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wireshark/epan/dissectors/packet-ltp.c

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/* packet-ltp.c
* Routines for LTP dissection
* Copyright 2009, Mithun Roy <mithunroy13@gmail.com>
*
* 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.
*/
/*
* Licklider Transmission Protocol - RFC 5326.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/expert.h>
#include <epan/reassemble.h>
#include "packet-dtn.h"
void proto_register_ltp(void);
void proto_reg_handoff_ltp(void);
#define LTP_MIN_DATA_BUFFER 5
#define LTP_MAX_HDR_EXTN 16
#define LTP_MAX_TRL_EXTN 16
/* For reassembling LTP segments */
static reassembly_table ltp_reassembly_table;
/* Initialize the protocol and registered fields */
static int proto_ltp = -1;
/* LTP Header variables */
static int hf_ltp_version = -1;
static int hf_ltp_type = -1;
static int hf_ltp_session_id = -1;
static int hf_ltp_session_orig = -1;
static int hf_ltp_session_no = -1;
static int hf_ltp_hdr_extn_cnt = -1;
static int hf_ltp_trl_extn_cnt = -1;
/* LTP Data Segment variable */
static int hf_ltp_data_clid = -1;
static int hf_ltp_data_offset = -1;
static int hf_ltp_data_length = -1;
static int hf_ltp_data_chkp = -1;
static int hf_ltp_data_rpt = -1;
/* static int hf_ltp_data_clidata = -1; */
/* LTP Report Segment variable */
static int hf_ltp_rpt_sno = -1;
static int hf_ltp_rpt_chkp = -1;
static int hf_ltp_rpt_ub = -1;
static int hf_ltp_rpt_lb = -1;
static int hf_ltp_rpt_clm_cnt = -1;
static int hf_ltp_rpt_clm_off = -1;
static int hf_ltp_rpt_clm_len = -1;
/* LTP Report Ack Segment Variable */
static int hf_ltp_rpt_ack_sno = -1;
/* LTP Session Management Segment Variable */
static int hf_ltp_cancel_code = -1;
/* LTP Header Extension Segment */
static int hf_ltp_hdr_extn_tag = -1;
static int hf_ltp_hdr_extn_len = -1;
static int hf_ltp_hdr_extn_val = -1;
/* LTP Trailer Extension Segment */
static int hf_ltp_trl_extn_tag = -1;
static int hf_ltp_trl_extn_len = -1;
static int hf_ltp_trl_extn_val = -1;
/*LTP reassembly */
static int hf_ltp_fragments = -1;
static int hf_ltp_fragment = -1;
static int hf_ltp_fragment_overlap = -1;
static int hf_ltp_fragment_overlap_conflicts = -1;
static int hf_ltp_fragment_multiple_tails = -1;
static int hf_ltp_fragment_too_long_fragment = -1;
static int hf_ltp_fragment_error = -1;
static int hf_ltp_fragment_count = -1;
static int hf_ltp_reassembled_in = -1;
static int hf_ltp_reassembled_length = -1;
static expert_field ei_ltp_neg_reception_claim_count = EI_INIT;
static expert_field ei_ltp_mal_reception_claim = EI_INIT;
static dissector_handle_t bundle_handle;
static const value_string ltp_type_codes[] = {
{0x0, "Red data, NOT {Checkpoint, EORP or EOB}"},
{0x1, "Red data, Checkpoint, NOT {EORP or EOB}"},
{0x2, "Red data, Checkpoint, EORP, NOT EOB"},
{0x3, "Red data, Checkpoint, EORP, EOB"},
{0x4, "Green data, NOT EOB"},
{0x5, "Green data, undefined"},
{0x6, "Green data, undefined"},
{0x7, "Green data, EOB"},
{0x8, "Report segment"},
{0x9, "Report-acknowledgment segment"},
{0xa, "Control segment, undefined"},
{0xb, "Control segment, undefined"},
{0xc, "Cancel segment from block sender"},
{0xd, "Cancel-acknowledgment segment to block sender"},
{0xe, "Cancel segment from block receiver"},
{0xf, "Cancel-acknowledgment segment to block receiver"},
{0,NULL}
};
static const value_string ltp_type_col_info[] = {
{0x0, "Red data"},
{0x1, "Red data"},
{0x2, "Red data"},
{0x3, "Red data"},
{0x4, "Green data"},
{0x5, "Green data"},
{0x6, "Green data"},
{0x7, "Green data"},
{0x8, "Report segment"},
{0x9, "Report ack segment"},
{0xa, "Control segment"},
{0xb, "Control segment"},
{0xc, "Cancel segment"},
{0xd, "Cancel ack segment"},
{0xe, "Cancel segment"},
