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wireshark/packet-rtp.c
Guy Harris 43ccfd8054 Add an additional "protocol index" argument to "{old_}dissector_add()", 
"{old_}heur_dissector_add()", "{old_}conv_dissector_add()", and
"register_dissector()", so that an entry in those tables has associated
with it the protocol index of the protocol the dissector handles (or -1,
if there is no protocol index for it).

This is for future use in a number of places.

(Arguably, "proto_register_protocol()" should take a dissector pointer
as an argument, but

	1) it'd have to handle both regular and heuristic dissectors;

	2) making it take either a "dissector_t" or a union of that and
	   a "heur_dissector_t" introduces some painful header-file
	   interdependencies

so I'm punting on that for now.  As with other Ethereal internal APIs,
these APIs are subject to change in the future, at least until Ethereal
1.0 comes out....)

svn path=/trunk/; revision=2849
2001-01-09 06:32:10 +00:00

642 lines
14 KiB
C
Raw Blame History

/* packet-rtp.c
*
* Routines for RTP dissection
* RTP = Real time Transport Protocol
*
* Copyright 2000, Philips Electronics N.V.
* Written by Andreas Sikkema <andreas.sikkema@philips.com>
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@zing.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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
* This dissector tries to dissect the RTP protocol according to Annex A
* of ITU-T Recommendation H.225.0 (02/98) or RFC 1889
*
* RTP traffic is handled by an even UDP portnumber. This can be any
* port number, but there is a registered port available, port 5004
* See Annex B of ITU-T Recommendation H.225.0, section B.7
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <glib.h>
#include "packet.h"
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include <stdio.h>
#include <string.h>
#include "packet-rtp.h"
#include "packet-h261.h"
#include "conversation.h"
/* RTP header fields */
static int proto_rtp = -1;
static int hf_rtp_version = -1;
static int hf_rtp_padding = -1;
static int hf_rtp_extension = -1;
static int hf_rtp_csrc_count = -1;
static int hf_rtp_marker = -1;
static int hf_rtp_payload_type = -1;
static int hf_rtp_seq_nr = -1;
static int hf_rtp_timestamp = -1;
static int hf_rtp_ssrc = -1;
static int hf_rtp_csrc_item = -1;
static int hf_rtp_data = -1;
static int hf_rtp_padding_data = -1;
static int hf_rtp_padding_count= -1;
/* RTP header extension fields */
static int hf_rtp_prof_define = -1;
static int hf_rtp_length = -1;
static int hf_rtp_hdr_ext = -1;
/* RTP fields defining a sub tree */
static gint ett_rtp = -1;
static gint ett_csrc_list = -1;
static gint ett_hdr_ext = -1;
/*
* Fields in the first octet of the RTP header.
*/
/* Version is the first 2 bits of the first octet*/
#define RTP_VERSION(octet) ((octet) >> 6)
/* Padding is the third bit; No need to shift, because true is any value
other than 0! */
#define RTP_PADDING(octet) ((octet) & 0x20)
/* Extension bit is the fourth bit */
#define RTP_EXTENSION(octet) ((octet) & 0x10)
/* CSRC count is the last four bits */
#define RTP_CSRC_COUNT(octet) ((octet) & 0xF)
static const value_string rtp_version_vals[] =
{
{ 0, "Old VAT Version" },
{ 1, "First Draft Version" },
{ 2, "RFC 1889 Version" },
{ 0, NULL },
};
/*
* Fields in the second octet of the RTP header.
