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wireshark/epan/dissectors/packet-dcp-etsi.c

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/* packet-dcp-etsi.c
* Routines for ETSI Distribution & Communication Protocol
* Copyright 2006, British Broadcasting Corporation
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* Protocol info
* Ref: ETSI DCP (ETSI TS 102 821)
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/reassemble.h>
#include <epan/crc16-tvb.h>
#include <epan/reedsolomon.h>
/* forward reference */
void proto_register_dcp_etsi(void);
void proto_reg_handoff_dcp_etsi(void);
static int dissect_af (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data);
static int dissect_pft (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data);
static dissector_handle_t dcp_etsi_handle;
static dissector_table_t dcp_dissector_table;
static dissector_table_t af_dissector_table;
static dissector_table_t tpl_dissector_table;
static int proto_dcp_etsi = -1;
static int proto_af = -1;
static int proto_pft = -1;
static int proto_tpl = -1;
static int hf_edcp_sync = -1;
static int hf_edcp_len = -1;
static int hf_edcp_seq = -1;
static int hf_edcp_crcflag = -1;
static int hf_edcp_maj = -1;
static int hf_edcp_min = -1;
static int hf_edcp_pt = -1;
static int hf_edcp_crc = -1;
static int hf_edcp_crc_ok = -1;
/* static int hf_edcp_pft_pt = -1; */
static int hf_edcp_pseq = -1;
static int hf_edcp_findex = -1;
static int hf_edcp_fcount = -1;
static int hf_edcp_fecflag = -1;
static int hf_edcp_addrflag = -1;
static int hf_edcp_plen = -1;
static int hf_edcp_rsk = -1;
static int hf_edcp_rsz = -1;
static int hf_edcp_source = -1;
static int hf_edcp_dest = -1;
static int hf_edcp_hcrc = -1;
static int hf_edcp_hcrc_ok = -1;
/* static int hf_edcp_c_max = -1; */
/* static int hf_edcp_rx_min = -1; */
/* static int hf_edcp_rs_corrected = -1; */
static int hf_edcp_rs_ok = -1;
static int hf_edcp_pft_payload = -1;
static int hf_tpl_tlv = -1;
/* static int hf_tpl_ptr = -1; */
static int hf_edcp_fragments = -1;
static int hf_edcp_fragment = -1;
static int hf_edcp_fragment_overlap = -1;
static int hf_edcp_fragment_overlap_conflicts = -1;
static int hf_edcp_fragment_multiple_tails = -1;
static int hf_edcp_fragment_too_long_fragment = -1;
static int hf_edcp_fragment_error = -1;
static int hf_edcp_fragment_count = -1;
static int hf_edcp_reassembled_in = -1;
static int hf_edcp_reassembled_length = -1;
/* Initialize the subtree pointers */
static gint ett_edcp = -1;
static gint ett_af = -1;
static gint ett_pft = -1;
static gint ett_tpl = -1;
static gint ett_edcp_fragment = -1;
static gint ett_edcp_fragments = -1;
static expert_field ei_edcp_reassembly = EI_INIT;
static expert_field ei_edcp_reassembly_info = EI_INIT;
static reassembly_table dcp_reassembly_table;
static const fragment_items dcp_frag_items = {
/* Fragment subtrees */
&ett_edcp_fragment,
&ett_edcp_fragments,
/* Fragment fields */
&hf_edcp_fragments,
&hf_edcp_fragment,
&hf_edcp_fragment_overlap,
&hf_edcp_fragment_overlap_conflicts,
&hf_edcp_fragment_multiple_tails,
&hf_edcp_fragment_too_long_fragment,
&hf_edcp_fragment_error,
&hf_edcp_fragment_count,
/* Reassembled in field */
&hf_edcp_reassembled_in,
/* Reassembled length field */
&hf_edcp_reassembled_length,
/* Reassembled data field */
NULL,
/* Tag */
"Message fragments"
};
/** Dissect a DCP packet. Details follow
* here.
