Ejemplo n.º 1
0
static void
dissect_pgmopts(ptvcursor_t* cursor, const char *pktname)
{
	proto_item *tf;
	proto_tree *opts_tree = NULL;
	proto_tree *opt_tree = NULL;
	tvbuff_t *tvb = ptvcursor_tvbuff(cursor);

	gboolean theend = FALSE;

	guint16 opts_total_len;
	guint8 genopts_type;
	guint8 genopts_len;
	guint8 opts_type = tvb_get_guint8(tvb, ptvcursor_current_offset(cursor));

	if (opts_type != PGM_OPT_LENGTH) {
		proto_tree_add_text(ptvcursor_tree(cursor), tvb, ptvcursor_current_offset(cursor), 1,
		    "%s Options - initial option is %s, should be %s",
		    pktname,
		    val_to_str(opts_type, opt_vals, "Unknown (0x%02x)"),
		    val_to_str(PGM_OPT_LENGTH, opt_vals, "Unknown (0x%02x)"));
		return;
	}

	opts_total_len = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor)+2);

	if (opts_total_len < 4) {
		proto_tree_add_text(opts_tree, tvb, ptvcursor_current_offset(cursor)+2, 2,
			"%s Options (Total Length %u - invalid, must be >= 4)",
			pktname, opts_total_len);
		return;
	}

	tf = proto_tree_add_text(ptvcursor_tree(cursor), tvb, ptvcursor_current_offset(cursor), opts_total_len,
		"%s Options (Total Length %d)", pktname, opts_total_len);
	opts_tree = proto_item_add_subtree(tf, ett_pgm_opts);
	ptvcursor_set_tree(cursor, opts_tree);
	ptvcursor_add(cursor, hf_pgm_opt_type, 1, ENC_BIG_ENDIAN);
	ptvcursor_add(cursor, hf_pgm_opt_len, 1, ENC_BIG_ENDIAN);
	ptvcursor_add(cursor, hf_pgm_opt_tlen, 2, ENC_BIG_ENDIAN);

	for (opts_total_len -= 4; !theend && opts_total_len != 0;){
		if (opts_total_len < 4) {
			proto_tree_add_text(opts_tree, tvb, ptvcursor_current_offset(cursor), opts_total_len,
			    "Remaining total options length doesn't have enough for an options header");
			break;
		}

		genopts_type = tvb_get_guint8(tvb, ptvcursor_current_offset(cursor));
		genopts_len = tvb_get_guint8(tvb, ptvcursor_current_offset(cursor)+1);

		if (genopts_type & PGM_OPT_END)  {
			genopts_type &= ~PGM_OPT_END;
			theend = TRUE;
		}
		if (genopts_len < 4) {
			proto_tree_add_text(opts_tree, tvb, ptvcursor_current_offset(cursor), genopts_len,
				"Option: %s, Length: %u (invalid, must be >= 4)",
				val_to_str(genopts_type, opt_vals, "Unknown (0x%02x)"),
				genopts_len);
			break;
		}
		if (opts_total_len < genopts_len) {
			proto_tree_add_text(opts_tree, tvb, ptvcursor_current_offset(cursor), genopts_len,
			    "Option: %s, Length: %u (> remaining total options length)",
			    val_to_str(genopts_type, opt_vals, "Unknown (0x%02x)"),
			    genopts_len);
			break;
		}
		tf = proto_tree_add_text(opts_tree, tvb, ptvcursor_current_offset(cursor), genopts_len,
			"Option: %s, Length: %u",
			val_to_str(genopts_type, opt_vals, "Unknown (0x%02x)"),
			genopts_len);

		switch(genopts_type) {
		case PGM_OPT_JOIN:{
			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_join);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_JOIN_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_JOIN_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_join_res, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_join_minjoin, 4, ENC_BIG_ENDIAN);

			break;
		}
		case PGM_OPT_PARITY_PRM:{
			guint8 optdata_po;

