static fragment_head *
force_reassemble_seq(reassembly_table *table, packet_info *pinfo, guint32 id)
{
	fragment_head *fd_head;
	fragment_item *fd_i;
	fragment_item *last_fd;
	guint32 dfpos, size, packet_lost, burst_lost, seq_num;
	guint8 *data;

	fd_head = fragment_get(table, pinfo, id, NULL);

	/* have we already seen this frame ?*/
	if (pinfo->fd->flags.visited) {
		if (fd_head != NULL && fd_head->flags & FD_DEFRAGMENTED) {
			return fd_head;
		} else {
			return NULL;
		}
	}

	if (fd_head==NULL){
		/* we must have it to continue */
		return NULL;
	}

	/* check for packet lost and count the burst of packet lost */
	packet_lost = 0;
	burst_lost = 0;
	seq_num = 0;
	for(fd_i=fd_head->next;fd_i;fd_i=fd_i->next) {
		if (seq_num != fd_i->offset) {
			packet_lost += fd_i->offset - seq_num;
			if ( (fd_i->offset - seq_num) > burst_lost ) {
				burst_lost = fd_i->offset - seq_num;
			}
		}
		seq_num = fd_i->offset + 1;
	}

	/* we have received an entire packet, defragment it and
	 * free all fragments
	 */
	size=0;
	last_fd=NULL;
	for(fd_i=fd_head->next;fd_i;fd_i=fd_i->next) {
	  if(!last_fd || last_fd->offset!=fd_i->offset){
	    size+=fd_i->len;
	  }
	  last_fd=fd_i;
	}

	data = (guint8 *) g_malloc(size);
	fd_head->tvb_data = tvb_new_real_data(data, size, size);
	fd_head->len = size;		/* record size for caller	*/

	/* add all data fragments */
	dfpos = 0;
	last_fd=NULL;
	for (fd_i=fd_head->next;fd_i && fd_i->len + dfpos <= size;fd_i=fd_i->next) {
	  if (fd_i->len) {
	    if(!last_fd || last_fd->offset!=fd_i->offset){
	      memcpy(data+dfpos,tvb_get_ptr(fd_i->tvb_data,0,fd_i->len),fd_i->len);
	      dfpos += fd_i->len;
	    } else {
	      /* duplicate/retransmission/overlap */
	      fd_i->flags    |= FD_OVERLAP;
	      fd_head->flags |= FD_OVERLAP;
	      if( (last_fd->len!=fd_i->datalen)
		  || tvb_memeql(last_fd->tvb_data, 0, tvb_get_ptr(fd_i->tvb_data, 0, last_fd->len), last_fd->len) ){
			fd_i->flags    |= FD_OVERLAPCONFLICT;
			fd_head->flags |= FD_OVERLAPCONFLICT;
	      }
	    }
	  }
	  last_fd=fd_i;
	}

	/* we have defragmented the pdu, now free all fragments*/
	for (fd_i=fd_head->next;fd_i;fd_i=fd_i->next) {
	  if(fd_i->tvb_data){
	    tvb_free(fd_i->tvb_data);
	    fd_i->tvb_data=NULL;
	  }
	}

	/* mark this packet as defragmented */
	fd_head->flags |= FD_DEFRAGMENTED;
	fd_head->reassembled_in=pinfo->fd->num;

	col_append_fstr(pinfo->cinfo, COL_INFO, " (t4-data Reassembled: %d pack lost, %d pack burst lost)", packet_lost, burst_lost);

	p_t38_packet_conv_info->packet_lost = packet_lost;
	p_t38_packet_conv_info->burst_lost = burst_lost;

	return fd_head;
}
Example #2
0
static tvbuff_t *
dissect_pft_fec_detailed(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree,
  guint32 findex,
  guint32 fcount,
  guint16 seq,
  gint offset,
  guint16 plen,
  gboolean fec _U_,
  guint16 rsk,
  guint16 rsz,
  fragment_data *fdx
)
{
  guint16 decoded_size;
  guint32 c_max;
  guint32 rx_min;
  gboolean first, last;
  tvbuff_t *new_tvb=NULL;

  if (fcount > MAX_FRAGMENTS) {
    if (tree)
      proto_tree_add_text(tree, tvb , 0, -1, "[Reassembly of %d fragments not attempted]", fcount);
    return NULL;
  }

  first = findex == 0;
  last = fcount == (findex+1);
  decoded_size = fcount*plen;
  c_max = fcount*plen/(rsk+PFT_RS_P);  /* rounded down */
  rx_min = c_max*rsk/plen;
  if(rx_min*plen<c_max*rsk)
    rx_min++;
  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_data *fd;
    fragment_data *fd_head;

    if(tree)
      proto_tree_add_text (tree, tvb, 0, -1, "want %d, got %d need %d",
                           fcount, fragments, rx_min
        );
    got = ep_alloc(fcount*sizeof(guint32));