* \param[in,out] tvb The buffer containing the packet
* \param[in,out] pinfo The packet info structure
* \param[in,out] tree The structure containing the details which will be displayed, filtered, etc.
static void
*/
static int
dissect_dcp_etsi(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void * data _U_)
{
guint8 *sync;
proto_tree *dcp_tree;
proto_item *ti;
if(tvb_captured_length(tvb) < 11)
return FALSE;
/* Clear out stuff in the info column */
col_clear(pinfo->cinfo, COL_INFO);
col_set_str (pinfo->cinfo, COL_PROTOCOL, "DCP (ETSI)");
/*col_append_fstr (pinfo->cinfo, COL_INFO, " tvb %d", tvb_length(tvb));*/
ti = proto_tree_add_item (tree, proto_dcp_etsi, tvb, 0, -1, ENC_NA);
dcp_tree = proto_item_add_subtree (ti, ett_edcp);
sync = tvb_get_string_enc(pinfo->pool, tvb, 0, 2, ENC_ASCII);
dissector_try_string(dcp_dissector_table, (char*)sync, tvb, pinfo, dcp_tree, NULL);
return tvb_captured_length(tvb);
}
/** Heuristic dissector for a DCP packet.
* \param[in,out] tvb The buffer containing the packet
* \param[in,out] pinfo The packet info structure
* \param[in,out] tree The structure containing the details which will be displayed, filtered, etc.
static void
*/
static gboolean
dissect_dcp_etsi_heur(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void * data _U_)
{
/* 6.1 AF packet structure
*
* AF Header
* SYNC LEN SEQ AR PT
* 2 bytes 4 bytes 2 bytes 1 byte 1 byte
*
* SYNC: two-byte ASCII representation of "AF".
* LEN: length of the payload, in bytes.
* SEQ: sequence number
* AR: AF protocol Revision - a field combining the CF, MAJ and MIN fields
* CF: CRC Flag, 0 if the CRC field is not used
* MAJ: major revision of the AF protocol in use, see clause 6.2.
* MIN: minor revision of the AF protocol in use, see clause 6.2.
* Protocol Type (PT): single byte encoding the protocol of the data carried in the payload.
* For TAG Packets, the value shall be the ASCII representation of "T".
*
* 7.1 PFT fragment structure
* PFT Header
* 14, 16, 18 or 20 bytes (depending on options) Optional present if FEC=1 Optional present if Addr = 1
* Psync Pseq Findex Fcount FEC HCRC Addr Plen | RSk RSz | Source Dest
* 16 bits 16 bits 24 bits 24 bits 1 bit 16 bits 1 bit 14 bits | 8 bits 8 bits | 16 bits 16 bits
*
* Psync: the ASCII string "PF" is used as the synchronization word for the PFT Layer
*
* Don't accept this packet unless at least a full AF header present(10 bytes).
* It should be possible to strengthen the heuristic further if need be.
*/
guint16 word;
if(tvb_captured_length(tvb) < 11)
return FALSE;
word = tvb_get_ntohs(tvb,0);
/* Check for 'AF or 'PF' */
if (word == 0x4146) {
/* AF - check the version, which is only major 1, minor 0 */
if ((tvb_get_guint8(tvb, 8) & 0x7F) != 0x10) {
return FALSE;
}
/* Tag packets are the only payload type */
if (tvb_get_guint8(tvb, 9) != 'T') {
return FALSE;
}
} else if (word == 0x5046) {
/* PFT - header length 14, 16, 18, or 20 depending on options.
* Always contains CRC. */
if (tvb_captured_length(tvb) < 14) {
return FALSE;
}
guint16 plen = tvb_get_ntohs(tvb, 10);
guint header_len = 14;
if (plen & 0x8000) {
header_len += 2;
}
if (plen & 0x4000) {
header_len += 4;
}
if (tvb_captured_length(tvb) < header_len) {
return FALSE;
}
if (crc16_x25_ccitt_tvb(tvb, header_len) != 0x1D0F) {
return FALSE;
}
} else {
return FALSE;
}
dissect_dcp_etsi(tvb, pinfo, tree, data);
return TRUE;
}
#define PFT_RS_N_MAX 207
#define PFT_RS_K 255
#define PFT_RS_P (PFT_RS_K - PFT_RS_N_MAX)
static
void rs_deinterleave(const guint8 *input, guint8 *output, guint16 plen, guint32 fcount)
{
guint fidx;
for(fidx=0; fidx<fcount; fidx++)
{
int r;
for (r=0; r<plen; r++)
{
output[fidx+r*fcount] = input[fidx*plen+r];
}
}
}
static
gboolean rs_correct_data(guint8 *deinterleaved, guint8 *output,
guint32 c_max, guint16 rsk, guint16 rsz _U_)
{
guint32 i, index_coded = 0, index_out = 0;
int err_corr;
for (i=0; i<c_max; i++)
{
memcpy(output+index_out, deinterleaved+index_coded, rsk);
index_coded += rsk;
memcpy(output+index_out+PFT_RS_N_MAX, deinterleaved+index_coded, PFT_RS_P);
index_coded += PFT_RS_P;
err_corr = eras_dec_rs(output+index_out, NULL, 0);
if (err_corr<0) {
return FALSE;
}
index_out += rsk;
}