{0xf, "Cancel ack segment"},
{0, NULL}
};
static const value_string ltp_cancel_codes[] = {
{0x00, "Client service canceled session"},
{0x01, "Unreachable client service"},
{0x02, "Retransmission limit exceeded"},
{0x03, "Miscolored segment"},
{0x04, "A system error"},
{0x05, "Exceeded the Retransmission-Cycles limit"},
{0, NULL}
};
static const value_string extn_tag_codes[] = {
{0x00, "LTP authentication extension"},
{0x01, "LTP cookie extension"},
{0, NULL}
};
static guint ltp_port = 1113;
/* Initialize the subtree pointers */
static gint ett_ltp = -1;
static gint ett_ltp_hdr = -1;
static gint ett_hdr_session = -1;
static gint ett_hdr_extn = -1;
static gint ett_data_segm = -1;
static gint ett_data_data_segm = -1;
static gint ett_rpt_segm = -1;
static gint ett_rpt_clm = -1;
static gint ett_rpt_ack_segm = -1;
static gint ett_session_mgmt = -1;
static gint ett_trl_extn = -1;
static gint ett_ltp_fragment = -1;
static gint ett_ltp_fragments = -1;
static const fragment_items ltp_frag_items = {
/*Fragment subtrees*/
&ett_ltp_fragment,
&ett_ltp_fragments,
/*Fragment Fields*/
&hf_ltp_fragments,
&hf_ltp_fragment,
&hf_ltp_fragment_overlap,
&hf_ltp_fragment_overlap_conflicts,
&hf_ltp_fragment_multiple_tails,
&hf_ltp_fragment_too_long_fragment,
&hf_ltp_fragment_error,
&hf_ltp_fragment_count,
/*Reassembled in field*/
&hf_ltp_reassembled_in,
/*Reassembled length field*/
&hf_ltp_reassembled_length,
/* Reassembled data field */
NULL,
/*Tag*/
"LTP fragments"
};
static int
dissect_data_segment(proto_tree *ltp_tree, tvbuff_t *tvb,packet_info *pinfo,int frame_offset,int ltp_type, guint64 session_num){
guint64 client_id;
guint64 offset;
guint64 length;
guint64 chkp_sno = 0;
guint64 rpt_sno = 0;
int segment_offset = 0;
int client_id_size;
int offset_size;
int length_size;
int chkp_sno_size;
int rpt_sno_size;
int data_offset = 0;
int data_length;
int bundle_size = 0;
int dissected_data_size = 0;
int data_count = 1;
proto_tree *ltp_data_tree;
proto_tree *ltp_data_data_tree;
tvbuff_t *datatvb;
fragment_head *frag_msg = NULL;
gboolean more_frags = TRUE;
tvbuff_t *new_tvb = NULL;
/* Extract the info for the data segment */
client_id = evaluate_sdnv_64(tvb,frame_offset + segment_offset,&client_id_size);
segment_offset+= client_id_size;
if((unsigned)(frame_offset + segment_offset) >= tvb_captured_length(tvb)){
/* This would mean the data segment is incomplete */
return 0;
}
offset = evaluate_sdnv_64(tvb,frame_offset + segment_offset,&offset_size);
segment_offset+= offset_size;
if((unsigned)(frame_offset + segment_offset) >= tvb_captured_length(tvb)){
/* This would mean the data segment is incomplete */
return 0;
}
length = evaluate_sdnv_64(tvb,frame_offset + segment_offset,&length_size);
segment_offset+= length_size;
if((unsigned)(frame_offset + segment_offset) >= tvb_captured_length(tvb)){
/* This would mean the data segment is incomplete */
return 0;
}
if(ltp_type != 0 )
{
chkp_sno = evaluate_sdnv_64(tvb,frame_offset + segment_offset,&chkp_sno_size);
segment_offset+= chkp_sno_size;
if((unsigned)(frame_offset + segment_offset) >= tvb_captured_length(tvb)){
/* This would mean the data segment is incomplete */
return 0;
}
rpt_sno = evaluate_sdnv_64(tvb,frame_offset + segment_offset,&rpt_sno_size);
segment_offset+= rpt_sno_size;
if((unsigned)(frame_offset + segment_offset) >= tvb_captured_length(tvb)){
/* This would mean the data segment is incomplete */
return 0;
}
}
/* Adding size of the data */
if ((segment_offset + (int)length < segment_offset) || (segment_offset + (int)length < (int)length)) {
/* Addition result has wrapped */
return 0;
}
segment_offset+= (int)length;
if ((segment_offset + frame_offset < segment_offset) || (segment_offset + frame_offset < frame_offset)) {
/* Addition result has wrapped */