    /* make a list of the findex (offset) numbers of the fragments we have */
    fd = fragment_get(pinfo, seq, dcp_fragment_table);
    for (fd_head = fd; fd_head != NULL; fd_head = fd_head->next) {
      if(fd_head->data) {
        got[fragments++] = fd_head->offset; /* this is the findex of the fragment */
      }
    }
    /* put a sentinel at the end */
    got[fragments++] = fcount;
    /* have we got enough for Reed Solomon to try to correct ? */
    if(fragments>=rx_min) { /* yes, in theory */
      guint i,current_findex;
      fragment_data *frag=NULL;
      guint8 *dummy_data = (guint8*) ep_alloc0 (plen);
      tvbuff_t *dummytvb = tvb_new_real_data(dummy_data, plen, plen);
      /* try and decode with missing fragments */
      if(tree)
          proto_tree_add_text (tree, 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) {
          if (tree)
            proto_tree_add_text(tree, tvb , 0, -1, "[Reassembly of %d fragments not attempted]", next_fragment_we_have);
          return NULL;
        }
        for(; current_findex<next_fragment_we_have; current_findex++) {
          frag = fragment_add_seq_check (dummytvb, 0, pinfo, seq,
                                         dcp_fragment_table, dcp_reassembled_table, 
                                         current_findex, plen, (current_findex+1!=fcount));
        }
        current_findex++; /* skip over the fragment we have */
      }
      if(frag)
        new_tvb = process_reassembled_data (tvb, offset, pinfo,
                                            "Reassembled DCP (ETSI)",
                                            frag, &dcp_frag_items,
                                            NULL, tree);
    }
  }
  if(new_tvb) {
    gboolean decoded = TRUE;
    tvbuff_t *dtvb = NULL;
    const guint8 *input = tvb_get_ptr(new_tvb, 0, -1);
    guint16 reassembled_size = tvb_length(new_tvb);
    guint8 *deinterleaved = (guint8*) g_malloc (reassembled_size);
    guint8 *output = (guint8*) g_malloc (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");
    tvb_set_free_cb(dtvb, g_free);

    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");
    tvb_set_free_cb(new_tvb, g_free);
  }
  return new_tvb;
}
Example #3
0
static void
dissect_btobex(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    proto_item    *ti;
    proto_tree    *st;
    fragment_data *frag_msg       = NULL;
    gboolean       save_fragmented, complete;
    tvbuff_t*      new_tvb        = NULL;
    tvbuff_t*      next_tvb       = NULL;
    guint32        no_of_segments = 0;
    int            offset         = 0;

    save_fragmented = pinfo->fragmented;

    complete = FALSE;

    if (fragment_get(pinfo, pinfo->p2p_dir, fragment_table)) {
        /* not the first fragment */
        frag_msg = fragment_add_seq_next(tvb, 0, pinfo, pinfo->p2p_dir,
                                fragment_table, reassembled_table, tvb_length(tvb), TRUE);

        new_tvb = process_reassembled_data(tvb, 0, pinfo,
                        "Reassembled Obex packet", frag_msg, &btobex_frag_items, NULL, tree);

        pinfo->fragmented = TRUE;
    }
    else    {
        if (tvb_length(tvb) < tvb_get_ntohs(tvb, offset+1)) {
            /* first fragment in a sequence */
            no_of_segments = tvb_get_ntohs(tvb, offset+1)/tvb_length(tvb);
            if (tvb_get_ntohs(tvb, offset+1) > (no_of_segments * tvb_length(tvb)))
                no_of_segments++;

            frag_msg = fragment_add_seq_next(tvb, 0, pinfo, pinfo->p2p_dir,
                                fragment_table, reassembled_table, tvb_length(tvb), TRUE);

            fragment_set_tot_len(pinfo, pinfo->p2p_dir, fragment_table, no_of_segments-1);

            new_tvb = process_reassembled_data(tvb, 0, pinfo,
                        "Reassembled Obex packet", frag_msg, &btobex_frag_items, NULL, tree);

            pinfo->fragmented = TRUE;
            }
        else if (tvb_length(tvb) == tvb_get_ntohs(tvb, offset+1)) {
            /* non-fragmented */
            complete = TRUE;
            pinfo->fragmented = FALSE;
        }
    }

    if (new_tvb) { /* take it all */
        next_tvb = new_tvb;
        complete = TRUE;
    }
    else { /* make a new subset */
        next_tvb = tvb_new_subset_remaining(tvb, offset);
    }

    if (complete) {
        guint8 code, final_flag;

