forked from osmocom/wireshark
DVB-S2-BB: Fix GSE reassembly
Fix several issues with GSE reassembly: Use the Input Stream Identifier (ISI) to distinguish packets on different input streams, when present. Take into account the label, if present, when reassembling. Also don't send partially reassembled packets to subdissectors, but show the bytes as undecoded PDU data in the fragment if reassembly did not complete. (All this fixes #17403.) Also include the Total Length field when reassembling, since it is included in the CRC32 calculation. Check the CRC32 in completed reassemblies. Deal with reassembly issues arising from pinfo->src, dst, etc. changing from subdissectors (since GSE oft carries IP.) Require that reassemblies begin with Start packets, and don't add Start packets to in progress reassemblies but rather start a new one.
This commit is contained in:
John Thacker
Wireshark GitLab Utility
parent
9bd450f507
commit
1b32a71f2b
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@ -40,9 +40,12 @@
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#include <epan/packet.h>
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#include <epan/prefs.h>
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#include <epan/crc32-tvb.h>
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#include <epan/etypes.h>
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#include <epan/expert.h>
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#include <epan/reassemble.h>
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#include <epan/conversation.h>
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#include <epan/proto_data.h>
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#define BIT_IS_SET(var, bit) ((var) & (1 << (bit)))
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#define BIT_IS_CLEAR(var, bit) !BIT_IS_SET(var, bit)
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@ -149,6 +152,7 @@ static int hf_dvb_s2_gse_exthdr = -1;
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static int hf_dvb_s2_gse_ncr = -1;
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static int hf_dvb_s2_gse_data = -1;
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static int hf_dvb_s2_gse_crc32 = -1;
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static int hf_dvb_s2_gse_crc32_status = -1;
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/* Initialize the subtree pointers */
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static gint ett_dvb_s2_modeadapt = -1;
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@ -168,6 +172,10 @@ static expert_field ei_dvb_s2_bb_npd_invalid = EI_INIT;
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static expert_field ei_dvb_s2_bb_upl_invalid = EI_INIT;
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static expert_field ei_dvb_s2_bb_reserved = EI_INIT;
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static expert_field ei_dvb_s2_gse_length_invalid = EI_INIT;
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static expert_field ei_dvb_s2_gse_totlength_invalid = EI_INIT;
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static expert_field ei_dvb_s2_gse_crc32 = EI_INIT;
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/* Reassembly support */
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static reassembly_table dvbs2_reassembly_table;
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@ -849,8 +857,7 @@ static const value_string bb_low_ro[] = {
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#define DVB_S2_GSE_HDR_LABELTYPE_MASK 0x3000
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#define DVB_S2_GSE_HDR_LABELTYPE_POS1 13
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#define DVB_S2_GSE_HDR_LABELTYPE_POS2 12
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#define DVB_S2_GSE_HDR_LABELTYPE_SHIFT 12
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static const value_string gse_labeltype[] = {
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{0, "6 byte"},
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{1, "3 byte"},
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@ -894,6 +901,96 @@ static const value_string gse_proto_next_header_str[] = {
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#define DVB_S2_GSE_CRC32_LEN 4
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/* Data that is associated with one BBFrame, used by GSE or TS packets
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* contained within it. Lifetime of the packet.
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*/
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typedef struct {
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address src;
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address dst;
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port_type ptype;
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guint32 srcport;
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guint32 destport;
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guint8 isi;
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} dvbs2_bb_data;
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/* GSE defragmentation related data, one set of data per conversation.
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* Two tables are used. One is for the first pass, and contains the most
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* recent information for each Frag ID for that conversation. The other is
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* for later random access, indexed by both packet number and Frag ID.
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* (It seems very unlikely according to the spec that the same Frag ID would
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* be reused on the same BBFrame that it was completed. If that does happen,
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* then we would have to index by something else, say, subpacket number in the
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* BBFrame (which we would have to track ourselves.)