return 0;
}
if((unsigned)(frame_offset + segment_offset) > tvb_captured_length(tvb)){
/* This would mean the data segment is incomplete */
return 0;
}
/* Create a subtree for data segment and add the other fields under it */
ltp_data_tree = proto_tree_add_subtree(ltp_tree, tvb,frame_offset, segment_offset, ett_data_segm, NULL, "Data Segment");
proto_tree_add_uint64(ltp_data_tree,hf_ltp_data_clid, tvb, frame_offset,client_id_size,client_id);
frame_offset += client_id_size;
proto_tree_add_uint64(ltp_data_tree, hf_ltp_data_offset, tvb, frame_offset,offset_size, offset);
frame_offset += offset_size;
proto_tree_add_uint64(ltp_data_tree,hf_ltp_data_length, tvb, frame_offset,length_size,length);
frame_offset += length_size;
if(ltp_type != 0 )
{
proto_tree_add_uint64(ltp_data_tree, hf_ltp_data_chkp, tvb, frame_offset,chkp_sno_size, chkp_sno);
frame_offset += chkp_sno_size;
proto_tree_add_uint64(ltp_data_tree, hf_ltp_data_rpt, tvb, frame_offset,rpt_sno_size, rpt_sno);
frame_offset += rpt_sno_size;
more_frags = FALSE;
frag_msg = fragment_add_check(&ltp_reassembly_table,
tvb, frame_offset, pinfo, (guint32)session_num, NULL,
(guint32)offset, (guint32)length, more_frags);
}
else
{
more_frags = TRUE;
frag_msg = fragment_add_check(&ltp_reassembly_table,
tvb, frame_offset, pinfo, (guint32)session_num, NULL,
(guint32)offset, (guint32)length, more_frags);
}
if(frag_msg)
{
/* Checking if the segment is completely reassembled */
if(!(frag_msg->flags & FD_PARTIAL_REASSEMBLY))
{
/* if the segment has not been fragmented, then no reassembly is needed */
if(!more_frags && offset == 0)
{
new_tvb = tvb_new_subset_remaining(tvb,frame_offset);
}
else
{
new_tvb = process_reassembled_data(tvb, frame_offset, pinfo, "Reassembled LTP Segment",
frag_msg, &ltp_frag_items,NULL, ltp_data_tree);
}
}
}
if(new_tvb)
{
data_length = tvb_captured_length(new_tvb);
while(dissected_data_size < data_length)
{
ltp_data_data_tree = proto_tree_add_subtree_format(ltp_data_tree, tvb,frame_offset, 0,
ett_data_data_segm, NULL, "Data[%d]",data_count);
datatvb = tvb_new_subset(new_tvb, data_offset, (int)data_length - dissected_data_size, tvb_captured_length(new_tvb));
bundle_size = call_dissector(bundle_handle, datatvb, pinfo, ltp_data_data_tree);
if(bundle_size == 0) { /*Couldn't parse bundle*/
col_set_str(pinfo->cinfo, COL_INFO, "Dissection Failed");
return 0; /*Give up*/
}
data_offset += bundle_size;
dissected_data_size += bundle_size;
data_count++;
}
}
else
{
if(frag_msg && more_frags)
{
col_append_fstr(pinfo->cinfo, COL_INFO, "[Reassembled in %d] ",frag_msg->reassembled_in);
}
else
{
col_append_str(pinfo->cinfo, COL_INFO, "[Unfinished LTP Segment] ");
}
}
return segment_offset;
}
static int
dissect_report_segment(tvbuff_t *tvb, packet_info *pinfo, proto_tree *ltp_tree, int frame_offset) {
guint64 rpt_sno;
guint64 chkp_sno;
guint64 upper_bound;
guint64 lower_bound;
int rcpt_clm_cnt;
guint64 offset;
guint64 length;
int rpt_sno_size;
int chkp_sno_size;
int upper_bound_size;
int lower_bound_size;
int rcpt_clm_cnt_size;
int offset_size;
int length_size;
int segment_offset = 0;
int i;
proto_item *ltp_rpt_item;
proto_item *ltp_rpt_clm_item;
proto_tree *ltp_rpt_tree;
proto_tree *ltp_rpt_clm_tree;
/* Create the subtree for report segment under the main LTP tree and all the report segment fields under it */
ltp_rpt_tree = proto_tree_add_subtree(ltp_tree, tvb, frame_offset, -1, ett_rpt_segm, &ltp_rpt_item, "Report Segment");
/* Extract the report segment info */
rpt_sno = evaluate_sdnv_64(tvb, frame_offset, &rpt_sno_size);
proto_tree_add_uint64(ltp_rpt_tree, hf_ltp_rpt_sno, tvb, frame_offset + segment_offset, rpt_sno_size, rpt_sno);
segment_offset += rpt_sno_size;
chkp_sno = evaluate_sdnv_64(tvb, frame_offset + segment_offset, &chkp_sno_size);
