/epan/dissectors/packet-sdp.c

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/* packet-sdp.c
 * Routines for SDP packet disassembly (RFC 2327)
 *
 * Jason Lango <jal@netapp.com>
 * Liberally copied from packet-http.c, by Guy Harris <guy@alum.mit.edu>
 *
 * $Id$
 *
 * 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.
 * Ref http://www.ietf.org/rfc/rfc4566.txt?number=4566
 */

#include "config.h"

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>           /* needed to define AF_ values on Windows */
#endif

#ifdef NEED_INET_V6DEFS_H
# include "wsutil/inet_v6defs.h"
#endif

#include <glib.h>

#include <epan/packet.h>
#include <epan/strutil.h>
#include <epan/emem.h>
#include <epan/wmem/wmem.h>
#include <epan/base64.h>
#include <epan/asn1.h>
#include <epan/prefs.h>
#include <epan/expert.h>
#include <epan/tap.h>
#include <epan/rtp_pt.h>
#include <epan/show_exception.h>

#include "packet-sdp.h"
#include "packet-rtp.h"

#include "packet-rtcp.h"
#include "packet-t38.h"
#include "packet-msrp.h"
#include "packet-sprt.h"
#include "packet-per.h"
#include "packet-h245.h"
#include "packet-h264.h"
#include "packet-mp4ves.h"

static dissector_handle_t rtp_handle;
static dissector_handle_t rtcp_handle;
static dissector_handle_t t38_handle;
static dissector_handle_t sprt_handle;
static dissector_handle_t msrp_handle;
static dissector_handle_t h264_handle;
static dissector_handle_t mp4ves_handle;

static int sdp_tap = -1;

static int proto_sdp = -1;
static int proto_sprt = -1;

static const char* UNKNOWN_ENCODING = "Unknown";
static emem_tree_t *sdp_transport_reqs = NULL;
static emem_tree_t *sdp_transport_rsps = NULL;

/* preference globals */
static gboolean global_sdp_establish_conversation = TRUE;

/* Top level fields */
static int hf_protocol_version = -1;
static int hf_owner = -1;
static int hf_session_name = -1;
static int hf_session_info = -1;
static int hf_uri = -1;
static int hf_email = -1;
static int hf_phone = -1;
static int hf_connection_info = -1;
static int hf_bandwidth = -1;
static int hf_timezone = -1;
static int hf_encryption_key = -1;
static int hf_session_attribute = -1;
static int hf_media_attribute = -1;
static int hf_time = -1;
static int hf_repeat_time = -1;
static int hf_media = -1;
static int hf_media_title = -1;
static int hf_unknown = -1;
static int hf_invalid = -1;
static int hf_ipbcp_version = -1;
static int hf_ipbcp_type = -1;

/* hf_owner subfields*/
static int hf_owner_username = -1;
static int hf_owner_sessionid = -1;
static int hf_owner_version = -1;
static int hf_owner_network_type = -1;
static int hf_owner_address_type = -1;
static int hf_owner_address = -1;

/* hf_connection_info subfields */
static int hf_connection_info_network_type = -1;
static int hf_connection_info_address_type = -1;
static int hf_connection_info_connection_address = -1;
static int hf_connection_info_ttl = -1;
static int hf_connection_info_num_addr = -1;

/* hf_bandwidth subfields */
static int hf_bandwidth_modifier = -1;
static int hf_bandwidth_value = -1;

/* hf_time subfields */
static int hf_time_start = -1;
static int hf_time_stop = -1;

/* hf_repeat_time subfield */
static int hf_repeat_time_interval = -1;
static int hf_repeat_time_duration = -1;
static int hf_repeat_time_offset = -1;

/* hf_timezone subfields */
static int hf_timezone_time = -1;
static int hf_timezone_offset = -1;

/* hf_encryption_key subfields */
static int hf_encryption_key_type = -1;
static int hf_encryption_key_data = -1;

/* hf_session_attribute subfields */
static int hf_session_attribute_field = -1;
static int hf_session_attribute_value = -1;

/* hf_media subfields */
static int hf_media_media = -1;
static int hf_media_port = -1;
static int hf_media_portcount = -1;
static int hf_media_proto = -1;
static int hf_media_format = -1;

/* hf_session_attribute subfields */
static int hf_media_attribute_field = -1;
static int hf_media_attribute_value = -1;
static int hf_media_encoding_name = -1;
static int hf_media_sample_rate = -1;
static int hf_media_format_specific_parameter = -1;
static int hf_sdp_fmtp_mpeg4_profile_level_id = -1;
static int hf_sdp_fmtp_h263_profile = -1;
static int hf_sdp_fmtp_h263_level = -1;
static int hf_sdp_h264_packetization_mode = -1;
static int hf_SDPh223LogicalChannelParameters = -1;

/* hf_session_attribute hf_media_attribute subfields */
static int hf_key_mgmt_att_value = -1;
static int hf_key_mgmt_prtcl_id = -1;
static int hf_key_mgmt_data = -1;

static int hf_sdp_crypto_tag = -1;
static int hf_sdp_crypto_crypto_suite = -1;
static int hf_sdp_crypto_master_key = -1;
static int hf_sdp_crypto_master_salt = -1;
static int hf_sdp_crypto_lifetime = -1;
static int hf_sdp_crypto_mki = -1;
static int hf_sdp_crypto_mki_length = -1;

/* trees */
static int ett_sdp = -1;
static int ett_sdp_owner = -1;
static int ett_sdp_connection_info = -1;
static int ett_sdp_bandwidth = -1;
static int ett_sdp_time = -1;
static int ett_sdp_repeat_time = -1;
static int ett_sdp_timezone = -1;
static int ett_sdp_encryption_key = -1;
static int ett_sdp_session_attribute = -1;
static int ett_sdp_media = -1;
static int ett_sdp_media_attribute = -1;
static int ett_sdp_fmtp = -1;
static int ett_sdp_key_mgmt = -1;
static int ett_sdp_crypto_key_parameters = -1;

static expert_field ei_sdp_invalid_key_param = EI_INIT;
static expert_field ei_sdp_invalid_line = EI_INIT;

#define SDP_RTP_PROTO       0x00000001
#define SDP_SRTP_PROTO      0x00000002
#define SDP_T38_PROTO       0x00000004
#define SDP_MSRP_PROTO      0x00000008
#define SDP_SPRT_PROTO      0x00000010
#define SDP_IPv4            0x80000000
#define SDP_IPv6            0x40000000
#define SDP_MSRP_IPv4       0x20000000
#define SDP_VIDEO           0x10000000


