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wireshark/epan/dissectors/packet-wcp.c

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/* packet-wcp.c
* Routines for Wellfleet Compression frame disassembly
* Copyright 2001, Jeffrey C. Foster <jfoste@woodward.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* ToDo:
* Add preference to allow/disallow decompression
* Calculate and verify check byte (last byte), if only we knew how!
* Handle Wellfleet compression over PPP links.
* - This will require changing the sub-dissector call
* routine to determine if layer 2 is frame relay or
* or PPP and different sub-dissector routines for each.
*
* Based upon information in the Nortel TCL based Pcaptap code.
*http://www.mynetworkforum.com/tools/PCAPTAP/pcaptap-Win32-3.00.exe
*
* And lzss algorithm
*http://www.rasip.fer.hr/research/compress/algorithms/fund/lz/lzss.html
*/
/*
* Wellfleet compression is a variation on LZSS encoding.
*
* Compression is done by keeping a sliding window of previous
* data transmited. The sender will use a pattern match to
* encode repeated data as a data pointer field. Then a stream
* of pointers and actual data bytes. The pointer values include
* an offset to previous data in the stream and the length of the
* matching data.
*
* The data pattern matching is done on the octets.
*
* The data is encoded as 8 field blocks with a compression flag
* byte at the beginning. If the bit is set in the compression
* flag, then that field has a compression field. If it isn't set
* then the byte is raw data.
*
* The compression field is either 2 or 3 bytes long. The length
* is determined by the length of the matching data, for short
* matches the match length is encoded in the high nibble of the
* first byte. Otherwise the third byte of the field contains
* the match length.
*
* First byte -
* lower 4 bits:
* High order nibble of the offset
*
* upper 4 bits:
* 1 = length is in 3rd byte
* 2-F = length of matching data - 1
*
* Second byte -
* Lower byte of the source offset.
*
* Third byte -
* Length of match - 1 if First byte upper nibble = 1, otherwise
* this byte isn't added to data stream.
*
* Example:
* Uncompressed data (hex): 11 22 22 22 22 33 44 55 66 77
*
*
* Compression data :
* Flag bits: 0x20 (third field is compressed)
* Data: 11 22 20 00 33 44 55
* / / / /
* raw data ------+--+ / /
* (Comp length - 1)<<4+ /
* Data offset ----------+
*
* Output data (hex): 20 11 22 20 00 33 44 55 66 77
*
* In this example the copy src is one byte behind the copy destination
* so if appears as if output is being loaded with the source byte.
*
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/proto_data.h>
#include <wiretap/wtap.h>
#include <wsutil/pint.h>
#include <epan/conversation.h>
#include <epan/etypes.h>
#include <epan/nlpid.h>
#include <epan/expert.h>
#include <epan/exceptions.h>
#define MAX_WIN_BUF_LEN 0x7fff /* storage size for decompressed data */
#define MAX_WCP_BUF_LEN 2048 /* storage size for compressed data */
#define FROM_DCE 0x80 /* for direction setting */
void proto_register_wcp(void);
void proto_reg_handoff_wcp(void);
typedef struct {
guint8 *buf_cur;
guint8 buffer[MAX_WIN_BUF_LEN];
/* initialized bytes in the buffer (since buf_cur may wrap around) */
guint16 initialized;
} wcp_window_t;
typedef struct {
wcp_window_t recv;
wcp_window_t send;
} wcp_circuit_data_t;
/* XXX do I really want the length in here */
typedef struct {
guint16 len;
guint8 buffer[MAX_WCP_BUF_LEN];
} wcp_pdata_t;
static int proto_wcp = -1;
static int hf_wcp_cmd = -1;
static int hf_wcp_ext_cmd = -1;
static int hf_wcp_seq = -1;
static int hf_wcp_chksum = -1;
static int hf_wcp_tid = -1;
static int hf_wcp_rev = -1;
static int hf_wcp_init = -1;
static int hf_wcp_seq_size = -1;
static int hf_wcp_alg = -1;
static int hf_wcp_alg_cnt = -1;
static int hf_wcp_alg_a = -1;
static int hf_wcp_alg_b = -1;
static int hf_wcp_alg_c = -1;
static int hf_wcp_alg_d = -1;
/* static int hf_wcp_rexmit = -1; */
static int hf_wcp_hist_size = -1;
static int hf_wcp_ppc = -1;
static int hf_wcp_pib = -1;
static int hf_wcp_compressed_data = -1;
static int hf_wcp_comp_bits = -1;
/* static int hf_wcp_comp_marker = -1; */
static int hf_wcp_short_len = -1;
static int hf_wcp_long_len = -1;
static int hf_wcp_short_run = -1;
static int hf_wcp_long_run = -1;
static int hf_wcp_offset = -1;
static gint ett_wcp = -1;
static gint ett_wcp_comp_data = -1;
static gint ett_wcp_field = -1;
static expert_field ei_wcp_compressed_data_exceeds = EI_INIT;
static expert_field ei_wcp_uncompressed_data_exceeds = EI_INIT;
static expert_field ei_wcp_invalid_window_offset = EI_INIT;
static expert_field ei_wcp_buffer_too_long = EI_INIT;
/* static expert_field ei_wcp_invalid_match_length = EI_INIT; */
static dissector_handle_t fr_uncompressed_handle;
/*
* Bits in the address field.
