From patchwork Thu Sep 5 07:17:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Xing X-Patchwork-Id: 13791827 Received: from mail-pg1-f177.google.com (mail-pg1-f177.google.com [209.85.215.177]) (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 1A2B219306B; Thu, 5 Sep 2024 07:17:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.177 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725520678; cv=none; b=Ip7DJeJL50VAO6zwIRULZKVqUvoeg5/NNly+rRWXUuQ06qNmpHvbqbNGYXctCEUBPn0vvIddL03OTpxhQIIkHtVPmFGfR8BAUt+DxWbVjig+7XXpzde423W0y1K5sFDdjPgeeiArBbulPjuYJGmaQmNmOC7XgQUKt8NNzFT/aZI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725520678; c=relaxed/simple; bh=pm18LzKuf7Pe/TqQlkff7gRCifSAML3mIMou2tvYhtg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=nfHDd8YtLdRU4Pq8oij1r8PRo02ytyCK9/JzadzAJ/SknDKpcQMYMJm1DH3a6BCCuebKnw6P61O06XInBV2SR9JH77zC2J3OD/YPQSEHQWAdXXbF3HfuD2t3iqnKBGXmMu8zGet2kmESVUqF1RRnoNcumG8b4JSNYRddQsSv7Y0= 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=HbHlXroJ; arc=none smtp.client-ip=209.85.215.177 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="HbHlXroJ" Received: by mail-pg1-f177.google.com with SMTP id 41be03b00d2f7-7d4f6d8c1eeso360101a12.1; Thu, 05 Sep 2024 00:17:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725520676; x=1726125476; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=r2o2hbaaXm5/I0Rt4fzNJUxwimu3WCgjAFqRCFnWp90=; b=HbHlXroJ5YesjTJuXzLS+8kO5FARwVM4PNkyl1EUn1gJsMev2bAhqSyeYudzc2Sq6I LrIp+qJTj7vbtiCDdXy43iJuZvOKAsMYuS0ekzJJSVYxbU+iq1gaE0DyPlSQEfEe2o4v +bRhQpSOFau9NtPRwAPF5h0k/I1D7bepx89CSGbQ3XhL/7S+ViEsL/3FxlCxo/SPsW+Z Ni0aW6cAfInsIeXH4U7VYAO+XqmZbDHsihhdX6jlg2EK0eaRbyN6bRldWvVsQlH0jrjJ XsX1PAHDW1KL4ht8zwyPiJHRztA2Cv+/THpRF49K3Az6ala1f1xT7Cj9eGXrW1+8JgNZ 8eqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725520676; x=1726125476; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=r2o2hbaaXm5/I0Rt4fzNJUxwimu3WCgjAFqRCFnWp90=; b=Z0/OBnuZgOmbwpSspEcTzAQYs72VOthDpVRKSeZZeAv8j1Jy4JB2VYU1yzF6p/VWpE /T4JONyIARoUfkqkMiFfc5oeoYVN1kdyYZmx3q1c4Wji9416ljP3YiZqAc/SdBSlF0wF I1LE8YUuuJ8RUGQQZ41qMsIDEm/fJukMni4WuLXaNMpnEAZX5bvsXtcZGFnt3w2PNkbq GBd0Mt6W7lbvrrR5SBc1HMToVUDkW9B0R6oQp4sg9TgHljXWv/w0qTQxUFoyTV667sPc QJNpMqO+2lfrXEZywAigGND7tCMdaNCG2HNeYtjFskwsKkaILJztqr+AGEgDsxgDzrxp 1IGQ== X-Forwarded-Encrypted: i=1; AJvYcCUnO8/D3nv4jeeyBBVIdajmWqcDBBm+0EcnDML0N/yH27ryNuaswFr2p4596OnDawazNeHvMoc=@vger.kernel.org X-Gm-Message-State: AOJu0YzBpTlq6Gr460NVhY8GTVjx74bzucpBon93Jps6Gptn57BoAUJm 8lPfvFZ/cXnJvK0RD08SJriMoxB8KQSty3glsY7/YtApIgNHZj8C X-Google-Smtp-Source: AGHT+IF3P19sPUd0ouuwNRSN9DiPnMWG75Vzki1Vpej8NwUZMf3dRz+Aacb9hECi2eUzY0s1F+RbsA== X-Received: by 2002:a17:902:e804:b0:1fc:568d:5f05 with SMTP id d9443c01a7336-205472c61acmr190174145ad.8.1725520676022; Thu, 05 Sep 2024 00:17:56 -0700 (PDT) Received: from KERNELXING-MB0.tencent.com ([43.132.141.24]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-206ae913b19sm22929425ad.61.2024.09.05.00.17.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Sep 2024 00:17:55 -0700 (PDT) From: Jason Xing To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, willemdebruijn.kernel@gmail.com, shuah@kernel.org, willemb@google.com Cc: linux-kselftest@vger.kernel.org, netdev@vger.kernel.org, Jason Xing Subject: [PATCH net-next v4 1/4] net-timestamp: filter out report when setting SOF_TIMESTAMPING_SOFTWARE Date: Thu, 5 Sep 2024 15:17:34 +0800 Message-Id: <20240905071738.3725-2-kerneljasonxing@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20240905071738.3725-1-kerneljasonxing@gmail.com> References: <20240905071738.3725-1-kerneljasonxing@gmail.