wireshark/epan/dissectors/packet-isis-clv.c
Michael Mann 89786cc8c7 Overhaul the ISIS dissectors
1. Make real dissectors and call dissector_try_uint_new for each "isis.type"
2. Use make_register script for dissector initialization
3. Replace isis_dissect_unknown() with real expert info
4. Use convert_proto_tree_add_text.pl to make many more filterable items and gets some files off of the checkAPIs.pl naughty list.
5. Remove (now unnecessary) dissector specific header files
6. Do some reordering of functions to eliminate the need for function declarations.

Additional whitespace formatting and modelines should probably be applied to all of these dissectors.

Used capture files from bug 5354 (https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=5354) and bug 1792 (https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=1792) for fuzztesting.

svn path=/trunk/; revision=54367
2013-12-22 18:18:12 +00:00

583 lines
15 KiB
C

/* packet-isis-clv.c
* Common CLV decode routines.
*
* $Id$
* Stuart Stanley <stuarts@mxmail.net>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <glib.h>
#include <epan/packet.h>
#include <epan/expert.h>
#include "packet-osi.h"
#include "packet-isis.h"
#include "packet-isis-clv.h"
#include <epan/nlpid.h>
/*
* Name: isis_dissect_area_address_clv()
*
* Description:
* Take an area address CLV and display it pieces. An area address
* CLV is n, x byte hex strings.
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_area_address_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb,
expert_field* expert, int offset, int length)
{
int arealen,area_idx;
while ( length > 0 ) {
arealen = tvb_get_guint8(tvb, offset);
length--;
if (length<=0) {
proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1,
"short address (no length for payload)");
return;
}
if ( arealen > length) {
proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1,
"short address, packet says %d, we have %d left",
arealen, length );
return;
}
if ( tree ) {
proto_item *ti;
/*
* Throw an exception rather than putting in a
* partial address.
*/
tvb_ensure_bytes_exist ( tvb, offset, arealen + 1 );
ti = proto_tree_add_text ( tree, tvb, offset, arealen + 1,
"Area address (%d): ", arealen );
/*
* Lets turn the area address into "standard"
* xx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx format string.
* this is a private routine as the print_nsap_net in
* epan/osi_utils.c is incomplete and we need only
* a subset - actually some nice placing of dots ....
*/
for (area_idx = 0; area_idx < arealen; area_idx++) {
proto_item_append_text(ti, "%02x",
tvb_get_guint8(tvb, offset+area_idx+1));
if (((area_idx & 1) == 0) &&
(area_idx + 1 < arealen)) {
proto_item_append_text(ti, ".");
}
}
}
offset += arealen + 1;
length -= arealen; /* length already adjusted for len fld*/
}
}
/*
* Name: isis_dissect_authentication_clv()
*
* Description:
* Take apart the CLV that hold authentication information. This
* is currently 1 octet auth type.
* the two defined authentication types
* are 1 for a clear text password and
* 54 for a HMAC-MD5 digest
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_authentication_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb,
expert_field* auth_expert, int offset, int length)
{
guchar pw_type;
int auth_unsupported;
proto_item *ti;
if ( length <= 0 ) {
return;
}
pw_type = tvb_get_guint8(tvb, offset);
offset += 1;
length--;
auth_unsupported = FALSE;
switch (pw_type) {
case 1:
ti = proto_tree_add_text ( tree, tvb, offset - 1, length + 1,
"clear text (1), password (length %d) = ", length);
if ( length > 0 ) {
proto_item_append_text(ti, "%s",
tvb_format_text(tvb, offset, length));
} else {
proto_item_append_text(ti, "no clear-text password found!!!");
}
break;
case 54:
ti = proto_tree_add_text ( tree, tvb, offset - 1, length + 1,
"hmac-md5 (54), password (length %d) = ", length);
if ( length == 16 ) {
proto_item_append_text(ti, "0x%02x", tvb_get_guint8(tvb, offset));
offset += 1;
length--;
while (length > 0) {
proto_item_append_text(ti, "%02x", tvb_get_guint8(tvb, offset));
offset += 1;
length--;
}
} else {
proto_item_append_text(ti,
"illegal hmac-md5 digest format (must be 16 bytes)");
}
break;
default:
proto_tree_add_text ( tree, tvb, offset - 1, length + 1,
