[PATCH mptcp-net] mptcp: fix for setting remote ipv4mapped address

[PATCH mptcp-net] mptcp: fix for setting remote ipv4mapped address

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Commit 1c670b39cec7 ("mptcp: change local addr type of subflow_destroy")
introduced a bug in mptcp_pm_nl_subflow_destroy_doit().

ipv6_addr_set_v4mapped() should be called to set the remote ipv4 address
'addr_r.addr.s_addr' to the remote ipv6 address 'addr_r.addr6', not
'addr_l.addr.addr6', which is the local ipv6 address.

Fixes: 1c670b39cec7 ("mptcp: change local addr type of subflow_destroy")
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_userspace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 740a10d669f8..a3d477059b11 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -520,7 +520,7 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 		addr_l.addr.family = AF_INET6;
 	}
 	if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr.addr6)) {
-		ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_l.addr.addr6);
+		ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_r.addr6);
 		addr_r.family = AF_INET6;
 	}
 #endif
-- 
2.45.2

Re: [PATCH mptcp-net] mptcp: fix for setting remote ipv4mapped address

[MPTCP CI]

Hi Geliang,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal: Success! ✅
- KVM Validation: debug: Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/12502439231

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/349484af26de
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=920953


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Re: [PATCH mptcp-net] mptcp: fix for setting remote ipv4mapped address

[Matthieu Baerts]

Hi Geliang,

No need to cc Jakub for patches that are in review only on MPTCP side.
Please remove his address from the Cc list for the next replies.

On 26/12/2024 10:33, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> Commit 1c670b39cec7 ("mptcp: change local addr type of subflow_destroy")
> introduced a bug in mptcp_pm_nl_subflow_destroy_doit().
> 
> ipv6_addr_set_v4mapped() should be called to set the remote ipv4 address
> 'addr_r.addr.s_addr' to the remote ipv6 address 'addr_r.addr6', not
> 'addr_l.addr.addr6', which is the local ipv6 address.

Good catch! How did you notice that? It looks like we are currently not
validating this part:

https://ci-results.mptcp.dev/lcov/export/mptcp/pm_userspace.c.gcov.html#L519

Is it because you are looking at adding tests covering this?

> Fixes: 1c670b39cec7 ("mptcp: change local addr type of subflow_destroy")

This commit is only in net-next, not in -net. So I'm going to apply it
in "Fixes for net-next" ("mptcp-next" then).

Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.

Re: [PATCH mptcp-net] mptcp: fix for setting remote ipv4mapped address

[Matthieu Baerts]

Hi Geliang,

(-cc Jakub)

On 26/12/2024 10:33, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> Commit 1c670b39cec7 ("mptcp: change local addr type of subflow_destroy")
> introduced a bug in mptcp_pm_nl_subflow_destroy_doit().
> 
> ipv6_addr_set_v4mapped() should be called to set the remote ipv4 address
> 'addr_r.addr.s_addr' to the remote ipv6 address 'addr_r.addr6', not
> 'addr_l.addr.addr6', which is the local ipv6 address.
> 
> Fixes: 1c670b39cec7 ("mptcp: change local addr type of subflow_destroy")

Now in our tree (fixes for next):

New patches for t/upstream:
- 9da48b72c233: mptcp: fix for setting remote ipv4mapped address
- Results: 472bd4bb9bf0..f770d70d123d (export)

Tests are now in progress:

- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/280f4e69601cbcb770ac1095b6e3c968de2de6a3/checks

I will send it later, when net-next will re-open.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.