diff options
| author | Harald Welte <laforge@osmocom.org> | 2020-08-20 21:45:09 +0200 |
|---|---|---|
| committer | Anders Broman <a.broman58@gmail.com> | 2020-08-21 05:11:34 +0000 |
| commit | e7116cca75937d96d5795340388a519ee8e6f882 (patch) | |
| tree | e4eaae471f3721ae36c8e9ed70983009d63d7eb5 | |
| parent | 217a92981b04de74051b243ac6c8eea32f44b848 (diff) | |
packet-fr: Treat DLCI=0 as Q.933 LMI if GPRS-NS is selected
3GPP TS 48.016 specifies GPRS-NS over Frame Reley. In Section
6.1.1 it explicitly states that ITU-T Q.933 Annex A for FR PVC
must be supported. In real-world Gb-over-FR protocol traces I also
see related LMI messages on DLCI=0.
Hence, let's not dispatch DLCI=0 messages to the GPRS-NS dissector,
where they are all detected wrongly. Only non-zero DLCI are NS-VC.
Change-Id: I6ce3557cda0da31323a851008bf648047ba1f926
Reviewed-on: https://code.wireshark.org/review/38211
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
| -rw-r--r-- | epan/dissectors/packet-fr.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/epan/dissectors/packet-fr.c b/epan/dissectors/packet-fr.c index b4ed470202..6a1768ca45 100644 --- a/epan/dissectors/packet-fr.c +++ b/epan/dissectors/packet-fr.c @@ -680,8 +680,18 @@ dissect_fr_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, break; case GPRS_NS: - next_tvb = tvb_new_subset_remaining(tvb, offset); - call_dissector(gprs_ns_handle, next_tvb, pinfo, tree); + if (addr == 0) { + fr_ctrl = tvb_get_guint8(tvb, offset); + control = dissect_xdlc_control(tvb, offset, pinfo, fr_tree, + hf_fr_control, ett_fr_control, + &fr_cf_items, &fr_cf_items_ext, + NULL, NULL, is_response, TRUE, TRUE); + offset += XDLC_CONTROL_LEN(control, TRUE); + dissect_fr_nlpid(tvb, offset, pinfo, tree, ti, fr_tree, fr_ctrl); + } else { + next_tvb = tvb_new_subset_remaining(tvb, offset); + call_dissector(gprs_ns_handle, next_tvb, pinfo, tree); + } break; case RAW_ETHER: |