*/
/* Marker is the first bit of the second octet */
#define RTP_MARKER(octet) ((octet) & 0x80)
/* Payload type is the last 7 bits */
#define RTP_PAYLOAD_TYPE(octet) ((octet) & 0x7F)
/*
* RTP Payload types
* Table B.2 / H.225.0
*/
#define PT_PCMU 0
#define PT_PCMA 8
#define PT_G722 9
#define PT_G723 4
#define PT_G728 15
#define PT_G729 18
#define PT_H261 31
#define PT_H263 34
static const value_string rtp_payload_type_vals[] =
{
{ PT_PCMU, "ITU-T G.711 PCMU" },
{ PT_PCMA, "ITU-T G.711 PCMA" },
{ PT_G722, "ITU-T G.722" },
{ PT_G723, "ITU-T G.723" },
{ PT_G728, "ITU-T G.728" },
{ PT_G729, "ITU-T G.729" },
{ PT_H261, "ITU-T H.261" },
{ PT_H263, "ITU-T H.263" },
{ 0, NULL },
};
static address fake_addr;
static int heur_init = FALSE;
static const char rtp_proto[] = "RTP";
void rtp_add_address( const unsigned char* ip_addr, int prt )
{
address src_addr;
conversation_t* pconv = ( conversation_t* ) NULL;
src_addr.type = AT_IPv4;
src_addr.len = 4;
src_addr.data = ip_addr;
/*
* The first time the function is called let the tcp dissector
* know that we're interested in traffic
*/
if ( ! heur_init ) {
heur_dissector_add( "udp", dissect_rtp_heur, proto_rtp );
heur_init = TRUE;
}
/*
* Check if the ip address an dport combination is not
* already registered
*/
pconv = find_conversation( &src_addr, &fake_addr, PT_UDP, prt, 0, 0 );
/*
* If not, add
*/
if ( ! pconv ) {
conversation_new( &src_addr, &fake_addr, PT_UDP, (guint32) prt,
(guint32) 0, ( void * ) rtp_proto, 0 );
}
}
#if 0
static void rtp_init( void )
{
unsigned char* tmp_data;
int i;
/* Create a fake adddress... */
fake_addr.type = AT_IPv4;
fake_addr.len = 4;
tmp_data = malloc( fake_addr.len );
for ( i = 0; i < fake_addr.len; i++) {
tmp_data[i] = 0;
}
fake_addr.data = tmp_data;
}
#endif
gboolean
dissect_rtp_heur( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
{
conversation_t* pconv;
if (!proto_is_protocol_enabled(proto_rtp))
return FALSE; /* RTP has been disabled */
/* This is a heuristic dissector, which means we get all the TCP
* traffic not sent to a known dissector and not claimed by
* a heuristic dissector called before us!
* So we first check if the frame is really meant for us.
*/
if ( ( pconv = find_conversation( &pi.src, &fake_addr, pi.ptype,
pi.srcport, 0, 0 ) ) == NULL ) {
/*
* The source ip:port combination was not what we were
* looking for, check the destination
*/
if ( ( pconv = find_conversation( &pi.dst, &fake_addr,
pi.ptype, pi.destport, 0, 0 ) ) == NULL ) {
return FALSE;
}
}
/*
* An RTP conversation always contains data
*/
if ( pconv->data == NULL )
return FALSE;
/*
* An RTP conversation data always contains "RTP"
*/
if ( strcmp( pconv->data, rtp_proto ) != 0 )
return FALSE;
dissect_rtp( tvb, pinfo, tree );
return TRUE;
}
void
dissect_rtp_data( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_tree *rtp_tree, int offset, unsigned int data_len, unsigned int payload_type )
{
tvbuff_t *newtvb;
switch( payload_type ) {
case PT_H261:
/*
* What does reported length DO?
*/
newtvb = tvb_new_subset( tvb, offset, data_len, -1 );
dissect_h261(newtvb, pinfo, tree);
break;
default:
proto_tree_add_bytes( rtp_tree, hf_rtp_data, tvb, offset, data_len, tvb_get_ptr( tvb, offset, data_len ) );
break;
}
}
void
dissect_rtp( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
{
proto_item *ti = NULL;
proto_tree *rtp_tree = NULL;
proto_tree *rtp_csrc_tree = NULL;
guint8 octet;
unsigned int version;
gboolean padding_set;
gboolean extension_set;
unsigned int csrc_count;
gboolean marker_set;
unsigned int payload_type;
unsigned int i = 0;
unsigned int hdr_extension= 0;
unsigned int padding_count= 0;
unsigned int offset = 0;
guint16 seq_num;
guint32 timestamp;
guint32 sync_src;
guint32 csrc_item;
CHECK_DISPLAY_AS_DATA(proto_rtp, tvb, pinfo, tree);
pinfo->current_proto = "RTP";
/* Get the fields in the first octet */
octet = tvb_get_guint8( tvb, offset );
version = RTP_VERSION( octet );
padding_set = RTP_PADDING( octet );
extension_set = RTP_EXTENSION( octet );
csrc_count = RTP_CSRC_COUNT( octet );
/* Get the fields in the second octet */
octet = tvb_get_guint8( tvb, offset + 1 );
marker_set = RTP_MARKER( octet );
payload_type = RTP_PAYLOAD_TYPE( octet );
/* Get the subsequent fields */
seq_num = tvb_get_ntohs( tvb, offset + 2 );
timestamp = tvb_get_ntohl( tvb, offset + 4 );
sync_src = tvb_get_ntohl( tvb, offset + 8 );
if ( check_col( pinfo->fd, COL_PROTOCOL ) ) {
col_set_str( pinfo->fd, COL_PROTOCOL, "RTP" );
}
if ( check_col( pinfo->fd, COL_INFO) ) {
col_add_fstr( pinfo->fd, COL_INFO,
"Payload type=%s, SSRC=%u, Seq=%u, Time=%u%s",
val_to_str( payload_type, rtp_payload_type_vals,
"Unknown (%u)" ),
sync_src,
seq_num,
timestamp,
marker_set ? ", Mark" : "");
}
if ( tree ) {
ti = proto_tree_add_item( tree, proto_rtp, tvb, offset, tvb_length_remaining( tvb, offset ), FALSE );
rtp_tree = proto_item_add_subtree( ti, ett_rtp );
proto_tree_add_uint( rtp_tree, hf_rtp_version, tvb,
offset, 1, version );
proto_tree_add_boolean( rtp_tree, hf_rtp_padding, tvb,
offset, 1, padding_set );
proto_tree_add_boolean( rtp_tree, hf_rtp_extension, tvb,
offset, 1, extension_set );
proto_tree_add_uint( rtp_tree, hf_rtp_csrc_count, tvb,
offset, 1, csrc_count );
offset++;
proto_tree_add_boolean( rtp_tree, hf_rtp_marker, tvb, offset,
1, marker_set );
proto_tree_add_uint( rtp_tree, hf_rtp_payload_type, tvb,
offset, 1, payload_type );
offset++;
/* Sequence number 16 bits (2 octets) */
proto_tree_add_uint( rtp_tree, hf_rtp_seq_nr, tvb, offset, 2, seq_num );
offset += 2;
/* Timestamp 32 bits (4 octets) */
proto_tree_add_uint( rtp_tree, hf_rtp_timestamp, tvb, offset, 4, timestamp );
offset += 4;
/* Synchronization source identifier 32 bits (4 octets) */
proto_tree_add_uint( rtp_tree, hf_rtp_ssrc, tvb, offset, 4, sync_src );
offset += 4;
/* CSRC list*/
if ( csrc_count > 0 ) {
ti = proto_tree_add_text(rtp_tree, tvb, offset, csrc_count * 4, "Contributing Source identifiers");
rtp_csrc_tree = proto_item_add_subtree( ti, ett_csrc_list );
for (i = 0; i < csrc_count; i++ ) {
csrc_item = tvb_get_ntohl( tvb, offset );
proto_tree_add_uint_format( rtp_csrc_tree,
hf_rtp_csrc_item, tvb, offset, 4,
csrc_item,
"CSRC item %d: %u",
i, csrc_item );
offset += 4;
}
}
/* Optional RTP header extension */
if ( extension_set ) {
/* Defined by profile field is 16 bits (2 octets) */
proto_tree_add_uint( rtp_tree, hf_rtp_prof_define, tvb, offset, 2, tvb_get_ntohs( tvb, offset ) );
offset += 2;
hdr_extension = tvb_get_ntohs( tvb, offset );
proto_tree_add_uint( rtp_tree, hf_rtp_length, tvb,
offset, 2, hdr_extension);
if ( hdr_extension > 0 ) {
ti = proto_tree_add_text(rtp_tree, tvb, offset, csrc_count * 4, "Header extensions");
/* I'm re-using the old tree variable here
from the CSRC list!*/
rtp_csrc_tree = proto_item_add_subtree( ti,
ett_hdr_ext );
for (i = 0; i < hdr_extension; i++ ) {
proto_tree_add_uint( rtp_csrc_tree, hf_rtp_hdr_ext, tvb, offset, 4, tvb_get_ntohl( tvb, offset ) );
offset += 4;
}
}
}
/* Find the padding
* The padding count is found in the LAST octet of the packet
* This contains the number of octets that can be ignored at
* the end of the packet
*/
if ( padding_set ) {
padding_count = tvb_get_guint8( tvb, tvb_length( tvb ) - 1 );
if ( padding_count > 0 ) {
dissect_rtp_data( tvb, pinfo, tree, rtp_tree, offset, tvb_length( tvb ) - padding_count, payload_type );
offset = tvb_length( tvb ) - padding_count;
proto_tree_add_item( rtp_tree, hf_rtp_padding_data, tvb, offset, padding_count - 1, FALSE );
offset += padding_count - 1;
proto_tree_add_item( rtp_tree, hf_rtp_padding_count, tvb, offset, 1, FALSE );
}
else {
proto_tree_add_item( rtp_tree, hf_rtp_padding_count, tvb, tvb_length( tvb ) - 1, 1, FALSE );
}
}
else {
dissect_rtp_data( tvb, pinfo, tree, rtp_tree, offset, tvb_length_remaining( tvb, offset ) - padding_count, payload_type );
}
}
}
void
proto_register_rtp(void)
{
static hf_register_info hf[] =
{
{
&hf_rtp_version,
{
"Version",
"rtp.version",
FT_UINT8,
BASE_DEC,
VALS(rtp_version_vals),
0x0,
""
}
},
{
&hf_rtp_padding,
{
"Padding",
"rtp.padding",
FT_BOOLEAN,
BASE_NONE,
NULL,
0x0,
""
}
},
{
&hf_rtp_extension,
{
"Extension",
"rtp.ext",
FT_BOOLEAN,
BASE_NONE,
NULL,
0x0,
""
}
},
{
&hf_rtp_csrc_count,
{
"Contributing source identifiers count",
"rtp.cc",
FT_UINT8,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_marker,
{
"Marker",
"rtp.marker",
FT_BOOLEAN,
BASE_NONE,
NULL,
0x0,
""
}
},
{
&hf_rtp_payload_type,
{
"Payload type",
"rtp.p_type",
FT_UINT8,
BASE_DEC,
VALS(rtp_payload_type_vals),
0x0,
""
}
},
{
&hf_rtp_seq_nr,
{
"Sequence number",
"rtp.seq",
FT_UINT16,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_timestamp,
{
"Timestamp",
"rtp.timestamp",
FT_UINT32,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_ssrc,
{
"Synchronization Source identifier",
"rtp.ssrc",
FT_UINT32,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_prof_define,
{
"Defined by profile",
"rtp.ext.profile",
FT_UINT16,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_length,
{
"Extension length",
"rtp.ext.len",
FT_UINT16,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_csrc_item,
{
"CSRC item",
"rtp.csrc.item",
FT_UINT32,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_hdr_ext,
{
"Header extension",
"rtp.hdr_ext",
FT_UINT32,
BASE_DEC,
NULL,
0x0,
""
}
},
{
&hf_rtp_data,
{
"Payload",
"rtp.payload",
FT_BYTES,
BASE_HEX,
NULL,
0x0,
""
}
},
{
&hf_rtp_padding_data,
{
"Padding data",
"rtp.padding.data",
FT_BYTES,
BASE_HEX,
NULL,
0x0,
""
}
},
{
&hf_rtp_padding_count,
{
"Padding count",
"rtp.padding.count",
FT_UINT8,
BASE_DEC,
NULL,
0x0,
""
}
},
};
static gint *ett[] =
{
&ett_rtp,
&ett_csrc_list,
&ett_hdr_ext,
};
proto_rtp = proto_register_protocol("Real-Time Transport Protocol",
"RTP", "rtp");
proto_register_field_array(proto_rtp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
#if 0
register_init_routine( &rtp_init );
#endif
}
void
proto_reg_handoff_rtp(void)
{
/*
* Register this dissector as one that can be assigned to a
* UDP conversation.
*/
conv_dissector_add("udp", dissect_rtp, proto_rtp);
}
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