			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_parityprm);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);


			if (genopts_len < PGM_OPT_PARITY_PRM_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, ptvcursor_tvbuff(cursor),
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_PARITY_PRM_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			optdata_po = tvb_get_guint8(tvb, ptvcursor_current_offset(cursor));
			proto_tree_add_uint_format(opt_tree, hf_pgm_opt_parity_prm_po, tvb,
				ptvcursor_current_offset(cursor), 1, optdata_po, "Parity Parameters: %s (0x%x)",
				paritystr(optdata_po), optdata_po);
			ptvcursor_advance(cursor, 1);

			ptvcursor_add(cursor, hf_pgm_opt_parity_prm_prmtgsz, 4, ENC_BIG_ENDIAN);

			break;
		}
		case PGM_OPT_PARITY_GRP:{
			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_paritygrp);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_PARITY_GRP_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_PARITY_GRP_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_parity_grp_res, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_parity_grp_prmgrp, 4, ENC_BIG_ENDIAN);

			break;
		}
		case PGM_OPT_NAK_LIST:{
			guint8 optdata_len;
			guint32 naklist[PGM_MAX_NAK_LIST_SZ+1];
			unsigned char *nakbuf;
			gboolean firsttime;
			int i, j, naks, soffset;

			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_naklist);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			optdata_len = tvb_get_guint8(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_nak_res, 1, ENC_BIG_ENDIAN);

			optdata_len -= PGM_OPT_NAK_LIST_SIZE;
			tvb_memcpy(tvb, (guint8 *)naklist, ptvcursor_current_offset(cursor), optdata_len);
			firsttime = TRUE;
			soffset = 0;
			naks = (optdata_len/sizeof(guint32));
			nakbuf = ep_alloc(8192);
			j = 0;
			/*
			 * Print out 8 per line
			 */
			for (i=0; i < naks; i++) {
				soffset += MIN(8192-soffset,
					g_snprintf(nakbuf+soffset, 8192-soffset, "0x%lx ",
						(unsigned long)g_ntohl(naklist[i])));
				if ((++j % 8) == 0) {
					if (firsttime) {
						proto_tree_add_bytes_format(opt_tree,
							hf_pgm_opt_nak_list, tvb, ptvcursor_current_offset(cursor), j*4,
							nakbuf, "List(%d): %s", naks, nakbuf);
						soffset = 0;
						firsttime = FALSE;
					} else {
						proto_tree_add_bytes_format(opt_tree,
							hf_pgm_opt_nak_list, tvb, ptvcursor_current_offset(cursor), j*4,
							nakbuf, "List: %s", nakbuf);
						soffset = 0;
					}
					ptvcursor_advance(cursor, j*4);
					j = 0;
				}
			}
			if (j) {
				if (firsttime) {
					proto_tree_add_bytes_format(opt_tree,
						hf_pgm_opt_nak_list, tvb, ptvcursor_current_offset(cursor), j*4,
						nakbuf, "List(%d): %s", naks, nakbuf);
				} else {
					proto_tree_add_bytes_format(opt_tree,
						hf_pgm_opt_nak_list, tvb, ptvcursor_current_offset(cursor), j*4,
						nakbuf, "List: %s", nakbuf);
				}
				ptvcursor_advance(cursor, j*4);
			}
			break;
		}
		case PGM_OPT_PGMCC_DATA:{
			guint16 optdata_afi;

			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_ccdata);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_PGMCC_DATA_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_PGMCC_DATA_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_ccdata_res, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_ccdata_tsp, 4, ENC_BIG_ENDIAN);
			optdata_afi = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_opt_ccdata_afi, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_ccdata_res2, 2, ENC_BIG_ENDIAN);

			switch (optdata_afi) {

			case AFNUM_INET:
				ptvcursor_add(cursor, hf_pgm_opt_ccdata_acker, 4, ENC_BIG_ENDIAN);
				break;

			case AFNUM_INET6:
				ptvcursor_add(cursor, hf_pgm_opt_ccdata_acker6, 16, ENC_NA);
				break;

			default:
				proto_tree_add_text(opt_tree, tvb, ptvcursor_current_offset(cursor), -1,
				    "Can't handle this address format");
				break;
			}

			break;
		}
		case PGM_OPT_PGMCC_FEEDBACK:{
			guint16 optdata_afi;