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*/
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typedef struct {
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wmem_tree_t *fragid_table;
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wmem_tree_t *subpacket_table;
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} gse_analysis_data;
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typedef struct {
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guint8 labeltype;
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} gse_frag_data;
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static gse_analysis_data *
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init_gse_analysis_data(void)
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{
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gse_analysis_data *gse_data;
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gse_data = wmem_new0(wmem_file_scope(), gse_analysis_data);
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gse_data->fragid_table = wmem_tree_new(wmem_file_scope());
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gse_data->subpacket_table = wmem_tree_new(wmem_file_scope());
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return gse_data;
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}
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static gse_analysis_data *
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get_gse_analysis_data(conversation_t *conv)
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{
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gse_analysis_data *gse_data;
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gse_data = (gse_analysis_data *)conversation_get_proto_data(conv, proto_dvb_s2_gse);
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if (!gse_data) {
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gse_data = init_gse_analysis_data();
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conversation_add_proto_data(conv, proto_dvb_s2_gse, gse_data);
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}
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return gse_data;
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}
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static gse_frag_data *
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get_gse_frag_data(gse_analysis_data *dvbs2_data, guint32 fragid, gboolean create)
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{
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gse_frag_data *frag_data;
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frag_data = (gse_frag_data *)wmem_tree_lookup32(dvbs2_data->fragid_table, fragid);
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if (!frag_data && create) {
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frag_data = wmem_new0(wmem_file_scope(), gse_frag_data);
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wmem_tree_insert32(dvbs2_data->fragid_table, fragid, (void *)frag_data);
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}
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return frag_data;
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}
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static gse_frag_data *
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get_gse_subpacket_data(gse_analysis_data *dvbs2_data, guint32 num, guint32 fragid, gboolean create)
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{
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gse_frag_data *subpacket_data;
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wmem_tree_key_t subpacket_key[3];
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subpacket_key[0].length = 1;
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subpacket_key[0].key = #
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subpacket_key[1].length = 1;
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subpacket_key[1].key = &fragid;
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subpacket_key[2].length = 0;
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subpacket_key[2].key = NULL;
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subpacket_data = (gse_frag_data *)wmem_tree_lookup32_array(dvbs2_data->subpacket_table, subpacket_key);
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if (!subpacket_data && create) {
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subpacket_data = wmem_new0(wmem_file_scope(), gse_frag_data);
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wmem_tree_insert32_array(dvbs2_data->subpacket_table, subpacket_key, (void *)subpacket_data);
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}
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return subpacket_data;
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}
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/* *** helper functions *** */
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static guint8 compute_crc8(tvbuff_t *p, guint8 len, guint8 offset)
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{
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@ -908,11 +1005,12 @@ static guint8 compute_crc8(tvbuff_t *p, guint8 len, guint8 offset)
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}
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/* *** Code to actually dissect the packets *** */
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static int dissect_dvb_s2_gse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
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static int dissect_dvb_s2_gse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
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{
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int new_off = 0;
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int frag_len;
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guint16 gse_hdr, data_len, padding_len, gse_proto = 0;
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guint8 labeltype, isi = 0;
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guint16 gse_hdr, data_len, packet_len, gse_proto = 0;
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guint32 fragid, totlength, crc32_calc = 0;
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proto_item *ti;
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proto_item *ttf;
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@ -921,6 +1019,15 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tre
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tvbuff_t *next_tvb, *data_tvb;
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gboolean dissected = FALSE;
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gboolean update_col_info = TRUE;
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gboolean complete = FALSE;
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dvbs2_bb_data *pdata;
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conversation_t *conv;
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gse_analysis_data *gse_data;
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address save_src, save_dst;
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port_type save_ptype;
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guint32 save_srcport, save_destport;
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static int * const gse_header_bitfields[] = {
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&hf_dvb_s2_gse_hdr_start,
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@ -934,189 +1041,258 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tre
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/* get the GSE header */
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gse_hdr = tvb_get_ntohs(tvb, DVB_S2_GSE_OFFS_HDR);
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labeltype = (gse_hdr & DVB_S2_GSE_HDR_LABELTYPE_MASK) >> DVB_S2_GSE_HDR_LABELTYPE_SHIFT;
