Ethereal-dev: [ethereal-dev] New dissector with tvbuffs, packet-cops
Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.
From: Heikki Vatiainen <hessu@xxxxxxxxx>
Date: Wed, 07 Jun 2000 22:44:23 +0300
Here is a preliminary dissector for RFC 2748, The COPS (Common
Open Policy Service) Protocol. The dissector is done using tvbuffs
and tries to use the new tvbuff related calls as I understood they
should be used. I am planning to add code to dissect the COPS object
contents later, but maybe this could already be used as an example of
programming with tvbuffs.
For the curious, the inside #if 0 hack near the start of dissect_cops is
waiting for the new dissector prototype
void/gboolean dissector(tvbuff_t *, packet_info* , proto_tree*);
to be employed. Before that happens, the code in the #else part
"emulates" the new prototype.
In case someone wants to see if the dissector works, I'm enclosing
a slightly modified capture file. The Message Integrity Object in
the very first COPS message has been modified so that the object
length is now 25 instead of 24. This causes an exception handled by
tvbuffs.
/* packet-cops.c
* Routines for the COPS (Common Open Policy Service) protocol dissection
* RFC2748
*
* Copyright 2000, Heikki Vatiainen <hessu@xxxxxxxxx>
*
* $Id$
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@xxxxxxxx>
* Copyright 1998 Gerald Combs
*
*
* 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>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include <string.h>
#include <glib.h>
#include "packet.h"
#include "packet-cops.h"
/* Initialize the protocol and registered fields */
static gint proto_cops = -1;
static gint hf_cops_ver_flags = -1;
static gint hf_cops_version = -1;
static gint hf_cops_flags = -1;
static gint hf_cops_op_code = -1;
static gint hf_cops_client_type = -1;
static gint hf_cops_msg_len = -1;
static gint hf_cops_obj_len = -1;
static gint hf_cops_obj_c_num = -1;
static gint hf_cops_obj_c_type = -1;
/* Initialize the subtree pointers */
static gint ett_cops = -1;
static gint ett_cops_ver_flags = -1;
static gint ett_cops_obj = -1;
static int dissect_cops_object(tvbuff_t *tvb, guint32 offset, proto_tree *tree);
/* Code to actually dissect the packets */
#if 0
static void dissect_cops(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
guint8 op_code;
#else
static void dissect_cops(const u_char *pd, int o, frame_data *fd, proto_tree *tree)
{
tvbuff_t *real_tvb, *tvb;
packet_info *pinfo = π
guint8 op_code;
real_tvb = tvb_new_real_data(pd, fd->cap_len, fd->pkt_len);
tvb = tvb_new_subset(real_tvb, o, fd->cap_len - o, fd->pkt_len - o);
#endif
pinfo->current_proto = "COPS";
if (check_col(pinfo->fd, COL_PROTOCOL))
col_add_str(pinfo->fd, COL_PROTOCOL, "COPS");
op_code = tvb_get_guint8(tvb, 1);
if (check_col(pinfo->fd, COL_INFO))
col_add_fstr(pinfo->fd, COL_INFO, "COPS %s",
val_to_str(op_code, cops_op_code_vals, "Unknown Op Code"));
if (tree) {
proto_item *ti, *tv;
proto_tree *cops_tree, *ver_flags_tree;