			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_ccdata);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_PGMCC_FEEDBACK_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_PGMCC_FEEDBACK_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_ccfeedbk_res, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_ccfeedbk_tsp, 4, ENC_BIG_ENDIAN);
			optdata_afi = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_opt_ccfeedbk_afi, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_ccfeedbk_lossrate, 2, ENC_BIG_ENDIAN);

			switch (optdata_afi) {

			case AFNUM_INET:
				ptvcursor_add(cursor, hf_pgm_opt_ccfeedbk_acker, 4, ENC_BIG_ENDIAN);
				break;

			case AFNUM_INET6:
				ptvcursor_add(cursor, hf_pgm_opt_ccfeedbk_acker6, 16, ENC_NA);
				break;

			default:
				proto_tree_add_text(opt_tree, tvb, ptvcursor_current_offset(cursor), -1,
				    "Can't handle this address format");
				break;
			}

			break;
		}
		case PGM_OPT_NAK_BO_IVL:{
			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_nak_bo_ivl);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_NAK_BO_IVL_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_NAK_BO_IVL_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_nak_bo_ivl_res, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_nak_bo_ivl_bo_ivl, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_nak_bo_ivl_bo_ivl_sqn, 4, ENC_BIG_ENDIAN);

			break;
		}
		case PGM_OPT_NAK_BO_RNG:{
			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_nak_bo_rng);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_NAK_BO_RNG_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_NAK_BO_RNG_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_nak_bo_rng_res, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_nak_bo_rng_min_bo_ivl, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_nak_bo_rng_max_bo_ivl, 4, ENC_BIG_ENDIAN);

			break;
		}
		case PGM_OPT_REDIRECT:{
			guint16 optdata_afi;

			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_redirect);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_REDIRECT_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_REDIRECT_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_redirect_res, 1, ENC_BIG_ENDIAN);
			optdata_afi = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_opt_redirect_afi, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_redirect_res2, 2, ENC_BIG_ENDIAN);

			switch (optdata_afi) {

			case AFNUM_INET:
				ptvcursor_add(cursor, hf_pgm_opt_redirect_dlr, 4, ENC_BIG_ENDIAN);
				break;

			case AFNUM_INET6:
				ptvcursor_add(cursor, hf_pgm_opt_redirect_dlr6, 16, ENC_NA);
				break;

			default:
				proto_tree_add_text(opt_tree, tvb, ptvcursor_current_offset(cursor), -1,
				    "Can't handle this address format");
				break;
			}

			break;
		}
		case PGM_OPT_FRAGMENT:{
			opt_tree = proto_item_add_subtree(tf, ett_pgm_opts_fragment);
			ptvcursor_set_tree(cursor, opt_tree);

			ptvcursor_add_no_advance(cursor, hf_pgm_genopt_end, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_type, 1, ENC_BIG_ENDIAN);

			if (genopts_len < PGM_OPT_FRAGMENT_SIZE) {
				proto_tree_add_uint_format(opt_tree, hf_pgm_genopt_len, tvb,
					ptvcursor_current_offset(cursor), 1, genopts_len,
					"Length: %u (bogus, must be >= %u)",
					genopts_len, PGM_OPT_FRAGMENT_SIZE);
				break;
			}
			ptvcursor_add(cursor, hf_pgm_genopt_len, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_genopt_opx, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_fragment_res, 1, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_fragment_first_sqn, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_fragment_offset, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_opt_fragment_total_length, 4, ENC_BIG_ENDIAN);

			break;
		}
		default:{
			ptvcursor_advance(cursor, genopts_len);
			break;
		}
		}

		opts_total_len -= genopts_len;
	}
	return;
}
Ejemplo n.º 2
0
/*
 * dissect_pgm - The dissector for Pragmatic General Multicast
 */
static void
dissect_pgm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	guint16 pgmhdr_sport;
	guint16 pgmhdr_dport;
	guint8 pgmhdr_type;
	guint8 pgmhdr_opts;
	guint16 pgmhdr_cksum;
	guint16 pgmhdr_tsdulen;
	guint32 sqn;
	guint16 afi;

	guint plen = 0;
	proto_item *ti;
	const char *pktname;
	const char *pollstname;
	char *gsi;
	gboolean isdata = FALSE;
	guint pgmlen, reportedlen;

