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wireshark/packet-mdshdr.c

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/* packet-mdshdr.c
* Routines for dissection of Cisco MDS Switch Internal Header
* Copyright 2001, Dinesh G Dutt <ddutt@andiamo.com>
*
* $Id: packet-mdshdr.c,v 1.8 2003/10/30 02:06:12 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* Copied from WHATEVER_FILE_YOU_USED (where "WHATEVER_FILE_YOU_USED"
* is a dissector file; if you just copied this from README.developer,
* don't bother with the "Copied from" - you don't even need to put
* in a "Copied from" if you copied an existing dissector, especially
* if the bulk of the code in the new dissector is your code)
*
* 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 <stdlib.h>
#include <string.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include <glib.h>
#ifdef NEED_SNPRINTF_H
# include "snprintf.h"
#endif
#include <epan/value_string.h>
#include <etypes.h>
#include <epan/packet.h>
#include "prefs.h"
#define MDSHDR_VERSION_OFFSET 0
/* Mdshdr Control bits */
#define MDSHDR_CTL_IDXDIRECT 1
#define MDSHDR_CTL_IGNACLO 2
#define MDSHDR_CTL_DRP 4
/* OFFSETS OF FIELDS */
#define MDSHDR_VER_OFFSET 0
#define MDSHDR_SOF_OFFSET 1
#define MDSHDR_PKTLEN_OFFSET 2
#define MDSHDR_DIDX_OFFSET 5
#define MDSHDR_SIDX_OFFSET 6
#define MDSHDR_VSAN_OFFSET 13
/* Two size definitions are sufficient */
#define MDSHDR_SIZE_BYTE sizeof (gchar)
#define MDSHDR_SIZE_INT16 sizeof (guint16)
#define MDSHDR_SIZE_INT32 sizeof (guint32)
/* Other miscellaneous defines; can't rely on sizeof structs */
#define MDSHDR_MAX_VERSION 0
#define MDSHDR_HEADER_SIZE 16
#define MDSHDR_TRAILER_SIZE 6
/* SOF Encodings */
#define MDSHDR_SOFc1 0x1
#define MDSHDR_SOFi1 0x2
#define MDSHDR_SOFn1 0x3
#define MDSHDR_SOFi2 0x4
#define MDSHDR_SOFn2 0x5
#define MDSHDR_SOFi3 0x6
#define MDSHDR_SOFn3 0x7
#define MDSHDR_SOFf 0x8
#define MDSHDR_SOFc4 0x9
#define MDSHDR_SOFi4 0xa
#define MDSHDR_SOFn4 0xb
/* EOF Encodings */
#define MDSHDR_EOFt 0x1
#define MDSHDR_EOFdt 0x2
#define MDSHDR_EOFa 0x4
#define MDSHDR_EOFn 0x3
#define MDSHDR_EOFdti 0x6
#define MDSHDR_EOFni 0x7
#define MDSHDR_EOFrt 0xa
#define MDSHDR_EOFrti 0xe
#define MDSHDR_EOF_UNKNOWN 0xb
/* Initialize the protocol and registered fields */
static int proto_mdshdr = -1;
static int hf_mdshdr_sof = -1;
static int hf_mdshdr_pkt_len = -1;
static int hf_mdshdr_dstidx = -1;
static int hf_mdshdr_srcidx = -1;
static int hf_mdshdr_vsan = -1;
static int hf_mdshdr_eof = -1;
static int hf_mdshdr_span = -1;