return TRUE;
}
/* Don't attempt reassembly if we have a huge number of fragments. */
#define MAX_FRAGMENTS ((1 * 1024 * 1024) / sizeof(guint32))
/* If we missed more than this number of consecutive fragments,
we don't attempt reassembly */
#define MAX_FRAG_GAP 1000
static tvbuff_t *
dissect_pft_fec_detailed(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
guint32 findex _U_,
guint32 fcount,
guint16 seq,
gint offset,
guint16 plen,
gboolean fec _U_,
guint16 rsk,
guint16 rsz,
fragment_head *fdx
)
{
guint32 decoded_size;
guint32 c_max;
guint32 rx_min;
tvbuff_t *new_tvb=NULL;
if (fcount > MAX_FRAGMENTS) {
proto_tree_add_expert_format(tree, pinfo, &ei_edcp_reassembly, tvb , 0, -1, "[Reassembly of %d fragments not attempted]", fcount);
return NULL;
}
decoded_size = fcount*plen;
c_max = fcount*plen/(rsk+PFT_RS_P); /* rounded down */
rx_min = fcount - (c_max*PFT_RS_P/plen);
if (fdx)
new_tvb = process_reassembled_data (tvb, offset, pinfo,
"Reassembled DCP (ETSI)",
fdx, &dcp_frag_items,
NULL, tree);
else {
guint fragments=0;
guint32 *got;
fragment_item *fd;
fragment_head *fd_head;
proto_tree_add_expert_format(tree, pinfo, &ei_edcp_reassembly_info, tvb, 0, -1, "want %d, got %d need %d",
fcount, fragments, rx_min);
got = (guint32 *)wmem_alloc(pinfo->pool, fcount*sizeof(guint32));
/* make a list of the findex (offset) numbers of the fragments we have */
fd_head = fragment_get(&dcp_reassembly_table, pinfo, seq, NULL);
if (fd_head) {
for (fd = fd_head->next; fd != NULL && fragments < fcount; fd = fd->next) {
if(fd->tvb_data) {
got[fragments++] = fd->offset; /* this is the findex of the fragment */
}
}
}
/* have we got enough for Reed Solomon to try to correct ? */
if(fragments>=rx_min) { /* yes, in theory */
guint i,current_findex;
fragment_head *frag=NULL;
guint8 *dummy_data = (guint8*) wmem_alloc0 (pinfo->pool, plen);
tvbuff_t *dummytvb = tvb_new_real_data(dummy_data, plen, plen);
/* try and decode with missing fragments */
proto_tree_add_expert_format(tree, pinfo, &ei_edcp_reassembly_info, tvb, 0, -1, "want %d, got %d need %d",
fcount, fragments, rx_min);
/* fill the fragment table with empty fragments */
current_findex = 0;
for(i=0; i<fragments; i++) {
guint next_fragment_we_have = got[i];
if (next_fragment_we_have > MAX_FRAGMENTS) {
proto_tree_add_expert_format(tree, pinfo, &ei_edcp_reassembly, tvb , 0, -1, "[Reassembly of %d fragments not attempted]", next_fragment_we_have);
return NULL;
}
if (next_fragment_we_have-current_findex > MAX_FRAG_GAP) {
proto_tree_add_expert_format(tree, pinfo, &ei_edcp_reassembly, tvb, 0, -1,
"[Missing %d consecutive packets. Don't attempt reassembly]",
next_fragment_we_have-current_findex);
return NULL;
}
for(; current_findex<next_fragment_we_have; current_findex++) {
frag = fragment_add_seq_check (&dcp_reassembly_table,
dummytvb, 0, pinfo, seq, NULL,
current_findex, plen, (current_findex+1!=fcount));
}
current_findex++; /* skip over the fragment we have */
}
tvb_free(dummytvb);
if(frag)
new_tvb = process_reassembled_data (tvb, offset, pinfo,
"Reassembled DCP (ETSI)",
frag, &dcp_frag_items,
NULL, tree);
}
}
if(new_tvb && tvb_captured_length(new_tvb) > 0) {
gboolean decoded;
tvbuff_t *dtvb = NULL;
const guint8 *input = tvb_get_ptr(new_tvb, 0, -1);
guint32 reassembled_size = tvb_captured_length(new_tvb);
guint8 *deinterleaved = (guint8*) wmem_alloc(pinfo->pool, reassembled_size);
guint8 *output = (guint8*) wmem_alloc(pinfo->pool, decoded_size);
rs_deinterleave(input, deinterleaved, plen, fcount);
dtvb = tvb_new_child_real_data(tvb, deinterleaved, reassembled_size, reassembled_size);
add_new_data_source(pinfo, dtvb, "Deinterleaved");
decoded = rs_correct_data(deinterleaved, output, c_max, rsk, rsz);
proto_tree_add_boolean (tree, hf_edcp_rs_ok, tvb, offset, 2, decoded);
new_tvb = tvb_new_child_real_data(dtvb, output, decoded_size, decoded_size);
add_new_data_source(pinfo, new_tvb, "RS Error Corrected Data");
}
return new_tvb;
}
/** Handle a PFT packet which has the fragmentation header. This uses the
* standard wireshark methods for reassembling fragments. If FEC is used,
* the FEC is handled too. For the moment, all the fragments must be
* available but this could be improved.
