Re: git: 50fa27e795ea - main - netinet6: fix interface handling for loopback traffic

From: Bjoern A. Zeeb <bz_at_FreeBSD.org>
Date: Sun, 10 Jul 2022 16:59:36 UTC
On Sun, 10 Jul 2022, Alexander V. Chernikov wrote:

>
>
>> On 10 Jul 2022, at 14:32, Bjoern A. Zeeb <bz@FreeBSD.org> wrote:
>>
>> On Sun, 10 Jul 2022, Alexander V. Chernikov wrote:
>>
>>> The branch main has been updated by melifaro:
>>>
>>> URL: https://cgit.FreeBSD.org/src/commit/?id=50fa27e795eaae97dae87ac4532799f7aea87e9f
>>>
>>> commit 50fa27e795eaae97dae87ac4532799f7aea87e9f
>>> Author: Alexander V. Chernikov <melifaro@FreeBSD.org>
>>> AuthorDate: 2022-07-10 12:27:23 +0000
>>> Commit: Alexander V. Chernikov <melifaro@FreeBSD.org>
>>> CommitDate: 2022-07-10 12:47:47 +0000
>>>
>>> netinet6: fix interface handling for loopback traffic
>>>
>>> Currently, processing of IPv6 local traffic is partially broken:
>>> link-local connection fails and global unicast connect() takes
>>> 3 seconds to complete.
>>> This happens due to the combination of multiple factors.
>>> IPv6 code passes original interface "origifp" when passing
>>> traffic via loopack to retain the scope that is mandatory for the
>>> correct hadling of link-local traffic. First problem is that the logic
>>> of passing source interface is not working correcly for TCP connections,
>>> resulting in passing "origifp" on the first 2 connection attempts and
>>> lo0 on the subsequent ones. Second problem is that source address
>>> validation logic skips its checks iff the source interface is loopback,
>>> which doesn't cover "origifp" case.
>>> More detailed description is available at https://reviews.freebsd.org/D35732
>>>
>>> Fix the first problem by untangling&simplifying ifp/origifp logic.
>>> Fix the second problem by switching source address validation check to
>>> using M_LOOP mbuf flag instead of interface type.
>>>
>>> PR: 265089
>>> Reviewed by: ae, bz(previous version)
>>
>> I did not review, I had only commented on D35117.
> Sorry, I chose a wrong wording for mentioning the discussion happened.
> Do you prefer me to rollback/commit with an updated message?

No,  I would have prefered more than 4 days of time to look at the
updated changes after 4 months, but I can still do that now that
things are in.

Just keep going, we'll take it from here.


>>
>>
>>> Differential Revision: https://reviews.freebsd.org/D35732
>>> MFC after: 2 weeks
>>> ---
>>> sys/netinet6/ip6_input.c | 2 +-
>>> sys/netinet6/ip6_output.c | 61 ++++++++++++++++++-----------------
>>> tests/sys/netinet6/test_ip6_output.py | 4 +--
>>> 3 files changed, 35 insertions(+), 32 deletions(-)
>>
>> --
>> Bjoern A. Zeeb r15:7
>
>

-- 
Bjoern A. Zeeb                                                     r15:7