
|
|
|
/*
|
|
* XXX - how to distinguish SDP from ER?
|
|
*/
|
|
static const value_string sscop_type_vals[] = {
|
|
{ SSCOP_BGN, "Begin" },
|
|
{ SSCOP_BGAK, "Begin Acknowledge" },
|
|
{ SSCOP_BGREJ, "Begin Reject" },
|
|
{ SSCOP_END, "End" },
|
|
{ SSCOP_ENDAK, "End Acknowledge" },
|
|
{ SSCOP_RS, "Resynchronization" },
|
|
{ SSCOP_RSAK, "Resynchronization Acknowledge" },
|
|
{ SSCOP_SD, "Sequenced Data" },
|
|
#if 0
|
|
{ SSCOP_SDP, "Sequenced Data with Poll" },
|
|
#endif
|
|
{ SSCOP_POLL, "Status Request" },
|
|
{ SSCOP_STAT, "Solicited Status Response" },
|
|
{ SSCOP_USTAT, "Unsolicited Status Response" },
|
|
{ SSCOP_UD, "Unnumbered Data" },
|
|
{ SSCOP_MD, "Management Data" },
|
|
{ SSCOP_ER, "Error Recovery" },
|
|
{ SSCOP_ERAK, "Error Acknowledge" },
|
|
{ 0, NULL }
|
|
};
|
|
|
|
/*
|
|
* The SSCOP "header" is a trailer, so the "offsets" are computed based
|
|
* on the length of the packet.
|
|
*/
|
|
|
|
/*
|
|
* PDU type.
|
|
*/
|
|
#define SSCOP_PDU_TYPE (reported_length - 4) /* single byte */
|
|
|
|
/*
|
|
* Begin PDU, Begin Acknowledge PDU (no N(SQ) in it), Resynchronization
|
|
* PDU, Resynchronization Acknowledge PDU (no N(SQ) in it in Q.SAAL),
|
|
* Error Recovery PDU, Error Recovery Acknoledge PDU (no N(SQ) in it).
|
|
*/
|
|
#define SSCOP_N_SQ (reported_length - 5) /* One byte */
|
|
#define SSCOP_N_MR (reported_length - 4) /* lower 3 bytes thereof */
|
|
|
|
/*
|
|
* Sequenced Data PDU (no N(PS) in it), Sequenced Data with Poll PDU,
|
|
* Poll PDU.
|
|
*/
|
|
#define SSCOP_N_PS (reported_length - 8) /* lower 3 bytes thereof */
|
|
#define SSCOP_N_S (reported_length - 4) /* lower 3 bytes thereof */
|
|
|
|
/*
|
|
* Solicited Status PDU, Unsolicited Status PDU (no N(PS) in it).
|
|
*/
|
|
#define SSCOP_SS_N_PS (reported_length - 12) /* lower 3 bytes thereof */
|
|
#define SSCOP_SS_N_MR (reported_length - 8) /* lower 3 bytes thereof */
|
|
#define SSCOP_SS_N_R (reported_length - 4) /* lower 3 bytes thereof */
|
|
|
|
static void
|
|
dissect_sscop(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
guint reported_length;
|
|
proto_item *ti;
|
|
proto_tree *sscop_tree = NULL;
|
|
guint8 sscop_pdu_type;
|
|
guint8 pdu_type;
|
|
int pdu_len;
|
|
int pad_len;
|
|
tvbuff_t *next_tvb;
|
|
|
|
reported_length = tvb_reported_length(tvb); /* frame length */
|
|
sscop_pdu_type = tvb_get_guint8(tvb, SSCOP_PDU_TYPE);
|
|
pdu_type = sscop_pdu_type & SSCOP_TYPE_MASK;
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "SSCOP");
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_add_str(pinfo->cinfo, COL_INFO, val_to_str(pdu_type, sscop_type_vals,
|
|
"Unknown PDU type (0x%02x)"));
|
|
|
|
/*
|
|
* Find the length of the PDU and, if there's any payload and
|
|
* padding, the length of the padding.