*/
#define WCP_CMD 0xf0 /* WCP Command */
#define WCP_EXT_CMD 0x0f /* WCP Extended Command */
#define WCP_SEQ 0x0fff /* WCP Sequence number */
#define WCP_OFFSET_MASK 0x0fff /* WCP Pattern source offset */
#define PPC_COMPRESSED_IND 0x0
#define PPC_UNCOMPRESSED_IND 0x1
#define PPC_TPPC_COMPRESSED_IND 0x2
#define PPC_TPPC_UNCOMPRESSED_IND 0x3
#define CONNECT_REQ 0x4
#define CONNECT_ACK 0x5
#define CONNECT_NAK 0x6
#define DISCONNECT_REQ 0x7
#define DISCONNECT_ACK 0x8
#define INIT_REQ 0x9
#define INIT_ACK 0xa
#define RESET_REQ 0xb
#define RESET_ACK 0xc
#define REXMIT_NAK 0xd
static const value_string cmd_string[] = {
{0, "Compressed Data"},
{1, "Uncompressed Data"},
{15, "Extended"},
{ 0, NULL }
};
static const value_string ext_cmd_string[] = {
{0, "Per Packet Compression"},
{4, "Connect Req"},
{5, "Connect Ack"},
{9, "Init Req"},
{0x0a, "Init Ack"},
{ 0, NULL }
};
static tvbuff_t *wcp_uncompress(tvbuff_t *src_tvb, int offset, packet_info *pinfo, proto_tree *tree);
static wcp_window_t *get_wcp_window_ptr(packet_info *pinfo);
static void
dissect_wcp_con_req(tvbuff_t *tvb, int offset, proto_tree *tree) {
/* WCP connector request message */
guint32 alg_cnt;
proto_tree_add_item(tree, hf_wcp_tid, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_wcp_rev, tvb, offset + 2, 1, ENC_NA);
proto_tree_add_item(tree, hf_wcp_init, tvb, offset + 3, 1, ENC_NA);
proto_tree_add_item(tree, hf_wcp_seq_size, tvb, offset + 4, 1, ENC_NA);
proto_tree_add_item_ret_uint(tree, hf_wcp_alg_cnt, tvb, offset + 5, 1, ENC_NA, &alg_cnt);
proto_tree_add_item(tree, hf_wcp_alg_a, tvb, offset + 6, 1, ENC_NA);
if (alg_cnt > 1)
proto_tree_add_item(tree, hf_wcp_alg_b, tvb, offset + 7, 1, ENC_NA);
if (alg_cnt > 2)
proto_tree_add_item(tree, hf_wcp_alg_c, tvb, offset + 8, 1, ENC_NA);
if (alg_cnt > 3)
proto_tree_add_item(tree, hf_wcp_alg_d, tvb, offset + 9, 1, ENC_NA);
}
static void
dissect_wcp_con_ack(tvbuff_t *tvb, int offset, proto_tree *tree) {
/* WCP connector ack message */
proto_tree_add_item(tree, hf_wcp_tid, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_wcp_rev, tvb, offset + 2, 1, ENC_NA);
proto_tree_add_item(tree, hf_wcp_seq_size, tvb, offset + 3, 1, ENC_NA);
proto_tree_add_item(tree, hf_wcp_alg, tvb, offset + 4, 1, ENC_NA);
}
static void
dissect_wcp_init(tvbuff_t *tvb, int offset, proto_tree *tree) {
/* WCP Initiate Request/Ack message */
proto_tree_add_item(tree, hf_wcp_tid, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_wcp_rev, tvb, offset + 2, 1, ENC_NA);
proto_tree_add_item(tree, hf_wcp_hist_size, tvb, offset + 3, 1, ENC_NA);
proto_tree_add_item(tree, hf_wcp_ppc, tvb, offset + 4, 1, ENC_NA);
proto_tree_add_item(tree, hf_wcp_pib, tvb, offset + 5, 1, ENC_NA);
}
static void
dissect_wcp_reset(tvbuff_t *tvb, int offset, proto_tree *tree) {
/* Process WCP Reset Request/Ack message */
proto_tree_add_item(tree, hf_wcp_tid, tvb, offset, 2, ENC_BIG_ENDIAN);
}