        /* fully dissectable packet ready */
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "OBEX");

        ti = proto_tree_add_item(tree, proto_btobex, next_tvb, 0, -1, ENC_NA);
        st = proto_item_add_subtree(ti, ett_btobex);

        /* op/response code */
        code = tvb_get_guint8(next_tvb, offset) & BTOBEX_CODE_VALS_MASK;
        final_flag = tvb_get_guint8(next_tvb, offset) & 0x80;

        switch (pinfo->p2p_dir)
        {
        case P2P_DIR_SENT:
            col_add_fstr(pinfo->cinfo, COL_INFO, "Sent ");
            break;

        case P2P_DIR_RECV:
            col_add_fstr(pinfo->cinfo, COL_INFO, "Rcvd ");
            break;

        case P2P_DIR_UNKNOWN:
            break;

        default:
            col_add_fstr(pinfo->cinfo, COL_INFO, "Unknown direction %d ",
                pinfo->p2p_dir);
            break;
        }

        col_append_fstr(pinfo->cinfo, COL_INFO, "%s",
                        val_to_str_ext_const(code, &code_vals_ext, "Unknown"));

        if ((code < BTOBEX_CODE_VALS_CONTINUE) || (code == BTOBEX_CODE_VALS_ABORT)) {
            proto_tree_add_item(st, hf_opcode, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            if (pinfo->p2p_dir == P2P_DIR_SENT || pinfo->p2p_dir == P2P_DIR_RECV) {
                last_opcode[pinfo->p2p_dir] = code;
            }
            }
        else    {
            proto_tree_add_item(st, hf_response_code, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            }
        proto_tree_add_item(st, hf_final_flag, next_tvb, offset, 1, ENC_BIG_ENDIAN);
        offset++;

        /* length */
        proto_tree_add_item(st, hf_length, next_tvb, offset, 2, ENC_BIG_ENDIAN);
        offset += 2;

        switch(code)
        {
        case BTOBEX_CODE_VALS_CONNECT:
            proto_tree_add_item(st, hf_version, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            offset++;

            proto_tree_add_item(st, hf_flags, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            offset++;

            proto_tree_add_item(st, hf_max_pkt_len, next_tvb, offset, 2, ENC_BIG_ENDIAN);
            offset += 2;
            break;

        case BTOBEX_CODE_VALS_PUT:
        case BTOBEX_CODE_VALS_GET:
            col_append_fstr(pinfo->cinfo, COL_INFO, " %s",  (final_flag == 0x80) ? "final" : "continue");
            break;

        case BTOBEX_CODE_VALS_SET_PATH:
            proto_tree_add_item(st, hf_flags, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            proto_tree_add_item(st, hf_set_path_flags_0, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            proto_tree_add_item(st, hf_set_path_flags_1, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            offset++;

            proto_tree_add_item(st, hf_constants, next_tvb, offset, 1, ENC_BIG_ENDIAN);
            offset++;
            break;

        case BTOBEX_CODE_VALS_DISCONNECT:
        case BTOBEX_CODE_VALS_ABORT:
            break;

        default:
            {
                guint8 response_opcode = last_opcode[(pinfo->p2p_dir + 1) & 0x01];

                if (response_opcode == BTOBEX_CODE_VALS_CONNECT) {
                    proto_tree_add_item(st, hf_version, next_tvb, offset, 1, ENC_BIG_ENDIAN);
                    offset++;

                    proto_tree_add_item(st, hf_flags, next_tvb, offset, 1, ENC_BIG_ENDIAN);
                    offset++;

                    proto_tree_add_item(st, hf_max_pkt_len, next_tvb, offset, 2, ENC_BIG_ENDIAN);
                    offset += 2;
                }
            }
            break;
        }

        dissect_headers(st, next_tvb, offset, pinfo);
    }
    else
    {
        /* packet fragment */
        col_add_fstr(pinfo->cinfo, COL_INFO, "%s Obex fragment",
                     (pinfo->p2p_dir==P2P_DIR_SENT) ? "Sent" : "Rcvd");

        call_dissector(data_handle, next_tvb, pinfo, tree);
    }

    pinfo->fragmented = save_fragmented;
}
static int
dissect_gssapi_work(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
		    gboolean is_verifier)
{
	proto_item *volatile item;
	proto_tree *volatile subtree;
	volatile int return_offset = 0;
	gssapi_conv_info_t *volatile gss_info;
	gssapi_oid_value *oidvalue;
	dissector_handle_t handle;
	conversation_t *conversation;
	tvbuff_t *oid_tvb;
	int len, start_offset, oid_start_offset;
	volatile int offset;
	gint8 appclass;
	gboolean pc, ind_field;
	gint32 tag;
	guint32 len1;
	const char *oid;
	fragment_data *fd_head=NULL;
	gssapi_frag_info_t *fi;
	tvbuff_t *volatile gss_tvb=NULL;
	asn1_ctx_t asn1_ctx;
	void *pd_save;

	start_offset=0;
	offset=0;
	asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
	/*
	 * We don't know whether the data is encrypted, so say it's
	 * not, for now.  The subdissector must set gssapi_data_encrypted
	 * if it is.
	 */
	pinfo->gssapi_data_encrypted = FALSE;