proto_tree_add_uint64(ltp_rpt_tree, hf_ltp_rpt_chkp, tvb, frame_offset + segment_offset, chkp_sno_size, chkp_sno);
segment_offset += chkp_sno_size;
upper_bound = evaluate_sdnv(tvb, frame_offset + segment_offset, &upper_bound_size);
proto_tree_add_uint64(ltp_rpt_tree, hf_ltp_rpt_ub, tvb, frame_offset + segment_offset, upper_bound_size, upper_bound);
segment_offset += upper_bound_size;
lower_bound = evaluate_sdnv(tvb, frame_offset + segment_offset, &lower_bound_size);
proto_tree_add_uint64(ltp_rpt_tree, hf_ltp_rpt_lb, tvb, frame_offset + segment_offset, lower_bound_size, lower_bound);
segment_offset += lower_bound_size;
rcpt_clm_cnt = evaluate_sdnv(tvb, frame_offset + segment_offset, &rcpt_clm_cnt_size);
if (rcpt_clm_cnt < 0){
proto_item_set_end(ltp_rpt_item, tvb, frame_offset + segment_offset);
expert_add_info_format(pinfo, ltp_tree, &ei_ltp_neg_reception_claim_count,
"Negative reception claim count: %d", rcpt_clm_cnt);
return 0;
}
/* Each reception claim is at least 2 bytes, so if the count is larger than the
* max number of claims we can possibly squeeze into the remaining tvbuff, then
* the packet is malformed.
*/
if (rcpt_clm_cnt > tvb_reported_length_remaining(tvb, frame_offset + segment_offset) / 2) {
proto_item_set_end(ltp_rpt_item, tvb, frame_offset + segment_offset);
expert_add_info_format(pinfo, ltp_tree, &ei_ltp_mal_reception_claim,
"Reception claim count impossibly large: %d > %d", rcpt_clm_cnt,
tvb_reported_length_remaining(tvb, frame_offset + segment_offset) / 2);
return 0;
}
proto_tree_add_uint(ltp_rpt_tree, hf_ltp_rpt_clm_cnt, tvb, frame_offset + segment_offset, rcpt_clm_cnt_size, rcpt_clm_cnt);
segment_offset += rcpt_clm_cnt_size;
ltp_rpt_clm_tree = proto_tree_add_subtree(ltp_rpt_tree, tvb, frame_offset + segment_offset, -1, ett_rpt_clm, &ltp_rpt_clm_item, "Reception claims");
/* There can be multiple reception claims in the same report segment */
for(i = 0; i<rcpt_clm_cnt; i++){
offset = evaluate_sdnv(tvb,frame_offset + segment_offset, &offset_size);
proto_tree_add_uint64_format(ltp_rpt_clm_tree, hf_ltp_rpt_clm_off, tvb, frame_offset + segment_offset, offset_size, offset,
"Offset[%d] : %"G_GINT64_MODIFIER"d", i, offset);
segment_offset += offset_size;
length = evaluate_sdnv(tvb,frame_offset + segment_offset, &length_size);
proto_tree_add_uint64_format(ltp_rpt_clm_tree, hf_ltp_rpt_clm_len, tvb, frame_offset + segment_offset, length_size, length,
"Length[%d] : %"G_GINT64_MODIFIER"d",i, length);
segment_offset += length_size;
}
proto_item_set_end(ltp_rpt_clm_item, tvb, frame_offset + segment_offset);
proto_item_set_end(ltp_rpt_item, tvb, frame_offset + segment_offset);
return segment_offset;
}
static int
dissect_report_ack_segment(proto_tree *ltp_tree, tvbuff_t *tvb,int frame_offset){
guint64 rpt_sno;
int rpt_sno_size;
int segment_offset = 0;
proto_tree *ltp_rpt_ack_tree;
/* Extracing receipt serial number info */
rpt_sno = evaluate_sdnv_64(tvb,frame_offset, &rpt_sno_size);
segment_offset += rpt_sno_size;
if((unsigned)(frame_offset + segment_offset) > tvb_captured_length(tvb)){
return 0;
}
/* Creating tree for the report ack segment */
ltp_rpt_ack_tree = proto_tree_add_subtree(ltp_tree, tvb,frame_offset, segment_offset,
ett_rpt_ack_segm, NULL, "Report Ack Segment");
proto_tree_add_uint64(ltp_rpt_ack_tree, hf_ltp_rpt_ack_sno, tvb, frame_offset,rpt_sno_size, rpt_sno);
return segment_offset;
}
static int
dissect_cancel_segment(proto_tree * ltp_tree, tvbuff_t *tvb,int frame_offset){
guint8 reason_code;
proto_tree *ltp_cancel_tree;
/* The cancel segment has only one byte, which contains the reason code. */
reason_code = tvb_get_guint8(tvb,frame_offset);
/* Creating tree for the cancel segment */