static int hf_mdshdr_fccrc = -1;
/* Initialize the subtree pointers */
static gint ett_mdshdr = -1;
static gint ett_mdshdr_hdr = -1;
static gint ett_mdshdr_trlr = -1;
static dissector_handle_t data_handle, fc_dissector_handle;
static gboolean decode_if_zero_etype = TRUE;
static const value_string sof_vals[] = {
{MDSHDR_SOFc1, "SOFc1"},
{MDSHDR_SOFi1, "SOFi1"},
{MDSHDR_SOFn1, "SOFn1"},
{MDSHDR_SOFi2, "SOFi2"},
{MDSHDR_SOFn2, "SOFn2"},
{MDSHDR_SOFi3, "SOFi3"},
{MDSHDR_SOFn3, "SOFn3"},
{MDSHDR_SOFc4, "SOFc4"},
{MDSHDR_SOFi4, "SOFi4"},
{MDSHDR_SOFn4, "SOFn4"},
{MDSHDR_SOFf, "SOFf"},
{0, NULL},
};
static const value_string eof_vals[] = {
{MDSHDR_EOFt, "EOFt"},
{MDSHDR_EOFdt, "EOFdt"},
{MDSHDR_EOFa, "EOFa"},
{MDSHDR_EOFn, "EOFn"},
{MDSHDR_EOFdti, "EOFdti"},
{MDSHDR_EOFni, "EOFni"},
{MDSHDR_EOFrt, "EOFrt"},
{MDSHDR_EOFrti, "EOFrti"},
{MDSHDR_EOF_UNKNOWN, ""},
{0, NULL},
};
void proto_reg_handoff_mdshdr(void);
/* Code to actually dissect the packets */
static void
dissect_mdshdr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
/* Set up structures needed to add the protocol subtree and manage it */
proto_item *ti_main, *ti_hdr, *ti_trlr;
proto_tree *mdshdr_tree_main, *mdshdr_tree_hdr, *mdshdr_tree_trlr;
int offset = 0,
pktlen;
tvbuff_t *next_tvb;
guint8 sof, eof;
guint16 vsan;
guint8 span_id;
int trailer_start = 0;
/* Make entries in Protocol column and Info column on summary display */
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MDS Header");
if (check_col (pinfo->cinfo, COL_INFO))
col_clear (pinfo->cinfo, COL_INFO);
sof = tvb_get_guint8 (tvb, offset+MDSHDR_SOF_OFFSET) & 0x0F;
pktlen = tvb_get_ntohs (tvb, offset+MDSHDR_PKTLEN_OFFSET) & 0x1FFF;
vsan = tvb_get_ntohs (tvb, offset+MDSHDR_VSAN_OFFSET) & 0x0FFF;
span_id = (tvb_get_ntohs (tvb, offset+MDSHDR_VSAN_OFFSET) & 0xF000) >> 12;
/* The Mdshdr trailer is at the end of the frame */
if (tvb_bytes_exist (tvb, 0, MDSHDR_HEADER_SIZE + pktlen)) {
trailer_start = MDSHDR_HEADER_SIZE + pktlen - MDSHDR_TRAILER_SIZE;
eof = tvb_get_guint8 (tvb, trailer_start);
tvb_set_reported_length (tvb, MDSHDR_HEADER_SIZE+pktlen);
}
else {
eof = MDSHDR_EOF_UNKNOWN;
}
pinfo->src_idx = (tvb_get_ntohs (tvb, MDSHDR_SIDX_OFFSET) & 0x3FF);
pinfo->dst_idx = (tvb_get_ntohs (tvb, MDSHDR_DIDX_OFFSET) & 0xFFC) >> 6;
pinfo->vsan = vsan;
pinfo->sof_eof = 0;
if ((sof == MDSHDR_SOFi3) || (sof == MDSHDR_SOFi2) || (sof == MDSHDR_SOFi1)
|| (sof == MDSHDR_SOFi4)) {
pinfo->sof_eof = PINFO_SOF_FIRST_FRAME;
}
else if (sof == MDSHDR_SOFf) {
pinfo->sof_eof = PINFO_SOF_SOFF;
}
if (eof != MDSHDR_EOFn) {
