From: Matthieu Baerts <matttbe@kernel.org>
To: Shardul Bankar <shardulsb08@gmail.com>, martineau@kernel.org
Cc: geliang@kernel.org, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, horms@kernel.org,
netdev@vger.kernel.org, mptcp@lists.linux.dev,
linux-kernel@vger.kernel.org, janak@mpiric.us,
kalpan.jani@mpiricsoftware.com,
Shardul Bankar <shardul.b@mpiricsoftware.com>
Subject: Re: [PATCH] mptcp: add per-reason MIB counters for MPTCP_RST_EMPTCP resets
Date: Tue, 21 Apr 2026 12:14:23 +0200 [thread overview]
Message-ID: <3dbda2d2-c7e5-4a12-90c0-d1f98e3d89ee@kernel.org> (raw)
In-Reply-To: <20260421095646.3741956-1-shardul.b@mpiricsoftware.com>
Hi Shardul,
On 21/04/2026 11:56, Shardul Bankar wrote:
> MPTCP_RST_EMPTCP (reset reason 1) is used as a catch-all for seven
> distinct error conditions across subflow setup, authentication, and
> data path validation. The existing MPRstTx/MPRstRx counters only
> track aggregate reset volume, making it difficult to diagnose which
> code path is triggering subflow resets in production.
>
> Add per-reason MIB counters for each MPTCP_RST_EMPTCP use site:
>
> MPRstMD5SIG - MD5SIG on listener, incompatible with MPTCP
> MPRstNoToken - JOIN token lookup failed, no matching conn
> MPRstNoMPJ - SYN/ACK missing MP_JOIN option
> MPRstHMAC - HMAC validation failed during subflow join
> MPRstFatalFallback - fatal fallback during child socket creation
> MPRstBadMap - invalid data mapping on established subflow
> MPRstNotEstablished - JOIN on not-fully-established msk
>
> These counters are incremented alongside the existing reset_reason
> assignment and are visible via nstat as MPTcpExtMPRst*. The
> aggregate MPRstTx/MPRstRx counters remain unchanged.
Thank you for this patch.
Even if the patch looks globally good, net-next is currently closed, and
only bug fixes are accepted, see:
https://docs.kernel.org/process/maintainer-netdev.html
pw-bot: defer
Instead, I suggest switching the discussions only on the MPTCP ML: I
will try to review this patch and only send a reply to you and the MPTCP
list, if that's OK.
Cheers,
Matt
--
Sponsored by the NGI0 Core fund.
next prev parent reply other threads:[~2026-04-21 10:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-21 9:56 [PATCH] mptcp: add per-reason MIB counters for MPTCP_RST_EMPTCP resets Shardul Bankar
2026-04-21 10:14 ` Matthieu Baerts [this message]
2026-04-21 10:24 ` Shardul Bankar
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