	/*
	 * We need a conversation for later
	 */
	conversation = find_or_create_conversation(pinfo);

	gss_info = (gssapi_conv_info_t *)conversation_get_proto_data(conversation, proto_gssapi);
	if (!gss_info) {
		gss_info = se_new(gssapi_conv_info_t);
		gss_info->oid=NULL;
		gss_info->do_reassembly=FALSE;
		gss_info->frags=se_tree_create_non_persistent(EMEM_TREE_TYPE_RED_BLACK, "gssapi_frags");

		conversation_add_proto_data(conversation, proto_gssapi, gss_info);
	}

	item = proto_tree_add_item(
		tree, proto_gssapi, tvb, offset, -1, ENC_NA);

	subtree = proto_item_add_subtree(item, ett_gssapi);

	/*
	 * Catch the ReportedBoundsError exception; the stuff we've been
	 * handed doesn't necessarily run to the end of the packet, it's
	 * an item inside a packet, so if it happens to be malformed (or
	 * we, or a dissector we call, has a bug), so that an exception
	 * is thrown, we want to report the error, but return and let
	 * our caller dissect the rest of the packet.
	 *
	 * If it gets a BoundsError, we can stop, as there's nothing more
	 * in the packet after our blob to see, so we just re-throw the
	 * exception.
	 */
	pd_save = pinfo->private_data;
	TRY {
		gss_tvb=tvb;


		/* First of all, if it's the first time we see this packet
		 * then check whether we are in the middle of reassembly or not
		 */
		if( (!pinfo->fd->flags.visited)
		&&  (gss_info->do_reassembly)
		&&  (gssapi_reassembly) ){
			fi=(gssapi_frag_info_t *)se_tree_lookup32(gss_info->frags, gss_info->first_frame);
			if(!fi){
				goto done;
			}
			se_tree_insert32(gss_info->frags, pinfo->fd->num, fi);
			fd_head=fragment_add(&gssapi_reassembly_table,
				tvb, 0, pinfo, fi->first_frame, NULL,
				gss_info->frag_offset,
				tvb_length(tvb), TRUE);
			gss_info->frag_offset+=tvb_length(tvb);

			/* we need more fragments */
			if(!fd_head){
				goto done;
			}

			/* this blob is now fully reassembled */
			gss_info->do_reassembly=FALSE;
			fi->reassembled_in=pinfo->fd->num;

			gss_tvb=tvb_new_child_real_data(tvb, fd_head->data, fd_head->datalen, fd_head->datalen);
			add_new_data_source(pinfo, gss_tvb, "Reassembled GSSAPI");
		}
		/* We have seen this packet before.
		 * Is this blob part of reassembly or a normal blob ?
		 */
		if( (pinfo->fd->flags.visited)
		&&  (gssapi_reassembly) ){
			fi=(gssapi_frag_info_t *)se_tree_lookup32(gss_info->frags, pinfo->fd->num);
			if(fi){
				fd_head=fragment_get(&gssapi_reassembly_table,
					pinfo, fi->first_frame, NULL);
				if(fd_head && (fd_head->flags&FD_DEFRAGMENTED)){
					if(pinfo->fd->num==fi->reassembled_in){
					        proto_item *frag_tree_item;
						gss_tvb=tvb_new_child_real_data(tvb, fd_head->data, fd_head->datalen, fd_head->datalen);
						add_new_data_source(pinfo, gss_tvb, "Reassembled GSSAPI");
						show_fragment_tree(fd_head, &gssapi_frag_items, tree, pinfo, tvb, &frag_tree_item);
					} else {
						proto_item *it;
						it=proto_tree_add_uint(tree, hf_gssapi_reassembled_in, tvb, 0, 0, fi->reassembled_in);
					        PROTO_ITEM_SET_GENERATED(it);
						goto done;
					}
				}
			}
		}