guint32 offset, msg_len, carbage;
guint8 ver_flags;
offset = 0;
ti = proto_tree_add_item(tree, proto_cops, tvb, offset, tvb_length(tvb), FALSE);
cops_tree = proto_item_add_subtree(ti, ett_cops);
/* Version and flags share the same byte, put them in a subtree */
ver_flags = tvb_get_guint8(tvb, offset);
tv = proto_tree_add_uint_format(cops_tree, hf_cops_ver_flags, tvb, offset, 1,
ver_flags, "Version: %u, Flags: %s",
hi_nibble(ver_flags),
val_to_str(lo_nibble(ver_flags), cops_flags_vals, "Unknown"));
ver_flags_tree = proto_item_add_subtree(tv, ett_cops_ver_flags);
proto_tree_add_uint(ver_flags_tree, hf_cops_version, tvb, offset, 1, ver_flags);
proto_tree_add_uint(ver_flags_tree, hf_cops_flags, tvb, offset, 1, ver_flags);
offset++;
proto_tree_add_uint(cops_tree, hf_cops_op_code, tvb, offset, 1, tvb_get_guint8(tvb, offset));
offset ++;
proto_tree_add_uint(cops_tree, hf_cops_client_type, tvb, offset, 2, tvb_get_ntohs(tvb, offset));
offset += 2;
msg_len = tvb_get_ntohl(tvb, offset);
proto_tree_add_uint(cops_tree, hf_cops_msg_len, tvb, offset, 4, tvb_get_ntohl(tvb, offset));
offset += 4;
while (msg_len >= COPS_OBJECT_HDR_SIZE) {
int consumed;
consumed = dissect_cops_object(tvb, offset, cops_tree);
if (consumed == 0)
break;
msg_len -= consumed;
offset += consumed;
}
carbage = tvb_length_remaining(tvb, offset);
if (carbage != 0)
proto_tree_add_text(cops_tree, tvb, offset, carbage,
"Trailing carbage: %u byte%s", carbage,
plurality(carbage, "", "s"));
}
return;
}
static int dissect_cops_object(tvbuff_t *tvb, guint32 offset, proto_tree *tree)
{
guint16 object_len, contents_len;
guint8 c_num, c_type;
proto_item *ti;
proto_tree *obj_tree;
if (tvb_length_remaining(tvb, offset) < COPS_OBJECT_HDR_SIZE)
return 0;
object_len = tvb_get_ntohs(tvb, offset);
c_num = tvb_get_guint8(tvb, offset + 2);
c_type = tvb_get_guint8(tvb, offset + 3);
ti = proto_tree_add_uint_format(tree, hf_cops_obj_c_num, tvb, offset, object_len, c_num,
"Object Type: %s", val_to_str(c_num, cops_c_num_vals, "Unknown"));
obj_tree = proto_item_add_subtree(ti, ett_cops_obj);
proto_tree_add_uint(obj_tree, hf_cops_obj_len, tvb, offset, 2, tvb_get_ntohs(tvb, offset));
offset += 2;
proto_tree_add_uint(obj_tree, hf_cops_obj_c_num, tvb, offset, 1, tvb_get_guint8(tvb, offset));
offset++;
proto_tree_add_uint(obj_tree, hf_cops_obj_c_type, tvb, offset, 1, tvb_get_guint8(tvb, offset));
offset++;
contents_len = object_len - COPS_OBJECT_HDR_SIZE;
proto_tree_add_text(obj_tree, tvb, offset, contents_len,
"Object contents: %u bytes", contents_len);
/* Pad to 32bit boundary */
if (object_len % sizeof (uint32_t))
object_len += (sizeof (uint32_t) - object_len % sizeof (uint32_t));
return object_len;
}
/* Register the protocol with Ethereal */
void proto_register_cops(void)
{
/* Setup list of header fields */
static hf_register_info hf[] = {
{ &hf_cops_ver_flags,
{ "Version and Flags", "cops.ver_flags",
FT_UINT8, BASE_HEX, NULL, 0x0,
"Version and Flags in COPS Common Header" }
},
{ &hf_cops_version,
{ "Version", "cops.version",
