From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 04D393D34AC; Tue, 1 Sep 2026 02:50:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788231052; cv=none; b=gMBXrrXx8Gg4/0ujGxRNn1dB3NiSLJAopdyDAiXNqGJoqEzQSBW3tpInorSaxi0k1tQYgCRp3EucuCwd3b0RbHK5HxHHI+5d6RYLNcayX951J/1jRAJMgyAncUpP8+qc6u0dq2d+jLk0byFf8ryt3VY0ziBXXVq/RX248ntH5nA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788231052; c=relaxed/simple; bh=ZgbpiglFmXriEEzaxEnIAR4/mOVrlXP3jDIVgf830oc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dw0/k9lhhv7wiI9AFbeD4ExAe3CTQXc25rLsYC4RoloeYCGU1nJhhOCRiXOFx7YX8XpD2n0H23l1kOMzTXZShg1HRb7lZGwEZAHwiaUFS7xij8R0jtsJd3YnmbnWo2VlxJWckplSIU3QDMp203w5BGQAl7EN/HppMLBDznYPxfs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Cwx+fyaT; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Cwx+fyaT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1788231048; x=1819767048; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ZgbpiglFmXriEEzaxEnIAR4/mOVrlXP3jDIVgf830oc=; b=Cwx+fyaTpvIhXIgPqvpI2ij+MZddEWZwA+v3bt5sRanNW2Qg6rJFLiLq 49K3+f//DzBPZKB+YQebM8QQs1Cmv3LDeZYqSXkx5lsgPBe6uCi7BjK6O mp3KaFcbrNa9HcR4NaP5YyZ/uoeQYHfCZEVzH2pRLHGv8A8FYd91/I4qO BPMls76DwsMnk6JZnYcvvpcvJpqK5qcyrqfjQW9J3t4LRznnChXri/qwm UW2H0CLqdKYAyBBK6nJVhbPdL8KEZlN0pcxsmU8oBOhhR8FhujUl2jVZb uaDlG5YdqSxCH6pVnhpeeB2pgjy9ze9Fs1X5R4DE88GBSKxC1qrk4va9G A==; X-CSE-ConnectionGUID: 76WxSiWeTaOsJgUrrthxCA== X-CSE-MsgGUID: NyGSjhTER/+QugYI3+dRfQ== X-IronPort-AV: E=McAfee;i="6800,10657,11892"; a="87784667" X-IronPort-AV: E=Sophos;i="6.25,255,1779174000"; d="scan'208";a="87784667" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2026 19:50:46 -0700 X-CSE-ConnectionGUID: Z5kr0kPFSuiDHesALIYv1w== X-CSE-MsgGUID: ykezKnKsSf2uySwfGfH1kQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,255,1779174000"; d="scan'208";a="272471874" Received: from junjie-desk-dev.bj.intel.com ([10.238.152.71]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2026 19:50:44 -0700 From: Junjie Cao To: David Ahern Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, idosch@nvidia.com, fmancera@suse.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v2] net: dropreason: add SKB_DROP_REASON_IP_TTL_EXCEEDED Date: Tue, 1 Sep 2026 10:50:32 +0800 Message-ID: <20260901025032.418077-1-junjie.cao@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <7afff157-a5ed-459a-9b40-47123efd71e1@kernel.org> References: <7afff157-a5ed-459a-9b40-47123efd71e1@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Mon, Aug 31, 2026 at 8:23 PM David Ahern wrote: > what about icmp_unreach, ip_expire, and other sources of > ICMP_TIME_EXCEEDED? The reason code applies to more than just forwarding > paths. ip_expire and ip6frag_expire_frag_queue already report FRAG_REASM_TIMEOUT. That is the reassembly timer (code FRAGTIME), not a TTL, so it stays. icmp_unreach is the receiver of a time-exceeded; no packet expires there. That leaves IPVS decrement_ttl(): it sends the ICMP, and the callers then free the skb at their tx_error labels with plain kfree_skb(). A reason there has to come out of __ip_vs_get_out_rt(), so that is a separate patch. > similarly for IPv6, there are more ICMPV6_TIME_EXCEED cases than just > the forwarding path. Same picture: frag expiry has FRAG_REASM_TIMEOUT, IPVS is the gap, and ip6_err_gen_icmpv6_unreach only translates a received v4 error for sit and gre. The kernel-doc says "on a packet being forwarded"; v3 drops the qualifier.