#define SDP_MAX_RTP_CHANNELS 4
#define SDP_MAX_RTP_PAYLOAD_TYPES 20
#define SDP_NO_OF_PT 128
typedef struct {
  gint32 pt[SDP_MAX_RTP_PAYLOAD_TYPES];
  gint8 pt_count;
  GHashTable *rtp_dyn_payload;
  gboolean set_rtp;
} transport_media_pt_t;

typedef struct {
  enum sdp_exchange_type sdp_status;
  char  *encoding_name[SDP_NO_OF_PT];
  int    sample_rate[SDP_NO_OF_PT];
  int    media_port[SDP_MAX_RTP_CHANNELS];
  address  src_addr[SDP_MAX_RTP_CHANNELS];
  guint  proto_bitmask[SDP_MAX_RTP_CHANNELS];
  transport_media_pt_t media[SDP_MAX_RTP_CHANNELS];
  gint8  media_count;
  /* SRTP related info XXX note currently we only handle one crypto line in the SDP
   * We should probably handle offer/answer and session updates etc(SIP) quite possibly the whole handling of
   * seting up the RTP conversations should be done by the signaling protocol(s) calling the SDP dissector
   * and the SDP dissector just provide the relevant data.
   */
  guint  encryption_algorithm;
  guint  auth_algorithm;
  guint  mki_len;                /* number of octets used for the MKI in the RTP payload */
  guint  auth_tag_len;           /* number of octets used for the Auth Tag in the RTP payload */
} transport_info_t;

/* Data that is retrieved from a packet, but does not need to be kept */
typedef struct {
  char  *connection_address;
  char  *connection_type;
  char  *media_type;
  char  *media_port[SDP_MAX_RTP_CHANNELS];
  char  *media_proto[SDP_MAX_RTP_CHANNELS];
  guint8 media_count;

  /* MSRP transport info (as set while parsing path attribute) */
  gboolean msrp_transport_address_set;
  guint32  msrp_ipaddr[4];
  guint16  msrp_port_number;

} disposable_media_info_t;

/* key-mgmt dissector
 * IANA registry:
 * http://www.iana.org/assignments/sdp-parameters
 */
static dissector_table_t key_mgmt_dissector_table;

/* Subdissector functions */
static void
dissect_sdp_owner(tvbuff_t *tvb, proto_item *ti) {
  proto_tree *sdp_owner_tree;
  gint        offset, next_offset, tokenlen;

  offset = 0;

  sdp_owner_tree = proto_item_add_subtree(ti, ett_sdp_owner);

  /* Find the username */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_owner_tree, hf_owner_username, tvb, offset, tokenlen,
                      ENC_ASCII|ENC_NA);
  offset = next_offset  + 1;

  /* Find the session id */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_owner_tree, hf_owner_sessionid, tvb, offset,
                      tokenlen, ENC_ASCII|ENC_NA);
  offset = next_offset + 1;

  /* Find the version */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_owner_tree, hf_owner_version, tvb, offset, tokenlen,
                      ENC_ASCII|ENC_NA);
  offset = next_offset + 1;

  /* Find the network type */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_owner_tree, hf_owner_network_type, tvb, offset,
                      tokenlen, ENC_ASCII|ENC_NA);
  offset = next_offset + 1;

  /* Find the address type */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_owner_tree, hf_owner_address_type, tvb, offset,
                      tokenlen, ENC_ASCII|ENC_NA);
  offset = next_offset + 1;

  /* Find the address */
  proto_tree_add_item(sdp_owner_tree, hf_owner_address, tvb, offset, -1, ENC_ASCII|ENC_NA);
}

/*
 * XXX - this can leak memory if an exception is thrown after we've fetched
 * a string.
 */
static void
dissect_sdp_connection_info(tvbuff_t *tvb, proto_item* ti,
                            disposable_media_info_t *media_info) {
  proto_tree *sdp_connection_info_tree;
  gint        offset, next_offset, tokenlen;

  offset = 0;

  sdp_connection_info_tree = proto_item_add_subtree(ti,
                                                    ett_sdp_connection_info);

  /* Find the network type */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_connection_info_tree,
                      hf_connection_info_network_type, tvb, offset, tokenlen,
                      ENC_ASCII|ENC_NA);
  offset = next_offset + 1;

  /* Find the address type */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;
  /* Save connection address type */
  media_info->connection_type = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);


  proto_tree_add_item(sdp_connection_info_tree,
                      hf_connection_info_address_type, tvb, offset, tokenlen,
                      ENC_ASCII|ENC_NA);
  offset = next_offset + 1;

  /* Find the connection address */
  /* XXX - what if there's a <number of addresses> value? */
  next_offset = tvb_find_guint8(tvb, offset, -1, '/');
  if (next_offset == -1) {
    tokenlen = -1; /* end of tvbuff */
    /* Save connection address */
    media_info->connection_address =
      (char*)tvb_get_ephemeral_string(tvb, offset, tvb_length_remaining(tvb, offset));
  } else {
    tokenlen = next_offset - offset;
    /* Save connection address */
    media_info->connection_address = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);
  }

  proto_tree_add_item(sdp_connection_info_tree,
                      hf_connection_info_connection_address, tvb, offset,
                      tokenlen, ENC_ASCII|ENC_NA);
  if (next_offset != -1) {
    offset = next_offset + 1;
    next_offset = tvb_find_guint8(tvb, offset, -1, '/');
    if (next_offset == -1) {
      tokenlen = -1; /* end of tvbuff */
    } else {
      tokenlen = next_offset - offset;
    }
    proto_tree_add_item(sdp_connection_info_tree,
                        hf_connection_info_ttl, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
    if (next_offset != -1) {
      offset = next_offset + 1;
      proto_tree_add_item(sdp_connection_info_tree,
                          hf_connection_info_num_addr, tvb, offset, -1, ENC_ASCII|ENC_NA);
    }
  }
}

static void
dissect_sdp_bandwidth(tvbuff_t *tvb, proto_item *ti) {
  proto_tree *sdp_bandwidth_tree;
  gint        offset, next_offset, tokenlen;
  proto_item *item;
  gboolean    unit_is_kbs = FALSE;
  gboolean    unit_is_bps = FALSE;

  offset = 0;

  sdp_bandwidth_tree = proto_item_add_subtree(ti, ett_sdp_bandwidth);

  /* find the modifier */
  next_offset = tvb_find_guint8(tvb, offset, -1, ':');