* \param[in,out] tvb The buffer containing the current fragment
* \param[in,out] pinfo The packet info structure
* \param[in,out] tree The structure containing the details which will be displayed, filtered, etc.
* \param[in] findex the fragment count
* \param[in] fcount the number of fragments
* \param[in] seq the sequence number of the reassembled packet
* \param[in] offset the offset into the tvb of the fragment
* \param[in] plen the length of each fragment
* \param[in] fec is fec used
* \param[in] rsk the number of useful bytes in each chunk
* \param[in] rsz the number of padding bytes in each chunk
*/
static tvbuff_t *
dissect_pft_fragmented(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
guint32 findex,
guint32 fcount,
guint16 seq,
gint offset,
guint16 plen,
gboolean fec,
guint16 rsk,
guint16 rsz
)
{
gboolean first, last;
tvbuff_t *new_tvb=NULL;
fragment_head *frag_edcp = NULL;
pinfo->fragmented = TRUE;
first = findex == 0;
last = fcount == (findex+1);
frag_edcp = fragment_add_seq_check (
&dcp_reassembly_table,
tvb, offset,
pinfo, seq, NULL,
findex,
plen,
!last);
if(fec) {
new_tvb = dissect_pft_fec_detailed(
tvb, pinfo, tree, findex, fcount, seq, offset, plen, fec, rsk, rsz, frag_edcp
);
} else {
new_tvb = process_reassembled_data (tvb, offset, pinfo,
"Reassembled DCP (ETSI)",
frag_edcp, &dcp_frag_items,
NULL, tree);
}
if(new_tvb) {
col_append_str (pinfo->cinfo, COL_INFO, " (Message Reassembled)");
} else {
if(last) {
col_append_str (pinfo->cinfo, COL_INFO, " (Message Reassembly failure)");
} else {
col_append_fstr (pinfo->cinfo, COL_INFO, " (Message fragment %u)", findex);
}
}
if(first)
col_append_str (pinfo->cinfo, COL_INFO, " (first)");
if(last)
col_append_str (pinfo->cinfo, COL_INFO, " (last)");
return new_tvb;
}
/** Dissect a PFT packet. Details follow
* here.
* \param[in,out] tvb The buffer containing the packet
* \param[in,out] pinfo The packet info structure
* \param[in,out] tree The structure containing the details which will be displayed, filtered, etc.