		/* Read header */
		offset = get_ber_identifier(gss_tvb, offset, &appclass, &pc, &tag);
		offset = get_ber_length(gss_tvb, offset, &len1, &ind_field);


		if (!(appclass == BER_CLASS_APP && pc && tag == 0)) {
		  /* It could be NTLMSSP, with no OID.  This can happen
		     for anything that microsoft calls 'Negotiate' or GSS-SPNEGO */
			if ((tvb_length_remaining(gss_tvb, start_offset)>7) && (tvb_strneql(gss_tvb, start_offset, "NTLMSSP", 7) == 0)) {
				return_offset = call_dissector(ntlmssp_handle,
							tvb_new_subset_remaining(gss_tvb, start_offset),
							pinfo, subtree);
				goto done;
			}
			/* Maybe it's new NTLMSSP payload */
			if ((tvb_length_remaining(gss_tvb, start_offset)>16) &&
			   ((tvb_memeql(gss_tvb, start_offset, "\x01\x00\x00\x00", 4) == 0))) {
				return_offset = call_dissector(ntlmssp_payload_handle,
							tvb_new_subset_remaining(gss_tvb, start_offset),
							pinfo, subtree);
				pinfo->gssapi_data_encrypted = TRUE;
				goto done;
			}
			if ((tvb_length_remaining(gss_tvb, start_offset)==16) &&
			   ((tvb_memeql(gss_tvb, start_offset, "\x01\x00\x00\x00", 4) == 0))) {
				if( is_verifier ) {
					return_offset = call_dissector(ntlmssp_verf_handle,
									tvb_new_subset_remaining(gss_tvb, start_offset),
									pinfo, subtree);
				}
				else if( pinfo->gssapi_encrypted_tvb ) {
					return_offset = call_dissector(ntlmssp_data_only_handle,
									tvb_new_subset_remaining(pinfo->gssapi_encrypted_tvb, 0),
									pinfo, subtree);
					pinfo->gssapi_data_encrypted = TRUE;
				}
		   		goto done;
		  	}

		  /* Maybe it's new GSSKRB5 CFX Wrapping */
		  if ((tvb_length_remaining(gss_tvb, start_offset)>2) &&
		      ((tvb_memeql(gss_tvb, start_offset, "\04\x04", 2) == 0) ||
		       (tvb_memeql(gss_tvb, start_offset, "\05\x04", 2) == 0))) {
		    return_offset = call_dissector(spnego_krb5_wrap_handle,
						   tvb_new_subset_remaining(gss_tvb, start_offset),
						   pinfo, subtree);
		    goto done;
		  }

		  /*
		   * If we do not recognise an Application class,
		   * then we are probably dealing with an inner context
		   * token or a wrap token, and we should retrieve the
		   * gssapi_oid_value pointer from the per-frame data or,
		   * if there is no per-frame data (as would be the case
		   * the first time we dissect this frame), from the
		   * conversation that exists or that we created from
		   * pinfo (and then make it per-frame data).
		   * We need to make it per-frame data as there can be
		   * more than one GSS-API negotiation in a conversation.
		   *
		   * Note! We "cheat". Since we only need the pointer,
		   * we store that as the data.  (That's not really
		   * "cheating" - the per-frame data and per-conversation
		   * data code doesn't care what you supply as a data
		   * pointer; it just treats it as an opaque pointer, it
		   * doesn't dereference it or free what it points to.)
		   */
		  oidvalue = (gssapi_oid_value *)p_get_proto_data(pinfo->fd, proto_gssapi, 0);
		  if (!oidvalue && !pinfo->fd->flags.visited)
		  {
		    /* No handle attached to this frame, but it's the first */
		    /* pass, so it'd be attached to the conversation. */
		    oidvalue = gss_info->oid;
		    if (gss_info->oid)
		      p_add_proto_data(pinfo->fd, proto_gssapi, 0, gss_info->oid);
		  }
		  if (!oidvalue)
		  {
                    proto_tree_add_text(subtree, gss_tvb, start_offset, 0,
					  "Unknown header (class=%d, pc=%d, tag=%d)",
					  appclass, pc, tag);
		    return_offset = tvb_length(gss_tvb);
		    goto done;
		  } else {
		    tvbuff_t *oid_tvb_local;

		    oid_tvb_local = tvb_new_subset_remaining(gss_tvb, start_offset);
		    if (is_verifier)
			handle = oidvalue->wrap_handle;
		    else
			handle = oidvalue->handle;
		    len = call_dissector(handle, oid_tvb_local, pinfo, subtree);
		    if (len == 0)
			return_offset = tvb_length(gss_tvb);
		    else
			return_offset = start_offset + len;
		    goto done; /* We are finished here */
		  }
		}

