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wireshark/epan/dissectors/packet-isis-clv.c

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/* packet-isis-clv.c
* Common CLV decode routines.
*
* 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_enc(wmem_packet_scope(), tvb, offset, length, ENC_ASCII));
}
}
/*
* 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_enc(wmem_packet_scope(), tvb, offset, length, ENC_ASCII);
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_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 ) {
/* adjust by 2 for code/len octets */
clv_tree = proto_tree_add_subtree_format(tree, tvb, offset - 2,
length + 2, *opts[q].tree_id, NULL, "%s (%u)",
opts[q].tree_text, length );
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 */
clv_tree = proto_tree_add_subtree_format(tree, tvb, offset - 2,
length + 2, unknown_tree_id, NULL, "Unknown code %u (%u)",
code, length);
#else
if (tree) {
proto_tree_add_text(tree, tvb, offset - 2,
length + 2, "Unknown code %u (%u)",
code, length);
}
#endif
}
offset += length;
len -= length;
}
}
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