"type 0x%02x (0x%02x): ", pw_type, length );
auth_unsupported=TRUE;
break;
}
if ( auth_unsupported ) {
proto_tree_add_expert(tree, pinfo, auth_expert, tvb, offset, -1);
}
}
/*
* Name: isis_ip_authentication_clv()
*
* Description:
* dump the IP authentication information found in TLV 133
* the CLV is standardized in rf1195, however all major
* implementations use TLV #10
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_ip_authentication_clv(tvbuff_t *tvb, proto_tree *tree, int offset,
int length)
{
if ( !tree ) return; /* nothing to do! */
if ( length != 0 ) {
proto_tree_add_text ( tree, tvb, offset, length,
"IP Authentication: %.*s", length,
tvb_get_string(wmem_packet_scope(), tvb, offset, length) );
}
}
/*
* Name: isis_dissect_hostname_clv()
*
* Description:
* dump the hostname information found in TLV 137
* pls note that the hostname is not null terminated
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
* int : tree id to use for proto tree.
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_hostname_clv(tvbuff_t *tvb, proto_tree *tree, int offset,
int length, int tree_id)
{
if ( !tree ) return; /* nothing to do! */
if ( length == 0 ) {
proto_tree_add_text ( tree, tvb, offset, length,
"Hostname: --none--" );
} else {
const char* value = tvb_get_string(wmem_packet_scope(), tvb, offset, length);
proto_tree_add_string_format ( tree, tree_id,
tvb, offset, length,
value, "Hostname: %.*s", length, value);
}
}
void
isis_dissect_mt_clv(tvbuff_t *tvb, proto_tree *tree, int offset, int length,
int tree_id)
{
guint16 mt_block;
const char *mt_desc;
while (length>0) {
/* length can only be a multiple of 2, otherwise there is
something broken -> so decode down until length is 1 */
if (length!=1) {
/* fetch two bytes */
mt_block=tvb_get_ntohs(tvb, offset);
/* mask out the lower 12 bits */
switch(mt_block&0x0fff) {
case 0:
mt_desc="IPv4 unicast";
break;
case 1:
mt_desc="In-Band Management";
break;
case 2:
mt_desc="IPv6 unicast";
break;
case 3:
mt_desc="Multicast";
break;
case 4095:
mt_desc="Development, Experimental or Proprietary";
break;
default:
mt_desc="Reserved for IETF Consensus";
break;
}
proto_tree_add_uint_format ( tree, tree_id, tvb, offset, 2,
mt_block,
"%s Topology (0x%03x), %ssubTLVs present%s",
mt_desc,
mt_block&0xfff,
(mt_block&0x8000) ? "" : "no ",
(mt_block&0x4000) ? ", ATT bit set" : "" );
} else {
proto_tree_add_text ( tree, tvb, offset, 1,
"malformed MT-ID");
break;
}
length -= 2;
offset += 2;
}
}
/*
* Name: isis_dissect_ip_int_clv()
*
* Description:
* Take apart the CLV that lists all the IP interfaces. The
* meaning of which is slightly different for the different base packet
* types, but the display is not different. What we have is n ip
* addresses, plain and simple.
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
* int : tree id to use for proto tree.
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_ip_int_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert,
int offset, int length, int tree_id)
{
if ( length <= 0 ) {
return;
}
while ( length > 0 ) {
if ( length < 4 ) {
proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1,
"Short IP interface address (%d vs 4)",length );
return;
}
if ( tree ) {
proto_tree_add_item(tree, tree_id, tvb, offset, 4, ENC_BIG_ENDIAN);
}
offset += 4;
length -= 4;
}
}
/*
* Name: isis_dissect_ipv6_int_clv()
*
* Description:
* Take apart the CLV that lists all the IPv6 interfaces. The
* meaning of which is slightly different for the different base packet
* types, but the display is not different. What we have is n ip
* addresses, plain and simple.
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
* int : tree id to use for proto tree.
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_ipv6_int_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert,
int offset, int length, int tree_id)
{
guint8 addr [16];
if ( length <= 0 ) {
return;
}
while ( length > 0 ) {
if ( length < 16 ) {
proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1,
"Short IPv6 interface address (%d vs 16)",length );
return;
}
tvb_memcpy(tvb, addr, offset, sizeof(addr));
if ( tree ) {
proto_tree_add_ipv6(tree, tree_id, tvb, offset, 16, addr);
}
offset += 16;
length -= 16;
}
}
/*
* Name: isis_dissect_te_router_id_clv()
*
* Description:
* Display the Traffic Engineering Router ID TLV #134.
* This TLV is like the IP Interface TLV, except that
* only _one_ IP address is present
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
* int : tree id to use for proto tree.
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_te_router_id_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert,
int offset, int length, int tree_id)
{
if ( length <= 0 ) {
return;
}
if ( length != 4 ) {
proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1,
"malformed Traffic Engineering Router ID (%d vs 4)",length );
return;
}
proto_tree_add_item(tree, tree_id, tvb, offset, 4, ENC_BIG_ENDIAN);
}
/*
* Name: isis_dissect_nlpid_clv()
*
* Description:
* Take apart a NLPID packet and display it. The NLPID (for intergrated
* ISIS, contains n network layer protocol IDs that the box supports.
* We max out at 256 entries.
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* int : length of clv we are decoding
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
#define TRUNCATED_TEXT " [truncated]"
void
isis_dissect_nlpid_clv(tvbuff_t *tvb, proto_tree *tree, int offset, int length)
{
gboolean first;
proto_item *ti;
if ( !tree ) return; /* nothing to do! */
/*
* Throw an exception rather than putting in a
* partial address.
*/
tvb_ensure_bytes_exist ( tvb, offset, length );
if (length <= 0) {
proto_tree_add_text (tree, tvb, offset, length,
"NLPID(s): --none--");
} else {
first = TRUE;
ti = proto_tree_add_text (tree, tvb, offset, length,
"NLPID(s): ");
while (length-- > 0 ) {
if (!first) {
proto_item_append_text(ti, ", ");
}
proto_item_append_text(ti, "%s (0x%02x)",
/* NLPID_IEEE_8021AQ conflicts with NLPID_SNDCF.
* In this context, we want the former.
*/
(tvb_get_guint8(tvb, offset) == NLPID_IEEE_8021AQ
? "IEEE 802.1aq (SPB)"
: val_to_str_const(tvb_get_guint8(tvb, offset), nlpid_vals, "Unknown")),
tvb_get_guint8(tvb, offset));
offset++;
first = FALSE;
}
}
}
/*
* Name: isis_dissect_clvs()
*
* Description:
* Dispatch routine to shred all the CLVs in a packet. We just
* walk through the clv entries in the packet. For each one, we
* search the passed in valid clv's for this protocol (opts) for
* a matching code. If found, we add to the display tree and
* then call the dissector. If it is not, we just post an
* "unknown" clv entry using the passed in unknown clv tree id.
*
* Input:
* tvbuff_t * : tvbuffer for packet data
* proto_tree * : protocol display tree to fill out. May be NULL
* int : offset into packet data where we are.
* isis_clv_handle_t * : NULL dissector terminated array of codes
* and handlers (along with tree text and tree id's).
* int : length of CLV area.
* int : length of IDs in packet.
* int : unknown clv tree id
*
* Output:
* void, but we will add to proto tree if !NULL.
*/
void
isis_dissect_clvs(tvbuff_t *tvb, packet_info* pinfo, proto_tree *tree, int offset,
const isis_clv_handle_t *opts, expert_field* expert_short_len, int len, int id_length,
int unknown_tree_id _U_)
{
guint8 code;
guint8 length;
int q;
proto_item *ti;
proto_tree *clv_tree;
while ( len > 0 ) {
code = tvb_get_guint8(tvb, offset);
offset += 1;
len -= 1;
if (len == 0)
break;
length = tvb_get_guint8(tvb, offset);
offset += 1;
len -= 1;
if (len == 0)
break;
if ( len < length ) {
proto_tree_add_expert_format(tree, pinfo, expert_short_len, tvb, offset, -1,
"Short CLV header (%d vs %d)",
length, len );
return;
}
q = 0;
while ((opts[q].dissect != NULL )&&( opts[q].optcode != code )){
q++;
}
if ( opts[q].dissect ) {
if (tree) {
/* adjust by 2 for code/len octets */
ti = proto_tree_add_text(tree, tvb, offset - 2,
length + 2, "%s (%u)",
opts[q].tree_text, length );
clv_tree = proto_item_add_subtree(ti,
*opts[q].tree_id );
} else {
clv_tree = NULL;
}
opts[q].dissect(tvb, pinfo, clv_tree, offset,
id_length, length);
} else {
#if 0 /* XXX: Left as commented out in case info about "unknown code" is ever to be displayed under a sub-tree */
if (tree) {
ti = proto_tree_add_text(tree, tvb, offset - 2,
length + 2, "Unknown code %u (%u)",
code, length);
clv_tree = proto_item_add_subtree(ti,
unknown_tree_id );
} else {
clv_tree = NULL;
}
#else
if (tree) {
proto_tree_add_text(tree, tvb, offset - 2,
length + 2, "Unknown code %u (%u)",
code, length);
}
#endif
}
offset += length;
len -= length;
}
}