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "PGM");

	if (check_col(pinfo->cinfo, COL_INFO)) {
		col_clear(pinfo->cinfo, COL_INFO);
		if (tvb_reported_length_remaining(tvb, 0) < 18) {
			col_set_str(pinfo->cinfo, COL_INFO,
				"Packet too small");
			return;
		}
	}

	pinfo->srcport = pgmhdr_sport = tvb_get_ntohs(tvb, 0);
	pinfo->destport = pgmhdr_dport = tvb_get_ntohs(tvb, 2);

	pgmhdr_type = tvb_get_guint8(tvb, 4);
	pktname = val_to_str(pgmhdr_type, type_vals, "Unknown (0x%02x)");

	pgmhdr_opts = tvb_get_guint8(tvb, 5);
	pgmhdr_cksum = tvb_get_ntohs(tvb, 6);
	gsi = tvb_bytes_to_str(tvb, 8, 6);
	pgmhdr_tsdulen = tvb_get_ntohs(tvb, 14);
	sqn = tvb_get_ntohl(tvb, 16);

	switch(pgmhdr_type) {
	case PGM_SPM_PCKT:
	case PGM_NAK_PCKT:
	case PGM_NNAK_PCKT:
	case PGM_NCF_PCKT:
	case PGM_POLR_PCKT:
	case PGM_ACK_PCKT:
		if (check_col(pinfo->cinfo, COL_INFO)) {
			col_add_fstr(pinfo->cinfo, COL_INFO,
				"%-5s sqn 0x%x gsi %s", pktname, sqn, gsi);
		}
		break;
	case PGM_RDATA_PCKT:
	case PGM_ODATA_PCKT:
		if (check_col(pinfo->cinfo, COL_INFO)) {
			col_add_fstr(pinfo->cinfo, COL_INFO,
			    "%-5s sqn 0x%x gsi %s tsdulen %d", pktname, sqn, gsi,
			    pgmhdr_tsdulen);
		}
		isdata = TRUE;
		break;
	case PGM_POLL_PCKT: {
		guint16 poll_stype = tvb_get_ntohs(tvb, 22);
		pollstname = val_to_str(poll_stype, poll_subtype_vals, "Unknown (0x%02x)");

		if (check_col(pinfo->cinfo, COL_INFO)) {
			col_add_fstr(pinfo->cinfo, COL_INFO,
				"%-5s sqn 0x%x gsi %s subtype %s",
					pktname, sqn, gsi, pollstname);
		}
		}
		break;
	default:
		return;
	}

	{
		proto_tree *pgm_tree = NULL;
		proto_tree *opt_tree = NULL;
		proto_tree *type_tree = NULL;
		proto_item *tf, *hidden_item;
		ptvcursor_t* cursor;

		ti = proto_tree_add_protocol_format(tree, proto_pgm,
			tvb, 0, -1,
			"Pragmatic General Multicast: Type %s"
			    " Src Port %u, Dst Port %u, GSI %s", pktname,
			pgmhdr_sport, pgmhdr_dport, gsi);

		pgm_tree = proto_item_add_subtree(ti, ett_pgm);

		cursor = ptvcursor_new(pgm_tree, tvb, 0);

		hidden_item = proto_tree_add_item(pgm_tree, hf_pgm_port, tvb, 0, 2, ENC_BIG_ENDIAN);
		PROTO_ITEM_SET_HIDDEN(hidden_item);
		hidden_item = proto_tree_add_item(pgm_tree, hf_pgm_port, tvb, 2, 2, ENC_BIG_ENDIAN);
		PROTO_ITEM_SET_HIDDEN(hidden_item);
		ptvcursor_add(cursor, hf_pgm_main_sport, 2, ENC_BIG_ENDIAN);
		ptvcursor_add(cursor, hf_pgm_main_dport, 2, ENC_BIG_ENDIAN);
		ptvcursor_add(cursor, hf_pgm_main_type, 1, ENC_BIG_ENDIAN);

