* Routines for SSCOP (Q.2110, Q.SAAL) frame disassembly
* Guy Harris <guy@alum.mit.edu>
*
- * $Id: packet-sscop.c,v 1.4 1999/11/23 07:19:14 guy Exp $
+ * $Id: packet-sscop.c,v 1.19 2002/08/02 23:36:03 jmayer Exp $
*
* Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
* Copyright 1998
*
*
# include "config.h"
#endif
-#ifdef HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-
#include <stdio.h>
#include <glib.h>
#include <string.h>
-#include "packet.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
*
/*
* PDU type.
*/
-#define SSCOP_PDU_TYPE (pi.len - 4) /* single byte */
+#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 (pi.len - 5) /* One byte */
-#define SSCOP_N_MR (pi.len - 4) /* lower 3 bytes thereof */
+#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 (pi.len - 8) /* lower 3 bytes thereof */
-#define SSCOP_N_S (pi.len - 4) /* lower 3 bytes thereof */
+#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 (pi.len - 12) /* lower 3 bytes thereof */
-#define SSCOP_SS_N_MR (pi.len - 8) /* lower 3 bytes thereof */
-#define SSCOP_SS_N_R (pi.len - 4) /* lower 3 bytes thereof */
+#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 */
-void
-dissect_sscop(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
+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;
-
- /*
- * The SSCOP "header" is a trailer, and the PDU type is in the
- * last-minus-3 byte of the frame; if the captured length is less
- * than the actual length by 3 or more bytes, give up, as we don't
- * have the PDU type.
- */
- if ((pi.len - pi.captured_len) >= 3) {
- dissect_data(pd, offset, fd, tree);
- return;
- }
- pdu_type = pd[SSCOP_PDU_TYPE] & SSCOP_TYPE_MASK;
- if (check_col(fd, COL_PROTOCOL))
- col_add_str(fd, COL_PROTOCOL, "SSCOP");
- if (check_col(fd, COL_INFO))
- col_add_str(fd, COL_INFO, val_to_str(pdu_type, sscop_type_vals,
+ 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)"));
/*
switch (pdu_type) {
case SSCOP_SD:
- pad_len = (pd[SSCOP_PDU_TYPE] >> 6) & 0x03;
+ pad_len = (sscop_pdu_type >> 6) & 0x03;
pdu_len = 4;
break;
#if 0
case SSCOP_SDP:
#endif
- pad_len = (pd[SSCOP_PDU_TYPE] >> 6) & 0x03;
+ pad_len = (sscop_pdu_type >> 6) & 0x03;
pdu_len = 8;
break;
case SSCOP_UD:
- pad_len = (pd[SSCOP_PDU_TYPE] >> 6) & 0x03;
+ pad_len = (sscop_pdu_type >> 6) & 0x03;
pdu_len = 4;
break;
default:
pad_len = 0;
- pdu_len = pi.len; /* No payload, just SSCOP */
+ pdu_len = reported_length; /* No payload, just SSCOP */
break;
}
if (tree) {
- ti = proto_tree_add_item_format(tree, proto_sscop, pi.len - pdu_len,
- pdu_len, NULL, "SSCOP");
+ 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, SSCOP_PDU_TYPE, 1,
+ 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)"));
case SSCOP_BGN:
case SSCOP_RS:
case SSCOP_ER:
- proto_tree_add_text(sscop_tree, SSCOP_N_SQ, 1,
- "N(SQ): %u", pd[SSCOP_N_SQ]);
- proto_tree_add_text(sscop_tree, SSCOP_N_MR + 1, 3,
- "N(MR): %u", pntohl(&pd[SSCOP_N_MR]) & 0xFFFFFF);
+ 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, SSCOP_PDU_TYPE, 1,
- "Source: %s", (pd[SSCOP_PDU_TYPE] & SSCOP_S) ? "SSCOP" : "User");
+ 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, SSCOP_N_MR + 1, 3,
- "N(MR): %u", pntohl(&pd[SSCOP_N_MR]) & 0xFFFFFF);
+ 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, SSCOP_N_MR + 3, 3,
- "N(MR): %u", pntohl(&pd[SSCOP_N_MR]) & 0xFFFFFF);
+ 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, SSCOP_N_S + 1, 3,
- "N(S): %u", pntohl(&pd[SSCOP_N_S]) & 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;
#if 0
case SSCOP_SDP:
#endif
case SSCOP_POLL:
- proto_tree_add_text(sscop_tree, SSCOP_N_PS + 1, 3,
- "N(PS): %u", pntohl(&pd[SSCOP_N_PS]) & 0xFFFFFF);
- proto_tree_add_text(sscop_tree, SSCOP_N_S + 1, 3,
- "N(S): %u", pntohl(&pd[SSCOP_N_S]) & 0xFFFFFF);
+ 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, SSCOP_SS_N_PS + 1, 3,
- "N(PS): %u", pntohl(&pd[SSCOP_SS_N_PS]) & 0xFFFFFF);
- proto_tree_add_text(sscop_tree, SSCOP_SS_N_MR + 1, 3,
- "N(MR): %u", pntohl(&pd[SSCOP_SS_N_MR]) & 0xFFFFFF);
- proto_tree_add_text(sscop_tree, SSCOP_SS_N_R + 1, 3,
- "N(R): %u", pntohl(&pd[SSCOP_SS_N_R]) & 0xFFFFFF);
+ 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, SSCOP_SS_N_MR + 1, 3,
- "N(MR): %u", pntohl(&pd[SSCOP_SS_N_MR]) & 0xFFFFFF);
- proto_tree_add_text(sscop_tree, SSCOP_SS_N_R + 1, 3,
- "N(R): %u", pntohl(&pd[SSCOP_SS_N_R]) & 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_SDP:
#endif
if (tree) {
- proto_tree_add_text(sscop_tree, SSCOP_PDU_TYPE, 1,
+ 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.
+ * and the pad length from the reported length.
*/
- pi.len -= (pdu_len + pad_len);
- if (pi.len < pi.captured_len)
- pi.captured_len = pi.len;
+ 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 (pi.len != 0) {
+ 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)
- dissect_q2931(pd, offset, fd, tree);
+ call_dissector(q2931_handle, next_tvb, pinfo, tree);
else
- dissect_data(pd, offset, fd, tree);
+ 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");
- proto_register_subtree_array(ett, array_length(ett));
+ 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");
}