|
|
*/
|
|
switch (pdu_type) {
|
|
|
|
case SSCOP_SD:
|
|
pad_len = (sscop_pdu_type >> 6) & 0x03;
|
|
pdu_len = 4;
|
|
break;
|
|
|
|
case SSCOP_BGN:
|
|
case SSCOP_BGAK:
|
|
case SSCOP_BGREJ:
|
|
case SSCOP_END:
|
|
case SSCOP_RS:
|
|
#if 0
|
|
case SSCOP_SDP:
|
|
#endif
|
|
pad_len = (sscop_pdu_type >> 6) & 0x03;
|
|
pdu_len = 8;
|
|
break;
|
|
|
|
case SSCOP_UD:
|
|
pad_len = (sscop_pdu_type >> 6) & 0x03;
|
|
pdu_len = 4;
|
|
break;
|
|
|
|
default:
|
|
pad_len = 0;
|
|
pdu_len = reported_length; /* No payload, just SSCOP */
|
|
break;
|
|
}
|
|
if (tree) {
|
|
ti = proto_tree_add_protocol_format(tree, proto_sscop, tvb,
|
|
reported_length - pdu_len,
|
|
pdu_len, "SSCOP");
|
|
sscop_tree = proto_item_add_subtree(ti, ett_sscop);
|
|
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_PDU_TYPE, 1,
|
|
"PDU Type: %s",
|
|
val_to_str(pdu_type, sscop_type_vals,
|
|
"Unknown (0x%02x)"));
|
|
|
|
switch (pdu_type) {
|
|
|
|
case SSCOP_BGN:
|
|
case SSCOP_RS:
|
|
case SSCOP_ER:
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_N_SQ, 1,
|
|
"N(SQ): %u", tvb_get_guint8(tvb, SSCOP_N_SQ));
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_N_MR + 1, 3,
|
|
"N(MR): %u", tvb_get_ntohl(tvb, SSCOP_N_MR) & 0xFFFFFF);
|
|
break;
|
|
|
|
case SSCOP_END:
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_PDU_TYPE, 1,
|
|
"Source: %s", (sscop_pdu_type & SSCOP_S) ? "SSCOP" : "User");
|
|
break;
|
|
|
|
case SSCOP_BGAK:
|
|
case SSCOP_RSAK:
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_N_MR + 1, 3,
|
|
"N(MR): %u", tvb_get_ntohl(tvb, SSCOP_N_MR) & 0xFFFFFF);
|
|
break;
|
|
|
|
case SSCOP_ERAK:
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_N_MR + 3, 3,
|
|
"N(MR): %u", tvb_get_ntohl(tvb, SSCOP_N_MR) & 0xFFFFFF);
|
|
break;
|
|
|
|
case SSCOP_SD:
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_N_S + 1, 3,
|
|
"N(S): %u", tvb_get_ntohl(tvb, SSCOP_N_S) & 0xFFFFFF);
|
|
break;
|
|
|
|
#if 0
|
|
case SSCOP_SDP:
|
|
#endif
|
|
case SSCOP_POLL:
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_N_PS + 1, 3,
|
|
"N(PS): %u", tvb_get_ntohl(tvb, SSCOP_N_PS) & 0xFFFFFF);
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_N_S + 1, 3,
|
|
"N(S): %u", tvb_get_ntohl(tvb, SSCOP_N_S) & 0xFFFFFF);
|
|
break;
|
|
|
|
case SSCOP_STAT:
|
|
/*
|
|
* XXX - dissect the list elements....
|
|
*/
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_SS_N_PS + 1, 3,
|
|
"N(PS): %u", tvb_get_ntohl(tvb, SSCOP_SS_N_PS) & 0xFFFFFF);
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_SS_N_MR + 1, 3,
|
|
"N(MR): %u", tvb_get_ntohl(tvb, SSCOP_SS_N_MR) & 0xFFFFFF);
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_SS_N_R + 1, 3,
|
|
"N(R): %u", tvb_get_ntohl(tvb, SSCOP_SS_N_R) & 0xFFFFFF);
|
|
break;
|
|
|
|
case SSCOP_USTAT:
|
|
/*
|
|
* XXX - dissect the list elements....
|
|
*/
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_SS_N_MR + 1, 3,
|
|
"N(MR): %u", tvb_get_ntohl(tvb, SSCOP_SS_N_MR) & 0xFFFFFF);
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_SS_N_R + 1, 3,
|
|
"N(R): %u", tvb_get_ntohl(tvb, SSCOP_SS_N_R) & 0xFFFFFF);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Dissect the payload, if any.
|
|
*
|
|
* XXX - what about a Management Data PDU?
|
|
*/
|
|
switch (pdu_type) {
|
|
|
|
case SSCOP_SD:
|
|
case SSCOP_UD:
|
|
case SSCOP_BGN:
|
|
case SSCOP_BGAK:
|
|
case SSCOP_BGREJ:
|
|
case SSCOP_END:
|
|
case SSCOP_RS:
|
|
#if 0
|
|
case SSCOP_SDP:
|
|
#endif
|
|
if (tree) {
|
|
proto_tree_add_text(sscop_tree, tvb, SSCOP_PDU_TYPE, 1,
|
|
"Pad length: %u", pad_len);
|
|
}
|
|
|
|
/*
|
|
* Compute length of data in PDU - subtract the trailer length
|
|
* and the pad length from the reported length.
|
|
*/
|
|
reported_length -= (pdu_len + pad_len);
|
|
|
|
/*
|
|
* XXX - if more than just Q.2931 uses SSCOP, we need to tell
|
|
* SSCOP what dissector to use here.
|
|
*/
|
|
if (reported_length != 0) {
|
|
/*
|
|
* We know that we have all of the payload, because we know we have
|
|
* at least 4 bytes of data after the payload, i.e. the SSCOP trailer.
|
|
* Therefore, we know that the captured length of the payload is
|
|
* equal to the length of the payload.
|
|
*/
|
|
next_tvb = tvb_new_subset(tvb, 0, reported_length, reported_length);
|
|
if (pdu_type == SSCOP_SD)
|
|
call_dissector(q2931_handle, next_tvb, pinfo, tree);
|
|
else
|
|
call_dissector(data_handle,next_tvb, pinfo, tree);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
void
|
|
proto_register_sscop(void)
|
|
{
|
|
static gint *ett[] = {
|
|
&ett_sscop,
|
|
};
|
|
proto_sscop = proto_register_protocol("SSCOP", "SSCOP", "sscop");
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
register_dissector("sscop", dissect_sscop, proto_sscop);
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_sscop(void)
|
|
{
|
|
/*
|
|
* Get handle for the Q.2931 dissector.
|
|
*/
|
|
q2931_handle = find_dissector("q2931");
|
|
data_handle = find_dissector("data");
|
|
}
|