static void wcp_save_data(tvbuff_t *tvb, packet_info *pinfo, proto_tree* tree) {
wcp_window_t *buf_ptr = 0;
size_t len;
/* discard first 2 bytes, header and last byte (check byte) */
len = tvb_reported_length(tvb) - 3;
buf_ptr = get_wcp_window_ptr(pinfo);
if ((buf_ptr->buf_cur + len) <= (buf_ptr->buffer + MAX_WIN_BUF_LEN)) {
tvb_memcpy(tvb, buf_ptr->buf_cur, 2, len);
buf_ptr->buf_cur += len;
} else {
guint8 *buf_end = buf_ptr->buffer + MAX_WIN_BUF_LEN;
tvb_memcpy(tvb, buf_ptr->buf_cur, 2, buf_end - buf_ptr->buf_cur);
if (buf_ptr->buf_cur + len <= buf_end) {
tvb_memcpy(tvb, buf_ptr->buffer, (gint) (buf_end - buf_ptr->buf_cur-2),
len - (buf_end - buf_ptr->buf_cur));
buf_ptr->buf_cur += len - MAX_WIN_BUF_LEN;
} else {
proto_tree_add_expert(tree, pinfo, &ei_wcp_buffer_too_long, tvb, 0, -1);
}
}
}
static int dissect_wcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) {
proto_tree *wcp_tree;
proto_item *ti;
int wcp_header_len;
guint16 temp, cmd, ext_cmd, seq;
tvbuff_t *next_tvb;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "WCP");
col_clear(pinfo->cinfo, COL_INFO);
temp = tvb_get_ntohs(tvb, 0);
cmd = (temp & 0xf000) >> 12;
ext_cmd = (temp & 0x0f00) >> 8;
if (cmd == 0xf)
wcp_header_len = 1;
else
wcp_header_len = 2;
seq = temp & 0x0fff;
/* XXX should test seq to be sure it the last + 1 !! */
col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(cmd, cmd_string, "Unknown"));
if (cmd == 0xf)
col_append_fstr(pinfo->cinfo, COL_INFO, ", %s",
val_to_str_const(ext_cmd, ext_cmd_string, "Unknown"));
ti = proto_tree_add_item(tree, proto_wcp, tvb, 0, wcp_header_len, ENC_NA);
wcp_tree = proto_item_add_subtree(ti, ett_wcp);
proto_tree_add_item(wcp_tree, hf_wcp_cmd, tvb, 0, 1, ENC_NA);
if (cmd == 0xf) {
proto_tree_add_item(wcp_tree, hf_wcp_ext_cmd, tvb, 1, 1, ENC_NA);
switch (ext_cmd) {
case CONNECT_REQ:
dissect_wcp_con_req(tvb, 1, wcp_tree);
break;
case CONNECT_ACK:
dissect_wcp_con_ack(tvb, 1, wcp_tree);
break;
case INIT_REQ:
case INIT_ACK:
dissect_wcp_init(tvb, 1, wcp_tree);
break;
case RESET_REQ:
case RESET_ACK:
dissect_wcp_reset(tvb, 1, wcp_tree);
break;
default:
break;
}
} else {
proto_tree_add_uint(wcp_tree, hf_wcp_seq, tvb, 0, 2, seq);
}
/* exit if done */
if (cmd != 1 && cmd != 0 && !(cmd == 0xf && ext_cmd == 0))
return 2;
if (cmd == 1) { /* uncompressed data */
if (!pinfo->fd->visited) { /* if first pass */
wcp_save_data(tvb, pinfo, wcp_tree);
}
next_tvb = tvb_new_subset_remaining(tvb, wcp_header_len);
} else { /* cmd == 0 || (cmd == 0xf && ext_cmd == 0) */
next_tvb = wcp_uncompress(tvb, wcp_header_len, pinfo, wcp_tree);
if (!next_tvb) {
return tvb_captured_length(tvb);
}
}
/* add the check byte */
proto_tree_add_checksum(wcp_tree, tvb, tvb_reported_length(tvb) - 1, hf_wcp_chksum, -1, NULL, pinfo, 0, ENC_NA, PROTO_CHECKSUM_NO_FLAGS);
call_dissector(fr_uncompressed_handle, next_tvb, pinfo, tree);
return tvb_captured_length(tvb);
}
static guint8 *