		/* Read oid */
		oid_start_offset=offset;
		offset=dissect_ber_object_identifier_str(FALSE, &asn1_ctx, subtree, gss_tvb, offset, hf_gssapi_oid, &oid);
		oidvalue = gssapi_lookup_oid_str(oid);


		/* Check if we need reassembly of this blob.
		 * Only try reassembly for OIDs we recognize
		 * and when we have the entire tvb
		 *
		 * SMB will sometimes split one large GSSAPI blob
		 * across multiple SMB/SessionSetup commands.
		 * While we should look at the uid returned in the response
		 * to the first SessionSetup and use that as a key
		 * instead for simplicity we assume there will not be several
		 * such authentication at once on a single tcp session
		 */
		if( (!pinfo->fd->flags.visited)
		&&  (oidvalue)
		&&  (tvb_length(gss_tvb)==tvb_reported_length(gss_tvb))
		&&  (len1>(guint32)tvb_length_remaining(gss_tvb, oid_start_offset))
		&&  (gssapi_reassembly) ){
			fi=se_new(gssapi_frag_info_t);
			fi->first_frame=pinfo->fd->num;
			fi->reassembled_in=0;
			se_tree_insert32(gss_info->frags, pinfo->fd->num, fi);

			fragment_add(&gssapi_reassembly_table,
				gss_tvb, 0, pinfo, pinfo->fd->num, NULL,
				0, tvb_length(gss_tvb), TRUE);
			fragment_set_tot_len(&gssapi_reassembly_table,
				pinfo, pinfo->fd->num, NULL, len1+oid_start_offset);

			gss_info->do_reassembly=TRUE;
			gss_info->first_frame=pinfo->fd->num;
			gss_info->frag_offset=tvb_length(gss_tvb);
			goto done;
		}


		/*
		 * Hand off to subdissector.
		 */

		if ((oidvalue == NULL) ||
		    !proto_is_protocol_enabled(oidvalue->proto)) {
			/* No dissector for this oid */
			proto_tree_add_text(subtree, gss_tvb, oid_start_offset, -1,
					    "Token object");

			return_offset = tvb_length(gss_tvb);
			goto done;
		}

		/* Save a pointer to the data for the OID for the
		 * GSSAPI protocol for this conversation.
		 */

		/*
		 * Now add the proto data ...
		 * but only if it is not already there.
		 */
		if(!gss_info->oid){
		  gss_info->oid=oidvalue;
		}

		if (is_verifier) {
			handle = oidvalue->wrap_handle;
			if (handle != NULL) {
				oid_tvb = tvb_new_subset_remaining(gss_tvb, offset);
				len = call_dissector(handle, oid_tvb, pinfo,
				    subtree);
				if (len == 0)
					return_offset = tvb_length(gss_tvb);
				else
					return_offset = offset + len;
			} else {
				proto_tree_add_text(subtree, gss_tvb, offset, -1,
				    "Authentication verifier");
				return_offset = tvb_length(gss_tvb);
			}
		} else {
			handle = oidvalue->handle;
			if (handle != NULL) {
				oid_tvb = tvb_new_subset_remaining(gss_tvb, offset);
				len = call_dissector(handle, oid_tvb, pinfo,
				    subtree);
				if (len == 0)
					return_offset = tvb_length(gss_tvb);
				else
					return_offset = offset + len;
			} else {
				proto_tree_add_text(subtree, gss_tvb, offset, -1,
				    "Authentication credentials");
				return_offset = tvb_length(gss_tvb);
			}
		}

	 done:
		;
	} CATCH_NONFATAL_ERRORS {
		/*
		 * Somebody threw an exception that means that there
		 * was a problem dissecting the payload; that means
		 * that a dissector was found, so we don't need to
		 * dissect the payload as data or update the protocol
		 * or info columns.
		 *
		 * Just show the exception and then drive on to show
		 * the trailer, after noting that a dissector was found
		 * and restoring the protocol value that was in effect
		 * before we called the subdissector.
		 *
		 * Restore the private_data structure in case one of the
		 * called dissectors modified it (and, due to the exception,
		 * was unable to restore it).
		 */
		pinfo->private_data = pd_save;
		show_exception(gss_tvb, pinfo, tree, EXCEPT_CODE, GET_MESSAGE);
	} ENDTRY;

	proto_item_set_len(item, return_offset);
	return return_offset;
}
/* This tests the functionality of fragment_set_partial_reassembly for
 * FD_BLOCKSEQUENCE reassembly.
 *
 * We add a sequence of fragments thus:
 *    seqno   frame  offset   len   (initial) more_frags
 *    -----   -----  ------   ---   --------------------
 *      0       1       10       50   false
 *      1       2        0       40   true
 *      1       3        0       40   true (a duplicate fragment)
 *      2       4       20      100   false
 *      3       5        0       40   false
 */
static void test_fragment_add_seq_partial_reassembly(void)
{
    fragment_data *fd_head, *fd;

    printf("Starting test test_fragment_add_seq_partial_reassembly\n");

