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DVB-S2-BB: Make dissect_dvb_s2_gse() have the dissector_t signature 

Change dissect_dvb_s2_bb to take a tvb_subset of the appropriate size
and offset instead of being passed in an offset and length. Rearrange the
parameters so that it has the dissector_t signature. This is a little
cleaner, and also allows in the future creating dissector handles that
call the GSE dissector directly for GSE frames not carried within a
BBFrame.
This commit is contained in:
John Thacker 2021-05-23 08:05:27 -04:00 committed by Wireshark GitLab Utility
parent 479c8a29eb
commit 6b2dd3561e
1 changed files with 24 additions and 24 deletions
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48
epan/dissectors/packet-dvb-s2-bb.c
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@ -908,7 +908,7 @@ static guint8 compute_crc8(tvbuff_t *p, guint8 len, guint8 offset)
}
/* *** Code to actually dissect the packets *** */
static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, packet_info *pinfo, int bytes_available)
static int dissect_dvb_s2_gse(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
int new_off = 0;
int frag_len;
@ -933,15 +933,15 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
col_append_str(pinfo->cinfo, COL_INFO, " GSE");
/* get the GSE header */
gse_hdr = tvb_get_ntohs(tvb, cur_off + DVB_S2_GSE_OFFS_HDR);
gse_hdr = tvb_get_ntohs(tvb, DVB_S2_GSE_OFFS_HDR);
/* check if this is just padding, which takes up the rest of the frame */
if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_START_POS) &&
BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS) &&
BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS1) && BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_LABELTYPE_POS2)) {
padding_len = bytes_available;
proto_tree_add_uint_format(tree, hf_dvb_s2_gse_padding, tvb, cur_off + new_off, padding_len, padding_len,
padding_len = tvb_reported_length(tvb);
proto_tree_add_uint_format(tree, hf_dvb_s2_gse_padding, tvb, new_off, padding_len, padding_len,
"DVB-S2 GSE Padding, Length: %d", padding_len);
col_append_str(pinfo->cinfo, COL_INFO, " pad");
new_off += padding_len;
@ -951,39 +951,39 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
/* Not padding, parse as a GSE Header */
new_off += 2;
frag_len = (gse_hdr & DVB_S2_GSE_HDR_LENGTH_MASK)+2;
ti = proto_tree_add_item(tree, proto_dvb_s2_gse, tvb, cur_off, frag_len, ENC_NA);
ti = proto_tree_add_item(tree, proto_dvb_s2_gse, tvb, 0, frag_len, ENC_NA);
dvb_s2_gse_tree = proto_item_add_subtree(ti, ett_dvb_s2_gse);
proto_tree_add_bitmask_with_flags(dvb_s2_gse_tree, tvb, cur_off + DVB_S2_GSE_OFFS_HDR, hf_dvb_s2_gse_hdr,
proto_tree_add_bitmask_with_flags(dvb_s2_gse_tree, tvb, DVB_S2_GSE_OFFS_HDR, hf_dvb_s2_gse_hdr,
ett_dvb_s2_gse_hdr, gse_header_bitfields, ENC_BIG_ENDIAN, BMT_NO_TFS);
/* Get the fragment ID for reassembly */
guint8 fragid = tvb_get_guint8(tvb, cur_off + new_off);
guint8 fragid = tvb_get_guint8(tvb, new_off);
if (BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_START_POS) || BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
/* Not a start or end packet, add only the fragid */
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_fragid, tvb, cur_off + new_off, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_fragid, tvb, new_off, 1, ENC_BIG_ENDIAN);
new_off += 1;
}
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS) && BIT_IS_CLEAR(gse_hdr, DVB_S2_GSE_HDR_STOP_POS)) {
/* Start packet, add the fragment size */
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_totlength, tvb, cur_off + new_off, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_totlength, tvb, new_off, 2, ENC_BIG_ENDIAN);
col_append_str(pinfo->cinfo, COL_INFO, "(frag) ");
new_off += 2;
}
if (BIT_IS_SET(gse_hdr, DVB_S2_GSE_HDR_START_POS)) {
/* Start packet, decode the header */
gse_proto = tvb_get_ntohs(tvb, cur_off + new_off);
gse_proto = tvb_get_ntohs(tvb, new_off);
/* Protocol Type */
if (gse_proto <= 1535) {
/* Type 1 (Next-Header Type field) */
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_next_header, tvb, cur_off + new_off, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_next_header, tvb, new_off, 2, ENC_BIG_ENDIAN);
}
else {
/* Type 2 (EtherType compatible Type Fields) */
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_ethertype, tvb, cur_off + new_off, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_proto_ethertype, tvb, new_off, 2, ENC_BIG_ENDIAN);
}
new_off += 2;
@ -992,7 +992,7 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
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, cur_off + new_off, 6, ENC_NA);
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) &&
@ -1001,7 +1001,7 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
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, cur_off + new_off, 3, ENC_BIG_ENDIAN);
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_label3, tvb, new_off, 3, ENC_BIG_ENDIAN);
new_off += 3;
} else {
@ -1014,7 +1014,7 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
/* 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, cur_off + new_off, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_exthdr, tvb, new_off, 1, ENC_BIG_ENDIAN);
new_off += 1;
}
@ -1025,7 +1025,7 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
col_append_str(pinfo->cinfo, COL_INFO, "(frag) ");
}
next_tvb = tvb_new_subset_remaining(tvb, cur_off + new_off);
next_tvb = tvb_new_subset_remaining(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;
@ -1036,7 +1036,7 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
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 = cur_off + new_off;
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;
@ -1047,7 +1047,7 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
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, cur_off + new_off, pinfo, "Reassembled DVB-S2",
data_tvb = process_reassembled_data(tvb, new_off, pinfo, "Reassembled DVB-S2",
dvbs2_frag_head, &dvbs2_frag_items, &update_col_info, tree);
}
@ -1057,7 +1057,7 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
/* 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, cur_off + new_off, data_len);
data_tvb = tvb_new_subset_length(tvb, new_off, data_len);
}
switch (gse_proto) {
@ -1092,9 +1092,9 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
break;
case DVB_RCS2_NCR:
ttf = proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_ncr, tvb, cur_off + new_off, data_len, ENC_NA);
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, cur_off + new_off, data_len, ENC_NA);
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;
@ -1105,13 +1105,13 @@ static int dissect_dvb_s2_gse(tvbuff_t *tvb, int cur_off, proto_tree *tree, pack
}
if (!dissected) {
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_data, tvb, cur_off + new_off, data_len, ENC_NA);
proto_tree_add_item(dvb_s2_gse_tree, hf_dvb_s2_gse_data, tvb, new_off, data_len, ENC_NA);
new_off += data_len;
}
/* 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, cur_off + new_off, DVB_S2_GSE_CRC32_LEN, ENC_BIG_ENDIAN);
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;
}
}
@ -1250,7 +1250,7 @@ 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_off, tree, pinfo, bb_data_len);
sub_dissected = dissect_dvb_s2_gse(tvb_new_subset_length(tvb, new_off, bb_data_len), pinfo, tree, NULL);
new_off += sub_dissected;
if ((sub_dissected <= bb_data_len) && (sub_dissected >= DVB_S2_GSE_MINSIZE)) {