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jason Xing introduce a new flag SOF_TIMESTAMPING_OPT_RX_FILTER in the receive path. User can set it with SOF_TIMESTAMPING_SOFTWARE to filter out rx software timestamp report, especially after a process turns on netstamp_needed_key which can time stamp every incoming skb. Previously, we found out if an application starts first which turns on netstamp_needed_key, then another one only passing SOF_TIMESTAMPING_SOFTWARE could also get rx timestamp. Now we handle this case by introducing this new flag without breaking users. Quoting Willem to explain why we need the flag: "why a process would want to request software timestamp reporting, but not receive software timestamp generation. The only use I see is when the application does request SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_TX_SOFTWARE." In this way, we have two kinds of combination: 1. setting SOF_TIMESTAMPING_SOFTWARE|SOF_TIMESTAMPING_RX_SOFTWARE, it will surely allow users to get the rx software timestamp report. 2. setting SOF_TIMESTAMPING_SOFTWARE|SOF_TIMESTAMPING_OPT_RX_FILTER while the skb is timestamped, it will stop reporting the rx software timestamp. Another thing about errqueue in this patch I have a few words to say: In this case, we need to handle the egress path carefully, or else reporting the tx timestamp will fail. Egress path and ingress path will finally call sock_recv_timestamp(). We have to distinguish them. Errqueue is a good indicator to reflect the flow direction. Suggested-by: Willem de Bruijn Reviewed-by: Willem de Bruijn Signed-off-by: Jason Xing --- v4 Link: https://lore.kernel.org/all/20240830153751.86895-2-kerneljasonxing@gmail.com/ 1. revise the commit message and doc (Willem) 2. simplify the test statement (Jakub) 3. add Willem's reviewed-by tag (Willem) v3 1. Willem suggested this alternative way to solve the issue, so I added his Suggested-by tag here. Thanks! --- Documentation/networking/timestamping.rst | 12 ++++++++++++ include/uapi/linux/net_tstamp.h | 3 ++- net/core/sock.c | 4 ++++ net/ethtool/common.c | 1 + net/ipv4/tcp.c | 6 ++++-- net/socket.c | 4 +++- 6 files changed, 26 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst index 5e93cd71f99f..37ead02be3b1 100644 --- a/Documentation/networking/timestamping.rst +++ b/Documentation/networking/timestamping.rst @@ -266,6 +266,18 @@ SOF_TIMESTAMPING_OPT_TX_SWHW: two separate messages will be looped to the socket's error queue, each containing just one timestamp. +SOF_TIMESTAMPING_OPT_RX_FILTER: + Used in the receive software timestamp. Enabling the flag along with + SOF_TIMESTAMPING_SOFTWARE will not report the rx timestamp to the + userspace so that it can filter out the case where one process starts + first which turns on netstamp_needed_key through setting generation + flags like SOF_TIMESTAMPING_RX_SOFTWARE, then another one only passing + SOF_TIMESTAMPING_SOFTWARE report flag could also get the rx timestamp. + + SOF_TIMESTAMPING_OPT_RX_FILTER prevents the application from being + influenced by others and let the application choose whether to report + the timestamp in the receive path or