ltp_cancel_tree = proto_tree_add_subtree(ltp_tree, tvb,frame_offset, 1, ett_session_mgmt, NULL, "Cancel Segment");
proto_tree_add_uint_format_value(ltp_cancel_tree, hf_ltp_cancel_code, tvb, frame_offset, 1, reason_code,
"%x (%s)", reason_code, val_to_str_const(reason_code,ltp_cancel_codes,"Reserved"));
return 1;
}
static int
dissect_header_extn(proto_tree *ltp_tree, tvbuff_t *tvb,int frame_offset,int hdr_extn_cnt){
guint8 extn_type[LTP_MAX_HDR_EXTN];
guint64 length[LTP_MAX_HDR_EXTN];
guint64 value[LTP_MAX_HDR_EXTN];
int length_size[LTP_MAX_HDR_EXTN];
int value_size[LTP_MAX_HDR_EXTN];
int i;
int extn_offset = 0;
proto_tree *ltp_hdr_extn_tree;
/* There can be more than one header extensions */
for(i = 0; i < hdr_extn_cnt; i++){
extn_type[i] = tvb_get_guint8(tvb,frame_offset);
extn_offset++;
if((unsigned)(frame_offset + extn_offset) >= tvb_captured_length(tvb)){
return 0;
}
length[i] = evaluate_sdnv_64(tvb,frame_offset,&length_size[i]);
extn_offset += length_size[i];
if((unsigned)(frame_offset + extn_offset) >= tvb_captured_length(tvb)){
return 0;
}
value[i] = evaluate_sdnv_64(tvb,frame_offset,&value_size[i]);
extn_offset += value_size[i];
if((unsigned)(frame_offset + extn_offset) >= tvb_captured_length(tvb)){
return 0;
}
}
ltp_hdr_extn_tree = proto_tree_add_subtree(ltp_tree, tvb,frame_offset, extn_offset, ett_hdr_extn, NULL, "Header Extension");
for(i = 0; i < hdr_extn_cnt; i++){
proto_tree_add_uint_format_value(ltp_hdr_extn_tree, hf_ltp_hdr_extn_tag, tvb, frame_offset, 1, extn_type[i], "%x (%s)", extn_type[i], val_to_str_const(extn_type[i],extn_tag_codes,"Unassigned/Reserved"));
proto_tree_add_uint64_format(ltp_hdr_extn_tree, hf_ltp_hdr_extn_len, tvb, frame_offset, length_size[i],length[i], "Length [%d]: %"G_GINT64_MODIFIER"d",i+1,length[i]);
frame_offset += length_size[i];
proto_tree_add_uint64_format(ltp_hdr_extn_tree, hf_ltp_hdr_extn_val, tvb, frame_offset, value_size[i],value[i], "Value [%d]: %"G_GINT64_MODIFIER"d",i+1,value[i]);
frame_offset += value_size[i];
}
return extn_offset;
}
static int
dissect_trailer_extn(proto_tree *ltp_tree, tvbuff_t *tvb,int frame_offset,int trl_extn_cnt){
guint8 extn_type[LTP_MAX_TRL_EXTN];
guint64 length[LTP_MAX_TRL_EXTN];
guint64 value[LTP_MAX_TRL_EXTN];
int length_size[LTP_MAX_TRL_EXTN];
int value_size[LTP_MAX_TRL_EXTN];
int i;
int extn_offset = 0;
proto_tree *ltp_trl_extn_tree;
DISSECTOR_ASSERT(trl_extn_cnt < LTP_MAX_TRL_EXTN);
for(i = 0; i < trl_extn_cnt; i++){
extn_type[i] = tvb_get_guint8(tvb,frame_offset);
extn_offset++;
if((unsigned)(frame_offset + extn_offset) >= tvb_captured_length(tvb)){
return 0;
}
length[i] = evaluate_sdnv_64(tvb,frame_offset,&length_size[i]);
extn_offset += length_size[i];
if((unsigned)(frame_offset + extn_offset) >= tvb_captured_length(tvb)){
return 0;
}
value[i] = evaluate_sdnv_64(tvb,frame_offset,&value_size[i]);
extn_offset += value_size[i];
if((unsigned)(frame_offset + extn_offset) >= tvb_captured_length(tvb)){
return 0;
}
}
ltp_trl_extn_tree = proto_tree_add_subtree(ltp_tree, tvb,frame_offset, extn_offset, ett_trl_extn, NULL, "Header Extension");
for(i = 0; i < trl_extn_cnt; i++){
proto_tree_add_uint_format_value(ltp_trl_extn_tree, hf_ltp_trl_extn_tag, tvb, frame_offset, 1, extn_type[i], "%x (%s)", extn_type[i], val_to_str_const(extn_type[i],extn_tag_codes,"Unassigned/Reserved"));
proto_tree_add_uint64_format(ltp_trl_extn_tree, hf_ltp_trl_extn_len, tvb, frame_offset, length_size[i], length[i], "Length [%d]: %"G_GINT64_MODIFIER"d",i+1,length[i]);
frame_offset += length_size[i];
proto_tree_add_uint64_format(ltp_trl_extn_tree, hf_ltp_trl_extn_val, tvb, frame_offset, value_size[i], value[i], "Value [%d]: %"G_GINT64_MODIFIER"d",i+0,value[i]);
frame_offset += value_size[i];
}
return extn_offset;
}
static int
