From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4227847CA98 for ; Wed, 29 Jul 2026 12:08:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785326885; cv=none; b=PCR8eSaXV3dkFS5GrYJ4LoMoZE8RM6NN4ziLzGiX8Dju7RtfVVVbr84TiFPmysLuwVtx85+uw0ljFKm6OpnesOofyrwoQ4hkwTT/DfgHhWM2pNctS74EWErAiJ1v8v61C5EQxKsycuBUpiryegU5FRESfrx/7gzYTqH5bz6511M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785326885; c=relaxed/simple; bh=sELrnQ2yMBL8rHoMgZ51jkox5afN/YK+bJqWLG9PKdI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hMyNDWrFiNci5otknOOikPX3Eca6XFnQNmCNygU5jRzU20FrJ34juZZUMyH+UNDeXloc0o6YQL1WuQfKZR+diMIR3JSQVaJnRyC6GInZReY1MdL5TGqqGia3LdEb1o/zvyHQMf5njUicW5g8nxzYMdfFm+0QGJig88UNwymqXbE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=QKAORy6i; arc=none smtp.client-ip=209.85.210.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QKAORy6i" Received: by mail-pf1-f182.google.com with SMTP id d2e1a72fcca58-84874b52eabso1147208b3a.0 for ; Wed, 29 Jul 2026 05:08:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785326883; x=1785931683; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Gu3aSZvtpbBhakJ45baaB5YSjEDUrp+D3QUTuf9uivo=; b=QKAORy6idMlUPwwEuIQ7n8PpNJocujHCL3Ec0aj0N/yyes+ThEhf66ra+3YXtbR192 A2RBG0phLFcmpm0Vun+vnNZmZbV6PsFMy+L+rrs1MB0WaZ8XV20ta/WLwtCWtwNXKHDD MPK7I/vfcHpHDNSPQwsYqqj+60C1qU5UN4XO/z6fn75tFFZ6bmmb0TWL51wiWD1jxohk POVKkwWwErPIYhaffexkeZ8gL88P9nnbxmvJOZdvgceQSrfHJOxbNL50emPj5qdceYRT 28UfOB2oaXQamaV8Lhd2E3eKzQmpLxmFhKjXaQVLJ/M1WJ9Ce/S/RjXo+a9LHxbxvW6m jZ4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785326883; x=1785931683; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=Gu3aSZvtpbBhakJ45baaB5YSjEDUrp+D3QUTuf9uivo=; b=TveCAxrNawCvXF8GpIJBH1//rBgmbucyk4MMilJroSztWHb7zxZA9aQGxRDcDAllqZ 5qQvBvddMWD8PeTxgJyhOXlEL+HSaRy7dIKkxMdmsR5VkE8N6d58mf8jcis7/F21nAy6 QxzHDxh9rMgsW1+/Ib9aZowV/18bJLetVRV0knCuAmp201CG2MRSLG5vXxScsPWym7aJ SANN2jzatxwCUa6uGOjHlyURFWoxVQLiq81OyElwRc2Xfayr8tVY2XwG2uVVZ3cPJg+8 x2Pqz+F0lkERWCPx/BRoivdo+zH/eVCztdfSeOAecaVOlRqC4gfJdupyAfXKA5Q89sNV jOog== X-Forwarded-Encrypted: i=1; AHgh+RojxkfTnx7k72fTjhk5CHsxF9UV61C/2+p9kqi3nJAWUeGjr+uUQE3EfmI+8Ulg/+OZs7icc+2b9QimEBw=@vger.kernel.org X-Gm-Message-State: AOJu0YyOmFKCuS3eovvXFRXWZuMDqktLJnkLrHBFadkifdXrXSWHTJRs Hg/odVBOAzDgFlJNbRWS6c8pXkX/EOBNZzjOX7yKmrCOTPsplUzVNuoO X-Gm-Gg: AR+sD10r9S2r48iu+I8sLW7NiGnrqsTNgs4DWGF6d8QcuZ3vs5KinkTOzXXtnTi4J4d rWpvPMOx1vuH/L3f+qbmhvFqV9lda9SPS+Vd+AVIhBzqDTaFsEGj8j0U0+DiA0nnuXnuS8JcXFS VvA/Pss5akrg8bQsG5WDAG6ilwFXBmLW39lYpNbu9FAFQyaLAKuE4+NNi+0ta5wXRYn1PBItlV9 UFeJ8fCbSy2h2LL3Ma7IYBwHoWhDTqR2bFV/iO3DcJZSCrKUhOFe2/RVH1a8Bs82qkEAmy3MkUw S63w08TktLeBCgtpJcFV8hk78Q7VFrnH0l9Yn22BOhkEioxOJhJHL5mr1M33H7Wx4dPF9IePW7/ 4Ikq2NvbaefexAfd2v9Tyrj3+3VP5pVjUtwRjy4orshBfAeExxACxNxEbHu58/pZRqw1vLLVIGV H9UtvV/QAPzKGfFL23ud2xGXup6lowgphfwjLLHxVGFXaxgjgeJz2F8Rhk8wOZH3rphsCEhyKW6 6wcT9ImfERhr5wj8SUmfpS5BFSm0Y0ZLC5jbwrP/DcBU8RC X-Received: by 2002:a05:6a00:14d0:b0:848:2f77:e2e4 with SMTP id d2e1a72fcca58-84e933abff7mr7112261b3a.77.1785326883391; Wed, 29 Jul 2026 05:08:03 -0700 (PDT) Received: from m-upc-A520M-HDV.lan ([2400:2410:3f60:500:c705:d3b3:a6d9:8512]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-84ea0300ac2sm1263482b3a.35.2026.07.29.05.07.