not. + New applications are encouraged to pass SOF_TIMESTAMPING_OPT_ID to disambiguate timestamps and SOF_TIMESTAMPING_OPT_TSONLY to operate regardless of the setting of sysctl net.core.tstamp_allow_data. diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h index a2c66b3d7f0f..858339d1c1c4 100644 --- a/include/uapi/linux/net_tstamp.h +++ b/include/uapi/linux/net_tstamp.h @@ -32,8 +32,9 @@ enum { SOF_TIMESTAMPING_OPT_TX_SWHW = (1<<14), SOF_TIMESTAMPING_BIND_PHC = (1 << 15), SOF_TIMESTAMPING_OPT_ID_TCP = (1 << 16), + SOF_TIMESTAMPING_OPT_RX_FILTER = (1 << 17), - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_ID_TCP, + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_RX_FILTER, SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | SOF_TIMESTAMPING_LAST }; diff --git a/net/core/sock.c b/net/core/sock.c index 468b1239606c..6a93344e21cf 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -908,6 +908,10 @@ int sock_set_timestamping(struct sock *sk, int optname, !(val & SOF_TIMESTAMPING_OPT_ID)) return -EINVAL; + if (val & SOF_TIMESTAMPING_RX_SOFTWARE && + val & SOF_TIMESTAMPING_OPT_RX_FILTER) + return -EINVAL; + if (val & SOF_TIMESTAMPING_OPT_ID && !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) { if (sk_is_tcp(sk)) { diff --git a/net/ethtool/common.c b/net/ethtool/common.c index 781834ef57c3..6c245e59bbc1 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -427,6 +427,7 @@ const char sof_timestamping_names[][ETH_GSTRING_LEN] = { [const_ilog2(SOF_TIMESTAMPING_OPT_TX_SWHW)] = "option-tx-swhw", [const_ilog2(SOF_TIMESTAMPING_BIND_PHC)] = "bind-phc", [const_ilog2(SOF_TIMESTAMPING_OPT_ID_TCP)] = "option-id-tcp", + [const_ilog2(SOF_TIMESTAMPING_OPT_RX_FILTER)] = "option-rx-filter", }; static_assert(ARRAY_SIZE(sof_timestamping_names) == __SOF_TIMESTAMPING_CNT); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 8a5680b4e786..a0c57c8b77bd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2235,6 +2235,7 @@ void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, struct scm_timestamping_internal *tss) { int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW); + u32 tsflags = READ_ONCE(sk->sk_tsflags); bool has_timestamping = false; if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) { @@ -2274,14 +2275,15 @@ void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, } } - if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_SOFTWARE) + if (tsflags & SOF_TIMESTAMPING_SOFTWARE && + !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER)) has_timestamping = true; else tss->ts[0] = (struct timespec64) {0}; } if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) { - if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_RAW_HARDWARE) + if (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) has_timestamping = true; else tss->ts[2] = (struct timespec64) {0}; diff --git a/net/socket.c b/net/socket.c index fcbdd5bc47ac..f8609d649ed3 100644 --- a/net/socket.c +++ b/net/socket.c @@ -946,7 +946,9 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, memset(&tss, 0, sizeof(tss)); tsflags = READ_ONCE(sk->sk_tsflags); - if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) && + if ((tsflags & SOF_TIMESTAMPING_SOFTWARE && + (skb_is_err_queue(skb) || + !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) && ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0)) empty = 0; if (shhwtstamps &&