*/
static int
dissect_pft(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data)
{
guint16 plen;
gint offset = 0;
guint16 seq, payload_len;
guint32 findex, fcount;
proto_tree *pft_tree;
proto_item *ti, *li;
tvbuff_t *next_tvb = NULL;
gboolean fec = FALSE;
guint16 rsk=0, rsz=0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DCP-PFT");
ti = proto_tree_add_item (tree, proto_pft, tvb, 0, -1, ENC_NA);
pft_tree = proto_item_add_subtree (ti, ett_pft);
proto_tree_add_item (pft_tree, hf_edcp_sync, tvb, offset, 2, ENC_ASCII);
offset += 2;
seq = tvb_get_ntohs (tvb, offset);
proto_tree_add_item (pft_tree, hf_edcp_pseq, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
findex = tvb_get_ntoh24 (tvb, offset);
proto_tree_add_item (pft_tree, hf_edcp_findex, tvb, offset, 3, ENC_BIG_ENDIAN);
offset += 3;
fcount = tvb_get_ntoh24 (tvb, offset);
proto_tree_add_item (pft_tree, hf_edcp_fcount, tvb, offset, 3, ENC_BIG_ENDIAN);
offset += 3;
plen = tvb_get_ntohs (tvb, offset);
payload_len = plen & 0x3fff;
proto_tree_add_item (pft_tree, hf_edcp_fecflag, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item (pft_tree, hf_edcp_addrflag, tvb, offset, 2, ENC_BIG_ENDIAN);
li = proto_tree_add_item (pft_tree, hf_edcp_plen, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
if (plen & 0x8000) {
fec = TRUE;
rsk = tvb_get_guint8 (tvb, offset);
proto_tree_add_item (pft_tree, hf_edcp_rsk, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
rsz = tvb_get_guint8 (tvb, offset);
proto_tree_add_item (pft_tree, hf_edcp_rsz, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
}
if (plen & 0x4000) {
proto_tree_add_item (pft_tree, hf_edcp_source, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item (pft_tree, hf_edcp_dest, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
}
if (tree) {
proto_item *ci = NULL;
guint header_len = offset+2;
guint16 c = crc16_x25_ccitt_tvb(tvb, header_len);
ci = proto_tree_add_item (pft_tree, hf_edcp_hcrc, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_item_append_text(ci, " (%s)", (c==0x1D0F)?"Ok":"bad");
proto_tree_add_boolean(pft_tree, hf_edcp_hcrc_ok, tvb, offset, 2, c==0x1D0F);
}
offset += 2;
if (fcount > 1) { /* fragmented*/
gboolean save_fragmented = pinfo->fragmented;
guint16 real_len = tvb_captured_length(tvb)-offset;
proto_tree_add_item (pft_tree, hf_edcp_pft_payload, tvb, offset, real_len, ENC_NA);
if(real_len != payload_len || real_len == 0) {
proto_item_append_text(li, " (length error (%d))", real_len);
}
else {
next_tvb = dissect_pft_fragmented(tvb, pinfo, pft_tree, findex, fcount,
seq, offset, real_len, fec, rsk, rsz);
}
pinfo->fragmented = save_fragmented;
} else {
next_tvb = tvb_new_subset_remaining (tvb, offset);
}
if(next_tvb) {
dissect_af(next_tvb, pinfo, tree, data);
}
return tvb_captured_length(tvb);
}
/** Dissect an AF Packet. Parse an AF packet, checking the CRC if the CRC valid
* flag is set and calling any registered sub dissectors on the payload type.
* Currently only a payload type 'T' is defined which is the tag packet layer.
* If any others are defined then they can register themselves.
* \param[in,out] tvb The buffer containing the packet
* \param[in,out] pinfo The packet info structure
* \param[in,out] tree The structure containing the details which will be displayed, filtered, etc.
*/
static int
dissect_af (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data _U_)
{
gint offset = 0;
proto_item *ti;
proto_item *li = NULL;
proto_item *ci;
proto_tree *af_tree;
guint8 ver, pt;
guint32 payload_len;
tvbuff_t *next_tvb = NULL;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DCP-AF");
ti = proto_tree_add_item (tree, proto_af, tvb, 0, -1, ENC_NA);
af_tree = proto_item_add_subtree (ti, ett_af);
proto_tree_add_item (af_tree, hf_edcp_sync, tvb, offset, 2, ENC_ASCII);
offset += 2;
payload_len = tvb_get_ntohl(tvb, offset);
if (tree) {
guint32 real_payload_len = tvb_captured_length(tvb)-12;
li = proto_tree_add_item (af_tree, hf_edcp_len, tvb, offset, 4, ENC_BIG_ENDIAN);
if(real_payload_len < payload_len) {
proto_item_append_text (li, " (wrong len claims %d is %d)",
payload_len, real_payload_len
);
} else if(real_payload_len > payload_len) {
proto_item_append_text (li, " (%d bytes in packet after end of AF frame)",
real_payload_len-payload_len
);
}
}
offset += 4;
proto_tree_add_item (af_tree, hf_edcp_seq, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
ver = tvb_get_guint8 (tvb, offset);
proto_tree_add_item (af_tree, hf_edcp_crcflag, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item (af_tree, hf_edcp_maj, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item (af_tree, hf_edcp_min, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
pt = tvb_get_guint8 (tvb, offset);
proto_tree_add_item (af_tree, hf_edcp_pt, tvb, offset, 1, ENC_ASCII);
offset += 1;
next_tvb = tvb_new_subset_length_caplen (tvb, offset, payload_len, payload_len);
offset += payload_len;
ci = proto_tree_add_item (af_tree, hf_edcp_crc, tvb, offset, 2, ENC_BIG_ENDIAN);
if (ver & 0x80) { /* crc valid */
guint len = offset+2;
guint16 c = crc16_x25_ccitt_tvb(tvb, len);
proto_item_append_text(ci, " (%s)", (c==0x1D0F)?"Ok":"bad");
proto_tree_add_boolean(af_tree, hf_edcp_crc_ok, tvb, offset, 2, c==0x1D0F);
}
/*offset += 2;*/
dissector_try_uint(af_dissector_table, pt, next_tvb, pinfo, tree);
return tvb_captured_length(tvb);
}
/** Dissect the Tag Packet Layer.
