Re: git: 54c62e3e5d8c - main - pf: work around icmp6 packet-too-big not being sent when binat-ing

On 23 Jan 2024, at 19:32, Herbert J. Skuhra wrote:
> On Mon, 22 Jan 2024 13:52:51 +0100, Kristof Provost wrote:
>>
>> The branch main has been updated by kp:
>>
>> URL: https://cgit.FreeBSD.org/src/commit/?id=54c62e3e5d8cd90c5571a1d4c8c5f062d580480e
>>
>> commit 54c62e3e5d8cd90c5571a1d4c8c5f062d580480e
>> Author:     Kristof Provost <kp@FreeBSD.org>
>> AuthorDate: 2024-01-17 17:11:27 +0000
>> Commit:     Kristof Provost <kp@FreeBSD.org>
>> CommitDate: 2024-01-22 11:52:14 +0000
>>
>>     pf: work around icmp6 packet-too-big not being sent when binat-ing
>>
>>     If we're applying NPTv6 we pass a packet with a modified source and/or
>>     destination address to the network stack.
>>
>>     If that packet then turns out to be larger than the MTU of the sending
>>     interface the stack will attempt to generate an icmp6 packet-too-big
>>     error, but may fail to look up the appropriate source address for that
>>     error message. Even if it does, pf would still have to undo the binat
>>     operation inside the icmp6 packet so the sending host can make sense of
>>     the error.
>>
>>     We can avoid both problems entirely by having pf also perform the MTU
>>     check (taking the potential refragmentation into account), and
>>     generating the icmp6 error directly in pf.
>>
>>     See also:       https://redmine.pfsense.org/issues/14290
>>     Sponsored by:   Rubicon Communications, LLC ("Netgate")
>>     Differential Revision:  https://reviews.freebsd.org/D43499
>> ---
>>  sys/net/pfvar.h          |  1 +
>>  sys/netpfil/pf/pf.c      | 12 ++++++++++++
>>  sys/netpfil/pf/pf_norm.c | 15 +++++++++++++++
>>  3 files changed, 28 insertions(+)
>
> Does this change cause problems for others too?
>
> - ssh over IPv6 permanently disconnecting
> (client_loop: send disconnect: Broken pipe)
> - ssh connections over IPv6 hanging
> - git pull not working
> Fssh_ssh_dispatch_run_fatal: Connection to 2604:1380:4091:a001::24ca:1 port 22: Permission denied
> fatal: Could not read from remote repository.
>
Can you include your pf.conf and a packet capture demonstrating one of these issues?

Best regards,
Kristof