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/* check if this is just padding, which takes up the rest of the frame */
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if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_START_POS) &&
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BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS) &&
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BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS1) && BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS2)) {
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labeltype == 0) {
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padding_len = tvb_reported_length(tvb);
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proto_tree_add_uint_format(tree, hf_dvb_s2_gse_padding, tvb, new_off, padding_len, padding_len,
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"DVB-S2 GSE Padding, Length: %d", padding_len);
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packet_len = tvb_reported_length(tvb);
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proto_tree_add_uint_format(tree, hf_dvb_s2_gse_padding, tvb, new_off, packet_len, packet_len,
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"DVB-S2 GSE Padding, Length: %d", packet_len);
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col_append_str(pinfo->cinfo, COL_INFO, " pad");
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new_off += padding_len;
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return new_off;
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} else {
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/* Not padding, parse as a GSE Header */
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new_off += 2;
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frag_len = (gse_hdr & DVB_S2_GSE_HDR_LENGTH_MASK)+2;
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ti = proto_tree_add_item(tree, proto_dvb_s2_gse, tvb, 0, frag_len, ENC_NA);
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copy_address_shallow(&save_src, &pinfo->src);
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copy_address_shallow(&save_dst, &pinfo->dst);
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save_ptype = pinfo->ptype;
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save_srcport = pinfo->srcport;
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save_destport = pinfo->destport;
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if (data) { // Called from the BBFrame dissector
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pdata = (dvbs2_bb_data *)data;
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isi = pdata->isi;
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copy_address_shallow(&pinfo->src, &pdata->src);
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copy_address_shallow(&pinfo->dst, &pdata->dst);
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pinfo->ptype = pdata->ptype;
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pinfo->srcport = pdata->srcport;
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pinfo->destport = pdata->destport;
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}
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conv = find_or_create_conversation(pinfo);
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gse_data = get_gse_analysis_data(conv);
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/* Length in header does not include header itself */
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packet_len = (gse_hdr & DVB_S2_GSE_HDR_LENGTH_MASK) + 2;
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ti = proto_tree_add_item(tree, proto_dvb_s2_gse, tvb, 0, packet_len, ENC_NA);
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dvb_s2_gse_tree = proto_item_add_subtree(ti, ett_dvb_s2_gse);
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proto_tree_add_bitmask_with_flags(dvb_s2_gse_tree, tvb, DVB_S2_GSE_OFFS_HDR, hf_dvb_s2_gse_hdr,
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new_off += 2;
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ti = proto_tree_add_bitmask_with_flags(dvb_s2_gse_tree, tvb, DVB_S2_GSE_OFFS_HDR, hf_dvb_s2_gse_hdr,
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ett_dvb_s2_gse_hdr, gse_header_bitfields, ENC_BIG_ENDIAN, BMT_NO_TFS);
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if (packet_len > tvb_reported_length(tvb)) {
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expert_add_info(pinfo, ti, &ei_dvb_s2_gse_length_invalid);
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packet_len = tvb_reported_length(tvb);
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}
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/* Get the fragment ID for reassembly */
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guint8 fragid = tvb_get_guint8(tvb, new_off);
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/* If not both a start and an end packet, then it's a fragment */
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if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_START_POS) || BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
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/* Not a start or end packet, add only the fragid */
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proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_fragid, tvb, new_off, 1, ENC_BIG_ENDIAN);
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new_off += 1;
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}
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if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS) && BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
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/* Start packet, add the fragment size */
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proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_totlength, tvb, new_off, 2, ENC_BIG_ENDIAN);
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proto_tree_add_item_ret_uint(dvb_s2_gse_tree, hf_dvb_s2_gse_fragid, tvb, new_off, 1, ENC_BIG_ENDIAN, &fragid);
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col_append_str(pinfo->cinfo, COL_INFO, "(frag) ");
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/* Differentiate between the same frag id on different ISI */
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fragid ^= (isi << 8);
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new_off += 1;
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new_off += 2;
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gse_frag_data *subpacket_data = NULL;
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if (!PINFO_FD_VISITED(pinfo)) {
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gse_frag_data *frag_data;
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if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS)) {
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frag_data = get_gse_frag_data(gse_data, fragid, TRUE);
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frag_data->labeltype = labeltype;
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/* Delete any previous in-progress reassembly if
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* we get a new start packet. */
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data_tvb = fragment_delete(&dvbs2_reassembly_table,
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pinfo, fragid, NULL);
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/* Since we use fragment_add_seq_next, which (as part of
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* the fragment_*_check family) moves completed assemblies
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* to a new table (and only checks the completed table
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* after a packet is visited once), this will never return
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* non-NULL nor cause problems later.