pinfo->sof_eof |= PINFO_EOF_LAST_FRAME;
}
else if (eof != MDSHDR_EOFt) {
pinfo->sof_eof |= PINFO_EOF_INVALID;
}
/* In the interest of speed, if "tree" is NULL, don't do any work not
necessary to generate protocol tree items. */
if (tree) {
/* create display subtree for the protocol */
ti_main = proto_tree_add_protocol_format (tree, proto_mdshdr, tvb, 0,
MDSHDR_HEADER_SIZE+pktlen,
"MDS Header(%s/%s)",
val_to_str(sof, sof_vals, "Unknown(%u)"),
val_to_str(eof, eof_vals, "Unknown(%u)"));
mdshdr_tree_main = proto_item_add_subtree (ti_main, ett_mdshdr);
/* Add Header part as subtree first */
ti_hdr = proto_tree_add_text (mdshdr_tree_main, tvb, MDSHDR_VER_OFFSET,
MDSHDR_HEADER_SIZE, "MDS Header");
mdshdr_tree_hdr = proto_item_add_subtree (ti_hdr, ett_mdshdr_hdr);
proto_tree_add_item_hidden (mdshdr_tree_hdr, hf_mdshdr_sof, tvb, MDSHDR_SOF_OFFSET,
MDSHDR_SIZE_BYTE, 0);
proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_pkt_len, tvb, MDSHDR_PKTLEN_OFFSET,
MDSHDR_SIZE_INT16, 0);
proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_dstidx, tvb, MDSHDR_DIDX_OFFSET,
MDSHDR_SIZE_INT16, 0);
proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_srcidx, tvb, MDSHDR_SIDX_OFFSET,
MDSHDR_SIZE_INT16, 0);
proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_vsan, tvb, MDSHDR_VSAN_OFFSET,
MDSHDR_SIZE_INT16, 0);
proto_tree_add_uint_hidden(mdshdr_tree_hdr, hf_mdshdr_span,
tvb, MDSHDR_VSAN_OFFSET,
MDSHDR_SIZE_BYTE, span_id);
/* Add Mdshdr Trailer part */
if (tvb_bytes_exist (tvb, 0, MDSHDR_HEADER_SIZE+pktlen)) {
ti_trlr = proto_tree_add_text (mdshdr_tree_main, tvb, trailer_start,
MDSHDR_TRAILER_SIZE,
"MDS Trailer");
mdshdr_tree_trlr = proto_item_add_subtree (ti_trlr, ett_mdshdr_trlr);
proto_tree_add_item (mdshdr_tree_trlr, hf_mdshdr_eof, tvb,
trailer_start, MDSHDR_SIZE_BYTE, 0);
proto_tree_add_item (mdshdr_tree_trlr, hf_mdshdr_fccrc, tvb,
trailer_start+2, MDSHDR_SIZE_INT32, 0);
}
}
/* If this protocol has a sub-dissector call it here, see section 1.8 */
if (tvb_bytes_exist (tvb, 0, MDSHDR_HEADER_SIZE+pktlen)) {
next_tvb = tvb_new_subset (tvb, MDSHDR_HEADER_SIZE, pktlen, pktlen);
}
else {
next_tvb = tvb_new_subset (tvb, MDSHDR_HEADER_SIZE, -1, -1);
}
/* Call the Fibre Channel dissector */
if (fc_dissector_handle) {
call_dissector (fc_dissector_handle, next_tvb, pinfo, tree);
}
else {
call_dissector (data_handle, next_tvb, pinfo, tree);
}
}
/* Register the protocol with Ethereal. This format is require because a script
* is used to build the C function that calls all the protocol registration.
