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wireshark/epan/dissectors/packet-dcp-etsi.c
Guy Harris a4c8ebc18b Don't do any Decode As stuff for dissector tables not used with Decode As. 
Have all dissector tables have a "supports Decode As" flag, which
defaults to FALSE, and which is set to TRUE if a register_decode_as()
refers to it.

When adding a dissector to a dissector table with a given key, only add
it for Decode As if the dissector table supports it.

For non-FT_STRING dissector tables, always check for multiple entries
for the same protocol with different dissectors, and report an error if
we found them.

This means there's no need for the creator of a dissector table to
specify whether duplicates of that sort should be allowed - we always do
the check when registering something for "Decode As" (in a non-FT_STRING
dissector table), and just don't bother registering anything for "Decode
As" if the dissector table doesn't support "Decode As", so there's no
check done for those dissector tables.

Change-Id: I4a1fdea3bddc2af27a65cfbca23edc99b26c0eed
Reviewed-on: https://code.wireshark.org/review/17402
Petri-Dish: Guy Harris <guy@alum.mit.edu>
Reviewed-by: Guy Harris <guy@alum.mit.edu>
2016-08-31 00:08:01 +00:00

915 lines
31 KiB
C
Raw Blame History

/* 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
*
* 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.
*
* 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_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"
};
/** initialise the DCP protocol. Details follow
* here.
*/
static void
dcp_init_protocol(void)
{
reassembly_table_init (&dcp_reassembly_table,
&addresses_reassembly_table_functions);
}
static void
dcp_cleanup_protocol(void)
{
reassembly_table_destroy(&dcp_reassembly_table);
}
/** 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 gboolean
dissect_dcp_etsi (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void * data _U_)
{
guint8 *sync;
proto_tree *dcp_tree;
proto_item *ti;
guint16 word;
/* 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.
*/
if(tvb_captured_length(tvb) < 11)
return FALSE;
word = tvb_get_ntohs(tvb,0);
/* Check for 'AF or 'PF' */
if(word != 0x4146 && word != 0x5046)
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(wmem_packet_scope(), tvb, 0, 2, ENC_ASCII);
dissector_try_string(dcp_dissector_table, (char*)sync, tvb, pinfo, dcp_tree, NULL);
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(wmem_packet_scope(), fcount*sizeof(guint32));
/* make a list of the findex (offset) numbers of the fragments we have */
fd = fragment_get(&dcp_reassembly_table, pinfo, seq, NULL);
for (fd_head = fd; fd_head != NULL && fragments < fcount; fd_head = fd_head->next) {
if(fd_head->tvb_data) {
got[fragments++] = fd_head->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 (wmem_packet_scope(), 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);
if(tree)
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|ENC_NA);
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|ENC_NA);
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|ENC_NA);
offset += 1;
next_tvb = tvb_new_subset (tvb, offset, payload_len, -1);
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;
char *prot=NULL;
proto_item *ti;
guint16 maj, min;
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)) {
guint32 bits;
guint32 bytes;
char *tag = (char*)tvb_get_string_enc(wmem_packet_scope(), tvb, offset, 4, ENC_ASCII); offset += 4;
bits = tvb_get_ntohl(tvb, offset); offset += 4;
bytes = bits / 8;
if(bits % 8)
bytes++;
if(strcmp(tag, "*ptr")==0) {
prot = (char*)tvb_get_string_enc(wmem_packet_scope(), tvb, offset, 4, ENC_ASCII);
maj = tvb_get_ntohs(tvb, offset+4);
min = tvb_get_ntohs(tvb, offset+6);
proto_tree_add_bytes_format(tpl_tree, hf_tpl_tlv, tvb,
offset-8, bytes+8, tvb_get_ptr(tvb, offset, bytes),
"%s %s rev %d.%d", tag, prot, maj, min);
} else {
proto_tree_add_bytes_format(tpl_tree, hf_tpl_tlv, tvb,
offset-8, bytes+8, tvb_get_ptr(tvb, offset, bytes),
"%s (%u bits)", tag, bits);
}
offset += bytes;
}
dissector_try_string(tpl_dissector_table, prot, tvb, pinfo, tree->parent, NULL);
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;
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, "DCP (ETSI) over UDP", "dcp_etsi_udp", proto_dcp_etsi, HEURISTIC_ENABLE);
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);
register_init_routine(dcp_init_protocol);
register_cleanup_routine(dcp_cleanup_protocol);
}
/*
* Editor modelines - http://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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