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* If it does, something changed in the API.
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*/
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if (data_tvb != NULL) {
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DISSECTOR_ASSERT_NOT_REACHED();
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}
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subpacket_data = get_gse_subpacket_data(gse_data, pinfo->num, fragid, TRUE);
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subpacket_data->labeltype = frag_data->labeltype;
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} else {
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frag_data = get_gse_frag_data(gse_data, fragid, FALSE);
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/* ETSI TS 102 601-1 A.2 Reassembly
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* Discard the packet if no buffer is in the re-assembly
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* state for the Frag ID (check with fragment_get).
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*/
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if (frag_data && fragment_get(&dvbs2_reassembly_table, pinfo, fragid, NULL)) {
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subpacket_data = get_gse_subpacket_data(gse_data, pinfo->num, fragid, TRUE);
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subpacket_data->labeltype = frag_data->labeltype;
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}
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}
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} else {
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subpacket_data = get_gse_subpacket_data(gse_data, pinfo->num, fragid, FALSE);
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}
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fragment_head *dvbs2_frag_head = NULL;
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if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
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data_len = packet_len - new_off - DVB_S2_GSE_CRC32_LEN;
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} else {
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data_len = packet_len - new_off;
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}
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if (subpacket_data) {
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dvbs2_frag_head = fragment_add_seq_next(&dvbs2_reassembly_table, tvb, new_off,
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pinfo, fragid, NULL, data_len, BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS));
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}
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next_tvb = process_reassembled_data(tvb, new_off, pinfo, "Reassembled DVB-S2",
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dvbs2_frag_head, &dvbs2_frag_items, &update_col_info, tree);
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if (next_tvb != NULL) {
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/* We have a reassembled packet. */
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complete = TRUE;
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labeltype = subpacket_data->labeltype;
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crc32_calc = crc32_mpeg2_tvb_offset(next_tvb, 0, tvb_reported_length(next_tvb));
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new_off = 0;
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ti = proto_tree_add_item_ret_uint(dvb_s2_gse_tree, hf_dvb_s2_gse_totlength, next_tvb, new_off, 2, ENC_BIG_ENDIAN, &totlength);
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new_off += 2;
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/* Value of totlength field does not include itself or the
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* CRC32.
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*/
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if (totlength != (guint32)tvb_reported_length_remaining(next_tvb, new_off)) {
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expert_add_info(pinfo, ti, &ei_dvb_s2_gse_totlength_invalid);
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}
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} else {
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next_tvb = tvb_new_subset_length(tvb, new_off, data_len);
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new_off = 0;
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if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS)) {
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/* Start packet, add the total length */
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proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_totlength, next_tvb, new_off, 2, ENC_BIG_ENDIAN);
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new_off += 2;
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}
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}
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} else {
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complete = TRUE;
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next_tvb = tvb_new_subset_length(tvb, 0, packet_len);
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}
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if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS)) {
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if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS) || complete) {
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/* Start packet, decode the header */
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gse_proto = tvb_get_ntohs(tvb, new_off);
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gse_proto = tvb_get_ntohs(next_tvb, new_off);
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/* Protocol Type */
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if (gse_proto <= 1535) {
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/* Type 1 (Next-Header Type field) */
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proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_next_header, tvb, new_off, 2, ENC_BIG_ENDIAN);
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proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_next_header, next_tvb, new_off, 2, ENC_BIG_ENDIAN);
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}
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else {
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/* Type 2 (EtherType compatible Type Fields) */
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proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_ethertype, tvb, new_off, 2, ENC_BIG_ENDIAN);
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_ethertype, next_tvb, new_off, 2, ENC_BIG_ENDIAN);
|
||||
}
|
||||
new_off += 2;
|
||||
|
||||
if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS1) && BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS2)) {
|
||||
/* 6 byte label */
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS))
|
||||
col_append_str(pinfo->cinfo, COL_INFO, "6 ");
|
||||
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_label6, tvb, new_off, 6, ENC_NA);
|
||||
|
||||
new_off += 6;
|
||||
} else if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS1) &&
|
||||
BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS2)) {
|
||||
/* 3 byte label */
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS))
|
||||
col_append_str(pinfo->cinfo, COL_INFO, "3 ");
|
||||
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_label3, tvb, new_off, 3, ENC_BIG_ENDIAN);
|
||||
|
||||
new_off += 3;
|
||||
} else {
|
||||
/* 0 byte label */
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS))
|
||||
col_append_str(pinfo->cinfo, COL_INFO, "0 ");
|
||||
switch (labeltype) {
|
||||
case 0:
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS))
|
||||
col_append_str(pinfo->cinfo, COL_INFO, "6 ");
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_label6, next_tvb, new_off, 6, ENC_NA);
|
||||
new_off += 6;
|
||||
break;
|
||||
case 1:
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS))
|
||||
col_append_str(pinfo->cinfo, COL_INFO, "3 ");
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_label3, next_tvb, new_off, 3, ENC_BIG_ENDIAN);
|
||||
new_off += 3;
|
||||
break;
|
||||
case 2:
|
||||
case 3:
|
||||
/* TODO: Case 3 means "same as previous in the BBF."