*/
void
proto_register_mdshdr(void)
{
/* Setup list of header fields See Section 1.6.1 for details*/
static hf_register_info hf[] = {
{ &hf_mdshdr_sof,
{"SOF", "mdshdr.sof", FT_UINT8, BASE_DEC, VALS(sof_vals), 0x0, "", HFILL}},
{ &hf_mdshdr_pkt_len,
{"Packet Len", "mdshdr.plen", FT_UINT16, BASE_DEC, NULL, 0x1FFF, "", HFILL}},
{ &hf_mdshdr_dstidx,
{"Dst Index", "mdshdr.dstidx", FT_UINT16, BASE_HEX, NULL, 0xFFC, "", HFILL}},
{ &hf_mdshdr_srcidx,
{"Src Index", "mdshdr.srcidx", FT_UINT16, BASE_HEX, NULL, 0x3FF, "", HFILL}},
{ &hf_mdshdr_vsan,
{"VSAN", "mdshdr.vsan", FT_UINT16, BASE_DEC, NULL, 0x0FFF, "", HFILL}},
{ &hf_mdshdr_eof,
{"EOF", "mdshdr.eof", FT_UINT8, BASE_DEC, VALS(eof_vals), 0x0, "", HFILL}},
{ &hf_mdshdr_span,
{"SPAN Frame", "mdshdr.span", FT_UINT8, BASE_DEC, NULL, 0x0,
"", HFILL}},
{ &hf_mdshdr_fccrc,
{"CRC", "mdshdr.crc", FT_UINT32, BASE_HEX, NULL, 0x0, "", HFILL}},
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_mdshdr,
&ett_mdshdr_hdr,
&ett_mdshdr_trlr
};
module_t *mdshdr_module;
/* Register the protocol name and description */
proto_mdshdr = proto_register_protocol("MDS Header", "MDS Header", "mdshdr");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_mdshdr, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
mdshdr_module = prefs_register_protocol (proto_mdshdr, proto_reg_handoff_mdshdr);
prefs_register_bool_preference (mdshdr_module, "decode_if_etype_zero",
"Decode as MDS Header If Ethertype == 0",
"A frame is considered for decoding as MDSHDR if either "
"ethertype is 0xFCFC or zero. Turn this flag off if you "
"you don't want ethertype zero to be decoded as MDSHDR. "
"This might be useful to avoid problems with test frames.",
&decode_if_zero_etype);
}
/* If this dissector uses sub-dissector registration add a registration routine.
This format is required because a script is used to find these routines and
create the code that calls these routines.
*/
void
proto_reg_handoff_mdshdr(void)
{
static dissector_handle_t mdshdr_handle;
static gboolean registered_for_zero_etype = FALSE;
static gboolean mdshdr_prefs_initialized = FALSE;
if (!mdshdr_prefs_initialized) {
/*
* This is the first time this has been called (i.e.,
* Ethereal/Tethereal is starting up), so create a handle for
* the MDS Header dissector, register the dissector for
* ethertype ETHERTYPE_FCFT, and fetch the data and Fibre
* Channel handles.
*/
mdshdr_handle = create_dissector_handle (dissect_mdshdr, proto_mdshdr);
dissector_add ("ethertype", ETHERTYPE_FCFT, mdshdr_handle);
data_handle = find_dissector ("data");
fc_dissector_handle = find_dissector ("fc");
mdshdr_prefs_initialized = TRUE;
}
/*
* Only register the dissector for ethertype 0 if the preference
* is set to do so.
*/
if (decode_if_zero_etype) {
/*
* The preference to register for ethertype ETHERTYPE_UNK (0)
* is set; if we're not registered for ethertype ETHERTYPE_UNK,
* do so.
*/
if (!registered_for_zero_etype) {
dissector_add ("ethertype", ETHERTYPE_UNK, mdshdr_handle);
registered_for_zero_etype = TRUE;
}
} else {
/*
* The preference to register for ethertype ETHERTYPE_UNK (0)
* is not set; if we're registered for ethertype ETHERTYPE_UNK,
* undo that registration.
*/
if (registered_for_zero_etype) {
dissector_delete ("ethertype", ETHERTYPE_UNK, mdshdr_handle);
registered_for_zero_etype = FALSE;
}
}
}
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