decompressed_entry(guint8 *dst, guint16 data_offset,
guint16 data_cnt, int *len, wcp_window_t *buf_ptr)
{
const guint8 *src;
guint8 *buf_start, *buf_end;
buf_start = buf_ptr->buffer;
buf_end = buf_ptr->buffer + MAX_WIN_BUF_LEN;
/* do the decompression for one field */
src = (dst - 1 - data_offset);
if (src < buf_start)
src += MAX_WIN_BUF_LEN;
/* XXX could do some fancy memory moves, later if speed is problem */
while(data_cnt--) {
*dst = *src;
if (buf_ptr->initialized < MAX_WIN_BUF_LEN)
buf_ptr->initialized++;
if ( ++(*len) >MAX_WCP_BUF_LEN) {
return NULL; /* end of buffer error */
}
if (dst++ == buf_end)
dst = buf_start;
if (src++ == buf_end)
src = buf_start;
}
return dst;
}
static
wcp_window_t *get_wcp_window_ptr(packet_info *pinfo) {
/* find the circuit for this DLCI, create one if needed */
/* and return the wcp_window data structure pointer */
/* for the direction of this packet */
conversation_t *conv;
wcp_circuit_data_t *wcp_circuit_data;
conv = find_or_create_conversation(pinfo);
wcp_circuit_data = (wcp_circuit_data_t *)conversation_get_proto_data(conv, proto_wcp);
if (!wcp_circuit_data) {
wcp_circuit_data = wmem_new(wmem_file_scope(), wcp_circuit_data_t);
wcp_circuit_data->recv.buf_cur = wcp_circuit_data->recv.buffer;
wcp_circuit_data->recv.initialized = 0;
wcp_circuit_data->send.buf_cur = wcp_circuit_data->send.buffer;
wcp_circuit_data->send.initialized = 0;
conversation_add_proto_data(conv, proto_wcp, wcp_circuit_data);
}
if (pinfo->pseudo_header->dte_dce.flags & FROM_DCE)
return &wcp_circuit_data->recv;
else
return &wcp_circuit_data->send;
}
static tvbuff_t *wcp_uncompress(tvbuff_t *src_tvb, int offset, packet_info *pinfo, proto_tree *tree) {
/* do the packet data uncompression and load it into the dst buffer */
proto_tree *cd_tree, *sub_tree;
proto_item *cd_item, *ti;
int len, i;
int cnt = tvb_reported_length(src_tvb) - 1;/* don't include check byte */
guint8 *dst, *src, *buf_start, *buf_end, comp_flag_bits = 0;
guint16 data_offset, data_cnt;
guint8 src_buf[ MAX_WCP_BUF_LEN];
tvbuff_t *tvb;
wcp_window_t *buf_ptr = 0;
wcp_pdata_t *pdata_ptr;
buf_ptr = get_wcp_window_ptr(pinfo);
buf_start = buf_ptr->buffer;
buf_end = buf_start + MAX_WIN_BUF_LEN;
cd_item = proto_tree_add_item(tree, hf_wcp_compressed_data,
src_tvb, offset, cnt - offset, ENC_NA);
cd_tree = proto_item_add_subtree(cd_item, ett_wcp_comp_data);
if (cnt - offset > MAX_WCP_BUF_LEN) {
expert_add_info_format(pinfo, cd_item, &ei_wcp_compressed_data_exceeds,
"Compressed data exceeds maximum buffer length (%d > %d)",
cnt - offset, MAX_WCP_BUF_LEN);
return NULL;
}
/*
* XXX - this will throw an exception if a snapshot length cut short
* the data. We may want to try to dissect the data in that case,
* and we may even want to try to decompress it, *but* we will
* want to mark the buffer of decompressed data as incomplete, so
* that we don't try to use it for decompressing later packets.