dissect_ltp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
proto_item *ti = NULL;
proto_tree *ltp_tree = NULL;
int frame_offset;
int header_offset;
int segment_offset = 0;
int hdr_extn_offset = 0;
int trl_extn_offset = 0;
guint8 ltp_hdr;
gint ltp_type;
guint8 ltp_extn_cnt;
gint hdr_extn_cnt;
gint trl_extn_cnt;
guint64 engine_id;
guint64 session_num;
int engine_id_size;
int session_num_size;
proto_item *ltp_header_item = NULL;
proto_item *ltp_session_item = NULL;
proto_tree *ltp_header_tree = NULL;
proto_tree *ltp_session_tree = NULL;
/* Check that there's enough data */
if(tvb_captured_length(tvb) < LTP_MIN_DATA_BUFFER){
return 0;
}
frame_offset = 0;
header_offset = 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "LTP Segment");
/* Extract all the header info from the packet */
ltp_hdr = tvb_get_guint8(tvb, frame_offset);
header_offset++;
engine_id = evaluate_sdnv_64(tvb,frame_offset + header_offset,&engine_id_size);
header_offset += engine_id_size;
if((unsigned)header_offset >= tvb_captured_length(tvb)){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
session_num = evaluate_sdnv_64(tvb,frame_offset + header_offset,&session_num_size);
header_offset += session_num_size;
if((unsigned)header_offset >= tvb_captured_length(tvb)){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
ti = proto_tree_add_item(tree, proto_ltp, tvb, 0, -1, ENC_NA);
ltp_tree = proto_item_add_subtree(ti, ett_ltp);
/* Adding Header Subtree */
ltp_header_tree = proto_tree_add_subtree(ltp_tree, tvb, frame_offset, header_offset+1, ett_ltp_hdr, NULL, "LTP Header");
proto_tree_add_uint(ltp_header_tree,hf_ltp_version,tvb,frame_offset,1,hi_nibble(ltp_hdr));
ltp_type = lo_nibble(ltp_hdr);
proto_tree_add_uint_format_value(ltp_header_tree,hf_ltp_type,tvb,frame_offset,1,ltp_type,"%x (%s)",
ltp_type,val_to_str_const(ltp_type,ltp_type_codes,"Invalid"));
frame_offset++;
/* Adding the session id subtree */
ltp_session_item = proto_tree_add_item(ltp_header_item,hf_ltp_session_id,tvb,frame_offset, engine_id_size + session_num_size,ENC_NA);
ltp_session_tree = proto_item_add_subtree(ltp_session_item,ett_hdr_session);
proto_tree_add_uint64(ltp_session_tree,hf_ltp_session_orig,tvb,frame_offset,engine_id_size,engine_id);
frame_offset+=engine_id_size;
proto_tree_add_uint64(ltp_session_tree,hf_ltp_session_no, tvb, frame_offset,session_num_size,session_num);
frame_offset+=session_num_size;
/* Adding Extension count to the header tree */
ltp_extn_cnt = tvb_get_guint8(tvb,frame_offset);
hdr_extn_cnt = hi_nibble(ltp_extn_cnt);
trl_extn_cnt = lo_nibble(ltp_extn_cnt);
proto_tree_add_uint(ltp_header_tree,hf_ltp_hdr_extn_cnt,tvb,frame_offset,1,hdr_extn_cnt);
proto_tree_add_uint(ltp_header_tree,hf_ltp_trl_extn_cnt,tvb,frame_offset,1,trl_extn_cnt);
frame_offset++;
col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(ltp_type,ltp_type_col_info,"Protocol Error"));
if((unsigned)frame_offset >= tvb_captured_length(tvb)){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
/* Check if there are any header extensions */
if(hdr_extn_cnt > 0){
hdr_extn_offset = dissect_header_extn(ltp_tree, tvb, frame_offset,hdr_extn_cnt);
if(hdr_extn_offset == 0){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
frame_offset += hdr_extn_offset;
}
if((unsigned)frame_offset >= tvb_captured_length(tvb)){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
/* Call sub routines to handle the segment content*/
if((ltp_type >= 0) && (ltp_type < 8)){
segment_offset = dissect_data_segment(ltp_tree,tvb,pinfo,frame_offset,ltp_type,session_num);
if(segment_offset == 0){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
}
else if(ltp_type == 8){
segment_offset = dissect_report_segment(tvb, pinfo, ltp_tree,frame_offset);
if(segment_offset == 0){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
