diff options
| author | John Thacker <johnthacker@gmail.com> | 2021-10-29 22:34:48 -0400 |
|---|---|---|
| committer | John Thacker <johnthacker@gmail.com> | 2021-10-29 22:38:42 -0400 |
| commit | 278ba4157f0856e7af0b16257a9d53304393ec65 (patch) | |
| tree | da5683c94ab23548e2937b874d6c77c3fa1408fb /epan/dissectors/packet-epl.c | |
| parent | 523c4f643431be6b873720be14ff9de55146afbd (diff) | |
EPL: Reject non-EPL packets at the beginning
If we're going to reject a packet because it's not a valid EPL
packet, do so at the beginning, before setting the column values
and changing the port types and values.
Diffstat (limited to 'epan/dissectors/packet-epl.c')
| -rw-r--r-- | epan/dissectors/packet-epl.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/epan/dissectors/packet-epl.c b/epan/dissectors/packet-epl.c index 6b0cbfc036..66ce1b2a74 100644 --- a/epan/dissectors/packet-epl.c +++ b/epan/dissectors/packet-epl.c @@ -2521,12 +2521,9 @@ dissect_eplpdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean udp if (tvb_reported_length(tvb) < 3) { /* Not enough data for an EPL header; don't try to interpret it */ - return FALSE; + return 0; } - /* Make entries in Protocol column and Info column on summary display */ - col_set_str(pinfo->cinfo, COL_PROTOCOL, udpencap ? "POWERLINK/UDP" : "POWERLINK"); - /* Get message type */ epl_mtyp = tvb_get_guint8(tvb, EPL_MTYP_OFFSET) & 0x7F; @@ -2536,7 +2533,15 @@ dissect_eplpdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean udp * to dissect it as a normal EPL packet. */ if (dissector_try_heuristic(heur_epl_subdissector_list, tvb, pinfo, tree, &hdtbl_entry, &epl_mtyp)) - return TRUE; + return tvb_reported_length(tvb); + + if (!try_val_to_str(epl_mtyp, mtyp_vals)) { + /* Not an EPL packet */ + return 0; + } + + /* Make entries in Protocol column and Info column on summary display */ + col_set_str(pinfo->cinfo, COL_PROTOCOL, udpencap ? "POWERLINK/UDP" : "POWERLINK"); /* tap */ /* mi.epl_mtyp = epl_mtyp; @@ -2607,7 +2612,7 @@ dissect_eplpdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean udp break; default: /* no valid EPL packet */ - return FALSE; + return 0; } if (tree) |