		tf = proto_tree_add_uint_format(pgm_tree, hf_pgm_main_opts, tvb,
			ptvcursor_current_offset(cursor), 1, pgmhdr_opts, "Options: %s (0x%x)",
			optsstr(pgmhdr_opts), pgmhdr_opts);
		opt_tree = proto_item_add_subtree(tf, ett_pgm_optbits);
		ptvcursor_set_tree(cursor, opt_tree);

		ptvcursor_add_no_advance(cursor, hf_pgm_main_opts_opt, 1, ENC_BIG_ENDIAN);
		ptvcursor_add_no_advance(cursor, hf_pgm_main_opts_netsig, 1, ENC_BIG_ENDIAN);
		ptvcursor_add_no_advance(cursor, hf_pgm_main_opts_varlen, 1, ENC_BIG_ENDIAN);
		ptvcursor_add(cursor, hf_pgm_main_opts_parity, 1, ENC_BIG_ENDIAN);
		ptvcursor_set_tree(cursor, pgm_tree);

		/* Checksum may be 0 (not available), but not for DATA packets */
		if ((pgmhdr_type != PGM_RDATA_PCKT) && (pgmhdr_type != PGM_ODATA_PCKT) &&
		    (pgmhdr_cksum == 0))
		{
			proto_tree_add_uint_format(pgm_tree, hf_pgm_main_cksum, tvb,
				ptvcursor_current_offset(cursor), 2, pgmhdr_cksum, "Checksum: not available");
		} else {
			reportedlen = tvb_reported_length(tvb);
			pgmlen = tvb_length(tvb);
			if (pgm_check_checksum && pgmlen >= reportedlen) {
				vec_t cksum_vec[1];
				guint16 computed_cksum;

				cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, pgmlen);
				cksum_vec[0].len = pgmlen;
				computed_cksum = in_cksum(&cksum_vec[0], 1);
				if (computed_cksum == 0) {
					proto_tree_add_uint_format(pgm_tree, hf_pgm_main_cksum, tvb,
						ptvcursor_current_offset(cursor), 2, pgmhdr_cksum, "Checksum: 0x%04x [correct]", pgmhdr_cksum);
				} else {
					hidden_item = proto_tree_add_boolean(pgm_tree, hf_pgm_main_cksum_bad, tvb,
					    ptvcursor_current_offset(cursor), 2, TRUE);
					PROTO_ITEM_SET_HIDDEN(hidden_item);
					proto_tree_add_uint_format(pgm_tree, hf_pgm_main_cksum, tvb,
					    ptvcursor_current_offset(cursor), 2, pgmhdr_cksum, "Checksum: 0x%04x [incorrect, should be 0x%04x]",
						pgmhdr_cksum, in_cksum_shouldbe(pgmhdr_cksum, computed_cksum));
				}
			} else {
				ptvcursor_add_no_advance(cursor, hf_pgm_main_cksum, 2, ENC_BIG_ENDIAN);
			}
		}
		ptvcursor_advance(cursor, 2);

		ptvcursor_add(cursor, hf_pgm_main_gsi, 6, ENC_NA);
		ptvcursor_add(cursor, hf_pgm_main_tsdulen, 2, ENC_BIG_ENDIAN);

		tf = proto_tree_add_text(pgm_tree, tvb, ptvcursor_current_offset(cursor), plen, "%s Packet", pktname);
		switch(pgmhdr_type) {
		case PGM_SPM_PCKT:
			type_tree = proto_item_add_subtree(tf, ett_pgm_spm);
			ptvcursor_set_tree(cursor, type_tree);

			ptvcursor_add(cursor, hf_pgm_spm_sqn, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_spm_trail, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_spm_lead, 4, ENC_BIG_ENDIAN);
			afi = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_spm_pathafi, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_spm_res, 2, ENC_BIG_ENDIAN);