}
else if(ltp_type == 9){
segment_offset = dissect_report_ack_segment(ltp_tree,tvb,frame_offset);
if(segment_offset == 0){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
}
else if(ltp_type == 12 || ltp_type == 14){
segment_offset = dissect_cancel_segment(ltp_tree,tvb,frame_offset);
if(segment_offset == 0){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
}
frame_offset += segment_offset;
/* Check to see if there are any trailer extensions */
if(trl_extn_cnt > 0){
if((unsigned)frame_offset >= tvb_captured_length(tvb)){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
trl_extn_offset = dissect_trailer_extn(ltp_tree, tvb, frame_offset,trl_extn_cnt);
if(trl_extn_offset == 0){
col_set_str(pinfo->cinfo, COL_INFO, "Protocol Error");
return 0;
}
}
/* Return the amount of data this dissector was able to dissect */
return tvb_captured_length(tvb);
}
static void
ltp_defragment_init(void) {
reassembly_table_init(&ltp_reassembly_table,
&addresses_reassembly_table_functions);
}
static void
ltp_defragment_cleanup(void) {
reassembly_table_destroy(&ltp_reassembly_table);
}
/* Register the protocol with Wireshark */
void
proto_register_ltp(void)
{
module_t *ltp_module;
static hf_register_info hf[] = {
{&hf_ltp_version,
{"LTP Version","ltp.version",
FT_UINT8,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_type,
{"LTP Type","ltp.type",
FT_UINT8,BASE_HEX,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_session_id,
{"Session ID","ltp.session",
FT_NONE,BASE_NONE,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_session_orig,
{"Session originator","ltp.session.orig",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_session_no,
{"Session number","ltp.session.number",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_hdr_extn_cnt,
{"Header Extension Count","ltp.hdr.extn.cnt",
FT_UINT8,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_trl_extn_cnt,
{"Trailer Extension Count","ltp.trl.extn.cnt",
FT_UINT8,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_data_clid,
{"Client service ID","ltp.data.client.id",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_data_offset,
{"Offset","ltp.data.offset",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_data_length,
{"Length","ltp.data.length",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_data_chkp,
{"Checkpoint serial number","ltp.data.chkp",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_data_rpt,
{"Report serial number","ltp.data.rpt",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
#if 0
{&hf_ltp_data_clidata,
{"Client service data","ltp.data.data",
FT_BYTES,BASE_NONE,NULL, 0x0, NULL, HFILL}
},
#endif
{&hf_ltp_rpt_sno,
{"Report serial number","ltp.rpt.sno",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_rpt_chkp,
{"Checkpoint serial number","ltp.rpt.chkp",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_rpt_ub,
{"Upper bound","ltp.rpt.ub",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_rpt_lb,
{"Lower bound","ltp.rpt.lb",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_rpt_clm_cnt,
{"Reception claim count","ltp.rpt.clm.cnt",
FT_UINT8,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_rpt_clm_off,
{"Offset","ltp.rpt.clm.off",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_rpt_clm_len,
{"Length","ltp.rpt.clm.len",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_rpt_ack_sno,
{"Report serial number","ltp.rpt.ack.sno",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_cancel_code,
{"Cancel code","ltp.cancel.code",
FT_UINT8,BASE_HEX,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_hdr_extn_tag,
{"Extension tag","ltp.hdr.extn.tag",
FT_UINT8,BASE_HEX,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_hdr_extn_len,