*/
src = (guint8 *)tvb_memcpy(src_tvb, src_buf, offset, cnt - offset);
dst = buf_ptr->buf_cur;
len = 0;
i = -1;
while(offset < cnt) {
/* There are i bytes left for this byte of flag bits */
if ( --i >= 0) {
/*
* There's still at least one more byte left for
* the current set of compression flag bits; is
* it compressed data or uncompressed data?
*/
if (comp_flag_bits & 0x80) {
/* This byte is compressed data */
if (!(offset + 1 < cnt)) {
/*
* The data offset runs past the
* end of the data.
*/
return NULL;
}
data_offset = pntoh16(src) & WCP_OFFSET_MASK;
if ((*src & 0xf0) == 0x10) {
/*
* The count of bytes to copy from
* the dictionary window is in the
* byte following the data offset.
*/
if (!(offset + 2 < cnt)) {
/*
* The data count runs past the
* end of the data.
*/
return NULL;
}
data_cnt = *(src + 2) + 1;
if (tree) {
ti = proto_tree_add_item(cd_tree, hf_wcp_long_run, src_tvb,
offset, 3, ENC_NA);
sub_tree = proto_item_add_subtree(ti, ett_wcp_field);
proto_tree_add_uint(sub_tree, hf_wcp_offset, src_tvb,
offset, 2, data_offset);
proto_tree_add_item(sub_tree, hf_wcp_long_len, src_tvb,
offset+2, 1, ENC_BIG_ENDIAN);
}
src += 3;
offset += 3;
} else {
/*
* The count of bytes to copy from
* the dictionary window is in
* the upper 4 bits of the next
* byte.
*/
data_cnt = (*src >> 4) + 1;
if (tree) {
ti = proto_tree_add_item(cd_tree, hf_wcp_short_run, src_tvb,
offset, 2, ENC_NA);
sub_tree = proto_item_add_subtree(ti, ett_wcp_field);
proto_tree_add_uint(sub_tree, hf_wcp_short_len, src_tvb,
offset, 1, *src);
proto_tree_add_uint(sub_tree, hf_wcp_offset, src_tvb,
offset, 2, data_offset);
}
src += 2;
offset += 2;
}
if (data_offset + 1 > buf_ptr->initialized) {
expert_add_info_format(pinfo, cd_item, &ei_wcp_invalid_window_offset,
"Data offset exceeds valid window size (%d > %d)",
data_offset+1, buf_ptr->initialized);
return NULL;
}
if (data_offset + 1 < data_cnt) {
expert_add_info_format(pinfo, cd_item, &ei_wcp_invalid_window_offset,
"Data count exceeds offset (%d > %d)",
data_cnt, data_offset+1);
return NULL;
}
if ( !pinfo->fd->visited) { /* if first pass */
dst = decompressed_entry(dst,
data_offset, data_cnt, &len,
buf_ptr);
if (dst == NULL) {
expert_add_info_format(pinfo, cd_item, &ei_wcp_uncompressed_data_exceeds,
"Uncompressed data exceeds maximum buffer length (%d > %d)",
len, MAX_WCP_BUF_LEN);
return NULL;
}
}
}else {
/*
* This byte is uncompressed data; is there
* room for it in the buffer of uncompressed
* data?
*/
if ( ++len >MAX_WCP_BUF_LEN) {
/* No - report an error. */
expert_add_info_format(pinfo, cd_item, &ei_wcp_uncompressed_data_exceeds,
"Uncompressed data exceeds maximum buffer length (%d > %d)",
len, MAX_WCP_BUF_LEN);
return NULL;
}
if ( !pinfo->fd->visited) {
/*
* This is the first pass through
* the packets, so copy it to the
* buffer of uncompressed data.