FT_UINT8, BASE_DEC, NULL, 0xF0,
"Version in COPS Common Header" }
},
{ &hf_cops_flags,
{ "Flags", "cops.flags",
FT_UINT8, BASE_HEX, VALS(cops_flags_vals), 0x0F,
"Flags in COPS Common Header" }
},
{ &hf_cops_op_code,
{ "Op Code", "cops.op_code",
FT_UINT8, BASE_DEC, VALS(cops_op_code_vals), 0x0,
"Op Code in COPS Common Header" }
},
{ &hf_cops_client_type,
{ "Client Type", "cops.client_type",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Client Type in COPS Common Header" }
},
{ &hf_cops_msg_len,
{ "Message Length", "cops.msg_len",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Message Length in COPS Common Header" }
},
{ &hf_cops_obj_len,
{ "Object Length", "cops.obj.len",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Object Length in COPS Object Header" }
},
{ &hf_cops_obj_c_num,
{ "C-Num", "cops.obj.c_num",
FT_UINT8, BASE_DEC, VALS(cops_c_num_vals), 0x0,
"C-Num in COPS Object Header" }
},
{ &hf_cops_obj_c_type,
{ "C-Type", "cops.obj.c_type",
FT_UINT8, BASE_DEC, NULL, 0x0,
"C-Type in COPS Object Header" }
},
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_cops,
&ett_cops_ver_flags,
&ett_cops_obj,
};
/* Register the protocol name and description */
proto_cops = proto_register_protocol("Common Open Policy Service", "cops");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_cops, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
};
void
proto_reg_handoff_cops(void)
{
dissector_add("tcp.port", TCP_PORT_COPS, dissect_cops);
}
/* packet-cops.h
*
* $Id$
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@xxxxxxxx>
* Copyright 1998 Gerald Combs
*
*
* 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.
*/
#define TCP_PORT_COPS 3288
#define COPS_OBJECT_HDR_SIZE 4
static const value_string cops_flags_vals[] = {
{ 0x00, "None" },
{ 0x01, "Solicited Message Flag Bit" },
{ 0, NULL },
};
/* The different COPS message types */
enum cops_op_code {
COPS_NO_MSG, /* Not a COPS Message type */
COPS_MSG_REQ, /* Request (REQ) */
COPS_MSG_DEC, /* Decision (DEC) */
COPS_MSG_RPT, /* Report State (RPT) */
COPS_MSG_DRQ, /* Delete Request State (DRQ) */
COPS_MSG_SSQ, /* Synchronize State Req (SSQ) */
COPS_MSG_OPN, /* Client-Open (OPN) */
COPS_MSG_CAT, /* Client-Accept (CAT) */
COPS_MSG_CC, /* Client-Close (CC) */
COPS_MSG_KA, /* Keep-Alive (KA) */
COPS_MSG_SSC, /* Synchronize Complete (SSC) */
COPS_LAST_OP_CODE /* For error checking */
};
static const value_string cops_op_code_vals[] = {
{ COPS_MSG_REQ, "Request (REQ)" },
{ COPS_MSG_DEC, "Decision (DEC)" },
{ COPS_MSG_RPT, "Report State (RPT)" },
{ COPS_MSG_DRQ, "Delete Request State (DRQ)" },
{ COPS_MSG_SSQ, "Synchronize State Req (SSQ)" },
{ COPS_MSG_OPN, "Client-Open (OPN)" },
{ COPS_MSG_CAT, "Client-Accept (CAT)" },
{ COPS_MSG_CC, "Client-Close (CC)" },
{ COPS_MSG_KA, "Keep-Alive (KA)" },
{ COPS_MSG_SSC, "Synchronize Complete (SSC)" },
{ 0, NULL },
};
/* The different objects in COPS messages */
enum cops_c_num {
COPS_NO_OBJECT, /* Not a COPS Object type */