{"Length","ltp.hdr.extn.len",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_hdr_extn_val,
{"Value","ltp.hdr.extn.val",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_trl_extn_tag,
{"Extension tag","ltp.trl.extn.tag",
FT_UINT8,BASE_HEX,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_trl_extn_len,
{"Length","ltp.trl.extn.len",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_trl_extn_val,
{"Value","ltp.trl.extn.val",
FT_UINT64,BASE_DEC,NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragments,
{"LTP Fragments", "ltp.fragments",
FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragment,
{"LTP Fragment", "ltp.fragment",
FT_FRAMENUM, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragment_overlap,
{"LTP fragment overlap", "ltp.fragment.overlap",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragment_overlap_conflicts,
{"LTP fragment overlapping with conflicting data",
"ltp.fragment.overlap.conflicts",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragment_multiple_tails,
{"LTP has multiple tails", "ltp.fragment.multiple_tails",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragment_too_long_fragment,
{"LTP fragment too long", "ltp.fragment.too_long_fragment",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragment_error,
{"LTP defragmentation error", "ltp.fragment.error",
FT_FRAMENUM, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_fragment_count,
{"LTP fragment count", "ltp.fragment.count",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_reassembled_in,
{"LTP reassembled in", "ltp.reassembled.in",
FT_FRAMENUM, BASE_NONE, NULL, 0x0, NULL, HFILL}
},
{&hf_ltp_reassembled_length,
{"LTP reassembled length", "ltp.reassembled.length",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}
}
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_ltp,
&ett_ltp_hdr,
&ett_hdr_session,
&ett_hdr_extn,
&ett_data_segm,
&ett_data_data_segm,
&ett_rpt_segm,
&ett_rpt_clm,
&ett_rpt_ack_segm,
&ett_session_mgmt,
&ett_trl_extn,
&ett_ltp_fragment,
&ett_ltp_fragments
};
static ei_register_info ei[] = {
{ &ei_ltp_neg_reception_claim_count, { "ltp.neg_reception_claim_count", PI_UNDECODED, PI_ERROR, "Negative reception claim count", EXPFILL }},
{ &ei_ltp_mal_reception_claim, { "ltp.mal_reception_claim", PI_MALFORMED, PI_ERROR, "Reception claim count impossibly large", EXPFILL }},
};
expert_module_t* expert_ltp;
/* Register the protocol name and description */
proto_ltp = proto_register_protocol("Licklider Transmission Protocol",
"LTP", "ltp");
proto_register_field_array(proto_ltp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_ltp = expert_register_protocol(proto_ltp);
expert_register_field_array(expert_ltp, ei, array_length(ei));
ltp_module = prefs_register_protocol(proto_ltp, proto_reg_handoff_ltp);
prefs_register_obsolete_preference(ltp_module, "udp.port");
prefs_register_uint_preference(ltp_module, "port", "LTP Port",
"The UDP or DCCP port to accept LTP Connections",
10, &ltp_port);
register_init_routine(ltp_defragment_init);
register_cleanup_routine(ltp_defragment_cleanup);
}
void
proto_reg_handoff_ltp(void)
{
static gboolean initialized = FALSE;
static dissector_handle_t ltp_handle;
static int currentPort;
if (!initialized) {
ltp_handle = create_dissector_handle(dissect_ltp, proto_ltp);
bundle_handle = find_dissector("bundle");
initialized = TRUE;
} else {
dissector_delete_uint("udp.port", currentPort, ltp_handle);
dissector_delete_uint("dccp.port", currentPort, ltp_handle);
}
currentPort = ltp_port;
dissector_add_uint("udp.port", currentPort, ltp_handle);
dissector_add_uint("dccp.port", currentPort, ltp_handle);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
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