* Split the AF packet into its tag items. Each tag item has a 4 character
* tag, a length in bits and a value. The *ptr tag is dissected in the routine.
* All other tags are listed and may be handled by other dissectors.
* Child dissectors are tied to the parent tree, not to this tree, so that
* they appear at the same level as DCP.
* \param[in,out] tvb The buffer containing the packet
* \param[in,out] pinfo The packet info structure
* \param[in,out] tree The structure containing the details which will be displayed, filtered, etc.
*/
static int
dissect_tpl(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data _U_)
{
proto_tree *tpl_tree;
guint offset=0;
proto_item *ti;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DCP-TPL");
ti = proto_tree_add_item (tree, proto_tpl, tvb, 0, -1, ENC_NA);
tpl_tree = proto_item_add_subtree (ti, ett_tpl);
while(offset<tvb_reported_length(tvb)) {
tvbuff_t *next_tvb;
guint32 bits;
guint32 bytes;
char *tag = (char*)tvb_get_string_enc(pinfo->pool, tvb, offset, 4, ENC_ASCII);
bits = tvb_get_ntohl(tvb, offset+4);
bytes = bits / 8;
if(bits % 8)
bytes++;
proto_tree_add_bytes_format(tpl_tree, hf_tpl_tlv, tvb,
offset, 8+bytes, NULL,
"%s (%u bits)", tag, bits);
next_tvb = tvb_new_subset_length_caplen (tvb, offset+8, bytes, bytes);
dissector_try_string(tpl_dissector_table, tag, next_tvb, pinfo, tree, NULL);
offset += (8+bytes);
}
return tvb_captured_length(tvb);
}
void
proto_reg_handoff_dcp_etsi (void)
{
dissector_handle_t af_handle;
dissector_handle_t pft_handle;
dissector_handle_t tpl_handle;
dcp_etsi_handle = register_dissector("dcp-etsi", dissect_dcp_etsi, proto_dcp_etsi);
af_handle = create_dissector_handle(dissect_af, proto_af);
pft_handle = create_dissector_handle(dissect_pft, proto_pft);
tpl_handle = create_dissector_handle(dissect_tpl, proto_tpl);
heur_dissector_add("udp", dissect_dcp_etsi_heur, "DCP (ETSI) over UDP", "dcp_etsi_udp", proto_dcp_etsi, HEURISTIC_ENABLE);
dissector_add_for_decode_as("udp.port", dcp_etsi_handle);
dissector_add_string("dcp-etsi.sync", "AF", af_handle);
dissector_add_string("dcp-etsi.sync", "PF", pft_handle);
/* if there are ever other payload types ...*/
dissector_add_uint("dcp-af.pt", 'T', tpl_handle);
}
void
proto_register_dcp_etsi (void)
{
static hf_register_info hf_edcp[] = {
{&hf_edcp_sync,
{"sync", "dcp-etsi.sync",
FT_STRING, BASE_NONE, NULL, 0,
"AF or PF", HFILL}
}
};
static hf_register_info hf_af[] = {
{&hf_edcp_len,
{"length", "dcp-af.len",
FT_UINT32, BASE_DEC, NULL, 0,
"length in bytes of the payload", HFILL}
},
{&hf_edcp_seq,
{"frame count", "dcp-af.seq",
FT_UINT16, BASE_DEC, NULL, 0,
"Logical Frame Number", HFILL}
},
{&hf_edcp_crcflag,
{"crc flag", "dcp-af.crcflag",
FT_BOOLEAN, 8, NULL, 0x80,
"Frame is protected by CRC", HFILL}
},
{&hf_edcp_maj,
{"Major Revision", "dcp-af.maj",
FT_UINT8, BASE_DEC, NULL, 0x70,
"Major Protocol Revision", HFILL}
},
{&hf_edcp_min,
{"Minor Revision", "dcp-af.min",
FT_UINT8, BASE_DEC, NULL, 0x0f,
"Minor Protocol Revision", HFILL}
},
{&hf_edcp_pt,
{"Payload Type", "dcp-af.pt",
FT_STRING, BASE_NONE, NULL, 0,
"T means Tag Packets, all other values reserved", HFILL}