    /* generally it's probably fair to assume that we will be called with
     * more_frags=FALSE.
     */
    pinfo.fd->num = 1;
    fd_head=fragment_add_seq(tvb, 10, &pinfo, 12, fragment_table,
                             0, 50, FALSE);

    ASSERT_EQ(1,g_hash_table_size(fragment_table));
    ASSERT_NE(NULL,fd_head);

    /* check the contents of the structure */
    ASSERT_EQ(0,fd_head->frame);  /* unused */
    ASSERT_EQ(0,fd_head->offset); /* unused */
    ASSERT_EQ(50,fd_head->len); /* the length of data we have */
    ASSERT_EQ(0,fd_head->datalen); /* seqno of the last fragment we have */
    ASSERT_EQ(1,fd_head->reassembled_in);
    ASSERT_EQ(FD_DEFRAGMENTED|FD_BLOCKSEQUENCE|FD_DATALEN_SET,fd_head->flags);
    ASSERT_NE(NULL,fd_head->data);
    ASSERT_NE(NULL,fd_head->next);

    ASSERT_EQ(1,fd_head->next->frame);
    ASSERT_EQ(0,fd_head->next->offset);  /* seqno */
    ASSERT_EQ(50,fd_head->next->len);    /* segment length */
    ASSERT_EQ(0,fd_head->next->flags);
    ASSERT_EQ(NULL,fd_head->next->data);
    ASSERT_EQ(NULL,fd_head->next->next);

    /* test the actual reassembly */
    ASSERT(!memcmp(fd_head->data,data+10,50));

    /* now we announce that the reassembly wasn't complete after all. */
    fragment_set_partial_reassembly(&pinfo,12,fragment_table);

    /* and add another segment. To mix things up slightly (and so that we can
     * check on the state of things), we're going to set the more_frags flag
     * here
     */
    pinfo.fd->num = 2;
    fd_head=fragment_add_seq(tvb, 0, &pinfo, 12, fragment_table,
                             1, 40, TRUE);

    ASSERT_EQ(1,g_hash_table_size(fragment_table));
    ASSERT_EQ(NULL,fd_head);

    fd_head=fragment_get(&pinfo,12,fragment_table);
    ASSERT_NE(NULL,fd_head);

    /* check the contents of the structure */
    ASSERT_EQ(0,fd_head->frame);   /* unused */
    ASSERT_EQ(0,fd_head->offset);  /* unused */
    /* ASSERT_EQ(50,fd_head->len);     the length of data we have */
    ASSERT_EQ(0,fd_head->datalen); /* seqno of the last fragment we have */
    ASSERT_EQ(0,fd_head->reassembled_in);
    ASSERT_EQ(FD_BLOCKSEQUENCE,fd_head->flags);
    ASSERT_NE(NULL,fd_head->data);
    ASSERT_NE(NULL,fd_head->next);

    fd=fd_head->next;
    ASSERT_EQ(1,fd->frame);
    ASSERT_EQ(0,fd->offset);  /* seqno */
    ASSERT_EQ(50,fd->len);    /* segment length */
    ASSERT_EQ(FD_NOT_MALLOCED,fd->flags);
    ASSERT_EQ(fd_head->data,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(2,fd->frame);
    ASSERT_EQ(1,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_NE(NULL,fd->data);
    ASSERT_EQ(NULL,fd->next);

    /* Another copy of the second segment.
     */
    pinfo.fd->num = 3;
    fd_head=fragment_add_seq(tvb, 0, &pinfo, 12, fragment_table,
                             1, 40, TRUE);

    ASSERT_EQ(1,g_hash_table_size(fragment_table));
    ASSERT_EQ(NULL,fd_head);
    fd_head=fragment_get(&pinfo,12,fragment_table);
    ASSERT_NE(NULL,fd_head);
    ASSERT_EQ(0,fd_head->frame);   /* unused */
    ASSERT_EQ(0,fd_head->offset);  /* unused */
    /* ASSERT_EQ(50,fd_head->len);     the length of data we have */
    ASSERT_EQ(0,fd_head->datalen); /* seqno of the last fragment we have */
    ASSERT_EQ(0,fd_head->reassembled_in);
    ASSERT_EQ(FD_BLOCKSEQUENCE,fd_head->flags);
    ASSERT_NE(NULL,fd_head->data);
    ASSERT_NE(NULL,fd_head->next);

    fd=fd_head->next;
    ASSERT_EQ(1,fd->frame);
    ASSERT_EQ(0,fd->offset);  /* seqno */
    ASSERT_EQ(50,fd->len);    /* segment length */
    ASSERT_EQ(FD_NOT_MALLOCED,fd->flags);
    ASSERT_EQ(fd_head->data,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(2,fd->frame);
    ASSERT_EQ(1,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_NE(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(3,fd->frame);
    ASSERT_EQ(1,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_NE(NULL,fd->data);
    ASSERT_EQ(NULL,fd->next);