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Jul 2026 05:08:01 -0700 (PDT) Sender: Yuyang Huang From: Yuyang Huang To: Yuyang Huang Cc: "David S. Miller" , Bobby Eshleman , Chris J Arges , David Ahern , David Wei , Dimitri Daskalakis , Donald Hunter , Eric Dumazet , Gal Pressman , Ido Schimmel , Jakub Kicinski , Paolo Abeni , Shuah Khan , Simon Horman , Stanislav Fomichev , Willem de Bruijn , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH net-next v4 03/10] ipv6: record the reason for kernel-initiated route deletions Date: Wed, 29 Jul 2026 21:07:32 +0900 Message-ID: <20260729120739.47880-4-sigefriedhyy@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260729120739.47880-1-sigefriedhyy@gmail.com> References: <20260729120739.47880-1-sigefriedhyy@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Record why the kernel deletes an IPv6 route on its own: - RTA_DEL_REASON_EXPIRED for routes reaped by the FIB6 garbage collector after their RTF_EXPIRES lifetime ran out. - RTA_DEL_REASON_RA_WITHDRAWN for default routes, prefix routes and RFC 4191 route information routes withdrawn by a zero-lifetime Router Advertisement. Deleting a default route because its metric changed is not a withdrawal, so it keeps RTA_DEL_REASON_UNSPEC. Signed-off-by: Yuyang Huang --- net/ipv6/addrconf.c | 3 ++- net/ipv6/ip6_fib.c | 2 +- net/ipv6/ndisc.c | 4 +++- net/ipv6/route.c | 2 +- 4 files changed, 7 insertions(+), 4 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f1fe9ede1edb..1ca9d82b5721 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2874,7 +2874,8 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) if (rt) { /* Autoconf prefix route */ if (valid_lft == 0) { - ip6_del_rt(net, rt, false); + ip6_del_rt_reason(net, rt, false, + RTA_DEL_REASON_RA_WITHDRAWN); rt = NULL; } else { table = rt->fib6_table; diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index b6e3bdd20cd0..d77c61f53155 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -2402,7 +2402,7 @@ static void fib6_gc_table(struct net *net, hlist_for_each_entry_safe(rt, n, &tb6->tb6_gc_hlist, gc_link) if (fib6_age(rt, gc_args) == -1) - fib6_del(rt, &info, RTA_DEL_REASON_UNSPEC); + fib6_del(rt, &info, RTA_DEL_REASON_EXPIRED); } static void fib6_gc_all(struct net *net, struct fib6_gc_args *gc_args) diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index f867ec8d3d90..713db9089d5e 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1361,7 +1361,9 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; /* delete the route if lifetime is 0 or if metric needs change */ if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { - ip6_del_rt(net, rt, false); + ip6_del_rt_reason(net, rt, false, + lifetime == 0 ? RTA_DEL_REASON_RA_WITHDRAWN : + RTA_DEL_REASON_UNSPEC); rt = NULL; } diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 7574c385105f..d2b9f9a899cf 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1020,7 +1020,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, gwaddr, dev); if (rt && !lifetime) { - ip6_del_rt(net, rt, false); + ip6_del_rt_reason(net, rt, false, RTA_DEL_REASON_RA_WITHDRAWN); rt = NULL; } -- 2.43.0