},
{&hf_edcp_crc,
{"CRC", "dcp-af.crc",
FT_UINT16, BASE_HEX, NULL, 0,
NULL, HFILL}
},
{&hf_edcp_crc_ok,
{"CRC OK", "dcp-af.crc_ok",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
"AF CRC OK", HFILL}
}
};
static hf_register_info hf_pft[] = {
#if 0
{&hf_edcp_pft_pt,
{"Sub-protocol", "dcp-pft.pt",
FT_UINT8, BASE_DEC, NULL, 0,
"Always AF", HFILL}
},
#endif
{&hf_edcp_pseq,
{"Sequence No", "dcp-pft.seq",
FT_UINT16, BASE_DEC, NULL, 0,
"PFT Sequence No", HFILL}
},
{&hf_edcp_findex,
{"Fragment Index", "dcp-pft.findex",
FT_UINT24, BASE_DEC, NULL, 0,
"Index of the fragment within one AF Packet", HFILL}
},
{&hf_edcp_fcount,
{"Fragment Count", "dcp-pft.fcount",
FT_UINT24, BASE_DEC, NULL, 0,
"Number of fragments produced from this AF Packet", HFILL}
},
{&hf_edcp_fecflag,
{"FEC", "dcp-pft.fec",
FT_BOOLEAN, 16, NULL, 0x8000,
"When set the optional RS header is present", HFILL}
},
{&hf_edcp_addrflag,
{"Addr", "dcp-pft.addr",
FT_BOOLEAN, 16, NULL, 0x4000,
"When set the optional transport header is present", HFILL}
},
{&hf_edcp_plen,
{"fragment length", "dcp-pft.len",
FT_UINT16, BASE_DEC, NULL, 0x3fff,
"length in bytes of the payload of this fragment", HFILL}
},
{&hf_edcp_rsk,
{"RSk", "dcp-pft.rsk",
FT_UINT8, BASE_DEC, NULL, 0,
"The length of the Reed Solomon data word", HFILL}
},
{&hf_edcp_rsz,
{"RSz", "dcp-pft.rsz",
FT_UINT8, BASE_DEC, NULL, 0,
"The number of padding bytes in the last Reed Solomon block", HFILL}
},
{&hf_edcp_source,
{"source addr", "dcp-pft.source",
FT_UINT16, BASE_DEC, NULL, 0,
"PFT source identifier", HFILL}
},
{&hf_edcp_dest,
{"dest addr", "dcp-pft.dest",
FT_UINT16, BASE_DEC, NULL, 0,
"PFT destination identifier", HFILL}
},
{&hf_edcp_hcrc,
{"header CRC", "dcp-pft.crc",
FT_UINT16, BASE_HEX, NULL, 0,
"PFT Header CRC", HFILL}
},
{&hf_edcp_hcrc_ok,
{"PFT CRC OK", "dcp-pft.crc_ok",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
"PFT Header CRC OK", HFILL}
},
{&hf_edcp_fragments,
{"Message fragments", "dcp-pft.fragments",
FT_NONE, BASE_NONE, NULL, 0x00, NULL, HFILL}},
{&hf_edcp_fragment,
{"Message fragment", "dcp-pft.fragment",
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL}},
{&hf_edcp_fragment_overlap,
{"Message fragment overlap", "dcp-pft.fragment.overlap",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_edcp_fragment_overlap_conflicts,
{"Message fragment overlapping with conflicting data",
"dcp-pft.fragment.overlap.conflicts",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_edcp_fragment_multiple_tails,
{"Message has multiple tail fragments",
"dcp-pft.fragment.multiple_tails",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_edcp_fragment_too_long_fragment,
{"Message fragment too long", "dcp-pft.fragment.too_long_fragment",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_edcp_fragment_error,
{"Message defragmentation error", "dcp-pft.fragment.error",
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL}},
{&hf_edcp_fragment_count,
{"Message fragment count", "dcp-pft.fragment.count",
FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL}},
{&hf_edcp_reassembled_in,
{"Reassembled in", "dcp-pft.reassembled.in",
FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL}},
{&hf_edcp_reassembled_length,
{"Reassembled DCP (ETSI) length", "dcp-pft.reassembled.length",
FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL}},
#if 0
{&hf_edcp_c_max,
{"C max", "dcp-pft.cmax",
FT_UINT16, BASE_DEC, NULL, 0,
"Maximum number of RS chunks sent", HFILL}
},
{&hf_edcp_rx_min,
{"Rx min", "dcp-pft.rxmin",
FT_UINT16, BASE_DEC, NULL, 0,
"Minimum number of fragments needed for RS decode", HFILL}
},
{&hf_edcp_rs_corrected,
{"RS Symbols Corrected", "dcp-pft.rs_corrected",
FT_INT16, BASE_DEC, NULL, 0,
"Number of symbols corrected by RS decode or -1 for failure", HFILL}
},
#endif
{&hf_edcp_rs_ok,
{"RS decode OK", "dcp-pft.rs_ok",
FT_BOOLEAN, BASE_NONE, NULL, 0x0,
"successfully decoded RS blocks", HFILL}
},
{&hf_edcp_pft_payload,
{"payload", "dcp-pft.payload",
FT_BYTES, BASE_NONE, NULL, 0,
"PFT Payload", HFILL}
}
};
static hf_register_info hf_tpl[] = {
{&hf_tpl_tlv,
{"tag", "dcp-tpl.tlv",
FT_BYTES, BASE_NONE, NULL, 0,
"Tag Packet", HFILL}
},
#if 0
{&hf_tpl_ptr,
{"Type", "dcp-tpl.ptr",
FT_STRING, BASE_NONE, NULL, 0,
"Protocol Type & Revision", HFILL}
}
#endif
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_edcp,
&ett_af,
&ett_pft,
&ett_tpl,
&ett_edcp_fragment,
&ett_edcp_fragments
};
static ei_register_info ei[] = {
{ &ei_edcp_reassembly, { "dcp-etsi.reassembly_failed", PI_REASSEMBLE, PI_ERROR, "Reassembly failed", EXPFILL }},
{ &ei_edcp_reassembly_info, { "dcp-etsi.reassembly_info", PI_REASSEMBLE, PI_CHAT, "Reassembly information", EXPFILL }},
};
expert_module_t* expert_dcp_etsi;
proto_dcp_etsi = proto_register_protocol ("ETSI Distribution & Communication Protocol (for DRM)", /* name */
"DCP (ETSI)", /* short name */
"dcp-etsi" /* abbrev */
);
proto_af = proto_register_protocol ("DCP Application Framing Layer", "DCP-AF", "dcp-af");
proto_pft = proto_register_protocol ("DCP Protection, Fragmentation & Transport Layer", "DCP-PFT", "dcp-pft");
proto_tpl = proto_register_protocol ("DCP Tag Packet Layer", "DCP-TPL", "dcp-tpl");
proto_register_field_array (proto_dcp_etsi, hf_edcp, array_length (hf_edcp));
proto_register_field_array (proto_af, hf_af, array_length (hf_af));
proto_register_field_array (proto_pft, hf_pft, array_length (hf_pft));
proto_register_field_array (proto_tpl, hf_tpl, array_length (hf_tpl));
proto_register_subtree_array (ett, array_length (ett));
expert_dcp_etsi = expert_register_protocol(proto_dcp_etsi);
expert_register_field_array(expert_dcp_etsi, ei, array_length(ei));
/* subdissector code */
dcp_dissector_table = register_dissector_table("dcp-etsi.sync",
"DCP Sync", proto_dcp_etsi, FT_STRING, BASE_NONE);
af_dissector_table = register_dissector_table("dcp-af.pt",
"DCP-AF Payload Type", proto_dcp_etsi, FT_UINT8, BASE_DEC);
tpl_dissector_table = register_dissector_table("dcp-tpl.ptr",
"DCP-TPL Protocol Type & Revision", proto_dcp_etsi, FT_STRING, BASE_NONE);
reassembly_table_register (&dcp_reassembly_table,
&addresses_reassembly_table_functions);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/
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