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wireshark
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Simplify code .... 

svn path=/trunk/; revision=43665
This commit is contained in:
Bill Meier 2012-07-11 18:32:20 +00:00
parent 3b7e75852a
commit 85504b052f
1 changed files with 88 additions and 117 deletions
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205
epan/dissectors/packet-assa_r3.c
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@ -9773,127 +9773,107 @@ static gint dissect_r3_command (tvbuff_t *tvb, guint32 start_offset, guint32 len
/*
* ***************************************************************************
*
* Dissect a single packet, return bytes consumed
* Dissect a single r3 PDU
*
* Return either:
* >0 = number of bytes consumed
* 0 = packet is just the right length
* <0 = need more bytes
* return: amount consumed
*/
static gint dissect_r3_packet (tvbuff_t *tvb, guint start_offset, packet_info *pinfo, proto_tree *r3_tree)
static int dissect_r3_packet (tvbuff_t *tvb, packet_info *pinfo, proto_tree *r3_tree)
{
guint offset = 0;
guint octConsumed;
gint available = tvb_length_remaining (tvb, start_offset);
proto_item *payload_item = NULL;
proto_tree *payload_tree = NULL;
guint offset = 0;
guint packetLen;
guint octConsumed;
if (tvb_strneql (tvb, start_offset, "~~~ds", 5) == 0)
if (tvb_strneql (tvb, 0, "~~~ds", 5) == 0)
{
if (r3_tree)
proto_tree_add_item (r3_tree, hf_r3_tildex3ds, tvb, start_offset + 0, -1, ENC_ASCII|ENC_NA);
proto_tree_add_item (r3_tree, hf_r3_tildex3ds, tvb, 0, -1, ENC_ASCII|ENC_NA);
offset = start_offset + 5;
return 5;
}
else
{
gint packetLen = 0;
if (available < 4)
return available - 4;
/*
* Show basic header stuff
*/
if (r3_tree)
{
proto_item *header_item = proto_tree_add_item (r3_tree, hf_r3_header, tvb, 0, 5, ENC_NA);
proto_tree *header_tree = proto_item_add_subtree (header_item, ett_r3header);
proto_tree_add_item (header_tree, hf_r3_sigil, tvb, 0, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_address, tvb, 1, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_packetnumber, tvb, 2, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_packetlength, tvb, 3, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_encryption, tvb, 4, 1, ENC_LITTLE_ENDIAN);
}
/* Note: packetLen == tvb_reported_length() */
packetLen = tvb_get_guint8 (tvb, 3);
if (r3_tree)
{
payload_item = proto_tree_add_item (r3_tree, hf_r3_payload, tvb, 5, -1, ENC_NA);
payload_tree = proto_item_add_subtree (payload_item, ett_r3payload);
}
offset = 5;
mfgCommandFlag = FALSE; /* XXX: Assumption: mfgCmd always follows Cmd in same r3 "packet" */
while (offset < (packetLen - 3))
{
octConsumed = dissect_r3_command (tvb, offset, 0, pinfo, payload_tree);
if(octConsumed == 0)
{
expert_add_info_format (pinfo, proto_tree_get_parent (payload_tree), PI_MALFORMED, PI_WARN,
"Command length equal to 0; payload could be partially decoded");
offset = tvb_reported_length (tvb) - 3; /* just do CRC stuff ?? */
break;
}
offset += octConsumed;
}
/*
* Show the CRC and XOR status
*/
if (r3_tree)
{
proto_item *tail_item = proto_tree_add_item (r3_tree, hf_r3_tail, tvb, offset, 3, ENC_NA);
proto_tree *tail_tree = proto_item_add_subtree (tail_item, ett_r3tail);
guint32 packetCRC = tvb_get_letohs (tvb, offset);
guint32 packetXor = tvb_get_guint8 (tvb, offset + 2);
guint32 calculatedCRC;
if ((calculatedCRC = utilCrcCalculate (tvb_get_ptr (tvb, 1, packetLen - 3), packetLen - 3, 0x0000)) == packetCRC)
proto_tree_add_uint_format (tail_tree, hf_r3_crc, tvb, offset, 2, packetCRC, "CRC: 0x%04x (correct)", packetCRC);
else
{
packetLen = tvb_get_guint8 (tvb, start_offset + 3) + 1;
proto_item *tmp_item;
if (packetLen > available)
return available - packetLen;
proto_tree_add_uint_format (tail_tree, hf_r3_crc, tvb, offset, 2, packetCRC,
"CRC: 0x%04x (incorrect, should be 0x%04x)", calculatedCRC, packetCRC);
tmp_item = proto_tree_add_boolean (tail_tree, hf_r3_crc_bad, tvb, offset, 2, TRUE);
PROTO_ITEM_SET_GENERATED (tmp_item);
}
packetLen -= 1;
/*
* Show basic header stuff
*/
if (r3_tree)
if ((packetLen ^ 0xff) == (int)packetXor)
proto_tree_add_uint_format (tail_tree, hf_r3_xor, tvb, offset + 2, 1, packetXor,
"XOR: 0x%02x (correct)", packetXor);
else
{
proto_item *header_item = proto_tree_add_item (r3_tree, hf_r3_header, tvb, start_offset + 0, 5, ENC_NA);
proto_tree *header_tree = proto_item_add_subtree (header_item, ett_r3header);
proto_item *tmp_item;
proto_tree_add_item (header_tree, hf_r3_sigil, tvb, start_offset + 0, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_address, tvb, start_offset + 1, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_packetnumber, tvb, start_offset + 2, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_packetlength, tvb, start_offset + 3, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_item (header_tree, hf_r3_encryption, tvb, start_offset + 4, 1, ENC_LITTLE_ENDIAN);
proto_tree_add_uint_format (tail_tree, hf_r3_xor, tvb, offset + 7, 1, packetXor,
"XOR: 0x%02x (incorrect, should be 0x%02x)", packetXor, packetLen ^ 0xff);
tmp_item = proto_tree_add_boolean (tail_tree, hf_r3_xor_bad, tvb, offset + 7, 1, TRUE);
PROTO_ITEM_SET_GENERATED (tmp_item);
}
/*
* If the packet has enough data, try to decode it
*/
if (available > 8)
{
proto_item *payload_item = NULL;
proto_tree *payload_tree = NULL;
tvbuff_t *payload_tvb = tvb_new_subset (tvb, start_offset + 5, packetLen - 7, packetLen - 7);
if (r3_tree)
{
payload_item = proto_tree_add_item (r3_tree, hf_r3_payload, payload_tvb, 0, -1, ENC_NA);
payload_tree = proto_item_add_subtree (payload_item, ett_r3payload);
}
mfgCommandFlag = FALSE; /* XXX: Assumption: mfgCmd always follows Cmd in same r3 "packet" */
while (offset < tvb_reported_length (payload_tvb))
{
octConsumed = dissect_r3_command (payload_tvb, offset, 0, pinfo, payload_tree);
if(octConsumed == 0)
{
expert_add_info_format (pinfo, proto_tree_get_parent (payload_tree), PI_MALFORMED, PI_WARN,
"Command length equal to 0; payload could be partially decoded");
offset = tvb_reported_length (payload_tvb);
break;
}
offset += octConsumed;
}
}
offset += start_offset;
/*
* Show the CRC and XOR status
*/
if (r3_tree)
{
proto_item *tail_item = proto_tree_add_item (r3_tree, hf_r3_tail, tvb, offset + 5, 3, ENC_NA);
proto_tree *tail_tree = proto_item_add_subtree (tail_item, ett_r3tail);
guint32 packetCRC = tvb_get_letohs (tvb, offset + 5);
guint32 packetXor = tvb_get_guint8 (tvb, offset + 7);
guint32 calculatedCRC = 0;
if ((calculatedCRC = utilCrcCalculate (tvb_get_ptr (tvb, start_offset + 1, packetLen - 3), packetLen - 3, 0x0000)) == packetCRC)
proto_tree_add_uint_format (tail_tree, hf_r3_crc, tvb, offset + 5, 2, packetCRC, "CRC: 0x%04x (correct)", packetCRC);
else
{
proto_item *tmp_item;
proto_tree_add_uint_format (tail_tree, hf_r3_crc, tvb, offset + 5, 2, packetCRC, "CRC: 0x%04x (incorrect, should be 0x%04x)", calculatedCRC, packetCRC);
tmp_item = proto_tree_add_boolean (tail_tree, hf_r3_crc_bad, tvb, offset + 5, 2, TRUE);
PROTO_ITEM_SET_GENERATED (tmp_item);
}
if ((packetLen ^ 0xff) == (int)packetXor)
proto_tree_add_uint_format (tail_tree, hf_r3_xor, tvb, offset + 7, 1, packetXor, "XOR: 0x%02x (correct)", packetXor);
else
{
proto_item *tmp_item;
proto_tree_add_uint_format (tail_tree, hf_r3_xor, tvb, offset + 7, 1, packetXor, "XOR: 0x%02x (incorrect, should be 0x%02x)", packetXor, packetLen ^ 0xff);
tmp_item = proto_tree_add_boolean (tail_tree, hf_r3_xor_bad, tvb, offset + 7, 1, TRUE);
PROTO_ITEM_SET_GENERATED (tmp_item);
}
}
offset += 8;
}
return offset - start_offset;
offset += 3;
return offset;
}
/*
@ -9903,32 +9883,23 @@ static gint dissect_r3_packet (tvbuff_t *tvb, guint start_offset, packet_info *p
*/
static void dissect_r3_message (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_item *r3_item = NULL;
proto_tree *r3_tree = NULL;
guint offset = 0;
col_set_str (pinfo->cinfo, COL_PROTOCOL, "R3");
col_clear (pinfo->cinfo, COL_INFO);
/* Note: The tvb (provided via tcp_dissect_pdus()) will contain (at most) one PDU of the length
* specified via get_r3_message_len()
*/
if (tree)
{
proto_item *r3_item;
r3_item = proto_tree_add_item (tree, proto_r3, tvb, 0, -1, ENC_NA);
r3_tree = proto_item_add_subtree (r3_item, ett_r3);
}
while (offset < tvb_reported_length (tvb))
{
gint res = dissect_r3_packet (tvb, offset, pinfo, r3_tree);
if (res <= 0)
{
proto_item_set_len (r3_item, offset);
return;
}
offset += res;
}
dissect_r3_packet (tvb, pinfo, r3_tree);
return;
}