  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;

  item = proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_modifier, tvb, offset,
                             tokenlen, ENC_ASCII|ENC_NA);
  if (tvb_strneql(tvb, offset, "CT", 2) == 0) {
    proto_item_append_text(item, " [Conference Total(total bandwidth of all RTP sessions)]");
    unit_is_kbs = TRUE;
  } else if (tvb_strneql(tvb, offset, "AS", 2) == 0) {
    proto_item_append_text(item, " [Application Specific (RTP session bandwidth)]");
    unit_is_kbs = TRUE;
  } else if (tvb_strneql(tvb, offset, "TIAS", 4) == 0) {
    proto_item_append_text(item, " [Transport Independent Application Specific maximum]");
    unit_is_bps = TRUE;
  }


  offset = next_offset + 1;

  item = proto_tree_add_item(sdp_bandwidth_tree, hf_bandwidth_value, tvb, offset, -1,
                             ENC_ASCII|ENC_NA);
  if (unit_is_kbs == TRUE)
    proto_item_append_text(item, " kb/s");
  if (unit_is_bps == TRUE)
    proto_item_append_text(item, " b/s");
}

static void dissect_sdp_time(tvbuff_t *tvb, proto_item* ti) {
  proto_tree *sdp_time_tree;
  gint        offset, next_offset, tokenlen;

  offset = 0;

  sdp_time_tree = proto_item_add_subtree(ti, ett_sdp_time);

  /* get start time */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;
  proto_tree_add_item(sdp_time_tree, hf_time_start, tvb, offset, tokenlen,
                      ENC_ASCII|ENC_NA);

  /* get stop time */
  offset = next_offset + 1;
  proto_tree_add_item(sdp_time_tree, hf_time_stop, tvb, offset, -1, ENC_ASCII|ENC_NA);
}

static void dissect_sdp_repeat_time(tvbuff_t *tvb, proto_item* ti) {
  proto_tree *sdp_repeat_time_tree;
  gint        offset, next_offset, tokenlen;

  offset = 0;

  sdp_repeat_time_tree = proto_item_add_subtree(ti, ett_sdp_time);

  /* get interval */
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;
  proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_interval, tvb,
                      offset, tokenlen, ENC_ASCII|ENC_NA);

  /* get duration */
  offset = next_offset + 1;
  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;
  proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_duration, tvb,
                      offset, tokenlen, ENC_ASCII|ENC_NA);

  /* get offsets */
  do{
    offset = next_offset +1;
    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
    if (next_offset != -1) {
      tokenlen = next_offset - offset;
    } else {
      tokenlen = -1; /* end of tvbuff */
    }
    proto_tree_add_item(sdp_repeat_time_tree, hf_repeat_time_offset,
                        tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
  } while (next_offset != -1);

}
static void
dissect_sdp_timezone(tvbuff_t *tvb, proto_item* ti) {
  proto_tree* sdp_timezone_tree;
  gint        offset, next_offset, tokenlen;

  offset = 0;

  sdp_timezone_tree = proto_item_add_subtree(ti, ett_sdp_timezone);

  do{
    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
    if (next_offset == -1)
      break;
    tokenlen = next_offset - offset;

    proto_tree_add_item(sdp_timezone_tree, hf_timezone_time, tvb, offset,
                        tokenlen, ENC_ASCII|ENC_NA);
    offset = next_offset + 1;
    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
    if (next_offset != -1) {
      tokenlen = next_offset - offset;
    } else {
      tokenlen = -1; /* end of tvbuff */
    }
    proto_tree_add_item(sdp_timezone_tree, hf_timezone_offset, tvb, offset,
                        tokenlen, ENC_ASCII|ENC_NA);
    offset = next_offset + 1;
  } while (next_offset != -1);

}


static void dissect_sdp_encryption_key(tvbuff_t *tvb, proto_item * ti) {
  proto_tree *sdp_encryption_key_tree;
  gint        offset, next_offset, tokenlen;

  offset = 0;

  sdp_encryption_key_tree = proto_item_add_subtree(ti, ett_sdp_encryption_key);

  next_offset = tvb_find_guint8(tvb, offset, -1, ':');

  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_encryption_key_tree, hf_encryption_key_type,
                      tvb, offset, tokenlen, ENC_ASCII|ENC_NA);

  offset = next_offset + 1;
  proto_tree_add_item(sdp_encryption_key_tree, hf_encryption_key_data,
                      tvb, offset, -1, ENC_ASCII|ENC_NA);
}

static void dissect_key_mgmt(tvbuff_t *tvb, packet_info * pinfo, proto_item * ti) {
  gchar      *data_p      = NULL;
  gchar      *prtcl_id    = NULL;
  gint        len;
  tvbuff_t   *keymgmt_tvb;
  gboolean    found_match = FALSE;
  proto_tree *key_tree;
  gint        next_offset;
  gint        offset      = 0;
  gint        tokenlen;

  key_tree = proto_item_add_subtree(ti, ett_sdp_key_mgmt);

  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;
  prtcl_id = tvb_get_ephemeral_string(tvb, offset, tokenlen);

  proto_tree_add_item(key_tree, hf_key_mgmt_prtcl_id, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);

  offset = next_offset + 1;

  len = tvb_length_remaining(tvb, offset);
  if (len < 0)
    return;

  data_p = tvb_get_ephemeral_string(tvb, offset, len);
  keymgmt_tvb = base64_to_tvb(tvb, data_p);
  add_new_data_source(pinfo, keymgmt_tvb, "Key Management Data");

  if ((prtcl_id != NULL) && (key_mgmt_dissector_table != NULL)) {
    found_match = dissector_try_string(key_mgmt_dissector_table,
                                       prtcl_id,
                                       keymgmt_tvb, pinfo,
                                       key_tree);
  }

  if (found_match) {
    proto_item *ti2 = proto_tree_add_item(key_tree, hf_key_mgmt_data,
                                          keymgmt_tvb, 0, -1, ENC_NA);
    PROTO_ITEM_SET_HIDDEN(ti2);
  } else {
    proto_tree_add_item(key_tree, hf_key_mgmt_data,
                        keymgmt_tvb, 0, -1, ENC_NA);
  }

}


static void dissect_sdp_session_attribute(tvbuff_t *tvb, packet_info * pinfo, proto_item * ti) {
  proto_tree *sdp_session_attribute_tree;
  gint        offset, next_offset, tokenlen;
  guint8     *field_name;

  offset = 0;

  sdp_session_attribute_tree = proto_item_add_subtree(ti,
                                                      ett_sdp_session_attribute);

  next_offset = tvb_find_guint8(tvb, offset, -1, ':');