|
||||
* We can treat it as no label length because nothing
|
||||
* is in the packet.
|
||||
* In the future we could save the values in packet data
|
||||
* and include them here as generated values. Then we
|
||||
* could also set expert_info if no previous packet in
|
||||
* the BBF had a label, or if the previous label was
|
||||
* zero length, both illegal according to ETSI TS
|
||||
* 102 606-1 A.1 "Filtering".
|
||||
*/
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS))
|
||||
col_append_str(pinfo->cinfo, COL_INFO, "0 ");
|
||||
break;
|
||||
}
|
||||
if (gse_proto < 0x0600 && gse_proto >= 0x100) {
|
||||
/* Only display optional extension headers */
|
||||
/* TODO: needs to be tested */
|
||||
|
||||
/* TODO: implementation needs to be checked (len of ext-header??) */
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_exthdr, tvb, new_off, 1, ENC_BIG_ENDIAN);
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_exthdr, next_tvb, new_off, 1, ENC_BIG_ENDIAN);
|
||||
|
||||
new_off += 1;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/* correct cinfo */
|
||||
col_append_str(pinfo->cinfo, COL_INFO, "(frag) ");
|
||||
}
|
||||
|
||||
next_tvb = tvb_new_subset_remaining(tvb, new_off);
|
||||
data_tvb = tvb_new_subset_remaining(next_tvb, new_off);
|
||||
|
||||
if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_START_POS) && BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
|
||||
data_len = (gse_hdr & DVB_S2_GSE_HDR_LENGTH_MASK) - (new_off - DVB_S2_GSE_MINSIZE) - DVB_S2_GSE_CRC32_LEN;
|
||||
} else {
|
||||
data_len = (gse_hdr & DVB_S2_GSE_HDR_LENGTH_MASK) - (new_off - DVB_S2_GSE_MINSIZE);
|
||||
}
|
||||
copy_address_shallow(&pinfo->src, &save_src);
|
||||
copy_address_shallow(&pinfo->dst, &save_dst);
|
||||
pinfo->ptype = save_ptype;
|
||||
pinfo->srcport = save_srcport;
|
||||
pinfo->destport = save_destport;
|
||||
|
||||
data_tvb = NULL;
|
||||
if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_START_POS) || BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
|
||||
fragment_head *dvbs2_frag_head = NULL;
|
||||
int offset = new_off;
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS)) {
|
||||
offset -= 2; /* re-include GSE type in reassembled data */
|
||||
data_len += 2;
|
||||
if (complete) {
|
||||
switch (gse_proto) {
|
||||
case ETHERTYPE_IP:
|
||||
if (dvb_s2_full_dissection)
|
||||
{
|
||||
call_dissector(ip_handle, data_tvb, pinfo, tree);
|
||||
dissected = TRUE;
|
||||
}
|
||||
break;
|
||||
|
||||
case ETHERTYPE_IPv6:
|
||||
if (dvb_s2_full_dissection)
|
||||
{
|
||||
call_dissector(ipv6_handle, data_tvb, pinfo, tree);
|
||||
dissected = TRUE;
|
||||
}
|
||||
break;
|
||||
|
||||
case ETHERTYPE_VLAN:
|
||||
if (dvb_s2_full_dissection)
|
||||
{
|
||||
call_dissector(eth_withoutfcs_handle, data_tvb, pinfo, tree);
|
||||
dissected = TRUE;
|
||||
}
|
||||
break;
|
||||
|
||||
case DVB_RCS2_SIGNAL_TABLE:
|
||||
call_dissector(dvb_s2_table_handle, data_tvb, pinfo, tree);
|
||||
dissected = TRUE;
|
||||
break;
|
||||
|
||||
