Re: [PATCH tracing 0/3] tracing: support > 8 byte filter predicates

From: Alan Maguire
Date: Wed Apr 26 2023 - 04:51:32 EST


On 25/04/2023 18:20, Steven Rostedt wrote:
> On Tue, 25 Apr 2023 18:15:03 +0100
> Alan Maguire <alan.maguire@xxxxxxxxxx> wrote:
>
>> that's a great idea; what would be the most consistent ftrace syntax
>> for this do you think? I noticed that hist triggers append a modifier
>> to the field name so would something like
>>
>> "dst.ipv6 == ::1"
>
> Yeah, I think just having ":" in the name without quotes can help the filter
> know that it's a ipv6 id.
>
> Hmm, although we may want to do the same for mac addresses. But we can
> determine the difference by the field size. If it's 6 bytes, it's a mac, if
> it's 128 bits, then ipv6.
>

good idea! so what about the following

- 16 byte field with ':'; convert from IPv6 address before memcmp()ing
- 6 byte field with ':'; convert from MAC address before memcmp()ing
- 4 byte field with '.'; convert from IPv4 address before memcmp()ing
- 0x prefix, any other size; basic memcmp

? Thanks!

Alan

> -- Steve
>