			switch (afi) {
			case AFNUM_INET:
				ptvcursor_add(cursor, hf_pgm_spm_path, 4, ENC_BIG_ENDIAN);
				break;

			case AFNUM_INET6:
				ptvcursor_add(cursor, hf_pgm_spm_path6, 16, ENC_NA);
				break;

			default:
				proto_tree_add_text(type_tree, tvb, ptvcursor_current_offset(cursor), -1,
				    "Can't handle this address format");
				return;
			}
			break;
		case PGM_RDATA_PCKT:
		case PGM_ODATA_PCKT:
			type_tree = proto_item_add_subtree(tf, ett_pgm_data);
			ptvcursor_set_tree(cursor, type_tree);

			ptvcursor_add(cursor, hf_pgm_spm_sqn, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_spm_trail, 4, ENC_BIG_ENDIAN);
			break;
		case PGM_NAK_PCKT:
		case PGM_NNAK_PCKT:
		case PGM_NCF_PCKT:
			type_tree = proto_item_add_subtree(tf, ett_pgm_nak);
			ptvcursor_set_tree(cursor, type_tree);

			ptvcursor_add(cursor, hf_pgm_nak_sqn, 4, ENC_BIG_ENDIAN);
			afi = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_nak_srcafi, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_nak_srcres, 2, ENC_BIG_ENDIAN);

			switch (afi) {
			case AFNUM_INET:
				ptvcursor_add(cursor, hf_pgm_nak_src, 4, ENC_BIG_ENDIAN);
				break;

			case AFNUM_INET6:
				ptvcursor_add(cursor, hf_pgm_nak_src6, 16, ENC_NA);
				break;

			default:
				proto_tree_add_text(type_tree, tvb, ptvcursor_current_offset(cursor), -1,
				    "Can't handle this address format");
				break;
			}

			afi = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_nak_grpafi, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_nak_grpres, 2, ENC_BIG_ENDIAN);

			switch (afi) {
			case AFNUM_INET:
				ptvcursor_add(cursor, hf_pgm_nak_grp, 4, ENC_BIG_ENDIAN);
				break;

			case AFNUM_INET6:
				ptvcursor_add(cursor, hf_pgm_nak_grp6, 16, ENC_NA);
				break;

			default:
				proto_tree_add_text(type_tree, tvb, ptvcursor_current_offset(cursor), -1,
				    "Can't handle this address format");
				return;
			}
			break;
		case PGM_POLL_PCKT:
			type_tree = proto_item_add_subtree(tf, ett_pgm_poll);
			ptvcursor_set_tree(cursor, type_tree);

			ptvcursor_add(cursor, hf_pgm_poll_sqn, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_poll_round, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_poll_subtype, 2, ENC_BIG_ENDIAN);
			afi = tvb_get_ntohs(tvb, ptvcursor_current_offset(cursor));
			ptvcursor_add(cursor, hf_pgm_poll_pathafi, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_poll_res, 2, ENC_BIG_ENDIAN);

			switch (afi) {
			case AFNUM_INET:
				ptvcursor_add(cursor, hf_pgm_poll_path, 4, ENC_BIG_ENDIAN);
				break;

			case AFNUM_INET6:
				ptvcursor_add(cursor, hf_pgm_poll_path6, 16, ENC_NA);
				break;

			default:
				proto_tree_add_text(type_tree, tvb, ptvcursor_current_offset(cursor), -1,
				    "Can't handle this address format");
				break;
			}

			ptvcursor_add(cursor, hf_pgm_poll_backoff_ivl, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_poll_rand_str, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_poll_matching_bmask, 4, ENC_BIG_ENDIAN);
			break;
		case PGM_POLR_PCKT:
			type_tree = proto_item_add_subtree(tf, ett_pgm_polr);
			ptvcursor_set_tree(cursor, type_tree);

			ptvcursor_add(cursor, hf_pgm_polr_sqn, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_polr_round, 2, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_polr_res, 2, ENC_BIG_ENDIAN);
			break;
		case PGM_ACK_PCKT:
			type_tree = proto_item_add_subtree(tf, ett_pgm_ack);
			ptvcursor_set_tree(cursor, type_tree);