case DVB_RCS2_NCR:
|
||||
ttf = proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_ncr, data_tvb, 0, -1, ENC_NA);
|
||||
dvb_s2_gse_ncr_tree = proto_item_add_subtree(ttf, ett_dvb_s2_gse_ncr);
|
||||
proto_tree_add_item(dvb_s2_gse_ncr_tree, hf_dvb_s2_gse_data, data_tvb, 0, -1, ENC_NA);
|
||||
dissected = TRUE;
|
||||
break;
|
||||
|
||||
default:
|
||||
/* Not handled! TODO: expert info? */
|
||||
break;
|
||||
}
|
||||
dvbs2_frag_head = fragment_add_seq_next(&dvbs2_reassembly_table, tvb, offset,
|
||||
pinfo, fragid, NULL, data_len, BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS));
|
||||
|
||||
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS))
|
||||
dvbs2_frag_head = fragment_end_seq_next(&dvbs2_reassembly_table, pinfo, fragid, NULL);
|
||||
|
||||
data_tvb = process_reassembled_data(tvb, new_off, pinfo, "Reassembled DVB-S2",
|
||||
dvbs2_frag_head, &dvbs2_frag_items, &update_col_info, tree);
|
||||
}
|
||||
|
||||
if (data_tvb != NULL) {
|
||||
/* We have a reassembled packet. Extract the gse_proto from it. */
|
||||
gse_proto = tvb_get_ntohs(data_tvb, 0);
|
||||
/* And then remove it from the reassembled data */
|
||||
data_tvb = tvb_new_subset_remaining(data_tvb, 2);
|
||||
} else {
|
||||
data_tvb = tvb_new_subset_length(tvb, new_off, data_len);
|
||||
}
|
||||
|
||||
switch (gse_proto) {
|
||||
case ETHERTYPE_IP:
|
||||
if (dvb_s2_full_dissection)
|
||||
{
|
||||
new_off += call_dissector(ip_handle, next_tvb, pinfo, tree);
|
||||
dissected = TRUE;
|
||||
}
|
||||
break;
|
||||
|
||||
case ETHERTYPE_IPv6:
|
||||
if (dvb_s2_full_dissection)
|
||||
{
|
||||
new_off += call_dissector(ipv6_handle, next_tvb, pinfo, tree);
|
||||
dissected = TRUE;
|
||||
}
|
||||
break;
|
||||
|
||||
case ETHERTYPE_VLAN:
|
||||
if (dvb_s2_full_dissection)
|
||||
{
|
||||
new_off += call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree);
|
||||
dissected = TRUE;
|
||||
}
|
||||
break;
|
||||
|
||||
case DVB_RCS2_SIGNAL_TABLE:
|
||||
call_dissector(dvb_s2_table_handle, data_tvb, pinfo, tree);
|
||||
new_off += data_len;
|
||||
dissected = TRUE;
|
||||
break;
|
||||
|
||||
case DVB_RCS2_NCR:
|
||||
ttf = proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_ncr, tvb, new_off, data_len, ENC_NA);
|
||||
dvb_s2_gse_ncr_tree = proto_item_add_subtree(ttf, ett_dvb_s2_gse_ncr);
|
||||
proto_tree_add_item(dvb_s2_gse_ncr_tree, hf_dvb_s2_gse_data, tvb, new_off, data_len, ENC_NA);
|
||||
new_off += data_len;
|
||||
dissected = TRUE;
|
||||
break;
|
||||
|
||||
default:
|
||||
/* Not handled! TODO: expert info? */
|
||||
break;
|
||||
}
|
||||
|
||||
if (!dissected) {
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_data, tvb, new_off, data_len, ENC_NA);
|
||||
new_off += data_len;
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_data, data_tvb, 0, -1, ENC_NA);
|
||||
}
|
||||
|
||||
/* add crc32 if last fragment */
|
||||
if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_START_POS) && BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
|
||||
