Hierarchy of fields & offsets

["Sultan, Hassan via Wireshark-dev" <wireshark-dev () wireshark org>]

Hi,

Looking at some of the parsed data in my trials, I am seeing odd things such as :

format is :
[ftenum] [offset] [name or abbrev] ([length]) : <content, either from the ftvalue or from interpreted raw bytes>

FT_PROTOCOL 66 mysql(9) :
                FT_UINT24 66 mysql.packet_length(3) : 5
                FT_UINT8 69 mysql.packet_number(1) : 0
                FT_NONE 70 mysql.request(1) : 02
                                FT_UINT8 70 mysql.command(1) : 2
                                FT_STRING 71 mysql.schema(4) : test

Notice how mysql.command and mysql.schema are in the hierarchy children of mysql.request, however mysql.request's 
length is only 1 byte.

                                FT_BYTES 198 smb2.security_blob(120) : 
60:76:06:06:2b:06:01:05:05:02:a0:6c:30:6a:a0:3c:30:3a:06:0a:2b:06:01:04:01:82:37:02:02:1e:06:09:2a:86:48:82:f7:12:01:02:02:06:09:2a:86:48:86:f7:1
2:01:02:02:06:0a:2a:86:48:86:f7:12:01:02:02:03:06:0a:2b:06:01:04:01:82:37:02:02:0a:a3:2a:30:28:a0:26:1b:24:6e:6f:74:5f:64:65:66:69:6e:65:64:5f:69:6e:5f:52:46:43:34:31:37:38:40:70:6c:65:61:73:65:5f:69:6
7:6e:6f:72:65
                                                FT_UINT32 190 smb2.olb.offset(2) : 0x00000080
                                                FT_UINT32 192 smb2.olb.length(2) : 120
                                                FT_PROTOCOL 198 gss-api(120) :

Notice how smb2.olb.offset & smb2.olb.length are under smb2.security_blob, but their offset starts at 190/192 while 
smb2.security_blob starts at 198

This is extremely confusing to say the least and it makes it very hard to interpret the data in an automated manner. 
Any reason why this is done in this way ? I would personally expect a "parent" field to have offset/length that are 
consistent with its children.

Thanks,

Hassan


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