From patchwork Sat Feb 5 08:17:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 12736007 X-Patchwork-Delegate: kuba@kernel.org 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 C53A3C433EF for ; Sat, 5 Feb 2022 08:17:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351944AbiBEIR4 (ORCPT ); Sat, 5 Feb 2022 03:17:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351216AbiBEIRr (ORCPT ); Sat, 5 Feb 2022 03:17:47 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 471A1C061355; Sat, 5 Feb 2022 00:17:46 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id y5-20020a17090aca8500b001b8127e3d3aso8294778pjt.3; Sat, 05 Feb 2022 00:17:46 -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=q7pnMxxA41QGRIEltZrYAcSJW8Szr5sjwJMXNTY+cos=; b=Dh4/dRqdta5uoH/FAXGRbVbWSY8pJEUGbFjdzdu0nZNYBEktAfy+TEMqZMyrzXFXsL njI7zxaz1ALv/hKQyUOtaz1YTecrPOHuB/J+xIIRBa1lWvqSmGwEAPxWY6WQEnjfjuRV OljLmpO0mjQfd8GkGen6hQIyIgW88z2e+sbfsmw0pD3unDP8Z3x1Gz/Ou2t/BaY6lIJg syHhAZVbvzREA+t83+AziFzxJu0lnPJ5zrEcGTW0llioPcUiINCO3RLZn00kbjd4781h Rf3/mXF9sdXBPdbL3JnBxwuNaEbw77W+u3fDIvDUbW8LyWL0fJLtf8sXR3MPFMMhyeHJ frFA== 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=q7pnMxxA41QGRIEltZrYAcSJW8Szr5sjwJMXNTY+cos=; b=O99zq79CiNZk7emL9FGGKqmhfxTmXN2+W5KgvoJYfY9x9bmslbe2jSHW23o1nPtshH bSnxhWC5H1YBoJMm6bve5O5kkg3/rBOQDX+RZ9hva96dlUGfKuYUfyZ6ePhpYkDul3A9 FpiaAJnScbJ25/zctYXbPDFdHkoT/EvilrLH7H7VMV4sOqgXMwJec8s4WyBeXx7kOgvx pfLja+jp/wz9fbQcVj6tbmsJPogHnH3DTds7O9dPboCqvBMYLxDoNFCI+uFI/5qehWh7 EXYp+cMUkHhxbJhffpfADwKFJWxlzjshBZTE6AF48zYP2lPlX9XWpmUosBHTYtZcz3Kp G8Wg== X-Gm-Message-State: AOAM531S4gpr263KGq8LGo+5LbTnFS5XpW51tkgOs/H1i5sSs1jZG2Jc ZoGPjB1zVOV2VzgbZe3/Qe8= X-Google-Smtp-Source: ABdhPJz8EaqFeLlCCHRtBL8zk/a7lfH+n/ALNUfnxXXU6q18NCq1RfGxBtIc6Q5L3mxNWekrfZ45LQ== X-Received: by 2002:a17:902:7784:: with SMTP id o4mr6932893pll.173.1644049066363; Sat, 05 Feb 2022 00:17:46 -0800 (PST) Received: from localhost.localdomain ([43.132.141.4]) by smtp.gmail.com with ESMTPSA id b12sm4826934pfm.154.2022.02.05.00.17.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Feb 2022 00:17:45 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org, dsahern@kernel.org, idosch@idosch.org Cc: nhorman@tuxdriver.com, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, Menglong Dong Subject: [PATCH v6 net-next] net: drop_monitor: support drop reason Date: Sat, 5 Feb 2022 16:17:38 +0800 Message-Id: <20220205081738.565394-1-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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. The drop reasons are reported as string to users, which is exactly the same as what we do when reporting it to ftrace. Signed-off-by: Menglong Dong --- v6: - check the range of drop reason in net_dm_packet_report_fill() v5: - check if drop reason larger than SKB_DROP_REASON_MAX v4: - report drop reasons as string v3: - referring to cb->reason and cb->pc directly in net_dm_packet_report_fill() 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 | 29 +++++++++++++++++++++++++---- 2 files changed, 26 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/net_dropmon.h b/include/uapi/linux/net_dropmon.h index 66048cc5d7b3..1bbea8f0681e 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, /* string */ __NET_DM_ATTR_MAX, NET_DM_ATTR_MAX = __NET_DM_ATTR_MAX - 1 diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 7b288a121a41..1180f1a28599 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -48,6 +48,16 @@ static int trace_state = TRACE_OFF; static bool monitor_hw; +#undef EM +#undef EMe + +#define EM(a, b) [a] = #b, +#define EMe(a, b) [a] = #b + +static const char *drop_reasons[SKB_DROP_REASON_MAX + 1] = { + TRACE_SKB_DROP_REASON +}; + /* net_dm_mutex * * An overall lock guarding every operation coming from userspace. @@ -126,6 +136,7 @@ struct net_dm_skb_cb { struct devlink_trap_metadata *hw_metadata; void *pc; }; + enum skb_drop_reason reason; }; #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0])) @@ -498,6 +509,7 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ignore, { ktime_t tstamp = ktime_get_real(); struct per_cpu_dm_data *data; + struct net_dm_skb_cb *cb; struct sk_buff *nskb; unsigned long flags; @@ -508,7 +520,9 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ignore, if (!nskb) return; - NET_DM_SKB_CB(nskb)->pc = location; + cb = NET_DM_SKB_CB(nskb); + cb->reason = reason; + cb->pc = location; /* Override the timestamp because we care about the time when the * packet was dropped. */ @@ -606,8 +620,9 @@ 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 = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc; + struct net_dm_skb_cb *cb = NET_DM_SKB_CB(skb); char buf[NET_DM_MAX_SYMBOL_LEN]; + unsigned int reason; struct nlattr *attr; void *hdr; int rc; @@ -620,10 +635,16 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb, if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW)) goto nla_put_failure; - if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD)) + if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, (u64)(uintptr_t)cb->pc, + NET_DM_ATTR_PAD)) + goto nla_put_failure; + + reason = (unsigned int)cb->reason; + if (reason < SKB_DROP_REASON_MAX && + nla_put_string(msg, NET_DM_ATTR_REASON, drop_reasons[reason])) goto nla_put_failure; - snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc); + snprintf(buf, sizeof(buf), "%pS", cb->pc); if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf)) goto nla_put_failure;