			ptvcursor_add(cursor, hf_pgm_ack_sqn, 4, ENC_BIG_ENDIAN);
			ptvcursor_add(cursor, hf_pgm_ack_bitmap, 4, ENC_BIG_ENDIAN);
			break;
		}

		if (pgmhdr_opts & PGM_OPT)
			dissect_pgmopts(cursor, pktname);

		if (isdata)
			decode_pgm_ports(tvb, ptvcursor_current_offset(cursor), pinfo, tree, pgmhdr_sport, pgmhdr_dport);
	}
}
static int dissect_op_uavtalk(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    gint offset   = 0;

    guint8 packet_type = tvb_get_guint8(tvb, 1) & 0x7;
    guint32 objid = tvb_get_letohl(tvb, 4);
    guint32 payload_length  = tvb_get_letohs(tvb, 2) - UAVTALK_HEADER_SIZE - UAVTALK_TRAILER_SIZE;
    guint32 reported_length = tvb_reported_length(tvb);

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "UAVTALK");
    /* Clear out stuff in the info column */
    col_clear(pinfo->cinfo, COL_INFO);

    col_append_fstr(pinfo->cinfo, COL_INFO, "%s: 0x%08x", val_to_str_const(packet_type, uavtalk_packet_types, ""), objid);
    if (objid & 0x1) {
        col_append_str(pinfo->cinfo, COL_INFO, "(META)");
    }


    if (tree) { /* we are being asked for details */
        proto_tree *op_uavtalk_tree = NULL;
        ptvcursor_t *cursor;
        proto_item *ti = NULL;

        /* Add a top-level entry to the dissector tree for this protocol */
        ti = proto_tree_add_item(tree, proto_op_uavtalk, tvb, 0, -1, ENC_NA);

        /* Create a subtree to contain the dissection of this protocol */
        op_uavtalk_tree = proto_item_add_subtree(ti, ett_op_uavtalk);

        /* Dissect the packet and populate the subtree */
        cursor = ptvcursor_new(op_uavtalk_tree, tvb, 0);

        /* Populate the fields in this protocol */
        ptvcursor_add(cursor, hf_op_uavtalk_sync, 1, ENC_LITTLE_ENDIAN);
        ptvcursor_add_no_advance(cursor, hf_op_uavtalk_version, 1, ENC_LITTLE_ENDIAN);
        ptvcursor_add(cursor, hf_op_uavtalk_type, 1, ENC_LITTLE_ENDIAN);
        ptvcursor_add(cursor, hf_op_uavtalk_len, 2, ENC_LITTLE_ENDIAN);
        ptvcursor_add(cursor, hf_op_uavtalk_objid, 4, ENC_LITTLE_ENDIAN);

        offset = ptvcursor_current_offset(cursor);

        ptvcursor_free(cursor);

        proto_tree_add_item(op_uavtalk_tree, hf_op_uavtalk_crc8, tvb, reported_length - UAVTALK_TRAILER_SIZE, UAVTALK_TRAILER_SIZE, ENC_LITTLE_ENDIAN);
    } else {
        offset = UAVTALK_HEADER_SIZE;
    }

    {
        tvbuff_t *next_tvb = tvb_new_subset(tvb, offset,
                                            reported_length - UAVTALK_HEADER_SIZE - UAVTALK_TRAILER_SIZE,
                                            payload_length);

        /* Check if we have an embedded objid to decode */
        if ((packet_type == 0) || (packet_type == 2)) {
            /* Call any registered subdissector for this objid */
            if (!dissector_try_uint(uavtalk_subdissector_table, objid, next_tvb, pinfo, tree)) {
                /* No subdissector registered, use the default data dissector */
                call_dissector(data_handle, next_tvb, pinfo, tree);
            }
        } else {
            /* Render any remaining data as raw bytes */
            call_dissector(data_handle, next_tvb, pinfo, tree);
        }
    }

    return UAVTALK_HEADER_SIZE + UAVTALK_TRAILER_SIZE;
}