diff options
| author | Eric Wetzel <thewetzel@gmail.com> | 2017-05-17 22:17:30 -0400 |
|---|---|---|
| committer | Graham Bloice <graham.bloice@trihedral.com> | 2017-05-21 21:58:41 +0000 |
| commit | b3c68951913497d0797614636ef6784becb1a5b6 (patch) | |
| tree | ddbf3569776173d58b67351ac4121cf7e17c90e7 /epan/dissectors/packet-dnp.c | |
| parent | 333711430a0af68916adeac462a4652fb690baa4 (diff) | |
dnp3: fix parser when a packed variation is used with prefix value qualifier
Bug: 13733
Change-Id: I4d490793b54816e731d72bf1317d3779a05ae011
Reviewed-on: https://code.wireshark.org/review/21722
Petri-Dish: Graham Bloice <graham.bloice@trihedral.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Graham Bloice <graham.bloice@trihedral.com>
Diffstat (limited to 'epan/dissectors/packet-dnp.c')
| -rw-r--r-- | epan/dissectors/packet-dnp.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/epan/dissectors/packet-dnp.c b/epan/dissectors/packet-dnp.c index 0f23291964..2f5aa224b6 100644 --- a/epan/dissectors/packet-dnp.c +++ b/epan/dissectors/packet-dnp.c @@ -1870,6 +1870,7 @@ dnp3_al_process_object(tvbuff_t *tvb, packet_info *pinfo, int offset, offset += 2 + da_len; break; } + /* Bit-based Data objects here */ case AL_OBJ_BI_1BIT: /* Single-Bit Binary Input (Obj:01, Var:01) */ case AL_OBJ_BO: /* Binary Output (Obj:10, Var:01) */ @@ -1877,9 +1878,8 @@ dnp3_al_process_object(tvbuff_t *tvb, packet_info *pinfo, int offset, case AL_OBJ_IIN: /* Internal Indications - IIN (Obj: 80, Var:01) */ /* Extract the bit from the packed byte */ - al_bi_val = tvb_get_guint8(tvb, offset); - al_bit = (al_bi_val & (1 << bitindex)) > 0; - + al_bi_val = tvb_get_guint8(tvb, data_pos); + al_bit = (al_bi_val & 1) > 0; if (al_obj == AL_OBJ_IIN) { /* For an IIN bit, work out the IIN constant value for the bit position to get the name of the bit */ guint16 iin_bit = 0; @@ -1892,10 +1892,20 @@ dnp3_al_process_object(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_item_append_text(point_item, " (%s), Value: %u", val_to_str_const(iin_bit, dnp3_al_iin_vals, "Invalid IIN bit"), al_bit); } - else { + else + { + if (al_objq_prefix != AL_OBJQL_PREFIX_NI) { + /* Each item has an index prefix, in this case bump + the bitindex to force the correct offset adjustment */ + bitindex = 7; + } + else { + /* Regular packed bits, get the value at the appropriate bit index */ + al_bit = (al_bi_val & (1 << bitindex)) > 0; + } proto_item_append_text(point_item, ", Value: %u", al_bit); } - proto_tree_add_boolean(point_tree, hf_dnp3_al_bit, tvb, offset, 1, al_bit); + proto_tree_add_boolean(point_tree, hf_dnp3_al_bit, tvb, data_pos, 1, al_bit); proto_item_set_len(point_item, prefixbytes + 1); /* Increment the bit index for next cycle */ |