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_crc32, tvb, new_off, DVB_S2_GSE_CRC32_LEN, ENC_BIG_ENDIAN);
|
||||
new_off += DVB_S2_GSE_CRC32_LEN;
|
||||
guint flags = PROTO_CHECKSUM_NO_FLAGS;
|
||||
if (complete) {
|
||||
flags = PROTO_CHECKSUM_VERIFY;
|
||||
}
|
||||
proto_tree_add_checksum(dvb_s2_gse_tree, tvb, packet_len - DVB_S2_GSE_CRC32_LEN, hf_dvb_s2_gse_crc32, hf_dvb_s2_gse_crc32_status, &ei_dvb_s2_gse_crc32, pinfo, crc32_calc, ENC_BIG_ENDIAN, flags);
|
||||
}
|
||||
}
|
||||
|
||||
return new_off;
|
||||
return packet_len;
|
||||
}
|
||||
|
||||
static gboolean test_dvb_s2_crc(tvbuff_t *tvb, guint offset) {
|
||||
|
|
@ -1143,7 +1319,9 @@ static int dissect_dvb_s2_bb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
|
|||
proto_item *ti;
|
||||
proto_tree *dvb_s2_bb_tree;
|
||||
|
||||
guint8 input8, matype1;
|
||||
dvbs2_bb_data* pdata;
|
||||
|
||||
guint8 input8, matype1, isi = 0;
|
||||
guint8 sync_flag = 0;
|
||||
guint16 input16, bb_data_len = 0, user_packet_length;
|
||||
|
||||
|
|
@ -1197,6 +1375,7 @@ static int dissect_dvb_s2_bb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
|
|||
proto_tree_add_uint_format_value(dvb_s2_bb_tree, hf_dvb_s2_bb_matype2, tvb,
|
||||
DVB_S2_BB_OFFS_MATYPE2, 1, input8, "Input Stream Identifier (ISI): %d",
|
||||
input8);
|
||||
isi = input8;
|
||||
} else {
|
||||
proto_tree_add_uint_format_value(dvb_s2_bb_tree, hf_dvb_s2_bb_matype2, tvb,
|
||||
DVB_S2_BB_OFFS_MATYPE2, 1, input8, "reserved");
|
||||
|
|
@ -1227,6 +1406,34 @@ static int dissect_dvb_s2_bb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
|
|||
proto_tree_add_checksum(dvb_s2_bb_tree, tvb, DVB_S2_BB_OFFS_CRC, hf_dvb_s2_bb_crc, hf_dvb_s2_bb_crc_status, &ei_dvb_s2_bb_crc, pinfo,
|
||||
compute_crc8(tvb, DVB_S2_BB_HEADER_LEN - 1, 0), ENC_NA, PROTO_CHECKSUM_VERIFY);
|
||||
|
||||
/* The Base-Band Frame can have multiple GSE (or TS, which can have ULE
|
||||
* or MPE) packets that are concatenated, can be fragmented, and can call
|
||||
* subdissectors including IP (which itself can be fragmented) that
|
||||
* overwrite the pinfo addresses & ports, which are used as keys for
|
||||
* reassembly tables, conversations, and other purposes.
|
||||
*
|
||||
* Thus, we need to save the current values before any subdissectors
|
||||
* are run, and restore them each time before each subpacket. Using
|
||||
* conversation_create_endpoint() could cause problems when subdissectors
|
||||
* try call find_or_create_conversation(). We will also keep track of
|
||||
* the subpacket number, which will be useful in storing persistant
|
||||
* data (the packets themselves do not contain a number.)
|
||||
*
|
||||
* In cases where the BBFrame is the link-layer of the capture we
|
||||
* would use the ISI as our endpoint, but when it is carried over
|
||||
* UDP or RTP we can't necessarily rely on that - a capture might include
|
||||
* different streams sent as single input streams or with the same ISI
|
||||
* over different UDP endpoints and we don't want to mix data when
|
||||
* defragmenting.
