Re: [PATCH] net: allow unbound socket for packets in VRF when tcp_l3mdev_accept set

[David Ahern <dsahern@kernel.org>]

On 7/25/22 12:14 PM, Mike Manning wrote:
> The commit 3c82a21f4320 ("net: allow binding socket in a VRF when
> there's an unbound socket") changed the inet socket lookup to avoid
> packets in a VRF from matching an unbound socket. This is to ensure the
> necessary isolation between the default and other VRFs for routing and
> forwarding. VRF-unaware processes running in the default VRF cannot
> access another VRF and have to be run with 'ip vrf exec <vrf>'. This is
> to be expected with tcp_l3mdev_accept disabled, but could be reallowed
> when this sysctl option is enabled. So instead of directly checking dif
> and sdif in inet[6]_match, here call inet_sk_bound_dev_eq(). This
> allows a match on unbound socket for non-zero sdif i.e. for packets in
> a VRF, if tcp_l3mdev_accept is enabled.
> 
> Fixes: 3c82a21f4320 ("net: allow binding socket in a VRF when there's an unbound socket")
> Signed-off-by: Mike Manning <mvrmanning@gmail.com>
> Link: https://lore.kernel.org/netdev/a54c149aed38fded2d3b5fdb1a6c89e36a083b74.camel@lasnet.de/
> ---
> 
> Nettest results for VRF testing remain unchanged:
> 
> $ diff nettest-baseline-502c6f8cedcc.txt nettest-fix.txt
> $ tail -3 nettest-fix.txt
> Tests passed: 869
> Tests failed:   5
> 
> Disclaimer: While I do not think that there should be any noticeable
> socket throughput degradation due to these changes, I am unable to
> carry out any performance tests for this, nor provide any follow-up
> support if there is any such degradation.
> 
> ---
>  include/net/inet6_hashtables.h |  7 +++----
>  include/net/inet_hashtables.h  | 19 +++----------------
>  include/net/inet_sock.h        | 11 +++++++++++
>  3 files changed, 17 insertions(+), 20 deletions(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>