From nobody Tue Jun 30 03:37:46 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3DCBC28CF5 for ; Wed, 26 Jan 2022 07:23:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237724AbiAZHXW (ORCPT ); Wed, 26 Jan 2022 02:23:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229641AbiAZHXV (ORCPT ); Wed, 26 Jan 2022 02:23:21 -0500 Received: from mail-pj1-x1042.google.com (mail-pj1-x1042.google.com [IPv6:2607:f8b0:4864:20::1042]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0856DC06161C; Tue, 25 Jan 2022 23:23:20 -0800 (PST) Received: by mail-pj1-x1042.google.com with SMTP id h12so22458685pjq.3; Tue, 25 Jan 2022 23:23:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8z8QaPzSpYleEBkb/3BW1hePTgzB2h/wRA/Ef7uJuSQ=; b=MAFclsnfDcCr0FlzF9arMxcarozNUtuK2GFdTbelSb7Wkrit6g+KTuDNq9rdY9yCn/ 8++JLr87o3SKB3jPC/s/Gyj7e8RAy3SMFa+ukm78x5gsUs+SS5trFyNK5LwcIcWarjzD tboNUACtPRZMaKtJ6UdX1jVmkLi/Kae5MKoa6FZ0RYmsOwTo3W8h+lMyVnYXwMyH2y4a BZII28i7KghfPYhZMy2lenrGsNGYzZhKBa4g1QkWY4fVPF38nx7mq3uXuYTrYsx+gKhK IUxfNwf+xusB9uGIxEteT61p3ZCDBbVIOfU0MZ8yNGjbw1STde1z9932YW6+i3rTSTbz JWQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8z8QaPzSpYleEBkb/3BW1hePTgzB2h/wRA/Ef7uJuSQ=; b=ig9GD6yJ8GdfrfKVGcC9aWpASHDmG0LZQdUyPbS68zXZ9mJEmAf624YFxKIvPvUNEV MYl0xKGeLwrq7arZrKe2TJf2jG/BvvDszjSqQsDkUa5YExW/2rfjPI5/tcf+dNlXUkdN y8EnhhQI0Y1RP/0snxw8kGFYkwkKIk8kFKdD4Lxf9qR8nGfvQtnHa/OXu3sSPBvkGnkE wZUUFe0Q+ompv5cgscKbm5ByDZGnAfEJOvlS+VotfbxMdIfT2HQiT/ybeBr41TpfsVz8 m3a7aT8JnWCM6g8c9wMV6C3qujQ1iWJS2TMthfQXmUFNNfhTeTa7c7szI92LIq9hEn+1 T8Zg== X-Gm-Message-State: AOAM531rEUpRBZrSxVwEJmO2JYqgJJLo2WdVJA9LtgUF26mhks8eQUKs ppE1SvS3UxgZFu6+Q6/OU11Ob7MszSk= X-Google-Smtp-Source: ABdhPJxmdCDH1bkuwdkyi7FVRgTPEkNEGS4N9qOcrJAkIwBH3ql00NGu2M455/W+Rx/9K6Kdx2El4A== X-Received: by 2002:a17:902:e552:b0:149:b7bf:9b42 with SMTP id n18-20020a170902e55200b00149b7bf9b42mr21223022plf.70.1643181800405; Tue, 25 Jan 2022 23:23:20 -0800 (PST) Received: from localhost.localdomain ([43.132.141.4]) by smtp.gmail.com with ESMTPSA id l21sm1061884pfu.120.2022.01.25.23.23.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Jan 2022 23:23:19 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org Cc: nhorman@tuxdriver.com, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dsahern@kernel.org, rostedt@goodmis.org, Menglong Dong Subject: [PATCH v2 net-next] net: drop_monitor: support drop reason Date: Wed, 26 Jan 2022 15:23:06 +0800 Message-Id: <20220126072306.3218272-1-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Menglong Dong In the commit c504e5c2f964 ("net: skb: introduce kfree_skb_reason()") drop reason is introduced to the tracepoint of kfree_skb. Therefore, drop_monitor is able to report the drop reason to users by netlink. For now, the number of drop reason is passed to users ( seems it's a little troublesome to pass the drop reason as string ). Therefore, users can do some customized description of the reason. Signed-off-by: Menglong Dong --- v2: - get a pointer to struct net_dm_skb_cb instead of local var for each field --- include/uapi/linux/net_dropmon.h | 1 + net/core/drop_monitor.c | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/net_dropmon.h b/include/uapi/linux/net_drop= mon.h index 66048cc5d7b3..b2815166dbc2 100644 --- a/include/uapi/linux/net_dropmon.h +++ b/include/uapi/linux/net_dropmon.h @@ -93,6 +93,7 @@ enum net_dm_attr { NET_DM_ATTR_SW_DROPS, /* flag */ NET_DM_ATTR_HW_DROPS, /* flag */ NET_DM_ATTR_FLOW_ACTION_COOKIE, /* binary */ + NET_DM_ATTR_REASON, /* u32 */ =20 __NET_DM_ATTR_MAX, NET_DM_ATTR_MAX =3D __NET_DM_ATTR_MAX - 1 diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 7b288a121a41..b5d8e19ccc1d 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -126,6 +126,7 @@ struct net_dm_skb_cb { struct devlink_trap_metadata *hw_metadata; void *pc; }; + enum skb_drop_reason reason; }; =20 #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0])) @@ -498,6 +499,7 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ign= ore, { ktime_t tstamp =3D ktime_get_real(); struct per_cpu_dm_data *data; + struct net_dm_skb_cb *cb; struct sk_buff *nskb; unsigned long flags; =20 @@ -508,7 +510,9 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ign= ore, if (!nskb) return; =20 - NET_DM_SKB_CB(nskb)->pc =3D location; + cb =3D NET_DM_SKB_CB(nskb); + cb->reason =3D reason; + cb->pc =3D location; /* Override the timestamp because we care about the time when the * packet was dropped. */ @@ -606,12 +610,17 @@ static int net_dm_packet_report_in_port_put(struct sk= _buff *msg, int ifindex, static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *= skb, size_t payload_len) { - u64 pc =3D (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc; + struct net_dm_skb_cb *cb =3D NET_DM_SKB_CB(skb); char buf[NET_DM_MAX_SYMBOL_LEN]; + enum skb_drop_reason reason; struct nlattr *attr; void *hdr; + u64 pc; int rc; =20 + pc =3D (u64)(uintptr_t)cb->pc; + reason =3D cb->reason; + hdr =3D genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0, NET_DM_CMD_PACKET_ALERT); if (!hdr) @@ -623,6 +632,9 @@ static int net_dm_packet_report_fill(struct sk_buff *ms= g, struct sk_buff *skb, if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD)) goto nla_put_failure; =20 + if (nla_put_u32(msg, NET_DM_ATTR_REASON, reason)) + goto nla_put_failure; + snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc); if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf)) goto nla_put_failure; --=20 2.34.1