*/
*dst = *src;
if (dst++ == buf_end)
dst = buf_start;
if (buf_ptr->initialized < MAX_WIN_BUF_LEN)
buf_ptr->initialized++;
}
++src;
++offset;
}
/* Skip to the next compression flag bit */
comp_flag_bits <<= 1;
}else {
/*
* There are no more bytes left for the current
* set of compression flag bits, so this byte
* is another byte of compression flag bits.
*/
comp_flag_bits = *src++;
proto_tree_add_uint(cd_tree, hf_wcp_comp_bits, src_tvb, offset, 1,
comp_flag_bits);
offset++;
i = 8;
}
}
if (pinfo->fd->visited) { /* if not first pass */
/* get uncompressed data */
pdata_ptr = (wcp_pdata_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_wcp, 0);
if (!pdata_ptr) { /* exit if no data */
REPORT_DISSECTOR_BUG("Can't find uncompressed data");
return NULL;
}
len = pdata_ptr->len;
} else {
if (buf_ptr->buf_cur + len > buf_end) {
expert_add_info_format(pinfo, cd_item, &ei_wcp_invalid_window_offset,
"Uncompressed data exceeds available buffer length (%d > %d)",
len, (int) (buf_end - buf_ptr->buf_cur));
return NULL;
}
/* save the new data as per packet data */
pdata_ptr = wmem_new(wmem_file_scope(), wcp_pdata_t);
memcpy( &pdata_ptr->buffer, buf_ptr->buf_cur, len);
pdata_ptr->len = len;
p_add_proto_data(wmem_file_scope(), pinfo, proto_wcp, 0, (void*)pdata_ptr);
buf_ptr->buf_cur = dst;
}
tvb = tvb_new_child_real_data(src_tvb, pdata_ptr->buffer, pdata_ptr->len, pdata_ptr->len);
/* Add new data to the data source list */
add_new_data_source(pinfo, tvb, "Uncompressed WCP");
return tvb;
}
void
proto_register_wcp(void)
{
static hf_register_info hf[] = {
{ &hf_wcp_cmd,
{ "Command", "wcp.cmd", FT_UINT8, BASE_HEX, VALS(cmd_string), WCP_CMD,
"Compression Command", HFILL }},
{ &hf_wcp_ext_cmd,
{ "Extended Command", "wcp.ext_cmd", FT_UINT8, BASE_HEX, VALS(ext_cmd_string), WCP_EXT_CMD,
"Extended Compression Command", HFILL }},
{ &hf_wcp_seq,
{ "SEQ", "wcp.seq", FT_UINT16, BASE_HEX, NULL, WCP_SEQ,
"Sequence Number", HFILL }},
{ &hf_wcp_chksum,
{ "Checksum", "wcp.checksum", FT_UINT8, BASE_DEC, NULL, 0,
"Packet Checksum", HFILL }},
{ &hf_wcp_tid,
{ "TID", "wcp.tid", FT_UINT16, BASE_DEC, NULL, 0,
NULL, HFILL }},
{ &hf_wcp_rev,
{ "Revision", "wcp.rev", FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }},
{ &hf_wcp_init,
{ "Initiator", "wcp.init", FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }},
{ &hf_wcp_seq_size,
{ "Seq Size", "wcp.seq_size", FT_UINT8, BASE_DEC, NULL, 0,
"Sequence Size", HFILL }},
{ &hf_wcp_alg_cnt,
{ "Alg Count", "wcp.alg_cnt", FT_UINT8, BASE_DEC, NULL, 0,
"Algorithm Count", HFILL }},
{ &hf_wcp_alg_a,
{ "Alg 1", "wcp.alg1", FT_UINT8, BASE_DEC, NULL, 0,
"Algorithm #1", HFILL }},
{ &hf_wcp_alg_b,
{ "Alg 2", "wcp.alg2", FT_UINT8, BASE_DEC, NULL, 0,
"Algorithm #2", HFILL }},
{ &hf_wcp_alg_c,
{ "Alg 3", "wcp.alg3", FT_UINT8, BASE_DEC, NULL, 0,
"Algorithm #3", HFILL }},
{ &hf_wcp_alg_d,
{ "Alg 4", "wcp.alg4", FT_UINT8, BASE_DEC, NULL, 0,
"Algorithm #4", HFILL }},
{ &hf_wcp_alg,
{ "Alg", "wcp.alg", FT_UINT8, BASE_DEC, NULL, 0,
"Algorithm", HFILL }},
#if 0
{ &hf_wcp_rexmit,