COPS_OBJ_HANDLE, /* Handle Object (Handle) */
COPS_OBJ_CONTEXT, /* Context Object (Context) */
COPS_OBJ_IN_INT, /* In-Interface Object (IN-Int) */
COPS_OBJ_OUT_INT, /* Out-Interface Object (OUT-Int) */
COPS_OBJ_REASON, /* Reason Object (Reason) */
COPS_OBJ_DECISION, /* Decision Object (Decision) */
COPS_OBJ_LPDPDECISION, /* LPDP Decision Object (LPDPDecision) */
COPS_OBJ_ERROR, /* Error Object (Error) */
COPS_OBJ_CLIENTSI, /* Client Specific Information Object (ClientSI) */
COPS_OBJ_KATIMER, /* Keep-Alive Timer Object (KATimer) */
COPS_OBJ_PEPID, /* PEP Identification Object (PEPID) */
COPS_OBJ_REPORT_TYPE, /* Report-Type Object (Report-Type) */
COPS_OBJ_PDPREDIRADDR, /* PDP Redirect Address Object (PDPRedirAddr) */
COPS_OBJ_LASTPDPADDR, /* Last PDP Address (LastPDPaddr) */
COPS_OBJ_ACCTTIMER, /* Accounting Timer Object (AcctTimer) */
COPS_OBJ_INTEGRITY, /* Message Integrity Object (Integrity) */
COPS_LAST_C_NUM /* For error checking */
};
static const value_string cops_c_num_vals[] = {
{ COPS_OBJ_HANDLE, " Handle Object (Handle)" },
{ COPS_OBJ_CONTEXT, " Context Object (Context)" },
{ COPS_OBJ_IN_INT, " In-Interface Object (IN-Int)" },
{ COPS_OBJ_OUT_INT, " Out-Interface Object (OUT-Int)" },
{ COPS_OBJ_REASON, " Reason Object (Reason)" },
{ COPS_OBJ_DECISION, " Decision Object (Decision)" },
{ COPS_OBJ_LPDPDECISION, " LPDP Decision Object (LPDPDecision)" },
{ COPS_OBJ_ERROR, " Error Object (Error)" },
{ COPS_OBJ_CLIENTSI, " Client Specific Information Object (ClientSI)" },
{ COPS_OBJ_KATIMER, " Keep-Alive Timer Object (KATimer)" },
{ COPS_OBJ_PEPID, " PEP Identification Object (PEPID)" },
{ COPS_OBJ_REPORT_TYPE, " Report-Type Object (Report-Type)" },
{ COPS_OBJ_PDPREDIRADDR, " PDP Redirect Address Object (PDPRedirAddr)" },
{ COPS_OBJ_LASTPDPADDR, " Last PDP Address (LastPDPaddr)" },
{ COPS_OBJ_ACCTTIMER, " Accounting Timer Object (AcctTimer)" },
{ COPS_OBJ_INTEGRITY, " Message Integrity Object (Integrity)" },
{ 0, NULL },
};
Index: Makefile.am
===================================================================
RCS file: /cvsroot/ethereal/Makefile.am,v
retrieving revision 1.202
diff -u -r1.202 Makefile.am
--- Makefile.am 2000/05/30 03:35:50 1.202
+++ Makefile.am 2000/06/07 19:12:49
@@ -48,6 +48,7 @@
packet-cgmp.c \
packet-clip.c \
packet-clnp.c \
+ packet-cops.c \
packet-data.c \
packet-ddtp.c \
packet-dns.c \
@@ -170,6 +171,7 @@
packet-cgmp.h \
packet-clip.h \
packet-clnp.h \
+ packet-cops.h \
packet-ddtp.h \
packet-dns.h \
packet-esis.h \
Index: Makefile.nmake
===================================================================
RCS file: /cvsroot/ethereal/Makefile.nmake,v
retrieving revision 1.40
diff -u -r1.40 Makefile.nmake
--- Makefile.nmake 2000/05/29 20:11:23 1.40
+++ Makefile.nmake 2000/06/07 19:12:49
@@ -35,6 +35,7 @@
packet-cgmp.c \
packet-clip.c \
packet-clnp.c \
+ packet-cops.c \
packet-data.c \
packet-ddtp.c \
packet-dns.c \
Attachment:
cops2.cap.gz
Description: cops2.cap.gz
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