    /* have another go at wrapping things up */
    pinfo.fd->num = 4;
    fd_head=fragment_add_seq(tvb, 20, &pinfo, 12, fragment_table,
                             2, 100, FALSE);

    ASSERT_EQ(1,g_hash_table_size(fragment_table));
    ASSERT_NE(NULL,fd_head);

    /* check the contents of the structure */
    ASSERT_EQ(0,fd_head->frame);  /* unused */
    ASSERT_EQ(0,fd_head->offset); /* unused */
    ASSERT_EQ(190,fd_head->len); /* the length of data we have */
    ASSERT_EQ(2,fd_head->datalen); /* seqno of the last fragment we have */
    ASSERT_EQ(4,fd_head->reassembled_in);
    ASSERT_EQ(FD_DEFRAGMENTED|FD_BLOCKSEQUENCE|FD_DATALEN_SET|FD_OVERLAP,fd_head->flags);
    ASSERT_NE(NULL,fd_head->data);
    ASSERT_NE(NULL,fd_head->next);

    fd=fd_head->next;
    ASSERT_EQ(1,fd->frame);
    ASSERT_EQ(0,fd->offset);  /* seqno */
    ASSERT_EQ(50,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(2,fd->frame);
    ASSERT_EQ(1,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(3,fd->frame);
    ASSERT_EQ(1,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(FD_OVERLAP,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(4,fd->frame);
    ASSERT_EQ(2,fd->offset);  /* seqno */
    ASSERT_EQ(100,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_EQ(NULL,fd->next);

    /* test the actual reassembly */
    ASSERT(!memcmp(fd_head->data,data+10,50));
    ASSERT(!memcmp(fd_head->data+50,data,40));
    ASSERT(!memcmp(fd_head->data+90,data+20,100));


    /* do it again (this time it is more complicated, with an overlap in the
     * reassembly) */

    fragment_set_partial_reassembly(&pinfo,12,fragment_table);

    pinfo.fd->num = 5;
    fd_head=fragment_add_seq(tvb, 0, &pinfo, 12, fragment_table,
                             3, 40, FALSE);

    fd_head=fragment_get(&pinfo,12,fragment_table);
    ASSERT_NE(NULL,fd_head);
    ASSERT_EQ(0,fd_head->frame);   /* unused */
    ASSERT_EQ(0,fd_head->offset);  /* unused */
    ASSERT_EQ(230,fd_head->len);   /* the length of data we have */
    ASSERT_EQ(3,fd_head->datalen); /* seqno of the last fragment we have */
    ASSERT_EQ(5,fd_head->reassembled_in);
    ASSERT_EQ(FD_DEFRAGMENTED|FD_BLOCKSEQUENCE|FD_DATALEN_SET|FD_OVERLAP,fd_head->flags);
    ASSERT_NE(NULL,fd_head->data);
    ASSERT_NE(NULL,fd_head->next);

    fd=fd_head->next;
    ASSERT_EQ(1,fd->frame);
    ASSERT_EQ(0,fd->offset);  /* seqno */
    ASSERT_EQ(50,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(2,fd->frame);
    ASSERT_EQ(1,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(3,fd->frame);
    ASSERT_EQ(1,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(FD_OVERLAP,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(4,fd->frame);
    ASSERT_EQ(2,fd->offset);  /* seqno */
    ASSERT_EQ(100,fd->len);   /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_NE(NULL,fd->next);

    fd=fd->next;
    ASSERT_EQ(5,fd->frame);
    ASSERT_EQ(3,fd->offset);  /* seqno */
    ASSERT_EQ(40,fd->len);    /* segment length */
    ASSERT_EQ(0,fd->flags);
    ASSERT_EQ(NULL,fd->data);
    ASSERT_EQ(NULL,fd->next);

    /* test the actual reassembly */
    ASSERT(!memcmp(fd_head->data,data+10,50));
    ASSERT(!memcmp(fd_head->data+50,data,40));
    ASSERT(!memcmp(fd_head->data+90,data+20,100));
    ASSERT(!memcmp(fd_head->data+190,data,40));
}