{ "Rexmit", "wcp.rexmit", FT_UINT8, BASE_DEC, NULL, 0,
"Retransmit", HFILL }},
#endif
{ &hf_wcp_hist_size,
{ "History", "wcp.hist", FT_UINT8, BASE_DEC, NULL, 0,
"History Size", HFILL }},
{ &hf_wcp_ppc,
{ "PerPackComp", "wcp.ppc", FT_UINT8, BASE_DEC, NULL, 0,
"Per Packet Compression", HFILL }},
{ &hf_wcp_pib,
{ "PIB", "wcp.pib", FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }},
{ &hf_wcp_compressed_data,
{ "Compressed Data", "wcp.compressed_data", FT_NONE, BASE_NONE, NULL, 0,
"Raw compressed data", HFILL }},
{ &hf_wcp_comp_bits,
{ "Compress Flag", "wcp.flag", FT_UINT8, BASE_HEX, NULL, 0,
"Compressed byte flag", HFILL }},
#if 0
{ &hf_wcp_comp_marker,
{ "Compress Marker", "wcp.mark", FT_UINT8, BASE_DEC, NULL, 0,
"Compressed marker", HFILL }},
#endif
{ &hf_wcp_offset,
{ "Source offset", "wcp.off", FT_UINT16, BASE_HEX, NULL, WCP_OFFSET_MASK,
"Data source offset", HFILL }},
{ &hf_wcp_short_len,
{ "Compress Length", "wcp.short_len", FT_UINT8, BASE_HEX, NULL, 0xf0,
"Compressed length", HFILL }},
{ &hf_wcp_long_len,
{ "Compress Length", "wcp.long_len", FT_UINT8, BASE_HEX, NULL, 0,
"Compressed length", HFILL }},
{ &hf_wcp_long_run,
{ "Long Compression", "wcp.long_comp", FT_BYTES, BASE_NONE, NULL, 0,
"Long Compression type", HFILL }},
{ &hf_wcp_short_run,
{ "Short Compression", "wcp.short_comp", FT_BYTES, BASE_NONE, NULL, 0,
"Short Compression type", HFILL }},
};
static gint *ett[] = {
&ett_wcp,
&ett_wcp_comp_data,
&ett_wcp_field,
};
static ei_register_info ei[] = {
{ &ei_wcp_compressed_data_exceeds, { "wcp.compressed_data.exceeds", PI_MALFORMED, PI_ERROR, "Compressed data exceeds maximum buffer length", EXPFILL }},
{ &ei_wcp_uncompressed_data_exceeds, { "wcp.uncompressed_data.exceeds", PI_MALFORMED, PI_ERROR, "Uncompressed data exceeds maximum buffer length", EXPFILL }},
{ &ei_wcp_invalid_window_offset, { "wcp.off.invalid", PI_MALFORMED, PI_ERROR, "Offset points outside of visible window", EXPFILL }},
{ &ei_wcp_buffer_too_long, { "wcp.buffer_too_long", PI_MALFORMED, PI_ERROR, "Buffer too long", EXPFILL }},
#if 0
{ &ei_wcp_invalid_match_length, { "wcp.len.invalid", PI_MALFORMED, PI_ERROR, "Length greater than offset", EXPFILL }},
#endif
};
expert_module_t* expert_wcp;
proto_wcp = proto_register_protocol ("Wellfleet Compression", "WCP", "wcp");
proto_register_field_array (proto_wcp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_wcp = expert_register_protocol(proto_wcp);
expert_register_field_array(expert_wcp, ei, array_length(ei));
}
void
proto_reg_handoff_wcp(void) {
dissector_handle_t wcp_handle;
/*
* Get handle for the Frame Relay (uncompressed) dissector.
*/
fr_uncompressed_handle = find_dissector_add_dependency("fr_uncompressed", proto_wcp);
wcp_handle = create_dissector_handle(dissect_wcp, proto_wcp);
dissector_add_uint("fr.nlpid", NLPID_COMPRESSED, wcp_handle);
dissector_add_uint("ethertype", ETHERTYPE_WCP, wcp_handle);
}
/*
* Editor modelines - https://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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