From nobody Mon Dec 8 16:28:35 2025 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4dQ6qS44Bqz6K2tm for ; Mon, 08 Dec 2025 16:28:36 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4dQ6qS34jQz3KL8 for ; Mon, 08 Dec 2025 16:28:36 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1765211316; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yUnUbsdV1j91rJgK49/T8VS1LOHO7A7rm3Z9/rnkRsY=; b=GT/yEg7zt4+d9LL6v0dx3E+SaZG/Vb2dyGrWEAxbyPU7RyFcKToiEeUGj/lEUj9iTvlsBJ BWZ0K017Q9QD9HbHG17Fc6SfYdZim0mClINkXo9B9LeiVq0+iBXK4nkjIQrfSUspRLWt98 VG/YRLFz6onYBzaapMajRAy2oIDXH0BAPUdx/sqvfCrP2udjYe1FiZi5wE2bdH04/Dv/kv 3TDgq/xpZDrqs8HrpAxRByeQQqFnfZ8a6mUMTmpLM5C5Squg6GQaV863Npa1Qttcidybmb m9kkoQDwU7KlGPh4QfvLuE0qxonUm/quQkEIcQDEfxa8oqV7V0fcV2VsVbVbIA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1765211316; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yUnUbsdV1j91rJgK49/T8VS1LOHO7A7rm3Z9/rnkRsY=; b=H3oash+sG6Knm83HBdT87Eas9KphxBDByfuCJFIolTV7SRABZm4xnfCaaXALxteNp0rjCd CErICMa5N4J0OhHraIwXCK8wKNb4WSYX1ZeLBbWax+rpfWKhhhcsIliu1QfSjDmrkYzIPI 0rhvhscGtEZHg60YgeI2LPwtvUCI4KGGVzGWZkckxcFnTs9Ajjej3a/B1H2wJ0Ab4gWCct NepbnqpJixApF4EPNGLVR7uDaZv9I5Aq+ZHiMc84CVjKTGC4NfPgFZOgkSyIOLC6+DGGNj QitkHLvxSggpcZnath0+YwLQ8y2UQ6U3GwST+eADzOZY2as6TiD2ixWomNuBNA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1765211316; a=rsa-sha256; cv=none; b=HzCNsxyi0VPYI3jhguxNhJyYbnR+0vCXzJpW5JT1rSdIzq+/11RmCR/xOqN/0fOznTRxDe /uTbH4YLdDWNoL4s01EjwDcJIdUkdRKif6p9/9Fb1pbpMOrOtxyJJx5YjaQjHmVjpsyjBj ekJdlZhf/fO0jES+wGzNsVbeCzFd32kLTdwHMiew8G0S6wqaGaQgUK4KaAidBiLsR5TPPP YDvJoDOGe4skLO9H++24UTjW4rHUQ+siYFTlsNeCwhiwSbqYdx3wRY2HAlr6n6j3NI1FlS jD1MJD7rmw4mSPJglBfhyzI1cyptIaXlkbgNV3rnqJP6c1+6Ql23YSc//1ygdw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4dQ6qS2Y0Cz4ZY for ; Mon, 08 Dec 2025 16:28:36 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 5B8GSaTR037758 for ; Mon, 8 Dec 2025 16:28:36 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 5B8GSari037757 for net@FreeBSD.org; Mon, 8 Dec 2025 16:28:36 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 291420] [epair] Bad UDP packet checksum with epair(4) and txcsum enabled Date: Mon, 08 Dec 2025 16:28:35 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 14.3-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: tuexen@freebsd.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: net@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@FreeBSD.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D291420 --- Comment #10 from Michael Tuexen --- I am pretty sure that https://cgit.freebsd.org/src/commit/sys/net/if_epair.c?h=3Dstable/14&id=3D5= 03bf058cd0adfe3d5e66340b13d32b4516390cb results in the problem you are experiencing. If you disable txcsum on the epair interface, the problem goes away. I just want to understand the root cause of the problem. If I understand your data correctly, then the problem goes away if you set forced_udpcsum to 1. I think the problem should be limited to UDP, because bge devices announce TXCSUM support, but only do this for TCP, whereas the implicit assumption by the rest of the system is that TCP and UDP is supported. Setting forced_udp= csum to 1 enforces support for UDP. The default is forced_udpcsum =3D 0, since Broadcom NICs don't compute the UDP always correctly (I am not sure if this= is currently fixed). We try to reproduce it in my lab, but we need to test it on a system with a Broadcom NIC. Once it is clear, we will work on a solution. As a workaround you can just disable txcsum for the epair interface. --=20 You are receiving this mail because: You are the assignee for the bug.=