From 40312bf2ebc30d943e1c1372877279d091462de9 Mon Sep 17 00:00:00 2001 From: Martin Kaiser Date: Wed, 23 Dec 2015 18:42:42 +0100 Subject: [mp2t] add an expert info for invalid adaptation_field_control values use it for docsis and for null packets do some other minor cleanup while at it Change-Id: I605f0a9291aa7715d1fe68449c39a2e18e03fa18 Reviewed-on: https://code.wireshark.org/review/12853 Reviewed-by: Martin Kaiser --- epan/dissectors/packet-mp2t.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) (limited to 'epan') diff --git a/epan/dissectors/packet-mp2t.c b/epan/dissectors/packet-mp2t.c index 54da8442ad..49eac8d80e 100644 --- a/epan/dissectors/packet-mp2t.c +++ b/epan/dissectors/packet-mp2t.c @@ -229,6 +229,7 @@ static int hf_msg_ts_packet_reassembled = -1; static expert_field ei_mp2t_pointer = EI_INIT; static expert_field ei_mp2t_cc_drop = EI_INIT; +static expert_field ei_mp2t_invalid_afc = EI_INIT; static const fragment_items mp2t_msg_frag_items = { /* Fragment subtrees */ @@ -1114,11 +1115,12 @@ dissect_tsp(tvbuff_t *tvb, gint offset, packet_info *pinfo, mp2t_tree = proto_item_add_subtree( ti, ett_mp2t ); header = tvb_get_ntohl(tvb, offset); - + pusi_flag = (header & 0x00400000); pid = (header & MP2T_PID_MASK) >> MP2T_PID_SHIFT; - cc = (header & MP2T_CC_MASK) >> MP2T_CC_SHIFT; tsc = (header & MP2T_TSC_MASK); - pusi_flag = (header & 0x00400000); + afc = (header & MP2T_AFC_MASK) >> MP2T_AFC_SHIFT; + cc = (header & MP2T_CC_MASK) >> MP2T_CC_SHIFT; + proto_item_append_text(ti, " PID=0x%x CC=%d", pid, cc); col_set_str(pinfo->cinfo, COL_PROTOCOL, "MPEG TS"); @@ -1134,13 +1136,10 @@ dissect_tsp(tvbuff_t *tvb, gint offset, packet_info *pinfo, afci = proto_tree_add_item( mp2t_header_tree, hf_mp2t_afc, tvb, offset, 4, ENC_BIG_ENDIAN); proto_tree_add_item( mp2t_header_tree, hf_mp2t_cc, tvb, offset, 4, ENC_BIG_ENDIAN); - afc = (header & MP2T_AFC_MASK) >> MP2T_AFC_SHIFT; - mp2t_data = get_mp2t_conversation_data(conv); pid_analysis = get_pid_analysis(mp2t_data, pid); - /* Find out the payload type based on the payload */ if (pid_analysis->pload_type == pid_pload_unknown) { if (pid == MP2T_PID_NULL) { pid_analysis->pload_type = pid_pload_null; @@ -1151,12 +1150,19 @@ dissect_tsp(tvbuff_t *tvb, gint offset, packet_info *pinfo, if (pid_analysis->pload_type == pid_pload_docsis && (afc != 1)) { /* DOCSIS packets should not have an adaptation field */ - proto_item_append_text(afci, " (Invalid for DOCSIS packets, should be 1)"); + if (afc != 1) { + expert_add_info_format(pinfo, afci, &ei_mp2t_invalid_afc, + "Adaptation Field Control for DOCSIS packets must be 0x01"); + } } if (pid_analysis->pload_type == pid_pload_null) { - /* Nothing more to do */ col_set_str(pinfo->cinfo, COL_INFO, "NULL packet"); + if (afc != 1) { + expert_add_info_format(pinfo, afci, &ei_mp2t_invalid_afc, + "Adaptation Field Control for NULL packets must be 0x01"); + } + /* Nothing more to do */ return; } @@ -1517,6 +1523,8 @@ proto_register_mp2t(void) static ei_register_info ei[] = { { &ei_mp2t_pointer, { "mp2t.pointer_too_large", PI_MALFORMED, PI_ERROR, "Pointer value is too large", EXPFILL }}, { &ei_mp2t_cc_drop, { "mp2t.cc.drop", PI_MALFORMED, PI_ERROR, "Detected missing TS frames", EXPFILL }}, + { &ei_mp2t_invalid_afc, { "mp2t.afc.invalid", PI_PROTOCOL, PI_WARN, + "Adaptation Field Control contains an invalid value", EXPFILL }} }; expert_module_t* expert_mp2t; -- cgit v1.2.3