  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;

  proto_tree_add_item(sdp_session_attribute_tree, hf_session_attribute_field,
                      tvb, offset, tokenlen, ENC_ASCII|ENC_NA);

  field_name = tvb_get_ephemeral_string(tvb, offset, tokenlen);

  offset = next_offset + 1;

  if (strcmp((char*)field_name, "ipbcp") == 0) {
    offset = tvb_pbrk_guint8(tvb, offset, -1,"0123456789", NULL);

    if (offset == -1)
      return;

    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

    if (next_offset == -1)
      return;

    tokenlen = next_offset - offset;

    proto_tree_add_item(sdp_session_attribute_tree, hf_ipbcp_version, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);

    offset = tvb_pbrk_guint8(tvb, offset, -1,"ABCDEFGHIJKLMNOPQRSTUVWXYZ", NULL);

    if (offset == -1)
      return;

    tokenlen = tvb_find_line_end(tvb, offset, -1, &next_offset, FALSE);

    if (tokenlen == -1)
      return;

    proto_tree_add_item(sdp_session_attribute_tree, hf_ipbcp_type, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
  } else if (strcmp((char*)field_name, "key-mgmt") == 0) {
    tvbuff_t   *key_tvb;
    proto_item *key_ti;

    key_tvb = tvb_new_subset_remaining(tvb, offset);
    key_ti = proto_tree_add_item(sdp_session_attribute_tree, hf_key_mgmt_att_value, key_tvb, 0, -1, ENC_ASCII|ENC_NA);

    dissect_key_mgmt(key_tvb, pinfo, key_ti);
  } else {
    proto_tree_add_item(sdp_session_attribute_tree, hf_session_attribute_value,
                        tvb, offset, -1, ENC_ASCII|ENC_NA);
  }
}


/* Dissect media description */
static void
dissect_sdp_media(tvbuff_t *tvb, proto_item *ti,
                  transport_info_t *transport_info, disposable_media_info_t *media_info) {
  proto_tree *sdp_media_tree;
  gint        offset, next_offset, tokenlen, idx;
  guint8     *media_format;

  offset = 0;

  /* Create tree for media session */
  sdp_media_tree = proto_item_add_subtree(ti, ett_sdp_media);

  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

  if (next_offset == -1)
    return;

  tokenlen = next_offset - offset;

  /* Type of media session */
  proto_tree_add_item(sdp_media_tree, hf_media_media, tvb, offset, tokenlen,
                      ENC_ASCII|ENC_NA);

  media_info->media_type = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);

  offset = next_offset + 1;

  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
  if (next_offset == -1)
    return;
  tokenlen = next_offset - offset;
  next_offset = tvb_find_guint8(tvb, offset, tokenlen, '/');

  if (next_offset != -1) {
    tokenlen = next_offset - offset;
    /* Save port info */
    media_info->media_port[media_info->media_count] = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);

    proto_tree_add_uint(sdp_media_tree, hf_media_port, tvb, offset, tokenlen,
                        atoi((char*)tvb_get_ephemeral_string(tvb, offset, tokenlen)));
    offset = next_offset + 1;
    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
    if (next_offset == -1)
      return;
    tokenlen = next_offset - offset;
    proto_tree_add_item(sdp_media_tree, hf_media_portcount, tvb, offset,
                        tokenlen, ENC_ASCII|ENC_NA);
    offset = next_offset + 1;
  } else {
    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

    if (next_offset == -1)
      return;
    tokenlen = next_offset - offset;
    /* Save port info */
    media_info->media_port[media_info->media_count] = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);
    /* XXX Remember Port */
    proto_tree_add_uint(sdp_media_tree, hf_media_port, tvb, offset, tokenlen,
                        atoi((char*)tvb_get_ephemeral_string(tvb, offset, tokenlen)));
    offset = next_offset + 1;
  }

  next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

  if ( next_offset == -1)
    return;

  tokenlen = next_offset - offset;
  /* Save port protocol */
  media_info->media_proto[media_info->media_count] = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);

  /* XXX Remember Protocol */
  proto_tree_add_item(sdp_media_tree, hf_media_proto, tvb, offset, tokenlen,
                      ENC_ASCII|ENC_NA);

  do {
    offset = next_offset + 1;
    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

    if (next_offset == -1) {
      tokenlen = tvb_length_remaining(tvb, offset); /* End of tvbuff */
      if (tokenlen == 0)
        break; /* Nothing more left */
    } else {
      tokenlen = next_offset - offset;
    }

    if (!strcmp(media_info->media_proto[media_info->media_count], "RTP/AVP")) {
      media_format = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      proto_tree_add_string(sdp_media_tree, hf_media_format, tvb, offset,
                            tokenlen, val_to_str_ext((guint32)strtoul((char*)media_format, NULL, 10), &rtp_payload_type_vals_ext, "%u"));
      idx = transport_info->media[transport_info->media_count].pt_count;
      transport_info->media[transport_info->media_count].pt[idx] = (gint32)strtol((char*)media_format, NULL, 10);
      if (idx < (SDP_MAX_RTP_PAYLOAD_TYPES-1))
        transport_info->media[transport_info->media_count].pt_count++;
    } else {
      proto_tree_add_item(sdp_media_tree, hf_media_format, tvb, offset,
                          tokenlen, ENC_ASCII|ENC_NA);
    }
  } while (next_offset != -1);

  /* XXX Dissect traffic to "Port" as "Protocol"
   *     Remember this Port/Protocol pair so we can tear it down again later
   *     Actually, it's harder than that:
   *         We need to find out the address of the other side first and it
   *         looks like that info can be found in SIP headers only.
   */

}

static tvbuff_t *
ascii_bytes_to_tvb(tvbuff_t *tvb, packet_info *pinfo, gint len, gchar *msg)
{
  guint8 *buf = (guint8 *)wmem_alloc(pinfo->pool, 10240);

  /* arbitrary maximum length */
  if (len < 20480) {
    int i;
    tvbuff_t *bytes_tvb;

    /* first, skip to where the encoded pdu starts, this is
       the first hex digit after the '=' char.
    */
    while (1) {
      if ((*msg == 0) || (*msg == '\n')) {
        return NULL;
      }
      if (*msg == '=') {
        msg++;
        break;
      }
      msg++;
    }
    while (1) {
      if ((*msg == 0) || (*msg == '\n')) {
        return NULL;
      }
      if ( ((*msg >= '0') && (*msg <= '9'))
           || ((*msg >= 'a') && (*msg <= 'f'))
           || ((*msg >= 'A') && (*msg <= 'F'))) {
        break;
      }
      msg++;
    }
    i = 0;
    while (((*msg >= '0') && (*msg <= '9'))
           || ((*msg >= 'a') && (*msg <= 'f'))
           || ((*msg >= 'A') && (*msg <= 'F'))) {
      int val;
      if ((*msg >= '0') && (*msg <= '9')) {
        val = (*msg)-'0';
      } else if ((*msg >= 'a') && (*msg <= 'f')) {
        val = (*msg)-'a'+10;
      } else if ((*msg >= 'A') && (*msg <= 'F')) {
        val = (*msg)-'A'+10;
      } else {
        return NULL;
      }
      val <<= 4;
      msg++;
      if ((*msg >= '0') && (*msg <= '9')) {
        val |= (*msg)-'0';
      } else if ((*msg >= 'a') && (*msg <= 'f')) {
        val |= (*msg)-'a'+10;
      } else if ((*msg >= 'A') && (*msg <= 'F')) {
        val |= (*msg)-'A'+10;
      } else {
        return NULL;
      }
      msg++;

      buf[i] = (guint8)val;
      i++;
    }
    if (i == 0) {
      return NULL;
    }
    bytes_tvb = tvb_new_child_real_data(tvb, buf, i, i);
    add_new_data_source(pinfo, bytes_tvb, "ASCII bytes to tvb");
    return bytes_tvb;
  }
  return NULL;
}

/* Annex X Profiles and levels definition */
static const value_string h263_profile_vals[] =
{
  { 0,    "Baseline Profile" },
  { 1,    "H.320 Coding Efficiency Version 2 Backward-Compatibility Profile" },
  { 2,    "Version 1 Backward-Compatibility Profile" },
  { 3,    "Version 2 Interactive and Streaming Wireless Profile" },
  { 4,    "Version 3 Interactive and Streaming Wireless Profile" },
  { 5,    "Conversational High Compression Profile" },
  { 6,    "Conversational Internet Profile" },
  { 7,    "Conversational Interlace Profile" },
  { 8,    "High Latency Profile" },
  { 0, NULL },
};


/* RFC 4629 The level are described in table X.2 of H.263 annex X */
static const value_string h263_level_vals[] =
{
  { 10,    "QCIF (176 x 144), 1 x 64Kb/s" },
  { 20,    "CIF (352 x 288), 2 x 64Kb/s" },
  { 30,    "CIF (352 x 288), 6 x 64Kb/s" },
  { 40,    "CIF (352 x 288), 32 x 64Kb/s" },
  { 45,    "QCIF (176 x144) support of CPFMT, 2 x 64Kb/s" },
  { 50,    "CIF (352 x 288) support of CPFMT, 64 x 64Kb/s" },
  { 60,    "CPFMT: 720 x 288 support of CPFMT, 128 x 64Kb/s" },
  { 70,    "CPFMT: 720 x 576 support of CPFMT, 256 x 64Kb/s" },
  { 0, NULL },
};


static const value_string h264_packetization_mode_vals[] =
{
  { 0,    "Single NAL mode" },
  { 1,    "Non-interleaved mode" },
  { 2,    "Interleaved mode" },
  { 0, NULL },
};

/*
 * TODO: Make this a more generic routine to dissect fmtp parameters depending on media types
 */
static void
decode_sdp_fmtp(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, gint offset, gint tokenlen, char *mime_type) {
  gint                 next_offset;
  gint                 end_offset;
  guint8              *field_name;
  gchar               *format_specific_parameter;
  proto_item          *item;
  tvbuff_t * volatile  data_tvb;

  end_offset = offset + tokenlen;

#if 0
    proto_tree_add_text(tree, tvb, offset, tokenlen, "Debug; Analysed string: '%s'",
    tvb_get_ephemeral_string(tvb, offset, tokenlen));
#endif

  /* Look for an '=' within this value - this may indicate that there is a
     profile-level-id parameter to find if the MPEG4 media type is in use */
  next_offset = tvb_find_guint8(tvb, offset, -1, '=');
  if (next_offset == -1)
  {
    /* Give up (and avoid exception) if '=' not found */
    return;
  }

  /* Find the name of the parameter */
  tokenlen = next_offset - offset;
  field_name = tvb_get_ephemeral_string(tvb, offset, tokenlen);
#if 0
  proto_tree_add_text(tree, tvb, offset, tokenlen, "Debug; MIMEtype '%s'Parameter name: '%s'", mime_type, field_name); */
#endif
  offset = next_offset;

  /* Dissect the MPEG4 profile-level-id parameter if present */
  if ((mime_type != NULL) && (g_ascii_strcasecmp(mime_type, "MP4V-ES") == 0)) {
    if (strcmp((char*)field_name, "profile-level-id") == 0) {
      offset++;
      tokenlen = end_offset - offset;
      format_specific_parameter = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      item = proto_tree_add_uint(tree, hf_sdp_fmtp_mpeg4_profile_level_id, tvb, offset, tokenlen,
                                 (guint32)strtol((char*)format_specific_parameter, NULL, 10));
      PROTO_ITEM_SET_GENERATED(item);
    } else if (strcmp((char*)field_name, "config") == 0) {
      /* String including "=" */
      tokenlen = end_offset - offset;
      format_specific_parameter = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      /* ascii_bytes_to_tvb requires the "=" to be in the buffer */
      data_tvb = ascii_bytes_to_tvb(tvb, pinfo, tokenlen, format_specific_parameter);
      if (mp4ves_handle && data_tvb) {
        dissect_mp4ves_config(data_tvb, pinfo, tree);
      }
    }
  }

  /* Dissect the H263-2000 profile parameter if present */
  if (((mime_type != NULL) && (g_ascii_strcasecmp(mime_type, "H263-2000") == 0)) ||
      ((mime_type != NULL) && (g_ascii_strcasecmp(mime_type, "H263-1998") == 0))) {
    if (strcmp((char*)field_name, "profile") == 0) {
      offset++;
      tokenlen = end_offset - offset;
      format_specific_parameter = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      item = proto_tree_add_uint(tree, hf_sdp_fmtp_h263_profile, tvb, offset, tokenlen,
                                 (guint32)strtol((char*)format_specific_parameter, NULL, 10));
      PROTO_ITEM_SET_GENERATED(item);
    } else if (strcmp((char*)field_name, "level") == 0) {
      offset++;
      tokenlen = end_offset - offset;
      format_specific_parameter = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      item = proto_tree_add_uint(tree, hf_sdp_fmtp_h263_level, tvb, offset, tokenlen,
                                 (guint32)strtol((char*)format_specific_parameter, NULL, 10));
      PROTO_ITEM_SET_GENERATED(item);
    }
  }


  /* Dissect the H264 profile-level-id parameter
   * RFC 3984:
   * A base16 [6] (hexadecimal) representation of
   * the following three bytes in the sequence
   * parameter set NAL unit specified in [1]: 1)
   * profile_idc, 2) a byte herein referred to as
   * profile-iop, composed of the values of
   * constraint_set0_flag, constraint_set1_flag,
   * constraint_set2_flag, and reserved_zero_5bits
   * in bit-significance order, starting from the
   * most significant bit, and 3) level_idc.
   */
  if ((mime_type != NULL) && (g_ascii_strcasecmp(mime_type, "H264") == 0)) {
    if (strcmp(field_name, "profile-level-id") == 0) {
      int length = 0;

      /* Length includes "=" as it's required by ascii_bytes_to_tvb()*/
      tokenlen = end_offset - offset;
      format_specific_parameter = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      data_tvb = ascii_bytes_to_tvb(tvb, pinfo, tokenlen, format_specific_parameter);
      if (!data_tvb) {
        proto_tree_add_text(tree, tvb, offset, tokenlen, "Could not convert '%s' to 3 bytes", format_specific_parameter);
        return;
      }
      length = tvb_length(data_tvb);
      if (length == 3) {
        if (h264_handle && data_tvb) {
          dissect_h264_profile(data_tvb, pinfo, tree);
        }
      } else {
        item = proto_tree_add_text(tree, tvb, offset, tokenlen, "Incorrectly coded, must be three bytes");
        PROTO_ITEM_SET_GENERATED(item);
      }
    } else if (strcmp(field_name, "packetization-mode") == 0) {
      offset++;
      tokenlen = end_offset - offset;
      format_specific_parameter = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      item = proto_tree_add_uint(tree, hf_sdp_h264_packetization_mode, tvb, offset, tokenlen,
                                 (guint32)strtol((char*)format_specific_parameter, NULL, 10));
      PROTO_ITEM_SET_GENERATED(item);
    } else if (strcmp(field_name, "sprop-parameter-sets") == 0) {
      /* The value of the parameter is the
         base64 [6] representation of the initial
         parameter set NAL units as specified in
         sections 7.3.2.1 and 7.3.2.2 of [1].  The
         parameter sets are conveyed in decoding order,
         and no framing of the parameter set NAL units
         takes place.  A comma is used to separate any
         pair of parameter sets in the list.
      */
      gchar *data_p = NULL;
      gint   comma_offset;


      /* Move past '=' */
      offset++;
      comma_offset = tvb_find_guint8(tvb, offset, -1, ',');
      if (comma_offset != -1) {
        tokenlen = comma_offset - offset;
      } else {
        tokenlen = end_offset - offset;
      }

      data_p = tvb_get_ephemeral_string(tvb, offset, tokenlen);
      proto_tree_add_text(tree, tvb, offset, tokenlen, "NAL unit 1 string: %s", data_p);

      /* proto_tree_add_text(tree, tvb, offset, tokenlen, "String %s", data_p); */
      data_tvb = base64_to_tvb(tvb, data_p);
      add_new_data_source(pinfo, data_tvb, "h264 prop-parameter-sets");

      if (h264_handle && data_tvb) {
        TRY {
          dissect_h264_nal_unit(data_tvb, pinfo, tree);
        }
        CATCH_NONFATAL_ERRORS {
          show_exception(tvb, pinfo, tree, EXCEPT_CODE, GET_MESSAGE);
        }
        ENDTRY;
        if (comma_offset != -1) {
          /* Second NAL unit */
          offset   = comma_offset +1;
          tokenlen = end_offset - offset;
          data_p   = tvb_get_ephemeral_string(tvb, offset, tokenlen);
          proto_tree_add_text(tree, tvb, offset, tokenlen, "NAL unit 2 string: %s", data_p);
          data_tvb = base64_to_tvb(tvb, data_p);
          add_new_data_source(pinfo, data_tvb, "h264 prop-parameter-sets 2");
          dissect_h264_nal_unit(data_tvb, pinfo, tree);
        }
      }
    }
  }

}

typedef struct {
  const char *name;
} sdp_names_t;

#define SDP_RTPMAP              1
#define SDP_FMTP                2
#define SDP_PATH                3
#define SDP_H248_ITEM           4
#define SDP_CRYPTO              5
#define SDP_SPRTMAP             6

static const sdp_names_t sdp_media_attribute_names[] = {
  { "Unknown-name"},    /* 0 Pad so that the real headers start at index 1 */
  { "rtpmap"},          /* 1 */
  { "fmtp"},            /* 2 */
  { "path"},            /* 3 */
  { "h248item"},        /* 4 */
  { "crypto"},          /* 5 */
  { "sprt"},            /* 6 */
};

static gint find_sdp_media_attribute_names(tvbuff_t *tvb, int offset, guint len)
{
  guint i;

  for (i = 1; i < array_length(sdp_media_attribute_names); i++) {
    if ((len == strlen(sdp_media_attribute_names[i].name)) &&
        (tvb_strncaseeql(tvb, offset, sdp_media_attribute_names[i].name, len) == 0))
      return i;
  }

  return -1;
}

static void dissect_sdp_media_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_item * ti, int length,
                                        transport_info_t *transport_info, disposable_media_info_t *media_info) {
  proto_tree *sdp_media_attribute_tree, *parameter_item;
  proto_item *fmtp_item, *media_format_item, *parameter_tree;
  proto_tree *fmtp_tree;
  gint        offset, next_offset, tokenlen, n, colon_offset;
  /*??guint8 *field_name;*/
  guint8     *payload_type;
  guint8     *attribute_value;
  gint       *key;
  guint8      pt;
  gint        sdp_media_attrbute_code;
  const char *msrp_res           = "msrp://";
  const char *h324ext_h223lcparm = "h324ext/h223lcparm";
  gboolean    has_more_pars      = TRUE;
  tvbuff_t   *h245_tvb;
  guint8      master_key_length  = 0, master_salt_length = 0;
  encoding_name_and_rate_t *encoding_name_and_rate;

  offset = 0;

  /* Create attribute tree */
  sdp_media_attribute_tree = proto_item_add_subtree(ti,
                                                    ett_sdp_media_attribute);
  /* Find end of field */
  colon_offset = tvb_find_guint8(tvb, offset, -1, ':');

  if (colon_offset == -1)
    return;

  /* Attribute field name is token before ':' */
  tokenlen = colon_offset - offset;
  proto_tree_add_item(sdp_media_attribute_tree,
                      hf_media_attribute_field,
                      tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
  /*??field_name = tvb_get_ephemeral_string(tvb, offset, tokenlen);*/
  sdp_media_attrbute_code = find_sdp_media_attribute_names(tvb, offset, tokenlen);

  /* Skip colon */
  offset = colon_offset + 1;
  /* skip leading wsp */
  offset = tvb_skip_wsp(tvb, offset, tvb_length_remaining(tvb, offset));

  /* Value is the remainder of the line */
  attribute_value = tvb_get_ephemeral_string(tvb, offset, tvb_length_remaining(tvb, offset));



  /*********************************************/
  /* Special parsing for some field name types */

  switch (sdp_media_attrbute_code) {
  case SDP_RTPMAP:
    /* decode the rtpmap to see if it is DynamicPayload to dissect them automatic */
    next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

    if (next_offset == -1)
      return;

    tokenlen = next_offset - offset;

    proto_tree_add_item(sdp_media_attribute_tree, hf_media_format, tvb,
                        offset, tokenlen, ENC_ASCII|ENC_NA);

    payload_type = tvb_get_ephemeral_string(tvb, offset, tokenlen);

    offset = next_offset + 1;

    next_offset = tvb_find_guint8(tvb, offset, -1, '/');

    if (next_offset == -1) {
      return;
    }

    tokenlen = next_offset - offset;

    proto_tree_add_item(sdp_media_attribute_tree, hf_media_encoding_name, tvb,
                        offset, tokenlen, ENC_ASCII|ENC_NA);

    pt = atoi((char*)payload_type);
    if (pt >= SDP_NO_OF_PT) {
      return;   /* Invalid */
    }

    key  = se_new(gint);
    *key = (gint)strtol((char*)payload_type, NULL, 10);

    transport_info->encoding_name[pt] = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);

    next_offset =  next_offset + 1;
    offset = next_offset;
    while (length-1 >= next_offset) {
      if (!g_ascii_isdigit(tvb_get_guint8(tvb, next_offset)))
        break;
      next_offset++;
    }
    tokenlen = next_offset - offset;
    proto_tree_add_item(sdp_media_attribute_tree, hf_media_sample_rate, tvb,
                        offset, tokenlen, ENC_ASCII|ENC_NA);
    transport_info->sample_rate[pt] = atoi(tvb_get_ephemeral_string(tvb, offset, tokenlen));
    /* As per RFC2327 it is possible to have multiple Media Descriptions ("m=").
       For example:

       a=rtpmap:101 G726-32/8000
       m=audio 49170 RTP/AVP 0 97
       a=rtpmap:97 telephone-event/8000
       m=audio 49172 RTP/AVP 97 101
       a=rtpmap:97 G726-24/8000

       The Media attributes ("a="s) after the "m=" only apply for that "m=".
       If there is an "a=" before the first "m=", that attribute applies for
       all the session (all the "m="s).
    */

    /* so, if this "a=" appear before any "m=", we add it to all the dynamic
     * hash tables
     */
    if (transport_info->media_count < 0) {
      for (n = 0; n < SDP_MAX_RTP_CHANNELS; n++) {
        encoding_name_and_rate = se_new(encoding_name_and_rate_t);
        encoding_name_and_rate->encoding_name = se_strdup(transport_info->encoding_name[pt]);
        encoding_name_and_rate->sample_rate = transport_info->sample_rate[pt];
        if (n == 0) {
          g_hash_table_insert(transport_info->media[n].rtp_dyn_payload,
                              key, encoding_name_and_rate);
        } else {    /* we create a new key and encoding_name to assign to the other hash tables */
          gint *key2;
          key2  = se_new(gint);
          *key2 = (gint)strtol((char*)payload_type, NULL, 10);
          g_hash_table_insert(transport_info->media[n].rtp_dyn_payload,
                              key2, encoding_name_and_rate);
        }
      }
      return;
      /* if the "a=" is after an "m=", only apply to this "m=" */
    } else
      /* in case there is an overflow in SDP_MAX_RTP_CHANNELS, we keep always the last "m=" */
      encoding_name_and_rate = se_new(encoding_name_and_rate_t);

    encoding_name_and_rate->encoding_name = se_strdup(transport_info->encoding_name[pt]);
    encoding_name_and_rate->sample_rate   = transport_info->sample_rate[pt];
    g_hash_table_insert(transport_info->media[ transport_info->media_count ].rtp_dyn_payload,
                          key, encoding_name_and_rate);
    break;
  case SDP_FMTP:
    if (sdp_media_attribute_tree) {
      guint8 media_format;
      /* Reading the Format parameter(fmtp) */
      /* Skip leading space, if any */
      offset = tvb_skip_wsp(tvb, offset, tvb_length_remaining(tvb, offset));
      /* Media format extends to the next space */
      next_offset = tvb_find_guint8(tvb, offset, -1, ' ');

      if (next_offset == -1)
        return;

      tokenlen = next_offset - offset;


      media_format_item = proto_tree_add_item(sdp_media_attribute_tree,
                                              hf_media_format, tvb, offset,
                                              tokenlen, ENC_ASCII|ENC_NA);
      media_format = atoi((char*)tvb_get_ephemeral_string(tvb, offset, tokenlen));
      if (media_format >= SDP_NO_OF_PT) {
        return;   /* Invalid */
      }

      /* Append encoding name to format if known */
      proto_item_append_text(media_format_item, " [%s]",
                             transport_info->encoding_name[media_format]);

#if 0 /* XXX:  ?? */
      payload_type = tvb_get_ephemeral_string(tvb, offset, tokenlen);
#endif
      /* Move offset past the payload type */
      offset = next_offset + 1;

      while (has_more_pars == TRUE) {
        next_offset = tvb_find_guint8(tvb, offset, -1, ';');
        offset = tvb_skip_wsp(tvb, offset, tvb_length_remaining(tvb, offset));

        if (next_offset == -1) {
          has_more_pars = FALSE;
          next_offset= tvb_length(tvb);
        }

        /* There are at least 2 - add the first parameter */
        tokenlen = next_offset - offset;
        fmtp_item = proto_tree_add_item(sdp_media_attribute_tree,
                                        hf_media_format_specific_parameter, tvb,
                                        offset, tokenlen, ENC_ASCII|ENC_NA);

        fmtp_tree = proto_item_add_subtree(fmtp_item, ett_sdp_fmtp);

        decode_sdp_fmtp(fmtp_tree, tvb, pinfo, offset, tokenlen,
                        transport_info->encoding_name[media_format]);

        /* Move offset past "; " and onto firts char */
        offset = next_offset + 1;
      }
    }
    break;
  case SDP_PATH:
    /* msrp attributes that contain address needed for conversation */
    /*    RFC 4975
     *    path = path-label ":" path-list
     *    path-label = "path"
     *    path-list= MSRP-URI *(SP MSRP-URI)
     *    MSRP-URI = msrp-scheme "://" authority
     *       ["/" session-id] ";" transport *( ";" URI-parameter)
     *                        ; authority as defined in RFC3986
     *
     *    msrp-scheme = "msrp" / "msrps"
     * RFC 3986
     * The authority component is preceded by a double slash ("//") and is terminated by
     * the next slash ("/"), question mark ("?"), or number sign ("#") character, or by
     * the end of the URI.
     */

    /* Check for "msrp://" */
    if (strncmp((char*)attribute_value, msrp_res, strlen(msrp_res)) == 0) {
      int address_offset, port_offset, port_end_offset;

      /* Address starts here */
      address_offset = offset + (int)strlen(msrp_res);

      /* Port is after next ':' */
      port_offset = tvb_find_guint8(tvb, address_offset, -1, ':');
      /* Check if port is present if not skipp */
      if (port_offset!= -1) {
        /* Port ends with '/' */
        port_end_offset = tvb_find_guint8(tvb, port_offset, -1, '/');
        if (port_end_offset == -1) {
            /* No "/" look for the ";" */
            port_end_offset = tvb_find_guint8(tvb, port_offset, -1, ';');;
        }
        /* Attempt to convert address */
        if (inet_pton(AF_INET,
                      (char*)tvb_get_ephemeral_string(tvb, address_offset, port_offset-address_offset),
                      &media_info->msrp_ipaddr) > 0) {
          /* Get port number */
          media_info->msrp_port_number = atoi((char*)tvb_get_ephemeral_string(tvb, port_offset + 1, port_end_offset - port_offset - 1));
          /* Set flag so this info can be used */
          media_info->msrp_transport_address_set = TRUE;
        }
      }
    }
    break;
  case SDP_H248_ITEM:
    /* Decode h248 item ITU-T Rec. H.248.12 (2001)/Amd.1 (11/2002)*/
    if (strncmp((char*)attribute_value, h324ext_h223lcparm, strlen(msrp_res)) == 0) {
      /* A.5.1.3 H.223 Logical channel parameters
       * This property indicates the H.245
       * H223LogicalChannelsParameters structure encoded by applying the PER specified in
       * ITU-T Rec. X.691. Value encoded as per A.5.1.2. For text encoding the mechanism defined
       * in ITU-T Rec. H.248.15 is used.
       */
      gint len;
      asn1_ctx_t actx;

      len = (gint)strlen(attribute_value);
      h245_tvb = ascii_bytes_to_tvb(tvb, pinfo, len, attribute_value);
      /* arbitrary maximum length */
      /* should go through a handle, however,  the two h245 entry
         points are different, one is over tpkt and the other is raw
      */
      if (h245_tvb) {
        asn1_ctx_init(&actx, ASN1_ENC_PER, TRUE, pinfo);
        dissect_h245_H223LogicalChannelParameters(h245_tvb, 0, &actx,
                                                  sdp_media_attribute_tree,
                                                  hf_SDPh223LogicalChannelParameters);
      }
    }
    break;
  case SDP_CRYPTO:
      /* http://tools.ietf.org/html/rfc4568
      * 9.1.  Generic "Crypto" Attribute Grammar
      *
      *   The ABNF grammar for the crypto attribute is defined below:
      *
      *   "a=crypto:" tag 1*WSP crypto-suite 1*WSP key-params
      *                                           *(1*WSP session-param)
      *
      *   tag              = 1*9DIGIT
      *   crypto-suite     = 1*(ALPHA / DIGIT / "_")
      *
      *   key-params       = key-param *(";" key-param)
      *   key-param        = key-method ":" key-info
      *   key-method       = "inline" / key-method-ext
      *   key-method-ext   = 1*(ALPHA / DIGIT / "_")
      *   key-info         = 1*(%x21-3A / %x3C-7E) ; visible (printing) chars
      *                                        ; except semi-colon
      *  session-param    = 1*(VCHAR)         ; visible (printing) characters
      *
      *   where WSP, ALPHA, DIGIT, and VCHAR are defined in [RFC4234].
      *
      */

      /* We are at the first colon */
      /* tag */
      next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
      if(next_offset==-1){
          /* XXX Add expert item? */
          return;
      }
      tokenlen    = next_offset - offset;
      proto_tree_add_uint(sdp_media_attribute_tree, hf_sdp_crypto_tag, tvb, offset, tokenlen,
          atoi((char*)tvb_get_ephemeral_string(tvb, offset, tokenlen)));
      offset = next_offset + 1;

      /* crypto-suite */
      next_offset = tvb_find_guint8(tvb, offset, -1, ' ');
      if(next_offset==-1){
          /* XXX Add expert item? */
          return;
      }
      tokenlen    = next_offset - offset;
      parameter_item = proto_tree_add_item(sdp_media_attribute_tree, hf_sdp_crypto_crypto_suite,
          tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
      if (tvb_strncaseeql(tvb, offset, "AES_CM_128_HMAC_SHA1_80", tokenlen) == 0) {

          /* XXX This may only work in simple cases */
          if (transport_info->encryption_algorithm == SRTP_ENC_ALG_NOT_SET) {
              transport_info->encryption_algorithm = SRTP_ENC_ALG_AES_CM;
              transport_info->auth_algorithm       = SRTP_AUTH_ALG_HMAC_SHA1;
              /* number of octets used for the Auth Tag in the RTP payload */
              transport_info->auth_tag_len         = 10;
          }
          master_key_length  = 16; /* 128 bits = 16 octets */
          master_salt_length = 14; /* 112 bits = 14 octets */
      } else if (tvb_strncaseeql(tvb, offset, "AES_CM_128_HMAC_SHA1_32", tokenlen) == 0) {
          /* XXX Thi…