|
||||
*/
|
||||
pdata = wmem_new0(wmem_packet_scope(), dvbs2_bb_data);
|
||||
copy_address_shallow(&pdata->src, &pinfo->src);
|
||||
copy_address_shallow(&pdata->dst, &pinfo->dst);
|
||||
pdata->ptype = pinfo->ptype;
|
||||
pdata->srcport = pinfo->srcport;
|
||||
pdata->destport = pinfo->destport;
|
||||
pdata->isi = isi;
|
||||
|
||||
switch (matype1 & DVB_S2_BB_TSGS_MASK) {
|
||||
case DVB_S2_BB_TSGS_GENERIC_CONTINUOUS:
|
||||
/* Check GSE constraints on the BB header per 9.2.1 of ETSI TS 102 771 */
|
||||
|
|
@ -1250,7 +1457,7 @@ static int dissect_dvb_s2_bb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
|
|||
new_off += DVB_S2_BB_EIP_CRC32_LEN;
|
||||
} else {
|
||||
/* start DVB-GSE dissector */
|
||||
sub_dissected = dissect_dvb_s2_gse(tvb_new_subset_length(tvb, new_off, bb_data_len), pinfo, tree, NULL);
|
||||
sub_dissected = dissect_dvb_s2_gse(tvb_new_subset_length(tvb, new_off, bb_data_len), pinfo, tree, pdata);
|
||||
new_off += sub_dissected;
|
||||
|
||||
if ((sub_dissected <= bb_data_len) && (sub_dissected >= DVB_S2_GSE_MINSIZE)) {
|
||||
|
|
@ -1662,6 +1869,12 @@ void proto_register_dvb_s2_modeadapt(void)
|
|||
FT_UINT32, BASE_HEX, NULL, 0x0,
|
||||
"CRC-32", HFILL}
|
||||
},
|
||||
{&hf_dvb_s2_gse_crc32_status, {
|
||||
"CRC Status", "dvb-s2_gse.crc.status",
|
||||
FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0,
|
||||
NULL, HFILL}
|
||||
},
|
||||
|
||||
{ &hf_dvbs2_fragment_overlap,
|
||||
{ "Fragment overlap", "dvb-s2_gse.fragment.overlap", FT_BOOLEAN, BASE_NONE,
|
||||
NULL, 0x0, "Fragment overlaps with other fragments", HFILL }},
|
||||
|
|
@ -1729,6 +1942,14 @@ void proto_register_dvb_s2_modeadapt(void)
|
|||
|
||||
expert_module_t* expert_dvb_s2_bb;
|
||||
|
||||
static ei_register_info ei_gse[] = {
|
||||
{ &ei_dvb_s2_gse_length_invalid, {"dvb-s2_gse.hdr.length_invalid", PI_PROTOCOL, PI_ERROR, "Length field in header exceeds available bytes in frame", EXPFILL }},
|
||||
{ &ei_dvb_s2_gse_totlength_invalid, {"dvb-s2_gse.totlength_invalid", PI_REASSEMBLE, PI_ERROR, "Length of reassembled packet does not equal total length field (missing fragments?)", EXPFILL }},
|
||||
{ &ei_dvb_s2_gse_crc32, { "dvb-s2_gse.bad_checksum", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
|
||||
};
|
||||
|
||||
expert_module_t* expert_dvb_s2_gse;
|
||||
|
||||
proto_dvb_s2_modeadapt = proto_register_protocol("DVB-S2 Mode Adaptation Header", "DVB-S2", "dvb-s2_modeadapt");
|
||||
|
||||
proto_dvb_s2_bb = proto_register_protocol("DVB-S2 Baseband Frame", "DVB-S2-BB", "dvb-s2_bb");
|
||||
|
|
@ -1745,6 +1966,8 @@ void proto_register_dvb_s2_modeadapt(void)
|
|||
|
||||
proto_register_field_array(proto_dvb_s2_gse, hf_gse, array_length(hf_gse));
|
||||
proto_register_subtree_array(ett_gse, array_length(ett_gse));
|
||||
expert_dvb_s2_gse = expert_register_protocol(proto_dvb_s2_gse);
|
||||
expert_register_field_array(expert_dvb_s2_gse, ei_gse, array_length(ei_gse));
|
||||
|
||||
dvb_s2_modeadapt_module = prefs_register_protocol(proto_dvb_s2_modeadapt, proto_reg_handoff_dvb_s2_modeadapt);
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue