Wireshark mailing list archives
Re: New syntax for range support in membership operator: tcp.port in {1662-1664}
From: Jasper Bongertz <jasper () packet-foo com>
Date: Sun, 15 Apr 2018 16:28:33 +0200
Hi, +1 for the double dot syntax. Cheers, Jasper Sunday, April 15, 2018, 3:03:53 PM, you wrote:
Hi,
In fact I would suggest to consider double dot (‘..’) in this case. Reasons: * It is a sufficiently unique operator * The minus causes too many conflicts, as you have stated * triple dot (‘...’, i.e. Ellipsis) is too prone to ‘autocorrection’ to the ellipsis symbol, causing copy-paste problems.
Regards, Jaap
On 15 Apr 2018, at 13:24, Peter Wu <peter () lekensteyn nl> wrote:
Hi,
Laura requested support for ranges for the "in" display filter operator in bug 1480 which seems like a reasonable idea. I have a prototype patch working here: https://code.wireshark.org/review/26945
The initial implementation converted "f in {a-b}" to "f >= a && f <= b", but this turned out to be problematic when a field has multiple occurrences. To solve this, I added a new ANY_IN_RANGE DVFM instruction that checks each field against the range.
One remaining issue is the syntax. The proposed syntax looks a bit ugly with negative numbers, and is also not implemented for things other than numbers. It can also be ambiguous.
Example: find SMB server timezone within UTC-0700 and UTC-0400):
smb.server_timezone in {-420--240}
Example: find all hosts in range 10.0.0.10-10.0.0.60. The CIDR notation cannot be used to match this, instead you need something verbose like:
(ip.src >= 10.0.0.10 and ip.src <= 10.0.0.60) or (ip.dst >= 10.0.0.10 and ip.dst <= 10.0.0.60)
A potential shorter version (not supported at the moment):
ip.addr in {10.0.0.10-10.0.0.60}
Another issue: the filter "data.data==1-3" is interpreted as matching bytes "0103" (because data.data is of type FT_BYTES). The display filter "data.data in {1-3}" is currently ambiguous (previously it matched the previous "==" filter, after my patch it becomes "a single byte in range 01 to 03"). One way to address this is to treat only "01:02:03" as byte patterns and forbid "01-02-03".
With these cases, do you think that using "-" is a good range operator for the set membership operator? An alternative range syntax suggestion was proposed in doc/README.display_filter as:
(x in {a ... z})
Some possible ideas (I don't really like them to be honest):
tcp.srcport in { 80 1662 ... 1664 } tcp.srcport in { 80 1662 .. 1664 } tcp.srcport in { 80 [1662, 1664] } tcp.srcport in { 80 range(1662, 1664) }
Feedback is welcome! -- Kind regards, Peter Wu https://lekensteyn.nl
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Current thread:
- New syntax for range support in membership operator: tcp.port in {1662-1664} Peter Wu (Apr 15)
- Re: New syntax for range support in membership operator: tcp.port in {1662-1664} Jaap Keuter (Apr 15)
- Re: New syntax for range support in membership operator: tcp.port in {1662-1664} Jasper Bongertz (Apr 15)
- Re: New syntax for range support in membership operator: tcp.port in {1662-1664} Roland Knall (Apr 15)
- Re: New syntax for range support in membership operator: tcp.port in {1662-1664} Jasper Bongertz (Apr 15)
- Re: New syntax for range support in membership operator: tcp.port in {1662-1664} Jaap Keuter (Apr 15)