216 lines
5.8 KiB
C
216 lines
5.8 KiB
C
![]() |
/* packet-rtp.c
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* Routines for RTP packet disassembly
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*
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* Jason Lango <jal@netapp.com>
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*
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* $Id: packet-rtp.c,v 1.1 2000/04/21 01:45:56 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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* Copyright 1998 Gerald Combs
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*
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*/
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#include "config.h"
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#ifdef HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif
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#ifdef HAVE_NETINET_IN_H
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#include <netinet/in.h>
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#endif
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#include <string.h>
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#include <ctype.h>
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#include <stddef.h>
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#include <glib.h>
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#include "packet.h"
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#include "packet-rtp.h"
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static int proto_rtp = -1;
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static gint ett_rtp = -1;
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#define _RTP_FLAG_BITS(hdr, s, n) \
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((u_int)(((hdr)->rtp_flag_bits >> (8 - (s) - (n))) & ((1 << (n)) - 1)))
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#define RTP_VERSION(hdr) _RTP_FLAG_BITS(hdr, 0, 2)
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#define RTP_PADDING(hdr) _RTP_FLAG_BITS(hdr, 2, 1)
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#define RTP_EXTENSION(hdr) _RTP_FLAG_BITS(hdr, 3, 1)
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#define RTP_CSRC_COUNT(hdr) _RTP_FLAG_BITS(hdr, 4, 4)
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#define RTP_MARKER(hdr) ((u_int)((hdr)->rtp_type_bits >> 7))
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#define RTP_PAYLOAD_TYPE(hdr) ((u_int)((hdr)->rtp_type_bits & 0x7F))
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typedef struct rtp_hdr {
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guint8 rtp_flag_bits;
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guint8 rtp_type_bits;
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guint16 rtp_seq;
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guint32 rtp_timestamp;
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guint32 rtp_ssrc;
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} rtp_hdr_t;
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typedef struct rtp_hdr_ext {
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guint16 rtp_ext_app; /* defined by RTP profile */
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guint16 rtp_ext_length; /* length of extension data in 32 bit words */
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} rtp_hdr_ext_t;
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void
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dissect_rtp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
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{
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proto_tree *rtp_tree;
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proto_item *ti;
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const u_char *data, *dataend;
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rtp_hdr_t hdr;
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int end_offset;
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int ii;
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guint32 *csrc_ptr;
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rtp_hdr_ext_t ext;
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data = &pd[offset];
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dataend = data + END_OF_FRAME;
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end_offset = offset + END_OF_FRAME;
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memcpy(&hdr, data, END_OF_FRAME < sizeof(rtp_hdr_t) ?
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END_OF_FRAME : sizeof(rtp_hdr_t));
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hdr.rtp_seq = ntohs(hdr.rtp_seq);
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hdr.rtp_timestamp = ntohl(hdr.rtp_timestamp);
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hdr.rtp_ssrc = ntohl(hdr.rtp_ssrc);
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if (check_col(fd, COL_PROTOCOL))
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col_add_str(fd, COL_PROTOCOL, "RTP");
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if (check_col(fd, COL_INFO)) {
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col_add_fstr(fd, COL_INFO, "SSRC: %lu %sPayload: %u Seq: %u",
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(u_long) hdr.rtp_ssrc,
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RTP_MARKER(&hdr) ? "*Mark* " : "",
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(u_int) RTP_PAYLOAD_TYPE(&hdr),
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(u_int) hdr.rtp_seq);
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}
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rtp_tree = NULL;
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if (tree) {
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ti = proto_tree_add_item(tree, proto_rtp, offset, END_OF_FRAME,
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NULL);
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rtp_tree = proto_item_add_subtree(ti, ett_rtp);
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}
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if (!rtp_tree)
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return;
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if (offset >= end_offset)
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goto bad_len;
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proto_tree_add_text(rtp_tree, offset, 1, "Version: %u (%s)",
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RTP_VERSION(&hdr),
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RTP_VERSION(&hdr) == 3 ? "New Unknown Version" :
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RTP_VERSION(&hdr) == 2 ? "RFC 1889 Version" :
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RTP_VERSION(&hdr) == 1 ? "First Draft Version" :
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"Old Vat Version");
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proto_tree_add_text(rtp_tree, offset, 1, "Padding: %u",
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RTP_PADDING(&hdr));
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proto_tree_add_text(rtp_tree, offset, 1, "Extension: %u",
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RTP_EXTENSION(&hdr));
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proto_tree_add_text(rtp_tree, offset, 1, "CSRC Count: %u",
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RTP_CSRC_COUNT(&hdr));
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offset++;
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if (offset >= end_offset)
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goto bad_len;
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proto_tree_add_text(rtp_tree, offset, 1, "Marker: %u",
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RTP_MARKER(&hdr));
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proto_tree_add_text(rtp_tree, offset, 1, "Payload Type: %u",
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RTP_PAYLOAD_TYPE(&hdr));
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offset++;
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if (offset >= end_offset)
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goto bad_len;
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proto_tree_add_text(rtp_tree, offset, 2, "Seq: %u",
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(u_int) hdr.rtp_seq);
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offset += 2;
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if (offset >= end_offset)
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goto bad_len;
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proto_tree_add_text(rtp_tree, offset, 4, "Timestamp: %lu",
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(u_long) hdr.rtp_timestamp);
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offset += 4;
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if (offset >= end_offset)
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goto bad_len;
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proto_tree_add_text(rtp_tree, offset, 4, "SSRC: %lu",
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(u_long) hdr.rtp_ssrc);
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offset += 4;
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csrc_ptr = (guint32*) (data + sizeof(rtp_hdr_t));
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for (ii = 0; ii < RTP_CSRC_COUNT(&hdr); ii++) {
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guint32 csrc;
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if (offset >= end_offset)
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goto bad_len;
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csrc = pntohl(csrc_ptr);
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proto_tree_add_text(rtp_tree, offset, 4, "CSRC %d: %lu",
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ii + 1, (u_long) csrc);
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offset += 4;
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csrc_ptr++;
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}
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if (RTP_EXTENSION(&hdr)) {
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memcpy(&ext, data + sizeof(rtp_hdr_t),
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END_OF_FRAME < sizeof(rtp_hdr_ext_t) ?
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END_OF_FRAME : sizeof(rtp_hdr_ext_t));
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ext.rtp_ext_app = ntohs(ext.rtp_ext_app);
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ext.rtp_ext_length = ntohs(ext.rtp_ext_length);
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proto_tree_add_text(rtp_tree, offset, 2,
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"Extension-defined: %x", (u_int) ext.rtp_ext_app);
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offset += 2;
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proto_tree_add_text(rtp_tree, offset, 2,
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"Extension length: %u", (u_int) ext.rtp_ext_length);
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offset += 2;
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proto_tree_add_text(rtp_tree, offset, 4 * ext.rtp_ext_length,
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"Extension Data (%d bytes)",
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(int) 4 * ext.rtp_ext_length);
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offset += 4 * ext.rtp_ext_length;
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}
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proto_tree_add_text(rtp_tree, offset, END_OF_FRAME,
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"Data (%d bytes)", END_OF_FRAME);
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return;
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bad_len:
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proto_tree_add_text(rtp_tree, end_offset, 0,
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"Unexpected end of packet");
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}
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void
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proto_register_rtp(void)
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{
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/* static hf_register_info hf[] = {
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{ &variable,
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{ "Name", "rtp.abbreviation", TYPE, VALS_POINTER }},
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};*/
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static gint *ett[] = {
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&ett_rtp,
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};
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proto_rtp = proto_register_protocol("Realtime Transport Protocol", "rtp");
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/* proto_register_field_array(proto_rtp, hf, array_length(hf));*/
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proto_register_subtree_array(ett, array_length(ett));
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}
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